334 research outputs found

    Laser performance of perylenebis (dicarboximide) dyes with long secondary alkyl chains

    Get PDF
    The laser performance and related photophysical properties of two very soluble perylene dyes with long chain secondary alkyl groups were investigated in cyclohexane solution. With a dye laser as pump source a tuning range of 555–580 nm was obtained at an optimum concentration of 3×10–4 M. The quantum efficiencies (=0.29 and 0.21) were better than 1/2 that of rhodamine 6G. No photodegradation was observed over an excitation period of several hours

    Hybrid Mechanical Systems

    Full text link
    We discuss hybrid systems in which a mechanical oscillator is coupled to another (microscopic) quantum system, such as trapped atoms or ions, solid-state spin qubits, or superconducting devices. We summarize and compare different coupling schemes and describe first experimental implementations. Hybrid mechanical systems enable new approaches to quantum control of mechanical objects, precision sensing, and quantum information processing.Comment: To cite this review, please refer to the published book chapter (see Journal-ref and DOI). This v2 corresponds to the published versio

    Sexual expression and cognitive function: gender-divergent associations in older adults

    Get PDF
    Prior research demonstrates a positive association between sexual activity and cognitive function in later life. However, the relationship between the type of sexual activity and cognitive function in older adulthood remains unclear. This study explores the associations between the frequency of engaging in different types of sexual activities (intercourse, masturbation, and kissing/petting/fondling) and cognitive function in older women and men. Using data from Wave 6 of the English Longitudinal Study of Ageing (ELSA), 1915 women and 2195 men (age range 50-89 years; n = 4110) reporting any type of sexual activity over the past 12 months, were included in the study. Multiple regression controlling for age, education, satisfaction with sex life, cohabiting, wealth, general health, physical activity, depression and loneliness, was used to explore the associations between the frequency of engagement in intercourse, masturbation and kissing/petting/fondling, and two measures of cognitive function; word recall and number sequencing. For women, masturbation was linked to better word recall (p = .008), whilst for men, kissing/petting/fondling was associated with better number sequencing (p = .035). In women (p = .016) and men (p = .018), dissatisfaction with sex life was associated with better number sequencing. The results point to gendered links between sexual activity and cognitive function. These gender-related divergences may reflect differences in biological/neurological mechanisms, or in cognitive lifestyle factors that could influence cognitive reserve in later life. This novel study underscores the need to delineate the underlying mechanisms of the association between sex and cognition in men and women

    Recreational and occupational field exposure to freshwater cyanobacteria – a review of anecdotal and case reports, epidemiological studies and the challenges for epidemiologic assessment

    Get PDF
    Cyanobacteria are common inhabitants of freshwater lakes and reservoirs throughout the world. Under favourable conditions, certain cyanobacteria can dominate the phytoplankton within a waterbody and form nuisance blooms. Case reports and anecdotal references dating from 1949 describe a range of illnesses associated with recreational exposure to cyanobacteria: hay fever-like symptoms, pruritic skin rashes and gastro-intestinal symptoms are most frequently reported. Some papers give convincing descriptions of allergic reactions while others describe more serious acute illnesses, with symptoms such as severe headache, pneumonia, fever, myalgia, vertigo and blistering in the mouth. A coroner in the United States found that a teenage boy died as a result of accidentally ingesting a neurotoxic cyanotoxin from a golf course pond. This death is the first recorded human fatality attributed to recreational exposure to cyanobacteria, although uncertainties surround the forensic identification of the suspected cyanotoxin in this case. We systematically reviewed the literature on recreational exposure to freshwater cyanobacteria. Epidemiological data are limited, with six studies conducted since 1990. Statistically significant increases in symptoms were reported in individuals exposed to cyanobacteria compared to unexposed counterparts in two Australian cohort studies, though minor morbidity appeared to be the main finding. The four other small studies (three from the UK, one Australian) did not report any significant association. However, the potential for serious injury or death remains, as freshwater cyanobacteria under bloom conditions are capable of producing potent toxins that cause specific and severe dysfunction to hepatic or central nervous systems. The exposure route for these toxins is oral, from ingestion of recreational water, and possibly by inhalation. A range of freshwater microbial agents may cause acute conditions that present with features that resemble illnesses attributed to contact with cyanobacteria and, conversely, acute illness resulting from exposure to cyanobacteria or cyanotoxins in recreational waters could be misdiagnosed. Accurately assessing exposure to cyanobacteria in recreational waters is difficult and unreliable at present, as specific biomarkers are unavailable. However, diagnosis of cyanobacteria-related illness should be considered for individuals presenting with acute illness following freshwater contact if a description is given of a waterbody visibly affected by planktonic mass development

    Coherent optical spectroscopy in a biological semiconductor quantum dot-DNA hybrid system

    Get PDF
    We theoretically investigate coherent optical spectroscopy of a biological semiconductor quantum dot (QD) coupled to DNA molecules. Coupling with DNAs, the linear optical responses of the peptide QDs will be enhanced significantly in the simultaneous presence of two optical fields. Based on this technique, we propose a scheme to measure the vibrational frequency of DNA and the coupling strength between peptide QD and DNA in all-optical domain. Distinct with metallic quantum dot, biological QD is non-toxic and pollution-free to environment, which will contribute to clinical medicine experiments. This article leads people to know more about the optical behaviors of DNAs-quantum dot system, with the currently popular pump-probe technique

    Inequalities in public water supply fluoridation in Brazil: An ecological study

    Get PDF
    Background. The literature is scarce on the social and geographic inequalities in the access to and implementation of the fluoridation of public water supplies. This study adds knowledge to the Brazilian experience of the chronic privation of water and wastewater policies, access to potable water and fluoridation in the country. Thus, the aim of this study was to verify possible inequalities in the population's access to fluoridated drinking water in 246 Brazilian municipalities. Methods. The information on the process of water fluoridation in the municipalities and in the macro region in which each municipality is located was obtained from the national epidemiological survey which was concluded in 2003. The data relating to the human development index at municipal level (HDI-M) and access to mains water came from the Brazilian Human Development Atlas, whilst the size of the population was obtained from a governmental source. The Fisher exact test (P < 0.05) was employed to identify significant associations between the explanatory variables and their ability to predict the principal outcomes of interest to this study, namely the presence or absence of the water fluoridation process in the municipalities as well as the length of time during which this measure has been implemented. Linear regression was used to observe the associations between the relevant variables in a multivariate environment. Results. The results clearly showed that there is a relationship between municipalities with larger populations, located in more socio-economically advantaged regions and with better HDI-M, and where fluoridation is both present and has been implemented for a longer period of time (started before 1990). Conclusion. The findings suggest that the aim of treating water with fluoride may not be being adequately achieved, requiring more effective strategies so that access to this measure can be expanded equitably.81Hart, J.T., The inverse care law (1971) Lancet, 1 (7696), pp. 405-12. , 4100731Victora, C.G., Vaughan, J.P., Barros, F.C., Silva, A.C., Tomasi, E., Explaining trends in inequities: Evidence from Brazilian child health studies (2000) Lancet, 356 (9235), pp. 1093-98. , 10.1016/S0140-6736(00)02741-0 11009159Basting, R.T., Pereira, A.C., Meneghim, M.C., Evaluation of dental caries prevalence in students from Piracicaba, SP, Brazil, after 25 years of fluoridation of the public water supply (1997) Rev Odontol Univ São Paulo, 11 (4), pp. 287-92. , 10.1590/S0103-06631997000400010Lawrence, H.P., Sheiham, A., Caries progression in 12 to 16-year-old schoolchildren in fluoridated and fluoride-deficient areas in Brazil (1997) Community Dent Oral Epidemiol, 25 (6), pp. 402-11. , 10.1111/j.1600-0528.1997.tb01730.x 9429812Pereira, A.C., Mialhe, F.L., Bianchini, F.L.C., Prevalence of caries and dental floozies in scholars from cities with different fluoride concentrations in drinking water (2001) Rev Bras Odontol Sade Coletiva, 2 (1), pp. 34-9For Disease Control, C., Prevention, Achievementsin Public Health, 1900-1999: Fluoridation of drinking water to prevent dental caries (1999) Morbidity and Mortality Weekly Report, 48 (41), pp. 933-40For Disease Control, C., Prevention, Ten great public health achievements -United Sates, 1900-1999 (1999) Morbidity and Mortality Weekly Report, 48 (12), pp. 241-3. , 10220250American Health Organization, P., XV Directing Council of the Pan American Health Organization - Resolutions, 1964, , http://www.paho.org/English/GOV/CD/ftcd_15.htm(2003) The World Oral Health Report 2003, , http://www.who.int/oral_health, Geneva: WHOMcDonagh, M.S., Whiting, P.F., Wilson, P.M., Sutton, A.J., Chestnutt, I., Cooper, J., Misso, K., Kleijnen, J., Systematic review of water fluoridation (2000) BMJ, 321 (7265), pp. 855-9. , 11021861 10.1136/bmj.321.7265.855Bratthall, D., Hänsel-Petersson, G., Sundberg, H., Reasons for the caries decline: What do the experts believe? (1996) Eur J Oral Sci, 104 (4 PART 2), pp. 416-22. , 10.1111/j.1600-0722.1996.tb00104.x 8930592Narvai, P.C., Dental caries and fluorine: A twentieth century relation (2000) Cinc Sade Coletiva, 5 (2), pp. 381-92. , 10.1590/S1413-81232000000200011Peres, M.A., Fernandes, L.S., Peres, K.G., Inequality of water fluoridation in Southern Brazil - The inverse equity hypothesis revisited (2004) Soc Sci Med, 58 (6), pp. 1181-9. , 10.1016/S0277-9536(03)00289-2 14723912Peres, M.A., Antunes, J.L.F., Peres, K.G., Is water fluoridation effective in reducing inequalities in dental caries distribution in developing countries? (2006) Sozial und Präventiv Medizin, 51 (5), pp. 1-9Peres, K.G., Bastos, J.R., Mrdo, L., Relationship between severity of dental caries and social and behavioral factors in children (2000) Rev Saude Publica, 34 (4), pp. 402-8. , 10973161Maltz, M., Barbachan Silva, E.B., Relationship between caries, gingivitis and fluorosis and the socioeconomic status among school children (2001) Rev Saude Publica, 35 (2), pp. 170-6. , 11359204Moysés, S.J., Desigualdades em Sade Bucal e Desenvolvimento Humano: Um ensaio em preto, branco e alguns tons de cinza (2001) Rev Bras Odontol Sade Coletiva, 1 (1), pp. 7-17Patussi, M.P., Marcenes, W., Croucher, R., Sheiham, A., Social deprivation, income inequality, social cohesion and dental caries in Brazilian school children (2001) Soc Sci Med, 53 (7), pp. 915-25. , 10.1016/S0277-9536(00)00391-9 11522137Antunes, J.L.F., Frazão, P., Narvai, P.C., Bispo, C.M., Pegoretti, T., Spatial analysis to identify differentials in dental needs by area-based measures (2002) Community Dent Oral Epidemiol, 30 (2), pp. 133-42. , 10.1034/j.1600-0528.2002.300207.x 12000354Peres, M.A., Peres, K.G., Antunes, J.L.F., Junqueira, S.R., Frazão, P., Narvai, P.C., The association between socioeconomic development at the town level and the distribution of dental caries in Brazilian children (2003) Rev Panam Salud Publica, 14 (3), pp. 149-57. , 10.1590/S1020-49892003000800001 14653902Antunes, J.L.F., Narvai, P.C., Nugent, Z.J., Measuring inequalities in the distribution of dental caries (2004) Community Dent Oral Epidemiol, 32 (1), pp. 41-8. , 10.1111/j.1600-0528.2004.00125.x 14961839Antunes, J.L.F., Peres, M.A., De Campos Mello, T.R., Waldman, E.A., Multilevel assessment of determinants of dental caries experience in Brazil (2006) Community Dent Oral Epidemiol, 34 (2), pp. 146-152. , 10.1111/j.1600-0528.2006.00274.x 16515679Narvai, P.C., Frazão, P., Roncalli, A.G., Antunes, J.L.F., Dental caries in Brazil: Decline, polarization, inequality and social exclusion (2006) Rev Panam Salud Publica, 19 (6), pp. 385-93. , 10.1590/S1020-49892006000600004 16968593Projeto, S.B., Brasil, Condiçes de sade bucal da população brasileira 2002-2003. Resultados principais (2004) Brasília-DF: Ministério da Sade, Secretaria de Atenção Sade, Departamento de Atenção Básica, Coordenação Nacional de Sade BucalCarmichael, C.L., Rugg-Gunn, A.J., French, A.D., Cranage, J.D., The effect of fluoridation upon the relationship between caries experience and social class in 5-year-old children in Newcastle and Northumberland in 1987 (1980) Br Dent J, 149 (6), pp. 163-7. , 10.1038/sj.bdj.4804479 6931610Bradnock, G., Marchment, M.D., Anderson, R.J., Social background, fluoridation and caries experience in 5-year-old population in the West Midlands (1984) Br Denl J, 156 (4), pp. 127-31. , 10.1038/sj.bdj.4805287 6584119Jones, C.M., Taylor, G.O., Whittle, J.G., Evans, D., Trotter, D.P., Water fluoridation, tooth decay in 5 years olds, and social deprivation measured by the Jarman score: Analysis of data from British dental surveys (1997) BMJ, 315 (7107), pp. 514-17. , 9329305Riley, J.C., Lennon, M.A., Ellwood, R.P., The effect of water fluoridation and social inequalities on dental caries in 5-year-old children (1999) Int Dent J, 28 (2), pp. 300-5. , 10342695Congresso Nacional, Brasil., Lei Federal no. de 19/09/1990 (1990) Diário Oficial da União 20 Set, p. 18055Morgenstern, H., Ecological studies (1998) Modern Epidemiology, pp. 459-80. , Baltimore: Lippincot Williamns & Wilkins Rothman K, Greenland S(2000) Informaçes de Sade: População Residente, , http://w3.datasus.gov.br/datasus/datasus.php?area= 359A1B379C6D0E0F359G23HIJd6L26M0N&VInclude=./site/infsaude.php, Departamento de Informática do Sistema nico de Sade (DATASUS)(2003) Atlas Do Desenvolvimento Humano No Brasil, Versão 1.0.0, , Programa das Naçes Unidas para o Desenvolvimento Brasília: PNUDLallo, R., Myburgh, N.G., Hobdell, M.H., Dental caries, socio-economic development and national oral health profiles (1999) Int Dent J, 49, pp. 196-202. , 10858754Baldani, M.H., Narvai, P.C., Antunes, J.L.F., Cárie dentária e condiçes scio-econômicas no Estado do Paraná, Brasil, 1996 (2002) Cad Sade Pblica, 18 (3), pp. 755-63. , 10.1590/S0102-311X2002000300024Qizilbash, M., On the Measurement of Human Development (2002) UNDP, , http://hdr.undp.org/docs/training/oxford/presentations/ Qizilbash_HDIcritique.pdfBurt, B.A., Fluoridation and social equity (2002) J Public Health Dent, 62 (4), pp. 195-200. , 10.1111/j.1752-7325.2002.tb03445.x 12474623For Disease Control, C., Prevention, Recommendation focusing fluoride to prevent and control dental caries in the United States (2001) Morbidity and Mortality Weekly Report, 50 (14), pp. 1-42Griffin, S.O., Jones, K., Tomar, S.L., An economic evaluation of community water fluoridation (2001) J Public Health Dent, 61 (2), pp. 78-86. , 10.1111/j.1752-7325.2001.tb03370.x 11474918Bleicher, L., Frota, F.H.S., Fluoretação da água: Uma questão de política pblica - O caso do Estado do Ceará (2006) Cin Sade Coletiva, 11 (1), pp. 71-8Frias, A.C., Narvai, P.C., Arajo, M.E., Zilbovicius, C., Antunes, J.L.F., Custo da fluoretação das águas de abastecimento pblico, estudo de caso -Município de São Paulo, Brasil, período de 1985-2003 (2006) Cad Sade Pblica, 22 (6), pp. 1237-46. , 10.1590/S0102-311X2006000600013Congresso Nacional, Brasil., (1974) Lei Federal No. 6.050, 3, p. 107. , Brasília: Departamento de Imprensa Nacional Atos do Poder Legislativo. Leis de Abril a JunhoDuarte, C.M.R., Eqüidade na legislação: Um princípio do sistema de sade brasileiro? (2000) Cin Sade Coletiva, 5 (2), pp. 443-63Whitehead, M., The concepts and principles of equity and health (1992) Int J Health Serv, 22 (3), pp. 429-45. , 10.2190/986L-LHQ6-2VTE-YRRN 164450

    NSC23925, Identified in a High-Throughput Cell-Based Screen, Reverses Multidrug Resistance

    Get PDF
    Multidrug resistance (MDR) is a major factor which contributes to the failure of cancer chemotherapy, and numerous efforts have been attempted to overcome MDR. To date, none of these attempts have yielded a tolerable and effective therapy to reverse MDR; thus, identification of new agents would be useful both clinically and scientifically.To identify small molecule compounds that can reverse chemoresistance, we developed a 96-well plate high-throughput cell-based screening assay in a paclitaxel resistant ovarian cancer cell line. Coincubating cells with a sublethal concentration of paclitaxel in combination with each of 2,000 small molecule compounds from the National Cancer Institute Diversity Set Library, we identified a previously uncharacterized molecule, NSC23925, that inhibits Pgp1 and reverses MDR1 (Pgp1) but does not inhibit MRP or BCRP-mediated MDR. The cytotoxic activity of NSC23925 was further evaluated using a panel of cancer cell lines expressing Pgp1, MRP, and BCRP. We found that at a concentration of >10 microM NSC23925 moderately inhibits the proliferation of both sensitive and resistant cell lines with almost equal activity, but its inhibitory effect was not altered by co-incubation with the Pgp1 inhibitor, verapamil, suggesting that NSC23925 itself is not a substrate of Pgp1. Additionally, NSC23925 increases the intracellular accumulation of Pgp1 substrates: calcein AM, Rhodamine-123, paclitaxel, mitoxantrone, and doxorubicin. Interestingly, we further observed that, although NSC23925 directly inhibits the function of Pgp1 in a dose-dependent manner without altering the total expression level of Pgp1, NSC23925 actually stimulates ATPase activity of Pgp, a phenomenon seen in other Pgp inhibitors.The ability of NSC23925 to restore sensitivity to the cytotoxic effects of chemotherapy or to prevent resistance could significantly benefit cancer patients
    • …
    corecore