A Modular Approach for Diversity-Oriented Synthesis of 1,3-trans-Disubstituted Tetrahydroisoquinolines: Seven-Step Asymmetric Synthesis of Michellamines†B and C.

1,3-trans-Disubstituted tetrahydroisoquinoline (THIQ) is a common heterocyclic structural unit of naphthylisoquinoline alkaloids. The assembly of this structural unit is not trivial, which constitutes a substantial challenge in the total synthesis of naphthylisoquinoline alkaloids and related pharmaceuticals. Herein, we report a modular and convergent method for the rapid assembly of 1,3-trans-disubstituted THIQ frameworks through a three-component Catellani reaction and a AuI -catalyzed cyclization/reduction cascade. With widely available simple aryl iodides, aziridines and (triisopropylsilyl)acetylene as the building blocks, this method paves a practical way for the diversity-oriented synthesis of 1,3-trans-disubstituted THIQs. Based on this new method, concise syntheses of an analogue of the new drug mevidalen and four naphthylisoquinoline alkaloids have been accomplished, demonstrating the broad synthetic utility of this approach.

Boosting zinc ion storage performance of sandwich-like V2O5/graphene composite by effectively inhibiting vanadium dissolution.

Improving the stability of the layered structure and suppressing vanadium dissolution during repeated Zn2+ insertion/extraction processes are considered to be the key to promote the electrochemical stability of vanadium-based cathodes for ZIBs. In this work, a group of sandwich-like V2O5/graphene composites (V2O5/xG) were controllably fabricated by tuning the amount of hydrophobic graphene. With the increase of graphene content, the corresponding electrochemical properties show a parabolic trend that increase first and then decrease. A maximum capacity of 270 mAh g-1 after 100 cycles at 0.1 A g-1 and a superior cycle stability with 82.4% capacitance retention after 6000 cycles at 10 A g-1 are achieved when the amount of graphene is about 10.4% (that is V2O5/5G). The addition of graphene has been proven not only to act as an effective conductive network to promote charge transfer and enhance the pseudocapacitance effect on the electrode surface; but also to increase the electrode hydrophobicity, effectively inhibiting the dissolution of vanadium, and promoting the desolvation and diffusion kinetics of hydrated zinc ions. Moreover, the graphene layer, as a structural stabilizer, effectively prevents the structure of the active component V2O5 from collapsing during cycling, contributing to the long-term cycle life.

Turning Pore Size of Silica-Based Nano-TiO2 for Treating Cyanide Wastewater.

Cyanide wastewater is a very highly toxic substance. In this study, a kind of silicon-based nano-TiO2 material by turning pore size accurately is prepared to treat cyanide wastewater. The materials are characterized by XRD, TG analysis, N2 adsorption/desorption test, UVAS analysis and TEM. Results show that adding NaCl to the synthesis of silica supports can change the size of pores. It emerges that pore size can affect the catalytic performance of the material. Catalytic experiments confirm that cyanide has the best catalytic effect when it has a pore size of 16.47 nm. UVAS spectrum demonstrate that the cyanide has been broken down rather than adsorbed onto the material.

Synergistic effect of adsorptive photocatalytic oxidation and degradation mechanism of cyanides and Cu/Zn complexes over TiO2/ZSM-5 in real wastewater.

The treatment of cyanide wastewater from the gold industry is essential. Photocatalytic oxidation is an effective method for the elimination of cyanides and metal cyanide complexes. TiO2/ZSM-5 composite photocatalysts with different SiO2/Al2O3 ratios were prepared using the solid-state dispersion (SSD) method. The composite catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption, and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The catalytic efficiency of different SiO2/Al2O3 ratios and the synergistic effect of adsorptive photocatalytic oxidation for the degradation of cyanide wastewater was investigated under different adsorption and illumination times. With the extension of the photocatalytic time (>2.0 h), the composite catalyst with a high SiO2/Al2O3 ratio had better photocatalytic performance. A 93.97% degradation efficiency of total cyanides was observed after adsorption for 3.0 h and illumination for 4.0 h under room temperature with air as the oxidant. The removal efficiencies of the copper and zinc ions were 81.67% and 100%, respectively. The degradation of cyanide followed pseudo-first-order kinetics. Energy dispersive spectroscopy (EDS) results showed that the generally irregular surface of the catalyst with a high SiO2/Al2O3 ratio contains more nano-TiO2. The adsorption capacities of copper and zinc were relatively high. X-ray photoelectron spectroscopy (XPS) suggested that cyanide was eventually degraded to CO2 and NO3-. Copper and zinc were removed in the form of Cu(II) and Zn(II).

Monoclinic VO2(D) hollow nanospheres with super-long cycle life for aqueous zinc ion batteries.

Vanadium dioxide (VO2) is a very promising cathode material for aqueous zinc ion batteries (AZIBs) because of its high reversible specific capacity, excellent rate performance and fast diffusion kinetics. However, its long-term cycle stability and compatibility with electrolytes have not met expectations. In this study, another metastable phase of vanadium dioxide-monoclinic VO2(D)-is demonstrated to be a better choice as a cathode for AZIBs. Electrochemical results revealed that the as-prepared VO2(D) hollow nanospheres delivered high reversible discharge capacity (up to 408 mA h g-1 at 0.1 A g-1), exceptional rate performance (200 mA h g-1 at 20 A g-1), and long cyclic endurance stability (cycling for 30 000 cycles with a low capacity fading rate of 0.0023% per cycle) in inexpensive 3 M ZnSO4 electrolyte. Furthermore, the electrochemical reaction mechanism was corroborated using ex situ XRD, HRTEM and XPS, showing that an interesting electrochemically induced phase transition from VO2(D) to V2O5·xH2O occured with the insertion/extraction of zinc ions. Finally, the prototype batteries assembled with our as-prepared VO2(D) hollow nanospheres and the impressive performance of this electrode under high active material mass loading further reveal its high potential in practical applications.

Pediatric reference intervals in China (PRINCE): design and rationale for a large, multicenter collaborative cross-sectional study.

There is a lack of accurate pediatric reference intervals (RIs) in China, with most commonly used RIs established without consideration of the effect of age and gender. The Pediatric Reference Intervals in China (PRINCE) project aims to establish and verify pediatric RIs for 31 common laboratory measurands. The project will be a large, multicenter cross-sectional study: 14,490 healthy children and adolescents aged up to 19 years will be surveyed by 10 children's hospitals and one pediatric department of a university hospital. To evaluate the feasibility and efficiency of the study methods, 602 children were surveyed in the pilot phase of the PRINCE study in April 2017: it found that some measurands were distinctly age dependent and that there were differences between values for males and females. The results of the pilot study affirmed the necessity of the PRINCE project for Chinese pediatrics. The pilot also indicated potential difficulties in the full survey, e.g., difficulties in recruiting children aged under 3 years and insufficient collection of blood samples from infants. The operation of the PRINCE project has been modified based on the findings in the pilot study toward improving the validity of the PRINCE project and promoting its openness and transparency.

Increased Tbx1 expression may play a role via TGFß-Smad2/3 signaling pathway in acute kidney injury induced by gentamicin.

T-box 1 (Tbx1) gene is closely involved in embryonic kidney development. To explore the role of Tbx1 in acute kidney injury (AKI) and the underlying mechanism, we detected the expression of Tbx1 and components of transforming growth factor-beta (TGF-ß) signaling pathways including TGF-ß, phosphorylated Smad2/3 (p-Smad2/3) and phosphorylated Smad1/5/8 (p-Smad1/5/8) in kidney tissues derived from a rat model for AKI induced by gentamicin (GM). Apoptosis of renal cells was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), along with the expression of two essential genes involved in apoptosis, caspase-3 and Bcl-2. Correlation between Tbx1 expression and the number of TUNEL-positive cells was analyzed by a Spearman test. Expression of TGF-ß, p-Smad2/3 and p-Smad1/5/8 in Tbx1-knockdown NRK cells was also analyzed by real-time RT-PCR and Western blotting. Markedly increased Tbx1 expression was found in the injured kidney tissues, which has activated the TGFß-Smad2/3 pathway whilst suppressed Smad1/5/8 expression. Conversely, decreased TGF-ß and p-Smad2/3 levels, and elevated p-Smad1/5/8 levels were detected in Tbx1-knockdown NRK cells. More apoptotic cells were detected in the injured kidneys, which has well correlated with the expression of Tbx1. Expression of caspase-3 was markedly increased, while Bcl-2 was decreased in the injured kidney tissues. Above findings suggested that activation of Tbx1 is involved in AKI through the TGFß-Smad2/3 pathway. Tbx1 expression may therefore serve as a marker for AKI, and Tbx1-blocking therapies may provide an option for treating GM-induced nephropathy.