bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of wheat, rye, and triticale straw on the properties of natural rubber composites
Authors: Masłowski Marcin , Miedzianowska Justyna , Strzelec Krzysztof 
Published: March 2018

AbstractThe article presents unreported yet in the subject literature results of the research that aim was the examinations of the effect of wheat, rye, and triticale straws obtained from three different fragmentation methods, on the properties of natural rubber composites. Sieve analysis was performed to produce composites with variable filler size fractions. Characterization of mechanical and damping properties, tear strength, hardness, thermo‐oxidative aging performance, and cross‐linking density of obtained biocomposites were reported and studied. It was found that straw fillers with different particle size and shape significantly affected properties of natural rubber composites. The addition of filler (in an appropriate amount and degree of fragmentation) modified natural rubber biocomposites, improving mechanical and physical properties of composites or the ability to damp under the influence of compression stress.
Dynamics and structure development for biaxial stretching polyamide 6 films
Authors: Kanai Toshitaka , Okuyama Yoshimune , Takashige Masao 
Published: March 2018

AbstractThe biaxial stretching film of polyamide 6 (PA6) is widely used for food and industrial products packaging. It is expected to improve stretchability, impact strength, tensile strength, and thermoformability for a larger market. So, in this research, the stretching methods were investigated in terms of dynamics and structure development for the biaxial stretching films. There are three different stretching methods which can produce PA6 films, namely the simultaneous biaxial stretching, the sequential biaxial stretching, and the double bubble tubular process. The physical properties of PA6 film are very much influenced by the biaxial stretching process. But there are no reports which described the difference among the three stretching methods and film properties. For this reason, the higher order structure and stretching behaviors of the three stretching methods were studied. As a result, the sequential biaxial stretching showed strong stretched effect and molecular orientation in the transverse direction (TD) and poor film thickness uniformity, because the strong hydrogen bonds were created during the machine direction (MD) stretching and high stretching stress in the TD stretching was required. In the simultaneous biaxial stretching, the molecular orientation was equal both in the MD and in the TD of the stretched plane. The double bubble tubular process produced well‐balanced film and equal orientation in any direction in terms of the phase difference in the plane of film. The biaxially oriented PA6 film having good stretchability and high physical properties was also investigated.
An Efficient Synthesis of exo/endo‐Hydroxylated Cyclohexenones by Thiol/Amine‐Mediated Tandem Aldol–[2,3]‐Sigmatropic Rearrangement: Amine‐Dependent Complementary Regioselectivity
Authors: Miura Motofumi , Nakakita Toshinori , Toriyama Masaharu , Motohashi Shigeyasu 
Published: March 2018

Abstractexo/endo‐Hydroxylated cyclohexenones are essential synthetic intermediates for a variety of biologically active compounds. However, methods that lead to efficient and selective preparation of exo/endo‐hydroxylated cyclohexenones remain to be established. Herein, we report the practical and scalable synthesis of exo/endo‐hydroxylated cyclohexenones from readily available 2,6‐diketosulfoxides. We demonstrate that endo and exo geometric isomers of hydroxylated cyclohexenones can be obtained by simple modification of the reaction conditions.
Kohlenstoff‐Nanozyme: Enzymatische Eigenschaften, Katalysemechanismen und Anwendungen
Authors: Sun Hanjun , Zhou Ya , Ren Jinsong , Qu Xiaogang 
Published: March 2018

AbstractNanozyme haben spezifische Vorteile gegenüber natürlichen Enzymen, wie ihre einfache Produktion in großen Mengen, lange Lagerzeiten, niedrige Kosten und hohe Stabilität unter harschen Umgebungen. Kohlenstoffnanomaterialien (CNMs), einschließlich Fullerenen, Kohlenstoffnanoröhren, Graphen, Kohlenstoffquantenpunkten und Graphenquantenpunkten, sind zu einer herausragenden Substanzfamilie in den Materialwissenschaften geworden. Über die katalytischen Aktivitäten von CNMs und ihren Hybridverbindungen als eine neue Klasse von Nanozymen wurde ausführlich berichtet. In diesem Kurzaufsatz werden die jüngsten Fortschritte bei CNM‐basierten künstlichen Enzymen zusammengefasst, mit einem Schwerpunkt auf ihrer Peroxidase‐artigen Aktivität. Die enzymatischen Eigenschaften, Katalysemechanismen und neuartige Anwendungen von CNM‐Nanozymen in der Sensorik, der Therapie und der Umwelttechnologie werden diskutiert. Darüber hinaus thematisieren wir die verbleibenden Herausforderungen und ungelöste Probleme. Einhergehend mit dem raschen Voranschreiten der Bionanotechnologie haben die einzigartigen enzymatischen Eigenschaften der CNM‐Nanozyme viel Aufmerksamkeit erfahren, und sie werden auch in Zukunft ein aktives Forschungsfeld darstellen.
Optimization of biodegradable PEG/PLGA nanofiber mats electrospinning process for anti‐adhesion application
Authors: Zhao Yue , Zhu Jinhui , Zhang Junhui , Chen Zaomei , Li Weida , Deng Lejun , Chen Kejun , Wan Huayin , Li Jian , Li Rubing 
Published: March 2018

ABSTRACTElectrospinning is a direct, continuous, and useful technique to prepare nanofiber by applying electrostatic forces. In this study, poly(lactic‐co‐glycolic acid)/poly(ethylene glycol) (PLGA/PEG) nanofiber mats were prepared, and electrospinning process was optimized to obtain appropriate fiber diameter and hydrophilicity for anti‐adhesion application. Optimization of applied voltage, PEG content, and feeding rate was investigated using response surface methodology. A total of 15 trials were designed to optimize the parameters. Fiber diameter was measured using scanning electron microscopy. Individual and interactive effects of the solution properties were determined. Moreover, the adequacy of the models was verified by validation experiments. For anti‐adhesion test, a nanofiber mat was produced based on the suggested optimum electrospinning conditions. Results showed that optimum fiber diameters were obtained using 7.5% PEG content, applied voltage of 19 kV, and flow rate of 3 mL/h. Experimental results were in good agreement with the predicted fiber diameters. Furthermore, a rat model of sidewall defect‐cecum abrasion was employed to investigate the efficacy of PEG/PLGA in preventing postoperative peritoneal adhesions. Hence, this study provides an overview on the fabrication of PLGA/PEG nanofibers with targeted diameter, which may be used in anti‐adhesion. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46282.
Wood‐based composites with thermoplastic polyurethane as matrix polymer
Authors: Diestel Sylvia , Krause Andreas 
Published: March 2018

ABSTRACTThis research reports the influence of the mechanical properties of thermoplastic polyurethane (TPU) as a function of wood filler percentage. Wood flour was mixed with two different chemically based TPUs. Also, moisture content during compounding process as well as the origin of moisture (wood or TPU) were studied. All experimental designs and statistical analysis were done with the software Design Expert Version 10. Composite preparation took place in a multi‐stage process. The results showed that 70% wood filler can be incorporated in the composite manufacture. The properties of the composite were mainly influenced by the proportion of wood and TPU. Wood flour increased the density, hardness, water absorption, and tensile modulus with a decrease in impact resistance and abrasion resistance of the composite. Tensile strength exhibited a decrease up to ∼35% wood content, but an increase with further addition of wood. Moisture content had only a minor influence on the mechanical and water absorption properties despite the noted severe moisture sensitivity of TPU, which usually leads to decline in mechanical properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46344.
Systematically engineering Escherichia coli for enhanced shikimate biosynthesis co‐utilizing glycerol and glucose
Authors: Bilal Muhammad , Yue Shengjie , Hu Hongbo , Wang Wei , Zhang Xuehong 
Published: March 2018

AbstractIn this study, an Escherichia coli strain with the capability to utilize glycerol/glucose simultaneously was genetically engineered to produce high shikimate. To achieve this, the ptsG gene encoding EIICBglc protein was inactivated in the BW25113 strain to alleviate carbon catabolite repression. The shikimate kinase genes aroK and aroL were also eliminated to construct the SA‐B2 strain, which led to a 42.3% increase in shikimate production. Thereafter, three critical genes, namely mutant aroGfbr, ppsA, and tktA, were overexpressed in strain SA‐B2, and the resulting engineered SA‐B7 strain produced 0.92 g/L shikimate in shake flask cultures, which were 2.5 times higher than strain SA‐B2. The influence of varying carbon mole numbers ratios of glycerol to glucose on the production of shikimate was also investigated, where the highest shikimate production was attained at a glycerol‐to‐glucose ratio of 12:1 by SA‐B7. Moreover, the amount of NADPH was 3.5‐times higher in the mixed culture medium as compared to sole glycerol‐based medium. RT‐PCR data indicated that the addition of glucose upregulated the transcriptional levels of genes pertaining to shikimate biosynthesis. In conclusion, the findings demonstrated that E. coli could be modified as a potential cell factory to produce shikimate and other high‐value derived aromatic compounds by genetic and metabolic engineering strategies. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd
Nutrient intake in women before conception and risks of anophthalmia and microphthalmia in their offspring
Authors: Weber Kari A. , Yang Wei , Carmichael Suzan L. , Shaw Gary M. ,   National Birth Defects Prevention Study
Published: March 2018

BackgroundWe previously explored associations between nutrients including folate and other macro and micronutrients and risks of anophthalmia or microphthalmia in the National Birth Defects Prevention Study. In the current study, we expand those previous results with larger sample sizes and conduct analyses with an additional diet quality index using more recent data.MethodsThe National Birth Defects Prevention Study is a population‐based, multicenter case‐control study of over 30 major birth defects, with estimated due dates from October 1997 to December 2011. Cases were 224 infants diagnosed with anophthalmia or microphthalmia. Controls were 11,109 live‐born, nonmalformed infants randomly selected by each study center. Mothers completed a standardized, computer‐assisted telephone interview between 6 weeks and 24 months after delivery. Mothers responded to a shortened food frequency questionnaire, assessing their nutrient intake for the year before pregnancy, and questions about periconceptional (2 months before to 2 months after conception) vitamin supplement use. Nutrient intake quartiles were based on the intake among controls.ResultsAmong vitamin supplement users, odds of anophthalmia/microphthalmia were decreased for women with intake levels in the highest quartile of folate (0.56, 95% confidence interval [CI] 0.32–0.98), magnesium (0.42, 95% CI 0.22–0.82), and vitamin E (0.50, 95% CI 0.29–0.89). Among women not reporting vitamin supplement use, the odds were significantly increased for beta‐carotene (2.5, 95% CI 1.10–5.68) and decreased for retinol (0.37, 95% CI 0.19–0.73).ConclusionsIn this expanded analysis, we observed associations for a few nutrients, specifically forms of vitamin A. However, the heterogeneity of results by form and vitamin use necessitates further inquiry.
Quantitative determination of meloxicam in dog plasma by high performance liquid chromatography–tandem mass spectrometry and its application in a pharmacokinetic study
Authors: Tian Yongzhi , Wu Xiao , Zhang Mingjie , Zhao Longshan , Xiong Zhili , Qin Feng 
Published: March 2018

AbstractA rapid, selective and sensitive high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS) method was developed to determine meloxicam in beagle dog plasma. Sample pretreatment involved a one‐step protein precipitation with methanol of 0.1 mL plasma. Analysis was performed on a Venusil ASB‐C18 column with mobile phase consisting of methanol–water (containing 0.1% formic acid) (75:25, v/v). The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring mode via electrospray ionization source. Each plasma sample was chromatographed within 4.1 min. The linear calibration curves for meloxicam was obtained in the concentration range of 10.3–4.12 × 103 ng/mL (r ≥ 0.99). The intra‐ and inter‐day precisions (relative standard deviation) were ≤ 15%, and accuracy (relative error) was within ±7.3%. The method herein described was fully validated and successfully applied to the pharmacokinetic study of meloxicam tablets in beagle dog.
A single liquid chromatography–quadrupole time‐of‐flight mass spectrometric method for the quantification of total antibody, antibody‐conjugated drug and free payload of antibody–drug conjugates
Authors: Byeon Jin‐Ju , Park Min‐Ho , Shin Seok‐Ho , Lee Byeong ill , Park Yuri , Choi Jangmi , Kim Nahye , Kang Yeonjae , Shin Young G. 
Published: March 2018

AbstractA single hybrid affinity‐captured‐LC‐TOF‐MS/MS method was developed and applied for the quantification of total antibody, antibody conjugated drug and free payload of antibody drug conjugate (ADC). Adcetris®, a valine–citrulline monomethyl auristatin E conjugated ADC, was used as a model ADC compound. A quadratic regression (weighted 1/concentration) was used to fit calibration curves over the concentration range 30.65–613.00 ng/mL with an equation y = ax2 + bx + c for the antibody‐conjugated drug of Adcetris®. The qualification run met the acceptance criteria of ±25% accuracy and precision values for quality control samples. For the analysis of total antibody, a signature peptide (TTPPVLDSDGSFFLYSK, molecular weight 1874) was used after affinity capture using magnetic beads and on‐bead trypsin digestion. A quadratic regression (weighted 1/concentration) was used to fit calibration curves over the concentration range 5.00–100.00 μg/mL with an equation y = ax2 + bx + c for total antibody. For free payload analysis of monomethyl auristatin E, a protein precipitation method followed by LC‐TOF‐MS/MS analysis was used. A quadratic regression (weighted 1/concentration) was used to fit calibration curves over the concentration range 1.01–2200 ng/mL with an equation y = ax2 + bx + c for free payload. Pharmacokinetic study samples and in vitro stability samples in rat were successfully analyzed by this a hybrid affinity‐captured‐LC‐TOF‐MS/MS method. This single platform method is a useful complementary method for the pharmacokinetics study of ADC with valine–citrulline linker at the early drug discovery stage.
Improving the Activity and Stability of Human Galactokinase for Therapeutic and Biotechnological Applications
Authors: McAuley Margaret , Mesa‐Torres Noel , McFall Aisling , Morris Sarah , Huang Meilan , Pey Angel L. , Timson David J. 
Published: March 2018

AbstractGalactokinase catalyses the site‐ and stereospecific phosphorylation of α‐d‐galactose. As such it has attracted interest as a biocatalyst for the introduction of phosphate groups into monosaccharides. However, attempts to broaden the substrate range of human galactokinase have generally resulted in substantially reduced activity. The enzyme also has biotechnological potential in enzyme replacement therapy (ERT) for type II galactosaemia. The return‐to‐consensus approach can be used to identify residues that can be altered to increase protein stability and enzyme activity. This approach identified six residues of potential interest in human galactokinase. Some of the single consensus variants (M60V, D268E, A334S and G373S) increased the catalytic turnover of the enzyme, but none resulted in improved stability. When all six changes were introduced into the protein (M60V/M180V/D268E/A334S/R366Q/G373S), thermal stability was increased. Molecular dynamics simulations suggested that these changes altered the protein's conformation at key sites. The number of salt bridges and hydrogen bonds was also increased. Combining the six consensus variations with Y379W (a variant with greater substrate promiscuity) increased the stability of this variant and its turnover towards some substrates. Thus, the six consensus variants can be used to stabilise catalytically interesting variants of human galactokinase and might also be useful if the protein were to be used in ERT.
Invasive tracheobronchial aspergillosis developed during radioimmunotherapy for malignant lymphoma
Authors: Sato Shuku , Tamai Yotaro , Sugimoto Hideyasu , Watanabe Shinji , Kumagae Tomohiro , Kannbe Emiko , Tanaka Eri 
Published: March 2018

Key Clinical MessageInvasive pulmonary aspergillosis (IPA) often occurs during the treatment of malignant lymphoma. However, invasive tracheobronchial aspergillosis (ITBA) is a rare form of IPA. Particularly, due to the decrease in immunity associated with chemotherapy, it is difficult to diagnose ITBA only by CT imaging and serological findings. Pathologic diagnosis by bronchoscopy is important.
Synthesis and Characterization of the Perthiatriarylmethyl Radical and Its Dendritic Derivatives with High Sensitivity and Selectivity to Superoxide Radical
Authors: Tan Xiaoli , Tao Shanqing , Liu Wenbo , Rockenbauer Antal , Villamena Frederick A. , Zweier Jay L. , Song Yuguang , Liu Yangping 
Published: March 2018

AbstractEPR spectroscopy, coupled with the use of tetrathiatriarylmethyl (TAM) radicals, has been a reliable method to detect the superoxide radical (O2.−). However, the specificity and biocompatibility of TAM radicals need to be further improved. Although derivatization may overcome the drawbacks of current TAM radicals, esterification or amidation through the carboxylic groups greatly changes their redox properties and makes them inert to O2.−. Herein, the synthesis of a perthiatriarylmethyl (PST) radical and its dendritic derivatives, PST‐TA and PST‐NA, in which PST is covalently linked with dendrons containing three (TA) and nine (NA) carboxylic acids, respectively. The results show that PST rapidly reacts with O2.− to yield a unique quinone methide product. Dendritic modification of PST slightly decreases the reactivities of PST‐TA and PST‐NA, but notably increases their biostability toward various oxidoreductants. The detection limit of PST‐NA to O2.− was estimated to be 2.1 nm min−1 over 60 min of detection. Importantly, PST‐NA shows threefold higher sensitivity to O2.− in the presence and absence of ascorbic acid than that of the classic spin‐trapping technique. In addition, the application of PST‐NA to detect extracellular O2.− generation in stimulated RAW 264.7 macrophages was also explored. This study demonstrates that PST‐NA has great potential for specific detection and quantitation of O2.− in extracellular sites.
Protecting‐Group‐Free Amidation of Amino Acids using Lewis Acid Catalysts
Authors: Sabatini Marco T. , Karaluka Valerija , Lanigan Rachel M. , Boulton Lee T. , Badland Matthew , Sheppard Tom D. 
Published: March 2018

AbstractAmidation of unprotected amino acids has been investigated using a variety of ‘classical“ coupling reagents, stoichiometric or catalytic group(IV) metal salts, and boron Lewis acids. The scope of the reaction was explored through the attempted synthesis of amides derived from twenty natural, and several unnatural, amino acids, as well as a wide selection of primary and secondary amines. The study also examines the synthesis of medicinally relevant compounds, and the scalability of this direct amidation approach. Finally, we provide insight into the chemoselectivity observed in these reactions.
Salt‐Free Strategy for the Insertion of CO2 into C−H Bonds: Catalytic Hydroxymethylation of Alkynes
Authors: Wendling Timo , Risto Eugen , Krause Thilo , Gooßen Lukas J. 
Published: March 2018

AbstractA copper(I) catalyst enables the insertion of carbon dioxide into alkyne C−H bonds by using a suitable organic base with which hydrogenation of the resulting carboxylate salt with regeneration of the base becomes thermodynamically feasible. In the presence of catalytic copper(I) chloride/4,7‐diphenyl‐1,10‐phenanthroline, polymer‐bound triphenylphosphine, and 2,2,6,6‐tetramethylpiperidine as the base, terminal alkynes undergo carboxylation at 15 bar CO2 and room temperature. After filtration, the ammonium alkynecarboxylate can be hydrogenated to the primary alcohol and water at a rhodium/molybdenum catalyst, regenerating the amine base. This demonstrates the feasibility of a salt‐free overall process, in which carbon dioxide serves as a C1 building block in a C−H functionalization.
Catalytic [1,3] O‐to‐C Rearrangement: Rapid Access to Bridged Bicyclic Systems
Authors: Zhang Jiantao , Liao Zhehui , Chen Lianfen , Jiang Huanfeng , Zhu Shifa 
Published: March 2018

AbstractA catalytic [1,3] O‐to‐C rearrangement from enyne‐ethers was developed for the rapid synthesis of diverse bridged bicyclic systems. In this reaction, a vinyl oxonium intermediate, generated in situ from enyne‐ether, was the precursor for the [1,3] O‐to‐C rearrangement. This versatile protocol represents the first example of catalytic [1,3] O‐to‐C rearrangement based on ring‐expansion strategy, enabling efficient access to bridged bicyclic scaffolds.
Encapsulation Efficiency and Release Behavior of Fat Microcapsules with Lipophilic Emulsifiers
Authors: Scholz Rebecca , Davico Luca , Jakobi Victoria , Kareth Sabine , Rosenhahn Axel , Weidner Eckhard 
Published: March 2018

AbstractVerkapselte Systeme sind vor allem für die Lebensmittelindustrie und Pharmazie von großer Bedeutung. Die Herausforderung bei der Herstellung von Mikrokapseln liegt darin, eine möglichst große Menge an verkapseltem Material zu erreichen und das Freisetzungsverhalten des verkapselten Materials zu kontrollieren. In dieser Studie werden zwei lipophile Emulgatoren und deren Einfluss auf die Verkapselungseffizienz sowie das Freisetzungsverhalten der erhaltenen Mikrokapseln, bestehend aus einem Hartfett und einer Salzlösung, hinsichtlich der Freisetzung in wässriger Umgebung gegenübergestellt.
Synthesis and Biological Evaluation of Imidazole‐Bearing α‐Phosphonocarboxylates as Inhibitors of Rab Geranylgeranyl Transferase (RGGT)
Authors: Joachimiak Łukasz , Marchwicka Aleksandra , Gendaszewska‐Darmach Edyta , Błażewska Katarzyna M. 
Published: March 2018

AbstractRab geranylgeranyl transferase (RGGT) is an interesting therapeutic target, as it ensures proper functioning of Rab GTPases, a class of enzymes responsible for the regulation of vesicle trafficking. Relying on our previous studies, we synthesized a set of new α‐phosphonocarboxylic acids as potential RGGT inhibitors, with emphasis on the elaboration of imidazole‐containing analogues. We identified two compounds with activity similar to that of previously reported RGGT inhibitors, showing structural similarity to imidazo[1,2‐a]pyridine‐containing analogues in terms of their substitution pattern. Interestingly, analogues of the N‐series, derived from another phosphonocarboxylate RGGT inhibitor, 2‐fluoro‐3‐(1H‐imidazol‐1‐yl)‐2‐phosphonopropanoic acid, turned out to be inactive in our model, indicating that an additional substituent localized at positions C2 or C4 of the imidazole ring, may adversely affect the potency against the targeted enzyme.