601 research outputs found

    Tracking of Hepatopancreatic parvo-like virus (HPV) disease in Litopenaeus vannamei of the hatcheries in the Bushehr Province

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    Presence of hepatopancreatic parvo-like vines (HPV) disease was assessed from June until October 2009 in Litopenaeus vannamei hatcheries and grow-out farms of the Bushehr province. Samples were collected from 6 hatcheries and 6 grow-out farms located in coasted areas. From each hatchery, 100 PL samples with average age PL5-PL8 and 20-30 samples from each grow-out farm with average age 105 to 120 days were collected. The samples were divided into three groups one used for gross sign and wet mount with Gimsa, the second group was preserved in Davidson Fixative and used for histopathology and the third group was fixed in ethyl alcohol 95% and used for polymerase chain Reaction (PCR). In gross sign 30%- 40% of the shrimp showed different sizes and some were smaller than the others. In the wet mount group with Gimsa staining of hepatopancrease, the inclusion body with basophilic color was seen. The histopathology indicated that the hepatopancreatic cell was infected and the basophilic inclusion body observed in many samples. The PCR examined with IQ 2000 Kit was negative. The rate of infection (ROI) was 1.1% for hatcheries and 32% for grow-out farms

    The Solid Phase Extraction of Some Metal Ions Using Palladium Nanoparticles Attached to Silica Gel Chemically Bonded by Silica-Bonded N-Propylmorpholine as New Sorbent prior to Their Determination by Flame Atomic Absorption Spectroscopy

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    In this research at first palladium nanoparticle attached to a new chemically bonded silica gel has been synthesized and has been characterized with different techniques such as X-ray diffraction (XRD), fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Then, this new sorbent (chemically modified silica gel with N-propylmorpholine (PNP-SBNPM)) was efficiently used for preconcentration of some metal ions in various food samples. The influence of effective variables including mass of sorbent, flow rate, pH of sample solutions and condition of eluent such as volume, type and concentration on the recoveries of understudy metal ions were investigated. Following the optimization of variables, the interfering effects of some foreign ions on the preconcentration and determination of the investigated metal ions described. At optimum values of variables, all investigated metal ions were efficiently recovered with efficiency more than 95%, relative standard deviation (RSD) between 2.4 and 2.8, and detection limit in the range of 1.4–2.7 ng mL−1. The present method is simple and rapidly applicable for the determination of the understudied metal ions (ng mL−1) in different natural food samples

    Optimization of expression, purification and handling anti bacteria feature protein of bovine neutrophil B-defensing BNBD2

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    زمینه و هدف: دیفنسین‎ها یکی از بزرگ‎ترین خانواده‎ی پپتید‎های ضد میکروب می‎باشند که به واسطه‎ی فعالیت بر علیه باکتری‎ها، قارچ‎ها و بسیاری از ویروس‎ها به عنوان آنتی‎بیوتیک‎های نسل جدید منفعت بسیاری دارند. هدف از این مطالعه بهینه سازی بیان، تخلیص و بررسی خاصیت ضد میکروبی پروتئین بتا دیفنسین 2 نوتروفیل‎های گاو (BNBD2) بوده است. روش بررسی: در این مطالعه‎ی تجربی-آزمایشگاهی باکتری اشرشیاکلی B‏L21(DE3) حامل وکتور pET-32a(+) که ژن BNBD2 در آن همسانه سازی شده بود جهت مطالعات مورد استفاده قرار گرفت. بیان پروتئین BNBD2 با تغییر در پارامترهای دانسیته‎ی سلولی، دمای رشد، مدت زمان القاء با استفاده از سیستم الکتروفورز عمودی (SDS-PAGE) و تست برادفورد به صورت کمی و کیفی بررسی گردید. مراحل تخلیص پروتئین نوترکیب با کمک روش شیمیایی شکافت در جایگاه فرمیک اسید و عبور از سانتریکون و اثر ضد باکتری پروتئین تخلیص شده بر چند نمونه‎ی باکتریایی گرم مثبت و گرم منفی مورد بررسی قرار گرفت. یافته ها: با استفاده از محیط کشت Luria–Bertani، شروع القاء در جذب نوری 8/0 در طول موج 600 نانومتر، غلظت یک میلی مولار ماده‎ی القاء کننده‎ی IPTG، دمای رشد 30 درجه و مدت زمان 4 ساعت پس از القاء بیشترین میزان بیان پروتئین به دست آمد. پروتئین نوترکیب با استفاده از شکافت در جایگاه فرمیک اسید و عبور از سانتریکون تخلیص گردید. نتایج آزمایش وسترن بلاتینگ نیز نشان داد که پروتئین نوترکیب به طور اختصاصی به آنتی‎بادی mouse anti-(His)6 peroxidase متصل می‎گردد. تشکیل هاله‎ی عدم رشد در محیط‎های کشت مولر هینتون آگار حاوی کشت سطحی باکتری های مورد آزمایش خاصیت ضد باکتری این پروتئین را نشان داد. نتیجه گیری: با توجه به خاصیت ضد میکروبی پروتئین BNBD2و امکان بیان پروتئین در باکتری E. coli می توان به تولید انبوه این پروتئین نوترکیب اقدام نمود

    Natural source-based graphene as sensitising agents for air quality monitoring

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    Natural carbon powder has been used as a precursor to prepare two main types of sensitising agents of nitrogen-doped carbon nanoparticles (N-CNPs) and nitrogen-doped graphene quantum dots coupled to nanosheets (N-GQDs-NSs) by using simple treatments of chemical oxidation and centrifugation separation. Characterization based on FTIR, XPS, XRD, Raman spectroscopy, FE-SEM, HR-TEM, AFM, UV-Vis and FL, revealed successful doping carbon nanoparticle with nitrogen with an average plane dimension of 50 nm and relatively smooth surface. The versatility of the prepared samples as sensitising agents was developed and established by exploiting its ability for detection of volatile organic compounds via simple optical fibre based sensing configuration. The comparative experimental studies on the proposed sensor performance indicate fast response achieved at a few tens of seconds and excellent repeatability in exposure to the methanol vapour. The low limit of detection of 4.3, 4.9 and 10.5 ppm was obtained in exposure to the methanol, ethanol and propanol vapours, respectively, in the atmosphere condition. This study gives insights into the chemical/physical mechanism of an enhanced economic optical fibre based gas sensor and illustrates it for diverse sensing applications, especially for chemical vapour remote detection and future air quality monitoring

    Readings on L2 reading: Publications in other venues 2021-2022

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    This feature offers an archive of articles published in other venues during the past year and serves as a valuable tool to readers of Reading in a Foreign Language (RFL). It treats any topic within the scope of RFL and second language reading. The articles are listed in alphabetical order, each with a complete reference as well as a brief summary. The editors of this feature attempt to include all related articles that appear in other venues. However, undoubtedly, this list is not exhaustive

    Construction of expression vectors carrying mouse peroxisomal protein gene (PeP) with GST and Flag labels

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    The aim of this study was to construct expression vectors carrying mouse peroxisomal protein gene (PEP-cDNA) in prokaryotic and mammalian expression vectors in chimeric cDNA types, encompassingGST and FLAG with PEP-cDNA. PEP-cDNA was sub-cloned in pGEX6p2 prokaryotic expression vector in order to label this gene with GST to purify PEP protein for further biochemical analysis and identifying related proteins thereafter. FLAG-PEP recombinant DNA was produced and sub-cloned inpUcD3 eukaryotic expression vector to express tagged-PEP protein for transient transfection analysis and identifying intracellular localization of PEP protein in future experiments. PEP-cDNA was amplifiedin different PCR reactions using pEGFP-PEP vector and 2 sets of primers introducing specific restriction sites at the ends of PEP. PCR products with BamHI/SalI restriction sites were treated by restriction enzymes and inserted into the pGEX6p2, downstream of GST tag. PEP-cDNA containingBamHI/ApaI restriction sites and FLAG gene (which amplified using pUcD3-FLAG-PEX3 vector) were used as templates in secondary PCR for amplifying FLAG-PEP recombinant DNA. FLAG-PEP fragment was treated by enzymatic digestion and inserted into the pUcD3 eukaryotic expression vector.pGEX6p2-PEP and pUcD3-FLAG-PEP constructed vectors were transformed into the one shot TOP10 and JM105 bacterial competent cells, respectively. Positive colonies were selected for plasmid preparation. Results confirmed correct amplification of the expected products. PEP-cDNA in both PCRreactions encompasses 630 bp. FLAG fragment containing designed sites was 77 bp and FLAG-PEP fragment was 700 bp. Sequencing of constructed vectors confirmed that PEP-cDNA was tagged appropriately and inserted free of mutation and in frame with GST and FLAG

    Genetic Variants of Cytochrome b-245, Alpha Polypeptide Gene and Premature Acute Myocardial Infarction Risk in An Iranian Population

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    Background: Oxidative stress induced by superoxide anion plays critical roles in the pathogenesis of coronary artery disease (CAD) and hence acute myocardial infarction (AMI). The major source of superoxide production in vascular smooth muscle and endothelial cells is the NADPH oxidase complex. An essential component of this complex is p22phox, that is encoded by the cytochrome b-245, alpha polypeptide (CYBA) gene. The aim of this study was to investigate the association of CYBA variants (rs1049255 and rs4673) and premature acute myocardial infarction risk in an Iranian population. Methods: The study population consisted of 158 patients under the age of 50 years, with a diagnosis of premature AMI, and 168 age-matched controls with normal coronary angiograms. Genotyping of the polymorphisms was performed by the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Results: There was no association between the genotypes and allele frequencies of rs4673 polymorphism and premature acute myocardial infarction (P>0.05). A significant statistical association was observed between the genotypes distribution of rs1049255 polymorphism and AMI risk (P=0.037). Furthermore, the distribution of AA+AG/GG genotypes was found to be statistically significant between the two groups (P=0.011). Conclusions: Our findings indicated that rs1049255 but not rs4673 polymorphism is associated with premature AMI
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