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1.
J Hazard Mater ; 476: 135002, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38925050

RESUMO

Designing an electrode that can generate abundant free radicals and 1O2, which can effectively degrade and detoxify organophosphorus pesticides (OPPs) through a co-oxidation pathway, is important. In this study, we prepared a electrode GO/MoS2@AS by supporting MoS2 on alum sludge (AS) under graphene oxide (GO) nanoconfinement. The results show that the dominant role of 1O2 at the cathode and •OHads at the anode for degradation, in addition to the involvement of 1O2 in the cathodic degradation mechanism, can be attributed to the abundant precursor •O2- and H2O2. Furthermore, calculations using density functional theory and toxicity prediction of products show that the energy (∆E) requirements of •OHfree to break the C-O bond of the pyridine ring and phosphate group are higher than that required for 1O2, and this non-radical oxidation plays a key role in detoxification. In contrast, accelerating ring opening and oxidation processes are attributed to radical oxidation. Above all, the cathodic detoxification is more effective than anodic detoxification. Three prevalent OPPs, chlorpyrifos, glyphosate, and trichlorfon, were degraded in the GO/MoS2@AS system by over 90 %, with mineralization rates of 76.66 %, 85.46 %, and 82.18 %, respectively. This study provides insights into the co-oxidation degradation and detoxification mechanism mediated by 1O2 and •OHfree.

2.
J Hazard Mater ; 471: 134457, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38688224

RESUMO

Few reports have focused on using particle electrodes with polar adsorbent properties in heterogeneous electro-Fenton (EF) system to improve the degradation of hydrophilic organic pollutants (HLOPs). In this study, a hydrophilic electrode Sn-Sb/AS was prepared by supporting metals Sn and Sb on alum sludge (AS), which can effectively degrade 91.68%, 92.54%, 89.62%, and 96.24% of the four types of HLOPs, chlorpyrifos (CPF), atrazine (ATZ), diuron (DIU), and glyphosate (PMG), respectively, within 40 min. The mineralization rates were 82.37%, 78.93%, 73.98%, and 85.65% for CPF, ATZ, DIU, and PMG, respectively. Based on the analysis of Electron Paramagnetic Resonance test, quenching test, and identified anthracene endoperoxide, the degradation at the cathode was attributed to non-radical oxidation via interaction with 1O2. In contrast, the anodic oxidation occurred via direct electron transfer at the anode and/or oxidation via interaction with adsorbed •OH (•OHads) around the particle electrodes. Furthermore, the reaction sites were calculated by Density functional theory (DFT) and Fukui function, corresponding to the electrophilic attack (fA-) of 1O2 and anodic direct oxidation, besides, the radical attack (fA0) of •OH(ads). Herein, this study proposes a targeted elimination strategy for HLOPs in wastewater treatment using particle electrodes with polar adsorbent properties in EF system.

3.
J Mater Chem B ; 12(3): 814-827, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38189164

RESUMO

Polymerisation shrinkage and biofilm accumulation are the two main problems associated with dental resin composites (DRCs) that induce secondary caries, which can cause restoration failure. Polymerisation shrinkage can lead to microleakage gaps between the tooth and the DRCs, causing the aggregation of bacteria and development of secondary caries. Reducing the shrinkage stress (SS) and improving the resistance to bacterial adhesion have always been the focus of this field in modifying DRCs. A thiol-ene resin system can effectively reduce the polymerisation SS via its step-growth mechanism for delaying the gel point. Fluorinated compounds can reduce the surface free energies, thereby reducing bacterial adhesion. Thus, in this study, a range of mass fractions (0, 10, 20, 30, and 40 wt%) of a fluorinated thiol-ene resin system were added to a fluorinated dimethacrylate resin system/tricyclo decanedimethanol diacrylate to create a fluorinated methacrylate-thiol-ene ternary resin matrix. DRCs were prepared using the obtained ternary resin matrix, and their physical and chemical properties, effect on bacterial adhesion, and biocompatibility were investigated. The results demonstrated that the volumetric shrinkage and SS of the DRCs were reduced with no reduction in conversion degree even after the thiol-ene resin system was added. All DRC-based fluorinated resin systems exhibited an excellent anti-bacterial adhesion effect, as evidenced by the colony-forming unit counts, live/dead bacterial staining, and crystal violet staining tests against Streptococcus mutans (S. mutans). The genetic expressions associated with the bacterial adhesion of S. mutans were substantially affected after being cultured with fluorinated DRCs. All fluorinated DRCs demonstrated good biocompatibility through the in vitro cytotoxicity test and live/dead staining images of the L-929 cells. The above results illustrate that the DRCs based on the fluorinated methacrylate-thiol-ene resin matrix can be potentially applied in clinical practice due to their low SS and anti-bacterial adhesion effect.


Assuntos
Resinas Compostas , Metacrilatos , Resinas Compostas/farmacologia , Teste de Materiais , Metacrilatos/farmacologia , Metacrilatos/química , Compostos de Sulfidrila/química , Bactérias
4.
Front Pharmacol ; 13: 1029598, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36467090

RESUMO

Neuroendocrine carcinoma of the cervix (NECC) is a highly aggressive and rare gynecological malignancy with a poor prognosis. Despite aggressive local and systemic treatments, there are high rates of locoregional recurrence and distant metastases. Therefore, more potent treatments are required to manage NECC. In recent years, emerging immune checkpoint inhibitors, such as programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors, have been used in treating various solid tumors and provide a new direction for immune-targeted therapy for NECC. In this review, we summarize the biomarkers useful for the evaluation of the therapy with PD-1/PD-L1 inhibitors in patients with NECC and the clinical applications and prospects of monotherapy with PD-1/PD-L1 inhibitors and combinations with other therapies in patients with NECC. In some individual case reports, therapeutic strategies with PD-1/PD-L1 inhibitors showed good efficacy. Further studies are needed to confirm the possibility of using PD-1/PD-L1 inhibitors as a standard treatment strategy in NECC.

5.
Front Oncol ; 12: 892376, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35677154

RESUMO

Background: Debulking cytoreduction surgery with bowel resection is a common intervention for ovarian cancer. It is controversial whether ostomy causes worse survival outcomes and how clinical physicians should choose which patients to undergo ostomy. During this study, we performed a systematic review to determine whether ostomy leads to worse outcomes after bowel resection compared to anastomosis. We also summarized the possible indications for ostomy. Methods: We searched PubMed, Embase, and Cochrane for articles containing the phrase "ovarian cancer with bowel resection" that were published between 2016 and 2021. We included studies that compared primary anastomosis with ostomy. We mainly focused on differences in the anastomotic leakage rate, length of hospital stay, overall survival, and other survival outcomes associated with the two procedures. Results and Conclusion: Of the 763 studies, three were ultimately included in the systematic review (N=1411). We found that ostomy did not contribute to worse survival outcomes, and that the stoma-related complications were acceptable. Indications for ostomy require further study. Bowel resection segment margins and the distance from the anastomosis to the anal verge require consideration.

6.
Front Oncol ; 12: 879889, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35574324

RESUMO

Objective: This study evaluated the oncologic outcomes of laparoscopy and laparotomy in the management of early-stage ovarian cancer patients. Methods: We conducted an observational study of women diagnosed with International Federation of Gynecology and Obstetrics (FIGO) 2014 stage I ovarian cancer who underwent surgery at the West China Second University Hospital from 2012 to 2020. Patients who received adjuvant chemotherapy before surgery, those with non-epithelial histopathological types, or those with insufficient data were excluded. Using propensity score matching, data from consecutive laparoscopic patients treated by laparoscopy were matched 1:2 with a cohort of patients undergoing open surgery. The operative and survival outcomes among the matched cohorts were examined using the Kaplan-Meier method. Results: Among 200 eligible patients, 74 patients undergoing laparoscopy were compared with a cohort of 126 patients undergoing open surgery. Baseline characteristics were similar between groups after matching. Patients who had laparoscopy had a shorter operative time (P = 0.001), a shorter hospital stay (P <0.001), and lower blood loss (P = 0.001) than patients who had open surgery. The median (range) follow-up period was 43.0 (38.8-47.2) and 45.0 (36.0-54.0) months for cases and controls, respectively (P <0.001). There are no significant differences in progression-free survival (P = 0.430, log-rank test) and overall survival (P = 0.067, log-rank test) between the two groups. Conclusions: There is no difference in prognosis between laparoscopic and open surgery in women with stage I epithelial ovarian cancer. Laparoscopic treatment of early-stage ovarian cancer is safe and feasible for stage I epithelial ovarian cancer patients.

7.
Ying Yong Sheng Tai Xue Bao ; 33(4): 894-900, 2022 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-35543039

RESUMO

With continuous increases in the amount and duration of plastic film used, the residual film in farmland soil is accumulated and tended to be fragmented, which affects soil water infiltration. We carried out an experiment of one-dimensional vertical infiltration of soil moisture. We examined the effects of different residual film density and area on soil water cumulative infiltration under 21 experimental treatments with 5 residual film area levels (0.25, 0.5, 1, 2, 8 cm2) and 5 residual film density levels (0, 60, 180, 300, 420 kg·hm-2). The results showed that soil water infiltration rate was accelerated and the total infiltration amount was increased by adding a certain amount of residual film into the clay loam soil with bulk density of 1.53 g·cm-3. The total infiltration amount of different residual film area always appeared mutation or turning point when the single residual film area was 1 cm2. When the residual film area and density were larger or smaller than that, the cumulative infiltration amount would be significantly affected, with the treatment of 0.5 cm2 residual film area and 200 kg·hm-2 residual film density being obvious demarcation. When the residual film area was 0.25 cm2, the cumulative infiltration reached the maximum. When the residual film with a single area ≤0.25 cm2 was uniformly mixed into the soil, the slope of soil water cumulative infiltration curve was significantly different from that of other residual film treatments, forming a "new structure" soil with unique water infiltration characteristics.


Assuntos
Solo , Água , Agricultura/métodos , China , Plásticos , Água/análise
8.
Artigo em Inglês | MEDLINE | ID: mdl-35627758

RESUMO

Rapid socio-economic development has had a significant impact on land use/cover (LULC) changes, which bring great pressure to the ecological environment. LULC changes affect ecosystem services by altering the structure and function of ecosystems. It is of great significance to reveal the internal relationship between LULC changes and ecosystem service value (ESV) for the protection and restoration of ecological environments. In this study, based on the spatial and temporal evolution of ecological service values in the Manas River basin from 1980 to 2020 and considering ecological and economic benefits, we coupled the gray multi-objective optimization model (GMOP) and patch-generating land-use simulation (PLUS) model (GMOP-PLUS model) to optimize the LULC structure under three scenarios (a natural development scenario, ND; ecological priority development scenario, (EPD); and balanced ecological and economic development scenario, EED) in 2030, and analyzed the trade-offs and synergies in the relationships among the four services. We found that from 1980 to 2020, farmland and construction land expanded 2017.90 km2 and 254.27 km2, respectively, whereas the areas of grassland and unused land decreased by 1617.38 km2 and 755.86 km2, respectively. By 2030, the trend of LULC changes will be stable under the ND scenario, the area of ecological land will increase by 327.42 km2 under the EPD scenario, and the area of construction land will increase most under the EED scenario, reaching 65.01 km2. From 1980 to 2020, the ESV exhibited an upward trend in the basin. In 2030, the ESV will increase by 7.18%, 6.54%, and 6.04% under the EPD, EED, and ND scenarios, respectively. The clustering of the four services is obvious in the desert area and around the water system with "low-low synergy" and "high-high synergy"; the plain area and mountainous area are mainly "high-low trade-off" and "low-high trade-off" relationships. This paper provides a scientific reference for coordinating economic development and ecological protection in the basin. It also provides a new technical approach to address the planning of land resources in the basin.


Assuntos
Ecossistema , Rios , China , Conservação dos Recursos Naturais , Desenvolvimento Econômico
9.
Environ Pollut ; 293: 118583, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34861335

RESUMO

Salinization is recognized as a threat to agricultural productivity and land resources in global arid desert regions. To date, field soil improvement schemes have met with minimal success to date. We aimed to improve saline-alkali soils by assessing the effects of combining subsurface pipe (Pa) and vertical well (Sa) drainage measures on agricultural soils ecosystem. In a five-year field experiment, soil was sampled 0.5 m, 5 m, 7.5 m horizontally away from the Pa, and 0.5 m, 30 m, 60 m horizontally away from the Sa. Findings indicate that the soil electrical conductivity (EC) decreased from 16 dS m-1 to 3 dS m-1 at a 0-80 cm depth, and the soil desalination efficiency was great at the 0-300 cm depths (≥ 32%) than at the 400-700 cm depths (-14%-74.7%). The combined Pa and Sa drainage measures significantly decreased the species richness and quantity of soil microbial communities, and their negative impact on observed species was irreversible within 1 year. The farther the horizontal sampling conducted from the Pa and Sa, the greater the structural similarity of the microbial community at the genus level, higher the catalase, acidic protease, and neutral phosphatase activities, and lower the alkaline phosphatase activity. The overall decrease in groundwater level from 2016 to 2020 was 5.7 m. The seed cotton yield increased by 3.2 t ha-1. The results suggest that the value of saline-alkali soil can be improved by combining Pa and Sa drainage measures. Our research provides guidance for further effective utilization of agricultural water and soil resources and the sustainable development of the soil ecosystem in arid desert areas.


Assuntos
Microbiota , Solo , Agricultura , Álcalis , Clima Desértico
10.
Viruses ; 13(6)2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203647

RESUMO

Influenza is a highly known contagious viral infection that has been responsible for the death of many people in history with pandemics. These pandemics have been occurring every 10 to 30 years in the last century. The most recent global pandemic prior to COVID-19 was the 2009 influenza A (H1N1) pandemic. A decade ago, the H1N1 virus caused 12,500 deaths in just 19 months globally. Now, again, the world has been challenged with another pandemic. Since December 2019, the first case of a novel coronavirus (COVID-19) infection was detected in Wuhan. This infection has risen rapidly throughout the world; even the World Health Organization (WHO) announced COVID-19 as a worldwide emergency to ensure human health and public safety. This review article aims to discuss important issues relating to COVID-19, including clinical, epidemiological, and pathological features of COVID-19 and recent progress in diagnosis and treatment approaches for the COVID-19 infection. We also highlight key similarities and differences between COVID-19 and influenza A to ensure the theoretical and practical details of COVID-19.


Assuntos
COVID-19/epidemiologia , Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/epidemiologia , SARS-CoV-2/patogenicidade , Saúde Global , Humanos , Pandemias/prevenção & controle , Pandemias/estatística & dados numéricos , Organização Mundial da Saúde
11.
J Virol ; 95(11)2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33692211

RESUMO

Age is a risk factor for coronavirus disease 2019 (COVID-19) associated morbidity and mortality in humans; hence, in this study, we compared the course of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection in young and aged BALB/c mice. We found that SARS-CoV-2 isolates replicated in the respiratory tracts of 12-month-old (aged) mice and caused pathological features of pneumonia upon intranasal infection. In contrast, rapid viral clearance was observed 5 days following infection in 2-month-old (young) mice with no evidence of pathological changes in the lungs. Infection with SARS-CoV-2 elicited significantly upregulated production of cytokines, especially interleukin 6 and interferon gamma, in aged mice; whereas this response was much weaker in young mice. Subsequent challenge of infected aged BALB/c mice with SARS-CoV-2 resulted in neutralized antibody responses, a significantly reduced viral burden in the lungs, and inflammation mitigation. Deep sequencing showed a panel of mutations potentially associated with the enhanced infection in aged BALB/c mice, such as the Q498H mutations which are located at the receptor binding domain (RBD) of the spike (S) protein. We further found that the isolates can not only multiply in the respiratory tract of mice but also cause disease in aged mice. Overall, viral replication and rapid adaption in aged BALB/c mice were associated with pneumonia, confirming that the age-related susceptibility to SARS-CoV-2 in mice resembled that in humans.ImportanceAged BALB/c model are in use as a model of disease caused by SARS-CoV-2. Our research demonstrated SARS-CoV-2 can rapidly adapt in aged BALB/c mice through causing mutations at the RBD of the S protein. Moreover, SARS-CoV-2-infected aged BALB/c mice indicated that alveolar damage, interstitial pneumonia, and inflammatory immune responses were similar to the clinical manifestations of human infections. Therefore, our aged BALB/c challenge model will be useful for further understanding the pathogenesis of SARS-CoV-2 and for testing vaccines and antiviral agents.

12.
Oral Dis ; 27(7): 1667-1677, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33125794

RESUMO

OBJECTIVE: This study was aimed to analyze the role of T-cell immunoreceptor with immunoglobulin and tyrosine-based inhibitory motif domains (TIGIT) expression on T cells in patients with oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMC) and tumor-infiltrating lymphocytes (TILs) were collected from OSCC patients. The correlation between TIGIT expression and clinicopathologic features was analyzed by chi-square test. Phenotypic and functional study of TIGIT+ T cells were performed by flow cytometry. RESULTS: TIGIT was highly expressed on T cells from PBMC and TILs. High expression of TIGIT on CD4+ T cells (19.0%) and CD8+ T cells (35.9%) was also associated with higher T stage and nodal invasion. Moreover, TIGIT+ CD4+ and TIGIT+ CD8+ T cells sorted from OSCC patients showed a dysfunctional phenotype (low cell proliferation and low secretion of IL-2, TNF-α and IFN-γ), and TIGIT+ CD4+ T cells exhibited inhibitory function (high expression of Foxp3 and high amounts of IL-10). Importantly, TIGIT blockade can enhance the proliferation ability and effective cytokine production (IL-2, TNF-α, and IFN-γ) of CD4+ and CD8+ T cells from OSCC patients in vitro. CONCLUSIONS: TIGIT-expressing T cells exhibit a lower effector cytokine-releasing phenotype in OSCC patients.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Linfócitos T CD8-Positivos , Humanos , Leucócitos Mononucleares , Receptores Imunológicos , Carcinoma de Células Escamosas de Cabeça e Pescoço
13.
J Environ Manage ; 269: 110828, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32561020

RESUMO

There are nearly two million ha of red jujube in the arid inland agricultural region south of the Tianshan mountains in China that produce approximately 37.2% of the global red jujube market. This paper provides an insight into the spatiotemporal variation of the water footprint and economic water productivity of red jujube cultivation in six main red jujube-producing areas. The effects of regional policies, industrial clusters, planting structures, irrigation methods and brand values studied extensively in this paper and shows how these driving factors affect the variation. Time series data covering the period of 2003-2015 was used for the study. The results showed that the annual variation of yield, cultivated areas, water footprint and economic water productivity of red jujube cultivation have experienced upward trends in the Tianshan regions, but that there were also few differences between different growing areas. The blue water makes the largest contribution (more than 70%) to the components of the red jujube water footprint in each red jujube producing area. The contribution of grey water footprint to the total consumptive WF was quite small (less than 10%) and the remaining 10%-15% was due to the green water. The water footprint and overall economic water productivity through the red jujube in various producing areas are affected by local government management and performance. The possible ways of improving economic water productivity in terms of red jujube cultivation are through policy, technological and management interventions.


Assuntos
Água , Ziziphus , Agricultura , China , Políticas
14.
Sci Rep ; 10(1): 2662, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-32060343

RESUMO

In the last few years, V-domain Ig-containing suppressor of T cell activation(VISTA) has been reported as a prognostic biomarker in articles including various solid tumours. However, their conclusions have been controversial. For this reason, we performed this meta-analysis to further verify the prognostic value of VISTA in solid tumours. All relevant literature was identified from PubMed, Embase, the Cochrane Library and Web of Science. Ten studies, including 2, 440 patients, were eligible for the analysis. The pooled results showed that high expression of VISTA was associated with favourable overall survival (OS) than that seen with low expression of VISTA (7 studies, hazard ratio (HR) = 0.75, 95% confidence interval (CI): 0.66-0.86, P < 0.001). In addition, high expression of VISTA significantly correlated with high numbers of CD8 (+) tumour infiltrating lymphocytes (TILs) (3 studies, risk ratio (RR) = 1.80, 95% CI: 1.41-2.31, P < 0.001). In conclusion, these results indicate that VISTA is a potential prognostic biomarker in solid tumours.


Assuntos
Antígenos B7/metabolismo , Neoplasias/diagnóstico , Neoplasias/metabolismo , Linfócitos T CD8-Positivos/imunologia , Intervalo Livre de Doença , Feminino , Humanos , Contagem de Linfócitos , Linfócitos do Interstício Tumoral/imunologia , Masculino , Neoplasias/imunologia , Prognóstico , Viés de Publicação
15.
Sci Total Environ ; 707: 135587, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-31784147

RESUMO

Mulch drip irrigation is widely used in the arid areas of Northwest China. Consequently, the Manas River Basin has developed into the fourth largest irrigated agricultural area in China. In this study, a groundwater model of the regional water cycle was developed to quantitatively assess the groundwater balance in response to different irrigation schemes, including traditional irrigation, conventional water-saving irrigation, and high-efficiency water-saving irrigation schemes. Our results reveal that 1) The water-saving irrigation technology has affected the water cycle process in farmlands. The higher the degree of water conservation, the lower the infiltration into groundwater, the higher the deficit of the groundwater balance, and the more significant the decline of the groundwater level. 2) The groundwater at the Manas River Basin remains in a negative equilibrium state. To achieve an equilibrium state of the groundwater at the Manas River Basin, the catchment management agencies should restrict the scale of oasis development and the utilization of groundwater.

16.
Artigo em Inglês | MEDLINE | ID: mdl-31590212

RESUMO

A longevity area in Xinjiang, China and an adjacent non-longevity area both have similar climatic and hydrogeological conditions, and the residents of the two control groups have similar ethnic composition, diets and lifestyles. This study investigated if differences in groundwater quality between the longevity area and the non-longevity area are associated with the health of residents in the two control groups. In order to quantitatively describe the groundwater quality of the two control groups and its influence on human health, the Fuzzy Comprehensive Evaluation Method (FCEM) was used to compare and assess the overall water environment of the two control groups. Furthermore, the human health risk of groundwater for the two control groups was assessed using the Health Risk Assessment Model recommended by the U.S. Environmental Protection Agency (USEPA). Results showed that the overall water environment categories for the longevity area and non-longevity area are moderate quality (grade III) and very poor quality (grade V), respectively. The main health risk in the longevity area water environment is the non-carcinogenic risk (HQLLV) caused by Cl-. The main health risks in the non-longevity area water environment are the non-carcinogenic risk (HQCA) caused by Cl- and the carcinogenic risk (RiskCA) caused by As. The total health risk (HRall) caused by over-standard inorganic pollutants in the water environment of the non-longevity area is 3.49 times higher than that of the longevity area. In addition, the study showed that the water environment pollution downstream of the Keriya River is conjunctively caused by agricultural activities and domestic sewage. The overall water environment of the longevity area is more conducive to the health-longevity of residents than the non-longevity area.


Assuntos
Monitoramento Ambiental/métodos , Longevidade , Medição de Risco , Poluentes Químicos da Água/toxicidade , Qualidade da Água , Agricultura , China , Água Subterrânea/análise , Humanos , Rios , Poluentes Químicos da Água/análise
17.
Sci Total Environ ; 691: 506-515, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325851

RESUMO

Modern water-saving irrigation technology has expanded the scale of agricultural oases in arid and semi-arid regions of China. In this study, we used Landsat MSS and Landsat TM/ETM remote sensing data to assess changes in oasis scale and water availability with reference to differing water management practices in the Manas River Basin of north-western China from 1975 to 2015. We used the water-heat balance index H0 to determine oasis stability over time and constructed a suitable-scale calculation model for arid and semi-arid regions to assess the suitable development scale and cultivated land area in the study area. The implementation of water-saving technology in 2000 effectively improved the utilization efficiency of water resources and accelerated the formation of artificial oases; these expanded by 3873.3 km2 while natural oasis area was reduced by 3485.0 km2. The oasis stability index H0 was less than the critical stability index of 0.5 throughout the study period, implying that these areas were in a metastable state and unsuitable for further development. Therefore, in order to improve oasis stability, both scale and agricultural area should be further controlled. At present, actual oasis scale exceeds appropriate scale by 1.1 times and agricultural area exceeds suitable area by 2.5 times. To ensure the stability of the oasis, its area should be maintained at 3942.28-4481.06 km2 and the cultivated land should be maintained at 1576.91-1792.42 km2.

18.
Environ Technol ; 40(23): 3105-3113, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29668358

RESUMO

The long-term and short-term effects of salinity on the multivalent metal ions within extracellular polymeric substance (EPS) were investigated in this study. The results indicated that the Na+ content within the EPS increased significantly from 19.53% to 60.86% under high salinity, and this content in the saline system was 2.2 times higher than that of the control system at the end of the operation. The K+, Ca2+ and Mg2+ contents within the EPS decreased from 33.85%, 39.19% and 5.54% to 7.07%, 25.64% and 3.28%, respectively, when the salinity was increased from 0 g/L to 30 g/L. These ions were replaced by Na+ through ion exchange and competing ionic binding sites under salt stress. The interaction between divalent metal ions and Na+ was reversible with the adaption of anammox to salinity. Salinity exhibited a limited influence on the Fe3+ within the EPS. Sludge granulation was inhibited under conditions of high salinity due to the replacement of multivalent metal ions by Na+.


Assuntos
Reatores Biológicos , Esgotos , Matriz Extracelular de Substâncias Poliméricas , Íons , Metais , Sódio
19.
Chemosphere ; 213: 377-383, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30241082

RESUMO

In order to solve the problem of slag recycling and dyeing wastewater treatment synchronously, the slag particles is used as raw material to prepare the particle electrodes, and the optimum preparation conditions of the slag particle electrodes is obtained through orthogonal test. Scanning electron microscopy, X-ray diffractometer and micro-hole physics and chemical adsorption analyzer are used to characterize and analyze the surface morphology, crystal structure, specific surface area and pore shape of the particle electrode. The operating parameters of the reaction system are optimized, and the energy consumption per order is calculated in optimized experimental conditions. The radical scavenging mechanism of three free radical scavengers (methanol, tert-butanol, and phenol) is studied, and the type of the main active substance participating in degradation of Methylene blue and the location of the degradation reaction are determined. It is speculated that the degradation reaction of Methylene blue occurs in the boundary layer on the external surface of the particle electrodes, not in the aqueous solution.


Assuntos
Eletrodos , Azul de Metileno/química , Águas Residuárias/química , Adsorção , Precipitação Química
20.
Sci Rep ; 8(1): 452, 2018 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-29323209

RESUMO

Understanding the mechanism of complicated hydrological processes is important for sustainable management of water resources in an arid area. This paper carried out the simulations of water movement for the Manas River Basin (MRB) using the improved semi-distributed Topographic hydrologic model (TOPMODEL) with a snowmelt model and topographic index algorithm. A new algorithm is proposed to calculate the curve of topographic index using internal tangent circle on a conical surface. Based on the traditional model, the improved indicator of temperature considered solar radiation is used to calculate the amount of snowmelt. The uncertainty of parameters for the TOPMODEL model was analyzed using the generalized likelihood uncertainty estimation (GLUE) method. The proposed model shows that the distribution of the topographic index is concentrated in high mountains, and the accuracy of runoff simulation has certain enhancement by considering radiation. Our results revealed that the performance of the improved TOPMODEL is acceptable and comparable to runoff simulation in the MRB. The uncertainty of the simulations resulted from the parameters and structures of model, climatic and anthropogenic factors. This study is expected to serve as a valuable complement for widely application of TOPMODEL and identify the mechanism of hydrological processes in arid area.

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