117 research outputs found

    Micro-Switch Design and Its Optimization Using Pattern Search Algorithm for Application in Reconfigurable Antenna

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    This chapter reports the design and optimization algorithm of metal-contact RF microswitch. Various important evolutionary optimization techniques that can be used to optimize non-linear and even non-differentiable types of radio frequency (RF) circuit’s problems are also reviewed. The transient response of the proposed switch shows displacement time (i.e., squeezed-film damping effect) of 5.0 μs and pull-in voltage varying from 9.0 to 9.25 V. Primarily, the switch exhibits insertion loss of 0.15 to 0.51 dB in on-position and isolation of 75.96 to 35.83 dB in off-position at 0.1–10 GHz. Also, the proposed RF switch equivalent circuit and layout are validated in ADS software which was earlier simulated in HFSS. A pattern search (PS) algorithm is used to optimize RF characteristics of the proposed switch after a brief review of the different optimization techniques. After optimization, the switch shows decrement in insertion loss and increment in isolation at 0.1–10 GHz. Further, two such optimized switches are introduced on the defected ground structure (DGS) antenna to make it reconfigurable in terms of frequency. Reconfigurable antenna (RA) is simulated using HFSS software and simulation results are verified by showing the mark of agreement with the fabrication results. The novelty in the proposed design is due to dual-band behavior and better resonance performance than antennas available in the literature. Attractions of proposed RA are its miniaturization and its utility in IEEE US S-(2.0–4.0 GHz) and C-(4.0–8.0 GHz) band

    Vascular reactivity of isolated rat mesenteric arterioles in the presence and absence of ouabain

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    The microvasculature plays a significant role in the regulation of blood pressure and regional blood supply. Cardiotonic steroids like the adrenal cortical hormone (ouabain) have been proposed to play a role in some forms of hypertension. The purpose of this study was to determine the effect of different agonists on arteriolar diameter in the presence and absence of ouabain. In Vitro studies on isolated intact rat mesenteric arterioles were performed by administering different concentrations of the vasoconstrictor norepinephrine (NE) and the vasorelaxant acetylcholine (Ach) in the presence and absence of ouabain. NE induced constriction was not significantly enhanced in the presence of ouabain. Ach completely reversed NE-induced constriction without ouabain, which was significantly impaired in ouabain presence (p+Channel blockade almost completely abolished Ach-induced relaxation in presence and absence of ouabain

    PARVIMONAS MICRA AND FUSOBACTERIUM NUCLEATUM SEPTIC ARTHRITIS: A RARE ANAEROBIC DOUBLE TROUBLE

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    Septic arthritis is a condition initiated by pathogenic inoculation of joints either by direct or hematogenous route, necessitating immediate medical attention. Among aerobic bacteria, Staphylococcus aureus and Streptococcus spp. are commonly found in association with septic joints. Anaerobes are very rarely involved in the causation of septic arthritis with an estimated rate of <1%. We are presenting a case of septic arthritis of knee joint by Parvimonas micra and Fusobacterium nucleatum, both being constituents of microbial flora in the oral cavity and gastrointestinal tract. Gram stain and anaerobic culture incorporated along with the aerobic culture of synovial fluid have played an important role in the preliminary diagnosis of anaerobic septic arthritis in this case

    Assessment of selenium levels and risk factors for stroke and other cardiovascular disease: a cross sectional study in a seleniferous area of Punjab, India

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    Background and aims: Rural areas of Punjab in India have been found to have soil rich in selenium (Se); about 2160 hectare area is seleniferous and is populated by about 10,000 inhabitants. Selenium concentrations in these villages were reported to be as high as 65 times over non-seleniferous areas. The aim of this cross-sectional study was to evaluate selenium levels in blood, hair and nails in a group of subjects living in this area, and to evaluate the correlation between selenium exposure levels and a relevant cardiovascular risk factor and blood pressure. Methods: In a random sample of rural residents in three districts of a seleniferous area of Punjab, we determined selenium concentration in hair, nail clippings and serum samples. Analyses were carried out using atomic absorption spectrophotometry at National Dairy Research Institute (NDRI), Karnal, India. Data analysis was performed using the STATA 15.0 software (STATA Corp. TX). Results: A total of 680 human subjects were recruited in this study, with a male/female ratio of 0.65 and a median age of 43 (IQR 32-52). Medium selenium levels in blood, hair and nail were 86.7 µg/l (IQR 55.9-200.3), 20.7 µg/g (IQR 12.6-40.3) and 56.9 µg/g (IQR 42.8-83.9), respectively, with lower levels in women in all three kind of samples. Concerning systolic blood pressure, Pearson’s correlation coefficients were 0.102 (95 % CI -0.025 to 0.226, p=0.116); 0.076 (95% CI -0.010 to 0.160, p=0.085); 0.072 (95% CI -0.015 to 0.157, p=0.104) with blood, hair and nail, respectively. For diastolic blood pressure, Pearson’s correlation coefficients are 0.106 (95% CI -0.022 to 0.230, p=0.104), 0.036 (95% CI -0.050 to 0.122, p=0.409), 0.049 (95% CI -0.038 to 0.135, p=0.272), respectively. Conclusions: Our findings indicate a positive correlation between selenium content in blood, hair and nails and increasing systolic and diastolic pressure levels, in line with previous epidemiologic findings, indicating a possible health concern for this highly exposed population. The possible relation between selenium over-exposure and onset of hypertension and other cardiovascular diseases deserves further investigation

    Sexual dimorphism among medical students of north India assessed by interorbital circumference index

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    Background: The human body dimensions are affected by ecological, geographical, racial, gender, and age factors. Craniofacial anthropometry has become an important tool used in genetic counseling, reconstructive surgery, and forensic medicine. Orbital measurements are important in the evaluation of several systemic syndrome, craniofacial abnormalities, and also surgical treatment of post-traumatic telecanthus. Among these measurements, normal interpupillary distance, inner canthal distance (ICD), and outer intercanthal distance are the vital features to be known. Aims and Objectives: The aims and objectives of the present study were to assess the ICD, head circumference (HC), and circumference orbital index of male and female medical students of North India and find out gender differences in the respective parameters and thus to contribute the present finding to the available literature. Materials and Methods: This was an observational descriptive study conducted in the department of anatomy at a fixed time in 150 MBBS course students in the age group 18–22 years. The ICD and HC were measured using round end digital spreading Vernier caliper. Then, circumference interorbital index (CII) was calculated and analyzed. Results: The mean ICD in males was 3.44±0.33 mm and in females was 3.21±0.32 mm; mean HC in males was 56.03±1.55 mm and in females was 53.88±1.38 mm; and mean CII in males was 6.15±0.54 and in females was 5.95±0.51. Conclusion: The result of this study will help to establish the mean values for of craniofacial anthropometric parameters for medical students of North India, and the results are showing that craniofacial anthropometric parameters are sexually dimorphic

    Potential of Complementary and Alternative Medicine in Preventive Management of Novel H1N1 Flu (Swine Flu) Pandemic: Thwarting Potential Disasters in the Bud

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    The emergence of novel H1N1 has posed a situation that warrants urgent global attention. Though antiviral drugs are available in mainstream medicine for treating symptoms of swine flu, currently there is no preventive medicine available. Even when available, they would be in short supply and ineffective in a pandemic situation, for treating the masses worldwide. Besides the development of drug resistance, emergence of mutant strains of the virus, emergence of a more virulent strain, prohibitive costs of available drugs, time lag between vaccine developments, and mass casualties would pose difficult problems. In view of this, complementary and alternative medicine (CAM) offers a plethora of interesting preventive possibilities in patients. Herbs exhibit a diverse array of biological activities and can be effectively harnessed for managing pandemic flu. Potentially active herbs can serve as effective anti influenza agents. The role of CAM for managing novel H1N1 flu and the mode of action of these botanicals is presented here in an evidence-based approach that can be followed to establish their potential use in the management of influenza pandemics. The complementary and alternative medicine approach deliberated in the paper should also be useful in treating the patients with serious influenza in non pandemic situations

    Global Retinoblastoma Presentation and Analysis by National Income Level.

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    Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
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