Research Progress of Coal Damage under Unsteady Load in China

Coalbed methane mining, suppression of coal dust, and elimination of dynamic disasters are closely related to the expansion of coal body cracks and internal damage. Understanding the expansion mechanism of pore-cracks is critical to investigate coal body damage. In this study, research from 2016 to 2021 conducted on the coal damage mechanism in China was sorted and the progress in this field was analysed to systematically investigate coal body damage. Critical topics of research in this field in recent years were identified, and load types were classified into static and dynamic loads. Dynamic loads with obvious characteristics and considerable damage-increasing effects were classified into impacting, cyclic, pulsating, and other dynamic load types. The current load-generating devices, various detection techniques and methods, research results, and the future research directions under various load types were discussed. The current coal damage research is primarily based on macrocharacteristic analysis and the stage characteristics of characterisation variables. The use of scanning electron microscopy, computerised tomography three-dimensional reconstruction technology, and acoustic emission technology can reveal the pore propagation mechanism at the micro level.

Stress, distress, its types and correction

Chronic and acute, physiological, psychological and informational stress are considered. It is noted that stress is a protective reaction of the body in response to a very strong emotional, physical or psychological action from the outside. Instead, distress develops as a result of: prolonged inability to meet their physiological needs, unpleasant, sad and threatening changes in life, unusual, inappropriate living conditions, body damage, illness, injury, prolonged pain or negative emotions. The best way to deal with stress is to prevent it: regular walks in the fresh air, sports, adequate sleep and more. ADAPTOL® anxiolytic helps to curb excessive anxiety and irritability, to restore strength after the transferred stress.

Three Polymers from the Sea: Unique Structures, Directional Modifications, and Medical Applications

With the increase of wounds and body damage, the clinical demand for antibacterial, hemostatic, and repairable biomaterials is increasing. Various types of biomedical materials have become research hotspots. Of these, and among materials derived from marine organisms, the research and application of alginate, chitosan, and collagen are the most common. Chitosan is mainly used as a hemostatic material in clinical applications, but due to problems such as the poor mechanical strength of a single component, the general antibacterial ability, and fast degradation speed research into the extraction process and modification mainly focuses on the improvement of the above-mentioned ability. Similarly, the research and modification of sodium alginate, used as a material for hemostasis and the repair of wounds, is mainly focused on the improvement of cell adhesion, hydrophilicity, degradation speed, mechanical properties, etc.; therefore, there are fewer marine biological collagen products. The research mainly focuses on immunogenicity removal and mechanical performance improvement. This article summarizes the source, molecular structure, and characteristics of alginate, chitosan, and collagen from marine organisms; and introduces the biological safety, clinical efficacy, and mechanism of action of these materials, as well as their extraction processes and material properties. Their modification and other issues are also discussed, and their potential clinical applications are examined.

Kelebihan dan kekurangan penggunaan radiasi dosis rendah (Low Doses Radiation: advantages and disadvantages)

Objectives: To inform and discuss the benefits and harms of low dose radiation. Literature Review: Low dose radiation (LDR) was often used, including for services in the field of dentistry. Several studies have studied this for a long time but the results are still not conclusively agreed. Some researchers found a variety of side effects that are not beneficial to the body, but some found no association with the body damage caused by this, and even some found that LDR has beneficial effects on the body. Conclusion: low doses of radiation cause significant changes in the body, although this condition is met with an adaptive reaction which is considered a beneficial response by the body. Therefore, no matter how small the radiation is given, it will still have an impact on the body so it is better to be wise in its use.

The vascular nature of COVID-19

A potential link between mortality, D-dimer values and a prothrombotic syndrome has been reported in COVID-19 patients. The National Institute for Public Health of the Netherlands published a report for guidance on diagnosis, prevention and treatment of thromboembolic complications in COVID-19 with a new vascular disease concept. The analysis of all available current medical, laboratory and imaging data on COVID-19 confirms that symptoms and diagnostic tests can not be explained by impaired pulmonary ventilation. Further imaging and pathological investigations confirm that the COVID-19 syndrome is explained by perfusion disturbances first in the lung, but consecutively in all organs of the body. Damage of the microvasculature by SARS 1 and SARS 2 (COVID-19) viruses causes microthrombotic changes in the pulmonary capillaries and organs leading to macrothrombosis and emboli. Therefore anticoagulant profylaxis, close lab and CT imaging monitoring and early anticoagulant therapy are indicated.