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Resultados 5531-5540 de 6,489
Fractionation analysis and health risk assessment of heavy metals in six traditional Chinese medicines Texto completo
2020
Nan, Guanjun | Meng, Xianxin | Song, Ning | Liu, Zhengzheng | Liu, Yu | Yang, Guangde
Traditional Chinese medicines (TCMs) are widely used to treat various diseases in China and some countries, and TCM products are becoming increasingly available and popular worldwide. But TCMs are facing the challenge of heavy metal pollution. In this work, we examined the total contents and fractionations of Pb, Cd, Hg, and Cu in six TCMs (Angelicae Sinensis Radix (ASR), Chuanxiong Rhizoma (CR), Polygonati Rhizoma (PR), Astragali Radix (AR), Carthami Flos (CF), and Paeoniae Radix Rubra (PRR)) and evaluated the health risk of four heavy metals in these TCMs. The results showed that Cd, Pb, and Cu contents were considerably high and the amount of Cd in six TCMs, Pb in CR, ASR, AR, and CF, and Hg in ASR, PR, and PRR exceeded the limit values. The predominant fractions of Pb, Cd, and Cu were exchangeable and carbonate fractions in six TCMs; Hg mainly existed in organic and residual fractions. The average daily intake dose (ADD) and target hazard quotient (THQ) of Pb based on total content and total THQ of four heavy metals based on bioaccessible fractions in AR and PRR exceeded the safety guideline. These results indicated that the potential health risk could occur by taking these TCMs.
Mostrar más [+] Menos [-]The impact of CEO tenure on corporate social and environmental performance: an emerging country’s analysis Texto completo
2020
Khan, Talat Mehmood | Gang, Bai | Fareed, Zeeshan | Yasmeen, Rizwana
This paper analyzes the extent to which CEO (chief executive officer) tenure affects the corporate social and environmental performance of all nonfinancial Chinese firms listed in Shanghai and Shenzhen stock exchanges during 2009–2015. The study uses a fixed-effect panel regression model by considering the overtime data across the firms. 2SLS regression model then is used to control the problem of endogeneity. The study confirms the negative effect (8.8%) of the increase in CEO tenure on the corporate social and environmental performance. The findings also explain that the corporate social and environmental performance of CEOs increases significantly in the initial years of service than in their later years. The study concludes that an inverse relationship between CEO tenure and corporate social and environmental performance is more pronounced with a higher percentage of independent directors, where CEOs have longer anticipated employment tenure and firms under state control, consistent with the signalling explanation of career concern and career horizon effect. Finally, the impact of CEO tenure on corporate social and environmental performance has become stronger in recent years.
Mostrar más [+] Menos [-]The shale gas production and economic growth in local economies across the US Texto completo
2020
Bilgili, Faik | Koçak, Emrah | Bulut, Ümit
Recently, several seminal works have been drawing attention to the revolution of shale gas production technology of the USA, the impact of shale gas on energy sectors, as well as the influences of shale gas on macroeconomic variables of employment, economic growth, etc. Nevertheless, one may claim that two gaps appear in literature. The first gap is the absence of an econometric study estimating the effect of shale oil/gas on national economies. The more considerable second gap is the absence of econometric analyses revealing the impulses of shale gas on local economies. Therefore, this paper observes the possible causalities between the shale gas and local gross domestic product (GDP) employing quarterly data covering the period 2007–2016 for 12 states in the US. After performing the tests of cross-sectional dependence, heterogeneity, stationarity, and cointegration, the paper conducts the panel Granger causality analyses. The empirical findings depict that (i) there is available unidirectional relationship from local shale gas production to local GDP in Colorado, Ohio, and West Virginia; (ii) there occurs an impulse from GDP to local shale gas production for Louisiana, North Dakota, and Oklahoma; (iii) a bidirectional causality coexists between local shale gas production and GDP in Arkansas, California, and Texas; and (iv) there exists no association between local GDP and local shale gas extraction in Montana, New Mexico, and Wyoming.
Mostrar más [+] Menos [-]A review: application of remote sensing as a promising strategy for insect pests and diseases management Texto completo
2020
Abd El-Ghany, Nesreen M. | Abd El-Aziz, Shadia E. | Marei, Shahira S.
The present review provides a perspective angle on the historical and cutting-edge strategies of remote sensing techniques and its applications, especially for insect pest and plant disease management. Remote sensing depends on measuring, recording, and processing the electromagnetic radiation reflected and emitted from the ground target. Remote sensing applications depend on the spectral behavior of living organisms. Today, remote sensing is used as an effective tool for the detection, forecasting, and management of insect pests and plant diseases on different fruit orchards and crops. The main objectives of these applications were to collate data that help in decision-making for insect pest management and decreasing the environmental pollution of chemical pesticides. Airborne remote sensing has been a promising and useful tool for insect pest management and weed detection. Furthermore, remote sensing using satellite information proved to be a promising tool in forecasting and monitoring the distribution of locust species. It has also been used to help farmers in the early detection of mite infestation in cotton fields using multi-spectral systems, which depend on color changes in canopy semblance over time. Remote sensing can provide fast and accurate forecasting of targeted insect pests and subsequently minimizing pest damage and the management costs.
Mostrar más [+] Menos [-]Impact of temperature changes between neighboring days on COPD in a city in Northeast China Texto completo
2020
Ma, Yuxia | Jiao, Haoran | Zhang, Yifan | Cheng, Bowen | Feng, Fengliu | Yu, Zhiang | Ma, Bingji
Sudden temperature changes between neighboring days (T₂₄ₕ) have adverse effects on human health. In this study, we used a time series analysis to evaluate the impact of T₂₄ₕ on the number of hospital admissions for chronic obstructive pulmonary disease (COPD) from 2009 to 2012 in Changchun (the capital of Northeast China’s Jilin province). We performed the analysis in a generalized additive model (GAM), and the controlling factors included long-term trends, day of the week effect, and the selected weather elements. We divided the entire study group into two gender subgroups (males and females) and two age subgroups (aged < 65 years and aged ≥ 65 years). T₂₄ₕ showed the greatest effect on the entire study group at lag 3 days. In particular, the greatest effect of T₂₄ₕ on females (males) occurred at lag 1 day (lag 3 days); the greatest effect of T₂₄ₕ on the aged ≥ 65 years (aged < 65 years) occurred at lag 1 day (lag 6 days). This indicates that temperature changes between neighboring days have a relatively more acute effect on the elderly and the females than on the younger people and the males. When T₂₄ₕ is less than zero, the highest RR of the number of hospital admissions for COPD occurred at lag 4 days during the warm season (1.025, 95% CI: 0.981, 1.069) and lag 3 days during the cold season (1.019, 95% CI: 0.988, 1.051). When T₂₄ₕ is greater than zero, the highest RR of the number of hospital admissions for COPD occurred at lag 6 days during the warm season (1.026, 95% CI: 0.977, 1.077) and lag 5 days during the cold season (1.021, 95% CI: 0.986, 1.057). The results of this study could be provided to local health authorities as scientific guidelines for controlling and preventing COPD in Changchun, China.
Mostrar más [+] Menos [-]The influence of information communication technology on farmers’ sales channels in environmentally affected areas of China Texto completo
2020
Sheng, Jie | Lu, Qian
The rapid development of information communication technology (ICT), represented by mobile phones and the Internet, allows capitalizing to a greater extent on the wealth of information and knowledge available for agriculture knowledge and can be used to increase production, conserve the environment, etc. This study analyzes the current market-oriented behavioral effects of information communication technologies on farmers, based on data of 1263 rural households in two highly environmentally affected and major vegetable producing provinces—Shandong and Hebei. A probit model was used to analyze the impact of information communication technology on the choice of farmers’ sales channels. The results show that the differences between the farm households with and without access to ICT, as well as those who actively or passively acquire information, have a significant impact on the choice of sales channels. Using ICT increases the probability that farmers choose sales through middlemen and cooperatives and reduces the probability of self-sales. Actively acquiring information has a positive impact on the cooperative channel choice and a significant negative impact on self-sales. Accordingly, we recommend that the government should increase the penetration rate of ICT, strengthen the information technology in rural areas, emphasize the construction of information sources, such as the collection and distribution of market information, enhance information literacy among farmers, reduce their transaction costs, and increase overall farmer participation in the market.
Mostrar más [+] Menos [-]Accelerated photodeterioration of class I toxic monocrotophos in the presence of one-pot constructed Ag3PO4/polyaniline@g-C3N4 nanocomposite: efficacy in light harvesting Texto completo
2020
Balasubramanian, Jeyaprabha | Ponnaiah, Sathish Kumar | Periakaruppan, Prakash | Kamaraj, Dhivya
Water and soil contamination has become unavoidable due to the enormous usage of pesticides in agriculture. Among the pesticides, monocrotophos (MCP), a popular and largely used pesticide, is extremely toxic to birds and humans, which is easily leached into the environment. Therefore, establishment of a green tactic to clean the environment from such hazard is very essential. Herein, we have developed a novel ternary nanocomposite, Ag₃PO₄/polyaniline@g-C₃N₄ with enhanced electron-hole separation efficiency, a condition which is very much required for any photocatalyst. The nanocomposite was one-pot synthesized by a simple and economical hydrothermal method. The strategically modulated band gaps of the nanocomposite help harvest the sunlight efficaciously for the robust degradation of MCP (99.6%). It has been found that the active species involved in the photo-cleaning process are OH· and O₂·⁻. A suitable reaction mechanism has been proposed and discussed. Analytical techniques, which include energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FE-SEM), elemental mapping analysis, high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS), and X-ray diffraction (XRD), were used to characterize the synthesized nanocomposite. This nano-photocatalyst, which is simple, stable, and reusable, certainly has potential applications in soil contamination remediation, sewage treatments, and other environment decontaminations. Also, a study of this kind offers more strategic plans for the production of clean energy (hydrogen) by solar-driven water splitting.
Mostrar más [+] Menos [-]Identification of cadmium-produced lipid hydroperoxides, transcriptomic changes in antioxidant enzymes, xenobiotic transporters, and pro-inflammatory markers in human breast cancer cells (MCF7) and protection with fat-soluble vitamins Texto completo
2020
Darwish, Wageh Sobhy | Chen, Zhen | Li, Yonghan | Wu, Yue | Chiba, Hitoshi | Hui, Shu-Ping
Cadmium (Cd) is a toxic metal that is regarded as a metallohormone with estrogen-like properties. The present study aimed at identification of lipid hydroperoxides produced in human breast cancer (MCF7) exposed to cadmium (Cd) at environmentally relevant levels. Cd induced cytotoxicity and oxidative stress and produced a series of 26 lipid hydroperoxide species including 14 phosphatidylcholine hydroperoxides (PC-OOH), 9 triacylglycerol hydroperoxides (TG-OOH), and 3 cholesteryl ester hydroperoxides (CE-OOH). Among these hydroperoxides, PC34:2-OOH, PC34:3-OOH, TG60:14-OOH, TG48:5-OOH, TG60:15-OOH, and CE20:4-OOH were produced in a dose-dependent manner, suggesting these as possible biomarkers for Cd exposure in MCF7 cells. In addition, Cd led to significant decreases in the gene expressions of antioxidants, detoxification enzymes, and xenobiotic transporters. In a protection trial, co-exposure of MCF7 cells to fat-soluble vitamins including vitamin A, D, and E reduced Cd-induced cytotoxicity, lipid peroxidation, oxidative stress, and inflammatory responses. Fat-soluble vitamins upregulated antioxidant and detoxification enzymes, and xenobiotic transporters. Therefore, dietary supplementation of such micronutrients is recommended for people at risk for exposure to Cd.
Mostrar más [+] Menos [-]Clinical features and first degree relative breast cancer, their correlation with histological tumor grade: a 5-year retrospective case study of breast cancer in Mizoram, India Texto completo
2020
Zodinpuii, Doris | Pautu, Jeremy Lalrinsanga | Zothankima, Bawitlung | Pachuau, Lalawmpuii | Kumar, Nachimuthu Senthil
The aim was to assess the association of histological tumor grade with other clinical features and epidemiological factors of women with invasive breast carcinoma. A retrospective study of 103 Mizo breast cancer patients visiting hospitals was made in Aizawl, Mizoram, Northeast India. With a prior consent, information on epidemiological factors and family history in relation to cancer was obtained. Clinical reports were obtained from their medical records. The frequency of distribution was calculated for age at diagnosis and tumor characteristics. Statistical analysis for different variables was done using a chi-square test. p < 0.05 was considered significant. The histological tumor grades in our studies were found to be associated with lymph node invasion (p < 0.021), different subtype of hormone receptor such as ER status (p < 0.004), ER/PR status (p < 0.007), HER2/neu status (p < 0.014), and ER/PR/HER2 status (p < 0.025). A patient with a family history of breast cancer in their 1st degree relative is also seen to have association in determining the tumor grade (p < 0.003). Reproductive history, lifestyle and dietary habits, tobacco, and alcohol consumption were found to have no influence on breast cancer tumor grade. Our results showing significant correlation between status of lymph node, ER, PR, and HER2/neu oncoprotein and family history with 1st degree relative breast cancer are the first time report to target and focus on the possible role of biomarkers for diagnosis among the Mizo tribal breast cancer patients.
Mostrar más [+] Menos [-]Synthesis of mesoporous magnetic polypyrrole and its application in studies of removal of acidic, neutral, and basic pharmaceuticals from aqueous medium Texto completo
2020
Pires, Bruna Carneiro | Dutra, Flávia Viana Avelar | Borges, Keyller Bastos
As an alternative to traditional adsorbents, mesoporous magnetic polypyrrole (MMPPy) was first used as an adsorbent for the removal of acid, neutral, and basic pharmaceutical compounds considered aqueous pollutants. Ibuprofen (IBU, acid), caffeine (CAF, neutral), and bupropion (BUP, basic) were chosen as adsorbates and applied in adsorption studies. They proved to be pH dependent of the aqueous solution and the best results were found at pH 4 for IBU and CAF and pH 7 for BUP and 60 mg was the optimal amount of adsorbent to be used in the studies. Adsorption was extremely fast and the equilibrium was reached up to 180 s. The adsorption data of all analytes could be well interpreted by the pseudo second-order kinetic model and the dual-site Langmuir-Freundlich isotherm model. The adsorption capacities obtained by the dual-site Langmuir-Freundlich model were 53.67 mg g⁻¹, 16.74 mg g⁻¹, and 24.72 mg g⁻¹ for IBU, CAF, and BUP, respectively. Thermodynamic parameters revealed that IBU adsorption becomes spontaneous as temperature increases and CAF and BUP adsorption occurs through a non-spontaneous process. In addition, this study shows endothermic nature of the adsorption process. Analytes were desorbed using an aqueous solution at pH 10 for IBU, pH 7 for CAF, and pH 4 for BUP and then the material was regenerated successfully. The results suggest that MMPPy can be efficiently used in the removal of different organic analytes found in contaminated water.
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