bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chronic Urogenital Schistosomiasis among In-School Adolescents in Sokoto, North-Western Nigeria
Authors: Jiya Fatima Bello , Jiya Nma Muhammed , Ibitoye Paul Kehinde , Mohammed Yahaya , Mohammad Ango Umar 
Published: February 2022

Aims: To assess the prevalence, intensity, associated factors and predictors of chronic urogenital schistosomiasis among in-school adolescents in Sokoto.
Study Design: Descriptive cross-sectional survey.
Place and Duration of Study: Secondary Schools in Sokoto metropolis, Sokoto State, Nigeria, between January and April 2018.
Methodology: A total of 590 apparently healthy secondary school students aged between 10 and 19 years in Sokoto metropolis were selected using multi-stage random sampling technique. Designed pretested semi-structured questionnaire was used to obtain relevant socio-demographic and clinical information. Urine specimen was obtained and subjected to urine analysis and microscopy for ova of Schistosoma haematobium. Data was analyzed using IBM-SPSS version 25.0.
Results: Mean age of subjects was 15.1 ±2.6 years. There were 334 (56.6%) males and 256 (43.4%) females. Majority 371 (62.9%) attended public secondary schools, most 264 (44.7%) were of middle socio-economic family status, and 300 (50.8%) were from rural community setting. The commonest source of water for domestic use was pipe-borne 203 (34.4%), and swimming was the predominant 55(9.3%) recreational water- related activity. The overall prevalence of chronic urogenital schistosomiasis was 22.9%, significantly (p<0.001) higher among males, with age group category 15-17 years mostly 59 (29.6%) affected. All 135 (100%) of the infected subjects had microscopic haematuria, 119 (88.2%) had proteinuria, and 108(80.0%) had leucocyturia. Age group category 15-17 years (p=0.027), male gender (p<0.001), low and middle social classes (p<0.001) respectively, and residence in rural community setting were independent predictors of chronic urogenital schistosomiasis infection. Majority 81(60.0%) of the infected respondents had light infection. Male gender was the only predictor (p=0.003) of intensity of infection.
Conclusions: Chronic urogenital schistosomiasis is prevalent among the subjects. Middle adolescence, male gender, swimming, rural community setting and low-middle socio-economic classes were independent predictors of infection.
Time to Negative Test Result among Patients with COVID-19: A Retrospective Study
Authors: Bob-Manuel Mienye , Omunakwe Hannah , Uzosike Tondor , Enyinnaya Stella , Wondah Faith , Alabi Ajibola 
Published: February 2022

Background: Coronavirus disease 2019 (COVID-19) is a public health emergency, however, there is still limited data on the length of infectiveness of the disease especially in Nigeria. The aim of this study was to ascertain the duration of viral shedding in patients testing positive for COVID-19 to deduce the appropriate time to discharge SAR-CoV2 Positive patients from follow-up by the healthcare team in our setting.
Methods: In this retrospective study, time to a negative test result in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was evaluated in a cohort of 490 patients who tested positive at the Satellite Molecular Laboratory of the Rivers State University Teaching Hospital, Port Harcourt.
Results: The mean age of the 490 patients was 39.8 ± 13.9. There were 379 (77.3%) males and 111 (22.7%) females. The mean duration of SARS-CoV-2 RNA detection was approximately 15±2 days. When comparing patients who were tested twice with those who were tested more than two times, a significant difference between mean time to a negative result and the number of tests done was identified (t= P-Value = <0.001).
Conclusions: Findings from this study show that the average time of transition from a positive to negative PCR test result was approximately 15 days, regardless of the gender. This can provide an estimated duration of hospital stay among COVID-19 patients to prevent unnecessary healthcare costs and minimize re-infection.
Formulation of Silver Nanoparticles using Gymnema sylvestre Leaf Extract and In-vitro Anti-diabetic Activity
Authors: Chavan Ajinkya B. , Goyal Swapnil , Patel Ansar M. 
Published: February 2022

Aim: Formulation of Silver Nanoparticles Using Gymnema sylvestre Leaf Extract and In-Vitro Anti-diabetic Activity.
Place and Duration of the Study: The present work has been carried out between April-2021 to July-2021 and at Mandasur University Mandsaur, Madhya Pradesh-458001.
Methodology: A versatile technique was implemented for the synthesis of silver nanoparticles using aqueous and alcoholic extract of leaves of Gymnema sylvestre. The Ag-NP was subjected to UV, FTIR, XRD, and particle size analysis. The silver nanoparticles Gymnema sylvestre evaluated its anti-diabetic activity by inhibiting the enzymes α-amylase.
Results: The reduction of silver nitrate to silver nanoparticles was confirmed by UV-Vis spectrophotometer showing a typical resonance (SPR) at about 400 nm which is specific for Ag-NPs. In FT-IR analysis the strong band peak at 3355 cm-1 in the extract is vibration bands, which may be due to the overlapping of amine N-H stretching bands. SEM and EDX images reveal that the particles are spherical and the relatively uniform shape of the silver nanoparticles was confirmed in the range of 70-100 nm in extract, whereas DLS showed good zeta potential and less particle size.
Conclusions: The silver nanoparticles that were biologically synthesized from Gymnema sylvestre were economical, non-toxic, and environmentally benign. Due to the reducing and capping nature of the bioactive Phyto-compounds, present in the aqueous extracts. This extract is found to be suitable for the green synthesis of silver nanoparticles. Synthesized silver nanoparticles exhibit the highest level of anti-diabetic activity by inhibiting carbohydrate metabolizing enzymes such as α-amylase. Therefore, synthesized nanoparticles can be a good therapeutic agent for controlling diabetes by inhibiting enzymes that hydrolyze carbohydrates.
High Efficiency Perovskite Solar Cells Employing Quasi‐2D Ruddlesden‐Popper/Dion‐Jacobson Heterojunctions
Authors: Li Kang , Yue Shengli , Li Xing , Ahmad Nafees , Cheng Qian , Wang Boxin , Zhang Xuning , Li Shilin , Li Yanxun , Huang Gaosheng , Kang Hui , Yue Tong , Zafar Saud Uz , Zhou Huiqiong , Zhu Lina , Zhang Yuan 
Published: February 2022

AbstractWhile 2D Ruddlesden‐Popper (RP) perovskites exhibit attractive opto‐electronic properties and stability for use in perovskite solar cells (PSCs), their complicated film‐forming processes often induce a non‐negligible level of defects that significantly undermine the power conversion efficiency (PCE) and stability of PSCs. Here, the use of two organic ammonium salts with the same chain length, namely monoammonium (butylammonium iodide, BAI) and diammonium (1,4‐butanediamine dihydroiodide, BDAI2) for surface defect passivation of RP‐2D perovskite films of (AA)2MA4Pb5I16 (n = 5) are reported. It is found that the diammonium BDAI2 not only effectively reduces the defect density (similarly to using monoammonium BAI) but forms a Dion‐Jacobson (DJ) 2D structure to enhance interfacial charge extraction and suppress surface charge recombination. As a result, a boosted PCE of 18.34% has been obtained with a high open‐circuit voltage of 1.24 V. Owing to the enhanced structural integrity of the DJ phase, the RP‐2D/DJ‐2D perovskite heterojunction films exhibit supreme material robustness, which translates to the impressive environmental stability of devices, showing nearly zero‐degradation of the efficiency after 800 h of continuous thermal aging (60 °C) for 800 h. This work enriches the fundamental understanding of the impacts of the DJ‐2D structure on the surface properties of 2D perovskites.
Room‐Temperature Observation of Near‐Intrinsic Exciton Linewidth in Monolayer WS2
Authors: Fang Jie , Yao Kan , Zhang Tianyi , Wang Mingsong , Jiang Taizhi , Huang Suichu , Korgel Brian A. , Terrones Mauricio , Alù Andrea , Zheng Yuebing 
Published: February 2022

AbstractThe homogeneous exciton linewidth, which captures the coherent quantum dynamics of an excitonic state, is a vital parameter in exploring light–matter interactions in 2D transition metal dichalcogenides (TMDs). An efficient control of the exciton linewidth is of great significance, and in particular of its intrinsic linewidth, which determines the minimum timescale for the coherent manipulation of excitons. However, such a control is rarely achieved in TMDs at room temperature (RT). While the intrinsic A exciton linewidth is down to 7 meV in monolayer WS2, the reported RT linewidth is typically a few tens of meV due to inevitable homogeneous and inhomogeneous broadening effects. Here, it is shown that a 7.18 meV near‐intrinsic linewidth can be observed at RT when monolayer WS2 is coupled with a moderate‐refractive‐index hydrogenated silicon nanosphere in water. By boosting the dynamic competition between exciton and trion decay channels in WS2 through the nanosphere‐supported Mie resonances, the coherent linewidth can be tuned from 35 down to 7.18 meV. Such modulation of exciton linewidth and its associated mechanism are robust even in presence of defects, easing the sample quality requirement and providing new opportunities for TMD‐based nanophotonics and optoelectronics.
Micro‐Scale Auxetic Hierarchical Mechanical Metamaterials for Shape Morphing
Authors: Dudek Krzysztof K. , Martínez Julio A. Iglesias , Ulliac Gwenn , Kadic Muamer 
Published: February 2022

AbstractShape morphing and the possibility of having control over mechanical properties via designed deformations have attracted a lot of attention in the materials community and led to a variety of applications with an emphasis on the space industry. However, current materials normally do not allow to have a full control over the deformation pattern and often fail to replicate such behavior at low scales which is essential in flexible electronics. Thus, in this paper, novel 2D and 3D microscopic hierarchical mechanical metamaterials using mutually‐competing substructures within the system that are capable of exhibiting a broad range of the highly unusual auxetic behavior are proposed. Using experiments (3D microprinted polymers) supported by computer simulations, it is shown that such ability can be controlled through geometric design parameters. Finally it is demonstrated that the considered structure can form a composite capable of shape morphing allowing it to deform to a predefined shape.
Intelligent Gold Nanoparticles with Oncogenic MicroRNA‐Dependent Activities to Manipulate Tumorigenic Environments for Synergistic Tumor Therapy
Authors: Wang Xiangdong , Yang Tianfeng , Yu Zhi , Liu Tao , Jin Ronghua , Weng Lin , Bai Yongkang , Gooding J. Justin , Zhang Yanmin , Chen Xin 
Published: February 2022

AbstractTumorigenic environments, especially aberrantly overexpressed oncogenic microRNAs, play a critical role in various activities of tumor progression. However, developing strategies to effectively utilize and manipulate these oncogenic microRNAs for tumor therapy is still a challenge. To address this challenge, spherical nucleic acids (SNAs) consisting of gold nanoparticles in the core and antisense oligonucleotides as the shell are fabricated. Hybridized to the oligonucleotide shell is a DNA sequence to which doxorubicin is conjugated (DNA‐DOX). The oligonucleotides shell is designed to capture overexpressed miR‐21/miR‐155 and inhibit the expression of these oncogenic miRNAs in tumor cells after tumor accumulation to manipulate genetic environment for accurate gene therapy. This process further induces the aggregation of these SNAs, which not only generates photothermal agents to achieve on‐demand photothermal therapy in situ, but also enlarges the size of SNAs to enhance the retention time in the tumor for sustained therapy. The capture of the relevant miRNAs simultaneously triggers the intracellular release of the DNA‐DOX from the SNAs to deliver tumor‐specific chemotherapy. Both in vivo and in vitro results indicate that this combination strategy has excellent tumor inhibition properties with high survival rate of tumor‐bearing mice, and can thus be a promising candidate for effective tumor treatment.
Photoinduced Annulation of N‐Phenylbenzamides for the Synthesis of Phenanthridin‐6(5H)‐Ones
Authors: Wang Nana , Wang Ding , He Yun , Xi Jin , Wang Tao , Liang Yong , Zhang Zunting 
Published: February 2022

AbstractA general concise method for the synthesis phenanthridin‐6(5H)‐ones via photoinduced intramolecular annulation of N‐phenylbenzamides was developed. Under argon atmosphere and room temperature, phenanthridin‐6(5H)‐ones were obtained via irradiation N‐phenylbenzamides with a 280 nm UV lamp in the presence of methanesulfonic acid in toluene. The mechanism is illustrated and believed to proceed in the order of amides tautomerization, 6π‐electric cyclization, [1,5]‐H shift, amide‐imidine tautomerization, keto‐enol tautomerism and evolution hydrogen.magnified image
Catalytic Cycloisomerization of Enyne Diesters Derived From 2‐Propargyloxyarylaldehydes
Authors: Kumar Saini Manoj , Kant Verma Shashi , Basak Ashok K 
Published: February 2022

AbstractA catalytic cycloisomerization of enyne diesters derived from 2‐propargyloxyarylaldehydes is described. The cycloisomerization, catalyzed by 10 mol% In(OTf)3, provides access to 2H‐chromenes bearing diethyl 2‐(hetero)arylidene malonates at 3‐position. This enyne metathesis‐type reaction is also useful for the synthesis of thia‐, aza‐ and quinoline analogs of the 3‐substituted 2H‐chromenes. DDQ mediated oxidative C−N bond formation and further synthetic manipulation enables the conversion of 3‐substituted 2H‐chromene into chromene‐fused molecular scaffold. Pd(0)‐catalyzed intramolecular Heck reaction on suitably substituted 2H‐chromene provides indene‐based molecular scaffold.magnified image
MXene Nanoarchitectonics: Defect‐Engineered 2D MXenes towards Enhanced Electrochemical Water Splitting
Authors: Tang Yi , Yang Chenhui , Xu Xingtao , Kang Yunqing , Henzie Joel , Que Wenxiu , Yamauchi Yusuke 
Published: February 2022

Abstract2D MXenes‐based nanoarchitectures are being actively explored for electrocatalytic water splitting because they possess physical and physiochemical properties that enhance catalytic activity toward the hydrogen evolution reaction and oxygen evolution reaction. This review systematically summarizes current strategies involved in defect engineering, including introducing atomic vacancies and active edges, and doping with metal and non‐metal atoms, which have been employed to achieve high‐efficiency MXenes‐based catalysts. The electronic structures, optimized adsorption/desorption energies of the intermediates, and possible catalytic mechanisms resulting from various defects are disclosed based on combined experimental results and theoretical calculations. Current challenges and future opportunities for the mechanistic investigation and practical application of defective MXenes‐based catalysts are proposed. This report aims to reveal the nature of defective MXenes electrocatalysts and to provide valuable guidelines for designing defective MXenes‐based nanoarchitectures for various catalytic reactions.
Integrated microfluidic devices for in vitro diagnostics at point of care
Authors: Liu Dan , Wang Ying , Li Xingrui , Li Mengmeng , Wu Qiaoyi , Song Yanling , Zhu Zhi , Yang Chaoyong 
Published: February 2022

AbstractGiven the continuous and growing demand for point of care (POC) diagnostic tests, attention has been shifted toward integration and miniaturization of laboratory protocols into “sample‐in‐answer‐out” devices. Microfluidic technologies have been considered an ideal solution to address the requirements of POC diagnostics since many laboratory functions can be miniaturized and incorporated onto a single integrated chip. In this review, we summarize the advances of integrated microfluidic devices for POC diagnostics in the last 3 years. Particularly, we summarize current materials used for microfluidic chip fabrication, discuss the innovation of versatile integrated microfluidic devices, especially the strategies for simplifying sample preparation in manual or self‐driven systems, and new detection methods of microfluidic chips. In addition, we describe new integrated microfluidic devices for POC diagnostics of protein‐targeted immunodiagnostics, nucleic acid molecular tests, and small molecule metabolites analysis. We also provide future perspectives and current challenges for clinical translation and commercialization of these microfluidic technologies.
Repeated anaphylactic reaction after walking following an intraarticular injection of diclofenac etalhyaluronate sodium during a 3‐day period
Authors: Yanagawa Youichi , Jitsuiki Kei , Kushida Yoshihiro , Morohashi Itaru 
Published: February 2022

BackgroundThere has been no English report of repeated anaphylactic reaction after exercise‐induced anaphylaxis due to a single intraarticular injection of diclofenac etalhyaluronate sodium.Case PresentationA 60‐year‐old woman felt dyspnea, generalized itching, and urticaria following hypotension a few minutes after receiving an intraarticular injection of diclofenac etalhyaluronate sodium for the first time. She immediately received intramuscular adrenaline administration and her symptoms subsided. However, she received intermittent injections of adrenaline three times for repeated anaphylactic reactions after walking over a 3‐day period, in addition to complication with Kounis syndrome. She was discharged on foot on day 9 without sequelae.ConclusionPhysicians should have patients who receive intraarticular injection of diclofenac etalhyaluronate sodium walk for a short period and evaluate their status.
The Pseudo‐Natural Product Rhonin Targets RHOGDI
Authors: Akbarzadeh Mohammad , Flegel Jana , Patil Sumersing , Shang Erchang , Narayan Rishikesh , Buchholzer Marcel , Kazemein Jasemi Neda S. , Grigalunas Michael , Krzyzanowski Adrian , Abegg Daniel , Shuster Anton , Potowski Marco , Karatas Hacer , Karageorgis George , Mosaddeghzadeh Niloufar , Zischinsky Mia‐Lisa , Merten Christian , Golz Christopher , Brieger Lucas , Strohmann Carsten , Antonchick Andrey P. , Janning Petra , Adibekian Alexander , Goody Roger S. , Ahmadian Mohammad Reza , Ziegler Slava , Waldmann Herbert 
Published: February 2022

AbstractFor the discovery of novel chemical matter generally endowed with bioactivity, strategies may be particularly efficient that combine previous insight about biological relevance, e.g., natural product (NP) structure, with methods that enable efficient coverage of chemical space, such as fragment‐based design. We describe the de novo combination of different 5‐membered NP‐derived N‐heteroatom fragments to structurally unprecedented “pseudo‐natural products” in an efficient complexity‐generating and enantioselective one‐pot synthesis sequence. The pseudo‐NPs inherit characteristic elements of NP structure but occupy areas of chemical space not covered by NP‐derived chemotypes, and may have novel biological targets. Investigation of the pseudo‐NPs in unbiased phenotypic assays and target identification led to the discovery of the first small‐molecule ligand of the RHO GDP‐dissociation inhibitor 1 (RHOGDI1), termed Rhonin. Rhonin inhibits the binding of the RHOGDI1 chaperone to GDP‐bound RHO GTPases and alters the subcellular localization of RHO GTPases.
Reversible C−C Bond Cleavage of a Cobalt Diketimide into an Elusive Cobalt Aryl Nitrenoid Complex
Authors: Baek Yunjung , Betley Theodore A. 
Published: February 2022

AbstractThe reactivity of (TrL)Co (TrL=5‐mesityl‐1,9‐(trityl)dipyrrin) toward various aryl azides was examined to elucidate the electronic structure and reactivity of dipyrrinato cobalt aryl nitrenoid complexes. Herein, we demonstrate the synthesis of a CoII diketimide complex [(TrL)Co(NC6F5)]2 and its reversible C−C bond cleavage to yield a monomeric Co nitrenoid complex (TrL)Co(NC6F5). Exposure of [(TrL)Co(NC6F5)]2 to an excess amount of an H‐atom donor cleanly affords the CoII anilide complex (TrL)Co(NHC6F5). The half‐order decay of [(TrL)Co(NC6F5)]2 via H‐atom abstraction (HAA) reveals saturation kinetic behavior indicating a pre‐equilibrium between [(TrL)Co(NC6F5)]2 and (TrL)Co(NC6F5) prior to HAA. Furthermore, (TrL)Co(NC6F5) undergoes reductive coupling with another equivalent of azide to furnish the four‐coordinate tetrazido complex (TrL)Co(κ2‐N4(C6F5)2), expulsion of a fluorine atom to afford (TrL)CoF, and N‐group transfer reactivity to PPh3.
Isoselective Hydroformylation of Propylene by Iodide‐Assisted Palladium Catalysis
Authors: Sigrist Michel , Zhang Yang , Antheaume Cyril , Dydio Paweł 
Published: February 2022

AbstractIsobutanal is a high value bulk material that, in principle, could be produced with 100 % atom‐economy by isoselective hydroformylation of propylene with syngas. However, leading industrial Rh‐ and Co‐catalyzed hydroformylation methods preferentially form n‐butanal over the iso‐product, and methods offering isoselectivity remain underdeveloped. Here we report an iodide‐assisted Pd‐catalyzed hydroformylation of propylene that produces isobutanal with unprecedented levels of selectivity. The method involves PdI2, simple alkyl monophosphines, such as tricyclohexylphosphine, and common green solvents, enabling the title reaction to occur with isoselectivity in up to 50 : 1 iso/n product ratios under industrially relevant conditions (80–120 °C). The catalytic and preliminary mechanistic experiments indicate a key role of the iodide anions in both the catalytic activity and the isoselectivity.
Regio‐, Diastereo‐, and Enantioselective Decarboxylative Hydroaminoalkylation of Dienol Ethers Enabled by Dual Palladium/Photoredox Catalysis
Authors: Zheng Jun , Tang Nana , Xie Hui , Breit Bernhard 
Published: February 2022

AbstractIntermolecular photocatalytic hydroaminoalkylation (HAA) of alkenes have emerged as a powerful method for the construction of alkyl amines. Although there are some studies aiming at stereoselective photocatalytic HAA reactions, the alkenes are limited to electrophilic alkenes. Herein, we report a highly regio‐, diastereo‐, and enantioselective HAA of electron‐rich dienol ethers and α‐amino radicals derived from α‐amino acids using a unified photoredox and palladium catalytic system. This decarboxylative 1,2‐Markovnikov addition enables the construction of vicinal amino tertiary ethers with high levels of regio‐ (up to >19 : 1 rr), diastereo‐ (up to >19 : 1 dr), and enantioselectivity control (up to >99 % ee). Mechanistic studies support a reversible hydropalladation as a key step.
A Moisture‐Assisted Rechargeable Mg−CO2 Battery
Authors: Zhang Chenyue , Wang Aoxuan , Guo Longyuan , Yi Jin , Luo Jiayan 
Published: February 2022

AbstractNew sustainable energy conversion and storage technologies are required to address the energy crisis and CO2 emission. Among various metal–CO2 batteries that utilize CO2 and offer high energy density, rechargeable Mg−CO2 batteries based on earth‐abundant and safe magnesium (Mg) metal have been limited due to the lack of a compatible electrolyte, operation atmosphere, and unambiguous reaction process. Herein, the first rechargeable nonaqueous Mg−CO2 batteries have been proposed with moisture assistance in a CO2 atmosphere. These display more than 250 h cycle life and maintain the discharge voltage over 1 V at 200 mA g−1. Combining with the experimental observations and theoretical calculations, the reaction in the moisture‐assisted Mg−CO2 battery is revealed to be 2 Mg+3 CO2+6 H2O↔2 MgCO3⋅3 H2O+C. It is anticipated that the moisture‐assisted rechargeable Mg−CO2 batteries would stimulate the development of multivalent metal‐CO2 batteries and extend CO2 fixation and utilization for carbon neutrality.