bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stereoselective oxidative glycosylation of anomeric nucleophiles with alcohols and carboxylic acids
Authors: Yang Tianyi , Zhu Feng , Walczak Maciej A. 
Published: September 2018

AbstractOligosaccharides, one of the most abundant biopolymers, are involved in numerous biological processes. Although many efforts have been put in preparative carbohydrate chemistry, achieving optimal anomeric and regioselectivities remains challenging. Herein we describe an oxidative glycosylation method between anomeric stannanes and oxygen nucleophiles resulting in the formation of a C−O bond with consistently high anomeric control for glycosyl donors bearing a free C2-hydroxyl group. These reactions are promoted by hypervalent iodine reagents with catalytic or stoichiometric amounts of Cu or Zn salts. The generality of this transformation is demonstrated in 42 examples. Mechanistic studies indicate that the oxidative glycosylation is initiated by the hydroxyl-guided delivery of the hypervalent iodine and tosylate into the anomeric position, and results in excellent 1,2-trans selectivity. The unique mechanistic paradigm, high selectivities, and mild reaction conditions make this method suitable for the synthesis of oligosaccharides and for integration with other methodologies such as automated synthesis.
Compartmentalised RNA catalysis in membrane-free coacervate protocells
Authors: Drobot Björn , Iglesias-Artola Juan M. , Le Vay Kristian , Mayr Viktoria , Kar Mrityunjoy , Kreysing Moritz , Mutschler Hannes , Tang T-Y Dora 
Published: September 2018

AbstractPhase separation of mixtures of oppositely charged polymers provides a simple and direct route to compartmentalisation via complex coacervation, which may have been important for driving primitive reactions as part of the RNA world hypothesis. However, to date, RNA catalysis has not been reconciled with coacervation. Here we demonstrate that RNA catalysis is viable within coacervate microdroplets and further show that these membrane-free droplets can selectively retain longer length RNAs while permitting transfer of lower molecular weight oligonucleotides.
Sub-2 Å Ewald curvature corrected structure of an AAV2 capsid variant
Authors: Tan Yong Zi , Aiyer Sriram , Mietzsch Mario , Hull Joshua A. , McKenna Robert , Grieger Joshua , Samulski R. Jude , Baker Timothy S. , Agbandje-McKenna Mavis , Lyumkis Dmitry 
Published: September 2018

AbstractSingle-particle cryogenic electron microscopy (cryo-EM) provides a powerful methodology for structural biologists, but the resolutions typically attained with experimentally determined structures have lagged behind microscope capabilities. Here, we exploit several technical advances to improve resolution, including per-particle contrast transfer function (CTF) refinement and correction for Ewald sphere curvature. The latter is demonstrated with several experimental samples and should become more standard as resolutions increase or at lower microscope accelerating voltages. The combined application of the described methods to micrographs recorded on a Titan Krios enables structure determination at ~1.86-Å resolution of an adeno-associated virus serotype 2 variant (AAV2), an important gene-delivery vehicle. The resulting structural details provide an improved model for understanding the biology of AAV that will guide future vector development for gene therapy.
Height at three months can indicate overweight at two years in catch-up growth of small for gestational age infants
Authors: Chen Shi , Liu Zeyu , Zhu Huijuan , Yang Hongbo , Gong Fengying , Wang Linjie , Jiang Yu , Yan Chengsheng , Li Jianqiang , Wang Qing , Pan Hui 
Published: September 2018

AbstractThis study aimed to find an indicator at three months to predict overweight and short stature at two years in small for gestational age (SGA) infants. A total of 468 SGA infants and 4642 appropriate for gestational age (AGA) infants were included. Weight and height were measured at birth, three months and two years. Logistic regression and receiver operating characteristic (ROC) curves were performed for the catch-up growth. As compared to AGA infants, the weight of SGA infants was lower and the length/height was shorter at birth, three months, and two years. The weight of the catch-up group was significantly greater at birth and two years. The length/height of the catch-up group was greater at three months and two years. Trajectories of weight standard deviation score (SDS) and height SDS showed that the overweight group (BMI over the 85th percentile) had a shorter length/height SDS but a higher rate of the change in weight SDS during catch-up growth. The multivariate logistic regression indicated that that height at three months was an independent factor for prediction of catch-up growth at two years. The area under curve (AUC) was 0.801 with the 95% confidence interval (CI) from 0.726 to 0.876. Therefore, height at three months can predict overweight at two years.
Hydrological interactions between oases and water vapor transportation in the Tarim Basin, northwestern China
Authors: Zhou Xiangyang , Lei Wenjuan 
Published: September 2018

AbstractThe spatial evolution of the oasis cold-wet effects in Tarim Basin, northwestern China, are explored quantitatively by using the China Meteorological Forcing Dataset, with spatial and temporal resolution of 0.1 degree and 3 hours, respectively, and the hydrological interactions between the oases and water vapor transfer are discussed to uncover the influence of oases on regional precipitation. The results reveal that the annual precipitation exhibits an increasing trend from desert toward oasis at all four oases. However, the cold effect is not the dominating factor increasing precipitation, since the maximum increasing rate of precipitation is accompanied by the minimum decreasing rate of temperature. Indeed, water vapor transportation is more important than the cold effect. The maximum promotion of precipitation is observed in western basin, where the water vapor transfer follows the gradients of decreasing temperature and increasing humidity. Conversely, the minimum promotion in southwestern basin results from water vapor transportation following the temperature increasing. Therefore, the transfer of water vapor and its interactions with local surface conditions determine the precipitation in oasis areas. Understanding these processes is crucial to exploring the formation and spatial layout of oases, which is helpful for preventing desertification and protecting the fragile oasis ecosystem.
Differential effects of dietary fibres on colonic barrier function in elderly individuals with gastrointestinal symptoms
Authors: Ganda Mall J. P. , Löfvendahl L. , Lindqvist C. M. , Brummer R. J. , Keita Å. V. , Schoultz I. 
Published: September 2018

AbstractGastrointestinal problems are common in elderly and often associated with psychological distress and increased levels of corticotrophin-releasing hormone, a hormone known to cause mast cell (MC) degranulation and perturbed intestinal barrier function. We investigated if dietary fibres (non-digestible polysaccharides [NPS]) could attenuate MC-induced colonic hyperpermeability in elderly with gastrointestinal (GI) symptoms. Colonic biopsies from elderly with diarrhoea and/or constipation (n = 18) and healthy controls (n = 19) were mounted in Ussing chambers and pre-stimulated with a yeast-derived beta (β)-glucan (0.5 mg/ml) or wheat-derived arabinoxylan (0.1 mg/ml) before the addition of the MC-degranulator Compound (C) 48/80 (10 ng/ml). Permeability markers were compared pre and post exposure to C48/80 in both groups and revealed higher baseline permeability in elderly with GI symptoms. β-glucan significantly attenuated C48/80-induced hyperpermeability in elderly with GI symptoms but not in healthy controls. Arabinoxylan reduced MC-induced paracellular and transcellular hyperpermeability across the colonic mucosa of healthy controls, but did only attenuate transcellular permeability in elderly with GI symptoms. Our novel findings indicate that NPS affect the intestinal barrier differently depending on the presence of GI symptoms and could be important in the treatment of moderate constipation and/or diarrhoea in elderly.
Deciphering evolutionary dynamics of SWEET genes in diverse plant lineages
Authors: Li Xiaoyu , Si Weina , Qin QianQian , Wu Hao , Jiang Haiyang 
Published: September 2018

AbstractSWEET/MtN3/saliva genes are prevalent in cellular organisms and play diverse roles in plants. These genes are widely considered as evolutionarily conserved genes, which is inconsistent with their extensive expansion and functional diversity. In this study, SWEET genes were identified from 31 representative plant species, and exhibited remarkable expansion and diversification ranging from aquatic to land plants. Duplication detection indicated that the sharp increase in the number of SWEET genes in higher plants was largely due to tandem and segmental duplication, under purifying selection. In addition, phylogeny reconstruction of SWEET genes was performed using the maximum-likelihood (ML) method; the genes were grouped into four clades, and further classified into 10 monocot and 11 dicot subfamilies. Furthermore, selection pressure of SWEET genes in different subfamilies was investigated via different strategies (classical and Bayesian maximum likelihood (Datamonkey/PAML)). The average dN/dS for each group were lower than one, indicating purifying selection. Individual positive selection sites were detected within 4 of the 21 sub-families by both two methods, including two monocot subfamilies in Clade III, harboring five rice SWEET homologs characterized to confer resistance to rice bacterial blight disease. Finally, we traced evolutionary fate of SWEET genes in clade III for functional characterization in future.
Comparative transcriptome analysis to identify putative genes involved in thymol biosynthesis pathway in medicinal plant Trachyspermum ammi L.
Authors: Soltani Howyzeh Mehdi , Sadat Noori Seyed Ahmad , Shariati J. Vahid , Amiripour Mahboubeh 
Published: September 2018

AbstractThymol, as a dietary monoterpene, is a phenol derivative of cymene, which is the major component of the essential oil of Trachyspermum ammi (L.). It shows multiple biological activities: antifungal, antibacterial, antivirus and anti-inflammatory. T. ammi, commonly known as ajowan, belongs to Apiaceae and is an important medicinal seed spice. To identify the putative genes involved in thymol and other monoterpene biosynthesis, we provided transcriptomes of four inflorescence tissues of two ajowan ecotypes, containing different thymol yield. This study has detected the genes encoding enzymes for the go-between stages of the terpenoid biosynthesis pathways. A large number of unigenes, differentially expressed between four inflorescence tissues of two ajowan ecotypes, was revealed by a transcriptome analysis. Furthermore, differentially expressed unigenes encoding dehydrogenases, transcription factors, and cytochrome P450s, which might be associated with terpenoid diversity in T. ammi, were identified. The sequencing data obtained in this study formed a valuable repository of genetic information for an understanding of the formation of the main constituents of ajowan essential oil and functional analysis of thymol-specific genes. Comparative transcriptome analysis led to the development of new resources for a functional breeding of ajowan.
Neuroinflammatory Nexus of Pediatric Epilepsy
Authors: Bagla Shruti , Dombkowski Alan 
Published: September 2018

AbstractA rapidly growing body of evidence supports the premise that neuroinflammation plays an important role in initiating and sustaining seizures in a range of pediatric epilepsies. Clinical and experimental evidence indicates that neuroinflammation is both an outcome and a contributor to seizures. In this manner, seizures that arise from an initial insult (e.g., infection, trauma, and genetic mutation) contribute to an inflammatory response that subsequently promotes recurrent seizures. This cyclic relationship between seizures and neuroinflammation has been described as a “vicious cycle.” Studies of human tissue resected for surgical treatment of refractory epilepsy have reported activated inflammatory and immune signaling pathways, while animal models have been used to demonstrate that key inflammatory mediators lead to increased seizure susceptibility. Further characterization of the molecular mechanisms involved in this cycle may ultimately enable the development of new therapeutic approaches for the treatment of epilepsy. In this brief review, we focus on key inflammatory mediators that have become prominent in recent literature of epilepsy, including newly characterized microRNAs and their potential role in neuroinflammatory signaling.
Placeboeffekte in der Akutschmerztherapie
Authors: Haaga Roland , Schnabel Alexander 
Published: September 2018

ZusammenfassungPlacebo- und Noceboeffekte stehen aktuell sehr im Fokus der klinischen und experimentellen Schmerzforschung. Neuro- sowie psychophysiologische Prozesse scheinen eine wichtige Rolle bei der Entstehung sowie Vermittlung zu spielen. So werden Placebo- und Noceboeffekte im Wesentlichen über das Netzwerk des opioidergen, absteigenden, schmerzmodulierenden Systems vermittelt. Für das Zustandekommen eines Placeboeffektes wiederum werden 3 psychologische Mechanismen verantwortlich gemacht: klassische Konditionierung, soziales Lernen sowie die Schmerzerwartung. Eine offene Analgetikagabe, eine ausführliche Aufklärung über Wirkung und Nebenwirkung (ohne diese zu sehr in den Fokus zu stellen) der im perioperativen Bereich eingesetzten Medikamente und Interventionen sowie eine Einbindung des Patienten in die Therapie (z. B. durch patientenkontrollierte Systeme) können zu einer additiven Verbesserung der Akutschmerztherapie (bis zu 30%) führen.
Grammatical structures and oral fluency in immediate task repetition
Authors: de Jong Nel , Tillman Philip 
Published: September 2018

Abstract
In this study we examine to what extent words and grammatical structures are re-used when a speaking task is repeated with the same content (i.e., specific task repetition). We examine this re-use, which has been argued to support proceduralization and fluency development (N. de Jong & Perfetti, 2011), under both constant and increasing time pressure, and we investigate the correlation between re-use and fluency. The analyses are performed not only on individual words but also on trigrams, which are sequences of three words (e.g., the red car; here: lexical trigrams) or three parts of speech (e.g., det adj noun: POS trigrams), to capture grammatical structure. Thirty-nine adult ESL speakers completed repeated retellings of one to three picture stories. One group followed the 4/3/2 procedure (Nation, 1989), which involves three iterations with gradually increasing time pressure; for the other group the available time was constant. The extent of re-use of words and grammatical structures across task iterations was calculated using cosine similarity with tf-idf weighting (Manning, Raghavan, & Schütze, 2008), which adjusts for the frequency of words or trigrams, both within an iteration and across iterations and speakers. It was found that immediate task repetition had a strong effect on re-use at the level of individual words and trigrams, but increasing time pressure did not. The relationship between re-use and fluency was variable, but showed higher re-use for speakers struggling with fluency. We conclude that, if fluency development is to be stimulated by re-use of words and grammatical structures, it can be done with specific task repetition, whether under increasing time pressure or not.
The effects of task repetition and task complexity on L2 lexicon use
Authors: Kim YouJin , Crossley Scott A. , Jung YeonJoo , Kyle Kristopher , Kang Sanghee 
Published: September 2018

Abstract
To date, a growing number of studies in instructed second language acquisition (SLA) have investigated the effects of task repetition on L2 performance (e.g., complexity, accuracy, fluency) as well as on the occurrence of interaction-driven learning opportunities (e.g., Bygate, 2001; Fukuta, 2016; Kim & Tracy-Ventura, 2013). However, studies have not investigated how repeating different aspects of tasks (e.g., content or procedure) during collaborative tasks affects second language lexical use. The current study aims to fill that gap by comparing the impact of procedural repetition and task repetition on the lexical use of paired language learners as they repeat collaborative tasks. Furthermore, how task complexity mediates task repetition effects was also investigated. Four intact junior high school English classes (n = 73) were randomly assigned to one of the following groups: (1) simple task with exact task repetition, (2) simple task with procedural repetition, (3) complex task with exact task repetition, and (4) complex task with procedural repetition. All groups participated in three collaborative tasks over three days. The task repetition groups carried out the same information-exchange task with the same content three times, while the procedural repetition groups followed the same task procedure but had different content for the three sessions. Learners’ interaction data during collaborative tasks were transcribed and analyzed for lexical use using a natural language processing tool. Lexical use was operationalized by word familiarity, age of acquisition (AoA), and word frequency (Kyle & Crossley, 2015). The findings indicated that as learners repeated tasks, they used words that are less familiar and have a higher age of acquisition. Task complexity was found to be a mediating factor for the relationship between task repetition and vocabulary use.
The Neuroanatomy of Autism Spectrum Disorder Symptomatology in 22q11.2 Deletion Syndrome
Authors: Gudbrandsen M , Daly E , Murphy C M , Wichers R H , Stoencheva V , Perry E , Andrews D , Blackmore C E , Rogdaki M , Kushan L , Bearden C E , Murphy D G M , Craig M C , Ecker C 
Published: September 2018

Abstract
22q11.2 Deletion Syndrome (22q11.2DS) is a genetic condition associated with a high prevalence of neuropsychiatric conditions that include autism spectrum disorder (ASD). While evidence suggests that clinical phenotypes represent distinct neurodevelopmental outcomes, it remains unknown whether this translates to the level of neurobiology. To fractionate the 22q11.2DS phenotype on the level of neuroanatomy, we examined differences in vertex-wise estimates of cortical volume, surface area, and cortical thickness between 1) individuals with 22q11.2DS (n = 62) and neurotypical controls (n = 57) and 2) 22q11.2DS individuals with ASD symptomatology (n = 30) and those without (n = 25). We firstly observed significant differences in surface anatomy between 22q11.2DS individuals and controls for all 3 neuroanatomical features, predominantly in parietotemporal regions, cingulate and dorsolateral prefrontal cortices. We also established that 22q11.2DS individuals with ASD symptomatology were neuroanatomically distinct from 22q11.2DS individuals without ASD symptoms, particularly in brain regions that have previously been linked to ASD (e.g., dorsolateral prefrontal cortices and the entorhinal cortex). Our findings indicate that different clinical 22q11.2DS phenotypes, including those with ASD symptomatology, may represent different neurobiological subgroups. The spatially distributed patterns of neuroanatomical differences associated with ASD symptomatology in 22q11.2DS may thus provide useful information for patient stratification and the prediction of clinical outcomes.
Exploring what teams perceive by ‘culture’ when implementing new models of care
Authors: Bull Eleanor Rose , Byrne-Davis Lucie Marie Theresa , Swift Juliette , Baxter Kirstie , McLauchlan Neil , Hart Joanne Karen 
Published: September 2018

Abstract

Introduction
Health and social care organizations continually face change to coordinate efforts, improve care quality and better meet patient needs in the context of growing pressure on services. NHS ‘vanguard’ teams funded to pilot organizational change in England have argued that alongside new structures, policies and governance, a shift in ‘workplace culture’ is needed to implement change. Although now defined in the literature and seen as an important driver of quality care, it was not clear what teams themselves meant when discussing workplace culture.

Methods
In a qualitative study nested in a wider behavioural science programme, 34 managers and frontline NHS staff took part in interviews and focus groups on the role and meaning of ‘workplace culture’ in their experience of change. Participants were from organizations in four NHS England vanguards implementing new models of care. Inductive thematic analysis revealed six interlinking themes: unity, emotions, support, consistency, openness to innovation and performance.

Results
The term ‘workplace culture’ was nuanced and used in various ways. It was seen as a determinant, measure and/or consequence of change and linked to workplace behaviours, emotions and cognitions. Participants agreed that imposed top-down change in new models of care was a common cause of damaged culture and had knock-on effects on care quality, despite manager accounts of the importance of staff ideas.

Discussion
Our findings suggest that exploring teams’ own meanings of culture and behaviour change barriers, gathering ideas and co-developing tailored support would help overcome cultural challenges in implementing new models of care.
Placing our current ‘hyperthermal’ in the context of rapid climate change in our geological past
Authors: Foster Gavin L. , Hull Pincelli , Lunt Daniel J. , Zachos James C. 
Published: September 2018

‘…there are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know.’ Donald Rumsfeld 12th February 2002.This article is part of a discussion meeting issue ‘Hyperthermals: rapid and extreme global warming in our geological past’.
Overcoming systematic errors caused by log-transformation of normalized single-cell RNA sequencing data
Authors: Lun Aaron 
Published: September 2018

AbstractApplying a log-transformation to normalized expression values is one of the most common procedures in exploratory analyses of single-cell RNA sequencing (scRNA-seq) data. Normalization removes systematic biases in sequencing coverage between cells, while the log-transformation ensures that downstream computational procedures operate on relative rather than absolute differences in expression. We show that the log-transformation can introduce systematic errors when cells vary in sequencing coverage, leading to spurious non-zero differences in expression and artificial population structure in simulations. We observe similar effects in real scRNA-seq data where the difference in transformed values between groups of cells is not an accurate proxy for the log-fold change. We provide some practical recommendations to overcome this effect and analytically derive an expression for a larger pseudo-count that controls the transformation-induced error to a specified threshold.