bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinematics of the western Caribbean: Collision of the Cocos Ridge and upper plate deformation
Authors: Kobayashi Daisuke , LaFemina Peter , Geirsson Halldór , Chichaco Eric , Abrego Antonio A. , Mora Hector , Camacho Eduardo 
Published: April 2014

AbstractSubduction of the Cocos plate and collision of the Cocos Ridge have profound effects on the kinematics of the western Caribbean, including crustal shortening, segmentation of the overriding plate, and tectonic escape of the Central American fore arc (CAFA). Tectonic models of the Panama Region (PR) have ranged from a rigid block to a deforming plate boundary zone. Recent expansion of GPS networks in Panama, Costa Rica, and Colombia makes it possible to constrain the kinematics of the PR. We present an improved kinematic block model for the western Caribbean, using this improved GPS network to test a suite of tectonic models describing the kinematics of this region. The best fit model predicts an Euler vector for the counterclockwise rotation of the CAFA relative to the Caribbean plate at 89.10°W, 7.74°N, 1.193° Ma−1, which is expressed as northwest‐directed relative block rates of 11.3 ± 1.0–16.5 ± 1.1 mm a−1 from northern Costa Rica to Guatemala. This model also predicts high coupling along the Nicoya and Osa segments of the Middle American subduction zone. Our models demonstrate that the PR acts as a single tectonic block, the Panama block, with a predicted Euler vector of 107.65°W, 26.50°N, 0.133° Ma−1. This rotation manifests as northeast migration of the Panama block at rates of 6.9 ± 4.0–7.8 ± 4.8 mm a−1 from southern Costa Rica to eastern Panama. We interpret this motion as tectonic escape from Cocos Ridge collision, redirected by collision with the North Andes block, which migrates to the northwest at 12.2 ± 1.2 mm a−1.
Understanding the effects of nanocarbons on flexible polymer chain orientation and crystallization: Polyethylene/carbon nanochip hybrid fibrillar crystal growth
Authors: Green Emily C. , Zhang Yiying , Minus Marilyn L. 
Published: April 2014

ABSTRACTPolyethylene (PE)/carbon nanochip fibers (CNCF) fibrillar crystals were grown under shear flow. The fibrillar crystals ranged from 25 to 200 nm in diameter and bundled to form PE/CNCF macro‐fibers. The PE/CNCF fibers were further processed by hot‐drawing near the PE melting temperature. On the basis of small‐angle X‐ray analysis, it was found that during drawing the presence of CNCF led to continuous extended‐chain PE crystal growth. DSC melting peaks associated with transformation of the orthorhombic to a hexagonal lattice phase in the PE crystal structure (i.e., increased ordering and extension of the polymer chain along the fiber axis) was also observed for drawn hybrid PE/CNCF fibrillar crystals. The orientation factor for the extended‐chain (i.e., shish) crystals in the hybrid as compared to the control fibers improved from 0.88 to 0.93. This work shows the direct evidence that these nanocarbon fillers can promote extended‐chain polymer crystal growth under shear. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40763.
Complex of cisplatin with biocompatible poly(ethylene glycol) with pendant carboxyl groups for the effective treatment of liver cancer
Authors: Li Jing , Hu Xiuli , Liu Ming , Hou Jie , Xie Zhigang , Huang Yubin , Jing Xiabin 
Published: April 2014

ABSTRACTCisplatin was incorporated into polymeric carriers through the coordination of Pt with the carboxylic groups of methoxy‐poly(ethylene glycol) (mPEG)‐block‐poly[(2‐carboxy‐ethylsulfanyl)‐propyl glycidyl ether] (PCPGE). The mPEG‐b‐PCPGE/Pt complexes with a Pt content of 14 wt % could self‐assemble into spheric micelles with diameter of about 80 nm in aqueous solution. The effective internalization of the polymer platinum micelles by the cells via an endocytosis mechanism was confirmed by confocal laser scanning microscopy and flow cytometry. The antitumor activity of the polymeric micelles was similar to that of cisplatin in vitro. The in vivo blood clearance of platinum was studied, and the results show that the micelles exhibited longer blood circulation than the free cisplatin. The biodistribution of cisplatin and its micelles in mice was studied through the measurement of the Pt content in plasma, organs, and tumors, especially in tumor cell DNA. Their antitumor activity in vivo, assessed in mice bearing H22 liver cancers, showed that the micelles exhibited greater antitumor efficacy than free cisplatin. Therefore, this polymer platinum micelle is a promising candidate as a smart antitumor drug carrier for malignancy therapy in future clinical applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40764.
Influence of microwave heating time on the structure and properties of chitosan films
Authors: Jacquot Charlotte , Jacquot Muriel , Marques Patrícia , Jasniewski Jordane , Akhtar Muhammad Javeed , Didelot Anne‐Sophie , Desobry Stéphane 
Published: April 2014

ABSTRACTThe aim of this study was to investigate chitosan film behavior during microwave heating for 10 different heating times from 0 to 40 min. Chitosan films were produced by casting. Their structure and properties were investigated with several techniques, including Fourier transform infrared spectroscopy and differential scanning calorimetry, but also by the measurement of the film color and the mechanical properties or by the study of the rheological properties of the rehydrated films. An original technique of gas chromatography (electronic nose) was used to analyze the film odor and highlight the presence of volatile compounds related to the Maillard reaction occurring during film heating. The results show that structural modifications occurred in two steps; this affected the polymer structure, such as the crystallization and chain scission. The appearance of the neoformed compounds was also observed and must be controlled to guarantee the safety of this food‐contact packaging material. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40779.
Temperature‐triggered disintegrable poly(N‐isopropylacrylamide) nanoparticles via heterophase polymerization in the presence of tetramethylethylenediamine and sodium dodecyl sulfate
Authors: Chen Yan , Sajjadi Shahriar 
Published: April 2014

ABSTRACTIn this work, polymerization of N‐isopropylacrylamide (NIPAM) in the presence of N,N,N′,N′‐tetramethylethylenediamine (TEMED) and sodium dodecyl sulfate (SDS) has been studied. The ability to control the characteristics of resulting particles was investigated via varying the concentrations of monomer, SDS, and TEMED used in the polymerization. Particles formed in the absence of TEMED were not completely soluble in water below lower critical solution temperature (LCST) but were quite stable. With the help of TEMED, fully disintegrable particles in water below LCST could be produced but at the cost of low stability. Electrophoretic measurements showed a substantial decrease in zeta potential of resulting colloids due to many neutral radicals generated by TEMED. With the aid of a small amount of SDS, stable temperature‐triggered water‐disintegrable polyNIPAM particles as small as 70 nm could be obtained. However, excessive use of SDS caused the particles to swell in the course of reaction and therefore adversely affected particles size and properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40781.
Structure and mechanical properties of blends of an amorphous polyamide and an amorphous copolyester
Authors: Granado Ainhoa , Iturriza Lara , Eguiazábal Jose Ignacio 
Published: April 2014

ABSTRACTThis article deals with the structure and mechanical properties of blends of an amorphous copolyester (PCTG) and an amorphous polyamide (aPA) which were directly prepared during the plasticization step of an injection molding process. The blends were composed by an almost pure aPA phase, and a PCTG‐rich phase where some aPA subparticles are present. The morphology of the blends showed both rather fine dispersed particles and occasionally large particles with occluded subparticles. This complex morphology indicated a low interface tension attributed to the presence of some aPA in the PCTG‐rich phase of the blends. The almost linear behavior of the modulus of elasticity was attributed to the constancy of the main structural characteristics upon blending and the equally linear ductility to the good adhesion level and the presence of thin and elongated morphologies. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40785.
A facile method of using sulfobetaine‐containing copolymers for biofouling resistance
Authors: Liu Qingsheng , Li Wenchen , Wang Hua , Liu Lingyun 
Published: April 2014

ABSTRACTAntifouling materials are desirable for many biomedical applications. In this work, the poly(sulfobetaine methacrylate‐co‐butyl methacrylate) (PSB) copolymers were investigated for their antifouling properties. The copolymers were synthesized via a simple free‐radical polymerization with feed ratio of the zwitterionic sulfobetaine methacrylate (SBMA) varying from 0 to 20 mol %. The polymer composition was verified by nuclear magnetic resonance. The enzyme‐linked immunosorbent assay and surface plasmon resonance were used to evaluate protein adsorption on a series of PSB copolymers from the single protein solution of fibrinogen, undiluted human blood serum, and undiluted human blood plasma. Results show that the protein adsorption amount decreased with the increasing content of SBMA in the copolymers. The adsorption levels achieved by PSB containing 20 mol % SBMA (PSB20) were only 4, 17, and 15 ng/cm2 from fibrinogen, serum, and plasma, respectively, which represented 99%, 90%, and 90% reduction compared with the adsorption amounts on poly(butyl methacrylate) with no SBMA. The PSB20 film also completely inhibited endothelial cell attachment. Fouling resistance of PSB polymers can be well correlated with their receding water contact angles, which represent the polymer surface compositions in aqueous environment. The excellent antifouling abilities of PSB copolymers, combined with the facial synthesis method, commercial availability of all monomers, and low cost, render them highly promising for wide practical applications. The polymers can be applied versatilely as both solvent‐cast films and surface coatings. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40789.
Viscosity changes of aqueous carboxymethyl starch by partial crosslinking and montmorillonite addition
Authors: Zdanowicz Magdalena , Spychaj Tadeusz 
Published: April 2014

ABSTRACTSlightly crosslinked carboxymethyl starch (cCMS) with degree of substitution (DS) 0.8–0.9 was prepared using mono‐ and di‐chloroacetic acids (MCA and DCA, respectively). Constant molar ratio of halogenated acetic acid derivatives to anhydroglucosidic unit (AGU) was adjusted (MCA+DCA):AGU=1.75:1; whereas, DCA:AGU ratio was changed in a range 0–0.10:1. The viscosity of 2 wt % cCMS aqueous solutions increased substantially for very slightly crosslinked product (DCA:AGU molar ratio 0.0075), in comparison to unmodified CMS, up to 170,000 mPa·s at 1 rpm, and 16,000 mPa·s, respectively. Some viscosity decrease of cCMS solutions during storing was observed. The explanation of this phenomenon was discussed and supported by 1H NMR results. The rheological properties of cCMS solutions as well as aqueous cCMS/clay dispersions with various type of montmorillonite (MMT): sodium, calcium and organophilized as shear‐thinning systems were evaluated on a basis of power law model. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40793.
Selective etching of polylactic acid in poly(styrene)‐block‐poly(d,l)lactide diblock copolymer for nanoscale patterning
Authors: Cummins Cian , Mokarian‐Tabari Parvaneh , Holmes Justin D. , Morris Michael A. 
Published: April 2014

ABSTRACTSelf‐assembled thin films of a lamellar forming polystyrene‐block‐poly(d,l)lactide (PS‐b‐PLA) block copolymer (BCP) contain a “reactive” block that can be readily removed to provide a template for substrate pattern formation. Various methods of PLA removal were studied here with a view to develop the system as an on‐chip etch mask for substrate patterning. Solvo‐microwave annealing was used to induce microphase separation in PS‐b‐PLA BCP with a periodicity of 34 nm (Lo) on silicon and silicon on insulator (SOI) substrates. Wet etches based on alkaline and enzymatic solutions were studied in depth. Fourier transform‐infrared (FT‐IR) analysis showed that basic hydrolysis using sodium hydroxide (NaOH) or ammonium hydroxide (NH4OH) solutions resulted in greater PLA removal in comparison to an enzymatic approach using Proteinase K in a Tris‐HCl buffer solution. However, in the enzymatic approach, the characteristic self‐assembled fingerprint patterns were retained with less damage. Comparison to a dry etch procedure using a reactive ion etch (RIE) technique was made. A detailed study of the etch rate of PS and PLA homopolymer and PS‐b‐PLA shows depending on DC bias, the etch selectivity of PLA and PS
can be almost doubled from 1.7 at DC bias 145 V to 3 at DC bias 270 V. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40798.Together with Krebs et al., J. Appl. Polym. Sci. (2014) 131, 40795, doi:10.1002/app.40795, this article is part of a Special Issue on Polymers for Microelectronics. The remaining articles appear in J. Appl. Polym. Sci. (2014) volume 131, issue 24. This note was added on 1st July 2014.
Efficient expression of a soluble lipid transfer protein (LTP) of Platanus orientalis using short peptide tags and structural comparison with the natural form
Authors: Salari Farhad , Vahedi Fatemeh , Chamani Jamshidkhan , Varasteh Abdolreza , Ketabdar Hanieh , Sankian Mojtaba 
Published: April 2014

AbstractSuccessful recombinant allergen‐based immunotherapy has drawn a great deal of attention to use recombinant allergens for new therapeutic and/or diagnostic strategies. The Escherichia coli expression system is frequently used to produce recombinant allergens; however, protein expression in E. coli often results in inclusion bodies. Here, we focused on the expression of two recombinant soluble forms of Pla or 3 using solubility‐enhancing peptide tags, human immune deficiency virus type 1 transactivator of transcription core domain and poly‐arginine–lysine: rTAT–Pla or 3 and rPoly‐Arg–Lys–Pla or 3. Structural characteristics and IgE reactivity of purified recombinant proteins were compared with natural Pla or 3 (nPla or 3) isolated from Platanus orientalis using circular dichroism spectra, fluorescence spectroscopy, and immunoblotting. Likewise, intrinsic viscosity and Stokes radius of the natural and recombinant Pla or 3 allergens were determined to analyze structural compactness in aqueous media. The results indicate high‐level solubility and efficient expression of the fusion proteins (rTAT–Pla or 3 and rPoly‐Arg–Lys–Pla or 3) compared with the wild‐type recombinant. Furthermore, the similar structural characteristics and IgE‐binding activities of the fusion proteins to nPla or 3 provide a promising tool for allergy diagnosis and treatment.
De novo 2q36.1q36.3 interstitial deletion involving the PAX3 and EPHA4 genes in a fetus with spina bifida and cleft palate
Authors: Goumy Carole , Gay‐Bellile Mathilde , Eymard‐Pierre Eléonore , Kemeny Stephan , Gouas Laetitia , Déchelotte Pierre , Gallot Denis , Véronèse Lauren , Tchirkov Andrei , Pebrel‐Richard Céline , Vago Philippe 
Published: April 2014

BackgroundInterstitial 2q36 deletion is a rare event. Only two previously published cases of 2q36 deletions were characterized using array‐CGH. This is the first case diagnosed prenatally.MethodsWe report on the prenatal diagnosis of a 2q36.1q36.3 interstitial deletion in a fetus with facial dysmorphism, spina bifida, and cleft palate.ResultsArray‐CGH analysis revealed a 5.6 Mb interstitial deletion of the long arm of chromosome 2q36.1q36.3, including the PAX3 and EPHA4 genes.ConclusionThe present study reinforces the hypothesis that PAX3 haploinsufficiency may be associated with neural tube defects in humans and suggests that the EPHA4 gene might be implicated during palate development. This report also illustrates the added value of array‐CGH to detect cryptic chromosomal imbalances in malformed fetuses and to improve genetic counseling prenatally. Birth Defects Research (Part A) 100:507–511, 2014. © 2014 Wiley Periodicals, Inc.
An investigation of the role of the adiponectin variable domain on the stability of the collagen‐like domain
Authors: Harris Paul W. R. , Hampe Lutz , Radjainia Mazdak , Brimble Margaret A. , Mitra Alok K. 
Published: April 2014

ABSTRACTThe chemical synthesis is described of a polypeptide construct possessing both the variable and the collagen‐like domain of adiponectin, which can be used as a model system for probing the influence of the variable domain on multimerization of this important circulating hormone. Using a collagen domain repeat peptide unit derived from native adiponectin or a glutamic acid analogue was ineffective due to noncollagenous conformational properties in both cases. However, employing a collagen model peptide and linking this to the variable domain thioester peptide using native chemical ligation proved effective. The 63 residue peptide was characterized by circular dichroism and mass spectrometry which demonstrated that a collagen‐like triple‐helical structure was preserved. © 2014 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 313–321, 2014.
Engineering of chromosomal wax ester synthase integrated Saccharomyces cerevisiae mutants for improved biosynthesis of fatty acid ethyl esters
Authors: Shi Shuobo , Valle‐Rodríguez Juan Octavio , Siewers Verena , Nielsen Jens 
Published: April 2014

ABSTRACTIn recent years, significant advances have been made to engineer robust microbes for overproducing biochemical products from renewable resources. These accomplishments have to a large extend been based on plasmid based methods. However, plasmid maintenance may cause a metabolic burden on the host cell and plasmid‐based overexpression of genes can result in genetically unstable strains, which contributes to loss in productivity. Here, a chromosome engineering method based on delta integration was applied in Saccharomyces cerevisiae for the production of fatty acid ethyl esters (FAEEs), which can be directly used as biodiesel and would be a possible substitute for conventional petroleum‐based diesel. An integration construct was designed and integrated into chromosomal delta sequences by repetitive transformation, which resulted in 1–6 copies of the integration construct per genome. The corresponding FAEE production increased up to 34 mg/L, which is an about sixfold increase compared to the equivalent plasmid‐based producer. The integrated cassette in the yeast genome was stably maintained in nonselective medium after deletion of RAD52 which is essential for efficient homologous recombination. To obtain a further increase of FAEE production, genes encoding endogenous acyl‐CoA binding protein (ACB1) and a bacterial NADP+‐dependent glyceraldehyde‐3‐phosphate dehydrogenase (gapN) were overexpressed in the final integration strain, which resulted in another 40% percent increase in FAEE production. Our integration strategy enables easy engineering of strains with adjustable gene copy numbers integrated into the genome and this allows for an easy evaluation of the effect of the gene copy number on pathway flux. It therefore represents a valuable tool for introducing and expressing a heterologous pathway in yeast. Biotechnol. Bioeng. 2014;111: 1740–1747. © 2014 Wiley Periodicals, Inc.
Biotechnological production of plant‐specific hydroxylated phenylpropanoids
Authors: Lin Yuheng , Yan Yajun 
Published: April 2014

ABSTRACTHydroxylated phenylpropanoid compounds (e.g., esculetin, piceatannol, and eriodictyol) have been proved to possess important biological activities and pharmacological properties. These compounds exist at low abundance in nature, which hampers their cost‐effective isolation, and broad application. Meanwhile, regiospecific hydroxylation of complex aromatic compounds is still quite challenging for chemical synthesis. In past decades, biocatalytic hydroxylation of plant phenylpropanoids was achieved due to the identification and engineering of some cytochrome P450 hydroxylases; however, the conversion efficiency was still too low for scale‐up production use. In this work, we identify a non‐P450 monooxygenase (HpaBC) from Escherichia coli, which is able to catalyze the efficient ortho‐hydroxylation towards plant phenylpropanoids umbelliferone and resveratrol; meanwhile it also exhibits activity towards naringenin. On this basis, whole‐cell biocatalysis enables the production of esculetin and piceatannol at high titers (2.7 and 1.2 g/L, respectively, in shake flasks) and high yields (close to 100%). To our knowledge, this work reports the highest titers and yields for biotechnological production of esculetin and piceatannol, representing a promising hydroxylation platform. Biotechnol. Bioeng. 2014;111: 1895–1899. © 2014 Wiley Periodicals, Inc.
Inferring alterations in cell‐to‐cell communication in HER2+ breast cancer using secretome profiling of three cell models
Authors: Klinke David J. , Kulkarni Yogesh M. , Wu Yueting , Byrne‐Hoffman Christina 
Published: April 2014

ABSTRACTChallenges in demonstrating durable clinical responses to molecular‐targeted therapies have sparked a re‐emergence in viewing cancer as an evolutionary process. In somatic evolution, cellular variants are introduced through a random process of somatic mutation and are selected for improved fitness through a competition for survival. In contrast to Darwinian evolution, cellular variants that are retained may directly alter the fitness competition. If cell‐to‐cell communication is important for selection, the biochemical cues secreted by malignant cells that emerge should be altered to bias this fitness competition. To test this hypothesis, we compared the proteins secreted in vitro by two human HER2+ breast cancer cell lines (BT474 and SKBR3) relative to a normal human mammary epithelial cell line (184A1) using a proteomics workflow that leveraged two‐dimensional gel electrophoresis (2DE) and MALDI‐TOF mass spectrometry. Supported by the 2DE secretome maps and identified proteins, the two breast cancer cell lines exhibited secretome profiles that were similar to each other and, yet, were distinct from the 184A1 secretome. Using protein–protein interaction and pathway inference tools for functional annotation, the results suggest that all three cell lines secrete exosomes, as confirmed by scanning electron microscopy. Interestingly, the HER2+ breast cancer cell line exosomes are enriched in proteins involved in antigen‐processing and presentation and glycolytic metabolism. These pathways are associated with two of the emerging hallmarks of cancer: evasion of tumor immunosurveillance and deregulating cellular energetics. Biotechnol. Bioeng. 2014;111: 1853–1863. © 2014 Wiley Periodicals, Inc.