Influence of surface curvature on gaseous exchange in a glass-gas system

The influence of interface curvature on the solubility of an inert gas in the condensed phase with a convex surface (a droplet) and a concave surface (a bubble) is theoretically studied. Numerical examples are given for the “vitreous silica-helium” system. Gaseous exchange for various combinations of interface shapes typical of glass processing is considered.     

Confinement-guided shaping of semiconductor nanowires and nanoribbons: "writing with nanowires"

To fully exploit their full potential, new semiconductor nanowire building blocks with ab initio controlled shapes are desired. However, and despite the great synthetic advances achieved, the ability to control nanowire's geometry has been significantly limited. Here, we demonstrate a simple confinement-guided nanowire growth method that enables to predesign not only the chemical and physical attributes of the synthesized nanowires but also allows a perfect and unlimited control over their geometry. Our method allows the synthesis of semiconductor nanowires in a wide variety of two-dimensional shapes such as any kinked (different turning angles), sinusoidal, linear, and spiral shapes, so that practically any desired geometry can be defined. The shape-controlled nanowires can be grown on almost any substrate such as silicon wafer, quartz and glass slides, and even on plastic substrates (e.g., Kapton HN).     

Procedure of RNA extraction which does not extract DNA and proteins from nervous tissue cells.

Several schemes of acidic extraction of RNA taken from biochemical or cytochemical literature were compared by means of ultraviolet and visible cytospectrophotometry. Basing on the data obtained an extraction scheme has been recommended which consists in the treatment of nervous tissue sections with 16 per cent perchloric acid at 4 degrees C for 48 h. This extraction has been shown to extract completely cellular RNA without extracting DNA and proteins from the nervous tissue cells. Using this scheme, ultraviolet cytospectrophotometry of neurons and glial cells was performed twice, before and after the selective RNA extraction, which enabled a calculation of RNA concentration by the difference of the absorption values. In mice, after 3 h-swimming, and in cats, after 2-week daily injections of adrenaline, a number of quantitative and qualitative RNA changes were found out in nerve and glial cell of mouse spinal cord and cat sympathetic ganglion with the aid of the recommended scheme of RNA extraction.     

Kinetic properties of the activator complexes plasmin--staphylokinase and plasmin(ogen)--streptokinase in vitro

The thiazole orange dye 1,1'-(4,4,8,8-tetramethyl-4, 8-diazaundecamethylene)-bis-4-[(3-methyl-2,3-dihydro-2(3H)-benzo-1 ,3-thiazolylidene)methyl]quinolinium tetraiodide (TOTO) binds to double-stranded DNA (dsDNA) in a sequence selective bis-intercalation. We have examined the binding of derivatives of TOTO with different substituents on the benzothiazole ring. The analogues are the following: 1,1'-(4,4,8,8-tetramethyl-4, 8-diazaundecamethylene)-[4-[3-(benzyl-2, 3-dihydro-2-(3H)-benzothiazolylidene)methyl]quinolinium]-[4-[3-(++ +methy l-2, 3-dihydro-2-(3H)-benzothiazolylidene)methyl]quinolinium]tetraio dide (TOTOBzl) and 1,1'-(4,4,8,8-tetramethyl-4, 8-diazaundecamethylene)-bis-4-[(3-ethyl-2,3-dihydro-2(3H)-benzo-1, 3-thiazole)methyl]quinolinium tetraiodide (TOTOEt). In this paper, we report the synthesis of TOTOBzl and TOTOEt together with the one- and two-dimensional 1H NMR investigations of complexes between these TOTO analogues and the dsDNA oligonucleotide d(CGCTAGCG)2. Both analogues yield extremely stable complexes in which each chromophore is sandwiched between two base pairs in a (5'-CpT-3'):(5'-ApG-3') site. The linker spans over two base pairs in the minor groove. The benzyl group in TOTOBzl and the ethyl groups in TOTOEt is pointing outward in the major groove.     

Stress, adaptation, and nitric oxide

The biological role of nitric oxide (NO) has been studied for more than ten years. Nevertheless, the number of investigations in this field continues to increase. It is now suggested that NO is a previously unrecognized, very important regulator of physiological functions and cell metabolism in the body. Through the application of the methods of molecular biology, more and more data are being accumulated on the regulatory role of NO in the mechanism of gene expression and protein biosynthesis. The data presented in this review show an important role of NO in stress and adaptive responses of organisms and thereby expand existing notions on the biological role of this unique molecule. This review substantiates the idea that the system of NO generation is a newly discovered stress-limiting system. The action of this NO-ergic system is based on the capability of NO to limit key links of the stress reaction and to enhance the potency of endogenous defense systems of the organism. The role of NO is considered at the major stages of adaptation: 1) at the urgent stage related with the stress reaction; 2) at the stage of the transition from urgent to long-term adaptation; and 3) at the stage of long-term adaptation characterized by the formation of stable protective effects. It is demonstrated that pharmacological "imitation" of the activated NO-ergic system by administration of NO donors to the organism provides in many instances an efficient protection against stress damage and enhances the adaptive capacity of the organism.     

Use of heat emitted by broken optic fibers: A new approach for damage detection in composites

Optic fibers, stripped of their jacket, weakened and embedded in a composite plate structure, cracked due to the occurrence of cracks and delaminations in the composite. At the location of a crack in a fiber, transmitted laser-light energy was converted into thermal energy, causing the temperature in the neighborhood of the crack to rise. The temperature change was detected with the aid of an infrared camera. Dynamic numerical simulations of the heat development in the vicinity of the fiber crack were performed. An analytical solution of the temperature distribution on the surface of the composite plate above a fiber crack was also developed. Both analytical and numerical results showed the feasibility of detecting and monitoring the hot spot on the composite plate caused by optic fiber cracking, by use of infrared emission from the fibers. This was successfully confirmed in experiment. The influence of parameters such as depth of the fiber below the surface of the plate, heat conductivity coefficient and light power, on the temperature distribution was also studied. Ultrasound scan of the damaged plate confirmed the accuracy of the hot-spot method in defining the damaged area.     

Telomerase activity and its clinicopathological significance in gastric cancer

In order to assess the role of telomerase in development of malignant gastric cancer, we measured the telomerase activity in gastric cancer tissues and normal tissues obtained from 95 patients by employing recently developed sensitive PCR (polymerase chain reaction)-based telomerase assay (telomeric repeat amplification protocol, TRAP). We also investigated how telomerase activity related to other clinicopathological findings including DNA ploidy and K-RAS gene point mutation. The telomerase activity was present in 85 of the 95 gastric cancer tissues, whereas we detected no telomerase activity in any normal tissue. The incidence of telomerase activity in gastric cancer tissues was not correlated to age, sex, tumour stage, histological grade, DNA ploidy or K-RAS mutation. Disease-free or overall survival of patients having tumours with detectable telomerase activity was not significantly different from that of those without telomerase activity. These findings suggest that telomerase may play a key role in the establishment and progression of the gastric cancer and further studies will be needed to elucidate the biological role of telomerase in gastric cancer.