A CMOS multichannel 10-Gb/s transceiver

We describe a CMOS multichannel transceiver that transmits and receives 10 Gb/s per channel over balanced copper media. The transceiver consists of two identical 10-Gb/s modules. Each module operates off a single 1.2-V supply and has a single 5-GHz phase-locked loop to supply a reference clock to two transmitter (Tx) channels and two receiver (Rx) channels. To track the input-signal phase, the Rx channel has a clock recovery unit (CRU), which uses a phase-interpolator-based timing generator and digital loop filter. The CRU can adjust the recovered clock phase with a resolution of 1.56 ps. Two sets of two-channel transceiver units were fabricated in 0.11-/spl mu/m CMOS on a single test chip. The transceiver unit size was 1.6 mm /spl times/ 2.6 mm. The Rx sensitivity was 120-mVp-p differential with a 70-ps phase margin for a common-mode voltage ranging from 0.6 to 1.0 V. The evaluated jitter tolerance curve met the OC-192 specification.     

Eosinophil chemotaxis induced by several biologically active substances and the effects of apafant on it in vitro

Chemotaxis of guinea pig eosinophils induced by various stimuli in use of a modified Boyden chamber technique in vitro and the effect of a platelet-activating factor (PAF) antagonist, apafant (CAS 105219-56-5, WEB 2086 BS), on it were examined. The eosinophils were obtained by bronchoalveolar lavage from the animals treated by i.v. injection with Sephadex G-200 and purified by Percoll density gradient centrifugation. PAF significantly and potently induced the chemotaxis at a broad range of 10(-17) to 10(-7) mol/l, where no concentration-dependency was observed. Leukotriene B4 also induced the chemotaxis in a concentration-dependent manner at 10(-14) to 10(-12) mol/l and the enhanced migration was not declined until 10(-7) mol/l. Interleukin-5 (IL-5), IL-8 and regulated on activation normal T expressed and secreted (RANTES) only modestly enhanced the chemotaxis in some concentrations at 10(-13) to 10(-7) mol/l with or without significance and with no concentration-dependency while formyl-methionyl-leucyl-phenylalanine (FMLP), a known chemoattractant, increased the migration at 10(-7) to 10(-5) mol/l. Apafant at 10(-8) to 10(-6) mol/l strongly and concentration-dependently inhibited 10(-8) mol/l PAF-induced chemotaxis. However, the drug showed nominal or no influences on their chemotaxis stimulated by the other agonists, at the concentrations of which the enhanced migration was observed. From these results, it is concluded that IL-5, IL-8 and RANTES, different from PAF and LTB4, are not potent stimuli for the eosinophil chemotaxis and that apafant is a selective antagonist of PAF, which is expected to be therapeutically effective for PAF-associated diseases including bronchial asthma.     

KGa-priderite and related compound for the selective reduction of nitrogen monoxide with propylene

The catalytic activity of KGa-priderite, K_1.6Ga_1.6Ti_6.4O₁₆, and its related compound KGa₈Ga₉Ti₁₅O₅₆ was investigated for the selective reduction of nitrogen monoxide (NO) with propylene (C₃H₆) in the presence of high oxygen concentrations. The KGa-priderite showed significant activity during this reaction, but the related compound showed only a little activity. These compounds are quite different from the conventional catalysts for NO_x selective reduction and are characterized by the fact that their properties are free from the effects of solid acidity and support metals. This difference was attributable to the NO desorption rate at the surface of these compounds. It has become clear that the KGa-priderite catalyst remarkably adsorbed NO, and it is suggested that the amount of NO adsorbed and the amount of catalytic activity are able to be increased by the design of priderite structure.     

Physical and functional association of cortactin with Syk in human leukemic cell line K562

Human leukemic cell line K562 is induced to differentiate into the megakaryocytic lineage by stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA). We demonstrate here that TPA stimulation increases tyrosine phosphorylation of an 80-kDa protein at an early stage of megakaryocytic differentiation and that this 80-kDa protein is identical with cortactin. Since tyrosine kinase Syk was activated by TPA stimulation, we examined the possibility that cortactin is a potential substrate of Syk in K562 cells. TPA-induced tyrosine phosphorylation of cortactin was decreased profoundly by overexpression of dominant-negative Syk. Furthermore, cortactin was associated with Syk even before TPA stimulation. Since cortactin was previously referred as an 80/85-kilodalton pp60src substrate, we examined the association between Src and cortactin, whereas its association could not be detected. These data suggest that Syk phosphorylates cortactin in K562 cells upon TPA treatment.     

A broadband power meter calibration system in the frequency rangefrom 10 MHz to 40 GHz using a coaxial calorimeter

A broadband power meter calibration system based on a newly constructed coaxial calorimeter has been developed in the frequency region 10 MHz-40 GHz. The RF power is measured as the difference of DC power supplied to the calorimeter built-in heater in the RF load, when RF is turned off and on, holding an isothermal control between the RF load and a temperature reference. To minimize the error due to the adiabatic coaxial waveguide, we devised a new method utilizing its output port as a test port. The evaluations showed a calibration uncertainty of (0.28-2.2)% expressed by one standard deviation at the 1 mW level in the full band     

An entropy model for shear deformation of granular materials

A statistical mechanical analogy for characterization of granular materials is discussed by using such notions as the state of the material, the density of states, entropy, canonical distribution and the partition function. The transition law of states during shear deformations of the material is microscopically investigated in the case of two-dimensional model granular materials. The assumption of entropy growth is shown to characterize the dilatancy of the material. A rough proof is given by assuming the measure preserving property of the transition and showing its ergodicity.     

Cooperative behavior of various agents in dynamic environment

The multi-agent model is a model in which agents with limited ability cooperate each other to accomplish a goal. In this paper, we introduce a multi-agent model in which agents are created to imitate real ants. There are two different type of agents, each type of which has a particular task. We designed agents to communicate each other by using pheromone considering noise. On this model, we observed cooperative behavior of agents and evaluated conditions to make an order of behavior in the model.     

Generation of monoclonal antibodies to the rabbit interleukin-2 receptor alpha chain (CD25) and its distribution in HTLV-1-transformed rabbit T cells

Rabbits can be infected with human retroviruses such as human T-cell leukemia virus-1 (HTLV-1) and human immunodeficiency virus (HIV), and provide useful animal models to study retroviral diseases such as adult T-cell leukemia and HIV. Previously we have succeeded in generating monoclonal antibodies (mAbs) against rabbit CD4, CD5 and CD11a antigens. To make this animal species more amenable to cellular and molecular studies, we have attempted to extend the panel of mAbs against rabbit CD antigens. Here we report on the generation of three neutralizing mAbs against interleukin-2 receptor alpha chain (IL-2R alpha) (CD25), Kei-alpha 1 (IgG2b), Kei-alpha 2 (IgG2a) and Kei-alpha 3 (IgG1). They specifically recognize the rabbit Mr 55,000 IL-2 binding protein, IL-2R alpha, and completely inhibit both high- and low-affinity IL-2 binding to F648b cells that express IL-2R alpha as well as IL-2R beta. The use of mAb Kei-alpha 1 confirmed that the rabbit IL-2R alpha is not only a low-affinity IL-2R on its own but also an essential component of high-affinity IL-2R as found in other animal species, and that rabbit activated T cells including HTLV-1-transformed cell lines express high levels of the IL-2R alpha. Together with mAbs against various rabbit CD antigens that we reported previously, these neutralizing mAbs to IL-2R alpha will be valuable for studies of human retrovirus infections, such as those induced by HTLV-1 or HIV, in rabbits.