19 research outputs found

    Quantification of Amu River Riverbank Erosion in Balkh Province of Afghanistan during 2004–2020

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    In this study, we propose quantifying the Amu River riverbank erosion with the modelled river discharge in Kaldar District, Balkh Province of Afghanistan from 2004 to 2020. We propose a framework synergizing multi-source information for modelling the erosion area based on three components: (1) river discharge, (2) river width, and (3) erosion area. The total river discharge for the watershed shared by Afghanistan and Tajikistan was modelled using hydrological parameters from the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) data through multivariate linear regression with ground station data. The river width was determined manually using the Normalized Difference Water Index (NDWI) derived from Landsat data. The riverbank erosion area was derived from the digital shoreline analysis using the NDWI. The digital shoreline analysis showed that, between 2008 and 2020, the average riverbank erosion area in Kaldar District is about 5.4 km2 per year, and, overall, 86.3 km2 during 2004–2020 due to flood events. The significantly higher land loss events occurred at 10 km2 bank erosion during the years 2008–2009 and 2015–2016, and 19 km2 peak erosion occurred during 2011–2012. A linear relation between the erosion area with respect to the discharge intensity and the specific stream power was observed with an R2 of 0.84 and RMSE of 1.761 for both

    Chemical Composition, FTIR Studies and Antibacterial Activity of Passiflora edulis f. edulis (Fruit)

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    Because of the strong interest in the use of bio-products as alternatives to chemically derived antibiotics or antimicrobial agents, passion fruits extracts were evaluated for their antibacterial activity and chemical composition. Various solvent extracts of P. edulis were screened for their antibacterial activity by Agar well diffusion technique against an array of pathogenic bacteria (Gram positive and negative). Macro dilution technique was used to determine the Minimum inhibitory concentration of the potent extracts. Bacterial strain showing significant inhibition was further subjected to scanning electron microcopy (SEM) and the morphological changes induced by extracts were noted. Chemical composition of extracts showing strong antibacterial activity was determined by GC-MS and FTIR analysis. Extracts of Passion fruit (pulp with seeds) show significant inhibitory effects against test isolates but in a variable manner. Amongst all the test isolates Bacillus subtilis showed maximum inhibition followed by E. coli and P. aeruginosa. Ethyl acetate extracts had the least activity against the tested microorganisms. Gas chromatography-mass spectrometry of ethanol extracts showed the presence of important chemicals, such as Tetracosamethyl-cyclododecasiloxane; Dodecanoic acid, 10-methyl-, methyl ester cyclosiloxane, hexadecamethyl; 3-isopropoxy-1,1,1,7,7,7-hexamethyl-3,5,5-tris (trimethylsiloxy)tetrasil; 9-hexadecenoic acid, 9-octadecenyl ester, (Z,Z)- Fourier transform infrared studies revealed important functional groups which included phenols, esters, flavonoids, aromatic compounds, and alcohols. Significant antibacterial activity of the extracts could be attributed to phenolic compounds, esters and other chemical components identified in ethanolic extracts. Scanning electron micrographs of B. subtilis treated with ethanol extracts showed distorted shapes, rough and corrugated cell margins, and aggregations of cells. Our data depict the significant antimicrobial activity of extracts against Gram positive bacteria while the Gram negative bacteria exhibited weak inhibition by all the extracts. Based on our findings, passion fruits can be used in preparations of antimicrobial formulations against Gram positive microorganisms especially B. subtilis

    Antifungal, Antibacterial, and Cytotoxic Activities of Silver Nanoparticles Synthesized from Aqueous Extracts of Mace-Arils of Myristica fragrans

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    In the present study, mace-mediated silver nanoparticles (mace-AgNPs) were synthesized, characterized, and evaluated against an array of pathogenic microorganisms. Mace, the arils of Myristica fragrans, are a rich source of several bioactive compounds, including polyphenols and aromatic compounds. During nano synthesis, the bioactive compounds in mace aqueous extracts serve as excellent bio reductants, stabilizers, and capping agents. The UV-VIS spectroscopy of the synthesized NPs showed an intense and broad SPR absorption peak at 456 nm. Dynamic light scattering (DLS) analysis showed the size with a Z average of 50 nm, while transmission electron microscopy (TEM) studies depicted the round shape and small size of the NPs, which ranged between 5–28 nm. The peaks related to important functional groups, such as phenols, alcohols, carbonyl groups, amides, alkanes and alkenes, were obtained on a Fourier-transform infrared spectroscopy (FTIR) spectrum. The peak at 3 keV on the energy dispersive X-ray spectrum (EDX) validated the presence of silver (Ag). Mace-silver nanoparticles exhibited potent antifungal and antibacterial activity against several pathogenic microorganisms. Additionally, the synthesized mace-AgNPs displayed an excellent cytotoxic effect against the human cervical cancer cell line. The mace-AgNPs demonstrated robust antibacterial, antifungal, and cytotoxic activity, indicating that the mace-AgNPs might be used in the agrochemical industry, pharmaceutical industry, and biomedical applications. However, future studies to understand its mode of action are needed

    Evaluation of Chemical Composition, Antibacterial, Antifungal, and Cytotoxic Activity of Laurus nobilis L Grown in Saudi Arabia

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    Present study aimed to evaluate the chemical composition, antibacterial, antifungal, and cytotoxic activity of Laurus nobilis grown in Tabuk region of Saudi Arabia. Dried leaves of L. nobilis were extracted with various solvent with increasing polarities. Solvent extracts exhibited variable inhibition zones against bacterial pathogens, however all the solvent extracts showed significant inhibition against fungal pathogens. Acetone extracts had the largest inhibition zone against Streptococcus pnemoniae (37.16 ± 0.23 mm) while ethanol and methanol extract showed the most efficient percentage inhibition against mycelial growth of Alternaria alternata (91.33 ± 0.47; 90.66 ± 0.94).High cytotoxicity was demonstrated by methanol and aqueous extracts (IC50 14.90µg/ml, 24.56 µg/ml), while acetone extracts showed moderate effects on cell inhibition (IC50 41.43µg/ml).The significant activity shown by the bay leaf extracts could be attributed to monoterpene hydrocarbons, oxygenated monoterpenes, phenylpropanoids, phenols, and other important phytoconstituents identified in GC- MS and FTIR studies. Our findings clearly show significant antifungal, antibacterial and cytotoxic activity of solvent extracts of bay leaves, which could be attributed to the presence of wide range of phytochemicals. Since plants derived natural products are less toxic, cheaper, and have negligible side effects, they would serve as an excellent alternative to antimicrobial and chemotherapeutic drugs

    Influence of intraspecific competition stress on soil fungal diversity and composition in relation to tree growth and soil fertility in Sub-Tropical soils under Chinese fir monoculture

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    Soil microorganisms provide valuable ecosystem services, such as nutrient cycling, soil remediation, and biotic and abiotic stress resistance. There is increasing interest in exploring total belowground biodiversity across ecological scales to understand better how different ecological aspects, such as stand density, soil properties, soil depth, and plant growth parameters, influence belowground communities. In various environments, microbial components of belowground communities, such as soil fungi, respond differently to soil features; however, little is known about their response to standing density and vertical soil profiles in a Chinese fir monoculture plantation. This research examined the assemblage of soil fungal communities in different density stands (high, intermediate, and low) and soil depth profiles (0–20 cm and 20–40 cm). This research also looked into the relationship between soil fungi and tree canopy characteristics (mean tilt angle of the leaf (MTA), leaf area index (LAI), and canopy openness index (DIFN)), and general growth parameters, such as diameter, height, and biomass. The results showed that low-density stand soil had higher fungal alpha diversity than intermediate- and high-density stand soils. Ascomycota, Basidiomycota, Mucromycota, and Mortierellomycota were the most common phyla of the soil fungal communities, in that order. Saitozyma, Penicillium, Umbelopsis, and Talaromyces were the most abundant fungal genera. Stand density composition was the dominant factor in changing fungal community structure compared to soil properties and soil depth profiles. The most significant soil elements in soil fungal community alterations were macronutrients. In addition, the canopy openness index and fungal community structure have a positive association in the low-density stand. Soil biota is a nutrient cycling driver that can promote better plant growth in forest ecosystems by supporting nutrient cycling. Hence, this research will be critical in understanding soil fungal dynamics, improving stand growth and productivity, and improving soil quality in intensively managed Chinese fir plantations.Fujian Forestry Bureau | Ref. 2020TG19Fujian Provincial Colleges and University Engineering Research Center of Plantation Sustainable management | Ref. PTJH18009King Saud University, Riyadh | Ref. RSP-2021/9

    Thymidine phosphorylase and prostrate cancer cell proliferation inhibitory activities of synthetic 4-hydroxybenzohydrazides: In vitro, kinetic, and in silico studies.

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    Over-expression of thymidine phosphorylase (TP) plays a key role in many pathological complications, including angiogenesis which leads to cancer cells proliferation. Thus in search of new anticancer agents, a series of 4-hydroxybenzohydrazides (1-29) was synthesized, and evaluated for in vitro thymidine phosphorylase inhibitory activity. Twenty compounds 1-3, 6-14, 16, 19, 22-24, and 27-29 showed potent to weak TP inhibitory activities with IC50 values in the range of 6.8 to 229.5 μM, in comparison to the standards i.e. tipiracil (IC50 = 0.014 ± 0.002 μM) and 7-deazaxanthine (IC50 = 41.0 ± 1.63 μM). Kinetic studies on selected inhibitors 3, 9, 14, 22, 27, and 29 revealed uncompetitive and non-competitive modes of inhibition. Molecular docking studies of these inhibitors indicated that they were able to interact with the amino acid residues present in allosteric site of TP, including Asp391, Arg388, and Leu389. Antiproliferative (cytotoxic) activities of active compounds were also evaluated against mouse fibroblast (3T3) and prostate cancer (PC3) cell lines. Compounds 1, 2, 19, and 22-24 exhibited anti-proliferative activities against PC3 cells with IC50 values between 6.5 to 10.5 μM, while they were largely non-cytotoxic to 3T3 (mouse fibroblast) cells proliferation. Present study thus identifies a new class of dual inhibitors of TP and cancer cell proliferation, which deserves to be further investigated for anti-cancer drug development
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