bluuebunny/crossref_metadata_2025 huggingface dataset:
Invasive Factors Recognition in Aspergillus Section Nigri Isolates from Patient and Environmental Samples in the Centre Region, Cameroon
Authors: Itor Ekpo Alfred , Noubom Michel , Nangwat Claude , Ngueguim Dougue Aude , Kountchou Cyrille Levis , Thierry Ngouana Kammalac , Paul Dzoyem Jean , Christopher Tume
Published: October 2020

Background: Aspergillus section Nigri species are invasive opportunistic pathogens, seen in individuals with various immune disorders. The invasive capacity involves the production of varieties of enzymes such as lipases, phospholipase, proteases and hyaluronidase. The determination of proteinase, phospholipase, esterase and biofilm production in patient and environmental isolates approve the pathogenic strength of the species.

Aims: To evaluate the invasive capacity of Aspergillus section Nigri isolates from patients and environmental samples.

Methods: Our study is cross sectional and experimental, performed at the outpatient clinic of the otorhinolaryngology department of Central and University teaching hospital during a period of 12 months from March 2018 to February 2019.  To determine the invasive capacity of Aspergillus section Nigri species, 400 samples were evaluated in the study (that is; 250 from patients and 150 samples from environment). Patient samples and hospital environment samples were evaluated by standard phenotypic methods for detecting of Proteinase, phospolipase, esterase and biofilm. The variables were statistically analyzed using Chi-square test of independent and SPSS (Version 16.0).

Results: The isolates recovered from the patient sample shows maximum invasive capacity as compared to the environmental isolates, that is for 44 isolates;  42 isolates showed proteinase activity and biofilm production, followed by  phospholipase activity 36, and then  esterase 32.The isolates recovered from the hospital environment also showed the production of the various  invasive factors, that is for 16 isolates; 15 isolates showed  biofilm production,  followed by proteinase activity 6,  phospholipase 5 and esterase 4.The disparities of the invasive capacity in patient and environment isolates virulence were statistically significant for proteinase, phospholipase and esterase ( that is; p-value <0.05). Majority the isolates recovered from patients and the environment were potential producers of biofilm.

Conclusion: The isolates recovered from patients sample showed high invasive capacity as compare to the isolates recovered from the environment. This highlights the implications of phospholipase enzyme, proteinase enzyme, esterase enzyme and biofilm used by Aspergillus section Nigri isolates as means of survival in the host system.
Predicting the Toxicities of Ternary Mixtures of two Metals and Sodium Dodecyl Sulfate to Serratia marcescens (SerEW01) from Otamiri River Water
Authors: Okechi Reuben N. , Chukwura Edna I. , Nweke Christian O.
Published: October 2020

Background: Otamiri river server as a source of water for domestic activities, urban farming, recreation, aquatic foods in Owerri and environs. It also receives untreated domestic, industrial and agricultural waste water and run offs from the municipality. Seepages from solid wastes dumps at the river banks and sand mining activity going on in the river could also constitute environmental hazards

Aims: This study aims at evaluating the interactive effects of the ternary mixtures of sodium dodecyl sulfate (SDS) and some divalent metals on preponderant bacterium (Serratia marcescens (SerEW01)) from the river.

Study Design: Fixed ratio ray design was used for the study, with inhibition of dehydrogenase activity as end point.

Place and Duration of Study:    Owerri, Imo State, Nigeria, June – December, 2019.

Methodology: The bacterium was earlier isolated as the preponderant bacterium isolate from the river water. Fixed ratio ternary mixtures (Equieffect concentration (EEC50) and arbitrary concentration (ABCR) ratios), SDS + Pb + Zn, SDS + Cd +Zn, SDS + Pb +Ni, SDS + Ni + Cd, SDS + Co + Pb and SDS + Co + Cd were designed to evaluate the combined toxicities of these toxicants. Toxicities predicted by concentration addition (CA) and independent action (IA) models were compared with the experimentally observed toxicities.

Results: The EC50S observed ranged from 0.046 ± 0.003 mM (Zn) to 2.329 ± 0.092 mM (SDS). The EC50S of the toxicants were statistically different from each other (P<0.05). The order of increasing toxicities were SDS >Pb >Ni > Co > Cd(II) >Zn. Concentration-dependent toxicities with progressive inhibition of the dehydrogenase activity as the concentration increased were observed.. In all ternary mixtures, both the experimentally derived, CA and IA-predicted EC50S were statistically different from each other. Both models predicted lower toxicities compared to the experimental data. The Toxic Index and Model Deviation Ratio indicated synergistic interaction of SDS and metal ions against S. marcescens (SerEW01)

Conclusion: This study could constitute base line information towards assessing the possible environmental hazards associated with co-contamination of the environment by SDS and divalent heavy metals, more so when both pollutants are common aquatic pollutants.
Factors Influencing the Uptake of Cervical Cancer Screening among Female Doctors and Nurses in Kenyatta National Hospital
Authors: Keah Mary Matsezi , Kombe Yeri , Ngure Kenneth
Published: October 2020

Aims: The aim of the study was to assess factors influencing the uptake of cervical cancer screening among female doctors and nurses in Kenyatta National Hospital (KNH) in Kenya. To achieve this cross-sectional study was conducted in KNH between January 2019 and April 2020.

Methodology: Stratified random sampling method was used to select 271 nurses and 39 doctors from a population of 1400 nurses and 301 doctors. Data was collected through a structured close ended questionnaire. Chi-square test of homogeneity was used to determine the association between cancer screening uptake and demographic factors. A multiple regression analysis was used to test the relationship between the determinants (factors) of uptake of cervical cancer screening that included availability of procedures, cost of procedures, time, the attitude of HCW, awareness of procedures, religion, age, culture, multiple sexual partners.  

Results: Findings revealed that 97.5% (n = 272) are aware of cervical screening with most of the participants (95.3%, n = 266) indicating that they have been screened for cervical cancer before. PAP tests and HPV DNA tests were noted to be the most used screening methods. The majority of the participants (14.7%, n = 41) indicate that the major benefit of the cancer screening programs is enhanced early detection/ treatment/care, followed by general awareness on cervical cancer (35, 12.5%). Findings further revealed that the health workers who have ever heard about the vaccine were reported to have higher uptake of cervical cancer screening (Chi=32.158, p = .05, n =262).

Conclusion: Our study identified that lack of adequate health infrastructure and resources is a well-recognized barrier to screening in Kenya.
Effect of Water Stress on Crop Yield and Water Productivity of Drip-irrigated Pepper (Capsicum Spp.) in Southwest Nigeria
Authors: Oluwagbayide Samuel D. , Okusanya Muyiwa A. , Amori Anthony A. , Akintade Joshua O.
Published: October 2020

This research presents the effects of water stress on crop yield and water productivity of two local varieties of pepper (Capsicum spp.) under various drip irrigation regimes in Southwest Nigeria.

Study Design: The study was conducted during the 2018 and 2019 cropping seasons at the Teaching and Research Farm of Agricultural and Bio-Environmental Engineering of Federal Polytechnic, Ilaro, Nigeria.

The experiment was a 2 x 4 factorial experiments arranged in a randomized complete block design (RCBD) with two varieties of pepper (Capsicum chinense and Capsicum frutescens) and four drip irrigation regimes: 100%, 75%, 50% and 25% of actual crop evapotranspiration (ET100, 75, 50, 25) and replicated four times. The experiment was repeated in the second year late season. Water was applied from 3 weeks after transplanting (WAT) after which growth parameters, crop water productivity and crop yield were monitored and subjected to statistical analyses.

The water productivity, crop yield and other crop growth parameters such as plant height, number of leaves, fruit length and weight were higher during the two seasons for the two pepper varieties under ET100 and ET75 irrigation regimes compared with ET50 and ET25 respectively. A significant difference (p<0.05) was observed in the growth parameters in all the treatments. However, there was no significant difference (p>0.05) in the water productivity components for ET100 and ET75 irrigation regimes. The best water productivity was observed for the ET75 drip irrigation regime.

Therefore, the ET75 regime was recommended for the two pepper varieties to ensure sustainable cultivation and production of the two varieties in the study area.
Antioxidant activities of Dichrostachys cinerea (L.) Wight et Arn (Leguminosae): Correlations between the Polyphenol Level and the Antioxidant Activity
Authors: Samseny Reine Raïssa Rolande Aworet , Mengome Line-Edwige , Angone Sophie Aboughe
Published: October 2020

Aims: Free radicals are involved in many diseases. Antioxidants help control them. The overproduction of free radicals or reduction of natural antioxidants promotes the destruction of cells in our body, for example in neurodegenerative diseases. The aim of our study is to evaluate the correlation between the level of polyphenol and antioxidant activity of Dichrostachys cinerea barks he work was carried out at the phytochemistry department of the Institute of Pharmacopoeia and Traditional Medicine (Gabon).

Methodology: Different extracts of Dichrostachys cinerea barks were obtained with polarity solvent (dichloromethane, ethyl acetate, butanol, methanol and water).  The antioxidant activity is evaluating using respectively FRAP method (Ferric Reducing Antioxidant Power), antiradical activity by the method of inhibition of DPPH radical (2.2-diphenyl-1-picrylhydrazyl), cations ABTS radical (2.2'-azinobis-[3-acid-6-sulfonic ethylenzothiazoline]).

Results: Ethyl acetate and dichloromethane extract have the higher value for polyphenolic compounds, respectively 52,27±0,66 mg EAG / g and 49,72±0,55 mg EAG / g. Aqueous extract have the lower value 20,67±1,05 mg EAG / g. The different fractions of Dichrostachys cinerea have antioxidant effect, and this effect is in correlation with its constituents: polyphenols, tannins and flavonoids. Results were compared to standard antioxidants such as ascorbic acid and quercetin.

Conclusion: This study confirms higher is the level of polyphenols greater is the antioxidant power.
Association of dupA, iceA, homB Genes of Helicobacter pylori with Gastritis, Peptic Ulcer Disease and Gastric Cancer
Authors: Bajwa Muhammad Akram , Idrees Muhammad , Maheshwari Prem Kumar
Published: October 2020

Objective: To determine the association of dupA, iceA, homB genes of Helicobacter pylori with gastro-duodenal diseases such as gastritis, peptic ulcer disease PUD and gastric cancer.

Materials and Methods: This cross-sectional analytical study was conducted at Gastroenterology Department, Shaikh Zayed Hospital Lahore. Patients with gastro-duodenal diseases and positive H. pylori were included. Gastric biopsies were taken from fundus, body and antrum. H. pylori DNA were removed utilizing Gentra DNA extraction Kit (Life Technologies, USA) as per the technique and Qualitative PCR for the recognition of H. Pylori DNA. The PCR primers sets were designed for the specific detection of dupA, iceA and homB genes of H. pylori. All the data was recorded in proforma and analyzed by SPSS version 20.

Results: Mean age of the cases was 41.22+8.04 years. Males were more affected 118(60.2%). HomB was the most common 76(38.8%) followed by dupA and iceA 28.6% and 24.5% respectively. Peptic ulcer disease and gastritis were higher among patients having dup A and iceA positive strains as compared to homB gene patients, while gastric cancer was significantly higher among HomB gene infected patients, p-values were quite significant.

Conclusion: It was concluded that homB gene was most frequent in H. pylori infected population. Peptic ulcer disease and gastritis are markedly associated with dupA and iceA genes, while homB gene infected patients are at high risk of gastric cancer.
Olive Oil Based Organogels for Effective Topical Delivery of Fluconazole: In-vitro Antifungal Study
Authors: Ahmed Mohammad Muqtader , Fatima Farhat , Mohammed Abdul Bari
Published: October 2020

The objective of the study was to formulate olive oil based organogels for the topical application of fluconazole (FLZ), to ensure the efficient delivery of the drug deeper in to the skin layers.

Methods: Nine formulations developed by hot-melt method using olive oil, sorbitan monostearate (SMS) and FLZ. Prepared formulations characterized for macro evaluations, pH, spreadibility, viscosity, gel-sol transition, in-vitro diffusion study. Further optimized formulation evaluated for ex-vivo percutaneous permeation, in-vitro antifungal studies and stability studies by similarity index. Results: The results of evaluated parameters ensure the stability and effectiveness of the prepared olive oil based organogels. In-vitro diffusion studied reflects decrease in drug release with increase in surfactant concentration due to increase in viscosity. Moreover, ex-vivo permeation studies revealed that the permeation of FLZ was enhanced for optimized formulations (F6) as compared to the marketed gel formulation. Further, the optimized formulation exhibits the broad zone of inhibition against fungal strains in comparison to control and marketed product during in-vitro antifungal study.

Conclusion: The olive oil based organogels formulation shown the enhanced permeation of FLZ from organogel network structure with good antifungal activity as compared to the marketed formulation. Henceforth, the FLZ organogel formulations could be used topically for the effective treatment of fungal infection.
Recent Advances in Carbon Nanotube Utilizations in Perovskite Solar Cells
Authors: Luo Qiang , Wu Ronggen , Ma Lantian , Wang Chaojun , Liu Hu , Lin Hong , Wang Ning , Chen Yuan , Guo Zhanhu
Published: October 2020

Metal halide perovskite solar cells (PSCs) have emerged as promising next‐generation photovoltaic devices with the maximum output efficiency exceeding 25%. Despite significant advances, there are many challenges to achieve high efficiency, stability, and low‐cost simultaneously. Combating these challenges depends on developing novel materials and modifying conventional device components. Carbon nanotubes (CNTs) have attracted considerable attention for fabricating efficient PSCs owing to their remarkable electrical, optical, and mechanical properties. With their multifunctional features, CNTs can play a wide range of roles and offer unique benefits in various components in PSCs to improve device performance and durability. Here, recent progress concerning the utilizations of CNTs as transparent conductive electrodes, charge‐transporter, perovskite additives, interlayers, hole‐transporting materials, and back electrodes in PSCs is comprehensively reviewed. The application of CNTs toward the development of 1D and 2D flexible PSCs is also discussed. A summary of current challenges and prospective on future research directions of employing CNTs to realize high‐performance PSCs is presented.
Self‐Standing Nanofiber Electrodes with Pt–Co Derived from Electrospun Zeolitic Imidazolate Framework for High Temperature PEM Fuel Cells
Authors: Lim Sung Yul , Martin Santiago , Gao Guohua , Dou Yibo , Simonsen Søren Bredmose , Jensen Jens Oluf , Li Qingfeng , Norrman Kion , Jing Shao , Zhang Wenjing
Published: October 2020

Expedited conversion of O2 to H2O with minimal amounts of Pt is essential for wide applicability of PEM fuel cells (PEMFCs). Therefore, it is imperative to develop a process for catalyst management to circumvent unnecessary catalyst loss while improving the Pt utilization, catalytic activity, and durability. Here, the fabrication of a self‐standing nanofiber electrode is demonstrated by employing electrospinning. This film‐type catalyst simultaneously contains Pt–Co alloy nanoparticles and Co embedded in an N‐doped graphitized carbon (Co–Nx) support derived from the electrospun zeolitic imidazolate frameworks. Notably, the flexible electrode is directly transferrable for the membrane‐electrode assembly of high temperature PEMFC. In addition, the electrodes exhibit excellent performance, maybe owing to the synergistic interaction between the Pt–Co and Co–Nx as revealed by the computational modeling study. This method simplifies the fabrication and operation of cell device with negligible Pt loss, compared to ink‐based conventional catalyst coating methods.
Recapitulation of In Situ Endochondral Ossification Using an Injectable Hypoxia‐Mimetic Hydrogel
Authors: Sun Lili , Ma Yifan , Niu Haoyi , Liu Yutong , Yuan Yuan , Liu Changsheng
Published: October 2020

Due to the limited ability for perfusion, traditional intramembranous ossification (IMO) often fails to recapitulate the natural regeneration process of most long bones and craniofacial bones. Alternatively, endochondral ossification (ECO) strategy has emerged and has been evidenced to circumvent the drawbacks in the routine application of IMO. Here, an injectable, poly(glycerol sebacate)‐co‐poly (ethylene glycol)/polyacrylic acid (PEGS/PAA) hydrogels are successfully developed to induce a hypoxia‐mimicking environment and subsequently recapitulate ECO via in situ iron chelation. With the incorporation of PAA, these hydrogels present remarkable viscoelasticity and high efficacy of iron ion‐chelating after injection, giving rise to the activation of HIF‐1α signaling pathway and suppression of inflammatory responses, and thereby improving chondrogenic differentiation in the early stage and facilitating vascularization in the later stage, which consequently trigger typical ECO. More importantly, through sustained and stable expression of HIF‐1α regulated by PEGS/PAA hydrogels throughout the regeneration, a harmonious chondrogenic/osteogenic balance can be struck and thereby accelerating the progress of ECO compared to the PEGS. The findings provide an efficient strategy to achieve in situ ECO via biomaterial‐based iron ion‐chelating and ensuing hypoxia‐mimicking, representing a novel and promising concept for future application in bone regeneration.
Glial Interfaces: Advanced Materials and Devices to Uncover the Role of Astroglial Cells in Brain Function and Dysfunction
Authors: Maiolo Luca , Guarino Vincenzo , Saracino Emanuela , Convertino Annalisa , Melucci Manuela , Muccini Michele , Ambrosio Luigi , Zamboni Roberto , Benfenati Valentina
Published: October 2020

Research over the past four decades has highlighted the importance of certain brain cells, called glial cells, and has moved the neurocentric vision of structure, function, and pathology of the nervous system toward a more holistic perspective. In this view, the demand for technologies that are able to target and both selectively monitor and control glial cells is emerging as a challenge across neuroscience, engineering, chemistry, and material science. Frequently neglected or marginally considered as a barrier to be overcome between neural implants and neuronal targets, glial cells, and in particular astrocytes, are increasingly considered as active players in determining the outcomes of device implantation. This review provides a concise overview not only of the previously established but also of the emerging physiological and pathological roles of astrocytes. It also critically discusses the most recent advances in biomaterial interfaces and devices that interact with glial cells and thus have enabled scientists to reach unprecedented insights into the role of astroglial cells in brain function and dysfunction. This work proposes glial interfaces and glial engineering as multidisciplinary fields that have the potential to enable significant advancement of knowledge surrounding cognitive function and acute and chronic neuropathologies.
A Drug‐Free Therapeutic System for Cancer Therapy by Diselenide‐Based Polymers Themselves
Authors: Wei Chao , Liang Bingyu , Li Yongsheng , Yan Bingkun , Zhou Yan , Liu Yingbin , Lang Meidong
Published: October 2020

The application of nanotechnology‐based drug delivery systems has resulted in great progresses in cancer therapy. However, current systems ultimately depend on the action of the drug itself and almost all nanocarriers only serve as excipients without any therapeutic efficacy. Herein, a drug‐free therapeutic system is put forward, in which synthetic polymers themselves naturally exhibit effective anticancer activity without the loading of additional chemotherapy drugs. Aiming at this goal, amphiphilic poly(diselenide‐carbonate) copolymers (PSeSeTMC), consisting of monomethyl ether poly(ethylene glycol) and diselenide‐based polycarbonates, are designed and synthesized to build spherical nanoparticles, which show effective and broad‐spectrum anticancer activities against multiple cancer cell lines and high selectivity toward cancer cells. Moreover, the anticancer activities can be well controlled by tuning the selenium contents in polymers. Mechanistic investigations indicate that PSeSeTMC can selectively induce cancer cells to express excessive reactive oxygen species, thereby leading to significant cellular apoptosis. In vivo antitumor studies further demonstrate high therapeutic efficacy and low side effects on normal tissue. Overall, this work provides a novel approach for cancer therapy by utilizing carriers themselves. Considering the fabrication process is pretty simple, this diselenide‐based polymeric system has great potential in clinical translation.
Size‐Transformable Nanostructures: From Design to Biomedical Applications
Authors: Zhang Xiaodong , Chen Xiaokai , Song Jun , Zhang Junmin , Ren Xiangzhong , Zhao Yanli
Published: October 2020

The size of nanostructures (NSs) strongly affects their chemical and physical properties and further impacts their actions in biological systems. Both small and large NSs possess respective advantages for disease theranostics, and this therefore presents a paradox when choosing NSs with suitable sizes. To overcome this challenge, size‐transformable NSs have emerged as a powerful tool, as they can be manipulated to possess the merits of both types of NSs. Herein, various strategies to construct size‐transformable NSs are summarized, and the recent research progress regarding their biomedical applications, particularly within the fields of cancer and bacterial theranostics, is highlighted. This review will inspire researchers to further develop various methods that can be used to construct size‐transformable NSs for use in novel applications within different fields.
Deoxyribonucleic Acid as a Universal Electrolyte for Bio‐Friendly Light‐Emitting Electrochemical Cells
Authors: Tekoglu Serpil , Held Martin , Bender Markus , Yeo Guan Ni , Kretzschmar Andreas , Hamburger Manuel , Freudenberg Jan , Beck Sebastian , Bunz Uwe H. F. , Hernandez‐Sosa Gerardo
Published: October 2020

In the search for bio and eco‐friendly light sources, light‐emitting electrochemical cells (LECs) are promising candidates for the implementation of biomaterials in their device architecture thanks to their low fabrication complexity and wide range of potential technological applications. In this work, the use of the DNA derivative DNA‐cetyltrimethylammonium (DNA‐CTMA) is introduced as the ion‐solvating component of the solid polymer electrolyte (SPE) in the active layer of solution‐processed LECs. The focus is particularly on the investigation of its electrochemical and ionic conductivity properties demonstrating its suitability for device fabrication and correlation with thin film morphology. Furthermore, upon blending with the commercially available emissive polymer Super Yellow, the structure property relationship between the microstructure and the ionic conductivity is investigated and yields an optimized LEC performance. The large electrochemical stability window of DNA‐CTMA enables a stable device performance for a variety of emitters covering the complete visible spectral range, thus highlighting the universal character of this naturally sourced SPE.
Repurposed Drugs, Molecular Vaccines, Immune‐Modulators, and Nanotherapeutics to Treat and Prevent COVID‐19 Associated with SARS‐CoV‐2, a Deadly Nanovector
Authors: Dube Taru , Ghosh Amrito , Mishra Jibanananda , Kompella Uday B. , Panda Jiban Jyoti
Published: October 2020

The deadly pandemic, coronavirus disease 2019 (COVID‐19), caused due to the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has paralyzed the world. Although significant methodological advances have been made in the field of viral detection/diagnosis with 251 in vitro diagnostic tests receiving emergency use approval by the US‐FDA, little progress has been made in identifying curative or preventive therapies. This review discusses the current trends and potential future approaches for developing COVID‐19 therapeutics, including repurposed drugs, vaccine candidates, immune‐modulators, convalescent plasma therapy, and antiviral nanoparticles/nanovaccines/combinatorial nanotherapeutics to surmount the pandemic viral strain. Many potent therapeutic candidates emerging via drug‐repurposing could significantly reduce the cost and duration of anti‐COVID‐19 drug development. Gene/protein‐based vaccine candidates that could elicit both humoral and cell‐based immunity would be on the frontlines to prevent the disease. Many emerging nanotechnology‐based interventions will be critical in the fight against the deadly virus by facilitating early detection and enabling target oriented multidrug therapeutics. The therapeutic candidates discussed in this article include remdesivir, dexamethasone, hydroxychloroquine, favilavir, lopinavir/ritonavir, antibody therapeutics like gimsilumab and TJM2, anti‐viral nanoparticles, and nanoparticle‐based DNA and mRNA vaccines.
Porous Aromatic Framework with Tailored Binding Sites and Pore Sizes as a High‐Performance Hemoperfusion Adsorbent for Bilirubin Removal
Authors: Zhao Rui , Ma Tingting , Cui Fengchao , Tian Yuyang , Zhu Guangshan
Published: October 2020

Highly efficient removal of bilirubin from blood by hemoperfusion for liver failure therapy remains a challenge in the clinical field due to the low adsorption capacity and slow adsorption kinetics of currently used bilirubin adsorbents (e.g., activated carbon and ion‐exchange resin). Recently, porous aromatic frameworks (PAFs) with high surface areas, tunable structures, and remarkable stability provide numerous possibilities to obtain satisfying adsorbents. Here, a cationic PAF with more mesopores, named iPAF‐6, is successfully constructed via a de novo synthetic strategy for bilirubin removal. The prepared iPAF‐6 exhibits a record‐high adsorption capacity of 1249 mg g−1 and can adsorb bilirubin from 150 mg L−1 to normal concentration in just 5 min. Moreover, iPAF‐6 shows a removal efficiency of 96% toward bilirubin in the presence of 50 g L−1 bovine serum albumin. It is demonstrated that positively charged aromatic frameworks and large pore size make a significant contribution to its excellent adsorption ability. More notably, iPAF‐6/polyethersulfone composite fibers or beads are fabricated for practical hemoperfusion adsorption, which also show better removal performance than commercial adsorbents. This work can offer a new possibility for designing PAF‐based bilirubin adsorbents with an appealing application prospect.
Wine Consumption and Culture: A Cross‐Country Analysis
Authors: Agnoli Lara , Outreville J. François
Published: October 2020

The main objective of this article is to investigate how national culture and sociopolitical environment influence the level of wine consumption in a representative panel of countries. Culture is defined as the consumption practices related to economic, social, and cultural aspects and institutional factors. A single equation analysis is based on a cross section of countries representing 90% of wine consumption in the world for the period 2003–2017. In order to draw a final model explaining wine consumption through the cultural peculiarities of a country and to avoid multicollinearity among independent variables, a principal component analysis is performed and a random‐effects GLS regression model is applied to determine the set of cultural variables which are the most significant in affecting wine consumption.
Do people manage climate risk through long‐distance relationships?
Authors: Pisor Anne C. , Jones James Holland
Published: October 2020

Objectives

Long‐distance social relationships have been a feature of human evolutionary history; evidence from the paleoanthropological, archeological, and ethnographic records suggest that one function of these relationships is to manage the risk of resource shortfalls due to climate variability. We should expect long‐distance relationships to be especially important when shortfalls are chronic or temporally positively autocorrelated, as these are more likely to exhaust local adaptations for managing risk. Further, individuals who experience shortfalls not as rare shocks, but as patterned events, should be more likely to pay the costs of maintaining long‐distance relationships. We test these hypotheses in the context of two communities of Bolivian horticulturalists, where climate variability—especially precipitation variability—is relevant to production and access to long‐distance connections is improving.

Methods

Data on individuals' migration histories, social relationships, and other relevant variables were collected in 2017 (n = 119). Precipitation data were obtained from the US National Center for Atmospheric Research, allowing us to estimate participants' exposure to drought and excess precipitation.

Results

Exposure duration, proximity in time, and frequency did not predict having a greater number of long‐distance relationships. Males, extraverted individuals, and those who had traveled more did have more long‐distance relationships, however.

Conclusion

Another function of long‐distance relationships is to access resources that can never be obtained locally; ethnographic data suggest this is their primary function in rural Bolivia. We conclude by refining our predictions about the conditions under which long‐distance relationships are likely to help individuals manage the risks posed by climate variability.
A ketogenic drink improves cognition in mild cognitive impairment: Results of a 6‐month RCT
Authors: Fortier Mélanie , Castellano Christian‐Alexandre , St‐Pierre Valérie , Myette‐Côté Étienne , Langlois Francis , Roy Maggie , Morin Marie‐Christine , Bocti Christian , Fulop Tamas , Godin Jean‐Philippe , Delannoy Carla , Cuenoud Bernard , Cunnane Stephen C.
Published: October 2020

Introduction

Counteracting impaired brain glucose metabolism with ketones may improve cognition in mild cognitive impairment (MCI).

Methods

Cognition, plasma ketone response, and metabolic profile were assessed before and 6 months after supplementation with a ketogenic drink containing medium chain triglyceride (ketogenic medium chain triglyceride [kMCT]; 15 g twice/day; n = 39) or placebo (n = 44).

Results

Free and cued recall (Trial 1; P = .047), verbal fluency (categories; P = .024), Boston Naming Test (total correct answers; P = .033), and the Trail‐Making Test (total errors; P = .017) improved significantly in the kMCT group compared to placebo (analysis of covariance; pre‐intervention score, sex, age, education, and apolipoprotein E4 as covariates). Some cognitive outcomes also correlated positively with plasma ketones. Plasma metabolic profile and ketone response were unchanged.

Conclusions

This kMCT drink improved cognitive outcomes in MCI, at least in part by increasing blood ketone level. These data support further assessment of MCI progression to Alzheimer's disease.
Bunsen, der Geochemiker: isländische Vulkane, Geysirtheorie sowie Gas‐, Gesteins‐ und Mineralienanalysen
Authors: Wentrup Curt
Published: October 2020

Nach der großen Eruption des isländischen Vulkans Hekla 1845–1846 wurde Bunsen von König Christian VIII. von Dänemark und Island eingeladen, an einer geochemischen Expedition nach Island zusammen mit dem Geologen Sartorius von Waltershausen und dem Physiologen Carl Bergmann (Göttingen) teilzunehmen. Der französische Mineraloge Des Cloizeaux ging unabhängig nach Island, wo er sich der Expedition anschloss. Das von Bunsen entwickelte Eudiometer war für seine präzisen Bestimmungen von vulkanischen Gasen und der Zusammensetzung von Mischungen maßgebend. Aufgrund seiner zahlreichen Gesteins‐ und Mineralienanalysen teilte er vulkanische Gesteine in zwei fundamentale Typen ein, den mehr kieselsäurereichen (heutzutage felsisch genannt) und den weniger kieselsäurereichen, mehr basischen (heute mafisch), in Übereinstimmung mit Des Cloizeaux und dem dänischen Naturwissenschaftler J. C. Schythe. Bunsen formulierte auch den richtigen Mechanismus des Geysirphänomens und half, die Theorie von einer Verbindung zwischen Vulkanen, Geysiren und der See zu wiederlegen. Er geriet in heftige Auseinandersetzungen mit von Waltershausen über die Mechanismen der Bildung von Ammoniumchlorid und von vulkanischen Gesteinen sowie deren chemischer Zusammensetzung. Er zeigte sich als Erz‐Experimentator und vehementer Gegner von Hypothesen aller Art, weshalb er auch die neuen chemischen Theorien, z. B. die von Dumas und Kekulé, ablehnte.
Total Synthesis of the Diterpene Waihoensene
Authors: Rosenbaum Lisa‐Catherine , Häfner Maximilian , Gaich Tanja
Published: October 2020

A racemic and scalable enantioselective total synthesis of (+)‐waihoensene was accomplished. (+)‐Waihoensene belongs to the diterpene natural product family, and it features an angular triquinane substructure motif. Its tetracyclic [6.5.5.5]backbone is all‐cis‐fused, containing six contiguous stereocenters, four of which are quaternary. These structural features were efficiently installed by means of a diastereoselective radical cyclization, followed by an intramolecular Pauson–Khand reaction, a diastereoselective α‐alkylation, and a diastereoselective 1,4‐addition reaction. Enantioselectivity was introduced at an early stage, by an asymmetric palladium catalyzed decarboxylative allylation reaction on gram scale.
Insight into the Transition‐Metal Hydroxide Cover Layer for Enhancing Photoelectrochemical Water Oxidation
Authors: Ning Xingming , Du Peiyao , Han Zhengang , Chen Jing , Lu Xiaoquan
Published: October 2020

Depositing a transition‐metal hydroxide (TMH) layer on a photoanode has been demonstrated to enhance photoelectrochemical (PEC) water oxidation. However, the controversial understanding for the improvement origin remains a key challenge to unlock the PEC performance. Herein, by taking BiVO4/iron‐nickel hydroxide (BVO/FxN4−x‐H) as a prototype, we decoupled the PEC process into two processes including charge transfer and surface catalytic reaction. The kinetic information at the BVO/FxN4−x‐H and FxN4−x‐H/electrolyte interfaces was systematically evaluated by employing scanning photoelectrochemical microscopy (SPECM), intensity modulated photocurrent spectroscopy (IMPS) and oxygen evolution reaction (OER) model. It was found that FxN4−x‐H acts as a charge transporter rather than a sole electrocatalyst. PEC performance improvement is mainly ascribed to the efficient suppression of charge recombination by fast hole transfer kinetics at BVO/FxN4−x‐H interface.
An Iminophosphonamido‐Chlorosilylene as a Strong σ‐Donating NHSi Ligand: Synthesis and Coordination Chemistry
Authors: Takahashi Shintaro , Sekiguchi Jueri , Ishii Akihiko , Nakata Norio
Published: October 2020

TheN‐heterocyclic silylene (NHSi) [Ph2P(tBuN)2]SiCl (1), supported by an iminophosphonamide ligand, was obtained from the dehydrochlorination of [Ph2P(tBuN)2]SiHCl2(2) with LiN(SiMe3)2. NHSi1contains an extremely high‐energy HOMO level and consequently displays unique coordination behavior toward RhIcomplexes. When1was treated with 1/4 of an equivalent of [RhCl(cod)]2(cod=1,5‐cyclooctadiene), the 14‐electron Y‐shaped bis(chlorosilylene) RhIcomplex5was obtained as dark purple crystals. The reaction of1with 1/6 of an equivalent of [RhCl(cod)]2yielded the cationic tris(silylene)‐RhIcomplex [6]+⋅Cl−as red crystals, wherein a two‐coordinated silylene ligand engages in a Si=Rh double bond. A structural analysis of5and [6]+⋅Cl−revealed that the central rhodium atoms adopt trigonal and square‐planar coordination geometries, respectively, with considerably shortened Si‐Rh bonds [5: 2.1605(5) Å; [6]+: 2.133(1) Å].
Surface Coordination of Multiple Ligands Endows N‐Heterocyclic Carbene‐Stabilized Gold Nanoclusters with High Robustness and Surface Reactivity
Authors: Shen Hui , Xu Zhen , Hazer Maryam Sabooni Asre , Wu Qingyuan , Peng Jian , Qin Ruixuan , Malola Sami , Teo Boon K. , Häkkinen Hannu , Zheng Nanfeng
Published: October 2020

Deciphering the molecular pictures of the multi‐component and non‐periodic organic‐inorganic interlayer is a grand technical challenge. Here we show that the atomic arrangement of hybrid surface ligands on metal nanoparticles can be precisely quantified through comprehensive characterization of a novel gold cluster, Au44(iPr2‐bimy)9(PA)6Br8 (1), which features three types of ligands, namely, carbene (1,3‐diisopropylbenzimidazolin‐2‐ylidene, iPr2‐bimy), alkynyl (phenylacetylide, PA), and halide (Br), respectively. The delicately balanced stereochemical effects and bonding capabilities of the three ligands give rise to peculiar geometrical and electronic structures. Remarkably, despite its complex and highly distorted surface structure, cluster 1 exhibits unusual catalytic properties and yet it is highly stable, both chemically and thermally. Moreover, rich reactive sites on the cluster surface raise the prospect of bio‐compatibility (as it can be functionalized to yield water‐soluble derivatives) and bio‐applications.
Adrenergic Modulation With Photochromic Ligands
Authors: Prischich Davia , Gomila Alexandre M. J. , Milla‐Navarro Santiago , Sangüesa Gemma , Diez‐Alarcia Rebeca , Preda Beatrice , Matera Carlo , Batlle Montserrat , Ramírez Laura , Giralt Ernest , Hernando Jordi , Guasch Eduard , Meana J. Javier , de la Villa Pedro , Gorostiza Pau
Published: October 2020

Adrenoceptors are ubiquitous and mediate important autonomic functions as well as modulating arousal, cognition, and pain on a central level. Understanding these physiological processes and their underlying neural circuits requires manipulating adrenergic neurotransmission with high spatio‐temporal precision. Here we present a first generation of photochromic ligands (adrenoswitches) obtained via azologization of a class of cyclic amidines related to the known ligand clonidine. Their pharmacology, photochromism, bioavailability, and lack of toxicity allow for broad biological applications, as demonstrated by controlling locomotion in zebrafish and pupillary responses in mice.
Discovery and Supramolecular Interactions of Neutral Palladium‐Oxo Clusters Pd16and Pd24
Authors: Bhattacharya Saurav , Basu Uttara , Haouas Mohamed , Su Pei , Espenship Michael Forrester , Wang Fei , Solé‐Daura Albert , Taffa Dereje H. , Wark Michael , Poblet Josep M. , Laskin Julia , Cadot Emmanuel , Kortz Ulrich
Published: October 2020

We report on the synthesis, structure, and physicochemical characterization of the first three examples of neutral palladium‐oxo clusters (POCs). The 16‐palladium(II)‐oxo cluster [Pd16O24(OH)8((CH3)2As)8] (Pd16) comprises a cyclic palladium‐oxo unit capped by eight dimethylarsinate groups. The chloro‐derivative [Pd16Na2O26(OH)3 Cl3 ((CH3)2 As)8] (Pd16Cl) was also prepared, which forms a highly stable 3D supramolecular lattice via strong intermolecular interactions. The 24‐palladium(II)‐oxo cluster [Pd24O44(OH)8((CH3)2As)16] (Pd24) can be considered as a bicapped derivative ofPd16with a tetra‐palladium‐oxo unit grafted on either side. The three compounds were fully characterized 1) in the solid state by single‐crystal and powder XRD, IR, TGA, and solid‐state1H and13C NMR spectroscopy, 2) in solution by1H,13C NMR and1H DOSY spectroscopic methods, and 3) in the gas phase by electrospray ionization mass spectrometry (ESI‐MS).
Nickel‐ and Palladium‐Catalyzed Cross‐Coupling Reactions of Organostibines with Organoboronic Acids
Authors: Zhang Dejiang , Le Liyuan , Qiu Renhua , Wong Wai‐Yeung , Kambe Nobuaki
Published: October 2020

A strategy for the formation of antimony‐carbon bond was developed by nickel‐catalyzed cross‐coupling of halostibines. This method has been applied to the synthesis of various triaryl‐ and diarylalkylstibines from the corresponding cyclic and acyclic halostibines. This protocol showed a wide substrate scope (72 examples) and was compatible to a wide range of functional groups such as aldehyde, ketone, alkene, alkyne, haloarenes (F, Cl, Br, I), and heteroarenes. A successful synthesis of arylated stibine 3 a in a scale of 34.77 g demonstrates high synthetic potential of this transformation. The formed stibines (R3Sb) were then used for the palladium‐catalyzed carbon–carbon bond forming reaction with aryl boronic acids [R−B(OH)2], giving biaryls with high selectivity, even the structures of two organomoieties (R and R′) are very similar. Plausible catalytic pathways were proposed based on control experiments.
Synergy between Metallic and Oxidized Pt Sites Unravelled during Room Temperature CO Oxidation on Pt/Ceria
Authors: Meunier Frederic C. , Cardenas Luis , Kaper Helena , Šmíd Břetislav , Vorokhta Mykhailo , Grosjean Rémi , Aubert Daniel , Dembélé Kassiogé , Lunkenbein Thomas
Published: October 2020

Pt‐based materials are widely used as heterogeneous catalysts, in particular for pollutant removal applications. The state of Pt has often been proposed to differ depending on experimental conditions, for example, metallic Pt poisoned with CO being present at lower temperature before light‐off, while an oxidized Pt surface prevails above light‐off temperature. In stark contrast to all previous reports, we show herein that both metallic and oxidized Pt are present in similar proportions under reaction conditions at the surface of ca. 1 nm nanoparticles showing high activity at 30 °C. The simultaneous presence of metallic and oxidized Pt enables a synergy between these phases. The main role of the metallic Pt phase is to provide strong adsorption sites for CO, while that of oxidized Pt supposedly supplies reactive oxygen. Our results emphasize the complex dual oxidic–metallic nature of supported Pt catalysts and platinum's evolving nature under reaction conditions.
Exploiting Ru‐Induced Lattice Strain in CoRu Nanoalloys for Robust Bifunctional Hydrogen Production
Authors: Li Weidong , Zhao Yunxuan , Liu Yuan , Sun Mingzi , Waterhouse Geoffrey I. N. , Huang Bolong , Zhang Kan , Zhang Tierui , Lu Siyu
Published: October 2020

Designing bifunctional catalysts capable of driving the electrochemical hydrogen evolution reaction (HER) and also H2 evolution via the hydrolysis of hydrogen storage materials such as ammonia borane (AB) is of considerable practical importance for future hydrogen economies. Herein, we systematically examined the effect of tensile lattice strain in CoRu nanoalloys supported on carbon quantum dots (CoRu/CQDs) on hydrogen generation by HER and AB hydrolysis. By varying the Ru content, the lattice parameters and Ru‐induced lattice strain in the CoRu nanoalloys could be tuned. The CoRu0.5/CQDs catalyst with an ultra‐low Ru content (1.33 wt.%) exhibited excellent catalytic activity for HER (η=18 mV at 10 mA cm−2 in 1 M KOH) and extraordinary activity for the hydrolysis of AB with a turnover frequency of 3255.4 mol
 mol−1(Ru) min−1 or 814.7 mol
 mol−1(cat) min−1 at 298 K, respectively, representing one of the best activities yet reported for AB hydrolysis over a ruthenium alloy catalyst. Moreover, the CoRu0.5/CQDs catalyst displayed excellent stability during each reaction, including seven alternating cycles of HER and AB hydrolysis. Theoretical calculations revealed that the remarkable catalytic performance of CoRu0.5/CQDs resulted from the optimal alloy electronic structure realized by incorporating small amounts of Ru, which enabled fast interfacial electron transfer to intermediates, thus benefitting H2 evolution kinetics. Results support the development of new and improved catalysts HER and AB hydrolysis.
Multiple imputation methods for handling missing values in longitudinal studies with sampling weights: Comparison of methods implemented in Stata
Authors: De Silva Anurika P. , De Livera Alysha M. , Lee Katherine J. , Moreno‐Betancur Margarita , Simpson Julie A.
Published: October 2020

Many analyses of longitudinal cohorts require incorporating sampling weights to account for unequal sampling probabilities of participants, as well as the use of multiple imputation (MI) for dealing with missing data. However, there is no guidance on how MI and sampling weights should be implemented together. We simulated a target population based on the Australian Bureau of Statistics Estimated Resident Population and drew 1000 random samples dependent on three design variables to mimic the Longitudinal Study of Australian Children. The target analysis was the weighted prevalence of overweight/obesity over childhood. We evaluated the performance of several MI approaches available in Stata, based on multivariate normal imputation (MVNI), fully conditional specification (FCS) and twofold FCS: a weighted imputation model, imputing missing data separately for each quintile sampling weight grouping, including the design stratum indicator in the imputation model, and using sampling weights as a covariate in the imputation model. Approaches based on available cases and inverse probability weighting (IPW), with time‐varying weights, were also compared. We observed severe issues of convergence with FCS and twofold FCS. All MVNI‐based approaches performed similarly, producing minimal bias and nominal coverage, except for when imputation was conducted separately for each quintile sampling weight group. IPW performed equally as well as MVNI‐based approaches in terms of bias, however, was less precise. In similar longitudinal studies, we recommend using MVNI with the design stratum as a covariate in the imputation model. If this is unknown, including the sampling weight as a covariate is an appropriate alternative.