5,799 research outputs found

    Orbital textures and charge density waves in transition metal dichalcogenides

    Full text link
    Low-dimensional electron systems, as realized naturally in graphene or created artificially at the interfaces of heterostructures, exhibit a variety of fascinating quantum phenomena with great prospects for future applications. Once electrons are confined to low dimensions, they also tend to spontaneously break the symmetry of the underlying nuclear lattice by forming so-called density waves; a state of matter that currently attracts enormous attention because of its relation to various unconventional electronic properties. In this study we reveal a remarkable and surprising feature of charge density waves (CDWs), namely their intimate relation to orbital order. For the prototypical material 1T-TaS2 we not only show that the CDW within the two-dimensional TaS2-layers involves previously unidentified orbital textures of great complexity. We also demonstrate that two metastable stackings of the orbitally ordered layers allow to manipulate salient features of the electronic structure. Indeed, these orbital effects enable to switch the properties of 1T-TaS2 nanostructures from metallic to semiconducting with technologically pertinent gaps of the order of 200 meV. This new type of orbitronics is especially relevant for the ongoing development of novel, miniaturized and ultra-fast devices based on layered transition metal dichalcogenides

    Challenges and opportunities for implementing integrated mental health care: a district level situation analysis from five low- and middle-income countries.

    Get PDF
    BACKGROUND: Little is known about how to tailor implementation of mental health services in low- and middle-income countries (LMICs) to the diverse settings encountered within and between countries. In this paper we compare the baseline context, challenges and opportunities in districts in five LMICs (Ethiopia, India, Nepal, South Africa and Uganda) participating in the PRogramme for Improving Mental health carE (PRIME). The purpose was to inform development and implementation of a comprehensive district plan to integrate mental health into primary care. METHODS: A situation analysis tool was developed for the study, drawing on existing tools and expert consensus. Cross-sectional information obtained was largely in the public domain in all five districts. RESULTS: The PRIME study districts face substantial contextual and health system challenges many of which are common across sites. Reliable information on existing treatment coverage for mental disorders was unavailable. Particularly in the low-income countries, many health service organisational requirements for mental health care were absent, including specialist mental health professionals to support the service and reliable supplies of medication. Across all sites, community mental health literacy was low and there were no models of multi-sectoral working or collaborations with traditional or religious healers. Nonetheless health system opportunities were apparent. In each district there was potential to apply existing models of care for tuberculosis and HIV or non-communicable disorders, which have established mechanisms for detection of drop-out from care, outreach and adherence support. The extensive networks of community-based health workers and volunteers in most districts provide further opportunities to expand mental health care. CONCLUSIONS: The low level of baseline health system preparedness across sites underlines that interventions at the levels of health care organisation, health facility and community will all be essential for sustainable delivery of quality mental health care integrated into primary care

    First report of venereal and vertical transmission of canine leishmaniosis from naturally infected dogs in Germany

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Canine leishmaniosis (CanL) is a zoonotic disease caused by <it>Leishmania (L.) infantum</it>. It is endemic to several tropical and subtropical countries but also to the Mediterranean region. It is transmitted by phlebotomine sandflies but occasional non-vector transmissions have been reported, including vertical and horizontal transmission.</p> <p>Findings</p> <p>The authors report a case of CanL in a female boxer dog from Dusseldorf, Germany, that had never been in an endemic region. A serum sample from the bitch was tested positive for antibodies against <it>Leishmania </it>(IFAT 1:2,000, ELISA 72). The bitch had whelped three litters, and one puppy from the third litter was also found to be seropositive for <it>Leishmania </it>antibodies (IFAT 1:4,000, ELISA 78).</p> <p>Conclusions</p> <p>Up to now, despite intensive searching, the occurrence of sandflies could not be proved in the bitch's region of origin. Thus, vertical and horizontal transmission are to be discussed as possible ways of infection. This may be the first report of venereal and vertical transmission of <it>L. infantum </it>in naturally infected dogs in Germany.</p

    Antigenicity and diagnostic potential of vaccine candidates in human Chagas disease

    Get PDF
    Chagas disease is the most common cause of congestive heart failure related deaths among young adults in the endemic areas of South and Central America and Mexico. Diagnosis and treatment of T. cruzi infection has remained difficult and challenging after 100 years of its identification. In >95% of human cases, T. cruzi infection remains undiagnosed until several years later when chronic evolution of progressive disease results in clinical symptoms associated with cardiac damage. Diagnosis generally depends on the measurement of T. cruzi'specific antibodies that can result in false positives. A conclusive diagnosis of T. cruzi infection thus often requires multiple serological tests, in combination with epidemiological data and clinical symptoms. In this study, we investigated the antibody response to TcG1, TcG2, and TcG4 in clinically characterized chagasic patients. These antigens were identified as vaccine candidates and shown to elicit protective immunity to T. cruzi and Chagas disease in experimental animals. Our data show the serology test developed using the TcGmix (multiplex ELISA) is a significantly better alternative to epimastigote extracts currently used in T. cruzi serodiagnosis or the trypomastigote lysate used in this study for comparison purposes.Fil: Gupta, Shivali. University Of Texas Medical Branch. Department Of Pathology; Estados UnidosFil: Wan, Xianxu. University Of Texas Medical Branch. Department Of Pathology; Estados UnidosFil: Zago, María Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Patología Experimental; ArgentinaFil: Martinez Sellers, Valena C.. University Of Texas Medical Branch. Department of Pathology; Estados UnidosFil: Silva, Trevor S.. University Of Texas Medical Branch. Department of Pathology; Estados UnidosFil: Assiah, Dadjah. University Of Texas Medical Branch. Department of Pathology; Estados UnidosFil: Dhiman, Monisha. University Of Texas Medical Branch. Department of Pathology; Estados UnidosFil: Nuñez, Sonia. Provincia de Salta. Hospital Público de Gestion Descentralizada San Bernardo; ArgentinaFil: Petersen, John R.. University Of Texas Medical Branch. Department of Pathology; Estados UnidosFil: Vazquez Chagoyán, Juan C.. Universidad Autónoma de Estado de México ; MéxicoFil: Estrada Franco, Jose G.. Universidad Autónoma de Estado de México; MéxicoFil: Garg, Nisha Jain. University Of Texas Medical Branch. Department of Pathology; Estados Unido

    Measuring the Weak Phase gamma in Color Allowed B->DKpi Decays

    Full text link
    We present a method to measure the weak phase gamma in the three-body decay of charged B mesons to the final states D K pi0. These decays are mediated by interfering amplitudes which are color-allowed and hence relatively large. As a result, large CP violation effects that could be observed with high statistical significance are possible. In addition, the three-body decay helps resolve discrete ambiguities that are usually present in measurements of the weak phase. The experimental implications of conducting these measurements with three-body decays are discussed, and the sensitivity of the method is evaluated using a simulation.Comment: 18 pages, LaTex, 15 eps and ps figure

    Transplacental Transmission of Leishmania infantum as a Means for Continued Disease Incidence in North America

    Get PDF
    Dogs are a favored feeding source for sand flies that transmit human L. infantum infection. Zoonotic visceral leishmaniasis (ZVL) is an emerging problem in some U.S. dog breeds, with over 20% of at-risk Foxhounds infected. Although classically Leishmania is transmitted by infected sand flies which exist in the United States, no role has yet been determined for vector-borne transmission. Means of ongoing L. infantum transmission in U.S. dogs is unknown. Possibilities include transplacental and horizontal/venereal transmission. Aims for this study were to establish whether transplacental transmission occurred in Leishmania-infected U.S. dogs and determine the effect of this transmission on immune recognition of Leishmania. This novel report describes wide-spread infection as identified by kqPCR in 8 day-old pups born to a naturally-infected, seropositive U.S. dog with no travel history. This is the first report of transplacental transmission of L. infantum in naturally-infected dogs in North America. Evidence that mom-to-pup transmission of ZVL may continue disease in an otherwise non-endemic region has significant implications on current control strategies for ZVL. Determining frequency of vertical transmission and incorporating canine sterilization with vector control may have a more significant impact on ZVL transmission to people in endemic areas than current control efforts

    Measurement of the J/Psi Production Cross Section in 920 GeV/c Fixed-Target Proton-Nucleus Interactions

    Get PDF
    The mid-rapidity (dsigma_(pN)/dy at y=0) and total sigma_(pN) production cross sections of J/Psi mesons are measured in proton-nucleus interactions. Data collected by the HERA-B experiment in interactions of 920 GeV/c protons with carbon, titanium and tungsten targets are used for this analysis. The J/Psi mesons are reconstructed by their decay into lepton pairs. The total production cross section obtained is sigma_(pN)(J/Psi) = 663 +- 74 +- 46 nb/nucleon. In addition, our result is compared with previous measurements

    From theoretical concepts to policies and applied programmes: the landscape of integration of oral health in primary care

    Full text link
    Background: Despite its importance, the integration of oral health into primary care is still an emerging practice in the field of health care services. This scoping review aims to map the literature and provide a summary on the conceptual frameworks, policies and programs related to this concept. Methods: Using the Levac et al. six-stage framework, we performed a systematic search of electronic databases, organizational websites and grey literature from 1978 to April 2016. All relevant original publications with a focus on the integration of oral health into primary care were retrieved. Content analyses were performed to synthesize the results. Results: From a total of 1619 citations, 67 publications were included in the review. Two conceptual frameworks were identified. Policies regarding oral heath integration into primary care were mostly oriented toward common risk factors approach and care coordination processes. In general, oral health integrated care programs were designed in the public health sector and based on partnerships with various private and public health organizations, governmental bodies and academic institutions. These programmes used various strategies to empower oral health integrated care, including building interdisciplinary networks, training nondental care providers, oral health champion modelling, enabling care linkages and care coordinated process, as well as the use of e-health technologies. The majority of studies on the programs outcomes were descriptive in nature without reporting long-term outcomes. Conclusions: This scoping review provided a comprehensive overview on the concept of integration of oral health in primary care. The findings identified major gaps in reported programs outcomes mainly because of the lack of related research. However, the results could be considered as a first step in the development of health care policies that support collaborative practices and patient-centred care in the field of primary care sector
    • …
    corecore