35 research outputs found

    Positioning system and lithographic projection apparatus

    Get PDF
    A lithographic apparatus has a positioning system for positioning an object table, said positioning system comprising a planar motor having a stator (10) and a translator (20), one of said stator and said translator comprising a periodic magnet structure (13-15) and the other of said stator and said translator comprising a plurality of energizable coils (21-24). The phase relationship between stator and translator of the planar motor is determined by: energizing a plurality of said energizable coils in turn with an oscillating signal sufficient to cause vibrations of said translator having an amplitude less than the period of said periodic magnet structure; measuring said vibrations of said translator; and determining the phase relationship between said translator and said stator on the basis of said measured vibrations. Alternatively, the relationship between stator and translator is be determined by detecting means detecting distinct optical marks on the periodic magnet array. Control means determine the relationship between said translator and said stator on the basis of detected distinct optical marks

    Positioning system and lithographic projection apparatus

    Get PDF
    A lithographic apparatus has a positioning system for positioning an object table, said positioning system comprising a planar motor having a stator (10) and a translator (20), one of said stator and said translator comprising a periodic magnet structure (13-15) and the other of said stator and said translator comprising a plurality of energizable coils (21-24). The phase relationship between stator and translator of the planar motor is determined by: energizing a plurality of said energizable coils in turn with an oscillating signal sufficient to cause vibrations of said translator having an amplitude less than the period of said periodic magnet structure; measuring said vibrations of said translator; and determining the phase relationship between said translator and said stator on the basis of said measured vibrations. Alternatively, the relationship between stator and translator is be determined by detecting means detecting distinct optical marks on the periodic magnet array. Control means determine the relationship between said translator and said stator on the basis of detected distinct optical marks

    Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

    Get PDF
    Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

    Fractionation of five technical lignins by selective extraction in green solvents and characterization of isolated fractions

    No full text
    Lignins from softwood, hardwood, grass and wheat straw were fractionated by selective extraction at ambient temperature using green solvents like acetone/water solutions of 10, 30, 50, 70 and 90% (v/v) acetone and ethyl acetate. A comparison between the isolated fractions and unfractionated lignins was made in terms of extraction yield, lignin solubility factor, molecular weight distribution and functional group composition. Low molecular weight (LMW) lignin fractions with narrow dispersity are obtained by extraction with ethyl acetate and acetone–water solution containing 30% acetone, with yields depending on the type and the functional group content of lignins. A significant amount (56%) of the organosolv hardwood lignin with low molecular weight (Mw = 1868 g/mol) and low dispersity was isolated from ethyl acetate. Insoluble fractions with very high molecular weight (Mw between 10 and 17 kg/mol) are obtained in low yield from acetone–water solutions with 50, 70 and 90% acetone. LMW lignins are in general less condensed and have lower aliphatic hydroxyl content than parent lignins while the HMW fractions have a higher content of condensed hydroxyls. Principal component analysis on the chemical composition of lignins and isolated fractions determined from 31P NMR data showed the high heterogeneity of the technical lignins. Partial least squares models based on FT-IR spectral data were developed to predict the functional group content determined by quantitative 31P NMR analysis of technical lignins and lignin fractions. This approach can be used to develop simple, rapid and accurate analytical tools to monitor and control the selective fractionation of lignin

    Selectivity of lipases for estolides synthesis

    No full text
    Lipase-catalyzed synthesis of estolides starting from different saturated (C16 16OH, C18 12OH) and unsaturated (C18:1 9 cis 12-OH) hydroxy-fatty acids was investigated. For this reason, the catalytic efficiency of several native and immobilized lipases in different organic reaction media at temperatures up to 75 °C was studied. The formation of mono- and di-lactone as well as estolide’s chain elongation depends on the type and source of lipase. The lipase from Pseudomonas stutzeri immobilized by cross-linking as cross-linked enzymes aggregates (CLEAs) was the best biocatalyst in terms of chain elongation. Estolides with polymerization degree up to 10 were obtained at substrate conversions higher than 80 %

    Lipase catalyzed synthesis of aromatic esters of sugar alcohols

    No full text
    Commercially available lipases (Candida antarctica lipase B, Novozyme 435, Thermomyces lanuginosus lipase, and Lipozyme TL IM), as well as sol-gel immobilized lipases, have been screened for their ability to acylate regioselectively xylitol, sorbitol, and mannitol with a phenolic ester in a binary mixture of t-butanol and dimethylsulfoxide. HPLC and MALDI-TOF MS analysis revealed the exclusive formation of monoesters for all studied sugar alcohols. The lipases immobilized by the sol-gel entrapment method proved to be efficient catalysts, leading to high conversions (up to 60%) in the investigated acylation reactions. From a sequence of silane precursors with different nonhydrolyzable groups in their structure, the presence of octyl and i-butyl group was most beneficial for the catalytic activity of sol-gel entrapped lipases in the studied process

    Sol–gel immobilization of Alcalase from Bacillus licheniformis for application in the synthesis of C-terminal peptide amides

    No full text
    Alcalase 2.4L FG, a commercial preparation of Subtilisin A, was physically entrapped in glass sol–gel matrices using alkoxysilanes of different types mixed with tetramethoxysilane (TMOS). The materials were used for catalyzing C-terminal amidation of Z-Ala-Phe-OMe in a mixture of tert-butanol/DMF. From the screening of silane monomers in the sol–gel coating process, it was concluded that dimethyldimethoxysilane (DMDMOS) gave the best performance, and Alcalase immobilized therein exhibited the highest activity in the ammonolysis of Z-Ala-Phe-OMe. The percentage of protein immobilization was in the range of 68–98%, and total amidation activity of the immobilized Alcalase was up to 1.76 µmol/h/mg gel. We investigated the immobilization efficiency for a protein mass range of 2.8–9.7 mg per mmol total silanes, to determine the immobilization capacity of the biosilica support. The optimum enzyme loading capacity in the silica matrix was 115 mg/g dry silica xerogel (11.5%, w/w). The amount of the DMDMOS silicate was optimized by adjusting the molar ratio of silane mixture (DMDMOS and TMOS at 1:1). Biocatalyst sol–gel particles prepared at optimum immobilization conditions retained 100% of the original activity even after 14 cycles of repeated use. Reproducibility of the immobilization technique was also investigated by evaluating the catalytic efficiency of the obtained preparations. The thermal stability of the protease at 70 °C increased threefold upon entrapment in sol–gel materials, and twofold under storage for 50 days at ambient temperature
    corecore