Nickel-catalyzed ester carbonylation promoted by imidazole-derived carbenes and salts.

Millions of tons of acetyl derivatives such as acetic acid and acetic anhydride are produced each year. These building blocks of chemical industry are elaborated into esters, amides, and eventually polymer materials, pharmaceuticals, and other consumer products. Most acetyls are produced industrially using homogeneous precious metal catalysts, principally rhodium and iridium complexes. We report here that abundant nickel can be paired with imidazole-derived carbenes or the corresponding salts to catalyze methyl ester carbonylation with turnover frequency (TOF) exceeding 150 hour-1 and turnover number (TON) exceeding 1600, benchmarks that invite comparisons to state-of-the-art rhodium-based systems and considerably surpass known triphenylphosphine-based nickel catalysts, which operate with TOF ~7 hour-1 and TON ~100 under the same conditions.

Shoulder Pain Diagnosis, Treatment and Referral Guidelines for Primary, Community and Intermediate Care.

These care pathway guidelines for the shoulder have been written in collaboration with the NHS Evidence Based Interventions (EBI) programme. The EBI programme is a partnership between the Academy of Medical Royal Colleges, NHS Clinical Commissioners, the National Institute for Health and Care Excellence, as well as NHS England and Improvement.

The Clinical Utility of Point-of-Care Tests for Influenza in Ambulatory Care: A Systematic Review and Meta-analysis.

BACKGROUND: Point-of-care tests (POCTs) for influenza are diagnostically superior to clinical diagnosis, but their impact on patient outcomes is unclear. METHODS: A systematic review of influenza POCTs versus usual care in ambulatory care settings. Studies were identified by searching six databases and assessed using the Cochrane risk of bias tool. Estimates of risk ratios (RR), standardised mean differences, 95% confidence intervals and I2 were obtained by random effects meta-analyses. We explored heterogeneity with sensitivity analyses and meta-regression. RESULTS: 12,928 citations were screened. Seven randomized studies (n = 4,324) and six non-randomized studies (n = 4,774) were included. Most evidence came from paediatric emergency departments. Risk of bias was moderate in randomized studies and higher in non-randomized studies. In randomized trials, POCTs had no effect on admissions (RR 0.93, 95% CI 0.61-1.42, I2 = 34%), returning for care (RR 1.00 95% CI = 0.77-1.29, I2 = 7%), or antibiotic prescribing (RR 0.97, 95% CI 0.82-1.15, I2 = 70%), but increased prescribing of antivirals (RR 2.65, 95% CI 1.95-3.60; I2 = 0%). Further testing was reduced for full blood counts (FBC) (RR 0.80, 95% CI 0.69-0.92 I2 = 0%), blood cultures (RR 0.82, 95% CI 0.68-0.99; I2 = 0%) and chest radiography (RR 0.81, 95% CI 0.68-0.96; I2 = 32%), but not urinalysis (RR 0.91, 95% CI 0.78-w1.07; I2 = 20%). Time in the emergency department was not changed. Fewer non-randomized studies reported these outcomes, with some findings reversed or attenuated (fewer antibiotic prescriptions and less urinalysis in tested patients). CONCLUSIONS: Point-of-care testing for influenza influences prescribing and testing decisions, particularly for children in emergency departments. Observational evidence shows challenges for real-world implementation.

Classification of spent reactor fuel for nuclear forensics.

In this paper we demonstrate the use of pattern recognition and machine learning techniques to determine the reactor type from which spent reactor fuel has originated. This has been done using the isotopic and elemental measurements of the sample and proves to be very useful in the field of nuclear forensics. Nuclear materials contain many variables (impurities and isotopes) that are very difficult to consider individually. A method that considers all material parameters simultaneously is advantageous. Currently the field of nuclear forensics focuses on the analysis of key material properties to determine details about the materials processing history, for example, utilizing known half-lives of isotopes can determine when the material was last processed (Stanley, F. E. J. Anal. At. Spectrom. 2012, 27, 1821; Varga, Z.; Wallenius, M.; Mayer, K.; Keegan, E.; Millet, S. Anal. Chem. 2009, 81, 8327-8334). However, it has been demonstrated that multivariate statistical analysis of isotopic concentrations can complement these method and are able to make use of a greater level of information through dimensionality reduction techniques (Robel, M.; Kristo, M. J. J. Environ. Radioact. 2008, 99, 1789-1797; Robel, M.; Kristo, M. J.; Heller, M. A. Nuclear Forensic Inferences Using Iterative Multidimensional Statistics. In Proceedings of the Institute of Nuclear Materials Management 50th Annual Meeting, Tucson, AZ, July 2009; 12 pages; Nicolaou, G. J. Environ. Radioact. 2006, 86, 313-318; Pajo, L.; Mayer, K.; Koch, L. Fresenius' J. Anal. Chem. 2001, 371, 348-352). There has been some success in using such multidimensional statistical methods to determine details about the history of spent reactor fuel (Robel, M.; Kristo, M. J. J. Environ. Radioact. 2008, 99, 1789-1797). Here, we aim to expand on these findings by pursuing more robust dimensionality reduction techniques based on manifold embedding which are able to better capture the intrinsic data set information. Furthermore, we demonstrate the use of a number of classification algorithms to reliably determine the reactor type in which a spent fuel material has been irradiated. A number of these classification techniques are novel applications in nuclear forensics and expand on the existing knowledge in this field by creating a reliable and robust classification model. The results from this analysis show that our techniques have been very successful and further ascertain the excellent potential of these techniques in the field of nuclear forensics at least with regard to spent reactor fuel.

The molecular action of the novel insecticide, Pyridalyl.

Pyridalyl is a recently discovered insecticide that exhibits high insecticidal activity against Lepidoptera and Thysanoptera. Pyridalyl action requires cytochrome P450 activity, possibly for production of a bioactive derivative, Pyridalyl metabolism being prevented by general P450 inhibitors. Apoptosis is apparently not involved in the cytotoxicity. Continuous culture of Spodoptera frugiperda Sf21 cells in sub-lethal doses of Pyridalyl, results in a Pyridalyl-resistant cell line. Probing the molecular action of Pyridalyl by comparison of the proteomes of Pyridalyl-resistant and -susceptible cell lines, revealed differential expression of a number of proteins, including the up-regulation of thiol peroxiredoxin (TPx), in the resistant cells. Treatment of Bombyx mori larvae with Pyridalyl, followed by comparison of the midgut microsomal sub-proteome, revealed the up-regulation of three proteasome subunits. Such subunits, together with Hsp70 stress proteins, glyceraldehyde 3-phosphate dehydrogenases (GAPDHs) and thiol peroxiredoxin (TPx) were also up-regulated in the whole proteome of B. mori BM36 cells following treatment with the insecticide. The foregoing results lead to the hypothesis that cytochrome P450 action leads to an active Pyridalyl metabolite, which results in production of reactive oxygen species (ROS), that leads to damage to cellular macromolecules (e.g., proteins) and enhanced proteasome activity leads to increased protein degradation and necrotic cell death.

A quadrupole mass spectrometer for resolution of low mass isotopes.

The qualitative and quantitative identification of low mass isotopes in the mass range 1-6 u poses certain difficulties when attempting to achieve the required resolution with an instrument suitable for deployment within a process environment. Certain adjacent species present in the process sample (HT and D(2)) require a resolution greater than 930 to achieve an accurate measurement. We demonstrate here through simulation techniques that this level of performance required is unachievable using commercially available instruments. Using previously reported simulation techniques, this article demonstrates how the required performance for resolving the low mass isotopes can be achieved by a quadrupole mass spectrometer (QMS), which incorporates a quadrupole mass filter (QMF) constructed from hyperbolic electrodes and operated in zone 3 of the Mathieu stability diagram.

A mechanical comparison of the locking compression plate (LCP) and the low contact-dynamic compression plate (DCP) in an osteoporotic bone model.

OBJECTIVE: To determine if locking compression plates (LCP) are mechanically advantageous compared to low-contact dynamic compression plates (DCP) when used as a bridging plate in a synthetic model of osteoporotic bone. METHODS: Five synthetic bars (Synbone Osteoporotic bone) were initially tested in compression and the Young's modulus determined. It was found to be comparable to that of tibial cancellous bone in an 80-year-old woman; thus, the synthetic bars were deemed usable to simulate some properties of osteoporotic bone. Six bars were then instrumented with an 8-hole narrow large fragment DCP with six 4.5-mm cortical screws (placed in holes 1-3 and holes 6-8). Six bars were instrumented with a narrow 8-hole LCP using four 5-mm locking screws (placed in the 1st, 3rd, 6th, and 8th holes). In a third group, 6 synbone bars were instrumented with a narrow 8-hole large fragment DCP. Cortical screws were placed in holes 2-3 and holes 6-7. In holes 1 and 8, two 6.5 fully threaded cancellous screws were inserted. A 1-cm osteotomy was created in the Synbone at the center of each plate to represent a comminuted fracture. Initially, quasi-static testing was carried out on all specimens in compression to a maximum load of 450 N. Then 4-point bend tests were carried out in two planes (0 degrees and 90 degrees) with the maximum bending moment at 3.5 Nm. Finally, torsional testing was done to a maximum load of 3.5 Nm. The specimens were then cycled in axial compression 350 N at 5 Hz for 30,000 cycles. The static nondestructive tests were repeated. The slope of the load deformation curve indicated the relative stiffness of the construct. The slopes were determined pre- and postcycling and the loss of stiffness in each group compared. Statistical analysis was carried out using the paired t-test. The specimens were then loaded to failure in compression. RESULTS: There was no statistical difference in the stiffness of the LCP or in the osteotomy gap postcycling. All specimens in the DCP groups failed initial static testing in axial compression. No fatigue testing could be undertaken in this group. CONCLUSIONS: In a synthetic model, the LCP was mechanically superior to the DCP when used as a bridging plate and tested in axial compression.

Simulation of high- and low-resolution mass spectra for assessment of calibration methods.

Calibrating mixtures of residual gases in quadrupole mass spectrometry (QMS) can be difficult since low m/z ratios of molecular ions and their fragments result in overlap of signals especially in the lower mass regions. This causes problems in univariate calibration methods and encourages use of full spectral multivariate methods. Experimental assessment of regression methods has limitations since experimental sources of error can only be minimised and not entirely eliminated. A method of simulating full spectra at low and high resolution to accurate masses is described and these are then used for a calibration study of some popular linear regression methods [classical least squares regression (CLS), partial least squares (PLS), principal component regression (PCR)].