bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding the Effects of Climate Change on Crop and Livestock Productivity in Nigeria
Authors: Gbenga Opeyemi , Opaluwa H. I. , Olabode Awarun , Ayodele Olowogbayi Jonathan
Published: April 2020

Aim: Agriculture entails majorly crop and animal production. Crop and Livestock production provide the major human caloric and nutrition intake. Assessing the impact of climate change on crop and livestock productivity, is therefore critical to maintaining food supply in the world and particularly in Nigeria. Different studies have yielded different results in other parts of the world, it is therefore, very important to examine the linkage between climate change and agricultural productivity in Nigeria.

Study Design: The study utilized secondary data. The study utilize climate data from Nigerian Meteorology Station and Carbon emission, Crop and Livestock production data from FOASTAT.

Place and Duration of Study: The study was carried in Nigeria and it covers the period between 1970-2016.

Methodology: The data were used to estimate the empirical models. Data were analyzed using descriptive statistics, trend analysis, stationarity, Co-integration and Fully-Modified Least Squares regression.

Results: The result of the research reveals that there is variation in the trend of the climatic factors examined and also variation in crop and livestock production over the period covered by the study in Nigeria. The finding also shows that rainfall, temperature and Carbon emission are the climatic factors that significantly affect crop and livestock production in Nigeria. Long term adverse impact of climate change on crop and livestock production index indicates threat to food availability to the country.

Conclusion: The study concluded that climatic variables have significant effect on agricultural productivity in Nigeria. The study recommended the need to put in place measures that will reduce the negative effects of climate on agricultural production.
Adsorption Behavior of Sodium Hydrogen Sulfate on Silica Gel
Authors: Xu Jumei , Jiang Zhongkai , Zeng Zuoxiang , Xue Weilan
Published: April 2020

The adsorption behavior of sodium bisulfate on silica gel was studied. The adsorption isothem of sodium hydrogen sulfate on silica gel were measured in the temperature range of 298.15 ~ 328.15 K, and the Langmuir model and the Dubini-Radushkevich (D-R) model were used to fit the experimental isotherm data. The average characteristic concentration (Ce') of NaHSO4 was determined at different temperatures to distinguish chemisorption from physisorption. The values of the mean free energy (E) calculated from the D−R isotherm equation indicated that the adsorption of NaHSO4 on silica gel occurs by sequential chemical and physical mechanisms.
Biosynthesized Silver Nanoparticles Using an Aqueous Root Extract of Iris germanica as a Reducing Agent and Its Antibacterial Efficacy
Authors: Hiral Vaghela , Rahul Shah , Shailesh Vajapara , Amanullakhan Pathan
Published: April 2020

Biosynthesized silver nanoparticles (AgNPs) are environment friendly, cost-effective, bio-compatible and expanding research area due to their potential applications in medical domain. The present study focuses on biologically synthesized of AgNPs using aqueous root extract of  Iris germanica as reducing agent as well as capping agent and examined their potential antibacterial efficacy. In reduction reaction it was observed that silver (Ag+1) ions associate in root extract and reduced in solution (Ag0) leads to formation of stable formation of spherical AgNPs. Biosynthesized AgNPs showed an effective and rapid antibacterial activity against both bacterial strain (gram+ve and gram-ve). Results exhibited that AgNPs were extremely toxic towards Bacillus subtilis and Escherichia coli pathogenic bacterial strains and can be utilized for the applications in biomedical science.
Nutrient Uptake and Soil Fertility Status under Different Cropping Systems for Integrated Farming Systems of Telangana State, India
Authors: Kumari Ch. Pragathi , Goverdhan M. , Reddy G. Kiran , Sridevi S.
Published: April 2020

An Randamised Block Design (RBD) field investigation with ten crop sequences under irrigation with recommended package of practices in sandy loam soils of Southern Telangana Zone (STZ), Telangana was carried out during Kharif, Rabi and summer of 2018-2019 with an objective of the nutrient uptake and soil fertility status under different cropping systems and to assess agro economic benefit. These ten cropping systems were grouped in to five categories viz., pre dominant cropping systems of the zone, ecological cropping systems, household nutritional security giving cropping systems, fodder security giving cropping systems and cropping systems involving high value crops. So that from each category, best cropping system can be identified and can be suggested to different integrated farming systems models. In the context of farming systems, under high value crops such as Okra–Marigold–Beetroot system recorded significantly higher rice grain equivalent yield (36,434 kg ha-1) over other systems. Among the ecological cropping systems for improving soil health, Bt cotton + green gram (1:3) - groundnut cropping system was recorded significantly higher rice grain equivalent yield (14,080 kg ha-1) as  compared to pigeon pea + green gram (1:7) – sesame cropping system. Among the household nutritional security giving crops, pigeon pea + maize (1:3) – groundnut system was recorded higher rice grain equivalent yield (13,693 kg ha-1). Within the two fodder crops, fodder maize – lucerne system was resulted in higher rice grain equivalent yield (7,709 kg ha-1). Rice - maize and Bt cotton which were the pre-dominant cropping systems of the region wherein rice – maize system recorded comparatively higher rice grain equivalent yield (11,771 kg ha-1) than Bt cotton. Fodder systems were found to be more exhaustive than all other cropping systems. However, within two years of experimentation the changes in physic-chemical properties and soil fertility status were not significantly affected except organic carbon. Organic carbon was high (0.45 %) in case of pigeon pea + green gram (1:6) - sesame cropping system.
Strategy to Maintain the Regional Food Security in Province of Bali, Indonesia
Authors: Sumarniasih Made Sri , Antara Made
Published: April 2020

Based on the results of the first phase research in 2018, it was found that regional food security in the Province of Bali is in a resistant and guaranteed condition. However, the problem is how to sustainably maintain Bali's regional food security in the Province of Bali? The objective of the research in 2019 is to formulate general and alternative strategies to maintain Bali's regional food security. The method for formulating general strategy using IFAS-EFAS matrices and formulating alternative strategy is the SWOT matrices. The results of the research found that the grand strategy for maintaining regional food security in the Province of Bali is a “Defend and Maintain”. Alternative strategies namely: (1) Collaboration on Penta-Helix, namely Academic, Business, Community, Government, and Media (ABCGM) to create a strong food security system; (2) Increase food production as part of regional and national food availability; (3) Utilizing the development of agricultural technology 4.0, cultivation technology and food processing technology; (4) Conducting research and development, cooperation with research institutions, universities and National Atomic Energy Agency, as well as improving institutional facilities; (5) The synergy of all Regional Apparatus Organizations belonging to the Regional Food Security Council, both at the district and provincial levels following their respective roles in efforts to strengthen food security; (6) Increase government to government cooperation and government to business to support food security programs and activities; (7) Slow download conversion, maintain the area of rice fields as the main producer of rice food.
Answer Sheet Recognition System Design
Authors: Gao Guanyang , Wang Yaoyao
Published: April 2020

Examination is an indispensable way for students to verify their learning achievements and select talents. With the continuous development of computer technology, especially the emergence of answer sheets, computers have become the mainstream instead of manual examination. The main research content of this design is to use MATLAB software to identify and obtain the information in the answer sheet, import the completed answer sheet into the system, and use MATLAB software to preprocess the image to obtain an image that can be identified later. Through the system to identify the information in the answer card and compare the correct answers, finally realize the identification of the candidate's student number, identification of subjects, reminders of missing information, and calculation of scores and other functions. This article designed the GUI interface, which provided convenience for human-computer interaction, making the system operation more convenient and the results clear.
Late‐Stage Deoxyfluorination of Phenols with PhenoFluorMix
Authors: Chen† Junting , Ritter* Tobias
Published: April 2020

This article describes the procedure for late‐stage deoxyfluorination of phenols with PhenoFluorMix. It presents some of the important points to be considered, the conditions that need to be maintained, characterization data, and the reagents required, as well as the techniques used and the equipment setup that are vital to carrying out the process. PhenoFluor‐based reagents PhenoFluorMix and Alkylfluor are useful, practical reagents that can be used for reliable deoxyfluorination of substrates that are too complex for other deoxyfluorination reagents. The article also describes the hazards associated with working with chemicals and the ways to deal with these hazards.
Discussion Addendum for: Lithium Amides as Homochiral Ammonia Equivalents for Conjugate Additions to α,β‐Unsaturated Esters: Asymmetric Synthesis of (
S
)‐ β‐Leucine
Authors: Davies* Stephen G. , Fletcher Ai M. , Roberts Paul M. , Thomson James E.
Published: April 2020

The conjugate addition of enantiopure lithium N‐benzyl‐N‐(amethylbenzyl) amide to α,β unsaturated esters and amides displays high diastereoselectivity with extremely wide substrate scope and thus this process has been recognized as one of the most robust and reliable methods to prepare β‐amino acid derivatives. This methodology has found numerous applications, including in the areas of target synthesis and molecular recognition phenomena. Several chemoselective deprotection methods for removal of the N‐protecting groups have been developed. In order to expand the structural diversity of the accessible β‐amino acid derivatives, α‐functionalisation of the β‐amino ester has been investigated. α‐Functionalisation of the β‐amino acid derivatives can be achieved via elaboration of the intermediate enolate resulting from conjugate addition of a lithium amide reagent to an α,β‐unsaturated ester with an electrophile (tandem manner). This conjugate addition will continuously contribute not only to the area of amino acid/peptide chemistry but also in the areas of natural products and pharmaceutically important target syntheses.
Discussion Addendum For: Phosphine‐Catalyzed [4 + 2] Annulation: Synthesis of Ethyl 6‐Phenyl‐1‐Tosyl‐1,2,5,6‐Tetrahydropyridine‐3‐Carboxylate
Authors: Shaikh Aslam C. , Kwon* Ohyun
Published: April 2020

There has been remarkable progress in organophosphine‐catalyzed reactions, especially the processes involving annulations, because of their potential application in building 5–8‐membered cyclic products. The phosphine‐catalyzed [4 + 2] annulation between 2‐alkyl‐but‐2,3‐dienoates and aldimines has become a powerful tool in the construction of substituted tetrahydropyridine derivatives. This discussion addendum focuses on new developments of the [4 + 2] annulation–including its asymmetric versions and synthetic utility–since 2003. The potential of the allene‐imine [4 + 2] annulation reaction in the total synthesis of natural product was illustrated in the formal synthesis of alstonerine. The discussion addendum presents the application of [4 + 2] annulation reaction. The [4 + 2] annulations between allene and imine will continue to find use in valuable product syntheses, especially those for which mild conditions, robust efficiency, and high selectivity are paramount.
Gold‐Catalyzed Oxidative Coupling of Arenes and Arylsilanes
Authors: Nottingham Chris , Barber Verity , Lloyd‐Jones* Guy C.
Published: April 2020

This article describes the procedure for gold‐catalyzed oxidative coupling of arenes and arylsilanes. It presents some of the important points to be considered, the conditions that need to be maintained, characterization data, and the reagents required, as well as the techniques used and the equipment setup that are vital to carrying out the process. The chapter provides an overview, the scope and limitations of intermolecular and intramolecular coupling of arenes and aryl silanes and intermolecular coupling of heteroarenes and aryl silanes. It also presents a detailed procedure for the preparation and cyclization of 1‐trimethylsilyl‐2‐(phenoxymethyl)benzene as a general example for the arylation of aryl silanes. The article also describes the hazards associated with working with chemicals and the ways to deal with these hazards.
Three‐Step Synthesis of 2‐(Diiodomethyl)‐4,4,5,5‐Tetramethyl‐1,3,2‐Dioxaborolane from Dichloromethane
Authors: Sayes Morgane , Benoit Guillaume , Charette* André B.
Published: April 2020

2‐(diiodomethyl)‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane is used to perform direct borocyclopropanation reactions; direct meaning that the cyclopropane ring is formed at the same time as the boronic ester is installed. This article describes the procedure for the synthesis of 2‐(diiodomethyl)‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane from dichloromethane. It presents some of the important points to be considered, the conditions that need to be maintained, characterization data, and the reagents required, as well as the techniques used and the equipment setup that are vital to carrying out the process. 2‐(diiodomethyl)‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane has been used in a chromium‐promoted borocyclopropanation. This methodology is applicable to unactivated alkenes under mild conditions with good stereoselectivities and good functional group tolerance. The article also describes the hazards associated with working with chemicals and the ways to deal with these hazards.
Catalytic Enantioselective Addition of an In‐Situ Prepared Aryltitanium Reagent to
p
‐Chloroacetophenone: (
R
)‐(+)‐1‐(4‐Chlorophenyl)‐1‐
m
‐Tolylethanol
Authors: Kobayashi Yusuke , Matsuda Atsushi , Ushimaru Tomoya , Harada* Toshiro
Published: April 2020

Chiral tertiary diaryl carbinols are key intermediates for the synthesis of pharmacologically active compounds. This article describes the procedure for the catalytic enantioselective addition of an in‐situ prepared aryltitanium reagent to p‐chloroacetophenone: (R)‐(+)‐1‐(4‐chlorophenyl)‐1‐m‐tolylethanol. It presents some of the important points to be considered, the conditions that need to be maintained, characterization data, and the reagents required, as well as the techniques used and the equipment setup that are vital to carrying out the process. For the enantioselective synthesis, much effort has been directed toward the development of the catalytic enantioselective arylation of alkyl aryl ketones. Catalytic methods utilizing arylzinc, ‐aluminum, ‐titanium, and ‐boron reagents are explored. However, reactions are generally carried out at relatively large catalyst loadings, making them less practical for scale‐up applications. The article also describes the hazards associated with working with chemicals and the ways to deal with these hazards.
Discussion Addendum for: Preparation of (R,R)‐1,2:4,5‐Diepoxypentane
Authors: Sizemore* Nicholas , Rychnovsky* Scott D.
Published: April 2020

Enantiopure 1,2:4,5‐diepoxypentanes and their dichlorodiol precursors have proven to be useful intermediates in the synthesis of complex natural products. While these C2 symmetric bis‐electrophiles have most commonly been employed in the installation of anti‐1,3 diol motifs, they have also recently been leveraged in development of new methods and utilized in the synthesis of chiral building blocks. This addendum discusses these applications, as well as the use of these materials in the context of the total synthesis of complex natural products. It provides information on simultaneous and sequential double addition strategies in natural product synthesis. The addendum also discusses the P. R. Hanson's synthesis of chiral bicyclo[4.3.1]phosphate triester building blocks and J. Aube's extension through synthesis of valuable chiral building blocks.
miR‐505 inhibits proliferation of osteosarcoma via HMGB1
Authors: Li Guangzhang , Liu Fajing , Miao Jun , Hu Yongcheng
Published: April 2020

Osteosarcoma is a malignant bone tumor, and clinically detectable metastases can be detected in ~ 15–20% of patients when they seek medical advice; patients with metastatic disease have extremely poor prognosis. Here, we examined the involvement of the microRNA miR‐505 in osteosarcoma. Eighty‐four patients seeking treatment for osteosarcoma were included in the study group (SG), and 63 healthy subjects were allocated to the control group (CG). Normal human bone cells MG‐63 and U20S cells were transfected with miR‐505 mimics, miR‐NC, HMGB1 RNA for targeted inhibition (si‐HMGB1), and si‐NC to examine the effects on HMGB1 expression. Cell proliferation, invasion, and apoptosis were measured using CCK‐8, scratch assays, and flow cytometry (FCM), respectively, and the relationship between miR‐505 and HMGB1 was determined using the dual‐luciferase reporter assay. In patient tissues and serum, miR‐505 was expressed at a low level, and HMGB1 was expressed at a high level, with an area under curve of > 0.9. Furthermore, the expression of miR‐505 and HMGB1 in tissues had a positive association with that in the serum, whereas the expression of miR‐505 had a negative association with that of HMGB1 in tissues only. Overexpression of miR‐505 and silencing of HMGB1 suppressed the proliferation, migration, and invasion of osteosarcoma cells and increased the rate of apoptosis, whereas the co‐transfected miR‐505 mimics + si‐HMGB1 demonstrated a more significant inhibitory effect on the proliferation and invasion of osteosarcoma cells and a higher apoptosis rate. miR‐505 may inhibit the proliferation and invasion and promote apoptosis of osteosarcoma cells by targeting and suppressing HMGB1.
Asymmetric Acceptors with Fluorine and Chlorine Substitution for Organic Solar Cells toward 16.83% Efficiency
Authors: Liu Tao , Zhang Youdi , Shao Yiming , Ma Ruijie , Luo Zhenghui , Xiao Yiqun , Yang Tao , Lu Xinhui , Yuan Zhongyi , Yan He , Chen Yiwang , Li Yongfang
Published: April 2020

Small‐molecule acceptors (SMAs)‐based organic solar cells (OSCs) have exhibited great potential for achieving high power conversion efficiencies (PCEs). Meanwhile, developing asymmetric SMAs to improve photovoltaic performance by modulating energy level distribution and morphology has drawn lots of attention. In this work, based on the high‐performance SMA (Y6), three asymmetric SMAs are developed by substituting the fluorine atoms on the terminal group with chlorine atoms, namely SY1 (two F atoms and one Cl atom), SY2 (two F atoms and two Cl atoms), and SY3 (three Cl atoms). Y6 (four F atoms) and Y6‐4Cl (four Cl atoms) are synthesized as control molecules. As a result, SY1 exhibits the shallowest lowest unoccupied molecular orbital energy level and the best molecular packing among these five acceptors. Consequently, OSCs based on PM6:SY1 yield a champion PCE of 16.83% with an open‐circuit voltage (VOC) of 0.871 V, and a fill factor (FF) of 0.760, which is the best result among the five devices. The highest FF for the PM6:SY1‐based device is mainly ascribed to the most balanced charge transport and optimal morphology. This contribution provides deeper understanding of applying asymmetric molecule design method to further promote PCEs of OSCs.
Pay Attention to Biological Nanoparticles when Studying the Protein Corona on Nanomedicines
Authors: Simonsen Jens B. , Münter Rasmus
Published: April 2020

The protein corona of nanoparticles has in recent years received considerable attention, and even been postulated to be the missing link in the translation of nanomedicines from benchtop to bedside. We highlight the different types of biological nanoparticles present in blood that need to be considered in the protein corona research field. We map their size, density, and plasma concentrations, and use this information to stress potential challenges related to the isolation of nanomedicines—with a particular focus on liposomes—when using the traditional isolation methods that separate according to size and density.
Live‐Cell‐Templated Dynamic Combinatorial Chemistry
Authors: Carbajo Daniel , Pérez Yolanda , Bujons Jordi , Alfonso Ignacio
Published: April 2020

Dynamic covalent chemistry combines in a single step the screening and synthesis of ligands for biomolecular recognition. In order to do that, a chemical entity is used as template within a dynamic combinatorial library of interconverting species, so that the stronger binders are amplified due to the efficient interaction with the target. Here we employed whole A549 living cells as template in a dynamic mixture of imines, for which amplification reflects the efficient and selective interaction with the corresponding extracellular matrix. The amplified polyamine showed strong interaction with the A549 extracellular matrix in on‐cell NMR experiments, while combination of NMR, SPR, and molecular dynamics simulations in model systems provided insights on the molecular recognition event. Notably, our work pioneers the use of whole living cells in dynamic combinatorial chemistry, which paves the way towards the discovery of new bioactive molecules in a more biorelevant environment.
Promoted Electrocatalytic Nitrogen Fixation in Fe‐Ni Layered Double Hydroxide Arrays Coupled to Carbon Nanofibers: The Role of Phosphorus Doping
Authors: Liu Yi‐Tao , Tang Lu , Dai Jin , Yu Jianyong , Ding Bin
Published: April 2020

The key to bringing the electrocatalytic nitrogen fixation from conception to application lies in the development of high‐efficiency, cost‐effective electrocatalysts. Layered double hydroxides (LDHs), also known as hydrotalcites, are promising electrocatalysts for water splitting due to multiple metal centers and large surface areas. However, their activities in the electrocatalytic nitrogen fixation are unsatisfactory. Now, a simple and effective way of phosphorus doping is presented to regulate the charge distribution in LDHs, thus promoting the nitrogen adsorption and activation. The P‐doped LDHs are further coupled to a self‐supported, conductive matrix, that is, a carbon nanofibrous membrane, which prevents their aggregation as well as ensuring rapid charge transfer at the interface. By this strategy, decent ammonia yield (1.72×10−10 mol s−1 cm−2) and Faradaic efficiency (23 %) are delivered at −0.5 V vs. RHE in 0.1 m Na2SO4.
American College of Rheumatology Guidance for the Management of Rheumatic Disease in Adult Patients During the COVID‐19 Pandemic: Version 1
Authors: Mikuls Ted R. , Johnson Sindhu R. , Fraenkel Liana , Arasaratnam Reuben J. , Baden Lindsey R. , Bermas Bonnie L. , Chatham Winn , Cohen Stanley , Costenbader Karen , Gravallese Ellen M. , Kalil Andre C. , Weinblatt Michael E. , Winthrop Kevin , Mudano Amy S. , Turner Amy , Saag Kenneth G.
Published: April 2020

Objective

To provide guidance to rheumatology providers on the management of adult rheumatic disease in the context of the coronavirus disease 2019 (COVID‐19) pandemic.

Methods

A task force, including 10 rheumatologists and 4 infectious disease specialists from North America, was convened. Clinical questions were collated, and an evidence report was rapidly generated and disseminated. Questions and drafted statements were reviewed and assessed using a modified Delphi process. This included 2 rounds of asynchronous anonymous voting by e‐mail and 3 webinars with the entire panel. Task force members voted on agreement with draft statements using a 1–9‐point numerical scoring system, and consensus was determined to be low, moderate, or high based on the dispersion of votes. For approval, median votes were required to meet predefined levels of agreement (median values of 7–9, 4–6, and 1–3 defined as agreement, uncertainty, or disagreement, respectively) with either moderate or high levels of consensus.

Results

The task force approved 77 initial guidance statements: 36 with moderate and 41 with high consensus. These were combined, resulting in 25 final guidance statements.

Conclusion

These guidance statements are provided to promote optimal care during the current pandemic. However, given the low level of available evidence and the rapidly evolving literature, this guidance is presented as a “living document,” and future updates are anticipated.
Development of Core‐Shell Nanoparticle Drug Delivery Systems Based on Biomimetic Mineralization
Authors: Yang Guangze , Liu Yun , Jin Song , Zhao Chun‐Xia
Published: April 2020

Among various drug‐delivery systems, core‐shell nanoparticles have many advantages. Inspired by nature, biomimetic synthesis has emerged as a new strategy for making core‐shell nanoparticles in recent years. Biomimetic mineralization is the process by which living organisms produce minerals based on biomolecule templating that leads to the formation of hierarchically structured organic–inorganic materials. In this minireview, we mainly focus on the synthesis of core‐shell nanoparticle drug‐delivery systems by biomimetic mineralization. We review various biomimetic mineralization methods for fabricating core‐shell nanoparticles including silica‐based, calcium‐based and other nanoparticles, and their applications in drug delivery. We also summarize strategies for drug loading in the biomolecule‐mineralized core‐shell NPs. Current challenges and future directions are also discussed.
Tuning the Innate Immune Response to Cyclic Dinucleotides by Using Atomic Mutagenesis
Authors: Li Yao , Fin Andrea , Rovira Alexander R. , Su Yichi , Dippel Andrew B. , Valderrama Jonathan Andrés , Riestra Angelica M. , Nizet Victor , Hammond Ming C. , Tor Yitzhak
Published: April 2020

Cyclic dinucleotides (CDNs) trigger the innate immune response in eukaryotic cells through the stimulator of interferon genes (STING) signaling pathway. To decipher this complex cellular process, a better correlation between structure and downstream function is required. Herein, we report the design and immunostimulatory effect of a novel group of c‐di‐GMP analogues. By employing an “atomic mutagenesis” strategy, changing one atom at a time, a class of gradually modified CDNs was prepared. These c‐di‐GMP analogues induce type‐I interferon (IFN) production, with some being more potent than c‐di‐GMP, their native archetype. This study demonstrates that CDN analogues bearing modified nucleobases are able to tune the innate immune response in eukaryotic cells.
Coumarin‐Tagged Dinuclear Trithiolato‐Bridged Ruthenium(II)⋅Arene Complexes: Photophysical Properties and Antiparasitic Activity
Authors: Desiatkina Oksana , Păunescu Emilia , Mösching Martin , Anghel Nicoleta , Boubaker Ghalia , Amdouni Yosra , Hemphill Andrew , Furrer Julien
Published: April 2020

The synthesis, characterization, photophysical and biological properties of 13 new conjugate coumarin‐diruthenium(II)⋅arene complexes against Toxoplasma gondii are presented. For all conjugate organometallic unit/coumarins, an almost complete loss of fluorescence efficacy was observed. However, the nature of the fluorophore, the type of bonding, the presence and length of a linker between the coumarin dye and the ruthenium(II) moiety, and the number of dye units influenced their biological properties. The in vitro activity against a transgenic T. gondii strain grown in human foreskin fibroblasts (HFF) leads to IC50 values for T. gondii β‐gal from 105 to 735 nM. Of note is that nine compounds displayed lower IC50 than the standard drug pyrimethamine. One compound applied at its IC50 did not affect B‐cell proliferation but had an impact on T‐cell proliferation in murine splenocyte cultures. Transmission electron microscopy of T. gondii β‐gal‐infected HFF showed that treatment predominantly affected the parasites’ mitochondrion.
An Upgraded “Two‐in‐One” Strategy toward Highly Crystalline Covalent Organic Frameworks
Authors: Chen Dan , Chen Weiben , Xing Guolong , Zhang Ting , Chen Long
Published: April 2020

A highly crystalline bicarbazole‐based covalent organic framework (BCzP‐COF) was synthesized via an upgraded “two‐in‐one” strategy by the self‐polycondensation of A2B2 monomer with two neopentyl acetal and two amine groups. Such a strategy is propitious to afford higher crystallinity, larger special surface areas and better morphology than that of using unprotected monomer with free aldehydes and amines. Additionally, the off‐white powder of BCzP‐COF could serve as acidichromism sensor with a significant color change. Intriguingly, the conductivity of the protonated BCzP‐COF can improve by six orders of magnitude compared to that of the pristine samples. This work has the potential to lead to bicarbazole‐functional materials for chemosensors and electronic devices.
Esterification of Tertiary Amides: Remarkable Additive Effects of Potassium Alkoxides for Generating Hetero Manganese–Potassium Dinuclear Active Species
Authors: Hirai Takahiro , Kato Daiki , Mai Binh Khanh , Katayama Shoichiro , Akiyama Shoko , Nagae Haruki , Himo Fahmi , Mashima Kazushi
Published: April 2020

A catalyst system of mononuclear manganese precursor 3 combined with potassium alkoxide served as a superior catalyst compared with our previously reported manganese homodinuclear catalyst 2 a for esterification of not only tertiary aryl amides, but also tertiary aliphatic amides. On the basis of stoichiometric reactions of 3 and potassium alkoxide salt, kinetic studies, and density functional theory (DFT) calculations, we clarified a plausible reaction mechanism in which in situ generated manganese–potassium heterodinuclear species cooperatively activates the carbonyl moiety of the amide and the OH moiety of the alcohols. We also revealed details of the reaction mechanism of our previous manganese homodinuclear system 2 a, and we found that the activation free energy (ΔG≠) for the manganese–potassium heterodinuclear complex catalyzed esterification of amides is lower than that for the manganese homodinuclear system, which was consistent with the experimental results. We further applied our catalyst system to deprotect the acetyl moiety of primary and secondary amines.
Brønsted Acid and H‐Bond Activation in Boronic Acid Catalysis
Authors: Zhang Shaofei , Lebœuf David , Moran Joseph
Published: April 2020

Boronic acid catalysis has emerged as a mild method for promoting a wide variety of reactions. It has been proposed that the mode of catalysis involves Lewis acid or covalent activation of hydroxyl groups by boron, but limited mechanistic evidence exists. In this work, representative boronic acid catalyzed reactions of alcohols and oximes have been reinvestigated. A series of control experiments with boronic and Brønsted acids were interpreted along with correlations between their reactivity and their acidity measured by the Gutmann–Beckett method. Overall, it was concluded that the major modes of catalysis involve either dual H‐bond catalysis or Brønsted acid catalysis. Strong Brønsted acids were shown to be generated in situ from covalent assembly of the boronic acids with hexafluoroisopropanol, explaining why the solvent had such a major impact on the reactivity. This new insight should guide the future development of boronic acid catalysis, where the diverse and solvent‐specific nature of catalytic modes has been overlooked.
Facile Synthesis of Proton‐Type ZSM‐5 by Using Quasi‐Solid‐Phase (QSP) Method
Authors: Fan Subing , Tuo Jie , Wang Dan , Rong Jingya , Zhang Jianli , Ma Qingxiang , Gao Xinhua , Yang Guohui , Zhao Tiansheng , Tsubaki Noritatsu
Published: April 2020

Herein, a simple and green quasi‐solid‐phase (QSP) method for facile synthesis of proton‐type ZSM‐5 avoiding use of excessive water, dry gel, Na+ cation and fluoride is reported. Crystallization by using the stoichiometric amount of TPAOH (tetrapropylammonium hydroxide) at 180 °C for only 12 h gave well‐structured HZSM‐5 crystals with high specific surface area of 429 m2 g−1 and high thermal stability. 5MRs was observed to closely relate the formation of MFI structure and QSP method exhibits shorter induction period (t0), higher nucleation rate (Vn), and faster growth rate (Vg). Moreover, HZ‐12–180 showed extremely better and rather stable catalytic activity for methanol‐to‐propylene reaction by comparison with commercial HZSM‐5.
Hierarchical chirality expression of gemini surfactant aggregates via equilibrium between chiral nucleotide and nonchiral mono‐anions
Authors: Dedovets Dmytro , Martin Barbara , Okazaki Yutaka , Buffeteau Thierry , Pouget Emilie , Oda Reiko
Published: April 2020

The assembling behaviors of nonchiral dicationic amphiphilic molecules (gemini) in the presence of the mixture of chiral anionic nucleotides and nonchiral anions are investigated. We demonstrate that subtle balance of various physico‐chemical parameters and the competition between chiral and nonchiral anions at the interface of gemini assemblies influences the expression of molecular chirality at the micrometer scale through the hierarchical molecular assembly.
A phased approach to implementing the Breast Imaging Reporting and Data System (BI‐RADS) in low‐income and middle‐income countries
Authors: Lam Diana L. , Entezari Pegah , Duggan Catherine , Muyinda Zeridah , Vasquez Andres , Huayanay Jorge , Anderson Benjamin O. , Scheel John R.
Published: April 2020

Background

Successful breast cancer detection programs rely on standardized reporting and interpreting systems, such as the Breast Imaging Reporting and Data System (BI‐RADS), to improve system performance. In low‐income and middle‐income countries, evolving diagnostic programs have insufficient resources to either fully implement BI‐RADS or to periodically evaluate the program's performance, which is a necessary component of BI‐RADS. This leads to inconsistent breast ultrasound interpretation and a failure to improve performance.

Methods

The authors applied the Breast Health Global Initiative's phased implementation strategy to implement diagnostic ultrasound and BI‐RADS within the context of a limited‐resource setting.

Results

The authors recommended starting with triage ultrasound to distinguish suspicious masses from normal breast tissue and benign masses such as cysts because the majority of health workers performing ultrasounds at this level have minimal breast imaging experience. Transitioning to full diagnostic ultrasound with condensed or full BI‐RADS should occur after performance and quality metrics have been met.

Conclusions

Transitioning through these phases across facilities likely will occur at different times, particularly in rural versus urban settings.
For a few diversities more: A voting‐attack‐immune voting scheme for social question and answer websites
Authors: Zhang Jun , Labiod Houda , Meng Weizhi
Published: April 2020

Social question and answer (Q&A) communities or websites, such as Quora, StackOverflow, become popular from the last decade. They provide collected answers in a crowdsourcing way by encouraging the interactive between users. The ranking of answers in such Q&A websites depends on many factors, such as received upvotes, downvotes, publishing time, and so on. When there exist malicious users, they can manipulate the ranking of answers by launching voting spamming attacks. In this article, we propose a metric, diversity of visibility, to characterize the balance between rankings of answers with conflicting opinions and propose a time‐diversitybased voting scheme to reach a high diversity of visibility, so as to minimize the impact of voting spamming attacks. We evaluate the proposed metric and voting scheme in the case study of a Chinese Q&A website, Zhihu, and show that the proposed voting scheme consistently shows a good balance of answers with conflicting opinions in both actual scenarios and synthetic scenarios.
Synthesis of Metastable Inorganic Solids with Extended Structures
Authors: Cordova Dmitri Leo M. , Johnson David C.
Published: April 2020

The number of known inorganic compounds is dramatically less than predicted due to synthetic challenges, which often constrains products to only the thermodynamically most stable compounds. Consequently, a mechanism‐based approach to inorganic solids with designed structures is the holy grail of solid state synthesis. This article discusses a number of synthetic approaches using the concept of an energy landscape, which describes the complex relationship between the energy of different atomic configurations as a function of a variety of parameters such as initial structure, temperature, pressure, and composition. Nucleation limited synthesis approaches with high diffusion rates are contrasted with diffusion limited synthesis approaches. One challenge to the synthesis of new compounds is the inability to accurately predict what structures might be local free energy minima in the free energy landscape. Approaches to this challenge include predicting potentially stable compounds thorough the use of structural homologies and/or theoretical calculations. A second challenge to the synthesis of metastable inorganic solids is developing approaches to move across the energy landscape to a desired local free energy minimum while avoiding deeper free energy minima, such as stable binary compounds, as reaction intermediates. An approach using amorphous intermediates is presented, where local composition can be used to prepare metastable compounds. Designed nanoarchitecture built into a precursor can be preserved at low reaction temperatures and used to direct the reaction to specific structural homologs.
Self‐removing passive drain to facilitate postoperative care via telehealth during the COVID‐19 pandemic
Authors: Qualliotine Jesse R. , Orosco Ryan K.
Published: April 2020

Background

Telehealth postoperative visits are an attractive strategy to minimize exposure, especially during the SARS‐CoV‐2 (COVID‐19) pandemic. The use of a surgical drain often prevents this minimal‐exposure approach in that patients return to the outpatient clinic for drain removal.

Methods and Results

Following unilateral neck dissection, the customary closed‐suction drain was replaced with a self‐removing, passive drain dressing to facilitate same‐day discharge and telehealth postoperative follow‐up. The patient removed the dressing and drain at home during a telehealth visit on postoperative day 4 and she healed favorably without any signs of infection or seroma.

Conclusions

When thoughtfully applied in the appropriate clinical context, small practice adaptations like this can facilitate telehealth solutions that diminish unnecessary exposure for patients, their caregivers, and health care staff.
Development of clinical care guidelines for faculty and residents in the era of COVID‐19
Authors: Park Jason S. , El‐Sayed Ivan H. , Young VyVy N. , Pletcher Steven D.
Published: April 2020

Background

The global COVID‐19 pandemic brings new challenges to otolaryngology resident education. Surgical volume and clinic visits are curtailed, personal protective equipment for operating room participation is restricted, and the risk of COVID‐19 disease transmission during heretofore routine patient care is the new norm.

Methods

We describe a small‐team “cohorting” protocol including guidelines for faculty and resident in common clinical scenarios with attention paid to the risk of common otolaryngologic procedures.

Results

A rotating small‐team approach was implemented at each clinical site, limiting interaction between department members but providing comprehensive coverage. Faculty were involved at the earliest phase of clinical interactions. Guidelines delineated faculty and resident roles based on risk stratification by patient COVID status and anticipated procedures. Special consideration was given to high‐risk procedures such as endoscopy and tracheotomy.

Conclusions

A small‐team‐based approach with guidelines for faculty/resident roles may mitigate risk while optimizing patient care and maximizing education.
Optimal hydrothermal design of internal flow pipe with insertion of straight and helical metal foam fins
Authors: Jehad Mohammed Gh. , Ahmed Hamdi E. , Fadhil Obaid T. , Kherbeet A. Sh.
Published: April 2020

In this paper, the hydrothermal performance of a tubular heat exchanger is developed numerically by inserting metallic foam fins (MFF) in several configurations: straight single‐, single‐helical, and double‐helical MFF. The working fluid is water, whereas the volume of the MFF is kept constant throughout the whole manuscript. The geometric parameters investigated here are the aspect ratio of the rectangular porous fin, the number of turns of the fin, the number of fins, and the pores per inch for a wide range of laminar Reynolds number. The finite volume method is adopted for solving the governing equations of the laminar flow regime. The results are presented in terms of Nusselt number, friction factor, hydrothermal performance (JF), velocity, and temperature contours. The results show that the heat transfer of the smooth pipe is enhanced when a straight MFF is used. More heat removal enhancement is recorded when the MFF is twisted helically with the circumference of the pipe. Additional thermal augmentation is observed with an increase in the number of turns of the helical MFF up to a certain value. Unexpected heat transfer enhancement is recorded when a double‐helical MFF is used instead of a single‐helical one. The maximum enhancement in the JF observed is 1.7 using double‐helical MFF with two turns.
Trajectories of peer victimization in elementary school children: Associations with changes in internalizing, externalizing, social competence, and school climate
Authors: Sukhawathanakul Paweena , Leadbeater Bonnie
Published: April 2020

The current study examines the developmental changes (internalizing and externalizing symptoms, social competence, and experiences of school climate) in children who follow distinct trajectories of peer victimization in a sample of elementary school children across 2 years. Data were from children, and their parents and teachers, in Grades 1–3 followed across five waves. Latent class analyses revealed four distinct victimization trajectory groups characterized by chronically high, increasing, decreasing, or low‐stable levels across time. Multilevel analyses showed that children in the chronically high peer victimization group had higher initials levels of internalizing and externalizing symptoms, lower levels of social competence, and poorer experiences of school climate compared to children in the low‐stable group. Over time, children in the increasing group had slower rates of increases in social competence than children in the low‐stable group and had worsening experiences of school climate compared to children in the low‐stable peer victimization group. Findings suggest children who are chronically victimized may be at a developmental disadvantage compared to children who report little or declining peer victimization over time.
Insulinoma‐associated protein 1 is a prognostic biomarker in pulmonary high‐grade neuroendocrine carcinoma
Authors: Minami Kazuhiro , Jimbo Naoe , Tanaka Yugo , Ogawa Hiroyuki , Hokka Daisuke , Nishio Wataru , Yoshimura Masahiro , Itoh Tomoo , Maniwa Yoshimasa
Published: April 2020

Backgrounds and Objectives

Recent studies have suggested that insulinoma‐associated protein 1 (INSM1) is a useful marker for pathological diagnosis of pulmonary neuroendocrine tumors. In the present study, we investigated the association between INSM1 expression and prognosis in patients with pulmonary high‐grade neuroendocrine carcinomas (HGNEC) and assessed the usefulness of INSM1 as a prognostic biomarker in these patients.

Methods

Seventy‐five consecutive patients with HGNEC who underwent complete surgical resections from January 2000 to December 2018 were enrolled in this study. We classified these patients into two groups: the INSM1‐positive group (n = 59) and INSM1‐negative group (n = 16). We compared the clinicopathological characteristics, overall survival (OS), and recurrence‐free survival (RFS) between the groups. In addition, we performed univariate and multivariate analyses to identify the prognostic factors associated with postoperative survival.

Results

Significant differences in tumor diameter and vascular invasion between the groups were found. OS and RFS were significantly poorer in the INSM1‐positive group than in the INSM1‐negative group. Univariate and multivariate analyses revealed that INSM1 expression was the strongest predictor of poor prognosis for OS and RFS.

Conclusions

INSM1 expression had the greatest influence on the prognosis in patients with HGNEC and may be a prognostic biomarker in these patients.
Primary cultures of aspiration residual specimens predict outcomes of hepatocellular carcinoma patients receiving curative treatment
Authors: Lin Zu‐Yau , Wang Jing‐Houng , Yeh Ming‐Lun , Huang Ching‐I , Kee Kwong‐Ming , Yen Yi‐Hao , Chen Shinn‐Cherng , Huang Chung‐Feng , Huang Jee‐Fu , Dai Chia‐Yen , Yu Ming‐Lung , Chuang Wan‐Long
Published: April 2020

The utility of primary culture originated from the residual aspiration specimens to predict outcomes of hepatocellular carcinoma patients receiving curative treatment was investigated. A total of 105 American Joint Committee on Cancer TNM stage I or II patients were included. The culture results were determined at the 28th of culture and were divided into rapid proliferation of cancer cells alone, rapid proliferation of both cancer cells and cancer‐associated fibroblasts, rapid proliferation of cancer‐associated fibroblasts alone, slow proliferation, and no outgrowth of plating specimens. Our results showed that outgrowths of cultured cells from plated particles were achieved in 98.1% of patients. Sixty‐nine patients (65.7%) showed rapid proliferation of cultured cells (11 rapid proliferation of cancer cells alone, 17 rapid proliferation of both cancer cells and cancer‐associated fibroblasts, and 41 rapid proliferation of cancer‐associated fibroblasts alone). There was no significant difference in the incidence of recurrence or survival between patients with normal and abnormal serum alpha‐fetoprotein levels, chronic hepatitis B and chronic hepatitis C, TNM stage I and stage II, histological high‐grade and low‐grade hepatocellular carcinoma, and between patients treated by operative resection and local abrasion. Only patients with rapid proliferation of cancer cells ± rapid proliferation of cancer‐associated fibroblasts showed significantly higher incidence of recurrence than patients with other growth types (P = .0482), but there was no significant difference in survival between two groups. In conclusion, primary culture using this method is clinically feasible and can be applied to predict recurrence of hepatocellular carcinoma patients receiving curative treatment.