Spatial response of urban land use intensity to ecological networks: a case study of Xi'an Metropolitan Region, China.

In the face of the persistent degradation of ecological environments and fragmentation of ecological networks brought about by rapid urbanization, this study focuses on examining the interaction between urban land use intensity and ecological networks in the Xi'an Metropolitan Region (XAMR), China, and their impact on ecological equilibrium and sustainable development. By comprehensively evaluating the changes in land use intensity in XAMR from 2010 to 2020, the aim is to underscore the pivotal role of ecological networks in maintaining urban ecological balance and promoting sustainable development. The findings indicate a transition in land use intensity in the XAMR from low to high concentration, reflecting an intensification in land resource utilization during urbanization. However, the establishment and management of ecological networks can significantly enhance urban ecological security and biodiversity. Notably, this research identified crucial ecological corridors and source areas, augmenting the connectivity of urban green infrastructure and providing vital support for urban biodiversity. Additionally, a significant finding of this study is the spatial spillover effects generated by socioeconomic factors such as the proportion of tertiary and secondary industries and per capita GDP through the ecological network, which have profound impacts on land use intensity in the surrounding areas. These insights offer a novel understanding of the complex interactions within urban ecosystems, emphasizing the importance of incorporating ecological network construction in urban planning. Overall, through a comprehensive analysis of the relationship between the ecological network and land use intensity in the XAMR, this study proposes new directions for urban ecosystem management and land use planning, highlighting the significance of scientific ecological network planning and management in achieving long-term sustainable development in urbanization processes.

Influence of aeration modes and DO on simultaneous nitrification and denitrification in treatment of hypersaline high-strength nitrogen wastewater using sequencing batch biofilm reactor (SBBR).

Sequencing batch biofilm reactor (SBBR) has the potential to treat hypersaline high-strength nitrogen wastewater by simultaneous nitrification-denitrification (SND). Dissolved oxygen (DO) and aeration modes are major factors affecting pollutant removal. Low DO (0.35-3.5 mg/L) and alternative anoxic/aerobic (A/O) mode are commonly used for municipal wastewater treatment, however, the appropriate DO concentration and operation mode are still unknown under hypersaline environment because of the restricted oxygen transfer in denser extracellular polymeric substances (EPS) barrier and the decreased carbon source consumption during the anoxic phase. Herein, two SBBRs (R1, fully aerobic mode; R2, A/O mode) were used for the treatment of hypersaline high-strength nitrogen wastewater (200 mg/L NH4+-N, COD/N of 3 and 3% salinity). The results showed that the relatively low DO (2 mg/L) could not realize effective nitrification, while high DO (4.5 mg/L) evidently increased nitrification efficiency by enhancing oxygen transfer in denser biofilm that was stimulated by high salinity. A stable SND was reached 16 days faster with a ∼10% increase of TN removal under A/O mode. Mechanism analysis found that denser biofilm with coccus and bacillus were present in A/O mode instead of filamentous microorganisms, with the secretion of more EPS. Corynebacterium and Halomonas were the dominant genera in both SBBRs, and HN-AD process might assist partial nitrification-denitrification (PND) for highly efficient TN removal in biofilm systems. By using the appropriate operation mode and parameters, the average NH4+-N and TN removal efficiency could respectively reach 100% and 70.8% under the NLR of 0.2 kg N·m-3·d-1 (COD/N of 3), which was the highest among the published works using SND-based SBBRs in treatment of saline high-strength ammonia nitrogen (low COD/N) wastewater. This study provided new insights in biofilm under hypersaline stress and provided a solution for the treatment of hypersaline high-strength nitrogen (low COD/N) water.

Effects of landscape pattern on water quality at multi-spatial scales in Wuding River Basin, China.

Urbanization and agricultural land use have led to water quality deterioration. Studies have been conducted on the relationship between landscape patterns and river water quality; however, the Wuding River Basin (WDRB), which is a complex ecosystem structure, is facing resource problems in river basins. Thus, the multi-scale effects of landscape patterns on river water quality in the WDRB must be quantified. This study explored the spatial and seasonal effects of land use distribution on river water quality. Using the data of 22 samples and land use images from the WDRB for 2022, we quantitatively described the correlation between river water quality and land use at spatial and seasonal scales. Stepwise multiple linear regression (SMLR) and redundancy analyses (RDA) were used to quantitatively screen and compare the relationships between land use structure, landscape patterns, and water quality at different spatial scales. The results showed that the sub-watershed scale is the best spatial scale model that explains the relationship between land use and water quality. With the gradual narrowing of the spatial scale range, cultivated land, grassland, and construction land had strong water quality interpretation abilities. The influence of land use type on water quality parameter variables was more distinct in rainy season than in the dry season. Therefore, in the layout of watershed management, reasonably adjusting the proportion relationship of vegetation and artificial building land in the sub-basin scale and basin scope can realize the effective control of water quality optimization.

Effects of land-use change on carbon emission and its driving factors in Shaanxi Province from 2000 to 2020.

Exploring the process of carbon emissions under the "carbon peaking and carbon neutrality goals" can contribute to sustainable economic development. This research takes Shaanxi Province as an example. We elaborated on the spatial and temporal characteristics of land-use change from 2000 to 2020 and adopted the carbon emission model method to calculate land-use carbon emissions, also used urban morphological indicators to reveal the main factors of carbon emission changes. The results show that from 2000 to 2020, the land-use change in Shaanxi Province is mainly reflected in the increase in construction land area and the decrease in agricultural land area. Among them, the construction land area increased by 2192 km2, and the agricultural land area decreased by 5006 km2. Land-use carbon emissions increased by 1.28 × 1011 kg during this period. Construction land is a major contributor to carbon emissions. The forestland is the main carbon sink. Carbon emissions showed a spatial pattern of "high in the north, low in the south, and concentrated in the middle." Urban form change is the driving factor affecting land-use carbon emissions in Shaanxi Province. The results of the research contribute to the understanding of regional carbon emission mechanisms and provide a scientific basis for reducing carbon emissions.

Effects of land use and slope on water quality at multi-spatial scales: a case study of the Weihe River Basin.

Exploring the impact of land use and slope on basin water quality can effectively contribute to the protection of the latter at the landscape level. This research concentrates on the Weihe River Basin (WRB). Water samples were collected from 40 sites within the WRB in April and October 2021. A quantitative analysis of the relationship between integrated landscape pattern (land use type, landscape configuration, slope) and basin water quality at the sub-basin, riparian zone, and river scales was conducted based on multiple linear regression analysis (MLR) and redundancy analysis (RDA). The correlation between water quality variables and land use was higher in the dry season than in the wet season. The riparian scale was the best spatial scale model to explain the relationship between land use and water quality. Agricultural and urban lands had a strong correlation with water quality, which was most affected by land use area and morphological indicators. In addition, the greater the area and aggregation of forest land and grassland, the better the water quality, while urban land presented larger areas with poorer water quality. The influence of steeper slopes on water quality was more remarkable than that of plains at the sub-basin scale, while the impact of flatter areas was greater at the riparian zone scale. The results indicated the importance of multiple time-space scales to reveal the complex relationship between land use and water quality. We suggest that watershed water quality management should focus on multi-scale landscape planning measures.

Association between blood selenium levels and gestational diabetes mellitus: A systematic review and meta-analysis.

Introduction: The association between blood (serum or plasma) selenium concentrations and gestational diabetes mellitus (GDM) has been evaluated in some studies. However, the reported findings are debatable, and only case-control and cross-sectional studies were included. Objective: This research aimed to assess the association between blood selenium levels and GDM by analyzing existing literature. To provide a reference for the prevention and treatment of GDM, we included prospective studies which are not included in previous studies to collate more high-quality evidence and better test the etiological hypothesis between blood Se concentrations and GDM. Methods: The PubMed, EMBASE, and Web of Science databases were retrieved for literature up to September 2022, and relevant references were manually searched. Raw data from relevant studies were extracted, and a random effect model was adopted for meta-analysis. The total effects were reported as weighted mean differences. All data were analyzed using Stata 16.0 software. Results: Fourteen studies involving 890 pregnant women with GDM and 1618 healthy pregnant women were incorporated in the meta-analysis. Pregnancies with GDM had significantly lower blood selenium levels than those with normal glucose tolerance (weighted mean difference = -8.11; 95% confidence interval: -12.68 to -3.54, P = 0.001). Subgroup analyses showed that the association between blood selenium levels and GDM was consistent in the residents of Asia and Africa, but not in European. This trend was significant in the second and third trimester subgroups, but not in the first trimester subgroup. Articles published in 2006-2015 also showed this trend, but those published before 2005 and 2016-2019 did not show significant results. This difference was evident in non-prospective studies, but not significant in prospective studies. Studies using the Carpenter and Coustan diagnostic criteria were consistent with this trend, whereas studies using other diagnostic criteria found no differences. In addition, in terms of blood selenium measurement methods, atomic absorption spectrometry showed more significant differences than other methods. In the subgroup analysis based on the sample size of included studies and the quality of the studies, each subgroup showed statistical differences. Conclusion: Lower blood selenium concentrations are associated with GDM as shown in our study. Therefore, supplementing an appropriate amount of selenium may be helpful for GDM prevention and treatment.

Occupational injuries and psychological support in Chinese nurses: a cross-sectional study.

OBJECTIVE: To assess the occupational injuries and psychological support received by nurses and to investigate the relationship between the two. METHOD: This was a nation-wide cross-sectional study of nurses working across 1858 hospitals in China. Data were collected using an online structured, self-administered questionnaire between 2016 and 2017. RESULTS: Nearly half of respondents had experienced aggressive behavior from patients or their attendants; 13.4% respondents had experienced aggressive behavior on more than three occasions. 78.96% respondents had experienced needle-stick injuries and 51.22% had experienced psychological trauma. 20.5% respondents believed that hospitals do not pay any attention to occupational safety. 86.1% respondents expressed the need for little or moderate psychological support. Nurses who had experienced aggressive behavior expressed a greater need for psychological support. Nurses working at hospitals that adequately addressed the occupational safety issues expressed the lowest need for psychological support. CONCLUSION: We found a high prevalence of psychological stress and occupational injuries among nurses. Nursing managers need to address this issue and implement interventions to prevent and reduce injuries.

Occupational injuries and psychological support in Chinese nurses: a cross-sectional study / Lesiones laborales y apoyo psicológico en enfermeras chinas: un estudio transversal / Lesões ocupacionais e apoio psicológico em enfermeiras chinesas: um estudo transversal

ABSTRACT Objective: To assess the occupational injuries and psychological support received by nurses and to investigate the relationship between the two. Method: This was a nation-wide cross-sectional study of nurses working across 1858 hospitals in China. Data were collected using an online structured, self-administered questionnaire between 2016 and 2017. Results: Nearly half of respondents had experienced aggressive behavior from patients or their attendants; 13.4% respondents had experienced aggressive behavior on more than three occasions. 78.96% respondents had experienced needle-stick injuries and 51.22% had experienced psychological trauma. 20.5% respondents believed that hospitals do not pay any attention to occupational safety. 86.1% respondents expressed the need for little or moderate psychological support. Nurses who had experienced aggressive behavior expressed a greater need for psychological support. Nurses working at hospitals that adequately addressed the occupational safety issues expressed the lowest need for psychological support. Conclusion: We found a high prevalence of psychological stress and occupational injuries among nurses. Nursing managers need to address this issue and implement interventions to prevent and reduce injuries.

RESUMO Objetivo: Avaliar os acidentes de trabalho e o apoio psicológico recebido pelos enfermeiros e investigar a relação entre os dois. Método: Este foi um estudo transversal nacional de enfermeiras que trabalham em 1858 hospitais na China. Os dados foram coletados por meio de um questionário online estruturado e autoaplicável entre 2016 e 2017. Resultados: Quase metade dos entrevistados experimentou comportamento agressivo por parte dos pacientes ou de seus acompanhantes; 13,4% dos entrevistados experimentaram comportamento agressivo em mais de três ocasiões. 78,96% dos entrevistados sofreram ferimentos com agulhas e 51,22% sofreram traumas psicológicos. 20,5% dos entrevistados acreditam que os hospitais não dão atenção à segurança do trabalho. 86,1% dos entrevistados expressaram a necessidade de pouco ou moderado apoio psicológico. Enfermeiros que vivenciaram comportamento agressivo expressaram maior necessidade de apoio psicológico. Os enfermeiros que trabalham em hospitais que abordam de forma adequada as questões de segurança do trabalho expressam a menor necessidade de apoio psicológico. Conclusão: Encontramos alta prevalência de estresse psicológico e lesões ocupacionais entre os enfermeiros. Os gerentes de enfermagem precisam abordar essa questão e implementar intervenções para prevenir e reduzir lesões.

RESUMEN Objetivo: Evaluar las lesiones ocupacionales y el apoyo psicológico que reciben las enfermeras e investigar la relación entre ambos. Método: Este fue un estudio transversal a nivel nacional de enfermeras que trabajaban en 1858 hospitales en China. Los datos se recopilaron mediante un cuestionario autoadministrado estructurado en línea entre 2016 y 2017. Resultados: Casi la mitad de los encuestados había experimentado un comportamiento agresivo por parte de los pacientes o sus asistentes; El 13,4% de los encuestados había experimentado un comportamiento agresivo en más de tres ocasiones. El 78,96% de los encuestados había experimentado lesiones por pinchazos de aguja y el 51,22% había experimentado un trauma psicológico. El 20,5% de los encuestados cree que los hospitales no prestan atención a la seguridad laboral. El 86,1% de los encuestados expresó la necesidad de un apoyo psicológico escaso o moderado. Las enfermeras que habían experimentado un comportamiento agresivo expresaron una mayor necesidad de apoyo psicológico. Las enfermeras que trabajan en hospitales que abordaron adecuadamente los problemas de seguridad ocupacional expresaron la menor necesidad de apoyo psicológico. Conclusión: Encontramos una alta prevalencia de estrés psicológico y lesiones ocupacionales entre enfermeras. Los gerentes de enfermería deben abordar este problema e implementar intervenciones para prevenir y reducir las lesiones.

Conductive Skeleton-Heterostructure Composites Based on Chrome Shavings for Enhanced Electromagnetic Interference Shielding.

Renewable bio-based electromagnetic interference (EMI) shielding materials receive increasing attention undoubtedly. However, there is still a challenge to use raw biomass materials to construct a significant structure through an effortless and environmental route for EMI shielding applications. Herein, for the first time, we demonstrated a hybrid composite of multi-walled carbon nanotube/polypyrrole/chrome-tanned collagen fiber (MWCNT/PPy/CF), which utilized waste chrome shavings as a matrix. X-ray photoelectron spectroscopy reveals that the chromium on the CF has a binding effect on the PPy layer, which endows the tight integration between the CF and PPy layer. After the MWCNT network was loaded on the PPy layer, this ternary structure could provide stable conductive paths and a rich number of polarized interfaces. The MWCNT/PPy/CF composite exhibits superior electrical conductivity (354 ± 52 S/m), higher than PPy/CF (222 ± 38 S/m) and MWCNT/CF (104 ± 11 S/m), owing to the synergy of dual conductive structures. Notably, the shielding effectiveness (SE) value of the MWCNT/PPy/CF composite reaches 30 dB in the X band at a thickness of 0.48 mm. The shielding effectiveness of reflection (SER) (9.1 dB) is similar to that of PPy/CF (8.2 dB), while the shielding effectiveness of absorption (SEA) is significantly improved from 15.3 dB (PPy/CF) to 20.4 dB (MWCNT/PPy/CF) due to the additional coverage of the MWCNT network. This indicates the synergy between the MWCNT network and conductive PPy/CF skeleton. This work provided a method to prepare sustainable and low-cost renewable EMI shielding materials using chrome shavings. Meanwhile, this novel structure combining a conductive skeleton and heterostructure can be considered as a potential application in relevant fields.