72 research outputs found

    One Methylene Group in the Side Chain Can Alter by 90 Degrees the Orientation of a Main-Chain Liquid Crystal on a Unidirectional Substrate

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    The mechanisms of orientation of columnar liquid crystals (LCs) on PTFE-rubbed surface are explored on a homologous series of symmetrically-substituted poly(di-n-alkylsiloxanes) (PDAS). It is shown that by increasing the side-chain length in steps of one CH2 group the orientation of PDAS switches back and forth from perpendicular to parallel with respect to PTFE chains. These changes sensitive to the smallest possible variation of the macromolecular structure (i.e., modification of the side chain length by just one CH2 group) reflect the change of the alignment mechanism identified as grapho-epitaxial or epitaxial for the perpendicular and parallel orientation, respectively. The results show that two orthogonal LC orientations are realizable on the same rubbed substrate, which can open new perspectives in the field of organic and printed electronics such as multi-domain LCD technology

    Comparison of prevalence, viral load, physical status and expression of human papillomavirus-16, -18 and -58 in esophageal and cervical cancer: a case-control study

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    Background: Human papillomavirus (HPV) infection is a major risk factor for the development of nearly all cases of cervical cancer worldwide. The presence of HPV DNA in cases of esophageal squamous-cell carcinoma (ESCC) has been reported repeatedly from Shantou, China, and other regions with a high incidence of esophageal carcinoma (EC). However, unlike in cervical squamous-cell carcinoma (CSCC), in ESCC, the characteristics of HPV are unclear. Thus, the role of high-risk HPV types in the carcinogenesis of ESCC remains uncertain. Methods: Seventy cases of ESCC with 60 controls and 39 cases of CSCC with 54 controls collected from patients in Shantou region in China were compared for the distributions of HPV-16, -18 and -58; viral load; and viral integration using real-time PCR assay and HPV-16 expression using immunostaining. Results: The detection rates and viral loads of HR-HPV infection were significantly lower in ESCC than in CSCC (50.0% vs. 79.48%, P = 0.005; 2.55 +/- 3.19 vs. 361.29 +/- 441.75, P = 0.002, respectively). The combined integration level of HPV-16, -18 and -58 was slightly lower in ESCC than in CSCC (P = 0.022). HPV-16 expression was detected in 59.26% of ESCC tissue and significantly associated with tumour grade (P = 0.027). Conclusions: High levels of HR-HPV expression and integration may be an indicator of the risk of ESCC, at least for patients in the Shantou region of China. However, a relatively low HPV copy number and infection rate in ESCC is unlikely to play an essential a role in the carcinogenesis of ESCC as in cervical cancer. Factors other than HR-HPV infection may contribute to the carcinogenesis of ESCC.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000285251600001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701OncologySCI(E)26ARTICLEnull1

    Human papillomavirus infection in honduran women with normal cytology

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    Contains fulltext : 80440.pdf (publisher's version ) (Closed access)OBJECTIVE: This study was aimed at estimating type-specific HPV prevalence and its cofactors among Honduran women with normal cytology in order to provide valuable information to health policymakers about the epidemiology of this important sexually transmitted infection. METHODS: A total of 591 women with normal cytology from Tegucigalpa, Honduras were interviewed and tested for HPV using the SPF10 LiPA25. A structured epidemiological questionnaire was administered to each woman. RESULTS: The overall HPV prevalence was 51%. Twenty-three types of HPV were detected; HPV 16, 51, 31, 18, and 11 were the most common. The highest prevalence of cancer associated HPV types (15.0%) was found in the women less than 35 years. Besides the association with age, the main independent predictors of HPV infection were the lifetime number of sexual partners and having a low socioeconomic status and less than 5 previous Pap smears. CONCLUSIONS: In the population studied, there was a broad diversity of HPV infections, with high-risk types being the most common types detected. The establishment of a well-characterized population with regard to the community prevalence of type-specific HPV infection will provide a valuable baseline for monitoring population effectiveness of an HPV vaccine

    Simian Varicella Virus Infection of Rhesus Macaques Recapitulates Essential Features of Varicella Zoster Virus Infection in Humans

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    Simian varicella virus (SVV), the etiologic agent of naturally occurring varicella in primates, is genetically and antigenically closely related to human varicella zoster virus (VZV). Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP) resulted in persistent infection. More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted. Thus, previous NHP models were not ideally suited to analyze the immune response to SVV during acute infection and the transition to latency. Here, we show for the first time that intrabronchial inoculation of rhesus macaques with SVV closely mimics naturally occurring varicella (chickenpox) in humans. Infected monkeys developed varicella and viremia that resolved 21 days after infection. Months later, viral DNA was detected only in ganglia and not in non-ganglionic tissues. Like VZV latency in human ganglia, transcripts corresponding to SVV ORFs 21, 62, 63 and 66, but not ORF 40, were detected by RT-PCR. In addition, as described for VZV, SVV ORF 63 protein was detected in the cytoplasm of neurons in latently infected monkey ganglia by immunohistochemistry. We also present the first in depth analysis of the immune response to SVV. Infected animals produced a strong humoral and cell-mediated immune response to SVV, as assessed by immunohistology, serology and flow cytometry. Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation

    Using spatial reliability in the probabilistic study of concrete structures: The example of a reinforced concrete beam subjected to carbonatation inducing corrosion

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    Several methods, simple or more sophisticated, are tested to determine useful information for reliability problems involving spatial variability. The methods are developed around a simple example of a reinforced concrete beam subjected to carbonation inducing corrosion. A point-in-space reliability analysis is conducted to estimate a first indicator on the length to be replaced. Then, random field are introduced and are taken into account in the reliability problem using simulations methods to determine the empirical cumulative density function (CDF) of the length to be repaired and its moments. Finally, analytical formulations are used to estimate the same moments but with small computational effort

    Maps of the Iberian Peninsula — Comparison Xi, Omega Recension [Jupyter notebook]

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    Ptolemy's catalogue of localities contains a list of places with their coordinates that enables to draw maps of the Iberian Peninsula. Ptolemy's text came down to us in two versions that are sometimes different regarding the spelling of the toponyms and the values of the coordinates. These versions are usually called "Omega recension" and "Xi recension". Based on the Greek text of Ptolemy's catalogue edited by A. Stückelberger and G. Graßhoff (2006), we will draw Ptolemy's map of the Iberian Peninsula and compare the two transmitted versions of his work.This jupyter notebook maps the locations of both recensions

    Longitude

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    Longitude

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    International audienc
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