Objective:To evaluate the efficacy and safety of upadacitinib in the real-world treatment of difficult-to-treat Crohn's disease (DTT-CD) .Methods:This multicenter, retrospective cohort study included patients diagnosed with DTT-CD according to the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) criteria, and treated at eight Chinese inflammatory bowel disease centers between January 2023 and March 2025. Clinical outcomes were assessed after 12 weeks of induction therapy with upadacitinib (45 mg qd), including clinical remission rate, clinical response rate, and incidence of adverse events.Results:Among 151 enrolled DTT-CD patients, the clinical remission rate was 47.0%, and the clinical response rate was 90.7% after 12 weeks of treatment. Adverse events occurred in 42 cases (27.8%) .Conclusion:Upadacitinib demonstrated favorable efficacy in inducing clinical remission in DTT-CD patients, with a good safety profile at the induction dose (45 mg qd) .

Objective To establishing a chromatographic analysis method for therapeutic drug monitoring of fruquintinib by high-performance liquid chromatography （HPLC）. Methods The analysis was conducted using a Welch Ultimate XB-C₁₈ （4.6 mm×150 mm, 5 μm） column with the column temperature at 35℃. The flow rate was 1.0 ml/min and the detection wavelength was at 240 nm. The mobile phase consisted of acetonitrile and 10 mmol/L potassium dihydrogen phosphate （pH 3.15）= 40∶60（V∶V）. The internal standard substance was Apatinib．All plasma samples were extracted with ethyl acetate solution. Results The linearity of Fruquintinib in plasma was good within the range of 15.63-500.00 ng/ml （r=0.999 9）. The recoveries of the method were between 95%-110% with the RSD less than 10%. The extraction rates of the method were all higher than 97%. The stability tests met the relative requirements. Conclusion A HPLC method for the determination of Fruquintinib in human plasma was established. The method had good specialty, and could be used to detect the blood concentrations of Fruquintinib in clinical practice to improve the individualized medication．

Objective:To evaluate the efficacy and safety of upadacitinib in the real-world treatment of difficult-to-treat Crohn's disease (DTT-CD) .Methods:This multicenter, retrospective cohort study included patients diagnosed with DTT-CD according to the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) criteria, and treated at eight Chinese inflammatory bowel disease centers between January 2023 and March 2025. Clinical outcomes were assessed after 12 weeks of induction therapy with upadacitinib (45 mg qd), including clinical remission rate, clinical response rate, and incidence of adverse events.Results:Among 151 enrolled DTT-CD patients, the clinical remission rate was 47.0%, and the clinical response rate was 90.7% after 12 weeks of treatment. Adverse events occurred in 42 cases (27.8%) .Conclusion:Upadacitinib demonstrated favorable efficacy in inducing clinical remission in DTT-CD patients, with a good safety profile at the induction dose (45 mg qd) .

OBJECTIVE：To analyze the mass spectrometry fragmentation regularity of bicyclol ，bifendate and schisandrin C ， and to identify the impurities of bicyclol raw material. METHODS ：UHPLC-ESI-Q-TOF-MS method was adopted. Using electrospray ionization source ，in positive ion mode ，the excimer ion and characteristic fragments of bicyclol ，bifendate and schisandrin C were analyzed by means of TOF-MS. According to the mass change of fragments ，the possible fragmentation pathways were speculated ，and the fragmentation regularity were analyzed and summarized. Bicyclol raw material sample was first separated by liquid chromatography to find the impurity peaks in it ，and then the impurity peaks were analyzed by mass spectrometer；the impurity identification was conducted by combining with the fragmentation regularity. RESULTS ：The 3 compounds all produced [M+H] + excimer ion in the positive ion mode. After collision-induced dissociation ，the C-O bond ，the simple rupture of the C-C bond and the ring-opening cleavage of the oxygen ring occurred ；with the loss of neutral fragments ， mainly CH 2O，supplemented by CO 2，CO and CHO ，the dissociation was concentrated in the middle and high quality regions. C-C and C-O bonds of 3 compounds were simply broken only in the branched chain structure and/or oxygen ring structure ，but the structure of the biphenyl parent nucleus remained unchanged. Among them ，the bicyclol contained a benzyl alcohol structure ，so under acidic mobile phase conditions ，it would exist stably in the form of [M+H －H2O]+. Because schisandrin C contained 8-membered ring structure，ring opening first occurred under collision voltage ，and then neutral fragment loss occurred. The secondary mass spectra of impurity in bicyclol raw material were consistent with the mass spectra fragmentation of secondary fragments of bifendate. CONCLUSIONS：The study summarized mass spectrometry fragmentation regularity of 3 schisandrin derivatives. The impurity in bicyclol raw material may be bifendate.

OBJECTIVE：To establish a method for concentration determination of anlotinib in human plasma and apply it in the clinic. METHODS ：The plasma samples were pretreated by salting-out assisted with liquid-liquid extraction with ammonium acetate as salting out assistant and acetonitrile as solvent. Using voriconazole as internal standard ，LC-MS/MS method was adopted. The separation was performed on Waters X Bridge C 18 column with mobile phase consisting of 0.2％ formic acid solution- acetonitrile（gradient elution ）at the flow rate of 1 mL/min. The column temperature was set at 40 ℃，and sample size was 10 μL. The split ratio was 3∶7. The electrospray ion source and multiple reaction monitoring mode were used for the analysis. The ion pair of anlotinib and internal standard under positive ion mode were m/z 408.3→339.3 and m/z 350.2→281.3，respectively. RESULTS ： Anlotinib showed a good linear relationship in the concentration range of 0.2-200 ng/mL（R2＞0.996 7）. The lowest limit of quantitation was 0.2 ng/mL. Intra-day and inter-day RSDs were no more than 12％ （n＝6 or n＝3）. Accuracies were 90.92％-108.00％（n＝6 or n＝3）. The average extraction recoveries were 87.51％-100.00％（RSD＜8％，n＝6）. The average matrix effects were 96.66％-99.93％（RSD＜5％，n＝6）. The plasma concentration of 3 patients with NSCLC treated with anlotinib was 8.74-65.60 ng/mL. CONCLUSIONS ：The method is simple ，accurate and specific ，and is suitable for the plasma concentration monitoring of anlotinib in NSCLC patients.

Folate is a water-soluble vitamin that cannot be synthesized by the body itself and must be obtained by external supplementation.There is substantial evidence that folate deficiency causes neural tube defects, partial birth defects, dementia, and certain types of cancer.However, excessive supplementation of folic acid(FA), the main form of supplementation at present, will increase the potential risk of certain diseases for oneself and future generations.Therefore, it is of great significance to explore new supplementation methods for folate supplementation in the population.This paper will discuss the progress of 5-methyltetrahydrofolate(5-MTHF)supplementation and the feasibility of replacing the chemical folic acid in terms of toxicology, bioavailability, vitamin B12 coverup, single nucleotide polymorphisms of folate metabolism-related enzyme genes, and fortification effect.