297 research outputs found

    Application of amorphous carbon based materials as antireflective coatings on crystalline silicon solar cells

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)We report on the investigation of the potential application of different forms of amorphous carbon (a-C and a-C:H) as an antireflective coating for crystalline silicon solar cells. Polymeric-like carbon (PLC) and hydrogenated diamond-like carbon films were deposited by plasma enhanced chemical vapor deposition. Tetrahedral amorphous carbon (ta-C) was deposited by the filtered cathodic vacuum arc technique. Those three different amorphous carbon structures were individually applied as single antireflective coatings on conventional (polished and texturized) p-n junction crystalline silicon solar cells. Due to their optical properties, good results were also obtained for double-layer antireflective coatings based on PLC or ta-C films combined with different materials. The results are compared with a conventional tin dioxide (SnO(2)) single-layer antireflective coating and zinc sulfide/magnesium fluoride (ZnS/MgF(2)) double-layer antireflective coatings. An increase of 23.7% in the short-circuit current density, J(sc), was obtained using PLC as an antireflective coating and 31.7% was achieved using a double-layer of PLC with a layer of magnesium fluoride (MgF(2)). An additional increase of 10.8% was obtained in texturized silicon, representing a total increase (texturization + double-layer) of about 40% in the short-circuit current density. The potential use of these materials are critically addressed considering their refractive index, optical bandgap, absorption coefficient, hardness, chemical inertness, and mechanical stability. (C) 2011 American Institute of Physics. [doi:10.1063/1.3622515]1104Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Brazilian financial research agency MCTConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Fulfillment of the Brazilian Agenda of Priorities in Health Research

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    This commentary describes how the Brazilian Ministry of Health's (MoH) research support policy fulfilled the National Agenda of Priorities in Health Research (NAPHR). In 2003, the MoH started a democratic process in order to establish a priority agenda in health research involving investigators, health managers and community leaders. The Agenda was launched in 2004 and is guiding budget allocations in an attempt to reduce the gap between scientific knowledge and health practice and activities, aiming to contribute to improving Brazilian quality of life. Many strategies were developed, for instance: Cooperation Agreements between the Ministry of Health and the Ministry of Science and Technology; the decentralization of research support at state levels with the participation of local Health Secretariats and Science and Technology Institutions; Health Technology Assessment; innovation in neglected diseases; research networks and multicenter studies in adult, women's and children's health; cardiovascular risk in adolescents; clinical research and stem cell therapy. The budget allocated by the Ministry of Health and partners was expressive: US$419 million to support almost 3,600 projects. The three sub-agenda with the higher proportion of resources were "industrial health complex", "clinical research" and "communicable diseases", which are considered strategic for innovation and national development. The Southeast region conducted 40.5% of all projects and detained 59.7% of the resources, attributable to the concentration of the most traditional health research institutes and universities in the states of São Paulo and Rio de Janeiro. The second most granted region was the Northeast, which reflects the result of a governmental policy to integrate and modernize this densely populated area and the poorest region in the country. Although Brazil began the design and implementation of the NAPHR in 2003, it has done so in accordance with the 'good practice principles' recently published: inclusive process, information gathering, careful planning and funding policy, transparency and internal evaluation (an external independent evaluation is underway). The effort in guiding the health research policy has achieved and legitimated an unprecedented developmental spurt to support strategic health research. We believe this experience is valuable and applicable to other countries, but different settings and local political circumstances will determine the best course of action to follow

    Evolution of High Trophic Diversity Based on Limited Functional Disparity in the Feeding Apparatus of Marine Angelfishes (f. Pomacanthidae)

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    The use of biting to obtain food items attached to the substratum is an ecologically widespread and important mode of feeding among aquatic vertebrates, which rarely has been studied. We did the first evolutionary analyses of morphology and motion kinematics of the feeding apparatus in Indo-Pacific members of an iconic family of biters, the marine angelfishes (f. Pomacanthidae). We found clear interspecific differences in gut morphology that clearly reflected a wide range of trophic niches. In contrast, feeding apparatus morphology appeared to be conserved. A few unusual structural innovations enabled angelfishes to protrude their jaws, close them in the protruded state, and tear food items from the substratum at a high velocity. Only one clade, the speciose pygmy angelfishes, showed functional departure from the generalized and clade-defining grab-and-tearing feeding pattern. By comparing the feeding kinematics of angelfishes with wrasses and parrotfishes (f. Labridae) we showed that grab-and-tearing is based on low kinematics disparity. Regardless of its restricted disparity, the grab-and-tearing feeding apparatus has enabled angelfishes to negotiate ecological thresholds: Given their widely different body sizes, angelfishes can access many structurally complex benthic surfaces that other biters likely are unable to exploit. From these surfaces, angelfishes can dislodge sturdy food items from their tough attachments. Angelfishes thus provide an intriguing example of a successful group that appears to have evolved considerable trophic diversity based on an unusual yet conserved feeding apparatus configuration that is characterized by limited functional disparity

    Evidence for an association of HLA-DRB1*15 and DRB1*09 with leprosy and the impact of DRB1*09 on disease onset in a Chinese Han population

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    <p>Abstract</p> <p>Background</p> <p>Human leukocyte antigens (HLAs) have been proposed to modulate the immune response to <it>Mycobacterium leprae</it>. The association of HLA-DRB1 with leprosy has been reported in several populations, but not in a Chinese population.</p> <p>Methods</p> <p>The polymerase chain reaction-sequence-specific oligonucleotide probe with Luminex100 (PCR-SSOP-Luminex) method was used to genotype HLA-DRB1 alleles in 305 leprosy patients and 527 healthy control individuals.</p> <p>Results</p> <p>The HLA-DRB1*15 allele was significantly more prevalent among leprosy patients than healthy controls, whereas the frequency of the HLA-DRB1*09 allele was lower among leprosy patients, especially those with early-onset disease.</p> <p>Conclusion</p> <p>HLA-DRB1 alleles are associated with leprosy susceptibility in a Chinese population. The HLA-DRB1*09 allele was found to be protective exclusively in a subset of early-onset leprosy patients.</p

    Prostatic Artery Embolization as a Primary Treatment for Benign Prostatic Hyperplasia: Preliminary Results in Two Patients

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    Symptomatic benign prostatic hyperplasia (BPH) typically occurs in the sixth and seventh decades, and the most frequent obstructive urinary symptoms are hesitancy, decreased urinary stream, sensation of incomplete emptying, nocturia, frequency, and urgency. Various medications, specifically 5-α-reductase inhibitors and selective α-blockers, can decrease the severity of the symptoms secondary to BPH, but prostatectomy is still considered to be the traditional method of management. We report the preliminary results for two patients with acute urinary retention due to BPH, successfully treated by prostate artery embolization (PAE). The patients were investigated using the International Prostate Symptom Score, by digital rectal examination, urodynamic testing, prostate biopsy, transrectal ultrasound (US), and magnetic resonance imaging (MRI). Uroflowmetry and postvoid residual urine volume complemented the investigation at 30, 90, and 180 days after PAE. The procedure was performed under local anesthesia; embolization of the prostate arteries was performed with a microcatheter and 300- to 500-μm microspheres using complete stasis as the end point. One patient was subjected to bilateral PAE and the other to unilateral PAE; they urinated spontaneously after removal of the urethral catheter, 15 and 10 days after the procedure, respectively. At 6-month follow-up, US and MRI revealed a prostate reduction of 39.7% and 47.8%, respectively, for the bilateral PAE and 25.5 and 27.8%, respectively, for the patient submitted to unilateral PAE. The early results, at 6-month follow-up, for the two patients with BPH show a promising potential alternative for treatment with PAE
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