Enhanced Fluorescence of 3,3′-Diformyl BINOL by Functional Secondary Amines

Although 3,3′-diformylBINOL (<i>S</i>)-1 shows little change in its fluorescence when treated with primary amines, its fluorescence can be greatly enhanced by using functional secondary amines including β- and γ-amino alcohols and 1,2- and 1,3-bis­(secondary amine) compounds. It has been demonstrated that the functional secondary amines react with (<i>S</i>)-<b>1</b> to convert the conjugated aldehyde groups to unconjugated oxazolidines or aminals to turn on the fluorescence

A Two-Step Synthetic Strategy toward Monodisperse Colloidal CdSe and CdSe/CdS Core/Shell Nanocrystals

CdSe magic-size clusters with close-shell surface and fixed molecular formula are well-known in the size range between ∼1 and 3 nm. By applying high concentration of cadmium alkanoates as ligands, a conventional synthetic system for CdSe nanocrystals was tuned to discriminate completion from initiation of atomic flat facets. This resulted in ∼4–13 nm CdSe nanocrystals with hexahedral shape terminated with low-index facets, namely three (100), one (110), and two (111) facets. These low-symmetry (<i>C</i>_<i>s</i> group with single mirror plane) yet monodisperse hexahedra were found to be persistent not only in a broad size range but also under typical synthetic temperatures for growth of both CdSe and CdS. Atomic motion on the surface of the nanocrystals under enhanced ligand dynamics initiated intraparticle ripening without activating interparticle ripening, which converted the hexahedral nanocrystals to monodisperse spherical ones. This new synthetic strategy rendered optimal color purity of photoluminescence (PL) of the CdSe and CdSe/CdS core/shell nanocrystals, with the ensemble PL peak width comparable with that of a corresponding single dot

Optofluidic laser based on a hollow-core negative-curvature fiber

An optofluidic laser based on a hollow-core negative-curvature fiber (HC-NCF) is proposed and demonstrated. The submicron-thick circular capillary tubes embedded in the cladding of the HC-NCF act as antiresonant elements and are used as both a resonator and dye microfluidic channels. A stable optofluidic dye laser with a low threshold of 15.14 nJ/mm2 is achieved. The laser is compact and robust and exhibits directional output

Rational Design of a Fluorescent Sensor to Simultaneously Determine Both the Enantiomeric Composition and the Concentration of Chiral Functional Amines

A fluorescent molecular probe, a 1,1′-bi-2-naphthol (BINOL)-based bis­(naphthylimine) compound (<i>R</i>)-<b>4</b>, is designed to exhibit very different fluorescent responses at two emission wavelengths toward a variety of chiral functional amines including diamines, amino alcohols, and amino acids. At one emission wavelength (λ₁), it shows high sensitivity toward the substrates, and at another wavelength (λ₂), it shows high enantioselectivity. This is the first rational design of such a dual responsive fluorescent sensor which can be used to simultaneously determine both the concentration and the enantiomeric composition of functional chiral amines by one fluorescent measurement. This strategy is potentially generally applicable for the construction of sensors for rapid assay of structurally diverse chiral substrates. When (<i>R</i>)-<b>4</b> is treated with various chiral functional amines in the presence of Zn­(OAc)₂, its 2-naphthylamine units are displaced off to show large fluorescent enhancement at λ₁ = 427 nm (<i>I</i>₁) due to the restored emission of 2-naphthylamine. The combination of the remaining chiral binaphthyl unit with the chiral substrates leads to highly enantioselective fluorescent enhancement at λ₂ > 500 nm (<i>I</i>₂). Since <i>I</i>₁ is only concentration dependent but independent of the chiral configuration, it allows the determination of the substrate concentration. The highly enantioselective <i>I</i>₂ allows the determination of the enantiomeric composition. Thus, using one fluorescent probe with one fluorescent measurement, both the concentration and the enantiomeric composition are determined. The dual responsive mechanism of (<i>R</i>)-<b>4</b> is studied by using various spectroscopic methods including fluorescence, UV–vis, NMR, and mass analyses

Genetic variants in PVRL2-TOMM40-APOE region are associated with human longevity in a Han Chinese population.

Human longevity results from a number of factors, including genetic background, favorable environmental, social factors and chance. In this study, we aimed to elucidate the association of human longevity with genetic variations in several major candidate genes in a Han Chinese population.A case-control association study of 1015 long-lived individuals (aged 90 years or older) and 1725 younger controls (30-70 years old) was undertaken. Rs2075650 in TOMM40 was firstly genotyped using the ABI SNaPshot method in an initial cohort consisted of 597 unrelated long-lived individuals and 1275 younger controls enrolled from Sichuan. Secondly, eighteen tag single-nucleotide polymorphisms (SNPs) in the PVRL2-TOMM40-APOE locus were genotyped for extensive study in the same cohort. Finally, 5 associated SNPs were genotyped in a replication cohort including 418 older individuals and 450 younger controls. The genotype and allele frequencies were evaluated using the χ2 tests. The linkage disequilibrium (LD) block structure was examined using the program Haploview.The case-control study of rs2075650 in TOMM40 showed significant difference in allele frequencies between cases and controls (P = 0.006) in an initial study. Of the 18 SNPs genotyped, rs405509 in APOE and another three SNPs (rs12978931, rs519825 and rs395908) in the PVRL2 gene also showed significant association with human longevity in extensive study in the same cohort. Rs2075650 in TOMM40, rs405509 in APOE and rs519825 in PVRL2 showed a significant association with human longevity in a replication cohort.These results suggested that PVRL2, TOMM40 and APOE might be associated with human longevity. However, further research is needed to identify the causal variants and determine which of these genes are involved in the progress of human longevity