A method for the synthesis of furans bearing indoline skeletons was developed an intramolecular palladium-catalyzed 5- cyclization/etherification cascade of -propargyl arylamines containing a 1,3-dicarbonyl side chain. This method realized the first capture of vinyl carbopalladiums by ketones as -nucleophiles and showed a wide range of substrate tolerability affording trisubstituted furans in various yields. The enantioselective version for this domino process and diverse derivatizations of the reaction products were also studied.
View Article and Find Full Text PDFCancer is an important chronic non-communicable disease that endangers human health and has become the main cause of death of residents around the world in the 21st century. At present, most of the mature treatment methods stay at the level of cell and tissue, which is difficult to fundamentally solve the problem of cancer. Therefore, explaining the pathogenesis of cancer at the molecular level becomes the answer to the key problem of cancer regulation.
View Article and Find Full Text PDFChemical investigation of the culture extract of an endophytic Penicillium citrinum from Dendrobium officinale, afforded nine citrinin derivatives (1-9) and one peptide-polyketide hybrid GKK1032B (10). The structures of these compounds were determined by spectroscopic methods. The absolute configurations of 1 and 2 were determined for the first time by calculation of electronic circular dichroism (ECD) data.
View Article and Find Full Text PDFNanomaterials (Basel)
August 2021
Graphene oxide (GO) is widely used in various fields and has raised concerns regarding its potential environmental fate and effect. However, there are few studies on its influence on coexisting pollutants. In this study, the phototransformation of GO and coexisting sulfamethazine (SMZ) under UV irradiation was investigated, with a focus on the role of reactive oxygen species.
View Article and Find Full Text PDFPurpose: To evaluate the predictive value of routine CT features combined with 3D texture analysis for prediction of BRCA gene mutation status in advanced epithelial ovarian cancer.
Method: Retrospective analysis was performed on patients with masses occupying the pelvic space confirmed by pathology and complete preoperative images in our hospital, including 37 and 58 cases with mutant type and wild type BRCA, respectively (total: 95 cases). The enrolled patients' routine CT features were analyzed by two radiologists.
Biomed Environ Sci
August 2020
Objective: To determine the prevalence and determinants of folic acid (FA) supplementation in Chinese couples planning for pregnancy and in women during early pregnancy.
Methods: This was a cross-sectional study based on the Shanghai PreConception Cohort (SPCC) study. Data on FA supplementation and socio-demographic features were collected using questionnaires.
Sci Total Environ
August 2020
In this study, the photochemistry of ZnO NPs and their effect on phototransformation of coexisting pollutants (sulfamethazine, SMZ) were systematically investigated under UV illumination. SMZ (40 μM) degradation was accelerated by ZnO NPs, as the observed reaction rate constant (k) increased from 0.0809 h to 0.
View Article and Find Full Text PDFMicroplastics have attracted much attention in recent years as they can interact with pollutants in water environment. However, nanoplastics (NPs) with or without the surface functionalization modification have not been thoroughly explored. Here, the sorption behaviors of two fluoroquinolones (FQs), including norfloxacin (NOR) and levofloxacin (LEV) on polystyrene NPs (nano-PS) and carboxyl-functionalized polystyrene NPs (nano-PS-COOH) were investigated.
View Article and Find Full Text PDFMo/ZSM-5-catalyzed methane conversion into aromatic hydrocarbons is an important reaction to produce ethylene and benzene, but the detailed reaction mechanism has not been investigated due to its high complexity. In the present study, density functional theory combined with a periodic model was used to investigate the reaction mechanism of direct methane conversion into aromatic hydrocarbons catalyzed by Mo/ZSM-5. The calculation results show that the active phase for Mo is MoC instead of MoO.
View Article and Find Full Text PDFTwo types of soil covered by biological soil crusts (BSCs) , i.e. moss and algae, and moving sand in the natural vegetation area at the southeast fringe of the Tengger Desert were collected intactly.
View Article and Find Full Text PDFSimilarly to the Wnt protein palmitoyltransferase, porcupine (PPN) is essential to the activation of the Wnt/β-catenin signaling pathway. However, little is known about the role of PPN activity in human gastric cancer, one of the most common causes of cancer-related mortality. Real-time quantitative PCR was used to detect the expression levels of PPN in paired gastric cancer tissues.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
July 2006
We demonstrate numerically that a brief burst consisting of two to six spikes can propagate in a stable manner through a one-dimensional homogeneous feedforward chain of nonbursting neurons with excitatory synaptic connections. Our results are obtained for two kinds of neuronal models: leaky integrate-and-fire neurons and Hodgkin-Huxley neurons with five conductances. Over a range of parameters such as the maximum synaptic conductance, both kinds of chains are found to have multiple attractors of propagating bursts, with each attractor being distinguished by the number of spikes and total duration of the propagating burst.
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