In this paper, we describe a new way to generate molecular probes for specific recognition of cancer cells. Molecular medicine will require a large number of probes for molecular recognition and characterization of a variety of diseased cells. Aptamers, single-stranded DNA/RNA probes, are poised to become a chemist's antibody and have the potential to serve as molecular probes for a variety of biomedical applications. By applying newly developed cell-SELEX (cell-based systematic evolution of ligands by exponential enrichment) against whole living cells, panels of aptamers have been evolved from an initial DNA library to characterize target cells at the molecular level. Ramos cells, a B-cell lymphoma cell line, were used as target cells for the generation of effective molecular probes. By taking advantages of the repetitive and broad enrichment strategy, the selected aptamers could bind to target cells and other closely related cell lines in variant patterns with an equilibrium dissociation constant (Kd) in the nanomolar range. Some aptamers could also specifically recognize the target lymphoma cells mixed with normal human bone marrow aspirates. The cell-based SELEX is simple, fast, and robust. The strategies used here will be highly useful for aptamer selection against complex target samples in order to generate a large number of aptamers in a variety of biomedical and biotechnological applications, paving the way for molecular diagnosis, therapy, and biomarker discovery.

An alkali-metal-doped effect on the nonlinear optical (NLO) property in new electrides is studied. The electrides are formed by doping alkali atom Li into a fluorocarbon chain H-(CF2-CH2)3-H. Six stable structures of the Lin-H-(CF2-CH2)3-H (n = 1, 2) complexes with all real frequencies are obtained at the MP2/6-31+G (d) level. Among these six structures, the largest first static hyperpolarizabilities (beta(0)) are found to be 76,978 au, which is much larger than the beta(0) value of 112 au for H-(CF2-CH2)3-H. Clearly, the Li-atom-doped effect on the first hyperpolarizability is dramatic. Three interesting relationships between the structure and beta(0) value have been observed. (1) For the one-Li-atom-doped systems as well as for the structures with two opposite Li atoms, the shorter the distance between the Li atom and difluoromethyl group, the larger the beta(0) value. (2) The beta(0) values of the two-Li-atom-doped chains are much larger than those of the one-Li-atom-doped systems, except for the case of cis-AB where the Li-Li distance (2.847 Angstrom) is close to the bond length of the Li2 molecule (2.672 Angstrom). (3) For the two-Li-atom-doped chains, the beta(0) value increases as the Li-Li distance increases. These relationships between the structure and beta(0) value may be beneficial to experimentalists for designing electrides with large NLO responses by using the alkali-metal-doped effect.

Citrus limonoids were studied as inducers of the detoxifying enzyme system glutathione S-transferase in mice. Among eight limonoids studied, nomilin was shown to be the most potent inducer in the liver and in the small intestinal mucosa. In the forestomach, the inducing activity was low but the enzyme activity was significantly elevated when compared with that of the control. In the lung and colon no appreciable enzyme activity was induced by nomilin. Three other limonoids, obacunone, isoobacunoic acid, and ichangin, were shown to be enzyme inducers in the liver and some other tissues studied. Limonin, on the other hand, showed only marginal activity as an enzyme inducer in the small intestinal mucosa and was inactive in all other tissues studied. Limonol showed small inducing activity in the forestomach while deoxylimonin was not active in any of the tissues examined. Since anticarcinogens such as nomilin and kahweol are potent inducers of detoxifying enzymes, citrus limonoids such as obacunone, isoobacunoic acid, and others may be effective inhibitors of chemically induced carcinogenesis.Limonoids are a group of chemically related triterpene derivatives found in the Rutaceae and Meliaceae families.

Novel organic-inorganic mesoporous luminescent hybrid materials were prepared by linking the binary and ternary Eu 3+ complexes to the functionalized ordered mesoporous SBA-15 with the modified 1-(2-naphthoyl)-3,3,3-trifluoroacetonate (NTA) by co-condensation of tetraethoxysilane (TEOS) in the presence of Pluronic P123 surfactant as a template. 1-(2-Naphthoyl)-3,3,3-trifluoroacetonate (NTA) grafted to the coupling agent 3-(triethoxysilyl)propyl isocyanate (TEPIC) was used as the precursor for the preparation of mesoporous materials. SBA-15 consisting of the highly luminescent ternary complex Eu(NTA) 3 bpy covalently bonded to the silica-based network, which was designated as Eu(NTA-SBA-15) 3 bpy, was obtained by introducing EuCl 3 and 2,2′-bipyridine (bpy) complex into the hybrid material via a ligand-exchange reaction. In addition, for comparison, SBA-15 doped with Eu(NTA) 3 ‚2H 2 O and Eu(NTA) 3 bpy complexes and SBA-15 covalently bonded with the binary Eu 3+ complex with NTA ligand were also synthesized, denoted as Eu(NTA) 3 /SBA-15, Eu-(NTA) 3 bpy/SBA-15, and Eu(NTA-SBA-15) 3 , respectively. The luminescence properties of these resulting materials were characterized in detail, and the results reveal that they all have high surface area, uniformity in the mesostructures, and crystallinity. The efficient intramolecular energy transfer in mesoporous material Eu(NTA-SBA-15) 3 bpy mainly occurs between the modified ligand NTA-Si and the central Eu 3+ ion. Furthermore, Eu(NTA-SBA-15) 3 bpy exhibited the characteristic emission of Eu 3+ ion under UV irradiation with higher 5 D 0 luminescence quantum efficiency than the pure Eu(NTA) 3 bpy complex and the other materials. Thermogravimetric analysis on the mesoporous material Eu(NTA-SBA-15) 3 bpy indicated that the thermal stability of the complex was improved as it was covalently bonded to the host SBA-15 matrix.

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Phosphorous doped carbon dots (P-CDs), prepared by a one-step hydrothermal method, show the phenomenon of aggregation induced red shift emission (AIRSE).

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Gastric cancer is one of the most prevalent and aggressive cancers worldwide, and its molecular mechanism remains largely elusive. Here we report the genomic landscape in primary gastric adenocarcinoma of human, based on the complete genome sequences of five pairs of cancer and matching normal samples. In total, 103,464 somatic point mutations, including 407 nonsynonymous ones, were identified and the most recurrent mutations were harbored by Mucins (MUC3A and MUC12) and transcription factors (ZNF717, ZNF595 and TP53). 679 genomic rearrangements were detected, which affect 355 protein-coding genes; and 76 genes show copy number changes. Through mapping the boundaries of the rearranged regions to the folded three-dimensional structure of human chromosomes, we determined that 79.6% of the chromosomal rearrangements happen among DNA fragments in close spatial proximity, especially when two endpoints stay in a similar replication phase. We demonstrated evidences that microhomology-mediated break-induced replication was utilized as a mechanism in inducing ~40.9% of the identified genomic changes in gastric tumor. Our data analyses revealed potential integrations of Helicobacter pylori DNA into the gastric cancer genomes. Overall a large set of novel genomic variations were detected in these gastric cancer genomes, which may be essential to the study of the genetic basis and molecular mechanism of the gastric tumorigenesis.