A simplified approach to the analysis of subclasses of phospholipids: Application to human platelets

A procedure for the determination of the proportions of diacyl, alkenylacyl and alkylacyl subclasses of glycerolphospholipids was developed. The procedure involves: (1) acid methanolysis of the phospholipid followed by Bligh/Dyer extraction of fatty acid methyl esters (FAME) derived from acyl chain types, dimethylacetals (DMA) derived from alkenyl ether chain types, and lysoalkyl phosphatidic acids (lysoalkyl-PA) derived from alkyl ether chain types; and (2) subsequent acetolysis to convert the lysoalkyl-PA to monoalkyl glycerol diacetates (MAGD). GLC analysis and quantitation (using internal standard, 21∶0 FAME) of FAME, DMA and MAGD allowed calculation of the proportions of the three molecular subclasses. The methanolysis/acetolysis procedure gave an overall mean phospholipid recovery of 95±3%. Analysis of the major phospholipids in four separate preparations of fresh resting human platelets by this procedure showed the following range of molecular subclasses: phosphatidylcholine (PC), 86–92 mol % diacyl, 6–10 mol % alkylacyl and 2–3 mol % diacyl, 5–8 mol % alkylacyl and 34–55 mol % alkenylacyl. The results of these subclass analyses were in general agreement with those reported in the literature.     

Field-effect transistors based on self-organized molecular nanostripes

Charge transport properties in organic semiconductors depend strongly on molecular order. Here we demonstrate field-effect transistors where drain current flows through a precisely defined array of nanostripes made of crystalline and highly ordered molecules. The molecular stripes are fabricated across the channel of the transistor by a stamp-assisted deposition of the molecular semiconductors from a solution. As the solvent evaporates, the capillary forces drive the solution to form menisci under the stamp protrusions. The solute precipitates only in the regions where the solution is confined by the menisci once the critical concentration is reached and self-organizes into molecularly ordered stripes 100-200 nm wide and a few monolayers high. The charge mobility measured along the stripes is 2 orders of magnitude larger than the values measured for spin-coated thin films.     

Hypocholesterolemic effect induced in rats by oil-sardine (Sardinella longiceps) fish and sardine oils having different degrees of unsaturation

Oil-sardine (Sardinella longiceps) fish and its oil were found to have pronounced hypocholesterolemic effect in cholesterol bile salt stressed rats. Effect of fish was more than that observed with its oil. “Stearin” free or solvent winterized sardine oil with more unsaturation showed better effect than sardine oil as such. A significant correlation was observed between iodine value, ratio of polyunsaturated to saturated fatty acids and (2S-P) value of dietary fats, and logarithm of therminal serum total cholesterol (TC). Similarly a correlation between square root of iodine value and terminal serum TC was also observed. However, cholesterol lowering effect was not predictable on the basis of linoleic, arachidonic eicosapentaenoic, and docosahexaenoic acid contents.     

A study of the effects metal residues in poly(9,9-dioctylfluorene) have on field-effect transistor device characteristics

The amount of metal residues from organometallic reagents used in preparation of poly(9,9-dioctylfluorene) by palladium catalysed Suzuki and nickel-induced Yamamoto polycondensations have been determined, and their effect upon the behaviour of the polymer in field-effect transistors (FETs) has been measured. The metal levels from material polymerised by Suzuki method were found to be much higher than from that made by the Yamamoto procedure. Simple treatment of the polymers with suitable metal trapping reagents lowered the metal levels significantly, with EDTA giving best results for nickel and triphenylphosphine for palladium. Comparison of the behaviour of FETs using polyfluorenes with varying levels of metal contamination, showed that the metal residues have little effect upon the mobility values, but often affect the degree of hysteresis, possibly acting as charge traps. Satisfactory device performances were obtained from polymer with palladium levels of 2000 μg/g suggesting that complete removal of metal residues may not be necessary for satisfactory device performance.     

Highly Efficient Microscopic Charge Transport within Crystalline Domains in a Furan‐Flanked Diketopyrrolopyrrole‐Based Conjugated Copolymer

Elucidating the interrelation between the molecular structure and charge transport properties in conjugated polymer thin films is an essential issue in developing the design principle of high‐performance polymer materials for application in organic electronics. In particular, the backbone planarity is suggested to be a key element that governs the transport performance, especially in recently developed donor–acceptor (D–A)‐type copolymers exhibiting high mobility, whereas the direct evaluation of the intrinsic transport performance, usually realized only within the small crystalline domains, is difficult by using conventional macroscopic measurements. Here, it is demonstrated that a D–A type copolymer, PDPPF‐DTT, which consists of furan‐flanked diketopyrrolopyrrole (DPP) and dithienothiophene (DTT) units in the conjugated backbone, exhibits a highly efficient charge transport performance within the crystalline domains with a remarkably low activation energy of less than 8 meV, based on microscopic measurements using field‐induced electron spin resonance spectroscopy. This high transport performance is primarily caused by the high backbone planarity realized by introducing furan‐flanked DPP and fused dithienothiophene units, which is demonstrated from the density functional theory calculations. This result provides a microscopic indication of the effectiveness of the present molecular design to produce a planar backbone and realize highly efficient charge transport performance.     

Intelligent parameter identification of machining Ti64 alloy

In this paper, a methodology approach based on analysis of multidimensional Pareto front is proposed. A new optimization approach helps the user to set the optimal parameters of a machining process. Four neural networks are used to model desire output responses, and they are used as objective functions. Particle swarm optimization (PSO) is used to find the best parameters that improve process. As application of approached proposed, an analysis of a multidimensional Pareto front is made considering a minimization of time, temperature, vibration, and surface roughness in a milling process of Ti64 alloy. Physical parameters for experimental approach are tool diameter, number of cutting edge of the tool, cutting speed, feed, and depth of cut. Analysing the 2D and 3D multidimensional Pareto front is generated a user table of machining parameters.     

Cluster-based centralized data fusion for tracking maneuvering targets using interacting multiple model algorithm

The interacting multiple model (IMM) algorithm has proved to be useful in tracking maneuvering targets. Tracking accuracy can be further improved using data fusion. Tracking of multiple targets using multiple sensors and fusing them at a central site using centralized architecture involves communication of large volumes of measurements to a common site. This results in heavy processing requirement at the central site. Moreover, track updates have to be obtained in the fusion centre before the next measurement arrives. For solving this computational complexity, a cluster-based parallel processing solution is presented in this paper. In this scheme, measurements are sent to the data fusion centre where the measurements are partitioned and given to the slave processors in the cluster. The slave processors use the IMM algorithm to get accurate updates of the tracks. The master processor collects the updated tracks and performs data fusion using ‘weight decision approach’. The improvement in the computation time using clusters in the data fusion centre is presented in this paper     

Application of Electron Energy Loss Spectroscopy and Energy Filtering Transmission Electron Microscopy for Microchemical Studies in 2.25Cr-1Mo Steel

Electron enregy loss spectroscopy (EELS) and energy filtering transmission electron microscopy (EFTEM) investigation on 2.25Cr-lMo steel was carried out to understand the nature of evolution of secondary carbides. The filtered images obtained from two different ageing treatments indicate that the steel evolves to a more stable carbide namely M23C6 in comparison to M2C. Microchemical information was generated from EELS spectra. Suitable choice for estimating the microchemical state was discussed. To evaluate the behaviour of ageing an elemental ratio of Fe to Cr is employed.     

An Analytical Study on global radiation and meteorological parameters for India

ABSTRACT

A study is carried out for global radiation (global horizontal and global tilted radiation) and meteorological parameters (humidity and temperature) recorded for a period of one year (2011) at the National Institute of Solar Energy (NISE), Gwal Pahri (28.42°N, 77.15°E), India. Maximum global horizontal radiation of 7.22?kWh/m² is recorded in the month of June while minimum of 0.91?kWh/m² is observed in February. The highest value of the tilted radiation 7.27?kWh/m² is recorded in March and the lowest value 0.90?kWh/m² is noticed in February. The maximum temperature of 36.5°C and humidity of 87.6% are observed in the months of June and July, respectively. Conversely, minimum temperature of 6.1°C and humidity 21.7% are noticed in the months of January and April, respectively. Furthermore, meteorological parameters have been correlated with global radiation on horizontal and tilted surface. The study is vital for the performance analysis of different solar energy applications.