Effects of periods of nonuse and fluctuating ammonia concentration on biofilter performance.

A systematic study on the transient behavior of odor treatment using biofilters is described. The biofilters were exposed to variations in contaminant loading and periods of nonuse. Two bench-scale biofilters with different filter media were used.

Experimental verification of dispersed fringe sensing as a segment phasing technique using the Keck telescope.

Dispersed fringe sensing (DFS) is an efficient and robust method for coarse phasing of segmented primary mirrors (from one quarter of a wavelength to as much as the depth of focus of a single segment, typically several tens of microns). Unlike phasing techniques currently used for ground-based segmented telescopes, DFS does not require the use of edge sensors in order to sense changes in the relative heights of adjacent segments; this makes it particularly well suited for phasing of space-borne segmented telescopes, such as the James Webb Space Telescope. We validate DFS by using it to measure the piston errors of the segments of one of the Keck telescopes.

Temperature dependence of the thrombin-catalyzed proteolysis of prothrombin.

Measurement of the temperature-dependence of thrombin-catalyzed cleavage of the Arg(155)-Ser(156) and Arg(284)-Thr(285) peptide bonds in prothrombin and prothrombin-derived substrates has yielded Arrhenius parameters that are far too large for classical mechanistic interpretation in terms of a simple hydrolytic reaction. Such a difference from the kinetic behavior exhibited in trypsin- and chymotrypsin-catalyzed proteolysis of peptide bonds is attributed to contributions by enzyme exosite interactions as well as enzyme conformational equilibria to the magnitudes of the experimentally determined Arrhenius parameters. Although the pre-exponential factor and the energy of activation deduced from the temperature-dependence of rate constants for proteolysis by thrombin cannot be accorded the usual mechanistic significance, their evaluation serves a valuable role by highlighting the existence of contributions other than those emanating from simple peptide hydrolysis to the kinetics of proteolysis by thrombin and presumably other enzymes of the blood coagulation system.

[Study on the prevalence of arthritis and relevant factors in Shanghai].

Objective: This study aimed to understand the prevalence rate, epidemiological characteristics and relevant factors of arthritis in Shanghai.

Methods: A sample of 7 575 residents aged 15 years and above was drawn from 6 communities under multiple stage cluster sampling. A household survey with questionnaire was carried out to differentiate both undiagnosed patients and those with definite arthritis.

[Survey of infection of Toxoplasma gondii in infertile couples in Suzhou countryside].

Objectives: To determine the level of anti-Toxoplasma antibody in serum of infertile couples to explore the relationship between toxoplasma infection and infertility.

Methods: Enzyme-linked immunosorbent assay (ELISA) was applied to detect the anti-Toxoplasma antibody, antisperm antibody (AsAb) and anticardiolipin antibody (ACA) in serum of 178 couples with infertility and 190 couples who had normal pregnant history.

Results: The positive result of Toxoplasma infection in the infertile couples was significantly higher than that in fertile couples which was 34.