bluuebunny/crossref_metadata_2025_split huggingface dataset:
Semi‐Rationally Designed Short Peptides Self‐Assemble and Bind Hemin to Promote Cyclopropanation
Authors: Zozulia Oleksii , Korendovych Ivan V. 
Published: March 2020

AbstractThe self‐assembly of short peptides gives rise to versatile nanoassemblies capable of promoting efficient catalysis. We have semi‐rationally designed a series of seven‐residue peptides that form hemin‐binding catalytic amyloids to facilitate enantioselective cyclopropanation with efficiencies that rival those of engineered hemin proteins. These results demonstrate that: 1) Catalytic amyloids can bind complex metallocofactors to promote practically important multisubstrate transformations. 2) Even essentially flat surfaces of amyloid assemblies can impart a substantial degree of enantioselectivity without the need for extensive optimization. 3) The ease of peptide preparation allows for straightforward incorporation of unnatural amino acids and the preparation of peptides made from d‐amino acids with complete reversal of enantioselectivity.
Aggregation‐Induced Emission: Recent Advances in Materials and Biomedical Applications
Authors: Cai Xiaolei , Liu Bin 
Published: March 2020

AbstractThe concept of aggregation‐induced emission (AIE) has opened new opportunities in many research fields. Motivated by the unique feature of AIE fluorogens (AIEgens), during the past decade, many AIE molecular probes and AIE nanoparticle (NP) probes have been developed for sensing, imaging and theranostic applications with excellent performance outperforming conventional fluorescent probes. This Review summarizes the latest advancement of AIE molecular probes and AIE NP probes and their emerging biomedical applications. Special focus is to reveal how the AIE probes are evolved with the development of new multifunctional AIEgens, and how new strategies have been developed to overcome the limitations of traditional AIE probes for more translational applications via fluorescence imaging, photoacoustic imaging and image‐guided photodynamic/photothermal therapy. The outlook discusses the challenges and future opportunities for AIEgens to advance the biomedical field.
Factors Affecting the Thermal Comfort of Perioperative Personnel in the OR
Authors: Karahan Azize , Budak Ertürk Elif , Uğurlu Ziyafet , Ünlü Hayriye , Akovalı Nükhet , Tepe Aylin , Özhan Elbaş Nalan 
Published: March 2020

ABSTRACTThermal comfort is an important component of any work setting and can be difficult to achieve in the complex OR environment. This comparative descriptive study sought to identify factors affecting the thermal comfort of perioperative personnel in the OR (N = 68). Researchers used the American Society of Heating, Refrigerating and Air‐Conditioning Engineers Thermal Sensation Scale and researcher‐developed surveys to collect data. The mean reported thermal comfort level was −0.44 (standard deviation 1.3), which is within acceptable parameters. Factors affecting thermal comfort were gender, professional role, and wearing additional clothing. Additionally, participants who complained about temperature or ventilation were less likely to report thermal comfort levels in the normal range. Health care facility leaders should consider the comfort needs of perioperative personnel when making purchasing decisions about ventilation systems and surgical clothing; however, they also should consider other factors (eg, surgeon comfort, permeability of protective clothing to blood and other body fluids).
Clinical Issues—March 2020
Authors: deKay Karen 
Published: March 2020

THIS MONTH
Laundering microfiber cleaning supplies
Key words: cloth, mop, microfiber, laundering, microorganisms.
Significance of contact time during cleaning
Key words: disinfectant, contact time, cleaning, bactericidal efficacy.
Mask use during cystoscopy and tonsillectomy procedures
Key words: surgical mask, splash, exposure, barrier level, blood‐contaminated aerosols.
Use of radiopaque towels
Key words: radiopaque towels, radiopaque markers, soft goods, towel retention.
Personal fragrances in the perioperative setting
Key words: fragrances, fragrance sensitivity, asthma, disability.
Biomarkers for Early Cancer Diagnosis: Prospects for Success through the Lens of Tumor Genetics
Authors: Dragani Tommaso A. , Matarese Valerie , Colombo Francesca 
Published: March 2020

AbstractThousands of candidate cancer biomarkers have been proposed, but so far, few are used in cancer screening. Failure to implement these biomarkers is attributed to technical and design flaws in the discovery and validation phases, but a major obstacle stems from cancer biology itself. Oncogenomics has revealed broad genetic heterogeneity among tumors of the same histology and same tissue (or organ) from different patients, while tumors of different tissue origins also share common genetic mutations. Moreover, there is wide intratumor genetic heterogeneity among cells within any single neoplasm. These findings seriously limit the prospects of finding a single biomarker with high specificity for early cancer detection. Current research focuses on developing biomarker panels, with data assessment by machine‐learning algorithms. Whether such approaches will overcome the inherent limitations posed by tumor biology and lead to tests with true clinical value remains to be seen.
Systematic and Comparative Evaluation of Software Programs for Template‐Based Modeling of Protein Structures
Authors: Jang Woo Dae , Lee Sang Mi , Kim Hyun Uk , Lee Sang Yup 
Published: March 2020

AbstractModeling protein structures is critical for understanding protein functions in various biological and biotechnological studies. Among representative protein structure modeling approaches, template‐based modeling (TBM) is by far the most reliable and most widely used approach to model protein structures. However, it still remains as a challenge to select appropriate software programs for pairwise alignments and model building, two major steps of the TBM. In this paper, pairwise alignment methods for TBM are first compared with respect to the quality of structure models built using these methods. This comparative study is conducted using comprehensive datasets, which cover 6185 domain sequences from Structural Classification of Proteins extended for soluble proteins, and 259 Protein Data Bank entries (whole protein sequences) from Orientations of Proteins in Membranes database for membrane proteins. Overall, a profile‐based method, especially PSI‐BLAST, consistently shows high performance across the datasets and model evaluation metrics used. Next, use of two model building programs, MODELLER and SWISS‐MODEL, does not seem to significantly affect the quality of protein structure models built except for the Hard group (a group of relatively less homologous proteins) of membrane proteins. The results presented in this study will be useful for more accurate implementation of TBM.
Simultaneous increases in the levels of compatible solutes by cost‐effective cultivation of Synechocystis sp. PCC 6803
Authors: Iijima Hiroko , Watanabe Atsuko , Sukigara Haruna , Shirai Tomokazu , Kondo Akihiko , Osanai Takashi 
Published: March 2020

AbstractSynechocystis sp. PCC 6803, a cyanobacterium widely used for basic research, is often cultivated in a synthetic medium, BG‐11, in the presence of 4‐(2‐hydroxyethyl)‐1‐piperazine ethanesulfonic acid (HEPES) or 2‐[[1,3‐dihydroxy‐2‐(hydroxymethyl)propan‐2‐yl]amino]ethanesulfonic acid buffer. Owing to the high cost of HEPES buffer (96.9% of the total cost of BG‐11 medium), the biotechnological application of BG‐11 is limited. In this study, we cultured Synechocystis sp. PCC 6803 cells in BG‐11 medium without HEPES buffer and examined the effects on the primary metabolism. Synechocystis sp. PCC 6803 cells could grow in BG‐11 medium without HEPES buffer after adjusting for nitrogen sources and light intensity; the production rate reached 0.54 g cell dry weight·L−1·day−1, exceeding that of commercial cyanobacteria and Synechocystis sp. PCC 6803 cells cultivated under other conditions. The exclusion of HEPES buffer markedly altered the metabolites in the central carbon metabolism; particularly, the levels of compatible solutes, such as sucrose, glucosylglycerol, and glutamate were increased. Although the accumulation of sucrose and glucosylglycerol under high salt conditions is antagonistic to each other, these metabolites accumulated simultaneously in cells grown in the cost‐effective medium. Because these metabolites are used in industrial feedstocks, our results reveal the importance of medium composition for the production of metabolites using cyanobacteria.
Surveillance and outcomes after curative resection for gastroesophageal adenocarcinoma
Authors: Jiang Di M. , Suzuki Chihiro , Espin‐Garcia Osvaldo , Lim Charles H. , Ma Lucy X. , Sun Peiran , Sim Hao‐Wen , Natori Akina , Chan Bryan A. , Moignard Stephanie , Chen Eric X. , Liu Geoffrey , Swallow Carol J. , Darling Gail E. , Wong Rebecca , Jang Raymond W. , Elimova Elena 
Published: March 2020

AbstractBackgroundThe goal of surveillance testing is to enable curative salvage therapy through early disease detection, however supporting evidence in gastroesophageal adenocarcinoma is limited. We evaluated frequency of successful salvage therapy and outcomes in patients who underwent surveillance.MethodsA single‐site, retrospective cohort study was conducted to identify all patients who received curative resection for gastroesophageal adenocarcinoma. Surveillance testing were those investigations not triggered by abnormal symptoms, physical examination, or blood tests. Successful salvage therapy was any potentially curative therapy for disease recurrence which resulted in postrecurrence disease‐free survival ≥2 years. Time‐to‐event data were analyzed using the Kaplan‐Meier method and log rank tests.ResultsBetween 2011 and 2016, 210 consecutive patients were reviewed. Esophageal (14%), gastroesophageal junction (40%), and gastric adenocarcinomas (45%) were treated with surgery alone (29%) or multimodality therapy (71%). Adjuvant therapy was administered in 35%. At median follow‐up of 38.3 months, 5‐year overall survival (OS) rate was 56%. Among 97 recurrences, 53% were surveillance‐detected, and 46% were symptomatic. None was detected by surveillance endoscopy. Median time‐to‐recurrence (TTR) was 14.8 months. Recurrences included locoregional only (4%), distant (86%), and both (10%). Salvage therapy was attempted in 15 patients, 4 were successful. Compared to symptomatic recurrences, patients with surveillance‐detected recurrences had longer median OS (36.2 vs 23.7 months, P = .004) and postrecurrence survival (PRS, 16.5 vs 4.6 months, P < .001), but similar TTR (16.2 vs 13.3 months, P = .40) and duration of palliative chemotherapy (3.9 vs 3.3 months, P = .64).ConclusionsAmong patients surveyed, 96% of recurrences were distant, and salvage therapy was successful in only 1.9% of patients. Longer OS in patients with surveillance‐detected compared to symptomatic recurrences was not associated with significant earlier disease detection, and may be contributed by differences in disease biology. Further prospective data are warranted to establish the benefit of surveillance testing in gastroesophageal adenocarcinoma.
MicroRNA targeting of the non‐canonical planar cell polarity pathway in the developing neural tube
Authors: Mukhopadhyay Partha , Greene Robert M. , Pisano M. Michele 
Published: March 2020

AbstractMicroRNAs (miRNAs) provide context‐dependent transcriptional regulation of genes comprising signalling networks throughout the developing organism including morphogenesis of the embryonic neural tube (NT). Using a high‐sensitivity, high‐coverage microarray analysis platform, miRNA expression in the murine embryonic NT during the critical stages of its formation was examined. Analysis of a number of differentially expressed (DE) miRNAs enabled identification of several gene targets associated with cellular processes essential for normal NT development. Using computational pathway analysis, interactive biologic networks and functional relationships connecting DE miRNAs with their targeted messenger RNAs (mRNAs) were identified. Potential mRNA targets and a key signal transduction pathway governing critical cellular processes indispensable for normal mammalian neurulation were also identified. RNA preparations were also used to hybridize both miRNA arrays and mRNA arrays allowing miRNA‐mRNA target analysis using data of DE miRNAs and DE mRNAs – co‐expressed in the same developing NT tissue samples. Identification of these miRNA targets provides key insight into the epigenetic regulation of NT development as well as into potential mechanistic underpinning of NT defects.Significance of the studyThis study underscores the premise that microRNAs are potential coordinators of normal neural tube (NT) formation, via regulation of the crucial, planar cell polarity pathway. Any alteration in their expression during neurulation would result in abnormal NT development.
Hypoxia‐induced apoptosis of astrocytes is mediated by reduction of Dicer and activation of caspase‐1
Authors: Kang Yeo Wool , Kim Yoon Suk , Park Jun Young , Chu Ga‐eul , Yang Young Chul , Choi Byung Young , Cho Won Gil 
Published: March 2020

AbstractHypoxia is a condition in which the whole body or a region of the body is deprived of oxygen supply. The brain is very sensitive to the lack of oxygen and cerebral hypoxia can rapidly cause severe brain damage. Astrocytes are essential for the survival and function of neurons. Therefore, protecting astrocytes against cell death is one of the main therapeutic strategies for treating hypoxia. Hence, the mechanism of hypoxia‐induced astrocytic cell death should be fully elucidated. In this study, astrocytes were exposed to hypoxic conditions using a hypoxia work station or the hypoxia mimetic agent cobalt chloride (CoCl2). Both the hypoxic gas mixture (1% O2) and chemical hypoxia‐induced apoptotic cell death in T98G glioblastoma cells and mouse primary astrocytes. Reactive oxygen species were generated in response to the hypoxia‐mediated activation of caspase‐1. Active caspase‐1 induced the classical caspase‐dependent apoptosis of astrocytes. In addition, the microRNA processing enzyme Dicer was cleaved by caspase‐3 during hypoxia. Knockdown of Dicer using antisense oligonucleotides induced apoptosis of T98G cells. Taken together, these results suggest that astrocytic cell death during hypoxia is mediated by the reactive oxygen species/caspase‐1/classical caspase‐dependent apoptotic pathway. In addition, the decrease in Dicer levels by active caspase‐3 amplifies this apoptotic pathway via a positive feedback loop. These findings may provide a new target for therapeutic interventions in cerebral hypoxia.
Solvent‐Free Synthesis of Nano Zirconium Phenylphosphonates with Molten Phenylphosphonic Acid
Authors: Contreras‐Ramirez Aida , Tomlin Bryan E. , Day Gregory S. , Clearfield Abraham , Zhou Hong‐Cai 
Published: March 2020

AbstractNanosized α‐zirconium phenylphosphonate particles were successfully prepared by the reaction between different zirconium sources and molten phenylphosphonic acid in the absence of solvent. The resultant nanoplates exhibit particle sizes in the range of 15 to 30 nm. The use of a topotactic anion exchange method starting from α‐zirconium phosphate instead resulted in the generation of 15 to 180 nm plates, while also resulting in nanoparticles with a higher degree of crystallinity. The topotactic anion exchange of the phosphate groups by phenylphosphonate groups could be performed to completion when performed in molten phenylphosphonic acid. Characterization of both the final products as well as the individual steps in the anion exchange were performed by powder XRD, fast neutron activation analysis, TGA, FTIR spectroscopy, TEM, solid‐state NMR and XPS.
A Silane‐Based Bipolar Host with High Triplet Energy for High Efficiency Deep‐Blue Phosphorescent OLEDs with Improved Device Lifetime
Authors: Ko Soo‐Byung , Kang Sunwoo , Kim Taekyung 
Published: March 2020

AbstractA high triplet energy host is developed using a silane moiety, 9‐(4‐(triphenylsilyl)dibenzo[b,d]furan‐2‐yl)‐9H‐carbazole (SiDBFCz), is designed through extensive density functional theory (DFT) calculations to obtain appropriate hole and electron injection barriers. The chemical hardness and the charge transport characteristics are comprehensively investigated to realize a bipolar host with high triplet energy over 2.9 eV for deep blue phosphorescent organic light‐emitting diodes (PHOLEDs). The synthesized SiDBFCz clearly exhibits the bipolar characteristics especially with emitter molecules doped. An external quantum efficiency over 19 % without any microcavity optimization is achieved thanks to the good charge balance in the SiDBFCz PHOLED. The device lifetime of the SiDBFCz PHOLED is improved more than 1000 %, compared to the unipolar control devices at an initial luminance of 500 cd m−2. The dramatic enhancement of the operational stability of the deep blue PHOLED is also thoroughly investigated in terms of electrochemical stability of host molecules in charged or excited states. The results clearly indicate that the device lifetime is strongly correlated with the bond dissociation energy and the activation energy for the bond dissociation reaction in triplet excited state.
Probing the Water Stability Limits and Degradation Pathways of Metal–Organic Frameworks
Authors: Safy Mohamed E. A. , Amin Muhamed , Haikal Rana R. , Elshazly Basma , Wang Junjun , Wang Yuemin , Wöll Christof , Alkordi Mohamed H. 
Published: March 2020

AbstractA comprehensive model to describe the water stability of prototypical metal–organic frameworks (MOFs) is derived by combining different types of theoretical and experimental approaches. The results provide an insight into the early stages of water‐triggered destabilization of MOFs and allow detailed pathways to be proposed for the degradation of different MOFs under aqueous conditions. The essential elements of the approach are computing the pKa values of coordinated water molecules and geometry relaxations. Variable‐temperature and pH infrared spectroscopy techniques are used to corroborate the main findings. The model developed herein helps to explain stability limits observed for several prototypical MOFs, including MOF‐5, HKUST‐1, UiO‐66, and MIL‐101‐Cr, in aqueous solutions, and thus, provides an insight into the possible degradation pathways in acidic and basic environments. The formation of a metal hydroxide through the autoprotolysis of metal‐coordinated water molecules and the strength of carboxylate–metal interactions are suggested to be two key players that govern stability in basic and acidic media, respectively. The methodology presented herein can effectively guide future efforts, which are especially significant for in silico screening, for developing novel MOFs with enhanced aqueous stability.
Sulfonation of 3,3′‐Diformyl‐BINOL for Enantioselective Fluorescent Recognition of Amino Acids in Water
Authors: Zhao Feng , Wang Yalin , Wu Xuedan , Yu Shanshan , Yu Xiaoqi , Pu Lin 
Published: March 2020

AbstractReaction of (R)‐3,3′‐diformyl‐1,1′‐bi‐2‐naphthol with concentrated sulfuric acid gives the corresponding 6,6′‐disulfonated compound (R)‐2 selectively. This provides a simple and efficient method to convert a water‐insoluble compound to a water‐soluble fluorescent probe. It is found that (R)‐2 in combination with Zn2+ shows a highly enantioselective fluorescent response toward various amino acids in the aqueous HEPES buffer solution at pH 7.4. For example, an enantioselective fluorescence enhancement ratio [ef=ΔID/ΔIL] up to 35.8 is observed for the recognition of asparagine. NMR and mass spectroscopic investigations are conducted to explore the reaction of (R)‐2 with asparagine.
A Fast, Low‐Temperature Synthesis Method for Hexagonal YMnO3: Kinetics, Purity, Size and Shape as Studied by In Situ X‐ray Diffraction
Authors: Marshall Kenneth P. , Blichfeld Anders B. , Skjærvø Susanne L. , Grendal Ola G. , van Beek Wouter , Selbach Sverre M. , Grande Tor , Einarsrud Mari‐Ann 
Published: March 2020

AbstractThe reaction mechanisms, phase development and kinetics of the hydrothermal synthesis of hexagonal‐YMnO3 from Y2O3 and Mn2O3 using in situ X‐ray diffraction are reported under different reaction conditions with temperatures ranging from 300 to 350 °C, and using 1, 5 and 10 m KOH, and 5 m NaOH mineraliser. Reactions initiated with Y2O3 hydrating to Y(OH)3, which then dehydrated to YO(OH). Higher temperatures and KOH concentrations led to faster, more complete dehydrations. However, 1 m KOH led to YO(OH) forming concurrently with Y(OH)3 before Y(OH)3 fully dehydrated but yielded a very low phase purity of hexagonal‐YMnO3. Using NaOH mineraliser, no YO(OH) was observed. Dehydration also initiated at a higher temperature in the absence of Mn2O3. The evolution of Rietveld refined scale factors was used to determine kinetic information and approximate activation energies for the reaction. The described hydrothermal synthesis offers a fast, low‐temperature method for producing anisometric h‐YMnO3 particles.
Late‐Stage Functionalization by Chan–Lam Amination: Rapid Access to Potent and Selective Integrin Inhibitors
Authors: Robinson Henry , Oatley Steven A. , Rowedder James E. , Slade Pawel , Macdonald Simon J. F. , Argent Stephen P. , Hirst Jonathan D. , McInally Thomas , Moody Christopher J. 
Published: March 2020

AbstractA late‐stage functionalization of the aromatic ring in amino acid derivatives is described. The key step is a copper‐catalysed diversification of a boronate ester by amination (Chan–Lam reaction) that can be carried out on a complex β‐aryl‐β‐amino acid scaffold. This not only considerably extends the substrate scope of amination partners, but also delivers an array of potent and selective integrin inhibitors as potential treatment agents of idiopathic pulmonary fibrosis (IPF). This versatile chemical strategy, which is amenable to high‐throughput‐array protocols, allows the installation of pharmaceutically valuable heteroaromatic fragments at a late stage by direct coupling to NH heterocycles, leading to compounds with drug‐like attributes. It thus constitutes a useful addition to the medicinal chemist's repertoire.
Asymmetric Intramolecular Hydroalkoxylation of Unactivated Alkenes Catalyzed by Chiral N‐Triflyl Phosphoramide and TiCl4†
Authors: Zhao Pengyuan , Cheng Aolin , Wang Xinxu , Ma Jiguo , Zhao Guoqing , Li Yingkun , Zhang Yi , Zhao Baoguo 
Published: March 2020

Summary of main observation and conclusionBy using a combination of a chiral N‐triflyl phosphoramide and TiCl4 as the catalyst, a new process for asymmetric intramolecular hydroalkoxylation of unactivated alkenes was developed, producing various chiral tetrahydrofuran derivatives in 51%—99% yields with 30%—71% ee's.