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Oridonin, an ent-kaurene diterpenoid isolated from the traditional Chinese herb Rabdosia rubescens, has been reported to be a potent cytotoxic agent against a wide array of cancer cells. However, its effect on human nasopharyngeal carcinoma (NPC) cells has not been well investigated. The present study aimed to explore the anti-tumour effect of oridonin in NPC cells and its underlying mechanisms. Cell viability was examined by 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyl-tetrazolium bromide assay and colony formation assay. Apoptosis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and expression of apoptosis-related proteins were analysed by flow cytometry with propidium iodide staining, JC-1 staining, DCFH-DA staining, and Western blot analysis, respectively. The results showed that oridonin concentration-dependently inhibited the cell viability, decreased the colony formation, and enhanced the apoptotic rate in NPC cells. Further, oridonin-induced apoptosis was mediated by the mitochondrial pathway in NPC cells, which was confirmed by the loss of MMP, downregulation of anti-apoptotic Bcl-2 family protein Mcl-1 and Bcl-2, upregulation of pro-apoptotic Bcl-2 family member Bax, and activation of caspase-3 and PARP. Notably, the augmented ROS generation played an essential role in oridonin-induced apoptosis in NPC cells, as the apoptosis-inducing effect was attenuated by ROS scavenger N-acetyl-L-cysteine. These results indicate that oridonin triggers apoptosis through the ROSmediated mitochondrial pathway in NPC cells. This study supports oridonin to be an interesting candidate drug for the treatment of human NPC. [ABSTRACT FROM AUTHOR]

Magnetoelectric materials which simultaneously exhibit electric polarization and magnetism have attracted more and more attention due to their novel physical properties and promising applications for next-generation devices. Exploring new materials with outstanding magnetoelectric performance, especially the manipulation of magnetization by electric field, is of great importance. Here, we demonstrate the cross-coupling between magnetic and electric orders in polycrystalline Co4Nb2O9, in which not only magnetic-field-induced electric polarization but also electric field control of magnetism is observed. These results reveal rich physical phenomenon and potential applications in this compound. [ABSTRACT FROM AUTHOR]

We developed an approach to assess environmental flows in estuaries related to preference of phytoplankton considering the complex relationship between hydrological modification and biomass in ecosystems. As a first step, a relationship was established between biomass requirements for organisms of primary and higher nutritional levels based on the principle of nutritional energy flow of ecosystem. Then, diagnostic pigments were employed to represent phytoplankton community biomass, which indicated competition between two groups of phytoplankton in the biochemistry process. Considering empirical relationships between diagnostic pigments and critical environmental factors, responses of biomass to river discharges were established based on a convection-diffusion model by simulating distributions of critical environmental factors under action of river discharges and tide currents. Consequently, environmental flows could be recommended for different requirements of fish biomass. In the case study in the Yellow River estuary, May and October were identified as critical months for fish reproduction and growth during dry years. Artificial hydrological regulation strategies should carefully consider the temporal variations of natural flow regime, especially for a high-amplitude flood pulse, which may cause negative effects on phytoplankton groups and higher organism biomass. [ABSTRACT FROM AUTHOR]

Our previous results showed that kisspeptin-10 (Kp-10) injections via intraperitoneal (i.p.) once daily for three weeks notably promoted the egg laying rate in quails. In order to investigate the mechanism behind the effects of Kp-10 on enhancing the egg laying rate in birds, this study focused on the alternations of lipids synthesis in liver after Kp-10 injections. 75 female quails (22 d of age) were allocated to three groups randomly, and subjected to 0 (control, Con), 10 nmol (low dosage, L) and 100 nmol (high dosage, H) Kp-10 injections via i.p. once daily for three weeks, respectively. At d 52, quails were sacrificed and sampled for further analyses. Serum E2 concentration was increased by Kp-10 injections, and reached statistical significance in H group. Serum triglyceride (TG) concentrations were increased by 46.7% in L group and 36.8% in H group, respectively, but did not reach statistical significance, and TG contents in liver were significantly elevated by Kp-10 injections in a dose-dependent manner. Serum total cholesterol (Tch) concentrations significantly decreased in H group, while in H group the hepatic Tch content was markedly increased. The level of non-esterified fatty acid (NEFA), apolipoprotein A1 and B (apoA1 and apoB) were not altered by Kp-10 injections. The genes expression of sterol regulatory element binding protein-1 (SREBP-1), fatty acid synthetase (FAS), apolipoprotein VLDL-II (apoVLDL-II), cholesterol 7α-hydroxylase (CYP7A1) and vitellogenin II (VTG-II) were significantly up-regulated by high but not low dosage of Kp-10 injection compared to the control group. However, the expression of SREBP-2, acetyl-CoA carboxylase (ACCα), malic enzyme (ME), stearoyl-CoA (Δ9) desaturase 1 (SCD1), apolipoprotein A1 (apoA1), fatty acid binding protein 2 (FABP2), 3-hydroxyl-3-methyl glutaryl-coenzyme A reductases (HMGCR), estrogen receptor α, β (ERα and β) mRNA were not affected by Kp-10 treatment. In line with hepatic mRNA abundance, hepatic SREBP1 protein content was significantly higher in H group. Although the mRNA expression was not altered, the content of ERα protein in liver was also significantly increased in H group. However, SREBP-2 protein content in liver was not changed by Kp-10 treatment. In conclusion, exogenous Kp-10 consecutive injections during juvenile stage significantly advanced the tempo of egg laying in quails, which was associated with the significant elevation in hepatic lipids synthesis and transport. [ABSTRACT FROM AUTHOR]

For materials with small size of the discontinuities of the free energy derivatives at transition, it is not so easy to determine the order of the transition using the criterion of the Arrott plot. In our previous paper, we found that the Mn2–xFexP0.6Si0.25Ge0.15 compounds with x = 0.7 and 0.8 undergo first-order phase transitions but apparently shows some characteristics of a second-order phase transition. In this paper, we have employed the Arrott plot and entropy change scaling to analyse the nature of the transitions for those compounds. The results reveal that the use of entropy change scaling is more effective than the Arrott plot for determining the nature of the transition in such materials. [ABSTRACT FROM AUTHOR]

To investigate the effect of glucocorticoid on adipocytes metabolism and miRNAs that may be involved in adipocyte diff erentiation, primary porcine preadipocytes were treated with 10 - 6 M dexamethasone and RU486 (a glucocorticoid receptor antagonist) for 48 h. PPAR-γ (peroxisome proliferators-activated receptor-γ), and C/EBP-β (CCTTA enhancer binding protein-β) gene and protein expression were measured. The expressions of miRNAs predicted to directly target C/EBP-β were determined, and the functions of the potential miRNAs were verified. The results showed that the triglyceride content in cultured adipocytes increased significantly after 10 - 6 M dexamethasone treatment for 48 h, whereas the cell viability did not differ among the 4 groups (Control: 10 - 6 M dexamethasone; 10 - 6 M RU486: 10 - 6 M dexamethasone + 10 - 6 M RU486) (p > 0.05). Cells treated with dexamethasone for 48 h significantly upregulated perilipin and PPAR-γ gene expression, and PPAR-γ protein expression was also significantly increased. However, C/EBP-β mRNA and protein expression levels were significantly decreased. Both miR-374a and miR-374b, targeting the C/ EBP-β 3'-UTR (3'-untranslated region), were significantly increased. Dual luciferase activity assay results indicated that miR-374a/b was directly recognised and bound to the 3'-UTR of C/EBP-β and thereby suppressed C/EBP-β gene expression. The present study showed that 10 - 6 M dexamethasone promotes lipid accumulation in primary cultures of porcine preadipocytes. PPAR-γ and C/EBP-β protein abundance showed differences after 48 h dexamethasone treatment; miR-374a/b may be involved in regulating of C/ EBP-β expression. These results provide new targets for further regulation of porcine lipid metabolism. [ABSTRACT FROM AUTHOR]

This study investigated the adsorption of the heavy-metal ions Cu(II) and Pb(II) onto a lignin derivative. The lignin derivative was obtained by treating bagasse soda lignin with epichlorohydrin, and subsequently grafting an amine functional group by the Mannich reaction. The morphology of aminated epoxy-lignin was a layered structure with pores characterized by SEM. The heavy-metal ion adsorption data could be described well with the pseudo-first order model for Pb(II) ion and the pseudo-second order model for Cu(II) ion; diffusion was found to be the rate-limiting step when approaching equilibrium. FTIR spectroscopy was used to study the mechanism of heavy-metal adsorption by the derivatized lignin. The results show that the sites for adsorption are related to hydroxyl and amido groups. [ABSTRACT FROM AUTHOR]

Somatic cell nuclear transfer and transcription-factor-based reprogramming revert adult cells to an embryonic state, and yield pluripotent stem cells that can generate all tissues. Through different mechanisms and kinetics, these two reprogramming methods reset genomic methylation, an epigenetic modification of DNA that influences gene expression, leading us to hypothesize that the resulting pluripotent stem cells might have different properties. Here we observe that low-passage induced pluripotent stem cells (iPSCs) derived by factor-based reprogramming of adult murine tissues harbour residual DNA methylation signatures characteristic of their somatic tissue of origin, which favours their differentiation along lineages related to the donor cell, while restricting alternative cell fates. Such an 'epigenetic memory' of the donor tissue could be reset by differentiation and serial reprogramming, or by treatment of iPSCs with chromatin-modifying drugs. In contrast, the differentiation and methylation of nuclear-transfer-derived pluripotent stem cells were more similar to classical embryonic stem cells than were iPSCs. Our data indicate that nuclear transfer is more effective at establishing the ground state of pluripotency than factor-based reprogramming, which can leave an epigenetic memory of the tissue of origin that may influence efforts at directed differentiation for applications in disease modelling or treatment. [ABSTRACT FROM AUTHOR]

We have tested an approach to identify putative cancer stem cells that involves measurement of the infrared absorption spectrum of individual cells in an aqueous environment, and their subsequent classification using multivariate data analysis techniques. Two primary esophageal cell lines were characterized: the immortalized normal esophageal epithelial cell line, Het-1A, and the esophageal adenocarcinoma cell line, OE33. In addition, we also evaluated spheroids, reflecting stem-like cell populations, which were derived from each parent cell line when grown in serum-free media. As differences in cell size appeared to be a strong discriminating factor, a correction needs to be performed to allow a reliable classification based on infrared absorption spectra. We demonstrated that stem-like cells derived from Het-1A could easily be discriminated on the basis of absorbance differences in the 1000–1200 cm−1spectral interval, whereas this was not possible for OE33. Furthermore, we found that changes due to aging of OE33 cells in culture dominated the infrared absorption spectra and somewhat limited the potential of this approach to identify stem-like cell populations using this in vitromodel system. [ABSTRACT FROM AUTHOR]

Quantum memories for the storage and retrieval of quantum information are extremely sensitive to environmental influences, which limits their storage times. The ground states of atoms and ions are potential candidates for quantum memories, but although coherence times of the order of a few seconds for atoms and hundreds of seconds for ions have been demonstrated, long-lived storage and retrieval of single quantum excitations remains an outstanding challenge. Here, we report a quantum memory using the magnetically insensitive clock transition in atomic rubidium confined in a one-dimensional optical lattice. We observe quantum memory lifetimes exceeding 6 ms, more than two orders of magnitude longer than previously reported. This advance is an important step towards the realization of long-distance quantum networks and the controlled production of complex entangled states of matter and light. [ABSTRACT FROM AUTHOR]

Polarized absorption spectra of Nd:LuVO4 crystal were measured at room temperature. The optical parameters of π polarization and σ polarization were calculated by Judd-Ofelt theory. Meanwhile, the phenomenological intensity parameters: Ω2, Ω4, and Ω6 were obtained, then the parameters were used to calculate the luminescence parameters of Nd:LuVO4 crystal, including oscillator strengths, fluorescence branching ratio, radiative lifetime and integrated emission cross-sections. Experiments of a-cut and c-cut Nd:LuVO4 lasers were also performed, and opt-opt conversion efficiency and slope efficiency were 40.3%, 50.5% for a-cut and 23.6%, 30.9% for c-cut, respectively. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

The heterostructure of Pt/Ba0.5Sr0.5TiO3/La0.67Sr0.33MnO3 (Pt/BST/LSMO) with the BST thickness ranging from 120 to 550 nm was fabricated by pulsed laser deposition. The dielectric constant (ɛ) of the heterostructure was measured under different electrical fields (E) and frequency (f). A strong thickness dependence of the value of ɛ, the ɛ–E dependence and the ɛ–f dependence were observed, which can be well explained by the series-capacitor model, based on the assumption that the heterostructure electrically consists of a ‘bulk’ layer and an interfacial layer between the Pt and BST layers. The dielectric properties of the ‘bulk’ layer and the interface layer were obtained. At room temperature, the dielectric constant of the ‘bulk’ layer was 1204 (at 100 kHz) and had a power law dependence on frequency. The ratio of thickness over the dielectric constant (di/ɛi) of the interface layer, which was used to characterize the property of the Pt/BST interface, was found to be around 0.08 nm at room temperature and to be independent of frequency. [ABSTRACT FROM AUTHOR]

(1 0 0), (1 1 0) and (1 1 1) LaAlO3/SrTiO3 (LAO/STO) interfaces show similar high mobility conduction. Here, we compare electronic transport and photoconductivity properties of electron gases at the three interfaces, considering their different polar continuity at the interface and the crystallographic symmetry. Epitaxial LAO films were grown on STO (1 0 0), (1 1 0) and (1 1 1) substrates by laser molecular beam epitaxy. All the electron gases at the interfaces exhibit metallic behaviors with close sheet carrier density (1013–1014 cm−2), the electron gas at (1 0 0) interface presents the highest mobility, which is almost one order of magnitude higher than that at (1 1 1) interface below 70 K. At lower temperatures, all the electron gases show obvious photoelectrical response to visible light illumination. Light-assisted Hall measurements indicate distinctly different mechanisms for the photoconductivity of electron gases at the three interfaces. Our results can assist the understanding of the high mobility of electron gases at oxide interfaces, which will be helpful to optimize the electronic properties for device applications. [ABSTRACT FROM AUTHOR]

Electron gases are created at (1 0 0)-oriented SrTiO3 (STO) surfaces by being irradiated with high-speed Ar+ ions. Although fully metallic behavior is observed in both samples, the electron gases at STO surfaces bombarded with acceleration voltage of 200 V (sample L) show smaller carrier density and lower mobility than those at STO surfaces with 400 V acceleration voltage (sample H). Light related magnetoresistance (MR) and magnetic related photoelectrical properties for electron gases at STO surfaces are compared between sample L and sample H, respectively. Under light illumination, sample L shows increased positive MR, which decreases in sample H. Furthermore, the photoconductivity for sample L becomes slightly smaller and that for sample H rises obviously when the magnetic field is applied. The physical mechanisms responsible for the distinct behavior between the samples have been discussed. [ABSTRACT FROM AUTHOR]

The electron gas in LaAlO3/SrTiO3 heterostructures typically exhibits positive photoconductivity (PPC). Here, we report negative photoconductivity (NPC) induced by visible light in LaAlO3/SrTiO3 heterostructures grown in low oxygen pressure (~10−6 Torr). In contrast to the persistent PPC effect in LaAlO3/SrTiO3 heterostructures, the NPC effect is transient and wavelength independent. The origin of the NPC effect can be mainly attributed to enhanced electron scattering from oxygen-vacancy-related electron traps, confirmed by wavelength-dependent photoconductance and light-assisted Hall measurements. Our results provide a deeper insight into the complex interaction between light and oxygen vacancy in oxide electron gas. [ABSTRACT FROM AUTHOR]

Amorphous carbon (a-C) films, deposited on Si substrates at 500 °C, were transferred onto flexible polyethylene (PE) substrates by a lift-off method, which overcomes the limit of deposition temperature. After transferring, a-C films exhibited a large piezoresistive effect. Such flexible samples could detect the change of bending angle by attaching them onto Cu foils. The ratio of the bending and non-bending resistances reaches as large as ~27.8, which indicates a potential application as a pressure sensor. Also, the a-C/PE sample revealed an enhanced sensitivity to gas pressure compared with the a-C/Si one. By controlling the bending angle, the sensitivity range can be tuned to shift to a low- or high-pressure region. The fatigue test shows a less than 1% change in resistance after 10 000 bending cycles. Our work provides a route to prepare the flexible and piezoresistive carbon-based devices with high sensitivity, controllable pressure-sensing and high stability. [ABSTRACT FROM AUTHOR]

Three visible lines of M1 transitions from In-like tungsten were recorded using the Shanghai Permanent Magnet Electron Beam Ion Trap. The experimental wavelengths were measured as 493.84 ± 0.15, 226.97 ± 0.13 and 587.63 ± 0.23 nm (vacuum wavelengths). These results are in good agreement with theoretical predictions obtained using the large-scale relativistic many-body perturbation theory, in the form of the flexible atomic code. [ABSTRACT FROM AUTHOR]

La0.7Sr0.3MnO3 (LSMO) film exhibits certain unique properties which make it an ideal material for heterostructure-based multifunctional devices. In this paper, La0.7Sr0.3MnO3 thin films were grown epitaxially on SrTiO3, LaAlO3(LAO) and (LaAlO3)0.3-(SrAl0.5Ta0.5O3)0.7(LSAT) substrates, and their structural, electrical, magnetic and optical properties were examined and compared, aiming at revealing and explaining the effects of substrate on fundamental physical properties of LSMO films. Results show that (i) the effects of substrate materials on the electrical conductivity and paramagnetic–ferromagnetic transition temperature of the LSMO films could be ignored, and (ii) the LSMO film on LAO substrate has much higher coercive field and slower photoinduced relaxation process than other samples. This unusual behavior observed in the LSMO film on the LAO substrate could be related to the nature of the LAO substrate itself, on which the LSMO film showed different easy magnetization direction, and the film also exhibited relatively poor crystalline quality due to the twin domain structure of LAO crystal. Our results may help to understand the substrate-related electrical, magnetic and optical properties for perovskite manganite films. [ABSTRACT FROM AUTHOR]

We analyze the evolution and phase transition of Schwarzschild-de Sitter (SdS) spacetime by considering the connections between the black-hole horizon and the cosmological horizon. It is shown that the state equation is different from that of the van der Waals (vdW) system or charged anti-de Sitter black hole. However, when state parameters satisfy certain conditions, there is also a phase transition in SdS system. And the phase transition at the critical point is of second order. Moreover, the study on the evolution of SdS spacetime may help us understand the evolution of the Universe. [ABSTRACT FROM AUTHOR]

In our previous work, the agreement between the theoretical and measured wavelength for the 4f-M1 transition of Ag-like W shed light on the importance of a careful treatment of all core-valence correlation effects to obtain a reliable value of this fine structure energy separation. To confirm these results and extend the analysis isoelectronically, we have undertaken an experimental and theoretical study of the same M1 transition in Ag-like Yb. The measured wavelength for this M1 transition is 515.77 ± 0.10 nm (515.91 nm in vacuum) which agrees well with our ab initio theoretical value of 515.48 nm. [ABSTRACT FROM AUTHOR]

Epitaxial ferroelectric YMnO3 (YMO) thin films with high crystalline quality were fabricated on (0 0 0 1) GaN substrates by pulsed laser deposition followed by rapid thermal annealing. X-ray diffraction and transmission electron microscopy measurements reveal that YMO layers are of (0 0 0 1) orientation with an in-plane epitaxial relation (0 0 0 1)YMO||(0 0 0 1)GaN, [ {1\,1\,\bar{2}\,0} ]_{{\rm YMO}} \Vert[ {1\,1\,\bar{2}\,0}]_{{\rm GaN}} . The orientation of the lattice of YMO was found to be controlled by the annealing conditions. Y2O3 nanocrystallites observed near the interface were possible seeds to stabilize the orientation of the epitaxial YMO thin films. The appropriate annealing treatment could improve the crystalline quality and reduce the interface leakage current. [ABSTRACT FROM AUTHOR]

Recently, it has become common to produce transgenic cattle by somatic cell nuclear transfer. As a major step, donor cells are transfected with expression vectors that contain not only the target gene but also marker genes such as neomycin resistant gene (neoR) used for subsequent cell screening. However, such markers in transgenic animals may be undesirable for further researches (Kuroiwa et al.2004 Nature Genetics 36, 775–780). Therefore, the aim of this study was to excise the marker gene (neoR) in transgenic cattle by using transiently expressed CRE recombinase. Initially, the presence of loxP sites flanking neoR was confirmed in fibroblast cells derived from human lysozyme transgenic cloned cattle. By using cassettes from plasmids PBS185, pIRES-EGFP and pIREShyg3, IRES-EGFP element was inserted downstream of the CRE coding region, and the co-expression vector, which permits translation of GFP and CRE from one messenger RNA, was constructed. Then transgenic fibroblast cells were transfected by the CRE expression vector in circular format by Lipofectamine™2000 and screened by FACS after 48 h. GFP positive cells were selected to culture for 7 to 9 days, and removal of neoR was confirmed by PCR with 2000 to 3000 cells from each colony and the remaining cells used as donors for recloning. Then cleavage and blastocyst rate were evaluated; neoR excision was identified by single blastocyst PCR. Some blastocysts were harvested for differential staining and some used to conduct embryo transfer to evaluate in vitroand in vivodevelopmental ability. Data were analyzed using SAS (version 9.1) with one-way ANOVA. All experiments were replicated at least three times. We confirmed that loxP sites are correctly located at two sides of neoR. After transfection, neoR was removed from transgenic cloned fibroblast cells and cre was found to be expressed transiently. Additionally, neoR excision was confirmed by single blastocyst PCR. Furthermore, no significant difference was found on cleavage (P= 0.15) and blastocyst rate (P= 0.73) between cloned embryos when using neoR free donors and neoR included donors. The differential staining study showed similar numbers in terms of total cell number (P= 0.69) and the ratio of ICM to total cell number (P= 0.96). After embryo transfer, successful establishment of pregnancies were observed and pregnancy rate on Day 90 and Day 120 (Day 1 is the 1st day after embryo transfer) are similar with control (P> 0.05). In conclusion, we successfully excised resistant marker gene from transgenic cloned cattle by transient expression of CRE recombinase and we expect it will benefit bioreactor and animal transgenic research in the future. [ABSTRACT FROM AUTHOR]