EMAT Based Ultrasonic System for Determination of Thickness Variation in Metallic Samples

Thickness measurement is an important primary measurement parameter. It itself and from the various derived para-meters, provides valuable information in testing and process industries. Although numerous techniques are avail-able for thickness measurement which provide very good results for transparent material and when both sides are accessible, but these methods have limitations in case of opaque material and when only one side is accessible. A new EMAT based non contact technique is reported in this paper which is capable of measuring thickness variation even in opaque material and if only one side is accessible. Using EMAT it was possible to measure the thickness of a material in the order of a few nanometers. This was achi-evable by the facility developed at NPL, India to measure ultrasonic Time of Flight (TOF) to an accuracy of nano-seconds with deviation of 300 picoseconds. An experiment was done using EMAT to measure the variation in thickness due to stamped notch in an aluminium block having thick-ness of 25mm. EMAT system was able to measure considerable variation in the thickness due to notch. An experiment was also done on circular metallic pipe to determine the variation in inner diameter by measuring wall thickness. Excellent result was obtained with greater precision. This better precision is achieved because of Beam Width to Reflector ratio being close to unity. In case of flat plates this ratio is much greater than unity. To reduce this ratio to unity even in case of flat plates several samples were used in conjunction with EMAT and experiments were again performed on the above mentioned aluminium block to determine the variation in thickness due to notch

Nations within a nation: variations in epidemiological transition across the states of India, 1990–2016 in the Global Burden of Disease Study

18% of the world's population lives in India, and many states of India have populations similar to those of large countries. Action to effectively improve population health in India requires availability of reliable and comprehensive state-level estimates of disease burden and risk factors over time. Such comprehensive estimates have not been available so far for all major diseases and risk factors. Thus, we aimed to estimate the disease burden and risk factors in every state of India as part of the Global Burden of Disease (GBD) Study 2016

<i style="mso-bidi-font-style:normal"><span style="font-size:11.0pt;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:Mangal; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB">Panchagavya Ghrita</span></i><span style="font-size:11.0pt;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:Mangal; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB">, an Ayurvedic formulation attenuates seizures, cognitive impairment and oxidative stress in pentylenetetrazole induced seizures in rats</span>

446-451Panchagavya Ghrita (PG), according to Ayurvedic formulary of India (AFI), is used to treat epilepsy (apasmara), fever (<i style="mso-bidi-font-style: normal">jvara), mania (unmade) and jaundice (kamala). In the present study, we examined its effect on convulsions, oxidative stress and cognitive impairment in pentylenetetrazole (PTZ) induced seizures in rats. PG @ 250, 500, 1000, 2000 and 4000 mg/kg was administered orally for 7 days to male Wistar rats. On day 7, PTZ (60 mg/kg) was injected intraperitoneally 2 h after the last dose of PG. Sodium valproate (300 mg/kg) was used as positive control. Latency to myoclonic jerks, clonus and generalized tonic clonic seizures (GTCS) were recorded for seizure severity. Cognitive impairment was assessed using elevated plus maze and passive avoidance tests. Malondialdehyde and reduced glutathione levels were measured in rat brain. The results have shown that pretreatment with PG @ 500, 1000, 2000 and 4000 mg/kg exhibited 16.6, 33.3, 50 and 100% protection against occurrence of GTCS. The pretreatment with PG has significantly improved cognitive functions and the oxidative stress induced by seizures demonstrating its protective effect against PTZ induced seizures, and further, use of PG as an anticonvulsant in Ayurvedic system of medicine.</span

Rapamycin protects against middle cerebral artery occlusion induced focal cerebral ischemia in rats

Stroke is a major cause of mortality and disability. The management with thrombolytic therapy has to be initiated within 3-4 h and is associated with limitations like increased risk of intracranial hemorrhage and progression of cerebral injury. Immunophilin inhibitors such as cyclosporine A and tacrolimus have been shown to afford neuroprotection by improving neurological functions and infarct volume in models of ischemic stroke. In the present study, the effect of rapamycin in middle cerebral artery occlusion (MCAo) model of ischemic stroke was evaluated. Ischemic stroke was induced in rats by occluding the MCA using the intraluminal thread. After 1 h of MCAo, animals were administered rapamycin (50, 150, 250 μg/kg, i.p.). After 2 h of occlusion, reperfusion was done. Thirty minutes after reperfusion, animals were subjected to diffusion-weighted magnetic resonance imaging for assessment of protective effect of rapamycin. Twenty-four hours after MCAo, motor performance was assessed, the animals were euthanized and the brains were removed for estimation of malondialdehyde, glutathione, nitric oxide and myeloperoxidase. Significant improvement was observed with rapamycin 150 and 250 μg/kg in percent infarct area, apparent diffusion coefficient and signal intensity as compared to vehicle treated group. Rapamycin treatment ameliorated motor impairment associated with MCAo and significantly reversed the changes in levels of malondialdehyde, glutathione, nitric oxide and myeloperoxidase. The results of the present study indicate neuroprotective effect of rapamycin in MCAo model of stroke. Therefore, rapamycin might be considered as a therapeutic strategy for stroke management

Primary measurement of total ultrasonic power with improved accuracy in rf voltage measurement

Out of the various existing ultrasonic power measurement techniques, the radiation force balance method using microbalance is most widely used in low power (below 1 W) regime. The major source of uncertainty associated with this technique is the error in ac voltage measurement applied to the transducer for the generation of ultrasonic waves. The sources that deteriorate the ac voltage measurement accuracy include cable length and impedance mismatch. We introduce a new differential peak to peak measurement approach to reduce the ac voltage measurement error. The method holds the average peak amplitude of each polarity. Ultralow offset difference amplifier is used to measure peak to peak voltage. The method is insensitive to the variations in the dc offset of the source. The functionality of this method has been tested and compared with the conventional rf voltage measurement method. The output of this proposed technique is dc, which can be measured with an error of less than 0.1%