Homogeneous point mutation detection by quantum dot-mediated two-color fluorescence coincidence analysis

This report describes a new genotyping method capable of detecting low-abundant point mutations in a homogeneous, separation-free format. The method is based on integration of oligonucleotide ligation with a semiconductor quantum dot (QD)-mediated two-color fluorescence coincidence detection scheme. Surface-functionalized QDs are used to capture fluorophore-labeled ligation products, forming QD-oligonucleotide nanoassemblies. The presence of such nanoassemblies and thereby the genotype of the sample is determined by detecting the simultaneous emissions of QDs and fluorophores that occurs whenever a single nanoassembly flows through the femtoliter measurement volume of a confocal fluorescence detection system. The ability of this method to detect single events enables analysis of target signals with a multiple-parameter (intensities and count rates of the digitized target signals) approach to enhance assay sensitivity and specificity. We demonstrate that this new method is capable of detecting zeptomoles of targets and achieve an allele discrimination selectivity factor >10(5)

Biological Evaluation of an Antibiotic DC-81–Indole Conjugate Agent in Human Melanoma Cell Lines

Pyrrolo[2, 1-c][1, 4]benzodiazepines (PBDs) are potent inhibitors of nucleic acid synthesis because of their ability to recognize and bind to specific sequences of DNA and form a labile covalent adduct. DC-81, an antitumor antibiotic produced by Streptomyces species, is a PBD. We combined DC-81 and an indole carboxylate moiety to synthesize a hybrid designed to have much higher sequence selectivity in DNA interactivity. In this paper, the cytotoxic potency of the hybrid in human melanoma cell lines was studied. XTT assay demonstrated that the DC-81-indole conjugate possessed cytotoxicity against human melanoma cell lines

[4-(1-Benzofuran-2-yl)phen­yl]diphenyl­amine

The asymmetric unit of the title compound, C26H19NO, contains two mol­ecules. The dihedral angles between the benzofuran and benzene rings are 5.09 (8), 59.02 (8) and 67.74 (8)° in one mol­ecule and 18.70 (8), 52.78 (8) and 41.74 (8)° in the other. Weak inter­molecular C—H⋯π inter­actions help to stabilize the molecular structure

Multiple Unpinned Dirac Points in Group-Va Single-layers with Phosphorene Structure

Emergent Dirac fermion states underlie many intriguing properties of graphene, and the search for them constitute one strong motivation to explore two-dimensional (2D) allotropes of other elements. Phosphorene, the ultrathin layers of black phosphorous, has been a subject of intense investigations recently, and it was found that other group-Va elements could also form 2D layers with similar puckered lattice structure. Here, by a close examination of their electronic band structure evolution, we discover two types of Dirac fermion states emerging in the low-energy spectrum. One pair of (type-I) Dirac points is sitting on high-symmetry lines, while two pairs of (type-II) Dirac points are located at generic $k$-points, with different anisotropic dispersions determined by the reduced symmetries at their locations. Such fully-unpinned (type-II) 2D Dirac points are discovered for the first time. In the absence of spin-orbit coupling, we find that each Dirac node is protected by the sublattice symmetry from gap opening, which is in turn ensured by any one of three point group symmetries. The spin-orbit coupling generally gaps the Dirac nodes, and for the type-I case, this drives the system into a quantum spin Hall insulator phase. We suggest possible ways to realize the unpinned Dirac points in strained phosphorene.Comment: 30 pages, 6 figure

Significant association of hematinic deficiencies and high blood homocysteine levels with burning mouth syndrome

Background/PurposeBurning mouth syndrome (BMS) is characterized by a burning sensation of the oral mucosa in the absence of clinically apparent mucosal alterations. In this study, we evaluated whether there was an intimate association of the deficiency of hemoglobin (Hb), iron, vitamin B12, or folic acid; high blood homocysteine level; and serum gastric parietal cell antibody (GPCA) positivity with BMS.MethodsBlood Hb, iron, vitamin B12, folic acid, and homocysteine concentrations and the serum GPCA level were measured in 399 BMS patients and compared with the corresponding levels in 399 age- and sex-matched healthy control individuals.ResultsWe found that 89 (22.3%), 81 (20.3%), 10 (2.5%), and six (1.5%) BMS patients had deficiencies of Hb (men: <13 g/dL, women: <12 g/dL), iron (<60 μg/dL), vitamin B12 (<200 pg/mL), and folic acid (<4 ng/mL), respectively. Moreover, 89 (22.3%) BMS patients had abnormally high blood homocysteine level and 53 (13.3%) had serum GPCA positivity. BMS patients had a significantly higher frequency of Hb, iron, or vitamin B12 deficiency; of abnormally elevated blood homocysteine level; or of serum GPCA positivity than the healthy control group (all p < 0.001 except for vitamin B12 deficiency, for which p = 0.004). However, no significant difference in frequency of folic acid deficiency (p = 0.129) was found between BMS patients and healthy control individuals.ConclusionWe conclude that there is a significant association of deficiency of Hb, iron, and vitamin B12; abnormally high blood homocysteine level; and serum GPCA positivity with BMS

Seasonal Variation and Source Apportionment of Atmospheric Carbonyl

ABSTRACT The concentrations of 18 atmospheric carbonyls species were measured at Nan-Chie and Hsiung-Kong sites in Kaohsiung City, Taiwan, during the summer and winter of 2006. Formaldehyde and acetaldehyde were the most abundant carbonyls with respective annual mean concentrations of 17.99 g/m 3 and 13.69 g/m 3 at Nan-Chie, and 21.47 g/m 3 and 16.68 g/m 3 at Hsiung-Kong; altogether the two species accounted for approximately 56-57% of total carbonyls. In summer, the total concentrations of carbonyls were 74.06 g/m 3 and 89.99 g/m 3 at Nan-Chie and Hsiung-Kong, respectively. In winter, the concentrations were 37.14 g/m 3 and 46.50 g/m 3 at Nan-Chie and Hsiung-Kong, respectively. Measured results indicated the predominance of photolysis and photooxidation reactions of aldehydes in summer. In this study, receptor models using principal component analysis (PCA) and absolute principal component scores (APCS) suggest that the primary pollution sources at Nan-Chie in the summer were secondary emissions/vehicle exhausts (gasoline engines)/stationary emissions (food industry), stationary emissions (petrochemical)/waste treatment and restaurant emissions; the primary pollution sources at Nan-Chie in winter were vehicle exhausts (gasoline engines)/stationary emissions (petrochemical) and restaurant emissions. At Hsiung-Kong, the primary pollution sources in summer were secondary emissions/vehicle exhausts (gasoline engines and diesel engines)/stationary emissions (metal assembly), restaurant emissions and others; the primary pollution sources in winter were vehicle exhausts (gasoline engines)/restaurant emissions and vehicle exhausts (diesel engines)/stationary emissions (metal assembly)

Food Supplement 20070721-GX May Increase CD34+ Stem Cells and Telomerase Activity

Few rejuvenation and antiaging markers are used to evaluate food supplements. We measured three markers in peripheral blood to evaluate the antiaging effects of a food supplement containing placental extract. Samples were evaluated for CD34+ cells, insulin-like growth factor 1 (IGF1), and telomerase activity, which are all markers related to aging. To control the quality of this food supplement, five active components were monitored. In total, we examined 44 individuals who took the food supplement from 1.2 months to 23 months; the average number of CD34+ cells was almost 6-fold higher in the experimental group compared with the control group. Food supplement intake did not change serum IGF1 levels significantly. Finally, the average telomerase activity was 30% higher in the subjects taking this food supplement. In summary, our results suggest that the placental extract in the food supplement might contribute to rejuvenation and antiaging