1,032 research outputs found
Adaptive data acquisition multiplexing system and method
A reconfigurable telemetry multiplexer is described which includes a monitor-terminal and a plurality of remote terminals. The remote terminals each include signal conditioning for a plurality of sensors for measuring parameters which are converted by an analog to digital converter. CPU's in the remote terminals store instructions for prompting system configuration and reconfiguration commands. The measurements, instructions, and the terminal's present configuration and status data are transmitted to the monitor-terminal and displayed. In response to menu-driven prompts generated and displayed at the monitor-terminal, data generation request commands, status and health commands, and the like are input at the monitor-terminal and transmitted to the remote terminals. The CPU in each remote terminal receives the various commands, stores them in electrically alterable memory, and reacts in accordance with the commands to reconfigure a plurality of aspects of the system. The CPU in each terminal also generates parameter measurements, status and health signals, and transmits these signals of the respective terminals to the monitor-terminal for low data rate operator viewing and to higher rate external transmission/monitor equipment. Reconfiguration may be in real time during the general period of parameter measurement acquisition, and may include alteration of the gain, automatic gain rescaling, bias, and or sampling rates associated with one or more of the parameter measurements made by the remote terminals
Antagonism of neuromuscular blockade but not muscle relaxation affects depth of anaesthesia
Background. Conflicting effects of neuromuscular blocking drugs and anticholinesterases on depth of anaesthesia have been reported. Therefore we evaluated the effect of atracurium and neostigmine on bispectral index (BIS) and middle-latency auditory evoked potentials (AAI). Methods. We studied 40 patients (ASA I-II) aged 18-69 yr. General anaesthesia consisted of propofol and remifentanil by target-controlled infusion and neuromuscular function was monitored by electromyography. When BIS reached stable values, patients were randomly assigned to one of two groups. Group 1 received atracurium 0.4 mg kg−1 and, 5 min later, the same volume of NaCl 0.9%; group 2 received saline first and then atracurium. When the first twitch of a train of four reached 10% of control intensity, patients were again randomized: one group (N) received neostigmine 0.04 mg kg−1 and glycopyrrolate 0.01 mg kg−1, and the control group (G) received only glycopyrrolate. Results. Injection of atracurium or NaCl 0.9% had no effect on BIS or AAI. After neostigmine-glycopyrrolate, BIS and AAI increased significantly (mean maximal change of BIS 7.1 [sd 7.5], P<0.001; mean maximal change of AAI 9.7 [10.5], P<0.001). When glycopyrrolate was injected alone BIS and AAI also increased (mean maximal change of BIS 2.2 [3.4], P=0.008; mean maximal change of AAI 3.5 [5.7], P=0.012), but this increase was significantly less than in group N (P=0.012 for BIS; P=0.027 for AAI). Conclusion. These data suggest that neostigmine alters the state of propofol-remifentanil anaesthesia and may enhance recover
Synchnonization, zero-resistance states and rotating Wigner crystal
We show that rotational angles of electrons moving in two dimensions (2D) in
a perpendicular magnetic field can be synchronized by an external microwave
field which frequency is close to the Larmor frequency. The synchronization
eliminates collisions between electrons and thus creates a regime with zero
diffusion corresponding to the zero-resistance states observed in experiments
with high mobility 2D electron gas (2DEG). For long range Coulomb interactions
electrons form a rotating hexagonal Wigner crystal. Possible relevance of this
effect for planetary rings is discussed.Comment: 4 pages, 4 fig
Lawyer Advertising in the Electronic Age
The April 5, 2001 symposium consisted of an informal roundtable discussion for the presenters from 2:30-4:30 p.m., followed by a public evening program, from 6:00-8:30 p.m., which featured a role-playing portrayal of a mock disciplinary proceeding about a dispute over lawyer advertising.
Participants in the roundtable discussion were: Ronald D. Rotunda, the Albert E. Jenner, Jr. Professor of Law at the University of Illinois College of Law; Louise L. Hill, Professor of Law at the Widener University School of Law; and William Hornsby, Legal Counsel to the American Bar Association, Commission on Responsibility in Client Development.
The Moot Court program included William Hornsby, Legal Counsel to the American Bar Association, as prosecutor from the state bar\u27s disciplinary council; Tom Spahn as defense lawyer for the firm; Ted Allen as chair of disciplinary council; and Louise L. Hill, Ronald Rotunda, and William Spruill as disciplinary council members. Rodney A. Smolla, the George E. Allen Chair in Law at the University of Richmond School of Law served as program coordinator and moderator
In vitro factor XIII supplementation increases clot firmness in Rotation Thromboelastometry (ROTEM®)
Factor XIII (F XIII) is an essential parameter for final clot stability. The purpose of this study was to determine the impact of the addition of factor (F)XIII on clot stability as assessed by Rotation Thromboelastometry (ROTEM(R)). In 90 intensive care patients ROTEM(R) measurements were performed after in vitro addition of F XIII 0.32 IU, 0.63 IU, 1.25 IU and compared to diluent controls (DC; aqua injectabile) resulting in approximate F XIII concentrations of 150, 300 and 600%. Baseline measurements without any additions were also performed. The following ROTEM(R) parameters were measured in FIBTEM and EXTEM tests: clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF), maximum lysis (ML), maximum clot elasticity (MCE) and a-angle (aA). Additionally, laboratory values for FXIII, fibrinogen (FBG), platelets and haematocrit were contemporaneously determined. In the perioperative patient population mean FBG concentration was elevated at 5.2 g/l and mean FXIII concentration was low at 62%. The addition of FXIII led to a FBG concentration-dependent increase in MCF both in FIBTEM and EXTEM. Mean increases in MCF (FXIII vs. DC) of approximately 7 mm and 6 mm were observed in FIBTEM and EXTEM, respectively. F XIII addition also led to decreased CFT, increased aA, and reduced ML in FIBTEM and EXTEM. In vitro supplementation of FXIII to supraphysiologic levels increases maximum clot firmness, accelerates clot formation and increases clot stability in EXTEM and FIBTEM as assayed by ROTEM(R) in perioperative patients with high fibrinogen and low FXIII levels
A model of ballistic aggregation and fragmentation
A simple model of ballistic aggregation and fragmentation is proposed. The
model is characterized by two energy thresholds, Eagg and Efrag, which
demarcate different types of impacts: If the kinetic energy of the relative
motion of a colliding pair is smaller than Eagg or larger than Efrag, particles
respectively merge or break; otherwise they rebound. We assume that particles
are formed from monomers which cannot split any further and that in a
collision-induced fragmentation the larger particle splits into two fragments.
We start from the Boltzmann equation for the mass-velocity distribution
function and derive Smoluchowski-like equations for concentrations of particles
of different mass. We analyze these equations analytically, solve them
numerically and perform Monte Carlo simulations. When aggregation and
fragmentation energy thresholds do not depend on the masses of the colliding
particles, the model becomes analytically tractable. In this case we show the
emergence of the two types of behavior: the regime of unlimited cluster growth
arises when fragmentation is (relatively) weak and the relaxation towards a
steady state occurs when fragmentation prevails. In a model with mass-dependent
Eagg and Efrag the evolution with a cross-over from one of the regimes to
another has been detected
Preconditioning with sevoflurane decreases PECAM-1 expression and improves one-year cardiovascular outcome in coronary artery bypass graft surgery
Background. Cardiac preconditioning is thought to be involved in the observed decreased coronary artery reocclusion rate in patients with angina preceding myocardial infarction. We prospectively examined whether preconditioning by sevoflurane would decrease late cardiac events in patients undergoing coronary artery bypass graft (CABG) surgery. Methods. Seventy-two patients scheduled for elective CABG surgery were randomized to preconditioning by sevoflurane (10 min at 4 vol%) or placebo. For all patients, follow-up of adverse cardiac events was obtained 6 and 12 months after surgery. Transcript levels for platelet-endothelial cell adhesion molecule-1 (PECAM-1/CD31), catalase and heat shock protein 70 (Hsp70) were determined in atrial biopsies after sevoflurane preconditioning. Results. Pharmacological preconditioning by sevoflurane reduced the incidence of late cardiac events during the first year after CABG surgery (sevoflurane 3% vs 17% in the placebo group, log-rank test, P=0.038). One patient in the sevoflurane group and three patients in the placebo group experienced new episodes of congestive heart failure and three additional patients had coronary artery reocclusion. Perioperative peak concentrations for myocardial injury markers were higher in patients with subsequent late cardiac events [NTproBNP, 9031 (4125) vs 3049 (1906) ng litre−1, P<0.001; cTnT, 1.31 (0.88) vs 0.46 (0.29) µg litre−1, P<0.001]. Transcript levels were reduced for PECAM-1 and increased for catalase but unchanged for Hsp70 in atrial biopsies after sevoflurane preconditioning. Conclusions. This prospective randomized clinical study provides evidence of a protective role for pharmacological preconditioning by sevoflurane in late cardiac events in CABG patients, which may be related to favourable transcriptional changes in pro- and antiprotective protein
Relative concentrations of haemostatic factors and cytokines in solvent/detergent-treated and fresh-frozen plasma
Background Indications, efficacy, and safety of plasma products are highly debated. We compared the concentrations of haemostatic proteins and cytokines in solvent/detergent-treated plasma (SDP) and fresh-frozen plasma (FFP). Methods Concentrations of the following parameters were measured in 25 SDP and FFP samples: fibrinogen (FBG), factor (F) II, F V, F VII, F VIII, F IX, F X, F XIII, von Willebrand factor (vWF), D-Dimers, ADAMTS-13 protease, tumour necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, IL-8, and IL-10. Results Mean FBG concentrations in SDP and FFP were similar, but in FFP, the range was larger than in SDP (P<0.01). Mean F II, F VII, F VIII, F IX, and F XIII levels did not differ significantly. Higher concentrations of F V (P<0.01), F X (P<0.05), vWF (P<0.01), and ADAMTS-13 (P<0.01) were found in FFP. With the exception of F VIII and F IX, the range of concentrations for all of these factors was smaller (P<0.05) in SDP than in FFP. Concentrations of TNF-α, IL-8, and IL-10 (all P<0.01) were higher in FFP than in SDP, again with a higher variability and thus larger ranges (P<0.01). Conclusions Coagulation factor content is similar for SDP and FFP, with notable exceptions of less F V, vWF, and ADAMTS-13 in SDP. Cytokine concentrations (TNFα, IL-8, and IL-10) were significantly higher in FFP. The clinical relevance of these findings needs to be established in outcome studie
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