Experimental verification of principal losses in a regulatory particulate matter emissions sampling system for aircraft turbine engines.

A sampling system for measuring emissions of nonvolatile particulate matter (nvPM) from aircraft gas turbine engines has been developed to replace the use of smoke number and is used for international regulatory purposes. This sampling system can be up to 35 m in length. The sampling system length in addition to the volatile particle remover (VPR) and other sampling system components lead to substantial particle losses, which are a function of the particle size distribution, ranging from 50 to 90% for particle number concentrations and 10-50% for particle mass concentrations. The particle size distribution is dependent on engine technology, operating point, and fuel composition. Any nvPM emissions measurement bias caused by the sampling system will lead to unrepresentative emissions measurements which limit the method as a universal metric. Hence, a method to estimate size dependent sampling system losses using the system parameters and the measured mass and number concentrations was also developed (SAE 2017; SAE 2019). An assessment of the particle losses in two principal components used in ARP6481 (SAE 2019) was conducted during the VAriable Response In Aircraft nvPM Testing (VARIAnT) 2 campaign. Measurements were made on the 25-meter sample line portion of the system using multiple, well characterized particle sizing instruments to obtain the penetration efficiencies. An agreement of ± 15% was obtained between the measured and the ARP6481 method penetrations for the 25-meter sample line portion of the system. Measurements of VPR penetration efficiency were also made to verify its performance for aviation nvPM number. The research also demonstrated the difficulty of making system loss measurements and substantiates the E-31 decision to predict rather than measure system losses.

Progression of coronary artery calcification in asymptomatic individuals with pre-existing calcium score.

AIM: Coronary artery calcification (CAC) has been introduced as a reliable, non-invasive marker of atherosclerosis. In this retrospective study, we investigated the progression of CAC using electron beam computed tomography. METHODS: The study enrolled 598 individuals (521 males; mean age: 59.3±8.3 years) with initial CAC score (CACS) ≥10. The mean interscan period was 2.4±1.35 years (range: 1-7 years). The mean CACS, for the entire cohort, was 262.4±423.9 at baseline scan and 380.3±547.6 at follow-up. The mean annualized progression in CACS was 57.7±123.7; 47.4±66.5 in females and 58.3±128.1 in males (P=0.46). The mean annualized progression in CACS was 39.6±61.3 in individuals <60 years and 75.7±161.5 in individuals >60 years (P=0.0003). In multivariate analysis, only baseline CACS (P<0.0001) and smoking (P=0.002) were independently associated with the annual change in CACS.

Coronary artery calcification progression in asymptomatic individuals with initial score of zero.

The aim of this study is to determine the progression of coronary artery calcification (CAC) using electron beam computed tomography (CT) when the initial CAC score (CACS) is zero and to determine the best interval to repeat a CAC scan. We studied 388 individuals with zero CACS (308 males; mean age: 48.8 ± 8.26 years) who underwent 2 consecutive CT scans in a period of at least 12 months apart. The interscan period was 2.99 ± 1.35 years (range: 1-6 years). Three-quarters of the individuals (75%) did not develop any CAC progression, 20.87% presented CAC progression of 1 to 10, 3.6% had 11 to 50, whereas only 0.51% had >50. The average time of new CAC development was 4.2 ± 1.1 years. Individuals with CAC progression presented higher incidence of hypertension, diabetes mellitus, hypercholesterolaemia and higer frequency of male gender than those with without CAC changes (p<0.02). No cardiac events occurred during the follow-up period.

Aggressive and diffuse coronary calcification in South Asian angina patients compared to Caucasians with similar risk factors.

BACKGROUND: Ethnic differences in prevalence and severity of coronary artery disease are well established and are usually attributed to risk factors variation. This study investigates the differences in coronary artery narrowing and coronary calcification between two age- and gender-matched cohorts of South Asian and Caucasian symptomatic angina patients. METHODS: We identified 101 symptomatic angina patients of South Asian origin who had undergone CT angiography and calcium scoring, and compared them with 101 age and gender matched Caucasian patients. RESULTS: South Asians had a greater mean number of arterial segments with both obstructive and non-obstructive plaque than Caucasians (p=0.006 and p=0.0003, respectively) and higher prevalence of triple-vessel disease (p=0.0004). Similarly, South Asians had a higher mean CAC score (p<0.0001) and the percentage of South Asians with CAC>0 and in all categories of CAC score 100-1000 were also higher, as was the number of arterial segments with calcified and non-calcified plaque. These results were more marked in patients aged >50 but in those ≤ 50, Caucasians showed a higher mean number of diseased segments (p=0.019), with non-obstructive plaque (p=0.02), possibly suggesting that Caucasians are likely to have more diffuse atherosclerosis at an earlier age. CAC prevalence and severity in this age-group were not significantly different between South Asians and Caucasians. CONCLUSION: Despite similar conventional risk factors for CAD, symptomatic South Asians seem to have more aggressive and diffuse arterial calcification compared to Caucasians. These differences are more profound above the age of 50, suggesting potential genetic or other risk factors yet to be determined.

Differences in clinical profile of individuals with severe and markedly elevated coronary artery calcification detected by electron beam computed tomography.

Although several studies have demonstrated the association between coronary artery calcification (CAC) and coronary artery disease events, the underlying mechanism has not been fully elucidated. Furthermore, extensive CAC still remains a poorly understood phenomenon. The objective of this study is to determine the clinical characteristics and differences between 831 asymptomatic individuals with very high CAC scores (CACS ≥ 1000) and 497 asymptomatic individuals with CAC scores of 400 to 999. Individuals with CACS ≥ 1000 were more likely to have hypertension ([HTN]; P = .0004), hypercholesterolemia (P = .0001), diabetes mellitus ([DM] P = .005), and high body mass index ([BMI]; P = .03) compared with individuals with CACS = 400-999. On multivariable analysis, age (P < .0001) and BMI (P = .01) were found to be significant risk factors for the presence of very high CAC. While for males, age (P < .0001), hypercholesterolemia (P = .001), DM (P = .002), and obesity (P = .003) were independent risk factors; in females only HTN (P = .04) was independent risk factor.

Evaluation of fipronil spot-on in the treatment of flea allergic dermatitis in dogs.

The purpose of this study was to evaluate the effectiveness of treatment with 10 per cent fipronil solution for controlling signs of flea allergic dermatitis in dogs under field conditions. Thirty-one client-owned dogs with flea allergic dermatitis were treated with three monthly applications of 10 per cent fipronil solution. Flea counts and pruritus were significantly reduced at all post-treatment visits. At the final visit, on day 90, flea counts were reduced by 98 per cent, and pruritus was reduced or eliminated in 84 per cent of the study dogs. Dermatological lesion scores for erythema, crusts, scales and papules were also significantly improved by the final visit. The overall assessment of efficacy on day 90 was 'excellent' to 'good' for 87 per cent of the study dogs. The results demonstrate that treatment with monthly topical applications of 10 per cent fipronil solution is effective in reducing the prevalence and severity of signs of flea allergic dermatitis in dogs.

Effect of topical application of fipronil in cats with flea allergic dermatitis.

OBJECTIVE: To determine whether topical application of a 10% fipronil solution would control signs of flea allergic dermatitis in cats housed under natural conditions. DESIGN: Multicenter open clinical trial. ANIMALS: 42 client-owned cats with flea allergic dermatitis. PROCEDURES: Study cats along with all other cats and dogs living in the same houses were treated with 10% fipronil solution topically on days 0, 30, and 60. Flea counts and clinical assessments were performed on study cats on days 0, 14, 30, 60, and 90. RESULTS: Percentage reductions in geometric mean flea counts on days 14, 30, 60, and 90, compared with day-0 geometric mean count, were 75, 73, 85, and 94%, respectively. Pruritus score was significantly improved at each examination after day 0, and pruritus was reduced or eliminated in 31 of 40 (78%) cats at the final examination. Similarly, scores for severity of miliary dermatitis and alopecia were significantly improved at each examination, except for alopecia score on day 14. Overall treatment efficacy, assessed on day 90, was excellent for 28 (70%) cats, good for 6 (15%), moderate for 3 (7.5%), and poor for 3 (7.5%). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that monthly topical application of fipronil is effective for treatment of flea allergic dermatitis in cats housed under natural conditions.

Multiple-center study of reduced-concentration triamcinolone topical solution for the treatment of dogs with known or suspected allergic pruritus.

OBJECTIVE: To determine the efficacy of triamcinolone acetonide topical solution (TTS) in dogs for use in reduction of clinical signs of pruritic inflammatory skin diseases of a known or suspected allergic basis and to evaluate adverse effects associated with TTS administration. ANIMALS: 103 pruritic adult dogs with known or suspected allergic skin disease. PROCEDURE: Dogs were treated for 4 weeks with TTS or with vehicle solution (control dogs) in a multiple-center study. Clinical signs were scored by owners and by examining veterinarians before and after treatment. Blood samples obtained before and after treatment were subjected to routine hematologic and serum biochemical analyses. RESULTS: Treatment success, as defined by an improvement of at least 2 of 6 grades in overall clinical score, was evident in 35 of 52 (67%) TTS-treated dogs (mean improvement, 1.98) and 12 of 51 (24%) control dogs (mean improvement, 0.29). For several criteria, TTS was significantly more effective than vehicle in reducing clinical signs. Minor alterations in hematologic determinations in TTS-treated dogs were limited to slightly lower total leukocyte, lymphocyte, and eosinophil counts after treatment. Minor adverse effects were reported by owners in 6 of 52 (12%) TTS-treated and 9 of 51 (18%) control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Triamcinolone used as a spray solution at a concentration approximately one-sixth the concentration of triamcinolone topical preparations currently available for veterinary use is effective for short-term alleviation of allergic pruritus in dogs. Adverse effects are few and mild and, thus, do not preclude prolonged treatment with the solution.

The abdominal aortic aneurysm sac after endoluminal exclusion: a medium-term morphologic follow-up based on volumetric technology.

PURPOSE: The purpose of this study was to evaluate the role of three-dimensional spiral computed tomographic angiography (SCTA) for the assessment of the feasibility and results of endoluminal repair of infrarenal abdominal aortic aneurysm. METHODS: Laboratory studies: Phantom glass aneurysms, filled with contrast, underwent SCTA. The correlation between SCTA and laboratory measurements of linear dimensions and volumes was highly accurate (r(2) = 1.0). CLINICAL STUDIES: From the first 7 patients that were suitable for endoluminal repair, the correlation between SCTA and angiocatheter measurements was 0.85 to 0.99 (P <.04), but there was poor agreement between individual values. As determined from the measurements by 2 experienced investigators, intraobserver and interobserver errors for volume calculation in 12 randomly chosen scans from a total of 120 scans were 5.7 and 4.4 mL, respectively (range of volumes, 100-403 mL). The conditions of 53 patients were judged suitable for endoluminal repair of which 30 patients reached 1 year or more follow-up. The median aneurysm neck length and diameter were 24.5 mm (range, 11.5-60.8 mm) and 23.4 mm (18.3-31.5 mm), respectively. The fate of the sac after endografting by two techniques (pre-expanded polytetrafluoroethylene [PTFE] fixed with Palmaz stents and endografts) was defined with three-dimensional SCTA. RESULTS: The sac volume after endografting by pre-expanded PTFE (n = 12 patients) showed a significant median increase (P =.02) from 129 mL before surgery to 141 mL at 5 days after the operation with no change at 6 (139 mL), 12 (137 mL), and 18 (159 mL) months later. With the endografts (n = 18), there was an initial increase in median volume at 5 days (179-194 mL; P =.02) and then a significant shrinkage at 6 (148 mL; P =.012) and 12 (94.9 mL; P =.02) months. CONCLUSION: Three-dimensional SCTA has been validated and is both precise and reliable. Interobserver and intraobserver errors are within acceptable ranges. Angiocatheter measurements are less accurate and may give misleading information when used for patient selection and endograft construction. The sac volume increased after endografting and later shrank in patients who were treated with endografts, but not in those patients treated with pre-expanded PTFE. We propose that three-dimensional SCTA should be regarded as the gold standard for linear and volumetric measurement for infrarenal abdominal aortic aneurysm.

Hepatic artery aneurysms: evaluation using three-dimensional spiral CT angiography.

Hepatic artery aneurysms are rare and frequently difficult to diagnose. Computed tomography (CT) and ultrasound rarely make the definitive diagnosis and angiography is usually required. We present three cases of hepatic artery aneurysms in which the definitive diagnosis was made on three-dimensional (3-D) spiral CT angiography-to our knowledge, this has not previously been described. Our experience shows that in many cases of hepatic artery aneurysm, conventional angiography need only be performed as a prelude to embolization.

Drug and AIDS education for Australian youth. The Get Real project.

It illustrates an approach to "at risk" youth which implicates the age group in planning and application, in an area where they are involved. It is a communication and health initiative which has achieved a good measure of success in Australia with the rock'n roll music sub culture. It reaches out not only in the drugs area but also in the area of AIDS.