Search results for "PRESSURE"
showing 10 items of 4493 documents
Ultra high performance liquid chromatography-time-of-flight high resolution mass spectrometry in the analysis of hexabromocyclododecane diastereomers…
2014
An efficient ultra high performance liquid chromatography (UHPLC)-time-of-flight high resolution mass spectrometry (TOF-HRMS) method was elaborated for the determination of hexabromocyclododecane (HBCD) diastereomers in fish samples and compared against UHPLC-Orbitrap-HRMS and UHPLC-triple quadrupole (QqQ) tandem MS (MS/MS) techniques. The TOF-HRMS analyzer was operated at high resolution (>10000 full width at half maximum (FWHM)) with scanning the m/z range from 600 to 700, to achieve picogram quantitation limits. The effects of various operational parameters on the instrumental response were systematically investigated. Evaluation of the influence of sample clean-up procedure steps on sig…
High-pressure and high-temperature X-ray diffraction studies of scheelite BaWO4
2009
International audience; We carried out high-pressure (HP) and high-temperature (HT) in situ ADXRD synchrotron measurements in barium tungstate (BaWO4 ) up to 7.5 GPa and 800 K. Coexistence of the scheelite and fergusonite structures was found beyond 7 GPa, both at room temperature and HT, suggesting a polymorphism zone in the P –T phase diagram. The experiments are complemented by thermodynamic calculations within the quasi-harmonic approximation. At ambient pressure, a volume thermal expansivity of 9.5 × 10− 6 K−1 was obtained for scheelite BaWO4 . At HP, the thermal expansivity of the fergusonite doubles that of scheelite. Theoretical equation of state curves at HP and HT are also present…
The referral centers for the diagnosis and treatment of hypertension in adolescents
2015
Primary hypertension in adolescence was felt to be quite rare. However, the worldwide childhood obesity epidemic has had a profound impact on the frequency of high blood pressure (BP) with the result that primary hypertension should now be viewed as one of the most common health conditions in the young (estimated prevalence 1–5%). Therefore, current guidelines recommend that all children and adolescents seen in a medical setting should have their BP measured. The availability of BP tables with normal BP percentiles for age, sex and height has improved BP values classification. Studies conducted at referral clinics for evaluation of hypertension have indicated that as many as 30 to 40% of ad…
Application of C1-Esterase Inhibitor During Reperfusion of Ischemic Myocardium
2001
Background—Complement activation during reperfusion of ischemic myocardium augments myocardial injury, and complement inhibition with C1-esterase inhibitor (C1-INH) at the time of reperfusion exerts marked cardioprotective effects in experimental studies. Application of C1-INH in newborns, however, was recently reported to have dangerous and even lethal side effects. This study addresses the essential role of dosage in studies using C1-INH.Methods and Results—Cardioprotection by C1-INH was examined in a pig model with 60 minutes of coronary occlusion followed by 120 minutes of reperfusion. C1-INH was administered intravenously 5 to 10 minutes before coronary reperfusion without heparin at a…
Optical and Acoustic Vibrations Confined in Anatase TiO2 Nanoparticles under High-Pressure
2014
International audience; The effect of an applied high pressure on the optical and acoustic vibrations of small anatase TiO2 nanoparticles is studied using Raman scattering. All the Raman peaks show a significant variation of their frequency with pressure, except for the low-frequency peak which is due to acoustic vibrations confined in the nanoparticles. These variations (or lack thereof) are compared to first-principles calculations of the stiffness tensor and phonons of bulk anatase TiO2 as a function of pressure. In particular, the variation of the shape of the low-frequency peak is explained by the increase of the elastic anisotropy of anatase TiO2 as pressure is increased.
Anesthetic management of a patient diagnosed with CADASIL (cerebral arteriopathy, autosomal dominant, with subcortical infarcts and leukoencephalopat…
2011
CADASIL (cerebral arteriopathy, autosomal dominant, with subcortical infarcts and leu-koencephalopathy) is an infrequent inherited disease that could have anesthetic implica-tions. However these have rarely been reported. We present a male patient previously diagnosed with CADASIL, who had suffered an ischemic vascular cerebral accident with a MRI compatible with leukoencephalopathy, and who was dependent for daily activities, and sustained dementia, mood alterations, apathy, and urine incontinence. He had famil-ial antecedents of psychiatric symptoms and ischemic stroke events in several relatives including his father, two brothers and one sister. He was scheduled for arthrodesis of the le…
Circulatory Effects of Peridural Block
1972
High peridural analgesia was studied in 20 volunteers in whom peridural block was achieved before and after removal of 10 ml/kg blood to simulate mild acute hemorrhage. One group was given 2 per cent lidocaine containing 1:200,000 epinephrine, while in another group lidocainc alone was used. The gro
Endothelial Leptin Receptor Deletion Promotes Cardiac Autophagy and Angiogenesis Following Pressure Overload by Suppressing Akt/mTOR Signaling.
2019
Background: Cardiac remodeling is modulated by overnutrition or starvation. The adipokine leptin mediates energy balance between adipose tissue and brain. Leptin and its receptors are expressed in the heart. Methods and Results: To examine the importance of endothelial leptin signaling in cardiac hypertrophy, transverse aortic constriction was used in mice with inducible endothelium-specific deletion of leptin receptors (End.LepR-KO) or littermate controls (End.LepR-WT). End.LepR-KO was associated with improved left ventricular function (fractional shortening, 28.4% versus 18.8%; P =0.0114), reduced left ventricular dilation (end-systolic inner left ventricular diameter, 3.59 versus 4.08 m…
Effects of ACE-Inhibitors and Angiotensin Receptor Blockers on Inflammation
2011
The role of inflammation in cardiovascular disease and in hypertensive disease above all, is complex. Several studies confirm that activation of renin-angiotensin-aldosterone system (RAAS), through increase in the production of angiotensin II (Ang II), is closely related to local vascular inflammation. Over the BP lowering effects of anti-hypertensive treatments, several ancillary effects for every class may be found, distinguishing the various drugs from one another. Given the pro-inflammatory effects of Ang II and aldosterone, agents that interfere with the components of RAAS, such as ACE inhibitors, Angiotensin Receptor Blockers (ARBs), and mineralocorticoid receptor antagonists (spirono…
Probing mechanical quantum coherence with an ultracold-atom meter
2011
We propose a scheme to probe quantum coherence in the state of a nano-cantilever based on its magnetic coupling (mediated by a magnetic tip) with a spinor Bose Einstein condensate (BEC). By mapping the BEC into a rotor, its coupling with the cantilever results in a gyroscopic motion whose properties depend on the state of the cantilever: the dynamics of one of the components of the rotor angular momentum turns out to be strictly related to the presence of quantum coherence in the state of the cantilever. We also suggest a detection scheme relying on Faraday rotation, which produces only a very small back-action on the BEC and it is thus suitable for a continuous detection of the cantilever'…