59 research outputs found

    Studies of Fe(II) and Fe(III)-DNA complexes by XANES spectroscopy

    Get PDF
    The composition of the ligands around the iron centers in Fe(II) and Fe(III)-DNA complexes has been investigated by X-ray Absorption Near Edge Structure (XANES) spectroscopy at the Fe-K-edge. the spectra are compared to the models FePO4 and Fe(dadipy)(2), each one bearing only one of the ligands expected in the Fe-DNA interaction, namely oxygen (from phosphate groups, H2O or bases) and nitrogen (from bases), respectively. the spectrum of Fe(II)-DNA exhibits a higher pre-edge peak and a more prominent shoulder at 7145 eV than Fe(III)-DNA. These spectral features indicate a distortion associated with the the presence of nitrogen in the first coordination sphere Fe(II)-DNA. These spectral features indicate a distortion associated with the presence of nitrogen in the first coordenation sphere of Fe(II)DNA. Similarities between Fe(III)-DNA and FePO4 are consistent with the possibility that only oxygen atoms are coordinated to the Fe(III) center.UNIFESP, CEDEME, Escola Paulista Med, BR-04023090 São Paulo, BrazilUSP, IQ, Dept Bioquim, BR-05508900 São Paulo, BrazilLab Nacl Luz Sincrotron, BR-13083970 Campinas, SP, BrazilUNIFESP, CEDEME, Escola Paulista Med, BR-04023090 São Paulo, BrazilWeb of Scienc

    On the Effect of Thermodynamic Equilibrium on the Assembly Efficiency of Complex Multi-Layered Virus-Like Particles (VLP): the Case of Rotavirus VLP

    Get PDF
    Previous studies have reported the production of malformed virus-like-particles (VLP) in recombinant host systems. Here we computationally investigate the case of a large triple-layered rotavirus VLP (RLP). In vitro assembly, disassembly and reassembly data provides strong evidence of microscopic reversibility of RLP assembly. Light scattering experimental data also evidences a slow and reversible assembly untypical of kinetic traps, thus further strengthening the fidelity of a thermodynamically controlled assembly. In silico analysis further reveals that under favourable conditions particles distribution is dominated by structural subunits and completely built icosahedra, while other intermediates are present only at residual concentrations. Except for harshly unfavourable conditions, assembly yield is maximised when proteins are provided in the same VLP protein mass composition. The assembly yield decreases abruptly due to thermodynamic equilibrium when the VLP protein mass composition is not obeyed. The latter effect is more pronounced the higher the Gibbs free energy of subunit association is and the more complex the particle is. Overall this study shows that the correct formation of complex multi-layered VLPs is restricted to a narrow range of association energies and protein concentrations, thus the choice of the host system is critical for successful assembly. Likewise, the dynamic control of intracellular protein expression rates becomes very important to minimize wasted proteins

    Nursing Activities Score: nursing work load in a burns Intensive Care Unit

    Get PDF
    OBJECTIVE: to evaluate the nursing work load in a Burns Intensive Care Unit according to the Nursing Activities Score.METHOD: an exploratory, descriptive cross-sectional study with a quantitative approach. The Nursing Activities Score was used for data collection between October 2011 and May 2012, totalling 1,221 measurements, obtained from 50 patients' hospital records. Data for qualitative variables was described in tables; for the quantitative variables, calculations using statistical measurements were used.RESULTS: the mean score for the Nursing Activities Score was 70.4% and the median was 70.3%, corresponding to the percentage of the time spent on direct care to the patient in 24 hours.CONCLUSION: the Nursing Activities Score provided information which involves the process of caring for patients hospitalized in a Burns Intensive Care Unit, and indicated that there is a high work load for the nursing team of the sector studied

    Genetic diversity in cultivated carioca common beans based on molecular marker analysis

    Get PDF
    A wide array of molecular markers has been used to investigate the genetic diversity among common bean species. However, the best combination of markers for studying such diversity among common bean cultivars has yet to be determined. Few reports have examined the genetic diversity of the carioca bean, commercially one of the most important common beans in Brazil. In this study, we examined the usefulness of two molecular marker systems (simple sequence repeats – SSRs and amplified fragment length polymorphisms – AFLPs) for assessing the genetic diversity of carioca beans. The amount of information provided by Roger’s modified genetic distance was used to analyze SSR data and Jaccards similarity coefficient was used for AFLP data. Seventy SSRs were polymorphic and 20 AFLP primer combinations produced 635 polymorphic bands. Molecular analysis showed that carioca genotypes were quite diverse. AFLPs revealed greater genetic differentiation and variation within the carioca genotypes (Gst = 98% and Fst = 0.83, respectively) than SSRs and provided better resolution for clustering the carioca genotypes. SSRs and AFLPs were both suitable for assessing the genetic diversity of Brazilian carioca genotypes since the number of markers used in each system provided a low coefficient of variation. However, fingerprint profiles were generated faster with AFLPs, making them a better choice for assessing genetic diversity in the carioca germplasm

    Pooled analysis of who surgical safety checklist use and mortality after emergency laparotomy

    Get PDF
    Background: The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods: In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results: Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89⋅6 per cent) compared with that in countries with a middle (753 of 1242, 60⋅6 per cent; odds ratio (OR) 0⋅17, 95 per cent c.i. 0⋅14 to 0⋅21, P < 0⋅001) or low (363 of 860, 42⋅2 percent; OR 0⋅08, 0⋅07 to 0⋅10, P < 0⋅001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference −9⋅4 (95 per cent c.i. −11⋅9 to −6⋅9) per cent; P < 0⋅001), but the relationship was reversed in low-HDI countries (+12⋅1 (+7⋅0 to +17⋅3) per cent; P < 0⋅001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0⋅60, 0⋅50 to 0⋅73; P < 0⋅001). The greatest absolute benefit was seen for emergency surgery in low-and middle-HDI countries. Conclusion: Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries

    Effects of alirocumab on types of myocardial infarction: insights from the ODYSSEY OUTCOMES trial

    Get PDF
    Aims  The third Universal Definition of Myocardial Infarction (MI) Task Force classified MIs into five types: Type 1, spontaneous; Type 2, related to oxygen supply/demand imbalance; Type 3, fatal without ascertainment of cardiac biomarkers; Type 4, related to percutaneous coronary intervention; and Type 5, related to coronary artery bypass surgery. Low-density lipoprotein cholesterol (LDL-C) reduction with statins and proprotein convertase subtilisin–kexin Type 9 (PCSK9) inhibitors reduces risk of MI, but less is known about effects on types of MI. ODYSSEY OUTCOMES compared the PCSK9 inhibitor alirocumab with placebo in 18 924 patients with recent acute coronary syndrome (ACS) and elevated LDL-C (≥1.8 mmol/L) despite intensive statin therapy. In a pre-specified analysis, we assessed the effects of alirocumab on types of MI. Methods and results  Median follow-up was 2.8 years. Myocardial infarction types were prospectively adjudicated and classified. Of 1860 total MIs, 1223 (65.8%) were adjudicated as Type 1, 386 (20.8%) as Type 2, and 244 (13.1%) as Type 4. Few events were Type 3 (n = 2) or Type 5 (n = 5). Alirocumab reduced first MIs [hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77–0.95; P = 0.003], with reductions in both Type 1 (HR 0.87, 95% CI 0.77–0.99; P = 0.032) and Type 2 (0.77, 0.61–0.97; P = 0.025), but not Type 4 MI. Conclusion  After ACS, alirocumab added to intensive statin therapy favourably impacted on Type 1 and 2 MIs. The data indicate for the first time that a lipid-lowering therapy can attenuate the risk of Type 2 MI. Low-density lipoprotein cholesterol reduction below levels achievable with statins is an effective preventive strategy for both MI types.For complete list of authors see http://dx.doi.org/10.1093/eurheartj/ehz299</p

    Measurement of the inelastic proton-proton cross section at root s=7 TeV

    Get PDF
    A measurement is presented of the inelastic proton-proton cross section at a centre-of-mass energy of root s = 7 TeV. Using the CMS detector at the LHC, the inelastic cross section is measured through two independent methods based on information from (i) forward calorimetry (for pseudorapidity 3 200 MeV/c. The measurements cover a large fraction of the inelastic cross section for particle production over about nine units of pseudorapidity and down to small transverse momenta. The results are compared with those of other experiments, and with models used to describe high-energy hadronic interactions. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved
    corecore