bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controlled random copolymerization of rac‐lactide and ɛ‐caprolactone by well‐designed phenoxyimine Al complexes
Authors: Shi Tong , Luo Wenlong , Liu Shaofeng , Li Zhibo 
Published: December 2017

ABSTRACTThe random copolymers poly(LA‐ran‐CL) have improved properties of degradability, mechanical strength, elasticity, and permeability over the PLA and PCL homopolymers. However, the synthesis of such copolymers is still a great challenge in polymer chemistry. In this contribution, we develop a simple but well‐designed phenoxyimine Al complex (4) with bulky Ph2CH groups, which achieves controlled random copolymerization of rac‐LA and ɛ‐CL in a living manner (Ð = 1.06–1.09). The reactivity ratios of rac‐LA and ɛ‐CL (rLA and rCL) are 1.09 and 1.05 and the average sequence lengths of the lactidyl unit (LLA) and the caproyl unit (LCL) are in the range of 1.9–2.0 at different stages of conversion. In marked contrast, Al complexes (1–3) having less bulky substituents on the ligands only produce gradient copolymers. Furthermore, this strategy of catalyst design would be readily extended to other catalytic systems including β‐ketiminato Al complex (5). © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 611–617
Conflicting evidence for the role of JNK as a target in breast cancer cell proliferation: Comparisons between pharmacological inhibition and selective shRNA knockdown approaches
Authors: Wood Rachel A. , Barbour Mark J. , Gould Gwyn W. , Cunningham Margaret R. , Plevin Robin J. 
Published: December 2017

AbstractAs a target, the JNK pathway has been implicated in roles including cell death, proliferation, and inflammation in variety of contexts which span cardiovascular disease, neurodegenerative pathologies, and cancer. JNK1 and JNK2 have recently been demonstrated to function independently, highlighting a new parameter in the study of the JNK pathway. In order for JNK1 and JNK2‐specific roles to be defined, better tools need to be employed. Previous studies have relied upon the broad spectrum JNK inhibitor, SP600125, to characterize the role of JNK signaling in a number of cell lines, including the breast cancer cell line MCF‐7. In line with previous literature, our study has demonstrated that SP600125 treatment inhibited c‐Jun and JNK phosphorylation and MCF‐7 proliferation. However, in addition to targeting JNK1, JNK2, and JNK3, SP600125 has been previously demonstrated to suppress the activity of a number of other serine/threonine kinases, making SP600125 an inadequate tool for JNK isoform‐specific roles to be determined. In this study, lentiviral shRNA was employed to selectively knockdown JNK1, JNK2, and JNK1/2 in MCF‐7 cells. Using this approach, JNK phosphorylation was fully inhibited following stable knockdown of respective JNK isoforms. Interestingly, despite suppression of JNK phosphorylation, MCF‐7 cell proliferation, cell cycle progression, or cell death remained unaffected. These findings raise the question of whether JNK phosphorylation really is pivotal in MCF‐7 cell growth and death or if suppression of these events is a result of one of the many off‐targets cited for SP600125.
A simple and reliable method reducing sulfate to sulfide for multiple sulfur isotope analysis
Authors: Geng Lei , Savarino Joel , Savarino Clara A. , Caillon Nicolas , Cartigny Pierre , Hattori Shohei , Ishino Sakiko , Yoshida Naohiro 
Published: December 2017

RationalePrecise analysis of four sulfur isotopes of sulfate in geological and environmental samples provides the means to extract unique information in wide geological contexts. Reduction of sulfate to sulfide is the first step to access such information. The conventional reduction method suffers from a cumbersome distillation system, long reaction time and large volume of the reducing solution. We present a new and simple method enabling the process of multiple samples at one time with a much reduced volume of reducing solution.MethodsOne mL of reducing solution made of HI and NaH2PO2 was added to a septum glass tube with dry sulfate. The tube was heated at 124°C and the produced H2S was purged with inert gas (He or N2) through gas‐washing tubes and then collected by NaOH solution. The collected H2S was converted into Ag2S by adding AgNO3 solution and the co‐precipitated Ag2O was removed by adding a few drops of concentrated HNO3.ResultsWithin 2–3 h, a 100% yield was observed for samples with 0.2–2.5 μmol Na2SO4. The reduction rate was much slower for BaSO4 and a complete reduction was not observed. International sulfur reference materials, NBS‐127, SO‐5 and SO‐6, were processed with this method, and the measured against accepted δ34S values yielded a linear regression line which had a slope of 0.99 ± 0.01 and a R2 value of 0.998.ConclusionsThe new methodology is easy to handle and allows us to process multiple samples at a time. It has also demonstrated good reproducibility in terms of H2S yield and for further isotope analysis. It is thus a good alternative to the conventional manual method, especially when processing samples with limited amount of sulfate available.
Prominin-1/CD133: Lipid Raft Association, Detergent Resistance, and Immunodetection
Authors: Karbanová Jana , Lorico Aurelio , Bornhäuser Martin , Corbeil Denis , Fargeas Christine A. 
Published: December 2017

Summary
The cell surface antigen prominin-1 (alias CD133) has gained enormous interest in the past 2 decades and given rise to debates as to its utility as a biological stem and cancer stem cell marker. Important and yet often overlooked knowledge that is pertinent to its physiological function has been generated in other systems given its more general expression beyond primitive cells. This article briefly discusses the importance of particular biochemical features of CD133 with relation to its association with membrane microdomains (lipid rafts) and proper immunodetection. It also draws attention toward the adequate use of detergents and caveats that may apply to the interpretation of the results generated.
Controlled‐Release‐Based Ultrasensitive and Highly Selective Turn‐On Fluorescent Mercury Biosensor
Authors: Wang Wei , Li Xin , Hou Xiaoshan , Wang Shiying , Wang Fengying , Luo Xiliang 
Published: December 2017

AbstractA novel fluorescent biosensor for ultrasensitive and highly selective detection of Hg2+ was developed by coupling Hg2+‐induced conformational change of single‐stranded DNA recognition probe with T‐rich sequence and controlled‐release of cargo molecules loaded by Au nanocages with T–Hg2+–T coordination chemistry. A detection limit of as low as 1.4×10−12 M with an excellent selectivity toward Hg2+ could be achieved. The developed amplification strategy based on the controlled‐release of fluorescent molecules reached an extraordinary sensitivity of analyses, and may be further extended for the detection of a large class of analytes including protein, DNA and biological small molecules by combining molecular gate technology. The results of fluorescence microscopy imaging in living cells indicate that the fabricated system is an efficient controlled‐release biosensor in response to intracellular target molecules and predict its potential use for in situ molecular imaging in living systems.
Phase Equilibria and Condensed Phase Properties of Fluorinated Alkanes via First Principles Simulations
Authors: Goel Himanshu , Windom Zachary W. , Butler Charles L. , Rai Neeraj 
Published: December 2017

AbstractVapor liquid equilibria (VLE) of organic compounds is governed by weak non‐covalent interactions. This presents a significant challenge in predicting VLE using a first principles approach where density functional theory is used to model system potential. However, a dispersion corrected approach has significantly improved the performance of traditional density functionals. Here, we predict the VLE for a nonpolar carbon tetrafluoride (R14) and polar 1,1,1,2‐tetrafluoroethane (R134a) via first principles Gibbs ensemble Monte Carlo simulations using PBE−D3 density functional. We find that the saturated liquid density for R14 is slightly under predicted for subcritical temperatures, while for R134a it is under predicted at lower reduced temperatures and over predicted at higher reduced temperatures. In the liquid phase, angle‐resolved pair correlation functions indicate slight preference for R143a to align in parallel and antiparallel orientation in the first solvation shell. The vibrational spectra reveal peak broadening in the condensed phase due to solvothermal effects. Overall, we find the PBE−D3 functional performance is better for the nonpolar molecule as compared to the polar one.
High Resolution Crystal Structures of the Acetohydroxyacid Synthase‐Pyruvate Complex Provide New Insights into Its Catalytic Mechanism
Authors: Lonhienne Thierry , Garcia Mario D. , Noble Chris , Harmer Jeffrey , Fraser James A. , Williams Craig M. , Guddat Luke W. 
Published: December 2017

AbstractAcetohydroxyacid synthase (AHAS) is the first enzyme in the biosynthesis pathway of the branched‐chain amino acids, catalyzing the condensation of pyruvate with another molecule of pyruvate or with 2‐ketobutyrate, to produce 2‐acetolactate or 2‐acetohydroxybutyrate, respectively. The catalytic subunit of the dimeric enzyme has thiamin diphosphate (ThDP), a divalent metal ion, flavin adenine dinucleotide (FAD), and two molecules of oxygen (O2(I) and O2(II)) as cofactors. Here, crystal structures of Saccharomyces cerevisiae AHAS in complex with pyruvate provide novel insights into the mechanistic features of this enzyme including: i) The precise position taken by pyruvate molecules as they enter the active site (i. e. prior to catalysis occurring) with conformations suitable for the transfer of electrons to/from O2(I) and FAD; ii) The formation of ternary donor‐acceptor‐O2(I) complexes and iii) The location of O2(II) relative to the substrate showing that it plays a critical role in the organization of substrate for catalysis. These structural data, accompanied by electron paramagnetic resonance evidence that a radical is produced during AHAS catalysis, lead to the proposal that FAD and O2 are involved in an indirect one‐electron redox cycle. In this mechanism, the spatial configurations of O2 and FAD in the active site can allow electrons to be exchanged with the substrates and catalytic intermediates to satisfy and control the overall AHAS catalyzed reaction.
Synthesis of Constrained Heterocycles Employing Two Post‐Ugi Cyclization Methods for Rapid Library Generation with In Cellulo Activity
Authors: McConnell Nicholas , Xu Zhigang , Kumarasamy Vishnu , Sun Daekyu , Frett Brendan , Li Hong‐yu 
Published: December 2017

AbstractBenzimidazoles and quinoxalinones are present in the core of many pharmacologically relevant compounds. Several combinatorial methods have been developed to attach ring systems to both scaffolds for derivatization at select positions. Herein, we describe the development of novel constrained heterocyclic compounds attached to the N1 position of both benzimidazole and quinoxalinone scaffolds. Utilizing robust post‐Ugi cyclization methods, including the Ugi‐deprotection‐cyclization (UDC) methodology, allows for efficient access to a new area of chemical space. Additionally, molecular modeling and in cellulo screening was employed to therapeutically validate the compounds formed with this method.
Alkali Cation Effect During the Oscillatory Electroreduction of H2O2 on Pt
Authors: da Silva Kaline N. , Nagao Raphael , Sitta Elton 
Published: December 2017

AbstractHydrogen Peroxide Reduction Reaction (HPRR) catalyzed by Pt was studied in alkaline media and the effect of alkali cations were analyzed by the changes on dynamic instabilities presented by this system under high ohmic drop conditions. The origin of these instabilities is the competition between OH2− electroreduction and hydrogen adsorption on Pt surfaces, the latter being the first step for hydrogen evolution reaction (HER). Both HER and hydrogen adsorption are cation‐dependent which suggests that noncovalent interactions are able to stabilize the water molecules favoring the Pt−H formation. Thus, in an interphase, in which the noncovalent interactions are more effective, HPRR will proceed as an indirect poisoned system, reflecting on slow frequency oscillations (ω), for instance ωLiOH < ωNaOH < ωKOH for several H2O2 concentrations.
Allylic Selenocyanates as New Agents to Combat Fusarium Species Involved with Human Infections
Authors: Batista Bruna G. , Lana Daiane F. Dalla , Silveira Gustavo P. , Sá Marcus M. , Ferreira Misael , Russo Theo V. C. , Canto Rômulo F. S. , Barbosa Flavio A. R. , Braga Antônio L. , Kaminski Taís F. A. , de Oliveira Luís F. S. , Machado Michel M. , Lopes William , Vainstein Marilene H. , Teixeira Mário L. , Andrade Saulo F. , Fuentefria Alexandre M. 
Published: December 2017

AbstractFusarium is an emerging opportunistic fungal pathogen that causes local or systemic infections. The successful use of a therapeutic drug or combination antifungal therapies against Fusarium spp. are compromised because reports of multidrug resistance are currently frequent. Thus, the development of new antifungal capable of combating multidrug‐resistant Fusarium strains becomes necessary. This study presents the synthesis of seven new allylic selenocyanates and their screening against Fusarium spp. Minimum inhibitory concentrations (MICs) of these compounds ranged from 4 to 64 μg mL−1, with the mechanism of action being related to fungal cell membrane disruption. Specific structural changes, such as widespread thinning along the hyphae, were observed by scanning electron microscopy. The effect of selenocyanates on cell viability and genotoxicity are concentration dependent, however they did not cause mutagenicity in human cells. Five selenocyanates were identified as nonirritant by the ex‐vivo HET‐CAM (Hen′s Egg Test‐Chorioallantoic Membrane) method. Allylic selenocyanates represents a promising alternative in the treatment and prevention of fusariosis.
Three‐Component Synthesis of 3,4‐Disubstituted Pyrazoles Using Diazosulfone as a Diazomethane Surrogate
Authors: Ahamad Shakir , Patidar Rajesh Kumar , Kumar Anuj , Kant Ruchir , Mohanan Kishor 
Published: December 2017

AbstractA three‐component synthesis of 3‐acyl‐4‐(het)arylpyrazoles employing aldehydes, Horner‐Wadsworth‐Emmons reagents, and α‐diazo‐β‐ketosulfone has been achieved. The reaction involves a domino HWE reaction/1,3‐dipolar cycloaddition/desulfonylation process and generates the pyrazole derivatives in excellent yields. This three‐component strategy provides a versatile platform to synthesize a range of 3,4‐disubstituted pyrazoles employing diazoketosulfone as a diazomethane surrogate. The reaction exhibits high functional group tolerance and works under ambient conditions.
Syntheses and Structural Characterization of A3Sb3P2O14⋅3H2O (A=Rb, Cs, Tl and NH4) Phosphates; Facile Aqueous Ion Exchange Reactions of K3Sb3P2O14⋅3H2O
Authors: Walko Priyanka S. , Paidi Anil Kumar , Vidyasagar Kanamaluru 
Published: December 2017

AbstractFour quaternary phosphates of antimony, A3Sb3P2O14⋅3H2O (A=Rb, Cs, Tl and NH4) have been prepared by solid state and hydrothermal reactions and structurally characterized by single crystal and powder X‐ray diffraction techniques. They are isostructural with reported K3Sb3P2O14⋅3H2O compound and all five of them have layered structure, wherein the hexagonal‐tungsten‐oxide (HTO) related (Sb3P2O14)3− anionic layers are interleaved with the A+ ions and water of crystallization. K3Sb3P2O14⋅3H2O undergoes topotactic ion‐exchange reactions with aqueous solutions of ACl (A=Rb, Cs, Tl, NH4) salts, almost quantitatively.
Liquid‐Crystalline Phthalocyanine Derivatives Bearing Oligosiloxane Moieties: Soft Columnar Mesophases Stabilized by Nanosegregation
Authors: Yamaoka Ryutaro , Funahashi Masahiro 
Published: December 2017

AbstractNovel liquid‐crystalline (LC) nickel phthalocyanine (Ni−Pc) complexes bearing eight oligosiloxane moieties such as disiloxane and trisiloxane were synthesized and their liquid‐crystalline properties, as well as their carrier transport characteristics in the liquid‐crystalline phase, were studied. These LC Ni−Pc complexes with eight oligosiloxane moieties exhibited a columnar mesophase over a wide range of temperatures, including room temperature. The bulky oligosiloxane moieties inhibited the aggregation of the Ni−Pc cores and stabilized the columnar structure by nanosegregation. Moreover, these LC Pc−Ni complexes showed homeotropic alignment in sandwich‐type cells consisting of substrates coated with indium tin oxide. Time‐of‐flight measurements revealed ambipolar carrier transport properties in the columnar mesophases, in which electron transport was predominant.
Nanostructure PEO‐Silica Hybrids: A New Class of Additive Material for Composite Polymer Electrolytes
Authors: Mohanta Jagdeep , Panda Subhendu K , Singh Udai P. , Si Satyabrata 
Published: December 2017

AbstractHybrid nanostructure polyethylene oxide (PEO)‐silica hybrids (PSH) prepared by sol‐gel chemistry are utilized as novel nanofiller to fabricate PEO‐based nanocomposite polymer elecytrolytes (NCPEs) by adopting the conventional solvent casting approach. The resulting PSH hybrids are characterized by various techniques followed by their incorporation into NCPEs that result in enhancement in the Li‐ion conductivity and a maximum ionic conductivity of 7.20 × 10−5 S cm−1 is achieved with only 0.25% nanofillers. The temperature dependence conductivity study shows a linear behavior below melting temperature following the Arrhenius equation and shows non‐linear behavior above the melting temperature following the Vogel–Taumann–Fulcher (VTF) equation. Argand plots of various NCPEs both at room temperature and elevated temperature signify the role of various relaxation processes for such type of conducting behavior, which is further supported by dielectric and tangential loss studies. Moreover, X‐ray diffraction and Differential Scanning Calorimetry measurements are carried out to understand the change in polymer crystallinity in the resulting NCPEs and are well in accordance with the conductivity changes.
Solubilization of Hydrophobic Catalysts Using Nanoparticle Hosts
Authors: Jeong Youngdo , Tonga Gulen Yesilbag , Duncan Bradley , Yan Bo , Das Riddha , Sahub Chonticha , Rotello Vincent M. 
Published: December 2017

AbstractA modular strategy for the solubilization and protection of hydrophobic transition metal catalysts using the hydrophobic pockets of water soluble gold nanoparticles is reported. Besides preserving original catalyst activity, this encapsulation strategy provides a protective environment for the hydrophobic catalyst and brings reusability. This system provides a versatile platform for the encapsulation of different hydrophobic transition metal catalysts, allowing a wide range of catalysis in water while uniting the advantages of homogeneous and heterogeneous catalysis in the same system.
Academic and Career Development: Rethinking Advising for Asian American Students
Authors: Kodama Corinne M. , Huynh Jill 
Published: December 2017

AbstractAcademic and career development for Asian American students is complicated by cultural influences, interdependence with family, and racial stereotyping. This chapter highlights research, theory, and practice to help educators rethink traditional advising approaches to more appropriately work with Asian American students as they navigate their academics and careers.
Complicated grief and caregiving correlates among bereaved adolescent girls in South Africa
Authors: Thurman Tonya R. , Taylor Tory M. , Luckett Brian , Spyrelis Alexandra , Nice Johanna 
Published: December 2017

ABSTRACTTo our knowledge, this is the first study to document correlates of complicated grief among bereaved adolescents in sub‐Saharan Africa. Participants included 339 female adolescents in South Africa who experienced the loss of a loved one at least six months prior to the survey; their primary caregivers were also surveyed. One‐fifth of adolescents were classified as having complicated grief using the Inventory of Complicated Grief Revised for Children in conjunction with grief‐induced functional impairment. The loss of a biological parent, the primary caregiver's level of grief, and economic stressors since the loss were associated with increased odds of complicated grief among adolescents. Adolescents' age, residential changes, time since the loss, multiple losses, bereavement due to death by illness, and caregiver depression did not affect the odds. Findings signal the potential of family‐centered interventions and economic support services for bereaved adolescents.
Design and analysis of a novel wireless resistive analog passive sensor technique
Authors: Consul‐Pacareu Sergi , Morshed Bashir I. 
Published: December 2017

Unobtrusive monitoring of physiological signals in natural settings is important for precision diagnostics. Fully‐passive wireless body‐worn sensors are viable and promising for unobtrusive monitoring. In this study, the authors present a new class of fully‐passive sensor, namely wireless resistive analog passive (WRAP) sensor. It uses resistive transducers at the sensors for converting physical stimulus to load modulation of carrier wireless signal at 13.56 MHz at low power (–20 to 0 dBm). The sensor is simply composed of a loop antenna, a tuning capacitor, and a resistive transducer suitable for the type of physiological signals to be measured. The authors report the characterisation of WRAP sensors for various resistive loads of 1.2 ω to 82 kω at various co‐axial distances (5–40 mm) between the TX and RX antennas. They have prototyped and characterised multiple WRAP sensors with several practical measurements of physiological signals such as heart rate, temperature, and pulse oximetry. They also demonstrate bio‐potential measurement (down to 400 μVpp) using metal–oxide–semiconductor field‐effect transistor as the transducer. These results show the feasibility of developing a new type of body‐worn fully‐passive WRAP sensors for unobtrusive physiological signal monitoring at real‐life settings for precision diagnostics of many disorders and tracking person‐centric therapy efficacy.