Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Navegação na artroplastia total do joelho: existe vantagem?

OBJETIVO: Avaliar se a cirurgia auxiliada por navegação oferece vantagens sobre a técnica convencional, foi desenvolvido um estudo randômico, prospectivo e comparativo analisando o posicionamento do implante, alinhamento do membro, tempo de cirurgia, perda sanguínea e reabilitação funcional. MÉTODOS: Foram estudados 39 pacientes submetidos a 42 Artroplastias Totais de Joelho. No grupo 1 (n=21) a cirurgia foi navegada e no grupo 2 (n=21) convencional. Os pacientes foram avaliados com radiografia panorâmica de membros inferiores, tomografia computadorizada e pelo Knee Society Score (KSS) no pré-operatório e com três meses de pós-operatório. O tempo de cirurgia e a perda sanguínea pós-operatória também foram avaliados. RESULTADOS: O tempo de cirurgia foi maior no grupo 1. Não houve diferença significativa quanto à perda sanguínea e ao KSS. Houve maior proximidade dos três graus de rotação externa e dos cinco graus de inclinação coronal nos pacientes do grupo 2. O eixo mecânico aproximou-se mais de zero grau no grupo 1. CONCLUSÕES: A navegação promove um posicionamento individualizado dos componentes da prótese oferecendo vantagens no realinhamento do membro. O tempo cirúrgico tende a ser maior na técnica navegada, porém, não foi estatisticamente significante. Não há diferenças na perda sanguínea e na melhora do KSS. Nivel de Evidência I, estudo terapeutico.OBJECTIVE: Aiming to evaluate whether surgery aided navigation offers any advantages over the conventional technique, a randomized, prospective, comparative study was carried out, analyzing the placement of components, alignment of the limb, surgical time, blood loss and functional rehabilitation. MATERIAL AND METHODS: We studied 39 patients submitted42 Total Knee Arthroplasties. In group 1 (n = 21) the surgery was navigated and in group 2 (n = 21) it was conventional. The patients were evaluated on panoramic radiographs of the lower limbs, CT scan and the Knee Society Score (KSS) preoperatively and three months postoperatively. Surgery time and postoperative blood loss were also evaluated. RESULTS: Surgery time was longer in group 1. There was no significant difference in blood loss and the KSS. There was a greater proximity of the three degrees of external rotation and the five degrees of tilt in the coronal in group 2. The mechanical axis was closer to zero degree in group CONCLUSIONS: Navigation promotes individualizing of the positioning of the components of the prosthesis, and offered advantages in limb realignment, compared with traditional methods. The surgerytime has a tendency to be higher in group 2, but this difference is not statistically significant. There were no differences between the groups in relation to blood loss and improvement in KSS. Level of Evidence: Level I, therapeutic studies

Risk factors for default from tuberculosis treatment in HIV-infected individuals in the state of Pernambuco, Brazil: a prospective cohort study

BACKGROUND: Concomitant treatment of Human Immunodeficiency Virus (HIV) infection and tuberculosis (TB) presents a series of challenges for treatment compliance for both providers and patients. We carried out this study to identify risk factors for default from TB treatment in people living with HIV. METHODS: We conducted a cohort study to monitor HIV/TB co-infected subjects in Pernambuco, Brazil, on a monthly basis, until completion or default of treatment for TB. Logistic regression was used to calculate crude and adjusted odds ratios, 95% confidence intervals and P-values. RESULTS: From a cohort of 2310 HIV subjects, 390 individuals (16.9%) who had started treatment after a diagnosis of TB were selected, and data on 273 individuals who completed or defaulted on treatment for TB were analyzed. The default rate was 21.7% and the following risk factors were identified: male gender, smoking and CD4 T-cell count less than 200 cells/mm3. Age over 29 years, complete or incomplete secondary or university education and the use of highly active antiretroviral therapy (HAART) were identified as protective factors for the outcome. CONCLUSION: The results point to the need for more specific actions, aiming to reduce the default from TB treatment in males, younger adults with low education, smokers and people with CD4 T-cell counts < 200 cells/mm3. Default was less likely to occur in patients under HAART, reinforcing the strategy of early initiation of HAART in individuals with TB

HIV prevalence among female sex workers, drug users and men who have sex with men in Brazil: A Systematic Review and Meta-analysis

<p>Abstract</p> <p>Background</p> <p>The Brazilian response towards AIDS epidemic is well known, but the absence of a systematic review of vulnerable populations ─ men who have sex with men (MSM), female sex workers (FSW), and drug users (DU) remains a main gap in the available literature. Our goal was to conduct a systematic review and meta-analysis of studies assessing HIV prevalence among MSM, FSW and DU, calculating a combined pooled prevalence and summarizing factors associated the pooled prevalence for each group.</p> <p>Methods</p> <p>Nine electronic databases (MEDLINE via PubMed, EMBASE, Cochrane CENTRAL, AIDSLINE, AMED, CINAHL, TOXNET, SciELO, and ISI-Web of Science) were searched for peer-reviewed papers published in English, French, Spanish or Portuguese, from 1999 to 2009. To be included in the review, studies had to measure HIV prevalence and/or incidence as the primary outcome among at least one specific population under analysis.</p> <p>Results</p> <p>The studies targeting the three populations analyzed mostly young participants aged 30 years or less. Among FSW, eight studies were selected (3,625 participants), consistently identifying higher condom use with sexual clients than with occasional and stable partners. The combined HIV prevalence for FSW was 6.2 (95% CI: 4.4-8.3). Ten studies targeting MSM were identified (6,475 participants). Unprotected anal intercourse was commonly reported on those studies, but with great variability according to the nature of the relationship - stable vs. occasional sex partners - and sexual practice - receptive vs. insertive anal sex. Pooled HIV prevalence for MSM was 13.6 (95% CI: 8.2-20.2). Twenty nine studies targeting DU were identified (13,063 participants). Those studies consistently identified injection drug use and syringe/needle sharing as key predictors of HIV-infection, as well as engagement in sex work and male-to-male sex. The combined HIV prevalence across studies targeting DU was 23.1 (95% CI: 16.7-30.2).</p> <p>Conclusions</p> <p>FSW, MSM and DU from Brazil have a much risk of acquiring HIV infection compared to the general population, among which HIV prevalence has been relatively low (~0.6%). Those vulnerable populations should be targeted by focused prevention strategies that provide accurate information, counseling and testing, as well as concrete means to foster behavior change (e.g. access to condoms, drug abuse treatment, and clean syringes in the case of active injecting drug users), tailored to gender and culture-specific needs. Programs that provide these services need to be implemented on public health services throughout the country, in order to decrease the vulnerability of those populations to HIV infection.</p