Investigations regarding the drag characteristics of flow-disturbing bodies which are arranged in line and attached to the wall

The flow characteristics of rectangular bodies mounted on the base area of a rectangular closed wind tunnel are investigated. As many as four bodies are mounted in line with equal distances between successive bodies. The Mach number of the flowing air is in the range from 0.1 to 0.5. Total and individual drag values could be charged within a wide range by a suitable selection of the distance between successive bodies

Krefelderski test - novi eksperimentalni postupak za proučavanje toksičnosti kemikalija

During the last years, skin compatibility of textiles has gained importance for consumers. Therefore, the development of suitable test methods for the evaluation of skin compatibility is a vital challenge. The fundamental requirements for these test methods are low experimental complexity combined with minor costs. The Cilitatetest has been developed for the cosmetic and pharmaceutics industry. Due to the optical measurement of the number of living microorganisms, this method is not suitable for colored or heterogeneous samples. However, using a calorimetric detection, these problems are resolved. This method allows very sensitive detection of the metabolism of the microorganism. The presence of any toxic substance results in a reduction of the heat of metabolism.Kompatibilnost tekstila prema koži postajala je tijekom posljednjih godina sve važnija potrošačima. Zato je razvoj prikladnih postupaka ispitivanja za prosudbu kompatibilnosti s kožom primjeran izazov. Osnovni zahtjev postavljen za ove postupke ispitivanja jest eksperimentalna jednostavnost povezana s nižim troškovima. Ispitivanje trepetljikašima razvijeno je za kozmetičku i farmaceutsku industriju. Zbog optičkog mjerenja broja živih mikroorganizama taj postupak nije prikladan za obojene ili heterogene uzorke. Međutim, ti problemi su riješeni primjenom kalorimetijskog otkrivanja. Taj postupak otkrivanja omogućuje vrlo osjetljivo prepoznavanje metabolizma mikroorganizama. Postojanje bilo koje otrovne tvari znači smanjenje topline metabolizm

Plasma levels of granulocyte elastase during hemodialysis: Effects of different dialyzer membranes

Plasma levels of granulocyte elastase during hemodialysis: Effects of different dialyzer membranes. Plasma levels of granulocyte elastase in complex with α1-proteinase inhibitor during hemodialysis were investigated in 15 patients (37.4 ± 3.2 years) undergoing maintenance hemodialysis (47.0 ± 12.9 months) with dialyzers made from cellulose hydrate, cuprophan, polymethylmethacrylate, ethylene-vinyl alcohol copolymer, and polyacrylonitrile. Cellulose hydrate membrane caused a maximal increase of the plasma levels of granulocyte elastase in complex with α1-proteinase inhibitor (E-α1PI: 1,659.0 ± 256.8 ng/ml). Patients dialyzed with polyacrylonitrile dialyzers failed to exhibit comparable plasma levels of granulocyte elastase (E-α1 237.8 ± 22.9 ng/ml). During hemodialysis plasma E-α1PI values rose to a peak 643.0 ± 174.7 ng/ml in patients on polymethylmethacrylate dialyzers, to 557.5 ± 120.0 ng/ml on cuprophan dialyzers, but to only 381.9 ± 54.0 ng/ml on ethylene-vinyl alcohol copolymer dialyzers. Plasma lysozyme levels decreased significantly in the presence of polyacrylonitrile and polymethylmethacrylate membranes. We conclude that the degree of PMNs stimulation depends on the nature of the dialyzer membrane material. The following membranes induce a reaction of increasing intensity: polyacrylonitrile, ethylene-vinyl alcohol copolymer, cuprophan, polymethylmethacrylate, and cellulose hydrate

Some Factors Influencing Ante-Mortem Changes in Muscle: A Brief Review

Ante-mortem changes to muscle microstructure are influenced in many ways. During pre-natal cell differentiation and growth , myoblasts develop and mature into cells with quite different characteristics. Incorporated into the genome of these cells is the ability to synthesize a wide variety of filaments which occupy specific niches within each myofibril. During post-natal development , depending upon the particular precursor cell lines, different fiber types are produced. These are especially important in contributing to the ultimate palatability of meat. In this paper several factors which influence ante-mortem changes to muscle microstructure are discussed. While some of these are better understood than others, all of them , nevertheless, are importan

Nonlinear vertical oscillations of a particle in a sheath of a rf discharge

A new simple method to measure the spatial distribution of the electric field in the plasma sheath is proposed. The method is based on the experimental investigation of vertical oscillations of a single particle in the sheath of a low-pressure radio-frequency discharge. It is shown that the oscillations become strongly nonlinear and secondary harmonics are generated as the amplitude increases. The theory of anharmonic oscillations provides a good qualitative description of the data and gives estimates for the first two anharmonic terms in an expansion of the sheath potential around the particle equilibrium.Comment: 11 pages, 4 figure

Extractability and Intracellular Localisation of Urea Cycle Enzym es from Rat Liver

Peer Reviewe

Crystal structures of pure 3-(4-bromo-2-chlorophenyl)-1-(pyridin-4-yl) benzo [4, 5] imidazo [1, 2-d][1, 2, 4] triazin-4 (3H)-one and contaminated with 3-(4-bromophenyl)-1 …

The side product of the cyclocondensation reaction between ethyl benzimidazole-2-carboxylate and the nitrile imine of the corresponding hydrazonyl chloride, C20H11BrClN5O, crystallized in two crystal forms. Form (1) is a co-crystal of the target compound (without any chlorine substituent) and a side product containing a Cl atom in position 2 of the bromophenyl group, C20H12BrN5O·0.143C20H11BrClN5O. (2) contains the pure side product. The slightly different conformation of the ring systems leads to a different packing of (1) and (2), but both crystal structures are dominated by π–π interactions

2-(Benzyl­sulfan­yl)pyridine N-oxide

In the title compound, C12H11NOS, the dihedral angle between the oxopyridinium and phenyl rings is 58.40 (1)°. The crystal structure is stabilized by C—H⋯O hydrogen bonds, π–π stacking inter­actions involving the pyridinium rings [centroid–centroid distance = 3.6891 (9) Å] and C—H⋯π inter­actions

Future challenges in colloid and interfacial science

This article deals with topics where I expect special future challenges, exemplifying these by experiments out of my own department. One area where I expect large progress also in view of many technical developments in the past concerns the understanding of the structure of fluid interfaces at the atomic level. It is shown by non-linear optical spectroscopies that the free water surface is ice-like and can be “liquefied” by ion adsorption. X-ray fluorescence from the interface demonstrates that ion binding is very specific which cannot be explained by existing theories. A second major area are nonequilibrium features, and one of the old and new ones here is nucleation and growth. This presentation concentrates on effects produced by ultrasound, a well-defined trigger of gas bubble formation. It exhibits high potential for chemistry at extreme conditions but with a reactor at normal conditions. It has special importance for treatment of surfaces that can be also manipulated via controlled surface energies. A third area will concern complex and smart systems with multiple functions in materials and biosciences. As next generation, I anticipate those with feedback control, and examples on this are self-repairing coatings

Distinct Regulatory Functions of Calpain 1 and 2 during Neural Stem Cell Self-Renewal and Differentiation

Calpains are calcium regulated cysteine proteases that have been described in a wide range of cellular processes, including apoptosis, migration and cell cycle regulation. In addition, calpains have been implicated in differentiation, but their impact on neural differentiation requires further investigation. Here, we addressed the role of calpain 1 and calpain 2 in neural stem cell (NSC) self-renewal and differentiation. We found that calpain inhibition using either the chemical inhibitor calpeptin or the endogenous calpain inhibitor calpastatin favored differentiation of NSCs. This effect was associated with significant changes in cell cycle-related proteins and may be regulated by calcium. Interestingly, calpain 1 and calpain 2 were found to play distinct roles in NSC fate decision. Calpain 1 expression levels were higher in self-renewing NSC and decreased with differentiation, while calpain 2 increased throughout differentiation. In addition, calpain 1 silencing resulted in increased levels of both neuronal and glial markers, β-III Tubulin and glial fibrillary acidic protein (GFAP). Calpain 2 silencing elicited decreased levels of GFAP. These results support a role for calpain 1 in repressing differentiation, thus maintaining a proliferative NSC pool, and suggest that calpain 2 is involved in glial differentiation