Effect of Cationic Surfactant Head Groups on Synthesis, Growth and Agglomeration Behavior of ZnS Nanoparticles

Colloidal nanodispersions of ZnS have been prepared using aqueous micellar solution of two cationic surfactants of trimethylammonium/pyridinium series with different head groups i.e., cetyltrimethylammonium chloride (CTAC) and cetyltrimethylpyridinium chloride (CPyC). The role of these surfactants in controlling size, agglomeration behavior and photophysical properties of ZnS nanoparticles has been discussed. UV–visible spectroscopy has been carried out for determination of optical band gap and size of ZnS nanoparticles. Transmission electron microscopy and dynamic light scattering were used to measure sizes and size distribution of ZnS nanoparticles. Powder X-ray analysis (Powder XRD) reveals the cubic structure of nanocrystallite in powdered sample. The photoluminescence emission band exhibits red shift for ZnS nanoparticles in CTAC compared to those in CPyC. The aggregation behavior in two surfactants has been compared using turbidity measurements after redispersing the nanoparticles in water. In situ evolution and growth of ZnS nanoparticles in two different surfactants have been compared through time-dependent absorption behavior and UV irradiation studies. Electrical conductivity measurements reveal that CPyC micelles better stabilize the nanoparticles than that of CTAC

Prevalence of high - risk human papillomavirus infections in women with benign cervical cytology: A hospital based study from North India

INTRODUCTION: Cervical cancer is the commonest cancer among Indian women. High-risk human papillomavirus (HPV) detection holds the potential to be used as a tool to identify women, at risk for subsequent development of cervical cancer. There is a pressing need for identifying prevalence of asymptomatic cervical HPV infection in the local population. OBJECTIVE: To determine the prevalence of high-risk HPV DNA in women with benign cervical cytology. MATERIALS AND METHODS: Women visiting the gynecology outpatient with varied complaints were subjected to Pap smear. Four hundred and seventy two samples were subjected to polymerase chain reaction, using consensus primers for low and high-risk HPV (types 6, 11, 16, 18, 31 and 33). The samples that were positive for HPV DNA were subsequently assessed for high-risk consensus primers, types 16, 18, 31 and 33 as well as for HPV type 16 and 18. RESULTS: One hundred and seventy four (36.8%) women tested positive for HPV DNA. Thirty nine (8.2%) of the entire cohort tested positive for high-risk HPV. Fifteen samples were positive for type 16, 22 for type 18 and two for both types 16 and 18. A statistically higher prevalence of high-risk HPV was observed in poorly educated and rural groups. No association of HPV prevalence was noted with age, parity and age at marriage. CONCLUSION: The study generates epidemiological data of prevalence of sub-clinical HPV in the women visiting a tertiary care institute as well as peripheral health centres. The data generated will be useful for laying guidelines for mass screening of HPV, treatment and prophylaxis in the local population

Validating MOSPA questionnaire for measuring physical activity in Pakistani women

BACKGROUND: Precise measurements of activity at a population level are important for monitoring trends and evaluating health promotion strategies. Few studies have assessed the measurement of physical activity in developing countries. The aim of this study was to validate the MOSPA (Monica Optional Study of Physical Activity) questionnaire which was developed for the WHO-Monitoring trends and determinants of cardiovasculr disease (MONICA) study sites. METHODS: The MOSPA questionnaire assesses energy expendtiture (EE) related to physical activity (employment, household work, transportation, and leisure time) over a one year period. This questionnaire has been described in the manuscript as the long term (LT) questionnaire. An adapted short term (ST) 5 day questionnaire was developed to assess convergent validity. Questionnaire data were compared with physical activity EE estimates from a Caltrac accelerometer and with body composition measures (height, weight and bioelectrical impedance) in 50 women from the Aga Khan University (AKU) hospital antenatal clinics, Pakistan. Other forms of EE i.e. resting EE and thermic effect of food were not assessd in this study. RESULTS: Subjects were aged 26 ± 3.8 years and were 16.1 ± 6.7 weeks pregnant. Their average weight was 58.8 ± 10.7 Kg. The average EE/day assessed by the Caltrac accelerometer, was 224 kcal and by MOSPA LT questionnaire it was 404 kcal. The questionnaires and Caltrac data were reasonably well correlated: r = 0.51 and r = 0.60 (P < 0.01) for LT and ST questionnaires respectively. Energy expenditure from questionnaire data was not correlated with body composition measures. CONCLUSION: The MOSPA questionnaire is useful in assessing physical activity levels in a sedentary population over a one year period

Azimuthal anisotropy and correlations at large transverse momenta in p+pp+p and Au+Au collisions at sNN\sqrt{s_{_{NN}}}= 200 GeV

Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au+Au collisions at $\sqrt{s_{_{NN}}}$= 200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au+Au collisions to those in $p+p$ at the same energy. Elliptic anisotropy, $v_2$, is found to reach its maximum at $p_t \sim 3$ GeV/c, then decrease slowly and remain significant up to $p_t\approx 7$ -- 10 GeV/c. Stronger suppression is found in the back-to-back high-$p_t$ particle correlations for particles emitted out-of-plane compared to those emitted in-plane. The centrality dependence of $v_2$ at intermediate $p_t$ is compared to simple models based on jet quenching.Comment: 4 figures. Published version as PRL 93, 252301 (2004

Azimuthal anisotropy in Au+Au collisions at sqrtsNN = 200 GeV

The results from the STAR Collaboration on directed flow (v_1), elliptic flow (v_2), and the fourth harmonic (v_4) in the anisotropic azimuthal distribution of particles from Au+Au collisions at sqrtsNN = 200 GeV are summarized and compared with results from other experiments and theoretical models. Results for identified particles are presented and fit with a Blast Wave model. Different anisotropic flow analysis methods are compared and nonflow effects are extracted from the data. For v_2, scaling with the number of constituent quarks and parton coalescence is discussed. For v_4, scaling with v_2^2 and quark coalescence is discussed.Comment: 26 pages. As accepted by Phys. Rev. C. Text rearranged, figures modified, but data the same. However, in Fig. 35 the hydro calculations are corrected in this version. The data tables are available at http://www.star.bnl.gov/central/publications/ by searching for "flow" and then this pape

Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

Alternative splicing of the Anopheles gambiae Dscam gene in diverse Plasmodium falciparum infections

Background: In insects, including Anopheles mosquitoes, Dscam (Down syndrome cell adhesion molecule) appears to be involved in phagocytosis of pathogens, and shows pathogen-specific splice-form expression between divergent pathogen (or parasite) types (e.g. between bacteria and Plasmodium or between Plasmodium berghei and Plasmodium falciparum). Here, data are presented from the first study of Dscam expression in response to genetic diversity within a parasite species. Methods: In independent field and laboratory studies, a measure of Dscam splice-form diversity was compared between mosquitoes fed on blood that was free of P. falciparum to mosquitoes exposed to either single or mixed genotype infections of P. falciparum. Results: Significant increases in Anopheles gambiae Dscam (AgDscam) receptor diversity were observed in parasite-exposed mosquitoes, but only weak evidence that AgDscam diversity rises further upon exposure to mixed genotype parasite infections was found. Finally, a cluster of AgDscam exon 4 variants that become especially common during Plasmodium invasion was identified. Conclusions: While the data clearly indicate that AgDscam diversity increases with P. falciparum exposure, they do not suggest that AgDscam diversity rises further in response to increased parasite diversit

Sex-Related Differences in Gene Expression in Human Skeletal Muscle

There is sexual dimorphism of skeletal muscle, the most obvious feature being the larger muscle mass of men. The molecular basis for this difference has not been clearly defined. To identify genes that might contribute to the relatively greater muscularity of men, we compared skeletal muscle gene expression profiles of 15 normal men and 15 normal women by using comprehensive oligonucleotide microarrays. Although there were sex-related differences in expression of several hundred genes, very few of the differentially expressed genes have functions that are obvious candidates for explaining the larger muscle mass of men. The men tended to have higher expression of genes encoding mitochondrial proteins, ribosomal proteins, and a few translation initiation factors. The women had >2-fold greater expression than the men (P<0.0001) of two genes that encode proteins in growth factor pathways known to be important in regulating muscle mass: growth factor receptor-bound 10 (GRB10) and activin A receptor IIB (ACVR2B). GRB10 encodes a protein that inhibits insulin-like growth factor-1 (IGF-1) signaling. ACVR2B encodes a myostatin receptor. Quantitative RT-PCR confirmed higher expression of GRB10 and ACVR2B genes in these women. In an independent microarray study of 10 men and 9 women with facioscapulohumeral dystrophy, women had higher expression of GRB10 (2.7-fold, P<0.001) and ACVR2B (1.7-fold, P<0.03). If these sex-related differences in mRNA expression lead to reduced IGF-1 activity and increased myostatin activity, they could contribute to the sex difference in muscle size

DNA methylation patterns associate with genetic and gene expression variation in HapMap cell lines

BACKGROUND: DNA methylation is an essential epigenetic mechanism involved in gene regulation and disease, but little is known about the mechanisms underlying inter-individual variation in methylation profiles. Here we measured methylation levels at 22,290 CpG dinucleotides in lymphoblastoid cell lines from 77 HapMap Yoruba individuals, for which genome-wide gene expression and genotype data were also available. RESULTS: Association analyses of methylation levels with more than three million common single nucleotide polymorphisms (SNPs) identified 180 CpG-sites in 173 genes that were associated with nearby SNPs (putatively in cis, usually within 5 kb) at a false discovery rate of 10%. The most intriguing trans signal was obtained for SNP rs10876043 in the disco-interacting protein 2 homolog B gene (DIP2B, previously postulated to play a role in DNA methylation), that had a genome-wide significant association with the first principal component of patterns of methylation; however, we found only modest signal of trans-acting associations overall. As expected, we found significant negative correlations between promoter methylation and gene expression levels measured by RNA-sequencing across genes. Finally, there was a significant overlap of SNPs that were associated with both methylation and gene expression levels. CONCLUSIONS: Our results demonstrate a strong genetic component to inter-individual variation in DNA methylation profiles. Furthermore, there was an enrichment of SNPs that affect both methylation and gene expression, providing evidence for shared mechanisms in a fraction of genes

Population Differences in Transcript-Regulator Expression Quantitative Trait Loci

Gene expression quantitative trait loci (eQTL) are useful for identifying single nucleotide polymorphisms (SNPs) associated with diseases. At times, a genetic variant may be associated with a master regulator involved in the manifestation of a disease. The downstream target genes of the master regulator are typically co-expressed and share biological function. Therefore, it is practical to screen for eQTLs by identifying SNPs associated with the targets of a transcript-regulator (TR). We used a multivariate regression with the gene expression of known targets of TRs and SNPs to identify TReQTLs in European (CEU) and African (YRI) HapMap populations. A nominal p-value of <1×10−6 revealed 234 SNPs in CEU and 154 in YRI as TReQTLs. These represent 36 independent (tag) SNPs in CEU and 39 in YRI affecting the downstream targets of 25 and 36 TRs respectively. At a false discovery rate (FDR) = 45%, one cis-acting tag SNP (within 1 kb of a gene) in each population was identified as a TReQTL. In CEU, the SNP (rs16858621) in Pcnxl2 was found to be associated with the genes regulated by CREM whereas in YRI, the SNP (rs16909324) was linked to the targets of miRNA hsa-miR-125a. To infer the pathways that regulate expression, we ranked TReQTLs by connectivity within the structure of biological process subtrees. One TReQTL SNP (rs3790904) in CEU maps to Lphn2 and is associated (nominal p-value = 8.1×10−7) with the targets of the X-linked breast cancer suppressor Foxp3. The structure of the biological process subtree and a gene interaction network of the TReQTL revealed that tumor necrosis factor, NF-kappaB and variants in G-protein coupled receptors signaling may play a central role as communicators in Foxp3 functional regulation. The potential pleiotropic effect of the Foxp3 TReQTLs was gleaned from integrating mRNA-Seq data and SNP-set enrichment into the analysis