Passive Wireless Pressure Gradient Measurement System for Fluid Flow Analysis.

Using distributed MEMS pressure sensors to measure small flow rates in high resistance fluidic channels is fraught with challenges far beyond the performance of the pressure sensing element. In a typical core-flood experiment, which may last several months, flow-induced pressure gradients are generated in porous rock core samples wrapped in a polymer sheath. Measuring these pressure gradients along the flow path requires high resolution pressure measurement while contending with difficult test conditions such as large bias pressures (up to 20 bar) and temperatures (up to 125 °C), as well as the presence of corrosive fluids. This work is directed at a system for using passive wireless inductive-capacitive (LC) pressure sensors that are distributed along the flow path to measure the pressure gradient. The sensors are wirelessly interrogated with readout electronics placed exterior to the polymer sheath for continuous monitoring of experiments. Using microfabricated pressure sensors that are smaller than ø15 × 3.0 mm3, an LC sensor design model for minimizing pressure resolution, accounting for sensor packaging and environmental artifacts is investigated and experimentally validated. A test setup, built to provide fluid-flow pressure differentials to LC sensors with conditions that mimic placement of the sensors within the wall of the sheath, is used to test the system. Experimental results show the microsystem operating over full-scale pressure range of 20,700 mbar and temperatures up to 125 °C, while achieving pressure resolution of <1 mbar, and resolving gradients of 10-30 mL/min, which are typical in core-flood experiments.

Chemical composition and antibacterial activity of essential oil from fruit of Micromelum integerrimum (Buch.-Ham. ex DC.) Wight & Arn. ex M. Roem.

The essential oil extracted from fruit of Micromelum integrrimum were evaluated through gas chromatography and gas chromatography-mass spectroscopy. 52 compounds were identified from the fruit oil representing 99.98% of the oil. The major components of the total fruit oil are monoterpene hydrocarbons (72.23%), oxygenated monoterpenes (14.78%) and sesquiterpene (11.54%) which were predominated by terpinolene (32.21%), α-pinene (17.24%), ß-pinene (17.24%), and camphene (4.05%). Moreover, other components that present in 1.45% were aromatic compounds, fatty acid, etc. The essential oil exhibited broad spectrum antimicrobial activity which is concentration dependent and 100 µL of the fruit oil showed the inhibition zones ranging from 7-16 mm. Fruit oil exhibited strong inhibition activity compared to standard anti-bacterial drug neomycin B (22 mm) against Bacillus subtilis MTCC 441 and Bacillus spizizenii ATCC 6633. This is the first hand report on the chemical profiles and promising anti-microbial activity of Micromelum integrrimum fruit essential oil towards Basillus Sp.

Antimalarial silver and gold nanoparticles: Green synthesis, characterization and in vitro study.

In the present study, we are reporting antimalarial potential of silver (AgNPs) and gold (AuNPs) nanoparticles synthesized by leaf and bark extract of Syzygium jambos (L.) Alston (Myrtaceae). AuNPs and AgNPs obtained by both the extracts were characterized using UV-vis spectroscopy, zeta potential, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier Transform Infrared spectroscopy (FTIR). NMR and FTIR spectra indicate that the saccharides and phenolics present in the S. jambos extracts were the major contributors responsible for the synthesis and stabilization of NPs. NPs were also synthesized by chemical methods and were compared for their antiplasmodial potential against chloroquine sensitive (3D7) and resistant (Dd2) strain of Plasmodium falciparum by using 24h schizont maturation assay. AgNPs synthesized by both the extracts showed higher antiplasmodial activity than the rest. Further, NPs synthesized by S. jambos extracts have shown insignificant cytotoxicity against human cervical cancer cell line (HeLa) and rat skeletal muscle cell line (L6), which proved their biocompatibility.

Marine steroids as potential anticancer drug candidates: In silico investigation in search of inhibitors of Bcl-2 and CDK-4/Cyclin D1.

Star fishes (Asteroidea) are rich in polar steroids with diverse structural characteristics. The structural modifications of star fish steroids occur at 3ß, 4ß, 5α, 6α (or ß), 7α (or ß), 8, 15α (or ß) and 16ß positions of the steroidal nucleus and in the side chain. Widely found polar steroids in starfishes include polyhydroxysteroids, steroidal sulfates, glycosides, steroid oligoglycosides etc. Bioactivity of these steroids is less studied; only a few reports like antibacterial, cytotoxic activity etc. are available. In continuation of our search for bioactive molecules from natural sources, we undertook in silico screening of steroids from star fishes against Bcl-2 and CDK-4/Cyclin D1 - two important targets of progression and proliferation of cancer cells. We have screened 182 natural steroids from star fishes occurring in different parts of the world and their 282 soft-derivatives by in silico methods. Their physico-chemical properties, drug-likeliness, binding potential with the selected targets, ADMET (absorption, distribution, metabolism, toxicity) were predicted. Further, the results were compared with those of existing steroidal and non steroidal drugs and inhibitors of Bcl-2 and CDK-4/Cyclin D1. The results are promising and unveil that some of these steroids can be potent leads for cancer treatments.

Antifungal and antioxidant pyrrole derivative from Piper pedicellatum.

In continuation of our search for efficient pest control natural products from the flora of the South Eastern Sub-Himalayan biodiversity region, we have investigated wild edible Piper pedicellatum C. DC (Piperaceae) from Arunachal Pradesh, India against five important plant pathogenic fungi through an activity guided method, and a new compound, pedicellamide, was isolated. The structure was determined on the basis of extensive spectroscopic studies and confirmed by X-ray crystallography. The compound exhibited antifungal activities against the phytopathogenic fungal organisms Rhizoctonia solani (MIC 38.4 +/- 1.6 microg/mL), Fusarium oxysporum (MIC 29.7 +/- 0.8 microg/mL), Aspergillus niger (MIC 48.6 +/- 0.7 microg/mL), Puccinia gramini (MIC 46.8 +/- 1.4 microg/mL) and Curvularia lunata (MIC 49.1 +/- 0.1 microg/mL). Additionally, the antioxidant potential of the compound was estimated by DPPH, ABTS and FRAP assay and found to be 2.87 +/- 0.20, 2.19 +/- 0.13 and 3.96 +/- 0.17 VCEAC (microM/g), respectively.