Hepatitis B virus （HBV） exclusively infects liver parenchymal cells and forms covalently closed circular DNA （cccDNA） within their nuclei. HBV cccDNA serves as the essential template for viral gene transcription， the sole source of progeny virus production， and the key driver of viral antigen expression， and it is the molecular basis for the persistence of HBV infection. Therefore， elimination and/or functional silencing of cccDNA is the key to eradicate chronic HBV infection. This article discusses the critical scientific issues that need to be solved during elimination of the harm of HBV infection from the perspectives of the synthesis， transcription， and clearance of cccDNA， as well as the impact of nonparenchymal cells on cccDNA， in order to provide a reference for eradicating HBV infection in the future.

Objective To observe the effects of Bushen Huoxue Prescription on the pathway related to necroptosis of nucleus pulposus cells in a model rabbit of intervertebral disc degeneration;To explore its mechanisms in delaying intervertebral disc degeneration.Methods A intervertebral disc degeneration rabbit model was established using the spinal instability method.Totally 40 model rabbits were randomly divided into model group,ibuprofen group and Bushen Huoxue Prescription low-,medium-and high-dosage groups.Additionally,a normal control group and a sham-operation group were set up,with 8 rabbits in each group.Each treatment groups received the corresponding drugs via gavage for two consecutive weeks.HE staining was used to observe morphology of nucleus pulposus tissue,transmission electron microscopy was used to observe ultrastructure in nucleus pulposus cells,immunohistochemical staining was used to assess the expressions of Aggrecan and Collagen Ⅱ in nucleus pulposus tissue,Western blot was used to detect the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein in nucleus pulposus tissue.Results Compared with the sham-operation group,the model group showed a significant decrease in nucleus pulposus cells,disordered cell arrangement,reduced extracellular matrix,interrupted cell membrane continuity under transmission electron microscopy,organelle swelling,nuclear membrane disruption,partial chromatin loss,and positive expression of Aggrecan and Collagen Ⅱ in nucleus pulposus tissue decreased(P<0.01),while the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein significantly increased(P<0.01).Compared with the model group,the treatment groups showed an increased number of nucleus pulposus cells with orderly arrangement and more extracellular matrix,the ultrastructural damage of the cell membrane,organelle and nucleus in nucleus pulposus cells was partially restored under transmission electron microscopy,the positive expressions of Aggrecan and Collagen Ⅱ significantly increased in Bushen Huoxue Prescription medium-and high-dosage groups and the ibuprofen group(P<0.05,P<0.01),while the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein significantly decreased(P<0.05,P<0.01).Conclusion Bushen Huoxue Prescription may delay intervertebral disc degeneration of the model rabbit by inhibiting the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein in nucleus pulposus cells,and promoting the generation of extracellular matrix components Aggrecan and Collagen Ⅱ.

Objective To observe the effects of Bushen Huoxue Prescription on pressure-induced necroptosis in human nucleus pulposus cells and the expressions of RIPK1/RIPK3/MLKL pathway;To explore its potential mechanism in delaying intervertebral disc degeneration.Methods Human primary nucleus pulposus cells were cultured in vitro,and a model of nucleus pulposus cell degeneration was established using continuous load pressure method.After modeling,the nucleus pulposus cells were divided into model group,Bushen Huoxue Prescription group and inhibitor group,blank serum,Bushen Huoxue Prescription containing serum and necroptotic apoptosis inhibitor(Nec-1)intervention were administered,respectively.Normal group nucleus pulposus cells were cultured routinely.AO/EB fluorescence dual staining method was used for detecting cell apoptosis,flow cytometry was used to detect the necroptosis rate of nucleus pulposus cells,Western blot was used to detect the protein expressions of p-receptor interacting protein kinase(RIPK)1,p-RIPK3 and p-mixed lineage kinase domain like protein(MLKL),RT-qPCR was used to detect the mRNA expressions of RIPK1,RIPK3 and MLKL.Results Compared with the normal group,the model group showed more red fluorescence under AO/EB staining of nucleus pulposus cells,which were round and condensed,the necroptosis rate of nucleus pulposus cells increased(P<0.05),the protein expressions of p-RIPK1,p-RIPK3 and p-MLKL increased(P<0.05,P<0.01),while there was no significant difference in RIPK1 mRNA expression(P>0.05),and RIPK3 and MLKL mRNA expression increased(P<0.01).Compared with the model group,Bushen Huoxue Prescription group and the inhibitor group had less red condensed chromatin in the nucleus pulposus cells,Bushen Huoxue Prescription group had a lower rate of necroptosis(P<0.05),while the inhibitor group showed a decreasing trend in necroptosis rate(P>0.05),the protein expressions of p-RIPK1,p-RIPK3 and p-MLKL decreased in Bushen Huoxue Prescription group and the inhibitor group(P<0.05,P<0.01),while there was no significant difference in RIPK1 mRNA expression(P>0.05),and RIPK3 and MLKL mRNA expressions decreased(P<0.01).Conclusion Bushen Huoxue Prescription can alleviate pressure-induced damage to nucleus pulposus cells and inhibit necroptosis,thereby slowing the progression of intervertebral disc degeneration.Its mechanism may be related to the RIPK1/RIPK3/MLKL pathway mediated necroptosis.

Recently,diffusion models have emerged as a promising paradigm for molecular design and optimization.However,most diffusion-based molecular generative models focus on modeling 2D graphs or 3D geom-etries,with limited research on molecular sequence diffusion models.The International Union of Pure and Applied Chemistry(IUPAC)names are more akin to chemical natural language than the simplified molecular input line entry system(SMILES)for organic compounds.In this work,we apply an IUPAC-guided conditional diffusion model to facilitate molecular editing from chemical natural language to chemical language(SMILES)and explore whether the pre-trained generative performance of diffusion models can be transferred to chemical natural language.We propose DiffIUPAC,a controllable molecular editing diffusion model that converts IUPAC names to SMILES strings.Evaluation results demonstrate that our model out-performs existing methods and successfully captures the semantic rules of both chemical languages.Chemical space and scaffold analysis show that the model can generate similar compounds with diverse scaffolds within the specified constraints.Additionally,to illustrate the model's applicability in drug design,we conducted case studies in functional group editing,analogue design and linker design.

Objective To observe the effects of Bushen Huoxue Prescription on the pathway related to necroptosis of nucleus pulposus cells in a model rabbit of intervertebral disc degeneration;To explore its mechanisms in delaying intervertebral disc degeneration.Methods A intervertebral disc degeneration rabbit model was established using the spinal instability method.Totally 40 model rabbits were randomly divided into model group,ibuprofen group and Bushen Huoxue Prescription low-,medium-and high-dosage groups.Additionally,a normal control group and a sham-operation group were set up,with 8 rabbits in each group.Each treatment groups received the corresponding drugs via gavage for two consecutive weeks.HE staining was used to observe morphology of nucleus pulposus tissue,transmission electron microscopy was used to observe ultrastructure in nucleus pulposus cells,immunohistochemical staining was used to assess the expressions of Aggrecan and Collagen Ⅱ in nucleus pulposus tissue,Western blot was used to detect the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein in nucleus pulposus tissue.Results Compared with the sham-operation group,the model group showed a significant decrease in nucleus pulposus cells,disordered cell arrangement,reduced extracellular matrix,interrupted cell membrane continuity under transmission electron microscopy,organelle swelling,nuclear membrane disruption,partial chromatin loss,and positive expression of Aggrecan and Collagen Ⅱ in nucleus pulposus tissue decreased(P<0.01),while the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein significantly increased(P<0.01).Compared with the model group,the treatment groups showed an increased number of nucleus pulposus cells with orderly arrangement and more extracellular matrix,the ultrastructural damage of the cell membrane,organelle and nucleus in nucleus pulposus cells was partially restored under transmission electron microscopy,the positive expressions of Aggrecan and Collagen Ⅱ significantly increased in Bushen Huoxue Prescription medium-and high-dosage groups and the ibuprofen group(P<0.05,P<0.01),while the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein significantly decreased(P<0.05,P<0.01).Conclusion Bushen Huoxue Prescription may delay intervertebral disc degeneration of the model rabbit by inhibiting the expressions of p-RIPK1,p-RIPK3 and p-MLKL protein in nucleus pulposus cells,and promoting the generation of extracellular matrix components Aggrecan and Collagen Ⅱ.

Objective To observe the effects of Bushen Huoxue Prescription on pressure-induced necroptosis in human nucleus pulposus cells and the expressions of RIPK1/RIPK3/MLKL pathway;To explore its potential mechanism in delaying intervertebral disc degeneration.Methods Human primary nucleus pulposus cells were cultured in vitro,and a model of nucleus pulposus cell degeneration was established using continuous load pressure method.After modeling,the nucleus pulposus cells were divided into model group,Bushen Huoxue Prescription group and inhibitor group,blank serum,Bushen Huoxue Prescription containing serum and necroptotic apoptosis inhibitor(Nec-1)intervention were administered,respectively.Normal group nucleus pulposus cells were cultured routinely.AO/EB fluorescence dual staining method was used for detecting cell apoptosis,flow cytometry was used to detect the necroptosis rate of nucleus pulposus cells,Western blot was used to detect the protein expressions of p-receptor interacting protein kinase(RIPK)1,p-RIPK3 and p-mixed lineage kinase domain like protein(MLKL),RT-qPCR was used to detect the mRNA expressions of RIPK1,RIPK3 and MLKL.Results Compared with the normal group,the model group showed more red fluorescence under AO/EB staining of nucleus pulposus cells,which were round and condensed,the necroptosis rate of nucleus pulposus cells increased(P<0.05),the protein expressions of p-RIPK1,p-RIPK3 and p-MLKL increased(P<0.05,P<0.01),while there was no significant difference in RIPK1 mRNA expression(P>0.05),and RIPK3 and MLKL mRNA expression increased(P<0.01).Compared with the model group,Bushen Huoxue Prescription group and the inhibitor group had less red condensed chromatin in the nucleus pulposus cells,Bushen Huoxue Prescription group had a lower rate of necroptosis(P<0.05),while the inhibitor group showed a decreasing trend in necroptosis rate(P>0.05),the protein expressions of p-RIPK1,p-RIPK3 and p-MLKL decreased in Bushen Huoxue Prescription group and the inhibitor group(P<0.05,P<0.01),while there was no significant difference in RIPK1 mRNA expression(P>0.05),and RIPK3 and MLKL mRNA expressions decreased(P<0.01).Conclusion Bushen Huoxue Prescription can alleviate pressure-induced damage to nucleus pulposus cells and inhibit necroptosis,thereby slowing the progression of intervertebral disc degeneration.Its mechanism may be related to the RIPK1/RIPK3/MLKL pathway mediated necroptosis.

Objective To evaluate the safety and efficacy of valve-in-valve transcatheter mitral valve replacement(ViV-TMVR)in patients with bioprosthetic valve degeneration who are at high surgical risk.Methods This study is a multi-center,retrospective cohort analysis of 20 consecutive patients who underwent transseptal ViV-TMVR using the Edwards SAPIEN 3 transcatheter heart valve(THV).The primary endpoints include technical success and procedural success,both defined according to the Mitral Valve Academic Research Consortium(MVARC)criteria,as well as mortality and functional change assessed based on New York Heart Association(NYHA)classification at 30-days and six months post-procedure.Clinical follow-up assessments are conducted at 30-days and six months.Results From February 2021 to October 2022,a total of 20 patients with symptoms of bioprosthetic valve degeneration were enrolled across nine sites in China.The patients had a mean age of(73.5±5.5)years,with 85.0％being females and 70.0％classified as NYHA class Ⅲ/Ⅳ.The study achieved a 100.0％technical success rate and a 90.0％procedural success rate finally.All patients remained alive during the 30-day follow-up period.However,six months post-intervention,two patients(10.0％)were re-hospitalized due to heart failure,and sadly,one of them(5.0％)died.None of the patients reported any adverse events related to ViV-TMVR during the follow-up period.Notably,there was a significant improvement in NYHA class compared to baseline(P=0.0004)at six-month follow-ups.Conclusions The transseptal ViV-TMVR technique proved to be highly successful and was associated with significant improvement in NYHA class function.These findings strongly suggest that it serves as a safe and efficient treatment alternative for high-risk patients suffering from bioprosthetic valve degeneration.

To formulate an expert consensus on the principles of preoperative hair removal and provide scientific guidance for standardized removal of hair before surgical procedures so as to reduce the incidence of surgical site infections.METHODS Led by the Hospital Management Institute of National Health Commission of the People's Republic of China,this consensus was reached with the joint efforts from the expects of relevant fields such as surgeries,interventional therapies,nursing,and infection prevention and control.The consensus facilitates the classification and evaluation of literatures by following the evidence grade formulated by Oxford Evidence-based Medicine Center and focuses on the association of preoperative hair removal with surgical site infection,it reaches the evidence grade of expert consensus and recommendation intensity by integrating with discussions on meetings and clinical experience of the expects from relevant fields.RESULTS A total of 6 items of consensus were reached by summarizing the latest evidence on the aspects including the indications for preoperative hair removal,tools,range,timing and places.CONCLUSION The consensus,to some extent,make supplements to and complete the exiting regulations and standards.It provides guidance for the medical institutions to carry out the preoperative hair removal.

Lung cancer poses a serious threat to global public health security.Chemotherapy,as the main strategy for cancer treatment,faces challenges such as high toxicity and drug resistance.Anticancer peptides have the potential of being developed into new anticancer drugs due to their advantages of broad-spectrum anticancer activity,rapid action,and difficulty in generating drug resistance,but they also face shortcomings such as weak activity and strong toxic side effects.The weakly acidic microenvironment of tumors(pH 6.5-6.8)provides a good idea for the design of anticancer peptides of high-efficiency and low-toxicity.Previously,we designed the acid-sensitive antibacterial peptide pHly-1 using the wolf spider(Lycosa singoriensis)toxin Lycosin-Ⅰ as a template.In this study,we found that pHly-1 also had acid-sensitive anticancer activity.Further alanine scanning analysis of pHly-1 was carried out,and we ob-tained a mutant pHTP-2 with better acid sensitivity,whose IC50(half maximal inhibitory concentration)against A549 cells was 15.68 μmol/L at pH 6.6 and was greater than 100 μmol/L at pH 7.4.At pH 6.6,pHTP-2 could act on various lung cancer cell lines and induce the death of A549 cells by rapid ly-sis;at pH 7.4,500 μmol/L pHTP-2 had weak toxicity to red blood cells(the hemolysis rate was ap-proximately 38％)and primary myocardial cells(the inhibition rate was 49.7％,with P＜0.05).Analy-sis of its charge,particle size,morphology,and secondary structure showed that at pH 6.6,the histidine in the sequence of pHTP-2 was protonated,increasing the positive charge(P＜0.01),decreasing the hy-drated particle size(P＜0.05)and forming an α-helical structure to induce membrane lysis of A549 cells.At pH 7.4,it was deprotonated,the positive charge decreases,a β-sheet structure was formed and self-aggregation occurred,limiting its effect on the A549 cell membrane and showing weak activity.In summary,pHTP-2 could respond to the weakly acidic microenvironment of tumors to exert selective cyto-toxic activity,effectively overcoming the shortcomings of anticancer peptides such as low efficiency and high toxicity.Our findings suggest that it is a high-quality lead molecule for anticancer drugs.

Objective This study aimed to provide an effective scientific basis for prevention and control of cockroaches on aircrafts by identifying cockroach-carried pathogens,and assess the insecticidal efficacy of gel bait mediated cockroach control on aircrafts,to provide technical guidance for aircraft disinsection.Methods Cassette-trapping was used to trap cockroaches,and the carried pathogens were detected using bacterial cultivation techniques.The gel bait mediated killing rate was calculated after 1,7,and 30 d by field application of gel bait.Results A total of 411 cockroaches were captured,and all were identified as Blattella germanica.26 strains of pathogenic bacteria were isolated from the trapped cockroaches.The killing rates of cockroaches were 58.8％-96.3％with 1-30 day application of gel bait.Statistically significant differences were observed in cockroach killing rates on different days(χ2=58.95,P<0.01).Conclusions B.germanica carry a large variety of pathogenic bacteria and opportunistic pathogens and are thus important infectious disease carriers.Gel bait agents have proven to be very effective against cockroaches on aircrafts.