bluuebunny/crossref_metadata_2025 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.
Identification of SSR Markers Linked to Regions Associated with Protein Content in F2 Population of Rice (Oryza sativa L.)
Authors: Sravani D. , Neeraja C. N. , Ravindrababu V. , Reddy M. Rajendar
Published: December 2020

Improvement of rice proteins is important in rice breeding for high nutritional quality. The objective of this study was to identify protein associated regions in the chromosomes in F2 population of the cross derived from swarna and Mahamaya, Parental polymorphism survey between Mahamaya and Swarna was studied using 24 SSR markers. Out of 24 markers, 4 (16%) were polymorphic, 185 F2 plants were assayed individually for protein content and genotyping. Total grain protein content ranged from 4.12 to 12.0 per cent in F2 population. The strategy of selective genotyping was carried out with the F2 plants. The results showed that these three markers RM1369 on chromosome number 6, RM263 on chromosome number 2 and RM337 on chromosome number 8 were unlinked among themselves. Since for mapping a minimum of two markers per locus are required, the data obtained for this study were analyzed by Recombination frequency. Recombination frequency values revealed the association of markers, RM1369 (Chromosome-6) with high protein content (Recombination frequency=0.41) and low protein content (Recombination frequency=0.25), RM263(Chromosome-2) with high protein content (Recombination frequency =0.37%) and low protein content (Recombination frequency =0.33%) and RM337 (Chromosome-8) with high protein content (Recombination frequency =0.22%) and low protein content (Recombination frequency =0.18). This trial study reveals that the above markers can be utilized for identification of regions associated with protein content in rice.
Response of Maize to Different Levels of Zeolite and Nitrogen and Evaluation of Soil Chemical Properties as Influenced by Different Levels of Zeolite and Nitrogen
Authors: Ravali C. H. , Rao K. Jeevan , Anjaiah T. , Suresh K.
Published: December 2020

A pot study was conducted during kharif, 2018-19 in College of Agriculture, Rajendranagar, PJTSAU, Hyderabad, with the aim to evaluate the response of maize to different levels of zeolite and nitrogen and to know the influence of zeolite on selected soil properties. The treatments consists of combinations of 3 levels of nitrogen (100, 150, 200 kg ha-1) and 4 levels of zeolite (0, 2.5, 5, 7.5 t ha-1) along with a control in which only P and K were applied and they were replicated thrice in a factorial completely randomized design. Results indicated that application of zeolite (7.5 t ha-1) and nitrogen (200 kg ha-1) individually had significant effect on N, P, K contents in maize at 30, 60, 90 DAS and at harvest. N and P contents in maize was significantly higher in N200Z7.5 (Nitrogen @ 200 kg ha-1 + Zeolite @ 7.5 t ha-1) however, there was no significant interaction with respect to K content. At harvest, the available P and K were significantly higher in the treatment receiving N100Z7.5.
Combining Ability Effects for Various Agro-Morphological Traits in Rice under Temperate Conditions
Authors: Majid Asma , Parray G. A. , Sofi N. R. , Shikari A. B. , Waza Showkat A.
Published: December 2020

Rice is one of the most consumed food crops in the world and therefore possesses huge socio-economic relevance. Combining ability estimates provide the basis for selection of suitable parents in breeding programmes for rice improvement. The experiment was conducted to evaluate the combining ability effects for various agro-morphological traits in some genotypes of rice. Thirty-four male parents were crossed with the four CMS lines in line × tester matting design and 136 cross combinations were obtained. For most of the traits, SKUA-7A showed desirable GCA effect among the female parental lines; while RL-1, RL-2, RL-11, SKUA-497, SKUA-494, SKUA-496 and SKUA-420 showed desirable GCA effect amongst the male parents. Cross combinations SKUA-7A × RL-3 and SKUA-11A × RL-5 revealed desirable heterosis for most of the traits viz., grain yield, number of effective tillers plant-1, panicle length and number of spikelet panicle-1. These cross combinations also possessed desirable values of SCA effect. In general, the cross combinations showing desirable specific combining ability effects also reveal better per se performance for the respective traits.
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.
In vitro Antifungal Activity of Combination of Miconazole, Salicylic Acid and Benzoic Acid in Two Different Bases against Trichophyton mentagrophytes
Authors: Alamir Hassan Thoulfikar A. , Shayoub M. E. L. A. , Abdalla Wisal G. , Elamin Eltayeb Suliman
Published: December 2020

In vitro activity of miconazole, salicylic acid and benzoic acid against T.richophyton mentagrophytes was done on Sabouraud’s dextrose agar. The inhibition zones were measured in cm. 2.8 cm, 1.5 cm and no inhibition zone were reported for miconazole, salicylic acid and benzoic acid respectively. Synergistic effect of salicylic acid and benzoic acid against T. mentagrophytes was done using two different bases of cream lanette 20% and aqueous cream 30/70. Four different formula each one contain 2% miconazole with different concentrations of salicylic acid and benzoic acid were used. Biggest inhibition zone (5 cm) was observed of lanette cream which contains 2% miconazole, 3% salicylic acid and 6% benzoic acid.
Ocorrência de fogo no Parque Nacional da Chapada dos Veadeiros, Goiás, Brasil: histórico recente no contexto da sua ampliação
Authors: Matos Renata Mariana Póvoa , Aguiar Lívia Lima Leite , Martins Patrick Thomaz de Aquino
Published: December 2020

O presente estudo tem como objetivo aferir, para o período entre 2008 e 2019, o regime de queima no Parque Nacional da Chapada dos Veadeiros (PNCV), Unidade de Conservação (UC) localizada no estado de Goiás que teve sua área ampliada neste período. A partir de imagens dos satélites Landsat e CBERS, cicatrizes de incêndio foram identificadas, vetorizadas e analisadas quanto à localização, ao tamanho e à frequência. A área atual do PNCV queimou cerca de 542.113 hectares, i.e., mais de 225% da área da UC. Aproximadamente 76% das cicatrizes foram registradas na área ampliada do Parque, a qual teve a maior participação de incêndios em 10 dos 11 anos analisados. Foi possível discriminar dois regimes de queima: um que abrange o limite antigo do Parque, caracterizado por baixa ocorrência de queimada, com presença de feições que se assemelham a aceiros e baixa frequência de incêndios; e outro na área ampliada, com histórico de queima anual com valores mais próximos à média, ausência de cicatrizes lineares e frequência máxima de 10 ocorrências. A unificação destes panoramas em um só território exigirá esforços para homogenização dos regimes e poderá, associada a outras ações, diminuir a imprevisibilidade dos incêndios, e respectivos impactos, legitimando o papel que as UCs possuem para a conservação e a preservação da natureza.

Abstract

OCCURRENCE OF FIRE IN THE CHAPADA DOS VEADEIROS NATIONAL PARK, GOIÁS, BRAZIL: RECENT HISTORY IN THE CONTEXT OF ITS EXPANSION

The present study aims to assess, for the period between 2008 and 2019, the burning regime in the Chapada dos Veadeiros National Park (CVNP), Conservation Unit (CU) located in the state of Goiás that had its area expanded in this period. From images of Landsat and CBERS, fire scars were identified, vectorized, and analyzed for their location, size, and frequency. The current area of the CVNP burned about 542,113 hectares, i.e., more than 225% of the area of the CU. Approximately 76% of the scars were recorded in the expanded area of the Park, which had the highest participation of fires in 10 of the 11 years analyzed. It was possible to discriminate two burning regimes: one that covers the old limit of the Park, characterized by the low occurrence of fire, with the presence of features that resemble firebreaks and low frequency of fires; And another in the enlarged area, with a history of annual burning with values closer to the average, absence of linear scars and a maximum frequency of 10 occurrences. The unification of these panoramas in a single territory will require efforts to homogenize the regimes and may, associated with other actions, reduce the unpredictability of fires, and their impacts, legitimizing the role that CU have in the conservation and preservation of nature.
Ônus excessivo com o pagamento do aluguel: desigualdade no direito à habitação - Vitória/ES
Authors: Muniz Andreia Fernandes , Quadra Tyara Targa
Published: December 2020

O desemprego, a informalidade do trabalho, os baixos salários e o ascendente crescimento dos preços de locação dos imóveis contribuem para ampliar as dificuldades enfrentadas por famílias para manter o pagamento mensal dos aluguéis, o que impacta no componente mais elevado do déficit habitacional: o ônus excessivo. Neste contexto, essa pesquisa busca avaliar e analisar o comprometimento da renda com o pagamento de aluguel para famílias com ganhos até três salários mínimos que residem em 58 bairros do município de Vitória/ES. Para isso, foram comparados dados de renda domiciliar e valores dos aluguéis mínimos e máximos para os bairros pesquisados, tendo como referências as tipologias habitacionais de um quarto e dois quartos. Os resultados demonstram que as famílias de baixa renda, mesmo em áreas periféricas, não podem escolher onde e como morar, havendo bairros e tipologias habitacionais que lhes são inacessíveis.

Abstract

EXTREME RESPONSIBILITY WITH PAYMENT OF RENT: INEQUALITY IN THE RIGHT TO HOUSING - VITÓRIA / ES

Unemployment, informal employment, low pay and rising growth in rental prices for properties contribute to increasing the difficulties faced by families to maintain monthly rent payments, which impacts on the highest component of the housing deficit: extreme responsibility with payment of rent. In this context, this research seeks to evaluate and analyze the commitment of income with the payment of rent for families with earnings of up to three minimum wages living in 58 neighborhoods in the city of Vitória/ES. For this, household income data and minimum and maximum rent values for the neighborhoods surveyed were compared, having as reference the housing types of one bedroom and two bedrooms. the results demonstrate that low-income families, even in peripheral areas, cannot choose where and how to live, with neighborhoods and housing types that are inaccessible.
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

Artificial 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

Pre‐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

Solomon 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

Strained 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

Recent 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

The 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

The 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

Cellular 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

Elucidating 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

Expansion 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

Breast 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

Studies 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.
Virgin Olive Oils from Super‐High‐Density Orchards in California: Impact of Cultivar, Harvest Time, and Crop Season on Quality and Chemical Composition
Authors: Polari Juan J. , Mori Mary , Wang Selina C.
Published: December 2020

The impact of cultivar, harvest time, and crop season on olive fruit characteristics and olive oil quality and minor components composition is assessed for super‐high‐density “Arbequina”, “Arbosana”, and “Koroneiki” in California, United States, during 2016, 2017, and 2018. Fruit oil content reaches a plateau in November for “Arbequina” and “Arbosana,” while the accumulation rate keeps constant until early December for “Koroneiki.” Free fatty acids, diacylglycerols, pyropheophytins, and ΔK are not affected by any of the considered factors. Peroxide value, K232, and K270 decreases with harvest time. Chlorophylls content decreases with harvest time, more rapidly in “Arbequina” and “Arbosana” than in “Koroneiki”. Cultivar is the main factor affecting the fatty acid profile. “Koroneiki” has the highest oleic acid content, followed by “Arbosana” and “Arbequina.” Phenolic and volatile compounds are profoundly affected by cultivars and crop seasons, suggesting the relevance of these factors on the sensory and nutritional properties of virgin olive oil from super‐high‐density cultivars. Stepwise linear discriminant analysis allows selecting suitable markers among fatty acids, phenolic, and volatile compounds for cultivar, crop season, and harvest time discrimination.

Practical Application: This paper constitutes the first report of a multiyear study considering quality and composition in bioactive compounds of super‐high‐density “Arbequina,” “Arbosana,” and “Koroneiki,” planted in California, USA. This information helps processors understand the differences in oil made from the most common super‐high‐density cultivars along harvest times and for growers to make planting and harvesting decisions.
Regioselective Electrochemical Cyclobutanol Ring Expansion to 1‐Tetralones
Authors: Petti Alessia , Natho Philipp , Lam Kevin , Parsons Philip J.
Published: December 2020

A mild electrochemical method for the regioselective preparation of 1‐tetralones under environmentally friendly conditions from readily available cyclobutanols was developed. A series of aromatic‐ and heteroaromatic‐fused 1‐tetralones was accessed through ring expansion of the functionalized cyclobutanols via electrochemical generation of alkoxy radicals and intramolecular cyclization.
Effect of Adding Modified Clays on the Mechanical Behavior of PC/ABS Polymer Blend
Authors: da Silva Gabriela Escobar Hochmuller , Granada Jonas Eichelberger , de Melo Caio César Nogueira , Marini Juliano , de Oliveira Amanda Dantas
Published: December 2020

Bentonite clay is surface modified and incorporated into PC/ABS (70/30) polymer blend by melt mixing in concentrations of 1, 3 and 5 wt% of clay. The efficiency of the treatments is analyzed by Fourier transform infrared spectroscopy (FTIR), x‐ray fluorescence (XRF) and x‐ray diffraction (XRD). Differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) are used to evaluate the blends miscibility and morphology, respectively, and the mechanical behavior is analyzed by tensile tests. The methodologies used are efficient to modify the clay's surface. DSC and SEM showed that the blend remained immiscible with the addition of the fillers. The mechanical test showed an increase in the Young's modulus of the nanocomposite with addition of 1 wt% of the natural clay and a modification in the fracture behavior of the blend, from ductile to brittle, when 3 and 5 wt% of the organophilized clay are used.
Heterogeneity analysis of MRI T2 maps for measurement of early tumor response to radiotherapy
Authors: Tomaszewski Michal R. , Dominguez‐Viqueira William , Ortiz Antonio , Shi Yu , Costello James R. , Enderling Heiko , Rosenberg Stephen A. , Gillies Robert J.
Published: December 2020

External beam radiotherapy (XRT) is a widely used cancer treatment, yet responses vary dramatically among patients. These differences are not accounted for in clinical practice, partly due to a lack of sensitive early response biomarkers. We hypothesize that quantitative magnetic resonance imaging (MRI) measures reflecting tumor heterogeneity can provide a sensitive and robust biomarker of early XRT response. MRI T2 mapping was performed every 72 hours following 10 Gy dose XRT in two models of pancreatic cancer propagated in the hind limb of mice. Interquartile range (IQR) of tumor T2 was presented as a potential biomarker of radiotherapy response compared with tumor growth kinetics, and biological validation was performed through quantitative histology analysis. Quantification of tumor T2 IQR showed sensitivity for detection of XRT‐induced tumor changes 72 hours after treatment, outperforming T2‐weighted and diffusion‐weighted MRI, with very good robustness. Histological comparison revealed that T2 IQR provides a measure of spatial heterogeneity in tumor cell density, related to radiation‐induced necrosis. Early IQR changes were found to correlate to subsequent tumor volume changes, indicating promise for treatment response prediction. Our preclinical findings indicate that spatial heterogeneity analysis of T2 MRI can provide a translatable method for early radiotherapy response assessment. We propose that the method may in future be applied for personalization of radiotherapy through adaptive treatment paradigms.
Calcium phosphate nanocomposites via in situ mineralization in block copolymer hydrogels
Authors: Griffin David M. , Kennedy Mitchell A. , Bhatia Surita R.
Published: December 2020

Significant research has been directed toward producing composites that mimic the micro‐ to nanoscale structure of bone tissue, and it remains a challenge to develop synthetic strategies to create cost‐effective biocomposite materials with nanoscale inorganic domains. In this paper, we report the synthesis of nanocrystalline calcium phosphate minerals in situ in gels of a commercially available block copolymer, Pluronic F127 (F127). Although solutions of F127 have previously been explored as a templating agent for calcium phosphate mineralization, here we demonstrate the synthesis of nano‐sized calcium hydrogen phosphate hydrate directly in F127 gels. Composites formed at pH 7 contained highly crystalline, millimeter‐scale crystals of brushite, while composites created at an initial pH of 11 contained nanoscale particles of a calcium hydrogen phosphate hydrate similar to natural bone apatite in morphology and size, with a mean particle diameter of 120 nm. The in situ composites have storage moduli of 15–25 kPa, which is comparable to mechanically processed hydrogel composites containing four times more inorganic material. We believe that our synthetic strategy may provide a new class of versatile and cost‐effective nanostructured biomaterials for use in understanding and replicating mineralized tissues.
Metastereotypes impairing doctor–patient relations: The roles of intergroup anxiety and patient trust
Authors: Xu Lulu , Sun Lining , Li Jiqiang , Zhao Huanhuan , He Wen
Published: December 2020

This study examined whether patients' negative metastereotypes undermine their perception of doctor–patient relations through raising their intergroup anxiety and decreasing their trust level. One hundred twenty‐four outpatients from a Chinese hospital participated in this study; they were randomly assigned to either the negative metastereotype activation (NMSA) or the non‐NMSA condition according to different instructions. Then, they were asked to complete the Intergroup Anxiety, Patient Trust, and Doctor–Patient Relations Scale. Patients' negative metastereotypes undermined doctor–patient relations through the mediation of intergroup anxiety and patient trust (i.e., the independent mediation effect of intergroup anxiety and patient trust) and the serial mediation effect of intergroup anxiety and patient trust. These findings suggest that future research consider intergroup anxiety and patient trust in developing interventions to improve doctor–patient relations.
Sets without k‐term progressions can have many shorter progressions
Authors: Fox Jacob , Pohoata Cosmin
Published: December 2020

Let fs, k(n) be the maximum possible number of s‐term arithmetic progressions in a set of n integers which contains no k‐term arithmetic progression. For all fixed integers k > s ≥ 3, we prove that fs, k(n) = n2 − o(1), which answers an old question of Erdős. In fact, we prove upper and lower bounds for fs, k(n) which show that its growth is closely related to the bounds in Szemerédi's theorem.
Comparative Study on the Outcome of Periorbital Wrinkles Treated with Laser-Assisted Delivery of Vitamin C or Vitamin C Plus Growth Factors: A Randomized, Double-blind, Clinical Trial
Authors: Machado Barbara Helena Barcaro , Frame James , Zhang Jufen , Najlah Mohammad
Published: December 2020

Background

Despite promising results, laser-assisted drug delivery (LADD) is not yet considered as standard therapies and published data rely mainly on laboratory tests, animal experiments or cadaver skin.

Objectives

This double-blind, prospective, randomized clinical trial investigates the impact in topical application of vitamin C and a cosmeceutical containing growth factors (GFs) on periorbital wrinkles primarily treated with laser skin resurfacing.

Material and Methods

In total, 149 female patients with periorbital wrinkles were consented and randomized into two study groups, R-C (receiving vitamin C only) and R-CGF (receiving vitamin C and a cosmeceutical containing growth factors). The statistical analysis evaluated the efficacy of each treatment regimen using software readouts provided by a three-dimensional stereophotogrammetry system prior to treatment and three months after the procedure. Results were compared to confirm if there was a significant change in the skin roughness and the average depth of the wrinkles between the two groups after treatment.

Results

There was a significant reduction in both skin roughness and average depth of the wrinkles in the group treated with vitamin C and growth factors (p <0.01) than those treated with LADD followed by topical application of vitamin C alone. There were no cutaneous reactions or adverse systemic reactions observed in this study related to LADD with vitamin C and GFs.

Conclusion

Controlled laser application might have a great potential to facilitate the absorption of exogenous macromolecules by the skin. Periorbital wrinkles were reduced in both groups, but LADD using vitamin C and GFs provided significantly better results.

Level of Evidence II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.
Assessing causality in epidemiology: revisiting Bradford Hill to incorporate developments in causal thinking
Authors: Shimonovich Michal , Pearce Anna , Thomson Hilary , Keyes Katherine , Katikireddi Srinivasa Vittal
Published: December 2020

The nine Bradford Hill (BH) viewpoints (sometimes referred to as criteria) are commonly used to assess causality within epidemiology. However, causal thinking has since developed, with three of the most prominent approaches implicitly or explicitly building on the potential outcomes framework: directed acyclic graphs (DAGs), sufficient-component cause models (SCC models, also referred to as ‘causal pies’) and the grading of recommendations, assessment, development and evaluation (GRADE) methodology. This paper explores how these approaches relate to BH’s viewpoints and considers implications for improving causal assessment. We mapped the three approaches above against each BH viewpoint. We found overlap across the approaches and BH viewpoints, underscoring BH viewpoints’ enduring importance. Mapping the approaches helped elucidate the theoretical underpinning of each viewpoint and articulate the conditions when the viewpoint would be relevant. Our comparisons identified commonality on four viewpoints: strength of association (including analysis of plausible confounding); temporality; plausibility (encoded by DAGs or SCC models to articulate mediation and interaction, respectively); and experiments (including implications of study design on exchangeability). Consistency may be more usefully operationalised by considering an effect size’s transportability to a different population or unexplained inconsistency in effect sizes (statistical heterogeneity). Because specificity rarely occurs, falsification exposures or outcomes (i.e., negative controls) may be more useful. The presence of a dose-response relationship may be less than widely perceived as it can easily arise from confounding. We found limited utility for coherence and analogy. This study highlights a need for greater clarity on BH viewpoints to improve causal assessment.
We moeten innovatief blijven
Authors: Mulders Peter F.A.
Published: December 2020

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