Climate change poses a significant threat to public health. Existing studies on the health impacts of climate change focus primarily on chronic and infectious diseases, with limited research on injury. To address this gap, this issue launched a special column titled "Climate change and injuries". Through interdisciplinary integration of atmospheric science and public health, we explored the impact of climate change on injury risk and burden from diverse perspectives. This initiative aims to deepen a comprehensive understanding of the impact of climate change on human health, enhance China's capacity to address climate-related health risks, reduce associated disease burden, and provide scientific evidence for targeted adaptation measures.

Background Previous studies found that high temperature and heatwave increase the risk of traffic injuries. The complex road conditions in Yunnan Province result in frequent traffic accidents. However, there is limited evidence on the correlation between heatwave and traffic injuries in Yunnan Province. Objective To assess the association between heatwave events and traffic injuries, to estimate its disease burden, and to identify relevant sensitive groups. Methods We collected data on traffic injury cases and concurrent meteorological information from four surveillance sites in Yunnan Province, China: Dali, Lufeng, Zhaoyang, and Qilin from May to September each year from 2015 to 2023. Traffic injury cases refer to patients who visited the outpatient or emergency departments of local surveillance hospitals for the first time due to traffic injuries. Meteorological data were derived from the fifth generation atmosphericreanalysis dataset of the global climate provided by the European Centre for Medium-Range Weather Forecasts. A time-stratified case-crossover design combined with distributed lag non-linear model was used to analyze the association between short-term exposure to heatwave and traffic injuries. We also conducted subgroup analyses by sex, age, occupation, injury cause, activity at the time of injury occurrence, and severity of injury. Results A total of 34764 traffic injury surveillance cases were included in the analysis. The risk of traffic injuries occurred during heatwave was 1.13 times (95%CI: 1.07, 1.20) greater than those occurred during non-heatwave, and 2.64% (95%CI: 1.49%, 3.73%) of traffic injuries were attributed to heatwave exposure throughout the study period. The results of stratified analysis showed greater impacts of heatwave on the risk of traffic injuries in female [odds ratio (OR)=1.17, attributable fraction (AF)=3.23%], people aged 15-64 years (OR=1.13, AF=2.68%), farmers/workers (OR=1.22, AF=4.07%), people with non-motor vehicle traffic injuries (OR=1.17, AF=3.24%), people who were driving or riding when injuries occurred (OR=1.12, AF=2.43%), and people with minor injuries (OR=1.18, AF=3.49%) ( P<0.05). Longer duration [excess risk (ER)=0.99%] and greater intensity (ER=4.12%) of heatwave had greater impacts on the risk of traffic injuries (P<0.05). Conclusion Heatwave events are associated with an increased risk of traffic injuries. Female, people aged 15-64, farmers/workers, people with non-motor vehicle traffic injuries, those injured while driving/riding a vehicle, and people with minor injuries are particularly vulnerable. The findings suggest that targeted mitigation and adaptation measures should be taken to address the risk of traffic injuries associated with extreme climate events.

Background Injury poses a serious threat to human health. As global warming continues to intensify, there is an urgent need to explore the impact of temperature changes on injury deaths. However limited research has focused on this issue. Objective To investigate the relationship between daily mean temperature change (Tm) and injury death, as well as to estimate the associated future death burden in Hunan Province. Methods We employed an individual-level, time-stratified case-crossing design to establish a conditional logistic regression model to analyze the exposure-response relationship between daily mean temperature change and injury death in Hunan Province from 2013 to 2018. Consequently, we conducted subgroup analysis of gender, age group, and injury type. Finally, we estimated the excess burden of injury death attributable to temperature changes under a sustainable development path [low emission scenario (SSP1-2.6)], regional competition path [high emission scenario (SSP3-7.0)], or fossil fuel development path [very high emission scenario (SSP5-8.5)]. Results The study collected 155577 injury deaths in Hunan Province. The results indicated that for each 1 ℃ increment in daily mean temperature, the cumulative excess risk (CER) of injury mortality among Hunan residents increased by 0.71% (95%CI: 0.53%, 0.90%). Notably, the CER for intentional injuries (1.06%, 95%CI: 0.51%, 1.61%) was higher than that for unintentional injuries (0.66%, 95%CI: 0.46%, 0.87%). Warmer temperatures were positively associated with CER of mortality due to drowning, falls, transport injuries, assaults, and suicides, while they were negatively associated with mortality due to poisoning. Compared with 2010–2019, for 2090–2099, the excess mortality rate (EMR) due to ambient temperature increase in Hunan Province under the SSP5-8.5 scenario (14.62/100000, 95%CI: 10.81/100000, 18.40/100000) would be higher than that of the SSP3-7.0 scenario (10.28/100000, 95%CI: 7.58/100000, 12.97/100000) and the SSP1-2.6 scenario (3.35/100000, 95%CI: 2.46/100000, 4.23/100000); the EMR would be around 2.5 times among men (20.64/100000, 95%CI: 14.44/100000, 26.8/100000) than that among women (8.33/100000, 95%CI: 3.98/100000, 12.6/100000). Among unintentional injuries, the leading contributors to EMR would be drowning (4.46/100000), falls (3.96/100000), and transport injuries (2.96/100000). And among intentional injuries, the EMR for suicide (2.08/100000) would be higher than that for assault (0.47/100000). Conclusion Climate warming will increase the total burden of injury-related deaths among residents in Hunan Province, especially in the absence of effective mitigation strategies and measures. It is necessary to strengthen the prevention and control of severe injuries closely related to temperature changes, such as drowning, falls, traffic, and suicides injuries, in order to reduce injury deaths associated with climate change.

Background Under the background of global warming, research on association between ambient temperature and risk of injury is needed. Objective To examine the effect of temperature on injury in Bao'an district, Shenzhen and identify the sensitive population, thereby providing a scientific basis for formulating prevention and control strategies and measures of injury. Methods The injury reports from the Injury Surveillance System and the meteorological data of Bao'an District between 2018 to 2022 were collected. The meteorological data were sourced from the fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) land reanalysis data. Based on time-stratified case-crossover design, conditional logistic regression combined with distributed lag nonlinear model was used to evaluate the exposure-response association between ambient temperature and injury. The stratified analyses were further conducted by gender, age, and causes of injury. Results A total of 156205 injury cases were collected from the injury surveillance sentinel hospitals in Bao'an District of Shenzhen from 2018 to 2022, and the median of daily average temperature during the same period was 20.0 ℃. The exposure-response curve showed that the risk of injury was positively correlated with temperature. The linearized analysis revealed that each 1°C increase in temperature was associated with a 1.05% (95%CI: 0.68%, 1.42%) rise in injury risk (ER). Notably, the effect was greater in females (ER=1.31%, 95%CI: 0.67%, 1.94%) than males (ER=0.92%, 95%CI: 0.47%, 1.37%). Among age groups, adults ＞60 years faced the highest risk (ER=1.91%, 95%CI: −0.36%, 4.24%). The top three temperature-associated injury risks were sharp instrument injuries (ER=2.19%, 95%CI: 1.16%, 3.22%), animal injuries (ER=1.71%, 95%CI: 0.86%, 2.56%), and blunt injuries (ER=071%, 95%CI: −0.08%, 1.51%). The impact of temperature on unintentional injuries (ER=1.11%, 95%CI: 0.72%, 1.49%) was higher than that on intentional injuries (ER=0.43%, 95%CI: −0.85%, 1.72%). Severe injuries (ER=2.20%, 95%CI: −3.09%, 7.77%) were more affected by temperature than mild injuries (ER=1.00%, 95%CI: 0.58%, 1.43%) and moderate injuries (ER=1.15%, 95%CI: 0.42%, 1.89%). Conclusion The increase in ambient temperature associates with injury occurrence, and the impact of temperature exhibits obvious heterogeneity among different populations, indicating that targeted intervention measures should be taken for different populations and types of injuries.

Objective:To investigate the activation of ubiquitin proteasome system (UPS) and autophagy in brain tissues of rats after severe traumatic brain injury (sTBI) and the role of autophagy in secondary traumatic brain injury.Methods:(1) Twenty-five SD rats were randomly divided into sham-operated group, group of 3 h after sTBI, group of 1 d after sTBI, group of 3 d after sTBI and group of 7 d after sTBI ( n=5). Only bone window was opened in sham-operated group, and controlled cortical impact (CCI)-induced sTBI models were established in the other 4 groups. Western blotting was used to detect the expressions of free ubiquitin, ubiquitinated protein, vacuolar protein sorting 34 (VPS34), P62, microtubule-associated protein-light chain 3-II, and Mature-cathepsin D (CTSD). (2) One hundred SD rats were randomly divided into normal control group, sTBI group, lactacystin group and SAR405 group ( n=25). Ten μL lactacystin or SAR405 were stereotactically injected into the lateral ventricle of lactacystin group and SAR405 group, respectively; 30 min after that, CCI-induced sTBI models were established in the sTBI group, lactacystin group and SAR405 group. Three d after modeling, the expressions of ubiquitinated protein, LC3-II, P62, and Caspase-3 were detected by Western blotting; percentage of brain water content was determined by dry/wet weight ratio; neurological functions were assessed by modified neurological deficit scale (mNSS); degrees of brain tissue damage were detected by HE staining; and cerebral blood perfusion was detected by laser scattering hemodynamic imaging system. Results:(1) Compared with sham-operated group, group of 3 h after sTBI, group of 1 d after sTBI, group of 3 d after sTBI and group of 7 d after sTBI had significantly decreased free ubiquitin, and group of 1 d after sTBI, group of 3 d after sTBI and group of 7 d after sTBI had significantly increased ubiquitinated protein in the brain tissues surrounding the injury lesions ( P<0.05). Compared with sham-operated group, group of 3 d after sTBI and group of 7 d after sTBI had statistically increased VPS34 and Mature-CTSD and significantly decreased P62 and group of 1 d after sTBI, group of 3 d after sTBI and group of 7 d after sTBI had significantly increased LC3-II in the brain tissues surrounding the injury lesions ( P<0.05). (2) The ubiquitinated protein relative expressions in the brain tissues surrounding the injury lesions of normal control group, sTBI group, lactacystin group and SAR405 group were 4.78±2.63, 10.62±0.73, 13.45±1.22 and 8.50±0.83, respectively, with significant differences ( P<0.05). Compared with the normal control group, the sTBI group, lactacystin group and SAR405 group had significantly higher LC3-II, ubiquitinated protein and cleaved caspase-3/pro-caspase-3, and significantly lower P62 in the brain tissues surrounding the injury lesions ( P<0.05); compared with the the sTBI group, the lactacystin group had significantly higher LC3-II, ubiquitinated protein, and cleaved caspase-3/pro-caspase-3, and significantly lower P62 in the brain tissues surrounding the injury lesions ( P<0.05); compared with the the sTBI group, the SAR405 group had significantly lower LC3-II, ubiquitinated protein and cleaved caspase-3/pro-caspase-3, and significantly higher P62 in the brain tissues surrounding the injury lesions ( P<0.05). Compared with the normal control group([67.60±2.51]%、[0±0] scores、[333.41±46.86] PU), the sTBI group, lactacystin group and SAR405 group had statistically higher percentage of brain water content and mNSS scores ([80.2±1.30]%, [87.0±1.58]% and [71.60±1.81]%; 13.8±1.10, 16.4±0.55 and 10.40±1.14) and signficantly lower cerebral blood perfusion volume ([53.98±5.99] PU, [21.71±2.62] PU and [87.97±6.75] PU, P<0.05); compared with the sTBI group, the lactacystin group had significantly higher brain water content and mNSS scores, and significantly lower cerebral blood perfusion volume ( P<0.05); compared with the sTBI group, the SAR405 group had significantly lower brain water content and mNSS scores, and significantly higher cerebral blood perfusion volume ( P<0.05). HE staining showed that the cortical tissues were most severely damaged in the lactacystin group, followed by the sTBI group; the least damage was noted in the SAR405 group, and no significant damage in the normal control group was noted. Conclusion:After sTBI, UPS activation is earlier than autophagy; autophagy inhibition helps to alleviate UPS dysfunction, reduce Caspase-3-induced apoptosis, and is beneficial to the recovery of neurological function.

Objective:To optimize the diagnosis-related groups (DRG) weight calculation method based on the perspective of hospital performance evaluation and the high-quality development orientation of public hospitals.Methods:Using the first page data of 3 256 701 inpatient medical records from secondary and tertiary hospitals in Beijing from January to December 2021, three algorithms including payment DRG weight, five-category DRG weight, and optimized DRG weight were used to calculate the weights of each DRG, and the differences between different algorithms were analyzed. The case-mix index (CMI) of the entire hospital and the clinical specialties to which the key DRG belongs in secondary and tertiary hospitals was calculated by using the three DRG weight algorithms, to reflect the performance evaluation results of different algorithms.Results:The results of one-way ANOVA showed that there was a significant difference ( P=0.019) among the three DRG weight algorithms. Comparing the optimized DRG weight with the payment DRG weight, the weight of BD29 (neural stimulator implantation or removal surgery) in the key DRG decreased from 7.77 to 4.61, and the weight of LA19 (renal tumor surgery) increased from 2.06 to 2.58; Compared with the five-category DRG weight, the weight of ES31 (respiratory infection/inflammation with severe complications or comorbidities) decreased from 2.36 to 1.72, and the weight of CB39 (crystalloid surgery) increased from 0.22 to 0.30. Comparing the use of optimized DRG weights and five-category DRG weights to calculate CMI, all types of hospitals and clinical specialties showed varying degrees of improvement in CMI. The CMI of tertiary hospitals increased from 1.02 to 1.20, and the CMI of secondary hospitals increased from 0.88 to 0.95. The difference in CMI between secondary and tertiary hospitals was even more pronounced. Conclusions:Optimized DRG weights could better reflect the value of medical technology compared with the payment DRG weights. Compared to five-category DRG weights, optimized DRG weights could better reflect the differences in CMI of different levels of hospitals.

Osteoporosis is an emerging threat characterized by systemic damage to bone mass and microarchitecture leading to fragility fractures.Exosomes are nanosized vesicular particles secreted by cells into the extracellular compartment with biological activities similar to those of their cell of origin and play an important role in intercellular communication processes.Exosomes from multiple cell sources are involved in the regulation of bone-related cell proliferation and differentiation during bone metabolism,and have the advantages of high stability,non-immunogenicity and strong targeting ability,which make up for the shortcomings of traditional drug and stem cell therapies.Exosomes secreted from bone marrow mesenchymal stem cells(MSCs)can promote bone regeneration and improve morphology,biomechanics and histological damage,and exosomes derived from bone marrow mesenchymal stem cells(BMSCs)in the mechanical microenvironment are more effective in inducing osteogenesis,significantly enhancing the osteogenic effect of BMSCs and promoting bone regeneration.Therefore,this article provides a review on the mechano-sensitivity of MSCs,mechanical responsive functionalized exosomes of MSCs,and explores their potential role in the treatment of osteoporosis.

Climate change has led to an increasing frequency and intensity of extreme climate events such as heat and drought extremes with considerable global public health burden. This systematic review collected 87 domestic and international studies from 2000 to 2023, considering the impacts of heat extremes, drought extremes, and compound hot-dry events on infectious diseases attributable to various transmission pathways such as waterborne, foodborne, insect-borne, airborne, and contact-transmitted diseases. Our results showed that high temperature was associated with increased transmission risks of waterborne and foodborne diseases including infectious diarrheal diseases (cholera, dysentery, typhoid, and paratyphoid) and infectious gastroenteritis; vector-borne diseases including dengue fever, Zika virus (ZIKV) disease, chikungunya fever, malaria, West Nile fever, and Rift Valley fever; airborne diseases including influenza-like diseases, influenza A, measles, and mumps; and contact-transmitted diseases including HIV/AIDS, schistosomiasis, and leptospirosis. Additionally, drought conditions also amplified the transmission risks of waterborne and foodborne diseases including cholera, Escherichia coli infection, rotavirus infection, and hepatitis E; vector-borne diseases such as scrub typhus, schistosomiasis, hemorrhagic fever with renal syndrome, and West Nile fever; airborne diseases including meningococcal meningitis, pertussis, measles, and upper respiratory infections; and contact-transmitted diseases such as HIV/AIDS. Along with global warming, the frequency of compound high temperature and drought events shows a considerably increasing trend, causing more adverse health effects than heat or drought alone. However, there is limited research quantifying their effects on infectious diseases. These associations may be mediated through temperature and precipitation on infectious disease pathogens, transmission vectors, population susceptibility, public health services, and behaviors. In the context of climate change, the increasing occurrence of compound events of high temperatures and droughts raises health concerns, and further studies are needed to enhance our understanding of the impacts of climate change on infectious diseases and improve human adaption to climate change.

Objective:To explore the optimal index of rotational displacement of femoral neck fractures by modeling the axial rotational displacement of femoral neck fractures after reduction and based on X-ray projections.Methods:Six dry human femur specimens, comprising 2 males and 4 females, were utilized in the study. Design and manufacture a proximal femur ortholateral and oblique X-ray casting jigs and mounts. The femoral neck fracture was modeled on the femoral specimen, with Pauwells 30°, 50°, and 70° models (2 each) made according to Pauwells typing. The fractures were manually repositioned with residual anterior 20°, 40° and 60° axial rotational displacements. Each fracture model was projected at different angles (pedicled 40°, pedicled 20°, vertical 0°, cephalad 20°, and cephalad 40°), and the trabecular angle and Garden's alignment index of the model were measured to observe the imaging characteristics of the fracture line on the medial oblique and lateral oblique radiographs.Results:In the presence of a 20° and 40° anterior rotational displacement following reduction of a femoral neck fracture, the trabecular angle in the rotationally displaced group was not significantly different from that of the anatomically repositioned group in various projection positions. However, when a residual rotational displacement of 60° was present, the trabeculae appeared blurred at most projection angles in the Pauwells 30° and 50° models, failing to measure trabecular angles. In the Pauwells 70° fracture model, the trabecular angle in the rotational displacement group was significantly different from that in the anatomical reduction group. In anteroposterior radiographs, when the anterior rotation displacement was 60° in the Pauwells 70° group, Garden's contralateral index showed an unsatisfactory restoration (150°, 142°), whereas all rotationally displaced models in the Pauwells 30° and Pauwells 50° groups had a Garden's contralateral index of >155°, which achieved an acceptable restoration. In lateral radiographs, all rotational displacement models with Garden's alignment index>180° failed to achieve acceptable repositioning, and the larger the Pauwells angle the greater the Garden's alignment index at the same rotational displacement. In the internal oblique position with a bias towards the foot side, the image showed partial overlap between the femoral head and the shaft, making it difficult to assess the quality of the reduction. Conversely, when projected cephalad, the femoral neck appeared longer, particularly at a projection angle of 40° cephalad, allowing for clear observation of the fracture line and the anatomy of the proximal femur. The trabeculae were not well visualized in the external oblique position.Conclusion:There are limitations in applying the trabecular angle to assess the axial rotational displacement of the femoral head after reduction of femoral neck fractures. The Pauwells 70° with residual rotational anterior displacement of 60° was the only way to detect axial rotational displacement of the femoral head on anteroposterior radiographs Garden's alignment index. For the determination of axial rotational displacement of the femoral head, the Garden's alignment index on lateral radiographs provides higher reliability.

Examining mechanisms involved in the mutual regulation between the muscular system and the skeletal system, elucidating the key issues responsible for loss of muscle and bone mass and strength, and thus halting the progression of these conditions are critical measures for reducing fractures caused by falls and subsequent disability and mortality.At present, most studies have treated the muscular system and the skeletal system separately, often ignoring the mutual regulation and connections between them.This article reviews the current research progress on the mechanisms of interaction between the two systems, aiming to provide a basis for the prevention, diagnosis and treatment of disuse-related diseases in the elderly population.