2,408 research outputs found

    Spin signatures of exchange-coupled triplet pairs formed by singlet fission

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    We study the effect of an exchange interaction on the magnetic-field-dependent photoluminescence in singlet fission materials. We show that, for strongly interacting triplet exciton pairs (intertriplet exchange interaction greater than the intratriplet spin-dipolar interaction), quantum beating and magnetic-field effects vanish apart from at specific magnetic fields where singlet and quintet levels are mixed by a level anticrossing. We characterize these effects and show that the absence of a magnetic-field effect or zero-field quantum beats does not necessarily mean that fission is inoperative. These results call for a reconsideration of the observations that are considered hallmarks of singlet fission and demonstrate how the spin coherence and exchange coupling of interacting triplet pairs can be measured through magneto-photoluminescence experiments.Engineering and Physical Sciences Research Council (Grant ID: EP/G060738/1)This is the author accepted manuscript. The final version is available from the American Physical Society via http://dx.doi.org/10.1103/PhysRevB.94.04520

    Male Circumcision at Different Ages in Rwanda: A Cost-Effectiveness Study

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    Agnes Binagwaho and colleagues predict that circumcision of newborn boys would be effective and cost-saving as a long-term strategy to prevent HIV in Rwanda

    The Perceptions on Male Circumcision as a Preventive Measure Against HIV Infection and Considerations in Scaling up of the Services: A Qualitative Study Among Police Officers in Dar es Salaam, Tanzania.

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    \ud In recent randomized controlled trials, male circumcision has been proven to complement the available biomedical interventions in decreasing HIV transmission from infected women to uninfected men. Consequently, Tanzania is striving to scale-up safe medical male circumcision to reduce HIV transmission. However, there is a need to investigate the perceptions of male circumcision in Tanzania using specific populations. The purpose of the present study was to assess the perceptions of male circumcision in a cohort of police officers that also served as a source of volunteers for a phase I/II HIV vaccine (HIVIS-03) trial in Dar es Salaam, Tanzania. In-depth interviews with 24 men and 10 women were conducted. Content analysis informed by the socio-ecological model was used to analyze the data. Informants perceived male circumcision as a health-promoting practice that may prevent HIV transmission and other sexually transmitted infections. They reported male circumcision promotes sexual pleasure, confidence and hygiene or sexual cleanliness. They added that it is a religious ritual and a cultural practice that enhances the recognition of manhood in the community. However, informants were concerned about the cost involved in male circumcision and cleanliness of instruments used in medical and traditional male circumcision. They also expressed confusion about the shame of undergoing circumcision at an advanced age and pain that could emanate after circumcision. The participants advocated for health policies that promote medical male circumcision at childhood, specifically along with the vaccination program. The perceived benefit of male circumcision as a preventive strategy to HIV and other sexually transmitted infections is important. However, there is a need to ensure that male circumcision is conducted under hygienic conditions. Integrating male circumcision service in the routine childhood vaccination program may increase its coverage at early childhood. The findings from this investigation provide contextual understanding that may assist in scaling-up male circumcision in Tanzania.\u

    "After my husband's circumcision, I know that I am safe from diseases": Women's Attitudes and Risk Perceptions Towards Male Circumcision in Iringa, Tanzania.

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    While male circumcision reduces the risk of female-to-male HIV transmission and certain sexually transmitted infections (STIs), there is little evidence that circumcision provides women with direct protection against HIV. This study used qualitative methods to assess women's perceptions of male circumcision in Iringa, Tanzania. Women in this study had strong preferences for circumcised men because of the low risk perception of HIV with circumcised men, social norms favoring circumcised men, and perceived increased sexual desirability of circumcised men. The health benefits of male circumcision were generally overstated; many respondents falsely believed that women are also directly protected against HIV and that the risk of all STIs is greatly reduced or eliminated in circumcised men. Efforts to engage women about the risks and limitations of male circumcision, in addition to the benefits, should be expanded so that women can accurately assess their risk of HIV or STIs during sexual intercourse with circumcised men

    Contamination of clinical specimens with MLV-encoding nucleic acids: implications for XMRV and other candidate human retroviruses

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    Efforts to assess the prevalence of xenotropic murine leukemia virus-related virus (XMRV) in patients with prostate cancer and chronic fatigue syndrome have relied heavily on PCR-based testing of clinical samples and have yielded widely divergent findings. This week in Retrovirology, reports from four independent research groups illustrate the extreme care needed to exclude DNA or RNA contamination in PCR analyses of XMRV. In addition, phylogenetic evidence suggesting that previously-published XMRV sequences originated from a commonly-used prostate carcinoma cell line (22Rv1) is presented. These findings raise important questions regarding the provenance of XMRV and its potential connection to human disease

    Scoliosis in patients with Prader Willi Syndrome – comparisons of conservative and surgical treatment

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    In children with Prader Willi syndrome (PWS), besides growth hormone (GH) therapy, control of the food environment and regular exercise, surgical treatment of scoliosis deformities seems the treatment of choice, even though the risks of spinal surgery in this specific population is very high. Therefore the question arises as to whether the risks of spinal surgery outweigh the benefits in a condition, which bears significant risks per se. The purpose of this systematic review of the Pub Med literature was to find mid or long-term results of spinal fusion surgery in patients with PWS, and to present the conservative treatment in a case study of nine patients with this condition

    Implementing Voluntary Medical Male Circumcision for HIV Prevention in Nyanza Province, Kenya: Lessons Learned during the First Year

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    In 2007, the World Health Organization endorsed male circumcision as an effective HIV prevention strategy. In 2008, the Government of Kenya (GoK) launched the national voluntary medical male circumcision (VMMC) program in Nyanza Province, the geographic home to the Luo, the largest non-circumcising ethnic group in Kenya. Currently, several other African countries are in the early stages of implementing this intervention.This paper uses data from a health facility needs assessment (n = 81 facilities) and a study to evaluate the implementation of VMMC services in 16 GoK facilities (n = 2,675 VMMC clients) to describe Kenya's experience in implementing the national program. The needs assessment revealed that no health facility was prepared to offer the minimum package of services as outlined by the national guidelines, and partner organizations were called upon to fill this gap. The findings concerning human resource shortages facilitated the GoK's decision to endorse trained nurses to provide VMMCs, enabling more facilities to offer the service. Findings from the evaluation study resulted in replacing voluntary counseling and testing (VCT) with provider-initiated testing and counseling (PITC) and subsequently doubling the proportion of VMMC clients tested for HIV.This paper outlines how certain challenges, like human resource shortages and low HIV test rates, were addressed through national policy changes, while other challenges, like large fluctuations in demand, were addressed locally. Currently, the program requires significant support from partner organizations, but a strategic plan is under development to continue to build capacity in GoK staff and facilities. Coordination between all parties was essential and was facilitated through the formation of national, provincial, and district VMMC task forces. The lessons learned from Kenya's VMMC implementation experience are likely generalizable to other African countries

    The management of bipolar mania: a national survey of baseline data from the EMBLEM study in Italy

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    <p>Abstract</p> <p>Background</p> <p>Although a number of studies have assessed the management of mania in routine clinical practice, no studies have so far evaluated the short- and long-term management and outcome of patients affected by bipolar mania in different European countries.</p> <p>The objective of the study is to present, in the context of a large multicenter survey (EMBLEM study), an overview of the baseline data on the acute management of a representative sample of manic bipolar patients treated in the Italian psychiatric hospital and community settings. EMBLEM is a 2-year observational longitudinal study that evaluates across 14 European countries the patterns of the drug prescribed in patients with bipolar mania, their socio-demographic and clinical features and the outcomes of the treatment.</p> <p>Methods</p> <p>The study consists of a 12-week acute phase and a ≤ 24-month maintenance phase. Bipolar patients were included into the study as in- or out-patients, if they initiated or changed, according to the decision of their psychiatrist, oral antipsychotics, anticonvulsants and/or lithium for the treatment of an episode of mania.</p> <p>Data concerning socio-demographic characteristics, psychiatric and medical history, severity of mania, prescribed medications, functional status and quality of life were collected at baseline and during the follow-up period.</p> <p>Results</p> <p>In Italy, 563 patients were recruited in 56 sites: 376 were outpatients and 187 inpatients. The mean age was 45.8 years. The mean CGI-BP was 4.4 (± 0.9) for overall score and mania, 1.9 (± 1.2) for depression and 2.6 (± 1.6) for hallucinations/delusions. The YMRS showed that 14.4% had a total score < 12, 25.1% ≥ 12 and < 20, and 60.5% ≥ 20. At entry, 75 patients (13.7%) were treatment-naïve, 186 (34.1%) were receiving a monotherapy (of which haloperidol [24.2%], valproate [16.7%] and lithium [14.5%] were the most frequently prescribed) while 285 (52.2%) a combined therapy (of which 8.0% were represented by haloperidol/lithium combinations). After a switch to an oral medication, 137 patients (24.8%) were prescribed a monotherapy while the rest (415, 75.2%) received a combination of drugs.</p> <p>Conclusion</p> <p>Data collected at baseline in the Italian cohort of the EMBLEM study represent a relevant source of information to start addressing the short and long-term therapeutic strategies for improving the clinical as well as the socio-economic outcomes of patients affected by bipolar mania. Although it's not an epidemiological investigation and has some limitations, the results show several interesting findings as a relatively late age of onset of bipolar disorder, a low rate of past suicide attempts, a low lifetime rate of alcohol abuse and drug addiction.</p

    Male Circumcision in the General Population of Kisumu, Kenya: Beliefs about Protection, Risk Behaviors, HIV, and STIs

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    Using a population-based survey we examined the behaviors, beliefs, and HIV/HSV-2 serostatus of men and women in the traditionally non-circumcising community of Kisumu, Kenya prior to establishment of voluntary medical male circumcision services. A total of 749 men and 906 women participated. Circumcision status was not associated with HIV/HSV-2 infection nor increased high risk sexual behaviors. In males, preference for being or becoming circumcised was associated with inconsistent condom use and increased lifetime number of sexual partners. Preference for circumcision was increased with understanding that circumcised men are less likely to become infected with HIV
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