bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanomechanical characterization of micro/nanofiber reinforced type I collagens
Authors: Wang Xinnan , Yan Yongda , Yost Michael J. , Fann Stephen A. , Dong Shen , Li Xiaodong 
Published: March 2007

AbstractTo function properly in the rigorous tissue environment, implanted scaffolds for tissue engineering are required to meet certain standards of strength and mechanical integrity. However, the soft nature and moisture condition of biomaterials impose great challenges to many existing techniques and instrumentations for measuring their mechanical properties at micro/nano scale. In this work, we demonstrate the testing methodologies of micro/nano fiber reinforced type I collagens, and obtain basic mechanical property data of two types of modified collagens‐micro carbon fiber reinforced collagen (MCFR) and nano collagen fiber reinforced collagen (NCFR). Results show that mechanical properties of collagen tissues can be enhanced by reinforcing nano collagen fibers but weakened by micro carbon fiber reinforcements. Mechanisms are discussed on how natures of reinforcing fibers affect reinforcement to the collagen matrix, as well as how reinforcements behave within the collagen matrix in response to mechanical strain. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Morphology and properties of organic–inorganic hybrid materials involving TiO2 and poly(ϵ‐caprolactone), a biodegradable aliphatic polyester
Authors: Li Rui , Nie Kangming , Pang Wenmin , Zhu Qingren 
Published: March 2007

AbstractThe novel biodegradable poly(ϵ‐caprolactone)/titanium dioxide hybrid materials were prepared via in situ sol‐gel process of tetrabutyl titanate (TBT) as inorganic precursor in the presence of PCL. The relationships between morphology, microphase separation, crystalline structure, and properties were investigated by means of XPS, SEM, XRD, DSC, and in vitro degradation test. The microstructures of the bulk hybrids display two‐phase microscopic separation on the nanometer scale, which domain is 20–80 nm. The surface morphology and intermolecular bonding interaction are significantly dependent on inorganic component. The relative crystalline degrees of PCL/TiO2 hybrid nanocomposite materials were controlled by both inorganic component and hydrogen bonding special interaction. The hybrid nanocomposite materials with TiO2 showed faster biodegradation rate than that of pure PCL itself, and the transparency corresponding to microstructure increase with increase of inorganic component content. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Wet chemical silver treatment of endotracheal tubes to produce antibacterial surfaces
Authors: Ramstedt Madeleine , Houriet Raymond , Mossialos Dimitris , Haas Dieter , Mathieu Hans Jörg 
Published: March 2007

AbstractMechanically ventilated patients in hospitals are subjected to an increased risk of acquiring nosocomial pneumonia that sometimes has a lethal outcome. One way to minimize the risk could be to make the surfaces on endotracheal tubes antibacterial. In this study, bacterial growth was inhibited or completely prevented by silver ions wet chemically and deposited onto the tube surface. Through the wet chemical treatment developed here, a surface precipitate was formed containing silver chloride and a silver stearate salt. The identity and morphology of the surface precipitate was studied using x‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and x‐ray powder diffraction. Leaching of silver ions into solution was examined, and bacterial growth on the treated surfaces was assayed using Pseudomonas aeruginosa wild type (PAO1) bacteria. Furthermore, the minimum inhibitory concentration of silver ions was determined in liquid‐ and solid‐rich growth medium as 23 and 18 μM, respectively, for P. aeruginosa. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Effects of growth factors on heparin‐carrying polystyrene‐coated atelocollagen scaffold for articular cartilage tissue engineering
Authors: Sato Masato , Ishihara Masayuki , Ishihara Miya , Kaneshiro Nagatoshi , Mitani Genya , Nagai Toshihiro , Kutsuna Toshiharu , Asazuma Takashi , Kikuchi Makoto , Mochida Joji 
Published: March 2007

AbstractThe specific aim of our investigation is to study the potential use of a collagen/heparin‐carrying polystyrene (HCPS) composite extracellular matrix for articular cartilage tissue engineering. Here, we created a high‐performance extracellular matrix (HpECM) scaffold to build an optimal extracellular environment using an HCPS we originally developed, and an atelocollagen honeycomb‐shaped‐scaffold (ACHMS‐scaffold) with a membrane seal. This scaffold was coated with HCPS to enable aggregation of heparin‐binding growth factors such as FGF‐2 and TGF‐β1 within the scaffold. Three‐dimensional culture of rabbit articular chondrocytes within the HpECM‐scaffold and subsequent preparation of a tissue‐engineered cartilage were investigated. The results showed remarkably higher cell proliferative activity within the HpECM‐pretreated‐FGF‐2 scaffold and the sustenance of phenotype within the HpECM‐pretreated‐TGF‐β1 scaffold. It was thought that both FGF‐2 and TGF‐β1 were stably immobilized in the HpEMC‐scaffold since HCPS generated an extracellular environment similar to that of heparan sulfate proteoglycan within the scaffold. These results suggest that an ACHMS‐scaffold immobilized with HCPS can be a HpECM for cartilage regeneration to retain the heparin‐binding growth factors within the scaffolds. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Cytotoxicity of formaldehyde on human osteoblastic cells is related to intracellular glutathione levels
Authors: Ho Yung‐Chuan , Huang Fu‐Mei , Chang Yu‐Chao 
Published: March 2007

AbstractFormaldehyde that leaches out of formaldehyde‐releasing root canal sealers, specifically from setting material extruded into the periapical region may participate in the development of periapical inflammation or the continuation of a pre‐existing periapical lesion. However, the effects of formaldehyde on human osteoblasts have not been investigated. The aim of this study was to evaluate the mechanisms of cytotoxicity of formaldehyde on human osteoblastic cell line U2OS in vitro. Cytotoxicity and cell proliferation assays were performed to elucidate the adverse effects of formaldehyde on U2OS cells. Formaldehyde demonstrated a cytotoxic effect to U2OS cells in a dose‐dependent manner (p<0.05). The 50% inhibition concentration of formaldehyde was about 3 mM. Formaldehyde also inhibited cell proliferation during a 3‐day culture period (p<0.05). To determine whether glutathione (GSH) levels were important in the cytotoxicity of formaldehyde, we pretreated cells with the GSH precursor, 2‐oxothiazolidine‐4‐carboxylic acid (OTZ) to boost thiol levels, or buthionine sulfoximine (BSO) to deplete GSH. The addition of OTZ acted as a protective effect on the formaldehyde‐induced cytotoxicity (p<0.05). In contrast, the addition of BSO enhanced the formaldehyde‐induced cytotoxicity (p<0.05). Taken together, the levels of formaldehyde tested inhibited cell growth and proliferation on U2OS cells. Formaldehyde has significant potential for periapical toxicity. These inhibitory effects were associated with intracellular GSH levels. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Asymptotic analysis and estimates of blow‐up time for the radial symmetric semilinear heat equation in the open‐spectrum case
Authors: Kavallaris N. I. , Lacey A. A. , Nikolopoulos C. V. , Tzanetis D. E. 
Published: March 2007

AbstractWe estimate the blow‐up time for the reaction diffusion equation ut=Δu+ λf(u), for the radial symmetric case, where f is a positive, increasing and convex function growing fast enough at infinity. Here λ>λ*, where λ* is the ‘extremal’ (critical) value for λ, such that there exists an ‘extremal’ weak but not a classical steady‐state solution at λ=λ* with
∥w(⋅, λ)∥∞→∞ as 0<λ→λ*−. Estimates of the blow‐up time are obtained by using comparison methods. Also an asymptotic analysis is applied when f(s)=es, for λ−λ*≪1, regarding the form of the solution during blow‐up and an asymptotic estimate of blow‐up time is obtained. Finally, some numerical results are also presented. Copyright © 2007 John Wiley & Sons, Ltd.
A coupled simulation of an explosion inside a lined cavity surrounded by a plastic compressible medium
Authors: Feldgun V. R. , Kochetkov A. V. , Karinski Y. S. , Yankelevsky D. Z. 
Published: March 2007

AbstractThe paper develops a coupled approach to simulate an axisymmetric explosion inside a buried lined cavity. The approach allows accounting for all the stages of the process: detonation of the internal charge; the shock wave propagation in the internal gas with further interaction with the lining, including multiple reflections; soil–structure dynamic interaction, including multiple gap openings and closures and wave propagation in the surrounding compressible plastic medium.The interaction problem is solved by a combination of the variational difference method and of the modified Godunov's method based on the fixed Eulerian mesh with the so‐called mixed cell. The contact pressures acting on the lining due to both detonation products and soil–lining interaction are computed through the solution of the joint system of finite difference equations of gas, shell and soil dynamics using a simple iteration method. Copyright © 2007 John Wiley & Sons, Ltd.
Determining the finite elasticity reference state from a loaded configuration
Authors: Rajagopal Vijayaraghavan , Chung Jae‐Hoon , Bullivant David , Nielsen Poul M. F. , Nash Martyn P. 
Published: March 2007

AbstractThere are a number of situations where the deformed configuration of a body is known and it is necessary to determine the reference state. Previous methods developed to calculate the reference state involve the formulation of the finite elasticity equations in terms of the deformed configuration. This paper demonstrates that the undeformed reference state can be accurately determined from a deformed configuration and the associated loading conditions, by using conventional finite elasticity balance equations together with a solution procedure that treats the reference configuration as the unknowns. The mathematical theory behind the solution method is described, validated with an analytical solution, and verified using experimental studies on gel phantoms. The practical utility of this method is then demonstrated in the field of breast biomechanics. Copyright © 2007 John Wiley & Sons, Ltd.
Flutter simulations of a T‐tail configuration using non‐linear aerodynamics
Authors: Arizono H. , Kheirandish H. R. , Nakamichi J. 
Published: March 2007

AbstractA numerical flutter simulation of a T‐tail configuration in the transonic region is presented. A code for aeroelastic simulations based on the multi‐block and overset grid concept was developed and has been applied to a T‐tail configuration. Flutter simulations are performed at Mach numbers in the range 0.70–0.95, and the obtained results correspond to experimental results. The effect of varying the angle of attack on the flutter boundary is also presented. Copyright © 2007 John Wiley & Sons, Ltd.
Polyurethane based on hydroxyl‐terminated polybutadienes
Authors: Ryan P. W. 
Published: March 2007

AbstractButadiene has been found to homopolymerise and copolymerise with other reactive vinyl monomers to yield unique liquid polymers which are terminated with reactive allylic hydroxyl groups. Through the use of an isocyanate cure reaction they offer a route to liquid castable general purpose elastomers, capable of reinforcement with various fillers and extension with a wide variety of low cost process oils.
Thermal stability of aromatic polyimides: Factors affecting the oxidative stability of poly‐N, N′‐(4,4′‐diphenyl ether) pyromellitimide
Authors: Dine‐Hart R. A. , Wright W. W. 
Published: March 2007

AbstractPolyimide samples in the form of powders, films and sintered mouldings were prepared from pyromellitic dianhydride and 4,4′‐diaminodiphenyl ether. The effect of environmental variables on the oxidative stability at 400°C of the high molecular weight films was studied, and it was shown that hydrolytic processes could greatly accelerate the degradation. The higher stability of powders was attributed to the presence of low molecular weight fractions which could inhibit these hydrolytic processes. Improvement of the stability of the films by the addition of low molecular weight materials during the casting process and the destabilisation of powders by prolonged solvent extraction gave support to this hypothesis.For comparison of thermal stabilities of polypyromellitimides of differing chemical structure weight loss results should therefore be determined on high molecular weight films under controlled humidity conditions.
Safeners coordinately induce the expression of multiple proteins and MRP transcripts involved in herbicide metabolism and detoxification in Triticum tauschii seedling tissues
Authors: Zhang Qin , Xu Fangxiu , Lambert Kris N. , Riechers Dean E. 
Published: March 2007

AbstractChemicals called safeners protect cereal crops from herbicide toxicity. Proteomic methods (2‐D PAGE and LC‐MS/MS) were utilized to identify safener‐ and/or herbicide‐regulated proteins in three tissues (root, leaf, and coleoptile) of Triticum tauschii seedlings to better understand a safener's mechanism of action. Growth experiments showed that the safener cloquintocet‐mexyl protected seedlings from injury by the herbicide dimethenamid. In total, 29 safener‐induced and 10 herbicide‐regulated proteins were identified by LC‐MS/MS. These proteins were classified into two major categories based on their expression patterns, and were further classified into several functional groups. Surprisingly, mutually exclusive sets of proteins were identified following herbicide or safener treatment, suggesting that different signaling pathways may be recruited. Safener‐responsive proteins, mostly involved in xenobiotic detoxification, also included several new proteins that had not been previously identified as safener‐responsive, whereas herbicide‐regulated proteins belonged to several classes involved in general stress responses. Quantitative RT‐PCR revealed that multidrug resistance‐associated protein (MRP) transcripts were highly induced by safeners and two MRP genes were differentially expressed. Our results indicate that safeners protect T. tauschii seedlings from herbicide toxicity by coordinately inducing proteins involved in an entire herbicide detoxification pathway mainly in the coleoptile and root, thereby protecting new leaves from herbicide injury.
Identification of proteins involved in osmotic stress response in Enterobacter sakazakii by proteomics
Authors: Riedel Kathrin , Lehner Angelika 
Published: March 2007

AbstractEnterobacter sakazakii is considered an opportunistic food‐borne pathogen, causing rare but significant illness especially in neonates. It has been proposed that the organism is relatively resistant to osmotic and dry stress compared to other species of the Enterobacteriaceae group. To understand the mechanisms involved in osmotic stress response, 2‐DE protein analysis coupled to MALDI‐TOF MS was employed to investigate changes in the protein profiles of E. sakazakii cells in response to two different types of osmotic stress (physical desiccation and growth in hyperosmotic media). In total, 80 differentially expressed protein spots corresponding to 53 different protein species were identified. Affiliation of proteins to functional categories revealed that a considerable number of the differentially expressed proteins from desiccated and hyperosmotic grown samples belonged to the same functional category but were regulated in opposite directions. Our data show that the protein pattern of NaCl‐grown cultures reflect more or less a general down‐regulation of central metabolic pathways, whereas adaptation of (non‐growing) cells in a desiccated state represents an accumulation of proteins that serve some structural or protective role. The most striking effects observed for both types of osmotic stress in E. sakazakii were a significant down‐regulation of the motility apparatus and the formation of filamentous cells.
Proteomic profile of mouse fibroblasts with a targeted disruption of the peroxisome proliferator activated receptor‐β/δ gene
Authors: Adamkiewicz Jürgen , Kaddatz Kerstin , Rieck Markus , Wilke Bernhard , Müller‐Brüsselbach Sabine , Müller Rolf 
Published: March 2007

AbstractThe peroxisome proliferator activated receptor‐β (PPARβ) plays an essential role in lipid metabolism, immune modulation, differentiation and cell proliferation. There is also strong evidence for a function in oncogenesis and tumor vascularization, but the underlying molecular mechanisms remain elusive. In the present study, we have used fibroblasts derived from Pparb wild‐type and null mice to determine by 2‐DE and PMF analysis the contribution of PPARβ to the protein profile of fibroblasts. Thirty‐one differentially expressed proteins of different functional categories were identified. For at least two proteins a role in tumorigenesis and/or tumor vascularization has previously been reported: while the calcium intracellular channel‐4 (CLIC4) was expressed at lower levels in Pparb null cells, expression of the cellular retinol binding protein 1 (CRBP1) was enhanced. Clic4 and Crbp1 gene expression patterns observed in different experimental settings in vitro and in vivo confirmed the proteomics data. Our findings indicate that the expression of a defined set of proteins is altered in fibroblasts and endothelial cells from Pparb null mice, that this is due to aberrant gene regulation, and that the altered expression of these proteins is consistent with the tumor vascularization phenotype of Pparb null mice.
Comparative proteomic analysis associated with term placental insufficiency in cloned pig
Authors: Lee So‐Young , Park Jong‐Yi , Choi Yun‐Jung , Cho Seong‐Keun , Ahn Jong Deok , Kwon Deug‐Nam , Hwang Kyu‐Chan , Kang Sung‐Jo , Paik Seung‐Sam , Seo Han Geuk , Lee Hoon Taek , Kim Jin‐Hoi 
Published: March 2007

AbstractSomatic cell‐derived nuclear transfer (scNT) is a method of animal cloning in which the oocyte reprograms a somatic cell nucleus to divide and execute developmental programs. Despite many successes in this field, cloning by scNT remains very inefficient. Unlike other cloned animals, pigs derived by scNT have placentas with severe villous hypoplasia. To obtain a better understanding of the protein networks involved in this phenomenon, we assessed global protein expression profiles in term placentas from scNT‐derived and control animals. Proteomic analysis of term placentas from scNT‐derived animals identified 43 proteins that were differentially expressed compared to control animals. Among them, 14‐3‐3 proteins and Annexin V, which are closely involved in the apoptotic signaling pathway, were significantly down‐ and up‐regulated, respectively. Western blot analysis and immunohistochemistry indicated that down‐regulation of 14‐3‐3 proteins in scNT‐derived placentas induced apoptosis of cytotrophoblast cells via mitochondria‐mediated apoptosis. Taken together, our results suggest that placental insufficiency in scNT‐derived placentas may be due to apoptosis, induced in part by the down‐regulation of 14‐3‐3 proteins and up‐regulation of Annexin V. They also indicate that proteomic maps represent an important tool for future studies of placental insufficiency and pathology.
Deca‐2, 4, 6‐trienoic acid, a new conjugated fatty acid, isolated from the latex ofEuphorbia pulcherrima willd
Authors: Warnaar Frans 
Published: March 2007

AbstractFrom the latex ofEuphorbia pulcherrima, a new conjugated trienoic fatty acid was isolated and identified as deca‐trans‐2,trans‐4,cis‐6‐trienoic acid. Four other isomers of this acid were also present as minor components. The acids were esterified with trieterpenols.
Antimicrobial lipids: Natural and synthetic fatty acids and monoglycerides
Authors: Kabara J. J. , Vrable R. , Lie Ken Jie M. S. F. 
Published: March 2007

AbstractOver 40 natural or synthetic lipophilic compounds were screened for antimicrobial activity. Gram (+) bacteria and yeasts but not Gram (−) bacteria were affected by these agents. Epimino and selena fatty acids are more active than their corresponding straight chain unsubstituted fatty acids. The position of selenium influenced the antimicrobial activity of the fatty acid. The presence and position of a double or triple bond, usually an important factor in long chain fatty acids (>C14) had little or no effect in C11 fatty acids. Optimum antimicrobial activity was found for fatty acids and their corresponding monoglycerides when the chain length was C12. The dilaurin derivative was not active.
Improving the field production environment for soybeans
Authors: Lam‐Sánchez A. 
Published: March 2007

AbstractDuring the past 10 years, soybeans have reached a prominent position among crops in the world. A substantial contribution to world production has been achieved by tropical countries, due to favorable conditions for high yields. Two limitations keep commercial yields below those obtained in experimental results (above 3,000 kg/ha): one is the lack of local adapted varieties and the other is an adequate field production environment. Solutions must be obtained by local research data. Seedbed preparation is one of the most important production steps, since the other production practices are dependent on it. Conventional methods and minimum tillage, when soybeans follow another crop, are being used, with the problem of soil compaction and losses by erosion. Looking for superior strains ofRhizobium is crucial because nitrogen can be supplied by a proper symbiosis. The addition of limestone to the soil is a common practice used to raise the pH to proper levels. The use of fertilizers should be guided by local research findings. Chemical control of weeds, pests and diseases is needed to prevent yield losses, but possible effects on the environment should be considered.
The soybean marketing systems
Authors: Bader K. L. 
Published: March 2007

AbstractThe movement of soybeans from producers to final users is a complex system involving numerous changes in ownership, form, time and space. Defining the market for soybeans is not a simple task nor is the marketing system easily delineated. The purpose of this paper is to outline the general movement of soybeans from harvest to final user including the various alternatives existent in the present system of marketing grains. An equally important objective is to point out that such a complex, worldwide system functions so effectively. The demand for protein and vegetable oil, so vital to world nutrition, is being largely met by a system of free market decisions. Certainly, governments have a hand in the markets in varying degrees, but by and large, soybeans are produced and moved based on the profit motive. Essential to the continuation of an effective world market is a recognition of the merits of the system that has enabled soybeans to be economically used in almost all parts of the world. This recognition will ensure continued success and perhaps help alleviate existing market inequities.