431 research outputs found
Time trends in the epidemiology of renal transplant patients with type 1 diabetes mellitus over the last four decades
Background. Diabetes mellitus (DM) type 1 is an important contributor to end-stage renal disease (ESRD) among younger transplant recipients. However, little is known about the changes in epidemiological characteristics of this population. Especially, time to reach ESRD may have changed in type 1 diabetic patients referred for transplantation, resulting in higher age at time of grafting. Such time trends may allow anticipating future developments regarding the demand for organ replacement in this patient group. Methods. We retrospectively analysed 173 patients with type 1 DM undergoing renal transplantation at our institution, stratified into four groups according to year of reaching ESRD (A = 1973-1983, B = 1984-1990, C = 1991-1995 and D = 1996-2002). For each group we determined age at diagnosis of DM, age at time of reaching ESRD and age at time of transplantation. From these data, the interval from diagnosis of DM to ESRD and from ESRD to transplantation was calculated. The results were analysed in relation to gender, year of and age at onset of diabetes. Results. Patients reaching ESRD in more recent years (group D) tended to be both younger at diagnosis of DM and older when reaching ESRD, resulting in higher mean age at transplantation (35.0, 37.5, 39.6 and 41.0 years in groups A, B, C and D, respectively). Accordingly, median duration to ESRD has significantly been prolonged over the last five decades in patients with type 1 DM undergoing renal transplantation (group A: 21.0, B: 20.7, C: 22.3 and D: 28.5 years; P<0.0001), this finding being more pronounced in female patients. Conclusions. The results of our analysis are compatible with a change in epidemiology in patients undergoing kidney transplantation. Older age at time of reaching ESRD may impact significantly on the demand for renal grafts, as patients are already clearly older nowadays when being transplanted. From our data it cannot be concluded whether this development is due to a change in the progression of diabetic nephropathy or may simply reflect a change in the selection of type 1 diabetic patients referred for transplantatio
Obesity related eating behaviour patterns in Swedish preschool children and association with age, gender, relative weight and parental weight - factorial validation of the Children's Eating Behaviour Questionnaire
<p>Abstract</p> <p>Background</p> <p>The Children's Eating Behaviour Questionnaire (CEBQ) is a multi-dimensional, parent-reported questionnaire measuring children's eating behaviours related to obesity risk, i.e. 'enjoyment of food', 'food responsiveness', 'slowness in eating' and 'satiety responsiveness'. It has not previously been validated in a Swedish population, neither on children under the age of 2 years. In the present study we examined the factor structure and the reliability of the Swedish version of the CEBQ, for use in an obesity intervention programme targeting preschool children 1-6 years. Further, the associations between eating behaviours and children's age, gender and relative weight (BMI SDS) and parental weight were investigated.</p> <p>Methods</p> <p>Parents to 174 children aged 1-6 years (50% girls, mean age 3.8 years), recruited from five kindergartens in Stockholm, completed the Swedish version of the CEBQ. Data on children's weight and height, parental weight, height and educational level was collected. Children's relative weight was calculated for a subpopulation (mean BMI SDS -0.4, n = 47). Factorial validation (Principal Component Analysis) on all CEBQ items was performed. Differences in eating behaviours by age, gender and parental weight were examined. Correlations between eating behaviours and the child's BMI SDS were analysed controlling for age, gender, parental weight and education in linear regression analyses.</p> <p>Results</p> <p>The factor analysis revealed a seven factor solution with good psychometric properties, similar to the original structure. The behaviour scales 'overeating'/'food responsiveness', 'enjoyment of food' and 'emotional undereating' decreased with age and 'food fussiness' increased with age. Eating behaviours did not differ between girls and boys. The children's relative weight was not related to any of the eating behaviours when controlling for age, gender, parental weight and education, and only associated with parental weight status.</p> <p>Conclusions</p> <p>Our results support the use of the CEBQ as a psychometric instrument for assessing children's eating behaviours in Swedish children aged 1-6 years. Measuring obesity related eating behaviours in longitudinal and interventional studies would offer opportunities for studying causal effects of eating behaviours in the development of obesity in children.</p
Eating behaviour patterns in Chinese children aged 12-18 months and association with relative weight - factorial validation of the Children's Eating Behaviour Questionnaire
<p>Abstract</p> <p>Background</p> <p>Eating behaviours have been suggested relating to obesity development. The Children's Eating Behaviour Questionnaire (CEBQ) is a parent-report measure constructed to assess multiple dimensions of eating behavior for children. This study aimed to test the validity of the Chinese version of Children's Eating Behaviour Questionnaire (CEBQ) in Chinese children aged 12-18 months. We examined factor structure and the reliability of the Chinese version of the CEBQ, the associations between children's eating behaviours and children's weight (BMI SDS) were assessed.</p> <p>Methods</p> <p>219 questionnaires were filled out by the caregivers, approached in community health care centers in two cities in China. BMI of each child was calculated and converted to BMI SDS. Factor validation (Principal Component Analysis, exploratory factor analysis) on all CEBQ items was performed and gender difference in eating behaviours was examined. Correlations between eating behaviours and the child's BMI SDS were analyzed by linear regression analysis controlling for gender, parental combined weight, and education.</p> <p>Results</p> <p>The factor analysis revealed a seven-factor solution, with factor 'food responsiveness' (FR) split into two. 'Satiety responsiveness' (SR) and 'Enjoyment of food' (EF) factors were not detected. Interestingly, boys scored higher than girls in the FR scales, whereas girls had a higher score in 'food fussiness' (FF) scale.</p> <p>Conclusions</p> <p>We conclude that although a valuable psychometric instrument, CEBQ might be affected by age and cultural differences. Therefore, adjusting it in order to fit the Chinese population was suggested. We did not find an association between eating behaviours and children's BMI SDS, when it was controlled for gender and parental weight.</p
Vacuum ultraviolet excitation luminescence spectroscopy of few-layered MoS 2
We report on vacuum ultraviolet (VUV) excited photoluminescence (PL) spectra emitted from a chemical vapor deposited MoS₂ few-layered film. The excitation spectrum was recorded by monitoring intensities of PL spectra at ~1.9 eV. A strong wide excitation band peaking at 7 eV was found in the excitation. The PL excitation band is most intensive at liquid helium temperature and completely quenched at 100 K. Through first-principles calculations of photoabsorption in MoS₂, the excitation was explicated and attributed to transitions of electrons from p- and d- type states in the valence band to the d- and p-type states in the conduction band. The obtained photon-in/photon-out results clarify the excitation and emission behavior of the low dimensional MoS₂ when interacting with the VUV light sources
Double K-shell photoionization and hypersatellite x-ray transitions of 12⩽Z⩽23 atoms
Single-photon double K-shell ionization of low-Z neutral atoms in the range 12⩽Z⩽23 is investigated. The experimental method was based on measurements of the high- resolution Kαh hypersatellite x-ray spectra following the radiative decay of the K-shell double-vacancy states excited by monochromatic synchrotron radiation. The photon energy dependence of the double K-shell ionization was measured over a wide range of photon energies from threshold up to and beyond the maximum of the double-to- single photoionization cross section ratios. From the high-resolution x-ray emission spectra the energies and linewidths of the hypersatellite transitions, as well as the Kαh1:Kαh2 intensity ratios, were determined. The relative importance of the initial-state and final-state electron-electron interactions to the K-shell double photoionization is addressed. Physical mechanisms and scaling laws of the K-shell double photoionization are examined. A semiempirical universal scaling of the double- photoionization cross sections with the effective nuclear charge for neutral atoms in the range 2⩽Z⩽47 is established
High-energy-resolution grazing emission X-ray fluorescence applied to the characterization of thin Al films on Si
The grazing emission X-ray fluorescence (GEXRF) technique was applied to the analysis of different Al films, with nominal thicknesses in the range of 1 nm to 150 nm, on Si wafers. In GEXRF the sample volume from which the fluorescence intensity is detected is restricted to a near-surface region whose thickness can be tuned by varying the observation angle. This is possible because of the refraction of the fluorescence X-rays and the quite long emission paths within the probed sample. By recording the X-ray fluorescence signal for different shallow emission angles, defined relatively to the flat, smooth sample surface, the deposited Al surface layers of the different samples could be well characterized in terms of layer thickness, layer density, oxidation and surface roughness. The advantages offered by synchrotron radiation and the employed wavelength-dispersive detection setup were profited from. The GEXRF results retrieved were confirmed by complementary measurements. The experimental setup, the principles and advantages of GEXRF and the analysis of the recorded angular intensity profiles will be discussed in details
Physical mechanisms and scaling laws of K-shell double photoionization
We report on the photon energy dependence of the K-shell double photoionization (DPI) of Mg, Al, and Si. The DPI cross sections were derived from high-resolution measurements of x-ray spectra following the radiative decay of the K-shell double vacancy states. Our data evince the relative importance of the final-state electron-electron interaction to the DPI. By comparing the double-to-single K-shell photoionization cross-section ratios for neutral atoms with convergent close-coupling calculations for He-like ions, the effect of outer shell electrons on the K-shell DPI process is assessed. Universal scaling of the DPI cross sections with the effective nuclear charge for neutral atoms is revealed
Open and laparoscopic living donor nephrectomy in Switzerland: a retrospective assessment of clinical outcomes and the motivation to donate
Background. Laparoscopic living kidney nephrectomy is thought to be associated with reduced morbidity, when compared to open nephrectomy. The purpose of this study was to explore the impact of these techniques on donors' clinical outcomes, satisfaction and motivation to donate. Methods. Clinical outcomes were retrospectively compared in 152 open (n = 71) or laparoscopic (n = 81) donor procedures. Donor satisfaction and motivation were assessed with a self-administered questionnaire. Results. The complication rate was the same with both procedures and the majority of complications were mild. Laparoscopy was significantly less painful and resulted in an insignificantly faster return to active life. More than 80% of the donors volunteered to donate without pressure. Worries about future health status, pain or scars were not important in the decision to donate. Similarly, only 15% considered the surgical procedure as instrumental for their decision. Few donors currently worried about their health with one kidney and more than 95% of the donors in both groups stated that they would give their kidney again. Conclusions. Living donor nephrectomy is safe, regardless of the procedure used. Although the laparoscopic nephrectomy offers clear short-term benefits over the open nephrectomy, donors' satisfaction was excellent with both surgical approaches. Moreover, the type of procedure did not seem to influence their decision to donat
Entire solutions of hydrodynamical equations with exponential dissipation
We consider a modification of the three-dimensional Navier--Stokes equations
and other hydrodynamical evolution equations with space-periodic initial
conditions in which the usual Laplacian of the dissipation operator is replaced
by an operator whose Fourier symbol grows exponentially as \ue ^{|k|/\kd} at
high wavenumbers . Using estimates in suitable classes of analytic
functions, we show that the solutions with initially finite energy become
immediately entire in the space variables and that the Fourier coefficients
decay faster than \ue ^{-C(k/\kd) \ln (|k|/\kd)} for any . The
same result holds for the one-dimensional Burgers equation with exponential
dissipation but can be improved: heuristic arguments and very precise
simulations, analyzed by the method of asymptotic extrapolation of van der
Hoeven, indicate that the leading-order asymptotics is precisely of the above
form with . The same behavior with a universal constant
is conjectured for the Navier--Stokes equations with exponential
dissipation in any space dimension. This universality prevents the strong
growth of intermittency in the far dissipation range which is obtained for
ordinary Navier--Stokes turbulence. Possible applications to improved spectral
simulations are briefly discussed.Comment: 29 pages, 3 figures, Comm. Math. Phys., in pres
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