685 research outputs found

    Hysteresis in a magnetic bead and its applications

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    We study hysteresis in a micron-sized bead: a non-magnetic matrix embedded with super- paramagnetic nanoparticles. These hold tremendous promise in therapeutic applications as heat generating machines. The theoretical formulation uses a mean-field theory to account for dipolar interactions between the supermoments. The study enables manipulation of heat dissipation by a compatible selection of commercially available beads and the frequency f and amplitude ho of the applied oscillating field in the labortory. We also introduce the possibility of utilizing return point memory for gradual heating of a local region.Comment: 8 pages, 4 figure

    Study of underlying particle spectrum during huge X-ray flare of Mkn 421 in April 2013

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    Context: In April 2013, the nearby (z=0.031) TeV blazar, Mkn 421, showed one of the largest flares in X-rays since the past decade. Aim: To study all multiwavelength data available during MJD 56392 to 56403, with special emphasis on X-ray data, and understand the underlying particle energy distribution. Methods: We study the correlations between the UV and gamma bands with the X-ray band using the z-transformed discrete correlation function. We model the underlying particle spectrum with a single population of electrons emitting synchrotron radiation, and do a statistical fitting of the simultaneous, time-resolved data from the Swift-XRT and the NuSTAR. Results: There was rapid flux variability in the X-ray band, with a minimum doubling timescale of 1.69±0.131.69 \pm 0.13 hrs. There were no corresponding flares in UV and gamma bands. The variability in UV and gamma rays are relatively modest with ∼8% \sim 8 \% and ∼16%\sim 16 \% respectively, and no significant correlation was found with the X-ray light curve. The observed X-ray spectrum shows clear curvature which can be fit by a log parabolic spectral form. This is best explained to originate from a log parabolic electron spectrum. However, a broken power law or a power law with an exponentially falling electron distribution cannot be ruled out either. Moreover, the excellent broadband spectrum from 0.3−790.3-79 keV allows us to make predictions of the UV flux. We find that this prediction is compatible with the observed flux during the low state in X-rays. However, during the X-ray flares, the predicted flux is a factor of 2−502-50 smaller than the observed one. This suggests that the X-ray flares are plausibly caused by a separate population which does not contribute significantly to the radiation at lower energies. Alternatively, the underlying particle spectrum can be much more complex than the ones explored in this work.Comment: 11 pages, 7 figures, Accepted in A&

    Gynecological correlation of thyroid disorders in women

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    Background: Thyroid dysfunctions are a common cause of abnormal uterine bleeding (AUB). They affect menstrual function and reproductive health. The common presenting complaints are weight gain, menstrual irregularities, PCOS, infertility, fatigue, constipation and body aches.In this study we recommended that any woman presenting with undiagnosed fatigue, weight gain, infertility and menstrual disorders should be subjected to Thyroid profile screening. Thus, there is a need to explore this aspect in the earlier stages so as to prevent long term consequences with reproduction and quality of life.Methods: Current study is a retrospective study. The present study was conducted in the department of obstetrics and gynecology, Cama and Albess hospital, Mumbai, Maharashtra, India, from a period of January 2021 to December 2021, 300 women of reproductive age group between menarche to menopause. Quantitative determination of Serum T3, T4 and TSH by CLIA estimated in autoanalyser.Results: The most common age group studied was between 32-40 years. Hyperthyroidism was more common in multipara and hypothyroidism was more common in P2L2. The most common type of menstrual disturbance was menorrhagia. (40.33%) Menorrhagia has been seen to have significant association with thyroid dysfunction. Prevalence of obesity in the study population is 4% and overweight is 23.66%. About 11.33 % of overweight women and 2% of obese women are hypothyroid. 2% of hyperthyroid women are underweight (BMI<18). About 6.33% of women with hypothyroidism had PCOS, most commonly associated with menstrual complaints such as amenorrhoea and oligomenorrhoea. 14% of women with hypothyroidism had clinical findings of anaemia and/or thyromegaly on clinical examination. 14% of women had severe anaemia in the study group, out of which 6.7% of hypothyroid women had severe anaemia. 3.66% women presented with infertility.Conclusions: Biochemical evaluation of thyroid function tests should be compulsory in all patients with menstrual irregularities, PCOS, infertility, fatigue, body aches, anaemia, thyromegaly, weight gain, constipation to detect thyroid dysfunction

    Surgical outcome in germ cell tumor of ovary

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    Background: Ovarian cancer accounts for 225,000 new cases and 140,000 deaths every year. Ovarian germ cell tumors account for 15-20% of all ovarian malignancies and incidence of malignant ovarian germ cell tumors is 2-6%. These tumors typically occur in adolescent girls and young women. Appropriate fertility conserving surgical treatment for patients where fertility needs to be preserved and resection of all visible disease can be successfully performed. For patients with advanced-stage disease, debulking surgery is done.Methods: Current study is a retrospective study. The present study was conducted in the department of obstetrics and gynecology, Cama and Albess hospital, Mumbai, Maharashtra, India, from a period of May 2019 to December 2021. This study was conducted with 30 patients to evaluate the outcome in operated cases of germ cell tumors of ovary.Results: Majority of the patients (30%) were in the age group of 31-40 years, 17 (56.7%) patients were unmarried while 13 (43.3%) patients were married. The most common symptom was abdominal mass and pain (86.7%). The most common histologic type was dysgerminoma (46.7%). Out of total 19 patients with FIGO stage I, 13 patients (68.4%) underwent Fertility sparing surgery (FSS) and 6 patients (31.6%) underwent non fertility sparing surgery (non-FSS).Conclusions: Surgery has an important role in the management of germ cell tumors. Initial careful surgical staging is of great importance for appropriate subsequent therapy. Fertility sparing surgery is feasible in most cases. Malignant ovarian germ cell tumors have excellent prognosis for stage I and for advanced stages

    Radio and infrared study of the star forming region IRAS 20286+4105

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    A multi-wavelength investigation of the star forming complex IRAS 20286+4105, located in the Cygnus-X region, is presented here. Near-infrared K-band data is used to revisit the cluster / stellar group identified in previous studies. The radio continuum observations, at 610 and 1280 MHz show the presence of a HII region possibly powered by a star of spectral type B0 - B0.5. The cometary morphology of the ionized region is explained by invoking the bow-shock model where the likely association with a nearby supernova remnant is also explored. A compact radio knot with non-thermal spectral index is detected towards the centre of the cloud. Mid-infrared data from the Spitzer Legacy Survey of the Cygnus-X region show the presence of six Class I YSOs inside the cloud. Thermal dust emission in this complex is modelled using Herschel far-infrared data to generate dust temperature and column density maps. Herschel images also show the presence of two clumps in this region, the masses of which are estimated to be {\sim} 175 M{\sun} and 30 M{\sun}. The mass-radius relation and the surface density of the clumps do not qualify them as massive star forming sites. An overall picture of a runaway star ionizing the cloud and a triggered population of intermediate-mass, Class I sources located toward the cloud centre emerges from this multiwavelength study. Variation in the dust emissivity spectral index is shown to exist in this region and is seen to have an inverse relation with the dust temperature.Comment: 20 pages, 16 figures, accepted for publication in MNRA

    BLIND DIGITAL WATERMARKING SYSTEM USING 2D-DCT

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    In digital network systems the digital documents can be replicated and pass on effortlessly to extensive individuals with ease and free of cost. Multimedia data like image, video and audio files can be easily downloaded by public and they can easily manipulates. The approved proof as a steady and robust watermark should have been embedded in the digital pictures. The proposed work aims at developing a robust digital watermarking system, it incorporates an effective watermarking algorithm which solves the above problem. New blind frequency watermarking algorithm using 2-Dimensional Discrete Cosine Transform and 1-Dimensional Walsh vectors has been proposed

    In vivo antioxidant and hepatoprotective potential of Glycyrrhiza glabra extract on carbon tetra chloride (CCl4) induced oxidative-stress mediated hepatotoxicity

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    Objective: This study aimed to evaluate the antioxidant and hepatoprotective potential of Glycyrrhiza glabra hydromethanolic root extract against carbon tetra chloride (CCl4) induced oxidative-stress mediated hepatotoxicity in liver tissue of Swiss albino mice.Background: Medicinal plants play a vital role for the development of new drugs. Glycyrrhiza glabra is a widely used medicinal plant. It has many phyto-constituents and active components, which can be used for many diseases.Methods: For the antioxidant and hepatoprotective study, measurement of GSH, CAT, LPO bio-markers in Liver tissue of Swiss albino mice were taken. The animals were divided in six different groups each having 4 mice. The requisite dose of CCl4 was dissolved in appropriate solvent (1.5ml/kg body wt) and administrated as single i.p. dose per mice after 6 hr of last treatment of extract to the animals in each group. Mice were received orally administration of extract up to 7 days. Positive Control group received single i.p. injection of 1.5ml/kg body wt CCl4 in 0.9% saline.Results: The results suggest that, the crude extract of root of G. glabra at the doses of 300 and 600mg/kg body wt. expressed significant hepatoprotective potential against CCl4 induced oxidative stress mediated hepatotoxicity in student ‘t’ test (p<0.05) at dose dependent manner in the Liver tissue of Swiss albino mice. G. glabra root extract alone has not induced hepatotoxicity.Conclusion: Based on this study, It may be concluded that Glycyrrhiza glabra root extract possess hepatoprotective potential in Swiss albino mice.

    Drug utilization pattern of antimicrobials use in upper respiratory tract infection in paediatric patient of rural tertiary care hospital

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    Background: Antimicrobial agents (AMAs) are most commonly prescribed drugs for lower respiratory tract infection (LRTI). This study was conducted to evaluate pattern of prescription and AMAs use in paediatric patient for LRTI in wards of rural tertiary care teaching hospital.Methods: This is prospective, observational study undertaken in paediatric patient in tertiary care hospital. Prescriptions of 60 patient of age group 1-12years diagnosed with LRTI admitted in paediatric ward of rural tertiary care teaching hospital were studied. Positive blood sample were studied for common microorganisms, their sensitivity and resistance to AMAs.Results: Out of 60 patients admitted in paediatric ward of LRTI, 12 patients were of mild to moderate pneumonia, three patients were of bronchiolitis, ten patients were of croups, three patients were of bronchitis and 37 patients were of severe pneumonia. The most frequently prescribed AMAs were combination of cephalosporin and aminoglycosides. The most common organism isolated was streptococcus pneumoniae sensitive to vancomycin in 92.3% and meropenem in 84.6%, resistant to ampicillin, amoxicillin and cloxacillin in 92.3% of cases.Conclusions: The study shows utilisation pattern of AMAs in LRTI, prescribing on which future intervention studies may be based to promote rational drug use
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