44 research outputs found

    Reliability Exercise of Ultrasound Salivary Glands in Sjögren's Disease:An International Web Training Initiative

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    INTRODUCTION: Major salivary gland ultrasonography (SGUS) demonstrated its good metric properties as an outcome measure for diagnosing primary Sjögren's disease (SD). The objective was to assess SGUS reliability among sonographers with different levels of experience, using web training.METHODS: Sonographers from expert centers participated in the reliability exercise. Before exercises, training was done by videoconferencing. Reliability of the two most experienced sonographers (MES) was assessed and then compared to other sonographers. Intra-reader and inter-reader reliability of SGUS items were assessed by computing Cohen's κ coefficients.RESULTS: All sets were read twice by all 14 sonographers within a 4-month interval. Intra-reader reliability of MES was almost perfect for homogeneity, substantial for Outcome Measures in Rheumatology (OMERACT) scoring system (OMERACTss). Among LES (less experienced sonographers), reliability was moderate to almost perfect for homogeneity, fair to moderate for OMERACTss, and fair to almost perfect for binary OMERACTss. Inter-reader reliability between MES was almost perfect for homogeneity, substantial for diagnosis, moderate for OMERACTss, and substantial for binary OMERACTss. Compared to MES, reliabilities of LES were moderate to almost perfect for both homogeneity and diagnosis, only fair to moderate for OMERACTss, but increased in binary OMERACTss.CONCLUSIONS: Videoconferencing training sessions in an international reliability exercise could be an excellent tool to train experienced and less-experienced sonographers. SGUS homogeneity items is useful to distinguish normal from abnormal salivary glands parenchyma independently of diagnosis. Structural damage evaluations by OMERACT scoring system is a new comprehensive score to diagnose patients with SD and could be easily used by sonographers in a binary method.</p

    The deuteron: structure and form factors

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    A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic

    Properties of Graphene: A Theoretical Perspective

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    In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theoretical models. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodynamic properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect, and optical properties. Confinement of electrons in graphene is nontrivial due to Klein tunneling. We review various theoretical and experimental studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane -- gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic

    Pulmonary tuberculosis among people living with HIV/AIDS attending care and treatment in rural northern Tanzania

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    Tuberculosis is the commonest opportunistic infection and the number one cause of death in HIV/AIDS patients in developing countries. To address the extent of the tuberculosis HIV coinfection in rural Tanzania we conducted a cross sectional study including HIV/AIDS patients attending care and treatment clinic from September 2006 to March 2007. Sputum samples were collected for microscopy, culture and drug susceptibility testing. Chest X-ray was done for those patients who consented. Blood samples were collected for CD4+ T cells count. The prevalence of tuberculosis was 20/233 (8.5%). Twenty (8.5%) sputum samples were culture positive. Eight of the culture positive samples (40%) were smear positive. Fifteen (75%) of these patients neither had clinical symptoms nor chest X-ray findings suggestive of tuberculosis. Nineteen isolates (95%) were susceptible to rifampicin, isoniazid, streptomycin and ethambutol (the first line tuberculosis drugs). One isolate (5%) from HIV/tuberculosis coinfected patients was resistant to isoniazid. No cases of multi- drug resistant tuberculosis were identified. We found high prevalence of tuberculosis disease in this setting. Chest radiograph suggestive of tuberculosis and clinical symptoms of fever and cough were uncommon findings in HIV/tuberculosis coinfected patients. Tuberculosis can occur at any stage of CD4+T cells depletion

    Predictors of mortality in HIV-infected patients starting antiretroviral therapy in a rural hospital in Tanzania

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    \ud \ud Studies of antiretroviral therapy (ART) programs in Africa have shown high initial mortality. Factors contributing to this high mortality are poorly described. The aim of the present study was to assess mortality and to identify predictors of mortality in HIV-infected patients starting ART in a rural hospital in Tanzania. This was a cohort study of 320 treatment-naïve adults who started ART between October 2003 and November 2006. Reliable CD4 cell counts were not available, thus ART initiation was based on clinical criteria in accordance with WHO and Tanzanian guidelines. Kaplan-Meier models were used to estimate mortality and Cox proportional hazards models to identify predictors of mortality. Patients were followed for a median of 10.9 months (IQR 2.9-19.5). Overall, 95 patients died, among whom 59 died within 3 months of starting ART. Estimated mortality was 19.2, 29.0 and 40.7% at 3, 12 and 36 months, respectively. Independent predictors of mortality were severe anemia (hemoglobin <8 g/dL; adjusted hazard ratio [AHR] 9.20; 95% CI 2.05-41.3), moderate anemia (hemoglobin 8-9.9 g/dL; AHR 7.50; 95% CI 1.77-31.9), thrombocytopenia (platelet count <150 x 109/L; AHR 2.30; 95% CI 1.33-3.99) and severe malnutrition (body mass index <16 kg/m2; AHR 2.12; 95% CI 1.06-4.24). Estimated one year mortality was 55.2% in patients with severe anemia, compared to 3.7% in patients without anemia (P < 0.001). Mortality was found to be high, with the majority of deaths occurring within 3 months of starting ART. Anemia, thrombocytopenia and severe malnutrition were strong independent predictors of mortality. A prognostic model based on hemoglobin level appears to be a useful tool for initial risk assessment in resource-limited settings.\u

    Effects of Combined Ketamine/Xylazine Anesthesia on Light Induced Retinal Degeneration in Rats

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    Objectives: To explore the effect of ketamine-xylazine anesthesia on light-induced retinal degeneration in rats. Methods: Rats were anesthetized with ketamine and xylazine (100 and 5 mg, respectively) for 1 h, followed by a recovery phase of 2 h before exposure to 16,000 lux of environmental illumination for 2 h. Functional assessment by electroretinography (ERG) and morphological assessment by in vivo imaging (optical coherence tomography), histology (hematoxylin/eosin staining, TUNEL assay) and immunohistochemistry (GFAP and rhodopsin staining) were performed at baseline (ERG), 36 h, 7 d and 14 d post-treatment. Non-anesthetized animals treated with light damage served as controls. Results: Ketamine-xylazine pre-treatment preserved retinal function and protected against light-induced retinal degeneration. In vivo retinal imaging demonstrated a significant increase of outer nuclear layer (ONL) thickness in the non-anesthetized group at 36 h (p,0.01) and significant reduction one week (p,0.01) after light damage. In contrast, ketamine-xylazine pre-treated animals showed no significant alteration of total retinal or ONL thickness at either time point (p.0.05), indicating a stabilizing and/or protective effect with regard to phototoxicity. Histology confirmed light-induced photoreceptor cell death and Müller cells gliosis in non-anesthetized rats, especially in the superior hemiretina, while ketamine-xylazine treated rats showed reduced photoreceptor cell death (TUNEL staining: p,0.001 after 7 d), thicker ONL and longer IS/OS. Fourteen days after light damage, a reduction of standard flash induced a-wave amplitudes and a-wav

    Moving carbon between spheres, the potential oxalate-carbonate pathway of Brosimum alicastrum Sw.; Moraceae.

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    Aims The Oxalate-Carbonate Pathway (OCP) is a biogeochemical process that transfers atmospheric CO2 into the geologic reservoir as CaCO3; however, until now all investigations on this process have focused on species with limited food benefits. This study evaluates a potential OCP associated with Brosimum alicastrum, a Neotropical species with agroforestry potential (ca. 70–200 kg-nuts yr−1), in the calcareous soils of Haiti and Mexico. Methods / results Enzymatic analysis demonstrated significant concentrations of calcium oxalate (5.97 % D.W.) were associated with B. alicastrum tissue in all sample sites. The presence of oxalotrophism was also confirmed with microbiological analyses in both countries. High concentrations of total calcium (>7 g kg−1) and lithogenic carbonate obscured the localised alkalinisation and identification of secondary carbonate associated with the OCP at most sample sites, except Ma Rouge, Haiti. Soils adjacent to subjects in Ma Rouge demonstrated an increase in pH (0.63) and CaCO3 concentration (5.9 %) that, when coupled with root-like secondary carbonate deposits in Mexico, implies that the OCP does also occur in calcareous soils. Conclusions Therefore this study confirms that the OCP also occurs in calcareous soils, adjacent to B. alicastrum, and could play a fundamental and un-accounted role in the global calcium-carbon coupled cycle

    Malnutrition in patients treated for oral or oropharyngeal cancer—prevalence and relationship with oral symptoms: an explorative study

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    This study aimed to assess prevalence of malnutrition after treatment for oral/oropharyngeal cancer and to explore how oral symptoms relate to malnutrition after treatment. In this cross-sectional study, malnutrition (weight loss a parts per thousand yenaEuro parts per thousand 10% in 6 months or a parts per thousand yen5% in 1 month), oral symptoms (EORTC QLQ-H&N35 questionnaire and additional questions to assess chewing problems), dental status, trismus and dietary intake were assessed in 116 adult patients treated for oral/oropharyngeal cancer. Prevalence of malnutrition was 16% (95%CI: 10% to 23%). Prevalence of malnutrition in the period 0-3 months after treatment was significantly higher (25%) than in the periods > 3-12 months (13%) and > 12-36 months after treatment (3%, p = 0.008). Logistic multivariate regression analysis revealed that swallowing problems (p = 0.021) and insufficient protein intake were significantly related to malnutrition (p = 0.016). In conclusion, malnutrition is a considerable problem in patients treated for oral/oropharyngeal cancer, shortly after treatment. Of all oral symptoms, only swallowing problems were significantly related to malnutrition in the period after treatment for oral/oropharyngeal cancer
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