A novel human type II cytokeratin, K6hf, specifically expressed in the companion layer of the hair follicle

In an attempt to identify new members of the human type II hair keratin family by means of 3'- and 5'-RACE methods and cDNA from anagen hair follicles, we detected a sequence that encoded a hitherto unknown type II cytokeratin. The novel cytokeratin comprises 251 amino acids and exhibits the highest sequence homology with K5. Comparative one- and two-dimensional western blots of keratins from anagen hair bulbs, containing or not containing the outer and inner root sheaths (ORS/IRS), and from footsole epidermis with an antibody against the new cytokeratin, revealed its comigration with K6 and its expression in the ORS/IRS complex. We have therefore named the new cytokeratin K6hf, to distinguish it from the various K6 isoforms and to indicate its expression in the hair follicle. Both in situ hybridization with a K6hf-specific cRNA probe and indirect immunofluorescence with the K6hf antibody showed that K6hf is exclusively expressed in the so-called "companion layer" of the hair follicle, a single layered band of flat and vertically oriented cells between the cuboidal ORS cells and the IRS that stretches from the lowermost bulb region to the isthmus of the follicle. Concomitant K17 and K16 expression studies showed that besides suprabasal ORS cells, these cytokeratins are sequentially expressed subsequent to K6hf in companion cells above the hair bulb. Our study confirms the view of a vertically oriented companion layer differentiation. The clearly delayed K17 and K16 expression relative to that of K6hf in companion cells most probably excludes these keratins as possible type I partners of K6hf and suggests the existence of a still unknown type I partner of its own. Thus, not only morphologically but also biochemically, the companion layer is different from the ORS and can therefore be regarded as an independent histologic compartment of the hair follicle.     

Sex-related differences in foot shape of adult Caucasians--a follow-up study focusing on long and short feet

The study's purpose was to substantiate findings on sex-related differences in foot morphology focusing on fringe sizes. Altogether, 287 Caucasian adults with long or short feet were scanned. Data were analysed together with data from 847 subjects from a previous study with comparable inclusion criteria and anthropometric data by: (1)comparing absolute measures within 237-277 mm foot length (FL); (2) comparing averaged measures across sizes in % of foot length for 203-323 mm FL; (3) reclassifying the additional subjects into a previously defined foot type classification. Male feet were wider and higher for the same FL. Averaged across sizes, no relevant differences between sexes were found for widths and heights. Slender or flat-pointed foot types were more common in longer feet, shorter feet tended to be bigger. Definitions for 'long' and 'short' are sex-related with an offset of three shoe sizes (EU). Results of this follow-up study on long and short feet can substantiate previous findings mainly described for the most common sizes. STATEMENT OF RELEVANCE: Improper footwear can cause pain and injury and proper fit is a major criterion for shoe buyers. Knowledge about sex-related differences in foot shape is important for shoe design. This study supplements the field of knowledge for very small and large feet.     

Fast and effective feature-preserving mesh denoising

We present a simple and fast mesh denoising method, which can remove noise effectively, while preserving mesh features such as sharp edges and corners. The method consists of two stages. Firstly, noisy face normals are filtered iteratively by weighted averaging of neighboring face normals. Secondly, vertex positions are iteratively updated to agree with the denoised face normals. The weight function used during normal filtering is much simpler than that used in previous similar approaches, being simply a trimmed quadratic. This makes the algorithm both fast and simple to implement. Vertex position updating is based on the integration of surface normals using a least-squares error criterion. Like previous algorithms, we solve the least-squares problem by gradient descent, but whereas previous methods needed user input to determine the iteration step size, we determine it automatically. In addition, we prove the convergence of the vertex position updating approach. Analysis and experiments show the advantages of our proposed method over various earlier surface denoising methods.     

Mitotic Diversity in Homeostatic Human Interfollicular Epidermis

Despite decades of skin research, regulation of proliferation and homeostasis in human epidermis is still insufficiently understood. To address the role of mitoses in tissue regulation, we utilized human long-term skin equivalents and systematically assessed mitoses during early epidermal development and long-term epidermal regeneration. We now demonstrate four different orientations: (1) horizontal, i.e., parallel to the basement membrane (BM) and suggestive of symmetric divisions; (2) oblique with an angle of 45°–70°; or (3) perpendicular, suggestive of asymmetric division. In addition, we demonstrate a fourth substantial fraction of suprabasal mitoses, many of which are committed to differentiation (Keratin K10-positive). As verified also for normal human skin, this spatial mitotic organization is part of the regulatory program of human epidermal tissue homeostasis. As a potential marker for asymmetric division, we investigated for Numb and found that it was evenly spread in almost all undifferentiated keratinocytes, but indeed asymmetrically distributed in some mitoses and particularly frequent under differentiation-repressing low-calcium conditions. Numb deletion (stable knockdown by CRISPR/Cas9), however, did not affect proliferation, neither in a three-day follow up study by life cell imaging nor during a 14-day culture period, suggesting that Numb is not essential for the general control of keratinocyte division.     

Photooxidation von Leukofarbstoffen. X. Untersuchungen zur Photooxidation von Di-kalium-anthracen-9,10-ylen-bis-sulfat

Photooxidation of Leuco Dyes. X. Investigation of the Photooxidation of Di-potassiumanthracene 9,10-ylene-di-sulfate Photolysis of the title compound (DHAE) in water or ethanol produces anthraquinone and anthrone. In deoxygenated solutions 9,10-dihydroxyanthracene is detected as a long lived intermediate. Laser and conventional flash photolysis reveals three short-lived transients with lifetimes of 200 ns, 2 and 410 ms. Different temperature dependencies are observed for the fluorescence and the photolysis quantum yields. This is interpreted by two successive thermally activated processes: photohomolysis of O S bond and escape of the radical pair from the solvent cage. The results are discussed with the help of a reaction scheme proposed for the photolysis of DHAE.     

Photooxidation von Leukofarbstoffen. XII. Kurzzeitspektroskopische Untersuchungen zur Photooxidation von Bis-schwefelsäuremonoestern der Leukoformen von Thioindigoverbindungen

Photooxidation of Leuco Dyes. XII. Time Resolved Investigations on the Photooxidation of Bis-sulfuric Acid Monoesters of Leucothioindigoid Compounds The photooxidation of 4, 4′-dimethyl-6, 6′-dichlorothioindigosol ( 1 ) was studied by means of laser and conventional flash photolysis. Three transients were detected and assigned to a radical R generated by homolytic splitting of one O S-bond of the parent compound and to two further radicals which are formed from R by hydrolytic cleavage of the second ester group. The latter two radicals are in a protolytic equilibrium with each other and react, depending on the nature of the solvent by H-atom abstraction, or by disproportionation forming the leuco-thioindigoid dye or both dye and leuco dye. A mechanistic scheme is proposed.     

Numerical Simulation of Dispersed Gas/Liquid Flows in Bubble Columns at High Phase Fractions using OpenFOAM®. Part I – Modeling Basics

Various chemical products are synthesized in processes using gas/liquid reactors with bubbly flows. Hence, there is a significant interest in a more efficient process design as well as in process intensification with a strong focus on this reactor class. However, the design of industrial gas/liquid reactors requires more detailed information about the flow structures and characteristics of two‐ or multiphase systems. The basic models for two‐fluid model simulations of dispersed gas/liquid flows in bubble columns at high gas fractions are presented.     

Numerische Simulation disperser Gas/Flüssig‐Strömungen in Blasensäulen bei hohen Gasgehalten mit OpenFOAM®. Teil 2 – Numerische Simulation und Ergebnisse

The design of industrial gas/liquid reactors such as bubble columns requires detailed information with respect to the flow structure and characteristics of two‐ or multiphase systems in the reactor. The contribution is focused on the evaluation of the simulation results obtained by a selection of models. The results are further compared with those reported in literature. The simulations have been performed with the CFD software OpenFOAM®. The main focus of the numerical simulation was set on capturing the characteristic process and design parameters of bubble columns.     

Spectral hole-burning and carrier-heating dynamics in InGaAsquantum-dot amplifiers

The ultrafast gain and index dynamics in a set of InAs-InGaAs-GaAs quantum-dot (QD) amplifiers are measured at room temperature with femtosecond resolution. The role of spectral hole-burning (SHB) and carrier heating (CH) in the recovery of gain compression is investigated in detail. An ultrafast recovery of the spectral hole within ~100 fs is measured, comparable to bulk and quantum-well amplifiers, which is contradicting a carrier relaxation bottleneck in electrically pumped QD devices. The CH dynamics in the QD is quantitatively compared with results on an InGaAsP bulk amplifier. Reduced CH for both gain and refractive index dynamics of the QD devices is found, which is a promising prerequisite for high-speed applications. This reduction is attributed to reduced free-carrier absorption-induced heating caused by the small carrier density necessary to provide amplification in these low-dimensional systems