bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous LIF and retro‐reflected beam interference detection for CE
Authors: Xiong Bo , Wang Wei , Miao Xueyan , Zhou Xiaodong , Deng Yanzhuo , Zhou Ping , Hu Jiming 
Published: November 2008

AbstractThis Short Communication describes a novel optical detection method for CE, based on the combination of LIF detection and retro‐reflected beam interference detection. By the use of a side‐illuminated laser beam, an on‐column multifunctional detection for CE has been developed, and some key elements in the scheme have been optimized. In addition, two miscellaneous samples including fluorescent dyes, carbohydrates and amino acids have been determined to evaluate its performance. Without any additional pretreatment, sufficient LOD and linear ranges have been achieved for most analytes. Its performance in retro‐reflected beam interference detection is better than those mentioned in a former report, and its fluorescent sensitivity is comparable with the achievable sensitivity by conventional LIF systems, all of which together combine high sensitivity and universal analysis to a certain extent.
Development of a stability‐indicating CE assay for the determination of amlodipine enantiomers in commercial tablets
Authors: Fakhari Ali Reza , Nojavan Saeed , Haghgoo Soheila , Mohammadi Ali 
Published: November 2008

AbstractA simple, accurate, precise and sensitive method using CD for separation and stability indicating assay of enantiomers of amlodipine in the commercial tablets has been established. Several types of CD were evaluated and best results were obtained using a fused‐silica capillary with phosphate running buffer (100 mM, pH 3.0) containing 5 mM hydroxypropyl‐α‐CD. The method has shown adequate separation for amlodipine enantiomers from its degradation products. The drug was subjected to oxidation, hydrolysis, photolysis and heat to apply stress conditions. The range of quantitation for both enantiomers was 5–150 μg/mL. Intra‐ and inter‐day RSD (n=6) was <4%. The limit of quantification that produced the requisite precision and accuracy was found to be 5 μg/mL for both enantiomers. The LOD for both enantiomers was found to be 0.5 μg/mL. Degradation products produced as a result of stress studies did not interfere with the detection of enantiomers and the assay can thus be considered stability indicating.
Post‐quake decision analysis using dynamic programming
Authors: Yeo Gee Liek , Cornell C. Allin 
Published: November 2008

AbstractWe introduce a general decision analysis procedure based on stochastic dynamic programming in the post‐quake aftershock environment. The damage sustained by the building due to the mainsheet, the time‐varying aftershock rates and the potential for further damage progression in the post‐quake environment are all factors taken into consideration in the proposed methodology. This procedure enables the optimal decision after the mainshock to be selected based on the minimization of expected financial losses, subject to a constraint on a minimal level of individual life‐safety, using a consistent probabilistic framework to explicitly quantify the uncertainties in the variables. Copyright © 2008 John Wiley & Sons, Ltd.
Comparison of hard‐decision and soft‐decision channel codedM‐ary PPM performance over free space optical links
Authors: Muhammad S. Sheikh , Javornik Tomaž , Jelovčan Igor , Ghassemlooy Zabih , Leitgeb Erich 
Published: November 2008

AbstractError control codedM‐ary pulse position modulation (PPM) can be used over free space optical links to mitigate the atmospheric attenuations and the turbulence induced fading. In this paper, we present performance analysis for coded free space optics (FSO) communication systems operating over various atmospheric conditions. We justify the selection of higher state PPM as an appropriate modulation scheme for the links and provide a comparative analysis between hard decision decoded (Reed‐Solomon, RS) and soft decision decoded (Turbo) channel coded PPM over varying link conditions. Simulation results strongly indicate RS‐coded PPM as a robust and well‐performing coded‐modulation scheme for the FSO links. Copyright © 2008 John Wiley & Sons, Ltd.
A nodal integral method for quadrilateral elements
Authors: Nezami Erfan G. , Singh Suneet , Sobh Nahil , Rizwan‐uddin  
Published: November 2008

AbstractNodal integral methods (NIMs) have been developed and successfully used to numerically solve several problems in science and engineering. The fact that accurate solutions can be obtained on relatively coarse mesh sizes, makes NIMs a powerful numerical scheme to solve partial differential equations. However, transverse integration procedure, a step required in the NIMs, limits its applications to brick‐like cells, and thus hinders its application to complex geometries. To fully exploit the potential of this powerful approach, abovementioned limitation is relaxed in this work by first using algebraic transformation to map the arbitrarily shaped quadrilaterals, used to mesh the arbitrarily shaped domain, into rectangles. The governing equations are also transformed. The transformed equations are then solved using the standard NIM. The scheme is developed for the Poisson equation as well as for the time‐dependent convection–diffusion equation. The approach developed here is validated by solving several benchmark problems. Results show that the NIM coupled with an algebraic transformation retains the coarse mesh properties of the original NIM. Copyright © 2008 John Wiley & Sons, Ltd.
Mechanisms involved in the down‐regulation of TCR ζ chain in tumor versus peripheral blood of oral cancer patients
Authors: Kulkarni Dakshayini P. , Wadia Persis P. , Pradhan Trupti N. , Pathak Alok Kumar , Chiplunkar Shubhada V. 
Published: November 2008

AbstractImmune dysfunction is the hallmark of patients with oral cancer. Down‐regulation of T cell receptor (TCR) ζ chain expression was observed in T cells from patients with oral squamous cell carcinoma. In peripheral blood, the decrease in TCR ζ chain showed an inverse correlation with the tumor stage as demonstrated by western blotting, confocal microscopy and flow cytometry. The mechanism of TCR ζ chain degradation in the peripheral blood involves ubiquitination and subsequent targeting of TCR ζ for degradation in the lysosome. Decreased expression of PKC θ and the subsequent decrease of TCR ζ chain transcription factor Elf‐1 and its binding to DNA may contribute to the decreased/or absent TCR ζ chain transcripts in the tumor infiltrating lymphocytes. Oral cancer patients exhibiting TCR ζ chain defect also showed impaired lymphocyte proliferation, cytokine profile and intracellular calcium release upon stimulation with anti CD3 mAb. Our data shows that posttranslational degradation is primarily responsible for decreased TCR ζ chain expression in the peripheral blood, while a transcriptional defect is observed in the tumor compartment. The down‐regulation of TCR ζ chain culminates into impaired lymphocyte responses in these patients. © 2008 Wiley‐Liss, Inc.
The role of p44/42 activation in tributyltin‐induced inhibition of human natural killer cells: effects of MEK inhibitors
Authors: Abraha Abraham B. , Whalen Margaret M. 
Published: November 2008

AbstractDestruction of tumor cells is a key function of natural killer (NK) cells. Previous studies have shown that tributyltin (TBT) can significantly reduce the lytic function of the human NK cells with accompanying increases in the phosphorylation (activation) states of the mitogen activated protein kinases (MAPKs), p44/42. The current studies examine the role of p44/42 activation in the TBT‐induced reduction of NK‐lytic function, by using MAPK kinase (MEK) inhibitors, PD98059 and U0126. A 1 h treatment with PD98059 or U0126 or both decreased the ability of NK cells to lyse K562 tumor cells. PD98059, U0126 or a combination of both inhibitors were able to completely block TBT‐induced activation of p44/42. However, when p44/42 activation was blocked by the presence of PD98059, U0126 or the combination, subsequent exposure to TBT was still able to decrease the lytic function of NK cells. These results indicate that TBT‐induced activation of p44/42 occurs via the activation of its upstream activator, MEK, and not by a TBT‐induced inhibition of p44/42 phosphatase activity. Additionally, as lytic function was never completely blocked by MEK inhibitors, the results indicate that activation of p44/42 pathway is not solely responsible for the activation of lytic function of freshly isolated human NK cells. Finally, the results showed that TBT‐induced activation of p44/42 is not solely responsible for the loss of lytic function. Copyright © 2008 John Wiley & Sons, Ltd.
Immobilization and controlled release of prostaglandin E2 from poly‐L‐lactide‐co‐glycolide microspheres
Authors: Brochhausen Christoph , Zehbe Rolf , Watzer Bernhard , Halstenberg Sven , Gabler Franziska , Schubert Helmut , Kirkpatrick Charles James 
Published: November 2008

AbstractProstaglandin E2 (PGE2) is an arachidonic acid metabolite involved in physiological homeostasis and numerous pathophysiological conditions. Furthermore, it has been demonstrated that prostaglandins have a stimulating effect not only on angiogenesis in situ and in vitro but also on chondrocyte proliferation in vitro. Thus, PGE2 represents an interesting signaling molecule for various tissue engineering strategies. However, under physiological conditions, PGE2 has a half‐life time of only 10 min, which limits its use in biomedical applications. In the present study, we investigated if the incorporation of PGE2 into biodegradable poly‐L‐lactide‐co‐glycolide microspheres results in a prolonged release of this molecule in its active form. PGE2‐modified microspheres were produced by a cosolvent emulsification method using CHCl3 and HFIP as organic solvents and PVA as emulsifier. Thirteen identical batches were produced; and to each batch 1.0 mL of serum‐free medium was added. The medium was removed at defined time points and then analyzed by gas chromatography tandem mass spectrometry (GC/MS/MS) to measure the residual PGE2 content. In this study we demonstrated the prolonged release of PGE2, showing a linear increase over the first 12 h, followed by a plateau and a slow decrease. The microspheres were further characterized by scanning electron microscopy. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Protein adsorption on derivatives of hyaluronic acid and subsequent cellular response
Authors: Lord Megan S. , Pasqui Daniela , Barbucci Rolando , Milthorpe Bruce K. 
Published: November 2008

AbstractThe modulation of biological interactions with artificial surfaces is a vital aspect of biomaterials research. Serum protein adsorption onto photoreactive hyaluronic acid (Hyal‐N3) and its sulfated derivative (HyalS‐N3) was analyzed to determine extent of protein interaction and protein conformation as well as subsequent cell adhesion. There were no significant (p < 0.01) differences in the amount of protein adsorbed to the two polymers; however, proteins were found to be more loosely bound on HyalS‐N3 compared with Hyal‐N3. Fibronectin was adsorbed onto HyalS‐N3 in such an orientation as to allow the availability of the cell binding region, while there was more restricted access to this region on fibronectin adsorbed onto Hyal‐N3. This was confirmed by reduced cell adhesion on fibronectin precoated Hyal‐N3 compared with fibronectin precoated HyalS‐N3. Minimal cell adhesion was observed on albumin and serum precoated Hyal‐N3. The quartz crystal microbalance confirmed that specific cell‐surface interactions were experienced by cells interacting with the fibronectin precoated polymers and serum precoated HyalS‐N3. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Characterization of esterified hyaluronan‐gelatin polymer composites suitable for chondrogenic differentiation of mesenchymal stem cells
Authors: Angele Peter , Müller Rainer , Schumann Detlef , Englert Carsten , Zellner Johannes , Johnstone Brian , Yoo Jung , Hammer Joachim , Fierlbeck Johann , Angele Martin K. , Nerlich Michael , Kujat Richard 
Published: November 2008

AbstractComposite scaffolds of homogeneously mixed esterified hyaluronan (HY) and gelatin (G) were manufactured with variable component compositions (HY100%; HY95%/G5%; HY70%/G30%). The goals of this study were to analyze the produced composite scaffolds using physical and chemical methods, for example, scanning electron microscopy, IR‐spectroscopy, water contact angle, protein assay, and tensile testing as well as to assess the effects of adding gelatin to the composite scaffolds on attachment, proliferation, and chondrogenic differentiation of human mesenchymal stem cells. Numbers of attached cells were significantly higher on the composite material compared to pure hyaluronan at different time points of two‐dimensional or three‐dimensional cell culture (p< 0.02). In composite scaffolds, a significantly greater amount of cartilage‐specific extracellular matrix components was deposited after 28 days in culture (glycosaminoglycan: p < 0.001; collagen: p < 0.001) as compared with 100% hyaluronan scaffolds. Additionally, gelatin‐containing composite scaffolds displayed stronger promotion of collagen type II expression than pure hyaluronan scaffolds. The mechanism, based on which gelatin influences cell adhesion, was examined. The effect was inhibited by collagenase treatment of the composites or by addition of α5β1‐integrin blocking antibodies to the cell suspension. In summary, the results describe the establishment of a class of composite polymer scaffolds, consisting of esterified hyaluronan and gelatin, which are potentially useful for cell‐based tissue engineering approaches using mesenchymal stem cells for chondrogenic differentiation. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Effects of nerve growth factor from genipin‐crosslinked gelatin in polycaprolactone conduit on peripheral nerve regeneration—In vitro and in vivo
Authors: Chang Chen‐Jung 
Published: November 2008

AbstractThe gelatin solution crosslinked by genipin (0, 0.1, 0.5, 1.0, and 1.5% w/w) was studied as a nerve growth factor (NGF) carrier (GGp0, GGp0.1, GGp0.5, GGp1.0, and GGp1.5) in a polycaprolactone conduit in large‐gap nerve regeneration. The GGp0 and GGp0.1 displayed the highest activity of PC12 cells and inhibited the reduction of 3‐(4,5‐dimethylthiazol‐2‐yl)2,5‐diphenyl‐tetrazolium bromide (MTT). No cytotoxicity was found in all groups by lactate dehydrogenase (LDH) release. The NGF‐releasing characters were obtained by ELISA tests. A relatively fast release rate appeared during the first 10 days and then a subsequent slower release profile followed. NGF was higher in GGp0.1 than in GGp0 and GGp0.1 after 10 days. The bioactivity of the released NGF remains the same when measuring the neurite outgrowth of PC 12 cells. Finally, the controlled‐release conduits were implanted into 12‐mm long sciatic nerve gaps of rats. In addition, the best site of NGF carrier was determined either by filling carrier into the conduit lumen or by sucking carrier to the conduit wall. Four and 8 weeks after implantation, morphological analysis revealed that GGp0.1 conduits had markedly larger and more number of myelin axons in the midconduit and distal nerve. Further, sucking the carrier into the conduit wall was an efficient and convenient way to prevent the regeneration of axons and vessels from being impaired by the lumen's carrier. The genipin‐crosslinked gelatin is a promising carrier in producing a high release concentration and a long release period of NGF to promote the regeneration over a large‐gap nerve injury. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Development of transgenic endothelial progenitor cell‐seeded stents
Authors: Zhou Zhenhua , Shi Shugui , Song Mingbao , Huang Heqing , Chen Kangning , Mi Jianhong , Li Lusi , Chen Guisheng , Hou Chunli , Huang Guangyu , Zhu Chuhong 
Published: November 2008

AbstractEndothelial progenitor cell (EPC)‐seeded intravascular stents may reduce or prevent in‐stent restenosis. A20 can play an important role for preventing vascular restenosis. Therefore, it is very important how to enhance the seeding efficiency of A20‐modified EPCs on the stent for preventing in‐stent restenosis. To approach this problem, we developed a novel transgenic EPC‐seeded stent and evaluated its feasibility and efficiency. EPCs were isolated and purified from umbilical blood using immunomagnetic beads and then transfected with the A20 gene. One stent type (type 1) was coated with EDC cross‐linked collagen, and another stent type (type 2) was coated with EDC cross‐linked collagen and bound to the CD34 antibody using the bifunctional coupling agent N‐succinmidyl3‐(2‐pyridyldithio) propionate (SPDP). Then, the stents were seeded with EPCs transfected with the A20 gene. The stents were implanted in biological artificial vessels, and cell adhesion was determined in a flow chamber. Cell growth was also measured. EPCs were transfected successfully with the A20 gene. The cells covered both types of stents with favorable biological function. After placement in a flow chamber, the number of cells attached to type 1 stents significantly dropped and their distribution was scattered. Type 2 stents were basically covered with cells and there were more cells on type 2 stents than on type 1 stents (p < 0.01). Collagen‐coupled antibody effectively improves the seeding of transgenic EPCs, offering a new choice of stents to prevent restenosis caused by vascular disease after interventional treatment.© 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Diamond‐like carbon coatings enhance scratch resistance of bearing surfaces for use in joint arthroplasty: Hard substrates outperform soft
Authors: Roy Marie E. , Whiteside Leo A. , Katerberg Brian J. 
Published: November 2008

AbstractThe purpose of this study was to test the hypotheses that diamond‐like carbon (DLC) coatings will enhance the scratch resistance of a bearing surface in joint arthroplasty, and that a hard ceramic substrate will further enhance scratch resistance by reducing plastic deformation. We tested these hypotheses by applying a hard DLC coating to medical‐grade cobalt chromium alloy (CoCr) and magnesia‐stabilized zirconia (Mg‐PSZ) femoral heads and performing scratch tests to determine the loads required to cause cohesive and adhesive fracture of the coating. Scratch tracks of DLC‐coated and noncoated heads were then scanned by optical profilometry to determine scratch depth, width, and pile‐up (raised edges), as measures of susceptibility to scratching. DLC‐coated CoCr specimens exhibited cohesive coating fracture as wedge spallation at an average load of 9.74 N, whereas DLC‐coated Mg‐PSZ exhibited cohesive fracture as arc‐tensile cracks and chipping at a significantly higher average load of 41.3 N (p < 0.0001). At adhesive coating fracture, DLC‐CoCr delaminated at an average load of 35.2 N, whereas DLC‐Mg‐PSZ fractured by recovery spallation at a significantly higher average load of 46.8 N (p < 0.05). Both DLC‐CoCr and DLC‐Mg‐PSZ specimens exhibited significantly shallower scratches and less pile‐up than did uncoated specimens (p < 0.005 and p < 0.01, respectively). However, the harder ceramic substrate of DLC‐Mg‐PSZ better resisted plastic deformation, requiring significantly higher loads for cohesive and adhesive coating fracture. These findings supported both of our hypotheses. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
An in vivo evaluation of the biocompatibility of anodic plasma chemical (APC) treatment of titanium with calcium phosphate
Authors: Schlegel P. , Hayes J. S. , Frauchiger V. M. , Gasser B. , Wieling R. , Textor M. , Richards R. G. 
Published: November 2008

AbstractImplant loosening is an unresolved complication associated with prosthetics. Previous studies report improved osseointegration with hydroxyapatite (HA) or tri‐calcium phosphate coatings. Unfortunately, the brittleness and low strength of these coatings in adhesion to the implant or internal cohesion is problematic, restricting their use. Anodic plasma‐chemical (APC) treatment, an advanced anodisation method, allows for porous oxide layer formation with incorporation of calcium and phosphate directly into the oxide. This produces superior adhesive strength than a conventional coating of calcium phosphate offering potential for long‐term osseointegration. Although the cytocompatibility of several APC treatments have been previously shown, this study was the first to investigate the biocompatibility and osteoconductivity of APC surfaces in vivo when compared with standard HA coated and noncoated commercially pure titanium implant cortical screws. Sample screws were implanted in female Swiss alpine sheep for 12 weeks. Bone remodelling in situ, differences in bone apposition resulting in cortical thickening as well as peak removal torque measurements were assessed. We found no significant differences between the tested coatings and no delamination was observed with any of the APC‐treated surfaces. The results suggest that APC‐treated samples have similar biological performance to HA‐coated screws. In our opinion, APC treatment, which also has superior binding strength to the base metal compared with standard HA coatings as well as similar biocompatibility as shown here, holds great potential for biomedical applications. Now that the in vivo biocompatibility has been proven, the work is being extended to more challenging in vivo models. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Development of chitosan–ellagic acid films as a local drug delivery system to induce apoptotic death of human melanoma cells
Authors: Kim Sungwoo , Liu Yongxing , Gaber M. Waleed , Bumgardner Joel D. , Haggard Warren O. , Yang Yunzhi 
Published: November 2008

AbstractThis study was designed to develop a local chemotherapy device using chitosan as a local drug carrier and ellagic acid (EA) as an anticancer drug. We fabricated chitosan–ellagic acid (Ch–EA) films with concentrations of 0, 0.05, 0.1, 0.5, and 1% (w/v) of EA and examined the films using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and contact angle measurement. The WM115 human melanoma cell line as a skin cancer model was used to evaluate cell response to the films with the MTS assay and apoptosis assay, and HS68 human newborn fibroblast cell line as a control. With the increase in the concentration of the EA, the composite films exhibit increasing amide and ester groups and diffraction peaks of the crystallized EA and greater surface roughness and hydrophilicity. The chitosan films with 0.5 and 1% (w/v) of EA were found to have a potent antiproliferative effect on the melanoma cells by inducing apoptotic cell death. Localized effect of composites on cell behaviors has been clearly demonstrated. Our study demonstrated that the novel Ch–EA film can be potentially used in local chemotherapy. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009