bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating alternative hypotheses to explain the downward trend in the indices of the COVID-19 pandemic death rate
Authors: Shinde Sonali , Ranade Pratima , Watve Milind
Published: April 2021

Background

In the ongoing Covid-19 pandemic, in the global data on the case fatality ratio (CFR) and other indices reflecting death rate, there is a consistent downward trend from mid-April to mid-November. The downward trend can be an illusion caused by biases and limitations of data or it could faithfully reflect a declining death rate. A variety of explanations for this trend are possible, but a systematic analysis of the testable predictions of the alternative hypotheses has not yet been attempted.

Methodology

We state six testable alternative hypotheses, analyze their testable predictions using public domain data and evaluate their relative contributions to the downward trend.

Results

We show that a decline in the death rate is real; changing age structure of the infected population and evolution of the virus towards reduced virulence are the most supported hypotheses and together contribute to major part of the trend. The testable predictions from other explanations including altered testing efficiency, time lag, improved treatment protocols and herd immunity are not consistently supported, or do not appear to make a major contribution to this trend although they may influence some other patterns of the epidemic.

Conclusion

The fatality of the infection showed a robust declining time trend between mid April to mid November. Changing age class of the infected and decreasing virulence of the pathogen were found to be the strongest contributors to the trend.
Anti-atherosclerotic vaccination against Porphyromonas gingivalis as a potential comparator of statin in mice
Authors: Ha Hyun-Su , Kim Tae Young , Han Soo Jung , Sung Hak-Joon , Seo Kyoung Yul , Ha Jong-Won
Published: April 2021

Background

Porphyromonas gingivalis (Pg) is an oral anaerobe which damages teeth and periodontal tissues. Its body infection is known to cause chronic inflammation, thereby inducing an early stage of atherosclerosis through humoral immune actions. Hence, vaccination by immunizing the proteins of P. gingivalis (Pg) post sonication with heating may prevent atherosclerosis. This study aimed to compare the effect of its vaccination with statin, which effectively prevents atherosclerosis by lowering lipids.

Methods

The vaccine was produced by sonicating P. gingivalis through heating, and a total of 32 male APOE-/-mice (8-week old) were subjected Western diet for 8 weeks, in order to induce atherosclerosis in a physiological manner. Then, the mice were grouped to undergo four treatment conditions (i.e., no treatment, pitavastatin, vaccine, or pitavastatin with vaccine). Vaccination was conducted through nasal immunization and confirmed by a Pg-specific humoral immune reaction. Then, half of the mice in each group were orally injected with P. gingivalis for the next 5 weeks while the other half remained uninfected, generating a total of eight groups (n = 4/group). The mice were sacrificed at 3 weeks after the last injection. After harvesting the aorta, Oil Red O staining of en face was conducted with imaging and image analysis, and plaque formation was quantitatively determined.

Results

Compared to no treatment, the vaccination through nasal immunization significantly reduced the atherosclerotic plaque sizes in APOE -/- mice under Western diet to the comparable level of statin group. When both vaccine and statin were used, no clear synergistic effect was observed as opposed to expectation.

Conclusions

This study revealed that nasal immunization of heat shock P. gingivalis has a significant impact on the prevention of arteriosclerosis and acts as a potential comparator of statin.
Демократия в цифровом тумане, "Энергия: экономика, техника, экология"
Authors: ВАГАНОВ А.Г.
Published: April 2021

С1 января 2021 года в Китае вступила в полномасштабную эксплуатацию национальная так называемая “система социального кредита” (ССК). В стране принят первый в истории КНР Гражданский кодекс. Он узаконивает ССК. Подготовка к введению системы длились довольно долго, с 2010 года. Что это такое – ССК, лучше всего пояснить на конкретном примере “модельного” китайского города Жунчэнь.
Forecast Methods and Periodic Review Inventory Model for Supply Planning to Reduce Food Waste
Authors: Ceballos-Palomares Leslie-Noelia , Nava-Jiménez Andrés-Benjamín , Caballero-Morales Santiago-Omar , Cano-Olivos Patricia
Published: April 2021

Food waste is an important economic and resource problem in all countries around the world.  Particularly, the restaurant sector highly contributes to food waste and limited efforts or studies have been performed to overcome this problem. In this context, the present study addresses an alternative to improve the supply planning for perishable products in the restaurant sector through the application of specific forecasting methods and a stochastic inventory control model. For this purpose, a real enterprise within this economic sector was considered. Our findings support that monthly forecasts can be more appropriate for accurate demand estimation and supply planning of perishable products, which is important to reduce unnecessary products. Also, the periodic review inventory control model can lead to a more appropriate supply scheme to reduce the waste of surplus food. These findings and the proposed techniques can be used for other economic entities to reduce product waste due to poor supply planning.
Classification of Level of Rice Pest Incidence Based on Weather Information
Authors: Jinubala V. , Jeyakumar P.
Published: April 2021

Aims: To classify the rice pest data based on the weather attributes using a machine learning approach, a decision tree classifier, and to validate the performance results with other existing techniques through comparison.

Design: Rice pest classification using C5.0 algorithm

Methodology: We collected rice pest data from the crop fields of various regions in the state of Maharashtra of India. The dataset contains the name of the region (Taluk), period (week), pest data, temperature, rainfall, and relative humidity. The data is collected from 39 taluks within four districts in different weeks of the year of 2013-2014. The weather information plays a vital role in this rice pest data analysis, because based on the weather, pest infestation varies in all the regions. The pests considered in this research are Yellow Stem borer, Gall midge, Leaf folder, and Planthopper. The collected dataset is given as input to the classifier, where 75% of data from the dataset is used for training, and 25% of data are used for testing the classifier.

Results: The proposed C5.0 algorithm performed better in the classification of rice pest dataset based on weather attributes. The C5.0 algorithm achieved 88.99% accuracy, 78.81% sensitivity, and 89.11% specificity, which are higher in performance when compared with other techniques. Compared with the other different methods, the C5.0 algorithm achieved 1.3 to 8.5% improved accuracy, 2.4 to 9% improved sensitivity, and 0.8 to 7.8% improved specificity.

Conclusion: Early detection of pest and pest based diseases is an essential process to avoid major crop losses. The proposed classification model is designed to classify the level of pest infestations based on weather attributes, as level of infestations caused by the rice pest varies based on weather conditions. The C5.0 algorithm classified the rice pest data based on the weather attributes in the dataset.
Bioethanol Production from an Underutilized Plant, Calabash (Crescentia Cujete) Using Co-Culture of Saccharomyces Cerevisiae and Cronobacter Malonaticus
Authors: Nwogwugwu N. U. , Abu G.O. , Akaranta O.
Published: April 2021

Response surface methodology (RSM) model was used to optimize ethanol production from calabash (Crescentia cujete) pulp juice using co-culture of Saccharomyces cerevisiae and Cronobacter malonaticus. The calabash pulp was squeezed with muslin cloth, and vacuum filtered to clear solution before use. The clear juice was tested for reducing sugars using the Dinitrosalicylic acid (DNS) method. Twenty three runs (23), including 3 controls, of the fermentation were conducted at varying temperatures, pH, and volumes of inoculum. The process parameters (input variables): volumes of inoculum, temperature, and pH were subjected to response surface model, using the Central composite design (CCD). Fermentation was done in conical flasks covered with cotton wool and foil in a stationary incubator for four days (96 hours). Active co-culture of Saccharomyces cerevisiae and Cronobacter malonaticus was used, with inoculum developed using Marcfaland’s method. Samples were collected every 24 hours, centrifuged, filtered and analyzed for measurement of the output variables: reducing sugar, cell density and ethanol concentration. The concentration of reducing sugars from Calabash pulp was 3.2 mg/ml. Results obtained also revealed that the fermentation can take place on a wide range of temperature; 29-31.60C . The optimal pH range for performance of the co-culture for the fermentation process was pH range 7.9- 8.0. The optimum volume of inoculum was 5.5%v/v (ie 5.5 ml in 94.5ml juice). The optimized process using the RSM model gave 6.97% v/v bioethanol at 29oC and pH 7.9. The bioethanol yield from Calabash substrate is reasonable with co-culture considering the concentration of reducing sugars obtained from the juice and the duration of the fermentation.
Prevalence of Rubella Immunity among Women Seeking Antenatal Care in a Tertiary Institution, South-South, Nigeria
Authors: Egbagba J. E. , Abdu A. O. , Osegi N. , Amadi S. C. , Alex-Wele M. A. , Oboro I. L.
Published: April 2021

Aims: To determine rubella sero-prevalence (IgG, IgM) and to describe its relation to socio-demographic data among pregnant women in a tertiary institution in Yenagoa, Bayelsa state, South-South, Nigeria.

Study Design:  This was a descriptive cross sectional study.

Place and Duration of Study: Department of Obstetrics and Gynaecology, Federal Medical Centre in Yenegoa, Bayelsa State, in South-South Nigeria between May 2020 and August 2020.

Methodology: We included 398 women at various stages of pregnancy. An interviewer administered questionnaire was used to obtain socio demographic data. Ten ml of venous blood was then collected for serological assays.  Analyses of samples were done using an in-vitro on-site rubella IgG/IgM rapid diagnostic assay. P value were kept at 0.05.

Results: A total of 209 (53.0%) of the 398 women had a positive IgG antibodies. None (0.0%) of the women had positive IgM antibodies. There were no significant associations between respondents socio-demographic characteristics and rubella immunity as the probability values observed were greater than 0.05 (p>0.05).

Conclusion: Our study shows a moderately high sero-prevalence of IgG antibodies amongst the participants studied. This indicates that rubella infection is endemic in Nigeria and requires further surveillance and control.
Medicinal Potentials of Ocimum gratissimum Linn Leaf Extract against Lead Acetate Disruptions in Rat Hippocampus and Electrolyte Concentration
Authors: Isaac Ubi Essien
Published: April 2021

The present study determined the effect of Ocimum gratissimun Linn. leaves aqueous extract on lead-acetate alterations in the hippocampus and serum biochemical concentration of sodium (Na+) and potassium (K+) ions in animal models. Twenty male and female albino rats weighing around 155 g were randomly distributed to four groups, (n=5 each). Group A served as control, B received 500 mg/kg body weight of O. gratissimum leaf extract, C was administered 150 mg/kg of lead acetate, and group D was given both lead acetate and the named leaf extract at doses of 150 mg/kg and 500 mg/kg respectively. Treatments were given once daily via gavage and lasted 15 days while the animals had access to feed and water ad libitum. The rats were euthanized on the 16th day by cervical dislocation; the cranial cavity was carefully exposed and the brain dissected to excise tissue specimens from the hippocampus for histological studies. Blood samples were also collected through cardiac puncture and then centrifuged to obtain serum used for the biochemical parameter. The one-way Analysis of Variance was the statistical tool used to evaluate the differences in concentration of the electrolytes, and data was expressed as means ± SD, while P< 0.05 was taken as a significant value. The results showed the extract to have a mitigating effect by alleviating lead-acetate induced histopathological distortions of the hippocampal pyramidal neurons and by counteracting the neurochemical alterations in brain electrolyte ion. The findings of this research therefore indicate that the leaf aqueous extract of O. gratissimum has anti-toxic properties and may therefore be explored by pharmaceuticals in search of alternative treatment for lead poisoning.
COVID-19's Economic Impact on the Global Health Systems: Time to Respond to New Realities
Authors: Almalki Ziyad S.
Published: April 2021

Around six months have passed since the emergence of an ongoing coronavirus-related health pandemic. In resource-limited countries, healthcare systems with fewer options for intervention are likely to face more economic difficulties. The goal of this review is to summarize and explore the cost and economic effect of COVID-19 on global health systems. The study starts with a crisis synopsis and costs of COVID-19 treatment, then discusses how health has been affected and approaches to alleviating the burden while at the same time limiting an inevitable income loss.

Even if it is difficult to project COVID-19 spending because there are many uncertainties about the disease and its future course, various reports have quantified the amounts spent on direct COVID-19 treatment in different countries. The healthcare sector around the world has faced catastrophic financial challenges and experienced the largest global recession in history. Most governments in the world cannot avoid the devastating economic impact of COVID-19 on the healthcare sector, but they can try to avert the worst effects. With the spread of the coronavirus, the healthcare systems are facing a financial crisis as a result of actions that countries have adopted to mitigate the spread of the virus. Therefore, it is crucial to act swiftly and in meaningful ways to minimize the fallout from this shock.
Phytonutrients and Antimicrobial Activities of Methanolic Extract from Hafr Al-Batin Truffles
Authors: Al-Mazaideh Ghassab M. , Al-Swailmi Farhan K.
Published: April 2021

The desert truffle is a wild mushroom, also referred to as Kamah or Fagaa. Kamah is a rich source of polysaccharides that have medicinal, antitumoral, antibacterial, and immune-stimulant effects. Studies of hypogeous fungi, especially desert truffles, have recently entered traditional studies of epigeous higher Basidiomycetes. Based on the tasty desert truffle Kamah obtained from Hafr Al-Batin Governorate, Saudi Arabia, as a source of potential antimicrobial agents with both the aim of obtaining novel agents toward bacteria and Fungi of clinical significance. We specifically tested the antibacterial and antifungal efficacy of methanol extracts of Kamah against the Gram-negative bacterial pathogens reference strains E. coli ATCC® 8739, P. Aeruginosa ATCC®9027, S. aureus ATCC®6538, Enterococci NCTC®775 and opportunistic fungus C. albicans ATCC®1231.The extract had MIC (minimum inhibitory concentrations) varying from 100 g/ml to 500 g/ml against the pathogens examined. The LC-QTOF-MS (liquid chromatography coupled to quadrupole time of flight mass spectrometry) phytoconstituents assay chromatogram indicated that the methanol extracts of Kamah comprises 264 with retention periods varying from 1.04 to 18.86, which were categorized as unsaturated and saturated natural ingredients sch as aromatic compounds, carboxylic acids, oxygenated hydrocarbons, fatty acids, amino acids, and vitamins).The main compounds were discovered to be 21 with peak areas larger than 2X10-5 and retention periods varying from 2.3 to 9.13.The main known substances with the maximum peaks were adenosine (11.724), phenylalanine (7.711), phenprobamate (7.711), and 5-hydroxytryptophan (5.711). Such preliminary findings, we assume, are encouraging in terms of obtaining a beneficial antibiotic substitute to battle antibiotic-resistant pathogens especially eye infections.
In vitro Antibacterial Activities of Honey Bee Extracts against Bacterial Isolates of Wound Infections
Authors: Ayodele O. A. , Aribisala J. O. , Oseni A. T. , Oladunmoye M. K.
Published: April 2021

Microorganisms most especially bacteria, continue to develop resistance against antimicrobial agents; hence novel sources of antibiotics are urgently needed to reduce this problem. This study was carried out to investigate the antibacterial activities of ethanolic, chloroform and aqueous extracts of Apis mellifera (honey bee) on isolates of wound infections. The isolates used in this study were procured from University of Ilorin Teaching Hospital (UITH) and confirmed using morphological and biochemical tests. The isolates used include; Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pnuemoniae, Proteus mirabilis and Proteus vulgaris. Honey bees were collected from an apitherapist at Sunshine honey and agro foods, Akure, Ondo State Nigeria. The whole insect was used for in vitro antibacterial evaluation of the isolates using agar well diffusion method. Ethanolic extract of A. mellifera had the highest inhibitory activity with mean zones of inhibition ranging from 7.40 mm to 21.67 mm, chloroform extracts had moderate inhibitory activity ranging from 4.63 mm to 10.03 mm while the aqueous extract had the least activity with zones of inhibition ranging from 3.00 mm to 6.30 mm. However, no antibacterial activity was observed against P. aeruginosa for all the extracts. It is concluded that extracts of honey bees most especially the ethanolic extract have antibacterial activity and thus could be a potential antibacterial agent against isolates of wound infections.
Antibacterial Properties of Different Husk Extracts of Cocos nucifera (Linn) in South Western Nigeria
Authors: Erinle B. A. , Ajayi A. O. , Osuntokun O. R.
Published: April 2021

Aim: The husk of coconut is part of drupe which have enormous benefit to humanity. However, what constitute the antimicrobial activity has not been fully investigated, and this is the basis for the study.

Materials and Methods:  The husk of coconut collected from local growers subjected to extraction process. The antimicrobial activity was investigated against bacterial strains; Staphylococcus aureus, Escherichia coli, Proteus mirabilis, Salmonella typhi, Enterococcus faecalis, Klebsiella aerogene, Pseudomonas aeruginosa, Streptococcus pneumoniae by agar well diffusion method using n-hexane, ethanol and distilled water as solvents.

Results: Aqueous extracts of coconut showed inhibitory effect against the different tested bacteria organisms with variable zone of inhibition range 7 to 22 mm.

Conclusion: The aqueous extracts of coconut exhibited the presence of   highly effective   bioactive ingredients in these extracts. This can be identified, assay and characterize to be used as synthetic drug which would be available for treatment of bacterial infection.
Extremum seeking‐based observer design for reduced order models of coupled thermal and fluid systems
Authors: Koga Shumon , Benosman Mouhacine , Borggaard Jeff
Published: April 2021

We present an extremum seeking (ES)‐based robust observer design for thermal‐fluid systems, pursuing an application to efficient energy management in buildings. The model is originally described by Boussinesq equations which is given by a system of two coupled partial differential equations (PDEs) for the velocity field and temperature profile constrained to incompressible flow. Using proper orthogonal decomposition, the PDEs are reduced to a set of nonlinear ordinary differential equations. Given a set of temperature and velocity point measurements, a nonlinear state observer is designed to reconstruct the entire state under the error of initial states, and model parametric uncertainties. We prove that the closed loop system for the observer error state satisfies an estimate of L2 norm in a sense of locally input‐to‐state stability with respect to parameter uncertainties. Moreover, the uncertain parameters estimate used in the designed observer are optimized through iterations of a data‐driven ES algorithm. Numerical simulation of a two‐dimensional Boussinesq PDE illustrates the performance of the proposed adaptive estimation method.
Polymer Dielectrics with Simultaneous Ultrahigh Energy Density and Low Loss
Authors: Zhang Min , Li Bo , Wang Jian‐Jun , Huang Hou‐Bing , Zhang Lin , Chen Long‐Qing
Published: April 2021

Polymer dielectrics are highly desirable in capacitor applications due to their low cost, high breakdown strength, and unique self‐healing capability. However, existing polymer dielectrics suffer from either a low energy density or a high dielectric loss, thereby hindering the development of compact, efficient, and reliable power electronics. Here, a novel type of polymer dielectrics simultaneously exhibiting an extraordinarily high recoverable energy density of 35 J cm−3 and a low dielectric loss is reported. It is synthesized by grafting zwitterions onto the short side chains of a poly(4‐methyl‐1‐pentene) (PMP)‐based copolymer, which increases its dielectric constant from ≈2.2 to ≈5.2 and significantly enhances its breakdown strength from ≈700 MV m−1 to ≈1300 MV m−1 while maintaining its low dielectric loss of <0.002 and high charge–discharge efficiency of >90%. Based on a combination of the phase‐field method description of mesoscale structures, Maxwell equations, and theoretical analysis, it is demonstrated that the outstanding combination of high energy density and low dielectric loss of zwitterions‐grafted copolymers is attributed to the covalent‐bonding restricted ion polarization and the strong charge trapping by the zwitterions. This work represents a new strategy in polymer dielectrics for achieving simultaneous high energy density and low dielectric loss.
Top‐Level Design Strategy to Construct an Advanced High‐Entropy Co–Cu–Fe–Mo (Oxy)Hydroxide Electrocatalyst for the Oxygen Evolution Reaction
Authors: Zhang Lingjie , Cai Weiwei , Bao Ningzhong
Published: April 2021

High‐entropy materials are new‐generation electrocatalysts for water splitting due to their excellent reactivity and highly tailorable electrochemical properties. Herein, a powerful top‐level design strategy is reported to guide and design advanced high‐entropy electrocatalysts by establishing reaction models (e.g., reaction energy barrier, conductivity, adsorption geometries for intermediates, and rate‐determining step) to predict performance with the help of density functional theory (DFT) calculations. Accordingly, novel high‐entropy Co–Cu–Fe–Mo (oxy)hydroxide electrocatalysts are fabricated by a new low‐temperature electrochemical reconstruction method and their oxygen evolution reaction (OER) properties are thoroughly characterized. These as‐prepared quaternary metallic (oxy)hydroxides present much better OER performance than ternary Co–Cu–Mo (oxy)hydroxide, Co–Fe–Mo (oxy)hydroxide, and other counterparts, and are demonstrated with a low overpotential of 199 mV at a current density of 10 mA cm−2 and a 48.8 mV dec−1 Tafel slope in 1 m KOH and excellent stability without decay over 72 h. The performance enhancement mechanism is also unraveled by synchrotron radiation. The work verifies the usefulness of high‐entropy design and the great synergistic effect on OER performance by the incorporation of four elements, and also provides a new method for the construction of advanced high‐entropy materials for energy conversion and storage.
Orthogonal Images Concealed Within a Responsive 6‐Dimensional Hypersurface
Authors: Zholdassov Yerzhan S. , Valles Daniel J. , Uddin Samiha , Korpanty Joanna , Gianneschi Nathan C. , Braunschweig Adam B.
Published: April 2021

A photochemical printer, equipped with a digital micromirror device (DMD), leads to the rapid elucidation of the kinetics of the surface‐initiated atom‐transfer radical photopolymerization of N,N‐dimethylacrylamide (DMA) and N‐isopropylacrylamide (NIPAM) monomers. This effort reveals conditions where polymer brushes of identical heights can be grown from each monomer. With these data, hidden images are created that appear upon heating the substrate above the lower critical solution temperature (LCST) of polyNIPAM. By introducing a third monomer, methacryloxyethyl thiocarbamoyl rhodamine B, a second, orthogonal image appears upon UV‐irradiation. With these studies, it is shown how a new photochemical printer accelerates discovery, creates arbitrary patterns, and addresses long‐standing problems in brush polymer and surface chemistry. With this technology in hand a new method is demonstrated to encrypt data within hypersurfaces.
Retraction: Nanozyme‐Initiated In Situ Cascade Reactions for Self‐Amplified Biocatalytic Immunotherapy
Authors: Zhao Yajie , Xiao Xiao , Zou Man , Ding Binbin , Xiao Hui , Wang Meifang , Jiang Fan , Cheng Ziyong , Ma Ping'an , Lin Jun
Published: April 2021

Adv. Mater. 2021, 33, 2006363

DOI: 10.1002/adma.202006363

The above article, published online on December 6, 2020, in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief Jos Lenders, and Wiley‐VCH GmbH. The authors asked to retract this article as subsequent experiments revealed that the conclusions of this manuscript are invalid. The generation of hydroxyl radicals by the artificial cascade enzyme–drug conjugate could not be confirmed.
Improved Electrical, Thermal, and Thermoelectric Properties Through Sample‐to‐Sample Fluctuations in Near‐Percolation Threshold Composite Materials
Authors: Rösch Andres Georg , Giunta Fabian , Mallick Md. Mofasser , Franke Leonard , Gall André , Aghassi‐Hagmann Jasmin , Schmalian Jörg , Lemmer Uli
Published: April 2021

Effective medium theories (EMT) are powerful tools to calculate sample averaged thermoelectric material properties of composite materials. However, averaging over the heterogeneous spatial distribution of the phases can lead to incorrect estimates of the thermoelectric transport properties and the figure of merit ZT in compositions close to the percolation threshold. This is particularly true when the phases’ electronic properties are rather distinct leading to pronounced percolation effects. The authors propose an alternative model to calculate the thermoelectric properties of multi‐phased materials that are based on an expanded nodal analysis of random resistor networks (RRN). This method conserves the information about the morphology of the individual phases, allowing the study of the current paths through the phases and the influence of heterogeneous charge transport and cluster formation on the effective material properties of the composite. The authors show that in composites with strongly differing phases close to the percolation threshold the thermoelectric properties and the ZT value are always dominated exclusively by one phase or the other and never by an average of both. For these compositions, the individual samples display properties vastly different from EMT predictions and can be exploited for an increased thermoelectric performance.
Assessment of nitrogen diagnosis methods in sunflower
Authors: Tovar Hernandez Sergio , Diovisalvi Natalia , Carciochi Walter Daniel , Izquierdo Natalia , Sainz Rozas Hernán , Garcia Fernando , Reussi Calvo Nahuel I.
Published: April 2021

Nitrogen deficiency can severely limit sunflower (Helianthus annuus L.) grain yield and quality. Our objective was to evaluate N diagnosis methods based on: (a) pre‐plant soil nitrate‐nitrogen (NO3––N) test (PPSNT) and soil N mineralized in short‐term anaerobic incubation (Nan), (b) Greenness index (GI) and the normalized difference vegetation index (NDVI) measured at 6 (V6) and 12 (V12) leaves, and (c) grain nitrogen concentration (Nc). Seventeen experiments were carried out between 2010 and 2019 in Argentina, evaluating nine N rates (0, 30, 40, 60, 80, 90, 120, 150, and 160 kg N ha–1). The GI, NDVI, N sufficiency index and relative normalized difference vegetation index (NDVIr) were determined at V6 and V12 growth stages. On average, yield response to N was 492 kg ha–1 and Nc response was 0.25% in 9 and 11 responsive experiments, respectively. The inclusion of Nan improved the PPSNT diagnosis method. The critical N availability (PPSNT + fertilizer N) threshold was 115 kg N ha–1 for experiments with low Nan (<60 mg kg–1), and 90 kg N ha–1 for experiments with high Nan (>60 mg kg–1). The NDVIr at V12 allowed monitoring the crop N status with a 0.95 critical threshold. The Nc adequately diagnosed N deficiencies and the critical threshold was 2.26%. Also, Nc was predicted from the ratio between N availability and grain yield (R2 = .39). Our results would allow to better estimate N availability to recommend adequate N fertilizer rates for sunflower aiming to optimize grain yield and quality, and minimize the economic and environmental cost of fertilization.
Visible‐Light‐Induced Iminothiolation of Unactivated Alkenes
Authors: Wang Ding‐Xing , Cai Sai‐Hu , Liu Haidong , Ye Lu , Zhu Chuan , Feng Chao
Published: April 2021

An efficient visible‐light‐induced iminothiolation of unactivated alkenes has been developed for the rapid construction of pyrroline derivatives bearing a thioether moiety. In the presence of fac‐Ir(ppy)3 as photoredox catalyst, the acyl oximes were readily converted into iminyl radicals by single electron reduction under white LEDs irradiation, and the following radical cascading intramolecular cyclization and thioetherification would afford the functionalized pyrrolines with high efficiency. The mild reaction conditions including air atmosphere and ambient temperature allow for broad functional group tolerance. In addition, the good compatibility and practicality of this protocol is further highlighted by the employment of easily available thiophenols as the sulfur source for the thiolation process.
Scaffold‐Directed Face Selectivity Machine‐Learned from Vectors of Non‐covalent Interactions
Authors: Moskal Martyna , Beker Wiktor , Szymkuć Sara , Grzybowski Bartosz A.
Published: April 2021

This work describes a method to vectorize and Machine‐Learn, ML, non‐covalent interactions responsible for scaffold‐directed reactions important in synthetic chemistry. Models trained on this representation predict correct face of approach in ca. 90 % of Michael additions or Diels–Alder cycloadditions. These accuracies are significantly higher than those based on traditional ML descriptors, energetic calculations, or intuition of experienced synthetic chemists. Our results also emphasize the importance of ML models being provided with relevant mechanistic knowledge; without such knowledge, these models cannot easily “transfer‐learn” and extrapolate to previously unseen reaction mechanisms.
Efficient Intramolecular Charge‐Transfer Fluorophores Based on Substituted Triphenylphosphine Donors
Authors: Liu Zhang , Deng Chao , Su Liwu , Wang Dan , Jiang Yongshi , Tsuboi Taiju , Zhang Qisheng
Published: April 2021

Triphenylphosphine (TPP)‐based luminescent compounds are rarely investigated because of the low photoluminescence quantum yield (PLQY). Here, we demonstrate that introducing steric hindrance groups to the TPP moiety and separating the orbitals involved in the transition can drastically suppress the non‐radiative decay induced by structural distortion of TPP in the excited state. High PLQY up to 0.89 as well as thermally activated delayed fluorescence are observed from the intramolecular charge‐transfer (ICT) molecules with substituted TPP donors (sTPPs) in doped films. The red organic light‐emitting diodes employing these emitters achieve comparable external quantum efficiencies to the control device containing a classical phosphorescent dye, revealing the great potential of the ICT emitters based on electrochemically stable sTPPs.
Supercharging Prions via Amyloid‐Selective Lysine Acetylation
Authors: Baumer Katelyn M. , Cook Christopher D. , Zahler Collin T. , Beard Alexandra A. , Chen Zhijuan , Koone Jordan C. , Dashnaw Chad M. , Villacob Raul A. , Solouki Touradj , Wood John L. , Borchelt David R. , Shaw Bryan F.
Published: April 2021

Repulsive electrostatic forces between prion‐like proteins are a barrier against aggregation. In neuropharmacology, however, a prion's net charge (Z) is not a targeted parameter. Compounds that selectively boost prion Z remain unreported. Here, we synthesized compounds that amplified the negative charge of misfolded superoxide dismutase‐1 (SOD1) by acetylating lysine‐NH3+ in amyloid‐SOD1, without acetylating native‐SOD1. Compounds resembled a “ball and chain” mace: a rigid amyloid‐binding “handle” (benzothiazole, stilbene, or styrylpyridine); an aryl ester “ball”; and a triethylene glycol chain connecting ball to handle. At stoichiometric excess, compounds acetylated up to 9 of 11 lysine per misfolded subunit (ΔZfibril=−8100 per 103 subunits). Acetylated amyloid‐SOD1 seeded aggregation more slowly than unacetylated amyloid‐SOD1 in vitro and organotypic spinal cord (these effects were partially due to compound binding). Compounds exhibited reactivity with other amyloid and non‐amyloid proteins (e.g., fibrillar α‐synuclein was peracetylated; serum albumin was partially acetylated; carbonic anhydrase was largely unacetylated).
Synthesis, Electronic Structure, and Reactivity of a Planar Four‐Coordinate, Cobalt–Imido Complex
Authors: Park Yoonsu , Semproni Scott P. , Zhong Hongyu , Chirik Paul J.
Published: April 2021

A four‐coordinate cobalt–imido complex, (tBumPNP)Co=NMes (tBumPNP=modified PNP pincer ligand) has been synthesized from addition of 2,4,6‐trimethylphenylazide (Mes–N3) to the corresponding dinitrogen complex. The solid‐state structure determined by X‐ray diffraction established a rare, idealized planar geometry with a Co=N bond distance of 1.716(2) Å. Magnetic measurements revealed an S=1 ground state with CAS‐SCF calculations supporting radical character on the imide nitrogen. Thermolysis of the cobalt–imido compound induced selective insertion of the imido group into a Co−P bond and yielded a three‐coordinate cobalt complex with a distorted T‐shaped geometry. Transition state analysis conducted with DFT calculations established the thermodynamic stability of the P–N coupled product and provided insight into the exclusive selectivity.
Anion⋅⋅⋅Anion Coinage Bonds: The Case of Tetrachloridoaurate
Authors: Daolio Andrea , Pizzi Andrea , Terraneo Giancarlo , Ursini Maurizio , Frontera Antonio , Resnati Giuseppe
Published: April 2021

Interactions in crystalline tetrachloridoaurates of acetylcholine and dimethylpropiothetine are characterized by Au⋅⋅⋅Cl and Au⋅⋅⋅O short contacts. The former interactions assemble the AuCl4− units into supramolecular anionic polymers, while the latter interactions append the acetylcholine and propiothetine units to the polymer. The distorted octahedral geometry of the bonding pattern around the gold center is rationalized on the basis of the anisotropic distribution of the electron density, which enables gold to behave as an electrophile (π‐hole coinage‐bond donor). Computational studies prove that gold atoms in negatively charged species can function as acceptors of electron density. The attractive nature of the Au⋅⋅⋅Cl/O interactions described here complement the known aurophilic bonds involved in gold‐centered interactions.
Neither too Classic nor too Exotic: One‐Electron Na⋅B Bond in NaBH3− Cluster
Authors: Pino‐Rios Ricardo , Inostroza Diego , Tiznado William
Published: April 2021

It is here reported that the NaBH3− cluster exhibits a Na⋅B one‐electron bond, a well‐established type of electron‐deficient bonding in the literature. The topological analysis of the electron localization function, at the correlated level, reveals that Na−, when approaching the bonding distance, fairly distributes its valence electron pair between two lobes. One of these electrons is used to bond with BH3, which participates through its boron empty p‐orbital. Furthermore, the bonding situation of LiBH3−, KBH3−, MgBH3, and CaBH3 global minima structures are similar to that of NaBH3−, extending the family of these new one‐electron bond systems with biradicaloid character.
Synergistic Effect of Dielectric Property and Energy Transfer on Charge Separation in Non‐Fullerene‐Based Solar Cells
Authors: Li Pandeng , Fang Jin , Wang Yusheng , Manzhos Sergei , Cai Lei , Song Zheheng , Li Yajuan , Song Tao , Wang Xuechun , Guo Xia , Zhang Maojie , Ma Dongling , Sun Baoquan
Published: April 2021

In non‐fullerene‐based photovoltaic devices, it is unclear how excitons efficiently dissociate into charge carriers under small driving force. Here, we developed a modified method to estimate dielectric constants of PM6 donor and non‐fullerene acceptors. Surprisingly, most non‐fullerene acceptors and blend films showed higher dielectric constants. Moreover, they exhibited larger dielectric constants differences at the optical frequency. These results are likely bound to reduced exciton binding energy and bimolecular recombination. Besides, the overlap between the emission spectrum of donor and absorption spectra of non‐fullerene acceptors allowed the energy transfer from donor to acceptors. Hence, based on the synergistic effect of dielectric property and energy transfer resulting in efficient charge separation, our finding paves an alternative path to elucidate the physical working mechanism in non‐fullerene‐based photovoltaic devices.
Fabrication of active corrosion protection waterborne polyurethane coatings using cerium modified palygorskite nanocontainers
Authors: Ni Lingli , Li Shanshan , Liu Yongtao , Jiang Xiaowu , Cai Peng , Feng Liangdong , Zhang Shizhong , Gao Xiaoyan
Published: April 2021

The development of eco‐efficient and environmental friendly active anti‐corrosion coatings for metallic substrates represents a fundamental milestone in many engineering applications. Herein, a new type of active corrosion protection coating was successfully synthesized simply based on waterborne polyurethane (WPU) and nanocontainer of Ce3+ modified palygorskite (Ce‐PAL). Particularly, the nanocontainer of Ce‐PAL was achieved via a facile and green process by cation exchange in water. Inductively coupled plasma atomic emission spectrometry (ICP) revealed that Ce3+ had successfully incorporated into PAL nanofibers with a loading amount of 10.334 g/kg. The salt immersion test, electrochemical potentiodynamic measurements and electrochemical impedance spectroscopy (EIS) demonstrated that the incorporation of Ce‐PAL only with 2 wt% into WPU led to a significant improvement of their corrosion protection properties. Finally, according to the results of scanning electron microscopy with energy dispersive X‐ray spectroscopy, the active anti‐corrosion mechanism of Ce‐PAL/WPU coating was proposed.
Collagen quantification in the ventricular walls of the heart of the common marmoset (Callithrix jacchus)
Authors: Senos Rafael , Gomes Benedicto Hildebrando , Macedo del Rio do Valle Cristiane , del Rio do Valle Rodrigo , L Nayudu Penelope , Roberto‐Rodrigues Mauro , Bombonato Pedro Primo
Published: April 2021

The excellent adaptability of Callithrix jacchus to life in captivity presents advantages in comparison to other nonhuman primates that are used in experimental models for biomedical research, which explains the increasing scientific interest in investigating the anatomical characteristics of this species. Owing to the relative scarcity of publications on the descriptive morphology of the heart of C. jacchus, the aim of this study was to quantify the presence of collagen in the left and right ventricular myocardium using modified picrosirius red and acid fuchsine colorimetric assays. The myocardium of the right ventricle presented a higher percentage of collagen than that of the left ventricle. No sex‐related differences were observed between the groups. Interestingly, the absolute values of collagen were different depending on the method used for quantification (modified picrosirius red vs. acid fuchsine). The level of collagen quantification observed in the ventricular myocardium of C. jacchus was similar to that seen in other nonhuman primates traditionally used in experimental models of cardiac diseases.
Hybridization‐based design of novel anticholinesterase indanone–carbamates for Alzheimer's disease: Synthesis, biological evaluation, and docking studies
Authors: Shahrivar‐Gargari Mohammad , Hamzeh‐Mivehroud Maryam , Hemmati Salar , Mojarrad Javid S. , Tüylü Küçükkılınç Tuba , Ayazgök Beyza , Dastmalchi Siavoush
Published: April 2021

Inspired by the structures of donepezil and rivastigmine, a novel series of indanone–carbamate hybrids was synthesized using the pharmacophore hybridization‐based design strategy, and their biological activities toward acetylcholinesterase (AChE) and butyrylcholinesterase were evaluated. Among the synthesized compounds, 4d and 4b showed the highest AChE inhibitory activities with IC50 values in the micromolar range (compound 4d: IC50 = 3.04 μM; compound 4b: IC50 = 4.64 μM). Moreover, the results of the Aβ1–40 aggregation assay revealed that compound 4b is a potent Aβ1–40 aggregation inhibitor. The kinetics of AChE enzymatic activity in the presence of 4b was investigated, and the results were indicative of a reversible partial noncompetitive type of inhibition. A molecular docking study was conducted to determine the possible allosteric binding mode of 4b with the enzyme. The allosteric nature of AChE inhibition by these compounds provides the opportunity for the design of subtype‐selective enzyme inhibitors. The presented indanone–carbamate scaffold can be structurally modified and optimized through medicinal chemistry‐based approaches for designing novel multitargeted anti‐Alzheimer agents.
Cytotoxic and antimicrobial potential of benzimidazole derivatives
Authors: Küçükbay Hasan , Uçkun Mustafa , Apohan Elif , Yeşilada Özfer
Published: April 2021

New benzimidazole derivatives were synthesized and their structures were characterized by spectroscopic and microanalysis techniques. The cytotoxic properties of ten benzimidazole derivatives, five of which were synthesized in our previous studies, were determined against the lung cancer cell line, A549, and the healthy lung epithelial cell line, BEAS‐2B. Among the ten compounds tested, based on the 72‐h incubation results, compound 12 was the most cytotoxic against the A549 cell line, whereas against the BEAS‐2B cell line, it was as cytotoxic as cisplatin. The IC50 values of compound 12 were 3.98 and 2.94 µg/ml for A549 and BEAS‐2B cells, respectively. The cisplatin values were 6.75 and 2.75 µg/ml for A549 and BEAS‐2B cells, respectively. Compounds 10, 8, 7, and 13 showed toxic effects against A549 cells, but were less toxic against BEAS‐2B cells than cisplatin. The antimicrobial activity of these compounds against pathogenic bacteria and yeasts was also evaluated based on their minimum inhibitory concentration (MIC) values. The compounds, except 12 and 13, generally showed higher antimicrobial activity against yeasts, compared with bacteria. Compound 12 showed better activity against Pseudomonas aeruginosa and Staphylococcus aureus than against Escherichia coli. Compounds 7, 8, and 11 were the most effective ones against the microorganisms, and yeasts were highly sensitive to these compounds with MIC values of 25–100 µg/ml.
Understanding the process of data reuse: An extensive review
Authors: Wang Xiaoguang , Duan Qingyu , Liang Mengli
Published: April 2021

Data reuse has recently become significant in academia and is providing new impetus for academic research. This prompts two questions: What precisely is the data reuse process? What is the connection between each participating element? To address these issues, 42 studies were reviewed to identify the stages and primary data reuse elements. A meta‐synthesis was used to locate and analyze the studies, and inductive coding was used to organize the analytical process. We identified three stages of data reuse—initiation, exploration and collection, and repurposing—and explored how they interact and form iterative characteristics. The results illuminated the data reuse at each stage, including issues of data trust, data sources, scaffolds, and barriers. The results indicated that multisource data and human scaffolds promote reuse behavior effectively. Further, two data and information search patterns were extracted: reticular centripetal patterns and decentralized centripetal patterns. Three paths with elements cooperating through flexible functions and motivated by different action items were identified: data centers, human scaffolds, and publications. This study supports improvements for data infrastructure construction, data reuse, and data reuse research by providing a new perspective on the effect of information behavior and clarifying the stages and contextual relationships between various elements.
Modification of the association between diabetes and birth defects by obesity, National Birth Defects Prevention Study, 1997–2011
Authors: Tinker Sarah C. , Gilboa Suzanne M. , Moore Cynthia A. , Waller D. Kim , Simeone Regina M. , Kim Shin Y. , Jamieson Denise J. , Botto Lorenzo D. , Fisher Sarah C. , Reefhuis Jennita ,   the National Birth Defects Prevention Study
Published: April 2021

Background

Maternal pregestational diabetes and obesity are risk factors for birth defects. Diabetes and obesity often occur together; it is unclear whether their co‐occurrence compounds birth defect risk.

Methods

We analyzed 1997–2011 data on 29,671 cases and 10,963 controls from the National Birth Defects Prevention Study, a multisite case‐control study. Mothers self‐reported height, pregestational weight, and diabetes (pregestational and gestational; analyzed separately). We created four exposure groups: no obesity or diabetes (referent), obesity only, diabetes only, and both obesity and diabetes. We estimated odds ratios (ORs) using logistic regression and the relative excess risk due to interaction (RERI).

Results

Among mothers with pregestational obesity without diabetes, modest associations (OR range: 1.1–1.5) were observed for neural tube defects, small intestinal atresia, anorectal atresia, renal agenesis/hypoplasia, omphalocele, and several congenital heart defects. Pregestational diabetes, regardless of obesity, was strongly associated with most birth defects (OR range: 2.0–75.9). Gestational diabetes and obesity had a stronger association than for obesity alone and the RERI (in parentheses) suggested additive interaction for hydrocephaly (1.2; 95% confidence interval [CI]: −0.1, 2.5), tetralogy of Fallot (0.9; 95% CI: −0.01, 1.8), atrioventricular septal defect (1.1; 95% CI: −0.1, 2.3), hypoplastic left heart syndrome (1.1; 95% CI: −0.2, 2.4), and atrial septal defect secundum or not otherwise specified (1.0; 95% CI: 0.3, 1.6; only statistically significant RERI).

Conclusions

Our results do not support a synergistic relationship between obesity and diabetes for most birth defects examined. However, there are opportunities for prevention by reducing obesity and improving glycemic control among women with pregestational diabetes before conception.