Development of spinning-disk solid sample delivery system for high-repetition rate x-ray free electron laser experiments.

X-ray free-electron lasers (XFELs) deliver intense x-ray pulses that destroy the sample in a single shot by a Coulomb explosion. Experiments using XFEL pulse trains or the new generation of high-repetition rate XFELs require rapid sample replacement beyond those provided by the systems now used at low repletion-rate XFELs. We describe the development and characterization of a system based on a spinning disk to continuously deliver a solid sample into an XFEL interaction point at very high speeds. We tested our system at the Linac Coherent Light Source and European XFEL hard x-ray nano-focus instruments, employing it to deliver a 25 µm copper foil sample, which can be used as a gain medium for stimulated x-ray emission for the proposed x-ray laser oscillator.

Improving the Quality of Magnetic Resonance Cholangiopancreatography Images.

The purpose of this study was to address the variability in quality of magnetic resonance cholangiopancreatography (MRCP) images by examining differences in quality grades before and after modifying the MRCP protocol to include placement of physical bellows while scanning. This single institution quality improvement initiative included 727 MRCP examinations performed from July 2019 to December 2020 in patients 18 years and older. The Define, Measure, Analyze, Improve, and Control (DMAIC) strategy was utilized to explore factors related to MRCP image quality and identify solutions that could create effective change. Based on the results of this analysis, MRCP protocols were changed in December 2019 to include physical bellows. Examinations were grouped as occurring either pre- or postintervention as well as whether they occurred in an inpatient or outpatient setting. MRCP examinations were evaluated for quality and labeled either nondiagnostic or diagnostic. A logistic regression model was fit to compare the odds of a diagnostic QA grade between preintervention and postintervention groups and inpatient and outpatient settings. The preintervention group had 41.12% of MRCP studies of diagnostic quality, and the postintervention group had 60.57% of studies of diagnostic quality. The estimated odds of an image being of diagnostic quality in the postintervention group were 2.46 times the odds for the preintervention group across all departments and patient classes (P < 0.001). The estimated odds of an image being of diagnostic quality in the outpatient group were 2.01 times the odds for those in the inpatient group (P < 0.001). Utilizing a standardized quality improvement method can lead to sustained improvements in the diagnostic quality of MRCP studies.

Effects of Benazepril on Survival of Dogs with Chronic Kidney Disease: A Multicenter, Randomized, Blinded, Placebo-Controlled Clinical Trial.

BACKGROUND: Chronic kidney disease (CKD) is an important cause of morbidity and mortality in dogs. OBJECTIVE: To evaluate the efficacy in prolonging survival and safety of benazepril administration to dogs with CKD. ANIMALS: Forty-nine client-owned dogs with CKD. METHODS: Dogs were randomized to benazepril (0.25 to <0.5 mg/kg) or placebo once daily for up to 2 years in a prospective, multicenter, blinded clinical trial. The primary endpoint variable was the renal survival time, defined as the time from inclusion in the study to the treatment failure endpoint of death or euthanasia or need for administration of parenteral fluids related to renal failure. RESULTS: No benefit of benazepril versus placebo was detected for renal survival time in all dogs; median (95% confidence interval (CI)) survival times were 305 (53-575) days in the benazepril group and 287 (152-not available) in the placebo group (P = .53). Renal survival times were not significantly longer with benazepril compared to placebo for subgroups: hazard ratios (95% CI) were 0.50 (0.21-1.22) with P = .12 for initial urine protein-to-creatinine ratio (UPC) >0.5, and 0.38 (0.12-1.19) with P = .080 for initial UPC >0.5 plus plasma creatinine ≤440 µmol/L. Proteinuria, assessed from the UPC, was significantly (P = .0032) lower after treatment with benazepril compared to placebo. There were no significant differences between groups for clinical signs or frequencies of adverse events. CONCLUSIONS AND CLINICAL RELEVANCE: Benazepril significantly reduced proteinuria in dogs with CKD. Insufficient numbers of dogs were recruited to allow conclusions on survival time.

A kitchen-based intervention to improve nutritional intake from school lunches in children aged 12-16 years.

BACKGROUND: School lunches potentially provide an important source of nutrients for children, although studies have shown that their food choices are not always associated with health benefits. The present study aimed to evaluate the effects of a kitchen-based intervention on intake from school lunches undertaken in 2005. METHODS: The three-phase study comprised a pre-intervention observation, the intervention itself and a post-intervention observation. Children aged 12-16 years attending a large, inner-city, secondary school in London were invited to participate. The intervention consisted of small, practical changes to the school menu with the purpose of reducing total and saturated fat and increasing fruit and vegetable consumption. Intake was evaluated using a weighed technique. RESULTS: One hundred and eighty and 198 children participated in the pre- and post-intervention phases, respectively. After the intervention, a significant reduction was observed in mean (SD) intake of total fat [44% (8%) versus 40% (9%) total energy, P < 0.01] and of saturated fat [13% (6%) versus 10% (6%), P < 0.01]. The children also ate significantly more fruit and vegetables [12.0 (10.4) g versus 30.0 (30.5) g total weight, P < 0.001]. However, after the intervention, the mean intakes of total and saturated fat, fruit and vegetables were still significantly below the Caroline Walker Trust guidelines for school lunches. CONCLUSIONS: The present study shows that total and saturated fat and fruit and vegetable intake from school lunches can be significantly improved by a short, kitchen-based intervention. Although the benefits were limited, the results support further work in this area.

An estimate of phytate intake and molar ratio of phytate to zinc in the diet of the people in the United Kingdom.

OBJECTIVE: To estimate the phytate intake and molar ratio of phytate to zinc in the diet of the people in the United Kingdom. DESIGN: Tables of the phytate content of foods were developed from twenty-eight published and unpublished studies. They were then applied to the nutrient databank of the National Diet and Nutrition Survey (NDNS). The study is a retrospective analysis of data on daily consumption of foods and drinks from the NDNS of children, adolescents, adults and the elderly based on 4-7 d weighed intakes. SUBJECTS: A total of 6786 British participants aged 1.5 years and above, who participated in the NDNS, 1992-2001. SETTING: England, Scotland and Wales. RESULTS: The median daily intakes of phytate for children, adolescents, adults and the elderly population were 496, 615, 809 and 629 mg/d, respectively. Although there were differences in phytate intakes between men and women, and for children, adolescents and elderly populations, after adjusting for differences in energy intake, there was no significant variation. The median phytate-to-zinc molar ratios for children, adolescents, adults and the elderly population were 11.8, 10.4, 9.7 and 8.7, respectively. Overall, the main sources of phytate were cereal and cereal products (e.g. breakfast cereals and breads), vegetables, potatoes and savoury snacks (e.g. chips and crisps), hot drinks and miscellaneous foods (e.g. commercial toddler foods and drinks, chocolate and soups), fruits and nuts. CONCLUSIONS: The present study estimated the dietary intake of phytate and the phytate-to-zinc molar ratio of the diet of the UK population, which can be used for estimating the average requirement of zinc. Further research should focus on the completion and validation of the tables of phytate content of UK foods, to assess (and if necessary improve) the accuracy and precision of these findings.

Postoperative extended-volume external-beam radiation therapy in high-risk esophageal cancer patients: a prospective experience.

BACKGROUND AND PURPOSE: Extended-volume external-beam radiation therapy (RT) following esophagectomy is controversial. The present prospective study evaluates the feasibility of extended-volume RT treatment in high-risk esophagectomy patients with a cervical anastomosis receiving postoperative combined chemoradiation therapy. PATIENTS AND METHODS: From 2001 to 2006, 15 patients with resected esophageal cancer were prospectively accrued to this pilot study to evaluate the adverse effects of extended-volume RT. Postoperative management was carried out at London Regional Cancer Program. Eligibility criteria were pathology-proven esophageal malignancy (T3-4, N0-1), disease amenable to surgical resection, and esophagectomy with or without resection margin involvement. Patients with distant metastases (M1) and patients treated with previous RT were excluded. All 15 study patients received 4 cycles of 5-fluorouracil-based chemotherapy. External-beam RT was conducted using conformal computed tomography planning, with multi-field arrangement tailored to the pathology findings, with coverage of a clinical target volume encompassing the primary tumour bed and the anastomotic site in the neck. The radiation therapy dose was 50.40 Gy at 1.8 Gy per fraction. The RT was delivered concurrently with the third cycle of chemotherapy. The study outcomes-disease-free survival (DFS) and overall survival (OS)-were calculated by the Kaplan-Meier method. Treatment-related toxicities were assessed using the U.S. National Cancer Institute's Common Toxicity Criteria. RESULTS: The study accrued 10 men and 5 women of median age 64 years (range: 48-80 years) and TNM stages T3N0 (n = 1), T2N1 (n = 2), T3N1 (n = 11), and T4N1 (n = 1). Histopathology included 5 adenocarcinomas and 10 squamous-cell carcinomas. Resection margins were clear in 10 patients. The median follow-up time was 19 months (range: 3.5-53.4 months). Before radiation therapy commenced, delay in chemotherapy occurred in 20% of patients, and dose reduction was required in 13.3%. During the concurrent chemoradiation therapy phase, 20% of the patients experienced chemotherapy delay, and 6.6% experienced dose reduction. No patient experienced treatment-related acute and chronic esophagitis above grade 2. Disease recurred in 40% of the patients (6/15), and median time to relapse was 24 months. No tumour recurred at the anastomotic site. The median DFS was 23 months, and the median OS was 21 months. CONCLUSIONS: Extended-volume external-beam RT encompassing the tumour bed and the anastomotic site is feasible and safe for high-risk T3-4, N0-1 esophageal cancer patients after esophagectomy.

Assessing the prognostic significance of transrectal ultrasound extracapsular extension in prostate cancer.

AIMS: To determine the prognostic value of transrectal ultrasound (TRUS)-detected extraprostatic disease for prostate cancer in patients receiving radical external-beam radiation therapy (EBRT). MATERIALS AND METHODS: A chart review of 181 patients treated with radical EBRT for prostate cancer was conducted. All patients underwent TRUS assessment by one radiologist. The median radiation dose delivered to the prostate was 66 Gy (range 53-70 Gy) in 33 fractions (range 20-39 fractions). Median follow-up time for all patients was 6.5 years. Sixty-four (35%) out of 181 patients were found to have extracapsular disease on TRUS. Clinical relapse was defined as the first occurrence of either salvage hormonal therapy administration by the treating oncologist or clinical, radiological, and/or pathologic evidence of recurrent or progressive disease. In terms of biochemical failure, two prognostic variable analyses were carried out using both the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus guidelines and the Houston definition of biochemical failure. The primary end point for the prognostic variable analyses was time to first clinical or biochemical failure (CBF). RESULTS: For time to CBF using the ASTRO consensus guidelines for biochemical failure, univariable analysis revealed that the prostate-specific antigen (PSA) (P = 0.018), clinical T stage (P = 0.002), Gleason score (P = 0.021), adjuvant hormonal therapy (P = 0.032) and TRUS T staging (P = 0.0001) were statistically significant prognostic factors. On multivariable analysis, clinical T stage (P = 0.051) was of borderline statistical significance, whereas PSA (P = 0.036), TRUS T stage (P = 0.0002) and adjuvant hormonal therapy (P = 0.015) were found to be independent prognostic factors. For time to CBF using the Houston definition of biochemical failure, univariable analysis revealed that PSA (P = 0.001), Gleason score (P = 0.026) and prostate volume (P = 0.013) were statistically significant prognostic factors. On multivariable analysis, PSA (P = 0.002), Gleason score (P = 0.012), and adjuvant hormonal therapy (P = 0.041) were found to be independent prognostic factors. TRUS T staging was not found to be independently significant. CONCLUSIONS: A clear role for TRUS staging as an independent prognostic factor, in the setting of other more established variables, such as Gleason grade, PSA, and digital rectal examination (DRE) T stage, was not confirmed in this study, population.

Isotopic homogeneity of iron in the early solar nebula.

The chemical and isotopic homogeneity of the early solar nebula, and the processes producing fractionation during its evolution, are central issues of cosmochemistry. Studies of the relative abundance variations of three or more isotopes of an element can in principle determine if the initial reservoir of material was a homogeneous mixture or if it contained several distinct sources of precursor material. For example, widespread anomalies observed in the oxygen isotopes of meteorites have been interpreted as resulting from the mixing of a solid phase that was enriched in 16O with a gas phase in which 16O was depleted, or as an isotopic 'memory' of Galactic evolution. In either case, these anomalies are regarded as strong evidence that the early solar nebula was not initially homogeneous. Here we present measurements of the relative abundances of three iron isotopes in meteoritic and terrestrial samples. We show that significant variations of iron isotopes exist in both terrestrial and extraterrestrial materials. But when plotted in a three-isotope diagram, all of the data for these Solar System materials fall on a single mass-fractionation line, showing that homogenization of iron isotopes occurred in the solar nebula before both planetesimal accretion and chondrule formation.

The formation of chondrules at high gas pressures in the solar nebula.

High-precision magnesium isotope measurements of whole chondrules from the Allende carbonaceous chondrite meteorite show that some aluminum-rich Allende chondrules formed at or near the time of formation of calcium-aluminum-rich inclusions and that some others formed later and incorporated precursors previously enriched in magnesium-26. Chondrule magnesium-25/magnesium-24 correlates with [magnesium]/[aluminum] and size, the aluminum-rich, smaller chondrules being the most enriched in the heavy isotopes of magnesium. These relations imply that high gas pressures prevailed during chondrule formation in the solar nebula.