524 research outputs found
Shear-Induced Stress Relaxation in a Two-Dimensional Wet Foam
We report on experimental measurements of the flow behavior of a wet,
two-dimensional foam under conditions of slow, steady shear. The initial
response of the foam is elastic. Above the yield strain, the foam begins to
flow. The flow consists of irregular intervals of elastic stretch followed by
sudden reductions of the stress, i.e. stress drops. We report on the
distribution of the stress drops as a function of the applied shear rate. We
also comment on our results in the context of various two-dimensional models of
foams
Can agricultural cultivation methods influence the healthfulness of crops for foods
The aim of the current study was to investigate if there are any health effects of long-term consumption of organically grown crops using a rat model. Crops were retrieved over two years from along-term field trial at three different locations in Denmark, using three different cultivation systems(OA, organic based on livestock manure; OB, organic based on green manure; and C, conventional with mineral fertilizers and pesticides)with two field replicates. The cultivation system had an impact on the nutritional quality, affecting γ-tocopherol, some amino acids, and fatty acid composition. Additionally, the nutritional quality was affected by harvest year and location. However, harvest year and location rather than cultivation system affected the measured health biomarkers. In conclusion, the differences in dietary treatments composed of ingredients from different cultivation systems did not lead to significant differences in the measured health biomarkers, except for a significant difference in plasma IgGl evels
Nonlinear Stress Fluctuation Dynamics of Sheared Disordered Wet Foam
Sheared wet foam, which stores elastic energy in bubble deformations, relaxes
stress through bubble rearrangements. The intermittency of bubble
rearrangements in foam leads to effectively stochastic drops in stress that are
followed by periods of elastic increase. We investigate global characteristics
of highly disordered foams over three decades of strain rate and almost two
decades of system size. We characterize the behavior using a range of measures:
average stress, distribution of stress drops, rate of stress drops, and a
normalized fluctuation intensity. There is essentially no dependence on system
size. As a function of strain rate, there is a change in behavior around shear
rates of .Comment: accepted to Physical Review
Tumor immunosurveillance in human cancers
Until now, the anatomic extent of tumor (TNM classification) has been by far the most important factor to predict the prognosis of colorectal cancer patients. However, in recent years, data collected from large cohorts of human cancers demonstrated that the immune contexture of the primary tumors is an essential prognostic factor for patients’ disease-free and overall survival. Tumoral and immunological markers predicted by systems biology methods are involved in the shaping of an efficient immune reaction and can serve as targets for novel therapeutic approaches. Global analysis of tumor microenvironment showed that the nature, the functional orientation, the density, and the location of adaptive immune cells within distinct tumor regions influence the risk of relapse events. The density and the immune cell location within the tumor have a prognostic value that is superior to the TNM classification, and tumor invasion is statistically dependent on the host-immune reaction. Thus, the strength of the immune reaction could advance our understanding of cancer evolution and have important consequences in clinical practice
Bedside rationing by general practitioners: A postal survey in the Danish public healthcare system
<p>Abstract</p> <p>Background</p> <p>It is ethically controversial whether medical doctors are morally permitted to ration the care of their patients at the bedside. To explore whether general practitioners in fact do ration in this manner we conducted a study within primary care in the Danish public healthcare system. The purpose of the study was to measure the extent to which general practitioners (GPs) would be willing to factor in cost-quality trade-offs when prescribing medicine, and to discover whether, and if so to what extent, they believe that patients should be informed about this.</p> <p>Methods</p> <p>Postal survey of 600 randomly selected Danish GPs, of which 330 responded to the questionnaire. The Statistical Package for the Social Sciences (SPSS, version 14.0) was used to produce general descriptive statistics. Significance was calculated with the McNemar and the chi-square test. The main outcome measures of the study were twofold: an assessment of the proportion of GPs who, in a mainly hypothetical setting, would consider cost-quality trade-offs relevant to their clinical decision-making given their economic impact on the healthcare system; and a measure of the extent to which they would disclose this information to patients.</p> <p>Results</p> <p>In the hypothetical setting 95% of GPs considered cost-quality trade-offs relevant to their clinical decision-making given the economic impact of such trade-offs on the healthcare system. In all 90% stated that this consideration had been relevant in clinical decision-making within the last month. In the hypothetical setting 55% would inform their patients that they considered a cost-quality trade-off relevant to their clinical decisions given the economic impact of such trade-offs on the healthcare system. The most common reason (68%) given for not wanting to inform patients about this matter was the belief that the information would not prove useful to patients. In the hypothetical setting cost-quality trade-offs were considered relevant significantly more often in connection with concerns about costs to the patient (86%) than they were in connection with concerns about costs to the healthcare system (55%; p < 0.001).</p> <p>Conclusion</p> <p>Although readiness to consider cost-quality trade-offs relevant to clinical decisions is prevalent among GPs in Denmark, only half of GPs would disclose to patients that they consider this relevant to their clinical decision-making. The results of this study raise two important ethical problems. First, under Danish law physicians are required to inform patients about all equal treatments. The fact that only a few GPs would inform their patients about all of the relevant treatments therefore seems to contravene Danish law. Second, it is ethically controversial that physicians act as economic gatekeepers.</p
Abnormal increase in urinary aquaporin-2 excretion in response to hypertonic saline in essential hypertension
<p>Abstract</p> <p>Background</p> <p>Dysregulation of the expression/shuttling of the aquaporin-2 water channel (AQP2) and the epithelial sodium channel (ENaC) in renal collecting duct principal cells has been found in animal models of hypertension. We tested whether a similar dysregulation exists in essential hypertension.</p> <p>Methods</p> <p>We measured urinary excretion of AQP2 and ENaC β-subunit corrected for creatinine (u-AQP2<sub>CR</sub>, u-ENaC<sub>β-CR</sub>), prostaglandin E2 (u-PGE<sub>2</sub>) and cyclic AMP (u-cAMP), fractional sodium excretion (FE<sub>Na</sub>), free water clearance (C<sub>H2O</sub>), as well as plasma concentrations of vasopressin (AVP), renin (PRC), angiotensin II (Ang II), aldosterone (Aldo), and atrial and brain natriuretic peptide (ANP, BNP) in 21 patients with essential hypertension and 20 normotensive controls during 24-h urine collection (baseline), and after hypertonic saline infusion on a 4-day high sodium (HS) diet (300 mmol sodium/day) and a 4-day low sodium (LS) diet (30 mmol sodium/day).</p> <p>Results</p> <p>At baseline, no differences in u-AQP2<sub>CR </sub>or u-ENaC<sub>β-CR </sub>were measured between patients and controls. U-AQP2<sub>CR </sub>increased significantly more after saline in patients than controls, whereas u-ENaC<sub>β-CR </sub>increased similarly. The saline caused exaggerated natriuretic increases in patients during HS intake. Neither baseline levels of u-PGE<sub>2</sub>, u-cAMP, AVP, PRC, Ang II, Aldo, ANP, and BNP nor changes after saline could explain the abnormal u-AQP2<sub>CR </sub>response.</p> <p>Conclusions</p> <p>No differences were found in u-AQP2<sub>CR </sub>and u-ENaC<sub>β-CR </sub>between patients and controls at baseline. However, in response to saline, u-AQP2<sub>CR </sub>was abnormally increased in patients, whereas the u-ENaC<sub>β-CR </sub>response was normal. The mechanism behind the abnormal AQP2 regulation is not clarified, but it does not seem to be AVP-dependent.</p> <p>Clinicaltrial.gov identifier</p> <p><a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=00345124">NCT00345124</a>.</p
- …