64 research outputs found

    Laser-cooling simulation based on the semiclassical approach

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    We investigate the region of validity of the semiclassical approach to simulating laser cooling. We conclude that for the commonly used pi(x) pi(y) polarization-gradient configuration, the semiclassical approach is valid only for transitions with recoil parameters epsilon(r), on the order of 10(-4) or less. For the standard laser-cooling transitions only the transitions in Rb and Cs satisfy this condition. For the Doppler and sigma(+)sigma(-) polarization-gradient configuration the semiclassical approach is valid for most of the commonly used transitions; however, the expected gain in execution speed compared with quantum Monte Carlo calculations has been realized only in part. A drastic reduction in calculation time is to be expected by implementing an analytical approach to the long-term contribution of the diffusion coefficient. (c) 2005 Optical Society of America

    High-throughput Proteomics Identifies THEMIS2 as Independent Biomarker of Treatment-free Survival in Untreated CLL

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    It remains challenging in chronic lymphocytic leukemia (CLL) to distinguish between patients with favorable and unfavorable time-to-first treatment (TTFT). Additionally, the downstream protein correlates of well-known molecular features of CLL are not always clear. To address this, we selected 40 CLL patients with TTFT ≤24 months and compared their B cell intracellular protein expression with 40 age- and sex-matched CLL patients with TTFT &gt;24 months using mass spectrometry. In total, 3268 proteins were quantified in the cohort. Immunoglobulin heavy-chain variable (IGHV) mutational status and trisomy 12 were most impactful on the CLL proteome. Comparing cases to controls, 5 proteins were significantly upregulated, whereas 3 proteins were significantly downregulated. Of these, only THEMIS2, a signaling protein acting downstream of the B cell receptor, was significantly associated with TTFT, independently of IGHV and TP53 mutational status (hazard ratio, 2.49 [95% confidence interval, 1.62-3.84]; P &lt; 0.001). This association was validated on the mRNA and protein level by quantitative polymerase chain reaction and ELISA, respectively. Analysis of 2 independently generated RNA sequencing and mass spectrometry datasets confirmed the association between THEMIS2 expression and clinical outcome. In conclusion, we present a comprehensive characterization of the proteome of untreated CLL and identify THEMIS2 expression as a putative biomarker of TTFT.</p

    Increases in HIV Incidence Following Receptive Anal Intercourse Among Women: A Systematic Review and Meta-analysis.

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    Receptive anal intercourse (RAI) carries a greater per-act risk of HIV acquisition than receptive vaginal intercourse (RVI) and may influence HIV epidemics driven by heterosexual sex. This systematic review explores the association between RAI and incident HIV among women, globally. We searched Embase and Medline through September 2018 for longitudinal studies reporting crude (cRR) or adjusted (aRR) relative risks of HIV acquisition by RAI practice among women. Of 27,563 articles identified, 17 eligible studies were included. We pooled independent study estimates using random-effects models. Women reporting RAI were more likely to acquire HIV than women not reporting RAI (pooled cRR = 1.56 95% CI 1.03-2.38, N = 18, I2 = 72%; pooled aRR = 2.23, 1.01-4.92, N = 5, I2 = 70%). In subgroup analyses the association was lower for women in Africa (pooled cRR = 1.16, N = 13, I2 = 21%) than outside Africa (pooled cRR = 4.10, N = 5, I2 = 79%) and for high-risk (pooled aRR = 1.69, N = 4, I2 = 63%) than general-risk women (pooled aRR = 8.50, N = 1). Interview method slightly influenced cRR estimates (p value = 0.04). In leave-one-out sensitivity analyses pooled estimates were generally robust to removing individual study estimates. Main limitations included poor exposure definition, incomplete adjustment for confounders, particularly condom use, and use of non-confidential interview methods. More and better data are needed to explain differences in risk by world region and risk population. Women require better counselling and greater choice in prevention modalities that are effective during RVI and RAI

    What Proportion of Female Sex Workers Practise anal Intercourse and How Frequently? A Systematic Review and Meta-analysis.

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    HIV is more efficiently acquired during receptive anal intercourse (AI) compared to vaginal intercourse (VI) and may contribute substantially to female sex workers' (FSW) high HIV burden. We aim to determine how common and frequent AI is among FSW globally. We searched PubMed, Embase and PsycINFO for studies reporting the proportion of FSW practising AI (prevalence) and/or the number of AI acts (frequency) worldwide from 01/1980 to 10/2018. We assessed the influence of participant and study characteristics on AI prevalence (e.g. continent, study year and interview method) through sub-group analysis. Of 15,830 identified studies, 131 were included. Nearly all (N = 128) reported AI prevalence and few frequency (N = 13), over various recall periods. Most studies used face-to-face interviews (N = 111). Pooled prevalences varied little by recall period (lifetime: 15.7% 95%CI 12.2-19.3%, N = 30, I2 = 99%; past month: 16.2% 95%CI 10.8-21.6%, N = 18, I2 = 99%). The pooled proportion of FSW reporting < 100% condom use tended to be non-significantly higher during AI compared to during VI (e.g. any unprotected VI: 19.1% 95%CI 1.7-36.4, N = 5 and any unprotected AI: 46.4% 95%CI 9.1-83.6, N = 5 in the past week). Across all study participants, between 2.4 and 15.9% (N = 6) of all intercourse acts (AI and VI) were anal. Neither AI prevalence nor frequency varied substantially by any participant or study characteristics. Although varied, AI among FSW is generally common, inconsistently protected with condoms and practiced sufficiently frequently to contribute substantially to HIV acquisition in this risk group. Interventions to address barriers to condom use are needed

    Distress and quality of life after autologous stem cell transplantation: a randomized clinical trial to evaluate the outcome of a web-based stepped care intervention

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    Background Psychological distress (i.e. depression and anxiety) is a strong predictor of functional status and other aspects of quality of life in autologous stem cell transplantation following high-dose chemotherapy. Treatment of psychological distress is hypothesized to result in improvement of functional status and other aspects of quality of life. The aim is to evaluate the outcome of stepped care for psychological distress on functional status and other aspects of quality of life in patients with hematological malignancy treated with autologous stem cell transplantation. Methods/Design The study is designed as a randomized clinical trial with 2 treatment arms: a stepped care intervention program versus care as usual. Patients are randomized immediately pre transplant. Stepped care and care as usual are initiated after a 6 weeks buffer period. Outcome is evaluated at 13, 30, and 42 weeks post transplant. In the experimental group, the first step includes an Internet-based self-help program. If psychological distress persists after the self-help intervention, the second step of the program is executed, i.e. a diagnostic evaluation and a standardized interview, yielding a problem analysis. Based on this information, a contract is made with the patient and treatment is provided consisting of individual face-to-face counseling, medication, or referral to other services. Care as usual comprises an interview with the patient, on ad hoc basis; emotional support and advice, on ad hoc basis; if urgent problems emerge, the patient is referred to other services. Primary outcome variables are psychological distress and functional status. Data are analyzed according to the intention to treat-principle. Discussion This study has several innovative characteristics. First, the outcome of the intervention for psychological distress in patients with hematological malignancy treated with autologous stem cell transplantation is evaluated in a randomized controlled study. Second, the impact of the intervention on functional status is evaluated: it is hypothesized that reduction of psychological distress results in improved functional status. Furthermore, the intervention concerns an Internet-based treatment in the first step. Finally, the intervention is characterized by an emphasis on self-management, efficiency, and a multi-disciplinary approach with nurses taking up a central role
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