bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of SEBS on interfacial tension and rheological properties of LDPE/PS blend
Authors: Nam G. J. , Kim K. Y. , Lee J. W. 
Published: February 2005

AbstractThe effects of SEBS as a compatibilizer on the interfacial tension and rheological properties of LDPE/PS blend have been studied. Interfacial tension was measured by the breaking thread method. The measured interfacial tension of the LDPE/PS blend was 8.26 dyn/cm. It decreased rapidly with SEBS contents to 1 wt % and then leveled off to a saturation value, 3.6 dyn/cm. Dynamic oscillatory shear, elongational viscosity, and recovery after elongation were measured as the rheological properties. Storage modulus at low frequencies decreased with SEBS contents to 1 wt %. More addition of SEBS, however, increased the storage modulus at low frequencies. Similar behaviors could be observed in elongation viscosity and recovery after elongation. Hardening of elongational viscosity and recovery after elongation were reduced with 1 wt % SEBS, and they enhanced again with more SEBS contents. This means that there is a critical concentration of SEBS that acts as a compatibilizer and reduces the interfacial tension. More SEBS than the critical concentration saturates the interface and increases the elasticity of the LDPE/PS blend, while maintaining the interfacial tension between LDPE and PS constant. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 905–911, 2005
Chemical silver plating and its application to textile fabric design
Authors: Jiang S. Q. , Newton E. , Yuen C. W. M. , Kan C. W. 
Published: February 2005

AbstractMetalization is one of the finishing processes in textile treatments that can produce fabrics with a unique appearance. It has great potential for textiles and garments, including functional and decorative effects. Chemical plating is an autocatalytic deposition method for precision work in conventional manufacturing. In this study, the operation and final properties of the chemical silver plating of cotton and polyester fabrics were investigated. The results showed that a specific performance of silver‐plated fabric could be obtained if the optimum chemical‐plating conditions were chosen. In addition, a fabric design practice employed by this chemical technique with a craft approach achieved a diverse effect. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 919–926, 2005
Synthesis and permeability properties of crosslinkable elastomeric poly(vinyl allyl dimethylsilane)s
Authors: Kim Taek‐Joong , Bryantseva I. S. , Borisevich O. B. , Syrtsova D. A. , Khotimsky V. S. , Roizard D. , Teplyakov V. V. 
Published: February 2005

AbstractThis article presents the results of a systematic synthesis study of elastomeric crosslinkable polysilicon olefins, the related thermal crosslinking kinetics, and the main permeability parameters recorded for inorganic gases (He, N2, O2, and CO2) and C1–C7 hydrocarbons. Poly(vinyl allyl dimethylsilane) (PVADMS; glass‐transition temperature < 273°K) was obtained by the anionic polymerization of bifunctional vinyl allyl dimethylsilane monomer. The polymers were amorphous, high molecular compounds with mixed carbo‐heterochain structures containing double bonds capable of intermolecular crosslinking under a thermal treatment. Thus, thermally crosslinked polymers exhibited a high resistance toward exposure to organic vapors, unlike noncrosslinked PVADMS. IR spectroscopy was used to investigate the polymer structural changes induced by the thermal treatment. An original technique based on a differential method was used to measure gas permeability during thermal crosslinking. PVADMS possessed higher permeability for C1–C7 hydrocarbons than for inorganic gases (excluding CO2), even after crosslinking. Permeability coefficients ranging from 140 to 1780 Barrer for He and CH4 were found before crosslinking; the thermal crosslinking induced a nonlinear permeability decrease that could be correlated with the disappearance of the double bonds in the polymer structures, that is, cis‐CHCH, trans‐CHCH, and CH2CH in the side‐chain position. According to the found properties, PVADMS could be used as a prospective material for the preparation of highly permeable selective membranes suitable for lower hydrocarbon and volatile organic compound recovery from various chemical and petrochemical process streams. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 927–935, 2005
Human and murine class I histocompatibility antigens: Four years after cloning
Authors: Jordan Bertrand R. 
Published: February 2005

AbstractThe serological properties of the major histocompatibility (class I) antigens of mammals have raised many questions about the structure and function of these molecules. Over the past four years the cloning of their gene sequences has begun to provide some of the answers to these questions. The structural analyses have demonstrated close similarities between class I genes of man and mouse, established the existence of numerous class I pseudogenes in human and murine genomes, and indicated the importance of gene conversion events in regulating the sequence diversity of this gene family. In addition, the ability to construct new class I genes in vitro and to transfect cultured murine cells with the synthetic sequences is permitting new tests of the functional organization of these genes in relation to their structure.
The analysis of protein structures: New insights from a growing data base
Authors: Lesk Arthur M. 
Published: February 2005

AbstractWe now know the structures of over 200 proteins to atomic resolution. Despite the impressive extent and quality of the results, crystal‐structure analysis has often been thought of as limited in scope, not only in its restriction to samples that can be crystallized, but in the more important respect that taking ‘snapshots’ of proteins does not directly address the complex spatio‐temporal organization of the processes in which proteins participate. It is suggested here that, as the field has matured, this second limitation is gradually being overcome. As we gain increased access to structures of proteins in different conformational states – for example, in conformations produced by different states of ligation – and to families of homologous proteins, we can proceed from the statics of protein structure to the dynamics of conformational change, function, and evolution.A new scientific speciality has grown up around the solved structures: it has as its goal the elucidation of general principles of protein structure and function, to provide a theoretical framework for understanding the properties of proteins revealed by experiment. In this article we shall discuss some of the activity in this field. It will emerge clearly, I believe, that the increasing number and variety of solved structures is exerting a cumulative force. General principles are emerging from comparisons of related proteins and contrasts of dissimilar ones: the whole corpus of data is greater than the sum of the parts.
Specialized Nucleoprotein Structures in high‐fidelity DNA transactions
Authors: Echols Harrison 
Published: February 2005

AbstractThree proteins used to initiate DNA replication and carry out site‐specific recombination in E. coli generate organized nucleoprotein structures at their target sites. The association of proteins bound at multiple sites on DNA presumably folds or winds the DNA to produce a specific three‐dimensional conformation. This specialized nucleoprotein structure may be a general mechanism for achieving very high fidelity in DNA transactions in which even a rare mistake must be avoided. The overall interaction is more complex than that of prokaryotic transcription regulators studied so far, but might be characteristic of eukaryotic transcription regulators, for which the problem of site‐localization is more difficult.
Designing microorganisms for insect control
Authors: Lüthy Peter , Arif Basil M. 
Published: February 2005

AbstractMicroorganisms belong to the main regulators of insect populations under natural conditions. They perform this function in several ways. In the first place, bacterial metabolites exist which are as potent as chemical insecticides. In the second, entomopathogenic fungi and viruses spread deadly infections among insect populations. The use of advanced techniques in molecular biology, genetic engineering and biotechnology is increasingly expanding the potential of microorganisms as agents of insect pest control.
Hormones, second messengers and the reversible phosphorylation of proteins: An overview
Authors: Cohen Philip 
Published: February 2005

AbstractThe interconversion of key regulatory proteins between phosphorylated and dephosphorylated forms is an extremely versatile mechanism for reversible altering their activities, and in mammalian cells may be almost as common as allosteric regulation. It is now evident that protein phosphorylation is the basis of a complex network of interlocking systems which allow a variety of hormones and other extracellular signals, acting through just a few second messengers to coordinate biochemical functions.
The coordination of cell growth and division — intentional or Incidental?
Authors: Tyson John J. 
Published: February 2005

AbstractDuring balanced growth of cells in culture all extensive properties of the culture — e.g. cell number, total mass, total DNA content — increase exponentially at the same specific growth rate. Therefore, in some average sense, each component of a cell must double between birth and division. For DNA there exists an elaborate mechanism to ensure precise replication of the genetic material and accurate partitioning of identical copies of the genome to the two daughter cells. Do cells possess another mechanism that intentionally relates the timing of cell division to overall increase in cell size, or is the coordination of growth and division an incidental consequence of size‐independent rules for progress through the cell cycle?.
Modulation of cAMP effects by Ca2+/calmodulin
Authors: Pallen Catherine J. , Sharma Rajendra K. , Wang Jerry H. 
Published: February 2005

AbstractThe second messenger molecules cAMP and Ca2+ regulate a large number of eukaryotic cellular events. cAMP acts on protein kinases and Ca2+ works through a ubiquitous calcium‐binding protein, calmodulin. The two systems are not independent, however, but interact in several important fashions. These interactions, and, in particular, the modulation of the cAMP signal by two Ca2+/calmodulin‐regulated proteins, cyclic nucleotide phosphodiesterase and calcineurin, are described here.
What' New: More advances in DNA sequencing technology
Authors: Wilde Deborah 
Published: February 2005

AbstractSince their introduction about ten years ago the rapid methods for sequencing DNA based either on selective chemical degradation1 or primed enzymatic synthesis2 have been subject to a number of modifications and improvements.3, 4 Two recently published papers describe further advances in these technologies: a method for obtaining information about DNA sequences directly from uncloned mammalian genomic DNA5 and a possible first step towards the automation of DNA sequencing6.
Structural and functional domains of tubulin
Authors: Maccioni Ricardo B. , Serrano Luis , Avila Jesus 
Published: February 2005

AbstractThe molecular aspects of the microtubule system is a research area that has developed very rapidly during the past decade. Research on the assembly mechanisms and chemistry of tubulin and the molecular biology of microtubules have advanced our understanding of microtubule formation and its regulation. The emerging view of tubulin is of a macromolecule containing spatially discrete sequences that constitute functionally different domains with respect to self‐association, interactions with microtubule associated proteins (MAPs) and specific ligands. Recent studies point to the role of the carboxyl‐terminal moiety of tubulin subunits in regulating its assembly into microtubules. These investigations combined with further studies on the spatial relationships between tubulin domains should provide new insights into the detailed structural basis of microtubule assembly.
What the papers say: Keeping it in the family: How T cells make antigen receptors
Authors: Tunnacliffe Alan 
Published: February 2005

AbstractThe last year has unveiled extensive information on the T‐cell antigen receptor genes. For both the α‐ and β‐chains of this molecule, it is clear that an expressed gene is compiled from several coding sequences dispersed along the chromosome. During T‐cell development, recombination events occur which create a single transcription unit from these dispersed elements. Such gene organization shows that the T‐cell receptor has close evolutionary links with immunoglobulins. Both types of molecule use the same genetic mechanisms to create the diversity necessary for antigen recognition.
Antenatal diagnosis by DNA analysis: Current status, future developments… and a few unanswered questions
Authors: Jordan B. R. 
Published: February 2005

AbstractProgress in recombinant DNA technology and in mapping of the human genome makes it possible to diagnose genetic defects as early as 8–10 weeks after conception for an increasing number of genetic diseases. Further developments will bring wider applicability and increased sensitivity, making widespread application of this type of diagnosis possible. Logistical and ethical problems will however arise in the course of this development.
Bacterial plasmid stability
Authors: Summers David K. , Sherratt David J. 
Published: February 2005

AbstractBacterial plasmids are ubiquitous ‘minichromosomes’ that have major importance in clinical microbiology, as agents of pathogenicity and as carriers of antibiotic resistance, and in molecular genetics, through their role as vectors in gene manipulation. Plasmids carry a wide range of dispensable, transiently useful and often bizarre functions.1 Naturally occurring plasmids, in addition to modifying the host cell phenotype, carry genes involved in the control of their own vegetative replication, plasmid copy number2 and stable inheritance. They may also carry determinants for the conjugal transfer of DNA between bacteria.3 Whereas low‐copy‐number plasmids must be partitioned by some active process during cell division, the evidence suggests that multicopy plasmids are distributed randomly between daughter cells. Two independent determinants are necessary for the stable inheritance of multicopy plasmids, and both of these appear to act by maximizing the number of independent plasmid molecules.
Homologous recombination promoted by Chi sites and RecBC enzyme of Escherichia coli
Authors: Smith Gerald R. , Stahl Franklin W. 
Published: February 2005

AbstractChi sites are examples of special sites enhancing homologous recombination in their region of the chromosome. Chi, 5′ G‐C‐T‐G‐G‐T‐G‐G3′, is a recognition site for the RecBC enzyme, which nicks DNA near Chi as it unwinds DNA. A molecular model of genetic recombination incorporating these features is reviewed.
Host cell–plasmid interactions in the expression of DNA donor activity by F+ strains of Escherichia coli K‐12
Authors: Silverman Philip M. 
Published: February 2005

AbstractDNA transfer directly from cell to cell (conjugation) is common among prokaryotes, particularly Gram‐negative bacteria like Escherichia coli. The phenomenon invariably requires a set of plasmid genes in the DNA donor cell. In addition, E. coli itself makes limited and specific contributions to the donor activity of strains carrying the conjugative plasmid F. These contributions have yet to be defined biochemically, but it is already clear that the cell envelope is an importan nexus between plasmid‐ and chromosome‐encoded proteins required for the establishment and maintenance of DNA donor activity.
The linkage of actin to non‐erythroid membranes
Authors: Brown Susan S. 
Published: February 2005

AbstractThe question of how actin filaments are attached to membranes is of central importance to an understanding of how actin gives rise to shape and movement in cells. A number of approaches to this question have been taken, but there have been few definitive answers. Some of the limitations of these approaches are discussed, as well as possible avenues for overcoming them.
Induction of plant gene expression by light
Authors: Thompson William F. , Kaufman L. S. , Watson J. C. 
Published: February 2005

AbstractLight effects on the activity of several genes have recently been exploited in studies of plant gene expression. We discuss here some examples involving nuclear genes of higher plants, with emphasis on responses mediated by the phytochrome system. Recent work has revealed considerable diversity in the responses of different genes, indicating that several different regulatory programs are probably involved. A start has been made in studies of nuclear events associated with the changes in expression. Transcriptional regulation almost certainly occurs, although many details remain to be studied and effects on mRNA processing and turnover have not been ruled out. Recent in vitro mutagenesis and gene transfer experiments with the gene for the small subunit of RuBP carboxylase indicate that sequences involved in regulating the level of expression in the light are located 5′ to the gene within about 1 kb of the start of transcription.
Plant cell culture and natural product synthesis: An academic dream or a commercial possibility?
Authors: Fowler M. W. 
Published: February 2005

AbstractWork with plant cell cultures has developed rapidly in recent years, progress being manifested particularly by the development of commercial process technology for the synthesis of selected natural products. The economics of operating a plant‐cell culture process are, however, still questionable, and a great deal still needs to be done to strengthen the underlying science before the technology can be regarded as industrially commonplace. Nonetheless, the great versatility of plants as centres of chemical synthesis suggests that, with appropriate developments in cell culture technology, this area may have a significant role to play in the fine chemicals industry of the future.
The interleukin‐1 family of molecules
Authors: Allison Anthony C. 
Published: February 2005

AbstractTwo types of interleukin 1 (IL‐1α and IL‐1β) have been defined by purifying the molecules from activated human peripheral blood cells, followed by cloning and expressing the molecules in Escherichia coli. Both types of IL‐1 stimulate proliferation and differentiation of T‐ and B‐lymphocytes and induce cartilage proteoglycan degradation but differ in other properties. For example, demineralization and appears to be a major mediator in the pathogenesis of joint erosion in rheumatoid arthritis. Synthetic adjuvants elicit the production of IL‐1 separate from endogenous pyrogen, and this property is required for the new generation of vaccines based on antigens produced by recombinant DNA technology.
Strategies for the design and use of tumor‐reactive human monoclonal antibodies
Authors: Gaffar S. A. , Royston I. , Glassy M. C. 
Published: February 2005

AbstractHuman hybridomas secreting monoclonal antibodies (MoAb) reactive with tumor cell antigens were produced in our laboratory by the immortalization of UC 729‐6 with B lymphocytes isolated from regional draining lymph nodes of cancer patients. MoAbs were purified from the hybridoma supernates by standard biochemical procedures for in vivo studies and by affinity methods for in vitro experiments. Using a novel method in the preparation of slides containing adherent tumor cells, immunoreactivities of the MoAbs were evaluated by an indirect immunofluorescence assay. Based on this data, human MoAbs can, therefore, be used as research reagents.
What the papers say: A puff is born
Authors: Spierer Pierre 
Published: February 2005

AbstractPuffing of polytene chromosomes is associated with intense genetic activity. Genetic determinants of puffing in Drosophila can now be dissected by transplanting genes known to puff to other chromosomal locations by transposonmediated germ line transformation. Recent studies show that induction of a heat shock puff requires only about one hundred and fifty base pairs of DNA upstream of the gene, around the start of transcription, and not the protein coding sequence itself. Moreover, the size of the ‘ectopic’ puff was found to be related to the size of the corresponding transcript. Similar work is now in progress with hormonally‐controlled puffs.
Role of mammalian circular DNA in cellular differentiation
Authors: Yamagishi Hideo 
Published: February 2005

AbstractThe presence of small polydisperse extrachromosomal circular (spc) DNAs composed entirely of chromosomal sequences seems to reflect the plasticity of eukaryotic genomes. The size distribution and number of spc DNAs is found to vary with development, growth state and mitotic capacity. In particular, spc DNAs are observed to be several fold smaller in established immortal cell lines than in diploid cells with a limited life span. Analysis of cloned spc DNA fragments revealed that: (1) most of the spc DNAs thus far investigated contain repetitive sequences; (2) some of the repetitive sequences are enriched in spc DNA clones relative to their representation in the chromosome; (3) various repetitive sequences of different reiteration frequency were found in spc DNA from immortal cell lines while a particular sequence of retroposon was predominant in primary lymphoid tissue cells and stem cells; (4) most of these spc DNAs appear to represent the extra copies generated by replicon‐misfiring in immortal cell lines or by retrotranscription in stem cells, and intermediates or by‐products produced by abortive rearrangement in diploid cells with a finite replicative capacity.
What's new: Immunotoxins
Authors: Blakey David C. , Thorpe Philip E. 
Published: February 2005

AbstractImmunotoxins are hybrid molecules formed by coupling antibody molecules to powerful toxins of plant or bacterial origin. In experimental systems, immunotoxins have been found to kill cancer cells with great potency and specificity. This article reviews the current status of immunotoxins and some of the problems that have to be overcome before they can be used to treat human malignant disease.
The regulation of cellular differentiation in the dimorphic yeast Candida albicans
Authors: Soll David R. 
Published: February 2005

AbstractDimorphism in the yeast Candida albicans provides an unusually simple model system for investigating the mechanisms which regulate cellular differentiation, or cell divergence. Under the regime of pH‐regulated dimorphism, it has been demonstrated that the programs of protein synthesis accompanying bud and hypha formation are strikingly similar. Instead of dramatic differences in the repertoire of gene products possessed by bud‐ and hypha‐forming cells, subtle temporal, spatial and quantitative differences in the same architectural events appear to be basic to the genesis of alternative phenotypes. This emerging story of phenotypic regulation does not exclude differential gene expression, but rather de‐emphasizes its role and underscores other mechanisms which are not generally considered.