997 resultados para Quantitative contrast
Resumo:
Introduction: Contrast induced nephropathy is the third most prevalent preventable cause of acute kidney injury in hospitalized patients. It defined as an absolute increase in serum creatinine ≥ 0.5 mg/dL and relative ≥ 25% increase. Objective: We studied the risk factors to intravenous injection contrast nephropathy after computed tomography. Methods: We studied 400 patients prospectively. Results: The incidence of contrast induced nephropathy, with an absolute or a relative increase were 4.0% and 13.9%, respectively. Diabetes and cardiac failure were independent risk factors for CIN a relative increase de serum creatinine (O.R.: 3.5 [95% CI: 1.92-6.36], p < 0.01, 2.61 [95% CI: 1.14-6.03%], p < 0.05, respectively). Conclusions: We showed association between uses of intravenous injection contrast after computed tomography with acute injury renal, notably with diabetes and heart failure.
Resumo:
Pouteria pachycarpa is a tree species, found in the Brazilian Amazon and Bolivia whose wood has been exploited from the native forest. The present research describes the quantitative characteristics of fruits and seeds and quantifies the seed germination of this species. The fruit and seed color were characterized and measurements taken of the mass, length, diameter and number of seeds per fruit, the seed length, width and thickness, the germination percentage, abnormal seedlings and dead seeds. Sowing was carried out on a substrate containing sand and sawdust (1:1), in four replications of 50 seeds. The predominant fruit and seed colors were vivid yellowish orange (9YR) and dark grayish brown (6YR), respectively. Fruit mass, length and diameter ranged from 37.7 to 192.4g, 41.3 to 87.3mm and 39.7 to 71.7mm, respectively. Fruits had from two to seven seeds, and 42.6% were damaged by insects. Seed length, width and thickness ranged from 22.4 to 35.2mm, 9.7 to 15.5mm and 5.5 to 10.8mm, respectively. Seedling emergence began 18 days after sowing. Maximum germination, 86%, was recorded 33 days after sowing. The germination curve was sigmoid, similar to the majority of species. The percentage of abnormal seedlings and dead seeds were 3% and 11%, respectively. Both fruits and seeds show great variation in quantitative characteristics and the germination is slow and non-uniform.
Resumo:
Atherosclerosis is a chronic and progressive disease of the vasculature. Increasing coronary atherosclerosis can lead to obstructive coronary artery disease (CAD) or myocardial infarction. Computed tomography angiography (CTA) allows noninvasive assessment of coronary anatomy and quantitation of atherosclerotic burden. Myocardial blood flow (MBF) can be accurately measured in absolute terms (mL/g/min) by positron emission tomography (PET) with [15O] H O as a radiotracer. We studied the coronary microvascular dysfunction as a risk factor for future coronary calcification in healthy young men by measuring the coronary flow reserve (CFR) which is the ratio between resting and hyperemic MBF. Impaired vasodilator function was not linked with accelerated atherosclerosis 11 years later. Currently, there is a global interest in quantitative PET perfusion imaging. We established optimal thresholds of [15O] H O PET perfusion for diagnosis of CAD (hyperemic MBF of 2.3 mL/g/min and CFR of 2.5) in the first multicenter study of this type (Turku, Amsterdam and Uppsala). In myocardial bridging a segment of the coronary artery travels inside the myocardium and can be seen as intramural course (CTA) or systolic compression (invasive coronary angiography). Myocardial bridging is frequently linked with proximal atherosclerotic plaques. We used quantitative [15O] H O PET perfusion to evaluate the hemodynamic effects of myocardial bridging. Myocardial bridging was not associated with decreased absolute MBF or increased atherosclerotic burden. Speckle tracking allows quantitative echocardiographic imaging of myocardial deformation. Speckle tracking during dobutamine stress echocardiography was feasible and comparable to subjective wall motion analysis in the diagnosis of CAD. In addition, it correctly risk stratified patients with multivessel disease and extensive ischemia.
Resumo:
The addition of the Charter of Rights and Freedoms represented a fundamental shift in Canadian governance. Many saw the tabling of such a document as a further, even fmal, step towards the Americanization of the Canadian polity. While the Charter's presence has significantly altered the relationship between citizens, government and the courts, it has done so by maintaining the traditional values and experiences that has been the hallmarks of Canadian constitutionalism. This is in contrast to the fears harboured by critics suggesting that the Charter was a further Americanization of the Canadian Polity, notwithstanding the very different natures of the American Bill of Rights and the Canadian Charter. Analyzing American Supreme Court precedent use by the Canadian Supreme Court has demonstrated that such an Americanization has not, in fact, occurred. In the present analysis of American precedent use in section 1 limitation of rights cases, the citation of these precedents are at best episodic, at least on the quantitative level. Qualitatively, the Canadian Supreme Court generally uses American jurisprudence to further support broad definitions of 'great rights' . As for the more intricate details of rights limitations and the process involved in detennining how Charter rights are limited, one would be hard pressed to find even cursory references to American case law.
Resumo:
ABSTRACT Background: Previous studies have implied that weight-bearing, intense and prolonged physical activities optimize bone accretion during the grow^ing years. The majority of past inquiries have used dual-energy X-ray absorptiometry (DXA) to examine bone strength and hand-wrist radiography to determine skeletal maturity in children. Recently, quantitative ultrasound (QUS) technologies have been developed to examine bone properties and skeletal maturity in a safe, noninvasive and cost-effective manner. Objective: The purpose of this study was to compare bone properties and skeletal maturity in competitive male child and adolescent athletes with minimallyactive, age-matched controls, using QUS technology. >. Methods: In total, 224 males were included in the study. The 115 pre-pubertal boys aged 10-12 years consisted of control, minimally-active children (n=34), soccer players (n=26), gymnasts (n=25) and hockey players (n=30). In addition, the 109 late-pubertal boys aged 14-16 years consisted of control, minimally-active adolescents (n=31), soccer players (n=30), gymnasts (n=17) and hockey players (n=31). The athletic groups were elite level players that predominantly trained year-round. Physical activity, nutrition and sports participation were assessed with various questionnaires. Anthropometries, such as height, weight and relative body fat percentage (BF%) were assessed using standard measures. Skeletal strength and age were evaluated using bone QUS. Lastly, salivary testosterone (sT) concentration was measured using Radioimmunoassay (RIA). Results: Within each age group, there were no significant differences between the activity groups in age and pubertal stage. An age effect was apparent in all variables, as expected. A sport effect was noted in all physical characteristics: the child and adolescent gymnasts were shorter and lighter than other sports groups. Adiposity was greater in the controls and in the hockey players. All child subjects were pubertal stage (fanner) I or II, while adolescent subjects were pubertal stage IV or V. There were no differences in daily energy and mineral intakes between sports groups. In both age groups, gymnasts had a higher training volume than other athletic groups. Bone speed of sound (50s) was higher in adolescents compared with the children. Gymnasts had signifieantly higher radial 50S than controls, hockey and soccer players in both age cohorts. Hockey athletes also had higher radial 50S than controls and soccer players in the child and adolescent groups, respectiyely. Child gymnasts and soccer players had greater tibial 50S compared with the hockey players and control groups. Likewise, adolescent gymnasts and soccer players had higher tibial SoS compared with the control group. No interaction was apparent between age and type of activity in any of the bone measures. » Lastly, maturity as assessed by sT and secondary sex characteristics (Tanner stage) was not different between sports group within each age group. Despite the similarity in chronological age, androgen levels and sexual maturity, differences between activity groups were noted in skeletal maturity. In the younger group, hockey players had the highest bone age while the soccer players had the lowest bone age. In the adolescent group, gymnasts and hockey players were characterized by higher skeletal maturity compared with controls. An interaction between the age and sport type effects was apparent in skeletal maturity, reflecting the fact that among the children, the soccer players were significantly less mature than the rest of the groups, while in the adolescents, the controls were the least skeletally mature. Summary and Conclusions: In summary, radial and tibial SOS are enhanced by the unique loading pattern in each sport (i.e, upper and lower extremities in gymnastics, lower extremities in soccer), with no cumulative effect between childhood and adolescence. That is, the effect of sport participation on bone SOS was apparent already among the young athletes. Enhanced bone properties among athletes of specific sports suggest that participation in these sports can improve bone strength and potential bone health.
Resumo:
An efficient way of synthesizing the deuterium labelled analogues of three methoxypyrazine compounds: 2-d3-methoxy-3-isopropylpyrazine, 2-d3-methoxy-3- isobutylpyrazine, and 2-d3-methoxy-3-secbutylpyrazine, has been developed. To confirm that the deuterium labels had been incorporated into the expected positions in the molecules synthesized, the relevant characterization by NMR, HRMS and GC/MS analysis was conducted. Another part of this work involved quantitative determination of methoxypyrazines in water and wines. Solid-phase extraction (SPE) proved to be a suitable means for the sample separation and concentration prior to GC/MS analysis.Such factors as the presence of ethanol, salt, and acid have been investigated which can influence the recovery by SPE for the pyrazines from the water matrix. Significantly, in this work comparatively simple fractional distillation was attempted to replace the conventional steam distillation for pre-concentrating a sample with a relatively large volume prior to SPE. Finally, a real wine sample spiked with the relevant isotope-labelled methoxypyrazines was quantitatively analyzed, revealing that the wine with 10 beetles per litre contained 138 ppt of 2-methoxy-3-isopropylpyrazine. Interestingly, we have also found that 2-methoxy-3-secbutylpyrazine exhibits an extremely low detection limit in GC/MS analysis compared with the detection limit of the other two methoxypyrazines: 2- methoxy-3-isopropylpyrazine and 2-methoxy-3-isobutylpyrazine.
Resumo:
A method is presented for determining the composition of thin films containing the elements Bi, Sr, Br, Cu, and Ca. Quantitative x-ray fluorescence (XRF) consisting of radioactive sources (secondary foil excitor 241Am-Mo source and 55Pe source), a Si(Li) detector, and a multichannel analyzer were employed. The XRF system was calibrated by using sol gel thin films of known element composition and also by sputtered thin films analyzed by the conventional Rutherford Back Scattering (RBS). The XRF system has been used to assist and optimize the sputter target composition required to produce high-Tc BiSrCaCuO films with the desired metal composition.
Resumo:
Ox amyl , an insecticide/nematicide with the chemical name; methyl ~'. ~·-dimethyl-~-(methylcarbamoyl)oxy-l-thiooxamimidate, and its major degradation compound; oxime or oximino compound, methyl ~',~'-dimethyl-~-hydroxy-l-thiooxamimidate were studied in this work. NMR and mass spectrometry were utilized in the structural studies. An attempt was made to explain the fragmentation patterns of some major peaks in the mass spectra of oxamyl and oxime. A new gas chromatographic method for the detection and determination of submicrogram levels of intact oxamyl using a electron-capture detector was developed. The principle of this method is to produce a derivative which is highly sensitive to an electron-capture detector. The derivative described is dinitrophenyl methylamine( DNPMA ) • Experimental conditions such as pH , reaction temperature , reaction time, the amount of reagent ( Dinitrofluaro benzene) etc. were thoroughly investigated and optimized. This method was successfully applied to the determination of oxamyl residues in tobacco leaves and soil. Throughout this J9D:oject , thin layer chromatography was also used in the separation:and clean up of oxamyl and oxime samples.
Resumo:
At head of title: For the International Geological Congress.
Resumo:
Chinese have unique perspectives on health and illness, which is mostly umecognized by western medicine. Immigration may contribute to problems with health consultations, inconvenience, and dissatisfaction. As the largest visible minority in Canada, Chinese- Canadians' perspectives on health should be studied in order to help Chinese immigrants adapt to a new health-care and health-promotion system, and keep them healthy. A quantitative questionnaire was designed based on the findings from a pilot study and previous literature. A hundred participants were recruited from Toronto, Vancouver, Halifax, and St. Catharines. Descriptive analysis and correlation analysis were used to investigate the structure of the variables. Findings indicated that most oftheir attitudes and corresponding practices to the different health aspects were positive. The relation between dietary practices and attitude was only found in small cities. Their attitudes were impacted by their length of stay in Canada. Their attitudes to regularly timed meals and psychological consultation were related to their acculturation level, as was the regularity of their practice of dental flossing. Their self-evaluated general health levels were also found to be affected by their medical history, education level, feeling to talk about • sexual health, and smoking, particularly in the male subjects of the study. In conclusion, they realized that each health aspect w~s important to their health. However, their practices did not bear a strong relation to their beliefs. Traditional thoughts about health reseeded with time. Acculturation level did not affect most of their attitudes or practices. Under pressure, the priority of the daily health practices decreased. Older persons, those with low incomes, lower education levels or families under stress need to pay more attention to their health level. In-depth future research was recommended.
Resumo:
Over the last two decades, the prevalence of obesity in the general population has been steadily increasing. Obesity is a major issue in scientific research because it is associated with many health problems, one of which is bone quality. In adult females, adiposity is associated with increased bone mineral density, suggesting that there is a protective effect of fat on bone. However, the association between adiposity and bone strength during childhood is not clear. Thus, the purpose of this study was to compare bone strength, as reflected by speed of sound (SOS), of overweight and obese girls and adolescents with normal-weight age-matched controls. Data from 75 females included normal-weight girls (G-NW; body fat:::; 25%; n = 21), overweight and obese girls (GOW; body fat ~ 28%; n = 19), normal-weight adolescents (A-NW, body fat:::; 25%; n = 13) and overweight and obese adolescents (A-OW; body fat ~ 28%; n = 22). Nutrition was assessed with a 24-hour recall questionnaire and habitual physical activity was measured for one week using accelerometry. Using quantitative ultrasound (QUS; Sunlight Omnisense™), bone SOS was measured at the distal radius and mid-tibia. No differences were found between groups in daily total energy, calcium or vitamin D intake. However, all groups were below the recommended daily calcium intake of 1300 mg (Osteoporosis Canada, 2008). Adolescents were significantly less active than girls (14.7 ± 0.6 vs. 6.3 ± 0.6% active for G and A, respectively). OW accumulated significantly less minutes of moderate-to-very vigorous physical activity per day (MVPA) than NW in both age groups (114 ± 6 vs. 57 ± 5 min/day for NW and OW, i respectively). Girls had significantly lower radial SOS (3794 ± 87 vs. 3964 ± 64 mls for G-NW and A-NW, respectively), and tibial SOS (3678 ± 86 vs. 3878 ± 52 mls for G-NW and A-NW, respectively) than adolescents. Radial SOS was similar in the two adiposity groups within each age group. However, tibial SOS was lower in the two overweight groups (3601 ± 75 mls vs. 3739 ± 134 mls for G-OW and A-OW, respectively) compared with the age-matched normal-weight controls. Body fat percentage negatively correlated with tibial SOS in the study sample as a whole (r = -0.30). However, when split into groups, percent bo~y fat correlated with tibial SOS only in the A-OW group (r = -0.53). MVPA correlated with tibial SOS (r = 0.40), once age was partialed out. In conclusion, in contrast withthe higher bone strength characteristic of obese adult women, overweight and obese girls and adolescents are characterized by low tibial bone strength, as assessed with QUS. The differences between adiposity groups in tibial SOS may be at least partially due to the reduced weight-bearing physical activity levels in the overweight girls and adolescents. However, other factors, such as hormonal influences associated with high body fat may also playa role in reducing bone strength in overweight girls. Further research is required to reveal the mechanisms causing low bone strength in overweight and obese children and adolescents.
Resumo:
This quantitative descriptive co-relational study used telephone survey interviews and stratified random sampling to collect data related to Social Capital (SC) and its components (trust and safety, reciprocity, civic engagement and collective action) and selected determinants of health variables in Niagara Region, Canada. Among the four components of social capital, trust and safety levels were highest among all participants (m=5.42, SD=1.0), with community engagement yielding the lowest mean score for the sample (m=1.93, SD=.8). Reciprocity had the strongest association with all other components of SC (r=0.51). Those most likely to report low levels of SC and health were unattached and low-income females. Males were more likely to report higher trust and safety levels and higher levels of self-rated health. In this study, a linear relationship between self-reported health status and SC was not found. Marital and employment status were associated with differences in mean scores of SC and self-reported health.
Resumo:
Parent education programs offered by a variety of public health services are effective support and knowledge resources that enhance positive parenting competencies in early childhood and adolescence. However, parenting education programs are less effective and encompass fewer benefits for fathers in comparison to mothers. This study sought to investigate trends of paternal involvement in early childhood and to compare the influence of parenting education programs on paternal involvement and conceptualization of fathers. A sample of 52 fathers, between the ages of 19 to 54, with children 6 years old and younger completed an electronic or hard copy version of a survey questionnaire reporting on their fathering and experiences as a dad. Findings indicate the sample of Canadian fathers self-reported high levels of paternal involvement, including many who favoured play-based interactions with their children. Although no significant difference in levels of involvement was noted between fathers who had versus those who had not previously participated in a parenting education program, half of the Canadian fathers indicated that supports are needed to strengthen their role as fathers. Results suggest that future initiatives to strengthen parent education program services available in Canada should specifically consider the father’s role.
Resumo:
Cognitive interviews were used to evaluate two draft versions of a financial survey in Jamaica. The qualitative version used a few open-ended questions, and the quantitative version used numerous close-ended questions. A secondary analysis based on the cognitive interview literature was used to guide a content analysis of the aggregate data of both surveys. The cognitive interview analysis found that the long survey had fewer respondent errors than the open-ended questions on the short survey. A grounded theory analysis then examined the aggregate cognitive data, showing that the respondents attached complex meanings to their financial information. The main limitation of this study was that the standard assessments of quantitative and qualitative reliability and validity were not utilized. Further research should utilize statistical methods to compare and contrast aggregated cognitive interview probe responses on open and close ended surveys.
Resumo:
The preparation and characterization of coordination complexes of Schiff-base and crown ether macrocycles is presented, for application as contrast agents for magnetic resonance imaging, Project 1; and single-molecule magnets (SMMs), Projects 2 and 3. In Project 1, a family of eight Mn(II) and Gd(III) complexes of N3X2 (X = NH, O) and N3O3 Schiff-base macrocycles were synthesized, characterized, and evaluated as potential contrast agents for MRI. In vitro and in vivo (rodent) studies indicate that the studied complexes display efficient contrast behaviour, negligible toxicity, and rapid excretion. In Project 2, DyIII complexes of Schiff-base macrocycles were prepared with a view to developing a new family of mononuclear Ln-SMMs with pseudo-D5h geometries. Each complex displayed slow relaxation of magnetization, with magnetically-derived energy barriers in the range Ueff = 4 – 24 K. In Project 3, coordination complexes of selected later lanthanides with various crown ether ligands were synthesized. Two families of complexes were structurally and magnetically analyzed: ‘axial’ or sandwich-type complexes based on 12-crown-4 and 15-crown-5; and ‘equatorial’ complexes based on 18-crown-6. Magnetic data are supported by ab initio calculations and luminescence measurements. Significantly, the first mononuclear Ln-SMM prepared from a crown ether ligand is described.