bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of techniques for obtaining continuous models from 2D discrete reduced‐order state‐space CFD models
Authors: Gaitonde Ann L. , Jones D. P. 
Published: June 2006

AbstractThe application of unsteady computational fluid dynamics (CFD) codes to aeroelastic calculations leads to a large number of degrees of freedom making them computationally expensive. Reduced‐order models (ROMs) have therefore been developed; an ROM is a system of equations which is able to reproduce the solutions of the full set of equations with reasonable accuracy, but which is of lower order. ROMs have been the focus of research in various engineering situations, but it is only relatively recently that such techniques have begun to be introduced into CFD. In order for the reduced systems to be generally applicable to aeroelastic calculations, it is necessary to have continuous time models that can be put into discrete form for different time steps. While some engineering reduction schemes can produce time‐continuous models directly, the majority of methods reported in CFD initially produce discrete time or discrete frequency models. Such models are restricted in their applicability and in order to overcome this situation, a continuous time ROM must be extracted from the discrete time system. This process can most simply be achieved by inverting the transformation from continuous to discrete time that was initially used to discretize the CFD scheme. However an alternative method reported in literature is based on continuous time sampling, even when this is not used for the initial discretization of the CFD code. This paper focuses on one particular method for ROM generation, eigensystem realization algorithm (ERA), that has been used in the CFD field. This is implemented to produce a discrete time ROM from a standard CFD code, that can be used to investigate methods for obtaining continuous ROMs and the limitations of the resulting models. Copyright © 2006 John Wiley & Sons, Ltd.
Resection of selected invasive squamous cell carcinoma of the pyriform sinus by means of the lateral pharyngotomy approach: The partial lateral pharyngectomy
Authors: Holsinger F. Christopher , Motamed Mehdi , Garcia Dominique , Brasnu Daniel , Ménard Madeleine , Laccourreye Ollivier 
Published: June 2006

AbstractBackground.Although the lateral pharyngotomy is a well‐known surgical procedure, to our knowledge, no published reports have described the results achieved with a lateral pharyngectomy approach in patients with isolated and previously untreated selected invasive squamous cell carcinoma of the lateral wall of the pyriform sinus.Methods.The medical files and operative charts of 30 patients with an isolated, and previously untreated, squamous cell carcinoma of the pyriform sinus, treated for cure by lateral partial pharyngectomy and primary closure, as well as postoperative radiotherapy (n = 22), and preoperative chemotherapy (n = 8), were retrospectively studied. Sixteen tumors were classified as T1 and 14 as T2. All patients but one were followed until death.Results.Three patients (9%) died in the immediate postoperative period (two from medical complications and one from a surgery‐related complication). Overall, 29 patients died, resulting in a 77.7%, 40%, 23.3%, and 15% 1‐, 3‐, 5‐ and 10‐year Kaplan–Meier actuarial survival estimate, respectively. Only one patient had a serious postoperative complication develop. All patients were decannulated. No patients required a gastrostomy and/or completion total laryngectomy for functional reasons. Local recurrence occurred in four patients (13%). The 3‐and 5‐year Kaplan–Meier actuarial local control estimates were 88.5% and 79.6%, respectively. The use of a platin‐based induction chemotherapy (p = .05) regimen was the only variable that was significantly statistically related to local recurrence. Overall, a 93.3% laryngeal preservation rate was achieved.Conclusion.Partial pharyngectomy by means of the lateral pharyngotomy combined with postoperative radiation therapy is an efficient and function‐sparing approach to control selected invasive squamous cell carcinomas of the lateral wall of the pyriform sinus. © 2006 Wiley Periodicals, Inc. Head Neck, 2006
p53‐mediated enhancement of radiosensitivity by selenophosphate synthetase 1 overexpression
Authors: Chung Hyun Ju , Yoon Sun Il , Shin Sun Hye , Koh Yeon A. , Lee Su‐Jae , Lee Yun‐Sil , Bae Sangwoo 
Published: June 2006

AbstractSelenium has been associated with cancer prevention. Despite vast knowledge of selenium effect on various health conditions, functional characterization of selenium metabolic enzymes on cellular physiology has been limited. Therefore, to gain insight into the mechanisms underlying cancer prevention by selenium, we investigated sps1, one of the two human selenophosphate synthetase genes for its role in cancer cell's response to ionizing radiation. Although stable expression of Sps1 protein per se had little effect on cell proliferation, concurrent irradiation decreased viability of the sps1 cell line. The increased sensitivity of the cell lines to ionizing radiation was correlated with increased p53 activity as well as with simultaneous up‐ and downregulation of Bax and Bcl2, respectively. Knockdown of sps1 and p53 by small interfering RNA method revealed that the level of p53 was proportional to that of Sps1 and that the increased radiosensitivity was dependent upon p53. Sps1 cell lines displayed decreased level of reactive oxygen species (ROS) with concomitant increase of certain redox enzymes. Furthermore, p53 activity was regulated by cellular redox via Ref1 in sps1 cell lines. Collectively, our results demonstrated that sps1 was able to affect cell viability upon ionizing radiation via modulation of p53 activity. They further suggest that Sps1 and its reaction product selenophosphate might be involved in cancer prevention in a p53‐dependent manner and could be applied to development of a novel cancer therapy. J. Cell. Physiol. 209: 131–141, 2006. © 2006 Wiley‐Liss, Inc.
B1 field, SAR, and SNR comparisons for birdcage, TEM, and microstrip coils at 7T
Authors: Wang Chunsheng , Shen Gary X 
Published: June 2006

AbstractPurposeTo compare the performance of birdcage, transverse electromagnetic (TEM) and microstrip volume coils at 7T under the same geometric conditions.Materials and MethodsBirdcage, TEM, and microstrip coils are modeled with the same dimensions. The finite difference time domain (FDTD) method is adopted to calculate the electromagnetic fields of the coils. Further, B1 field, specific absorption rate (SAR) and signal‐to‐noise ratio (SNR) are calculated for these coils.ResultsIn the unloaded case, within the central axial plane, the variation of B1 field magnitude over 18‐cm distance is about 15% for the birdcage coil, 23% for the TEM coil, and 38% for the microstrip coil. In the loaded case, the percentages of the samples on the central axial plane, which have B1 field magnitude within ±20% of the average B1 field magnitude, are about 57% for the birdcage, 72% for the TEM, and 59% for the microstrip coil. Average SAR levels are 11.4% and 42.9% higher in the birdcage than those in the TEM and microstrip coils, respectively. The average relative SNR on the central axial plane for the shielded birdcage, TEM, and microstrip coils are 1, 1.07, and 1.48, respectively.ConclusionThe birdcage coil has the best unloaded B1 field homogeneity, and the TEM coil has the best loaded B1 field homogeneity and the lowest radiation loss; while the microstrip coil is better in SAR and SNR at 7T than the birdcage and TEM coils. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Dynamic pulmonary perfusion and flow quantification with MR imaging, 3.0T vs. 1.5T: Initial results
Authors: Nael Kambiz , Michaely Henrik J. , Lee Margaret , Goldin Jonathan , Laub Gerhard , Finn J. Paul 
Published: June 2006

AbstractPurposeTo prospectively evaluate the technical feasibility and relative performance of pulmonary time‐resolved MR angiography (MRA) and pulmonary artery (PA) flow quantification at 3.0T vs. 1.5T.Materials and MethodsTime‐resolved contrast‐enhanced (CE) MRA of the pulmonary circulation, and flow quantification of the main PA (MPA) were performed in 14 consecutive adult healthy volunteers at both 1.5 and 3.0 Tesla with nearly identical sequence parameters. Image quality, signal‐to‐noise ratio (SNR), and quantitative indices of pulmonary perfusion, flow, and velocity were evaluated and compared at both field strengths.ResultsTime‐resolved pulmonary MRA, perfusion, and flow quantification were successfully performed at both magnetic fields. The results of pulmonary perfusion and flow indices were comparable at both magnetic fields, with no statistically significant difference. The SNR values for vascular structures were higher at 3.0T vs. 1.5T (P = 0.001). The SNR values and the definition scores for parenchymal enhancement were significantly lower (P = 0.008 and 0.001, respectively) at 3.0T.ConclusionTime‐resolved pulmonary MRA, perfusion, and flow quantification at 3.0T was feasible, with comparable results to 1.5T. The lower parenchymal enhancement at 3.0T is believed to reflect increased susceptibility effects at higher magnetic fields. Further work is needed to fully exploit the potential of pulmonary perfusion imaging at 3.0T and to address the current limitations. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Feasibility of evaluating Crohn's disease activity at 3.0 Tesla
Authors: van Gemert‐Horsthuis Karin , Florie Jasper , Hommes Daniel W. , Lavini MPhil Cristina , Reitsma Johannes B. , van Deventer Sander J. , Stoker Jaap 
Published: June 2006

AbstractPurposeTo determine whether abdominal 3.0T MRI can be used for evaluation of Crohn's disease (CD) compared with ileocolonoscopy (CS), and to determine patient preference for MRI as opposed to CS.Materials and MethodsTwenty patients scheduled for CS underwent MRI. At CS, disease severity was graded and the Crohn's Disease Endoscopic Index of Severity (CDEIS) was determined. Radiological grading (by two observers) was compared with endoscopic grading and CDEIS. Patient experience and preference were determined.ResultsIn respectively 10 (observer 1) and 13 patients (observer 2) exact agreement between radiological and endoscopic grading was found. In respectively 10 and 7 patients radiological and endoscopic grading differed one level. No statistically significant correlation was found between radiological grading and CDEIS. Between bowel wall thickness and CDEIS weak to moderate correlations were found, and between bowel wall enhancement and CDEIS weak correlations were found. All patients preferred MRI over CS.ConclusionIt is feasible to perform abdominal 3.0T MRI using orally administered contrast medium for evaluation of CD, and this method can be considered a patient‐friendly alternative to CS. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Tensor deflection (TEND) tractography with adaptive subvoxel stepping
Authors: Chou Ming‐Chung , Wu Ming‐Long , Chen Cheng‐Yu , Wang Chao‐Ying , Huang Teng‐Yi , Liu Yi‐Jui , Juan Chun‐Jung , Chung Hsiao‐Wen 
Published: June 2006

AbstractPurposeTo develop an adaptive subvoxel stepping scheme, as an adjunct to tensor deflection (TEND) tractography, that automatically adjusts the stepping size by considering the tensor linearity to properly trace fiber bundles in regions with different degrees of tensor anisotropy.Materials and MethodsA theoretical investigation of the TEND algorithm was performed to assess the degree of deflection of the propagation vector toward the major eigenvector. Mathematically generated phantoms (one with curved fibers and the other with crossing fibers) at wide ranges of signal‐to‐noise ratio (SNR), and human brain images obtained in vivo were used to test the performance of the adaptive stepping algorithm.ResultsThe degree of deflection was found to be inversely related to the stepping size. A small stepping size was advantageous for tracing single curved fiber bundles, whereas a large stepping size was beneficial for passing through fiber crossing regions. The performance of the adaptive stepping algorithm was superior to fixed stepping in both situations, leading to an approximately 0.17 voxel of deviation in curved fibers and a nearly 100% successful tracking rate in crossing fibers at typical SNR. Human brain images demonstrated similar results.ConclusionThe adaptive stepping algorithm is a helpful adjunct to TEND tractography. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Gene delivery to the spinal cord: Comparison between lentiviral, adenoviral, and retroviral vector delivery systems
Authors: Abdellatif Ahmed A. , Pelt Jennifer L. , Benton Richard L. , Howard Russell M. , Tsoulfas Pantelis , Ping Peipei , Xu Xiao‐Ming , Whittemore Scott R. 
Published: June 2006

AbstractViral gene delivery for spinal cord injury (SCI) is a promising approach for enhancing axonal regeneration and neuroprotection. An understanding of spatio‐temporal transgene expression in the spinal cord is essential for future studies of SCI therapies. Commonly, intracellular marker proteins (e.g., EGFP) were used as indicators of transgene levels after viral delivery, which may not accurately reflect levels of secreted transgene. This study examined transgene expression using ELISA after viral delivery of D15A, a neurotrophin with BDNF and NT‐3 activities, at 1, 2, and 4weeks after in vivo and ex vivo delivery using lentiviral, adenoviral, and retroviral vectors. Further, the inflammatory responses and viral infection patterns after in vivo delivery were examined. Lentiviral vectors had the most stable pattern of gene expression, with D15A levels of 536 ± 38 and 363 ± 47 pg/mg protein seen at 4 weeks after the in vivo and ex vivo delivery, respectively. Our results show that protein levels downregulate disproportionately to levels of EGFP after adenoviral vectors both in vivo and ex vivo. D15A dropped from initial levels of 422 ± 87 to 153 ± 18 pg/mg protein at 4 weeks after in vivo administration. Similarly, ex vivo retrovirus‐mediated transgene expression exhibited rapid downregulation by 2 weeks post‐grafting. Compared to adenoviral infection, macrophage activation was attenuated after lentiviral infection. These results suggest that lentiviral vectors are most suitable in situations where stable long‐term transgene expression is needed. Retroviral ex vivo delivery is optional when transient expression within targeted spinal tissue is desired, with adenoviral vectors in between. © 2006 Wiley‐Liss, Inc.
Antioxidant content and ascorbate metabolism in cherry tomato exocarp in relation to temperature and solar radiation
Authors: Rosales Miguel A , Ruiz Juan M , Hernández Joaquín , Soriano Teresa , Castilla Nicolás , Romero Luis 
Published: June 2006

AbstractConsidering the economic importance of the tomato and its nutritional benefits to human health, a study was made of how two different environmental factors (temperature and overall solar radiation) influence the nutritional quality of cherry tomatoes during the plant full production cycle. Solanum lycopersicum L. cv. Naomi plants were grown in an experimental greenhouse. Three fruit samples were taken over the full production period: first sampling at the beginning of harvest (7 January 2004), second at mid‐harvest (22 March 2004) and third at harvest end (30 May 2004). Values for temperature and overall accumulated solar radiation peaked at a maximum in the third sampling, without lowering the yield with respect to previous samplings. Regarding the antioxidant activity in the exocarp fraction of the cherry tomato fruits, the results showed that the increase in temperature and solar radiation diminished the lycopene and β‐carotene contents in the third sampling, inducing defective pigmentation (sunscald). This occurred simultaneously with an increase in lipid peroxidation during the third sampling, quantified as lipoxygenase activity and malondialdehyde content. Finally, in relation to ascorbate metabolism, the higher temperatures and stronger solar radiation at the third sampling increased the oxidation of reduced ascorbate (AsA) due to intensified ascorbate peroxidase (APX) and ascorbate oxidase (AO) activities and a depression of the enzyme dehydroascorbate reductase (DHAR). In conclusion, the results indicate that despite the oxidation of AsA by APX and AO, the minimal regeneration of the latter, together with the greater lipid peroxidation with increasing temperature and solar radiation in the greenhouse, explained the lower content of antioxidants in the exocarp and therefore the loss of nutritional quality of the cherry tomato fruits grown under these conditions. Copyright © 2006 Society of Chemical Industry
Phase Development Mechanism during Drawing from Highly Entangled Polyethylene Melts
Authors: Uehara Hiroki , Kakiage Masaki , Yamanobe Takeshi , Komoto Tadashi , Murakami Syozo 
Published: June 2006

AbstractSummary: The phase development mechanism during drawing from a highly entangled melt of ultra‐high‐molecular‐weight polyethylene is analyzed by simultaneous measurements of in situ X‐ray diffraction using synchrotron radiation and stress/strain behavior. The stress/strain curve exhibits a plateau region at the initial stage of the draw, and no crystalline reflections appear on a series of in situ X‐ray diffraction patterns. However, as the sample draw proceeds above a critical strain, a metastable hexagonal reflection appears and becomes predominant, where the stress/strain curve still shows a plateau deformation. With a further increase of the strain, the intensity of the hexagonal reflection peak begins to decrease and subsequently that of the usual orthorhombic ones increase. Correspondingly, a rapid increase of draw stress, because of the strain‐hardening behavior, is recorded.Stacked line profiles extracted from in situ WAXD patterns along the equatorial direction. The red profile was obtained at the critical time of 162.5 s.magnified imageStacked line profiles extracted from in situ WAXD patterns along the equatorial direction. The red profile was obtained at the critical time of 162.5 s.
Explicit formulations of tangent stiffness tensors for isotropic materials
Authors: Dui Guansuo , Wang Zhengdao , Ren Qingwen 
Published: June 2006

AbstractA compact explicit expression for the tangent stiffness tensor is presented. Throughout the analysis, the formulation holds for general isotropic elastic materials and does not require solving eigenvector problems. On the theoretical side, a very simple solution of a tensor equation is obtained. Then the expressions for the derivatives of general symmetric isotropic tensor functions of a symmetric tensor are developed. On the computational side, particular attention is given to the consideration of the special case, Green elastic materials, in which the strain energy does not admit a closed‐form expression in terms of principal invariants. Finally, a simple formulation of the tangent stiffness tensor for Ogden material model is supplied. Copyright © 2006 John Wiley & Sons, Ltd.
Stage III cystic partially differentiated nephroblastoma recurring after nephrectomy and chemotherapy
Authors: Baker Jillian Margaret , Viero Sandra , Kim Peter C. , Grant Ronald M. 
Published: June 2006

AbstractCystic partially differentiated nephroblastoma (CPDN) has low malignant potential. We report a 1‐year‐old with stage III CPDN of the right kidney that recurred following radical nephrectomy and chemotherapy. There was evidence of tumor spillage pre‐operatively and intra‐operatively. During chemotherapy the disease recurred in the omentum and the peritoneum. Pathology of the recurrent resected cysts revealed a more differentiated biphasic tumor without blastemal elements. It appears that spillage of CPDN in our patient led to dissemination of disease. Chemotherapy failed to prevent recurrence but only mature elements were present following this treatment. The intensity of therapy required to treat CPDN remains undefined. Pediatr Blood Cancer 2008;50:129–131. © 2006 Wiley‐Liss, Inc.
Defibrotide for the treatment of hepatic veno‐occlusive disease in children
Authors: Bulley Sean R. , Strahm Brigitte , Doyle John , Dupuis L. Lee 
Published: June 2006

AbstractBackgroundThis retrospective report describes experience with defibrotide in children with hepatic veno‐occlusive disease (HVOD) following hematopoietic progenitor cell transplant (HPCT) in a single institution.ProcedureChildren who had undergone HPCT between February 1999 and June 2001 and between July 2003 and September 2004 and who received defibrotide during their admission were identified. Demographic data and information regarding the clinical course of these patients were abstracted from their health records.ResultsFourteen children (mean age: 9.3 years; range: 0.4–18.1) who underwent HPCT during the study period received defibrotide for the treatment of HVOD; nine were girls. Most patients underwent HPCT for hematologic malignancies (8/14) and received matched unrelated donor transplants (8/14). Conditioning regimens included cyclophosphamide with total body irradiation (5/14) and busulfan followed by cyclophosphamide (7/14). HVOD was diagnosed on transplant day −4 to +33 (median: +10.5); defibrotide was started on transplant day −4 to +40 (median: +12). The median initial defibrotide dose was 33 mg/kg/day (11–40 mg/kg/day); the median maximum defibrotide dose was 38.5 mg/kg/day (11–81 mg/kg/day). The median duration of defibrotide therapy was 16 days (4–37 days). Defibrotide was discontinued due to clinical improvement (9), death (3), drug unavailability (1), and neurological toxicity (1). Gastrointestinal hemorrhage was observed in two patients and intra‐cranial hemorrhage was observed in one patient during defibrotide therapy. The survival rate to day +100 was 79%.ConclusionsDefibrotide appears to be an effective and relatively safe treatment for children with HVOD. Pediatr Blood Cancer 2007;48:700–704. © 2006 Wiley‐Liss, Inc.
Single‐walled nanotube bucky paper and nanocomposite
Authors: Gou Jihua 
Published: June 2006

AbstractA new processing method for the fabrication of single‐walled nanotube (SWNT)‐reinforced nanocomposites was developed to achieve uniform dispersion and high composition of the nanotubes in the nanocomposites. In this method, SWNTs were preformed as bucky paper by multi‐step dispersion and micro‐filtration of a suspension of nanotubes. The nanocomposites were then fabricated by infiltration of diluted epoxy resin through the bucky paper and hot pressing. The wetting of the nanocomposites was examined using scanning electron microscopy and atomic force microscopy. The results showed that the epoxy resin completely penetrated the bucky paper through the nanoporous structures. The results of dynamic mechanical analysis of the nanocomposites showed that the storage moduli of the nanocomposites increased by 200–250%. The tan δ curves indicated that the nanotubes had a strong influence on the damping properties of the nanocomposites. This processing technique is an effective method for fabricating nanocomposites with uniform dispersion and high composition of SWNTs. Copyright © 2006 Society of Chemical Industry