A method of assessing the quality of pharmaceutical market and industry reports as a source to study access to medicines

This repository item contains a single issue of the Health and Development Discussion Papers, an informal working paper series that began publishing in 2002 by the Boston University Center for Global Health and Development. It is intended to help the Center and individual authors to disseminate work that is being prepared for journal publication or that is not appropriate for journal publication but might still have value to readers.Market and industry reports can be useful in studying access to medicines from a pharmaceutical market perspective. However, many market and industry reports lack some or much of the information required to conduct analyses to study access to medicines and are often not transparent in their data sources and research methodologies. The instrument developed in this study, titled the Pharmaceutical Market and Industry Report Assessment Tool (PIRAT), assesses the quality of pharmaceutical market and industry reports, specifically focusing on the needs of public health researchers, and includes criteria describing the content and quality of the market reports. The assessment tool generates an unweighted score indicating the relative strengths and weaknesses of reports

Quantitative analysis of single muscle fibre action potentials recorded at known distances

In vivo records of single fibre action potentials (SFAPs) have always been obtained at unknown distance from the active muscle fibre.\ud \ud A new experimental method has been developed enabling the derivation of the recording distance in animal experiments. A single fibre is stimulated with an intracellular micropipette electrode. The same electrode is used thereafter for labelling with an auto-fluorescent dye, Lucifer Yellow. In this method there is no use of chemical fixation. The tissue structure is kept as well as possible. In cross-sections the fluorescent fibre is seen and its position is quantitized with respect to the tip of one or more recording wire electrodes.\ud \ud Morphometric data, such as the recording distance and the fibre cross-sectional area, are used for the interpretation of parameters of the SFAPs (peak-peak amplitude, time between the first positive and negative peaks). The present results show that within 300 μm recording distance is not as dominant for the SFAP shape as expected.\ud \ud The method offers also a direct check of the relation between the muscle fibre; diameter and the conduction velocity of the action potential. In the present small set of data there is no simple linear relationship

Inter- and intra-layer excitons in MoS2_2/WS2_2 and MoSe2_2/WSe2_2 heterobilayers

Accurately described excitonic properties of transition metal dichalcogenide heterobilayers (HBLs) are crucial to comprehend the optical response and the charge carrier dynamics of them. Excitons in multilayer systems posses inter or intralayer character whose spectral positions depend on their binding energy and the band alignment of the constituent single-layers. In this study, we report the electronic structure and the absorption spectra of MoS$_2$/WS$_2$ and MoSe$_2$/WSe$_2$ HBLs from first-principles calculations. We explore the spectral positions, binding energies and the origins of inter and intralayer excitons and compare our results with experimental observations. The absorption spectra of the systems are obtained by solving the Bethe-Salpeter equation on top of a G$_0$W$_0$ calculation which corrects the independent particle eigenvalues obtained from density functional theory calculations. Our calculations reveal that the lowest energy exciton in both HBLs possesses interlayer character which is decisive regarding their possible device applications. Due to the spatially separated nature of the charge carriers, the binding energy of inter-layer excitons might be expected to be considerably smaller than that of intra-layer ones. However, according to our calculations the binding energy of lowest energy interlayer excitons is only $\sim$ 20\% lower due to the weaker screening of the Coulomb interaction between layers of the HBLs. Therefore, it can be deduced that the spectral positions of the interlayer excitons with respect to intralayer ones are mostly determined by the band offset of the constituent single-layers. By comparing oscillator strengths and thermal occupation factors, we show that in luminescence at low temperature, the interlayer exciton peak becomes dominant, while in absorption it is almost invisible.Comment: 17 pages, 4 figure

Diffractive paths for weak localization in quantum billiards

We study the weak localization effect in quantum transport through a clean ballistic cavity with regular classical dynamics. We address the question which paths account for the suppression of conductance through a system where disorder and chaos are absent. By exploiting both quantum and semiclassical methods, we unambiguously identify paths that are diffractively backscattered into the cavity (when approaching the lead mouths from the cavity interior) to play a key role. Diffractive scattering couples transmitted and reflected paths and is thus essential to reproduce the weak-localization peak in reflection and the corresponding anti-peak in transmission. A comparison of semiclassical calculations featuring these diffractive paths yields good agreement with full quantum calculations and experimental data. Our theory provides system-specific predictions for the quantum regime of few open lead modes and can be expected to be relevant also for mixed as well as chaotic systems.Comment: 5 pages, 3 figures, final version with extended discussion and added reference

Medicine without borders: a literature review of short-term international medical missions

AbstractBackgroundEach year, medical providers and trainees travel to low-income and middle-income countries to deliver direct medical care via short-term medical missions (STMMs) lasting between 1 day and 2 years. In spite of the high prevalence of STMMs, little aggregate information exists about where STMMs go, the services they deliver, and their relationship to the recipient country's health-care system. Our objective was to review the literature on STMMs to better understand their characteristics and identify how they link to the in-country health system.MethodsWe searched MEDLINE-indexed articles on STMMs published between January, 2010, and August, 2014. Exclusion criteria included publications with exclusive focus on medical school curricula, commentaries, and publications on military or disaster medicine. Of 1538 identified articles, 152 met our criteria. Data extracted from the full text of the eligible articles included article type, subject, and STMM details such as location and duration.FindingsNearly half of all articles (72 [47%]) described one or more specific STMMs without any evaluation of the STMM's work; 48 (32%) broadly discussed the concept of STMMs (eg, ethics, best practices); and 32 (21%) evaluated some aspect of an STMM, such as cost-effectiveness or post-operative complication rates. Most articles focused on the implementation of STMMs (66 [43%]), personal experiences of STMMs (36 [24%]), or ethical issues (23 [15%]). Data from 102 articles that detailed an STMM reveal that most medical teams came from the USA, and most STMMs went to Latin America (42 [42%]) or sub-Saharan Africa (34 [34%]). About 40% of articles (41) explicitly state that students were involved in the STMM. About a third (36 [35%]) of these articles did not specify how long the STMM lasted, and approximately half (53[52%]) did not specify how many people were involved in the STMM. Most publications also lacked essential details about STMMs' link to the destination countries' existing health systems. There was little description of the local health needs or how the STMM would affect local health-care delivery, either favourably or unfavourably.InterpretationPublished articles suggest that the prevalence of international STMMs is on the rise. However, very few publications include rigorous evaluation of the services rendered or describe how STMMs link to the recipient country's health-care system.FundingNone

Exchange on the Nixon Administration and the Vietnam War

Dialog about a book review

Quantum interference effects in resonant Raman spectroscopy of single- and triple-layer MoTe2_2 from first principles

We present a combined experimental and theoretical study of resonant Raman spectroscopy in single- and triple-layer MoTe$_2$. Raman intensities are computed entirely from first principles by calculating finite differences of the dielectric susceptibility. In our analysis, we investigate the role of quantum interference effects and the electron-phonon coupling. With this method, we explain the experimentally observed intensity inversion of the $A^\prime_1$ vibrational modes in triple-layer MoTe2 with increasing laser photon energy. Finally, we show that a quantitative comparison with experimental data requires the proper inclusion of excitonic effects.Comment: Main Text (5 Figures, 1 Tables) + Supporting Information (6 Figures