bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalytic Strategies for Changing the Energy Content and Achieving CC Coupling in Biomass‐Derived Oxygenated Hydrocarbons
Authors: Simonetti Dante A. , Dumesic James A.
Published: August 2008

This Concept examines the opportunities for the use of biomass feedstocks in the production of liquid fuels for the transportation sector of society. The cost‐competitive conversion of biomass into liquid fuels involves the integration of processes that operate on lignocellulosic feeds with processes that convert specific fractions of lignocellulose. A brief description of current energy systems is given to indicate the potential contributions of biomass to replace fossil fuel feedstocks for energy production, followed by a description of current biomass‐conversion technologies. Specific focus is given to promising reaction pathways and novel research opportunities for conversion of the carbohydrate fraction of lignocellulose into fuels with targeted structures.
Electrodermal reactivity during the Trier Social Stress Test for children: Interaction between the serotonin transporter polymorphism and children's attachment representation
Authors: Gilissen Renske , Bakermans‐Kranenburg Marian J. , van IJzendoorn Marinus H. , Linting Mariëlle
Published: August 2008

This study explores the relation between variations in the serotonin transporter gene (5‐HTTLPR; long vs. short allele), the child's attachment representation (assessed with the Attachment Story Completion Task, reflecting the security of the parent‐child relationship), and electrodermal reactivity during a public speaking task, the Trier Social Stress Test for Children (TSST‐C) in a sample of 92 7‐year‐old. Electrodermal reactivity during the TSST‐C was not directly associated with variations in 5‐HTT. However, there was a significant gene‐environment interaction effect of 5‐HTT and attachment security on electrodermal reactivity. Results are interpreted in terms of cumulative protection: Children with a secure attachment representation as well as long 5‐HTT alleles appeared to be less stressed during the TSST‐C. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 615–625, 2008.
Influence of prenatal psychosocial stress on cytokine production in adult women
Authors: Entringer Sonja , Kumsta Robert , Nelson Edward L. , Hellhammer Dirk H. , Wadhwa Pathik D. , Wüst Stefan
Published: August 2008

The aim of the present study was to determine the association between prenatal stress and immune function in human adults. Peripheral blood mononuclear cells (PBMCs) from 34 healthy young women whose mothers experienced major negative life events during their pregnancy (Prenatal Stress, PS group, mean age 25, SD ± 4.34 years), and from a female comparison group (n = 28, CG, mean age 24 ± 3.40 years), were stimulated with phytohemagglutinin (PHA), and subsequent cytokine production was measured. A bias for T‐helper 2 (Th2) cytokine production due to an overproduction of IL‐4 relative to IFN‐γ after PHA stimulation was observed in PS subjects. In addition, IL‐6 and IL‐10 were also significantly elevated. To the best of our knowledge, this study is the first to suggest a direct association between prenatal stress exposure and alterations in immune parameters in adult women. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 579–587, 2008.
What potential role is there for medication treatment in anorexia nervosa?
Authors: Crow Scott J. , Mitchell James E. , Roerig James D. , Steffen Kristine
Published: August 2008

Objective:

To review selected issues regarding the development of drug treatments for anorexia nervosa (AN).

Method:

The existing pharmacotherapy literature for AN is reviewed, and the theoretical and practical considerations are discussed.

Results:

A very wide variety of drugs have been examined in AN, generally with negative results. There are a number of potential reasons for this finding, including compliance, nutritional deficits, selection of the wrong targets or the wrong outcome measures, use of monotherapy, lack of animal models, or factors intrinsic to AN.

Conclusion:

Pharmacotherapy provides little benefit in the treatment of AN at present. Several strategies might lead to the identification of more effective agents, including new measurement strategies, identification of novel pharmacologic targets, and consideration of a clinical trials network. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord 2009
Fabrication of Glucose Biosensor Based on Encapsulation of Glucose‐Oxidase on Sol‐Gel Composite at the Surface of Glassy Carbon Electrode Modified with Carbon Nanotubes and Celestine Blue
Authors: Noorbakhsh Abdollah , Salimi Abdollah , Sharifi Ensiyeh
Published: August 2008

A simple procedure was developed to prepare a glassy carbon electrode modified with multi walled carbon nanotubes (MWCNTs) and Celestin blue. Cyclic voltammograms of the modified electrode show stable and a well defined redox couple with surface confined characteristic at wide pH range (2–12). The formal potential of redox couple (E′) shifts linearly toward the negative direction with increasing solution pH. The surface coverage of Celestine blue immobilized on CNTs glassy carbon electrode was approximately 1.95×10−10 mol cm−2. The charge transfer coefficient (α) and heterogeneous electron transfer rate constants (ks) for GC/MWCNTs/Celestine blue were 0.43 and 1.26 s−1, respectively. The modified electrode show strong catalytic effect for reduction of hydrogen peroxide and oxygen at reduced overpotential. The glucose biosensor was fabricated by covering a thin film of sol‐gel composite containing glucose oxides (GOx) on the surface of Celestine blue /MWCNTs modified GC electrode. The biosensor can be used successfully for selective detection of glucose based on the decreasing of cathodic peak current of oxygen. The detection limit, sensitivity and liner calibration rang were 0.3 μM, 18.3 μA/mM and 10 μM–6.0 mM, respectively. The accuracy of the biosensor for glucose detection was evaluated by detection of glucose in a serum sample, using standard addition protocol. In addition biosensor can reach 90% of steady currents in about 3.0 sec and interference effect of the electroactive existing species (ascorbic acid–uric acid and acetaminophen) was eliminated. Furthermore, the apparent Michaelis–Menten constant 2.4 mM, of GOx on the nano composite exhibits excellent bioelectrocatalytic activity of immobilized enzyme toward glucose oxidation. Excellent electrochemical reversibility of redox couple, high stability, technically simple and possibility of preparation at short period of time are of great advantages of this procedure for modification of glucose biosensor.
An efficient and accurate non‐hydrostatic model with embedded Boussinesq‐type like equations for surface wave modeling
Authors: Young Chih‐Chieh , Wu Chin H.
Published: August 2008

A novel approach that embeds the Boussinesq‐type like equations into an implicit non‐hydrostatic model (NHM) is developed. Instead of using an integration approach, Boussinesq‐type like equations with a reference velocity under a virtual grid system are introduced to analytically obtain an analytical form of pressure distribution at the top layer. To determine the size of vertical layers in the model, a top‐layer control technique is proposed and the reference location is employed to optimize linear wave dispersion property. The efficiency and accuracy of this NHM with Boussinesq‐type like equations (NHM‐BTE) are critically examined through four free‐surface wave examples. Overall model results show that NHM‐BTE using only two vertical layers is capable of accurately simulating highly dispersive wave motion and wave transformation over irregular bathymetry. Copyright © 2008 John Wiley & Sons, Ltd.
A dual‐time central difference finite volume scheme for interface capturing on unstructured meshes
Authors: Gough H. , Gaitonde Ann L. , Jones D. P.
Published: August 2008

This paper describes a central difference scheme for the prediction of flows with an interface. The interface is captured rather than tracked and the key to the current approach is a correction to the hydrostatic pressure. The correction enables the scheme to evaluate pressures at cell faces in a consistent manner so that the source term in the equations is correctly balanced at the interface and on non‐equispaced meshes. This prevents the development of large errors in the solution, which can lead to the divergence of the numerical scheme. The current approach allows interface flows to be calculated by a simple modification of existing central difference codes. Results for a number of test cases are presented, with comparisons made with both experimental data and other numerical solutions. Copyright © 2008 John Wiley & Sons, Ltd.
Differential contribution of dorsal and ventral hippocampus to trace and delay fear conditioning
Authors: Esclassan Frederic , Coutureau Etienne , Di Scala Georges , Marchand Alain R.
Published: August 2008

Trace conditioning relies on the maintained representation of a stimulus across a trace interval, and may involve a persistent trace of the conditioned stimulus (CS) and/or a contribution of contextual conditioning. The role of hippocampal structures in these two types of conditioning was studied by means of pretraining lesions and reversible inactivation of the hippocampus in rats. Similar levels of conditioning to a tone CS and to the context were obtained with a trace interval of 30 s. Neurotoxic lesions of the whole hippocampus or reversible muscimol inactivation of the ventral hippocampus impaired both contextual and tone freezing in both trace‐ and delay‐conditioned rats. Dorsal hippocampal injections impaired contextual freezing and trace conditioning, but not delay conditioning. No dissociation between trace and contextual conditioning was observed under any of these conditions. Altogether, these data indicate that the ventral and dorsal parts of the hippocampus compute different aspects of trace conditioning, with the ventral hippocampus being involved in fear and anxiety processes, and the dorsal hippocampus in the temporal and contextual aspects of event representation. © 2008 Wiley‐Liss, Inc.
A novel scaffold based on formation and agglomeration of PCL microbeads by freeze‐drying
Authors: Gerçek I. , Tıǧlı R. S. , Gümüşderelioǧlu M.
Published: August 2008

Polycaprolactone (PCL) scaffolds were prepared by freeze‐drying of polymer solutions in tetrahydrofuran. Effects of the polymer composition, which is 10 and 20% (w/v), on the scaffold properties for example, morphology, porosity, mechanical stability, degradability, and so forth were investigated by using suitable methods. Scanning electron microscopy photographs clearly showed the presence of a porous, three‐dimensional structure including agglomerated PCL microspheres. Porosity analysis demonstrated that 10 and 20% (w/v) scaffolds have 95.9% and 74.4% porosity, respectively. The microspheres have very narrow size distribution and their diameters increase from 50–70 μm to 90–100 μm with increasing PCL content from 10 to 20% (w/v). The microspheres were highly connected with each other and the scaffolds have superior mechanical properties when compared with the traditional PCL scaffolds. Cell culture experiments showed that periodontal ligament cells (PDL) were able to attach and proliferate on the 20% PCL scaffold. The results demonstrated that this novel PCL structure will be a potential tissue engineering scaffold with its superior properties and simple preparation procedure. © 2007 Wiley Periodicals, Inc. JBiomed Mater Res, 2008
The problematic importance of hypotheses
Authors: Rozeboom Wm. W.
Published: August 2008

Contrary to what seems to have become established dogma in the behavioral sciences, the confirmational relevance of some data possibility D to a conjecture H should be indifferent to which of these two prospects we think of first. In particular, if ascertaining whether D is true would be a hypothetico‐deductive test of hypothesis H were D's implication by H declared at outset, the confirmational relevance of D to H is not diminished by learning D before becoming aware that H implies it. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64: 1109–1127, 2008.
PERK is essential for neonatal skeletal development to regulate osteoblast proliferation and differentiation
Authors: Wei Jianwen , Sheng Xiaoyi , Feng Daorong , McGrath Barbara , Cavener Douglas R.
Published: August 2008

Loss of function mutations of Perk (eukaryotic translation initiation factor 2 alpha kinase 3) in humans and mice cause severe neonatal developmental defects, including diabetes, growth retardation and multiple skeletal dysplasias. Comprehensive analyses on bone tissue, at the cellular and molecular level in PERK‐deficient mice demonstrated that neonatal Perk−/− mice are severely osteopenic, which is caused by a deficiency in the number of mature osteoblasts, impaired osteoblast differentiation, and reduced type I collagen secretion. Impaired differentiation of osteoblasts in Perk KO mice was associated with decreased expression of Runx2 and Osterix, key regulators of osteoblast development. Reduced cell proliferation and reduced expression of key cell cycle factors including cyclin D, cyclin E, cyclin A, Cdc2, and CDK2 occur in parallel with the differentiation defect in mutant osteoblasts. In addition, the trafficking and secretion of type I collagen is compromised as manifested by abnormal retention of procollagen I in the endoplasmic reticulum, and reduced mature collagen production and mineralization. Taken together, these studies identify PERK as a novel regulator of skeletal development and osteoblast biology. J. Cell. Physiol. 217: 693–707, 2008. © 2008 Wiley‐Liss, Inc.
Regulation of the friction coefficient of articular cartilage by TGF‐β1 and IL‐1β
Authors: DuRaine Grayson , Neu Corey P. , Chan Stephanie M.T. , Komvopoulos Kyriakos , June Ronald K. , Reddi A. Hari
Published: August 2008

Articular cartilage functions to provide a low‐friction surface for joint movement for many decades of life. Superficial zone protein (SZP) is a glycoprotein secreted by chondrocytes in the superficial layer of articular cartilage that contributes to effective boundary lubrication. In both cell and explant cultures, TGF‐β1 and IL‐1β have been demonstrated to, respectively, upregulate and downregulate SZP protein levels. It was hypothesized that the friction coefficient of articular cartilage could also be modulated by these cytokines through SZP regulation. The friction coefficient between cartilage explants (both untreated and treated with TGF‐β1 or IL‐1β) and a smooth glass surface due to sliding in the boundary lubrication regime was measured with a pin‐on‐disk tribometer. SZP was quantified using an enzyme‐linked immunosorbant assay and localized by immunohistochemistry. Both TGF‐β1 and IL‐1β treatments resulted in the decrease of the friction coefficient of articular cartilage in a location‐ and time‐dependent manner. Changes in the friction coefficient due to the TGF‐β1 treatment corresponded to increased depth of SZP staining within the superficial zone, while friction coefficient changes due to the IL‐1β treatment were independent of SZP depth of staining. However, the changes induced by the IL‐1β treatment corresponded to changes in surface roughness, determined from the analysis of surface images obtained with an atomic force microscope. These findings demonstrate that the low friction of articular cartilage can be modified by TGF‐β1 and IL‐1β treatment and that the friction coefficient depends on multiple factors, including SZP localization and surface roughness. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:249–256, 2009
From streaming‐potentials to shear stress: 25 years of bone cell mechanotransduction
Authors: Riddle Ryan C. , Donahue Henry J.
Published: August 2008

Mechanical loads are vital regulators of skeletal mass and architecture as evidenced by the increase in bone formation following the addition of exogenous loads and loss of bone mass following their removal. While our understanding of the molecular mechanisms by which bone cells perceive changes in their mechanical environment has increased rapidly in recent years, much remains to be learned. Here, we outline the effects of interstitial fluid flow, a potent biophysical signal induced by the deformation of skeletal tissue in response to applied loads, on bone cell behavior. We focus on the molecular mechanisms by which bone cells are hypothesized to perceive interstitial fluid flow, the cell signaling cascades activated by fluid flow, and the use of this signal in tissue engineering protocols. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:143–149, 2009
TNF‐α–induced NF‐κB signaling reverses age‐related declines in VEGF induction and angiogenic activity in intervertebral disc tissues
Authors: Ohba Tetsuro , Haro Hirotaka , Ando Takashi , Wako Masanori , Suenaga Fumiko , Aso Yoshinori , Koyama Kensuke , Hamada Yoshiki , Nakao Atsuhito
Published: August 2008

We previously demonstrated that VEGF and its receptors were expressed in human herniated discs (HD). TNF‐α induced VEGF, resulting in neovascularization of disc tissues in a model of HD. The goal of the current research was to investigate the precise role of TNF‐α–induced VEGF and the mechanism of angiogenesis in disc tissues. We performed ELISAs, Western blots, and immunohistological examinations to assess the role of TNF‐α–induced VEGF using organ disc cultures with wild type, TNF receptor 1‐null (TNF‐RInull), or TNF receptor 2‐null (TNF‐RIInull) mice. VEGF induction was inhibited when we used TNF‐RInull‐derived disc tissues. NF‐κB pathway inhibitors also strongly suppressed VEGF induction. Thus, TNF‐α induced VEGF expression in disc cells primarily through the NF‐κB pathway. In addition, VEGF immunoreactivity was detected predominantly in annulus fibrosus cells and increased after TNF‐α stimulation. TNF‐α treatment also resulted in CD31 expression on endothelial cells and formation of an anastomosing network. In contrast, angiogenic activity was strongly inhibited in the presence of NF‐κB inhibitors or anti‐VEGF antibody. Our data show angiogenesis activity in disc tissues is regulated by VEGF and the NF‐κB pathway, both of which are induced by TNF‐α. The level of angiogenic activity in disc tissues was closely related to aging. Because neovascularization of HD is indispensable for HD resorption, the prognosis of HD and the rate of the resorption process in patients may vary as a function of the patient's age. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:229–235, 2009
Subcutaneous‐induced membranes have no osteoinductive effect on macroporous HA‐TCP in vivo
Authors: Catros Sylvain , Zwetyenga Narcisse , Bareille Reine , Brouillaud Brigitte , Renard Martine , Amédée Joelle , Fricain Jean‐Christophe
Published: August 2008

Induced Membranes Technique was first described to enhance bone reconstruction of large osseous defects. Previous in vitro studies established their osteoinductive potential, due to the presence of opteoblasts precursors and to high amounts of growth factors contained within. The purpose of this study was to test in vivo the osteoinductive properties of induced membranes on a macroporous HA‐TCP in a nonosseous subcutaneous site. Subcutaneous‐induced membranes were obtained in 21 rabbits; 1 month later, the membranes were filled with a biphasic calcium phosphate material composed of 75% hydroxyapatite (HA) and 25% β‐tricalcium phosphate associated or not with autograft. Histological and immunohistochemical studies were performed on membrane biopsies. Undecalcified and decalcified sections were qualitatively and quantitatively analyzed. 45Ca uptake was observed and quantified on the sections using microimager analysis. Dense vascularity was found in the induced membranes. New bone formation was detected in the HA‐TCP + autograft samples and increased significantly from 3 to 6 months (p < 0.05). No bone was detected in the biomaterial graft alone in the induced membranes at any time. This study showed that induced membranes placed in a nonosseous site have no osteoinductive properties on a macroporous biphasic calcium phosphate biomaterial. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:155–161, 2009
Does the preoperative imaging of perforators with CT angiography improve operative outcomes in breast reconstruction?
Authors: Rozen Warren M. , Anavekar Namrata S. , Ashton Mark W. , Stella Damien L. , Grinsell Damien , Bloom Richard J. , Taylor G. Ian
Published: August 2008

Background: Breast reconstruction is increasingly performed with the use of the abdominal wall donor site, with potential complications including donor site morbidity and impaired flap viability. As a tool for selecting the optimal perforators which will ultimately supply the flap, preoperative imaging with computed tomography angiography (CTA) has become increasingly popular. Potential benefits include reduced intramuscular dissection, with faster and safer dissection, reduced donor site morbidity and improved flap vascularity and survival. Despite the potential for improvements in operative outcome, any benefits are yet to be established. Methods: A cohort study of 104 breast reconstructions in 88 patients was conducted. All patients underwent breast reconstruction based on an abdominal wall free flap. Of these, 40 patients undergoing preoperative imaging with CTA and 48 patients not undergoing CTA were included, with all CTAs undertaken at a single institution. Length of operation, length of stay, and operative complications were assessed. An evaluation of operative stress was achieved with the use of visual analogue scales (VAS) administered to the surgeons. Results: The use of CTA was associated with decreased operating time (mean: 77 min for bilateral cases), significantly decreased complications related to flap viability (particularly partial flap loss), and a statistically significant reduction in donor site morbidity. Psychometric testing of surgeons revealed a statistically significant decrease in operative stress (41% decrease) with the use of preoperative CTA. Conclusion: The use of CTA for preoperative imaging in breast reconstruction is associated with improved operative outcomes. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Usefulness of vascular bundle interposition of the descending branch of the lateral circumflex femoral vessels for free flap reconstruction of the calvarial defect
Authors: Sano Kazufumi , Okuda Takahisa , Aoki Ritsu , Kimura Kazumasa , Ozeki Satoru
Published: August 2008

Usefulness of the descending branch of the lateral circumflex femoral vessels as a vascular bundle interposition graft was introduced. Large calvarial defect with no recipient vessel for direct anastomosis was successfully covered with free flap nourished by the cervical vessels through the vascular bundle interposition graft of the descending branch of the lateral circumflex femoral artery and its venae comitantes. The vascular bundle interposition has remarkable advantages over the venous graft regarding its patency and durability, especially in the head and neck region in which grafted vessels is difficult to be set on the straight. The descending branch of the lateral circumflex femoral vessels can be harvested up to 20 cm, and its diameter is suitable for interposition between conventional free flaps and recipient vessels in the head and neck region. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Stabilization of microvascular pedicles in intricate locations using fibrin glue
Authors: Schwabegger Anton H. , Engelhardt Timm O. , Jeschke Johannes
Published: August 2008

In reconstructive microsurgery, it is occasionally advantageous to use long recipient or donor vessels for optimal flap inset. These long vessels are prone to kinking or torsion along their longitudinal axis from vessel distension during blood inflow and rising blood pressure. More often than arteries, the veins can also be compressed by overlying tissue sutured under tension or by developing edema. Reanastomosis can no longer be feasible or desirable for several reasons, and the elongated vessels may have to be shifted to a curved course. To avoid detrimental kinking or torsion, fibrin glue can be administered along this new vessel course in order to ensure stabilization. In 20 such cases, we successfully avoided complications when the danger of kinking, torsion, or vein compression was evident after successful anastomosis. On the basis of this experience, we recommend the use of fibrin glue in microsurgical procedures, especially for vessels in intricate geometrical locations. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Sensory outcome of fingertip replantations without nerve repair
Authors: Ozcelik Ismail Bulent , Tuncer Serdar , Purisa Husrev , Sezer Ilker , Mersa Berkan , Kabakas Fatih , Celikdelen Pinar
Published: August 2008

The sensory recovery outcomes of fingertip replantations without nerve repair were retrospectively studied. Between 2000 and 2006, 112 fingertip replantations with only arterial repair were carried out in 98 patients. About 76 of the replants survived totally, with a success rate of 67.8%. Evaluation of sensory recovery was possible in 31 patients (38 replantations). Sensory evaluation was made with Semmes–Weinstein, static and dynamic two‐point discrimination, and vibration sense tests. Fingertip atrophy, nail deformities, and return to work were also evaluated. According to the Semmes–Weinstein test, 29.0% (11/38) of the fingers had normal sense, 60.5% (23/38) had diminished light touch, 7.9% (3/38) had diminished protective sensation, and 2.6% (1/38) had loss of protective sensation. Mean static and dynamic two‐point discriminations were 7.2 mm (3–11 mm), and 4.60 mm (3–6 mm), respectively. Vibratory testing revealed increased vibration in 42.1% of the fingers, decreased vibration in 36.8%, and equal vibration when compared with the non‐injured fingers in 21.1%. Atrophy was present in 14 (36.8%) fingers and negatively affected the results. Nail deformities, cold intolerance, return to work, and the effect of sensory education were investigated. Comparison of crush and clean cut injuries did not yield any significant difference in any of the parameters. Patients who received sensory education had significantly better results in sensory testing. The results were classified as excellent, good, and poor based on results of two‐point discrimination tests. The outcome was excellent in 18 fingers and good in 20 fingers. Overall, satisfactory sensory recovery was achieved in fingertip replantations without nerve repair. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Vibration testing for anomaly detection
Authors: Ammari Habib , Kang Hyeonbae , Kim Eunjoo , Lee Hyundae
Published: August 2008

In this paper we propose an efficient method to reconstruct a small inclusion buried inside a body using the perturbation of modal parameters measured on the boundary of the body. We design a reconstruction algorithm based on the asymptotic expansions of the eigenvalue perturbations obtained by Ammari and Moskow (Math. Meth. Appl. Sci. 2003; 26:67–75). We then implement this algorithm and demonstrate its viability and limitations. Copyright © 2008 John Wiley & Sons, Ltd.
Structure theorems for associated homogeneous distributions based on the line
Authors: Franssens Ghislain R.
Published: August 2008

Associated homogeneous distributions (AHDs) with support in the line R are the distributional generalizations of one‐dimensional power‐log functions. In this paper, we derive a number of practical structure theorems for AHDs based on R and being complex analytic with respect to their degree of homogeneity in some region of the complex plane. Each theorem gives a representation that is designed to have a distinct advantage for calculating either convolution products, multiplication products, generalized derivatives and primitives, Fourier transforms or Hilbert transforms of AHDs. Copyright © 2008 John Wiley & Sons, Ltd.
Longtime behavior for a nonlinear wave equation arising in elasto‐plastic flow
Authors: Zhijian Yang
Published: August 2008

The paper studies the longtime behavior of solutions to the initial boundary value problem (IBVP) for a nonlinear wave equation arising in elasto‐plastic flow utt−div{|∇u|m−1∇u}−λΔut+Δ2u+g(u)=f(x). It proves that under rather mild conditions, the dynamical system associated with above‐mentioned IBVP possesses a global attractor, which is connected and has finite Hausdorff and fractal dimension in the phase spaces X1=H(Ω) × L2(Ω) and X=(H3(Ω)∩H(Ω)) × H(Ω), respectively. Copyright © 2008 John Wiley & Sons, Ltd.
Stabilization by vertical vibrations
Authors: Núñez Daniel , Torres Pedro J.
Published: August 2008

We consider a general version of the classical problem of the stabilization of the inverted pendulum by a vertical periodic vibration of the point of suspension. Instead of the usual harmonic motion, we propose an oscillatory control with a piecewise‐constant acceleration, obtaining explicit conditions over the frequency or the amplitude leading to the desired stabilization. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of selenium status and supplementation with high‐selenium yeast on plasma homocysteine and B vitamin concentrations in the UK elderly
Authors: Bekaert Bram , Cooper Matthew L. , Green Fiona R. , McNulty Helene , Pentieva Kristina , Scott John M. , Molloy Anne M. , Rayman Margaret P.
Published: August 2008

The level of plasma total homocysteine (tHcy), long known to be B vitamin dependent, has recently been shown to be inversely associated with plasma selenium (Se) concentration in human subjects. We therefore, chose to investigate the interaction between Se, tHcy and B vitamins in a double‐blind, placebo‐controlled trial where 501 healthy UK elderly volunteers were randomly allocated to receive 100, 200, or 300 μg Se/day as high‐Se‐yeast, or placebo‐yeast for 6 months. Plasma Se, tHcy, folate, vitamin B‐12, pyridoxal‐5′‐phosphate (PLP) and its catabolite, 4‐pyridoxic acid, were measured in all participants at baseline and in samples from the placebo, 100 and 300 μg Se/day groups, at follow‐up. At baseline, Se was inversely correlated with tHcy but only in males (p< 0.001). Before supplementation, tHcy concentration was significantly lower in the highest compared to the lowest Se tertile in males (p< 0.05), and in females when folate concentrations were also in the top tertile (p< 0.05). The effect of folate, PLP and vitamin B‐12 concentrations on plasma tHcy correlated with Se concentration at baseline. After 6 months of Se supplementation, only Se concentration had changed significantly. Supplementation with Se does not affect tHcy concentration in the UK elderly population.
In vitro growth inhibition of mouse mammary epithelial tumor cells by methylseleninic acid: Involvement of protein kinases
Authors: Singh Uma , Null Kevin , Sinha Raghu
Published: August 2008

Methylseleninic acid (MSeA) is a synthetic organoselenium form known to be effective against mammary carcinogenesis in vivo. Using the synchronized mouse mammary epithelial tumor cell (TM6) model, we have previously shown that 5 μM MSeA significantly inhibits cell growth and induces a reversible growth arrest in the G1 phase. In the present study, we examined the effects of MSeA on Rb, cyclin dependent kinase 2 (cdk2), cdk4, cyclin E and cyclin D1. Growth arrest of cells was accompanied by a reduction in total cdk2 kinase and cyclin E‐associated cdk2 kinase activities. The p27 levels associated with cdk2 were elevated during the cell cycle. In addition, growth inhibition correlated with a relative increase in the hypophosphorylated form of Rb in MSeA‐treated cells and Egr1 was elevated in MSeA‐treated cells. The KinetworksTM Protein Kinase Screen (KPKS 1.0) was used to examine 75 protein kinases. MSeA treatment resulted in differential expression of several protein–serine/threonine kinases, protein–tyrosine kinases and protein–threonine/tyrosine kinases. Some of these kinases are being reported for the first time as being altered by MSeA. The outcome of these experiments will be of significance since these kinases are known to be involved in survival and/or apoptotic pathways of tumor cells.
Genistein‐ and daidzein 7‐O‐β‐D‐glucuronic acid retain the ability to inhibit copper‐mediated lipid oxidation of low density lipoprotein
Authors: Kgomotso Tiny , Chiu Francis , Ng Ken
Published: August 2008

Two isoflavones in vivo metabolites, genistein‐7‐O‐β‐D‐glucuronic acid (G7G) and daidzein‐7‐O‐β‐D‐glucuronic acid (D7G) were synthesised chemically. The ability of these metabolites to scavenge an organic radical was measured by the trolox equivalent antioxidant capacity (TEAC) assay, while their reducing ability was measured by the ferric reducing antioxidant power (FRAP) assay. The TEAC and FRAP values of G7G were 45 and 51% of that of genistein, while those of D7G were 52 and 77% of that of daidzein, respectively. A direct assessment of G7G and D7G antioxidant activity by their ability to delay copper(II)‐mediated lipid oxidation of human LDL showed that these metabolites retained the ability to prevent oxidation in the lipid phase, but activity was diminished compared to their corresponding aglycones. However, G7G and D7G also decreased the rate of lipid oxidation to 53 and 86% of control without isoflavones, respectively, indicating a continuous exchange of antioxidants between the aqueous environment and the LDL lipid phase during the whole oxidation period.
Improvements for the visualization of low‐molecular weight protein and peptides of human tears using MALDI
Authors: Nguyen‐Khuong Terry , Fitzgerald Anna , Zhao Zhejun , Willcox Mark , Walsh Bradley J.
Published: August 2008

Many low‐molecular weight proteins and peptides in human tears are potentially bioactive proteins but the range and number of these is yet to be fully characterized. A number of different sample preparation techniques were used to maximize the visualization of peptides from reflex tears. Samples were pretreated using precipitation and filtration techniques prior to analyses using MALDI‐TOF MS. Peptides were searched for between 700 to 4000 m/z. Sample dilution in several different buffer systems followed by filtration with a 30‐kDa cutoff filter and C18 reverse phase microcolumn purification produced significantly (p = 0.049) more peaks in tears than other methods used to prepare tears prior to MALDI‐TOF MS. This study has established a technique for optimizing the visualization of naturally occurring peptides in tears.
Lipolytic and esterolytic activity‐based profiling of murine liver
Authors: Birner‐Gruenberger Ruth , Susani‐Etzerodt Heidrun , Kollroser Manfred , Rechberger Gerald N. , Hermetter Albin
Published: August 2008

In lipid metabolism, the liver acts as a buffer for transient energy fluctuations. It temporarily stores fatty acids as triacylglycerol and secretes them as very low density lipoprotein into the circulation when the period of maximum lipid load has passed. The lipolytic enzymes responsible for mobilization of internal lipid stores in the liver have not been identified yet. We introduced active site‐directed chemical probes for lipolytic activity profiling in complex mixtures, known as activity‐based proteomics, and employed it for global analysis and functional annotation of lipolytic proteins in mouse adipose tissue. Here we report the combined application of two approaches using fluorescent and biotinylated probes for discovery and discrimination of lipolytic and esterolytic enzymes in mouse liver subproteomes. Proteomes labeled with the fluorescent probes were analyzed by 2‐DE while proteomes labeled with the biotinylated probe were subjected to avidin‐affinity isolation. Of 37 totally identified proteins, 15 were detected using both approaches while 14 and 8 were solely identified by 2‐DE and avidin‐affinity isolation, respectively. Moreover, 12 enzymes were classified as potential lipases and/or cholesteryl esterases by their reaction with probes specific for the respective activities directly in their proteomes.
Mountain permafrost on active volcanoes: field data and statistical mapping, Klyuchevskaya volcano group, Kamchatka, Russia
Authors: Abramov A. , Gruber S. , Gilichinsky D.
Published: August 2008

Permafrost is widespread in mountainous volcanic areas of the Kamchatka Peninsula. In this paper, we describe geocryological conditions (active layer depths, permafrost temperatures, ground thermal properties and cryostratigraphy) in the Klyuchevskaya volcano group and estimate the spatial distribution of permafrost using a simple statistical model. Measured mean annual ground temperatures (MAGTs) vary from near 0°C around 950 m a.s.l. to −7°C at 2500 m a.s.l. and permafrost is predicted to occur at elevations >∼700 m a.s.l. Heat transfer modelling indicates that the maximum permafrost thickness is about 1000 m for the highest summits (∼5000 m a.s.l.). Copyright © 2008 John Wiley & Sons, Ltd.
Temperature and moisture trends in non‐sorted earth hummocks and stripes on the Old Man Range, New Zealand: implications for mechanisms of maintenance
Authors: Scott Matthew B. , Dickinson Katharine J. M. , Barratt Barbara I. P. , Sinclair Brent J.
Published: August 2008

The mechanisms of maintenance of earth hummocks and non‐sorted stripes in seasonally frozen ground on the Old Man Range, Otago, New Zealand were investigated. These landforms are hypothesised to be active periglacial landforms maintained by seasonal movement of moisture down an energy gradient. We tested three hypotheses: 1) freezing should occur predominantly in the crests of the stripes and hummocks; 2) differential freezing patterns should be consistent between years; and 3) in the presence of a temperature gradient (i.e. in winter), soil moisture content should be greater in crests than in furrows. An array of 39 thermistors at each of two sites was used to monitor soil temperature gradients during three winters, and replicate soil cores were taken in autumn and winter to determine soil moisture gradients. Freezing occurred mainly in the crests and sides (heavily influenced by aspect), and patterns of freezing showed strong interannual consistency, supporting our first two hypotheses. Soil in crests had a higher moisture content in both freezing and thawed seasons, which was inconclusive relative to the expected water gradient. Copyright © 2008 John Wiley & Sons, Ltd.
Molecular dynamic simulations of nanomechanic chaperone peptide and effects of in silico His mutations on nanostructured function
Authors: Barzegar Abolfazl , Moosavi‐Movahedi Ali Akbar , Mahnam Karim , Bahrami Homayoon , Sheibani Nader
Published: August 2008

The nanoscale peptide YSGVCHTDLHAWHGDWPLPVK exhibits molecular chaperone activity and prevents protein aggregation under chemical and/or thermal stress. Here, His mutations of this peptide and their impact on chaperone activity were evaluated using theoretical techniques. Molecular dynamic (MD) simulations with simulated annealing (SA) of different mutant nanopeptides were employed to determine the contribution of the scaffolding His residues (H45, H49, H52), when mutated to Pro, on chaperone action in vitro. The in silico mutations of His residues to Pro (H45P, H49P, H52P) revealed loss of secondary ordered strand structure. However, a small part of the strand conformation was formed in the middle region of the native chaperone peptide. The His‐to‐Pro mutations resulted in decreased gyration radius (Rg) values and surface accessibility of the mutant peptides under the simulation times. The invariant dihedral angle (ϕ) values and the disrupting effects of the Pro residues indicated the coil conformation of mutant peptides. The failure of the chaperone‐like action in the Pro mutant peptides was consistent with their decreased effective accessible surfaces. The high variation of Φ value for His residues in native chaperone peptide leads to high flexibility, such as a minichaperone acting as a nanomachine at the molecular level. Our findings demonstrate that the peptide strand conformation motif with high flexibility at nanoscale is critical for chaperone activity. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Estimating observation impact without adjoint model in an ensemble Kalman filter
Authors: Liu Junjie , Kalnay Eugenia
Published: August 2008

We propose an ensemble sensitivity method to calculate observation impacts similar to Langland and Baker (2004) but without the need for an adjoint model, which is not always available for numerical weather prediction models. The formulation is tested on the Lorenz 40‐variable model, and the results show that the observation impact estimated from the ensemble sensitivity method is similar to that from the adjoint method. Like the adjoint method, the ensemble sensitivity method is able to detect observations that have large random errors or biases. This sensitivity could be routinely calculated in an ensemble Kalman filter, thus providing a powerful tool to monitor the quality of observations and give quantitative estimations of observation impact on the forecasts. Copyright © 2008 Royal Meteorological Society
Theoretical study of the SH···O blue‐shifted hydrogen bond
Authors: Yang Yong
Published: August 2008

Theoretical calculations were performed to study the nature of the hydrogen bonds in the complexes HCHO···HSO, HCOOH···HSO, HCHO···HOO, and HCOOH···HOO. The geometric structures and vibrational frequencies of these four complexes at the MP2/6‐31G(d,p) and MP2/6‐311+G(d,p) levels are calculated by standard and counterpoise‐corrected methods, respectively. The results indicate that in the complexes HCHO···HSO and HCOOH···HSO the SH bond is strongly contracted. In the SH···O hydrogen bonds, the calculated blue shifts for the SH stretching frequencies are in the vicinity of 50 cm−1. While in the complexes HCHO···HOO and HCOOH···HOO, the OH bond is elongated and OH···O red‐shifted hydrogen bonds are found. From the natural bond orbital analysis it can be seen that the XH bond length in the XH···Y hydrogen bond is controlled by a balance of four main factors in the opposite directions: hyperconjugation, electron density redistribution, rehybridization, and structural reorganization. Among them hyperconjugation has the effect of elongating the XH bond. Electron density redistribution and rehybridization belong to the bond shortening effects, while structural reorganization has an uncertain influence on the XH bond length. In the complexes HCHO···HSO and HCOOH···HSO, the shortening effects dominate which lead to the blue shift of the SH stretching frequencies. In the complexes HCHO···HOO and HCOOH···HOO where elongating effects are dominant, the OH···O hydrogen bonds are red‐shifted. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Reconstruction of the (011) surface on α‐quartz: A semiclassical Ab initio molecular dynamics study
Authors: Lopes Pedro E. M. , Demchuk Eugene , Mackerell Alexander D.
Published: August 2008

Ab initio molecular dynamics simulations have been performed on the (011) surface of α‐quartz at room‐temperature using density functional theory. Pristine surface was obtained by homolytic fracture of α‐quartz crystal, leaving exposed SiO· radicals, following which the surface was allowed to spontaneously reconstruct during the simulation. Reconstruction events occurred at different timings but in most cases produced similar geometries. The most common motif consisted of a fused seven‐member ring. Formation of this structure proceeded through reaction of two adjacent O· radicals, followed by linking of one of the reactive O· with a nearby silicon. Other structures, like Si2O2, were also observed. In the newly formed structures some of the silicon atoms had pentacoordinated geometry, usually distorted between pure bipyramidal, trigonal, and square pyramidal. In a few cases oxygen atoms also became tricoordinated. Formation of new bonds was investigated by analyzing the electronic structure of the system along the reaction path, and specifically the localization of unpaired electrons was deduced from the spin‐density. Because most reactions involved triplet → singlet transitions, a time‐dependent density functional theory was used to determine the crossing point of the two potential energy surfaces. Plotted density of states was also used to compare the electronic structures of the initial and reconstructed surfaces. Reconstruction originated new states from O‐px and O‐pz orbitals. Stability analysis of the reconstructed surface was performed at the PBE level and 7‐member rings were found to be more stable than fused rings with pentacoordinated silicon. Hypervalent silicon and oxygen atoms were also found to exist. Nevertheless, specialization of (011) surface appears to be less reactive compared to (001), which suggests a lesser toxicity of rhombohedral form on crystalline silica. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
π‐π Stacking of curved carbon networks: The corannulene dimer
Authors: Sygula Andrzej , Saebø Svein
Published: August 2008

Dimers of corannulene, a curved, saucer shaped molecule, were studied by theoretical calculations using second order Møller‐Plesset perturbation theory and a large polarized triple zeta basis set. Three dimer motifs were investigated: the “native” dimer is the concave‐convex stacking of two monomers with the geometries of both monomers conserved; the “planar” motif with both monomers forced to be planar; and the “C60‐like” dimer where the outer monomer has the native geometry while the inner one has the curvature of buckminsterfullerene C60. Both staggered and eclipsed conformations of the dimers were investigated. Our calculations show that the binding energy of the native concave‐convex corannulene dimer is quite substantial (17.2 kcal/mole at the “best” SCS‐MP2/cc‐pvtz level of theory) with an equilibrium distance of about 3.64 Å. Surprisingly, there are only minor differences in both binding energies and equilibrium distances between the three different dimer motifs. This suggests that the curvature of the conjugated carbon networks does not disable their ability to form π‐π stacked assemblies similar to the planar systems. However, in contrast to the planar systems, at least part of the binding energies in the stacked curved systems can be attributed to attractive electrostatic dipole‐dipole contributions since buckybowls exhibit significant dipole moments. For the “planar” dimer, a staggered arrangement of the two monomers is preferred, while eclipsed conformations are the most stable for all curved dimers. For all systems, the basis set superposition errors are large (ca. 7 kcal/mol) at the equilibrium distance even with our largest basis sets. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Decomposition mechanisms of dinitrotoluene
Authors: Tanaka Genzo , Weatherford Charles
Published: August 2008

To develop a viable detection system for 2,4‐dinitrotoluene (DNT), its unimolecular decomposition mechanisms were studied by using the density functional theory. Three decomposition mechanisms were investigated: (1) homolytic cleavage; (2) migration of one of the O atoms in the NO2 groups to its neighboring C atoms; (3) migration of one of the H atoms in the methyl group to a neighboring O atom in the NO2 group. Only homolytic cleavage of the CN bond yields NO2 radicals with a total energy of 61 kcal/mol or more. Initial migration of the O atom to its second‐nearest‐neighbor C atom requires about 56 kcal/mol, but subsequent homolysis produces NO fragments with less energy ∼15 kcal/mol. NO formation from both NO2 groups in 2,4‐DNT is possible with a total energy of ∼63 kcal/mol. The H‐migration has the lowest energy barrier of 39 kcal/mol among the three initial decomposition mechanisms. Removing O directly from 2,4‐DNT requires ∼90 kcal/mol, while NO2 radical decomposes to NO and O with ∼73 kcal/mol. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008