Digital polymerase chain reaction(dPCR)is a PCR technology that realizes accurate quantification of single-copy nucleic acid molecules by dividing the reaction system into tens of thousands of independent PCR reaction units for single-molecule-level amplification and integrating Poisson distribution.Due to its single-copy sensitivity and accurate quantification without the need of standard curves,dPCR has been widely used in disease diagnosis.By introducing technologies such as stepped emulsification and three-dimensional imaging,dPCR has been greatly improved in terms of accuracy,multiplexability and turnaround time,significantly enhancing its performance in clinical disease diagnosis.Based on this,this paper traced the technological development history of dPCR,gave an overview of its application in detection of tumors,infections and other diseases,and further discussed the challenges and opportunities of the development of dPCR,with the aim of providing a reference for the development and utilization of dPCR in the future,and promoting the high-quality development of molecular technology in clinical testing.

ObjectiveThe human angiotensin converting enzyme2 （hACE2） transgenic mouse model was used to clarify the antiviral efficacy of BD-77 against a novel coronavirus SARS-CoV-2 and explore the action mechanism of BD-77 against SARS-CoV-2. MethodSARS-CoV-2 Omicron and Delta variant strains-infected VeroE6 cell models were established and administered with BD-77 to observe the antiviral effect of BD-77 in vitro. A kit was used to detect the effect of BD-77 in vitro on the binding of spike S protein of SARS-CoV-2 virus （Delta/Omicron） to angiotensin converting enzyme2 （ACE2）. Chromatography was adopted to detect the binding of BD-77 to the S protein and N protein of the novel coronavirus. hACE2 transgenic C57BL/6 mice were divided into a blank control group， SARS-CoV-2 infection group， BD-77 administration groups of 37.5 mg·kg^-1 and 75 mg·kg^-1， with eight mice in each group. The pneumonia model of SARS-CoV-2-infected hACE2 transgenic mice was built to observe the survival of the mice， detect the virus titer of the lung tissue of the mice， and observe the lesions in the lung tissue. ResultBD-77 had a certain inhibitory effect on Omicron and Delta variant strains in vitro， with median inhibitory concentration （IC₅₀） of 526.3 mg·L^-1 and 653.0 mg·L^-1， respectively. BD-77 had no significant inhibitory effect on the binding of the S protein of WT， Omicron， and Delta variant strains of SARS-CoV-2 to ACE2 and had no binding effect with the S protein and N protein of the novel coronavirus. No mice in the blank group died， while the mortality rate of SARS-CoV-2-infected mice was 75%. There was a large amount of virus replication in the lung tissue of the mice and large areas of inflammatory infiltration in the lung tissue and interstitium. Compared with the model group， BD-77 administration groups of 37.5 mg·kg^-1 and 75 mg·kg^-1 could reduce the mortality of mice， significantly lower the virus titer in the lung tissue of mice （P<0.05）， and improve lung lesions. ConclusionBD-77 demonstrated significant inhibitory effects against SARS-CoV-2 virus in vitro and in vivo. However， its mechanism of action did not involve direct inhibition of the virus itself or intervention in the virus-host binding process. This finding suggests that the mechanism of action of BD-77 needs to be thoroughly investigated and elucidated by further experiments.

Tranexamic acid is widely used in joint orthopedic surgery.At the same time,it has high safety and few adverse drug reactions.It can effectively improve intraoperative bleeding and promote early functional recovery of patients.This article reviews the mode of administration,safe dose,administration time and adverse drug reactions of tranexamic acid in the perioperative period of joint replacement and arthroscopic surgery,in order to provide reference for the clinical application of tranexamic acid.

Objective To investigate the effects of total flavones from Oxytropis falcata Bunge on hepatic fibrosis(HF)induced by carbon tetrachloride and liver transforming growth factor(TGF-β)/Smad signaling pathway.Methods Forty-eight male rats were randomly divided into normal group(intraperitoneal injection of peanut oil,intragastric administration of 0.9％NaCl),model group(intraperitoneal injection of 40％CC14 peanut oil solution induced HF model,intragastric administration of 0.9％NaCl),positive control group(modeling,intragastric administration of 0.2 mg·kg-1 of colchicine),experimental-L,-M,-H groups(modeling,intragastric administration of 100,200 and 400 mg·kg-1 of total flavonoid extract of Oxytropis falcata Bunge),8 individuals in each group,for 4 consecutive weeks.The histopathological changes were observed by hematoxylin-eosin and Masson staining.Serum liver function and liver fibrosis were measured;erum inflammatory factors were detected;fluorescence quantitative polymerase chain reaction(RT-qPCR)was used to determine gene expression in liver.Results The pathological injury of liver tissue in the model group was serious,and a large number of inflammatory factors and collagen fibers were accumulated,while the rest of the treatment groups had different degrees of remission.In normal group,model group,positive control group,experimental-L,-M,-H groups,glutamic-pyruvic transaminase levels were(49.28±12.44),(5 885.42±948.37),(4 454.60±489.27),(4 650.47±843.53),(3 761.75±887.30)and(3 544.90±1 066.75)μg·L-1;glutamic-oxaloacetic transaminase levels were(186.90±46.89),(5 936.23±793.81),(3 971.37±780.28),(4 360.30±863.35),(3 943.10±439.47)and(3 971.38±631.08)μg·L-1;hyaluronic acid levels were(45.08±17.16),(104.32±36.06),(66.83±20.09),(70.30±21.07),(60.00±9.68)and(59.02±10.73)μg·L-1;laminin levels were(23.13±3.89),(60.85±13.66),(35.67±9.92),(39.98±9.39),(36.55±12.21)and(34.68±24.83)μg·L-1;type Ⅲ procollagen level were(24.98±5.34),(82.58±30.14),(40.70±16.14),(51.08±23.21),(43.60±12.48)and(44.20±11.66)p±g·L-1;interleukin(IL)-1β levels were(37.63±1.24),(46.10±3.23),(39.22±2.36),(41.33±0.93),(40.25±2.04)and(39.18±2.23)pg·mL-1;tumor necrosis factor-α levels were(314.58±20.56),(383.71±16.97),(349.00±7.93),(348.88±25.11),(325.75±27.84)and(335.07±21.33)pg·mL-1;TGF-β1 mRNA expression of relative quantity respectively were 1.00±0.00,60.99±15.70,9.61±1.59,7.37±1.09,6.41±0.64,6.87±1.09;Smad7 mRNA relative expression were 1.00±0.00,0.34±0.05,0.21±0.03,0.35±0.02,0.38±0.02,0.42±0.03.The above indexes in the model group were compared with the normal group,and the above indexes in the experimental-M,-H groups were compared with the model group,and the differences were statistically significant(P＜0.05,P＜0.01,P＜0.001).Conclusion Total flavonoids of Oxytropis falcata Bunge have protective effects on CC14-induced liver fibrosis in rats,and the mechanism may be related to the regulation of TGF-β/Smad pathway.

Objective To observe the intervention effect of hypericin(HYP)on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced Parkinson's disease(PD)mice model and its mechanism.Methods Thirty C57BL/6 mice were randomly divided into normal,model and experimental groups with 10 mice per group.PD mouse model was established after 7 days of intraperitoneal injection of MPTP,and drug intervention was carried out from the first day of modeling.Normal group and model group were intraperitoneally injected with 500 μL·kg·d-1 0.9％NaCl.The experimental group was intraperitoneally injected with 25 mg·kg·d-1 HYP.The three groups of rats were given the drug once each time for 14 days.The expression levels of tyrosine hydroxylase(TH),Nod-like receptor thermal protein domain protein 3(NLRP3)and ionized calcium binding adapter molecule 1(Iba1)in the striatum of nigra were detected by Western blot.Results The climbing time of normal,model and experimental groups was(5.35±0.43),(9.71±1.19)and(8.07±0.34)s;suspension scores were(2.92±0.15),(1.38±0.28)and(1.96±0.28)points;the relative expression levels of TH protein were 1.04±0.06,0.51±0.09 and 0.75±0.07;the relative expression levels of NLRP3 protein were 0.51±0.03,1.00±0.04 and 0.77±0.06;the relative expression levels of Iba1 protein were 0.68±0.10,1.30±0.28 and 0.89±0.05,respectively.The above indexes in the model group were statistically significant compared with the experimental group and the normal group(all P＜0.01).Conclusion HYP plays a therapeutic role in PD by inhibiting the expression of NLRP3 inflammasome in PD mice.

Objective:To understand the whole genome and genetic evolution characteristics of the first epidemic influenza A (H3N2) viruses in Wuxi from 2022-2023.Methods:Real time fluorescence quantitative RT-PCR method was used to perform typing on respiratory samples of influenza cases. Virus isolation was performed on samples with positive nucleic acid of subtype A H3N2 influenza virus detected. After cell culture, nucleic acid was extracted from strains with red blood cell agglutination test (HA) ≥ 1∶8, whole genome sequence was amplified, library was constructed, and computer sequencing was performed using MiSeq sequencer. Using NC_007366.1 as reference strain, the data were analyzed using CLC Genomics Workbench (Version 23) software. The phylogenetic tree was constructed using MEGA 7.0 software, and the N-glycosylation sites were predicted by NetNGlyc 1.0 Server software.Results:The nucleotide homology and amino acid homology among 35 strains of influenza A H3N2 virus from 2022 to 2023 were 96.4%-100% and 95.2%-100%, respectively. The 16 epidemic strains in 2022 belong to the 3C.2a1b.2a.1a evolutionary branch, while the 19 epidemic strains in 2023 belong to the 3C.2a1b.2a.2a.3a.1 evolutionary branch. There are 7 differences in the nucleotide sequence of the HA gene between the 2022 epidemic strain and the corresponding vaccine strain, sharing 15 mutation sites; There are 28 differences in the nucleotide sequence of the HA gene between the 2023 epidemic strain and the corresponding vaccine strain, sharing 17 mutation sites. The HA genes of 35 epidemic strains all lack N-glycosylation site 61: NSS, while in 2023, the HA genes of 19 epidemic strains added N-glycosylation site 110: NSS.Conclusions:The HA and NA genes of influenza A H3N2 virus in 2022 and 2023 belong to two evolutionary branches, respectively, and both show specific amino acid site changes compared to the corresponding vaccine strains. The antigen matching between the 2022 epidemic strain and the vaccine strain is relatively good, while there is a risk of low antigen matching between the 2023 epidemic strain and the vaccine strain.

Objective To investigate the independent risk factors of comprehensive complication index(CCI)≥26.2 after radical resection of colon cancer,and use these factors to establish and verify a dynamic web-based nomogram model.Methods The clinical data of colon cancer patients who underwent radical resection in the Affiliated Hospital of Jiangnan University from November 2020 to April 2022 were retrospectively collected,and divided into main cohort(November 2020 to October 2021,n=438)and validation cohort(November 2021 to April 2022,n=196).CCI scores of all patients were obtained based on CCI calculator(http://www.assessurgery.com).Univariate and multivariate logistic regression analysis were performed to identify the risk factors for CCI≥26.2,and a nomogram model was constructed.Receiver operator characteristic curve(ROC),C index and calibration curve were used to evaluate the differentiation and consistency of predictive nomogram model,and the decision curve analysis was conducted to assess the clinical benefits of the model.Internal validation of the model is performed in the validation cohort.Results A total of 438 patients were identified in present study,of which 63 cases(14.4%)had CCI≥26.2.Multivariate logistic regression analysis revealed that age≥60 years(OR=2.662,95%CI 1.341-5.285,P=0.005),low third lumbar spine skeletal muscle mass index(L3MI;OR=4.572,95%CI 2.435-8.583,P<0.001),NRS2002≥3(OR=4.281,95%CI 2.304-7.952,P<0.001),and preoperative bowel obstruction(OR=3.785,95%CI 1.971-7.268,P<0.001)were significant independent risk factors for postoperative CCI≥26.2.Based on these results,a static and web-based dynamic nomogram was established(https://jndxfsyywcwksyf.shinyapps.io/DynNomCCI/).The C-index and area under the curve(AUC)of the nomogram were 0.742 and 0.787,respectively.The calibration curve indicated a good consistency between the predicted probability and the actual probability.In the validation cohort,the nomogram also presented good discrimination(C-index=0.722,AUC=0.795)and predictive consistency.The decision curve analysis indicated the clinical benefit and application value of the nomogram prediction model.Conclusion This easy-to-use dynamic nomogram based on 4 independent risk factors can conveniently and reliably predict the probability of CCI≥26.2 after radical resection of colon cancer,which helps optimize the preoperative evaluation system,formulate precise individualized treatment strategies,and enhance recovery after surgery.

Objective To explore the modal testing method for the three-axis manned centrifuge under elastic boundary conditions with considerations on its complicated structure and high rotational inertia.Methods Modal testing was carried out with a three-axis manned centrifuge under elastic boundary conditions as the subject and a force hammer as the excitation source according to GJB 2706A-2008 Modal tests method for spacecraft and GB/T 11349.3-1992 Experimental determination of mechnical mobility measurements using impact excitation.Four times of hammering were carried out at each excitation position,and the data of the four times of hammering underwent linear average computation.Data acquisition was implemented with a three-axis accelerometer and a 64-channel data collector,and the modal data were analyzed using a frequency response function based on the Test.Lab modal test and analysis software.Results The coherence coefficient of the excitation signal was not lower than 0.8 in the 30 Hz band;the first three orders of the system's intrinsic vibrations were all torsional vibrations,with the frequencies of 9.15,15.66 and 19.22 Hz,respectively;the first order frequency of the system was about 9.15 Hz for both Z18 and Z21 excitation positions,and each of the second and third order frequencies similar situations were observed for also had a roughly equal value for the two excitation positions.Conclusion The force hammer testing method is applicable for the modal testing of the three-axis manned centrifuge,ensuring equipment safety and subject comfort.Referen-ces are provided for the following structural optimization design.[Chinese Medical Equipment Journal,2024,45(8):38-43]

Objective:To analyze the influence of digital skills mastery on life satisfaction among middle-aged and elderly adults and explore the underlying mechanism.Methods:Using the latest empirical data,this study employs latent category analysis,ordered logistic regression,generalized propensity score matching,generalized structural equation model,and KHB decomposition.Results:Internet users are classified into basic survival,practical life,and advanced mastery types based on their digital skills;Higherlevels of digital skills mastery significantly improve life satisfaction,though the effect plateaus after initial gains;social connection effect and health information effect positively,while negative experience effect negatively,mediate this relationship,with health information effect contributing the most to the mediating effect.Conclusions:Higher levels of digital skills mastery can improve life satisfaction among middle-aged and elderly adults,but it presents a'double-edged sword'effect.Expanding network coverage,enhancing digital skills,and improving the digital environment are essential to better integrate middle-aged and elderly adults into the digital society and mitigate negative impacts.

Traumatic supraorbital fissure syndrome (TSOFS) is a symptom complex caused by nerve entrapment in the supraorbital fissure after skull base trauma. If the compressed cranial nerve in the supraorbital fissure is not decompressed surgically, ptosis, diplopia and eye movement disorder may exist for a long time and seriously affect the patients′ quality of life. Since its overall incidence is not high, it is not familiarized with the majority of neurosurgeons and some TSOFS may be complicated with skull base vascular injury. If the supraorbital fissure surgery is performed without treatment of vascular injury, it may cause massive hemorrhage, and disability and even life-threatening in severe cases. At present, there is no consensus or guideline on the diagnosis and treatment of TSOFS that can be referred to both domestically and internationally. To improve the understanding of TSOFS among clinical physicians and establish standardized diagnosis and treatment plans, the Skull Base Trauma Group of the Neurorepair Professional Committee of the Chinese Medical Doctor Association, Neurotrauma Group of the Neurosurgery Branch of the Chinese Medical Association, Neurotrauma Group of the Traumatology Branch of the Chinese Medical Association, and Editorial Committee of Chinese Journal of Trauma organized relevant experts to formulate Chinese expert consensus on the diagnosis and treatment of traumatic supraorbital fissure syndrome ( version 2024) based on evidence of evidence-based medicine and clinical experience of diagnosis and treatment. This consensus puts forward 12 recommendations on the diagnosis, classification, treatment, efficacy evaluation and follow-up of TSOFS, aiming to provide references for neurosurgeons from hospitals of all levels to standardize the diagnosis and treatment of TSOFS.