Overnight Operation Research Articles

Outcomes of nonemergency cardiac surgery after overnight operative workload: A statewide experience

ObjectiveCardiac surgeons experience unpredictable overnight operative responsibilities, with variable rest before same-day, first-start scheduled cases. This study evaluated the frequency and associated impact of a surgeon's overnight operative workload on the outcomes of their same-day, first-start operations. MethodsA statewide cardiac surgery quality database was queried for adult cardiac surgical operations between July 1, 2011, and March 1, 2021. Nonemergency, first-start, Society of Thoracic Surgeons predicted risk of mortality operations were stratified by whether or not the surgeon performed an overnight operation that ended after midnight. A generalized mixed effect model was used to evaluate the effect of overnight operations on a Society of Thoracic Surgeons composite outcome (5 major morbidities or operative mortality) of the first-start operation. ResultsOf all first-start operations, 0.4% (239/56,272) had a preceding operation ending after midnight. The Society of Thoracic Surgeons predicted risk of morbidity and mortality was similar for first-start operations whether preceded by an overnight operation or not (overnight operation: 11.3%; no overnight operation: 11.7%, P = .42). Unadjusted rates of the primary outcome were not significantly different after an overnight operation (overnight operation: 13.4%; no overnight operation: 12.3%, P = .59). After adjustment, overnight operations did not significantly impact the risk of major morbidity or mortality for first-start operations (adjusted odds ratio, 1.1, P = .70). ConclusionsFirst-start cardiac operations performed after an overnight operation represent a small subset of all first-start Society of Thoracic Surgeons predicted risk operations. Overnight operations do not significantly influence the risk of major morbidity or mortality of first-start operations, which suggests that surgeons exercise proper judgment in determining appropriate workloads.

Double-Track One-Direction Operation Mode for Overnight Trains on High-Speed Railway

The mileage of China’s high-speed railways is increasing, and trains running only during the day cannot satisfy the need. In the existing train organization and maintenance modes, overnight trains and maintenance constructions strongly interact with each other and are difficult to coordinate. Although some overnight trains run on a high-speed railway (HSR), currently, they are all sunset-departure and sunrise-arrival trains, and none of them depart in the night by passenger’s habits. Only a one-way line is occupied by night, except rendezvous; the opposite direction line resources are idled. According to this feature, a double-track one-direction mode on the HSR was proposed based on the reverse running ability of the train control system to coordinate the train operation and maintenance. A mathematical model was established, and a heuristic algorithm based on simulated annealing was designed. The validity of the model was verified on the section from Xuzhoudong to Xi’anbei of Xuzhou-Lanzhou HSR, as an example. The results showed that 10 pairs of overnight sleeper trains and some freight trains can run, and the maintenance disruption is not less than 180 min. The proposed method can provide a new method to coordinate the overnight operation and maintenance of the HSR and increase the capacity of HSRs.

Photo-Induced Copper-Mediated Acrylate Polymerization in Continuous-Flow Reactors

The synthetic scope of photo-induced copper-mediated polymerization (photoCMP) in continuous-flow reactors is further explored. A series of monomers, namely, methyl (MA), ethyl (EA), n-butyl (nBA), 2-hydroxyethyl (HEA), and di(ethylene glycol) ethyl ether (DEGA) acrylate are investigated, all showing high livingness (dispersity in the range of 1.1 and linear first order kinetics) in the polymerizations and high conversions within 20-min reaction time. Next to the commonly used solvent (dimethyl sulfoxide [DMSO]), also a water—ethanol mixture was used as greener alternative, without any loss in reaction control. Upscaling the reactor from 2 to 16 mL allows for production of over 200 g of high-definition material (3000 g/mol, 1.1 dispersity) in overnight operation (18 h), demonstrating that the photoprocess can be run under very stable conditions even for extended reaction times. Via coupling of two reactors, direct chain extension of copolymers in a single reaction step is also demonstrated.

A compact light source at 461 nm using a periodically poled LiNbO_3 waveguide for strontium magneto-optical trapping

We have developed a compact light source at 461 nm using a single-pass periodically poled LiNbO3 waveguide for second-harmonic (SH) generation. The obtained optical power at 461 nm is 76 mW when the power of the 922-nm fundamental light coupled into the waveguide is 248 mW. Although a narrowing of the phase-matching temperature acceptance bandwidth is observed at a high SH power, stable overnight operation is realized by carefully controlling the device temperature within an uncertainty of 0.01 °C.

A Stand-Alone Monitoring System for Reliable Unattended Operation of a Commercial Preparative LC/MS Purification System

Commercially available preparative liquid chromatograph/mass spectrometer (LC/MS) systems are commonly used in drug discovery research to purify large numbers of compounds made by parallel synthesis techniques. The systems in our lab are comprised of individual instruments that communicate continuously with control software in order to collect specific compounds based on mass triggering. Over time, communication errors may cause improper system operation, and excessive pressure during injection may cause system damage or a leak. The risks of sample loss and safety hazards precluded unattended overnight operation of the purification systems. A stand-alone monitoring system was developed to ensure proper purification system operation. Custom sensors and software are used to identify failures and remotely control power to the purification system. In response to a failure, the monitoring system will either shut down the purification system or, if possible, selectively reboot an instrument to allow continued operation. With the creation of the monitoring system, the purification system can be run unattended with

Automatic scanning system for the determination of local loss distributions in magnetic cores

The paper describes an automatic scanning system for the determination of local loss distributions in magnetic cores based on the rise-of-temperature method. The drawback of long measurement times is accepted opposite to the performance of unsupervised overnight operation. The reported measurements on model transformer cores indicate a good accuracy close to 5%.

Determination of (22R,S)budesonide in human plasma by automated liquid chromatography/thermospray mass spectrometry.

(22R,S)Budesonide was isolated from human plasma by solid-phase extraction. Switching from reversed-phase conditions during sample application and washing to normal-phase conditions during elution afforded a very clean extract. Budesonide was derivatized with acetic anhydride to form the 21-acetyl derivative before analysis by reversed-phase liquid chromatography combined with thermospray mass spectrometry. Deuterium-labelled budesonide was used as internal standard. Standard samples prepared in human albumin solution were used for the calibration curve. An automated liquid chromatography/mass spectrometry system, allowing unattended overnight operation, was used for routine analysis. The recovery of budesonide from plasma was 88.9 +/- 5.9% (mean +/- SD) and the method was linear over the range 0.30-30 pmol (amount analysed), corresponding to plasma concentrations of 0.10-10 nmol l-1. Budesonide could be measured down to 0.10 nmol l-1 with a within-day variation of 10-18% (CV). The error was less than +/- 15% at 0.10 nmol l-1 and less than +/- 7% at concentrations of 0.20 nmol l-1 or higher. The total imprecision between days was 9% (CV) at a concentration of 0.30 nmol l-1.

Operating Experience with the Hydrogen Isotope Separation System at Mound

The Hydrogen Isotope Separation System (HISS) is a general-purpose tritium recovery and enrichment processor that uses low-temperature distillation as the separation process. HISS processes feed mixtures containing all three isotopes of hydrogen (H,D,T) and yields an enriched tritium product up to 99.95% tritium, while producing a discardable raffinate. The three-column system operates continuously with unattended overnight operation and limited operation during weekends. Production runs with a full still inventory were started in October 1987, with individual runs lasting up to seven weeks. 6 refs., 2 figs., 1 tab.