bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of lead content in medicinal plants by pre‐concentration flow injection analysis–flame atomic absorption spectrometry
Authors: Campos Marina M. A. , Tonuci Henry , Silva Silvana M. , de S. Altoé Bruna , de Carvalho Dermeval , Kronka Eloisa A. M. , Pereira Ana M. S. , Bertoni Bianca W. , de C. França Suzelei , Miranda Carlos E. S. 
Published: July 2009

AbstractIntroduction – Although medicinal plants are widely used throughout the world, few studies have been carried out concerning the levels of heavy metal contaminants present. Such metals are highly toxic to living organisms even in low concentrations owing to their cumulative effect. The present paper describes the the development of a pre‐concentration flow injection analysis‐flame atomic absorption spectrometric system to determine the lead content in medicinal plants at the ppb level.Objective – To develop a pre‐concentration flow injection analysis‐flame atomic absorption spectrometric system to determine the lead content in medicinal plants at the ppb level.Methodology – A pre‐concentration flow system was coupled to a flame atomic absorption spectrometer. The plant samples were analysed after nitroperchloric digestion. The proposed system was optimised by evaluating the following parameters: nature, concentration and volume of the eluent solution, elution flow rate, elution efficiency, pre‐concentration flow rate and pre‐concentration time.Results – The proposed system exhibited good performance with high precision and repeatability (RSD ≤ 2.36%), excellent linearity (r = 0.9999), low sample consumption (10.5 mL per determination) and an analytical throughput of 55 samples/h. Lead concentrations ranged from 3.37 ± 0.25 to 7.03 ± 0.51 μg/g in dry material. This concentration interval is greater than that previously published in the literature.Conclusion – The inclusion of a pre‐concentration column in the flow manifold improved the sensitivity of the spectrometer. Thus, it was possible to determine the analyte at the ng/mL level in sample solutions of medicinal plants. This is a very important accomplishment, especially when the cumulative effect of heavy metals in living organisms is considered. Copyright © 2009 John Wiley & Sons, Ltd.
A rapid and sensitive prenatal diagnosis of familial amyloidotic polyneuropathy ATTR Val30Met by mass spectrometry
Authors: Yamashita Taro , Ando Yukio , Ueda Mitsuharu , Okamoto Sadahisa , Misumi Yohei , Nakamura Masaaki , Takashi Ohba , Uchino Makoto 
Published: July 2009

AbstractObjectiveTo make a prenatal diagnosis of familial amyloidotic polyneuropathy (FAP) by mass spectrometry with the amniotic fluid.MethodsAmniotic‐fluid samples of three non‐FAP pregnant women and six amniotic‐fluid samples of fetal mice whose mother was a heterozygotic FAP amyloidgenic transthyretin (ATTR) Val30Met gene carrier were collected. Electro spray ionization mass spectrometry (ESI‐MS) was employed to identify and quantitatively measure the molecular weight of the human transthyretin (TTR) in the amniotic fluid.ResultsTTR was detected in the amniotic fluid of all the human samples. In four of the six fetuses of the transgenic mice, human TTR Val30Met was detected. The other two samples showed only mouse TTR without human TTR Val30Met. DNA analysis revealed that the four fetuses were TTR Val30Met positive, but two were negative. The data from the DNA analysis and ESI‐MS showed a 100% concordance.ConclusionMass spectrometry analysis of the amniotic fluid might be a useful tool to make a prenatal diagnosis of FAP ATTR Val30Met. Copyright © 2009 John Wiley & Sons, Ltd.
Steroid sulfatase deficiency and contiguous gene deletion syndrome amongst pregnant patients with low serum unconjugated estriols
Authors: Langlois Sylvie , Armstrong Linlea , Gall Kim , Hulait Gurdip , Livingston Janet , Nelson Tanya , Power Patricia , Pugash Denise , Siciliano Dawn , Steinraths Michelle , Mattman André 
Published: July 2009

AbstractObjectiveTo ascertain all prenatally diagnosed cases of Steroid Sulfatase (STS) deficiency in British Columbia between August 2002 and July 2007 to determine the incidence of this condition, the clinical and laboratory findings, and the risk of a contiguous gene deletion syndrome.MethodsWe reviewed the medical records of these patients to obtain detailed information about the maternal serum screening results, family history, investigations performed, and outcome of the pregnancy.ResultsThirty pregnant patients were found to have a male fetus/infant with STS deficiency, giving a minimal estimated incidence of this condition of approximately 1 in 1513 males. In twenty nine cases, this condition was isolated. One patient was found to have a contiguous gene deletion syndrome. In cases of sporadic STS deficiency diagnosed prenatally, the frequency of contiguous gene deletion syndrome in this study was 1 out of 12 (8.3%).ConclusionThe clinical, cytogenetic and molecular data on this series of prenatally diagnosed cases of STS deficiency indicates that this is a common condition and in cases with no family history, the risk of contiguous gene deletion syndrome is significant, and warrants additional molecular genetic investigations of the mother and/or fetus. Copyright © 2009 John Wiley & Sons, Ltd.
Design and electrical conductivity of poly(acrylic acid‐g‐gelatin)/graphite conducting gel
Authors: Tang Qunwei , Sun Xiaoming , Wu Jihuai , Li Qinghua , Lin Jianming 
Published: July 2009

AbstractA novel poly(acrylic acid‐g‐gelatin)/graphite composite is synthesized by aqueous solution polymerization. Based on the electrical conductivity of graphite nanoplatelets and the absorbency of poly(acrylic acid‐g‐gelatin)/graphite, a novel conducting gel with a conductivity of 3.18 mS cm−1 is prepared. The effects of synthesis parameters on the electrical conductivity of the gels are investigated in detail. An appended network structure model of the poly(acrylic acid‐g‐gelatin)/graphite conducting gel is proposed. The conducting gel presents a high mechanical strength in cyclohexane, which is important for the gel applications. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
On the physical behavior of isotactic polypropylene fibers extruded at different draw‐down ratios. I. Optical properties and cold‐drawing
Authors: El‐Dessouky Hassan M. , Mahmoudi Mohammad R. , Lawrence Carl A. , Yassien Khaled M. , Sokkar Taha Z.N. , Hamza Ahmed A. 
Published: July 2009

AbstractAs spun polypropylene fibers (iPP) with different draw‐down ratios (DDR) were produced at increasing take‐up speeds ranging from 200 m/min to 1000 min. Two interferometric techniques (Pluta and Interphako microscopes) were used to investigate the refractive indices and birefringence of the spun fibers. The use of the Interphako microscope enabled all the fiber diameters to be studied and avoid image overlap (Sokkar et al., Opt. Lasers Eng., 45, 431 (2007)). Previously reported software (Sokkar et al., Opt. Lasers Eng., 45, 431 (2007), Hamza et al., J. Appl. Polym. Sci., 77, 3099 (2000)) was used to determine the refractive index profiles for PP fibers at different DDR. An optothermomechanical (OTM) (Hamza et al., J. Appl. Polym. Sci., 95, 647 (2005)). device attached to the Pluta microscope was used to examine the drawability of the melt‐spun iPP fibers by cold‐drawing. The work is concerned with the importance of the difference between physical effects of DDR and DR. The influence of DDR on the relation between optical properties and solid state draw ratio (DR) was determined. The fibers spun at low DDR give high‐maximum draw ratio (DRmax) and higher birefringence (Δn) than those of higher DDR. Total attenuation ratio (TAR) of the melt‐spun iPP fibers was defined and calculated. The minimum (theoretical) birefringence (Δnmin) and maximum (measurable) birefringence (Δnmax) of iPP fibers were determined. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Cure kinetics, phase behaviors, and fracture properties of bismaleimide resin toughened by poly(phthalazinone ether ketone)
Authors: Han Yongjin , Liao Gongxiong , Xu Yajuan , Yu Guipeng , Jian Xigao 
Published: July 2009

AbstractPoly(phthalazinone ether ketone)s (PPEK) were used to toughen bismaleimide (BMI) resin composed of 4,4′‐bismaleimidodiphenyl methane (BMDM) and O,O′‐diallyl bisphenyl A (DABPA). Dynamic differential scanning calorimetry (DSC) of the blends was carried out for kinetic analysis of the curing reaction. The reaction activation energy indicated that the reaction mechanism remained the same even after the incorporation of PPEK. The reaction‐induced phase separation process in BMI/PPEK blends was investigated by optical microscopy (OM). The primary phase structure of the blends was fixed at the early stage of phase separation, and a secondary phase separation was observed as a result of the high viscosity of the blends. Scanning electron microscope (SEM) graphs showed that the morphology of the cured resin changed from a dispersed structure to a phase‐inverted structure with the increase of PPEK content. Compared with the neat resin, the fracture toughness of the modified resin exhibits a moderate increase when PPEK was incorporated. Several toughening mechanisms, such as local plastic deformation, crack deflection, and branches, presumably took part in improving the toughness of BMI/PPEK blends on the basis of the morphology. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Dielectric Multilayer Films Fabricated by Magnetron Sputtering: How Far Can the Iridescence Be Tuned?
Authors: Deparis Olivier , Rassart Marie , Vandenbem Cédric , Welch Victoria , Vigneron Jean‐Pol , Dreesen Laurent , Lucas Stéphane 
Published: July 2009

AbstractPeriodic dielectric multilayer structures can generate interferential colours from optically transparent basic materials. Their iridescence property, i.e. the change of colour with the illumination or viewing angle, is exploited in the industry to produce structurally coloured coatings and paints. Magnetron sputtering is an efficient technique for producing multilayer films owing to its ability to deposit films on large surfaces with excellent uniformity and reproducibility in both the film thickness and composition. Based on a theoretical model of the optical response, we investigated the iridescence tuning range of the technologically important SiO2/TiO2 material system. Radically different iridescent behaviours were predicted theoretically and demonstrated experimentally by selecting appropriate combinations of period and layer thickness ratio.
New Developments and Applications of X‐Ray Capillary Optics
Authors: Bjeoumikhov Aniouar , Bjeoumikhova Semfira , Wedell Reiner 
Published: July 2009

AbstractCapillary optics have found broad research and industrial applications in X‐ray analytics. In the present paper, the use of mono‐ and polycapillary optics for X‐ray beam shaping at synchrotron beamlines and in combination with laboratory sources is described. In particular, a module for in situ XRD in SEMs is considered in detail and corresponding application examples are presented.
Hard X‐Rays for In Situ Strain and Texture Measurements
Authors: Brokmeier Heinz‐Günter 
Published: July 2009

AbstractHard X‐rays having photon energies of higher than 50 keV are characterized by having a high penetration power. These high energy X‐rays are provided by using W‐tubes or at storage rings (synchrotron radiation). Due to the high photon flux and the excellent brilliance of synchrotron radiation, experiments can be carried out quickly. In situ strain experiments can be performed in real time, so that lattice strain evolutions can be investigated in parallel to obtaining conventional stress‐strain curves. Crystallographic texture measurements are time consuming but quick synchrotron measurements at different points of the stress‐strain curve are able to describe the texture evolution during tension or compression, allowing confirmation of texture simulations and yielding material property evolutions during tension or compression experiments.
Crystal structure of the variable domain of the Streptococcus gordonii surface protein SspB
Authors: Forsgren Nina , Lamont Richard J. , Persson Karina 
Published: July 2009

AbstractThe Antigen I/II (AgI/II) family of proteins are cell wall anchored adhesins expressed on the surface of oral streptococci. The AgI/II proteins interact with molecules on other bacteria, on the surface of host cells, and with salivary proteins. Streptococcus gordonii is a commensal bacterium, and one of the primary colonizers that initiate the formation of the oral biofilm. S. gordonii expresses two AgI/II proteins, SspA and SspB that are closely related. One of the domains of SspB, called the variable (V‐) domain, is significantly different from corresponding domains in SspA and all other AgI/II proteins. As a first step to elucidate the differences among these proteins, we have determined the crystal structure of the V‐domain from S. gordonii SspB at 2.3 Å resolution. The domain comprises a β‐supersandwich with a putative binding cleft stabilized by a metal ion. The overall structure of the SspB V‐domain is similar to the previously reported V‐domain of the Streptococcus mutans protein SpaP, despite their low sequence similarity. In spite of the conserved architecture of the binding cleft, the cavity is significantly smaller in SspB, which may provide clues about the difference in ligand specificity. We also verified that the metal in the binding cleft is a calcium ion, in concurrence with previous biological data. It was previously suggested that AgI/II V‐domains are carbohydrate binding. However, we tested that hypothesis by screening the SspB V‐domain for binding to over 400 glycoconjucates and found that the domain does not interact with any of the carbohydrates.
Quantitative specificity‐based display library screening identifies determinants of antibody‐epitope binding specificity
Authors: Hall Sejal S. , Daugherty Patrick S. 
Published: July 2009

AbstractDespite the critical importance of molecular specificity in bimolecular systems, in vitro display technologies have been applied extensively for affinity maturation of peptides and antibodies without explicitly measuring the specificity of the desired interaction. We devised a general strategy to measure, screen, and evolve specificity of protein ligand interactions analogous to widely used affinity maturation strategies. The specificity of binding to target and nontarget antibodies labeled with spectrally distinct fluorophores was measured simultaneously in protein mixtures via multiparameter flow cytometry, thereby enabling screening for high target antibody specificity. Isolated antibody specific ligands exhibited varying specificity, revealing critical amino acid determinants for target recognition and nontarget avoidance in complex mixtures. Molecular specificity in the mixture was further enhanced by quantitative directed evolution, yielding a family of epitopes exhibiting improved specificities equivalent, or superior to, the native peptide antigen to which the antibody was raised. Specificity screening simultaneously favored affinity, yielding ligands with three‐fold improved affinity relative to the parent epitope. Quantitative specificity screening will be useful to screen, evolve, and characterize the specificity of protein and peptide interactions for molecular recognition applications.
Stereoelectronic effects on the transition barrier of polyproline conformational interconversion
Authors: Chiang Yi‐Chun , Lin Yu‐Ju , Horng Jia‐Cherng 
Published: July 2009

AbstractThere has been growing interest in polyproline type II (PPII) helices since PPII helices have been found in folded and unfolded proteins and involved in a variety of biological activities. Polyproline can also form type I helices (PPI) which are very different from PPII conformation and only exist in certain organic solvents. Recent studies have shown that stereoelectronic effects play a critical role in stabilizing a PPI or PPII helix. Here, we have synthesized a series of host–guest peptides with an electron‐withdrawing substituent at the 4R or 4S position of proline and used a kinetic approach to further explore stereoelectronic effects on the transition barrier of the interconversion between PPI and PPII conformations. Time‐dependent circular dichroism measurements revealed that the rates of PPII → PPI conversion were reduced upon incorporating the hydroxyl‐, fluoro‐, and methoxy‐groups at the 4R position while the rates would be increased if these substituents were at the 4S position. We quantified the changes in transition free energy by comparing their rate constants. (4R,2S)‐4‐Fluoroproline and (4S,2S)‐4‐fluoroproline have the largest effect on the transition energy barrier for PPII → PPI conversion. Our results provide important insights into the role of stereoelectronic effects on the PPII → PPI transition state barrier, which has not been reported in past thermodynamic studies.
Safety management is a virtue
Authors: Summers Angela E. 
Published: July 2009

AbstractIt is undeniable that safe operation and process reliability are not only compatible but highly interrelated. Reliable production units rarely have safety incidents, whereas unreliable ones tend to repeatedly experience abnormal operation. To prevent incidents, personnel, procedures, and equipment must be aligned to facilitate rapid identification and response to failures of the control system and protective safeguards. Safe and reliable performance requires minimization of the root causes that lead to abnormal and emergency operation. The challenges to accomplishing this in a timely manner are considerable, but not insurmountable.This article discusses various challenges to sustaining safe operation of process equipment. Each challenge is introduced using a philosophical saying from a Chinese fortune cookie to remind the reader that the barriers against progress are not new but have existed from many years. In most cases, the solutions are also well known and generally require deployment of robust equipment, proven techniques, and competent resources. © 2009 American Institute of Chemical Engineers Process Saf Prog 2009
Gradual degradation of GaAs‐based quantum well lasers, creation of defects, and generation of compressive strain
Authors: Tomm Jens W. , Ziegler Mathias , Oudart Myriam , Nagle Julien , Jiménez Juan 
Published: July 2009

AbstractWe report on the interplay between compressive strains and defects within the active region of 980 nm emitting high‐power diode laser arrays. By analyzing photocurrent data, we show how external mechanical load caused by device packaging results in cumulative defect signatures within their active region. Furthermore, we analyze the reverse situation, where device degradation results in the generation of defect signatures and these defects subsequently act as driving force for the creation of compressive strains within the quantum well active region of the devices. Knowledge about their microscopic nature will be urgently required for creating more robust semiconductor device architectures.
Sensitivity of triple‐crystal X‐ray diffractometers to microdefects in silicon
Authors: Molodkin V. B. , Olikhovskii S. I. , Len E. G. , Kislovskii E. N. , Kladko V. P. , Reshetnyk O. V. , Vladimirova T. P. , Sheludchenko B. V. 
Published: July 2009

AbstractThe dynamical theory, which describes both diffraction profiles and reciprocal space maps measured from imperfect crystals with account for instrumental factors of triple‐crystal diffractometer (TCD), has been developed for adequate quantitative characterization of microdefects. Analytical expressions for coherent and diffuse scattering (DS) intensities measured by TCD in the Bragg diffraction geometry have been derived by using the generalized statistical dynamical theory of X‐ray scattering in real single crystals with randomly distributed defects. The DS intensity distributions from single crystals containing clusters and dislocation loops have been described by explicit analytical expressions. Particularly, these expressions take into account anisotropy of displacement fields around defects with discrete orientations. Characteristics of microdefect structures in silicon single crystals grown by Czochralsky‐ and float‐zone methods have been determined by analyzing the measured TCD profiles and reciprocal space maps. The sensitivities of reciprocal space maps and diffraction profiles to defect characteristics have been compared.
Critical discussion of models proposed to explain photo‐induced anisotropies in chalcogenide glasses
Authors: Fritzsche Hellmut 
Published: July 2009

AbstractDifferent theories explaining the origin and the mechanism of the dynamic part of photo‐induced anisotropies which are observed in a large family of chalcogenide glasses will be discussed and analyzed. It is useful to distinguish two kinds of photo‐induced anisotropies, Type 1 which involves a limited concentration of bistable anisotropic defects or centers and Type 2 which encompasses most of the materials.
Amorphous research in Romania: Past, present and latest results
Authors: Popescu Mihai , Croitoru Nathan 
Published: July 2009

AbstractIn the early days of amorphous research, Romania was deeply involved in the development of the field of amorphous semiconductors within a close collaboration with Boris Kolomiets. The first researches in this field are discussed and further rapid developments up to the present are shown. The latest results in the field of amorphous semiconductors with special emphasis on chalcogenide glasses are presented.
Study on the effect of Jia‐Wei‐Xiao‐Yao‐San decoction on patients with functional dyspepsia
Authors: Qu Yang , Gan Hong Quan , Mei Qi Bing , Liu Li 
Published: July 2009

AbstractThe effect of Jia‐Wei‐Xiao‐Yao‐San (JWXYS) decoction on patients with functional dyspepsia was studied by means of electrogastrography (EGG) and symptoms of dyspepsia were assessed. Twenty patients with functional dyspepsia were selected; before and after internal treatment with JWXYS, the integrated symptoms of the patients were down‐regulated from 18.55 ± 3.24 (before treatment) to 11.65 ± 2.37 (after treatment) (p < 0.01); electrogastrography showed that all the EGG parameters of the patients were outside the normal range. After treatment with JWXYS, all these indices improved before and after dinner. The results showed that the JWXYS decoction could not only improve the symptoms, but also adjust the abnormal gastric motility and gastric myoelectrical activity of patients with functional dyspepsia. Copyright © 2009 John Wiley & Sons, Ltd.
Antifatigue activity of phenylethanoid‐rich extract fromCistanche deserticola
Authors: Cai Run‐Lan , Yang Mei‐Hua , Shi Yue , Chen Jun , Li Yong‐Chao , Qi Yun 
Published: July 2009

AbstractA phenylethanoid‐rich extract (ECD) ofCistanche deserticolaY.C. Ma, a holoparasitic plant and a valuable traditional Chinese medicine, was evaluated for antifatigue activity in ICR mice. ECD (0.25, 0.50, 1.00 g/kg) was administered orally to mice for 3 weeks. The swimming time to exhaustion was longer in the treatment groups (0.50, 1.00 g/kg) than in the control group (p< 0.01). The serum creatine kinase, lactate dehydrogenase and lactic acid levels were decreased significantly in the treatment groups compared with the control group, while the contents of hemoglobin and glucose were increased significantly. In conclusion, ECD appeared to enhance the swimming capacity of mice by decreasing muscle damage, delaying the accumulation of lactic acid and by improving the energy storage. These results provide scientific evidence for the traditional Chinese medical practice ofC. deserticola. Copyright © 2009 John Wiley & Sons, Ltd.