Numerical Study of Diodicity Mechanism in Different Tesla-Type Microvalves

AbstractMicrovalve is one of the most important components in microfluidic systems and micropumps. In this paper, three-dimensional incompressible flow through a Tesla-type microvalve is simulated using FLUENT computational fluid dynamic package. The flow is laminar and SIMPLE algorithm is used. The second-order upwind method is implemented for discretizing convective terms. The diodicity mechanism is investigated in detail for three different microvalves. Effect of several series Tesla-type microvalves on diodicity is also studied. The numerical analyses reveal that the mechanism of diodicity occurs at the T-junction and side channel. If inlet and outlet channels are eliminated, diodicity can be increased by 2. Pressure field analysis shows that the pressure drop is much severe at the junction of the reverse flow compared to the forward flow. The obtained numerical results are compared with those of experimental and a good agreement between them is noticed

Uncertainty Quantification of the CO2 Storage Process in the Bunter Closure 36 Model

The UK plans to bring all greenhouse gas emissions to net-zero by 2050. Carbon capture and storage (CCS), an important strategy to reduce global CO2 emissions, is one of the critical objectives of this UK net-zero plan. Among the possible storage site options, saline aquifers are one of the most promising candidates for long-term CO2 sequestrations. Despite its promising potential, few studies have been conducted on the CO2 storage process in the Bunter Closure 36 model located off the eastern shore of the UK. Located amid a number of oil fields, Bunter is one of the primary candidates for CO2 storage in the UK, with plans to store more than 280 Mt of CO2 from injections starting in 2027. As saline aquifers are usually sparsely drilled with minimal dynamic data, any model is subject to a level of uncertainty. This is the first study on the impact of the model and fluid uncertainties on the CO2 storage process in Bunter. This study attempted to fully accommodate the uncertainty space on Bunter by performing twenty thousand forward simulations using a vertical equilibrium-based simulator. The joint impact of five uncertain parameters using data-driven models was analysed. The results of this work will improve our understanding of the carbon storage process in the Bunter model before the injection phase is initiated. Due to the complexity of the model, it is not recommended to make a general statement about the influence of a single variable on CO2 plume migration in the Bunter model. The reservoir temperature was shown to have the most impact on the plume dynamics (overall importance of 41%), followed by pressure (21%), permeability (17%), elevation (13%), and porosity (8%), respectively. The results also showed that a lower temperature and higher pressure in the Bunter reservoir condition would result in a higher density and, consequently, a higher structural capacity

The Effect of Garlic Extract on Expression of INFγ And Inos Genes in Macrophages Infected with Leishmania major

Background: The study was aimed to show the effect of molecular mechanism of Aqueous Garlic Extract (AGE) on expression of IFNγ and iNOS genes in Leishmania major.Methods: Leishmania major promastigotes (MRHO/IR/75/ER) were added to the in-vitro cultured J774 cell line, the cells were incubated for 72 hours. Various concentrations of garlic extract (9.25, 18.5, 37, 74, 148 mg/ml) were added to the infected cells. MTT assay was applied for cellular proliferation. After 72 hours of incubation, supernatants were collected and total RNA was extracted from the infected cells. The express of IFNγ and iNOS genes were studied by RT-PCR method.Results: The colorimetric MTT assay after 3 days of incubation showed cytotoxic effect of garlic extract with an IC50 of 37 mg/ml. In addition, IFNγ and iNOS genes expression by RT-PCR indicated that garlic extract lead to over expression of these genes in J774 cell line infected with L. major.Conclusion: Garlic extract exerts cytotoxic effect on infected J774 cell line. In addition, the hypothesis that garlic can improve cellular immunity with raising the expression of IFNγ and of iNOS genes con­firmed

Multi-locus sequence type analysis of Shigellas pp. Isolates from Tehran, Iran

Background and Objectives: Strains of Shigella spp. can cause shigellosis, or bacillary dysentery. That is a public health problem worldwide. The aim of this study was to describe the population structure and genetic relatedness of multidrug resistant S. sonnei and S. flexneri isolated during a one year period from children with diarrhea in Tehran, Iran. Materials and Methods: A total of 70 Shigella spp. were detected during the study period. Twenty MDR isolates of Shigella spp. were randomly selected and used in this study. Bacterial identification was performed by conventional biochemical and serological and confirmed by molecular method. After antimicrobial susceptibility testing, we used Multilocus sequence typing (MLST) for subtyping isolates. Results: We found 14 Shigella sonnei and 6 Shigella flexneri isolates. Results of MLST showed five sequence types (ST) (145, 152, 241, 245, 1502) and BURST analysis revealed the largest number of single locus variant (SLV) and highest frequency (FREQ) for ST152. ST 152 with nine members was predicted as the founder by BURST. Frequency for ST 1502 and ST 245 was four isolates and the least frequency was seen for ST 241 and 145 with one and two members, respectively. ST 145 and ST 245 were described as singletons in BURST. All isolates with ST145 and ST245 were identified as Shigella flexneri. Conclusion: Annual Multi locus sequence typing of MDR Shigella would help us in better understanding of dominant species and comparing our results with the same studies in other countries especially our neighbor countries in source tracking purposes. © Tehran University of Medical Science. All rights reserved

Prevalence of chronic kidney disease and its associated risk factors: The first report from Iran using both microalbuminuria and urine sediment

Background: The incidence of major risk factors of chronic kidney disease (CKD) in the world is on the rise, and it is expected that this incidence and prevalence, particularly in developing countries, will continue to increase. Using data on urinary sediment and microalbuminuria, we aimed to estimate the prevalence of CKD in northeast Iran. Methods: In a cross-sectional study, the prevalence of CKD in a sample of 1557 regionally representative people, aged � 18 years, was analyzed. CKD was determined based on glomerular filtration rate (GFR) and microalbuminuria. Life style data, urine and blood samples were collected. Urine samples without any proteinuria in the initial dipstick test were checked for qualitative microalbuminuria. If the latter was positive, quantitative microalbuminuria was evaluated. Results: 1557 subjects with a mean age of 56.76 ± 12.04 years were enrolled in this study. Based on the modifcation of diet in renal disease (MDRD) equation, 137 subjects (8.89%) were categorized as CKD stages III-V. Based on urine abnormalities, the prevalence of combined CKD stages I and II was 10.63%, and based on macro- and microalbuminuria it was 14.53%. The prevalence of CKD was significantly associated with sex, age, marital status, education, diabetes mellitus (DM), hypertension (HTN), ischemic heart disease (IHD), waist to hip ratio, myocardial infarction (MI), and cerebrovascular accident (CVA). Conclusion: CKD and its main risk factors are common and represent a definite health threat in this region of Iran. Using and standardizing less expensive screening tests in low resource countries could be a good alternative that may improve the outcome through early detection of CKD

Effects of total light deprivation on dorsal lateral geniculate nucleus of male neonate rats

Objectives: This study examines the effects of total light deprivation on the developing lateral geniculate nucleus, the primary integration centre for visual information Methods: Sprague-Dawley rats were reared for one month in a dark room from 7th postnatal day before eye opening. A group of rats was taken back into normal condition for 15 days, and then perfused. Coronal sections of LGN were prepared and stained with Cresyl Violet and Cytochrome Oxidase to investigate the number of neurons, volume and length, as well as neuronal activity level. Results: The results showed that LD for one month causes progressive loss of neurons and decreases neuronal activity level in the LGN. Conclusion: It can be concluded that during early postnatal development of the rats� visual system, light deprivation causes structural and functional changes in LGN. © 2010, Oman Medical Specialty Board. All rights reserved

The beneficial effect of (-)-epigallocatechin-3-gallate in an experimental model of Alzheimer's disease in rat: A behavioral analysis

Background: Progressive cognitive decline is one of the hallmark symptoms of Alzheimer's disease (AD) which can be modeled by β-amyloid injection into specific regions of brain. Since epigallocatechin-3-gallate (EGCG) is a potent antioxidant agent which its role against oxidative stress and inflammation has been shown in prior studies, we tried to determine whether EGCG administration protects against β-amyloid-induced memory and coordination impairment in rats. Methods: Animals (male Wistar rats) were divided into four groups: sham operated, EGCG-pretreated sham operated (sham + EGCG), untreated lesion (lesion), and EGCG-pretreated lesion (lesion + EGCG). Animals in lesion, lesion + EGCG, and sham + EGCG groups received sterile saline or saline plus EGCG (10 mg/kg) intraperitoneally one day pre-surgery and every other day for three weeks. The lesion was induced one day after EGCG pretreatment by injection of 4 μl of sterile saline or water containing 2 nmol/μl β-amyloid (1-40) into the hippocampal fissure. For behavioral analysis, psychomotor coordination (PMC) index and spontaneous alternation behavior were assessed using Rota-rod Treadmill and Y-maze, respectively at the third week post-lesion. Results: We found that β-amyloid (1-40) injection into hippocampus can decrease these behavioral indexes in lesion group in comparison with sham group which is similar to behavioral changes in AD. On the other hand, pretreatment with EGCG can improve the PMC index and spatial Y-maze alternation in the lesion + EGCG group in comparison with lesion group. Conclusion: We concluded that EGCG can be effective in restoring β-amyloid-induced behavioral derangements in rats regarding coordination and memory abilities