bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of aging on contact heat‐evoked potentials: The physiological assessment of thermal perception
Authors: Chao Chi‐Chao , Hsieh Sung‐Tsang , Chiu Ming‐Jang , Tseng Ming‐Tsung , Chang Yang‐Chyuan 
Published: May 2007

AbstractAge significantly influences the detection thresholds to noxious heat; such thresholds depend on responses in the cerebral cortex to thermal stimuli and the psychophysical perception of such responses. To understand the influence of age on cerebral responses, we used contact heat‐evoked potentials (CHEPs) to investigate the physiology of cerebral responses to thermal stimuli in 70 healthy subjects (33 men and 37 women, 39.56 ± 12.12 years of age). With heat stimulation of fixed intensity (51°C) on the distal forearm and distal leg, CHEPs revealed consistent waveforms with an initial negative peak (N1 latency: 398.63 ± 28.55 and 449.03 ± 32.21 ms for upper and lower limbs) and a later positive peak (P1 latency: 541.63 ± 37.92 and 595.41 ± 39.24 ms for upper and lower limbs) with N1–P1 interpeak amplitude of 42.30 ± 12.57 μV in the upper limb and 39.67 ± 12.03 μV in the lower limb. On analyses with models of multiple linear regression, N1–P1 amplitudes were negatively correlated with age and N1 latencies were correlated with gender, with females having shorter latencies. The verbal rating scale (VRS) for pain perception was higher in females than males, and decreased with aging. In addition, VRS paralleled changes in N1–P1 amplitude and N1 latency; the higher the VRS, the shorter the N1 latency and the higher the N1–P1 amplitude. These results provide evidence that CHEPs are influenced significantly by aging, corresponding to aging‐related changes in thermal pain perception. Muscle Nerve, 2007
Measurement of cerebral perfusion territories using arterial spin labelling
Authors: Paiva Fernando F. , Tannús Alberto , Silva Afonso C. 
Published: May 2007

AbstractThe ability to assess the perfusion territories of major cerebral arteries can be a valuable asset to the diagnosis of a number of cerebrovascular diseases. Recently, several arterial spin labeling (ASL) techniques have been proposed for determining the cerebral perfusion territories of individual arteries by three different approaches: (1) using a dedicated labeling radio frequency (RF) coil; (2) applying selective inversion of spatially confined areas; (3) employing multidimensional RF pulses. Methods that use a separate labeling RF coil have high signal‐to‐noise ratio (SNR), low RF power deposition, and unrestricted three‐dimensional coverage, but are mostly limited to separation of the left and right circulation, and do require extra hardware, which may limit their implementation in clinical systems. Alternatively, methods that utilize selective inversion have higher flexibility of implementation and higher arterial selectivity, but suffer from imaging artifacts resulting from interference between the labeling slab and the volume of interest. The goal of this review is to provide the reader with a critical survey of the different ASL approaches proposed to date for determining cerebral perfusion territories, by discussing the relative advantages and disadvantages of each technique, so as to serve as a guide for future refinement of this promising methodology. Copyright © 2007 John Wiley & Sons, Ltd.
A proactive management algorithm for self‐healing mobile ad hoc networks
Authors: Iskander Adel F. , Younis Akmal A. 
Published: May 2007

AbstractThe ability to proactively manage mobile ad hoc networks (MANETs) is critical for supporting complex services such as quality of service, security and access control in these networks. This paper focuses on the problem of managing highly dynamic and resource‐constrained MANET environments through the proposal of a novel proactive management algorithm (PMA) for self‐healing MANETs. PMA is based on an effective integration of autonomous, predictive and adaptive distributed management strategies. Proactive management is achieved through the distributed analysis of the current performance of the mobile nodes utilizing an optimistic discrete event simulation method, which is used to predict the mobile nodes' future status, and execution a proactive fault‐tolerant management scheme. PMA takes advantage of distributed parallel processing, flexibility and intelligence of active packets to minimize the management overhead, while adapting to the highly dynamic and resource‐constrained nature of MANETs. The performance of the proposed architecture is validated through analytical performance analysis and comparative simulation with the Active Virtual Network Management Protocol. The simulation results demonstrate that PMA not only significantly reduces management control overhead, but also improves both the performance and the stability of MANETs. Copyright © 2007 John Wiley & Sons, Ltd.
Using temporal correlation for fault localization in dynamically changing networks
Authors: Natu Maitreya , Sethi Adarshpal S. 
Published: May 2007

AbstractA mobile ad hoc network creates a dynamic environment where node mobility can cause periodic changes in routes. Most existing fault localization algorithms assume availability of a complete and/or deterministic dependency model. Such assumptions cannot be made in the dynamically changing networks. This paper is aimed at developing a fault diagnosis architecture and algorithm to address the issue of dynamically changing dependencies in networks. We propose an architecture to capture the changes in dependencies and introduce a temporal correlation algorithm to perform fault diagnosis with the dynamically changing dependency information. We present an experimental evaluation of our work through simulation results using Qualnet. Copyright © 2007 John Wiley & Sons, Ltd.
Overexpression of the αvβ6 integrin in cervical squamous cell carcinoma is a prognostic factor for decreased survival
Authors: Hazelbag S , Kenter GG , Gorter A , Dreef EJ , Koopman LA , Violette SM , Weinreb PH , Fleuren GJ 
Published: May 2007

AbstractCervical squamous cell carcinomas are composed histologically of tumour cell islands surrounded by varying amounts of tumour stroma, the amount and composition of which are influenced by local TGF‐β1. TGF‐β1 is secreted in an inactive complex with latency‐associated peptide (LAP). Both LAP and the extracellular matrix (ECM) protein fibronectin are important ligands for the integrin receptor αvβ6. While αvβ6 is only weakly expressed by normal epithelia, it is up‐regulated in different carcinomas where it generally reflects a more aggressive phenotype. In cervical cancer, the expression of αvβ6 has not thus far been investigated. Given the ability of αvβ6 both to activate TGF‐β1 and to interact with fibronectin, we studied correlations between the expression of these components and disease parameters in a large cohort of cervical cancer specimens. We analysed αvβ6 expression using immunohistochemistry in primary cervical squamous carcinomas of FIGO stage IA to IIB patients and correlated the findings with formerly investigated fibronectin and TGF‐β1 expression and clinico‐pathological parameters. αvβ6 expression was also examined in cervical intra‐epithelial neoplasia (CIN) and lymph node metastases. αvβ6 was only weakly expressed in normal epithelium but clearly up‐regulated in CIN lesions. In carcinomas, strong expression of αvβ6 in tumour cells correlated with different clinico‐pathological parameters and with worse overall and disease‐free survival. Furthermore, αvβ6 expression correlated positively with TGF‐β1 mRNA expression as well as with fibronectin expression. Overexpression of αvβ6 in cervical squamous carcinomas is an unfavourable prognostic factor. This might reflect an increased capacity of αvβ6‐expressing tumour cells to migrate in a fibronectin‐rich ECM and/or to activate TGF‐β1 at the tumour/stroma interface, both of which processes may contribute to cervical cancer progression. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Neuropilins in physiological and pathological angiogenesis
Authors: Staton CA , Kumar I , Reed MWR , Brown NJ 
Published: May 2007

AbstractNeuropilin‐1 (Np1) and neuropilin‐2 (Np2) are transmembrane glycoproteins with large extracellular domains that interact with both class 3 semaphorins and vascular endothelial growth factor (VEGF), and are involved in the regulation of many physiological pathways, including angiogenesis. The neuropilins also interact directly with the classical receptors for VEGF, VEGF‐R1 and ‐R2, mediating signal transduction. The heart, glomeruli and osteoblasts express both Np1 and Np2, but there is differential expression in the adult vasculature, with Np1 expressed mainly by arterial endothelium, whereas Np2 is only expressed by venous and lymphatic endothelium. Both neuropilins are commonly over‐expressed in regions of physiological (wound‐healing) and pathological (tumour) angiogenesis, but the signal transduction pathways, neuropilin‐mediated gene expression and the definitive role of neuropilins in angiogenic processes are not fully characterized. This review details the current evidence for the role of neuropilins in angiogenesis, and suggests future research directions that may enhance our understanding of the mechanisms of action of this unique family of proteins. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Prenatal ultrasound diagnosis of vasa praevia and analysis of risk factors
Authors: Baulies S. , Maiz N. , Muñoz A. , Torrents M. , Echevarría M. , Serra B. 
Published: May 2007

AbstractObjectiveTo evaluate the role of ultrasound in prenatal diagnosis of vasa praevia (VP) and to asses the risk of VP associated with different causal factors.Material and MethodsA retrospective study of the incidence of VP in a series of 12 063 deliveries between January 2000 and March 2005. We also studied the factors that predisposed for VP and the perinatal outcome of pregnancies.ResultsThe prevalence of VP in our centre during this period was 0.07% (9 cases). All cases were prenatally diagnosed. The mean gestational age at diagnosis was 26 weeks. Multivariate analysis revealed the following associated factors: IVF pregnancies, bilobate or succenturiate placenta, and second‐trimester placenta praevia, with an odds ratio of 7.75, 22.11 and 22.86, respectively.ConclusionsIn our series, the prenatal diagnosis of all cases of VP achieved during the second‐trimester scan allowed us to avoid any prenatal death related to this condition. Copyright © 2007 John Wiley & Sons, Ltd.
Diagnosis of Apert syndrome in the second‐trimester using 2D and 3D ultrasound
Authors: David A. L. , Turnbull C. , Scott R. , Freeman J. , Bilardo C. M. , van Maarle M. , Chitty L. S. 
Published: May 2007

AbstractObjectivesTo illustrate how Apert syndrome, a rare autosomal dominant genetic syndrome, can be detected in the second‐trimester of pregnancy using 2D ultrasound, and how 3D ultrasound examination may provide parents with a better understanding of the structural defects affecting their baby.MethodsFetal Medicine Unit database searches to identify Apert syndrome cases.ResultsFive cases of Apert syndrome were suspected in the second‐trimester when sonography showed abnormal extremities including syndactyly, and an abnormal skull shape. In 1 case there was increased nuchal translucency with a normal fetal karyotype in the first‐trimester. In all cases, a mutation of the FGFR2 gene confirmed the diagnosis of Apert syndrome. 3D ultrasound was used to show parents the extent of the abnormalities of the skull, face and extremities. Parents were counseled by craniofacial surgeons and geneticists.ConclusionApert syndrome can be accurately suspected in the second‐trimester by careful ultrasound examination of the fetus including the extremities and skull shape. 3D ultrasound can be a useful adjunct to 2D examination for parental counseling. Copyright © 2007 John Wiley & Sons, Ltd.
Star‐shaped alkylated poly(glycerol methacrylate) reverse micelles: Synthesis and evaluation of their solubilizing properties in dichloromethane
Authors: Gao Hui , Jones Marie‐Christine , Tewari Pankaj , Ranger Maxime , Leroux Jean‐Christophe 
Published: May 2007

AbstractAmphiphilic star‐shaped polymers were synthesized by atom transfer radical polymerization (ATRP). Four‐, 5‐, and 6‐arm ATRP initiators were prepared and used to polymerize glycidylmethacrylate. The resulting polymers were hydrolyzed to yield poly(glycerolmethacrylate)s (PGOHMAs), and then partially esterified with lauroyl or stearoyl chloride (40–60 mol % vs. hydroxyl groups). Alkylated PGOHMAs were found to assemble into 20–60 nm aggregates in dichloromethane (DCM) above a critical concentration. Particle size essentially depended on the branching degree of the polymer. The micelles were extremely efficient in extracting Congo red from water into DCM, with the highest incorporations (97 mg/g) obtained for the 6‐arm polymer modified with stearoyl chloride (60 mol %). The entrapment efficiency for the latter was further improved in alkaline solution. The high level of incorporation achieved for these amphiphilic multiarm polymers suggests that such reverse micelles could be potentially useful as drug delivery systems and nanoreactors in catalytic organic reactions or for water purification. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2425–2435, 2007
Controlled photopolymerization reactions: The reactivity of new photoiniferters
Authors: Lalevée J. , El‐Roz M. , Allonas X. , Fouassier J. P. 
Published: May 2007

AbstractFour new structures (o,o‐diethyl dithiobisthioformate, isopropylxanthic disulfide, tetramethyldicarbonotrithioic diamide, and phenylacetyl disulfide) are proposed as photoiniferters for controlled photopolymerization reactions. Their photochemical properties, efficiency in controlling the photopolymerization of methyl methacrylate (MMA), and ability to photocrosslink a difunctional acrylate monomer [1,6‐hexane diol diacrylate (HDDA)] are investigated. The rates of polymerization of MMA and HDDA and the number‐average molecular weights (Mn's) and polydispersity indices (PDIs) of poly(methyl methacrylate) have been determined. The transient absorption spectra and interaction rate constants of the radicals have been measured. Both the (alkyloxythiocarbonyl)thiyl and (benzylcarbonyl)thiyl radicals are efficient in controlling a photopolymerization process. For a 40% monomer conversion obtained in a few minutes, the Mn values range from 6000 to 14,000, and the PDIs can reach 1.6–2.2. A fivefold reduction of the light intensity increases Mn by 25% and reduces PDI by 5%. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2436–2442, 2007
Stereoregular P(MMA)‐clay nanocomposites by metallocene catalysts: In situ synthesis and stereocomplex formation
Authors: Mariott Wesley R. , Escudé Nicole C. , Chen Eugene Y.‐X. 
Published: May 2007

AbstractThis contribution reports the synthesis and characterization of stereochemically controlled, as well as crystalline stereocomplex, P(MMA)‐clay nanocomposites using metallocene complexes and alane‐intercalated clay activators. The ligand elimination and exchange reactions involving Lewis acids E(C6F5)3 (E = Al, B) and an organically modified montmorillonite clay were employed to synthesize the alane‐intercalated clay activators. When combined with dimethyl metallocenes of various symmetries, these clay activators brought about efficient MMA polymerizations leading to in situ polymerized, stereochemically controlled P(MMA)‐intercalated clay nanocomposites. The most noticeable thermal property enhancement observed for the clay nanocomposite P(MMA), when compared with the pristine P(MMA) having similar molecular weight and stereomicrostructure, has a considerable increase in Tg (≥10 °C). Mixing of dilute THF solutions of two diastereomeric nanocomposites in a 1:2 isotactic to syndiotactic ratio, followed by reprecipitation or crystallization procedures, yielded unique double‐stranded helical stereocomplex P(MMA)‐clay nanocomposites with a predominantly exfoliated clay morphology. Remarkably, the resulting crystalline stereocomplex P(MMA) matrix is resistant to the boiling‐THF extraction and its clay nanocomposites exhibit high Tm of 201 to 210 °C. Furthermore, the stereocomplex P(MMA)‐clay nanocomposite shows a one‐step, narrow decomposition temperature window and a single, high maximum rate decomposition temperature of 377 °C. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2581–2592, 2007
Detection of colorectal adenoma and cancer based on transthyretin and C3a‐desArg serum levels
Authors: Fentz Anne‐Kristin , Spörl Monika , Spangenberg Jörg , List Heinz Joachim , Zornig Carsten , Dörner Arnulf , Layer Peter , Juhl Hartmut , David Kerstin A. 
Published: May 2007

AbstractColorectal cancer is the second leading cause of cancer death, and it develops from benign colorectal adenomas in over 95% of patients. Early detection of these cancer precursors by screening tests and their removal can potentially eradicate more than 95% of colorectal cancers before they develop. To discover sensitive and specific biomarkers for improvement of pre‐clinical diagnosis of colorectal adenoma and cancer, we analysed in two independent studies (n = 87 and n = 83 patients) serum samples from colorectal cancer (stage III), colorectal adenoma and control patients using SELDI‐TOF‐MS. Extensive statistical analysis was performed to establish homogeneous patient groups based on their clinical data. Two biomarkers that were each able to distinguish control patients from either colorectal adenoma or colorectal cancer patients (p<0.001) were identified as transthyretin (pre‐albumin) and C3a‐desArg by MS/MS and were further validated by antibody‐based assays (radial immunodiffusion, ELISA). A combination of both proteins clearly indicated the presence of colorectal adenoma or carcinoma. Using a cut‐off of <0.225 g/L for transthyretin and >1974 ng/mL for C3a‐desArg, we found a sensitivity and specificity for colorectal adenoma of 96% and 70%, respectively.
Prostate stem cell antigen (PSCA) mRNA expression in prostatic intraepithelial neoplasia: implications for the development of prostate cancer
Authors: Zhigang Zhao , Wenlu Shen 
Published: May 2007

AbstractBACKGROUNDPrior data clearly demonstrated the expression of prostate stem cell antigen (PSCA) mRNA in prostatic intraepithelial neoplasia (PIN) tissues. The purpose of the present investigation was to determine whether PSCA mRNA expression was associated with the presence of cancer in this disease.METHODSOne hundred seventeen men were diagnosed with isolated PIN on initial prostate biopsy, 51 with low‐grade form (LGPIN), and 66 with high‐grade form (HGPIN). PSCA mRNA expression in initial PIN and subsequent cancer was examined by in situ hybridization (ISH). The differences of the PSCA mRNA expression level between the groups were analyzed by the Chi‐square and Student's t‐test. Univariate and multivariate logistic regression analyses were performed to evaluate the predictive performance of PSCA mRNA.RESULTSPSCA mRNA expression level in 34 subsequent cancers was statistically increased compared with their paired PIN (P < 0.001), with a Gleason's dependence. HGPIN showed statistically high PSCA mRNA expression compared with LGPIN (P < 0.01). PSCA mRNA expression levels were significantly stronger in the initial isolated LGPIN and isolated HGPIN with subsequent cancer than those without (P < 0.001 and P < 0.001, respectively). Multivariate logistic regression analysis demonstrated that only PSCA mRNA was predictive of the onset of subsequent cancer in patients with isolated LGPIN and in those with isolated HGPIN, respectively.CONCLUSIONSOur data identify PSCA mRNA in initial PIN as a significant predictor of subsequent cancer, suggesting that PSCA implies in prostatic tumorigenesis and may be used to identify the patients with isolated PIN who are at high risk for cancer onset in the disease process. Prostate 67: 1143–1151, 2007. © 2007 Wiley‐Liss, Inc.
On the wind power rejection in the islands of Crete and Rhodes
Authors: Katsaprakakis Dimitris Al. , Papadakis Nikos , Christakis Dimitris G. , Zervos Arthouros 
Published: May 2007

AbstractCrete and Rhodes represent the two biggest isolated power systems in Greece. The energy production in both islands is based on thermal power plants. The annual wind energy rejection percentage is calculated for Crete and Rhodes in this paper. The rejected wind energy is defined as the electric energy produced by the wind turbines and not absorbed by the utility network, mainly due to power production system's stability and dynamic security reasons. A parametric calculation of the annual wind energy rejection percentage, in terms of the installed wind power, the power demand and the maximum allowed wind power instant penetration percentage, is accomplished. The methodology takes into account (i) the wind power penetration probability, restricted by the thermal generators technical minima and the maximum allowed wind power instant penetration percentage over the instant power demand; and (ii) the wind power production probability, derived by the islands' wind potential. The present paper indicates that isolated power systems which are based on thermal power plants have a limited wind power installation capacity—in order to achieve and maintain an adequate level of system stability. For a maximum wind power instant penetration percentage of 30% of the power demand, in order to ensure an annual wind energy rejection percentage less than 10%, the total installed wind power should not exceed the 40% of the mean annual power demand. The results of this paper are applicable to medium and great size isolated power systems, with particular features: (i) the power production is based on thermal power plants; (ii) the power demand exhibits intensive seasonal variations and is uncorrelated to the wind data; (iii) the mean annual power demand is greater than 10MW; and (iv) a high wind potential, presenting mean annual wind velocity values greater than 7·5ms−1, is recorded. Copyright © 2007 John Wiley &Sons, Ltd.
Landscape structure affects food quality of sika deer (Cervus nippon) evidenced by fecal nitrogen levels
Authors: Miyashita Tadashi , Suzuki Maki , Takada Mayura , Fujita Go , Ochiai Keiji , Asada Masahiko 
Published: May 2007

AbstractEvaluating the quality of wildlife habitat is essential for understanding and predicting population dynamics in heterogeneous environments. We used fecal nitrogen levels as an indicator of habitat quality of sika deer (Cervus nippon) and explored important landscape elements influencing nitrogen levels, taking deer density into account. We established 92 plots differing in deer density and landscape structure on the Boso Peninsula, central Japan, and collected fecal samples along a 1‐km transect at each plot. The regression models involving two independent variables, i.e., deer density and the length of forest edge within an area of 100 or 200 m from the transect, were selected based on the Akaike's Information Criterion (AIC). Levels of fecal nitrogen were positively correlated with the length of the forest edge and negatively correlated with population density of deer. The area of 100 or 200 m from the transect most likely reflected the behavioral scale of the deer. Coverage of palatable understory vegetation increased with proximity to forest edge and decreased with deer density. Variability in the level of fecal nitrogen could thus be explained by food availability in the landscape. These results suggest that landscape alterations increase the carrying capacity of sika deer and thereby increase impacts upon the ecosystem.