Engineering surface framework TiO6 single sites for unprecedented deep oxidative desulfurization

Catalytic oxidative desulfurization (ODS) using titanium silicate catalysts has emerged as an efficient technique for the complete removal of organosulfur compounds from automotive fuels. However, the precise control of highly accessible and stable-framework Ti active sites remains highly challenging. Here we reveal for the first time by using density functional theory calculations that framework hexa-coordinated Ti (TiO6) species of mesoporous titanium silicates are the most active sites for ODS and lead to a lower-energy pathway of ODS. A novel method to achieve highly accessible and homogeneously distributed framework TiO6 active single sites at the mesoporous surface has been developed. Such surface framework TiO6 species exhibit an exceptional ODS performance. A removal of 920 ppm of benzothiophene is achieved at 60°C in 60 min, which is 1.67 times that of the best catalyst reported so far. For bulky molecules such as 4,6-dimethyldibenzothiophene (DMDBT), it takes only 3 min to remove 500 ppm of DMDBT at 60°C with our catalyst, which is five times faster than that with the current best catalyst. Such a catalyst can be easily upscaled and could be used for concrete industrial application in the ODS of bulky organosulfur compounds with minimized energy consumption and high reaction efficiency.

Synergistic effect of K and Zn on Fe-based catalysts for efficient CO2 hydrogenation

Excessive emission of CO2 into the atmosphere has severely impacted the global ecological environment. Converting CO2 into valuable chemicals and fuels is of great significance for sustainable development. However, low activity and undesirable selectivity often result from the inherent inertness of CO2. Herein, K- or/and Zn-modified Fe-based catalysts were prepared by an incipient-wetness impregnation method for CO2 hydrogenation via a cascade reaction. The results indicate that K species exist as K2O while Zn species exist as ZnFe2O4. In the CO2 hydrogenation pathway, K2O facilitates the adsorption of CO2 and restrains the adsorption of H2, accelerating the transformation of CO2 into C2-C4 olefins rather than paraffins while Zn species promote the dispersion of Fe species, leading to improved activity. Synergistically, a K- and Zn-modified Fe-based catalyst (2Zn-10K-Fe/Al) shows excellent catalytic CO2 hydrogenation activity, achieving a CO2 conversion of 77% which is 1.8 times that (42%) of the unmodified Fe-based catalyst (Fe/Al). Our catalyst also shows a significantly promoted selectivity to C2-C4 olefins of 17% in comparison with the Fe/Al catalyst (0%). It is envisioned that such a binary effect of elements might contribute to the low-cost and industrial production of Fe-based catalysts for selective CO2 conversion.

Intraparticle ripening to create hierarchically porous Ti-MOF single crystals for deep oxidative desulfurization

The catalytic oxidative desulfurization (ODS) technique is able to remove sulfur compounds from fuels, conducive to achieving deep desulfurization for the good of the ecological environment. Ti-based metal-organic frameworks (Ti-MOFs) possessing good affinity to organic reactants and considerable numbers of Ti active sites are promising catalysts for ODS. However, current Ti-MOFs suffer from severe diffusion limitations caused by the size mismatch between sole micropores and bulky sulfur compounds, leading to poor ODS performance. Here, a facile method of intraparticle ripening without any additive is developed to obtain hierarchically meso-microporous Ti-MIL-125 single crystals (Meso-Ti-MIL-125) for the first time. Such Meso-Ti-MIL-125 shows a BET surface area of 1401 m2 g-1 and a mesoporous volume that is 1.7 times as high as that of the conventional Ti-MIL-125. Our novel Meso-Ti-MIL-125 exhibits excellent catalytic performance in the ODS of a series of bulky thiophenic sulfur compounds, completely removing benzothiophene (BT), dibenzothiophene (DBT), and 4,6-dimethyldibenzothiophene (DMDBT) from model fuels, which is, respectively, 2.4 times, 1.5 times, and 6.7 times higher than the removal achieved with conventional Ti-MIL-125. Such a facile synthetic strategy is envisioned to be applied in many kinds of crystalline materials, such as zeolites, for industrial production.

Ti-MOF single-crystals featuring an intracrystal macro-microporous hierarchy for catalytic oxidative desulfurization

For the first time, we demonstrate a Ti-MOF (Ti-metal organic framework) single-crystal featuring an intracrystal macro-microporous hierarchy (Hier-NTU-9) by a vapor-assisted polymer-templated method. This Hier-NTU-9 possesses macropores (100-1000 nm) derived from polymer templates and enhanced transport ability of bulky molecules, exhibiting almost double the desulfurization activity compared to the conventional NTU-9.

[Mechanism of total flavonoid extract from Dracocephalum moldavica on bleomycin-induced pulmonary fibrosis in mice based on pyroptosis pathway]

This study investigated the mechanism of total flavonoid extract from Dracocephalum moldavica(TFDM) in mice with bleomycin(BLM)-induced pulmonary fibrosis(PF) and explored its mechanism against the pyroptosis pathway. A mouse model of PF was established by intratracheal infusion of bleomycin(4 mg·kg~(-1)), and the normal group was treated with the same dose of saline under the same conditions. After the second day of modeling, the distilled water was given to the normal and model groups by gavage, and the corresponding drug were given to the TFDM and the dexamethasone groups for 28 consecutive days. After 28 days, lung tissues of mice with PF were taken to determine the content of hydroxyproline(HYP). The degree of lung inflammation and fibrosis was observed by hematoxylin-eosin(HE) and Masson stainings, and the content of interleukin-18(IL-18) and interleukin-1β(IL-1β) in the serum of mice with PF were measured by enzyme-linked immunosorbent assay(ELISA). Western blot was used to determine the expression levels of proteins in the lung tissues of mice with PF. HE staining showed that the BLM group had abnormal lung tissue structures and showed more inflammatory cell infiltration. Masson staining showed plenty of collagenous fibrotic tissues that were stained blue in the lung tissues. As compared with the normal group, the content of HYP and levels of IL-18 and IL-1β in the serum of rats in the BLM group were up-regulated(P<0.01). The protein expressions of type Ⅰ collagen(Col-1), fibronectin 1(FN1), α-smooth muscle actin(α-SMA), cysteinyl aspartate specific proteinase-1(caspase-1), gasdermin D(GSDMD), NOD-like receptor thermal protein domain associated protein 3(NLRP3), p62, and apoptosis-associated speck-like protein containing a CARD(ASC) in the lung tissues of mice with PF in the BLM group were increased(P<0.01), whereas the protein expressions of autophagy-related 5(ATG5) and Beclin1 were decreased(P<0.01). Compared with the BLM group, the TFDM groups and dexamethasone group showed normal lung tissue structures and reduced inflammatory cell infiltration. Less collagenous fibrous tissues in blue color were seen and the fibrosis in the lung tissue was alleviated in the TFDM groups and dexamethasone group, with the down-regulation of the content of HYP and the levels of IL-18 and IL-1β(P<0.05, P<0.01). In the TFDM groups and dexamethasone group, the protein expression levels of Col-1, FN1, α-SMA, caspase-1, GSDMD, NLRP3, p62, and ASC were decreased(P<0.01), and the protein expressions of ATG5 and Beclin1 were increased(P<0.01) in the lung tissues of mice with PF. From the above results, it is known that TFDM down-regulates the levels of inflammatory factors and related proteins, and effectively mitigates the process of BLM-induced PF by regulating the pyroptosis pathways and potentially affecting the autophagy.

Boosting molecular diffusion following the generalized Murray's Law by constructing hierarchical zeolites for maximized catalytic activity

Diffusion is an extremely critical step in zeolite catalysis that determines the catalytic performance, in particular for the conversion of bulky molecules. Introducing interconnected mesopores and macropores into a single microporous zeolite with the rationalized pore size at each level is an effective strategy to suppress the diffusion limitations, but remains highly challenging due to the lack of rational design principles. Herein, we demonstrate the first example of boosting molecular diffusion by constructing hierarchical Murray zeolites with a highly ordered and fully interconnected macro-meso-microporous structure on the basis of the generalized Murray's Law. Such a hierarchical Murray zeolite with a refined quantitative relationship between the pore size at each length scale exhibited 9 and 5 times higher effective diffusion rates, leading to 2.5 and 1.5 times higher catalytic performance in the bulky 1,3,5-triisopropylbenzene cracking reaction than those of microporous ZSM-5 and ZSM-5 nanocrystals, respectively. The concept of hierarchical Murray zeolites with optimized structural features and their design principles could be applied to other catalytic reactions for maximized performance.

[Long-term outcomes and failure patterns of definitive radiotherapy for cervical esophageal carcinoma]

Objective: To evaluate the long-term outcomes, failure patterns and prognostic factors of definitive radiotherapy in patients with cervical esophageal carcinoma (CEC). Methods: We retrospectively reviewed the clinical data of 148 CEC patients who treated with definitive radiotherapy in Cancer Hospital of Chinese Academy of Medical Sciences from January 2001 to December 2017. The median radiation dose was 66 Gy (59.4-70 Gy) and 33.1% of patients received concurrent chemotherapy. The Kaplan-Meier method was used to calculate survival rates. The log rank test was used for survival comparison and univariate prognostic analysis. The Cox model was used for multivariate prognostic analysis. Results: The median follow-up time was 102.6 months. The median survival time, 2- and 5-year overall survival (OS) were 22.7 months, 49.9% and 28.3%. The median, 2- and 5-year progression-free survival were 12.6 months, 35.8% and 25.8%. The 2- and 5-year locoregional recurrence-free survival were 59.1% and 50.8%. The 2- and 5-year distant metastases-free survival were 74.6% and 65.9%. Multivariate analysis showed that EQD(2)>66 Gy was the only independent prognostic indicator for OS (P=0.040). The median survival time and 5-year OS rate significantly improved in patients who received EQD(2)>66 Gy than those who received≤66 Gy (31.2 months vs. 19.2 months, 40.1% vs. 19.1%, P=0.027). A total of 87 patients (58.8%) developed tumor progression. There were 50 (33.8%), 23 (15.5%) and 39 (26.4%) patients developed local, regional recurrence and distant metastases, respectively. Eleven patients (7.4%) underwent salvage surgery, and the laryngeal preservation rate for entire group was 93.9%. Conclusions: Definitive radiotherapy is an effective treatment for cervical esophageal carcinoma with the advantage of larynx preservation. Local recurrence is the major failure pattern. EQD(2)>66 Gy is associated with the improved overall survival.

[Study on safety of adjuvant radiotherapy concurrent with weekly chemotherapy for stage ⅡB-ⅣA esophageal carcinoma after radical resection]

Objective: To evaluate the tolerability and short-term efficacy of chemo-radiotherapy in 125 patients with stage ⅡB-ⅣA esophageal carcinoma after radical resection. Methods: We retrospectively evaluated the rate of completion, toxicity and survival of patients undergoing adjuvant concurrent chemo-radiotherapy after radical resection of esophageal carcinoma from January 2004 to December 2014 in our institution. The survival rate was determined by the Kaplan-Meier method and analyzed using the log-rank test. Multivariate prognostic analysis was performed using the Cox proportional hazard model. Results: 122 patients received more than 50 Gy dose (97.6%). A total of 52 patients received more than 5 weeks chemo-radiotherapy (41.6%), while 73 patients underwent only 1-4 weeks (58.4%). The median following up was 48.4 months. 8 patients lost follow up (6.4%). The 1-year and 3-year overall survival rate were 91.6% and 57.0%, respectively, with a median survival time of 64.4 months. The 1-year and 3-year disease free survival rate were 73.2% and 54.3%, respectively, with a median disease free survival time of 59.1 months. The most common acute complications associated with chemo-radiotherapy were myelosuppression, radiation esophagitis and radiation dermatitis, the majority of which were Grade 1-2. Of the 125 patients, there were 59 cases of recurrence, including 23 cases with local regional recurrence, 26 cases with hematogenous metastasis, and 8 cases with mixed recurrence. Univariate analysis showed that the numbers of concurrent chemotherapy was associated with the overall survival (P=0.006). But receiving more than 5 weeks was not the prognostic factor compared to 1 to 4 weeks chemotherapy (P=0.231). Multivariate analysis showed that only the numbers of concurrent chemotherapy was an independent prognostic factor (P=0.010). Conclusions: Postoperative radiotherapy concurrent with weekly chemotherapy could improve the overall survival and decrease the recurrence for stage ⅡB-ⅣA esophageal carcinoma after radical resection. However, the completion rate of chemotherapy was low, so it was necessary to explore reasonable regimens to improve the completion rate and carry out prospective randomized controlled trial.

[The value of the planned neoadjuvant radiotherapy or chemoradiotherapy for the non-radical resection of esophageal squamous cell carcinoma]

Objective: The role of planned neoadjuvant radiotherapy or chemoradiotherapy in the non-radical resection of esophageal squamous cell carcinoma was unclear. The study aimed to evaluate their therapeutic effect and analyze the prognostic factors. Methods: We retrospectively analyzed the clinical data of locally advanced esophageal squamous cell carcinoma who received neoadjuvant radio therapy (33 patients) and concurrent chemoradiotherapy (119 patients) from January 2004 to December 2016 in our single-institution database.The survival rates were calculated by Kaplan-Meier method. The prognostic factors were analyzed by using Log rank test and Cox proportional hazards model. Results: The median follow-up was 29.8 months. One hundred and one patients survived more than 3 years. The rates of overall survival (OS) and disease-free survival (DFS) at 3 years were 63.9% and 55.6%, respectively.The rates of complete, partial and minimal pathological response of the primary tumor were 50.3%, 38.4%, 11.3%, the corresponding 3-year OS were 75.5%, 57.4%, 27.3% (P<0.001) and 3-year DFS were 72.0%, 44.7%, 17.6% (P<0.001), respectively.The postoperative lymph node metastasis rate was 27.0%. The 3-year OS and DFS of the lymph node positive group was 45.6% and 32.8%, significantly lower than 70.8% and 63.7% of the negative group (both P<0.001). The 3-year OS and DFS of pathologic stage Ⅰ, Ⅱ, ⅢA, ⅢB and Ⅵ A were 76.2%, 57.4%, 64.7%, 35.0%, 33.3% (P<0.001) and 70.1%, 49.3%, 41.2%, 22.1%, 33.3% (P<0.001), respectively.The operation-related mortality was 3.3%. Multivariate analysis showed that chest pain, postoperative respiratory failure, pathological differentiation, more than 15 lymph node dissection and ypTNM stage were the independent prognostic factors of OS (P<0.05 for all). Conclusions: The planned neoadjuvant radiotherapy or chemoradiotherapy for the non-radical resection of advanced esophageal squamous cell carcinoma could result in favorable survival. The chest pain, postoperative respiratory failure, pathological differentiation, the number of lymph node resection and ypTNM stage are the independent prognostic factors of the prognosis of these patients.

[Prognostic value of pretreatment neutrophil-to-lymphocyte ratio (NLR) in locally advanced non-small cell lung cancer patients treated with thoracic radiation]

Objective: The aim of this retrospective study was to evaluate the prognostic significance of pretreatment Neutrophil-to-Lymphocyte Ratio(NLR) in locally advanced non-small cell lung cancer(NSCLC) patients treated with thoracic radiotherapy. Methods: We retrospectively analyze 420 patients who received thoracic radiotherapy alone, sequential chemoraiotherapy or concurrent chemoradiotherapy for locally advanced stage NSCLC from January 2007 to December 2010 of our hospital. The patients were divided into two groups (high NLR group and low NLR group) with appropriate cutoff point using the receiver operating characteristic (ROC) curve method. The survival curve was established by Kaplan-Meier method. The Log-rank test was used to compare the survival of the two NLR groups and the multivariate analysis was carried out by Cox regression model. Results: Among the 420 patients, 99 received radiotherapy alone, 139 received sequential chemoradiotherapy and 182 received concurrent chemoradiotherapy. 345 patients died and 75 were still alive. The median follow-up time was 5.2 years and the median overall survival was 22 months. The cut-off value of pretreatment NLR was 2.1. The 5-year PFS and OS rates in high NLR group and low NLR group were 10.6% vs 15.7% (P=0.033) and 15.5% vs 22.7% (P=0.012). Multivariate analysis confirmed that pretreatment NLR (hazard ratio 1.06, P=0.041) was independent prognostic factor of OS. Conclusions: Our study revealed that the pretreatment NLR is the independent prognostic factor of OS in patients with locally advanced stage NSCLC treated with thoracic radiotherapy. However, NLR is still greatly influenced by patient's condition and treatment which needs further research.

[Clinical analysis of 138 multiple primary cancers diagnosed of digestive system malignant tumor initially]

Objective: To study the clinical characteristics, strategy of treatment and prognosis of multiple primary cancers(MPC) diagnosed of digestive system malignant tumor firstly. Methods: From January, 2000 to December, 2015, the clinical, follow-up and prognostic data of 138 MPC patients diagnosed of digestive system malignant tumor firstly were retrospectively analyzed. Results: 138 cases were found in 10 580 cases with malignant tumors, and the incidence was 1.30%. There were 129 cases of duplex primary cancers, 8 cases of triple primary cancers and 1 case of quintuple primary cancers. The repetitive primary cancer was occurred in digestive system (61cases, 44.2%) most frequently, with the next in respiratory system (46 cases, 33.3%). 52.2% (72 cases) suffered second primary cancer in 2 years after first primary cancer diagnosed, and 75.4% (104 cases) in 5 years. The median overall survival in patients with all cancer lesions radically treated was 168 months, better than any other treatment (68 months, P<0.05). Conclusions: The second primary cancers of MPC cases initially diagnosed of digestive system malignant tumor most frequently occurred in the digestive system and respiratory system. More concern should be attracted in follow-up, especially in the first 5 years. The key to improve patient' prognosis was radical treatment to every primary cancer.

[Technical advancement improves survival in patients with locally advanced non-small cell lung cancer (LA-NSCLC) receiving definitive radiotherapy]

OBJECTIVE

This study aimed to evaluate the impact of technical advancement of radiation therapy in patients with LA-NSCLC receiving definitive radiotherapy (RT).

METHODS

Patients treated with definitive RT (≥50 Gy) between 2000 and 2010 were retrospectively reviewed. Overall survival (OS), cancer specific survival (CSS), locoregional progression-free survival (LRPFS), distant metastasis-free survival (DMFS) and progression-free survival (PFS) were calculated and compared among patients irradiated with different techniques. Radiation-induced lung injury (RILI) and esophageal injury (RIEI) were assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events 3.0 (NCI-CTCAE 3.0).

RESULTS

A total of 946 patients were eligible for analysis, including 288 treated with two-dimensional radiotherapy (2D-RT), 209 with three-dimensional conformal radiation therapy (3D-CRT) and 449 with intensity-modulated radiation therapy (IMRT) respectively. The median follow-up time for the whole population was 84.1 months. The median OS of 2D-RT, 3D-CRT and IMRT groups were 15.8, 19.7 and 23.3 months, respectively, with the corresponding 5-year survival rate of 8.7%, 13.0% and 18.8%, respectively (P<0.001). The univariate analysis demonstrated significantly inferior OS, LRPFS, DMFS and PFS of 2D-RT than those provided by 3D-CRT or IMRT. The univariate analysis also revealed that the IMRT group had significantly loger LRPFS and a trend toward better OS and DMFS compared with 3D-CRT. Multivariate analysis showed that TNM stage, RT technique and KPS were independent factors correlated with all survival indexes. Compared with 2D-RT, the utilization of IMRT was associated with significantly improved OS, LRPFS, DMFS as well as PFS. Compared with 3D-CRT, IMRT provided superior DMFS (P=0.035), a trend approaching significance with regard to LRPFS (P=0.073) but no statistically significant improvement on OS, CSS and PFS in multivariate analysis. The incidence rates of RILI were significantly decreased in the IMRT group (29.3% vs. 26.6% vs.14.0%, P<0.001) whereas that of RIET rates were similar (34.7% vs. 29.7% vs. 35.3%, P=0.342) among the three groups.

CONCLUSIONS

Radiation therapy technique is a factor affecting prognosis of LA-NSCLC patients. Advanced radiation therapy technique is associated with improved tumor control and survival, and decreased radiation-induced lung toxicity.