23 research outputs found

    Mechanics of cooling liquids by forced evaporation in bubbles

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    Injecting a non-dissolvable gas into a saturated liquid results in sub-cooling of the liquid due to forced evaporation into the bubble. Previous studies assumed the rate of evaporation of liquid into the bubble to be independent of the degree of sub-cooling. In our study we quantify the bubble growth by direct observation using high speed imaging and prove that this hypothesis is not true. A phenomenological model of the bubble growth as a function of the degree of sub-cooling is developed and we find excellent agreement between the measurements and theory. This bubble cooling process is employed in cooling a liquid. By identification of all heat flows, we can well describe the cool down curve using bubble cooling. Bubble cooling provides an alternative cooling method for liquids without the use of complicated cooling techniques

    Cam morphology is strongly and consistently associated with development of radiographic hip osteoarthritis throughout 4 follow-up visits within 10 years

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    Objective: To determine the association between cam morphology and the development of radiographic hip osteoarthritis (RHOA) at four time points within 10-year follow-up. Design: The nationwide prospective Cohort Hip and Cohort Knee study includes 1002 participants aged 45–65 years with 2-, 5-, 8-, and 10-year follow-ups. The associations of cam morphology (alpha angle &gt;60°) and large cam morphology (alpha angle &gt;78°) in hips free of osteoarthritis at baseline (Kellgren &amp; Lawrence (KL) grade &lt;2) with the development of both incident RHOA (KL grade≥2) and end-stage RHOA (KL grade≥3) were estimated using logistic regression with generalized estimating equation at each follow-up and using Cox regression over 10 years, adjusted for age, sex, and body mass index.Results: Both cam morphology and large cam morphology were associated with the development of incident RHOA at all follow-ups with adjusted Odd Ratios (aORs) ranging from 2.7 (95% Confidence interval 1.8–4.1) to 2.9 (95% CI 2.0–4.4) for cam morphology and ranging from 2.5 (95% CI 1.5–4.3) to 4.2 (95% CI 2.2–8.3) for large cam morphology. For end-stage RHOA, cam morphology resulted in aORs ranging from 4.9 (95% CI 1.8–13.2) to 8.5 (95% CI 1.1–64.4), and aORs for large cam morphology ranged from 6.7 (95% CI 3.1–14.7) to 12.7 (95% CI 1.9–84.4). Conclusions: Cam morphology poses the hip at 2–13 times increased odds for developing RHOA within a 10-year follow-up. The association was particularly strong for large cam morphology and end-stage RHOA, while the strength of association was consistent over time.</p

    Quality of Life 1 Year After Laparoscopic Sleeve Gastrectomy Versus Laparoscopic Roux-en-Y Gastric Bypass: a Randomized Controlled Trial Focusing on Gastroesophageal Reflux Disease

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    Introduction: Bariatric surgery is the only treatment option that achieves sustained weight loss in obese patients and that also has positive effects on obesity-related comorbidities. Laparoscopic sleeve gastrectomy (LSG) seems to achieve equal weight loss as laparoscopic Roux-en-Y gastric bypass (LRYGB), but there is still much debate about the quality of life (QOL) after LSG, mainly concerning the association with gastroesophageal reflux. Our hypothesis is that QOL after LSG is comparable with QOL after LRYGB. Materials and Methods: Between February 2013 and February 2014, 150 patients were randomized to undergo either LSG or LRYGB in our clinic. Differences in QOL were compared between groups by using multiple QOL questionnaires at follow-up moments preoperatively and 2 and 12 months after surgery. Results: After 12 months of follow-up, 128 patients had returned the questionnaires. Most QOL questionnaires showed significant improvement in scores between the preoperative moment and after 12 months of follow-up. The Gastroesophageal Reflux Disease Questionnaire (GerdQ) score deteriorated in the LSG group after 2 months, but recovered again after 12 months. After 2 months of follow-up, the mean GerdQ score was 6.95 ± 2.14 in the LSG group versus 5.50 ± 1.49 in the LRYGB group (p < 0.001). After 1 year, the mean GerdQ score was 6.63 ± 2.26 in the LSG group and 5.60 ± 1.07 in the LRYGB group (p = 0.001). Conclusion: This randomized controlled trial shows that patients who underwent LSG have significantly higher GerdQ scores at both 2 and 12 months postoperatively than patients who underwent LRYGB, whereas overall QOL did not differ significantly

    Cohort profile: Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) – an international consortium of prospective cohort studies with individual participant data on hip osteoarthritis

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    Purpose: Hip osteoarthritis (OA) is a major cause of pain and disability worldwide. Lack of effective therapies may reflect poor knowledge on its aetiology and risk factors, and result in the management of end-stage hip OA with costly joint replacement. The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium was established to pool and harmonise individual participant data from prospective cohort studies. The consortium aims to better understand determinants and risk factors for the development and progression of hip OA, to optimise and automate methods for (imaging) analysis, and to develop a personalised prediction model for hip OA. Participants: World COACH aimed to include participants of prospective cohort studies with ≥200 participants, that have hip imaging data available from at least 2 time points at least 4 years apart. All individual participant data, including clinical data, imaging (data), biochemical markers, questionnaires and genetic data, were collected and pooled into a single, individual-level database. Findings to date: World COACH currently consists of 9 cohorts, with 38 021 participants aged 18–80 years at baseline. Overall, 71% of the participants were women and mean baseline age was 65.3±8.6 years. Over 34 000 participants had baseline pelvic radiographs available, and over 22 000 had an additional pelvic radiograph after 8–12 years of follow-up. Even longer radiographic follow-up (15–25 years) is available for over 6000 of these participants. Future plans: The World COACH consortium offers unique opportunities for studies on the relationship between determinants/risk factors and the development or progression of hip OA, by using harmonised data on clinical findings, imaging, biomarkers, genetics and lifestyle. This provides a unique opportunity to develop a personalised hip OA risk prediction model and to optimise methods for imaging analysis of the hip

    Cohort profile: Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) – an international consortium of prospective cohort studies with individual participant data on hip osteoarthritis

    Get PDF
    Purpose Hip osteoarthritis (OA) is a major cause of pain and disability worldwide. Lack of effective therapies may reflect poor knowledge on its aetiology and risk factors, and result in the management of end-stage hip OA with costly joint replacement. The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium was established to pool and harmonise individual participant data from prospective cohort studies. The consortium aims to better understand determinants and risk factors for the development and progression of hip OA, to optimise and automate methods for (imaging) analysis, and to develop a personalised prediction model for hip OA. Participants World COACH aimed to include participants of prospective cohort studies with ≥200 participants, that have hip imaging data available from at least 2 time points at least 4 years apart. All individual participant data, including clinical data, imaging (data), biochemical markers, questionnaires and genetic data, were collected and pooled into a single, individual-level database. Findings to date World COACH currently consists of 9 cohorts, with 38 021 participants aged 18–80 years at baseline. Overall, 71% of the participants were women and mean baseline age was 65.3±8.6 years. Over 34 000 participants had baseline pelvic radiographs available, and over 22 000 had an additional pelvic radiograph after 8–12 years of follow-up. Even longer radiographic follow-up (15–25 years) is available for over 6000 of these participants

    Adding false-profile radiographs improves detection of developmental dysplasia of the hip, data from the CHECK cohort.

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    The aim of this study was to determine the additional value of the false-profile (FP) view radiograph in the diagnosis of developmental dysplasia of the hip (DDH), as compared with an anteroposterior (AP) pelvic radiograph only, and evaluate the correlation between the Wiberg-lateral center edge angle (W-LCEA) and Wiberg-anterior center edge angle (W-ACEA). We used baseline data from a nationwide prospective cohort study (Cohort Hip and Cohort Knee). DDH was quantified on AP pelvic and FP hip radiographs using semi-automatic measurements of the W-LCEA and W-ACEA. A threshold of <20° was used to determine DDH for both the W-LCEA and the W-ACEA. The proportion of DDH only present on the FP view determined the FP view additional value. The correlation between the W-LCEA and W-ACEA was determined. In total 720 participants (1391 hips) were included. DDH was present in 74 hips (5.3%), of which 32 were only present on the FP view radiograph (43.2%). The Pearson correlation coefficient between W-LCEA and W-ACEA of all included hips was 0.547 (95% confidence interval: 0.503–0.591) and 0.441 (95% confidence interval: 0.231–0.652) in hips with DDH. A mean difference of 9.4° (SD 8.09) was present between the W-LCEA and the W-ACEA in the hips with DDH. There is a strong additional value of the FP radiograph in the diagnosis of DDH. Over 4 out of 10 (43.2%) individuals’ DDH will be missed when only using the AP radiograph. In hips with DDH a moderate correlation between W-LCEA and W-ACEA was calculated indicating that joints with normal acetabular coverage on the AP view can still be undercovered on the FP view

    Pincer morphology is not associated with hip osteoarthritis unless hip pain is present

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    OBJECTIVE: To assess the relationship between pincer morphology and radiographic hip osteoarthritis (RHOA) over 2-,5-,8- and 10-years follow-up, and to study the interaction between pincer morphology and pain.METHODS: Individuals from the prospective CHECK cohort were drawn. Anteroposterior pelvic and false profile radiographs were obtained. Hips free of definite RHOA (Kellgren and Lawrence (KL) 0 or 1) at baseline were included. Pincer morphology: lateral or anterior center edge angle, or both ≥40° at baseline. Incident RHOA: KL ≥2 or total hip replacement at follow-up. Multivariable logistic regression with generalized estimating equations estimated the associations at follow-up. Associations were expressed as unadjusted (OR) and adjusted odds ratios (aOR) with 95% confidence intervals (95% CI). An interaction term was added to investigate whether pincer morphology had a different effect on symptomatic hips.RESULTS: Incident RHOA developed in 69 hips (5%) at 2 years, 178 hips (14%) at 5 years, 279 hips (24%) at 8 years, and in 495 hips (42%) at 10 years follow-up. No significant associations were found between pincer morphology and incident RHOA (aOR's 0.35 (95% CI 0.06-2.15) -1.50 (95% CI 0.94-2.38)). Significant interactions between pain and anterior pincer morphology in predicting incident RHOA were found at 5- 8- and 10 years follow-up (ORs 1.97 (1.03-3.78) - 3.41 (1.35-8.61)).CONCLUSION: No associations were found between radiographic pincer morphology and incident RHOA at any follow-up moment. Anteriorly located pincer morphology with hip pain however was significantly associated with incident RHOA. This highlights the importance of studying symptoms and hip morphology simultaneously.</p

    Pincer morphology is not associated with hip osteoarthritis unless hip pain is present

    No full text
    OBJECTIVE: To assess the relationship between pincer morphology and radiographic hip osteoarthritis (RHOA) over 2-,5-,8- and 10-years follow-up, and to study the interaction between pincer morphology and pain.METHODS: Individuals from the prospective CHECK cohort were drawn. Anteroposterior pelvic and false profile radiographs were obtained. Hips free of definite RHOA (Kellgren and Lawrence (KL) 0 or 1) at baseline were included. Pincer morphology: lateral or anterior center edge angle, or both ≥40° at baseline. Incident RHOA: KL ≥2 or total hip replacement at follow-up. Multivariable logistic regression with generalized estimating equations estimated the associations at follow-up. Associations were expressed as unadjusted (OR) and adjusted odds ratios (aOR) with 95% confidence intervals (95% CI). An interaction term was added to investigate whether pincer morphology had a different effect on symptomatic hips.RESULTS: Incident RHOA developed in 69 hips (5%) at 2 years, 178 hips (14%) at 5 years, 279 hips (24%) at 8 years, and in 495 hips (42%) at 10 years follow-up. No significant associations were found between pincer morphology and incident RHOA (aOR's 0.35 (95% CI 0.06-2.15) -1.50 (95% CI 0.94-2.38)). Significant interactions between pain and anterior pincer morphology in predicting incident RHOA were found at 5- 8- and 10 years follow-up (ORs 1.97 (1.03-3.78) - 3.41 (1.35-8.61)).CONCLUSION: No associations were found between radiographic pincer morphology and incident RHOA at any follow-up moment. Anteriorly located pincer morphology with hip pain however was significantly associated with incident RHOA. This highlights the importance of studying symptoms and hip morphology simultaneously.</p
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