Выделение и характеристика митохондриальной ДНК-топоизомеразы I типа из проростков кукурузы (Zea mays)

Проведена очистка и изучены биохимические характеристики ДНК-топоизомеразы типа I из митохондрий проростков кукурузы. Установлено, что фермент проявляет свойства, характерные для ДНК-топоизомераз как эукариотического, так и прокариотического происхождения.Здійснено очистку та вивчено біохімічні характеристики ДНК-топоізомерази типу 1 з мітохондрій проростків кукурудзи. Встановлено, що згаданий фермент виявляє властивості, характерні для ДНК-топоізомераз як еукаріотичного, так і прокаріотичного походження.The type I DNA-topoisomerase has been isolated and purified by procedures of salting out and ion chromatography from maize seedling mitochondria. It has been found that the enzyme examined possesses properties characteristic of DNA-topoisomerases of both eukaryotic and prokaryotic origin

Characterisation of the Gradient Coatings TiN/(Ti,Al,Si)N/TiN Type Deposited on Sintered Tool Materials

The paper presents results of the structural examinations, tests of mechanical and working properties ofthin wear resistant gradient coatings of the TiN/(Ti,Al,Si)N/TiN type, deposited in the CAE process ontothe substrate from the cermets and cemented carbides. Structural examinations are presented of theapplied coatings and their substrate made on the SEM, TEM and on the LM.Evaluation of the adhesion of the deposited coatings onto the cemented carbides and cermets was madeusing the scratch test. Cutting properties of the investigated materials were determined basing on thetechnological continuous cutting tests of the C45E steel. Substrate hardness tests and microhardness testsof the deposited coatings were made on the ultra-micro-hardness tester at 70 mN load. Surface roughnesstests were also made before depositing the coatings and after completing the PVD process

Regional Cortical Thinning Associated with Detectable Levels of HIV DNA

High levels of human immunodeficiency virus (HIV) DNA in peripheral blood mononuclear cells (PBMCs), and specifically within CD14+ blood monocytes, have been found in HIV-infected individuals with neurocognitive impairment and dementia. The failure of highly active antiretroviral therapy (HAART) to eliminate cognitive dysfunction in HIV may be secondary to persistence of HIV-infected PBMCs which cross the blood-brain barrier, leading to perivascular inflammation and neuronal injury. This study assessed brain cortical thickness relative to HIV DNA levels and identified, we believe for the first time, a neuroimaging correlate of detectable PBMC HIV DNA in subjects with undetectable HIV RNA. Cortical thickness was compared between age- and education-matched groups of older (>40 years) HIV-seropositive subjects on HAART who had detectable (N = 9) and undetectable (N = 10) PBMC HIV DNA. Statistical testing revealed highly significant (P < 0.001) cortical thinning associated with detectable HIV DNA. The largest regions affected were in bilateral insula, orbitofrontal and temporal cortices, right superior frontal cortex, and right caudal anterior cingulate. Cortical thinning correlated significantly with a measure of psychomotor speed. The areas of reduced cortical thickness are key nodes in cognitive and emotional processing networks and may be etiologically important in HIV-related neurological deficits