Уточнить поиск
Результаты 3301-3310 из 8,010
Textile ageing due to atmospheric gases and particles in indoor cultural heritage Полный текст
2021
Uring, Pauline | Chabas, Anne | Alfaro, Stéphane C.
Textile fibre degradation can be due to many factors. The most common cause is light exposure, but upon the lifespan of a textile, many other environmental factors are to be taken into account. This study focuses on the role of atmospheric compounds—both particulate and gaseous species—on natural textiles ageing, more specifically cotton, silk and wool. To achieve this, reference samples of textiles were exposed to contrasted environments (marine, urban and semi-rural museums and historical buildings) for natural ageing. These conditions were also reproduced in an experimental chamber dedicated to the study of the impact of airborne pollutants on heritage materials. Experimental ageing allowed to highlight degradation mechanisms for each fibre: SO₂ and HCOOH cause the cleavage of cotton's glyosidic links and silk’s peptide bonds, while NO₂ promotes the oxidation of the fibres. The most harmful pollutant towards cotton is NO₂ since it causes both its oxidation and hydrolysis. The case of wool is more complicated: HCOOH provokes peptide link cleavage (similarly to silk) but this fibre is less sensitive to SO₂ attacks than silk and even seems to be protected against future alterations after having been firstly exposed to this pollutant. In any case, this experimental study evidences that damages caused by gaseous pollutants are fostered by the presence of particles, regardless of the chemical composition of the particle coating.
Показать больше [+] Меньше [-]Trans-ferulic acid ameliorates cisplatin-induced testicular damage via suppression of TLR4, P38-MAPK, and ERK1/2 signaling pathways Полный текст
2021
Hassanein, Emad H. M. | Abdel-Wahab, Basel A. | Ali, Fares E. M. | Abd El-Ghafar, Omnia A. M. | Kozman, Magy R. | Sharkawi, Souty M. Z.
Testicular damage has been described as a common side effect of cisplatin (CDDP), which limits its clinical uses. Since oxidative injury and inflammatory response are the most pathological impact, estimation of natural antioxidant and anti-inflammatory agents like trans-ferulic acid (TFA) could protect against CDDP-induced testicular damage. In the current investigation, rats were assigned into four groups: normal, TFA (50 mg/kg/day, P.O), CDDP (10 mg/kg) as single intraperitoneal (I.P) injection at the end of the 5th day, and TFA+CDDP where TFA was administered 5 days before CDDP injection and 5 days after. Interestingly, TFA significantly restored testosterone levels and abrogated oxidative stress injury. Additionally, TFA effectively suppressed inflammatory cytokines. It also counteracted the inflammation via downregulation of TLR4 and IRF3, P38-MAPK, NF-κB-p65, JAK1, STAT3, ERK1, and ERK2. Besides, TFA can modulate AKT and p-AKT protein expressions. In parallel, TFA mitigated the histopathological aberration of the testis and prevented spermatogenesis disruption. On the other hand, TFA augmented the in vitro CDDP cytotoxicity on Caco-2 and MCF-7 cells. Interestingly, TFA enhanced the cytotoxic effect of CDDP via apoptosis induction in both the early and late stages of apoptosis. Collectively, TFA exhibited a potential protective effect against CDDP-induced testicular injury by inhibiting oxidative stress as well as TLR4/IRF3/INF-γ, P38-MAPK/NF-κB-p65/TNF-α, and JAK1/STAT-3/ERK1/2 inflammatory signaling pathways with enhancing its in vitro cytotoxic activity.
Показать больше [+] Меньше [-]Menadione sodium bisulfite alleviated chromium effects on wheat by regulating oxidative defense, chromium speciation, and ion homeostasis Полный текст
2021
Askari, Sajjad Hassan | Ashraf, Muhammad Arslan | Ali, Shafaqat | Rizwan, Muhammad | Rasheed, Rizwan
Menadione sodium bisulfite (MSB) is a crucial growth regulator mediating plant defense response. MSB-mediated regulation of defense mechanisms in wheat under chromium (Cr) toxicity has not been reported in the literature. Therefore, the present study was undertaken to appraise the efficacy of exogenous MSB on circumventing Cr phytotoxic effects on wheat. We also compared the effects of water-soluble MSB with that of water-insoluble menadiol diacetate (MD). The levels used in the present investigation for MSB and MD were 100 and 200 mg L⁻¹. Wheat plants grown in soil contaminated with 25 mg kg⁻¹ Cr in the form of K₂Cr₂O₇ showed a notable reduction in growth, chlorophyll molecules, relative water contents, grain yield, total soluble sugars, phenolics, flavonoids, ascorbic acid, activities of antioxidant enzymes (SOD, POD, CAT), and uptake of essential nutrients (K, P, and Ca). Cr toxicity caused a noticeable accretion in total free amino acids, proline, malondialdehyde, H₂O₂, O₂•⁻, relative membrane permeability, methylglyoxal contents, activities of enzymes (lipoxygenase, glutathione-S-transferase, and ascorbate peroxidase), nitric oxide and H₂S contents, glutathione and oxidized glutathione contents, total Cr contents, and Cr⁶⁺ and Cr³⁺ accumulation. MSB application significantly reduced lipid peroxidation, ROS overproduction, methylglyoxal levels, total Cr contents, and maintained higher Cr³⁺:Cr⁶⁺ ratio in aerial parts. Besides, Cr-mediated inhibition in essential nutrient uptake was significantly circumvented by exogenous MSB. Consequently, MSB enhanced wheat growth by lessening oxidative damage, total Cr contents in aerial parts, and strengthening antioxidant enzyme activities. MD was not effective in mediating defense responses in wheat under Cr toxicity.
Показать больше [+] Меньше [-]Impact of ambient temperature exposure on newborns with low Apgar scores in northwest China Полный текст
2021
Tang, Zezhong | Wu, Mingyang | Song, Guangrong | Yang, Rong | Wang, Youjie
In the context of global climate change, research efforts were focused on the association of ambient temperatures on maternal and neonatal health condition, but few have examined associations with low Apgar scores. From January 1, 2017, to December 31, 2018, all singleton deliveries of Ningxia Hui Autonomous Region were extracted from the Hospital Information System (N = 182,322). Daily temperature data were obtained from the official website of China Meteorological Administration. Low Apgar scores were defined as Apgar score ≤ 3 at 5 min in the present study. Logistic regression models were used to estimate the adjusted association between prenatal temperature exposure and low Apgar scores. Restricted cubic spline models were used to explore the dose-response relationship between temperature and low Apgar scores. The study population included 182,322 live singleton births, with 1575 (0.86%) cases of low Apgar scores. The elevated ambient temperature in different exposure timing windows in late pregnancy was associated with increased risk of low Apgar scores. As compared to moderate (10th–90th) temperature exposure, prenatal exposure to extreme hot (>90th) was associated with 13.9–47.0% increased risk of low Apgar scores, while non-significant relationship was found between extreme cold (<10th) exposure and low Apgar scores. The restricted cubic spline models showed a U-shaped relationship between prenatal temperature exposure and low Apgar scores (P for non-linearity < 0.05). Exposure to high ambient temperature during late pregnancy is associated with an increased risk of low Apgar scores in northwest China.
Показать больше [+] Меньше [-]Mapping annual land disturbance and reclamation in rare-earth mining disturbance region using temporal trajectory segmentation Полный текст
2021
Wu, Zhenbang | Li, Hengkai | Wang, Yuqing
Rare-earth mining has caused extensive damage to soil, vegetation, and water, significantly threatening ecosystems. Monitoring environmental disturbance caused by rare-earth mining is necessary to protect the ecological environment. A spatiotemporal remote sensing monitoring method for mining to reclamation processes in a rare-earth mining area using multisource time-series satellite images is described. In this study, the normalized difference vegetation index (NDVI) is used to evaluate the mining impact. Regression analysis is conducted to relate the HJ-1B CCD and Landsat 5/8 data to reduce the NDVI error related to sensor differences between different datasets. The analysis method of NDVI trajectory data of ground objects is proposed, and areas of environmental disturbance caused by rare-earth mining are identified. Pixel-based trajectories were used to reconstruct the temporal evolution of vegetation, and a temporal trajectory segmentation method is established based on the vegetation changes in different disturbance stages. The temporal trajectory of the rare-earth disturbance points is segmented to extract features in each stage to obtain the disturbance year, recovery year, and recovery cycle and evaluate the vegetation recovery after rare-earth mining disturbance. We applied the method to a stack of 20 multitemporal images from 2000 to 2019 to analyze vegetation disturbance due to rare-earth mining and vegetation recovery in the upper reaches of the Guangdong-Hong Kong-Macao Greater Bay Area, China. The results show the following. (1) Mining industry in the study area experienced rapid expansion before 2008, but growth slowed since the policies implemented by the government since 2009 to restrict rare-earth mining. (2) The continuous influence to the land caused by rare-earth mining can last for decades; however, the reclamation activities shorten the recovery cycle of mining land from 5 to 3 years.
Показать больше [+] Меньше [-]Antimicrobial activity of bacteria associated with the rhizosphere and phyllosphere of Avena fatua and Brachiaria reptans Полный текст
2021
Ali, Muskan | Walait, Sadia | Farhan Ul Haque, Muhammad | Mukhtar, Salma
Environmental pollution especially heavy metal-contaminated soils adversely affects the microbial communities associated with the rhizosphere and phyllosphere of plants growing in these areas. In the current study, we identified and characterized the rhizospheric and phyllospheric bacterial strains from Avena fatua and Brachiaria reptans with the potential for antimicrobial activity and heavy metal resistance. A total of 18 bacterial strains from the rhizosphere and phyllosphere of A. fatua and 19 bacterial strains from the rhizosphere and phyllosphere of B. reptans were identified based on 16S rRNA sequence analysis. Bacterial genera, including Bacillus, Staphylococcus, Pseudomonas, and Enterobacter were dominant in the rhizosphere and phyllosphere of A. fatua and Bacillus, Marinobacter, Pseudomonas, Enterobacter, and Kocuria, were the dominating bacterial genera from the rhizosphere and phyllosphere of B. reptans. Most of the bacterial strains were resistant to heavy metals (Cd, Pb, and Cr) and showed antimicrobial activity against different pathogenic bacterial strains. The whole-genome sequence analysis of Pseudomonas putida BR-PH17, a strain isolated from the phyllosphere of B. reptans, was performed by using the Illumina sequencing approach. The BR-PH17 genome contained a chromosome with a size of 5774330 bp and a plasmid DNA with 80360 bp. In this genome, about 5368 predicted protein-coding sequences with 5539 total genes, 22 rRNAs, and 75 tRNA genes were identified. Functional analysis of chromosomal and plasmid DNA revealed a variety of enzymes and proteins involved in antibiotic resistance and biodegradation of complex organic pollutants. These results indicated that bacterial strains identified in this study could be utilized for bioremediation of heavy metal-contaminated soils and as a novel source of antimicrobial drugs.
Показать больше [+] Меньше [-]AQI time series prediction based on a hybrid data decomposition and echo state networks Полный текст
2021
Liu, Hui | Zhang, Xinyu
A hybrid AQI time series prediction model is proposed based on EWT-SE-VMD secondary decomposition, ICA (imperialist competitive algorithm) feature selection, and ESN (echo state network) neural network. Firstly, EWT (empirical wavelet transform) and VMD (variational mode decomposition) are used to decompose the original AQI time series into several stable and reliable subseries. Then, the ICA is used to select features of the above subseries for the ESN prediction model. Finally, the optimized feature variables are put into the ESN deep network to establish a prediction model of each AQI subseries and obtain the future AQI index. According to the experimental results of the daily AQI series in Beijing, Tianjin, and Shijiazhuang, we find that (a) among all decomposition methods, the proposed secondary decomposition method (EWT-SE-VMD) performs best in processing data; (b) it is proved that the proposed hybrid model has broad application prospect and research value in the AQI prediction field.
Показать больше [+] Меньше [-]A review on efficient electromagnetic interference shielding materials by recycling waste—a trio of land to lab to land concept Полный текст
2021
Verma, Sarika | Mili, Medha | Dhangar, Manish | Jagatheesan, Krishnasamy | Paul, Sriparna | Bajpai, Harsh | Vedanti, Nimisha | Mallik, Jyotirmoy | Khan, Mohammed Akram | Bhargaw, Hari Narayan | Hashmi, Sayed Azhar Rasheed | Srivastava, Avanish Kumar
The materials used in electrical and electronic applications have great importance and broader applications, but they have severe electromagnetic interference (EMI). These materials have extensive applications in broadcasting, medical industries, research, defence sectors, communication and similar fields. The EMI can be addressed by using effective EMI shielding materials. This review presents a detailed, comprehensive description for making electromagnetic interference shielding material by recycling various wastes. It starts with highlighting the overview of electromagnetic interference shielding (EMI) and its theoretical aspects. It provides a comprehensive and detailed understanding of recent trends in the novel approaches towards fabricating EMI shielding from industrial waste, agricultural waste and other miscellaneous wastes. This paper critically reviews the works related to the recycling of wastes like red mud (waste from the aluminium refining industry), ground tyre rubber, tea waste (biowaste) from tea industries, bagasse (waste from sugar cane industry), peanut and hazelnut shells (agricultural waste), waste tissue paper and polyethylene and other miscellaneous wastes like hydrocarbon carbon black and ash for the fabrication of highly effective electromagnetic (EM) interference shielding materials. Highly effective results have been reported using red mud showing maximum efficiency of 51.4 dB in X-band range, various agricultural waste displaying reflection loss of up to − 87.117 dB (in the range 0.01 to 20 GHz) and miscellaneous waste giving EMI SE of 80 dB in X-band frequency. A separate section is dedicated to emphasizing future work and recommendations.
Показать больше [+] Меньше [-]Increased expression of apoptotic markers in human full-term placenta after exposure to elevated environmental cadmium levels during pregnancy Полный текст
2021
Phuapittayalert, Laorrat | Tanasrivaroottanun, Nathamon | Hipkaeo, Wiphawi | Supanpaiboon, Wisa | Sakulsak, Natthiya
Cadmium (Cd), a toxic heavy metal, produces various forms of environmental contaminations and health problems in human. In this study, we aimed to examine the localization of several apoptotic markers in human placentas from pregnant women who were environmentally exposed to Cd. Twelve pregnant women participated in this analysis and they were divided into 2 groups according to their living areas: high-Cd (H-Cd) and low-Cd (L-Cd) groups. After delivery, the placentas were immediately harvested, and the placental width, length, and weight were measured. The placental Cd concentration was determined by using ICP-MS. The expression of three apoptotic markers, cleaved caspase-3, cleaved lamin A/C, and TUNEL, was examined in immunohistochemistry. In results, the placental Cd concentration in the H-Cd group was higher than that in the L-Cd group. In contrast, a significant decrease in the BW (birth weight):PW (placenta weight) ratio representing the placental nutrient transport function was found in the H-Cd group, and an inverse correlation between placental Cd concentration and BW:PW ratio was demonstrated. Additionally, significant elevations in the expression of cleaved caspase-3, cleaved lamin A/C proteins, and TUNEL were shown in the H-Cd placenta. Moreover, positive correlations were found between the placental Cd concentration and the expression of cleaved caspase-3 and TUNEL. Collectively, our findings suggest that the exposure of pregnant women to environmental Cd might induce Cd to be transferred to the body and then accumulated in the placenta, resulting in disturbance of the placental function and eventual apoptosis.
Показать больше [+] Меньше [-]Mitigation of yield-scaled greenhouse gas emissions from irrigated rice through Azolla, Blue-green algae, and plant growth–promoting bacteria Полный текст
2021
Malyan, Sandeep K. | Bhatia, Arti | Tomer, Ritu | Harit, Ramesh Chand | Jain, Niveta | Bhowmik, Arpan | Kaushik, Rajeev
Irrigated transplanted flooded rice is a major source of methane (CH₄) emission. We carried out experiments for 2 years in irrigated flooded rice to study if interventions like methane-utilizing bacteria, Blue-green algae (BGA), and Azolla could mitigate the emission of CH₄ and nitrous oxide (N₂O) and lower the yield-scaled global warming potential (GWP). The experiment included nine treatments: T₁ (120 kg N ha⁻¹ urea), T₂ (90 kg N ha⁻¹ urea + 30 kg N ha⁻¹ fresh Azolla), T₃ (90 kg N ha⁻¹ urea + 30 kg N ha⁻¹ Blue-green algae (BGA), T₄ (60 kg N ha⁻¹ urea + 30 kg N ha⁻¹ BGA + 30 kg N ha⁻¹ Azolla, T₅ (120 kg N ha⁻¹ urea + Hyphomicrobium facile MaAL69), T₆ (120 kg N ha⁻¹ by urea + Burkholderia vietnamiensis AAAr40), T₇ (120 kg N ha⁻¹ by urea + Methylobacteruim oryzae MNL7), T₈ (120 kg N ha⁻¹ urea + combination of Burkholderia AAAr40, Hyphomicrobium facile MaAL69, Methylobacteruim oryzae MNL7), and T₉ (no N fertilizer). Maximum decrease in cumulative CH₄ emission was observed with the application of Methylobacteruim oryzae MNL7 in T₇ (19.9%), followed by Azolla + BGA in T₄ (13.2%) as compared to T₁ control. N₂O emissions were not significantly affected by the application of CH₄-oxidizing bacteria. However, significantly lower (P<0.01) cumulative N₂O emissions was observed in T₄ (40.7%) among the fertilized treatments. Highest yields were observed in Azolla treatment T₂ with 25% less urea N application. The reduction in yield-scaled GWP was at par in T₄ (Azolla and BGA) and T₇ (Methylobacteruim oryzae MNL7) treatments and reduced by 27.4% and 15.2% in T₄ and T₇, respectively, as compared to the T₁ (control). K-means clustering analysis showed that the application of Methylobacteruim oryzae MNL7, Azolla, and Azolla + BGA can be an effective mitigation option to reduce the global warming potential while increasing the yield.
Показать больше [+] Меньше [-]