bluuebunny/crossref_metadata_2025_split huggingface dataset:
Straightforward Access to the Nitric Oxide Donor Azasydnone Scaffold by Cascade Reactions of Amines
Authors: Zhilin Egor S. , Bystrov Dmitry M. , Ananyev Ivan V. , Fershtat Leonid L. , Makhova Nina N. 
Published: September 2019

AbstractA novel one‐pot cascade method for the assembly of valuable NO‐donor azasydnone scaffold has been developed. The construction strategy involves a diazotization/azo coupling/elimination/double rearrangement cascade sequence of readily available amines. The current protocol enables the generation of a diverse array of azasydnones, including previously hardly accessible heteroaryl substituted azasydnones (25 examples, 70–97 % yield) with a good functional group tolerance under very mild conditions. Preliminary NO‐releasing studies revealed an ability of azasydnones to produce NO in a wide range of concentrations. This method provides a new approach to nitrogen‐oxygen heterocycles with potential applications in medicine and material science.
Regioselective Glycosylation Strategies for the Synthesis of Group Ia and Ib Streptococcus Related Glycans Enable Elucidating Unique Conformations of the Capsular Polysaccharides
Authors: Del Bino Linda , Calloni Ilaria , Oldrini Davide , Raso Maria Michelina , Cuffaro Rossella , Ardá Ana , Codée Jeroen D. C. , Jiménez‐Barbero Jesús , Adamo Roberto 
Published: September 2019

AbstractGroup B Streptococcus serotypes Ia and Ib capsular polysaccharides are key targets for vaccine development. In spite of their immunospecifity these polysaccharides share high structural similarity. Both are composed of the same monosaccharide residues and differ only in the connection of the Neu5Acα2‐3Gal side chain to the GlcNAc unit, which is a β1‐4 linkage in serotype Ia and a β1‐3 linkage in serotype Ib. The development of efficient regioselective routes for GlcNAcβ1‐3[Glcβ1‐4]Gal synthons is described, which give access to different group B Streptococcus (GBS) Ia and Ib repeating unit frameshifts. These glycans were used to probe the conformation and molecular dynamics of the two polysaccharides, highlighting the different presentation of the protruding Neu5Acα2‐3Gal moieties on the polysaccharide backbones and a higher flexibility of Ib polymer relative to Ia, which can impact epitope exposure.
Preparation of an Anti‐Aggregation Silica/Zinc/Graphene Oxide Nanocomposite with Enhanced Adsorption Capacity
Authors: Yue Yajun , Cao Zhanfang , Yang Fan , Wang Jing , Abrahams Isaac 
Published: September 2019

AbstractNanomaterials play a significant role in adsorption treatment of dye wastewater, but irreversible aggregation of nanoparticles poses a significant problem. In this work, nanomesoporous zinc‐doped silicate (NMSZ) was prepared by an in situ method. To prevent agglomeration, NMSZ was covalently bonded to graphene oxide (GO) sheets to form a nano‐silica/zinc/graphene oxide composite (GO‐NMSZ), aimed at removal of cationic dye methylene blue (MB). For comparison, undoped mesoporous silica (MS) was also synthesized and modified to obtain a silica/graphene oxide composite (GO‐MS). The materials were characterized by powder XRD, SEM, FTIR spectroscopy, TEM, nitrogen sorption, and X‐ray photoelectron spectroscopy (XPS). Preservation of the oxygen‐containing groups of GO in the composites led to higher adsorption capacities. The best GO‐NMSZ composite exhibited an enhanced adsorption capacity of 100.4 mg g−1for MB compared to those of undoped GO‐MS (80.1 mg g−1) and nongrafted NMSZ (55.7 mg g−1). The nonselective character of GO‐NMSZ is demonstrated by effective adsorption of anionic dye Congo red (127.4 mg g−1) and neutral dye isatin (289.0 mg g−1). The adsorption kinetics, adsorption isotherms, and a thermodynamic study suggested that MB adsorption occurs by chemisorption and is endothermic in nature.
Catalytic‐Type Excited‐State N−H Proton‐Transfer Reaction in 7‐Aminoquinoline and Its Derivatives
Authors: Chang Kai‐Hsin , Liu Ying‐Hsuan , Liu Jiun‐Chi , Peng Yu‐Chiang , Yang Yu‐Hsuan , Li Zhi‐Bin , Jheng Ren‐Hua , Chao Chi‐Min , Liu Kuan‐Miao , Chou Pi‐Tai 
Published: September 2019

Abstract7‐Aminoquinoline (7AQ) and various amino derivatives thereof (‐NHR) have been strategically designed and synthesized to study their excited‐state proton‐transfer (ESPT) properties. Due to the large separation between the proton donor ‐NHR and the acceptor ‐N‐ site, ESPT in 7AQ derivatives, if available, should proceed under protic solvent catalysis. ESPT is found to be influenced by the acidity of ‐NHR and the basicity of the proton‐acceptor ‐N‐ in the quinoline moiety. The latter is varied by the resonance effect at the quinoline ‐N‐ site induced by the ‐NHR substituent. For those 7AQ derivatives undergoing ESPT, increased quinoline basicity results in a faster rate of ESPT, implying that proton donation from methanol to the quinoline moiety may serve as a key step in the process. Our studies also indicate the existence of an equilibrium between cis and trans arrangements of ‐NHR in terms of its hydrogen‐bond (H‐bond) configuration with methanol, whereby only the cis‐H‐bonded form undergoes methanol‐assisted ESPT. With one exception, the interconversion between cis and trans configurations is much faster than the rate of ESPT, yielding amino‐type (normal form) and imine‐type (proton‐transfer tautomer) emissions with distinct relaxation dynamics.
Decision tree model for predicting in‐hospital cardiac arrest among patients admitted with acute coronary syndrome
Authors: Li Hong , Wu Ting Ting , Yang Dong Liang , Guo Yang Song , Liu Pei Chang , Chen Yuan , Xiao Li Ping 
Published: September 2019

AbstractBackgroundIn‐hospital cardiac arrest (IHCA) may be preventable, with patients often showing signs of physiological deterioration before an event. Our objective was to develop and validate a simple clinical prediction model to identify the IHCA risk among cardiac arrest (CA) patients hospitalized with acute coronary syndrome (ACS).HypothesisA predicting model could help to identify the risk of IHCA among patients admitted with ACS.MethodsWe conducted a case‐control study and analyzed 21 337 adult ACS patients, of whom 164 had experienced CA. Vital signs, demographic, and laboratory data were extracted from the electronic health record. Decision tree analysis was applied with 10‐fold cross‐validation to predict the risk of IHCA.ResultsThe decision tree analysis detected seven explanatory variables, and the variables' importance is as follows: VitalPAC Early Warning Score (ViEWS), fatal arrhythmia, Killip class, cardiac troponin I, blood urea nitrogen, age, and diabetes. The development decision tree model demonstrated a sensitivity of 0.762, a specificity of 0.882, and an area under the receiver operating characteristic curve (AUC) of 0.844 (95% CI, 0.805 to 0.849). A 10‐fold cross‐validated risk estimate was 0.198, while the optimism‐corrected AUC was 0.823 (95% CI, 0.786 to 0.860).ConclusionsWe have developed and internally validated a good discrimination decision tree model to predict the risk of IHCA. This simple prediction model may provide healthcare workers with a practical bedside tool and could positively impact decision‐making with regard to deteriorating patients with ACS.
Results of a prospective phase 2 study of pazopanib in patients with surgically unresectable or metastatic chondrosarcoma
Authors: Chow Warren , Frankel Paul , Ruel Chris , Araujo Dejka M. , Milhem Mohammed , Okuno Scott , Hartner Lee , Undevia Samir , Staddon Arthur 
Published: September 2019

BackgroundThis single‐arm, multicenter, phase 2 study evaluated the safety and antitumor activity of pazopanib in patients with unresectable or metastatic conventional chondrosarcoma.MethodsEligible patients had conventional chondrosarcoma of any grade with measurable tumors that were unresectable or metastatic. Patients with mesenchymal, dedifferentiated, and extraskeletal myxoid chondrosarcoma subtypes and patients who received prior tyrosine kinase inhibitor therapy were excluded. Pazopanib at 800 mg once daily was administered for 28‐day cycles. Tumor responses were evaluated by local radiology assessments every 2 cycles. The primary endpoint was the disease control rate (DCR) at week 16 (4 cycles).ResultsForty‐seven patients were enrolled. The DCR at 16 weeks was 43% (95% confidence interval [CI], 28%‐58%), which was superior to the null hypothesis rate of 30%, but the 2‐sided P value (exact test) was .09 (1‐sided P = .045). One patient had a partial response. The median overall survival was 17.6 months (95% CI, 11.3‐35.0 months), and the median progression‐free survival was 7.9 months (95% CI, 3.7‐12.6 months). Grade 3 or higher adverse events were infrequent; hypertension (26%) and elevated alanine aminotransferase (9%) were most common.ConclusionsThis study provides evidence of positive drug activity for pazopanib in conventional chondrosarcoma.
Heterogeneity of p16 immunohistochemistry and increased sensitivity of RNA in situ hybridization in cytology specimens of HPV‐related head and neck squamous cell carcinoma
Authors: Wong Kristine S. , Krane Jeffrey F. , Jo Vickie Y. 
Published: September 2019

BackgroundMany patients with human papillomavirus (HPV)–related head and neck squamous cell carcinoma (HPV‐HNSCC) initially present with cervical lymph node metastases. Although p16 immunohistochemistry (IHC) is the most commonly used surrogate marker for HPV, however criteria in cytologic material are not well established. The objective of this study was to better characterize p16 IHC in cell blocks of metastatic HPV‐HNSCC, and to evaluate the performance of HPV RNA in situ hybridization (RNA ISH).Methodsp16 IHC was performed on cell blocks from 97 metastatic HPV‐HNSCC fine‐needle aspiration specimens with HPV status confirmed by DNA or RNA ISH or polymerase chain reaction (PCR). Tumor cellularity (<100 cells, 100‐500 cells, and >500 cells) and quality (presence of cell clusters, necrosis) were recorded. p16 staining intensity and extent (1%‐9%, 10%‐69%, and ≥70%) were scored. In addition, RNA ISH was performed on 38 PCR‐positive cases.Resultsp16 IHC was positive in 90 of 97 cases (93%), demonstrating variable patterns. p16 staining was found to be moderate to strong in 69 cases, with 37 cases (38%) demonstrating positivity in ≥70% of tumor cells. Weak staining occurred in 21 cases (22%) and 7 cases (7%) were negative. Of the 60 cases with weak and/or absent expression or staining in <70% of cells, 30 cases (50%) had <100 tumor cells, 12 (20%) lacked cell clusters, and 19 cases (32%) had extensive necrosis. RNA ISH was positive in 37 of 38 cases (97%) that were HPV positive by PCR.Conclusionsp16 is heterogeneous in cell blocks of metastatic HPV‐HNSCC, suggesting that any p16 positivity should prompt confirmatory HPV studies. RNA ISH appears to demonstrate high sensitivity, and laboratories even may consider using RNA ISH as a first‐line HPV test in cytologic specimens.
Mechanistic Insights into Cyclic Voltammograms on Pt(111): Kinetics Simulations
Authors: Shen Dongyan , Liu Yong , Yang Guangxing , Yu Hao , Peng Feng 
Published: September 2019

AbstractA detailed understanding of the electrochemistry of platinum electrodes is of great importance for the electrochemical oxidation of fuels and electrochemical reduction of dioxygen in fuel cells. The Pt(111) facet is the most representative model mimicking Pt nanoparticles and polycrystals for fundamental studies. Herein, we propose a site‐specific model accompanied with the typical elementary steps of the electrochemistry of Pt(111) in non‐adsorbing electrolyte within the potential range between 0.05 and 1.15 V versus reversible hydrogen electrode. Simulations were conducted at different scanning rates based on the kinetics models. We reproduce all the anodic and cathodic peaks observed in the reported experimental curves. These results demonstrate the underlying mechanisms of the peak formation in different potential regions.
A rail‐to‐rail ultra‐wide bandwidth hybrid supply modulator for 5G applications with envelope tracking techniques
Authors: Chen Jiann‐Jong , Hwang Yuh‐Shyan , Liao Ying‐Jie , Ku Yitsen , Yu Cheng‐Chieh 
Published: September 2019

SummaryA rail‐to‐rail ultra‐wide bandwidth hybrid supply modulator for 5G applications is presented in this paper. The proposed supply modulator has 600‐MHz bandwidth, which is the widest available bandwidth today. The hybrid supply modulator uses envelope tracking (ET) technique to achieve optimal efficiency. This circuit achieves high efficiency with wide bandwidth by combining the linear amplifier (LA) and the switching converter. The optimal size of the LA output stage provides a good tracking ability. The proposed hysteresis window circuit uses the simplified number of MOSFET that reduces the chip area and increases the efficiency of the overall system. This chip has been fabricated in TSMC 90‐nm CMOS processes, and the maximum tracking ability can reach to 600‐MHz sine wave. The output voltage range of the sine wave is from 0.19 to 0.79 V. The maximum load current is 122 mA. The proposed supply modulator is suitable for 5G applications. The chip area is 0.87 mm × 0.87 mm.
Inferring seasonal infection risk at population and regional scales from serology samples
Authors: Wilber Mark Q. , Webb Colleen T. , Cunningham Fred L. , Pedersen Kerri , Wan Xiu‐Feng , Pepin Kim M. 
Published: September 2019

AbstractAccurate estimates of seasonal infection risk can be used by animal health officials to predict future disease risk and improve understanding of the mechanisms driving disease dynamics. It can be difficult to estimate seasonal infection risk in wildlife disease systems because surveillance assays typically target antibodies (serosurveillance), which are not necessarily indicative of current infection, and serosurveillance sampling is often opportunistic. Recently developed methods estimate past time of infection from serosurveillance data using quantitative serological assays that indicate the amount of antibodies in a serology sample. However, current methods do not account for common opportunistic and uneven sampling associated with serosurveillance data. We extended the framework of survival analysis to improve estimates of seasonal infection risk from serosurveillance data across population and regional scales. We found that accounting for the right‐censored nature of quantitative serology samples greatly improved estimates of seasonal infection risk, even when sampling was uneven in time. Survival analysis can also be used to account for common challenges when estimating infection risk from serology data, such as biases induced by host demography and continually elevated antibodies following infection. The framework developed herein is widely applicable for estimating seasonal infection risk from serosurveillance data in humans, wildlife, and livestock.
Soil and stand structure explain shrub mortality patterns following global change–type drought and extreme precipitation
Authors: Renne Rachel R. , Schlaepfer Daniel R. , Palmquist Kyle A. , Bradford John B. , Burke Ingrid C. , Lauenroth William K. 
Published: September 2019

AbstractThe probability of extreme weather events is increasing, with the potential for widespread impacts to plants, plant communities, and ecosystems. Reports of drought‐related tree mortality are becoming more frequent, and there is increasing evidence that drought accompanied by high temperatures is especially detrimental. Simultaneously, extreme large precipitation events have become more frequent over the past century. Water‐limited ecosystems may be more vulnerable to these extreme events than other ecosystems, especially when pushed outside of their historical range of variability. However, drought‐related mortality of shrubs—an important component of dryland vegetation—remains understudied relative to tree mortality. In 2014, a landscape‐scale die‐off of the widespread shrub, big sagebrush (Artemisia tridentata Nutt.), was reported in southwest Wyoming, following extreme hot and dry conditions in 2012 and extremely high precipitation in September of 2013. Here we examine how severe drought, extreme precipitation, soil texture and salinity, and shrub‐stand characteristics contributed to this die‐off event. At 98 plots within and around the die‐off, we quantified big sagebrush mortality, characterized soil texture and salinity, and simulated soil‐water conditions from 1916 to 2016 using an ecosystem water‐balance model. We found that the extreme weather conditions alone did not explain patterns of big sagebrush mortality and did not result in extreme (historically unprecedented) soil‐water conditions during the drought. Instead, plots with chronically dry soil conditions experienced greatest mortality following the global change–type (hot) drought in 2012. Furthermore, mortality was greater in locations with high potential run‐on and low potential run‐off where saturated soil conditions were simulated in September 2013, suggesting that extreme precipitation also played an important role in the die‐off in these locations. In locations where drought alone contributed to mortality, stem density negatively impacted big sagebrush. In locations that may have been affected by both drought and saturation, however, mortality was greatest where stem density was lowest, suggesting that these locations may have already been less favorable to big sagebrush. Paradoxically, vulnerability to both extreme events (drought and saturation) was associated with finer‐textured soils, and our results highlight the importance of soils in determining local variation of the vulnerability of dryland plants to extreme events.
Insights in the anode chamber influences on cathodic bioelectromethanogenesis – systematic comparison of anode materials and anolytes
Authors: Enzmann Franziska , Stöckl Markus , Gronemeier Denise , Holtmann Dirk 
Published: September 2019

AbstractCathode and catholyte are usually optimized to improve microbial electrosynthesis process, whereas the anodic counter reaction was not systematically investigated and optimized for these applications yet. Nevertheless, the anolyte and especially the anode material can limit the cathodic bioelectrochemical process. This paper compares for the first time the performance of different anode materials as counter electrodes for a cathodic bioelectrochemical process, the bioelectromethanogenesis. It was observed that depending on the anode material the cathodic methane production varies from 0.96 µmol/d with a carbon fabric anode to 25.44 µmol/d with a carbon felt anode of the same geometrical surface area. The used anolyte also affected the methane production rate at the cathode. Especially, the pH of the anolyte showed an impact on the system; an anolyte with pH 5 produced up to 2.0 times more methane compared to one with pH 8.5. The proton availability is discussed as one reason for this effect. Although some of the measured effects cannot be explained completely so far this study advises researchers to strongly consider the anode impact during process development and optimization of a cathodic bioelectrochemical synthesis process.
Robust decision making and scenario discovery in the absence of formal models
Authors: Popper Steven W. 
Published: September 2019

AbstractRobust decision making (RDM) is a method for aiding decision making under deep uncertainty that uses models not as predictors but as generators of cases exploring assumptions and outcomes. RDM was intended for use with formal models. However, we show a model‐less RDM application to a portfolio planning problem (selecting U.S. Army security cooperation activities with a partner country) seeking to achieve several objectives. In the absence of formal models, the analysis tests candidate actions against different explicit statements of causal relationships to allow more systematic reasoning over choices and outcomes. Doing so renders assumptions about complex systems explicit, characterizes uncertainties in terms of effect on weighting policy choices rather than as presently unknowable probabilities, provides a venue for planners and evaluators to share findings and insights, and yields explicit expressions of theories of causation (TOC) that themselves act as formal models where none had previously existed. RDM allows important scenarios for decision planning to be generated analytically. This may address for several scenario applications the question of determining important futures and also how scenario results may be used directly to inform policy and operational decisions.
The neural basis of semantic cognition in Mandarin Chinese: A combined fMRI and TMS study
Authors: Zhang Qian , Wang Hui , Luo Cimei , Zhang Junjun , Jin Zhenlan , Li Ling 
Published: September 2019

AbstractWhile converging sources of evidence point to the possibility of a large‐scale distributed network for semantic cognition, a consensus regarding the underlying subregions and their specific function in this network has not been reached. In the current study, we combined functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) methodology to investigate the neural basis of semantic cognition in Mandarin Chinese. In the fMRI experiment, strong activations were observed in left inferior frontal gyrus (IFG) and left middle temporal gyrus (MTG) for semantic judgment task. Moreover, functional connectivity was found from seed region left IFG to left MTG. Meanwhile, negative correlation between performance and extracted parameter estimates from left IFG to left MTG was detected in semantic task. Subsequent TMS stimulation over left IFG resulted in performance deficits in semantic judgment task, in contrast to other three sites: left MTG, right intraparietal sulcus (IPS) and a control site. We concluded that the neural basis of semantic processing for Mandarin Chinese closely resembled that for alphabetic languages such as English, supporting a language‐universal view on semantic cognition.
Reporting gaps between news media and scientific papers on outdoor air pollution–related health outcomes: A content analysis
Authors: Sun Zhuanlan , Cang Jun , Ruan Yuhui , Zhu Demi 
Published: September 2019

SummaryObjectivesIn China, news media are useful for educating the public about the health threats of air pollution. To explore the potential gaps between scientific findings and the public's understanding of them, the characteristics of news media articles and their corresponding scientific papers were analysed.MethodsWe used 22 articles relating to the health outcomes of exposure to outdoor air pollution published on Baidu News over the past year. An assessment tool developed by Robinson et al was used to evaluate the quality scores of news articles. Pearson correlation coefficients were used to measure the relationship between news media reporting and the characteristics of scientific papers. Misleading reporting, interpretation, or extrapolation in headlines and text bodies of news articles were examined.ResultsThe quality scores of the news articles ranged from −4 to 8, with an overall median score of 3. Correlation results showed that the scientific papers citation in Twitter (r = .88, P < .001) and Facebook (r = .64, P < .01) were significantly and positively associated with their citations in news stories. Media misunderstanding of scientific findings was common: 15 news headlines were identified with at least one spin (misrepresentation of scientific results), and 12 news articles had seven types of spin in the body texts.ConclusionLittle media attention has been paid to scientific findings by Chinese researchers. Therefore, researchers and science journalists in China should make a better effort to engage in accurate and informative public discourse on domestic research.