Mechanism of production of intestinal secretion by negative luminal pressure

The relationships between luminal hydrostatic pressure and fluid transport by dog jejunum in vivo studied as a sheet in the Wells clamp were compared with quantitative predictions from a model proposed for the mechanism of the secretion produced by elevated venous pressure. According to the model, the secretion produced by increasing venous pressure and the secretion produced by negative luminal pressure are both passive filtrates contingent on a transepithelial pressure of a few centimeters of H2O. We consider that the agreement between the observed and predicted responses to luminal pressure provides strong support for the model. In particular, a) the observations displayed a predicted gross asymmetry in rates of fluid transfer with isotonic fluids depending on whether the luminal pressure was positive or negative; b) the observed magnitude of the negative luminal pressure required for the onset of secretion agreed with predictions; and c) the secretion contained significant amounts of protein at about 25% of the plasma concentration.     

Use of the method of mixed substrates to study the specificity of tRNA methylases

The absence of summation of the rate of methylation of positionally analogous cytidine residues in tRNA1Val, tRNAPhe, and tRNAMet in the case of simultaneous presence of two substrates in the incubation mixture was demonstrated by the method of mixed substrates. The same result was also obtained in the methylation of A19 (counting from the 3' end of the molecule) in tRNA1Val, tRNAPhe, tRNAfMet, tRNASer, and tRNAGlu individually and in the case of their mixing in pairs. These data are evidence that positionally analogous nucleotides in different RNAs are attacked by the same enzyme. Yeast tRNASer, already possessing a methyl group at the cytidine residue studied, proved to be an effective inhibitor of methylase, forming m5C with valine and phenylalanine tRNAs. The results obtained are evidence that differences in the primary and secondary structures at the site of methylation are not the deciding factors in the interaction of tRNA with methylases.     

Ultrastructural changes in the mycelia of Actinomyces hygroscopicus var. var. enhygrus--a proteolytic enzyme producer--during submerged fermentation

Ultrastructural changes were found to occur in the mycelium of Actinomyces hygroscopicus, strain 33x, which produced an exocellular proteolytic enzyme during submerged fermentation, in both laboratory and semiindustrial conditions (in 100-1 fermenters). In the course of the enzyme accumulation, numerous vacuoles appeared in the hyphae, some hyphae became wider, and the cell walls were more loose. The greatest structural changes were found in the intracytoplasmic membrane systems. The ultrastructural changes of the mycelium are not presumably connected with the accumulation of the enzyme, but are the result of the differentiation of cellular structures during aging of the cells and their transition to the stage of autolysis.     

Provision of apparatus to resuscitation and intensive therapy departments of the cardiology service

The article describes monitoring systems for following critically-ill patients, and cardio-resuscitation complex, apparatus for defibrillation, and short-term anaesthesy, cardiostimulators. All these units have been elaborated and serially produced by the Radioelectronic Medical Equipment Association. Their importance and place in providing the patients treatment and diagnosis in resuscitation and intensive care departments of the cardiological service are shown.     

Results of cemented metal-backed acetabular components: a 10-year-average follow-up study

We have developed a computer program for the rapid assessment of the primary structure differences between a protein of unknown sequence and a homologous known protein. Both proteins are reduced, alkylated, and digested with the same hydrolytic agent. The unfractionated peptide mixtures are submitted to automatic sequence analysis. Based on the knowledge of the reference sequence, the program utilizes the analysis data to identify all the potential peptides present in the two mixtures, determining their primary structure, homology degree, and molecular weight calculated both as integer MH+ and average mass variables. These fingerprints allow the user to easily identify the structural differences between the two proteins and clarify possible doubts by a mass spectrometric analysis of the two mixtures. In order to verify the utility of the program, we provide an application example using the already reported data of two homologous proteins.     

Soft solution fluorine-free synthesis of anatase nanoparticles with tailored morphology

TiO₂ nanoparticles with tailored morphology have been synthesized under exceptionally soft conditions. The strategy is based on the use of a non-aqueous alcoholic reaction medium in which water traces, coming either from the air (atmospheric water) or from an ethanol–water azeotropic mixture (ethanol 96%), are incorporated in order to accelerate hydrolysis of the Ti–precursor. Moreover, organic surfactants have been used as capping agents so as to tailor crystal growth in certain preferential directions. Combinations of oleic acid and oleylamine, which lead to the formation of another surfactant, dioleamide, are employed instead of fluorine-based compounds, thus increasing the sustainability of the process. As a result, TiO₂ nanostructured hierarchical microspheres and individual nanoparticles with exposed high-energy facets can be obtained at atmospheric pressure and temperatures as low as 78 °C.