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Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and poses a severe threat to human health. Ginkgo biloba leaf polysaccharide (GBLP) is a bioactive component, and its sulphated derivative (sulfated GBLP, SGBLP) may exhibit high antitumor activity in certain types of cancers. However, the precise mechanisms of the SGBLP antitumor activity, particularly in HCC, remain unclear. Here, we assessed the effect of SGBLP on HepG2 hepatocellular carcinoma cells. SGBLP was shown to inhibit cellular proliferation and promote apoptosis through the regulation of pro- as well as anti-apoptosis markers, and to induce autophagy by supressing the PI3K/AKT/mTOR pathway. In addition, the autophagy inhibitor 3-melyladenine (3-MA) enhanced the antiproliferative and proapoptotic effects of SGBLP in HepG2 cells. Thus, SGBLP exhibits antitumor activity, and its combination with an autophagy inhibitor may represent a promising anticancer strategy in the treatment of HCC. [ABSTRACT FROM AUTHOR]

The prompt and delayed γ -ray spectra of 187Tl was studied via the 142Nd(50Cr, 3p2n)187Tl fusion-evaporation reaction at a beam energy of 255 MeV. An enhanced level scheme of 187Tl was established. The collective bands with one-quasiparticle configurations from the 2 f 7 / 2 , 1 h 9 / 2 , 1 h 11 / 2 and 1 i 13 / 2 orbitals and high-lying structures with possible three-quasiparticle configurations are investigated in terms of the tilted axis cranking covariant density functional theory. At low excitation energy, the rotational bands with one-quasiparticle configurations reflect coexistence of three shapes: prolate, triaxial, and oblate. The possible shapes of two microsecond isomers at high excitation energy are proposed. [ABSTRACT FROM AUTHOR]

To improve the efficiency of the discrete unified gas kinetic scheme (DUGKS) in capturing cross-scale flow physics, an adaptive partitioning-based discrete unified gas kinetic scheme (ADUGKS) is developed in this work. The ADUGKS is designed from the discrete characteristic solution to the Boltzmann-BGK equation, which contains the initial distribution function and the local equilibrium state. The initial distribution function contributes to the calculation of free streaming fluxes and the local equilibrium state contributes to the calculation of equilibrium fluxes. When the contribution of the initial distribution function is negative, the local flow field can be regarded as the continuous flow and the Navier–Stokes (N-S) equations can be used to obtain the solution directly. Otherwise, the discrete distribution functions should be updated by the Boltzmann equation to capture the rarefaction effect. Given this, in the ADUGKS, the computational domain is divided into the DUGKS cell and the N-S cell based on the contribution of the initial distribution function to the calculation of free streaming fluxes. In the N-S cell, the local flow field is evolved by solving the N-S equations, while in the DUGKS cell, both the discrete velocity Boltzmann equation and the corresponding macroscopic governing equations are solved by a modified DUGKS. Since more and more cells turn into the N-S cell with the decrease of the Knudsen number, a significant acceleration can be achieved for the ADUGKS in the continuum flow regime as compared with the DUGKS. [ABSTRACT FROM AUTHOR]

Osteoporosis is a complex multifactorial disease that can lead to an increased risk of fracture. However, selective and effective osteoporosis drugs are still lacking. We showed that Asperosaponin VI (AVI) has the implications to be further developed as an alternative supplement for the prevention and treatment of bone loss. AVI has been found to have beneficial effects on metabolic diseases such as bone loss, obesity, and atherosclerosis. Our study was designed to determine the effect and mechanism of action of AVI against bone loss through regulating microbial dysbiosis. A hindlimb unloading mouse model was established to determine the effect of AVI on bone microarchitecture, gut microbiota, and serum metabolites. Eighteen female C57BL/6 J mice were divided into three groups: control, hindlimb unloading with vehicle (HLU), and hindlimb unloading treated with AVI (HLU-AVI, 200 mg/kg/day). AVI was administrated orally for 4 weeks. The results demonstrated that AVI improved the bone microstructure by reversing the decrease in bone volume fraction and trabecular number, and the increase in trabecular separation and structure model index of cancellous bone in hindlimb suspension mice. The results of 16sRNA gene sequencing suggested that the therapeutic effect of AVI on bone loss may be achieved through it regulating the gut microbiota, especially certain specific microorganisms. Combined with the analysis of ELISA, immunohistochemistry, and serum metabolome results, it could be speculated that AVI played an important role in adjusting the balance of bone metabolism by influencing specific flora such as Clostridium and its metabolites to regulate the 5-hydroxytryptophan pathway. The study explored the novel mechanism of AVI against osteoporosis, and has implications for the further development of AVI as an alternative supplement for the prevention and treatment of bone loss. [ABSTRACT FROM AUTHOR]

Host–guest hybrid (HGH) consisting of p-But-calix[8]arene and fullerene C70 were fabricated with a facial solution deposition method. The as-prepared HGH samples are well periodic arranged in a layer structure, in which the interactions between the guest C70 and host p-Butcalix[8]arene molecules are van der Waals forces. High pressure Raman and UV–Vis absorption spectra studies on the HGH were recorded. Our results show that an orientational related phase transition and a one-dimensional (1D) polymerization of C70 molecules occur at about 2 and 7 GPa at room temperature, respectively. The band gap of the HGH translated synchronously with the change of structure upon compress. We suggest that the molecular confinement in such layer structure of the HGH restricts the polymerization of C70 molecules within a layer, which tunes the phase transition process of C70. This supplies a possible way to design fullerene-based functional materials at suitable conditions. [ABSTRACT FROM AUTHOR]

The low-cycle fatigue behavior of Sn-0.3Ag-0.7Cu-0.5CeO2 composite solder alloy was studied. The results show that the fatigue life exponent and material ductility coefficient of the composite solder alloy are dependent on both temperature and frequency. A modified Coffin-Manson model considering the influence of frequency and temperature was put forward, and the relationship between temperature and the frequency exponent, low-cycle fatigue life exponent, and material ductility coefficient was established. The modified model has a good elimination effect on the influence of different frequencies and temperatures on the low-cycle fatigue life of the composite solder alloy. [ABSTRACT FROM AUTHOR]

The femtosecond lasers were used to cut an ultra-sharp V-notch with a tip radius less than 0.5 μm on 3Y-TZP and Si3N4 ceramic samples. The KIc were measured accurately with the improved single-edge V-notched beam (SEVNB) method. The test results show that the true KIc of the 3Y-TZP is lower than that of the Si3N4 ceramic. However, the KIc measured by SENB method and the bending strength show that the mechanical property of 3Y-TZP is better than that of Si3N4 in the application without crack source. [ABSTRACT FROM AUTHOR]

Underground Nuclear Astrophysics Experiment in China (JUNA) takes the advantage of the ultra-low background in Jinping underground lab. High current mA level 400 KV accelerator with an ECR source, BGO and neutron detectors were commissioned. JUNA studies directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. In the first quarter of 2021, JUNA performed the direct measurements of 25 Mg (p , γ) 26 Al , 19 F (p , α) 16 O , 13 C (α , n) 16 O and 12 C( α , γ ) 16 O near the Gamow window. The experimental results reflect the potential of JUNA with higher statistics, precision and sensitivity of the data. The preliminary results of JUNA experiment and future plan are given. [ABSTRACT FROM AUTHOR]

Aquatic ecosystem is greatly affected by metal pollution and global climate change. Mercury (Hg) is one of the most common metal pollutants that pose harmful effects to organisms. In this study, we evaluated the effects of water temperature and Hg2+ on hematological parameters, such as red blood cells (RBCs), hematocrit (Ht) and hemoglobin (Hb) and some indexes involved in energy metabolism, including hexokinase (HK), pyruvate kinase (PK), malate dehydrogenase (MDH), lactate dehydrogenase (LDH), glucose (GLU), electron transport system (ETS) and Na–K-ATPase in grass carp, Ctenopharyngodon idella. Fish (45.37 ± 3.58 g) were acclimated to 15, 20, 25, 30 or 35 °C and co-exposed to 0.000 or 0.039 mg/L Hg2+ for 4 weeks. Three-way ANOVA revealed that all variables were significantly affected by water temperature, Hg2+ concentration, exposure time and their interactions, except the RBCs value corresponding Hg*Time condition. Based on the significant changes of hematological parameters in Hg2+-free groups, the best health status in fish was approximately at 25 °C, appreciating physiological dysregulation in fish under too low (15 °C)/high (35 °C) temperature, especially at 35 °C. Although our data provide evidences that increased temperatures can potentiate Hg2+ toxicity, the combined effects of temperature and metals on aquatic organisms are complex and unpredictable, so we should not ignore the role of environmental factors (such as temperature) while evaluating the harmful effects of metals on aquatic ecosystem. [ABSTRACT FROM AUTHOR]

To enable broader applications of magnesium alloy sheets, one requirement is to achieve comparable strength-formability balance with that of aluminum-based alloys. Based on the review of recent studies on precipitation hardening of microalloyed magnesium alloys, we propose the usage of age-hardenable alloys to overcome the strength-formability trade-off in magnesium alloy sheets. Precipitation hardening has not been actively used in commercial wrought magnesium alloys because of their poor age-hardening responses. However, recent studies have shown appropriate selection of microalloying elements leads to a substantial enhancement of the kinetics of age-hardening. We found Mg-Ca-X (X = Al, Zn) dilute alloys show promising age-hardening characteristics for bake-hardenable alloy sheets that may be used as a substitute for 6xxx aluminum alloy sheet for weight reduction. Such alloys show excellent room temperature stretch formability, and substantial strengthening to ~240 MPa can be achieved by a short-term aging at low temperatures: 170°C for 20 min. [ABSTRACT FROM AUTHOR]

Accurate characteristic of structural surfaces roughness at the relevant scale is very important to understand mechanical properties of rock mass discontinuities. So, a systematic investigation has been carried out to understand the effect of scale on the structural surface roughness by fractal dimension method. Firstly, considering the shortcoming of the projective covering method (PCM), we improved this method based on stochastic approach. Secondly, to investigate the size effect of the structural surface roughness, we selected six sampling windows, respectively, from the central and four corners part of structural planes (2 m × 2 m). The sampling windows range from 62.5 mm × 62.5 mm to 2000 mm × 2000 mm. And then, we calculated fractal parameters of the different size surfaces using improved projective covering method (IPCM) at the same resolution. Thirdly, we discussed a new method of determining reasonable size of structural surfaces by the parameter Δ D max SD . This parameter is difference of the maximum fractal dimension of the same size structural surface in different regions. The results show that: (1) The size effect of structure surfaces is different with different morphological surface. Generally, as the size increases, the roughness of structure surfaces increases and then decreases. There is positive size effect in small scale and negative size effect in large scale. (2) For a given structural surface, when the same size surfaces are selected from different locations of the structural planes, and the size effect characteristics are also different. (3) As the size of structure surfaces increases, the parameter Δ D max SD gradually decreases and tends to almost constant. The result of this study is a useful supplement to the comprehensive understanding of the size effect of structural surfaces roughness. [ABSTRACT FROM AUTHOR]

As an effective energy-absorbing cable, constant resistance large deformation (CRLD) cables have been widely applied in rock engineering projects; however, to the best of our knowledge, its interaction mechanism with the surrounding rock has never been studied. According to previous practical projects, the CRLD cable–rock interaction differs from that of conventional cables because of the tubular expansion during the CRLD process, and it influences the performance of the cable reinforcement system. Therefore, an attempt was made to investigate the characteristics of the CRLD cable–rock interaction under static pull-out loading by using a coupled numerical method. The structure of the CRLD cable was modelled via the finite-difference method, and the surrounding rock was modelled via the discrete-element method. The micro-parameters of the surrounding rock were carefully calibrated, and the macro-parameters of the CRLD cable were verified by comparing them with a corresponding experimental test in the laboratory. The numerical results were carefully analysed. The constant resistance forces of a single CRLD cable and a CRLD cable reinforcement system were compared. The distribution of the normal and shearing stresses on the cable–rock interface was obtained, and the evolution mode of the pull-out strength was examined. In addition, the failure mode of the grouting material and surrounding rock was studied on a micro-scale. The findings describe the interaction of the CRLD cable against the surrounding rock, reveal its special anchorage mechanism, and can be used to predict and improve the performance of the CRLD cable reinforcement system. [ABSTRACT FROM AUTHOR]

The use of accelerated beams of electrons, protons or ions has furthered the development of nearly every scientific discipline. However, high-energy muon beams of equivalent quality have not yet been delivered. Muon beams can be created through the decay of pions produced by the interaction of a proton beam with a target. Such 'tertiary' beams have much lower brightness than those created by accelerating electrons, protons or ions. High-brightness muon beams comparable to those produced by state-of-the-art electron, proton and ion accelerators could facilitate the study of lepton–antilepton collisions at extremely high energies and provide well characterized neutrino beams1–6. Such muon beams could be realized using ionization cooling, which has been proposed to increase muon-beam brightness7,8. Here we report the realization of ionization cooling, which was confirmed by the observation of an increased number of low-amplitude muons after passage of the muon beam through an absorber, as well as an increase in the corresponding phase-space density. The simulated performance of the ionization cooling system is consistent with the measured data, validating designs of the ionization cooling channel in which the cooling process is repeated to produce a substantial cooling effect9–11. The results presented here are an important step towards achieving the muon-beam quality required to search for phenomena at energy scales beyond the reach of the Large Hadron Collider at a facility of equivalent or reduced footprint6. Ionization cooling, a technique that delivers high-brightness muon beams for the study of phenomena at energy scales beyond those of the Large Hadron Collider, is demonstrated by the Muon Ionization Cooling Experiment. [ABSTRACT FROM AUTHOR]

A new experimental method on simulating the combined action of cavitation erosion and abrasion was proposed to investigate the erosion mechanism of overflow structure induced by the said processes. An automatic sand mixing device was invented for high-pressure and high-speed flow based on the characteristics of Venturi cavitation generator and hydraulic Bernoulli principle. The experimental system for the combined action of cavitation erosion and abrasion was designed and constructed, and high-speed sand mixing flow only appeared in the test section. A series of tests on the combined and single action of cavitation erosion and abrasion on hydraulic concrete and cement was carried out by using the invented experimental device. Results show that the wear of concrete surface exhibited the combined characteristics of cavitation erosion and abrasion under their joint action. The damage degree of concrete surface under the combined action was more severe than that under a single action. The mass loss of concrete under the combined action was higher than sum of mass losses of concrete under two single actions. The promotion and enhancement between cavitation erosion and abrasion existed in high-speed sand mixing flow. A power exponential relationship was observed between erosion mass loss and flow speed, and the velocity indexes approximated 4.5. Small and light sand particles easily follow water flow. Thus, the strong coupling effect of cavitation erosion and abrasion resulted from the presence of small sand particles. Given the different mechanisms of cavitation erosion and abrasion, presenting the skeleton structure formed by cavitation erosion was notably difficult under the action of abrasion. Meanwhile, abrasion wear easily occurred under the impact of cavitation erosion, and this result is due to the mechanism of the combined action of both processes. [ABSTRACT FROM AUTHOR]

Flow-type landslides are an important hazard that can cause great destruction due to the rapid flow velocity and large disaster area. This paper presents a catastrophic flowslide that recently occurred at a landfill in Shenzhen, China. This disaster involved an area about 1100 m in length and 630 m in maximum width, and caused the death of 77 people and the destruction of 33 buildings. The precise reason for the landfill’s failure is still unknown, and therefore we try to contribute an increased understanding of the event for future prevention. In this study, the failure mechanism of the studied slope was analyzed and described under partially saturated condition. The solid-fluid transition during the flowslide occurrence was described using a unified constitutive model. The model was used to perform the hydro-elasto-plastic modeling in the pre-failure stage, the viscous modeling in the post-failure stage, and the second-order work criterion was introduced in between to model the solid-fluid transition. The consistent evolution of the flowslide, including initiation, propagation, and deposit stages, was simulated and analyzed using the finite element method with Lagrangian integration points after careful calibration of the viscous parameters. The numerical results were compared with the real case and used to explain the failure mechanism. [ABSTRACT FROM AUTHOR]

Study design:A retrospective comparative study.Objectives:To compare clinical outcomes of surgery or non-operated treatment for mild cervical spondylotic myelopathy (CSM) patients with intramedullary increased signal intensity (ISI) on T2-weighted imaging (T2WI) of magnetic resonance imaging (MRI), related factors that may affect prognosis were explored.Methods:Data from 91 patients treated from July 2008 to June 2011 were retrospectively analyzed. The Japanese Orthopedic Association (JOA) recovery ratio was used to compare outcomes of surgery and non-operated treatment. Correlation and multiple linear regression analyses were performed between JOA recovery ratio and age, disease course, segmental lordosis, total range of motion (ROM), segmental ROM, local slip, extent of spinal cord compression or ISI type.Results:Patients were divided into two groups by therapy methods: Group A (n=53, 33 males, age 36-68 years) underwent anterior cervical decompression and fusion surgery, average follow-up 30.68±8.19 months; Group B (n=38, 14 males, age 28-76 years) received non-operated treatment, average follow-up 34.08±9.05 months. There were no significant differences in clinical outcomes between the two groups. There were significant correlations between JOA recovery ratio and clinical course (P<0.01) or segmental lordosis (P<0.01). Patients with shorter disease course and larger segmental lordosis have better clinical outcomes as shown by multiple linear regression analysis.Conclusion:For mild CSM patients with ISI on T2WI-MRI, there are no significant differences in clinical outcome between surgery and non-operated treatment during the short-term follow-up. Patients with shorter disease course and larger segmental lordosis have better clinical outcomes than those with longer course and segmental kyphosis. [ABSTRACT FROM AUTHOR]

Monte Carlo method has been performed to simulate the structure evolution of Ni-Cu alloy nanorods encapsulated in the carbon nanotube and removed from the carbon nanotube. The Sutton-Chen many-body potential and Lennard-Jones potential are used to describe the metal-metal and metal-carbon interactions, respectively. The studies show that all Ni-Cu atoms in carbon nanotube are arranged in a series of concentric cylindrical layers even they have different fractions, and Cu atoms are apt to stay at the surface layers. If the carbon nanotube was removed, Ni-Cu alloy nanorod would turn into a cluster with nickel core and copper shell. The physical origin for such structure formation and evolution toward core-shell motifs are discussed. The bond pair analysis shows that the nanorods and clusters are amorphous structures dominated by the rhombohedral structure and mixed up with some local short-range order. [ABSTRACT FROM AUTHOR]

We in this paper provide a sine-Gordon model of (1+1)-dimensions in which macroscopic quantum coherence of domain walls may be observed. The tunneling amplitude in field models of (1+1)-dimensions, such as sine-Gordon, is negligible small at zero temperature. In the long, but finite-length chain at finite temperature it is possible to have a finite, but still very small one. In the present model of the antiferromagnetic spin chain with biaxial anisotropy in an external magnetic field, in which the height of the sine-Gordon barrier can be tuned, the tunneling amplitude is shown to be enhanced by adjusting the external parameter. [ABSTRACT FROM AUTHOR]

In order to investigate the possible influence of metallic environment on the alpha decay process, we have measured the Sm activities in the hosts of metal samarium and SmO . The Sm half-life was found to be (1.06±0.01)×10 y in metal samarium and (1.07±0.01)×10 y in SmO , respectively. No significant change has been observed within the experimental uncertainty. The absolute half-life presented here is consistent with the recommended value. [ABSTRACT FROM AUTHOR]

The characteristics of optical-wave target detection and imaging from a negative-refraction photonic crystal (NR-PC) flat lens are studied with a two-dimensional (2D) finite-difference time-domain (FDTD) method in the paper. The results show that there exists a transmission peak, with a value far greater than unit, resulting from the influence of the mini-forbidden bands and resonance excitation effect at resonance frequency. Also, the refocusing of backscattered optical wave from the target leads to its image with a sub-wavelength lateral resolution and great amplitude as long as the target is placed at the focus of the NR-PC flat lens. Therefore, the NR-PC flat lens will find many implications in optical area, especially in the detection and imaging of small targets. [ABSTRACT FROM AUTHOR]

Nanometer manganese dioxide spheres were prepared by water/oil microemulsion technology using sodium pyrosulfite and potassium permanganate as the raw materials. The scanning electron microscopy and the transmission electron microscopy images showed that the as-prepared MnO2 particles aggregated with many nanosize spheres with an average diameter about 100 nm. From the X-ray diffraction patterns, it suggested that the achieved materials had the crystal structure of α-MnO2. The electrochemical properties of the nanometer MnO2 spheres doped with various amounts of Cr2O3 were studied in detail in this paper. The results revealed that the MnO2 particles doped with 4 wt.% Cr2O3 can maintain more than 150 mAh g−1, which is about 84% of the initial specific capacity, even after 50 cycles indicating a promising application in the rechargeable lithium batteries. [ABSTRACT FROM AUTHOR]

The angular distribution of the 2H ( 6He,7Li n reaction was measured with a secondary 6He beam of 36.4MeV for the first time. The proton spectroscopic factor of 7Li ground state was extracted to be 0.42±0.06 by normalizing the calculational differential cross-sections with the distorted-wave Born approximation to the experimental data. It was discussed that the uncertainty of extracted spectroscopic factors from the one-nucleon transfer reactions induced by deuteron might be reduced by determining the volume integrals of imaginary optical potentials precisely. [ABSTRACT FROM AUTHOR]

AimTo evaluate the effectiveness of combined lasers with different wavelengths in creating chorioretinal venous anastomosis (CRVA) in nonischaemic central retinal vein occlusion (CRVO).MethodsIn this retrospective, noncomparative, consecutive case series, records of all patients with a diagnosis of nonischaemic CRVO who underwent combined laser treatment to induce CRVA and who were followed-up for 6 months or longer were reviewed.ResultsRecords of 85 patients (85 eyes) were analysed. These patients were divided into two groups. In group 1 (24 cases, 24 eyes), combined lasers with two different wavelengths (argon blue–green laser combined with Nd–YAG laser were used. In group 2 (61 cases, 61 eyes), combined lasers with three different wavelengths (argon blue–green laser combined with krypton red laser and Nd–YAG laser) were used. Functional anastomosis formed in 13 out of 24 eyes (54%) in group 1 and 47 out of 61 eyes (77%) in group 2. In patients with successful anastomosis, visual acuity improved for two or more lines in 49 out of 60 eyes (82%), with the remaining eyes undergoing no change. There were no serious complications.ConclusionThe use of three laser wavelengths results in the creation of laser anastomosis and the success rate may be higher than when using two wavelengths alone.Eye (2007) 21, 962–967; doi:10.1038/sj.eye.6702362; published online 19 May 2006 [ABSTRACT FROM AUTHOR]

The importance of diseases of tomato caused by begomoviruses is increasing worldwide. Here, we report that several begomoviruses are associated with tomato leaf curl disease in Yunnan province, China. 14 tomato samples showing leaf curl symptoms were collected in three districts in Yunnan, and they fell into four groups according to their reaction with a panel of 16 monoclonal antibodies in TAS-ELISA. Comparison of partial DNA-A sequences amplified with degenerate primers confirmed the existence of several types of begomoviruses. The complete DNA-A sequences of 4 isolates (Y25, Y41, Y72, Y161), corresponding to the four groups, were determined. Sequence comparisons and phylogenetic analysis revealed that they corresponded to four previously identified begomoviruses. Groups I, II and IV are most closely related toTomato yellow leaf curl China virus(TYLCCNV),Tobacco curly shoot virus(TbCSV) andTobacco leaf curl Yunnan virus(TbLCYNV), respectively, while Group III shows close relationships withTomato yellow leaf curl Thailand virus(TYLCTHV). In addition, all isolates in Groups I and III were found to be associated with DNAß molecules, while satellite DNA was not found in virus isolates in Groups II and IV. The complete DNAß sequences of three isolates from Group III (Y72, Y77, Y79) were determined. Sequence analysis showed that Y72ß, Y77ß and Y79ß seem to be different from other characterised DNAß, sharing the highest nucleotide sequence identity with DNAß of TbCSV. [ABSTRACT FROM AUTHOR]

The effect of nonlinear gradient terms on the pulsating, erupting and creeping solitons, respectively, of the cubic–quintic complex Ginzburg–Landau equation is investigated. It is found that the nonlinear gradient terms result in dramatic changes in the soliton behavior. They eliminate the periodicity of the pulsating and erupting solitons and transform them into fixed-shape solitons. This is important for potential use, such as to realize experimentally the undistorted transmission of femtosecond pulses in optical fibers. However, the nonlinear gradient terms cause the creeping soliton to breathe periodically at different frequencies on one side and spread rapidly on the other side. [ABSTRACT FROM AUTHOR]

Summary. The interaction of an edge dislocation with an inclusion of arbitrary shape is analyzed based on the Eshelby equivalent inclusion method. A general solution to determine the force on the dislocation is obtained, from which a set of simple approximate formulae is also suggested. [ABSTRACT FROM AUTHOR]

Our previous studies have demonstrated that retrovirus-mediated gene transduction of either the human erythropoietin receptor (EpoR) or H-ras cDNA into single purified hematopoietic progenitor (HPC), CD343+, cells from cord blood (CB) resulted in increased numbers and sizes of erythroid cell containing colonies. We therefore evaluated if there were further effects when H-ras and EpoR genes were co-transduced into the same progenitor cells. Highly purified single sorted CD343+ CB cells were transduced with retroviral vectors encoding EpoR or H-ras cDNA. At the single cell level, and in response to stimulation by a combination of growth factors, including Epo, the number of colonies formed by BFU-E and CFU-GEMM was significantly increased in cells transduced with either single H-ras or EpoR cDNA compared to mock virus-transduced cells as previously described. Increased numbers of BFU-E, but not CFU-GEMM, colonies were produced from cells simultaneously co-transduced with both EpoR and H-ras genes. Little or no growth was seen in transduced cells without exogenously added cytokines. The size of all types of colonies including CFU-GM was increased in cells transduced with H-ras and/or EpoR cDNAs, and the greatest increase was noticed in cells co-transduced with both genes. Integration and expression of either gene in individual colonies as assessed by PCR and RT-PCR analysis were 45–62% and 48–58%, respectively, with approximately 31% of the cells containing and expressing both genes. These results add to information suggesting an enhancing interacting role of H-ras and EpoR in erythroid proliferation/differentiation. Bone Marrow Transplantation (2000) 26, 817–822. [ABSTRACT FROM AUTHOR]

Summary. Bluetongue virus (BTV) infection of ruminants is endemic throughout tropical and subtropical regions of the world. The S7 gene segments of prototype Chinese strains of BTV serotypes 1, 2, 3, 4, 12, 15, and 16 were sequenced and compared to the same genes of prototype strains of BTV from the US, Australia, and South Africa. The S7 genes and predicted VP7 proteins of the Chinese viruses were relatively conserved, with the notable exception of serotype 15. Furthermore, phylogenetic analysis of the S7 genes did not predict geographic origin of the various strains of BTV. [ABSTRACT FROM AUTHOR]

Macrophage-stimulating protein (MSP), originally identified as an inducer of murine resident macrophage responsiveness to chemoattractants, is a ligand for human RON/murine STK receptor protein tyrosine kinases. Since STK was cloned from populations enriched for hematopoietic stem cells, we initiated studies on the effects of MSP on colony formation by granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) myeloid progenitor cells. MSP alone had no colony stimulating activity. However, MSP caused about a 50% suppression of CFU-GM colony formation induced by synergistic combinations of SLF or Flt-L plus GM-CSF, G-CSF, or IL-3 and of BFU-E and CFU-GEMM colonies induced by SLF or Flt3-L plus Epo or Epo and IL-3. In contrast, MSP had no effect on progenitors stimulated by one growth factor. MSP also suppressed colony formation by stimulated cord blood progenitors, but only after preinduction to a rapidly cycling state. It was previously reported that several members of the chemokine family synergistically suppress myeloid progenitor proliferation. Likewise, synergistic suppression was observed when MSP was paired with VEGF, MIP-1 alpha, IL-8, PF4, MCP-1, IP-10, or ENA-78, or when VEGF was paired with the chemokines; and the required MSP concentration was more than 100-fold less than for MSP alone. Additionally, MSP or VEGF inhibited proliferation of the human myeloid growth factor-dependent cell line, M07e, but a sustained effect required multiple additions over time. At the least, some of the MSP suppressive effects on myeloid progenitors, as assessed on single isolated CD34 marrow cells, appeared to be directly on the progenitors; sustained additions of MSP were required to see this effect. The suppressive action of MSP and its synergism with proteins of the chemokine family may be of relevance to regulation of blood cell production. [ABSTRACT FROM AUTHOR]

Varicella-zoster virus glycoproteins were purified by using monoclonal antibodies and analyzed for their effects on cell-free virus infection. Preinfection treatment of cells with gH:gL reduced the infection efficiency and increased the number of unadsorbed virus. Postinfection treatment of cells with gB increased the infection efficiency, but that with gE:gI reduced it. Treatment of gE:gI and gH:gL with neuraminidase (NA) abolished their inhibitory activity and the plaque formation was enhanced by NA treatment of glycoproteins and cells. Glycoproteins exhibited their diverse activities despite their common role in viral penetration, and sialyl residues were responsible for their function in cell-free virus infection. [ABSTRACT FROM AUTHOR]

The femtosecond lasers were used to cut an ultra-sharp V-notch with a tip radius less than 0.5 μm on 3Y-TZP and Si3N4 ceramic samples. The KIc were measured accurately with the improved single-edge V-notched beam (SEVNB) method. The test results show that the true KIc of the 3Y-TZP is lower than that of the Si3N4 ceramic. However, the KIc measured by SENB method and the bending strength show that the mechanical property of 3Y-TZP is better than that of Si3N4 in the application without crack source. [ABSTRACT FROM AUTHOR]

Using the improved arc-discharge equipment, we selected graphite as electrode and prepared the multi-walled carbon nanotubes in an atmosphere of pure NH3 at pressure of 0.02 MPa and discharge current of 70 A by the arc-discharge method. The influence of NH3 atmosphere on the growth and structure of carbon nanotubes was studied. By analyzing transmission electron microscope and scanning electron microscope micrographs, we found that a large quantity of multi-wall carbon nanotubes can be grown on the top surface and in the inner of interlayer between central part and outer part in the cathode deposits. The results show that there is no significant difference of the shapes and the structures between NH3 atmosphere and other atmosphere such as He, H2, et al., except their positions. This study demonstrates that the arc-discharge method in NH3 atmosphere is one highly efficient method in the preparation of carbon nanotubes. [ABSTRACT FROM AUTHOR]

A new method to produce large quantities of single-walled carbon nanotubes (SWCNTs) with high purity is developed. Using several composite graphite rods containing Y and Ni powder as the anode, and a high purity graphite hemisphere as the cathode, a cloth-like deposit could be obtained by dc arc-discharge in helium at high temperature. The deposit contained about 50% SWCNTs. In this way, more than one gram deposit could be produced in a few minutes. The structure and morphology of the SWCNTs were then examined using transmission electron microscopy, Raman spectroscopy, and thermogravimetric analysis. [ABSTRACT FROM AUTHOR]

Effects of an AlN passivation layer on the microstructure and electronic properties of AlGaN/GaN heterostructures were investigated by X-ray diffraction and Hall effect measurements. AlN passivation induced an additional compressive stress in an AlGaN barrier layer instead of an additional tensile stress induced by Si3N4 passivation. The change of strain after passivation contributes in a relatively small proportion to the variation of the carrier concentration in AlGaN/GaN heterostructures compared with the contribution from passivation of surface traps. The results from Hall effect measurements show that the AlN passivation layer has a better effect on passivation of deep levels than the Si3N4 film and also results in a remarkable increase in mobility of the two-dimensional electron gas. [ABSTRACT FROM AUTHOR]