RESUMO
The solvent deasphalting (SDA) process is widely recognized as a significant technology in processing inferior oil. However, de-oiled asphaltene (DOA), which accounts for about 30% of feedstocks, is not well utilized in conventional processing methods to date. Considering its complicated structure and high heteroatom and metal contents, DOA is suitable for preparing amorphous carbon. Herein, we obtained amorphous carbon from inferior de-oiled asphaltene through direct carbonization of a mixture of DOA and Fe2O3 and revealed the mechanism of iron oxide in retarding graphitization to increase the disordered structure content. After the addition of Fe2O3, XRD results showed that the content of amorphous carbon increased from 25.57% to 59.48%, and a higher defect degree could also be observed in Raman spectra, thus resulting in better electrochemical performance in Na-ion half-cells. As a coke core, Fe2O3 could accelerate the polycondensation of asphaltene molecules; meanwhile, oxygen species derived from Fe2O3 could capture excess H free radicals in the initial pyrolysis stage, which inhibited the formation of planar polycyclic aromatic molecules and weakened π-π interactions. Moreover, O atoms could embed into the carbon skeleton by reacting with DOA at higher temperatures, which could further twist and break the intact carbon layer. Both of the factors enhanced the proportion of amorphous carbon. This work not only provides a new understanding of controlling the carbonization process, but it also promotes the development of the SDA process.
RESUMO
The controllable synthesis of spirooxindole-dihydrofurans and spirooxindole-benzazepines was developed through formal [3 + 2] and [5 + 2] cyclization reactions from 2-(2-oxoindolin-3-yl)malononitriles and ortho-aminobenzaldehydes, respectively. A variety of spirooxindole-benzazepines were facilely constructed via a furan ring-open-involved hydride transfer/cyclization process. It is noteworthy that the application of the hydride-transfer-involved [5 + 2] cyclization strategy for construction of spirobenzazepines was unprecedented. In addition, the spiro N- and O-containing heterocycles were highly functionalized by amino, amide, and cyano groups, which were conducive to late-stage functionalization.
RESUMO
Background: Breast cancer (BC) has the highest incidence rate among female malignant tumors. Adjuvant chemotherapy is commonly used to reduce micrometastasis in postoperative patients. However, monitoring the efficacy of chemotherapy in BC is a major challenge in clinical practice. In this study, 1H nuclear magnetic resonance (NMR) metabonomics was performed to explore the serum metabolic characteristics of BC patients before and after adjuvant chemotherapy. Methods: In this study, we collected serum samples from 51 healthy controls and 61 BC patients before and after chemotherapy for 1H NMR metabolomic analysis, and tested the performance of each metabolite and combination segment by the receiver operating characteristic (ROC) curves. Results: Nine metabolites, namely glutamine, citrate, creatine, glycerophosphatidylcholine/phosphatidylcholine, glycine, 1-methylhistidine, lactate, pyruvate and formate had significant changes in BC patients before chemotherapy compared with healthy controls. Lactate, pyruvate, 1-methylhistidine and formate were found to be inversely regulated by chemotherapy. ROC analysis showed that a combination of the four metabolites had good prediction for chemotherapy efficacy with area under the curve of 0.958, sensitivity of 98.36% and specificity of 91.30%. There was no significant correlation between chemotherapy-related metabolites and clinical indicators of cancer patients, indicating that they can be used to evaluate the chemotherapy efficacy of patients with different clinical indicators. Conclusions: Effectively, dynamic and non-invasive metabolic markers for the evaluation of the efficacy of chemotherapy were identified in this study.