431 research outputs found

    Analytical investigation of laminar flow through expanding or contracting gaps with porous walls

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    AbstractLaminar, isothermal, incompressible and viscous flow in a rectangular domain bounded by two moving porous walls, which enable the fluid to enter or exit during successive expansions or contractions is investigated analytically using optimal homotopy asymptotic method (OHAM). OHAM is a powerful method for solving nonlinear problems without depending to the small parameter. The concept of this method is briefly introduced, and it׳s application for this problem is studied. Then, the results are compared with numerical results and the validity of these methods is shown. After this verification, we analyze the effects of some physical applicable parameters to show the efficiency of OHAM for this type of problems. Graphical results are presented to investigate the influence of the non-dimensional wall dilation rate (α) and permeation Reynolds number (Re) on the velocity, normal pressure distribution and wall shear stress. The present problem for slowly expanding or contracting walls with weak permeability is a simple model for the transport of biological fluids through contracting or expanding vessels

    Prevalence of goiter among schoolchildren from Gorgan, Iran, a decade after national iodine supplementation: Association with age, gender, and thyroperoxidase antibodies

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    Background: One decade after universal salt iodization in Iran, goiter prevalence, urinary iodine concentration (UIC) and thyroperoxidase antibody (TPOAb) values were assessed among schoolchildren in Gorgan, Iran. Methods: From 2003-2004, 500 girls and 900 boys aged 7-11 yr were evaluated for goiter by palpation. UIC was measured in 183 randomly-selected goitrous children. Serum TSH, T 4, and TPOAb were measured in 53 goitrous and 30 non-goitrous children with adequate UIC. Results: Goiter was detected in 370 (26.4%) children. Goiter was present in 31 % of girls and 17% of boys age 9 (p<0.012); 37% of girls and 20% of boys age 10 (p<0.003); and 52% of girls and 19% of boys age 11 (p<0.0001). Median (range) UIC for all goitrous children sampled was 190 (20-600) μg/l; 220 (30-590) in boys and 170 (20-600) in girls (p=0.001). Eight point seven percent of goitrous children and 22% of goitrous girls aged 10-11 had UIC<100 μg/l, while 47% of the goitrous children had UIC≥200 μg/l. TPOAb was present in 52.8% of goitrous children and 10% of non-goitrous children (p=0.0001 ). TPOAb was present in 53.9% of 10-11 and 22.7% of 7-9 yr old goitrous and non-goitrous children (p=0.003) with adequate UIC. Median (range) TSH was 2.9 (0.3-10.9) mlU/l in TPO-positive and 1.8 (0.5-4.1) in TPO-negative children (p=0.001 ). Conclusions: Gorgan, Iran, is an iodine-sufficient area and almost half of schoolchildren have more than adequate UIC. TPOAb is associated with endemic goiter. Despite sufficient UIC overall, some school-aged girls remain at risk of iodine deficiency. ©2005, Editrice Kurtis

    NEW THERAPEUTIC PERSPECTIVES IN IRRITABLE BOWEL SYNDROME: TARGETING LOW-GRADE INFLAMMATION, IMMUNO-NEUROENDOCRINE AXIS, MOTILITY, SDECRETION AND BEYOND

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    Irritable bowel syndrome (IBS) is a chronic, recurring, and remitting functional disorder of the gastrointestinal tract characterized by abdominal pain, distention, and changes in bowel habits. Although there are several drugs for IBS, effective and approved treatments for one or more of the symptoms for various IBS subtypes are needed. Improved understanding of pathophysiological mechanisms such as the role of impaired bile acid metabolism, neurohormonal regulation, immune, dysfunction, the epithelial barrier and the secretory properties of the gut has led to advancements in the treatment of IBS. With regards to therapies for restoring intestinal permeability, multiple studies with prebiotics and probiotics are ongoing, even if to date their efficacy has been limited. In parallel, much progress has been made in targeting low-grade inflammation, especially through the introduction of drugs such as mesalazine and rifaximin, even if a better knowledge of the mechanisms underlying the low-grade inflammation in IBS may allow the design of clinical trials that test the efficacy and safety of such drugs. This literature review aims to summarize the findings related to new and investigational therapeutic agents for IBS, most recently developed in preclinical as well as Phase 1 and Phase 2 clinical studies

    Spatial analysis of colorectal cancer in Iran

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    Colorectal cancer is one of the most common cancers. Due to demographic changes, it is predicted that the incidence of this cancer will increase. Variations of its incidence rate among geographical areas are due to various contributing factors. Since there have been a lack of studies on this topic in our country, the present assessment of spatial patterns of colorectal cancer incidence in Iran was performed. In this ecological study, the new cases of colon cancer were extracted from Cancer Registry Center report of the Health Deputy of Iran in 2009. The reported incidences of the disease were standardized on the basis of the World Health Organization population and the direct method. Then the data were inserted into the GIS software, and finally, using the analysis of hot spots (Getis-Ord Gi) high-risk areas were drawn. Provinces that are higher or lower than the national average (1.9 SD) were considered hot spots or cold spots, significant at the level of 0.05. A total of 6,210 cases of colorectal cancer were registered in Iran in 2009, of which 3,727 were in men and 2,783 in women (age-standardized rates of 11.3 and 10.9 per 100,000 population, respectively). The results showed that in central and northern Iran including Isfahan, Qom, Tehran, Qazvin and Mazandaran significant hot spots in men were present (p < 0.05). In women also we have high incidence in northern and central states: Mazandaran province (p < 0.01) and the province of Tehran (p < 0.05) had higher incidences than the national average and were apparent as significant hot spots. Analysis of the spatial distribution of colorectal cancer showed significant differences between different areas pointing to the necessity for further epidemiological studies into the etiology and early detection. © 2016, Asian Pacific Journal of Cancer Prevention

    Herbal therapy for hemorrhoids: An Overview of Medicinal Plants Affecting Hemorrhoids

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    Hemorrhoids are one of the most common rectal diseases that affect millions of people in the world and cause many medical and socio-economic problems. The resulting pain is very severe and incurs exorbitant costs for the patient and the government. This study aimed to review the medicinal plants that affect hemorrhoids. Complete databases searched for in those articles were Google Scholar, SID, Scopus, PubMed, Science Direct, and WOS search engines. The search was done for articles published that included the search term containing, medicinal plants and hemorrhoids in their title. This study focused on published articles and papers from 1991 to 2022.The results showed medicinal plants Aloe vera, Trigonella foenum-graecum L, Nigella sativa L, Curcuma longa L, Cocos nucifera L, Solanum nigrum L., Alhagi persarum Boiss & Buhse, Plantago lanceolata L, Achillea santolina, Malva neglecta Wallr,  Rubus fruticosus L  have effects like anti-bleeding, analgesic, anti-inflammatory,  and wound-healing, and with hemorrhoid-healing effect. Generally, the investigated traditional Iranian edible plants are rich in different types of chemical compounds and have special benefits in the prevention and treatment of diseases.Keywords: Medicinal plants; Hemorrhoids; Diseases; Remedy Drugs 

    Molecular assay on Crimean Congo Hemorrhagic Fever virus in ticks (Ixodidae) collected from Kermanshah Province, Western Iran

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    Background: Crimean-Congo Hemorrhagic Fever (CCHF) is a feverous and hemorrhagic disease endemic in some parts of Iran and caused by an arbovirus related to Bunyaviridae family and Nairovirusgenus. The main virus reservoir in the nature is ticks, however small vertebrates and a wide range of domestic and wild animals are regarded as reservoir hosts. This study was conducted to determine the infection rate of CCHF virus in hard ticks of Sarpole- Zahab County, Kermanshah province, west of Iran. Methods: From total number of 851 collected ticks from 8 villages, 131 ticks were selected randomlyand investigated for detection of CCHF virus using RT-PCR. Results: The virus was found in 3.8 of the tested ticks. Hyalommaanatolicum, H.asiaticum and Rhipicephalus sanguineus species were found to have viral infection, with the highest infection rate (11.11) in Rh. sanguineus. Conclusion: These findings provide epidemiological evidence for planning control strategies of the disease in the study area
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