Effect of nitric oxide and its intracellular signal

زمینه و هدف: نیتریک اکساید مولکولی فعال و ناپایدار است که در تنظیم بسیاری از اعمال اسپرم، منجمله واکنش آکروزومی و کموتاکسی اسپرم نقش دارد. هدف از این مطالعه بررسی اثر نیتریک اکساید و cGMP (cyclic Guanosine Mono Phosphate) در حرکت پیشرونده اسپرم انسان می باشد. روش بررسی: در یک مطالعه تجربی بعد از انکوباسیون اسپرم نمونه های منی افراد سالم (20 نمونه) به مدت 90 دقیقه در حضور ODQ (مهار کننده آنزیم گوانیلات سیکلاز محلول)، GSNO (دهنده نیتریک اکساید)، cGMP 8-bromo- (آنالوگcGMP)، ODQ+GSNO و گروه کنترل، حرکت پیشرونده اسپرم توسط سیستم کامپیوتری آنالیز کننده اسپرم (CASA) در فواصل زمانی 30، 60 و 90 دقیقه مورد ارزیابی قرار گرفت. داده ها با استفاده از آزمون t زوجی تجزیه و تحلیل شدند. یافته ها: حرکت پیشرونده اسپرم در انکوباسیون با GSNO به میزان 1/4 در دقیقه 90 و با cGMP 8-bromo- به میزان 4 در دقیقه 60، نسبت به گروه کنترل افزایش یافت (05/0

A comparative analysis of particle tracking in a mixer by discrete element method and positron emission particle tracking

Characterisation of particle flow using Positron Emission Particle Tracking (PEPT) is based on tracking the position of a single particle in a dynamic system. Recent developments in PEPT have facilitated tracking multiple particles aiming at improvements in data representation. Nevertheless for systems with a wide residence time distribution and/or dead zone, the conditions for getting representative data which could reflect the bulk behaviour of the powders need to be analysed and specified. In the present work, an attempt is made to simulate PEPT experiments for a paddle mixer using Discrete Element Method (DEM), with a view to investigate the effect of increasing the number of tracers on their time-averaged velocity distribution and whether it can represent the data on whole population of particles. The time averaged velocity distribution of the individual tracer particles (resembling simulated PEPT) is obtained and compared with the time averaged data on entire particle population. The DEM results indicate that for the investigated paddle mixer, it takes 251. s for one tracer to travel adequately in all the active space of the system. The instantaneous tracer velocity fluctuates around the average value obtained for all the particles, suggesting that the average tracer velocity is adequately representative of the average particle velocity in the system. The data of the PEPT experiment with one tracer with those of DEM with one tracer are in good agreement; however, DEM simulation suggests that increasing the number of tracers in the paddle mixer system does not influence the average velocity distribution. Furthermore, the velocity for all particles in the DEM shows a smooth distribution with a peak frequency of the velocity distribution that is lower than PEPT and DEM tracer. When tracking a single tracer in DEM or PEPT, it may not be detected to have zero velocity at any instant of time, whilst the data for all particles show that about 0.3% of particles are stagnant

Nitric oxide metabolite levels during the ectopic osteoinduction in rats

Abstract Nitric oxide (NO) is a cell-signaling molecule that has diverse biological functions. Recent evidence suggests that its production may regulate the metabolism of the osteoblasts and osteoclasts. The aim of this study was to evaluate levels of nitrite and nitrates (NO metabolites) during ectopic osteoinduction in rats. Eighteen male Sprague–Dawley rats (body weight 200–300 g) were used in this study. All animals were anesthetized and the right and left flank areas were shaved, and under aseptic conditions, a muscular pouch was created in each flank: the left was filled with 20 mg of demineralized bone matrix and the right remained empty (sham). Radiographs were taken at 2, 4, and 6 weeks after surgery to trace the ectopic bone formation and muscle mineralization. Blood samples were taken before (as baseline values) and at 2, 4, and 6 weeks after surgery. The mean values of NO metabolites after 6 weeks were significantly higher (p<0.05) than baseline data and at 2 weeks post-surgery. Results from this study indicate that the ectopic osteoinduction caused increased activity of the osteoblasts which subsequently caused increased serum levels of NO metabolites (nitrites and nitrates)

Cellular immune response of infectious bursal disease and Newcastle disease vaccinations in broilers exposed to monochromatic lights

To investigate the effects of various monochromatic lights on T lymphocytes proliferation and serum nitric oxide production in chicken vaccinated with infectious bursal disease and newcastle disease vaccines, a total of 60 one-day-old broilers were exposed to red, green, blue, white and yellow light by using a light-emitting diode system for 6 weeks. The results indicated that the proliferation of peripheral blood T lymphocytes in the chickens exposed to white and green lights significantly increased when compared with other groups at 37 days of age (P &lt; 0.05). In the early days, the results were different. The enhancement of T lymphocytes proliferation with green and yellow lights occurred at 18 days, whereas the enhancement with green light was less than other lights at 30 days. Red light promoted NO (nitrix oxide) production at maximum level in the chickens, while green light suppressed it at minimum level after 37 days. These results suggested that green and white lights had strong effects on immunity, especially at the last days of rearing.Key words: Monochromatic lights, vaccination, nitric oxide, broiler chicken

The devices, experimental scaffolds, and biomaterials ontology (DEB): a tool for mapping, annotation, and analysis of biomaterials' data

The size and complexity of the biomaterials literature makes systematic data analysis an excruciating manual task. A practical solution is creating databases and information resources. Implant design and biomaterials research can greatly benefit from an open database for systematic data retrieval. Ontologies are pivotal to knowledge base creation, serving to represent and organize domain knowledge. To name but two examples, GO, the gene ontology, and CheBI, Chemical Entities of Biological Interest ontology and their associated databases are central resources to their respective research communities. The creation of the devices, experimental scaffolds, and biomaterials ontology (DEB), an open resource for organizing information about biomaterials, their design, manufacture, and biological testing, is described. It is developed using text analysis for identifying ontology terms from a biomaterials gold standard corpus, systematically curated to represent the domain's lexicon. Topics covered are validated by members of the biomaterials research community. The ontology may be used for searching terms, performing annotations for machine learning applications, standardized meta-data indexing, and other cross-disciplinary data exploitation. The input of the biomaterials community to this effort to create data-driven open-access research tools is encouraged and welcomed.Preprin

CFD Modeling of Wing and Body of an AUV for Estimation of Hydrodynamic Coefficients

Coefficients or hydrodynamic derivatives of autonomous underwater vehicles (AUVs) play a key role in their design and maneuverability. Using a suitable method to estimate these coefficients serves as a time efficient approach to raise the achievable precision in the design and control of AUVs. This paper estimates hydrodynamic derivatives of an AUV using computational fluid dynamics (CFD) for the wings and body. CFD modeling was performed to simulate captive model tests including straight line and planar motion mechanism (PMM). In such runs, the process was implemented separately for the wing and body. Experimental tests for the same AUV in the water tunnel were carried out for CFD validation. Comparing the numerical results to the experimental data, it was shown that the modeling method is able to estimate these coefficients at reasonable accuracy. The proposed modeling method was proved to be efficient in estimating hydrodynamic derivatives and hence can reduce associated computational costs with the process of detail design of AUVs

Treatment Failure in Cutaneous Leishmaniasis Patients Referred to the School of Public Health, Tehran University of Medical Sciences During 2008-2017

Background: Cutaneous leishmaniasis (CL) is a vector borne disease predominantly found in tropical and subtropical countries, including Iran. For more than 6 decades, pentavalent antimonials have been used successfully worldwide for the treatment of leishmaniasis, but over the past few years, clinical resistance to these medications has increased. In this study, we evaluated CL patients who did not show any desirable responses to the anti-leishmanial treatment within a 10-year period (2008 to 2017). Methods: All patients from different parts of Iran suspected of having cutaneous leishmaniasis, who were referred to the laboratory of leishmaniosis in Tehran University of Medical Sciences from 2008-2017 were parasitological examined. Results: During this period, a total of 1480 suspected CL patients were referred to the laboratory of leishmaniosis. Samples from 655 patients (70.8) suspected of having CL were positive microscopically. The failure rate in patients treated with anti-leishmaniasis medications for a minimum of three complete treatment periods was 1.83 (12 cases). There was no association between the number and size of skin lesions and patient characteristics. Also, the route of drug administration had no significant effect on the number and size of lesions. Conclusion: In the present study, treatment failure was found in some confirmed CL patients treated with meglumine antimoniate. Over the past few years, it seems that had been increased in resistance to these medications. So, a review of the correct implementation of the treatment protocol and/or a combination therapy may be helpful in preventing an increase in the rate of treatment failure