bluuebunny/crossref_metadata_2025_split huggingface dataset:
CE characterization of semiconductor nanocrystals encapsulated with amorphous silicium dioxide
Authors: Pyell Ute 
Published: January 2008

AbstractThe electrophoretic mobility of silica‐encapsulated semiconductor nanocrystals (quantum dots) dependent on the pH and the ionic strength of the separation electrolyte has been determined by CE. Having shown the viability of the approach, the electrophoretic mobility μ of the nanoparticles investigated is calculated for varied zeta potential ζ, particle radius r, and ionic strength I employing an approximate analytical expression presented by Ohshima (J. Colloid Interface Sci. 2001, 239, 587–590). The comparison of calculated with measured data shows that the experimental observations exactly follow what would be expected from theory. Within the parameter range investigated at fixed ζ and I there is an increase in μ with r which is a nonlinear function. This dependence of μ on size parameters can be used for the size‐dependent separation of particles. Modeling of μ as function of I and ζ makes it possible to calculate the size distribution of nanoparticles from electrophoretic data (using the peak shape of the particle zone in the electropherogram) without the need for calibration provided that ζ is known with adequate accuracy. Comparison of size distributions calculated via the presented method with size histograms determined from transmission electron microscopy (TEM) micrographs reveals that there is an excellent matching of the size distribution curves obtained with the two independent methods. A comparison of calculated with measured distributions of the electrophoretic mobility showed that the observed broad bands in CE studies of colloidal nanoparticles are mainly due to electrophoretic heterogeneity resulting from the particle size distribution.
Maximizing association statistics over genetic models
Authors: González Juan R. , Carrasco Josep L. , Dudbridge Frank , Armengol Lluís , Estivill Xavier , Moreno Victor 
Published: January 2008

AbstractThe assessment of the association between a candidate locus and a disease may require the assumption of an inheritance model. Most researchers select the additive model and test the association with the Cochran‐Armitage trend test. This test assumes a dose‐response effect with regard to the number of copies of the variant allele. However, if there is reason to expect dominance or recessiveness in the effect of the variant allele, the heterozygous genotype may be grouped with one of the two homozygous, depending on the inheritance model, and a simple test on the 2 × 2 table can be used to assess independence. When the underlying genetic model is unknown, association may be assessed using the max‐statistic, which selects the largest test statistic from the dominant, recessive and additive models. The statistical significance of the max‐statistic has been previously addressed using permutation or Monte Carlo simulation approaches. We aimed to provide simpler alternatives to the max‐test to make it feasible in large‐scale association studies. Our simulations show that this procedure has an effective number of tests of 2.2, which can be used to correct the significance level or P‐values. We also derive the asymptotic distribution of max‐statistic, which leads to a simple way to calculate the significance level and allows the derivation of a formula for power calculations in the design of studies that plan to use the max‐statistic. A simulation study shows that the use of the max‐statistic is a powerful approach that provides safeguard against model uncertainty. Genet. Epidemiol. 2008 Wiley‐Liss, Inc.
On the analysis of copy‐number variations in genome‐wide association studies: a translation of the family‐based association test
Authors: Ionita‐Laza Iuliana , Perry George H. , Raby Benjamin A. , Klanderman Barbara , Lee Charles , Laird Nan M. , Weiss Scott T. , Lange Christoph 
Published: January 2008

AbstractThough there is an increasing support for an important contribution of copy number variation (CNV) to the genetic architecture of complex disease, few methods have been developed for the analysis of such variation in the context of genetic association studies. In this paper, we propose a generalization of family‐based association tests (FBATs) to allow for the analysis of CNVs at a genome‐wide level. We translate the popular FBAT approach so that, instead of genotypes, raw intensity values that reflect copy number are used directly in the test statistic, thereby bypassing the need for a CNV genotyping algorithm. Moreover, both inherited and de novo CNVs can be analyzed without any prior knowledge about the type of CNV, making it easily applicable to large‐scale association studies. All robustness properties of the genotype FBAT approach are maintained and all previously developed FBAT extensions, including FBATs for time‐to‐onset, multivariate FBATs, and FBAT‐testing strategies, can be directly transferred to the analysis of CNVs. Using simulation studies, we evaluate the power and the robustness of the new approach. Furthermore, for those CNVs that can be genotyped, we compare FBATs based on genotype calls with FBATs that are directly based on the intensity data. An application to one of the first CNV genome‐wide‐association studies of asthma identifies a very plausible candidate gene. A software implementation of the approach is freely available at http://www.hsph.harvard.edu/research/iuliana‐ionita/software. The approach has also been completely integrated in the PBAT software package. Genet. Epidemiol. © 2008 Wiley‐Liss, Inc.
Clavicular osteomyelitis: A rare complication of head and neck cancer surgery
Authors: Burns Paul , Sheahan Patrick , Doody Jaime , Kinsella John 
Published: January 2008

AbstractBackgroundWe report the 10th case in the English‐language literature describing clavicular osteomyelitis that presented after radical treatment for laryngeal carcinoma and discuss the pertinent diagnostic and therapeutic measures. It presented a diagnostic dilemma. The differential diagnosis included tumor recurrence, metastatic bone disease, and postradiotherapy complications.Methods and ResultsA 45‐year‐old man who was a heavy smoker and known drug abuser presented with acute airway compromise and was diagnosed with squamous cell carcinoma involving the glottis and subglottis. Total laryngectomy, total thyroidectomy, and bilateral neck dissection were performed, and the patient underwent chemoradiotherapy. On follow‐up 1 year later, the patient was seen with left stomal dehiscence and a large area of cellulitis extending across the left clavicle and down to the axilla. At surgery, a large anterior chest wall abscess was found. Biopsy showed no evidence of tumor. After aggressive treatment, the patient remains disease free.ConclusionsThis condition is rarely encountered after major head and neck surgery. Aggressive surgical debridement and antibiotic therapy remains the mainstay of treatment. Prompt diagnosis and treatment are mandatory due to the potential life‐threatening complications associated with the condition. Bony resection will aid in adequate flap placement. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
Microvascular head and neck reconstruction in patients with liver cirrhosis
Authors: Cheng Nai‐Chen , Ko Jenq‐Yuh , Tai Hao‐Chi , Horng Shyue‐Yih , Tang Yueh‐Bih 
Published: January 2008

AbstractBackgroundThe aim of this retrospective case series was to review the safety, complications, and outcomes of free‐tissue transfer in head and neck cancer reconstruction in patients with liver cirrhosis.MethodsA retrospective review of all microvascular head and neck reconstruction cases with concomitant liver cirrhosis treated in our institution from 1994 to 2005 was performed. Data collected included patient demographics, etiology, and severity of liver cirrhosis, defect site, choice of free flap, complications, and clinical follow‐up.ResultsSeven patients were identified. They were all males and underwent microvascular head and neck reconstruction due to ablative cancer surgery. Their Child‐Pugh classification of liver cirrhosis was graded as follows: Child A (n = 3); Child B (n = 3); and Child C (n = 1). Eight free flaps were transferred (1 patient received 2), including anterolateral thigh (n = 4); radial forearm (n = 3); and fibula (n = 1). All flaps survived without the need for any microvascular revision procedures. Two patients died within postoperative 30 days due to hepatic decompensation. Other complications included neck hematoma (n = 1), neck wound infection (n = 2), and donor site dehiscence (n = 1). Only 2 patients with Child A cirrhosis remained free from complications and survived more than 1 year after the surgery.ConclusionMicrovascular head and neck reconstruction may be performed in patients with liver cirrhosis with a certain degree of technical success. However, the procedure is associated with significant mortality and morbidity in Child class B and C patients. Therefore, we recommend avoiding free‐tissue transfer in patients with head and neck cancer with advanced liver cirrhosis. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
ALK‐positive diffuse large B‐cell lymphoma: report of three cases
Authors: Lee Hyoun Wook , Kim Kihyun , Kim Wonseog , Ko Young Hyeh 
Published: January 2008

AbstractDiffuse large B‐cell lymphoma positive for anaplastic lymphoma kinase (ALK+ DLBCL) is a rare variant of diffuse large B‐cell lymphoma, with characteristic morphological, immunohistochemical and cytogenetic features. Only 34 cases of ALK‐positive diffuse large B‐cell lymphoma have so far been reported in the literature. We examined three new cases, which showed similar characteristics to previously reported cases, but with peculiar nuclear‐membrane staining for ALK protein in one patient and a 5′‐ALK gene deletion in another. All of them had stage IV disease at initial presentation, with poor outcomes. The tumour cells showed immunoblastic/plasmablastic histology and were positive for ALK and Oct2, but negative for CD3, CD20, CD79a, CD30 and PAX5. The staining pattern of ALK protein was cytoplasmic in two patients and associated with the nuclear membrane in one patient. Fluorescence in situ hybridization (FISH) analysis using the ALK break‐apart probe revealed ALK gene rearrangements in all three patients, with a 5′‐ALK gene deletion in one patient. These three cases suggest that different types of cytogenetic aberrations may involve the ALK gene in ALK‐positive diffuse large B‐cell lymphoma leading to peculiar immunohistochemical staining patterns. Copyright © 2008 John Wiley & Sons, Ltd.
An alternative approach to sustainable water users' organization in national irrigation systems: the case of the Khlong Thadi Weir System, southern Thailand
Authors: Ounvichit Tassanee , Ishii Atsushi , Kono Satoshi , Thampratankul Kanjana , Satoh Masayoshi 
Published: January 2008

AbstractThai national irrigation systems, serving a large number of small paddy farmers, require water users' organization for effective and sustainable joint management; however, water users' organizations (WUOs) presently cover only 27% of the total irrigation area. This three‐year action research investigated the difficulties in organizing water users in the Khlong Thadi Weir System in southern Thailand by immersion into the socio‐economic conditions of Muslim farmers in farm turnout No. 4 of the 1L‐4R‐LMC canal and the conventional on‐farm irrigation development there. We found the following: (1) subsistence farming and unstable tenancy discourage farmers from increasing their formal participation in irrigation management; (2) kinship is important but effective only in a limited space; (3) the conventional method of providing short ditches in a limited project timeframe creates a structural bias; (4) intrinsic internal water conflicts make the hydraulic relationship alone an inadequate basis for water users' organization; (5) alternatively, the social relationship between individual farmers and their community emerges as a promising scaffold for water users' organization; (6) the state irrigation agency should consider adopting a more vital role by supporting WUOs, tambon administration organizations and villages with needed incentives, technical information, and capacity building so that the WUOs are ultimately the decision makers. Copyright © 2008 John Wiley & Sons, Ltd.
Modelling soil moisture and assessing its impacts on water sharing and crop yield for the Wadi Laba spate irrigation system, Eritrea
Authors: Mehari Abraham , Schultz Bart , Depeweg Herman , Laat Pieter de 
Published: January 2008

AbstractIn the Wadi Laba spate irrigation system, sorghum and maize crops complete their growth period (September to April) mainly based on the soil moisture stored during the flood season from 15 June to 15 August. For the past 100 years, the farmers have strived to divert the unpredictable and destructive floods and irrigate their fields three to four times (irrigation gift is 50 cm each time) so as to harvest 4.5 t ha−1 yr−1 of sorghum or sorghum and maize. Simultaneously, to realize fair water sharing, the farmers introduced two water rights and rules: (1) a field is entitled to a second, third or fourth turn only after all other fields have received one, two or three turns respectively; (2) upstream fields have a priority right to the medium floods (≤50 m3 s−1), the midstream and downstream fields to the moderately large and large (50–200 m3 s−1), and very large (200–265 m3 s−1) floods respectively. These water rights and rules were regularly observed in the indigenous systems when farmers relied on each other for the timely maintenance of the earthen/brushwood structures that frequently failed, but are being violated following the introduction of the concrete structures in 2000.The Soil Water Accounting Model (SWAM) that has been developed as part of the study on which this paper is based revealed that when a field receives two, three or four turns, the soil moisture at the onset of the planting season remains the same, namely 67.5, 72 and 77.5 cm if the field gets its last turn by 15 July, 30 July and 15 August respectively. These results were validated with the more complex Soil Water Atmosphere Plant Model (SWAP). Even the 67.5 cm water depth (with some 120 mm contribution from rainfall), sufficiently supports the said yield. Unlike in the indigenous system, when the fields usually received a third turn by the end of the flood season, the concrete structures of the modern system have made it possible for the upstream farmers to irrigate three or even four times by July. Thus, to maintain fairness of water sharing, the water rights on the size of floods would have to be modified to: regardless of the flood size, if upstream fields are irrigated twice or three times by 15–30 July, the subsequent floods would have to be conveyed to the midstream/downstream fields. Copyright © 2008 John Wiley & Sons, Ltd.
Endothelial cells anchoring by functionalized yeast polypeptide
Authors: Xu Jie , Zhou Xiaolin , Ge Haiyan , Xu Hongwei , He Jian , Hao Zhenhong , Jiang Xun 
Published: January 2008

AbstractThe immobilization and proliferation of endothelial cells on the surface of engineered tissues requires the development of new biomaterials that can mimic the anchoring and signaling functions of basement membrane. Here, we report a modified polypeptide from yeast translation termination factor protein that can self‐assembly into nanofibers and improve endothelial cell adhesion by its functional motif. The polypeptide (YNNNLQGYQAGFQ) is a beta sheet forming sequence, but it is noninfectious in mammalian tissue because of the absence of substrate protein for propagation. The prion‐derived polypeptide was extended at the amino terminal with a short sequence motif from laminin I (YIGSR), and the resultant polypeptide retained self‐assembly propensity. Both circular dichroism (CD) measurement and molecular dynamics simulation suggest the assembled nanofibers consists mainly beta sheet structure. The 3D porous hydrogel formed by the modified polypeptide was evaluated as a coating material for vascular tissue engineering. In static culture system, the polypeptide scaffold improved the morphology of endothelial cells and confluency of cell monolayer. In the dynamic bioreactor (pulsatile vascular deformation at 5%), the polypeptide scaffold anchored 3‐fold higher number of endothelial cells, which exhibited normal nitric oxide release function. These results suggest that prion‐derived polypeptides have high self‐assembling and motif integrating capacities. These unique properties can be utilized to build up biomaterials with robust porous structure as well as functionalized motifs for cell enrichment. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Semiquantitative evaluation of fibronectin adsorption on unmodified and sulfonated polystyrene, as related to cell adhesion
Authors: Kowalczyńska Hanna M. , Nowak‐Wyrzykowska Małgorzata , Kołos Robert , Dobkowski Jacek , Kamiński Jarosław 
Published: January 2008

AbstractThe process of human fibronectin (FN) adsorption on nonsulfonated and sulfonated polystyrene surfaces was studied in relation to mechanisms of L1210 cell adhesion. Radioisotope assays directed towards FN, as well as ELISA measurements of adsorbed FN and bovine serum albumin (BSA) were carried out. 125I radioisotope assays led to linear FN adsorption isotherms. When combined to ELISA measurements for FN, they revealed the multilayer adsorption. Results indicated a large difference in the saturating first‐layer surface density of FN adsorbed on sulfonated and nonsulfonated polystyrene surfaces: significantly (ca. factor of 5) less FN molecules are necessary to complete a monolayer on sulfonated than on nonsulfonated polystyrene. This suggests an unfolded conformation of FN on sulfonated polystyrene, and a more compact one on the nonsulfonated polymer. Significant conformational changes of FN are also indicated by the following: (1) early phase of cell adhesion to FN adsorbed on sulfonated polystyrene surfaces is significantly (ca. factor of 6) higher than to FN on nonsulfonated surfaces, and in the former case adhesion proceeds mostly via α5β1 integrins; (2) RGD, the crucial fragment within central cell binding domain, seems to be partially hidden in the protein structure adopted on nonsulfonated surfaces; (3) patterns of F‐actin organization differ in cells adhering to FN on sulfonated and nonsulfonated surfaces. The ELISA study directed against BSA (this protein always present on the surface after the adsorption of FN), showed the importance of “free area,” uncovered by both proteins, which influence the cell adhesion processes. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
A phase I clinical trial of interferon‐beta gene therapy for high‐grade glioma: novel findings from gene expression profiling and autopsy
Authors: Wakabayashi Toshihiko , Natsume Atsushi , Hashizume Yoshio , Fujii Masazumi , Mizuno Masaaki , Yoshida Jun 
Published: January 2008

AbstractBackgroundHigh‐grade gliomas are highly lethal neoplasms representing approximately 20% of all intracranial tumors. Cationic liposome‐mediated interferon‐beta (IFN‐β) gene transfer has been found to induce regression of experimental glioma. We have previously performed a pilot clinical trial to evaluate the safety and effectiveness of this IFN‐β gene therapy in five patients with high‐grade glioma. Two patients showed more than 50% reduction while others had stable disease 10 weeks after treatment initiation.MethodsTo identify alterations in gene expression in brain tumors 2 weeks after the gene therapy trial, we used a microarray technology and Gene Ontology analysis. The results were validated by patients' clinical course and findings of histology and autopsy.Results and conclusionsUsing hierarchical clustering and principal component analysis, five series of gene therapy trials were classified according to the response to IFN‐β gene therapy. Significant changes in gene expression related to immunoresponse and apoptosis were observed. Moreover, novel patterns of altered gene expression, such as inhibition of neovascularization, were identified, suggesting the involvement of pathways reported previously as not involved. Autopsy and histological examinations revealed dramatic changes in the tumor tissues after therapy in all patients. Many tumor cells showed necrotic changes, and immunohistochemistry identified numerous CD8‐positive lymphocytes and macrophages infiltrating the tumor and surrounding tissues; these were probably the effects of therapy. Simultaneously, CD34‐immunoreactive vessels were notably decreased in the vector‐injected brain. This study facilitates the understanding of the antitumor mechanism and helps identify candidate target molecules for new approaches. However, additional clinical trials are warranted. Copyright © 2008 John Wiley & Sons, Ltd.
Coating of adeno‐associated virus with reactive polymers can ablate virus tropism, enable retargeting and provide resistance to neutralising antisera
Authors: Carlisle Robert C. , Benjamin Reuben , Briggs Simon S. , Sumner‐Jones Stephanie , McIntosh Jenny , Gill Deborah , Hyde Steve , Nathwani Amit , Subr Vladimir , Ulbrich Karel , Seymour Leonard W. , Fisher Kerry D. 
Published: January 2008

AbstractBackgroundCopolymers based on poly‐[N‐(2‐hydroxypropyl) methacrylamide] (HPMA) have been used previously to enable targeted delivery of adenovirus. Here we demonstrate polymer‐coating techniques can also be used to modify and retarget adeno‐associated virus (AAV) types 5 and 8.MethodsThree strategies for modifying transductional targeting of AAV were employed. The first involved direct reaction of AAV5 or AAV8 with amino‐reactive HPMA copolymer. The second approach used carbodiimide (EDC) chemistry to increase the number of surface amino groups on the AAV5 capsid, thereby improving coating efficiency. In the third approach, the AAV5 genome was isolated from capsid proteins and delivered in a synthetic polyplex consisting of polyethylenimine (PEI) and HPMA.ResultsEfficient covalent attachment of HPMA copolymer to AAV5 could only be achieved following modification of the virus with EDC. Coating inhibited sialic acid dependent infection and provided a platform for retargeting via new ligands, including basic fibroblast growth factor. Retargeted infection was shown to be partially resistant to neutralising antisera. Delivery of AAV5 genomes using PEI and HPMA was efficient and provided absolute control of tropism and protection from antisera. In contrast AAV8 could be reacted directly with HPMA copolymer and allowed specific retargeting via the epidermal growth factor receptor, but gave no protection against neutralising antisera.ConclusionsReactive HPMA polymers can be used to ablate the natural tropism of both AAV8 and EDC‐modified AAV5 and enable receptor‐specific infection by incorporation of targeting ligands. These data show transductional targeting strategies can be used to improve the versatility of AAV vectors. Copyright © 2008 John Wiley & Sons, Ltd.