A palladium catalyzed reductive aminocarbonylation of benzylic ammonium triflates with nitroarenes for the synthesis of phenylacetamides was developed. Using Pd(acac)2/DPPF catalyst system, a range ...of different substituted phenylacetamides were prepared in moderate to good yields from benzylic ammonium triflates and nitroarenes through Csp3−N bond cleavage. A variety of alkyl, aryl, and halide substituents on both substrates can be used, and many useful functional groups can be tolerated.
A palladium-catalyzed intramolecular Heck/aminocarbonylation of alkene-tethered iodobenzenes with nitro compounds has been developed for the synthesis of carbamoyl-substituted benzoheterocycles. ...Using Mo(CO)6 as a solid CO source, no external reductant or additives were needed in this procedure. Both nitroarenes and nitroalkanes were well tolerated. A range of carbamoyl-substituted dihydrobenzofurans and indolines were prepared in moderate to high yields.
A molybdenum-mediated reductive hydroamination of vinylcyclopropanes with nitroarenes has been developed. A broad range of substituted homoallylamines were prepared in good to excellent yields from ...readily available starting materials. No noble metal catalysts were used in this reaction, and Mo(CO)6 acted as both catalyst and reductant. This protocol provides an effective method for the selective synthesis of substituted homoallylamines from easily available nitroarenes.
AIM: To evaluate the effect of antisense oligonucleotide targeting midkine (MK-AS) on angiogenesis in chick chorioallantoic membrane (CAM) and in situ human hepatocellular carcinoma (HCC).
METHODS: ...An in situ human hepatocellular carcinoma (HCC) model and CAM assay were used in this experiment. The effect of MK-AS on angiogenesis was evaluated by cell proliferation assay and hematoxylineosin (HE) staining.
RESULTS: MK-AS significantly inhibited human umbilical vein endothelial cells (HUVEC) and in situ human HCC growth. At the same time, MK-AS suppressed the angiogenesis both in human hepatocellular carcinoma cell line (HEPG2)-induced CAM and in situ human HCC tissues.
CONCLUSION: MK-AS is an effective antiangiogenesis agent in vivo.
AIM: To evaluate the effect of combined antisense oligonucleotides targeting midkine (MK-AS) and chemotherapeutic drugs cisplatin(DDP), 5-fluorouracil (5-FU) and adriamycin (ADM) on inhibition of ...HepG2 cell proliferation, and to analyze the efficacy of MK-AS used in combined ADM in in situ human hepatocellular carcinoma (HCC) model. METHODS: HepG2 cells were treated with MK-AS and/or chemotherapeutic drugs mediated by Lipofectin, and cell growth activity was determined by MTS assay. An in situ HCC model was used in this experiment. MK- AS, ADM and MK-AS + ADM were given intravenously for 20 d, respectively. The animal body weight and their tumor weight were measured to assess the effect of the combined therapy in vivo. RESULTS: Combined treatment with MK-AS reduced the IC50 of DDP, 5-FU and ADM in HepG2 cells. MK-AS significantly increased the inhibition rate of DDP, 5-FU and ADM. Additionally, synergism (Q 1.15) occurred at a lower concentration of ADM, 5-FU and DDP with combined MK-AS. Combined treatment with MK-AS and ADM resulted in the more growth inhibition on in situ human HCC model compared with treatment with chemotherapeutic drugs alone. CONCLUSION: MK-AS increases the chemosensitivity in HepG2 cells and in situ human HCC model, and the combination of MK-AS and ADM has a much better in vitro and in vivo synergism.
In the process of metro station construction, the partition wall is usually used to prevent the displacement of the soil behind the wall to ensure the construction platform. This research aims to ...analyze the response of partition wall to keep the safety of the structure. The time-horizontal displacement and cracks of the partition wall are measured during the process of metro station construction. The finite element software FLAC 3D is used to simulate the response of partition wall, and the reasons of partition wall cracking and displacement are analyzed by finite element simulation and measurement data. The stiffness and self-stability of the partition wall in the station is powerful, the stress concentration appeared on the central area and caused cracks of the partition wall. Reducing the pressure exerted on the partition wall and shifting partial pressure exerted on the partition wall by the construction of the medium plate can solve the tress concentration problem. Through the data analysis of the strengthened partition wall, the reinforcement effect is good, ensuring the safety of the subsequent construction. The causes of partition wall cracking are found during process of metro station construction, and the solution proposed in this paper is effective. Engineers can refer to this paper to analyze the response of partition wall in the construction of similar structures, which can ensure construction safety and reduce construction cost.
The diurnal and seasonal variations of soil respiration (SR) were studied at a subtropical mangrove wetland in the Jiulong River Estuary from May 2010 to April 2011. SR rates were measured ...continuously from 08:00 to 06:00 local time (24-h time system) on July 8-9 and October 3-4, 2010; and January 15-16 and April 11-12, 2011. Similar patterns in the diurnal variation of SR were observed on October 2-3 and April 11-12, with the maximum values at 14:00 and the minimum at 00:00. However, the diurnal dynamics of SR on July 8-9, 2010 and January 15-16, 2011 showed different patterns, with the maximum values at 08:00-10:00 on above sampling dates and the minimum at 22:00 on July 8 and at 04:00 on January 16. The daily mean values of SR approximated to the values measured at 08:00. SR fluctuated with distinct seasonal patterns. The seasonal variation was characterized by a mono-peak pattern, with the highest rate (6.18 ~mol CO2 m-2 s-1) in July and the lowest rate (0.36 ~tmol CO2 m-2 s-1) in December. The results showed that the variation of SR in mangrove wetland was mainly controlled by soil temperature, and there was no significant correlation between SR and soil water content. It also implied that the model of SR in mangrove wetland should not only consider the effect of soil temperature, but also incorporate other factors, such as water level, precipitation, microbial activity and photosynthesis, which also could affect SR.
Overexpression of midkine (MK) has been observed in many malignancies. This aim of this study is to screen for suitable antisense oligonucleotides (ASODN) targeting MK in hepatocellular carcinoma ...(HCC) cells and evaluate its antitumor activity.
Ten ASODN targeting MK were designed and synthesized. After transfection with ASODN, cell proliferation was analyzed with MTS3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assay. In addition, MK mRNA, protein levels, as well as apoptosis and caspase-3 activity were also examined in HepG2 cells. Cell proliferation was then analyzed after treatment with both ASODN and chemotherapeutic drugs.
In this experiment, the ASODN5 among the 10 ASODN showed higher inhibitory activity against proliferation of hepatocellular carcinoma cells in a dose-dependent manner. In HepG2 cells, ASODN5 could significantly reduce the MK mRNA level and protein content. After transfection with ASODN5 for 48 h, accompanied with a decline of survivin and Bcl-2 protein content, a remarkable increase of apoptosis and caspase-3 activity was observed in HepG2 cells. Furthermore, ASODN5 transfer can significantly increase chemosensitivity in HepG2 cells.
Antisense oligonucleotides targeting MK shows therapeutic effects on HCC; ASODN5 has the possibility to be developed as an effective antitumor agent.
Dear editor, In recent years, privacy concerns grow rapidly since an eavesdropper can probably overhear the wireless communication. However, it becomes much more challenging for the traditional key- ...based encryption to distribute and manage the se- cret key in large-scale wireless networks.