Objective To establish a liquid chromatography method for the simultaneous determination of 13 aromatic amine compounds (AAs) in workplace air. Methods A total of 13 AAs in both vapor and aerosol phases were collected in workplace air using a new GDH-6 sampling tube. Samples were desorbed and eluted with methanol, separated using a Symmetry Shield™ RP₁₈ reversed-phase liquid chromatography column, and detected with a diode array detector. Quantification was performed using an external standard method. Results The linear range of the 13 AAs measured by this method was 0.02-373.60 μg/L with the correlation coefficients greater than 0.999 0. The minimum detection concentration was 0.09-14.37 μg/m³, and the minimum quantitative concentration was 0.31-47.90 μg/m³ (both calculated based on sampling 15.0 L of air and 3.0 mL of elution volume). The average desorption and elution efficiency ranged from 97.46% to 101.23%. The within-run relative standard deviation (RSD) was 0.10%-5.99%, and the between-run RSD was 0.17%-2.71%. Samples could be stably stored in sealed conditions at 2-8 ℃ for more than seven days. Conclusion This method is suitable for the simultaneous determination of 13 AAs in workplace air, including both vapor and aerosol phases.

BACKGROUND:Irreducible femoral neck fracture was difficult to obtain anatomic reduction.As a new type of internal fixation,the femoral neck system is still blank for the treatment of non-anatomical reduced femoral neck fractures. OBJECTIVE:To explore the biomechanical stability of femoral neck system internal fixation under nonanatomical reduction in the treatment of femoral neck fractures based on finite element analysis. METHODS:CT data of the hip joint of a healthy female adult were obtained.Anatomical reduction of femoral neck fracture models with Pauwels angles of 30°,50°,and 70° were established using Mimics 21.0,Geomagic Wrap 2021,and SolidWorks 2020.The fracture proximal ends of the three anatomical reduction models were shifted upward by 2 mm along the fracture line,and three positive buttress models with different Pauwels angles were obtained.In the same way,three negative buttress models were acquired by shifting downward by 2 mm.SolidWorks 2020 was used to make the femoral neck system internal fixation,and the nine femoral neck fracture models were assembled with the femoral neck system.Then Ansys 19.0 was used for finite element analysis.The displacement distribution and maximum displacement,stress distribution and maximum stress of the femur and femoral neck system were recorded under 2100 N stress. RESULTS AND CONCLUSION:(1)When Pauwels angles were 30°,50°,and 70°,the maximum stresses of the femoral neck system appeared to be concentrated at the junction of the sliding hip screw and anti-rotation screw.The maximum femur stresses appeared to be concentrated in the medial cortex of the femur.The maximum displacement was concentrated at the upper of the femoral head and femoral neck system.(2)When Pauwels angles were 30° and 50°,the maximum displacement and maximum stress of the femoral neck system and femur were:negative buttress>anatomical reduction>positive buttress.(3)When Pauwels angle was 70°,the maximum displacement and maximum stress of the femoral neck system were:negative buttress>anatomical reduction>positive buttress;the maximum displacement and maximum stress of the femur were:negative buttress>positive buttress>anatomical reduction.(4)With the increase of Pauwels angle,the biomechanical advantage of the positive buttress was weakening.However,it was better than a negative buttress.When Pauwels angle was 30°,positive buttress was more stable than anatomical reduction.When Pauwels angle was 50°,the biomechanical difference between positive buttress and anatomical reduction became smaller.When Pauwels angle was 70°,the stability of anatomical reduction was slightly better than positive buttress.(5)If it was difficult to achieve anatomical reduction of femoral neck fracture during operation,but the positive buttress had been displaced within 2 mm,the femoral neck system could be used to offer stable mechanical fixation.It is necessary to avoid negative buttress reduction.

ObjectiveTo establish a method for the determination of 1,1,1,2-tetrachloroethane (TeCA) and 1,1,2,2-TeCA in human urine using liquid-liquid extraction-gas chromatography. Methods The 5.0 mL urine sample was mixed with 2.0 g anhydrous sodium sulfate and 5.0 mL ethyl acetate, then vortexed mixing. The 1.0 mL extraction was separated by 100% dimethylpolysiloxane capillary gas chromatography column, detected by flame ionization detector, and quantified by an external standard method. Results The linear ranges of 1,1,1,2-TeCA and 1,1,2,2-TeCA were 0.250-50.750 mg/L, with both correlation coefficients of >0.999 9. The detection limit of 1,1,1,2-TeCA in urine was 0.020 mg/L, and the lower limit of quantification was 0.060 mg/L. The average recovery was 88.02%-101.32%, and the within-run and between-run relative standard deviations (RSDs) were 0.11%-0.47% and 0.39%-1.09%, respectively. The detection limit of 1,1,2,2-TeCA in urine was 0.050 mg/L, and the lower limit of quantification was 0.150 mg/L. The average recovery was 93.42%-101.32%, and the within-run and between-run RSDs were 0.28%-1.04% and 0.50%-1.03%, respectively. Both the 1,1,1,2-TeCA and 1,1,2,2-TeCA cannot be stored at room temperature. The 1,1,2,2-TeCA can be stored at 4 ℃ for at least three days. At -20 ℃, the 1,1,1,2-TeCA can only be stored for one day, while 1,1,2,2-TeCA can be stored for at least five days. Conclusion This method has high sensitivity, good specificity, simple sample pretreatment, and more intuitive and reliable results. It can be used to determine the level of 1,1,1,2-TeCA and 1,1,2,2-TeCA in urine of occupational population.

OBJECTIVE To construct a clinical model of motion sickness(MS),provide a relatively objective diagnostic model for MS research,and provide a basis for further clinical intervention of the disease.METHODS A total of 60 subjects were included and divided into experimental group and control group according to the presence or absence of MS.The MS clinical model was established using SRM-IV rotating chair.Peripheral blood was collected before and after acceleration exposure,and the contents of adrenocorticotropic hormone(ACTH),growth hormone(GH),prolactin(PRL),follicle stimulating hormone(FSH),luteinizing hormone(LH),thyroid stimulating hormone(TRH)and gastrin-17(G-17),acetylcholine(ACH)and 5-hydroxytryptamine(5-HT)were detected,Graybiel scale was used to evaluate the severity of MS.The correlation between MS symptoms and signs and peripheral blood indexes was analyzed by multiple linear regression,and the diagnostic model was established.construct a clinical model of MS and a diagnostic model based on blood parameters,so as to provide a reliable clinical model and an objective diagnostic model for MS research,and to provide a basis for further clinical intervention of the disease.RESULTS After acceleration exposure,the Graybiel scores,ACH,5-HT,ACTH,GH and PRL levels in peripheral blood of the experimental group were higher than those before exposure,and were significantly different from those of the control group(P<0.001).There was no significant difference in FSH,LH,TRH and G-17 between the two groups before and after acceleration exposure(P>0.05).Multi-index combined diagnostic model:Graybiel scores=-9.32+0.131×ACTH+0.055×ACH+0.041×5-HT.CONCLUSION The levels of ACH,5-HT,ACTH,GH and PRL increased during the onset of MS.The multi-index combined diagnosis model can provide a certain basis for the objective diagnosis of MS in clinical practice.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Aromatic amine compounds are diverse, widely used, and highly toxic. They mainly exist in aerosol and vapor in workplace air. Occupational poisoning incidents caused by aromatic amine compounds occur from time to time. In China, occupational exposure limits have been established for only 11 aromatic amine compounds, with supporting detection methods developed only for four compounds： aniline, N-methylaniline, N,N-dimethylaniline, and p-nitroaniline. Most of the highly toxic and hazardous aromatic amine compounds do not have specific limit. Currently, regular sampling mediums for detecting aromatic amine compounds in the workplace air are absorbing solution, filter membrane, silica gel, and poly(styrene-divinylbenzene) resin. Regular detection methods are gas chromatography, liquid chromatography, fluorescence detection, and chromatography-mass spectrometry. However, these methods are mostly designed for detecting individual compounds or their specific forms, and there is a need to develop a detection method that can detect aromatic amine compounds existing in aerosol and vapor form simultaneously using a novel composite sampling tube.

Objective To establish a high performance liquid chromatography (HPLC) method for simultaneous determination of six aniline compounds (ADs) in workplace air. Methods GDH-1 air sampling tube was used to collect six co-existing ADs such as aniline, o-toluidine, N-methylaniline, m-methylaniline, p-methylaniline and N,N-dimethylaniline in the vapor and aerosol of workplace air. The samples were desorbed and eluted using a methanol solution containing 1.00% ammonia water, followed by separation on a C₁₈ chromatographic column and detection using a diode array detector. Results The quantification range of the method was 0.19 -253.50 mg/L, with the correlation coefficient of 0.999 9 for all six ADs. The minimum detection range was 0.02-0.06 mg/m³, and the minimum quantitation range was 0.04-0.19 mg/m³ [both calculated for a 15.0 L sample with a desorption (elution) solution volume of 3.00 mL]. The average desorption and elution efficiencies were 92.15%-104.41% (silica gel) and 94.29%-104.29% (filter membrane). The intra-assay relative standard deviation (RSD) ranged from 0.90%-9.72% (silica gel) and 0.57%-6.96% (filter membrane). The inter-assay RSD ranged from 2.03%-9.78% (silica gel) and 2.50%-8.62% (filter membrane). The samples were stable at room temperature for seven days. Conclusion This method can be used for the simultaneous determination of six ADs in workplace air.

The number of dental schools increased from 55 in 2000 to 66 in 2019 in the United States. The number of public, private, and private-state-related dental schools were 40, 22 and 4, respectively. A majority of them were located in most developed areas, such as western, eastern, and southern regions of the country. In the same period, the number of freshman enrollees rose from 4 234 to 6 231 while the average of enrollees kept under 100. On the basis of learning relevant experiences of the United States, it might be necessary for China to expand the overall scale of stomatology education in order to address the shortage of dentists, take measures to increase the number of stomatology schools and improve their distribution, and control the number of enrollees per school to enhance the quality of education.

Oral cancer has a high degree of malignancy, easily recurs, readily metastasizes and poor progonsis. Autophagy is a catabolic process induced in cells under stressful conditions. In recent years, studies have found that the activation of autophagy in epithelial cells can inhibit carcinogenesis and activate pathways such as mTOR and MAPK to activate autophagy in oral cancer cells and inhibit their survival. Inducing autophagy can degrade eukaryotic initiation factor 4E protein and inhibit oral cancer metastasis. Inducing autophagy in oral cancer cells can inhibit their proliferation and promote their apoptosis. Adding autophagy inducers to the treatment can help improve its efficacy and patient survival compared with chemoradiotherapy alone. In addition, the induction of autophagy in oral cancer cells can improve the body's immune function and enhance the efficacy of oral cancer immunotherapy. This article summarizes the relationship between autophagy and oral cancer and the role of induced autophagy in the treatment of oral cancer with the combined application of chemoradiotherapy and immunotherapy. The goal is to provide new ideas for inducing autophagy during the treatment of oral cancer, improving the therapeutic effect of oral cancer and the survival rate of patients. At present, the mechanism of action of induced autophagy in the treatment of oral cancer is not clear. Future research should study its mechanism of action, improve its therapeutic effect on oral cancer and develop autophagy inducers to accurately regulate and induce autophagy during the treatment of oral cancer.

Objective:To explore the application value of the new gastric cancer screening scoring system for risk populations in the island of Fujian province.Methods:From April to June 2019, gastric cancer screening was performed on the population of Nanri Island, Putian City, Fujian Province, and epidemiological data of all subjects were prospectively collected. Participants underwent gastroscopy based on gastric cancer risk stratification of the new scoring system. Suspected positive cases further received magnifying endoscopy and biopsy. Additional endoscopic procedures and other surgical treatments were conducted. The detection rates of gastric cancer and precancerous lesions in each group of gastric cancer risk stratification were compared, and the Chi-square test was used for statistical analysis.Results:A total of 1 423 subjects were included, and 19 cases (1.34%) of gastric cancer were detected. The detection rates of gastric cancer were 0.88% (9/1 025) in the low-risk group, 1.76% (6/341) in the medium-risk group, and 7.02% (4/57) in the high-risk group. Paired comparison between the low-risk group and the high-risk group showed significant difference ( χ2=12.364, P=0.003). There was no significant difference between the low-risk group and medium-risk group, or between the medium-risk group and high-risk group ( P>0.05). Among all participants, 87 (6.11%) cases of gastric precancerous lesions were identified. The detection rates of precancerous lesions in the low-risk, medium-risk, and high-risk groups were 6.24% (64/1 025), 5.87% (20/341), and 5.26% (3/57) respectively, with no significant difference among the three groups ( P>0.05) .Conclusion:During gastric cancer screening, the novel gastric cancer screening scoring system helps to stratify gastric cancer risk for population in the islands of Fujian province, serving as a foundation for subsequent detailed endoscopy.