bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anatomic study of distally based pedicle compound flaps with nutrient vessels of the cutaneous nerves and superficial veins of the forearm
Authors: Zhang Fa‐Hui , Topp Shelby G. , Zhang Wen‐Ju , Zheng He‐Ping , Zhang Feng 
Published: June 2006

AbstractThe purpose of this study was to describe the anatomic basis for a distally based neurovenovascular pedicle compound flap, with nutrient vessels of the cutaneous nerves and superficial veins of the forearm. In this study, the origins, branches, and anastomoses of nutrient vessels of the cutaneous nerves and superficial veins of the forearm and their relationships with the blood supply of adjacent muscle, bone, and skin were assessed in 96 adult cadavers by perfusion of red gelatin into the superior limb arteries. The results showed that the nutrient vessels of cutaneous nerves and superficial veins of the forearm were found to have multiple origins, consisting of six longitudinal vascular plexuses and one transverse vascular plexus of the forearm, as follows: 1) the anterior‐lateral vascular plexus from cutaneous branches of the radial artery; 2) the anterior‐medialis vascular plexus from cutaneous branches of the ulnar artery; 3) the dorso‐lateral vascular plexus from radial osteal and cutaneous branches; 4) the dorso‐medialis vascular plexus from ulnar osteal and cutaneous branches; 5) the radial vascular plexus from osteal and cutaneous branches of the radial artery, cutaneous branches of the radial artery in the upper wrist, recurrent branches of the styloid process of the radius, and the radialis vascular plexus of cutaneous branches of the tabatière anatomique (anatomical snuffbox); and 6) the ulnar lateral vascular plexus from cutaneous branches of the ulnar artery in the upper wrist and osteal and cutaneous branches. The transverse vascular plexus is composed of dorsal branches of the ulnar and radial arteries. These perforating branches give fascial branches, cutaneous branches, periosteal branches, and nutrient vessels of cutaneous nerves and superficial veins. These results suggest that nutrient vessels of the cutaneous nerves and superficial veins of the forearm have the same origins as those of the nutrient vessels of adjacent muscles, bones, and skin of the forearm, which can be designated as five types of distally based pedicle flaps with nutrient vessels of cutaneous nerves and superficial veins of the forearm, whose rotation point is at the wrist joint. This flap can be applied to repair tissues of distal parts of the hand. © 2006 Wiley‐Liss, Inc. Microsurgery, 2006.
Myonuclei and satellite cells in denervated rat muscles: An electron microscopy study
Authors: de Castro Rodrigues Antonio , Andreo Jesus Carlos , de Mattos Rodrigues Silvana Perezin 
Published: June 2006

AbstractThe study and description of a separated cell type have been dependent on the evolution of the electron microscope. There have been few experiments designed to induce changes in myonucleus and satellite‐cell populations in vivo without physically injuring muscle. In this regard, the most practical method to experimentally alter myonucleus and satellite‐cell populations is denervation. The sciatic nerve was sectioned in order to observe myonuleus and satellite‐cell behavior. After 7, 16, and 38 weeks postdenervation, the soleus and extensor digitorum longus muscles were observed under electron microscopy. In each studied period, the pattern, distribution, and possible cellular alterations were observed in the studied muscles. Myonuclei exhibited alterations such as shrinkage, nuclear membrane separation, condensed chromatin, ghost nuclei as well as normal ones, and disorganized myofibrils. The maximum and minimum myonucleus diameters were measured in each studied period. In both muscles, the maximum diameters decreased. On the other hand, the minimum myonucleus diameters did not show any differences. Regarding satellite cells, activation characteristics were observed. In both muscles, the satellite cells were located distant of capillary after denervation. Characterization of the different types of nuclei abnormalities, especially in chromatin condensation, should provide useful information for future morphological studies. © 2006 Wiley‐Liss, Inc. Microsurgery, 2006.
Kidney transplantation procedures in rats: Assessments, complications, and management
Authors: Pahlavan Payam S. , Smallegange Corry , Adams Michael A. , Schumacher Martin 
Published: June 2006

AbstractKidney transplantation in rats is an experimental model often used for the development of general microsurgical or transplantation techniques, for immunologic studies, and for analyzing transplant‐associated long‐term arterial blood‐pressure changes. The aim of the present study was to analyze different surgical techniques of kidney transplantation in rats, with emphasis on minimizing surgical complications and establishing guidelines for their prevention and management. Complications were categorized into general (e.g., core body temperature drop, ischemic time) and surgically related vascular and urinary tract complications. In conclusion, a significant reduction of the complication rate in renal transplantation in rats can be achieved by placing the animal on a heating pad at an appropriate temperature. To reduce the risk of vascular thrombosis, ice‐cold saline with heparin and careful flushing of the donor kidneys are recommended. Vascular complications can be avoided by performing “end‐to‐end” anastomosis techniques. The use of stents and cannulas in the urinary tract is associated with a high risk of urinary tract obstruction, and therefore is not recommended. © 2006 Wiley‐Liss, Inc. Microsurgery, 2006.
Random matrix eigenvalue problems in structural dynamics
Authors: Adhikari S. , Friswell M. I. 
Published: June 2006

AbstractNatural frequencies and mode shapes play a fundamental role in the dynamic characteristics of linear structural systems. Considering that the system parameters are known only probabilistically, we obtain the moments and the probability density functions of the eigenvalues of discrete linear stochastic dynamic systems. Current methods to deal with such problems are dominated by mean‐centred perturbation‐based methods. Here two new approaches are proposed. The first approach is based on a perturbation expansion of the eigenvalues about an optimal point which is ‘best’ in some sense. The second approach is based on an asymptotic approximation of multidimensional integrals. A closed‐form expression is derived for a generalrth‐order moment of the eigenvalues. Two approaches are presented to obtain the probability density functions of the eigenvalues. The first is based on the maximum entropy method and the second is based on a chi‐square distribution. Both approaches result in simple closed‐form expressions which can be easily calculated. The proposed methods are applied to two problems and the analytical results are compared with Monte Carlo simulations. It is expected that the ‘small randomness’ assumption usually employed in mean‐centred‐perturbation‐based methods can be relaxed considerably using these methods. Copyright © 2006 John Wiley & Sons, Ltd.
Corotational non‐linear analysis of thin plates and shells using a new shell element
Authors: Khosravi Peyman , Ganesan Rajamohan , Sedaghati Ramin 
Published: June 2006

AbstractA new three‐node triangular shell element is developed by combining the optimal membrane element and discrete Kirchhoff triangle (DKT) plate bending element, and is modified for laminated composite plates and shells so as to include the membrane‐bending coupling effect. Using appropriate shape functions for the bending and membrane modes of the element, the ‘inconsistent’ stress stiffness matrix is formulated and the tangent stiffness matrix is determined. Non‐linear analysis of thin‐walled structures with geometric non‐linearity is conducted using the corotational method. The new element is thoroughly tested by solving few popular benchmark problems. The results of the analysis are compared with those obtained using existing membrane elements. Copyright © 2006 John Wiley & Sons, Ltd.
Mobility of spin probes in ionic liquids
Authors: Strehmel Veronika , Laschewsky André , Stoesser Reinhard , Zehl Andrea , Herrmann Werner 
Published: June 2006

AbstractThe spin probes TEMPO, TEMPOL, and CAT‐1 were used to investigate microviscosity and micropolarity of imidazolium based ionic liquids bearing either tetrafluoroborate or hexafluorophosphate as anions and a variation of the substitution at the imidazolium ion. The average rotational correlation times (τ) obtained by complete simulation of the X‐band ESR spectra of TEMPO, TEMPOL, and CAT‐1 increase with increasing viscosity of the ionic liquid although no Stokes Einstein behavior is observed. This is caused by microviscosity effects of the ionic liquids shown by application of the Gierer–Wirtz theory. Interestingly, the jump of the probe molecule into the free volume of the ionic liquids is a nonactivated process. The hyperfine coupling constants (Aiso (14N)) of TEMPO and TEMPOL dissolved in the ionic liquids do not depend on the structure of the ionic liquids. The Aiso (14N) values show a micropolarity of the ionic liquids that is comparable with methylenchloride in case of TEMPO and with dimethylsulfoxide in case of TEMPOL. Micropolarity monitored by CAT‐1 strongly depends on structural variation of the ionic liquid. CAT‐1 dissolved in imidazolium salts substituted with shorter alkyl chains at the nitrogen atom exhibits a micropolarity comparable with dimethylsulfoxide. A significant lower micropolarity is found for imidazolium salts bearing a longer alkyl substituent at the nitrogen atom or a methyl substituent at C‐2. Copyright © 2006 John Wiley & Sons, Ltd.
The kinetics and mechanisms of gas phase elimination of the ethyl ester of amino acid hydrochlorides
Authors: Chuchani Gabriel , Herize Armando , Domínguez Rosa María , Rotinov Alexandra , Tosta Maria 
Published: June 2006

AbstractThe kinetics of the gas phase elimination of the ethyl ester of four α‐amino acid hydrochlorides have been examined over the temperature range of 339–451°C and pressure range of 8–108 Torr. The reactions, in a static reaction system, are homogeneous, unimolecular, and follow a first‐order rate law. The rate coefficient is expressed by the following Arrhenius equations:Glycine ethyl ester hydrochloride:

Sarcosine ethyl ester hydrochloride:

DL‐Alanine ethyl ester hydrochloride:

L‐Phenylalanine ethyl ester hydrochloride

The elimination of these amino ester hydrochlorides leads to the formation of the corresponding α‐amino acid and ethylene. However, the amino acid intermediates, except sarcosine, under the condition of reaction temperatures, undergo an extremely rapid decarboxylation process. These results apparently support previous reported mechanistic consideration where α‐amino acids decompose to the corresponding amines and CO2 gas. Copyright © 2006 John Wiley & Sons, Ltd.
Characterization of de novo four‐helix bundles by molecular dynamics simulations
Authors: Scott Walter R. P. , Seo Emily , Huttunen Heidi , Wallhorn Diana , Sherman John C. , Straus Suzana K. 
Published: June 2006

AbstractWe have investigated the structure and dynamics of three cavitand‐based four‐helix bundles (caviteins) by computer simulation. In these systems, designed de novo, each of the four helices contain the identical basis sequence EELLKKLEELLKKG (N1). Each cavitein consists of a rigid macrocycle (cavitand) with four aryl linkages, to each of which is connected an N1 peptide by means of a linker peptide. The three caviteins studied here differ only in the linker peptide, which consist of one, two, or three glycine residues. Previous experimental work has shown that these systems exhibit very different behavior in terms of stability and oligomerization states despite the small differences in the linker peptide. Given that to date no three‐dimensional structure is available for these caviteins, we have undertaken a series of molecular dynamics (MD) simulations in explicit water to try to rationalize the large differences in the experimentally observed behavior of these systems. Our results provide insight, for the first time, into why and how the cavitein with a single glycine linker forms dimers. In addition, our results indicate why although the two‐ and three‐glycine‐linked caviteins have similar stabilities, they have different native‐like characteristics: the cavitein with three glycines can form a supercoiled helix, whereas the one with two glycines cannot. These findings may provide a useful guide in the rational de novo design of novel proteins with finely tunable structures and functions in the future. Proteins 2006. © 2006 Wiley‐Liss, Inc.
QSPR Models for Various Properties of Polymethacrylates Based on Quantum Chemical Descriptors
Authors: Liu Wanqiang , Yi Pinggui , Tang Zilong 
Published: June 2006

AbstractThe structural units of 35 polymethacrylates have been optimized and their quantum chemical descriptors have been calculated via density functional theory method at 6‐31G (d) basis set level. The quantitative structure–property relationships of the quantum chemical descriptors and properties, such as molar volumes at room temperature V298K, refractive index n, and glass transition temperature Tg, have been obtained by stepwise regression and Artificial Neural Network (ANN) method. The values of the correlation coefficient R for the calculated and the experimental data are 0.9968 and 0.9949 for V298K, 0.9918 and 0.9980 for n, 0.9609 and 0.9708 for Tg, respectively. The results calculated by ANN method meet the experimental data better than those by the stepwise method.
Characterization of Fe, Cu and Zn in organs of PDAPP transgenic mice by XRF spectrometry
Authors: Zhang Z. Y. , Liu N. Q. , Li F. L. , Zhang J. , Zhu H. , Qin C. , Zou Z. Y. , Tang X. W. 
Published: June 2006

AbstractA large body of evidence indicates that abnormalities in the levels of iron, copper and zinc and their metabolism are associated with neurodegenerative diseases. However, it is difficult to decide whether any observed changes of trace elements reflect the primary disease process or are secondary to a primary process or mechanism. In the present study, Fe, Cu and Zn in organs of transgenic mice which express the familial Alzheimer's disease (AD) gene and normal mice of the same species and ages were determined by X‐ray fluorescence (XRF) spectrometry. The results show that Fe concentrations in a variety of organs and tissues were significantly increased whereas Zn concentrations decreased in the transgenic mice as compared with the ‘normals’. The levels of Cu in transgenic mice were also altered. Data obtained in the present study suggest that expression of the familial AD gene in mice results in altered homeostasis of Fe, Cu and Zn in organs of the animals, which may in turn accelerate the process of neurodegeneration. Copyright © 2006 John Wiley & Sons, Ltd.
Accurate calculation of pileup effects in PIXE spectra from first principles
Authors: Barradas N. P. , Reis M. A. 
Published: June 2006

AbstractBackground subtraction in PIXE spectra has been a persistent problem in PIXE data analysis. Pile‐up represents an important contribution to the background, but its treatment in software codes handling PIXE spectra frequently suffers from strong or even incorrect approximations. This paper gives a short review of various studies and methods of pile‐up correction and applies an analytic calculation based on first principles for PIXE spectra pile‐up subtraction. No distinction between peak and continuum contributions is necessary. The only parameters required for the calculation are the collection time, the shaping time of the amplifier and the resolving time of the pile‐up rejection system, without any need for normalisation constants. Calculations are presented for a series of experimental PIXE spectra, for different count rates and amplifier shaping times and spectra collected with the pile‐up rejection system on and off. The agreement between calculated and observed pile‐up is excellent. Copyright © 2006 John Wiley & Sons, Ltd.
Dispersion corrections to the forward Rayleigh scattering amplitudes around the L‐shell of tantalum and lead
Authors: Appaji Gowda S. B. , Umesh T. K. 
Published: June 2006

AbstractDispersion corrections to the forward Rayleigh scattering amplitudes of tantalum and lead in the photon energy range 6.4–24.14 keV were determined by a numerical evaluation of the dispersion integral that relates them through the optical theorem to the photoelectric cross‐sections. The photoelectric cross‐sections were extracted by subtracting the coherent and incoherent scattering contribution from the measured total attenuation cross‐section, using a high‐resolution, high‐purity germanium detector in a narrow‐beam good geometry setup. The real part of the dispersion correction to which the relativistic corrections calculated by Kissel and Pratt (S‐matrix approach) or Creagh and McAuley (multipole corrections) have been included are in better agreement with the available theoretical values than those values to which the relativistic corrections calculated by Cromer and Liberman (dipole corrections) are added. Copyright © 2006 John Wiley & Sons, Ltd.
Phosphorylation of the α subunit of translation initiation factor-2 by PKR mediates protein synthesis inhibition in the mouse brain during status epilepticus
Authors: Carnevalli Larissa S. , Pereira Catia M. , Jaqueta Carolina B. , Alves Viviane S. , Paiva Vanessa N. , Vattem Krishna M. , Wek Ronald C. , Mello Luiz Eugênio A. M. , Castilho Beatriz A. 
Published: June 2006

In response to different cellular stresses, a family of protein kinases phosphorylates eIF2α (α subunit of eukaryotic initiation factor-2), contributing to regulation of both general and genespecific translation proposed to alleviate cellular injury or alternatively induce apoptosis. Recently, we reported eIF2α(P) (phosphorylated eIF2α) in the brain during SE (status epilepticus) induced by pilocarpine in mice, an animal model of TLE (temporal lobe epilepsy) [Carnevalli, Pereira, Longo, Jaqueta, Avedissian, Mello and Castilho (2004) Neurosci. Lett. 357, 191–194]. We show in the present study that one eIF2α kinase family member, PKR (double-stranded-RNA-dependent protein kinase), is activated in the cortex and hippocampus at 30 min of SE, reflecting the levels of eIF2α(P) in these areas. In PKR-deficient animals subjected to SE, eIF2α phosphorylation was clearly evident coincident with activation of a secondary eIF2α kinase, PEK/PERK (pancreatic eIF2α kinase/RNA-dependent-protein-kinase-like endoplasmic reticulum kinase), denoting a compensatory mechanism between the two kinases. The extent of eIF2α phosphorylation correlated with the inhibition of protein synthesis in the brain, as determined from polysome profiles. We also found that C57BL/6 mice, which enter SE upon pilocarpine administration but are more resistant to seizure-induced neuronal degeneration, showed very low levels of eIF2α(P) and no inhibition of protein synthesis during SE. These results taken together suggest that PKR-mediated phosphorylation of eIF2α contributes to inhibition of protein synthesis in the brain during SE and that sustained high levels of eIF2α phosphorylation may facilitate ensuing cell death in the most affected areas of the brain in TLE.
Elimination of 2-keto-3-deoxy-D-glycero-D-galacto-nonulosonic acid 9-phosphate synthase activity from human N-acetylneuraminic acid 9-phosphate synthase by a single mutation
Authors: Hao Jijun , Vann Willie F. , Hinderlich Stephan , Sundaramoorthy Munirathinam 
Published: June 2006

The most commonly occurring sialic acid Neu5Ac (N-acetylneuraminic acid) and its deaminated form, KDN (2-keto-3-deoxy-D-glycero-D-galacto-nonulosonic acid), participate in many biological functions. The human Neu5Ac-9-P (Neu5Ac 9-phosphate) synthase has the unique ability to catalyse the synthesis of not only Neu5Ac-9-P but also KDN-9-P (KDN 9-phosphate). Both reactions are catalysed by the mechanism of aldol condensation of PEP (phosphoenolpyruvate) with sugar substrates, ManNAc-6-P (N-acetylmannosamine 6-phosphate) or Man-6-P (mannose 6-phosphate). Mouse and putative rat Neu5Ac-9-P synthases, however, do not show KDN-9-P synthase activity, despite sharing high sequence identity (&gt;95%) with the human enzyme. Here, we demonstrate that a single mutation, M42T, in human Neu5Ac-9-P synthase can abolish the KDN-9-P synthase activity completely without compromising the Neu5Ac-9-P synthase activity. Saturation mutagenesis of Met42 of the human Neu5Ac-9-P synthase showed that the substitution with all amino acids except leucine retains only the Neu5Ac-9-P synthase activity at levels comparable with the wild-type enzyme. The M42L mutant, like the wild-type enzyme, showed the additional KDN-9-P synthase activity. In the homology model of human Neu5Ac-9-P synthase, Met42 is located 22 Å (1 Å=0.1 nm) away from the substrate-binding site and the impact of this distant residue on the enzyme functions is discussed.
Sugar-induced increases in trehalose 6-phosphate are correlated with redox activation of ADPglucose pyrophosphorylase and higher rates of starch synthesis in Arabidopsis thaliana
Authors: Lunn John E. , Feil Regina , Hendriks Janneke H. M. , Gibon Yves , Morcuende Rosa , Osuna Daniel , Scheible Wolf-Rüdiger , Carillo Petronia , Hajirezaei Mohammad-Reza , Stitt Mark 
Published: June 2006

Tre6P (trehalose 6-phosphate) is implicated in sugar-signalling pathways in plants, but its exact functions in vivo are uncertain. One of the main obstacles to discovering these functions is the difficulty of measuring the amount of Tre6P in plant tissues. We have developed a highly specific assay, using liquid chromatography coupled to MS-Q3 (triple quadrupole MS), to measure Tre6P in the femto-picomole range. The Tre6P content of sucrose-starved Arabidopsis thaliana seedlings in axenic culture increased from 18 to 482 pmol·g−1FW (fresh weight) after adding sucrose. Leaves from soil-grown plants contained 67 pmol·g−1FW at the end of the night, which rose to 108 pmol·g−1FW after 4 h of illumination. Even greater changes in Tre6P content were seen after a 6 h extension of the dark period, and in the starchless mutant, pgm. The intracellular concentration of Tre6P in wild-type leaves was estimated to range from 1 to 15 μM. It has recently been reported that the addition of Tre6P to isolated chloroplasts leads to redox activation of AGPase (ADPglucose pyrophosphorylase) [Kolbe, Tiessen, Schluepmann, Paul, Ulrich and Geigenberger (2005) Proc. Natl. Acad. Sci. U.S.A. 102, 11118–11123]. Using the new assay for Tre6P, we found that rising sugar levels in plants are accompanied by increases in the level of Tre6P, redox activation of AGPase and the stimulation of starch synthesis in vivo. These results indicate that Tre6P acts as a signalling metabolite of sugar status in plants, and support the proposal that Tre6P mediates sucrose-induced changes in the rate of starch synthesis.