We demonstrate a broadband acousto-optic notch filter based on a tubular-lattice hollow-core fiber for the first time to our knowledge. The guided optical modes are modulated by acoustically induced dynamic long-period gratings along the fiber. The device is fabricated employing a short interaction length (7.7â cm) and low drive voltages (10â V). Modulated spectral bands with 20â nm half-width and maximum depths greater than 60% are achieved. The resonant notch wavelength is tuned from 743 to 1355â nm (612â nm span) by changing the frequency of the electrical signal. The results indicate a broader tuning range compared to previous studies using standard and hollow-core fibers. It further reveals unique properties for reconfigurable spectral filters and fiber lasers, pointing to the fast switching and highly efficient modulation of all-fiber photonic devices.
Introduction: Although international health research involves some benefits for the host countries, such as access to innovative treatments, the research itself may not be aligned with their communities' actual health needs. Objective: To map the global landscape of clinical trials run in Latin American and Caribbean countries and discuss the addressing of local health needs in the agenda of international clinical trials. Methods: The present study is a cross-sectional overview and used data referent to studies registered between 01/01/2014 and 12/31/2014 in the World Health Organization's (WHO) International Clinical Trials Registry Platform (ICTRP). Results: Non-communicable diseases such as diabetes, cancer, and asthma-studies which were financed mainly by industries-were the conditions investigated most in the region of Latin America and the Caribbean. The neglected diseases, on the other hand, such as Chagas disease, and dengue, made up 1% of the total number of studies. Hospitals and nonprofit nongovernmental organizations prioritize resources for investigating new drugs for neglected diseases, such as Chagas disease and dengue. Conclusion: The international multicenter clinical trials for investigating new drugs are aligned with the health needs of the region of Latin America and the Caribbean, when one considers the burden resulting from the non-communicable diseases in this region. However, the transmissible diseases, such as tuberculosis and AIDS, and the neglected diseases, such as Chagas disease and dengue, which have an important impact on public health in this region, continue to arouse little interest among the institutions which finance the clinical trials.
Background: Although policies and guidelines make use of the concept of vulnerability, few define it. The European Union's directive for clinical trials does not include explanations for or the reasoning behind the designation of certain groups as vulnerable. Emerging economies from lower middle-income countries have, in recent years, had the largest average annual growth rate, as well as increase, in number of clinical trials registered in the US government's database. Nevertheless, careful supervision of research activities has to be ensured. Objective: To describe and analyze the features of the clinical trials involving vulnerable populations in various countries classified by development status and geographic region. Methods: Retrospective study that involved analysis of data obtained from the International Clinical Trials Registry Platform (ICTRP) database between 01/2014 and 12/2014 from countries with (i) highest trial densities during 2005 to 2012, (ii) highest average growth rate in clinical trials, and (iii) greatest trial capabilities. Results: Statistical analysis of this study showed that patients incapable of giving consent personally are 11.4 times more likely to be vulnerable patients than patients who are capable, and that patients in upper-middle-income countries are 1.7 times more likely to be vulnerable patients than patients from high-income countries when participating in global clinical trials. Malaysia (21%), Egypt (20%), Turkey (19%), Israel (18%), and Brazil (17%) had the highest percentages of vulnerable populations involving children. Conclusions: Although the inability to provide consent personally was a factor associated with vulnerability, arbitrary criteria may have been considered when classifying the populations of clinical trials as vulnerable. The EU Clinical Trials Register should provide guidance regarding exactly what aspects or factors should be taken into account to frame given populations as vulnerable, because vulnerability is not applicable to all risk situations.
