142 research outputs found

    Advanced Quantitative Risk Assessment of Offshore Gas Pipeline Systems

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    This research has reviewed the current status of offshore and marine safety. The major problems identified in the research are associated with risk modelling under circumstances where the lack of data or high level of uncertainty exists. This PhD research adopts an object-oriented approach, a natural and straightforward mechanism of organising information of the real world systems, to represent the Offshore Gas Supply Systems (OGSSs) at both the component and system levels. Then based on the object-oriented approach, frameworks of aggregative risk assessment and fault tree analysis are developed. Aggregative risk assessment is to evaluate the risk levels of components, subsystems, and the overall OGSS. Fault trees are then used to represent the cause-effect relationships for a specific risk in the system. Use of these two assessment frameworks can help decision makers to obtain comprehensive view of risks in the OGSS. In order to quantitatively evaluate the framework of aggregative risk, this thesis uses a fuzzy aggregative risk assessment method to determine the risk levels associated with components, subsystems, and the overall OGSS. The fuzzy aggregative risk assessment method is tailored to quantify the risk levels of components, subsystems, and the OGSS. The proposed method is able to identify the most critical subsystem in the OGSS. As soon as, the most critical subsystem is identified, Fuzzy Fault Tree Analysis (FFTA) is employed to quantitatively evaluate the cause-effect relationships for specific undesired event. These results can help risk analysts to select Risk Control Options (RCOs) for mitigating risks in an OGSS. It is not financially possible to employ all the selected RCOs. Therefore, it is necessary to rank and select the best RCO. A decision making method using the Fuzzy TOPSIS (FTOPSIS) is proposed to demonstrate the selection of the best RCOs to control the existing risks in the system. The developed models and frameworks can be integrated to formulate a platform which enables to facilitate risk assessment and safety management of OGSSs without jeopardising the efficiency of OGSSs operations in various situations where traditional risk assessment and safety management techniques cannot be effectively applied

    Seeking safety therapy for co-occurring posttraumatic stress disorder and substance use disorder: A case study in Iran

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    Background: Literature documents the high prevalence of trauma and posttraumatic stress disorder (OTSD) in individuals with substance use disorders, which complicate the clinical profile of patients and present challenges for treatment providers. Although several evidence-based integrated therapies are developed for comorbid PTSD/SUD (substance use disorder), there is a considerable gap addressing this co-occurrence and none of such practices are studied yet on such patients. Through A-B-A single subject design. Objectives: The current study aimed to explore the effectiveness of seeking safety (SS), an integrative evidence-based therapy for PTSD/SUD, to reduce PTSD and SUD symptoms in a 32-year-old female with both disorders. Patients and Methods: Measures of PTSD checklist (PTSD ChecklistCivilian; PCL-C), Addiction Severity Index (ASI), Brief Symptom Inventory (BSI), and Coping Inventory for Stressful Situations (CISS-21) were completed by the participant at baseline, intervention, and 2-month follow-up. Results: Results were analyzed through visual analysis and computing 3 effect size indices including standardized mean difference (SMD), mean baseline reduction (MBLR), and percent of non-overlapping data (PND). Conclusions: Clinically significant reductions in PTSD symptoms, psychological distress, and ASI scores, as well as improvement in coping skills were observed at intervention phase and maintained at 2-month follow-up, which indicated that the participant benefited from SS. © 2018, International Journal of High Risk Behaviors and Addiction

    Leptospirosis mimicking collagen vascular disease in a thirteen-year-old Iranian girl

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    A thirteen-year-old girl from Dezfoul, Iran was referred to our hospital with a history of eight days of high fever, headache, odynophagia, diffuse abdominal and body pain especially limb pain. She then developed conjunctival erythema, transient maculopapular rash on the trunk and also diplopia. No obvious or specific point was shown in the history. In the lab studies, she had very high sedimentation rate (ESR), bandemia and leukocytosis and thrombocytosis with negative results for an array of infectious diseases. Before making a vasculitis diagnosis a microscopic agglutination test for leptospira and then PCR test in blood and stool were requested and revealed to be positive for leptospira. She responded to doxycycline and remained well after one year of follow-up. Leptospirosis should be considered in differential diagnosis of vasculitic syndromes in Iran even for patients from seemingly non-enzootic areas. © 2012, Shahid Beheshti University of Medical Sciencces

    Assessing mastery through psychotherapy: Psychometric properties of the persian version of the mastery scale

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    Background: Considering the importance of assessing the range of phenomena that can change in psychodynamic therapy, and lack of appropriate assessment scale in Persian language, the present study assessed the reliability of the Persian mastery scale. The mastery scale is a comprehensive research tool for assessing a patient's mastery of transference-related interpersonal conflicts during the treatment process. Objectives: The aim of this research was to examine the psychometric properties of the Persian version of the Mastery Scale. Methods: After preparing the Persian version of the mastery scale through the forward-backward translation process, a sample of 36 relationship episodes was rated by three independent judges. Data were collected in Mashhad, Iran in 2015. The psychometric properties of the instrument, including inter-rater reliability and test-retest analysis were assessed. Results: The test-retest correlations of the 3 judges were (0.80, 0.91 and 0.95), highly significant at P < 0.0001 and the inter-rater reliability indicated a good level of agreement (The ICC (3, 3) 0.84, 95 CI 0.72, 0.90). Conclusions: The current study has provided evidence that the Persian mastery scale is a reliable instrument for assessing changes in inner capacities and resources through psychodynamic treatments. However, further studies are required to investigate the validity of this scale. ©2018, Iranian Journal of Psychiatry and Behavioral Sciences

    Sex hormone associations with breast cancer risk and the mediation of randomized trial postmenopausal hormone therapy effects

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    Introduction: Paradoxically, a breast cancer risk reduction with conjugated equine estrogens (CEE) and a risk elevation with CEE plus medroxyprogesterone acetate (CEE + MPA) were observed in the Women’s Health Initiative (WHI) randomized controlled trials. The effects of hormone therapy on serum sex hormone levels, and on the association between baseline sex hormones and disease risk, may help explain these divergent breast cancer findings. Methods: Serum sex hormone concentrations were measured for 348 breast cancer cases in the CEE + MPA trial and for 235 cases in the CEE trial along with corresponding pair-matched controls, nested within the WHI trials of healthy postmenopausal women. Association and mediation analyses, to examine the extent to which sex hormone levels and changes can explain the breast cancer findings, were conducted using logistic regression. Results: Following CEE treatment, breast cancer risk was associated with higher concentrations of baseline serum estrogens, and with lower concentrations of sex hormone binding globulin. However, following CEE + MPA, there was no association of breast cancer risk with baseline sex hormone levels. The sex hormone changes from baseline to year 1 provided an explanation for much of the reduced breast cancer risk with CEE. Specifically, the treatment odds ratio (95% confidence interval) increased from 0.71 (0.43, 1.15) to 0.92 (0.41, 2.09) when the year 1 measures were included in the logistic regression analysis. In comparison, the CEE + MPA odds ratio was essentially unchanged when these year 1 measures were included. Conclusions: Breast cancer risk remains low following CEE use among women having favorable baseline sex hormone profiles, but CEE + MPA evidently produces a breast cancer risk for all women similar to that for women having an unfavorable baseline sex hormone profile. These patterns could reflect breast ductal epithelial cell stimulation by CEE + MPA that is substantially avoided with CEE, in conjunction with relatively more favorable effects of either regimen following a sustained period of estrogen deprivation. These findings may have implications for other hormone therapy formulations and routes of delivery. Trial registration clinicaltrials.gov identifier: NCT00000611

    A truncated 14-amino-acid myelin protein-zero-targeting peptide for fluorescence-guided nerve-preserving surgery

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    Background: The occurrence of accidental nerve damage during surgery and the increasing application of image guidance during head-and-neck surgery have highlighted the need for molecular targeted nerve-sparing interventions. The implementation of such interventions relies on the availability of nerve-specific tracers. In this paper, we describe the development of a truncated peptide that has an optimized affinity for protein zero (P0), the most abundant protein in myelin. Methods and Materials: Further C- and N-terminal truncation was performed on the lead peptide Cy5-P0(101-125). The resulting nine Cy5-labelled peptides were characterized based on their photophysical properties, P0 affinity, and in vitro staining. These characterizations were combined with evaluation of the crystal structure of P0, which resulted in the selection of the optimized tracer Cy5-P0(112-125). A near-infrared Cy7-functionalized derivative (Cy7-P0(112-125)) was used to perform an initial evaluation of fluorescence-guided surgery in a porcine model. Results: Methodological truncation of the 26-amino-acid lead compound Cy5-P0(101-125) resulted in a size reduction of 53.8% for the optimized peptide Cy5-P0(112-125). The peptide design and the 1.5-fold affinity gain obtained after truncation could be linked to interactions observed in the crystal structure of the extracellular portion of P0. The near-infrared analogue Cy7-P0(112-125) supported nerve illumination during fluorescence-guided surgery in the head-and-neck region in a porcine model. Conclusions: Methodological truncation yielded a second-generation P0-specific peptide. Initial surgical evaluation suggests that the peptide can support molecular targeted nerve imaging.NWOTTW BGT16141Radiolog

    Fuzzy evidence theory and Bayesian networks for process systems risk analysis

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    YesQuantitative risk assessment (QRA) approaches systematically evaluate the likelihood, impacts, and risk of adverse events. QRA using fault tree analysis (FTA) is based on the assumptions that failure events have crisp probabilities and they are statistically independent. The crisp probabilities of the events are often absent, which leads to data uncertainty. However, the independence assumption leads to model uncertainty. Experts’ knowledge can be utilized to obtain unknown failure data; however, this process itself is subject to different issues such as imprecision, incompleteness, and lack of consensus. For this reason, to minimize the overall uncertainty in QRA, in addition to addressing the uncertainties in the knowledge, it is equally important to combine the opinions of multiple experts and update prior beliefs based on new evidence. In this article, a novel methodology is proposed for QRA by combining fuzzy set theory and evidence theory with Bayesian networks to describe the uncertainties, aggregate experts’ opinions, and update prior probabilities when new evidences become available. Additionally, sensitivity analysis is performed to identify the most critical events in the FTA. The effectiveness of the proposed approach has been demonstrated via application to a practical system.The research of Sohag Kabir was partly funded by the DEIS project (Grant Agreement 732242)

    Venous Graft-Derived Cells Participate in Peripheral Nerve Regeneration

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    Background: Based on growing evidence that some adult multipotent cells necessary for tissue regeneration reside in the walls of blood vessels and the clinical success of vein wrapping for functional repair of nerve damage, we hypothesized that the repair of nerves via vein wrapping is mediated by cells migrating from the implanted venous grafts into the nerve bundle. Methodology/Principal Findings: To test the hypothesis, severed femoral nerves of rats were grafted with venous grafts from animals of the opposite sex. Nerve regeneration was impaired when decellularized or irradiated venous grafts were used in comparison to untreated grafts, supporting the involvement of venous graft-derived cells in peripheral nerve repair. Donor cells bearing Y chromosomes integrated into the area of the host injured nerve and participated in remyelination and nerve regeneration. The regenerated nerve exhibited proper axonal myelination, and expressed neuronal and glial cell markers. Conclusions/Significance: These novel findings identify the mechanism by which vein wrapping promotes nerve regeneration. © 2011 Lavasani et al

    Probiotic Bifidobacterium breve Induces IL-10-Producing Tr1 Cells in the Colon

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    Specific intestinal microbiota has been shown to induce Foxp3+ regulatory T cell development. However, it remains unclear how development of another regulatory T cell subset, Tr1 cells, is regulated in the intestine. Here, we analyzed the role of two probiotic strains of intestinal bacteria, Lactobacillus casei and Bifidobacterium breve in T cell development in the intestine. B. breve, but not L. casei, induced development of IL-10-producing Tr1 cells that express cMaf, IL-21, and Ahr in the large intestine. Intestinal CD103+ dendritic cells (DCs) mediated B. breve-induced development of IL-10-producing T cells. CD103+ DCs from Il10−/−, Tlr2−/−, and Myd88−/− mice showed defective B. breve-induced Tr1 cell development. B. breve-treated CD103+ DCs failed to induce IL-10 production from co-cultured Il27ra−/− T cells. B. breve treatment of Tlr2−/− mice did not increase IL-10-producing T cells in the colonic lamina propria. Thus, B. breve activates intestinal CD103+ DCs to produce IL-10 and IL-27 via the TLR2/MyD88 pathway thereby inducing IL-10-producing Tr1 cells in the large intestine. Oral B. breve administration ameliorated colitis in immunocompromised mice given naïve CD4+ T cells from wild-type mice, but not Il10−/− mice. These findings demonstrate that B. breve prevents intestinal inflammation through the induction of intestinal IL-10-producing Tr1 cells

    Immune Response to Bifidobacterium bifidum Strains Support Treg/Th17 Plasticity

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    In this work we analyzed the immune activation properties of different Bifidobacterium strains in order to establish their ability as inductors of specific effector (Th) or regulatory (Treg) responses. First, we determined the cytokine pattern induced by 21 Bifidobacterium strains in peripheral blood mononuclear cells (PBMCs). Results showed that four Bifidobacterium bifidum strains showed the highest production of IL-17 as well as a poor secretion of IFNγ and TNFα, suggesting a Th17 profile whereas other Bifidobacterium strains exhibited a Th1-suggestive profile. Given the key role of Th17 subsets in mucosal defence, strains suggestive of Th17 responses and the putative Th1 Bifidobacterium breve BM12/11 were selected to stimulate dendritic cells (DC) to further determine their capability to induce the differentiation of naïve CD4+ lymphocytes toward different Th or Treg cells. All selected strains were able to induce phenotypic DC maturation, but showed differences in cytokine stimulation, DC treated with the putative Th17 strains displaying high IL-1β/IL-12 and low IL-12/IL-10 index, whereas BM12/11-DC exhibited the highest IL-12/IL-10 ratio. Differentiation of naïve lymphocytes confirmed Th1 polarization by BM12/11. Unexpectedly, any B. bifidum strain showed significant capability for Th17 generation, and they were able to generate functional Treg, thus suggesting differences between in vivo and vitro responses. In fact, activation of memory lymphocytes present in PBMCS with these bacteria, point out the presence in vivo of specific Th17 cells, supporting the plasticity of Treg/Th17 populations and the key role of commensal bacteria in mucosal tolerance and T cell reprogramming when needed
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