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The deposition of 1/3 of a monolayer of Pb on Ag(111) leads to the formation of PbAg(2) surface alloy with a long range ordered (√3 × √3)R30° superstructure. A detailed analysis of this structure using low-energy electron diffraction (LEED) I-V measurements together with density functional theory (DFT) calculations is presented. We find strong correlation between experimental and calculated LEED I-V data, with the fit between the two data sets having a Pendry's reliability factor of 0.21. The Pb atom is found to replace one top layer Ag atom in each unit cell, forming a substitutional PbAg(2) surface alloy, as expected, with the Pb atoms residing approximately 0.4 A above the Ag atoms due to their size difference. DFT calculations are in good agreement with the LEED results.

We observed the changes of CSF secretion from lung cells and thymocytes and the number of G-CSF receptors on bone marrow cells (BMC) in mice after single whole-body X-irradiation in the dose range of 25-250 mGy. The results showed that the CSF secretion from lung cells increased only after 75 mGy (P0.05). The response of thymocytes to low dose radiation was more sensitive and the increase of secretion reached its maximum at the dose of 50 mGy and was still higher than normal after dose up to 250 mGy X-rays (P0.05 or P0.01). The reaction equilibrium of 125I-G-CSF binding to BMC at 37 degrees C was obtained in 60 minutes, and the maximum binding (Bmax) to 3 x 10(6) BMC was 15.1 pmol, the dissociation constant(Kd) was 78.6 pmol, and the number of G-CSF receptors per cell was estimated to be about 3,100. The number of G-CSF receptors on BMC in mice 48 hours after exposure to dose of 50, 75 and 100 mGy X-rays increased significantly, being 161%, 169% and 342% of control, respectively. The results demonstrated that not only CSF production from lung cells and thymocytes was stimulated, but also the expression of G-CSF receptors on BMC was enhanced, the two factors acting together resulting in hematopoietic stimulation after low dose whole-body irradiation.

1. 1. The lysine analog l -4-oxalysine was found to be a potent inhibitor of RNA synthesis in Candida albicans. 2. 2. The compound was a weak inhibitor of protein synthesis and DNA synthesis was not affected. 3. 3. The inhibition of RNA synthesis was reversed by l -lysine but not d -lysine. 4. 4. The decrease in the level of newly synthesized RNA in cells treated with l -oxalysine was due to inhibition of de novo synthesis rather than to degradation of RNA.

It has recently been recognized that both maximum (or advancing) contact angle and contact angle hysteresis (or sliding angle) should be used to characterize superhydrophobic surfaces. In this Opinion article, we emphasize that this is still inadequate, and that the crucial role of vibrational energy from various sources should be taken into account. Furthermore, a systematic investigation into the origin and nature of vibrational energy and its effect on contact angle and contact angle hysteresis of superhydrophobic surfaces is suggested.

Glibenclamide (Gli) 0.3, 1, 3 mg.kg-1 and tolbutamide (Tol) 3, 10, 30 mg.kg-1 iv 10 min before ischemia or ouabain infusion prevented ventricular fibrillation induced by ischemia in rat and arrhythmias induced by ouabain in guinea pig. Gli 10 mumol.L-1 and Tol 1 mmol.L-1 increased APD and ERP in rat ventricular muscle. Gli 0.1, 1, 10 mumol.L-1 and Tol 0.01, 0.1, 1 mmol.L-1 prevented and reversed the shortening of APD and ERP induced by hypoxia in guinea pig ventricular muscle. These effects of Gli and Tol were dose-dependent. The results confirmed that Gli and Tol were effective on arrhythmias induced by ischemia and ouabain by blocking ATP-sensitive potassium channel.

Six saponins were isolated from the root bark of Aralia chinensis L.. The three saponins I, II and III were identified as araloside A (I), narcissiflorine (II) and oleanolic acid 3-O-beta-D-glucopyranosyl-(1-2)-beta-D-xylopyranosyl-(1-2)-alpha-L- arabinopyranoside (III). Saponin III was found to be a new compound and was named as araloside D.

Buried-heterostructure (BH) laser diodes were fabricated using both molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). MBE was used to grow the active region and the p-type cladding and contact structures while MOCVD was used for the Fe-doped, blocking layer structures. Using this method, devices were fabricated which showed good performance over the temperature range of −20–85°C. Devices were demonstrated at several wavelengths including 1550 and 1610nm. Room temperature operation of the unpackaged 1610nm devices, with coated facets, demonstrated threshold currents as low as 6mA and efficiencies of 0.3mW∕mA. The same devices operating at 85°C showed threshold currents as low as 22mA and efficiencies of 0.2mW∕mA. Coaxial, fiber pigtailed devices consistently demonstrated OC-48 dispersion power penalties of less than 1.5dB for fiber spans of 100km. Preliminary device reliability shows minimal degradation. TO-56 packaged devices operating at a constant power of 6mW at 90°C for...

In July-September 1983-1987, 57,898 adult female mosquitoes belonging to 29 species of 8 genera were collected from Japanese B encephalitis (JE) epidemic areas in Yunnan, China, and were examined by C 6/36 cell method and sucking mouse method. Twenty-eight strains of JE virus were isolated from Culex tritaeniorhychus, C. whitomorei, C. pseudovishnui, C. fuscocephala, C. annulus, C. gelidus, Anopheles sinensis, Mansonia uniformis, Aedes albopictus, Ae. Vexans, Ae. lineatopennis, and Ae. assamensis. The positive isolation rates by the two methods were 6.19% and 3.33% respectively. The highest positive isolation rate 12.3% (per 100 pools), moiquito body virus carrier rate 1:208 or moiquito body virus carrier rate 4.81% (per 1000 mosquitoes) were found in the middle ten days of August, corresponding to epidemic peak of JBE Nine strains of JE virus were isolated from C tritaeniorhychus with an isolation rate of 7.44%, natural isolation ratio was 1.584 and mosquito body virus carrier rate 1.71%. These results indicated that C. tritaeniorhynchus might be the main vector of JE virus in Yunnan, while C. whitmorei, C. pseudovishnui and An. sinensis are also important vectors of JE virus in Yunnan.

Artificial calculus bovis (ACB) is widely used in dispensing Chinese Traditional Patent Medicine as a substitute for Calculus bovis. Photodecomposition rule of ACB sample irradiated with three different light sources was studied by diffuse reflectance spectrophotometry (DRS) in this paper. The results show that, the photodecomposition rate curves of the ACB sample irradiated by all three light sources are composed of two straight lines of different slopes, indicating that they are of two-step apparent first order reaction, the apparent photodecomposition constants in the first steps are about twice as high as those in the second steps. The ACB sample has the fastest photodecomposition rate when irradiated with the UV mercury-arc lamp and the second with the fluorescent mercury-arc lamp and slowest with the iodine-tungsten lamp. In these three light sources apparent photodecomposition constants of ACB sample are respectively: K1, 2.7629 x 10(-5), 4.4132 x 10(-6); k2, 1.2176 x 10(-5), 2.0684 x 10(-6), 1.4357 x 10(-6) (lx-1.h-1). The apparent constants are independent of the product of the radiation intensity and the irradiation time, but the irradiation time is in inverse ratio of the radiation intensity to get the same proportion of the sample photodecomposition. The fading time of the ACB sample under different radiation intensity can be predicted with the kinetic equations reported. The fading time of ACB sample if directly exposed to light in bright room is 1.6 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Two crystalline components I and II were isolated from the total saponin of Kalopanax septemlobus (Thunb.) koidz. Crystalline II was identified as kalopanax saponin A and I was named as Kalopanax saponin C and eluciated as 3-O-[alpha-L-rhamnopyranosyl-(1----2)-alpha-L-arabinopyranosyl]- hedragenin-28-[alpha-L-rhamnopyranosyl-(1----2)- beta-D-glucopyranosyl (1----6)-beta-D-glucopyransyl]ester on the basis of spectral data (13CNMR, 1HNMR, IR and FAB-MS).

Full analytic solutions of the internal stress field and the radiated ultrasonic wave are obtained for a thickness‐mode piezoelectric transducer excited by a pulse voltage source, having or not having an internal resistance. Two mechanisms of transduction as well as the effect of the internal resistance on these are drawn from the complete solutions. The negative capacitance in the Mason equivalent circuit is interpreted in terms of the identified mechanism of the acoustoelectrical regenerative vibration.

HLA-A and -B typings were detected in 93 asthmatic and 98 normal subjects, all of them of Han nationality, in Shenyang. Antigen frequencies of HLA-A9, A10, Bw61 and Bw62 were found to be much higher than those of normal controls, and -A3 much lower (p less than 0.05). However, after the p-values were corrected, the significant difference was only existing in HLA-Bw61 (pc less than 0.01) with a relative risk of 6.6 (HLA frequencies were 0.2366 and 0.0408 in patient group and control, respectively). Our results indicate a significant association between HLA-Bw61 and the asthmatic patients of Han nationality in Shenyang area, North-east China.

In this paper, the decoction of Yiguan Jian is reported to have significant fatigue-resisting, hypoxia-resisting, antiinflammatory, sedative, analgesic, extracorporal bacterio-static actions, and also to strengthen the phagocytosis of Phagocytes. Besides, the drug can antagonize acetylcholine-induced spasm of isolated intestinal muscles in rabbits. The decoction has proved safe for use. This study provides some experimental basis for clinical use in nourishing yin, invigorating the liver and treating many diseases.

m-Nisoldipine 4, 8, 16 nmol/L, nisoldipine 1, 4 nmol/L and nifedipine 4, 8, 16, 50 nmol/L enhanced the recoveries of functional parameters of working rabbit hearts after ischemia-reperfusion, as well as prevented the development of contracture and the release of CPK from the reperfused hearts. m-Nisoldipine 8 nmol/L, nisoldipine 1 nmol/L and nifedipine 8 nmol/L attenuated the reduction of myocardial Na+-K+-ATPase and 5'-nucleotidase activity induced by ischemia-reperfusion. The breakdown of membrane phospholipids and elevation of the myocardial Ca2+-ATPase activity and the free fatty acids level were also prevented.