1,676 research outputs found

    On Gorenstein Surfaces Dominated by P^2

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    In this paper we prove that a normal Gorenstein surface dominated by the projective plane P^2 is isomorphic to a quotient P^2/G, where G is a finite group of automorphisms of P^2 (except possibly for one surface V_8'). We can completely classify all such quotients. Some natural conjectures when the surface is not Gorenstein are also stated.Comment: Nagoya Mathematical Journal, to appea

    Comparative study of oxytocin bolus and oxytocin infusion during caesarean section

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    Background: The incidence of postpartum haemorrhage varies from 2-11%. Postpartum haemorrhage complicates approximately 4% of deliveries in most large obstetric services. Postpartum haemorrhage is the third major cause of maternal mortality next to pregnancy induce hypertension (pre-eclampsia) and infection. Prevention, early recognition and prompt appropriate intervention are keys to minimizing its impact. Conventionally loss of more than 500 ml of blood following vaginal delivery and 1000 ml of blood following caesarean section is defined as postpartum haemorrhage. In this study we compared the efficacy of intravenous oxytocin bolus (2 IU) dose followed by infusion (160 mIU/minute) and only i.v. oxytocin infusion following delivery of fetus in elective and emergency LSCS with regard to uterine tone.Methods: This study was a prospective observational study. 200 low risk patients scheduled to undergo elective and emergency caesarean section under spinal anaesthesia in Department of obstetrics and gynecology, SSMC, Tumkur. Group A included i.v. bolus + i.v. injection, group B: i.v. infusion.Results: There was significant drop in haemoglobin and PCV in both group A and group B. But it was comparable among two groups. At 15th minute MBP was 77.2 mm of Hg and 80.04 mm of Hg in Group B. In group A better uterine tone was achieved earlier compared to group B at 2, 5, 10, 20 minutes.Conclusions: It was concluded from this study that oxytocin i.v. bolus with infusion causes earlier attainment of better uterine tone when compared with only infusion

    Anisotropic angular broadening in the solar wind

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    We present Very Large Array observations at wavelengths of 2, 3.5, 6, and 20 cm, of angular broadening of radio sources due to the solar wind in the region 2-16 solar radii. Angular broadening is anisotropic with axial ratios in the range 2-16. Larger axial ratios are observed preferentially at smaller solar distances. Assuming that anisotropy is due to scattering blobs elongated along magnetic field lines, the distribution of position angles of the elliptically broadened images indicates that the field lines are non-radial even at the largest heliocentric distances observed here. At 5R ⊙, the major axis scattering angle is ~0.7" at λ=6 cm and it varies with heliocentric distance as R -1.6. The level of turbulence, characterized by the wave structure function at a scale of 10 km along the major axis, normalized to λ=20 cm, has a value 20±7 at 5R⊙ and varies with heliocentric distance as R -3. Comprison with earlier results suggest that the level of turbulence is higher during solar maximum. Assuming a power-law spectrum of electron density fluctuations, the fitted spectral exponents have values in the range 2.8-3.4 for scales sizes between 2-35 km. The data suggests temporal fluctuations (of up to 10%) in the spectral exponent on a time scale of a few tens of minutes. The observed structure functions at different solar distances do not show any evidence for an inner scale; the upper limits are 1 km at 2R⊙ and 4 km at 13R ⊙. These upper limits are in conflict with earlier determinations and may suggest a reduced inner scale during solar maximum

    A Comparative study to assess the effectiveness and safety of cilnidipine versus amlodipine in patients with newly diagnosed essential hypertension: insights from a single centre prospective observational study

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    Background: Calcium channel blockers (CCBs) are proposed to play a pivotal role for the management and control of hypertension. Dihydropyridine-type calcium channel blockers (CCBs) like Amlodipine are frequently used because for their strong antihypertensive and minimal adverse side effects. However, it is commonly associated with the causation of pedal edema among the patients. Cilnidipine, which is a novel new generation calcium channel blocker, is presumed to cause lesser pedal edema with a satisfactory clinical control of hypertension along with negligible side effects. This study was carried out to compare clinical effectiveness and safety profile between Amlodipine and Cilnidipine.Methods: A prospective, randomized, open label study of 12 weeks’ duration was conducted amongst 60 patients with newly diagnosed essential hypertension. 30 patients of one group received Tab. Amlodipine 5 mg and 30 patients of same age groups received Tab. Cilnidipine 10mg.Results: There was a highly statistically significant decrease in the level of blood pressure in the Cilnidipine group compared to the Amlodipine group mainly at day 90 (P<0.001). Cilnidipine treated group had a fall in blood pressure of 23 ± 8 mmHg and the Amlodipine group had a decrease in the blood pressure of 12±7mmHg. Additionally, there was also significant reduction in pulse rate in the cilnidipine group. Only 4 patients in the Cilnidipine group developed ankle edema which completely disappeared at the end of 12 weeks of therapy compared to 9 patients in the Amlodipine group which persistently worsened at the completion of the study.Conclusions: Our study concluded that cilnidipine was a well-tolerated anti-hypertensive drug amongst patients with newly diagnosed essential hypertension and associated with minor adverse effects

    A validated RP-HPLC method for simultaneous determination of Hydrochlorothiazide and Losartan Potassium in pharmaceutical formulation

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    A new, simple and sensitive reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed for the separation and quantification of Hydrochlorothiazide (HCTZ) and Losartan Potassium (LOS) in tablet dosage form. The determination was carried out using GRACE C18 [4.6 x 250 mm] column as a stationary phase and mobile phase comprised of Acetonitrile: Phosphate Buffer(50 : 50) pH 3.1 in proportion of 50:50(v/v); the pH of phosphate buffer adjusted to (3.1) using orthophosphoric acid. The flow rate was maintained at 1.0ml/min and the eluent was monitored at 226nm.The retention time of MET and VILD were 4.250 min and 8.300 min respectively. The method was validated in terms of linearity, precision, accuracy, specificity and robustness. The method was linear and for precision studies; RSD for HCTZ and LOS were 0.02 and 0.04 respectively. The percentage recoveries for both drugs from their tablets were 100.80 and 99.76 respectivel

    Electric field enhancement and concomitant Raman spectral effects at the edges of a nanometre-thin gold mesotriangle

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    The local electric field enhancement at various regions of an individual nanometre-thin gold mesotriangle has been demonstrated both numerically and experimentally. This work provides, for the first time, direct experimental evidence of localized enhancement of Raman signals at three edges of nanometre-thin gold mesotriangles at single particle level, using Raman microscopy. Raman images were collected from mesotriangles of ~11 mm edge length and ~30 nm thickness, using adsorbed crystal violet as the probe molecule. Spatial distribution and the extent of electric field enhancement around a single mesotriangle are investigated theoretically by finite-difference time-domain (FDTD) simulations. Confocal Raman studies provided direct proof for the substantial electrical field enhancement at the edges and corners compared to the face of the mesotriangle. The simulated electric field enhancement was in the order, corner > edge > surface, which is in complete agreement with the experimental results

    Matroids and Quantum Secret Sharing Schemes

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    A secret sharing scheme is a cryptographic protocol to distribute a secret state in an encoded form among a group of players such that only authorized subsets of the players can reconstruct the secret. Classically, efficient secret sharing schemes have been shown to be induced by matroids. Furthermore, access structures of such schemes can be characterized by an excluded minor relation. No such relations are known for quantum secret sharing schemes. In this paper we take the first steps toward a matroidal characterization of quantum secret sharing schemes. In addition to providing a new perspective on quantum secret sharing schemes, this characterization has important benefits. While previous work has shown how to construct quantum secret sharing schemes for general access structures, these schemes are not claimed to be efficient. In this context the present results prove to be useful; they enable us to construct efficient quantum secret sharing schemes for many general access structures. More precisely, we show that an identically self-dual matroid that is representable over a finite field induces a pure state quantum secret sharing scheme with information rate one

    Concomitant yield optimization of tannase and gallic acid by Bacillus licheniformis KBR6 through submerged fermentation : an industrial approach

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    The present study is concerned with the evaluation of tannase and gallic acid production effi cacy of Bacillus licheniformis KBR6 under diff erent environmental conditions through submerged fermentation. Results have shown that diff erent environmental conditions and mineral sources have diff erential infl uences on tannase and gallic acid production. Highest tannase and gallic acid yield was observed at incubation period of 18 h and 22 h, respectively. At tannic acid concentration of 15 g/l, maximum cell mass (0.75 g/l), cell yield coeffi cient (0.08 g/g), specifi c growth rate (37.5 mg/g/h), tannase yield (16.3 U/g) and specifi c tannase production rate (0.80 U/g/h) were observed, however, at higher tannic acid concentration a decrease in tannase yield and production rate were observed, but gallic acid production increased with increasing tannic acid concentration. Additional carbohydrate sources like glucose, fructose, and lactose showed positive infl uence on enzyme yield. Among the studied nitrogen sources urea and NH4Cl, and of the phosphate sources KH2PO4 showed favourable eff ects on cell growth and simultaneous enzyme and gallic acid production. Temperature of 35 °C was found to be optimum for tannase and gallic acid production. Of all the studied metal ions Ca2+, Mg2+ and Na+ showed positive eff ect whereas, Co2+, Ag2+, Pb2+, Hg2+ showed inhibitory eff ects
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