The effects of volume of blood, number of consecutive cultures, and incubation time on pathogen recovery were evaluated for 37,568 blood cultures tested with the automated BACTEC 9240 instrument ...(Becton Dickinson Diagnostic Instrument Systems) at a tertiary care center over the period of 12 June 1996 through 12 October 1997. When the results for this study were compared with previous data published for manual broth-based blood culture systems and patient samples obtained in the 1970s and 1980s, the following were found: (1) the percentage increase in pathogen recovery per milliliter of blood is less, (2) more consecutive blood culture sets over a 24-h period are required to detect bloodstream pathogens, and (3) a shorter duration of incubation is required to diagnose bloodstream infections. Guidelines developed in the 1970s and 1980s for processing and culturing blood may require revision.
Vertebral fractures are associated with back pain and disability; however, relatively little is known about the impact of radiographic vertebral fractures on quality of life in population samples. ...The aim of this study was to determine the impact of a recent radiographic vertebral fracture on health-related quality of life (HRQoL).
Men and women aged 50 years and over were recruited from population registers in 12 European centers. Subjects completed an interviewer-administered questionnaire and had lateral spine radiographs performed. Subjects in these centers were followed prospectively and had repeat spinal radiographs performed a mean of 3.8 years later. Prevalent deformities were defined using established morphometric criteria, and incident vertebral fractures by both morphometric criteria and qualitative assessment. For each incident fracture case, three controls matched for age, gender, and center were selected: one with a prevalent deformity (at baseline) and two without prevalent deformities. All subjects were interviewed or completed a postal questionnaire instrument which included Short Form 12 (SF-12), the EQ-5D (former EuroQol), and the quality of life questionnaire of the International Osteoporosis Foundation (QUALEFFO). The median time from the second spinal radiograph until the quality of life survey was 1.9 years. Comparison between cases and their matched controls was undertaken using the signed rank test.
73 subjects with incident vertebral fracture (cases), mean age 64.8 years (of whom 23 had a baseline deformity), and 196 controls, mean age 63.9 years (of whom 60 had a baseline deformity), were studied. There were strong correlations between the domain scores for each of the three instruments. There was no statistically significant difference in any of the domain scores between cases and those controls with a prevalent deformity. However, compared with the controls without a prevalent deformity the cases had significantly impaired quality of life as determined using the total QUALEFFO score (38.2 vs 33.7), the physical component score of the SF-12 (39.9 vs 43.7) and the health status score of the EQ-5D (62.3 vs 69.9). When the analysis was repeated after stratification of the cases by baseline deformity status (i.e., cases with and without a prevalent deformity at baseline), cases with a prevalent deformity had impaired quality of life compared with their matched controls, both with and without a prevalent deformity. In contrast there was no significant difference in quality of life among the cases without a prevalent deformity and either control group.
In this population-based study a recent vertebral fracture was associated with impairment in quality of life, though this was mainly among those who had sustained a previous vertebral deformity.
Vertebral fracture is one of the major adverse clinical consequences of osteoporosis; however, there are few data concerning the incidence of vertebral fracture in population samples of men and ...women. The aim of this study was to determine the incidence of vertebral fracture in European men and women. A total of 14,011 men and women aged 50 years and over were recruited from population‐based registers in 29 European centers and had an interviewer‐administered questionnaire and lateral spinal radiographs performed. The response rate for participation in the study was approximately 50%. Repeat spinal radiographs were performed a mean of 3.8 years following the baseline film. All films were evaluated morphometrically. The definition of a morphometric fracture was a vertebra in which there was evidence of a 20% (+4 mm) or more reduction in anterior, middle, or posterior vertebral height between films—plus the additional requirement that a vertebra satisfy criteria for a prevalent deformity (using the McCloskey‐Kanis method) in the follow‐up film. There were 3174 men, mean age 63.1 years, and 3614 women, mean age 62.2 years, with paired duplicate spinal radiographs (48% of those originally recruited to the baseline survey). The age standardized incidence of morphometric fracture was 10.7/1000 person years (pyr) in women and 5.7/1000 pyr in men. The age‐standardized incidence of vertebral fracture as assessed qualitatively by the radiologist was broadly similar—12.1/1000 pyr and 6.8/1000 pyr, respectively. The incidence increased markedly with age in both men and women. There was some evidence of geographic variation in fracture occurrence; rates were higher in Sweden than elsewhere in Europe. This is the first large population‐based study to ascertain the incidence of vertebral fracture in men and women over 50 years of age across Europe. The data confirm the frequent occurrence of the disorder in men as well as in women and the rise in incidence with age.
Vertebral fractures are associated with back pain and disability. There are, however, few prospective data looking at back pain and disability following identification of radiographic vertebral ...fracture. The aim of this analysis was to determine the impact of radiographically identified vertebral fracture on the subsequent occurrence of back pain and disability. Women aged 50 years and over were recruited from population registers in 18 European centers for participation in the European Prospective Osteoporosis Study. Participants completed an interviewer-administered questionnaire which included questions about back pain in the past year and various activities of daily living, and they had lateral spine radiographs performed. Participants in these centers were followed prospectively and had repeat spine radiographs performed a mean of 3.7 years later. In addition they completed a questionnaire with the same baseline questions concerning back pain and activities of daily living. The presence of prevalent and incident vertebral fracture was defined using established morphometric criteria. The data were analyzed using logistic regression with back pain or disability (present or absent) at follow-up as the outcome variable with adjustment made for the baseline value of the variable. The study included 2,260 women, mean age 62.2 years. The mean time between baseline and follow-up survey was 5.0 years. Two hundred and forty participants had prevalent fractures at the baseline survey, and 85 developed incident fractures during follow-up. After adjustment for age, center, and the baseline level of disability, compared with those without baseline prevalent fracture, those with a prevalent fracture (odds ratio OR = 1.4; 95% confidence interval CI 1.0 to 2.0) or an incident fracture (OR = 1.7; 95% CI, 0.9 to 3.2) were more likely to report disability at follow-up, though the confidence intervals embraced unity. Those with both a prevalent and incident fracture, however, were significantly more likely to report disability at follow-up (OR = 3.1; 95% CI, 1.4 to 7.0). After adjustment for age, center, and frequency of back pain at baseline, compared with those without baseline vertebral fracture, those with a prevalent fracture were no more likely to report back pain at follow-up (OR = 1.2; 95% CI, 0.8 to 1.7). There was a small increased risk among those with a preexisting fracture who had sustained an incident fracture during follow-up (OR = 1.6; 95% CI, 0.6 to 4.1) though the confidence intervals embraced unity. In conclusion, although there was no significant increase in the level of back pain an average of 5 years following identification of radiographic vertebral fracture, women who suffered a further fracture during follow-up experienced substantial levels of disability with impairment in key physical functions of independent living.
Electromagnetic calorimetry Brown, R.M.; Cockerill, D.J.A.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2012, Letnik:
666
Journal Article
Recenzirano
Electromagnetic calorimetry forms a key element of almost all current high energy particle physics detectors and has widespread application in related experimental fields such as nuclear physics and ...astro-particle physics. It will play a particularly important role in the latest generation of experiments at the CERN Large Hadron Collider (LHC), where it is expected that high energy electrons and photons will provide some of the clearest signatures for new discoveries. This article introduces the basic concepts underlying electromagnetic calorimetry and illustrates how these principles have been applied in recent and current detector designs, explaining the connection between technical choices and specific physics goals. Designs are described in sufficient detail to demonstrate the compromises that have to be made in achieving optimum performance within practical constraints. The main emphasis is on the LHC experiments, which provide outstanding examples of the state-of-the-art. Selected examples from other domains, such as nuclear physics and neutrino experiments are also considered and particular attention is given to calorimeter design studies for the proposed International Linear Collider (ILC) where the concept of Particle Flow Analysis is being used as a guiding influence in the overall detector optimization.
Simulating multi-channel vacuum phototriodes using COMSOL Zahid, Sema; Hobson, P.R; Cockerill, D.J.A.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2018, Letnik:
912
Journal Article
Recenzirano
Odprti dostop
Vacuum phototriodes have been used for a number of years in particle physics experiments. For example, they were used in the OPAL experiment at LEP and are currently used in the endcap calorimeter of ...the CMS experiment at CERN’s Large Hadron Collider. A simulation of a CMS vacuum phototriode (RIE type FEU-188) has been implemented using the COMSOL multi-physics software environment. In addition, a new vacuum phototriode configured with a segmented anode, to provide four independent channels within the same overall device envelope, is presented. The induced signal as a function of time, and the effects of cross-talk in adjacent quadrants have been studied.
•COMSOL simulations demonstrate particle trajectories in strong magnetic fields.•The induced currents using Shockley–Ramo theorem are calculated on the anode.•Simulation of a new prototype vacuum phototriode with a segmented anode is presented.•The signal and cross talk is investigated via controlled illumination within COMSOL.
The aim of this population-based prospective study was to determine the incidence of limb fracture by site and gender in different regions of Europe. Men and women aged 50-79 years were recruited ...from population registers in 31 European centers. Subjects were invited to attend for an interviewer-administered questionnaire and lateral spinal radiographs. Subjects were subsequently followed up using an annual postal questionnaire which included questions concerning the occurrence of new fractures. Self-reported fractures were confirmed where possible by radiograph, attending physician or subject interview. There were 6451 men and 6936 women followed for a median of 3.0 years. During this time there were 140 incident limb fractures in men and 391 in women. The age-adjusted incidence of any limb fracture was 7.3/1000 person-years pyrs in men and 19 per 1000 pyrs in women, equivalent to a 2.5 times excess in women. Among women, the incidence of hip, humerus and distal forearm fracture, though not 'other' limb fracture, increased with age, while in men only the incidence of hip and humerus fracture increased with age. Among women, there was evidence of significant variation in the occurrence of hip, distal forearm and humerus fractures across Europe, with incidence rates higher in Scandinavia than in other European regions, though for distal forearm fracture the incidence in east Europe was similar to that observed in Scandinavia. Among men, there was no evidence of significant geographic variation in the occurrence of these fractures. This is the first large population-based study to characterize the incidence of limb fracture in men and women over 50 years of age across Europe. There are substantial differences in the descriptive epidemiology of limb fracture by region and gender.
In population-based studies of osteoporosis, ascertainment of fractures is typically based on self-report, with subsequent verification by medical records. The aim of this analysis was to assess the ...validity of self-report of incident nonspine fractures using a postal questionnaire. The degree of overreporting of fracture (false positives) was assessed by comparing self-reports of new fracture from respondents in the multicenter European Prospective Osteoporosis Study with data from other sources including radiographs and medical records. In the analysis, 563 subjects reported nonspine fractures. Verification of the presence of fracture was possible in 510 subjects. Of these, fractures were not confirmed in 11% (false positives). The percentage of false positives was greater in men than in women (15% vs 9%, p=0.04), and less for fractures of the distal forearm and hip than for fractures at other sites. In a separate study, the degree of underreporting (false negatives) was assessed by follow-up of 251 individuals with confirmed fracture ascertained from the records of fracture clinics in three European centers (Lubeck, Oviedo, Warsaw). Questionnaire responses were received from 174 (69%) subjects. Of these, 12 (7%) did not recall sustaining a fracture (false negatives). The percentage of false negatives was lower for hip and distal forearm fractures with only 3 of 90 (3%) such fractures not recalled. Using the combined data from both studies, of those who reported a 'date' of fracture on the questionnaire, 91% of subjects were correct to within 1 month of the actual date of the fracture. A postal questionnaire is a relatively simple and accurate method for obtaining information about the occurrence of hip and distal forearm fractures, including their timing. Accuracy of ascertainment of fractures at other sites is less good and where possible self-reported fractures at such sites should be verified from other sources.PUBLICATION ABSTRACT
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