Prospects for modification of para-aramid fibres with metal complex salts in conditions of microwave exposure

The important possibility of conducting sol-gel synthesis of oxide systems on the surface of para-aramid fibres under the effect of microwave radiation was demonstrated. Selection and control of the basic process parameters (duration and intensity of exposure to electromagnetic radiation, concentration of salt and carbamide) allow regulating the effectiveness of interaction of the reaction system with the microwave field and eliminating degradation of the polymer, i.e., preserving its basicphysicomechanical indexes. __________ Translated from Khimicheskie Volokna, No. 3, pp. 18–20, May–June, 2007.     

Studying transient phase dynamics using the phase resetting method

A new method is proposed for the investigation of transitions from synchronous dynamics of coupled oscillators to asynchronous regimes attained upon synchronization breakage by a sequence of short phase resetting pulses. The possibility to use the proposed method for determining the coefficient of coupling between interacting systems from an analysis of the signals generated by these systems is considered.     

Features of the ion-implanted deuterium accumulation in Fe-Cr alloys with impurities

Small additives of silicon and antimony to a Fe-16% Cr alloy differently affect the segregation of ion-implanted deuterium in this material: silicon increases and antimony decreases the degree of deuterium accumulation. The phenomenon is explained by the impurity type influencing the properties of vacancy clusters in the target metal, which serve as traps for the implanted deuterium.     

Leukemia cutis. Fine needle aspiration findings

OBJECTIVE: To aspirate, for cytologic study, skin nodules from known cases of leukemia during full remission. STUDY DESIGN: The study group consisted of nine leukemia patients in full remission who developed skin nodules on the head, face, chest and upper extremities. RESULTS: The size of the nodules ranged between 1 and 3.5 cm. The nodules were aspirated with 21-gauge needle. Four were diagnosed as acute lymphoblastic leukemia, 1 as chronic lymphocytic leukemia, 1 as acute myeloblastic leukemia, 2 as acute monocytic leukemia and 1 as acute promyelocytic leukemia. Histologic sections were diagnosed as lymphoma-leukemia. The patients developed leukemia again three to four months after excision of the skin nodules. CONCLUSION: Fine needle aspiration cytology is useful in the diagnosis of leukemia cutis.     

Heat pulse monitoring of curing and polymer–gas systems

An implantable thermal probe is used to study the reaction of molten polymers and curing systems to pulse heat release. At the heating rates T˙≥5·10⁵K/s, a polymer system shows the response to pulse heating that is confined in time and reproducible with respect to temperature. This response is related to the abrupt change in the conditions of the contact between the probe and a substance. The temperature of the response T^* is determined by the polymer properties and depends on the pressure and T˙. The pulse thermal probe method, which includes two measuring procedures, complementing each other, has been used to monitor a number of processes in polymeric systems. The variation of the values of T^* and the thermal activity of a polymer is compared with the variation of its molecular weight (M?_n～ 10²–10⁶), the molecular weight distribution, and the concentration of a low molecular weight component. The method allows one to trace the kinetics of polymerization and curing and the kinetics of dissolution of volatile impurity and polymer devolatilization, and to determine the limit of supersaturation of gas solutions in molten polymers. The pulse repetition frequency is changed from 0.1 to 1 Hz. The heated volume of a substance is 10^?4 mm³. © 1994 John Wiley & Sons, Inc.     

Effects of cadmium, naphthalene, and DDVP on gut carbohydrases activity in bream (Abramis brama L.) and Mozambique tilapia (Oreochromis mossambicus Peters)

OBJECTIVE: To assess the antihyperglycemic activity of a new peripherally acting alpha 2-adrenergic receptor antagonist, SL 84.0418 in healthy volunteers METHODS: This was a randomized, double-blind crossover study. The effects of 10, 50, and 100 mg SL 84.0418 on blood glucose, plasma insulin, C-peptide, glucagon, epinephrine, and norepinephrine were investigated in comparison with placebo and 5 mg glipizide before and after an oral glucose challenge (75 gm). RESULTS: Peak blood glucose and area under the blood-glucose curve were dose-dependently reduced by SL 84.0418; the extent of this reduction was similar with 100 mg SL 84.0418 and glipizide. Glipizide but not SL 84.0418 decreased nadir blood glucose. Plasma insulin and C-peptide were increased by glipizide but not by SL 84.0418. Treatments did not modify plasma glucagon. Plasma epinephrine increased during glipizide treatment and plasma norepinephrine increased during treatment with 50 and 100 mg SL 84.0418. Systolic and diastolic blood pressure were moderately enhanced by 50 and 100 mg SL 84.0418. Adverse effects reflecting alpha 2-adrenergic receptor blockade occurred more frequently with 100 mg SL 84.0418. The adverse effect profile of 50 mg SL 84.0418 was not different from that observed with glipizide. CONCLUSION: The alpha 2-adrenergic receptor antagonist SL 84.0418 dose dependently reduced the increase in blood glucose after glucose load without modification of plasma insulin. It may represent an alternative to sulfonylureas in the treatment of non-insulin-dependent diabetes mellitus. Further studies are needed to assess its efficacy and tolerability in non-insulin-dependent patients.     

Adenocarcinoma arising in Barrett's oesophagus: evidence for the participation of p53 dysfunction in the dysplasia/carcinoma sequence

Adenocarcinoma arising in Barrett's oesophagus is often preceded by mucosal dysplasia, but little is currently known about the aetiology or natural history of this dysplasia/carcinoma sequence. To investigate the participation of the tumour suppressor gene p53 in this sequence, an immunohistochemical analysis of p53 protein overexpression, which is known to closely correlate with point mutation of the p53 gene, was conducted in 30 patients with Barrett's adenocarcinoma. Adjacent Barrett's mucosa was dysplastic in 21 (70%) patients. Sixteen (53%) tumours overexpressed p53, 10 of which had adjacent dysplastic Barrett's mucosa. In all 10 patients, this dysplastic mucosa also overexpressed p53, predominantly in areas of high grade compared with low grade dysplasia. In contrast, none of the dysplastic mucosa adjacent to 11 tumours lacking p53 overexpression showed detectable values of p53. These results suggest that p53 dysfunction may participate in the progression from dysplasia to carcinoma in some patients with Barrett's oesophagus.     

Atomic layer deposition of multilayer ZnTe/CdTe nanostructures

The growth of ultrathin zinc telluride and cadmium telluride films (nanostructures) and multilayer ZnTe/CdTe heterostructures by atomic layer deposition from molecular beams in vacuum is analyzed. The general trends of component chemisorption, growth mechanisms in different temperature ranges, and conditions for layer-by-layer growth are established.