2,309 research outputs found
Analysis of Variations in Biomolecules during Various Growth Phases of Freshwater Microalgae Chlorella sp.
Background and Objective: Because of the presence of compounds with pharmacological effects crucial to human health, Chlorella is one of the most researched microalgae. For the targeted extraction of particular chemicals, it is crucial to evaluate these changes during the various growth phases, as the diversity of biomolecules in the cell changes with growth.
Material and Methods: Chlorella sp. was isolated from a freshwater pond, and three different solvent solutions were used to phytoextract biomass taken at three different growth phases (Log phase, Early stationary phase, and Late stationary phase) (Ethanol, Methanol, and Acetone). Extracts from various growth phases were subjected to qualitative analysis (antioxidant activity), quantitative analyses (total phenolic and flavonoid content), and fatty acid analyses.
Results and Conclusion: Total flavonoid concentration was highest during the late stationary growth phase as opposed to the early growth stages. In contrast, total phenolic content was highest in the log phase. Different growth phases differed in the number and quantity of biological components present, according to a GC-MS study of extracts. Compared to the late stationary phase, the early growth phases of the algae showed higher levels of ω-3 and ω-6 polyunsaturated fatty acids, according to the fatty acid profile. The results show that the quantity and nature of phytoconstituents in the extract changed with the solvent system and were time-dependent. Positive correlations between the total phenolic content and polyunsaturated fatty acids and the DPPH free radical scavenging assay demonstrate that the quantity and type of phytoconstituents depend on the stages of algal growth. The potential of Chlorella sp. for commercial use would be further increased by additional studies of the variables impacting the individual fatty acids and entire fatty acids profiles during the specific growth phases
Collective dynamics of active dumbbells near a circular obstacle
In this article, we present the collective dynamics of active dumbbells in
the presence of a static circular obstacle using Brownian dynamics simulation.
The active dumbbells aggregate on the surface of a circular obstacle beyond a
critical radius. The aggregation is non-uniform along the circumference, and
the aggregate size increases with the activity and the curvature radius. The
dense aggregate of active dumbbells displays persistent rotational motion with
a certain angular speed, which linearly increases with the activity. Further,
we show the strong polar ordering of the active dumbbells within the aggregate.
The polar ordering exhibits a long-range correlation, with the correlation
length corresponding to the aggregate size. Additionally, we show that the
residence time of an active dumbbell on the obstacle surface grows rapidly with
area fraction due to many-body interactions that lead to a slowdown of the
rotational diffusion. The article further considers the dynamical behavior of a
tracer particle in the solution of active dumbbells. Interestingly, the speed
of the passive tracer particle displays a crossover from monotonically
decreasing to increasing with the tracer particle's size upon increasing the
dumbbells' speed. Furthermore, the effective diffusion of the tracer particle
displays the non-monotonic behavior with area fraction; the initial increase of
the diffusivity is followed by a decrease for larger area fraction.Comment: 14 pages, 23 figure
Study of Sericulture & Cocoon Production in Janjgir- Champa Diistrict of Chhattisgarh (India)
Sericulture is a growing business for rural development since it integrates well with farming practices and has the ability to produce lucrative income all year round. It boasts affordable startup costs and offers jobs all year round. Sericulture, a cottage and small-scale industry, is a labor-intensive, economically appealing, and environmentally friendly form of agriculture. Per square meter of land, sericulture produces a lot of work and cash. Sericulture offers many opportunities for improving human resource employability and can successfully slow down population migration to cities. When compared to other crop operations in terms of generating money, sericulture is the most lucrative. The cultivation of mulberries, the generation of silkworm seeds, the rearing of silkworms, the reeling and weaving of silk, the collecting of byproducts, and their processing are all aspects of the sericulture industry that generate a significant amount of work and, consequently, a source of income for rural and tribal people. Sericulture is recognized as a thriving rural sector primarily because it offers families and labor year-round, remunerative employment, and also guarantees periodic income even with tiny land holdings
The influence of hot melt subcoat and Polymer coat combination on highly water soluble sustained release multiparticulate formulation
The purpose of this study was to develop and optimize oral controlled-release formulations for highly water soluble model drug Venlafaxine hydrochlorid using a combination of hot-melt subcoating s based coating polymerand aqueous polymer coating. Hot melt subcoating was achieved by centrifugal granulator. For the polymer coating, Acrylate-based (Eudragit RS 30D and Eudragit NE 30D), were used. Furthermore polymer coating, the pellets were evaluated with respect to their ability to modulate the in-vitro release of a highly water soluble compound. By using hot melt subcoating, the polymer coating level of pellets was reduced by half to obtain sustained release profile. In this study, the release profile of pellets was found to be optimum at a 4% level of hot melt subcoating and 15 % level of Eudragit® NE30D polymer coating combination, consequently meeting the desired responses. The release profile of the pellets prepared by this technique satisfied the first order plot with (R sq =0.9434) indicating the release of water soluble drug from porous matrices. By means of this hot-melt subcoating and polymer coating combination, sustained-release pellets containing venlafaxine hydrochloride were successfully prepared
ASEP of MIMO System with MMSE-OSIC Detection over Weibull-Gamma Fading Channel Subject to AWGGN
Ordered successive interference cancellation (OSIC) is adopted with minimum mean square error (MMSE) detection to enhance the multiple-input multiple-output (MIMO) system performance. The optimum detection technique improves the error rate performance but increases system complexity. Therefore, MMSE-OSIC detection is used which reduces error rate compared to traditional MMSE with low complexity. The system performance is analyzed in composite fading environment that includes multipath and shadowing effects known as Weibull-Gamma (WG) fading. Along with the composite fading, a generalized noise that is additive white generalized Gaussian noise (AWGGN) is considered to show the impact of wireless scenario. This noise model includes various forms of noise as special cases such as impulsive, Gamma, Laplacian, Gaussian, and uniform. Consequently, generalized Q-function is used to model noise. The average symbol error probability (ASEP) of MIMO system is computed for 16-quadrature amplitude modulation (16-QAM) using MMSE-OSIC detection in WG fading perturbed by AWGGN. Analytical expressions are given in terms of Fox-H function (FHF). These expressions demonstrate the best fit to simulation results
Body image perception, eating attitude and influence of media among undergraduate students of medical college in Delhi: a cross sectional study
Background: Body image perception is being shaped by unrealistic ideals portrayed in the media. Body dissatisfaction is one of the most consistent and robust risk factors for eating disorders, low self-esteem, depression, and obesity. Therefore, the objective of the current study is to ascertain the body image perception, abnormal eating attitudes and the role of media among undergraduate students of a medical college in Delhi, India.Methods: Cross-sectional study on 370 undergraduate medical students of Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India selected using stratified random sampling. India. Students completed a self-administered questionnaire which consist of demographic information, perceived body image, Eating Attitudes test (EAT-26) to assess eating attitudes, Socio Cultural Attitude Towards Appearance Questionnaire 3(SATAQ-3) scale for the role of media on body image perception. Data was analyzed using SPSS v21.Results: A total of 370 students (57.6% males and 42.4% females) aged 17-30 years, mean age of 20.30 years±2.02(SD). Abnormal body image perception was seen in 35.4%, 21.1% had abnormal eating attitude (EAT-26≥20), 36.5%, 40.5% agreed to be influenced by models and athletic figures in media respectively, 42.2% accepted that media was their source of information regarding standards of attractiveness, 27.6% felt pressured to be attractive according to SATAQ-3. Males more than females had disordered eating attitudes and felt media pressure to achieve an ideal body image. Significant association was observed between age and perceived body image (p=0.033), gender and EAT-26 score (p=0.039), EAT 26 and perceived body image (p=0.006), general internalization of media and perceived body image (p=0.003), internalization-general, internalization-athlete, media as source of information and EAT-26 score (<0.001, 0.001, 0.003 respectively).Conclusions: The media should take more responsibility to not represent unrealistic ideals of body image concerning both males and females. Educational and preventive efforts at institutional levels should be made to promote a healthy body image and eating behaviours
Formulation and Multivariate optimization of Microcrystalline Cellulose Pellets of highly water soluble drug
Microcrystalline Cellulose (MCC) pellets containing highly water soluble compound A was formulated with highestpellet usable yield of 86%, aspect sphericity that is (aspect ratio less than1.1 and roundness greater than 0.85), minimum friability of 0.33% by extrusionand Spheronization technique. A Central Composite Design (CCD) was executed to estimate the effect of formulation and processvariable namely water (21-41%), spheronization time (1-9 min) andSpheronization speed (200-800) to maximize responses i.e, usable yield, Sphericityaspect ratio and roundness. Least square regression analysis using responsesurface methodology permit the identification and optimization of variablesthat shows significant effect on selected responses. Polynomial model fitted tothe data were used to predict the responses in the desired value. A generalizeddesirability function is used to get maximum achievable target for responses.The optimum values for variables were water 31%, Spheronization Time of 5 minand Spheronization speed of 500 rpm. These results confirmed the usefulness of Multivariateanalysis to identify the critical variables and their interactions on thecharacteristics of pelletizatio
Decision and coordination of WEEE closed-loop supply chain with risk aversion under the cap-and-trade regulation
Driven by the soaring consumption of electrical and electronic equipment (EEE), the semiconductor industry is facing sustainable development challenges such as energy management and carbon emissions. The waste electrical and electronic equipment (WEEE) management practice could contribute to achieving sustainability in the semiconductor industry through the remanufacturing business. Considering the collection quality heterogeneity and its potential influences on the WEEE remanufacturing process, this paper tries to explore the decision-making strategy and coordination mechanism of the WEEE closed-loop supply chain (CLSC) under the cap-and-trade regulation (CATR). The Stackelberg game model is formulated to address this context consisting of a manufacturer with risk avoidance and a retailer with risk neutrality. Besides, we disclose the specific influence of WEEE collection quality on the strategic decision-making of CLSC members under decentralized and centralized modes. Additionally, the revenue and cost-sharing contract is designed to facilitate coordination within the CLSC, and numerical experiments are performed to help better understand the strategic decision-making and effectiveness of the designed contract mechanism. Results show that within a certain threshold of WEEE collection quality, both recycling rate and total profit increase as collection quality improves, while unit wholesale and retail prices of EEE decrease. Conversely, as the risk aversion of the manufacturer increases, the return rate of WEEE decreases, while the wholesale price and retail price per unit of EEE rise. Under the joint influence of the unit carbon emission quota trading price and risk aversion, the unit carbon emission quota trading price exacerbates the impact of manufacturer risk aversion on the return rate. The revenue and cost-sharing contract also contributes to achieving WEEE CLSC coordination under specific conditions
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