bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stiffening of Polycarbonate by Addition of a Highly Dispersed and Fibrillated Amorphous Polyamide‐Based Nanocomposite
Authors: Goitisolo Izaro , Eguiazábal José Ignacio , Nazabal Jon 
Published: January 2010

AbstractTernary systems consisting of blends of polycarbonate (PC) from bisphenol A and minority amounts of an amorphous polyamide reinforced with organically modified nanoclay (naPA), were obtained in the melt state. The nanoclay was widely exfoliated inside the dispersed naPA phase. The dispersed phase exhibited a very fine size (up to 0.36 µm), indicating compatibilization. Compatibilization was attributed to interactions between the aPA and the PC. The nanocomposite showed a lower compatibility than their corresponding blends. This lower compatibility of the nanocomposite was attributed to a hindrance of the interaction by the migrated surfactant of the organoclay. The presence of fibrillation in conjunction with a dispersed nanoclay resulted in additive enhancing effects on the modulus and yield stress. This led to modulus increases up to 46% with respect to that of the neat matrix upon the addition of 25% naPA‐10. Besides exhibiting these remarkable modulus values, these systems show an elongation at break similar to that of the neat PC matrix.magnified image
Combination therapy with sulfonylureas and metformin and the prevention of death in type 2 diabetes: a nested case‐control study
Authors: Azoulay Laurent , Schneider‐Lindner Verena , Dell'Aniello Sophie , Schiffrin Alicia , Suissa Samy 
Published: January 2010

AbstractPurposeTo determine whether combination of sulfonylureas and metformin increases the risk of death from any cause in patients with type 2 diabetes.MethodsA nested case‐control study was conducted within a population‐based cohort from the UK General Practice Research Database (GPRD). The cohort included patients over the age of 40 who were prescribed a first oral hypoglycaemic agent between 1 January 1988 and 30 June 2008. Cases included all patients who deceased during follow‐up. Up to 10 controls were matched to each case on year of birth, date of cohort entry (±1 year) and duration of follow‐up. Conditional logistic regression was used to estimate rate ratios (RRs) of death from any cause associated with the use of combination of sulfonylureas and metformin, relative to sulfonylurea monotherapy.ResultsThe cohort comprised 84 231 users of oral hypoglycaemic agents, of whom 14 996 died from any cause during a mean of 4.3 years of follow‐up (mortality rate 4.1 per 100 per year). Patients currently exposed to a combination of sulfonylureas and metformin were at a decreased risk of death from any cause compared to patients exposed to sulfonylurea monotherapy (adjusted RR: 0.77, 95%CI: 0.70, 0.85). Similar results were obtained for patients currently exposed to metformin monotherapy (adjusted RR: 0.70, 95%CI: 0.64, 0.75) when compared to sulfonylurea monotherapy. Patients had to be exposed to the combination therapy for at least 4 months prior to index date to experience a lower risk of mortality compared to sulfonylurea monotherapy.ConclusionsThe combination of sulfonylureas and metformin does not increase the risk of death. In contrast, it may moderately reduce this risk compared to sulfonylurea monotherapy. Copyright © 2010 John Wiley & Sons, Ltd.
Six minute walk distance or stair negotiation? Choice of activity assessment following total knee replacement
Authors: Crosbie Jack , Naylor Justine M. , Harmer Alison R. 
Published: January 2010

AbstractBackground and Purpose. Physiotherapists evaluating changing functional performance in patients who have undergone total knee replacement (TKR) will often measure a number of gait‐related activities, including six‐minute walk distance (6MWD) and the capacity to ascend and descend stairs. In this report, we investigated the correlations between the 6MWD and stair ascent and descent power in a group of patients who had participated in a clinical trial at 2, 8 and 26 weeks post‐TKR to establish whether there is redundancy in conducting all three tests. Methods. Retrospective analysis of data from a clinical trial was used. One hundred patients (57 female, 43 male) were tested on their 6MWD and power generated and absorbed during stair ascent and descent, respectively. Linear regression modelling was used to determine correlations between pairs of variables at the three measurement intervals. Results. There were consistent relationships between each pair of variables at each measurement interval (r > 0.70; p < 0.001) and also a consistency in the regressions between measurements. Conclusion. The findings indicate that there is no particular benefit to the therapist in measuring more than one of the three variables if the purpose of the measurement is to serve as an indicator of ambulatory functional status for routine clinical assessment. Copyright © 2009 John Wiley & Sons, Ltd.
Refined carbothermal reduction approach for large scale, uniform growth of vertically aligned ZnO nanowires
Authors: Lee Ji‐Seung , Lee Dong‐Kyoon , Kim Jaehyun , Kim Junghan , Yang Heesun 
Published: January 2010

AbstractFor a large scale, uniform growth of vertically well‐aligned zinc oxide (ZnO) nanowires (NWs), a carbothermal reduction process was refined. Depending on how ZnO and graphite powders are loaded, i.e., stacked versus mixed states, the NWs show strikingly different growth behaviors. A newly introduced ZnO/graphite stacked source was found to be superior to a conventional mixed source with respect to the degree of vertical alignment and uniformity presumably due to the controlled (steady, slow) generation of Zn species at the ZnO/graphite boundaries. Effects of growth temperature, Ar gas flow, and weight of source materials on growth behaviors of ZnO NWs are investigated, and their optical and structural properties are characterized.
Superconducting and microstructural properties of Mg1−xAgxB2
Authors: Singh Kiran , Mohan Rajneesh , Kumar Naresh , Bhattacharya Shovit , Rayaprol Sudhindra , Gaur N. K. , Singh Ram K. 
Published: January 2010

AbstractA systematic study on the effect of silver (Ag) doping in magnesium diboride (MgB2) superconductor has been undertaken. A series of polycrystalline samples with composition Mg1−xAgxB2 (0 ≤ x ≤ 0.20) were synthesized by using the “in situ” solid state reaction method. All the samples were sintered at 850 °C for 2 h under the high purity argon flow. The room temperature X‐ray diffraction (XRD), low temperature resistivity (ρ‐T) measurements and field emission scanning electron microscopy (FE‐SEM) were performed to explore the phase purity, superconducting transition temperature, and microstructural properties, respectively.The XRD patterns show that Ag doping leads to the formation of MgAg phase. The relative intensity of MgAg phase increases with increasing Ag content. The ρ–T measurement shows that superconducting transition temperature (Tc) decreases slightly with Ag doping. All the samples have Tc between 38.5 K (x = 0.00) and 37 K (x = 0.20). The FE‐SEM images have revealed hexagonal shaped grains with an average grain size between 0.20 and 0.50 µm.
Simulation of the influence of thermal quenching on thermoluminescence glow‐peaks
Authors: Subedi B. , Kitis G. , Pagonis V. 
Published: January 2010

AbstractThe thermal quenching of luminescence efficiency is an effect which is present in many thermoluminescent (TL) materials. It causes a significant decrease of the luminescence signal and disturbs the shape of the glow‐peaks. Therefore, in principle, the thermoluminescence kinetics theory cannot describe TL glow‐peaks influenced by thermal quenching. In the present work a detailed simulation of the influence of the thermal quenching effect on thermoluminescence glow‐peaks is presented. Specifically we study the shift of the quenched glow‐peak with heating rate and the effect on the various heating rate methods, the influence on the symmetry factor and the kinetic order of the glow‐peak, and the effect of thermal quenching on the initial rise and peak shape methods for evaluating kinetic parameters. Furthermore, the evaluation of the thermal quenching parameters using the quenched glow‐peak and the possibility of using the conventional expression describing a single glow‐peak to fit the quenched glow peaks are also investigated.
DFT study on the second‐order nonlinear optical property of 12‐vertex close‐carborane derivatives
Authors: Fan Min , Sun Shi‐Ling , Qiu Yong‐Qing , Liu Xiao‐Dong , Su Zhong‐Min 
Published: January 2010

AbstractDensity functional theory (DFT) BHandHLYP method based on the 6‐31G(d) level was employed to optimize the structures of 12‐vertex substituted carboranes. The finite field (FF) method was adopted to study their second‐order nonlinear optical coefficients. Moreover, the electron spectra of systems were analyzed. The results show carboranes with alkali‐metal substituted have considerably large first hyperpolarizability (βtot) values which is 2–3 order of magnitude larger than that of unsubstituted carborane (14.5 a.u). For halogen and organic group substituted systems, however, the βtot values are only enhanced by one order of magnitude. The β values of carboranes obviously enhance after alkali‐metal substitution. This study may evoke the possibility to explore a new thriving area, i.e., alkali‐metal substituted carboranes for NLO application. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
RNA secondary structure alignment based on an extended binary coding method
Authors: Cao Zhi , Liao Bo , Li Renfa , Luo Jiawei , Zhu Wen 
Published: January 2010

AbstractRecently, we proposed a three‐dimensional cube representation of RNA secondary structure. An efficient method for mutation analysis has been proposed based on the introduced representation. According to the proposed three‐dimensional cube representations, we will introduce an extended binary coding method for RNA secondary structure alignment by converting the structure alignment to sequence alignment. Using our method, the result of structure alignment can be obtained quickly. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Adaptive smearing for Brillouin zone integration
Authors: Björkman Torbjörn , Grånäs Oscar 
Published: January 2010

AbstractWe suggest a simple scheme for automatically determining the width parameter of smearing methods of the Brillouin zone integration in electronic structure calculation. The scheme retains one free parameter that at any time can be eliminated by choosing a denser k‐space mesh until the desired accuracy is obtained. The tests are carried out in the context of Methfessel‐Paxton smearing. This adaptive Gaussian smearing (AGS) is easily implemented, variational with respect to partial occupancies and free from spurious occupancies that are negative or larger than one. Its convergence properties are similar to those obtained with the modified tetrahedron method for energy resolution of ≥0.1 meV. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Comparison of first‐trimester contingent screening strategies for Down syndrome
Authors: Sahota D. S. , Leung T. Y. , Chan L. W. , Law L. W. , Fung T. Y. , Chen M. , Lau T. K. 
Published: January 2010

AbstractObjectiveTo assess the relative performance of a multi‐stage first‐trimester screening protocol for fetal Down syndrome.MethodsData from 10 767 women who underwent combined ultrasound and biochemistry (BC) screening in the first trimester were reanalyzed using a contingent model approach. Amongst the 10 854 fetuses with known outcome, 32 had Down syndrome, 232 had other abnormalities and 10 590 were unaffected. Nuchal transluceny (NT), BC and combined (NT‐BC) gestational age‐specific risks were calculated for each individual using The Fetal Medicine Foundation risk calculation algorithms (Mixture Model and Biochemistry). Individual patients were categorized as at low, high or intermediate risk according to one of the following three strategies. In ‘Strategy‐NT‐BC’ initial screening was performed using both NT and BC. In ‘Strategy‐BC’ initial screening was undertaken using maternal serum markers followed by NT assessment in those with an intermediate risk (1 : 51 < risk $\leq 1:1000$) while in ‘Strategy‐NT’ initial screening was undertaken using NT followed by serum marker assessment in those with an intermediate risk (1 : 51 < risk $\leq 1:1000$). The nasal bone was assessed in those with an intermediate risk as the final stage in each of the three strategies. Those with an adjusted risk of 1 in 100 or higher after nasal bone assessment were reclassified as high risk. Detection and false‐positive rates were compared between differing strategies in our local population, and this analysis was also performed with the maternal age for our population standardized to the distribution found in England and Wales.ResultsIn our local population the detection rate for a 5% false‐positive rate using a combined screening policy (NT‐BC) was 88% (95% CI, 75.3–98.9%), and 2.3% had an absent nasal bone. The respective detection rate and false‐positive rate of the three multi‐stage screening strategies were: Strategy‐NT‐BC: 87.5 and 2.5%; Strategy‐BC: 87.5 and 5%; Strategy‐NT: 84.4 and 2.9%. In the contingent Strategy‐BC only 29% of those initially screened using serum markers required an NT scan. If the model were applied to a hypothetical obstetric population standardized to the maternal age distribution in England and Wales, the detection and false‐positive rates of the same three screening strategies would be: Strategy‐NT‐BC: 86.2 and 1.9%; Strategy‐BC: 82.8 and 4%; Strategy‐NT: 75.8 and 2.3%, respectively.ConclusionFirst‐trimester contingent screening provides detection and false‐positive rates comparable to those achieved using combined screening, but could be used to significantly reduce the number of scans performed. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Structured Ultrasonography Workshop for Breast Surgeons: Is It An Effective Training Tool?
Authors: Law Michael T. , Bennett Ian C. 
Published: January 2010

AbstractBackgroundEffective training is essential to ensure satisfactory performance in surgeon‐performed ultrasonography (US) and guided breast needle biopsies (USGBB). This study aimed to determine the efficacy of conducting a structured workshop in the teaching of breast US application and in guided biopsy techniques.MethodsConsenting participants of the US for Surgeons Workshop at the General Surgeons Australia 2008 Annual Scientific Meeting were recruited. The workshop was divided into theoretical and practical components. For the theoretical component, brief pretests were administered, followed by lecture series, and then posttests. For the practical component, preinstructional USGBBs performed on breast phantoms and turkey breasts implanted with simulated lesions were assessed, followed by tutorials; it was concluded with postinstructional biopsy assessment. Points were deducted for simulated chest wall hits (complications). Previous experience and training in USBGG were recorded. Pre‐ and postlecture/instructional results were compared and the correlation tested using Student’s t‐test (p < 0.05).ResultsIn all, 14 participants were recruited: 71% had no to moderate experience with USGBB. For the theoretical component, 33% improvement over the pretest (p < 0.001) was seen across all levels of experience. For the practical component, there was 56% improvement after instruction (p = 0.001), which was most marked in the moderate experience group (83%, p = 0.03). Two complications were recorded for the least experienced group prior to instructions, but no complications were seen following instructions.ConclusionsStructured workshops are effective for training surgeons in US application and USGBB and should be considered as part of standardized training guidelines and credentialing. Theory and practical components demonstrated similar efficacy and should be considered integral components in training programs. Formal training decreases complication rates, especially among the inexperienced.
Papillary Thyroid Microcarcinoma: Extrathyroidal Extension, Lymph Node Metastases, and Risk Factors for Recurrence in a High Prevalence of Goiter Area
Authors: Lombardi Celestino P. , Bellantone Rocco , De Crea Carmela , Paladino Nunzia C. , Fadda Guido , Salvatori Massimo , Raffaelli Marco 
Published: January 2010

AbstractBackgroundAlthough papillary thyroid microcarcinoma (PTMC) is diagnosed with increasing frequency, the best therapeutic option and follow‐up protocol have not been established yet, especially in the case of incidental diagnosis. We reviewed our series of patients with PTMC to determine risk factors for recurrence in an area where there is a high prevalence of goiter.MethodsThe medical records of all patients who underwent thyroidectomy with a final pathology report of PTMC between October 2002 and June 2007 were reviewed. PTMC was defined as a papillary thyroid carcinoma 10 mm or less in diameter. Follow‐up evaluation was obtained by outpatient consultation and/or telephone interview.ResultsIn a series of 2,220 patients who underwent thyroidectomy for a thyroid carcinoma, 933 had a PTMC. Diagnosis was incidental in 704 patients (75.5%). Upon multivariate analysis, tumor size, nonincidental diagnosis, and neck node metastases at diagnosis were independent risk factors for extracapsular spread (ECS), while ECS, multifocal disease, and number of removed lymph nodes were independent risk factors for lymph node metastases at diagnosis. Follow‐up evaluation was completed in 287 patients, 9 (3.1%) of whom experienced recurrence. The number of removed and metastasized nodes at first operation and the length of the follow‐up were independent risk factors for recurrent disease.ConclusionsIncidental diagnosis of PTMC is frequent in a high prevalence of goiter area. PTMC shows a variable degree of aggressiveness. Management protocols should be based on patient‐ and tumor‐related prognostic factors, as for larger tumors.
Vitamin D3 Deficiency is Associated with Late‐Onset Hypocalcemia After Minimally Invasive Parathyroidectomy in a Vitamin D Borderline Area
Authors: Lang Brian Hung‐Hin , Lo Chung‐Yau 
Published: January 2010

AbstractBackgroundConcurrent vitamin D3 deficiency is common in primary hyperparathyroidism (pHPT). We aimed to examine the clinicopathologic features and short‐term outcomes of vitamin D3‐deficient patients after minimally invasive parathyroidectomy (MIP).MethodsOver 2‐year period, 80 consecutive MIP patients had preoperative‐fasting 25‐hydroxyvitamin D3 (25OHD3) checked. Forty‐five patients had a 25OHD3 level <20 ng/ml and were defined as deficient. Intraoperative parathyroid hormone (IOPTH) assay was used for all MIP. Postoperative adjusted calcium (Ca) was checked at 6, 16 (with intact PTH), and 24 h. Oral calcium and vitamin D supplements were given if hypocalcemic symptoms developed or Ca < 2.00 mmol/l. Late‐onset hypocalcemia (LOH) was defined as symptoms developed after 24 h.ResultsBoth deficient and nondeficient groups had similar demographic data and bone density scores. The deficient group had significantly higher PTH (190 vs. 121 pg/ml, p = 0.015). Although IOPTH in the deficient group were higher at induction and 0 min after excision, the percentage drop from induction to 10 min after excision was similar. Ca was similar at 6 and 16 h in the two groups but was significantly lower in the deficient group at 24 h (2.10 vs. 2.45 mmol/l, p = 0.033). At 1 week, the proportion of LOH was significantly higher in the deficient group (12/42 vs. 3/34, p = 0.043) and in those with preoperative PTH > 100 pg/ml (15/57 vs. 0/19, p = 0.013).ConclusionsVitamin D3 deficiency was associated with a higher preoperative PTH level and a greater risk of LOH after MIP. However, the likely cause of LOH remains unclear as both low preoperative vitamin D3 and high PTH levels could be responsible.
The Plackett–Burman Design for Evaluating the Production of Polyunsaturated Fatty Acids by Physcomitrella patens
Authors: Chodok Pichit , Kanjana‐Opas Akkharawit , Kaewsuwan Songsri 
Published: January 2010

AbstractIdentification of the parameters that had significant effects on polyunsaturated fatty acids (PUFAs) and biomass production by the moss Physcomitrella patens was performed using nine culture variables (temperature, agitation speed, pH, sucrose, di‐ammonium tartrate, CaCl2·2H2O, MgSO4·7H2O, KH2PO4 and KNO3) with the statistical design technique of Plackett–Burman. Statistical analysis revealed that two physical variables (pH and temperature) had significant effects on the production of both biomass and PUFAs (linoleic acid, LA; γ‐linolenic acid, GLA; α‐linolenic acid, ALA; eicosadienoic acid, EDA; di‐homo‐γ‐linolenic acid, DHGLA; arachidonic acid, ARA; eicosapentaenoic acid, EPA). Three nutritional variables (sucrose, CaCl2 and MgSO4) had an influence only on the production of some of the PUFAs. Of the two levels used in this study, higher concentrations of sucrose had a positive effect on LA, ARA and EPA production, whereas higher concentrations of metal ions (CaCl2 and MgSO4) had a negative effect only on ARA and EPA production. After adjustment by multiple linear regression, it can be concluded that pH, temperature, sucrose, CaCl2 and MgSO4 were the most statistically significant parameters for the growth of P. patens and for PUFA production by this moss.
Chemical Composition and Oxidative Stability of Selected Plant Oils
Authors: Szterk Arkadiusz , Roszko M. , Sosińska E. , Derewiaka D. , Lewicki P. P. 
Published: January 2010

AbstractScientific data on the oxidative stability of borage oil, Camelina sativa oil, linseed oil, evening primrose oil and pumpkin seed oil are scarce. Chemiluminescence (CL) methods most commonly used to determine the oxidative stability of oils include measurement of hydroperoxide, intensity of light emitted during the accelerated oxidation process performed at high (>100 °C) temperatures or assisted by forced flow of air/oxygen through the sample. The aim of this study was to investigate the chemical composition and oxidative stability of selected vegetable oils available on the Polish market. Oxidative stability was determined using a fast, novel chemiluminescence‐based method, in which light emitted during oxidation process conducted at 70 °C in the presence of some catalyzing Fe2+ ions is measured. A reaction of the applied type has not been reported so far. High contents of tocopherols and phytosterols were found in the analyzed oil samples. Oxidative stability of the samples was in most cases higher than the stability of refined rapeseed oil, a relatively stable substance from the oxidation point of view.