Abstract: A light emitting device includes a light emitting element emitting an excitation light and a fluorescent element. The fluorescent element includes a semi-translucent film facing the light emitting element, and transmits the excitation light; a first luminescent film including phosphors to absorb the excitation light transmitted through the semi-translucent film and to emit a visible light having a different wavelength than the excitation light; and a reflection film disposed on an opposite side of the first luminescent film on which the semi-translucent film is disposed, reflecting the excitation light transmitted through the first luminescent film towards the first luminescent film.

Abstract: A semiconductor device has an active layer, a first semiconductor layer of first conductive type, an overflow prevention layer disposed between the active layer and the first semiconductor layer, which is doped with impurities of first conductive type and which prevents overflow of electrons or holes, a second semiconductor layer of first conductive type disposed at least one of between the active layer and the overflow prevention layer and between the overflow prevention layer and the first semiconductor layer, and an impurity diffusion prevention layer disposed between the first semiconductor layer and the active layer, which has a band gap smaller than those of the overflow prevention layer, the first semiconductor layer and the second semiconductor layer and which prevents diffusion of impurities of first conductive type.

Abstract: A semiconductor device has an active layer, a first semiconductor layer of first conductive type, an overflow prevention layer disposed between the active layer and the first semiconductor layer, which is doped with impurities of first conductive type and which prevents overflow of electrons or holes, a second semiconductor layer of first conductive type disposed at least one of between the active layer and the overflow prevention layer and between the overflow prevention layer and the first semiconductor layer, and an impurity diffusion prevention layer disposed between the first semiconductor layer and the active layer, which has a band gap smaller than those of the overflow prevention layer, the first semiconductor layer and the second semiconductor layer and which prevents diffusion of impurities of first conductive type.

Abstract: A semiconductor substrate encompasses a GaN substrate and a single-crystal layer formed of III-V nitride compound semiconductor epitaxially grown on the GaN substrate. The GaN substrate has a surface orientation defined by an absolute value of an off-angle of the surface from {0001} plane towards <1-100> direction lying in a range of 0.12 degree to 0.35 degree and by an absolute value of an off-angle of the surface from {0001} plane towards <11-20> direction lying in a range of 0.00 degree to 0.06 degree.

Abstract: A semiconductor substrate encompasses a GaN substrate and a single-crystal layer formed of III-V nitride compound semiconductor epitaxially grown on the GaN substrate. The GaN substrate has a surface orientation defined by an absolute value of an off-angle of the surface from {0001} plane towards <1?100> direction lying in a range of 0.12 degree to 0.35 degree and by an absolute value of an off-angle of the surface from {0001} plane towards <11?20> direction lying in a range of 0.00 degree to 0.06 degree.

Abstract: A semiconductor device has an active layer, a first semiconductor layer of first conductive type, an overflow prevention layer disposed between the active layer and the first semiconductor layer, which is doped with impurities of first conductive type and which prevents overflow of electrons or holes, a second semiconductor layer of first conductive type disposed at least one of between the active layer and the overflow prevention layer and between the overflow prevention layer and the first semiconductor layer, and an impurity diffusion prevention layer disposed between the first semiconductor layer and the active layer, which has a band gap smaller than those of the overflow prevention layer, the first semiconductor layer and the second semiconductor layer and which prevents diffusion of impurities of first conductive type.

Abstract: A nitride semiconductor device comprises: a substrate body including a conductive substrate portion and a high resistance portion; a first semiconductor layer of a nitride semiconductor provided on the substrate body; a second semiconductor layer provided on the first semiconductor layer; a first main electrode provided on the second semiconductor layer; a second main electrode provided on the second semiconductor layer; and a control electrode provided on the second semiconductor layer between the first main electrode and the second main electrode. The second semiconductor layer is made of a nondoped or n-type nitride semiconductor having a wider bandgap than the first semiconductor layer. The first main electrode is provided above the conductive portion and the second main electrode is provided above the high resistance portion.

Abstract: Disclosed herein is a high-reliability semiconductor device. The laser diode includes: a substrate; a multi-layer film including a first conductivity type cladding layer provided on the substrate, a first conductivity type guide layer provided on the first conductivity type cladding layer, an active layer provided on the first conductivity type guide layer, a second conductivity type guide layer provided on the active layer, and a second conductivity type cladding layer provided on the second conductivity type guide layer, each of the layers being made of a nitride-based III-V group compound semiconductor; a first protective layer made of nitride and provided on a light emitting surface of the laser diode; and a second protective layer provided on the first protective layer and made of nitride having a refractive index different from that of the first protective layer.

Abstract: A semiconductor substrate encompasses a GaN substrate and a single-crystal layer formed of III-V nitride compound semiconductor epitaxially grown on the GaN substrate. The GaN substrate has a surface orientation defined by an absolute value of an off-angle of the surface from {0001} plane towards <1-100> direction lying in a range of 0.12 degree to 0.35 degree and by an absolute value of an off-angle of the surface from {0001} plane towards <11-20> direction lying in a range of 0.00 degree to 0.06 degree.

Abstract: Imidazole derivatives of the formula (1) or salts thereof, pharmaceuticals containing the derivatives or the salts, and intermediates for the synthesis of the derivatives or the salts (wherein R1 is lower alkyl; R2 is alkyl or aralkyl; and X1 is halogeno). These compounds exhibit G-CSF-like activities and can be substituted for G-CSF preparations.

Abstract: A method of detecting a ligand or a ligand-like low-molecular weight compound from among test compounds characterized by separating a ligand-dependent cell line having a ligand receptor gene and an antibiotic resistance gene transferred thereinto from other cell lines, culturing the cell line in the presence of the test compounds and then examining the proliferation ability of the cells. Use of this method makes it possible to exactly screen a ligand (a physiologically active substance) or a low-molecular weight compound having the same action by a simple procedure.

Abstract: Disclosed herein are an imidazole derivative represented by the following general formula (1): ##STR1## wherein R.sup.1 is a hydrogen atom, or an alkyl, alkoxy or alkoxycarbonyl group, and R.sup.2, R.sup.3 and R.sup.4 are the same or different from one another and are independently a hydrogen or halogen atom, an alkyl, halogenoalkyl, hydroxyl or alkoxy group, or the like, or a salt thereof, and a medicine comprising such a compound. The compound specifically suppresses the production of particular cytokine and is hence useful as an active ingredient for immune function modulators and the like.

Abstract: Described is a pyridine derivative represented by the following formula (1): ##STR1## wherein R.sup.1 and R.sup.2 individually represent H, an alkyl group, a cycloalkyl group, a hydroxyalkyl group, an alkoxyalkyl group which may have a substituent, a carboxyalkyl group, an alkoxycarbonylalkyl group, an aralkyl group which may have a substituent, a phenacyl group or an acyl group, R.sup.3 represents an alkyl group, a phenyl group which may have a substituent, a heteroaryl group or a cyclic amino group, X represents O or combination of OH and H, or a salt thereof; and a medicament, such as cytokine production suppressant, comprising the derivative or salt thereof as an effective ingredient. The invention compound has potential, highly specific and highly safe immunoregulating capacity so that it can suppress the excessive production of a specific cytokine in various diseases related to the immune system.

Abstract: Disclosed herein are substituted benzylurea derivatives represented by the following general formula (1): ##STR1## wherein R.sup.1 and R.sup.2 are independently H, a halogen atom, or an alkyl or alkoxyl group, R.sup.3 is a phenyl or heterocyclic group which may be substituted, n is an integer of 1-6, and R.sup.4 is a phenyl group which may be substituted, or salts thereof, and medicines comprising such a derivative as an active ingredient. The derivatives or salts thereof strongly inhibit only ACAT in macrophages and are hence useful as prophylactic and therapeutic agents for arteriosclerosis.

Abstract: Disclosed herein are substituted vinylurea derivatives represented by the following general formula (1): ##STR1## wherein R.sup.1 and R.sup.3 are independently a phenyl group which may be substituted, R.sup.2 is a phenyl group which may be substituted, or a cycloalkyl group, and wave lines mean that the bonding state may be either E or Z, with the proviso that the cases where R.sup.1, R.sup.2 and R.sup.3 are unsubstituted phenyl groups, and where R.sup.1 and R.sup.2 are unsubstituted phenyl groups and R.sup.3 is a 4-ethoxyphenyl group are excluded, or salt thereof, and medicines comprising such a derivative as an active ingredient as well as a method of preventing and treating arteriosclerosis with such a medicine. The derivatives or salts thereof selectively and strongly inhibit ACAT in macrophages and are hence useful as prophylactic and therapeutic agents for arteriosclerosis.

Abstract: An antiulcer drug comprising Ikarugamycin as its active ingredient is disclosed.