Morphology dependent field emission of acid-spun carbon nanotube fibers.

Acid spun carbon nanotube (CNT) fibers were investigated for their field emission properties and performance was determined to be dependent on fiber morphology. The fibers were fabricated by wet-spinning of pre-made CNTs. Fiber morphology was controlled by a fabrication method and processing conditions, as well as purity, size, and type of the CNT starting material. The internal fiber structure consisted of CNT fibrils held together by van der Waals forces. Alignment and packing density of the CNTs affects the fiber's electrical and thermal conductivity. Fibers with similar diameters and differing morphology were compared, and those composed of the most densely packed and well aligned CNTs were the best field emitters as exhibited by a lower turn-on voltage and a larger field enhancement factor. Fibers with higher electrical and thermal conductivity demonstrated higher maximum current before failure and longer lifetimes. A stable emission current at 3 mA was obtained for 10 h at a field strength of <1 V µm(-1). This stable high current operation makes these CNT fibers excellent candidates for use as low voltage electron sources for vacuum electronic devices.

Climate change and impacts in the Eastern Mediterranean and the Middle East.

The Eastern Mediterranean and the Middle East (EMME) are likely to be greatly affected by climate change, associated with increases in the frequency and intensity of droughts and hot weather conditions. Since the region is diverse and extreme climate conditions already common, the impacts will be disproportional. We have analyzed long-term meteorological datasets along with regional climate model projections for the 21st century, based on the intermediate IPCC SRES scenario A1B. This suggests a continual, gradual and relatively strong warming of about 3.5-7°C between the 1961-1990 reference period and the period 2070-2099. Daytime maximum temperatures appear to increase most rapidly in the northern part of the region, i.e. the Balkan Peninsula and Turkey. Hot summer conditions that rarely occurred in the reference period may become the norm by the middle and the end of the 21st century. Projected precipitation changes are quite variable. Annual precipitation is expected to decrease in the southern Europe - Turkey region and the Levant, whereas in the Arabian Gulf area it may increase. In the former region rainfall is actually expected to increase in winter, while decreasing in spring and summer, with a substantial increase of the number of days without rainfall. Anticipated regional impacts of climate change include heat stress, associated with poor air quality in the urban environment, and increasing scarcity of fresh water in the Levant.

[A morphological study of regeneration of the goldfish elasmoid scales].

Studies were carried out on the model of regeneration of mechanically removed elasmoid scales. Regenerating scales were morphologically analyzed using light and electron microscopy. It was found that the cells responsible for regeneration of the elasmoid scale plates could be classified as osteogenic elements. Little differentiated preosteoblasts were detected in the connective tissue of dermis on day 3 of regeneration, while partially calcified plates underlaid osteoblasts on day 7. The scale cover was fully restored on day 14 and it took two days for each bone plate to be formed. Osteocytes, fully differentiated osteogenic elements, were found in the deepest regions of newly formed scales.

Effect of synthetic peptide thrombin receptor agonist encapsulated in microparticles based on lactic and glycolic acid copolymer on healing of experimental skin wounds in mice.

PAR1 peptide thrombin receptor agonist (PAR1-AP) was encapsulated in microcorpuscles based on lactic and glycolic acid copolymer. The desorption profile of the preparation was studied in vitro and its wound-healing effects were studied on a model of cut skin wound in mice. The study showed that 90% PAR1-AP was desorbed over 6 h, but the peptide was detected in eluates from the microparticle surface after 23 h. The desorbed peptide retained its physiological activity and was capable of activating PAR1 receptors on human platelets. The study of the dynamics of experimental skin wound healing in mice showed lower number of macrophages in the wounds treated with PAR1-AP microparticles compared to the control (open wounds and wounds covered with microparticles) and higher number of fibroblasts on day 3 of tissue reparation. Hence, PAR1-AP desorbed from microparticles shortened the inflammation phase in the wound. On day 7 the best healing parameters were also observed in wounds treated with PAR1-AP microparticles, which attests to shortening of the proliferation phase and acceleration of wound healing.

[Polymer coatings with immobilized thrombin and peptides: preparation and use for wound healing]. / Polimernye pokrytiia s immobilizovannymi v nikh trombinom ili peptidami: poluchenie i primenenie dlia ranozazhivleniia.

Polymer dressings with encapsulated thrombin or synthetic peptides which can mimic thrombin action are employed for wound healing. Paper describes the method for preparation of these hydrogel composites of PVCL-CaAlg [poly(N-vinyl caprolactam-calcium alginate). The effect of encapsulated thrombin/peptides on tissue repair process have beet investigatat in vivo experiments using a mouse model of wound healing. The developed dressings accelerated wound healing: thascan be used as a basis for creation of novel formulations with controlled drug release for wound therapy.

"If you do not gamble, check this box": perceptions of gambling behaviors.

Most adults in the U.S. have participated in one or more gambling activities. However, many people engage in gambling activities without considering themselves as gamblers. Four hundred and forty-nine university students returned surveys about their participation in gambling activities. After completing a questionnaire recording the style and frequency of gambling participated in, respondents were asked to indicate whether or not they gambled. Results indicated that gamblers participated in twice as many forms of gambling activities as those who classified themselves as non-gamblers. Scratch tickets and lottery tickets were not generally considered gambling unless purchased frequently. Casino visits, bingo, dog races, football pools, golf matches, local poker games, and other card games were more likely to be viewed as gambling, especially when engaged in frequently. Subjects who had gambled on at least one occasion with bookies, dice games, video poker in a bar, dog or cock fights, or off track betting almost always identified themselves as gamblers. It is recommended that further research be conducted to clarify the gambling activities, and frequency of those activities, that influence a person's perceptions of gambling.

[Localization of hematopoietic tissue in sturgeon]. / Issledovanie lokalizatsii krovetvornoi tkani u osetrovykh ryb.

Morphological and autoradiographic studies on various hemopoietic tissues in sturgeon are presented. The classic hemopoietic organs characteristic of lower vertebrates, such as the kidney and spleen, are studied, as well as unique hemopoietic structures described only in the evolutionarily most ancient fish species (hemopoietic tissues of cartilaginous skull capsules and epicardium). The intensity of cell divisions in hemopoietic foci has been characterized by autoradiography. The results obtained provide a basis for the revision of traditional views about the phylogeny of hemopoiesis. They provide evidence that the osteogenic gravitation of hemopoietic tissue shows up in evolution alongside the appearance of the inner skeleton.

[Effect of x-irradiation on amoebocytopoiesis in the snail]. / Issledovanie vliianiia rentgenovskogo oblucheniia na amebotsitopoéz u vingradnoi ulitki.

The [3H]thymidine radioautography technique was used to study the objective laws of the renewal of blood cells (amoebocytes) of the edible snail (Helix pomatia) after X-radiation. Cells which are the precursors of amoebocytes actively proliferating beyond the limits of peripheral blood have been shown to possess a high radiosensitivity. The action of lethal doses of radiation (200-500 Gr) suppresses their proliferation and leads to the irreversible amoebocytopenia. Radioresistant cells lost the ability to the proliferation circulate in the peripheral blood.

[Origin of fibroblasts and macrophages of skin wound granulation tissue]. / O proiskhozhdenii fibroblastov i makrofagov granuliatsionnoi tkani kozhnykh ran.

By the method of thymidine autoradiography and fluorescing antibodies, the origin of cells participating in healing the experimentally produced wounds was investigated. 3H-thymidine was administered a day before the production of the wounds. 14C-thymidine was injected impulsively 1 h before the material was fixed 1,3 and 8 days after the trauma. The analysis of the autographs demonstrated that during wound healing the cell-precursors of macrophages and fibroblasts migrate from beyond the limits of the connective tissue. By means of the fluorescing antibodies in mouse radiation xenogenic chimaeras it was demonstrated that macrophages and fibroblasts participating in wound healing take their origin from the donor's elements, that is, are of bone marrow origin.

[Electron-microscopic and autoradiographic study of giant cells of foreign bodies in the focus of aseptic inflammation]. / Elektronno-mikroskopicheskoe i radioavtograficheskoe issledovanie gigantskikh kletok inorodnykh tel ochaga asepticheskogo vospaleniia.

Ultrastructure of sinuous proximal and straight distal tubules, as well as collecting tubules of the cortical layer in the rat kidney fixed with perfusion has been studied with electron microscopic morphometry 7--8 weeks after contralateral nephrectomy. The volume of mitochondria, the area of their crists, the area of the membranes in intracellular labyrinth and other morphometrical parameters have been calculated. Relative volume of mitochondria in the nephron areas studied does not change, while in the collecting tubules it is elevated. The area of crists in mitochondria and "coefficient of morphological organization level" of these organells in the proximal tubules are increased, in the distal do not change, in the collecting tubules increase again. Subcellular changes described are discussed mainly in terms of enhancement of concentrating function of the compensatory-hypertrophic kidney.