bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hetero‐Functional Polymers with Alternating Hydroxyl and Epoxy Groups Synthesized by Thiol‐yne Click (co)Polymerization
Authors: Zheng Yaochen , Zhang Qian , Gao Zhengguo , Li Fucun , Yan Bingfei , Li Wenzuo 
Published: September 2018

AbstractA new family of hetero‐functional polythioethers with alternating hydroxyl and epoxy groups are facilely synthesized via photo‐initiated thiol‐yne click (co)polymerization under mild reaction conditions. Their chemical structures and hetero‐functional group density can be finely tuned by adjusting the feeding mole ratios. As the evidence of nuclear magnetic resonance and gel permeation chromatography tests shows, either the molecular weight or the hetero‐functional group density depend greatly on the SH bond cleavage energy of dithiols which can be predicted by theoretical calculation, using the density functional theory (DFT) with B3LYP hybrid functional and the QCISD methods. This paper provides access to a wide range of new materials with a specific structure and plentiful alternating hetero‐functional groups. Moreover, it unveils and highlights the role of SH bond cleavage energy of dithiols during the process of step‐growth thiol‐yne click (co)polymerization.
Polysulfone‐Based Shape Memory Thermoplastics with Body Temperature Triggering
Authors: Aktas Eken Gozde , Acar Metin H. 
Published: September 2018

AbstractVarious polysulfone (PSf)‐based shape memory polymers (SMPs) with tunable transition temperature (T
trans) are prepared via atom transfer radical polymerization. Hard segments of SMPs are formed by PSf backbone which are then combined with nonlinear derivatives of poly(ethylene glycol) (PEG), that is, poly(ethylene glycol)methyl ether methacrylate as the soft segment. The melting temperature (T
m) of soft segments is shown to be an effective stimulus to achieve shape memory behavior. T
m values of graft copolymers are found in the range of body temperature from 32.7 to 39.1 °C, and SMPs are obtained with a maximum strain around 464%, tensile strength up to 6.8 MPa, and shape recovery ratio up to 99%. It is shown that the characteristic of SMPs can be tuned by altering the topology and the ratio of soft/hard segments. PSf‐based SMPs can be suitable for various applications since the material’s properties can be tailored for specific applications.
Green Electrospun Nanofibers and Their Application in Air Filtration
Authors: Lv Dan , Zhu Miaomiao , Jiang Zhicheng , Jiang Shaohua , Zhang Qilu , Xiong Ranhua , Huang Chaobo 
Published: September 2018

AbstractInterventions and policies for tackling air pollution issues exist and have been proven to be effective. Membrane materials of nanofibrous morphology are attractive for air filtration, and further alleviate the environmental issues. Electrospinning as a simple and versatile way to fabricate ultrafine fibers has been attracting tremendous attention. Herein, the recent researches and future trends of green electrospinning are expounded from the aspects of green degradable materials, green solution electrospinning, and solvent‐free electrospinning. The green degradable materials, including biomass materials, biosynthetic polymer materials, and chemical synthetic materials are reviewed. Following the concept of green electrospinning, electrospun polymer nanofibers via aqueous solution are discussed; additionally, further trends of solvent‐free electrospinning including melt‐electrospinning, anion‐curing electrospinning, UV‐curing electrospinning, thermo‐curing electrospinning, and supercritical CO2‐assisted electrospinning are highlighted. Furthermore, the applications of these electrospun nanofibrous membranes in the field of air filtration are discussed. In the end, the challenges of green electrospinning and future prospects are summarized. The development of green electrospinning is reviewed with an emphasis on current advanced solvent‐free research, where electrospun nanofibrous membranes are contributing to promising treatment strategies to solve environment issue.
Thermally Activated Delayed Fluorescent Polymers: Structures, Properties, and Applications in OLED Devices
Authors: Wei Qiang , Ge Ziyi , Voit Brigitte 
Published: September 2018

AbstractThermally activated delayed fluorescent (TADF) polymers are promising emitting materials to realize highly efficient, large‐scale, and low‐cost organic light‐emitting diodes (OLEDs) since they exhibit various advantages such as heavy‐metal‐free structures, 100% theoretical internal quantum efficiency, and ease of large‐area fabrication through solution process. At present, TADF polymers are still limited in category and complicated in preparation, which hinders their proceeding into industrial application. Besides, a still‐too‐low quantum efficiency poses a challenge for TADF‐polymer‐based OLEDs. In this review, different topologies and design strategies of the existing TADF polymers are covered, their structure–property relationships are illustrated, their first applications in OLED devices are discussed, and finally, an outlook of promising design rules for future TADF polymers is provided. The hope is to inspire researchers to develop TADF polymers prepared by easier synthesis strategies and higher external quantum efficiency to promote emitter application.
Use of existing electronic health care databases to evaluate medication safety in pregnancy: Triptan exposure in pregnancy as a case study
Authors: Yusuf Akeem , Chia Victoria , Xue Fei , Mikol Daniel D. , Bollinger Lisa , Cangialose Charles 
Published: September 2018

AbstractPurposeThe recent expansion of electronic health and medical record systems may present an opportunity to generate robust post‐approval safety data and obviate the limitations of prospective pregnancy exposure registries. We examined and compared, over the same time frame, the outcomes of triptan exposure in pregnancy using (1) a retrospective claims database and (2) a previously completed pregnancy registry.MethodsUsing the Marketscan database, the risk of major birth defects was ascertained in live‐born infants whose birth mothers were exposed to sumatriptan, naratriptan, or sumatriptan/naproxen during pregnancy. The frequencies of outcomes observed were compared with the findings of the 16‐year sumatriptan, naratripan, and sumatriptan/naproxen prospective pregnancy registry.ResultsAbout 5120 pregnancies were identified in the retrospective claims cohort in contrast to 617 included in the prospective registry during the same time frame. The proportion of major birth defects among first‐semester sumatriptan exposures was 4.0%, which is exactly the same as the proportion of major birth defects reported for first‐semester sumatriptan exposures in the registry. There were very few non‐livebirth outcomes in both the claims analyses and registry.ConclusionsThese results confirm broad agreement between the database analysis and the registry regarding the safety of triptans during pregnancy. Of note, the number of triptan‐exposed pregnancies identified in this large US database was about 7‐fold that included in the prospective registry over the same time frame. The findings of this study support an approach of using existing health care database (s) in the post‐approval assessment of medication exposure in pregnancy.
Emerging structural biology of lipid G protein‐coupled receptors
Authors: Audet Martin , Stevens Raymond C. 
Published: September 2018

ABSTRACTThe first crystal structure of a G protein‐coupled receptor (GPCR) was that of the bovine rhodopsin, solved in 2000, and is a light receptor within retina rode cells that enables vision by transducing a conformational signal from the light‐induced isomerization of retinal covalently bound to the receptor. More than 7 years after this initial discovery and following more than 20 years of technological developments in GPCR expression, stabilization, and crystallography, the high‐resolution structure of the adrenaline binding β2‐adrenergic receptor, a ligand diffusible receptor, was discovered. Since then, high‐resolution structures of more than 53 unique GPCRs have been determined leading to a significant improvement in our understanding of the basic mechanisms of ligand‐binding and ligand‐mediated receptor activation that revolutionized the field of structural molecular pharmacology of GPCRs. Recently, several structures of eight unique lipid‐binding receptors, one of the most difficult GPCR families to study, have been reported. This review presents the outstanding structural and pharmacological features that have emerged from these new lipid receptor structures. The impact of these findings goes beyond mechanistic insights, providing evidence of the fundamental role of GPCRs in the physiological integration of the lipid signaling system, and highlighting the importance of sustained research into the structural biology of GPCRs for the development of new therapeutics targeting lipid receptors.
On the damage done to the structure of the Thermoplasma acidophilum proteasome by electron radiation
Authors: Wang Jimin , Liu Zheng , Crabtree Robert H. , Frank Joachim , Moore Peter B. 
Published: September 2018

AbstractIt has long been known that proteins are damaged when they are exposed to the electron beam in an electron microscope. Here we show that exposure to electrons under cryo‐EM conditions leads to a small change in the quaternary structure of the Thermoplasma acidophilum proteasome, and that backbones atoms belonging to the α‐helices in this molecule appear to be particular prone to chemical damage. A chemical mechanism is proposed for this damage. Both this local chemical effect and the more global quaternary structure effect appear to heterogenize samples leading to a radiation dose‐dependent degradation of the resolution of the EM maps obtained from this molecule.
Methods for the assessment of selection bias in drug safety during pregnancy studies using electronic medical data
Authors: Schnitzer Mireille E. , Blais Lucie 
Published: September 2018

AbstractElectronic health data are routinely used for population drug studies. Due to the ethical dilemma in carrying out experimental drug studies on pregnant women, the effects of medication usage during pregnancy on fetal and maternal outcomes are largely evaluated using this data collection medium. One major limitation in this type of study is the delayed inclusion of pregnancies in the cohort. For example, in the province of Quebec, Canada, a major pregnancy cohort only captured pregnancies after 20 weeks gestation. The purpose of this study was to demonstrate three methods that can be used to assess the extent of selection bias due to the delayed inclusion of pregnancies. We use causal directed acyclic graphs to explain the source of this selection bias. In an example involving a cohort of pregnant asthmatic women reconstructed from the linkage of administrative health databases from the province of Quebec, we use numerical derivations, a simulation study and a sensitivity analysis to investigate the potential for bias and loss of power due to the delayed inclusion. We find that this selection bias can be partially mitigated by controlling for variables related to (spontaneous or therapeutic) abortion and the outcome of interest. The three proposed methods allow for the pre and post hoc ascertainment of the bias. While delayed pregnancy inclusion selection bias (which includes “live birth bias”) can produce substantial bias in pregnancy drug studies, all three methods are effective at producing estimates of the size of the bias.
Cool storage of Queensland fruit fly eggs for increased flexibility in rearing programs
Authors: Benelli Maurizio , Ponton Fleur , Taylor Phillip W 
Published: September 2018

AbstractBACKGROUNDThe Queensland fruit fly (Q‐fly) is Australia's most economically damaging insect pest of fruit crops. The Sterile Insect Technique (SIT) used to suppress outbreaks relies on supply of high‐quality flies and this can be assisted by the ability to manipulate production schedules. Cool storage at temperatures that are sufficient to slow development without causing significant somatic damage can provide a valuable means of manipulating production schedules. In this study, we investigate the effect of four storage temperatures (10, 13, 16 and 19 °C) and three exposure times (3, 6 or 9 days) on Q‐fly eggs.RESULTSEgg storage proved effective in prolonging the developmental time of Q‐flies. Storage at 10 °C was unsuitable, resulting in a low hatching rate for all exposure times. Hatching rate was also significantly reduced when eggs were exposed to 13 °C for 6 or 9 days, followed by a significant reduction in the number of pupae recovered. Storage at 16 °C yielded promising results, prolonging the preimaginal development of Q‐flies up to 6.5 days without significantly affecting egg hatching or subsequent development.CONCLUSIONCool storage of eggs shows promise as a tool for prolonging the development of Q‐flies to manipulate schedules in mass rearing programs. © 2018 Society of Chemical Industry
Vibrational mating disruption of Empoasca vitis by natural or artificial disturbance noises
Authors: Nieri Rachele , Mazzoni Valerio 
Published: September 2018

AbstractBackgroundThe green leafhopper, Empoasca vitis, is a polyphagous pest of grapevine and tea plants. To date population density is controlled primarily by insecticides and there is a demand for more sustainable controls. To develop a vibrational mating disruption method, the natural occurrence of a ‘disruptive signal’ was investigated. Further, the efficacy of natural and artificial ‘disruptive signals’ was determined.ResultsWith behavioral trials we described male rivalry and recorded a species‐specific disruptive signal (DP). The DP, a single pulse overlapping the competitor male call, interfered with the rival's ability to locate the female. Laboratory playback disruption trials revealed that the pair formation process was prevented by artificial disturbance noises that included the following features: E. vitis DP, Scaphoideus titanus disturbance noise, and a pure tone (250 Hz). Among these, the pure tone was most efficient at preventing mating.ConclusionResults support development of a vibrational mating disruption method as a control strategy for E. vitis. To simultaneously disrupt the mating of E. vitis and S. titanus, the possibility of applying the S. titanus disturbance noise combined with the pure tone is discussed. © 2018 Society of Chemical Industry
New sampling strategies to reduce the effect of autocorrelation on the synthetic T2 chart to monitor bivariate process
Authors: Dargopatil Pramod , Ghute Vikas 
Published: September 2018

AbstractIn this paper, synthetic T2 chart is developed to monitor bivariate process with correlated variables and autocorrelated observations. The proposed chart is a combination of the Hotelling's T2 chart and the conforming run length chart. The operation and design of the chart are described when observations are autocorrelated and cross correlated. The first‐order vector autoregressive process VAR (1) is used to model the bivariate data from an autocorrelated process of interest. Using an average run length as performance measure criterion in the VAR (1) model, it is observed that autocorrelation seriously impact the performance of the synthetic T2 chart. To reduce the effect of autocorrelation on the performance of the synthetic T2 chart, the skip and mixed sampling strategies are implemented to form rational subgroups in the construction of synthetic T2 chart. The average run length performance of the synthetic T2 chart implementing these strategies is compared with that of the standard strategy of formation of rational subgroups. It is observed that implementing skip and mixed sampling strategies within rational subgroup improves the performance of the synthetic T2 chart.
An Aminosalicylic Acid‐Modified Cellulose Composite Used for Mercury (II) Removal from Single and Quarternary Aqueous Solutions
Authors: Li Ming , Li Bo , Pan Yuanfeng , Zhou Li , Xiao Huining 
Published: September 2018

AbstractA high efficient adsorbent based on cellulose with good reusability towards mercury (II) ions was successfully prepared via grafting copolymerization and coupling technology. Batch adsorption experiments were conducted to reveal adsorption behavior of the as‐prepared adsorbents. Effects of the initial concentration, pH of the solution, time of contact, temperature and coexisting ions of the system were investigated, respectively. Polymerization reaction via glycidyl methacrylate was carried out to greatly enhance the following graft efficiency with the polydentate ligand which could catch the heavy metal ions. The results indicated the adsorption capacity was as high as 657.9 mg/g for Hg (II). Meanwhile, Langmuir isotherm model was proved to be appropriate in describing the experimental data, and the adsorption process was found to fit well with the pseudo‐second‐order model. In addition, the adsorbent could be regenerated with high recovery efficiency after adsorption; and the equilibrium adsorption capacity for Hg (II) was maintained at 204.5 mg/g after 10 adsorption‐desorption cycles, which is of great importance for practical application.
4‐[(1, 3‐Dioxoisoindolin‐2‐yl)methyl]benzenesulfonamide: Full Structural and Spectroscopic Characterization and Molecular Docking with Carbonic Anhydrase II
Authors: Gökce Halil , Öztürk Nuri , Sert Yusuf , El‐Azab Adel S. , A. AlSaif Nawaf , Abdel‐Aziz Alaa A.‐M. 
Published: September 2018

AbstractThe structural, spectral, electronic, thermodynamic and nonlinear optical features of 4‐[(1, 3‐dioxoisoindolin‐2‐yl)methyl]benzenesulfonamide were investigated using experimental and theoretical methods. Experimental characterization was carried out via FT‐IR, Raman, carbon‐13 and proton NMR chemical shifts and UV‐Vis. spectroscopic techniques. The molecular electronic structure computations were done with DFT/B3LYP method using the 6–311++G(2d,2p) basis set. VEDA4 software was used to analyze in PED (potential energy distribution) to vibrational profile of computed harmonic frequencies. Hirshfeld surface analysis was performed to determine interactions in crystal packing of the compound. Additionally, the highest occupied molecular orbitals (HOMOs), lowest unoccupied molecular orbitals (LUMOs), nonlinear optical (NLO) analysis, molecular electrostatic potential (MEP and ESP) surfaces and thermochemical properties were studied with theoretical computational method. The localization contributions on the defined molecular groups of molecular orbitals in the electronic transitions were investigated. Enzyme‐ligand interactions of 4‐[(1, 3‐dioxoisoindolin‐2‐yl)methyl]benzenesulfonamide with carbonic anhydrase II were investigated by molecular docking analysis. The experimental and calculated structural and spectroscopic data were compared with each other. The correlation between computed results and experimental records is in a good harmony.
The best of both worlds: Can founder‐CEOs overcome the rich versus king dilemma after IPO?
Authors: Fattoum‐Guedri Asma , Delmar Frédéric , Wright Mike 
Published: September 2018

Research Summary: To prevent loss of control post‐IPO, founder‐CEOs can implement control‐enhancing mechanisms disconnecting ownership from voting rights. However, this decision places them in a rich versus king dilemma. If they choose to implement such mechanisms and secure the king position, they risk losing money at IPO. If they choose not to implement control‐enhancing mechanisms and adopt the rich position they risk losing control over the firm. We investigate theoretically and empirically the outcomes of this dilemma in a multi‐period setting (at IPO and post‐IPO). We found that the majority of founder‐CEOs who choose the king option recover initial wealth loss, and hence, they can reconcile the rich and king paths in the long‐run post‐IPO.
Managerial Summary: Founder‐CEOs often use control‐enhancing mechanisms (CEMs), such dual class shares, pyramid control structures, and pact agreements, to maintain control over their IPO firms. In this study, we investigate the effects of these CEMs on firm value at IPO and post‐IPO using a unique hand‐collected dataset comprising all founder‐CEO led firms that went public on French regulated markets between January 1992 and December 2010. We found that most founder‐CEOs who use multiple CEMs leave considerable amounts of money on the table at IPO date but they are able to recover their initial loss 5 years post‐IPO. This result suggests that an IPO may constitute a valuable financing alternative even for founder‐CEOs who value control.
Size, Shape, and Protein Corona Determine Cellular Uptake and Removal Mechanisms of Gold Nanoparticles
Authors: Ding Lin , Yao Chenjie , Yin Xiaofeng , Li Chenchen , Huang Yanan , Wu Min , Wang Bin , Guo Xiaoya , Wang Yanli , Wu Minghong 
Published: September 2018

AbstractSize, shape, and protein corona play a key role in cellular uptake and removal mechanisms of gold nanoparticles (Au NPs). The 15 nm nanoparticles (NP1), the 45 nm nanoparticles (NP2), and the rod‐shaped nanoparticles (NR) enter into cells via a receptor‐mediated endocytosis (RME) pathway. The star‐shaped nanoparticles (NS) adopt not only clathrin‐mediated, but also caveolin‐mediated endocytosis pathways. However, the 80 nm nanoparitcles (NP3) mainly enter into the cells by macropinocytosis pathway due to the big size. Furthermore, the results indicate that the presence of protein corona can change the uptake mechanisms of Au NPs. The endocytosis pathway of NP1, NP2, and NS changes from RME to macropinocytosis pathway and NR changes from RME to clathrin and caveolin‐independent pathway under the non‐fetal bovine serun (FBS)‐coated condition. Both FBS‐coated and non‐FBS‐coated of five types of Au NPs are released out through the lysosomal exocytosis pathway. The size, shape, and protein corona have an effect on the exocytosis ratio and amount, but do not change the exocytosis mechanism. The systematic study of the endocytosis and exocytosis mechanism of Au NPs with different sizes and shapes will benefit the toxicology evaluation and nanomedicine application of Au NPs.
Electrochemical Deposition Tailors the Catalytic Performance of MnO2‐Based Micromotors
Authors: Liu Wenjuan , Ge Hongbin , Gu Zhongwei , Lu Xiaolong , Li Jinxing , Wang Joseph 
Published: September 2018

AbstractArtificial micro/nanomotors that could perform diverse tasks autonomously at the micro/nanoscale have been emerging as promising tools in many practical applications. Electrochemical synthesis is one of the dominating methods to fabricate these micro/nanodevices with diverse geometries and material components. By changing the conditions of electrochemical deposition, the surface morphology, crystal structure, and hence the resultant performance of deposited material could be tailored. In the current work, a feasible fabrication strategy is presented in terms of three unique electrodeposition types (i.e., potentiodynamic, potentiostatic (PS), and galvanostatic) to synthesize different MnO2‐based micromotors. Distinct propulsion behavior as well as the catalytic degradation of azo‐dye organic waste (with methylene blue as the representative), between three kinds of MnO2‐based micromotors is clearly displayed, owing to the distinctive chemical composition and morphology designs. The activated R‐MnO2‐based micromotors in PS mode exhibit fast motion speed (up to 12 body length per second), leading to the highest degradation efficiency. Such propulsion performance is comparable with the microrockets made by noble metals such as Pt and Ag. The new protocol will have a profound impact on the design of synthetic micro/nanomotors and hold a considerable promise for their diverse applications.