Abstract: A light-receiving element has a photodiode formed in part of the top surface of a semiconductor substrate so as to function as a light-receiving region, and has a light-emitting element mount electrode formed on top of the semiconductor substrate where the light-receiving region is not formed. A high concentration impurity layer is formed below the top surface of the semiconductor substrate along the peripheral edges of the light-emitting element mount electrode. This helps prevent the voltage applied to the light-emitting element mount electrode from influencing the output of the light-receiving element. Alternatively, a photonic semiconductor device has a light-emitting element and a light-receiving element, and has the light-receiving region of the light-receiving element formed parallel to the direction in which the light-emitting element emits light.

Abstract: A light-receiving device has a high-concentration impurity layer of a first conductivity type and a high-concentration impurity layer of a second conductivity type surrounding it formed on a substrate of the first conductivity type having a low impurity concentration so as to function as a light-receiving portion. The high-concentration impurity layers of the first and second conductivity types are arranged in the same direction as the top surface of the substrate. A layer having a short carrier life time is formed on the bottom surface of the substrate. Thus, carriers ascribable to unnecessary light components that have reached the layer having a short carrier life time have a shorter life time, making it possible to sufficiently cut unnecessary long-wavelength light components.

Abstract: A light-receiving element has a photodiode formed in part of the top surface of a semiconductor substrate so as to function as a light-receiving region, and has a light-emitting element mount electrode formed on top of the semiconductor substrate where the light-receiving region is not formed. A high concentration impurity layer is formed below the top surface of the semiconductor substrate along the peripheral edges of the light-emitting element mount electrode. This helps prevent the voltage applied to the light-emitting element mount electrode from influencing the output of the light-receiving element.

Abstract: A light-receiving device has a high-concentration impurity layer of a first conductivity type and a high-concentration impurity layer of a second conductivity type surrounding it formed on a substrate of the first conductivity type having a low impurity concentration so as to function as a light-receiving portion. The high-concentration impurity layers of the first and second conductivity types are arranged in the same direction as the top surface of the substrate. A layer having a short carrier life time is formed on the bottom surface of the substrate. Thus, carriers ascribable to unnecessary light components that have reached the layer having a short carrier life time have a shorter life time, making it possible to sufficiently cut unnecessary long-wavelength light components.

Abstract: A novel 2-piperidinecarboxylic acid derivative represented by the formula: ##STR1## wherein X represents an oxygen atom, a sulfur atom or a nitrogen atom to which a hydrogen atom is bound; and * represents that the configuration of the carbon atom binding to the carboxyl group is (S), (R) or a mixture of (S) and (R); and a pharmaceutically acceptable salt thereof which exerts an antitumor effect over a wide range of tumor cells.

Abstract: A light receiving device and a circuit device which includes an amplifier directly connected to the light receiving device are provided on a frame which is connected to a power source potential. The light receiving device and circuit device are integrally covered with resin. On electrodes through which the light receiving device and circuit device are connected to the frame, semiconductor substrates of the same conductivity type are provided, respectively.

Abstract: 7-Deazapurine derivatives of the formula: ##STR1## wherein R.sup.1 is phenyl which has, at the ortho position and/or para position as substituents, at least one group represented by the formula --O--R.sup.3, --S--R.sup.4 or ##STR2## (wherein R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are the same or different and each is hydrogen or an alkyl or phenyl group which may be substituted, whereby R.sup.5 and R.sup.6, together with the adjacent nitrogen atom, may form a cyclic amino group which may be substituted, and R.sup.3, R.sup.4, R.sup.5 and R.sup.6 each may represent a protective group), and may have a group or groups with a molecular weight of up to about 200 as a substituent at any position other than those having the said substituents introduced; R.sup.2 is an amino group which may be protected, or its salt, have a potent antitumor activity, and hence the compounds are useful as an antitumor agent.

Abstract: 7-Deazapurine derivatives of the formula: ##STR1## wherein R.sub.1 is hydrogen atom or an acyl group and R.sub.4 and R.sub.5 each is a hydrogen atom or a hydrocarbon residue which may optionally have one or more substituents or R.sub.4 and R.sub.5, together with the adjacent nitrogen atom, from a cyclic amino group are useful as an anti-tumor agent, microbicide or disinfectant.

Abstract: Novel deazapurine derivatives of the formula: ##STR1## wherein R.sup.1 is C.sub.1-18 alkyl which may be substituted with di-C.sub.1-3 alkyl amino; C.sub.1-18 alkenyl; C.sub.3-8 cyloalkyl; C.sub.5-8 cycloalkenyl; C.sub.7-13 aralkyl which may be substituted with C.sub.1-4 alkoxy, C.sub.1-4 alkanoyl, C.sub.2-4 alkoxycarbonyl, hydroxy, amino, nitro, trifluoromethyl or C.sub.1-4 alkanoylamido; or C.sub.6-10 aryl andR.sup.2 is hydrogen or C.sub.7-13 aralkyl or,R.sup.1 and R.sup.2, taken together with the adjacent nitrogen atom, form a piperidine ring, and salt thereof are selectively taken up by tumor cells and have antitumor activity.

Abstract: Novel 7-deazapurine derivatives of the formula: ##STR1## wherein X is halogen, Y is hydroxyl or di-C.sub.1-3 alkylamino, Z is a --NH-- or --NHC(.dbd.NH)-- group, l is an integer of 1 to 5, m is an integer of 0 to 2, and n is 1 when Z is a --NH-- group or n is 0 or 1 when Z is a --NHC(.dbd.NH)-- group, and salts thereof are selectively taken up by tumor cells.

Abstract: In a variable resistor of the type wherein there is formed on an insulating substrate a resistive member having wide portions and narrow portions in the sliding direction of a slide member and ends thereof wired respectively to a ground terminal and an input terminal. A plurality of contact elements formed on said slide member are brought into sliding contact with said resistive member and a high resistance film allowing the passage of electrostatic charges therethrough is formed at portions of said insulating substrate lying within the sliding passage of said contact elements so that a part of said contact elements comes into contact therewith when it comes off from said resistive member.