Abstract:The Traditional Chinese Medicine herbs Pollen Typhae and Pollen Typhae Carbonisatus have been used as a hemostatic medicine promoting blood clotting for thousands of years. In this study, a reliable, highly sensitive method based on LC-MS/MS has been developed for differentiation of the heating products of total flavonoids in Pollen Typhae (FPT-N). Twenty three peaks were detected and 18 peaks have been structurally identified by comparing retention times, high resolution mass spectrometry data, and fragment ions with those of the reference substances and/or literature data. Additionally, 15 compounds have been quantified by multiple reaction monitoring in the negative ionization mode. It was found that the contents of the characterized compounds differed greatly from each other in FPT-N samples. Among them, the content of huaicarbon B OPEN ACCESSMolecules 2015, 20 18353 significantly increased at first, while it decreased after heating for 25 min, which could be considered as the characteristic component for distinguishing FPT-N. The present study provided an approach to rapidly distinguish the differences of FPT-N samples. In addition, the actively summarized characteristic fragmentation might help deducing the structure of unknown flavonols compounds. Furthermore, transformation rules of flavonoids during the heating process in carbonisatus development could contribute to hemostatic therapeutic component exploration.

Cancer stem cells (CSCs) are crucial components of the tumor microenvironment that take part in tumor initiation, progression, recurrence, metastasis, and resistance to chemotherapy. This study explores the mechanisms through which CSCs maintain their stemness, especially in tumors of colorectal cancer (CRC), which thus far remain uncertain. Our findings indicated that the expression of miR-20b-5p is negatively correlated with that of metastasis-associated lung adenocarcinoma transcript-1 (MALAT1, r = −0.928, p = 0.023) and Oct4 (r = −0.894, p = 0.041) in CRC cells. We hypothesized that there may be some targeted regulatory relationships among MALAT1, miR-20b-5p, and Oct4. We proceeded to show that both si-MALAT1 and miR-20b-5p-mimic attenuated microsphere formation and self-renewal capacity, decreased the proportion of CSCs, and downregulated the expression of proteins associated with tumor cell stemness maintenance (Oct4, Nanog, sex-determining region Y-box 2, and Notch1) and cellular metabolism (glucose transporter 1, lactate dehydrogenase B, hexokinase 2, and pyruvate kinase isozyme M2) in HCT-116 cells in vitro. In addition, a xenograft model based on Balb/c mice demonstrated that the administration of either si-MALAT1 or miR-20b-5p-mimic suppressed the tumorigenicity of HCT-116 cells in vivo. The underlying mechanisms may involve the targeting of the tumor cell stemness maintenance-related factor Oct4 by miR-20b-5p. For the first time, we present the possible underlying effects of MALAT1 in influencing the stem cell-like properties of CRC cells. We propose that microRNAs and long noncoding RNAs have vital functions in mediating tumor stemness, which remain to be fully elucidated. K E Y W O R D S cancer stem cells, colorectal cancer, MALAT1, miR-20b-5p/Oct4 axis, stemness

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The creation of clean Li surfaces by vapor deposition and their subsequent interaction with oxygen have been studied by a combination of ellipsometry and Auger electron spectroscopy in ultrahigh vacuum. The ellipsometric parameters Δ and Ψ for Li thin films vapor‐deposited on a Ni substrate were monotonic functions of the film thickness, and in reasonable agreement with theoretical values calculated for dense (nonporous) films. The clean Li surface is very reactive toward oxygen, with essentially a sticking coefficient of unity at the initial stage of oxidation at 5×10−8 Torr 02 . Oxidation of the entire film (75 Å maximum) into Li20 proceeded with an approximately unit reaction probability. A model of oxidation with in‐plane contraction of the oxide film (continuously exposing fresh Li) is proposed to explain both the high rate of reaction and the observed variation of Δ and Ψ with time of exposure to O2 .

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The spectral properties of CO adsorbed on polycrystalline nickel electrodes in 0.1 M KOH have been examined using in situ potential difference Fourier transform infrared spectroscopy. The results obtained have shown that the voltammetric peak observed in the first linear scan in the positive direction for Ni(poly)/CO(ads) surfaces prepared by a special procedure is associated with the electrochemical oxidation of bridge-bonded CO to generate solution-phase carbonate as the only detectable product. No changes in the stretching frequency of CO (YCO) could be found as a function of potential in a region negative to the onset of CO oxidation. However, YCO shifted monotonically toward lower wavenumbers as the coverage of C O was reduced by electrooxidative stripping.