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Anti-migraine activity of freeze-dried latex obtained from Calotropis gigantea Linn Texte intégral
2022
Bhatia, Saurabh | Al-Harrasi, Ahmed | Kumar, Arun | Behl, Tapan | Sehgal, Aayush | Singh, Sukhbir | Sharma, Neelam | Anwer, Md Khalid | Kaushik, Deepak | Mittal, Vineet | Chigurupati, Sridevi | Sharma, Pritam Babu | Aleya, Lotfi | Vargas-de-la-Cruz, Celia | Kabir, Md Tanvir
Migraine which is characterized by a pulsating headache affected an estimated population of 12% worldwide. Herbal products like latex derived from Calotropis gigantea R. Br. (Asclepiadaceae) are a representative intervention to treat migraine traditionally. However, post-harvesting stability issues of latex affect its biological potential. Freeze-drying has been successfully employed for the encapsulation of herbal bioactive compounds resulting in stable dried preparations. Latex derived from Calotropis gigantea (C. gigantea) was microencapsulated using chitosan by freeze-drying (FDCG) method and compared with sun ray–dried latex (ADCG). Current investigation was aimed to improve the shelf life of latex by freeze-drying microencapsulation technique and evaluation of its anti-migraine potential. Dried latex powders (ADCG and FDCG) were evaluated in terms of phenolic content, coloring strength, first-order kinetic, color parameters (L*, a*, b*, C*, and E*), moisture, water activity, solubility, and hygroscopicity. Additionally, apomorphine-induced climbing behavior, L-5-HTP–induced syndrome, and MK-801–induced hyperactivity were used to evaluate the anti-migraine potential of powdered latex. FDCG showed good physicochemical properties due to its higher concentration of phenolic and flavonoid contents. Moreover, FDCG significantly reduced the apomorphine-induced climbing behavior, L-5-HTP–induced syndrome, and MK-801–induced hyperactivity in a dose-dependent manner through an interaction of dopaminergic and serotonergic receptors. In conclusion, the method developed for shelf life improvement of latex offered maximum protection over a period of 10 weeks with retaining its natural biological potential; thus, it can be effectively utilized in the treatment or management of migraine. Anti-migraine effect of Calotropis gigantea freeze-dried latex by inhibition of dopamine and serotonin receptors (D1 and D2: dopamine receptors; 5-HT: serotonin receptors); yellow color represents serotonergic, and blue color indicates dopaminergic neurons
Afficher plus [+] Moins [-]Phytoplankton characterization in a tropical tidal river impacted by a megacity: the case of the Saigon River (Southern Vietnam) Texte intégral
2022
Nguyen, An Truong | Dao, Thanh-Son | Strady, Emilie | Nguyen, Tuyet T.N. | Aimé, Joanne | Gratiot, Nicolas | Némery, Julien
The spatiotemporal variation of phytoplankton and their relationship with environmental variables were analyzed in the Saigon River—a tropical river in Southern Vietnam. Two longitudinal profiles were conducted during dry and rainy season at 18 sampling sites covering more than 60 km long in the river. Besides, a bi-weekly monitoring conducted in the upstream, urban area (Ho Chi Minh City—HCMC), and downstream of Saigon River was organized from December 2016 to November 2017. The major phytoplankton were diatoms (e.g., Cyclotella cf. meneghiniana, Leptocylindrus danicus, Aulacoseira granulata), cyanobacteria (Microcystis spp., Raphidiopsis raciborskii, Pseudanabaena sp.), and euglenoids (Trachelomonas volvocina). Commonly freshwater phytoplankton species and sometimes brackish water species were dominant during the monitoring. Phytoplankton abundances in dry season were much higher than in rainy season (>100 times) which was explained by a shorter riverine water residence time and higher flushing capacity during the dry season. There was a clear separation of phytoplankton abundance between the urban area and the remaining area of Saigon River because of polluted urban emissions of HCMC. Redundancy analysis shows that the environmental variables (TOC, nitrogen, pH, salinity, Mo, Mn) were the driving factors related to the dominance of L. danicus and Cyclotella cf. meneghiniana in the upstream river and urban section of Saigon River. The dominance of cyanobacterium Microcystis spp. in the downstream of Saigon River was related to higher salinity, Mg, Cu concentrations, and lower concentrations of nutrients, Mn, Co, and Mo. The dominance of potentially toxic cyanobacteria in Saigon River possesses health risk to local residents especially upon the increasing temperature context and nutrient loading into the river in the next decades.
Afficher plus [+] Moins [-]Dynamic behavioral characteristics of carbon dioxide emissions from energy consumption: the role of shale technology Texte intégral
2022
Shirazi, Masoud | Šimurina, Jurica
Dynamic behavioral analysis of carbon dioxide ([Formula: see text]) emissions to moderate the climate change helps to upgrade the developing measures utilized throughout the energy system decarbonization and mitigate global warming. Therefore, this research aims to analyze the role of the shale gas technology in behavioral characteristics of the US energy-related [Formula: see text] emissions. To this end, first, the Markov regime-switching methodology is used to assess the scale- and technology effects of the shale revolution on the switching-regimes for source-/sector-based [Formula: see text] emissions cycles of the US economy. Then, the dynamic network connectedness measures are utilized to determine the changes in the spillover effects between [Formula: see text] emissions cycle series by source/sector pre- and post-shale revolution. The findings indicate asymmetric and time-varying behavior of [Formula: see text] emissions cycles pre- and post-revolution. Particularly, the greater total spillover effect of the US source- and sector-based [Formula: see text] emissions network is accompanied with the higher speed of “downward” regime following the revolution that lowers environmental degradation of the US economy. Hence, utilization of the US economies of scale in the shale technology develops the coordinating mechanism, which can support the cooperative relationship between sources/sectors of the energy system in response to the risks, time and cost change, caused by the shale revolution.
Afficher plus [+] Moins [-]Meteorological factors contributing to organic and elemental carbon concentrations in PM10 near an open-pit coal mine Texte intégral
2022
Arregocés, Heli A. | Rojano, Roberto | Restrepo, Gloria
Variations in the carbonaceous aerosol contents, organic carbon (OC) and elemental carbon (EC), in particulate matter less than 10 μm in size (PM₁₀), were analyzed at sites influenced by coal mining in an open-pit mine located in northern Colombia. Samples were collected during different seasonal periods throughout 2015. Meteorological variables for each site were examined during the different seasons. Aerosols were detected using a thermal-optical reflectance protocol method. The highest PM₁₀ concentrations, between the ranges of 28.2 ± 8.2 μg m⁻³ and 75.0 ± 36.5 μg m⁻³, were recorded during the dry season. However, the highest concentrations of OC (4.8–14.2 μg m⁻³) and EC (2.9–13.9 μg m⁻³) in PM₁₀ were observed during the transition period between the dry and wet seasons. The strong correlation between OC and EC in PM₁₀ (r = 0.6–1.0) during the transition season indicates a common primary combustion source. High OC (> 8.3 μg m⁻³) and EC (> 6.9 μg m⁻³) concentrations were associated with low wind speeds (< 2.1 m s⁻¹) moving in different directions. Analyses of the sources of atmospheric aerosol pollutants in the mining area in northern Colombia showed that the daily maximum total carbon concentrations were mainly associated with regional atmospheric transport of particulate matter from industrial areas and biomass burning sites located in the territory of Venezuela.
Afficher plus [+] Moins [-]Effect of strontium on nutrient uptake, physiological parameters, and strontium localization in lettuce Texte intégral
2022
Yan, Dong | Ding, Kuke | He, Yingxue | Fan, Li | Che, Yongfei | Zhao, Yingjun | Jiang, Xiaoyan
Human activities increase the risk of stable and radioactive strontium (Sr) isotopes entering the environment and food chain. In this study, the effects of Sr on the nutrient uptake and physiological responses of lettuce under different “Sr treatment” concentrations (0, control, 1, 2, 3, 4, and 5 mM) and “times” (7, 14, and 21 day) were studied in a hydroponic system. In addition, the distribution of Sr on the surfaces and cross-sections of lettuce leaves was revealed by scanning electron microscopy with energy-dispersive X-ray (SEM–EDX) analysis. A two-way analysis of variance (ANOVA) method was used to analyze the significance of “Sr treatment,” “time,” and their “interaction.” The results showed that an increase in Sr uptake in lettuce could significantly reduce the uptake of calcium (Ca). The contents of sulfur (S), potassium (K), and iron (Fe) in lettuce leaves showed significant differences with the sampling day. Similarly, the fresh weight of lettuce leaves and roots as well as the photosynthetic pigment contents of lettuce leaves was also significantly different with the sampling day. The activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)) showed significant differences with the sampling day. The activities of SOD and CAT decreased significantly with the sampling day, while POD increased significantly. The MDA content increased significantly with increasing hydroponic Sr concentration on the 21st day. SEM–EDX analysis showed that the weight percentage of Sr in the vascular bundle sheath in the cross-section of lettuce leaves was relatively higher than that in the mesophyll. This study aids our understanding of the distribution of Sr in lettuce leaf tissues and the effect of Sr on lettuce physiology.
Afficher plus [+] Moins [-]Does policy uncertainty threaten renewable energy? Evidence from G7 countries Texte intégral
2022
Khan, Khalid | Su, Chi Wei
This study evaluates economic policy uncertainty (EPU) impact on renewable energy (RE) in the G7 countries. The finding explores a negative impact of EPU on RE across all quantiles, suggesting that EPU disturbs the macroeconomy, which leads to the decline in RE. However, the impact occurs in the upper quantiles, which recommends that high EPU influences RE rapidly. The coefficients show the varying effects of EPU on RE, as the impact of EPU decreases in Germany when the relationship changes from short to long term. Similarly, the impact increases in Italy, Japan, the UK, and the USA when the relationship changes from short to long run. The sustainable development of RE requires greater economic stability. This is possible if the government makes future policies by involving all stakeholders. Complete information about the planning, implementation, and modification of economic policies should be readily shared with all participants.
Afficher plus [+] Moins [-]Quantile relationship between globalization, financial development, economic growth, and carbon emissions: evidence from Vietnam Texte intégral
2022
Hung, Ngo Thai | Trang, Nguyen Thu | Thang, Nguyen Thanh
Environmental quality and economic activity have a strong relationship. Carbon emissions remain one of the world’s most dangerous environmental issues. Both international and local governments are developing initiatives to address this problem. Capitalizing on the limitations of the existing literature, this article investigates the dynamic nexus of financial development, economic growth, and globalization on carbon dioxide emissions in Vietnam for 1990–2020 using the quantile-on-quantile regression. The findings unveil a positive feedback link between globalization and carbon dioxide emissions at the middle and high quantiles. In addition, there is a negative nexus between financial development and carbon emissions at most quantiles, while CO₂ emissions and economic growth have a positive association at all quantiles. More importantly, our empirical results also provide the bidirectional causality between financial development, economic growth, globalization, and carbon dioxide emissions in Vietnam at different quantile levels. The consistency of the outcomes uncovers that the findings are trustworthy and appropriate for guiding policy to reduce CO₂ emissions in Vietnam. Therefore, they can help policymakers understand how financial development and globalization can achieve sustainable economic growth and tackle environmental issues in this country.
Afficher plus [+] Moins [-]Analysis of spatial and temporal changes of vegetation cover and its driving forces in the Huainan mining area Texte intégral
2022
Zhang, Xuyang | Liu, Ying | Chen, Xiaoyang | Long, Linli | Su, Yongdong | Yu, Xiaokun | Zhang, Hongmei | Chen, Yongchun | An, Shikai
The Huainan mining area is rich in coal resources and has sparse vegetation and many collapsed waterways. Large-scale and long-term underground coal mining has led to a fragile ecological environment in the mining area, and it is urgent to solve the contradiction between coal development and ecological environmental protection. The Huainan mining area was selected as the research object, and the vegetation cover was extracted using 10-phase Landsat multispectral remote sensing images from 1989 to 2021 to analyze its spatial and temporal changes and driving forces to provide a scientific basis for the guided restoration of the ecological environment in the region. Combined with the image dichotomous model, regression slope, correlation coefficient, and standard deviation of vegetation cover grid points in different time series, standard deviation ellipse, and center of gravity migration, we analyzed the spatial and temporal variation pattern of vegetation cover for 33 years and revealed the responses of temperature, precipitation, population density, GDP, and afforestation area to vegetation cover. Results show the following: (1) from 1989 to 2021, the overall vegetation cover in the study area tended to decrease with 36.48% of the areas increasing and 63.52% of the areas decreasing, primarily in the very low and medium range; (2) the center of gravity of different types of vegetation cover generally shifted from north to south during 33 years; (3) climate and social activities had a substantial effect on the spatial heterogeneity of the vegetation cover in the study area. There is significant spatial heterogeneity in the effects of climate and social activities on the vegetation in the study area with human activities negatively correlating with vegetation cover. Mining activities are the primary driver of the evolution of regional vegetation cover, with climate change serving as a secondary driver.
Afficher plus [+] Moins [-]The dynamic impacts of environmental-health and MDR-TB diseases and their influence on environmental sustainability at Chinese hospitals Texte intégral
2022
Dai, Zong | Sadiq, Misbah | Kannaiah, Desti | Khan, Nasir | Shabbir, Malik Shahzad | Bilal, Kanwal | Tabash, Mosab I.
The purpose of this study is to identify at what extent multidrug-resistant tuberculosis (MDR-TB) diseases effect on environmental health issues in selected provinces of Chinese hospitals. In survival analysis approach, this study employs the Cox proportional hazard model (CPM) to incorporate the duration of event, probability of occurrence of an event, and the issue of right censoring. An advantage of using CPM is that one does not need to specify the distribution of baseline hazard H₀ (t) as it considers a common value for all units in population. The results indicate that male and travel expenditures have negative association with the duration of cure. Furthermore, the medical expenditures and the spatial characteristic of time expenditure have positive association with the duration of cure of MDR-TB patients. The inconsistent behavior of males in taking medicines as compared to females and males is also more prone to tuberculosis (TB).
Afficher plus [+] Moins [-]An evaluation of temporal changes in physicochemical properties of gully pot sediments Texte intégral
2022
Wei, Haoyu | Muthanna, Tone Merete | Lundy, Lian | Viklander, M.
Diffuse pollution is recognised as a major challenge in achieving EU Water Framework Directive compliance, with urban runoff being a key pathway connecting various sources to receiving waters. Gully pots, as one of the ubiquitous urban drainage infrastructures, are placed at the inlets of piped drainage pipe network and actively drain runoff from urban catchment with suspended solids proportionally retained. The physiochemical properties of these retained solids reflect the activities within the catchment during the accumulation period. In this work, seven gully pots in two catchment types (highway and housing) in Luleå, Sweden were fully emptied and sediments analysed for total mass, particle size distribution and selected metal concentrations by six size fractions. The results of this sampling campaign are compared with the results of a 2005 study of the same gully pots to identify changes in the physicochemical properties of sediments over time and examine whether changes identified can be linked to changes in wider catchment management practices. The results highlight the potential impacts of winter road maintenance operations (e.g. up to a 15-fold higher solids loading rate in road catchment gully pots), reaching a normalised solids accumulation rate of 0.176–0.819 kg m² year⁻¹. An increase in tyre and road wear associated with winter road maintenance operations is also understood to contribute to the temporal increase of several metals including Cu, Zn, Co, Cr and V in the < 63-µm solids fraction in the road catchment gully pots. The concentrations of As and Pb decrease in all size fractions in both catchments, with the implementation of unleaded fuels (for Pb in housing catchment only), End-of-Life Vehicle Directive (Directive 2000/53/EC) (for Pb in both catchments), and strengthened industrial emission reduction measures suggested as possible drivers. The high contamination load for Zn, Cu, Cd and Pb in < 63-µm sediments from low-traffic housing catchment also emphasised the necessity of tracing and restricting non-traffic-related metal sources. Further seasonal monitoring of gully pot sediments is recommended to fully follow up the development of metals loading in both catchments.
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