Pyrazole-related nucleosides. 4. Synthesis and antitumor activity of some 1-tetrahydropyranyl-4-substituted pyrazoles

Continuing our studies on the structure-activity relationships of some pyrazole nucleosides (1a-h) structurally related to ribavirin, tiazofurin and selenazofurin, we describe here the synthesis and antitumor/antiviral/antimicrobial activity of a new series of 1-tetrahydropyranyl-4-substituted pyrazoles. In this study, the tetrahydropyranyl moiety (THP), designed as a mimic of the glycosidic portion of the parent compounds 1a-h, has led to a few derivatives with moderate cytotoxic activity against leukemia/lymphoma and solid tumor-derived cell lines (IC50 14-100 microM). The compounds obtained through substitution of the ribofuranosyl moiety by the THP moiety were still active, the free heterocyclic bases were devoid of any activity.     

Free-stream turbulence effects on the boundary layer of a high-lift low-pressure-turbine blade

The suction side boundary layer evolution of a high-lift low-pressure turbine cascade has been experimentally investigated at low and high free-stream turbulence intensity conditions.Measurements have been carried out in order to analyze the boundary layer transition and separation processes at a low Reynolds number,under both steady and unsteady inflows.Static pressure distributions along the blade surfaces as well as total pressure distributions in a downstream tangential plane have been measured to evaluate the overall aerodynamic efficiency of the blade for the different conditions.Particle Image Velocimetry has been adopted to analyze the time-mean and time-varying velocity fields.The flow field has been surveyed in two orthogonal planes (a blade-to-blade plane and a wall-parallel one).These measurements allow the identification of the Kelvin-Helmholtz large scale coherent structures shed as a consequence of the boundary layer laminar separation under steady inflow,as well as the investigation of the three-dimensional effects induced by the intermittent passage of low and high speed streaks.A close inspection of the time-mean velocity profiles as well as of the boundary layer integral parameters helps to characterize the suction side boundary layer state,thus justifying the influence of free-stream turbulence intensity on the blade aerodynamic losses measured under steady and unsteady inflows.     

A 120-dB Dynamic Range CMOS Image Sensor With Programmable Power Responsivity

A high dynamic range CMOS image sensor providing a user-programmable power responsivity curve is presented. Each pixel integrates, besides a 4T active pixel structure, a voltage comparator and an analog memory to implement a time-to-saturation scheme while also providing the standard integrated photo-current signal. The sensor generates two 10-bit analog outputs allowing a typical dynamic range exceeding 120 dB with a temporal noise lower than 0.13% and a fixed pattern noise of 0.4% (1.7%) of the total signal swing (2 V) at low (high) irradiance without any external calibration procedures. A 140 times 140-pixel array has been fabricated in a 0.35-mum, two-poly four-metal (2P4M), 3.3-V standard CMOS technology. The chip measures 3.9 times 4.6 mm² with a pixel pitch of 15 mum and a fill factor of 20%.     

Profile and secondary flow losses in a high-lift LPT blade cascade at different reynolds numbers under steady and unsteady inflow conditions

The aerodynamic flow field downstream of a Low-Pressure High-Lift(HL)turbine cascade has been experimentally investigated for different Reynolds numbers under both steady and unsteady inflows,in order to analyse the cascade performance under real engine operating conditions.The Reynolds number has been varied in the range 100000相似文献   

Aqueous solutions of uranium(VI) as studied by time-resolved emission spectroscopy: a round-robin test

Results of an inter-laboratory round-robin study of the application of time-resolved emission spectroscopy (TRES) to the speciation of uranium(VI) in aqueous media are presented. The round-robin study involved 13 independent laboratories, using various instrumentation and data analysis methods. Samples were prepared based on appropriate speciation diagrams and, in general, were found to be chemically stable for at least six months. Four different types of aqueous uranyl solutions were studied: (1) acidic medium where UO2(2+)aq is the single emitting species, (2) uranyl in the presence of fluoride ions, (3) uranyl in the presence of sulfate ions, and (4) uranyl in aqueous solutions at different pH, promoting the formation of hydrolyzed species. Results between the laboratories are compared in terms of the number of decay components, luminescence lifetimes, and spectral band positions. The successes and limitations of TRES in uranyl analysis and speciation in aqueous solutions are discussed.     

Molecular composition of two different batches of urofollitropin: analysis by immunofluorimetric assay, radioligand receptor assay and in vitro bioassay

A multi-institutional randomized trial of alfacalcidol (1 alpha hydroxyvitamin D3) was performed to determine the therapeutic effect of alfacalcidol in patients with refractory myelodysplastic anaemias. Twenty-three evaluable patients were randomized to receive either a single daily oral dose of 6 micrograms of alfacalcidol or only supportive care as a control. Treatment was continued, whenever possible, for a period of 6 months. Response was assessed by weekly blood counts, clinical course and repeated marrow examinations. No significant difference was noted between the alfacalcidol and control groups. Three of the 13 patients in the alfacalcidol group, and two of the 10 patients in the control group, suffered a progression of their disease. One patient with refractory anaemia showed a good response to alfacalcidol in all three haematopoietic cell lineages; the response, however, could not be maintained, because discontinuation of the drug resulted in a worsening of pancytopenia which was refractory to a second course of alfacalcidol therapy. Hypercalcaemia was the major toxic side-effect of alfacalcidol therapy. The results indicate that alfacalcidol therapy, when used alone, does not induce a beneficial effect in patients with refractory myelodysplastic anaemias.     

"Lesbian and gay male group identity attitudes and self-esteem: Implications for counseling": Erratum.

Reports errors in the original article by K. L. Walters and J. M. Simoni (Journal of Counseling Psychology, 1993[Jan], Vol 40(1), 94–99). Two errors were made in Table 3. First, the reported statistics were not identified. For all but columns C and D, the statistics are standardized beta weights from multiple regression analyses. The statistics in columns C and D are simple correlations. Second, in column D, the respective values for the preencounter and immersion-emersion stages should be –.41* (not –.35*) and –.15 (not –.40). (The following abstract of this article originally appeared in record 1993-13378-001.) 96 lesbians and gay men (aged 18–46 yrs) completed the Rosenberg Self-Esteem Scale and a modified version of J. E. Helms and T. A. Parham's (1985) Racial Identity Attitude Scale (RIAS). Based on W. E. Cross's (1971, 1978) model of African-American identity development, the RIAS assesses 4 distinct psychological stages (preencounter, encounter, immersion-emersion, and internalization), which are thought to correspond to a parallel process in the development of gay male and lesbian group identity attitudes.… (PsycINFO Database Record (c) 2010 APA, all rights reserved)