853 research outputs found
Tissue engineering and ENT surgery
Tissue engineering is the development of biological substitutes for the repair and regeneration of damaged tissues. We explain the principles of this emerging field of biotechology. The present and potential applications of tissue engineering technologies in ENT surgery are then reviewed
Endothelin and nitric oxide synthase in lymphatic endothelial cells: Immunolocalization in vivo and in vitro
A Framework for Generalising the Newton Method and Other Iterative Methods from Euclidean Space to Manifolds
The Newton iteration is a popular method for minimising a cost function on
Euclidean space. Various generalisations to cost functions defined on manifolds
appear in the literature. In each case, the convergence rate of the generalised
Newton iteration needed establishing from first principles. The present paper
presents a framework for generalising iterative methods from Euclidean space to
manifolds that ensures local convergence rates are preserved. It applies to any
(memoryless) iterative method computing a coordinate independent property of a
function (such as a zero or a local minimum). All possible Newton methods on
manifolds are believed to come under this framework. Changes of coordinates,
and not any Riemannian structure, are shown to play a natural role in lifting
the Newton method to a manifold. The framework also gives new insight into the
design of Newton methods in general.Comment: 36 page
ATHLOS Healthy Aging Scale score as the predictor of all-cause mortality in Poland and Czechia
Background: The ATHLOS consortium (Aging Trajectories of Health-Longitudinal Opportunities and Synergies) used data from several aging cohorts to develop a novel scale measuring healthy aging comprehensively and globally (ATHLOS Healthy Aging Scale). In the present study, we assessed the predictive performance of the ATHLOS Healthy Aging Scale for all-cause mortality in middle-aged and older adults. Methods: Data from the Polish and Czech HAPIEE (Health Alcohol and Psychosocial factors In Eastern Europe) prospective cohorts were used. There were 10,728 Poles and 8,857 Czechs recruited. The ATHLOS Healthy Aging Scale score was calculated for all participants using data from the baseline examination carried out from 2002 to 2005. The follow-up for all-cause mortality was completed over 14 years. The associations between quintiles of the ATHLOS Healthy Aging Scale and all-cause mortality were estimated using Cox proportional hazards models. Results: A total of 9,922 Polish and 8,518 Czech participants contributed ATHLOS Healthy Aging Scale and mortality data with 1,828 and 1,700 deaths, respectively. After controlling for age, the ATHLOS Healthy Aging Scale score was strongly associated with mortality in a graded fashion for both genders and countries (hazard ratios for lowest vs. highest quintile were 2.98 and 1.96 for Czech and Polish women and 2.83 and 2.66 for Czech and Polish men, respectively). The associations were only modestly attenuated by controlling for education, economic activity, and smoking, and there was further modest attenuation after additional adjustment for self-rated health. Conclusion: The novel ATHLOS Healthy Aging Scale is a good predictor of all-cause mortality in Central European urban populations, suggesting that this comprehensive measure is a useful tool for the assessment of the future health trajectories of older persons
Ca2+-Mg2+-dependent ATP-ase activity in hemodialyzed children. Effect of a hemodialysis session
In the course of chronic kidney disease (CKD) the intracellular erythrocyte calcium (Cai2+) level increases along with the progression of the disease. The decreased activity of Ca2+-Mg2+-dependent ATP-ase (PMCA) and its endogenous modulators calmodulin (CALM), calpain (CANP), and calpastatin (CAST) are all responsible for disturbed calcium metabolism. The aim of the study was to analyze the activity of PMCA, CALM, and the CANP-CAST system in the red blood cells (RBCs) of hemodialyzed (HD) children and to estimate the impact of a single HD session on the aforementioned disturbances. Eighteen patients on maintenance HD and 30 healthy subjects were included in the study. CALM, Cai2+ levels and basal PMCA (bPMCA), PMCA, CANP, and CAST activities were determined in RBCs before HD, after HD, and before the next HD session. Prior to the HD session, the level of Cai2+ and the CAST activity were significantly higher, whereas bPMCA, PMCA, and CANP activities and the CALM level were significantly lower than in controls. After the HD session, the Cai2+ concentration and the CAST activity significantly decreased compared with the basal values, whereas the other parameters significantly increased, although they did not reach the levels of healthy children. The values observed prior to both HD sessions were similar. Cai2+ homeostasis is severely disturbed in HD children, which may be caused by the reduction in the PMCA activity, CALM deficiency, and CANP-CAST system disturbances. A single HD session improved these disturbances but the effect is transient
Different fetal-neonatal outcomes in siblings born to a mother with Graves-Basedow disease after total thyroidectomy: a case series
ABSTRACT:INTRODUCTION: We describe three different fetal or neonatal outcomes in
the offspring of a mother who had persistent circulating thyrotropin receptor
antibodies despite having undergone a total thyroidectomy several years before.
CASE PRESENTATION: The three different outcomes were an intrauterine death, a
mild and transient fetal and neonatal hyperthyroidism and a severe fetal and
neonatal hyperthyroidism that required specific therapy.
CONCLUSIONS: The three cases are interesting because of the different outcomes,
the absence of a direct correlation between thyrotropin receptor antibody levels
and clinical signs, and the persistence of thyrotropin receptor antibodies
several years after a total thyroidectomy
Modeling and Measurement of Field and Flux of MPI
Magnetic particle inspection (MPI) is one of the oldest NDT techniques and it is the most common method used to detect surface defects in ferromagnetic materials. But since the beginning MPI has been based on experiments, experience and on subjective judgements. This contribution shows for the first time how MPI of complex shaped parts can be designed objectively by applying Maxwell equations and finite element calculations. The comparison between modelling and measurement shows substantial agreement. Results are given and discussed especially for automotive components like crankshaft and hub under DC- as well as AC-magnetization using coils and yokes
Inhibition of activin/nodal signalling is necessary for pancreatic differentiation of human pluripotent stem cells
Peer reviewedPublisher PD
Age and gender dependent heart rate circadian model development and performance verification on the proarrhythmic drug case study
Enrichment analysis of Alu elements with different spatial chromatin proximity in the human genome
Transposable elements (TEs) have no longer been totally considered as “junk DNA” for quite a time since the continual discoveries of their multifunctional roles in eukaryote genomes. As one of the most important and abundant TEs that still active in human genome, Alu, a SINE family, has demonstrated its indispensable regulatory functions at sequence level, but its spatial roles are still unclear. Technologies based on 3C(chromosomeconformation capture) have revealed the mysterious three-dimensional structure of chromatin, and make it possible to study the distal chromatin interaction in the genome. To find the role TE
playing in distal regulation in human genome, we compiled the new released Hi-C data, TE annotation, histone marker annotations, and the genome-wide methylation data to operate correlation analysis, and found that the density of Alu elements showed a strong positive correlation with the level of chromatin interactions (hESC: r=0.9, P<2.2×1016; IMR90 fibroblasts: r = 0.94, P < 2.2 × 1016) and also have a significant positive correlation withsomeremote functional DNA elements like enhancers and promoters (Enhancer: hESC: r=0.997, P=2.3×10−4; IMR90: r=0.934, P=2×10−2; Promoter: hESC: r = 0.995, P = 3.8 × 10−4; IMR90: r = 0.996, P = 3.2 × 10−4). Further investigation involving GC content and methylation status showed the GC content of Alu covered sequences shared a similar pattern with that of the overall sequence, suggesting that Alu elements also function as the GC nucleotide and CpG site provider. In all, our results suggest that the Alu elements may act as an alternative parameter to evaluate the Hi-C data, which is confirmed by the correlation analysis of Alu elements and histone markers. Moreover, the GC-rich Alu sequence can bring high GC content and methylation flexibility to the regions with more distal chromatin contact, regulating the transcription of tissue-specific genes
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