Chromatographic estimation of maturity based phytochemical profiling of Ipomoea mauritiana

Collection of herbs at right maturity is one of such parameter which affect afficacy of medicinal plants. Standard reference markers used in quality control of herbal drugs mostly authenticate identity and not efficacy. In order to derive bioactive markers, knowledge regarding appropriate collection time for each herb is essential. Traditional medical knowledge is bioactivity-oriented and informs about best time of collection for certain medicinal species, as observed in case of Ipomoea mauritiana Jacq. (Vidari–Sanskrit). Only mature (bigger size) tubers of Ipomoea mauritiana are used by Traditional Medical Practitioners (TMP) for preparing galactagogues and immunomodulatory herbal medicines (Rasayan).Microscopy of transverse sections revealed structural variation between mature and immature tubers and girth of tubers determine the maturity of plant, the difference in phytochemical profiles of mature and immature tubers was observed.Variation in phytoconstituents of mature and immature tubers was confirmed through proximate analysis, phytochemical screening, qualitative HPLC and HPTLC analysis revealed the variation in phytoconstituents in mature and immature tubers.Keywords: Microscopy, HPLC, HPTLC, proximate analysis, phytochemical screening

Chromatographic estimation of maturity based phytochemical profiling of Ipomoea mauritiana

Collection of herbs at right maturity is one of such parameter which affect afficacy of medicinal plants. Standard reference markers used in quality control of herbal drugs mostly authenticate identity and not efficacy. In order to derive bioactive markers, knowledge regarding appropriate collection time for each herb is essential. Traditional medical knowledge is bioactivity-oriented and informs about best time of collection for certain medicinal species, as observed in case of Ipomoea mauritiana Jacq. (Vidari–Sanskrit). Only mature (bigger size) tubers of Ipomoea mauritiana are used by Traditional Medical Practitioners (TMP) for preparing galactagogues and immunomodulatory herbal medicines (Rasayan).Microscopy of transverse sections revealed structural variation between mature and immature tubers and girth of tubers determine the maturity of plant, the difference in phytochemical profiles of mature and immature tubers was observed.Variation in phytoconstituents of mature and immature tubers was confirmed through proximate analysis, phytochemical screening, qualitative HPLC and HPTLC analysis revealed the variation in phytoconstituents in mature and immature tubers.Keywords: Microscopy, HPLC, HPTLC, proximate analysis, phytochemical screening

Investigation of the Performance Parameters of an Experimental Plate Heat Exchanger in Single Phase Flow

Abstract Experiments were conducted to determine the heat transfer characteristics for fully developed flow of air and water flowing in alternate corrugated ducts. The test section was formed by three identical corrugated channels having corrugation angle of 30 o with cold air flowing in the middle one and hot water equally divided in the adjacent channels. Sinusoidal wavy arcs connected with tangential flat portions make the said corrugation angle with transverse direction. The Reynolds number based on hydraulic diameter varied from 750 to 3200 for water and from 566 to 2265 for air by changing the mass flow rate of the two fluids. The Prandtl numbers were approximately constant at 2.55 for water and 0.7 for air. The various correlations obtained are Nu m =0.247Re 0.83 and Nu m =0.409Re 0.57 for water and air, respectively and f = 2.014Re -0.12 for air channel

Latent class analysis variable selection

We propose a method for selecting variables in latent class analysis, which is the most common model-based clustering method for discrete data. The method assesses a variable's usefulness for clustering by comparing two models, given the clustering variables already selected. In one model the variable contributes information about cluster allocation beyond that contained in the already selected variables, and in the other model it does not. A headlong search algorithm is used to explore the model space and select clustering variables. In simulated datasets we found that the method selected the correct clustering variables, and also led to improvements in classification performance and in accuracy of the choice of the number of classes. In two real datasets, our method discovered the same group structure with fewer variables. In a dataset from the International HapMap Project consisting of 639 single nucleotide polymorphisms (SNPs) from 210 members of different groups, our method discovered the same group structure with a much smaller number of SNP

Standardisation of magnetic nanoparticles in liquid suspension

Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation, spanning a large number of industry sectors from imaging and actuation based applications in biomedicine and biotechnology, through large-scale environmental remediation uses such as water purification, to engineering-based applications such as position-controlled lubricants and soaps. Continuous advances in their manufacture have produced an ever-growing range of products, each with their own unique properties. At the same time, the characterisation of magnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpret the measurement data. In many cases, the stringent requirements of the end-user technologies dictate that magnetic nanoparticle products should be clearly defined, well characterised, consistent and safe; or to put it another way—standardised. The aims of this document are to outline the concepts and terminology necessary for discussion of magnetic nanoparticles, to examine the current state-of-the-art in characterisation methods necessary for the most prominent applications of magnetic nanoparticle suspensions, to suggest a possible structure for the future development of standardisation within the field, and to identify areas and topics which deserve to be the focus of future work items. We discuss potential roadmaps for the future standardisation of this developing industry, and the likely challenges to be encountered along the way

Energy and Electron Transfer Dynamics within a Series of Perylene Diimide/Cyclophane Systems.

Artificial photosynthetic systems for solar energy conversion exploit both covalent and supramolecular chemistry to produce favorable arrangements of light-harvesting and redox-active chromophores in space. An understanding of the interplay between key processes for photosynthesis, namely light-harvesting, energy transfer, and photoinduced charge separation and the design of novel, self-assembling components capable of these processes are imperative for the realization of multifunctional integrated systems. We report our investigations on the potential of extended tetracationic cyclophane/perylene diimide systems as components for artificial photosynthetic applications. We show how the selection of appropriate heterocycles, as extending units, allows for tuning of the electron accumulation and photophysical properties of the extended tetracationic cyclophanes. Spectroscopic techniques confirm energy transfer between the extended tetracationic cyclophanes and perylene diimide is ultrafast and quantitative, while the heterocycle specifically influences the energy transfer related parameters and the acceptor excited state.S.T.J.R. thanks the Cambridge Home and European Scholarship Scheme and the Robert Gardiner memorial scholarship. S.T.J.R., A.F. and O.A.S. thank the ERC starting investigator grant ASPiRe (project no. 240629) and the EPSRC (reference no. EP/G060649/1). Femtosecond and nanosecond spectroscopy (R.M.Y.), EPR spectroscopy (M.D.K.) and phosphorescence spectroscopy (Y.W.) were supported as part of the ANSER Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under award no. DE-SC0001059. J.F.S., J.J.H., N.H., N.A.V. and E.D.J. acknowledge the Joint Center of Excellence in Integrated Nano-Systems (JCIN) between KACST and Northwestern University (Project 34-946) for their continued financial support. E.J.D. acknowledges NSF and Ryan fellowships. A.H. and W.M.N. thank the COST Action CM1005 “Supramolecular Chemistry in Water” and the DFG (grant NA-686/5) for financial support.This is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/jacs.5b1032

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown

Validation of a small-animal PET simulation using GAMOS: a Geant4-based framework

onte Carlo-based modelling is a powerful tool to help in the design and optimization of positron emission tomography (PET) systems. The performance of these systems depends on several parameters, such as detector physical characteristics, shielding or electronics, whose effects can be studied on the basis of realistic simulated data. The aim of this paper is to validate a comprehensive study of the Raytest ClearPET small-animal PET scanner using a new Monte Carlo simulation platform which has been developed at CIEMAT (Madrid, Spain), called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations). This toolkit, based on the GEANT4 code, was originally designed to cover multiple applications in the field of medical physics from radiotherapy to nuclear medicine, but has since been applied by some of its users in other fields of physics, such as neutron shielding, space physics, high energy physics, etc. Our simulation model includes the relevant characteristics of the ClearPET system, namely, the double layer of scintillator crystals in phoswich configuration, the rotating gantry, the presence of intrinsic radioactivity in the crystals or the storage of single events for an off-line coincidence sorting. Simulated results are contrasted with experimental acquisitions including studies of spatial resolution, sensitivity, scatter fraction and count rates in accordance with the National Electrical Manufacturers Association (NEMA) NU 4-2008 protocol. Spatial resolution results showed a discrepancy between simulated and measured values equal to 8.4% (with a maximum FWHM difference over all measurement directions of 0.5 mm). Sensitivity results differ less than 1% for a 250–750 keV energy window. Simulated and measured count rates agree well within a wide range of activities, including under electronic saturation of the system (the measured peak of total coincidences, for the mouse-sized phantom, was 250.8 kcps reached at 0.95 MBq mL−1 and the simulated peak was 247.1 kcps at 0.87 MBq mL−1). Agreement better than 3% was obtained in the scatter fraction comparison study. We also measured and simulated a mini-Derenzo phantom obtaining images with similar quality using iterative reconstruction methods. We concluded that the overall performance of the simulation showed good agreement with the measured results and validates the GAMOS package for PET applications. Furthermore, its ease of use and flexibility recommends it as an excellent tool to optimize design features or image reconstruction techniques