A newly developed computer code GRASP to calculate some gamma ray shielding parameters has been introduced. Mass attenuation coefficients, effective atomic numbers, half-value layers and mean free ...paths of TeO2-B2O3-SiO2 glasses with different amounts of Bi2O3 have been studied in detail for photon energies between 10 and 150 keV. The mass attenuation coefficients determined with GRASP are in good agreement with the ones calculated with XCOM. GRASP can be used to determine various shielding parameters as an alternative to the existing programs. All the parameters calculated with GRASP suggest that gamma shielding capability of the glasses studied gets better as the amount of Bi2O3 in the glass increases.
•New program, GRASP, to calculate important gamma shielding parameters is introduced.•GRASP can calculate the shielding parameters at photon absorption edges.•Photon shielding ability of the glass increases as the bismuth content increases.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The mass attenuation coefficients (MAC), half–value layers (HVL) and effective atomic numbers (Zeff) of the quaternary tellurite glass system in the form of 75TeO2–15ZnO–(10-x)Nb2O5–xGd2O3, with x= ...0.5, 1.0, 1.5, 2.0 and 2.5 mol%, have been investigated at four average medical diagnostic energies (20, 30, 40 and 60 keV) using the chemical compositions and densities reported in various works by other reserachers. The mass attenuation coefficients have been obtained using the FLUKA Monte Carlo code and the results have been shown to be very consistent (with a percentage difference below 1 %) with the values in the XCOM database. Study of the HVL and Zeff have indicated that when the contribution of Gd2O3 in the glass is increased, the HVL decreases and the Zeff increases. Results of the mass attenuation coefficients for the glass samples at 40 and 60 keV have been compared with the ones for commonly used shielding material lead. It has been concluded that at 40 keV, the MAC are comparable with the value for lead. Furthermore, at 60 keV, three of the glass samples with the highest contribution of Gd2O3 have even larger mass attenuation coefficients than that of lead at the same energy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Red cell distribution width (RDW) is strongly associated with prognosis in cardiopulmonary disorders such as coronary artery disease, acute myocardial infarction, acute and chronic heart failure, and ...pulmonary hypertension. However, its prognostic significance in acute pulmonary embolism (PE) is unknown. The aim of this study was to investigate the relation between admission RDW and early mortality in patients with acute PE. One hundred sixty-five patients with confirmed acute PE were included. Patients with previous treatment for anemia, malignancy, or chronic liver disease, those with dialysis treatment for chronic renal failure, and those who received erythrocyte suspension for any reason were excluded. A total of 136 consecutive patients with acute PE were evaluated prospectively. According to receiver-operating characteristic curve analysis, the optimal cut-off value of RDW to predict early mortality was >14.6%, with 95.2% sensitivity and 53% specificity. Patients were categorized prospectively as having unchanged (group 1) or increased (group 2) RDW on the basis of a cut-off value of 14.6%. The mean age of patients was 63 ± 15 years. The mean follow-up duration was 11 ± 7 days, and 21 patients died. Among these 21 patients, 1 (1.6%) was in group 1 and 20 (27%) were in group 2 (p <0.001). Increased RDW >14.6% on admission, age, presence of shock, heart rate, oxygen saturation, and creatinine level were found to have prognostic significance in univariate Cox proportional-hazards analysis. Only increased RDW >14.6% on admission (hazard ratio 15.465, p = 0.012) and the presence of shock (hazard ratio 9.354, p <0.001) remained associated with increased risk for acute PE-related early mortality in a multivariate Cox proportional-hazards model. In conclusion, high RDW was associated with worse hemodynamic parameters, and RDW seems to aid in the risk stratification of patients with acute PE.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract Background Increased γ -glutamyl transferase (GGT) level is associated with increased oxidative stress, all-cause mortality, the development of cardiovascular disease, and metabolic ...syndrome. However, its role in acute pulmonary embolism (PE) is unknown. In this study, we aimed to investigate the relationship between GGT and early mortality in patients with acute PE. Methods A total of 127 consecutive patients with confirmed PE were evaluated. The optimal cutoff value of GGT to predict early mortality was measured as more than 55 IU/L with 94.4% sensitivity and 66.1% specificity. Patients with acute PE were categorized prospectively as having no increased (group I) or increased (group II) GGT based on a cutoff value. Results Of these 127 patients, 18 patients (14.2%) died during follow-up. Among these 18 patients, 1 (1.4%) patient was in group I, and 17 (30.9%) patients were in group II ( P < .001). γ -Glutamyl transferase level on admission, presence of shock, heart rate, oxygen saturation, right ventricular dilatation/hypokinesia, main pulmonary artery involvement, troponin I, alanine aminotransferase, alkaline phosphatase, and creatinine levels were found to have prognostic significance in univariate analysis. In the multivariate Cox proportional hazards model, GGT level on admission (hazard ratio HR, 1.015; P = .017), presence of shock (HR, 15.124; P = .005), age (HR, 1.107; P = .010), and heart rate (HR, 1.101; P = .032) remained associated with an increased risk of acute PE-related early mortality after the adjustment of other potential confounders. Conclusions We have shown that a high GGT level is associated with worse hemodynamic parameters, and it seems that GGT helps risk stratification in patients with acute PE.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The ratios of inclusive electron scattering cross sections of {sup 4}He, {sup 12}C, and {sup 56}Fe to {sup 3}He have been measured at 1<x{sub B}<3. At Q{sup 2}>1.4 GeV{sup 2}, the ratios exhibit two ...separate plateaus, at 1.5<x{sub B}<2 and at x{sub B}>2.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A=3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A=4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
We report a new measurement of the exclusive electroproduction reaction gamma* p -> pi0 p to explore the evolution from soft non-perturbative physics to hard processes via the Q2 dependence of the ...magnetic (M1+), electric (E1+) and scalar (S1+) multipoles in the N to Delta transition. 9000 differential cross section data points cover W from threshold to 1.4 eV/c2, 4pi center-of-mass solid angle, and Q2 from 3 to 6 GeV2/c2, the highest yet achieved. It is found that the magnetic form factor G*M decreases with Q2 more steeply than the proton magnetic form factor, the ratio E1+/M1+ is small and negative, indicating strong helicity non-conservation, and the ratio S1+/M1+ is negative, while its magnitude increases with Q2.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
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