Powder containing 2H-type silicon carbide produced by reacting silicon dioxide and carbon powder in nitrogen atmosphere in the presence of aluminum

The production of powder which contains silicon carbide consisting of 40% of 2H-type silicon carbide, beta type silicon carbide and less than 3% of nitrogen is discussed. The reaction temperature to produce the powder containing 40% of 2H-type silicon carbide is set at above 1550 degrees C in an atmosphere of aluminum or aluminum compounds and nitrogen gas or an antioxidation atmosphere containing nitrogen gas. The mixture ratio of silicon dioxide and carbon powder is 0.55 - 1:2.0 and the contents of aluminum or aluminum compounds within silicon dioxide is less than 3% in weight

CELLULAR RECOGNITION BY MOUSE LYMPHOCYTES IN VITRO : I. DEFINITION OF A NEW TECHNIQUE AND RESULTS OF STIMULATION BY PHYTOHEMAGGLUTININ AND SPECIFIC ANTIGENS

The media and culture conditions required for in vitro stimulation of mouse lymphoid cells are described. The medium was arginine-rich and contained heat-inactivated human serum. A component of the human sera necessary for stimulation of the cells was a natural mouse cell agglutinin, which affected both background stimulation and the degree of induced stimulation with phytohemagglutinin (PHA). Absorption of the agglutinin from the human serum rendered the medium incapable of sustaining DNA synthesis in the presence of PHA. The response to PHA of mouse spleen and thymus cells was age-dependent and, although this response was not present at birth, it rapidly rose to adult levels. Spleen cells from mice immunized with bacillus Calmette-Guérin (BCG) or sheep erythrocytes (SRBC) showed increased in vitro reactivity to added purified protein derivative (PPD) or SRBC stroma, dependent on the time of immunization. The dose response curve for the SRBC stroma stimulated, immune spleen cells is compatible with a theory of cell to cell interaction being necessary for an in vitro reaction to antigen. The possible role of the mouse cell agglutinin (AMLG) is discussed

Controlling malignant pericardial effusion by intrapericardial carboplatin administration in patients with primaryon-small-cell lung cancer

Malignant pericarditis, when associated with massive pericardial effusion, presents a critical condition in lung cancer patients. Because this condition often arises in terminally ill patients, intensive therapy such as multi-drug combination chemotherapy is rarely appropriate. This study evaluated the clinical relevance of intrapericardial administration of carboplatin for controlling malignant pericardial effusions associated with non-small-cell lung carcinoma (NSCLC). The method used for 10 eligible patients consisted of draining the pericardial effusion and infusing 300 mg/body of carboplatin in 50 ml of saline through an in-place catheter into the pericardial space and clamping the catheter for 40 min. Nine of the 10 patients showed satisfactory results, and 8 experienced complete regression of the effusion. No major or minor adverse effects were observed. Pharmacokinetics analysis revealed that the concentration of free platinum in the pericardial fluid was very high while that of total platinum in the circulating plasma was very low, assuring the usefulness of the intrapericardial instillation of carboplatin in terminally ill patients for controlling malignant pericardial effusion when the systemic delivery of cytotoxic agents is inappropriate. © 2000 Cancer Research Campaig

Actively Contracting Bundles of Polar Filaments

We introduce a phenomenological model to study the properties of bundles of polar filaments which interact via active elements. The stability of the homogeneous state, the attractors of the dynamics in the unstable regime and the tensile stress generated in the bundle are discussed. We find that the interaction of parallel filaments can induce unstable behavior and is responsible for active contraction and tension in the bundle. Interaction between antiparallel filaments leads to filament sorting. Our model could apply to simple contractile structures in cells such as stress fibers.Comment: 4 pages, 4 figures, RevTex, to appear in Phys. Rev. Let