bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparative study of the COX‐1 and COX‐2 isozymes bound to lipid membranes
Authors: Wan Shunzhou , Coveney Peter V.
Published: October 2008

The monotopic proteins COX‐1 and ‐2 in dimeric form bound to lipid bilayer membranes are studied using molecular dynamics simulations within an aqueous environment. The 25‐ns simulations are performed for both isozymes with arachidonic acid bound in the cyclooxygenase sites. The interactions between the enzymes and the lipids are analyzed, providing insight into the attachment mechanism of monotopic proteins to membranes. Our study reveals some key differences between the two isozymes that include the orientations at which they sit on the surface of the membranes and the depths to which they embed within the membranes. The differences in membrane association of the isozymes indicate that they may integrate distinctively with the same membrane, and/or with different membranes or their lipid components. Our results indicate that arachidonic acid can be bound in the cyclooxygenase active site in distinct catalytically competent conformations that lead to certain hydroperoxy acids; and the arachidonic acid and/or cyclooxygenase sites undergo a conformational change which makes only one subunit of each homodimer catalytically active. © 2008 Wiley Periodicals, Inc. J Comput Chem 2009
Interaction of two functional groups through the benzene ring: Theory and experiment
Authors: Böhm Stanislav , Exner Otto
Published: October 2008

Energies of 132 benzene para bis‐derivatives calculated within the framework of the density functional theory at the level B3LYP/6‐311+G(d,p)//B3LYP/6‐311+G(d,p) were used for correlations of two types. Correlation with the experimental enthalpies of formation clearly revealed that the published experimental data are generally not dependable and may be loaded with errors of more than 10 kJ mol−1. On the other hand, the calculated relative energies are biased so that the interaction of the two substituents is systematically overestimated. This shortcoming was insignificant for our correlations of the second type, in which the interaction of substituents expressed in terms of isodesmic reactions was analyzed depending on the effects of inductive and resonance. The results depended strongly on the character of substituents. When one substituent is an electron donor and the other is an acceptor, the inductive‐resonance model works and the classical resonance picture is adequate. With two acceptor substituents, this model is still acceptable with lower precision (as crossed conjugation), but with two donors it fails completely and may be acceptable only for a much restricted subclass of strong donors. Many correlations described in the literature must be viewed with great caution when they are based only on a relatively small number of data, in which substituents of different types are not represented in a comparable number. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
CASSCF and multireference CI with singles and doubles study of low‐lying valence and Rydberg states of 2H‐tetrazole
Authors: de Souza Miguel A. F. , Ventura Elizete , Araújo Regiane C. M. U , Ramos Mozart N. , do Monte Silmar A.
Published: October 2008

Complete active space self‐consistent field (CASSCF) and multireference CI with singles and doubles (MR‐CISD) calculations [including extensivity corrections, at MR‐CISD+Q and multireference averaged quadratic coupled cluster (MR‐AQCC) levels] have been performed to characterize the low‐lying valence and the Rydberg states of 2H‐tetrazole. The highest level results (MR‐AQCC/d′‐aug′‐cc‐pVDZ) indicate the following ordering of the valence singlet excited states: S1 (n–π*), 6.06 eV; S2 (n–π*), 6.55 eV; S3 (π–π*), 6.55 eV. The MR‐CISD+Q/d′‐aug′‐cc‐pVDZ results indicate the same ordering, but at slight higher energies: 6.16, 6.68, and 6.69 eV, respectively. According to our MR‐CISD+Q/d′‐aug′‐cc‐pVDZ results, the next two states are Rydberg states, at 7.69 eV (π–3s) and 7.89 eV (n–3s). The calculated energies of these two states, as well as their proximity, are consistent with the conclusion reached by Palmer and Beveridge (Chem Phys 1987, 111, 249) that the first band of the photoelectron spectrum of 2H‐tetrazole is likely to be associated to the first two ionizations processes (of π and N lone pair electrons), at energies close to 11.3 eV. © 2008 Wiley Periodicals, Inc. J Comput Chem 2009
An efficient grid‐based scheme to compute QTAIM atomic properties without explicit calculation of zero‐flux surfaces
Authors: Rodríguez Juan I. , Köster Andreas M. , Ayers Paul W. , Santos‐Valle Ana , Vela Alberto , Merino Gabriel
Published: October 2008

We introduce a method to compute atomic properties according to the “quantum theory of atoms in molecules.” An integration grid in real space is partitioned into subsets, ωi. The subset, ωi, is composed of all grid points contained in the atomic basin, Ωi, so that integration over Ωiis reduced to simple quadrature over the points in ωi. The partition is constructed from deMon2k's atomic center grids by following the steepest ascent path of the density starting from each point in the grid. We also introduce a technique that exploits the cellular nature of the grid to make the algorithm faster. The performance of the method is tested by computing properties of atoms and nonnuclear attractors (energies, charges, dipole, and quadrupole moments) for a set of representative molecules. © 2008 Wiley Periodicals, Inc. J Comput Chem 2009
The nitrogen edge‐doped effect on the static first hyperpolarizability of the supershort single‐walled carbon nanotube
Authors: Xu Hong‐Liang , Wang Fang‐Fang , Li Zhi‐Ru , Wang Bing‐Qiang , Wu Di , Chen Wei , Yu Guang‐Tao , Gu Feng Long , Aoki Yuriko
Published: October 2008

The nitrogen edge‐doped effect on the structure, dipole moment, and first hyperpolarizability of the supershort single‐walled carbon nanotube (5, 0) has been studied systematically. For the nitrogen edge‐doped effect on the structure, the mean diameter on the nitrogen‐doped side (Du) decreases as the number of doped‐nitrogen (n) increases (4.044 (1) > 3.991 (2) > 3.941 (3) > 3.891 (4) > 3.844 Å (5)). Significantly, the nitrogen edge‐doped effects on the dipole moment and first hyperpolarizability are revealed for the first time and these new effects are dramatic for the supershort single‐walled carbon nanotube (5, 0). Among the β0 values of these seven nitrogen‐doped structures, the largest β0 (3155 au) is larger by almost 450 times than the very small β0 (7 au) of undoped structure (D5h). For nitrogen‐doped structures, the order of the β0 values is 3155 (1) > 2677 (2A) ≈ 2817 (2B) > 1465 (3A) ≈ 1458 (3B) > 670 (4) > 254 au (5), which shows two interesting relationships between the β0 value and nitrogen‐doped number: (1) the smaller the nitrogen‐doped number, the larger the β0 value. (2) The structures with the same number of doped‐nitrogen have almost the same β0 values (1465 for 3A and 1458 au for 3B). As for the frequency‐dependent β (−ω; ω, 0) and β (−2ω; ω, ω), the dependence on the nitrogen‐doped number (n) is similar to the case of static β0. For β (−2ω; ω, ω) values at ω = 0.005 au are 3220 (1) > 2720 (2A) ≈ 2862 (2B) > 1480 (3A) ≈ 1477 (3B) > 676 (4) > 256 au (5). In addition, the important monotonic dependences of the β value on the Du and electronic spatial extent 〈R2〉 are also observed. The new knowledge of influence the β value will be beneficial to design high‐performance nonlinear optical (NLO) materials. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Conformational transition pathway in the allosteric process of calcium‐induced recoverin: Molecular dynamics simulations
Authors: Li Ji‐Lai , Geng Cai‐Yun , Bu Yuxiang , Huang Xu‐Ri , Sun Chia‐Chung
Published: October 2008

Recoverin is an important neuronal calcium sensor (NCS) protein, which have been implicated in a wide range of Ca2+ signaling events in neurons and photoreceptors. To characterize the conformational transition of recoverin from the myristoyl sequestered state to the extrusion state, a series of conventional molecular dynamics (CMD) and targeted molecular dynamics (TMD) simulations were performed. The 36.8 ns long CMD and TMD simulations on recoverin revealed a reliably conformational transition pathway, which can be viewed as a sequential two‐stage process. A very important mechanistic conclusion from the present TMD simulations is that the hydrophobic and hydrophilic interactions modulate the allostery cooperatively in the conformational transition pathway. In the first stage, three salt‐bridges broken between Lys‐84 and Gly‐124, between Lys‐5 and Glu‐103 and between Gly‐16 and Lys‐97 are major components to destabilize the structure of state T and trigger the swivel of the N‐ and C‐terminal domains. In the second stage, the rupture of H‐bond Phe‐56‐O…H(O)‐Thr‐21 leads to the two helices of EF‐1 apart from each other, destabilizing the hydrophobic interactions of the myristoyl group with its environment, whereas the making of H‐bond Leu‐108‐O…H(O)‐Ser‐72 helps the interfacial domain maintain its structural integrity during the course of the myristoyl extrusion. The molecular dynamics simulations results are beneficial to understanding the mechanism of how and why NCS proteins make progress in the photo‐signal transduction processes. Further experimental and theoretical studies are still very desirable. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Notes on quantitative structure‐properties relationships (QSPR) (1): A discussion on a QSPR dimensionality paradox (QSPR DP) and its quantum resolution
Authors: Carbó‐Dorca Ramon , Gallegos Ana , Sánchez Ángel J.
Published: October 2008

Classical quantitative structure‐properties relationship (QSPR) statistical techniques unavoidably present an inherent paradoxical computational context. They rely on the definition of a Gram matrix in descriptor spaces, which is used afterwards to reduce the original dimension via several possible kinds of algebraic manipulations. From there, effective models for the computation of unknown properties of known molecular structures are obtained. However, the reduced descriptor dimension causes linear dependence within the set of discrete vector molecular representations, leading to positive semi‐definite Gram matrices in molecular spaces. To resolve this QSPR dimensionality paradox (QSPR DP) here is proposed to adopt as starting point the quantum QSPR (QQSPR) computational framework perspective, where density functions act as infinite dimensional descriptors. The fundamental QQSPR equation, deduced from employing quantum expectation value numerical evaluation, can be approximately solved in order to obtain models exempt of the QSPR DP. The substitution of the quantum similarity matrix by an empirical Gram matrix in molecular spaces, build up with the original non manipulated discrete molecular descriptor vectors, permits to obtain classical QSPR models with the same characteristics as in QQSPR, that is: possessing a certain degree of causality and explicitly independent of the descriptor dimension. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Examination of selected atmospheric and orographic effects on monthly precipitation of Taiwan using the ASOADeK model
Authors: Guan Huade , Hsu Huang‐Hsiung , Makhnin Oleg , Xie Hongjie , Wilson John L.
Published: October 2008

Characterization and quantification of precipitation spatial variability are required for many studies, such as those in hydrology, ecology, forestry and agriculture. In mountainous terrains (e.g. Taiwan), interactions of moist air mass with underlying complex topography result in increased but often predictable precipitation spatial variability. When these interactions are quantitatively captured, they can contribute to precipitation mapping. In this paper, we applied a recently developed multivariate regression model [auto‐searched orographic and atmospheric effects de‐trended kriging (ASOADeK) regression] to examine selected atmospheric and orographic effects: atmospheric moisture gradient (MG), terrain elevation (Z), terrain aspect and related moisture flux direction (MFD), on Taiwan mean monthly precipitation climatology, primarily based on a dense gauge network (about 110 gauges per 10 000 km2). The results indicate that (1) the regression captures over 50% of spatial variability in mean monthly precipitation over the whole Taiwan island, with improved performance when the regression is applied to sectional regions; (2) the atmospheric MG and MFD are significant factors explaining mean monthly precipitation spatial variability in Taiwan, whereas the elevation effect is not as significant; (3) when the data of sectional regions are applied in the regression, the inferred MFDs vary in a certain range, indicating slightly different climate setting between northern and southern parts of Taiwan; (4) the degree of agreement between the ASOADeK regression‐inferred MFDs and local observed prevailing winds is systemic, and can be used to explain the contrast of rainfall seasonality patterns between the northern part and the rest of Taiwan; and (5) a gauge network of 50 gauges per 10 000 km2 is sufficient to capture the orographic effect on mean monthly precipitation distribution. Copyright © 2008 Royal Meteorological Society
Preliminary 10Be chronology for the last deglaciation of the western margin of the Greenland Ice Sheet
Authors: Rinterknecht Vincent , Gorokhovich Yuri , Schaefer Joerg , Caffee Marc
Published: October 2008

The now acknowledged thinning of the Greenland Ice Sheet raises concerns about its potential contribution to future sea level rise. In order to appreciate the full extent of its contribution to sea level rise, reconstruction of the ice sheet's most recent last deglaciation could provide key information on the timing and the height of the ice sheet at a time of rapid climate readjustment. We measured 10Be concentrations in 12 samples collected along longitudinal and altitudinal transects from Sisimiut to within 10 km of the Isunguata Sermia Glacier ice margin on the western coast of Greenland. Along the longitudinal transect, we collected three perched boulders and two bedrocks. In addition, we sampled seven perched boulders along a vertical transect in a valley within 10 km of the Isunguata Sermia Glacier ice margin. Our pilot dataset constrains the height of the ice sheet during the Last Glacial Maximum (LGM) between 500 m and 840 m (including the 120 m relative sea level depression at the time of the LGM, 21 ka BP). From the transect we estimate the thinning of the ice sheet at the end of the deglaciation between 12.3 ± 1.5 10Be ka (n = 2) and 8.3 ± 1.2 10Be ka (n = 3) to be ∼6 cm a−1 over this time period. Direct dating of the retreat of the western margin of the Greenland Ice Sheet has the potential to better constrain the retreat rate of the ice margin, the thickness of the former ice sheet as well as its response to climate change. Copyright © 2008 John Wiley & Sons, Ltd.
Kinetics and products of chlorine atom initiated oxidation of HCF2OCF2OCF2CF2OCF2H and HCF2O(CF2O)n‐(CF2CF2O)mCF2H
Authors: Wallington T. J. , Hurley M. D. , Javadi M. S. , Nielsen O. J.
Published: October 2008

Smog chamber/FTIR techniques were used to measure k(Cl + HCF2OCF2OCF2‐CF2OCF2H) = k(Cl + HCF2O(CF2O)n(CF2CF2O)mCF2H) = (5.0 ± 1.4) × 10−17 cm3 molecule−1 s−1 in 700 Torr of N2/O2 diluent at 296 ± 1 K. The Cl‐initiated atmospheric oxidation of HCF2OCF2OCF2CF2OCF2H and the sample of HCF2O(CF2O)n(CF2CF2O)mCF2H used in this work gave COF2 in molar yields of (476 ± 36)% and (859 ± 63)%, respectively, with no other observable carbon containing products (i.e., essentially complete conversion of both hydrofluoropolyethers into COF2). The results are discussed with respect to the atmospheric chemistry and environmental impact of hydrofluoropolyethers of the general formula HCF2O(CF2O)n(CF2CF2O)mCF2H. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 819–825, 2008
Physical therapy in Parkinson's disease: Evolution and future challenges
Authors: Keus Samyra H.J. , Munneke Marten , Nijkrake Maarten J. , Kwakkel Gert , Bloem Bastiaan R.
Published: October 2008

Even with optimal medical management using drugs or neurosurgery, patients with Parkinson's disease (PD) are faced with progressively increasing mobility problems. For this reason, many patients require additional physical therapy. Here, we review the professional evolution and scientific validation of physical therapy in PD, and highlight several future challenges. To gain insight in ongoing, recently completed or published trials and systematic reviews, we performed a structured literature review and contacted experts in the field of physical therapy in PD. Following publication of the first controlled clinical trial in 1981, the quantity and quality of clinical trials evaluating the efficacy of physical therapy in PD has evolved rapidly. In 2004 the first guideline on physical therapy in PD was published, providing recommendations for evidence‐based interventions. Current research is aiming to gather additional evidence to support specific intervention strategies such as the prevention of falls, and to evaluate the implementation of evidence into clinical practice. Although research focused on physical therapy for PD is a relatively young field, high‐quality supportive evidence is emerging for specific therapeutic strategies. We provide some recommendations for future research, and discuss innovative strategies to improve the organization of allied health care in PD, making evidence‐based care available to all PD patients. © 2008 Movement Disorder Society
Functional effects of local thyroid hormone administration after sciatic nerve injury in rats
Authors: Papakostas Ioannis , Mourouzis Iordanis , Mourouzis Kostas , Macheras Georgios , Boviatsis Efstathios , Pantos Constantinos
Published: October 2008

This study investigates potential functional effects of thyroid hormone (T3) on peripheral nerve regeneration in rats. Forty adult male Lewis rats were included in this study. After complete transection of the right sciatic nerve, the gap between the stumps was bridged with a silicone tube. In the first experimental group (group A, n = 12), T3 solution was used to fill the tube, whereas a sterile buffer solution was used in nontreated rats, (group B, n = 12). Additionally, sham operation with surgical incision and mobilization of the sciatic nerve without any other intervention was performed (group C, n = 10). In a few animals, α‐segment of the nerve was excised and the stumps were reversed to exclude the possibility of regeneration (group D, n = 6). The process of peripheral nerve regeneration was assessed by functional indices at 3, 6, 9, 13, and 17 weeks postoperatively. Mid‐stance angle, at the ankle, measured in degrees, was used as a kinematic index and the withdrawal reflex (measured in grams of applied force) was used to evaluate the return of sensory function. Kinematic indexes were not different between the groups A and B at all time points of the evaluation. Sensory function was significantly different in T3‐treated animals compared with buffer‐treated control group (x vs. y, P = 0.031) at 9 weeks. Thereafter, sensory function was comparable between groups. In conclusion, T3 seems to accelerate the return of sensory function after complete transection of the sciatic nerves in Lewis rats without a significant effect on motor nerve recovery. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Fibrin glue application in microvascular anastomosis: Comparative study of two free flaps series
Authors: Cho Alvaro B. , Wei Teng Hsiang , Torres Luciano Ruiz , Júnior Rames Mattar , Rugiero Gustavo Mantovani , Aita Márcio Aurélio
Published: October 2008

Background: Since the first experiments with fibrin glue application in microvascular anastomoses in 1977, several studies have reported its benefits on suture reduction and anastomosis decreased time. In spite of that, clinical experience has been limited to two neurosurgical and two replantation case series, all of them with good results. This study was conducted to evaluate the feasibility and the potential benefits of fibrin glue application in free flaps. Methods: We performed 24 free flaps in 24 patients, from March 2005 to June 2006. Twenty were included in this study. They were divided into two groups according to the anastomosis technique: conventional group (n = 7 patients) and fibrin glue group (n = 13 patients). In the conventional group, the anastomosis was performed with interrupted sutures, whereas in the fibrin glue group, they were performed using less sutures and fibrin glue application. Results: The application of fibrin glue cut by half the number of sutures required to complete the anastomoses. The mean arterial and venous anastomotic times in the conventional group were 27.2 and 24.0 minutes, respectively. In the fibrin glue group, they were 13.6 and 12.6 minutes, respectively. All these differences were statistically significant. There was no significant difference of ischemic time between two groups (P = 0.26). The survival rate of the flaps was similar in both groups: 84.6% (11 of 13) in the fibrin glue group and 85.7% (6 of 7) in the conventional group (P = 1.0). Conclusions: Fibrin glue application in free flaps was feasible and allowed us to complete the anastomoses with fewer sutures and less time. The survival rate of the flaps was not adversely affected by the fibrin glue. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Neovascularization and free microsurgical transfer of in vitro cartilage‐engineered constructs
Authors: Hoang Nguyen The , Hoehnke Christoph , Hien Pham Thu , Mandlik Veronika , Feucht Achim , Staudenmaier Rainer
Published: October 2008

Cartilage tissue engineering shows to have tremendous potential for the reconstruction of three‐dimensional cartilage defects. To ensure survival, shape, and function, in vitro cartilage‐engineered constructs must be revascularized. This article presents an effective method for neovascularization and free microsurgical transfer of these in vitro constructs. Twelve female Chinchilla Bastard rabbits were used. Cartilage‐engineered constructs were created by isolating chondrocytes from auricular biopsies, amplifying in monolayer culture, and then seeding them onto polycaprolactone scaffolds. In each prefabricated skin flap, three in vitro cartilage‐engineered constructs (2 × 2 × 0.5 cm) and one construct without cells (served as the control) were implanted beneath an 8 × 15 cm random‐pattern skin flap, neovascularized by implantation of an arteriovenous vascular pedicle with maximal blood flow. Six weeks later, the neovascularized flaps with embedded cartilage‐engineered constructs were completely removed based on the newly implanted vascular pedicle, and then freely retransferred into position using microsurgery. Macroscopic observation, selective microangiography, histology, and immunohistochemistry were performed to determine the construct vitality, neovascularization, and new cartilage formation. The results showed that all neovascularized skin flaps with embedded constructs were successfully free‐transferred as free flaps. The implanted constructs were well integrated and protected within the flap. All constructs were well neovascularized and showed histologically stability in both size and form. Immunohistology showed the existence of cartilage‐like tissue with extracellular matrix neosynthesis. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Is splenectomy a dyslipidemic intervention? Experimental response of serum lipids to different diets and operations
Authors: Paulo Danilo N. S. , Paulo Isabel Cal , Morais Alvaro A. C. , Kalil Mitre , Guerra Alvino J. , Colnago Geraldo L. , Faintuch Joel
Published: October 2008

Spleen removal may be recommended during organ transplantation in ABO‐incompatible recipients as well as for hypoperfusion of the grafted liver, besides conventional surgical indications, but elevation of serum lipids has been observed in certain contexts. Aiming to analyze the influence of two dietary regimens on lipid profile, an experimental study was conducted. Methods: Male Wistar rats (n = 86, 333.0 ± 32.2 g) were divided in four groups: group 1: controls; group 2: sham operation; group 3: total splenectomy; group 4: subtotal splenectomy with upper pole preservation; subgroups A (cholesterol reducing chow) and B (cholesterol‐rich mixture) were established, and diet was given during 90 days. Total cholesterol (Tchol), high‐density lipoprotein (HDL), low‐density lipoprotein (LDL), very‐low‐density lipoprotein (VLDL), and triglycerides were documented. Results: After total splenectomy, hyperlipidemia ensued with cholesterol‐reducing chow. Tchol, LDL, VLDL, triglycerides, and HDL changed from 56.4 ± 9.2, 24.6 ± 4.7, 9.7 ± 2.2, 48.6 ± 11.1, and 22.4 ± 4.3 mg/dL to 66.9 ± 11.4, 29.9 ± 5.9, 10.9 ± 2.3, 54.3 ± 11.4, and 26.1 ± 5.1 mg/dL, respectively. Upper pole preservation inhibited abnormalities of Tchol, HDL, VLDL, and triglycerides, and LDL decreased (23.6 ± 4.9 vs. 22.1 ± 5.1, P = 0.002). Higher concentrations were triggered by splenectomy and cholesterol‐enriched diet (Tchol 59.4 ± 10.1 vs. 83.9 ± 14.3 mg/dL, P = 0.000), and upper‐pole preservation diminished without abolishing hyperlipidemia (Tchol 55.9 ± 10.0 vs. 62.3 ± 7.8, P = 0.002). Conclusions: After splenectomy, hyperlipidemia occurred with both diets. Preservation of the upper pole tended to correct dyslipidemia in modality A and to attenuate it in subgroup B. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Lipomatosis of the sciatic nerve: Report of a case and review of the literature
Authors: Fandridis Emmanouil M. , Kiriako Alexandros S. , Spyridonos Sarantis G. , Delibasis Georgios E. , Bourlos Dimitrios N. , Gerostathopoulos Nikolaos E.
Published: October 2008

We report a case of lipomatosis of the sciatic nerve, also known as lipofibromatous hamartoma. A male, 26‐year‐old, presented with gait impairment, leg pain, and foot drop compatible with sciatic nerve's compression. The preoperative magnetic resonance imaging (MRI) revealed diffuse thickening of the proximal third of the sciatic nerve with adipose tissue interspersed among the nerve fascicles. Internal neurolysis was performed with microsurgical techniques under high magnification. The patient was followed up for a period of 34 months. He significantly recovered, and there was no clinical recurrence of the tumor. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Motor nerve regeneration across a conduit
Authors: Rosson Gedge D. , Williams Eric H. , Dellon A. Lee
Published: October 2008

A 3‐cm gap in the ulnar nerve at the elbow in a subhuman primate was the first model of nerve regeneration across a polyglycolic, bioabsorbable conduit. When a prospective trial was begun in humans, the first clinically available bioabsorbable conduit, the Neurotube™, was utilized to reconstruct sensory nerves, but motor nerve injuries were not included. Thus, we sought to evaluate our patients with short‐gap motor nerve injuries repaired with bioabsorbable conduits. We performed a retrospective chart review of all patients with bioabsorbable nerve conduit repair of short‐gap motor nerve injuries over a 7‐year period—six patients were identified. All patients had some return of motor function. Our case series, along with the nonhuman primate studies and other human reports, demonstrates that motor nerves will regenerate through bioabsorbable conduits and will reinnervate appropriate motor‐target end‐organs if they can reach them within an appropriate time frame for persistence of the motor‐endplates. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Brachial plexus lesions: 10 Years of experience in a center for microsurgery in Germany
Authors: Lanaras Tatjana Ismini , Schaller Hans‐Eberhard , Sinis Nektarios
Published: October 2008

Aim: Brachial plexus lesions are commonly associated with complete or partial plegia of affected muscles even after microsurgical treatment. This study provides an overview of strategies and outcomes of 42 patients operated in a center for peripheral nerve surgery in Germany. Methods: Postsurgically, the patients were followed up and examined for strength in various muscle groups by applying a standard clinical classification (M0–M5). Sensitivity was estimated by differentiation between blunt and sharp touch. The patients were asked via questionnaire about their postsurgical daily life. Most of the patients received a grafting procedure using the sural nerve. Different microsurgical techniques were applied according to the underlying pathology: Intercostal nerve transfer, end‐to‐side coaptation, and direct grafting to different recipient nerves. Results: Only the 27 patients, who had a follow‐up time of at least 36 months, presented a measurable function in the affected extremity. Elbow‐flexion was restored in 15 cases. Triceps function was reconstructed in 7 patients of 27. One patient was able to move digits toward the palm without completing a full fist. Ten patients were able to flex the wrist and 4 could extend it. Conclusion: The results were estimated as acceptable for biceps reconstruction but poor for the other muscle groups. Some treatment strategies, which are presently under frequent discussion (contralateral C7‐transfer, banked autografts, Oberlin procedure), were not applied. However, some of these techniques may provide a key to improve the results. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Comparison of regeneration results of prefabricated nerve graft, autogenous nerve graft, and vein graft in repair of nerve defects
Authors: Karagoz Huseyin , Ulkur Ersin , Uygur Fatih , Senol Mehmet Guney , Yapar Mehmet , Turan Pinar , Celikoz Bahattin
Published: October 2008

The purpose of this study was to evaluate the effectivity of prefabricated nerve grafts in the repairing nerve defect and to compare them with the autogenous nerve graft and vein graft. Four groups were created, each containing 10 rats. First, nerve prefabrication was carried out in groups I and II during 8 weeks. For this purpose, jugular vein graft was sutured to the epineural windows on the peroneal and tibial nerve at the right side in an end‐to‐side fashion. To create neurotrophic stimulus, partial incision was performed on the nerves in group I, and gene therapy was performed by plasmid injecting to the adjacent muscles in group II. At the end of the eighth week, prefabricated nerve grafts, jugular vein, and the axons passing through it were taken. Then, gap was created on the left peroneal nerve in all groups. Defect on the peroneal nerve was repaired by using the prefabricated nerve grafts in groups I and II, the autogenous nerve graft in group III, and the vein in group IV. Assessment of nerve regeneration was performed by using electromyography. Morphological assessment was performed after follow‐up period. According to electrophysiological and morphological results, the results of first three groups were similar. There was no statistically significant difference between three groups. Prefabricated nerve graft is as effective as autogenous nerve graft, and it can be used in the repair of nerve defects as autogenous nerve graft as an alternative. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Investigation of reperfusion injury and ischemic preconditioning in microsurgery
Authors: Wang Wei Zhong
Published: October 2008

Ischemia/reperfusion (I/R) is inevitable in many vascular and musculoskeletal traumas, diseases, free tissue transfers, and during time‐consuming reconstructive surgeries in the extremities. Salvage of a prolonged ischemic extremity or flap still remains a challenge for the microvascular surgeon. One of the common complications after microsurgery is I/R‐induced tissue death or I/R injury. Twenty years after the discovery, ischemic preconditioning has emerged as a powerful method for attenuating I/R injury in a variety of organs or tissues. However, its therapeutic expectations still need to be fulfilled. In this article, the author reviews some important experimental evidences of I/R injury and preconditioning‐induced protection in the fields relevant to microsurgery. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Indications and outcomes of double free flaps in head and neck reconstruction
Authors: Andrades Patricio , Bohannon Isaac A. , Baranano Chris F. , Wax Mark K. , Rosenthal Eben
Published: October 2008

Objective. This study describes the clinical setting and operative outcomes for simultaneous double free flap treatment of extensive composite head and neck cancers. Methods. A retrospective review at two tertiary referral centers was performed. Patient demographics, cancer characteristics, reconstruction methods, and postoperative course were recorded. All patients were assessed for diet, speech, esthetics, socialization, and satisfaction using specific evaluation scales. Results. A total of 30 patients underwent double free flap reconstruction between 2001 and 2007. There were 19 men and 11 women, mean age of 62 years (range, 42–79). Comorbidities were present in 67% of the cases and 70% smoked. Most frequently the cancer was a squamous cell carcinoma (90%), in advanced stage (87%), and recurrent (67%), affecting the oral cavity (43%), larynx (23%) or pharynx (20%). The fibula osteoseptocutaneous/radial forearm fasciocutaneous flap combination was most commonly used (n = 13), followed by the jejunum‐radial forearm flap (n = 10). Three flaps required early anastomosis revision and only two partial flap losses were observed. In 11 cases, there was a severe recipient site complication: wound dehiscence (n = 3), oral incompetence (n = 4), fistula (n = 2), and stenosis (n = 2). Two patients died in the postoperative period due to medical problems (7%). The mean follow up was 15.3 months. Patient satisfaction was poor to moderate and the overall functional evaluation score was low. Conclusions. Double free flaps for one‐stage reconstruction of extensive head and neck defects should be used in selected cases. Although a reliable procedure, immediate postoperative morbidity and mortality is high, and the long‐term functional and esthetic results are modest. Realistic outcomes should be discussed with patients during planning and consent. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
The preparation of biodegradable polyurethane/carbon nanotube composite based on in situ cross‐linking
Authors: Song Wen‐Hui , Ni Qiu‐Ping , Zheng Zhen , Tian Li‐Ying , Wang Xin‐Ling
Published: October 2008

A biodegradable polyurethane (PU)/carbon nanotube (CNT) composite was prepared by bulk polymerization based on in situ cross‐linking of hydroxyl‐terminated polylactic acid functionalized CNTs. As parallel experiments, PU/CNT blend and pure PU were prepared. The obtained products were characterized by Fourier transform infrared (FTIR), thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC), hydrogen nuclear magnetic resonance (1H NMR) and field emission scanning electron microscopy (FESEM). The properties and morphology of composites were discussed including both blending and cross‐linking composites. The results showed that the functionalized CNTs were dispersed well in the PU matrix, and its initial thermal decomposition temperature was higher than that of the blend. Copyright © 2008 John Wiley & Sons, Ltd.
Toughening modification of PLLA/PBS blends via in situ compatibilization
Authors: Wang Ruyin , Wang Shifeng , Zhang Yong , Wan Chaoying , Ma Piming
Published: October 2008

Biodegradable polymer blends consisting of poly(L‐lactic acid) (PLLA) and poly(butylene succinate) (PBS) were prepared in the presence of dicumyl peroxide (DCP). The effects of DCP content on the mechanical properties, thermal and rheological behavior, phase morphology as well as the toughening mechanism of the blends were investigated. The notched Izod impact strength of PLLA/PBS (80/20) blend significantly increased after the addition of 0.05–0.2 phr DCP, but the strength and modulus monotonically decreased with increasing DCP content. PBS acted as a nucleating agent at the environmental temperature below its melting temperature and accelerated the crystallization rate of PLLA but had little effect on its final degree of crystallinity. The degree of crystallinity of PBS and the cold crystallization ability of PLLA gradually reduced with increasing DCP content. The addition of DCP induced an increase in viscosity of the blends at low frequencies as well as finer dispersion of PBS particles and better interfacial adhesion between PLLA and PBS, indicating the in situ compatibilization occurred between the two components. The optical clarity of PLLA/PBS blends was significantly improved after the addition of DCP, which was in accordance with the crystallization behavior and phase structure of the blends. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Generation of low‐density high‐performance poly(arylene ether sulfone) foams using a benign processing technique
Authors: VanHouten Desmond J. , Baird Donald G.
Published: October 2008

In this study, a benign process was used to successfully produce low density foam from poly(arylene ether sulfone) (PAES). Both carbon dioxide (CO2) and water as well as nitrogen and water were used as physical blowing agents in a one‐step batch process. A large amount of blowing agents (up to 7.5%) was able to diffuse into the PAES resin in a 2‐h saturation time. Utilizing water and CO2 as the blowing agents yielded foam with better properties than nitrogen and water because both the water and CO2 are plasticizers for the PAES resin. PAES foam produced from CO2 and water had a large reduction in foam density (∼80%) and a cell size of ∼50 μm, while maintaining a primarily closed cell structure. The small cell size and closed cell structure enhanced the mechanical properties of the foam when compared with the PAES foam produced from nitrogen and water. The tensile, compressive, and notched izod impact properties of the PAES foams were examined, and the compressive properties were compared to commercially available structural foams. With reduced compression strength of 39 MPa and reduced compression modulus of 913 MPa, the PAES foam is comparable to polyetherimide and poly(vinylchloride) structural foams. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Nonlinear optical studies of newly synthesized polythiophenes containing pyridine and 1,3,4‐oxadiazole units
Authors: Poornesh P. , Hegde P.K. , Manjunatha M.G. , Umesh G. , Adhikari A.V.
Published: October 2008

We report measurements of the third‐order nonlinear optical properties of a newly synthesized thiophene‐based copolymer. The nonlinear transmission measurements were performed on the copolymer dissolved in tetrahydrofuran by employing the single beam Z‐scan technique. Q‐switched laser output at 532‐nm wavelength was used for this purpose. The nonlinear absorption coefficient, β, nonlinear refractive index, n2, and the real and imaginary parts of third‐order susceptibility, χ(3), were, 18.93 cm/GW, 3.037 × 10−17 m2/W (−1.022 × 10−10 esu), 1.512 × 10−20 m2/V2(−1.080 × 10−12 esu) and 0.399 × 10−20 m2/V2 (0.285 × 10−12 esu), respectively. The excited state absorption crosssection σexc, was found to be larger than the ground state absorption crosssection σg, indicating reverse saturable absorption (RSA) in the copolymer sample. The copolymer exhibits an optical power limiting threshold of about 120 μJ and saturated output of less than 80 μJ. Hence, the copolymer seems to be a promising material for photonic device applications. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Tailoring properties of styrene butadiene rubber nanocomposite by various nanofillers and their dispersion
Authors: Bhattacharya Mithun , Maiti Madhuchhanda , Bhowmick Anil K.
Published: October 2008

Organic–inorganic nanocomposite hybrids of styrene butadiene rubber were prepared with various nanofillers like modified and unmodified montmorillonite, sepiolite (SP), hectorite, carbon nanofiber (F), and expanded graphite. Comparison of the nanocomposites against the gum on the basis of mechanical properties illustrates that Cloisite15A (15A) produced an increment of 230% in the tensile strength (TS), at 8 phr loading. At 6 phr loading, F increased the modulus by 101%, while tear strength increased by 79%. Once optimized for loading, these nanocomposites were subjected to various compatibilization and dispersion techniques to achieve enhanced dispersion of the nanofillers. On modification, 15A registered 146% increase in modulus and 303% in TS, while F illustrated 150% increment in modulus and 113% in TS of the nanocomposite, over the gum control. Thorough dynamic mechanical and swelling studies were also performed. X‐ray diffraction, atomic force microscopy and transmission electron microscopy were used to study the morphology. The London dispersive forces explained the enhanced properties on using carbon nanofiber, while the wider gallery gap and increased compatibility because of high organo‐modifier content explicated the efficacy of 15A. Adsorption followed by shearing as well as intercalation of the rubber into clay layers were suggested as the probable mechanisms. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Relationship between hot flashes and distress in men receiving androgen deprivation therapy for prostate cancer
Authors: Ulloa Erin Winters , Salup Raoul , Patterson Stephen G. , Jacobsen Paul B.
Published: October 2008

Objective: Side effects of cancer treatment have been found to have a significant impact on patients' psychological well‐being. Each of the primary treatment options for prostate cancer is associated with significant side effects that can have a dramatic impact on quality of life. Hot flashes are a notable side effect of androgen deprivation therapy (ADT) and a potential source of distress due to their episodic nature and low frequency in a normal aging male population. The current study sought to examine the relationship between hot flashes and cancer‐related distress during the first three months of ADT.

Methods: Participants were 68 men with various stages of prostate cancer scheduled to begin ADT for the first time. Study measures were completed at the beginning of treatment and 3 months later.

Results: Repeated measures ANOVA indicated that men who did not experience hot flashes had a significant decrease in total cancer‐related distress and avoidance over the 3‐month period, while men with hot flashes exhibited no change in distress. Among men with hot flashes, results of hierarchical regression analyses indicated that a worse experience with hot flashes was a significant predictor of greater increases in intrusion and total cancer‐related distress over the 3‐month period.

Conclusions: These results suggest that hot flashes serve to maintain levels of distress during the treatment period. Further research should extend these findings by lengthening the follow‐up period and using ecological momentary assessment to refine measurement of these constructs and provide evidence for the direction of causality between hot flashes and distress. Copyright © 2008 John Wiley & Sons, Ltd.
Thermal conductivity of segregated ground ice
Authors: Gavriliev Rev I.
Published: October 2008

The thermal conductivity of segregated ice is theoretically estimated based on a model of porous ice with capillary (continuous) and closed cylindrical pores along the heat flow and with spherical air bubbles, taking into account the additional convective heat transfer by vapour diffusion in the bubbles. Calculations can be made on the basis of the Maxwell‐Rayleigh theory. It is shown that the calculated values of thermal conductivity for segregated ice are much higher than some previously published experimental values, probably due to some methodological shortcomings in the calculation and/or in the earlier experiments. Copyright © 2008 John Wiley & Sons, Ltd.
The Effect of Illumination Wavelength on the Measurement of Size Distribution of Very Small Particles Using a Novel Imaging Based System
Authors: Carter Robert M. , Yan Yong
Published: October 2008

This paper presents the results of an experimental investigation into the importance of illumination wavelength on measurement accuracy for an existing digital imaging based particle size analyzer. When the system was originally developed fairly large particles were interrogated rendering the effects of illumination wavelength insignificant, but recent work has suggested that there is an interest in the scientific community in analysing particles down to a few microns in size. At these scales illumination wavelengths and particle size are of similar magnitudes, possibly leading to problems. The work presented in this paper is intended to be a practical investigation into wavelength effects using the existing system. This aim has been met firstly by introducing the basic system, along with some key past results and accuracy, then moving on to explain the wavelength tests and present new results. Two sources of illumination were used – red and blue (625 and 470 nm). Polymer micro‐spheres in the 2.5–100 μm range, calibrated to NIST (National Institute of Standards and Technology) standards, were interrogated under static conditions. It is shown that whilst blue illumination does give an increase in accuracy the effect is not marked enough to preclude the use of cost‐effective red illumination at these scales.
Analysis of the human testis proteome by mass spectrometry and bioinformatics
Authors: Guo Xuejiang , Zhang Ping , Huo Ran , Zhou Zuomin , Sha Jiahao
Published: October 2008

The testis is a unique organ responsible for sperm production and androgen secretion in men. To analyze the human testis proteome on a large scale, 1‐D SDS‐PAGE and RP‐LC‐MS/MS were applied and 1430 proteins in the human testis were identified. Both the false‐positive rate of peptides and protein identification confidence scores were calculated in the present study. Subsequent bioinformatics analysis of the human testis proteome revealed 39 testis‐specific proteins which may be important for testis functions. And a large family of proteins were identified possibly involved in alternative splicing, which may also be involved in testis‐specific splicing events and explain why splicing is so prevalent in the testis. Compared with the studies on brain proteome, researches on the testis proteome is still very limited. Studies of these proteins will give a better understanding on the function of the testis. Moreover, this large‐scale identification of testis proteins in humans could serve as a reference for future studies on the mechanisms underlying male infertility, searching for potential contraceptive targets, and developing new treatments for testis cancer.
Age‐dependent gene expression profile and protein expression in a transgenic rat model of Huntington's disease
Authors: Nguyen Huu Phuc , Metzger Silke , Holzmann Carsten , Koczan Dirk , Thiesen Hans‐Jürgen , von Hörsten Stephan , Riess Olaf , Bonin Michael
Published: October 2008

Polyglutamine‐induced changes in gene expression have been demonstrated by using several mouse models of Huntington's disease (HD), which express extreme numbers of CAG repeats. We have recently developed a transgenic rat model of HD carrying a truncated huntingtin fragment with 51 CAG repeats, which is in the range seen in adult HD patients. For further evaluation, we have performed microarray analyses on whole brains of transgenic rats at 3 and 12 months of age and correlated it with protein expression by Western blot analysis. We found that genes functionally associated with gene expression and behavior were differently regulated already at 3 months of age, whereas at 12 months of age especially genes related to neurological diseases and cell‐to‐cell signaling and interaction were dysregulated. A detailed analysis of canonical pathways revealed that at 3 months of age genes in calcium signaling and synaptic long term potentation pathways were altered, while at 12 months of age, additionally, expression level of many genes implicated in Huntington's disease signaling, were changed.