735 resultados para Transfusió de sang


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Rifampicin, discovered more than 50 years ago, represents the last novel class of antibiotics introduced for the first-line treatment of tuberculosis. Drugs in this class form part of a 6-month regimen that is ineffective against MDR and XDR TB, and incompatible with many antiretroviral drugs. Investments in R&D strategies have increased substantially in the last decades. However, the number of new drugs approved by drug regulatory agencies worldwide does not increase correspondingly. Ruthenium complexes (SCAR) have been tested in our laboratory and showed promising activity against Mycobacterium tuberculosis. These complexes showed up to 150 times higher activity against MTB than its organic molecule without the metal (free ligand), with low cytotoxicity and high selectivity. In this study, promising results inspired us to seek a better understanding of the biological activity of these complexes. The in vitro biological results obtained with the SCAR compounds were extremely promising, comparable to or better than those for first-line drugs and drugs in development. Moreover, SCAR 1 and 4, which presented low acute toxicity, were assessed by Ames test, and results demonstrated absence of mutagenicity. © 2013 Pavan et al.

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Delayed feedback (DF) control is a well-established technique to suppress single frequency vibration of a non-minimum phase system. Modal control is also a well-established technique to control multiple vibration modes of a minimum phase system. In this paper these techniques are combined to simultaneously suppress multiple vibration modes of a non-minimum phase system involving a small time delay. The control approach is called delayed resonant feedback (DRF) where each modal controller consists of a modal filter to extract the target mode signal from the vibration response, and a phase compensator to account for the phase delay of the mode. The methodology is first discussed using a single mode system. A multi-mode system is then studied and experimental results are presented to demonstrate the efficacy of the control approach for two modes of a beam. It is shown that the system behaves as if each mode under control has a dynamic vibration absorber attached to it, even though the actuator and the sensor are not collocated and there is a time delay in the control system. © 2013 IOP Publishing Ltd.

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Incluye Bibliografía

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This paper describes an experimental study into the vibration control of a servo system comprising a servo motor and a flexible manipulator. Two modes of the system are controlled by using the servo motor and an accelerometer attached to the tip of the flexible manipulator. The control system is thus non-collocated. It consists of two electrical dynamic absorbers, each of which consists of a modal filter and, in case of an out-of-phase mode, a phase inverter. The experimental results show that each absorber acts as a mechanical dynamic vibration absorber attached to each mode and significantly reduces the settling time for the system response to a step input.

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This paper is concerned with what a source precisely sees when it drives a receiver such as a continuous structural object. An equivalent lumped element system consisting of masses, springs and dampers is developed to visually represent the operational structural dynamics of a single-input structure at the driving point. The development is solely based on the mobility model of the driving point response. The mobility model is mathematically inverted to give the impedance model that is suitable for lumped element modeling. The two types of structures studied are unconstrained inertial objects and constrained resilient objects. The lumped element systems presented suggest a new view to dynamics that a single-input flexible structure in operation can be decomposed into the two subsystems: a base system of single degree of freedom (or of a mass for an inertial object) whose mass is in contact with the source and an appendage system consisting of a series of oscillators each of which is attached to the base mass. The driving point response is a result of the coupling between the two subsystems. (C) 2014 Elsevier Ltd. All rights reserved.

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Bioactive components in rice vary depending on the variety and growing condition. Fat-soluble components such as gamma-oryzanol, tocopherols, tocotrienols, carotenoids, and fatty acids were analyzed in brown, sugary brown, red, and black rice varieties using established high-performance liquid chromatography (HPLC) and GC methodologies. In addition, these colored rice varieties were further analyzed using a high-resolution liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) (LTQ-Orbitrap XL) to identify the [M-H](-) ions of gamma-oryzanol, ranging from m/z 573.3949 to 617.4211. The highest content of tocopherols (alpha-, 1.5; gamma-, 0.5 mg/100 g) and carotenoids (lutein 244; trans-beta carotene 25 mu g/100 g) were observed in black rice; tocotrienols (alpha-, 0.07; gamma-, 0.14 mg/100 g) in red rice, and gamma-oryzanol (115 mg/100 g) in sugary brown rice. In all colored rice varieties, the major fatty acids were palmitic (16:0), oleic (18:1n-9), and linoleic (18:2n-6) acids. When the gamma-oryzanol components were further analyzed by LC-MS/MS, 3, 10, 8, and 8 triterpene alcohols or sterol ferulates were identified in brown, sugary brown, red, and black rice varieties, respectively. Such structural identification can lead to the elucidation of biological function of each component at the molecular level. Consumption of colored rice rich in beneficial bioactive compounds may be a useful dietary strategy for achieving optimal health.

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This paper is concerned with a modeling method that can be used for an experimental identification of a dynamic system. More specifically, an equivalent lumped element system is presented to represent in a unique and exact manner a complete proportional-derivative (PD) controlled servo positioning system having a flexible manipulator. The impedance and mobility approach is used to transform the P and D control gains to an electrical spring and an electrical damper, respectively. The impedance model method is used to transform the flexible manipulator to a coupled system between a single contact mass at the driving position and a series of noncontact masses each of which is connected to the contact mass via a resilient member. This method is applicable whenever the driving point response of such a manipulator is available. Experimental work is presented to support the theory developed.

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This study compared acid-base and biochemical changes and quality of recovery in male cats with experimentally induced urethral obstruction and anesthetized with either propofol or a combination of ketamine and diazepam for urethral catheterization. Ten male cats with urethral obstruction were enrolled for urethral catheterization and anesthetized with either ketamine-diazepam (KD) or propofol (P). Lactated Ringer's solution was administered by intravenous (IV) beginning 15 min before and continuing for 48 h after relief of urethral obstruction. Quality of recovery and time to standing were evaluated. The urethral catheter was maintained to measure urinary output. Hematocrit (Hct), total plasma protein (TPP), albumin, total protein (TP), blood urea nitrogen (BUN), creatinine, pH, bicarbonate (HCO3-), chloride, base excess, anion gap, sodium, potassium, and partial pressure of carbon dioxide in mixed venous blood (pvCO(2)) were measured before urethral obstruction, at start of fluid therapy (0 h), and at subsequent intervals. The quality of recovery and time to standing were respectively 4 and 75 min in the KD group and 5 and 16 min in the P group. The blood urea nitrogen values were increased at 0, 2, and 8 h in both groups. Serum creatinine increased at 0 and 2 h in cats administered KD and at 0, 2, and 8 h in cats receiving P, although the values were above the reference range in both groups until 8 h. Acidosis occurred for up to 2 h in both groups. Acid-base and biochemical stabilization were similar in cats anesthetized with propofol or with ketamine-diazepam. Cats that received propofol recovered much faster, but the ketamine-diazepam combination was shown to be more advantageous when treating uncooperative cats as it can be administered by intramuscular (IM) injection.

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We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.

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The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.

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A study was designed to investigate the molecular epidemiology of extended-spectrum -lactamase (ESBL)-producing Klebsiella pneumoniae isolated in a centralized region over a 10 year period (200009). Molecular characterization was done using isoelectric focusing, PCR and sequencing for bla(CTX-M), bla(TEM) and bla(SHV) genes and plasmid-mediated quinolone resistance determinants. Genetic relatedness was determined with PFGE using XbaI and multilocus sequencing typing. A total of 89 patients with incident infections were identified; the majority presented with hospital-onset urinary tract infections. The absolute number of ESBL-producing isolates remained very low until 2003, increased slightly in 2004, remained stable until 2008 and then in 2009 there was an abrupt increase in the numbers of ESBL producers identified. The majority of K. pneumoniae produced CTX-M-14 and -15, and have replaced SHV-12-producing isolates since 2005. We identified four different major sequence types (STs) among 32 of isolates (i.e. ST17, ST20, and the new ST573 and ST575) and provided insight into their clinical and molecular characteristics. The ST isolates were more likely to produce community-onset infections, were associated with bla(CTX-M) and emerged during the latter part of the study period. ST17 produced CTX-M-15 and SHV-12, and was more likely to be positive for qnrB; ST20 produced CTX-M-14 and was positive for qnrS. The multiresistant ST575 that produced CTX-M-15 appeared in 2009. Our study highlights the importance of molecular epidemiology in providing insight into the emergence, characteristics and distribution of STs among ESBL-producing K. pneumoniae.

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Macrophage ingestion of the yeast Candida albicans requires its recognition by multiple receptors and the activation of diverse signaling programs. Synthesis of the lipid mediator prostaglandin E-2 (PGE(2)) and generation of cyclic adenosine monophosphate (cAMP) also accompany this process. Here, we characterized the mechanisms underlying PGE(2)-mediated inhibition of phagocytosis and filamentous actin (F-actin) polymerization in response to ingestion of C. albicans by alveolar macrophages. PGE(2) suppressed phagocytosis and F-actin formation through the PGE(2) receptors EP2 and EP4, cAMP, and activation of types I and II protein kinase A. Dephosphorylation and activation of the actin depolymerizing factor cofilin-1 were necessary for these inhibitory effects of PGE(2). PGE(2)-dependent activation of cofilin-1 was mediated by the protein phosphatase activity of PTEN (phosphatase and tensin homolog deleted on chromosome 10), with which it directly associated. Because enhanced production of PGE(2) accompanies many immunosuppressed states, the PTEN-dependent pathway described here may contribute to impaired antifungal defenses.