bluuebunny/crossref_metadata_2025_split huggingface dataset:
Covalently cross‐linked and hydrophobically modified alginic acid hydrogels and their application as drug carriers
Authors: Wu Min , Ni Caihua , Yao Bolong , Zhu Changping , Huang Bo , Zhang Liping 
Published: November 2012

AbstractCovalently crosslinked and hydrophobically modified alginate hydrogels were prepared through esterification of alginic acid (ALG‐H) with 1,10‐decanediol that functioned as a crosslinking agent and hydrophobic component. The preparation was accomplished with one step and was carried out in N,N‐dimethylformamide solution at a reduced pressure for removing the water produced. The characterization results confirmed the esterification of the products. The modified alginate hydrogels could be used as drug delivery vehicles for controlled release. The drug release study revealed that compared with a calcium alginate hydrogel the modified hydrogels possessed improved loading rate and encapsulation efficiency for the hydrophobic drug(ibuprofen), and a remarkable sustained release behavior was observed. The release kinetics was close to zero order, a desirable drug release pattern. The modified alginate hydrogels were nontoxic and were potentially applicable as a promising biomaterial. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Linear and star‐shaped POSS hybrid materials containing crystalline isotactic polystyrene chains
Authors: Vielhauer Maximilian , Lutz Pierre J. , Reiter Günter , Mülhaupt Rolf 
Published: November 2012

AbstractNew crystalline nanostructured inorganic–organic hybrid materials containing isotactic polystyrene (iPS) are prepared by means of hydrosilylation coupling of vinyl‐terminated iPS with octakis(dimethylsilyloxy)silsesquioxane (Q8M8H). The number average molar mass of the iPS chains varies between 2000 and 6000 g mol−1. As a function of the iPS/Q8M8H ratio, using excess reagent, the formation of linear or star‐shaped hybrid architectures is achieved. Via fractionation, it is possible to isolate well‐defined linear hybrids containing one iPS chain and seven ethyl groups per silica core (iPS‐Q8M8E7) as well as star‐shaped hybrids containing up to eight iPS side chains (iPS6‐8‐Q8M8). These new iPS/polyhedral oligomeric silsesquioxane hybrid materials crystallize when the number average molar mass of iPS side chain exceeds 5500 g mol−1. The hydrosilylation coupling reaction and the resulting linear iPS‐Q8M8E7 and star‐shaped iPS6‐8‐Q8M8 are characterized by NMR spectroscopy, size exclusion chromatography (gel permeation chromatography), and polarized light microscopy. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Formation of a porphyrin/fullerene light‐harvesting system from self‐assembly of porphyrin‐end‐functionalized polycyclohexane and [6,6]‐phenyl‐C61‐butyric acid methyl ester: Effects of microphase separation and π–π interactions
Authors: Natori Itaru , Natori Shizue , Kanasashi Anna , Tsuchiya Kosuke , Ogino Kenji 
Published: November 2012

AbstractThin films composed of zinc tetraphenylporphyrin‐end‐functionalized polycyclohexane (ZnTPP‐PCHE) and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) blends were prepared to investigate their potential as light‐harvesting systems within polymer solar cells (PSCs). Both the microphase separation characteristics and the extent of π–π interactions in these ZnTPP‐PCHE/PCBM blends had significant effects on the optical properties of the films. The extent to which the absorption bands of the films overlapped the terrestrial solar spectrum was increased considerably when the blends formed a co‐continuous structure, even though films of pure ZnTPP‐PCHE or PCBM exhibited only weak absorption over that wavelength region. We conclude that these polymer blend films may be considered as viable candidates for light‐harvesting systems within PSCs. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Preparation and Properties of An Insensitive Booster Explosive Based on LLM‐105
Authors: Xu Wenzheng , An Chongwei , Wang Jingyu , Dong Jun , Geng Xiaoheng 
Published: November 2012

AbstractA new insensitive booster explosive based on 2,6‐diamino‐3,5‐dinitropyrazing‐1‐oxide (LLM‐105) was prepared by a solvent‐slurry process with ethylene propylene diene monomer (EPDM) as binder. SEM (scanning electron microscopy) was employed to characterize the morphology and particle size of LLM‐105 and molding powder. The mechanical sensitivity, thermal sensitivity, shock wave sensitivity, and detonation velocity of the LLM‐105/EPDM booster were also measured and analyzed. The results show that both mechanical sensitivity and thermal sensitivity of LLM‐105/EPDM are much lower than that of conventional boosters, such as PBXN‐5 and A5. Its shock wave sensitivity is also lower than that of PBXN‐5 and PBXN‐7. When the density of charge is 95 % TMD, its theoretical and measured detonation velocities are 7858 m s−1 and 7640 m s−1, respectively. These combined properties suggested that LLM‐105/EPDM can be used as an insensitive booster.
Study on the Compatibility of Tetraethylammonium Decahydrodecaborate (BHN) with some Energetic Components and Inert Materials
Authors: Pang Weiqiang , Fan Xuezhong , Xue Yunna , Xu Huixiang , Zhang Wei , Zhang Xiaohong , Li Yonghong , Li Yang , Shi Xiaobing 
Published: November 2012

AbstractThe compatibility of tetraethylammonium decahydrodecaborate (BHN) with some energetic components and inert materials of solid propellants was studied by DSC method, where glycidyl azide polymer (GAP), cyclotrimethylenetrinitramine (RDX), cyclotetramethylenetetranitroamine (HMX), lead 3‐nitro‐1,2,4‐triazol‐5‐onate (NTO‐Pb), hexanitrohexaazaisowurtzitane (CL‐20), 3,4‐dinitrofurzanfuroxan (DNTF), N‐guanylurea‐dinitramide (GUDN), aluminum powder (Al, particle size=12.18 μm) and magnesium powder (Mg, particle size: 44–74 μm) were used as energetic components and polyoxytetramethylene‐co‐oxyethylene (PET), polyethylene glycol (PEG), addition product of hexamethylene diisocyanate and water (N‐100), hydroxyl terminated polybutadiene (HTPB), cupric adipate (AD‐Cu), cupric 2,4‐dihydroxy‐benzoate (β‐Cu), lead phthalate (ϕ‐Pb), carbon black (C. B.), aluminum oxide (Al2O3), 1,3‐dimethyl‐1,3‐diphenyl urea (C2), di‐2‐ethylhexyl sebacate (DOS) and potassium perchlorate (KP), were used as inert materials. It was concluded that the binary systems of BHN with NTO‐Pb, CL‐20, aluminum powder, magnesium powder, PET, PEG, N‐100, AD‐Cu, β‐Cu, ϕ‐Pb, C. B., Al2O3, C2, DOS, and KP are compatible, and systems of BHN with GAP and HMX are slightly sensitive, and with RDX, DNTF, and GUDN are incompatible. The impact and friction sensitivity data of BHN and BHN in combination with the energetic materials under present study were obtained, and there was no consequential affiliation between sensitivity and compatibility.
Isocyanate‐Free and Dual Curing of Smokeless Composite Rocket Propellants
Authors: Landsem Eva , Jensen Tomas L. , Kristensen Tor E. , Hansen Finn K. , Benneche Tore , Unneberg Erik 
Published: November 2012

AbstractTraditional composite rocket propellants are cured by treatment of hydroxyl‐terminated prepolymers with polyfunctional aliphatic isocyanates. For development of smokeless composite propellants containing nitramines and/or ammonium dinitramide (ADN), energetic binder systems using glycidyl azide polymer (GAP) are of particular interest. Polyfunctional alkynes are potential isocyanate‐free curing agents for GAP through thermal azide‐alkyne cycloaddition and subsequent formation of triazole crosslinkages. Propargyl succinate or closely related aliphatic derivatives have previously been reported for such isocyanate‐free curing of GAP. Herein, we present the synthesis and use of a new aromatic alkyne curing agent, the crystalline solid bisphenol A bis(propargyl ether) (BABE), as isocyanate‐free curing agent in smokeless propellants based on GAP, using either octogen (HMX) and/or prilled ADN as energetic filler materials. Thermal and mechanical properties, impact and friction sensitivity and ballistic characteristics were evaluated for these alkyne cured propellants. Improved mechanical properties could be obtained by combining isocyanate and alkyne curing agents (dual curing), a combination that imparted better mechanical properties in the cured propellants than either curing system did individually. The addition of a neutral polymeric bonding agent (NPBA) for improvement of binder‐filler interactions was also investigated using tensile testing and dynamic mechanical analysis (DMA). It was verified that the presence of isocyanates is essential for the NPBA to improve the mechanical properties of the propellants, further strengthening the attractiveness of dual cure systems.
Thermal Analysis of Magnesium/Perfluoropolyether Pyrolants
Authors: Rider Keith B. , Little Brian K. , Emery Samuel B. , Lindsay C. Michael 
Published: November 2012

AbstractExothermic reactions between metals and fluorinated polymers are found in a variety of energetic materials, including reactive binder systems and the Magnesium‐Teflon‐Viton incendiary composition. This paper describes the reactions between a high molecular weight perfluoropolyether, Fomblin Y 140/13, and magnesium in a variety of morphologies including μm‐scale powders and nano‐scale layered films. Using Temperature Programmed Desorption and Temperature Programmed Reaction we have found that the magnesium‐perfluoropolyether interaction is characterized by: (1) competition between Fomblin decomposition and desorption, and (2) magnesium passivation by the formation of magnesium fluoride. Differential Scanning Calorimetry measurements establish a lower‐bound estimate of the specific reaction energy of 9.2 kJ g−1. High molecular weight Fomblin (6500 amu) undergoes a competitive reaction/desorption process with desorption occurring at 550 K and decomposition at 610 K. Decomposition becomes more favorable relative to desorption for higher heating rates and thicker films. Perfluoropolyethers produce several characteristic ions in the 70 eV election ionization mass spectra, with the CF3+ ion being the most abundant ion observed during both the molecular desorption and decomposition. Larger fragment ions with masses of 235 and 285 amu are observed in relatively high concentrations during desorption and low concentrations during decomposition. The reaction between magnesium and Fomblin begins at 400 K, producing CF3+, CO+, and C2F5+ in the electron ionization mass spectrum. We propose that these reactions form a passivating layer of magnesium fluoride that protects the remaining metal as it approaches the magnesium melting point. Most of the reaction takes place at 800 K and above when the magnesium fluoride film ruptures.
Identity‐based optimistic fair exchange in the standard model
Authors: Zhang Lei , Wu Qianhong , Qin Bo 
Published: November 2012

ABSTRACTA fair exchange protocol allows two entities to exchange digital signatures over open networks in a fair way, so that either each entity obtains the other's signature or neither entity does. Fair exchange protocol plays an important role in electronic commerce in the case of exchanging digital contracts. In this paper, we propose a fair exchange protocol based on identity‐based verifiably encrypted signatures. Our protocol involves an offline trusted third party which is only required when one entity attempts to cheat or crashes. The underlining identity‐based verifiably encrypted signature scheme is proven secure under the computational Diffie–Hellman assumption and is the first identity‐based verifiably encrypted signature scheme provably secure against existential unforgeable under adaptive chosen message and identity attacks in the standard model. Copyright © 2012 John Wiley & Sons, Ltd.
Evolution styles: using architectural knowledge as an evolution driver
Authors: Cuesta Carlos E. , Navarro Elena , Perry Dewayne E. , Roda Cristina 
Published: November 2012

AbstractSoftware evolution is an increasingly challenging and compelling concern for every developed software system because of the changes in the requirements, the technology, etc. When software evolution is carried out, software architecture emerges as one of the cornerstones that should be considered from two different points of view: as an artifact for the evolution, as it helps the architect plan and restructure the system, and as an artifact of the evolution, because it has to be modified as well. This paper focuses on the second point of view—that is, on the evolution of the software architecture, but taking into account architectural knowledge as a key driver of the process. Given that architecture rationale and design intent are critical in evolving software systems, it is imperative that they be captured in some useful form to aid that evolution process. We present a new approach for evolution styles that extends them by considering in their description the architectural knowledge as a valuable asset of the evolution process. Copyright © 2012 John Wiley & Sons, Ltd.
Minocycline promotes axonal regeneration through suppression of RGMa in rat MCAO/reperfusion model
Authors: Tao Tao , Xu Guanghui , Si Chen Cindy , Feng Jinzhou , Kong Yuhan , Qin Xinyue 
Published: November 2012

AbstractMinocycline has been recently implicated in protection against focal cerebral ischemia reperfusion (I/R), but the protective effects on neurobehavioral abnormalities remains contradictory. In the present study, we investigate whether minocycline improves axonal regeneration and neurological function recovery by inhibiting the expression of the repulsive guidance molecular A (RGMa) after focal cerebral ischemia reperfusion. Male Sprague‐Dawley (SD) rats were subjected to occlusion of the right middle cerebral artery (MCAO) for 2 h and 3 mg kg−1 minocycline was injected intravenously immediately after reperfusion twice a day for 14 days. The staircase test and modified neurological severity score (mNSS) were performed to evaluate functional outcome and blood‐brain barrier (BBB) permeability was assessed by Evan's blue dye extravasation (EB) at the expected time point. The expression of RGMa in ischemic cortex was measured by immunohistochemical staining and Western blot 2 weeks after MCAO. Neurofilament protein 200 (NF‐200) immunohistochemical staining was used to assess axonal damage. Treatment with minocycline at a dose of 3 mg kg−1 via the caudal vein significantly reduced the extravasation of EB, elevated mNSS and improved forelimb motor function as assessed by the staircase test when compared to the I/R group (P < 0.05). Moreover, axonal regrowth was enhanced in the minocycline treatment group when compared to the I/R group (P < 0.05). In addition, minocycline significantly reduced the expression of RGMa protein 2 weeks after MCAO as assessed by both immunostaining and Western blot. Our studies suggest that early minocycline treatment promotes neurological functional recovery and axonal regeneration in rats after MCAO, which might be mediated by down‐regulating RGMa expression. Synapse, 2013. © 2012 Wiley Periodicals, Inc.
Birth defects associated with perturbations in preimplantation, gastrulation, and axis extension: from conjoined twinning to caudal dysgenesis
Authors: Ferrer‐Vaquer Anna , Hadjantonakis Anna‐Katerina 
Published: November 2012

AbstractCongenital malformations represent approximately 3 in 100 live births within the human population. Understanding their pathogenesis and ultimately formulating effective treatments are underpinned by knowledge of the events and factors that regulate normal embryonic development. Studies in model organisms, primarily in the mouse, the most prominent genetically tractable mammalian model, have equipped us with a rudimentary understanding of mammalian development from early lineage commitment to morphogenetic processes. In this way, information provided by studies in the mouse can, in some cases, be used to draw parallels with other mammals, including human. Here, we provide an overview of our current understanding of the general sequence of developmental events from early cell cleavages to gastrulation and axis extension occurring in human embryos. We will also review some of the rare birth defects occurring at these stages, in particular those resulting in conjoined twinning or caudal dysgenesis. WIREs Dev Biol 2012, 2:427–442. doi: 10.1002/wdev.97This article is categorized under:

Establishment of Spatial and Temporal Patterns > Cell Sorting and Boundary Formation
Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing
Signaling Pathways > Cell Fate Signaling
Birth Defects > Associated with Preimplantation and Gastrulation
Systems analysis of biological networks in skeletal muscle function
Authors: Smith Lucas R. , Meyer Gretchen , Lieber Richard L. 
Published: November 2012

AbstractSkeletal muscle function depends on the efficient coordination among subcellular systems. These systems are composed of proteins encoded by a subset of genes, all of which are tightly regulated. In the cases where regulation is altered because of disease or injury, dysfunction occurs. To enable objective analysis of muscle gene expression profiles, we have defined nine biological networks whose coordination is critical to muscle function. We begin by describing the expression of proteins necessary for optimal neuromuscular junction function that results in the muscle cell action potential. That action potential is transmitted to proteins involved in excitation–contraction coupling enabling Ca2+ release. Ca2+ then activates contractile proteins supporting actin and myosin cross‐bridge cycling. Force generated by cross‐bridges is transmitted via cytoskeletal proteins through the sarcolemma and out to critical proteins that support the muscle extracellular matrix. Muscle contraction is fueled through many proteins that regulate energy metabolism. Inflammation is a common response to injury that can result in alteration of many pathways within muscle. Muscle also has multiple pathways that regulate size through atrophy or hypertrophy. Finally, the isoforms associated with fast muscle fibers and their corresponding isoforms in slow muscle fibers are delineated. These nine networks represent important biological systems that affect skeletal muscle function. Combining high‐throughput systems analysis with advanced networking software will allow researchers to use these networks to objectively study skeletal muscle systems. WIREs Syst Biol Med 2013, 5:55–71. doi: 10.1002/wsbm.1197This article is categorized under:

Models of Systems Properties and Processes > Mechanistic Models
Physiology > Mammalian Physiology in Health and Disease
Laboratory Methods and Technologies > RNA Methods
Pharmacogenomics discovery and implementation in genome‐wide association studies era
Authors: Ni Xiuqin , Zhang Wei , Huang R. Stephanie 
Published: November 2012

AbstractClinical response to therapeutic treatments often varies among individual patients, ranging from beneficial effect to even fatal adverse reaction. Pharmacogenomics holds the promise of personalized medicine through elucidating genetic determinants responsible for pharmacological outcomes (e.g., cytotoxicities to anticancer drugs) and therefore guide the prescription decision prior to drug treatment. Besides traditional candidate gene‐based approaches, technical advances have begun to allow application of whole‐genome approaches to pharmacogenomic discovery. In particular, comprehensive understanding of human genetic variation provides the basis for applying GWAS (genome‐wide association studies) in pharmacogenomic research to identify genomic loci associated with pharmacological phenotypes (e.g., individual dose requirement for warfarin). We therefore briefly reviewed the background for pharmacogenetic/pharmacogenomic research with statins and warfarin as examples for the GWAS discovery and their clinical implementation. In conclusion, with some challenges, whole‐genome approaches such as GWAS have allowed unprecedented progress in identifying genetic variants associated with pharmacological phenotypes, as well as provided foundation for the next wave of pharmacogenomic discovery utilizing sequencing‐based approaches. Furthermore, investigation of the complex interactions among genetic and epigenetic factors on the whole‐genome scale will become the post‐GWAS research focus for pharmacologic complex traits. WIREs Syst Biol Med 2013, 5:1–9. doi: 10.1002/wsbm.1199This article is categorized under:

Laboratory Methods and Technologies > Genetic/Genomic Methods
Translational, Genomic, and Systems Medicine > Translational Medicine
Carbon Halide Bond Activation of Aroyl Halides using an NHC‐stabilized Nickel(0) Complex
Authors: Zell Thomas , Radius Udo 
Published: November 2012

AbstractAroyl complexes of the type trans‐[Ni(iPr2Im)2(X)(C(O)Ar)] (X = Cl and Ar = Ph (2), 4‐tBu‐C6H4 (3) and C6F5 (4) and X = Br and Ar = Ph (5)) were prepared by oxidative addition reactions of carboxylic acid halides with the dinuclear nickel(0) complex [Ni2(iPr2Im)4(COD)] (1) (iPr2Im = 1, 3‐diisopropylimidazolin‐2‐ylidene; COD = 1, 5‐cyclooctadien). The reported compounds were characterized by multinuclear NMR spectroscopy, EI‐mass spectroscopy, IR spectroscopy, and elemental analysis. The benzoyl chloride complex trans‐[Ni(iPr2Im)2(Cl)(C(O)Ph)] (2) as well as its bromide analogue trans‐[Ni(iPr2Im)2(Br)(C(O)Ph)] (5) were additionally structurally characterized by single‐crystal X‐ray crystallography. NMR spectra of the crude products revealed the formation of minor amounts of the corresponding bis(halide) complexes trans‐[Ni(iPr2Im)2(Cl)2] (6) and trans‐[Ni(iPr2Im)2(Br)2] (7), depending on the aroyl halide used. Decarbonylation of the benzoyl complexes was observed upon irradiation of the complexes 2 and 5 with UV light. NMR analysis of the resulting mixtures of products revealed the formation of the phenyl halide complexes trans‐[Ni(iPr2Im)2(Cl)(Ph)] (8) and [Ni(iPr2Im)2(Br)(Ph)] (9), as well as the formation of the bis(halide) complexes 6 and 7.
Ln‐Imidazolate Frameworks: The Coordinative Demand of Ln3+ Ions and its Consequences for the Compound Constitution of Different Lanthanides
Authors: Zurawski Alexander , Rybak Jens‐Christoph , Meyer Larissa V. , Müller‐Buschbaum Klaus 
Published: November 2012

AbstractBy syntheses and characterization of the imidazolate frameworks 3∞[Sm3(Im)9(ImH)2]·2ImH, Im– = imidazolate anion, ImH = 1H‐imidazole 3∞[Gd2(Im)6(ImH)1.5]·0.5ImH and 3∞[Dy(Im)3] it is shown that the constitution of 3D‐linked lanthanide imidazolates is variable and refers to the lanthanide contraction and the course of the ionic radii of Ln3+ and thus the coordinative demand of the referring ions. The larger the trivalent ion the more neutral imidazole molecules are incorporated, both coordinating and non‐coordinating starting with no imidazole and homoleptic frameworks for Ln = Tb, Dy and ranging to a ratio Ln:ImH of 1:2 for praseodymium in 3∞[Pr(Im)3(ImH)]·ImH. Samarium and gadolinium mark steps in this course with ratios of 3:4 and 1:1. Although the constitution differs, the lanthanide ions show only a slight change in C.N. ranging from six to seven. Major differences are observed in the framework structures and topologies as well as density concerning available free space after imidazole release. Kagomé nets are a prominent topological feature of imidazole containing constitutions, whereas cubic 4, 6 nets are found for homoleptic imidazolates.