Long-term effects of fine particulate matter components on depression among middle-aged and elderly adults in China: A nationwide cohort study.

BACKGROUND: Fine particulate matter (PM2.5) has been implicated in various health concerns. However, a comprehensive understanding of the specific PM2.5 components affecting depression remains limited. METHODS: This study conducted a Cox proportional-hazards model to assess the effect of PM2.5 components on the incidence of depression based on the China Health and Retirement Longitudinal Study (CHARLS). Participants with 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) score of 10 or higher were classified as exhibiting depression. RESULTS: Our findings demonstrated a significant positive correlation between long-term exposure to black carbon (BC), sulfate (SO42-), and organic matter (OM) components of PM2.5 and the prevalence of depression. Per 1 Interquartile Range (IQR) increment in 3-year average concentrations of BC, OM, and SO42- were associated with the hazard ratio (HR) of 1.54 (95 % confidence intervals (CI): 1.44, 1.64), 1.24 (95%CI: 1.16, 1.34) and 1.25 (95%CI: 1.16, 1.35). Notably, females, younger individuals, those with lower educational levels, urban residents, individuals who were single, widowed, or divorced, and those living in multi-story houses exhibited heightened vulnerability to the adverse effects of PM2.5 components on depression. LIMITATIONS: Firstly, pollutant data is confined to subjects' fixed addresses, overlooking travel and international residence history. Secondly, the analysis only incorporates five fine particulate components, leaving room for further investigation into the remaining fine particulate components in future studies. CONCLUSIONS: This study provides robust evidence supporting the detrimental impact of PM2.5 components on depression. The identification of specific vulnerable populations contributes to a deeper understanding of the underlying mechanisms involved in the relationship between PM2.5 components and depression.

Long-term effects of particulate matter on incident cardiovascular diseases in middle-aged and elder adults: The CHARLS cohort study.

BACKGROUND: Although there is evidence of long-term effects of particulate matter (PM) on cardiovascular diseases (CVD), researches about long-term effects of PM1 on CVD are limited. We aimed to examine the long-term effects and magnitude of PM, especially PM1, on incident CVD in China. METHODS: We included 6016 participants aged ≥ 45 years without CVD at baseline in 2011 from the China Health and Retirement Longitudinal Study. Personal PM (PM1, PM2.5, and PM10) concentrations were estimated using geocoded residential address. Generalized linear mixed models and SHapley Additive exPlanation were utilized to calculate the impacts and contributions of PM on CVD. Sensitivity analyses were used to check the robustness. RESULTS: After a follow up of 4-year, 481 (7.99 %) participants developed CVD. Per 10 µg/m3 uptick in 1-year average concentrations of PM1, PM2.5 and PM10 was associated with a 1.20 [95 % confidence interval (CI): 1.05-1.37], 1.13 (95 % CI: 1.11-1.15), and 1.10 (95 % CI: 1.06-1.13) fold risk of incident CVD, respectively. The 2-year average concentrations of PM1, PM2.5 and PM10 were associated with incident CVD, corresponding to a 1.03 (95 % CI: 0.96-1.10), 1.11 (95 % CI: 1.02-1.21), and 1.09 (95 % CI: 1.03-1.15) fold risk, respectively. The SHapley Additive exPlanation values of PM1, PM2.5, and PM10 were 0.170, 0.153, and 0.053, respectively, corresponding to the first, second, and fifth among all air pollutants. Effects of PM1, PM2.5 and PM10 on CVD remained statistically significant in two-pollutant models. The elderly, males, smokers and alcohol drinkers tended to have slightly higher effects, while the differences were not statistically significant (all P-values > 0.05) between subgroups. CONCLUSION: Long-term exposure to PM1, PM2.5, and PM10 was associated with an increased incidence of CVD. The smaller the particle size, the more important it was for incident CVD indicating that emphasis should be placed on small size of PM.

Long-term effect of intermediate particulate matter (PM1-2.5) on incident asthma among middle-aged and elderly adults: A national population-based longitudinal study.

BACKGROUND: There is insufficient evidence about the long-term effects of intermediate particulate matter (PM1-2.5) on asthma development in adults aged 45 years and above. This study aimed to investigate the relationship between long-term exposure to PM1-2.5 and the incidence of asthma in adults aged 45 years and above. METHODS: A cohort study based on the China Health and Retirement Longitudinal Study (CHARLS) database was conducted to investigate the long-term effects of PM1-2.5 on self-reported asthma incidence in adults aged 45 years and above in China from 2011 to 2018. The PM concentrations were estimated using a high-resolution (1 km2) satellite-based spatiotemporal model. A covariate-adjusted generalized linear mixed model was used to analyze the relationship between long-term exposure to PM1-2.5 and the incidence of asthma. Effect modifications and sensitivity analysis were conducted. RESULTS: After a 7-year follow-up, 103 (1.61 %) of the 6400 participants developed asthma. Each 10 µg/m3 increment in the 1-, 2-, 3-, and 4-year moving average concentrations of PM1-2.5 corresponded to a 1.82 [95 % confidence interval (CI):1.11-2.98], 1.95 (95 % CI: 1.24-3.07), 1.95 (95 % CI: 1.26-3.03) and 1.88 (95 % CI: 1.26-2.81) fold risk for incident asthma, respectively. A significant multiplicative interaction was observed between socioeconomic level and long-term exposure to PM1-2.5. Stratified analysis showed that smokers and those with lower socioeconomic levels were at higher risk of incident asthma related to PM1-2.5. Restricted cubic splines showed an increasing trend in asthma incidence with increasing PM1-2.5. Sensitivity analyses showed that our model was robust. CONCLUSION: Long-term exposure to PM1-2.5 was positively associated with incident asthma in middle-aged and elderly individuals. Participants with a history of smoking and lower socioeconomic levels had a higher risk. More studies are warranted warrant to establish an accurate reference value of PM1-2.5 to mitigate the growing asthma burden.

Lightweight and broadband 2D MoS2 nanosheets/3D carbon nanofibers hybrid aerogel for high-efficiency microwave absorption.

Three-dimensional (3D) porous molybdenum disulfide nanosheets/carbon nanofibers (MoS2/CNF) hybrid aerogels were synthesized by using solvothermal method and following carbonization, where two-dimensional (2D) MoS2 nanosheets were homogenously in-situ grown on the interconnected CNF skeleton derived from bacterial cellulose, forming a hierarchical porous structure. This unique heterogeneous structure of the MoS2/CNF hybrid aerogels were conducive to electromagnetic loss, including conduction, polarization, multi-scatterings, and reflections, thus resulting in a balanced impedance matching and microwave attenuation capacity. It was found that the resulted MoS2/CNF hybrid aerogels demonstrate excellent microwave absorbing performance when the only 5.0 wt% fillers were loaded in paraffin. Particularly, MoS2/CNF-2-900 hybrid aerogel displayed an effective absorption bandwidth of 5.68 GHz and minimum reflection loss (RLmin) value of -36.19 dB at a thickness of 2.0 mm. As the thickness increases to 4.4 mm, the RLmin value of MoS2/CNF-2-900 hybrid aerogel reaches -48.53 dB. Electromagnetic loss mechanism analysis indicates that such improved microwave attenuation is attributed to proper component, multiple heterogenous interface and hierarchical porous structures. All the results in this work pave the avenue for the development of ultralight microwave absorber with high absorption capacity as well as broad effective absorption bandwidth.

Value of micro-CT for monitoring spinal microvascular changes after chronic spinal cord compression.

Neurological degeneration can occur after compression of the spinal cord. It is widely accepted that spinal cord compression leads to ischemic lesions and ultimately neurological dysfunction due to a narrowed spinal canal. Therefore, an in-depth understanding of the pathogenesis of spinal cord compression injury is required to help develop effective clinical interventions. In the present study, we propose a new method of quantitative 3D micro-CT to observe microvascular events in a chronic spinal cord compression rat model. A total of 36 rats were divided into two groups: sham control group (n = 12) and compressive spinal cord injury group (n = 24). Rats were scarified at four weeks after surgery. In each group, CD34 micro-vessel immunohistochemical staining was performed in half of the animals, while micro-CT scanning was performed in the other half. Microvessel density (MVD) was measured after immunohistochemical staining, while the vascular index (VI) was measured in 3D micro-CT. In comparison with sham control, abnormal somatosensory evoked potentials (SEP) can be seen in all 24 cases of the compression group, and VI shows the amount of microvessels reduced consistently and significantly (p < 0.01). A significant correlation is also found between MVD and VI (r = 0.95, p < 0.01). These data suggest that quantitative 3D micro-CT is a sensitive and promising tool for investigating microvascular changes during chronic compressive spinal cord injury.

Is the speed of chronic compression an important factor for chronic spinal cord injury rat model?

OBJECTIVE: To evaluate the effect of expansion speed on chronic compressive spinal cord injury in the rat. METHODS: Thirty-six Sprague-Dawley rats were divided into four groups: a control group, a group receiving compressor in the C5-C6 epidural space with instant compression (group 1), and two other groups receiving water-absorbing polyurethane polymer sheets with two expansion speeds, which reached maximum volume in 2 h (group 2: fast expansion) or 24 h (group 3: slow expansion). A C6 laminectomy was performed in the control group. Neurological function, MRI, large motoneuron number in the ventral horn, and myelin staining intensity in the posterior funiculus were evaluated. RESULTS: In the instant compression group, compression was confirmed on T2-weighted images by a hypointense signal change in the intramedulla. In the gradual compressive injury groups, large motoneuron number (p<0.001), but not myelin staining intensity, was significantly decreased in both the fast and slow expansion groups compared with the instant compression group. However, there was no difference in Basso Beattie Bresnahan score, cord distortion in T2-weighted image, large motoneuron numbers, or myelin staining between the fast and slow expansion groups. CONCLUSION: Instant spinal cord compression caused acute injury. Gradual expansion compression induced reliable pathology and MRI characteristics consistent with chronic compressive spinal cord injury. The speed of expansion is not a significant problem for establishing a reliable model if the chronic compression is induced by gradual expansion.

HIF-1α/VEGF signaling pathway may play a dual role in secondary pathogenesis of cervical myelopathy.

Cervical spondylotic myelopathy (CSM) is one of the most common spinal cord disorders affecting the elderly. Yet the exact pathophysiology of CSM remains unclear. Vascular response to initial mechanical compression and associated ischemia may involve in secondary pathophysiology. Chronic compressive lesions to cervical cord resulting in lack of perfusion have established considerable evidences to support ischemia as an important pathogenesis both in patients and animal models, a similarity as that of acute spinal cord injury (SCI). In hypoxic condition following SCI, the up-regulation of vascular endothelial growth factor (VEGF), is consistent with increasing hypoxia induced factor-1α (HIF-1α) in acute periods. HIF-1α/VEGF signaling pathway is thought to play a dual role following SCI. In one hand, VEGF was demonstrated to be correlated with angiogenesis (protecting vascular endothelial cells, increasing blood vessel density and improving regional blood flow), neurogenesis (antiapoptotic, neurotrophic, attenuate axonal degradation), and locomotor ability improvement. In other hand, some studies revealed that VEGF have limited therapeutic effect, even exacerbate the secondary damage following SCI. VEGF administrations in acute or subacute periods result in elevation of blood-spinal cord barrier (BSCB) permeability even last for chronic course. BSCB permeability elevation initiates a secondary cascade of events involving excitotoxicity, infiltration of leukocytes and tissue edema. With comprehensive understanding of temporal and spatial of HIF-1α/VEGF signaling pathway, development of therapeutic strategies to promote new vessel growth while minimize the deleterious effects of VEGF-induced microvascular permeability, and thereby improve neurologic function, seems to be feasible and promising.