To establish a simple and sensitive LC-MS/MS method for simultaneous determination of the concentration for L-tryptophan(L-Try)and L-kynurenine(L-Kyn)in rat plasma. The changesin the process of the liver tumors formation may provide a basis for the diagnosis of liver cancer. 3-Nitro-L-tyrosine(3-NT)were added as the internal standard for the determination of two active substances and the chromatographic analysis was performed on a RRHD Eclipse Plus C18 column(3. 0 mm×100 mm, 1. 8 μm). The mobile phase was composed of water and acetonitrile(containing 0. 1%formic acid)(90 ∶10)at a flow rate of 0. 25 mL/min, and the injection volume is 5 μL. Detection and quantification were performed by mass spectrometry in multiple reaction monitoring mode with m/z 205. 12→146. 10(L-Try), m/z 209. 09 →146. 10(L-Kyn), m/z 227. 09→181. 10(3-NT), respectively. The results show that thelinear ranges were 9. 670-9 670 ng/mL for L-Try, and 9. 973-9973 ng/mL for L-Kyn(r2≥0. 9990). The limit of quantitation were 9. 670 ng/mL for L-Try, and 9. 973 ng/mL for L-Kyn, respectively. The intra- and inter-day precisions were all less than15%; the recoveries ofthe two analytes were more than 81. 17% and severe matrix effect was not observed. The ratio of L-Try/L-Kyn determined by LC-MS/MS in rat plasma showed an overall downward trend, which could used effectively for the drug metabolism studies and researches on the action mechanism of medicine on liver cancer. A rapid, simple, sensitive and specific LC-MS/MS method has been successfully developed and could also be used effectively for the drug metabolism studies and researches on the action mechanism of medicine on liver cancer.

Objective:To conduct a survey on major surgeon′s mental trauma caused by iatrogenic biliary injury (IBI) during laparoscopic cholecystectomy (LC), and explore its influencing factors.Methods:The retrospective cross-sectional survey was conducted. Surgeons who have registered in Chinese College of Surgeons of Chinese Medical Doctor Association and Chinese Surgical Society of Chinese Medical Association were recruited to participate as respondents between December 1, 2018 and January 1, 2019. The survey was conducted by the questionnaires of influencing factors for surgeon′s mental trauma caused by IBI during LC. The questionnaires were distributed to participants via WeChat on the Wenjuanxin platform. Observation indicators: (1) results of questionnaire survey; (2) analysis of influencing factors for severe mental trauma of major surgeons caused by IBI during LC. Measurement data with normal distribution were expressed as Mean± SD, and count data were expressed as absolute numbers or percentages. The chi-square test was used for univariate analysis. Factors with P<0.10 in the univariate analysis were included in multivariate analysis, and Logistic regression model was used for multivariate analysis. Results:(1) Results of questionnaire survey. A total of 606 questionnaires were retrieved. ① Basic information of major surgeons: of the 606 major surgeons, there were 596 males and 10 females, aged (41±7)years, with a range from 18 to 62 years. Of the 606 major surgeons, 59.24%(359/606) came from non-teaching hospitals, and 64.03%(388/606) encounted the most impressive case of IBI during LC when they were in the primary or intermediate professional title. For 76.24%(462/606) of the major surgeons, the first case of IBI during LC was the most impressive case, and 69.80%(423/606) believed that careful operation during LC could avoid IBI. ② Patient information: of the patients with the most impressive IBI during LC in each major surgeon′s memory, there were 400 females and 206 males. The proportion of patients younger than 35 years old, in 35-65 years old and older than 65 years old was 9.57%(58/606), 65.51%(397/606), and 24.92%(151/606), respectively. ③ IBI related information: 57.43%(348/606) of the major surgeons indicated that they could receive help from senior surgeons in time for the occurrence of IBI during LC, and 78.88%(478/606) of the major surgeons invited senior surgeons to participate in the initial repair. For the most impressive case of IBI during LC, 66.83%(405/606) of the primary repair surgeries were performed during LC, 11.06%(67/606) were performed within postoperative 3 days and 22.11%(134/606) were performed after 3 days. The main repair methods included local repair, bile duct to end anastomosis, and bilioenteric anastomosis, accounting for 24.92%(151/606), 30.20%(183/606), 33.17%(201/606), respectively. The proportion of patients requiring partial hepatectomy, with perioperative death, and requiring multiple repair was 2.48%(15/606), 2.15%(13/606), and 9.24%(56/606), respectively. ④ Subsequent processing on major surgeons: after the occurrence of IBI during LC, 64.85%(393/606) of the major surgeons gained the understanding of patients and their families, 35.15%(213/606) of the major surgeons were involved in medical disputes, 15.68%(95/606) of the major surgeons received administrative punishment from the hospital. About the compensation, 14.36%(87/606) of the major surgeons had to pay for the compensation by themselves, and only 6.77%(41/606) of the major surgeons had medical liability insurance. There were 9.24%(56/606) of the major surgeons invloved in violent conflicts during the medical disputes. ⑤ Psychology-related information of major surgeons: of the 606 major surgeons, 544 had mental trauma including 279 with severe mental trauma. After the occurrence of IBI during LC, 82.01%(497/606) of the major surgeons experienced anxiety and/or depression for more than one month; 63.37%(384/606) of the major surgeons expected to avoid LC or showed tension during LC; 44.72%(271/606) of the major surgeons had a physiological response when recalling the case; 36.14%(219/606) of the major surgeons initiated the idea of not being a surgeon; 6.44%(39/606) of the major surgeons asked psychologists for help; and 5.61%(34/606) of the major surgeons had taken psychiatric drugs such as antianxiety and anti-depression drugs for more than one month. (2) Analysis of influencing factors for severe mental trauma of major surgeons caused by IBI during LC. Results of univariate analysis showed that the hospital type of the major surgeons, participation of senior surgeons in the repair, surgical method of the primary repair, IBI requiring repeated repair, medical disputes, administrative punishment from the hospital, compensation paid by the major surgeon, having medical liability insurance, violent conflicts in medical disputes were related factors for severe mental trauma of the major surgeons caused by IBI during LC ( χ2=7.688, 3.932, 19.764, 13.837, 61.488, 24.904, 30.976, 5.344, 26.285, P<0.05) . Results of multivariate analysis showed that the surgical method of the primary repair, IBI requiring repeated repair, medical disputes, administrative punishment from the hospital, compensation paid by the major surgeon, violent conflicts in medical disputes were independent risk factors for severe mental trauma caused by IBI during LC of the major surgeons ( odds ratios=1.203, 2.198, 2.922, 1.830, 2.405, 2.171, 95% confidence interval: 1.033-1.402, 1.143-4.226, 1.944-4.391, 1.083-3.093, 1.076-5.375, 1.002-4.702, P<0.05). Having medical liability insurance was an independent protective factor for severe mental trauma of the major surgeons caused by IBI during LC ( odds ratios=0.336, 95% confidence interval: 0.126-0.896, P<0.05). Conclusions:Most surgeons in China are troubled by IBI during LC, and nearly half of them suffer from severe mental trauma. Surgical method of the primary repair, IBI requiring repeated repair, medical disputes, administartive punishment from the hospital, compensation paid by the major surgeon, and violent conflicts in medical disputes are independent risk factors for severe mental trauma of major surgeons caused by IBI during LC. Having medical liability insurance is an independent protective factor for severe mental trauma of major surgeons caused by IBI during LC.

In order to reduce the impact caused by the contact between the foot and the ground when wearing the lower extremity exoskeleton under the condition of high load, this paper proposed an exoskeleton foot mechanism for improving the foot comfort, and optimized the key index of its influence on the comfort. Firstly, the physical model of foot mechanism was established based on the characteristics of foot stress in gait period, and then the mathematical model of vibration was abstracted. The correctness of the model was verified by the finite element analysis software ANSYS. Then, this paper analyzed the influence of vibration parameters on absolute transmissibility based on vibration mathematical model, and optimized vibration parameters with MATLAB genetic algorithm toolbox. Finally, this paper took white noise to simulate the road elevation as the vibration input, and used the visual simulation tool Simulink in MATLAB and the vibration equation to construct the acceleration simulation model, and then calculated the vibration weighted root mean square acceleration value of the foot. The results of this study show that this foot comfort mechanism can meet the comfort indexes of vibration absorption and plantar pressure, and this paper provides a relatively complete method for the design of exoskeleton foot mechanism, which has reference significance for the design of other exoskeleton foot and ankle joint rehabilitation mechanism.
Acceleration ; Ankle Joint ; Biomechanical Phenomena ; Exoskeleton Device ; Finite Element Analysis ; Foot ; Gait ; Humans ; Lower Extremity ; Models, Theoretical ; Vibration

Objective: To investigate the expression of trophoblast cell-surface antigen 2 (TROP2) in salivary adenoid cystic carcinoma (SACC) in order to analyze its relationship with TROP2 expression and clinicopathological features, as well as to clarify the correlation between TROP2 expression and the prognosis of patients with SACC. Methods: With approval from the ethics committee, the expression of TROP2 in 85 SACC and paracancer tissue samples was detected by using the immunohistochemical method, and the relationship between TROP2 expression and clinicopathological characteristics was analyzed. The Kaplan-Meier method was used to analyze the relationship between TROP2 protein expression and 5-year disease-free survival (DFS) in 40 patients with SACC. Furthermore, the logistic regression model was used to analyze the prognostic factors of patients with SACC. Results: The low or no expression rate of TROP2 in SACC tissues was significantly higher than that in paracancer tissues (P<0.001). Low or no expression of TROP2 was significantly positively correlated with tumor growth and clinical staging in patients with SACC (P<0.05). Kaplan-Meier survival analysis showed that the DFS of patients with SACC with low or no expression of TROP2 protein was significantly lower than those of patients with high expression of TROP2 protein (P<0.05), and the prognosis was poor. The logistic regression model showed that low or no expression of TROP2 protein (OR = 5.37; 95% CI: 1.03-28.08; P = 0.046) and Ⅲ-Ⅳ clinical staging (OR = 6.89; 95%CI: 1.37~34.77; P = 0.019) were risk factors affecting the prognosis of patients with SACC. Conclusion Low or no expression of TROP2 protein in SACC tissues leads to poor prognosis of patients and is positively correlated with tumor growth and clinical staging. In addition, low or no expression of TROP2 can be used as an independent prognostic risk factor for poor prognosis in patients with SACC, and TROP2 is a marker of poor prognosis in patients with SACC.

Oleanolic acid (OA), a pentacyclic triterpenoid, exhibits a broad spectrum of biological activities, including antitumor, antiviral, antibacterial, anti-inflammatory, hepatoprotective, hypoglycemic, and hypolipidemic effects. Since its initial isolation and identification, numerous studies have reported on the structural modifications and pharmacological activities of OA and its derivatives. Despite this, there has been a dearth of comprehensive reviews in the past two decades, leading to challenges in subsequent research on OA. Based on the main biological activities of OA, this paper comprehensively summarized the modification strategies and structure-activity relationships (SARs) of OA and its derivatives to provide valuable reference for future investigations into OA.
Oleanolic Acid ; Structure-Activity Relationship ; Anti-Inflammatory Agents/pharmacology* ; Triterpenes ; Anti-Bacterial Agents/pharmacology*