bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ambient curable latex films and adhesives based on natural rubber bearing Acetoacetoxy functionality
Authors: Ninjan Rattanawadee , Thongnuanchan Bencha , Lopattananon Natinee , Thitithammawong Anoma , Nakason Charoen 
Published: November 2018

The study described in this paper first demonstrates that a newly modified form of natural rubber, namely graft copolymers of natural rubber with poly (acetoacetoxyethyl methacrylate), NR‐g‐PAAEM, is able to undergo a cross‐linking reaction at room temperature by reaction with a water dispersible polyisocyanate based on hexamethylene diisocyanate (poly‐HDI). Attenuated total reflectance Fourier transform infrared (ATR‐FTIR) analysis indicated that amide groups were formed by the reaction of the acetoacetyl groups (AcAc) present in the grafted poly (acetoacetoxyethyl methacrylate) (PAAEM) chains with the poly‐HDI. This observation was accompanied by a noticeable increase in the tensile strength of the NR‐g‐PAAEM latex films when adding poly‐HDI to the latex prior to film formation. DMTA analyses also revealed a shift in the tan δ peaks, corresponding to the transitions of both NR‐g‐PAAEM and free PAAEM phases, to higher temperatures. These results provide firm evidence of cross‐linking between NR‐g‐PAAEM chains by reaction with poly‐HDI during film formation under ambient conditions. Adhesives for bonding wood to wood based on the NR‐g‐PAAEM latex were then prepared, using poly‐HDI as the cross‐linker. The lap shear strength of the resulting adhesives exhibited a maximum value of 2657 KPa when a poly‐HDI:AAEM molar ratio of 3:1 was employed. It was also observed that the adhesive attained about approximately 89% of the highest lap shear strength after it was allowed to set at 30°C for 24 hours. Hence, the use of poly‐HDI in cross‐linking NR particles bearing grafted PAAEM offers great potential for developing latex adhesives and coatings capable of curing under ambient conditions.
Electrospun EGNPs reinforced precursor carbon nanofibril composites by using RSM
Authors: Zoalfakar Said H. , Mohamed Mostafa A. , El‐Hamid Mohamed A. , Ali Ashraf A. 
Published: November 2018

Response surface methodology (RSM),based on five‐level, four variable Box‐Benkhen technique was investigated for modeling the average fiber diameter of electrospun polyacrylonitrile (PAN) nanofibers. The four important electrospinning parameters were studied including applied voltage (kV), Berry's number, deposition distance from nozzle to collector (cm), and spinning angle (Ѳ in degree). The measured fiber diameters were in a good agreement with the predicted results by using RSM technique. High‐regression coefficient between the variables and the response (R2 = 87.74%) indicates excellent evaluation of experimental data by second‐order polynomial regression model. The optimum PAN average fiber diameters of 208 and 37‐nm standard deviation were collected at 19 kV, Berry's number = 10, 25° spinning angle, and 16‐cm deposition distance. The PAN/N,N‐dimethylformamide (DMF) polymer solution with the optimum weight concentration (10 wt.%) was selected to study the effect of dispersing exfoliated graphite nanoplatelets (EGNPs) in PAN/DMF solution on the electrospun EGNP/PAN fibril composite diameter. Five different EGNPs weight concentrations (2, 4, 6, 8, and 10 wt.%) were dispersed in the optimized PAN/DMF polymer solution. Morphology of EGNPs/PAN fibril composites and its distribution were investigated by scanning electron microscopy (SEM) to show the minimum fiber diameter for the above‐mentioned 5 wt. % of EGNPs. A minimum fibril composite diameter of 182 nm was obtained at 10 wt.% of EGNPs. Morphological characteristics of electrospun fibers and their distribution were tested by Raman spectroscopy, SEM, differential light scattering, and high‐resolution transmission electron microscopy.
Antifouling zwitterionic pSBMA‐MSN particles for biomedical applications
Authors: Beltrán‐Osuna Ángela A. , Ródenas‐Rochina Joaquín , Gómez Ribelles José L. , Perilla Jairo E. 
Published: November 2018

Mesoporous silica nanoparticles (MSNs) are one of the most promising nanocarriers in biomedicine. Nonetheless, surface modification has been pointed out as a condition necessary for drug delivery applications, where stability and biocompatibility are extremely important for the vehicle performance. Likewise, zwitterionic polymers are outstanding candidates in biological fields, where poly(sulfobetaine methacrylate) (pSBMA) has been widely studied. These polymers, known as antifouling materials, are able to render a surface capacity to avoid protein adhesion. In this work, a core‐shell nanocarrier was created, where pSBMA was covalently grafted by atom transfer radical polymerization (ATRP) onto a previously functionalized MSN surface. Brush morphologies with different chain lengths (
, between 6500 and 32 300) and graft densities (σpSBMA, between 0.15 and 0.51 molecules of pSBMA per nm2 of MSN) were obtained. Protein adhesion resistance was evaluated with two proteins: fibronectin (FN) and bovine serum albumin (BSA). The best nanocarrier synthesized allowed a reduction of 96% of FN and 76% of BSA adhesion (compared with an adsorption of 100% assigned to the native material). Since the influence of the brush morphology is seldom studied or reported, this work aims to comprehend how the configuration of the polymer brushes affected their antifouling capacity, in order to use this pSBMA‐MSN product for biomedical applications, notably as a possible drug delivery nanocarrier. Future work will analyze the solution behavior of the zwitterionic brushes to evaluate variations of temperature and pH values as possible mechanisms of delivery.
The influence of furanyl monomer on the self‐healing polyurethanes by reverse Diels‐Alder cross‐link
Authors: Pan Yunlin , Yu Xi , Yang Pengfei , Li Junying , Zhang Datong , Liu Lian , Wang Yongqing 
Published: November 2018

In this work, several furanyl diols with amide, imide, or amine groups were synthesized, each diol was subsequently polymerized with 4,4′‐dicyclohexylmethane diisocyanate and polytetramethylenene ether glycol to prepare polyurethanes. Bis(4‐maleimidophenyl) methane was then added as a cross‐linker to give self‐healing polyurethanes. DSC and DMA analysis were used to measure the DA/rDA temperature of these polyurethanes with different chemical structures. It was demonstrated that the polyurethane prepared from amide furanyl diol had the highest DA/rDA temperature, followed with the order of amide > imide > amine. This expands the versatility of monomers that have different self‐healing activity, which is expected to have the application for preparing various polyurethane coatings.
Validity of maternal recall of gestational age and weight at birth: Comparison of structured interview and medical records
Authors: Petersen Julie M. , Mitchell Allen A. , Van Bennekom Carla , Werler Martha M. 
Published: November 2018

AbstractPurposeTo assess agreement between maternal recall and medical records for gestational age (GA) at birth as derived from dating information and birthweight.MethodsIn the case‐control Slone Birth Defects Study, within 6 months of delivery, trained nurses conducted standardized telephone interviews with mothers of infants with and without major structural malformations. In a subset of approximately 5000 case and control mothers from five US centers (2008–2012), a research nurse abstracted subjects' medical records. GA at delivery was calculated as date of delivery minus (estimated date of confinement [EDC] minus 280); if EDC was unknown, last menstrual period served as a proxy for start of pregnancy. Positive and negative predictive values (PPV and NPV, respectively) were calculated, using medical records as the standard, for categories of GA at delivery (ie, early preterm <238, late preterm <258, and term ≥259 d) and birthweight (low <2500, normal 2500 to 4500, and high >4500 g).ResultsThe gestational age and birthweight validation samples comprised 3122 and 4760 women, respectively, with diverse characteristics. The PPV and NPV were high (>92% and >99%, respectively) for all categories of delivery GA and birthweight.ConclusionsOur findings suggest that mothers' recall may be a valid alternative to medical records to estimate delivery GA and birthweight. This study used standardized interviews conducted by trained research nurses, had a short recall period (<6 months post delivery), and for delivery GA, focused on date‐derived GA. Further research is needed on the potential impact of study design, population characteristics, and comparison to other data sources.
Evolutionary divergence of the nuclear pore complex from fungi to metazoans
Authors: Chopra Kriti , Bawaria Shrankhla , Chauhan Radha 
Published: November 2018

AbstractNuclear pore complex (NPC) is the largest multimeric protein assembly of the eukaryotic cell, which mediates the nucleocytoplasmic transport. The constituent proteins of this assembly (nucleoporins) are present in varying copy numbers to give a size from ~ 60 MDa (yeast) to 112 MDa (human) and share common ancestry with other membrane‐associated complexes such as COPI/COPII and thus share the same structural folds. However, the nucleoporins across species exhibit very low percentage sequence similarity and this reflects in their distinct secondary structure and domain organization. We employed thorough sequence and phylogenetic analysis guided from structure‐based alignments of all the nucleoporins from fungi to metazoans to understand the evolution of NPC. Through evolutionary pressure analysis on various nucleoporins, we deduced that these proteins are under differential selection pressure and hence the homologous interacting partners do not complement each other in the in vitro pull‐down assay. The super tree analysis of all nucleoporins taken together illustrates divergent evolution of nucleoporins and notably, the degree of divergence is more apparent in higher order organisms as compared to lower species. Overall, our results support the hypothesis that the protein–protein interactions in such large multimeric assemblies are species specific in nature and hence their structure and function should also be studied in an organism‐specific manner.
Tumor‐infiltrating mesenchymal stem cells: Drivers of the immunosuppressive tumor microenvironment in prostate cancer?
Authors: Krueger Timothy E. , Thorek Daniel L. J. , Meeker Alan K. , Isaacs John T. , Brennen W. Nathaniel 
Published: November 2018

BackgroundProstate cancer is characterized by T‐cell exclusion, which is consistent with their poor responses to immunotherapy. In addition, T‐cells restricted to the adjacent stroma and benign areas are characterized by anergic and immunosuppressive phenotypes. In order for immunotherapies to produce robust anti‐tumor responses in prostate cancer, this exclusion barrier and immunosuppressive microenvironment must first be overcome. We have previously identified mesenchymal stem cells (MSCs) in primary and metastatic human prostate cancer tissue.MethodsAn Opal Multiplex immunofluorescence assay based on CD73, CD90, and CD105 staining was used to identify triple‐labeled MSCs in human prostate cancer tissue. T‐cell suppression assays and flow cytometry were used to demonstrate the immunosuppressive potential of primary MSCs expanded from human bone marrow and prostate cancer tissue from independent donors.ResultsEndogenous MSCs were confirmed to be present at sites of human prostate cancer. These prostate cancer‐infiltrating MSCs suppress T‐cell proliferation in a dose‐dependent manner similar to their bone marrow‐derived counterparts. Also similar to bone marrow‐derived MSCs, prostate cancer‐infiltrating MSCs upregulate expression of PD‐L1 and PD‐L2 on their cell surface in the presence of IFNγ and TNFα.ConclusionProstate cancer‐infiltrating MSCs suppress T‐cell proliferation similar to canonical bone marrow‐derived MSCs, which have well‐documented immunosuppressive properties with numerous effects on both innate and adaptive immune system function. Thus, we hypothesize that selective depletion of MSCs infiltrating sites of prostate cancer should restore immunologic recognition and elimination of malignant cells via broad re‐activation of cytotoxic pro‐inflammatory pathways.
Sox7 negatively regulates prostate‐specific membrane antigen (PSMA) expression through PSMA‐enhancer
Authors: Peng Wei , Guo Lizheng , Tang Ruoyi , Liu Xiuju , Jin Rui , Dong Jin‐Tang , Xing Chun‐gen , Zhou Wei 
Published: November 2018

BackgroundPSMA expression in the prostate epithelium is controlled by a cis‐element, PSMA enhancer (PSME). PSME contains multiple binding sites for Sox proteins, and in this study, we identified Sox7 protein as a negative regulator of PSMA expression through its interaction with PSME.MethodsThe statistical correlation between Sox7 and PSMA mRNA expression was evaluated using five prostate cancer studies from cBioportal. In vitro and in vivo interaction between Sox7 and PSME was evaluated by chromatin immunoprecipitation (ChIP), electrophoretic mobility shift assay (EMSA), and luciferase reporter assay. Synthetic oligonucleotides were generated to define the sites in PSME that interact with Sox7 protein. Sox7 mutants were generated to identify the region of this protein required to regulate PSMA expression. Sox7 was also stably expressed in LNCaP/C4‐2 and 22Rv1 cells to validate the regulation of PSMA expression by Sox7 in vivo.ResultsSox7 mRNA expression negatively correlated with PSMA/FOLH1 and PSMAL/FOLH1B mRNA expression in Broad/Cornell, TCGA and MSKCC studies, but not in two studies containing only metastatic prostate tumors. PC‐3 cells mostly expressed the 48.5 KDa isoform 2 of Sox7, and the depletion of this isoform did not restore PSMA expression. Ectopic expression of canonical, wild‐type Sox7 in C4‐2 and 22Rv1 cells suppressed PSMA protein expression. ChIP assay revealed that canonical Sox7 protein preferentially interacts with PSME in vivo, and EMSA identified the SOX box sites #2 and #4 in PSME as required for its interaction. Sox7 was capable of directly binding to PSME and suppressed PSME‐mediated transcription. The NLS regions of Sox7, but not its β‐catenin interacting motif, are essential for this suppressing activity. Furthermore, restoration of wild‐type Sox7 expression but not Sox7‐NLS mutant in Sox7‐null prostate cancer cell lines suppressed PSMA expression.ConclusionsThe inactivation of canonical Sox7 is responsible for the upregulated expression of PSMA in non‐metastatic prostate cancer.
Experimental rat prostatitis caused by Trichomonas vaginalis infection
Authors: Jang Ki‐Seok , Han Ik‐Hwan , Lee Seung‐Ju , Yoo Jin , Kim Ye‐Seul , Sim Seobo , Ryu Jae‐Sook 
Published: November 2018

BackgroundTrichomonas vaginalis (T. vaginalis) is the most common sexually transmitted parasite. It has been detected in prostatic tissue of patients with prostatitis and reported to be associated with chronic prostatitis and benign prostatic hyperplasia as well as prostate cancer. Recently, experimental rodent models of prostatitis induced by pathogen infection have been developed. However, there have so far been no reports of prostatitis caused by T. vaginalis infection in animals. Here, we investigated whether infection with T. vaginalis via the rat urethra could cause prostatitis.MethodsT. vaginalis was injected into prostate through urethra of rat (Wistar rats), and the rats were killed 1, 2, or 4 weeks later. The presence of T. vaginalis trophozoites in the rat prostates was examined by immunohistochemistry, and pathological changes of the prostate were observed by hematoxylin‐eosin staining and evaluated by grading from 0 to 5 for inflammatory cell infiltration, acinar changes, and interstitial fibrosis. Infiltrated mast cells were observed by toluidine blue staining of rat prostate tissue. Chemokine C‐C motif ligand 2 (CCL2) levels of the rat prostates were measured by ELISA.ResultsT. vaginalis trophozoites were observed in acini in the prostates of the injected rats. The prostate tissues had higher pathological scores, and 83% (5/6) and 100% (6/6) of the ventral and dorsolateral lobes (n = 6), respectively, were inflamed. Infiltration and degranulation of mast cells were observed at higher rates in prostate sections of the T. vaginalis‐infected rats. Also, prostate tissues of the injected rats had increased CCL2 levels.ConclusionsInjection of T. vaginalis in rats caused prostatitis as revealed by pathologic changes, mast cell infiltration and increased CCL2 production. Therefore, this study provides the first evidence that T. vaginalis infection in rats causes prostatitis.
Antifungal activity of a de novo synthetic peptide and derivatives against fungal food contaminants
Authors: Thery Thibaut , Shwaiki Laila N. , O'Callaghan Yvonne C. , O'Brien Nora M. , Arendt Elke K. 
Published: November 2018

The development of novel solutions to fight microbial food contaminants rests upon two pillars, which are the development of resistant strains and consumers' desire for a reduced consumption of synthetic drugs. Natural antimicrobial peptides possess the qualities to overcome these issues. De novo synthesis of novel antifungal compounds is a major progress that has been facilitated by the identification of parameters involved in the antimicrobial activity. A 14‐residue peptide named KK14, with the sequence KKFFRAWWAPRFLK‐NH2, was designed and inhibited conidial germination and fungal growth of food contaminants within the range 6.25 to 50 μg/ml and 6.25 to 100 μg/ml, respectively. The study of three analogues of the peptide highlighted the role of some residues in the structural conformation of the peptide and its antifungal activity. The substitution of a Pro residue with Arg increased the helical content of the peptide not only its antifungal activity but also its cytotoxicity. The insertion of an unnatural bulky residue β‐diphenylalanine or a full d‐enantiomerization overall increased the antifungal potency. The four peptides showed similar behaviour towards salt increase, heat treatment, and pH decrease. Interestingly, the denantiomer remained the most active at high pH and after proteolytic digestion. The four peptides did not present haemolytic activity up to 200 μg/ml but had different behaviours of cytotoxicity. These differences could be crucial for potential application as pharmaceutical or food preservatives.
Influence of river discharge on grass carp occupancy dynamics in south‐eastern Iowa rivers
Authors: Sullivan Christopher J. , Weber Michael J. , Pierce Clay L. , Camacho Carlos A. 
Published: November 2018

AbstractDespite the longstanding presence of grass carp Ctenopharyngodon idella in the Upper Mississippi River (UMR) watershed, information regarding their populations remains largely unknown, in part because capture is difficult. Occupancy models are a popular wildlife assessment tool to account for imperfect detections but have been slow to be adopted in fisheries. Herein, we used occupancy modelling to evaluate the influence of two environmental covariates (river discharge and water temperature) on grass carp occupancy, extinction, colonization, and detection at nine sites within south‐eastern Iowa rivers from April to October 2014 and 2015. Grass carp were detected at least once at all but one site. The most parsimonious model indicated that grass carp colonization probability increased from 0.15 to 0.67 with increases in river discharge. In contrast, occupancy (0.20), extinction (0.29), and detection (0.50) probabilities were temporally constant. Models indicated that water temperatures did not influence grass carp extinction or colonization probabilities relative to river discharge. Cumulative grass carp detection probability approached 1.0, whereas conditional occupancy estimates were less than 0.1 when using five or more sampling transects. The use of a robust design occupancy model allowed us to estimate site occupancy rates of grass carp corrected for imperfect detections, while demonstrating the importance of river discharge for site colonization. These results can be used to assess the distribution of a cryptic fish while helping to guide grass carp sampling and removal efforts.
Production of N‐doped Reduced Graphene Oxide/Fe3O4 Hybrids and Effect of Order of Production Steps on Electrocatalytic Performances for Oxygen Reduction Reaction
Authors: Shin Yunseok , Lee Seungjun , Park Sunghee , Jang Dawoon , Lim Donggyu , Park Gilsoo , Seok Sujin , Park Sungjin 
Published: November 2018

AbstractOxygen reduction reactions (ORRs) occur at cathodes in fuel cells and require efficient electrocatalysts. Because of the cost and limited durability and stability of commercial Pt/C catalysts, the development of efficient Pt‐free electrocatalysts is an active research topic. Here, we describe the solution‐based production of Fe3O4 nanoparticles/N‐doped graphene‐based materials from FeCl2, graphene oxide (G−O), and hydrazine. Orders of production steps were varied by; i) reacting FeCl2 and G−O first and then adding hydrazine (Fe/G−N), ii) reacting G−O, FeCl2, and hydrazine at the same time (Fe/G/N), or iii) reacting G−O and hydrazine first and then adding FeCl2 (G/N−Fe). The hybrids produced showed better ORR electrocatalytic activity in alkaline media than single components such as N‐doped graphene‐based materials or Fe3O4. Furthermore, the electrocatalytic properties of the resulting hybrids were found to depend on orders of addition. Fe/G/N was found to be the best electrocatalyst and had better onset and half‐wave potentials, thermodynamic current density, and 4‐electron selectivity. All three hybrids show good cyclic durability and methanol tolerance.
Semisynthesis and Biological Evaluation of Platensimycin Analogues with Varying Aminobenzoic Acids
Authors: Tian Kai , Deng Youchao , Qiu Lin , Zhu Xiangcheng , Shen Ben , Duan Yanwen , Huang Yong 
Published: November 2018

AbstractPlatensimycin (PTM) is an excellent natural product drug lead against various gram‐positive pathogens, including methicillin‐resistant Staphylococcus aureus and vancomycin‐resistant enterococci. In this study, twenty PTM derivatives with varying aminobenzoic acids were semisynthesized. In contrast to all the previous reported inactive aminobenzaote analogues, a few of them showed moderate antibacterial activities against S. aureus. Our study suggested that modification of the conserved aminobenzoic acid remains a viable approach to diversify the PTM scaffold.
Catalytic Performance and Kinetics Study over Novel Ni/Activated Carbon‐FSM‐16 Catalysts in the BTX Mixture for Benzene Selective Hydrogenation
Authors: Mohammadian Zahra , Peyrovi Mohammad Hasan , Parsafard Nastaran 
Published: November 2018

AbstractNickel catalysts supported on activated carbon/FSM‐16 nanoparticles were prepared by wet impregnation method and tested for vapor phase selective hydrogenation of benzene in the mixture of aromatics as benzene, toluene and xylene. The textural and physico‐chemical properties of nickel catalysts were characterized by X‐ray diffraction, X‐ray fluorescence, Fourier transform infrared spectroscopy, Uv‐visible diffuse reflectance spectra, field emission scanning electron microscope and nitrogen adsorption‐desorption analysis. The catalytic evaluation revealed that the best activity (>94%) and high selectivity (>99%) are related to Ni/AC−F(50) at 150 °C and Ni/AC−F(75) at 130 °C and 150 °C, respectively. In summary, by calculating the yield of benzene, in order to evaluate the performance (activity, stability, and selectivity) of the catalysts, it was found that the performance of Ni/AC−F(75) is very appropriate.