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  • Restricted
    Authors: 
    B. Daan Westenbrink; Lennaert Kleijn; Rudolf A. de Boer; Jan G.P. Tijssen; W. Warnica; Richard Baillot; Jean L. Rouleau; Wiek H. van Gilst; Imagine Investigators;
    Publisher: BMJ
    Country: Netherlands

    Objective To investigate the association between sustained postoperative anaemia and outcome after coronary artery bypass graft (CABG) surgery. Design Retrospective analysis of the IMAGINE trial, which tested the effect of the ACE inhibitor quinapril on cardiovascular events after CABG. Setting Thoracic surgery clinic/outpatient department. Patients 2553 stable patients with left ventricular ejection fraction >40% 2–7 days after scheduled CABG. Interventions Randomisation to quinapril or placebo. Main outcome measures Cox regression analysis for the association between postoperative anaemia and cardiovascular events and the effect of quinapril on the incidence of anaemia. Results Postoperative anaemia was sustained for >50 days in 44% of patients. Sustained postoperative anaemia was associated with an increased incidence of cardiovascular events during the first 3 months (adjusted HR (adjHR) 1.77, 95% CI 1.10 to 2.85, p=0.012) and during the maximum follow-up of 43 months (adjHR 1.37, 95% CI 1.14 to 1.65, p=0.008). When haemoglobin (Hb) was considered as a continuous variable, every 1 mg/dl decrease in Hb was associated with a 13% increase in cardiovascular events (adjHR 0.87, 95% CI 0.81 to 0.95, p=0.003) and a 22% increase in all-cause mortality (adjHR 0.78, 95% CI 0.60 to 0.99, p=0.034). Quinapril was associated with a slower postoperative recovery of Hb levels and a higher incidence of cardiovascular events in patients with anaemia (adjHR 1.60, 95% CI 1.1 to 2.4, p=0.024). Conclusions Postoperative anaemia is common, frequently persists for months after CABG surgery and is associated with an impaired outcome. In patients with anaemia, ACE inhibitors slowed recovery from postoperative anaemia and increased the incidence of cardiovascular events after CABG.

  • Restricted English
    Authors: 
    James J. Rothwell; John B. Lindsay; Martin Evans; Timothy E H Allott;
    Publisher: Elsevier
    Country: United Kingdom

    Upland peat soils in close proximity to urban and industrial areas can be contaminated with high concentrations of atmospherically deposited lead. The peat soils of the Peak District (UK) are characterised by extensive eroding gullies. Fine-resolution digital topographic data were used to map the extent and depth of these gullies. Peat samples from eroding gully walls and suspended sediments were collected and analysed for lead content. Variability in lead concentrations of gully wall material and suspended sediments can be explained by differences in mean upslope gully depth. The lead content of suspended sediment exported from catchments characterised by shallow peat gullies is higher than that exported from catchments with deep peat gullies. The empirical relationship between sediment-associated lead concentration and mean upslope gully depth was combined with the gully depth mapping to produce a predictive spatial model of suspended sediment lead concentrations across the Peak District. This model may be particularly useful for catchment managers who are currently involved in the restoration of eroding peat soils in the Peak District uplands.

  • Publication . Conference object . 2004
    Restricted English
    Authors: 
    Mark S. Ackerman; Marlene Huysman; John M. Carroll; Barry Wellman; Giorgio DeMichelis; Volker Wulf;
    Country: Netherlands

    Communities are social entities whose actors share common needs, interests, or practices: they constitute the basic units of social experience. With regard to communities, social capital captures the structural, relational and cognitive aspects of the relationships among their members. Social capital is defined as a set of properties of a social entity (e.g. norms, level of trust, and intensive social networking) which enables joint activities and cooperation for mutual benefit. It can be understood as the glue which holds communities together. On this panel we will discuss whether and how information technology can strengthen communities by fostering social capital.

  • Restricted
    Authors: 
    Niladri Basu; Anton M. Scheuhammer; Christian Sonne; Robert J. Letcher; Erik W. Born; Rune Dietz;
    Publisher: Wiley

    Polar bears (Ursus maritimus) are exposed to high concentrations of mercury because they are apex predators in the Arctic ecosystem. Although mercury is a potent neurotoxic heavy metal, it is not known whether current exposures are of neurotoxicological concern to polar bears. We tested the hypotheses that polar bears accumulate levels of mercury in their brains that exceed the estimated lowest observable adverse effect level (20 microg/g dry wt) for mammalian wildlife and that such exposures are associated with subtle neurological damage, as determined by measuring neurochemical biomarkers previously shown to be disrupted by mercury in other high-trophic wildlife. Brain stem (medulla oblongata) tissues from 82 polar bears subsistence hunted in East Greenland were studied. Despite surprisingly low levels of mercury in the brain stem region (total mercury = 0.36 +/- 0.12 microg/g dry wt), a significant negative correlation was measured between N-methyl-D-aspartate (NMDA) receptor levels and both total mercury (r = -0.34, p < 0.01) and methylmercury (r = -0.89, p < 0.05). No relationships were observed among mercury, selenium, and several other neurochemical biomarkers (dopamine-2, gamma-aminobutyric acid type A, muscarinic cholinergic, and nicotinic cholinergic receptors; cholinesterase and monoamine oxidase enzymes). These data show that East Greenland polar bears do not accumulate high levels of mercury in their brain stems. However, decreased levels of NMDA receptors could be one of the most sensitive indicators of mercury's subclinical and early effects.

  • Restricted English
    Authors: 
    Kwun Lun Cho; Axel Rosenhahn; Richard Thelen; Michael Grunze; Matthew Lobban; Markus Karahka; H. Jürgen Kreuzer;
    Project: NSERC

    In this work we experimentally and theoretically analyze the detachment of microscopic polystyrene beads from different self-assembled monolayer (SAM) surfaces in a shear flow in order to develop a mechanistic model for the removal of cells from surfaces. The detachment of the beads from the surface is treated as a thermally activated process applying an Arrhenius Ansatz to determine the activation barrier and attempt frequency of the rate determing step in bead removal. The statistical analysis of the experimental shear detachment data obtained in phosphate-buffered saline buffer results in an activation energy around 20 kJ/mol, which is orders of magnitude lower than the adhesion energy measured by atomic force microscopy (AFM). The same order of magnitude for the adhesion energy measured by AFM is derived from ab initio calculations of the van der Waals interaction energy between the polystyrene beads and the SAM-covered gold surface. We conclude that the rate determing step for detachment of the beads is the initiation of rolling on the surface (overcoming static friction) and not physical detachment, i.e., lifting the particle off the surface.

  • Restricted
    Authors: 
    Alexander V. Louie; Suresh Senan; Max Dahele; Ben J. Slotman; Wilko F.A.R. Verbakel;
    Country: Netherlands

    Purpose Use of stereotactic ablative radiation therapy (SABR) for subcentimeter lung tumors is controversial. We report our outcomes for tumors with diameter ≤1 cm and their visibility on cone beam computed tomography (CBCT) scans and retrospectively evaluate the planned dose using a deterministic dose calculation algorithm (Acuros XB [AXB]). Methods and Materials We identified subcentimeter tumors from our institutional SABR database. Tumor size was remeasured on an artifact-free phase of the planning 4-dimensional (4D)-CT. Clinical plan doses were generated using either a pencil beam convolution or an anisotropic analytic algorithm (AAA). All AAA plans were recalculated using AXB, and differences among D95 and mean dose for internal target volume (ITV) and planning target volume (PTV) on the average intensity CT dataset, as well as for gross tumor volume (GTV) on the end respiratory phases were reported. For all AAA patients, CBCT scans acquired during each treatment fraction were evaluated for target visibility. Progression-free and overall survival rates were calculated using the Kaplan-Meier method. Results Thirty-five patients with 37 subcentimeter tumors were eligible for analysis. For the 22 AAA plans recalculated using AXB, Mean D95 ± SD values were 2.2 ± 4.4% (ITV) and 2.5 ± 4.8% (PTV) lower using AXB; whereas mean doses were 2.9 ± 4.9% (ITV) and 3.7 ± 5.1% (PTV) lower. Calculated AXB doses were significantly lower in one patient (difference in mean ITV and PTV doses, as well as in mean ITV and PTV D95 ranged from 22%-24%). However, the end respiratory phase GTV received at least 95% of the prescription dose. Review of 92 CBCT scans from all AAA patients revealed that the tumor was visualized in 82 images, and its position could be inferred in other images. The 2-year local progression-free survival was 100%. Conclusions Patients with subcentimeter lung tumors are good candidates for SABR, given the dosimetry, ability to localize tumors with image guidance, and excellent local control.

  • Restricted
    Authors: 
    Kuo-Ting Chen; Jim Nieuwenhuizen; Maryana Handula; Yann Seimbille;
    Publisher: Royal Society of Chemistry (RSC)
    Country: Netherlands

    We herein describe the development of a novel dual-modality optical/radio-imaging agent for general and site-specific labeling of biovectors through a 2-cyanobenzothiazole (CBT)/1,2-aminothiol click reaction. The CBT-based multifunctional single-attachment-point (MSAP) agent enables a single-step synthesis of various dual-modality probes characterized by rapid conjugation, high labeling yields, metabolically stable products and applicability to orthogonal two-step labeling of sensitive biomolecules. In addition, the two-step radiolabeling protocol and click reaction were optimized by using CBT scavengers to improve the reaction rate and molar activity of the imaging probes. Our methodology allows for a simple and efficient synthetic route to produce a variety of dual-modality imaging agents for preoperative surgical planning and intraoperative surgical guidance.

  • Restricted English
    Authors: 
    A. Mederos; David F. Kelton; Andrew S. Peregrine; John A. VanLeeuwen; S. Fernández; A. LeBoeuf; Paula I. Menzies; Ralph C. Martin;
    Publisher: Elsevier Science
    Country: Argentina
    Project: NSERC

    A study was conducted in sheep on Canadian farms to describe the relationship between packed cell volume (PCV) or fecal egg counts (FEC) and subjective clinical parameters that may indicate the severity of parasitic gastroenteritis. Twenty-one farms in Ontario (ON) and 8 farms in Quebec (QC) were purposively selected and visited during April–May (spring) and August (summer) 2007. At each farm visit, blood and fecal samples were collected from 10 ewes and 10 female lambs; body condition score (BCS), dag score (DS), fecal consistency score (FCS) and FAMACHA score were recorded for all sampled sheep. Packed cell volume was determined for all blood samples, and FEC were performed for all fecal samples. Summary statistics and simple correlations were performed for the parameters recorded. Two mixed models with random effects at the farm level were developed; one using PCV as the response variable and another using the natural log of eggs per gram of feces (lnEPG). Finally, the residuals from both models were correlated to the covariates in the models. The mean PCV values during the spring were 29.7% and 36.7% for lambs, and 28.8% and 31.1% for ewes, in ON and QC, respectively. During the summer, the mean PCV was 32.0% and 32.8% for lambs, and 30.1% and 29.9% for ewes, in ON and QC, respectively. The arithmetic mean FEC per gram of feces (EPG) during the spring was 3 and 2 for lambs, and 1266 and 789 for ewes, in ON and QC, respectively, whereas during summer the arithmetic mean EPG was 907 and 237 for lambs, and 458 and 246 for ewes, in ON and QC, respectively. Results from simple correlations indicated that PCV was negatively correlated with lnEPG (r = −0.255; r2 = 6.5%) and FAMACHA (r = −0.312; r2 = 9.7%), and positively correlated with BCS (r = 0.317; r2 = 10%). LnEPG was negatively correlated with BCS (r = −0.232; r2 = 5.4%) and PCV (r = −0.255; r2 = 6.5%), but positively correlated with FAMACHA (r = 0.178; r2 = 3.2%) and DS (r = 0.086; r2 = 0.7%). Results from the models indicated that PCV and lnEPG residuals were negatively correlated with FAMACHA, FCS and almost all categories of BCS and DS, although the correlations were very low. The main results from this study suggested that none of the subjective clinical parameters evaluated were highly correlated with PCV or lnEPG and therefore were not good predictors of lnEPG or PCV on the studied farms in Ontario and Quebec. Fil: Mederos, A.. Instituto Nacional de Investigación Agropecuaria; Uruguay Fil: Kelton, D.. University of Guelph; Canadá Fil: Peregrine, A. S.. University of Guelph; Canadá Fil: VanLeeuwen, J.. University Of Prince Edward Island; Canadá Fil: Fernández, Alicia Silvina. University of Guelph; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: LeBoeuf, A.. Ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec; Canadá Fil: Menzies, P.. University of Guelph; Canadá Fil: Martin, R.. Nova Scotia Agricultural College; Canadá

  • Publication . Other literature type . Part of book or chapter of book . 2011
    Restricted
    Authors: 
    Paul A. Johnson; Libero J. Bartolotti; Paul W. Ayers; Tim Fievez; Paul Geerlings;
    Publisher: Springer Netherlands
    Country: Belgium

    Conceptual density-functional theory (DFT) provides a mathematical framework for using changes of the electron density to understand chemical reactions and chemical reactivity. The key idea is that by studying the response of a molecule or materials to perturbations, one can decipher its reactivity preferences. If a system reacts favorably to a perturbation, then this indicates that the system will react favorably with a certain class of reagents. Differentials of the energy may thus be interpreted as reactivity indicators. Because of the key role of energy differentials, the mathematical framework of conceptual DFT is similar to classical thermodynamics, with state functions, variational principles, and Legendre transforms. In this chapter we use this thermodynamic simile to present the mathematical underpinnings of conceptual DFT. Applications to systems of interest to organic, inorganic, and biological chemists are used to demonstrate how these abstract concepts may be applied to concrete chemical problems.

  • Restricted
    Authors: 
    F. Stelma; M.H. van der Ree; Leo Jansen; Marion G. Peters; Harry L.A. Janssen; Hans L. Zaaijer; R. Bart Takkenberg; Henk W. Reesink;
    Country: Netherlands

    Combining peginterferon-alfa-2a (pegIFN) with a nucleotide analogue can result in higher rates of HBsAg loss than either therapy given alone. Here, we investigated the durability of the response to combination therapy in chronic hepatitis B (CHB) patients after 5 years of follow-up. In the initial study, 92 CHB patients (44 HBeAg-positive, 48 HBeAg-negative) with HBV DNA >100 000 c/mL (~20 000 IU/mL) and active hepatitis were treated for 48 weeks with pegIFN 180 μg/week and 10 mg adefovir dipivoxil daily. For the long-term follow-up (LTFU) study, patients were followed up for 5 years after the end of treatment. At year 5, 70 (32 HBeAg-positive, 38 HBeAg-negative) patients remained in the study. At year 5, 19% (6/32) of HBeAg-positive patients and 16% (6/38) of HBeAg-negative patients lost HBsAg, and no HBsAg seroreversion was observed. The 5-year cumulative Kaplan-Meier estimate for HBsAg loss was 17.2% for HBeAg-positive patients and 19.3% for HBeAg-negative patients. Fourteen of sixteen patients who lost HBsAg at any time point during follow-up developed anti-HBs antibodies (>10 IU/L). At year 5, in total 63% (20/32) of HBeAg-positive and 71% (27/38) of HBeAg-negative patients were retreated with nucleos(t)ide analogues during follow-up. The cumulative Kaplan-Meier estimate for retreatment was 60% of patients at year 5. At year 5 of follow-up, 18% of CHB patients treated with pegIFN/nucleotide analogue combination therapy had durable HBsAg loss and 88% of these had developed anti-HBs antibodies.

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Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
14,659 Research products, page 1 of 1,466
  • Restricted
    Authors: 
    B. Daan Westenbrink; Lennaert Kleijn; Rudolf A. de Boer; Jan G.P. Tijssen; W. Warnica; Richard Baillot; Jean L. Rouleau; Wiek H. van Gilst; Imagine Investigators;
    Publisher: BMJ
    Country: Netherlands

    Objective To investigate the association between sustained postoperative anaemia and outcome after coronary artery bypass graft (CABG) surgery. Design Retrospective analysis of the IMAGINE trial, which tested the effect of the ACE inhibitor quinapril on cardiovascular events after CABG. Setting Thoracic surgery clinic/outpatient department. Patients 2553 stable patients with left ventricular ejection fraction >40% 2–7 days after scheduled CABG. Interventions Randomisation to quinapril or placebo. Main outcome measures Cox regression analysis for the association between postoperative anaemia and cardiovascular events and the effect of quinapril on the incidence of anaemia. Results Postoperative anaemia was sustained for >50 days in 44% of patients. Sustained postoperative anaemia was associated with an increased incidence of cardiovascular events during the first 3 months (adjusted HR (adjHR) 1.77, 95% CI 1.10 to 2.85, p=0.012) and during the maximum follow-up of 43 months (adjHR 1.37, 95% CI 1.14 to 1.65, p=0.008). When haemoglobin (Hb) was considered as a continuous variable, every 1 mg/dl decrease in Hb was associated with a 13% increase in cardiovascular events (adjHR 0.87, 95% CI 0.81 to 0.95, p=0.003) and a 22% increase in all-cause mortality (adjHR 0.78, 95% CI 0.60 to 0.99, p=0.034). Quinapril was associated with a slower postoperative recovery of Hb levels and a higher incidence of cardiovascular events in patients with anaemia (adjHR 1.60, 95% CI 1.1 to 2.4, p=0.024). Conclusions Postoperative anaemia is common, frequently persists for months after CABG surgery and is associated with an impaired outcome. In patients with anaemia, ACE inhibitors slowed recovery from postoperative anaemia and increased the incidence of cardiovascular events after CABG.

  • Restricted English
    Authors: 
    James J. Rothwell; John B. Lindsay; Martin Evans; Timothy E H Allott;
    Publisher: Elsevier
    Country: United Kingdom

    Upland peat soils in close proximity to urban and industrial areas can be contaminated with high concentrations of atmospherically deposited lead. The peat soils of the Peak District (UK) are characterised by extensive eroding gullies. Fine-resolution digital topographic data were used to map the extent and depth of these gullies. Peat samples from eroding gully walls and suspended sediments were collected and analysed for lead content. Variability in lead concentrations of gully wall material and suspended sediments can be explained by differences in mean upslope gully depth. The lead content of suspended sediment exported from catchments characterised by shallow peat gullies is higher than that exported from catchments with deep peat gullies. The empirical relationship between sediment-associated lead concentration and mean upslope gully depth was combined with the gully depth mapping to produce a predictive spatial model of suspended sediment lead concentrations across the Peak District. This model may be particularly useful for catchment managers who are currently involved in the restoration of eroding peat soils in the Peak District uplands.

  • Publication . Conference object . 2004
    Restricted English
    Authors: 
    Mark S. Ackerman; Marlene Huysman; John M. Carroll; Barry Wellman; Giorgio DeMichelis; Volker Wulf;
    Country: Netherlands

    Communities are social entities whose actors share common needs, interests, or practices: they constitute the basic units of social experience. With regard to communities, social capital captures the structural, relational and cognitive aspects of the relationships among their members. Social capital is defined as a set of properties of a social entity (e.g. norms, level of trust, and intensive social networking) which enables joint activities and cooperation for mutual benefit. It can be understood as the glue which holds communities together. On this panel we will discuss whether and how information technology can strengthen communities by fostering social capital.

  • Restricted
    Authors: 
    Niladri Basu; Anton M. Scheuhammer; Christian Sonne; Robert J. Letcher; Erik W. Born; Rune Dietz;
    Publisher: Wiley

    Polar bears (Ursus maritimus) are exposed to high concentrations of mercury because they are apex predators in the Arctic ecosystem. Although mercury is a potent neurotoxic heavy metal, it is not known whether current exposures are of neurotoxicological concern to polar bears. We tested the hypotheses that polar bears accumulate levels of mercury in their brains that exceed the estimated lowest observable adverse effect level (20 microg/g dry wt) for mammalian wildlife and that such exposures are associated with subtle neurological damage, as determined by measuring neurochemical biomarkers previously shown to be disrupted by mercury in other high-trophic wildlife. Brain stem (medulla oblongata) tissues from 82 polar bears subsistence hunted in East Greenland were studied. Despite surprisingly low levels of mercury in the brain stem region (total mercury = 0.36 +/- 0.12 microg/g dry wt), a significant negative correlation was measured between N-methyl-D-aspartate (NMDA) receptor levels and both total mercury (r = -0.34, p < 0.01) and methylmercury (r = -0.89, p < 0.05). No relationships were observed among mercury, selenium, and several other neurochemical biomarkers (dopamine-2, gamma-aminobutyric acid type A, muscarinic cholinergic, and nicotinic cholinergic receptors; cholinesterase and monoamine oxidase enzymes). These data show that East Greenland polar bears do not accumulate high levels of mercury in their brain stems. However, decreased levels of NMDA receptors could be one of the most sensitive indicators of mercury's subclinical and early effects.

  • Restricted English
    Authors: 
    Kwun Lun Cho; Axel Rosenhahn; Richard Thelen; Michael Grunze; Matthew Lobban; Markus Karahka; H. Jürgen Kreuzer;
    Project: NSERC

    In this work we experimentally and theoretically analyze the detachment of microscopic polystyrene beads from different self-assembled monolayer (SAM) surfaces in a shear flow in order to develop a mechanistic model for the removal of cells from surfaces. The detachment of the beads from the surface is treated as a thermally activated process applying an Arrhenius Ansatz to determine the activation barrier and attempt frequency of the rate determing step in bead removal. The statistical analysis of the experimental shear detachment data obtained in phosphate-buffered saline buffer results in an activation energy around 20 kJ/mol, which is orders of magnitude lower than the adhesion energy measured by atomic force microscopy (AFM). The same order of magnitude for the adhesion energy measured by AFM is derived from ab initio calculations of the van der Waals interaction energy between the polystyrene beads and the SAM-covered gold surface. We conclude that the rate determing step for detachment of the beads is the initiation of rolling on the surface (overcoming static friction) and not physical detachment, i.e., lifting the particle off the surface.

  • Restricted
    Authors: 
    Alexander V. Louie; Suresh Senan; Max Dahele; Ben J. Slotman; Wilko F.A.R. Verbakel;
    Country: Netherlands

    Purpose Use of stereotactic ablative radiation therapy (SABR) for subcentimeter lung tumors is controversial. We report our outcomes for tumors with diameter ≤1 cm and their visibility on cone beam computed tomography (CBCT) scans and retrospectively evaluate the planned dose using a deterministic dose calculation algorithm (Acuros XB [AXB]). Methods and Materials We identified subcentimeter tumors from our institutional SABR database. Tumor size was remeasured on an artifact-free phase of the planning 4-dimensional (4D)-CT. Clinical plan doses were generated using either a pencil beam convolution or an anisotropic analytic algorithm (AAA). All AAA plans were recalculated using AXB, and differences among D95 and mean dose for internal target volume (ITV) and planning target volume (PTV) on the average intensity CT dataset, as well as for gross tumor volume (GTV) on the end respiratory phases were reported. For all AAA patients, CBCT scans acquired during each treatment fraction were evaluated for target visibility. Progression-free and overall survival rates were calculated using the Kaplan-Meier method. Results Thirty-five patients with 37 subcentimeter tumors were eligible for analysis. For the 22 AAA plans recalculated using AXB, Mean D95 ± SD values were 2.2 ± 4.4% (ITV) and 2.5 ± 4.8% (PTV) lower using AXB; whereas mean doses were 2.9 ± 4.9% (ITV) and 3.7 ± 5.1% (PTV) lower. Calculated AXB doses were significantly lower in one patient (difference in mean ITV and PTV doses, as well as in mean ITV and PTV D95 ranged from 22%-24%). However, the end respiratory phase GTV received at least 95% of the prescription dose. Review of 92 CBCT scans from all AAA patients revealed that the tumor was visualized in 82 images, and its position could be inferred in other images. The 2-year local progression-free survival was 100%. Conclusions Patients with subcentimeter lung tumors are good candidates for SABR, given the dosimetry, ability to localize tumors with image guidance, and excellent local control.

  • Restricted
    Authors: 
    Kuo-Ting Chen; Jim Nieuwenhuizen; Maryana Handula; Yann Seimbille;
    Publisher: Royal Society of Chemistry (RSC)
    Country: Netherlands

    We herein describe the development of a novel dual-modality optical/radio-imaging agent for general and site-specific labeling of biovectors through a 2-cyanobenzothiazole (CBT)/1,2-aminothiol click reaction. The CBT-based multifunctional single-attachment-point (MSAP) agent enables a single-step synthesis of various dual-modality probes characterized by rapid conjugation, high labeling yields, metabolically stable products and applicability to orthogonal two-step labeling of sensitive biomolecules. In addition, the two-step radiolabeling protocol and click reaction were optimized by using CBT scavengers to improve the reaction rate and molar activity of the imaging probes. Our methodology allows for a simple and efficient synthetic route to produce a variety of dual-modality imaging agents for preoperative surgical planning and intraoperative surgical guidance.

  • Restricted English
    Authors: 
    A. Mederos; David F. Kelton; Andrew S. Peregrine; John A. VanLeeuwen; S. Fernández; A. LeBoeuf; Paula I. Menzies; Ralph C. Martin;
    Publisher: Elsevier Science
    Country: Argentina
    Project: NSERC

    A study was conducted in sheep on Canadian farms to describe the relationship between packed cell volume (PCV) or fecal egg counts (FEC) and subjective clinical parameters that may indicate the severity of parasitic gastroenteritis. Twenty-one farms in Ontario (ON) and 8 farms in Quebec (QC) were purposively selected and visited during April–May (spring) and August (summer) 2007. At each farm visit, blood and fecal samples were collected from 10 ewes and 10 female lambs; body condition score (BCS), dag score (DS), fecal consistency score (FCS) and FAMACHA score were recorded for all sampled sheep. Packed cell volume was determined for all blood samples, and FEC were performed for all fecal samples. Summary statistics and simple correlations were performed for the parameters recorded. Two mixed models with random effects at the farm level were developed; one using PCV as the response variable and another using the natural log of eggs per gram of feces (lnEPG). Finally, the residuals from both models were correlated to the covariates in the models. The mean PCV values during the spring were 29.7% and 36.7% for lambs, and 28.8% and 31.1% for ewes, in ON and QC, respectively. During the summer, the mean PCV was 32.0% and 32.8% for lambs, and 30.1% and 29.9% for ewes, in ON and QC, respectively. The arithmetic mean FEC per gram of feces (EPG) during the spring was 3 and 2 for lambs, and 1266 and 789 for ewes, in ON and QC, respectively, whereas during summer the arithmetic mean EPG was 907 and 237 for lambs, and 458 and 246 for ewes, in ON and QC, respectively. Results from simple correlations indicated that PCV was negatively correlated with lnEPG (r = −0.255; r2 = 6.5%) and FAMACHA (r = −0.312; r2 = 9.7%), and positively correlated with BCS (r = 0.317; r2 = 10%). LnEPG was negatively correlated with BCS (r = −0.232; r2 = 5.4%) and PCV (r = −0.255; r2 = 6.5%), but positively correlated with FAMACHA (r = 0.178; r2 = 3.2%) and DS (r = 0.086; r2 = 0.7%). Results from the models indicated that PCV and lnEPG residuals were negatively correlated with FAMACHA, FCS and almost all categories of BCS and DS, although the correlations were very low. The main results from this study suggested that none of the subjective clinical parameters evaluated were highly correlated with PCV or lnEPG and therefore were not good predictors of lnEPG or PCV on the studied farms in Ontario and Quebec. Fil: Mederos, A.. Instituto Nacional de Investigación Agropecuaria; Uruguay Fil: Kelton, D.. University of Guelph; Canadá Fil: Peregrine, A. S.. University of Guelph; Canadá Fil: VanLeeuwen, J.. University Of Prince Edward Island; Canadá Fil: Fernández, Alicia Silvina. University of Guelph; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: LeBoeuf, A.. Ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec; Canadá Fil: Menzies, P.. University of Guelph; Canadá Fil: Martin, R.. Nova Scotia Agricultural College; Canadá

  • Publication . Other literature type . Part of book or chapter of book . 2011
    Restricted
    Authors: 
    Paul A. Johnson; Libero J. Bartolotti; Paul W. Ayers; Tim Fievez; Paul Geerlings;
    Publisher: Springer Netherlands
    Country: Belgium

    Conceptual density-functional theory (DFT) provides a mathematical framework for using changes of the electron density to understand chemical reactions and chemical reactivity. The key idea is that by studying the response of a molecule or materials to perturbations, one can decipher its reactivity preferences. If a system reacts favorably to a perturbation, then this indicates that the system will react favorably with a certain class of reagents. Differentials of the energy may thus be interpreted as reactivity indicators. Because of the key role of energy differentials, the mathematical framework of conceptual DFT is similar to classical thermodynamics, with state functions, variational principles, and Legendre transforms. In this chapter we use this thermodynamic simile to present the mathematical underpinnings of conceptual DFT. Applications to systems of interest to organic, inorganic, and biological chemists are used to demonstrate how these abstract concepts may be applied to concrete chemical problems.

  • Restricted
    Authors: 
    F. Stelma; M.H. van der Ree; Leo Jansen; Marion G. Peters; Harry L.A. Janssen; Hans L. Zaaijer; R. Bart Takkenberg; Henk W. Reesink;
    Country: Netherlands

    Combining peginterferon-alfa-2a (pegIFN) with a nucleotide analogue can result in higher rates of HBsAg loss than either therapy given alone. Here, we investigated the durability of the response to combination therapy in chronic hepatitis B (CHB) patients after 5 years of follow-up. In the initial study, 92 CHB patients (44 HBeAg-positive, 48 HBeAg-negative) with HBV DNA >100 000 c/mL (~20 000 IU/mL) and active hepatitis were treated for 48 weeks with pegIFN 180 μg/week and 10 mg adefovir dipivoxil daily. For the long-term follow-up (LTFU) study, patients were followed up for 5 years after the end of treatment. At year 5, 70 (32 HBeAg-positive, 38 HBeAg-negative) patients remained in the study. At year 5, 19% (6/32) of HBeAg-positive patients and 16% (6/38) of HBeAg-negative patients lost HBsAg, and no HBsAg seroreversion was observed. The 5-year cumulative Kaplan-Meier estimate for HBsAg loss was 17.2% for HBeAg-positive patients and 19.3% for HBeAg-negative patients. Fourteen of sixteen patients who lost HBsAg at any time point during follow-up developed anti-HBs antibodies (>10 IU/L). At year 5, in total 63% (20/32) of HBeAg-positive and 71% (27/38) of HBeAg-negative patients were retreated with nucleos(t)ide analogues during follow-up. The cumulative Kaplan-Meier estimate for retreatment was 60% of patients at year 5. At year 5 of follow-up, 18% of CHB patients treated with pegIFN/nucleotide analogue combination therapy had durable HBsAg loss and 88% of these had developed anti-HBs antibodies.