Abstract: An optical signal monitor circuit includes a PD which directly detects an optical signal and converts the optical signal into a photocurrent, and another PD which detects the optical signal and converts the optical signal into a photocurrent. A resistance element converts the photocurrents into voltages for input to an operational amplifier which outputs voltages based on the voltages generated by the resistance element. A switching control circuit switches a connection between the PDs and the resistance element, and a calculation circuit acquires the output of the operational amplifier converted to digital signals such that the switching control circuit controls switching to cause the two photocurrents to flow into the resistance element at individual timings and to cause the two photocurrents to flow into the resistance element at the same timing, and the calculation circuit calculates a corrected digital signal by subtracting with the obtained digital signals.

Abstract: An amplifier includes a differential amplifier and a compensator. A differential amplifier includes a current source and paired transistors. The paired transistors generate an output signal by dividing a source current supplied by the current source into emitter currents of the paired transistors in response to a difference between an input signal and a reference signal. A compensator includes an amplifying transistor and a feedback circuit that feeds a collector current output from a collector of the amplifying transistor back to a base of the amplifying transistor therethrough. The compensator generates the reference signal at a base of the amplifying transistor. The compensator decreases power consumption of the amplifying transistor when the collector current increases, and increases the power consumption of the amplifying transistor when the collector current decreases. The compensator suppresses a peaking of gain in a low frequency band.

Abstract: A method evaluates the mobility of a polymer composition in a high-temperature region of 150° C. or above. The method for evaluating a physical property of a polymer composition, the method comprising the steps of: obtaining a thin film sample which is formed on a substrate and which comprises: a fluorescent probe including a fluorescent rare earth complex having a melting point of 200° C. or higher; and a target polymer composition; and obtaining a relationship between a temperature and a fluorescent characteristic of the thin film.

Abstract: A differential amplifier includes an amplifying stage that outputs an output signal by amplifying an input signal with a gain set by a control signal, and an adjusting stage that stabilizes a DC level of the output signal. The amplifying stage includes a first source supplying a first current, and a load, and determines a ratio of a current flowing through the load to the first current depending on the input signal and the control signal, and generates the output signal from a voltage drop of the load. The adjusting stage includes a second source supplying a second current, and a monitor resistor, and generates a monitor current divided from the second current by the ratio, and duplicates the DC level as a voltage drop of the monitor resistor caused by the monitor current, and controls the first current source and the second current source depending on the DC level.

Abstract: An amplifier circuit has: a main amplifier connected between an input terminal and an output terminal, the main amplifier amplifying an input signal input to the input terminal and outputting an amplified signal to the output terminal; a compensation circuit comprising a variable delay circuit and a variable gain inverting circuit, the variable delay circuit receiving the input signal and outputting a delay signal with a delay time from the input signal, the variable gain inverting circuit inverting and amplifying the delay signal with a gain and outputting a compensation signal to the output terminal; and a controller configured to control the gain of the variable gain inverting circuit and the delay time of the variable delay circuit to compensate a response of the main amplifier in a first frequency of a target signal of compensation and in a low frequency band higher than zero Hertz.

Abstract: A pulse amplitude modulation (PAM) signal generator is disclosed. The PAM signal generator, which is applicable to a vertical cavity surface emitting laser diode (VCSEL), provides a plurality of differential units each having two outputs complementary to each other and biased by a power supply voltage through the commonly connected VCSEL and a dummy diode. The differential units have respective current sources each, where partial sums and a total sum of the currents correspond to the multiple output levels of the VCSEL. The PAM signal generator also provides compensating units to compensate the saturation (non-linearity) of the optical output of the VCSEL.

Abstract: A laser driver to provide a shunt current to a laser diode is disclosed. The laser driver includes a first generator to generate a first signal in response to an input signal and a second signal generator to generate a second signal in response to the input signal. The first signal has first amplitude and a first rising transition that switches the laser diode from an ON state to an OFF state of the laser diode. The second signal has second amplitude smaller than the first amplitude and a second rising transition having a delay from the first rising transition. The laser driver further includes an output terminal to output the shunt current including the first signal and the second signal.

Abstract: An optical receiver with an expanded dynamic range for an input current is disclosed. The optical receiver includes a photodiode to generate a photocurrent, a trans-impedance amplifier (TIA) to convert the photocurrent into a voltage signal, a dummy TIA with an arrangement same with those of the TIA to generate a reference, a differential amplifier to amplify a difference between the voltage signal and the reference, a current source to extract a portion of the photocurrent, and a level detector to detect an average photocurrent and adjust the reference based on the average photocurrent.

Abstract: A calcium complex grease composition is disclosed. The grease composition has a high dropping point and a suitable thickness and is stable to heat.

Abstract: A biomolecule-compatible highly branched polymer obtained by polymerizing a monomer having an alkylene oxide and two or more radically polymerizable double bonds in a molecule in presence of a polymerization initiator in 5 mol % or more and 200 mol % or less relative to the moles of monomer, wherein molecular terminals of biomolecule-compatible highly branched polymer have one biomolecular site of at least one pair from the group of combination pairs of biotin and avidin, an antigen and antibody, polynucleotide and polynucleotide having complementary base sequence thereof, cDNA and mRNA, enzyme and substrate, an enzyme and product, an enzyme and competitive inhibitor, an enzyme (binding site) and coenzyme, an enzyme (binding site) and triazine dye, protease and protease inhibitor, Fc site and protein A, Fc site and protein G, lectin and sugar, hormone receptor and hormone, DNA and DNA binding protein, heparin and fibronectin, and heparin and laminin.

Abstract: A differential amplifier with cascade transistors connected in series to switching transistors is disclosed. The base bias of the cascade transistors is set higher than the output LOW level of the cascade transistors by a preset amount of 0.1 to 0.2V, or lower than the input HIGH level of the switching transistors by the preset amount adding to a forward voltage of a junction diode, to provide a discharge current of the base-emitter junction Cbe from the bias control, or from the upstream stage to drive the differential circuit.

Abstract: A grease composition comprising base oil and as thickener calcium complex soap and lithium soap is disclosed. A higher fatty acid, an aromatic monocarboxylic acid and a lower fatty acid are used as carboxylic acids constituting the calcium complex soap and lithium soap. The grease composition has a high dropping point and excellent shear stability, and exhibits thermal stability and long bearing life.

Abstract: A biomolecule-compatible highly branched polymer obtained by polymerizing a monomer having an alkylene oxide and two or more radically polymerizable double bonds in a molecule in presence of a polymerization initiator in 5 mol % or more and 200 mol % or less relative to the moles of monomer, wherein molecular terminals of biomolecule-compatible highly branched polymer have one biomolecular site of at least one pair from the group of combination pairs of biotin and avidin, an antigen and antibody, polynucleotide and polynucleotide having complementary base sequence thereof, cDNA and mRNA, enzyme and substrate, an enzyme and product, an enzyme and competitive inhibitor, an enzyme (binding site) and coenzyme, an enzyme (binding site) and triazine dye, protease and protease inhibitor, Fc site and protein A, Fc site and protein G, lectin and sugar, hormone receptor and hormone, DNA and DNA binding protein, heparin and fibronectin, and heparin and laminin.

Abstract: A transmitter module is disclosed, where the transmitter module includes optical sources, an optical multiplexer to multiple optical signals each output from optical sources, an optical detector to detect an output of the optical multiplexer, and a controller. The controller alternately superposes a dither signal on a bias current provided to the optical source, and the bias current is controlled based on a magnitude of the dither signal, which is detected by a configuration similar to the lock-in amplifier.

Abstract: A transmitter module is disclosed, where the transmitter module includes optical sources, an optical multiplexer to multiple optical signals each output from optical sources, an optical detector to detect an output of the optical multiplexer, and a controller. The controller alternately superposes a dither signal on a bias current provided to the optical source, and the bias current is controlled based on a magnitude of the dither signal, which is detected by a configuration similar to the lock-in amplifier.

Abstract: A transmitter optical module implemented with an electro-absorption (EA) modulator is disclosed. The module includes an EA driver comprising a signal detector, an offset controller, and a driver circuit. The signal detector detects the existence of the modulation signal input thereto. The offset controller provides to the driver circuit the first offset to shift the cross point of the output of the driver circuit higher when the modulation signal exists; while, the second offset when the modulation signal disappear. The second offset lowers the output of the driver circuit to prevent the excess optical output of the transmitter optical module.

Abstract: A grease composition for use in resin lubrication wherein at least one amine salt of an unsaturated or saturated fatty acid is incorporated in a grease base material which includes a base oil and a thickener, preferably wherein at least one fatty acid amine salt of the following general formula (1) is incorporated: RCOO? R? NH3+ wherein either (i) R is an unsaturated hydrocarbon group having from 15 to 21 carbon atoms, and R? is a saturated or unsaturated linear or branched hydrocarbon group having from 8 to 22 carbon atoms; or (ii) R is a linear saturated hydrocarbon group having from 5 to 21 carbon atoms, and R? is an unsaturated hydrocarbon group having from 16 to 18 carbon atoms. The grease composition of the present invention improves the lubricity between resin and resin or resin. and another material such as a metal.

Abstract: A semiconductor optical modulator includes optical input and output portions; a plurality of Mach-Zehnder modulators, each including first and second waveguide arms having first and second modulation electrodes, respectively; an optical demultiplexer coupled between the optical input portion and the Mach-Zehnder modulators through an optical waveguide; an optical multiplexer coupled between the optical output portion and the Mach-Zehnder modulators; a plurality of electrical inputs; and a plurality of differential transmission lines electrically connecting the electrical inputs to the Mach-Zehnder modulators. The first modulation electrode and the second modulation electrode of at least one of the Mach-Zehnder modulators, one of the electrical inputs, and one of the differential transmission lines that connects such one electrical input to such one Mach-Zehnder modulator form an electrical circuit having a differential impedance in a range of 80? to 95?.

Abstract: Protein ubiquitylation, an essential post-translational modification, regulates almost every cellular process including protein degradation, protein trafficking, signal transduction, and DNA damage response in eukaryotic cells. The diverse functions of ubiquitylation are thought to be mediated by distinct chain topologies resulting from eight different ubiquitin linkages, chain lengths, and complexities. Currently, ubiquitin linkages are generally thought to be a critical determinant of ubiquitin signaling. However, ubiquitin chain lengths, another key element of ubiquitin signaling, have not been well documented especially in vivo situation during past three decades from the discovery of ubiquitin. The reason of this was simply because no method has been available for determination of ubiquitin chain length in endogenous ubiquitylated substrates. In the present invention, a practical technique for determining the actual length of substrate-attached polyubiquitin chains from biological samples is established.

Abstract: The present invention relates to a process for producing a polymer structure comprising: mixing and unifying a matrix polymer made of a linear polymer and a highly-branched polymer having hydrophilic functional groups at molecular ends and to form a structure containing the matrix polymer and the highly-branched polymer; and subjecting the obtained structure to either immersion in water and/or a hydrophilic solvent or exposure to an atmosphere of vapor of water and/or a hydrophilic solvent at a temperature ranging from a temperature lower than Tg of the matrix polymer by 30° C. to decomposition temperature of the matrix polymer; wherein the hydrophilic functional groups at the molecular ends of the highly-branched polymer are distributed in outermost surface of the polymer structure at an enhanced density. The present invention also relates to a process for producing a polymer structure in which vinyl polymer chains are grafted to at least a part of the hydrophilic functional groups.