Modification of Multi-Component Building Blocks for Assembling Giant Chiral Lanthanide-Titanium Molecular Rings.

Building blocks with multiple components are promising for the synthesis of complex molecular assemblies, but are rarely available. Herein, we report a modification procedure for a multi-component building block [Ln3 Ti(HSA)6 (SA)4 (H2 O)]- ({Ln3 Ti-SA}, H2 SA=salicylic acid, Ln=Eu/Gd) to form new building blocks {Ln3 Tix -MSA} (H2 MSA=5-methoxysalicylic acid, x=1, 2, 3) by constructing [Ti(MSA)3 ]2- units. The obtained {Ln3 Tix -MSA} can further assemble into a chiral Ln22 Ti14 ring with the formulae [Eu22 Ti14 (MSA)48 (HMSA)22 (CH3 COO)4 (H2 O)10 (iPrOH)] and [Gd22 Ti14 (MSA)46 (HMSA)26 (CH3 COO)4 (H2 O)8 ]. Parallel experiments without Ti4+ result in linear Ln chains. Detailed analysis shows that the [Ti(MSA)4 ]4- unit makes the originally variable Ln chains become available building blocks and the modified [Ti(MSA)3 ]2- further triggers interesting chiral-sorting behavior. Finally, the electronic adsorption and magneto-optic responses of these molecular rings are investigated.

Potassium cobalt hexacyanoferrate as a peroxidase mimic for electrochemical immunosensing of Lactobacillus rhamnosus GG.

In this paper, the potassium cobalt hexacyanoferrate (II), K2CoFe(CN)6, with peroxidase-like activity was used for the fabrication of a novel label-free Lactobacillus rhamnosus GG (LGG) electrochemical immunosensor. The K2CoFe(CN)6 nanocubes were made by a simple hydrothermal method and followed by low-temperature calcination. In addition to structural characterization, the peroxidase-mimicking catalytic property of the material was confirmed by a chromogenic reaction. It is known that H2O2 can oxidize electroactive thionine molecules under the catalysis of horseradish peroxidase (HRP). In this nanozyme-based electrochemical immunoassay, due to the steric hindrance, the formation of immune-complex of LGG and LGG antibody on the modified GCE inhibits the catalytic activity of the peroxidase mimics of K2CoFe(CN)6 and thus reduced the current signal. Therefore, the developed electrochemical immunosensor achieved quantitative detection of LGG. Under optimal conditions, the linear range of the sensor was obtained from 101 to 106 CFU mL-1 with a minimum detection limit (LOD) of 12 CFU mL-1. Furthermore, the immunosensor was successfully applied in the quantitative detection of LGG in dairy product samples with recoveries ranging from 93.2% to 106.8%. This protocol presents a novel immunoassay method, which provides an alternative implementation pathway for the quantitative detection of microorganisms.

[Conductive keratoplasty for presbyopia and two years follow-up].

OBJECTIVE: To investigate the effect of conductive keratoplasty (CK) for presbyopia and 2 years follow-up. METHODS: This study is prospective clinical trial. CK was performed on 34 patients for presbyopia, in which 26 hyperopic patients underwent binocular operations and 8 emmetropic patients underwent monocular operation. The following-up time was 24 months. RESULTS: At 24 months postoperatively, for the hyperopia group, binocular uncorrected near visual acuity (33 cm) (5-logMAR) (4.63 ± 0.12) was increased significantly (t = 9.237, P < 0.001) compared pre-operatively (4.06 ± 0.15); binocular uncorrected distance visual acuity (4.99 ± 0.02) was significantly increased (t = 6.718, P < 0.05) compared pre-operatively (4.82 ± 0.21); for the emmetropia group, binocular uncorrected near visual acuity (33 cm) (5-logMAR) (4.68 ± 0.16) was increased significantly (t = 10.413, P < 0.001) compared pre-operatively (4.13 ± 0.18); binocular uncorrected distance visual acuity was same as pre-operative one; compared pre-operatively (+0.97 ± 0.63D), manifest refractive spherical equivalent was decreased significantly (P < 0.001) to peak value (-1.21 ± 1.00) D at 1 week, and then regressed to a relative plateau (-0.40 ± 0.70) D at 24 months; the regressive rate was decreased from (+0.35 ± 0.44) D/month at 1 month postoperatively to (+0.01 ± 0.01) D/months at 24 months postoperatively. Contrast sensitivity and glare sensitivity, intraocular pressure, tear break-up time, endothelial cell count, central corneal thickness, stereopsis function and best corrected visual acuity were not significantly changed. CONCLUSIONS: For treatment of presbyopia, CK appeared to be safe, effective, refractive-predictable and controllable, and relatively stable at 24 months post-operatively. More long-time follow-up is necessary for further evaluation.

The Genetic Diversity and Population Genetic Structure of the Red Panda, Ailurus fulgens, in Zoos in China.

In China, red pandas (Ailurus fulgens) have been raised in zoos for 60 years. It is very important to understand the genetic diversity and population genetic structure of the captive red pandas. Based on 19 microsatellite loci, we investigated genetic diversity and population genetic structure of 116 captive red pandas, with samples taken from 11 captive populations in China. Our results revealed a high genetic diversity among the populations, with mean allelic richness varying from 3.505 (Beijing) to 4.026 (Mianning), and expected heterozygosities varying from 0.631 (Huangshan) to 0.782 (Wenling). In particular, significant deviation from Hardy-Weinberg equilibrium was found in populations of Fuzhou and Jiangsu. The genetic differentiation index across all populations was 0.055, indicating a significant genetic differentiation among the 11 populations. These populations could be divided into three genetic clusters using a microsatellite-based Bayesian clustering analysis, which were consistent with the clustering results of wild populations. We conclude that the genetic diversity among captive red pandas is as high as that of the wild population. More attention should be paid to develop a proper and scientifically-based management program to avoid inbreeding and maintain a high genetic diversity in captive red pandas.