The emergence of silent myocardial ischemia as the manifestation of the nitrate withdrawal syndrome in patients with ischemic heart disease

A patient is described, who was examined 1 year after surgery for mandibular cyst diagnosed as radicular near the !5 tooth and for plasty of the secondary osseous cavity with hydroxyapatite granulate. X-Ray examination revealed a cystic cavity near the roots of teeth !234. Histologic examination of tissue fragments and the remainder of hydroxyapatite granulate, obtained by cystectomy, helped diagnose a primordial cyst. Intensive bone regeneration was observed at the site of hydroxyapatite granule accumulation and fusion of the new bone with the granules to form a solid osseogranular complex. The authors recommend hydroxyapatite ceramic granules for surgical treatment of minor and medium bone defects and for corrective bone plasty.     

Ophthalmic tone of myopic eyes: statistical evaluation and role in formation of acquired myopia

The author summarizes the results of many-year profound statistical analysis of ophthalmic tone in myopic patients. Intraocular pressure (IOP) of myopic eyes in patients aged 10 to 62 years and refraction from 0.5 to -24.0 diopters was measured in 1220 eyes by the same type of Goldman's tonometer. Detailed distribution of IOP for age and refraction factor is presented. IOP has been studied in emmetropia, stable and progressive myopia, and in paired anisometropic eyes. The author emphasizes that myopia progresses at various levels of ophthalmic tone, whose increase is mainly functional and reversible, and is caused by organic changes in the anterior chamber angle in only 7% of cases. The author claims that IOP is an important characteristic of a myopic eye and is to be taken into consideration when prescribing pathogenetic therapy for progressive myopia.     

Dependence of cardiovascular effects of adenosine on the blood circulation type in rats

Administration of adenosine increased the RR interval in greater degree at hyper- than in hypodynamic blood circulation type. The AV-blockade and atrial flutter were maximal in rats with hyperdynamic type of blood circulation. Propranolol weakened the adenosine cardiotropic effect whereas cholinoblockators enhanced it. Neurohumoral regulation exerted no effect on the adenosine hypotensive action.     

A comparative study of carboxylesterase in the white mouse and in the caterpillar of the cotton bollworm Heliothes armigera

Studies have been made on enzymic hydrolysis of p-nitrophenylacetate (p-NPhAc), n-nitrophenylbutyrate (p-NPhBu) and indophenylacetate (IPhAc) by carboxylesterase (CE) from mouse blood plasma and liver as well as from caterpillar of the cotton worm haemolymph, intestine and fat body. Different KM and V max values were obtained for CE from these sources. The highest specific activity of CE from mouse liver and caterpillar intestine and fat body was observed with p-NPhBu. p-NPhAc is the best substrate for CE from mouse blood serum and caterpillar haemolymph. Carboxylesterases from mouse and caterpillar differed in their sensitivity to armine and paraoxone by 1-2 orders depending on the substrate used. Species and tissue differences in the kinetics of CE-catalyzed reactions with different substrates and inhibitors were revealed.     

Electrooxidation of Cr<Superscript>3+</Superscript> ions in sulfuric acid solutions

The effects the material nature of an anode, the cation radius and the metal-oxygen bond strength in the oxide anode on the rates of Cr³⁺ ion electrooxidation and the anode corrosion. A correlation between the rates of Cr³⁺ cation electrooxidation and corrosion of the anodes made of different metals is revealed. It is shown that the electrocatalytic activity of oxide anodes in the Cr³⁺ electrooxidation is caused by crystallographic and energy factors. The highest electrocatalytic activity is demonstrated by the oxides whose metal cation radius exceeds that of dehydrated Cr³⁺ cation and the M-O bond energy is smaller than the bond energy in Cr₂O₃. The equation suggested takes simultaneously into account the effects of the oxide electrode cation radius and the mean energy of M-O bond on the relative rate of the Cr³⁺ ion electrooxidation.     

Comparison of tribological characteristics of nanostructured TiN,MoN, and TiN/MoN Arc-PVD coatings

The tribological properties of TiN, MoN, and TiN/MoN coatings have been investigated. It has been shown that, for multilayer (alternate) TiN/MoN coatings, a maximum hardness reaches 29–31 GPa that is significantly less than the hardness of MoN coatings (36.0–40.2 GPa) when changing the deposition conditions. MoN coatings possess lower coefficients of friction compared to TiN coatings, in particular at the initial stages of a scratch test. Two mechanisms of destruction are revealed by the adhesion tests, i.e., a cohesive failure with a minimum critical loading L _C1 and an adhesive test (plastic abrasion) with the appearance of a first crack L _C2. The resistance of multilayer (nanoscale) nanostructured TiN/MoN coatings with a total thickness of up to 8 μm is greater than that of TiN coatings.