In this article a new Transformer and Switched Capacitor-based Boost Converter (T & SC-BC) is proposed for high-voltage/low-current renewable energy applications. The proposed T & SC-BC is an ...original extension for DC-DC boost converter which is designed by utilizing a transformer and switched capacitor (T & SC). Photovoltaic (PV) energy is a fast emergent segment among the renewable energy systems. The proposed T & SC-BC combines the features of the conventional boost converter and T & SC to achieve a high voltage conversion ratio. A Maximum Power Point Tracking (MPPT) controller is compulsory and necessary in a PV system to extract maximum power. Thus, a photovoltaic MPPT control mechanism also articulated for the proposed T & SC-BC. The voltage conversion ratio (Vo/Vin) of proposed converter is (1 + k)/(1 − D) where, k is the turns ratio of the transformer and D is the duty cycle (thus, the converter provides 9.26, 13.88, 50/3 voltage conversion ratios at 78.4 duty cycle with k = 1, 2, 2.6, respectively). The conspicuous features of proposed T & SC-BC are: (i) a high voltage conversion ratio (Vo/Vin); (ii) continuous input current (Iin); (iii) single switch topology; (iv) single input source; (v) low drain to source voltage (VDS) rating of control switch; (vi) a single inductor and a single untapped transformer are used. Moreover, the proposed T & SC-BC topology was compared with recently addressed DC-DC converters in terms of number of components, cost, voltage conversion ratio, ripples, efficiency and power range. Simulation and experimental results are provided which validate the functionality, design and concept of the proposed approach.
Background & objectives: The safety of the ChAdOx1 nCoV-19 vaccine is a cause of concern for many who have been vaccinated. The people have multiple concerns and fear regarding the adverse events of ...the vaccine. Thus, this study was undertaken to establish the safety profile of ChAdOx1 nCoV-19 Corona Virus Vaccine (Recombinant) among the healthcare professionals.
Methods: This was a descriptive cross-sectional survey. After taking clearance from the institutional ethics committee 1500 healthcare professionals, who had their vaccination in the past two weeks were selected. They were provided with an online survey proforma regarding adverse events following immunization (AEFIs) of COVID-19 vaccine developed using google forms with an informed consent form affixed to it.
Results: A total of 1036 individuals participated in the study. The mean and median (inter quartile range) age of the participants was 37.7 ±11.25 and 35 (29-46) yr, respectively. Of these, 52.1 per cent were female, 29.3 per cent were doctors, 33.4 per cent were nurses and 9.5 per cent were paramedical staff. Forty six per cent participants experienced one or more minor AEFIs such as pain, tenderness, redness, etc. at the injection site. Fatigue (31.75%), generalized feeling of unwell (28.57%), muscle pain (23.16%) and fever (21.71%) were the most commonly reported systemic AEFIs followed by headache (20.07%), dizziness (10.03%) and joint pains (15.25%). Most of them experienced these AEFIs within 24 h of the first dose of administration. About 42 per cent of the participants took oral antipyretics/analgesics for managing the AEFIs.
Interpretation & conclusions: ChAdOx1 nCoV-19 Corona Virus Vaccine was found to be associated with mild local and systemic AEFIs that were more common after the first dose as compared to the second dose. There adverse events could be dealt with oral over-the-counter medications, with no requirement of hospitalization.
To evaluate postural fluctuations (PFs) and diurnal variation (DV) of intraocular pressure (IOP) in patients with untreated glaucoma, glaucoma suspects and healthy volunteers, and study their ...relationship, if any, to the extent of glaucomatous damage.
This prospective, observational cross-sectional study was carried out in a tertiary care referral institution. The patient population included five groups of patients comprising the following: 19 with ocular hypertension (OHT), 26 with optic discs suspicious for glaucoma (DS), 18 with normal tension glaucoma (NTG), 19 with primary open angle glaucoma (POAG) and 20 normal subjects. The IOP was measured at four time periods using Perkins tonometer, in sitting and supine positions. The main outcome measures were change in IOP with posture, the DV in both postures and the relationship between PF, DV and the extent of visual field damage.
The supine IOP was significantly higher than the sitting IOP, at all time points of the day, in all groups (p<0.001). The PF at 04:30 was significantly higher in POAG, OHT and NTG. The PF at 09:00 correlated significantly with the mean deviation (MD) on visual fields in the NTG group (r=0.735; p=0.001). The DV did not correlate with the MD in any of the five groups studied.
The significantly higher supine IOP is frequently missed in routine glaucoma practice. An early morning supine IOP measurement may reveal a peak IOP hitherto not picked up during routine office IOP measurements, and may be a useful measurement in unexplained progressive glaucoma.
Background: Anemia is a common morbidity in elderly persons (aged 60 years or above). In India, in recent years, the number of old age homes (OAHs) and the residents living in them has increased ...significantly. Objective: The aim of this study was to estimate the prevalence of anemia among elderly persons living in OAHs. Methods: This was a cross-sectional study among individuals living in OAH in Delhi, India. Using combination of location and type of OAH, 28 clusters of almost equal sizes were created, of which 13 clusters were randomly selected, and all elderly persons living therein were selected for the study. Sociodemographic profile was recorded using a self-designed, semistructured interview schedule. Hemoglobin (Hb) was estimated using HemoCue Hb 201+ system. Binary Logistic regression was used to assess the socioeconomic determinants of anemia. Results: The study included 334 elderly persons, with a mean (standard deviation SD) age of 75.2 (8.6) years and mean (SD) Hb of 11.6 (1.7) g/dL. The mean (SD) Hb in men was 12.1 (1.7) g/dL compared to 10.9 (1.5) g/dL among women (P < 0.0001). The overall prevalence of anemia was 68.7% (95% confidence interval 63.9, 73.4); among those who were anemic, 47.4% had mild anemia, 47.0% had moderate anemia, and 5.6% had severe anemia. The prevalence of mild anemia was 45% in men compared to 24.8% in women. The odds of anemia among ≥80 years was 2 times that among 60-69 years (P < 0.029). Conclusions: The prevalence of anemia among elderly persons in OAHs is high in Delhi, India and increased with age.
7 Studies have found that spirituality may have a role in improving adherence to medication in the treatment of hypertension, and the role of yoga in reducing systolic and diastolic blood pressure is ...well documented. 12 Considering the positive impact of spiritual well-being in palliative care, the National Institute for Health and Care Excellence recommends it to be included as an integral part of cancer care. ...it is suggested that health care providers must be trained in the assessment of spiritual well-being in a culturally appropriate manner and promote activities such as yoga and meditation to prevent many chronic illnesses.
A corporate feed sequentially rotated 2 × 2 circularly polarized fractal antenna array is investigated in this work. Four number of compact circular fractal antenna elements are positioned ...symmetrically across the geometry. The antenna elements in the subarray are incorporated with 1st order Koch fractal cuts and rotated with respect to its neighbor and the phase change thus generated becomes offset with the phase change in the excitation in the corporate feed. A 2nd order Minkowski fractal curve is implemented on the ground plane to optimize the radiation performance of the array. The proposed fractal antenna array (FAA) is powered with a coaxial feed, with its pin connected to the asymmetric line configuration placed on the top surface. The dimensional confinement of the array is limited to 0.904λ0 × 0.876λ0 × 0.012λ0 (fr = 2.27 GHz) and the overall layout of the geometry is built on a FR4 substrate having a dielectric constant of 4.4. The circularly polarized radiation characteristics of the elements are developed as a result of fractal cuts along the vertical and horizontal sides. A maximum gain response of 5.4 dBic is observed in the impedance band ranging from 2 GHz to 2.5 GHz. The measured results of the proposed array are found to be in good agreement. In quantitative comparison with a few existing arrays with respect to its diverse performance the proposed CP FAA is found to be suitable for space-borne applications operating in the S-band.
Purpose: To evaluate the long-term outcomes of cataract surgery in children with uveitis. Methods: Retrospective, noncomparative review of medical records of children (≤16 years) with uveitic ...cataract who had undergone cataract surgery between January 2001 and December 2014 at a tertiary care center was done. The main outcome measures were visual acuity and postoperative complications. Results: We recruited 37 children (58 eyes) who were diagnosed with uveitic cataract and underwent cataract surgery. The etiology of uveitis included juvenile idiopathic arthritis (n = 19), presumed intraocular tuberculosis (n = 8), idiopathic (n = 4), Behçet's disease (n = 2), Vogt-Koyanagi-Harada syndrome (n = 2), human leukocyte antigen B-27 associated uveitis (n = 1), and toxocariasis (n = 1). Phacoemulsification with intraocular lens (IOL) implantation was performed in 17 patients (27 eyes; 46.55%), while 20 patients (31 eyes; 53.44%) were left aphakic after pars plan lensectomy and vitrectomy. At an average follow-up of 3.69 ± 7.2 (SD) years, all cases had significant improvement in corrected distance visual acuity post cataract extraction; visual acuity of 20/40 or more was achieved in 32 eyes (55.17%). The most common complication was capsular opacification (37.93%). Incidence of secondary procedures as well as glaucoma was not statistically different in patients undergoing IOL implantation from those who were aphakic. Conclusion: Even though number of secondary procedures was more in pseudophakic group, meticulous choice of surgical technique and adequate immunosuppression lead to a modest gain of visual acuity in children undergoing IOL implantation in uveitis. However, scrupulous case selection and aggressive control of pre- and postoperative intraocular inflammation are the key factors in the postoperative success of these patients.
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