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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: SCIENTIA IRANICA
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: The present paper investigates, numerically, the effect of the Grashof number to a Reynolds number ratio (Gr/Re), on fluid flow and heat transfer within a vertical channel for two cases: Mixed (natural-forced) convection and combined mixed convection-radiation. The flow in the channel is assumed to be two-dimensional, laminar and steady. The wall temperature is defined as a linear function of the channel height. When dealing with the combined mixed convection-radiation case, radiational properties have been taken into account, both for the walls and the fluid. The fluid has a Prandtl number of 0.71 and it is radiationally assumed as a participating medium. A comparison between the two cases at a constant Gr/Re is reported, so as to investigate the influence of radiation, as one of the heat transfer modes, more clearly. To solve the governing equations (i.e., mass continuity, momentum and energy) the Finite Volume method is employed and the SIMPLE algorithm is adopted to couple the velocity and pressure fields. The radiative transfer equation is solved using the Discrete Ordinates Method, by adopting its S_4 order quadrature scheme. The results for both cases are presented as the profiles of axial velocity across the channel width, axial centerline velocity, bulk temperature and pressure versus channel height.
- انتشار مقاله: 26-01-1385
- نویسندگان: F. Bazdidi-Tehrani,F. Bazdidi-Tehrani,F. Bazdidi-Tehrani
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Sciences, Islamic Republic of Iran
- نوع مقاله: Journal Article
- کلمات کلیدی: Apoptosis,caspase-3,Caspase-9,Cladribine,MDA-MB468
- چکیده:
- چکیده انگلیسی: The purpose of the present study is to investigate the cytotoxicity/apoptotic effect of 2-chloro-2′-deoxyadenosine, cladribine, (2-CdA) in the human breast cancer cell line, MDA-MB468 (estrogen receptor negative, ER−). MTT [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide] assay, annexin V-Fluorescein/PI and Hoechst 33258 staining were used to detect cytotoxicity and cell apoptosis. The activation of caspase-3 and -9 was assayed using caspase activation assay kits. Gel electrophoresis was performed to detect DNA fragmentation. Treatment of MDA-MB468 cells with different concentrations of 2-CdA (50, 100 and 500 µM) resulted in a significant increase in the cell death. Annexin V-Fluorescein/PI and Hoechst 33258 staining revealed that the cell death was mainly of apoptotic type. DNA laddering profile was also obtained in the treated MDA-MB468 cells using DNA fragmentation analysis. A significant (p<0.05) increase in the activity of caspase-3 and -9 was observed. Pre-treatment of the cells with kinase inhibitor, 5′-amino-5′-deoxyadenosine inhibited the cytotoxicity effect of 2-CdA. This suggests that intracellular phosphorylation activation reaction plays a key role in the 2-CdA-induced apoptosis. In conclusion, this study showed that high dose of cladribine has an apoptotic effect on ER−MDA-MB468 breast cancer cells and its intracellular phosphorylation is necessary for cytotoxicity.
- انتشار مقاله: 06-06-1382
- نویسندگان: F. Karami-Tehrani,F. Karami-Tehrani,F. Karami-Tehrani
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Engineering, Transactions A: Basics
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: A dynamic mathematical model is presented which successfully simulates the respiratory control system of the newborn infant in different physiological conditions. The primary objective in constructing this model has been to provide a simulation aid in the investigation of maturation of the respiratory system, and the respiratory disorders during the newborn period, without the need for invasive measurements. The model comprises a continuous plant and a discrete controller. The controller incorporates as key elements, a non-linear multiple regression element and an energy minimization routine for the determination of ventilation and breathing frequency. The plant consists of lungs, body tissue, brain tissue, a cerebrospinal fluid compartment and central and peripheral receptors. The effect of shunt in the lungs is included in the model and the lung volume and the dead space are time varying. The effects of Hering-Breuer type reflexes are embodied to accomplish respiratory synchronization. The model is examined and simulation results of its performance for test conditions in hypoxia and hypercapnia are presented.
- انتشار مقاله: 11-10-1348
- نویسندگان: F. T. Tehrani,F. T. Tehrani,F. T. Tehrani
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Iran,Seroprevalence,broiler farms,Avian Influenza H9N2,Abattoirs
- چکیده:
- چکیده انگلیسی: The present study aimed to determine the seroprevalence of H9N2 influenza in broiler farms at the time of slaughter in Iran. A total of 747 birds were sampled from 74 Farms in 13 provinces within 2013-2016. The obtained sera were investigated using the hemagglutination inhibition (HI) test. Out of 74 sampled farms and 747 birds, 57 farms (77%) and 445 (59.57%) birds were reported to be seropositive. In 2013, 10 farms and 110 birds were sampled out of which three farms (29.6%) and 29 birds (30%) were seropositive. In 2014, 24 farms and 220 birds were sampled out of which 22 farms (91.6%) and 220 birds (86.6%) were positive in six provinces. In 2015, 30 farms and 278 birds were sampled out of which 5 farms (16%) and134 birds (48.2%) were positive in four provinces. Finally, in 2016, 7 farms (70%) out of 10 sampled farms and 62 birds (59%) out of 105 sampled birds were positive for H9N2 in eight provinces. The mean titer of units in 2013 was statistically lower, as compared to that in 2014 (P<0.01). In addition, the proportion of positive serum units in 2013 was statistically lower, as compared to that in 2014 (P<0.001). In general, the prevalence of H9N2 was high indicating the continuous circulation of the virus in Iran. Given the importance and impact of this virus on the poultry industry, people’s livelihood, and public health, more epidemiological studies are needed to evaluate the effectiveness of the adopted measures and methods in controlling the H9N2 virus.
- انتشار مقاله: 14-08-1397
- نویسندگان: M. H. Fallah Mehrabadi,N. Motamed,A. Ghalyanchilangeroudi,F. Tehrani,A. Borhani Kia
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Newcastle disease,Backyard poultry,Effectiveness,Haemagglutination inhibition (HI),ND.TR.IR vaccine
- چکیده:
- چکیده انگلیسی: Newcastle disease causes many economic losses to the poultry industry in most countries. This disease is endemic in Iran. Backyard poultry is considered the reservoir of Newcastle virus; however, there is either no vaccination program against Newcastle, or it is performed in a restricted manner. Commercial live vaccines are inactive and sensitive to temperature; moreover, vaccine delivery to villages and remote areas requires special equipment and high cost to maintain the cold chain. This study evaluated the effectiveness of a thermostable Newcastle vaccine produced by the Razi Institute (ND.TR.IR) on the backyard poultry. In four provinces, at least 4 villages were selected as the treatment group, and the same number was selected as the control group. At least, 30 birds were sampled in each village. In each group, blood samples were collected before vaccination and 2 weeks later, and the serum titer of the samples was examined with the haemagglutination inhibition test. The arithmetic mean and standard deviation of the sample titers at the rural level were compared using paired t-test before and after vaccination in each group. Moreover, Repeated Measures ANOVA was utilized to compare the vaccinated and control groups in terms of the titer changes before and after vaccination. In this study, 584 and 389 samples were taken from the treatment (53 households in 20 villages) and control groups (33 households in 14 villages). The mean serum titer values of Newcastle were 4.51±3.03 and 6.64±2.48 in the treatment group before and after vaccination, respectively (P<0.001). The increase in mean titer of the treatment group (2.31 log) was statistically higher than that in the control group (0.66 log) (P<0.001). Out of 584 birds, 517 (88.5%) ones had titer above 3 in the second turn in the treatment group. The thermostable vaccine (ND.TR.IR) produced by the Razi institute is suitable for backyard poultry, which immunizes them against Newcastle disease. Appropriate vaccination programs for backyard poultry should be made; moreover, vaccination of backyard poultry can be effective in preventing the circulation of the field viruses.
- انتشار مقاله: 01-12-1396
- نویسندگان: M.H. Fallah Mehrabadi,S.A. Ghafouri,A. Shoushtari,F. Tehrani,S. Masoudi,M. Abdoshah,S. Amir Hajloo,M. Shabani
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Iran,Avian Influenza,bird garden,live bird market,zoo
- چکیده:
- چکیده انگلیسی: Avian Influenza (AI) H9N2 is endemic in Iran; therefore, it is necessary to estimate the disease prevalence among birds in live bird markets (LBMs) and assess the risk spread across the country. Accordingly, this study aimed to estimate the prevalence of AI subtypes in LBMs, bird gardens, and zoos during October and November 2015 in Iran and investigate the associated risk factors. Data related to independent variables for birds and premises were collected using a prepared questionnaire which included items about previously known potential risk factors associated with avian influenza infection. Serological testing was carried out to detect the antibodies against H5, H7, and H9. Regarding H5 and H7, the antigens H5N2 and H7N1 were used in this study. Positive samples on the first test were examined with the second antigens, namely H5N1 and H7N7. Moreover, sera with titers ≥4 (i.e. log2) were considered positive and premises with at least one positive bird were considered as positive units. In total, 87 premises were included in this cross-sectional study. Serum samples were examined utilizing hemagglutination inhibition, and RT-PCR was conducted on swab samples. Regarding the molecular test, the RNA was extracted using the High Pure Viral RNA Kit (Roche, Germany). In addition, real-time RT-PCR was conducted based on the described method. The seroprevalence rates of H9N2 were 83.9% and 31.8% at the premises and bird levels, respectively. Totally, 9.2% of pooled swab samples were positive for H9N2. However, all sera and swab samples were negative for H5 and H7. Hot and humid weather (OR=0.13, 95% CI 0.02 – 0.78) as well as bird-keeping condition (i.e., enclosed area) (OR=0.11, 95% CI 0.012 – 1.02) were protective factors for H9N2. High seroprevalence rate of H9 indicates that the disease is endemic in Iranian LBMs. Active surveillance must be carried out in LBMs, especially in the northern provinces of Iran. In addition, cleanliness and improved hygiene would be useful to prevent the spread of disease in LBMs.
- انتشار مقاله: 12-11-1397
- نویسندگان: M. H. Fallah Mehrabadi,A. Ghalyanchi Langeroudi,A. Bahonar,M. H. Rabiee,F. Tehrani,S. Amirhajloo,K. Steneroden,M.D. Salman
- مشاهده
- جایگاه : پژوهشی
- مجله: Archives of Razi Institute
- نوع مقاله: Journal Article
- کلمات کلیدی: Iran,Avian Influenza,H9N2,Seroprevalence,Ostrich
- چکیده:
- چکیده انگلیسی: The aim of this study was to determine the seroprevalence of avian influenza H9N2 subtype in the industrial ostrich farms and its geographical distribution. This cross-sectional study was conducted from January to June 2015. A total of 40 farms were selected from different provinces of Iran, from each of which 11 ostriches (n=440) were sampled. The sera samples were examined using 4 hemagglutination units of H9N2 antigens. A frequency distribution was used to describe the responses to the survey questions. The mean titers between provinces were compared using one-way analysis of variance. According to the results, 21 (47.5%) out of 40 farms and 108 (24.5%) out of 440 ostriches tested positive in the HI-H9N2 test. There were statistically significant differences between the mean titers of samples in different provinces (P<0.001). The current study was conducted on unvaccinated ostriches. The results showed that H9N2 had a high seroprevalence at both farm and bird levels. The findings of this study can be for the further investigation of infection in ostrich farms in order to consider this species in the surveillance programs of the Iranian Veterinary Organization. The detection and isolation of viruses and epidemiological investigation are necessary for the persistent use of H9N2 vaccines in some ostrich farms.
- انتشار مقاله: 07-08-1395
- نویسندگان: M. H. Fallah Mehrabadi,A. Bahonar,K. Mirzaei,A. Ghalyanchi Langeroudi,S. A. Ghafouri,F. Tehrani,A. Hashemi
- مشاهده