108 research outputs found

    Universal imprinting of chirality with chiral light by employing plasmonic metastructures

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    Chirality, either of light or matter, has proved to be very practical in biosensing and nanophotonics. However, the fundamental understanding of its temporal dynamics still needs to be discovered. A realistic setup for this are the so-called metastructures, since they are optically active and are built massively, hence rendering an immediate potential candidate. Here we propose and study the electromagnetic-optical mechanism leading to chiral optical imprinting on metastructures. Induced photothermal responses create anisotropic permittivity modulations, different for left or right circularly polarized light, leading to temporal-dependent chiral imprinting of hot-spots, namely imprinting of chirality. The above effect has not been observed yet, but it is within reach of modern experimental approaches. The proposed nonlinear chiroptical effect is general and should appear in any anisotropic material; however, we need to design a particular geometry for this effect to be strong. These new chiral time-dependent metastructures may lead to a plethora of applications.Comment: Main (29 pages, 6 figures) and supplemental (46 pages, 35 figures

    A 3-year multicentre randomized controlled trial of etonogestrel- and levonorgestrel-releasing contraceptive implants, with non-randomized matched copper-intrauterine device controls

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    STUDY QUESTION Is there any difference in the clinical performance of the 3-year one-rod etonogestrel (ENG)- and the 5-year two-rod levonorgestrel (LNG)-releasing contraceptive implants during 3 years of insertion, and between implant and intrauterine device (IUD) contraception, in particular complaints possibly related to hormonal contraceptives? SUMMARY ANSWER The cumulative contraceptive effectiveness after 3 years and method continuation through 2.5 years were not significantly different between ENG and LNG implants, but both outcomes were significantly worse in the non-randomized age-matched group of IUD users than in the combined implant group. WHAT IS KNOWN ALREADY ENG- and LNG-releasing implants are safe and highly efficacious contraceptives with pregnancy rates reported to be 0.0-0.5 per 100 women-years (W-Y). No head-to-head comparative study of the two implants has been undertaken, and little information is available on comparisons of complaints of side effects of implant and copper IUD users. STUDY DESIGN, SIZE, DURATION This was an open parallel group RCT with 1:1 allocation ratio of the ENG and the LNG implants with non-randomized control group of women choosing TCu380A IUD to address lack of reliable data on common side effects typically attributed to the use of progestogen-only contraceptives. After device(s) placement, follow-ups were at 2 weeks, 3 and 6 months, and semi-annually thereafter for 3 years or until pregnancy, removal or expulsion of the implant/IUD occurred. PARTICIPANTS, SETTING, METHODS The study took place in family planning clinics in Brazil, Chile, Dominican Republic, Hungary, Thailand, Turkey and Zimbabwe. Women seeking long-term contraception were enlisted after an eligibility check and informed consent, and 2982 women were enrolled: 1003, 1005 and 974 in the ENG-implant, LNG-implant and IUD groups, respectively; 995, 997 and 971, respectively, were included in the per protocol analysis reported here. MAIN RESULTS AND THE ROLE OF CHANCE ENG and LNG implants each had the same 3-year cumulative pregnancy rate of 0.4 per 100 W-Y [95% confidence interval (CI) 0.1-1.4]. A weight of ≥70 kg at admission was unrelated to pregnancy. Method continuation rates for ENG and LNG implants at 2.5 years were 69.8 (95% CI 66.8-72.6) and 71.8 per 100 W-Y (68.8-74.5), and at 3 years 12.1 (95% CI 5.2-22.0) and 52.0 per 100 W-Y (95% CI 41.8-61.2), respectively. Bleeding disturbances, the most frequent reason for method discontinuation, were significantly more common in the ENG group [16.7 (95% CI 14.4-19.3)] than in the LNG group [12.5 (95% CI 10.5-14.9)] (P 0.019). The 3-year cumulative loss to follow-up was lower in the ENG- than in the LNG-implant group, 8.1 (95% CI 6.4-10.2) and 14.4 per 100 W-Y (95% CI 12.1-17.1), respectively. The median duration of implant removal was 50 s shorter among women with ENG than among women with LNG implant (P < 0.0001). In the observational comparison between IUD and implant users, the 3-year relative risk for pregnancy in IUD group compared with the combined implant group was 5.7 per 100 W-Y (95% CI 4.4-7.3) (P = 0.0003). The 3-year expulsion rate of the IUD was 17.8 per 100 W-Y (95% CI 14.5-21.9), while the discontinuation rate for bleeding disturbances was 8.5 (95% CI 6.7-10.9). Frequency of complaints of headache and dizziness was not significantly different between implant and IUD users (P = 0.16 and 0.77, respectively), acne and bleeding irregularities were more frequent among implant users (P < 0.0001), while heavy bleeding and lower abdominal pain occurred more often among IUD than implant users (P < 0.0001). LIMITATIONS, REASONS FOR CAUTION Few women were ≤19 years old or nulligravida, the proportion of implant users ≥70 kg was <20% and <8% were obese. WIDER IMPLICATIONS OF THE FINDINGS Findings of the study can inform policy makers and clinicians about choice of implant, but also about TCu380A IUD in relation to implants. STUDY FUNDING/COMPETING INTEREST(S) UNDP/UNFPA/WHO/UNICEF/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research (RHR), World Health Organization (WHO). This report contains the views of an international expert group and does not necessarily represent the decisions or the stated policy of the WHO. TRIAL REGISTRATION ISRCTN33378571 registered on 22 March 2004. The first participant was enrolled on 12 May 200

    From planning to practice: building the national network for the surveillance of severe maternal morbidity

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    Background: Improving maternal health is one of the Millennium Development Goals for 2015. Recently some progress has been achieved in reducing mortality. On the other hand, in developed regions, maternal death is a relatively rare event compared to the number of cases of morbidity; hence studying maternal morbidity has become more relevant. Electronic surveillance systems may improve research by facilitating complete data reporting and reducing the time required for data collection and analysis. Therefore the purpose of this study was to describe the methods used in elaborating and implementing the National Network for the Surveillance of Severe Maternal Morbidity in Brazil. Methods: The project consisted of a multicenter, cross-sectional study for the surveillance of severe maternal morbidity including near-miss, in Brazil. Results: Following the development of a conceptual framework, centers were selected for inclusion in the network, consensus meetings were held among the centers, an electronic data collection system was identified, specific software and hardware tools were developed, research material was prepared, and the implementation process was initiated and analyzed. Conclusion: The conceptual framework developed for this network was based on the experience acquired in various studies carried out in the area over recent years and encompasses maternal and perinatal health. It is innovative especially in the context of a developing country. The implementation of the project represents the first step towards this planned management. The system online elaborated for this surveillance network may be used in further studies in reproductive and perinatal health

    Nivel de satisfacción de las clases online por parte de los estudiantes de Educación Física de Chile en tiempos de pandemia.

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    Introduction: In Chile the first case of COVID-19 was diagnosed on March 3, 2020 and on the eighteenth of the same month the president decreed state of catastrophe, so that classes at school and university level went from the presence to the virtuality. The present study aims to know the level of satisfaction of the virtual classes of the students of Physical Education. Methodology: Quantitative, non experimental, transversal. The sample consisted of 542 students of Physical Education from different study houses in Chile. The Satisfaction scale online classes was adapted and validated. Results: there are significant differences comparing theoretical and practical subjects, with theoretical chairs being better valued. Differences were also found by sex, where males have a more negative perception about virtual classes and when comparing by course, freshmen have a more positive perception about virtual classes in relation to higher courses. Conclusions: there is a resistance on the part of students to virtual classes in Physical Education, because, although significant differences were found between the theoretical and practical subjects, values were always around 3 on a scale of 1 to 5. Future research with other variables such as physical activity, stress levels and strategies for the teaching of Virtual Physical Education are necessary. (English) [ABSTRACT FROM AUTHOR]Introducción: En Chile el primer caso de COVID-19 fue diagnosticado el tres de marzo del 2020 y el día dieciocho del mismo mes el presidente decreto estado de catástrofe, por lo que las clases a nivel escolar y universitario pasaron de la presencialidad a la virtualidad. El presente estudio tiene como objetivo conocer el nivel de satisfacción de las clases virtuales de los estudiantes de Educación Física. Metodología: Cuantitativa, no experimental, transversal. La muestra estuvo constituida por 542 alumnos de Educación Física de diferentes casas de estudio de Chile. Se adaptó y validó la escala Satisfacción clases online. Resultados: existen diferencias significativas comparando las asignaturas teóricas y prácticas, siendo mejor valoradas las cátedras teóricas. También se encontraron diferencias por sexo, donde los varones poseen una percepción más negativa sobre las clases virtuales y al comparar por curso, los alumnos de primer año poseen una percepción más positiva sobre las clases virtuales en relación con los cursos superiores. Conclusiones: existe una resistencia por parte de los alumnos a las clases virtuales en la Educación Física, pues, si bien se encontraron diferencias significativas entre las asignaturas teóricas y prácticas, los valores siempre estuvieron alrededor de 3 en una escala de 1 a 5. Se hacen necesarias futuras investigaciones con otras variables como actividad física, niveles de estrés y estrategias para la enseñanza de la Educación Física virtual

    Vaginally Administered PEGylated LIF Antagonist Blocked Embryo Implantation and Eliminated Non-Target Effects on Bone in Mice

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    Female-controlled contraception/HIV prevention is critical to address health issues associated with gender inequality. Therefore, a contraceptive which can be administered in tandem with a microbicide to inhibit sexually transmitted infections, is desirable. Uterine leukemia inhibitory factor (LIF) is obligatory for blastocyst implantation in mice and associated with infertility in women. We aimed to determine whether a PEGylated LIF inhibitor (PEGLA) was an effective contraceptive following vaginal delivery and to identify non-uterine targets of PEGLA in mice

    Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation

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    The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for γ astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of γ cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nuclei (AGN) and of their relativistic jets. Observations of AGN with CTA will enable a measurement of γ absorption on the extragalactic background light with a statistical uncertainty below 15% up to a redshift z=2 and to constrain or detect γ halos up to intergalactic-magnetic-field strengths of at least 0.3 pG . Extragalactic observations with CTA also show promising potential to probe physics beyond the Standard Model. The best limits on Lorentz invariance violation from γ astronomy will be improved by a factor of at least two to three. CTA will also probe the parameter space in which axion-like particles could constitute a significant fraction, if not all, of dark matter. We conclude on the synergies between CTA and other upcoming facilities that will foster the growth of γ cosmology.</p

    Resources and procedures in the treatment of heavy menstrual bleeding with the levonorgestrel-releasing intrauterine system (LNG-IUS) or hysterectomy in Brazil

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background: Heavy menstrual bleeding (HMB) is the most common complaint of women seeking gynecological care. Treatments included surgical or medical options including hysterectomy and the levonorgestrel-releasing intrauterine system (LNG-IUS) due to the profound suppression of endometrial growth that intrauterine LNG exerts which results in amenorrhea or in a reduction of blood loss. Objective: The study was conducted to evaluate the resources and procedures involved in inserting an LNG-IUS compared to performing hysterectomy in women with HMB in a public sector hospital in Brazil. Study design: Two cohorts of women were studied: women who accepted an LNG-IUS (n=124) and matched women who underwent hysterectomy on the same day (n=122). We evaluate the number of procedures carried out in each group of women, including those performed before the decision was made to insert an LNG-IUS or to perform hysterectomy, the insertion of the device itself and the surgical procedure, in addition to the procedures and complications registered up to I year after LNG-IUS insertion or hysterectomy. Results: Age and the duration of HMB were significantly lower in the LNG-IUS acceptors than women at the hysterectomy group. The numbers of gynecological consultations and Pap smears were similar in both groups; however, women in the hysterectomy group also underwent laboratory tests, ultrasonography, chest X-ray and electrocardiogram. In the hysterectomy group, the main complications were hemorrhage (six), bladder/bowel perforation (four), complications with anesthesia (one), ureteral reimplantation required (one) and abdominal pain (two). At I year, HMB was controlled in 83.1% of women in the LNG-IUS group, and 106 women continued with the device. Conclusions: Both treatments were effective in HMB control. Fewer resources and complications were observed in LNG-IUS acceptors when compared to hysterectomy. The LNG-IUS represents a good strategy for reducing the number of hysterectomies and the resources required for women with HMB. (C) 2012 Elsevier Inc. All rights reserved.863244250Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [573747/2008-3

    Estimated disability-adjusted life years averted by free-of-charge provision of the levonorgestrel-releasing intrauterine system over a 9-year period in Brazil

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    The objective was to analyse the contribution of the provision at no cost to users of the 20 mu g/day levonorgestrel-releasing intrauterine system (LNG-IUS) towards disability-adjusted life years (DALY) averted over a 9-year period. We analysed data from 15 030 new users of the LNG-IUS who had the device inserted at 26 Brazilian teaching hospitals between January 2007 and December 2015. The devices came from the International Contraceptive Access Foundation (ICA), a not-for-profit foundation that donates the devices to developing countries for use by low-income women who desire long-term contraception and who freely choose to use this device. Estimation of the DALY averted included live births averted, maternal morbidity and mortality, child mortality and unsafe abortions averted. A total of 15 030 women chose the LNG-IUS as a contraceptive method during the study period. Over the 9 years of evaluation, the estimated cumulative contribution of the Brazilian program in terms of DALY averted consisted of 486 live births, 14 cases of combined maternal mortality and morbidity, 143 cases of child mortality and 410 unsafe abortions. Provision of the LNG-IUS at no cost to low-income Brazilian women reduced unwanted pregnancies and probably averted maternal mortality and morbidity, child mortality and unsafe abortions. Family planning programs, policymakers and stakeholders based in low-resource settings could take advantage of the information that the provision of this contraceptive at no cost, or at affordable cost to a publicly-insured population, is an effective policy to help promote women's health433181185CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP573747/2008/32015/20504/9International Contraceptive Access Foundation, Turku, Finlan

    Telerehabilitación en artroplastía de rodilla, alternativa terapéutica y desafío ético: Telerehabilitation in knee arthroplasty, therapeutic alternative and ethical challenge

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    Mr. Editor Acting as an alternative to the traditional treatment applied by kinesiologists, physical therapists or physiotherapists, telerehabilitation emerges, which as an emerging telemedicine field, is defined as a set of tools and procedures to develop the rehabilitation process remotely. With increasing support and evidence, it is used in a wide range of clinical conditions, providing an opportunity to people in rural and remote areas to obtain high-quality consulting and advice&nbsp;A main point of interest is people who underwent knee arthroplasty, the vast majority of whom are older adults, and who, while they remain in rehabilitation therapy, are in a state of fragility, demand the assistance of family members or caregivers and must assume costs and extra time to travel to be seen. For them, telerehabilitation is considered an effective alternative after hospital discharge, since similar results are obtained to conventional treatment in functional status and level of physical activity&nbsp;and, as it is developed with specialized clinical supervision, it reduces the costs of care maintaining an efficacy similar to traditional treatment at home or clinic.Sr. Editor Como una alternativa al tratamiento tradicional aplicado por kinesiólogos, terapeutas físicos o fisioterapeutas surge la telerehabilitación, que como campo emergente de la telemedicina, es definida como un conjunto de herramientas y procedimientos para desarrollar el proceso de rehabilitación de forma remota. Con cada vez mayor respaldo y evidencia, es utilizado en una amplia gama de afecciones clínicas, brindando una oportunidad para que las personas de zonas rurales y remotas obtengan consultoría y asesoramiento de alta calidad. Un foco de interés son las personas operadas con artroplastía de rodilla, que en su gran mayoría son adultos mayores, y que mientras se mantienen en terapia de rehabilitación cursan por un estado de fragilidad, demandan de la asistencia de familiares o cuidadores y deben asumir costos y tiempo extra para trasladarse a ser atendidos. Para ellos la telerehabilitación se considera una alternativa eficaz después del alta hospitalaria, dado que se obtienen resultados similares al tratamiento convencional en el estado funcional y el nivel de actividad física&nbsp;y al ser desarrollada con una supervisión clínica especializada reduce los costos de atención médica manteniendo una eficacia similar al tratamiento tradicional en el hogar o la clínica
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