bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorescent, electroactive, thermally stable triphenylamine‐ and naphthalene‐based polyimides for optoelectronic applications
Authors: Khalid Naila , Park O. OK , Akhter Toheed , Siddiqi Humaira M. 
Published: October 2016

ABSTRACTTo tune the photophysical properties of polyimides (PIs), a diamine containing naphthalene and triphenylamine units, N1‐(4‐aminophenyl)‐N1‐[(4‐naphthalene‐2‐yloxy)phenyl]benzene‐1,4‐diamine (DA), was synthesized. A series of fluorescent electroactive new PIs from synthesized DA were prepared with conventional thermal imidization with dianhydride. The selected dianhydride were used to study and compare the effects of rigid planar phenyl, flexible phenoxy, and nonplanar flexible hexafluoroisopropyidene and carbonyl groups in the main polymer backbone on the optoelectronic properties and processability of materials. The structures of the synthesized diamine and its PIs were evaluated by spectral and CHNS elemental analysis. The optoelectronic and thermal properties of PIs revealed intense blue‐light emission (428–477 nm), a low oxidation potential (0.3–1.3 V), and a lower highest occupied molecular orbital–lowest unoccupied molecular orbital gap (2.92–3.21 eV). The observed behavior and properties of our synthesized PIs suggest their potential as future hole‐transport materials in optoelectronic applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44526.
Small‐molecule‐induced miscibility of isosorbide‐based polycarbonate with bisphenol A polycarbonate
Authors: Su Lili , Lai Wenqin , Yan Jin , Wu Guozhang 
Published: October 2016

ABSTRACTIn this study, we investigated the influence of the small molecule 4,4′‐thiobis(6‐tert‐butyl‐m‐methyl phenol) (AO300) on the miscibility of poly(isosorbide‐co‐1,4‐cyclohexanedimethanol carbonate) (IcC–PC) with bisphenol A polycarbonate (BPA–PC) through the formation of hydrogen‐bonding networks. Differential scanning calorimetry and morphological observation revealed that the initially, immiscible BPA–PC/IcC–PC blends become miscible through the addition of small molecules. Fourier transform infrared spectroscopy confirmed that intermolecular hydrogen bonds formed between the hydroxyl groups of AO300 and the carbonyl groups of the studied polycarbonates. These polycarbonates exhibited different hydrogen‐bonding behaviors and various degrees of glass‐transition temperature composition dependence. Dynamic mechanical analysis demonstrated that AO300 played an antiplasticization role in the BPA–PC/IcC–PC blends with improved storage moduli. To our knowledge, this article is the first to describe the miscibility of isosorbide‐based polycarbonate with BPA–PC. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2017,134, 44537.
Composite effect of silica nanoparticle on the mechanical properties of cellulose‐based hydrogels derived from cottonseed hulls
Authors: Boonmahitthisud Anyaporn , Nakajima Lisa , Nguyen Khoa Dang , Kobayashi Takaomi 
Published: October 2016

ABSTRACTRecently, cellulose‐based hydrogel nanocomposite materials have been attracted increasing attention owing to their potential applications in different areas including medical, electrical, optical, and magnetic fields. This is due to the fact that cellulose is one of the most abundant resources and possesses several unique properties required in medical fields, whereas silica nanoparticles (nSiO2) play an important role in developing materials with high functionality. In this study, cottonseed hull (CSH) was used as a source of cellulose and nSiO2 was used to prepare hydrogel nanocomposite films via phase inversion method without chemical crosslinking agent of cellulose. CSH was first pre‐treated with sodium hydroxide (NaOH) and sodium hypochlorite (NaOCl) for delignification and bleaching, respectively. The pre‐treated CSH exhibited whiter fiber and lower amount of lignin as compared with the untreated CSH. The properties of cellulose‐base hydrogel were found to be improved as a result of the addition of nSiO2 at 2–6 wt % for tensile strength and up to 10 wt % for modulus and elastic modulus (G′). However, the elongation at break was decreased with the incorporation of nSiO2. Moreover, the TEM images displayed the nano‐grape structure of nSiO2 surrounded by cellulose molecules. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44557.
Spermatogonia, Germline Cells, and Testicular Organization in the Characiform Prochilodus lineatus Studied Using Histological, Stereological, and Morphometric Approaches
Authors: De Melo Dias Gisele Cristiane , Cassel Mônica , Oliveira De Jesus Lázaro Wender , Batlouni Sergio Ricardo , Borella Maria Inés 
Published: October 2016

ABSTRACTProchilodus lineatus is an important representative of the order Characiformes and a species that offers great advantages to fish farming. Therefore, detailed knowledge of its reproductive biology can be applied to various fields of production and biotechnology. In this study, we have identified testicular germ cells during spermatogenesis and have evaluated the volumetric proportion of the testes occupied by structures of the tubular and intertubular compartments. In addition, the individual volume of type A spermatogonia was measured and used to estimate the mean number of these cells per testis. Gonads of adult P. lineatus males were extracted and fixed. Light and transmission electron microscopy were applied to fragments of three testicular regions. Histological, stereological, and morphometric analyses were performed. The stereological data suggest that components of the tubular and intertubular compartments of the P. lineatus testes present a uniform distribution in all three regions and therefore reflect regions with similar distributions of cell types. In addition, P. lineatus testes showed ∼0.6% of type A spermatogonia, as well as a predominance of cysts of primary spermatocytes and spermatids during the reproductive phase evaluated. The results from this study provide a better understanding of the morphology and structure of the testis and of the characterization of the type A spermatogonia in P. lineatus. The nuclear diameter of germ cells also decreases significantly during spermatogenesis. The data presented herein are the first of its kind for the order Characiformes and may be useful for future biotechnology studies on fish reproduction. Anat Rec, 300:589–599, 2017. © 2016 Wiley Periodicals, Inc.
Pharmacokinetics of mangiferin and its metabolite—norathyriol, Part 2: Influence of UGT, CYP450, P‐gp, and enterobacteria and the potential interaction in Rhizoma Anemarrhenae decoction with timosaponin B2 as the major contributor
Authors: Tian Xiaoting , Xu Zhou , Li Zhixiong , Ma Yuanjie , Lian Shan , Guo Xiaozhen , Hu Pei , Gao Yu , Huang Chenggang 
Published: October 2016

AbstractThe poor bioavailability of mangiferin (MGF) is a major obstacle on its further development. Aimed to illustrate the underlying mechanism and improve its poor exposure, the compared PK profiles of MGF and norathyriol (NTR) after different MGF preparation were performed: pure MGF, the Rhizoma Anemarrhenae (Zhi‐mu) decoction, MGF, and timosaponin B2 (TB‐2) combination. Furthermore, the potential contributing factors, including uridine diphosphoglucuronosyltransferase (UGT), cytochrome P450 (CYP450), P‐gp, and enterobacterial were investigated by comparing the PK profiles with and without the corresponding inhibitors or in different rat models. After taking MGF, CYP450 and UGT inhibition could decrease MGF and NTR exposure; P‐gp inhibition slightly enhanced (48%) MGF exposure, whereas more apparent for the improved NTR exposure (302%); enterobacterial inhibition almost completely stopped the NTR production, but no such effect was observed for MGF. Compared with the limited improvement by the abovementioned inhibition, the MGF and NTR exposure could significantly increase by 11.5‐ and 5.9‐fold in the Zhi‐mu decoction compared with the MGF treatment, probably contributed to TB‐2 as an absorption enhancer because the MGF and TB‐2 combination produced a similar level of improvement on the PK paremeters of MGF and NTR to the herb treatment. Likewise, most of the effects by UGT, CYP450, P‐gp, and enterobacteria followed a similar variation tendency between them. Therefore, the poor bioavailability of MGF possibly mainly attributed to its poor membrane permeability, but not transporters or metabolic enzymes, and the compatibility of MGF and TB‐2 could probably expand the prospective application of MGF by improving its bioavailability. © 2016 BioFactors, 42(5):545–555, 2016
Pharmacokinetics of mangiferin and its metabolite—Norathyriol, Part 1: Systemic evaluation of hepatic first‐pass effect in vitro and in vivo
Authors: Tian Xiaoting , Gao Yu , Xu Zhou , Lian Shan , Ma Yuanjie , Guo Xiaozhen , Hu Pei , Li Zhixiong , Huang Chenggang 
Published: October 2016

AbstractMangiferin (MGF), a glucoside of xanthone existing in phytomedicines and food, is increasingly attracting attention on diabetes treatment, while the underlying mechanism leading to its low oral bioavailability is unclear. Norathyriol (NTR), an active metabolite with hypoglycemic activity and its exposure after MGF dosing remains unclear. Hence, a rapid and sensitive LC‐MS/MS method was established and validated to determine MGF and NTR and applied in the PK study in rats. Correspondingly, the in vitro experiments on temperature‐dependent uptake, and MGF metabolism in hepatocyte and enterobacteria samples were performed. Results revealed that hepatic first‐pass effect slightly contributed to the poor bioavailability of MGF, based on the MGF exposure in portal vein plasma was nearly similar to that in systemic plasma, and the MGF accumulation in the liver was limited, so was that of NTR. Correspondingly, the in vitro study revealed the MGF uptake was mainly dependent on poor passive transport, possibly leading to its limited hepatic metabolism and accumulation. Moreover, the NTR exposure remained considerably low (Cmax < 3 ng/mL, AUCNTR/AUCMGF < 3%) in plasma after single MGF dosing, corresponding to its tiny proportion (0.1%) of MGF in MGF‐incubated enterobacteria samples. However, given the low generation and elimination rates of NTR, NTR might accumulate in plasma and exert effects after repeated MGF dosing, although requires further study. This work is the first systemic study on PK profiles of MGF and NTR in vitro and in vivo, which is important for the interpretation on the poor bioavailability and pharmacodynamics of MGF. © 2016 BioFactors, 42(5):533–544, 2016
Application of response surface methodology for optimization of trace amount of diazinon preconcentration in natural waters and biological samples by carbon mesoporous CMK‐3
Authors: Beirami Somayeh , Barzoki Hadi Rahimzadeh , Bahramifar Nader 
Published: October 2016

AbstractPreconcentration of trace amounts of diazinon by carbon mesoporous CMK‐3 in water and biological samples and measurement by high‐performance liquid chromatography were investigated. CMK‐3 was prepared using hexagonal SBA‐15 as the template. The synthesized materials were characterized by X‐Ray diffraction (XRD), Fourier transform infrared spectroscopy, Brunaur–Emmet–Teller, transmission electron microscopy and Boehm titration method. The preconcentration procedure was optimized using a multivariate optimization approach following a two‐stage process. The effect of analytical parameters including the amount of the CMK‐3 as an adsorbent, pH, type and volume of eluent and flow rate of eluent and sample were studied by a screening project, then the effective parameters were optimized by response surface methodology based on central composite design. The average extraction efficiency of diazinon under optimal conditions (CMK‐3 dosage = 25 mg, sample flow rate = 2.5 mL min−1, eluent flow rate = 1.25 mL min−1, volume of methanol as an eluent =3.5 mL and initial pH = 6) was 97.11%, which agrees well with the predicted response value (97.93%). The linearity of the method was in the range of 0.5–100 μg L−1 with a correlation coefficient of 0.997. Enrichment factor, limit of detection and limit of quantification were 285.7, 0.09 and 0.23 μg L−1, respectively. The relative standard deviation (RSD) under optimum conditions was 2.21% (n = 5). The proposed method was applied to determine diazinon in real water and biological samples. Recovery of diazinon from real samples was between 95.80 and 104.94% with an RSD of 0.19–4.65%. Thus, this method is suitable for the preconcentration and determination of diazinon in real water and biological samples.
Touch imprint cytology with massively parallel sequencing (TIC‐seq): a simple and rapid method to snapshot genetic alterations in tumors
Authors: Amemiya Kenji , Hirotsu Yosuke , Goto Taichiro , Nakagomi Hiroshi , Mochizuki Hitoshi , Oyama Toshio , Omata Masao 
Published: October 2016

AbstractIdentifying genetic alterations in tumors is critical for molecular targeting of therapy. In the clinical setting, formalin‐fixed paraffin‐embedded (FFPE) tissue is usually employed for genetic analysis. However, DNA extracted from FFPE tissue is often not suitable for analysis because of its low levels and poor quality. Additionally, FFPE sample preparation is time‐consuming. To provide early treatment for cancer patients, a more rapid and robust method is required for precision medicine. We present a simple method for genetic analysis, called touch imprint cytology combined with massively paralleled sequencing (touch imprint cytology [TIC]‐seq), to detect somatic mutations in tumors. We prepared FFPE tissues and TIC specimens from tumors in nine lung cancer patients and one patient with breast cancer. We found that the quality and quantity of TIC DNA was higher than that of FFPE DNA, which requires microdissection to enrich DNA from target tissues. Targeted sequencing using a next‐generation sequencer obtained sufficient sequence data using TIC DNA. Most (92%) somatic mutations in lung primary tumors were found to be consistent between TIC and FFPE DNA. We also applied TIC DNA to primary and metastatic tumor tissues to analyze tumor heterogeneity in a breast cancer patient, and showed that common and distinct mutations among primary and metastatic sites could be classified into two distinct histological subtypes. TIC‐seq is an alternative and feasible method to analyze genomic alterations in tumors by simply touching the cut surface of specimens to slides.
Identification of Small‐Molecule PHD2 Zinc Finger Inhibitors that Activate Hypoxia Inducible Factor
Authors: Arsenault Patrick R. , Song Daisheng , Bergkamp Marian , Ravaschiere Andrew M. , Navalsky Bradleigh E. , Lieberman Paul M. , Lee Frank S. 
Published: October 2016

AbstractThe prolyl hydroxylase domain (PHD) protein:hypoxia inducible factor (HIF) pathway is the main pathway by which changes in oxygen concentration are transduced to changes in gene expression. In mammals, there are three PHD paralogues, and PHD2 has emerged as a particularly critical one for regulating HIF target genes such as erythropoietin (EPO), which controls red cell mass and hematocrit. PHD2 is distinctive among the three PHDs in that it contains an N‐terminal MYND‐type zinc finger. We have proposed that this zinc finger binds a Pro‐Xaa‐Leu‐Glu (PXLE) motif found in proteins of the HSP90 pathway to facilitate HIF‐α hydroxylation. Targeting this motif could provide a means of specifically inhibiting this PHD isoform. Here, we screened a library of chemical compounds for their capacity to inhibit the zinc finger of PHD2. We identified compounds that, in vitro, can inhibit PHD2 binding to a PXLE‐containing peptide and induce activation of HIF. Injection of one of these compounds into mice induces an increase in hematocrit. This study offers proof of principle that inhibition of the zinc finger of PHD2 can provide a means of selectively targeting PHD2 to activate the HIF pathway.
Glucose‐6‐phosphate dehydrogenase deficiency: not exclusively in males
Authors: van den Broek Leonie , Heylen Evelien , van den Akker Machiel 
Published: October 2016

Key Clinical MessageGlucose‐6‐phosphate (G6PD) deficiency is the most common human enzyme defect, often presenting with neonatal jaundice and/or acute hemolytic anemia, triggered by oxidizing agents. G6PD deficiency is an X‐linked, hereditary disease, mainly affecting men, but should also be considered in females with an oxidative hemolysis.
Foam‐Structured NiO‐MgO‐Al2O3 Nanocomposites Derived from NiMgAl Layered Double Hydroxides In Situ Grown onto Nickel Foam: A Promising Catalyst for High‐Throughput Catalytic Oxymethane Reforming
Authors: Chai Ruijuan , Li Yakun , Zhang Qiaofei , Fan Songyu , Zhang Zhiqiang , Chen Pengjing , Zhao Guofeng , Liu Ye , Lu Yong 
Published: October 2016

AbstractCatalytic oxymethane reforming is an effective and efficient route to produce syngas, but the commonly used Ni catalysts suffer from coke deposition, Ni sintering, and heat‐transfer limitations. A Ni‐foam‐structured NiO‐MgO‐Al2O3 nanocomposite catalyst was developed by thermal decomposition of NiMgAl layered double hydroxides (LDHs) in situ hydrothermally grown onto the Ni‐foam. Originating from the lattice orientation effect and topotactic decomposition of the LDH precursor, NiO, MgO, and Al2O3 are highly distributed in the nanocomposite, and thus, this catalyst shows enhanced resistance to coke and sintering. At 700 °C and a gas hourly space velocity of 100 L g−1 h−1, 86.5 % methane conversion and selectivities of 91.8/88.0 % to H2/CO are achieved with stability for at least 200 h. We believe this type of tailoring strategy and the as‐obtained materials can open up new opportunities for future applications in other high‐throughput and high‐temperature reactions.
KIO3‐Catalyzed Domino C(sp2)−H Bond Sulfenylation and C−N Bond Oxygenation of Enaminones toward the Synthesis of 3‐Sulfenylated Chromones
Authors: Zhong Shanshan , Liu Yunyun , Cao Xiaoji , Wan Jie‐Ping 
Published: October 2016

AbstractWith 2‐hydroxyphenyl‐functionalized enaminones and thiophenols as the starting materials, the facile synthesis of 3‐sulfenylated chromones has been realized through a KIO3‐catalyzed domino reaction of C−H sulfenylation and subsequent C−N‐cleavage‐based C−O bond formation. The reaction was performed under transition‐metal‐free conditions in ethyl lactate, a bioavailable ecofriendly medium.
Heterogeneous Electron‐Transfer Rates for the Reduction of Viologen Derivatives at Platinum and Bismuth Electrodes in Acetonitrile
Authors: Cook Shaun K. , Horrocks Benjamin R. 
Published: October 2016

AbstractThe standard heterogeneous rate constants for the reduction of a series of viologen derivatives with a range of inter‐ring torsion angles were measured at Bi and Pt electrodes. The electrode potentials for the first one‐electron reduction of the viologens vary from −684 mV to −1070 mV vs. Ag/0.01 m Ag+; this enabled a comparison of the behaviour of metallic (Pt) and semi‐metallic (Bi) electrodes over a wide range of applied potentials. The differential capacitance (6.5 μF cm−2) of Bi/MeCN,TBAPF6 interfaces at the potential of zero charge (pzc=−0.60 V) is at least an order of magnitude greater than that calculated on the basis of the bulk Bi carrier density (3×1017 cm−3) and the differential capacitance (9.5 μF cm−2) of Pt/MeCN interfaces at their pzc (−0.43 V) is of the same order. The series of viologen derivatives exhibited simple one‐electron redox behaviour and showed similar rate constants at Pt (1.8×10−4–1.6×10−3 cm s−1) and Bi electrodes (1.1×10−4–1.9×10−3 cm s−1) after application of the Frumkin correction. These results demonstrate that the density of states at the Bi surface is much higher than in bulk. Finally, the Frumkin‐corrected standard rate constants were observed to be inversely correlated with the inter‐ring torsion angle of the viologens.
A Soft Grip: Magnesium Complexes with a Phosphine‐Modified Phosphonium Diylidic Lewis Base
Authors: Langer Jens , Kosygin Irina , Puchta Ralph , Pahl Jürgen , Harder Sjoerd 
Published: October 2016

AbstractSimple strategies to obtain magnesium complexes with the soft chelating diylidic ligand [Ph2PCHPPh2(fluorenylidene)]− (dppmflu−) were developed to evaluate the influence of the hard acid (cation) and soft base (anion) mismatch on the stability and reactivity of the formed derivatives. Deprotonation of the precursor Ph2PCH2PPh2(flu) (dppmfluH) by an alkylmagnesium derivative or magnesium amide provided access to [{Mg(dppmflu)(μ‐nBu)}2], [Mg(dppmflu){N(SiMe3)2}], and [{Mg(dppmflu)(μ‐Me)}2], which were used as starting materials for further investigations. The reaction of [{Mg(dppmflu)(μ‐nBu)}2] with PhSiH3 in the presence of THF allowed isolation of the magnesium hydride complex [{Mg(dppmflu)(μ‐H)(thf)}2] without a stabilizing nitrogen donor ligand. Prolonged heating enforced ligand redistribution and [{Mg(dppmflu)(μ‐H)(thf)}2] was converted to [Mg(dppmflu)2] and MgH2. The homoleptic derivative [Mg(dppmflu)2], in which the magnesium center is in a very soft ligand environment, can open a THF molecule by frustrated Lewis pair reactivity to give [{Mg(dppmflu)(μ‐OC4H8dppmflu)}2].
Visible‐Light Promoted Distereodivergent Intramolecular Oxyamidation of Alkenes
Authors: Ren Xiang , Guo Qihang , Chen Jianhui , Xie Hujun , Xu Qing , Lu Zhan 
Published: October 2016

AbstractThe visible‐light‐promoted diastereodivergent intramolecular oxyamination of alkenes is described to construct oxazolindinones, pyrrolidinones and imidazolidones via mild generation of primary amidyl radicals from functionalized hydroxylamines. A unique phenomenon of highly diastereoselective ring‐opening of aziridines controlled by electron sacrifices was observed. Highly diastereoselective amino alcohols derivatives were obtained efficiently through this protocol in gram scales. The mechanistic studies suggested the isolatable anti‐aziridine intermediates were generated quickly from primary amidyl radicals and the diastereoselectivities were controlled by pKa values of the electron sacrifices.
Asymmetric Morita–Baylis–Hillman Reaction: Catalyst Development and Mechanistic Insights Based on Mass Spectrometric Back‐Reaction Screening
Authors: Isenegger Patrick G. , Bächle Florian , Pfaltz Andreas 
Published: October 2016

AbstractAn efficient protocol for the evaluation of catalysts for the asymmetric Morita–Baylis–Hillman (MBH) reaction was developed. By mass spectrometric back‐reaction screening of quasi‐enantiomeric MBH products, an efficient bifunctional phosphine catalyst was identified that outperforms literature‐known catalysts in the MBH reaction of methyl acrylate with aldehydes. The close match between the selectivities measured for the forward and back reaction and kinetic measurements provided strong evidence that the aldol step and not the subsequent proton transfer is rate‐ and enantioselectivity‐determining.
Halide‐Anion Water Clusters in Cucurbit[6]uril Supramolecular Systems
Authors: Li Bo , Li Xin , Sun Xuzhuo , Wang Ning 
Published: October 2016

AbstractThree types of dihalide water clusters [X2(H2O)8]2− (X=Cl, Br) and [I2(H2O)10]2− have been observed in cucurbit[6]uril supramolecular systems with same guest. According to the single crystal data and the quantitative theory computation, with the increase of electronegativity of halide ions, dihalide water clusters become more stable. A further comparison of three kinds of guests with different molecule length but the same anions, [p‐phenylenediamine salt, hexamethylenediamine salt and N,N′‐hexamethylenebis(pyrazinylbromide)], gives the result that the dihalide water clusters collapse from 2D to 1D with the increase of the lengths.