Multi-element isotopic analysis of hot particles from Chornobyl.

Microscopic fuel fragments, so-called "hot particles", were released during the 1986 accident at the Chornobyl nuclear powerplant and continue to contaminate the exclusion zone in northern Ukraine. Isotopic analysis can provide vital information about sample origin, history and contamination of the environment, though it has been underutilized due to the destructive nature of most mass spectrometric techniques, and inability to remove isobaric interference. Recent developments have diversified the range of elements that can be investigated through resonance ionization mass spectrometry (RIMS), notably in the fission products.

An overview of NRL's NAUTILUS: a combination SIMS-AMS for spatially resolved trace isotope analysis.

We present a description of the capabilities and performance of the NAval Ultra-Trace Isotope Laboratory's Universal Spectrometer (NAUTILUS) at the U.S. Naval Research Laboratory.

U-Pu Mixed Oxide Particle Analysis by NAUTILUS and Implications for Next-Generation Verification Challenges.

Precise and accurate measurement of U and Pu isotopes from micrometer-sized particles represents new verification challenges for the International Atomic Energy Agency. The U and Pu isotopes and U-Pu elemental ratio provide valuable information about the intended use, the production process, and the purification process of Pu and mixed oxide (MOX) fuels. We demonstrate the ability to directly measure U and Pu isotopes from MOX fuel particles using the U.

Direct, uncorrected, molecule-free analysis of U from uranium-bearing particles with NAUTILUS: a new kind of mass spectrometer.

We demonstrate use of the Naval Ultra-Trace Isotope Laboratory's Universal Spectrometer (NAUTILUS) at the U.S. Naval Research Laboratory (NRL) to measure 236U directly from uranium-bearing particles free from molecular isobaric interferences.

Discovery of fissionogenic Cs and Ba capture five years after Oklo reactor shutdown.

Understanding the release and sequestration of specific radioactive signatures into the environment is of extreme importance for long-term nuclear waste storage and reactor accident mitigation. Recent accidents at the Fukushima and Chernobyl nuclear reactors released radioactive Cs and Cs into the environment, the former of which is still live today. We have studied the migration of fission products in the Oklo natural nuclear reactor using an isotope imaging capability, the NAval Ultra-Trace Isotope Laboratory's Universal Spectrometer (NAUTILUS) at the US Naval Research Laboratory.

Fully convolutional neural network for removing background in noisy images of uranium bearing particles.

A fully convolutional neural network (FCN) was developed to supersede automatic or manual thresholding algorithms used for tabulating SIMS particle search data. The FCN was designed to perform a binary classification of pixels in each image belonging to a particle or not, thereby effectively removing background signal without manually or automatically determining an intensity threshold. Using 8000 images from 28 different particle screening analyses, the FCN was trained to accurately predict pixels belonging to a particle with near 99% accuracy.

Avoiding stay in the intensive care unit after liver transplantation: a score to assign location of care.

Select liver transplantation (LT) recipients in our program are transferred from operating room to postanesthesia care unit for recovery and extubation with transfer to the ward, completely eliminating an intensive care unit (ICU) stay. Developing a reliable method to determine patients suitable for fast-tracking would be of practical benefit to centers considering this practice. The aim of this study was to create a fast-tracking probability score that could be used to predict successful assignment of care location after LT.

Surgical site infections after liver retransplantation: incidence and risk factors.

Surgical site infections (SSIs) after liver transplantation (LT) are associated with an increased risk of graft loss and death. The incidence of SSIs after LT and their risk factors have been determined for first LT but not for second LT. The importance of reporting the incidence of SSIs risk-stratified by first LT versus second LT is not known.

Outcomes following liver transplantation in intensive care unit patients.

Aim: To determine feasibility of liver transplantation in patients from the intensive care unit (ICU) by estimating graft and patient survival.

Methods: This single center retrospective study included 39 patients who had their first liver transplant directly from the intensive care unit and 927 non-ICU patients who were transplanted from hospital ward or home between January 2005 and December 2010.

Results: In comparison to non-ICU patients, ICU patients had a higher model for end-stage liver disease (MELD) at transplant (median: 37 vs 20, P < 0.

Improving Students' Learning With Effective Learning Techniques: Promising Directions From Cognitive and Educational Psychology.

Many students are being left behind by an educational system that some people believe is in crisis. Improving educational outcomes will require efforts on many fronts, but a central premise of this monograph is that one part of a solution involves helping students to better regulate their learning through the use of effective learning techniques. Fortunately, cognitive and educational psychologists have been developing and evaluating easy-to-use learning techniques that could help students achieve their learning goals.

Liver transplantation in the critically ill: donation after cardiac death compared to donation after brain death grafts.

 Patients with end stage liver disease may become critically ill prior to LT requiring admission to the intensive care unit (ICU). The high acuity patients may be thought too ill to transplant; however, often LT is the only therapeutic option. Choosing the correct liver allograft for these patients is often difficult and it is imperative that the allograft work immediately.

Asystole to cross-clamp period predicts development of biliary complications in liver transplantation using donation after cardiac death donors.

This study sought to determine the procurement factors that lead to development of intrahepatic bile duct strictures (ITBS) and overall biliary complications in recipients of donation after cardiac death (DCD) liver grafts. Detailed information for different time points during procurement (withdrawal of support; SBP < 50 mmHg; oxygen saturation <30%; mandatory wait period; asystole; incision; aortic cross clamp) and their association with the development of ITBS and overall biliary complications were examined using logistic regression. Two hundred and fifteen liver transplants using DCD donors were performed between 1998 and 2010 at Mayo Clinic Florida.

Is a mandatory intensive care unit stay needed after liver transplantation? Feasibility of fast-tracking to the surgical ward after liver transplantation.

The continuation of hemodynamic, respiratory, and metabolic support for a variable period after liver transplantation (LT) in the intensive care unit (ICU) is considered routine by many transplant programs. However, some LT recipients may be liberated from mechanical ventilation shortly after the discontinuation of anesthesia. These patients might be appropriately discharged from the postanesthesia care unit (PACU) to the surgical ward and bypass the ICU entirely.

Recurrent liver failure caused by IgG4 associated cholangitis.

Immunoglobulin G4 associated cholangitis (IAC) is an autoimmune disease associated with autoimmune pancreatitis (AIP). It presents with clinical and radiographic findings similar to primary sclerosing cholangitis (PSC). IAC commonly has a faster, more progressive onset of symptoms and it is more common to see obstructive jaundice in IAC patients compared to those with PSC.

Should donation after cardiac death liver grafts be used for retransplantation?

Introduction: Donation after cardiac death (DCD) donors provide an important source of livers that has been used to expand the donor pool. As a consequence of increased numbers of OLT, allograft failure due to early and late complications and disease recurrence are more commonly encountered. The only life saving treatment for patients with liver allograft failure is liver re-transplantation (LR).

Events in procurement as risk factors for ischemic cholangiopathy in liver transplantation using donation after cardiac death donors.

The use of donation after cardiac death (DCD) liver grafts is controversial because of the overall increased rates of graft loss and morbidity, which are mostly related to the consequences of ischemic cholangiopathy (IC). In this study, we sought to determine the factors leading to graft loss and the development of IC and to compare patient and graft survival rates for recipients of DCD liver grafts and recipients of donation after brain death (DBD) liver grafts in a large series at a single transplant center. Two hundred liver transplants with DCD donors were performed between 1998 and 2010 at Mayo Clinic Florida.

Association of surgeon with surgical site infection after liver transplantation.

Surgical site infection (SSI) after liver transplantation has been associated with increased risk of allograft loss and death. Identification of modifiable risk factors for these infections is imperative. To our knowledge, intraoperative practices associated with transplant surgeons have not been assessed as a risk factor.

A single-center experience with biliary reconstruction in retransplantation: duct-to-duct or Roux-en-Y choledochojejunostomy.

Retransplantation is the only therapy for patients who have a failing liver graft, and it can be technically challenging. Although duct-to-duct (DD) biliary reconstruction is considered standard in deceased donor orthotopic whole organ liver transplantation, Roux-en-Y (RY) choledochojejunostomy is preferred by most for biliary reconstruction in retransplantation. We performed a retrospective review of 128 patients who underwent retransplantation after a first transplant with DD biliary construction.

Use of liver grafts from donation after cardiac death donors for recipients with hepatitis C virus.

Hepatitis C virus (HCV) infection is the most common indication for orthotopic liver transplantation in the United States. Although studies have addressed the use of expanded criteria donor organs in HCV(+) patients, to date the use of liver grafts from donation after cardiac death (DCD) donors in HCV(+) patients has been addressed by only a limited number of studies. This retrospective analysis was undertaken to study the outcomes of DCD liver grafts used in HCV(+) recipients.

Long-term outcomes after third liver transplant.

Objectives: Orthotopic liver transplant is the treatment of choice for patients with end-stage liver disease. Patients with first graft failure requiring liver retransplant are commonly seen at most liver transplant centers. However, patients with a second graft failure requiring a third graft are uncommon.