1,000 research outputs found

    Endocrinology: Clinical significance of invisible or partially visible luteinizing hormone

    Get PDF
    It is well known that luteinizing hormone (LH), like many other glycoproteins, is heterogeneous and presents several circulating isoforms. Recently, new sensitive immunometric assays measuring intact LH were developed. These assays have been found to underestimate or to be incapable of recognizing LH in some patients. This study was undertaken to determine the prevalence of such cases and to define their clinical characteristics. We compared three LH assays using as capture antibodies either a monoclonal antibody that reacts exclusively with intact LH (ES 600 Boehringer, Stratus Baxter) or a monoclonal antibody against the β subunit of LH (IMX Abbott). In 17% of 90 patients tested, ES 600 measured > 50% lower LH concentrations when compared with the EVIX. Moreover, in two cases LH was not detectable by ES 600 or Stratus, whereas it was normal with the EVIX. We found another five such cases and discuss here the clinical data and results of different hormone measurements in these seven cases of ‘invisible LH'. Although bioactive LH (mouse Leydig cell assay) was normal, the existence of low or even undetectable LH was clinically confusing and led to expensive complementary investigations such as gonadotrophin-releasing hormone analogue tests and magnetic resonance imaging. The uses and limitations of these assays are illustrated by different clinical situations in which the results of the different assays have been misleadin

    NTMG (N-terminal Truncated Mutants Generator for cDNA): an automatic multiplex PCR assays design for generating various N-terminal truncated cDNA mutants

    Get PDF
    The sequential deletion method is generally used to locate the functional domain of a protein. With this method, in order to find the various N-terminal truncated mutants, researchers have to investigate the ATG-like codons, to design various multiplex polymerase chain reaction (PCR) forward primers and to do several PCR experiments. This web server (N-terminal Truncated Mutants Generator for cDNA) will automatically generate groups of forward PCR primers and the corresponding reverse PCR primers that can be used in a single batch of a multiplex PCR experiment to extract the various N-terminal truncated mutants. This saves much time and money for those who use the sequential deletion method in their research. This server is available at http://oblab.cs.nchu.edu.tw:8080/WebSDL/

    Effect of bilayer coupling on tunneling conductance of double-layer high T_c cuprates

    Full text link
    Physical effects of bilayer coupling on the tunneling spectroscopy of high Tc_{c} cuprates are investigated. The bilayer coupling separates the bonding and antibonding bands and leads to a splitting of the coherence peaks in the tunneling differential conductance. However, the coherence peak of the bonding band is strongly suppressed and broadened by the particle-hole asymmetry in the density of states and finite quasiparticle life-time, and is difficult to resolve by experiments. This gives a qualitative account why the bilayer splitting of the coherence peaks was not clearly observed in tunneling measurements of double-layer high-Tc_c oxides.Comment: 4 pages, 3 figures, to be published in PR

    Generalized pricing formulas for stochastic volatility jump diffusion models applied to the exponential Vasicek model

    Full text link
    Path integral techniques for the pricing of financial options are mostly based on models that can be recast in terms of a Fokker-Planck differential equation and that, consequently, neglect jumps and only describe drift and diffusion. We present a method to adapt formulas for both the path-integral propagators and the option prices themselves, so that jump processes are taken into account in conjunction with the usual drift and diffusion terms. In particular, we focus on stochastic volatility models, such as the exponential Vasicek model, and extend the pricing formulas and propagator of this model to incorporate jump diffusion with a given jump size distribution. This model is of importance to include non-Gaussian fluctuations beyond the Black-Scholes model, and moreover yields a lognormal distribution of the volatilities, in agreement with results from superstatistical analysis. The results obtained in the present formalism are checked with Monte Carlo simulations.Comment: 9 pages, 2 figures, 1 tabl

    Radiation inactivation analysis of thylakoid protein kinase systems in light and in darkness

    Get PDF
    Chloroplast thylakoid contains several membrane-bound protein kinases that phosphorylate thylakoid polypeptides for the regulation of photosynthesis. Thylakoid protein phosphorylation is activated when the plastoquinone pool is reduced either by light-dependent electron flow through photosystem 2 (PS2) or by adding exogenous reductants such as durohydroquinone in the dark. The major phosphorylated proteins on thylakoid are components of light-harvesting complex 2 (LHC2) and a PS2 associated 9 kDa phosphoprotein. Radiation inactivation technique was employed to determine the functional masses of various kinases for protein phosphorylation in thylakoids. Under the photosynthetically active radiation (PAR), the apparent functional masses of thylakoid protein kinase systems (TPKXs) for catalyzing phosphorylation of LHC2 27 and 25 kDa polypeptides were 540 +/- 50 and 454 +/- 35 kDa as well as it was 448 +/- 23 kDa for PS2 9 kDa protein phosphorylation. Furthermore, the functional sizes of dark-regulated TPKXs for 25 and 9 kDa proteins were 318 +/- 25 and 160 +/- 8 kDa. The 9 kDa protein phosphorylation was independent of LHC2 polypeptides phosphorylation with regard to its TPKX functional mass. Target size analysis of protein phosphorylation mentioned above indicates that thylakoid contains a group of distinct protein kinase systems. A working model is accordingly proposed to interpret the interaction between these protein kinase systems

    Tunneling spectroscopy in the magnetic superconductor TmNi2B2C

    Full text link
    We present new measurements about the tunneling conductance in the borocarbide superconductor TmNi2_2B2_2C. The results show a very good agreement with weak coupling BCS theory, without any lifetime broadening parameter, over the whole sample surface. We detect no particular change of the tunneling spectroscopy below 1.5K, when both the antiferromagnetic (AF) phase and the superconducting order coexist.Comment: Submitted to Phys. Rev. B, Rapid Communication

    A novel manufacturing process and validated predictive model for high strength and low residual stresses in extra large 7xxx panels

    Get PDF
    A novel manufacturing process, enabling the production of high quality i.e. with low and controllable residual stress RS distributions and good mechanical properties T section 7xxx panels, has been established. This process provides a solution to residual stress induced distortion problems, which greatly concerns a range of industries, especially the aircraft industry. This process consists of three sequential steps water quenching WQ , cold rolling CR and constrained ageing CA . The effectiveness of this process was experimentally verified through applying this process to laboratory sized 7050 T section panels. The RS was measured by neutron diffraction and X ray techniques, in addition to deflections and hardness at each processing stage. An integrated Finite Element FE model, including all three steps, was developed to simulate this manufacturing process and predict both the RS and the final strength distributions. It has been concluded that this novel process can effectively reduce the residual stresses from 300 amp; 8239;MPa to within 100 amp; 8239;MPa and produce T section panels with required mechanical properties i.e. hardness 159 amp; 8239;HV10 . A cold rolling level of 1.5 was found most appropriate. The residual stress and yield strength distributions were accurately predicted by FE, providing a valuable prediction tool to process optimization for industrial application
    corecore