The application of inelastic neutron scattering to investigate the interaction of methyl propanoate with silica.

A modern industrial route for the manufacture of methyl methacrylate involves the reaction of methyl propanoate and formaldehyde over a silica-supported Cs catalyst. Although the process has been successfully commercialised, little is known about the surface interactions responsible for the forward chemistry. This work concentrates upon the interaction of methyl propanoate over a representative silica. A combination of infrared spectroscopy, inelastic neutron scattering, DFT calculations, X-ray diffraction and temperature-programmed desorption is used to deduce how the ester interacts with the silica surface.

The application of inelastic neutron scattering to explore the significance of a magnetic transition in an iron based Fischer-Tropsch catalyst that is active for the hydrogenation of CO.

An iron based Fischer-Tropsch synthesis catalyst is evaluated using CO hydrogenation at ambient pressure as a test reaction and is characterised by a combination of inelastic neutron scattering (INS), powder X-ray diffraction, temperature-programmed oxidation, Raman scattering, and transmission electron microscopy. The INS spectrum of the as-prepared bulk iron oxide pre-catalyst (hematite, α-Fe2O3) is distinguished by a relatively intense band at 810 cm(-1), which has previously been tentatively assigned as a magnon (spinon) feature. An analysis of the neutron scattering intensity of this band as a function of momentum transfer unambiguously confirms this assignment. Post-reaction, the spinon feature disappears and the INS spectrum is characterised by the presence of a hydrocarbonaceous overlayer. A role for the application of INS in magnetic characterisation of iron based FTS catalysts is briefly considered.

Haptoglobin testing in hemolysis: measurement and interpretation.

Haptoglobin is primarily produced in the liver and is functionally important for binding free hemoglobin from lysed red cells in vivo, preventing its toxic effects. Because haptoglobin levels become depleted in the presence of large amounts of free hemoglobin, decreased haptoglobin is a marker of hemolysis. Despite its ubiquity and importance, a paucity of literature makes testing difficult to interpret. This review highlights the many physiological roles that have been recently elucidated in the literature. Different methodologies have been developed for testing, including spectrophotometry, immunoreactive methods, and gel electrophoresis. These are covered along with their respective advantages and disadvantages. As there is no single gold standard for hemolysis, validation studies must rely on a combination of factors, which are reviewed in this article. Pitfalls and limitations of testing are also addressed. False positives can occur in improper specimen preparations, cirrhosis, elevated estrogen states, and hemodilution. False negatives can occur in hypersplenism and medications such as androgens and corticosteroids. Haptoglobin testing in the setting of inflammation is additionally discussed as interpretation can be difficult in this setting. Given the widespread use of haptoglobin testing, it is vital that clinicians and laboratory staff understand the principles and correct interpretation of this test.

Application of inelastic neutron scattering to studies of CO2 reforming of methane over alumina-supported nickel and gold-doped nickel catalysts.

The methane reforming reaction with carbon dioxide as the oxidant over alumina-supported nickel and gold-doped nickel catalysts is studied using a variety of techniques such as reaction testing, vibrational spectroscopy (inelastic neutron scattering (INS), Raman scattering and infrared absorption), temperature-programmed oxidation (TPO), transmission electron microscopy and X-ray powder diffraction. The quantities of retained carbon and hydrogen are determined by TPO and INS, respectively. Minimal hydrogen retention indicates these catalysts to be very efficient at cycling hydrogen. The relative partitioning of hydrogen within the reaction media is used to formulate a qualitative description of the reaction kinetics. The presence of the gold modifier does not appear to provide any improvement in catalyst performance under the specified reaction conditions.

Hb North York [beta 117(G19)His-->Asp]: a new beta chain hemoglobin variant.

Routine hemoglobin (Hb) analysis identified a new beta chain Hb variant in an Iranian woman, who otherwise had normal hematological indices. Sequence analysis demonstrated that the Hb variant was due to a missense mutation at amino acid codon 117 (CAC>GAC, His-->Asp) of the beta-globin gene.

Guidance for quality control practices and precision goals for CBCs based on IQMH patterns-of-practice survey.

INTRODUCTION: Effective medical laboratory quality management systems ensure confidence in analyzing and reporting accurate and reliable patient results. To guarantee quality assurance, each laboratory needs appropriate internal quality control (IQC) procedures to monitor their test systems. The Institute for Quality Management in Healthcare (IQMH) Centre for Proficiency Testing conducted a survey on quality control (QC) practices in routine hematology. METHODS: An online survey was sent to 184 Ontario laboratories performing complete blood counts (CBC) and leukocyte differentials. RESULTS: All participants used three levels of commercial QC for test system monitoring. Eighty percent of laboratories supplement with in-house patient QC. The frequency of QC analysis was variable based on: Manufacturer recommendations (80%) Parameter stability (25%) Clinical impact of incorrect results (21%) Number of samples potentially requiring retesting if there is a QC failure (11%). All laboratories used established QC rules and limits to monitor results. They utilized various methods in establishing limits including: Standard deviation of QC results (60%) Manufacturer precision goals (55%) Published precision goals (24%) IQMH allowable performance limits (APLs) (37%). CONCLUSION: Considerable variation in QC practices of Ontario laboratories was identified, and consensus practice recommendations and precision goals were developed to guide and standardize QC practice.

A multicenter trial of the effectiveness of zeta-globin enzyme-linked immunosorbent assay and hemoglobin H inclusion body screening for the detection of alpha0-thalassemia trait.

Routine laboratories use a hemoglobin H (HbH) screen to detect alpha-thalassemia carriers of fatal hemoglobin Bart's hydrops fetalis. This test is laborious and has sensitivity concerns. A commercial zeta-globin enzyme-linked immunosorbent assay (ELISA) is effective in detecting Southeast Asian (SEA) alpha-thalassemia. We present results of a study of the effectiveness of carrier detection of ELISA and a shortened HbH screen compared with gap polymerase chain reaction. ELISA was superior to the HbH screen for the SEA alpha0-thalassemia trait. The ELISA and H screen were equal for detection of all carriers encountered and combined were more effective than either test alone. A positive zeta-globin ELISA result is diagnostic of SEA alpha-thalassemia, and routine use of the zeta-globin ELISA in combination with a shortened HbH screen will improve the efficacy of prenatal screening for carriers of hemoglobin Bart's hydrops fetalis through improved detection and referral for follow-up DNA testing.

Calcium-phosphorus interactions at a nano-structured silicate surface.

Nano-structured calcium silicate (NCS), a highly porous material synthesized by controlled precipitation from geothermal fluids or sodium silicate solution, was developed as filler for use in paper manufacture. NCS has been shown to chemisorb orthophosphate from an aqueous solution probably obeying a Freundlich isotherm with high selectivity compared to other common environmental anions. Microanalysis of the products of chemisorption indicated there was significant change from the porous and nano-structured morphology of pristine NCS to fibrous and crystalline morphologies and non-porous detritus. X-ray diffraction analysis of the crystalline products showed it to be brushite, CaHPO42H2O, while the largely X-ray amorphous component was a mixture of calcium phosphates. A two-step mechanism was proposed for the chemisorption of phosphate from an aqueous solution by NCS. The first step, which was highly dependent on pH, was thought to be desorption of hydroxide ions from the NCS surface. This was kinetically favoured at lower initial pH, where the predominant form of phosphate present was H2PO(-)4, and led to decreased phosphorus uptake with increasing pH. The second step was thought to be a continuing chemisorption process after stabilization of the pH-value. The formation of brushite as the primary chemisorption product was found to be consistent with the proposed mechanism.

An In Situ XAS Study of the Cobalt Rhenium Catalyst for Ammonia Synthesis.

A cobalt rhenium catalyst active for ammonia synthesis at 400 °C and ambient pressure was studied using in situ XAS to elucidate the reducibility and local environment of the two metals during reaction conditions. The ammonia reactivity is greatly affected by the gas mixture used in the pre-treatment step. Following H2/Ar pre-treatment, a subsequent 20 min induction period is also observed before ammonia production occurs whereas ammonia production commences immediately following comparable H2/N2 pre-treatment. In situ XAS at the Co K-edge and Re LIII-edge show that cobalt initiates reduction, undergoing reduction between 225 and 300 °C, whereas reduction of rhenium starts at 300 °C. The reduction of rhenium is near complete below 400 °C, as also confirmed by H2-TPR measurements. A synergistic co-metal effect is observed for the cobalt rhenium system, as complete reduction of both cobalt and rhenium independently requires higher temperatures. The phases present in the cobalt rhenium catalyst during ammonia production following both pre-treatments are largely bimetallic Co-Re phases, and also monometallic Co and Re phases. The presence of nitrogen during the reduction step strongly promotes mixing of the two metals, and the bimetallic Co-Re phase is believed to be a pre-requisite for activity.

Prevalence of thalassemia in patients with microcytosis referred for hemoglobinopathy investigation in Ontario: a prospective cohort study.

In Ontario, Canada, beta-thalassemia is easily detected through measurement of hemoglobin A2, but most laboratories do not do exhaustive DNA investigations for alpha-thalassemia. Therefore, the prevalence of thalassemia in microcytic samples for hemoglobinopathy investigation in Ontario is unknown. To address this, we performed a prospective cohort study in which samples referred for hemoglobinopathy investigation were also evaluated for alpha-thalassemia by DNA testing. Of 800 samples submitted, 664 were evaluable. Of the 664 patients represented, 163 (24.5%) were beta-thalassemia major carriers, 68 (10.2%) were hemoglobin Bart's hydrops fetalis carriers and, in total, 361 (54.4%) had some form of thalassemia. We conclude that microcytosis due to thalassemia is common in Ontario and that major forms of thalassemia, including forms predisposing to hemoglobin Bart's hydrops fetalis and beta-thalassemia major, are frequent. This illustrates the importance of adequate prenatal and laboratory investigation for these abnormalities in Ontario and other similar multiethnic jurisdictions worldwide.

Immobilisation of fully sulfonated polyaniline on nanostructured calcium silicate.

Up to 7.4% (w/w) of the sulfonated polyaniline, poly(2-methoxyaniline-5-sulfonic acid) (PMAS) can be absorbed onto nanostructured calcium silicates. Spectroscopic and leaching studies on the novel PMAS-silicate nanocomposites obtained indicate that attachment of the PMAS occurs via electrostatic binding of PMAS sulfonate groups to Ca2+ sites on the silicates. The surface area and pore volume of the nanocomposites are comparable to those of pure silicate and increase the surface area of the PMAS polymer by several orders of magnitude. The PMAS emeraldine salt in the nanocomposites retains its chemical reactivity, being readily oxidised and reduced to its pernigraniline and leucoemeraldine forms, respectively. The conductivity of the composite is comparable to that of the pure PMAS, several orders of magnitude higher than that of dried nanostructured calcium silicate.

Synthesis and methane cracking activity of a silicon nitride supported vanadium nitride nanoparticle composite.

The co-ammonolysis of V(NMe2)4 and Si(NHMe)4 with ammonia in THF and in the presence of ammonium triflate ([NH4][CF3SO3]) leads to the formation of monolithic gels. Pyrolysing these gels produces mesoporous composite materials containing nanocrystalline VN and amorphous silicon imidonitride. Elemental mapping indicated a thorough distribution of VN with no evidence of large cluster segregation. Whilst not active for ammonia synthesis, the silicon nitride based materials were found to possess activity for the COx-free production of H2 from methane, which makes them candidates for applications in which the presence of low levels of CO in H2 feedstreams is detrimental.

Effect of chronic kidney disease on red blood cell rheology.

BACKGROUND: Anemia of renal failure is primarily a problem of decreased RBC production due to erythropoietin deficiency. RBC survival is also reduced, perhaps due to decreased RBC deformability. This study measured blood viscosity over a range of shear rates in erythropoietin-treated patients on hemodialysis (HD), and compared the findings to matched patients with chronic renal insufficiency (CRI) and healthy controls. METHODS: Four groups (control, CRI, non-diabetic HD, and diabetic HD) of 9 matched subjects were recruited. Blood viscosity was measured using a cone-plate viscometer over a variety of shear rates (11 to 225 s(-1)). RESULTS: Control subjects had lower viscosity values throughout all shear rates when compared to the 3 renal disease groups (P value=0.039). A trend was observed to higher levels of renal function being associated with decreased blood viscosity in patients with CRI. CONCLUSIONS: Patients with kidney disease have increased blood viscosity at all shear rates. This may be related to changes in RBC shape and decreased deformability in patients with kidney disease, independent of HD- or DM-status. This may have implications for strategies to treat anemia in these patients.

Evaluation of a dual hemoglobin A(2)/A(1c) quantitation kit on the bio-rad variant II automated hemoglobin analyzer.

CONTEXT: Quantitation of hemoglobin (Hb) A(1c) and investigation of hemoglobinopathy on the Bio-Rad Variant analyzers require a switch between 2 separate kits that is time consuming and causes errors. OBJECTIVE: Evaluation of a new Variant II HbA(2)/HbA(1c) Dual kit capable of both Hb A(1c) quantitation and hemoglobinopathy investigation on a single kit. DESIGN: We evaluated Hb A(1c), Hb A(2), and Hb F quantitation for precision, linearity, and correlation with current methodology. We also evaluated detection of Hb variants and correlation of Hb Barts quantitation. SETTING: Hamilton Regional Laboratory Medicine Program, Provincial Hemoglobinopathy Laboratory, St Joseph's Healthcare Site, Hamilton, Ontario. PATIENTS: Patient blood samples submitted for Hb A(1c) quantitation or hemoglobinopathy investigation. MAIN OUTCOME MEASURES: Precision, linearity, linear regression, and reference interval validation. RESULTS: We provide tables and figures illustrating precision, linearity, linear regression, and quantitation of Hb variants. We validated reference intervals for Hb A(1c), Hb A(2), and Hb F. CONCLUSIONS: The dual kit provides precise Hb A(1c), Hb A(2), and Hb F quantitation. The results show good linearity and correlate well with the results of current methods. We detected all clinically important Hb variants and a wide variety of rare variants. The dual kit has several advantages: it eliminates the need for extensive kit switch over; improves utility for newborn screening because of its quantification of Hb Barts; permits quantification of Hb A(1c) using the beta-Thal method; and eliminates the need for separate Hb A(2) reference intervals for patients with Hb S because of its accurate quantitation of Hb A(2) in the presence of Hb S.

A large-scale field study examining effects of exposure to clothianidin seed-treated canola on honey bee colony health, development, and overwintering success.

In summer 2012, we initiated a large-scale field experiment in southern Ontario, Canada, to determine whether exposure to clothianidin seed-treated canola (oil seed rape) has any adverse impacts on honey bees. Colonies were placed in clothianidin seed-treated or control canola fields during bloom, and thereafter were moved to an apiary with no surrounding crops grown from seeds treated with neonicotinoids. Colony weight gain, honey production, pest incidence, bee mortality, number of adults, and amount of sealed brood were assessed in each colony throughout summer and autumn. Samples of honey, beeswax, pollen, and nectar were regularly collected, and samples were analyzed for clothianidin residues. Several of these endpoints were also measured in spring 2013. Overall, colonies were vigorous during and after the exposure period, and we found no effects of exposure to clothianidin seed-treated canola on any endpoint measures. Bees foraged heavily on the test fields during peak bloom and residue analysis indicated that honey bees were exposed to low levels (0.5-2 ppb) of clothianidin in pollen. Low levels of clothianidin were detected in a few pollen samples collected toward the end of the bloom from control hives, illustrating the difficulty of conducting a perfectly controlled field study with free-ranging honey bees in agricultural landscapes. Overwintering success did not differ significantly between treatment and control hives, and was similar to overwintering colony loss rates reported for the winter of 2012-2013 for beekeepers in Ontario and Canada. Our results suggest that exposure to canola grown from seed treated with clothianidin poses low risk to honey bees.

Experimental arrangements suitable for the acquisition of inelastic neutron scattering spectra of heterogeneous catalysts.

Inelastic neutron scattering (INS) is increasingly being used for the characterization of heterogeneous catalysts. As the technique is uniquely sensitive to hydrogen atoms, vibrational spectra can be obtained that emphasize a hydrogenous component or hydrogen-containing moieties adsorbed on to an inorganic support. However, due to sensitivity constraints, the technique typically requires large sample masses (∼10 g catalyst). A reaction system is hereby described that enables suitable quantities of heterogeneous catalysts to be appropriately activated and operated under steady-state conditions for extended periods of time prior to acquisition of the INS spectrum. In addition to ex situ studies, a cell is described which negates the need for a sample transfer stage between reaction testing and INS measurement. This cell can operate up to temperatures of 823 K and pressures up to 20 bar. The apparatus is also amenable to adsorption experiments at the gas-solid interface.

Nano-structured calcium silicate hydrate functionalised with iodine.

Nano-structured calcium silicate hydrate can physisorb or chemisorb iodine, making it interesting for medical or materials science applications, where a slow, controlled release of iodine is desired. It was found that iodine can be sorbed and released by applying the elemental halogen in solution, either as a gas or as a solid. At ambient temperatures the sorption and desorption process is quantitative and physical, meaning that the same amount of iodine is taken up and released. At temperatures above 32.5 degrees C (305.7K) iodine reacts with the calcium silicate hydrate forming a complex, which is stable above the sublimation temperature of iodine. The formation energy for the iodine calcium silicate hydrate complex was established to be 41.8+/-0.8kJmol(-1) by calorimetry and the nature of the complex was investigated using X-ray photoelectron spectroscopy.

High oxygen affinity hemoglobin variant in a Canadian family: Hb Bunbury [beta94(FG1)Asp-->Asn, GAC-->AAC].

We investigated a three-generation Canadian family in which individuals displayed varying degrees of erythrocytosis due to a high oxygen affinity beta chain hemoglobin (Hb) variant [Hb Bunbury, beta94(FG1)Asp-->Asn, GAC-->AAC]. This is the fourth reported case of Hb Bunbury.

Identification of a new delta chain hemoglobin variant in a beta-thalassemia carrier: Hb A2-mumc [delta13(a10)Ala-->Asp].

We describe a case of beta-thalassemia (thal) trait in which the patient also carries a novel delta chain variant due to a missense mutation at amino acid codon 13 (GCC-->GAC, Ala-->Asp). The level of Hb A2 was not elevated, raising the potential for misdiagnosis.