bluuebunny/crossref_metadata_2025 huggingface dataset:
Lead‐Free Perovskite Photodetectors: Progress, Challenges, and Opportunities
Authors: Zhang Yiqi , Ma Yao , Wang Yaxi , Zhang Xindong , Zuo Chuantian , Shen Liang , Ding Liming
Published: May 2021

State‐of‐the‐art photodetectors which apply hybrid perovskite materials have emerged as powerful candidates for next‐generation light sensing. Among them, lead‐based ones are the most popular beyond doubt on account of their unique and superior optoelectronic properties. Nevertheless, trade‐off toward commercialization exists between nontoxicity and high performance, with the poor stability of lead‐based perovskites, indicating that it is indispensable to substitute lead with nontoxic element meanwhile bringing about a comparable figure of merit of photodetectors and relatively long‐term stability. Herein, recent advances in lead‐free perovskite photodetectors are reviewed, analyzing the principle while designing new materials and highlighting some remarkable progress, which are comparable, even superior, to lead‐based photodetectors. Furthermore, their potential strategy in optical communication, image sensing, narrowband photodetection, etc., is examined and a perspective on developing new materials and photodetectors with superior properties for more practical applications is provided.
Abrasion Resistant/Waterproof Stretchable Triboelectric Yarns Based on Fermat Spirals
Authors: Zhang Dewei , Yang Weifeng , Gong Wei , Ma Wanwan , Hou Chengyi , Li Yaogang , Zhang Qinghong , Wang Hongzhi
Published: May 2021

Emerging energy harvesting yarns, via triboelectric effects, have wide application prospects in new‐generation wearable electronics. However, few studies have been carried out regarding simultaneously achieving high electrical performance, mechanical robustness, and comfortability in industrial‐scalable yarn. Here, an electronic yarn twisted into Fermat spiral, which has outstanding dynamic structure stability, is reported. The Fermat‐spiral‐based energy yarns (FSBEY) can simultaneously realize ultrahigh abrasion resistance (over 5000 Martindale standard abrasion cycles), stable reversible strain (100%), and excellent electrical output. Considerably high output (105 V, ≈1.2 µA under 2 Hz) can be attained upon contacting a single yarn (30 cm) with latex material, which is superior to most state‐of‐the‐art stretchable triboelectric yarns. The application of these FSBEY in wireless gesture recognition, smart screen information protection, and harvesting of energy from water dropletsis demonstrated. Moreover, textiles knitted from the FSBEY have distinguished waterproof nature and are breathable. This work shows a feasible proposal for building future “energy garments”.
Electron‐Selective ‍Lithium Contacts for Crystalline Silicon Solar Cells
Authors: Kang Jingxuan , Yang Xinbo , Liu Wenzhu , Liu Jiang , Xu Hang , Allen Thomas , De Wolf Stefaan
Published: May 2021

Separating photogenerated charge carriers by carrier‐selective heterostructure contacts rather than by doped homojunctions is a promising pathway to approach the theoretical power conversion efficiency (PCE) limit of crystalline silicon (c‐Si) solar cells. An electron‐selective, hole‐blocking lithium contact for c‐Si solar cells is presented by simple thermal evaporation of air‐stable Li3N powder. It is found that this lithium contact introduces only a minimal Schottky‐barrier height for electron transport at its interface with lightly doped n‐type c‐Si surfaces, resulting in a low contact resistivity of 12.8 mΩ cm2. By implementing a full‐area electron‐selective lithium contact, an n‐type c‐Si solar cell with a PCE of 19% is achieved, representing a 4% absolute PCE improvement over reference devices with an aluminum contact. The choices of electron‐selective contact materials for photovoltaic devices, using simple, scalable fabrication methods are extended.
Ultrasensitive Dual‐Mode Humidity Detection Using a Plasmonic‐Photonic Hybrid Waveguide
Authors: Shen Yang , Wang Guanchu , Zou Qiushun , She Xiaoyi , Cai Da , Jin Chongjun
Published: May 2021

Reliable and ultrasensitive humidity detection is essential in industrial process controls, meteorology, and medical diagnostics. In this study, a high‐performance relative humidity (RH) sensor driven by a plasmonic‐photonic hybrid system (PPHS), which supports waveguide modes and surface plasmon polariton mode simultaneously, is proposed. Due to the distinct sensitivities of these two modes to refractive index variation and volume expansion, the dual‐mode RH detection platform offers a unique tool for isolating the individual contribution of each effect and further revealing the mechanism of moisture absorption in a crosslinked PVA film. As an RH sensor, PPHS delivers a wavelength sensitivity of 1.16 nm %RH−1 (40–70 %RH) and an intensity sensitivity of 1.1 dB %RH−1 (55–90 %RH), respectively. Benefited from such an ultrahigh sensitivity, together with excellent recyclability and a quick response time of a few seconds, the PPHS shows an almost identical real‐time RH curve with an even higher resolution (<0.1 %RH) compared to a commercial electrical hygrometer in the practical ambient RH monitoring. The PPHS is further demonstrated as a human breathing sensor and a skin‐humidity‐based noncontact switch, suggesting that the PPHS provides a great potential in medical diagnostics and optical modulation.
Augmented All‐Optical Active Terahertz Device Using Graphene‐Based Metasurface
Authors: Choi Geunchang , Chau Tuan Khanh , Hong Sung Ju , Kim Dasom , Kim Sung Hyuk , Kim Dai‐Sik , Suh Dongseok , Bahk Young‐Mi , Jeong Mun Seok
Published: May 2021

Photo‐excited graphene has a positive (semiconductor‐like) or negative (metal‐like) response depending on the Fermi level, which is tuned by gate control, doping, and growth. Both negative and positive photoconductive responses have a potential application as an ultrafast optical modulator in the control of light transmission. However, it is challenging to achieve a high on/off ratio in the photo‐excited graphene because of a small absorption of electromagnetic waves and a limitation of photo‐induced conductivity change. Here, the negative‐type high on/off ratio and ultrafast terahertz modulation are experimentally demonstrated using graphene/metal nanoslot antennas. When the graphene covers the nanoslot antennas, the terahertz waves are completely blocked (off‐state). This perfect extinction results from the enhanced intraband absorption in graphene by strong localized fields near the nanogap. However, once the optical pump is applied to the graphene/nanoslot antennas, terahertz transmission becomes recovered resonantly (on‐state) due to the photo‐induced transparency of graphene that leads to a distinctive modulation from off‐ to on‐resonance. Furthermore, the fast carrier relaxation induced by strong terahertz field‐driven carrier redistribution is responsible for the faster modulation of transient terahertz transmission. The results will open up pathways toward negative‐response terahertz modulation applications with high on/off ratio and ultrafast time scale.
Fully Organic Bulk Polymer with Metallic Thermal Conductivity and Tunable Thermal Pathways
Authors: Zhang Yongzheng , Lei Chuxin , Wu Kai , Fu Qiang
Published: May 2021

Electrically insulating polymers are indispensable for electronic and energy applications, but their poor thermal conduction has increasingly become a bottleneck for high‐performance devices. Highly drawn low‐dimensional polymeric fibers and thin films can exhibit metallic conductivity. Extending this to bulk materials required by real world applications is prohibitive due to the additional interfacial thermal conduction barriers. It is demonstrated that highly aligned ultrahigh molecular weight polyethylene microfibers can be incorporated into a silicone matrix to yield a fully organic bulk polymer composite with a continuous vertical phonon pathway. This leads to a perpendicular thermal conductivity of 38.27 W m−1 K−1, at par with metals and two orders of magnitude higher than other bulk organic polymers. Taking further advantage of the mechanical flexibility of the microfibers, the processing method offers the freedom to tailor heat transfer pathways in a macroscopic 3D space. The material/process opens up opportunities for efficient thermal management in high‐performance devices.
Interlayer Modification of Pseudocapacitive Vanadium Oxide and Zn(H2O)n2+ Migration Regulation for Ultrahigh Rate and Durable Aqueous Zinc‐Ion Batteries
Authors: Chen Hangda , Huang Juanjuan , Tian Shuhao , Liu Li , Qin Tianfeng , Song Lei , Liu Yanpeng , Zhang Yanan , Wu Xiaogang , Lei Shulai , Peng Shanglong
Published: May 2021

The interlayer modification and the intercalation pseudocapacitance have been combined in vanadium oxide electrode for aqueous zinc‐ion batteries. Intercalation pseudocapacitive hydrated vanadium oxide Mn1.4V10O24·12H2O with defective crystal structure, interlayer water, and large interlayer distance has been prepared by a spontaneous chemical synthesis method. The inserted Mn2+ forms coordination bonds with the oxygen of the host material and strengthens the interaction between the layers, preventing damage to the structure. Combined with the experimental data and DFT calculation, it is found that Mn2+ refines the structure stability, adjusts the electronic structure, and improves the conductivity of hydrated vanadium oxide. Also, Mn2+ changes the migration path of Zn2+, reduces the migration barrier, and improves the rate performance. Therefore, Mn2+‐inserted hydrated vanadium oxide electrode delivers a high specific capacity of 456 mAh g−1 at 0.2 A g–1, 173 mAh g–1 at 40 A g–1, and a capacity retention of 80% over 5000 cycles at 10 A g–1. Furthermore, based on the calculated zinc ion mobility coefficient and Zn(H2O)n2+ diffusion energy barrier, the possible migration behavior of Zn(H2O)n2+ in vanadium oxide electrode has also been speculated, which will provide a new reference for understanding the migration behavior of hydrated zinc‐ion.
Enhanced Delivery of Neuroactive Drugs via Nasal Delivery with a Self‐Healing Supramolecular Gel
Authors: Wang Julie Tzu‐Wen , Rodrigo Ana C. , Patterson Anna K. , Hawkins Kirsten , Aly Mazen M. S. , Sun Jia , Al Jamal Khuloud T. , Smith David K.
Published: May 2021

This paper reports the use of a self‐assembling hydrogel as a delivery vehicle for the Parkinson's disease drug l‐DOPA. Based on a two‐component combination of an l‐glutamine amide derivative and benzaldehyde, this gel has very soft rheological properties and self‐healing characteristics. It is demonstrated that the gel can be formulated to encapsulate l‐DOPA. These drug‐loaded gels are characterized, and rapid release of the drug is obtained from the gel network. This drug‐loaded hydrogel has appropriate rheological characteristics to be amenable for injection. This system is therefore tested as a vehicle for nasal delivery of neurologically‐active drugs—a drug delivery strategy that can potentially avoid first pass liver metabolism and bypass the blood–brain barrier, hence enhancing brain uptake. In vitro tests indicate that the gel has biocompatibility with respect to nasal epithelial cells. Furthermore, animal studies demonstrate that the nasal delivery of a gel loaded with 3H‐labeled l‐DOPA out‐performed a simple intranasal l‐DOPA solution. This is attributed to longer residence times of the gel in the nasal cavity resulting in increased blood and brain concentrations. It is demonstrated that the likely routes of brain penetration of intranasally‐delivered l‐DOPA gel involve the trigeminal and olfactory nerves connecting to other brain regions.
Rich Surface Oxygen Vacancies of MnO2 for Enhancing Electrocatalytic Oxygen Reduction and Oxygen Evolution Reactions
Authors: Zhuang Qian , Ma Na , Yin Zhaohui , Yang Xue , Yin Zhen , Gao Jian , Xu Yao , Gao Zirui , Wang Hong , Kang Jianli , Xiao Dequan , Li Jianxin , Li Xifei , Ma Ding
Published: May 2021

Development of catalysts for the electrochemical oxygen reactions, namely, oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), is critical for the application of various renewable energy technologies. The aim of this work is to prepare low‐cost MnO2 electrocatalyst with high activity for the ORR and OER via introduction of surface oxygen vacancies (OVs). Herein, the procedure of thermal heating treatment under air or H2 has been demonstrated as an efficient way to create OVs on the surface of α‐MnO2 and β‐MnO2 nanorods, which are found to be highly active for both ORR and OER. The existence of surface OVs can modulate the intrinsic activity of α‐MnO2 and β‐MnO2 and improve their ORR and OER kinetics. More importantly, the H2‐treated MnO2 possesses much more surface OVs and thus exhibits much better catalytic performances for ORR and OER in comparison with MnO2 obtained by common annealing treatments under air. Especially, the H2‐treated α‐MnO2 nanorods show the best activity for the ORR and OER. The results confirm that the heating treatment under H2 reducing atmosphere can be a facile and efficient process to develop bifunctional Mn‐based electrocatalysts for electrochemical oxygen reactions.
Liposomes with Water as a pH‐Responsive Functionality for Targeting of Acidic Tumor and Infection Sites
Authors: Wang Da‐Yuan , Yang Guang , van der Mei Henny C. , Ren Yijin , Busscher Henk J. , Shi Linqi
Published: May 2021

A lipid named DCPA was synthesized under microwave‐assisted heating. DCPA possesses a pyridine betaine, hydrophilic group that can be complexed with water through hydrogen bonding (DCPA‐H2O). DCPA‐H2O liposomes became protonated relatively fast already at pH<6.8, due to the high HOMO binding energy of DCPA‐H2O. In murine models, DCPA‐H2O liposomes had longer blood circulation times than natural DPPC or cationic DCPM liposomes, while after tail‐vein injection DCPA‐H2O liposomes targeted faster to solid tumors and intra‐abdominal infectious biofilms. Therapeutic efficacy in a murine, infected wound‐healing model of tail‐vein injected ciprofloxacin‐loaded DCPA‐H2O liposomes exceeded the ones of clinically applied ciprofloxacin as well as of ciprofloxacin‐loaded DPPC or DCPM liposomes.
Age and sex‐specific reference intervals for prooxidant‐antioxidant balance, anti‐heat‐shock protein 27 (anti‐hsp27), and routine laboratory tests in the middle‐aged adult population
Authors: Ghazizadeh Hamideh , Bohn Mary Kathryn , Yaghooti‐Khorasani Mahdiyeh , Ghaffarian‐Zirak Roshanak , Valizadeh Mohsen , Saberi‐Karimian Maryam , Safarian Hamideh , Kamel‐Khodabandeh Atieh , Zare‐Feyzabadi Reza , Timar Ameneh , Mohammadi‐Bajgiran Maryam , Oladi Mohammad Reza , Gachpazan Meysam , Rohban Mohadeseh , Esmaily Habibollah , Ferns Gordon A. , Adeli Khosrow , Ghayour‐Mobarhan Majid
Published: May 2021

Introduction

We aimed to define specific reference intervals (RIs) for 11 biomarkers including inflammatory and oxidative stress biomarkers, liver, and renal function tests in a healthy Iranian adult population for the first time.

Methods

CLSI Ep28‐A3 guidelines were then used to calculate accurate age‐ and sex‐ as well as body mass index (BMI)‐specific RIs.

Results

RIs for studied biomarkers showed no significant age and sex‐specific differences, except for uric acid, which had higher concentrations in men when compared to women. Additionally, after partitioning the participants based on the BMI with a cutoff point of 25 kg/m2, only the levels of hs‐CRP were positively associated with higher BMI (RI for BMI>25: 0.51–7.85 mg/L and for BMI<25: 0.40–4.46 mg/L). RI for PAB and anti‐hsp‐27 were reported 4.69–155.36 HK and 0.01–0.70 OD in men and women aged 35–65 years old.

Conclusion

Partitioning by sex and BMI was only required for uric acid and hs‐CRP, respectively, while other biomarkers required no partitioning. These results can be expected to valuably contribute to improve laboratory test result interpretation in adults for improved monitoring of various diseases in the Iranian population.
Simultaneous confidence tubes for comparing several multivariate linear regression models
Authors: Peng Jianan , Liu Wei , Bretz Frank , Hayter A. J.
Published: May 2021

Much of the research on multiple comparison and simultaneous inference in the past 60 years or so has been for the comparisons of several population means. Spurrier seems to have been the first to investigate multiple comparisons of several simple linear regression lines using simultaneous confidence bands. In this paper, we extend the work of Liu et al. for finite comparisons of several univariate linear regression models using simultaneous confidence bands to finite comparisons of several multivariate linear regression models using simultaneous confidence tubes. We show how simultaneous confidence tubes can be constructed to allow more informative inferences for the comparison of several multivariate linear regression models than the current approach of hypotheses testing. The methods are illustrated with examples.
I cannot do that…I'm a counsellor: Implications of professional boundaries on counsellors' public life as entertainers
Authors: Decelis Karen , Falzon Ruth
Published: May 2021

Background

This study explores perceptions regarding counsellors who are also public entertainers, an issue on which there is a dearth in literature and in codes of ethics. For this study, we reviewed three codes of ethics: the 2014 American Counselling Association's (ACA), the 2017 British Association for Counselling and Psychotherapy's (BACP) and the 2011 Malta Association for the Counselling Profession's (MACP).

Method

The research question begged a qualitative approach using individual, audio‐recorded, semi‐structured interviews with twelve participants: six counsellors and six non‐counsellors. Thematic analysis was selected as the most appropriate methods for analysis.

Findings

Participants think that counsellors can be entertainers during their free time, but need strict boundaries and ethical responsibility whilst following Rogers' (1957, 1980) person‐centred skills of being non‐judgemental, empathic and congruent. Boundaries, the context of a small‐island community, public life, self‐disclosure, wellbeing and challenges were all major themes elicited. Counsellor participants (CPs) highlighted that there is no guide Maltese counsellors can follow regarding what they can and cannot do in public as public entertainers. Participants noted that in the local context, counsellors need to be careful about disclosing their opinions regarding Politics and political affiliations. Politics seemed to be of particular concern and reflects the local biparty culture often loaded with emotions and very strong opinion and allegiances. Participants also reflected that the status of an entertainer/counsellor can also help publicise the profession in the best interest of wellbeing and the profession.

Implications for Practice

Implications for practice include training courses with opportunities for reflection on what counsellors can/not do in public in order to continuously address boundaries; training on social media behaviour; training on specialised ethical issues around being a counsellor/entertainer through continuing professional development sessions; specialised training for supervisors; issues to be address in contacts with clients; and updated codes of ethics/ethical framworks.

Conclusion

Recommendations include personal reflection and supervision, training at master's level, continued professional development, revised codes of ethics and ethical guidance by qualified supervisors. This study was a master's dissertation submission, where Karen was the supervisee and Ruth the supervisor.
Secondary sclerosing cholangitis as a complication of severe COVID‐19: A case report and review of the literature
Authors: Klindt Caroline , Jensen Björn‐Erik , Brandenburger Timo , Feldt Torsten , Killer Alexander , Schimmöller Lars , Antoch Gerald , Senff Tina , Hauka Sandra , Timm Jörg , Bahners Bahne Hendrik , Seidl Maximilian , Esposito Irene , Luedde Tom , Bode Johannes G. , Keitel Verena
Published: May 2021

This case of secondary sclerosing cholangitis (SSC‐CIP) emphasizes the need to provide follow‐up care for patients that have recovered from COVID‐19 in order to understand the complexity of SARS‐CoV‐2 associated sequela.
Asymmetric 1,4‐Addition Reactions Catalyzed by N‐Terminal Thiourea‐Modified Helical l‐Leu Peptide with Cyclic Amino Acids
Authors: Sato Kazuki , Umeno Tomohiro , Ueda Atsushi , Kato Takuma , Doi Mitsunobu , Tanaka Masakazu
Published: May 2021

N‐terminal thiourea‐modified l‐Leu‐based peptide {(3,5‐diCF3Ph)NHC(=S)‐(l‐Leu‐l‐Leu‐Ac5c)2‐OMe} with five‐membered ring α,α‐disubstituted α‐amino acids (Ac5c) catalyzed a highly enantioselective 1,4‐addition reaction between β‐nitrostyrene and dimethyl malonate. The enantioselective reaction required only 0.5 mol % chiral peptide‐catalyst in the presence of iPr2EtN (2.5 equiv.), and gave a 1,4‐adduct with 93 % ee of an 85 % yield. As Michael acceptors, various β‐nitrostyrene derivatives such as methyl, p‐fluoro, p‐bromo, and p‐methoxy substituents on the phenyl group, 2‐furyl, 2‐thiophenyl, and naphthyl β‐nitroethylenes could be applied. Furthermore, various alkyl malonates and cyclic β‐keto‐esters could be used as Michael donors. It became clear that the length of the peptide chain, a right‐handed helical structure, amide N−Hs, and the N‐terminal thiourea moiety play crucial roles in asymmetric induction.
Indium‐Catalyzed C‐F Bond Transformation through Oxymetalation/β‐Fluorine Elimination to Access Fluorinated Isocoumarins
Authors: Yata Tetsuji , Nishimoto Yoshihiro , Chiba Kouji , Yasuda Makoto
Published: May 2021

Invited for the cover of this issue are Yoshihiro Nishimoto, Makoto Yasuda and co‐workers at Osaka University and MOLSIS Inc.. The image depicts the crafting of a gladiator's shield to represent the reaction reported in this work. Read the full text of the article at 10.1002/chem.202100672.
PROTOCOL: Video‐based interventions for promoting positive social behaviour in children with autism spectrum disorders: a systematic review and meta‐analysis
Authors: Keenan Ciara , Thurston Allen , Storey Catherine , Urbanska Karolina
Published: May 2021

This is the protocol for a Campbell review. The primary objective for this review is summarising the effectiveness of video‐based interventions (VBI) in promoting prosocial behaviours in a population of young people with autism spectrum disorders (ASD). The research questions employed to fulfil this objective include: (1) Do VBI improve prosocial behaviours in children with ASD? (2) Which social skills and interactive behaviours are most successful? (3) Do VBI generally have successful rates of skill generalisation and response maintenance? (4) Do demographic characteristics (age, gender) of participants influence the effectiveness of VBI's?
A novel scheme for mitigation of energy hole problem in wireless sensor network for military application
Authors: Behera Trupti Mayee , Mohapatra Sushanta Kumar
Published: May 2021

Wireless Sensor Networks (WSNs) have been widely considered as one of the most important technologies with unique characteristics designed for various applications. However, one of the major problems in WSNs is a limited lifetime. The creation of an energy hole near the sink has been a chief concern for researchers working to mitigate the lifetime problem. The data transmission in a multi‐hop network, as used for military purposes, follows a many‐to‐one pattern resulting in a heavier traffic load for nodes near to sink. Hence, these nodes deplete energy very soon resulting in a vacuum of energy and breakage of the network. This article aims to mitigate the energy hole problem (EHP) by implementing a corona‐based model in a clustered network. Here the cluster head selection is regularized by preferring the outer corona nodes over the inner ones. As a result, the energy balances evenly in the network with fewer loads to the nodes nearer to the sink. The distance between the sending node and the sink is evaluated to estimate the required energy for transmission. Only when a node has energy more than the required value, it is allowed to transmit, or else it turns off the radio to save energy. The proposed model is implemented in both homogeneous and heterogeneous networks and better network performance is observed.
The mechanism and function of super enhancer RNA
Authors: Xiao Shibai , Huang Qin , Ren Hao , Yang Min
Published: May 2021

Super enhancer (SE) is a cluster of enhancers that has a stronger ability to promote transcription compared to the typical enhancer (TE). Similar to TE, which can transcribe enhancer RNA (eRNA), SE produces super enhancer RNA (seRNA). The activation of SE is cell and tissue‐specific, and the SE‐associated genes are mostly linked to the cell fate. This is demonstrated by the important role‐played by SE in the embryonic stem cell (ESC) and multiple cancer development. SeRNA regulates transcription in both cis and trans configuration, and those located in the cytoplasm mediates various cell activities. However, the functions of seRNAs are unclear, and most of them have a synergistic effect with SE and SE‐associated genes. In this mini review, we summarized the mechanisms of seRNA and functions of both SE and seRNA.
Drivers of leafcutter ant populations and their inter‐trophic relationships in Amazonian forest islands
Authors: Palmeirim Ana Filipa , Benchimol Maíra , Leal Inara R. , Peres Carlos A.
Published: May 2021

Under habitat loss and fragmentation, the intensity of local ecological processes involving species interactions changes pervasively, accelerating local species extinctions, and disrupting essential ecosystem functions. We addressed this issue by examining the direct population drivers of apex predators (five felid species), armadillo mesopredators, leafcutter ants (Atta sexdens and Atta cephalotes), and the indirect effects mediated by their inter‐trophic relationships in a ~25‐yr‐old land‐bridge island system formed by a hydroelectric dam in the Central Amazon. These trophic groups and pioneer tree abundance were surveyed across 34 variable‐sized islands and three continuous forest sites. Leafcutter populations were characterized in relation to their occurrence, colony density, and proportion of inactive colonies, and for each leafcutter response, we considered the direct and/or indirect effects of forest area on each trophic group. Leafcutter occupancy was best explained by the direct model, colony density by either the direct or the indirect model, and proportion of inactive colonies by an indirect model via the effects of pioneer tree abundance. The direct forest area effects were positive for apex predators and leafcutter occupancy, but negative for armadillos and pioneer trees. Yet leafcutter colony density declined in increasingly larger forest areas. The absence or low abundance of apex predators on small islands released armadillo hyper‐abundance, which contrary to expectation from top‐down control, covaried positively with leafcutter colony density. Finally, the indirect model showed that leafcutter colonies were more active under higher pioneer tree abundances. That leafcutter density increases on smaller islands whenever present is likely attributed to the hyper‐abundance of pioneer plants and canopy gaps. Although apex predators apparently suppressed armadillos, the remaining fraction of the food web seems to be controlled by bottom‐up mechanisms most likely related the overall low foliage palatability typical of wet evergreen forests. Our findings can be used to inform the long‐term viability of forest ecosystems affected by hydropower development in lowland Amazonia.
Unstable intraguild predation causes establishment failure of a globally invasive species
Authors: Tuckett Quenton M. , Deacon Amy E. , Fraser Douglas , Lyons Timothy J. , Lawson Katelyn␣M. , Hill Jeffrey E.
Published: May 2021

Biotic resistance is often posited, but rarely known, to be the cause of invasion failure. Competition and predation are the most frequently identified processes that may prevent or limit the establishment of nonnative species. Interactions between nonnative and native species that involve intraguild predation (IGP) are very common in nature, although theory predicts most IGP systems should be unstable and lead to extinction. If this prediction is true, the frequency of invasion failures due to IGP may be underappreciated because of their fleeting nature and, thus, studies of unstable IGP systems are lacking, despite the opportunities they offer for understanding the factors affecting their unstable dynamics. We investigated a failed invasion involving an IGP relationship. In Florida, the guppy (Poecilia reticulata), a worldwide invader, fails to establish in the presence of eastern mosquitofish (Gambusia holbrooki). We tested whether and how resident mosquitofish cause guppy invasion failure using replicated mesocosm and aquarium trials. Both the predator and competitor components of the IGP relationship were strongly asymmetrical, with large impacts on guppies. We identified two effects, direct consumption of neonates and aggressive interference competition, that limited survival and recruitment. The highly unstable nature of this IGP relationship is the primary cause of the failure of the guppy to establish in Florida. Our study shows that the transient nature of an ephemeral IGP relationship can yield important insights into the underlying causes of invasion failure, including the role of strong biotic resistance.
Significant performance enhancement of all‐inorganic CsPbBr3 perovskite solar cells enabled by Nb‐doped SnO2 as effective electron transport layer
Authors: Guo Ruxin , Zhao Yan , Zhang Yongshang , Deng Quanrong , Shen Yonglong , Zhang Wei , Shao Guosheng
Published: May 2021

All‐inorganic CsPbBr3‐based perovskite solar cells (PSCs) have attracted great attention because of their high chemical and thermal stabilities in ambient air. However, the short‐circuit current density (Jsc) of CsPbBr3‐based PSCs is inadequate under solar illumination because of the wide bandgap, inefficient charge extraction and recombination loss, leading to lower power‐conversion efficiencies (PCEs). It is envisaged that in addition to narrowing the bandgap by alloying, Jsc of the PSCs could be enhanced by effective improvement of electron transportation, suppression of charge recombination at the interface between the perovskite and electron transporting layer (ETL), and tuning of the space charge field in the device. In this work, Nb‐doped SnO2 films as ETLs in the CsPbBr3‐based PSCs have been deposited at room temperature by high target utilization sputtering (HiTUS). Through optimizing the Nb doping level alone, the Jsc was increased by nearly 19%, from 7.51 to 8.92 mA·cm−2 and the PCE was enhanced by 27% from 6.73% to 8.54%. The overall benefit by replacing the spin‐coated SnO2 with sputtered SnO2 with Nb doping was up to 39% increase in Jsc and 62% increase in PCE. Moreover, the PCE of the optimized device showed negligible degradation over exposure to ambient environment (T ˜ 25 °C, RH˜45%), with 95.4% of the original PCE being maintained after storing the device for 1200 h.
Synthesis of Trinuclear Benzimidazole‐Fused Hybrid Scaffolds by Transition Metal‐Free Tandem C(sp2)−N Bond Formation under Microwave Irradiation
Authors: Dao Pham Duy Quang , Cho Chan Sik
Published: May 2021

2‐(2‐Bromoaryl)‐ and 2‐(2‐bromovinyl)benzimidazoles have been coupled and cyclized with 2‐methoxy‐ and 2‐aryloxybenzimidazoles as building blocks in the presence of a base under microwave irradiation to give a class of trinuclear N‐fused hybrid scaffolds, benzo[4,5]imidazo[1,2‐a]benzo[4,5]imidazo[1,2‐c]quinazolines and ‐pyrimidines, respectively, in good yields. 2‐(2‐Bromoaryl)‐ and 2‐(2‐bromovinyl)imidazoles also reacted with 2‐methoxybenzimidazoles in the presence of base under microwave irradiation to give a class of trinuclear N‐fused hybrid scaffolds, benzo[4,5]imidazo[1,2‐a]imidazo[1,2‐c]quinazolines and ‐pyrimidines, respectively, in similar yields. This process seems to proceed via an initial C(sp2)‐N coupling by an addition‐elimination nucleophilic aromatic substitution (SNAr) and subsequent cyclization accompanied by extrusion of alcohols.
Hydrolytic enzymes and their directly and indirectly effects on gluten and dough properties: An extensive review
Authors: Pourmohammadi Kiana , Abedi Elahe
Published: May 2021

Poor water solubility, emulsifying, and foaming properties of gluten protein have limited its applications. Gluten is structured by covalent (disulfide bonds) and noncovalent bonds (hydrogen bonds, ionic bonds, hydrophobic bonds) which prone to alteration by various treatments. Enzyme modification has the ability to alter certain properties of gluten and compensate the deficiencies in gluten network. By hydrolyzing mechanisms and softening effects, hydrolytic enzymes affect gluten directly and indirectly and improve dough quality. The present review investigates the effects of some hydrolytic enzymes (protease and peptidase, alcalase, xylanase, pentosanase, and cellulase) on the rheological, functional, conformational, and nutritional features of gluten and dough. Overall, protease, peptidase, and alcalase directly affect peptide bonds in gluten. In contrast, arabinoxylan, pentosan, and cellulose are affected, respectively, by xylanase, pentosanase, and cellulase which indirectly affect gluten proteins. The changes in gluten structure by enzyme treatment allow gluten for being used in variety of purposes in the food and nonfood industry.
Energy analysis of non‐Newtonian nanofluid flow over parabola of revolution on the horizontal surface with catalytic chemical reaction
Authors: Zeeshan Ahmed , Awais Muhammad , Alzahrani Faris , Shehzad Nasir
Published: May 2021

Nanofluids are special functional fluids, which are designed to reduce the loss of energy and maximize the transport of heat. The thermophoresis and Brownian motion of the particle are important factors in the transport of heat in these fluids. The rise in heat transport shows encouraging effects in control of dissipation of energy and reduces entropy generation. In the current study, two‐dimensional non‐Newtonian Casson nanofluid flow on an upper horizontal surface of a parabola is investigated. The impact of catalytic surface chemical reactions has been account also due to its industrial importance. For this flow problem, the governing equations are modeled using the law of conservation of mass, momentum, heat, and concentration equation. The fitting transformations are taken to change governing couple partial differential equations and domain into local similar ordinary differential equation and domain of [0,∞). Using the "RK4" approach with Newton's shooting schemes via MATLAB tools, the numerical solution of dimensionless governing equations is sorted. It is observed that the Casson fluid parameter caused a drop in temperature profile, and the chemical reaction parameter is the source of the rise in the temperature field.
Heat transfer analysis of magnetohydrodynamic Casson fluid through a porous medium with constant proportional Caputo derivative
Authors: Aleem Maryam , Asjad Muhammad Imran , Akgül Ali
Published: May 2021

This article aims to investigate free convection of a Casson fluid past a vertical plate embedded in porous medium with invariant wall temperature. It is assumed that the fluid can conduct electricity and it is flowing across a porous medium. The partial differential equations governing the model are made dimensionless by using dimensionless parameters. The Laplace transform method is applied to get analytical results. Furthermore, the hybrid fractional model is developed and the exact solutions for momentum and energy equations are acquired. The obtained results are compared with classical ones and the effect of hybrid fractional parameters are analyzed graphically by using MathCad software. Skin friction and heat transfer rate is analyzed for small and large times and for hybrid fractional parameter . We also have seen the increasing velocity profiles for buoyancy parameter Gr, whereas temperature of the fluid decreases for Pr. The rate of heat transfer and skin friction can be minimized by increasing the values of . Furthermore, the constant proportional Caputo derivative model exhibits more decay in velocity in comparison with classical model given in Khalid et al. Therefore, the constant proportional Caputo differential model demonstrates better memory function than the classical one. Moreover, the obtained results are identical to already published results of Khalid et al. and Imran et al.
Collagen‐based biomaterials for biomedical applications
Authors: Rezvani Ghomi Erfan , Nourbakhsh Nooshin , Akbari Kenari Mahsa , Zare Mina , Ramakrishna Seeram
Published: May 2021

Collagen is an insoluble fibrous protein that composes the extracellular matrix in animals. Although collagen has been used as a biomaterial since 1881, the properties and the complex structure of collagen are still extensive study subjects worldwide. In this article, several topics of importance for understanding collagen research are reviewed starting from its historical milestones, followed by the description of the collagen superfamily and its complex structures, with a focus on type I collagen. Subsequently, some of the superior properties of collagen‐based biomaterials, such as biocompatibility, biodegradability, mechanical properties, and cell activities, are pinpointed. These properties make collagen applicable in biomedicine, such as wound healing, tissue engineering, surface coating of medical devices, and skin supplementation. Moreover, some antimicrobial strategies and the general host tissue responses regarding collagen as a biomaterial are presented. Finally, the current status and clinical application of the three‐dimensional (3D) printing techniques for the fabrication of collagen‐based scaffolds and the reconstruction of the human heart's constituents, such as capillary structures or even the entire organ, are discussed. Besides, an overall outlook for the future of this unique biomaterial is provided.
Antiosteoporotic effect of hesperidin against ovariectomy‐induced osteoporosis in rats via reduction of oxidative stress and inflammation
Authors: Zhang Qiang , Song Xiaoxia , Chen Xiaoming , Jiang Ruizhong , Peng Ke , Tang Xinqiao , Liu Zhong
Published: May 2021

Osteoporosis is a serious health problem, especially in geriatric patients. Worldwide, it affects 8.9 million people every year. Oxidative stress and inflammation expand the osteoporosis reaction. Hesperidin supplement helps to decrease inflammation and oxidative stress. In this study, we estimated the antiosteoporotic effect of hesperidin against the ovariectomized (OVX) rat model of osteoporosis. Hesperidin was orally administered at 5, 10, and 20 mg/kg to OVX rats for 10 weeks. Different biochemical parameters, such as alkaline phosphatase (ALP), osteocalcin (OC), phosphorus (P), calcium (Ca), and antioxidant parameters, were also estimated. The three‐point bending test, bone mineral density (BMD), and histomorphometric features of the femoral bone were also scrutinized. Hesperidin significantly decreased body weight and increased uterine weight. Hesperidin significantly reduced the ALP, OC, acid phosphatase, and β‐isomerized C‐terminal telopeptides levels in OVX rats. Hesperidin considerably increased BMD and dose‐dependently reduced the pixel density. Hesperidin considerably increased the maximum load, energy, stiffness, maximum stress, and young modulus. Hesperidin significantly (p < 0.001) reduced the levels of thiobarbituric acid reactive substance and increased the level of superoxide dismutase, glutathione, glutathione peroxidase, catalase in OVX‐induced rats. Hesperidin significantly diminishes the cytokine levels, such as tumor necrosis factor‐α, interleukin‐6 (IL‐6), and IL‐1β, and inflammatory mediators such as nuclear factor‐kappa B. It significantly reduced the level of Ca, P, and increased the level of vitamin D in OVX rats. Hesperidin significantly (p < 0.001) reduced the expression of sirtuin 1. Collectively, we can conclude that hesperidin exhibited better protection against osteoporosis by enhancing the bone density and bone mineral content in addition to biomechanical parameters.
Serum HDL cholesterol uptake capacity in subjects from the MASHAD cohort study: Its value in determining the risk of cardiovascular endpoints
Authors: Aghasizadeh Malihe , Samadi Sara , Sahebkar Amirhossein , Miri‐Moghaddam Ebrahim , Esmaily Habibollah , Souktanloo Mohamad , Avan Amir , Mansoori Amin , Ferns Gordon A. , Kazemi Tooba , Ghayour‐Mobarhan Majid
Published: May 2021

Background

The efficiency of high‐density lipoprotein (HDL) to efflux cholesterol contributes to the reverse cholesterol transport (RCT) pathway as one of HDL’s proposed functions and depends on the ability of HDL to uptake cholesterol. We aimed to investigate cholesterol uptake capacity (CUC) by a newly developed assay in samples from the MASHAD (Mashhad Stroke and Heart Atherosclerotic Disorders) cohort study.

Method

The study population comprised 153 individuals developed CVD diagnosed by a specialist cardiologist, over 6 years of follow‐up, and 350 subjects without CVD. We used a modified CUC method to evaluate the functionality of HDL in serum samples.

Result

The CUC assay was highly reproducible with values for inter‐ and intra‐assay variation of 13.07 and 6.65, respectively. The mean serum CUC was significantly lower in the CVD group compared to control (p = 0.01). Although, there were no significant differences in serum HDL‐C between the groups and there was no significantly association with risk of progressive CVD. Multivariate logistic regression analysis showed that there was a significantly negative association between CUC and risk of CVD after adjustment for confounding parameters (OR = 0.57, 95% CI = 0.38–0.87, p = 0.009). The CUC was also inversely and independently associated with the risk of CVD event using Cox proportional hazards models analysis (HR = 0.62; 95% CI = 0.41–0.94, p = 0.02). We determined the optimum cutoff value of 1.7 a.u for CUC in the population. Furthermore, the CUC value was important in determining the CVD risk stratification derived from data mining analysis.

Conclusions

Reduced HDL functionality, as measured by CUC, appears to predict CVD in population sample from north‐eastern Iran.
Two novel SASH1 mutations in Chinese families with dyschromatosis universalis hereditaria
Authors: Liu Jia‐Wei , Habulieti Xiaerbati , Wang Rong‐rong , Ma Dong‐Lai , Zhang Xue
Published: May 2021

Background

Dyschromatosis universalis hereditaria (DUH) is a rare genodermatosis characterized by hyper‐ and hypo‐pigmented macules on the face, trunk, and extremities. The condition causes severe cosmetic problem which can lead to significant psychological distress to the patients and bear a negative impact on society. DUH is a condition with genetic heterogeneity. The SASH1 gene was recently identified as pathogenic genes in DUH patients.

Methods

Two families clinically diagnosed with dyschromatosis universalis hereditaria were enrolled. Whole‐exome sequencing combined with Sanger sequencing and bioinformatics analysis was performed in the probands. MutationTaster, CADD, SIFT, PolyPhen‐2, and LRT software, and The American College of Medical Genetics and Genomics Standards and Guidelines were employed to assess the pathogenicity of detected missense mutations. One hundred healthy unrelated Chinese individuals were used as controls. All participants signed an informed consent form.

Results

Genetic screening revealed a heterozygous SASH1 c.1547G>A (p.Ser516Asn) mutation for patients in family 1, and SASH1 c.1547G>T (p.Ser516Ile) for family 2. Both such de novo mutations are located in a highly conserved SLY domain in SASH1, have not been previously reported in any publication, and were not detected in any control databases.

Conclusions

The novel heterozygous mutations, SASH1 c.1547G>A and c.1547G>T, are likely responsible for the DUH phenotype in these two families. Our study expands the mutation spectrum of DUH. Whole‐exome sequencing showed its efficiency in the diagnostic of hereditary skin disorders.
Temporal and spatial characterization of negative regulatory T cells in HIV‐infected/AIDS patients raises new diagnostic markers and therapeutic strategies
Authors: Chen Hui , Ren ChuanLu , Song HuaFeng , Ma Li‐Ling , Chen Su‐Fang , Wu Min‐Juan , Zhang HuiDan , Xu Jun‐Chi , Xu Ping
Published: May 2021

Background

Negative regulatory T cells (Tregs) not only deplete effector T cells but also inhibit the clearance of HIV during infection, which may allow Tregs to be used as informative diagnostic markers. To facilitate both diagnosis and treatment, a thorough understanding of these regulators by characterizing them on temporal and spatial scales is strongly required.

Methods

Hundred HIV‐infected/AIDS patients, including 87 males, with an average age of 35.8 years, as well as 20 healthy controls, were enrolled. Flow cytometry was used to analyze CD3+T cells, CD4+T cells, and CD8+T cells to evaluate the immune status of the participants. Then, a group of representative negative regulatory T cells, including CD4+PD‐1+T cells, CD4+PD‐1highT cells, CD8+PD‐1+T cells, and CD4+CD25high Tregs was also analyzed to explore their effects on disease progression and intercorrelation.

Results

The percentages of CD4+PD‐1+T cells and CD4+CD25highTregs increased in patients with the same ultrahigh significance. Temporally, the patients with both intermediate‐stage and late‐stage disease had higher percentages of CD4+PD‐1+T cells; however, the percentage of CD4+CD25highTregs only increased in the patients with late‐stage disease. In addition, CD4+PD‐1+T cells but not CD4+CD25highTregs were negatively correlated with the absolute CD4+T cell count. Spatially, no correlations between CD4+PD‐1+T cells and CD4+CD25highTregs were observed, which suggests these Tregs function differently during immunosuppression.

Conclusions

This study characterized negative regulatory T cells in HIV‐infected/AIDS patients at both temporal and spatial scales and found that CD4+CD25+Tregs and CD4+PD‐1+T cells could be used as potential diagnostic markers for identifying different disease stages and monitoring disease progression.
Prevalence of superficial‐cutaneous fungal infections in Shiraz, Iran: A five‐year retrospective study (2015–2019)
Authors: Khodadadi Hossein , Zomorodian Kamiar , Nouraei Hasti , Zareshahrabadi Zahra , Barzegar Sajjad , Zare Mohammad Reza , Pakshir Keyvan
Published: May 2021

Background

Superficial and cutaneous fungal infections are common in tropical areas. The aim of this study was to provide a basic database of superficial and cutaneous mycoses and the most common etiological agents among patients.

Methods

Between 2015 and 2019, a total of 1807 patients suspected of superficial and cutaneous mycosis referring to the mycology laboratory of Shiraz medical school, Fars, Iran were evaluated. Specimens were taken from the patients’ affected area, and clinical samples were examined by direct microscopy and culture. The epidemiological profile of the patients was collected.

Results

A total of 750 patients were confirmed with mycoses. Positive samples totaled 750 cases consisting of the nail (373/49.7%), skin (323/43%), head (47/6.26%), and mucosal membrane (4/0.5%). The yeasts group included 304 Candida spp. (70.3%), 123 Malassezia spp. (28.47%), and 5 Rhodotorula spp. (1.1%). The filamentous fungi were distributed as 34.8% dermatophytes and 7.5% non‐dermatophyte. The clinical types of dermatophytosis were tinea unguium (110/261), tinea capitis (50/261), tinea pedis (48/261), tinea corporis (37/261), and tinea cruris (16/261). Non‐dermatophyte molds included A. flavus 17, A. niger 4, Aspergillus spp. 15, Penicillium. 10, Fusarium 6, Mucor 2, Stemphylium 1, and Alternaria 1.

Conclusion

This study provides useful data for the study trends of superficial and cutaneous fungal infections in a specific area. The mycological data confirmed higher incidence of candidiasis (mainly onychomycosis) and dermatophytosis in patients affected by fungal pathogens, which helped to better understand the epidemiological aspects of these mycoses.