Visible-Light-Driven Decarboxylative Coupling of 2H-Indazoles with α-Keto Acids without Photocatalysts and Oxidants.

An efficient synthesis of functionalized 3-acyl-2H-indazoles via visible-light-induced self-catalyzed energy transfer was developed. This method utilized a self-catalyzed energy transfer process between 2H-indazoles and α-keto acids, offering advantages like absence of photosensitizers, metal catalysts, and strong oxidants, broad substrate compatibility, and operational simplicity under mild conditions.

Visible-light-mediated aerobic Ritter-type C-H amination of diarylmethanes using DDQ/tert-butyl nitrite.

A metal-free photocatalytic Ritter-type C-H amination of unactivated sp3 carbons using molecular oxygen as a terminal oxidant has been developed. By employing a co-catalytic system of 3-dichloro-4,5-dicyano-1,4-benzoquinone (DDQ) and tert-butyl nitrite (TBN), this novel strategy provides a low cost, sustainable and scalable way to synthesise a broad range of secondary amides in moderate to excellent yields under mild conditions.

Electrochemical Performance of ABNO for Oxidation of Secondary Alcohols in Acetonitrile Solution.

The ketones was successfully prepared from secondary alcohols using 9-azabicyclo[3.3.1]nonane-N-oxyl (ABNO) as the catalyst and 2,6-lutidine as the base in acetonitrile solution. The electrochemical activity of ABNO for oxidation of 1-phenylethanol was investigated by cyclic voltammetry, in situ Fourier transform infrared spectroscopy (FTIR) and constant current electrolysis experiments. The resulting cyclic voltammetry indicated that ABNO exhibited much higher electrochemical activity when compared with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) under the similar conditions. A reasonable reaction mechanism of the electrocatalytic oxidation of 1-phenylethanol to acetophenone was proposed. In addition, a series of secondary alcohols could be converted to the corresponding ketones at room temperature in 80⁻95% isolated yields.

[Studies on corrosion property of the anodic coating on the Mg alloy by micro-FTIR mapping].

Micro-FTIR mapping technology was used to monitor the amount and distribution of Mg(OH)2 on the anodic coating of magnesium alloy which was immersed in the 7.3 Wt% Na2SO4 solution for different time. In the solution, part of the MgO on the surface of the Mg alloy could gradually transform into Mg(OH)2 which could be detached from the Mg alloy surface and dis- solved into the solution. With immersion time of 2 h in 7.3 Wt% Na2SO4 solution 2h, FTIR mapping results showed that FTIR absorption signal of Mg(OH)2 was strongest and Mg(OH)2 was most on the surface of the anodic coating. After 4 hours, the content of Mg(OH)2 began to decrease, and the Mg alloy was etched gradually. The FTIR mapping results of another component Al2O3 with immersion time were almost similar to those of Mg(OH)2. The impedance of the oxide film was also analyzed using electrochemical impedance spectroscopy. It showed that the impedance changed with the immersion time and conformed to the corrosion law of the oxide coating. This research has a good guidance and application value for characterization of the anodic coating on magnesium alloy.

Affinity-based alleviation of dissolved organic matter (DOM) on tetracycline toxicity to photosynthesis of green algae Chlorella vulgaris: roles of hydrophilic and hydrophobic DOM.

The environmental fate and toxic effects of antibiotics such as tetracycline (TC) could be influenced by the ubiquitous dissolved organic matter (DOM). However, DOM from different origins has different hydrophilic and hydrophobic properties. It is still unknown the effects of hydrophilic and hydrophobic DOM on the toxic effect of TC. In this study, DOM with hydrophilicity and hydrophobicity was separated and used to investigate their roles in affecting TC toxicity to the photosynthesis of green algae Chlorella vulgaris. Results showed that 10 mg L-1 TC inhibited the efficiency of photosystem II (PSII) of C. vulgaris using light by hindering electron transfer from QA- to QB/QB-, and the O2 release rate of C. vulgaris decreased by a third after 12-h treatment of 10 mg L-1 TC, while both hydrophilic and hydrophobic DOM (20 mg L-1 TOC) alleviated TC toxicity to the photosynthesis of C. vulgaris. In the presence of hydrophilic or hydrophobic DOM, stable complex of TC-hydrophilic DOM or TC-hydrophobic DOM was formed immediately, due to the good affinity of both DOM for TC. Fourier transform infrared spectroscopy result showed that both hydrophilic and hydrophobic DOM could reduce C=O in TC to C-O, and isothermal titration calorimetry result suggested that reactions of both DOM with TC were exothermic (△H < 0) and spontaneous (△G < 0). Thereinto, the reaction constant (Ka) of TC reacting with hydrophobic DOM (Ka=9.70) was higher than that with hydrophilic DOM (Ka=8.93), indicating hydrophobic DOM with more chemical binding sites and accessible fractions for TC. The present study suggests that DOM, especially the hydrophobic DOM, is an important consideration in the environmental impact assessment of antibiotics.

The role of interaction between autophagy and apoptosis in tumorigenesis (Review).

Autophagy is a highly conserved process that maintains cellular homeostasis during evolution. Autophagy can occur in the form of macroautophagy, microautophagy or molecular chaperone autophagy, among which macroautophagy is the most common. Apoptosis exists in all kinds of cell organisms, and is a kind of programmed cell death which is regulated by pro­apoptotic factors and anti­apoptotic signals. The main biological feature of apoptosis is the activation of caspase. Apoptosis is induced by a variety of cell signals, such as endoplasmic reticulum stress, induction of toxic substances, stimulation of pathogenic microorganisms and DNA damage. Inextricable links are found between autophagy and apoptosis. Studies have found that numerous of the autophagy molecules and autophagy signaling pathways involved in the process of autophagy are related to apoptosis. In addition to regulating autophagy, the autophagy signaling pathway also regulates apoptosis. The interaction between the two can achieve a dynamic balance to certain extent, which maintains the basic physiological functions of cells and reduces the damage to the body under stress. Disease occurs when the balance between autophagy and apoptosis is disrupted. Tumors form due to the ability of cells to avoid apoptosis. Autophagy is closely related to apoptosis, there must be a close connection between the three. In the present review, the mechanism between autophagy and apoptosis and the impact of their interaction on tumorigenesis shall be discussed.

Morpholinium 4-amino-5-meth-oxy-2-methyl-benzensulfonate.

In the crystal structure of the title compound, C(4)H(10)NO(+)·C(8)H(10)NO(4)S(-), the components are linked by N-H⋯O hydrogen bonds, forming a centrosymmetric 2:2 aggregate. The aggregates are further connected by N-H⋯O hydrogen bonds between the anions, forming a double-tape structure along the a axis.

SBA-15 Supported 1-Methyl-2-azaadamanane N-Oxyl (1-Me-AZADO) as Recyclable Catalyst for Oxidation of Alcohol.

Herein, we designed and synthesized an SBA-15 supported 1-methyl-2-azaadamanane N-oxyl (1-Me-AZADO) and investigated its catalytic performance for selective oxidation of alcohols under Anelli's conditions. The first example of immobilization of 1-Me-AZADO was very important to advance the oxgenation effectively because this supported N-oxyl has excellent catalytic activity for oxidation of alcohols to carbonyl compounds, and more importantly, it can be conveniently recovered and reused at least 6 times without significant effect on its catalytic efficiency.

Phytotoxicity of chiral herbicide bromacil: Enantioselectivity of photosynthesis in Arabidopsis thaliana.

With the wide application of chiral herbicides and the frequent detection of photosystem II (PSII) herbicides, it is of great importance to assess the direct effects of PSII herbicides on photosynthesis in an enantiomeric level. In the present study, the enantioselective phytotoxicity of bromacil (BRO), typical photosynthesis inhibition herbicide, on Arabidopsis thaliana was investigated. The results showed that S-BRO exhibited a greater inhibition of electron transmission in photosystem I (PSI) of A. thaliana than R-BRO by inhibiting the transcription of fnr 1. S-BRO also changed the chlorophyll fluorescence parameters Y (II), Y (NO), and Y (NPQ) to a greater extent than R-Bro. Transcription of genes psbO2, Lhcb3 and Lhcb6 was down-regulated in an enantioselective rhythm and S-BRO caused more serious influence, indicating that S-BRO did worse damage to the photosystem II (PSII) of A. thaliana than R-BRO. This study suggested that S-BRO disturbed the photosynthesis of plants to a larger extent than R-BRO and provided a new sight to evaluate the phytotoxicity of chiral herbicides.

Carbon nanotubes as a secondary support of a catalyst layer in a gas diffusion electrode for metal air batteries.

In this paper, we report the use of binary carbon supports (carbon nanotubes (CNTs) and active carbon) as a catalyst layer for fabricating gas diffusion electrodes. The electrocatalytic properties for the oxygen reduction reaction (ORR) were evaluated by polarization curves and electrochemical impedance spectroscopy (EIS) in an alkaline electrolyte. The binary-support electrode exhibits better performance than the single-support electrode, and the best performance is obtained when the mass ratio of carbon nanotubes and active carbon is 50:50. The results from the electrode kinetic parameters indicate that the introduction of carbon nanotubes as a secondary support provides high accessible surface area, good electronic conductivity, and fast ORR kinetics. Furthermore, the effect of CNT support on the electrocatalytic properties of Pt nanoparticles for binary-support electrodes was also investigated by different loading-reduction methods. The electrocatalytic activity of the binary-support electrodes is improved dramatically by Pt loading on CNT carbon support, even at very low Pt loading. Additionally, the EIS analysis results indicate that the process of ORR may be controlled by diffusion of oxygen in the electrode thin film for binary-support electrodes with or without Pt catalyst.

[Application of the fiber-reinforced resin in transitional denture after implantation].

PURPOSE: To evaluate the clinical effect of transitional restoration by the fiber-reinforced resin bonded bridge in the anterior zone after implantation. METHODS: Twenty-three cases with missing upper/lower central incisor, lateral incisor or canine were collected and randomly divided into the experimental group and the control group. One week after implant operation, the patients in the experimental group were repaired with the fiber-reinforced resin bonded bridge; while 2 weeks after implant operation, the patients in the control group were repaired with the removable partial denture. Then, the clinical effect was evaluated. The data was analyzed with SPSS18.0 software package for X(2) test. RESULTS: Patients in the experimental group were more satisfied with pronunciation than in the control group. The incidence of adverse reactions in the experimental group was significantly lower than that in the control group(P<0.05). Patients in both groups were quite satisfied with the esthetic effect(P>0.05). CONCLUSIONS: There are comfortable feeling and satisfactory aesthetic result with the fiber-reinforced resin bonded bridge. It didn't affect wound healing and could meet the requirement of transitional repair after implantation.

Highly efficient detoxification of Cr(VI) by chitosan-Fe(III) complex: process and mechanism studies.

Metal-biopolymer complexes has recently gained significant attention as an effective adsorbent used for the removal of Cr(VI) from water. Unfortunately, despite increasing research efforts in the field of removal efficiency, whether this kind of complex can reduce Cr(VI) to less-toxic Cr(III) and what are the mechanisms of detoxification processes are still unknown. In this study, despite the highly adsorption efficiency (maximum adsorption capacity of 173.1 mg/g in 10 min), the significant improvement of Cr(VI) reduction by chitosan-Fe(III) complex compared with normal crosslinked chitoan has been demonstrated. In addition, the structure of chitosan-Fe(III) complex and its functional groups concerned with Cr(VI) detoxification have been characterized by the powerful spectroscopic techniques X-ray absorption fine structure (XAFS) and X-ray photoelectron spectroscopy (XPS). The XPS spectra indicated that the primary alcoholic function on C-6 served as an electron donor during Cr(VI) reduction and was oxidized to a carbonyl group. The X-ray adsorption near edge spectra (XANES) of the Cr(VI)-treated chitosan-Fe(III) complex revealed the similar geometrical arrangement of Cr species as that in Cr(III)-bound chitosan-Fe(III). Overall, a possible process and mechanism for highly efficient detoxification of Cr(VI) by chitosan-Fe(III) complex has been elucidate.

Hydrogen bonding and pi-pi interactions in a laminar structure: benzene-1,3-dicarboxylic acid-4-methylpyridine (1/2).

The title complex, C8H6O4.2C6H7N, consists of two crystallographically independent 1:2 clusters of benzene-1,3-dicarboxylic acid and 4-methylpyridine. Each cluster, the components of which are linked by O-H...N hydrogen bonds, is almost planar by alignment of C-H...O hydrogen bonds. Herring-bone ribbons of clusters are formed by other C-H...O hydrogen bonds, and these ribbons are further packed to form a laminar structure by pi-pi interactions.

Bis(2-chloro-5-methylpyridine-kappaN)bis(nitrato-kappa(2)O,O')copper(II).

In the molecule of the title compound, [Cu(NO(3))(2)(C(6)H(6)ClN)(2)], the Cu atom lies on an inversion centre and is six-coordinated by two pyridine N atoms and four nitrate O atoms in trans positions. The nitrate acts as an unsymmetrical bidentate ligand. The coordination geometry is octahedral, with the Cu-N and the two Cu-O distances being 1.9939 (16), 2.0246 (16) and 2.4866 (19) A, respectively. There are five types of C-H.O hydrogen bonds. Two of these generate two-dimensional molecular networks in the direction of the a axis, and the others connect adjacent molecular networks.

Diethyl 3,8-dimethyl-4,7-diazadeca-2,8-dienedioate.

The title compound, C14H24N2O4, consists of two symmetric moieties related through a twofold axis. The whole molecule has a cis conformation. Both the ionic enol form and the non-ionic keto form make comparable contributions to the structure. In the crystal structure, infinite supramolecular chains are formed through N-H...O hydrogen bonds.