Influencing factors associated with high myopia in Chinese college students.

Background: High myopia (HM) may elicit irreversible pathological changes in the fundus and severely impair visual quality, thereby becoming a major public health issue in China. However, the influencing factors associated with HM remain unknown in Chinese college students, whose visual quality is crucial to country development. Methods: This is a cross-sectional observational study. Two thousand three hundred and fifteen undergraduate and graduate students were initially recruited from various majors in 3 universities in Tianjin, China. Under the principle of voluntary participation and informed consent, simple random sampling was conducted in the recruited subjects while maintaining balanced number of subjects from each major. After screening with inclusion and exclusion criteria, 96 undergraduate and graduate students (186 eyes) were finally included and divided into non-HM and HM groups. The eyes of subjects were examined by optical coherence tomography angiography (OCTA) for vessel density and structure thickness at the macula and optic disc, and the subjects were surveyed by an itemized questionnaire on lifestyles and study habits. Results: The OCTA and questionnaire results revealed 10 factors, including hemodynamic and anatomic parameters and lifestyle metrics, with statistical significance between the non-HM and HM groups. Receiver operating characteristic curve analysis showed that vessel density of the inner retina at the macula, vessel density of the radial peripapillary capillary at the optic disc, smartphone usage time, continuous near work time, and sleeping after midnight had superior values of area under the curve (AUC > 0.700). Therefore, these 5 factors were selected for univariant and multivariant logistic regression analyses. A prediction model comprising the 5 influencing factors had an AUC of 0.940 and 95% CI of 0.908-0.972. Conclusion: This study for the first time identified the vessel density of the inner retina at the macula, the vessel density of the radial peripapillary capillary at the optic disc, smartphone usage time, continuous near work time, and sleeping after midnight as influencing factors associated with HM in Chinese college students. A prediction model comprising the 5 influencing factors was proposed for calculating likelihood of a Chinese college student developing HM, based on which lifestyle improvement and medical intervention might be recommended.

Assessment of PM2.5-related health effects: A comparative study using multiple methods and multi-source data in China.

In China, PM2.5 pollution has caused extensive death and economic loss. Thus, an accurate assessment of the spatial distribution of these losses is crucial for delineating priority areas for air pollution control in China. In this study, we assessed the PM2.5 exposure-related health effects according to the integrated exposure risk function and non-linear power law (NLP) function in 338 prefecture-level cities in China by utilizing online monitoring data and the PM2.5 Hindcast Database (PHD). Our results revealed no significant difference between the monitoring data and PHD (p value = 0.66 > 0.05). The number of deaths caused by PM2.5-related Stroke (cerebrovascular disease), ischemic heart disease, chronic obstructive pulmonary disease, and lung cancer at the national level estimated through the NLP function was 0.27 million (95% CI: 0.06-0.50), 0.23 million (95% CI: 0.08-0.38), 0.31 million (95% CI: 0.04-0.57), and 0.31 million (95% CI: 0.16-0.40), respectively. The total economic cost at the national level in 2016 was approximately US$80.25 billion (95% CI: 24.46-132.25). Based on a comparison of Z statistics, we propose that the evaluation results obtained using the NLP function and monitoring data are accurate. Additionally, according to scenario simulations, Beijing, Chongqing, Tianjin, and other cities should be priority areas for PM2.5 pollution control to achieve considerable health benefits. Our statistics can help improve the accuracy of PM2.5-related health effect assessments in China.

[Analysis on application value of Fu's subcutaneous needling for intercostal pain after surgery of osteoporotic thoracic vertebral compression fracture].

OBJECTIVE: To observe the effect of Fu's subcutaneous needling therapy on pain degree, quality of life, serum 5-hydroxytryptamine (5-HT) and neuropeptide Y (NPY) in patients with intercostal pain after surgery for osteoporotic thoracic vertebral compression fracture (OVCF) and explore the application value of Fu's subcutaneous needling in treatment of post-operative intercostal pain. METHODS: A total of 60 patients with intercostal pain after OVCF surgery were divided into a medication group and a Fu's subcutaneous needling therapy group, with 30 cases in each group. In the medication group, zoledronic acid injection, salmon calcitonin injection, calcitonin D tablets and mecobalamin tablets were prescribed. The duration of treatment was 8 weeks. In the Fu's subcutaneous needling therapy group, on the base of treatment as the medicine group, Fu's subcutaneous needling therapy was provided for 2 weeks，once every other day. The needle is inserted 6 cm away from the most painful point. Separately, in 2, 4 and 8 weeks of treatment, as well as in 16 weeks after treatment, the visual analogue scale (VAS) and the generic quality of life inventory-74 (GQOLI-74) were adopted to evaluate intercostal pain and quality of life in the patients of both groups and analyze the incidence of adverse reaction. Radioimmunoassay was used to measure the levels of serum 5-HT and NPY. RESULTS: Compared with the results before treatment, in 2, 4 and 8 weeks of treatment as well as in 16 weeks after treatment, VAS scores of both groups were all reduced (P<0.05), GQOLI-74 scores increased obviously (P<0.05) and the levels of serum 5-HT and NPY increased obviously (P<0.05) in the two groups. In 2, 4 and 8 weeks of treatment as well as in 16 weeks after treatment, VAS score in the Fu's subcutaneous needling therapy group was lower than that in the medication group (P<0.05), GQOLI-74 score and the levels of serum 5-HT and NPY were higher than those in the medication group (P<0.05). During the treatment and in 16 weeks after treatment, the difference was not significant in the incidence of adverse reaction between the two groups (P>0.05). CONCLUSION: Fu's subcutaneous needling therapy can relieve intercostal pain and improves the quality of life in the patients after surgery for OVCF.

Air pollution and cause-specific mortality: A comparative study of urban and rural areas in China.

Air pollution increases the risks of all-cause mortality, cardiovascular mortality and respiratory mortality across China. However, the urban-rural differences in the associations between air pollution and mortality have not been clearly identified. In this study, a distributed lag nonlinear model was used to examine whether the air pollutants-mortality associations vary between urban and rural areas. Then, we used logistic regression analyses to evaluate the air pollutants-mortality relations. Also, generalized additive models were simulated to evaluate the nonlinear curves. Our results showed that the relative risks of air pollution-related mortality were generally higher in rural areas, where PM2.5 pollution was the dominant factor (p-value < 0.05). Mortality risks for all-cause, cardiovascular and respiratory will increase when average annual PM2.5 concentrations exceed approximately 38 µg/m3, 41 µg/m3 and 41 µg/m3, respectively, all of which exceed the annual Grade II standards. In urban areas, PM10-2.5 and NO2 were associated with mortality (p-value < 0.05). We proposed some area-specific strategies for controlling the NO2 pollution and PM10-2.5 pollution in urban areas and the PM2.5 pollution in rural areas to eliminate the gaps. Our findings identify that rural residents are more sensitive to air pollution than urban residents in China, and this result challenges previous assumptions about the more adverse effects of urbanization on residents' health in developing countries.

Assessing NO2-related health effects by non-linear and linear methods on a national level.

Exposure to NO2 pollution has a significant adverse effect on residents' health. However, few studies have assessed the health effects associated with NO2 pollution. Compared with PM2.5 pollution, the harmfulness of NO2 pollution has not been quantitatively studied or clearly identified. In this study, we assessed the NO2 exposure-related health effects by non-linear and linear methods, taking advantage of online monitoring and survey data. We also assessed the economic cost of NO2 pollution in 338 cities in China. Our results showed that the average annual concentration of NO2 in the top fifteen cities with more than ten million permanent residents (except for Shenzhen, in the Guangdong province) exceeded the annual Grade II standards (40 µg/m3). The estimated national NO2-related all-cause mortality for non-linear and linear methods were 388.5 × 103 (95% CI: 198.1 × 103-748.2 × 103) and 374.1 × 103 (95% CI: 194.3 × 103-695.9 × 103), respectively. The total calculated national economic cost was about 28.8 billion US$ (95% CI: 14.7-55.4) in 2016. In addition, the comparison results showed that the harm caused by PM2.5 pollution was about four times that of NO2 pollution. Our statistics contribute to the limited research on NO2 pollution's effects on health and the economy in China.

The alpine meadow around the mining areas on the Qinghai-Tibetan Plateau will degenerate as a result of the change of dominant species under the disturbance of open-pit mining.

Mining is well-known as one of the most aggressive human disturbances leading to massive and irreversible damages to natural ecosystems. However, the influence mechanisms of open-pit mining on plant communities and soil properties of alpine meadow on the Qinghai-Tibetan plateau are not well understood. In this study, we used structural equation modeling (SEM) to study the influence mechanisms in the disturbed areas of the Qulong copper mine. Our results revealed that the soil parameters of alpine meadow have been significantly changed by mining activities. SEM results showed that Plantago depressa Willd. was more suitable for growing in current soil conditions due to its tolerance to heavy metals than other dominant species, which meant that it would substitute the current two dominant species (Kobresia myosuroides (Villars) Fiori and Blysmus sinocompressus Tang et Wang) in the future and become the most important dominant species in the study area. Unfortunately, the Shannon-Wiener index, Alatalo evenness index and M-Gordon stability index are relatively low in the plot with Plantago depressa Willd. as the dominant species. In a word, the fragile alpine meadow ecosystem may degenerate in the future due to plants and soil disturbed by mining activities. Further, eight targeted recommendations were proposed to protect alpine meadow on the Qinghai-Tibetan plateau.

Identifying the contributions of multiple driving forces to PM10-2.5 pollution in urban areas in China.

Economic development and urban expansion have accelerated particulate matter pollution in urban areas in China. Particulate matter-driven haze poses a serious threat to human beings from a public health point of view. Substantial evidences had linked adverse health effects with exposures to PM2.5, but recent research indicated that PM10-2.5 also had great risk. However, the relative contributions of driving forces to PM10-2.5 pollution are not well understood in the urban areas in China, and no targeted policies have been regulated to control the pollution. In this study, we quantified the contributions of potential driving factor across China with the structural equation model (SEM). Our results showed that in 2015 and 2016, the annual average concentrations of PM10-2.5 in the 290 prefecture-level cities with a mean value of 36 and 35 µg/m3, respectively. Industrial scale contributed more to PM10-2.5 pollution than city size and residents' activities in urban areas based on SEM results. Driving forces included in our model could explain 42% of variations in PM10-2.5 pollution, which indicated that there existed influences from other anthropogenic sources and natural sources. Eleven targeted recommendations were then proposed to control PM10-2.5 pollution based on our mechanism analysis. Findings from our study are beneficial to control PM10-2.5 pollution on a national scale, and also can provide a theoretical basis for the formulation of PM10-2.5 pollution control policy in China.

Quantification and driving force analysis of ecosystem services supply, demand and balance in China.

Spatially quantifying ecosystem services (ES) supply, demand and balance dynamics and exploring their relations with socio-economic factors are very significant for regional sustainability. In this study, land use/land cover (LULC) matrix model was used to quantify the relevant capacity of the ES supply, demand and balance in China. Also, we explored the spatial-temporal characteristics of ES at three scales (national, provincial and city scale). The results revealed that the ES supply, demand and balance in China had strong spatial heterogeneity and showed different time-varying characteristics on different scales. For the provinces with ES deficit, linear optimization model was then applied to achieve the theoretical ES balance through land cover conversion. For the provinces with negative regulating ES, farmland should be significantly reduced while desert and grassland should be converted to farmland and forest for the provinces with negative provisioning ES. In addition, the key driving factors of ES dynamics were selected through ordination analysis of 109 cities at city scale. The results showed that forest proportion was the most important influencing factor of ecosystem services supply while ES supply management can be carried out by adjusting the output values of agriculture, forestry and animal husbandry. On the other hand, ES demand can be adjusted by per capita GDP, energy consumption per unit of GDP and permanent population. The results can provide targeted information with ES management and this method can be applied at a smaller scale considering data availability. This study provides a convenient and propagable method for ES quantification and a quantitative support for regional ES management decisions.

Temporal dynamics of SO2 and NOX pollution and contributions of driving forces in urban areas in China.

SO2 and NOX pollution have significantly reduced the air quality in China in past decades. Haze and acid rain have negatively affected the health of animals, plants, and human beings. Documented studies have shown that air pollution is influenced by multiple socioeconomic driving forces. However, the relative contributions of these driving forces are not well understood. In this study, using the structural equation model (SEM), we quantified the contributing effects of various forces driving air pollution in 2015 in prefecture-level cities of China. Our results showed that there has been significant control of SO2 pollution in the past 20 years. The annual average SO2 concentration has dropped from 83 µg/m3 in 1996 to 21 µg/m3 in 2015, while the annual average NOX concentration has increased from 47 µg/m3 in 1996 to 58 µg/m3 in 2015. We evaluated data on the annual average concentrations of SO2, which in some cities may mask the differences of SO2 concentrations between different months. Hence, SO2 pollution should continue to be controlled in accordance with existing policies and regulations. However, we suggest that NOX should become the new focus of air pollution prevention and treatment. The SEM results showed that industrial scale, city size, and residents' activities have a significant impact on NOX pollution. Among these, industrial scale had the highest contribution. The findings from our study can provide a theoretical basis for the formulation of NOX pollution control policy in China.

A regional strategy for ecological sustainability: A case study in Southwest China.

Partitioning, a method considering environmental protection and development potential, is an effective way to provide regional management strategies to maintain ecological sustainability. In this study, we provide a large-scale regional division approach and present a strategy for Southwest China, which also has extremely high development potential because of the "Western development" policy. Based on the superposition of 15 factors, including species diversity, pattern restriction, agricultural potential, accessibility, urbanization potential, and topographical limitations, the environmental value and development benefit in the region were quantified spatially by weighting the sum of indicators within environmental and development categories. By comparing the scores with their respective median values, the study area was divided into four different strategy zones: Conserve zones (34.94%), Construction zones (32.95%), Conflict zones (16.96%), and Low-tension zones (15.16%). The Conflict zones in which environmental value and development benefit were both higher than the respective medians were separated further into the following 5 levels: Extreme conflict (36.20%), Serious conflict (28.07%), Moderate conflict (12.28%), Minor conflict (6.55%), and Slight conflict (16.91%). We found that 9.04% of nature reserves were in Conflict zones, and thus should be given more attention. This study provides a simple and feasible method for regional partitioning, as well as comprehensive support that weighs both the environmental value and development benefit for China's current Ecological Red Line and space planning and for regional management in similar situations.

Spatial Distribution of Metals and Associated Risks in Surface Sediments Along a Typical Urban River Gradient in the Beijing Region.

Surface sediments from Beiyun River located in the rapidly urbanized Beijing metropolis were collected and analyzed for heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn) to investigate their spatial distribution pattern, ecotoxicology and source identification. Results indicated the average heavy metal concentrations of Cd, Cr, Cu, Pb, and Zn were approximately 4, 2, 3, 2, and 4 times higher than their background values. Spatially, we found the concentrations of heavy metals made significant change in four sections along urbanized river gradients. The contents in midstream of urban region and farmland region (section 2 and section 3) were greater than those in upstream (section 1) and downstream (section 4). However, one-way analysis of variance for spatial analysis suggested there were no significant differences between mainstream and tributaries. The geo-accumulation index (I geo) used to assess the sediment quality exhibited there was a decreasing order for the average I geo of measured heavy metals: Zn (0.82) > Cd (0.53) > Cu (0.50) > Cr (- 0.08) > Pb (- 0.45) > Ni (- 0.96) > Mn (- 0.97) > As (- 1.01), whereas they had different "high-low" orders at different sampling transects. Ecological risk index values showed that section 2 and section 3 revealed a high and moderate ecological risk, respectively. Furthermore, principal component analysis indicated the first principle component explained 64.73% of total variance with the main pollutants of As, Cr, Ni, Zn, and Cu which were probably controlled by the mixed sources covering natural factors and anthropogenic input.

Spatio-temporal variations of conservation hotspots based on ecosystem services in Xishuangbanna, Southwest China.

Integrating biodiversity and ecosystem services (BES) has been viewed as an appropriate approach to identifying conservation priorities. Taking Xishuangbanna tropical region in Southwest China, different BESs (habitat quality [used as a proxy for biodiversity], carbon storage, and water yield) were quantified using the InVEST model and conservation hotspots from 1976, 1990, and 2010 were identified by overlapping and ranking the service layers. Results showed that BESs areas were unevenly distributed. High habitat quality and carbon storage areas located in the eastern part of the region were mainly occupied by broad-leaved forest, while high water yield areas were covered by grassland and tropical forests. Recognized hotspots were primarily composed of the broad-leaved forest and shrub grassland. However, these habitat types declined by nearly 50% from 1.25×105 ha to 0.63×105 ha and became more fragmented during the study period. We also found that the sub-watersheds which decreased in BES had fewer hotspots distributed and suffered greater landscape fragmentation. Our study further explored the impacts of land-use conversion on BES, and illustrated the necessity and feasibility of BESs in identifying potential conservation areas.

Spatiotemporal dynamics of grassland aboveground biomass on the Qinghai-Tibet Plateau based on validated MODIS NDVI.

Spatiotemporal dynamics of aboveground biomass (AGB) is a fundamental problem for grassland environmental management on the Qinghai-Tibet Plateau (QTP). Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data can feasibly be used to estimate AGB at large scales, and their precise validation is necessary to utilize them effectively. In our study, the clip-harvest method was used at 64 plots in QTP grasslands to obtain actual AGB values, and a handheld hyperspectral spectrometer was used to calculate field-measured NDVI to validate MODIS NDVI. Based on the models between NDVI and AGB, AGB dynamics trends during 2000-2012 were analyzed. The results showed that the AGB in QTP grasslands increased during the study period, with 70% of the grasslands undergoing increases mainly in the Qinghai Province. Also, the meadow showed a larger increasing trend than steppe. Future AGB dynamic trends were also investigated using a combined analysis of the slope values and the Hurst exponent. The results showed high sustainability of AGB dynamics trends after the study period. Predictions indicate 60% of the steppe and meadow grasslands would continue to increase in AGB, while 25% of the grasslands would remain in degradation, with most of them distributing in Tibet.