1,980 research outputs found

    Antigenic modulation of mammary tumour virus envelope antigen or GR thymic lymphoma cells in relation to expressions of H-2, TL cell-surface antigens and THY1.

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    The MLr antigen, a mammary tumour virus-induced antigen on the surface of GR thymic lymphoma cells (GRSL) can be modulated from the cell surface upon incubation with specific antiserum for 1-2 h at 37 degrees C, followed by washing the cells. In contrast, a number of other cell-surface antigens on these GRSL cells cannot be modulated under similar conditions. These antigens include histocompatibility antigens of the H-2 complex (H-2.8 of the K-end and H-2dx(D) of the H-2dx haplotype) and two thymic markers, TL1.2 and Thy1.2. Antigenic modulation of MLr as tested by trypan-blue exclusion and by chromium51 release does not lead to a measurable change in the expression of H-2K, H-2D, TL and Thy1.2 antigens. These results could be confirmed by absorption analysis. The latter analysis showed that the number of antigenic sites per cell are about the same for MLr and the two H-2 antigens, while TL antigens are scarcer and Thy1.2 antigens are more abundant. The procedure of antigenic modulation showed that the MLr antigen resides on MTVgp52, the major protein of the envelope. There was no evidence of internal proteins, such as MTVp27, on the surface of GRSL cells

    Oral human papillomavirus (HPV) infection in men who have sex with men: prevalence and lack of anogenital concordance.

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    To estimate the prevalence of oral detectable human papillomavirus (HPV) DNA in HIV-negative men who have sex with men (MSM) attending a sexual health clinic in London and concordance with anogenital HPV infection. Such data are important to improve our understanding of the epidemiology of oral HPV and the potential use of vaccines to prevent oropharyngeal cancers

    Signalparameter zur Ortung von HPEM-Quellen

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    In diesem Beitrag wird anhand von Signalproben untersucht, mit welchen geeigneten Signalparametern die Ortung von aktiven leistungsstarken elektromagnetischen Quellen (sog. HPEM-Quellen) optimal durchgeführt werden kann. Da sich die Positionsberechnung durch die Verarbeitung von Laufzeitdifferenzen ergibt, beschränkt sich die Untersuchung auf die Bestimmung der Laufzeitdifferenzen. Betrachtet werden sowohl Signalausschnitte definierter Länge sowie eindeutig identifizierbare Ereigniszeitpunkte. Im ersten Fall werden aus der Korrelation der Signalausschnitte im Frequenzbereich die Laufzeitdifferenzen bestimmt. Hierbei wird durch Variation der Anzahl der Abtastwerte eines Signalausschnitts die erforderliche Signaldauer ermittelt. Im zweiten Fall werden zuerst aus den direkt erfassten Signaldaten die Einhüllenden gewonnen. Bezüglich eines vordefinierten Referenzwertes werden diese Einhüllenden dann korrigiert. Mit Hilfe eines festgelegten Schwellwertes wird abschließend aus den korrigierten Hüllkurven die Differenz der Ereigniszeitpunkte gebildet und somit die Laufzeitdifferenz im Zeitbereich bestimmt

    AFM studies of surface morphologies of sputtered SrTiO<sub>3</sub> films and annealed MgO substrates

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    Atomic force microscopy (AFM) is applied to study the surface morphologies and growth mechanisms of sputtered SrTiO3 films on single-crystal MgO(100) substrates. Meanwhile, surface morphologies of as-polished and post-annealed MgO(100) substrates are investigated as well. Effects of the miscut (or misorientation) of the substrate surface on morphologies and growth mechanisms are discussed. For comparison, a typical surface morphology and growth mechanism of the spiral island structure in sputtered PrBa2Cu3O7-δ films on MgO(100) substrates are presented

    Tres nuevas especies de killis (Cyprinodontiformes: Nothobranchiidae) de Guinea Ecuatorial

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    Two new Mesoaphyosemion species and one new species of the ’Aphyosemion’ herzogi group are described from the inland of Equatorial Guinea. The results of mtDNA analyses of most of the known phenotypes of the genus Mesoaphyosemion and the ‘Aphyosemion’ herzogi species group, respectively, are presented. Both new Mesoaphyosemion species have dark blotches on the posterior flanks and resemble M. maculatum from Gabon, yet they are not closely related to that species. Although the two new species occur in very close proximity, DNA results suggest no close relationship. The ‘Aphyosemion’ herzogi species group has a similar distribution as the genus Mesoaphyosemion, but with its northern boundary in southern Cameroon. Based on mtDNA the new ‘Aphyosemion’ from the Mitemele drainage in south west Equatorial Guinea is basal species to the remaining species group. It is distinguished from the two described congeners, ‘A.’ bochtleri and ‘A.’ herzogi by a diagnostic combination of colouration characters. Unpaired fins and flanks have a green background and caudal peduncle is often yellow to golden with dark red irregular dark red bars. The genetic dataindicate that the species group contains several additional, genetically and by colour pattern well separated, potentiallyundescribedspecies. urn:lsid:zoobank.org:pub:2752DAEA-BEFE-4D6D-8D5C-FB3F0D265A4DSe describen para la parte continental de Guinea Ecuatorial dos nuevas especies de&nbsp;Mesoaphyosemion&nbsp;y una nueva especie del grupo de especies&nbsp;‘Aphyosemion’ herzogi.&nbsp;También, se presentan los resultados de los análisis de DNAmt de casi todos los fenotipos conocidos del género&nbsp;Mesoaphyosemion&nbsp;y del grupo de especies ‘Aphyosemion’ herzogi.&nbsp;Ambas nuevas especies de&nbsp;Mesoaphyosemion&nbsp;tienen manchas oscuras en los flancos posteriores y se parecen a&nbsp;M. maculatum&nbsp;de Gabón, pero no están estrechamente relacionadas con esa especie. Aunque las dos nuevas especies son próximas, los resultados del ADN sugieren que no existe entre ellas una relación cercana. El grupo de especies ‘Aphyosemion’ herzogi&nbsp;tiene una distribución similar a la de&nbsp;Mesoaphyosemion,&nbsp;pero con su límite norte en el sur de Camerún. Basado en ADNmt, el nuevo ‘Aphyosemion’&nbsp;de la cuenca del río Mitemele, en el suroeste de la parte continental de Guinea Ecuatorial, es una especie basal al resto de las especies estudiadas. Se distingue de los dos congéneres descritos, ‘A.’ bochtleri&nbsp;y ‘A.’ herzogi&nbsp;por una combinación de caracteres diagnósticos de la coloración. Las aletas impares y los flancostienen un fondo verde y el pedúnculo caudal suele ser de color amarillo a dorado con barras rojo oscuro irregulares. Los datos genéticosindicanque el grupo de especies contiene varias especies más, que están genéticamente y por patrón de coloración bien delimitadas, y que no han sido formalmente descritas

    Forming new sex partnerships while overseas: findings from the third British national survey of sexual attitudes & lifestyles (Natsal-3)

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    Objectives: Travelling away from home presents opportunities for new sexual partnerships, which may be associated with sexually transmitted infection (STI) risk. We examined the prevalence of, and factors associated with, reporting new sexual partner(s) while overseas, and whether this differed by partners’ region of residence. Methods: We analysed data from 12 530 men and women aged 16–74 years reporting ≥1 sexual partner(s) in the past 5 years in Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3), a probability survey undertaken 2010–2012. Results: 9.2% (95% CI 8.3% to 10.1%) of men and 5.3% (4.8% to 5.8%) of women reported new sexual partner(s) while overseas in the past 5 years. This was strongly associated with higher partner numbers and other sexual and health risk behaviours. Among those with new partners while overseas, 72% of men and 58% of women reported partner(s) who were not UK residents. Compared with those having only UK partners while abroad, these people were more likely to identify as ‘White Other’ or ‘Non-White’ (vs White British ethnicity), report higher partner numbers, new partners from outside the UK while in the UK and paying for sex (men only) all in the past 5 years. There was no difference in reporting STI diagnosis/es during this time period. Conclusions: Reporting new partners while overseas was associated with a range of sexual risk behaviours. Advice on sexual health should be included as part of holistic health advice for all travellers, regardless of age, destination or reason for travel

    Clinical and radiological features of pulmonary disease due to culture-positive M. tuberculosis or nontuberculous mycobacteria in South African gold miners.

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    Pulmonary mycobacterial disease may be due to Mycobacterium tuberculosis or nontuberculous mycobacteria (NTM

    Managing structural uncertainty in health economic decision models: a discrepancy approach

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    Healthcare resource allocation decisions are commonly informed by computer model predictions of population mean costs and health effects. It is common to quantify the uncertainty in the prediction due to uncertain model inputs, but methods for quantifying uncertainty due to inadequacies in model structure are less well developed. We introduce an example of a model that aims to predict the costs and health effects of a physical activity promoting intervention. Our goal is to develop a framework in which we can manage our uncertainty about the costs and health effects due to deficiencies in the model structure. We describe the concept of `model discrepancy': the difference between the model evaluated at its true inputs, and the true costs and health effects. We then propose a method for quantifying discrepancy based on decomposing the cost-effectiveness model into a series of sub-functions, and considering potential error at each sub-function. We use a variance based sensitivity analysis to locate important sources of discrepancy within the model in order to guide model refinement. The resulting improved model is judged to contain less structural error, and the distribution on the model output better reflects our true uncertainty about the costs and effects of the intervention
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