| 161. |
- Kostic, Srdjan, 1958, et al.
(författare)
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Pneumatic dilatation or laparoscopic cardiomyotomy in the management of newly diagnosed idiopathic achalasia. Results of a randomized controlled trial
- 2007
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Ingår i: World journal of surgery. - : Springer Science and Business Media LLC. - 0364-2313 .- 1432-2323. ; 31:3, s. 470-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The most effective therapeutic strategy in newly diagnosed achalasia is yet to be established. Therefore we designed a study in which pneumatic dilatation was compared to laparoscopic cardiomyotomy to which was added a partial posterior fundoplication. PATIENTS AND RESULTS: A series of 51 patients (24 males, mean age 44 years) were randomly allocated to the therapeutic modalities (dilatation = 26, surgery = 25). All patients were followed for at least 12 months, and during that period the pneumatic dilatations strategy had significantly more treatment failures (P = 0.04). Only minor differences emerged between the study groups when symptoms, dysphagia scorings, and quality-of-life assessments were evaluated 12 months after initiation of therapy. CONCLUSIONS: Laparoscopic myotomy was found to be superior to an endoscopic balloon dilatation strategy in the treatment of achalasia when studied during the first 12 months after treatment.
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| 162. |
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| 163. |
- Kutty, F. P. A., et al.
(författare)
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Numerical analysis of slot die coating of nanocellulosic materials
- 2020
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Ingår i: TAPPI Journal. - : TAPPI Press. - 0734-1415. ; 19:11, s. 575-582
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Tidskriftsartikel (refereegranskat)abstract
- Nanocellulosic coatings as a food packaging material are of commercial interest due to their nontox-ic nature, renewability, and excellent barrier properties. Complex shear-thinning rheology poses challenges in designing and sizing equipment to pump, mix, and process the suspension and actual coating process. This study aims to determine the effectiveness of computational fluid dynamics (CFD) in predicting nanocellulosic suspension flow in light of existing rheological data. We employ and compare three distinct rheological models to characterize the rheology and flow of nanocellulose suspensions through a slot die coater, where the model parameters are established from existing slot rheometry measurements. A volume-of-fluid (VoF) based finite volume method is employed to simulate the flow in a slot die operated in an unconventional metering mode. Results with the Casson model predict the presence of unyielded regions in the flow, which was not captured using the power law model. These stagnation regions will incur coatability issues stemming from flow intermittencies and lead to poten-tial defects in the coating layer, including fracture. The results suggest that a rheological model that includes yield stress should be considered while modeling such flows. A need for better rheological data to model nanocellulosic flows, especially at high consistencies and shear rates, is also highlighted. Application: This work identifies and clarifies the challenges to be addressed when considering industrial scale nanocellulose coating of paperboard.
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| 164. |
- Kutty, F. P. A., et al.
(författare)
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Numerical analysis of slot die coating of nanocellulosic materials
- 2021
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Ingår i: TAPPICon LIVE 2021. - : TAPPI Press. - 9781713848370 ; , s. 63-73
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Konferensbidrag (refereegranskat)abstract
- Nanocellulosic coatings as a food-packaging material are of commercial interest due to their non-toxic nature, renewability, and excellent barrier properties. Complex shear-thinning rheology poses challenges in designing and sizing equipment to pump, mix, and process the suspension and actual coating process. This study aims to determine the effectiveness of computation fluid dynamics (CFD) in predicting nanocellulosic suspension flow in light of existing rheological data. We employ and compare three distinct rheological models to characterize the rheology and flow of nanocellulose suspensions through a slot-die coater, where the model parameters are established from existing slot-rheometry measurements. A volume-of-fluid (VoF) based finite volume method is employed to simulate the flow in a slot-die operated in an unconventional metering mode. Results with the Casson model predicts the presence of unyielded regions in the flow, which was not captured using the power-law model. These stagnation regions will incur coatability issues stemming from flow intermittencies and lead to potential defects in the coating layer, including fracture. The results suggest that a rheological model that includes yield stress should be considered while modeling such flows. A need for better rheological data to model nanocellulosic flows, especially at high consistencies and shear-rates, is also highlighted.
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| 165. |
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| 166. |
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| 167. |
- Linder, Gustav, et al.
(författare)
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Validation of data quality in the Swedish National Register for Oesophageal and Gastric Cancer
- 2016
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Ingår i: British Journal of Surgery. - : Oxford University Press (OUP). - 0007-1323 .- 1365-2168. ; 103:10, s. 1326-1335
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Swedish National Register for Oesophageal and Gastric Cancer (NREV) was launched in 2006. Data are reported at diagnosis (diagnostic survey), at the time of surgery (surgical survey) and at first outpatient follow-up (follow-up survey). The aim of this study was to evaluate data originating from NREV in terms of comparability, completeness, accuracy and timeliness. Methods: Coding routines were compared with international standards and completeness was evaluated by means of a 5-year (2009–2013) comparison with mandatory national registers. Validity was tested by comparison with reabstracted data from source medical records in 400 patients chosen randomly with stratification for hospital size and catchment area population. Timeliness of registration was described. Results: Coding routines followed national and international guidelines. Compared with the Swedish Cancer Registry from 2009 to 2013, 6069 (95·5 per cent) of 6354 patients were registered in NREV at the time of data extraction. Of 60 variables investigated, 10 966 of 12 035 original entries were correct in the reabstraction, resulting in an exact agreement of 91·1 per cent in the register. There were 782 (6·5 per cent) incorrect and 287 (2·4 per cent) missing entries. Median time to registration was 3·9, 3·4 and 4·1 months for diagnostic, surgical and follow-up surveys respectively. Conclusion: NREV has reached a position with good coverage of those with the relevant diagnoses, and contains comparable and valid data. Quality data on each variable are available. Timeliness is an area with potential for improvement.
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| 168. |
- Loizou, L, et al.
(författare)
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Computed tomography staging of pancreatic cancer : a validation study addressing interobserver agreement
- 2013
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Ingår i: Pancreatology (Print). - : Elsevier BV. - 1424-3903 .- 1424-3911. ; 13:6, s. 570-575
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/OBJECTIVES:Ductal adenocarcinoma in the head of the pancreas (PDAC) is usually unresectable at the time of diagnosis due to the involvement of the peripancreatic vessels. Various preoperative classification algorithms have been developed to describe the relationship of the tumor to these vessels, but most of them lack a surgically based approach. We present a CT-based classification algorithm for PDAC based on surgical resectability principles with a focus on interobserver variability.METHODS:Thirty patients with PDAC undergoing pancreaticoduodenectomy were examined by using a standard CT protocol. Nine radiologists, representing three different levels of expertise, evaluated the CT examinations and the tumors were classified into four categories (A-D) according to the proposed system. For the interobserver agreement, the Intraclass Correlation Coefficient (ICC) was estimated.RESULTS:The overall ICC was 0.94 and the ICCs among the trainees, experienced radiologists, and experts were 0.85, 0.76, and 0.92, respectively. All tumors classified as category A1 showed no signs of vascular invasion at surgery. In category A2, 40% of the tumors had corresponding infiltration and required resection of the superior mesenteric vein/portal vein (SMV/PV). One of two tumors in category B2 and two of three in category C required SMV/PV resection. All six patients in category D had both arterial and venous involvement.CONCLUSION:There is almost perfect agreement among radiologists with different levels of expertise in regards to the local staging of PDAC. For tumors in a more advanced preoperative category, an increased risk for vascular involvement was noticed at surgery.
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| 169. |
- Loizou, L., et al.
(författare)
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Radiological assessment of local resectability status in patients with pancreatic cancer: Interreader agreement and reader performance in two different classification systems
- 2018
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Ingår i: European Journal of Radiology. - : Elsevier BV. - 0720-048X .- 1872-7727. ; 106, s. 69-76
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To assess the interreader agreement and reader performance in the evaluation of patients with pancreatic cancer (PC) in two classification systems of local resectability status prior to initiation of therapy, namely the National Comprehensive Cancer Network (NCCN) and Karolinska classification system (KCS). Methods: In this ethics review board-approved retrospective study, six radiologists independently evaluated pancreatic CT-examinations of 30 patients randomly selected from a tertiary referral centre's multidisciplinary tumour board database. Based on well-defined criteria of tumour-vessel relationship, each patient was assigned to one of three NCCN and six KCS categories. We assessed the intraclass correlation coefficient (ICC) and compared the percentages of correct tumour classification of the six readers in both systems (Chi-square test; a P-value < 0.05 was considered significant). The standard of reference was a consensus evaluation of CT-examinations by three readers not involved in the image analysis. Results: The ICC for NCCN and KCS was 0.82 and 0.84, respectively (very strong agreement). The percentages of correct tumour classification at NCCN and KCS were 53-83% and 30-57%, respectively, with no statistically significant differences in the overall reader comparison per classification system. In pair-wise comparison between readers for NCCN/KCS, there were statistically significant differences between reader 5 vs. readers 4 (P = 0.012) and 3 (P = 0.045)/ reader 5 vs. reader 4 (P = 0.037). Conclusion: Interreader agreement in both PC classification systems is very strong. NCCN may be advantageous in terms of reader performance compared to KCS.
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