Research on the Composition and Distribution of Organic Sulfur in Coal.

The structure and distribution of organic sulfur in coals of different rank and different sulfur content were studied by combining mild organic solvent extraction with XPS technology. The XPS results have shown that the distribution of organic sulfur in coal is related to the degree of metamorphism of coal. Namely, thiophenic sulfur content is reduced with decreasing metamorphic degree; sulfonic acid content rises with decreasing metamorphic degree; the contents of sulfate sulfur, sulfoxide and sulfone are rarely related with metamorphic degree. The solvent extraction and GC/MS test results have also shown that the composition and structure of free and soluble organic sulfur small molecules in coal is closely related to the metamorphic degree of coal. The free organic sulfur small molecules in coal of low metamorphic degree are mainly composed of aliphatic sulfides, while those in coal of medium and high metamorphic degree are mainly composed of thiophenes. Besides, the degree of aromatization of organic sulfur small molecules rises with increasing degree of coalification.

Studies on the Low-Temp Oxidation of Coal Containing Organic Sulfur and the Corresponding Model Compounds.

This paper selects two typical compounds containing organic sulfur as model compounds. Then, by analyzing the chromatograms of gaseous low-temp oxidation products and GC/MS of the extractable matter of the oxidation residue, we summarizing the mechanism of low-temp sulfur model compound oxidation. The results show that between 30°C to 80°C, the interaction between diphenyl sulfide and oxygen is mainly one of physical adsorption. After 80°C, chemical adsorption and chemical reactions begin. The main reaction mechanism in the low-temp oxidation of the model compound diphenyl sulfide is diphenyl sulfide generates diphenyl sulfoxide, and then this sulfoxide is further oxidized to diphenyl sulphone. A small amount of free radicals is generated in the process. The model compound cysteine behaves differently from diphenyl sulfide. The main reaction low-temp oxidation mechanism involves the thiol being oxidized into a disulphide and finally evolving to sulfonic acid, along with SO2 being released at 130°C and also a small amount of free radicals. We also conducted an experiment on coal from Xingcheng using X-ray photoelectron spectroscopy (XPS). The results show that the major forms of organic sulfur in the original coal sample are thiophene and sulfone. Therefore, it can be inferred that there is none or little mercaptan and thiophenol in the original coal. After low-temp oxidation, the form of organic sulfur changes. The sulfide sulfur is oxidized to the sulfoxide, and then the sulfoxide is further oxidized to a sulfone, and these steps can be easily carried out under experimental conditions. What's more, the results illustrate that oxidation promotes sulfur element enrichment on the surface of coal.

Comparing tocilizumab biosimilar BAT1806/BIIB800 with reference tocilizumab in patients with moderate-to-severe rheumatoid arthritis with an inadequate response to methotrexate: a phase 3, randomised, multicentre, double-blind, active-controlled clinical trial.

BACKGROUND: Biosimilars provide an opportunity to address unmet medical need by expanding access to biological treatments. This study aimed to show equivalent efficacy, and comparable safety, immunogenicity, and pharmacokinetic profiles of a proposed tocilizumab biosimilar BAT1806/BIIB800, to reference tocilizumab, in participants with rheumatoid arthritis with an inadequate response to methotrexate. METHODS: This phase 3, multicentre, randomised, double-blind, active-controlled, equivalence study comprised a 24-week initial treatment period (results reported here) and a 24-week secondary treatment period. Participants were recruited at 54 centres across five countries (China, Ukraine, Poland, Georgia, and Bulgaria). Patients with active rheumatoid arthritis with an inadequate response to methotrexate were randomly assigned (1:1:2) to receive reference tocilizumab up to week 48, or reference tocilizumab up to week 24 followed by BAT1806/BIIB800 up to week 48 (the two reference tocilizumab groups were analysed as a single group in this analysis), or BAT1806/BIIB800 up to week 48 (the BAT1806/BIIB800 group), administered by intravenous infusion once every 4 weeks at a starting dose of 8 mg/kg. The primary endpoint was the proportion of participants who had a 20% improvement in American College of Rheumatology criteria (ACR20) at week 12 (for the European Medicines Agency [EMA]) or week 24 (for the US Food and Drug Administration [FDA] and China National Medical Products Administration [NMPA]) using prespecified equivalence margins (95% CI -14·5 to +14·5 [EMA], 90% CI -12·0 to +15·0 [FDA], and 95% CI -13·6 to +13·6 [NMPA]). The International Council for Harmonisation E9(R1) estimand framework, with strategies for addressing intercurrent events, was implemented for the efficacy evaluations with expected differences as per the predefined equivalence margins. This trial is registered at ClinicalTrials.gov (NCT03830203) and EudraCT (2018-002202-31), and is closed to new participants. FINDINGS: Between Dec 19, 2018, and Jan 5, 2021, we randomly assigned 621 participants: 309 to the reference tocilizumab group and 312 to the BAT1806/BIIB800 group. The mean age was 50·5 years (SD 12·0), 534 (86%) were women, 87 (14%) were men, and 368 (59%) were White. For the primary estimands, estimated ACR20 response rates were 64·8% in the reference tocilizumab group and 69·0% in the BAT1806/BIIB800 group (treatment difference 4·1% [95% CI -3·6 to 11·9]) at week 12, and 67·9% in the reference tocilizumab group and 69·9% in the BAT1806/BIIB800 group (treatment difference 1·9% [90% CI -4·0 to 7·9; 95% CI -5·2 to 9·1]) at week 24. All confidence intervals were contained within the predefined equivalence margins. Comparable pharmacokinetic and immunogenicity profiles were observed for the reference tocilizumab and BAT1806/BIIB800 groups. Adverse events were reported by 201 (65%) participants in the reference tocilizumab group and 206 (66%) in the BAT1806/BIIB800 group; 196 (63%) participants in the reference tocilizumab group and 201 (64%) participants in the BAT1806/BIIB800 group reported a treatment-emergent adverse event. Five participants had a fatal event (reference tocilizumab n=1; BAT1806/BIIB800 n=4). INTERPRETATION: BAT1806/BIIB800 showed equivalent efficacy, and comparable safety, immunogenicity, and pharmacokinetic profiles as reference tocilizumab. FUNDING: Bio-Thera Solutions and Biogen.

Separation and identification of flavonoids from fistular onion stalk (Allium fisturosum L. var. Caespitosum Makio).

The chemical constituents of fistular onion stalk obtained by supercritical CO(2) extraction were separated and purified by silica gel and sephadex LH-20 gel column chromatography and the preparative TLC method and four flavonoids were obtained. On the basis of the spectral data, they were structurally identified as (+)-catechin, (-)-epicatechin, astragalin, and 3-O-beta-D(2-O-beta-D-glucopyranosyl)-glucopyranosides of kaempferol.

A Phase I Clinical Study Comparing the Tolerance, Immunogenicity, and Pharmacokinetics of Proposed Biosimilar BAT1806 and Reference Tocilizumab in Healthy Chinese Men.

Objective: The study aimed to explore the bioequivalence of a proposed biosimilar BAT1806 to its reference products marketed in the EU and US (RoActemra-EU and Actemra-US) among healthy Chinese men. The tolerance, immunogenicity, and pharmacokinetics (PK) of the three drugs were also investigated. Methods: In this randomized, double-blind, single-dose, three-arm, parallel study, a single-dose of 4 mg/kg of the reference products, or the biosimilar was administered to the participants. The participants were followed up for 57 days, and PK, immunogenicity, and tolerance evaluations were completed during this period. Results: The PK parameters were similar in all three groups: BAT1806 (n = 45), RoActemra-EU (n = 42), and Actemra-US (n = 42). The 90% confidence intervals (CIs) for the ratios of C max , AUC0-t and AUC0-∞ were 86.90-104.41% for BAT1806 vs. RoActemra-EU, 91.70-106.15% for BAT1806 vs Actemra-US, and 90.04-105.53% for Actemra-US vs RoActemra-EU. For all comparisons, the 90% CIs for the C max , AUC0-t , and AUC0-∞ were within the predefined bioequivalence limit of 80.00-125.00%. The intersubject variability ranged from 14.5% to 21.5%, which was considerably low. Among the participants, 19 (42.2%), 10 (23.8%), and 12 (28.6%) from the BAT1806, RoActemra-EU, and Actemra-US groups were, respectively, found to be positive for anti-drug antibodies, while 14 (31.1%), nine (21.4%), and 12 (28.6%) were positive for neutralizing antibodies. Nevertheless, these antibodies did not affect the drug concentrations, and the outcomes in the bioequivalence tests were similar after sensitivity analysis. Treatment-related and treatment-emergent adverse events (TEAEs) were recorded in 27, 34, and 32 participants in the BAT1806, RoActemra-EU, and Actemra-US groups, respectively. The most common treatment-related adverse events observed were a decrease in neutrophil, and white blood cell counts. Conclusion: The PK characteristics of BAT1806 were similar to those of the reference products, RoActemra-EU and Actemra-US. Both BAT1806 and the reference products exhibited low intersubject variability and similar safety profiles. Clinical trial registration number: http://www.chinadrugtrials.org.cn/index.html, CTR20180039; https://clinicaltrials.gov/NCT03606876.

Free radical reaction characteristics of coal low-temperature oxidation and its inhibition method.

Study on the mechanism of coal spontaneous combustion is significant for controlling fire disasters due to coal spontaneous combustion. The free radical reactions can explain the chemical process of coal at low-temperature oxidation. Electron spin resonance (ESR) spectroscopy was used to measure the change rules of the different sorts and different granularity of coal directly; ESR spectroscopy chart of free radicals following the changes of temperatures was compared by the coal samples applying air and blowing nitrogen, original coal samples, dry coal samples, and demineralized coal samples. The fragmentation process was the key factor of producing and initiating free radical reactions. Oxygen, moisture, and mineral accelerated the free radical reactions. Combination of the free radical reaction mechanism, the mechanical fragmentation leaded to the elevated CO concentration, fracturing of coal pillar was more prone to spontaneous combustion, and spontaneous combustion in goaf accounted for a large proportion of the fire in the mine were explained. The method of added diphenylamine can inhibit the self-oxidation of coal effectively, the action mechanism of diphenylamine was analyzed by free radical chain reaction, and this research can offer new method for the development of new flame retardant.