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Characterization of plant growth-promoting traits of Enterobacter sp. and its ability to promote cadmium/lead accumulation in Centella asiatica L 全文
2022
Li, Yi | Mo, Lijuan | Zhou, Xiaoqin | Yao, Yawei | Ma, Jiangming | Liu, Kehui | Yu, Fangming
In the present study, we characterized the plant growth-promoting traits of Enterobacter sp. FM-1 (FM-1) and investigated its ability to promote growth and increase IAA, P, and Fe concentrations as well as Cd and Pb accumulation in Centella asiatica L. (C. asiatica L.) in upstream area (UA) soil and downstream area (DA) soil that we collected from Siding mine. The results demonstrated that FM-1 secreted IAA, produced siderophores, and had P-solubilization ability even under Cd exposure. IAA secretion reached a maximum of 108.3 ± 1.3 mg L⁻¹ under Cd exposure at 25 mg L⁻¹. Siderophore production reached a maximum of 0.94 ± 0.01 under Cd exposure at 50 mg L⁻¹. Pot experiments indicated that FM-1 successfully colonized the roots of C. asiatica L. In both soils, inoculation with FM-1 decreased the pH in rhizosphere soil and increased the bioavailability of both Cd and Pb. In addition, inoculation with FM-1 increased the IAA, P, and Fe concentrations and simultaneously promoted both Cd and Pb accumulation in C. asiatica L. The Cd and Pb concentrations in leaves increased 1.73- and 1.07-fold in the UA soil and 1.25- and 1.11-fold in the DA soil, respectively. Thus, the Cd-resistant strain FM-1 presented excellent PGP traits and could facilitate Cd and Pb phytoremediation by C. asiatica L.
显示更多 [+] 显示较少 [-]Modeling and simulation of single- and double-diode PV solar cell model for renewable energy power solution 全文
2022
Gobichettipalayam Shanmugam, Satheesh Kumar | Sakthivel, Tamil Selvi | Gaftar, Baseera Abdul | Iyyappan, Pradeep | Sathyamurthy, Ravishankar
Nowadays, most of the country switched to generate their power by renewable energy sources as well as the power industries also mainly focused on the renewable resources for power generation. The renewable resources are solar, wind, biomass, and hydroelectric; out of these, the solar market is developing due to shortage of non-renewable resources. The solar energy is freely obtainable during the year; also, it provides a clean and noiseless environment. Most of the large- and small-scale industries and household consumers moved to generate the power through a PV solar cell. Most of the research work includes the modelling of the PV solar cell based on their requirement in a one-diode model. In this article, a detailed study is provided about the circuit-based single-diode solar cell (SCSC) model and double-diode solar cell (DDSC) with different conditions done in MATLAB/Simulink. Both the SDSC and DDSC models are tested with different values of temperature, irradiation, and shunt resistance. This work helps the researchers study V-I and P-V characteristics of the PV solar cell clearly with different conditions. The outputs of SDSC and DDSC models are compared with simulation outputs. Effect of partial shading is also discussed to get a better idea.
显示更多 [+] 显示较少 [-]The costs of “blue sky”: environmental regulation and employee income in China 全文
2022
Xiao, Renrui | Tan, Guangrong | Huang, Baocong | Luo, Yuanyue
Strict environmental regulations may change the behavioral decisions of firms. Based on the exogenous impact of the Chinese Central Government’s inclusion of environmental performance in the assessment targets of municipal officials in 2007, this study uses the difference-in-difference method to explore the impact of environmental regulations on employee income. We find that (1) environmental regulations will significantly reduce the average wage level of employees in polluting industries and have no significant impact in nonpolluting industries. (2) This effect is more pronounced in eastern China, where environmental regulations are more stringent, and in areas where political promotion incentives are stronger. (3) Mechanistic analysis finds that environmental regulations will affect employee income by increasing costs and constraining financing. (4) More importantly, we find that the decline in the average wage level of firms is mainly due to the decline in the average wage level of ordinary employees, and the average wage level of management has not decreased significantly, which means that environmental regulations have expanded the functional income distribution. Our findings contribute to a comprehensive understanding of the effectiveness of environmental regulatory policy implementation and associated economic cost issues.
显示更多 [+] 显示较少 [-]Isolation and screening of sulfur-oxidizing bacteria from coast of Bhavnagar, India, and formulation of consortium for bioremediation 全文
2022
Shinde, Ambika H. | Sharma, A. K. (Ashwini K.) | Doshi, Saksham | Kumar, Madhava Anil | Haldar, Soumya
Reduced sulfur compounds are a nuisance in coastal industries causing heavy economical as well as ecological loss. One such compound, hydrogen sulfide, is proven toxic to aquatic animals as it interferes with their respiration and metabolism as well as overall development, thereby causing direct increase in mortality. Typically, 96-h LC₅₀ values to freshwater and marine fishes are 0-25µM and 525-700µM, respectively. Management of sulfide and other reduced sulfur compounds from aquaculture water and sediment using bioremediating sulfur-oxidizing bacteria as probiotics has attracted attention in recent decades due to its efficiency and minimized environmental effects. In the present study, 201 native and indigenous probiotic candidates were isolated, from various coastal environments. The prospective candidates were screened based on pH reduction and 19 sulfur-oxidizing bacteria were selected and tested for salt tolerance. Further screening was done based on biosafety, ability to produce sulfate by oxidizing thiosulfate, and 16S rRNA–based identification to obtain nine probiotic candidates. Three strains (Enterobacter ludwigii HS1-SOB, Pseudomonas stutzeri B6-SOB, and Cytobacillus firmus C8-SOB) exerting highest sulfate-ion production were selected for formulating a probiotic consortium using mixture design matrix. The optimal composition was determined to be equal ratios of the three isolates that yielded 0.083 mM of sulfate from thiosulfate broth medium at room temperature in 7 days. This is a standalone report of sulfur-oxidizing probiotic consortium composed of the said bacteria. The consortium may be used as a strong tool for remediation of reduced sulfur in aquaculture and associated coastal environments.
显示更多 [+] 显示较少 [-]Spatial and seasonal dynamics of phosphorous and physicochemical variables in the Negro River Estuary (Argentina): a preliminary approach 全文
2022
Perillo, Vanesa L. | Bohn, Vanesa Y. | Menendez, María Clara | Ronda, Ana C. | Vitale, Alejandro J. | Perillo, G. M. E. (Gerardo M. E.) | Piccolo, M Cintia | Cuadrado, Diana G.
Nutrient discharge into rivers and estuaries and the factors that control it need to be further understood to decrease the risk of harmful algae blooms on these ecosystems. Preliminary seasonal physicochemical parameters at six stations along the Negro River Estuary (Argentina) were studied during 2019 (Austral summer, winter, and spring) with high- and low-frequency data. Three of the stations were mainly estuarine-influenced and three were marine-influenced ones. The concentration of phosphate (P), river discharge, meteorological conditions, seasonality, and physicochemical variables were analyzed. Total phosphorus (TP) showed seasonal variations and was higher than previously reported for the upper watershed in all stations in the warmer months, except for the marine control one. Orthophosphate values were also high compared to previous watershed data and changed independently of TP fluctuations. Changing turbidity, water temperature, pH, and conductivity did not appear to have an essential role in phosphorus variations. An unexplained high TP spike in the late spring sample shows the need for further research in the area, while the seawater mixing with P-rich river water could be acting as a dilution agent at the mouth of the river.
显示更多 [+] 显示较少 [-]Development of an exposure protocol for toxicity test (FEET) for a marine species: the European sea bass (Dicentrarchus labrax) 全文
2022
Soloperto, Sofia | Aroua, Salima | Jozet-Alves, Christelle | Minier, Christophe | Halm-Lemeille, Marie-Pierre
Development of an exposure protocol for toxicity test (FEET) for a marine species: the European sea bass (Dicentrarchus labrax) 全文
2022
Soloperto, Sofia | Aroua, Salima | Jozet-Alves, Christelle | Minier, Christophe | Halm-Lemeille, Marie-Pierre
Regulatory assessment of the effects of chemicals requires the availability of validated tests representing different environments and organisms. In this context, developing new tests is particularly needed for marine species from temperate environments. It is also important to evaluate effects that are generally poorly characterized and seldom included in regulatory tests. In this study, we designed an exposure protocol using European sea bass (Dicentrarchus labrax) larvae. We examined classical toxicological values (LCx) as well as behavioral responses. By comparing different hatching and breeding strategies, we defined the optimal conditions of exposure as non-agitated conditions in 24- or 48-well microplates. Our exposure protocol was then tested with 3,4-dichloroaniline (3,4-DCA), a recommended reference molecule. Based on our results, the 96 h LC₅₀ for 3,4-DCA corresponded to 2.04 mg/L while the 168 h LC₅₀ to 0.79 mg/L. Behavioral analyses showed no effect of 3,4-DCA at low concentration (0.25 mg/L). In conclusion, the present work established the basis for a new test which includes behavioral analysis and shows that the use of sea bass is suitable to early-life stage toxicity tests.
显示更多 [+] 显示较少 [-]Development of an exposure protocol for toxicity test (FEET) for a marine species: the European sea bass (Dicentrarchus labrax) 全文
2022
Soloperto, Sofia | Aroua, Salima | Jozet-alves, Christelle | Minier, Christophe | Halm-lemeille, Marie-pierre
Regulatory assessment of the effects of chemicals requires the availability of validated tests representing different environments and organisms. In this context, developing new tests is particularly needed for marine species from temperate environments. It is also important to evaluate effects that are generally poorly characterized and seldom included in regulatory tests. In this study, we designed an exposure protocol using European sea bass (Dicentrarchus labrax) larvae. We examined classical toxicological values (LCx) as well as behavioral responses. By comparing different hatching and breeding strategies, we defined the optimal conditions of exposure as non-agitated conditions in 24- or 48-well microplates. Our exposure protocol was then tested with 3,4-dichloroaniline (3,4-DCA), a recommended reference molecule. Based on our results, the 96 h LC50 for 3,4-DCA corresponded to 2.04 mg/L while the 168 h LC50 to 0.79 mg/L. Behavioral analyses showed no effect of 3,4-DCA at low concentration (0.25 mg/L). In conclusion, the present work established the basis for a new test which includes behavioral analysis and shows that the use of sea bass is suitable to early-life stage toxicity tests.
显示更多 [+] 显示较少 [-]Association between temperature and COVID-19 transmission in 153 countries 全文
2022
Liu, Mengyang | Li, Zhiwei | Liu, Mengmeng | Zhu, Yingxuan | Liu, Yue | Kuetche, Mandela William Nzoyoum | Wang, Jianpeng | Wang, Xiaonan | Liu, Xiangtong | Li, Xia | Wang, Wei | Guo, Xiuhua | Tao, Lixin
The WHO characterized coronavirus disease 2019 (COVID-19) as a global pandemic. The influence of temperature on COVID-19 remains unclear. The objective of this study was to investigate the correlation between temperature and daily newly confirmed COVID-19 cases by different climate regions and temperature levels worldwide. Daily data on average temperature (AT), maximum temperature (MAXT), minimum temperature (MINT), and new COVID-19 cases were collected from 153 countries and 31 provinces of mainland China. We used the spline function method to preliminarily explore the relationship between R₀ and temperature. The generalized additive model (GAM) was used to analyze the association between temperature and daily new cases of COVID-19, and a random effects meta-analysis was conducted to calculate the pooled results in different regions in the second stage. Our findings revealed that temperature was positively related to daily new cases at low temperature but negatively related to daily new cases at high temperature. When the temperature was below the smoothing plot peak, in the temperate zone or at a low temperature level (e.g., <25th percentiles), the RRs were 1.09 (95% CI: 1.04, 1.15), 1.10 (95% CI: 1.05, 1.15), and 1.14 (95% CI: 1.06, 1.23) associated with a 1°C increase in AT, respectively. Whereas temperature was above the smoothing plot peak, in a tropical zone or at a high temperature level (e.g., >75th percentiles), the RRs were 0.79 (95% CI: 0.68, 0.93), 0.60 (95% CI: 0.43, 0.83), and 0.48 (95% CI: 0.28, 0.81) associated with a 1°C increase in AT, respectively. The results were confirmed to be similar regarding MINT, MAXT, and sensitivity analysis. These findings provide preliminary evidence for the prevention and control of COVID-19 in different regions and temperature levels.
显示更多 [+] 显示较少 [-]Risk of thyroid cancer and benign nodules associated with exposure to parabens among Chinese adults in Wuhan, China 全文
2022
Wu, Nan-Xin | Deng, Lang-Jing | Xiong, Feng | Xie, Jin-Ying | Li, Xiao-Jie | Zeng, Qiang | Sun, Jia-Chen | Chen, Da | Yang, Pan
Parabens are widely used as preservatives, which have been found to affect thyroid function in toxicological studies. However, population studies on whether they are associated with thyroid tumors remain unclear. This study aims to investigate the relationship between environmental paraben exposure and thyroid cancer and benign nodules. We recruited participants from the Department of Thyroid and Breast Surgery at Wuhan Central Hospital, Wuhan, China. The detectable percentages of methyl paraben, ethyl paraben, and propyl paraben in the urinary samples of 425 study subjects were 99.1%, 95.3%, and 92.0%, respectively. All uncorrected and creatinine-corrected parabens were moderately correlated with one another. After adjusting for possible confounders, all three parabens were associated with an increased risk of thyroid cancer. Furthermore, the mixture pollutant analysis of parabens found positive associations with risk of thyroid cancer (OR = 0.24, 95% CI: 0.18, 0.31) and benign nodules (OR = 1.33, 95% CI: 0.86, 1.80). We observed that individual exposure to paraben mixtures may be associated with the risk of thyroid cancer and benign nodules.
显示更多 [+] 显示较少 [-]Glutaraldehyde base-cross-linked chitosan-silanol/Fe3O4 composite for removal of heavy metals and bacteria 全文
2022
Liu, Qibo | Wang, Yonghui | Liu, Xueli | Li, Shuang | Ren, shuyue | Gao, Zhixian | Han, Tie | Xu, Zhangrun | Zhou, Huanying
We designed and synthesised a magnetic adsorbent (Fe₃O₄@Si–OH@CS-Glu) combining chitosan-silanol groups with glutaraldehyde as a cross-linking agent, which has improved physicochemical properties and can be used to remove multiple heavy metals and bacteria from polluted water. The adsorbent was characterised with SEM, XRD, FTIR, BET, VSM, and zeta potential. Under optimum conditions, the adsorption efficiencies of Fe₃O₄@Si–OH@CS-Glu for Cr⁶⁺, As⁵⁺, Hg²⁺, and Se⁶⁺ were as high as 90.5%, 73.5%, 91.6%, and 100% respectively. In addition, Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) can be removed after 2–4 adsorption cycles with 2.5 mg Fe₃O₄@Si–OH@CS-Glu. The main adsorption mechanism of the adsorbent for heavy metals and bacteria is electrostatic adsorption. Overall, the synthesised Fe₃O₄@Si–OH@CS-Glu adsorbent showed high removal efficiency and adsorption capacity with a stable structure and easy separation. It has promising applications for the removal of heavy metals and bacteria from water.
显示更多 [+] 显示较少 [-]Critical role of nitric oxide in impeding COVID-19 transmission and prevention: a promising possibility 全文
2022
Rajendran, Rajalakshmi | Chathambath, Anjana | Al-Sehemi, Abdullah G. | Pannipara, Mehboobali | Unnikrishnan, Mazhuvancherry Kesavan | Aleya, Lotfi | Raghavan, Roshni Pushpa | Mathew, Bijo
COVID-19 is a serious respiratory infection caused by a beta-coronavirus that is closely linked to SARS. Hypoxemia is a symptom of infection, which is accompanied by acute respiratory distress syndrome (ARDS). Augmenting supplementary oxygen may not always improve oxygen saturation; reversing hypoxemia in COVID-19 necessitates sophisticated means to promote oxygen transfer from alveoli to blood. Inhaled nitric oxide (iNO) has been shown to inhibit the multiplication of the respiratory coronavirus, a property that distinguishes it from other vasodilators. These findings imply that NO may have a crucial role in the therapy of COVID-19, indicating research into optimal methods to restore pulmonary physiology. According to clinical and experimental data, NO is a selective vasodilator proven to restore oxygenation by helping to normalize shunts and ventilation/perfusion mismatches. This study examines the role of NO in COVID-19 in terms of its specific physiological and biochemical properties, as well as the possibility of using inhaled NO as a standard therapy. We have also discussed how NO could be used to prevent and cure COVID-19, in addition to the limitations of NO.
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