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Raman spectral imaging is gaining more and more attention in biological studies because of its label-free characteristic. However, the discrimination of overlapping chemical contrasts has been a major challenge. In this study, we introduce an optical method to simultaneously obtain two orthogonally polarized Raman images from a single scan of the sample. We demonstrate how this technique can improve the quality and quantity of the hyperspectral Raman dataset and how the technique is expected to further extend the horizons of Raman spectral imaging in biological studies by providing more detailed chemical information. The dual-polarization Raman images of a HeLa cell.

Hydroxyapatite (HA) is synthesized at early stages of bone formation by osteoblasts. Nondestructive observation of early stages of osteoblastic mineralization provides crucial information for biological mechanism of bone formation. Raman microscopy serves as an ideal tool to observe the osteoblastic mineralization process because it shows the chemical information of the sample at a minimally invasive level. In addition, HA is a marker for osteoblastic mineralization, and HA Raman signal is strong enough to identify mineralized spots in osteoblasts. In this research, we visualized the distribution of HA in cultured mouse osteoblasts by Raman imaging and observed the location of the mineralized spots in the culture. We monitored HA Raman signal from osteoblast culture for 3 days after administrating the osteogenic differentiation medium and observed Raman signal associated with HA. We identified mineralized spots of KUSA-A1 by Raman imaging constructed from the distribution of HA Raman signal. We successfully visualized the distribution of the mineralized spots in the culture of KUSA-A1. We compared our Raman images with Alizarin red S staining assay, which was a conventional method to evaluate the mineralization process. Raman imaging of the KUSA-A1 culture visualized the mineralized spots more accurately than Alizarin red S staining assay. Raman imaging of HA serves as a powerful tool to identify the mineralized spots in an in vitro culture of osteogenic lineage cells. Copyright © 2014 John Wiley & Sons, Ltd.

The acquired immune system, mainly composed of T and B lymphocytes, plays a key role in protecting the host from infection. It is important and technically challenging to identify cell types and their activation status in living and intact immune cells, without staining or killing the cells. Using Raman spectroscopy, we succeeded in discriminating between living T cells and B cells, and visualized the activation status of living T cells without labeling. Although the Raman spectra of T cells and B cells were similar, they could be distinguished by discriminant analysis of the principal components. Raman spectra of activated T cells with anti-CD3 and anti-CD28 antibodies largely differed compared to that of naïve T cells, enabling the prediction of T cell activation status at a single cell level. Our analysis revealed that the spectra of individual T cells gradually change from the pattern of naïve T cells to that of activated T cells during the first 24 h of activation, indicating that changes in Raman spectra reflect slow changes rather than rapid changes in cell state during activation. Our results indicate that the Raman spectrum enables the detection of dynamic changes in individual cell state scattered in a heterogeneous population.

Raman microscopy is a powerful tool for analytical imaging. The wavelength shift of Raman scattering corresponds to molecular vibrational energy. Therefore, we can access rich chemical information, such as distribution, concentration, and chemical environment of sample molecules. Despite these strengths of Raman microscopy, the spatial resolution has been a limiting factor for many practical applications. In this study, we developed a large-area, high-resolution Raman microscope by utilizing structured illumination microscopy (SIM) to overcome the spatial resolution limit. A structured line-illumination (SLI) Raman microscope was constructed. The structured illumination is introduced along the line direction by the interference of two line-shaped beams. In SIM, the spatial frequency mixing between structured illumination and Raman scattering from the sample allows access to the high spatial frequency information beyond the conventional cut-off. As a result, the FWHM of 40-nm fluorescence particle images showed a clear resolution enhancement in the line direction: 366 nm in LI and 199 nm in SLI microscope. Using the developed microscope, we successfully demonstrated high-resolution Raman imaging of various kinds of specimens, such as few-layer graphene, graphite, mouse brain tissue, and polymer nanoparticles. The high resolution Raman images showed the capability to extract original spectral features from the mixed Raman spectra of a multi-component sample because of the enhanced spatial resolution, which is advantageous in observing complex spectral features. The Raman microscopy technique reported here enables us to see the detailed chemical structures of chemical, biological, and medical samples with a spatial resolution smaller than 200 nm.

Indium oxide (In2O3) nanorods, nanotowers and tin-doped (Sn:In = 1:100) indium oxide (ITO) nanorods have been fabricated by thermal evaporation. The morphology, microstructure and chemical composition of these three nanoproducts are characterized by FE-SEM, HRTEM and XPS. To further investigate the optoelectronic properties, the I–V curves and cathodoluminescence (CL) spectra are measured. The electrical resistivity of In2O3 nanorods, nanotowers and ITO nanorods are 1.32 kΩ, 0.65 kΩ and 0.063 kΩ, respectively. CL spectra of these three nanoproducts clearly indicate that tin-doped (Sn:In = 1:100) indium oxide (ITO) nanorods cause a blue shift. No doubt ITO nanorods obtain the highest performance among these three nanoproducts, and this also means that Sn-doped In2O3 nanostructures would be the best way to enhance the optoelectronic properties. Additionally, the growing mechanism and the optoelectronic properties of these three nanostructures are discussed. This study is beneficial to the applications of In2O3 nanorods, nanotowers and ITO nanorods in optoelectronic nanodevices.

Gene targeting using short interfering RNA (siRNA) has become a common strategy to explore gene function because of its prominent efficacy and specificity. The human transmembrane 4 superfamily member 4 (TM4SF4) was originally identified in intestine and liver as a cell proliferation-related gene. Recently, it showed an increased expression in the hepatocellular carcinoma (HCC) tissues. In this study, we developed an adenoviral vector harboring an effective siRNA targeting TM4SF4 (AdSiTM4SF4) and identified its function in suppression of tumor cell growth. It was confirmed that TM4SF4 was overexpressed in HCC tissues compared with its paired non-tumor tissues by western blot analysis and immunohistochemistry. Remarkably, it was more abundant on the cell surface of HCC cells. The signals of ectopically expressed TM4SF4 in four cell lines dramatically localized in the plasma membrane, slightly in the cytoplasm, and absent in the nucleus, demonstrating that TM4SF4 is a membrane protein. Targeting TM4SF4 by AdSiTM4SF4 successfully exerted a gene knockdown effect. The QGY-7701 and SMMC-7721 HCC cells infected with AdSiTM4SF4 displayed remarkably attenuated growth potential. Moreover, intratumoral injection of AdSiTM4SF4 significantly suppressed tumor growth in a xenograft mouse model using SMMC-7721 hepatoma cells. Our results indicated that targeting TM4SF4 might be a promising modality for inhibition of HCC.

The 1602 cm–1 Raman signature, which we call the “Raman spectroscopic signature of life” in yeasts, is a marker Raman band for cell metabolic activity. Despite the established fact that its intensity sensitively reflects the metabolic status of the cell, its molecular origin remained unclear. In this work, we propose ergosterol as the major contributor of the 1602 cm–1 Raman signature. The theoretical isotope shift calculation for ergosterol agreed with previous observations. Furthermore, experiments showed that the Raman spectrum of ergosterol corresponds very well with the depleting spectral component in yeast that behaves together with the 1602 cm–1 signature when the cells are under stress. This work implies that the 1602 cm–1 Raman signature could serve as an intrinsic ergosterol marker in yeasts for the study of sterol metabolism in vivo and in a label-free manner, which could not be done by any other techniques at the current stage. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The human transmembrane 4 superfamily member 4 or intestinal and liver tetraspan membrane protein (TM4SF4/il-TMP) was originally cloned as an intestinal and liver tetraspan membrane protein and mediates density-dependent cell proliferation. The rat homolog of TM4SF4 was found to be up-regulated in regenerating liver after two-thirds hepatectomy and overexpression of TM4SF4 could enhance liver injury induced by CCl4. However, the expression and significance of TM4SF4/il-TMP in liver cancer remain unknown. Here, we report that TM4SF4/il-TMP is frequently and significantly overexpressed in hepatocellular carcinoma (HCC). Real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis showed that TM4SF4/il-TMP mRNA and protein levels were up-regulated in approximate to 80 of HCC tissues. Immunohistochemical analysis of a 75 paired HCC tissue microarray revealed that TM4SF4/il-TMP was significantly overexpressed in HCC tissues (P 0.001), and high immunointensity of TM4SF4/il-TMP tended to be in well-to-moderately differentiated HCC compared with poorly differentiated tumors. Functional studies showed that overexpression of TM4SF4/il-TMP in QGY-7701 and BEL-7404 HCC cell lines through stable transfection of TM4SF4 expression plasmid significantly promoted both cell growth and colony formation of HCC cells. Reduction of TM4SF4/il-TMP expression in QGY-7701 and BEL-7404 cells by stably transfecting TM4SF4 antisense plasmid caused great inhibition of cell proliferation. Our findings suggest that TM4SF4/il-TMP has the potential to be biomarker in HCC and plays a crucial role in promotion of cancer cell proliferation.

Shortly after its development, the white light supercontinuum laser was applied to confocal scanning microscopy as a more versatile substitute for the multiple monochromatic lasers normally used for the excitation of fluorescence. This light source is now available coupled to commercial confocal fluorescence microscopes. We have evaluated a supercontinuum laser as a source for a different purpose: confocal interferometric imaging of living cells and artificial models by interference reflection. We used light in the range 460–700 nm where this source provides a reasonably flat spectrum, and obtained images free from fringe artefacts caused by the longer coherence length of conventional lasers. We have also obtained images of cytoskeletal detail that is difficult to see with a monochromatic laser.

In the last couple of decades, the spatial resolution in optical microscopy has increased to unprecedented levels by exploiting the fluorescence properties of the probe. At about the same time, Raman imaging techniques have emerged as a way to image inherent chemical information in a sample without using fluorescent probes. However, in many applications, the achievable resolution is limited to about half the wavelength of excitation light. Here we report the use of structured illumination to increase the spatial resolution of label-free spontaneous Raman microscopy, generating highly detailed spatial contrast from the ensemble of molecular information in the sample. Using structured line illumination in slit-scanning Raman microscopy, we demonstrate a marked improvement in spatial resolution and show the applicability to a range of samples, including both biological and inorganic chemical component mapping. This technique is expected to contribute towards greater understanding of chemical component distributions in organic and inorganic materials., Raman imaging provides visualization of molecular content in a sample, but has been practically limited in resolution. Here, the authors implement structured line illumination in slit-scanning Raman microscopy, expanding its resolvable spatial frequencies without spoiling the advantage of the Raman approach.

In this paper, the Lateral Positive-Intrinsic-Negative (LPIN) diode and its application in the high efficiency silicon-based plasma antenna are introduced. A LPIN diode can be employed as a plasma island when sufficient DC power is supplied, which can be used for reconfigurable antennas. The conductivity of intrinsic layer is simulated using the finite element method (FEM). The frequency reconfigurable dipole antenna is design based on LPIN diode array, which comprises 24 LPIN diodes. These research results of this paper can provide theoretical basis for further development of high efficiency frequency reconfigurable silicon-based plasma antenna.

HEM1 gene encodes δ-aminolevulinate synthase that is required for haem synthesis. It is an essential gene for yeast survival. The Raman spectra of HEM1 knockout (hem1Δ) yeast cells lacks a Raman band at 1602 cm(-1) that has been shown to reflect cell metabolic activity. This result suggests that the molecule giving rise to the"Raman spectroscopic signature of life" is closely related to haem functions in the cell. High amount of squalene is also observed in the hem1Δ strain, which is another new discovery of this study.

We synthesize colloidal CdSe/CdS core/shell quantum dots with different shell thicknesses, and there are five samples including CdSe core dots, and CdSe/CdS core/shell dots with 1–4 CdS layers. X-ray diffraction and Raman measurements indicate that the stress in CdSe core becomes stronger with the increasing shell thickness, and the optical measurements show that when the shell becomes thicker, the photoluminescence quantum yield is enhanced, and the radiative decay is also expedited. The temperature-dependent optical spectra are measured. The relation between the microstructure and the optical properties is discussed.

Osteoblastic mineralization occurs during the early stages of bone formation. During this mineralization, hydroxyapatite (HA), a major component of bone, is synthesized, generating hard tissue. Many of the mechanisms driving biomineralization remain unclear because the traditional biochemical assays used to investigate them are destructive techniques incompatible with viable cells. To determine the temporal changes in mineralization-related biomolecules at mineralization spots, we performed time-lapse Raman imaging of mouse osteoblasts at a subcellular resolution throughout the mineralization process. Raman imaging enabled us to analyze the dynamics of the related biomolecules at mineralization spots throughout the entire process of mineralization. Here, we stimulated KUSA-A1 cells to differentiate into osteoblasts and conducted time-lapse Raman imaging on them every 4 hours for 24 hours, beginning 5 days after the stimulation. The HA and cytochrome c Raman bands were used as markers for osteoblastic mineralization and apoptosis. From the Raman images successfully acquired throughout the mineralization process, we found that β-carotene acts as a biomarker that indicates the initiation of osteoblastic mineralization. A fluctuation of cytochrome c concentration, which indicates cell apoptosis, was also observed during mineralization. We expect time-lapse Raman imaging to help us to further elucidate osteoblastic mineralization mechanisms that have previously been unobservable.

Using Raman spectral imaging, we visualized the cell state transition during differentiation and constructed hypothetical potential landscapes for attractors of cellular states on a state space composed of parameters related to the shape of the Raman spectra. As models of differentiation, we used the myogenic C2C12 cell line and mouse embryonic stem cells. Raman spectral imaging can validate the amounts and locations of multiple cellular components that describe the cell state such as proteins, nucleic acids and lipids; thus, it can report the state of a single cell. Herein, we visualized the cell state transition during differentiation using Raman spectral imaging of cell nuclei in combination with principal component analysis. During differentiation, cell populations with a seemingly homogeneous cell state before differentiation showed heterogeneity at the early stage of differentiation. At later differentiation stages, the cells returned to a homogeneous cell state that was different from the undifferentiated state. Thus, Raman spectral imaging enables us to illustrate the disappearance and reappearance of an attractor in a differentiation landscape, where cells stochastically fluctuate between states at the early stage of differentiation.

CIDE-B [cell death-inducing DFF45 (DNA fragmentation factor 45)-like effector B] is a member of the CIDE family of apoptosis-inducing factors. The highly restricted pattern of expression of CIDE-B in the liver and spleen suggests that a mechanism exists for the tissue- and cell-specific regulation of transcription of this gene. We have analysed the promoters of the human CIDE-B gene, particularly the mechanism of cell-specific transcription. Expression of CIDE-B is driven by two promoters which are responsible for the synthesis of two types of transcript, and Sp1 and Sp3 are key regulators of basal transcription from both the upstream and the internal promoter, as indicated by EMSAs (electrophoretic mobility-shift assays) and site-directed mutagenesis. Bisulphite sequencing analysis demonstrated that the upstream promoter was hypermethylated in cells that did not express the long transcript of CIDE-B, but was hypomethylated in cells that expressed this transcript. Furthermore, methylation of this region in vitro reduced the promoter activity to approximately 5% of the control. Thus methylation at CpG sites in the upstream promoter region appeared to be important for cell-specific synthesis of the long transcript. By contrast, HNF4alpha (hepatocyte nuclear factor-4alpha) bound to the internal promoter and enhanced its activity. Moreover, the short transcript of CIDE-B gene was expressed in cells which do not normally express this transcript upon introduction of exogenous HNF4alpha, demonstrating the involvement of HNF4alpha in the cell-specific synthesis of the short transcript. Thus our analysis revealed a novel mechanism for the cell-specific transcription of the human CIDE-B gene, which involves epigenetic and genetic control at separate respective promoters.

Mineralization is main function of osteoblasts. In the mineralization process, osteoblasts initiate production of hydroxyapatite (HA: Ca10(PO4)6(OH)2), which is major component of bone. Then, through several biological processes they calcify surrounding extracellular matrix and finally bone tissue is formed. Previous researches have shown that various biomolecules are involved in the process of osteoblastic mineralization. Although traditional bio logical assays greatly contribute to understanding bone formation, they are unable to follow up the osteoblastic mineralization process since they are destructive techniques. Therefore a nondestructive and quantitative measurement technique is required to further increase our understanding of the osteoblastic mineralization process. Raman imaging is a non-destructive and label-free technique that provides contrast images based on vibrational frequencies that are derived to target molecules. Thus, Raman imaging enables time-lapse observation of the dynamics of the biomolecules in a living specimen without any preliminary preparations. In this study, we observed the osteoblastic mineralization process in the culture of mouse osteoblasts by consecutive Raman imaging

System level understanding of the cell requires detailed description of the cell state, which is often characterized by the expression levels of proteins. However, understanding the cell state requires comprehensive information of the cell, which is usually obtained from a large number of cells and their disruption. In this study, we used Raman spectroscopy, which can report changes in the cell state without introducing any label, as a non-invasive method with single cell capability. Significant differences in Raman spectra were observed at the levels of both the cytosol and nucleus in different cell-lines from mouse, indicating that Raman spectra reflect differences in the cell state. Difference in cell state was observed before and after the induction of differentiation in neuroblastoma and adipocytes, showing that Raman spectra can detect subtle changes in the cell state. Cell state transitions during embryonic stem cell (ESC) differentiation were visualized when Raman spectroscopy was coupled with principal component analysis (PCA), which showed gradual transition in the cell states during differentiation. Detailed analysis showed that the diversity between cells are large in undifferentiated ESC and in mesenchymal stem cells compared with terminally differentiated cells, implying that the cell state in stem cells stochastically fluctuates during the self-renewal process. The present study strongly indicates that Raman spectral morphology, in combination with PCA, can be used to establish cells' fingerprints, which can be useful for distinguishing and identifying different cellular states.

Raman spectral imaging has become a more and more popular technique in biological studies because it can extract chemical information from living cells in a label-free manner. One of the most challenging issues in the label-free Raman imaging of biological samples is to increase the molecular specificity in the spectra for better chemical contrast. Usually, the Raman spectrum from a cell is dominated by a few strong Raman bands such as the amide I band around 1650 cm -1 , CH 2 bend around 1445 cm -1 or the amide III band around 1300 cm -1 and it is not easy to get chemical contrast from other Raman bands that overlap with them. In this study, we aim to manipulate the chemical contrast in a living cell by exploiting the polarisation effects in Raman spectroscopy. By simply putting an analyser before the spectrometer, we can take the Raman image at the parallel and perpendicular polarisation against the incident light at the sample. The Raman spectra at the two orthogonal polarisations represent the Raman signals with different molecular orientation and symmetry of vibrations. Our experimental results demonstrate that at certain Raman shifts the two orthogonal polarisations indeed present different chemical contrasts. This indicates that polarized Raman imaging can help us visualise the different chemical contrasts that overlap at the same Raman shift and therefore increase the amount of chemical information we can get from cells.

Gene targeting using short interfering RNA (siRNA) has become a common strategy to explore gene function because of its prominent efficacy and specificity. The human transmembrane 4 superfamily member 4 (TM4SF4) was originally identified in intestine and liver as a cell proliferation-related gene. Recently, it showed an increased expression in the hepatocellular carcinoma (HCC) tissues. In this study, we developed an adenoviral vector harboring an effective siRNA targeting TM4SF4 (AdSiTM4SF4) and identified its function in suppression of tumor cell growth. It was confirmed that TM4SF4 was overexpressed in HCC tissues compared with its paired non-tumor tissues by western blot analysis and immunohistochemistry. Remarkably, it was more abundant on the cell surface of HCC cells. The signals of ectopically expressed TM4SF4 in four cell lines dramatically localized in the plasma membrane, slightly in the cytoplasm, and absent in the nucleus, demonstrating that TM4SF4 is a membrane protein. Targeting TM4SF4 by AdSiTM4SF4 successfully exerted a gene knockdown effect. The QGY-7701 and SMMC-7721 HCC cells infected with AdSiTM4SF4 displayed remarkably attenuated growth potential. Moreover, intratumoral injection of AdSiTM4SF4 significantly suppressed tumor growth in a xenograft mouse model using SMMC-7721 hepatoma cells. Our results indicated that targeting TM4SF4 might be a promising modality for inhibition of HCC.

The hepatitis B virus X protein (HBx) has been implicated in the development of hepatocellular carcinoma (HCC) associated with chronic infection. As a multifunctional protein, HBx regulates numerous cellular pathways, including autophagy. Although autophagy has been shown to participate in viral DNA replication and envelopment, it remains unclear whether HBx-activated autophagy affects host cell death, which is relevant to both viral pathogenicity and the development of HCC. Here, we showed that enforced expression of HBx can inhibit starvation-induced cell death in hepatic (L02 and Chang) or hepatoma (HepG2 and BEL-7404) cell lines. Starvation-induced cell death was greatly increased in HBX-expressing cell lines treated either with the autophagy inhibitor 3-methyladenine (3-MA) or with an siRNA directed against an autophagy gene, beclin 1. In contrast, treatment of cells with the apoptosis inhibitor Z-Vad-fmk significantly reduced cell death. Our results demonstrate that HBx-mediated cell survival during starvation is dependent on autophagy. We then further investigated the mechanisms of cell death inhibition by HBx. We found that HBx inhibited the activation of caspase-3, an execution caspase, blocked the release of mitochondrial apoptogenic factors, such as cytochrome c and apoptosis-inducing factor (AIF), and inhibited the activation of caspase-9 during starvation. These results demonstrate that HBx reduces cell death through inhibition of mitochondrial apoptotic pathways. Moreover, increased cell viability was also observed in HepG2.2.15 cells that replicate HBV and in cells transfected with HBV genomic DNA. Our findings demonstrate that HBx promotes cell survival during nutrient deprivation through inhibition of apoptosis and activation of autophagy. This highlights an important potential role of autophagy in HBV-infected hepatocytes growing under nutrient-deficient conditions.

The human lissencephaly-1 gene (LIS1) is a disease gene responsible for Miller-Dieker lissencephaly syndrome (MDL). LIS1 gene is located in the region of chromosome 17p13.3 that is frequency deleted in MDL patients and in human liver cancer cells. However, the expression and significance of LIS1 in liver cancer remain unknown. Here, we investigated the expression of LIS1 in hepatocellular carcinoma (HCC) tissues by real-time PCR, Western blot, and immunohistochemistry. The results indicated that the mRNA and protein levels of LIS1 were downregulated in about 70% of HCC tissues, and this downregulation was significantly associated with tumor progression. Functional studies showed that the reduction of LIS1 expression in the normal human liver cell line QSG7701 or the mouse fibroblast cell line NIH3T3 by shRNA resulted in colony formation in soft agar and xenograft tumor formation in nude mice, demonstrating that a decrease in the LIS1 level can promote the oncogenic transformation of cells. We also observed that the phenotypes of LIS1-knockdown cells displayed various defective mitotic structures, suggesting that the mechanism by which reduced LIS1 levels results in tumorigenesis is associated with its role in mitosis. Furthermore, we demonstrated that ectopic expression of LIS1 could significantly inhibit HCC cell proliferation and colony formation. Our results suggest that LIS1 plays a potential tumor suppressor role in the development and progression of HCC.

AIS (Automatic Identification System) has more and more been used on a ship to identify a target and improve the navigation safety at sea as a new type of radio navaid system. AIS network has also been constructed at the main harbor in many countries to enhance the traffic safety and the maritime management. In the paper, AIS system is briefly described. It stresses on Chinese AIS network frame. The applications and traffic management are discussed. It is analyzed that AIS network brings to the benefits and the influences on the traffic safety and the maritime management in China. Expectation of application prospect of the network is conducted.

LPTS/PinX1, a telomerase inhibitor composed of 328 amino acids, binds to the telomere associated protein Pin2/TRF1 and to the telomerase catalytic subunit hTERT. However, the mechanism by which LPTS/PinX1 regulates telomerase activity remains unclear. Here we show, for the first time, that LPTS/PinX1 uses different domains to interact with Pin2/TRF1 and hTERT. The LPTS/PinX1(254-289) fragment specifically binds to Pin2/TRF1, and LPTS/PinX1(290-328) can associate with hTERT. Compared with the full-length LPTS/PinX1 protein, LPTS/PinX1(290-328) shows stronger in vitro telomerase inhibitory activity. Moreover, the LPTS/PinX1 protein was recruited to telomeres for binding to Pin2/TRF1. Overexpression of LPTS/PinX1(290-328), which contains a nucleolus localization signal, in cells resulted in telomere shortening and progressive cell death. Conversely, telomere elongation was induced by expression of the dominant-negative LPTS/PinX1(1-289). Our results suggest that the C-terminal fragment of LPTS/PinX1 (LPTS/PinX1(290-328)) contains a telomerase inhibitory domain that is required for the inhibition of telomere elongation and the induction of cell crisis. Our studies also provide evidence that LPTS/PinX1 interaction with Pin2/TRF1 may play a role in the stabilization of telomeres.

The traditional spatial distributions of GDP(Gross domestic product) are calculated on the basis of administrative boundaries. This paper establishes a simulated spatial GDP model and update model instead of the traditional statistical distributions of social and economic output value which based on administrative boundaries. We use the grid analysis technology and statistical analysis technology, studies the pertinence between the land-use situation and the spatial distribution of GDP through researching the relationships among all kinds of geographical variable, then establishes the spatial distributed model of GDP. Based on the analysis of the key part of grid GDP update, the paper puts forward a grid GDP update model based on administrative polygon borders according to the simple scale model and the environmental terms' area scale model. It resolves those problems exiting in the old method which made the spatial orientation inaccurate, inexactitude, not unification, and a series of spatial data incompact integration.

Human beclin 1 is the first identified mammalian gene to induce autophagy. It is commonly expressed at reduced levels in breast tumors; however, it is overexpressed in hepatitis B virus (HBV)-infected cancerous liver tissues. To expose the possible mechanism and biological significance of this up-regulation of beclin 1, we investigated the regulation of beclin 1 expression by HBV x protein (HBx) in hepatic or hepatoma cell lines. Here, we showed that enforced expression of HBx by transfection technology results in the up-regulation of the endogenous messenger RNA (mRNA) and protein levels of Beclin 1 in the tested cells. Using a luciferase- reporter assay, we demonstrated that HBx transactivates beclin 1 promoter activity in a dose-dependent manner. The promoter region of the beclin 1 gene identified in this study is located at nt −277/+197 and has the maximum transcriptional activity. HBx-mediated up-regulation of beclin 1 expression might be direct, that is, via its promoter. Furthermore, the cells that transiently or stably expressed HBx showed an enhanced accumulation of vacuoles carrying the autophagy marker LC3 as compared with the control cells, which was induced by nutrient starvation, indicating HBx-enhanced autophagy. Moreover, this enhanced autophagy occurred in HepG2.2.15 cells that replicate HBV and in cells transfected with HBV genomic DNA, suggesting that HBV infection also causes increased levels of autophagy under starvation conditions. Treatment of cells with beclin 1 small interfering RNA (siRNA) blocked HBx–enhanced autophagy, demonstrating that the function of HBx in influencing autophagy is Beclin 1 dependent. Conclusion: Our findings suggest a novel function of HBx in increasing autophagy through the up-regulation of beclin1 expression, and this may provide an important mechanism in HBV-infected hepatocytes growing under nutrient-deficient conditions. (HEPATOLOGY 2009;49:60-71)

To study the effect of Streptococcus sanguis on corrosion resistance of magnetic retainers in which are encapsulated with stainless steel artificial saliva.A magnetic retainer was put in one culture flask,which was filled with artificial saliva.Ten of them were added Streptococcus sanguis suspension,the others were added PBS as control.The culture flasks were cultivated in incubator(36 degrees centigrade). 5 ml suspension was dislodged from each flask at the 3rd, 10th and 20th day. The quantity of Fe(3+) and Mn(2+) was detected.Statistical analysis of paired t test was performed with SPSS10.0 software package.When Streptococcus sanguis existed, the quantity of Fe(3+) and Mn(2+) was significantly higher than that in the control (P0.01).The existence of Streptococcus sanguis destroys the corrosion resistance of magnetic retainers remarkably.