Objective To establish a rapid screening method for 34 emerging contaminants in surface water by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry(UHPLC-Q-TOF-MS).Methods The pretreatment conditions of solid phase extraction(SPE)were op-timized by orthogonal experimental design and the surface water samples were concentrated and ex-tracted by Oasis? HLB and Oasis? MCX SPE columns in series.The extracts were separated by Kine-tex? EVO C18 column,with gradient elution of 0.1%formic acid aqueous solution and 0.1%formic acid methanol solution.Q-TOF-MS'fullscan'and'targeted MS/MS'modes were used to detect 34 emerging contaminants and to establish a database with 34 emerging contaminants precursor ion,prod-uct ion and retention times.Results The 34 emerging contaminants exhibited good linearity in the con-centration range respectively and the correlation coefficients(r)were higher than 0.97.The limit of de-tection was 0.2-10 ng/L and the recoveries were 81.2%-119.2%.The intra-day precision was 0.78%-18.70%.The method was applied to analyze multiple surface water samples and 6 emerging contaminants were detected,with a concentration range of 1.93-157.71 ng/L.Conclusion The method is simple and rapid for screening various emerging contaminants at the trace level in surface water.

Objective To explore the efficacy of Krackow locking loop technique combined with the modified Kessler suture technique in the treatment of acute closed Achilles tendon rupture.Methods From January 2020 to January 2022,162 cases of acute closed Achilles tendon rupture were treated with Krackow locking loop technique combined with the modified Kessler suture technique.The patients were treated with the same postoperative rehabilitation plans.The American Orthopaedic Foot and Ankle Society(AOFAS)hindfoot score and Achilles Tendon Total Rupture Score(ATRS)were collected to evaluate the functions.Results The operation time was 24-40 min(mean,31.9±4.6 min).All incisions healed in one stage without infection or sural nerve injury.Complications occurred in 2 patients,including 1 case of deep venous thrombosis and 1 case of trauma-related re-rupture.The recovery time of ankle flexion and extension motion was4-12 weeks(mean,7.6±1.9 weeks),the recovery time of single-legged heel rise height on the affected side was 10-18 weeks(mean,13.3±1.8 weeks),and the recovery time of fast walking or jogging was 14-26 weeks(mean,19.1±1.8 weeks).The 162 patients was followed up for 14-25 months(mean,19.0 months).The AOFAS hindfoot score increased from(54.4±4.4)points preoperatively to(98.0±4.0)points at the last follow-up(t =-104.402,P =0.000).The ATRS score increased from(52.0±8.3)points preoperatively to(91.2±2.4)points at the last follow-up(t =-62.823,P = 0.000).Conclusions For young and middle-aged patients with acute closed Achilles tendon rupture,Krackow locking loop technique combined with the modified Kessler suture technique can achieve good clinical outcomes.Early functional exercise is required to return to work and life.

Objective To investigate the effects of an adeno-associated virus(AAV2)vector expressing secretory transforming growth factor-β(TGF-β)type Ⅱ receptor(sTβRⅡ)extracellular domain-IgG2a Fc fusion protein(sTβRⅡ-Fc)on proliferation and migration of triple-negative murine breast cancer 4T1 cells in mice.Methods The pAAV-sTβRⅡ-Fc vector expressing sTβRⅡ-Fc fusion protein constructed by molecular cloning,the capsid protein-expressing vector pAAV2 and the helper vector were co-transfected into HEK 293T cells to prepare the recombinant AAV2-sTβRⅡ virus,which was purified by density gradient centrifugation with iodixanol.Western blotting was used to examine the effects of AAV-sTβRⅡ virus on Smad2/3 phosphorylation in 4T1 cells and on expression levels of E-cadherin,vimentin and p-Smad2/3 in 4T1 cell xenografts in mice.BALB/c mice bearing subcutaneous xenografts of luciferase-expressing 4T1 cells received intravenous injections of AAV-sTβRⅡ virus,AAV-GFP virus or PBS(n=6)through the tail vein,and the proliferation and migration of 4T1 cells were analyzed with in vivo imaging.Ki67 expression in the tumor tissues and sTβRⅡ protein expressions in mouse livers were detected with immunohistochemistry and immunofluorescence staining,and tumor metastases in the vital organs were examined with HE staining.Results The recombinant pAAV-sTβRⅡ-Fc vector successfully expressed sTβRⅡ in HEK 293T cells.Infection with AAV2-sTβRⅡ virus significantly reduced TGF-β1-induced Smad2/3 phosphorylation in 4T1 cells and effectively inhibited proliferation and lung metastasis of 4T1 xenografts in mice(P<0.05).In the tumor-bearing mice,intravenous injection of AAV-sTβRⅡ virus significantly increased E-cadherin expression,reduced vimentin and Ki67 protein expressions and Smad2/3 phosphorylation level in the tumor tissues(P<0.05 or 0.01),and induced liver-specific sTβRⅡ expression without causing body weight loss or heart,liver,spleen or kidney pathologies.Conclusion The recombinant AVV2 vector encoding sTβRⅡ extracellular domain is capable of blocking the TGF-β signaling pathway to inhibit the proliferation and lung metastasis of 4T1 cells in mice.

Objective To investigate the effects of an adeno-associated virus(AAV2)vector expressing secretory transforming growth factor-β(TGF-β)type Ⅱ receptor(sTβRⅡ)extracellular domain-IgG2a Fc fusion protein(sTβRⅡ-Fc)on proliferation and migration of triple-negative murine breast cancer 4T1 cells in mice.Methods The pAAV-sTβRⅡ-Fc vector expressing sTβRⅡ-Fc fusion protein constructed by molecular cloning,the capsid protein-expressing vector pAAV2 and the helper vector were co-transfected into HEK 293T cells to prepare the recombinant AAV2-sTβRⅡ virus,which was purified by density gradient centrifugation with iodixanol.Western blotting was used to examine the effects of AAV-sTβRⅡ virus on Smad2/3 phosphorylation in 4T1 cells and on expression levels of E-cadherin,vimentin and p-Smad2/3 in 4T1 cell xenografts in mice.BALB/c mice bearing subcutaneous xenografts of luciferase-expressing 4T1 cells received intravenous injections of AAV-sTβRⅡ virus,AAV-GFP virus or PBS(n=6)through the tail vein,and the proliferation and migration of 4T1 cells were analyzed with in vivo imaging.Ki67 expression in the tumor tissues and sTβRⅡ protein expressions in mouse livers were detected with immunohistochemistry and immunofluorescence staining,and tumor metastases in the vital organs were examined with HE staining.Results The recombinant pAAV-sTβRⅡ-Fc vector successfully expressed sTβRⅡ in HEK 293T cells.Infection with AAV2-sTβRⅡ virus significantly reduced TGF-β1-induced Smad2/3 phosphorylation in 4T1 cells and effectively inhibited proliferation and lung metastasis of 4T1 xenografts in mice(P<0.05).In the tumor-bearing mice,intravenous injection of AAV-sTβRⅡ virus significantly increased E-cadherin expression,reduced vimentin and Ki67 protein expressions and Smad2/3 phosphorylation level in the tumor tissues(P<0.05 or 0.01),and induced liver-specific sTβRⅡ expression without causing body weight loss or heart,liver,spleen or kidney pathologies.Conclusion The recombinant AVV2 vector encoding sTβRⅡ extracellular domain is capable of blocking the TGF-β signaling pathway to inhibit the proliferation and lung metastasis of 4T1 cells in mice.

Objective To explore the automated identification and diameter measurement methods for inferior vena cava (IVC) based on clinical ultrasound images of IVC. Methods An automated identification and localization method based on topology and automatic tracking algorithm was proposed. Tracking algorithm was used for identifying and continuously locating to improve the efficiency and accuracy of measurement. Tests were conducted on 18 sets of ultrasound data collected from 18 patients in intensive care unit (ICU),with clinicians' measurements as the gold standard. Results The recognition accuracy of the automated method was 94.44％ (17/18),and the measurement error of IVC diameter was within the range of±1.96s (s was the standard deviation). The automated method could replace the manual method. Conclusion The proposed IVC automated identification and localization algorithm based on topology and automatic tracking algorithm has high recognition success rate and IVC diameter measurement accuracy. It can assist clinicians in identifying and locating IVC,so as to improve the accuracy of IVC measurement.

Purpose Focusing on the characteristics of for-malin fixed paraffin embedded(FFPE)samples,explored nano-magnetic bead nucleic acid extraction solutions with higher qual-ity/yield and continued to improve molecular pathology technolo-gy.Methods Alternative magnetic beads were synthesised in four major categories and 15 sub-categories and we screened to obtain high-quality/yield magnetic beads centred on FFPE samples.Simulated conventional tissues,simulated coarse needle punctures(liver),and simulated fiberoptic bronchoscopy sam-ples(lungs)were sectioned with the same number of serial slices in tubes.The nucleic acids of slices were extracted using the best magnetic beads screened in this study and common com-mercially available kits,and then perform comparison and purifi-cation quality parameters such as total amount and fragment size.The downstream applications of nucleic acids were validated by PCR and Sanger sequencing.Results Screening all homemade nanomagnetic beads centered on the DNA of FFPE samples,the total recoveries of the best performance nanomagnetic beads were obtained to be 58.5％±1.58％,and the total recoveries of five commercially available commercial magnetic beads and three do-mestic kit magnetic beads ranged from 18.68％to 40.71％.The total amount of DNA(ng)extracted from the same amount of tis-sue(serial slices),the nucleic acid yield of this study in simu-lated conventional tissues,simulated coarse needle punctures,and simulated fiberoptic bronchoscopy samples were increased by 39.49％-181.72％compared with those of the commercially a-vailable kits(P＜0.05).The total amount of extracted nucleic acid from simulated fiberoptic bronchoscopy tissue sections can be more than 100 ng for 1 slice(4 μm)and more than 400 ng for 5 slices.Conclusion The DNA purification nanomagnetic beads screened with DNA from FFPE samples have a significant enhancement comparing to the existing commercial bead proto-cols,and provide space for quality assurance,automated testing,and program expansion for clinical molecular pathology testing.

The study presents a method for the personalized biomechanical modeling of the human head and validates the generated model.Based on the TUST 50th percentile head biomechanical model,the method utilizes head CT data of the target model,and employs three-dimensional point cloud registration and free-form deformation techniques to rapidly develop a personalized head finite element model with detailed brain tissue structures.By reconstructing classic cadaver tests,it is found that the personalized head biomechanical model created by the proposed method shows a good consistency with the results of cadaver tests in kinematic and biomechanical responses.Furthermore,no significant differences are observed when compared with the head biomechanical model developed using reverse engineering method,thus verifying the effectiveness of the developed model.Consequently,the proposed method can be used to quickly construct personalized head biomechanical models with detailed anatomical structures,providing a fundamental computational analysis tool for researches in injury biomechanics,clinical medicine,and forensic identification.

Objective Meta modelling was employed to develop a risk prediction model for intradialytic hypotension(IDH)and validate the model.Methods Literature on risk factors for IDH published up to March 31,2023 was retrieved from 8 databases,including Cochrane Library,PubMed,Web of Science,EBSCO,Scopus,CINAHL,CNKI and Wanfang Database.Random effects model was used to combine ORs,and factors with P＜0.05 were selected to establish the model based on their regression coefficients.286 maintenance hemodialysis patients were selected as a validation cohort to evaluate the model's discrimination,calibration and clinical utility.Results 39 studies were included,involving 25 546 patients.14 factors were identified to establish the risk prediction model.The risk score for IDH occurrence was calculated as-0.301 × male+0.015 × age+0.004 × dialysis vintage+0.988 × diabetes+0.730 × cardiovascular disease-0.042 × predialysis systolic blood pressure+0.666 × dialysis mode of hemodialysis filter+0.076 × temperature+0.159 × ultrafiltration rate+0.476 × ultrafiltration volume+1.024 × weight gain between dialysis+0.053 × serum phosphorus+0.023 × blood urea nitrogen+0.040 ×β2-microglobulin.Definition in the Kidney Disease Outcomes Quality Initiative guideline,nadir intradialytic systolic blood pressure＜90 mmHg(1 mmHg=0.133 kPa),falling intradialytic systolic blood pressure ≥20 mmHg,and definition in the United Kingdom Kidney Association guideline were selected as 4 outcomes.The areas under the curve for the prediction model with respect to these 4 outcomes were 0.830,0.648,0.647,and 0.763,respectively.Calibration curves showed that the model predictive outcomes were consistent with actual outcomes for the first 2 outcomes(x2=14.824,P=0.064;x2=12.016,P=0.149).Decision curve analysis indicated that the model had better net benefit compared to either intervention/no intervention for all definitions.Conclusion The IDH risk prediction model developed by meta-modeling in this study has good predictive performance and certain application value.

Bacillus subtilis is recognized as a generally-regarded-as-safe strain, and has been widely used in the biosynthesis of high value-added products, including N-acetylneuraminic acid (NeuAc) which is widely used as a nutraceutical and a pharmaceutical intermediate. Biosensors responding to target products are widely used in dynamic regulation and high-throughput screening in metabolic engineering to improve the efficiency of biosynthesis. However, B. subtilis lacks biosensors that can efficiently respond to NeuAc. This study first tested and optimized the transport capacity of NeuAc transporters, and obtained a series of strains with different transport capacities for testing NeuAc-responsive biosensors. Subsequently, the binding site sequence of Bbr_NanR responding to NeuAc was inserted into different sites of the constitutive promoter of B. subtilis, and active hybrid promoters were obtained. Next, by introducing and optimizing the expression of Bbr_NanR in B. subtilis with NeuAc transport capacity, we obtained an NeuAc-responsive biosensor with wide dynamic range and higher activation fold. Among them, P535-N2 can sensitively respond to changes in intracellular NeuAc concentration, with the largest dynamic range (180-20 245) AU/OD. P566-N2 shows a 122-fold of activation, which is 2 times of the reported NeuAc-responsive biosensor in B. subtilis. The NeuAc-responsive biosensor developed in this study can be used to screen enzyme mutants and B. subtilis strains with high NeuAc production efficiency, providing an efficient and sensitive analysis and regulation tool for biosynthesis of NeuAc in B. subtilis.
N-Acetylneuraminic Acid/metabolism* ; Bacillus subtilis/metabolism* ; Promoter Regions, Genetic/genetics* ; Binding Sites ; Biosensing Techniques

To identify the active constituents in vitro and blood-absorbed ingredients in vivo from Yin Chen Hao decoction provides scientific evidence for probing its prevention and treatment mechanism on acute liver injury. An ultrahigh performance liquid chromatography quadrupole-time of flight-mass spectrometry (UPLC-QTOF/MS) method was applied for analysis of Yin Chen Hao decoction and the serum samples of mice with con-A induced acute liver injury after preventive oral administration for 14 days (the use of all laboratory animals in this study was approved by the Ethics Committee of the Naval Medical University, 19YF1459400). A total of 90 chemical constituents were identified from Yin Chen Hao decoction, mainly were flavonoids, terpenoids, tannins, quinones. 5 prototype compounds were identified in the serum, including chrysophanol, deoxyrhapontin-8-O-gallate, mussaenosidic acid, herniarin, emodin. The established UPLC-QTOF/MS method could efficiently and sensitively identify the constituents in vitro and blood-absorbed ingredients of Yin Chen Hao decoction, primarily clarify the material basis of its hepatoprotective effect, and provided a scientific basis for the quality marker selection and the pharmacodynamic material basis research on the decoction.