974 resultados para IEC 2-3-A method
Resumo:
Viable cells of Candida guilliermondii were immobilized by inclusion into polyvinyl alcohol (PVA) hydrogel using the freezing-thawing method. Entrapment experiments were planned according to a 2(3) full factorial design, using the PVA concentration (80, 100, and 120 g L(-1)), the freezing temperature (-10, -15, and -20 degrees C), and the number of freezing-thawing cycles (one, three, and five) as the independent variables, integrated with three additional tests to estimate the errors. The effectiveness of the immobilization procedure was checked in Erlenmeyer flasks as the pellet capability to catalyze the xylose-to-xylitol bioconversion of a medium based on sugarcane bagasse hemicellulosic hydrolysate. To this purpose, the yield of xylitol on consumed xylose, xylitol volumetric productivity, and cell retention yield were selected as the response variables. Cell pellets were then used to perform the same bioconversion in a stirred tank reactor operated at 400 rpm, 30 degrees C, and 1.04 vvm air flowrate. At the end of fermentation, a maximum xylitol concentration of 28.7 g L(-1), a xylitol yield on consumed xylose of 0.49 g g(-1) and a xylitol volumetric productivity of 0.24 g L(-1) h(-1) were obtained.
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This work reports on the bimolecular sensitization of nitric oxide release from cis-[Ru(bpy)(2)(iso)-NO](PF(6))(3) (1) (iso = isoquinoline and bpy = 2,2`- bipyridine) by irradiating the MLCT transition of the chloro analog cis-[Ru(bpy) 2(iso) Cl] PF6 (2). The compounds displayed peaks in the ESI-MS spectra at m/z 749.1 and m/z 578.1 ascribed, respectively, to ([1(NO(o))-2PF(6)center dot CH(3)OH](2+)) and ([2-PF(6)](+)). In the cyclic voltammograms, the nitrosyl complex presented two redox waves related to the NO ligand at 0.48 and -0.37 V (versus Ag/AgCl, NO(+/0/-1) processes), while the sensitizer showed two reversible waves at 0.79 and -1.46 V (versus Ag/AgCl, Ru(2+/3+) and bpy(0/-1), respectively). The most important feature of this system is that the nitrosyl compound does not have significant absorption in the visible region, while the sensitizer has an intense band centered at 496 nm. The irradiation of an equimolar mixture of the two compounds in an ethanol: water solution (v: v) with light of lambda > 500 nm leads to NO release, as probed by amperometric measurements. The variational method was applied, showing that the two compounds self-assembly in solution with a 1: 1 stoichiometry. Fluorescence spectra acquired at 77 K provided the E(0-0) for the system and, from the thermodynamic cycle it was estimated that the photoinduced electron transfer between the species has a Delta G value of -1.59 eV. (C) 2011 Elsevier B. V. All rights reserved.
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A CE method was developed and validated for the stereoselective determination of midodrine and desglymidodrine in Czapek culture medium to be applied to a stereoselective biotransformation study employing endophytic fungi. The electrophoretic analyses were performed using an uncoated fused-silica capillary and 70 mmol/L sodium acetate buffer solution (pH 5.0) containing 30 mmol/L heptakis (2, 3, 6-tri-O-methyl)-beta-CD as running electrolyte. The applied voltage and temperature used were 15 kV and 15 C, respectively. The UV detector was set at 200 nm. The sample preparation was carried out by liquid-liquid extraction using ethyl acetate as extractor solvent. The method was linear over the concentration range of 0.1-12 mu g/mL for each enantiomer of midodrine and desglymidodrine (r >= 0.9975). Within-day and between-day precision and accuracy evaluated by RSDs and relative errors, respectively, were lower than 15% for all analytes. The method proved to be robust by a fractional factorial design evaluation. The validated method was used to assess the midodrine biotransformation to desglymidodrine by the fungus Phomopsis sp. (TD2), which biotransformed 1.1% of (-)-midodrine to (-)-desglymidodrine and 6.1% of (+)-midodrine to (+)-desglymidodrine.
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A graphite furnace atomic absorption spectrometric method is proposed for the direct and simultaneous determination of Cd, Cu, and Se in human blood. Samples were diluted 1:10 (v/v) in 0.5% (v/v) HNO(3) + 0.5% (v/v) Triton X-100 solution. For 12 mu L injected sample volume + 5 mu L, of 1000 mg L(-1) Pd(NO(3))(2) + 3 mu L of 1000 mg L(-1) Mg(NO(3))(2), the calculated characteristic masses (mo) were 0.9 pg Cd, 16 pg Cu, and 39 pg Se, which are close to those mo values for single-element conditions for THGA furnace (1.3 pg Cd, 17 pg Cu, and 45 pg Se). Calibration curves with linear correlations better than 0.999 were obtained. The limits of detection (LOD) were 0.03 mu g L(-1) Cd, 0.075 mu g L(-1) Cu and 0.3 mu g L(-1) Se, and the relative standard deviations (n= 12) were 2.5%, 0.3%, and 1.5%, respectively. The method was applied for Cd, Cu, and Se determination in 10 human blood samples and the results were in agreement at the 95% confidence level with those obtained by inductively coupled plasma mass spectrometry. Concentrations of analytes in the selected blood samples varied from 1.7 to 3.2 mu g L(-1) Cd, 700 to 921.7 mu g L(-1) Cu, and from 68.6 to 350 mu g L(-1) Se. The accuracy of the proposed method was also evaluated by an addition-recovery experiment and recoveries of Cd, Cu, and Se added to blood samples ranged from 99-109%, 91-103%,and 93-103%, respectively.
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The efficient palladium-catalyzed Suzuki-Miyaura cross-coupling reaction of (2S)-isopropyl-5-iodo-2,3-dihydro-4(H)-pyrimidin-4-one with, arylethynyl-, heteroarylethynyl-, and alkylethynyltrifluoroborate salts is reported. The standard protocol was evaluated and optimized in order to gain access to suitable precursors of enantiopure 2-substituted beta-amino acids. The scope and limitations of this methodology are discussed. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
This paper presents the recent finding by Muhlhaus et al [1] that bifurcation of crack growth patterns exists for arrays of two-dimensional cracks. This bifurcation is a result of the nonlinear effect due to crack interaction, which is, in the present analysis, approximated by the dipole asymptotic or pseudo-traction method. The nonlinear parameter for the problem is the crack length/ spacing ratio lambda = a/h. For parallel and edge crack arrays under far field tension, uniform crack growth patterns (all cracks having same size) yield to nonuniform crack growth patterns (i.e. bifurcation) if lambda is larger than a critical value lambda(cr) (note that such bifurcation is not found for collinear crack arrays). For parallel and edge crack arrays respectively, the value of lambda(cr) decreases monotonically from (2/9)(1/2) and (2/15.096)(1/2) for arrays of 2 cracks, to (2/3)(1/2)/pi and (2/5.032)(1/2)/pi for infinite arrays of cracks. The critical parameter lambda(cr) is calculated numerically for arrays of up to 100 cracks, whilst discrete Fourier transform is used to obtain the exact solution of lambda(cr) for infinite crack arrays. For geomaterials, bifurcation can also occurs when array of sliding cracks are under compression.
Resumo:
1 We have recently suggested the existence in the heart of a 'putative beta(4)-adrenoceptor' based on the cardiostimulant effects of non-conventional partial agonists, compounds that cause cardiostimulant effects at greater concentrations than those required to block beta(1)- and Bz-adrenoceptors. We sought to obtain further evidence by establishing and validating a radioligand binding assay for this receptor with (-)-[H-3]-CGP 12177A ((-)-4-(3-tertiarybutylamino-2-hydroxypropoxy) benzimidazol-2-one) in rat atrium. We investigated (-)-[H-3]-CGP 12177A for this purpose for two reasons, because it is a nonconventional partial agonist and also because it is a hydrophilic radioligand. 2 Increasing concentrations of(-)-[H-3]-CGP 12177A, in the absence or presence of 20 mu M (-)-CGP 12177A to define non-specific binding, resulted in a biphasic saturation isotherm. Low concentrations bound to beta(1)- and beta(2)-adrenoceptors (pK(D) 9.4+/-0.1, B-max 26.9+/-3.1 fmol mg(-1) protein) and higher concentrations bound to the 'putative beta(4)-adrenoceptor' (pK(D) 7.5+/-0.1, B-max 47.7+/-4.9 fmol mg(-1) protein). In other experiments designed to exclude beta(1)- and beta(2)-adrenoceptors, (-)-[H-3]-CGP 12177A (1-200 nM) binding in the presence of 500 nM (-)-propranolol was also saturable (pK(D) 7.6+/-0.1, B-max 50.8+/-7.4 fmol mg(-1) protein). 3 The non-conventional partial agonists (-)-CGP 12177A (pK(i) 7.3+/-0.2), (+/-)-cyanopindolol (pK(i) 7.6+/-0.2), (-)-pindolol (pK(i) 6.6+/-0.1) and (+)-carazolol (pk(i), 7.2+/-0.2) and the antagonist (-)-bupranolol (pK(i) 6.6+/-0.2), all competed for (-)-[H-3]-CGP 12177A binding in the presence of 500 nM (-)-propranolol at the 'putative beta(4)-adrenoceptor', with affinities closely similar to potencies and affinities determined in organ bath studies. 4 The catecholamines competed with (-)-[H-3]-CGP 12177A at the 'putative beta(4)-adrenoceptor' in a stereoselective manner, (-)-noradrenaline (pK(iH) 6.3 +/- 0.3, pK(i), 3.5 +/- 0.1), (-)-adrenaline (pK(iH) 6.5 +/- 0.2, pK(iL) 2.9 +/- 0.1), (-)-isoprenaline (pK(iH) 6.2 +/- 0.5, pK(iL) 3.3 +/- 0.1), (+)-isoprenaline (pK(i) < 1.7), (-)-R0363 ((-)-(1-(3,4-dimethoxyphenethylamino)-3-(3,4-dihydroxyphenoxy)-2-propranol)oxalate, pK(i) 5.5 +/- 0.1). 5 The inclusion of guanosine 5-triphosphate (GTP 0.1 mM) had no effect on binding of (-)-CGP 12177A or (-)-isoprenaline to the 'putative beta(4)-adrenoceptor'. In competition binding studies, (-)-CGP 12177A competed with (-)-[H-3]-CGP 12177A for one receptor state in the absence (pK(i) 7.3 +/- 0.2) or presence of GTP (pK(i) 7.3 +/- 0.2). (-)-Isoprenaline competed with (-)-[H-3]-CGP 12177A for two states in the absence (pK(iH) 6.6 +/- 0.3, pK(iL) 3.5 +/- 0.1; % H 25 +/- 7) or presence of GTP (pK(iH) 6.2 +/- 0.5, pK(iL) 3.4 +/- 0.1; % H 37 +/- 6). In contrast, at beta(1)-adrenoceptors, GTP stabilized the low affinity state of the receptor for (-)-isoprenaline. 6 The specificity of binding to the 'putative beta(4)-adrenoceptor' was tested with compounds active at other receptors. High concentrations of the beta(4)-adrenoceptor agonists, BRL 37344 ((RR + SS)[4-[2-[[2-(3-chlorophenyl)-2-hydroxy -ethyl]amino]propyl]phenoxy]acetic acid, 6 mu M), SR 58611A (ethyl((7S)-7-[(2R)-2-(3-chlorophenyl)-2-hydroxyethylamino]-5,6,7,8-tetrahydronaphtyl-2-yloxy) acetate hydrochloride, 6 mu M), ZD 2079 ((+/-)-1-phenyl-2-(2-4-carboxymethylphenoxy)-ethylamino)ethan-1-ol, 60 mu M), CL 316243 (disodium (R,R)-5-[2-[2-(3-chlorophenyl)-2-hydroxyethyl-amino]propyl]- 1,3-benzodioxole-2,2-dicarboxylate, 60 mu M) and antagonist SR 59230A (3-(2-ethylphenoxy)-1-[(1S)-1,2,3,4-tetrahydronaphth-1-ylamino]-2S-2-propanol oxalate, 6 mu M) caused less than 22% inhibition of (-)-[H-3]-CGP 12177A binding in the presence of 500 nM (-)-propranolol. Histamine (1 mM), atropine (1 mu M), phentolamine (10 mu M), 5-HT(100 mu M) and the 5-HT4 receptor antagonist SE 207710 ((1-butyl-4-piperidinyl)-methyl 8-amino-7-iodo-1 ,4-benzodioxan-5-carboxylate, 10 nM) caused less than 26% inhibition of binding. 7 Non-conventional partial agonists, the antagonist (-)-bupranolol and catecholamines all competed for (-)-[H-3]-CGP 12177A binding in the absence of (-)-propranolol at beta(1)-adrenoceptors, with affinities (pK(i)) ranging from 1.6-3.6 log orders greater than at the 'putative beta(4)-adrenoceptor'. 8 We have established and validated a radioligand binding assay in rat atrium for the 'putative beta(4)-adrenoceptor' which is distinct from beta(1)-, beta(2)- and beta(3)-adrenoceptors. The stereoselective interaction with the catecholamines provides further support for the classification of the receptor as 'putative beta(4)-adrenoceptor'.
Resumo:
Four adducts of triphenylphosphine oxide with aromatic carboxylic acids have been synthesized and tested for second-order non-linear optical properties. These were with N-methylpyrrole-2-carboxylic acid (I), indole-2-carboxylic acid (2), 3-dimethylaminobenzoic acid (3), and thiophen-2-carboxylic acid (4). Compound (1) produced clear, colourless crystals (space group P2(1)2(1)2(1) With a 9.892(1), b 14.033(1), c 15.305(1) Angstrom, Z 4) which allowed the structure to be determined by X-ray diffraction.
Resumo:
The complexes [Fe([9]aneN(2)S)(2)][ClO4](2), [Fe([9]aneN(2)S)(2)][ClO4](3) and [Fe([9]aneNS(2))(2)][ClO4](2) ([9]aneN(2)S = 1-thia-4. 7-diazacyclononane and [9]aneNS(2) = 1,4-dithia-7-azacyclononane) have been prepared and the latter two characterised by X-ray crystallography. The Mossbauer spectra (isomer shift/mm s(-1), quadrupole splitting/mm s(-1), 4.2 K) for [Fe([9]aneN(2)S)(2)][ClO4](2) (0.52, 0.57), [Fe([9]aneN(2)S)(2)][ClO4](3) (0.25, 2.72) and [Fe([9]aneNS(2))(2)][ClO4](2) (0.43, 0.28) are typical for iron(II) and iron(III) complexes. Variable-temperature susceptibility measurements for [Fe([9]aneN(2)S)(2)][ClO4](2) (2-300 K) revealed temperature-dependent behaviour in both the solid state [2.95 mu(B) (300 K)-0.5 mu(B) (4.2 K)] and solution (Delta H degrees 20-22 kJ mol(-1), Delta S degrees 53-60 J mol(-1) K-1). For [Fe([9]aneN(2)S)(2)][ClO4](3) in the solid state [2.3 mu(B) (300 K)-1.9 mu(B) (4.2 K)] the magnetic data were fit to a simple model (H = -lambda L . S + mu L-z) to give the spin-orbit coupling constant (lambda) of -260 +/- 10 cm(-1). The solid-state X-band EPR spectrum of [Fe([9]aneN(2)S)(2)][ClO4](3) revealed axial symmetry (g(perpendicular to) = 2.607, g(parallel to) = 1.599). Resolution of g(perpendicular to) into two components at Q-band frequencies indicated a rhombic distortion. The low-temperature single-crystal absorption spectra of [Fe([9]aneN(2)S)(2)][ClO4](2) and [Fe([9]aneNS(2))(2)][ClO4](2) exhibited additional bands which resembled pseudotetragonal low-symmetry splitting of the parent octahedral (1)A(1g) --> T-1(2g) and (1)A(1g) ---> T-1(1g) transitions. However, the magnitude of these splittings was too large, requiring 10Dq for the thioether donors to be significantly larger than for the amine donors. Instead, these bands were tentatively assigned to weak, low-energy S --> Fe-II charge-transfer transitions. Above 200 K, thermal occupation of the high-spin T-5(2g) ground state resulted in observation of the T-5(2g) --> E-5(g) transition in the crystal spectrum of [Fe([9]aneN(2)S)(2)][ClO4](2). From a temperature-dependence study, the separation of the low-spin (1)A(1g) and high-spin T-5(2g) ground states was approximately 1700 cm(-1). The spectrum of the iron(III) complex [Fe([9]aneN(2)S)(2)][ClO4](3) is consistent with a low-spin d(5) configuration.
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The properties of the hydrogen-bonded polymer blends of poly(4-vinylphenol) and poly(2-ethoxyethyl methacrylate) are presented. Spectroscopic techniques such as C-13 solid-state NMR and FT-IR are used to probe specific interactions of the blends at various compositions. Spectral features from both techniques revealed that site-specific interactions are present, consistent with a significant degree of mixing of the blend components. Changes in chemical shift and line shape of the phenolic carbon and carbonyl resonances in the C-13 CPMAS spectra of the blends as a function of composition are interpreted as resulting from changes in the relative intensities of two closely overlapped signals. A quantitative measure of hydrogen-bonded carbonyl groups using C-13 NMR has been obtained which agreed well with the results from FT-IR analyses. It is also shown that C-13 NMR can be used to measure the fraction of hydroxyl groups associated with carbonyl groups, which was not possible previously using FT-IR due to extensive overlapping of bands in the hydroxyl stretching region. The results of measurements of H-1 T-1 and 1H T-1 rho indicate that PVPh and PEEMA are intimately mixed on a scale less than 2-3 nm.
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Dual-energy X-ray absorptiometry (DXA) is a widely used method for measuring bone mineral in the growing skeleton. Because scan analysis in children offers a number of challenges, we compared DXA results using six analysis methods at the total proximal femur (PF) and five methods at the femoral neck (FN), In total we assessed 50 scans (25 boys, 25 girls) from two separate studies for cross-sectional differences in bone area, bone mineral content (BMC), and areal bone mineral density (aBMD) and for percentage change over the short term (8 months) and long term (7 years). At the proximal femur for the short-term longitudinal analysis, there was an approximate 3.5% greater change in bone area and BMC when the global region of interest (ROI) was allowed to increase in size between years as compared with when the global ROI was held constant. Trend analysis showed a significant (p < 0.05) difference between scan analysis methods for bone area and BMC across 7 years. At the femoral neck, cross-sectional analysis using a narrower (from default) ROI, without change in location, resulted in a 12.9 and 12.6% smaller bone area and BMC, respectively (both p < 0.001), Changes in FN area and BMC over 8 months were significantly greater (2.3 %, p < 0.05) using a narrower FN rather than the default ROI, Similarly, the 7-year longitudinal data revealed that differences between scan analysis methods were greatest when the narrower FN ROI was maintained across all years (p < 0.001), For aBMD there were no significant differences in group means between analysis methods at either the PF or FN, Our findings show the need to standardize the analysis of proximal femur DXA scans in growing children.
Resumo:
1 The smooth muscle relaxant responses to the mixed beta(3)-, putative beta(4)-adrenoceptor agonist, (-)-CGP 12177 in rat colon are partially resistant to blockade by the beta(3)-adrenoceptor antagonist SR59230A suggesting involvement of beta(3)- and putative beta(4)-adrenoceptors. We now investigated the function of the putative beta(4)-adrenoceptor and other beta-adrenoceptor subtypes in the colon, oesophagus and ureter of wild-type (WT) and beta(3)-adrenoceptor knockout (beta(3)KO) mice. 2 (-)-Noradrenaline and (-)-adrenaline relaxed KCl (30 mM)-precontracted colon mostly through beta(1)-and beta(3)-adrenoceptors to a similar extent and to a minor extent through beta(2)-adrenoceptors. In colon from beta(3)KO mice, (-)-noradrenaline was as potent as in WT mice but the effects were mediated entirely through beta(1)-adrenoceptors. (-)-CGP 12177 relaxed colon from beta(3)KO mice with 2 fold greater potency than in WT mice. The maintenance of potency for (-)-noradrenaline and increase for (-)-CGP 12177 indicate compensatory increases in beta(1)- and putative beta(4)-adrenoceptor function in beta(3)KO mice. 3 In oesophagi precontracted with 1 mu M carbachol, (-)-noradrenaline caused relaxation mainly through beta(1)-and beta(3)-adrenoceptors. (-)-CGP 12177 (2 mu M) relaxed oesophagi from WT by 61.4+/-5.1% and beta(3)KO by 67.3+/-10.1% of the (-)-isoprenaline-evoked relaxation, consistent with mediation through putative beta(4)-adrenoceptors. 4 In ureter, (-)-CGP 12177 (2 mu M) reduced pacemaker activity by 31.1+/-2.3% in WT and 31.3+/-7.5% in beta(3)KO, consistent with mediation through putative beta(4)-adrenoceptors. 5 Relaxation of mouse colon and oesophagus by catecholamines are mediated through beta(1)- and beta(3)- adrenoceptors in WT. The putative beta(4)-adrenoceptor, which presumably is an atypical state of the beta(1)-adrenoceptor, mediates the effects of(-)-CGP 12177 in colon, oesophagus and ureter.
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OBJECTIVE: The goal of this study was to estimate the associations between outdoor air pollution and cardiovascular hospital admissions for the elderly. DESIGN: Associations were assessed using the case-crossover method for seven cities: Auckland and Christchurch, New Zealand; and Brisbane, Canberra, Melbourne, Perth, and Sydney Australia. Results were combined across cities using a random-effects meta-analysis and stratified for two adult age groups: 15-64 years and >= 65 years of age (elderly). Pollutants considered were nitrogen dioxide, carbon monoxide, daily measures of particulate matter (PM) and ozone. Where multiple pollutant associations were found, a matched case-control analysis was used to identify the most consistent association. RESULTS: In the elderly, all pollutants except 03 were significantly associated with five categories or cardiovascular disease admissions. No associations were found for arrhythmia and stroke. For a 0.9-ppm increase in CO, there were significant increases in elderly hospital admissions for total cardiovascular disease (2.2%), all cardiac disease (2.8%), cardiac failure (6.0%), ischemic heart disease (2.3%), and myocardial infarction (2.9%). There was some heterogeneity between cities, possibly due to differences in humidity and the percentage of elderly people. In matched analyses, CO had the most consistent association. CONCLUSIONS. The results suggest that air pollution arising from common emission sources for CO, NO2, and PM (e.g., motor vehicle exhausts) has significant associations with adult cardiovascular hospital admissions, especially in the elderly, at air pollution concentrations below normal health guidelines. RELEVANCE TO CLINICAL AND PROFESSIONAL PRACTICE: Elderly populations in Australia need to be protected from air pollution arising from outdoor sources to reduce cardiovascular disease.
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Previous studies have reported differences in presenting symptoms and angiographic characteristics between women and men undergoing evaluation for suspected coronary artery disease (CAD). We examined the relation between symptoms and extent of CAD in patients with type 2 diabetes mellitus and known CAD enrolled in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial. Of 1,775 patients (533 women, 30%, and 1,242 men, 70%), women were more likely than men to have angina (65% vs 56%, p < 0.001) or an atypical angina/anginal equivalent (71% vs 58%, p < 0.001). More women reported unstable angina (17% vs 13%, p = 0.047) or were in a higher Canadian Cardiology Society class compared to men (Canadian Cardiology Society classes II to IV 78% vs 68%, p = 0.002). Fewer women than men had no symptoms (14% vs 22%, p < 0.001). Women had a lower mean myocardial jeopardy index (42.5 +/- 24.3 vs 47.9 +/- 24.3, p < 0.001), smaller number of total significant lesions (2.3 +/- 17 1.7 vs 2.7 +/- 1.8, p < 0.001), and fewer jeopardized left ventricular regions (p < 0.001 for distribution) or long-term occlusions (29% vs 42%, p < 0.001). After adjustment for relevant covariates, the odds of having CAD symptoms were still higher in women than men (odds ratio for angina 1.31, 95% confidence interval 1.02 to 1.69; odds ratio for atypical angina 1.52, 95% confidence interval 1.17 to 1.96). In conclusion, in a high-risk group of patients with known CAD and diabetes mellitus, women were more symptomatic than men but had less obstructive CAD. These data suggest that factors other than epicardial CAD severity influence symptom presentation in women in this population. (C) 2011 Elsevier Inc. All rights reserved. (Am J Cardiol 2011;107:980-985)
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Clinical applications of quantitative computed tomography (qCT) in patients with pulmonary opacifications are hindered by the radiation exposure and by the arduous manual image processing. We hypothesized that extrapolation from only ten thoracic CT sections will provide reliable information on the aeration of the entire lung. CTs of 72 patients with normal and 85 patients with opacified lungs were studied retrospectively. Volumes and masses of the lung and its differently aerated compartments were obtained from all CT sections. Then only the most cranial and caudal sections and a further eight evenly spaced sections between them were selected. The results from these ten sections were extrapolated to the entire lung. The agreement between both methods was assessed with Bland-Altman plots. Median (range) total lung volume and mass were 3,738 (1,311-6,768) ml and 957 (545-3,019) g, the corresponding bias (limits of agreement) were 26 (-42 to 95) ml and 8 (-21 to 38) g, respectively. The median volumes (range) of differently aerated compartments (percentage of total lung volume) were 1 (0-54)% for the nonaerated, 5 (1-44)% for the poorly aerated, 85 (28-98)% for the normally aerated, and 4 (0-48)% for the hyperaerated subvolume. The agreement between the extrapolated results and those from all CT sections was excellent. All bias values were below 1% of the total lung volume or mass, the limits of agreement never exceeded +/- 2%. The extrapolation method can reduce radiation exposure and shorten the time required for qCT analysis of lung aeration.