6,038 research outputs found

    Validity of naked eye single tube red cell osmotic fragility test (NESTROFT) in screening of beta-thalassemia trait

    Get PDF
    زمینه و هدف: تالاسمی متداولترین اختلال تک ژنی است که رهایی از آن از طریق درمان قطعی ممکن نبوده و مستلزم پیشگیری از طریق به کارگیری یک روش قابل اعتماد و کم هزینه برای غربالگری ناقلین و در مرحله بعد ارایه آموزش، مشاوره ژنتیک، تشخیص قبل از تولد و خاتمه انتخابی به زندگی جنین های مبتلا به این اختلال است. هدف از این مطالعه ارزیابی تست اسموتیک تک لوله ای چشمی گلبول های قرمز (NESTROFT) به عنوان یک تست غربالگری در راستای کشف مبتلایان به بتاتالاسمی مینور بود. روش بررسی: در این مطالعه توصیفی- تحلیلی، تست NESTROFT بر روی 158 نفر متشکل از 51 نفر فرزندان والدینی که حداقل یکی از بچه های آنها دارای بتا تالاسمی ماژور بود، 51 فرد طبیعی و 56 فرد از مبتلایان به فقر آهن انجام شد. داده های حاصل به کمک آزمون های آماری آنالیز واریانس یک راهه و آزمون تعقیبی دانت تجزیه و تحلیل گردید. یافته ها: بر اساس نتایج، حساسیت و ارزش اخباری منفی تست NESTROFT 100 بوده و با توجه به 14 مورد نتیجه مثبت کاذب ناشی از فقر آهن، ویژگی آن 9/86 و ارزش اخباری مثبت تست 5/78 می باشد. نتیجه گیری: تست NESTROFTدر عین کم هزینه بودن و سهولت انجام، حساسیت بالایی برای کشف بتا تالاسمی مینور داشته و می توان از آن در کشورهای در حال توسعه با منابع اقتصادی و تکنیکی محدود از قبیل ایران در مقیاس وسیع جهت غربالگری توده ای استفاده نمود

    Analyzing of in-cylinder flow structures and cyclic variations of partially premixed combustion in a light duty engine

    Get PDF
    Partially Premixed Combustion (PPC) strategy offers the potential for simultaneously reduction of NOx and soot emissions with high efficiency. This low temperature combustion strategy involves a proper mixing of fuel and air prior to auto-ignition. During ignition delay (ID) the exact amount of premixing is crucial for the combustion behaviour and emission formation.In this article, high-speed particle image velocimetry (HS-PIV) has been applied to characterise the in-cylinder flow and cycle-to-cycle variations in a light-duty optical engine during fired conditions. The engine is operated at 800 rpm and at a constant CA 50 (~ 8 CAD aTDC). Multiple injections strategies (single, double and triple injections) have been applied to investigate their influence on the flow inside the piston bowl and squish region. The 2D velocity fields are evaluated and investigated over a range of crank angles in the compression and expansion strokes in order to understand the cycle-to-cycle variations. To investigate the problem of cyclic- variations on in-cylinder flows the phase-invariant proper orthogonal decomposition (POD) technique was used. The POD decomposition technique provides a classification method based on an energy criterion by which the mean flow is seen as a superposition of coherent structures. From their temporal coefficients it is possible to characterize its dynamical behaviour

    Time-resolved in-cylinder PIV measurement in a light duty optical engine under PPC conditions

    Get PDF
    The understanding of in-cylinder flow field is one of the keys to realize Partially Premixed Combustion (PPC) for internal combustion engines, which has potential to achieve high combustion efficiency with low soot and NOx emissions. In this work, time resolved Particle Image Velocimetry (PIV) was performed to measure the flow field inside the cylinder of a single-cylinder light-duty optical diesel engine.The engine was modified to Bowditch configuration, and was installed with a quartz piston and a transparent cylinder liner, to allow optical access. The geometry of the quartz piston crown is based on the regular combustion chamber design of mass produced diesel engine, including a re-entrant bowl shape. This causes severe distortion on the obtained images, which has to be handled by a distortion correction method before PIV process.The in-cylinder flow structures in a vertical plane at the center of cylinder were obtained both within the piston bowl and within the squish volume, during the compression and expansion stroke. Measurements were performed under three different injection strategies as well as motored engine condition. Both the instantaneous flow field from single cycle and ensemble average flow field calculated from 100 cycles at motored engine condition show a well match with previous studies. The results from fired engine conditions show different Interaction between injected fuel and in-cylinder air at different Crank Angle Degrees (CADs) with different injection strategies.All the results in this study can provide a quantitative dataset being useful to model validation of numerical simulation work to investigate PPC engine more

    Detection and distribution of virulence genes in Aeromonas hydrophila isolates causing infection in cultured carps

    Get PDF
    Aeromonas hydrophila is a bacterium associated with many diseases and disorders such as fin rot, skin ulcers and lethal hemorrhagic septicemia in fish. It bears several virulence factors including type III secretion system (T3SS), aerolysin, cytolytic enterotoxin and enzymes (e.g., hemolysins, lipase) that seem to play an important role in its pathogenesis. Detection of virulence markers by polymerase chain reaction (PCR) is a key procedure in defining the pathogenic ability of pathogenic bacteria and preparing a vaccine for its treatment. In this sense, this study was aimed to determine the frequency of virulence genes in isolates obtained from infected cultured carps in Khuzestan province. Out of 200 moribund carps with septicemic symptoms, 125 isolates were belonged to the motile aeromonads and 59 isolates were identified as A. hydrophila by biochemical methods. Finally, using PCR analysis, 31 isolates were identified as A. hydrophila. Five virulence genes were detected in these isolates including hemolysin, aerolysin, cytolytic enterotoxin and T3SS (aopB and ascV) by specific primers. Results showed that 23 (74.19%), 18 (58.06%), 16 (51.61%), 13 (41.63%) and 10 (32.25%) isolates possessed cytolytic enterotoxin, hemolysin, aerolysin, and T3SS genes, respectively. The results of the present study showed that among 31 isolates, only five isolates had all of dominant virulence genes. Thirteen other isolates had genotypes including hlyA+, aerA+, and act+. The remaining isolates had at least one virulence gene. This study showed that determination of the virulence genes by PCR can be a reliable method to identify a potential pathogenic Aeromonad strain

    Study of -629C/A polymorphism of cholesteryl ester transfer protein gene in statin effects on plasma high density lipoprotein cholesterol level

    Get PDF
    Background and aim: Cholesteryl ester transfer protein (CETP) plays pivotal role in HDL metabolism and in reverse cholesterol transport (RCT) pathway. CETP gene variants such as -629C/A that affect HDL cholesterol directly modulates CETP gene tranh1ional activity. This study was aimed to determine influence of -629C/A polymorphism of CETP in statin effects with regard to plasma HDL cholesterol levels. Methods: In this deh1ive-analytical study 196 adult patients with LDL-C more than 120mg/dL were divided into two groups base on lovastatin and atorvastatin using. Lipid profile was measured in all subjects before and after treatment and -629C/A polymorphism of CETP promoter was studied using polymerase chain reaction/restriction fragment length polymorphism method. Data were compared with paired t-test and ANOVA in SPSS software. Results: Cholesterol was decreased and HDL was increased in AA genotype more than other genotypes by lovastatin but ApoA1 was increased in CC genotype. ApoA1 also was increased in CC genotype more than AA or AC genotypes by atorvastatin. Conclusion: In CC genotype lovastatin and specially atorvastatin increased ApoA1 in HDL particles more than other genotypes. Therefore treatment with lovastatin and atorvastatin is more effective in patients with CC genotype for raising HDL particles activity

    Study of -629C/A polymorphism of cholesteryl ester transfer protein gene in statin effects on plasma high density lipoprotein cholesterol level

    Get PDF
    Background and aim: Cholesteryl ester transfer protein (CETP) plays in HDL metabolism and in reverse cholesterol transport (RCT) pivotal role pathway. CETP gene variants such as -629C/A that affect HDL cholesterol directly, modulates CETP gene transcriptional activity. This study was aimed to determine influence of -629C/A polymorphism of CETP in statin effects with regard to plasma HDL cholesterol levels. Methods: In this descriptive-analytical study, 196 adult patients with LDL-C more than 120mg/dL were divided into two groups base on lovastatin and atorvastatin using. Lipid profile was measured in all subjects before and after treatment and -629C/A polymorphism of CETP promoter was studied using polymerase chain reaction/restriction fragment length polymorphism method. Data were compared with paired t-test and ANOVA in SPSS software. Results: Cholesterol was decreased and HDL was increased in AA genotype more than other genotypes by lovastatin, but ApoA1 was increased in CC genotype. ApoA1 also was increased in CC genotype more than AA or AC genotypes by atorvastatin. Conclusion: In CC genotype, lovastatin and specially atorvastatin increased ApoA1 in HDL particles more than other genotypes. Therefore, treatment with lovastatin and atorvastatin is more effective in patients with CC genotype for raising HDL particles activity

    Constraints on Randall-Sundrum model from top-antitop production at the LHC

    Full text link
    We study the top pair production cross section at the LHC in the context of Randall-Sundrum model including the Kaluza-Klein (KK) excited gravitons. It is shown that the recent measurement of the cross section of this process at the LHC restricts the parameter space in Randall-Sundrum (RS) model considerably. We show that the coupling parameter (kMˉpl\frac{k}{\bar{M}_{pl}}) is excluded by this measurement from 0.03 to 0.22 depending on the mass of first KK excited graviton (m1m_1). We also study the effect of KK excitations on the spin correlation of the top pairs. It is shown that the spin asymmetry in ttˉt\bar{t} events is sensitive to the RS model parameters with a reasonable choice of model parameters.Comment: 17 pages, 6 figure
    corecore