Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Hum Vaccin Immunother ; 20(1): 2309699, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38310646

RESUMO

The coronavirus disease 2019 (COVID-19) caused several impacts. Focusing on 360 participants (178 males, 182 females), this study explored the association between COVID-19 related distress, risk perception, stigma, and vaccine hesitancy and acceptance in the general population. Measures used included the Hospital Anxiety and Depression Scale (HADS) and COVID Stress Scale (CSS) to evaluate anxiety, depression, and COVID-19 related distress, the COVID-19 Risk Perception Scale and COVID-19 Stigma Discrimination Scale to assess risk perception and stigma, and the Oxford COVID-19 Vaccine Hesitancy Scale and Vaccine Acceptance Instrument to measure vaccine hesitancy and acceptance. The findings revealed that 66.9% of participants exhibited vaccine hesitancy, and stress and risk perception were significant predictors of both vaccine hesitancy and acceptance, even after controlling for demographic factors. This study highlights the importance of understanding the factors mentioned above that will contribute to vaccine hesitancy and acceptance, which will contribute to promoting vaccine acceptance.


Assuntos
COVID-19 , Feminino , Masculino , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Paquistão/epidemiologia , Vacinas contra COVID-19 , Hesitação Vacinal , Percepção , Vacinação
2.
Environ Sci Pollut Res Int ; 31(10): 15339-15347, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38294656

RESUMO

Soil contaminated with heavy metals cause serious threat to the soil quality, biota, and human. The removal or stabilization of heavy metals through plants is an environment friendly approach. The aim of study was to assess the potential of Celosia argentea L. for the phytoremediation of heavy metals contaminated soil. Soil was spiked with different levels (0, 100, 200, 300, and 400 mg/kg) of chromium (Cr), copper (Cu), lead (Pb), and Zn (Zn). Experiment was carried out in greenhouse and impact of heavy metals was evaluated on plant by assessing the germination rate and plant growth. To evaluate either plant has potential to extract/stabilize the heavy metals, concentration in roots and shoot, translocation factor (TF), bioconcentration factor (BCF), and bioaccumulation factor (BAF) were determined. Application of heavy metals significantly affected the germination rate and minimum (26.6%) was observed in Cr spiked soil (400 mg/kg). Moreover, the biomass of C. argentea was also affected by the application of heavy metals. However, the concentration of heavy metals in roots and shoots were low. The BCF and BAF of C. argentea was lower than 1 except at lower levels of Pb and Zn, but the TF was greater than 1. The TF showed that plants have capability to transfer heavy metals to shoots once they are taken up by roots. However, based on the BCF and concentrations of heavy metals in shoots, it is evident that plant could play important role in the phytostabilization of heavy metals polluted soil.


Assuntos
Celosia , Metais Pesados , Poluentes do Solo , Humanos , Biodegradação Ambiental , Solo , Chumbo , Poluentes do Solo/análise , Metais Pesados/análise , Cromo , Plantas
3.
J Environ Manage ; 348: 119435, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37890401

RESUMO

Phytoremediation of lead (Pb) contaminated soil is a green technology to reduce Pb exposure and root exudates-derived organic acids play a vital role in this treatment process. In this study, Pb hyperaccumulator Pelargonium hortorum was chosen to investigate root-induced organic acid secretions and their subsequent role in Pb phytoextraction. In the first step, root exudation of P. hortorum was investigated in hydroponic experiments (0.2X Hoagland solution) under control and Pb stress conditions. Possible chemical interactions between Pb and the observed root exudates were then analyzed using Visual MINTEQ modeling. In the next step, the effects of the exogenous application of organic acids on Pb phytoextraction and soil enzymatic activities were studied in a pot experimental setup. Results indicated significant exudation of malic acid > citric acid > oxalic acid > tartaric acid in root exudates of P. hortorum under 50 mg L-1 Pb. Visual MINTEQ modeling results revealed that organic acids directly affect Pb dissolution in the nutrient solution by modulation of solution pH. Experimental results revealed that malic acid and citric acid significantly increased available Pb contents (7.2- and 6.7-folds) in the soil with 1500 mg kg-1 Pb contamination. Whereas, in shoot and root, the highest increase in Pb concentration was observed with citric acid (2.01-fold) and malic (3.75-fold) supplements, respectively. Overall, Pb uptake was notably higher when malic acid was applied (2.8-fold) compared to other organic acids, followed by citric acid (2.7-fold). In the case of soil enzymatic activities, oxalic acid significantly improved dehydrogenase, alkaline phosphatase, and microbial biomass by 1.6-, 1.4- and 1.3-folds, respectively. The organic acids were successful in reviving enzyme activity in Pb-contaminated soil, and might thus be used for long-term soil regeneration.


Assuntos
Chumbo , Poluentes do Solo , Solo , Ácido Cítrico , Biodegradação Ambiental , Oxalatos , Poluentes do Solo/análise
4.
Environ Sci Pollut Res Int ; 30(40): 92817-92829, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37493912

RESUMO

Globally agrochemicals are widely used in the agricultural sectors, posing potential eco-toxicological risks and disrupting various lifeforms including birds. Thus, the current work was conducted to compare the acute toxic impacts of pesticides (e.g., chlorpyrifos, acetamiprid, and lambda-cyhalothrin) on the pigeon's health. In total 50 adult pigeons were purchased from a local market where these pigeons were fed on pollution-free food. Post adaptation period (15 days), the pigeons were arbitrarily separated into five distinct groups after having been identified in this manner by chance (each group containing 10 pigeons). Control group (group 1) was not treated with any pesticide while the remaining groups (groups 2, 3, and 4) were treated with 0.25-mg/kg body weight of chlorpyrifos, acetamiprid, lambda-cyhalothrin, and a mixture of all three pesticides (group 5), respectively. After 36 days of exposure, the groups that had been exposed to the pesticide showed a significant (p < 0.05) increase in both the total number of platelets and the number of white blood cells (WBCs), in comparison to the control group. On the other hand, the groups that were exposed to the insecticides had significantly lower levels of red blood cells (RBCs), hemoglobin (Hb), and packed cell volume (PCV) (p < 0.05). The value of mean corpuscular volume (MCV) was significantly (p < 0.05) reduced in acetamiprid-exposed group, while a significant increase was observed in other pesticide-exposed groups. Obvious histopathological changes were observed in the tissues of control group and no such changes were reported by control group. Necrosis, pyknosis, lymphocyte infiltration, congestion of blood, dissolution of plasma membrane, and vacuolation were observed in the livers of pesticide-treated pigeons. The intestinal study showed the formation of goblet cells, villi rupturing, degeneration of serosa, necrosis, and pyknosis in treated groups. Renal alterations, dilation of renal tubules, reduction of glomerulus tissue, and edema were observed. This study manifests that the uncontrolled use of pesticides impairs ecosystems and poses a substantial health risk to wildlife and ultimately to human.


Assuntos
Clorpirifos , Inseticidas , Praguicidas , Animais , Humanos , Clorpirifos/toxicidade , Columbidae , Ecossistema , Inseticidas/toxicidade , Praguicidas/toxicidade , Necrose
5.
J Pak Med Assoc ; 73(4): 944-946, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37052025

RESUMO

World Health Organization data indicates a marked rise in global obesity, with approximately 30% of the world's population classified as overweight or obese. The contributory factors include unhealthy dietary habits, lack of physical activity, urbanization, and technology dependent sedentary lifestyle. Among the various management approaches, cardiac rehabilitation has evolved from an exercise-only programme for patients with cardiac diseases to a multi-disciplinary individualised intervention plan for risk factor modification, primary and secondary prevention of cardiometabolic diseases. Evidence suggests that visceral obesity is an independent risk factor of morbidity and mortality from cardiometabolic causes. There are multiple training programmes targeting visceral fat oxidation, one of which is high intensity interval training. It appears to be a promising regime, inducing metabolic adaptations in the body. This review summarizes the multidisciplinary cardiac rehabilitation services for the management of visceral adiposity and generalised obesity, its under-utilization and scarcity of local published data, highlighting the need for future research.


Assuntos
Reabilitação Cardíaca , Cardiopatias , Humanos , Obesidade Abdominal , Obesidade/epidemiologia , Sobrepeso
6.
Environ Sci Pollut Res Int ; 30(12): 32673-32682, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36469272

RESUMO

The main aim of the present study was to assess the removal of cadmium (Cd) from contaminated soil by using Pelargonium × hortorum - an ornamental plant. Furthermore, the genotoxic impacts of Cd on plant was evaluated, and accumulated Cd in shoots were recovered as Cd-nanoparticles. For this purpose, a pot experiment was carried out with Cd (0-150 mg/kg) spiked soil. P. hortorum was grown for 24 weeks in a greenhouse. Subsequently, harvested root/shoot biomass and Cd concentration in root/shoot were determined. The micronucleus assay was performed to assess the genotoxicity of Cd within the selected plant. Accumulated Cd in shoots was recovered as Cd-nanoparticles and was characterized by SEM and XRD. Exposure to Cd exhibited a phytotoxic impact by reducing the plant biomass, but plant survived at higher Cd concentrations and the tolerance index was greater than 60% at a higher Cd level (150 mg/kg). Moreover, 257 mg/kg of Cd in aerial parts was observed, and maximum Cd uptake (120 mg plant-1) by P. hortorum was found at 150 mg/kg Cd. Plants exposed to Cd exhibited genotoxic impact by increasing the number of micronuclei by 59% at a higher Cd level (150 mg/kg) and the mitotic index was reduced by 20%. Furthermore, recovered nanoparticles were spherically shaped with an average size of 36.2-355 nm. The plant has potential for the removal of Cd and has exhibited good tolerance.


Assuntos
Pelargonium , Poluentes do Solo , Cádmio/análise , Poluentes do Solo/análise , Biodegradação Ambiental , Metais , Plantas , Solo , Biomassa , Raízes de Plantas/química
7.
Front Psychol ; 13: 915290, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35967642

RESUMO

During the initial phases of the COVID-19 pandemic, stress and anxiety were pervasive among the masses due to high morbidity and mortality. Besides the fear of coronavirus was also particularly driven by social media. Many people started to look for faith and spiritual connections to gain comfort. The role of spiritual ties and religious beliefs in relation to coping with pandemic stress has acquired the attention of researchers in some parts of the world. This cross-sectional survey aimed at assessing the intensity of stress and anxiety symptoms experienced by people and how much they were alleviated by employing spiritual connections. The study sample comprises 795 respondents with 52% males and 48% females living in Saudi Arabia. The brief online study questionnaire collected data about background variables, anxiety and stress scale from DASS-21, and items from the WHOQOL (SRBP) instrument assessed the use of spiritual beliefs to cope. Multiple regression models were tested to determine the role of spiritual connections after adjusting demographic variables. Results illustrated that after adjusting for gender and age, participants' anxiety symptoms decreased by (ß = -0.27; p = 0.000) units with each unit increase in the use of spiritual connections, and participants' stress symptoms reduce by (ß = -0.36; p = 0.000) units with each unit increase in coping with spirituality. Additionally, females' risk to experience anxiety and stress symptoms was more than males [(ß = 0.88; p = 0.01) and (ß = 0.92; p = 0.000)], respectively. An increase in age decreases the likelihood of experiencing anxiety symptoms and stress symptoms by (ß = -0.75; p = 0.02) and (ß = -0.11; p = 0.000) units, respectively. Findings support the protective role of spiritual connections despite small beta coefficients. The social and cultural context in Saudi Arabia favors deep-rooted connections with spirituality and faith. Our findings support the fact that the reliance on spiritual connections helped older people to deal with exaggerated fear during the initial phase of the COVID-19 pandemic and reduces the risk of experiencing anxiety and stress symptoms. Females and younger participants were relatively vulnerable to developing these symptoms. We discussed these findings considering some recent studies that reported similar relationships and made recommendations for future research.

8.
RSC Adv ; 12(7): 3883-3891, 2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35425466

RESUMO

Two-dimensional (2D) monolayer nanomaterials are the thinnest possible membranes with interesting selective permeation characteristics. Among two-dimensional materials, graphenes and hexagonal boron nitride (h-BN) are the most promising membrane materials, which can even allow the separation of proton isotopes. The current work aims at understanding the higher reported permeability of h-BN by sequential doping of B and N atoms in graphene nanoflakes. The kinetic barriers were calculated with two different models of graphenes; coronene and dodecabenzocoronene via zero-point energy calculations at the transition state for proton permeability. The lower barriers for h-BN are mainly due to boron atoms. The trends of kinetic barriers are B < BN < N-doped graphenes. The permeation selectivity of graphene models increases with doping. Our studies suggest that boron-doped graphene models show an energy barrier of 0.04 eV for the permeation of proton, much lower than that of the model graphene and h-BN sheet, while nitrogen-doped graphenes have a very high energy barrier up to 7.44 eV for permeation. Therefore, boron-doped graphene models are suitable candidates for proton permeation. Moreover, the presence of carbon atoms in the periphery of BN sheets has significant negative effects on the permeation of proton isotopes, an unexplored dimension of the remote neighboring effect in 2-D materials. This study illustrates the need for permeation study through other hetero-2D surfaces, where interesting hidden chemistry is still unexplored.

9.
Chemosphere ; 287(Pt 1): 131937, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34454226

RESUMO

Abbottabad is a famous tourist destination due to its greenery and location. However, rapid increase in population and unplanned urbanization cause various environmental problems. Among different environmental stress, vehicular emission is the major issue for the survival and sustainability of plant species. This study aimed to investigate the effects of atmospheric pollution (caused by vehicular emission) on the anatomical, biochemical and morphological aspects of plant species present alongside the roads of Abbottabad, Pakistan. The plants were also collected from control sites (away from road-sites) for comparison. The results showed that various morphological characteristics of plant species including petiole length, vein-to-vein difference between leaves and length to breadth ratio of leaves were adversely affected by air pollution. The stomatal index varies in plant species because of variations in the numbers of epidermal cells. The air pollution tolerance index (APTI) of plant leaves from contaminated areas was reported to be higher as compared to control (non-contaminated) areas. Consequently, the findings from this study confirmed that plant species growing alongside of Abbottabad roads has greater tolerance than plant species growing in solitude areas away from road sites (control sites). Among different studied plants, Juglans regia, Morus nigra, Xanthium strumarium, Prunus armenica, Diospterus lotus and Populus ciliata have highest APTI and found to be more suitable for plantation in Abbottabad.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental , Folhas de Planta/química , Emissões de Veículos/análise , Emissões de Veículos/toxicidade
10.
Chemosphere ; 277: 130243, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34384172

RESUMO

Improving phytoremediation efficiency in lead (Pb) contaminated soil through either bacterial or fungal inoculants have extensively been studied with different successes and limitations. In this study, co-application of bacteria and fungi have been investigated for development of an integrated phytoremediation system (IPS) for efficient Pb removal and restoration of soil microbial and enzymatic activities in degraded soil. For this purpose, Pb tolerant bacterial and fungal strains were firstly analyzed for antifungal and antibacterial activities through disc diffusion method. Afterwards, the co-inoculation studies were performed to investigate the effects on phytoavailability and uptake of Pb by Pelargonium hortorum through soil incubation and pot culture experiments, respectively. Results indicated significant (p < 0.05) antibacterial activity of Mucor spp. against bacterial species (Klebsiella variicola and K. quasipneumoniae). The highest significant increase in extractable Pb fraction (5.0-folds) was observed when soil was co-inoculated with Aspergillus flavus + Microbacterium paraoxydans compared to the control soil (un-inoculated soil) at 2000 mg Pb kg-1 concentration. Similarly, uptake results also indicated significantly higher Pb uptake in plants inoculated with A. flavus + M. paraoxydans. Soil microbial results indicated significant decrease in microbial health indicators and enzymatic activities with increasing Pb concentration and exposure time, as compared to control soil. A relatively severe decline was observed in soil respiration and dehydrogenase (DEH) activities by 2.8- and 2.5-folds, respectively at 2000 mg Pb kg-1 of soil. The optimized IPS was effective for restoring enzymatic activities in Pb contaminated soil and could be applied for sustainable restoration of Pb contaminated soil.


Assuntos
Poluentes do Solo , Solo , Biodegradação Ambiental , Klebsiella , Chumbo , Microbiologia do Solo , Poluentes do Solo/análise
11.
Environ Pollut ; 287: 117667, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34426392

RESUMO

Cadmium (Cd) and lead (Pb) are ubiquitously present in surface soils, due to anthropogenic activities, causing threat to ecological and human health because of their carcinogenic nature. They accumulate in large quantities in the environment and affect negatively soil microbiota, plants, animals, and humans. For the cleanup of Cd/Pb polluted soils, different plant species have been studied. Many plants have shown the potential to hyperaccumulate Cd/Pb in their above-ground tissues. These plants decrease soil pH by root exudation or by releasing H+ ions, and this, in turn, increases the bioavailability of Cd/Pb for plant uptake. Different environmental processes related to soil organic matter, microorganisms, pH, genetic modifications, and various soil-borne chelating agents affect the potential of phytoremediation technology. Review papers trying to identify a single factor influencing the phytoremediation of heavy metals are available in the literature. However, an integrated approach dealing with different factors involved in the remediation of both metals is scarcely discussed. The main focus of this review is to discuss the phytoextraction technique for Cd/Pb removal from contaminated sites along with detoxification mechanisms. Further, the challenges in the Cd/Pb phytoextraction and different options available to cope with these challenges are also discussed. The update on the relevant findings on the use of microorganisms and amendments in enhancing the Cd/Pb phytoextraction is also provided. Finally, the areas to be explored in future research for the removal of Cd/Pb by integrated strategies have been discussed.


Assuntos
Cádmio , Poluentes do Solo , Biodegradação Ambiental , Cádmio/análise , Humanos , Chumbo , Solo , Poluentes do Solo/análise
12.
3 Biotech ; 11(4): 169, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33816046

RESUMO

In this modern era, medicine is facing many alarming challenges. Among different challenges, antibiotics are gaining importance. Recent years have seen unprecedented increase in knowledge and understanding of various factors that are root cause of the spread and development of resistance in microbes against antibiotics. The infection results in the formation of microbial colonies which are termed as biofilms. However, it has been found that a multiple factors contribute in the formation of antimicrobial resistance. Due to higher dose of Minimum Bactericidal Concentration (MBC) as well as of Minimum Inhibitory Concentration (MIC), a large batch of antibiotics available today are of no use as they are ineffective against infections. Therefore, to control infections, there is dire need to adopt alternative treatment for biofilm infection other than antibiotics. This review highlights the latest techniques that are being used to cure the menace of biofilm infections. A wide range of mechanisms has been examined with particular attention towards avenues which can be proved fruitful in the treatment of biofilms. Besides, newer strategies, i.e., matrix centered are also discussed as alternative therapeutic techniques including modulating microbial metabolism, matrix degrading enzyme, photodynamic therapy, natural compounds quorum sensing and nanotechnology which are being used to disrupt extra polymeric substances (EPS) matrix of desired bacterial biofilms.

13.
Ecotoxicol Environ Saf ; 215: 112149, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33773153

RESUMO

The aim of present work was to evaluate the effects of titanium dioxide nanoparticles (TiO2 NPs) on rice's growth (Oryza sativa L.) and nutrient availability under different soil textures. Greenhouse experiment was carried out with three soil textures (sandy loam, silt loam and silty clay loam) and two concentrations of TiO2 NPs (500, 750 mg kg-1). Control (without TiO2 NPs) was also maintained for the comparison. Growth parameters including chlorophyll content, root/shoot length, fresh/dry biomass and nutrients' uptake including calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), phosphorous (P), potassium (K) and zinc (Zn) were determined. The results revealed that application of 500 mg kg-1 TiO2 NPs in silty clay loam soil increased the chlorophyll content (3.3-folds), root length (49%), shoot length (31%), root and shoot biomass (41% & 39%, respectively) as compared to other soil textures. The maximum plant growth was observed in silty clay loam > silt loam > sandy loam. Concentration of Cu, Fe, P and Zn in shoot was increased by 8 - , 2.3 - , 0.4 - , 0.05 -folds in silty clay loam upon 500 mg kg-1 TiO2 NPs application as compared to the control. Backward selection method to model the parameters (nutrients in soil) for the response variables (root/shoot length and biomass) showed that Ca, Fe, P are the main nutrients responsible for the increase in plant length and biomass. Overall, the growth of rice was better in silty clay loam at 500 mg kg-1 of TiO2 NPs.


Assuntos
Oryza/fisiologia , Poluentes do Solo/metabolismo , Transporte Biológico , Biomassa , Argila , Nanopartículas , Compostos Orgânicos , Oryza/crescimento & desenvolvimento , Fósforo , Desenvolvimento Vegetal , Solo , Poluentes do Solo/análise , Titânio
14.
Ecotoxicol Environ Saf ; 213: 111977, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33578101

RESUMO

The present study focused on investigating the effect of titanium dioxide nanoparticles (TiO2NPs) on rice (Oryza sativa L.) growth and changes in soil health in two contrasting soil textures (silt-loam and clay). Moreover, response of rice to different methods of TiO2NPs application and phosphorous fertilizer levels were also evaluated. For toxicity assessment, pot experiment was carried out. TiO2NPs (0, 500, 750 mg kg-1) were applied and plants were grown till vegetative stage. After harvesting, physiological parameters, stress assay, soil microbial and enzymatic activities were determined. Based on the results of toxicity study, impact of three methods of TiO2NPs application (foliar, irrigation, soil) and four phosphorous fertilizer levels (0, 10, 20, 40 mg kg-1) on rice growth were assessed. During the 1st phase, results showed an adverse effect of TiO2NPs on plant growth and soil microorganisms in both soil textures at 750 mg kg-1. The H2O2 production, lipid peroxidation and leaf membrane injury index were increased by 4.3-, 2.4-, and 1.9-folds in clay soil upon 750 mg kg-1 TiO2NPs application. Likewise, at the same level of TiO2NPs; microbial biomass, dehydrogenase, and respiration were decreased by 0.91-, 0.79-, and 0.78- folds respectively. In 2nd phase, maximum shoot length, biomass, phosphorous uptake and rice grain protein content were observed under application of TiO2NPs (500 mg kg-1) through irrigation method in combination with 40 mg P kg-1. However, 20 and 40 mg P kg-1 performed equally well upon TiO2NPs application and the results were not statistically significant. The results suggest that 750 mg kg-1 of TiO2NPs negatively affect plant growth and soil enzymatic activities. Moreover, combined application of TiO2NPs (500 mg kg-1) through irrigation and 20 mg P kg-1 is recommended to be the optimum for growth of rice plant.


Assuntos
Oryza/fisiologia , Fósforo/metabolismo , Poluentes do Solo/toxicidade , Titânio/metabolismo , Biomassa , Argila , Peróxido de Hidrogênio/metabolismo , Nanopartículas , Oryza/metabolismo , Desenvolvimento Vegetal , Folhas de Planta/metabolismo , Solo , Poluentes do Solo/análise
15.
J Hazard Mater ; 409: 124442, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33168309

RESUMO

Accumulation of arsenite [As(III)] and dimethylarsinic acid (DMA) in rice grainsposes a threat to human health. Although silicon (Si) has been reported to reduce As uptake, the mechanisms involved are not fully understood. In this study, we first confirmed that the concurrent addition of Si and As in solution decreased As accumulation in rice. Then, the effect of Si previously deposited in shoots by the pretreatment of rice seedlings with Si for one week was investigated by using lsi2 mutant and its wild type. The uptake of both As(III) and DMA decreased in rice subjected concurrently to Si and As (III)/DMA in solution, without effects on OsLsi1 and OsLsi2 expression. This concurrent treatment also decreased total As concentration in the root cell walls and xylem sap, which might have restrained apoplastic transport of As to shoots. Silicon previously deposited in the shoots decreased root-to-shoot As(III) translocation and down-regulated OsLsi1, OsLsi2 and OsNRAMP1, but did not affect As concentration in the roots, and had no effect on DMA uptake and accumulation in shoots and roots either. This study sheds light on the role of silicon in solution and rice shoots in As(Ⅲ) and DMA uptake and transport by rice.


Assuntos
Arsenitos , Oryza , Ácido Cacodílico , Humanos , Raízes de Plantas , Silício
16.
Chemosphere ; 258: 127405, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32947677

RESUMO

Chelation of lead (Pb) is an important factor in enhancing the Pb mobility thereby improving availability to promote phytoremediation of Pb from contaminated soil. The study was conducted to evaluate the effect of amendments in enhancing the phytoremediation of Pb in soil. For this purpose, soil was spiked to obtain desired Pb concentrations (0-1500 mg kg-1) and pots were filled. One month old and uniform seedlings of Pelargonium hortoum were transplanted into each pot. Five different amendments i.e. compost (0-10%), ammonium nitrate (0-10 mmol kg-1), TiO2NPs (0-100 mg kg-1), citric acid (0-10 mmol kg-1) and EDTA (0-5 mmol kg-1), were applied. Overall, ammonium nitrate, EDTA and citric acid application increased the Pb concentration, however, compost and TiO2NPs decreased the concentration in roots and shoots. At 1500 mg Pb kg-1, Pb concentration in shoots was increased by 0.9-, 0.6- & 0.8-folds and in roots by 1.8-, 1.3- & 1.7-folds upon EDTA, ammonium nitrate and citric acid application, respectively. TiO2NPs and compost application decreased Pb concentration by 29% & 35% in shoots and 25% & 51% in roots, respectively. At the highest level of Pb (1500 mg kg-1), plant biomass was increased by 26.6%, 19.5%, 17.9% and 18.4% upon application of compost, TiO2 NPs, ammonium nitrate and citric acid, respectively. However, EDTA reduced the plant dry biomass by 28.4%. The accumulated Pb content was recovered as Pb-nanoparticles, which were in anatase phase, size ranged between 98 and 276 nm. Among all the studied amendments, citric acid efficiently increased Pb phytoaccumulation without any toxicity.


Assuntos
Biodegradação Ambiental , Chumbo/análise , Poluentes do Solo/análise , Biomassa , Quelantes , Ácido Cítrico , Compostagem , Ácido Edético , Chumbo/metabolismo , Pelargonium , Raízes de Plantas , Solo , Poluentes do Solo/metabolismo
17.
Sci Total Environ ; 748: 141496, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32818897

RESUMO

Soil amendments like ethylene-diamine-tetraacetic-acid (EDTA) have extensively been used for enhancing lead (Pb) phytoextraction. But due to its toxic effects, environment friendly substitute is required. Therefore, the present study was conducted to investigate the effect of EDTA and Di-iso-propanol-amine (DIPA) to enhance Pb phytoavailability and uptake by Pelargonium hortorum along with comparative toxicities of both organic amendments. For this purpose, soil was spiked with Pb concentrations (0, 500, 750, 1000 and 1500 mg kg1) and amended with EDTA and DIPA at dosage levels (0, 1.5, 3, 5, 7.5, 10 mmol kg-1) for plantation of Pelargonium hortorum. Soil samples were extracted with MgCl2, plant samples were acid digested and analyzed for metal content. Biomass and root/shoot length of Pelargonium hortorum was decreased with increase in concentration of Pb and chelating agents. Phytoavailability of Pb at 1500 mg kg-1 with EDTA 10 mmol kg-1 was 0.3-folds in comparison to DIPA at the same dosage. Pelargonium hortorum plants amended with EDTA and DIPA at 10 mmol kg-1 with Pb 1000 mg kg-1 were found to uptake Pb 5.3-fold and 2.5-folds, respectively in comparison to Pb 1000 mg kg-1 alone. Pb uptake decreased at 1500 mg kg-1 with both chelating agents. The EDTA alone and in combination with 1500 mg Pb kg-1 showed maximum genotoxicity by reducing the mitotic index and increasing the micronuclei formation. EDTA+Pb showed maximum toxicity followed by Pb and DIPA. Overall, 10 mmol kg-1 of EDTA and DIPA performed better among all dosages in enhancing phytoavailability and uptake of Pb. DIPA showed less toxicity than that caused by EDTA, with comparable ability to promote Pb phytoextraction.


Assuntos
Pelargonium , Poluentes do Solo , 1-Propanol , Biodegradação Ambiental , Quelantes , Ácido Edético , Chumbo/toxicidade , Propanóis , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
18.
Chemosphere ; 258: 127353, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32554014

RESUMO

Extensive use of antibiotic results in significant antibiotics pollution in the environment. Main objective of this study was to gain insight into potential impacts of antibiotics on plant physiological growth and nutritional composition, and stress alleviation through application of different organic amendments. Effects of five antibiotics (ciprofloxacin, levofloxacin, ofloxacin, amoxicillin and ampicillin) were observed in the presence of three organic amendments (rice husk, farmyard manure and poultry litter) with rice (Oryza sativa L.) as a model plant. Organic amendments were mixed with soil (@ 5 g kg-1) and after three weeks, antibiotics were applied (@10 mg kg-1) and plants were allowed to grow for four months. After which plants were harvested and physical growth parameters (root/shoot length, biomass) and nutritional composition (grain protein content, carbohydrates, phosphorous and iron) were monitored. It was observed that germination rate, seedling root/shoot length, seedling biomass and vigor index were negatively impacted. The application of organic amendments alleviated antibiotic stress on seedling dry biomass, length and vigor index by 1.8-, 3.1- and 2.5-folds, respectively as compared to the antibiotic controls. Concentrations of phosphorous, iron, carbohydrates and proteins were decreased by 5.3-, 1.3-, 1.4- and 1.6-folds upon application of antibiotics. Rice husk was the most effective treatment in case of physical growth parameters and alleviating antibiotics' induced genotoxicity. Whereas, poultry litter had the highest positive effect on nutritional composition of plants. In general, the application of organic amendments alleviated the phytotoxicity as well as genotoxicity in plants under antibiotics stress.


Assuntos
Antibacterianos/toxicidade , Oryza/fisiologia , Poluentes do Solo/toxicidade , Antibacterianos/metabolismo , Biomassa , Poluição Ambiental , Germinação , Esterco , Oryza/metabolismo , Plântula/metabolismo , Solo , Poluentes do Solo/análise
19.
Microsc Res Tech ; 83(9): 1124-1131, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32394528

RESUMO

The Cobalt Oxide and Calcium-Aluminum Oxide nano-catalysts were analyzed using Scanning Electronic Microscopy (SEM), X-ray diffraction (XRD), and dispersive X-ray spectroscopy (EDX) techniques. Preliminary results showed that the particles of Cobalt Oxide exhibit sponge like morphology and homogenous distribution as per confirmation via SEM. Its average particle size ranges to 30.6 nm demonstrating enormous number of pores and aggregative in nature. Its various peaks were ranging from 19.2 to 65.4 after XRD analysis. The highest intensity was observed at 36.9 position. The energy dispersive spectroscopy techniques were used to calculate the elements present in sample according to their weight and atomic percentage. The cobalt oxide contain cobalt as the most abundant element with 46.85 wt% and 18.01 atomic percent. It contain oxygen with 30.51 wt% and 43.19 atomic percent. Whereas, SEM of calcium aluminum oxide showed random morphology. According to the calculation of Scherrer equation regarding XRD analysis, it was distributed homogenously with particle size ranges from 30 to 40 nm. Its porous morphology was due to the interconnecting gaps between different particles. It result the eight peaks ranging from 18.1 to 62.7 in XRD spectrum. The highest intensity observed at 35.1 with average crystallite particle size of 25.6 nm. The calcium aluminum oxide contain aluminum 7.45 wt% and 6.93 atomic percent. The calcium was the most abundant element with54.7 wt% and 34.24 atomic percent followed by oxygen with 37.26 wt% and 58.42 atomic percent. It was concluded that the SEM, XRD, and EDX are the most significant techniques to characterize nano-catalysts in particular and other compounds generally.

20.
Environ Sci Pollut Res Int ; 27(32): 39753-39762, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32141003

RESUMO

Availability of lead (Pb) in soil is a major factor controlling the phytoremediation efficiency of plants. This study was focused on investigating the plant-induced changes in rhizosphere and corresponding effect on bioavailable fraction of Pb and accumulation in different plant parts. For rhizosphere study, special cropping device was designed locally. Two Pb accumulator plants Stigmatocarpum criniflorum (L. f.) L. Bolus and Pelargonium × hortorum L.H. Bailey were grown in cropping device setup containing Pb spiked soil (500, 1000, 1500, and 2000 mg kg-1) for a period of 3 weeks. Further plants were also analyzed for Pb-induced oxidative stress. The results indicated higher ability of soil adjustment for Pb uptake by P. hortorum. The soil pH was (p < 0.05) decreased (ΔpH = - 0.22 pH), and dissolved organic carbon (DOC) content was significantly increased (by 1.7-fold) in rhizosphere of P. hortorum. The bioavailable fraction of Pb was twofold higher in rhizosphere of P. hortorum than S. criniflorum at the same soil Pb concentration (2000 mg kg-1). Maximum Pb concentration in root and shoot of S. criniflorum was 755 ± 99 and 207 ± 12 mg Pb/kg DW and for P. hortorum was 1281 ± 77 and 275 ± 7 mg Pb/kg DW. P. hortorum uptakes more Pb per plant by threefold compared with S. criniflorum. The oxidative stress results indicated higher Pb tolerance and suitability of P. hortorum for phytoextraction of Pb-contaminated soil.


Assuntos
Pelargonium , Poluentes do Solo , Biodegradação Ambiental , Chumbo , Raízes de Plantas/química , Rizosfera , Solo , Poluentes do Solo/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...