Extraction of magnetic circular dichroism effects from blended mixture of magnetic linear dichroism signals in the cobalt/Scotch tape system.

Circular dichroism (CD) signals revealed in some materials may arise from different origins during measurements. Magnetic field dependent CD (MCD) emanating from the spin-polarized band provides direct insight into the spin-spin interband transitions in magnetic materials. On the contrary, natural CD effects which are artefactual signals resulting from the linear polarization (LP) components during the polarization modulation with a photo-elastic modulator in anisotropic polymer systems were usually observed. There is no simple method to reliably distinguish MCD effect due to spin polarized band structures from natural CD effect, which limits our understanding of the magnetic material/polymer hybrid structures. This paper aims to introduce a general strategy of averaging out the magnetic linear dichroism (MLD) contributions due to the anisotropic structure and disentangling MCD signal(s) from natural MCD signal(s). We demonstrate the effectiveness of separating MCD from natural MCD using rotational MCD measurement and presented the results of a sample with Co thin film on polymer Scotch tape (unplasticized polyvinyl chloride) glued on a quartz substrate. We demonstrate that the proposed method can be used as an effective tool in disentangling MCD and natural MCD effects, and it opens prospects to study the magnetic material /polymer hybrid systems.

[Hypoxia in malignant tumors the target for clostridial therapeutic gene strategies]. / Hipoksja w nowotworach zlosliwych celem klostridialnych genowych strategii terapeutycznych.

In the fast proliferating malignant tumors which are characterized by abnormal vascularisation develop non oxidized regions of a low oxygen partial pressure (pO2). Because these tumors are unsusceptible to a conventional therapy they were chosen for clostridial therapeutic gene strategies. There were presented different strategies using clostridia as selective vectors of destructive genes, e.g. cytosine deaminase and nitroreductase activating in reduced microenvironment of tumors--nonactive prodrugs towards strong cytostatics, destroying hypoxic tumor cells. In general, they form a basis for CDEPT strategy (clostridial-directed enzyme prodrug therapy) and moreover in connection with antivessel cytostatic they form COBALT strategy (combination bacteriolytic therapy). In another strategy genetically modified clostridia are transferred to the gene of TNF alpha cytokine which production regulates fractionated ionizing radiation activating a promoter include in the clostridial vector. Sat last, there were discussed new problems connected with clostridial therapeutic gene strategies.

[Clostridium infections in leukemias and malignant neoplasms]. / Zakazenia beztlenowcami z rodzaju Clostridium w bialaczkach i nowotworach zlosliwych.

This review describes the subject of clostridial complications in leukemia and malignant neoplasms. These complications include bacteremia and spontaneous nontraumatic gas gangrene of the muscles. The mechanism of anaerobic microenvironment formation, which is necessary for infection development in neoplastic tumors, is also demonstrated. The role of risk factors contributing to the occurrence of clostridial infections is discussed. Further, the etiology of infections, related mostly to the action of Clostridium septicum and Clostridium perfringens toxins, as well as the pathogenesis of complications and their clinical course are indicated. Present treatment strategies are also briefly described.