54 research outputs found

    Repeated bedside echocardiography in children with respiratory failure

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to verify the benefits and limitations of repeated bedside echocardiographic examinations in children during mechanical ventilation. For the purposes of this study, we selected the data of over a time period from 2006 to 2010.</p> <p>Methods</p> <p>A total of 235 children, average age 3.21 (SD 1.32) years were included into the study and divided into etiopathogenic groups. High-risk groups comprised: Acute lung injury and acute respiratory distress syndrome (ALI/ARDS), return of spontaneous circulation after cardiopulmonary resuscitation (ROSC), bronchopulmonary dysplasia (BPD), cardiomyopathy (CMP) and cardiopulmonary disease (CPD). Transthoracic echocardiography was carried out during mechanical ventilation. The following data were collated for statistical evaluation: right and left ventricle myocardial performance indices (RV MPI; LV MPI), left ventricle shortening fraction (SF), cardiac output (CO), and the mitral valve ratio of peak velocity of early wave (E) to the peak velocity of active wave (A) as E/A ratio. The data was processed after a period of recovery, i.e. one hour after the introduction of invasive lines (time-1) and after 72 hours of comprehensive treatment (time-2). The overall development of parameters over time was compared within groups and between groups using the distribution-free Wilcoxons and two-way ANOVA tests.</p> <p>Results</p> <p>A total of 870 echocardiographic examinations were performed. At time-1 higher average values of RV MPI (0.34, SD 0.01 vs. 0.21, SD 0.01; p < 0.001) were found in all groups compared with reference values. Left ventricular load in the high-risk groups was expressed by a higher LV MPI (0.39, SD 0.13 vs. 0.29, SD 0.02; p < 0.01) and lower E/A ratio (0.95, SD 0.36 vs. 1.36, SD 0.64; p < 0.001), SF (0.37, SD 0.11 vs. 0.47, SD 0.02; p < 0.01) and CO (1.95, SD 0.37 vs. 2.94, SD 1.03; p < 0.01). At time-2 RV MPI were lower (0.25, SD 0.02 vs. 0.34, SD 0.01; p < 0.001), but remained higher compared with reference values (0.25, SD 0.02 vs. 0.21, SD 0.01; p < 0.05). Other parameters in high-risk groups were improved, but remained insignificantly different compared with reference values.</p> <p>Conclusion</p> <p>Echocardiography complements standard monitoring of valuable information regarding cardiac load in real time. Chest excursion during mechanical ventilation does not reduce the quality of the acquired data.</p

    Development of crystalline inclusions (“ergosterol crystals”) in Neurospora crassa

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    Development of crystalline inclusions (“ergosterol crystals”) in “snowflake”, a morphological mutant of Neurospora crassa has been examined. The inclusions which arise in membranebound organelles appear as electron dense deposits, increase in size, and occupy nearly all the space within the organelle at maturity. The presence of catalase activity in the organelle was not detected using cytochemical procedures employing diaminobenzidine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41731/1/709_2005_Article_BF01275681.pd

    Bronchopulmonary dysplasia: clinical aspects and preventive and therapeutic strategies

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    Abstract Background Bronchopulmonary dysplasia (BPD) is the result of a complex process in which several prenatal and/or postnatal factors interfere with lower respiratory tract development, leading to a severe, lifelong disease. In this review, what is presently known regarding BPD pathogenesis, its impact on long-term pulmonary morbidity and mortality and the available preventive and therapeutic strategies are discussed. Main body Bronchopulmonary dysplasia is associated with persistent lung impairment later in life, significantly impacting health services because subjects with BPD have, in most cases, frequent respiratory diseases and reductions in quality of life and life expectancy. Prematurity per se is associated with an increased risk of long-term lung problems. However, in children with BPD, impairment of pulmonary structures and function is even greater, although the characterization of long-term outcomes of BPD is difficult because the adults presently available to study have received outdated treatment. Prenatal and postnatal preventive measures are extremely important to reduce the risk of BPD. Conclusion Bronchopulmonary dysplasia is a respiratory condition that presently occurs in preterm neonates and can lead to chronic respiratory problems. Although knowledge about BPD pathogenesis has significantly increased in recent years, not all of the mechanisms that lead to lung damage are completely understood, which explains why therapeutic approaches that are theoretically effective have been only partly satisfactory or useless and, in some cases, potentially negative. However, prevention of prematurity, systematic use of nonaggressive ventilator measures, avoiding supraphysiologic oxygen exposure and administration of surfactant, caffeine and vitamin A can significantly reduce the risk of BPD development. Cell therapy is the most fascinating new measure to address the lung damage due to BPD. It is desirable that ongoing studies yield positive results to definitively solve a major clinical, social and economic problem

    The complexity of planar Boolean #CSP with complex weights

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    A synthesis of new bidentate pyridines 8a-d, 9, and 10 has been developed, starting from triflate 14, readily available from beta-pinene 11. A copper complex of the pyridine-oxazoline ligands 8a has been found to catalyze asymmetric allylic oxidation of cyclic olefins 36a-c with good conversion rates and acceptable enantioselectivity (&lt;= 67% ee). The imidazolium salt 10 has been identified as a precursor of the corresponding N,N'-unsymmetrical N-heterocyclic carbene ligand, whose complex with palladium catalyzed the intramolecular amide enolate alpha-arylation leading to oxindole 45 in excellent yield but with low enantioselectivity.

    Average Orientation of a Molecular Rotor Embedded in a Langmuir–Blodgett Monolayer

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    A molecular rotor in which a naphthalene rotator is attached through a silicon atom to three fatty acid chains has been synthesized, and Langmuir–Blodgett techniques were used to deposit on silica surfaces monolayers of its calcium salt, both neat and diluted with stearic acid salts. The monolayer films have been characterized by ellipsometry and Fourier transform infrared (FT-IR) grazing-incidence attenuated total internal reflection (GATR) spectroscopy on Si-SiO<sub>2</sub> and by UV–vis absorption spectroscopy on SiO<sub>2</sub>. The measurements were combined with calculations of the electronic (INDO/S) and vibrational (DFT) transition moment directions to deduce the average orientation of the rotor molecules, including the naphthalene ring, relative to the surface. In both neat and mixed films, the naphthalene ring is found to preferentially tilt toward the surface, enough that its rotation is most likely hindered. A comparable picture was obtained from molecular mechanics calculations on a mixed film of the naphthalene rotor and stearic acid

    Fast Photodriven Electron Spin Coherence Transfer: A Quantum Gate Based on a Spin Exchange <i>J</i>‑Jump

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    Photoexcitation of the electron donor (D) within a linear, covalent donor–acceptor–acceptor molecule (D-A<sub>1</sub>-A<sub>2</sub>) in which A<sub>1</sub> = A<sub>2</sub> results in sub-nanosecond formation of a spin-coherent singlet radical ion pair state, <sup>1</sup>(D<sup>+•</sup>-A<sub>1</sub><sup>–•</sup>-A<sub>2</sub>), for which the spin–spin exchange interaction is large: 2<i>J</i> = 79 ± 1 mT. Subsequent laser excitation of A<sub>1</sub><sup>–•</sup> during the lifetime of <sup>1</sup>(D<sup>+•</sup>-A<sub>1</sub><sup>–•</sup>-A<sub>2</sub>) rapidly produces <sup>1</sup>(D<sup>+•</sup>-A<sub>1</sub>-A<sub>2</sub><sup>–•</sup>), which abruptly decreases 2<i>J</i> 3600-fold. Subsequent coherent spin evolution mixes <sup>1</sup>(D<sup>+•</sup>-A<sub>1</sub>-A<sub>2</sub><sup>–•</sup>) with <sup>3</sup>(D<sup>+•</sup>-A<sub>1</sub>-A<sub>2</sub><sup>–•</sup>), resulting in mixed states which display transient spin-polarized EPR transitions characteristic of a spin-correlated radical ion pair. These photodriven <i>J</i>-jump experiments show that it is possible to use fast laser pulses to transfer electron spin coherence between organic radical ion pairs and observe the results using an essentially background-free time-resolved EPR experiment
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