WorldWideScience
 
 
1

Genetic Control of Capsid Length in Bacteriophage T4 I. Isolation and Preliminary Description of Four New Mutants  

UK PubMed Central (United Kingdom)

Four new mutants are described whose phenotypic expression affects the length of the head of bacteriophage T4D. All mutants produce some phenotypically normal phage particles. Mutant pt21-34...Full Text Available

1973-08-01

2

Biotin binders selected from a random peptide library expressed on phage.  

UK PubMed Central (United Kingdom)

Recombinant biotin-binding phages were affinity-selected from a random peptide library expressed on the surface of filamentous phage. Phage binding to biotinylated proteins was half-maximally inhibited...Full Text Available

1993-08-01

3

A rapid and efficient method for region- and strand-specific mutagenesis of cloned DNA.  

UK PubMed Central (United Kingdom)

The single-stranded viral DNA of an M13 phage recombinant containing the early promoter region of SV40 was hybridized with linear, double-stranded replicative form DNA of a related M13 phage containing...Full Text Available

1982-01-01

4

The role of the HCR system in the repair of lethal lesions of Bacillus subtilis phages and their transfecting DNA damaged by radiation and alkylating agents  

International Nuclear Information System (INIS)

The role of the HCR system in the repair of prelethal lesions induced by UV light, #gamma# radiation and alkylating agents was studied in the Bacillus subtilis SPP1 phage, its heat sensitive mutants (N3, N73 nad ts_1) and corresponding infectious DNA. The survival of phages and their transfecting DNA after treatment with UV light is substantially higher in hcr"+ cells than in hcr cells, the differences being more striking in intact phages than in their transfecting DNA's. Repair inhibitors reduce survival in hcr"+ cells: caffeine lowers the survival of UV-irradiated phage SPP1 in exponentially growing hcr"+ cells but has no effect on its survival in competent hcr"+ cells; acriflavin and ethidium bromide decrease the survival of the UV-irradiated SPP1 phage in both exponentially growing and competent hcr"+ cells to the level of survival observed in hcr cells; moreover, ethidium ...

5

Transposon mediated transgenesis in a marine invertebrate chordate: Ciona intestinalis  

UK PubMed Central (United Kingdom)

Achievement of transposon mediated germline transgenesis in a basal chordate, Ciona intestinalis, is discussed. A Tc1/mariner superfamily transposon,...Full Text Available

2007-01-01

7

Sustained Benefit Lasting One Year from T4 Instead of T3-T4 Sympathectomy for Isolated Axillary Hyperhidrosis  

UK PubMed Central (United Kingdom)

INTRODUCTIONLevel T4 video-assisted thoracoscopic sympathectomy proved superior to T3-T4 treatment for controlling axillary hyperhidrosis at the initial and six-month follow-ups...Full Text Available

2008-12-01

8

Consensus sequence L/PKSSLL mimics crucial epitope on Loop III of Taiwan cobra cardiotoxin  

British Library Electronic Table of Contents (United Kingdom)

Phage display is effective in screening peptides that mimic venom's neutralizing epitopes. A phage display cyclized heptapeptide library (C7C library) was panned with purified divalent antivenin IgG, which neutralizes Naja naja atra venom (NAV) and Bungarus multicinctus venom (BMV). The selected heptapeptide sequences were aligned with known protein sequences of NAV and BMV in GenBank. One of the four consensus sequences, L/PKSSLL, mimicked the crucial epitope on Loop III of Taiwan cobra cardiotoxin that is associated with the venom's lethal potency. In dot blot analysis, several clones showed varying reactivities for NAV monovalent antivenin and lesser cross-reactions with BMV monovalent antivenin. The KSSLLRN-carrying phage occurred four times in selected clones and showed the strongest ...

2009-01-01

9

The Pregnane X Receptor: From Bench to Bedside  

UK PubMed Central (United Kingdom)

BackgroundThe pregnane X receptor (PXR; NR1I2), a member of the nuclear receptor superfamily, regulates the expression of metabolic enzymes and transporters involved...Full Text Available

2008-07-01

10

Ixodes scapularis tick serine proteinase inhibitor (serpin) gene family; annotation and transcriptional analysis  

UK PubMed Central (United Kingdom)

BackgroundSerine proteinase inhibitors (Serpins) are a large superfamily of structurally related, but functionally diverse proteins that control essential proteolytic pathways in...Full Text Available

11

Intracellular delivery of an antisense?oligonucleotide via endocytosis of a G protein-coupled receptor  

UK PubMed Central (United Kingdom)

Gastrin-releasing peptide receptor (GRPR), a member of the G protein-coupled receptor superfamily, has been utilized for receptor-mediated targeting of imaging and therapeutic agents; here we extend...Full Text Available

2010-10-01

12

Identification of genetic variation and haplotype structure of the canine ABCA4 gene for retinal disease association studies  

UK PubMed Central (United Kingdom)

Over 200 mutations in the retina specific member of the ATP-binding cassette transporter super-family (ABCA4) have been associated with a diverse group of human retinal diseases....Full Text Available

2010-10-01

13

Homology of SMP domains to the TULIP superfamily of lipid-binding proteins provides a structural basis for lipid exchange between ER and mitochondria  

UK PubMed Central (United Kingdom)

Mitochondria must uptake some phospholipids from the endoplasmic reticulum (ER) for the biogenesis of their membranes. They convert one of these lipids, phosphatidylserine, to phosphatidylethanolamine,...Full Text Available

2010-08-15

14

Glutamate 2,3-aminomutase: a new member of the radical SAM superfamily of enzymes  

UK PubMed Central (United Kingdom)

SUMMARYA gene eam in Clostridium difficile encodes a protein that is homologous to lysine 2,3-aminomutase (LAM) in many other species but does...Full Text Available

2007-02-01

15

Cloning of the mouse hepatitis virus (MHV) receptor: expression in human and hamster cell lines confers susceptibility to MHV.  

UK PubMed Central (United Kingdom)

The cellular receptor for murine coronavirus mouse hepatitis virus (MHV)-A59 is a member of the carcinoembryonic antigen (CEA) family of glycoproteins in the immunoglobulin superfamily. We isolated...Full Text Available

1991-12-01

16

Activated PPAR? Targets Surface and Intracellular Signals That Inhibit the Proliferation of Lung Carcinoma Cells  

UK PubMed Central (United Kingdom)

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Their discovery in the 1990s provided insights...Full Text Available

2008-01-01

17

Vibrio cholerae Hemagglutinin/Protease Inactivates CTX?  

UK PubMed Central (United Kingdom)

Pathogenic strains of Vibrio cholerae are lysogens of the filamentous phage CTXφ, which carries the genes for cholera toxin (ctxAB). We found that the titers...Full Text Available

1998-09-01

18

Structural aberrations in group A Staphylococcus bacteriophages.  

UK PubMed Central (United Kingdom)

Six related Staphylococcus phages spontaneously produced various abnormal head and tail structures: (i) giant capsids which were tailed and apparently contained nucleic acid; (ii) regular and irregular...Full Text Available

1976-05-01

19

Escherichia coli MW005: lambda Red-mediated recombineering and copy-number induction of oriV-equipped constructs in a single host  

UK PubMed Central (United Kingdom)

BackgroundEscherichia coli strain EL350 contains chromosomally integrated phage lambda Red recombinase genes enabling this strain to be used for modifying the sequence...Full Text Available

20

Comparison of Genotypes of Salmonella enterica Serovar Enteritidis Phage Type 30 and 9c Strains Isolated during Three Outbreaks Associated with Raw Almonds?  

UK PubMed Central (United Kingdom)

In 2000 to 2001, 2003 to 2004, and 2005 to 2006, three outbreaks of Salmonella enterica serovar Enteritidis were linked with the consumption of raw almonds. The S....Full Text Available

2010-06-01

 
 
 
 
21

Isolation of a bacterial host selective for bacteriophage T4 containing cytosine in its DNA.  

UK PubMed Central (United Kingdom)

An Escherichia coli B strain, B834 galU56, has been isolated which supports growth of bacteriophage T4 with cytosine in its DNA while restricting growth of T4 with hydroxymethylcytosine. This host is...Full Text Available

1978-09-01

22

Biomagnetic separation of Salmonella Typhimurium with high affine and specific ligand peptides isolated by phage display technique  

Energy Technology Data Exchange (ETDEWEB)

Analyses of food-borne pathogens are of great importance in order to minimize the health risk for customers. Thus, very sensitive and rapid detection methods are required. Current conventional culture techniques are very time consuming. Modern immunoassays and biochemical analysis also require pre-enrichment steps resulting in a turnaround time of at least 24 h. Biomagnetic separation (BMS) is a promising more rapid method. In this study we describe the isolation of high affine and specific peptides from a phage-peptide library, which combined with BMS allows the detection of Salmonella spp. with a similar sensitivity as that of immunomagnetic separation using antibodies.

2007-04-15

23

Growth differentiation factor-9 stimulates progesterone synthesis in granulosa cells via a prostaglandin E2/EP2 receptor pathway  

UK PubMed Central (United Kingdom)

Growth differentiation factor-9 (GDF-9), an oocyte-secreted member of the transforming growth factor β superfamily, progesterone receptor, cyclooxygenase 2 (Cox2; Ptgs2), and the EP2 prostaglandin...Full Text Available

2000-08-29

24

Dual Functions of ASCIZ in the DNA Base Damage Response and Pulmonary Organogenesis  

UK PubMed Central (United Kingdom)

Zn2+-finger proteins comprise one of the largest protein superfamilies with diverse biological functions. The ATM substrate Chk2-interacting Zn2+-finger protein...Full Text Available

2010-10-01

25

Characterization of a Novel Small Molecule Subtype Specific Estrogen-Related Receptor ? Antagonist in MCF-7 Breast Cancer Cells  

UK PubMed Central (United Kingdom)

BackgroundThe orphan nuclear receptor estrogen-related receptor α (ERRα) is a member of the nuclear receptor superfamily. It was identified through a search for genes...Full Text Available

26

Is there a benefit to sentinel lymph node biopsy in patients with T4 melanoma?  

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND: Controversy exists as to whether patients with thick (Breslow depth >4 mm), clinically lymph node-negative melanoma require sentinel lymph node (SLN) biopsy. The authors examined the impact of SLN biopsy on prognosis and outcome in this patient population. METHODS: A review of the authors institutional review board-approved melanoma database identified 293 patients with T4 melanoma who underwent surgical excision between 1998 and 2007. Patient demographics, histologic features, and outcome were recorded and analyzed. RESULTS: Of 227 T4 patients who had an SLN biopsy, 107 (47%) were positive. The strongest predictors of a positive SLN included angiolymphatic invasion, satellitosis, or ulceration of the primary tumor. Patients with a T4 melanoma and a negative SLN had a significa...

2009-01-01

27

Systemic combinatorial peptide selection yields a non-canonical iron-mimicry mechanism for targeting tumors in a mouse model of human glioblastoma  

UK PubMed Central (United Kingdom)

The management of CNS tumors is limited by the blood-brain barrier (BBB), a vascular interface that restricts the passage of most molecules from the blood into the brain. Here we show that phage particles...Full Text Available

2011-01-04

28

beta-Lactamases among extended-spectrum beta-lactamase (ESBL)-resistant Salmonella from poultry, poultry products and human patients in The Netherlands  

DEFF Research Database (Denmark)

Objectives: The purpose of this work was to study the genetic determinants responsible for extended-spectrum beta-lactamase (ESBL) resistance of Salmonella isolated from Dutch poultry, poultry meat and hospitalized humans. Methods: Thirty-four ESBL-resistant Salmonella isolates from The Netherlands were tested towards 21 antimicrobial agents. PCR and sequencing were used to determine the underlying genetic determinants responsible for the ESBL phenotypes. The transferability of the ESBL phenotypes was tested by conjugation to a susceptible Salmonella enterica serovar Dublin and plasmid purification, restriction fragment length polymorphism (RFLP) and pulsed-field gel electrophoresis (PFGE) were employed to further characterize a subset of the isolates. Results: A great genetic diversity was seen among the isolates. The bla(TEM-52) gene was most predominant and was found among Salmonella enterica serovars Blockley, Thomson, London, Enteritidis phage type 14b, ...

2005-01-01

29

Type IVB Secretion Systems of Legionella and Other Gram-Negative Bacteria  

UK PubMed Central (United Kingdom)

Type IV secretion systems (T4SSs) play a central role in the pathogenicity of many important pathogens, including Agrobacterium tumefaciens, Helicobacter pylori, and...Full Text Available

30

Silicates as Nonspecific Adsorbents of Bacteriophage: a Model for Purification of Water from Viruses  

UK PubMed Central (United Kingdom)

Amorphous silicates having small particles with a large surface area were found to have high nonspecific adsorption capacity. Investigations with Escherichia coli T4 bacteriophage have...Full Text Available

1980-01-01

31

Role of serum carrier proteins in the peripheral metabolism and tissue distribution of thyroid hormones in familial dysalbuminemic hyperthyroxinemia and congenital elevation of thyroxine-binding globulin.  

UK PubMed Central (United Kingdom)

To investigate the role of thyroxine-binding globulin (TBG) and albumin in the availability of thyroid hormones to peripheral tissues, comprehensive kinetic studies of thyroxine (T4) and triiodothyronine...Full Text Available

1987-08-01

32

Optimal bone strength and mineralization requires the type 2 iodothyronine deiodinase in osteoblasts  

UK PubMed Central (United Kingdom)

Hypothyroidism and thyrotoxicosis are each associated with an increased risk of fracture. Although thyroxine (T4) is the predominant circulating thyroid hormone, target cell responses are determined...Full Text Available

2010-04-20

33

Does amiodarone affect heart rate by inhibiting the intracellular generation of triiodothyronine from thyroxine?  

UK PubMed Central (United Kingdom)

The hypothesis that the antiarrhythmic drug amiodarone slows down the heart rate by its inhibitory action on the intracellular conversion of thyroxine (T4) to 3,5,3' triiodothyronine (T3) was investigated....Full Text Available

1984-05-01

34

Characterization of T-Even Bacteriophage Substructures  

UK PubMed Central (United Kingdom)

Tail plates obtained from T4D amber mutants were examined with respect to sedimentation behavior, subunit molecular weights, amino acid composition, isoelectric points, and morphology. Intact plates...Full Text Available

1970-10-01

35

Ultrastructure of the spermatozoon of the digenean Cricocephalus albus (Kuhl & van Hasselt, 1822) Looss, 1899 (Platyhelminthes, Pronocephaloidea, Pronocephalidae), parasite of ''the hawksbill sea turtle''Eretmochelys imbricata (Linnaeus, 1766) in Senegal  

British Library Electronic Table of Contents (United Kingdom)

The mature spermatozoon of Cricocephalus albus is filiform, tapered at both ends and shows the following features: 2 axonemes of different lengths presenting the 9+''1'' trepaxonematan pattern, 2 bundles of parallel cortical microtubules, a mitochondrion and a nucleus. Nevertheless, the particularity of the spermatozoon of C. albus is its anterior extremity with an apical electron-dense material associated with extramembranar ornamentation, a cytoplasmic dorsolateral expansion and spine-like bodies. To our knowledge, such an anterior extremity of the spermatozoon has not previously been described from a species of the superfamily Pronocephaloidea. Our study provides new data on the mature gamete of C. albus in order to improve our understanding of the pronocephaloidean phylogenetic relatio...

2011-01-01

36

Cloning of the cDNA and gene for a human D sub 2 dopamine receptor  

Energy Technology Data Exchange (ETDEWEB)

A clone encoding a human D{sub 2} dopamine receptor was isolated from a pituitary cDNA library and sequenced. The deduced protein sequence is 96% identical with that of the cloned rat receptor with one major difference: the human receptor contains an additional 29 amino acids in its putative third cytoplasmic loop. Southern blotting demonstrated the presence of only one human D{sub 2} receptor gene. Two overlapping phage containing the gene were isolated and characterized. DNA sequence analysis of these clones showed that the coding sequence is interrupted by six introns and that the additional amino acids present in the human pituitary receptor are encoded by a single exon of 87 base pairs. The involvement of this sequence in alternative splicing and its biological significance are discussed.

1989-12-01

37

Comparison of susceptibility to pitting corrosion of AA2024-T4, AA7075-T651 and AA7475-T761 aluminium alloys in neutral chloride solutions using electrochemical noise analysis  

Energy Technology Data Exchange (ETDEWEB)

The susceptibility to pitting corrosion of AA2024-T4, AA7075-T651 and AA7475-T761 aluminium alloys was investigated in aqueous neutral chloride solution for the purpose of comparison using electrochemical noise measurement. The experimentally measured electrochemical noises were analysed based upon the combined stochastic theory and shot-noise theory using the Weibull distribution function. From the occurrence of two linear regions on one Weibull probability plot, it was suggested that there existed two stochastic processes of uniform corrosion and pitting corrosion; pitting corrosion was distinguished from uniform corrosion in terms of the frequency of events in the stochastic analysis. Accordingly, the present analysis method allowed us to investigate pitting corrosion independently. The susceptibility to pitting corrosion was appropriately evaluated by determining pit embryo formation rate in the stochastic analysis. The susceptibility was ...

2008-01-15

38

Potentially pathogenic free-living amoebae isolated from hospital wards with immunodeficient patients in Tehran, Iran  

British Library Electronic Table of Contents (United Kingdom)

This study investigated the occurrence of free-living amoebae (FLA) in immunodeficiency wards of hospitals in Tehran, Iran. A total of 70 dust and biofilm samples from wards serving transplant, pediatric (malignancies), HIV, leukemia and oncology patients of five university hospitals were collected and examined for the presence of FLA using culturing and molecular approaches. Based on the morphology of the amoebae in plate cultures, primer sets were applied for molecular identification of Acanthamoeba, vahlkampfiid amoebae and Hartmannella. Out of 70 samples, 37 (52.9%) were positive for FLA. Acanthamoeba belonged to the T4 genotype was the most prevalent isolate. Presence of the T4 genotype on medical instruments, including an oxygen mask in an isolation room of an immunodeficiency pediat...

2011-01-01

39

No association between affective and behavioral dysregulation and parameters of thyroid function in youths  

British Library Electronic Table of Contents (United Kingdom)

Objective: Evidence from adults suggests that changes in thyroid function are associated with the development of bipolar disorder (BD) and severe mood dysregulation. A dysregulation profile based on the Child Behavior Checklist (CBCL-DP) describes a phenotype with severe mood problems in youth. The present study investigated whether altered thyroid functioning in youths is associated with the severe mood dysregulation symptoms characterized by the CBCL-DP. Methods: We analyzed the thyroid function data from 262 children and adolescents (n=262 for serum TSH, n=148 for free triiodothyronine [fT3] and n=153 for free thyroxine [fT4]) with their CBCL-DP composite score. We created and compared high CBCL-DP and low CBCL-DP subgroups with regard to their serum TSH, fT3 and fT4 concentrations as w...

2011-01-01

40

[Cloning of the gene for thermostable Thermus aquaticus YT1 DNA polymerase and its expression in Escherichia coli].  

Science.gov (United States)

Using the phasmid vector pSL5, the genomic DNA fragment of T. aquaticus YT1 which contained the thermostable DNA polymerase (Taq-polymerase) gene was cloned. The BglII fragment of this genome locus was subcloned in the BamHI site of the pUC19 plasmid. To optimize the Taq-polymerase gene expression in E. coli cells, the gene was cloned in the correct reading frame regarding the initiation ATG codon of the pPR-TGATG-1 expression vector. The gene expression in this vector was controlled by the phage lambda PR promoter and the temperature-sensitive phage lambda repressor. We used PCR to amplify the short 5'-end fragment of the Taq-polymerase gene coding for the part into which an artificial SacI site was introduced. This site has been used for cloning the PCR product into the pPR-TGATG-1 vector, and the missing gene part was cloned into the KpnI site of the PCR product from the natural cloned gene. The cells of the E. coli PVG-A1 strain, which was ...

 
 
 
 
41

Relative Rates of Transcapillary Movement of Free Thyroxine, Protein-Bound Thyroxine, Thyroxine-Binding Proteins, and Albumin  

UK PubMed Central (United Kingdom)

The rate of appearance of labeled thyroxine (T4) and albumin in lymph from various areas after simultaneous i.v. injection of the labeled substances in conscious ambulatory sheep has been used to estimate...Full Text Available

1974-07-01

42

Pa0148 from Pseudomonas aeruginosa Catalyzes the Deamination of Adenine.  

Science.gov (United States)

Four proteins from NCBI cog1816, previously annotated as adenosine deaminases, have been subjected to structural and functional characterization. Pa0148 (Pseudomonas aeruginosa PAO1), AAur1117 (Arthrobacter aurescens TC1), Sgx9403e, and Sgx9403g have been purified and their substrate profiles determined. Adenosine is not a substrate for any of these enzymes. All of these proteins will deaminate adenine to produce hypoxanthine with k(cat)/K(m) values that exceed 10(5) M(-1) s(-1). These enzymes will also accept 6-chloropurine, 6-methoxypurine, N-6-methyladenine, and 2,6-diaminopurine as alternate substrates. X-ray structures of Pa0148 and AAur1117 have been determined and reveal nearly identical distorted (?/?)(8) barrels with a single zinc ion that is characteristic of members of the amidohydrolase superfamily. Structures of Pa0148 with adenine, 6-chloropurine, and hypoxanthine were also determined, thereby permitting identification of the residues responsible for ...

2011-07-06

43

Evolution of a molecular switch: universal bacterial GTPases regulate ribosome function.  

Science.gov (United States)

The GTPases comprise a protein superfamily of highly conserved molecular switches adapted to many diverse functions. These proteins are found in all domains of life and often perform essential roles in fundamental cellular processes. Analysis of data from genome sequencing projects demonstrates that bacteria possess a core of 11 universally conserved GTPases (elongation factor G and Tu, initiation factor 2, LepA, Era, Obg, ThdF/TrmE, Ffh, FtsY, EngA and YchF). Investigations aimed at understanding the function of GTPases indicate that a second conserved feature of these proteins is that they elicit their function through interaction with RNA and/or ribosomes. An emerging concept suggests that the 11 universal GTPases are either necessary for ribosome function or transmitting information from the ribosome to downstream targets for the purpose of generating specific cellular responses. Furthermore, it is suggested that progenitor GTPases were early regulators of RNA ...

2001-07-01

44

Cloning and sequencing of cDNA encoding human DNA topoisomerase II and localization of the gene to chromosome region 17q21-22  

Energy Technology Data Exchange (ETDEWEB)

Two overlapping cDNA clones encoding human DNA topoisomerase II were identified by two independent methods. In one, a human cDNA library in phage {lambda} was screened by hybridization with a mixed oligonucleotide probe encoding a stretch of seven amino acids found in yeast and Drosophila DNA topoisomerase II; in the other, a different human cDNA library in a {lambda}gt11 expression vector was screened for the expression of antigenic determinants that are recognized by rabbit antibodies specific to human DNA topoisomerase II. The entire coding sequences of the human DNA topoisomerase II gene were determined from these and several additional clones, identified through the use of the cloned human TOP2 gene sequences as probes. Hybridization between the cloned sequences and mRNA and genomic DNA indicates that the human enzyme is encoded by a single-copy gene. The location of the gene was mapped to chromosome 17q21-22 by in situ hybridization of a cloned fragment to ...

1988-10-01

45

Analysis of forward mutations induced by N-methyl-N'-nitro-N-nitrosoguanidine in the bacteriophage P22 mnt repressor gene  

Energy Technology Data Exchange (ETDEWEB)

We describe the isolation and genetic characterization of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutations in the phage P22 mnt repressor gene cloned in plasmid pBR322. Mutations in the mnt repressor gene or its operator on this plasmid, pPY98, confer a tetracycline resistance phenotype, whereas the wild-type plasmid confers tetracycline sensitivity. Cells carrying pPY98 were briefly exposed to MNNG to give 20 to 40% survival and a 50- to 100-fold increase in tetracycline-resistant cells. DNA sequence analysis showed that 29 to 30 MNNG-induced mutations were GC-to-AT transitions and one was an AT-to-GC transition. About 80% of the mutations are in three hotspots. This mutation spectrum is consistent with the proposed mechanism of mutagenic action of MNNG, which involves mispairing of an alkylated base, O/sup 6/-methylguanine. The mnt gene may be a useful target for determining mutagenic specificity at the nucleotide level because (i) forward ...

1986-04-01

46

Isothermal, total strain-controlled cyclic deformation of GGG-60 at temperatures of 20 C {<=}T {<=}500 C. Pt. 1; Isotherme totaldehnungskontrollierte Wechselverformung von GGG-60 im Temperaturbereich 20 C {<=}T {<=}500 C. T. 1  

Energy Technology Data Exchange (ETDEWEB)

The paper examines the influence of various total strain amplitudes and mean strains on the cyclic deformation processes in GGG-60 at temperatures of 20 C, 350 C, and 500 C ,the total strain amplitudes being varied between 1.0 permille {<=}{epsilon}{sub a,t}{<=}3.8 permille , and the mean strains between -4.0 permille {<=}{epsilon}{sub m,t}{<=}4.0 permille . - [Deutsch] In der Arbeit wird der Einfluss unterschiedlicher Totaldehnungsamplituden und Mitteldehnungen auf das Wechselverformungsverhalten von GGG-60 bei Temperaturen von 20 C, 350 C und 500 C untersucht. Dabei werden die Totaldehnungsamplituden zwischen 1,0 permille {<=} {epsilon}{sub a,t} {<=} 3,8 permille und die Mitteldehnungen zwischen -4,0 permille {<=} {epsilon}{sub m,t} {<=} 4,0 permille variiert. (orig./MM)

1995-01-01

47

W_3-algebra constructed from the SU(3) parafermion  

International Nuclear Information System (INIS)

A construction of a W_3-algebra for the SU(3) parafermion is proposed. The details of the calculation are given, in which the Z-algebra technique is used instead of the popular free field realization. We find that the W_3-algebra is closed at level k=3, and the central charge of the underlying algebra is different from known series of Fateev-Lykyanov W-algebras; as a by-product we get a field T"("4")(z), whose conformal dimension is 4, and is null at k=3. ((orig.)).

8730-01-01

48

Simulation of DNA electrophoresis through microstructures  

British Library Electronic Table of Contents (United Kingdom)

The dependence of the mobility of DNA molecules through an hexagonal array of micropillars on their length and the applied electric field was investigated and it was found that mobility is a nonmonotonic function of their length. Results also revealed that the size dependence of the DNA mobility depends on the applied electric field and there is a crossover around E 25 V/cm for the mobility of l-DNA and T4-DNA. These observations are explained in terms of the diffusion process inside the structure affected by the solvent and are modeled using the Langevin and its corresponding Fokker-Planck equations. The phenomenon is generalized under three regimes in a phase diagram relating the electric field and the DNA lengths. The model and the associated phase diagram described here provide an expl...

2007-01-01

49

S-matrix elements and covariant tachyon action in type 0 theory  

Energy Technology Data Exchange (ETDEWEB)

We evaluate the sphere level S-matrix element of two tachyons and two massless NS states, the S-matrix element of four tachyons, and the S-matrix element of two tachyons and two Ramond-Ramond vertex operators, in type 0 theory. We then find an expansion for theses amplitudes that their leading order terms correspond to a covariant tachyon action. To the order considered, there are no T4, T2(-bar T)2, T2H2, nor T2R tachyon couplings, whereas, the tachyon couplings FF-bar T and T2F2 are non-zero.

2005-01-17

50

In vitro and in vivo activities of T4 endonuclease V mutants altered in the C-terminal aromatic region  

International Nuclear Information System (INIS)

Genes encoding mutants of the thymine photodimer repair enzyme from bacteriophage T4 (T4 endonuclease V) having an amino acid substitution (T127M, W128A, W128S, Y129A, K130L, Y131A, Y132A) were constructed by use of a previously obtained synthetic gene and expressed in Escherichia coli under the control of the E. coli tryptophan promoter. An in vitro assay of partially fractionated mutant proteins for glycosylase activity was performed with chemically synthesized substrates containing a thymine photodimer. T127M and K130L showed almost the same activity as the wild-type protein. Although W128S, Y131A, and Y132A were slightly active, W128A and Y129A lost activity. The results indicated that the aromatic amino acids around position 130 may be important for the glycosylase activity. Mutant T127M was purified, and the Km value was found to be of the same order as that of the wild type (10(-8) M). In vivo ...

51

Effects of perinatal exposure to low doses of cadmium or methylmercury on thyroid hormone metabolism in metallothionein-deficient mouse neonates  

International Nuclear Information System (INIS)

Perinatal exposure to cadmium (Cd) or methylmercury (MeHg) results in impaired neurodevelopment. Thyroid hormone is essential for normal brain development. However, the issue whether Cd or MeHg, especially at low doses, interrupts thyroid hormone action remains to be investigated. In the present study, effects of perinatal exposure to low levels of Cd or MeHg on thyroid hormone metabolism were examined using metallothionein I and II (MT-I/II) null or wild-type neonatal mice. Dams were exposed to 10 mg/L water of Cd or 5 mg/kg chow of MeHg from gestational day 0 to post-natal day 10 (PND 10). Sera, livers and brains were collected from neonates on PND 10. Iodothyronine deiodinase activities and serum thyroxine (T4) concentrations were measured. MeHg exposure failed to induce changes in serum T4 levels and liver type 1 deiodinase (D1) and brain type 2 deiodinase (D2) activities regardless of the MT ...

2006-11-10

52

The p75"N"T"R tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells  

International Nuclear Information System (INIS)

The p75 neurotrophin receptor (p75"N"T"R) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75"N"T"R retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted (#DELTA#DD) dominant-negative antagonist of p75"N"T"R showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75"N"T"R-dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the prostate cancer cells. Apoptosis of p75"N"T"R expressing cells occurred via the intrinsic mitochondrial pathway leading to a sequential caspase-9 and ...

2006-03-24

53

Potent, selective and cell penetrant inhibitors of SF-1 by functional ultra-high-throughput screening.  

Science.gov (United States)

The steroidogenic factor 1 (SF-1, also known as NR5A1) is a transcription factor belonging to the nuclear receptor superfamily. Whereas most of the members of this family have been extensively characterized, the therapeutic potential and pharmacology of SF-1 still remains elusive. Described here is the identification and characterization of selective inhibitory chemical probes of SF-1 by a rational ultra-high-throughput screening (uHTS) strategy. A set of 64,908 compounds from the National Institute of Health's Molecular Libraries Small Molecule Repository was screened in a transactivation cell-based assay employing a chimeric SF-1 construct. Two analogous isoquinolinones, ethyl 2-[2-[2-(2,3-dihydro-1,4-benzodioxin-7-ylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate (SID7969543) and ethyl 2-[2-[2-(1,3-benzodioxol-5-ylmethylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate and (SID7970631), were identified as potent submicromolar inhibitors, yielding ...

2008-03-11

54

Tachyons in gravitational field  

International Nuclear Information System (INIS)

Behaviour of tachyons in gravitational field has been investigated by using imaginary as well as real superluminal Lorentz transformations. Using real superluminal transformations in four- and six-dimensional space-time, an expression for the gravitational force acting on a tachyon, moving along the tachyon corridor constructed to follow the tachyon geodesic, has been derived. The motion of a tachyon through a black hole has also been discussed and it is shown that the black hole acts like a gravitational tunnel for tachyons and the transition between the regions inside and outside the horizon can be understood as real superluminal transformations transforming a R"4=(r,t) world into a T"4=(t,r) world. 36 refs.. (author).

55

Synthesis of N-(3-azido-4-chlorophenyl)-N'-["3H-methyl] thiourea, an efficient photoaffinity probe for the urea carrier  

International Nuclear Information System (INIS)

Starting from commercial 4-chloro-3-nitroaniline, through a 5 step synthesis, 3-azido-4-chlorophenylisothiocyanate was prepared and reacted with ["3H]-methylamine. The latter was obtained by three methods: (i) ["3H]-LiA1T_4 reduction of benzylcarbamate gave rise to ["3H]-methylamine (S.A.: > 70 Ci/mmol). (ii) Catalytic reduction of HCN with "3H_2 lead to ["3H]-CH_3NH_2 (S.A.: 0.7 Ci/mmol). (III) Schmidt rearrangement of ["3H]-sodium acetate gave ["3H]-CH_3NH_2 (S.A.: 29 Ci/mmol). (author).

56

Nerve-Evoked Constriction of Rat Tail Veins Is Potentiated and Venous Diameter Is Reduced after Chronic Spinal Cord Transection  

British Library Electronic Table of Contents (United Kingdom)

Abstract Despite reduced sympathetic activity below the level of a spinal cord injury (SCI), venoconstriction during autonomic dysreflexia increases venous return to the heart. Here, contractions of isometrically mounted tail veins from rats with spinal transection at T4 performed 8???10 weeks earlier are compared with those from sham-operated rats. After SCI, lumen diameter was reduced by ?30% and the contractions evoked by electrical stimulation of the perivascular axons were larger than control. This augmentation of neurovascular transmission was not associated with enhanced sensitivity to ?-adrenoceptor agonists or to adenosine-5?-triphosphate (ATP) although contractions to depolarization with K+ were larger after SCI. The percentage reduction in nerve-evoked contraction after SCI prod...

2011-01-01

57

Identification and staging of bladder carcinoma  

International Nuclear Information System (INIS)

The purpose of the present study was to compare the effectiveness of MRI, CT and radioimmunoscintigraphy in the staging and detection of bladder cancers in 28 patients. We distinguish two groups: Group I included the tumour stages CIS-T_3_A and the second group the deep infiltrative tumours T_3_B-T_4. MRI was slightly superior to CT in respect of tumour staging (75% correct results as compared to 63%). No understaging occurred with MRI, whereas in 22% of the cases the stage of the tumour was underestimated using CT diagnostics. Overstaging occurred in 25% of the MRI and 15% of the CT-diagnostics, respectively. RIS cannot distinguish the tumour groups, and hence this method is useful only for the detection of the primary tumour and metastases. In 77% of cases the tumour was detected and in 15% the tumour could be safely excluded. (orig.).

58

Effects of pork/beef levels and various casings on quality properties of semi-dried jerky  

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to investigate the effects of pork/beef levels and the casings on the quality properties of semi-dried jerky. The pork/beef levels in the four test formulations were as follows: T-1 (pork: beef=100:0), T-2 (95:5), T-3 (90:10), and T-4 (80:20). After tumbling for 30min with curing solution, the cured meats were stuffed into natural sheep casings, collagen casings, or cellulose casings, and then dried. The restructured jerky with cellulose casing had the lowest water content and the highest protein content, with no significant differences between various formulations. There were no significant differences among all formulations with regard to pH and total microbial counts, and jerky with cellulose casing had the lowest value of water activity. The processing yields ...

2008-01-01

59

Genome analysis of F. nucleatum sub spp vincentii and its comparison with the genome of F. nucleatum ATCC 25586.  

Science.gov (United States)

We present the draft genome sequence and its analysis for Fusobacterium nucleatum sub spp. vincentii (FNV), and compare that genome with F. nucleatum ATCC 25586 (FN). A total of 441 FNV open reading frames (ORFs) with no orthologs in FN have been identified. Of these, 118 ORFs have no known function and are unique to FNV, whereas 323 ORFs have functional orthologs in other organisms. In addition to the excretion of butyrate, H2S and ammonia-like FN, FNV has the additional capability to excrete lactate and aminobutyrate. Unlike FN, FNV is likely to incorporate galactopyranose, galacturonate, and sialic acid into its O-antigen. It appears to transport ferrous iron by an anaerobic ferrous transporter. Genes for eukaryotic type serine/threonine kinase and phosphatase, transpeptidase E-transglycosylase Pbp1A are found in FNV but not in FN. Unique ABC transporters, cryptic phages, and three types of restriction-modification systems have been identified in FNV. ORFs for ...

2003-06-01

60

Cloning of Drosophila transcription factor Adf-1 reveals homology to Myb oncoproteins.  

Science.gov (United States)

The Drosophila sequence-specific DNA binding protein, Adf-1, is capable of activating transcription of the alcohol dehydrogenase gene, Adh, and is implicated in the transcriptional control of other developmentally regulated genes. We have cloned the cDNA encoding Adf-1 by generating specific DNA probes deduced from partial amino acid sequence of the protein. Several cDNA clones encoding an extended open reading frame were isolated from a phage lambda library. The complete amino acid sequence of Adf-1 deduced from the longest cDNA reveals structural similarities to the putative helix-turn-helix DNA binding motif of Myb and Myb-related proteins. DNA sequence analysis of genomic clones and Northern blot analysis of mRNA suggest that Adf-1 is a single-copy gene encoding a 1.9-kb transcript. Purified recombinant Adf-1 expressed in Escherichia coli binds specifically to Adf-1 recognition sites and activates transcription of a synthetic Adh promoter in vitro in a manner ...

1992-01-15

 
 
 
 
61

Alteration of nucleoside diphosphate binding specificity of E. coli elongation factor Tu (EF-Tu) by single amino acid substitution at position 138  

International Nuclear Information System (INIS)

A single amino acid substitution (Asp #-># Asn) at position 138 of E. coli EF-Tu was induced in the tufA gene by an M13 phage oligonucleotide site-directed mutagenesis protocol. The mutated tufA gene was then subcloned in a plasmid vector and expressed in maxicells. The properties of ["3"5S]methionine labelled mutant and wild type EF-Tu's were compared by in vitro assays. Mutant and wild-type EF-Tu's bound EF-Ts with approximately equal affinities. The 138-Asn mutation greatly reduced the protein's affinity for GDP; however, this mutation dramatically increased the proteins affinity for XDP. The mutant protein forms a stable complex with phe-tRNA and XTP, which binds to ribosomes; whereas, it does not form a complex with phe-tRNA and GTP. These results suggest that in EF-Tu x NDP complexes amino acid residue 138 must interact with the substituent on C-2 of the purine ring. Thus in wild-type EF-Tu Asp-138 would H-bond to 2-NH_2 of GDP, and in the mutant EF-Tu ...

1987-06-07

62

On the cells of origin of radiogenic thyroid cancer: New studies based on an old idea  

Energy Technology Data Exchange (ETDEWEB)

We have presented evidence that the functional thyroid follicles (follicular units, FU) which are formed in grafts of monodispersed rat thyroid cells, and hence the thyroid tumors which later develop in such grafts, are clonal in origin. Recent studies have been designed to investigate: whether cell number-dependent inhibition of promotion-progression is mediated by remote hormonal feed-back, local cell-cell interactions, or both; the cell population kinetics of the clonogen subpopulation during goitrogenesis and goiter involution; and the effect of prolonged exposure to high levels of TSH (thyrotropin) on the capacity of the clonogens to give rise to functional FU. The results indicate that local cell-cell interactions play an important role in the cell number-dependent suppression of neoplastic promotion-progression. They also show that if sufficient thyroid cells are grafted, the thyroid-pituitary axis can be reestablished in thyroidectomized rats fed normal diets. In such animals ...

1990-01-01

63

String Junctions and Holographic Interfaces  

CERN Document Server

In this paper we study half-BPS type IIB supergravity solutions with multiple $AdS_3\\times S^3\\times M_4$ asymptotic regions, where $M_4$ is either $T^4$ or $K_3$. These solutions were first constructed in [1] and have geometries given by the warped product of $AdS_2 \\times S^2 \\times M_4 $ over $\\Sigma$, where $\\Sigma$ is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. $n$ half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [1] are constructed introducing two meromorphic and two harmonic functions defined on $\\Sigma$. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the ...

2010-01-01

64

Monovalent cation-induced structure of telomeric DNA: The G-quartet model  

Energy Technology Data Exchange (ETDEWEB)

We have investigated the structures formed by oligonucleotides composed of two or four repeats of the telomeric sequences from Oxytricha and Tetrahymena. The Oxytricha four-repeat molecule (d(T4G4)4 = Oxy-4) forms structures with increased electrophoretic mobility in nondenaturing gels containing Na+, K+, or Cs+, but not in gels containing Li+ or no added salt. Formation of the folded structure results in protection of a set of dG's from methylation by dimethyl sulfate. Efficient UV-induced cross-links are observed in Oxy-4 and the related sequence from Tetrahymena (d(T2G4)4 = Tet-4), and join thymidine residues in different repeats. Models proposed to account for these data involve G-quartets, hydrogen-bonded structures formed from four guanosine residues in a square-planar array. We propose that the G-quartet structure must be dealt with in vivo by the telomere replication machinery.

1989-12-01

65

Magnetic resonance imaging: early detection of central nervous system involvement in acquired immunodeficiency syndrome (AIDS)  

International Nuclear Information System (INIS)

Central Nervous System (CNS) involvement, whether primary by the Human Immunodeficiency Virus - HIV - itself, or secondary (toxoplasmosis or lymphoma) is remarkably frequent in AIDS, in 40 to 70% of cases, depending upon the author. In order to study the natural history of this illness, a cohort of 25 asymptomatic seropositive patients have been established. Every 6 months these patients undergo biological and clinical examinations, as well as Magnetic Resonance brain scans. After two examinations at a 6 month's interval, the first results are reported. Out of these 25 cases, 9 present anomalies: One patient with diffuse cerebral atrophy and 8 others with high signal intensity areas on T2 weighted sequences, like those of the Multiple Sclerosis. No relationship could be demonstrated between the existence of these lesions and various criteria such as age, sex, risk factors and T4 cells count. The nature of these lesions is not lear. They ...

66

Hypothalmic hypopituitarism following cranial irradiation for nasopharyngeal carcinoma  

Energy Technology Data Exchange (ETDEWEB)

Eight patients, one male and seven females, with no pre-existing hypothalamic-pituitary disease, who developed symptoms of hypopituitarism following cranial irradiation for nasopharyngeal carcinoma were studied 5 years or more after radiotherapy. All were GH deficient. Four of the patients with no GH response during insulin tolerance tests (ITT) showed increased GH in response to synthetic human growth hormone releasing factor (GRF-44). Four patients had impaired cortisol responses to ITT, and gradual but diminished cortisol responses to ovine corticotrophin releasing factor (CRF-41). There was no significant difference between mean peak increments in response to ITT and those in response to CRF-41. TSH responses to TRH were delayed in five and absent in two patients; four of these had low free T4 index. Prolactin was raised in all seven women and increased further in response to TRH. Two patients had impaired gonadotrophin responses to LHRH. ...

1986-06-01

67

Assessment of oral toxicity and safety of pentamethylchromanol (PMCol), a potential chemopreventative agent, in rats and dogs  

British Library Electronic Table of Contents (United Kingdom)

2,2,5,7,8-Pentamethyl-6-chromanol (PMCol) was administered by gavage in rats for 28 days at dose levels of 0, 100, 500, and 2000mg/kg/day. PMCol administration induced decreases in body weight gains and food consumption, hepatotoxicity (increased TBILI, ALB, ALT, TP; increased relative liver weights; increased T4 and TSH), nephrotoxicity (increased BUN and BUN/CREAT, histopathology lesions), effect on lipid metabolism (increased CHOL), anemia, increase in WBC counts (total and differential), coagulation (FBGNand PTdarr) and hyperkeratosis of the nonglandular stomach in the 2000mg/kg/day dose group (in one or both sexes). In the 500mg/kg/day dose group, toxicity was seen to a lesser extent. In the 100mg/kg/day dose group, only increased CHOL (females) was observed. To assess the toxicity of...

2010-01-01

68

Analytic modelling of tidal effects in the relativistic inspiral of binary neutron stars  

CERN Document Server

To detect the gravitational-wave signal from binary neutron stars and extract information about the equation of state of matter at nuclear density, it is necessary to match the signal with a bank of accurate templates. We have performed the longest (to date) general-relativistic simulations of binary neutron stars with different compactnesses and used them to constrain a tidal extension of the effective-one-body model so that it reproduces the numerical waveforms accurately and essentially up to the merger. The typical errors in the phase over the $\\simeq 22$ gravitational-wave cycles are $\\Delta \\phi\\simeq \\pm 0.24$ rad, thus with relative phase errors $\\Delta \\phi/\\phi \\simeq 0.2%$. We also show that with a single choice of parameters, the effective-one-body approach is able to reproduce all of the numerically-computed phase evolutions, in contrast with what found when adopting a tidally corrected post-Newtonian Taylor-T4 expansion.

2010-01-01

69

2000-centiGray total lymphoid irradiation for refractory rheumatoid arthritis  

International Nuclear Information System (INIS)

Because toxicity with the use of 3000 centiGray (cGy) of total lymphoid irradiation (TLI) was observed in an earlier study, 2000-cGy treatments were delivered in a 2-portal format to 7 patients and in a modified 3-portal fashion to 6 patients, as part of a randomized, investigator-blinded trial of TLI treatment for refractory rheumatoid arthritis. Analysis of combined data from the 13 patients revealed statistically significant improvement in 5 clinical indicators of disease activity at the end of TLI and 6 and 12 months later, accompanied by T4-specific immunosuppression. Management considerations resulted in the introduction of prednisone therapy in 5 patients, methotrexate in 4, and azathioprine in 1 during the interval of 8-12 months post-TLI. Herpes zoster occurred in 5 patients prior to the initiation of this additional therapy. These data indicate that, in patients with rheumatoid arthritis, a TLI dose of 2000 cGy is sufficient to ...

70

Use of sewage sludge and coconut coir mix as a peat substitute for potted chrysanthemum  

Energy Technology Data Exchange (ETDEWEB)

Recent central processing of domestic wastewater in Malaysia has initiated investigations into the disposal/utilization of the sewage sludge produced. We had conducted an experiment to investigate the feasibility of using dewatered sewage sludge and coconut coir as a peat substitute in a potting medium for chrysanthemum. The experiment involved 9 treatments with sewage sludge (SS) and coconut coir (CC) mixed in different ratios (v/v) to replace peat in the standard potting medium of 3:2:1 (soil: peat: sand).The potting medium contained the following treatments, T1: peat + recommended rates of Agroblend (Ag), a slow release fertilizer, and Grofas (Gf), a foliar fertilizer (commonly used medium and fertilization), T2: [1SS:1CC] + Ag, T3: [1SS:1CC] + half recommended rates of Agroblend and Grofas (1/2Ag + 1/2Gf), T4: [2SS:1CC] + Ag, T5: [2SS:1CC] + 1/2Ag + 1/2Gf, T6: [3SS:1CC] + Ag, T7: [3SS:1CC] + 1/2Ag + 1/2Gf, T8: [4SS:1CC] + Ag, and T9: ...

2003-07-01

71

Screening for congenital hypothyroidism in Lebanon - An example of newborn screening in absence of mandatory law  

International Nuclear Information System (INIS)

This paper presents a group's efforts to introduce national newborn screening in Lebanon. Tandem mass spectrometry (MS) technology offers the prospect of utilizing filter paper blood specimens to screen newborns for several metabolic disorders. In order to be cost-effective, it is necessary to have a mandatory newborn screening policy. At present such a policy is not available in Lebanon. A national screening survey for congenital hypothyroidism (CH) was carried out to assess the incidence of this anomaly in the Lebanese population. Such an initiative is essential as a first step for assessing the feasibility and cost of a national screening programme. Coated beads, blood spot standards for quality control and buffer solutions used for assays were prepared in-house to minimize costs. At first, samples of umbilical cord blood spots were assayed for TSH using IRMA technique. Those samples showing borderline or high values of TSH were then assayed for total ...

2004-10-01

72

Results of electron beam therapy using intra-oral cone for carcinoma of the oral tongue  

Energy Technology Data Exchange (ETDEWEB)

Retrospective analyses were performed to evaluate the therapeutic efficacy of intra-oral cone (IOC) radiation therapy for carcinoma of the oral tongue, especially about its faculty of local control and complications. Thirty-nine patients with squamous cell carcinoma of the oral tongue were treated with IOC radiation therapy alone or in combination with external irradiation. IOC radiation therapy was given not only for T1 and T2, but also for T3 tumors. Hypofractionation was used for IOC radiation therapy. The 2 year local control rates, including surgical salvage, for T1, T2, T3 and T4 were 100%, 73.3%, 40% and 0%, respectively. The 5 year actuarial survival rates for Stage I, II, III and IV were 100%, 65.3%, 35.4% and 0%, respectively. The incidences of radiation complications, i.e. soft tissue ulceration and osteoradionecrosis, were 42.9% and 2.9%, respectively. It is suggested that relatively high rate of soft tissue ulceration was due to ...

1992-07-01

73

High mobility two-dimensional hole system in GaAs/AlGaAs quantum wells grown on (100) GaAs substrates  

International Nuclear Information System (INIS)

We report on the transport properties of a high mobility two-dimensional hole system (2DHS) confined in GaAs/AlGaAs quantum wells grown by molecular-beam epitaxy on the (100) surface of GaAs. The quantum wells are modulation doped with carbon utilizing a resistive filament source. At T=0.3 K and carrier density p=1x10"1"1 cm"-"2, a mobility of 10"6 cm"2/Vs is achieved. At fixed carrier density p=10"1"1 cm"-"2, the mobility is found to be a nonmonotonic function of the quantum well width. The mobility peaks at 10"6 cm"2/Vs for a 15-nm well and is reduced for both smaller and larger well widths for these (100) samples. The mobility anisotropy is found to be small. Mobility along [011] is approximately 20% higher than along the [011] direction. In addition, the low-temperature carrier density is found to have low sensitivity to light. The hole density increases by only #approx#10% after exposure to red light at T=4.2 K. In structures designed for ...

2005-04-18

74

Edge biasing in the WEGA stellarator  

Energy Technology Data Exchange (ETDEWEB)

The WEGA stellarator is used to confine low temperature, overdense (densities exceeding the cut-off density of the heating wave) plasmas by magnetic fields in the range of B=50-500 mT. Microwave heating systems are used to ignite gas discharges using hydrogen, helium, neon or argon as working gases. The produced plasmas have been analyzed using Langmuir and emissive probes, a single-channel interferometer and ultra-high resolution Doppler spectroscopy. For a typical argon discharge in the low field operation, B=56 mT, the maximum electron density is n{sub e}{proportional_to}10{sup 18} m{sup -3} with temperatures in the range of T=4-12 eV. The plasma parameters are determined by using Langmuir probes and are cross-checked with interferometry. It is demonstrated within this work that the joint use of emissive probes and ultra-high resolution Doppler spectroscopy allows a precise measurement of the radial electric field. The focus of this work is ...

2009-02-27

75

Comparative removal of pyrimidine dimers from human epidermal keratinocytes in vivo and in vitro  

Energy Technology Data Exchange (ETDEWEB)

We have compared the kinetics for repair of UV-induced cyclobutane pyrimidine dimers in the DNA of keratinocytes in human skin and in cell culture. A small area of the buttocks of volunteers was exposed to UVB-irradiation and biopsies were taken at various time intervals. Epidermal keratinocytes in culture from the same subjects were exposed to UVC with doses chosen to elicit comparable yields of dimers in cellular DNA. The initial density of pyrimidine dimers and the kinetics of their removal were assessed utilizing the dimer-specific T4 endonuclease V and sedimentation of the unlabeled DNA through alkaline sucrose gradients. The position of DNA in the gradients was determined using a monoclonal antibody against random sequences of single-stranded DNA in a sensitive immunoassay. The initial dimer frequency was 3.9-6.7 per 10(8) daltons DNA. About 40% of the dimers were removed within 1 h, 70% in 6 h, and 90% in 24 h for both in vivo and in ...

1988-10-01

76

Comparative removal of pyrimidine dimers from human epidermal keratinocytes in vivo and in vitro  

International Nuclear Information System (INIS)

We have compared the kinetics for repair of UV-induced cyclobutane pyrimidine dimers in the DNA of keratinocytes in human skin and in cell culture. A small area of the buttocks of volunteers was exposed to UVB-irradiation and biopsies were taken at various time intervals. Epidermal keratinocytes in culture from the same subjects were exposed to UVC with doses chosen to elicit comparable yields of dimers in cellular DNA. The initial density of pyrimidine dimers and the kinetics of their removal were assessed utilizing the dimer-specific T4 endonuclease V and sedimentation of the unlabeled DNA through alkaline sucrose gradients. The position of DNA in the gradients was determined using a monoclonal antibody against random sequences of single-stranded DNA in a sensitive immunoassay. The initial dimer frequency was 3.9-6.7 per 10(8) daltons DNA. About 40% of the dimers were removed within 1 h, 70% in 6 h, and 90% in 24 h for both in vivo and in ...

1988-01-01

77

Influence of a combination of two tetrachlorobiphenyl congeners (PCB 47; PCB 77) on thyroid status, choline acetyltransferase (ChAT) activity, and short- and long-term memory in 30-day-old Sprague-Dawley rats  

International Nuclear Information System (INIS)

The important role of thyroid hormones in growth and development, maintenance of body temperature, digestion, cardiac function, and normal brain development can be disrupted by environmental contaminants like polychlorinated biphenyls (PCB). Polychlorinated biphenyls are environmental contaminants that are widespread, persistent, lipophilic, and bioaccumulate through food webs, concentrating in adipose tissue. Placental and lactational PCB exposure of offspring causes metabolic and endocrine disruptions including hypothyroxinemia, spatial learning and memory deficits, neurochemical and neurobehavioral alterations, and reproductive problems. Previous studies in our lab using the individual congeners PCB 47 (2,2',4,4'-tetrachlorobiphenyl, ortho-substituted) and PCB 77 (3,3',4,4'-tetrachlorobiphenyl, non-ortho-substituted) have demonstrated alterations in thyroid hormone levels, alterations in brain choline acetyltransferase (ChAT) activity, and spatial learning deficits. In the present ...

2004-10-15

78

Squamous cell carcinoma of the oropharynx: Ki-67 and p53 can identify patients at high risk for local recurrence after surgery and postoperative radiotherapy  

International Nuclear Information System (INIS)

Purpose: To assess the prognostic value of biologic (p53, Ki-67) and clinical factors in squamous cell carcinoma of the oropharynx after radical surgery and postoperative radiotherapy (RT). Methods and Materials: Between 1985 and 1995, a total of 102 patients with 104 tumor sites were entered onto the study. Fifty-five primary tumors (53%) involved the tonsils, 26 (25%) the soft palate, and 23 (22%) the base of the tongue. Median age was 53 years (range 36-80 years). The clinical T- and N-categories (UICC 1997) were: T1 (30), T2 (47), T3 (22), T4 (5), N0 (33), N1 (28), N2 (42), and N3 (1). Histologically-clear margins were achieved in all patients by initial surgery. Postoperative RT to the primary and regional lymphatics was given, to a total of 60 Gy in 6 weeks, and single daily fractions of 2 Gy. The expression of the nuclear p53- and Ki-67-labeling index (LI) was investigated by immunostaining using the monoclonal antibodies DO-7 and MIB 1. ...

2000-11-01