12 research outputs found
A counter-rotating Couette apparatus to study deformation of a sub-millimeter sized particle in shear flow
We describe a new counter-rotating Couette apparatus that has been developed for deformation studies of single sub-millimeter sized particles in shear flow. New features are the adaption to the low viscosities of water-based systems and temperature control of the device. The inner to outer radius ratio of the cylinders used is 0.9785 and the height to width aspect ratio of the gap is 4.0, while the inner radius is 100 mm. Because of the limited particle size a high mechanical accuracy of the Couette geometry is necessary. The swing of the inner cylinder is less than 2 μm and that of the outer cylinder less than 4 μm. We achieved this by carefully choosing the design parameters of the aerostatic bearing and the coupling between cylinder and motor unit. Furthermore, special drive units give a shear rate resolution of 0.018 s−1, while the maximum shear rate is 100 s−1. For a liquid viscosity on the order of 1 mPas the effective maximum shear rate is 30 s−1. We have shown that deformations as small as (L−B)/(L+B) ≈ 0.01 of giant bilayer vesicles (typical radius 10 μm) with length L and width B can be observed with our device
Measuring system for complex shear modulus of liquids using torsionally vibrating quartz crystals
In rheology, torsionally vibrating quartz crystals are in use to determine dynamic shear moduli of liquids in the sonic and ultrasonic frequency range. A computer controlled measuring system using such crystals is described. The main advantages of this system are high measuring speed with respect to the manual AC bridge method and on-line data reduction. As an illustration measurements of a solution of polystyrene in toluene in the 10-100 kHz range are presented
Lymph node retrieval during esophagectomy with and without neoadjuvant chemoradiotherapy: prognostic and therapeutic impact on survival.
Item does not contain fulltextOBJECTIVES: We aimed to examine the association between total number of resected nodes and survival in patients after esophagectomy with and without nCRT. BACKGROUND: Most studies concerning the potentially positive effect of extended lymphadenectomy on survival have been performed in patients who underwent surgery alone. As nCRT is known to frequently "sterilize" regional nodes, it is unclear whether extended lymphadenectomy after nCRT is still useful. METHODS: Patients from the randomized CROSS-trial who completed the entire protocol (ie, surgery alone or chemoradiotherapy + surgery) were included. With Cox regression models, we compared the impact of number of resected nodes as well as resected positive nodes on survival in both groups. RESULTS: One hundred sixty-one patients underwent surgery alone, and 159 patients received multimodality treatment. The median (interquartile range) number of resected nodes was 18 (12-27) and 14 (9-21), with 2 (1-6) and 0 (0-1) resected positive nodes, respectively. Persistent lymph node positivity after nCRT had a greater negative prognostic impact on survival as compared with lymph node positivity after surgery alone. The total number of resected nodes was significantly associated with survival for patients in the surgery-alone arm (hazard ratio per 10 additionally resected nodes, 0.76; P=0.007), but not in the multimodality arm (hazard ratio 1.00; P=0.98). CONCLUSIONS: The number of resected nodes had a prognostic impact on survival in patients after surgery alone, but its therapeutic value is still controversial. After nCRT, the number of resected nodes was not associated with survival. These data question the indication for maximization of lymphadenectomy after nCRT.1 november 201
A Valid and reliable method for measuring the kicking accuracy of soccer players
BACKGROUND: Initial results of the ChemoRadiotherapy for Oesophageal cancer followed by Surgery Study (CROSS) comparing neoadjuvant chemoradiotherapy plus surgery versus surgery alone in patients with squamous cell carcinoma and adenocarcinoma of the oesophagus or oesophagogastric junction showed a significant increase in 5-year overall survival in favour of the neoadjuvant chemoradiotherapy plus surgery group after a median of 45 months' follow-up. In this Article, we report the long-term results after a minimum follow-up of 5 years. METHODS: Patients with clinically resectable, locally advanced cancer of the oesophagus or oesophagogastric junction (clinical stage T1N1M0 or T2-3N0-1M0, according to the TNM cancer staging system, sixth edition) were randomly assigned in a 1:1 ratio with permuted blocks of four or six to receive either weekly administration of five cycles of neoadjuvant chemoradiotherapy (intravenous carboplatin [AUC 2 mg/mL per min] and intravenous paclitaxel [50 mg/m(2) of body-surface area] for 23 days) with concurrent radiotherapy (41.4 Gy, given in 23 fractions of 1.8 Gy on 5 days per week) followed by surgery, or surgery alone. The primary endpoint was overall survival, analysed by intention-to-treat. No adverse event data were collected beyond those noted in the initial report of the trial. This trial is registered with the Netherlands Trial Register, number NTR487, and has been completed. FINDINGS: Between March 30, 2004, and Dec 2, 2008, 368 patients from eight participating centres (five academic centres and three large non-academic teaching hospitals) in the Netherlands were enrolled into this study and randomly assigned to the two treatment groups: 180 to surgery plus neoadjuvant chemoradiotherapy and 188 to surgery alone. Two patients in the neoadjuvant chemoradiotherapy group withdrew consent, so a total of 366 patients were analysed (178 in the neoadjuvant chemoradiotherapy plus surgery group and 188 in the surgery alone group). Of 171 patients who received any neoadjuvant chemoradiotherapy in this group, 162 (95%) were able to complete the entire neoadjuvant chemoradiotherapy regimen. After a median follow-up for surviving patients of 84.1 months (range 61.1-116.8, IQR 70.7-96.6), median overall survival was 48.6 months (95% CI 32.1-65.1) in the neoadjuvant chemoradiotherapy plus surgery group and 24.0 months (14.2-33.7) in the surgery alone group (HR 0.68 [95% CI 0.53-0.88]; log-rank p=0.003). Median overall survival for patients with squamous cell carcinomas was 81.6 months (95% CI 47.2-116.0) in the neoadjuvant chemoradiotherapy plus surgery group and 21.1 months (15.4-26.7) in the surgery alone group (HR 0.48 [95% CI 0.28-0.83]; log-rank p=0.008); for patients with adenocarcinomas, it was 43.2 months (24.9-61.4) in the neoadjuvant chemoradiotherapy plus surgery group and 27.1 months (13.0-41.2) in the surgery alone group (HR 0.73 [95% CI 0.55-0.98]; log-rank p=0.038). INTERPRETATION: Long-term follow-up confirms the overall survival benefits for neoadjuvant chemoradiotherapy when added to surgery in patients with resectable oesophageal or oesophagogastric junctional cancer. This improvement is clinically relevant for both squamous cell carcinoma and adenocarcinoma subtypes. Therefore, neoadjuvant chemoradiotherapy according to the CROSS trial followed by surgical resection should be regarded as a standard of care for patients with resectable locally advanced oesophageal or oesophagogastric junctional cancer. FUNDING: Dutch Cancer Foundation (KWF Kankerbestrijding)