UNASSIGNED: In the military, neck pain is second to low back pain among musculoskeletal disorders. However, the prevalence and related factors of neck pain in military personnel have not been systematically investigated, which may lead to the lack of neck pain prevention and the generation of additional medical expenses, posing challenges to medical care. This review aimed to obtain the prevalence and related factors for neck pain in military personnel in an attempt to provide directions for prevention and intervention.
UNASSIGNED: We searched PubMed, Embase, and Cochrane databases in December 2021. Two researchers independently screened studies according to eligibility criteria and assessed study quality.
UNASSIGNED: We screened titles and abstracts of 503 articles, and 17 articles met the inclusion criteria. Sixteen articles received moderate to high-quality evaluations. Neck pain is common in the military, with 1-year prevalence as high as 83% and lifetime prevalence as high as 78%. Old age (OR = 5.0), poor neck mobility (OR = 3.61), shoulder pain (OR = 4.9), low back pain (OR = 2.3), high-G pilots (OR = 1.6), longer flight time (OR = 2.53), type of aircraft (OR = 3.93), and use of helmets and night vision systems (OR = 1.9) may be associated with the prevalence of neck pain.
UNASSIGNED: Neck pain is highly prevalent in military personnel and exhibits a substantial lifetime prevalence rate. The high prevalence rate of neck pain in the military is related to many individual-related factors and work-related factors. The in-depth assessment and prevention of specific factors is an important direction of future research.

Currently, the research and application of biochar in the remediation of heavy metal contaminated soil has become a hotspot, especially regarding the remediation of agricultural land. Biochar has been proved to be effective in reducing the content of available heavy metals in the soil as well as the heavy metals in plants. However, the long-term effectiveness of biochar immobilization has not been widely studied. In this review, retrospective search was carried out on the published literature results concerning remediation effects of biochar on different areas of heavy metal contaminated soil in the recent years, its application in field remediation (several years), and some potential abiotic and biotic factors that may weaken the immobilization effects of biochar. This results indicate that: (1) biochar is widely used in the remediation of heavy metal contaminated soil in different areas and has excellent immobilization effect. (2) Most of the research demonstrate that the immobilization effect of biochar is effective for 2-3 years or according to few results even for 5 years. However, there have been various reports claiming that the immobilization effect of biochar decreases with time. (3) Abiotic factors such as acid rain, flooded environment, changes in soil condition (pH, redox and dissolved organic matter) and changes in biochar (Cl- and alkali leaching) can significantly weaken the immobilization effect of biochar. (4) Biotic factors such as plant roots, earthworms and soil microorganisms can also significantly reduce the immobilization effect of biochar. Therefore, field experiments having longer time span with biochar need to be further carried out, and the developmental research of modified biochar with a more stable immobilization effect also needs further attention.