[en] Novel history dependence and logarithmic time dependence of the microwave surface resistance were observed in polycrystalline YBa₂Cu₃O_7-x in a magnetic field. The authors interpret the data in terms of granularity and relates the surface resistance to the number of fluxons in the sample. At a given field, the surface resistance of a zero-field-cooled sample is higher than that of a field-cooled sample, suggesting that the former contains more intergranular fluxons. It is also observed that once the external dc field is removed, flux creep out of the sample results in a logarithmic time decay of the surface resistance. For a more quantitative prediction, a 2-level critical state model was developed for calculating the intergranular fluxon density. The model is capable to deal with the flux profiles on both macroscopic and local levels and to explain some anomalous magnetic hysteresis as observed experimentally. With their controllable parameters, artificially fabricated Josephson-junction arrays provide a model granular system for the study of high-T_c superconductor. Here the author presents the first microwave loss measurement in large arrays

[en] A nitrate-citrate gel was prepared from metal nitrates and citric acid by sol-gel process, in order to synthesize Ni_0.25Cu_0.25Zn_0.50Fe₂O₄ ferrite. The thermal decomposition process was investigated by DTA-TG, IR and XRD techniques. The results revealed that the nitrate-citrate gel exhibits self-propagating combustion behavior. After combustion, the gel directly transformed into single-phase, nano-sized NiCuZn ferrite particles with spinel crystal structure. The synthesized powder can be densified at a temperature lower than 900 deg. C. The sintered body possesses fine-grained microstructure, good frequency stability and high-quality factor compared to the sample prepared by conventional ceramic route

[en] The cell survival curve of the CFU-f in the guinea-pig bone marrow, which is distinguished according to the cellular density of colony, is assayed. By the analysis of the relative data from the experiment and the observation of the morphology of colony. There are two distinct subpopulations in radiosensitivity and colonial morphology among the CFU-f populations in the guinea-pig bone marrow. The dense cellular colony type subpopulation of the CFU-f: D₀ = 2.17 Gy, N = 1.14; the sparse cellular colony type subpopulation of the CFU-f: D₀ = 4.09 Gy, N = 1.13. The studies may have important implication in acquiring a better understanding of the characteristics of the radiation biology as well as the rule of the radiation injury and recovery of the CFU-f

[en] Layered double hydroxides, novel anionic clay, meet the first requirement as inorganic matrices for encapsulating functional drugs or biomolecules with negative charge in aqueous media. In this study, naproxen has been intercalated into Mg-Al layered double hydroxide by the methods of ion exchange. The structure and composition of the intercalated material have been studied by X-ray diffraction (XRD), UV-vis spectroscopy and inductively coupled plasma emission spectroscopy. A schematic model has been proposed. Furthermore, in situ Fourier transform infrared spectroscopy, in situ high-temperature XRD, and thermogravimetry (TG) have been used to characterize the thermal decomposition of the hybrid material. It has been found that the thermal stability of the intercalated naproxen is significantly enhanced compared with the pure form before intercalation, which suggests that this drug-inorganic layered material may have prospective application as the basis of a novel drug delivery system

[en] A peak is found in the critical current I/sub c/(B) of metallic glass Cu(Ni)₃₃Zr₆₇ near its critical field B/sub c//sub =/. This peak corresponds to the negative magnetoresistance observed in the rho/sub f//rho/sub n/ versus B curve. After electrochemical polishing, both the peak in the critical current and the negative magnetoresistance disappeared. Scanning electron microscope observations show that the samples have sawtooth edges before polishing and smooth edges after polishing. Both effects are attributed to edge pinning. The pinning mechanism is discussed in this paper

[en] From the observations on bone marrow cell counts of femur, CFU-GM, CFU-S and the rate of larger hemopoietic colonies in histological sections of femur, it is shown that bone marrow stromal cells stimulated by irradiatoin obviously promote hemopoietic reconstruction in mice injuried by irradiation. Further studies show that the result is caused by stimulating effect of the stromal cells on the proliferation and differentiation capacity of hemopoietic system cells in bone marrow cells which were injected into recipient mice

No abstract available

[en] The effects of various laser conditions (frequency, intensity. Pulss-shape, magnetic component) on relativistic ionization probability of deuterium are studied. The results show that the ionization probability is increased with increasing laser intensity. But it is reduced with the laser frequency increasing. The effect of laser pulse-shape in no magnetic component is more obvious than one in existing magnetic component of laser will give some influences atomic ionization probability

[en] Criticality safety analysis for AP1000 spent fuel storage racks (SFSRs) employing burnup credit was recalculated based on SCALE6 code package. Combined with the design characteristics of AP1000 core reactivity control, the effect of axial burnup distribution on system reactivity was analyzed. The results show that the system reactivity is more conservative at high burnup using MSHIM axial burnup distribution, and the effect of neutron absorbers exposure on the reactivity of assembly during depletion should be considered in criticality safety analysis, and soluble boron should not be credited. (authors)

[en] The expression change of cellular senescence-associated genes is underlying the genetic foundation of cellular senescence. Using a suppressive subtractive hybridization system, we identified CSIG (cellular senescence-inhibited gene protein; RSL1D1) as a novel senescence-associated gene. CSIG is implicated in various process including cell cycle regulation, apoptosis, and tumor metastasis. We previously showed that CSIG plays an important role in regulating cell proliferation and cellular senescence progression through inhibiting PTEN, however, which domain or region of CSIG contributes to this function? To clarify this question, we investigated the functional importance of ribosomal L1 domain and lysine (Lys) -rich region of CSIG. The data showed that expression of CSIG potently reduced PTEN expression, increased cell proliferation rates, and reduced the senescent phenotype (lower SA-β-gal activity). By contrast, neither the expression of CSIG N- terminal (NT) fragment containing the ribosomal L1 domain nor C-terminal (CT) fragment containing Lys-rich region could significantly altered the levels of PTEN; instead of promoting cell proliferation and delaying cellular senescence, expression of CSIG-NT or CSIG-CT inhibited cell proliferation and accelerated cell senescence (increased SA-β-gal activity) compared to either CSIG over-expressing or control (empty vector transfected) cells. The further immunofluorescence analysis showed that CSIG-CT and CSIG-NT truncated proteins exhibited different subcellular distribution with that of wild-type CSIG. Conclusively, both ribosomal L1 domain and Lys-rich region of CSIG are critical for CSIG to act as a regulator of cell proliferation and cellular senescence. - Highlights: • The ribosomal L1 domain and lysine-rich region of CSIG were expressed. • They are critical for CSIG to regulate proliferation and senescence. • CSIG and its domains exhibit different subcellular distribution.