Radiological characterisation of graphite components in Advanced Gas-cooled Reactor cores.

As the Advanced Gas-cooled Reactors approach the end of generation, research and characterisation are required to support the decommissioning strategy. Radiological data for AGR graphite are negligible and the radiological inventory of the AGR core and other graphite components rely on activation modelling. This is the first study of C-14 activity and its release behaviour in AGR core graphite and its associated carbonaceous deposits and provides valuable information that can support decommissioning activities. In combination with corresponding studies on Magnox core graphite, significant understanding is attained on the main C-14 precursors in the graphite and the deposits. In addition, this study reports C-14, H-3 and gamma spectrometry data on AGR graphite fuel sleeves. This is a waste stream that is currently stored in heavily engineered stores at a significant cost. The data indicate that alternative storage and disposal options with a lower environmental and financial impact are worth considering.

Effects of weight-neutral approaches compared with traditional weight-loss approaches on behavioral, physical, and psychological health outcomes: a systematic review and meta-analysis.

CONTEXT: Weight-neutral approaches for health are emerging therapeutic alternatives to traditional weight-loss approaches. The existing literature base comparing these approaches has not yet been systematically evaluated by a meta-analysis. OBJECTIVE: This review aims to determine if weight-neutral approaches are valid alternatives to weight-loss approaches for improving physical, psychological, and behavioral health outcomes. DATA SOURCES: Embase, Scopus, PsycINFO, PubMed, CINAHL, and the University of Queensland Library databases were searched. STUDY SELECTION: Peer-reviewed, experimental, or quasi-experimental studies that included weight-neutral and weight-loss arms and reported physical, psychological, or behavioral outcomes were eligible. A total of 525 studies were identified through initial database searches, with 10 included in the final analysis after exclusion criteria were applied. DATA EXTRACTION: Screening and eligibility assessment of studies followed the PRISMA protocol. The following outcomes were extracted: weight, body mass index, lipid and glucose variables, blood pressure, eating behavior, self-esteem, depression, quality of life, physical activity, and diet quality. DATA ANALYSIS: Studies were graded per the National Health and Medical Research Council (NHMRC) level-of-evidence tool and the Academy of Nutrition and Dietetics quality-evaluation tool. Effect sizes were examined as a meta-analysis of standardized and mean differences using a random-effects inverse-variance model with 95%CIs. Practice recommendations for each outcome were graded per NHMRC body-of-evidence guidelines. CONCLUSIONS: Weight-neutral approaches resulted in greater improvement in bulimia (P = 0.02), but no significant differences were observed for any other outcome. Weight-neutral approaches may be as effective as weight-loss methods for improving physical, psychological, and behavioral outcomes. Limitations include inconsistent definitions of both approaches and variable time frames of follow-up.

Risk of Renal Cell Carcinoma Among Kidney Transplant Recipients in the United States.

Renal cell carcinoma (RCC) is a common malignancy following kidney transplantation. We describe RCC risk and examine RCC risk factors among US kidney recipients (1987-2010). The Transplant Cancer Match Study links the US transplant registry with 15 cancer registries. Standardized incidence ratios (SIRs) were used to compare RCC risk (overall and for clear cell [ccRCC] and papillary subtypes) to the general population. Associations with risk factors were assessed using Cox models. We identified 683 RCCs among 116 208 kidney recipients. RCC risk was substantially elevated compared with the general population (SIR 5.68, 95% confidence interval 5.27-6.13), especially for papillary RCC (SIR 13.3 versus 3.98 for ccRCC). Among kidney recipients, RCC risk was significantly elevated for blacks compared to whites (hazard ratio [HR] 1.50) and lower in females than males (HR 0.56). RCC risk increased with prolonged dialysis preceding transplantation (p-trend < 0.0001). Risk was variably associated for RCC subtypes with some medical conditions that were indications for transplantation: ccRCC risk was reduced with polycystic kidney disease (HR 0.54), and papillary RCC was increased with hypertensive nephrosclerosis (HR 2.02) and vascular diseases (HR 1.86). In conclusion, kidney recipients experience substantially elevated risk of RCC, especially for papillary RCC, and multiple factors contribute to these cancers.

Comparison of Cancer Diagnoses Between the US Solid Organ Transplant Registry and Linked Central Cancer Registries.

US transplant centers are required to report cancers in transplant recipients to the transplant network. The accuracy and completeness of these data, collected in the Scientific Registry of Transplant Recipients (SRTR), are unknown. We compared diagnoses in the SRTR and 15 linked cancer registries for colorectal, liver, lung, breast, prostate and kidney cancers; melanoma; and non-Hodgkin lymphoma (NHL). Among 187 384 transplants, 9323 cancers were documented in the SRTR or cancer registries. Only 36.8% of cancers were in both, with 47.5% and 15.7% of cases additionally documented solely in cancer registries or the SRTR, respectively. Agreement between the SRTR and cancer registries varied (kappa = 0.28 for liver cancer and kappa = 0.52-0.66 for lung, prostate, kidney, colorectum, and breast cancers). Upon evaluation, some NHLs documented only in cancer registries were identified in the SRTR as another type of posttransplant lymphoproliferative disorder. Some SRTR-only cases were explained by miscoding (colorectal cancer instead of anal cancer, metastases as lung or liver cancers) or missed matches with cancer registries, partly due to recipients' outmigration from catchment areas. Estimated sensitivity for identifying cancer was 52.5% for the SRTR and 84.3% for cancer registries. In conclusion, SRTR cancer data are substantially incomplete, limiting their usefulness for surveillance and research.

Determination of the photolysis rate coefficient of monochlorodimethyl sulfide (MClDMS) in the atmosphere and its implications for the enhancement of SO2 production from the DMS + Cl2 reaction.

In this work, the photolysis rate coefficient of CH3SCH2Cl (MClDMS) in the lower atmosphere has been determined and has been used in a marine boundary layer (MBL) box model to determine the enhancement of SO2 production arising from the reaction DMS + Cl2. Absorption cross sections measured in the 28000-34000 cm(-1) region have been used to determine photolysis rate coefficients of MClDMS in the troposphere at 10 solar zenith angles (SZAs). These have been used to determine the lifetimes of MClDMS in the troposphere. At 0° SZA, a photolysis lifetime of 3-4 h has been obtained. The results show that the photolysis lifetime of MClDMS is significantly smaller than the lifetimes with respect to reaction with OH (≈ 4.6 days) and with Cl atoms (≈ 1.2 days). It has also been shown, using experimentally derived dissociation energies with supporting quantum-chemical calculations, that the dominant photodissocation route of MClDMS is dissociation of the C-S bond to give CH3S and CH2Cl. MBL box modeling calculations show that buildup of MClDMS at night from the Cl2 + DMS reaction leads to enhanced SO2 production during the day. The extra SO2 arises from photolysis of MClDMS to give CH3S and CH2Cl, followed by subsequent oxidation of CH3S.

Study of 2-H-heptafluoropropane and its thermal decomposition using UV photoelectron spectroscopy and ab initio molecular orbital calculations.

The thermal decomposition of 2-H-heptafluoropropane, CF(3)CHFCF(3), at low pressure, heavily diluted in argon, has been studied over the temperature range 600-2000 degrees C using photoelectron spectroscopy. Comparison of the results obtained has been made with results of recent electronic structure calculations of possible decomposition pathways and results of a shock tube study. The most favored reaction thermodynamically, to produce CF(3)CF=CF(2) + HF, is found to be the main decomposition reaction at lower temperatures, 600-900 degrees C. At higher temperatures, 900-1200 degrees C, the decomposition reaction to give C(2)F(4) + CF(3)H was found to become important. No evidence for CF(3)CHFCF(3) --> CF(3)CHF + CF(3), a reaction expected to be important from a shock tube study, performed at much higher pressures, or for CF(3)CHFCF(3) --> CF(3)CF + CF(3)H was obtained, although for the latter reaction it is likely that CF(3)CF converts into C(2)F(4) under the conditions used before photoionization, in the ionization region of the photoelectron spectrometer. At higher temperatures C(3)F(6) decomposes to C(2)F(4) + CF(2), and C(2)F(4) decomposes to CF(2). Ab initio calculations have been performed of the adiabatic and vertical ionization energies of possible primary pyrolysis products to assist assignment of the photoelectron spectra recorded for heated flowing gas samples. A comparison is made between the threshold photoelectron spectrum and the photoelectron spectrum of CF(3)CF=CF(2).

Study of pentafluoroethane and its thermal decomposition using UV photoelectron spectroscopy and ab initio molecular orbital calculations.

The UV photoelectron spectrum of CF(3)CHF(2) has been recorded and assigned using EOM-CCSD calculations. For the first band, the adiabatic ionization energy (AIE) and vertical ionization energy (VIE) have been measured as (12.71 +/- 0.05) and (13.76 +/- 0.02) eV, respectively. The measured AIE is higher than the recommended value from state-of-the-art ab initio calculations of (12.26 +/- 0.02) eV because of a large geometry change on ionization, mainly arising from a significant increase in the C-C bond length, which results in poor Franck-Condon factors in the adiabatic region. The experimental VIE also shows poor agreement with the computed value of 14.05 +/- 0.06 eV because, in the higher energy region of the first photoelectron band, dissociation of CF(3)CHF(2)(+) to CHF(2)(+) + CF(3) occurs. This has a calculated thermodynamic onset of (12.89 +/- 0.20) eV. Recommendations are made for the heats of formation, DeltaH(f,298)(slashed circle), of CF(3)CHF(2) and CF(3)CHF(2)(+), based on the results of the ab initio calculations. Pyrolysis of flowing CF(3)CHF(2) diluted in argon shows evidence of production of C(2)F(4) and HF at lower temperatures and CF(2) and CF(3)H at higher temperatures. The relative temperature dependence of the observed photoelectron bands associated with these molecules is interpreted in terms of two decomposition reactions of CF(3)CHF(2) as well as the reaction C(2)F(4) --> 2CF(2).

Methodological innovations in data gathering: newborn screening linkage with live births records, Michigan, 1/2007-3/2008.

OBJECTIVE: To match Michigan birth and newborn screening records to identify and follow-up potentially unscreened infants, assess data quality, and demonstrate the utility of Link Plus linkage software for matching MCH related administrative datasets. METHODS: Birth and newborn screening records maintained by the Michigan Department of Community Health from January 2007 through March 2008 were used in this study. Link Plus, a freely-available probabilistic record linkage software program developed at the Centers for Disease Control and Prevention, was used to match records. Linkage performance was assessed by the linkage success rate (percentage of valid matches). Follow-up of un-matched records was conducted by the Michigan Newborn Screening Follow-up Program. RESULTS: Nearly all (99.2%) of the 142,178 birth records included in this study were successfully matched to newborn screening records. Following a transition to a web-based electronic birth certificate system and inclusion of a newborn screening card identification number on the birth record in 2008, the linkage success rate increased to 99.6% based on analysis of approximately 18,000 records. Of approximately 600 un-matched records, nearly half had received a newborn screen. Approximately 8% of un-matched records were due to parental refusal of newborn screening. Nine children received an initial screen as a result of this study; one was confirmed as having sickle cell trait. CONCLUSIONS: We have demonstrated that a freely available record linkage software, Link Plus, can be used to successfully match records of MCH databases thereby providing an opportunity for further research and quality assurance investigations.

The use of orthopaedic POSSUM as an audit tool for fractured neck of femur.

In this prospective study, 230 patients who were operated on for a fractured neck of femur were evaluated using the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM). We observed 25 deaths (10.9%) and 95 patients had a post-operative complication (41.3%). The orthopaedic POSSUM equations yielded an overall predicted mortality of 21 patients and morbidity in 106 patients. This gave observed to expected (O:E) ratios of 1.19 and 0.95 respectively meaning that POSSUM agreed well with the observed mortality and morbidity. We concluded that POSSUM accurately predicts mortality and morbidity in patients with femoral neck fractures and when used as an audit tool would provide a fairer system of comparison and would allow an unbiased interpretation of results when changes in patient management are made.

The application of dermatotraction for primary skin closure.

Management of an open wound is a problem frequently encountered in the treatment of fractures. Skin grafting, rotational flaps, free flaps, and healing by secondary intention add a considerable amount of morbidity and cost to the patient. Therefore, it is ideal to obtain primary closure when possible. This communication describes a technique that uses spinal needles, using towel clips and the natural stretching ability of the skin to enable primary closure of wounds. The technique described uses dermatotraction to stretch the skin is a cost-effective way to achieve primary closure of large wounds with supplies that are readily available in every operating room.

An assessment of the POSSUM system in orthopaedic surgery.

We describe the development and validation of a scoring system for auditing orthopaedic surgery. It is a minor modification of the POSSUM scoring system widely used in general surgery. The orthopaedic POSSUM system which we have developed gives predictions for mortality and morbidity which correlate well with the observed rates in a sample of 2326 orthopaedic operations over a period of 12 months.

Fluorescence-based screening of asymmetric acylation catalysts through parallel enantiomer analysis. Identification of a catalyst for tertiary alcohol resolution.

A technique for high-throughput screening of kinetic resolution catalysts is reported. The method relies on carrying simultaneous kinetic resolutions in a multiwell plate format wherein each well contains a unique catalyst and a small amount of a pH-activated fluorescent sensor (3). By conducting experiments such that each catalyst is evaluated in parallel in the presence of each isolated enantiomer, an indication of catalyst activity is obtained on a per enantiomer basis. Catalysts that are highly active for one enantiomer but modestly active for another are then reevaluated in conventional kinetic resolutions. From these screens, a highly selective (k(rel) = 46) pentapeptide (4) was obtained for a model secondary alcohol (1). In addition, peptide 10 was found to afford excellent selectivities (k(rel) > 20) for a number of alcohol substrates (9a-9f) in the traditionally challenging tertiary class.

Selection of enantioselective acyl transfer catalysts from a pooled peptide library through a fluorescence-based activity assay: an approach to kinetic resolution of secondary alcohols of broad structural scope.

An assay employing a fluorescently labeled split and pool peptide library has been applied to the discovery of a new class of octapeptide catalysts for the kinetic resolution of secondary alcohols. A highly diverse library of peptide-based catalysts was synthesized on solid-phase synthesis beads such that each individual bead was co-functionalized with (i) a uniform loading of a pH-sensitive fluorophore and (ii) a unique peptide-based catalyst. The library was then screened for activity in acylation reactions employing (+/-)-sec-phenylethanol as the substrate and acetic anhydride as the acylation agent. From the most active catalysts, a lead peptide (4) was identified that provides a selectivity-factor (k(rel)) of 8.2 upon resynthesis and evaluation under homogeneous conditions. A "directed" second-generation split and pool peptide library was synthesized such that the new peptide sequences in the library were biased toward the lead structure. Random samples of the second generation library were screened in single bead assays that revealed several new peptide-based catalysts that afford improved selectivities in kinetic resolutions. Peptide catalyst 13 proves effective for the kinetic resolution of sec-phenylethanol (k(rel) = 20), as well as eight other secondary alcohols of a broad substrate scope (k(rel) = 4 to >50).

A comparison of the codeswitching patterns of aphasic and neurologically normal bilingual speakers of English and Spanish.

Conversational discourse samples were obtained from four aphasic and four neurologically normal Hispanic bilinguals in monolingual English, monolingual Spanish, and bilingual contexts to identify codeswitching patterns. Analysis of the samples based on the Matrix Language Frame (MLF) Model (Myers-Scotton, 1993a) revealed consistent matching of the language context by the aphasic and normal subjects. The aphasic subjects demonstrated a greater frequency of MLF constituents and codeswitching patterns not evident in the speech samples of the normal subjects. Results suggest an increased dependence on both languages for communication following neurological impairment.

Comparison of individual surgeon's performance. Risk-adjusted analysis with POSSUM scoring system.

UNLABELLED: Comparison of outcome after colorectal resection among different surgeons is difficult. Crude rates of morbidity and mortality can be misleading because such rates make no allowance for differences in case mix and fitness of patients. AIM: The aim of this study was to compare outcome among five surgeons by means of the simple, well-validated scoring system POSSUM for risk-adjusted analysis. METHODS: A total of 438 patients were studied prospectively. Each patient underwent colorectal resection by one of the five surgeons. Demographic details, operative procedure, and postoperative course were recorded, and physiologic and operative severity scores were determined. Risk of morbidity and mortality was calculated for each patient. RESULTS: Incidence of morbidity varied sharply among the five surgeons, from 13.6 to 30.6 percent, and the 30-day mortality varied from 4.5 to 6.9 percent. However, application of POSSUM to allow risk-adjusted analysis of the data demonstrated that the incidence of morbidity and mortality predicted by POSSUM based on patients physiologic and operative risks factors was very similar to the observed outcome for each surgeon. CONCLUSION: Direct comparison of individual surgeon's performance based on crude rates of morbidity and mortality can be misleading. Risk-adjusted analysis allows more meaningful comparison.

Octreotide in the control of post-sclerotherapy bleeding from oesophageal varices, ulcers and oesophagitis.

Bleeding from oesophageal varices, oesophageal ulcers or oesophagitis is occasionally massive and difficult to control. Octreotide, a synthetic analogue of somatostin lowers portal pressure and collateral blood flow including that through varices, increases lower oesophageal sphincter pressure, and inhibits the gastric secretion of acid as well as pepsin. Our current experience suggests it is effective in controlling acute variceal haemorrhage. Therefore we have examined the efficacy of octreotide in the control of post-sclerotherapy bleeding from oesophageal varices, oesophageal ulcers and oesophagitis. During the study period 77 patients experienced a significant gastrointestinal bleed (blood pressure < 100 mm Hg, pulse > 100 beats per min or the need to transfuse 2 or more units of blood to restore the hemoglobin level) following injection sclerotherapy of oesophageal varices. The source of bleeding was varices in 42 patients, oesophageal ulcers in 31 and oesophagitis in 4. All patients received a continuous intravenous infusion of octreotide (50 micrograms/h) for between 40-140h. If bleeding was not controlled in the first 12h after commencing octreotide hourly bolus doses (50 micrograms) for 24h were superimposed on the continuous infusion. Haemorrhage was successfully controlled by an infusion of octreotide in 38 of the 42 patients with bleeding from varices, in 30 of 31 patients with oesophageal ulceration, and all patients with oesophagitis. In the 1 patient with persistent bleeding from oesophageal ulceration and in 2 of the 4 with continued haemorrhage from varices, haemostasis was achieved by hourly boluses of 50 micrograms octreotide for 24h in addition to the continuous infusion. No major complications were associated with octreotide administration. The results of this study clearly indicate that octreotide is a safe and effective treatment for the control of severe haemorrhage after technically successful injection of sclerotherapy.

The value of guidelines in a breast screening service.

The use of agreed guidelines in the management of common surgical and medical conditions has received much attention and enjoys varying degrees of support. In May 1992 the UK Breast Screening Programme produced guidelines with the intention of providing criteria for all units to attempt to achieve. We have investigated these guidelines as a means of comparative audit and stimulus for change. Two units were compared, one in a teaching centre and the other in a district general hospital. Although both units performed for the most part within the guidelines, areas where improvement could be made were identified and measures to correct deficiencies taken. This resulted in improved performance in those areas. The study demonstrates that guidelines can have considerable benefit in helping to identify problems in the provision of care and introducing measures to improve the situation.

Risk-adjusted analysis of surgeon performance: a 1-year study.

A 1-year prospective analysis was undertaken of all non-day-case general surgery in a district general hospital. Using the Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM) scoring system 3004 patients were assessed. From the predictions of mortality and morbidity so obtained, a quality measure, the ratio of observed to expected numbers of deaths and complications (O:E ratio) was determined for each surgeon, both overall and within specialty zones. The present study demonstrates the serious hazard in using 'raw' uncorrected mortality and morbidity statistics to compare surgeon performance. Mortality rates varied from 1.0 to 4.9 per cent whereas O:E ratios ranged from 0.83 to 1.06; morbidity rates varied from 5.3 to 12.6 per cent with O:E ratios 0.86-1.02. Great misunderstanding may result from the publication of surgeon or hospital 'league tables'. The present study demonstrates a technique that might allow surgeon performance to be monitored adequately and accurately.