bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association study of brain‐derived neurotrophic factor in adults with a history of childhood onset mood disorder
Authors: Strauss J. , Barr C.L. , George C.J. , King N. , Shaikh S. , Devlin B. , Kovacs M. , Kennedy J.L. 
Published: September 2004

AbstractBrain‐derived neurotrophic factor (BDNF) is a nerve growth factor that has antidepressant‐like effects in animals. BDNF gene polymorphisms have been associated with bipolar disorder. We tested two genetic polymorphisms of BDNF for their association with childhood‐onset mood disorders (COMD) within the context of a case‐control design. Two BDNF polymorphisms, a dinucleotide repeat (GT)n, and a single nucleotide polymorphism (SNP) in the coding region, val66met, were genotyped in 99 adults with a history of COMD and matched psychiatrically healthy controls. A genomic control (GC) method was used to evaluate population substructure. Alleles at (GT)n were highly associated with COMD in this sample (χ2 = 17.8; d.f. = 5; P = 0.0032). The odds of carrying the 168 bp allele were 3.94 times greater for cases than controls (CI = 1.72–9.04). Alleles of val66met were not significantly associated with COMD. GC analysis suggested population substructure was not a confounder of association. Analysis of haplotypes, in which (GT)n was treated as a binary variable (long vs. short alleles), provided significant evidence that the haplotype val/short contributes to liability to COMD. The BDNF (GT)n marker and the val/short haplotype are associated with COMD in this sample, in accordance with the previously described neurotrophic hypothesis of depression and some previous studies of association for bipolar disorder and neuroticism. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148‐7299:1/suppmat/index.html. © 2004 Wiley‐Liss, Inc.
Pervaporation of water/alcohol mixtures through chitosan/cellulose acetate composite hollow‐fiber membranes
Authors: Tsai H. A. , Chen H. C. , Chou W. L. , Lee K. R. , Yang M. C. , Lai J. Y. 
Published: September 2004

AbstractFor the purpose of separating aqueous alcohol by the use of pervaporation technique, a composite membrane of chitosan (CT) dip‐coated cellulose acetate (CA) hollow‐fiber membranes, CT‐d‐CA, was investigated. The effects of air‐gap distance in the spinning of CA hollow‐fiber membranes, chitosan concentration, and sorts of aqueous alcohol solutions on the pervaporation performances were studied. Compared with unmodified CA hollow‐fiber membrane, the CT‐d‐CA composite hollow‐fiber membrane effectively increases the permselectivity of water. The thickness of coating layer increases with an increase in chitosan concentration. As the concentration of chitosan solution increased, the permeation rate decreased and the concentration of water in the permeate increased. In addition, the effects of feed composition and feed solution temperature on the pervaporation performances were also investigated. The permeation rate and water content in permeate at 25°C for a 90 wt % aqueous isopropanol solution through the CT‐d‐CA composite hollow‐fiber membrane with a 5‐cm air‐gap distance spun, 2 wt % chitosan dip‐coated system were 169.5 g/m2 h and 98.9 wt %, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1562–1568, 2004
Preparation and thermomechanical characterization of poly(vinyl chloride) blends compatible with terpolymer‐containing maleic anhydride
Authors: Boztuğ Ali 
Published: September 2004

AbstractIn this study, I aimed to change the thermomechanical characteristics of poly(vinyl chloride) (PVC), which is widely used in commercial areas. Copolymers containing maleic anhydride (MA) units are commonly used to obtain compatible polymer blends. In our study, PVC blends were also prepared with the terpolymers with and without anhydride units. I assumed that the impact of the terpolymer on the thermomechanical characteristics of the PVC material could be more effectively controlled. For this purpose, two sets of six different blends of PVC with or without MA were synthesized, among which one was pure PVC, but the other five blends contained 2, 4, 6, 8, and 10% terpolymer. In conclusion, I observed that the terpolymer with the MA unit more regularly changed the thermomechanical characteristics of PVC. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1586–1589, 2004
Swelling behavior of thermoreversible poly(N‐isopropylacrylamide‐co‐N‐vinylimidazole) hydrogels
Authors: Işık Belma , Günay Yekta 
Published: September 2004

AbstractThermoresponsive hydrogels based on N‐isopropylacrylamide and N‐vinylimidazole were synthesized, and their swelling–deswelling behavior was studied as a function of the total monomer concentration. For copolymeric structures with better thermoresponsive properties with respect to poly(N‐isopropylacrylamide‐co‐N‐vinylimidazole) hydrogels, these hydrogels were protonated with HCl and HNO3, and the copolymer behaviors were compared with those of the unprotonated hydrogels. The temperature was changed from 4 to 70°C at fixed pHs and total ionic strengths. The equilibrium swelling ratio, dynamic swelling ratio, and dynamic deswelling ratio were evaluated for all the hydrogels. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1619–1624, 2004
Mathematical simulation of dynamic coupled heat and liquid moisture transfer in multilayer anisotropic porous polymers
Authors: Li Y. , Wang Z. 
Published: September 2004

AbstractA one‐dimensional mathematical model describing the dynamic coupled heat and moisture transfer inside multilayered porous polymers and anistropic materials is developed in this reported study. Compared to models published previously, three improvements have been made: (1) the model takes into account the dynamic complex behavior of coupled heat and liquid moisture transfer inside each layer; (2) the model provides different (inter‐) boundary conditions that correspond with the contact situations between neighbored layers and the influences from waterproof fabrics; and (3) the combinations of different types of polymer fibers in each layer and their roles with respect to processes of heat and moisture transfer. Physical experiments for liquid transfer, through the layered fabric assemblies with different construction, were carried out to validate the developed model in terms of dynamic temperature and moisture concentration distribution in the assembly, as well as the initial and final absolute liquid volumetric fractions at the surface of the top layer. Good agreement between the calculated and experimental results was obtained. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1590–1605, 2004
Carboxymethylation of Cassia occidentalis seed gum
Authors: Gupta Sarika , Sharma Pradeep , Soni P. L. 
Published: September 2004

AbstractThe seeds of Cassia occidentalis, an annual weed occurring throughout India, are a rich source of galactomannan gum. The gum derived from seed endosperm can be utilized in a number of industries to replace conventional gums. With a view to utilize the gum for broader applications, carboxymethylation of Cassia occidentalis seed gum was carried out. The reaction conditions were optimized with respect to concentration of monochloroacetic acid, sodium hydroxide, solvent ratio, reaction time, and reaction temperature. Rheological studies of carboxymethyl gum exhibited relatively high viscosity and stability vis‐a‐vis unmodified Cassia occidentalis gum. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1606–1611, 2004
Preparation of cadmium sulfide/poly(methyl methacrylate) composites by precipitation with compressed CO2
Authors: Li Zhonghao , Zhang Jianling , Du Jimin , Mu Tiancheng , Liu Zhimin , Chen Jing , Han Buxing 
Published: September 2004

AbstractCadmium sulfide (CdS) nanoparticles and poly(methyl methacrylate) (PMMA) were first synthesized in methyl methacrylate (MMA)/sodium bis(2‐ethylhexyl) sulfosuccinate (AOT) microemulsion, in which MMA acts as the solvent and monomer. Then compressed CO2 was used as an antisolvent to precipitate the CdS and PMMA simultaneously. Using this method, a CdS/PMMA composite was successfully prepared. The CdS nanoparticles dispersed in the polymer matrices were characterized by transmission electron microscopy. The higher pressure is favorable to producing CdS nanoparticles of smaller size. The phase structure of the obtained composite was characterized by X‐ray diffraction, which reveals that cubic CdS particles were formed. The FTIR spectra of the composite showed that there is no chemical bonding or strong interaction between CdS and PMMA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1643–1648, 2004
Recovery of heavy metals from aqueous solution by using radiation crosslinked poly(vinyl alcohol)
Authors: Hegazy El‐Sayed A. , El‐Salmawy K. M. , El‐Naggar A. A. 
Published: September 2004

AbstractCrosslinked poly(vinyl alcohol) (PVA) and PVA/acrylic acid hydrogels, prepared by γ‐irradiation, were used in the removal of heavy metals from aqueous solution. Comparative studies of the properties of the two hydrogels were made. The application of the prepared hydrogels as adsorbent materials for Cu2+, Co2+, and Ni2+ from aqueous solution was studied. The chemical and physical properties of the hydrogels, before and after adsorption of the heavy metal ions, were investigated by means of thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. The efficiency of such hydrogels for the recovery of metal ions was determined by atomic absorption and UV spectroscopic analysis. The effect of changing pH on the metal uptake was also studied. It was found that the prepared hydrogels have a substantial ability to adsorb metal ions from their solution. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1649–1656, 2004
Confusing dinosaurs with mammals: Tetrapod phylogenetics and anatomical terminology in the world of homology
Authors: Harris Jerald D. 
Published: September 2004

AbstractAt present, three different systems of anatomical nomenclature are available to researchers describing new tetrapod taxa: a nonstandardized traditional system erected in part by Sir Richard Owen and subsequently elaborated by Alfred Romer; a standardized system created for avians, the Nomina Anatomica Avium (NAA); and a standardized system for extant (crown‐group) mammals, the Nomina Anatomica Veterinaria (NAV). Conserved homologous structures widely distributed within the Tetrapoda are often granted different names in each system. The recent shift toward a phylogenetic system based on homology requires a concomitant shift toward a single nomenclatural system also based on both evolutionary and functional morphological homology. Standardized terms employed in the NAA and NAV should be perpetuated as far as possible basally in their respective phylogenies. Thus, NAA terms apply to nonavian archosaurs (or even all diapsids) and NAV terms apply to noncrown‐group mammals and more basal synapsids. Taxa equally distant from both avians and crown‐group mammals may maintain the traditional nonstandardized terminology until a universal anatomical nomenclature for all tetrapods is constructed. © 2004 Wiley‐Liss, Inc.
The bibliometric properties of article readership information
Authors: Kurtz Michael J. , Eichhorn Guenther , Accomazzi Alberto , Grant Carolyn , Demleitner Markus , Murray Stephen S. , Martimbeau Nathalie , Elwell Barbara 
Published: September 2004

AbstractDigital libraries such as the NASA Astrophysics Data System (Kurtz et al., 2005) permit the easy accumulation of a new type of bibliometric measure, the number of electronic accesses (“reads”) of individual articles. We explore various aspects of this new measure. We examine the obsolescence function as measured by actual reads and show that it can be well fit by the sum of four exponentials with very different time constants. We compare the obsolescence function as measured by readership with the obsolescence function as measured by citations. We find that the citation function is proportional to the sum of two of the components of the readership function. This proves that the normative theory of citation is true in the mean. We further examine in detail the similarities and differences among the citation rate, the readership rate, and the total citations for individual articles, and discuss some of the causes. Using the number of reads as a bibliometric measure for individuals, we introduce the read–cite diagram to provide a two‐dimensional view of an individual's scientific productivity. We develop a simple model to account for an individual's reads and cites and use it to show that the position of a person in the read–cite diagram is a function of age, innate productivity, and work history. We show the age biases of both reads and cites and develop two new bibliometric measures which have substantially less age bias than citations: SumProd, a weighted sum of total citations and the readership rate, intended to show the total productivity of an individual; and Read10, the readership rate for articles published in the last 10 years, intended to show an individual's current productivity. We also discuss the effect of normalization (dividing by the number of authors on a paper) on these statistics. We apply SumProd and Read10 using new, nonparametric techniques to compare the quality of different astronomical research organizations.
Development characterization and use of a high‐performance enzymatic time‐temperature integrator for the control of sterilization process' impacts
Authors: Guiavarc'h Yann , Van Loey Ann , Zuber François , Hendrickx Marc 
Published: September 2004

AbstractA small sized single‐component enzymatic time temperature integrator (TTI) was developed. It consisted of glass beads coated with Bacillus licheniformis α‐amylase (BLA) and stabilizing additives in a dehydrated form. Post heating residual enzymatic activity was used as a response property of the TTI. Under isothermal conditions, different batches of the system were characterized by zTTI‐values around 13.5°C in the temperature range 100‐130°C as well as by their ability to provide a response within 5 min after thermal processing. When used under non‐isothermal conditions in a model food (silicone spheres), the system allowed to measure process‐values zTTIF121.1°C up to 60 min with an average error of 10.9%. The capabilities of the system were validated in a real solid/liquid food matrix sterilized by retorting. The combination of FTTI‐values with heat transfer simulations based on finite difference calculations allowed for the determination of process values, which evaluated actual process‐values 10°CF121.1°C up to 90 min with an average error of 11.4%. The good performances of the system as well as its easiness of preparation and use, make the latter a valuable biological device for thermal process assessment. © 2004 Wiley Periodicals, Inc.
Membrane chromatography of DNA: Conformation‐induced capacity and selectivity
Authors: Haber Charbel , Skupsky Jonathan , Lee Ann , Lander Russ 
Published: September 2004

AbstractThe chromatographic purification of biological macromolecules requires a novel approach to overcome some of the pore size limitations of commercially available resins. Membrane adsorbers offer the potential for better resolution as well as productivity. Sharp peaks are gained by the rapid exchange rate with the adsorbing membranes associated with the convective flow path, in contrast to the pore diffusion requirement for resin exchange. The resolution advantage is preserved even when the very short bed heights of membranes are exploited for the purpose of exceptionally high flow rates and productivity.Breakthrough experiments were used to assess the membrane dynamic loading capacities of flexible macromolecules using supercoiled (SC) DNA as a model system. In contrast to reports for smaller biomolecules such as proteins and antibodies, the dynamic capacity for DNA was found to be highly dependent on flow rates and concentrations. Increasing flow rates induced DNA elongation, which increased the surface coverage and, in turn, lowered the capacity. Increasing concentrations beyond C*, the overlap concentration, led to exclusion‐volume interactions, which reduced the size of DNA and increased the membrane adsorber capacity. In the chromatographic mode, membranes with a strongly positive charge were able to resolve various isoforms of DNA, surpassing the capabilities of analogous chromatographic resins. In this study, we found that the convective‐flow‐induced‐structural behavior of DNA is responsible for the resolution in separation. © 2004 Wiley Periodicals, Inc.
Fractionation of protein, RNA, and plasmid DNA in centrifugal precipitation chromatography using cationic surfactant CTAB containing inorganic salts NaCl and NH4Cl
Authors: Tomanee Panarat , Hsu James T. , Ito Yoichiro 
Published: September 2004

AbstractCentrifugal precipitation chromatography (CPC) is a separation system that mainly employs a moving concentration gradient of precipitating agent along a channel and solutes of interest undergo repetitive precipitation‐dissolution, fractionate at different locations, and elute out from the channel according to their solubility in the precipitating agent solution. We report here for the first time the use of a CPC system for fractionation of protein, RNA, and plasmid DNA in clarified lysate produced from bacterial culture. The cationic surfactant cetyltrimethylammonium bromide (CTAB) was initially used as a precipitating agent; however, all biomolecules showed no differential solubility in the moving concentration gradient of this surfactant and, as a result, no separation of protein, RNA, and plasmid DNA occurred. To overcome this problem, inorganic salts such as NaCl and NH4Cl were introduced into solution of CTAB. The protein and RNA were found to have higher solubility with the addition of these salts and separated from the plasmid DNA. Decreasing surface charge density of CTAB upon addition of NaCl and NH4Cl was believed to lead to lower surfactant complexation, and therefore caused differential solubility and fractionation of these biomolecules. Addition of CaCl2 did not improve solubility and separation of RNA from plasmid DNA. © 2004 Wiley Periodicals, Inc.
Self‐assembly DNA‐conjugated polymer for detection of single nucleotide polymorphism
Authors: Taira Shu , Yokoyama Kenji 
Published: September 2004

AbstractWe developed a self‐assembly DNA‐conjugated polymer based on polyacrylic acid (PAA) for DNA chip fabrication. A 20‐mer single‐stranded DNA (ssDNA, probe‐1), and 3‐(2‐pyridyldithio)propionyl hydrazide (PDPH), for promoting self‐assembled immobilization, were both covalently attached to PAA as sidechains. This DNA‐conjugated PAA was then spontaneously immobilized on a gold substrate. Probe‐1 on the immobilized polymer was hybridized to a 34‐mer ssDNA (probe‐2), which had the sequence desired for analyzing the target DNA. The fluorescence intensity after incubating the P‐1 DNA‐conjugated polymer with probe‐2 DNA was much higher than with control sequence in the first hybridization. The interactions between target DNA and the DNA‐conjugated PAA were investigated by fluorescence measurement. The interaction of fully matched target DNA with this immobilized DNA conjugated polymer has been studied at different ion strength conditions. SNP sequences as targets showed less than 15% the intensity of fully matched target DNA in the second hybridization, indicating that the gold surfaces coated with the DNA‐conjugated PAA was highly specific to fully matched DNA. The DNA‐conjugated PAA immobilized on a gold substrate is characterized by reduced nonspecific adsorption, due to less electrostatic repulsion as well as the polymer coating. Therefore, DNA‐conjugated PAA can be used for probe DNA immobilization method. © 2004 Wiley Periodicals, Inc.
Roles and applications of small heat shock proteins in the production of recombinant proteins in Escherichia coli
Authors: Han Mee‐Jung , Park Si Jae , Park Tae Jung , Lee Sang Yup 
Published: September 2004

AbstractProteome profiling of the inclusion body (IB) fraction of recombinant proteins produced in Escherichia coli suggested that two small heat shock proteins, IbpA and IbpB, are the major proteins associated with IBs. In this study, we demonstrate that IbpA and IbpB facilitate the production of recombinant proteins in E. coli and play important roles in protecting recombinant proteins from degradation by cytoplasmic proteases. We examined the cytosolic production, and Tat‐ or Sec‐dependent secretion of the enhanced green fluorescent protein (EGFP) in wild type, ibpAB− mutant, and ibpAB‐amplified E. coli strains. Analysis of fluorescence histograms and confocal microscopic imaging revealed that over‐expression of the ibpA and/or ibpB genes enhanced cytosolic EGFP production whereas knocking out the ibpAB genes enhanced secretory production. This strategy seems to be generally applicable as it was successfully employed for the enhanced cytosolic or secretory production of several other recombinant proteins in E. coli. © 2004 Wiley Periodicals, Inc.
Macrolide‐ and tetracycline‐adjustable siRNA‐mediated gene silencing in mammalian cells using polymerase II‐dependent promoter derivatives
Authors: Malphettes Laetitia , Fussenegger Martin 
Published: September 2004

AbstractRNA interference has emerged as a powerful technology for downregulation of specific genes in cells and animals. We have pioneered macrolide‐ and tetracycline‐adjustable short interfering RNA (siRNA) expression for conditional target gene translation fine‐tuning in mammalian/human cell lines based on modified RNA polymerase II promoters. Established macrolide‐ and tetracycline‐dependent transactivators/trans‐silencers bound and activated modified target promoters tailored for optimal siRNA expression in response to clinical antibiotics' dosing regimes and modulated desired target genes in Chinese hamster ovary (CHO‐K1) and human fibrosarcoma (HT‐1080) cells with high precision. Further optimization of adjustable RNA polymerase II‐based siRNA‐specific promoters as well as their combination with various transmodulators enabled near‐perfect regulation configurations in specific cell types. Devoid of major genetic constraints compared to basic RNA polymerase III‐based siRNA‐specific promoters, we expect RNA polymerase II counterparts to significantly advance siRNA‐based molecular interventions in biopharmaceutical manufacturing and gene‐function analysis as well as gene therapy and tissue engineering. © 2004 Wiley Periodicals, Inc.