مجله طب دریا
سال چهارم شماره 4 (پیاپی 17، زمستان 1401)

The increase in population and the development of various industries have caused a large number of pollutants to enter the water environment. One of the major environmental pollutants is heavy metals. Due to characteristics such as chemical stability, poor degradability, and the power of bioaccumulation at different levels of the food chain, these metals cause harm and ecological risks to living organisms. Every year, toxic and chemical effluents enter rivers, seas, and oceans during agricultural and industrial activities without observing environmental considerations, which has caused water, sediments, and aquatic pollution and created many problems for the environment and humans. Regarding the pollution of heavy metals in the water and sediments of the Persian Gulf, many studies have been conducted, some of which indicate the presence of pollution in the water and sediments. In the present study, a comprehensive review of the studies conducted regarding heavy metal pollution in water and sediments of Persian Gulf coasts has been done.

Due to their active and stressful life, military personnel needs special nutrition. Nutritional supplements are meant to complement a healthy diet that includes vitamins, minerals, medicinal plants, amino acids, enzymes, and macronutrients. The depletion of muscle and liver glycogen reserves leads to a decrease in concentration, fatigue, and a decrease in physical and mental performance. Moderate to vigorous physical activity, one to three hours per day, requires 6 to 10 grams of carbohydrates per kilogram of body weight. It has been shown that the consumption of fat, including a high dose of conjugated linoleic acid (CLA) and omega-3, is effective in testosterone production, an issue that can be important for active people such as military forces due to the anabolic effects of testosterone. In people with vigorous physical activity, it is recommended to receive 1.4 to 2 grams of protein per kilogram of body weight, which is higher than in general people. Also, branched-chain amino acids (BCAA) compete with tryptophan in crossing the blood-brain barrier, delaying the feeling of fatigue. Excessive amounts of antioxidants in the form of supplements in people with vigorous physical activity disrupt the adaptation to physical activity and are not recommended. Vitamin D, iron, and zinc are involved in many natural functions of the body, and due to the special conditions of the military forces, there is a possibility of a lack of these nutrients in these people. This deficiency can endanger a person's physical performance and even health. Therefore, special attention should be paid to their adequate intake in the diet. Caffeine, nitrate, and creatine are among the substances that are effective in delaying the feeling of fatigue and have attracted the attention of people with vigorous physical activity. These nutrients can help military personnel during operations and increase their efficiency. In general, getting enough nutrients is very important for military personnel. Due to the special conditions during military operations, it is not possible to receive meals that can provide all the necessary nutrients. On the other hand, due to vigorous physical activities, the rate of metabolism, as well as the loss of nutrients in these people, is more than in general people, which increases the amount of need. Therefore, in order for the military forces to be able to have their maximum efficiency and also to prevent injuries and diseases that can have great costs and consequences for a country, the use of nutritional supplements to improve the nutritional status of these people can be considered.

To overcome the crisis of antibiotic resistance, the development of more effective antibiotics without side effects is an urgent need. Meanwhile, the bacteria associated with sea sponges have a good potential for discovering new antimicrobial compounds with a large variety of secondary metabolites. The present study was conducted with the aim of determining the antimicrobial activity of bacteria associated with the marine sponge Haliclona sp collected from the Persian Gulf.

In the present study, the antimicrobial effects of bacteria associated with the marine sponge Haliclona sp. collected from Lark and Kish islands in the Persian Gulf, were studied against Gram-positive bacterium Micrococcus luteus. After identifying and separating the samples, purification of sponge-related bacteria was done. Isolation and purification were done on culture media including Starch caseinnitrate agar, Marine zobell agar, Glycerol asparagine agar, Marinesponge agar. Then, in order to screen the biological activities of the purified bacteria, a nutrient broth culture medium was used. Finally, the antimicrobial activity of the isolated bacteria was measured using the well diffusion method against the gram-positive bacterium Micrococcus luteus.

The highest amount of bacteria associated with the sponge Haliclona sp. related to MSA, SCNA, MZA, and GAA culture media with the isolation of CFUg-1, were 5.88±0.05, 4.87±0.05, 4.20±0.03 and 2.75±0.23 related to sponges collected from Lark Island and 6.15±0.07, 5.08±0.05, 4.90±0.07 and 4.19±0.19 related to the sponges collected from the Kish island, respectively. As a result of purification, nearly 121 bacterial strains were purified, of which 12 purified bacterial strains had antibacterial activity.

The current findings demonstrated that the marine sponge Haliclona sp. has significant antibacterial effects; as a result, this marine sponge is a suitable candidate in future studies for the isolation of effective antibacterial compounds.

Occupational stress in the Intensive Care Unit (ICU) has a serious impact on the health and quality of life of nurses. Paying attention to the quality of life of nurses and reducing occupational stress can lead to better provision of medical services in the ICU and hospital. Therefore, the present study was conducted to determine the relationship between occupational stress and quality of life in ICU nurses in selected naval hospitals.

In this descriptive-analytical study, 76 ICU nurses in selected naval hospitals in the south of Iran in 2019 participated. Sampling was done by census and available methods. The research tools included the 26-question quality of life (WHOQOL-BREF) and occupational stress questionnaires, which were completed by nurses, and then data were analyzed.

The mean score of occupational stress and quality of life in ICU nurses in selected naval hospitals were estimated as 42.9±1.7 and 62.3±19.1 respectively, both of which are at a moderate level. Occupational stress has an inverse and significant relationship with quality of life in ICU nurses. Occupational stress and quality of life had no significant relationship with any of the ICU nurses' demographic variables.

The findings of the present study demonstrated that there is a significant and inverse relationship between the quality of life and occupational stress in ICU nurses, so the increase in occupational stress of ICU nurses has a negative effect on their quality of life, and this can affect the quality of providing clinical care in hospital. Therefore, improving the quality of life and reducing occupational stress should be on the agenda of health officials.

Social capital is an important asset of any organization that can contribute to knowledge management and creates a sustainable competitive advantage for organizations. The aim of this research was to determine the relationship between social capital and knowledge sharing as the heart of knowledge management in a military hospital, and the organizational knowledge dimensions were investigated as an effective organizational factor in the knowledge management process as a mediating role.

This is applied survey research that structural equation modelling is used for analysis. The statistical population includes managers and employees of the selected military hospital in Tehran, Iran in 2019. To collect data, standard questionnaires were used for organizational knowledge dimensions, knowledge sharing, and social capital.

Social capital had a significant effect on knowledge sharing (effect coefficient 0.450). The findings of the research emphasized increasing the organization's knowledge culture, knowledge leadership, strengthening knowledge resources, giving importance to knowledge portals, and paying attention to the appropriate knowledge structure, and processes for easy access to knowledge.

The organizational knowledge dimensions play a very effective role in increasing knowledge sharing, and in addition to its direct effect on increasing knowledge sharing, it also increases the effect of social capital on knowledge sharing, so the importance of knowledge dimensions in increasing sharing knowledge in military centers should be considered.

Spirulina platensis microalgae contain strong antioxidants and its health properties are related to antioxidant pigments, carotenoids, chlorophyll, and blue pigment unique to its phycocyanin. In this research, the amount of phycocyanin, beta-carotene, chlorophyll a and b were evaluated in Spirulina platensis microalgae.

In this experimental study, Spirulina platensis strain was cultured in Zarrouk liquid medium. Then the microalgae were dried and ground. The amount of beta-carotene at the wavelength of 451 nm and the amount of chlorophyll at the wavelength of 665 nm were read. The amount of phycocyanin in Spirulina platensis was calculated after reading at wavelengths 280 and 620 nm.

In Spirulina platensis microalgae, the amount of chlorophyll a was 0.8 mg/g and chlorophyll b was 0.2 mg/g. The amount of phycocyanin was 0.9 mg/g. The amount of beta-carotene was 7.9 g/100g. Antioxidant compounds include propyl gallate > 2.5 mg/kg, butylhydroquinone > 2.5 mg/kg, butylated hydroxyanisole > 2.5 mg/kg, butylated hydroxytoluene 208 mg/kg and the total amount of antioxidants > 215.5 mg/kg was recorded.

According to the current findings, Spirulina platensis microalgae has a high antioxidant capacity and can be useful in terms of nutrition, which of course needs more studies.

Bioterrorism is an important health and social issue in the world. This research was conducted with the aim of determining the knowledge and attitude of students regarding bioterrorism in a military medical science university.

This cross-sectional study was conducted in 2021. The study population included all students studying at a university of military medical sciences in Tehran, Iran. A sample size of 300 students was calculated and demographic data were recorded. The data collection tool was the standard questionnaire of students' knowledge and attitude regarding bioterrorism.

The mean and standard deviation of students' knowledge and attitude scores regarding bioterrorism were 8.15±2.11 and 12.35±2.35, respectively. Low knowledge and attitude were reported in 63 and 72 percent of students, respectively. The mean score in the domain of decontamination and maintenance of bioterrorism victims was 3.56 and in the domain of factors causing bioterrorism was 1.25. The most important sources of students' information about bioterrorism were radio and television, followed by newspapers and magazines.

Low knowledge in students about bioterrorism can increase the probability of risks related to bioterrorist attacks. Therefore, educational programs and workshops about bioterrorism for students can be effective in increasing the level of students' knowledge and attitude.

Lactobacillus plantarum probiotic is one of the probiotics used in aquatic nutrition. The aim of this study was to evaluate the effect of L. plantarum probiotic on the growth indices and blood parameters in juvenile common carp (Cyprinus carpio).

In this study, 180 juvenile common carp (Cyprinus carpio) with a mean weight of 15.32±0.16 g were randomly assigned to two experimental treatments with three replicates (30 pieces per repetition) including a commercial diet (control treatment) and a diet containing L. plantarum probiotics at 107 CFU/g (experimental treatment). The duration of the study and treatments was 60 days.

The final weight, weight gain, specific growth rate, status index, and feed conversion ratio in the treatment containing L. plantarum had a significant increase compared to the control group (P <0.05). Also, the addition of L. plantarum probiotic to juvenile common carp diet increased the number of white blood cells compared to the control group (P<0.05); while it had no significant effect on other blood parameters.

The present findings showed that the use of L. plantarum probiotic improved growth indices (final weight, weight gain, specific growth rate, condition index, and food conversion ratio) and also increased the number of white blood cells in juvenile common carp (Cyprinus carpio).