Objective To investigate the toxicokinetic differences of 3,4-methylenedioxy-N-methylamphetamine(MDMA)and its metabolite 4,5-methylene dioxy amphetamine(MDA)in rats af-ter single and continuous administration of MDMA,providing reference data for the forensic identifica-tion of MDMA.Methods A total of 24 rats in the single administration group were randomly divided into 5,10 and 20 mg/kg experimental groups and the control group,with 6 rats in each group.The ex-perimental group was given intraperitoneal injection of MDMA,and the control group was given intraperi-toneal injection of the same volume of normal saline as the experimental group.The amount of 0.5 mL blood was collected from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.In the continuous administration group,24 rats were randomly divided into the experi-mental group(18 rats)and the control group(6 rats).The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5,7,9,11,13,15,17 mg/kg per day,respectively,while the control group was given the same volume of normal saline as the experimental group by in-traperitoneal injection.On the eighth day,the experimental rats were randomly divided into 5,10 and 20 mg/kg dose groups,with 6 rats in each group.MDMA was injected intraperitoneally,and the con-trol group was injected intraperitoneally with the same volume of normal saline as the experimental group.On the eighth day,0.5 mL of blood was taken from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels,and statistical software was employed for data analysis.Results In the single-administration group,peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration,respectively,with the largest detection time limit of 12 h.In the continuous administration group,peak concentrations were reached at 30 min and 1.5 h af-ter administration,respectively,with the largest detection time limit of 10 h.Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows:T=10.362C-1.183,R2=0.974 6;T=7.397 3C-0.694,R2=0.961 5(T:injection time;C:concentration ratio of MDMA to MDA in plasma).Conclusions The toxicokinetic data of MDMA and its metabolite MDA in rats,obtained through single and continuous administration,including peak concentration,peak time,detection time limit,and the relationship between concentration ratio and administration time,provide a theoretical and data foundation for relevant forensic identification.

ObjectiveTo explore whether miR-375 regulates the malignant characteristics of osteosarcoma (OS) by influencing the expression of MMP13. MethodsPlasmid DNAs and miRNAs were transfected into OS cells and HEK293 cells using Lipofectamine 3000 reagent. Real-time quantitative polymerase chain reaction was performed to measure the expression of miR-375 and MMP13 in OS patients and OS cells. Western blot was performed to analyze the MMP13 protein in the patients with OS and OS cells. The targeting relationship between miR-375 and MMP13 was analyzed by luciferase assay. Migration and invasion were analysed by heal wound and transwell assays, respectively. ResultsmiR-375 expression in OS tissues was lower than that in normal tissues. The expression of MMP13 was upregulated in OS tissues. MMP13 expression was negatively correlated withmiR-375 expression in patients with OS. Migration and invasion were significantly inhibited in OS cells with the miR-375 mimic compared with OS cells with the miRNA control. MMP13 partially reversed the inhibition of migration and invasion induced by miR-375 in the OS cells. ConclusionmiR-375 attenuates migration and invasion by downregulating the expression of MMP13 in OS cells.

This study design of specific identification primers for the ITS2 sequence of F. ussuriensis. The reaction system and conditions were optimized, and PCR-nucleic acid test strips were constructed to realize the visual detection of F. ussuriensis Bark. Through molecular cloning and sequencing technology, we constructed a positive control for F. ussuriensis DNA and formulated quality standards. The established method was evaluated for sensitivity, specificity and reproducibility, and the authenticity of the commercially available samples was identified. Results demonstrated that based on the ITS2 sequences, F. ussuriensis and its mixed forgeries could be distinguished. The PCR products of the authentic F. ussuriensis on test strips showed two bands in the T and C lines, while the pseudo products and negative control showed only one band in the C line, which was consistent with the results of agarose gel electrophoresis. The specificity was 100%, and the sensitivity of the PCR-nucleic acid test strip was up to 0.1 ng·μL^-1, which was 10 times higher than that of the gel electrophoresis assay. 11 out of 16 commercially available samples of F. ussuriensis were qualified, and 5 were unqualified. Collectively, the PCR-nucleic acid test strip method established in this study is specific, rapid, accurate and visualized, which can provide a new technical idea for the detection of F. ussuriensis.

Objective:To study the current status of longitudinal extrauterine growth restriction (EUGR) in extremely preterm infants (EPIs) and to develop a prediction model based on clinical data from multiple NICUs.Methods:From January 2017 to December 2018, EPIs admitted to 32 NICUs in North China were retrospectively studied. Their general conditions, nutritional support, complications during hospitalization and weight changes were reviewed. Weight loss between birth and discharge > 1SD was defined as longitudinal EUGR. The EPIs were assigned into longitudinal EUGR group and non-EUGR group and their nutritional support and weight changes were compared. The EPIs were randomly assigned into the training dataset and the validation dataset with a ratio of 7∶3. Univariate Cox regression analysis and multiple regression analysis were used in the training dataset to select the independent predictive factors. The best-fitting Nomogram model predicting longitudinal EUGR was established based on Akaike Information Criterion. The model was evaluated for discrimination efficacy, calibration and clinical decision curve analysis.Results:A total of 436 EPIs were included in this study, with a mean gestational age of (26.9±0.9) weeks and a birth weight of (989±171) g. The incidence of longitudinal EUGR was 82.3%(359/436). Seven variables (birth weight Z-score, weight loss, weight growth velocity, the proportion of breast milk ≥75% within 3 d before discharge, invasive mechanical ventilation ≥7 d, maternal antenatal corticosteroids use and bronchopulmonary dysplasia) were selected to establish the prediction model. The area under the receiver operating characteristic curve of the training dataset and the validation dataset were 0.870 (95% CI 0.820-0.920) and 0.879 (95% CI 0.815-0.942), suggesting good discrimination efficacy. The calibration curve indicated a good fit of the model ( P>0.05). The decision curve analysis showed positive net benefits at all thresholds. Conclusions:Currently, EPIs have a high incidence of longitudinal EUGR. The prediction model is helpful for early identification and intervention for EPIs with higher risks of longitudinal EUGR. It is necessary to expand the sample size and conduct prospective studies to optimize and validate the prediction model in the future.

Objective To design a medical order pre-evaluation tool for perioperative prophylactic application of antibiotics,and to improve the efficiency of antibiotics management in hospitals during the perioperative period.Methods Using the open-source software R as the platform,a web application was built with tidy verse and shiny package based on related documents and guidelines.The discharge records of Affiliated Hospital of North Sichuan Medical College from April 1,2021,to December 31,2022,were retrospectively reviewed using the constructed pre-evaluation tool and compared with previous manual evaluation results using McNemar's Chi-squared test.Results This medical order pre-evaluation tool can quickly complete perioperative antibiotics order sampling,batch pre-evaluation,result statistics,visualization,and result output,and flexibly adjust the evaluation rules according to actual needs.The pre-evaluation tool is more efficient,with a review speed of 13.46 ms per medical record.Among the 2 642 discharge medical records of manual review,there was no significant difference between systematic pre-evaluation and manual evaluation results(ratio of prophylactic use:76.85%vs.78.21%)in terms of the type of use(preventive or curative)(P= 0.078).Among the 1 857 discharge records judged to be prophylactic for both manual and systematic reviews,the difference in unreasonable detection rate(39.90%vs.30.32%)was statistically significant(P＜0.001).Among the 63 typical ludicrous medical records confirmed by the review of clinical pharmacists with senior professional titles,60 were judged and limited by the pre-evaluation tool,and the detection rate of typical unreasonable was 95.24%.Conclusions The pre-evaluation tool based on R in this study can improve the efficiency of perioperative antibacterial drug evaluation.The evaluation conclusions and statistical results are reliable and are worthy of further development and application.

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

Eighteen compounds were isolated from the methanol extract of the fruits of Litsea cubeba by silica gel, ODS, Sephadex LH-20 column chromatography, semi-preparative RP-HPLC, chiral HPLC and recrystallization. Their structures were elucidated by spectroscopic analyses and by comparison with reported spectroscopic data and physicochemical properties, and the absolute configurations of the enantiomers were established by experimental and calculated electronic circular dichroism spectra. These compounds were identified as (+)-(R)-4-hydroxypiperitenone (1a), (-)-(S)-4-hydroxypiperitenone (1b), (3S,4S,6R)-3,6-dihydroxy-1-menthene (2), (4S,5R)-4-hydroxy-5-isopropyl-2-methylcyclohex-2-en-1-one (3), (R)-6-hydroxy-3-(2-hydroxypropan-2-yl)-6-methylcyclohex-2-enone (4), (4S,6R)-4-hydroxy-6-isopropyl-3-methylcyclohex-2-enone (5), (1R,3S,4R)-3-hydroxy isopulegol (6), subamone (7), (6S)-3,7-dimethyl-7-hydroxy-2(Z)-octen-6-olide (8), (6S)-6,7-dihydroxy-3,7-dimethyloct-2(Z)-enoate (9), holostylactone (10), sesamin (11), dimethylmatairesinol (12), p-hydroxybenzoylcarbinol (13), syringaldehyde (14), p-hydroxybenzaldehyde (15), 4-hydroxy-3-methoxybenzaldehyde (16), 5,4ʹ-dihydroxy-7-methoxyflavone (17). Among them, compounds 1a and 1b were a pair of new monoterpenoid enantiomers, 8 and 9 were new natural products, 2-7, 10, 11 and 17 were isolated from Litsea genus for the first time. The in vitro anti-inflammatory effects of compounds 1-17 were evaluated using lipopolysaccharide-stimulated RAW264.7 cells, the results showed that compound 14 exhibited significant anti-inflammatory activity with NO inhibitory rate of 66.27% at a concentration of 40 μmol·L^-1.

The abuse and irrational use of antibiotics in human veterinary medicine has seriously endangered the ecological environment and human health.In this study,a fully automatic solid-phase disk extraction-stable isotope dilution-ultra-high performance liquid chromatography-mass spectrometry method for determination of 17 kinds of sulfonamides antibiotics(SAs)in water was established,which was then applied to determination of SAs in real samples including tap water,river water and seawater,respectively.Meanwhile,the residual characteristics were discussed and the ecological risks were assessed.With this method,1.0 L water sample with 0.5 g/L Na2EDTA(pH=3)was extracted and enriched by 3M SDB-XC disk,and eluted by 10 mL of mixture of methanol and acetone(1:1,V/V),and the pretreatment time of the sample was about 60 min per six samples.Under the optimized conditions,the linearity of the method for detection of 17 kinds of SAs ranged from 0.05 to 100 μg/L,with correlation coefficients(R2)>0.999.In addition,the detection limits(S/N=3)were as low as 0.012-0.052 ng/L,and the recoveries were in the range of 76%-110%,with relative standard deviations of 0.5%-9.6%(n=5).The results showed that no SAs was detected in tap water,while 3 and 9 kinds of SAs were detected in river water of Zhoushan,and seawater of Wenzhou Sea area in Zhejiang province,respectively.The total concentrations of the detected SAs were 0.875-21.826 ng/L and 1.024-20.768 ng/L in river water and seawater,respectively,and among which,sulfamethoxazole(SMX)was the predominant compound in river water and seawater,accounting for 81%and 74%of the total SAs,respectively.The ecological risk assessment showed that the risk quotients of the detected SAs in the river water and seawater in the study area for the three kinds of trophic organisms(algae,Daphnia and fish)were far less than 0.01,meaning that the ecological risk was low.

Pediatric acute liver failure(PALF)is a rare and rapidly progressive clinical syndrome with a poor prognosis and significant mortality.The etiology of PALF is complex,and it presents with diverse and atypical clinical manifestations.Accurate diagnosis based on age-related factors,early recognition or prevention of hepatic encephalopathy,and precise supportive treatment targeting the underlying cause are crucial for improving outcomes and prognosis.This article provides a comprehensive review of recent research on the diagnosis and treatment of PALF,aiming to offer guidance for clinical practice.[Chinese Journal of Contemporary Pediatrics,2024,26(2):194-200]

Further evidence is needed to explore the impact of high-altitude environments on the neurologic function of neonates.Non-invasive techniques such as cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography can provide data on cerebral oxygenation and brain electrical activity.This study will conduct multiple cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography monitoring sessions at various time points within the first 3 days postpartum for healthy full-term neonates at different altitudes.The obtained data on cerebral oxygenation and brain electrical activity will be compared between different altitudes,and corresponding reference ranges will be established.The study involves 6 participating centers in the Chinese High Altitude Neonatal Medicine Alliance,with altitude gradients divided into 4 categories:800 m,1 900 m,2 400 m,and 3 500 m,with an anticipated sample size of 170 neonates per altitude gradient.This multicenter prospective cohort study aims to provide evidence supporting the impact of high-altitude environments on early brain function and metabolism in neonates.[Chinese Journal of Contemporary Pediatrics,2024,26(4):403-409]