Comparing complications of small-bore chest tubes to large-bore chest tubes in the setting of delayed hemothorax: a retrospective multicenter cohort study.

BACKGROUND: Previous studies have provided initial data suggesting that small-bore (SB, ≤ 14Fr) chest tubes have the same efficacy as large-bore (LB, > 14 Fr) chest tubes for acute hemothorax (HTX), but data continue to be lacking in the setting of delayed HTX. This study compared complications of SB chest tubes to LB tubes in patients with delayed HTX. METHODS: This was a retrospective observational study across 7.5 yrs. at 6 Level 1 trauma centers. Patients were included if 1) diagnosed with a HTX or > 1 rib fracture with bloody effusion from chest tube; 2) initial chest tube placed ≥36 h of hospital admission. Patients were excluded for hemopneumothoraces. The primary endpoint was having at least one of the following chest tube complications: tube replacement, VATS, tube falling out, tube clogging, pneumonia, retained HTX, pleural empyema. Secondary outcomes included chest tube output volume and drainage rate. Dependent/independent and parametric/non-parametric analyses were used to assess primary and secondary outcomes. RESULTS: There were 160 SB patients (191 tubes) and 60 LB patients (72 tubes). Both comparison groups were similar in multiple demographic, injury, clinical features. The median (IQR) tube size for each group was as follows: SB [12 Fr (12-14)] and LB [32 Fr (28-32)]. The risk of having at least one chest tube complication was similar for LB and SB chest tubes (14% vs. 18%, p = 0.42). LB tubes had significantly larger risk of VATS, while SB tubes had significantly higher risk of pneumonia. SB tubes had significantly slower least squares (LS) mean initial output drainage rate compared to LB tubes (52.2 vs. 213.4 mL/hour, p < 0.001), but a non-parametric analysis suggested no significant difference in median drainage rates between groups 39.7 [23.5-242.0] mL/hr. vs. 38.6 [27.5-53.8], p = 0.81. LB and SB groups had similar initial output volume (738.0 mL vs. 810.9, p = 0.59). CONCLUSIONS: There was no clearly superior chest tube diameter size; both chest tube sizes demonstrated risks and benefits. Clinicians must be aware of these potential tradeoffs when deciding on the diameter of chest tube for the treatment of delayed HTXs.

The effect of orthopaedic surgeons' and interventional radiologists' availability on the priority treatment sequence for hemodynamically unstable pelvic fractures: a survey of US Level I trauma centers.

BACKGROUND: Most guidelines recommend both pelvic packing (PP) and angioembolization for hemodynamically unstable pelvic fractures, however their sequence varies. Some argue to use PP first because orthopaedic surgeons are more available than interventional radiologists; however, there is no data confirming this. METHODS: This cross-sectional survey of 158 trauma medical directors at US Level I trauma centers collected the availability of orthopaedic surgeons and interventional radiologists, the number of orthopaedic trauma surgeons trained to manage pelvic fractures, and priority treatment sequence for hemodynamically unstable pelvic fractures. The study objective was to compare the availability of orthopaedic surgeons to interventional radiologists and describe how the availability of orthopaedic surgeons and interventional radiologists affects the treatment sequence for hemodynamically unstable pelvic fractures. Fisher's exact, chi-squared, and Kruskal-Wallis tests were used, alpha = 0.05. RESULTS: The response rate was 25% (40/158). Orthopaedic surgeons (86%) were on-site more often than interventional radiologists (54%), p = 0.003. Orthopaedic surgeons were faster to arrive 39% of the time, and interventional radiologists were faster to arrive 6% of the time. There was a higher proportion of participants who prioritized PP before angioembolization at centers with above the average number (> 3) of orthopaedic trauma surgeons trained to manage pelvic fractures, as among centers with equal to or below average, p = 0.02. Arrival times for orthopaedic surgeons did not significantly predict prioritization of angioembolization or PP. CONCLUSIONS: Our results provide evidence that orthopaedic surgeons typically are more available than interventional radiologists but contrary to anecdotal evidence most participants used angioembolization first. Familiarity with the availability of orthopaedic surgeons and interventional radiologists may contribute to individual trauma center's treatment sequence.

Leveraging genetically simple traits to identify small-effect variants for complex phenotypes.

BACKGROUND: Polymorphisms underlying complex traits often explain a small part (less than 1 %) of the phenotypic variance (σ2P). This makes identification of mutations underling complex traits difficult and usually only a subset of large-effect loci are identified. One approach to identify more loci is to increase sample size of experiments but here we propose an alternative. The aim of this paper is to use secondary phenotypes for genetically simple traits during the QTL discovery phase for complex traits. We demonstrate this approach in a dairy cattle data set where the complex traits were milk production phenotypes (fat, milk and protein yield; fat and protein percentage in milk) measured on thousands of individuals while secondary (potentially genetically simpler) traits are detailed milk composition traits (measurements of individual protein abundance, mineral and sugar concentrations; and gene expression). RESULTS: Quantitative trait loci (QTL) were identified using 11,527 Holstein cattle with milk production records and up to 444 cows with milk composition traits. There were eight regions that contained QTL for both milk production and a composition trait, including four novel regions. One region on BTAU1 affected both milk yield and phosphorous concentration in milk. The QTL interval included the gene SLC37A1, a phosphorous antiporter. The most significant imputed sequence variants in this region explained 0.001 σ2P for milk yield, and 0.11 σ2P for phosphorus concentration. Since the polymorphisms were non-coding, association mapping for SLC37A1 gene expression was performed using high depth mammary RNAseq data from a separate group of 371 lactating cows. This confirmed a strong eQTL for SLC37A1, with peak association at the same imputed sequence variants that were most significant for phosphorus concentration. Fitting any of these variants as covariables in the association analysis removed the QTL signal for milk production traits. Plausible causative mutations in the casein complex region were also identified using a similar strategy. CONCLUSIONS: Milk production traits in dairy cows are typical complex traits where polymorphisms explain only a small portion of the phenotypic variance. However, here we show that these mutations can have larger effects on secondary traits, such as concentrations of minerals, proteins and sugars in the milk, and expression levels of genes in mammary tissue. These larger effects were used to successfully map variants for milk production traits. Genetically simple traits also provide a direct biological link between possible causal mutations and the effect of these mutations on milk production.

Optical waveguide lightmode spectroscopy (OWLS) as a sensor for thin film and quantum dot corrosion.

Optical waveguide lightmode spectroscopy (OWLS) is usually applied as a biosensor system to the sorption-desorption of proteins to waveguide surfaces. Here, we show that OWLS can be used to monitor the quality of oxide thin film materials and of coatings of pulsed laser deposition synthesized CdSe quantum dots (QDs) intended for solar energy applications. In addition to changes in data treatment and experimental procedure, oxide- or QD-coated waveguide sensors must be synthesized. We synthesized zinc stannate (Zn(2)SnO(4)) coated (Si,Ti)O(2) waveguide sensors, and used OWLS to monitor the relative mass of the film over time. Films lost mass over time, though at different rates due to variation in fluid flow and its physical effect on removal of film material. The Pulsed Laser Deposition (PLD) technique was used to deposit CdSe QD coatings on waveguides. Sensors exposed to pH 2 solution lost mass over time in an expected, roughly exponential manner. Sensors at pH 10, in contrast, were stable over time. Results were confirmed with atomic force microscopy imaging. Limiting factors in the use of OWLS in this manner include limitations on the annealing temperature that maybe used to synthesize the oxide film, and limitations on the thickness of the film to be studied. Nevertheless, the technique overcomes a number of difficulties in monitoring the quality of thin films in-situ in liquid environments.

Photooxidation of chloride by oxide minerals: implications for perchlorate on Mars.

We show that highly oxidizing valence band holes, produced by ultraviolet (UV) illumination of naturally occurring semiconducting minerals, are capable of oxidizing chloride ion to perchlorate in aqueous solutions at higher rates than other known natural perchlorate production processes. Our results support an alternative to atmospheric reactions leading to the formation of high concentrations of perchlorate on Mars.

The use of flow-injection analysis with chemiluminescence detection of aqueous ferrous iron in waters containing high concentrations of organic compounds.

An evaluation of flow-injection analysis with chemiluminescence detection (FIA-CL) to quantify Fe(2+) ((aq)) in freshwaters was performed. Iron-coordinating and/or iron-reducing compounds, dissolved organic matter (DOM), and samples from two natural water systems were used to amend standard solutions of Fe(2+) ((aq)). Slopes of the response curves from ferrous iron standards (1 - 100 nM) were compared to the response curves of iron standards containing the amendments. Results suggest that FIA-CL is not suitable for systems containing ascorbate, hydroxylamine, cysteine or DOM. Little or no change in sensitivity occurred in solutions of oxalate and glycine or in natural waters with little organic matter.

Genotype by environment interaction for fertility, survival, and milk production traits in Australian dairy cattle.

The existence of a genotype x environment interaction (G x E) for fertility traits, survival, and milk yield traits was examined by considering performance recorded in different calving systems (seasonal, split, and year round) or regions as different traits. For fertility traits and survival, G x E were also investigated by applying a random regression model using continuous environmental variables, such as level of herd milk production, temperature-humidity index, and herd size as environmental descriptors. The traits considered were calving interval, calving to first service interval (CFS), 25-d nonreturn rate at first service, pregnancy rate, survival, milk yield, fat yield, and protein yield and percentage. Data on Holstein-Friesian cows that calved between 1997 and 2005 were analyzed. The number of cows included in the analyses ranged from approximately 21,000 for pregnancy rate to approximately one-half million for survival. For all traits, heterogeneity in additive and phenotypic variances was observed. For example, for CFS the additive genetic and phenotypic variance in seasonal calving herds was only 9 and 15% of that in year-round calving herds, respectively. Genetic correlations among calving systems for milk yield traits were greater than 0.96. For calving interval, the lowest genetic correlation, of 0.83, was between split and year-round calving herds, but for CFS and pregnancy rate, genetic correlations as low as 0.37 were observed, although these estimates were associated with large standard errors. Genetic correlations between traits recorded in different Australian regions were greater than 0.89. Heritability and phenotypic variance for milk yield traits were the greatest in region 1, which consisted of Queensland, West Australia, South Australia, and New South Wales, and were least in region 3, which included Gippsland and Tasmania, in accordance with mean milk yield levels. Genetic correlations as low as 0.5 for some fertility traits between the 5th and 95th percentile of the distribution of the environmental descriptors, such as herd size and average herd milk production, were also observed. However, these estimates had large standard errors. Regardless of the environmental descriptor used, there was no evidence for the presence of a large G x E that resulted in economically significant reranking of bulls.

Structural and redox properties of mitochondrial cytochrome c co-sorbed with phosphate on hematite (alpha-Fe2O3) surfaces.

The interaction of metalloproteins with oxides has implications not only for bioanalytical systems and biosensors but also in the areas of biomimetic photovoltaic devices, bioremediation, and bacterial metal reduction. Here, we investigate mitochondrial ferricytochrome c (Cyt c) co-sorption with 0.01 and 0.1 M phosphate on hematite (alpha-Fe2O3) surfaces as a function of pH (2-11). Although Cyt c sorption to hematite in the presence of phosphate is consistent with electrostatic attraction, other forces act upon Cyt c as well. The occurrence of multilayer adsorption, and our AFM observations, suggest that Cyt c aggregates as the pH approaches the Cyt c isoelectric point. In solution, methionine coordination of heme Fe occurs only between pH 3 and 7, but in the presence of phosphate this coordination is retained up to pH 10. Electrochemical evidence for the presence of native Cyt c occurs down to pH 3 and up to pH 10 in the absence of phosphate, and this range is extended to pH 2 and 11 in the presence of phosphate. Cyt c that initially adsorbs to a hematite surface may undergo conformation change and coat the surface with unfolded protein such that subsequently adsorbing protein is more likely to retain the native conformational state. AFM provides evidence for rapid sorption kinetics for Cyt c co-sorbed with 0.01 or 0.1 M phosphate. Cyt c co-sorbed with 0.01 M phosphate appears to unfold on the surface of hematite while Cyt c co-sorbed with 0.1 M phosphate possibly retains native conformation due to aggregation.

Estimation of genetic parameters for milk fat depression in dairy cattle.

The objective of this study was to apply reaction norm models to milk recording data to investigate genetic variation in and environmental sensitivity of susceptibility to milk fat depression (MFD). Data comprised 556,276 test-day records of 80,493 heifers in 1043 herds. Breeding values and genetic variances for fat percentage and fat yield were estimated by applying random regression models to average herd-test-day fat percentage. Genetic and permanent environmental correlations between fat yield expressed in different environments ranged, respectively, from 0.83 to 1.00 and from 0.29 to 1.00. Genetic and permanent environmental correlations between fat percentage expressed in different environments ranged, respectively, from 0.87 to 1.00 and from -0.05 to 0.99. Two traits were defined for MFD. The first trait reflected variation of milk fat percentage of animals within lactation after correction for year-season, herd-test-day, age-at-calving, and stage-of-lactation. This trait had an estimated heritability of about 5% and a genetic correlation between the fifth and 95th percentile of the data of 0.50. The second trait reflected the deviation of an animal's fat percentage on a test-day from its expected fat percentage based on fat percentage on the first test-day. This trait had an estimated heritability of about 4% and a genetic correlation between the fifth and 95th percentile of the data of 0.43. The correlation between estimated breeding values of sires for the 2 MFD traits was -0.3. Our results suggest that genetic variation in susceptibility to MFD is present and that selection for reduced susceptibility to MFD is possible.

Reaction of hydroquinone with hematite; I. Study of adsorption by electrochemical-scanning tunneling microscopy and X-ray photoelectron spectroscopy.

The reaction of hematite with quinones and the quinone moieties of larger molecules may be an important factor in limiting the rate of reductive dissolution, especially by iron-reducing bacteria. Here, the electrochemical and physical properties of hydroquinone adsorbed on hematite surfaces at pH 2.5-3 were investigated with cyclic voltammetry (CV), electrochemical-scanning tunneling microscopy (EC-STM), and X-ray photoelectron spectroscopy (XPS). An oxidation peak for hydroquinone was observed in the CV experiments, as well as (photo)reduction of iron and decomposition of the solvent. The EC-STM results indicate that hydroquinone sometimes forms an ordered monolayer with approximately 1.1 QH(2)/nm(2), but can be fairly disordered (especially when viewed at larger scales). XPS results indicate that hydroquinone and benzoquinone are retained at the interface in increasing amounts as the reaction proceeds, but reduced iron is not observed. These results suggest that quinones do not adsorb by an inner-sphere complex where adsorbate-surface interactions determine the adsorbate surface structure, but rather in an outer-sphere complex where interactions among the adsorbate molecules dominate.

Reaction of hydroquinone with hematite; II. Calculated electron-transfer rates and comparison to the reductive dissolution rate.

The rate of reaction of hematite with quinones and the quinone moieties of larger molecules may be an important factor in limiting the rate of reductive dissolution of hematite, especially by iron-reducing bacteria. It is possible that the rate of reductive dissolution of hematite in the presence of excess hydroquinone at pH 2.5 may be limited by the electron-transfer rate. Here, a reductive dissolution rate was measured and compared to electron-transfer rates calculated using Marcus theory. An experimental rate constant was measured at 9.5 x 10 (-6) s(-1) and the reaction order with respect to the hematite concentration was found to be 1.1. Both the dissolution rate and the reaction order of hematite concentration compare well with previous measurements. Of the Marcus theory calculations, the inner-sphere part of the reorganization energy and the electronic coupling matrix element for hydroquinone self-exchange electron transfer are calculated using ab initio methods. The second order self-exchange rate constant was calculated to be 1.3 x 10 (7) M(-1)s(-1), which compares well with experimental measurements. Using previously published data calculated for hexaquairon(III)/(II), the calculated electron-transfer rate for the cross reaction with hydroquinone also compares well to experimental measurements. A hypothetical reductive dissolution rate is calculated using the first-order electron-transfer rate constant and the concentration of total adsorbed quinone. Three different models of the hematite surface are used as well as multiple estimates for the reduction potential, the surface charge, and the adsorption density of hydroquinone. No calculated dissolution rate is less than five orders of magnitude faster than the experimentally measured one.

Adatom Fe(III) on the hematite surface: Observation of a key reactive surface species.

The reactivity of a mineral surface is determined by the variety and population of different types of surface sites (e.g., step, kink, adatom, and defect sites). The concept of "adsorbed nutrient" has been built into crystal growth theories, and many other studies of mineral surface reactivity appeal to ill-defined "active sites." Despite their theoretical importance, there has been little direct experimental or analytical investigation of the structure and properties of such species. Here, we use ex-situ and in-situ scanning tunneling microcopy (STM) combined with calculated images based on a resonant tunneling model to show that observed nonperiodic protrusions and depressions on the hematite (001) surface can be explained as Fe in an adsorbed or adatom state occupying sites different from those that result from simple termination of the bulk mineral. The number of such sites varies with sample preparation history, consistent with their removal from the surface in low pH solutions.

Genotype x environment interaction for milk production of daughters of Australian dairy sires from test-day records.

In Australia, dairy farming is carried out in environments that vary in many ways, including level of feeding and climate variables such as temperature and humidity. The aim of this study was to assess the magnitude of genotype x environment interactions (GxE) on milk production traits (milk yield, protein yield, and fat yield) for a range of environmental descriptors. The environment on individual test days was described by herd size (HS), average herd protein yield (AHTDP), herd test-day coefficient of variation for protein yield (HTDCV), and temperature humidity index (THI). A sire random regression model was used to model the response of a sire's daughters to variation in the environment and to calculate the genetic correlation between the same traits measured in two widely different environments. Using test-day records, rather than average lactation yields, allowed exploitation of within-cow variation as well as between-cow variation at different levels of AHTDP, and led to more accurate estimates of sire breeding values for "response to environment." The greatest GxE observed was due to variation in AHTDP, with a genetic correlation of 0.78 between protein yield when AHTDP = 0.54 kg and protein yield when AHTDP = 1.1 kg (the 5th and 95th percentile of the distribution of AHTDP). The GxE was also observed for THI, with a genetic correlation of 0.90 between protein yield at the 5th and 95th percentile of THI. The use of response to environment estimated breeding values to improve the accuracy of international sire evaluations is discussed.

Genetic parameters for milk production of Australian beef cows and weaning weight of their calves.

Estimates of covariance components were obtained for milk production of beef cows, measured by the weigh-suckle-weigh method, and weaning weight and preweaning growth of their calves for a herd of Polled Herefords and a herd of a multibreed synthetics, so-called Wokalups. Analyses were carried out by restricted maximum likelihood fitting an animal model incorporating both direct and maternal genetic and permanent environmental effects and allowing for the direct-maternal covariances. Average 14-h milk yield was 3.6 kg for Herefords and 4.9 kg for Wokalups and heritabilities were .12 and .08, respectively. Treating preweaning gain of the calf as a trait of the cow, estimates of the additive genetic and permanent environmental correlations between preweaning gain and milk yield were higher for Herefords (.73 and 1.00, respectively) than for Wokalups (.53 and .77). Bivariate analyses of milk production (treated as a trait of the cow) and weaning weight (treated as a trait of the calf) showed virtually no direct additive genetic, direct permanent environmental, or phenotypic association between the two traits but identified strong correlations between direct effects for milk yield and maternal effects for weaning weight. The estimate of the direct-maternal genetic correlation between milk yield and weaning weight was .80 for both breeds, and the estimated correlation between direct, permanent environmental effects for milk yield and maternal, permanent environmental effects on weaning weight was unity for Herefords and .89 for Wokalups. Results indicate that milk production is the main determinant of maternal effects on the growth of beef calves with breed differences in the importance of maternal effects largely attributable to differences in milk production.

Genetic parameters for growth traits of Australian beef cattle from a multibreed selection experiment.

Estimates of covariance components and genetic parameters were obtained for birth, weaning, 200-d, and 400-d weight for a herd of Polled Herefords and a herd of a multibreed synthetics, the so-called Wokalups. Data originated from an experiment in Western Australia selecting for preweaning growth rate. Analyses were carried out by REML fitting an animal model including genetic and permanent environmental maternal effects. Wokalups showed consistently more phenotypic variation, partly due to a scale effect, and higher direct and lower maternal heritabilities than Herefords. Maternal environmental effects were more than twice as important in Herefords than in Wokalups. Estimates of both genetic and environmental correlations among weaning and subsequent weights were essentially unity, identifying maternal effects found for postweaning weights as a "carry over" of those on weaning weight.

Freeze-thawed skeletal muscle autografts used for brachial plexus repair in the non-human primate.

An experimental study undertaken in the marmoset is reported. A defect in the lateral cord of the brachial plexus was repaired with a longitudinally aligned freeze-thawed skeletal muscle autograft. Recovery was assessed after one year using sensory and motor electrophysiological and also histological examination of the nerve. The results show that this is a satisfactory method of peripheral nerve repair in the marmoset. It is suggested that the technique may be applicable to repair of the human brachial plexus.

Inherited progressive spinal myelinopathy in Murray Grey cattle.

In a breeding experiment conducted to determine the mode of inheritance of progressive spinal myelinopathy, semen from a Murray Grey bull which had previously sired affected calves was used to inseminate 120 cows. Female progeny were then inseminated with semen from the same bull. Of the 51 calves born, six (11.8%) had spinal cord lesions consistent with progressive spinal myelinopathy. From analysis of pedigrees and the results of the breeding experiment it was concluded that the condition was inherited as an autosomal recessive condition in Murray Grey cattle.