274 research outputs found

    Determination of speciation of elements related to blood sugar in bioactive extracts from Cyclocarya paliurus leaves by FIA-ICP-MS

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    This paper describes the development and application of FIA-ICP-MS technique for the speciation of trace elements in extracts of Cyclocarya Paliurus (Batal.) Iljinsk (CP) leaves, an herbal tea used widely in China as dietary supplement for Elements Related to Blood Sugar (ERBS), which are reported to have the beneficial effects of lowering blood sugar. Most ERBSs are found to be water-soluble. On the basis of elemental distribution, the aqueous solutions of CP of different origins can be separated into two groups: one is rich in organo-magnesium, organo-manganese, organo-zinc, inorganic copper, and inorganic nickel; while the other is rich in inorganic magnesium, inorganic manganese, inorganic copper, inorganic nickel and organo-zinc. The ERBSs in two bioactive extracts of CP named EE and POLY were analyzed and compared, and the results suggest that the extracts are good dietary supplement for people, especially Diabetes Mellitus (DM) patients through the provision of ERBSs of Mn, Zn, Mg, Cu, and Ni in organic or inorganic forms

    Directed self-organization of graphene nanoribbons on SiC

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    Realization of post-CMOS graphene electronics requires production of semiconducting graphene, which has been a labor-intensive process. We present tailoring of silicon carbide crystals via conventional photolithography and microelectronics processing to enable templated graphene growth on 4H-SiC{1-10n} (n = 8) crystal facets rather than the customary {0001} planes. This allows self-organized growth of graphene nanoribbons with dimensions defined by those of the facet. Preferential growth is confirmed by Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM) measurements, and electrical characterization of prototypic graphene devices is presented. Fabrication of > 10,000 top-gated graphene transistors on a 0.24 cm2 SiC chip demonstrates scalability of this process and represents the highest density of graphene devices reported to date.Comment: 13 pages, 5 figure

    Visualized exploratory spatiotemporal analysis of hand-foot-mouth disease in southern China

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    Objectives: In epidemiological research, major studies have focused on theoretical models; however, few methods of visual analysis have been used to display the patterns of disease distribution.Design: For this study, a method combining the space-time cube (STC) with space-time scan statistics (STSS) was used to analyze the pattern of incidence of hand-foot-mouth disease (HFMD) in Guangdong Province from May 2008 to March 2009. In this research, STC was used to display the spatiotemporal pattern of incidence of HFMD, and STSS were used to detect the local aggregations of the disease.Setting: The hand-foot-mouth disease data were obtained from Guangdong Province from May 2008 to March 2009, with a total of 68,130 cases.Results: The STC analysis revealed a differential pattern of HFMD incidence among different months and cities and also showed that the population density and average precipitation are correlated with the incidence of HFMD. The STSS analysis revealed that the most likely aggregation includes the Shenzhen, Foshan and Dongguan populations, which are the most developed regions in Guangdong Province.Conclusion: Both STC and STSS are efficient tools for the exploratory data analysis of disease transmission. STC clearly displays the spatiotemporal patterns of disease. Using the maximum likelihood ratio, the STSS model precisely locates the most likely aggregation

    Dynamic Regulation of Oct1 during Mitosis by Phosphorylation and Ubiquitination

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    Transcription factor Oct1 regulates multiple cellular processes. It is known to be phosphorylated during the cell cycle and by stress, however the upstream kinases and downstream consequences are not well understood. One of these modified forms, phosphorylated at S335, lacks the ability to bind DNA. Other modification states besides phosphorylation have not been described.We show that Oct1 is phosphorylated at S335 in the Oct1 DNA binding domain during M-phase by the NIMA-related kinase Nek6. Phospho-Oct1 is also ubiquitinated. Phosphorylation excludes Oct1 from mitotic chromatin. Instead, Oct1(pS335) concentrates at centrosomes, mitotic spindle poles, kinetochores and the midbody. Oct1 siRNA knockdown diminishes the signal at these locations. Both Oct1 ablation and overexpression result in abnormal mitoses. S335 is important for the overexpression phenotype, implicating this residue in mitotic regulation. Oct1 depletion causes defects in spindle morphogenesis in Xenopus egg extracts, establishing a mitosis-specific function of Oct1. Oct1 colocalizes with lamin B1 at the spindle poles and midbody. At the midbody, both proteins are mutually required to correctly localize the other. We show that phospho-Oct1 is modified late in mitosis by non-canonical K11-linked polyubiquitin chains. Ubiquitination requires the anaphase-promoting complex, and we further show that the anaphase-promoting complex large subunit APC1 and Oct1(pS335) interact.These findings reveal mechanistic coupling between Oct1 phosphorylation and ubquitination during mitotic progression, and a role for Oct1 in mitosis

    Gold Nanoparticle-Based Surface-Enhanced Raman Scattering for Noninvasive Molecular Probing of Embryonic Stem Cell Differentiation

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    This study reports the use of gold nanoparticle-based surface-enhanced Raman scattering (SERS) for probing the differentiation of mouse embryonic stem (mES) cells, including undifferentiated single cells, embryoid bodies (EBs), and terminally differentiated cardiomyocytes. Gold nanoparticles (GNPs) were successfully delivered into all 3 mES cell differentiation stages without affecting cell viability or proliferation. Transmission electron microscopy (TEM) confirmed the localization of GNPs inside the following cell organelles: mitochondria, secondary lysosome, and endoplasmic reticulum. Using bright- and dark-field imaging, the bright scattering of GNPs and nanoaggregates in all 3 ES cell differentiation stages could be visualized. EB (an early differentiation stage) and terminally differentiated cardiomyocytes both showed SERS peaks specific to metabolic activity in the mitochondria and to protein translation (amide I, amide II, and amide III peaks). These peaks have been rarely identified in undifferentiated single ES cells. Spatiotemporal changes observed in the SERS spectra from terminally differentiated cardiomyocyte tissues revealed local and dynamic molecular interactions as well as transformations during ES cell differentiation

    Overview of the DESI Milky Way Survey

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    We describe the Milky Way Survey (MWS) that will be undertaken with the Dark Energy Spectroscopic Instrument (DESI) on the Mayall 4 m telescope at the Kitt Peak National Observatory. Over the next 5 yr DESI MWS will observe approximately seven million stars at Galactic latitudes ∣b∣ > 20°, with an inclusive target selection scheme focused on the thick disk and stellar halo. MWS will also include several high-completeness samples of rare stellar types, including white dwarfs, low-mass stars within 100 pc of the Sun, and horizontal branch stars. We summarize the potential of DESI to advance understanding of the Galactic structure and stellar evolution. We introduce the final definitions of the main MWS target classes and estimate the number of stars in each class that will be observed. We describe our pipelines for deriving radial velocities, atmospheric parameters, and chemical abundances. We use ≃500,000 spectra of unique stellar targets from the DESI Survey Validation program (SV) to demonstrate that our pipelines can measure radial velocities to ≃1 km s−1 and [Fe/H] accurate to ≃0.2 dex for typical stars in our main sample. We find the stellar parameter distributions from ≈100 deg2 of SV observations with ≳90% completeness on our main sample are in good agreement with expectations from mock catalogs and previous surveys

    The Arabidopsis thaliana F-box gene HAWAIIAN SKIRT is a new player in the microRNA pathway

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    In Arabidopsis, the F-box HAWAIIAN SKIRT (HWS) protein is important for organ growth. Loss of function of HWS exhibits pleiotropic phenotypes including sepal fusion. To dissect the HWS role, we EMS-mutagenized hws-1 seeds and screened for mutations that suppress hws-1 associated phenotypes. We identified shs-2 and shs-3 (suppressor of hws-2 and 3) mutants in which the sepal fusion phenotype of hws-1 was suppressed. shs-2 and shs-3 (renamed hst-23/hws-1 and hst-24/hws-1) carry transition mutations that result in premature terminations in the plant homolog of Exportin-5 HASTY (HST), known to be important in miRNA biogenesis, function and transport. Genetic crosses between hws-1 and mutant lines for genes in the miRNA pathway, also suppress the phenotypes associated with HWS loss of function, corroborating epistatic relations between the miRNA pathway genes and HWS. In agreement with these data, accumulation of miRNA is modified in HWS loss or gain of function mutants. Our data propose HWS as a new player in the miRNA pathway, important for plant growth

    Targeting tumor-associated macrophages by anti-tumor Chinese materia medica

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    Tumor-associated macrophages (TAMs) play a key role in all stages of tumorigenesis and tumor progression. TAMs secrete different kinds of cytokines, chemokines, and enzymes to affect the progression, metastasis, and resistance to therapy depending on their state of reprogramming. Therapeutic benefit in targeting TAMs suggests that macrophages are attractive targets for cancer treatment. Chinese materia medica (CMM) is an important approach for treating cancer in China and in the Asian region. According to the theory of Chinese medicine (CM) and its practice, some prescriptions of CM regulate the body's internal environment possibly including the remodeling the tumor microenvironment (TME). Here we briefly summarize the pivotal effects of TAMs in shaping the TME and promoting tumorigenesis, invasion, metastasis and immunosuppression. Furthermore, we illustrate the effects and mechanisms of CMM targeting TAMs in antitumor therapy. Finally, we reveal the CMM's dual-regulatory and multi-targeting functions on regulating TAMs, and hopefully, provide the theoretical basis for CMM clinical practice related to cancer therapy

    Improved Measurement of Electron Antineutrino Disappearance at Daya Bay

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