bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of an Amine‐Terminated AB2‐Type Hyperbranched Polymer and Its Application in Dyeing of Poly(ethylene terephthalate) Fabric with Acid Dye
Authors: Hasanzadeh Mahdi , Moieni Tahereh , Hadavi Moghadam Bentolhoda 
Published: March 2013

ABSTRACTA hyperbranched, functional, water‐soluble, and amine‐terminated polymer is synthesized using a melt polycondensation reaction of methyl acrylate and diethylene triamine. The polymer is then characterized by FTIR and NMR spectroscopy. The polymer is soluble in some polar solvents. Poly(ethylene terephthalate) (PET) fabric as well as the fabric hydrolyzed by sodium hydroxide is treated with the polymer. A significant improvement in dyeability of PET fabric treated by the polymer with acid dye (C.I. Acid Red 114) is observed. The color characteristics of the dyed samples are evaluated using the CIELAB method. The results, obtained from dyed samples with conventional dyeing, reveal that a hyperbranched polymer, as indicated by the zeta potential measurements, offers positively charged amino groups leading to higher dye uptake. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2013, 32, 21345; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21345
Application of Nanoparticle Antioxidants to Enable Hyperstable Chloroplasts for Solar Energy Harvesting
Authors: Boghossian Ardemis A. , Sen Fatih , Gibbons Brenna M. , Sen Selda , Faltermeier Sean M. , Giraldo Juan Pablo , Zhang Cathy T. , Zhang Jingqing , Heller Daniel A. , Strano Michael S. 
Published: March 2013

AbstractThe chloroplast contains densely stacked arrays of light‐harvesting proteins that harness solar energy with theoretical maximum glucose conversion efficiencies approaching 12%. Few studies have explored isolated chloroplasts as a renewable, abundant, and low cost source for solar energy harvesting. One impediment is that photoactive proteins within the chloroplast become photodamaged due to reactive oxygen species (ROS) generation. In vivo, chloroplasts reduce photodegradation by applying a self‐repair cycle that dynamically replaces photodamaged components; outside the cell, ROS‐induced photodegradation contributes to limited chloroplast stability. The incorporation of chloroplasts into synthetic, light‐harvesting devices will require regenerative ROS scavenging mechanisms to prolong photoactivity. Herein, we study ROS generation within isolated chloroplasts extracted from Spinacia oleracea directly interfaced with nanoparticle antioxidants, including dextran‐wrapped nanoceria (dNC) previously demonstrated as a potent ROS scavenger. We quantitatively examine the effect of dNC, along with cerium ions, fullerenol, and DNA‐wrapped single‐walled carbon nanotubes (SWCNTs), on the ROS generation of isolated chloroplasts using the oxidative dyes, 2’,7’‐ dichlorodihydrofluorescein diacetate (H2DCF‐DA) and 2,3‐bis(2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐2H‐tetrazolium‐5‐carboxanilide sodium salt (XTT). Electrochemical measurements confirm that chloroplasts processed from free solution can generate power under illumination. We find dNC to be the most effective of these agents for decreasing oxidizing species and superoxide concentrations whilst preserving chloroplast photoactivity at concentrations below 5 μM, offering a promising mechanism for maintaining regenerative chloroplast photoactivity for light‐harvesting applications.
ADCYAP1R1 genotype associates with post‐traumatic stress symptoms in highly traumatized African‐American females
Authors: Almli Lynn M. , Mercer Kristina B. , Kerley Kimberly , Feng Hao , Bradley Bekh , Conneely Karen N. , Ressler Kerry J. 
Published: March 2013

AbstractPituitary adenylate cyclase‐activating polypeptide (PACAP) and its receptor (PAC1) play a critical role in biological processes that mediate stress response and have been implicated in psychological outcome following trauma. Our previous work [Ressler et al. (2011); Nature 470:492–497] demonstrated that a variant, rs2267735, in the gene encoding PAC1 (ADCYAP1R1) is associated with post‐traumatic stress disorder (PTSD) in a primarily African‐American cohort of highly traumatized females. We sought to extend and replicate our previous finding in a similarly trauma‐exposed, replicate sample of 1,160 African‐American adult male and female patients. Self‐reported psychiatric measures were collected, and DNA was obtained for genetic analysis. Using linear regression models to test for association with PTSD symptom severity under an additive (allelic) model, we found a genotype × trauma interaction in females (P < 0.001), but not males (P > 0.1); however, there was no main effect of genotype as in our previous study. The observed interaction suggests a genetic association that increases with the degree of trauma exposure in females only. This interaction remained significant in females, but not males, after controlling for age (P < 0.001), income (P < 0.01), past substance abuse (P < 0.001), depression severity (P = 0.02), or child abuse (P < 0.0005), and all five combined (P = 0.01). No significant effects of genotype (or interactions) were found when modeling depression severity when controlling for comorbid PTSD symptom severity (P > 0.1), demonstrating the relative specificity of this variant for PTSD symptoms. A meta‐analysis with the previously reported African‐American samples revealed a strong association between PTSD symptom severity and the interaction between trauma and genotype in females (N = 1424, P < 0.0001). © 2013 Wiley Periodicals, Inc.
Identification of rare copy number variants in high burden schizophrenia families
Authors: Van Den Bossche Maarten J. , Strazisar Mojca , Cammaerts Sophia , Liekens Anthony M. , Vandeweyer Geert , Depreeuw Veerle , Mattheijssens Maria , Lenaerts An‐Sofie , De Zutter Sonia , De Rijk Peter , Sabbe Bernard , Del‐Favero Jurgen 
Published: March 2013

AbstractOver the last years, genome‐wide studies consistently showed an increased burden of rare copy number variants (CNVs) in schizophrenia patients, supporting the “common disease, rare variant” hypothesis in at least a subset of patients. We hypothesize that in families with a high burden of disease, and thus probably a high genetic load influencing disease susceptibility, rare CNVs might be involved in the etiology of schizophrenia. We performed a genome‐wide CNV analysis in the index patients of eight families with multiple schizophrenia affected members, and consecutively performed a detailed family analysis for the most relevant CNVs. One index patient showed a DRD5 containing duplication. A second index patient presented with an NRXN1 containing deletion and two adjacent duplications containing MYT1L and SNTG2. Detailed analysis in the subsequent families showed segregation of the identified CNVs. With this study we show the importance of screening high burden families for rare CNVs, which will not only broaden our knowledge concerning the molecular genetic mechanisms involved in schizophrenia but also allow the use of the obtained genetic data to provide better clinical care to these families in general and to non‐symptomatic causal CNV carriers in particular. © 2013 Wiley Periodicals, Inc.
Metallocene polypropylene crystallization kinetic during cooling in rotational molding thermal condition
Authors: Sarrabi Salah , Boyer S. A. E. , Lacrampe Marie France , Krawczak P. , Tcharkhtchi Abbas 
Published: March 2013

AbstractThis article is part of an ambitious project. The aim is to simulate mechanical properties of rotomolded part from microstructure consideration. Main objective here is to consider metallocene polypropylene crystallization kinetic (PP) during cooling stage in rotational molding. Crystallization kinetic of metallocene PP is so rapid that microscopy cannot help to observe nucleation and growth. Crystallization rate can be estimated by a global kinetic. Given that cooling in rotational molding is dynamic with a constant rate, Ozawa law appears more appropriate. Ozawa parameters have been estimated by differential scanning calorimetry. In rotational molding thermal condition, Avrami index identifies a complex nucleation intermediate between spontaneous and sporadic. Ozawa rate constant is 68 times higher than this obtained for Ziegler–Natta PP. By coupling transformation rate from Ozawa model and a thermal model developed earlier, the difference between theory and experimental is less than 1%. To optimize rotational molding, study has been completed by sensitivity to adjustable parameters. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of heat‐moisture resistant epoxy resin based on phosphazene
Authors: Huang Xiaobin , Wei Wei , Wei Hao , Li Yonghua , Gu Xiaojun , Tang Xiaozhen 
Published: March 2013

AbstractAn amine‐terminated curing agent for epoxy resin based on hexachlorocyclotriphosphazene was synthesized. Its chemical structure was characterized by1H‐NMR, FT‐IR, and elemental analysis. The curing temperature was determined by differential scanning calorimeter. The thermal stability, hydrophobicity, flame retardancy, and insulation property of the epoxy resin cured by the as‐prepared curing agent were superior to those of the epoxy resin cured by 4,4′‐diaminodiphenylsulfone. The epoxy resin cured by the new curing agent obtained the best heat‐moisture resistance when the ratio of amino protons and epoxy group was 1.2 : 1. The temperature reached 318 and 376°C when the weight loss was 5 and 10% meanwhile the residue at 800°C was above 64%. The material achieved UL94 V‐0 rating and the water absorption was only 0.57%. The electric insulation property was also improved especially when it was compared in wet conditions at water absorption saturation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Characterization and gas‐permeation properties of crosslinked diacetylene‐containing polymer membranes from ferulic acid
Authors: Kanehashi Shinji , Nagasawa Toshiaki , Kobayashi Miho , Lee Sung Lin , Nakamura Masaya , Sato Shuichi , Beristain Miriam F. , Ogawa Takeshi , Miyakoshi Tetsuo , Nagai Kazukiyo 
Published: March 2013

AbstractThermally and UV crosslinked poly[propargyl(3‐methoxy‐4‐propargyloxy) cinnamate] (PPOF) were investigated in terms of their physical, thermal, optical, and gas‐permeation properties. The crosslinked membranes had high gel contents because of the formation of a diacetylene network. The wide‐angle X‐ray diffraction patterns showed that all of the membranes were amorphous in structure, regardless of the type of crosslinking reaction. The membrane density increased after the crosslinking reaction; this suggested that the free volume of the crosslinked membrane was lower than that of the untreated membranes. Drastic color changes in the membranes were also observed because of the highly conjugated crosslinked network of diacetylene. In addition, the conjugation caused by diacetylene crosslinking led to visible absorption within the range 400–600 nm. The gas permeation of the crosslinked membrane was reduced compared with that of the untreated membranes. In particular, the gas permeability of the thermally crosslinked membrane was lower than that of UV‐irradiated membrane. On the basis of this result, the degree of crosslinking by thermal treatment was higher than that of UV irradiation. Hence, the crosslinked PPOF membranes showed improved gas‐barrier properties due to the high conjugation of the crosslinked diacetylene network induced by thermal treatment and UV irradiation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of stoichiometry and cure prescription on fluid ingress in epoxy networks
Authors: Frank Katherine , Wiggins Jeffrey 
Published: March 2013

AbstractStoichiometry and cure temperature were evaluated for epoxy systems based on the diglycidyl ethers of bisphenol‐A and bisphenol‐F and cured with 3,3′‐ or 4,4′‐diaminodiphenylsulfone. The materials were formulated as stoichiometric benchmarks and with an excess of epoxide and cured in two steps (125°C/200°C) or one step (180°C). Dynamic mechanical analysis and free volume testing indicated decreased crosslink density and increased chain packing in the excess‐epoxy materials, as well as a narrowing gap in properties between 33‐ and 44‐cured networks with excess epoxy. The narrowing gap was less pronounced in materials cured at 180°C. The excess‐epoxy materials were more resistant to water ingress, exhibiting reduced equilibrium water uptake. The excess‐epoxy materials were also more resistant to methyl ethyl ketone ingress, which occurred at a slower rate in most excess‐epoxy materials. The improvement in fluid resistance was attributed to enhanced chain packing in the materials with lower crosslink densities. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Thermal processing and properties of bioplastic sheets derived from meat and bone meal
Authors: Lukubira Sam , Ogale Amod A. 
Published: March 2013

AbstractChemical modification of plasticized meat and bone meal (MBM) and its thermal processing into bioplastic sheets is reported. Specifically, MBM plasticized with 30 wt% glycerol and modified with calcium hydroxide (CH) (0, 3, 7, and 10 wt%) was batch compounded at 100°C, 15–30 min, and 60 rpm followed by thermal compaction at 140°C to produce sheets. The effect of CH content on the chemical structure, processability, and tensile properties (static and dynamic) of modified MBM sheets were studied. Fine particle size of MBM and moderate environment humidity produced well‐consolidated sheets. Increase in CH content to about 7 wt% was found to increase tensile strength and modulus, whereas the strain to failure decreased. Fourier transform infrared spectroscopy analysis of modified MBM sheets showed that the changes in mechanical properties could be attributed to increased interactions between protein chains, which were further aided by the precipitation of the fat portion of MBM. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Highly dispersed polyamide‐11/halloysite nanocomposites: Thermal, rheological, optical, dielectric, and mechanical properties
Authors: Prashantha Kalappa , Lacrampe Marie‐France , Krawczak Patricia 
Published: March 2013

AbstractBio‐based polyamide 11 and natural halloysite nanotubes (HNTs) were used for the preparation of PA‐11/HNT nanocomposites with varying nanotubes concentrations by melt extrusion using a masterbatch dilution process. The prepared nanocomposites were analyzed for microstructural changes, transparency, thermal stability, rheological behavior, dielectric, and mechanical properties. The HNT nanotubes are well dispersed in PA‐11 matrix in the studied composition range as shown by microscopy and spectrophotometry. Interestingly, good halloysite dispersion in PA‐11 matrix increases the tensile strength and Young modulus of PA‐11 without sacrificing the ductility. Highly dispersed nanotubes also bring favorable changes in the thermal stability, dielectric, and rheological characteristics of PA‐11. Additionally, glass transition temperature, crystallization temperature, and degree of crystallinity of the nanocomposites tend to increase with increase in nanotubes loading. Thus, PA‐11 can become a tailor‐made material with multifunctional characteristics, thanks to the addition of HNTs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Utilizing discarded plastic bags as matrix material for composites reinforced with chicken feathers
Authors: Yang Yiqi , Reddy Narendra 
Published: March 2013

AbstractHigh‐ density polyethylene (HDPE) in used plastic bags was reinforced with chicken feathers to develop composites in an effort to add value and reduce the amount of the plastics and feathers disposed in landfills. Feathers are biodegradable, derived from renewable resource, and are inexpensive and HDPE in plastic bags is mostly discarded in landfills. Utilizing feathers as reinforcement for HDPE composites will provide an opportunity to develop environmentally friendly composites. In this research, HDPE plastic bags were reinforced with chicken feathers and the flexural, tensile and acoustic properties were studied. It was found that incorporating feathers substantially improved the flexural properties and tensile modulus. At the optimum condition, the HDPE‐feather (50/50) composites had flexural strength of 13.9 MPa and stiffness of 0.45 N/mm compared to 9.8 MPa and 0.29 N/mm for 100% HDPE. The 50/50 HDPE‐feather composite had similar tensile strength but more than twice the tensile modulus of neat HDPE. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Physicochemical Properties and Photodynamic Activity of Novel Derivatives of Triarylmethane and Thiazine
Authors: Montes de Oca María N. , Vara Jimena , Milla Laura , Rivarola Viviana , Ortiz Cristina S. 
Published: March 2013

AbstractTriarylmethane and thiazine dyes have attracted attention as anticancer and antimicrobial agents, due to their structural features and selective localizations. Although these dyes have been initially explored in the context of photodynamic therapy, some of these such as New Fuchsin and Azure B have still not been extensively investigated. For this reason, we evaluated the chemical stability, aggregation effect, and lipophilicity, as well as the photodynamic activity against LM‐2 murine mammary carcinoma cells of five new brominated dyes of triarylmethane and thiazine. These cationic compounds were obtained at high purities and unequivocally characterized by conventional techniques. The introduction of bromine atoms into the chromophoric system of New Fuchsin and Azure B dyes gave rise to a moderate bathochromic shift and increased the lipophilicity, thereby improving their photophysical and photochemical properties for biomedical applications. Moreover, the in vitro photodynamic activity demonstrated that, as the degree of bromination increased, the phototoxicity remained unchanged or decreased. The lower efficiency to inactivate cultured tumor cells may be attributed to the formation of the colorless carbinol pseudobase and aggregation effects for triarylmethane and thiazine dyes, respectively. A promising strategy to reverse the biological activity decrease observed might be the design of third‐generation photosensitizers.
Isolation and characterization of a novel oxidant‐ and surfactant‐stable extracellular alkaline protease from Exiguobacterium profundumBK‐P23
Authors: Anbu Periasamy , Hur Byung Ki , Gyun Lee Choul 
Published: March 2013

AbstractThe novel protease from Exiguobacterium profundum BK‐P23 was partially purified by ammonium sulfate precipitation and further purified Mono Q 5/50 and Superdex 200 10/300 column chromatography. The enzyme was purified 10.23‐fold with a yield of 14%. The molecular weight was estimated to be 52 kDa by SDS‐PAGE. The enzyme was most active at a pH of 8.0 and temperature of 40°C and the enzyme was stable between a pH of 7 and 10 and up to a temperature of 50°C. The enzyme activity was enhanced by CaCl2 but was slightly inhibited by CoCl2, MgSO4, and AgNO3. In addition, this enzyme was completely inhibited by phenylmethylsulfonyl fluoride, indicating that this enzyme was a serine protease. Furthermore, the alkaline protease was more stable in the presence of surfactants such as Triton X‐100, which was followed by Tween 80 and SDS. Moreover, the enzyme was highly stable in the presence of 1% oxidizing agent (H2O2). The enzyme also has significant stability (70%–80%) in a few organic solvents. Thus, the increased stability of the enzyme in the presence of oxidizing agent, surfactants, and organic solvents may find potential applications in the detergent industry and peptide synthesis in nonaqueous media.
Exploring the potential of megaprimer PCR in conjunction with orthogonal array design for mutagenesis library construction
Authors: Tang Lixia , Zheng Kai , Liu Yu , Zheng Huayu , Wang Hu , Song Chunlei , Zhou Hong 
Published: March 2013

AbstractAlthough megaprimer PCR mutagenesis has been used routinely in protein directed evolution, users sometimes encounter technical hurdles, particularly inefficiency during amplification when large fragments are used or the template is difficult to be amplified. Instead of methodology development, here we simply overcome the limitation by optimizing megaprimer PCR conditions via orthogonal array design of the four PCR components in three levels of each: template, primer, Mg2+, and dNTPs. For this, only nine PCRs need to be performed. The strategy (termed as OptiMega) was not only successfully applied for the construction of one multiple‐site saturation mutagenesis library of halohydrin dehalogenase HheC, which failed to be constructed previously using the standard QuikChange™ protocol, but also expanded the construction of two high‐quality random mutagenesis libraries of HheA and HheC. Most importantly, OptiMega offers a quick and simple way of constructing random mutagenesis libraries by eliminating the ligation step. Our results demonstrated that the OptiMega strategy could greatly strengthen the potential of megaprimer PCR mutagenesis for library construction.
Covalent immobilization of xylanase produced from Bacillus pumilusSV‐85S on electrospun polymethyl methacrylate nanofiber membrane
Authors: Kumar Pankaj , Gupta Ashish , Dhakate Sanjay R. , Mathur Rakesh B. , Nagar Sushil , Gupta Vijay K. 
Published: March 2013

AbstractPolymethyl methacrylate (PMMA) nanofiber membrane (NFM) was synthesized by an electrospinning technique. These membranes were utilized as a support for immobilization of xylanase enzyme to study its pH stability, thermal stability, and reusability. The morphology of aligned NFM was studied by optical microscopy and scanning electron microscopy. The PMMA NFM was functionalized with phenylenediamine and activated with glutaraldehyde to yield an aldehyde group on its surface for covalent immobilization of xylanase. The Fourier transform infrared analysis of the covalently immobilized xylanase confirmed that the enzyme was immobilized on PMMA NFM via amide linkages. The immobilization efficiency of covalently bound xylanase was found experimentally to be 90%. A forward shift in pH optima from 6.0–7.0 (soluble enzyme) to 7.0–9.0 (immobilized enzyme) was observed after xylanase immobilization. The pH and temperature stability of xylanase were enhanced upon its covalent immobilization. The immobilized enzyme was active on repeated use and retained ∼80% of its initial activity after 11 reaction cycles. The improved thermal and operational stability of the covalently immobilized enzyme on PMMA NFM might be advantageous for industrial applications.
A Review of Developmental and Reproductive Toxicity of CS2and H2S Generated by the Pesticide Sodium Tetrathiocarbonate
Authors: Silva Marilyn 
Published: March 2013

BACKGROUNDSodium tetrathiocarbonate (STTC) is an example of a pesticide that when prepared for use in aqueous solution releases two toxic products carbon disulfide (CS2) (active ingredient) and hydrogen sulfide (H2S) in ambient air in equimolar concentrations resulting in potential exposure to workers and bystanders. CS2and H2S are pollutants that are generated from several pesticides as well as in industrial settings.METHODSRegistrant submitted reports and open literature studies for STTC, CS2and H2S were reviewed. Previous reports suggest that CS2was a concern as a developmental and reproductive toxicant. H2S was also examined since it is a neurotoxicant and potentially harmful to developing fetuses.RESULTSSTTC did not induce developmental or reproductive effects in animal studies. CS2was a developmental neurobehavioral toxin in rat pups (inhalation no observed effect level [NOEL] = 0.01ppm). Reproductive effects occurred in male and female factory workers after CS2exposure (NOEL = 1ppm). H2S had developmental effects in rats at doses at or above those observed for nasal pathology (NOEL = 10ppm) but was not a reproductive or developmental toxin in humans.CONCLUSIONSThe database for CS2indicates a strong potential for developmental neurotoxicity in animals at low doses but it is lacking in acceptable, well‐performed studies. There is also a lack of studies performed with CS2and H2S as a mixture.