Abstract Bone cement implantation syndrome (BCIS) is a potentially fatal complication of orthopedic surgeries that use cement. The symptoms of BCIS occur primarily during femoral fracture repairs, ...but this complication has been reported in a wide variety of cemented procedures. Clinical presentation of this syndrome begins as a cascade with hypoxia and hypotension; if it is not reversed, it ends with right‐sided heart failure and cardiac arrest. This syndrome usually occurs at cementation, prosthesis insertion, joint reduction, or tourniquet deflation, and should be treated with aggressive resuscitation and supportive care. This article provides a comprehensive explanation of bone cement, the identification and management of BCIS, and the roles of the perioperative team in the event of cardiopulmonary collapse. It includes a case study that can be used as an educational tool for simulation, mock drills, or staff meetings; it also may be used as a framework for creating policies.
Accurate estimates of mean nutrient composition of feeds, nutrient variance (i.e., standard deviation), and covariance (i.e., correlation) are needed to develop a more quantitative approach of ...formulating diets to reduce risk and optimize safety factors. Commercial feed-testing laboratories have large databases of composition values for many feeds, but because of potentially misidentified feeds or poorly defined feed names, these databases are possibly contaminated by incorrect results and could generate inaccurate statistics. The objectives of this research were to (1) design a procedure (also known as a mathematical filter) that generates accurate estimates of the first 2 moments i.e., the mean and (co)variance of the nutrient distributions for the largest subpopulation within a feed in the presence of outliers and multiple subpopulations, and (2) use the procedure to generate feed composition tables with accurate means, variances, and correlations. Feed composition data (>1,300,000 samples) were collected from 2 major US commercial laboratories. A combination of a univariate step and 2 multivariate steps (principal components analysis and cluster analysis) were used to filter the data. On average, 13.5% of the total samples of a particular feed population were removed, of which the multivariate steps removed the majority (66% of removed samples). For some feeds, inaccurate identification (e.g., corn gluten feed samples included in the corn gluten meal population) was a primary reason for outliers, whereas for other feeds, subpopulations of a broader population were identified (e.g., immature alfalfa silage within a broad population of alfalfa silage). Application of the procedure did not usually affect the mean concentration of nutrients but greatly reduced the standard deviation and often changed the correlation estimates among nutrients. More accurate estimates of the variation of feeds and how they tend to vary will improve the economic evaluation of feeds and risk assessment of diets, and provide the ability to implement stochastic programming.
Within-farm variation in forage composition can be substantial and potentially costly, and it presents challenges for sampling the forage accurately. We hypothesized that day-to-day variation in ...forage neutral detergent fiber (FNDF) concentrations and diet variation caused by sampling error would have negative effects on production measures in lactating dairy cows. Twenty-four Holstein cows (73d in milk) were used in 8 replicated 3×3 Latin squares with 21-d periods. Treatments were (1) control (CON), (2) variable (VAR), and (3) overreacting (ORR). On average, over the 21-d period, all 3 treatments were the same 24.7% FNDF and 48.2% forage dry matter (DM) composed of 67% alfalfa silage and 33% grass silage. The CON treatment was essentially consistent day-to-day in total forage and FNDF concentrations and proportion of alfalfa and grass silages. The VAR treatment changed daily (in a random pattern) in proportion of alfalfa and grass silages fed, which resulted in day-to-day changes in FNDF (range was 21.5 to 28%). The ORR treatment varied in a 5-d cyclic pattern in total forage and FNDF concentrations (26, 24, 28, and 21.5% FNDF). Over the 21d, ORR (25.1kg/d) had higher DM intake compared with CON (24.5kg/d) and VAR (24.3kg/d). Milk production (42.8kg/d), milk fat (3.5%), and milk protein (2.8%) were not affected by treatment; however, a treatment × day interaction was observed for milk production. Lower daily milk yields for VAR and ORR compared with CON were rare; they only followed sustained 4- and 5-d periods of feeding higher FNDF diets compared with CON. In contrast, increased daily milk yields for VAR and ORR versus CON were more frequent and followed sustained diet changes of only 2 or 3d. Lipolytic and lipogenic-related enzyme mRNA abundances in subcutaneous adipose tissue were not affected by treatment. Treatment × day interactions were observed for milk fatty acid markers of cellulolytic bacteria (iso-14:0, iso-15:0, iso-16:0) and lipolysis (18:0) and generally followed the expected response to changes in daily rations. Overall, extreme daily fluctuations in FNDF had no cumulative negative effect on production measures over a 21-d period, and daily responses to transient increases in FNDF were less than expected.
•A computer code for DRACS thermal performance evaluation for FHR is developed.•The code is validated using available experimental data from the literature.•The code is applied to a High-Temperature ...DRACS Test Facility (HTDF) at the OSU.
Direct Reactor Auxiliary Cooling System (DRACS) is a passive decay heat removal system proposed for the Fluoride-salt-cooled High-temperature Reactor (FHR) that combines coated particle fuel and a graphite moderator with a liquid fluoride salt as the coolant. The DRACS features three coupled natural circulation/convection loops, relying completely on buoyancy as the driving force. These loops are coupled through two heat exchangers, namely, the DRACS Heat Exchanger and the Natural Draft Heat Exchanger. In addition, a fluidic diode is employed to minimize the parasitic flow into the DRACS primary loop and correspondingly the heat loss to the DRACS during normal operation of the reactor, and to keep the DRACS ready for activation, if needed, during accidents.
To help with the design and thermal performance evaluation of the DRACS, a computer code using MATLAB has been developed. This code is based on a one-dimensional formulation and its principle is to solve the energy balance and integral momentum equations. By discretizing the DRACS system in the axial direction, a bulk mean temperature is assumed for each mesh cell. The temperatures of all the cells, as well as the mass flow rates in the DRACS loops, are predicted by solving the governing equations that are obtained by integrating the energy conservation equation over each cell and integrating the momentum conservation equation over each of the DRACS loops. In addition, an intermediate heat transfer loop equipped with a pump has also been modeled in the code. This enables the study of flow reversal phenomenon in the DRACS primary loop, associated with the pump trip process. Experimental data from a High-Temperature DRACS Test Facility (HTDF) are not available yet to benchmark the code. A preliminary code validation is performed by using natural circulation experimental data available in the literature, which are as closely relevant as possible. The code is subsequently applied to the HTDF that is under construction at the Ohio State University.
Background Higher numbers of registered nurses (RNs) per patient have been associated with improved patient outcomes in acute-care facilities. Variation in and associations of patient care staffing ...levels and hemodialysis facility characteristics have not been examined previously. Study Design Cross-sectional study using Poisson regression to examine associations between patient care staffing levels and hemodialysis facility characteristics. Setting & Participants 4,800 US hemodialysis facilities in the 2009 Centers for Medicare & Medicaid (CMS) End-Stage Renal Disease Annual Facility Survey (CMS-2744 form). Predictors Facility characteristics, including profit status, freestanding status, chain affiliation, and geographic region, adjusted for facility size, capacity, functional type, and urbanicity. Outcomes Patient care staffing levels, including ratios of RNs, licensed practical nurses (LPNs), patient care technicians (PCTs), composite staff (RN + LPN + PCT), social workers, and dietitians to in-center hemodialysis patients. Results After adjusting for background facility characteristics, ratios of RNs and LPNs to patients were 35% ( P < 0.001) and 42% ( P < 0.001) lower, respectively, but the PCT to patient ratio was 16% ( P < 0.001) higher in for-profit than nonprofit facilities (rate ratios of 0.65 95% CI, 0.63-0.68, 0.58 95% CI, 0.51-0.65, and 1.16 95% CI, 1.12-1.19, respectively). Regionally, compared to the Northeast, the adjusted RN to patient ratio was 14% ( P < 0.001) lower in the Midwest, 25% ( P < 0.001) lower in the South, and 18% ( P < 0.001) lower in the West. Even after additional adjustments, the large for-profit chains had significantly lower RN and LPN to patient ratios than the largest nonprofit chain, but a significantly higher PCT to patient ratio. Overall composite staffing levels also were lower in for-profit and chain-affiliated facilities. The patterns hold when hospital-based units were excluded. Limitations Nursing hours were not available. Two part-time staff were counted as one full-time equivalent, which may not always be accurate. Conclusions The significant variation in patient care staffing levels and its associations with facility characteristics warrants inclusion in future large-scale hemodialysis outcomes studies. End-stage renal disease networks and hemodialysis facilities should attend to quality assurance and performance improvement initiatives that maximize licensed nurse staffing levels in hemodialysis facilities.
This study evaluates the combined impact of replacing standard disinfectants with peroxyacetic acid/hydrogen peroxide sporicidal disinfectant, environmental hygiene (EH) best practices training and ...objective environmental hygiene monitoring on EH and infection control outcomes.
•A scaling analysis for the direct reactor auxiliary cooling system is performed.•Key dimensionless numbers are developed and similarity laws are proposed.•A scaling methodology that consists of core ...scaling and loop scaling is developed.•Scientific design of a scaled-down high-temperature DRACS facility is obtained.
The Direct Reactor Auxiliary Cooling System (DRACS) is a passive residual heat removal system proposed for the Fluoride-salt-cooled High-temperature Reactor (FHR) that combines the coated particle fuel and graphite moderator with a liquid fluoride salt as the coolant. The DRACS features three natural circulation/convection loops that rely on buoyancy as the driving force and are coupled via two heat exchangers, namely, the DRACS heat exchanger and the natural draft heat exchanger. A fluidic diode is employed to minimize the parasitic flow into the DRACS primary loop and correspondingly the heat loss to the DRACS during reactor normal operation, and to activate the DRACS in accidents when the reactor is shut down. While the DRACS concept has been proposed, there are no actual prototypic DRACS systems for FHRs built or tested in the literature. In this paper, a detailed scaling analysis for the DRACS is performed, which will provide guidance for the design of scaled-down DRACS test facilities. Based on the Boussinesq assumption and one-dimensional flow formulation, the governing equations are non-dimensionalized by introducing appropriate dimensionless parameters. The key dimensionless numbers that characterize the DRACS system are obtained from the non-dimensional governing equations. Based on the dimensionless numbers and non-dimensional governing equations, similarity laws are proposed. In addition, a scaling methodology has been developed, which consists of a core scaling and a loop scaling. The consistency between the core and loop scaling is examined via the reference volume ratio, which can be obtained from both the core and loop scaling processes. The scaling methodology and similarity laws have been applied to obtain a scientific design of a scaled-down high-temperature DRACS test facility.
The Direct Reactor Auxiliary Cooling System (DRACS) is a passive decay heat removal system proposed for the Fluoride salt-cooled High-temperature Reactor (FHR) that combines coated particle fuel and ...a graphite moderator with a liquid fluoride salt as the coolant. The DRACS features three coupled natural circulation/convection loops, relying completely on buoyancy as the driving force. These loops are coupled through two heat exchangers, namely, the DRACS heat exchanger (DHX) and the natural draft heat exchanger (NDHX). To experimentally investigate the thermal performance of the DRACS, a scaled-down low-temperature DRACS test facility (LTDF) has been constructed. The design of the LTDF is obtained through a detailed scaling analysis based on a 200-kW prototypic DRACS design developed at The Ohio State University. The LTDF has a nominal power capacity of 6 kW. It employs water pressurized at 1.0 MPa as the primary coolant, water near the atmospheric pressure as the secondary coolant, and ambient air as the ultimate heat sink. Three accident scenarios simulated in the LTDF are discussed in this paper. In the first scenario, startup of the DRACS system from a cold state is simulated with no initial primary coolant flow. In the second scenario, a reactor coolant pump trip process is studied, during which a flow reversal phenomenon in the DRACS primary loop occurs. In the third scenario, the pump trip process is studied with a simulated intermediate heat exchanger in operation during the simulated core normal operation. In all scenarios, natural circulation flows are developed as the transients approach their quasi steady states, demonstrating the functionality of the DRACS. The accident scenarios in the prototypic FHR design corresponding to the simulated ones in the LTDF are also predicted by following a scaling-up process. The predictions show that at any time during the simulated transient, the salt temperatures will be higher than their melting temperatures and that therefore there will be no issue of salt freezing in the three projected accident scenarios. However, the scaled-up primary salt temperatures indicate that the prototypic DHX may have been undersized and may need to be redesigned.
Immune inhibitory receptor genes that encode a variable (V) region, a unique V-like C2 (V/C2) domain, a transmembrane region, and a cytoplasmic tail containing immunoreceptor tyrosine-based ...inhibition motifs (ITIMs) have been described previously in two lineages of bony fish. In the present study, eleven related genes encoding distinct structural forms have been identified in Ictalurus punctatus (channel catfish), a well characterized immunological model system that represents a third independent bony fish lineage. Each of the different genes encodes an N-terminal V region but differs in the number of extracellular Ig domains, number and location of joining (J) region-like motifs, presence of transmembrane regions, presence of charged residues in transmembrane regions, presence of cytoplasmic tails, and/or distribution of ITIM(s) within the cytoplasmic tails. Variation in the numbers of genomic copies of the different gene types, their patterns of expression, and relative levels of expression in mixed leukocyte cultures (MLC) is reported. V region-containing immune-type genes constitute a far more complex family than recognized originally and include individual members that might function in inhibitory or, potentially activatory manners.
An extensive study of GeV light-ion-induced multifragmentation and its possible interpretation in terms of a nuclear liquid–gas phase transition has been performed with the Indiana Silicon Sphere ...(ISiS)
4
π
detector array. Measurements were performed with 5–15
GeV/
c
p
,
p
¯
, and
π
-
beams incident on
197Au and 2–5
GeV
3He incident on
natAg and
197Au targets. Both the reaction dynamics and the subsequent decay of the heavy residues have been explored. The data provide evidence for a dramatic change in the reaction observables near an excitation energy of
E
*
/
A
=
4
–
5
MeV
/
residue
nucleon
. In this region, fragment multiplicities and energy spectra indicate emission from an expanded/dilute source on a very short time scale (20–50
fm/
c). These properties, along with caloric curve and scaling-law behavior, yield a pattern that is consistent with a nuclear liquid–gas phase transition.
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