Modeling, simulation and implementation of low power photovoltaic energy conversion system

Remote areas in India are still not connected to the power grid. But they have mobile network connectivity. The people face problems in charging their cell phones. They are forced to travel a long distances to get access to electrical outlets. This project focuses on providing a Photovoltaic System which could charge a cell phone battery. The developed system provides a solution to this problem. The system comprises of PV array, Maximum Power Point Tracker, Buck Converter and Charging Circuit. The system is modeled and simulated in Matlab-Simulink Environment. Hardware for the system is also implemented. We find proper synchronism between the results

Application of nanotechnology in antimicrobial finishing of biomedical textiles

In recent years, the antimicrobial nanofinishing of biomedical textiles has become a very active, high-growth research field, assuming great importance among all available material surface modifications in the textile industry. This review offers the opportunity to update and critically discuss the latest advances and applications in this field. The survey suggests an emerging new paradigm in the production and distribution of nanoparticles for biomedical textile applications based on non-toxic renewable biopolymers such as chitosan, alginate and starch. Moreover, a relationship among metal and metal oxide nanoparticle (NP) size, its concentration on the fabric, and the antimicrobial activity exists, allowing the optimization of antimicrobial functionality.Andrea Zille (C2011-UMINHO-2C2T-01) acknowledges funding from Programa Compromisso para a Ciencia 2008, Portugal

Role of long-range coupling on the properties of single polarons in models with dual electron-phonon couplings

We use the Variational Exact Diagonalization to investigate the single polaron properties for four different dual models, combining a short-range off-diagonal (Peierls) plus a longer-range diagonal (Holstein or breathing-mode) coupling. This allows us to investigate the sensitivity of various polaron properties both to the range of the diagonal coupling and to the specific diagonal coupling chosen. We find strong sensitivity to the range for all duals models as the adiabatic limit is approached, however considerable sensitivity is observed for some quantities even for large phonon frequencies. Also, the strong dependence of the results on the specific form of the diagonal coupling is observed everywhere in the parameter space. Taken together, these results suggest that careful consideration must be given to the specific coupling and its proper range when quantitative comparisons with experiments are sought.Comment: 9 pages, 12 figures, submitted to Physical Review

Bacterial colonization of stethoscope used in the tertiary care teaching hospital: a potential source of nosocomial infection

Background: Hospital acquired infections (HAI) are a major problem in each hospital. HAI remains a significant hazard for hospitalized patients and health care workers are potential sources of these infections. Health care workers can transmit pathogens through their hands and contaminated medical devices such as stethoscopes, Blood pressure cuff etc. Hence we intended to determine the level of bacterial contamination of stethoscopes using in present hospital.Methods: Total of 50 stethoscopes were sampled before and after cleaning with 70% isopropyl alcohol by using sterile swab soaked in sterile saline. Samples were processed as per standard microbiological procedures.Results: Out of 50 stethoscopes, 30 (60%) stethoscopes were showing significant bacterial colonization, 7 (14%) showed insignificant colonization, and in 13 (26%) stethoscopes no growth was observed. The bacteria isolated were Methicillin Resistant Staphylococcus aurues (MRSA) (14%), Methicillin Sensitive Staphylococcus aureus (MSSA) (12%), Coagulase Negative Staphylococcus (CNS) (14%), Klebsiella species (20%).Conclusions: Our study concluded that stethoscopes used by health care workers were colonized by both pathogens and non-pathogenic microorganisms. Strict protocol of cleaning the stethoscopes in between the patients will eliminate the colonization and there by spread of infections

Formulation and evaluation of herbal face cream with green tea extract

Face cream is a semi-solid preparation for improving skin colour. The purposes of the present research work was to formulate and evaluate herbal face cream with green tea extract, turmeric, aloe vera gel as a skin toner. Herbal creams offer several advantages over synthetic creams. The majority of existing creams which has prepared from drugs of synthetic origin and gives extras fairness to face, but it has several side effects such as itching or several allergic reactions. Herbal creams do not have any of these side effects, without side effects it gives the nourishment to skin. Method carried out to prepare herbal cream was vanishing cream formulation. Firstly, oil phase was prepared, Secondly aqueous phase was prepared. Then aqueous phase was added into the oil phase at 700 c with continuous stirring. Now, once the transfer was completed it was allowed to come at room temperature all the while being stirred. Perfume was added at last just before the finished product was transferred to suitable container. The above prepared herbal cream was evaluated with parameters such as pH, homogeneity by visual and by touch, appearance (colour), rub out (spread ability, wetness), washability, consistency and emolliency. The study suggests that the composition of extract and the base of the cream F1 are more stable and safe

Microbial surfactants: fundamentals and applicability in the formulation of nano-sized drug delivery vectors

Microbial surfactants, so-called biosurfactants, comprise a wide variety of structurally distinct amphipathic molecules produced by several microorganisms. Besides exhibiting surface activity at the interfaces, these molecules present powerful characteristics including high biodegradability, low toxicity and special biological activities (e.g. antimicrobial, antiviral, anticancer, among others), that make them an alternative to their chemical counterparts. Several medical-related applications have been suggested for these molecules, including some reports on their potential use in the formulation of nano-sized drug delivery vectors. However, despite their promises, due to the generalized lack of knowledge on microbial surfactants phase behavior and stability under diverse physicochemical conditions, these applications remain largely unexplored, thus representing an exciting field of research. These nano-sized vectors are a powerful approach towards the current medical challenges regarding the development of efficient and targeted treatments for several diseases. In this review, a special emphasis will be given to nanoparticles and microemulsions. Nanoparticles are very auspicious as their size, shape and stability can be manipulated by changing the environmental conditions. On the other hand, the easiness of formulation, as well as the broad possibilities of administration justifies the recent popularity of the microemulsions. Notwithstanding, both vector types still require further developments to overcome some critical limitations related with toxicity and costs, among others. Such developments may include the search for other system components, as the microbial surfactants, that can display improved features.The author acknowledges the financial support from the Strategic Project PEst-OE/EQB/LA0023/2013 and project ref. RECI/BBB-EBI/0179/2012 (project number FCOMP-01-0124-FEDER-027462) funded by Fundacao para a Ciencia e a Tecnologia

Reproductive health and lifestyle factors associated with health-related quality of life among perinatally HIV-infected adolescents in Uganda

Background With increased survival of perinatally HIV - infected adolescents due to antiretroviral therapy (ART), the focus of HIV care has shifted to health-related quality of life (HRQoL) as a measure of disease progression, effects of ART co-morbidity and prognosis. We assessed factors associated with better HRQoL in perinatally HIV -infected adolescents in Uganda by determining the associations between sexual and reproductive health (SRH) or lifestyle experiences on HRQoL. Methods In a cross-sectional study, data on SRH, lifestyle experiences, socio demographic factors, communication with parents on sexuality and satisfaction of SRH services in ART clinics were collected from 614 HIV perinatally infected adolescents aged 10–19 using an interviewer-administered survey questionnaire. HRQoL data were collected using the Medical Outcomes Study HIV Health Survey instrument (MOS-HIV). Factors associated with better HRQoL were analysed using multiple logistic regression. Results The mean age was 16.2 ± 2.1 years, 362 (58.8 %) were females and 210 (34.2 %) were sexually active. Adolescents on ART were twice likely to present with better physical health (AOR = 2.07, 95 % CI: 1.24–3.46) and four times more likely to present with better mental health (AOR = 3.9, 95 % CI: 2.22–6.92) than those who were not on ART. There were no statistically significant associations between SRH (ever had sex, ever been pregnant, condom use, contraceptive use) or life style factors and physical health or mental health. Those with secondary or tertiary education were more likely to present with a better mental health (AOR = 5.3, 95 % CI: 1.86–15.41) compared those who had attained primary or no education. Participants who desired to have a child in future more likely (AOR 1.7, 95 % CI: 1.05–3.00) to present with a better mental health. Lack of communication with guardians on sexuality (AOR = 0.6, 95 % CI: 0.40–0.89), or dissatisfaction with SRH services (AOR 0.34, 95 % CI: 0.18–0.62) were associated with poorer mental health. Conclusion Among perinatally HIV-infected adolescents in Uganda, being on ART was associated with better physical and mental health while lack of communication with guardians on sexuality or dissatisfaction with SRH services was associated with poor mental health. Adolescents with pregnancy intentions were more likely to have a better mental health

Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio as Biomarkers for Risk Stratification and Predictors of 90-day Mortality in Acute Pulmonary Embolism

Background: Acute Pulmonary Embolism (APE) is a critical cardiovascular emergency requiring timely risk stratification. Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) are emerging inflammatory biomarkers that may enhance existing risk models, such as the European Society of Cardiology (ESC) guidelines.Objectives: To assess the prognostic value of NLR and PLR in predicting 90-day mortality in APE patients and their potential role in improving ESC risk stratification.Methods: A retrospective cohort study of 42 APE patients at Chettinad Hospital (2021-2024) was conducted. Clinical, laboratory, and radiological data were analyzed. Statistical tests, including logistic regression, were used to evaluate associations between NLR, PLR, and 90-day mortality.Results: The study included 42 patients (57.1% male, mean age 54.19 ± 15.98 years). Dyspnea (85.7%) and palpitations (54.8%) were the most common symptoms. Elevated NLR and PLR were significantly associated with higher mortality risk. Malignancy (p < 0.001) and right ventricular dysfunction (p < 0.001) were independent mortality predictors. Integrating NLR and PLR into the ESC model improved predictive accuracy with AUC of 0.848 as compared to only ESC stratification with AUC of 0.771.Conclusion: NLR and PLR are valuable biomarkers for APE risk stratification and mortality prediction. Their inclusion in ESC guidelines may refine prognostication, facilitating timely interventions. Prospective multicenter studies are needed for validation

High-Yield Deterministic Focused Ion Beam Implantation of Quantum Defects Enabled by In Situ Photoluminescence Feedback

Focused ion beam implantation is ideally suited for placing defect centers in wide bandgap semiconductors with nanometer spatial resolution. However, the fact that only a few percent of implanted defects can be activated to become efficient single photon emitters prevents this powerful capability to reach its full potential in photonic/electronic integration of quantum defects. Here an industry adaptive scalable technique is demonstrated to deterministically create single defects in commercial grade silicon carbide by performing repeated low ion number implantation and in situ photoluminescence evaluation after each round of implantation. An array of 9 single defects in 13 targeted locations is successfully created-a ≈70% yield which is more than an order of magnitude higher than achieved in a typical single pass ion implantation. The remaining emitters exhibit non-classical photon emission statistics corresponding to the existence of at most two emitters. This approach can be further integrated with other advanced techniques such as in situ annealing and cryogenic operations to extend to other material platforms for various quantum information technologies