Experimental Study on the Influence of Ignition Position on the Overpressure of Hydrogen Jet Flame.

The accidental leakage of hydrogen poses a significant barrier to the widespread adoption and development of hydrogen energy due to the potential risks of fire, explosion, and jet fire hazards. Experimental investigations have been conducted on the process of jet fires formed by igniting hydrogen jet streams after accidental releases in scenarios such as high-pressure hydrogen gas storage tanks and hydrogen transmission pipelines. These experiments utilized a release pipe with a diameter of 10 mm and a length of 0.75 m, along with three pressure sensors, to study the influence of release pressure and ignition position on jet flame overpressure and flame propagation. Extensive tests at 1.5 MPa yielded a hydrogen flammability map containing two nonflammable zones and one flammable zone, along with a graph illustrating the relationship between overpressure and ignition points. Furthermore, experiments conducted at ignition positions of 0.05, 0.5 and 1.0 m under release pressures ranging from 6 to 10 MPa revealed that release pressure had no significant effect, while ignition position notably influenced the waveform and peak of the shockwave. Additionally, a peak shockwave reaching 30 kPa was observed at the downstream of the pipe outlet when ignited at 0.05 m, far exceeding the threshold of 24 kPa associated with fatalities. This research aims to provide valuable insights for safety design and protection distance considerations in scenarios involving hydrogen release and ignition.

Experimental Study of the Effect of CO/H2 Ratio and Release Pressure on Syngas Jet Flame Propagation and Overpressure.

Syngas, composed of hydrogen and carbon monoxide, serves as an alternative fuel for hydrogen energy and a key raw material for chemical synthesis. However, due to its flammable nature, syngas poses risks of forming explosive mixtures in the event of a leak. This study explores potential accident scenarios in coal chemical environments involving syngas reaction vessels. Experimental investigations focus on the overpressure and propagation dynamics of jet flames resulting from syngas leakage, with CO volume fractions ranging from 50 to 80% and release pressures between 2 and 5 MPa. Results reveal that maximum flame overpressure occurs within a CO volume fraction range of 55-65%, with no consistent relationship observed between overpressure and CO fraction at fixed release pressures. During our experiments, the maximum recorded overpressure of 28.4 kPa was reached during vented explosions. Additionally, ignition outcomes categorize into three types based on flame propagation speed: combustion/flare, resembling normal deflagration; and high-velocity deflagration, characterized by rapid propagation and potential for steady jet fire formation. While shockwave-like features may be observed, these do not indicate true detonation. These findings offer insights for the safe handling and storage of syngas.

Paeoniflorin ameliorates oxaliplatin-induced peripheral neuropathy via inhibiting neuroinflammation through influence on gut microbiota.

Oxaliplatin (OXA)-induced peripheral neuropathy (OIPN) is a severe side effect that greatly limits OXA clinical use and threatens patients' life and health. Paeoniflorin exhibits extensive anti-inflammatory and neuroprotective effects, but whether it can protect against OIPN and the underlying mechanisms remain unclear. This study aimed to investigate the effects of paeoniflorin on OIPN and probe into the underlying mechanisms. The OIPN model was established through oxaliplatin injection in rats. The ameliorative effects of paeoniflorin on OIPN was assessed by nociceptive hypersensitivities through pain behavioral methods. Neuroinflammation were examined by measuring the levels of inflammatory cytokines and immune cells infiltration. The signaling pathway of TLR4/MyD88/NF-κB was evaluated by Western blotting. Gut microbial changes were detected by 16S rDNA sequencing technology. In addition, antibiotics-induced microbiota eradication and fecal microbial transplantation (FMT) were applied for exploring the function of gut microbiota in the protective effects of paeoniflorin. The results revealed that paeoniflorin significantly alleviated mechanical and cold hypersensitivity, mitigated neuroinflammation and influenced gut microbial composition in OIPN rats. Fecal microbiota transplantation further verified that gut microbiota was required for paeoniflorin ameliorating OIPN and that the underlying mechanism involved downregulation of TLR4/MyD88/NF-κB signaling. Specifically, Akkermansia, Dubosiella and Corynebacterium might serve as crucial genera regulated by paeoniflorin in the treatment of OIPN. In summary, our investigations delineate paeoniflorin's ameliorative effects on OIPN by alleviating neuroinflammation through regulations of gut microbiota. This suggests that paeoniflorin may serve as a new potential strategy for treatment of OIPN in clinical practice.

Salvianolic acid extract prevents Tripterygium wilfordii polyglycosides-induced acute liver injury by modulating bile acid metabolism.

ETHNOPHARMACOLOGICAL RELEVANCE: Tripterygium wilfordii polyglycosides (TWP) tablet is the most widely used traditional Chinese medicine preparation for the treatment of rheumatoid arthritis (RA), but the hepatotoxicity often limits its widespread application. In traditional use, Salvia miltiorrhiza has cardioprotective and hepatoprotective effects. Salvianolic acid extract (SA) is a hydrophilic component of Salvia miltiorrhiza and has significant antioxidant and hepatoprotective effects. AIM OF THE STUDY: To investigate the protective effects of SA on the TWP-induced acute liver injury in rats and to explore the related mechanisms by integration of metabolomics and transcriptomics. MATERIALS AND METHODS: SA and TWP extracts were identified by UPLC-Q/TOF-MS. SA (200 mg/kg) was administered for consecutive 7 days. On day 7, TWP (360 mg/kg) was administered by gavage to induce the acute liver injury in rats. Serum biochemical assay and H&E staining were used to evaluate liver damage. Liver metabolomics and transcriptomics were used to explore the potential mechanisms, and further molecular biological experiments such as qPCR and IHC were utilized to validate the relevant signaling pathways. RESULTS: SA can prevent liver injury symptoms caused by TWP, such as elevated liver index, elevated ALT and AST, and pathological changes in liver tissue. Liver metabolomics studies showed that TWP can significantly alter the content of individual bile acid in the liver and SA had the most significant impact on the biosynthetic pathway of bile acids. The transcriptomics results of the liver indicated that the genes changed in the SA + TWP group were mainly involved in sterol metabolism, lipid regulation and bile acid homeostasis pathways. The gene expression of Nr1h4, which encodes farnesoid X receptor (FXR), an important regulator of bile acid homeostasis, was significantly changed. Further studies confirmed that SA can prevent the downregulation of FXR and its downstream signaling induced by TWP, thereby regulating bile acid metabolism, ultimately preventing acute liver injury caused by TWP. CONCLUSION: Our results demonstrated that SA could protect the liver from TWP-induced hepatic injury by modulation of the bile acid metabolic pathway. SA may provide a new strategy for the protection against TWP-induced acute liver injury.

[Comparison on blood-prostate barrier permeability of tanshinone extract and corresponding major monomers].

In this study, the transmittance of tanshinone Ⅱ_A(Tan Ⅱ_A) and cryptotanshinone(CTS) through the blood-prostate barrier and their distributions in the prostate tissue were compared between tanshinone extract(Tan E) treatment group and the corresponding monomer composition group under the equivalent dose conversion in vitro and in vivo. First, the human prostate epithelial cell line RWPE-1 was cultured in vitro for 21 days for the establishment of a blood-prostate barrier model, and the transmission of Tan Ⅱ_A and CTS through the barrier model was investigated after administration of Tan E and corresponding single active components. Second, SD rats were administrated with 700 mg·kg~(-1) Tan E, 29 mg·kg~(-1) CTS, and 50 mg·kg~(-1) Tan Ⅱ_A by gavage, and plasma and prostate tissue samples were collected at the time points of 2, 4, 8, 12, and 24 h. The Tan Ⅱ_A and CTS concentrations in the samples were determined. The results showed that in the cell model, the cumulative transmission amounts of CTS and Tan Ⅱ_A in the extract at each time point were higher than those of the corresponding single active components(P<0.01). In rats, after the administration of Tan E, the concentrations of Tan Ⅱ_A and CTS in rat plasma and prostate were higher than those of the corresponding single active components. This study demonstrated that the coexisting components in Tan E promoted the penetration of its main pharmacological components Tan Ⅱ_A and CTS through the blood-prostate barrier. The findings provide a theoretical and experimental basis for the application of Tan E in the clinical treatment of prostate-related diseases.