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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Finance
- نوع مقاله: Journal Article
- کلمات کلیدی: inflation,Earnings Management,political connections,Economic Indicators
- چکیده:
- چکیده انگلیسی: Governments always affect the economic environment as legislators in the field of business. The economic conditions governing the market and business require different conditions and contexts for decision making and corporate execution practices. Companies and managers administering them under environmental conditions, achieve their goals by employing various earnings management methods. Hence, the present study examines the effect of governments’ economic performance on the earnings management methods used in listed companies of Tehran Stock Exchange (2004-2016) for a sample of 16 industries and 271 companies. To test the hypotheses, multivariate regression model was used. The results showed that during the research period, companies managed earnings, and while more than 70% of companies used the accrual earnings management method, there was a relationship between annual economic indicators and real earnings management, and the change in general level of prices and the political connections of states have affected the relationship. Also, the accruals-based earnings management method occurred independent of annual economic indicators and there is a significant relationship between governments changes and earnings management methods.
- انتشار مقاله: 11-10-1348
- نویسندگان: Alireza Ghonji Feshki,Mohammad Hamed Khanmohammadi,Shohreh Yazdani
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Leishmania infantum,Monoclonal antibodies,Axenic amastigotes,Hybridoma cells,Leishmaniases
- چکیده:
- چکیده انگلیسی: Objective(s): Leishmaniasis is endemic in 88 countries. Amastigote forms of Leishmania are experts at exploiting host cell processes to establish infection. Monoclonal antibodies are key reagents used in the diagnosis of infectious and non-infectious diseases. The aim of this study was to produce monoclonal antibodies against axenic amastigotes of the Leishmania infantum strain in Iran.
Materials and Methods: First, standard strains were cultured and axenic amastigote antigens of L. infantum were obtained. Since then, BALB/c mice were immunized and antibody titers were determined. For hybridoma cell formation, lymphocytes isolated from spleen of immunized mice and myeloma cells were fused at a ratio of 10 to 1 in the presence of polyethylene glycol, followed by limiting dilution for the isolation of monoclones. Subsequently, antibody isotypes were determined by using the isotyping kit. The best clone was injected intraperitoneally to pristane-primed mice for large scale production of monoclonal antibodies. The specificity of antibody was determined with Western blotting.
Results: Approximately 25 positive monoclones were obtained, of which four hybrids producing anti-amastigotes L. infantum monoclonal antibodies with high optical density (OD), selected and designated as 8D2 FVI6, 8D2 FVI3, 6G2 FV4 and 6G2 FV3. Results from isotype determination showed the IgG2b sub-class in 6G2FV2 and 8D2FVI6 monoclones.
Conclusion: This study produced monoclonal antibody against amastigotes of Iranian strain of L. infantum for the first time. These antibodies have reactivity against Iranian strain of L. infantum and can be used in the diagnosis of Kala-azar.- انتشار مقاله: 09-05-1396
- نویسندگان: Ezzat Nourizadeh,Seyed Jalal Zargar,Mohammad Hossein Alimohammadian,Soheila Ajdary,Mehdi Mahdavi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: oxidative stress,Dyslipidemia,LOX-1 receptor,Swimming exercise
- چکیده:
- چکیده انگلیسی: Objective(s):Lectin-like low density lipoprotein receptor (LOX-1) has pivot role in vascular complications, which is upregulated in numerous pathological conditions. Since exercise has beneficial effects in prevention of hyperlipidemic complications, present study examined protective effects of aerobic exercise through reduction of LOX-1 expression in heart during dyslipidemia. Materials and Methods: Four groups of rats were used (N=25): Normal, Normal and exercise, High fat and High fat and exercise. High fat diet (HFD) was made by adding 10% animal oil, 2% cholesterol and 0.5% colic acid to standard rodent chow. Exercise protocol consisted of swimming 1 hr/day, and 5 days/week for 8 weeks. Plasma lipids were evaluated at the end of experiment, 48 hr after final session of exercise. At the end, rats were sacrificed and heart was removed for determination of malondialdehyde (MDA) content, and LOX-1 expression. Results:HFD meaningfully changed lipid profile (>50%), but chronic exercise had no significant effects on lipid profile. LOX-1 expression was significantly increased in heart of rats fed with HFD, while swimming exercise considerably reduced gene expression of LOX-1. MDA content was significantly enhanced in rats fed with HFD (4.37±0.6 nmol/mg, P<0.01) compared to normal group (1.56±0.48 nmol/mg), whereas swimming exercise decreased MDA level of heart in rats fed with HFD (2.28±0.32, P<0.01). Conclusion:Findings indicated that swimming exercise is able to diminish heart expression of LOX-1 receptor concomitant reduction of oxidative stress. Since these parameters are involved in generation of dyslipidemic complications, swimming exercise is a good candidate to reduce these complications.
- انتشار مقاله: 03-06-1394
- نویسندگان: Simin Riahi,Mohammad Taghi Mohammadi,Vahid Sobhani,Mansureh Soleimany
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Dog,Duration,Sural nerve,Wallerian degeneration,Schwann cell
- چکیده:
- چکیده انگلیسی: Objective(s): Predegeneration is a standard technique to obtain mitotically activated and enriched cultures of Schwann cells (SCs). This study, for the first time, evaluated the impact of various duration of predegeneration on cell yield and enrichment of SCs from dog peripheral nerve.
Materials and Methods: Dog sural nerves were subjected to 5, 10, 15 day-long in vitro predegeneration. The total cell yield and the purity of SCs were evaluated in each group on the first and seventh day after plating.
Results: The maximum and minimum numbers of cells were counted in 15 day-long predegene-ration and control groups which underwent no predegeneration. The 10 day-long in vitro predegeneration group with 80±0.5% SCs enrichment had the best purity after plating day and could maintain its purity with elapsing on cultures.
Conclusion: 10 day-long predegeneration results in the higher cell number and the better and prolonged purity of SCs in culture.- انتشار مقاله: 27-12-1393
- نویسندگان: Nazila Niapour,Behnam Mohammadi-Ghalehbin,Mohammad Ghasem Golmohammadi,Mohammad Amani,Hossein Salehi,Ali Niapour
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Crocin,Neuroprotection,histopathological changes,Ischemia-reperfusion injury
- چکیده:
- چکیده انگلیسی: Objective(s): Some histopathological alterations take place in the ischemic regions following brain ischemia. Recent studies have demonstrated some neuroprotective roles of crocin in different models of experimental cerebral ischemia. Here, we investigated the probable neuroprotective effects of crocin on the brain infarction and histopathological changes after transient model of focal cerebral ischemia.
Materials and Methods: Experiment was performed in four groups of rats (each group; n=8), sham, control ischemia and ischemia treated rats. Transient focal cerebral ischemia was induced by 80 min middle cerebral artery occlusion (MCAO) followed by 24 hr reperfusion. Crocin, at doses 50 and 80 mg/kg, was injected at the beginning of ischemia (IP injection). Neurologic outcome (Neurological Deficit Score, NDS scale), infarct volume (TTC staining) and histological studies were assessed 24 hr after termination of MCAO.
Results: Treatment with crocin, at doses 50 and 80 mg/kg, significantly reduced the cortical infarct volume by 48% and 60%, and also decreased striatal infarct volume by 45% and75%, respectively. Crocin at two different doses significantly improved the NDS of ischemic rats. At histological evaluation, crocin, at dose 80 mg/kg more than 50 mg/kg, decreased the number of eosinophilic (prenecrotic) neurons and reduced the fiber demyelination and axonal damage in ischemic regions.
Conclusion:Our findings indicated that crocin effectively reduces brain ischemia-induced injury and improves neurological outcomes. Crocin also is a potent neuroprotective factor that can be able to prevent histopathological alterations following brain ischemia.- انتشار مقاله: 20-09-1393
- نویسندگان: Javad Raouf Sarshoori,Mohammad Hossien Asadi,Mohammad Taghi Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Biotechnology
- نوع مقاله: Journal Article
- کلمات کلیدی: Gum Tragacanth,Tyramine, Horseradish Peroxidase,In situ Forming Hydrogel,Enzyme Catalyzed Gelation,Biomedical applications
- چکیده:
- چکیده انگلیسی: Background: The excellent biocompatibility, biodegradability and biological properties of the hydrogels, fabricated using natural polymers, especially polysaccharides, are very advantageous for biomedical applications. Gum tragacanth (GT) is a heterogeneous highly branched anionic polysaccharide, which has been used extensively in food and pharmaceutical industries. Despite, its desirable properties, the potential biomedical applications of this natural gum have not been fully explored. In this study, an enzyme catalyzed in situ forming hydrogel, based on Iranian gum tragacanth (exudate of Astragalus fluccosus) was prepared and characterized for biomedical applications. Objectives: The main objective of the present study was to explore the feasibility of using tragacanth natural gum as a base for in situ-forming hydrogels in biomedical applications. Materials and Methods: First, tyramine (TA) was conjugated to the water-soluble part of GT (TGA) using aqueous-phase carbodiimide activation chemistry. Next, in situ forming hydrogel was prepared via an enzyme catalyzed coupling reaction in the presence of horseradish peroxidase (HRP) and H2O2. Gelation time, swelling/degradation behavior and mechanical properties of the hydrogel and cell viability of the encapsulated cells within these hydrogels were investigated. Results: The gelation time of the hydrogel was less than 30 seconds, which is very desirable for clinical applications. At concentrations ≤ 0.1% (w/v), both GT and TA-TGA showed no toxicity towards human mesenchymal stem cells (hMSCs) and Caco-2 cells. More than 90% of the encapsulated hMSCs in the hydrogels, which were prepared at H2O2 concentrations of less than 15.0 mM, remained viable after 2 hours of incubation. Conclusions: The TA-TGA conjugate can be gelled enzymatically in the presence of HRP and H2O2. This in situ forming hydrogel might be a desirable candidate for biomedical applications.
- انتشار مقاله: 08-08-1392
- نویسندگان: Moslem Tavakol,Ebrahim Vasheghani-Farahani,Masoud Soleimani,Mohammad Amin Mohammadifar,Sameereh Hashemi-Najafabadi,Maryam Hafii
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: HPLC,Plasma,Naproxen,Vortex-assisted dispersive liquid−liquid microextraction
- چکیده:
- چکیده انگلیسی: Extraction and determination of naproxen from human plasma were performed using Vortex-Assisted Inverted Dispersive Liquid-Liquid MicroExtraction (VA−IDLLME) and High-Performance Liquid Chromatography (HPLC). The parameters affecting extraction recovery such as type and volume of extraction and disperser solvents, pH of sample solution, stirring rate, extraction time and salt addition were optimized. Optimal extraction conditions were: 100 µL dodecane as the extraction solvent, 350 µL methanol as disperser solvent, pH of sample = 5, stirring rate: 500 rpm, with no effect of extraction time and no addition of NaCl to the sample solution. Under the optimal conditions a linear range of 1.0–1000.0 ng/mL(R2 = 0.9993) was obtained. Limit of detection, the extraction recovery, and preconcentration factor were 0.32 ng/mL, 87% and 108 respectively.
- انتشار مقاله: 08-11-1394
- نویسندگان: Mohammad Reza Hajmohammadi,Masoumeh Hemmati
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Xanthan gum,partition coefficient,Aroma release,Complex matrix
- چکیده:
- چکیده انگلیسی: The effect of oleic acid (5 and 10% v/v) and xanthan gum (0.5 and 1% wt) on partitioning and retention of ethyl acetate and diacetyl from two matrices with a different composition was investigated by applying static head space gas chromatography. Two matrices with different composition have been developed: one containing carbohydrates (xanthan gum) and in the second one, called complex matrix, lipid (oleic acid) was added. The roles of Xanthan Gum (XG) and lipid (oleic acid) on the retention of aroma compounds were pointed out. Changes in the composition of matrices exhibited a considerable effect on the air/liquid partition coefficient (Ka/l ) values at equilibrium. The kinetic study of the release from both matrices had shown a decrease of the initial rate of release (Ri) by reference with water. The rheological properties of all matrices were investigated and the flow behavior of all matrices was successfully modeled with power law and cross models. Power law model was found as the better model to describe the flow behavior of dispersions.
- انتشار مقاله: 18-02-1390
- نویسندگان: Vahid Samavati,Zahra Emam-Djomeh,Ali Mehdinia,Mohammad Amin Mohammadifar
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: modeling,Scaling,Flow curves,Tragacanth Gum (TG)
- چکیده:
- چکیده انگلیسی: Various scaling methods such as relative viscosity, Peclet and Reynolds scaling were used to find the best scaling law. Scaling and modeling of the flow curves of various model emulsions consist of Tragacanth Gum (TG) (0.5, 1 % wt), Oleic acid (5, 10% v/v) and WPI (2, 4 % wt) were investigated and the best models were selected. As these emulsions are non-Newtonian, they do not obey the usual, simple scaling laws. When the apparent viscosity is reduced to relative viscosity of the medium at zero shear rate, a distinct reduced flow curve is obtained, regardless of TG, oleic acid and WPI concentrations. This will lead to a technique of simplifying complex non-Newtonian flow curves and therefore predicting the rheological flow curves and fluid mechanics when different modifiers are added to food emulsions. The flow behavior of all samples was successfully modeled with Cross, power law and Ellis models and power law model was found as the better model to describe the flow behavior of dispersions. Results showed that both G' and G'' increased with TG, oleic acid and WPI concentrations with pronounce effect of TG content.
- انتشار مقاله: 06-10-1389
- نویسندگان: Vahid Samavati,Zahra Emam-Djomeh,Mohammad Amin Mohammadifar,Mahmoud Omid,Ali Mehdinia
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Pterocarya fraxinifolia,Juglone,Naphthoquinone,RP-HPLC method
- چکیده:
- چکیده انگلیسی: A method for determination of juglone in leaves and hulls of Pterocarya fraxinifolia was developed, based on RP-HPLC. This compound was extracted from leaves and hulls by chloroform refluxing about 2 hours. The chloroform was evaporated under low pressure at 50 ºC to produce a dry residue. The remained materials were dissolved in acetonitrile to be used for determination of this compound. Appropriate conditions for RP-HPLC were determined using standard of juglone. These conditions include, acetonitrile percentage in mobile phase, pH of mobile phase (phosphate buffer) and temperature of column, which were 50%, 4 and 30ºC, respectively. Juglone concentration was determined using standard addition method. The concentrations of juglone were 2.15, 2.74,1.77,1.12and 0.34 g in 100 g of dry leaves in May, June, July, August and September 2001, respectively. The content of juglone in hulls was 0.44 g in 100 g of dry hulls in May.
- انتشار مقاله: 30-09-1383
- نویسندگان: Mohammad Reza Hadjmohammadi,Kamyar Kamel
- مشاهده