Showing papers by "University of Palermo published in 1998"
TL;DR: A single topic workshop combining a two-day symposium on liver microcirculation in health and diseases followed by a two day consensus workshop on portal hypertension and variceal bleeding was held to identify areas of critical importance in the understanding and treatment of portal hypertension.
404 citations
TL;DR: Airway inflammation in asthma and chronic bronchitis is associated with an imbalance between MMP-9 and TIMP-1 which may have a role in the pathogenesis of ECM remodeling and airflow obstruction.
Abstract: Asthma and chronic bronchitis are inflammatory diseases with extracellular matrix (ECM) remodeling and collagen deposition. Collagen homeostasis is controlled by metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). We evaluated MMP and TIMP balance in induced sputum of 10 control, 31 untreated asthmatic, and 16 chronic bronchitic subjects. We first performed zymographic analysis to identify the profile of MMPs. Zymography revealed a similar MMPs profile in all populations studied and that MMP-9 was the major enzyme released. We then measured, using enzyme immunoassay, the concentrations of MMP-9 and of its inhibitor TIMP-1 and evaluated whether airflow limitation may be associated with an imbalance between these enzymes. MMP-9 and TIMP-1 concentrations were greater in sputum of patients with asthma and chronic bronchitis than in control subjects. The molar ratio between MMP-9 and TIMP-1 was lower in asthmatics and chronic bronchitics than in control subjects, and positively correlated with FEV1 values. In asthma, MMP-9 levels were significantly correlated with the number of macrophages and neutrophils. This study shows that airway inflammation in asthma and chronic bronchitis is associated with an imbalance between MMP-9 and TIMP-1 which may have a role in the pathogenesis of ECM remodeling and airflow obstruction.
400 citations
TL;DR: In this article, the authors prove short time existence theorems for the Euler and Prandtl equations with analytic initial data in either two or three spatial dimensions, using abstract Cauchy-Kowalewski theorem.
Abstract: This is the first of two papers on the zero-viscosity limit for the incompressible Navier-Stokes equations in a half-space. In this paper we prove short time existence theorems for the Euler and Prandtl equations with analytic initial data in either two or three spatial dimensions. The main technical tool in this analysis is the abstract Cauchy-Kowalewski theorem. For the Euler equations, the projection method is used in the primitive variables, to which the Cauchy-Kowalewski theorem is directly applicable. For the Prandtl equations, Cauchy-Kowalewski is applicable once the diffusion operator in the vertical direction is inverted.
397 citations
TL;DR: In this article, the Navier-Stokes solution is constructed through a composite asymptotic expansion involving the solutions of the Euler and Prandtl equations, plus an error term.
Abstract: This is the second of two papers on the zero-viscosity limit for the incompressible Navier-Stokes equations in a half-space in either 2D or 3D. Under the assumption of analytic initial data, we construct solutions of Navier-Stokes for a short time which is independent of the viscosity. The Navier-Stokes solution is constructed through a composite asymptotic expansion involving the solutions of the Euler and Prandtl equations, which were constructed in the first paper, plus an error term. This shows that the Navier-Stokes solution goes to an Euler solution outside a boundary layer and to a solution of the Prandtl equations within the boundary layer. The error term is written as a sum of first order Euler and Prandtl corrections plus a further error term. The equation for the error term is weakly nonlinear; its linear part is the time dependent Stokes equation. This error equation is solved by inversion of the Stokes equation, through expressing the solution as a regular (Euler-like) part plus a boundary layer (Prandtl-like) part. The main technical tool in this analysis is the Abstract Cauchy-Kowalewski Theorem.
386 citations
TL;DR: In this paper, the influence of deposited silver upon the photocatalytic activity of titania in the rutile and anatase allotropic forms has been studied in three different reactions.
Abstract: The influence of deposited silver upon the photocatalytic activity of titania in the rutile and anatase allotropic forms has been studied in three different reactions. The common feature found for these three reactions was an electron transfer from illuminated TiO 2 to silver particles. In the first reaction (platinum photodeposition). it has been shown that the initial presence of metallic silver orientates the localization of subsequent Pt photodeposits with, in particular, a 100% selectivity to Pt deposition on top of silver particles or agglomerates previously deposited on anatase. In the second reaction (2-propanol oxidation), Ag deposit was found beneficial for the activity of rutile and detrimental for that of anatase. For rutile which is less active, silver helps for the electron-hole pair dissociation. By contrast, for anatase, the negatively charged Ag particles preferentially attract photoholes and become recombination centers, thus decreasing the photocatalytic activity. For the third reaction (dehydrogenation of 2-propanol), Ag/TiO 2 catalysts were found very poorly active, as expected for a group I-B metal. However, in the additional presence of platinum deposits, Pt/Ag/TiO 2 catalysts are as active as their Pt/TiO 2 homologues, thus confirming that Pt is deposited on top of silver with good electronic contacts between both metals. The three photocatalytic reactions have common electronic processes based on the photoelectron generation on titania and the subsequent electron transfer to the metal (s).
331 citations
TL;DR: In this paper, a methodology for solving numerically, for engineering purposes, boundary and initial boundary value problems by a peculiar approach characterized by the following features: the continuous formulation is centered on integral equations based on the combined use of single-layer and double-layer sources, so that the integral operator turns out to be symmetric with respect to a suitable bilinear form.
Abstract: This review article concerns a methodology for solving numerically, for engineering purposes, boundary and initial-boundary value problems by a peculiar approach characterized by the following features: the continuous formulation is centered on integral equations based on the combined use of single-layer and double-layer sources, so that the integral operator turns out to be symmetric with respect to a suitable bilinear form. The discretization is performed either on a variational basis or by a Galerkin weighted residual procedure, the interpolation and weight functions being chosen so that the variables in the approximate formulation are generalized variables in Prager’s sense. As main consequences of the above provisions, symmetry is exhibited by matrices with a key role in the algebraized versions; some quadratic forms have a clear energy meaning; variational properties characterize the solutions and other results, invalid in traditional boundary element methods enrich the theory underlying the computational applications. The present survey outlines recent theoretical and computational developments of the title methodology with particular reference to linear elasticity, elastoplasticity, fracture mechanics, time-dependent problems, variational approaches, singular integrals, approximation issues, sensitivity analysis, coupling of boundary and finite elements, and computer implementations. Areas and aspects which at present require further research are identified, and comparative assessments are attempted with respect to traditional boundary integral-elements. This article includes 176 references.
292 citations
TL;DR: In this article, numerical simulations of the flow field in baffled mixing tanks, based on three alternative methods, are presented and discussed, where the impeller is not explicitly simulated, and its effects are modelled by imposing suitable, empirically derived, boundary conditions to the external flow.
284 citations
TL;DR: In this paper, a new experimental technique for measuring average particle drag coefficients in turbulent media is presented based on a direct measurement, by means of a suitable residence time technique, of the settling velocity exhibited by a cloud of particles.
268 citations
TL;DR: Monte-Carlo simulations of a two-dimensional finite element model of a flood in the southern part of Sicily were used to explore the parameter space of distributed bed-roughness coefficients, using both a fuzzy-rule-based calibration and a calibration technique based upon normal and heteroscedastic distributions of the predicted residuals.
256 citations
TL;DR: The presence of the prothrombin A (20210) allele was investigated to determine whether the presence of this mutation was an independent, inherited risk factor for venous thrombosis.
Abstract: Background: A mutation in the prothrombin gene (G→A20210) has been associated with higher plasma prothrombin levels and an increased tendency for venous thrombosis. Objective: To determine whether ...
236 citations
Journal Article•
TL;DR: Since vesicles appear to promote the proteolytic cascade required for the localised degradation of the extracellular matrix, their shedding from cancer cells might represent an important feature of tumour progression.
Abstract: Cancer cells are known to shed extracellular membrane vesicles both in vitro and in vivo. To analyse their possible involvement in the metastatic behaviour of tumours, we measured the Matrigel invasion capability and amounts of vesicles shed by four human tumour cell lines (8701-BC, MCF-7, MDA-MB-231 and HT-1080), and by MCF-10A, an immortalised human breast cell line. The proteolytic activity content of vesicles was analysed by gelatin and casein zymographies. While MCF-10A cells do not release a measurable amount of vesicles, all tumour lines analysed, when cultured in presence of serum, shed vesicles rich in MMP-9. Other vesicle-associated proteinases include MMP-2 and uPA. Amounts and proteolytic activities of shed vesicles correlate with the in vitro invasiveness of cells. Since vesicles appear to promote the proteolytic cascade required for the localised degradation of the extracellular matrix, their shedding from cancer cells might represent an important feature of tumour progression.
TL;DR: This study suggests that a risk factor in 5qter is involved in both forms of CD (symptomatic and silent) and a factor on 11qter possibly differentiates the two forms.
Abstract: Celiac disease (CD), a malabsorption disorder of the small intestine, results from ingestion of gluten. The HLA risk factors involved in CD are well known but do not explain the entire genetic susceptibility. To determine the localization of other genetic risk factors, a systematic screening of the genome has been undertaken. The typing information of 281 markers on 110 affected sib pairs and their parents was used to test linkage. Systematic linkage analysis was first performed on 39 pairs in which both sibs had a symptomatic form of CD. Replication of the regions of interest was then carried out on 71 pairs in which one sib had a symptomatic form and the other a silent form of CD. In addition to the HLA loci, our study suggests that a risk factor in 5qter is involved in both forms of CD (symptomatic and silent). Furthermore, a factor on 11qter possibly differentiates the two forms. In contrast, none of the regions recently published was confirmed by the present screening.
TL;DR: In this article, the authors studied the asymptotic behavior of the sequence of codimensions of a PI-algebra over a field and showed that if A is finitely generated over F thenInv(A)=limn→∞ c n (A) always exists and is an integer.
TL;DR: It appears that bisphosphonates and, in particular, intravenous Disodium Pamidronate are not only able to slow down the progression of the disease and to reduce the onset of skeletal complications but also have an analgesic effect and the possibility of improving the quality of life in patients with osteolytic metastases due to breast cancer and multiple myeloma.
Abstract: Metastatic bone disease is a frequent cause of morbidity in advanced cancer patients with a subsequent high incidence of skeletal complications (fractures, hypercalcemia, spinal cord compression) and severe pain. The osteolytic process is mainly characterized by an osteoclastic activity of bone resorption and inflammatory activity provoked by various cytokines and prostaglandins. Bisphosphonates represent a new class of drugs with inhibitory activity on bone resorption and on inflammatory processes which revealed themselves to be efficacious in a series of clinical conditions such as tumour-induced hypercalcemia, Paget's disease, osteoporosis and metastatic bone disease. The aim of this review of the literature is to show the analgesic efficacy of the different bisphosphonates in phase III studies carried out on patients with metastatic bone disease. Medline and Cancerlit database from January 1984 to February 1998 have been considered. From the analysis of the published studies it appears that bisphosphonates and, in particular, intravenous Disodium Pamidronate, are not only able to slow down the progression of the disease and to reduce the onset of skeletal complications but also have an analgesic effect and the possibility of improving the quality of life, above all in patients with osteolytic metastases due to breast cancer and multiple myeloma. Bisphosphonates represent a further valid therapy to add to an already consolidated list of therapies such as radio, chemo and endocrine therapy, analgesic drugs, orthopaedic and physiatric in the pain management of patients with bone metastases. These drugs meet with the patients' compliance, are well-tolerated as well as having a good cost/efficacy profile. It still remains to be seen if the newer and more potent bisphosphonates such as Ibandronate and Zoledronate can be administered differently from the intravenous route such as by mouth or by patch which are readily accepted by the patient and, moreover, if these more potent drugs are able to prevent or delay the onset and/or the progression of bone metastases.
TL;DR: In this article, some computational aspects on the generation procedure of n -variate wind velocity vectors are discussed in detail, and decompositions of the power spectral density matrix are also discussed showing the physical significance of eigenquantities of this matrix.
TL;DR: Several types of lithium ion conducting polymer electrolytes have been synthesized by hot-pressing homogeneous mixtures of the components, namely, poly(ethylene oxide) (PEO) as the polymer matrix, lithium trifluoromethane sulfonate (LiCF{sub 3}SO{ sub 3}), and lithium tetrafluoroborate (LiBF{sub 4}), respectively, as the lithium salt, and lithium gamma-aluminate {gamma}-LiAlO{sub 2}, as a ceramic filler.
Abstract: Several types of lithium ion conducting polymer electrolytes have been synthesized by hot-pressing homogeneous mixtures of the components, namely, poly(ethylene oxide) (PEO) as the polymer matrix, lithium trifluoromethane sulfonate (LiCF{sub 3}SO{sub 3}), and lithium tetrafluoroborate (LiBF{sub 4}), respectively, as the lithium salt, and lithium gamma-aluminate {gamma}-LiAlO{sub 2}, as a ceramic filler. This preparation procedure avoids any step including liquids so that plasticizer-free, composite polymer electrolytes can be obtained. These electrolyte have enhanced electrochemical properties, such as an ionic conductivity of the order of 10{sup {minus}4} S/cm at 80--90 C and an anodic breakdown voltage higher than 4 V vs. Li. In addition, and most importantly, the combination of the dry feature of the synthesis procedure with the dispersion of the ceramic powder, concurs to provide these composite electrolytes with an exceptionally high stability with the lithium metal electrode. In fact, this electrode cycles in these dry polymer electrolytes with a very high efficiency, i.e., approaching 99%. This in turn suggests the suitability of the electrolytes for the fabrication of improved rechargeable lithium polymer batteries.
TL;DR: Achange in the relative prevalence of hepatitis virus markers among hepatocellular carcinoma cases was demonstrated, reflecting a significant change in the rate of HBV endemicity in the Italian population.
TL;DR: Delayed clearance of serum HBsAg in compensated cirrhosis B and relation to interferon alpha therapy and disease prognosis is studied.
TL;DR: In this article, the authors used a series of grand canonical Monte Carlo calculations for a small number of state points and combined the results to obtain the phase behavior of a system over a range of temperatures and densities.
Abstract: Histogram reweighting Monte Carlo simulations were used to obtain polymer/solvent phase diagrams for lattice homopolymers of chain lengths up to r = 1000 monomers. The simulation technique was based on performing a series of grand canonical Monte Carlo calculations for a small number of state points and combining the results to obtain the phase behavior of a system over a range of temperatures and densities. Critical parameters were determined from mixed-field finite-size scaling concepts by matching the order parameter distribution near the critical point to the distribution for the three-dimensional Ising universality class. Calculations for the simple cubic lattice (coordination number z = 6) and for a high coordination number version of the same lattice (z = 26) were performed for chain lengths significantly longer than those in previous simulation studies. The critical temperature was found to scale with a chain length following the Flory−Huggins functional form. For the z = 6 lattice, the extrapolat...
Journal Article•
TL;DR: The release of selected areas of plasma membranes enriched with MMP-9 and beta1 integrins indicates that membrane vesicle shedding from tumor cells plays an important role in the directional proteolysis of the extracellular matrix during cellular migration.
Abstract: The shedding of membrane vesicles from the cell surface is a vital process considered to be involved in cell-cell and cell-matrix interactions and in tumor progression. By immunoelectron microscopic analysis of surface replicas of 8701-BC human breast carcinoma cells, we observed that membrane vesicles shed from plasma membranes contained densely clustered gelatinase B [matrix metalloproteinase 9 (MMP-9)], β1 integrins, and human lymphocyte antigen class I molecules. By contrast, α-folate receptor was uniformly distributed on the smooth cell membrane and shedding areas. Both cell surface clustering of selected molecules and membrane vesicle release were evident only when cells were cultured in the presence of serum. Vesicle shedding occurred preferentially at the edge or along narrow protrusions of the cell. Specific accumulation of proMMP-9 and active forms of MMP-9 in shed vesicles was also demonstrated by gelatin zymography. In addition, Western blotting analysis showed the presence of a large amount of proMMP-9/tissue inhibitor of metalloproteinase 1 complex. The release of selected areas of plasma membranes enriched with MMP-9 and β1 integrins indicates that membrane vesicle shedding from tumor cells plays an important role in the directional proteolysis of the extracellular matrix during cellular migration. The presence of human lymphocyte antigen class I antigens suggests a mechanism for tumor cells to escape from immune surveillance.
TL;DR: In addition to the markers of insulin resistance and smoking habit, gene variants of PAI-1 and ACE account for a significant portion of the between-individual variability of circulating PAi-1 antigen concentrations in a general population without clinical evidence of atherosclerosis.
Abstract: Plasminogen activator inhibitor-1 (PAI-1) plasma levels have been consistently related to a polymorphism (4G/5G) of the PAI-1 gene. The renin-angiotensin pathway plays a role in the regulation of PAI-1 plasma levels. An insertion (I)/deletion (D) polymorphism of the angiotensin-converting enzyme (ACE) gene has been related to plasma and cellular ACE levels. In 1032 employees (446 men and 586 women; 22 to 66 years old) of a hospital in southern Italy, we investigated the association between PAI-1 4G/5G and the ACE I/D gene variants and plasma PAI-1 antigen levels. None of the individuals enrolled had clinical evidence of atherosclerosis. In univariate analysis, PAI-1 levels were significantly higher in men (P<.001), alcohol drinkers (P<.001), smokers (P=.009), and homozygotes for the PAI-1 gene deletion allele (4G/4G) (P=.012). Multivariate analysis documented the independent effect on PAI-1 plasma levels of body mass index (P<.001), triglycerides (P<.001), sex (P<.001), PAI-1 4G/5G polymorphism (P=.019), smoking habit (P=.041), and ACE I/D genotype (P=.042). Thus, in addition to the markers of insulin resistance and smoking habit, gene variants of PAI-1 and ACE account for a significant portion of the between-individual variability of circulating PAI-1 antigen concentrations in a general population without clinical evidence of atherosclerosis.
TL;DR: An automaton accepting L and built from the language M and if M is the set of minimal forbidden words of a single word ν, the automaton turns out to be the factor automaton of ν (the minimal automatonAccepting theSet of factors ofν), which yields a nontrivial upper bound on the number of minimal prohibitions of a word.
TL;DR: In induced sputum obtained from asthmatic and chronic bronchitis patients, the levels of both total and active elastase were significantly increased as compared with those of control subjects and healthy smokers and were significantly correlated with the percenta...
Abstract: Asthma and chronic bronchitis are inflammatory diseases associated with remodeling of the extracellular matrix (ECM). Elastin, a major component of the ECM in the airways, has been previously found to be disrupted in asthma and chronic bronchitis. This study was aimed at evaluating whether elastin disruption might be associated with an imbalance between elastase (active and total) and α1-proteinase inhibitor ( α1-PI), the main inhibitor of elastase. We measured elastase and α1-PI in induced sputum obtained from 16 control subjects, 10 healthy smokers, 19 asthmatic patients, and 10 chronic bronchitis patients. We also assessed the possible origin of elastase, evaluating its levels in sputum with reference to differential cell counts. We found that in induced sputum obtained from asthmatic and chronic bronchitis patients, the levels of both total and active elastase were significantly increased as compared with those of control subjects and healthy smokers and were significantly correlated with the percenta...
TL;DR: In this article, the authors investigated the morphology of gaseous flows on the basis of three-dimensional gas-dynamical calculations of interacting binaries of different types (cataclysmic variables and low-mass X-ray binaries).
Abstract: The results of numerical simulation of mass transfer in semidetached non-magnetic binaries are presented. We investigate the morphology of gaseous flows on the basis of three-dimensional gas-dynamical calculations of interacting binaries of different types (cataclysmic variables and low-mass X-ray binaries). We find that taking into account a circumbinary envelope leads to significant changes in the stream–disc morphology. In particular, the obtained steady-state self-consistent solutions show an absence of impact between the gas stream from the inner Lagrangian point L1 and the forming accretion disc. The stream deviates under the action of the gas of the circumbinary envelope, and does not cause the shock perturbation of the disc boundary (traditional hotspot). At the same time, the gas of the circumbinary envelope interacts with the stream and causes the formation of an extended shock wave, located on the stream edge. We discuss the implication of this model without hotspot (but with a shock wave located outside the disc) for interpretation of the observations. The comparison of synthetic light curves with observations proves the validity of the discussed gas-dynamical model without hotspot. We have also considered the influence of the circumbinary envelope on the mass transfer rate in semidetached binaries. The obtained features of flow structure in the vicinity of L1 show that the gas of the circumbinary envelope plays an important role in the flow dynamics, and that it leads to significant (in order of magnitude) increase of the mass transfer rate. The most important contribution to this increase is from the stripping of the mass-losing star atmosphere by interstellar gas flows. The parameters of the formed accretion disc are also given in the paper. We discuss the details of the obtained gaseous flow structure for different boundary conditions on the surface of mass-losing star, and show that the main features of this structure in semidetached binaries are the same for different cases. The comparison of gaseous flow structure obtained in two- and three-dimensional approaches is presented. We discuss the common features of the flow structures and the possible reasons for revealed differences.
TL;DR: In this article, the authors present a decision making support method based on fuzzy logic for renewable energy diffusion strategies, which takes into account the uncertainties of all the specific assessments, the qualitative nature of some indexes, the weight of the preferences or willingness systems of the decision maker.
01 Nov 1998
TL;DR: In this paper, a GA was used to identify the parameters of an induction motor model using genetic algorithms, where the inverter supplying the motor is directly accessible for control of the conduction sequences of its power switches.
Abstract: The paper deals with methods of identification of the parameters of an induction motor model using genetic algorithms. It is supposed that the inverter supplying the motor is directly accessible for control of the conduction sequences of its power switches. This makes it possible to carry out a test consisting of a transient from standstill to steady-state operation at a given frequency and successive free motion to standstill. During this test, data are acquired referring to stator voltages, and currents and speed. Then, a genetic algorithm is employed with the aim of determining the mechanical and electrical parameters of the model, so as to reproduce the input-output behaviour of a real open-loop system.
TL;DR: The hypothesis that the PAI-1 4G/5G polymorphism to some extent accounts for the risk of CAD related to a family history of coronary heart disease supported.
Abstract: A family history of ischemic events is a major determinant of coronary artery disease (CAD) Plasma levels of plasminogen activator inhibitor 1 (PAI-1) modulate this risk A deletion/insertion polymorphism within the PAI-1 locus (4G/5G) affects the expression of this gene We investigated the relationship between the PAI-1 4G/5G polymorphism in 1179 healthy employees of our institution and the occurrence of CAD in their first-degree relatives A family history of documented ischemic coronary disease was assessed by a modified WHO questionnaire The PAI-1 4G/5G polymorphism was evaluated by polymerase chain reaction and endonuclease digestion The group with a first-degree relative who had suffered from a coronary ischemic episode had a higher number of homozygotes for the deleted allele (4G/4G) of the PAI-1 gene compared with subjects without such a family history (odds ratio [OR] = 162, 95% confidence interval [CI]=117 to 225; P=005) The frequency of the 4G allele was abnormally high as well (OR=129, 95% CI=104 to 160; P=025) The individuals with a positive family history were older (P<001) and exhibited a higher body mass index (P=033) and total cholesterol levels (P<001) than those without In a multiple logistic regression analysis, age (P=006) and PAI-1 4G/4G (P=024) independently contributed to a family history of coronary heart disease, with 4G/4G carriers exhibiting a more frequent family history of CAD (OR=160) The PAI-1 4G/5G polymorphism to some extent thus accounts for the risk of CAD related to a family history for such an event These findings support the hypothesis that the 4G variant is a transmissible coronary risk factor
TL;DR: In this paper, a nonlocal thermodynamic theoretical framework is provided as a basis for a consistent formulation of gradient-dependent plasticity in which a scalar internal variable measuring the material isotropic hardening/softening state is the only nonlocal variable.
Abstract: A nonlocal thermodynamic theoretical framework is provided as a basis for a consistent formulation of gradient-dependent plasticity in which a scalar internal variable measuring the material isotropic hardening/softening state is the only nonlocal variable. The main concepts of this formulation are: i) the ‘regularization operator’, of differential nature, which governs the relation between the above nonlocal variable and a related local variable (scalar measure of plastic strain) and confers a unified character to the proposed formulation (this transforms into a formulation for nonlocal plasticity if the regularization operator has an integral nature); ii) the ‘nonlocality residual’, which accounts for energy exchanges between different particles at the microstructural level as a consequence of the hardening/softening diffusion processes within the body; and iii) the (nonambiguous) ‘constitutive’ boundary conditions, which must be satisfied at points of the boundary surface of any (finite) region of the body where an irreversible deformation mechanism takes place (e.g. shear band). The plastic yielding laws for gradient plasticity are established with their domain and boundary equations, and their consistency with the nonlocal Clausius-Duhem inequality is assessed as well. Also, a suitable nonlocal-form maximum intrinsic dissipation theorem is provided, and the response problem of a continuous set of material particles to a given total strain rate field studied. Points of agreement and disagreement between this theory and the related literature are indicated, also via a case-study bar in uniaxial tension for which the analytical solution is worked out.
TL;DR: The results of 3D hydrodynamic simulation of mass transfer in semidetached binaries of different types (cataclysmic variables and low-mass X-ray binaries) are presented in this paper.
Abstract: The results of 3D hydrodynamic simulation of mass transfer in semidetached binaries of different types (cataclysmic variables and low-mass X-ray binaries) are presented.
We find that taking into account of a circumbinary envelope leads to significant changes in the stream-disc morphology. In particular, the obtained steady-state self-consistent solutions show an absence of impact between gas stream from the inner Lagrangian point L1 and forming accretion disc. The stream deviates under the action of gas of circumbinary envelope, and does not cause the shock perturbation of the disc boundary (traditional `hotspot'). At the same time, the gas of circumbinary envelope interacts with the stream and causes the formation of an extended shock wave, located on the stream edge. We discuss the implication of this model without `hotspot' (but with a shock wave located outside the disc) for interpretation of observations. The comparison of synthetic light curves with observations proves the validity of the discussed hydrodynamic model without `hotspot'.
We also consider the influence of a circumbinary envelope on the mass transfer rate in semidetached binaries. The obtained features of flow structure in the vicinity of L1 show that the gas of circumbinary envelope plays an important role in the flow dynamics, and that it leads to significant (in order of magnitude) increasing of the mass transfer rate.
The comparison of gaseous flows structure obtained in 2D and 3D approaches is presented. We discuss the common features of the flow structures and the possible reasons of revealed differences.
TL;DR: Methadone is a drug of indisputable value in the treatment of cancerPain, and an unbalanced focus on the risks of inappropriate use rather than the benefits should not compromise the use of a relevant alternative to morphine in the management of cancer pain.
Abstract: PURPOSEThe aim of this study was to evaluate the analgesic and adverse effects and the doses of methadone in comparison to morphine.PATIENTS AND METHODSA prospective randomized study was performed in a sample of 40 patients with advanced cancer who required strong opioids for their pain management. Patients were treated with sustained-release morphine or methadone in doses titrated against the effect administered two or three times daily according to clinical need. Opioid doses, adjuvant medications, symptoms associated with opioid therapy, pain intensity, and pain mechanisms were recorded. The opioid escalation indices in percentage (OEI%) and milligrams (OEImg) were calculated. The effective analgesic score (EAS) that monitors the analgesic consumption-pain ratio was also calculated at fixed weekly intervals.RESULTSdifferences in pain intensity were found. Patients treated with methadone reported values of OEI significantly less than those observed in patients treated with morphine. Seven patients in th...