Objective To investigate a rapid detection method for compressed Nitrous oxide(N2O).Methods The GC-MS system was employed under conventional chromatographic conditions(without replacing standard columns or utilizing headspace sampling)by directly injecting a small gas sample for analysis.N2O identification was performed via NIST spectral library matching,while qualitative and quantitative purity assessments were achieved by monitoring the relative abundance variation of the characteristic fragment ion m/z 30 to eliminate CO2 interference.Results The fragment ion m/z 30 demonstrated specificity for N2O identification.A linear correlation was observed between the peak area of m/z 30 and N2O purity(y=22.741x-1.4565,R2=0.912 6),enabling quantitative purity determination.Additionally,the abundance of m/z30 exhibited a correlation with N2O in CO2 mixtures(y=0.7787x-0.0387,R2=0.722 2).Conclusion Conventional N2O identification typically requires dedicated GC-MS systems,gas-specific chromatographic columns,and headspace sampling.This study successfully utilized routine chromatographic conditions for organic toxicant screening to achieve rapid N2O analysis.The proposed method holds practical significance for compressed N2O identification in forensic and analytical applications.

Objective To investigate a rapid detection method for compressed Nitrous oxide(N2O).Methods The GC-MS system was employed under conventional chromatographic conditions(without replacing standard columns or utilizing headspace sampling)by directly injecting a small gas sample for analysis.N2O identification was performed via NIST spectral library matching,while qualitative and quantitative purity assessments were achieved by monitoring the relative abundance variation of the characteristic fragment ion m/z 30 to eliminate CO2 interference.Results The fragment ion m/z 30 demonstrated specificity for N2O identification.A linear correlation was observed between the peak area of m/z 30 and N2O purity(y=22.741x-1.4565,R2=0.912 6),enabling quantitative purity determination.Additionally,the abundance of m/z30 exhibited a correlation with N2O in CO2 mixtures(y=0.7787x-0.0387,R2=0.722 2).Conclusion Conventional N2O identification typically requires dedicated GC-MS systems,gas-specific chromatographic columns,and headspace sampling.This study successfully utilized routine chromatographic conditions for organic toxicant screening to achieve rapid N2O analysis.The proposed method holds practical significance for compressed N2O identification in forensic and analytical applications.

Background: The association between high thyrotropin receptor antibody (TRAb) titers at diagnosis and long-term outcomes following prolonged antithyroid drug (ATD) therapy in Graves’ disease (GD) remains unclear. This study examined TRAb dynamics and outcomes in high-titer patients receiving prolonged ATD. Methods: In this retrospective cohort (2018–2021), 1,148 of 3,052 newly diagnosed GD patients met inclusion criteria (≥18-month ATD course, TRAb negativity before withdrawal, and ≥12-month follow-up). Initial TRAb levels were defined as low-titer (<5.25 IU/L, 3×upper normal limit [UNL]), intermediate-titer (5.25–10.5 IU/L), and high-titer (>10.5 IU/L, 6×UNL). Outcomes included TRAb dynamics, treatment duration, and relapse. Results: High-titer patients required longer therapy (50 months vs. 30 months vs. 22 months, P<0.001) and slower thyroid-stimulating hormone normalization (6 months vs. 4 months vs. 2 months, both P<0.001). TRAb negativity at 24/48 months occurred in 91.85%/99.26% (low-titer), 52.38%/75.24% (intermediate-titer), and 12.70%/52.68% (high-titer) (P<0.001). High-titer patients showed fluctuant (46.20%) or smoldering (28.89%) trends. Remission rates declined with higher TRAb titer (60.45% vs. 42.70% vs. 30.47%, P<0.001). High-titer patients showed increased risk of persistent TRAb positivity (2.17-fold; 95% confidence interval [CI], 1.55 to 3.05) and relapse (1.66-fold; 95% CI, 1.45 to 3.22). Thresholds of 10.90 IU/L and 16.01 IU/L predicted positivity and relapse, respectively. Definitive therapy post-relapse was more common in high-titer patients (38.29% vs. 16.98% in low-titer, P<0.001). Conclusion High TRAb titers strongly predict persistent TRAb positivity and relapse after ATD withdrawal. Cut-off at 10.90 and 16.01 IU/L may guide prognosis and treatment.

AIM: To investigate the effect of extracorporeal membrane oxygenation (ECMO) on the pharmacokinetics/pharmacodynamics (PK/PD) of daptomycin in critically ill patients. METHODS: Twenty four patients with severe infection in our hospital were randomly selected and divided into ECMO group and non ECMO group. They were intravenously injected with daptomycin 500 mg qd. After the drug reached the stability statement, venous blood was collected at different time points before and after the infusion. The plasma drug concentration was measured and the pharmacokinetic parameters were calculated. The probability target acquisition (PTA) and the cumulative fraction response (CFR) were calculated by Monte Carlo simulation. RESULTS: After dosing, the main pharmacokinetic parameters in ECMO and non-ECMO group were calculated and listed as follows: C

Objective:To investigate the role of Linc00339 in the development of triple-negative breast cancer and its related molecular mechanisms.Methods:The expression levels of Linc00339 in human normal breast epithelial cells and breast cancer cells were detected by real time fluorescent quantitative polymerase chain reaction (qRT-PCR). The Linc00339 was overexpressed in MDA-MB-231 cells by plasmid transfection test; the activity of MDA-MB-231 cells was detected by methyl thiazolyl tetrazolium (MTT) method; the adhesion, invasion and migration ability of MDA-MB-231 cells were detected by adhesion test and transwell test respectively; Western blot was used to detect the expression of APC and Wnt/β-catenin signaling pathway-related proteins in MDA-MB-231 cells. qRT-PCR was used to detect the expression of miRNA-135a, miRNA-135b and miRNA-138 in MDA-MB-231 cells. MDA-MB-231 cells were successfully transfected into nude mice to establish tumor-bearing nude mice model. The volume and weight of tumor were observed and measured. The expression levels of APC, Wnt/β - catenin signaling pathway related proteins were detected by Western blot, and the expression levels of miRNA-135a, miRNA-135b and miRNA-138 were detected by qRT-PCR.Results:Compared with the normal breast epithelial cell group (Hs578Bst), the expression level of Linc00339 in breast cancer cell lines (MCF-7, MDA-MB-468, MDA-MB-231) was significantly up-regulated, especially MDA-MB-231. The results of transfection experiments showed that the expression level of Linc00339 and cell viability were significantly up-regulated in the Linc00339 group compared with the pcDNA3.1 group. The overexpression of Linc00339 significantly increased the proliferation, adhesion and migration and invasion ability of MDA-MB-231 cells, as well as increased the volume and weight of tumor mass in tumor-bearing nude mice. Western blot results showed that Linc00339 overexpression can down-regulate APC protein expression and up-regulate Wnt/β-catenin signaling protein expression. Meanwhile, qRT-PCR results indicated Linc00339 overexpression can up-regulate miRNA-135b expression levels without affecting miRNA-135a and miRNA-138.Conclusions:This study demonstrated that Linc00339 may promote the development and progression of triple-negative breast cancer via the miR-135b/APC-mediated Wnt/β-catenin signaling pathway.

Objective To evaluate vitamin D status in healthy adults living in Guiyang. Method 1 500 healthy volunteers aged 20-79 years ( mean 45.2 years ) were recruited from a community in Guiyang by cluster sampling method. Questionnaires for living habits and fasting blood samples were collected from November, 2009 to February, 2010. Serum 25 ( OH ) D concentrations were measured by radioimmunoassay, using the DiaSorin kit,USA. Results The average serum 25 ( OH ) D level was ( 20. 4±9.0 ) ng/ml. The percentages of vitamin D deficiency [25 ( OH ) D ＜ 20 ng/ml], insufficiency [20 ng/ml ≤ 25 ( OH ) D ＜ 30 ng/ml], and sufficiency [25 ( OH ) D ≥ 30ng/ml] were 52. 3% , 32. 3% , and 15.4% , respectively. The 25 (OH) D concentrations in the young, middle-aged,and elderly were ( 18. 2±9. 2), (22. 8±8. 7), and ( 19. 9±7.8) ng/ml, respectively. The percentages of vitamin D deficiency in these groups were 62. 8%, 40. 2%, and 55.4%, being 61.6% in higher educational group ( ≥ 13 years) and 64. 4% in the group with lower body mass index ( ＜ 18.5 kg/m2 ). Conclusion Vitamin D deficiency is common in Guiyang including all age groups, especially among the youth and the elderly. Serum 25-hydroxyvitamin D level is also influenced by education, age, smoking, and other factors.