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1.
Molecules ; 26(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34641304

RESUMO

The current research work illustrates an economical and rapid approach towards the biogenic synthesis of silver nanoparticles using aqueous Punica granatum leaves extract (PGL-AgNPs). The optimization of major parameters involved in the biosynthesis process was done using Box-Behnken Design (BBD). The effects of different independent variables (parameters), namely concentration of AgNO3, temperature and ratio of extract to AgNO3, on response viz. particle size and polydispersity index were analyzed. As a result of experiment designing, 17 reactions were generated, which were further validated experimentally. The statistical and mathematical approaches were employed on these reactions in order to interpret the relationship between the factors and responses. The biosynthesized nanoparticles were initially characterized by UV-vis spectrophotometry followed by physicochemical analysis for determination of particle size, polydispersity index and zeta potential via dynamic light scattering (DLS), SEM and EDX studies. Moreover, the determination of the functional group present in the leaves extract and PGL-AgNPs was done by FTIR. Antibacterial and antibiofilm efficacies of PGL-AgNPs against Gram-positive and Gram-negative bacteria were further determined. The physicochemical studies suggested that PGL-AgNPs were round in shape and of ~37.5 nm in size with uniform distribution. Our studies suggested that PGL-AgNPs exhibit potent antibacterial and antibiofilm properties.

2.
Molecules ; 26(19)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34641393

RESUMO

This study reported the volatile profile, the antimicrobial activity and the synergistic potential of essential oil (EO) from the Moroccan endemic Thymus atlanticus (Ball) Roussine, in combination with the antibiotics ciprofloxacin and fluconazole for the first time, to the best of our knowledge. The EO chemical composition was determined by gas chromatography coupled to mass spectrometry (GC-MS) analysis and the antimicrobial activity assessed by the disc diffusion method against three Gram positive (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli and one clinical isolate, Klebsiella pneumonia). The antifungal activity was evaluated in four pathogenic yeasts (Candida albicans, C. glabrata, C. krusei and C. parapsilosis). The minimum inhibition concentration (MIC) and the synergistic effect with ciprofloxacin and fluconazole were determined by the two-fold dilution technique and checkerboard test, respectively. Twenty-one constituents were identified by GC-MS in the EO, including carvacrol (21.62%) and borneol (21.13%) as the major components. The EO exhibited a significant antimicrobial activity with inhibition zones ranging from 0.7 mm to 22 mm for P. aeruginosa and B. subtilis, respectively, and MIC values varying from 0.56 mg/mL to 4.47 mg/mL. The fractional inhibitory concentration index (FICI) values ranged from 0.25 to 0.50 for bacteria and from 0.25 to 0.28 for yeasts. The maximum synergistic effect was observed for K. pneumonia with a 256-fold gain of antibiotic MIC. Our results have suggested that EO from T. atlanticus may be used alone or in association with antibiotics as a new potential alternative to prevent and control the emergence of resistant microbial strains both in the medical field and in the food industry.

3.
Ecotoxicol Environ Saf ; 226: 112855, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34628153

RESUMO

The present study reports the synthesis, photocatalytic decolorization of reactive black 5 dye and phytotoxicity of graphene quantum dots (GQDs) and iron co-doped TiO2 photocatalysts via modified sol gel method. GQDs were synthesized by direct pyrolysis of citric acid (CA). Scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS), Raman spectroscopy, atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS), Brunauer-Emmett-Teller (BET) and photoluminescence spectroscopy (PL) were used to determine the physicochemical properties of the best performing photocatalysts. The results indicated improved physicochemical properties of GQD-0.1Fe-TiO2-300 with root mean square roughness (Rz) (33.82 nm), higher surface area (170.79 m2 g-1), pore volume (0.08 cm3 g-1), and bandgap (2.94 eV). Moreover, GQD-0.1Fe co-doping of TiO2 greatly improved the photocatalytic decolorization efficiency for RB5 dye. The photocatalytic reaction followed the pseudo first order reaction with gradual decrease in Kapp values for increment in RB5 concentration. The KC value was obtained as 2.45 mg L-1 min-1 while the KLH value was 0.45 L mg-1 indicating the heterogeneous reaction system followed the Langmuir-Hinshelwood isotherm and simultaneously occurring adsorption and photocatalytic processes. Photocatalytic reaction mechanism studies exhibited the holes and OH radicals as the main active species in the GQD-0.1Fe-TiO2-300 responsible for the decolorization of RB5. The proposed reaction pathway showed that both Fe-TiO2 and GQDs play important role in generation of electrons and holes. Additionally, GQD-0.1Fe-TiO2-300 were durable up to four cycles. Phytotoxicity assay displayed that treated water and best performing photocatalysts had no effect on Lycopersicon esculentum seed germination. Therefore, the proposed system can pave a viable solution for safe usage of dye loaded wastewater and effluent for irrigation after treatment.

4.
Int J Med Inform ; 156: 104600, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34638012

RESUMO

INTRODUCTION: Globally mobile ownership and access is becoming very common, and breakthroughs in mobile technology have shaped digital communication, with 7 billion mobile phone users globally. Developing countries account for 80% of newly purchased mobile phone devices with majority of such countries having low Routine Immunization coverage and a high risk of vaccine preventable diseases. The use of mobile phones provides a tremendous potential for public health involvement. OBJECTIVE: The aim of this study is to assess the acceptability and usability of mobile phones among infant caregivers in a LMIC setup and to explore the role of mHealth to improve immunization uptake and coverage. METHODS: This is a cross-sectional survey exploring the regional differences in mobile phone ownership, usability and preferences, along with level of trust with others while sharing a mobile phone. The study was conducted with caregivers of infants in an urban and rural sites of Pakistan. RESULTS: A total of 4472 households were approached, of which 3337 participants were eligible for the study (74.61 %). The reasons for not participating in the study (n = 1135) included (i) household locked or refusal to participate for 594 families (52%), (ii) child older than 14 days of life in 409 cases (36%), (iii) 80 (7%) families did not have access to a functional mobile phone, (iv) 36 (3%)families did not provide a mobile phone number, and (v) 14 (1%) could not stay within the HDSS for 6 months. Access to mobile phone with SMS features was considerably high at both sites: 99.1% in Matiari (rural site) and 96.7% in Karachi (urban). In Matiari 96.6% of the respondents reported having daily access to the phone, contrasting with only 51.4% in Karachi. In Karachi, the predominant spoken language was Urdu, whereas majority of the respondents in Matiari spoke Sindhi (34.6% vs. 70.9%). CONCLUSION: Our study indicates high access to mobile phone in both urban and rural setup, However access to smart phone is still limited, urban and rural setup. Further, the acceptance of overall health- and barrier-based child immunization messages through mobile phone were quite high in both settings. Lastly automated calls were preferred over SMS due to literacy and local settings. This bears important implications for improving child immunization uptake through mobile phones in developing regions such as Pakistan.

5.
Bioresour Technol ; 342: 126006, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34583111

RESUMO

In biomass to biofuels production technology enzyme plays a key role. Nevertheless, the high production cost of cellulase enzyme is one of the critical issues in the economical production of biofuels. Nowadays, implementation of nanomaterials as catalyst is emerging as an innovative approach for the production of sustainable energy. In this context, synthesis of nickel cobaltite nanoparticles (NiCo2O4 NPs) via in vitro route has been conducted using fungus Emericella variecolor NS3 meanwhile; its impact has been evaluated on improved thermal and pH stability of crude cellulase enzyme obtained from Emericella variecolor NS3. Additionally, bioconversion of alkali treated rice straw using NiCo2O4 NPs stabilized cellulase produced sugar hydrolyzate which is further used for H2 production via hybrid fermentation. Total 51.7 g/L sugar hydrolyzate produced 2978 mL/L cumulative H2 production after 336 h along with maximum rate 34.12 mL/L/h in 24 h using Bacillus subtilis PF_1 and Rhodobacter sp. employed for dark and photo-fermentation, respectively.

6.
Sci Rep ; 11(1): 19242, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34584124

RESUMO

Highly selective and sensitive 2,7-naphthyridine based colorimetric and fluorescence "Turn Off" chemosensors (L1-L4) for detection of Ni2+ in aqueous media are reported. The receptors (L1-L4) showed a distinct color change from yellow to red by addition of Ni2+ with spectral changes in bands at 535-550 nm. The changes are reversible and pH independent. The detection limits for Ni2+ by (L1-L4) are in the range of 0.2-0.5 µM by UV-Visible data and 0.040-0.47 µM by fluorescence data, which is lower than the permissible value of Ni2+ (1.2 µM) in drinking water defined by EPA. The binding stoichiometries of L1-L4 for Ni2+ were found to be 2:1 through Job's plot and ESI-MS analysis. Moreover the receptors can be used to quantify Ni2+ in real water samples. Formation of test strips by the dip-stick method increases the practical applicability of the Ni2+ test for "in-the-field" measurements. DFT calculations and AIM analyses supported the experimentally determined 2:1 stoichiometries of complexation. TD-DFT calculations were performed which showed slightly decreased FMO energy gaps due to ligand-metal charge transfer (LMCT).

7.
Bioresour Technol ; : 126034, 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34592453

RESUMO

The present study reports Fe3O4 nanoparticles (Fe3O4 NPs) induced enhanced hydrogen production via co-fermentation of glucose and residual algal biomass (cyanobacteria Lyngbya limnetica). A significant enhancement of dark fermentative H2 production has been noticed under the influence of co-fermentation of glucose and residual algal biomass using Fe3O4 NPs as catalyst. Further, using the optimized ratio of glucose to residual algal biomass (10:4), ∼ 37.14 % higher cumulative H2 has been recorded in presence of 7.5 mg/L Fe3O4 NPs as compared to control at 37°C. In addition, under the optimum conditions [glucose to residual algal biomass ratio (10:4)] presence of 7.5 mg/L Fe3O4 NPs produces ∼937 mL/L cumulative H2 in 168 h at pH 7.5 and at temperature 40°C. Clostridum butyrium, employed for the dark fermentation yielded ∼7.7 g/L dry biomass in 168 h whereas acetate (9.0 g/L) and butyrate (6.2 g/L) have been recorded as the dominating metabolites.

8.
Bioresour Technol ; 342: 126015, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34592619

RESUMO

High production cost of cellulase enzyme is one of the main constraints in the practical implementation of biofuels at global scale. Therefore, the present investigation is focused to produce low-cost cellulase via sustainable strategies. This work evaluates to achieve enhanced fungal cellulase production using natural and pretreated sugar cane bagasse (SCB) via Rhizopus oryzae NS5 under the solid state fermentation (SSF) while implementing graphene oxide (GO) as a catalyst. A low alkali treatment showed better performance for cellulase production wherein 14 IU/gds FP activity is observed in 96 h using 0.5% alkali treated SCB, significantly higher as compared to 10 IU/gds FP in case of untreated SCB. Further, the effect of GO has been investigated on cellulase production, incubation temperature and pH of the production medium. Under the influence of 1.5% concentration of GO, alkali pretreated SCB produced maximum 25 IU/gds cellulase in 72 h at pH 5.0 and 40 °C.

9.
Spectrochim Acta A Mol Biomol Spectrosc ; 265: 120356, 2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34536896

RESUMO

A selective and sensitive detection of L-cysteine (Cys) is an important tool for various biological studies. Here, Au nanoparticles (NPs) were prepared by chemical reduction technique. The probe was developed to detect and quantify Cys in the presence of Cr3+ ions which acts as a cross linker. The citrate capped Au NPs probe was analyzed by UV-visible spectrophotometry, TEM, EDAX, FTIR, DLS, XPS and zetasize. The zeta potential and effective size of Au NPs were -41.22 mV and 12 nm, respectively. The Cys interaction with Au NPs showed drastic colour variation from red to purple and colourless with rapid response time of 1 min. The limit of detection (LOD) of Au NPs probe was as low as 0.012 nM. The TEM image of Au NPs after Cys interaction verified the aggregation that resulted in colour change. The XPS core level scans of Au 4f showed 0.3 eV red shift when Cyswas interacted. The Au NPs sensor is highly selective for Cys with excellent reproducibility. Acidic pH slightly favored Cys detection. Further, the probe was applied to estimate Cys quantity from milk, urine, blood and environmental augmented samples in the presence of other amino acids . The study suggests that the proposed Au NPs could detect Cys with high accuracy from various biological samples.

10.
Bioresour Technol ; 341: 125891, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34523576

RESUMO

In the present study, pyrolysis of mangifera indica L., Artocarpus heterophyllus L. and jambolana seeds have been performed using thermogravimetric analysis. These biomasses have enriched lignocellulosic composition of hemicellulose (5-10%) and lignin (1-3%) which are unexplored. The TGA analysis was performed at various heating rates of 10, 15, 20, 25 and 30 °C/min from 25 to 600 °C. Kinetic investigation of the pyrolysis method using TGA statistics has been done using iso-conversional models of Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Vyazovkin and Vyazovkin AIC. The apparent activation energies value ranged from 179.86 to 226.31 kJ/mol in the fractional conversion range of 0.1 to 0.7.


Assuntos
Artocarpus , Lignina/análise , Mangifera , Sementes/química , Syzygium , Biomassa , Cinética , Termogravimetria
11.
Ecotoxicol Environ Saf ; 226: 112826, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34592521

RESUMO

Levofloxacin antibiotic is frequently being detected in the environment and regarded as an emerging contaminant. The present study was focused on the green synthesis of magnetite (Fe3O4 - gINPs) nanoparticles from Moringa olifera and its efficiency for removal of levofloxacin from aqueous solution. The adsorbent magnetite nanoparticles (Fe3O4) were prepared by green synthesis using Moringa olifera and coprecipitation method. Characterizations analyses of both chemically and green synthesized nanoparticles were performed by SEM, XRD, and FTIR. The average crystallite size of gINPs was 14.34 nm and chemically synthesized was 18.93 nm. The performance of the synthesized product was evaluated by adsorption capacity and removal efficiency. The parameters considered included adsorbent (gINPs) dosage, initial concentration of adsorbate, pH, contact time, and temperature. The obtained data were fitted to kinetic and isotherm models to determine the mechanism. Adsorption batch experiments were conducted to determine the reaction mechanism by studying kinetics while fitting isotherm models for samples analyzed using HPLC at 280 nm. Results showed that 86.15% removal efficiency of 4 mg L-1 levofloxacin was achieved by 100 mg L-1 gINPs in 24 h contact time when all other parameters (pH 7, temperature 25 °C) were kept constant. The maximum adsorption capacity achieved at equilibrium was 22.47 mg/g. Further, it was identified as a pseudo-second-order model with R2 = 0.965 for adsorption kinetics while isotherm data better fitted to the Freundlich model compared to Langmuir isotherm with R2 = 0.994. The potential pathway determined for levofloxacin removal was chemisorption with minor diffusion, multilayer, spontaneous and exothermic processes on the gINPs (Fe3O4). Reusability experiments were conducted in four cycles and removal efficiency varied from 85.35% to 80.47%, indicating very high potential of the adsorbent for re-use.

12.
Front Immunol ; 12: 706081, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34386011

RESUMO

Dissecting the function(s) of proteins present exclusively in Mycobacterium tuberculosis (M.tb) will provide important clues regarding the role of these proteins in mycobacterial pathogenesis. Using extensive computational approaches, we shortlisted ORFs/proteins unique to M.tb among 13 different species of mycobacteria and identified a hypothetical protein Rv1509 as a 'signature protein' of M.tb. This unique protein was found to be present only in M.tb and absent in all other mycobacterial species, including BCG. In silico analysis identified numerous putative T cell and B cell epitopes in Rv1509. Initial in vitro experiments using innate immune cells demonstrated Rv1509 to be immunogenic with potential to modulate innate immune responses. Macrophages treated with Rv1509 exhibited higher activation status along with substantial release of pro-inflammatory cytokines. Besides, Rv1509 protein boosts dendritic cell maturation by increasing the expression of activation markers such as CD80, HLA-DR and decreasing DC-SIGN expression and this interaction was mediated by innate immune receptor TLR2. Further, in vivo experiments in mice demonstrated that Rv1509 protein promotes the expansion of multifunctional CD4+ and CD8+T cells and induces effector memory response along with evoking a canonical Th1 type of immune response. Rv1509 also induces substantial B cell response as revealed by increased IgG reactivity in sera of immunized animals. This allowed us to demonstrate the diagnostic efficacy of this protein in sera of human TB patients compared to the healthy controls. Taken together, our results reveal that Rv1509 signature protein has immunomodulatory functions evoking immunological memory response with possible implications in serodiagnosis and TB vaccine development.

13.
Spectrochim Acta A Mol Biomol Spectrosc ; 263: 120204, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34333401

RESUMO

Recent trends in nanotechnology paved a way for the development of detection systems for heavy metals, toxins and environmental pollutants. The present study focused on Hg2+ detection by a core shell Fe@Ag-starch nanosphere phenylalanine conjugate. The characterization of core shell Fe@Ag-starch nanosphere was performed by using TEM, zetasizer, particlesize analyzer, UV-visible absorption spectrophotometer, EDAX, FTIR and TGA. The NPs showed λmax at 408 nm. The effective diameter of synthesized nanosphere was 37 ± 2 nm and it possessed the surfaces charge of -36.12 ± 2.5 mV. The Fe@Ag-starch-phenylalanine conjugate reacted with Hg2+, the yellow colour of the nanosphere phenylalanine conjugate became colourless. The real water sample was collected and the amount of Hg2+ was calculated by using the prepared nanosphere. The detection of Hg2+ at different conditions including various saline concentrations, temperature and pH were also studied and the detection was found to be effective at 40 °C, pH 5 and 0.1% of saline concentration. The LOD of Hg2+ ions by Fe@Ag-starch nanosphere were calculated to be 1.84 nM. The influence of other metal ions present in the analyte did not show any interference on Hg2+ detection. In addition, the photocatalytic and antibacterial activities of Fe@Ag-starch nanosphere were also studied. The study confirmed that the core shell nanosphere can also be used for environmental cleanup and disinfection.


Assuntos
Mercúrio , Nanopartículas Metálicas , Nanosferas , Concentração de Íons de Hidrogênio , Íons , Prata , Amido , Ressonância de Plasmônio de Superfície , Água
14.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361745

RESUMO

The edible parts of the plants Camellia sinensis, Vitis vinifera and Withania somnifera were extensively used in ancient practices such as Ayurveda, owing to their potent biomedical significance. They are very rich in secondary metabolites such as polyphenols, which are very good antioxidants and exhibit anti-carcinogenic properties. This study aims to evaluate the anti-cancerous properties of these plant crude extracts on human liver cancer HepG2 cells. The leaves of Camellia sinensis, Withania somnifera and the seeds of Vitis vinifera were collected and methanolic extracts were prepared. Then, these extracts were subjected to DPPH, α- amylase assays to determine the antioxidant properties. A MTT assay was performed to investigate the viability of the extracts of HepG2 cells, and the mode of cell death was detected by Ao/EtBr staining and flow cytometry with PI Annexin- V FITC dual staining. Then, the protein expression of BAX and BCl2 was studied using fluorescent dye to determine the regulation of the BAX and BCl2 genes. We observed that all the three extracts showed the presence of bioactive compounds such as polyphenols or phytochemicals. The W. somnifera bioactive compounds were found to have the highest anti-proliferative activity on human liver cancer cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Camellia sinensis/química , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Vitis/química , Withania/química , Alcaloides/química , Alcaloides/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Compostos de Bifenilo/antagonistas & inibidores , Compostos de Bifenilo/química , Morte Celular/efeitos dos fármacos , Flavonoides/química , Flavonoides/isolamento & purificação , Células Hep G2 , Humanos , Picratos/antagonistas & inibidores , Picratos/química , Extratos Vegetais/química , Folhas de Planta/química , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sementes/química , Transdução de Sinais , Taninos/química , Taninos/isolamento & purificação , Terpenos/química , Terpenos/isolamento & purificação , alfa-Amilases/genética , alfa-Amilases/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
15.
Artigo em Inglês | MEDLINE | ID: mdl-34382171

RESUMO

Microbially induced carbonate precipitation (MICP) is an advanced bioremediation approach to remediate heavy metal (HM)-contaminated water and soil. In this study, metal-tolerant urease-producing bacterial isolates, namely, UR1, UR16, UR20, and UR21, were selected based on their urease activity. The efficiency of these isolates in water for Pb and Cd immobilizations was explored. Our results revealed that UR21 had the highest removal rates of Pb (81.9%) and Cd (65.0%) in solution within 72 h through MICP. The scanning electron microscopy-energy-dispersive x-ray and x-ray diffraction analysis confirmed the structure and the existence of PbCO3 and CdCO3 crystals in the precipitates. In addition, the strain UR21, in combination with urea/eggshell waste (EGS) or both, was further employed to investigate the effect of MICP on soil enzymatic activity, chemical fractions, and bioavailability of Pb and Cd. The outcomes indicated that the applied treatments reduced the proportion of soluble-exchangeable-Pb and -Cd, which resulted in an increment in carbonate-bound Pb and Cd in the soil. The DTPA-extractable Pb and Cd were reduced by 29.2% and 25.2% with the treatment of UR21+urea+EGS as compared to the control. Besides, the application of UR21 and EGS significantly increased the soil pH, cation exchange capacity, and enzyme activities. Our findings may provide a novel perceptive for an eco-friendly and sustainable approach to remediate heavy metal-contaminated environment through a combination of metal-resistant ureolytic bacterial strain and EGS.

16.
Appl Nanosci ; : 1-11, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34367863

RESUMO

The present study was investigated to synthesis the iron nanoparticles (FeNPs) using the leaf extract of Phyllanthus reticulatus. The phytosynthesized FeNPs exhibited UV-visible absorption peaks at 229 nm and its crystalline nature was confirmed through XRD. FT-IR analysis revealed the presence of various functional groups which are responsible for the bioreduction of FeNPs. The SEM results showed that FeNPs were aggregated, irregular sphere shaped with rough surfaces and EDX spectrum recorded densely occupied iron nanoparticles region. The particle size range of the synthesized iron nanoparticles was 185.6 nm. The FeNPs showed potential methylene blue decolourisation activity which was visually observed by gradual colour change in the dye solution from deep blue to colorless. The control exhibited no change in coloration during exposure to sunlight and the iron nanoparticles completely disintegrated the methylene blue within 10 s in 10 mg/L methylene blue (98%), whereas the color change was decreased when the concentration of the dye increased. In addition, the phyto-synthesized FeNPs exhibited extensive antibacterial and antifungal activity against the selected pathogens. Phytotoxicity assay confirms the potential of biosynthesized iron nanoparticles as a fertilizer for the growth of green gram seeds. Thus the present study leads to development of cost-effective green synthesis, reduction of toxic chemicals and its extensive applications in the biological sciences.

17.
Environ Pollut ; 289: 117854, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34333267

RESUMO

Expanding applications of metal-oxide nanoparticles (NPs) and increased environmental deposition of NPs followed by their interactions with edible crops threaten yields. This study demonstrates the effects of aging (45 days in soil) of four NPs (ZnO, CuO, Al2O3, TiO2; 3.9-34 nm) and their corresponding metal oxide bulk particles (BPs; 144-586 nm) on cucumbers (Cucumis sativus L.) cultivated in sandy-clay-loam field soil and compares these with the phytotoxic effects of readily soluble metal salts (Zn2+, Cu2+, and Al3+). Data revealed the cell-to-cell translocations of NPs, their attachments to outer and inner cell surfaces, nuclear membranes, and vacuoles, and their upward movements to aerial parts. Metal bioaccumulations in cucumbers were found in the order: (i) ZnO-NPs > ZnO-BPs > Zn2+, (ii) CuO-NPs > CuO-BPs > Cu2+, (iii) Al3+> Al2O3-NPs > Al2O3-BPs and (iv) TiO2-NPs > TiO2-BPs. Aging of NPs in soil for 45 days significantly enhanced metal uptake (P ≤ 0.05), for instance aged ZnO-NPs at 1 g kg-1 increased the uptake by 20.7 % over non-aged ZnO-NPs. Metal uptakes inhibited root (RDW) and shoot (SDW) dry weight accumulations. For Cu species, maximum negative impact (%) was exhibited by Cu2+ (RDW:SDW = 94:65) followed by CuO-NPs (RDW:SDW = 78:34) and CuO-BPs (RDW:SDW = 27:22). Aging of NPs/BPs at 1-4 g kg-1 further enhanced the toxic impact of tested materials on biomass accumulations and chlorophyll formation. NPs also induced membrane damage of root tissues and enhanced levels of antioxidant enzymes. The results of this study suggest that care is required when aged metal-oxide NPs of both essential (Zn and Cu) and non-essential (Al and Ti) metals interact with cucumber plants, especially, when they are used for agricultural purposes.


Assuntos
Cucumis sativus , Nanopartículas Metálicas , Nanopartículas , Óxido de Zinco , Bioacumulação , Argila , Cobre/análise , Cobre/toxicidade , Íons , Nanopartículas Metálicas/toxicidade , Óxidos , Areia , Solo , Óxido de Zinco/toxicidade
18.
Environ Pollut ; 289: 117861, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34343751

RESUMO

The hydrothermal preparation of o-dianisidine and triazine interlinked porous organic polymer and its successive derivatisation via metal infusion (Ni, Cu) under hydrothermal and calcination conditions (700 °C) to yield pristine (ANIPOP-700) and Ni/Cu decorated porous carbon are described here (Ni-ANIPOP-700 and Cu-ANIPOP-700). To confirm their chemical and morphological properties, the as-prepared materials were methodically analyzed using solid state 13C and 15N NMR, X-ray diffraction, Raman spectroscopy, field emission scanning and high resolution transmission electron microscopic techniques, and x-ray photoelectron spectroscopy. Furthermore, the electrocatalytic activities of these electrocatalysts were thoroughly investigated under standard oxygen evolution (OER) and hydrogen evolution reaction (HER) conditions. The results show that all of the materials demonstrated significant activity in water splitting as well as displayed excellent stability (22 h) in both acidic (HER) and basic conditions (OER). Among the electrocatalysts reported in this study, Ni-ANIPOP-700 exhibited a lower overpotential η10 of 300 mV in basic medium (OER) and 150 mV in acidic medium (HER), as well as a lower Tafel slope of 69 mV/dec (OER) and 181 mV/dec (HER), indicating 30% lower energy requirement for overall water splitting. Gas chromatography was used to examine the electrolyzed products.


Assuntos
Carbono , Polímeros , Eletrólise , Porosidade , Água do Mar
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120253, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34391992

RESUMO

Globally, the environmental pollution is one of the major issues causing toxicity towards human and aquatic life. We have developed a facile and innovative sensing approach for detection of sulphide ions (S2-) present in the aqueous media using Ag0 decorated Cr2S3 NPs embedded on PVP matrix (Ag/Cr2S3-PVP). Based on the SPR phenomena, the detection of S2- ions was established. The nanohybrid was characterized using various techniques such as UV-vis spectrophotometer, High-Resolution Transmission Electron Microscopy (HR-TEM), Thermal Gravimetric Analysis (TGA), X-ray diffraction analysis(XRD), Energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The yellowish colour of Ag/Cr2S3-PVP nanohybrid turned to brown colour in presence of S2- ions. The selectivity and sensitivity of the prepared probe was studied against the other interfering metal ions. In addition, the effect of different concentration of S2- ions in the nanohybrid solution was investigated and the Limit of detection (LOD) was found to be 6.6 nM. The good linearity was found over the range of 10 nM to 100 µM with R2 value of 0.981. The paper strip based probe was developed for rapid onsite monitoring of S2- ions. The proposed method is found to be cost-effective, rapid, and simple. We have validated the practical applicability of the prepared probe for determining the concentration of S2- ions in real water samples.

20.
PLoS Negl Trop Dis ; 15(7): e0009584, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34264936

RESUMO

Environmental enteric dysfunction (EED) is a subclinical condition of intestinal inflammation, barrier dysfunction and malabsorption associated with growth faltering in children living in poverty. This study explores association of altered duodenal permeability (lactulose, rhamnose and their ratio) with higher burden of enteropathogen in the duodenal aspirate, altered histopathological findings and higher morbidity (diarrhea) that is collectively associated with linear growth faltering in children living in EED endemic setting. In a longitudinal birth cohort, 51 controls (WHZ > 0, HAZ > -1.0) and 63 cases (WHZ< -2.0, refractory to nutritional intervention) were recruited. Anthropometry and morbidity were recorded on monthly bases up to 24 months of age. Dual sugar assay of urine collected after oral administration of lactulose and rhamnose was assessed in 96 children from both the groups. Duodenal histopathology (n = 63) and enteropathogen analysis of aspirate via Taqman array card (n = 60) was assessed in only cases. Giardia was the most frequent pathogen and was associated with raised L:R ratio (p = 0.068). Gastric microscopy was more sensitive than duodenal aspirate in H. pylori detection. Microscopically confirmed H. pylori negatively correlated with HAZ at 24 months (r = -0.313, p = 0.013). Regarding histopathological parameters, goblet cell reduction significantly correlated with decline in dual sugar excretion (p< 0.05). Between cases and controls, there were no significant differences in the median (25th, 75th percentile) of urinary concentrations (µg/ml) of lactulose [27.0 (11.50, 59.50) for cases vs. 38.0 (12.0, 61.0) for controls], rhamnose [66.0 (28.0, 178.0) vs. 86.5 (29.5, 190.5)] and L:R ratio [0.47 (0.24, 0.90) vs. 0.51 (0.31, 0.71)] respectively. In multivariable regression model, 31% of variability in HAZ at 24 months of age among cases and controls was explained by final model including dual sugars. In conclusion, enteropathogen burden is associated with altered histopathological features and intestinal permeability. In cases and controls living in settings of endemic enteropathy, intestinal permeability test may predict linear growth. However, for adoption as a screening tool for EED, further validation is required due to its complex intestinal pathophysiology.

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