bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting the Limit of Intramolecular Hydrogen Bonding with Classical Molecular Dynamics
Authors: Colizzi Francesco , Hospital Adam , Zivanovic Sanja , Orozco Modesto 
Published: January 2019

AbstractThe energetics of intramolecular recognition processes are governed by the balance of pre‐organization and flexibility, which is often difficult to measure and hard to predict. Using classical MD simulations, we predict and quantify the effective strength of intramolecular hydrogen bonds between donor and acceptor sites separated by a variable alkyl linker in several solvents and crowded solutions. The balance of entropic and enthalpic contributions poses a solvent‐dependent limit to the occurrence of intramolecular H‐bonding. Still, free energies show a constant offset among different solvents with, for example, a 13 kJ mol−1 difference between water and chloroform. Molecular crowding shows little effect on the thermodynamic equilibrium, but induces variations on the H‐bond kinetics. The results are in quantitative agreement with experiments in chloroform and showcase a general strategy to investigate molecular interactions in different environments, extending the limits of current experiments towards the prospective prediction of H‐bond interactions in a variety of contexts.
Promoting the Outgrowth of Neurites on Electrospun Microfibers by Functionalization with Electrosprayed Microparticles of Fatty Acids
Authors: Xue Jiajia , Wu Tong , Li Jianhua , Zhu Chunlei , Xia Younan 
Published: January 2019

AbstractControlling the outgrowth of neurites is important for enhancing the repair of injured nerves and understanding the development of nervous systems. Herein we report a simple strategy for enhancing the outgrowth of neurites through a unique integration of topographical guidance and a chemical cue. We use electrospray to easily functionalize the surface of a substrate with microparticles of natural fatty acids at a controllable density. Through a synergistic effect from the surface roughness arising from the microparticles and the chemical cue offered by the fatty acids, the outgrowth of neurites from PC12 cells is greatly enhanced. We also functionalize the surfaces of uniaxially aligned, electrospun microfibers with the microparticles and further demonstrate that the substrates can guide and enhance directional outgrowth of neurites from both PC12 multicellular spheroids and chick embryonic dorsal root ganglia bodies.
Migratory Shift in Oxidative Cyclodehydrogenation Reaction of Tetraphenylethylenes Containing Electron‐Rich THDTAP Moiety
Authors: Wu Yuewei , Yan Chaoxian , Li Dongxu , Yuan Chengshan , Sun Jibin , Zhou Shuyun , Zhang Hao‐Li , Shao Xiangfeng 
Published: January 2019

AbstractFour tetraphenylethylenes (2 a–d) containing an electron‐rich 2,3,4,6‐tetrahydro‐1,6‐dithia‐3a‐azaphenalene (THDTAP) moiety have been synthesized. The 2 a–d show aggregation‐induced emission (AIE) with yellowish green photoluminescence (PL) in THF‐H2O (v/v, 1:9) solution and in the solid state. Compounds 2 a–d undergo 1,2‐migratory shift in oxidative cyclodehydrogenation reactions to afford the unexpected products 3 a–d which display green PL in CH2Cl2 solution and are non‐emissive in the solid state. The PL intensities of 3 a–d are clearly enhanced in the presence of meta‐chloroperoxybenzoic acid (mCPBA) owing to the oxidation of the S‐atoms on the THDTAP moiety. In contrast, the PL of 2 a–d in THF‐H2O (v/v, 1:9) solution is quenched by adding mCPBA, ascribable to the oxidation of the C=C bond on the ethylene moiety. It is found that the absorption of 3 a–d is distinctly red‐shifted from the UV/Vis region to the NIR region upon acidification, arising from the protonation of the N‐atom on the THDTAP moiety. Furthermore, 3 a–d display nonlinear optical response (NLO) and optical limiting (OL) behaviour which is superior to that of the well‐known OL material C60.
Making Solid‐Phase Peptide Synthesis Greener: A Review of the Literature
Authors: Varnava Kyriakos G. , Sarojini Vijayalekshmi 
Published: January 2019

AbstractTo date, the synthesis of peptides is concurrent with the production of enormous amounts of toxic waste. DMF, CH2Cl2, and NMP are three of the most toxic organic solvents used in chemical synthesis and are the most common solvents used for peptide synthesis. Additionally, concerns about the hepatotoxicity caused by exposure to DMF and from the toxic and allergenic nature of additives used in peptide synthesis necessitates the need for a green, environmentally friendly, and safer protocol for peptide synthesis. This review summarizes the current literature on green solid‐phase peptide synthesis successes and challenges encountered. The review concludes with suggestions for future research towards a simple and efficient green peptide synthesis protocol.
Association between CNTNAP2 polymorphisms and autism: A family‐based study in the chinese han population and a meta‐analysis combined with GWAS data of psychiatric genomics consortium
Authors: Zhang Tian , Zhang Jishui , Wang Ziqi , Jia Meixiang , Lu Tianlan , Wang Han , Yue Weihua , Zhang Dai , Li Jun , Wang Lifang 
Published: January 2019

Autism is a childhood neuropsychiatric disorder with evidence of a strong genetic component in the complex etiologies. Contactin‐associated protein‐like 2 (CNTNAP2), a member of the neurexin superfamily, plays an essential role in neural development. CNTNAP2 was considered as one of the most susceptible genes for autism spectrum disorder (ASD). Some studies indicated the association of CNTNAP2 with ASD, while others reported no association. Given the inconsistent results of the previous studies, we performed a family‐based association study between 9 single‐nucleotide polymorphisms (SNPs) of CNTNAP2 and autism in 640 autistic trios in the Chinese Han population. Then, an updated meta‐analysis, combined with the data from Psychiatric Genomics Consortium (iPSYCH‐PGC ASD, 2017) and available association studies, was conducted. No SNPs were significantly associated with autism in the Chinese Han population. In the meta‐analysis, the two frequently reported SNPs (rs2710102 and rs7794745) showed no significant association with ASD. Therefore, CNTNAP2 polymorphisms might not be associated with autism. Autism Research 2019, 12: 553–561. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryIn present family‐based association study, no single‐nucleotide polymorphisms (SNPs) were significantly associated with autism in the Chinese Han population. In the updated meta‐analysis, the association between the two frequently reported SNPs (rs2710102 and rs7794745) in CNTNAP2 and the risk of ASD was explored. However, the results showed no significant association. Therefore, our study suggested that CNTNAP2 polymorphisms might not be associated with autism.
Women's periconceptional lowered carbohydrate intake and NTD‐affected pregnancy risk in the era of prefortification with folic acid
Authors: Shaw Gary M. , Yang Wei 
Published: January 2019

BackgroundA recent study observed women's restricted carbohydrate diet in the year before conception was associated with increased risk of neural tube defect (NTD)‐affected pregnancies. That study corresponded to the era of postfortification of folic acid. Because folic acid and carbohydrate measures would derive from similar foods, investigators of that study could not determine whether the increased risk with restricted carbohydrate intake was a consequence of lower folate intake. We extend their novel observation by examining rigorous NTD data prior to folic acid fortification.MethodsData were derived from a population‐based case–control study of fetuses and infants with NTDs among 1989–1991 California births. Interviews were conducted with mothers of 449 NTD cases and with mothers of 458 nonmalformed controls. A standard 100‐item food frequency questionnaire was used to assess macro‐ and micronutrient intakes based on reported intakes 3 months before conception.ResultsCase mothers were twice as likely to have consumed a low carbohydrate (≤5th percentile intake among controls) diet with a crude odds ratio of 2.0 (95% confidence interval, 1.2–3.4). Adjustment for race/ethnicity, education, alcohol intake, and folic acid use made very little difference on the odds ratio. Adjustment for total energy intake appeared to be the only factor to slightly attenuate the odds ratio.ConclusionOur findings indicate that the association between low carbohydrate intake and NTD risk may not be wholly a function of low folic acid in the postfortification era. Such a finding offers new clues to pursue for the seemingly folate‐insensitive NTDs that continue to occur.
High quantum yield and well‐dispersed quantum dots luminescent composite through sodium carboxymethyl starch
Authors: Liu Cui , Liu Yang , Deng Heming , Tang Shun , Cao Yuan‐Cheng 
Published: January 2019

AbstractIt is a challenging task to prepare well‐dispersed and highly luminescent quantum dots (QDs) powder and a new strategy is reported in this article. Sodium carboxymethyl starch (CMS‐Na) was employed in this work to prepare the QDs–starch composite. Ultraviolet (UV) light shows that the blank starches had no fluorescence, while the QDs‐starches were highly luminescent. Scanning electron microscopy (SEM) observation shows that the QDs–starch composite has the typical particle morphology with the diameter around 200 nm. Energy dispersive X‐ray spectroscopy (EDX) results show that there are intensive tellurium (Te) and cadmium (Cd) element signals. Combined fluorescent lifetime and steady‐state spectrometer show that the QDs–starch quantum yields (QYs) increase when the QDs loading increases from 1 × 10−6 mol/g to 2 × 10−6 mol/g, but when the loadings further increase, the QYs decrease slightly. For the red colour (λem = 660 nm) QDs, the QYs can reach to as high as 28.2%, and for the other colour QDs they can also have the QYs above 22%. Time‐resolved photobleaching experiments show that the fluorescent QDs–starch composite has a half‐decay time of 40.23 s. These results indicate that the CMS‐Na is a promising QDs dispersant to obtain high QY QD composites.
Synergistic Surface Passivation of CH3NH3PbBr3 Perovskite Quantum Dots with Phosphonic Acid and (3‐Aminopropyl)triethoxysilane
Authors: Xu Ke , Vickers Evan T. , Rao Longshi , Lindley Sarah A. , Allen A'Lester C. , Luo Binbin , Li Xueming , Zhang Jin Zhong 
Published: January 2019

AbstractCH3NH3PbBr3 perovskite quantum dots (PQDs) are synthesized by using four different linear alkyl phosphonic acids (PAs) in conjunction with (3‐aminopropyl)triethoxysilane (APTES) as capping ligands. The resultant PQDs are characterized by means of XRD, TEM, Raman spectroscopy, FTIR spectroscopy, UV/Vis, photoluminescence (PL), time‐resolved PL, and X‐ray photoelectron spectroscopy (XPS). PA chain length is shown to control the PQD size (ca. 2.9–4.2 nm) and excitonic absorption band positions (λ=488–525 nm), with shorter chain lengths corresponding to smaller sizes and bluer absorptions. All samples show a high PL quantum yield (ca. 46–83 %) and high PL stability; this is indicative of a low density of band gap trap states and effective surface passivation. Stability is higher for smaller PQDs; this is attributed to better passivation due to better solubility and less steric hindrance of the shorter PA ligands. Based on the FTIR, Raman, and XPS results, it is proposed that Pb2+ and CH3NH3+ surface defects are passivated by R−PO32− or R−PO2(OH)−, whereas Br− surface defects are passivated by R−NH3+ moieties. This study establishes the combination of PA and APTES ligands as a highly effective dual passivation system for the synergistic passivation of multiple surface defects of PQDs through primarily ionic bonding.
Weak Pnictogen Bond with Bismuth: Experimental Evidence Based on Bi−P Through‐Space Coupling
Authors: Mokrai Réka , Barrett Jamie , Apperley David C. , Batsanov Andrei S. , Benkő Zoltán , Heift Dominikus 
Published: January 2019

AbstractTo study pnictogen bonding involving bismuth, flexible accordion‐like molecular complexes of the composition [P(C6H4‐o‐CH2SCH3)3BiX3], (X=Cl, Br, I) have been synthesised and characterised. The strength of the weak and mainly electrostatic interaction between the Bi and P centres strongly depends on the character of the halogen substituent on bismuth, which is confirmed by single‐crystal X‐ray diffraction analyses, DFT and ab initio computations. Significantly, 209Bi–31P through‐space coupling (J=2560 Hz) is observed in solid‐state 31P NMR spectra, which is so far unprecedented in the literature, delivering direct information on the magnitude of this pnictogen interaction.
Fluoromethylene Transfer from Diarylfluoromethylsulfonium Salts: Synthesis of Fluorinated Epoxides
Authors: Veliks Janis , Kazia Armands 
Published: January 2019

AbstractDiarylfluoromethyl sulfonium salts are efficient fluoromethylene transfer reagents equivalent to fluorocarbene, which is difficult to access. This was demonstrated by the development of a monofluorinated Johnson–Corey–Chaykovsky reaction with ketones and aldehydes, delivering uncommon 2‐unsubstituted fluoroepoxides. This is the first evidence for the feasibility of sulfur fluoromethylylide and its action as a reaction intermediate.
Quantification of Entrainment Using an Optical Inline Probe
Authors: Lichti Markus , Schulz Jonas , Bart Hans‐Jörg 
Published: January 2019

AbstractIn distillation and absorption processes, entrainment above trays or packings reduces stage and column efficiency. A modified version of the optical multimode online probe enables a seminal insight and, thus, quantification of entrained droplets on various axial and radial positions. A purging mechanism inhibits precipitation of droplets on the front lenses, while telecentric optics and illumination provide distance‐independent and precise imaging of entrained droplets between two valve trays. Experiments were performed in a DN 450 cold flow (air‐water) test rig. The results were compared with noninvasive phase Doppler anemometry data.
A Novel Ratiometric Fluorescent Probe for Highly Sensitive and Selective Detection of β‐Galactosidase in Living Cells
Authors: Chen Min , Mu Lixuan , Cao Xingxing , She Guangwei , Shi Wensheng 
Published: January 2019

Summary of main observation and conclusionβ‐Galactosidase, a glycoside hydrolase enzyme, has been proved to be an important biomarker of cell senescence and primary ovarian cancer. Effective detection of β‐galactosidase has attracted wide attention. Herein, one ratiometric fluorescent probe has been successfully synthesized for detecting the β‐galactosidase in living cells. The as‐prepared probe exhibits two emission peaks at 490 nm and 530 nm, respectively, and the ratio of fluorescence intensities from the two emission peaks could be utilized to monitor the β‐galactosidase. This present ratiometric fluorescent probe is, therefore, very promising for effective, sensitive, and selective detection of the β‐galactosidase in living cells.
Training and accreditation standards for pathologists undertaking clinical trial work
Authors: Rees Gabrielle , Salto‐Tellez Manuel , Lee Jessica L , Oien Karin , Verrill Clare , Freeman Alex , Mirabile Ilaria , West Nicholas P ,   on behalf of the National Cancer Research Institute (NCRI) Cellular‐Molecular Pathology (CM‐Path) clinical trials working group
Published: January 2019

AbstractClinical trials rely on multidisciplinary teams for successful delivery. Pathologists should be involved in clinical trial design from the outset to ensure that protocols are optimised to deliver maximum data collection and translational research opportunities. Clinical trials must be performed according to the principles of Good Clinical Practice (GCP) and the trial sponsor has an obligation to ensure that all of the personnel involved in the trial have undergone training relevant to their role. Pathologists who are involved in the delivery of clinical trials are often required to undergo formal GCP training and may additionally undergo Good Clinical Laboratory Practice training if they are involved in the laboratory analysis of trials samples. Further training can be provided via trial‐specific investigator meetings, which may be either multidisciplinary or discipline‐specific events. Pathologists should also ensure that they undertake External Quality Assurance schemes relevant to the area of diagnostic practice required in the trial. The level of engagement of pathologists in academia and clinical trials research has declined in the United Kingdom over recent years. This paper recommends the optimal training and accreditation for pathologists undertaking clinical trials activities with the aim of facilitating increased engagement. Clinical trials training should ideally be provided to all pathologists through centrally organised educational events, with additional training provided to pathologists in training through local postgraduate teaching. Pathologists in training should also be strongly encouraged to undertake GCP training. It is hoped that these recommendations will increase the number of pathologists who take part in clinical trials research in order to ensure a high level and standard of data collection and to maximise the translational research opportunities.
Altered profile of circulating microparticles in nonvalvular atrial fibrillation
Authors: Siwaponanan Panjaree , Keawvichit Rassamon , Udompunturak Suthipol , Hunnangkul Saowalak , Reesukumal Kanit , Sukapirom Kasama , Pattanapanyasat Kovit , Krittayaphong Rungroj 
Published: January 2019

BackgroundNonvalvular atrial fibrillation (AF) is the most common cardiac arrhythmia, and it is associated with the prothrombotic state. Circulating microparticles (cMPs) are membrane vesicles that are shed from many cell types in response to cell activation and cell apoptosis. Several studies reported that cMPs may play a role in the hypercoagulable state that can be observed in patients with AF. The aim of this study was to determine the levels of total cMPs and characterize their cellular origins in AF patients.MethodsAtotal of 66 AF patients and 33 healthy controls were enrolled. This study investigated total cMP levels and their cellular origin in AF patients using polychromatic flow cytometry.ResultsAF patients had significantly higher levels of total cMPs (median 36.38, interquartile range [IQR] 21.16‐68.50 × 105 counts/mL vs median 15.21, IQR 9.91‐30.86 × 105 counts/mL; P = 0.004), platelet‐derived MPs (PMPs) (median 10.61, IQR 6.55‐18.04 × 105 counts/mL vs median 7.83, IQR 4.44‐10.26 × 10/mL; P = 0.009), and endothelial‐derived MPs (EMPs CD31+ CD41−) (median 2.94, IQR 1.78‐0.60 × 105 counts/mL vs median 1.16, IQR 0.71‐2.30 × 105 counts/mL; P = 0.001) than healthy controls after adjusting for potential confounders. Phosphatidylserine positive MP (PS + MP) levels were similar compared between AF patients and healthy controls.ConclusionThe results of this study revealed a marked increase in total cMP levels, and evidence of elevated endothelial damage and platelet activation, as demonstrated by increased PMP and EMP levels, in AF patients. Additional study is needed to further elucidate the role of cMPs (PMPs and EMPs) in the pathophysiology of and the complications associated with AF.
Prehensile kinematics of the marmoset monkey: Implications for the evolution of visually‐guided behaviors
Authors: Fox Dylan M. , Mundinano Inaki‐Carril , Bourne James A. 
Published: January 2019

AbstractThroughout the primate lineage, there is a wide diversity of prehensile capacity that is thought to stem from individual species foraging patterns. While many studies have explored primates with precise hand grips, such as higher apes, few have considered primates that lack opposition movements. The New World marmoset monkey occupies an intriguing niche, displaying adept control of their hand movements yet their absence of opposable digits results in relatively imprecise grasping actions when compared with those observed in Old World monkeys, apes, and humans. The marmoset monkey offers a unique composition of ancestral primate corticospinal organization combined with skilled hand use to explore the evolution and development of visually‐guided actions. In this study, four adult marmosets were trained to perform a series of visually‐guided tasks, designed to assess their control over locating and retrieving objects of differing dimensions. Two of these animals received a neonatal lesion of the inferior pulvinar (unilateral), a thalamic nucleus previously demonstrated to be involved in visuomotor development. The kinematics of their reaching and grasping patterns were recorded for offline analysis. Predictive modeling revealed that maximum grip aperture, time to reach peak velocity and hand use were reliable predictors of distinguishing between cohorts. A consistent feature observed across all tasks was that they do not precisely scale their grip according to the dimensions of the target object which may be attributed to their lack of independent digit control. Therefore, the marmoset monkey represents a previously understudied position in the evolution of primate reach and grasp behavior.
Subject‐specific loads on the lumbar spine in detailed finite element models scaled geometrically and kinematic‐driven by radiography images
Authors: Dehghan‐Hamani Iraj , Arjmand Navid , Shirazi‐Adl Aboulfazl 
Published: January 2019

AbstractTraditional load‐control musculoskeletal and finite element (FE) models of the spine fail to accurately predict in vivo intervertebral joint loads due mainly to the simplifications and assumptions when estimating redundant trunk muscle forces. An alternative powerful protocol that bypasses the calculation of muscle forces is to drive the detailed FE models by image‐based in vivo displacements. Development of subject‐specific models, however, both involves the risk of extensive radiation exposures while imaging in supine and upright postures and is time consuming in terms of the reconstruction of the vertebrae, discs, ligaments, and facets geometries. This study therefore aimed to introduce a remedy for the development of subject‐specific FE models by scaling the geometry of an existing detailed FE model of the T12‐S1 lumbar spine. Five subject‐specific scaled models were driven by their own radiography image‐based displacements in order to predict joint loads, ligament forces, facet joint forces, and disc fiber strains during relaxed upright as well as moderate flexion and extension tasks. The predicted intradiscal pressures were found in adequate agreement with in vivo data for upright, flexion, and extension tasks. There were however large intersubject variations in the estimated joint loads and facet forces.
Insight into the Mechanisms of Scale Inhibition: A Case Study of a Task‐Specific Fluorescent‐Tagged Scale Inhibitor Location on Gypsum Crystals
Authors: Oshchepkov Maxim , Kamagurov Semen , Tkachenko Sergei , Ryabova Anastasiya , Popov Konstantin 
Published: January 2019

AbstractScaling in reverse osmosis facilities, boilers, heat exchangers, evaporation plants, and oilfield applications is a serious problem worldwide. In order to provide a new insight into the mechanism of the scale formation and inhibition, a novel fluorescent‐tagged bisphosphonate scale inhibitor 1‐hydroxy‐7‐(6‐methoxy‐1,3‐dioxo‐1H‐benzo[de]isoquinolin‐2(3H)‐yl)heptane‐1,1‐diyl‐di(phosphonic acid), (HEDP−F) was synthesized and used for fluorescent microscope visualization of gypsum crystal formation in supersaturated aqueous solutions. The visualization of HEDP−F location on gypsum crystals has demonstrated that the bisphosphonate molecules do not act as they are expected to do according to the current scale inhibition theory. At ambient temperature the gypsum macrocrystals are found to form, and then to grow without visible sorption of bisphosphonate on the crystal edges or any other gypsum crystal growth centers. A tentative nonconventional mechanism of scale inhibition in the bulk supersaturated aqueous solutions of gypsum is proposed.