We investigated oxidative stress in human postmortem frontal cortexfrom individuals characterized as mild cognitive impairment (n= 8), mild/moderate Alzheimer disease (n = 4), and late-stage ...Alzheimer disease (n = 9). Samples from subjects with no cognitive impairment (n = 10) that were age- and postmortem interval-matched with these cases were used as controls. The short postmortem intervalbrain samples were processed for postmitochondrial supernatant, nonsynaptic mitochondria, and synaptosome fractions. Samples were analyzed for several antioxidants (glutathione, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, glucose-6-phosphate dehydrogenase, superoxide dismutase, catalase) and the oxidative marker, thiobarbituric acid reactive substances. The tissue was also analyzed for possible changes in protein damage using neurochemical markers for protein carbonyls, 3-nitrotyrosine, 4-hydroxynonenal, andacrolein. All 3 neuropil fractions (postmitochondrial supernatant, mitochondrial, and synaptosomal) demonstrated significant disease-dependent increases in oxidative markers. The highest changes were observed in the synaptosomal fraction. Both mitochondrial and synaptosomal fractions had significant declines in antioxidants (glutathione, glutathione peroxidase, glutathione-S-transferase, and superoxide dismutase). Levels of oxidative markers significantly correlated with Mini-Mental Status Examination scores. Oxidative stress was more localized to the synapses, with levels increasing in a disease-dependent fashion. These correlations implicate an involvement of oxidative stress in Alzheimer disease-related synaptic loss.
Climate change is an inherent and indispensable component of global development and deliberations on food security and sustainable farm livelihoods. This article attempts to highlight the key issues ...with regards to climate change, and propounds an approach to upscale holistic and appropriate Climate Smart Agriculture (CSA). The review addresses the climate change impact on, and intricacies of, farm livelihoods, vulnerability and adaptation strategies. Preordained holistic strategies such as CSA can curtail widespread detrimental effects of climate change on farm households, farm productivity and farm profitability through adaptation strategies. Consequently, the agricultural sector of developing countries like India is being restructured, reformed and realigned to contextualize the climate change-sustainable agriculture-farm livelihood nexus. Our exhaustive literature review exhorts a framework of how various types of CSA interventions (scientific technologies, indigenous technical knowledge, institutional innovations and information and communication technologies) can help to promote sustainable livelihood outcomes. The implementation of this approach is driven by the livelihood status of various strata of farmers, along with their vulnerability profile, resilience capacity and climate knowledge with regards to contrasting rationales of climatic vagaries. Climate change is a global process with local visibility; in countries that are dependent on an agrarian economy, a balanced mix of adaptation mechanisms to de-risk the vulnerable farm livelihoods and re-route them towards smart interventions can be important for climate-proofing agriculture. The above mentioned framework provides a robust future course of action for circumventing adverse climatic impacts.
Introduction: An electrochemical sensor has the ability to transform the associated data containing electrochemical reactions into a reliable representative signal. The electrochemical sensors can be ...classified into potentiometric, conductometric, and ampere-metric or Volta-metric. Although, there are various electrochemical techniques for the detection of Vitamin D3, there is still a need for a simplified and cost-effective method. An electrochemical sensor provides great sensitivity towards the detection of the analyte. Aim: To fabricate an electrochemical sensor for the detection of Vitamin D3. The sensor used Molecular Imprinted Polymer (MIP) based Screen Printed Carbon Electrode (SPCE). Materials and Methods: The SPCE used was a three-electrode system consisting of silver working electrode, silver reference electrode and a counter carbon electrode. The reagents used in the experiment was p-Phenylenediamine, resorcinol and Vitamin D3 that were applied in a particular amount onto the SPCE. The process of electropolymerisation was carried out in order to form a non-conductive layer. Cavities were gradually formed on the surface of SPCE. A mediator was used to obtain reliable results for the detection of Vitamin D3. It is evident from the existing literature that the number of scans of electropolymerisation holds a significant role in this process. The procedure was applied for the formation of non-imprinted electrode in the absence of the analyte. Results: The presence of the template i.e., Vitamin D3 was recorded using the developed electrochemical sensor. The current decreased on rebinding of Vitamin D3 which resulted in the change of redox peak of ferricyanide. This signified the sudden increase in concentration of Vitamin D3 specifying its presence. Conclusion: The results obtained specifies the great sensitivity of the electrochemical sensor towards the template i.e., vitamin D3. The clinical relevance of such electrochemical sensors is that they produce simple, accurate and reproducible results which can be used to optimise the care of patients.
The pathogenicity in Candida spp was attributed by several virulence factors such as production of tissue damaging extracellular enzymes, germ tube formation, hyphal morphogenesis and establishment ...of drug resistant biofilm. The objective of present study was to investigate the effects of silver nanoparticles (AgNPs) on growth, cell morphology and key virulence attributes of Candida species.
AgNPs were synthesized by the using seed extract of
(Sc), and were characterized by UV-Vis spectrophotometer, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM). ScAgNPs were used to evaluate their antifungal and antibacterial activity as well as their potent inhibitory effects on germ tube and biofilm formation and extracellular enzymes viz. phospholipases, proteinases, lipases and hemolysin secreted by
spp.
The MICs values of ScAgNPs were ranged from 0.125-0.250 mg/ml, whereas the MBCs and MFCs were 0.250 and 0.500 mg/ml, respectively. ScAgNPs significantly inhibit the production of phospholipases by 82.2, 75.7, 78.7, 62.5, and 65.8%; proteinases by 82.0, 72.0, 77.5, 67.0, and 83.7%; lipase by 69.4, 58.8, 60.0, 42.9, and 65.0%; and hemolysin by 62.8, 69.7, 67.2, 73.1, and 70.2% in
,
,
,
and
, respectively, at 500 μg/ml. ScAgNPs inhibit germ tube formation in C. albicans up to 97.1% at 0.25 mg/ml. LIVE/DEAD staining results showed that ScAgNPs almost completely inhibit biofilm formation in C. albicans. TEM analysis shows that ScAgNPs not only anchored onto the cell surface but also penetrated and accumulated in the cytoplasm that causes severe damage to the cell wall and cytoplasmic membrane.
To summarize, the biosynthesized ScAgNPs strongly suppressed the multiplication, germ tube and biofilm formation and most importantly secretion of hydrolytic enzymes (viz. phospholipases, proteinases, lipases and hemolysin) by Candia spp. The present research work open several avenues of further study, such as to explore the molecular mechanism of inhibition of germ tubes and biofilm formation and suppression of production of various hydrolytic enzymes by Candida spp.
The study aimed to find an effective method for fungal-mediated synthesis of zinc oxide nanoparticles using endophytic fungal extracts and to evaluate the efficiency of synthesized ZnO NPs as ...antimicrobial and anticancerous agents.
Zinc oxide nanoparticles (ZnO NPs) were produced from zinc nitrate hexahydrate with fungal filtrate by the combustion method. The spectroscopy and microscopy techniques, such as ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), and transmission electron microscopy (TEM) with selected area electron diffraction (SAED), were used to characterize the obtained product. Antibacterial activity on Gram-positive (
and
) and Gram-negative (
and
) samples was tested by broth microplate dilution technique. ZnO NPs antifungal activity was determined against plant pathogenic and regular contaminating fungi using the food-poison method. The anticancerous assay of the synthesized ZnO NPs was also investigated by cell uptake, MTT assay, and apoptosis assay.
The fungal synthesized ZnO NPs were pure, mainly hexagonal in shape and size range of 34-55 nm. The biosynthesized ZnO NPs could proficiently inhibit both Gram-positive and Gram-negative bacteria. ZnO NPs synthesized from fungal extract exhibited antifungal activity in a dose-dependent manner with a high percentage of mycelial inhibition. The cell uptake analysis of ZnO NPs suggests that a significant amount of ZnO NPs (1 μg/mL) was internalized without disturbing cancer cells' morphology. As a result, the synthesized ZnO NPs showed significant anticancer activity against cancer cells at 1 μg/mL concentration.
This fungus-mediated synthesis of ZnO NPs is a simple, eco-friendly, and non-toxic method. Our results show that the synthesized ZnO NPs are an excellent novel antimicrobial and anticancer agent. Further studies are required to understand the mechanism of the antimicrobial, anticancerous action of ZnO NPs and their possible genotoxicity.
Aims
The aim of this study is to investigate the antibacterial activity of aluminium oxide nanoparticles (Al2O3 NPs) against multidrug‐resistant clinical isolates of Escherichia coli and their ...interaction with cell envelope biomolecules.
Methods and Results
Al2O3 NPs were characterized by scanning electron microscope (SEM), high‐resolution transmission electron microscope (HR‐TEM) and X‐ray diffraction (XRD) analyses. Antibacterial activity and interaction of Al2O3 NPs with E. coli and its surface biomolecules were assessed by spectrophotometry, SEM, HR‐TEM and attenuated total reflectance/Fourier transform infrared (ATR‐FTIR). Of the 80 isolates tested, about 64 (80%) were found to be extended spectrum β‐lactamase (ESBL) positive and 16 (20%) were non‐ESBL producers. Al2O3 NPs at 1000 μg ml−1 significantly inhibited the bacterial growth. SEM and HR‐TEM analyses revealed the attachment of NPs to the surface of cell membrane and also their presence inside the cells due to formation of irregular‐shaped pits and perforation on the surfaces of bacterial cells. The intracellular Al2O3 NPs might have interacted with cellular biomolecules and caused adverse effects eventually triggering the cell death. ATR‐FTIR studies suggested the interaction of lipopolysaccharide (LPS) and L‐α‐Phosphatidyl‐ethanolamine (PE) with Al2O3 NPs. Infrared (IR) spectral changes revealed that the LPS could bind to Al2O3 NPs through hydrogen binding and ligand exchange. The Al2O3 NPs‐induced structural changes in phospholipids may lead to the loss of amphiphilic properties, destruction of the membrane and cell leaking.
Conclusions
The penetration and accumulation of NPs inside the bacterial cell cause pit formation, perforation and disorganization and thus drastically disturb its proper function. The cell surface biomolecular changes revealed by ATR‐FTIR spectra provide a better understanding of the cytotoxicity of Al2O3 NPs.
Significance and Impact of the Study
Al2O3 NPs may serve as broad‐spectrum bactericidal agents to control the emergent pathogens regardless of their drug‐resistance mechanisms.
Cadmium sulfide-graphitic carbon nitride nanocomposite was synthesized by pulsed laser ablation in liquid, and it was found from the results of optical and morphological characterizations that the ...proper anchoring of nanostructured cadmium sulfide on the nano-sheets of graphitic carbon nitride took place, which brought about the positive attributes such as enhanced visible light absorption and reduced photo-generated charge recombination, the key features required for an efficient photo-catalyst by solar light harvesting. The pulsed laser ablation in liquid method adopted for the synthesis of cadmium sulfide-graphitic carbon nitride has the following advantages: the shape and size of the synthesized particles can be controlled by altering the experimental parameters such as laser wavelength, pulse laser duration, the pH of the solution, the surfactants and the temperature of the solution, pulsed laser ablation in liquid method neither requires cumbersome equipment nor does it require intermediate chemicals and catalysts nor does it necessitate the post synthesis purification. The enhancement of photo-catalytic activity of cadmium sulfide-graphitic carbon nitride nanocomposite was tested for the photo-catalytic deactivation of Escherichia coli bacteria in water under visible light radiation. As anticipated, a significant improvement of photo-catalytic deactivation was observed, which is attributed to the enhanced and extended light absorption in the visible spectral region, and the formation of herterojunction between the semiconductors, which is instrumental in inhibiting the undesired recombination of photo-generated charge carriers. Quantitatively, the presence of cadmium sulfide on the graphitic carbon nitride surface contributed to a remarkable 129% increase of photo-catalytic degradation constant compared to pure graphitic carbon nitride, which resulted in the decrease of total depletion time of Escherichia coli from 156 min to 67 min with the cadmium sulfide-graphitic carbon nitride nanocomposite synthesized by pulsed laser ablation in liquid method. Our results on the efficient photo-catalytic deactivation of Escherichia coli under visible light assures that cadmium sulfide-graphitic carbon nitride nanocomposite can very well be used for photo-catalytic water purification by harvesting the abundant solar light.
•Anchoring of nanostructured CdS on g-C3N4 sheets using PLAL technique was performed.•Morphological, elemental and optical characterization of CdS@g-C3N4 was carried out.•Enhanced visible light absorption and reduced charge recombination were observed.•Efficient photo-catalytic deactivation of E. coli under visible light was observed.•A Prospective solar light harvesting using CdS@g-C3N4 can be applied.
•Co-application of biochar and fly ash could be a sustainable ecological engineering practice.•Combined application of biochar with fly ash increased maize crop yield by 28%.•The yield increase by ...biochar and fly ash is associated with increase in soil P.•Soil dehydrogenase activity, active microbial biomass, phosphatase and fluorescein diacetate hydrolases were increased significantly.
Worldwide, the fly ash, generated in huge quantities from thermal power plants is a menace, especially its handling and disposal. Utilization of fly ash as a soil amendment to improve soil quality has received a great deal of attention. Co-application of biochar with fly ash may further enhance soil quality and crop productivity. Field experiment was conducted in an acidic red soil, from Dhanbad, India, to investigate the effects of lignite fly ash (LFA) and biochar (BC) on soil nutrients, biological properties, and the yield of Zea mays. The treatments were (i) control, (ii) BC (4t/ha), (iii) LFA (4t/ha), and (iv) BC (2t/ha)+LFA (2t/ha). Soil samples were collected at three different crop stages of maize (vegetative, taselling and grain filling) and analyzed for pH, EC, organic carbon, N, P, K, soil enzymes, microbial biomass, and respiration. Soil bulk density and water holding capacity measured after the harvest of crop were not affected by the treatments. Soil P (+110%) and K (+64%) contents increased by LFA+BC application due to the presence of plant nutrient in BC and LFA. Soil enzymes like dehydrogenase activity (+60.7%), alkaline phosphatase (+32.2%), fluorescein hydrolases activity (12.3%) and microbial biomass (+25.3%) increased due to co-application of LFA and BC probably due to the pH-buffering and sorption of the organic matter to mineral surfaces to create a more reactive network for water, air and nutrient interactions in the soil. Available heavy metal (Zn, Ni, Co, Cu, Cd, and Pb) contents in soil decreased by LFA+BC application due to surface adsorption and precipitation caused by increase in soil pH. Maize grain yield increased by 11.4% for BC, 28.1% for BC+LFA treatment, and the yield was not significantly affected for the LFA alone treatment. Regression analysis showed soil P as the major factor for the increase in crop yield.
Purpose: Different approaches have been used for preventing biofilm-related infections in health care settings. Many of these methods have their own de-merits, which include chemical-based ...complications; emergent antibiotic resistant strains, etc. The formation of biofilm is the hallmark characteristic of Staphylococcus aureus and S. epidermidis infection, which consists of multiple layers of bacteria encased within an exopolysachharide glycocalyx. Nanotechnology may provide the answer to penetrate such biofilms and reduce biofilm formation. Therefore, the aim of present study was to demonstrate the biofilm formation by methicillin resistance S. aureus (MRSA) and methicillin resistance S. epidermidis (MRSE) isolated from wounds by direct visualisation applying tissue culture plate, tube and Congo Red Agar methods. Materials and Methods: The anti-biofilm activity of AgNPs was investigated by Congo Red, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) techniques. Results: The minimum inhibitory concentration (MIC) was found to be in the range of 11.25-45 μg/ml. The AgNPs coated surfaces effectively restricted biofilm formation of the tested bacteria. Double fluorescent staining (propidium iodide staining to detect bacterial cells and fluorescein isothiocyanate concanavalin A (Con A-FITC) staining to detect the exopolysachharides matrix) technique using CLSM provides the visual evidence that AgNPs arrested the bacterial growth and prevent the glycocalyx formation. In our study, we could demonstrate the complete anti-biofilm activity AgNPs at a concentration as low as 50 μg/ml. Conclusions: Our findings suggested that AgNPs can be exploited towards the development of potential anti-bacterial coatings for various biomedical and environmental applications. In the near future, the AgNPs may play major role in the coating of medical devices and treatment of infections caused due to highly antibiotic resistant biofilm.
Aims: To determine the stability and conidial yield of two strains of the entomopathogenic fungus Metarhizium anisopliae and one strain of M. brunneum, being developed for the control of insect ...pests. Methods and Results: The conidial yields and the shelf-life of the conidia of two commercially viable strains of M. anisopliae V275 (=F52) and ARSEF 4556 and one strain of M. brunneum (ARSEF 3297) were determined after harvesting conidia from in vitro subcultures on Sabouraud dextrose agar (SDA) and broken basmati rice. The strains were stable and showed no decline in virulence against Tenebrio molitor, even when subcultured successively 12 times on SDA. Conidia-bound Pr1 protease activity decreased in conidia harvested from SDA and mycosed cadavers after the 1st subculture, but increased in conidia produced on rice. The C:N ratio of conidia from mycosed cadavers was lower than that of conidia from rice or SDA. Irrespective of the number of subcultures, strain ARSEF 4556 produced significantly higher conidial yields than ARSEF 3297 and V275. The 12th subculture of V275 and ARSEF 3297 produced the lowest conidial yield. Shelf-life studies showed that conidia of strain ARSEF 4556 had a higher conidial viability than V275 and ARSEF 3297 after 4 months, stored at 4°C. Conclusions: The current study shows that determining strain stability and conidial yield through successive subculturing is an essential component for selecting the best strain for commercial purposes. Significance and Impact of the Study: This is the first study to compare quality control parameters in the production of conidia on rice, and it shows that the level of Pr1 is comparatively high for inoculum produced on rice.
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