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Structure and magnetic properties were studied for Tm2(Co1−xFex)17 bulk nanocrystalline magnet synthesized by spark plasma sintering technique. X-ray diffraction results indicate both ingot and sintered magnet of Tm2(Co0.7Fe0.3)17 alloy exhibit hexagonal Th2Ni17 type structure. The microstructure of the magnet is composed of Th2Ni17 type nanograins with an average size of 35 nm detected by transmission electron microscopy and selected area electron diffraction patterns. Magnetic measurement shows that the remanence of the magnet is higher at 573 K than at 300 K, indicating there is a positive remanence temperature coefficient in the magnet. The anisotropy field of Tm2(Co0.7Fe0.3)17 alloy is 3.8 T, which is much higher than the HA of 2.3 T for the pure Tm2Co17 alloy. The coercivity of the sintered magnet increases from 0.25 to 0.354 T after optimal annealing.

Six saponins were isolated from the fruit pedicels of Panax notoginseng. Five of them were identified as gypenoside-XVII, -XV, ginsenoside-Rb1, and notoginsenoside-Fc, -Fa on the basis of chemical methods, spectroscopic analysis and comparison with authentic standards. Quantitative determination of the major saponins in fruit pedicels from the plant was made by thin layer chromatography-densitometry.

Six saponins were isolated from the fruit pedicels of Panax notoginseng for the first time. They were identified as ginsenoside-Rc, -Rb3, -Re, notoginsenoside-Fe, -R1 and gypenoside IX by chemical and spectroscopic analysis.

EEG data from 400 healthy adult volunteers in the Xining area (with an altitude of 2260 meters) are summarized to show changes in indices of waves, frequencies and amplitude. Analysis and observations were made for tests of eyes open-close, acoustic stimulation and hyperventilation. Differences in EEGs were compared between males and females of various age groups, and between adults living at the higher elevations in Xining and those living on the plains in the Beijing area (altitude 40 meters). Comparisons showed that EEG characteristics of healthy adults at the higher altitude were: an increase in the incidence of abnormality, a decrease of alpha indices, an increase in the number of slow waves, the appearance of spikes and sharp waves, and a reduction in the level of sensitivity to activation tests.

A retrospective study of flow cytometric measurements on paraffin-embedded tumor specimens from 188 patients with bladder tumor was conducted. Results were analyzed in combination with the morphological variation in bladder tumors. It was found that the deoxyribonucleic acid (DNA) ploidy pattern, the degree of infiltration and the multiplicity of bladder tumor were closely related with tumor recurrence, among which the DNA ploidy pattern was most significant. In aneuploid bladder tumors, the recurrence rate and the mean annual recurrence frequency were 76.7% and 1.46, respectively, and in the diploid bladder tumors, they were 18.7% and 0.33, respectively. Aneuploidy was the most indicative parameter of recurrence in bladder tumors. In addition, according to the DNA content and the ploidy level of the aneuploid cell lines, the aneuploid tumors in our group were divided into four types, namely tetraploid tumors, noneuploid tumors with an DNA index (DI) less than or equal to 1.5, hypotetraploid tumors and aneuploid tumors with several cell lines. The results showed that the recurrence rate of tetraploid tumors was relatively lower, and it became higher and higher in the following order: noneuploid tumors with DI less than or equal to 1.5, noneuploid tumors with DI greater than 1.5, and two-aneuploid tumors. This indicates that there are different biological behaviors in tumors with different ploidy patterns. Finally, the correlation between the DNA ploidy pattern and tumor metastases was also discussed.

In the estimation of heritability, various non-genetic factors must be excluded from the variance of sire or dam. The methods of sib correlation within unit, suggested by professor Sheng Zhilian is commonly used in China. This paper will provide evidence to verify this method theoretically and discuss the application of the method to systematic classification. In addition, in this paper the author suggest some other methods to estimate heritability by using analysis of variance within unit when the blood relationship exists between sire and dam. These methods not only make the estimation procedure of hertability simple but also have the same function of analyzing variance with multiple factors.

In this paper, electron-doped La0.8Te0.2MnO3 film has been prepared on SrTiO3 (100) substrate by pulsed laser deposition method, and the photoinduced resistivity change and colossal magnetoresistance effect have been investigated. The results show that the film has a high metal-insulator transition temperature TMI of ∼283 K and the maximum magnetoresistance ratio is ∼24% at 0.7 T. Under laser irradiation, TMI varies from 283 to 243 K and resistivity increases below TMI, while it decreases above TMI. The maximum photoinduced resistivity change in resistivity (LR%) is 134.8%. The photoinduced relaxation character of the film indicates that the relaxation of photoinduced character relates to the excitation of small polarons.

Cytogenetic properties of a human rectal carcinoma cell line (HR-8348) established in China are described. The early (29th passage) and late (93rd passage) passage cells were used for chromosome analysis. HR-8348 was found to have an essentially triploid karyotype. This distribution of chromosome numbers was rather dispersed in early passage, whereas it was concentrated in the 65-70 range in late passage. G-banded karyotype analysis also showed that the numerical distribution of chromosomes was dispersed in early passage and was associated with more abnormal chromosomes. In late passage, the numerical distribution became more stable and the number of abnormal chromosomes was reduced. In 60 metaphases analyzed, 10 marker chromosomes were found. The frequencies of M1, M2 and M3 were 100% in both early and late passage cells. The morphological characteristics of these marker chromosomes and their possible origin and role in the pathogenesis of colorectal carcinoma are discussed.

Antigenic analysis of recently isolated H1 influenza viruses was performed using haemagglutination inhibition (HI) assay with monoclonal antibodies to the haemagglutinin (HA) subunit. Tests using monoclonal antibodies against the HA of the A/England/333/80 (H1N1) and A/Yamagata/120/86 (H1N1) viruses revealed that the major antigenic drift occurred in 1985 or 1986 and A/Dunedin/6/83-like virus became a major strain after 1986.

The present study provides evidence that green tea extract (GTE), consisting of polyphenol components, is a highly active nucleoside transport inhibitor. GTE markedly inhibited radiolabeled thymidine and uridine transport in mouse leukemia L1210 cells, with IC50 values of 3.2 and 8.0 mumol/L, respectively. GTE blocked the rescue effect of exogenous nucleosides and enhanced the cytotoxicity of AraC and MTX to L1210 cells and human hepatoma BEL-7402 cells. GTE markedly potentiated the inhibitory effect of AraC on leukemia L1210 and P388 in mice. These results indicate that GTE is potentially useful when combined with antimetabolites in cancer chemotherapy.

In this work, we propose an approach to realize field-dependent multimode quantized thermal conductance by introducing both harmonic and anharmonic couplings to a quantum wire. It is demonstrated theoretically that by stretching (or compressing) the wire, phononic band structures are tuned and multiple phononic channels are opened one by one. In this way, multiple-step quantized thermal conductance is realized. The research opens a way to manipulate heat transfer in mesoscopic phonon systems.

We investigate spin-dependent transport in ferromagnetic metal (FM)/semiconductor (SC) cascade junctions, which can be denoted as (FM∕SC)n∕FM. Here, n is the repeated number of FM/SC junction. In the Landauer framework of ballistic transport, we have calculated the spin-dependent transmission and the spin polarization in these cascade junctions. It is shown that spin-up and spin-down electrons possess different bandgap structures against the Rashba spin-orbit wave vector. As a result, high spin polarization can be achieved. Besides, resonant transmission for spin-up or spin-down electrons can be observed within the bandgap when we intentionally change the magnetization of FM in the center of the cascade junctions. Around resonant wave vector, spin polarization will be reversed. Our investigations may have potential applications in spin filters and spin switches.

Pretreatment to guinea pigs with sc isoprenaline (Iso) 10 micrograms/kg tid x 7 d reduced the effect of Iso on protecting histamine-induced asthma and decreased its pD2 values in relaxing isolated tracheal strip. This treatment did not change the asthmatic effect induced by histamine and the effect of Iso on positive chronotropic action, but elevated the blood pressure. These results suggest that it is easier to develop the tolerance of beta 2-adrenoceptors of respiratory smooth muscles than that of beta 1-adrenoceptors of heart. Radioligand binding assay showed that the treatment decreased the number of binding sites of beta-adrenoceptors on lungs of guinea pigs but did not change the binding affinity.

Two-dimensional echocardiography was used to guide and locate the balloon of Swan-Ganz catheter during catheterization in 43 patients. The echoes of balloon appeared as a series of strong light spots, with a rate of detection of 100%. Under monitoring of two-dimensional echocardiography, the site of balloon and its moving route could be determined. The coincidence of echographic findings and X-ray findings showed that it can be used instead of X-ray monitoring to lessen irradiation during catheterization. The depth of catheter inserted was measured. The differential points between the echoes of balloon and tubing, the terminology of the balloon site in echocardiography and fluoroscopy, its clinical value and limitation are discussed.

Using non-linear inverse techniques we show that borehole temperature measurements, taken with time after mud circulation stops, can be used to provide very precise estimates of true formation temperatures and of mud temperature at the time circulation stops. In addition, ruggedly stable estimates can also be made of the thermal invasion distance, the formation thermal conductivity and the efficiency of heating the mud by the thermal recovery wave. Of novelty is the fact that convective heat flow into (or out of) the formation influences the thermal recovery. We show that the flow rate at the borehole can also be obtained approximately from the borehole temperature measurements using the inverse method. Fidelity and reproducibility of the inverse procedure are examined using synthetic data. Applications to field data from four wells in the North Sea and five wells in the Cooper basin of Australia confirm the accuracy of the method in satisfying the observed data, in determining true formation temperatures, and in assessing the magnitude of fluid penetration into the formation.

Since 1983, we have been conducting inhibitory therapy for precancerous lesions of the esophagus in two regions of Henan Province considered high-risk areas of esophageal carcinoma. Our goal was to effect a 50% reduction in the canceration rate of marked esophageal dysplasia. By means of a cytological survey, 2531 cases of marked esophageal dysplasia and 3393 cases of mild esophageal dysplasia were selected. The former were randomly divided into 3 groups for antitumor-B (ATB, a mixture of Chinese herbs), retinamide (4-ethoxycarbophenylretinamide) and placebo treatment respectively, and the latter into 2 groups treated with riboflavin and placebo respectively. Treatment was continued for 3 or 5 years (administration rate greater than 90% in all groups) and esophageal cytology reexamined (reexamination rates were 94.1% and 92.5% respectively). Our results were as follows: 1) ATB 3- and 5-year subjects saw the canceration rate of marked esophageal dysplasia drop by 52.2% and 47.3% respectively as compared to control (P less than 0.01). 2) Retinamide lowered the canceration rate by 37.3% after a 3-year treatment period, with this reduction reaching 43.2% after an additional 2 years of treatment with increased dosages (P less than 0.05, P less than 0.01). 3) In the riboflavin group, the canceration rate of mild esophageal dysplasia was reduced by 22.2% and 34.8% after 3 and 5 years of treatment respectively, but these differences were not statistically significant. The above results verify the efficacy of medicamentous inhibitory therapy for esophageal precancerous lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

We report here the theoretical studies on electronic delocalization and resonant transmission in symmetric metallic nanowires (SMNs). Resonant transmissions, which are characterized by multiple perfect transmission peaks, have been found in the electronic band gap. The resonant energy and the number of modes of resonant transmission therein can be manipulated, and the quality factor of the perfect transmission peak can be exponentially increased. We suggest that the resonant transmission originates from the electronic delocalization in SMNs, which is characterized by the extended wave function of electrons around the resonant energy. These features open a unique way to control quantum transport in nanodevices.

We theoretically studied the magnetostatic excitation in self-similar antiferromagnetic(AF)/nonmagnetic(NM) multilayers, where the AF and NM layers were arranged in a Thue-Morse sequence. The dispersion relation of magnetostatic spin waves and the precession amplitude of the total magnetization were achieved. It is shown that the distribution of eigenfrequencies possesses two bands of dual structures and each subband presents a hierarchical feature. The states in the finite system can be categorized to three types: critical states in the subband, extended states in the band, and localized surface states in the gaps. The multiformity in frequency spectra leads to the tunable magnetostatic wave, which may have potential applications in designing devices of magnetostatic waves for microwave communications.

We investigate magnetic-flux-induced persistent currents in one-dimensional symmetric-polymer (SP) mesoscopic ring, where a defect cluster is embedded into two periodic clusters and the whole cluster possesses mirror symmetry. Under tight-binding approximation, the flux-dependent energy spectra, electronic wave functions, and persistent currents are obtained. It is shown that the energy spectra form band structure and the defect modes appear in the band gap. The persistent current (PC) depends on the magnetic flux, the site energy, and the Fermi level. Particularly, by changing the Fermi level, the SP ring presents metallic and insulative features alternately. Our investigations provide a possible model to explain the anomalously large PC observed in some experiments and contribute to the potential application in quantum-switch devices.

Simple oxide heterostructures have been fabricated by growing multiferroic TbMnO3 thin film on Nb-1 wt %-doped SrTiO3 substrate. In addition to the beneficial rectifying characteristics in a temperature range from 350 to 30 K, the intriguing observation is that at constant reverse bias the current increases with decreasing temperature below 275 K. By analyzing the band diagram, the anomalous increasing current with decreasing temperature was ascribed to the strain-assisted tunneling current through TbMnO3∕Nb-doped p–n junctions.

Under the tight-binding approximation, we study the persistent current (PC) in the magnetic-flux-threaded mesoscopic ring which is constructed according to the Fibonacci-class model. It is shown that the energy spectra form band structures and the subbands present a self-similarity. The PC is determined by the magnetic flux, the site energy, and the Fermi level. It is found that the large PC can be observed if the Fermi level reaches a specific value. Our investigation provides detailed information on the structural influence on the PC and contributes a mechanism to understand the large PC observed in the experiments.

A well mixed recirculating indoor channel was adopted to investigate aerobic heterotrophic biodegradation in drainage systems with suspended and attached biomass. The focused points include microbial activity and intrinsic kinetics of the liquid and biofilm, and the process kinetics. The linkage between reactor performance and the characteristics of biomass population was noticed.

A newly-developed phosphorus source, tertiarybutylphosphine (TBP), which is much less toxic than PH3, has been used to grow InP and GaAs1-xPx by atmospheric pressure organometallic vapor phase epitaxy (OMVPE). Excellent morphologies are obtained for the growth of InP between 560 and 630° C for TBP partial pressures larger than 0.5 x 10-3. For the first time, V/III ratios as low as 3 have been used to grow InP epilayers with featureless morphologies at 600° C. To obtain good morphologies at both lower and higher temperatures, higher TBP partial pressures are necessary. The electron mobility increases and the electron density decreases as the temperature is increased. The highest room temperature mobilities and lowest electron densities, obtained at 630° C, are 3800 cm2/V-sec and 3 x 1015 cm-3, respectively. The 10 K photoluminescence spectra of the InP epilayers at higher growth temperatures show no carbon contamination. Bound excition half widths as low as 3.0 meV have been measured. The use of TBP to replace PH3 in the growth of GaAs1-xPx results in a nearly linear relationship between vapor and solid composition at 610° C,i.e., the P distribution coefficient is nearly unity. This contrasts sharply with the very low P distribution coefficient obtained using PH3 at such low growth temperatures.

High‐quality Ga0.51In0.49P, lattice‐matched to GaAs, has been grown by atmospheric pressure organometallic vapor‐phase epitaxy. The growth was performed at a temperature of 680 °C and a growth rate of about 12 μm/h. The indium distribution coefficient was found to be unity at this growth temperature. At a V/III ratio of 148, the Ga0.51In0.49P epilayers had photoluminescence (PL) half‐widths of 35 and 7.2 meV at 300 and 10 K, respectively, the best reported results to date. As the V/III ratio was changed from 94 to 240, the 300‐K energy band gap measured by PL varied only from 1.897 to 1.912 eV, values close to that of Ga0.51In0.49P grown by liquid‐phase epitaxy. An ordered arrangement of gallium and indium atoms on the column III sublattice with a Cu‐Pt structure was observed in transmission electron diffraction patterns for all samples. Our results show that the phenomenon of changing energy band gap with varying V/III ratio does not occur at these high growth rates.

Bp8 ascites sarcoma cells growing in vivo were whole body irradiated with doses of 1.75 to 8 Gy. The inflow and outflow rates of cells in the various compartments of the cell cycle were estimated on the basis of sequential analysis of the total number of cells and from the proportion of cells in G1, S-phase, G2 and M. The flow through the compartments was calculated from these data and from the sizes of the cell pools. The durations of the mitotic delay, the G1-depletion and the early G2 blockage were linearly related to the dose. After release of the mitotic division delay the accumulation rate of cells in M and G1 decreased linearly with the dose; for G2, plateau values for the accumulation rate were found after 2.5 Gy. The outflow rates from G2 and M after release of the G2 blockage showed a shoulder type of dose-response with a D0 of 2.5 Gy and a n value of 1.5. In addition to an increase in the duration of G2, generally responsible for the increase in the total cell cycle time at about 24 hours after irradiation and an increase in the duration of the S-phase up to 12 hours after irradiation, an early increase in the duration of G1 and M was observed.

Split dose irradiation with 2 X 2.5 Gy at intervals of 3 to 48 h was compared with the effect of a single irradiation with a 5 Gy dose in Bp8 mouse ascites sarcoma growing in vivo. The total number of cells and, using rapid-flow cytofluorometry, the proportions of cells in the various parts of the cell cycle were determined up to 10 days after irradiation. In addition, from sequential analyses of the total number of cells in the various compartments of the cell cycle, the flow of cells through the cell cycle was calculated. As judged by the growth in the total number of cells, a rapid repair of at least 20 per cent per h up to 3 h is followed by a slow repair of about one per cent per h during the following 45 h. The proportion of cells in the cell cycle following the conditioning dose did not differ enough to expect a significant influence on the mean radiation sensitivity of the cell population. At split time intervals of 12 to 48 h, after a transient early increase of the flow of cells through the cell cycle, the flow of cells was markedly reduced in all parts of the cell cycle with a maximum 24 to 48 h after the second dose of irradiation. This increase in the cell cycle time was not found following single dose irradiation and may influence the repair of potentially lethal cell damage.