211 research outputs found

    Synthesis Of Carbon Nitride Films At Low Temperatures

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    Carbon nitride films (CN x) have been deposited by sputtering a graphite target with nitrogen ions. Films were grown both with and without the presence of an assisting focused N 2 ion beam. The sputter beam voltage was varied between 150 and 1500 V and the applied assisting beam voltage from 80 to 500 V. The substrate was held at fixed temperatures between 80 and 673 K. The coatings were characterized with respect to their electrical, optical, and structural properties. The nitrogen content was measured by x-ray photoelectron spectroscopy (XPS) and a maximum nitrogen concentration of 44 at. % was obtained for a nonassisted sample deposited at 140 K. The chemical structure was investigated by XPS and Fourier transform infrared spectroscopy. Reduction of the substrate temperature in conjunction with low sputter beam voltages (<200 V) caused the optical band gap to increase up to 2.2 eV, the sheet conductivity to decrease to less th an 10 -9 (Ω cm) -1 and the density to be reduced to 1.6 g/cm 3. The increasing transparency is accompanied by structural changes indicating a transition from a predominantly sp 2 bonded amorphous sp 2/sp 3 C-N network to a more linear polymerlike structure consisting predominantly of doubly and triply bonded C and N atoms. No evidence for the formation of the β-C 3N 4 phase was found. © 1997 American Vacuum Society.151107112Hammer, P., Gissler, W., (1996) Diam. Relat. Mater., 5, p. 1152Hammer, P., Baker, M.A., Lenardi, C., Gissler, W., Thin Solid Films, , to be publishedTodorov, S.S., Marton, D., Boyd, K.J., Al-Bayati, A.H., Rabalais, J.W., (1994) J. Vac. Sci. Technol. A, 12, p. 3192Liu, A.Y., Cohen, M.L., (1990) Phys. Rev. B, 41, p. 10727Baker, M.A., Hammer, P., Surf. Interface Anal., , submittedKaufman, J.H., Metin, S., Saperstein, D.D., (1989) Phys. Rev. B, 39, p. 13053Dolphin, D., Wick, A., (1977) Tabulation of Infrared Spectral Data, , Wiley, New YorkSocrates, G., (1980) Infrared Characteristic Group Frequencies, , Wiley, Chichester, U.KSjöström, H., Stafström, S., Boman, M., Sundgren, J.E., (1995) Phys. Rev. Lett., 75, p. 1336Marton, D., Al-Bayati, A.H., Todorov, S.S., Boyd, K.J., Rabalais, J.W., (1994) Nucl. Instrum. Methods Phys. Res. B, 90, p. 277Sjöström, H., Hultman, L., Sundgren, J.-E., Hainsworth, S.V., Page, T.F., Theunissen, G.S.A.M., (1996) J. Vac. Sci. Technol. A, 14, p. 56Briggs, D., Clark, D.T., Keable, H.R., Kilner, M., (1973) J. Chem. Soc. Dalton Trans., p. 2143Barber, M., Conner, J.A., Guest, M.F., Hillier, I.H., Schwartz, M., Stacey, M., (1973) J. Chem. Soc. Faraday Trans. II, 69, p. 551Bircumshaw, L.L., Tayler, F.M., Whiffen, D.H., (1954) J. Chem. Soc., p. 93

    Use of psychotropic drugs before pregnancy and the risk for induced abortion: population-based register-data from Finland 1996-2006

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    <p>Abstract</p> <p>Background</p> <p>Some, though not all studies have reported an increased risk for mental health problems after an induced abortion. Problems with design and data have compromised these studies and the generalisation of their results.</p> <p>Methods</p> <p>The Finnish Medication and Pregnancy database (N = 622 671 births and 114 518 induced abortions for other than fetal reasons) in 1996-2006 was utilised to study the use of psychotropic drugs in the three months before a pregnancy ending in a birth or an induced abortion.</p> <p>Results</p> <p>In total 2.1% of women with a birth and 5.1% of women with an induced abortion had used a psychotropic medicine 0-3 months before pregnancy. Psychotropic drug users terminated their pregnancies (30.9%) more often than other pregnant women (15.5%). Adjustment for background characteristics explained one third of this elevated risk, but the risk remained significantly increased among users of psychotropic medicine (OR 1.94, 95% confidence intervals 1.87-2.02). A similar risk was found for first pregnancies (30.1% vs. 18.9%; adjusted OR 1.53, 95% confidence intervals 1.42-1.65). The rate for terminating pregnancy was the highest for women using hypnotics and sedatives (35.6% for all pregnancies and 29.1% for first pregnancies), followed by antipsychotics (33.9% and 36.0%) and antidepressants (32.0% and 32.1%).</p> <p>Conclusions</p> <p>The observed increased risk for induced abortion among women with psychotropic medication highlighs the importance to acknowledge the mental health needs of women seeking an induced abortion. Further studies are needed to establish the impact of pre-existing differences in mental health on mental health outcomes of induced abortions compared to outcomes of pregnancies ending in a birth.</p

    Synthesis of carbon nitride films at low temperatures

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    Carbon nitride films (CNx) have been deposited by sputtering a graphite target with nitrogen ions. Films were grown both with and without the presence of an assisting focused N-2 ion beam. The sputter beam voltage was varied between 150 and 1500 V and the applied assisting beam voltage from 80 to 500 V. The substrate was held at fixed temperatures between 80 and 673 K. The coatings were characterized with respect to their electrical, optical; and structural properties. The nitrogen content was measured by x-ray photoelectron spectroscopy (XPS) and a maximum nitrogen concentration of 44 at. % was obtained for a nonassisted sample deposited at 140 K. The chemical structure was investigated by XPS and Fourier transform infrared spectroscopy. Reduction of the substrate temperature in conjunction with low sputter beam voltages (<200 V) caused the optical band gap to increase up to 2.2 eV, the sheet conductivity to decrease to less than 10(-9) (Omega cm)(-1) and the density to be reduced to 1.6 g/cm(3). The increasing transparency is accompanied by structural changes indicating a transition from a predominantly sp(2) bonded amorphous sp(2)/sp(3) C-N network to a more linear polymerlike structure consisting predominantly of doubly and triply bonded C and N atoms. No evidence for the formation of the beta-C3N4 phase was found

    Maternal care and birth outcomes among ethnic minority women in Finland

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    <p>Abstract</p> <p>Background</p> <p>Care during pregnancy and labour is of great importance in every culture. Studies show that people of migrant origin have barriers to obtaining accessible and good quality care compared to people in the host society. The aim of this study is to compare the access to and use of maternity services, and their outcomes among ethnic minority women having a singleton birth in Finland.</p> <p>Methods</p> <p>The study is based on data from the Finnish Medical Birth Register in 1999–2001 linked with the information of Statistics Finland on woman's country of birth, citizenship and mother tongue. Our study data included 6,532 women of foreign origin (3.9% of all singletons) giving singleton birth in Finland during 1999–2001 (compared to 158,469 Finnish origin singletons).</p> <p>Results</p> <p>Most women have migrated during the last fifteen years, mainly from Russia, Baltic countries, Somalia and East Europe. Migrant origin women participated substantially in prenatal care. Interventions performed or needed during pregnancy and childbirth varied between ethnic groups. Women of African and Somali origin had most health problems resulted in the highest perinatal mortality rates. Women from East Europe, the Middle East, North Africa and Somalia had a significant risk of low birth weight and small for gestational age newborns. Most premature newborns were found among women from the Middle East, North Africa and South Asia. Primiparous women from Africa, Somalia and Latin America and Caribbean had most caesarean sections while newborns of Latin American origin had more interventions after birth.</p> <p>Conclusion</p> <p>Despite good general coverage of maternal care among migrant origin women, there were clear variations in the type of treatment given to them or needed by them. African origin women had the most health problems during pregnancy and childbirth and the worst perinatal outcomes indicating the urgent need of targeted preventive and special care. These study results do not confirm either healthy migrant effect or epidemiological paradox according to which migrant origin women have considerable good birth outcomes.</p

    ViPAR: a software platform for the Virtual Pooling and Analysis of Research Data

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    Background: Research studies exploring the determinants of disease require sufficient statistical power to detect meaningful effects. Sample size is often increased through centralized pooling of disparately located datasets, though ethical, privacy and data ownership issues can often hamper this process. Methods that facilitate the sharing of research data that are sympathetic with these issues and which allow flexible and detailed statistical analyses are therefore in critical need. We have created a software platform for the Virtual Pooling and Analysis of Research data (ViPAR), which employs free and open source methods to provide researchers with a web-based platform to analyse datasets housed in disparate locations. Methods: Database federation permits controlled access to remotely located datasets from a central location. The Secure Shell protocol allows data to be securely exchanged between devices over an insecure network. ViPAR combines these free technologies into a solution that facilitates 'virtual pooling' where data can be temporarily pooled into computer memory and made available for analysis without the need for permanent central storage. Results: Within the ViPAR infrastructure, remote sites manage their own harmonized research dataset in a database hosted at their site, while a central server hosts the data federation component and a secure analysis portal. When an analysis is initiated, requested data are retrieved from each remote site and virtually pooled at the central site. The data are then analysed by statistical software and, on completion, results of the analysis are returned to the user and the virtually pooled data are removed from memory. Conclusions: ViPAR is a secure, flexible and powerful analysis platform built on open source technology that is currently in use by large international consortia, and is made publicly available at [http://bioinformatics.childhealthresearch.org.au/software/vipar/]
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