Humboldt University of Berlin

About: Humboldt University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Population & Transplantation. The organization has 33671 authors who have published 61781 publications receiving 1908102 citations. The organization is also known as: Humboldt-Universität zu Berlin & Universitas Humboldtiana Berolinensis.

Quantification of Blood Flow in Brain Tumors: Comparison of Arterial Spin Labeling and Dynamic Susceptibility-weighted Contrast-enhanced MR Imaging

Abstract: PURPOSE: To implement an arterial spin labeling technique that is feasible in routine examinations and to test the method and compare it with dynamic susceptibility-weighted contrast material–enhanced magnetic resonance (MR) imaging for evaluation of tumor blood flow (TBF) in patients with brain tumors. MATERIALS AND METHODS: Thirty-six patients with histologically proven brain tumors were examined at 1.5 T. A second version of quantitative imaging of perfusion by using a single subtraction with addition of thin-section periodic saturation after inversion and a time delay (Q2TIPS) technique of pulsed arterial spin labeling in the multisection mode was implemented. After arterial spin labeling, a combined T2- and T2*-weighted first-pass bolus perfusion study (gadopentetate dimeglumine, 0.2 mmol/kg) was performed by using a double-echo echo-planar imaging sequence. In regions of interest, maps of absolute and relative cerebral blood flow were computed and analyzed with arterial spin labeling and dynamic sus...

A Meta-Analytic Path Analysis of the Internal/External Frame of Reference Model of Academic Achievement and Academic Self-Concept

Abstract: A meta-analysis of 69 data sets (N = 125,308) was carried out on studies that simultaneously evaluate the effects of math and verbal achievements on math and verbal self-concepts. As predicted by the internal/external frame of reference (I/E) model, math and verbal achievements were highly correlated overall (.67), but the correlation between math and verbal self-concepts (.10) was close to zero. Correlations between math and verbal achievement and correlations between achievements and self-concepts within the domains were more positive when grades instead of standardized test results were used as achievement indicators. A path analysis revealed support for the I/E model, with positive paths from achievement to the corresponding self-concepts (.61 for math, .49 for verbal) and negative paths from achievement in one subject to self-concept in the other subject (−.21 from math achievement on verbal self-concept, −.27 from verbal achievement to math self-concept). Furthermore, results showed that the I/E mod...

Extensive reorganization of the somatosensory cortex in adult humans after nervous system injury

Abstract: MAGNETIC source imaging revealed that the topographic representation in the somatosensory cortex of the face area in upper extremity amputees was shifted an average of 1.5 cm toward the area that would normally receive input from the now absent nerves supplying the hand and fingers. Observed alterat

Increased Expression of Transient Receptor Potential Vanilloid-1 in Airway Nerves of Chronic Cough

Abstract: Transient receptor potential vanniloid-1 (TRPV-1) mediates the cough response induced by the pepper extract capsaicin and is expressed in sensory nerves that innervate the airway wall. We determined the expression of TRPV-1 in the airways of patients with chronic persistent cough of diverse causes and with an enhanced capsaicin cough response. We obtained airway mucosal biopsies by fiberoptic bronchoscopy in 29 patients with chronic cough and 16 healthy volunteers without a cough. Immunostaining for nerve profiles with anti-protein gene product (PGP)-9.5 antibody showed no increase in nerve profiles in the airway epithelium of patients with chronic cough; however, with an anti-TRPV-1 antibody, there was a fivefold increase of TRPV-1 staining nerve profiles (p < 0.001). There was a significant correlation between capsaicin tussive response and the number of TRPV-1-positive nerves within the patients with cough. Our findings indicate that TRPV-1 receptors may contribute to an enhanced cough reflex and the cough response in chronic persistent cough of diverse causes.

Normalization strategies for cDNA microarrays

Abstract: Multiple Arabidopsis thaliana clones from an experimental series of cDNA microarrays are evaluated in order to identify essential sources of noise in the spotting and hybridization process. Theoretical and experimental strategies for an improved quantitative evaluation of cDNA microarrays are proposed and tested on a series of differently diluted control clones. Several sources of noise are identified from the data. Systematic and stochastic fluctuations in the spotting process are reduced by control spots and statistical techniques. The reliability of slide to slide comparison is critically assessed within the statistical framework of pattern matching and classification.