894 research outputs found

    Stent-armed kyphoplasty in osteoporotic thoracolumbar fractures—clinical and functional results and a center experience over 10 years

    Get PDF
    Background: The optimal treatment of osteoporotic vertebral fractures is still a controversial and under discussion topic. Armed kyphoplasty with expansive intravertebral implants is an emerging procedure, which, in theory, it not only makes it possible to achieve instant analgesia, and to get stabilization gains of benefits of kyphoplasty and vertebroplasty, but also, allows for a more effective maintenance of the restored vertebral height. Methods: A retrospective observational study is presented, in which 30 patients participated, including a total of 33 osteoporotic thoracolumbar compression burst vertebral fractures with involvement of one or both vertebral platforms and of more than one fifth of the posterior wall. These individuals underwent armed kyphoplasty with VBS® stents (or stentoplasty) filled with bone cement over 10 years (between 2012 and 2022) at the same center. Clinical (visual analogue scale, Oswestry Disability Index and Patient Global Impression of Change) and imaging results (restoration and maintenance of vertebral body heights) achieved were investigated. The mean follow-up time was 4.5 years (range, 1-10 years). Results: There was a statistically significant improvement in all clinical and functional parameters evaluated, as well as a statistically significant difference in the various vertebral body heights between preoperative and end of follow-up time [increase of 10.7-15.2-5.0 mm (anterior-median-posterior) in the sagittal plane and 6.7-11.6-9.7 mm (right-median-left) in the coronal plane]. There was a statistically significant direct correlation between vertebral heights in the coronal plane, and between the Beck index assessed at the end of the follow-up period and the improvement in functional disability. Conclusions: The percutaneous transpedicular posterior approach, the ability to anatomically restore the fractured vertebra and to maintain it in the medium-long term, as well as the reduced risk of adverse effects, make stent-armed kyphoplasty a very attractive treatment option for osteoporotic compressive thoracolumbar fractures. A clinical-morphological correlation was demonstrated regarding the surgical treatment of these fractures, it was found that a more effective morphological restoration of vertebral heights in both the sagittal and coronal planes is associated with superior satisfactory clinical functional parameters.info:eu-repo/semantics/publishedVersio

    Black-pigmented anaerobic bacteria associated with ovine periodontitis

    Get PDF
    Periodontitis is a polymicrobial infectious disease that causes occlusion change, tooth loss, difficulty in rumination, and premature culling of animals. This study aimed to detect species of the genera Porphyromonas and Prevotella present in the periodontal pocket of sheep with lesions deeper than 5mm (n=14) and in the gingival sulcus of animals considered periodontally healthy (n=20). The presence of microorganisms was evaluated by polymerase chain reaction (PCR) using specific primers for Porphyromonas asaccharolytica, Porphyromonas endodontalis, Porphyromonas gingivalis, Porphyromonas gulae, Prevotella buccae, Prevotella intermedia, Prevotella loescheii, Prevotella melaninogenica, Prevotella nigrescens, Prevotella oralis, and Prevotella tannerae. Prevalence and risk analysis were performed using Student's t-test and Spearman's correlation. Among the Prevotella and Porphyromonas species detected in the periodontal lesions of sheep, P. melaninogenica (85.7%), P. buccae (64.3%), P. gingivalis (50%), and P. endodontalis (50%) were most prevalent. P. gingivalis (15%) and P. oralis (10%) prevailed in the gingival sulcus. P. gulae and P. tannerae were not detected in the 34 samples studied. Data evaluation by t-test verified that occurrence of P. asaccharolytica, P. endodontalis, P. gingivalis, P. buccae, P. intermedia, P. melalinogenica, and P. nigrescens correlated with sheep periodontitis. The findings of this study will be an important contribution to research on pathogenesis of sheep periodontitis and development of its control measures

    Traversable Casimir Wormholes in D Dimensions

    Full text link
    In this paper, we study Casimir wormholes in arbitrary spacetime dimensions D. Wormholes require negative energy, and therefore an exotic matter source. Since Casimir energy is negative, it has been speculated as a good candidate to source that objects a long time ago. However only very recently a full solution has been found by Garattini [1]. The author found an appropriate redshift function and proved that in four-dimensional spacetime, the Casimir energy can be a source of traversable wormholes. Soon later Alencar et al have shown, in [2], that this is not true in D = 3 and additional sources must be considered. In this paper, we show that Casimir energy can be a source of the Morris-Thorne wormhole for all spacetime dimensions with D > 3.Comment: 6 pages, 0 figure

    Determination of pesticides in water by liquid chromatography-(Electrospray Ionization)-mass spectrometry (LC-ESI-MS).

    Get PDF
    A method for determination of a selected group of pesticides in water (tap and ground water) was developed using liquid chromatography-(electrospray ionization)-mass spectrometry (LC-ESI-MS). The pesticides dimethoate, carbaryl, simazine, atrazine, ametryne, tebuthiuron, diuron and linuron were isolated using liquid-liquid extraction with dichloromethane and analyzed on a reversed phase column, C-18, with gradient elution at flow rate of 1 mL. min-1. Recoveries ranged from 89% to 112% (R.S.D. <_10%) for tap water and from 76% to 98% (R.S.D <_ 6%) for ground water. The enrichment procedure, followed by use of the selected ion monitoring (SIM) mode gave quantification limits low enough to reach the international legislation level of 0.1 µg.L-1, with a 500-fold preconcentration. The method developed is practical, efficient and reliable for the determination of the selected group of pesticides in the water samples. Um método para a determinação de um grupo selecionado de resíduos de pesticidas em água (de torneira e subterrânea) foi desenvolvido usando cromatografia líquida-ionização electrospray-espectrometria de massas (LC-ESI-MS). Os pesticidas dimetoato, carbaril, simazina, atrazina, ametrina, tebutiuron, diuron e linuron foram isolados usando extração líquido-líquido com diclorometano e analisados em uma coluna de fase reversa, C-18, com eluição gradiente a uma vazão de 1 mL/min. Foram obtidas recuperações de 89 a 112% (RSD <_10%) para água de torneira e 76 a 98% (RSD <_ 6%) para água subterrânea. O procedimento de enriquecimento, seguido pelo uso do monitoramento seletivo de íons (SIM) forneceu limites de quantificação baixos o suficiente para atingir a legislação internacional (Comunidade Européia) que é de 0,1 µg/L. O método desenvolvido é prático, eficiente e confiável para a determinação do grupo selecionado dos pesticidas em amostras de água

    Mudanças ocorridas na composição florística em decorrência da exploração florestal em uma área de floresta de Terra firme na região de Paragominas, PA.

    Get PDF
    O objetivo da presente pesquisa foi avaliar as mudanças ocorridas na composição florística, considerando duas intensidades de colheita de madeira, em 108 ha de floresta, na Fazenda Rio Capim, pertencente à Cikel Brasil Verde Madeiras Ltda., município de Paragominas, Estado do Pará. Os dados foram coletados, em duas ocasiões (2003, antes da exploração e em 2004, após a exploração) em 36 parcelas permanentes quadradas de 0,25 ha, estabelecidas aleatoriamente na área, sendo doze para estudar a floresta não explorada, doze para a explorada com colheita apenas do fuste comercial das árvores e doze para a explorada com colheita do fuste e dos resíduos lenhosos. Todos os indivíduos com DAP > 10 cm foram registrados. Antes da exploração, ocorreram 4469 árvores nas 36 parcelas amostradas (nove hectares), distribuídos em 46 famílias, 138 gêneros e 228 espécies. Após a exploração, foram registrados 4330 indivíduos, porém duas espécies desapareceram (Licaria sp. e Nectandra sp.). A composição florística, nas duas intensidades de colheita, sofreu alterações significantes devido à exploração de impacto reduzido a que foi submetida. Entretanto, não houve alterações significantes entre as duas áreas, demonstrando que, em termos ecológicos, a retirada dos resíduos lenhosos após a colheita dos fustes não implicou em danos significativos à floresta remanescente. Após a exploração, a composição florística, mesmo com pequenas alterações, não mostrou significância entre as três comunidades, sugerindo que com a intensidade de exploração aplicada, mais a retirada adicional dos resíduos, a floresta deve manter suas características bem semelhantes à floresta original, apesar de menos rica no estoque adulto, em termos econômicos
    corecore