bluuebunny/crossref_metadata_2025_split huggingface dataset:
The association between chorionic villus sampling and preeclampsia
Authors: Grobman William A. , Auger Melissa , Shulman Lee P. , Elias Sherman 
Published: May 2009

AbstractObjectiveTo determine whether an association exists between prenatal diagnostic procedures and preeclampsia.MethodsAll women who underwent invasive prenatal diagnosis and were not at high risk for preeclampsia were identified during a 15‐month period and matched by age with women who had not had invasive prenatal diagnosis. The association between prenatal diagnosis [amniocentesis and chorionic villus sampling (CVS)] and the development of preeclampsia was assessed in univariable and multivariable analyses.ResultsSix‐hundred and fifty‐three women who underwent prenatal diagnosis (501 by amniocentesis and 152 by CVS) were matched by age with 653 women who did not undergo the test. In multivariable analysis, the factors that remained significantly associated with preeclampsia were (1) maternal age less than 25 years (OR 7.4, 95% CI 23.3–23.6); (2) nulliparity (OR 2.7, 95% CI 1.1–6.9); and (3) having had a CVS as a nulliparous woman (OR 4.2, 95% CI 1.4–12.6).ConclusionThese data suggest that CVS is associated with the subsequent development of preeclampsia in nulliparous women; this relationship should be confirmed in further studies. Copyright © 2009 John Wiley & Sons, Ltd.
How the blind cope with problems of medicine utilization: a study in Bangkok, Thailand
Authors: Riewpaiboon Arthorn 
Published: May 2009

AbstractPurposeThis project is aimed at studying medicine utilization among blind people in Bangkok, Thailand.MethodsThe study was designed as a cross‐sectional descriptive research. The study group comprised visually impaired persons, aged at least 18 years, and living in Bangkok. Data were collected via face‐to‐face interviews in 2007.ResultsThe study included 86 people. The majority of the subjects were 31–50 years old (65%) and male (61%). During the two weeks before the interview, the most frequently used medicines were anti‐inflammatory drugs and muscle relaxants (26%), followed by antipyretics. Most of the subjects received their medicines from drugstores. During the three months before the interview, 75% of the subjects received pharmacy information through various channels. The major source was drugstores, followed by radio. With regard to procurement of medication, 79% of the subjects went to hospitals and 57% acquired the medicines by themselves. Approximately 20% of the subjects received medicines with touchable‐differentiated packaging. For purposes of self‐medication, the subjects were able to differentiate types, doses, and durations of drug use based on memory. Regarding pharmaceutical services, 81% of the subjects required special services intended for the disabled, as well as further explanation of the medicine's use, including drug labeling.ConclusionsBased on the study results, most of the blind did not receive assistance regarding medicine use. Their use of medicine was based on memory, and they were in need of improved pharmaceutical services. Copyright © 2009 John Wiley & Sons, Ltd.
Numerical simulation and experimental validation of mixing performance of kneading discs in a twin screw extruder
Authors: Zhang Xian‐Ming , Feng Lian‐Fang , Chen Wen‐Xing , Hu Guo‐Hua 
Published: May 2009

AbstractThis work aims at simulation by particle tracking the local residence time distributions (RTDs) of a co‐rotating twin‐screw extruder using computational fluid dynamics. Simulated results follow reasonably well the trend of experimental results obtained by an in‐line measuring instrument for different screw configurations and feed rates. To analyze the distributive mixing performance and overall efficiency of different types of kneading discs (KDs), mixing parameters such as area stretch ratio, instantaneous efficiency, and time‐average efficiency are calculated. Among KDs with stagger angles 45°, 60°, and 90°, the 90/10/64 with disc gaps is most efficient in terms of distributive mixing. The effects of the disc width and disc gap on the local RTD and distributive mixing are also discussed. This provides a numerical tool for assessing point‐by‐point information on the local RTD, flow, and mixing along the screw extruder. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Coating weight reduction by a carrier layer for tensioned‐web slot coating
Authors: Tsai Han‐Chih , Chang Hsien‐Ming , Liu Ta‐Jo 
Published: May 2009

AbstractThe feasibility of using a dilute bottom carrier layer to reduce the thickness of a viscous top layer for tensioned‐web slot coating was examined experimentally. Aqueous poly(vinyl) alcohol solutions were prepared for both the carrier and the top layers. The solutions were coated on poly(ethylene terephthalate) films for observation. The thickness ratio of the two layers has to be in a certain range for stable coating, otherwise different types of coating defects would appear. The effects of viscosity, wrapping angle, surface tension, and web tension were studied. It was found that the viscosity ratio of the top layer to the carrier layer is the most critical factor; a large ratio is more helpful in reducing the thickness of the top layer. Increasing the wrapping angle, web tension, and surface tension of the top layer can also decrease the coating thickness of the top layer. The drying load is reduced substantially owing to the significant reduction of the top layer thickness. It was estimated that 50–90% of the energy required for drying could be saved by introducing a carrier layer in this study. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Investigation on the multiwalled carbon nanotubes reinforced polyamide 6/polypropylene composites
Authors: Zhang Lingyan , Wan Chaoying , Zhang Yong 
Published: May 2009

AbstractMultiwalled carbon nanotubes (MWNTs) reinforced polyamide 6/polypropylene (PA6/PP = 70/30) composites were prepared by melt compounding. Maleated polypropylene (MPP) was used as a compatibilizer for the composites. The morphology, mechanical properties, thermal stability, rheological properties and crystallization behavior of the composites were investigated. It was found that the addition of MWNTs to PA6/PP blend resulted in decrease in the size of the dispersed particles. Most of MWNTs were selectively dispersed in the PA6 phase and a small amount of MWNTs were located in the interphase between PA6 matrix and PP phase as characterized by scanning electric microscopy. The strength and stiffness of the PA6/PP blend were greatly improved by the addition of MWNTs. The MPP and MWNTs had a synergistic effect on the improvement ofthe thermal stability. In addition, the complex viscosity, storage modulus and loss modulus of the composites increased with the addition of MWNTs or MPP. MWNTs could induce the formation of α crystalline form of PA6. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Chitin and chitosan: Transformations due to the electrospinning process
Authors: Schiffman Jessica D. , Stulga Laura A. , Schauer Caroline L. 
Published: May 2009

AbstractElectrospinning is a complex process that requires numerous interacting physical instabilities. Assuming that a chosen polymer and solvent system can be spun, the chosen polymer exists in various states, which have variable crystallinities starting with the highest degree of crystallinity (when in bulk form) and ultimately being transformed into a non‐woven mat. In an effort to better understand the effects that the electrospinning process has on the biopolymers chitin [practical grade (PG)] and chitosan [PG and medium molecular weight (MMW)], including post‐production neutralization and cross‐linking steps, field emission scanning electron microscopy (FESEM) and solubility studies were performed. An evaluation of diffraction peaks of the bulk, solution, and fibrous forms of chitin and chitosan were evaluated by X‐ray diffraction (XRD) and determined that the formation of chitosan chains is influenced by the addition of solvent and cross‐linking agent. This study is of importance since the crystallinity of chitin and chitosan directly relate to the ability of the biopolymers to chelate metals, and the chemical stability of non‐woven mats aid in the creation of functional filtration membranes. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Influence of processing window and weight ratio on the morphology of the extruded and drawn PET/PP blends
Authors: Li Wenjing , Schlarb Alois K. , Evstatiev Michael 
Published: May 2009

AbstractTo obtain polyethylene terephthalate (PET)/polypropylene (PP) microfibrillar composite (MFC) with good mechanical properties, a high content of PET fibrils in the drawn strand (i.e. PET droplets in the extrudate) is preferred. However, a phase inversion (from PP matrix to PET matrix) takes place when the concentration of the PET reaches 40 wt% at the screw speed of 40 rpm (rounds per minute). This “PP domains in PET matrix” phase structure is the undesired phase structure for preparing MFC. However, the desired phase structure of “PET droplets in PP matrix” can be regained by adopting a low screw speed (20 rpm) during extrusion of the PET/PP (40/60); if a higher screw speed is adopted (80 rpm), then a suitable amount of PP grafted maleic anhydride (PP‐g‐MA) should be incorporated. The PET/PP blends which demonstrate the desired “PET droplets in PP matrix” phase structure were stretched into strands, and PET/PP MFC was prepared. The MFC with high content of PET microfibrils as the reinforcement exhibits superior tensile properties than the neat PP. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
The use of crack layer theory to predict the lifetime of the fatigue crack growth of high density polyethylene
Authors: Choi Byoung‐Ho , Balika Werner , Chudnovsky Alexander , Pinter Gerald , Lang Reinhold W. 
Published: May 2009

AbstractIn the case of high density polyethylene (HDPE), the fatigue crack propagates in a discontinuous manner, which can be observed by distinct striations. In this article, fatigue crack growth (FCG) experiments were conducted on two grades of HDPE pipe with compact‐tension (CT) and cracked round bar (CRB) specimens. The effects of the stress ratio (R‐ratio) which is defined as the ratio of minimum stress and maximum stress of fatigue loadings and the frequency on FCG behavior were experimentally studied. Although FCG rates showed a great dependence on the R‐ratio in terms of the range of the stress‐intensity factor, the effect of the frequency may be considered to be significant in the low crack growth region. In addition, these experimental data were employed for predicting the lifetime on the basis of the crack layer (CL) theory. Only a few steps of FCG are needed to determine all necessary parameters for CL theory, and the FCG behavior can be reconstructed based on a computer program that has been developed for the application of CL theory. The predictions from this program accord with experimental data. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Genetic and plasma variation of insulin‐like growth factor binding proteins in relation to prostate cancer incidence and survival
Authors: Johansson Mattias , McKay James D. , Rinaldi Sabina , Wiklund Fredrik , Adami Hans‐Olov , Grönberg Henrik , Kaaks Rudolf , Stattin Pär 
Published: May 2009

AbstractBACKGROUNDBinding proteins regulate bioavailability of insulin‐like growth factor‐I (IGF‐I) in the circulation and affect apoptosis of tumor cells in the prostate. We analyzed genetic variation within genes coding for IGF binding proteins in relation to prostate cancer incidence and survival. We also investigated if circulating IGFBP3 affects prostate cancer‐specific survival.MATERIALS AND METHODSEleven haplotype tagging SNPs and two single SNPs in the IGFBP1, IGFBP3, and IGFALS genes were genotyped within the CAncer Prostate in Sweden (CAPS) study including 2,774 cases and 1,736 controls. Plasma samples for analyses of total‐ and intact IGFBP3 levels were available for 1,521 cases and 909 controls. Complete follow‐up of vital status was achieved by linkage to the Swedish Cause of Death Register.RESULTSWe found no clear association between the genetic variants and prostate cancer incidence or survival. The rare allele of the IGFBP3 SNP rs2854744 was associated with elevated plasma levels of total IGFBP3 (Ptrend = 9 × 10−8), but not intact IGFBP3 (Ptrend = 0.16). Elevated levels of total‐ (Ptrend = 0.03) and intact IGFBP3 (Ptrend = 6 × 10−14) were associated with increased risk of prostate cancer specific death. Treatment and tumor characteristics accounted for the association with total IGFBP3, whereas the association with intact IGFBP3 was attenuated, but still statistically significant in adjusted analysis (Ptrend‐adjusted = 0.0004). Elevated intact IGFBP3 was also significantly associated with increased risk of prostate cancer‐specific death among patients who were chemically or surgically castrated (Ptrend‐adjusted = 0.0003), and among patients who had not been treated (Ptrend‐adjusted = 0.02).CONCLUSIONSCirculating levels of intact IGFBP3 measured after diagnosis is associated with increased risk of prostate cancer‐specific death. Prostate 69:1281–1291, 2009. © 2009 Wiley‐Liss, Inc.
Cell selectivity and mechanism of action of short antimicrobial peptides designed from the cell‐penetrating peptide Pep‐1
Authors: Zhu Wan Long , Hahm Kyung‐Soo , Shin Song Yub 
Published: May 2009

AbstractPep‐1‐K (PK) is a good cell‐selective antimicrobial peptide designed from cell‐penetrating peptide Pep‐1. To develop novel short antimicrobial peptides with higher cell selectivity and shorter length compared with PK, several PK analogs were designed by the deletion, addition and/or substitution of amino acids. Among these analogs, PK‐12‐KKP (KKPWWKPWWPKWKK) showing the sequence and structure homology with a Trp/Pro‐rich natural antimicrobial peptide, indolicidin (IN), displayed a 20‐fold higher cell selectivity as compared to IN. Circular dichroism analysis revealed that PK‐12‐KKP adopts a folded structure combined with some portions of unordered structure. PK‐12‐KKP selectively binds to negatively charged bacterial membrane–mimetic vesicles, and its high phospholipid selectivity corresponds well with its high cell selectivity. Moreover, it showed very weak potential in depolarization of the cytoplasmic membrane of Staphylococcus aureus at 8 µM (4× minimal inhibitory concentration) and dye leakage from negatively charged liposomes. These results suggest that the ultimate target of our designed PK‐12‐KKP maybe the intracellular components (e.g. protein, DNA or RNA) rather than the cytoplasmic membranes. Collectively, our designed short Trp/Pro‐rich peptide, PK‐12‐KKP, appears to be an excellent candidate for future development as a novel antimicrobial agent. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
QSAR Studies of HEPT Derivatives Using Support Vector Machines
Authors: Darnag Rachid , Schmitzer Andreea , Belmiloud Yamina , Villemin Didier , Jarid Abdellah , Chait Abderrahman , Seyagh Maria , Cherqaoui Driss 
Published: May 2009

AbstractHuman Immunodeficiency Virus type 1 reverse transcriptase is an important target for chemotherapeutic agents against the AIDS disease. 1‐[2‐Hydroxyethoxy‐methyl]‐6‐(phenylthio) thymine] derivatives are potent nonnucleoside reverse transcriptase inhibitors. In the present work, quantitative structure‐activity relationship analysis for a set of 79 HEPT derivatives has been investigated by means of support vector machines. The relationships between structure and activity were examined quantitatively using descriptors encoding the steric, hydrophobic, electronic and structural features of 1‐[2‐hydroxyethoxy‐methyl]‐6‐(phenylthio) thymine] derivatives. The performance and predictive capability of support vector machines method are investigated and compared with other methods such as artificial neural network and multiple linear regression methods. The obtained results indicate that the support vector machines model with the kernel radial basis function can be employed as a forceful tool for quantitative structure‐activity relationship studies. The contribution of each descriptor to the structure‐activity relationships was evaluated.
Quantitative Structure Activity Relationship (QSAR) Approach to Multiple Drug Resistance (MDR) Modulators Based on Combined Hybrid System
Authors: Wu Jianhua , Li Xin , Cheng Weidong , Xie Qinjian , Liu Yinqian , Zhao Chunyan 
Published: May 2009

AbstractThe aim of this paper was to build hybrid QSAR models for predicting multiple drug resistance (MDR) modulators modulating activity of 70 compounds based on single multiple linear regression (MLR) models and support vector machine (SVM) models. All models were validated using more strict criteria to make sure that the results are reliable and robust. For the best hybrid model, it gave the best performance, with corresponding correlation coefficientsR2of 0.85, 0.81, and 0.84 for training, test, and whole data set, respectively. The hybrid method was proved to be a very promising tool in the prediction of MDR‐modulating activity. Additionally, the application of strict validation criteria permits the high quality of the hybrid model. Thus, these in silico methods can be applied to predict this property in the early stage of drug development and some of them will be important tools to select new drug candidates.
Delayed luminescence from collagen as arising from soliton and small polaron states
Authors: Scordino Agata , Grasso Rosaria , Gulino Marisa , Lanzanò Luca , Musumeci Francesco , Privitera Giuseppe , Tedesco Maurizio , Triglia Antonio , Brizhik Larissa 
Published: May 2009

AbstractWith the aim to give more hints to a theoretical model that describes the phenomenon of delayed luminescence (DL) from biological systems as due to the collective electron states that are excited in macromolecular structures by external illumination, a spectral characterization of DL from bovine Achilles' tendons sample at different hydration states has been performed. Tendons are mainly composed by Type I collagen macromolecules which form a one‐dimensional system with the long‐range order and capability of self‐organization, so favoring the existence of such collective excitations. Modeling the crystal structure of collagen as a one‐dimensional chain whose unit cell is formed by a tripeptide, the ground state of the corresponding Hamitonian has been evaluated by a variational approach. The change in DL from bovine Achilles' tendons, depending on the water content of the sample, has been correlated to the change in the ground state of such one‐dimensional lattice from a soliton state, for samples close to native, to a small polaron state, for samples that are much more dry. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
The model of fungal population dynamics affected by nystatin
Authors: Voychuk Sergei I. , Gromozova Elena N. , Sadovskiy Mikhail G. 
Published: May 2009

AbstractFungal diseases are acute problems of the up‐to‐day medicine. Significant increase of resistance of microorganisms to the medically used antibiotics and a lack of new effective drugs follows in a growth of dosage of existing chemicals to solve the problem. Quite often such approach results in side effects on humans. Detailed study of fungi‐antibiotic dynamics can identify new mechanisms and bring new ideas to overcome the microbial resistance with a lower dosage of antibiotics. In this study, the dynamics of the microbial population under antibiotic treatment was investigated. The effects of nystatin on the population of Saccharomyces cerevisiae yeasts were used as a model system. Nystatin effects were investigated both in liquid and solid media by viability tests. Dependence of nystatin action on osmotic gradient was evaluated in NaCl solutions. Influences of glucose and yeast extract were additionally analyzed. A “stepwise” pattern of the cell death caused by nystatin was the most intriguing. This pattern manifested in periodical changes of the stages of cell death against stages of resistance to the antibiotic. The mathematical model was proposed to describe cell‐antibiotic interactions and nystatin viability effects in the liquid medium. The model implies that antibiotic ability to cause a cells death is significantly affected by the intracellular compounds, which came out of cells after their osmotic barriers were damaged © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
ProtNA‐ASA: Protein‐nucleic acid structural database with information on accessible surface area
Authors: Tkachenko M. Y. , Boryskina O. P. , Shestopalova A. V. , Tolstorukov M. Y. 
Published: May 2009

AbstractThe article describes a new database (ProtNA‐ASA), which combines the data on conformational parameters of nucleic acids and calculations of the accessible surface area (ASA) of nucleic acid atoms in protein‐DNA/RNA complexes. As for October 2008, the database contains 214 DNA‐protein and 28 RNA‐protein non‐homologous complexes. The database provides structural parameters that describe local geometry of base pairs and base‐pair steps as well as backbone torsion angles. Additionally, total ASA of DNA/RNA atoms and the accessible area of atoms in the minor and major grooves are calculated. ProtNA‐ASA database facilitates studying the relationship between the DNA/RNA conformation and availability of atoms for contact with proteins either in major or in minor groove for different nucleotides. Such an analysis is important for understanding the principles of molecular recognition including indirect sequence readout. The database is publicly available for use at http://www.protna.bio‐page.org. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
On the interaction of rubidium and cesium mono‐, strontium and barium bi‐cations with DNA and RNA bases. A theoretical study
Authors: Marino Tiziana , Mazzuca Donatella , Russo Nino , Toscano Marirosa , Grand Andre 
Published: May 2009

AbstractWe performed a density functional investigation of the interactions of the two alkaline metal ions Rb(I) and Cs(I) and two alkaline earth metal ions Ba(II) and Sr(II), with DNA and RNA nucleobases. All the possible molecular complexes, originated from the attack of these cations to the different binding sites present on some selected low‐lying nucleobase tautomers, were considered to determine their relative stabilities and the preferred metal coordination geometries and sites. Absolute metal ions affinities were computed taking into account the most stable metal complex of each base with the aim to rationalize the trend of the obtained values within of and between the first and second periodic table main groups. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Nonlinear dynamics of DNA: Velocity of the kinks activated in homogeneous polynucleotide chains
Authors: Yakushevich L. V. 
Published: May 2009

AbstractIdeas of Alexandr Sergeevich Davydov applied to DNA have led to new important results on the nonlinear dynamics of the molecule, and at the same time they led to new interesting problems that have not been solved yet. One of the problems concerned the velocity of the kinks propagating in DNA polynucleotide chains. In this article, we present the results of calculations of the kink velocity made for particular case of synthetic homogeneous polynucleotide chains. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010