386 research outputs found

    Basement structure and its influence on the structural configuration of the northern North Sea

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    The northern North Sea rift basin developed on a heterogeneous crust comprising structures inherited from the Caledonian orogeny and Devonian postorogenic extension. Integrating two-dimensional regional seismic reflection data and information from basement wells, we investigate the prerift structural configuration in the northern North Sea rift. Three seismic facies have been defined below the base rift surface: (1) relatively low-amplitude and low-frequency reflections, interpreted as pre-Caledonian metasediments, Caledonian nappes, and/or Devonian clastic sediments; (2) packages of high-amplitude dipping reflections (>500 ms thick), interpreted as basement shear zones; and (3) medium-amplitude and high-frequency reflections interpreted as less sheared crystalline basement of Proterozoic and Paleozoic (Caledonian) origin. Some zones of Seismic Facies 2 can be linked to onshore Devonian shear zones, whereas others are restricted to the offshore rift area. Interpreted offshore shear zones dip S, ESE, and WNW in contrast to W to NW dipping shear zones onshore West Norway. Our results indicate that Devonian strain and ductile deformation was distributed throughout the Caledonian orogenic belt from central South Norway to the Shetland Platform. Most of the Devonian basins related to this extension are, however, removed by erosion during subsequent exhumation. Basement shear zones reactivated during the rifting and locally control the location and geometry of rift depocenters, e.g., in the Stord and East Shetland basins. Prerift structures with present-day dips >15° were reactivated, although some of the basement shear zones are displaced by rift faults regardless of their orientation relative to rift extension direction

    Change in bone mineral density in post menopausal women with rheumatoid arthritis

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    Introduction: Low bone mass is a serious complication of post menopausal women with rheumatoid arthritis. We determined the Change in Bone Mineral Density in postmenopausal women with rheumatoid arthritis. Methods: This retrospective cohort study was carried out on consecutive postmenopausal women with rheumatoid arthritis who were referred to the Azar 5th teaching hospital affiliated to Golestan University of Medical Sciences, North of Iran in 2009. The required data were gathered from the patients' medical records. The data were analyzed using SPSS software and statistical tests. Results: We studied 98 postmenopausal women with rheumatoid arthritis. Mean number of years since menopause and mean duration of disease were 9.39 and 5.13 respectively. T Score mean in femoral neck and lumbar spines was -1.45±1.26 and -2.45±1.44 respectively. The overall prevalence of osteoporosis at both the lumbar spine and femoral neck was 13.3. We have found a significant correlation between age, duration of disease, duration of menopause and bone mineral density (P-Value<0.01). Conlusion: Our results indicate a negative effect of age, number of years since menopause and duration of disease on bone mineral density. So, BMD should be measured in high risk women prior to the implementation of any treatment or prevention program

    The effect of dietary nucleotide on the haematological and serum biochemical parameters of Persian sturgeon (Acipenser persicus) juveniles

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    This study was aimed to examine the impact of different levels of dietary nucleotides (Vannagen) on serum biochemical and blood parameters of Persian sturgeon (Acipenser persicus). Fish (42.37± 2.12 g and 23.67± 0.61 cm) were divided into four treatments with different levels of dietary nucleotides (0, 0.25, 0.35 and 0.5 percent of diet). There were three replicates with a density of 12 fish per tank. After 10 weeks of feeding, serum biochemical and blood parameters were measured. Among the measured factors, blood glucose, triglycerides, cholesterol, erythrocyte and heterophil showed significant differences between the groups fed with nucleotides and the control group (P ≤ 0.05). By increasing the nucleotide levels, the mean heterophil and serum glucose showed significant increase and decrease, respectively. The highest and lowest values of cholesterol and triglyceride were found in groups fed with 0.25% and 0.35% nucleotides, respectively. The other measured factors had no significant difference (P≤0.05). Therefore, it could be said that with regard to the limited capacity of cells to synthesize nucleotides, external preparing of nucleotides could result in the production of needed nucleotides and an increase of its production speed, especially during stress. Such preparation can also improve fish physiology and health status

    Dynamic soil-structure interaction analysis using the scaled boundary finite-element method.

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    This thesis presents the development of a reliable and efficient technique for the numerical simulation of dynamic soil-structure interaction problems in anisotropic and nonhomogeneous unbounded soils of arbitrary geometry. Such a technique is indispensable in the seismic analysis of large-scale engineering constructions and, to my best knowledge, does not exist at present. The theoretical framework of the research is based on the scaled boundary finite-element method. The following advances are achieved: The scaled boundary finite-element method is extended to simulate the dynamic response of non-homogeneous unbounded domains. The scaled boundary finite element equations in the frequency and time domains are derived for power-type non-homogeneity frequently employed in geotechnical engineering. A high-frequency asymptotic expansion of the dynamic-stiffness matrix is developed. The frequency domain analysis is performed by integrating the scaled boundary finite-element equation in dynamic stiffness. In the time domain, the scaled boundary finite-element equation including convolution integrals is solved for the unit-impulse response at discrete time stations. A Padé series solution for the scaled boundary finite-element equation in dynamic stiffness is developed. It converges over the whole frequency range as the order of the approximation increases. The computationally expensive task of numerically integrating the scaled boundary finite-element equation is circumvented. Exploiting the sparsity of the coefficientmatrices in the scaled boundary finite-element equation leads to a significant reduction in computer time and memory requirements for solving large-scale problems. Furthermore, lumped coefficient matrices are obtained by adopting the auss-Lobatto-Legendre shape functions with nodal quadrature, which avoids the eigenvalue problem in determining the asymptotic expansion. A high-order local transmitting boundary constructed from a continued-fraction solution of the dynamic-stiffness matrix is developed. An equation of motion as occurring in standard structural dynamics with symmetric and frequency-independent coefficient matrices is obtained. This transmitting boundary condition can be coupled seamlessly with standard finite elements. Transient responses are evaluated by using a standard timeintegration scheme. The expensive task of evaluating convolution integrals is circumvented. The advances developed in this thesis are applicable in other disciplines of engineering and science to the analysis of scalar and vector waves in unbounded media

    Risk assessment of drug management process in women surgery department of qaem educational hospital (QEH) using HFMEA method (2013)

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    Evaluation and improvement of drug management process are essential for patient safety. The present study was performed whit the aim of assessing risk of drug management process in Women Surgery Department of QEH using HFMEA method in 2013. A mixed method was used to analyze failure modes and their effects with HFMEA. To classify failure modes; nursing errors in clinical management model, for classifying factors affecting error; approved model by the UK National Health System, and for determining solutions for improvement; Theory of Inventive Problem Solving, were used. 48 failure modes were identified for 14 sub-process of five steps drug management process. The frequency of failure modes were as follow:35.3 in supplying step, 20.75 in prescription step, 10.4 in preparing step, 22.9 in distribution step and 10.35 in follow up and monitoring step. Seventeen failure modes (35.14) were considered as non-acceptable risk (hazard score� 8) and were transferred to decision tree. Among 51 Influencing factors, the most common reasons for error were related to environmental factors (21.5), and the less common reasons for error were related to patient factors (4.3). HFMEA is a useful tool to evaluating, prioritization and analyzing failure modes in drug management process. Revision drug management process based focus-PDCA, assessing adverse drug reactions (ADR), USE patient identification bracelet, holding periodical pharmaceutical conferences to improve personnel knowledge, patient contribution in drug therapy; are performance solutions which were placed in work order. © 2015 by School of Pharmac

    Genetic and epigenetic contribution to astrocytic gliomas pathogenesis

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    Astrocytic gliomas are the most common and lethal form of intracranial tumors. These tumors are characterized by a significant heterogeneity in terms of cytopathological, transcriptional, and (epi)genomic features. This heterogeneity has made these cancers one of the most challenging types of cancers to study and treat. To uncover these complexities and to have better understanding of the disease initiation and progression, identification, and characterization of underlying cellular and molecular pathways related to (epi)genetics of astrocytic gliomas is crucial. Here, we discuss and summarize molecular and (epi)genetic mechanisms that provide clues as to the pathogenesis of astrocytic gliomas. (Figure presented.). © 2018 International Society for Neurochemistr

    Genetic and epigenetic contribution to astrocytic gliomas pathogenesis

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    Astrocytic gliomas are the most common and lethal form of intracranial tumors. These tumors are characterized by a significant heterogeneity in terms of cytopathological, transcriptional, and (epi)genomic features. This heterogeneity has made these cancers one of the most challenging types of cancers to study and treat. To uncover these complexities and to have better understanding of the disease initiation and progression, identification, and characterization of underlying cellular and molecular pathways related to (epi)genetics of astrocytic gliomas is crucial. Here, we discuss and summarize molecular and (epi)genetic mechanisms that provide clues as to the pathogenesis of astrocytic gliomas. (Figure presented.). © 2018 International Society for Neurochemistr
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