Xiamen City Research Articles

Distribution Characteristics and Influencing Factors of Organochlorine Pesticides in Agricultural Soil from Xiamen City.

The concentration and distribution of 15 organochlorine pesticides in the soil of Xiamen City were determined. Overall, among the 15 selected target pesticides, 14 organochlorine pesticides (OCPs) were detected (hexachlorobenzene was not). The range of detected pesticides was undetected-10.04 ng/g, the total detection rate was 35.2%, and the three pollutants with the highest detection rate in all samples were Heptachlor (66.7%), δ-Hexachlorocyclohexane (60.0%), and p, p'-Dichlorodiphenyldichloroethane (58.3%). The degree of pollution in descending order was Tong'an > Xiang'an > Jimei > Haicang. Linear regression analysis of soil properties and OCP concentration distribution revealed that OCPs were positively correlated with water content, dissolved organic carbon, and pH and negatively correlated with cation exchange capacity. The origin of OCPs was evaluated using the relationship between the parent compound and its metabolites, with possible new hexachlorocyclohexane and isomer (HCHs) input. By comparing the risk screening values of ΣHCHs and ΣDDTs in "Soil Environmental Quality Standards", the concentrations in all soil samples were lower than the standard values, which indicated that the OCP residues in Xiamen were very low.

Family physician services and blood pressure control in China: A population-based retrospective cohort study.

Given the importance of continuous family physician (FP) care in the management of hypertension, we explored the effects of such care among hypertensive patients in China, a country where such care is generally underutilized. We examined the longitudinal association between the use and continuity of FP services and health outcomes including blood pressure (BP) control rate, systolic blood pressure (SBP), and diastolic blood pressure (DBP). We conducted a population-based cohort study using data from the retrospective regional electronic health record database in Xiamen City, China. The study considered 18,119 hypertensive patients aged over 18 years who had at least two visits to a health center in the preceding 12months. The generalized estimating equation model was adopted to estimate the longitudinal association between FP service utilization and health outcomes. Hypertensive patients treated by their own FPs had a higher BP control rate (OR = 1.14, 95% CI: 1.02-1.28) and lower DBP (-0.36mmHg, 95% CI: -0.52 to -0.20) than those without a FP or those with a FP but treated by a general community physician (GCP). Compared with hypertensive patients treated exclusively by GCPs, patients treated continuously and exclusively by a FP were 45% more likely to have their BP under control (OR = 1.45, 95% CI: 1.32-1.60), and their SBP and DBP were lower by 0.6mmHg (95% CI: -0.78 to -0.39) and 0.6mmHg (95% CI: -0.79 to -0.47), respectively. Hypertensive patients continuously treated by their own FPs performed better in terms of BP control rate, SBP and DBP values. In addition, the number and continuity of FP visits were associated with better BP control.

Microplastic pollution threats coastal resilience and sustainability in Xiamen City, China

Microplastics have raised growing awareness due to their ubiquity and menaces to coastal resilience and sustainability. The abundance, distribution, and characteristics of microplastics in water and organisms in Xiamen were evaluated. Results showed that the average abundance of microplastics in the surface water of Xiamen Bay was 1.55 ± 1.94 items/m3. The dominant color, size, shape, and polymer type were white, 1.0–2.5 mm, and fragments and lines, and polyethylene and polypropylene, respectively. The average abundance of microplastics in the fish in Xiamen was 2.44 ± 1.56 items/g wet weight. They were dominated by fibers of blue polyethersulfone and polyethylene terephthalate, and sizes <2.5 mm. There was a negative correlation between the polymer type in fish and that in water, while a positive correlation between shapes of microplastics of both fish species. Results will aid in formulating management measures for preventing microplastic pollution in Xiamen, ultimately promoting coastal resilience and sustainability of coastal communities.

Exploring Environmental Restoration and Psychological Healing from Perspective of Resilience: A Case Study of Xinglin Bay Landscape Belt in Xiamen, China

We explored the relationship between environmental restoration and psychological healing and the ecological optimization and healing function of the waterfront landscape from the perspective of resilience in the Xinglin Bay landscape belt of Jimei District, Xiamen City, China through qualitative research, in-depth interviews, and field investigations. 63 interviewees were invited from October 12 to 16, 2022 to collect data on their activity and psychological feelings in the area. The results showed that gender and frequency of activities were important variables affecting the effectiveness of landscape healing. Hydrophilic items in the Xinglin Bay landscape adopt the theme of resilience to promote the interaction between people and the environment, thereby subtly changing the cognition of visitors. The results of this study prove the relationship between resilient landscapes and physical and mental healing, highlighting the importance of the resilient design of waterfront landscapes in the urban environment and social development.

Research on Sustainable Evaluation Model of Sponge City Based on Emergy Analysis

Sponge city is a method of managing rain floods, proposed by China to deal with urban waterlogging and the overflow pollution of drainage pipe networks, which indicates a more effective strategy to promote urban sustainable development. Due to the diversity of sponge city construction objectives and the complexity of the developmental system, a unified and effective sustainability evaluation method has not yet been formed. Based on the emergy analysis method, the indicators of ecosystem service, the construction cost, the runoff regulation, and the pollutant reduction of sponge city construction are thus included in the evaluation system, and the sustainable evaluation model of a sponge city is fully constructed. Taking the core area in the south of Haicang in Xiamen City as the studying object, the runoff regulation, and the pollutant reduction indicators, are carefully obtained by using Info Works simulation software. The results showed that: ① the quality of COD (Chemical Oxygen Demand) of pollutants discharged from the research object is 409.8t/a, the total runoff is 3.579 million m3/a, the current annual total runoff control rate is 37.15%, and the current emergy index ESI of sponge city system is 0.05 &lt; 1, which is in an unsustainable state, It is necessary to upgrade and transform the urban underlying surface; ② The transformation intensity of three LID (Low Impact Development) facilities, i.e., concave green space, permeable pavement and green roof, is carefully selected as different construction schemes. When the construction intensity of LID is 25%, the emergy index ESI (Emergy Sustainable Index) = 1.08, which meets the basic requirements of sustainable development; As long as the reconstruction construction intensity is 30%, the growth value of ESI, ΔESI, is the largest, the sustainable growth effect of sponge city construction is the most obvious, and the marginal benefit is the largest; ③ As long as the total annual runoff control rate of the research object is 69–82%, its sustainable energy index ESI should be within the range of 1.39–1.83. If ESI is less than 1.39, this indicates that the total annual runoff control rate of the research area cannot adapt to the planning requirements of 69%.

Grid-Based Essential Urban Land Use Classification: A Data and Model Driven Mapping Framework in Xiamen City

Accurate and timely mapping of essential urban land use categories (EULUC) is vital to understanding urban land use distribution, pattern, and composition. Recent advances in leveraging big open data and machine learning algorithms have demonstrated the possibility of large-scale mapping of EULUC in a new cost-effective way. However, they are still limited by the transferability of samples, models, and classification results across space, particularly across different cities. Given the heterogeneities of environmental and socioeconomic conditions among cities, in-depth studies of data and model adaptation towards city-specific EULUC mappings are highly required to support policy making, and urban renewal planning and management practices. In addition, the trending need for timely and detailed small land unit data processing with finer data granularity becomes increasingly important. We proposed a City Meta Unit (CMU) data model and classification framework driven by multisource data and artificial intelligence (AI) algorithms to address these challenges. The CMU Framework was innovatively applied to systematically set up a grid-based data model and classify urban land use with an improved AI algorithm by applying Moore neighborhood correlations. Specifically, we selected Xiamen, Fujian, in China, a coastal city, as the typical testbed to implement this proposed framework and apply an AI transfer learning technique for grid and parcel land-use study. Experimental results with our proposed CMU framework showed that the grid-based land use classification performance achieves overall accuracies of 81.17% and 76.55% for level I (major classes) and level II (minor classes), which is much higher than the parcel-based land use classification (overall accuracies of 72.37% for level I, and 68.99% for level II). We further investigated the relationship between training sample size and classification performance and quantified the contribution of different data sources to urban land use classifications. The CMU framework makes data collections and processing intelligent and efficient, with finer granularity, saving time and cost by using existing open social data. Incorporating the CMU framework with the proposed grid-based model is an effective and new approach for urban land use classification, which can be flexibly extended and applied to various cities.

Transmissibility of tuberculosis among students and non-students: an occupational-specific mathematical modelling

BackgroundRecently, despite the steady decline in the tuberculosis (TB) epidemic globally, school TB outbreaks have been frequently reported in China. This study aimed to quantify the transmissibility of Mycobacterium tuberculosis (MTB) among students and non-students using a mathematical model to determine characteristics of TB transmission.MethodsWe constructed a dataset of reported TB cases from four regions (Jilin Province, Xiamen City, Chuxiong Prefecture, and Wuhan City) in China from 2005 to 2019. We classified the population and the reported cases under student and non-student groups, and developed two mathematical models [nonseasonal model (Model A) and seasonal model (Model B)] based on the natural history and transmission features of TB. The effective reproduction number (Reff) of TB between groups were calculated using the collected data.ResultsDuring the study period, data on 456,423 TB cases were collected from four regions: students accounted for 6.1% of cases. The goodness-of-fit analysis showed that Model A had a better fitting effect (P < 0.001). The average Reff of TB estimated from Model A was 1.68 [interquartile range (IQR): 1.20–1.96] in Chuxiong Prefecture, 1.67 (IQR: 1.40–1.93) in Xiamen City, 1.75 (IQR: 1.37–2.02) in Jilin Province, and 1.79 (IQR: 1.56–2.02) in Wuhan City. The average Reff of TB in the non-student population was 23.30 times (1.65/0.07) higher than that in the student population.ConclusionsThe transmissibility of MTB remains high in the non-student population of the areas studied, which is still dominant in the spread of TB. TB transmissibility from the non-student-to-student-population had a strong influence on students. Specific interventions, such as TB screening, should be applied rigorously to control and to prevent TB transmission among students.Graphical

Prevalence and risk factors of dementia in elder adults in Xiamen, China: A cross-sectional study.

The prevalence of dementia can vary by region and there is a cluster of more than 10 modifiable risk factors for dementia. Therefore, this study aimed to determine the prevalence of dementia in Xiamen, China, and identify independent risk factors associated with dementia. This cluster sampling-based cross-sectional study enrolled elder adults from Xiamen City and conducted face-to-face interviews between April and August 2019. Data on the demographic characteristics and prevalence of dementia were collected. Multivariable logistic regression was used to analyse the factors associated with dementia. A total of 6430 subjects were enrolled. The prevalence of dementia was 7.62% (490/6430). A total of 490 patients were in the dementia group and 196 healthy matched subjects were selected for the control group with similar profiles for age, gender, and occupation as the dementia patients. Dementia patients were at increased risk for cerebrovascular disease, traumatic brain injury, and hypertension (all P < 0.05). Multivariable logistic regression analysis showed hypertension (odds ratio (OR)=2.4, 95% confidence interval (CI): 1.62-3.63, P < 0.001) and traumatic brain injury (OR=2.19, 95% CI: 1.16-4.53, P=0.023) were independent risk factors for dementia. The prevalence of dementia was high among elder adults residing in Xiamen, China. Dementia patients were more likely to have hypertension and traumatic brain injury than the matched control group.

Spatial and Temporal Distribution and Influencing Factors of Dissolved Trace Metals in Jiulong River Estuary and Xiamen Bay

Trace metals play an important role in some biogeochemical processes in the marine system. The physical and hydrological conditions in estuaries and coastal seawater are complicated and significantly affected by human activities. Therefore, the biogeochemical behavior and influencing mechanism of trace metals in nearshore water have become a research hotspot. Jiulong River estuary and Xiamen Bay are located in the coastal areas of Fujian Province, which are significantly influenced by Longyan, Xiamen, and Zhangzhou City. In July 2021, November 2021, and January 2022, the trace metals chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), and cadmium (Cd) and environmental factors (water temperature, salinity, pH, dissolved oxygen (DO), suspended particulate matter (SPM), etc.) in Jiulong River estuary and Xiamen Bay were investigated. The results showed that the order of trace metal concentration average values measured in Jiulong River estuary and Xiamen Bay was Mn>Ni>Cu>Cr>Co>Cd. In July 2021, the average values of ρ(Cr), ρ(Mn), ρ(Co), ρ(Ni), ρ(Cu), and ρ(Cd) were 0.159, 47.96, 0.068, 1.56, 1.07, and 0.016 μg·L-1, respectively. In November 2021, the average values were 0.216, 8.48, 0.030, 1.70, 1.92, and 0.019 μg·L-1, respectively. The average concentrations in January 2022 were 0.281, 32.39, 0.062, 2.21, 1.54, and 0.034 μg·L-1, respectively. The concentration of dissolved metals in the estuary was higher than that in the bay area. Principal component analysis showed that the main factors affecting the concentrations of dissolved trace metals were river runoff and anthropogenic activities.

The effects of jobs, amenities, and locations on housing submarkets in Xiamen City, China

Numerous studies have found that jobs, amenities, and location influence housing prices in urban areas. However, there is still a lack of in-depth understanding of the impacts of these factors on various housing submarkets within a city. With the case study of Xiamen, this paper investigates the impacts of jobs, amenities, and location on four housing submarkets, classified by owner-occupied and rental housing, in inner and outer districts. The hedonic model, Chow test, and Tiao-Goldberger test are applied to analyze differentiation in the determinants of housing prices between four submarkets. The results show that all submarkets are influenced by blue-collar jobs (which have negative effects) and seascape (which has a positive impact). Besides, differentiated after submarkets show that school districts and public transportation have a greater influence on owner-occupied markets than on rental markets. A heterogeneity exists between inner-district and outer-district markets. For instance, bus rapid transit (BRT) has a positive effect on housing and rental prices in the outer districts but not in the inner districts. These differences are mainly caused by the disparities of spatial quality, economic development, and public facilities and amenities. The findings have profound implications for decision-making and planning practices.

Assessment of the effects of integrated coastal zone management based on synthetic control method

As a policy tool to promote sustainable development of coastal zone cities, Integrated Coastal Zone Management (ICZM) was introduced to China for experimentation in the 1990s. Among them, the Xiamen government took ICZM as an opportunity to conduct a large number of policy pilots, making the evaluation of the policy effects worth studying. This paper takes Xiamen city as the research object based on 180,000 samples from 188 Chinese municipalities from 1980-2017. Based on the theoretical framework of the Social-Economic-Natural Complex Ecosystem (SENCE), we use the synthetic control method (SCM) to conduct its two rounds of policy pilots. The study found that the first round of experiments focused on environmental pollution prevention and control, and the economic development gap between Xiamen and similar coastal zone cities was narrowed despite the economic lag effect. Finally, based on robustness tests, policy recommendations are made for coastal zone cities.

THERMAL ENVIRONMENT OF RESIDENTIAL COMMUNITIES OVER A COAST AREA IN SOUTHEASTERN CHINA

Abstract. The characters of the residential communities over Tong’an District of Xiamen City in thermal environment as well as in biophysical factors were investigated mainly based on the Lansat-8 OLI/TIRS Collection 2 Level-2 products. Specifically, the surface temperature product was used in measuring thermal environment, and the surface reflectance product was used to derive biophysical factors through the tasseled cap transformation as well as the normalized difference vegetation index (NDVI). Among the four types of residential community, the old community in urban area was generally lower in NDVI and in the Wetness component and therefore had higher surface temperature. Varied relationships of surface temperature with biophysical factors among four types were observed, which also demonstrated seasonal variation. At the same time, the preliminary investigation showed that the residential communities located in rural-urban fringe and a small portion of village communities had confronted with problems in thermal environment as well as in surface biophysical conditions. Furthermore, limitations of this study were discussed, mainly in spatial resolution and temporal representativeness of the Landsat-8 OLI/TIRS data, in biophysical components derived from the multi-spectral reflectance without depicting actual landscape, and in no consideration for the background of individual community. As the whole district covers wide and complex territory along with different local climate types, more investigations in details are required.

Anthropogenic Influences on the Hydrochemical Characteristics of the Groundwater in Xiamen City, China and Their Evolution

This study analyzed the anthropogenic influences on the hydrochemical composition characteristics of the groundwater in Xiamen City, Fujian province, China, and their evolution. Based on the hydrochemical data of the groundwater of 1993 and 2019–2021, this study identified the indices of the anthropogenic influences using mathematical and statistical analysis methods, such as contrast coefficient, standard deviation, and Mahalanobis distance. The analytical results are summarized as follows: (1) the number of the indices affecting the groundwater quality in Xiamen increased from nine in 1993 to 15 in 2019, and the six increased indicators included NO3−, Pb, NH4+, Al3+, NO2− and Cu (the contribution rates to poor-quality were 26.0%, 16.3%, 10.6%, 4.1%, 0.8% and 0.8%, respectively) which were related to the input of human activities. During this period, the number of hydrochemical types increased from 19 in 1993 to 28 in 2019, with a decrease in the water of the HCO3 type and an increase in the water of Cl and SO4 types; (2) In 2019, NO3− had higher content than SO42− in the groundwater and became a major anion, forming the water of NO3 type; (2) as indicated by the analytical results obtained using the Mahalanobis distance method, areas with strong anthropogenic influences include densely populated areas and areas with intensively distributed industrial enterprises, while anthropogenic influences are very weak in the northern forest land area.

Urban heat vulnerability: A dynamic assessment using multi-source data in coastal metropolis of Southeast China.

Extreme heat caused by global climate change has become a serious threat to the sustainable development of urban areas. Scientific assessment of the impacts of extreme heat on urban areas and in-depth knowledge of the cross-scale mechanisms of heat vulnerability forming in urban systems are expected to support policymakers and stakeholders in developing effective policies to mitigate the economic, social, and health risks. Based on the perspective of the human-environment system, this study constructed a conceptual framework and index system of "exposure-susceptibility-adaptive capacity" for urban heat vulnerability (UHV) and proposed its assessment methods. Taking Xiamen City, a coastal metropolis, as an example, spatial analysis and Geodetector were used to explore the spatial and temporal changes, spatial characteristics, and patterns of UHV under multiple external disturbances from natural to anthropological factors, and to reveal the main factors influencing UHV forming and spatial differentiation. Results showed that the exposure, susceptibility, adaptive capacity, and UHV in Xiamen City had a spatial structure of "coastal-offshore-inland". On the hot day, both the exposure and UHV showed a temporal pattern of "rising and then falling, peaking at 14:00" and a spatial pattern of "monsoonal-like" movement between coast and inland. Coastal zoning with favorable socioeconomic conditions had less magnitude of changes in UHV, where the stability of the urban system was more likely to be maintained. During the hot months, the high UHV areas were mainly distributed in the inland, while coastal areas showed low UHV levels. Further, coastal UHV was mainly dominated by "heat exposure", offshore by "comprehensive factors", and inland in the northern mountainous areas by "lack of adaptive capacity". Multi-scale urban adaptive capacity was confirmed to alter spatial distribution of exposure and reshape the spatial pattern of UHV. This study promotes the application of multi-scale vulnerability framework to disaster impact assessment, enriches the scientific knowledge of the urban system vulnerability, and provides scientific references for local targeted cooling policy development and extreme heat resilience building programs.

Multifractal and Long-Term Memory of Impervious Surface Spatial Patterns in a Coastal City in China

An understanding of the multifractal and long-range dependence of impervious surfaces (IS) spatiotemporal patterns is helpful for regional environmental assessment and urban planning. Linear spectral-mixture analysis has been applied to compute IS in the coastal city of Xiamen, China, based on Landsat TM/OLI/TIRS images, and then the long-term trends and multifractal characteristics of IS patterns have been investigated using two-dimensional multifractal detrended fluctuation analysis. The IS spatial distribution displayed similar positive long-range correlations in study areas during the 1994–2015 period. IS have a long-memory characteristic within a certain spatial range, with an increase in the value of a pixel likely to cause an increment in the value of its neighbors. The multifractality of the IS distribution increased in Xiamen City during 1994–2015, but was lower than those in Xiamen Island. The multifractal spectra in Xiamen City vary in shape between years, capturing its evolution from right truncation with a long left tail to left truncations and long right tails and then a symmetrical shape. The fractal structure for Xiamen Island exhibits similar patterns of long right tails and left truncations. Economic and political considerations coupled with natural geographic conditions dominate the long-range trends in the IS spatial patterns.

Research on the spatial-temporal pattern and spatial spillover effect of tourism based on mobile signaling and POIs data: a case study of Xiamen city, southeast China

ABSTRACT The purpose of this study is to investigate the spatio-temporal pattern and spatial effect of tourism in a single city. Firstly,the mobile signaling data is used to verify the objective existence of tourism temporal and spatial patterns and spillover effects.Secondly, multi-period POIs data combined with the spatial Dubin model (SDM) are used to clarify the spatial spillover effect betweenscenic spots in Xiamen. This study provides a reference for the optimal allocation of tourism space with the help of spatio-temporalbig data.

Spatiotemporal Response of Ecosystem Service Values to Land Use Change in Xiamen, China

This research aims to identify the key indicators of land-use change that affect ecosystem service in the coastal city of Xiamen. The methods of transfer matrix and land-use dynamic degree are used to analyze land-use change, and the spatial distribution of ecosystem service values (ESV) is mapped from 1989 to 2018 using cluster analysis. During this 30-year period, the built-up land expanded rapidly through occupation of farmland and landfilling of the watershed. The biggest contribution to the reduction of ESV in this stage is the loss of farmland followed by the loss of watershed. By 2018, the spatial distribution of ESV had become very unbalanced and polarized. The high-value areas are mainly distributed in the northern mountainous areas, with the low-value areas concentrated in the flat areas near the coastline, and only a few medium-value areas of ESV remained. Generally, from 1989 to 2018, the ESV in Xiamen decreased by about CNY 200 million in total, with the largest proportion of ESV reduction (CNY 120 million) occurring in the 2000–2010 period. Considering ESV categories, the significant reduction of Regulating Service (53.5–57.8%) was mainly due to the loss of water areas (CNY −70 million) to low ESV areas (built-up land) in urbanization, followed by the loss of farmland (CNY −50 million). This means that Xiamen should strengthen the protection of ecological lands in future urban planning to alleviate and reverse the current ecological imbalance.

Adverse childhood experiences, sexual orientation, and depressive symptoms among Chinese college students: An ecological framework analysis

BackgroundExtensive evidence has demonstrated that adverse childhood experiences (ACEs) predict a high risk of negative health and behavioral outcomes in later life. However, the influence of individuals' psychosocial characteristics and environmental stressors have been mostly omitted in previous research. ObjectiveThis study aimed to examine the prevalence of ACEs among LGB (lesbian, gay, and bisexual) and heterosexual emerging adults, and the associations between different patterns of ACE exposure and depressive symptoms after adjusting for factors at different levels. Participants and settingA representative sample of 928 college students in Xiamen city, China was recruited. MethodsLatent class analysis was applied to identify the patterns of ACEs. A series of regression analyses were conducted to examine the associations between ACEs and depression and whether ACEs interacted with sexual identity to influence depression, after controlling for individual characteristics, family, school, and society-level factors. ResultsOver 35 % of the participants reported they had experienced at least one type of moderate to extreme childhood maltreatment, and those who identified as LGB reported a higher level of ACE exposure. Higher levels of ACE exposure based on score and clustering approaches were associated with higher risks of depression among Chinese emerging adults. However, the associations between ACEs and depression were not significantly moderated by sexual identity. ConclusionsThe findings highlighted the importance of early screening for ACEs particularly among sexual minorities and of delivering tailored interventions based on ecological backgrounds. Both the traditional scoring approach and a data-driven approach can be effective in detecting the cumulative effect of ACEs.

A follow-up study to explore factors associated with rapid kidney function decline and new-onset kidney disease among Chinese elderly population.

To explore potential factors associated with rapid kidney function decline and new-onset kidney disease among a Chinese elderly population, and to examine the relationships between baseline serum uric acid (SUA), longitudinal change in SUA and rapid estimated glomerular filtration rate (eGFR) decline over 5 years for this Chinese elderly population. A 5-year follow-up study was conducted from 2016 to 2020 in Xiamen City, China; and 2436 elderly people with normal kidney function at baseline was included. The multivariable logistic regressions were used to explore risk factors for rapid eGFR decline and new-onset kidney disease. The median age of subjects was 65 years, and 38.5% were men. These elderly people experienced a median 5-year decrease in eGFR of 14.50 mL/min/1.73 m2 , and 11.2% of them had developed new-onset kidney disease after 5-year follow-up. Participants with elevated SUA change from the normal group to the hyperuricemia group witnessed the highest decrease of eGFR after a 5-year follow-up than other groups. Multivariate analysis found advanced age, female, elevated baseline SUA, elevated SUA change, hypertension and triglyceride-glucose index were risk factors for rapid eGFR decline and new-onset kidney disease. The Chinese elderly population was more likely to encounter rapid renal function decline and new-onset kidney disease. A regular test for kidney disease was strongly recommended for these elderly people who were female, with advanced age, with elevated baseline SUA and elevated SUA change; and had high levels of insulin resistance, and blood pressure. The derived findings can offer significant evidence for targeted prevention for the Chinese elderly population. Geriatr Gerontol Int 2022; 22: 968-975.

Optimization of Cold Chain Distribution Route with Mixed Time Window considering Customer Priority

In order to study the mixed time window vehicle routing optimization problem based on customer priority, a customer differentiation management strategy based on customer priority is proposed. Combined with the main factors affecting customer priority evaluation and the characteristics of vehicle routing problem with mixed time windows, a comprehensive evaluation index affecting customer priority was first established and DBSCAN clustering algorithm was used for clustering analysis of customer priority to solve the optimization problem of cold chain distribution route considering customer priority. Fuzzy time window of refrigerated vehicles was then constructed with trapezoidal fuzzy number, and a mathematical programming model was built with an objective function for minimizing the sum of fixed, green, penalty, refrigeration, and cargo damage costs. Two scenarios of out-of-stock and not-out-of-stock were designed. Finally, an improved genetic algorithm was used to solve the model, and the rationality of the model was verified through a case of imported fruit distribution in Xiamen City. Results showed that the proposed method can effectively solve the routing problem of refrigerated trucks considering customer priority. Moreover, the findings of this study can provide a new approach for solving the routing optimization problem of refrigerated trucks considering customer priority.