Selective ratiometric fluorescence detection of hypochlorite by using aggregation-induced emission dots.

The development of simple and effective tools for selective ratiometric detection of hypochlorite (ClO-) is one of the most important goals for elucidating the biofunction of ClO- in associated diseases. However, most developmental probes suffer from the notorious aggregation-caused quenching (ACQ) effect that greatly limits their applications. Herein, we report on novel aggregation-induced emission dots (AIED) for ratiometric detection of ClO- via a co-precipitation strategy. The AIED nanoprobe displayed a ratiometric signal output, which was more promising to minimize the bad environmental factors and simultaneously avoided the ACQ effect. Notably, amphiphilic block copolymer endowed the nanoprobe with stable water dispersibility and easy modification. The as-prepared AIED probe exhibited high sensitivity (~ 89 nM), high selectivity, outstanding photostability, and prominent long-term fluorescence stability. Furthermore, the as-prepared AIED was applied for the visualized fluorescence detection of ClO- and further utilized to detect ClO- in real samples. We expect the nanoprobe to be an outstanding tool to understand ClO--associated diseases. Graphical abstract Illustration of the probe for the detection of ClO-.

Unique Steric Effect of Geminal Bis(silane) To Control the High Exo-selectivity in Intermolecular Diels-Alder Reaction.

The unique steric effect of geminal bis(silane) [(R3Si)2CH] allows an exo-selective intermolecular Diels-Alder reaction of geminal bis(silyl) dienes with α,ß-unsaturated carbonyl compounds. The approach shows good generality to form ortho-trans cyclohexenes in good yields with high exo-selectivity and high enantioselectivity in some asymmetric cases. The excellent exo-stereocontrol aptitude of (R3Si)2CH group is highlighted by comparing with R3SiCH2 and R3Si groups, which leads to endo-selectivity predominantly. The conformational analysis of dienes suggests that (R3Si)2CH group effectively shields both sides of the diene moiety, ensuring the desired exo-selectivity. Moreover, the geminal bis(silane) can be further functionalized to transform the resulting ortho-trans cycloadducts into useful synthons, which makes the approach hold great potential for organic synthesis.

K2CO3-mediated synthesis of functionalised 4-substituted-2-amino-3-cyano-4H-chromenes via Michael-cyclization reactions.

An efficient approach for the synthesis of functionalized 4-substituted-2-amino-3-cyano-4H-chromenes moderate to high yields (up to 98%) has been achieved via a tandem K2CO3 catalyzed conjugate addition-cyclization reaction of malononitrile and a range of Knoevenagel adducts previously formed from oxindole, pyrazolone, nitromethane, N,N-dimethylbarbituric acid or indanedione. This methodology differs from the previous classical methods in its simplicity and ready availability of the catalyst.

NCK1-AS1 enhances glioma cell proliferation, radioresistance and chemoresistance via miR-22-3p/IGF1R ceRNA pathway.

Glioma is the deadliest disease in human central nerve system. Abnormal expression of long noncoding RNA (lncRNA) expression has been demontrated to be implicated in various cancers. The oncogenic role of lncRNA NCK1-AS1 has been validated in cervical cancer, wheras its role in glioma remians obscure. Our research findings suggested that NCK1-AS1 was upregulated in glioma tissues and cells. NCK1-AS1 deficiency hindered cell proliferation and enhanced cell apoptosis. Additionally, the chemoresistance and radioresistance of glioma cells were impaired by NCK1-AS1 depletion. Moreover, miR-22-3p, a downstream gene of NCK1-AS1, could weaken glioma cell chemoresistance and radioresistance. Similarly, IGF1R was the downstream target gene of miR-22-3p. Further mechanism and function assays demonstrated that NCK1-AS1 promoted glioma cell growth, chemoresistance and radioresistance via sponging miR-22-3p to upregulate IGF1R. Finally, the tumor facilitator function of NCK1-AS1 was also verified by in vivo experiments. Taken together, NCK1-AS1 contributes to glioma cell proliferation, radioresistance and chemoresistance via miR-22-3p/IGF1R ceRNA pathway, which might provide a new insight for improving the radiotherapy and chemotherapy treatments of glioma.

TMSBr/InBr3-promoted Prins cyclization/homobromination of dienyl alcohol with aldehyde to construct cis-THP containing an exocyclic E-alkene.

A TMSBr/InBr3-promoted Prins cyclization/homobromination reaction of dienyl alcohol with aldehyde has been developed to construct a unique cis-E THP shown as the A ring in (-)-exiguolide and the B ring in bryostatins.

1,4-Hydroiodination of dienyl alcohols with TMSI to form homoallylic alcohols containing a multisubstituted Z-alkene and application to Prins cyclization.

A regioselective 1,4-hydroiodination of dienyl alcohols has been developed using trimethylsilyl iodide as Lewis acid and iodide source. A range of homoallylic alcohols containing a multisubstituted Z-alkene was synthesized with good to excellent configurational control. The approach was applied in sequential hydroiodination/Prins cyclization to afford multisubstituted tetrahydropyrans diastereoselectively.

[The analysis of UV absorption spectrum and X-ray diffraction spectrum of Sn-doped C60 thin films].

In this article, We report our measured results of UV-Vis absorption, X-ray diffraction and scanning electron microscope for Sn-doped C60 thin film. The results show the two absorption peaks in respective short wave range of UV absorption have an apparent decline after doping Sn, and the position of three absorption peaks have a slightly shift respectively to red wave direction. The electron absorption transition of Sn-C60 film is indirect transition, and there are impurity levels in the energy band; X-ray diffraction shows that the crystal structure of Sn-C60 film is f. c. c. The film is in the form of tiny drops in nano magnitude.

[Raman spectra of carbon nanotubes produced in different inert atmosphere and their pressures].

Carbon nanotubes are produced in two kinds of inert atmosphere at the pressure range of 11 to 92 kPa by arc discharge. First- and second-order Raman spectra of these samples have been measured and compared with each other. It is found that the position and bandwidth of the spectral lines depend on the kind of inert gases and their pressure. The Raman spectra of the nanotubes produced in argon gas are much more similar to that of polycrystalline graphite than those of the nanotubes produced in helium gas. The position and bandwidth of nanotubes Raman peaks also change with gas pressure in arc discharge. The Raman spectra of nanotubes produced in high pressure are much more like the graphite than those produced in lower pressure.

Brainstem tethering with Ondine's curse.

BACKGROUND: Brainstem tethering is a rare disease. CASE DESCRIPTION: We report and discuss a 20-year-old patient who experienced paroxysmal apnea (a symptom of Ondine's curse) during sleeping, causing him to wake up and control his breathing consciously. A magnetic resonance imaging study revealed that his medulla oblongata was twisted and displaced posteriorly by an abnormal tissue cord. An operation was performed to detether the tethered brainstem, with a satisfying result reached. CONCLUSION: Brainstem tethering is a rare but late complication of occipital encephalocele with insufficient operation. The symptoms of this disease are related to the dysfunction of the medulla oblongata and their adjunctive nerves. Magnetic resonance imaging can be used to identify the abnormal region and distinguish it from other medulla oblongata diseases. Surgery in the early stage of the brainstem tethering is helpful, but ventriculoperitoneal shunting is unnecessary or cannot be performed before detethering, although these patients usually have ventricular dilation.