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ISSN / EISSN : 2639-5274 / 2639-5274
Total articles ≅ 398
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#### Latest articles in this journal

An-An Zhang, Xiyue Cheng, Xu He, Wei Liu, Shuiquan Deng, ,
Published: 21 October 2021
Research, Volume 2021, pp 1-11; https://doi.org/10.34133/2021/9874273

Abstract:
The poor electrical conductivity of metal-organic frameworks (MOFs) has been a stumbling block for its applications in many important fields. Therefore, exploring a simple and effective strategy to regulate the conductivity of MOFs is highly desired. Herein, anionic guest molecules are incorporated inside the pores of a cationic MOF (PFC-8), which increases its conductivity by five orders of magnitude while maintaining the original porosity. In contrast, the same operation in an isoreticular neutral framework (PFC-9) does not bring such a significant change. Theoretical studies reveal that the guest molecules, stabilized inside pores through electrostatic interaction, play the role of electron donors as do in semiconductors, bringing in an analogous n-type semiconductor mechanism for electron conduction. Therefore, we demonstrate that harnessing electrostatic interaction provides a new way to regulate the conductivity of MOFs without necessarily altering the original porous structure. This strategy would greatly broaden MOFs’ application potential in electronic and optoelectronic technologies.
Hemi Luan, , Jiufeng Li, Yanqiu Zhou, Jing Fang, Hongxiu Liu, Yuanyuan Li, Wei Xia, Shunqing Xu,
Published: 18 October 2021
Research, Volume 2021, pp 1-11; https://doi.org/10.34133/2021/9873135

Abstract:
Endocrine-disrupting chemicals (EDCs) are widespread environmental chemicals that are often considered as risk factors with weak activity on the hormone-dependent process of pregnancy. However, the adverse effects of EDCs in the body of pregnant women were underestimated. The interaction between dynamic concentration of EDCs and endogenous hormones (EHs) on gestational age and delivery time remains unclear. To define a temporal interaction between the EDCs and EHs during pregnancy, comprehensive, unbiased, and quantitative analyses of 33 EDCs and 14 EHs were performed for a longitudinal cohort with 2317 pregnant women. We developed a machine learning model with the dynamic concentration information of EDCs and EHs to predict gestational age with high accuracy in the longitudinal cohort of pregnant women. The optimal combination of EHs and EDCs can identify when labor occurs (time to delivery within two and four weeks, AUROC of 0.82). Our results revealed that the bisphenols and phthalates are more potent than partial EHs for gestational age or delivery time. This study represents the use of machine learning methods for quantitative analysis of pregnancy-related EDCs and EHs for understanding the EDCs’ mixture effect on pregnancy with potential clinical utilities.
Lihong Su, Zhou Yang, Xitong Wang, Ziao Zou, Bo Wang, Gary Hodes, Ninghui Chang, Yongyong Suo, Zhibo Ma, Haoxu Wang, et al.
Published: 13 October 2021
Research, Volume 2021, pp 1-8; https://doi.org/10.34133/2021/9802795

Abstract:
We report a novel Mn-Co-Ni-O (MCN) nanocomposite in which the p-type semiconductivity of Mn-Co-Ni-O can be manipulated by addition of graphene. With an increase of graphene content, the semiconductivity of the nanocomposite can be tuned from p-type through electrically neutral to n-type. The very low effective mass of electrons in graphene facilitates electron tunneling into the MCN, neutralizing holes in the MCN nanoparticles. XPS analysis shows that the multivalent manganese ions in the MCN nanoparticles are chemically reduced by the graphene electrons to lower-valent states. Unlike traditional semiconductor devices, electrons are excited from the filled graphite band into the empty band at the Dirac points from where they move freely in the graphene and tunnel into the MCN. The new composite film demonstrates inherent flexibility, high mobility, short carrier lifetime, and high carrier concentration. This work is useful not only in manufacturing flexible transistors, FETs, and thermosensitive and thermoelectric devices with unique properties but also in providing a new method for future development of 2D-based semiconductors.
Xuefen Song, Hao Yin, Qing Chang, YuChi Qian, Chongguang Lyu, Huihua Min, Xinrong Zong, Chao Liu, Yinyu Fang, Zhengchun Cheng, et al.
Published: 8 October 2021
Research, Volume 2021, pp 1-9; https://doi.org/10.34133/2021/9760729

Abstract:
Organic-inorganic hybrid perovskites (OIHPs) have proven to be promising active layers for nonvolatile memories because of their rich abundance in earth, mobile ions, and adjustable dimensions. However, there is a lack of investigation on controllable fabrication and storage properties of one-dimensional (1D) OIHPs. Here, the growth of 1D (NH=CINH3)3PbI5 ((IFA)3PbI5) perovskite and related resistive memory properties are reported. The solution-processed 1D (IFA)3PbI5 crystals are of well-defined monoclinic crystal phase and needle-like shape with the length of about 6 mm. They exhibit a wide bandgap of 3 eV and a high decomposition temperature of 206°C. Moreover, the (IFA)3PbI5 films with good uniformity and crystallization were obtained using a dual solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). To study the intrinsic electric properties of this anisotropic material, we constructed the simplest memory cell composed of only Au/(IFA)3PbI5/ITO, contributing to a high-compacted device with a crossbar array device configuration. The resistive random access memory (ReRAM) devices exhibit bipolar current-voltage (I-V) hysteresis characteristics, showing a record-low power consumption of ~0.2 mW among all OIHP-based memristors. Moreover, our devices own the lowest power consumption and “set” voltage (0.2 V) among the simplest perovskite-based memory devices (inorganic ones are also included), which are no need to require double metal electrodes or any additional insulating layer. They also demonstrate repeatable resistance switching behaviour and excellent retention time. We envision that 1D OIHPs can enrich the low-dimensional hybrid perovskite library and bring new functions to low-power information devices in the fields of memory and other electronics applications.
Zhandong Huang, Shengdong Zhao, Yiyuan Zhang, Zheren Cai, Zheng Li, Junfeng Xiao, Meng Su, , , Yaozong Pan, et al.
Published: 30 September 2021
Research, Volume 2021, pp 1-14; https://doi.org/10.34133/2021/9757943

Abstract:
Efficient acoustic communication across the water-air interface remains a great challenge owing to the extreme acoustic impedance mismatch. Few present acoustic metamaterials can be constructed on the free air-water interface for enhancing the acoustic transmission because of the interface instability. Previous strategies overcoming this difficulty were limited in practical usage, as well as the wide-angle and multifrequency acoustic transmission. Here, we report a simple and practical way to obtain the wide-angle and multifrequency water-air acoustic transmission with a tunable fluid-type acoustic metasurface (FAM). The FAM has a transmission enhancement of acoustic energy over 200 times, with a thickness less than the wavelength in water by three orders of magnitude. The FAM can work at an almost arbitrary water-to-air incident angle, and the operating frequencies can be flexibly adjusted. Multifrequency transmissions can be obtained with multilayer FAMs. In experiments, the FAM is demonstrated to be stable enough for practical applications and has the transmission enhancement of over 20 dB for wide frequencies. The transmission enhancement of music signal across the water-air interface was performed to demonstrate the applications in acoustic communications. The FAM will benefit various applications in hydroacoustics and oceanography.
, Mingzhao Wang, , Shaojie Wang, Yanzhao Wang, Chaohui Wang, Yixuan Zeng, Jiafang Li, Shuang Zhang, Wei Huang
Published: 10 September 2021
Research, Volume 2021, pp 1-11; https://doi.org/10.34133/2021/9806789

Abstract:
Many real-world applications, including adaptive radar scanning and smart stealth, require reconfigurable multifunctional devices to simultaneously manipulate multiple degrees of freedom of electromagnetic (EM) waves in an on-demand manner. Recently, kirigami technique, affording versatile and unconventional structural transformation, has been introduced to endow metamaterials with the capability of controlling EM waves in a reconfigurable manner. Here, we report for a kirigami-inspired sparse meta-architecture, with structural density of 1.5% in terms of the occupation space, for adaptive invisibility based on independent operations of frequency, bandwidth, and amplitude. Based on the general principle of dipolar management via structural reconstruction of kirigami-inspired meta-architectures, we demonstrate reconfigurable invisibility management with abundant EM functions and a wide tuning range using three enantiomers (A, B, and C) of different geometries characterized by the folding angle $β$. Our strategy circumvents issues of limited abilities, narrow tuning range, extreme condition, and high cost raised by available reconfigurable metamaterials, providing a new avenue toward multifunctional smart devices.
Qingsong Zhang, Yunlong Sun, Haijing Li, Kun Tang, , Dong Wang, , Yunqi Liu
Published: 3 September 2021
Research, Volume 2021, pp 1-8; https://doi.org/10.34133/2021/9790705

Abstract:
The synthesis of new C–C bonded two-dimensional (2D) covalent organic frameworks (COFs) is highly desirable. Here, a simple but effective synthetic strategy has been developed using an irreversible Brønsted acid-catalyzed aldol cyclotrimerization reaction by virtue of truxene as a linkage. Nonolefin C–C bonded 2D truxene-based covalent organic frameworks (Tru-COFs) were constructed by polymerization of 1,3,5-triindanonebenzene (TDB). The structure formation was confirmed by wide-angle X-ray scattering, Fourier-transform infrared spectroscopy, and solid-state 13C CP/MAS NMR. The results showed that the Tru-COFs were porous (645 m2/g) and chemically stable. Benzyl methylene in conjugated Tru-COFs more effectively produced photoinduced radicals than the model truxene compound. Due to the radical photoresponsiveness, Tru-COFs were efficient catalysts for photocatalytic oxidation of sulfides. We expect that this will provide a new synthetic methodology to obtain C–C bonded functional 2D COFs.
Yuanyuan Fan, Yingshun Zhou, Meng Lu, Haibin Si, Lu Li,
Published: 31 August 2021
Research, Volume 2021, pp 1-12; https://doi.org/10.34133/2021/9862876

Abstract:
Recently, combination immunotherapy, which incorporates the activation of the immune system and inhibition of immune escape, has been proved to be a new powerful strategy for more efficient tumor suppression compared to monotherapy. However, the major challenge is how to integrate multiple immune drugs together and efficiently convey these drugs to tumor sites. Although a variety of nanomaterials have been exploited as carriers for targeting tumor issues and the delivery of multiple drugs, their potential toxicity, immune rejection, and stability are still controversial for clinical application. Here, we proposed endogenic exosomes as drug carriers to deliver two antibodies acting as tumor-targeting molecules and block checkpoint inhibitors with specific response to the tumor microenvironment and costimulatory molecules for further improvement of therapeutic effect. The versatile exosomes exhibit excellent biocompatibility and provide a combination immunotherapy platform with synergistic advantages of activation of immune response and inhibition of immune escape.
Xiaolin Ge, Yubin He, Kaiyu Zhang, Xian Liang, Chengpeng Wei, Muhammad A. Shehzad, Wanjie Song, Zijuan Ge, Geng Li, Weisheng Yu, et al.
Published: 31 August 2021
Research, Volume 2021, pp 1-11; https://doi.org/10.34133/2021/9762709

Abstract:
Highly conductive anion-exchange membranes (AEMs) are desirable for applications in various energy storage and conversion technologies. However, conventional AEMs with bulky HCO3 - or Br- as counterion generally exhibit low conductivity because the covalent bonding restrains the tethered cationic group’s mobility and rotation. Here, we report an alternative polyrotaxane AEM with nontethered and free-shuttling phosphonium cation. As proved by temperature-dependent NMR, solid-state NMR, and molecular dynamics simulation, the phosphonium cation possesses a thermally trigged shuttling behavior, broader extension range, and greater mobility, thus accelerating the diffusion conduction of bulky anions. Owing to this striking feature, high HCO3 - conductivity of 105 mS cm-1 at 90°C was obtained at a relatively lower ion-exchange capacity of 1.17 mmol g-1. This study provides a new concept for developing highly conductive anion-exchange membranes and will catalyze the exploration of new applications for polyrotaxanes in ion conduction processes.
Tianjia Yang, Yunzhong Wang, Jixuan Duan, Shuangyu Wei, Saixing Tang,
Published: 27 August 2021
Research, Volume 2021, pp 1-11; https://doi.org/10.34133/2021/9757460

Abstract:
Pure organic luminogens with long-persistent luminescence have been extensively studied, on account of their fundamental research significance and diverse utilizations in anticounterfeiting, bioimaging, encryption, organic light-emitting diodes, chemo-sensing, etc. However, time-dependent color-tunable afterglow is rarely reported, especially for single-component materials. In this work, we reported an organic luminogen with time-dependent afterglow, namely, benzoyleneurea (BEU), with multiple persistent room-temperature phosphorescence (p-RTP) and thermally activated delayed fluorescence (TADF) in single crystals. While the lifetime of TADF is relatively short (~1.2 ms), those for p-RTP are as long as around 369~754 ms. The comparable but different decay rates of diversified p-RTP emissions endow BEU crystals with obvious time-dependent afterglow. The existence of multiple emissions can be reasonably illustrated by the clustering-triggered emission (CTE) mechanism. Single-crystal structure illustrates that the combination of benzene ring and nonconventional chromophores of ureide helps facilitate divergent intermolecular interactions, which contribute to the formation of varying emissive species. Moreover, its methyl- and chloro-substituted derivatives show similar multiple p-RTP emissions. However, no time-dependent afterglows are observed in their crystals, due to the highly approaching lifetimes. The afterglow color variation of BEU crystals grants its applications in advanced anticounterfeiting field and information encryption.