bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
Late‐Stage Deoxyfluorination of Phenols with PhenoFluorMix
Authors: Chen† Junting , Ritter* Tobias 
Published: April 2020

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract2‐(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

Abstract
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

AbstractEnantiopure 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

AbstractSmall‐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

AbstractThe 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

AbstractDynamic 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

AbstractThe 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

ObjectiveTo provide guidance to rheumatology providers on the management of adult rheumatic disease in the context of the coronavirus disease 2019 (COVID‐19) pandemic.MethodsA 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.ResultsThe task force approved 77 initial guidance statements: 36 with moderate and 41 with high consensus. These were combined, resulting in 25 final guidance statements.ConclusionThese 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

AbstractAmong 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

AbstractCyclic 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

AbstractThe 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

AbstractA 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.