245 research outputs found

    Direct measurement of bending stiffness and estimation of Young's modulus of vertically aligned carbon nanofibers

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    The bending stiffness of individual, as-grown, vertically aligned carbon nanofibers was measured using a custom-built atomic force microscope placed inside a scanning electron microscope. The internal structure of the nanofiber was best modeled as dual-phase, composed of an inner graphitic core covered with a tapered amorphous carbon shell. It was found that the fibers have a relatively low bending stiffness, with Young's modulus values of about 10 GPa for the inner core and 65 GPa for the outer shell. The low Young's modulus of the inner core is attributed to a non-zero angle between the graphitic sheets and the nanofiber axis. The weak shear modulus between graphitic sheets thereby dominates the mechanical behaviour of the fibers

    Epidemiological and Clinical Characteristics of Scorpion Stings in Ahwaz, Southwest Iran (2006-2010)

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    Background: Scorpion sting is a health problem in the world including tropical regions of Iran as in rural region of Khuzestan province. Therefore appropriate diagnosis and treatment has a special aspect. The aim of present study was to evaluation of demographic status and clinical aspect of scorpion sting patient due to better prevention and treatment and diagnosis.Methods: This survey done by analyzing medical records of patients suffered from scorpion sting, hospitalize in Razi hospital in Khuzestan province (southwest of Iran) among 2006-2010. Patient information have been extracted and inserted in the inquiry form and data were analyzed by SPSS software.Results: In the present study 1922 patients have been studied. Proportion of females stung by scorpion to male was 1.29 to 1. Place of sting were mostly trunk (693 cases =36.05%) and remains were on other part of body. About 419 persons (21.8 %) have come to hospital about 6-24 hours after being stung and 708 people (36.83 %) came there in less than 6 hours. Most sting (41.2 %) were at night time and other were at daylight. 1308 persons were stung by an unknown black and yellow scorpion and 614 cases (31.94%) by scorpion known as Hemiscorpius lepturus. 708 persons of patients (39.83%) have been suffered from hemoglobinoria , 709 persons (39.88%) were suffered from coagulation dysfunction. Totally 508 persons of patients (26.43%) received blood products. 36 of patients were died, of which 24 cases (1.24%) were female and 12 patients (0.62%) were male. most of patients (1842 cases  95.83%) were hospitalized 1-2 days.Conclusion: In this survey, Patients at the emergency units showed signs of local and systemic effects, 36 patients were died. We propose that public awareness and physician readiness combined with the availability of effective antivenom has potential value in reducing complications and lethality in scorpion envenomation

    Hepatitis A virus and Hepatitis E virus seroprevalence among blood donors in Tehran, Iran

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    Background: Hepatitis A virus (HAV) and Hepatitis E virus (HEV) are both transmitted by the fecal-oral route and are known as the leading causes of acute viral hepatitis in the world, especially in developing countries. There is a lack of updated data on HAV and HEV seroprevalence in Iran. Objectives: The aim of this study was to determine the seroprevalence of HAV and HEV among a group of blood donors in Tehran, Iran. Materials and Methods: A cross-sectional study was performed from July 2014 to December 2014, on a total of 559 blood donors referred to the Tehran blood transfusion center. The serum samples were tested for antibodies to HAV and HEV, using the enzyme-linked immunosorbent assay. Results: In the present study, 536 (95.9) cases were male and 23 (4.1) female with mean age of 38 years. Out of 559 blood donors, 107 (19.1) were first-time donors, 163 (29.2) lapsed donors and 289 (51.7) regular donors. Anti-HAV was found in 395 (70.7) and anti-HEV in 45 (8.1) of the blood donors. The HAV and HEV seroprevalence increased by age. There was no significant difference between genders in terms of anti-HAV and anti-HEV status. The HAV and HEV seroprevalence was significantly related to the level of education, where the donors with higher level of education had lower rate of HAV and HEV seroprevalence. The HAV and HEV seroprevalence was significantly higher in regular and lapsed donors than in first-time donors. Conclusions: The present study showed that both HAV and HEV infections are still endemic in Iran. © 2016, Kowsar Corp

    Health Literacy and Medication Practices in Senior Housing Residents

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    Objective: To conduct a descriptive analysis of health literacy, knowledge of prescribed medications, and methods of administering medications in a cohort of senior housing residents.https://scholarworks.uvm.edu/comphp_gallery/1027/thumbnail.jp

    Drug-related mutational patterns in hepatitis B virus (HBV) reverse transcriptase proteins from Iranian treatment-Naïve chronic HBV patients

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    Background: Immunomodulators and Nucleotide analogues have been used globally for the dealing of chronic hepatitis B virus (HBV) infection. However, the development of drug resistance is a major limitation to their long-term effectiveness. Objectives: The aim of this study was to characterize the hepatitis B virus reverse transcriptase (RT) protein variations among Iranian chronic HBV carriers who did not receive any antiviral treatments. Materials and Methods: Hepatitis B virus partial RT genes from 325 chronic in active carrier patients were amplified and directly sequenced. Nucleotide/amino acid substitutions were identified compared to the sequences obtained from the database. Results: All strains belonging to genotype D.365 amino-acid substitutions were found. Mutations related to lamivudine, adefovir, telbivudine, and entecavir occurred in (YMDD) 4% (n = 13), (SVQ) 17.23% (n = 56), (M204I/V + L180M) 2.45% (n = 8) and (M204I) 2.76% (n = 9) of patients, respectively. Conclusions: RT mutants do occur naturally and could be found in HBV carriers who have never received antiviral therapy. However, mutations related to drug resistance in Iranian treatment-naïve chronic HBV patients were found to be higher than other studies published formerly. Chronic HBV patients should be monitored closely prior the commencement of therapy to achieve the best regimen option. © 2013, KOWSAR Corp

    Is Evaluation of Hepatitis A Immunity Required or Not?

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    Hepatitis A virus (HAV) infection is one of the most common causes of acute hepatitis and it is a serious health problem worldwide. HAV infection is a vaccine preventable disease that can produce the lifelong immunity seen in many developed countries with the vaccination schedule administered to children; however this vaccine is not used in developing countries at the present time. Improvements in food and water hygiene have caused a displacement of hepatitis A infection from children to adults which has increased mortality rates. Therefore evaluation of HAV immunity levels can help health authorities develop polices for prophylaxis especially in developing countries

    Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

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    Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death
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