bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical Profile of the Stem Extract of Costus afer (Bush Cane) from Imo State in Nigeria
Authors: Chioma Anyiam C. , Albert Anyiam C. , Kenechukwu Anozie J. 
Published: December 2020

Aim: The aim of the study was to investigate the chemical profile of the stem extract of Costus afer (Bush cane).
Methodology: Fresh stems of Costus afer were obtained from Obizi in Ezinihitte Mbaise Local Government Area of Imo State. The stem extract of Costus afer a medicinal important plant of the Costaceae were extracted with hot water (aqueous extraction) and proximate composition were determine through AOAC method. Fatty acids were determined through saponification and fatty acid methyl esters were thrice extracted from the mixture with redistilled n-hexane. The phytochemicals of the stem extract were determined by GC/MS analysis.
Results: Proximate composition of stems of Costus afer showed that it contained moisture (22.15%), crude fat (1.15%), ash (4.60%), crude protein (7.72%), crude fibre (9.40%) and carbohydrate (54.98%) while its calorific value is 261.15 kcal/100 g. Phytochemical analyses revealed the presence of alkaloids (70.59 mg/100 g) ranging from papaverine (44.72%) to narcotine (14.11%). Total flavonoids (28.29 mg/100 g) consisted mainly of myricetin (69.79%), quercetin (14.88%) and kaemferol (9.78%). The saponins (2.87 mg/100 mg) consisted mainly of sapogenin (39.20%), saponine (22.12%) and diosgenin (26.13%) while the glycosides (22.35 mg/100 mg) consisted mainly of costugenin (65.60%), digitoxin (18.73%), digoxin (6.28%) and salicin (4.76%). The fatty acid composition showed moderate concentrations of linolenic acid (32.27%), linoleic acid (25.90%), palmitic acid (25.48%) and low concentrations of oleic acid (7.11%) and stearic acid (6.37%).
Conclusion: Chemical studies on Costus afer have reported the presence of alkaloids, saponins, glycosides and flavonoids as the main constituents and were confirmed by phytochemical screening. As a rich source of bioactive compound coupled with the presence of the nutrients the stem of Costus afer studied can be seen as a potential source of food, drugs, fodder and a good source of important nutrients for livestock.
Queue Management during Health Pandemics: A Queuing Theory Perspective
Authors: Nawusu Yakubu Abdul-Wahab , Danaa Abukari Abdul Aziz , Ismail Shiraz 
Published: December 2020

The era of coronavirus has called for sustained social distancing measures to minimize the spread of the viral disease. Healthcare establishments are reducing the size of their working staff; while others are running their outfits base on shift work in other to ensure protocols for social distancing. Inherent in social distancing protocol is the potential for generating waiting lines at service delivery points. Healthcare centres in many countries are already inundated with loads of patient’s attendance on daily basis for treatment off mild to severe ailments. COVID-19 has added a further burden on the already frail health systems. Whiles visits are increasing, social distancing measures are to be ensured. Quick service delivery which is an indispensable need of patients visiting hospitals for treatment is shortened. The occurrence of waiting line, an impediment to healthcare provision has become commonplace in most healthcare centres in Ghana in particular. In addition to loss of financial gains, delay and unsatisfactory healthcare could lead to loss of lives. Health units are dealing with the effective management of staff schedules to curtail the impact of COVID-19 and at the same time cover up capacity to meet the added health care delivery demands. Accordingly, efforts to reduce time spent in waiting to receive medical attention is crucial. In this paper we study the queue situation at a case Outpatient Department (OPD) by applying query theory and offer recommendations for queue management. The study was conducted in the month of May 2020. We present also, an approach to determine the optimal number of service windows required to reduce the time spent waiting for healthcare attention. Numerical analysis of the queuing situation at the case department is given also, drawing from relevant equations from queuing theory.
Molecular Characterization of blaCTX-M, blaTEM and blaSHV Beta Lactamases Produced by Uropathogens
Authors: Bhasin Ashna , Chander Yogesh , Manocha Harmesh 
Published: December 2020

Background: This prospective study was carried out to look for the frequency of isolation of Extended spectrum b lactamase (ESBL) producing bacteria from urine samples and study their susceptibility pattern. The detection of ESBL genes responsible for their resistance was done by Polymerase chain reaction (PCR).
Methods: The study was carried out over a period of one year from January 2016 to December 2016. Urine specimens from patients were processed as per standard protocol. Antimicrobial susceptibility testing was performed by disk diffusion method as per CLSI guidelines 2016.
Urine isolates obtained were screened for ESBL, by cefotaxime, ceftazidime disk and confirmation was made by Double disk diffusion test method. The detection of ESBL genes responsible for their resistance was done by Polymerase chain reaction (PCR) for blaCTX-M, blaTEM and blaSHV genes.
Results: Prevalence of ESBL producing uropathogens were found to be 20.47% with most common organism to be isolated was Escherichia coli (E. coli) followed by Klebsiella pneumoniae. Nitrofurantoin and Imipenem were the most effective antibiotic agents against urinary isolates. Most common gene responsible for ESBL production was blaCTX-M (71.42%).
Conclusion: A large number of ESBL producing strains are creating significant therapeutic problems. Therefore, monitoring of ESBL production, judicious use of antibiotics and infection control measures are necessary to avoid treatment failures in patients with Urinary Tract Infections (UTI).
Investigation of Queries Related to Antimicrobial Agents Use in a Tertiary Hospital from 2015 to 2018
Authors: Althemery Abdullah U. , Najjar Amal H. AL- , Almalki Mesfer S. , Alfaifi Abdullah A. , Aljassem Ahmed K. , Ahmed Nehad J. , Albassam Ahmad A. 
Published: December 2020

Aim: This study compares factors associated with requests for antimicrobial agents versus those for other types of treatment, contrasting the requests of pharmacists versus those of other health-care staff related to antimicrobial agents.
Methods: A retrospective cross-sectional study was conducted for all requests received from January 1, 2015, to December 31, 2018. A series of chi-squared tests was used to analyze the relationship between different categories. All data analyses were conducted using the R statistical computing language.
Results: In total, 2,423 requests were received from 2015 to 2018, of which antimicrobial agents accounted for 21.67%. The highest percentages of antimicrobial requests by pharmacists were related to administration and dosage forms, pregnancy and lactation, and stability. A majority of the requests were answered using tertiary resources. The most-requested information regarding antimicrobial agents was related to clindamycin.
Conclusion: Because many requests pertaining to antimicrobial agents were made, as a proportion of total drug and poison information centre requests, from 2015 to 2018, pharmacists should maintain and indeed expand their active role to combat antibiotic resistance.
Assembly of Multi‐Spheroid Cellular Architectures by Programmable Droplet Merging
Authors: Cui Haijun , Wang Xianxian , Wesslowski Janine , Tronser Tina , Rosenbauer Jakob , Schug Alexander , Davidson Gary , Popova Anna A. , Levkin Pavel A. 
Published: December 2020

AbstractArtificial multicellular systems are gaining importance in the field of tissue engineering and regenerative medicine. Reconstruction of complex tissue architectures in vitro is nevertheless challenging, and methods permitting controllable and high‐throughput fabrication of complex multicellular architectures are needed. Here, a facile and high‐throughput method is developed based on a tunable droplet‐fusion technique, allowing programmed assembly of multiple cell spheroids into complex multicellular architectures. The droplet‐fusion technique allows for construction of various multicellular architectures (double‐spheroids, multi‐spheroids, hetero‐spheroids) in a miniaturized high‐density array format. As an example of application, the propagation of Wnt signaling is investigated within hetero‐spheroids formed from two fused Wnt‐releasing and Wnt‐reporter cell spheroids. The developed method provides an approach for miniaturized, high‐throughput construction of complex 3D multicellular architectures and can be applied for studying various biological processes including cell signaling, cancer invasion, embryogenesis, and neural development.
Preventive Efficacy of a Tenofovir Alafenamide Fumarate Nanofluidic Implant in SHIV‐Challenged Nonhuman Primates
Authors: Pons‐Faudoa Fernanda P. , Sizovs Antons , Shelton Kathryn A. , Momin Zoha , Niles Jean A. , Bushman Lane R. , Xu Jiaqiong , Chua Corrine Ying Xuan , Nichols Joan E. , Demaria Sandra , Ittmann Michael M. , Hawkins Trevor , Rooney James F. , Marzinke Mark A. , Kimata Jason T. , Anderson Peter L. , Nehete Pramod N. , Arduino Roberto C. , Ferrari Mauro , Sastry K. Jagannadha , Grattoni Alessandro 
Published: December 2020

AbstractPre‐exposure prophylaxis (PrEP) using antiretroviral oral drugs is effective at preventing human immunodeficiency virus (HIV) transmission when individuals adhere to the dosing regimen. Tenofovir alafenamide (TAF) is a potent antiretroviral drug, with numerous long‐acting (LA) delivery systems under development to improve PrEP adherence. However, none has undergone preventive efficacy assessment. Here it is shown that LA TAF using a novel subcutaneous nanofluidic implant (nTAF) confers partial protection from HIV transmission. It is demonstrated that sustained subcutaneous delivery through nTAF in rhesus macaques maintains tenofovir diphosphate concentration at a median of 390 fmol per 106 peripheral blood mononuclear cells, nine times above clinically protective levels. In a non‐blinded, placebo‐controlled rhesus macaque study with repeated low‐dose rectal simian HIVSF162P3 (SHIVSF162P3) challenge, the nTAF cohort has a 62.50% reduction (95% CI: 1.72–85.69%; p = 0.068) in risk of infection per exposure compared to the control. This finding mirrors that of tenofovir disoproxil fumarate (TDF) monotherapy, where 60% protective efficacy is observed in macaques, and clinically, 67% reduction in risk with 86% preventive efficacy in individuals with detectable drug in the plasma. Overall, this nanofluidic technology shows potential as a subcutaneous delivery platform for long‐term PrEP and provides insights for clinical implementation of LA TAF for HIV prevention.
Recognizing African‐American contributions to neurology: The role of Solomon Carter Fuller (1872–1953) in Alzheimer's disease research
Authors: Mohammed Hamzah 
Published: December 2020

AbstractSolomon Carter Fuller (1872–1953) is widely acknowledged as the first African‐American psychiatrist but underappreciated as a pioneer of Alzheimer's disease. He immigrated to the United States from Liberia at age 17 and excelled in his medical career to become associate professor of both pathology and neurology at Boston University by 1921. He was one of five research assistants selected by Alois Alzheimer to work in his laboratory at the Royal Psychiatric Hospital in Munich, an experience that arguably paved the way for trailblazing research in Alzheimer's disease. Dr Fuller was the first to translate much of Alzheimer's pivotal work into English, including that of Auguste Deter, the first reported case of the disease. He published what is now recognized to be the first comprehensive review of Alzheimer's disease, in it reporting the ninth case ever described. His achievements, in a period when African‐American physicians were under‐represented, merit greater recognition.
Flow Technology for Telescoped Generation, Lithiation and Electrophilic (C3) Functionalization of Highly Strained 1‐Azabicyclo[1.1.0]butanes
Authors: Musci Pantaleo , von Keutz Timo , Belaj Ferdinand , Degennaro Leonardo , Cantillo David , Kappe C. Oliver , Luisi Renzo 
Published: December 2020

AbstractStrained compounds are privileged moieties in modern synthesis. In this context, 1‐azabicyclo[1.1.0]butanes are appealing structural motifs that can be employed as click reagents or precursors to azetidines. We herein report the first telescoped continuous flow protocol for the generation, lithiation, and electrophilic trapping of 1‐azabicyclo[1.1.0]butanes. The flow method allows for exquisite control of the reaction parameters, and the process operates at higher temperatures and safer conditions with respect to batch mode. The efficiency of this intramolecular cyclization/C3‐lithiation/electrophilic quenching flow sequence is documented with more than 20 examples.
Prebiotic Phosphorylation and Concomitant Oligomerization of Deoxynucleosides to form DNA
Authors: Jiménez Eddy I. , Gibard Clémentine , Krishnamurthy Ramanarayanan 
Published: December 2020

AbstractRecent demonstrations of RNA–DNA chimeras (RDNA) enabling RNA and DNA replication, coupled with prebiotic co‐synthesis of deoxyribo‐ and ribo‐nucleotides, have resurrected the hypothesis of co‐emergence of RNA and DNA. As further support, we show that diamidophosphate (DAP) with 2‐aminoimidazole (amido)phosphorylates and oligomerizes deoxynucleosides to form DNA—under conditions similar to those of ribonucleosides. The pyrimidine deoxynucleoside 5′‐O‐amidophosphates are formed in good (≈60 %) yields. Intriguingly, the presence of pyrimidine deoxynucleos(t)ides increased the yields of purine deoxynucleotides (≈20 %). Concomitantly, oligomerization (≈18–31 %) is observed with predominantly 3′,5′‐phosphodiester DNA linkages, and some (<5 %) pyrophosphates. Combined with previous observations of DAP‐mediated chemistries and the constructive role of RDNA chimeras, the results reported here help set the stage for systematic investigation of a systems chemistry approach of RNA–DNA coevolution.
Identifying the Critical Anion–Cation Coordination to Regulate the Electric Double Layer for an Efficient Lithium‐Metal Anode Interface
Authors: Xu Rui , Shen Xin , Ma Xia‐Xia , Yan Chong , Zhang Xue‐Qiang , Chen Xiang , Ding Jun‐Fan , Huang Jia‐Qi 
Published: December 2020

AbstractThe persistent efforts to reveal the formation and evolution mechanisms of solid electrolyte interphase (SEI) are of fundamental significance for the rational regulation. In this work, through combined theoretical and experimental model investigations, we elucidate that the electric double layer (EDL) chemistry at the electrode/electrolyte interface beyond the thermodynamic stability of electrolyte components predominately controls the competitive reduction reactions during SEI construction on Li metal anode. Specifically, the negatively‐charged surface of Li metal will prompt substantial cation enrichment and anion deficiency within the EDL. Necessarily, only the species participating in the solvation shell of cations could be electrostatically accumulated in proximity of Li metal surface and thereafter be preferentially reduced during sustained dynamic cycling. Incorporating multi‐valent cation additives to more effectively drag the favorable anionic SEI enablers into EDL is validated as a promising strategy to upgrade the Li protection performance. The conclusions drawn herein afford deeper understandings to bridge the EDL principle, cation solvation, and SEI formation, shedding fresh light on the targeted regulation of reactive alkali metal interfaces.
Palladium(0)‐Catalyzed Enantioselective Intramolecular Arylation of Enantiotopic Secondary C−H Bonds
Authors: Melot Romain , Zuccarello Marco , Cavalli Diana , Niggli Nadja , Devereux Michael , Bürgi Thomas , Baudoin Olivier 
Published: December 2020

AbstractThe enantioselective functionalization of nonactivated enantiotopic secondary C−H bonds is one of the greatest challenges in transition‐metal‐catalyzed C−H activation proceeding by an inner‐sphere mechanism. Such reactions have remained elusive within the realm of Pd0 catalysis. Reported here is the unique reactivity profile of the IBiox ligand family in the Pd0‐catalyzed intramolecular arylation of such nonactivated secondary C−H bonds. Chiral C2‐symmetric IBiox ligands led to high enantioselectivities for a broad range of valuable indane products containing a tertiary stereocenter, as well as the arylation of secondary C−H bonds adjacent to amides. Depending on the amide substituents and upon control of reaction time, indanes containing labile tertiary stereocenters were also obtained with high enantioselectivities. Analysis of the steric maps of the IBiox ligands indicated that the level of enantioselectivity correlates with the difference between the two most occupied and the two less occupied space quadrants, and provided a blueprint for the design of even more efficient ligands.
Prebiotic Peptide Synthesis and Spontaneous Amyloid Formation Inside a Proto‐Cellular Compartment
Authors: Kwiatkowski Witek , Bomba Radoslaw , Afanasyev Pavel , Boehringer Daniel , Riek Roland , Greenwald Jason 
Published: December 2020

AbstractCellular life requires a high degree of molecular complexity and self‐organization, some of which must have originated in a prebiotic context. Here, we demonstrate how both of these features can emerge in a plausibly prebiotic system. We found that chemical gradients in simple mixtures of activated amino acids and fatty acids can lead to the formation of amyloid‐like peptide fibrils that are localized inside of a proto‐cellular compartment. In this process, the fatty acid or lipid vesicles act both as a filter, allowing the selective passage of activated amino acids, and as a barrier, blocking the diffusion of the amyloidogenic peptides that form spontaneously inside the vesicles. This synergy between two distinct building blocks of life induces a significant increase in molecular complexity and spatial order thereby providing a route for the early molecular evolution that could give rise to a living cell.
Spectroscopic Verification of Adsorbed Hydroxy Intermediates in the Bifunctional Mechanism of the Hydrogen Oxidation Reaction
Authors: Wang Yao‐Hui , Wang Xiao‐Ting , Ze Huajie , Zhang Xia‐Guang , Radjenovic Petar M. , Zhang Yue‐Jiao , Dong Jin‐Chao , Tian Zhong‐Qun , Li Jian‐Feng 
Published: December 2020

AbstractElucidating hydrogen oxidation reaction (HOR) mechanisms in alkaline conditions is vital for understanding and improving the efficiency of anion‐exchange‐membrane fuel cells. However, uncertainty remains around the alkaline HOR mechanism owing to a lack of direct in situ evidence of intermediates. In this study, in situ electrochemical surface‐enhanced Raman spectroscopy (SERS) and DFT were used to study HOR processes on PtNi alloy and Pt surfaces, respectively. Spectroscopic evidence indicates that adsorbed hydroxy species (OHad) were directly involved in HOR processes in alkaline conditions on the PtNi alloy surface. However, OHad species were not observed on the Pt surface during the HOR. We show that Ni doping promoted hydroxy adsorption on the platinum‐alloy catalytic surface, improving the HOR activity. DFT calculations also suggest that the free energy was decreased by hydroxy adsorption. Consequently, tuning OH adsorption by designing bifunctional catalysts is an efficient method for promoting HOR activity.
Prelabeling Expansion Single‐Molecule Localization Microscopy with Minimal Linkage Error
Authors: Kang Minsu , Lee Jooyong , Ko Sangyoon , Shim Sang‐Hee 
Published: December 2020

AbstractExpansion microscopy combined with single‐molecule localization microscopy (ExSMLM) has a potential for approaching molecular resolution. However, ExSMLM faces multiple challenges such as loss of fluorophores and proteins during polymerization, digestion or denaturation, and an increase in linkage error arising from the distance between the fluorophore and the target molecule. Here, we introduce a trifunctional streptavidin to link the target, fluorophore and gel matrix via a biotinylizable peptide tag. The resultant ExSMLM images of vimentin filaments demonstrated high labeling efficiency and a minimal linkage error of ∼5 nm. Our ExSMLM provides a simple and practical means for fluorescence imaging with molecular resolution.
M2 macrophages contribute to cell proliferation and migration of breast cancer
Authors: Tu Daoyuan , Dou Jin , Wang Mingkao , Zhuang Haiwen , Zhang Xiaoyu 
Published: December 2020

AbstractBreast cancer is a kind of malignant tumor that severely threatens women's lives and health worldwide. Tumor‐associated macrophages (TAMs) have been reported to mediate tumor progression, while the mechanism still needs further identification. In this study, we found that M2 macrophages promoted increased cell proliferation and migration as well as reduced expression of interferon regulatory factor 7 (IRF7) and increased the expression of miR‐1587 in breast cancer cells. Overexpression of IRF7 or miR‐1587 knockdown reversed M2 macrophage‐induced cell proliferation and migration as well as tumor growth in vivo. Mechanistically, miR‐1587 targeted the 3ʹ‐untranslated region (3ʹ‐UTR) of IRF7 mRNA to regulate its protein expression leading to tumor progression. Collectively, this study revealed that the miR‐1587/IRF7 axis mediates M2 macrophage‐induced breast cancer progression, and this sheds light on further clinical therapy for breast cancer by targeting TAMs as well as the miR‐1587/IRF7 axis.
Cisplatin‐resistant osteosarcoma cell‐derived exosomes confer cisplatin resistance to recipient cells in an exosomal circ_103801‐dependent manner
Authors: Pan Yuanxing , Lin Yunfei , Mi Chuan 
Published: December 2020

AbstractStudies have shown that exosomes can mediate the chemoresistance of drug‐resistant cells by transmitting circular RNAs (circRNAs). However, the role of exosome‐derived hsa_circ_103801 (exosomal hsa_circ_103801) in osteosarcoma (OS) remains unclear. The level of hsa_circ_103801 was upregulated in the serum exosomes from patients with OS, and OS patients with high hsa_circRNA_103801 expression had a shorter survival time relative to patients with low hsa_circ_103801 expression. The expression of hsa_circ_103801 was upregulated in cisplatin‐resistant MG63 (MG63/CDDP) cells compared with that in MG63 cells. In addition, hsa_circ_103801 was highly enriched in exosomes derived from CDDP‐resistant OS cells and could be delivered to MG63 and U2OS cells through exosomes. Exosomes derived from CDDP‐resistant cells were shown to reduce the sensitivity of MG63 and U2OS cells to CDDP, inhibit apoptosis, and increase the expression of multidrug resistance‐associated protein 1 and P‐glycoprotein. Moreover, exosomal hsa_circ_103801 could strengthen the promotive effect of exosomes on the chemoresistance of MG63 and U2OS cells to CDDP. Hence, serum exosomal hsa_circ_103801 may serve as an effective prognostic biomarker for OS, and exosomal hsa_circ_103801 could be a potential target for overcoming OS chemoresistance.