263 research outputs found
Efficacy of antiemetic therapy in patients undergoing laparoscopic cholecystectomy
AbstractIntroductionA high incidence of postoperative nausea and vomiting has been observed in patients undergoing laparoscopic cholecystectomy (20â40%). This causes an increase in patient discomfort, a delay in recovery, and an increase in hospital stay.ObjectiveCompare the efficacy of ondansetron plus metoclopramide and ondansetron alone in the control of postoperative nausea and vomiting in patients undergoing laparoscopic cholecystectomy.Material and methodsA comparative, prospective, experimental, longitudinal double blind study was performed with 30 patients programmed for laparoscopic cholecystectomy. The Apfel score was applied postoperatively. Patients were divided into two groups with 15 participants. Metoclopramide 10mg and ondansetron 4mg were administered in the first Group (A), and ondansetron 4mg in the second Group (B), after induction of anesthesia. Nausea and vomiting were evaluated for 24h postoperatively using a Likert scale.ResultsOf the patients who presented nausea, the condition was mild. The patient who presented vomiting, vomited only once. Neither group required rescue drugs. Regarding the Apfel score, there was no correlation between the percentage of stratified risk and the patients who presented postoperative nausea and vomiting.ConclusionsNo statistically significant difference was observed between ondansetron plus metoclopramide and ondansetron alone in patients subjected to laparoscopic cholecystectomy
Mixed ice accretion on aircraft wings
Ice accretion is a problematic natural phenomenon that an effects a wide range of engineering applications including power cables, radio masts and wind turbines. Accretion on aircraft wings occurs when supercooled water droplets freeze instantaneously on impact to form rime ice or runback as water along the wing to form glaze ice. Most models to date have ignored the accretion of mixed ice, which is a combination of rime and glaze. A parameter we term the `freezing fraction', is defined as the fraction of a supercooled droplet that freezes on impact with the top surface of the accretion ice to explore the concept of mixed ice accretion. Additionally we consider different `packing densities' of rime ice, mimicking the different bulk rime densities observed in nature. Ice accretion is considered in four stages: rime, primary mixed, secondary mixed and glaze ice. Predictions match with existing models and experimental data in the limiting rime and glaze cases. The mixed ice formulation consequently however provides additional insight into the composition of the overall ice structure, which ultimately influences adhesion and ice thickness; and shows that for similar atmospheric parameter ranges, this simple mixed ice description leads to very different accretion rates. A simple one-dimensional energy balance was solved to show how this freezing fraction parameter increases with decrease in atmospheric temperature, with lower freezing fraction promoting glaze ice accretion
NADPH Oxidase 5 Is a ProâContractile Nox Isoform and a Point of CrossâTalk for Calcium and Redox SignalingâImplications in Vascular Function
Background
NADPH Oxidase 5 (Nox5) is a calciumâsensitive superoxideâgenerating Nox. It is present in lower forms and higher mammals, but not in rodents. Nox5 is expressed in vascular cells, but the functional significance remains elusive. Given that contraction is controlled by calcium and reactive oxygen species, both associated with Nox5, we questioned the role of Nox5 in proâcontractile signaling and vascular function.
Methods and Results
Transgenic mice expressing human Nox5 in a vascular smooth muscle cellâspecific manner (Nox5 mice) and Rhodnius prolixus, an arthropod model that expresses Nox5 endogenoulsy, were studied. Reactive oxygen species generation was increased systemically and in the vasculature and heart in Nox5 mice. In Nox5âexpressing mice, agonistâinduced vasoconstriction was exaggerated and endotheliumâdependent vasorelaxation was impaired. Vascular structural and mechanical properties were not influenced by Nox5. Vascular contractile responses in Nox5 mice were normalized by Nâacetylcysteine and inhibitors of calcium channels, calmodulin, and endoplasmic reticulum ryanodine receptors, but not by GKT137831 (Nox1/4 inhibitor). At the cellular level, vascular changes in Nox5 mice were associated with increased vascular smooth muscle cell [Ca2+]i, increased reactive oxygen species and nitrotyrosine levels, and hyperphosphorylation of proâcontractile signaling molecules MLC20 (myosin light chain 20) and MYPT1 (myosin phosphatase target subunit 1). Blood pressure was similar in wildâtype and Nox5 mice. Nox5 did not amplify angiotensin II effects. In R. prolixus, gastrointestinal smooth muscle contraction was blunted by Nox5 silencing, but not by VAS2870 (Nox1/2/4 inhibitor).
Conclusions
Nox5 is a proâcontractile Nox isoform important in redoxâsensitive contraction. This involves calciumâcalmodulin and endoplasmic reticulumâregulated mechanisms. Our findings define a novel function for vascular Nox5, linking calcium and reactive oxygen species to the proâcontractile molecular machinery in vascular smooth muscle cells
NADPH oxidase 5 is a proâcontractile Nox isoform and a point of crossâtalk for calcium and redox signalingâimplications in vascular function
Background:
NADPH Oxidase 5 (Nox5) is a calciumâsensitive superoxideâgenerating Nox. It is present in lower forms and higher mammals, but not in rodents. Nox5 is expressed in vascular cells, but the functional significance remains elusive. Given that contraction is controlled by calcium and reactive oxygen species, both associated with Nox5, we questioned the role of Nox5 in proâcontractile signaling and vascular function.
Methods and Results:
Transgenic mice expressing human Nox5 in a vascular smooth muscle cellâspecific manner (Nox5 mice) and Rhodnius prolixus, an arthropod model that expresses Nox5 endogenoulsy, were studied. Reactive oxygen species generation was increased systemically and in the vasculature and heart in Nox5 mice. In Nox5âexpressing mice, agonistâinduced vasoconstriction was exaggerated and endotheliumâdependent vasorelaxation was impaired. Vascular structural and mechanical properties were not influenced by Nox5. Vascular contractile responses in Nox5 mice were normalized by Nâacetylcysteine and inhibitors of calcium channels, calmodulin, and endoplasmic reticulum ryanodine receptors, but not by GKT137831 (Nox1/4 inhibitor). At the cellular level, vascular changes in Nox5 mice were associated with increased vascular smooth muscle cell [Ca2+]i, increased reactive oxygen species and nitrotyrosine levels, and hyperphosphorylation of proâcontractile signaling molecules MLC20 (myosin light chain 20) and MYPT1 (myosin phosphatase target subunit 1). Blood pressure was similar in wildâtype and Nox5 mice. Nox5 did not amplify angiotensin II effects. In R. prolixus, gastrointestinal smooth muscle contraction was blunted by Nox5 silencing, but not by VAS2870 (Nox1/2/4 inhibitor).
Conclusions:
Nox5 is a proâcontractile Nox isoform important in redoxâsensitive contraction. This involves calciumâcalmodulin and endoplasmic reticulumâregulated mechanisms. Our findings define a novel function for vascular Nox5, linking calcium and reactive oxygen species to the proâcontractile molecular machinery in vascular smooth muscle cells
Search for CP violation in decays
A model-independent search for direct CP violation in the Cabibbo suppressed
decay in a sample of approximately 370,000 decays is
carried out. The data were collected by the LHCb experiment in 2010 and
correspond to an integrated luminosity of 35 pb. The normalized Dalitz
plot distributions for and are compared using four different
binning schemes that are sensitive to different manifestations of CP violation.
No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.
Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)
The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma
and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a
centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The
value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08
^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical,
the second systematic and the third is associated to the ratio of fragmentation
fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/-
0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be
(3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table
Opposite-side flavour tagging of B mesons at the LHCb experiment
The calibration and performance of the oppositeside
flavour tagging algorithms used for the measurements
of time-dependent asymmetries at the LHCb experiment
are described. The algorithms have been developed using
simulated events and optimized and calibrated with
B
+ âJ/ÏK
+, B0 âJ/ÏK
â0 and B0 âD
ââ
Ό
+
ΜΌ decay
modes with 0.37 fbâ1 of data collected in pp collisions
at
â
s = 7 TeV during the 2011 physics run. The oppositeside
tagging power is determined in the B
+ â J/ÏK
+
channel to be (2.10 ± 0.08 ± 0.24) %, where the first uncertainty
is statistical and the second is systematic
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