890 research outputs found

    3-Acetyl-4-hydroxy­phenyl acrylate

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    In the title compound, C12H12O4, the hydr­oxy O and the C and O atoms of the acetyl group are almost coplanar [maximum deviation = 0.0356 (1) Å] with the benzene ring. The dihedral angle between the benzene ring and the plane through the non-H atoms of the methacrylo­yloxy group is 86.1 (1)°. In the crystal structure, mol­ecules are linked by two C—H⋯O hydrogen bonds, forming dimers with graph-set descriptor R 2 2(16). A strong intra­molecular O—H⋯O hydrogen bond is also observed

    Did human DRD2 haplotypes originate in India? A survey of haplotype frequencies and linkage disequilibrium in the tribes of Eastern Ghats, South India

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    In recent years, a possible role of the dopamine D2 receptor (DRD2) locus has been reported in various fields like the etiology of alcoholism, neuropsychiatric disorders, etc. Therefore, it has been the focus of considerable attention. DNA analysis has made it easier to study haplotypes, arrays of alleles at closely linked loci along the chromosome. These regions are short enough to show little or no recombination, and behave as blocks that might have ancient origins. Scoring these markers as haplotypes, allows analysis both in terms of haplotype frequencies and identity in terms of linkage disequilibrium. The human dopaminergic system is an important focus of study in the fields of neuropsychiatry and pharmacology; it is also a promising nuclear DNA marker in studies of human genome diversity. Haplotype frequencies and linkage disequilibrium for the dopamine D2 receptor gene (DRD2) were determined in 197 unrelated individuals from four tribal populations of the Eastern Ghats, an important region of India. The three marker systems in this study are highly polymorphic in all the four tribal populations and the haplotype system showed high levels of heterozygosity than the Nilgiri Hill tribes and those in other parts of the world, except Africa. Out of the possible eight haplotypes, seven are commonly shared by all the populations. The ancestral allele B2D2Al accounts for 0.028 to 0.166, which was present in all the groups consistently. The linkage disequilibrium was statistically significant in all the populations. The results show a chance of Indian origin or back migration of human DRD2 haplotypes. Data obtained in this study on DRD2 represent one of the small, but growing number of datasets examining disequilibrium and haplotype frequencies in human populations and also indicate that the gene flows from the Eastern Ghats to the Western Ghats. These populations might be one of the oldest among other Indian populations

    SCIENTIFIC EVALUATION OF SIDDHA FORMULATION MUTHUCHIPPI PARPAM-A REVIEW

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    The traditional Siddha system of medicine was made available to common people by saints of south India called as Siddhars. While the timeline of its origin seems to be unpredictable, this ancient medicine interrelates nature and human beings in terms of five basic elements or Pancha bootham viz, earth, water, fire, air and space. Presence of all these five basic elements in the human body and universe in a balanced proportion seem to govern the three vital humours of our body called Vatham, Pitham and Kapham. Any alterations in any of these humours is said to be the cause of Dosham or disease. Hence the Material Medica of this system consists of herbal origin(Mooligai), Mineral origin (Thathu) and animal origin of both land and ocean (Jeevam). According to the Siddha philosophy, these natural resources are the constitutions of these five basic elements and therefore have the ability to prevent and treat the Doshams (diseases) that are caused due to the altered humours. Parpam a potent Siddha formulation with a shelf life of 100 years is usually prepared by grinding mineral or animal sources with herbs followed by a process called Pudam(Incineration). Muthuchippi parpam (Calcinated shell of Pearl oyster) is one such drug of marine origin which has been indicated in the Siddha literature for a wide variety of diseases.This review article analysis the scientific facts behind the traditional use of Muthuchippi parpam

    The Cone Phase of Liquid Crystals: Triangular Lattice of Double-Tilt Cylinders

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    We predict the existence of a new defect-lattice phase near the nematic - smectic-C (NC) transition. This tilt- analogue of the blue phase is a lattice of double-tilt cylinders. We discuss the structure and stability of the cone phase. We suggest that many `nematics' exhibiting short range layering and tilt order may in fact be in the molten cone phase, which is a line liquid.Comment: 4 Pages, 3 Figure

    Fundamental genomic unity of ethnic India is revealed by analysis of mitochondrial DNA

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    Mitochondrial DNA (mtDNA) profiles of 23 ethnic populations of India drawn from diverse cultural, linguistic and geographical backgrounds are presented. There is extensive sharing of a small number of mtDNA haplotypes, reconstructed on the basis of restriction fragment length polymorphisms, among the populations. This indicates that Indian populations were founded by a small number of females, possibly arriving on one of the early waves of out-of-Africa migration of modern humans; ethnic differentiation occurred subsequently through demographic expansions and geographic dispersal. The Asian-specific haplogroup M is in high frequency in most populations, especially tribal populations and Dravidian populations of southern India. Populations in which the frequencies of haplogroup M are relatively lower show higher frequencies of haplogroup U; such populations are primarily caste populations of northern India. This finding is indicative of a higher Caucasoid admixture in northern Indian populations. By examining the sharing of haplotypes between Indian and south-east Asian populations, we have provided evidence that south-east Asia was peopled by two waves of migration, one originating in India and the other originating in southern China. These findings have been examined and interpreted in the light of inferences derived from previous genomic and historical studies

    Effects of isopropanol on collagen fibrils in new parchment

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    Background: Isopropanol is widely used by conservators to relax the creases and folds of parchment artefacts. At present, little is known of the possible side effects of the chemical on parchments main structural component- collagen. This study uses X-ray Diffraction to investigate the effects of a range of isopropanol concentrations on the dimensions of the nanostructure of the collagen component of new parchment. Results: It is found in this study that the packing features of the collagen molecules within the collagen fibril are altered by exposure to isopropanol. The results suggest that this chemical treatment can induce a loss of structural water from the collagen within parchment and thus a rearrangement of intermolecular bonding. This study also finds that the effects of isopropanol treatment are permanent to parchment artefacts and cannot be reversed with rehydration using deionised water. Conclusions: This study has shown that isopropanol induces permanent changes to the packing features of collagen within parchment artefacts and has provided scientific evidence that its use to remove creases and folds on parchment artefacts will cause structural change that may contribute to long-term deterioration of parchment artefacts. This work provides valuable information that informs conservation practitioners regarding the use of isopropanol on parchment artefacts

    Application of nanotechnology in antimicrobial finishing of biomedical textiles

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    In recent years, the antimicrobial nanofinishing of biomedical textiles has become a very active, high-growth research field, assuming great importance among all available material surface modifications in the textile industry. This review offers the opportunity to update and critically discuss the latest advances and applications in this field. The survey suggests an emerging new paradigm in the production and distribution of nanoparticles for biomedical textile applications based on non-toxic renewable biopolymers such as chitosan, alginate and starch. Moreover, a relationship among metal and metal oxide nanoparticle (NP) size, its concentration on the fabric, and the antimicrobial activity exists, allowing the optimization of antimicrobial functionality.Andrea Zille (C2011-UMINHO-2C2T-01) acknowledges funding from Programa Compromisso para a Ciencia 2008, Portugal

    Non-Markovian dynamics for an open two-level system without rotating wave approximation: Indivisibility versus backflow of information

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    By use of the two measures presented recently, the indivisibility and the backflow of information, we study the non-Markovianity of the dynamics for a two-level system interacting with a zero-temperature structured environment without using rotating wave approximation (RWA). In the limit of weak coupling between the system and the reservoir, and by expanding the time-convolutionless (TCL) generator to the forth order with respect to the coupling strength, the time-local non-Markovian master equation for the reduced state of the system is derived. Under the secular approximation, the exact analytic solution is obtained and the sufficient and necessary conditions for the indivisibility and the backflow of information for the system dynamics are presented. In the more general case, we investigate numerically the properties of the two measures for the case of Lorentzian reservoir. Our results show the importance of the counter-rotating terms to the short-time-scale non-Markovian behavior of the system dynamics, further expose the relations between the two measures and their rationality as non-Markovian measures. Finally, the complete positivity of the dynamics of the considered system is discussed

    DNA sequence variation and haplotype structure of the ICAM1 and TNF genes in 12 ethnic groups of India reveal patterns of importance in designing association studies

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    We have examined the patterns of DNA sequence variation in and around the genes coding for ICAM1 and TNF, which play functional and correlated roles in inflammatory processes and immune cell responses, in 12 diverse ethnic groups of India. We aimed to (a) quantify the nature and extent of the variation, and (b) analyse the observed patterns of variation in relation to population history and ethnic background. At the ICAM1 and TNF loci, respectively, the total numbers of SNPs that were detected were 28 and 12. Many of these SNPs are not shared across ethnic groups and are unreported in the dbSNP or TSC databases, including two fairly common non-synonymous SNPs at positions 13487 and 13542 in the ICAM1 gene. Conversely, the TNF-376A SNP that is reported to be associated with susceptibility to malaria was not found in our study populations, even though some of the populations inhabit malaria endemic areas. Wide between-population variation in the frequencies of shared SNPs and coefficients of linkage disequilibrium have been observed. These findings have profound implications in case-control association studies
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