In recent years, the bacteriophage Φ29 (Phi29) DNA polymerase has garnered increasing attention due to its high-fidelity amplification capacity at constant temperatures. To advance the industrial application of this type of isothermal polymerases, this study mined and characterized new enzymes from the microbial metagenome based on the known Phi29 DNA polymerase sequence. The results revealed that a new enzyme, Php29 DNA polymerase, was identified in the microbial metagenome with plants as the hosts. This enzyme exhibited higher strand displacement activity, with a 59.5% similarity to bacteriophage Φ29. Experimental validation demonstrated that the enzyme had 3'→5' exonuclease activity, and its amplification products can serve as substrates for further catalytic reactions. The discovery and validation of Php29 DNA polymerase gives insights into the future industrial application of isothermal polymerases.
DNA-Directed DNA Polymerase/metabolism* ; Bacillus Phages/genetics* ; Metagenome

This study was aimed at investigating the prevalence of Dabie bandavirus(DBV)infection in suspected cases of se-vere fever with thrombocytopenia syndrome(SFTS)and tick specimens in Cangzhou City from 2023 to 2024,and providing scientific basis for the prevention,control and pathogen surveillance of SFTS in this area.Pathogen detection and virus isolation were performed on suspected SFTS cases and tick specimens collected in Cangzhou City from 2023 to 2024.The next-generation sequencing technol-ogy was used to conduct whole-genome sequencing of DBV.A phylogenetic tree was constructed using software such as MEGA,DNA Star,and homology comparison and amino acid variation site analysis were carried out.Among the 70 suspected SFTS cases,the DBV positive detection rate was 60%(42/70).The positive cases were mainly farmers aged 50-79,concentrated in Yanshan County and Haixing County.402 ticks were pooled into 31 sample tubes,among which 2 tubes tested positive for DBV nucleic acid,with a mini-mum infection rate of 0.50%.A total of 9 human-derived and 2 tick-derived DBV strains were isolated.The whole-genome sequencing results showed that all strains clustered within the F branch,with sequences homology exceeding 99%.There were a total of 10 amino acid variation sites in the RdRP,GP and NSs sequences.Therefore,the distribution of SFTS cases in Cangzhou City exhibited regional clustering.The overall level of DBV infection in ticks in this region was relatively low.It is recommended to further improve the disease early warning mechanism and continue to conduct pathogen surveillance.

To tackle the challenges posed by low resolution,weak contrast,and positional variations in liver tumor ultrasound images,which affects the diagnostic efficiency and accuracy,a novel method based on prototype generation and contrastive learning is proposed for liver tumor segmentation in ultrasound images.The core of this method is a weighted mask attention Transformer structure which utilizes the probabilities of real categories in the predicted probability distribution to weight image feature vectors,generates class prototypes with category discrimination,and thereby effectively captures key features while enhancing spatial information representation.By combining contrastive loss with Dice cross-entropy loss,the model achieves significant improvements in both category discrimination capability and segmentation accuracy,and overcomes the limitations of traditional models related to insufficient spatial information and intra-class pixel distribution imbalance.Comprehensive evaluations of the proposed method are conducted on a collected dataset of 253 ultrasound images,and the experimental results reveal that the proposed method attains a mean intersection-over-union of 78.44%and a Dice similarity coefficient of 87.41%,validating its superiority in liver tumor segmentation from ultrasound image.

This study was aimed at investigating the prevalence of Dabie bandavirus(DBV)infection in suspected cases of se-vere fever with thrombocytopenia syndrome(SFTS)and tick specimens in Cangzhou City from 2023 to 2024,and providing scientific basis for the prevention,control and pathogen surveillance of SFTS in this area.Pathogen detection and virus isolation were performed on suspected SFTS cases and tick specimens collected in Cangzhou City from 2023 to 2024.The next-generation sequencing technol-ogy was used to conduct whole-genome sequencing of DBV.A phylogenetic tree was constructed using software such as MEGA,DNA Star,and homology comparison and amino acid variation site analysis were carried out.Among the 70 suspected SFTS cases,the DBV positive detection rate was 60%(42/70).The positive cases were mainly farmers aged 50-79,concentrated in Yanshan County and Haixing County.402 ticks were pooled into 31 sample tubes,among which 2 tubes tested positive for DBV nucleic acid,with a mini-mum infection rate of 0.50%.A total of 9 human-derived and 2 tick-derived DBV strains were isolated.The whole-genome sequencing results showed that all strains clustered within the F branch,with sequences homology exceeding 99%.There were a total of 10 amino acid variation sites in the RdRP,GP and NSs sequences.Therefore,the distribution of SFTS cases in Cangzhou City exhibited regional clustering.The overall level of DBV infection in ticks in this region was relatively low.It is recommended to further improve the disease early warning mechanism and continue to conduct pathogen surveillance.

To tackle the challenges posed by low resolution,weak contrast,and positional variations in liver tumor ultrasound images,which affects the diagnostic efficiency and accuracy,a novel method based on prototype generation and contrastive learning is proposed for liver tumor segmentation in ultrasound images.The core of this method is a weighted mask attention Transformer structure which utilizes the probabilities of real categories in the predicted probability distribution to weight image feature vectors,generates class prototypes with category discrimination,and thereby effectively captures key features while enhancing spatial information representation.By combining contrastive loss with Dice cross-entropy loss,the model achieves significant improvements in both category discrimination capability and segmentation accuracy,and overcomes the limitations of traditional models related to insufficient spatial information and intra-class pixel distribution imbalance.Comprehensive evaluations of the proposed method are conducted on a collected dataset of 253 ultrasound images,and the experimental results reveal that the proposed method attains a mean intersection-over-union of 78.44%and a Dice similarity coefficient of 87.41%,validating its superiority in liver tumor segmentation from ultrasound image.

OBJECTIVE To investigate the intervention effect and potential mechanism of breviscapine on hepatic fibrosis （HF） in rats based on the transforming growth factor-β（1 TGF-β1）/Smad2/extracellular signal-regulated protein kinase 1（ERK1） and Kelch-like epichlorohydrin-associated protein 1（Keap1）/nuclear factor-erythroid 2-related factor 2（Nrf2）/heme oxygenase-1（HO-1） pathways. METHODS Totally 60 rats were randomly divided into normal control group， model group， breviscapine low-dose， medium-dose and high-dose groups （5.4， 10.8， 21.6 mg/kg）， and colchicine group （positive control， 0.45 mg/kg）， with 10 rats in each group， half male and half female. Except for the normal control group， HF model of the other groups was induced by carbon tetrachloride. Subsequently， each drug group was given corresponding medicine by gavage once a day for 28 days. The liver appearance of rats in each group was observed and their liver coefficients were calculated. The levels of alanineaminotransferase （ALT） and aspartate aminotransferase （AST）in serum， those of ALT， AST， superoxide dismutase （SOD），malondialdehyde （MDA） and glutathione peroxidase （GSH- Px） in liver tissue were detected. The liver tissue inflammatory and fibrotic changes were observed. The protein and mRNA expressions of TGF-β1， Smad2， ERK1， Nrf2， Keap1 and HO-in liver tissue were detected. RESULTS Compared with the normal control group， the model group showed large areas of white nodular lesions in the liver， obvious inflammatory cell infiltration and collagen fiber deposition. The body weight， the levels of SOD and GSH-Px in liver tissue， the protein and mRNA expressions of Nrf2 and HO-1 were significantly lowered in the model group （P＜0.05）； the liver coefficient， the percentage of Masson staining positive area， ALT and AST levels of serum and liver tissue， MDA level of liver tissue， the protein and mRNA expressions of TGF-β1， Smad2， ERK1 and Keap1 were significantly increased （P＜0.05）. Compared with the model group， the liver lesions of rats in each drug group were improved， and the above quantitative indexes were generally reversed （P＜0.05）. CONCLUSIONS Breviscapine has a good intervention effect on HF rats， which may be related to inhibiting TGF-β1/Smad2/ERK1 pathway for anti-fibrosis and regulating Keap1/Nrf2/HO-1 pathway to inhibit oxidative stress.

Objective: To explore the real experience of functional exercise after PICC operation. Methods: Phenomenological methods were used to conduct semi-structured interviews with 15 patients who had different functional exercises after PICC. Colaizzi phenomenological analysis was used to analyze the data. Results: Through interviews, four themes were drawn: the exercise characteristics of different postoperative functional exercise, the benefits of postoperative functional exercise, the obstacles to postoperative functional exercise and the suggestions for education related to postoperative functional exercise. Conclusion The patients with PICC think that the postoperative functional exercise is safe and practical, but the recognition and compliance of the postoperative functional exercise are still limited. It is suggested that appropriate training should be carried out among medical staff, so as to rationally select the way of postoperative functional exercise, further promote the application of postoperative functional exercise, and improve the compliance and experience of patients.

Objective To explore the function and mechanism of estrogen receptor α (ERα) in bladder cancer cell proliferation and aggressivity.Methods The ERα expression bladder cancer cell line T24ERα model was established.The cell growth was detected by MTT assay,apoptosis by flow cytometry,cell invasion by matrigel transwell.Western blot was used to check signals by ERα regulation in bladder cancer cells related to the proliferation and metastatic ability.Results Compared to the control group,the cell inhibition rates of experimental group in 96 h and 144 h were 18.85％ and 37.21％,respectively.The difference was significant compared with the control group (P ＜ 0.05).The apoptosis rates of the experimental group and control group were (18.93 ±1.41)％ and (9.91 ±1.08)％ (P＜0.05).The experimental group through matrix adhesive cell proportion was (10.00 ± 2.00)％,significantly lower than that of the control group (26.00 ± 3.61) ％ (P ＜ 0.05).Western blot showed integrin-β1,p-FAK,p-Src and Scr expression were reduced compared to control group (P ＜ 0.05).Conclusion ERα could inhibit bladder cancer cell growth and metastasis through down-regulating integrin-β1-FAK/Src signal pathway,while promote the apoptosis of bladder cancer cells.

0.05). 100% occlusion was achieved in 18 patients with cerebral aneurysms by using embolization. Conclusion 3D DSA may improve the accuracy in diagnosing SAH and in showing clearly the stereo conformation of aneurysm and the relationship of sac and parent artery. It is helpful in the evaluation and guidance of embolization of cerebral aneurysms.