Frequency shift keying in vortex-based spin torque oscillators

Vortex-based spin-torque oscillators can be made from extended spin valves connected to an electrical nanocontact. We study the implementation of frequency shift keying modulation in these oscillators. Upon a square modulation of the current in the 10 MHz range, the vortex frequency follows the current command, with easy identification of the two swapping frequencies in the spectral measurements. The frequency distribution of the output power can be accounted for by convolution transformations of the dc current vortex waveform, and the current modulation. Modeling indicates that the frequency transitions are phase coherent and last less than 25 ns. Complementing the multi-octave tunability and first-class agility, the capability of frequency shift keying modulation is an additional milestone for the implementation of vortex-based oscillators in RF circuit.Comment: 6 pages, 5 figure

Pengaruh Konsentrasi Katalis dan Reusability Katalis pada Sintesis Triasetin dengan Katalisator Lewatit

Triacetin is a product from reaction between glycerol and acetic acid on acid catalyst. The use of solid catalysts such as ion exchange Lewatit is an alternative method to ease product separation. Synthesize of triacetin was conducted in a batch reactor with stirring speed of 175 rpm, at temperarture of 100oC and the reactant ratio of 6 mole acetic acid / glycerol. The effect of concentration catalyst and reusability of catalyst were investigated. The highest conversion obtained for 84,84 % in catalyst concentration 5% to weight of glycerol. The result showed that comparison of catalyst concentration give real effect to the conversion of glycerol into triacetin, while the reusability catalyst does not give a significant effect on glycerol conversion be triacetin

Faktor-faktor Yang Berhubungan Dengan Pengetahuan Perawat Dalam Menghadapi Cardiac Arrest Di Rsup Prof R. D. Kandou Manado

: Nurses are the front line of health service. Nurses are required to always be ready in every condition they will encounter; one of them is cardiac arrest patients. Cardiac arrest is a condition that could occur suddenly and need to be handled immediately and properly. Knowledge about cardiac arrest could be used in the future when nurses are handling the patients. The objective of this research is to understand the correlation between factors that related with the knowledge of nurses on handling cardiac arrest patients. The samples that we used are 49 nurses that obtained by using purposive sampling techniques. The method of this research is analytical descriptive with cross sectional approach, and the data were collected from respondents by using questionnaires. The result of this study shows no correlation between education and training with the knowledge of nurses. There was a significant correlation with p = 0.001 (<α 0.05) between experience and knowledge of nurses on handling cardiac arrest patients. Conclusions: There is no correlation between education and training with the knowledge of nurses, while there is a correlation between experience and knowledge of nurses

Effect of cuscuta reflexa stem and calotropis procera leaf extracts on glucose tolerance in glucose-induced hyperglycemic rats and mice

Cuscuta reflexa (whole plant) and Calotropis procera (leaves) are used in folk medicine of Bangladesh to control blood sugar in patients suffering from diabetes mellitus. The hypoglycemic effects of methanol and chloroform extracts of whole plants of Cuscuta reflexa, and methanol extract of leaves of Calotropis procera were investigated in oral glucose tolerance tests in Long Evans rats and Swiss albino mice, respectively. Both methanol and chloroform extracts of Cuscuta reflexa whole plant demonstrated significant oral hypoglycemic activity in glucose-loaded rats at doses of 50, 100 and 200 mg/kg body weight. The methanol extract of leaves of Calotropis procera, when tested at doses of 100 and 250 mg/kg body weight did not demonstrate any oral hypoglycemic effect when tested in glucose-loaded mice.Key words: Cuscuta reflexa, Calotropis procera, hypoglycemic activity, oral glucose tolerance test

EFFECT OF CUSCUTA REFLEXA STEM AND CALOTROPIS PROCERA LEAF EXTRACTS ON GLUCOSE TOLERANCE IN GLUCOSE-INDUCED HYPERGLYCEMIC RATS AND MICE

Cuscuta reflexa (whole plant) and Calotropis procera (leaves) are used in folk medicine of Bangladesh to control blood sugar in patients suffering from diabetes mellitus. The hypoglycemic effects of methanol and chloroform extracts of whole plants of Cuscuta reflexa, and methanol extract of leaves of Calotropis procera were investigated in oral glucose tolerance tests in Long Evans rats and Swiss albino mice, respectively. Both methanol and chloroform extracts of Cuscuta reflexa whole plant demonstrated significant oral hypoglycemic activity in glucose-loaded rats at doses of 50, 100 and 200 mg/kg body weight. The methanol extract of leaves of Calotropis procera, when tested at doses of 100 and 250 mg/kg body weight did not demonstrate any oral hypoglycemic effect when tested in glucose-loaded mice

Diagnostic Accuracy of Dried Blood Spots Collected on HemaSpot HF Devices Compared to Venous Blood Specimens To Estimate Measles and Rubella Seroprevalence.

Fingerprick blood spotted onto filter paper offers an alternative to venous blood for use in population-based surveillance because it is comparatively inexpensive, acceptable, and easy to manage in the field. Prior studies have shown excellent agreement for immunoglobulin G (IgG) antibody detection from dried blood spots (DBS) and venous blood samples. However, much of this evidence is from high-income settings or laboratories where the samples were unlikely to be exposed to extreme temperatures and humidity, factors known to degrade DBS. We report the diagnostic accuracy of DBS collected using HemaSpot HF devices against venous sera in measuring measles- and rubella-specific IgG antibodies in a household serosurvey conducted in two districts in India. Paired serum and DBS samples collected by fingerprick were collected from women aged 15 to 50 years enrolled in a serosurvey in Palghar District of Maharashtra and Kanpur Nagar District of Uttar Pradesh in India. Specimen quality and volume were assessed in the laboratory. Samples were tested for antimeasles and antirubella IgG antibodies by an enzyme-linked immunosorbent assay (ELISA) (Euroimmun). Sensitivity of antibody detection by DBS was greater than 98%, and specificity was 90% and 98%, for measles and rubella IgG, respectively. Antibody concentrations were strongly correlated between paired specimens with adequate volume (measles R2 = 0.94; rubella R2 = 0.89). Although correlation was poor if DBS specimens had lower volumes, impact on qualitative results was minimal. This study showed DBS collected with HemaSpot HF devices can generate highly accurate results of measles- and rubella-specific IgG compared to sera in community-based surveys when protocols are optimized for DBS specimens. IMPORTANCE Dried blood spot (DBS) collection provides an easy, practical, and acceptable alternative to venous blood collection, especially for community-based studies, provided that results from DBS are accurate. We demonstrated high sensitivity and specificity for measles- and rubella-specific immunoglobulin G (IgG) with DBS collected via HemaSpot HF devices compared to serum samples. This is one of the largest community-based diagnostic accuracy studies of measles and rubella antibody testing with DBS and the first application we are aware of using HemaSpot HF device for measles and rubella serology. Results support the use of DBS in community-based serosurveillance