Gram-Scale Preparation of Pd@PANI: A Practical Catalyst Reagent for Copper-Free and Ligand-Free Sonogashira Couplings

Palladium nanoparticles on the polyaniline (Pd@PANI) catalyst are now easily prepared on a gram scale through the oxidative polymerization of aniline in the presence of PdCl₂ by using air as a clean oxidant. The material is found to be very stable and can be stored for more than one year without deactivation. Thus, it may become a commercial reagent in organic synthesis, depending on its application scopes. This article reported the first example of Pd@PANI-catalyzed Sonogashira couplings free of copper and ligands

Design of Free Triblock Polylysine‑<i>b</i>‑Polyleucine‑<i>b</i>‑Polylysine Chains for Gene Delivery

Mixing cationic polymer chains with anionic DNA chains in solution results in the polymer/DNA complexes (also known as polyplexes). We recently confirmed that it is those noncomplexed cationic chains free in the mixture that promote the gene transfection, leading to a hypothesis: free cationic chains adsorbed on various anionic membranes interfere with the signal protein interaction, disrupt the intervesicular fusion, and block the endolysosome pathway so that the plasmid DNA (pDNA) chains have a higher chance to enter the nucleus. Accordingly, we design and synthesize linear cationic–hydrophobic–cationic triblock polylysine (K)-<i>b</i>-polyleucine (L)-<i>b</i>-polylysine (K) as free cationic chains by using natural protamine to condense the pDNA. The hydrophobic middle L-block helps its insertion into the membrane, while the interaction of the two cationic side K-blocks with the signal proteins helps the escape of the polyplexes from the lysosome entrapment. We studied the transfection efficiency of these copolymers with different block lengths. We found the optimal length of blocks K and L that allows the free triblock cationic copolymer chains to effectively enhance the gene transfection process. A combination of copolypeptides and protamine provides a new kind of biocompatible and nontoxic gene vectors made of only nontoxic peptides

Dehydration of Aldoximes Using PhSe(O)OH as the <i>Pre</i>-Catalyst in Air

PhSe­(O)­OH was found to be a good <i>pre</i>-catalyst for aldoxime dehydrations in open air. Compared with the previously reported (PhSe)₂-H₂O₂ system, it is more stable and milder, affording broader application scopes due to a higher functional group tolerance. The control experiments for mechanism study disclosed that air was the key factor for the reaction to maintain enough concentration of PhSeOH, which should be the real catalytic species

Organoselenium-Catalyzed Oxidative CC Bond Cleavage: A Relatively Green Oxidation of Alkenes into Carbonyl Compounds with Hydrogen Peroxide

A relatively green oxidative CC bond cleavage of alkenes was achieved by organoselenium-catalyzed alkene oxidation reaction in ethanol with hydrogen peroxide, affording carbonyl compounds under relatively mild conditions. It is a new reaction style for the organoselenium-catalyzed oxidation of alkenes and largely contributes to the growing field of organoselenium catalysis

The Circular RNA Cdr1as Act as an Oncogene in Hepatocellular Carcinoma through Targeting miR-7 Expression

<div><p>CircRNAs are a class of endogenous RNA that regulates gene expression at the post-transcriptional or transcriptionallevel through interacting with other molecules or microRNAs. Increasing studies have demonstrated that circRNAs play a crucial role in biology processes. CircRNAs are proved as potentialbiomarkers in many diseases including cancers. However, the role of Cdr1as in Hepatocellular carcinoma (HCC) remains to be elucidated. We demonstrated that Cdr1as expression was upregulated in HCC tissues compared with the adjacent non-tumor tissues. In addtion, miR-7 expression was downregulated in HCC tissues compared with the adjacent non-tumor tissues. Moreover, the expression level of miR-7 was inversely correlated with that in HCC tissues. Knockdown of Cdr1as suppressed the HCC cell proliferation and invasion. Overexpression of miR-7 inhibited the HCC cell proliferation and invasion. Overexpression of miR-7 could suppress the direct target gene CCNE1 and PIK3CD expression. Knockdown of Cdr1as suppressed the expression of miR-7 and also inhibited the CCNE1 and PIK3CD expression. Furthermore, knockdown of Cdr1as suppressed the HCC cell proliferation and invasion through targeting miR-7. These data suggested that Cdr1as acted as an oncogene partly through targeting miR-7 in HCC.</p></div

MicroRNA-424 Is Down-Regulated in Hepatocellular Carcinoma and Suppresses Cell Migration and Invasion through c-Myb

<div><p>Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. MicroRNAs (miRNAs) are important regulators of multiple cellular processes, and the aberrant miRNAs expressions have been observed in different types of cancer including HCC. Their pathysiologic role and their relevance to tumorigenesis are still largely unknown. In this study, we demonstrated the down-regulation of miR-424 in HCC cell lines and tissues by quantitative RT-PCR analyses. Overexpression of miR-424 reduced the HCC cell prolifetation, migration, and invasion. Conversely, inhibiton of miR-424 expression significantly accelerated the cell proliferation, migration, and invasion. In addition, we further identified c-Myb as a functional downstream target of miR-424 by directly targeting the 3′UTR of c-Myb. Furthermore, overexpression of c-Myb impaired miR-424-induced inhibition of proliferation and invasion in HCC cells. Our results demonstrated that miR-424 was involved in tumorigenesis of HCC at least in part by suppression of c-Myb.</p></div

Quantifying Components of Soil Respiration and Their Response to Abiotic Factors in Two Typical Subtropical Forest Stands, Southwest China

<div><p>Separating the components of soil respiration and understanding the roles of abiotic factors at a temporal scale among different forest types are critical issues in forest ecosystem carbon cycling. This study quantified the proportions of autotrophic (<i>R</i>_A) and heterotrophic (<i>R</i>_H) in total soil (<i>R</i>_T) respiration using trenching and litter removal. Field studies were conducted in two typical subtropical forest stands (broadleaf and needle leaf mixed forest; bamboo forest) at Jinyun Mountain, near the Three Georges Reservoir in southwest China, during the growing season (Apr.–Sep.) from 2010 to 2012. The effects of air temperature (AT), soil temperature (ST) and soil moisture (SM) at 6cm depth, solar radiation (SR), pH on components of soil respiration were analyzed. Results show that: 1) SR, AT, and ST exhibited a similar temporal trend. The observed abiotic factors showed slight interannual variability for the two forest stands. 2) The contributions of <i>R</i>_H and <i>R</i>_A to <i>R</i>_T for broadleaf and needle leaf mixed forest were 73.25% and 26.75%, respectively, while those for bamboo forest were 89.02% and 10.98%, respectively; soil respiration peaked from June to July. In both stands, CO₂ released from the decomposition of soil organic matter (SOM), the strongest contributor to <i>R</i>_T, accounted for over 63% of <i>R</i>_H. 3) AT and ST were significantly positively correlated with <i>R</i>_T and its components (<i>p</i><0.05), and were major factors affecting soil respiration. 4) Components of soil respiration were significantly different between two forest stands (<i>p</i><0.05), indicating that vegetation types played a role in soil respiration and its components.</p></div

The expression of Cdr1as was upregulated in the HCC tissues and was inverse associated with the expression of miR-7.

<p>(A) The expression of Cdr1as was detected in the HCC tissues and adjacent non-tumor tissues using qRT-PCR. (B) Cdr1as expression was upregulated in the (74%, 26/35) HCC tissues compared with their adjacent non-tumor tissues. (C) The expression of miR-7 was detected in the HCC tissues and adjacent non-tumor tissues using qRT-PCR. (D) miR-7 expression was downregulated in the (66%, 23/35) HCC tissues compared with their adjacent non-tumor tissues. (E) The expression of miR-7 was inversely correlated with the expression of Cdr1as in the HCC tissues.</p

Knockdown of Cdr1as suppressed the HCC cell proliferation and invasion.

<p>(A) The expression of Cdr1as in the HCC cell lines were measured by using qRT-PCR. (B) Knockdown of Cdr1as expression could suppress the Cdr1as expression. (C) Knockdown of Cdr1as expression inhibited the HCC cell line (SMMC-7721) proliferation. (D) The HepG2 cell proliferation was measured by CCK-8 assay. (E) Knockdown of Cdr1as expression inhibited the SMMC-7721 cell invasion. (F) The HepG2 cell invasion was detected by cell invasion assay. *p<0.05, **p<0.01 and ***p<0.001.</p

Knockdown of Cdr1as promoted the miR-7 and its target gene CCNE1 and PIK3CD expression.

<p>(A) The mRNA expression of miR-7 in the SMMC-7721 cell was measured by qRT-PCR. (B) The mRNA expression of CCNE1 was detected by qRT-PCR in the SMMC-7721 cell. (C) The protein expression of CCNE1 was detected by western blot. (D) The mRNA expression of CCNE1 in the SMMC-7721 cell was detected by qRT-PCR. (E) The protein expression of CCNE1 was detected by western blot. (F) The mRNA expression of PIK3CD was detected by qRT-PCR in the SMMC-7721 cell. (G) The protein expression of PIK3CD was measured using western blot. (H) The mRNA expression of PIK3CD was detected by qRT-PCR in the SMMC-7721 cell. (J) The protein expression of PIK3CD was determined by western blot.</p