Photocatalytic Cleavage of ß-O-4 Ether Bonds in Lignin over Ni/TiO2.

It is of great importance to explore the selective hydrogenolysis of ß-O-4 linkages, which account for 45-60% of all linkages in native lignin, to produce valued-added chemicals and fuels from biomass employing UV light as catalyst. TiO2 exhibited satisfactory catalytic performances in various photochemical reactions, due to its versatile advantages involving high catalytic activity, low cost and non-toxicity. In this work, 20 wt.% Ni/TiO2 and oxidant PCC (Pyridinium chlorochromate) were employed to promote the cleavage of ß-O-4 alcohol to obtain high value chemicals under UV irradiation at room temperature. The Ni/TiO2 photocatalyst can be magnetically recovered and efficiently reused in the following four consecutive recycling tests in the cleavage of ß-O-4 ether bond in lignin. Mechanism studies suggested that the oxidation of ß-O-4 alcohol to ß-O-4 ketone by oxidant PCC first occurred during the reaction, and was followed by the photocatalysis of the obtained ß-O-4 ketone to corresponding acetophenone and phenol derivates. Furthermore, the system was tested on a variety of lignin model substrates containing ß-O-4 linkage for the generation of fragmentation products in good to excellent results.

Selective aqueous-phase hydrogenation of furfural to cyclopentanol over Ni-based CNT catalysts.

Cyclopentanol (CPL) was an eco-friendly solvent as well as important platform chemical which could be generated from biomass-derived furfural (FFA). In this paper, a series of Ni, Cu, Mo, Co bimetallic catalysts with different metals loadings supported on carbon nanotubes (CNT) were synthesized by an impregnation method for aqueous-phase hydrogenation of FFA to obtain CPL. Various effects of reaction parameters such as reaction solvent, reaction temperature, reaction time and different loading amounts of Ni over bimetallic Ni-based CNT catalysts were fully investigated. Among the catalysts studied, (15 + 5) wt% NiCu/CNT catalysts showed a high conversion of FFA and 88% selectivity towards CPL in water and 96% selectivity towards acetal in methanol at the mild condition of 160℃, 2 MPa hydrogen and 4 h reaction time. NiCu bimetallic synergistic effect was interpreted through H2-TPR and NH3-TPD measurement and a possible pathway was proposed. The features of the CNT-supported catalysts were investigated via XRD, XPS, TEM, H2-TPR and NH3-TPD. The Ni and bimetallic NiCu catalysts synthesized in this work were inexpensive and simple, which made them a promising candidate for the conversion of biomass-derived FFA to CPL.

3.0 T Magnetic Resonance Functional Imaging Quantitative Parameters for Differential Diagnosis of Benign and Malignant Lesions of the Breast.

Objective: To investigate value of quantitative dynamic contrast-enhanced magnetic resonance imaging (MRI) parameters and apparent diffusion coefficient (ADC) value in differential diagnosis of breast benign and malignant lesions, and their correlation with prognostic factors of breast cancer. Methods: The study collected MRI images and clinical data from 232 female patients suspected of breast cancer. Philips INGENIA 3.0T superconducting magnetic resonance scanner was used for imaging examination. Complete pathological data of patients were collected, and the expression of ER, PR, HER-2, and Ki-67 were further investigated. Results: Kep was higher in malignant breast lesion group than that in benign breast lesion group, and ADC value was lower in the former group than that in the latter group (both p < 0.05). The areas under the receiver operating characteristic curves for Kep, ADC, and extravascular volume fraction (Ve) were 0.904 (95% confidence interval [CI]: 0.863-0.945), 0.813 (95% CI: 0.752-0.875), and 0.774 (95% CI: 0.707-0.841), respectively. Furthermore, according to the maximum Youden index, the specificity of Kep and the sensitivity of ADC were high, which were 97.20% and 96.00%, respectively, with a cutoff value of 0.314 and 0.151, respectively. Kep value in ER-positive expression group was significantly higher than that in ER-negative expression group (p < 0.05). Kep value in PR-positive expression group was significantly higher than that in PR-negative expression group (p < 0.05). There was positive correlation between Kep and expression of Ki-67 (p < 0.05). ADC value was negatively correlated with Ki-67 expression (p < 0.05). Conclusion: Quantitative parameters Kep and ADC of 3.0 T MR functional imaging can be used as reference indexes for differential diagnosis of benign and malignant breast lesions and for biological behavior evaluation, indicating potential clinical value for noninvasive preoperative evaluation of breast cancer.

A radiomic nomogram based on arterial phase of CT for differential diagnosis of ovarian cancer.

PURPOSE: To develop and validate a radiomic nomogram based on arterial phase of CT to discriminate the primary ovarian cancers (POCs) and secondary ovarian cancers (SOCs). METHODS: A total of 110 ovarian cancer patients in our hospital were reviewed from January 2010 to December 2018. Radiomic features based on the arterial phase of CT were extracted by Artificial Intelligence Kit software (A.K. software). The least absolute shrinkage and selection operation regression (LASSO) was employed to select features and construct the radiomics score (Rad-score) for further radiomics signature calculation. Multivariable logistic regression analysis was used to develop the predicting model. The predictive nomogram model was composed of rad-score and clinical data. Nomogram discrimination and calibration were evaluated. RESULTS: Two radiomic features were selected to build the radiomics signature. The radiomics nomogram that incorporated 2 radiomics signature and 2 clinical factors (CA125 and CEA) showed good discrimination in training cohort (AUC 0.854), yielding the sensitivity of 78.8% and specificity of 90.7%, which outperformed the prediction model based on radiomics signature or clinical data alone. A visualized differential nomogram based on the radiomic score, CEA, and CA125 level was established. The calibration curve demonstrated the clinical usefulness of the proposed nomogram. CONCLUSION: The presented nomogram, which incorporated radiomic features of arterial phase of CT with clinical features, could be useful for differentiating the primary and secondary ovarian cancers.