303 research outputs found
Performance Evaluation of Sensor Medium Access Control Protocol Using Coloured Petri Nets
AbstractFormal modeling techniques can be used for analysis of wireless sensor networks (WSNs). Coloured Petri nets (CPNs) that is an extension of Petri nets is a powerful modeling technique. In this paper, we present a CPN model for modeling and performance evaluation of a medium access control protocol in WSNs named sensor-medium access control protocol (S-MAC). S-MAC is an energy-aware MAC protocol with nodes scheduling. The proposed model for this protocol uses the hierarchical modeling capability of CPNs. By using CPNs in this case study and the proposed method for modeling packet broadcast, we have demonstrated the possibility of modeling and evaluation of any other MAC protocol in WSNs or mobile ad-hoc networks (MANET)
The efficacy of recombinant versus urinary HCG in ART outcome
Background: Human chorionic gonadotropin (HCG) has been used as a replacement for the mid-cycle luteinizing hormone (LH) surge for several years. The recent arrival of recombinant DNA technology has made recombinant HCG (rHCG) accessible. Objective: To assess efficacy of rHCG compared to urinary HCG (uHCG) for triggering of ovulation and induction of final oocyte maturation in assisted reproductive cycles. Materials and Methods: 200 patients who were candidate for ICSI were randomly divided in two groups. In group I (rHCG), patients received 250μg of rHCG for final oocyte maturation, and in group II (uHCG) the patients received 10000 IU of uHCG. Measured outcomes were number of retrieved oocyte and mature oocyte, maturation rate of oocyte, fertilization rate and clinical pregnancy rate. Results: The rates of oocyte maturity were similar in both groups. Fertilization rate was similar in two groups (58.58% in rHCG group versus 60.58% in uHCG group p=0.666). The clinical pregnancy rate per cycle was similar in both group 34.0% in rHCG group versus 39% in uHCG group (p=0.310). Conclusion: We demonstrated that rHCG is as effective as uHCG, when it is used for final oocyte maturation in ICSI cycles. The numbers of retrieved oocyte and maturation rates were similar in both groups; also fertilization and clinical pregnancy rates were similar
Sun protection factor, total phenol, flavonoid contents and antioxidant activity of medicinal plants from Iran
Purpose: To evaluate the correlation between sun protection factor (SPF) and the content of phenol and flavonoid and antioxidant activity.
Methods: Different parts of 9 medicinal plants were extracted with methanol using three extraction methods (percolation, Soxhlet and ultrasonically assisted extraction) to obtain 42 crude extracts. Their phenol and flavonoid contents, and antioxidant activities were determined using Folin-Ciocalteu reagent, aluminum chloride method and DPPH radical-scavenging activity, respectively. The SPF values were determined and correlated with the phenol and flavonoid contents as well as antioxidant activities.
Results: The phenol and flavonoid contents, and antioxidant activities ranged from 54.16-688.97mg GAE/g, 13.38-146.60 mg QE/g and 9.5-1472.4 µg/mL, respectively while the SPFs were between 0.067 and 0.841. The highest SPF was related to Cucumis melo L. ultrasonically assisted leaf extract (0.841) and Artemisia absinthium L., aerial parts extracted with percolation method (0.717). A significant correlation was found between SPF and phenolic (p= 0.003) and flavonoid contents (p= 0.023).
Conclusion: This study showed a correlation between SPF and phenolic and flavonoid contents. Ultrasonically assisted extract of C. melo leaf has suitable SPF and can be used in sun screen formulations
The Role of Trace Elements in Pseudoexfoliation Syndrome: A Cross-sectional Study
Purpose: Pseudoexfoliation syndrome (PXF) is an age-related condition, characterized by deposition of whitish flake-shaped materials in the anterior segment of the eye. Although it occurs all over the world, a considerable racial variation exists. According to the high frequency of PXF in Iran and the importance of prevention and early treatment, we evaluated the plasma level of iron, zinc, copper, and magnesium in patients with PXF.
Methods: In this study, 83 individuals were enrolled; 40 patients with cataract and PXF as the case group and 43 age- and sex-matched individuals with cataract but without PXF as the control group. The serum levels of the mentioned microelements were compared in two groups.
Results: In the case group, 25 (62.5%) male and 15 (37.5%) female subjects participated. In the control group, the corresponding figures were 22 (51.2%) and 21 (48.8%), respectively. The mean age of the case group was 66.07 ± 9.46 and that for the control group was 66.88 ± 8.04 years. Regarding the case group, the serum levels of iron, zinc, copper, and magnesium were 60.58 ± 21.04, 84.7 ± 14.37, 120.23 ± 14.43, and 2.11 ± 0.23, respectively. These serum levels in the control group were 89.07 ± 26.06, 97.51 ± 17.42, 123.33 ± 19.01, and 2.14 ± 0.16. The serum levels of iron and zinc were significantly lower in the case group than the control group (P < 0.0001); however, such a difference was not observed in terms of copper and magnesium serum levels.
Conclusion: Our study demonstrated that the serum iron and zinc levels were lower in PXF patients. Nutritional deficiency may be a cause of zonular weakness in these patients. Heme is a cofactor for the enzyme which contributes to the biosynthesis of fibrillin, the major protein in zonular fibers. Therefore, iron can play a substantial role in the biosynthesis of the fibrils and also in the zonular stability
Antibiotic Self-Medication and Risk Factors among Medical Students in an Iranian University: a Cross Sectional Study
Background: Self-medication with antibiotic is a widely prevalent practice all over the world especially among medical students. This study was aimed to evaluate the prevalence and the pattern of self-medication among medical students in Tehran, Iran.
Materials and Methods: A cross-sectional questionnaire-based study was conducted among the undergraduate medical students from a referral university in Tehran, Iran. All data obtained were analyzed using the statistical package for social sciences program (SPSS) version 20.
Results: A total of 201 students were enrolled in the current study. According to the analysis, 129 (64.1%) of the study population reported that they have self-medicated with antibiotics at least once in their student life. The principal morbidities for seeking self-medication include cough and common cold (23.4%) followed by fever (14.9%). The most frequent antibiotics used to self-medicate the mentioned morbidities were: amoxicillin (62%), co-amoxiclav (19.4%), penicillin (17%), cefixime (16%), azithromycin (14%) and tetracycline (9%). The majority of the participants stated cost saving, convenience and lack of confidence as their reasons for self-medication. The drug selection was mostly based on opinion of family members (31.8%), their own experience (27.4%) and the least commonly reported was selection based on recommendation by net citizens (0.5%).
Conclusion: Our study indicates that self-medication is widely practiced among students of the college. In this situation, the health care system should create as effective awareness and educate their students regarding advantages and disadvantages of self-medication
Tumor-derived urinary exosomal long non-coding RNAs as diagnostic biomarkers for bladder cancer
Bladder cancer (BC) is the sixth most common malignancy in men and 17th in women. Exosomal long non-coding RNAs (lncRNAs) have been defined as a novel biomarker for BC. The aim of this study is to evaluate the clinical significance of urine exosomal PVT-1, ANRIL and PCAT-1 as a biomarker in BC patients with tumors classified as T1 or T2. Exosomes were isolated from urine of BC patients and healthy donors, then characterized according to their shape, size, and exosome markers by Electron Microscopy, Dynamic light scattering, and Western blotting. Exosomal lncRNAs extraction was done to determine the expression levels of PVT-1, ANRIL and PCAT-1 by qRT-PCR. ANRIL and PCAT-1 expression was significantly higher in BC patients compared to normal subjects. To evaluate the performance of the identified lncRNAs for BC detection, we performed ROC curves analysis. The diagnostic accuracy of ANRIL and PCAT-1, measured by AUC, was 0.7229 (sensitivity = 46.67 % and specificity = 87.5 %) and 0.7292 (sensitivity = 43.33 % and specificity = 87.5 %). Transcript levels of lncRNAs in urinary exosomes are potential diagnostic biomarkers in bladder cancer
Antihemolitička aktivnost trideset biljnih ekstrakata u mišjim eritrocitima
Reactive oxygen species (ROS) can lead to haemolysis and eventually to diseases such as thalassemia and sickle cell anaemia. Their action can be counteracted by the antihaemolytic activity of therapeutic agents. The aim of our study was to identify plants that most efficiently counteract ROS-caused haemolysis. From ten plants known for their antioxidant activity (Orobanche orientalis G. Beck, Cucumis melo L., Albizzia julibrissin Durazz, Galium verum L., Scutellaria tournefortii Benth, Crocus caspius Fischer & Meyer, Sambucus ebulus L., Danae racemosa L., Rubus fruticsos L., and Artemisia absinthium L.) we prepared 30 extracts using three extraction methods (percolation, Soxhlet, and ultrasound-assisted extraction) to see whether the extraction method affects antihaemolytic efficiency, and one extraction method (polyphenol extraction) to see how much of this action is phenol-related. Extract antihaemolytic activity was determined in mice red blood cells and compared to that of vitamin C as a known antioxidant. Nine of our extracts were more potent than vitamin C, of which G. verum (aerial parts/percolation) and S. tournefortii (aerial parts/polyphenol) extracts were the most potent, with an IC50 of 1.32 and 2.08 μg mL-1, respectively. Haemolysis inhibition depended on extract concentration and the method of extraction. These plants could provide accessible sources of natural antioxidants to the pharmaceutical industry.Reaktivni kisikovi spojevi (ROS) mogu dovesti do hemolize te u konačnici do bolesti poput talasemije i anemije srpastih stanica. Takvo se djelovanje može ublažiti ili spriječiti terapijskim djelovanjem antihemolitika. Cilj je ovog istraživanja bio izdvojiti biljke koje najuspješnije sprječavaju hemolizu uzrokovanu reaktivnim kisikovim spojevima. U tu smo svrhu pripremili 30 ekstrakata biljaka poznatih po svojem antioksidacijskom djelovanju: Orobanche orientalis G. Beck, Cucumis melo L., Albizzia julibrissin Durazz, Galium verum L., Scutellaria tournefortii Benth, Crocus caspius Fischer & Meyer, Sambucus ebulus L, Danae racemosa L., Rubus fruticsos L. te Artemisia absinthium L. Rabili smo tri uobičajene ekstrakcijske metode (perkolacija, Soxhlet i ultrazvučna ekstrakcija) kako bismo utvrdili utječe li metoda na anihemolitičku aktivnost ekstrakta te smo u nekoliko uzoraka ekstrahirali polifenole kako bi se vidjelo koliko je ta aktivnost povezana s njihovom razinom. Antihemolitičku smo aktivnost mjerili u mišjim eritrocitima i usporedili je s onom vitamina C, koji je poznati antioksidans. Izdvojeno je devet ekstrakata sa snažnijom aktivnosti od vitamina C, od kojih su ekstrakti G. verum (zračni dijelovi/perkolacija) odnosno S. tournefortii (nadzemni dijelovi/polifenoli) bili najsnažniji, s inhibicijskom koncentracijom (IC50) od 1,32 odnosno 2.08 μg mL-1. Inhibicija hemolize ovisila je o koncentraciji ekstrakta te o metodi ekstrakcije. Ove bi biljke mogle poslužiti farmaceutskoj industriji kao lako dostupni izvori prirodnih antioksidansa
Medium Optimization for Synaptobrevin Production Using Statistical Methods
Background: Botulinum toxin, the most potent biological toxin, has become a powerful therapeutic tool for a growing number of clinical applications. Molecular studies have identified a family of synaptic vesicle-associated membrane proteins (VAMPs, also known as synaptobrevins) which have been implicated in synaptic vesicle docking and fusion with plasma membrane proteins.Materials and Methods: Using the synaptobrevin as a substrate for in vitro assay is the method to detect BoNT activity. We have been working on optimizations of bacterial expression conditions and media for high-level production of synaptobrevin peptide. Statistics-based experimental design was used to investigate the effect of medium components (E. coli strain, peptone, IPTG, yeast extract, ampicillin, and temperature) on synaptobrevin production by E. coli.Results: A 24 fractional factorial design with center points revealed that IPTG and temperature were the most significant factors, whereas the other factors were not important within the levels tested. This purpose was followed by a central composite design to develop a response surface for medium optimization. The optimum medium composition for synaptobrevin production was found to be: IPTG 29 mM, peptone 10 g/L, yeast extract 5 g/L, temperature 23°C and ampicillin 100 mg/L. This medium was projected to produce, theoretically, 115 mg/Lsynaptobrevin.Conclusion: The optimum medium composition synaptobrevin production was found to be: BL21 (E.coli strain), LB medium (peptone 10 g/L, Yeast 5 g/L), Ampicillin (100 mg/L), IPTG (0.29 mg/L) and temperature (23°C)
Study of the inhibitory effect of the small molecule Diethylthia tri carbocyanine iodide, as an anti- Alzheimer's candidate drug on human recombinant tau aggregation
Background and aims: Alzheimer’s disease is a neurodegenerative disorder that is affected by different factors. Forming aggregations of the tau proteins in the brain is one of the most commonly observation in the patients’ brains suffered from this disease. Several strategies have been devised to target the tau aggregates in the neuronal cells of the patients. Recently, chaperones have drawn the attention of the researchers as a tool to inhibit or disaggregate the tau protein aggregations. The aim of this study was to investigate the effect of small molecule chaperone called Diethylthia tri carbocyanine iodide on the formation of tau aggregates. Methods: In this basic laboratory study, Tau protein was expressed in bacteria. Then, Tau protein was purified by the ion-exchange chromatography and affinity chromatography, and its purity was evaluated by SDS-PAGE. Heparin was added as the inducer of tau aggregation, and the inductive effect of heparin on tau aggregation was examinated by circular dichroism (CD) method. Then, Diethylthia tri carbocyanine iodide chaperones was added to the aggregated tau and its effect was evaluated using SDS-PAGE and thioflavin T fluorescence assay. Results: Electrophoresis SDS-PAGE confirmed the expression of tau protein and its purity. CD validated the successful induction of tau aggregation by heparin. Following treatment of the tau aggregates with Diethylthia tri carbocyanine iodide, the results of SDS-PAGE showed that induced aggregation, remarkably reduced compared to the control sample. Thioflavin T fluorescence assay was used to confirm the results of SDS-PAGE analysis. Conclusion: The results of this study showed that Diethylthia tri carbocyanine iodide could inhibit the aggregation of the tau protein which they were produced in the presence of heparin inductor. These results can propose Diethylthia tri carbocyanine iodide as a potential treatment to target the tau aggregates in people with Alzheimer’s disease
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