امیر حسینی

During sperm freezing, its functional indices, including survival and motility, are damaged and lead to a decrease in sperm quality and fertility. Studies have been performed to lower these damages, including adding antioxidants to the freezing environment. This study was conducted to investigate the effects of antioxidants melatonin and L-carnitine on the quality of sperm parameters after freezing and thawing.

In this interventional study, 40 sperm samples were divided into 4 groups including: control group (no antioxidant), melatonin group (0.01 mmol melatonin), L-carnitine group (100 μmol L-carnitine) and combined group (0.01 mmol melatonin and 100 μmol L-carnitine). The samples were thawed two weeks after freezing, then the motility, survival and morphology parameters were evaluated by Eosin-nigrosin staining and were counted. Lipid peroxidation was evaluated by measuring MDA with thiobarbituric acid reaction and DNA fragmentation through Tunnel kit.

The results showed that the combined use of melatonin and L-carnitine in the freezing medium had a significant effect on the rate of motility and survival (increase from 15% to 25%), DNA fragmentation (decrease from 32% to 23%) and MDA level (decrease from 10 to 6.5 µm/dl). However, the examination of sperm morphology did not show any significant difference between the studied groups.

The results of the study showed that melatonin and L-carnitine can reduce the damage caused by sperm manipulation during the freezing and thawing process.

Infertility is a disorder that affects about 15% of couples and 50% is related to male. Sperm freezing involves storing semen samples at -196°C in liquid nitrogen. During freezing, due to the induction of apoptosis through oxidative stress, the functional indicators of sperm are damaged and ultimately lead to a decrease in fertility. There have been many studies on the use of freezing environments with complementary antioxidants to limit the damage caused by freezing. In this study, melatonin and curcumin were used in combination as antioxidants in sperm freezing.

This study was conducted in 2022 on the semen of 40 men with normal sperm in Qazvin University of Medical Sciences. To check sperm motility by CASA device, morphology by hematoxylin staining, viability by eosin nigrosine staining, DNA integrity by tunnel kit and MDA measurement by reaction method with thiobarbituric acid and spectrophotometer were used. Data analysis was done using SPSS software (version 25) and ANOVA test, dependent t-test and one-way analysis of variance. P<0.05 was considered statistically significant.

The use of melatonin and curcumin either separately or in combination in the freezing environment had a significant effect on the rate of motility and survival, DNA fragmentation and MDA level (P<0.05).

Adding curcumin and melatonin in combination to the freezing environment will have a positive effect on sperm parameters after freezing.

In 1350, the first law of the country's trade union system was approved by the National Assembly and the Senate. According to the law, the trade union organization emerged as an independent organization in the country called the Chamber of Trade Unions. Given the importance of this issue, this study seeks to investigate the structure of the trade union system and the role of regulatory authorities, especially the Iranian police in improving the situation of trade unions and, consequently, increasing welfare and social security. Also, the gaps in the current law, which is one of the important factors in the poor performance of trade unions in guiding trade and market control, analysis and practical solutions to address these shortcomings, are presented. The structure and organization of trade unions and the activities of trade unions and their relationship with organizations, especially law enforcement, whose activities depend on this coordination. Lack of coordination and poor performance of trade unions and their relationship with organizations, especially with supervisory organizations such as law enforcement, will have consequences such as social dissatisfaction and, consequently, security dissatisfaction. The results show that the most important problems of guilds in Iran are: lack of up-to-date laws and gaps in the legal materials of guilds, lack of independence of guilds and dependence on the government, lack of accurate and regular supervision of competent supervisory authorities independent of guilds

One of the concerns of most social scholars is the commodification of altruistic activities. In the conventional economics, it sometimes happens that some human activities that concern supporting others are looked upon as commodities and trade of goods. This article deals with western scholars' view on the mentioned issue. Using a library research, the critical views of scholars such as Polany, Sandel, Slater, Tonkiss, Frey, are reviewed and their criticisms in two philosophical-fundamental and economic-psychological areas are taken into account. The sum of these views ultimately lead to three propositions: 1- literal commodification results in real commodification 2- monetary validation causes the emergence of crowding-out and framing effects among those involved 1- in regard to altruistic functions, internal impetus is more effective than external one.

The equations governing transient open-channel flow are continuity and momentum equations that are known as Saint-Venant equation. Based on the simplifications of this equation, numerical models of flood routing are categorized. Flood routing models include: dynamic wave models, kinematic models, hydrological Knox model and Maskingham model. In this research, basics of Saint-Venant equation and numerical dynamic wave model, kinematic, Knox and Maskingham models will be explained. Also their results are compared. Also their results are compared. For this purpose, an interval of Bastanak River between Badamak and Khanimen Hydrology stations is studied and a new mathematical relationship for prediction of maximum flood flow rate, river flood plain and maximum width of flood flow is presented. MIKE11 dynamic wave model was solved by partial differential methods and showed a better result with respect to other models. Routing and mathematical zoning of flood using hydrological Maskingham method showed minimum error compared to numerical MIKE11 method and observed flood when min square method used to calculate error.

The presence of distributed generations (DGs) in the power systems is causing problems such as increasing the short circuit current levels which may exceed the rating of existing circuit breakers and can damage system equipment. The utilization of fault current limiters (FCLs) in the network can be an effective method to overcome the above problems. Furthermore, FCL has the benefits such as improving the system security and reliability. FCL benefits depend on the number, installation location, and impedance of FCL. For this end, we require a method to determine the optimum number, impedance and locations for FCL placement. In the considered method, we have modeled the FCL placement as an optimization problem while the objectives are; bus fault current difference, reliability, the number and impedance of FCLs. Moreover, to solve the proposed problem, a new multi-objective optimization algorithm based on particle swarm optimization has been implemented. In the algorithm, several iterations have been considered, and the non-dominated solutions are extracted and stored in an external repository in the iterations. Finally, a fuzzy clustering technique is used to control the size of the repository during the algorithm evolution. The proposed approach is tested on a test system, namely, RBTS 2 . The obtained results demonstrate the effectiveness and feasibility of the new method.