Range Of R-values Research Articles

Immune activation is associated with reduced skeletal muscle mass and physical function in chronic heart failure

Background Chronic heart failure is characterized by immune activation and increased circulating levels of cytokines. Whether humoral factors contribute to the peripheral manifestations of the heart failure syndrome, such as muscle atrophy and reduced physical work capacity, however, is not clear. Methods We measured circulating cytokines (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6)), their soluble receptors (sTNF-α RII, IL-6sR), markers of immune activation (C-reactive protein (CRP)), muscle mass, aerobic capacity and muscle strength in 10 patients with heart failure (mean ± S.E.; 63 ± 3 years) and 11 controls (70 ± 3 years). Results Heart failure patients exhibited decreased aerobic capacity ( P < 0.01) and leg muscle strength ( P < 0.05). Reduced muscle strength persisted in heart failure patients after statistical adjustment for differences in skeletal muscle size. All inflammatory markers were increased in heart failure patients ( P ≤ 0.05 to P < 0.01) compared to controls, with the exception of TNF-α. Despite no group differences in TNF-α, higher concentrations of this cytokine were correlated to lower skeletal muscle mass in the combined study population (range of r-values: − 0.436 to − 0.545; P < 0.05 to P < 0.02), as were IL-6 levels (range of r-values: − 0.438 to − 0.443; P < 0.05). TNF-α, sTNF-α RII, IL-6 and CRP showed strong negative relationships to aerobic capacity (range of r-values: − 0.579 to − 0.751; P < 0.01 to P < 0.001). In addition, elevated levels of IL-6 and TNF-α were associated with reduced leg and forearm skeletal muscle strength (range of r-values: − 0.440 to − 0.674; P < 0.05 to P < 0.01). Finally, correlations between cytokines and functional measures were present when heart failure patients were analyzed separately (range of r-values: − 0.646 to − 0.673; P < 0.05). Conclusions Our results suggest that circulating cytokines are related to both skeletal muscle mass and physical function. These findings provide further evidence to support the hypothesis that immune activation contributes to skeletal muscle atrophy and reduced functional capacity in heart failure patients.

A new theoretical model for predicting limit strains in the punch stretching of sheet metals

An initial non-uniformity in thickness of a sheet metal, which is commonly assumed as a basis for the theoretical prediction of limit strains in the biaxial stretching process, is considered here as a feature of the mathematical idealization of a complex process, rather than as a material imperfection existing in a real sheet metal. The present concept permits the degree of initial inhomogeneity to vary with the stress ratio, as well as with the mechanical properties of the material. When such a variation is allowed for in a suitable manner, the predicted forming limit curves exhibit a relatively small dependence on the degree of normal anisotropy of the sheet metal, and follow a trend that is in agreement with what is observed experimentally. The results demonstrate the importance of the non-quadratic yield function when dealing with sheet metals with a range of R-values of less than unity.

Correlation between serum cytokeratin 19 fragment and tissue polypeptide antigen levels in patients with non-malignant diseases

It has been reported that cytokeratin 19 fragment (CYFRA 21-1) is superior to tissue polypeptide antigen (TPA) as a tumor marker, although there is a high correlation between CYFRA 21-1 and TPA levels in patients with lung cancer. We investigated correlations between these tumor markers in patients with non-malignant diseases. Marked correlations were found between CYFRA 21-1 and TPA levels in healthy subjects ( n=31), non-insulin-dependent diabetes mellitus ( n=160) and hemodialysis patients ( n=83) (range of r-value=0.90–0.93, P<0.0001). However in liver cirrhosis patients ( n=36), only a weak correlation was found ( r=0.39, P<0.0001) and there were correlations between only TPA and both aspartate aminotransferase and alanine aminotransferase levels ( r 2=0.48 and 0.36, P<0.0001). The elevated TPA levels in liver cirrhosis patients may be related to the decreased specificity of TPA as a tumor marker.

Correlation between serum cytokeratin 19 fragment and tissue polypeptide antigen levels in patients with non-small cell lung cancer

We evaluated the correlation between serum cytokeratin 19 fragment (CYFRA 21-1) and tissue polypeptide antigen (TPA) levels in 57 non-small cell lung cancer patients. There was a significant correlation between serum CYFRA 21-1 and TPA levels for each clinical stage and TNM (T, primary tumor; N, regional lymph node involvement; M, occurrence of distant metastasis) subcategory (range of r-value=0.809–0.998, P<0.01). High correlations between serum CYFRA 21-1 and TPA levels were found in eight patients both before and after the surgery, in 22 patients before and after chemotherapy and in another 27 patients who could not complete the scheduled chemotherapy (range of r-value=0.856–0.998, P<0.0001). However the positive rate of CYFRA 21-1 was higher than that of TPA (61% vs. 53%, P<0.05). CYFRA 21-1 would yield better diagnostic results for non-small cell lung cancers than TPA, though these tumor markers are both cytokeratin-associated tumor markers.

Absolute and convective instabilities of plane turbulent wakes in a shallow water layer

In shallow turbulent wake flows (typically an island wake), the flow patterns have been found experimentally to depend mainly on a shallow wake parameter, S=cfD/h in which cf is a quadratic-law friction coefficient, D is the island diameter and h is water depth. In order to understand the dependence of flow patterns on S, the shallow-water stability equation (a modified Orr–Sommerfeld equation) has been derived from the depth-averaged equations of motion with terms which describe bottom friction. Absolute and convective instabilities have been investigated on the basis of wake velocity profiles with a velocity deficit parameter R. Numerical computations have been carried out for a range of R-values and a stability diagram with two dividing lines was obtained, one defining the boundary between absolute and convective instabilities Sca, and another defining the transition between convectively unstable and stable wake flow Scc. The experimental measurements (Chen &amp; Jirka 1995) of return velocities in shallow wakes were used to compute R-values and two critical values, SA=0.79 and SC=0.85, were obtained at the intersections with lines Sca and Scc. Through comparison with transition values observed experimentally for wakes with unsteady bubble (recirculation zone) and vortex shedding, SU and SV respectively, the sequence SC&gt;SA&gt; SU&gt;SV shows vortex shedding to be the end product of absolute instability. This is analogous to the sequence of critical Reynolds numbers for an unbounded wake of large spanwise extent. Experimental frequency characteristics compare well with theoretical results. The observed values of SU and SV for different flow patterns correspond to the velocity profile with R=−0.945, which is located at the end of the wake bubble, and it provides the dominant mode.

The estimation of blood loss during burns surgery

The estimations of blood loss and transfusion requirements during burns surgery are notoriously difficult. This clinical study investigated the effectiveness of estimates made by junior and senior burns surgeons and senior anaesthetists by comparing them with calculated blood losses. Regression analysis shows good correlation between these methods (r-value range 0.75–0.97), although ‘eye-balling’ the losses tends to underestimate the transfusion requirements (regression slope coefficients ranged between 0.56 and 0.87). In only five out of 46 procedures was there a need for late transfusion for an unacceptably low haemoglobin level (< 10g/dl). This provides further empirical evidence for the clinical value of each member of the team voicing an estimate of the loss at the end of the procedure. The mean blood loss for 1 per cent of burn excised or split skin donor site harvested was 117 ml in adult cases. Blood loss can also be expressed as a mean percentage of the patient's calculated total blood volume for each 1 per cent burn excised or autograft harvested, giving figures of 2.6 per cent for adults and 3.4 per cent for children. Gravimetric analysis of soiled swabs underestimates the blood loss by approximately 50 per cent

The running coupling from SU(3) potentials

From an accurate determination of the inter-quark potential, one can study the running coupling constant for a range of R-values and hence estimate the scale Λ MS . Detailed results are presented for SU(3) pure gauge theory from a study of a 36 4 lattice at β = 6.5.

The running coupling from SU (3) lattice gauge theory

From an accurate determination of the interquark potential, one can study the running coupling constant for a range of R-values and hence estimate the scale Λ MS . Detailed results are presented for SU (3) pure gauge theory.

The running coupling from lattice gauge theory

From an accurate determination of the interquark potential, one can study the running coupling constant for a range of R-values and hence estimate the scale Λ MS . Detailed results are presented for SU (2) pure gauge theory to illustrate the method.

Photosynthetic membranes. A model study of the influence of photoinitiated grafting and graft polymerization of 1,6-hexanediol diacrylate and 4-( N-ethyl, N-2-acryloxyethyl)amino-4′-nitro-azobenzene, as co-monomers, onto polypropylene ribbon, on permeation and diffusion coefficients of oxygen and nitrogen

Photoinitiated grafting and graft polymerization of 1,6-hexanediol diacrylate ( I) and 4-(N-ethyl,N-2-acryloxyethyl)amino-4′-nitro-azobenzene ( II) as co-monomers with a fixed molar ratio I: II equal to 10, in the presence of 1,2-diphenyl-2,2-dimethoxyethanone ( III) as photoinitiator with a ratio R of its molar concentration of 0.005-0.38 with respect to the sum of molar concentrations of I and II, were studied using a polypropylene ribbon as a model system of a macroporous substrate. By polychromatic irradiation at 45°C with energy inputs of 90 mW cm −2, ultrathin layers of co-polymer, able to function as asymmetric membranes, could thus be obtained. Mean polychromatic quantum yields of grafting and graft polymerization, as a function of R, were also measured. Membrane specimens with constant values of grafted (200±20) and graft polymerized (500±80) molecules of monomer units in co-polymer per unit apparent surface (Å 2) have been subjected to measurements of permeabilities (P) and diffusivities (D) at 25°C for oxygen and nitrogen, as a function of R. Results show that only an optimum R minimizes P and D, and a narrow range of R-values allows a normal membrane behaviour.

Calculation of the green's function for the micromagnetic thin film problem

The spatial dependence of the Green's function of the micromagnetic thin film problem is calculated. Until now, such calculations have been undertaken only in limiting cases or by the help of approximations. Introducing contours of equal function values (coupling areas) we will discuss the behaviour of the Green's function, which depends crucially on a single constant q resulting from the magnetic and geometric film parameters. In the case of a typical polycrystalline or amorphous film with q ⪡ 1 (i.e. small anisotropy and large magnetization) the contours have a typical long extended shape over a wide range of r-values. This corresponds to Hoffmann's former linear ripple theory, which supplies a good description of the essential physical features just in this case. On the other hand, in the event of q ≈ 1 or q ⪢ 1 (i.e., for very thin films with a small magnetization M s and a large anisotropy) the shape of the coupling areas shows a much stronger dependence on the distance r . This should considerably influence the magnetic properties of such films, e.g., the magnetic ripple spectrum.

Demography of the twospotted spider mite, Tetranychus urticae Koch.

A simple life table model was constructed for Tetranychus urticae in which daily survivorship of eggs and motil stages, fecundity, and development time was altered to assess the impact of each parameter on the intrinsic rate of increase. r. Interpretation of the trade-offs focused on management considerations.A second aspect of the study concerned age and stage structure in mite populations including the time path of convergence to a stable age distribution and the effect of changes in birth and death rates on the age profile. The stable stage distributions of 7 tetranychid mite species were computed using 25 separate life tables. In spite of the wide range of r-values induced by different experimental conditions, all of the stage distributions were quite similar averaging roughly 66% eggs, 26% immatures, and 8% adults. Several population studies were cited which reported stage distributions of growing mite populations. The empirical evidence suggested that natural mite populations are often quite near this stable distribution.A practical problem involving the extent to which hormoligosis (insecticide stimulation) affects mite population growth rate was addressed using the life table model and laboratory data from controlled studies. The findings suggested that mite populations treated with insecticide may attain a 1.4- to a 4.2-fold difference in population size relative to an untreated population after 2 generations and over a 1,300-fold potential difference after 10 generations.

Location of the ethidium binding sites of high affinity in chromatin

The influence of H1 and H5 histones proteins upon the accessibility of ethidium bromide into chromatin is studied by steady-state fluorescence anisotropy in the range of r-values ([Dye]/[Phosphate]) smaller than 0.01. This corresponds to the very strong binding process. When H1 and H5 are present, the DNA segment which contains the binding sites is 25-30 base pairs long, even if H1 and H5 are digested by trypsin or by natural proteolysis, but presumably still interacting with the DNA chromatin. On the contrary, when H1 or H5 are separated from chromatin by an increase of the ionic strength, ethidium binds to a segment of DNA about 55-60 base pairs long. We may explain the results by assuming that the ethidium sites are located on a continuous segment constituting about one half of the linker, the other half interacting with H1 and H5. When chromatin is depleted from these proteins, the high affinity sites are distributed all along the linker.