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Jacob Pleasants, Kristina M. Tank,
International Journal of STEM Education, Volume 8, pp 1-17; doi:10.1186/s40594-021-00274-3

Background Around the world, efforts are underway to include engineering design as part of elementary science instruction. A common rationale for those efforts is that Engineering Design-based Science Teaching (EDST) is a productive pedagogical approach for developing students’ understanding of core science concepts. Effectively utilizing EDST requires that teachers develop design activities that are highly connected to science content so that students can apply and expand their understanding of relevant concepts. In this study, we examine how a group of elementary (grades 3–5) pre-service and in-service teachers incorporated EDST into their planned science instruction. Those teachers were participants in a professional development project aimed at supporting EDST. We examine the ways that participants used EDST, the extent to which engineering design activities were connected to science concepts, and factors associated with those connections. Results Most of the participants in the study developed science units in which an engineering design activity was placed at the end of the unit. Approximately half of those design activities lacked connections to the science concepts in the unit; they were typically related to the topic of the science unit, but did not require the use or development of key science ideas. Eleven percent of participants developed engineering activities with deep connections to science concepts, and 35% developed activities with shallow connections. No differences were found between life science, physical science, and earth/space science units in terms of the extent of conceptual connections. However, we did find that participants who utilized and adapted published engineering curriculum materials rather than make them from scratch were more likely to have unit plans with higher levels of conceptual connections. Conclusions Our findings suggest that elementary teachers need additional support in order to effectively utilize EDST in their classrooms. Even within the context of a supportive professional development project, most of the engineering activities developed by our participants lacked substantial connections to the science concepts in their unit plans. Our findings highlight the value of high-quality curriculum materials to support EDST as well as the need to further expand the curriculum resources that are available to elementary teachers.
, Fatema Tuz Johora, Bishajit Sarkar, Yusha Araf, Nafisa Ahmed, Abida Nurun Nahar, Tanzina Akter
Egyptian Journal of Medical Human Genetics, Volume 22, pp 1-15; doi:10.1186/s43042-021-00150-3

Background Alzheimer’s disease (AD) is a progressive neurodegenerative age-related dementia that results in memory loss of elderly people. Many hypotheses have been formally articulated till now to decipher the pathogenesis of this disease. According to the compelling amyloidogenic hypothesis, β-secretase is a key regulatory enzyme in AD development and is therefore considered as one of the major targets for the development of drugs to treat AD. In this study, 40 plant-derived phytocompounds, proven to have β-secretase inhibitory activity in different laboratory experiments, were evaluated using computational approaches in order to identify the best possible β-secretase inhibitor(s). Results Amentoflavone (IFD score: − 7.842 Kcal/mol), Bilobetin (IFD score: − 7.417 Kcal/mol), and Ellagic acid (IFD score: − 6.923 Kcal/mol) showed highest β-secretase inhibitory activities with high binding affinity among all the selected phytocompounds and interacted with key amino acids, i.e., Asp32, Tyr71, and Asp228 in the catalytic site of β-secretase. Moreover, these three molecules exhibited promising results in different drug potential assessment experiments and displayed signs of correlation with significant pharmacological and biological activities. Conclusion Amentoflavone, Biolbetin, and Ellagic acid could be investigated further in developing β-secretase-dependent drug for the effective treatment of AD. However, additional in vivo and in vitro experiments might be required to strengthen the findings of this experiment.
, Huanyu Guo, Jiaqi Huang, Shaoming Jiang, Shibo Hou, Xingyu Chen, Hujie Lv, Xudong Bi, Maolin Hou, Hebei Lin, et al.
Bioresources and Bioprocessing, Volume 8, pp 1-17; doi:10.1186/s40643-021-00380-8

Under the optimal conditions of immobilization and fermentation, the highest LA yield of 0.966 ± 0.006 g/g fructose and production rate of 2.426 ± 0.018 g/(L × h) with an error of -0.5% and -0.2% to the predicted results were obtained from batch fermentation by the CS film-coated SA-PVA immobilized L. pentosus cells. The LA yield and production rate of these immobilized cells were 2.7% and 10.1% higher than that of normal SA-PVA immobilized cells respectively, and they were 5.7% and 48.4% higher than that of free cells, respectively. The effect of temperature on different types of immobilized cells and free cells was significantly different, but the effect of pH on different types of cells was not much different. The kinetic models could effectively describe the different fermentation performances of three types of cells. The immobilized cells have excellent reusability to conduct 9 runs of repeated batch fermentation.
Ahmad Y. A. Salamooni,
Advances in Difference Equations, Volume 2021, pp 1-20; doi:10.1186/s13662-021-03358-0

In this paper, we use some fixed point theorems in Banach space for studying the existence and uniqueness results for Hilfer–Hadamard-type fractional differential equations $$ {}_{\mathrm{H}}D^{\alpha ,\beta }x(t)+f\bigl(t,x(t)\bigr)=0 $$ D α , β H x ( t ) + f ( t , x ( t ) ) = 0 on the interval $(1,e]$ ( 1 , e ] with nonlinear boundary conditions $$ x(1+\epsilon )=\sum_{i=1}^{n-2}\nu _{i}x(\zeta _{i}),\qquad {}_{\mathrm{H}}D^{1,1}x(e)= \sum_{i=1}^{n-2} \sigma _{i}\, {}_{\mathrm{H}}D^{1,1}x( \zeta _{i}). $$ x ( 1 + ϵ ) = ∑ i = 1 n − 2 ν i x ( ζ i ) , H D 1 , 1 x ( e ) = ∑ i = 1 n − 2 σ i H D 1 , 1 x ( ζ i ) .
Nurlelasari, Intan Rahmayanti, , Agus Safari, Desi Harneti, Rani Maharani, Ace Tatang Hidayat, Mulyadi Tanjung, Rurini Retnowati, Yoshihito Shiono, et al.
Applied Biological Chemistry, Volume 64, pp 1-6; doi:10.1186/s13765-021-00606-5

A new havanensin-type limonoid, 16β-hydroxydysobinin (1), along with four known limonoids (2–5), have been isolated from the seeds of Chisocheton macrophyllus. The chemical structure of the new compound was determined by referencing spectroscopic data, and by comparison to those related spectra previously reported. Each compound was evaluated for their cytotoxic effects against Michigan Cancer Foundation-7 (MCF-7) breast cancer cells and display no significant activity.
, Karin Täht, Kristjan Vassil
International Journal of STEM Education, Volume 8, pp 1-14; doi:10.1186/s40594-021-00287-y

Background The excessive use of Internet-based technologies has received a considerable attention over the past years. Despite this, there is relatively little research on how general Internet usage patterns at and outside of school as well as on weekends may be associated with mathematics achievement. Moreover, only a handful of studies have implemented a longitudinal or repeated-measures approach on this research question. The aim of the current study was to fill that gap. Specifically, we investigated the potential associations of Internet use at and outside of school as well as on weekends with mathematics test performance in both high- and low-stakes testing conditions over a period of 3 years in a representative sample of Estonian teenagers. Methods PISA 2015 survey data in conjunction with national educational registry data were used for the current study. Specifically, Internet use at and outside of school as well as on weekends were queried during the PISA 2015 survey. In addition, the data set included PISA mathematics test results from 4113 Estonian 9th-grade students. Furthermore, 3758 of these students also had a 9th-grade national mathematics exam score from a couple of months after the PISA survey. Finally, of these students, the results of 12th-grade mathematics national exam scores were available for 1612 and 1174 students for “wide” (comprehensive) and “narrow” (less comprehensive) mathematics exams, respectively. Results The results showed that the rather low-stakes PISA mathematics test scores correlated well with the high-stakes national mathematics exam scores obtained from the 9th (completed a couple of months after the PISA survey) and 12th grade (completed approximately 3 years after the PISA survey), with correlation values ranging from r = .438 to .557. Furthermore, socioeconomic status index was positively correlated with all mathematics scores (ranging from r = .162 to .305). Controlled for age and gender, the results also showed that students who reported using Internet the longest tended to have, on average, the lowest mathematics scores in all tests across 3 years. Although effect sizes were generally small, they seemed to be more pronounced in Internet use at school. Conclusions Based on these results, one may notice that significantly longer time spent on Internet use at and outside of school as well as on weekends may be associated with poorer mathematics performance. These results are somewhat in line with research outlining the potentially negative associations between longer time spent on digital technology use and daily life outcomes.
Musa Saheed Ibrahim, Beckley Ikhajiagbe
Bulletin of the National Research Centre, Volume 45, pp 1-20; doi:10.1186/s42269-021-00528-8

Background Rice forms a significant portion of food consumed in most household worldwide. Rice production has been hampered by soil factors such as ferruginousity which has limited phosphorus availability; an important mineral component for the growth and yield of rice. The presence of phosphate-solubilizing bacteria (PSB) in soils has been reported to enhance phosphate availability. In view of this, the present study employed three bacteria species (BCAC2, EMBF2 and BCAF1) that were previously isolated and proved P solubilization capacities as inocula to investigate the growth response of rice germinants in an in vitro setup. The bacteria isolates were first identified using 16S rRNA gene sequencing and then applied as inoculum. The inolula were prepared in three concentrations (10, 7.5 and 5.0 ml) following McFarland standard. Viable rice (var. FARO 44) seeds were sown in petri dishes and then inoculated with the three inocula at the different concentrations. The setup was studied for 28 days. Results 16S rRNA gene sequencing identified the isolates as: isolate BCAC2= Bacillus cereus strain GGBSU-1, isolate BCAF1= Proteus mirabilis strain TL14-1 and isolate EMBF2= Klebsiella variicola strain AUH-KAM-9. Significant improvement in rice germination, morphology, physiology and biomass parameters in the bacteria-inoculated setups was observed compared to the control. Germination percentage after 4 days was 100 % in the inoculated rice germinants compared to 65% in the control (NiS). Similarly, inoculation with the test isolates enhanced water-use efficiency by over 40%. The rice seedlings inoculated with Bacillus cereus strain GGBSU-1 (BiS) showed no signs of chlorosis and necrosis throughout the study period as against those inoculated with Proteus mirabilis strain TL14-1 (PiS) and Klebsiella variicola strain AUH-KAM-9 (KiS). Significant increase in chlorophyll-a, chlorophyll-b and alpha amylase was observed in the rice seedlings inoculated with BiS as against the NiS. Conclusion Inoculating rice seeds with Bacillus cereus strain GGBSU-1, Proteus mirabilis strain TL14-1 and Klebsiella variicola strain AUH-KAM-9 in an in vitro media significantly improved growth parameters of the test plant. Bacillus cereus strain GGBSU-1 showed higher efficiency due to a more improved growth properties observed.
Tikui Zhang, Sensen Li, Bin Yu
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-21; doi:10.1186/s13638-021-01954-y

Multi-kernel polar codes have recently received considerable attention since they can provide more flexible code lengths than do the original ones. The construction process of them can be simplified by obtaining the Bhattacharyya parameter bounds of the kernels employed. However, there has been currently no generic method for seeking such bounds. In this paper, therefore, we focus on the upper Bhattacharyya parameter bounds of the standard binary polar code kernels with an arbitrary dimension of $$l\ge 2$$ l ≥ 2 . A calculation process composing of four steps, the common column binary tree construction for the channel inputs, the common factor extraction, the calculation feasibility testing, and the upper bound calculation based on pattern matching, is formulated with a computational complexity of $$O(2^l)$$ O ( 2 l ) . It is theoretically proved that the upper bounds obtained by the proposed method are tight, which can lay the foundation to compare the reliability of the synthesized channels in polar codes.
Dumitru Baleanu, Ali Saleh Alshomrani, Malik Zaka Ullah
Advances in Difference Equations, Volume 2021, pp 1-16; doi:10.1186/s13662-021-03352-6

In this study, we investigate a new fourth-order integrable nonlinear equation. Firstly, by means of the efficient Hirota bilinear approach, we establish novel types of solutions which include breather, rogue, and three-wave solutions. Secondly, with the aid of Lie symmetry method, we report the invariance properties of the studied equation such as the group of transformations, commutator and adjoint representation tables. A differential substitution is found by nonlinear self-adjointness (NSA) and thereafter the associated conservation laws are established. We show some dynamical characteristics of the obtained solutions through via the 3-dimensional and contour graphs.
Chong Guo, Bei Gong
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-17; doi:10.1186/s13638-021-01967-7

In order to solve the problem between low power of Internet of Things devices and the high cost of cryptography, lightweight cryptography is required. The improvement of the scalar multiplication can effectively reduce the complexity of elliptic curve cryptography (ECC). In this paper, we propose a fast formula for point septupling on elliptic curves over binary fields using division polynomial and multiplexing of intermediate values to accelerate the computation by more than 14%. We also propose a scalar multiplication algorithm based on the step multi-base representation using point halving and the septuple formula we proposed, which significantly reduces the computational cost. The experimental results show that our method is more efficient over binary fields and contributes to reducing the complexity of ECC.
Mingzhu Huang
Advances in Difference Equations, Volume 2021, pp 1-10; doi:10.1186/s13662-021-03354-4

In this paper, we discuss the existence and approximation of solutions for a fourth-order nonlinear boundary value problem by using a quasilinearization technique. In the presence of a lower solution α and an upper solution β in the reverse order $\alpha \geq \beta $ α ≥ β , we show the existence of (extreme) solution.
Elina Turjanmaa, Inga Jasinskaja-Lahti
Comparative Migration Studies, Volume 9, pp 1-1; doi:10.1186/s40878-021-00236-2

An amendment to this paper has been published and can be accessed via the original article.
Farzana Cassim, Amy Pearlman, Ethan Matz, Ryan Terlecki, Andre van der Merwe, John Lazarus, Cecelia Lloyd, Bhavish Kowlessur
African Journal of Urology, Volume 27, pp 1-5; doi:10.1186/s12301-021-00154-w

Background Testicular germ cell tumor (TGCT) is most frequently diagnosed in young males and its etiology remains poorly understood. Cases of newly diagnosed TGCT have been rising in the United States and incidence among African Americans (AA) has increased nearly 40%. Incidence of TGCT in native black African (BA) males, conversely, has remained low. We sought to determine the racial identification of patients diagnosed with TGCT in Cape Town, South Africa. We hypothesize that the rise in TGCT among AA males is distinct from that of BA males in South Africa. Methods A retrospective review involving two tertiary care centres in the Western Cape was performed. Data were extracted for males > 13 years of age diagnosed with TGCT from January 1, 2000 to June 30, 2015. Racial status was self-declared and included BA, Caucasian, Mixed Ancestry (MA), and Asian. Patients were identified from combined Urology–Oncology clinic logs at both institutions, as well as from pathology records at the National Health Laboratory Service indicating any form of testicular cancer. Results 225 patients were identified. 97% of cases involved males identified as MA (130) or Caucasian (88). Only 2% of the study population identified as BA, with complete absence of self-identifying BA males for several years within the queried interval. Among males diagnosed with TGCT, the percentage self-identifying as Caucasian increased over time (R 2 0.92). Conclusions Males diagnosed with TGCT in the Western Cape predominantly self-identify as MA or Caucasian. Exceedingly few cases are attributed to BA, and even less to Asian males. The trend in racial distribution suggests that the increasing incidence reported for AAs may be due to interracial gene exchange, environmental factors, or a combination thereof.
Hope Kibansha Matumaini, , Kennedy Otwombe, Emily Lebotsa, Sam Luboga
African Journal of Urology, Volume 27, pp 1-5; doi:10.1186/s12301-021-00156-8

Background Voluntary medical male circumcision (VMMC) reduces the risk of HIV transmission. Task shifting of VMMCs to non-doctor health workers is recommended to enhance scale-up of VMMC programs. This study evaluated outcomes of circumcision conducted by doctors compared to non-doctors in central Uganda. Methods In this prospective observational study, we observed and followed 274 males at 3 health facilities in Kampala, Uganda. Each participant was observed during the circumcision procedure, monitored for 2 h post-surgery and assessed at 24 h, 3 days and after one week for adverse events. Results The median age of the circumcised men was 24.00(IQR, 20.00–28.00) years. Of the VMMCs, 19.3% (53/274) were carried out by doctors while 80.7% (221/274) by non-doctors. Following VMMC, 5.47% (15/274) men experienced adverse events and proportions of adverse events by cadre were similar; doctors (5.66% [3/53]) and non-doctor health workers (5.43% [12/221]), p = 0.99. Seven participants had pus discharge (all had been operated by non-doctors), 2 participants had bleeding at 2 h (one by doctor and one by non-doctor), and 4 participants had excessive skin removal (2 by doctors vs 2 by non-doctors). There was no reported urethral injury or glans amputation. Conclusion Our study found no statistically significant difference in the incidence of adverse events among VMMCs conducted by doctors compared to non-doctor health workers. Our study showed no incidence of serious adverse events such as death, urethral injury or glans amputation following VMMCs. Our results add to the existing literature to guide task shifting in the context of VMMCs.
, Vlatko Lipovac, Ivan Grbavac, Ines Obradović
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-18; doi:10.1186/s13638-021-01970-y

As the PHY/MAC-layer IR-HARQ and RLC-layer ARQ error recovery procedures, adopted in LTE, may impose additional delay when their code-block retransmissions occur, the arising question is whether these significantly contribute to IP and consequently RTP packet delays, and finally degrade the overall application-layer end-to-end QoE, especially when voice is transmitted over LTE? With this regard, we propose and demonstrate a VoLTE QoS and QoE test procedure based on PHY/MAC/RLC/IP/TCP-UDP/RTP cross-layer protocol analysis and perceptual speech quality QoE measurements. We identified monotonic relationship between the paired observations: QoE and HARQ RTT, i.e. between the PESQ voice quality rating and the IP/RTP packet latency, for given BLER of the received MAC/RLC code-blocks. Specifically, we found out that, for the HARQ RTT value of about 8 ms, only up to 2 HARQ retransmissions (and consequently no RLC-ARQ one) is appropriate during any voice packet, otherwise delay accumulation might not be accordingly “smoothed out” by jitter/playback buffers along the propagation path.
Sumin Kim, JongRak Lee
Journal of Inequalities and Applications, Volume 2021, pp 1-13; doi:10.1186/s13660-021-02602-1

In this paper, we present some necessary and sufficient conditions for the hyponormality of Toeplitz operator $T_{\varphi }$ T φ on the Bergman space $A^{2}(\mathbb{D})$ A 2 ( D ) with non-harmonic symbols under certain assumptions.
Shirong Sun,
Journal of Wood Science, Volume 67, pp 1-8; doi:10.1186/s10086-021-01964-w

Monomeric C6-C2-type lignin model compounds with a p-hydroxyphenyl (H), guaiacyl (G), syringyl (S), or p-ethylphenyl (E) nucleus (1-phenylethanol derivatives) were individually oxidized by MnO2 at a pH of 1.5 and room temperature. The results were compared with those of the corresponding C6-C1-type benzyl alcohol derivatives obtained in our recent report to examine the effect of the presence of the β-methyl group on the oxidation. The presence decelerated the oxidation regardless of the type of aromatic nucleus, although it did not change the order of the oxidation rates: G > S >> H > E. This deceleration results from the steric factor of the β-methyl group in the C6-C2-type compounds. The MnO2 oxidations of the corresponding C6-C2-type compounds deuterated at their α-(benzyl)positions showed that the magnitudes of the kinetic isotope effects are smaller than those observed in the oxidations of the corresponding C6-C1-type compounds, regardless of the type of aromatic nucleus. These smaller magnitudes suggest that the presence of the β-methyl group shifts the initial oxidation mode of MnO2 from direct oxidation of the benzyl position to one-electron oxidation of the aromatic nucleus. Only the S-type compounds afforded products via degradation of the aromatic nuclei.
Ozgur Caglar, Remzi Arslan, Binali Firinci, Muhammed Enes Aydin, Erdem Karadeniz, Kemal Alp Nalci, Ahmet Bedii Salman, Mehmet Dumlu Aydin
Annals of Pediatric Surgery, Volume 17, pp 1-9; doi:10.1186/s43159-021-00077-9

Background Circumcision is a surgical removal process of the preputium. Surgical excision and electric current cause neurodegeneration in the excised tissue-related neural network. This study investigates if circumcision and current surgical methods would cause histopathological changes in the penile tissue innervating pudendal nerve dorsal root ganglia. Results Vascular congestion occluded the microvessels, and degenerative changes were detected in postexcised penile tissue. Neuronal angulation, cytoplasmic condensation, nuclear shrinkage, and condensed nuclei were observed in the pudendal nerve ganglia. Moreover, the degenerated neuron (DN) densities of the pudendal nerve ganglia were 5 ± 2, 98 ± 22, 1093 ± 185, 236 ± 43 and 151 ± 19 in the control, the surgical circumcision, the monopolar cautery, the bipolar cautery and the thermocautery groups, respectively. Conclusions Although only the pudendal nerve endings are affected secondary to prepusium excision another pudendal axons can be damaged during bleeding control with cautery, the destruction of the neuron that sends this axon initiates a general inflammation in that ganglion. As a result, there may be a somatosensitive innervation defect in extrapenile tissues innervated by this ganglion. High-voltage electric devices should not be used unless obligatory.
Ursula Nguyen, Catherine Riegle-Crumb
International Journal of STEM Education, Volume 8, pp 1-18; doi:10.1186/s40594-021-00288-x

Background Despite the diverse student population in the USA, the labor force in Science, Technology, Engineering, and Mathematics (STEM) does not reflect this reality. While restrictive messages about who belongs in STEM likely discourage students, particularly female and minoritized students, from entering these fields, extant research on this topic is typically focused on the negative impact of stereotypes regarding math ability, or the existence of stereotypes about the physical appearance of scientists. Instead, this study builds on the limited body of research that captures a more comprehensive picture of students’ views of scientists, including not only the type of work that they do but also the things that interest them. Specifically, utilizing a sample of approximately 1000 Black and Latinx adolescents, the study employs an intersectional lens to examine whether the prevalence of counter-stereotypical views of scientists, and the association such views have on subsequent intentions to pursue STEM college majors, varies among students from different gender and racial/ethnic groups (e.g., Black female students, Latinx male students). Results While about half of Black and Latinx students reported holding counter-stereotypical beliefs about scientists, this is significantly more common among female students of color, and among Black female students in particular. Results from logistic regression models indicate that, net of control variables, holding counter-stereotypical beliefs about scientists predicts both young men’s and women’s intentions to major in computer science and engineering, but not intentions to major in either physical science or mathematics. Additionally, among Black and Latinx male students, counter-stereotypical perceptions of scientists are related to a higher likelihood of intending to major in biological sciences. Conclusions The results support the use of an intersectional approach to consider how counter-stereotypical beliefs about scientists differ across gender and racial/ethnic groups. Importantly, the results also suggest that among Black and Latinx youth, for both female and male students, holding counter-stereotypical beliefs promotes intentions to enter particular STEM fields in which they are severely underrepresented. Implications of these findings and directions for future research, specifically focusing on minoritized students, which are often left out in this body of literature, are discussed.
Chao Wang, Xiaoman Cheng, Jitong Li, Yunhua He, Ke Xiao
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-16; doi:10.1186/s13638-021-01958-8

Blockchain technology has completely changed the area of cryptocurrency with a Peer-to-Peer system named Bitcoin. It can provide a distributed, transparent and highly confidential database by recording immutable transactions. Currently, the technique has obtained great research interest on other areas, including the Internet of vehicles (IoVs). In order to solve some centralized problems and improve the architecture of the IoVs, the blockchain technology is utilized to build a decentralized and secure vehicular environment. In this survey, we aim to construct a comprehensive analysis on the applications of blockchain in the IoV. This paper starts with the introduction of the IoVs and the blockchain. Additionally, some existing surveys on the blockchain enabled IoVs are reviewed. Besides, the combination of the blockchain technology and the IoVs is analyzed from seven aspects to describe how the blockchain is implemented in the IoVs. Finally, the future research directions related to the integration are highlighted.
Elijah Abakpa Adegbe, Oluwaseyi Oluwabukola Babajide, Lois Riyo Maina, Shola Elijah Adeniji
Bulletin of the National Research Centre, Volume 45, pp 1-8; doi:10.1186/s42269-021-00529-7

Background Heavy metal accumulation in the ecosystem constitutes a potential toxic effect which is hazardous to human health. Increasing environmental pollution has necessitated the use of cattle egrets to evaluate the levels of heavy metal contamination, to establish their use in biomonitoring of heavy metals and to provide data for monitoring pollution in the environment. Results The present study assessed the utilization of Bubulcus ibis in monitoring pollution in five abattoirs, namely Agege, Bariga, Kara, Itire and Idi-Araba, all situated in Lagos State. The concentration of five (5) heavy metals, cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) was determined in the liver, muscle and feather of Bubulcus ibis using the atomic absorption spectrophotometer. The trend of metal accumulation was in the order: Zn > Cu > Pb > Cd > Ni for all the sampled tissues. The mean tissue concentrations of the metals were significantly different (p < 0.05) among the sites. The highest levels of metal concentration were reported in the liver in all the locations. Mean concentration of Cd in Kara (0.003 ± 0.00058) was significantly (p < 0.05) higher than those found at Agege (0.0013 ± 0.00058) and Idi-Araba (0.001 ± 0.001). A significant difference (p < 0.05) was also observed between the mean concentrations of Cu in Bariga (0.01 ± 0.001) and Idi-Araba (0.003 ± 0.001). Conclusion All the studied heavy metals were present in the liver, muscle and feathers of the cattle egrets. The contamination levels were ascertained from the study which indicated that cattle egrets are useful in biomonitoring studies and the generated data will serve as baseline data which could be compared with data from other locations for monitoring heavy metal pollution.
Doaa Filali, , Mohammad Akram, Feeroz Babu, Izhar Ahmad
Journal of Inequalities and Applications, Volume 2021, pp 1-20; doi:10.1186/s13660-021-02598-8

This article aims to introduce and analyze the viscosity method for hierarchical variational inequalities involving a ϕ-contraction mapping defined over a common solution set of variational inclusion and fixed points of a nonexpansive mapping on Hadamard manifolds. Several consequences of the composed method and its convergence theorem are presented. The convergence results of this article generalize and extend some existing results from Hilbert/Banach spaces and from Hadamard manifolds. We also present an application to a nonsmooth optimization problem. Finally, we clarify the convergence analysis of the proposed method by some computational numerical experiments in Hadamard manifold.
, Kalle Ruttik, Riku Jäntti, Jyri Hämäläinen
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-24; doi:10.1186/s13638-021-01965-9

The aim of this work is to study the impact of small receiver displacement on a signal propagation in a typical conference room environment at a millimeter wave frequency of 60 GHz. While channel measurements provide insights on the propagation phenomena, their use for the wireless system performance evaluation is challenging. Whereas, carefully executed three-dimensional ray tracing (RT) simulations represent a more flexible option. Nevertheless, a careful validation of simulation methodology is needed. The first target of this article is to highlight the benefits of an in-house built three-dimensional RT tool at 60 GHz and shows the effectiveness of simulations in predicting different characteristics of the channel. To validate the simulation results against the measurements, two different transmitter (Tx) positions and antenna types along with ten receiver (Rx) positions are considered in a typical conference room. In first system configuration, an omnidirectional antenna is placed in the middle of the table, while in the second system configuration a directed horn antenna is located in the corner of the meeting room. After validating the simulation results with the measurement data, in the second part of this work, the impact of a small change, i.e., 20 cm in the receiver position, is studied. To characterize the impact, we apply as performance indicators the received power level, root mean square delay spread (RMS-DS) and RMS angular spread (RMS-AS) in azimuth plane. The channel characteristics are considered with respect to the direct orientation (DO), i.e., the Rx antenna is directed toward the strongest incoming path. Different antenna configurations at the Tx and Rx side are applied to highlight the role of antenna properties on the considered channel characteristics. Especially, in the second system configuration the impact of different antenna half power beamwidth on different considered channel characteristics is highlighted through acquired simulation results. The validation of results shows the RMS error of only 2–3 dB between the measured and simulated received power levels for different Tx configurations in the direction of DO. Results indicate that only a small change of the Rx position may result a large difference in the received power level even in the presence of line-of-sight between the Tx and Rx. It is found that the STD of received power level across the room increases with the decrease in HPBW of the antenna. As can be expected, directed antennas offer lower value of RMS-DS and RMS-AS compared with isotropic antenna.
, Jaime Garcia-Reinoso, Aitor Zabala, Pablo Serrano, Albert Banchs
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-27; doi:10.1186/s13638-021-01962-y

The fifth generation (5G) of mobile networks is designed to accommodate different types of use cases, each of them with different and stringent requirements and key performance indicators (KPIs). To support the optimization of the network performance and validation of the KPIs, there exist the necessity of a flexible and efficient monitoring system and capable of realizing multi-site and multi-stakeholder scenarios. Nevertheless, for the evolution from 5G to 6G, the network is envisioned as a user-driven, distributed Cloud computing system where the resource pool is foreseen to integrate the participating users. In this paper, we present a distributed monitoring architecture for Beyond 5G multi-site platforms, where different stakeholders share the resource pool in a distributed environment. Taking advantage of the usage of publish-subscribe mechanisms adapted to the Edge, the developed lightweight monitoring solution can manage large amounts of real-time traffic generated by the applications located in the resource pool. We assess the performance of the implemented paradigm, revealing some interesting insights about the platform, such as the effect caused by the throughput of monitoring data in performance parameters such as the latency and packet loss, or the presence of a saturation effect due to software limitations that impacts in the performance of the system under specific conditions. In the end, the performance evaluation process has confirmed that the monitoring platform suits the requirements of the proposed scenarios, being capable of handling similar workloads in real 5G and Beyond 5G scenarios, then discussing how the architecture could be mapped to these real scenarios.
, , Aslı Mete, Aykut Başer, Ömer Levent Tuncay, Ali Ersin Zümrütbaş
African Journal of Urology, Volume 27, pp 1-6; doi:10.1186/s12301-021-00159-5

Background To assess the learning curve in laparoscopic radical prostatectomy (LRP) performed by a single surgeon who had a healthcare career as a surgical first assistant for 2 years in high-volume centers treating > 150 cases per year. Methods The records of 80 LRP cases performed between October 2017 and August 2018 by a single surgeon were consecutively divided into four groups (groups A = first 20 cases, B = second 20 cases, C = third 20 cases, and D = last 20 cases). The groups were compared in terms of surgical and functional outcomes with a minimum follow-up of 6 months. Results Clinical and surgical stages of the four groups were similar between groups. The operative time (126.8 ± 5.48 min; P = 0.001) and time of removal of the drain (1.65 ± 0.93 days; P = 0.029) were significantly lower in group D; however, hospitalization, catheterization time, and blood loss were similar between groups. The complication rate was low. No patient had a visceral injury, and there were no procedures needed to open conversion. The positive surgical margin (PSM) rates were similar between groups. In terms of continence and potency, all groups were similar at the 6th-month follow-up after surgery. Conclusions Our results showed that prior experience in laparoscopic surgery as a surgical first assistant in a high-volume center improves the learning curve and oncological and functional outcomes, and helps to minimize the complication rate
S. A. Adebayo, A. A. Salami, A. O. Takure, O. A. Fasola, I. B. Ulasi, J. I. Nwadiokwu, O. B. Shittu
African Journal of Urology, Volume 27, pp 1-6; doi:10.1186/s12301-021-00157-7

Background Renal cell carcinoma metastases to the spleen are rare. At the time of this report, only 20 cases of splenic metastases from RCC have been published in the literature. To our knowledge, our report is the first splenic metastasis from a chromophobe RCC. Case presentation A 44-year-old woman presented with clinical and radiological features of splenic metastasis from RCC, 12 years after radical nephrectomy for chromophobe RCC. Computed tomography, laparotomy and splenectomy revealed metastases to the spleen and retroperitoneal lymph nodes. Conclusion Splenic metastasis from RCC is uncommon, and rarer still from a chromophobe subtype of RCC. Surgical management of the metastasis is recommended.
Said Alfin Khalilullah, Untung Tranggono, Ahmad Zulfan Hendri, R. Danarto
African Journal of Urology, Volume 27, pp 1-6; doi:10.1186/s12301-021-00163-9

Background Most of the outcomes after radical cystectomy (RC) are directly associated with the type of urinary diversion. This study sets out to evaluate the outcomes of ileal conduit (IC) and transuretero-cutaneostomy (TUC) urinary diversion after RC. Methods This retrospective study included 52 patients (IC, n = 30; TUC, n = 22) at Dr. Sardjito Hospital between January 2014 and December 2019. The clinical outcomes were compared using Chi-squared tests and independent t tests. Multivariable logistic regression analysis was performed to determine the odds of developing related complications. Results Demographically, both groups were similar in terms of age, gender, ASA score, staging, body mass index, and comorbidities. IC was associated with a high incidence of postoperative complications than TUC (56.7% vs. 27.3%; p = 0.035). Long-term postoperative complications stoma stenosis was more common in the TUC than IC (p = 0.010). Multivariate analysis showed TUC was a significant predictor for stoma stenotic with odds ratio of 1.29 (95% confidence interval, 1.03–1.62; p = 0.006). Meanwhile, metabolic change was found higher in IC (p = 0.047). No difference between the rate of required blood transfusion, postoperative ileus, re-operation, and anastomotic stricture in both groups. Operative time (p = 0.000) and length of stay (p = 0.002) were lower in patients who underwent TUC. The hospitalized cost was also lower in TUC ($ 2311.8 ± 1448 for IC vs. $ 1844.2 ± 948.8 for TUC; p = 0.005). Nonetheless, the follow-up cost was higher in the TUC but not statistically significant. Additionally, there was no difference between the overall satisfaction and diversion-related symptoms scores in both groups. The psychological score was better in IC groups. Conclusions Both of these techniques can be an option in a urinary diversion after RC with various advantages and disadvantages. TUC provides reduced complication rates, operative time, shorter length of stay, and hospitalized costs, but IC may reduce postoperative stoma stenosis complications and better psychological function.
Azar Vahabisani,
Environmental Systems Research, Volume 10, pp 1-10; doi:10.1186/s40068-021-00229-1

Over the past decades, a large amount of petroleum pollutants has been released into the environment resulting from various activities related to petrochemicals. The discharge of wastewater with petrochemicals can pose considerable risk of harm to the human health and the environment. The use of adsorbents has received much consideration across the environmental field as an effective approach for organic pollutant removal. There is a particular interest in the use of biomass adsorbent as a promising environmentally-friendly and low-cost option for removing pollutants. In this article, we present a review of biomass-derived adsorbents for the removal of petroleum pollutants from water. The features of different adsorbents such as algae, fungi, and bacteria biomasses are summarized, as is the process of removing oil and PAHs using biomass-derived adsorbents. Finally, recommendations for future study are proposed.
Yasir M Khayyat
Egyptian Liver Journal, Volume 11, pp 1-5; doi:10.1186/s43066-021-00095-7

Background The prevention of portal hypertensive complications, including upper gastrointestinal bleeding, is critically important and achieved only through the use of upper endoscopy for the management of oesophageal gastric varices (EGVs). There is a paucity of data and limited utilization of non-invasive predictive parameters to guide the selection of patients who may benefit from endoscopic surveillance, especially in cirrhotic patients with coexistent portal vein thrombosis. Results The study was conducted in eight hospitals in the western region of Saudi Arabia over the period of 2015–2017. Among 1349 chronic liver disease patients, eighty-five patients with complete endoscopic findings were included in the study. Twenty-eight patients were diagnosed with non-malignant PVT. Twenty-five patients (89%) developed oesophageal varices, compared with 57 patients with cirrhosis without PVT. A predictive factor for the development of oesophageal varices of statistical significance was hypoalbuminemia in PVT patients (p=0.04). No statistically significant differences were found in other biochemical markers (p<0.05) between the PVT and non-PVT groups. Conclusions The prevalence of oesophageal varices is increased in PVT patients. Serum albumin can be utilized as a predictor of varices development in cirrhosis patients.
Ayman Hussein, Hamdy Ibrahim, Hazem Mashaly, Sameh Hefny, Abdelrahman El Gayar
The Egyptian Journal of Neurology, Psychiatry and Neurosurgery, Volume 57, pp 1-8; doi:10.1186/s41983-021-00305-4

Background Percutaneous pedicle screw technique is relatively a recent technique that evolved the concept of posterior spinal instrumentation, utilizing familiar fluoroscopic landmarks to guide the procedure of screws insertion, which despite being technically demanding, it avoids the Musculo-ligamentous damage associated with the conventional posterior technique. Aim of the work This study aims to report our experience in managing traumatic and degenerative spine pathologies by the minimally invasive percutaneous technique and assessing its radiological and functional outcome. Materials and methods A prospective observational study that included the analysis of the functional, operative, biochemical, and radiological outcomes of 20 patients who underwent uniplanar fluoroscopic-guided dorsal and/or lumbar percutaneous pedicle screw fixation procedures with or without fusion using the sextant, longitude, and Spineart system and any reported complications between January 2018 and December 2019. Results The clinical and radiological analysis of 100 percutaneous pedicle screws in degenerative (n:11) and traumatic (n:9) dorsal and/or lumbar cases revealed that the biomechanical stabilizing characteristics are comparable to the conventional posterior approach with the added benefits of the paraspinal muscle-sparing. Satisfactory functional outcome represented in the improvement of the postoperative back pain visual analog score and Oswestry Disability Index Score with acceptable morbidity and complications rate was noticed. Conclusions Percutanous pedicle screw fixation is a landmark in the evolution of the minimally invasive spine surgery which can be a safe alternative to the conventional posterior muscle stripping technique with a comparable functional and radiological outcome and good biomechanical profile and an acceptable morbidity rate.
Haiyan Ye, Jiabao Jiang
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-10; doi:10.1186/s13638-021-01977-5

The lack of spectrum resources restricts the development of wireless communication applications. In order to solve the problems of low spectrum utilization and channel congestion caused by the static division of spectrum resource, this paper proposes an optimal linear weighted cooperative spectrum sensing for clustered-based cognitive radio networks. In this scheme, different weight values will be assigned for cooperative nodes according to the SNR of cognitive users and the historical sensing accuracy. In addition, the cognitive users can be clustered, and the users with the better channel characteristics will be selected as cluster heads for gathering the local sensing information. Simulation results show that the proposed scheme can obtain better sensing performance, improve the detection probability and reduce the error probability.
Yanxi Huang, Fangzhou Zhu, Liang Liu, Wezhi Meng, Simin Hu, Renjun Ye, Ting Lv
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-21; doi:10.1186/s13638-021-01978-4

The security of wireless routers receives much attention given by the increasing security threats. In the era of Internet of Things, many devices pose security vulnerabilities, and there is a significant need to analyze the current security status of devices. In this paper, we develop WNV-Detector, a universal and scalable framework for detecting wireless network vulnerabilities. Based on semantic analysis and named entities recognition, we design rules for automatic device identification of wireless access points and routers. The rules are automatically generated based on the information extracted from the admin webpages, and can be updated with a semi-automated method. To detect the security status of devices, WNV-Detector aims to extract the critical identity information and retrieve known vulnerabilities. In the evaluation, we collect information through web crawlers and build a comprehensive vulnerability database. We also build a prototype system based on WNV-Detector and evaluate it with routers from various vendors on the market. Our results indicate that the effectiveness of our WNV-Detector, i.e., the success rate of vulnerability detection could achieve 95.5%.
, Lei Lei, Thang X. Vu, Symeon Chatzinotas, Sumei Sun, Björn Ottersten
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-27; doi:10.1186/s13638-021-01960-0

In unmanned aerial vehicle (UAV)-assisted networks, UAV acts as an aerial base station which acquires the requested data via backhaul link and then serves ground users (GUs) through an access network. In this paper, we investigate an energy minimization problem with a limited power supply for both backhaul and access links. The difficulties for solving such a non-convex and combinatorial problem lie at the high computational complexity/time. In solution development, we consider the approaches from both actor-critic deep reinforcement learning (AC-DRL) and optimization perspectives. First, two offline non-learning algorithms, i.e., an optimal and a heuristic algorithms, based on piecewise linear approximation and relaxation are developed as benchmarks. Second, toward real-time decision-making, we improve the conventional AC-DRL and propose two learning schemes: AC-based user group scheduling and backhaul power allocation (ACGP), and joint AC-based user group scheduling and optimization-based backhaul power allocation (ACGOP). Numerical results show that the computation time of both ACGP and ACGOP is reduced tenfold to hundredfold compared to the offline approaches, and ACGOP is better than ACGP in energy savings. The results also verify the superiority of proposed learning solutions in terms of guaranteeing the feasibility and minimizing the system energy compared to the conventional AC-DRL.
Dumitru Baleanu, Muhammad Qamar Iqbal, Azhar Hussain, Sina Etemad,
Advances in Difference Equations, Volume 2021, pp 1-24; doi:10.1186/s13662-021-03356-2

The main intention of this article is that new techniques of existence theory are used to derive some required criteria pertinent to a given fractional multi-term problem and its inclusion version. In such an approach, we do our research on a fractional integral equation corresponding to the mentioned BVPs. In more precise words, by virtue of this integral equation, we construct new operators which belong to a special category of functions named α-admissible and α-ψ-contraction maps coupled with operators having (AEP)-property. Next, by considering some new properties on the existing Banach space having properties (B) and $(C_{\alpha })$ ( C α ) , our argument for ensuring the existence of solutions is completed. In addition, we also add two simulative examples to review our findings by a numerical view.
Dalia Salaheldin Elmesidy, Eman Ahmed Mohammed Omar Badawy, Rasha Mohammed Kamal, Emad Salah Eldin Khallaf, Rasha Wessam AbdelRahman
Egyptian Journal of Radiology and Nuclear Medicine, Volume 52, pp 1-12; doi:10.1186/s43055-021-00480-7

Background Axillary nodal status is crucial for the management of cases with recently diagnosed breast cancer; usually addressed via axillary ultrasonography (US) along with tissue sampling in case of suspicion. Axillary nodal dissection and sentinel biopsy may be done, but are rather invasive, carrying a potential complication risk, which raises the need for non-invasive, reliable, pre-operative axillary imaging. We aimed at evaluating the performance of diffusion-weighted imaging (DWI) regarding preoperative axillary evaluation, using functional information derived from diffusion capacity differences between benign and malignant tissue. We included 77 axillary nodes from 77 patients (age range 20–78 years, mean 50 ± 12.6 SD) in our prospective study, presenting with variable clinical breast complaints, all scoring BIRADS 4/5 on sonomammography (SM). They underwent axillary evaluation by both US and DW-MRI where US classified nodes into benign, indeterminate, or malignant by evaluating nodal size, shape, cortical thickness, and hilar fat. Qualitative DWI classified them into either restricted or not and a cut-off apparent diffusion coefficient (ADC) value was calculated to differentiate benign and malignant nodal involvement. Results for each modality were correlated to those of final histopathology, which served as the standard of reference. Results The calculated sensitivity, specificity, accuracy, PPV, and NPV for US was 100%, 36.6%, 75.3%, 71.2%, and 100%, respectively. Statistical indices for qualitative DWI were 76.6%, 63.3%, 76.6%, 63.3%, and 71.4%, respectively (P value < 0.001). The calculated cut off value for ADC between infiltrated and non-infiltrated nodes was 0.95 × 10−3 mm2/s concluding statistical indices of 76.6%, 63.3%, 76.6%, 63.3%, and 71.4%, respectively (P value < 0.001). Conclusion Combining DW-MRI to conventional US improves diagnostic specificity and overall accuracy of preoperative axillary evaluation of patients with recently discovered breast cancer.
Dalia Abdelhady, Amany Abdelbary, Ahmed H. Afifi, Alaa-Eldin Abdelhamid, Hebatallah H. M. Hassan
Egyptian Journal of Radiology and Nuclear Medicine, Volume 52, pp 1-15; doi:10.1186/s43055-021-00473-6

Background Breast cancer is the most prevalent cancer among females. Dynamic contrast-enhanced MRI (DCE-MRI) breast is highly sensitive (90%) in the detection of breast cancer. Despite its high sensitivity in detecting breast cancer, its specificity (72%) is moderate. Owing to 3-T breast MRI which has the advantage of a higher signal to noise ratio and shorter scanning time rather than the 1.5-T MRI, the adding of new techniques as diffusion tensor imaging (DTI) to breast MRI became more feasible. Diffusion-weighted imaging (DWI) which tracks the diffusion of the tissue water molecule as well as providing data about the integrity of the cell membrane has been used as a valuable additional tool of DCE-MRI to increase its specificity. Based on DWI, more details about the microstructure could be detected using diffusion tensor imaging. The DTI applies diffusion in many directions so apparent diffusion coefficient (ADC) will vary according to the measured direction raising its sensitivity to microstructure elements and cellular density. This study aimed to investigate the diagnostic accuracy of DTI in the assessment of breast lesions in comparison to DWI. Results By analyzing the data of the 50 cases (31 malignant cases and 19 benign cases), the sensitivity and specificity of DWI in differentiation between benign and malignant lesions were about 90% and 63% respectively with PPV 90% and NPV 62%, while the DTI showed lower sensitivity and specificity about 81% and 51.7%, respectively, with PPV 78.9% and NPV 54.8% (P-value ≤ 0.05). Conclusion While the DWI is still the most established diffusion parameter, DTI may be helpful in the further characterization of tumor microstructure and differentiation between benign and malignant breast lesions.
, Ahmed S. El-Hawary, Ahmed E. Sadek
Bulletin of the National Research Centre, Volume 45, pp 1-6; doi:10.1186/s42269-021-00531-z

Background Authorship trends in medical journals were studied in many disciplines, mostly in western countries' journals. We aimed at studying the authorship trends in the Egyptian Orthopaedic Journal as an example of a specialized Egyptian medical journal. Results A total of 397 articles were eligible for analysis. The mean number of authors per article was 2 ± 1 (range from 1 to 6), 161 (40.6%) articles were single authorship. The degree of the first author was reported in 305 (76.6%), the first author carried an M.D. degree in 302 (99%) articles, and in three (1%), the first author carried a master’s degree. No authors with a bachelor's degree were reported. Forty-two institutions contributed to the publications, 14 (33.3%) international and 28 (66.7%) Egyptian national institutions. In 368 (92.7%) articles, all the authors were from the same institution, and 29 (7.3%) articles were published as a cooperation between different institutions with a mean 1.1 ± 0.3 institution per article. International contribution to the journal was found in 21 (5.3%) articles. The orthopedic department from Cairo university was the most contributing department to the journal publications. Conclusions The old trend of single authorship prevails in the journal publications with a notable deficiency in young researchers’ contribution to the journal and low incidence of international contribution and poor national institution cooperation.
Zeyad Elsaraf, Abbas Ahmed, Faheem Ahmad Khan, Qasim Zeeshan Ahmed
EURASIP Journal on Wireless Communications and Networking, Volume 2021, pp 1-14; doi:10.1186/s13638-021-01961-z

In the next generation of mobile communication networks, unprecedented challenges are required to be met, such as much higher data rates and spectrum efficiency, lower latency, and massive connectivity. Non-orthogonal multiple access (NOMA) has recently been proposed as a promising technology to achieve much superior spectral efficiency compared to conventional orthogonal multiple access techniques employed in present communication systems. A salient feature of NOMA is its use of successive interference cancellation (SIC) to decode users’ information when multiple users are allowed to transmit in same time/frequency/code domain. In this paper, we aim to exploit an aspect of SIC, namely the availability of other users’ data to realize a cooperative NOMA system. EXtrinsic information transfer (EXIT) charts are utilized to examine the performance of proposed system in terms of user fairness while employing IRregular convolutional codes (IRCC)s. The EXIT chart using IRCC evaluates the convergence analysis for the proposed system. Further, to evaluate the system performances in cooperative NOMA system, we have derived the expressions for the achievable rates which are obtained independently and utilized them in evaluating the experimental data for the proposed NOMA model.
Natasa Skrbic, Vaidotas Kisielius, Ann-Katrin Pedersen, Sarah C. B. Christensen, Mathilde J. Hedegaard, Hans Christian Bruun Hansen,
Environmental Sciences Europe, Volume 33, pp 1-11; doi:10.1186/s12302-021-00486-y

Background Ptaquiloside (PTA), caudatoside (CAU) and ptesculentoside (PTE) are carcinogenic illudane glycosides found in bracken ferns (Pteridium spp.) world-wide. The environmentally mobile PTA entails both acute and chronic toxicity. A comparable risk might be associated with the structurally similar CAU and PTE. It is of great health concern if these compounds are present in drinking water, however, it is currently unknown if these compounds can detected in wells in bracken-dominated regions. This study investigates the presence of PTA, CAU, PTE, and their corresponding hydrolysis products pterosins B (PtB), A (PtA) and G (PtG) in water wells in Denmark, Sweden and Spain. Water samples from a total of 77 deep groundwater wells (40–100 m) and shallow water wells (8–40 m) were collected and preserved in the field, pre-concentrated in the laboratory and analysed by liquid chromatography–mass spectrometry (LC–MS). Results Deep groundwater wells contained neither illudane glycosides nor their pterosins. However, seven private shallow wells contained at least one of the illudane glycosides and/or pterosins at concentrations up to 0.27 µg L−1 (PTA), 0.75 µg L−1 (CAU), 0.05 µg L−1 (PtB), 0.03 µg L−1 (PtA) and 0.28 µg L−1 (PtG). This is the first finding of illudane glycosides and pterosins in drinking water wells. Conclusions Detected concentrations of illudane glycosides in some of investigated wells exceeded the suggested maximum tolerable concentrations of PTA, although they were used for drinking water purpose. Contaminated wells were shallow with neutral pH and lower electric conductivity compared to deep groundwater wells with no illudane glycosides nor pterosins.
Modou Ndiaye, Mouhamed Jalloh, Madina Ndoye, Samba Thiapato Faye, Saint Charles Nabab Kouka, Ndiaga Seck Ndour, Mouhamadou Moustapha Mbodji, El Hadji Malick Diaw, Ibrahima Louis Mane, Issa Labou, et al.
African Journal of Urology, Volume 27, pp 1-5; doi:10.1186/s12301-021-00155-9

Background Magnetic resonance imaging (MRI)-guided prostate biopsy has a higher sensitivity than the ultrasound-guided biopsy, but its realization requires a dedicated interventional MRI, specific material, which is not available in our context; hence, ultrasound-guided biopsy remains of great interest. Currently, ultrasound-guided biopsy outside of a clinical trial is the gold standard for the diagnosis of prostate cancer. The objective of our work is to evaluate our practice of transrectal ultrasound-guided prostate biopsy using an endorectal probe by describing the technique and evaluating the morbidity and results. Methods This is a descriptive study of ultrasound-guided prostatic biopsies performed over a 2-year period. The parameters studied were frequency of the procedure, age, rectal examination findings, total PSA level, prostate biopsy morbidities and results. Descriptive statistics were performed, and comparison of qualitative variables was made by the Chi-square test with statistical significance set for α < 5% Results Two hundred and thirty-one patients were included over a two-year period. The mean age of our patients was 65 ± 8.2 years. Rectal examination finding was suspicious in 36.9% and the median total PSA was 19.8 ng/ml (0.1-5936 ng/ml). Seventy-seven percent of patients reported their pathology results. Prostatic adenocarcinoma was the most common finding accounting for 53.7% of results. Complications were observed in 16 patients (6.9%) with a predominance of initial hematuria, voiding pain and fever. Conclusion In our series, the cancer detection rate was significant and the complications rate was acceptable at 6.9%.
Duan Wu,
Boundary Value Problems, Volume 2021, pp 1-9; doi:10.1186/s13661-021-01516-7

The aim of this paper is to study the oscillation of solutions of the nonlinear degenerate elliptic equation in the Heisenberg group $H^{n}$ H n . We first derive a critical inequality in $H^{n}$ H n . Based on it, we establish a Picone-type differential inequality and a Sturm-type comparison principle. Then we obtain an oscillation theorem. Our result generalizes the related conclusions for the nonlinear elliptic equations in $R^{n}$ R n .
Maxwell Okuja, Faith Ameda, Henry Dabanja, Felix Bongomin, Samuel Bugeza
African Journal of Urology, Volume 27, pp 1-9; doi:10.1186/s12301-021-00162-w

Background Prostate disorders are among the leading causes of morbidity and mortality in men above the age of 40 years globally. Serum prostate-specific antigen (PSA) levels may be used to screen men at risk of prostate cancer and determine choice of medical treatment in benign prostatic hyperplasia (BPH) and evaluation of patients with prostatitis, while prostate sonography determines prostate volume (PV) and detects nodules. BPH may exhibit distinct hypoechoic, isoechoic, or hyperechoic nodules in the transition zone, whereas hypoechoic nodules in the peripheral zone are diagnostic for prostate cancer in over 50% of cases. In this study, we aimed at determining the relationship between serum PSA levels and transrectal prostate sonographic findings among asymptomatic Ugandan males. Methods Ugandan males above 30 years of age or older without lower urinary tract symptoms were cross-sectionally enrolled into the study. Serum PSA determination and transrectal ultrasound were performed. Association between PSA levels and PV was assessed using Spearman’s correlation coefficients (ρ). Results A total of 277 men were studied. The median serum PSA level was 1 (95% CI: 1–2). Most (n = 217, 78.3%) participants had serum PSA levels ≤ 4 ng/ml. The median sonographic PV was 26 (95% CI: 26–29) mls. One hundred and fifty-five (56.0%) participants had PV between 25 and 50 mls. Both PSA levels and PV progressively increased with age from 0.9 ng/ml and 22 mls in the 30–39 year age group to 7 ng/ml and 38 mls in the 60–69 year age group, respectively. PSA levels weakly correlated with PV (ρ = 0.27) (p < 0.0001). One hundred and thirty (47%) participants had prostatic nodules. Of these, 100 (77%) had features of benign nodules and 23% had suspicious nodules for prostate cancer. The median (range) serum PSA level in those with nodules was 2.0 (0.1–16.0) ng/ml and for those without nodules was 1.1 (0.1–8.0) ng/ml (p < 0.0001). Conclusions Serum PSA has a weak direct correlation with PV and not a reliable marker for the prediction of presence or absence of prostatic nodules in asymptomatic adult males.
Hiroyuki Nagafuchi, Hiroyuki Shimizu, Kaori Yamada, Kenta Shono, Tetsuya Ogawa
Renal Replacement Therapy, Volume 7, pp 1-9; doi:10.1186/s41100-021-00335-x

Background Multiple organ dysfunction syndrome is the leading cause of death in pediatric intensive care units and can be very critical when combined with shock and disseminated intravascular coagulation (DIC). Currently, there is no effective treatment. We developed a new hemodiafiltration (HDF) method called plasma HDF (PHDF) that uses fresh frozen plasma as replacement fluid and investigated the safety and efficacy of this treatment. Methods We enrolled critically ill children with (1) a Pediatric Logistic Organ Dysfunction 2 (PELOD-2) score ≥ 14, (2) a Japanese Ministry of Health and Welfare (JMHW) DIC score ≥ 7, (3) a vasoactive inotropic score (VIS) ≥ 10, and (4) a serum total protein concentration ≤ 5.0 g/dL. PHDF was performed for 5 h and then switched to continuous HDF. The primary endpoint was the 28-day mortality rate. Secondary endpoints included assessment of vital signs, blood test data, and fluid balance from PHDF start to day 7. Results Nine patients (four males and five females) between 3 days and 40 months of age, weighing 2.1–13 kg, met the inclusion criteria. Although the median PMR was 0.94 (0.71–0.96), the 28-day mortality rate was 22.2% (2/9). One hour after the start of PHDF, there was an increase in mean arterial pressure and central venous pressure and a decrease in heart rate; by day 7, there was a significant decrease in the PELOD-2 score, the JMHW DIC score, and the VIS. Hypoproteinemia also improved the day after PHDF. Water balance was able to remain negative after day 2. Conclusions PHDF was found to be effective in the treatment of DIC and circulatory failure by supplementing coagulation and antithrombotic factors as well as by raising colloid osmotic pressure to increase circulating blood volume. PHDF has been shown to be a safe and useful treatment for critically ill children and has the potential to improve 28-day survival.
Sajid Hameed, Lubna Ashraf Jafri, Dureshahwar Kanwar
The Egyptian Journal of Neurology, Psychiatry and Neurosurgery, Volume 57, pp 1-5; doi:10.1186/s41983-021-00304-5

Background Guillain-Barre syndrome (GBS) is an acute polyradiculoneuropathy, often preceded by an infection. Rarely, it is preceded by a surgical procedure. Most of the postsurgical GBS cases are reported with the neurosurgical, gastrointestinal, orthopedic, and cardiac procedures. GBS is rarely reported after a coronary artery bypass grafting (CABG). To date, only 12 cases have been reported in the literature. Our case is 13th in number and the first case from Pakistan. Case presentation We report a case of a 54-year-old man presented with acute flaccid quadriparesis and areflexia after a CABG procedure. He was subsequently diagnosed with an acute inflammatory demyelinating polyneuropathy (AIDP) variant of GBS and underwent five sessions of plasmapheresis. His weakness improved and could ambulate unassisted on follow-up visits. Conclusion GBS is a potentially treatable condition if timely diagnosed and managed. It should be considered in every patient presenting with an acute-onset weakness after surgery.
, Kang Jia, Caizhi Sun, Yanqiang Li, Chao Zhang, Shixiong Zheng
Advances in Bridge Engineering, Volume 2, pp 1-11; doi:10.1186/s43251-021-00035-w

The objective of this paper is to expediently expose the seismic performance pertinent to demand and capacity of general long-span suspension bridges crossing active faults. Firstly three dimensional finite element model of the ordinary long-span suspension bridge is established based on the powerful and attractive finite element software ANSYS. Secondly a series of appropriate fault ground motions with different target final permanent displacements (Tectonic displacements or ground offset) in the direction perpendicular to the fault plane are assumed and applied to the employed long-span suspension bridge. And then the Newmark method is utilized to solve the equation of motion of the long-span suspension bridge structure subjected to fault ground motions in the elastic range. Finally some important conclusions are drawn that the final permanent displacements in the direction perpendicular to the fault plane has significant influence on the seismic responses and demands of general long-span suspension bridges crossing active faults. And the resultant conclusions deliver explicitly and directly specifications and guidelines for seismic design of ordinary long-span suspension bridges across fault-rupture zones.
, Jorge Chica Olmo
Geoenvironmental Disasters, Volume 8, pp 1-12; doi:10.1186/s40677-021-00180-4

Natural disasters have been a significant hurdle in the economic growth of middle-income developing countries. Thailand has also been suffering from recurring flood disasters and was most which are severely affected during the 2011 floods. This paper aims to identify the various factors that impact the speed of disaster recovery among the Small and Medium Enterprises (SMEs) severely affected by the floods in Pathumthani province in central Thailand, and how it is related to its speed decision of neighbours SMEs. The methodology adopts a spatial econometric model, to analysis and understand each of the chosen factors’ impact. The findings include the impact of disaster resilience, mitigation and planning at the SME level as well as the government level. The absence of accurate perception of actual risk, flood insurance and disaster management planning before the 2011 floods had contributed to the severity of the impacts during the 2011 floods.
Suleyman Guven, Sebnem Alanya Tosun, Emine Seda Guvendag Guven
Middle East Fertility Society Journal, Volume 26, pp 1-7; doi:10.1186/s43043-021-00054-7

Background The main purpose of this study was to investigate the effect of mean blastomere diameter (MBD) on pregnancy rates in in vitro fertilization (IVF) cases undergoing the long agonist cycle protocol. A total of 84 cases were evaluated within the scope of this observational prospective study. All cases were normoresponders, under 35 years old, with the long agonist protocol applied and single embryo (grade I or II) transfer performed. On the third day after ICSI, each embryo selected for transfer was subjected to measurement of the mean blastomere diameter (MBD) at ×25 magnification. Results The mean female age was 30.14 ± 3.32 years, and the total clinical pregnancy rate was 33.3%. In the group that got pregnant, MBD was found to be statistically significantly higher than in the nonpregnant group. In terms of predicting clinical pregnancy, when the MBD value of 49.73 μm was accepted as the best cutoff value, the sensitivity was calculated as 75% and specificity as 53.6%. Clinical pregnancy rate was 18.9% in cases below this value, whereas clinical pregnancy rate was 44.7% in cases with this value and above. In other words, when the MBD value rose above 49.73 μm from a value below 49.73 μm, the clinical pregnancy rate increased by an average of 2.3 times. Conclusions With MBD measurement, it is possible to select the embryo with the best implantation capability in microinjection cycles with the long luteal agonist protocol.
International Journal of Geo-Engineering, Volume 12, pp 1-26; doi:10.1186/s40703-020-00139-8

This paper reports a finite element study to identify the locations of crack initiation in a homogeneous earthen dam at its post-construction and reservoir operation stages. The steady state and transient analyses, including reservoir rise-up and drawdown conditions, are simulated to identify the favorable conditions and locations of crack generation. The behavioral response of the dam is represented in terms of the developed total stress, horizontal deformations of the faces, strain accumulation in the dam, and the differential settlement of the dam base. The locations of post-construction cracks are identified based on the negative minor principal stresses developed on the dam faces. For both single-lift and multiple-lift modeling techniques, the upstream face of the dam is found to be the most favorable location for the crack generation. For transient reservoir operations (rise-up and drawdown scenarios), it is identified that hydraulic fracturing may occur on either faces of the dam at specific heights, governed by the minor principal stresses becoming lesser than the developed pore-water pressure. Depending on whether the reservoir drawdown occurs before or after the attainment of steady-state phreatic level within the body of the dam, the pore-water pressure distribution within the dam are found notably different. This results in hydraulic fracturing occurring at different faces of the dam and at different heights. It is important to have a thorough understanding of the tentative location of the cracks developed in homogeneous earthen dams so that proper mitigation measure can be adopted as per requirement.
Dalia M. Elfawy, Mohmmed Abd Elkalek, Ehab Hamed, Samer Ibrahem, Doaa M. A. Elzoghby, Waleed Abdalla
Ain-Shams Journal of Anesthesiology, Volume 13, pp 1-7; doi:10.1186/s42077-021-00141-x

Background Acute respiratory distress syndrome (ARDS) constitutes a clinical phenotype of severe lung injury associated with many causes. Endothelial activation and injury is a component of ARDS. The release of von Willebrand factor (vWF) indicates direct endothelial cell damage has occurred, and this can be used as a marker of endothelium injury. The aim of the study was to investigate the diagnostic value of vWF antigen as a determinant of early detection of ARDS in comparison to interleukin-6 (IL-6) as a control biomarker. vWF antigen and IL-6 were measured in 60 patients who were at risk of developing ARDS on T0 (at the start of the study), T48 (after 48 h), and T72 (after 72 h). Results Higher vWF Ag levels were seen in patients at risk of developing ARDS with direct cause of lung injury than those with indirect causes. Include groups I and II. There was a highly significant increase between the “at risk of developing ARDS” patients, VWF Ag, and IL-6 levels. The results were recorded at T0 (i.e., at start of the study baseline reading), T48 (after 48 h), and T72 (after 72 h), p 0.001 and p 0.05, respectively. A value of vWF Ag of 447% on the 3rd day of ARDS showed a sensitivity of 94.9% and specificity 56.7% compared to IL-6 at 246 pg/ml with 79.5% sensitivity and 52.4% specificity. As a comparison between VWF and IL6 levels among ARDS patients, they both show statistical correlation together. Conclusion The results of our study point out to VWF as a sensitive and good diagnostic marker for ARDS diagnosis.
Zonglong Bai, Liming Shi, Jesper Rindom Jensen, Jinwei Sun, Mads Græsbøll Christensen
EURASIP Journal on Audio, Speech, and Music Processing, Volume 2021, pp 1-19; doi:10.1186/s13636-021-00200-z

Estimating the direction-of-arrival (DOA) of multiple acoustic sources is one of the key technologies for humanoid robots and drones. However, it is a most challenging problem due to a number of factors, including the platform size which puts a constraint on the array aperture. To overcome this problem, a high-resolution DOA estimation algorithm based on sparse Bayesian learning is proposed in this paper. A group sparse prior based hierarchical Bayesian model is introduced to encourage spatial sparsity of acoustic sources. To obtain approximate posteriors of the hidden variables, a variational Bayesian approach is proposed. Moreover, to reduce the computational complexity, the space alternating approach is applied to push the variational Bayesian inference to the scalar level. Furthermore, an acoustic DOA estimator is proposed to jointly utilize the estimated source signals from all frequency bins. Compared to state-of-the-art approaches, the high-resolution performance of the proposed approach is demonstrated in experiments with both synthetic and real data. The experiments show that the proposed approach achieves lower root mean square error (RMSE), false alert (FA), and miss-detection (MD) than other methods. Therefore, the proposed approach can be applied to some applications such as humanoid robots and drones to improve the resolution performance for acoustic DOA estimation especially when the size of the array aperture is constrained by the platform, preventing the use of traditional methods to resolve multiple sources.
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