Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
Environ Sci Technol ; 58(37): 16399-16409, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39235209

RESUMEN

The cyclical variations in environmental temperature generated by natural rhythms constantly impact the wastewater treatment process through the aeration system. Engineering data show that fluctuations in environmental temperature cause the reactor temperature to drop at night, resulting in increased dissolved oxygen concentration and improved effluent wastewater quality. However, the impact of natural temperature variation on wastewater treatment systems and the energy-saving potential has yet to be fully recognized. Here, we conducted a comprehensive study, using a full-scale oxic-hydrolytic and denitrification-oxic (OHO) coking wastewater treatment process as a case and developed a dynamic aeration model integrating thermodynamics and kinetics to elucidate the energy-saving mechanisms of wastewater treatment systems in response to diurnal temperature variations. Our case study results indicate that natural diurnal temperature variations can cut the energy consumption of 660,980 kWh annually (up to 30%) for the aeration unit in the OHO system. Wastewater treatment facilities located in regions with significant environmental temperature variation stand to benefit more from this energy-saving mechanism. Methods such as flow dynamic control, load shifting, and process unit editing can be fitted into the new or retrofitted wastewater treatment engineering.


Asunto(s)
Temperatura , Eliminación de Residuos Líquidos , Aguas Residuales , Aguas Residuales/química , Coque , Purificación del Agua
2.
Front Psychol ; 15: 1387983, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39086428

RESUMEN

Background: The long-term impact of COVID-19 on the mental health and well-being of college students, specifically trends over time after full removal of COVID-19 restrictions, has not been well-studied. Methods: Four consecutive cross-sectional surveys were conducted in December 2022 (N = 689), March 2023 (N = 456), June 2023 (N = 300), and November 2023 (N = 601) at a university in Sichuan Province, China. Results: The proportion of students with COVID-19 panic decreased from 95.1 to 77.3% (p < 0.001). The prevalence of moderate anxiety and above decreased from 18 to 13.6% (p < 0.001), and the prevalence of moderate and above depression decreased from 33.1 to 28.1% (p < 0.001), while the prevalence of post-traumatic stress disorder (PTSD) increased from 21.5 to 29.6% (p < 0.005). Further, the proportion of suicidal thoughts increased from 7.7 to 14.8% (p < 0.001). Suicidal thoughts and self-injuries were significantly associated with COVID-19 panic, depression, anxiety, and PTSD. Students who reported being in close contact with COVID-19 patients in the past were more likely to develop PTSD. Further, COVID-19-induced panic was a risk factor for self-injury. Conclusion: One year after the COVID-19 pandemic, the overall mental health of college students was not optimal. Hence, we can conclude that the long-term impacts of COVID-19 on the mental health of college students may have already occurred. To mitigate this impact and prepare for the next major public health event, strengthening college students' mental health curricula and promoting healthy behaviors among college students should be a priority for universities and education authorities.

3.
J Ultrasound Med ; 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39136224

RESUMEN

OBJECTIVE: This study aimed to assess the use of two-dimensional (2D) ultrasound combined with high-definition flow (HD-flow) render mode and spatiotemporal image correlation (STIC) in diagnosing and classifying fetal persistent left superior vena cava (PLSVC). METHODS: Overall, 114 cases of fetal PLSVC were diagnosed using 2D ultrasound combined with STIC, and 114 normal fetuses of the same gestational week were selected. These cases were retrospectively analyzed to evaluate the effectiveness of the diagnostic approach. RESULTS: All 114 PLSVC cases were diagnosed using 2D ultrasound combined with STIC. Although the diagnostic coincidence rate of PLSVC in the HD-flow combined with STIC was similar to that in the 2D ultrasound combined with HD-flow (96.8 vs 96.2%), 2D ultrasound with STIC enabled dynamic visualization of the PLSVC, furthering prenatal diagnosis. These cases were classified as type I PLSVC: 80 cases of type Ia, 29 cases of type Ib, and 5 cases of type Ic. Seventy isolated PLSVC cases (61.4%) were noted, whereas 44 cases (35.6%) were associated with concomitant structural abnormalities. Intracardiac structural malformations accounted for the highest proportion (n = 53, 58.89%), followed by single umbilical artery and facial/bodily abnormalities (n = 10, 11.11%). CONCLUSION: Combining HD-flow and STIC complements 2D ultrasound in diagnosing and classifying fetal PLSVC, demonstrating significant clinical relevance.

4.
Ecol Evol ; 14(5): e11346, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38716168

RESUMEN

Numerous dams disrupt freshwater animals. The uppermost population of the critically endangered Yangtze finless porpoise has been newly formed below the Gezhouba Dam, however, information regarding the local porpoise is scarce. Passive acoustic monitoring was used to detect the behaviors of porpoises below the Gezhouba Dam. The influence of shipping, pandemic lockdown, hydrological regime, and light intensity on the biosonar activity of dolphins was also examined using Generalized linear models. Over the course of 4 years (2019-2022), approximately 848, 596, and 676 effective monitoring days were investigated at the three sites, from upstream to downstream. Observations revealed significant spatio-temporal biosonar activity. Proportion of days that are porpoise positive were 73%, 54%, and 61%, while porpoise buzz signals accounted for 78.49%, 62.35%, and 81.30% of all porpoise biosonar at the three stations. The biosonar activity of porpoises was much higher at the confluence area, particularly at the MZ site, during the absence of boat traffic, and during the Pandemic shutdown. Temporal trends of monthly, seasonal, and yearly variation were also visible, with the highest number of porpoises biosonar detected in the summer season and in 2020. Significant correlations also exist between the hydrological regime and light intensity and porpoise activity, with much higher detections during nighttime and full moon periods. Hydropower cascade development, establishment of a natural reserve, fish release initiatives, and implementation of fishing restrictions may facilitate the proliferation of the porpoise population downstream of the Gezhouba Dam within the Yichang section of the Yangtze River. Prioritizing restoration designs that match natural flow regimes, optimize boat traffic, and reduce noise pollution is crucial for promoting the conservation of the local porpoises.

5.
Ecol Evol ; 14(4): e11247, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38584767

RESUMEN

Wuhan, a highly urbanized and rapidly growing region within China's Yangtze Economic Zone, has historically been identified as a gap area for the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) based on daytime visual surveys. However, there has been a noticeable increase in porpoise sightings since 2020. This study employed passive acoustic monitoring to investigate porpoise distribution in Wuhan between 2020 and 2022. Generalized linear models were used to explore the relationship between shipping, hydrological patterns, light intensity, and porpoise biosonar activity. Over 603 days of effective monitoring, the daily positive rate for porpoise biosonar detection reached 43%, with feeding-related buzz signals accounting for 55% of all porpoise biosonar signals. However, the proportion of minutes during which porpoise presence was detected was 0.18%, suggesting that while porpoises may frequent the area, their visits were brief and mainly focused on feeding. A significant temporal trend emerged, showing higher porpoise biosonar detection during winter (especially in February) and 2022. Additionally, periods without boat traffic correlated with increased porpoise activity. Hydrological conditions and light levels exhibited significant negative correlations with porpoise activity. Specifically, porpoise sonar detections were notably higher during the night, twilight, and new moon phases. It is highly conceivable that both fishing bans and COVID-19 pandemic-related lockdowns contributed to the heightened presence of porpoises in Wuhan. The rapid development of municipal transportation and shipping in Wuhan and resulting underwater noise pollution have emerged as a significant threat to the local porpoise population. Accordingly, it is imperative for regulatory bodies to effectively address this environmental stressor and formulate targeted protection measures to ensure the conservation of the finless porpoise.

6.
Zool Res ; 44(5): 919-931, 2023 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-37642009

RESUMEN

Under increasing anthropogenic pressure, species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations. The critically endangered Yangtze finless porpoise ( Neophocaena asiaeorientalis asiaeorientalis), once commonly observed in the Yangtze River-Poyang Lake junction, is now rarely seen in the river-lake corridor. In this study, static passive acoustic monitoring techniques were used to detect the biosonar activities of the Yangtze finless porpoise in this unique corridor. Generalized linear models were used to examine the correlation between these activities and anthropogenic impacts from the COVID-19 pandemic lockdown and boat navigation, as well as environmental variables, including hydrological conditions and light levels. Over approximately three consecutive years of monitoring (2020-2022), porpoise biosonar was detected during 93% of logged days, indicating the key role of the corridor for finless porpoise conservation. In addition, porpoise clicks were recorded in 3.80% of minutes, while feeding correlated buzzes were detected in 1.23% of minutes, suggesting the potential existence of localized, small-scale migration. Furthermore, both anthropogenic and environmental variables were significantly correlated with the diel, lunar, monthly, seasonal, and annual variations in porpoise biosonar activities. During the pandemic lockdown period, porpoise sonar detection showed a significant increase. Furthermore, a significant negative correlation was identified between the detection of porpoise click trains and buzzes and boat traffic intensity. In addition to water level and flux, daylight and moonlight exhibited significant correlations with porpoise biosonar activities, with markedly higher detections at night and quarter moon periods. Ensuring the spatiotemporal reduction of anthropogenic activities, implementing vessel speed restrictions (e.g., during porpoise migration and feeding), and maintaining local natural hydrological regimes are critical factors for sustaining porpoise population viability.


Asunto(s)
COVID-19 , Marsopas , Animales , Efectos Antropogénicos , COVID-19/epidemiología , COVID-19/veterinaria , Control de Enfermedades Transmisibles , Lagos , Pandemias , Ríos , China
7.
BMJ Glob Health ; 8(4)2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37041021

RESUMEN

OBJECTIVE: This study aimed to investigate the preferences regarding risks, benefits and other treatment attributes of patients with type 2 diabetes mellitus (T2DM) in China when selecting a second-line anti-hyperglycaemic medicine. METHODS: A discrete choice experiment with hypothetical anti-hyperglycaemic medication profiles was performed using a face-to-face survey administered to patients with T2DM. The medication profile was described using seven attributes: treatment efficacy, hypoglycaemia risk, cardiovascular benefits, gastrointestinal (GI) adverse events, weight change, mode of administration and out-of-pocket cost. Participants chose between medication profiles by comparing attributes. Data were analysed using a mixed logit model with marginal willingness to pay (mWTP) and maximum acceptable risk (MAR) calculated. The preference heterogeneity within the sample was explored using a latent class model (LCM). RESULTS: A total of 3327 respondents from five major geographical regions completed the survey. Treatment efficacy, hypoglycaemia risk, cardiovascular benefits and GI adverse events were major concerns among the seven attributes measured. Weight change and mode of administration were of lesser concern. Regarding mWTP, respondents would pay ¥236.1 (US$36.6) for an anti-hyperglycaemic medication with an efficacy of 2.5% points reduction in HbA1c, while they were willing to accept a weight gain of 3 kg only if they received a compensation of ¥56.7 (US$8.8). Respondents were willing to accept a relatively large increase in hypoglycaemia risk (MAR=15.9%) to improve treatment efficacy from intermediate (1.0% points) to high (1.5% points). LCM identified the following four unobserved subgroups: trypanophobia, cardiovascular-benefits-focused, safety-focused and efficacy-focused and cost-sensitive. CONCLUSION: Patients with T2DM prioritised free out-of-pocket costs, highest efficacy, no hypoglycaemia risk and cardiovascular benefits over weight change and mode of administration. There exists great preference heterogeneity among patients, which should be taken into account in healthcare decision-making processes.


Asunto(s)
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/inducido químicamente , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Conducta de Elección , Prioridad del Paciente , Encuestas y Cuestionarios , Hipoglucemiantes/efectos adversos
8.
Chemosphere ; 329: 138660, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37044138

RESUMEN

Hydraulic retention time (HRT), as an important parameter in the wastewater treatment process, has a great impact on water quality and energy consumption. With the rapid advances in computer technology and deepened understanding of in microbial metabolism, a series of activated sludge models (ASMs) have been developed and applied in wastewater treatment. However, ASMs simulation based on the nexus of HRT, water treatment process, water quality and energy consumption has yet to be verified. In this study, HRT was creatively linked to water treatment process variation. And a novel combined process model (CPM) was developed based on the operational data and treatment performance data from 4 full-scale coking wastewater treatment processes. In the CPM, an array of biological treatment processes were represented by setting the HRT in respective treatment units of the anaerobic-oxic-hydrolytic & denitrification-oxic (A/O/H/O) process. The relationships between HRT, effluent quality and energy consumption were systematically analyzed. Results showed that: (i) for A/O/H/O process, the HRT of first oxic (O1) reactor has a key effect on the effluent water quality and energy consumption, while the impact of the anaerobic (A) reactor HRT was limited; (ii) the O/H/O process has a clear advantage in treating coking wastewater due to the carbon removal and detoxification function of O1 reactor; (iii) the lowest energy consumption (with the total system HRT below 210 h) to meet the biological effluent quality requirements (COD = 200 mg/L, TN = 50 mg/L) is 4.429 kWh/m3. Since the CPM could effectively work out the optimal process configuration and break the boundaries between HRT and process variation, it has enormous potential to be extended to the design of other wastewater treatment processes.


Asunto(s)
Coque , Purificación del Agua , Eliminación de Residuos Líquidos/métodos , Reactores Biológicos , Aguas Residuales , Aguas del Alcantarillado , Anaerobiosis
9.
Sci Total Environ ; 881: 163384, 2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37044344

RESUMEN

Due to the phosphorus (P) deficiency in coking wastewater, sufficient P needs to be provided in the treatment process to maintain biotic activity. However, most of the dosed P sources are transferred to the sludge phase out of the chemical equilibrium. After an in-depth investigation of P morphology changes in coking wastewater treatment, it is found that above 71.6 % P applied to the full-scale O/H/H/O (oxic-hydrolytic & denitrification-hydrolytic & denitrification-oxic) process for coking wastewater treatment is ended up in the sludge phase of the aerobic reactors in the forms of non-apatite inorganic phosphorus (NAIP). Theoretical simulations suggest that the P forms precipitates such as FePO4·2H2O, AlPO4·2H2O, MnHPO4 at pH < 7, and Ca5(PO4)3OH at pH > 7. Microbial utilization of P in coking wastewater treatment is swayed by precipitation, pH and sludge retention time (SRT). By pyrolysis treatment of the waste sludge at 700 °C, phosphoric substances in coking sludge are enriched and converted into Ca5(PO4)3OH, Ca5(PO4)3Cl, Ca3(PO4)2, etc. with apatite phosphorus (AP) accounting for 65.7 % of total phosphorus. Moreover, the heavy metals in biochar were below the national standard limits for discharge. This study shows that hazardous waste (coking sludge) can be transformed into bioavailable products (P-rich biochar) through comprehensive management of the fate of P. Combined with the O/H/H/O process, the mechanisms of phosphorus consumption in coking wastewater treatment are revealed for the first time, which will facilitate a reduced consumption of phosphorus and provide a demonstration for other phosphorus-deficient industrial wastewater treatment.


Asunto(s)
Coque , Aguas Residuales , Aguas del Alcantarillado/química , Fósforo/química
10.
Front Immunol ; 14: 1028404, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36817485

RESUMEN

Objective: To identify the gene subtypes related to immune cells of cholangiocarcinoma and construct an immune score model to predict the immunotherapy efficacy and prognosis for cholangiocarcinoma. Methods: Based on principal component analysis (PCA) algorithm, The Cancer Genome Atlas (TCGA)-cholangiocarcinoma, GSE107943 and E-MTAB-6389 datasets were combined as Joint data. Immune genes were downloaded from ImmPort. Univariate Cox survival analysis filtered prognostically associated immune genes, which would identify immune-related subtypes of cholangiocarcinoma. Least absolute shrinkage and selection operator (LASSO) further screened immune genes with prognosis values, and tumor immune score was calculated for patients with cholangiocarcinoma after the combination of the three datasets. Kaplan-Meier curve analysis determined the optimal cut-off value, which was applied for dividing cholangiocarcinoma patients into low and high immune score group. To explore the differences in tumor microenvironment and immunotherapy between immune cell-related subtypes and immune score groups of cholangiocarcinoma. Results: 34 prognostic immune genes and three immunocell-related subtypes with statistically significant prognosis (IC1, IC2 and IC3) were identified. Among them, IC1 and IC3 showed higher immune cell infiltration, and IC3 may be more suitable for immunotherapy and chemotherapy. 10 immune genes with prognostic significance were screened by LASSO regression analysis, and a tumor immune score model was constructed. Kaplan-Meier (KM) and receiver operating characteristic (ROC) analysis showed that RiskScore had excellent prognostic prediction ability. Immunohistochemical analysis showed that 6 gene (NLRX1, AKT1, CSRP1, LEP, MUC4 and SEMA4B) of 10 genes were abnormal expressions between cancer and paracancer tissue. Immune cells infiltration in high immune score group was generally increased, and it was more suitable for chemotherapy. In GSE112366-Crohn's disease dataset, 6 of 10 immune genes had expression differences between Crohn's disease and healthy control. The area under ROC obtained 0.671 based on 10-immune gene signature. Moreover, the model had a sound performance in Crohn's disease. Conclusion: The prediction of tumor immune score model in predicting immune microenvironment, immunotherapy and chemotherapy in patients with cholangiocarcinoma has shown its potential for indicating the effect of immunotherapy on patients with cholangiocarcinoma.


Asunto(s)
Neoplasias de los Conductos Biliares , Colangiocarcinoma , Enfermedad de Crohn , Humanos , Pronóstico , Conductos Biliares Intrahepáticos , Microambiente Tumoral , Proteínas Mitocondriales
11.
J Hazard Mater ; 447: 130802, 2023 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-36669414

RESUMEN

In this study, physicochemical pre- and post-treatment of highly polluting coking wastewater (CWW) for the removal of refractory compounds and recovery of high-energy substances/components was investigated. An economic optimization model targeting the development of a cost-effective and sustainable treatment technology was proposed. At the post-treatment stage, powdered activated carbon (PAC) was used to separate the refractory and toxic pollutants from the bio-treated CWW, with the adsorption capacity ranging from 50 to 120 mg chemical oxygen demand (COD) g-1 PAC. Then, the spent PAC, together with a coagulant, was reused in the pre-treatment of highly concentrated raw CWW, which lifted the adsorption capacity to 800-1200 mg COD g-1 PAC. Results showed that the adsorbent's high selectivity towards macromolecular and complicated pollutants could remove 25-65 % of COD in both CWW flows. Analysis of pollutants' molecular weight distribution and GC-MS indicated a good affinity between PAC and high-energy pollutants (phenolic compounds and alkanes), which could transfer 144,555 kJ m-3 of energy from CWW to the adsorption-coagulation sludge. The economic optimization model suggested that the cost of the adsorbent was compensated by the net benefits of energy recovery and that profit was achieved when the PAC price was less than 5562 CNY t-1. The proposed two-stage PAC/coagulant approach offers a way to sustainable water quality and sludge management, plus energy recycling, in CWW treatment. It may also be applied to the treatment of other industrial wastewaters.

12.
J Appl Biomech ; 38(6): 404-411, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36370702

RESUMEN

The purpose of this study was to determine shoulder joint reaction forces and muscle moments during 2 speeds (1.3 and 2.2 m/s) of wheelchair propulsion and to investigate the relationship between joints reaction forces, muscle moments, and shoulder pain. The measurements were obtained from 20 manual wheelchair users. A JR3 6-channel load sensor (±1% error) and a Qualisys system were used to record 3-dimensional pushrim kinetics and kinematics. A 3-dimensional inverse dynamic model was generated to compute joint kinetics. The results demonstrated significant differences in shoulder joint forces and moments (P < .01) between the 2 speeds of wheelchair propulsion. The greatest peak shoulder joint forces during the drive phase were anterior directed (Fy, 184.69 N), and the greatest joint moment was the shoulder flexion direction (flexion moment, 35.79 N·m) at 2.2 m/s. All the shoulder joint reaction forces and flexion moment were significantly (P < .05) related to shoulder pain index. The forces combined in superior and anterior direction found at the shoulder joint may contribute to the compression of subacromial structure and predispose manual wheelchair users to potential rotator cuff impingement syndrome.


Asunto(s)
Articulación del Hombro , Silla de Ruedas , Humanos , Dolor de Hombro , Hombro , Articulación del Hombro/fisiología , Fenómenos Biomecánicos , Músculos
13.
Front Aging Neurosci ; 14: 935986, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35928991

RESUMEN

The purposes of this perspective article were to summarize Wheelchair or Seated Tai Chi studies related to neuromuscular functions of older adults with disability; to describe the development of Wheelchair Tai Chi Ball (WTCB) exercise - a concept to combine mind-body exercise with strength training; and to propose a new Telehealth WTCB exercise for improving neuromuscular functions of old adults with spinal cord injury (SCI) and disability. With reference to neuromuscular functions, WTC intervention may have positive effects on simple reaction time, range of motion at the shoulder and trunk, static and dynamic sitting balance, handgrip strength, vagal activity, and sympathetic activity among older adults with disability. The developed WTCB intervention is a feasible and safe exercise which combines the mind-body exercise and strength conditioning into one exercise which possesses aerobic, stretching and strength trainings and may facilitate neuromuscular functions of older adults with disability. The proposed Telehealth WTCB 12 forms (TWTCB12) exercise with a "Moving Shadow" method in the telehealth may enable the learner to superimpose learner's image on an expert's demonstrating model to enhance the learning and practice effects. Since wheelchair users will learn and practice TWTCB12 movements in a seated position or sitting on a wheelchair the "Moving shadow" method on Zoom would provide an ideal telehealth learning and practice environment for the wheelchair users to learn and practice TWTCB12 exercise from home more feasible and user friendly.

14.
Chin Med Sci J ; 37(2): 164-166, 2022 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-35796341

RESUMEN

Mandibular buccal bifurcation cyst is a rare inflammatory odontogenic cyst. We reported two cases who complained of painful swelling of extraoral soft tissue. Intraoral examination revealed the partially erupted mandibular first molar. Cone beam computed tomography showed a well-defined cystic lesion surrounding the first molar. Histopathologic images showed the cyst wall was infiltrated by a large number of plasma cells, neutrophils and eosinophils, and lined with a thin layer of non-keratinized stratified squamous epithelium. Finally, the two patients were diagnosed as mandibular buccal bifurcation cyst and treated with cyst enucleation and curettage.


Asunto(s)
Enfermedades Mandibulares , Quistes Odontogénicos , Quiste Periodontal , Humanos , Recuento de Leucocitos , Enfermedades Mandibulares/diagnóstico por imagen , Enfermedades Mandibulares/patología , Enfermedades Mandibulares/cirugía , Diente Molar/patología , Quistes Odontogénicos/diagnóstico por imagen , Quistes Odontogénicos/cirugía , Quiste Periodontal/patología
15.
J Hazard Mater ; 437: 129267, 2022 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-35716572

RESUMEN

Systematically analyzing the problem of heavy metals in the municipal sludge, a meta-analysis of nine metals was undertaken to distinguish the sources and sinks of those with the impact of their accumulation on the environment. Municipal sludge was rich in N, P and K nutrients, was found to contain heavy metals comprising the descending order Zn > Mn > Cu > Cr > Pb > Ni > As > Cd > Hg. The forms, in which heavy metals accumulated in geographical regions, were characterized. The geographical distribution of heavy metals in the sludge showed a significant difference, with higher accumulation in Eastern and Southern regions, however, the risk evaluations showed the higher risk of heavy metals accumulation in Eastern and Western regions. Agricultural, industrial and traffic activities, and storm water pipeline sediments were identified as the main sources of heavy metals in the sludge. The correlation analysis elucidated the role of the total organic carbon in the accumulation of heavy metals in sludge. Municipal sludge is endowed with resource properties due to the detection of heavy metal contents thresholds in household products and its own resource-attributable enrichment behavior, which requires deduction of environmental risks.


Asunto(s)
Metales Pesados , Purificación del Agua , China , Monitoreo del Ambiente , Metales Pesados/análisis , Medición de Riesgo , Aguas del Alcantarillado/análisis
16.
Sci Total Environ ; 819: 152006, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-34856253

RESUMEN

The addition of alkaline and magnesium sources during the recovery of NH4+ and PO43- in the form of struvite using the traditional struvite precipitation method increases the production cost. To solve this problem, a magnesium-air cell (MAC) system was used herein to recover NH4+ and PO43- as struvite from wastewater using a magnesium strip (Mg2+) and the oxygen adsorbed on the surface of a titanium plate (OH-) as the anode and cathode, respectively. Experimental parameters (i.e. initial solution pH, temperature, NH4+/PO43- molar ratio, NH4+ and PO43- initial concentrations and stirring intensity) were found to affect the removal rate of NH4+ and PO43-. The presence of Ca2+ decreased the struvite purity. At Ca2+/PO43- ratios of 0:1 and 0.5:1, the purity of the obtained struvite after 6 h was 93.8% and 58.9%, respectively. Struvite with a purity of 95.7%, electricity with an average output power of 2.53 mW, and an energy density of 1.05 W/m2 were obtained when the proposed system was used to recover NH4+ and PO43- from an actual supernatant of domestic sludge anaerobic digestion. Scanning electron microscopy-energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy and thermogravimetric analyses showed that the obtained struvite exhibited almost the same physicochemical properties as commercial struvite. Thus, the MAC system can be regarded as an effective method for recovering NH4+ and PO43- in the form of struvite from wastewater.


Asunto(s)
Compuestos de Amonio , Fosfatos , Precipitación Química , Magnesio/análisis , Nitrógeno/química , Fosfatos/química , Fósforo/química , Estruvita/química
17.
Ecotoxicol Environ Saf ; 228: 113047, 2021 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-34861441

RESUMEN

Highly concentrated live mass stranding events of dolphins and whales happened in the eastern coast of China between June and October 2021. The current study adopted the non-invasive auditory evoked-potential technique to investigate the hearing threshold of a stranded melon headed whale (Peponocephala electra) at a frequency range of between 9.5 and 181 kHz. It was found that, at the frequency range of from 10 to 100 kHz, hearing thresholds for the animal were between 20 and 65 dB higher than those of its phylogenetically closest species (Pygmy killer whale). The severe hearing loss in the melon headed whale was probably caused by transient intense anthropogenic sonar or chronic shipping noise exposures. The hearing loss could have been the cause for the observed temporal and spatial clustered stranding events. Therefore, there is need for noise mitigation strategies to reduce noise exposure levels for marine mammals in the coastal areas of China.

18.
Science ; 374(6573): 1332-1333, 2021 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-34882455
19.
Ecotoxicol Environ Saf ; 226: 112860, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34624534

RESUMEN

The Yangtze River exhibits a high biodiversity and plays an important role in global biodiversity conservation. As the world's busiest inland river in regard to shipping, little attention has been paid to underwater noise pollution. In 2017, the underwater noise level in 25 riverside locations along the middle and lower reaches of the Yangtze River mainly at night time were investigated by using passive acoustic monitoring method. Approximately 88% and 40% of the sampled sites exhibit noise levels exceeding the underwater acoustic thresholds of causing responsiveness and temporary threshold shift, respectively, in cetacean. Noise pollution may impose a high impact on fish with physostomous swim bladders and Weberian ossicles, such as silver carp, bighead carp, goldfish and common carp, whereas it may affect fish with physoclistous swim bladders and without Weberian ossicles, such as lake sturgeon and paddlefish, to a lesser extent. Noise levels reductions of approximately 10 and 20 dB were observed in the middle and lower reaches, respectively, of the Yangtze River over the 2012 level. The green development mode of the ongoing construction of green shipping in the Yangtze River Economic Belt, including the development of green shipping lanes, ports, ships and transportation organizations, may account for the alleviated underwater noise pollution. Follow-up noise mitigation endeavors, such as the extension of ship speed restrictions and the study and implementation of the optimal navigation speed in ecologically important areas, are required to further reduce the noise level in the Yangtze River to protect local porpoises and fish.


Asunto(s)
Carpas , Marsopas , Animales , Biodiversidad , China , Ruido/efectos adversos , Ríos
20.
Medicine (Baltimore) ; 99(51): e22627, 2020 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-33371057

RESUMEN

ABSTRACT: Depression is one of the most common mental health problems in adolescents. The link between negative life events and depression has been well established. However, our understanding about the role of social support in the link, which is likely culture-dependent, is quite limited. This study aimed to determine the mediating effect of social support on the association between life events and depression in adolescents in Chongqing China.A total of 1512 adolescents aged 12 to 17 years old in Chongqing of China were selected using a stratified cluster sampling strategy. Depression symptoms, negative life events, and perceived social support of the participants were measured using the Children's Depression Inventory, Adolescent Life Event Scale, and Child and Adolescent Social Support Scale, respectively. Pearson correlation analyses were performed to detect their associations. A multivariate linear regression model was established to determine the association between life events and depression after adjustment for variations in socio-demographic variables. The mediating effect of social support on the association between negative life events and depression was tested using the structural equation model.About 16.8% of the participants were detected with depression. Depression was associated with negative life events and low levels of social support (P < .05). Both frequency and perceived importance of social support showed a mediating effect on the association between life events and depression.Social support has a mediating effect on the association between life events and depression. Strengthening social support may be considered as an effective interventional strategy on depression in adolescents.


Asunto(s)
Depresión/epidemiología , Acontecimientos que Cambian la Vida , Apoyo Social , Adolescente , Factores de Edad , Niño , China/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Prevalencia , Factores de Riesgo , Factores Sexuales , Factores Socioeconómicos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA