492 research outputs found

    An experimental study of permeability determination in the lab

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    Understanding the flow characteristics in laminar and turbulent flow regime is important for different aspects of reservoir and production engineering. One of the most important parameters in fluid flow is the permeability of the porous media. It is common practice in the industry to use Darcy and Forchheimers equations for characterising the fluid flow in the porous media at laminar and turbulent regimes, respectively. Core flooding experiments were performed with 1.5-inch diameter size core samples from limestone and sandstone formations. The permeability of the samples was measured in the laminar regime at basis flow rate. Then, the flow rate was increased in different steps and permeability was measured, accordingly. The plot of permeability versus flow rate was used to track the evolution of the flow regimes in the core porous media. There are different challenges to monitor the transition between laminar and turbulent regime through core flooding experiments. These challenges are discussed in this paper through both literature review and also experimental results. The results indicated that the core sample preparation, experiment control parameters and also test profiles are important aspects when measuring permeability in the lab. © 2012 WIT Press

    Persuasive Discourse Impairments in Traumatic Brain Injury

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    Background: Considering the cognitive and linguistic complexity of discourse production, it is expected that individuals with traumatic brain injury (TBI) should face difficulties in this task. Therefore, clinical examination of discourse has become a useful tool for studying and assessment of communication skills of people suffering from TBI. Among different genres of discourse, persuasive discourse is considered as a more cognitively demanding task. However, little is known about persuasive discourse in individuals suffering from TBI. Objectives: The purpose of this study was to evaluate the performance of adults with TBI on a task of spoken persuasive discourse to determine the impaired linguistic measures. Patients and Methods: Thirteen TBI nonaphasic Persian speaking individuals, ranged between 19 to 40 years (Mean = 25.64 years; SD = 6.10) and 59 healthy adults matched by age, were asked to perform the persuasive discourse task. The task included asking the participants to express their opinion on a topic, and after the analysis of the produced discourse, the two groups were compared on the basis of their language productivity, sentential complexity, maze ratio and cohesion ratio. Results: The TBI group produced discourses with less productivity, sentential complexity, cohesion ratio and more maze ratio compared the control group. Conclusions: As it is important to consider acquired communication disorders particularly discourse impairment of brain injured patients along with their other clinical impairments and regarding the fact that persuasive discourse is crucial in academic and social situations, the persuasive discourse task presented in this study could be a useful tool for speech therapists, intending to evaluate communication disorders in patients with TBI

    The Effects of Temperature and Seasons on Subcutaneous White Adipose Tissue in Humans: Evidence for Thermogenic Gene Induction

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    Context: Although brown adipose tissue (BAT) activity is increased by a cold environment, little is known of the response of human white adipose tissue (WAT) to the cold. Design: We examined both abdominal and thigh subcutaneous (SC) WAT from 71 subjects who were biopsied in the summer or winter, and adipose expression was assessed after an acute cold stimulus applied to the thigh of physically active young subjects. Results: In winter, UCP1 and PGC1 α mRNA were increased 4 to 10-fold (p\u3c0.05) and 1.5 to 2-fold, respectively, along with beige adipose markers, and UCP1 protein was 3-fold higher in the winter. The seasonal increase in abdominal SC WAT UCP1 mRNA was considerably diminished in subjects with a BMI \u3e 30 kg/m2, suggesting that dysfunctional WAT in obesity inhibits adipose thermogenesis. After applying an acute cold stimulus to the thigh of subjects for 30 min, PGC1α and UCP1 mRNA was stimulated 2.7-fold (p \u3c 0.05) and 1.9-fold (p = 0.07), respectively. Acute cold also induced a 2 to 3-fold increase in PGC1α and UCP1 mRNA in human adipocytes in vitro, which was inhibited by macrophage-conditioned medium and by the addition of TNFα. Conclusion: Human SC WAT increases thermogenic genes seasonally and acutely in response to a cold stimulus and this response is inhibited by obesity and inflammation. (J Clin Endocrinol Metab 99: E2772–E2779, 2014

    Adipose Tissue Extracellular Matrix and Vascular Abnormalities in Obesity and Insulin Resistance

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    Context: Insulin resistance is associated with inflammation, fibrosis, and hypoxia in adipose tissue. Objective: This study was intended to better characterize the extracellular matrix (ECM) and vascularity of insulin-resistant adipose tissue. Design: Adipose expression of collagens, elastin, and angiogenic factors was assessed using realtime RT-PCR and immunohistochemistry (IHC) in abdominal sc adipose tissue. Adipocyte-macrophage coculture experiments examined the effects of polarized macrophages on adipose ECM gene expression, and the effects of collagens were measured in an angiogenesis assay. Participants and Setting: A total of 74 nondiabetic subjects participated at a University Clinical Research Center. Interventions: Interventions included baseline adipose biopsy and measurement of insulin sensitivity. Main Outcome Measures: Outcome measures included characterization of vascularity and ECM in adipose tissue. Results: CD31 (an endothelial marker) mRNA showed no significant correlation with body mass index or insulin sensitivity. In a subgroup of 17 subjects (nine obese, eight lean), CD31-positive capillary number in obese was decreased by 58%, whereas larger vessels were increased by 70%, accounting for the lack of change in CD31 expression with obesity. Using IHC, obese (compared with lean) subjects had decreased elastin and increased collagen V expression, and adipocytes cocultured with M2 macrophages had reduced elastin and increased collagen V expression. In obese subjects, collagen V was colocalized with large blood vessels, and the addition of collagen V to an angiogenesis assay inhibited endothelial budding. Conclusions: The adipose tissue from obese/insulin- resistant subjects has fewer capillaries and morelarge vessels as compared with lean subjects.The ECM of adipose tissue may play an important role in regulating the expandability as well as angiogenesis of adipose tissue. (J Clin Endocrinol Metab 96: E1990–E1998, 2011

    Blood Levels of Methemoglobin in Patients with Aluminum Phosphide Poisoning and its Correlation with Patient's Outcome

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    Although methemoglobinemia following aluminum phosphide (AlP) intoxication has been reported, probable effect of blood level of methemoglobin (Met-Hb) on outcome of AlP-poisoned patients has not yet been investigated. This study aimed to evaluate blood levels of methemoglobin in patients with AP intoxication and its correlation with patient's outcome. This prospective study was carried out at the Loghman-Hakim poison hospital from April 2009 to August 2009. All patients aged >12 years who had ingested AlP and were admitted at the hospital were enrolled in the study. Using the co-oximetry, blood Met-Hb level was measured at the time of admission and 24 h later if the patient survived. Forty-eight patients with AlP intoxication including 24 males were evaluated. Mean age of the patients was 25.5 ± 9.5 years. There was significant association between blood level of Met-Hb at the time of admission and mortality (2.4 ± 7.1 in survivors versus 15.2 ± 13.5 in non-survivors, P< 0.001). The same association was found at the 2nd day of admission (2.9 ± 8.2 in survivors versus 26.5 ± 19.9 in non-survivors, P = 0.02). The present study found an association between blood level of Met-Hb and mortality in patients with AlP intoxication. Effect of administration of vitamin C and methylene blue on outcome of patients with AlP intoxication should be investigated in future studies. © 2010 American College of Medical Toxicology

    Field hospital in disasters: A systematic review

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    Background: Field hospitals (FH) can be mobile or fixed. The main goal of FHs is providing health care and preventing injuries caused by disasters or providing emergency medical operations. However, preparing a safe and fast-erupting structure and facility is very important. Objectives: In this systematic review study, field hospitals are reviewed. Methods: In the present study, a systematic review was performed following the PRISMA guideline. To identify the articles, MEDLINE, web of science, Google scholar, PubMed, Persian journals and databases were searched to find related papers. Results: After full text screening as the final screening step, 20 papers were entered in the study. Findings showed that structures used for establishing a FH are usually tents, using vehicles (trucks and buses), pre-fabricated steel, and concrete structures. The FHs were used for war and earthquake disasters. Conex, tent, steel, and concrete structure are the most used structures for FH in wars, while tents are the most common structure used for natural disasters. Conclusions: The present study reviewed available reports on FH to collect useful data that should be focused on establishment of an FH suitable for a disaster. Furthermore, this study provides a list of the most important indexes that must be considered in proposing a type of FH. Tent structure was the most common structure for the establishment of FHs. Copyright © 2018

    Therapeutic targeting in pediatric acute myeloid leukemia with aberrant HOX/MEIS1 expression

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    Despite advances in the clinical management of childhood acute myeloid leukemia (AML) during the last decades, outcome remains fatal in approximately one third of patients. Primary chemoresistance, relapse and acute and long-term toxicities to conventional myelosuppressive therapies still constitute significant challenges and emphasize the unmet need for effective targeted therapies. Years of scientific efforts have translated into extensive insights on the heterogeneous spectrum of genetics and oncogenic signaling pathways of AML and identified a subset of patients characterized by upregulation of HOXA and HOXB homeobox genes and myeloid ecotropic virus insertion site 1 (MEIS1). Aberrant HOXA/MEIS1 expression is associated with genotypes such as rearrangements in Histone-lysine N-methyltransferase 2A (KMT2A-r), nucleoporin 98 (NUP98-r) and mutated nucleophosmin (NPM1c) that are found in approximately one third of children with AML. AML with upregulated HOXA/MEIS1 shares a number of molecular vulnerabilities amenable to recently developed molecules targeting the assembly of protein complexes or transcriptional regulators. The interaction between the nuclear scaffold protein menin and KMT2A has gained particular interest and constitutes a molecular dependency for maintenance of the HOXA/MEIS1 transcription program. Menin inhibitors disrupt the menin-KMT2A complex in preclinical models of KMT2A-r, NUP98-r and NPM1c acute leukemias and its occupancy at target genes leading to leukemic cell differentiation and apoptosis. Early-phase clinical trials are either ongoing or in development and preliminary data suggests tolerable toxicities and encouraging efficacy of menin inhibitors in adults with relapsed or refractory KMT2A-r and NPM1c AML. The Pediatric Acute Leukemia/European Pediatric Acute Leukemia (PedAL/EUPAL) project is focused to advance and coordinate informative clinical trials with new agents and constitute an ideal framework for testing of menin inhibitors in pediatric study populations. Menin inhibitors in combination with standard chemotherapy or other targeting agents may enhance anti-leukemic effects and constitute rational treatment strategies for select genotypes of childhood AML, and provide enhanced safety to avoid differentiation syndrome. In this review, we discuss the pathophysiological mechanisms in KMT2A-r, NUP98-r and NPM1c AML, emerging molecules targeting the HOXA/MEIS1 transcription program with menin inhibitors as the most prominent examples and future therapeutic implications of these agents in childhood AML.</p

    Pioglitazone Induces Apoptosis of Macrophages in Human Adipose Tissue

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    Metabolic syndrome and type 2 diabetes mellitus are associated with an increased number of macrophage cells that infiltrate white adipose tissue (WAT). Previously, we demonstrated that the treatment of subjects with impaired glucose tolerance (IGT) with the peroxisome proliferator-activated receptor γ (PPARγ) agonist pioglitazone resulted in a decrease in macrophage number in adipose tissue. Here, adipose tissue samples from IGT subjects treated with pioglitazone were examined for apoptosis with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining. TUNEL-positive cells were identified, and there was a significant 42% increase in TUNEL-positive cells following pioglitazone treatment. Overlay experiments with anti-CD68 antibody demonstrated that most of theTUNEL-positive cellsweremacrophages.To determine whether macrophage apoptosis was a direct or indirect effect of pioglitazone treatment, human THP1 cells were treated with pioglitazone in vitro, demonstrating increased TUNEL staining in a dose- and time-dependent manner. Furthermore, the appearance of the active proteolytic subunits of caspase-3 and caspase-9 were detected in cell lysate from THP1 cells and also increased in a dose- and time-dependent manner following pioglitazone treatment. Pretreatment with a PPARγ inhibitor, GW9662, prevented pioglitazone induction of the apoptotic pathway in THP1 cells. Differentiated human adipocytes did not show any significant increase in apoptosis after treatment in vitro with piolgitazone. These findings indicate that PPARγ has distinct functions in different cell types in WAT, such that pioglitazone reduces macrophage infiltration by inducing apoptotic cell death specifically in macrophages through PPARγ activation

    Comparison of Harrington rod and Cotrel-Dubousset devices in surgical correction of adolescent idiopathic scoliosis

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    Background: Since the time of Paul Harrington numerous implants have been introduced for correction of scoliosis, but none are ideal. Newer devices are very expensive, and in our country some patients cannot afford them. Objectives: The aim of this study was to compare the results of the Harrington rod (HR) device and the newer Cotrel-Dubousset (CD) device in treatment of adolescent idiopathic scoliosis (AIS). Materials and Methods: A retrospective review assessed patients with AIS admitted for spinal curve correction treated with HR (n = 120) and CD devices (n = 138) between October 1988 to April 2001 at the Shafa Yahyaeian Hospital, Tehran, Iran. We extracted information from the patient's file and radiographs before, after and two years post-operation. Results: The mean age of patients was 16.7 ± 2.5 years. There was no statistically significant difference between the two groups regarding gender, age, curve before surgery, and percentage of flexibility. The mean curvature was 70 ± 20.7 in the HR and 64.81 ± 19.4 in the CD group before surgery (P = 0.09); and the mean curvature was 40 ± 16.3 and 26.58 ± 15.37 in HR and CD groups respectively after surgery (P = 0.156). The mean curvature was 47.2 ± 15.9 in HR and 31.2 ± 15.4 in CD groups at two years follow-up (P = 0.156). Conclusions: Results of many studies have shown no significant impairment in long-term quality of life and function in patients treated with Harrington rods. According to previously performed studies and the current study, surgical correction with Harrington rods seem to be comparable with the newer more expensive CD device. Although there is no doubt that the preference is to use newer devices in view of some disadvantages of HR, but this does not preclude using it for patients that cannot afford the newer devices. Copyright © 2013, Trauma Research Center; Published by Kowsar Corp
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