A Solar PV Based Multistage Grid Tie Inverter

The inherent advantage of fuel less and maintenance free energy production from solar photovoltaic makes it a very important source of energy. For harnessing power from the solar photovoltaic (PV) cell/array and to supply it to the utility grid, dc to ac inverters is needed. The conventional line commutated dc-to-ac inverter has square shaped line current which contains higher order harmonics whereas PWM based inverters employing IGBT/ MOSFET are less reliable and has low power handling capability. Moreover, a dc-to-dc converter is generally employed along with the inverter circuit to operate the solar PV array at maximum power point. It adds to the cost, which increases with the size of the system. This paper describes a multistage series converter topology for solar PV based grid tie inverter with low harmonic in line current and inbuilt maximum power point tracking (MPPT) features. The developed prototype has been experimentally tested and verified.Keywords: Multistage converter, Grid tie inverter, Maximum power point tracker (MPPT), Total harmonic distortion, photovoltaic system

Integrated Network Pharmacology and In-Silico Molecular Docking Studies to Unveil Mechanism of Action of Polyphenolic Compounds of Psidium Guajava for The Management of Thrombocytopenia

Despite considerable studies, thrombocytopenia is still affecting millions of people with an increasing rate of morbidity and mortality around the globe. Therefore, we aimed to identify pharmacologically active polyphenolic compounds such as quercetin, apigenin and kaempferol in Psidium guajava for the management of thrombocytopenia using network pharmacology and in-silico molecular docking. The results of ADME/Tox screening revealed that all the polyphenolic compounds possess the drug-likeness activity and were found safe. Moreover, network pharmacology revealed that polyphenolic compounds of Psidium guajava may combat diabetes by acting on key targets, such as MAPK, TP53 and TNF-α which were strongly involved in oxidative stress, inflammatory responses and blood-related parameters involved in thrombocytopenia. Further, a mechanistic approach through molecular docking also supports the strong binding sites of quercetin, apigenin and kaempferol. Conclusively, in-silico ADME, molecular docking and network pharmacology study revealed that identified compounds are safe and pharmacologically effective. These identified compounds could be a great source for the development of new anti-thrombocytopenic drugs in the future

Preparation and characterization of silver nanoparticles using aniline

AbstractUV–Vis spectroscopy, transmission electron microscopy (TEM) and selected area electron diffraction (SAED) have been employed to characterize silver nanoparticles (AgNPs) using aniline and silver nitrate as reductant and oxidant, respectively. A broad surface resonance plasmon (SRP) band appears at 400nm, indicating that the AgNPs are spherical. The TEM images show that AgNPs aggregated in an unsymmetrical manner, leading to the formation of beautiful silver nanocrystals. Aniline adsorbed onto the surface of Ag-nanocrystals through electrostatic, van der Walls forces and hydrogen bonding. Cetyltrimethylammonium bromide (CTAB) acted as a stabilizer and/or capping agent

Organization Performance Influenced by the BSD and Consultative Management Style

The purpose of this study is to investigate the relationship among Balanced Scorecard, consultative management style, participative management style and organization size with organizational performance. All the variables are highly correlated with each other. This is an empirical study and data is collected from 100 respondents of service sector from Azad Kashmir. We used five likert scales to collect data from the respondents and data analyzed through SPSS. The result showed that there is a significant positive correlation among variables. This study also indicates that effective management style is necessary for improving the performance of organization. The result indicates that Balanced Scorecard has significant impact on performance of organization. Organization use BSC to handle the complexity and challenges that management faces during their operations. The collection of data is from small area due to time constraint. In the future comparative study can be done with other organizations for better analysis of results

Bioavailability and Metabolic Pathway of Phenolic Compounds

As potential agents for preventing different oxidative stress-related diseases, phenolic compounds have attracted increasing attention with the passage of time. Intake of fruits, vegetables and cereals in higher quantities is linked with decreased chances of chronic diseases. In plant-based foods, phenolic compounds are very abundant. However, bio-accessibility and biotransformation of phenolic compound are not reviewed in these studies; therefore, a detailed action mechanism of phenolic compounds is not recognized. In this article, inclusive concept of different factors affecting the bioavailability of phenolic compounds and their metabolic processes is presented through which phenolic compounds go after ingestion

Curcumin: A Mini Review on its Synthetic Derivatives

Curcumin is a fat-soluble natural substance obtained from Curcuma longa and finds its applications in treatment of numerous disorders and diseases. Apart from its vast pharmacological profile, it is also used as a flavoring agent in the Asian subcontinent. This has drawn attention of the scientists to use it as an important scaffold to prepare its synthetic derivatives in order to improve the efficacy as well as potency of drug molecules and also reducing their toxicity effects. Here we tried to give some deeper insights of curcumin with a focus on its biological activities and various synthetic derivatives with a view to get potential lead molecules for future drug discovery and expansion of its medicinal profile

Knowledge, awareness and practices regarding dengue fever among the adult population of dengue hit cosmopolitan.

Background: The World health Organization (WHO) declares dengue and dengue hemorrhagic fever to be endemic in South Asia. Despite the magnitude of problem, no documented evidence exists in Pakistan which reveals the awareness and practices of the country\u27s adult population regarding dengue fever, its spread, symptoms, treatment and prevention. This study was conducted to assess the level of knowledge, attitudes and practices regarding dengue fever in people visiting tertiary care hospitals in Karachi, Pakistan. Methods: A cross-sectional pilot study was conducted among people visiting tertiary care hospitals in Karachi. Through convenience sampling, a pre-tested and structured questionnaire was administered through a face-to-face unprompted interview with 447 visitors. Knowledge was recorded on a scale of 1-3. Results: About 89.9% of individuals interviewed had heard of dengue fever. Sufficient knowledge about dengue was found to be in 38.5% of the sample, with 66% of these in Aga Khan University Hospital and 33% in Civil Hospital Karachi. Literate individuals were relatively more well-informed about dengue fever as compared to the illiterate people (p\u3c0.001). Knowledge based upon preventive measures was found to be predominantly focused towards prevention of mosquito bites (78.3%) rather than eradication of mosquito population (17.3%). Use of anti-mosquito spray was the most prevalent (48.1%) preventive measure. Television was considered as the most important and useful source of information on the disease.Conclusion: Adult population of Karachi has adequate knowledge related to the disease \u27dengue\u27 on isolated aspects, but the overall prevalence of \u27sufficient knowledge\u27 based on our criteria is poor. We demonstrated adequate prevalence of preventive practices against the disease. Further studies correlating the association between knowledge and its effectiveness against dengue will be helpful in demonstrating the implications of awareness campaigns

A randomized, double-blind, placebo-controlled trial of oral montelukast in acute asthma exacerbation.

Background: Leukotriene receptor antagonists (LTRAs) are well established in the management of outpatient asthma. However, there is very little information as to their role in acute asthma exacerbations. We hypothesized that LTRAs may accelerate lung function recovery when given in an acute exacerbation. Methods: A randomized, double blind, placebo-controlled trial was conducted at the Aga Khan University Hospital to assess the efficacy of oral montelukast on patients of 16 years of age and above who were hospitalized with acute asthma exacerbation. The patients were given either montelukast or placebo along with standard therapy throughout the hospital stay for acute asthma. Improvements in lung function and duration of hospital stay were monitored. Results: 100 patients were randomized; their mean age was 52 years (SD +/− 18.50). The majority were females (79%) and non-smokers (89%). The mean hospital stay was 3.70 ± 1.93 days with 80% of patients discharged in 3 days. There was no significant difference in clinical symptoms, PEF over the course of hospital stay (p = 0.20 at day 2 and p = 0.47 at day 3) and discharge (p = 0.15), FEV1 at discharge (p = 0.29) or length of hospital stay (p = 0.90) between the two groups. No serious adverse effects were noted during the course of the study. Conclusion: Our study suggests that there is no benefit of addition of oral montelukast over conventional treatment in the management of acute asthma attack

Investigation of the cardiac depressant effect of Caralluma tuberculate N.E.Br on isolated rabbit heart

Purpose: To investigate the histopathological and cardiac depressant effect of the aqueous methanol extract of Caralluma tuberculata N.E. Br (AMECT) (family: Asclepiadaceae)’ and to determine if there is a scientific basis for its cardiovascular diseases-related folkloric use. Methods: The effect of AMECT in different concentrations ranging from 0.00001 to 1.0 mg/mL were evaluated in isolated perfused rabbit heart to assess their effect on the force of contraction and heart rate using Langendorff’s apparatus. Atropine and adrenaline were used to identify the underlying mechanism of response produced by AMECT. The extract was studied for its possible mechanism in the absence and presence of atropine and adrenaline. In addition, sub-chronic toxicity and histopathological study of heart tissues in rats were assessed by administering 500 mg/kg of extract. Results: At all concentrations, AMECT produced significant (p < 0.001) negative ionotropic and negative chronotropic effects. The most significant effect was observed at 0.001 mg/mL and higher concentrations hence 0.001 mg/mL was selected for further studies. Pre-incubation with atropine did not significantly inhibit the effects of AMECT. However, AMECT significantly (p < 0.01) blocked the cardiac stimulant effect of adrenaline. In the histopathological studies, AMECT did not produce any significant cellular changes or signs of toxicity in the sub-chronic toxicity study. Conclusion: The cardiac-depressant responses of AMECT may involve the β-adrenergic receptors in the myocardium of isolated rabbit heart thus confirming the rationale for its use in ethnomedicine for cardiac diseases

Gray matter atrophy in multiple sclerosis despite clinical and lesion stability during natalizumab treatment

Background: Brain volume loss is an important surrogate marker for assessing disability in MS; however, contribution of gray and white matter to the whole brain volume loss needs further examination in the context of specific MS treatment.Objectives: To examine whole and segmented gray, white, thalamic, and corpus callosum volume loss in stable patients receiving natalizumab for 2-5 years.Methods: This was a retrospective study of 20 patients undergoing treatment with natalizumab for 24-68 months. Whole brain volume loss was determined with SIENA. Gray and white matter segmentation was done using FAST. Thalamic and corpus callosum volumes were determined using Freesurfer. T1 relaxation values of chronic hypointense lesions (black holes) were determined using a quantitative, in-house developed method to assess lesion evolution.Results: Over a mean of 36.6 months, median percent brain volume change (PBVC) was -2.0% (IQR 0.99-2.99). There was decline in gray (p = 0.001) but not white matter (p = 0.6), and thalamic (p = 0.01) but not corpus callosum volume (p = 0.09). Gray matter loss correlated with PBVC (Spearman's r = 0.64, p = 0.003) but not white matter (Spearman's r = 0.42, p = 0.07). Age significantly influenced whole brain volume loss (p = 0.010, multivariate regression), but disease duration and baseline T2 lesion volume did not. There was no change in T1 relaxation values of lesions or T2 lesion volume over time. All patients remained clinically stable.Conclusions: These results demonstrate that brain volume loss in MS is primarily driven by gray matter changes and may be independent of clinically effective treatment.</div