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1.
Artigo em Inglês | MEDLINE | ID: mdl-32011752

RESUMO

BACKGROUND: Air pollution, especially PM2.5 (particulate matter with a diameter of below 2.5 µm), has been recognized as a key environmental factor that affects mental health, but few studies have focused on its influence on older adults, who are a vulnerable group. OBJECTIVE: This study focused on the influence of PM2.5 on health-related behaviors, such as physical activities and social contact, to assess their role as mediators of depression among older adults in China. METHODS: We used data (N = 24 623) from the CHARLS (China Health and Retirement Longitudinal Study) of 2011-2015. CES-D 10 (Center for Epidemiology Studies of Depression scale) was used to measure depression. Using multilevel linear models, we examined the relationships between the variables, with different times nested within the same individual and individuals nested within the cities. RESULTS: Before mediators were added, depression symptoms among older adults increased with annual concentration of PM2.5 (Coeff = 0.57, SE = 0.11). However, after the mediators were added, the coefficient of the annual concentration of PM2.5 decreased (Coeff = 0.37, SE = 0.10). While both physical activities (Sobel test Z score = 2.37, P value = .02) and social contact (Z score = 7.33, P value = .00) mediated the relationship between PM2.5 and depression, the mediating effects decreased with increasing PM2.5 . CONCLUSIONS: Exposure to PM2.5 , therefore, increases depressive symptoms in older Chinese adults by decreasing their physical activities and social contact. Also, the positive effects of physical activities and social contact on depression decreased with increasing PM2.5 concentrations.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32057228

RESUMO

Direct growth of vertically-oriented graphene (VG) nanowalls on soda-lime glass has practical significance in extending the application of graphene to daily-life related areas, such as gas sensors and conductive electrodes, via combining their complementary properties and applications. However, low temperature deposition derived VG films (e.g. on glass) usually present relative low conductivity and optical transparency. To tackle this issue, an ethanol-precursor-based, radio-frequency plasma enhanced chemical vapor deposition (rf-PECVD) route for the synthesis of VG-nanowalls is developed in this research, around the softening temperature of soda-lime glass (~600 ℃) templates. The average sheet resistance ~2.4 kΩ·sq-1 (at transmittance ~81.6%) is only one-half of that achieved by a traditional methane-precursor-based PECVD route. Based on the highly conductive and optical transparent VG/glass, as well its scalable size up to 25-inch scale, high-performance reversible thermochromic devices were successfully constructed with VG/glass as transparent heaters. Hereby, this work should propel the scalable synthesis and applications of highly conductive VG films on glass in next-generation transparent electronics and switchable windows.

3.
Sci Total Environ ; 711: 134843, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32000326

RESUMO

China's rapid urbanization has led to an increasing level of exposure to air pollution and a decreasing level of exposure to vegetation among urban populations. Both trends may pose threats to psychological well-being. Previous studies on the interrelationships among greenness, air pollution and psychological well-being rely on exposure measures from remote sensing data, which may fail to accurately capture how people perceive vegetation on the ground. To address this research gap, this study aimed to explore relationships among neighbourhood greenness, air pollution exposure and psychological well-being, using survey data on 1029 adults residing in 35 neighbourhoods in Guangzhou, China. We used the Normalized Difference Vegetation Index (NDVI) and streetscape greenery (SVG) to assess greenery exposure at the neighbourhood level, and we distinguished between trees (SVG-tree) and grasses (SVG-grass) when generating streetscape greenery exposure metrics. We used two objective (PM2.5 and NO2 concentrations) measures and one subjective (perceived air pollution) measure to quantify air pollution exposure. We quantified psychological well-being using the World Health Organization Well-Being Index (WHO-5). Results from multilevel structural equation models (SEM) showed that, for parallel mediation models, while the association between SVG-grass and psychological well-being was completely mediated by perceived air pollution and NO2, the relationship between SVG-tree and psychological well-being was completely mediated by ambient PM2.5, NO2 and perceived air pollution. None of three air pollution indicators mediated the association between psychological well-being and NDVI. For serial mediation models, measures of air pollution did not mediate the relationship between NDVI and psychological well-being. While the linkage between SVG-grass and psychological well-being scores was partially mediated by NO2-perceived air pollution, SVG-tree was partially mediated by both ambient PM2.5-perceived air pollution and NO2-perceived air pollution. Our results suggest that street trees may be more related to lower air pollution levels and better mental health than grasses are.

4.
Mol Oncol ; 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31981446

RESUMO

Although circulating tumor cells (CTCs) have shown promise as potential biomarkers for diagnostic and prognostic assessment in gastric cancer (GC), determining the predictive and prognostic value of programmed death-ligand 1 (PD-L1)-positive CTCs in patients with GC is a challenge. Here, we identified that the expression of total vimentin protein was positively correlated with PD-L1 and inhibited CD8+ T cell activation in patients with GC according to bioinformatics analysis. Notably, co-expression of PD-L1 and cell-surface vimentin (CSV) was detected by immunofluorescence and IHC assay in locally advanced GC tumor specimens and metastatic lymph nodes. Likewise, CSV expression level was significantly decreased after transiently knocking down PD-L1 in GC cell lines. Based on our established CTC detection platform, CTCs were isolated from peripheral blood samples collected from 70 patients (38 resectable and 32 unresectable) with GC using magnetic positive selection and a CSV-specific monoclonal antibody, 84-1. CSV+ PD-L1+ CTCs were observed in 50 of 70 (71%) GC patient samples, ranging from 0 to 261 mL-1 . A higher number of CSV+ PD-L1+ CTCs were significantly associated with a short survival duration and poor therapeutic response. This study demonstrated that detection of PD-L1+ CTCs using a CSV-enrichment method has promising value as a clinically relevant prognostic marker for GC.

5.
J Hazard Mater ; 384: 120948, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31610345

RESUMO

Facile and ultrasensitive detection of Hg2+ in water environment remains challenging. Exonuclease III (Exo-III)-assisted target recycling is one of the most popular amplification strategies. Although the magnesium (II) ions are widely acting as cofactors of Exo-III, we recognized that Mg2+ cofactors would strongly disturb the charge distribution on citrate-stablized gold nanoparticles (in the general sense, unmodified AuNPs) surface, thus generate false positive colorimetric signals. To address this issue, we first put forward the view that the cobalt (II) ions can function as the Exo-III cofactor and successfully construct a novel label-free colorimetric aptasensor for facile and ultrasensitive detection of Hg2+ using Hg2+-triggered Exo-III-assisted signal amplification and unmodified AuNPs as indicators. A hairpin-looped DNA probe was rationally designed with thymine-rich recognition termini and specifically recognized trace Hg2+ by a stable T-Hg2+-T structure. A blue-to-red color change of AuNPs with the addition of Hg2+ provided the quantitative detection of Hg2+ with a limit of detection of 0.2 nM and a linear working range from 0.5 nM to 5.0 nM. The whole testing time for one assay was approximately 40 min. Real water samples, even containing Hg2+ at 1 nM, could be determined by the aptasensor with recovery rates from 97% to 103%.

6.
Hepatology ; 71(1): 130-147, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31148183

RESUMO

Hepatocellular carcinoma (HCC) is one of the fastest-rising causes of cancer-related death worldwide, but its deficiency of specific biomarkers and therapeutic targets in the early stages lead to severe inadequacy in the early diagnosis and treatment of HCC. Covalently closed circular RNA (circRNA), which was once considered an aberrant splicing by-product, is now drawing new interest in cancer research because of its remarkable functionality. Beneath the surface of the dominant functional proteins events, a hidden circRNA-centric noncoding regulatory RNAs network active in the very early stage of HCC is here revealed by a genome-wide analysis of mRNA, circRNA, and microRNA (miRNA) expression profiles. Circ-CDYL (chromodomain Y like) is specifically up-regulated in the early stages of HCC and therefore contributes to the properties of epithelial cell adhesion molecule (EPCAM)-positive liver tumor-initiating cells. Circ-CDYL interacts with mRNAs encoding hepatoma-derived growth factor (HDGF) and hypoxia-inducible factor asparagine hydroxylase (HIF1AN) by acting as the sponge of miR-892a and miR-328-3p, respectively. Subsequently, activation of the phosphoinositide 3-kinase (PI3K)-AKT serine/threonine kinase-mechanistic target of rapamycin kinase complex 1/ß-catenin and NOTCH2 pathways, which promote the expression of the effect proteins, baculoviral IAP repeat containing 5 (BIRC5 or SURVIVIN) and MYC proto-oncogene, is influenced by circ-CDYL. A treatment incorporating circ-CDYL interference and traditional enzyme inhibitors targeting PI3K and HIF1AN demonstrated highly effective inhibition of stem-like characteristics and tumor growth in HCC. Finally, we demonstrated that circ-CDYL expression or which combined with HDGF and HIF1AN are both independent markers for discrimination of early stages of HCC with the odds ratios of 1.09 (95% confidence interval [CI], 1.02-1.17) and 124.58 (95% CI, 13.26-1170.56), respectively. Conclusion: These findings uncover a circRNA-centric noncoding regulatory RNAs network in the early stages of HCC and thus provide a possibility for surveillance and early treatment of HCC.

7.
Health Soc Care Community ; 28(1): 247-259, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31595604

RESUMO

Previous research has found a negative linkage between neighbourhood social participation and depressive symptoms in Western countries, but the cross-sectional design of these studies limits the ability to infer causality. Little attention has been paid to socio-psychological pathways linking neighbourhood social participation to depressive symptoms among older adults in China. This study aimed to examine the impact of neighbourhood social participation on depressive symptoms among older adults in China. It also further explored the mediating roles of physical activity, social contact among neighbours, and contact with own children in the relationship between social participation and depressive symptoms. Data obtained through three waves (2011, 2013, and 2015) of the China Health and Retirement Longitudinal Study were used. The sample consisted of 10,105 individuals aged 60 and above and 24,623 person-year records captured during these three waves. Depressive symptoms were assessed using the Center for Epidemiology Studies of Depression scale. Results showed that respondents' depression decreased with an increasing level of neighbourhood social participation, more time spent on physical activities, and a higher frequency of contact with neighbours and with own children. These factors were found to partly mediate the relationship between neighbourhood social participation and depression. The negative relationships between social contact and depression and contact with own children and depression were both strengthened by neighbourhood social participation. In conclusion, physical activity, social contact among neighbours and contact with own children are mechanisms through which neighbourhood social participation lowers the risk of depression among older adults in China.

8.
Stem Cell Res Ther ; 10(1): 377, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31805987

RESUMO

Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiating into several tissues, such as bone, cartilage, and fat. Glucocorticoids affect a variety of biological processes such as proliferation, differentiation, and apoptosis of various cell types, including osteoblasts, adipocytes, or chondrocytes. Glucocorticoids exert their function by binding to the glucocorticoid receptor (GR). Physiological concentrations of glucocorticoids stimulate osteoblast proliferation and promote osteogenic differentiation of MSCs. However, pharmacological concentrations of glucocorticoids can not only induce apoptosis of osteoblasts and osteocytes but can also reduce proliferation and inhibit the differentiation of osteoprogenitor cells. Several signaling pathways, including the Wnt, TGFß/BMP superfamily and Notch signaling pathways, transcription factors, post-transcriptional regulators, and other regulators, regulate osteoblastogenesis and adipogenesis of MSCs mediated by GR. These signaling pathways target key transcription factors, such as Runx2 and TAZ for osteogenesis and PPARγ and C/EBPs for adipogenesis. Glucocorticoid-induced osteonecrosis and osteoporosis are caused by various factors including dysfunction of bone marrow MSCs. Transplantation of MSCs is valuable in regenerative medicine for the treatment of osteonecrosis of the femoral head, osteoporosis, osteogenesis imperfecta, and other skeletal disorders. However, the mechanism of inducing MSCs to differentiate toward the osteogenic lineage is the key to an efficient treatment. Thus, a better understanding of the molecular mechanisms behind the imbalance between GR-mediated osteoblastogenesis and adipogenesis of MSCs would not only help us to identify the pathogenic causes of glucocorticoid-induced osteonecrosis and osteoporosis but also promote future clinical applications for stem cell-based tissue engineering and regenerative medicine. Here, we primarily review the signaling mechanisms involved in adipogenesis and osteogenesis mediated by GR and discuss the factors that control the adipo-osteogenic balance.

9.
Nanotechnology ; 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31751961

RESUMO

It remains a great challenge to disentangle and disperse multi-walled carbon nanotubes (MWCNTs) in thermoplastics by the existing melt compounding facilities where neither solvent nor liquid chemicals are allowed. In this study, ball milling is applied to disentangle MWCNTs and to eventually liberate each tube from agglomeration, and then the tubes are melt compounded with polyamide-6 (PA6). A uniformly distributed MWCNT network is observed; obvious load transfer from the matrix to the tubes is evidenced by the presence of many firmly embedded tubes on the fracture surface. The electrical conductivity percolation threshold of PA6/MWCNT composites is found to be 2.5-3.0 wt%, in comparison with 5.0-8.0 wt% for PA6/stainless steel fibre composites. The 10.0 wt% composite shows a 76% increase in flexural modulus and 58% in flexural strength.

10.
Int J Equity Health ; 18(1): 178, 2019 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-31752984

RESUMO

BACKGROUND: Exposure to natural outdoor environments (NOE) has been shown to be beneficial to older adults' health and functioning, yet this assertion has rarely been tested in China. We investigated the relationships between exposure to NOE and older adults' self-rated health in Shanghai, China and examined whether these relationships varied by sex, age, education and hukou status. METHOD: This cross-sectional study used micro-data sample of the 2010 Shanghai population census, including 7962 older adults nested within 3345 neighbourhoods. Self-rated health was the outcome variable. Four NOE exposure indicators were calculated for each neighbourhood: the amount of surrounding greenness/blueness and proximity to large green/blue spaces. Multilevel logistic regression was employed to explore the association between natural outdoor environment exposure and self-rated health, adjusting for individual-level and neighbourhood-level covariates. Stratified analyses were used to examine variations by sex, age, education and hukou status. RESULTS: Older adults living in neighbourhoods with higher surrounding greenness and higher proximity to both green spaces and blue spaces were more likely to report good health. Residential surrounding blueness was not significantly related to self-rated health. Females, those aged 60-69 years, those who had elementary school or junior high school education and those with non-local hukou benefit more from residential surrounding greenness, and those aged 70-79 years and who had elementary school or junior high school education benefit more from residential proximity to blue spaces. CONCLUSIONS: Higher residential greenness and proximity to both green spaces and blue spaces were associated with better self-rated health, particularly for females, younger older adults, the low educated and non-local hukou holders. Our findings suggest that urban green spaces and urban blue spaces have different effects on health among Chinese older adults and that the assessment of exposure matters to the investigation of NOE-health relationships.

11.
Mol Med Rep ; 20(5): 4594-4602, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31702033

RESUMO

MicroRNAs (miRs) serve varying and important roles in the pathogenesis of non­traumatic osteonecrosis (ON). However, the role miR­186­5p serves in the pathogenesis of osteonecrosis remains unknown and the clinical outcome of ON is still uncertain. The aim of the present study was to determine the expression characteristics, biological function and molecular mechanisms of miR­186­5p, which is associated with cancer development and progression, in osteoblastic differentiation and cell viability. The results of the present study showed that the expression levels of miR­186­5p were significantly higher in clinical non­traumatic ON compared with osteoarthritis samples (P=0.0001). An inverse association was observed between miR­186­5p and CXCL13 expression levels. Furthermore, miR­186­5p inhibited phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) signaling, downregulated osteoblast­specific markers and reduced the viability and differentiation of human mesenchymal stem cells from bone marrow (HMSC­bm) through targeting CXCL13. Increasing expression of CXCL13 in HMSC­bm cells partially restored miR­186­5p­mediated inhibition. In conclusion, abrogation of PI3K/AKT signaling triggered by miR­186­5p/CXCL13 may contribute to ON pathogenesis. These results highlight the possible clinical value of miR­186­5p in treatment for non­traumatic ON.

12.
Anal Chem ; 91(24): 15811-15817, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31625719

RESUMO

Split aptamers (SPAs) are a pair of oligonucleotide fragments generated by cleaving a long parent aptamer. SPAs have many compelling advantages over the parent aptamer such as sandwich target binding, optimized concise structure, and low cost. However, only a limited number of SPAs have been developed so far because the traditional theory restricts the splitting to the functionally dispensable site that many parent aptamers do not possess. In this work, the traditional mechanism and hypothesis that SPAs can also be generated by splitting the parent aptamer at the functionally essential site while still preserving the biorecognition capability are challenged. To prove the hypothesis, three SPAs with Broken initial small-molecule binding Pockets (BPSPAs) are discovered and their binding capabilities are validated both in the wet lab and in silico. An allosteric binding mechanism of BPSPAs, in which a new binding pocket is formed upon the target binding, is revealed by all-atom microsecond-scale molecular dynamics simulations. Our work highlights the important role of MD simulations in predicting the ligand binding potency with functional nucleic acids at the molecular level. The findings will greatly promote discovery of new SPAs and their applications in molecular sensing in many fields.

13.
ACS Appl Mater Interfaces ; 11(40): 36444-36448, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31525882

RESUMO

Ultrasensitive PCR-free microRNA (miR) analysis based on biosensors with enzyme-free nucleic acid amplification and reusable surface has great clinical significance in cancer prognosis. However, building such a biosensing strategy has long been challenging due to uncontrollable miR-triggered cascade amplifiers and insufficient sensing surface regeneration capability. To meet the challenge, for the first time, a general approach, named enzyme-free multitag-regulated cascade reaction (MCR), is developed to fabricate reliable trace miR biosensors. As a proof of concept, miR let-7a is detected on an evanescent wave fluorescent optical-fiber biosensing platform. The size and morphology of well-formed MCR assemblies (∼1 µm in length) are characterized by atomic force microscopy. This MCR method achieves a 30 000-fold improved sensitivity (detection limit 0.8 fM) compared to the MCR-free system and can detect abnormal urinary miR levels in lung cancer patients. Moreover, the biosensor is robust enough to be reused for over 100 cycles, which greatly reduces the cost of single detection. In sum, MCR is developed as a generalizable ultrasensitive miR biosensing approach for cancer prognosis, which opens a broad field for facile enzyme-free biosensing applications by nucleic acid assembling regulation.

14.
Soc Sci Med ; 238: 112515, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31473573

RESUMO

In the context of population ageing in many developed and developing countries, encouraging active transport behaviors of older adults, is a key public health priority. However, many cross-sectional studies assessing the impact of built environment characteristics on travel behavior fail to address residential self-selection bias, and hence the causal relationship is uncertain. A large-scale public housing scheme provided this study with a unique research opportunity to distinguish residential self-selection from the effects of built environment characteristics on the travel behaviors of older adults (N = 13,468 and 3,961 in two analyses respectively) in Hong Kong, because public housing residents have little freedom to choose their residential locations. The results showed that the elderly living in public housing estates generally have fewer trips, shorter overall travel times and distances, and fewer motorized trips including those by rail or private car than those living in private housing estates. In addition, the results for walking, walking times, numbers of trips, and travel distance for elderly people in public and private housing all exhibited markedly different associations with built environment characteristics. Strength of built environment-travel behavior associations dropped by approximately 30-50% after controlling for the effect of residential self-selection. The results indicate that both built environment characteristics and residential self-selection affect travel behaviors.

15.
Health Place ; 59: 102186, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31400645

RESUMO

Previous studies have shown that perceptions of neighborhood safety are associated with various mental health outcomes. However, scant attention has been paid to the mediating pathways by which perception of neighborhood safety affects mental health. In addition, most previous studies have evaluated perception of neighborhood safety with questionnaires or field audits, both of which are labor-intensive and time-consuming. This study is the first attempt to measure perception of neighborhood safety using street view data and a machine learning approach. Four potential mediating pathways linking perception of neighborhood safety to mental health were explored for 1029 participants from 35 neighborhoods of Guangzhou, China. The results of multilevel regression models confirm that perception of neighborhood safety is positively associated with mental health. More importantly, physical activity, social cohesion, stress and life satisfaction mediate this relationship. The results of a moderation analysis suggest that the beneficial effects of physical activity and social cohesion on mental health are strengthened by a perception of neighborhood safety. Our findings suggest the need to increase residents' perception of neighborhood safety to maintain mental health in urban areas of China.

16.
Mediators Inflamm ; 2019: 5497467, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31467485

RESUMO

Although ionizing radiation (IR) has provided considerable improvements in nasopharyngeal carcinoma (NPC) treatment, radioresistance is still a major threat for some subsets of patients. The insulin-like growth factor-1 receptor (IGF-1R) signaling pathway is tightly regulated and plays critical roles in mediating cell proliferation, growth, and survival. Thus, IGF-1R may be a potential therapeutic target for patients with different malignancies. However, its mechanism in NPC is not fully investigated. Linsitinib is an oral small molecule and is a tyrosine kinase inhibitor (TKI) of IGF-1R, which has been known for antitumor effects used widely. Here, we evaluated the proliferation and radiosensitivity of NPC cell lines (CNE-2 and SUNE-1) after linsitinib treatment. We found that linsitinib suppresses IGF-1-induced cell proliferation through inhibiting Akt and ERK phosphorylation. Moreover, linsitinib further boosted IR-induced DNA damage, G2-M cell cycle delay, and apoptosis in NPC cells. Finally, linsitinib reversed radioresistant NPC cells by decreasing the phosphorylation of IGF-1R. Our data indicated that the combination of linsitinib and IR and targeting IGF-1R by linsitinib could be a promising therapeutic strategy for NPC.


Assuntos
Carcinoma Nasofaríngeo/metabolismo , Receptor IGF Tipo 1/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Humanos , Imidazóis/farmacologia , Fosforilação/efeitos dos fármacos , Fosforilação/efeitos da radiação , Inibidores de Proteínas Quinases/farmacologia , Pirazinas/farmacologia , Radiação Ionizante
17.
BMC Public Health ; 19(1): 1036, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31375090

RESUMO

BACKGROUND: This study aims to investigate the mechanisms through which neighborhood social reciprocity influences older adults' mental health in China. METHODS: This study used data from the 2011-2015 waves of the China Health and Retirement Longitudinal Study. It estimated the effects of neighborhood social reciprocity on older adults' mental health and tested the mediating effects of the frequencies of physical activity, social interaction with neighbors, and volunteering experience. RESULTS: The results indicated that more neighborhood social reciprocity related to better mental health. The effects of the three mediators were statistically significant and enhanced mental health. In addition, the effects of the mediators were strengthened by neighborhood social reciprocity, and vice versa. CONCLUSIONS: In China, neighborhood social reciprocity influenced older adults' mental health directly and through the mechanisms of the frequencies of physical activity, social interaction with neighbors, and volunteering experience.


Assuntos
Exercício/psicologia , Relações Interpessoais , Saúde Mental/estatística & dados numéricos , Características de Residência/estatística & dados numéricos , Voluntários/psicologia , Idoso , China , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Voluntários/estatística & dados numéricos
18.
Health Place ; 58: 102168, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31325813

RESUMO

Although a plethora of studies have investigated the association between green exposure and mental health in developed countries, it is only recently that academics and policymakers have paid attention to how this association works in rapidly urbanizing and developing countries. This study aims to explore biopsychosocial pathways linking residential greenness exposure to depression in the Chinese context using data from the 2016 wave of China Labour-force Dynamics Survey. Results from multilevel models along with mediation analysis show that exposure to residential greenness is negatively associated with depression, and that physical activity, stress and neighbourhood social cohesion altogether have a complete mediation effect on this association. Results from moderation analysis suggest that urbanicity moderates the relationship between greenness exposure and depression, and that the relationship is strongest at the upper level of urbanicity. Our findings suggest the necessity of increasing the provision of recreational green spaces and improving the quality of green spaces in Chinese less urbanized areas.

19.
Sci Total Environ ; 691: 685-696, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325867

RESUMO

To address the harmful algal blooms problem in Lake Erie, one solution is to determine the most cost-effective strategies for implementing agricultural best management practices (BMPs) in the Maumee River watershed. An optimization tool, which combines multi-objective optimization algorithms, SWAT (Soil and Water Assessment Tool), and a computational efficient framework, was created to optimally identify agricultural BMPs at watershed scales. The optimization tool was demonstrated in the Matson Ditch watershed, an agricultural watershed in the Maumee River basin considering critical areas (25% of the watershed with the greatest pollutant loadings per area) and the entire watershed. The initial implementation of BMPs with low expenditures greatly reduced pollutant loadings; beyond certain levels of pollutant reductions, additional expenditures resulted in less significant reductions in pollutant loadings. Compared to optimization for the entire watershed, optimization in critical areas can greatly reduce computational time and obtain similar optimization results for initial reductions in pollutant loadings, which were 10% for Dissolved Reactive Phosphorus (DRP) and 38% for Total Phosphorus (TP); however, for greater reductions in pollutant loadings, critical area optimization was less cost-effective. With the target of simultaneously reducing March-July DRP/TP losses by 40%, the optimized scenario that reduced DRP losses by 40% was found to reduce 51.1% of TP; however, the optimized scenario that reduced TP losses by 40% can only decrease 11.3% of DRP. The optimization tool can help stakeholders identify optimal types, quantities, and spatial locations of BMPs that can maximize reductions in pollutant loadings with the lowest BMP costs.

20.
Int J Health Geogr ; 18(1): 18, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31345233

RESUMO

BACKGROUND: Neighbourhood environment characteristics have been found to be associated with residents' willingness to conduct physical activity (PA). Traditional methods to assess perceived neighbourhood environment characteristics are often subjective, costly, and time-consuming, and can be applied only on a small scale. Recent developments in deep learning algorithms and the recent availability of street view images enable researchers to assess multiple aspects of neighbourhood environment perceptions more efficiently on a large scale. This study aims to examine the relationship between each of six neighbourhood environment perceptual indicators-namely, wealthy, safe, lively, depressing, boring and beautiful-and residents' time spent on PA in Guangzhou, China. METHODS: A human-machine adversarial scoring system was developed to predict perceptions of neighbourhood environments based on Tencent Street View imagery and deep learning techniques. Image segmentation was conducted using a fully convolutional neural network (FCN-8s) and annotated ADE20k data. A human-machine adversarial scoring system was constructed based on a random forest model and image ratings by 30 volunteers. Multilevel linear regressions were used to examine the association between each of the six indicators and time spent on PA among 808 residents living in 35 neighbourhoods. RESULTS: Total PA time was positively associated with the scores for "safe" [Coef. = 1.495, SE = 0.558], "lively" [1.635, 0.789] and "beautiful" [1.009, 0.404]. It was negatively associated with the scores for "depressing" [- 1.232, 0.588] and "boring" [- 1.227, 0.603]. No significant linkage was found between total PA time and the "wealthy" score. PA was further categorised into three intensity levels. More neighbourhood perceptual indicators were associated with higher intensity PA. The scores for "safe" and "depressing" were significantly related to all three intensity levels of PA. CONCLUSIONS: People living in perceived safe, lively and beautiful neighbourhoods were more likely to engage in PA, and people living in perceived boring and depressing neighbourhoods were less likely to engage in PA. Additionally, the relationship between neighbourhood perception and PA varies across different PA intensity levels. A combination of Tencent Street View imagery and deep learning techniques provides an accurate tool to automatically assess neighbourhood environment exposure for Chinese large cities.

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