bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast determination of ethambutol in pharmaceutical formulations using capillary electrophoresis with capacitively coupled contactless conductivity detection
Authors: da Silva José Alberto Fracassi , de Castro Nathan Vitorazzi , de Jesus Dosil Pereira , Faria Adriana F. , De Souza Marcus V. N. , de Oliveira Marcone Augusto Leal 
Published: January 2010

AbstractA method for the determination of ethambutol (EMB), a first‐line drug against tuberculosis, based on CE with capacitively coupled contactless conductivity detection is proposed. The separation of EMB and its main product of degradation were achieved in less than 3 min with a resolution of 2.0 using a BGE composed of 50 mmol/L histidine and 30 mmol/L MES, pH 6.30. By raising the pH to 8.03, the analysis time was reduced to 1.0 min, but with a significant loss of resolution (0.7). Using the best separation conditions, linearity of 0.9976 (R2, five data points), sensitivity of 1.26×10−4 V min μmol−1 L, and LOD and quantification of 23.5 and 78.3 μmol/L, respectively, were obtained. Recoveries at four levels of concentration ranged from 95 to 102% and the concentration range studied ranged from 100 to 500 μmol/L. The results obtained for the determination of EMB in pharmaceutical formulations were compared with those obtained by using CE with photometric detection.
Analysis of effect of electrolyte types on electrokinetic energy conversion in nanoscale capillaries
Authors: Chein Reiyu , Tsai Kunyong , Yeh Liying 
Published: January 2010

AbstractAn analytical study on the effect of electrolyte types on the electrokinetic energy conversion is presented using nanoscale cylindrical capillary, which is either positively or negatively charged. The sign of surface charge determines the role and concentration magnitude of ions in the capillary and the energy conversion performance. Our study shows that the electrokinetic energy conversion performance (maximum efficiency, pressure rise and streaming potential) are approximately identical for 1:1 (KCl), 2:1 (CaCl2) and 3:1 (LaCl3) electrolytes when capillary is positively charged. For negatively charged capillary, energy conversion performance degrades significantly with the increase of counter‐ion valence. For both positively and negatively charged capillaries, higher maximum efficiency can be resulted in low bulk concentration and surface charge density regimes. However, high maximum pressure rise generation for the pumping is found in the low bulk concentration and high surface charge density regimes. For the electric power generation, higher maximum streaming potential is found when both bulk concentration and surface charge density are low.
The proteome of lentil (Lens culinaris Medik.) seeds: Discriminating between landraces
Authors: Scippa Gabriella Stefania , Rocco Mariapina , Ialicicco Manuela , Trupiano Dalila , Viscosi Vincenzo , Di Michele Michela , Arena Simona , Chiatante Donato , Scaloni Andrea 
Published: January 2010

AbstractLentil (Lens culinaris Medik.) is one of the most ancient crops of the Mediterranean region used for human nutrition; an extensive differentiation of L. culinaris over millennia has resulted in a number of different landraces. As a consequence of environmental and socio‐economic issues, the disappearance of many of them occurred in more recent times. To investigate the potential of proteomics as a tool in phylogenetic studies, testing the possibility to identify specific markers of different plant landraces, 2‐D gel electrophoretic maps of mature seeds were obtained from seven lentil populations belonging to a local ecotype (Capracotta) and five commercial varieties (Turca Rossa, Canadese, Castelluccio di Norcia, Rascino and Colfiorito). 2‐DE analysis resolved hundreds of protein species in each lentil sample, among which only 122 were further identified by MALDI‐TOF PMF and/or nanoLC‐ESI‐LIT‐MS/MS, probably as a result of the poor information available on L. culinaris genome. A comparison of these maps revealed that 103 protein spots were differentially expressed within and between populations. The multivariate statistical analyses carried out on these variably expressed spots showed that 24 protein species were essential for population discrimination, thus determining their proposition as landrace markers. Besides providing the first reference map of mature lentil seeds, our data confirm previous studies based on morphological/genetic observations and further support the valuable use of proteomic techniques as phylogenetic tool in plant studies.
A simple method to determine the surface charge in microfluidic channels
Authors: Mampallil Dileep , van den Ende Dirk , Mugele Frieder 
Published: January 2010

AbstractWe study EOF through microchannels, made of glass or glass‐PDMS, by displacing an electrolyte solution at given concentration with the same electrolyte at a different concentration via an external electric field. When a constant voltage is applied over the channel, the electric current through the channel varies during the displacement process. We propose a simple analytical model that describes the time dependence of the current regardless of the concentration ratio chosen. With this model, which is applicable beyond the Debye–Hückel limit, we are able to quantify the EOF velocity and to determine the surface charge on the microchannel walls from the measured current behavior, as well as the zeta potential at given local electrolyte concentration.
The Fanconi anemia pathway promotes DNA glycosylase‐dependent excision of interstrand DNA crosslinks
Authors: Macé‐Aimé Gaëtane , Couvé Sophie , Khassenov Bekbolat , Rosselli Filippo , Saparbaev Murat K. 
Published: January 2010

AbstractFanconi anemia (FA) is a recessive cancer prone syndrome featuring bone marrow failure and hypersensitivity to DNA interstrand crosslinks (ICLs) and, to a milder extension, to ionizing radiation and oxidative stress. Recently, we reported that human oxidative DNA glycosylase, NEIL1 excises with high efficiency the unhooked crosslinked oligomer within three‐stranded DNA repair intermediate induced by photoactivated psoralen exposure. Complete reconstitution of repair of the ICL within a three‐stranded DNA structure shows that it is processed in the short‐patch base excision repair (BER) pathway. To examine whether the DNA damage hypersensitivity in FA cells follows impaired BER activities, we measured DNA glycosylase and AP endonuclease activities in cell‐free extracts from wild‐type, FA, and FA‐corrected cells. We showed that immortalized lymphoid cells of FA complementation Groups A, C, and D and from control cells from normal donors contain similar BER activities. Intriguingly, the cellular level of NEIL1 protein strongly depends on the intact FA pathway suggesting that the hypersensitivity of FA cells to ICLs may, at least in part, arise from downregulation or degradation of NEIL1. Consistent with this result, plasmid‐based expression of the FLAG‐tagged NEIL1 protein partially complements the hypersensitivity FA cells to the crosslinking agents exposures, suggesting that NEIL1 specifically complements impaired capability of FA cells to repair ICLs and oxidative DNA damage. These findings shed light to how the FA pathway may regulate DNA repair proteins and bring explanation for the long‐time disputed problem of the oxidative stress sensitive phenotype of FA cells. Environ. Mol. Mutagen. 2010. © 2010 Wiley‐Liss, Inc.
Brain responses to success and failure: Direct recordings from human cerebral cortex
Authors: Jung Julien , Jerbi Karim , Ossandon Tomas , Ryvlin Philippe , Isnard Jean , Bertrand Olivier , Guénot Marc , Mauguière François , Lachaux Jean‐Philippe 
Published: January 2010

AbstractEvaluating the outcome of our own actions is a fundamental process by which we adapt our behavior in our interaction with the external world. fMRI and electrophysiological studies in monkeys have found feedback‐specific responses in several brain regions, unveiling facets of a large‐scale network predominantly distributed in the frontal lobes. However, a consensus has yet to be reached regarding the exact contribution of each region. The present study benefited from intracerebral EEG recordings in epileptic patients to record directly the neural activity in each of those frontal structures in response to positive and negative feedback. Both types of feedback induced a sequence of high‐frequency responses (>40 Hz) in a widespread network involving medial frontal cortex, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), and insular cortex. The pre‐supplementary motor area (pre‐SMA), DLPFC, and lateral OFC showed higher activation in response to negative feedback, while medial OFC and dorsal anterior cingulate cortex (dACC) were more responsive to positive feedback. Responses in the medial prefrontal cortex (pre‐SMA and dACC) were sustained (lasting more than 1,000 ms), while responses in the DLPFC, insula, and the OFC were short lasting (less than 800 ms). Taken together, our findings show that evaluating the outcome of our actions triggers γ‐range activity modulations in several frontal and insular regions. Moreover, we found that the timing and amplitude of those γ‐band responses reveal fine‐scale dissociations between the neural dynamics of positive versus negative feedback processing. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Dynamics and equilibrium in a structural model of wide‐body commercial aircraft markets
Authors: Smith Loren K. 
Published: January 2010

SUMMARYThis paper develops and estimates a dynamic equilibrium model of the market for new and used commercial aircraft. The model is estimated by maximum simulated likelihood using data on wide‐body aircraft owners and prices for transactions occurring 1978‐1997. The importance of explicitly modeling dynamics and equilibrium in new and used markets for durable goods is illustrated in two counterfactual experiments. Estimates of the structural model are used to show that implementing an investment tax credit not only increases demand for new wide‐body aircraft by the airlines that receive the tax credit, but also increases the number of new wide‐body aircraft owned by airlines not directly affected by the policy. Further, the model indicates that a policy which improves the efficiency of secondary markets for used wide‐body aircraft will also stimulate demand for new wide‐body aircraft. Copyright © 2010 John Wiley & Sons, Ltd.
Array of amorphous calcium phosphate particles improves cellular activity on a hydrophobic surface
Authors: Kim InAe , Kim Hyun Jung , Kim Hyun‐Man 
Published: January 2010

AbstractPoor interaction between cells and surfaces, especially hydrophobic surfaces, results in delayed proliferation and increased apoptosis due to low cell adhesion signaling. To improve cell adhesion, hydrophilic array of amorphous calcium phosphate (ACP) was fabricated on a surface. A phosphate‐buffered solution containing calcium ions was prepared at low temperature to prevent spontaneous precipitation. Then, the ion solution was heated to generate nuclei of ACP nanoparticles. The ACP nanoparticles adhered to the hydrophobic polystyrene surface forming an array composed of ACP particles. Multiple treatments of these nuclei with fresh CaP ion solutions increased the diameter and decreased the solubility of ACP particles enough to mediate cellular adhesion. The particle density in the array was dependent on the ion concentration of the CaP ion solutions. The ACP array improved a wide variety of activities when osteoblastic MC3T3‐E1 cells were cultured on the ACP array fabricated on a hydrophobic bacteriological dish surface, compared to those cultured without the ACP array in vitro. The use of ACP array resulted in a lower apoptosis and also increased the spreading of cells to form stress fibers and focal contacts. Cells cultured on the ACP array proliferated more than cells cultured on a hydrophobic surface without the ACP array. The ACP array increased the expression of markers of differentiation in osteoblast. These results indicate that an array of ACP can be used as a coating material for enhancing biocompatibility in tissue engineering or biomaterials rather than modifying the surface with organic molecules. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
The importance of cortical bone orthotropicity, maximum stiffness direction and thickness on the reliability of mandible numerical models
Authors: Apicella Davide , Aversa Raffaella , Ferro Fabrizia , Ianniello Domenico , Apicella Antonio 
Published: January 2010

AbstractAim: To identify mechanical and geometrical variables affecting the biofidelity of numerical models of human mandible. Computed results sensibility to cortical bone orthotropy and thicknesses is investigated. Methods: Two mandible numerical models of different bone complexities are setup. In the low‐complexity model, cortical bone is coupled with isotropic materials properties; constant thickness for cortical bone is adopted along the mandible structure. In the higher complexity model, the cortical bone is considered as an orthotropic material according to an independent mechanical characterization performed on fresh human dentate mandibles. Cortical thickness distribution, the values of the principal elastic moduli and principal directions of orthotropy are considered as piecewise heterogeneous. Forces for masseter (10 N), medial pterigoid (6 N), anterior (4 N) and posterior (4 N) temporalis muscles are applied to the models. Computed strains fields are compared with those experimentally measured in an independent test performed on a real human mandible in the same loading conditions. Results: Under closure muscles forces both models shows similar strain distribution. On the contrary, strain fields values are significantly different between the presented models. Conclusions: The mandible structure is sensible to compact bone orthotropy and thickness at the facial side of condylar neck, retro molar area and at the lingual side of middle portion of the corpus in molars area, anterior margin of the ramus. In these areas, it is advisable to use orthotropic properties for cortical bone to accurately describe the strain state. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Combined drug release from biodegradable bilayer coating for endovascular stents
Authors: Gagliardi M. , Silvestri D. , Cristallini C. , Guadagni M. , Crifaci G. , Giusti P. 
Published: January 2010

AbstractIn this work, the characterization of a biodegradable bilayer system, used as controlled and combined drug delivery platform, is reported. For this aim, a bilayer system, composed of poly(lactic‐co‐glycolic acid) and poly(3‐hydroxybutyric‐co‐3‐hydroxyvaleric acid), was investigated under physicochemical and functional aspects by evaluating polymer/polymer and polymer/stent material interactions, the kinetic of in vitro degradation, and drug release properties, comparing results with the monolayer reference systems. Obtained results showed that the bilayer system allowed increasing the total amount of eluted Tacrolimus and Paclitaxel drugs with respect to the monolayer systems in the considered testing period and conditions. This evidence was associated to a faster degradation of the tested copolymers in the bilayered configuration, excluding a synergic effect of two drugs on delivery performance. In addition, a macromolecular relaxation process was identified to govern the PLX release from poly(lactic‐co‐glycolic acid), whereas a pure Fickian diffusion occurred in the delivery of Tacrolimus from poly(3‐hydroxybutyric‐co‐3‐hydroxyvaleric acid). © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Genome-wide pleiotropy of osteoporosis-related phenotypes: The framingham study
Authors: Karasik David , Hsu Yi-Hsiang , Zhou Yanhua , Cupples L Adrienne , Kiel Douglas P , Demissie Serkalem 
Published: January 2010

Abstract
Genome-wide association studies offer an unbiased approach to identify new candidate genes for osteoporosis. We examined the Affymetrix 500K + 50K SNP GeneChip marker sets for associations with multiple osteoporosis-related traits at various skeletal sites, including bone mineral density (BMD, hip and spine), heel ultrasound, and hip geometric indices in the Framingham Osteoporosis Study. We evaluated 433,510 single-nucleotide polymorphisms (SNPs) in 2073 women (mean age 65 years), members of two-generational families. Variance components analysis was performed to estimate phenotypic, genetic, and environmental correlations (ρP, ρG, and ρE) among bone traits. Linear mixed-effects models were used to test associations between SNPs and multivariable-adjusted trait values. We evaluated the proportion of SNPs associated with pairs of the traits at a nominal significance threshold α = 0.01. We found substantial correlation between the proportion of associated SNPs and the ρP and ρG (r = 0.91 and 0.84, respectively) but much lower with ρE (r = 0.38). Thus, for example, hip and spine BMD had 6.8% associated SNPs in common, corresponding to ρP = 0.55 and ρG = 0.66 between them. Fewer SNPs were associated with both BMD and any of the hip geometric traits (eg, femoral neck and shaft width, section moduli, neck shaft angle, and neck length); ρG between BMD and geometric traits ranged from −0.24 to +0.40. In conclusion, we examined relationships between osteoporosis-related traits based on genome-wide associations. Most of the similarity between the quantitative bone phenotypes may be attributed to pleiotropic effects of genes. This knowledge may prove helpful in defining the best phenotypes to be used in genetic studies of osteoporosis. © 2010 American Society for Bone and Mineral Research
Percent fat mass is inversely associated with bone mass and hip geometry in rural Chinese adolescents
Authors: Hong Xiumei , Arguelles Lester M , Liu Xin , Tsai Hui-Ju , Hsu Yi-Hsiang , Wang Binyan , Zhang Shanchun , Li Zhiping , Tang Gengfu , Liu Xue , Yang Jianhua , Xu Xiping , Langman Craig , Wang Xiaobin 
Published: January 2010

Abstract
This study was an attempt to examine the phenotypic, genetic, and environmental correlations between percent fat mass (PFM) and bone parameters, especially hip geometry, among 786 males and 618 females aged 13 to 21 years from a Chinese twin cohort. PFM, bone area (BA), bone mineral content (BMC), cross-sectional area (CSA), and section modulus (SM) were obtained by dual-energy X-ray absorptiometry. Multiple linear regression models were used to assess the PFM-bone relationships. A structural equation model for twin design was used to estimate genetic/environmental influences on individual phenotype and phenotypic correlations. After controlling for body weight and other pertinent covariates, we observed inverse associations between PFM and bone parameters: Compared with the lowest age- and gender-specific tertile of PFM, males in the highest tertile of PFM had lower measures of whole-body-less-head BA (WB-BA), lumbar spine BA (L2–L4-BA), total-hip BA (TH-BA), total-hip BMC, CSA, and SM (p &lt; .005 for all, adjusted p &lt; .05). Similar inverse associations were observed in females for all the preceding parameters except WB-BA and L2–L4-BA. These associations did not vary significantly by Tanner stages. In both genders, the estimated heritabilities were 80% to 86% for BMC, 67% to 80% for BA, 74% to 77% for CSA, and 64% for SM. Both shared genetics and environmental factors contributed to the inverse PFM-bone correlations. We conclude that in this sample of relatively lean Chinese adolescents, at a given body weight, PFM is inversely associated with BA, BMC, and hip geometry in both genders, and such associations are attributed to both shared genetic and environmental factors. © 2010 American Society for Bone and Mineral Research
Familial resemblance and diversity in bone mass and strength in the population are established during the first year of postnatal life
Authors: Wang Qingju , Alén Markku , Lyytikäinen Arja , Xu Leiting , Tylavsky Fran A , Kujala Urho M , Kröger Heikki , Seeman Ego , Cheng Sulin 
Published: January 2010

Abstract
Familial resemblance and diversity in bone structure and strength in adulthood are determined in part during growth. Whether these characteristics are established during gestation or shortly after birth is not known. Total-body, lumbar spine, and femoral neck size and mass and indices of tibial bending strength and distal radial compressive strength were measured using bone densitometry and quantitative computed tomography in 236 girls at 18.5 years of age. Among them, 219, 141, and 105 girls had crown-heel length (CHL) and weight recorded at birth and at 6 and 12 months of age, and then height and weight were recorded at 3, 5, 10, 13, and 15 years of age in 181, 176, 127, 111, and 228 girls, respectively. Of these girls, 101 and 93 girls also had bone structure assessed at 11 and 13 years of age, respectively. Similar bone measurements were made once in 78 mother-father pairs. CHL and weight at birth did not correlate or did so weakly with bone traits in girls at 18 years of age. By contrast, CHL at 6 months correlated with the height, bone traits, and strength at puberty and at 18 years of age (r = 0.24–0.56, p &lt; .001) in girls and with their parents' height and bone traits (r = 0.15–0.37, p &lt; .05). When the girls' CHL at 6 months was stratified into quartiles, the absolute and relative differences in bone traits observed at puberty (∼11.5 years) were maintained as these traits tracked during the ensuing 7 years. Similarly, weight at 6 months correlated with the girls' bone traits at puberty and 18 years of age (r = 0.22–0.55, p &lt; .05). During puberty and at 18 years of age, the girls' bone traits correlated with the corresponding traits in their parents (r = 0.32–0.43, p &lt; .01). It is concluded that familial resemblance in bone structural strength and the position of an individual's bone traits relative to others in adulthood are likely to be established during the first year of life. Thus susceptibility to bone fragility late in life has its antecedents established early in life. © 2010 American Society for Bone and Mineral Research