Objective:To establish a GC method for the determination of phenol and L-menthol in glycerin Zhiyang lotions. Meth-ods:A Zebron ZB-WAX(0. 32 mm × 30. 0 m,0. 50 μm) capillary column was used with an FID detector. The column temperature was 60℃, maintained for 1 min, and then raised to 160℃ at the rate of 8℃·min-1 , and maintained 10 minutes. The inlet tempera-ture was 180℃, the detector temperature was 300℃, and the carrier gas was nitrogen. Results:The linear range of phenol and L-men-thol was 0. 5-10. 0 mg·ml-1(r=0. 999 9) and 0. 25-5. 0 mg·ml-1(r=0. 999 9), respectively. The average recovery of phenol and L-menthol was 99. 01%(RSD=0. 90%,n=9)and 99. 70%(RSD=0. 98%,n=9), respectively. Conclusion: The method is sim-ple, accurate and reliable, and can be used to determine the concentration of phenol and L-menthol in glycerin Zhiyang lotions.

Objective:To explore the feasibility of high-flow nasal cannula(HFNC)therapy for respiratory failure in elderly patients.Methods:A total of 300 patients with respiratory failure admitted to Peking University Shougang Hospital from December 2016 to March 2019 were enrolled in this prospective study.Patients were divided into three groups: the HFNC group, the conventional oxygen therapy(COT)group and the non-invasive positive pressure ventilation(NPPV)group(n=100 in each group). Arterial oxygen saturation(SPO 2), oxygen index(OI), heart rate(HR), respiratory rate(RR), mean arterial pressure(MAP), comfort level, discharge rate, tracheal intubation rate, rate of referral to ICU, mortality and rate of referral to another group after therapy were compared between the HFNC and COT groups and between the HFNC and NPPV groups. Results:SPO 2 after oxygen therapy for 30 minutes( t=-2.992, P=0.003), 1 hour( t=-2.884, P=0.005)and 6 hours( t=-3.196, P=0.002)and OI before discharge( t=-2.060, P=0.048)were higher in the HFNC group than in the COT group.The HR in the above two groups was lower before discharge than before therapy, and the HR in the COT group was even lower(73.1±25.1 beat per minute vs.75.1±25.9 beat per minute), but both were within the normal range.The discharge rate was higher( χ2=-1.969, P=0.049), while the rate of referral to another group was lower in the HFNC group than in the COT group( χ2=-3.115, P=0.002). There was no significant difference in the tracheal intubation rate, ICU transfer rate and mortality between the HFNC and COT groups.SPO 2 after oxygen therapy for 30 minutes( t=-2.026, P=0.046)and 6 hours( t=-2.101, P=0.040)were higher in the HFNC group than in the NPPV group, but there was no significant difference in OI and SPO 2 between the two groups before discharge.The HR in both HFNC and NPPV groups was lower before discharge than before therapy, and there was no statistical difference between the two groups.The mortality, discharge rate, tracheal intubation rate, ICU transfer rate and rate of referral to another group had no significant difference between the HFNC and NPPV groups.The comfort level was higher in the HFNC group than in the COT and NPPV groups( t=-3.758 and -19.180, both P=0.000). Conclusions:HFNC is a new type of oxygen therapy equipment introduced after COT and NPPV, and possesses more advantages for elderly patients with respiratory failure.

Objective:To summarize the experience and early outcomes of transapical mitral valve-in-valve procedure with J-Valve in patients with bioprostheses degeneration.Methods:The clinical data of 29 patients who underwent mitral transcatheter valve-in-valve implantation with J-Valve from April 2020 to March 2021 were retrospectively analyzed. There were male 16 and female 13 patients with average age (72.0±11.6) years. Patients underwent previous mitral valve replacement with bioprostheses of Hancock Ⅱ in 17, Edwards SAV in 7, Edwards Perimount in 3, Balmedic in 1, Mosaic in 1. The size of mitral bioprostheses included 25 # for 8 patients, 27 # for 17 patients, and 29 # for other 4 patients. The operations were performed in the hybrid operation room. Under X-ray fluoroscopy and TEE monitoring, the retro-preseted J-valve was implanted into the mitral bioprosthetic valve via the intercostal space and apical puncture. Results:One patient was converted urgently to mediate sternotomy, and the transcatheter mitral valve was reset after opening left atrium on cardiopulmonary bypass due to the migration of transcatheter valve. twenty eight patients were successfully completed transcatheter mitral valve-in-valve procedure with technical success achieving in 96.6% . Among the 28 patients who successfully were completed valve-in-valve procedure, 1 died and 27 were discharged in well condition. The mean mitral transvalvular gradient was (7.6±2.2)mmHg(1 mmHg=0.133 kPa), no death or other major complications occurred during the follow-up.Conclusion:The application of J-Valve interventional valve in patients with bioprosthesis degeneration can achieve favourable early outcomes, even if the patient was replaced with a small bioprosthesis in the previous operation, the hemodynamic effect was still satisfactory.

BACKGROUND:Due to the unstable drug release rate of uniaxial bone scaffolds,multi-structure composite printing methods have been sought in and outside China in recent years.Currently,coaxial drug-loaded bone scaffolds,which combine drug-loaded sustained release system with bone transplantation and repair technology,not only replace the defective bone after implantation,but also release drugs slowly,providing a microenvironment conducive to bone formation at the implant site. OBJECTIVE:To explore and assess the in vitro antibacterial properties of uniaxial and coaxial minocycline hydrochloride bone scaffolds. METHODS:Rapid prototyping technology was used to prepare uniaxial hydroxyapatite/silk fibroin-polyvinyl alcohol scaffold,uniaxial hydroxyapatite/silk fibroin-polyvinyl alcohol scaffold,coaxial hydroxyapatite/silk fibroin-polyvinyl alcohol scaffold,and coaxial hydroxyapatite/silk fibroin-polyvinyl alcohol scaffold,respectively,which were named S1,S2,T1 and T2.The morphology,porosity,degradation performance,in vitro sustained-release performance and cytotoxicity of scaffolds were characterized.Four kinds of bone scaffolds were immersed in PBS to prepare the extracts at different time points(1,3,5,7,14,21,and 28 days).The qualitative filter paper was placed into the extract for 24 hours.The filter paper was co-cultured with Porphyromonas gingivalis and Fusobacterium nucleatum for 72 hours.The bacteriostatic effect of four groups of scaffolds was detected by the agar diffusion method. RESULTS AND CONCLUSION:(1)Scaffold characterization:Four groups of scaffolds were well formed.The surface of micro-wires in the S1 and S2 groups was dense and smooth,and the surface of micro-wires in the T1 and T2 groups was rough.Porosity was between 40%-47%and met the requirements of bone scaffolds.Compared with the S2 group,sustained release time was longer in the T2 group.The sustained release concentration of the drug was between 1-10 μg/mL for a long time,which was more conducive to bacteriostasis and osteogenesis.After 10 weeks of immersion in PBS in vitro,the degradation rate of the coaxial printed bone scaffold was faster than that of the corresponding uniaxial printed bone scaffold,and the degradation rate of the coaxial loaded bone scaffold was lower than that of the coaxial non-loaded bone scaffold.The four groups of scaffold extracts were co-cultured with osteoblasts respectively.CCK-8 assay displayed that the cell proliferation rate was greater than 75%,which met the requirements of biocompatibility.(2)In vitro antibacterial effect:S1 and T1 did not have antibacterial activity.S2 and T2 had an obvious antibacterial effect.Under the extraction solution on day 28,the diameter of Porphyromonas gingivalis and Fusobacterium nucleatum inhibition zone in the S2 group was smaller than that in the T2 group(P<0.05).(3)These findings exhibit that hydroxyapatite/silk fibroin-polyvinyl alcohol scaffolds with coaxial minocycline have good physical properties and bacteriostatic properties.