No involvement of APC gene mutations in ulcerative colitis-associated rat colon carcinogenesis induced by 1-hydroxyanthraquinone and methylazoxymethanol acetate

In 1992, 1531 women aging 25-45 years from 5 urban and rural regions were interviewed about infertility and subfecundity within the German part of a study by the European community. 1248 of them had a positive reproductive history with 3018 pregnancies. 400 (= 13.25%) occurred during contraception. This affected 296 women (= 19.6% of all women). Smoking seems to have a promotion effect. The risk of ectopic pregnancies seems to be higher in contraceptive users. The highest fetal loss was found in women using an IUD. There were no differences in the course and outcome of pregnancy between users and nonusers of contraceptives. About 40% of the women in the corresponding group reported an irregular application of the contraceptive technique.     

Preparation and mesostructure control of highly ordered zirconia particles having crystalline walls

Mesostructured zirconia particles having monoclinic-type crystalline walls were prepared using a low-temperature crystallization technique. Crystalline zirconia particles with highly-ordered mesostructures were obtained through the sol–gel process of zirconium sulfate tetrahydrate at 333 K in the presence of molecular self-assemblies of cetyltrimethylammonium bromide (CTAB) or mixtures of CTAB and anionic molecules such as sodium dodecyl sulfate and sodium p-toluenesulfonate. Variations in the molar ratios of CTAB and the chemical species of anionic molecules led to the variations in the periods of highly-ordered zirconia having crystalline walls. Calcination of the mesostructured zirconia particles prepared using templates consisting solely of CTAB yielded crystalline mesoporous zirconia particles.     

Some experiments on the micro-indentation of digital audio tape

The durability of digital audio tape is a function of the elastic and plastic properties of the magnetic layer and substrate. In this work a micro-indentation method has been used to estimate these properties. The loading part of the compliance curve (load against indentor penetration) is analysed to obtain magnetic layer hardness. The unloading part is used to determine the reduced elastic modulus. Indentations at various depths have been recorded and an extrapolation technique used to predict layer properties. Rate dependence of the magnetic layer has been studied through constant loading rate tests. Results are presented isochronally, to indicate any viscous elastic–plastic non-linearities.     

Influence of water vapor on the reduction of cuprous chloride to copper microfibers

Reduction of cuprous chloride has been examined in various atmospheres, mostly at 600°C, to produce copper microfibers that can be applied as a filler for electromagnetic interference shielding and electron conductive paste composites. The reduction with hydrogen resulted in formation of a large amount of copper films, but fine particles and short filaments were obtained when carbon black was mixed into the raw material. The most promising copper microfibers with dimensions of several mm length and 1–10 m thickness could be produced with the system CuCl — C — H₂O using argon as a carrier gas, where H₂ and CO formed then probably reduced the vaporized CuCl molecules. Introduction of hydrogen gas into this system increased the yield of copper microfibers, though they became more bent, curved and kinked in shape. However, the morphology of the microfibers is still acceptable as a filler.     

Two efficient schemes for dynamic analyses with finite elements

This paper proposes two efficient schemes that may be applied to finite element analyses in the frequency domain, such as those currently used to analyze nuclear power plants under seismic loads. The first scheme consists of a reduction in the number of degrees of freedom necessary to model an axisymmetric system, using what is referred to as the quasi-cylindric approximation (not a plane strain approximation!). The second scheme is the use of Hermite interpolation to decrease the computational effort associated with the determination of the transfer functions. The application of the technique is reviewed for the case of a Waas-Lysmer transmitting boundary (a similar boundary is used in the computer program FLUSH), and the relative efficiency is discussed.     

Adaptive inverse halftoning for scanned document images through multiresolution and multiscale analysis

This paper describes an efficient algorithm for inverse halftoning of scanned document images to resolve problems with interference patterns such as moiré and graininess when the images are displayed or printed out. The algorithm is suitable for software implementation and useful for high quality printing or display of scanned document images delivered via networks from unknown scanners. A multi-resolution approach is used to achieve practical processing speed under software implementation. Through data-driven, adaptive, multi-scale processing, the algorithm can cope with a variety of input devices and requires no information on the halftoning method or properties (such as coefficients in dither matrices, filter coefficients of error diffusion kernels, screen angles, or dot frequencies). Effectiveness of the new algorithm is demonstrated through real examples of scanned document images, as well as quantitative evaluations with synthetic data.     

Cloning and characterization of cDNAs encoding S-RNases from almond (Prunus dulcis): primary structural features and sequence diversity of the S-RNases in Rosaceae

The ability of histamine H3 receptor ligands to interact with 5-HT3 receptors in NG108-15 cells was studied using the whole cell patch clamp recording technique. Imetit, a histamine H3 receptor agonist, generated inward currents and exhibited weak partial agonist activity at the 5-HT3 receptor (EC50 = 11.8 microM). Imetit-induced currents were slow to desensitize and at a high concentration reduced in size. The histamine H3 receptor antagonists iodophenpropit and thioperamide did not generate inward currents but were able to inhibit 5-hydroxytryptamine (5-HT) responses with an IC50 of 1.57+/-0.3 microM and 13.7+/-3.5 microM, respectively. Thioperamide is probably a non-competitive antagonist which may have more than one binding site on the receptor.     

Numerical Study on Particle Motions in Swirling Flows in a Cyclone Separator

The purpose of this study is to establish the high-accurate prediction method of particle separation in a cyclone separator. Numerical simulation of the swirling flows in a cyclone separator is performed by using a large eddy simulation (LES) based on a Smagorinsky model. The validity of the simulation and the complicated flow characteristics are discussed by comparison with experimental results. Moreover, particle motions are treated by a Lagrangian method and are calculated with a one-way method. A performance for particle separation is predicted from the results of the particle tracing. As results of our investigation, the influences of the inserted height of the outlet pipe on the performance for particle separation of cyclone separator are shown.     

煅烧炉用喷射耐火料的近期发展趋向

开发了一种干式喷射隔热材料,其热导率与隔热板一样低.它正取代普通的隔热板,因它的安装方便,工作环境较好.另外,我们已开发了新的湿式喷射料体系,它效率高,工作环境好.