bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of gamma radiation on β‐lactoglobulin: Oligomerization and aggregation
Authors: Oliveira Cristiano L. P. , Hoz Lucia de la , Silva Julio C. , Torriani Iris L. , Netto Flavia M. 
Published: October 2006

AbstractThe conformational changes and aggregation process of β‐lactoglobulin (β‐LG) subjected to gamma irradiation are presented. β‐LG in solutions of different protein concentrations (3 and 10 mg/ml) and in solid state with different water activities (aw) (0.22; 0.53; 0.74) was irradiated using a Cobalt‐60 radiation source at dose level of 1–50 kGy. Small‐angle X‐ray scattering (SAXS) was used to study the conformational changes of β‐LG due to the irradiation treatment. The irradiated protein was also examined by high performance size exclusion chromatography (HPSEC) and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) under nonreducing and reducing conditions and fluorescence. SAXS analysis showed that the structural conformation of irradiated β‐LG in solid state at different aw and dose level was essentially the same as the nonirradiated β‐LG. The scattering data also showed that the irradiation of β‐LG in solution promoted the formation of oligomers. Interestingly, from the data analysis and model building, it could be shown that the formed oligomers are linear molecules, built by linear combinations of β‐LG dimers (tetramers, hexamers, etc). The formation of oligomers was also evidenced by SDS–PAGE analysis and HPSEC chromatograms, in which products with higher molecular mass than that of the dimeric β‐LG were detected. Formation of intermolecular cross‐linking between tyrosyl radicals are proposed to be at least partially responsible for this occurrence. From the results it could be shown that the samples irradiated in solution presented some conformational changes under gamma irradiation, resulting in well ordered oligomers and aggregates formed by cross‐linking of β‐LG dimers subunits, while the samples irradiated in the solid state were not modified. © 2006 Wiley Periodicals, Inc. Biopolymers 85: 284–294, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
OO Bond Formation in the S4 State of the Oxygen‐Evolving Complex in Photosystem II
Authors: Siegbahn Per E. M. 
Published: October 2006

AbstractBased on recent X‐ray structures of the oxygen‐evolving complex in photosystem II, quantum chemical geometry optimizations of several thousand structures have been performed in order to elucidate the mechanism for dioxygen formation. Many of the results of these calculations have been presented previously. The energetically most stable structure of the S4 state has been used in the present study to investigate essentially all the possible ways the OO bond can be formed in this structure. A key feature, emphasized previously, of the S4 state is that an oxygen radical ligand is present rather than an MnV state. Previous studies have indicated that this oxygen radical can form an OO bond by an attack from a water molecule in the second coordination shell. The present systematic investigation has led to a new type of mechanism that is significantly favored over the previous one. A calculated transition‐state barrier of 12.5 kcal mol−1 was found for this mechanism, whereas the best previous results gave 18–20 kcal mol−1. A requirement on the spin alignment for a low barrier is formulated.
Ion‐Induced Biomolecular Radiation Damage: From Isolated Nucleobases to Nucleobase Clusters
Authors: Schlathölter Thomas , Alvarado Fresia , Bari Sadia , Lecointre Aurelie , Hoekstra Ronnie , Bernigaud Virgil , Manil Bruno , Rangama Jimmy , Huber Bernd 
Published: October 2006

AbstractA large number of studies are devoted to the investigation of the biomolecular ionization and fragmentation dynamics underlying biological radiation damage. Most of these studies have been based on gas‐phase collisions with isolated DNA building blocks. The radiobiological significance of these studies is often questioned because of the lack of a chemical environment. To clarify this aspect, we studied interactions of keV ions with isolated nucleobases and with nucleobase clusters by means of coincidence time‐of‐flight spectrometry. Significant changes already show up in the molecular fragmentation patterns of very small clusters.
Identification of the D3h Isomer of Carbon Trioxide (CO3) and Its Implications for Atmospheric Chemistry
Authors: Jamieson Corey S. , Mebel Alexander M. , Kaiser Ralf I. 
Published: October 2006

AbstractThe CO3 molecule is considered an important reaction intermediate in the atmospheres of Earth and Mars for quenching electronically excited oxygen atoms and in contributing to the anomalous 18O isotope enrichment. The geometry of the CO3 intermediate plays an important role in explaining these effects; however, only the cyclic (C2v) isomer has been experimentally confirmed so far. Here, we report on the first spectroscopic detection of the acyclic (D3h) isomer of carbon trioxide (12C16O3) via its ν1 and ν2 vibrational modes centered around 1165 cm−1 under matrix isolation conditions; the identification of the 12C18O3, 13C16O3, 13C18O3, 16O12C18O2, and 18O12C16O2 isotopomers of the acyclic isomer confirms the assignments.
Distributed radio access technology selection for adaptive networks in high‐speed, B3G infrastructures
Authors: Tsagkaris K. , Dimitrakopoulos G. , Saatsakis A. , Demestichas P. 
Published: October 2006

AbstractWireless systems migrate towards the era of ‘Beyond the 3rd Generation’ (B3G). A fundamental facilitator of this vision is the evolution of high speed, adaptive networks, needed for better handling the offered demand and improving resource utilization. Adaptive networks dynamically select their configuration, in order to optimally adapt to the changing environment requirements and conditions. This paper presents optimization functionality that can be used to support network adaptability (cognition‐reconfigurability) in a B3G context. The paper starts from the business case that justifies the need for placing research onto adaptive networks and then continues with the management functionality for (re)configuration decisions, which is targeted to the dynamic selection of the appropriate radio access technologies (RATs). RAT selection is modelled through an optimization problem called (RAT, Demand and QoS‐Assignment problem—RDQ‐A), the solution of which assigns in a distributed manner the available RATs to adaptive Base Station transceivers and the demand (users) to these transceivers and to QoS levels, respectively. The RDQ‐A optimization problem is decoupled in several sub‐problems and is implemented in phases corresponding to the aforementioned assignments, while efficient custom greedy algorithms are mobilized in each phase for obtaining the optimum assignment. Finally, indicative results from the application of the proposed functionality to a simulated network are presented. Copyright © 2006 John Wiley & Sons, Ltd.
Increased osteoblast adhesion on nanograined Ti modified with KRSR
Authors: Balasundaram Ganesan , Webster Thomas J. 
Published: October 2006

AbstractPeptide sequences such as lysine‐arginine‐serine‐arginine (KRSR) selectively bind transmembrane proteoglycans (e.g. heparin sulfate) of osteoblasts (bone‐forming cells) and are, therefore, actively being investigated for orthopedic applications. Further, nanophase materials (or materials with grain or particle sizes less than 100 nm) are promising new materials that promote new bone growth more than compared to conventional (that is, micron grain or particle size) materials. To combine the above two promising approaches for improving orthopedic implants, the objective of this in vitro study was to functionalize titanium (Ti) surfaces (both nanophase and conventional) with KRSR peptides and study their osteoblast cell adhesive properties. Materials were characterized by X‐ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy. Results of this in vitro study provided evidence of increased osteoblast adhesion on nanophase compared to conventional Ti whether functionalized with KRSR or not. Results further showed that the immobilization of KRSR onto Ti (both nanophase and conventional) increased osteoblast adhesion compared to respective nonfunctionalized Ti and those functionalized with the negative control peptide KSRR. Most importantly, osteoblast adhesion on nonfunctionalized nanophase Ti increased compared to conventional Ti functionalized with KRSR. Further, select initial osteoblast adhesion was observed to occur at particle boundaries for any type of nanophase and conventional Ti formulated in this study. In summary, results provided evidence that not only should nonfunctionalized nanophase Ti be further studied for improved orthopedic applications but so should nanophase Ti functionalized with KRSR. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Enhancement of in vitro osteogenesis on titanium by chemically produced nanotopography
Authors: de Oliveira Paulo Tambasco , Zalzal Sylvia Francis , Beloti Marcio Mateus , Rosa Adalberto Luiz , Nanci Antonio 
Published: October 2006

AbstractThe surface characteristics of biomaterials can influence protein adsorption, cellular functions, and ultimately tissue formation. Controlled chemical oxidation of titanium‐based surfaces with a mixture of H2SO4/H2O2 creates a nanopatterned surface that has been shown to affect early osteogenic events. The objective of this study was to evaluate the effect over time of this nanopattern on various key parameters of osteogenesis, and determine whether these effects ultimately translate into more mineralized matrix production. Osteogenic cells were obtained by enzymatic digestion of newborn rat calvaria and grown on treated and untreated titanium discs for periods of up to 14 days. Alkaline phosphatase activity peaked earlier and cell number was higher as of day 7 on the nanopatterned discs. Immunofluorescence showed that the treated surface favored early bone sialoprotein and osteopontin secretion, and fibronectin accumulation. Alizarin red staining revealed that, at days 10 and 14, there were significantly more mineralized nodules on treated than on untreated discs. These results demonstrate that simple chemical treatment of titanium with H2SO4/H2O2 accelerates the in vitro osteogenic potential of calvaria‐derived cells. They also suggest that this treatment may represent an advantageous approach for producing “intelligent surfaces” that stimulate bone formation and enhance bone‐implant contact. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
(−)‐epigallocatechin gallate enhances prostaglandin F2α‐induced VEGF synthesis via upregulating SAPK/JNK activation in osteoblasts
Authors: Tokuda Haruhiko , Takai Shinji , Matsushima‐Nishiwaki Rie , Akamatsu Shigeru , Hanai Yoshiteru , Hosoi Takayuki , Harada Atsushi , Ohta Toshiki , Kozawa Osamu 
Published: October 2006

AbstractCatechin, one of the major flavonoids presented in plants such as tea, reportedly suppresses bone resorption. We previously reported that prostaglandin F2α (PGF2α) stimulates the synthesis of vascular endothelial growth factor (VEGF) via p44/p42 mitogen‐activated protein (MAP) kinase in osteoblast‐like MC3T3‐E1 cells. To clarify the mechanism of catechin effect on osteoblasts, we investigated the effect of (−)‐epigallocatechin gallate (EGCG), one of the major green tea flavonoids, on the VEGF synthesis by PGF2α in MC3T3‐E1 cells. The PGF2α‐induced VEGF synthesis was significantly enhanced by EGCG. The amplifying effect of EGCG was dose dependent between 10 and 100 µM. EGCG did not affect the PGF2α‐induced phosphorylation of p44/p42 MAP kinase. SB203580, a specific inhibitor of p38 MAP kinase, and SP600125, a specific inhibitor of stress‐activated protein kinase/c‐Jun N‐terminal kinase (SAPK/JNK), reduced the PGF2α‐induced VEGF synthesis. EGCG markedly enhanced the phosphorylation of SAPK/JNK induced by PGF2α without affecting the PGF2α‐induced phosphorylation of p38 MAP kinase. SP600125 markedly reduced the amplification by EGCG of the SAPK/JNK phosphorylation. In addition, the PGF2α‐induced phosphorylation of c‐Jun was amplified by EGCG. These results strongly suggest that EGCG upregulate PGF2α‐stimulated VEGF synthesis resulting from amplifying activation of SAPK/JNK in osteoblasts. J. Cell. Biochem. 100: 1146–1153, 2007. © 2006 Wiley‐Liss, Inc.
Template atom transfer radical polymerization of a diaminopyrimidine‐derivatized monomer in the presence of a uracil‐containing polymer
Authors: Tang Huadong , Radosz Maciej , Shen Youqing 
Published: October 2006

AbstractUracil‐derivatized monomer 6‐undecyl‐1‐(4‐vinylbenzyl)uracil and diaminopyrimidine‐derivatized monomer 2,6‐dioctanoylamido‐4‐methacryloyloxypyrimidine (DMP) were synthesized and polymerized by atom transfer radical polymerization (ATRP). A well‐defined, highly soluble, uracil‐containing polymer, poly[6‐undecyl‐1‐(4‐vinylbenzyl)uracil] (PUVU), was prepared in dioxane at 90 °C with CuBr/1,1,4,7,10,10‐hexamethyltriethylenetetramine as the catalyst and methyl α‐bromophenylacetate as the initiator. PUVU was further used as a template for the ATRP of DMP. The enhanced apparent rate constant of the DMP polymerization in the presence of PUVU indicated that the ATRP of DMP occurred along the PUVU template. The template polymerization produced a stable and insoluble macromolecular complex, PUVU/poly(2,6‐dioctanoylamido‐4‐methacryloyloxypyrimidine). An X‐ray diffraction study confirmed that the complex had strandlike domains. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6607–6615, 2006
Second‐trimester intra‐abdominal bowel dilation in fetuses with gastroschisis predicts neonatal bowel atresia
Authors: Nick A. M. , Bruner J. P. , Moses R. , Yang E. Y. , Scott T. A. 
Published: October 2006

AbstractObjectiveTo determine in fetuses with gastroschisis the association between intra‐abdominal bowel dilation in the second trimester and neonatal bowel atresia.MethodsWe reviewed ultrasound and medical records of fetuses with gastroschisis from January 1998 to August 2004. Fetuses with intra‐abdominal bowel dilation in the second trimester were identified and followed into the neonatal period.ResultsWe identified 58 mother‐infant pairs showing fetal gastroschisis, with at least one prenatal ultrasound at our hospital and which were delivered there, or were transported there as newborns. Forty‐eight of the 58 fetuses had no intra‐abdominal bowel dilation and none of these neonates had bowel atresia. Ten of the 58 fetuses had intra‐abdominal bowel dilation and all had bowel atresia at birth (P < 0.0001). In eight cases in which ultrasound was performed at < 25 weeks' gestation, intra‐abdominal bowel dilation was already present.ConclusionIntra‐abdominal bowel dilation in the second trimester predicts neonatal bowel atresia in fetuses with gastroschisis. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Safety, Efficacy and Pharmacokinetics of Peginterferon α2a (40 kd) in Children With Chronic Hepatitis C
Authors: Schwarz Kathleen B. , Mohan Parvathi , Narkewicz Michael R. , Molleston Jean Pappas , Nash S. Russell , Hu Sylvia , Wang Ka , Gries Jean Michel 
Published: October 2006

ABSTRACTChronic hepatitis C virus (HCV) infection in children is a problem affecting thousands of children worldwide. Although standard interferon (INF) has better efficacy in pediatric patients than in adults, results in children with genotype 1 are poor; response rates to combination treatment with standard INF and ribavirin are better but the treatment requires thrice‐weekly injections. The improved antiviral efficacy of weekly pegylated interferons relative to standard interferons in adults with chronic HCV infection suggests that pegylated interferons may also improve antiviral efficacy in children. We therefore investigated the pharmacokinetics, efficacy and safety of peginterferon α2a (pegINF‐α2a) (40 kd) in 14 children ages 2 to 8 years with chronic hepatitis C (13 genotype 1, 1 non‐1 genotype). Drug dose was calculated from each patient's body surface area (BSA) according to the formula BSA (m2)/(1.73 m2) × 180 μg, and patients were administered once‐weekly subcutaneous injections for 48 weeks. Viral load and pharmacokinetic parameters were determined from blood drawn throughout the study and during follow‐up. At week 24, the mean trough concentration was about 20% below values obtained from adults treated with pegINF‐α2a, and the area under the curve from 0 to 168 hours was about 20% above adult values, suggesting that drug doses calculated from BSA achieved therapeutically adequate concentrations. Six of 14 patients (43%), all infected with genotype 1, achieved a sustained virological response. Adverse events were those commonly associated with INF‐based treatment, and none was deemed serious. In conclusion, our findings provide a basis for larger studies evaluating the efficacy and safety of pegINF‐α2a as monotherapy as well as in combination with ribavirin in pediatric patients with chronic hepatitis C.
Effect of a Low‐Cost Food on the Recovery and Death Rate of Malnourished Children
Authors: Greco Luigi , Balungi Jacquie , Amono Kevin , Iriso Robert , Corrado Bruno 
Published: October 2006

ABSTRACTObjectives:Nutritional rehabilitation in Africa relies mainly on imported skim milk enriched with a sugar and salt mixture. We evaluated whether milk plus porridge made from local ingredients improves the outcome of childhood nutritional rehabilitation versus milk alone.Patients and Methods:This study was conducted in a nutritional unit in Lacor (Northern Uganda). The porridge, made from cheap locally available ingredients (maize flour, dried fish or meat, peanut butter and oil) supplemented with proteins and fats, provides 1.1 energy units, 4.4 kJ/g. We randomly sampled the files of 100 cases discharged in October, November and December 2001 (preintervention), in 2002 (soon after intervention onset) and in 2003 (more than 1 year after intervention onset). We recorded the average hospital days and average oedema‐free weight gain at discharge in the 3 groups.Results:Average oedema‐free weight gain increased from 21 g/d (95% confidence interval [CI], 12‐29) in 2001 to 35 g/d (95% CI, 25‐45) in 2002 and reached 59 g/d (95% CI, 51‐65) in 2003. Mortality decreased from 22% to 7.8%, and nutritional failures (insufficient weight gain) decreased by greater than 50%.Conclusions:The low‐cost porridge supplement (€2640/yr per 100 children) was effective in treating malnutrition. Widespread use of the porridge, which resulted in better outcomes than milk alone, could produce a savings in the medium‐ to long‐term, thereby releasing resources for other uses. A high‐energy porridge that is made from locally available ingredients and does not require imported foods seems to be appropriate for supplementary feeding after mother's milk in this setting.
Does the clinical efficacy of vardenafil correlate with its effect on the endothelial function of cavernosal arteries? A pilot study
Authors: Mazo Evsey B. , Gamidov Safar I. , Iremashvili Vyacheslav V. 
Published: October 2006

OBJECTIVETo investigate whether the results of the ultrasonographic (US) measurement of post‐occlusive changes in the diameters of cavernosal arteries after administering phosphodiesterase type 5 (PDE‐5) inhibitor vardenafil could be associated with the response to vardenafil in patients with erectile dysfunction (ED), as currently there are no reliable methods for predicting the success rate of oral PDE‐5 inhibitors.PATIENTS AND METHODSThe study included 122 men with ED; after a complex evaluation, the endothelial function of the cavernosal arteries was assessed in all patients before and 1 h after oral ingestion of vardenafil (20 mg), using our modification of the US assessment of post‐occlusive changes in the diameter of cavernosal arteries. After the evaluation, all patients received vardenafil 20 mg on demand for 4 weeks. A successful response was defined using two endpoints, i.e. the normalization of the International Index of Erectile Function Erectile Function domain score (≥26) and positive answers to both Sexual Encounter Profile questions 2 and 3 on ≥ 75% of occasions, based on the diary data collected.RESULTSIn all patients the mean (sd) initial percentage increase in the cavernosal artery diameter (PICAD) in responders and nonresponders was not statistically different, at 49 (24) and 43 (26), respectively (P = 0.168), but PICAD values after vardenafil were significantly greater in responders, at 73 (16) vs 55 (23) (P < 0.001). Analysis of data from patients with different causes of ED showed statistically significant differences in PICAD between responders and nonresponders only in those with arteriogenic ED. The sensitivity and specificity of a PICAD of ≥ 50% after taking vardenafil 20 mg for predicting a positive response to the same dose of the drug in patients with arteriogenic ED were 94.9% and 91.3%, respectively.CONCLUSIONThe results of the US assessment of post‐occlusive changes in the diameter of cavernosal arteries after vardenafil administration are significantly associated with the clinical efficacy of the drug in patients with arteriogenic ED.
Prostate‐specific antigen testing: uncovering primary care influences
Authors: Gormley Gerard J. , Catney Denise , McCall Jacqueline R. , Reilly Philip M. , Gavin Anna T. 
Published: October 2006

OBJECTIVESTo examine influences on the behaviour of General Practitioner (GP) in relation to prostate‐specific antigen (PSA) testing.SUBJECTS AND METHODSIn Northern Ireland in 2003–2004, all GPs (1067) were invited to complete a self‐administered postal questionnaire survey that was then matched with a regional PSA‐testing database. The main outcome measures were individual GP responses for demographic, practice and training characteristics, PSA testing behaviour and perceived influences, matched against GP‐initiated first PSA tests performed in 2003 and 2004 (22 207 tests).RESULTSIn all, 704 GPs (66%) responded and 49% of these reported awareness of the national guidelines, which was highest among those attending postgraduate meetings. PSA tests were more likely to be ordered by full‐time male GPs who had attended a local postgraduate urology meeting; ran a ‘well‐man’ clinic; tested men with unrelated complaints; and were not in a training practice. Testing levels were highest among GPs who had been practising for 21–30 years and those in rural practices. Awareness of national guidelines or having had a postgraduate post in urology did not affect testing behaviour. After adjusting for gender, working hours, duration in practice and urban/rural setting, independent influences increasing testing behaviour were: testing men with a positive family history or unrelated complaints; testing any man who requests it; and previous experience of prostate cancer being detected in an asymptomatic patient by PSA testing. Working in an accredited training practice was associated with lower testing levels.CONCLUSIONThere are complex influences on the PSA testing behaviour of GPs; addressing these influences could contribute to the rationalization of testing. A low awareness of national guidelines indicates a need for new strategies to disseminate and implement guidelines. The influence of local educational meetings on PSA testing is an unharnessed force.