Speckle Patterns With Atomic And Molecular De Broglie Waves

We have developed a nozzle source that delivers a continuous beam of atomic helium or molecular hydrogen having a high degree of transverse coherence and with adequate optical brightness to enable new kinds of experiments. Using this source we have measured single slit diffraction patterns and the first ever speckle-diffraction patterns using atomic and molecular de Broglie waves. Our results suggest fruitful application of coherent matter beams in dynamic scattering and diffractive imaging at short wavelength and with extreme surface sensitivity

A Comparison of Long-Lived, Proliferation Resistant Fast Reactors

Various methods have been proposed to transmute and thus consume the current inventory of trans-uranic waste that exists in spent light-water-reactor fuel. These methods include both critical and sub-critical systems. The neutronics of metallic and nitride fuels loaded with 20-30wt% light-water-reactor plutonium plus minor actinides for use in a lead-bismuth and sodium cooled fast reactor are discussed, with an emphasis on the fuel cycle life and isotopic content. Calculations show that core life can extend beyond 20 years, and the average actinide burn rate is similar for both the sodium and lead-bismuth cooled cases ranging from 0.5 to 0.9 g/MWd

Performance Comparison of Metallic, Actinide Burning Fuel in Lead-Bismuth and Sodium Cooled Fast Reactors

Various methods have been proposed to “incinerate” or “transmutate” the current inventory of trans-uranic waste (TRU) that exits in spent light-water-reactor (LWR) fuel, and weapons plutonium. These methods include both critical (e.g., fast reactors) and non-critical (e.g., accelerator transmutation) systems. The work discussed here is part of a larger effort at the Idaho National Engineering and Environmental Laboratory (INEEL) and at the Massachusetts Institute of Technology (MIT) to investigate the suitability of lead and lead-alloy cooled fast reactors for producing low-cost electricity as well as for actinide burning. The neutronics of non-fertile fuel loaded with 20 or 30-wt% light water reactor (LWR) plutonium plus minor actinides for use in a lead-bismuth cooled fast reactor are discussed in this paper, with an emphasis on the fuel cycle life and isotopic content. Calculations show that the average actinide burn rate is similar for both the sodium and lead-bismuth cooled cases ranging from -1.02 to -1.16 g/MWd, compared to a typical LWR actinide generation rate of 0.303 g/MWd. However, when using the same parameters, the sodium-cooled case went subcritical after 0.2 to 0.8 effective full power years, and the lead-bismuth cooled case ranged from 1.5 to 4.5 effective full power years

Exenatide extended release in patients with type 1 diabetes with and without residual insulin production

AimsTo test whether a long- acting GLP- 1 receptor agonist would improve glucose control in patients with type 1 diabetes (T1D) and to determine whether the presence of residual beta cell function would affect the response. In addition, we sought to determine whether the drug would affect beta cell function.MethodsWe performed a randomized placebo- controlled trial of exenatide extended release (ER) in participants with T1D with and without detectable levels of C- peptide. Seventy- nine participants were randomized to exenatide ER 2 mcg weekly, or placebo, stratified by the presence or absence of detectable C- peptide levels. The primary outcome was the difference in glycated haemoglobin (HbA1c) levels at 24- weeks. Participants were followed for another 6 months off study drug.ResultsAt week 24, the time of the primary outcome, the least squares (LS) mean HbA1c level was 7.76% (95% confidence interval [CI] 7.42, 8.10) in the exenatide ER group versus 8.0% (95% CI 7.64, 8.35) in the placebo group (P = 0.08). At week 12 the LS mean HbA1c levels were 7.71% (95% CI 7.37, 8.05) in the exenatide ER group versus 8.05% (95% CI 7.7, 8.4) in the placebo group (P = 0.01). The improvement at week 12 was driven mainly by those with detectable levels of C- peptide. Those treated with exenatide ER lost weight at 12 and 24- weeks compared to those treated with placebo (P- <0.001 and P = 0.007). The total insulin dose was lower, but not when corrected for body weight, and was not affected by residual insulin production. Adverse events were more frequent with exenatide ER, but hypoglycaemia was not increased.ConclusionTreatment with exenatide ER may have short- term benefits in some individuals with T1D who are overweight or who have detectable levels of C- peptide, but short- term improvements were not sustained.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163873/1/dom14121_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163873/2/dom14121.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163873/3/dom14121-sup-0001-Supinfo.pd

Direct Modulators of K-Ras-Membrane Interactions

Protein-membrane interactions (PMIs) are ubiquitous in cellular signaling. Initial steps of signal transduction cascades often rely on transient and dynamic interactions with the inner plasma membrane leaflet to populate and regulate signaling hotspots. Methods to target and modulate these interactions could yield attractive tool compounds and drug candidates. Here, we demonstrate that the conjugation of a medium-chain lipid tail to the covalent K-Ras(G12C) binder MRTX849 at a solvent-exposed site enables such direct modulation of PMIs. The conjugated lipid tail interacts with the tethered membrane and changes the relative membrane orientation and conformation of K-Ras(G12C), as shown by molecular dynamics (MD) simulation-supported NMR studies. In cells, this PMI modulation restricts the lateral mobility of K-Ras(G12C) and disrupts nanoclusters. The described strategy could be broadly applicable to selectively modulate transient PMIs

A prospective observational study of bacteraemia in adults admitted to an urban Mozambican hospital

Background. Bacteraemia is a common cause of fever among patients presenting to hospitals in sub-Saharan Africa. The worldwide rise of antibiotic resistance makes empirical therapy increasingly difficult, especially in resource-limited settings.Objectives. To describe the incidence of bacteraemia in febrile adults presenting to Maputo Central Hospital (MCH), an urban referral hospital in the capital of Mozambique, and characterise the causative organisms and antibiotic susceptibilities. We aimed to describe the antibiotic prescribing habits of local doctors, to identify areas for quality improvement. Methods. Inclusion criteria were: (i) ≥18 years of age; (ii) axillary temperature ≥38°C or ≤35°C; (iii) admission to MCH medical wards in the past 24 hours; and (iv) no receipt of antibiotics as an inpatient. Blood cultures were drawn from enrolled patients and incubated using the BacT/Alert automated system (bioMérieux, France). Antibiotic susceptibilities were tested using the Kirby-Bauer disc diffusion method. Results. Of the 841 patients enrolled, 63 (7.5%) had a bloodstream infection. The most common isolates were Staphylococcus aureus, Escherichia coli, and non-typhoidal Salmonella. Antibiotic resistance was common, with 20/59 (33.9%) of all bacterial isolates showing resistance to ceftriaxone, the broadest-spectrum antibiotic commonly available at MCH. Receipt of insufficiently broad empirical antibiotics was associated with poor in-hospital outcomes (odds ratio 8.05; 95% confidence interval 1.62 - 39.91; p=0.04). Conclusion. This study highlights several opportunities for quality improvement, including educating doctors to have a higher index of suspicion for bacteraemia, improving local antibiotic guidelines, improving communication between laboratory and doctors, and increasing the supply of some key antibiotics.

Fall in C-peptide during first 2 years from diagnosis: Evidence of at least two distinct phases from composite type 1 diabetes trialnet data.

Interpretation of clinical trials to alter the decline in β-cell function after diagnosis of type 1 diabetes depends on a robust understanding of the natural history of disease. Combining data from the Type 1 Diabetes TrialNet studies, we describe the natural history of β-cell function from shortly after diagnosis through 2 years post study randomization, assess the degree of variability between patients, and investigate factors that may be related to C-peptide preservation or loss. We found that 93% of individuals have detectable C-peptide 2 years from diagnosis. In 11% of subjects, there was no significant fall from baseline by 2 years. There was a biphasic decline in C-peptide; the C-peptide slope was −0.0245 pmol/mL/month (95% CI −0.0271 to −0.0215) through the first 12 months and −0.0079 (−0.0113 to −0.0050) from 12 to 24 months (P \u3c 0.001). This pattern of fall in C-peptide over time has implications for understanding trial results in which effects of therapy are most pronounced early and raises the possibility that there are time-dependent differences in pathophysiology. The robust data on the C-peptide obtained under clinical trial conditions should be used in planning and interpretation of clinical trials

Survival in Living Kidney Donors: An Australian and New Zealand Cohort Study Using Data Linkage

Background. Living kidney donors are a highly selected healthy population expected to have high survival postdonation, but mortality studies are limited. Our study aimed to compare mortality in living kidney donors with the general population in Australia and New Zealand, hypothesizing that donor survival would exceed average survival. Methods. All living kidney donors in Australia, 2004–2013, and New Zealand, 2004–2012, from the Australian and New Zealand Living Kidney Donor Registry were included. We ascertained primary cause of death from data linkage with national death registers. Standardized mortality ratios and relative survival were estimated, matching on age, sex, calendar year, and country. Results. Among 3253 living kidney donors, there were 32 deaths over 20331 person-years, with median follow-up 6.2 years [interquartile range: 3.9–8.4]. Only 25 donors had diabetes-fasting blood sugar level predonation, of which 3 had impaired glucose toler- ance. At discharge, the median creatinine was 108 μmol/L and estimated glomerular filtration rate was 58 mL/min/1.72 m2. Four deaths occurred in the first year: 2 from immediate complications of donation, and 2 from unrelated accidental causes. The leading cause of death was cancer (n = 16). The crude mortality rate was 157 (95% confidence interval [CI], 111- 222)/100000 person-y, and the standardized mortality ratio was 0.33 (95% CI, 0.24-0.47). The 5-year cumulative relative survival was 1.019 (95% CI, 1.014-1.021), confirming that the survival probability in living kidney donors was 2% higher rela- tive to the general population. Conclusions. As expected, mortality in living kidney donors was substantially lower than the general population and is reassuring for potential donor counseling. The Living Donor Registry only captured a third of the deaths, highlighting the benefit of data linkage to national death registries in the long-term follow-up of living kidney donors.This study received financial support from Kidney Health Australia (2015