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- Huang, C, et al.
(author)
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The inhomogeneous structure of water at ambient conditions
- 2009
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In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:36, s. 15214-15218
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Journal article (peer-reviewed)abstract
- Small-angle X-ray scattering (SAXS) is used to demonstrate the presence of density fluctuations in ambient water on a physical length-scale of approximate to 1 nm; this is retained with decreasing temperature while the magnitude is enhanced. In contrast, the magnitude of fluctuations in a normal liquid, such as CCl4, exhibits no enhancement with decreasing temperature, as is also the case for water from molecular dynamics simulations under ambient conditions. Based on X-ray emission spectroscopy and X-ray Raman scattering data we propose that the density difference contrast in SAXS is due to fluctuations between tetrahedral-like and hydrogen-bond distorted structures related to, respectively, low and high density water. We combine our experimental observations to propose a model of water as a temperature-dependent, fluctuating equilibrium between the two types of local structures driven by incommensurate requirements for minimizing enthalpy (strong near-tetrahedral hydrogen-bonds) and maximizing entropy (non-directional H-bonds and disorder). The present results provide experimental evidence that the extreme differences anticipated in the hydrogen-bonding environment in the deeply supercooled regime surprisingly remain in bulk water even at conditions ranging from ambient up to close to the boiling point.
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- Ho, Kok Sun, et al.
(author)
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Ileal pouch anal anastomosis for ulcerative colitis is feasible for septuagenarians.
- 2006
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In: Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland. - : Wiley. - 1462-8910. ; 8:3, s. 235-8
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Proctocolectomy and ileal pouch anal anastomosis (IPAA) has become the standard surgery for patients with mucosal ulcerative colitis (MUC). Although there is no absolute age limitation, there are concerns as to its use in elderly patients due to the risks of potential complications and poor function. The aim of this study was to assess the complications and outcome of patients over the age of 70 years with MUC who underwent IPAA. Results in these patients were compared to the results in a group of patients aged less than 70 years who had IPAA. METHODS: After Institutional Review Board approval, a retrospective review of the medical records of patients with MUC who underwent IPAA was undertaken. These patients were divided into four age groups: <30 years of age, 30-49 years, 50-69 years, >or=70 years. RESULTS: From 1989 to 2001, 330 patients underwent IPAA for preoperative clinical and histopathological and postoperative histopathologically confirmed MUC; 17 were aged>or=70 years. The mean hospital stay was 5.8 (SEM 0.7) days in the patients aged<70 years and 6.0 (SEM 0.4) days in the patients aged>or=70 years (P=0.911). Postoperative complications occurred in 39% of patients>or=70 years and in 40% in the <70 years group (P=0.08). Pouch failure occurred in two (11.8%) patients>or=70 years and in 6 (1.9%)<70 (P=0.2). CONCLUSION: IPAA is a safe and feasible option in MUC patients over the age of 70 with functional results similar to results seen in younger patients.
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- Ny, Lars, 1967, et al.
(author)
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A magnetic resonance imaging study of intestinal dilation in Trypanosoma cruzi-infected mice deficient in nitric oxide synthase.
- 2008
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In: The American journal of tropical medicine and hygiene. - 1476-1645. ; 79:5, s. 760-7
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Journal article (peer-reviewed)abstract
- Infection with Trypanosoma cruzi causes megasyndromes of the gastrointestinal (GI) tract. We used magnetic resonance imaging (MRI) to monitor alterations in the GI tract of T. cruzi-infected mice, and to assess the role of nitric oxide (NO) in the development of intestinal dilation. Brazil strain-infected C57BL/6 wild-type (WT) mice exhibited dilatation of the intestines by 30 days post-infection. Average intestine lumen diameter increased by 72%. Levels of intestinal NO synthase (NOS) isoforms, NOS2 and NOS3, were elevated in infected WT mice. Inflammation and ganglionitis were observed in all infected mice. Intestinal dilation was observed in infected WT, NOS1, NOS2, and NOS3 null mice. This study demonstrates that MRI is a useful tool to monitor intestinal dilation in living mice and that these alterations may begin during acute infection. Furthermore, our data strongly suggests that NO may not be the sole contributor to intestinal dysfunction resulting from this infection.
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| 10. |
- Svensson, Patrik, et al.
(author)
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Interaction Between Renal Function and Microalbuminuria for Cardiovascular Risk in Hypertension The Nordic Diltiazem Study
- 2008
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In: Hypertension. - 1524-4563. ; 52:1, s. 115-122
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Journal article (peer-reviewed)abstract
- We investigated whether renal function and microalbuminuria are independent predictors and whether any interaction exists between them, regarding future cardiovascular disease in hypertensive patients (n=10 881) followed for 4.5 years. The primary end points (PEs) were fatal and nonfatal myocardial infarction and stroke and other cardiovascular deaths. Creatinine and glomerular filtration rate (GFR), estimated using the formulas of the Modification of Diet in Renal Disease study group and Cockroft and Gault and in a subsample (n=4929) of microalbuminuria and interaction terms of microalbuminuria and renal function, were related to the risk of the PE using Cox proportional hazards model after full adjustment. Increased creatinine (P < 0.001), decreased GFR from Cockroft and Gault (P=0.001), and decreased GFR from the Modification of Diet in Renal Disease study group (P=0.001) were all independent risk factors for the PE. Stepwise exclusion of patients with the poorest renal function excluded the possibility that the relationship between decreasing renal function and the PE was driven only by patients with severely impaired renal function. Microalbuminuria and all 3 of the indices of renal function predicted the PE independent of each other. There was a significant interaction between microalbuminuria and GFR from Cockroft and Gault (P=0.040) in prediction of the PE. Both renal function and microalbuminuria add independent prognostic information regarding cardiovascular risk in hypertensive patients. The cardiovascular risk associated with microalbuminuria increases with a decline in GFR, as demonstrated by a significant interaction between microalbuminuria and GFR from Cockroft and Gault. Because estimation of the total cardiovascular risk is essential for the aggressiveness of risk factor interventions, simultaneous inclusion of GFR and microalbuminuria in global cardiovascular risk assessment is essential. (Hypertension. 2008;52:115-122.)
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