Large-area synthesis of carbon nanofibres at room temperature.

Carbon nanotubes, first identified by Iijima, require for their production a source of elemental carbon and a transfer of energy that is specific to the type of source and the growth environment. Methods developed so far involve arc discharge, and vaporization using laser, pyrolysis and chemical vapour deposition of hydrocarbons. Here, we show growth of carbon nanofibres from radio-frequency plasma-enhanced chemical vapour deposition at room temperature, which was made possible by substituting the thermal energy requirements for the growth with plasma decomposition of methane on the Ni catalyst. Electron microscopy analysis provides evidence for a 'tip' growth model, with the Ni catalyst particle attached to the tip of the nanofibre. Energy-filtered imaging shows the Ni catalyst has a surface layer rich in carbon, consistent with the formation of a eutectic Ni-C droplet as a nucleation site for the carbon nanofibres, so that the carbon diffuses across the surface. The reduced distortion of the catalyst particles at low temperatures leads to a more uniform growth of the carbon nanofibres over large areas. The lower growth temperature allows for the removal of the silicon dioxide barrier layer associated with catalytic growth, and should allow in situ growth of nanofibres on relatively large areas of temperature-sensitive substrates, such as plastics, organics and even paper.

Biochemical markers in ovarian cancer.

Fucose and sialic acid were measured in 41 patients with malignant ovarian tumors and in 25 patients with benign tumors. Supplementary, serial determinations done in 20 patients, with advanced ovarian cancer subjected to primary or secondary surgery (optimal tumor debulking) and subsequent chemotherapy enables to suggest the possibility to use these parameters as markers in monitoring ovarian cancer evolution and treatment.

Autodigestion of chromatin in some radiosensitive and radioresistant mouse cells. Role of proteolysis and endonucleolysis.

Evidence is presented indicating that mouse thymus, spleen, kidney, lung and heart contain a protease activity with relatively high specificity for histones. It is suggested that degradation of chromatin occurring in irradiated lymphoid tissues is produced by the action of alkaline endonuclease in association with this histone protease. The autodigestion of chromatin was assessed by determining the release of soluble chromatin from cells suspended in sucrose media of low ionic strength. It was found that the protease inhibitors, phenylmethylsulphonyl fluoride and especially NaHSO3, were also capable of depressing the activity of alkaline endonuclease, the fragmentation of chromatin, and the release of soluble chromatin. The results suggest that the release of histones from irradiated lymphoid tissues cannot be considered as a determinant step in the fragmentation of DNA in chromatin.

Significance of serum fucose, sialic acid, haptoglobine and phospholipids levels in the evolution and treatment of breast cancer.

Serum fucose, sialic acid, haptoglobine and phospholipids were determined in 167 women with breast cancer stages I--III, 30 with benign lesions of the breast, 42 women in various physiological states of the mammary gland (pregnancy, early childbed and lactation) and compared with 30 healthy women as control. Serial determinations of these parameters during the radio-surgical treatment were done in 28 patients with breast cancer stage III. Fucose and phospholipids levels were significantly increased respectively decreased in the group of patients with breast cancers but unmodified in the others. Sialic acid and haptoglobine -- increased in patients with cancer -- were also elevated in patients with early childbed and benign affections of the breast. The surveillance of these four parameters during the radio-surgical treatment of breast cancer evidenced a good correlation between their modified levels and clinical state of the patients. The increase in fucose, sialic acid and haptoglobine respectively the decrease in phospholipids levels was associated with the clinical evidence of recurrences and metastases.

Differences in uptake of aminoacids by patients with various forms of cancer.

The serum concentrations of alphaaminonitrogen (AAN), lysine, valine and leucines were determined before and within the period of 24 hr after the administration of Trophysan (10% solution of glucose containing a mixture of aminoacids) in 100 patients with cancer (17 with gastrointestinal carcinoma, 34 with uterus carcinoma, stages I to III; 8 with breast carcinoma, stages II and III; 15 with bronchogenic carcinoma, 10 with various localizations and 15 with metastatic cancer) and in 22 patients with benign tumors. A significant decrease in the serum content of AAN, valine and lysine was noted in patients with cancer (stages I to III) at 24 hours after the administration of Trophysan. This effect was absent for the patients with benign tumors. The enhanced uptake of aminoacids found in patients with cancer is probable the result of the negative nitrogen balance associated with the malignant state.

Participation of epsilonADP and epsilonATp in the reactions of oxidative phosphorylation in rat liver mitochondria.

The 1,N6-ethenoadenine nucleotide analogs epsilonADP and epsilonATP, contrary to recent findings (1), are shown to be unable to penetrate the inner mitochondrial membrane of intact rat liver mitochondria and can not be used as substrates by the respiratory chain enzymes in oxidative phosphorylation. On the other hand, these analogs are able to participate in transphosphorylation reactions, being good substrates for mitochondrial phosphotransferases located in the intermembrane space, such as nucleosidediphosphate kinase and adenylate kinase.