98 research outputs found
Switchable resolution in soft x-ray tomography of single cells.
The diversity of living cells, in both size and internal complexity, calls for imaging methods with adaptable spatial resolution. Soft x-ray tomography (SXT) is a three-dimensional imaging technique ideally suited to visualizing and quantifying the internal organization of single cells of varying sizes in a near-native state. The achievable resolution of the soft x-ray microscope is largely determined by the objective lens, but switching between objectives is extremely time-consuming and typically undertaken only during microscope maintenance procedures. Since the resolution of the optic is inversely proportional to the depth of focus, an optic capable of imaging the thickest cells is routinely selected. This unnecessarily limits the achievable resolution in smaller cells and eliminates the ability to obtain high-resolution images of regions of interest in larger cells. Here, we describe developments to overcome this shortfall and allow selection of microscope optics best suited to the specimen characteristics and data requirements. We demonstrate that switchable objective capability advances the flexibility of SXT to enable imaging cells ranging in size from bacteria to yeast and mammalian cells without physically modifying the microscope, and we demonstrate the use of this technology to image the same specimen with both optics
Coherent Multiphoton Control of Gallium Phosphide Nanodisk Resonances
High-index dielectric nanoantennas have recently emerged as promising alternatives to plasmonic nanoantennas for concentrating and manipulating light at the nanoscale. For example, gallium phosphide (GaP) nanoantennas display extremely low losses in the visible range and high nonlinearities, support both electric and magnetic resonances, and are nicely compatible with CMOS fabrication technology. Especially, the low losses and large nonlinearities are promising for ultrafast optical switching and truly all-optical control of GaP nanodevices. Here first we use two- and three-photon excitation of GaP nanodisks to probe the size-dependent resonance enhancement of second-harmonic and bandgap emission. Next, we show, by spectral phase control of broadband pulsed excitation, that GaP nanoantennas outperform their metal counterparts in supporting nonlinear optical coherences.Peer ReviewedPostprint (author's final draft
Parental Wellbeing and Clinical Characteristics of Children with Intellectual Disability
This study aimed to see the psychological well-being of the caregivers and its relationship with the clinical characteristics of children with Intellectual Disability (ID).
Methods: A total of 20 caregivers of children with intellectual disability were purposively selected from Central Institute of Psychiatry and Deepshika Institute of Child Development and Mental Health, Ranchi. Socio-demographic and clinical data of caregivers and their children with intellectual disability was collected using specially designed clinical datasheet. The caregivers were assessed with General Health Questionnaire-28 (GHQ-28), Ryff’s Psychological wellbeing scale, Family Interview for Stress and Coping in Mental Retardation (FISC-MR), Social Problem-Solving Inventory (SPSI-R) and Self-determination scale (SDS). Intelligence quotient of the child was assessed with the average score of VSMS and DST and percentage of disability using Assessment of Disability in Persons with Mental Retardation (ADPMR).
Results & Conclusions: Study identified a significant relationship in the caregiver’s psychological well-being associated with the clinical characteristics of children with intellectual disability. There is decreased psychological wellbeing in the caregivers and is related to the clinical characteristics of the children with intellectual disability. There are very few culturally sensitive parent intervention practices directed to the key caregivers of children with intellectual disability and that these practices should be enhanced
Fast photochronoamperometry of photosynthetic complexes for biosensors and electron transport studies
Photosynthetic reactions in plants, algae, and cyanobacteria are driven by photosystem I and photosystem II complexes, which specifically reduce or oxidize partner redox biomolecules. Photosynthetic complexes can also bind synthetic organic molecules, which inhibit their photoactivity and can be used both to study the electron transport chain and as herbicides and algicides. Thus, their development, characterization, and sensing bears fundamental and applied interest. Substantial efforts have been devoted to developing photosensors based on photosystem II to detect compounds that bind to the plastoquinone sites of this complex. In comparison, photosystem I based sensors have received less attention and could be used to identify novel substances displaying phytotoxic effects, including those obtained from natural product extracts. We have developed a robust procedure to functionalize gold electrodes with photo- and redox-active photosystem I complexes based on transparent gold and a thiolate self-assembled monolayer, and we have obtained reproducible electrochemical photoresponses. Chronoamperometric recordings have allowed us to measure photocurrents in the presence of the viologen derivative paraquat at concentrations below 100 nM under lock-in operation and a sensor dynamic range spanning six orders of magnitude up to 100 mM. We have modeled their time course to identify the main electrochemical processes and limiting steps in the electron transport chain. Our results allow us to isolate the contributions from photosystem I and the redox mediator, and evaluate photocurrent features (spectral and power dependence, fast transient kinetics) that could be used as a sensing signal to detect other inhibitors and modulators of photosystem I activity.Peer ReviewedPostprint (author's final draft
Therapeutic potential of oleic acid nanovesicles prepared from petroleum ether extract of Sargassum binderi in streptozotocin–induced diabetic wound in Wistar rats
Purpose: To study the effectiveness of phyto-oleic acid nanovesicles (PONVs) developed from Sargassum binderi (an alga) in healing diabetic wound in a rat model, and to establish the associated changes in cytokine network.Methods: Phyto-extract was obtained from the whole plant of Sargassum binderi by Soxhlet extraction using petroleum ether as solvent. The crude extract was subjected to phytochemical analysis and used in the formulation of POVNs. The PONVs were formulated by entrapping petroleum ether extract of Sargassum binderi using the film hydration technique. Wound healing property was determined by measuring both pro-inflammatory and anti-inflammatory cytokines using enzyme-linked immunosorbent assay (ELISA).Results: Tannins and steroids were the major components of the petroleum ether extract of Sargassum binderi. Serum cytokine levels were increased after inducing diabetes and creating the wound. The serum levels of IL-2, TNF-α and IL-1β were 37.3 ± 3.3, 76.3 ± 5.2 and 3307.6 ± 350 pg/ml, respectively. Treatment with PONVs modulated the serum cytokine levels through significant decreases in serum IL-2, TNF-α, IL-1β levels, and significant elevation of serum IL-4.Conclusion: These results indicate that PONVs have promising potentials for application as topical treatment for diabetic wounds.Keywords: Brown algae, Sargassum binderi, Oleic acid nanovesicles, Diabetic wound, Cytokine
A novel approach for reducing water stress on sunflower plants by using medicinal plant extracts rather than artificial growth regulators
One of the most significant physiological stressors that negatively impact plants in numerous vital areas of their growth and metabolism is water stress. This study estimates the effects of natural bio-stimulants (Origanum majorana, Nigella sativa and Curcurma longa) extracts for the first time, on water stress of sunflower plant in comparison with synthetic growth regulators (glycein betaine, proline, indole acetic acid, benzyl adenine and ascorbic acid). Water stress appeared to decrease of lengths, fresh and dry weights of shoot and root. Also caused a significant drop in chlorophylls and carotenoids. Foliar application of these synthetic and natural growth regulators significantly decreased the negative effects of drought stress on all studied morphological parameters and pigment contents of sunflower. HPLC analysis of bio-stimulants appeared six phenolic acids, one phenol and two flavonoids were found in all natural extracts. Gallic, rosmarinic, caffeic, syringic acids and kaempferol are the major phenolic compounds (more than 1000 µg/g) detected in Origanum majorana. While gallic acid, hesperetin and ferulic acid are the major phenolic compounds (more than 1000 µg/g) present in Curcurma longa. Chlorogenic acid, gallic acid, catechin, pyro catechol, coffeic acid and rutin are the dominant phenolic compounds present in Nigella sativa. The Nigella sativa treatment showed the highest decrease in proline levels. This may be due to the high concentration of caffeic acid (2406.97 g/g). The Origanum majorana treatment had the highest levels of chl. a and carotenoid contents, which rose by about 32% and 72%, respectively, compared to the stress-treated plant. The highly decrease in catalase activity, which is considered as most important indicator to water stress, appeared in Origanum majorana treatment. We suggest the use of these natural extracts as an alternative way, which appeared a significant increase in growth and biochemical near to synthetic regulators in the treatment of water stress due to the fact that these extracts contain many important phenolic compounds that have a role in the treatment of water stress
Social Assistance in Developing Countries Database Version 5.0
The Social Assistance in Developing Countries Database is a user-friendly tool that provides summary information on social assistance interventions in developing countries. It provides a summary of the evidence available on the effectiveness of social assistance interventions in developing countries. It focuses on programmes seeking to combine the reduction and mitigation of poverty, with strengthening and facilitating household investments capable of preventing poverty and securing development in the longer term. The inclusion of programmes is on the basis of the availability of information on design features, evaluation, size, scope, or significance. Version 5 of the database updates information on existing programmes and incorporates information on pilot social assistance programmes in Latin America, Asia and Africa. It also adopts a new typology that distinguishes between social assistance programmes providing pure income transfers; programmes that provide transfers plus interventions aimed at human, financial, or physical asset accumulation; and integrated poverty reduction programmes. This new typology has, in our view, several advantages. It is a more flexible, and more accurate, template with which to identify key programme features. It provides a good entry point into the conceptual underpinnings of social assistance programmes
Numerical Study of Reinforced Concrete beam subjected to blast loading using Finite element package ABAQUS
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