مجله طب دریا
سال پنجم شماره 2 (پیاپی 19، تابستان 1402)

Noise annoyance is considered a significant injury in military personnel and has the ability to affect their combat performance. The purpose of this study is to determine the characteristics of sound in the occupational exposure of employees to military vessels.

This cross-sectional study was conducted on N-class and T-class vessels near Mahshahr city in 2022. Sound measurement and octaband analysis were done using sound meter and acoustic calibrator. In N-class and T-class vessels, the analysis of the sound pressure level was analyzed in the stationary state and in the state while moving with engine speed of 1300 and 1700 rpm. The collected data were analyzed in Minitab 21 software.

The findings showed that the sound pressure level in the switched on state is less than the standard limits at frequencies of 250, 500, 1000, 2000, 4000 and 8000 Hz. But in the on state during movement and with the engine speed of 1700 rpm in both N-class and T-class vessels, engine number 2 has the highest sound pressure level with a difference of 18.8 and 14.9 dB compared to the standard limits. Also, at the frequency of 250 Hz, among the distance measurement of different engines, the biggest difference in sound pressure level (-29.6 dB) with the standard limits is related to the right engine of the N-class vessel.

The findings of the present study demonstrated that the sound pressure level in the switched on state does not cause any damage to the hearing of military personnel, because in all the measured frequencies, the sound pressure level was reported to be lower than the standard limits. It is recommended to use personal protective equipment for employees during military operations or to install a high-performance absorber in the cabin of both vessels during occupational exposures to reduce the harmful effects of noise.

Psychological distress is one of the psychological problems that is related to a wide range of mental disorders. Considering the role of military personnel in creating social security, paying attention to their mental health has particular importance. In this study, the prevalence of psychological distress in the military personnel of Razavi Khorasan province, Iran was estimated and demographic factors related to it were identified.

In this cross-sectional study, military personnel who referred to the health centers of Mashhad city in the first half of 2019 were examined. Data was collected using the demographic checklist and Kessler's standard scale of psychological distress (K-6) from the SINA system of health centers in Razavi Khorasan province, Iran. The total score of 10 and more in the K6 questionnaire was considered as the cut-off point. The K6 questionnaire evaluates people's feelings in 6 areas: discomfort, restlessness, nervousness, helplessness, hopelessness, sense of worthlessness in the last month

Out of 4488 military personnel, 98.7% were men, 51.7% were married, and 44.5% had a diploma. The mean psychological distress score was 3.39±4.45 out of 24 and the prevalence of psychological distress was 12.6%. Gender (p=0.024), education level (p<0.001) and place of residence (p=0.001) were associated with the prevalence of distress. The prevalence of psychological distress was higher in women, singles, military personnel with less than a diploma, and residents of cities between 50 and 500 thousand people.

The prevalence of psychological distress was estimated to be moderate in comparison with the studies conducted in other countries. Senior military managers can prevent the occurrence of more serious mental disorders as well as the creation of problems in their subordinate organizations with proper planning in the direction of screening patients.

Defense of the country is the duty of the armed forces, the aim of this study is evaluation of the effect of self-talk exercises on the physical fitness factors in students.

This is a semi-experimental study with a pre-test-post-test design. The statistical population was the students of Imam Ali Officers University, Tehran, Iran in 2022, 30 of them were selected by available sampling and randomly assigned into 2 intervention (n=15) and control (n=15) groups. In the pre-test, the time of each student in running 70 meters and carrying the injured was measured. Then, in a meeting, the intervention group was taught self-talk and how to practice it, and they did 10 self-talk exercises along with their daily physical exercises. The control group only practiced the physical exercises. After the completion of 10 training sessions, the post-test was performed as the pre-test.

In the self-talk intervention group, after 10 training sessions, the mean performance in the 70-meter run significantly decreased from 9.44±1 to 8.72±0.82, and the mean carrying the injured significantly decreased from 9.41±1.73 to 8.70 ±1.11. The mean running time of 70 meters in the control group was decreased from 9.38±0.93 to 9.36±0.88 seconds and also, the mean carrying of injured in this group was decreased from 9.52±1.43 to 9.49±1.42 seconds, which was not significant (P<0.05).

In general, these findings showed that after self-talk, the performance of students improved. Therefore, it is suggested that the coaches and commanders of the army consider self-talk exercises along with their physical programs to improve the students' performance.

Considering the importance of the kinematic role of the lower limb in absorbing the forces entering the body, the aim of this study is to investigate the effect of the kinematics of the lower limb on the occurrence of Medial tibial stress syndrome (MTSS) injury in soldiers during the military training period.

In the present study, male soldiers were examined during the 6 months of military training in 2022, and 116 of them were selected. At the beginning of the training course, while investigating the prevalence of MTSS using the Yates criterion and the kinematic data, subjects' landing and knee valgus dynamics were collected by video camera and Quinoa software. Then the soldiers started to do exercises related to military training, and at the end of the 6-month period, the possible prevalence of MTSS was evaluated again using the Yates and White criteria.

The prevalence of MTSS in military soldiers at the end of the period was 29.3%. The results of logistic regression to investigate the predictive role of knee valgus at the moment of single leg landing in the occurrence of MTSS injury showed that the final model was able to explain between 57.6% and 82.0% of the variance. For knee valgus at the moment of two-leg landing, between 54.5% and 77.6% variance, single-leg landing hip flexion between 60.5% and 86.2% variance, two-leg landing hip flexion between 65% and 92.7% of the variance, the knee flexion at the end of one leg landing between 65.3% and 93.1% of the variance and finally for the knee flexion at the end of two legs landing, the final model was able to explain between 44.44% and 63.2% of the variance. The odds ratio related to knee valgus at the moment of one-leg landing is 2.204, in knee valgus at the moment of two-leg landing, 1.773, in the thigh flexion variable at the end of single-leg landing, 2.491, in thigh flexion at the end of two-leg landing, 2.069, the knee flexion at the end of single leg landing is 2.163 and in the variable knee flexion at the end of two leg landing is 1.580. Among the variables, the thigh flexion variable at the end of single leg landing statistically has a higher predictive power than other variables for the occurrence of MTSS (2.491).

The current findings demonstrated that landing kinematics has an effect on the prevalence of MTSS, and these changes can be caused by the weakness of the muscles acting in the joints of the lower limbs, as well as an increase in excessive load caused by military exercises.

The rapid and continuous development of shrimp farming has probably led to a series of harmful developments for the environment and human health. The destruction of mangrove forests, the blooming of harmful algae in coastal waters and shrimp breeding ponds, the introduction of non-native species, the depletion of aquatic resources and the reduction of water quality are among the most important environmental problems. The widespread and unlimited use of antibiotics to prevent bacterial infections in the shrimp farming industry, especially in developing countries, has played a role in this regard. On the other hand, the use of large amounts of antibiotics that should be mixed with shrimp food also lead to some problems for human health and increases the chance of remaining antibiotics in meat and shrimp products. Therefore, it seems that global efforts are needed to promote a more rational use of preventive antibiotics in aquaculture. Because the evidence shows that this unlimited use is harmful to fish, animals, human health and the environment. It is suggested to plan according to the principles of sustainable use of the environment for various economic activities, including the construction of shrimp farms, and monitoring efforts are usually needed to predict possible effects. Aquaculture effluent monitoring is part of the assessments needed to understand environmental impacts, which may include measurements of water quality, nutrient concentrations, organic matter outputs, chemicals, and residual bacteria that affect product quality.

Complications caused by the use of chemical drugs such as antibiotics in aquaculture raise the necessity of using antimicrobial compounds that are compatible with the environment. Probiotics are live bacteria that have a significant impact on host health due to their ability to control infectious diseases. Due to the possible transmission of risks from live microbial strains to the host, the use of non-living microbial counterparts has been suggested. The non-living microbial part (paraprobiotic) like its living counterpart is used as a suitable substitute orally or by injection due to its beneficial effects on the host. Therefore, the use of paraprobiotic compounds, despite their high ability in comprehensive host microbial modulation, still needs to be evaluated more carefully. In this review study, the concept of paraprobiotics, the preparation of paraprobiotics and the evaluation of health indicators of paraprobiotics in order to modulate biological reactions are described.

Tetradotoxin is a powerful and deadly poison that has poisoned and killed countless people. The distribution of Tetradotoxin and its analogs is very wide and this toxin has been identified in many organisms. Increasing its detection in marine species such as bivalves and gastropods has drawn scientific and legal attention to this toxin. While Tetradotoxin is structurally completely different from saxitoxin, another marine toxin, their sodium channel blocking mechanism is the same and it has been shown that the potency of both can be combined. Google Scholar, Scopus and PubMed databases were applied for selecting the most relevant papers with the keywords "tetradotoxin", "poisoning", "mechanism of action", "bivalves", "edible gastropods" and "origin of tetradotoxin". The purpose of this review was to evaluate the public health risks that have endangered the lives of many people due to the consumption of tetrodotoxin and its analogs in bivalves and gastropods. The results of this study showed that this toxin is very resistant to heat and there are new and more accurate methods for its detection. Also, poisoning with this toxin can be both acute and chronic, and both of these cases can lead to the death of the consumer.