5-Hydr­oxy-1,7-bis­(1H-indol-3-yl)hepta-1,4,6-trien-3-one hemihydrate

The title compound, C23H18N2O2·0.5H2O, a derivative of the biologically active compound curcumin, crystallizes with two organic mol­ecules and a solvent water mol­ecule in the asymmetric unit. Each of the two independent mol­ecules is close to being planar (the dihedral angles between the indole ring systems are approximately 9 and 12°) and each exists in the keto–enol form. There is an intra­molecular O—H⋯O hydrogen bond between the keto and enol groups. In the crystal, the components interact by way of N—H⋯N, N—H⋯O and O—H⋯O hydrogen bonds

Direct measurement of the Raman enhancement factor of rhodamine 6G on graphene under resonant excitation

Graphene substrates have recently been found to generate Raman enhancement. Systematic studies using different Raman probes have been implemented, but one of the most commonly used Raman probes, rhodamine 6G (R6G), has yielded controversial results for the enhancement effect on graphene. Indeed, the Raman enhancement factor of R6G induced by graphene has never been measured directly under resonant excitation because of the presence of intense fluorescence backgrounds. In this study, a polarization-difference technique is used to suppress the fluorescence background by subtracting two spectra collected using different excitation laser polarizations. As a result, enhancement factors are obtained ranging between 1.7 and 5.6 for the four Raman modes of R6G at 611, 1,183, 1,361, and 1,647 cm[superscript −1] under resonant excitation by a 514.5 nm laser. By comparing these results with the results obtained under non-resonant excitation (632.8 nm) and pre-resonant excitation (593 nm), the enhancement can be attributed to static chemical enhancement (CHEM) and tuning of the molecular resonance. Density functional theory simulations reveal that the orbital energies and densities for R6G are modified by graphene dots.National Natural Science Foundation (China) (Nos. 21233001, 50972001, and 21129001)China. Ministry of Science and Technology (Nos. 2011YQ0301240201 and 2011CB932601)Beijing Natural Science Foundation (No. 2132056

A Novel CRYGD Mutation (p.Trp43Arg) Causing Autosomal Dominant Congenital Cataract in a Chinese Family

To identify the genetic defect associated with autosomal dominant congenital nuclear cataract in a Chinese family, molecular genetic investigation via haplotype analysis and direct sequencing were performed Sequencing of the CRYGD gene revealed a c.127T>C transition, which resulted in a substitution of a highly conserved tryptophan with arginine at codon 43 (p.Trp43Arg). This mutation co-segregated with all affected individuals and was not observed in either unaffected family members or in 200 normal unrelated individuals. Biophysical studies indicated that the p.Trp43Arg mutation resulted in significant tertiary structural changes. The mutant protein was much less stable than the wild-type protein, and was more prone to aggregate when subjected to environmental stresses such as heat and UV irradiation. © 2010 Wiley-Liss, Inc

ECOLOGICAL CHARACTERISTICS AND SUITABILITY EVALUATION OF FRITILLARIA CIRRHOSA D. DON BASED ON MAXENT MODEL

Background: As a rare and endangered medicinal plant growing in plateaus, Fritillaria cirrhosa D. Don is a scant resource in terms of quantity and planting regions. However, there is limited knowledge on predicting the potential ecological suitability of regions for the species with the climate factors. This paper evaluates the ecological suitability of F. cirrhosa D. Don on a global scale using Maxent. Materials and Methods: The ecologically suitable regions for F. cirrhosa D. Don around the world were evaluated using the maximum entropy model (Maxent), based on 127 known occurrence records and specific environmental predictor variables. Results: The Maxent model was highly accurate, with a statistically significant Area Under the Receiving Operator Curve (AUC) value of 0.993, and the most suitable areas and the suitable areas for F. cirrhosa D. Don were approximately 450,000 and 700,000 sq. km., respectively, including China, Pakistan, Nepal, and Bhutan. A quantitative study of the climatic characteristics of F. cirrhosa D. Don indicated that the period from May to October was critical for plant growth and development. Thus, the stable precipitation-temperature ratios (0.59 to 2.42) during this period could serve as a feature indicator for the geographical distribution of the plant. Conclusion: This work should be beneficial for the introduction and resource protection of F. cirrhosa D. Don, meanwhile, the analytical method could be expanded to predict the potential distribution of other medicinal plants

Landau Quantization of Massless Dirac Fermions in Topological Insulator

The recent theoretical prediction and experimental realization of topological insulators (TI) has generated intense interest in this new state of quantum matter. The surface states of a three-dimensional (3D) TI such as Bi_2Te_3, Bi_2Se_3 and Sb_2Te_3 consist of a single massless Dirac cones. Crossing of the two surface state branches with opposite spins in the materials is fully protected by the time reversal (TR) symmetry at the Dirac points, which cannot be destroyed by any TR invariant perturbation. Recent advances in thin-film growth have permitted this unique two-dimensional electron system (2DES) to be probed by scanning tunneling microscopy (STM) and spectroscopy (STS). The intriguing TR symmetry protected topological states were revealed in STM experiments where the backscattering induced by non-magnetic impurities was forbidden. Here we report the Landau quantization of the topological surface states in Bi_2Se_3 in magnetic field by using STM/STS. The direct observation of the discrete Landau levels (LLs) strongly supports the 2D nature of the topological states and gives direct proof of the nondegenerate structure of LLs in TI. We demonstrate the linear dispersion of the massless Dirac fermions by the square-root dependence of LLs on magnetic field. The formation of LLs implies the high mobility of the 2DES, which has been predicted to lead to topological magneto-electric effect of the TI.Comment: 15 pages, 4 figure

Adrenocortical carcinoma in patients with MEN1: a kindred report and review of the literature

Objective: Up to 40% of multiple endocrine neoplasia type 1 (MEN1) patients may have adrenal cortical tumors. However, adrenocortical carcinoma (ACC) is rare. The clinical manifestations, prevalence, inheritance and prognosis of ACC associated with MEN1 remain unclear. Here we report the clinical manifestations and prevalence of ACC in patients with MEN1. Design and methods: A retrospective analysis of ACC associated with MEN1 patients at a single tertiary care center from December 2001 to June 2017. Genetic analysis of MEN1 and other ACC associated genes, loss of heterozygosity (LOH) of MEN1 locus, immunohistochemistry staining of menin, P53 and β-catenin in ACC tissue were performed. Results: Two related patients had ACC associated with MEN1. The father had ENSAT stage IV tumor with excessive production of cortisol; the daughter had nonfunctional ENSAT stage I tumor. Both patients carried novel germline heterozygous mutation (c.400_401insC) of MEN1. The wild-type MEN1 allele was lost in the resected ACC tissue from the daughter with no menin staining. The ACC tissue had nuclear β-catenin staining, with heterozygous CTNNB1 mutation of 357del24 and P53 staining in only 20% cells. Conclusions: ACC associated with MEN1 is rare and may occur in familial aggregates

A Comprehensive Analysis of Fermi Gamma-ray Burst Data: III. Energy-Dependent T90 Distributions of GBM GRBs and Instrumental Selection Effect on Duration Classification

The durations (T90) of 315 GRBs detected with Fermi/GBM (8-1000 keV) by 2011 September are calculated using the Bayesian Block method. We compare the T90 distributions between this sample and those derived from previous/current GRB missions. We show that the T90 distribution of this GRB sample is bimodal, with a statistical significance level being comparable to those derived from the BeppoSAX/GRBM sample and the Swift/BAT sample, but lower than that derived from the CGRO/BATSE sample. The short-to-long GRB number ratio is also much lower than that derived from the BATSE sample, i.e., 1:6.5 vs 1:3. We measure T90 in several bands, i.e., 8-15, 15-25, 25-50, 50-100, 100-350, and 350-1000 keV, to investigate the energy-dependence effect of the bimodal T90 distribution. It is found that the bimodal feature is well observed in the 50-100 and 100-350 keV bands, but is only marginally acceptable in the 25-50 keV and 350-1000 keV bands. The hypothesis of the bimodality is confidently rejected in the 8-15 and 15-25 keV bands. The T90 distributions in these bands are roughly consistent with those observed by missions with similar energy bands. The parameter T90 as a function of energy follows \bar T90 \propto E^{-0.20\pm 0.02} for long GRBs. Considering the erratic X-ray and optical flares, the duration of a burst would be even much longer for most GRBs. Our results, together with the observed extended emission of some short GRBs, indicate that the central engine activity time scale would be much longer than T90} for both long and short GRBs and the observed bimodal T90 distribution may be due to an instrumental selection effect.Comment: 29 pages, 2 tables, 9 figures, accepted for publication in Ap