Enzyme biofuel cells (EBFCs) can convert chemical or biochemical energy in fuel into electrical energy, and therefore have received widespread attention. EBFCs have advantages that traditional fuel cells cannot match, such as a wide range of fuel sources, environmental friendliness, and mild reaction conditions. At present, research on EBFCs mainly focuses on two aspects: one is the use of nanomaterials with excellent properties to construct high-performance EBFCs, and the other is self-powered sensors based on EBFCs.
View Article and Find Full Text PDFUnderstanding the hydrogen atom abstraction (HAA) reactions of -heterocyclic carbene (NHC)-boranes is essential for extending the practical applications of boron chemistry. In this study, density functional theory (DFT) computations were performed for the HAA reactions of a series of NHC-boranes attacked by CHCN, Me and Et radicals. Using the computed data, we investigated the correlations of the activation and free energy barriers with their components, including the intrinsic barrier, the thermal contribution of the thermodynamic reaction energy to the kinetic barriers, the activation Gibbs free energy correction and the activation zero-point vibrational energy correction.
View Article and Find Full Text PDFIn this study, we employed a quantum-mechanical computational method to investigate the hydrogen-atom abstraction reactions of two nitrogen heterocyclic carbene boranes (NHC-boranes), NHC-BH and NHC-BHCN, by a series of carbon-centered radicals bearing various substituents. We explored the degree of correlation of the activation and free energy barriers to their components. Furthermore, we also investigated the effects of the radical and substituent sizes, nucleophilicity/electrophilicity indices, and the spin density distribution of the radical reactants on the three fundamental barriers and the thermal contribution of the reaction energy to the kinetic barrier.
View Article and Find Full Text PDFIn this study, we performed a theoretical investigation of the intramolecular cyclization of bicyclic 2-allyl-2-methyl-2,3-dihydro-1 H-inden-1-iminyl radical 1 along with several iminyl model compounds. The results were used to comparatively evaluate the reaction mechanism suggested previously, in which the neophyl-like rearrangement was deemed to play a decisive role. The present computation and numerical simulation identify the experimentally observed endo product in the high-temperature cyclization of 1.
View Article and Find Full Text PDFThe aim of this study was to explore the expression of heparanase (HPA) in metastatic lymph nodes (LNs) of cervical cancer and to evaluate HPA as a marker of micro-metastasis of LNs. Immunohistochemistry was performed to detect the expression of HPA in 53 cases with metastasis of LNs (group A) and 49 cases without (group B). Scoring was determined based on the intensity of immunostaining and the size of the staining area.
View Article and Find Full Text PDFHeparanase (HPA) is an enzyme that plays an important role in cancer metastasis and angiogenesis and is a potential target for molecular treatment of tumors. We previously found that abnormally high HPA expression in cervical cancer tissues is associated with poor survival and increased lymph node metastasis. The present study was conducted to assess the utility of inhibiting HPA enzyme activity in cervical cancer treatment.
View Article and Find Full Text PDFZhonghua Fu Chan Ke Za Zhi
July 2015
Objective: To provide the theoretical supportting for targeted heparanase (HPA) inhibition of cervical cancer through observing the anti-proliferative effect of the HPA inhibitor on HeLa cell line of cervical cancer.
Methods: The two series of 13 kinds of novel HPA inhibitors were synthesized and optimized. Heparan degrading enzyme assay kit was used to test the effect of the inhibitors on the inhibition of HPA enzyme activity.
Background: Aberrant expression of heparanase (Hpa) is associated with apoor prognosis in ovarian and cervical cancer patients. Inhibitors of Hpa can prevent the growth and metastasis of malignant tumor cells, and suramin may be such a compound that has strong anti-proliferative effects on several kinds of cancer cells. We have therefore tested whether the growth inhibiting effect of suramin on ovarian and cervical cancer cells is due to downregulation of Hpa expression.
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