Sources-attributed contributions to health risks associated with PM2.5-bound polycyclic aromatic hydrocarbons during the warm and cold seasons in an urban area of Eastern Asia.

Despite the well-established recognition of the health hazards posed by PM2.5-bound PAHs, a comprehensive understanding of their source-specific impact has been lacking. In this study, the health risks associated with PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) and source-specific contributions were investigated in the urban region of Taipei during both cold and warm seasons. The levels of PM2.5-bound PAHs and their potential health risks across different age groups of humans were also characterized. Diagnostic ratios and positive matrix factorization analysis were utilized to identify the sources of PM2.5-bound PAHs. Moreover, potential source contribution function (PSCF), concentration-weighted trajectory (CWT) and source regional apportionment (SRA) analyses were employed to determine the potential source regions. Results showed that the total PAHs (TPAHs) concentrations ranged from 0.08 to 2.37 ng m-3, with an average of 0.69 ± 0.53 ng m-3. Vehicular emissions emerged as the primary contributor to PM2.5-bound PAHs, constituting 39.8 % of the TPAHs concentration, followed by industrial emissions (37.6 %), biomass burning (13.8 %), and petroleum/oil volatilization (8.8 %). PSCF and CWT analyses revealed that industrial activities and shipping processes in northeast China, South China Sea, Yellow Sea, and East China Sea, contributed to the occurrence of PM2.5-bound PAHs in Taipei. SRA identified central China as the primary regional contributor of ambient TPAHs in the cold season and Taiwan in the warm season, respectively. Evaluations of incremental lifetime cancer risk demonstrated the highest risk for adults, followed by children, seniors, and adolescents. The assessments of lifetime lung cancer risk showed that vehicular and industrial emissions were the main contributors to cancer risk induced by PM2.5-bound PAHs. This research emphasizes the essential role of precisely identifying the origins of PM2.5-bound PAHs to enhance our comprehension of the related human health hazards, thus providing valuable insights into the mitigation strategies.

Effects of drying method and oil type on edible polyunsaturated oleogels co-structured by hydroxylpropyl methyl cellulose and xanthan gum.

The subtle balance between the interactions of polysaccharide molecules and the interactions of polysaccharide molecules with oil molecules is significantly important for developing polysaccharide-based polyunsaturated oleogels. Here, hydroxylpropyl methyl cellulose and xanthan gum were used to structure edible oleogels via emulsion-template methodology, while the effects of drying methods (hot-air drying (AD) and vacuum-freeze drying (FD)) and oil types (walnut, flaxseed and Moringa seed oil) on the structure, oil binding capacity (OBC), rheological properties, thermal behaviors and stability of oleogels were specially investigated. Compared with AD oleogels, FD oleogels exhibited significantly better OBC, enhanced gelation strength (G' value) and better capacity to holding oil after high temperature processing, which was attributed to the possibly increased oil-polysaccharide interactions. However, the weakened polysaccharide-polysaccharide interactions in FD oleogels failed in providing stronger physical interface or enough rigidity to restrict the migration of oil molecules. Polyunsaturated triacylglycerols in vegetable oils deeply participated in the construction of the network of AD oleogels through weak intermolecular non-covalent interactions, which in turn greatly changed the crystallization and melting behaviors of vegetables oils. In brief, this research may provide useful information for the development of polysaccharide-based polyunsaturated oil oleogels.

Sarsasapogenin inhibits YAP1-dependent chondrocyte ferroptosis to alleviate osteoarthritis.

The involvement of chondrocyte ferroptosis in the development of osteoarthritis (OA) has been observed, and Sarsasapogenin (Sar) has therapeutic promise in a variety of inflammatory diseases. This study investigates the potential influence of Sar on the mechanism of chondrocyte ferroptotic cell death in the progression of osteoarthritic cartilage degradation. An in vivo medial meniscus destabilization (DMM)-induced OA animal model as well as an in vitro examination of chondrocytes in an OA microenvironment induced by interleukin-1ß (IL-1ß) exposure were employed. Histology, immunofluorescence, quantitative RT-PCR, Western blot, cell viability, and Micro-CT analysis were utilized in conjunction with gene overexpression and knockdown to evaluate the chondroprotective effects of Sar in OA progression and the role of Yes-associated protein 1 (YAP1) in Sar-induced ferroptosis resistance of chondrocytes. In this study we found Sar reduced chondrocyte ferroptosis and OA progression. And Sar-induced chondrocyte ferroptosis resistance was mediated by YAP1. Furthermore, infection of siRNA specific to YAP1 in chondrocytes reduced Sar's chondroprotective and ferroptosis-suppressing effects during OA development. The findings suggest that Sar mitigates the progression of osteoarthritis by decreasing the sensitivity of chondrocytes to ferroptosis through the promotion of YAP1, indicating that Sar has the potential to serve as a therapeutic approach for diseases associated with ferroptosis.

Porous MgO-modified biochar adsorbents fabricated by the activation of Mg(NO3)2 for phosphate removal: Synergistic enhancement of porosity and active sites.

Engineering magnesium oxide (MgO)-modified biochar (MgO-biochar) with high porosity and active MgO load is a feasible pathway to enhance phosphate adsorption capacity. However, the blockage to pores caused by MgO particles is ubiquitous during the preparation, which seriously impaired the enhancement in adsorption performance. In this research, with the intent to enhance phosphate adsorption, an in-situ activation method based on Mg(NO3)2-activated pyrolysis technology was developed to fabricate MgO-biochar adsorbents with abundant fine pores and active sites simultaneously. The SEM image revealed that the tailor-made adsorbent has well-developed porous structure and abundant fluffy MgO active sites. Its maximum phosphate adsorption capacity was coming up to 1809 mg/g. The phosphate adsorption isotherms are in accordance well with the Langmuir model. The kinetic data, which agreed with the pseudo-second-order model, indicated that chemical interaction is existing between phosphate and MgO active sites. This work verified that the phosphate adsorption mechanism on MgO-biochar was composed of protonation, electrostatic attraction, monodentate complexation and bidentate complexation. In general, the facile in-situ activation method using Mg(NO3)2 pyrolysis illuminated biochar activation with fine pores and highly efficient adsorption sites for efficient wastewater treatment.

Spatiotemporal epidemiology of COVID-19 from an epidemic course perspective.

Although coronavirus disease 2019 (COVID-19) remains rampant in many countries, it has recently waned in Sichuan, China. This study examined spatiotemporal variations of the epidemiological characteristics of COVID-19 across its course. Three approaches, i.e. calendar-based, measure-driven and data-driven ones, were applied to all individual cases reported as of 30th November 2020, dividing the COVID-19 pandemic into five periods. A total of 808 people with confirmed diagnosis and 279 asymptomatic cases were reported, the majority of whom were aged 30-49 and <30 years, respectively. The highest risk was seen in Chengdu (capital city), with 411 confirmed and 195 asymptomatic cases. The main sources of infection changed from importation from Hubei Province to importation from other provinces, then local transmission and ultimately importation from foreign countries. The periods highlighted by the three methods presented different epidemic patterns and trends. The calendar-based periods were even with most cases aggregated in the first period, which did not reflect various transmission patterns of COVID-19 due to various sources of infection; the measure-driven and data-driven periods were not consistent with each other, revealing that the effects of implementing prevention measures were reflected on the epidemic trend with a time lag. For example, the decreasing trends of new cases occurred 7, 3 and 4 days later than the firstlevel emergency response, the district-level prevention measures and the second-level emergency response, respectively. This study has advanced our understanding of epidemic course and foreshown all stages of COVID-19 epidemic. Many countries can learn from our findings about what will occur next in their timelines and how to be better prepared.

Neighbourhood residential density and childhood obesity.

Residential density is considered an important attribute of the built environment that may be relevant to childhood obesity. However, findings remain inconclusive, and there are no reviews yet on the association between residential density and childhood obesity. This study aimed to systematically review the associations between residential density and weight-related behaviours and outcomes. A comprehensive literature search was conducted using the Cochrane Library, PubMed and Web of Science for articles published before 1 January 2019. A total of 35 studies conducted in 14 countries were identified, including 33 cross-sectional studies, one longitudinal study and one containing both study designs. Residential density was measured by Geographic Information Systems in 28 studies within a varied radius from 0.25 to 2 km around the individual residence. Our study found a general positive association between residential density and physical activity (PA); no significant associations were observed. This study provided evidence for a supportive role of residential density in promoting PA among children. However, it remained difficult to draw a conclusion between residential density and childhood obesity. Future longitudinal studies are warranted to confirm this association.

Street connectivity, physical activity, and childhood obesity: A systematic review and meta-analysis.

Street connectivity, as a neighbourhood built environmental factor, may affect individual physical activity (PA) and subsequently weight status. However, these associations remain inconclusive. This study aimed to systematically review the association between street connectivity and childhood obesity. A literature search was conducted in the Cochrane Library, PubMed, and Web of Science for articles published before January 1, 2019. All original studies that investigated the association between street connectivity and weight-related behaviours or outcomes among children and adolescents were included. Forty-seven articles were identified, including eight longitudinal and 41 cross-sectional studies conducted in eight countries. The sample size ranged from 88 to 46 813. Street intersection density (SID), measured by Geographic Information Systems in 36 studies and reported in 13 studies, was the main indicator used to represent street connectivity. Forty-four studies examined the association between SID and weight-related behaviours, including overall PA (n = 15), moderate-to-vigorous PA (n = 13), active transport (n = 12), dog walking (n = 1), walking (n = 1), sedentary behaviours (n = 2), and TV viewing (n = 1). Fifteen studies focused on the association between SID and weight-related outcomes. Overall, evidence from this systematic review and meta-analyses suggested a positive association between street connectivity and PA. However, it was difficult to draw a conclusion on the association between street connectivity and BMI. More longitudinal evidence is needed to confirm the causal association between street connectivity and weight status.

Neighbourhood speed limit and childhood obesity.

As an important factor for neighbourhood walkability, the speed limit in the neighbourhood may influence children's physical activity (PA) outdoors, especially active transport, and further their weight status. This review aimed to systematically evaluate the association between neighbourhood speed limit and obesity-related behaviours and outcomes among children and adolescents. PubMed, Embase and Web of Science were systematically searched for relevant studies published from the inception of the database to 1 January 2019. Sixteen studies were included, with 13 cross-sectional studies and three longitudinal studies. Speed limit was measured as the percentage/number of high-speed roads, perception of safe driving speed, perception of speeding and use of traffic-calming tools in the neighbourhood. Eleven studies measured the use of active transport as the outcome of interest, and seven studies measured PA directly. Eleven studies revealed an association between a lower speed limit and increased PA, whereas one study showed a negative association, and three studies reported non-significant associations. Only one study associated speed limit with weight status, which reported a non-significant association. This review generally supported a negative association between speed limit and PA among children and adolescents. More studies are needed to examine their causality, as well as the association between speed limit and weight status, in order to increase the impact of this research area on public health policy making.

Land use mix in the neighbourhood and childhood obesity.

Land use mix (LUM) in the neighbourhood is an important aspect for promoting healthier lifestyles and consequently reducing the risk for childhood obesity. However, findings of the association between LUM and childhood obesity remain controversial. A literature search was conducted on Cochrane Library, PubMed and Web of Science for articles published before 1 January 2019. In total, 25 cross-sectional and two longitudinal studies were identified. Among them, Geographic Information Systems were used to measure LUM in 15 studies, and perceived LUM was measured in 12 studies. Generally, most studies revealed an association between a higher LUM and higher PA levels and lower obesity rates, although some studies also reported null or negative associations. The various exposure and outcome assessment have limited the synthesis to obtain pooled estimates. The evidence remains scare on the association between LUM and children's weight status, and more longitudinal studies are needed to examine the independent pathways and causality between LUM and weight-related behaviours/outcomes.

Maternal residential greenness and congenital heart defects in infants: A large case-control study in Southern China.

BACKGROUND: Proximity to greenness has shown protective effects on coronary heart diseases by limiting exposure to environmental hazards, encouraging physical activity, and reducing mental stress. However, no studies have previously evaluated the impacts of greenness on congenital heart defects (CHDs). We examined the association between maternal residential greenness and the risks of CHDs. METHODS: We conducted a case-control study (8042 children with major CHDs and 6887 controls without malformations) in 21 cities in Southern China, 2004 - 2016. CHDs cases were diagnosed and verified by obstetrician, pediatrician, or pediatric cardiologists, within one year. We estimated maternal residential greenness using satellite-derived normalized difference vegetation index (NDVI) in zones of 500 meters (m) and 1000 m surrounding participants' residences. Logistic regression models were used to assess NDVI-CHD relationships adjusting for confounders. RESULTS: Interquartile range NDVI increases within 500 m or 1000 m were associated with odds ratios (OR) of 0.95 (95% confidence interval (CI): 0.92, 0.98) and 0.94 (95%CI: 0.91, 0.97) for total CHDs respectively. Air pollutants mediated 52.1% of the association. We also identified a protective threshold at 0.21 NDVI on CHD. Similar protective effects from greenness were found in most CHDs subtypes. The protective associations were stronger for fall, urban or permanent residents, higher household income maternal age ≤35 years of age, and high maternal education (ORs: ranged from 0.85 to 0.96). CONCLUSION: Our findings suggest a beneficial effect of maternal residential greenness on CHDs. Further studies are needed to confirm our findings, which will help to refine preventive health and urban design strategies.

Hydrological connectivity dynamics of tidal flat systems impacted by severe reclamation in the Yellow River Delta.

River deltas contain complex self-organizing channel networks that continuously exchange fluxes of water, matter, energy, and information with their surroundings. The connectivity of these exchange processes plays a crucial role in controlling the evolution and dynamic stability of river deltas. However, connectivity patterns related to tidal channel networks have rarely been studied, especially in the Yellow River Delta (YRD), which is impacted by severe reclamation. Here, we evaluated the potential hydrological connectivity dynamics between the tidal channel network and its surroundings using an index of connectivity (IC) in the whole YRD and its three sub-regions: erosion zone, oil field zone and deposition zone. The results suggested that different areas had different spatial connectivity potential. The mean value of the IC related to the channel networks showed little difference for any zones. However, the total connectivity response area (CRA; set of connectivity response units) varied with the study scale. A decreasing trend was found on the delta scale and a relatively stable trend was found in the deposition zone. In terms of dynamic connectivity, the tidal flat system did not show a continuous trend over time. Our results indicated that the YRD is such a dynamic complex that a relatively stable connectivity pattern is unlikely to be achieved over time. Therefore, future ecological restoration based on hydrological connectivity needs to consider more related influencing factors and their temporal and spatial dynamics.

Intensive land uses modify assembly process and potential metabolic function of edaphic bacterial communities in the Yellow River Delta, China.

Coastal reclamation is a global threat to natural ecosystems, disturbing biological community structure, diversity and ecological function through habitat conversion. We have limited insights into the changes brought about by coastal reclamation for different land-use types. We used the Yellow River Delta (YRD) as a model because it is a region with intensive land reclamation, and we investigated the structural and functional variations of bacterial communities and their relations to edaphic properties under different land-use types. Our results showed that the high soil organic carbon (SOC), nitrate concentrations and salinity were found in oil field, aquaculture pond and salt pan, respectively, and low values in natural wetland. Land use was found to have significant influence on bacterial community diversity. To investigate the phylogenetic conservation of specific traits, we analyzed the relationship between soil bacterial assembly processes and edaphic properties. Bacterial traits phylogenetically conserved, and differs in depth. Our findings suggest that SOC served as a deep trait due to it negative correlation with deeper branches of phylogenetic clustering, while nitrate functioned as a shallow trait due to its positive correlation with phylogenetic clustering at finer branches. Soil salinity acted as a complex trait effected on both finer and deeper branches. Further potential functional gene co-occurrence network analysis revealed that land reclamation induced shifts of metabolic function by altering the functional gene connectivity. We found that the photosynthesis pathway was enriched in hub modules related to oil field (OF), while methane metabolism was enriched in hub modules linked to sea cucumber pond (CP1). In addition, two-component systems (TCS) were enriched with nitrate, ammonia, SOC and salinity-related modules. Therefore, our study highlights the importance of integrating multi-function and multi-process identification and prediction of coastal diverse reclamation impacts on coastal ecosystems.

Assessing the relationship between anthropogenic heat release warming and building characteristics in Guangzhou: A sustainable development perspective.

We assessed the spatial heterogeneity of warming due to total anthropogenic heat release (AHR) and building anthropogenic heat release under different heat release scenarios and its relationship with building properties in the highly urbanized portion of Guangzhou using the Weather Research and Forecasting (WRF) model. The simulation results show that different AHR scenarios result in different temperature rise outcomes. A rise of 0.40 °C and 0.23 °C results from a normal total AHR scenario and normal building AHR scenario, while a rise of 0.71 °C and 0.41 °C arises when total AHR and building AHR is doubled. This indicates that more anthropogenic heat results in a more serious warming effect. Moreover, the spatial heterogeneity of the AHR-caused temperature rise is affected by the building area. The AHR-derived warming effect is most serious in high-height-medium-density (H-M) and high-height-high-density (H-H) building areas, where temperature rose by 0.36 °C and 0.34 °C due to building AHR under two AHR scenarios, while it was least serious in low-height-high-density (L-H) and high-height-low-density (H-L) areas, where temperature rose by 16 °C and 0.25 °C under two building AHR scenarios. When AHR is doubled, the hot spot of AHR-derived warming tends to become more concentrated. The quantitative relationship between building AHR-derived warming and building property data was assessed using a multiple linear regression model. The model shows that the combination of building height and building density provides better predictor of building AHR warming than either property alone; and the relationship is best predicted in L-H and H-L areas, with R2 values of 0.68 and 0.79, respectively. Warming due to AHR should be considered as one of the most serious urban warming forces and the land surface properties are the key factors that influence AHR-derived warming. This study provides evidence for the significance of AHR in the urban environment and offers suggestions for mitigating urban thermal heating.

Species, Abundance and Function of Ammonia-oxidizing Archaea in Inland Waters across China.

Ammonia oxidation is the first step in nitrification and was thought to be performed solely by specialized bacteria. The discovery of ammonia-oxidizing archaea (AOA) changed this view. We examined the large scale and spatio-temporal occurrence, abundance and role of AOA throughout Chinese inland waters (n = 28). Molecular survey showed that AOA was ubiquitous in inland waters. The existence of AOA in extreme acidic, alkaline, hot, cold, eutrophic and oligotrophic environments expanded the tolerance limits of AOA, especially their known temperature tolerance to -25 °C, and substrate load to 42.04 mM. There were spatio-temporal divergences of AOA community structure in inland waters, and the diversity of AOA in inland water ecosystems was high with 34 observed species-level operational taxonomic units (OTUs; based on a 15% cutoff) distributed widely in group I.1b, I.1a, and I.1a-associated. The abundance of AOA was quite high (8.5 × 10(4) to 8.5 × 10(9) copies g(-1)), and AOA outnumbered ammonia-oxidizing bacteria (AOB) in the inland waters where little human activities were involved. On the whole AOB predominate the ammonia oxidation rate over AOA in inland water ecosystems, and AOA play an indispensable role in global nitrogen cycle considering that AOA occupy a broader habitat range than AOB, especially in extreme environments.