bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and Validation of a Routine Multiresidue Method for Determining 140 Pesticides in Fruits and Vegetables by Gas Chromatography/Tandem Quadrupole Mass Spectrometry
Authors: Walorczyk Stanisław , Drożdżyński Dariusz 
Published: November 2011

Abstract
A GC/tandem quadrupole MS/MS method was developed and validated for the determination of the residues of 140 pesticides in fruits and vegetables. Pesticides were extracted from samples by using a miniaturized acetonitrile-based extraction technique known as the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Validation studies were carried out on carrots, tomatoes, and strawberries. In order to reduce systematic errors due to a matrix-induced effect, quantification was carried out using matrix-matched standard calibration curves. The recovery and precision results satisfied the European Union criteria (i.e., average recoveries were in the range 70–120% with RSDs ≤20%) for 125 of the 140 pesticides at a spiking level of 0.01 mg/kg. At the higher spiking levels, there were just two instances of overall average recovery &lt;70% (chlorothalonil and captan). The measurement uncertainty was estimated following a "top down" approach as being 21 and 35%, on average, based on validation and ongoing recovery data, respectively (coverage factor k = 2, confidence level 95%). Practical application to 541 samples of apples, tomatoes, strawberries, cucumbers, currants, mushrooms, carrots, peppers, pears, onions, and gooseberries under strict QC conditions demonstrated the ruggedness of the total procedure.
Development and Validation of a Reversed-Phase Column Liquid Chromatographic Method for the Determination of Five Cephalosporins in Pharmaceutical Preparations
Authors: Elkady Ehab F , Abbas Samah S 
Published: November 2011

Abstract
A new, simple, rapid, and precise RP-HPLC method has been developed and validated for the determination of five cephalosporins, namely, cefalexin, cefoperazone, ceftriaxone, ceftazidime, and cefepime. The method has been applied successfully for simultaneous determination of cefalexin in a binary mixture with sodium benzoate in a suspension, and cefoperazone in a binary mixture with sulbactam in vials. Chromatographic separation was achieved on a Waters μBondapak® C18 column (250 × 4.6 mm id, 10 μm particle size) using the mobile phase monobasic potassium phosphate (50 mM, pH 4.6)–acetonitrile (80 + 20, v/v) with UV detection. A flow rate of 1 mL/min was applied. Linearity, accuracy, and precision were found to be acceptable over the concentration range of 30–300, 3–30, and 15–120 μg/mL for the studied cephalosporins, sodium benzoate, and sulbactam, respectively. The optimized method proved to be specific, robust, and accurate for QC of the cited drugs in their pharmaceutical preparations.
Analytical Parameters of the Microplate-Based ORAC-Pyrogallol Red Assay
Authors: Ortiz Rocío , Antilén Mónica , Speisky Hernán , Aliaga Margarita E , López-Alarcón Camilo 
Published: November 2011

Abstract
The analytical parameters of the microplate-based oxygen radicals absorbance capacity (ORAC) method using pyrogallol red (PGR) as probe (ORAC-PGR) are presented. In addition, the antioxidant capacity of commercial beverages, such as wines, fruit juices, and iced teas, is estimated. A good linearity of the area under the curve (AUC) versus Trolox concentration plots was obtained [AUC = (845 ± 110) + (23 ± 2) [Trolox, μM], R = 0.9961, n = 19]. QC experiments showed better precision and accuracy at the highest Trolox concentration (40 μM) with RSD and REC (recuperation) values of 1.7 and 101.0%, respectively. When red wine was used as sample, the method also showed good linearity [AUC = (787 ± 77) + (690 ± 60) [red wine, μL/mL]; R = 0.9926, n = 17], precision and accuracy with RSD values from 1.4 to 8.3%, and REC values that ranged from 89.7 to 103.8%. Additivity assays using solutions containing gallic acid and Trolox (or red wine) showed an additive protection of PGR given by the samples. Red wines showed higher ORAC-PGR values than white wines, while the ORAC-PGR index of fruit juices and iced teas presented a great variability, ranging from 0.6 to 21.6 mM of Trolox equivalents. This variability was also observed for juices of the same fruit, showing the influence of the brand on the ORAC-PGR index. The ORAC-PGR methodology can be applied in a microplate reader with good linearity, precision, and accuracy.
A novel familial 11p15.4 microduplication associated with intellectual disability, dysmorphic features, and obesity with involvement of the ZNF214 gene
Authors: Sofos Elvera , Pescosolido Matthew F. , Quintos Jose B. , Abuelo Dianne , Gunn Shelly , Hovanes Karine , Morrow Eric M. , Shur Natasha 
Published: November 2011

AbstractWe evaluated a patient with mild intellectual disability, obesity, overgrowth, and dysmorphic features. Array comparative genomic hybridization (aCGH) analysis showed a single copy number increase of a BAC clone in the 11p15.4 region. Oligonucleotide aCGH refined the duplication to approximately 2.29 megabases (Mb) in size. Testing the parents revealed that the father, who had learning disabilities and overgrowth, also had the 11p15.4 duplication, and the mother had a normal microarray. In addition, the patient's brother and grandmother all share clinical features with the proband and tested positive for the duplication. The duplicated region (Chr11:6,934,067‐9,220,605) encompasses 29 genes, including the ZNF214 gene, which has been postulated to play a role in Beckwith–Wiedemann syndrome [Alders et al., 2000]. This three‐generation pedigree outlines features of a novel microduplication syndrome. © 2011 Wiley Periodicals, Inc.
GRIK4/KA1 protein expression in human brain and correlation with bipolar disorder risk variant status
Authors: Knight Helen M. , Walker Robert , James Rachel , Porteous David J. , Muir Walter J. , Blackwood Douglas H.R. , Pickard Benjamin S. 
Published: November 2011

AbstractThe kainate class of ionotropic glutamate receptors is involved in the regulation of neuronal transmission and synaptic plasticity. Previously we reported that a deletion variant within the gene GRIK4, which encodes the KA1 kainate receptor subunit, was associated with a reduced risk of bipolar disorder and increased GRIK4 mRNA abundance. Using a high resolution immunohistochemistry technique, we characterized KA1 protein localization in human brain and performed a genotype–protein expression correlation study. KA1 was expressed in specific populations of neuronal cells in the cerebellum and all layers of the frontal and parahippocampal cortices. In the hippocampus, strong KA1 expression was observed in the stratum pyramidale and stratum lucidum of CA3 and CA2, in cell processes in CA1, in the neuropil of the CA4 region, in polymorphic cells including mossy fiber neurons in the hilus, and dentate gyrus (DG) granule cells. Mean counts of KA1 positive DG granule cells, hippocampal CA3 pyramidal cells, and layer 1 of the frontal cortex were significantly increased in subjects with the deletion allele (P = 0.0005, 0.018, and 0.0058, respectively) compared to subjects homozygous for the insertion. Neuronal expression levels in all regions quantified were higher in the deletion group. These results support our hypothesis that the deletion allele affords protection against bipolar disorder through increased KA1 protein abundance in neuronal cells. Biological mechanisms which may contribute to this protective effect include KA1 involvement in adult hippocampal neurogenesis, HPA axis activation, or plasticity processes affecting neuronal circuitry. © 2011 Wiley Periodicals, Inc.
Detection of anti‐Leptospiraantibodies in captive nonhuman primates from Salvador, Brazil
Authors: Pinna Melissa H. , Martins Gabriel , Pinheiro Ana Carla O. , Almeida Daniela S. , Oriá Arianne P. , Lilenbaum Walter 
Published: November 2011

AbstractLeptospirosis is a widely distributed zoonosis that affects several species of domestic and wild animals. Under captive conditions, Leptospirosis is a potential problem because the physical conditions in most zoos and research centers cannot prevent the captive animals from being exposed to rodents, raccoons, opossums, and other local wildlife that are known carriers. Yet, despite the potential risk, animals that are destined for reintroduction into the wild are not routinely tested for anti‐Leptospiraantibodies before their release. The purpose of this study was to determine the occurrence of anti‐Leptospiraantibodies in captive New World monkeys that were housed in the Wild Animals Screening Center in Salvador, Brazil. Blood samples were collected from 44 monkeys (28Callithrix jacchus, eightCallithrix pennicilata, and eightCebussp.). The animals were screened for antibodies with the microscopic agglutination test. Twenty‐five (56.8%) primates were seroreactive, with Icterohaemorrhagiae being the most frequent serogroup. None of the monkeys, however, presented clinical signs of leptospirosis. Thus, seroreactivity with low titers in asymptomatic animals, as observed in this study, suggests exposure to the agent. The unexpected predominance of the serogroup Icterohaemorrhagiae further suggests that exposure to this serogroup occurred in captivity. Therefore, the dangerous possibility cannot be ignored that reintroduced monkeys will carry the leptospiral serovars into wild populations. In conclusion, primates exposed to urban serovars before their release from captivity represent a potentially significant health risk to wild populations. Am. J. Primatol. 74:8–11, 2012. © 2011 Wiley Periodicals, Inc.
Lumbar lordosis of extinct hominins
Authors: Been Ella , Gómez‐Olivencia Asier , Kramer Patricia A. 
Published: November 2011

AbstractThe lordotic curvature of the lumbar spine (lumbar lordosis) in humans is a critical component in the ability to achieve upright posture and bipedal gait. Only general estimates of the lordotic angle (LA) of extinct hominins are currently available, most of which are based on the wedging of the vertebral bodies. Recently, a new method for calculating the LA in skeletal material has become available. This method is based on the relationship between the lordotic curvature and the orientation of the inferior articular processes relative to vertebral bodies in the lumbar spines of living primates. Using this relationship, we developed new regression models in order to calculate the LAs in hominins. The new models are based on primate group‐means and were used to calculate the LAs in the spines of eight extinct hominins. The results were also compared with the LAs of modern humans and modern nonhuman apes. The lordotic angles of australopithecines (41° ± 4), H. erectus (45°) and fossil H. sapiens (54° ± 14) are similar to those of modern humans (51° ± 11). This analysis confirms the assumption that human‐like lordotic curvature was a morphological change that took place during the acquisition of erect posture and bipedalism as the habitual form of locomotion. Neandertals have smaller lordotic angles (LA = 29° ± 4) than modern humans, but higher angles than nonhuman apes (22° ± 3). This suggests possible subtle differences in Neandertal posture and locomotion from that of modern humans. Am J Phys Anthropol, 2012. © 2011 Wiley Periodicals, Inc.
Degradation assessment of LDPE multilayer films used as a greenhouse cover: Natural and artificial aging impacts
Authors: Dehbi Abdelkader , Mourad Abdel‐Hamid I. , Bouaza Amar 
Published: November 2011

AbstractThis article focuses on the assessment and understanding of the mechanism of natural and artificial aging processes of a triple‐layer film made of low‐density polyethylene (LDPE) used as greenhouse cover. The film material contains color dye and ultraviolet–A (UV–A) and infrared (IR) stabilizers and antioxidant. The combined effect of temperature variations and UV–A radiations, of the natural and artificial aging, on the physical properties (free surface energy and yellow color measurements), mechanical behavior (tensile tests), thermal stability (TGA and DSC analysis), and structural stability (FTIR analysis) was investigated. The natural aging was conducted on a greenhouse, located in northern Algeria, over a period of 7 months. However, the artificial aging was performed at four different agricultural greenhouse simulating conditions of temperature and UV–A radiation (namely, at 40°C, 40°C with UV–A, 50°C, and 50°C with UV–A) for periods of aging up to 5486 h (7.6 months). The results revealed that, the maximum loss of the yellow color additives occurs at 2981 h under the natural aging process and at 2440, 1096, 1340, and 121 h under the four artificial aging conditions, respectively. There was an observed increase in the films free surface energy and a significant degradation in the mechanical properties with aging time. This can be correlated with the film material structural changes. The natural aging of the film in North Africa is almost equivalent to artificial aging at 40°C. The concurrent effect of temperature and UV–A radiations induced polymer chains scission leading to faster degradation in the film material and consequently a reduction in its durability and service lifetime. The results show also that the measured parameters are directly related to the limit of use criterion for evaluating the lifespan of agricultural greenhouse LDPE covers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Investigation on thermally‐induced conformation transition of soy protein film with variable‐temperature FTIR spectroscopy
Authors: Tian Kun , Shao Zhengzhong , Chen Xin 
Published: November 2011

AbstractSoy proteins are important and versatile foodstuffs, and are potentially very valuable natural materials as replacements for synthetic polymers if mechanical properties and water sensitivity could be improved by changing its conformational structure during processing. As part of such investigations, the thermally‐induced conformation transitions of soy protein films were studied in detail with variable‐temperature FTIR spectroscopy and two‐dimensional correlation analysis. The results show that during the heating process, relatively mobile random coil segments in the soy protein chains reconfigure to a relatively stable β‐turn conformation as part of major structural changes. The observations in heated‐cooled‐heated experiments reveal that a fraction of such a conformation transition is reversible. As part of this analysis, we identify for the first time that the peak at 1500 cm−1 in the FTIR spectra can be assigned to the characteristic absorption of β‐turn, which is also associated with the peak at 1700 cm−1 and is seen in other important structural proteins such as silk fibroin. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Imparting conductivity and chromic behavior on polyester fibers by means of poly(3‐methylthiophene) nanocoating
Authors: Dashti Mahdieh , Mokhtari Javad , Nouri Mahdi , Shirini Farhad 
Published: November 2011

AbstractPoly(3‐methylthiophene) (P3MT)‐coated polyester fabric is a conductive textile with specific electrical and optical properties; for instance, color change under external stimulus (chromic behavior) was successfully prepared by chemical polymerization with continuous, speed stirring technique. To investigate the striking effect of some variable conditions of polymerization process, the effect of reaction time, temperature, and oxidant concentration on conductivity of the P3MT‐coated fabric was studied. Scanning electron microscopy confirmed that the surface of fabric has entirely been coated with P3MT particles. The further characterizations were investigated using Fourier transform infrared spectroscopy to provide evidence of forming particles onto the fabric, UV–vis absorption spectroscopy, electrical surface resistivity, and pressure dependence visible reflectance spectrophotometer measurements and X‐ray diffraction analysis. The blue shift in wavelength of maximum absorption of about 95 nm to a longer wavelength from that observed in the reflectance spectra of coated polyester fabric; under high‐pressure P3MT‐coated polyester fabric demonstrated piezochromism. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Miscibility of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) with high molecular weight poly(lactic acid) blends determined by thermal analysis
Authors: Modi Sunny , Koelling Kurt , Vodovotz Yael 
Published: November 2011

AbstractAn important strategy used in the polymer industry in recent years is blending two bio‐based polymers to attain desirable properties similar to traditional thermoplastics, thus increasing the application potential for bio‐based and bio‐degradable polymers. Miscibility of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) with poly(L‐lactic acid) (PLA) were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Three different grades of commercially available PLAs and one type of PHBV were blended in different ratios of 50/50, 60/40, 70/30, and 80/20 (PHBV/PLA) using a micro‐compounder at 175°C. The DSC and TGA analysis showed the blends were immiscible due to different stereo configuration of PLA polymer and two distinct melting temperatures. However, some compatibility between PHBV and PLA polymers was observed due to decreases in PLA's glass transition temperatures. Additionally, the blends do not show clear separation by SEM analysis, as observed in the thermal analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Study on the enzymatic degradation of aliphatic polyester–PBS and its copolymers
Authors: Ding Mingliang , Zhang Min , Yang Jinming , Qiu Jian‐Hui 
Published: November 2011

AbstractThe catalytic degradation of prepared matrix poly(butylene succinate) (PBS) and its copolymers by immobilized lipase is carried out in the mixed organic solvent containing a small amount of water. The degradation products were studied with various characterizations techniques, including gel permeation chromatography (GPC), time of flight mass spectrum (TOF‐MS), nuclear magnetic resonance (NMR), and Fourier transform‐infrared spectroscopy (FT‐IR). The results showed that under atmospheric pressure, 60°C, after 24 h catalytic degradation of PBS and its copolymers by immobilized lipase, the yellow oil‐like degradation products can be obtained. The lipase has catalytic activity on various copolymers. At the first time, the monomer of BDO was found in the degradation products and the molecular weight of product with aromatic smell is below 1000. The products consisted of cyclic oligomer, linear oligomer and monomers, and cyclic oligomer is at least dimmer. The minimum and maximum degradation yields correspond to PBS (40%) and P(BS‐co‐CL‐co‐CHDM) (54%). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Conjugation to octa‐arginine via disulfide bonds confers solubility to denatured proteins in physiological solution and enables efficient cell internalization
Authors: Kuwada Eri , Tadaki Toshimasa , Kambara Kaori , Egawa Kohji , Noguchi Katsuo 
Published: November 2011

AbstractSome protein transduction methods have already been developed for regenerative medicine application. These methods can be applied to soluble proteins but not to insoluble proteins, such as those that originate from inclusion bodies, for example, Escherichia coli. We have developed a method that allows the in vitro solubilization of denatured proteins without refolding and their efficient cellular internalization through conjugation to the peptide, octa‐arginine (R8), via disulfide bonds with cysteine residues. Ovalbumin (OVA), denatured in urea solution containing dithiothreitol, was used as a model protein. The R8 peptide was conjugated with OVA in urea solution. Denatured OVA was recovered in the insoluble fraction after dialysis against phosphate‐buffered saline. However, almost all the R8‐conjugated OVA was recovered in the soluble fraction and used for translocation experiments in HeLa, Chinese hamster ovary‐K1, Cos‐7, and matured dendritic cells, where efficient internalization of the protein conjugate was observed. Furthermore, we formulated R8‐conjugated β‐galactosidase and R8‐conjugated luciferase using a similar procedure, and investigated how the conjugated proteins are processed after cell internalization. We also observed that only a small fraction of these proteins refolded and almost all underwent intracellular degradation. These results suggest that this method is suitable for the transduction of antigen‐presenting cells and will benefit research and innovation in vaccine design and discovery.
Relaxation‐expansion model for self‐driven retinal morphogenesis
Authors: Eiraku Mototsugu , Adachi Taiji , Sasai Yoshiki 
Published: November 2011

AbstractThe generation of complex organ structures such as the eye requires the intricate orchestration of multiple cellular interactions. In this paper, early retinal development is discussed with respect to the structure formation of the optic cup. Although recent studies have elucidated molecular mechanisms of retinal differentiation, little is known about how the unique shape of the optic cup is determined. A recent report has demonstrated that optic‐cup morphogenesis spontaneously occurs in three‐dimensional stem‐cell culture without external forces, indicating a latent intrinsic order to generate the structure. Based on this self‐organizing phenomenon, we introduce the “relaxation‐expansion” model to mechanically interpret the tissue dynamics that enable the spontaneous invagination of the neural retina. This model involves three consecutive local rules (relaxation, apical constriction, and expansion), and its computer simulation recapitulates the optic‐cup morphogenesis in silico.
Crystal Structures of Ziegler–Natta Catalyst Supports
Authors: Malizia Federica , Fait Anna , Cruciani Giuseppe 
Published: November 2011

AbstractThe crystal structures of three MgCl2⋅n EtOH complexes with n=1.5, 2.8, and 3.3 have been fully determined. Such complexes are the fundamental precursors for Ziegler–Natta polymerization catalysts used to produce polyolefins on a multimillion‐ton scale worldwide. The ab initio structure solution showed that the structure of MgCl2⋅n EtOH complexes with n=1.5 and 2.8 are based on ribbons of metal‐centered octahedra, whereas for n=3.3 this chainlike arrangement breaks into a threadlike structure of isolated octahedra linked by hydrogen bonds. A clear correlation between catalyst performance and the crystal structure of precursors has been found, and reveals the fundamental role of the latter in determining catalyst properties. The direct knowledge of building blocks in the precursor structures will help to develop more accurate models for activated catalysts. These models will not require the arbitrary and oversimplified assumption of locating the catalyst active sites on selected cut surfaces of the α‐MgCl2 crystal lattice.
The Multivalent Effect in Glycosidase Inhibition: Probing the Influence of Architectural Parameters with Cyclodextrin‐based Iminosugar Click Clusters
Authors: Decroocq Camille , Rodríguez‐Lucena David , Russo Virginie , Mena Barragán Teresa , Ortiz Mellet Carmen , Compain Philippe 
Published: November 2011

AbstractIn contrast to most lectins, glycosidases may appear to be unpromising targets for multivalent binding because they display only a single active site. To explore the potential of multivalency on glycosidase inhibition, unprecedented cyclodextrin‐based iminosugar conjugates have been designed and prepared. The synthesis was performed by way of CuI‐catalyzed azide–alkyne cycloaddition reaction under microwave activation between propargylated multivalent β‐cyclodextrins and an azide‐armedN‐alkyl 1‐deoxynojirimycin derivative. Evaluation with a panel of glycosidases of this new class of glycomimetic clusters revealed the strongest affinity enhancement observed to date for a multivalent glycosidase inhibitor, with binding enhancement up to four orders of magnitude over the corresponding monovalent ligand for α‐mannosidase. These results demonstrate that the multivalency concept extends beyond carbohydrate–lectin recognition processes to glycomimetic–enzyme inhibition.