The paper discusses whether bi-oriented PVC, obtained by modifying the structures of polymers chains to enhance the mechanical properties of unplasticized PVC, could successfully replace metallic ...materials in industrial applications where radioactive fluids are processed and an intense field of ionizing radiation is present. Tests have been carried out in order to study the behavior of a commercial bi-oriented PVC when exposed to ionizing radiations. A numerical simulation allows comparing the effects of radiation expected on the pipe in nuclear industry applications with those resulting from the irradiation tests. Contamination and decontamination tests of bi-oriented PVC in contact with a radioactive solution have been performed too. Results show that the bi-oriented PVC can withstand high β and γ radiation doses (up to 100kGy) without showing significant degradation in mechanical properties; bi-orientation of polymers chains in the bulk of material is not affected even to much higher doses (250kGy); the decontamination of the material is satisfactory. The results suggest that tested commercial bi-oriented PVC could be considered in nuclear industry applications.
•Bi-oriented PVC specimens have been irradiated with γ rays and β particles.•Up to 100kGy mechanical properties of bi-oriented PVC are practically unchanged.•A numerical simulation allows estimating PVC piping minimum lifetime.•Achieved decontamination factors of PVC piping are satisfactory.•Results suggest bi-oriented PVC piping is suitable for nuclear applications.
Aseptic meningitis is a rare adverse drug reaction, reported with non-steroidal anti-inflammatory agents (NSAIDs) and with miscellaneous drugs such as trimethoprim-sulfamethoxazole (TMP-SMX). The ...most common clinical findings reported are fever, headache, stiffness and altered level of consciousness. We report a case of aseptic meningitis related to TMP-SMX ingestion that caused severe derangements of the patient's vital signs, requiring Intensive Care Unit admittance. The prompt diagnosis and discontinuation of the drug resulted in complete recovery. We examine the case according to the literature on this topic. We conclude that, since the signs and symptoms of this unusual drug reaction may mimic those of central nervous system infection, the clinician should consider this etiology when he is faced with a patient with suspected meningoencephalitis, especially if the latter has already been treated at home with unknown drugs. Further studies should investigate the pathogenetic mechanism of TMP-SMX-induced aseptic meningitis.
Hierarchical decomposition of multiscale skeletons Borgefors, G.; Ramella, G.; Sanniti Di Baja, G.
IEEE transactions on pattern analysis and machine intelligence,
11/2001, Letnik:
23, Številka:
11
Journal Article
Recenzirano
The paper presents a novel procedure to hierarchically decompose a multiscale discrete skeleton. The skeleton is a linear pattern representation that is generally recognized as a good shape ...descriptor. For discrete images, the discrete skeleton is often preferable. Multiresolution representations are convenient for many image analysis tasks. Our resulting skeleton decomposition shows two different types of hierarchy. The first type of hierarchy is one of different scales, as the original pattern is converted into an AND-pyramid and the skeleton is computed for each resolution level. The second type of hierarchy is established at each level of the pyramid by identifying and ranking skeleton subsets according to their permanence, where permanence is a property intrinsically related to local pattern thickness. To achieve the decomposition, both bottom-up and top-down analysis in the sense of moving from higher to lower resolution and vice versa are used. The bottom-up analysis is used to ensure that a part of the skeleton that is connected at a higher resolution level is also connected (if at all present) in the next, lower resolution level. The top-down analysis is used to build the permanence hierarchy ranking the skeleton components. Our procedure is based on the use of (3/spl times/3) local operations in digital images, so it is fast and easy to implement. This skeleton decomposition procedure is most effective on patterns having different thickness in different regions. A number of examples of decompositions of multiscale skeletons (with and without loops) are shown. The skeletons are, in most cases, nicely decomposed into meaningful parts. The procedure is general and not limited to any specific application.
The isolated perfused rat kidney (IPK) model was used to assess initial renal function after 24 h preservation in 3 different cold storage solutions: EuroCollins (EC), a solution prepared according ...to the formulation of Belzer's solution (High-K+ UW) and a high Na(+)-low K+ Belzer UW solution (High-Na+ UW). GFR and FRNa were measured after 24 h cold storage in each of the solutions during 60 min, and were compared to values obtained in a control group in which renal function was measured immediately after the kidneys had been harvested. ATP and CP were measured in fresh renal tissue, in kidneys preserved for 24 h in each solution, in control IPK, and in reperfused IPK after they had been preserved for 24 h. Main results showed that preservation in either solution caused a dramatic decrease in GFR and in FRNa within the first 60 min following reperfusion of cold-stored kidneys. However FRNa was significantly higher in the High-Na+ UW group. ATP and CP content were decreased to approximately 10% of basal values in all experimental groups after cold-storage. Normothermic reperfusion of IPK after cold-storage induced a restoration of ATP levels, but CP content decreased further. There was no significant difference in ATP and CP content between cold-storage solutions, nor any correlation between metabolic and functional parameters.
Background/Aims
: In humans, the role of liver cell dysplasia as a preneoplastic lesion is still debated. A prospective, long-term, multicenter study was performed to establish whether liver cell ...dysplasia in cirrhosis is associated with an increased risk for hepatocellular carcinoma (HCC).
Methods
: A cohort of 307 consecutive patients in whom liver cirrhosis was diagnosed by histology was investigated for development of HCC at 6-month intervals by ultrasonography and determination of α-fetoprotein levels.
Results
: At enrollment, liver cell dysplasia was found in 75 patients (24%) and in 53% (
P < 0.01) of those positive for hepatitis B surface antigen (HBsAg). After a mean follow-up of 46 months, HCC was detected in 45 cases, and it was significantly more frequent in patients with liver cell dysplasia (
P < 0.01) and HBsAg-serum positivity (
P < 0.01). Multivariate analysis showed that liver cell dysplasia was the most important risk factor correlated with HCC development. HBsAg positivity and age over 60 years were also independent risk factors for HCC.
Conclusions
: These results indicate that liver cell dysplasia is a major risk factor for HCC, and it should be looked for carefully by pathologists in liver biopsy specimens to identify patients requiring more intensive observation.
Hierarchical decomposition of multiscales skeletons Borgefors, G; Ramella, G; Di Baja, G S
IEEE transactions on pattern analysis and machine intelligence,
11/2001, Letnik:
23, Številka:
11
Journal Article
Recenzirano
This paper presents a new produce to hierarchically decompose a multiscale discrete skeleton. The skeleton is a linear pattern representation that is generally recognized as a good shape descriptor. ...For discrete images, the discrete skeleton is often preferable. Multiresolution representations are convenient for many image analysis tasks. Our resulting skeleton decomposition shows two different types of hierarchy. The first type of hierarchy is one of different scales, as the original pattern is converted into an AND-pyramid and the skeleton is computed for each resolution level. The second type of hierarchy is established at each level of the pyramid by identifying and ranking skeleton subsets according to their permanence, where permanence is a property intrinsically related to local pattern thickness. To achieve the decomposition, both bottom-up and to-down analysis in the sense of moving from higher to lower resolution and vice versa are used. The bottom-up analysis is used to ensure that a part of the skeleton that is connected at a higher resolution level is also connected (if at all present) in the next, lower resolution level. The top-down analysis is used to build the permanence hierarchy ranking the skeleton components. Our procedure is based on the use of (3 x 3) local operations in digital images, so it is fast and easy to implement. This skeleton decomposition procedure is most effective on patterns having different thickness in different regions. A number of examples of decompositions of multiscale skeletons (with and without loops) will be shown. The skeletons are, in most cases, nicely decomposed into meaningful parts. The procedure is general and not limited to any specific application.
Numerous hypothalamic peptides are involved in the control of eating behaviour. We assessed plasma and cerebrospinal fluid (CSF) levels of SRIH, beta-endorphin (beta-EP), CRH, NPY and GHRH in a group ...of massively obese patients and in normal weight subjects. In the obese patients, CSF SRIH and beta-EP levels were significantly reduced and increased, respectively, compared with controls (20.6 +/- 2.62, mean +/- s.e.m., vs 34.5 +/- 2.14 pg/ml, P < 0.05, for SRIH and 111.2 +/- 5.00 vs 80.4 +/- 5.32 pg/ml, P < 0.001, for beta-EP). Considering the data of obese and control subjects altogether, SRIH and beta-EP concentrations correlated negatively and positively, respectively, with BMI values (r = -0.641, P < 0.005 and r = 0.518, P < 0.05). No significant differences were observed in CSF levels of CRH, NPY and GHRH between obese and normal weight subjects, though GHRH levels were close to the assay sensitivity. CSF concentrations of CRH were positively correlated with those of SRIH in obese patients (r = 0.60, P < 0.05) and with those of NPY both in obese (r = 0.69, P < 0.02) and in control subjects (r = 0.83, P < 0.005). Plasma levels of SRIH, beta-EP, NPY and GHRH did not differ significantly in the two groups of subjects; plasma CRH was undetectable. Our results argue against the hypothesis of an enhanced SRIH tone as the cause of impaired GH secretion in obese patients, a primary defect in GHRH or GH release seems more likely. Moreover, they emphasise the importance of an increased tone of endogenous opioids in the pathophysiology of human obesity.
In a double-blind study, 40 patients scheduled for saphenectomy or inguinal hernioplasty were randomly assigned to treatment with nimesulide (200mg 3 times daily) or diclofenac (100mg 3 times daily) ...administered rectally. Therapy with either drug resulted in significantly less pain, oedema and hyperaemia, and resolution of mild fever. No adverse reactions attributable to treatment were observed.
Extracellular types (high-Na) of cold-storage solution (CSS) have been shown to be more effective in preserving kidneys than intracellular CSS (high-K). On the other hand, calcium entry blockers ...(CEB) have been demonstrated to improve graft function when administered after and/or prior to transplantation. The ischaemia reperfusion syndrome involves, in part, an alteration in intracellular calcium metabolism that induces an increase in renal vascular resistances (RVR) and other cellular dysfunction, and high-K CSS per se are vasoconstrictive. Since CEB act via a modification in intracellular calcium metabolism on vascular smooth muscle, glomerular, and tubular cells, we evaluated the actual benefit on CEB on kidneys preserved in Belzer's CSS (K-UW) and a high-Na version of Belzer's CSS (Na-UW).
The isolated perfused rat kidney (IPK) was used, first as a vascular bed to test the effects of CSS on RVR, and the influence of nifedipine. Second, the recovery function of the IPK was assessed by GFR and tubular Na reabsorption, after 24 h preservation in K-UW and Na-UW, with or without nifedipine. Results were compared with a control group in which renal function was measured without prior cold-storage.
K-UW but not Na-UW induced an increase in RVR when flushed into the kidney. This vasoconstriction is prevented by nifedipine. K-UW CSS was more deleterious to renal function than Na-UW. Addition of nifedipine to the flush, the CSS for 24 h, and to the normothermic reperfusate further improved recovery function of the IPK cold stored in Na-UW but not in K-UW, without any modification of RVR.
Nifedipine may be of potential effect in attenuating ischaemic injury by a mechanism which does not involve its vasodilatory properties.
Coarse-to-fine skeletons from grey-level pyramids Borgefors, G.; Ramella, G.; Sanniti di Baja, G.
Proceedings. Fourteenth International Conference on Pattern Recognition (Cat. No.98EX170),
1998, Letnik:
1
Conference Proceeding
Coarse-to-fine skeletons of digital patterns in binary images are computed on a grey-level pyramid. This is built in such a way that pattern shape and topology are preserved at all resolution levels, ...as faithfully as possible. A key problem is spurious holes, created at lower resolutions by region merging, that would originate spurious loops in coarse skeletons. This is solved by a novel technique exploiting the grey-level pyramid.
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