OBJECTIVETo establish a method for determination of 2,5-hexanedione in urine by headspace solid-phase microextraction-gas chromatography.

METHODSAfter extraction by solid-phase microextraction head, 2,5-hexanedione in urine was determined by gas chromatography and was quantified by external standard method.

RESULTSThe concentration of 2,5-hexanedione in urine showed a linear relationship within the range of 0.1-20.0 µg/ml. The regression equation was y=261.36x-1.903 3, r=0.999 2. The minimum detectable concentration was 0.01 µg/ml. The recovery rate was 92.6%-97.1%, with a relative standard deviation (RSD) of 3.3%-5.8%. The intra-day and inter-day RSDs were 3.8%-6.2% and 4.7%-6.3% respectively.

CONCLUSIONThis determination method has no requirement for organic solvents, features simple and rapid operation, possesses higher detection sensitivity, and applies well to the determination of 2,5-hexanedione in urine.

Objective: To establish a method for the determination of diethyl phthalate by gas chromatography in the air of workplaces. Methods: Diethyl phthalate in the air of workplace was collected throμgh glass fiber filter, eluted with methylbenzene, and detected by gas chromatography coupled with FID detectors. Results: The linear range of diethyl phthalate determined by this method was 14.0~1 400 μg/ml, y=2.09801x-3.66229, and the coefficient correlation was 0.999 99. The detection limit was 1.10 μg/ml, and the minimum detection concentration was 0.18mg/m³ (collected sample volume was 30 L) . The within-run precisions were 1.04%~2.75%, and the between-run precisions were 0.34%~1.30%. The recovery rates were 98.72%~103.21%, and sampling efficiency was 97.2%~100.0%. The elution efficiencies were 97.25%~98.68%. The samples could be stored at room temperature for 15 days. Conclusion The indicators established in this study were conformed with the requirements of GBZ/T210.4-2008, "The Guidelines for the Development of Occupational Hygiene Standards Methods Part 4: Determination of Chemical Substances in the Air of Workplaces" . Diethyl phthalate in the workplace air could be rapidly collected, accurate separated and determinated. This method is applicable to the determination of diethyl phthalate in the workplace air.

Objective: To establish a practical method forsampling and detectingtributyl phosphate intheworkplace. Methods: The samples were extracted by glass fiber membrane, eluted with ether, separated by gas chromatography, and detected by flame photometric detector. Results: There were good linear relationship in the minimum detection concentration was 7.2-720.0 μg/ml, and the correlation coefficient was 0.999 92. The detection limit was 0.86 μg/ml, and the minimum detection concentration was 0.14 mg/m³ (sample volume was 30 L) . Recovery rates were 99.8%-100.2%. The with-in relative standard deviations were 4.0%-5.4% and the between relative standard deviations were 2.0%-5.5%, and average samplingefficiency was about 99.1%-100.0%. Conclusion This method conforms with the requirements of "Standardization of Methods for Determination of Toxic Substance in Workplace" . Tributyl phosphate in air could be determined accurately using this method.

Objective:To analyze the effect of nucleos(t)ide analog (NAs) antiviral treatment on the clinical features and prognosis of patients with hepatitis B virus-related hepatocellular carcinoma (HBV-HCC).Methods:A retrospective analysis was performed on the data of 450 HBV-HCC patients first diagnosed and treated in the Third Hospital of Hebei Medical University from January 2015 to January 2021, including 193 patients in the continuous NAs treatment group and 257 patients in the NAs treatment after hepatocellular carcinoma (HCC) group. The baseline data of the two groups were balanced by propensity score matching. The relapse-free survival rate of HCC was estimated by Kaplan-Meier method, and the risk factors for HCC recurrence were analyzed by Cox proportional risk models. Spearman correlation analysis was used to explore the association between clinical features of HCC and hepatitis B virus (HBV) DNA load in patients receiving continuous NAs treatment.Results:Before matching, the proportions of liver cirrhosis, body mass index≥25.0 kg/m 2, single tumor, maximum tumor diameter ≤5 cm, Child-Pugh grade A, China liver cancer staging Ⅰ in the continuous NAs treatment group were 93.8%(181/193), 45.1%(87/193), 70.5%(136/193), 82.4%(159/193), 74.6%(144/193) and 74.6%(144/193), respectively. All of them were higher than those in the NAs treatment after HCC group (87.5%(225/257), 44.0%(113/257), 61.1%(157/257), 55.3%(142/257), 63.8%(164/257) and 56.0%(144/257), respectively). The proportions of drinking history and portal vein tumor thrombi in the continuous NAs treatment group were 12.4%(24/193) and 3.1%(6/193), respectively, which were lower than 33.9%(87/257) and 10.5%(27/257) in the NAs treatment after HCC group.The differences were all statistically significant ( χ2=4.86, 7.58, 4.27, 36.63, 8.15, 21.05, 27.21 and 8.88, respectively, all P<0.05). After matching, the median relapse-free survival time of the patients in the continuous NAs treatment group and the NAs treatment after HCC group were 388 days and 277 days, respectively. The five-year cumulative relapse-free survival rates were 50.0% and 37.5%, respectively, with statistically significant difference ( χ2=5.30, P=0.021). Multivariate analysis showed that no antiviral therapy before diagnosis of HCC, multiple tumors, maximum tumor diameter ≥5 cm and palliative treatment were independent risk factors for HBV-HCC recurrence (hazard ratio ( HR)=1.509, 1.491, 0.446 and 1.472, respectively, all P<0.05). After matching, the maximum tumor diameter ( r=0.175, P=0.042), incidence of portal vein tumor thrombi ( r=0.210, P=0.014) and recurrence of HBV-HCC ( r=0.178, P=0.038) in the continuous NAs treatment group were positively correlated with HBV DNA load. Conclusions:Early initiation of NAs antiviral treatment can improve the tumor characteristics when the disease progresses to HBV-HCC, and improve the relapse-free survival rate of HBV-HCC patients. No antiviral therapy before diagnosis of HCC, multiple tumors, maximum tumor diameter ≥5 cm and palliative treatment are independent risk factors for HBV-HCC recurrence.

OBJECTIVE: To establish a method for detecting triphenyl phosphate( TPP) in the workplace air by gas chromatography. METHODS: TPP in the air of workplace was collected with glass fiber filter paper,desorbed with ether,separated by HP-5 gas chromatographic column,and detected by flame photometric detector. RESULTS: This method has good linear range of 12. 50-800. 00 mg/L,with the correlation coefficient of 0. 999 9. The detection limit was 0. 78 mg/L,and the minimum detectable concentration was 0. 09 mg/m3(sample volume was 45 L). Desorption efficiency was 97. 2%-99. 4%; standard recovery rate was 99. 5%-100. 3%. The within-run relative standard deviation( RSD) was 2. 7%-3. 4%and the between-run RSD was 1. 4%-3. 2%. The sampling efficiency was 99. 6%-100. 0%. The samples could be stored at room temperature for at least 14 days. CONCLUSION: The method is simple,accurate and highly sensitive for detecting TPP in workplace air.

Objective:To evaluate the efficacy and safety of oral anisodine hydrobromide tablets in the treatment of nonarteritic anterior ischemic optic neuropathy (NAION).Methods:A multicenter nonrandomized controlled trial was conducted.A total of 282 acute NAION patients (282 eyes) were recruited from 16 hospitals in China from July 2020 to May 2021.Patients were divided into two groups according to treatment methods, which were control group (124 cases, 124 eyes) receiving regular treatment including citicoline sodium plus Ginkgo biloba leaf liquid extract or Ginkgo biloba leaf extract tablets plus mecobalamin, and experimental group (158 cases, 158 eyes) receiving treatment in control group plus oral anisodine hydrobromide tablets 1 mg, twice daily for 2 to 3 months.Best corrected visual acuity (BCVA), visual field index (VFI), peripapillary retinal nerve fiber layer (pRNFL) and radial peripapillary capillary vessel density (RPC) were assessed at 1, 2, 3, and 6 months after enrollment using the standard decimal visual acuity chart, 750i Humphery visual field analyzer, Cirrus HD-OCT 4000/Cirrus HD-OCT 5000, RTVue-XR optical coherence tomography respectively.The primary outcomes were BCVA and VFI, and the secondary outcomes were pRNFL, RPC, and the side effects during the follow-up.The study adhered to the Declaration of Helsinki.All patients were fully informed about the treatment and purpose of this study and voluntarily signed the informed consent form.The study protocol was approved by Chinese PLA General Hospital (No.S2020-021-01). Results:In all, 242 patients (242 eyes) completed the follow-up of BCVA, and 98 patients (98 eyes) completed the VFI follow-up.In terms of visual function, BCVA and VFI improved significantly over time in the two groups, and BCVA and VFI were better in experimental group than in control group at various follow-up time points (all at P<0.05). In terms of structure, pRNFL gradually decreased in both groups with the extension of treatment, and pRNFL was significanthy thinner in experimental group than in control group at various follow-up time points (all at P<0.05). There was no significant difference in RPC between the two groups at the last follow-up ( P>0.05). There were two cases with side effects and one case was discontinued due to side effects 25 days after enrollment. Conclusions:Oral anisodine hydrobromide can improve visual acuity and visual field in NAION and accelerate the regression of optic disc edema, with good safety.

Objective: To establish a method for determination of methyl ethyl ketone in urine by headspace gas chromatography. Methods: In the urine sample(hereinafter referred to as urine sample), methyl ethyl ketone is pretreated by headspace technology, and a certain amount of head air is injected into the gas chromatograph, separated by capillary column, detected by hydrogen flame ionization detector, and the retention time is qualitative and the peak height is high. Peak area. Results: Good linearity was in the range of 0.01 to 6.0 μg/ml with a regression equation of y=13.316x+0.8497 and γ=0.9997.The minimum detectable concentration of methyl ethyl ketone was 0.01 μg/ml. The range intra-day RSD and inter-day RSD were 2.2%-5.5% and 2.5%-6.1% respectively. Urine samples can be stored for 20 days in the refrigerator at 4 ℃. Conclusion The method has a high advantage of sensitivity and accuracy, and also easy to operate. Therefore, it is suitable for the determination of methyl ethyl ketone in urine.

Accurate and efficient methods for identifying and tracking each animal in a group are needed to study complex behaviors and social interactions. Traditional tracking methods (e.g., marking each animal with dye or surgically implanting microchips) can be invasive and may have an impact on the social behavior being measured. To overcome these shortcomings, video-based methods for tracking unmarked animals, such as fruit flies and zebrafish, have been developed. However, tracking individual mice in a group remains a challenging problem because of their flexible body and complicated interaction patterns. In this study, we report the development of a multi-object tracker for mice that uses the Faster region-based convolutional neural network (R-CNN) deep learning algorithm with geometric transformations in combination with multi-camera/multi-image fusion technology. The system successfully tracked every individual in groups of unmarked mice and was applied to investigate chasing behavior. The proposed system constitutes a step forward in the noninvasive tracking of individual mice engaged in social behavior.
Animals ; Mice ; Deep Learning ; Zebrafish ; Algorithms ; Neural Networks, Computer ; Social Behavior