Forces associated with launch into space do not impact bone fracture healing

Segmental bone defects (SBDs) secondary to trauma invariably result in a prolonged recovery with an extended period of limited weight bearing on the affected limb. Soldiers sustaining blast injuries and civilians sustaining high energy trauma typify such a clinical scenario. These patients frequently sustain composite injuries with SBDs in concert with extensive soft tissue damage. For soft tissue injury resolution and skeletal reconstruction a patient may experience limited weight bearing for upwards of 6 months. Many small animal investigations have evaluated interventions for SBDs. While providing foundational information regarding the treatment of bone defects, these models do not simulate limited weight bearing conditions after injury. For example, mice ambulate immediately following anesthetic recovery, and in most cases are normally ambulating within 1-3 days post-surgery. Thus, investigations that combine disuse with bone healing may better test novel bone healing strategies. To remove weight bearing, we have designed a SBD rodent healing study in microgravity (µG) on the International Space Station (ISS) for the Rodent Research-4 (RR-4) Mission, which launched February 19, 2017 on SpaceX CRS-10 (Commercial Resupply Services). In preparation for this mission, we conducted an end-to-end mission simulation consisting of surgical infliction of SBD followed by launch simulation and hindlimb unloading (HLU) studies. In brief, a 2 mm defect was created in the femur of 10 week-old C57BL6/J male mice (n = 9-10/group). Three days after surgery, 6 groups of mice were treated as follows: 1) Vivarium Control (maintained continuously in standard cages); 2) Launch Negative Control (placed in the same spaceflight-like hardware as the Launch Positive Control group but were not subjected to launch simulation conditions); 3) Launch Positive Control (placed in spaceflight-like hardware and also subjected to vibration followed by centrifugation); 4) Launch Positive Experimental (identical to Launch Positive Control group, but placed in qualified spaceflight hardware); 5) Hindlimb Unloaded (HLU, were subjected to HLU immediately after launch simulation tests to simulate unloading in spaceflight); and 6) HLU Control (single housed in identical HLU cages but not suspended). Mice were euthanized 28 days after launch simulation and bone healing was examined via micro-Computed Tomography (µCT). These studies demonstrated that the mice post-surgery can tolerate launch conditions. Additionally, forces and vibrations associated with launch did not impact bone healing (p = .3). However, HLU resulted in a 52.5% reduction in total callus volume compared to HLU Controls (p = .0003). Taken together, these findings suggest that mice having a femoral SBD surgery tolerated the vibration and hypergravity associated with launch, and that launch simulation itself did not impact bone healing, but that the prolonged lack of weight bearing associated with HLU did impair bone healing. Based on these findings, we proceeded with testing the efficacy of FDA approved and novel SBD therapies using the unique spaceflight environment as a novel unloading model on SpaceX CRS-10

Reduction of pertechnetate by acetohydroxamic acid: Formation of [TcNO(AHA)2(H2O)]+ and implications for the UREX process.

Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the x-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry with the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a the d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but may be augmented by products of reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex (1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent; titration studies indicate a single species from pH 4.5 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The formation of 1 may strongly impact the fate of technetium in the nuclear fuel cycle

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Iron (II) and Silicate Effects on Mineralization and Immobilzation of Actinides

Abstract - The unique composition of the Yucca Mountain repository site, which contains large concentrations of silicate in an oxidative environment, has required extensive research into compound formation involving uranium and iron(II) under such conditions. The possibility of uranium leakage from within the containment vessels into the near-field ground water, as well as iron leaching from the vessel itself, necessitates study of the individual contributions of these elements for compound formation. By mimicking the known silicate concentration found in surrounding ground water and varying concentrations of both uranyl and iron(II), subsequent precipitation of uranyl silicate phases has shown evidence of iron(II) sorption to the available sites on the mineral surface. The mineralization seems to be driven by the formation of uranyl silicate, in contrast to iron(III)-control of precipitation in the oxidated system. Characterization of this system presented includes ICP-AES analysis as well as preliminary EDAX, XRD, and FT-I

Iron (III) Matrix Effects on Mineralization and Immobilization of Actinides

Abstract - A number of models for the Yucca Mountain Project nuclear waste repository use studies of actinide sorption onto well-defined iron hydroxide materials. In the case of a waste containment leak, however, a complex interaction between dissolved waste forms and failed containment vessel components can lead to immediate precipitation of migratory iron and uranyl in the silicate rich near-field environment. Use of the Fe(III) and UO22+ complexing agent acetohydroxamic acid (AHA) as a colorimetric agent for visible spectrophotometry is well-known. Using the second derivative of these spectra a distinct shift in iron complexation in the presence of silicate is seen that is not seen with uranyl or alone. Silica also decreases the ability of uranyl and ferric solutions to absorb hydroxide, hastening precipitation. These ferric silicate precipitates are highly amorphous and soluble. Precipitates formed in the presence of uranyl below ~1 mol% exhibit lower solubility than precipitates from up to 50 mol % and of uranyl silicates alone

Iron (II) sorption to mineral surfaces in uranyl and silicate rich media

Abstract - The unique composition of the Yucca Mountain repository site, which contains large concentrations of silicate in an oxidative environment, has required extensive research into compound formation involving uranium and iron(II) under such conditions. The possibility of uranium leakage from within the containment vessels into the near-field ground water, as well as iron leaching from the vessel itself, necessitates study of the individual contributions of these elements for compound formation. By mimicking the known silicate concentration found in surrounding ground water and varying concentrations of both uranyl and iron(II), subsequent precipitation of uranyl silicate phases has shown evidence of iron(II) sorption to the available sites on the mineral surface. The mineralization seems to be driven by the formation of uranyl silicate, in contrast to iron(III)-control of precipitation in the oxidated system. We present characterization of this system using ICP-AES/MS, EDAX, XRD, and single-crystal X-ray diffraction