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Investigation and disinfection of bacteria and fungi in sports fitness center 全文
2021
Boonrattanakij, Nonglak | Yomchinda, Sirikorn | Lin, Fang-Jia | Bellotindos, Luzvisminda M. | Lü, Mingjun
This study investigated the air quality improvement in terms of bacterial and fungal contamination in an exercise room of a fitness center under normal operating conditions. Environmental conditions including air conditioning, ventilation, moisture, CO₂, particulate matters, and total number of users were also recorded. In addition, fungal and bacterial load were assessed and disinfection on sports equipment surface was also examined. Background bacteria and fungi densities in bioaerosols were in the range of 249 ± 65 to 812 ± 111 CFU/m³ and 226 ± 39 to 837 ± 838 CFU/m³ in the exercise room of the fitness center and 370 ± 86 to 953 ± 136 CFU/m³ and 465 ± 108 to 1734 ± 580 CFU/m³ in the outdoor air, respectively. Chlorine dioxide and weak acid hypochlorous water aerosols could remove both bacteria and fungi much better than water scrubbing. Contact time of 15 min was sufficient to control both bacteria and fungi to comply with the official air quality standards. User density and carbon dioxide deteriorated both bacteria and fungi disinfection performance whereas temperature was only statistically significant on fungi disinfection. Other factors including relative humidity, airflow velocity, and particulate matters did not have any statistically significant effect on microbial inactivation. Apart from bioaerosol disinfection, inactivation of microorganisms on surfaces of sports equipment was also conducted using chlorine dioxide, zinc oxide, weak acid hypochlorous water, and commercial disinfectant. The surfaces of bicycle handle, dumbbell, and sit-up bench were found to be contaminated with bacteria. Overall bacterial load was 390 to 3720 CFU/cm² with Escherichia coli specifically 550 to 1080 CFU/cm². Chlorine dioxide and zinc oxide were noticeably better than weak acid hypochlorous water and commercial disinfectant in terms of bacteria inactivation whereas all tested disinfectants had comparable effectiveness on E. coli disinfection. Targeted microorganisms on the sports equipment surface were sufficiently inactivated within 2 min after the application of disinfectant.
显示更多 [+] 显示较少 [-]In Situ Investigation of Plastic-Associated Bacterial Communities in a Freshwater Lake of Hungary 全文
2021
Szabó, István | Al-Omari, Jafar | Szerdahelyi, Gábor Soma | Farkas, Milán | Al-Omari, Yazid | Szabó, Péter Márton | Sebők, Rózsa | Griffitts, Jeffrey | Kriszt, Balázs | Szoboszlay, Sándor
Despite the great benefits of plastics in different aspects of life and due to the increase in plastic production and use, plastic wastes are becoming a major environmental concern. It is well known that inappropriate use and disposal lead to the accumulation of plastic litter in different aquatic environments. Microbial biofilm is able to develop on the surface of plastics (plastisphere) in aquatic environments over time. The aim of this study was to describe the bacterial communities associated with plastics in freshwater. Thus, in our first test, a total of six self-designed plastic colonizers were submerged under the surface of the water in Vácszentlászló lake, located in central Hungary, for a period of 3 months. Two plastic colonizers were cultivated monthly. Associated microbial communities were then analyzed as follows: (a) bacterial communities were studied by amplicon sequencing and (b) culturable bacteria were isolated from plastic surfaces and identified by 16S rRNA gene sequencing. Coinciding with these analyses of plastic colonizing communities, surface water samples from the lake were also taken, and in a second test, other materials (eg. wood, glass) associated bacterial communities were also investigated with the same methods. Amplicon sequencing showed notable differences between the plastic and other materials colonizing, and lake waterborne microbial community composition. Using the LB agar, no novel species were found; however, several known pathogenic species were identified. The self-designed plastic colonizer was successfully used during the winter over a 3-month period, suggesting that it could be an appropriate method of choice to study microplastic-associated microbes for longer periods and in variable environmental conditions.
显示更多 [+] 显示较少 [-]Utility of a source-related matrix in basin management studies: a practice on a sub-Basin in Turkey 全文
2021
Hanedar, Asude | Tanik, Aysegul | Girgin, Emine | Güneş, Elçin | Karakaya, Nusret | Gorgun, Erdem | Gökdereli, Gökçen | Çankaya, Burhan Fuat | Kimence, Taner | Karaaslan, Yakup | Dikmen, Bilal
According to the water framework directive (WFD), the chemical status should be determined for each water body in a basin through monitoring and evaluation studies, and the gap between the status of water bodies and good water status should be revealed in river basin management plans. In this context, the methodology starting with the evaluation of the monitoring results of the priority substances (PSs) until the end of determining the measures to achieve good condition in surface waters was given in this study. The key aim was to provide a useful methodology defined as a matrix for determining the sources of pollutants that caused this gap. This matrix was applied to the most polluted sub-basin of Küçük Menderes Basin located on the western part of the Turkey. Monitoring studies were carried out in 21 water bodies for a 1-year period for 45 PSs and monitoring results were compared with environmental quality standards (EQS). It was determined that 13 of 45 PSs in 15 water bodies exceeded the EQS. The common PSs in the basin were lead, nickel, fluoranthene, benzo(a)pyrene, C10–13 chloroalkanes, and 4-nonylphenols and average rates of exceeding the EQS were 58.3%, 36.4%, 91.5%, 99.9%, 74.8%, and 49.4%, respectively. The detailed emission inventory of each water body in the basin has been made. Potential sources of PSs were searched via the matrix formed and a total number of 420 basic and supplementary measures were proposed to improve the water quality of the sub-basin.
显示更多 [+] 显示较少 [-]Geo-referenced simulation of pharmaceuticals in whole watersheds: application of GREAT-ER 4.1 in Germany 全文
2021
Lämmchen, Volker | Niebaum, Gunnar | Berlekamp, Jürgen | Klasmeier, Jörg
The geo-referenced regional exposure assessment tool for European rivers (GREAT-ER) is designed to support river basin management or the implementation process within the EU Water Framework Directive by predicting spatially resolved exposure concentrations in whole watersheds. The usefulness of the complimentary application of targeted monitoring and GREAT-ER simulations is demonstrated with case studies for three pharmaceuticals in selected German watersheds. Comparison with monitoring data corroborates the capability of the probabilistic model approach to predict the expected range of spatial surface water concentrations. Explicit consideration of local pharmaceutical emissions from hospitals or private doctor’s offices (e.g., for X-ray contrast agents) can improve predictions on the local scale without compromising regional exposure assessment. Pharmaceuticals exhibiting low concentrations hardly detectable with established analytical methods (e.g., EE2) can be evaluated with model simulations. Management scenarios allow for a priori assessment of risk reduction measures. In combination with targeted monitoring approaches, the GREAT-ER model can serve as valuable support tool for exposure and risk assessment of pharmaceuticals in whole watersheds.
显示更多 [+] 显示较少 [-]Technological innovation, financialization, and ecological footprint: evidence from BEM economies 全文
2021
Destek, Mehmet Akif | Manga, Muge
Despite the growing interest in researches on the impact of technological development on carbon emissions, the effect of technological innovation on the other indicators of environmental degradation is of little interest. In order to close this gap, the aim of this study is to determine the effects of technological innovation on both carbon emission and ecological footprint for big emerging markets (BEM) countries. In doing so, the environmental impacts of the financialization process are also explored, in line with the fact that these countries face constraints in financing technological developments. In this context, the effects of technological development, financialization, renewable energy consumption, and non-renewable energy consumption on environmental degradation are examined through the second-generation panel data methods for the period 1995–2016. The findings indicate that technological innovation is effective in reducing carbon emissions, but does not have a significant impact on the ecological footprint, namely a 1% increase in technological innovations reduces carbon emission by 0.082–0.088%. Moreover, it is found that financialization harms environmental quality for both indicators of the environment because a 1% increase in financialization increases carbon emissions by 0.203–0.222% and increases ecological footprint by 0.069–0.071%.
显示更多 [+] 显示较少 [-]Mitigating human-induced emissions in Argentina: role of renewables, income, globalization, and financial development 全文
2021
Achieving environmental sustainability has become a global initiative while addressing climate change and its effects. However, the role of energy production and consumption in economic development remains critical amidst environmental pollution. Thus, the need for innovation and clean energy alternatives is critical while pursuing sustainable development. This country-specific study focuses on Argentina, where economic growth trajectory is embedded with high CO₂ emissions. This study assesses the long-term and causal impact of financial development and renewables on environmental pollution while accounting for the role of economic development and globalization using yearly data spanning 1980 to 2017. A battery of econometric methods is applied to underscore the interaction between the parameters of interest. The findings of Maki and ARDL tests of cointegration alongside Kripfganz and Schneider critical approximation p-values affirm long-run equilibrium interaction between variables. The outcomes of autoregressive distributed lag, fully modified, and dynamic ordinary least squares demonstrate that while economic expansion dampens environmental quality—globalization and renewables improve the environment. This finding suggests pollution-driven economic growth trajectory in Argentina with high dependence on fossil fuels. Besides, the gradual shift causality test finds evidence of one-way causality from renewable energy consumption, economic growth, and globalization to CO₂ emissions. Argentina’s pathway in achieving sustainable development requires gradual and inclusive economic shift towards green growth.
显示更多 [+] 显示较少 [-]Hepatoprotective effects of phytochemicals berberine and umbelliferone against methotrexate-induced hepatic intoxication: experimental studies and in silico evidence 全文
2021
Chemotherapeutic drugs are used effectively to manage wide types of malignancies, but their therapeutic use is limited due to their associated hepatic intoxication. The current study sheds light on the effect of phytochemicals berberine (BBR) and umbelliferone (UMB) on methotrexate (MTX)–induced hepatic intoxication. Forty-eight rats were allocated to normal, BBR (50 mg/kg orally for 10 days), UMB (30 mg/kg orally for 10 days), MTX (20 mg/kg at the 5th day), BBR+MTX, and UMB+MTX. With regard to MTX, the results of this investigation reveal potent amelioration of MTX hepatotoxicity by BBR and UMB through reduction of the elevated serum levels of ALT, ALP, AST, and LDH confirmed by the attenuation of histopathological abrasion in liver tissues. BBR and UMB markedly restored antioxidant status. More importantly, BBR resulted in reducing P₃₈ mitogen–activated protein kinase (P₃₈MAPK), nuclear factor kappa-B (NF-κB), and Kelch-like ECH-associated protein 1 (Keap-1) genes and enhanced mRNA expression of Nrf-2 (P < 0.05). Interestingly, in silico studies via molecular docking pinpointed the binding modes of BBR and UMB to the binding pocket residues of P₃₈MAPK, NF-κB, and Keap-1 and demonstrated a promising inhibition of Keap-1, P₃₈MAPK, and NF-κB. BBR and UMB reduced the expression of pro-apoptotic protein Bax and apoptotic protein caspase-3 as well as increased the expression of anti-apoptotic protein Bcl-2. Therefore, BBR and UMB may denote promising therapeutic agents that can avert hepatic intoxication in patients receiving MTX.
显示更多 [+] 显示较少 [-]The evolution of new ventures’ behavioral strategies and the role played by governments in the green entrepreneurship context: an evolutionary game theory perspective 全文
2021
Yang, Xu | Liao, Shan | Li, Runmao
Green entrepreneurship is a special type of entrepreneurship that can achieve sustainable development, which is advocated for by many countries and regions. Accordingly, large-scale green entrepreneurship activities of new ventures are appearing in the emerging green industry around the world. To initially study how to promote the diffusion of eco-innovation in green entrepreneurship activities, the evolutionary game models of new ventures’ eco-innovation and greenwashing behavior affected by market mechanisms and government regulations were respectively established. Furthermore, a benign evolution path of the system was proposed by analyzing the evolutionary stable state of the green entrepreneurial system composed of the government and new ventures. Then, the simulation analysis was carried out using a case study to more intuitively observe the influence of some important parameters including government subsidies and so forth on the evolutionary stable state of the system. The research showed that it is difficult for pure market mechanisms to promote the spread of new ventures’ eco-innovation behaviors in the initial stage of the development of the emerging green industry, and the government regulation is exceedingly important. The parallel use and timely adjustments between the government subsidy and penalty mechanisms can effectively promote the diffusion of new ventures’ eco-innovation behaviors under certain conditions. Besides, the size (positive and negative) of the benefits gaps realized by “greenwashing” and “eco-innovation” radically determines the direction and result of the evolution of new ventures’ behavioral strategies.
显示更多 [+] 显示较少 [-]Stress and Recovery Responses of Microcystis aeruginosa Exposed to Extreme Light for Different Durations 全文
2021
Senavirathna, Mudalige Don Hiranya Jayasanka | Muhetaer, Guligena | Yan, Hongyu | Aihemaiti, Bahaguri | Fujino, Takeshi
Cyanobacterial growth is a significant problem in most parts of the world. Control measures are necessary to suppress cyanobacterial growth in natural water bodies. When the control measures were discontinued, cyanobacteria growth rebounded quickly. This study was conducted to provide insight into the stress and recovery responses of cyanobacteria. Microcystis aeruginosa was exposed to extreme light for 8 days, and the changes in response to the light exposure were observed. Post-exposure recovery performances were accessed by allowing Cyanobacteria to recover under optimum conditions for 8 days. Extreme light exposure causes stress on M. aeruginosa, but by adjusting the growth, pigmentation, chlorophyll fluorescence, and antioxidant levels, M. aeruginosa surpasses the stress. M. aeruginosa showed sudden changes in parameters on the eighth day of extreme light exposure. The post-stress recovery capacity of M. aeruginosa was positively correlated with the exposure duration. These findings suggest that exposure to light stress causes hardening of M. aeruginosa. The inter-parameter relationships differed between the stress and recovery phases. Besides, non-photochemical quenching was strongly correlated with cellular H₂O₂ content, which can indirectly explain the oxidative stress status of M. aeruginosa. This study highlights the research requirement on the post-stress recovery capacity of M. aeruginosa.
显示更多 [+] 显示较少 [-]Use of Natural Zeolite and Its Mixtures to Refine High-Concentrated Heavy Metal-Contaminated Wastewater: an Investigation of Simultaneous Removal of Cd (II) and Pb (II) by Batch Adsorption Method 全文
2021
Kumara, G. M. P. | Kawamoto, K.
This study investigated the simultaneous removal of Cd²⁺ and Pb²⁺ from wastewater using commercially available Japanese zeolite (JPZ) and its mixtures. A series of batch adsorption experiments were carried out to examine the simultaneous removal of Cd²⁺ and Pb²⁺ in binary and multi-metal solutions. Results revealed that JPZ (0.105–2.0 mm) exhibited a higher affinity for Pb²⁺ (>250 mg/g) over Cd²⁺ (<50 mg/g) in single metal solutions. However, in binary and multi-metal solutions, dominant adsorption of Pb²⁺ ions and hampering of Cd²⁺ ion adsorption were observed like in other types of low-cost adsorbents. Thus, steel slag (SS) grain, which is an industrial by-product and has a high affinity for Cd²⁺, was mixed with JPZ in different proportions to evaluate the potential use for simultaneous removal of Cd²⁺ and Pb²⁺. The JPZ+SS mixtures (JPZ+SS [4:1], JPZ+SS [1:1], and JPZ+SS [1:4]) were performed better than JPZ alone on simultaneous removal of Cd²⁺ and Pb²⁺. The JPZ+SS [1:1] mixture was identified as the most effective one for the simultaneous removal of Cd²⁺ and Pb²⁺ from binary and multi-metal solutions. The selectivity sequence in multi-metal solution was observed as Cd²⁺≈Pb²⁺≈Cu²⁺≈Zn²⁺≈Ni²⁺ and 100% removal of heavy metals were observed. The Cd²⁺ and Pb²⁺ removal by JPZ+SS mixtures mainly occurred due to the Ca²⁺ ion-exchange reaction along with the precipitation and surface complexation. Especially, the amount of SS grain in the mixtures played a vital role in the removal process of Cd²⁺ and Pb²⁺ from wastewater.
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