Objective:To investigate the value of flattening filter-free (FFF) mode in postoperative deep inspiration breath-hold (DIBH) intensigy-modulated radiotherapy for left breast cancer.Methods:A retrospective case series study was conducted. Clinical data of 21 patients with left breast cancer who underwent DIBH intensity-modulated radiotherapy after modified radical surgery in Meizhou People's Hospital from January 2021 to December 2022 were retrospectively analyzed. On the DIBH-mode CT of each patient, the 7-field intensity-modulation plan was designed using the plan developed in the 6 MV FFF-mode (FFF group) or the plan developed in the 6 MV flattening filter (FF)-mode (FF group). The target areas and organs at risk, dosimetric and biological parameters, and dose validation results were compared between the two plans.Results:Twenty-one patients were female with the age [ M ( Q1, Q3)] of 47 years old (32 years old, 61 years old). The percentage of target areas receiving 95% of the prescribed dose (V 95%) was (95.9±0.8)% and (95.7±1.9)% in the FF and FFF groups ( t = 2.98, P = 0.089), and the maximum dose was (5 401±251) cGy and (5 424±201) cGy ( t = 2.85, P = 0.181), the fitness indices were 0.88±0.05 and 0.87±0.06 ( t = 0.32, P = 0.562), the homogeneity indices were 1.06±0.01 and 1.07±0.02 ( t = 2.91, P = 0.009), the equivalent uniform doses (EUD) were (51.81±0.21) Gy and (51.97±0.20) Gy ( t = 0.51, P = 0.309), and the tumor control probability (TCP) was (99.68±0.01)% and (99.61±0.02)% ( t = 0.81, P = 0.560). The plans of the FFF group and the FF group were compliant, and the doses of all organs at risk to be irradiated were within the clinically acceptable range, and the radiation doses in the FFF group in the left lung [5 Gy irradiated volume (V 5 Gy), mean dose (D mean), EUD and normal tissue complication rate (NTCP)], right lung (V 5 Gy and D mean), heart (V 10 Gy, D mean, EUD and NTCP), and right breast (V 5 Gy, D mean and EUD) were differently lower than those in the FF group, and the differences were statistically significant (all P < 0.05). The monitor units in the FFF and FF groups were (984±132) MU and (751±145) MU ( t = -1.25, P < 0.001), and the total beam-on time was (1.4±0.3) min and (2.2±0.4) min ( t = 0.68, P < 0.001); individual field beam-on time was (12±7) s and (16±10) s ( t = 2.68, P = 0.001), and the beam-on time for each field in patients of the FFF group was less than 25 s; γ pass rates were (97.1±2.8)% and (97.6±2.1)% ( t = 0.59, P = 0.484). Conclusions:In the intensity-modulated radiotherapy of left breast cancer, the radiation dose of the energy to the critical organs in FFF mode is lower and has higher dose rate and shorter treatment time. FFF combined with DIBH technique has positive clinical significance in the intensity-modulated radiotherapy of breast cancer.

Objective To investigate the electrophysiological characteristics and clinical significance of unilateral tinnitus with normal hearing threshold.Methods A total of 34 patients with normal hearing but unilateral tinnitus admitted to our department from May 2022 to February 2023 were recruited as the study subjects.Pure tone hearing threshold detection,distortion product otoacoustic emission(DPOAE),auditory brainstem response(ABR)detection and extended high-frequency pure tone audiometry were performed on both ears(affected side and healthy side)of every patient.The data of the affected side group and those of healthy side group were compared.Results The Ⅰ-wave latency of ABR was significantly shorter(1.60 vs 1.73 ms,P=0.018),and its amplitude was obviously decreased(0.19 vs 0.23 μV,P=0.003)in the affected side group when compared with the healthy side group.In the affected group(34 ears),there were 18 ears(52.94％)having amplitude of wave Ⅲ greater than that of wave Ⅴ,while in the healthy group,no such difference in the amplitude between wave Ⅲ and wave Ⅴ was observed.There was statistical significance between the 2 groups(Chi-square=24.480,P＜0.001).In the 12.5,14.0,16.0,18.0 and 20.0 kHz conditions,the average hearing threshold of extended high-frequency audiometry was all significantly higher in the affected side group than the healthy group(P＜0.05).Conclusion For subjective tinnitus patients with normal hearing threshold,ABR examination is helpful in preliminarily determining whether there are hidden functional changes in the auditory pathway.Decreased Ⅰ-wave amplitude,shortened Ⅰ-wave latency,and wave Ⅲ amplitude greater than wave Ⅴ amplitude can be used as objective reference indicators.

Objective:To conduct a survey of the current status of education service offered to professional master's students in clinical medicine in a grade-A tertiary hospital in Chongqing, China based on the SERVQUAL model, and to discuss the problems with education service as well as measures for improvement.Methods:Based on the SERVQUAL model, a questionnaire consisting of 30 items in 5 dimensions was designed. Each item was rated for an expected score and a perceived score. Medical professional master's students in a Chongqing grade-A tertiary hospital in the first half year of 2022 were surveyed for the expected and perceived quality of education service to calculate service quality (SQ). SPSS 26.0 was used for reliability and validity analyses and descriptive statistical analyses. The results were analyzed using a two-dimensional quadrant graph.Results:A total of 263 valid questionnaires were returned, with an effective response rate of 97.77%. For both the expectation scale and the perception scale, the Cronbach's α values were >0.8, and the Kaiser-Meyer-Olkin values were >0.7, indicating good reliability and validity. The mean expected value of education service quality was 4.28, the mean perceived value was 3.96, and the mean gap value was -0.32. The SQ scores for all the items were negative, except for "provide neat suits for work". The two-dimensional quadrant analysis showed that 6 items were located in quadrant III (low-expectation and low-perception area), and 7 items were located in quadrant IV (high-expectation and low-perception area).Conclusions:The evaluation scale based on the SERVQUAL model can effectively reflect problems in postgraduate education for medical master's students, helping develop strategies to improve the quality of education service.

AIM: To establish a HPLC-QqQ-MS with multiple reaction monitoring (MRM) method for pharmacokinetics and tissue distribution study of ribavirin by oral and respiratory administration. METHODS: The experiment established a high-sensitivity LC-MS analytical method for the detection of ribavirin, and the linearity, specificity, recovery, accuracy, and precision were investigated. The established methods were used to investigate the pharmacokinetics and tissue distribution of the oral and respiratory administration methods. RESULTS: The concentration of drugs in the blood through respiratory tract administration is higher, and the drug absorption is faster. Respiratory tract administration C

OBJECTIVE：To study the anti-inflammatory effects of Yuyang capsule on bacterial dermatitis model rats and its effect on TLR/NF-κ B pathway. METHODS：Minimum inhibition concentration （MIC）and minimal bactericidal concentration （MBC）of Yuyang capsule against Staphylococcus aureus were determined by microdilution test. Totally 50 SD rats were randomly divided into model group ，positive control group （amoxicillin and clavulanate potassium ，120 mg/kg as amoxicillin ），Yuyang capsules high-dose ，medium-dose and low-dose groups （according to MIC ），with 10 rats in each group. The model of bacterial dermatitis was established by using the burned skin of rats infected with S. aureus . 24 h after modeling ，administration groups were intragastrically given the corresponding drug ，and model group was intragastrically given the same amount of normal saline ，once a day，for consecutive 7 days. The skin healing rate was calculated on the 1st，3rd，5th and 7th day of administration ，and the scab formation，decrustation and healing were recorded. The contents of IL- 1β，IL-6，IL-10，TNF-α，hydroxyproline（HYP），collagen Ⅰ（Col Ⅰ）and Col Ⅲ in skin tissue were detected by ELISA. Morphology changes of skin tissues were observed by HE staining. The ultrastructure was observed by transmission electron microscope. Protein expression of TLR 2，TLR4 and p-NF-κB p65 were detected by Western blotting assay. RESULTS ：MIC and MBC of Yuyang capsule were 25 mg/mL and 50 mg/mL，respectively. Dose of Yuyang capsules high-dose ，medium-dose and low-dose groups were set at 600，300，150 mg/kg. Compared with model group，scab appeared on the injured skin 3 days after administration in Yuyang capsule high-dose and medium-dose groups ，and decrustation appeared on the injured skin of part mice 5-7 days after administration ；the skin healing rate of the positive control group，Yuyang capsule high-dose and medium-dose groups were all significantly increased at each time point. The contents of IL- 1 β，IL-6，IL-10 and TNF-α，pathological score ，protein expression of TLR 2，TLR4 and p-NF-κB p65 were decreased significantly （P＜0.05 or P＜0.01）；the pathological changes such as inflammatory cell infiltration in skin tissue were improved. The contents of HYP，Col Ⅰ and Col Ⅲ were increased significantly in positive control group and Yuyang capsule high-dose group （P＜0.05 or P＜0.01）. There was no statistical significance in most above indexes in positive control group ，Yuyang capsule high-dose and medium-dose groups （P＞0.05）. CONCLUSIONS ：Yuyang capsule can promote skin healing of bacterial dermatitis model rats and shows certain anti-inflammatory effects ；the mechanism may be related to inhibiting TLR/NF-κB signaling pathway and reducing inflammatory response.

Liquid chromatography tandem mass spectrometry (LC-MS/MS) has gradually become a promising alternative to ligand binding assay for the bioanalysis of biotherapeutic molecules,due to its rapid method development and high accuracy.In this study,we established a new LC-MS/MS method for the determination of the anti-sclerostin monoclonal antibody (SHR-1222) in cynomolgus monkey serum,and compared it to a previous electrochemiluminescence method.The antibody was quantified by detecting the surrogate peptide obtained by trypsin digestion.The surrogate peptide was carefully selected by investigating its uniqueness,stability and MS response.The quantitative range of the pro-posed method was 2.00-500 μg/mL,and this verified method was successfully applied to the tox-icokinetic assessment of SHR-1222 in cynomolgus monkey serum.It was found that the concentrations of SHR-1222 in cynomolgus monkeys displayed an excellent agreement between the LC-MS/MS and electrochemiluminescence methods (ratios of drug exposure,0.8-1.0).Notably,two monkeys in the 60 mg/kg dose group had abnormal profiles with a low detection value of SHR-1222 in their individual sample.Combining the high-level anti-drug antibodies (ADAs) in these samples and the consistent quantitative results of the two methods,we found that the decreased concentration of SHR-1222 was due to the accelerated clearance mediated by ADAs rather than the interference of ADAs to the detection platform.Taken together,we successfully developed an accurate,efficient and cost-effective LC-MS/MS method for the quantification of SHR-1222 in serum samples,which could serve as a powerful tool to improve the preclinical development of antibody drugs.

Objective:To investigate setup errors of two fixation methods of transparent head pillow and vacuum bag head pillow in patients with head and neck tumors when undergoing radiotherapy.Methods:A total of 40 patients with head and neck tumors undergoing radiotherapy admitted to Meizhou People's Hospital of Guangdong Province from January 2017 to December 2018 were selected and randomly divided into the control group (transparent head pillow fixation) and the research group (vacuum bag head pillow fixation), with 20 cases in each group. Kilovoltage cone-beam computed tomography (CBCT) was used to obtain the registration image data of each patient for 10 times during the linear accelerator treatment. The linear and rotational positioning errors of two groups were also analyzed.Results:The linear setup errors in the direction of left-right (X-axis), head-foot (Y-axis) and front-back (Z-axis) were (1.1±0.8) mm, (0.9±0.8) mm and (1.2±0.9) mm in the study group, and (1.3±1.1) mm, (1.1±1.1) mm and (1.4±1.1) mm in the control group. The rotation setup error of X-axis, Y-axis, Z-axis was (0.73±0.52) °, (1.08±0.89) ° and (0.89±0.74) °, respectively in the study group, and (0.81±0.69) °, (1.38±1.05) °, (0.88±0.70) °, respectively in the control group. The difference of linear setup error in Y-axis and Z-axis was statistically significant ( P = 0.016, P = 0.004). The difference of rotation setup error in X-axis and Y-axis was statistically significant ( P = 0.036, P = 0.001). Conclusion:The vacuum pillow is better than the transparent pillow in improving the rotation error and linear error for patients with head and neck tumors undergoing radiotherapy.

ObjectiveTo investigate the clinical value of indocyanine green retention rate at 15 minutes (ICG-R15), Child-Turcotte-Pugh (CTP) class, and Model for End-Stage Liver Disease (MELD) score in predicting post-transjugular intrahepatic portosystemic shunt (TIPS) hepatic encephalopathy (HE) in liver cancer patients with portal hypertension. MethodsA retrospective analysis was performed for the clinical data of 95 liver cancer patients with portal hypertension who underwent TIPS in Department of Interventional Therapy in Beijing Shijitan Hospital from January 2015 to June 2017, and according to the presence or absence of HE after TIPS, they were divided into HE group with 24 patients and non-HE group with 71 patients. ICG-R15, CTP class, and MELD score were determined for all patients before surgery. The t-test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test and the Fisher’s exact test were used for comparison of categorical data between two groups. Univariate and multivariate logistic regression analyses were used to investigate the risk factors for HE after TIPS, and the receiver operating characteristic (ROC) curve was used to analyze the value of ICG-R15, CTP class, and MELD score in predicting HE. ResultsThe incidence rate of HE was 25.2% (24/95) within 12 months after TIPS. The univariate analysis showed that stent location (P=0.021), ICG-R15 (P=0.005), and CTP class (P=0.040) were associated with HE after TIPS. The multivariate analysis showed that stent located in the right portal vein (OR=3.373, 95% CI: 2.346~5.103, P=0.010) and ICG-R15＞30% (OR=2.107, 95% CI: 1.331~3.212, P=0.036) were independent risk factors for HE after TIPS in liver cancer patients with portal hypertension. The ROC curve analysis showed that ICG-R15, MELD score, and CTP class had an area under the ROC curve of 0.659, 0.638, and 0.621, respectively, in predicting HE after TIPS. ConclusionICG-R15 has a certain clinical value in predicting HE after TIPS in liver cancer patients with portal hypertension.

In recent years, the prevalence rate of nonalcoholic fatty liver disease (NAFLD) has increased significantly and NAFLD has gradually become one of the common chronic liver diseases in China. Patients with NAFLD-related end-stage or deteriorative liver diseases have become one of the main populations for liver transplantation. The increasing prevalence rate of NAFLD and the severe outcomes of nonalcoholic steatohepatitis (NASH) make it necessary to use effective methods to identify NAFLD. Therefore, this article summarizes the current serological methods for the diagnosis of NAFLD, including steatosis, NASH, and liver fibrosis, and discusses their advantages and disadvantages. Although most of the serum markers have limited clinical value, serum marker models have a good application prospect in the diagnosis of hepatic steatosis, the evaluation of fibrosis degree, and preliminary screening. Since a combination of different serological models can improve the accuracy of diagnosis, multi-angle and multicenter joint diagnosis will be a research hotspot in the future.

Objective To investigate the effect of miRNA-193b (miR-193b) up-regulation on the apoptosis,invasion and metastasis of hepatitis B virus (HBV)-positive hepatocellular cells.Methods HepG2.2.15cells were cultured until logarithmic growth phase and transfected with miR-193b mimic at a concentration of 25,50,100 pmol.The control group was transfected with blank mimic (0 pmol).After 48 hours,the expression of miR-193b in each group was detected by real-time quantitative polymerase chain reaction (qRT-PCR),the apoptosis rate in each group was detected by flow cytometry,the cell migration was detected by cell scratch assay,the cell invasion was detected by Transwell assay,and the expressions of Bax,Bcl-2,matrix metalloprotease (MMP)-9 and MMP-2 protein were detected by Western blotting.Results qRT-PCR results showed that the miR-193b expressions of miR-193b mimic (25,50 and 100 pmol) groups and control group in HepG2.2.15 cells were 1.05 ±0.09,1.53 ±0.12,2.08 ±0.17 and 0.49 ±0.12,and the difference was statistically significant (F =261.35,P ＜ 0.001).Compared with the control group,miR-193b expression significantly increased in each transfection group (P =0.036;P =0.029;P =0.022).Flow cytometry results showed the apoptosis rates of miR-193b mimic (25,50 and 100 pmol) groups and control group were (30.28 ±5.22) ％,(53.41 ±6.18)％,(79.89 ±7.13)％ and (1.02 ±0.13)％,and the difference was statistically significant (F =357.19,P ＜ 0.001).Compared with the control group,the apoptosis rate significantly increased in each transfection group (P =0.025;P =0.010;P =0.007).Cell scratch assay results showed that the migration distances of miR-193b mimic (25,50 and 100 pmol) groups and control group were (27.53 ± 1.54) mm,(19.24 ± 2.12) mm,(13.42 ± 1.53) mm and (34.95 ± 1.92) mm,and the difference was statistically significant (F =408.62,P ＜ 0.001).Compared with the control group,the migration distance significantly decreased in each transfection group (P =0.032;P =0.007;P =0.006).Transwell experimental results showed that the absorbance values of miR-193b mimic (25,50 and 100 pmol) groups and control group were 1.02 ±0.12,0.59 ±0.13,0.42 ±0.10 and 1.68 ±0.16,and the difference was statistically significant (F =511.68,P ＜ 0.001).Compared with the control group,the cell invasion ability significantly weakened in each transfection group (P =0.028;P =0.005;P =0.002).Western blotting results showed that the expressions of Bax,Bcl-2,MMP-9 and MMP-2 protein of miR-193b mimic (25,50 and 100 pmol) groups and control group had statistically significant difference (F =264.38,P ＜ 0.001;F =437.19,P ＜ 0.001;F =377.46,P ＜0.001;F =208.79,P ＜ 0.001).Further paired comparison showed that the expressions of Bax,Bcl-2,MMP-9 and MMP-2 protein between mimics groups and control group were statistically significant (all P ＜0.05).Conclusion miR-193b can induce the apoptosis and inhibit the invasion,metastasis of HBV-positive hepatoeellular cells,and the mechanism may be related to the regulation of Bax,Bcl-2,MMP-9 and MMP-2 protein expression.