摘要:
A non-volatile semiconductor memory device and the fabricating method thereof, wherein control gates respectively formed at the active areas of the resultant structure for getting a corresponding pair of split floating gates continuously overlapped and buried diffusion areas formed at the substrate of the periphery of the field insulating layer positioned between neighboring source areas to prevent the source areas from being electrically disconnected by the field insulating layer, even if the floating gate pattern and the control gate pattern are respectively made by separate processes, so that there will be no mismatching between the aforementioned two patterns, thereby leading to no tendency of showing different characteristics of memory cells in accordance with odd/even numbered word lines, the schematic characteristic of cells makes it possible to program and erase a byte, and one contact hole is not used at each bit line, the number of contact holes gets small, thereby making it possible to scale down cells.
摘要:
Polysaccharides, which are widely used as an anticoagulation drugs, especially heparin, are clinically administered only by intravenous or subcutaneous injection because of their strong hydrophilicity and high negative charge. Amphiphilic heparin derivatives were synthesized by conjugate to bile acids, sterols, and alkanoic acids, respectively. The hydrophobicity of the heparin derivatives depended on the feed mole ratio of heparin to hydrophobic agent. The heparin derivatives were slightly hydrophobic and exhibited good solubility in a water-acetone solvent, as well as water. The heparin derivatives have a high anticoagulant activity. These slightly hydrophobic heparin derivatives can be absorbed in gastric intestinal tract and can be used as oral dosage form. Also, the heparin derivatives can be used for the surface modification to prevent anticoagulation for medical devices such as extracorporeal devices and implanted devices.