Chinese hamster ovary (CHO) cells are the most established and versatile mammalian expression system for the large-scale production of recombinant therapeutic proteins, owing to their genetic stability, adaptability to serum-free suspension culture, and ability to perform human-like post-translational modifications. More than 70% of biologics approved by the U.S. Food and Drug Administration rely on CHO-based production platforms, underscoring their central role in modern biopharmaceutical manufacturing. Despite these advantages, CHO systems continue to face three persistent bottlenecks that limit their potential for high-yield, reproducible, and cost-efficient production: excessive metabolic burden during high-density culture, heterogeneity of glycosylation patterns, and progressive loss of long-term expression stability. This review provides an integrated analysis of recent advances addressing these challenges and proposes a forward-looking framework for constructing intelligent and sustainable CHO cell factories. In terms of metabolic regulation, excessive lactate and ammonia accumulation disrupts energy balance and reduces recombinant protein synthesis efficiency. Optimization of culture parameters such as temperature, pH, dissolved oxygen, osmolarity, and glucose feeding can effectively alleviate metabolic stress, while supplementation with modulators including sodium butyrate, baicalein, and S-adenosylmethionine promotes specific productivity (qP) by modulating apoptosis and chromatin structure. Furthermore, genetic engineering strategies—such as overexpression of MPC1/2, HSP27, and SIRT6 or knockout of Bax, Apaf1, and IGF-1R—have demonstrated significant improvements in cell viability and product yield. The combination of multi-omics metabolic modeling with artificial intelligence (AI)-based prediction offers new opportunities for building self-regulating CHO systems capable of dynamic adaptation to environmental stress. Regarding glycosylation uniformity, which determines therapeutic efficacy and immunogenicity, gene editing-based glycoengineering (e.g., FUT8 knockdown or ST6Gal1 overexpression) has enabled the humanization of CHO glycan profiles, minimizing non-human sugar residues and enhancing drug stability. Process-level strategies such as galactose or manganese co-feeding and fine control of temperature or osmolarity further allow rational regulation of glycosyltransferase activity. Additionally, in vitro chemoenzymatic remodeling provides a complementary route to construct human-type glycans with defined structures, though industrial applications remain constrained by cost and scalability. The integration of model-driven process design and AI feedback control is expected to enable real-time prediction and correction of glycosylation deviations, ensuring batch-to-batch consistency in continuous biomanufacturing. Long-term expression stability, another critical challenge, is often impaired by promoter silencing, chromatin condensation, and random genomic integration. Molecular optimization—such as the use of improved promoters (CMV, EF-1α, or CHO endogenous promoters), Kozak and signal peptide refinement, and incorporation of chromatin-opening elements (UCOE, MAR, STAR)—helps maintain durable transcriptional activity, while site-specific integration systems including Cre/loxP, Flp/FRT, φC31, and CRISPR/Cas9 can enable single-copy, position-independent gene insertion at genomic safe-harbor loci, ensuring stable, predictable expression. Collectively, this review highlights a paradigm shift in CHO system optimization driven by the convergence of genome editing, synthetic biology, and artificial intelligence. The transition from empirical optimization to rational, data-driven design will facilitate the development of programmable CHO platforms capable of autonomous regulation of metabolic flux, glycosylation fidelity, and transcriptional activity. Such intelligent cell factories are expected to accelerate the transformation from laboratory-scale research to industrial-scale, high-consistency, and economically sustainable biopharmaceutical manufacturing, thereby supporting the next generation of efficient and customizable biologics manufacturing.

Chinese hamster ovary (CHO) cells are the most established and versatile mammalian expression system for the large-scale production of recombinant therapeutic proteins, owing to their genetic stability, adaptability to serum-free suspension culture, and ability to perform human-like post-translational modifications. More than 70% of biologics approved by the U.S. Food and Drug Administration rely on CHO-based production platforms, underscoring their central role in modern biopharmaceutical manufacturing. Despite these advantages, CHO systems continue to face three persistent bottlenecks that limit their potential for high-yield, reproducible, and cost-efficient production: excessive metabolic burden during high-density culture, heterogeneity of glycosylation patterns, and progressive loss of long-term expression stability. This review provides an integrated analysis of recent advances addressing these challenges and proposes a forward-looking framework for constructing intelligent and sustainable CHO cell factories. In terms of metabolic regulation, excessive lactate and ammonia accumulation disrupts energy balance and reduces recombinant protein synthesis efficiency. Optimization of culture parameters such as temperature, pH, dissolved oxygen, osmolarity, and glucose feeding can effectively alleviate metabolic stress, while supplementation with modulators including sodium butyrate, baicalein, and S-adenosylmethionine promotes specific productivity (qP) by modulating apoptosis and chromatin structure. Furthermore, genetic engineering strategies—such as overexpression of MPC1/2, HSP27, and SIRT6 or knockout of Bax, Apaf1, and IGF-1R—have demonstrated significant improvements in cell viability and product yield. The combination of multi-omics metabolic modeling with artificial intelligence (AI)-based prediction offers new opportunities for building self-regulating CHO systems capable of dynamic adaptation to environmental stress. Regarding glycosylation uniformity, which determines therapeutic efficacy and immunogenicity, gene editing-based glycoengineering (e.g., FUT8 knockdown or ST6Gal1 overexpression) has enabled the humanization of CHO glycan profiles, minimizing non-human sugar residues and enhancing drug stability. Process-level strategies such as galactose or manganese co-feeding and fine control of temperature or osmolarity further allow rational regulation of glycosyltransferase activity. Additionally, in vitro chemoenzymatic remodeling provides a complementary route to construct human-type glycans with defined structures, though industrial applications remain constrained by cost and scalability. The integration of model-driven process design and AI feedback control is expected to enable real-time prediction and correction of glycosylation deviations, ensuring batch-to-batch consistency in continuous biomanufacturing. Long-term expression stability, another critical challenge, is often impaired by promoter silencing, chromatin condensation, and random genomic integration. Molecular optimization—such as the use of improved promoters (CMV, EF-1α, or CHO endogenous promoters), Kozak and signal peptide refinement, and incorporation of chromatin-opening elements (UCOE, MAR, STAR)—helps maintain durable transcriptional activity, while site-specific integration systems including Cre/loxP, Flp/FRT, φC31, and CRISPR/Cas9 can enable single-copy, position-independent gene insertion at genomic safe-harbor loci, ensuring stable, predictable expression. Collectively, this review highlights a paradigm shift in CHO system optimization driven by the convergence of genome editing, synthetic biology, and artificial intelligence. The transition from empirical optimization to rational, data-driven design will facilitate the development of programmable CHO platforms capable of autonomous regulation of metabolic flux, glycosylation fidelity, and transcriptional activity. Such intelligent cell factories are expected to accelerate the transformation from laboratory-scale research to industrial-scale, high-consistency, and economically sustainable biopharmaceutical manufacturing, thereby supporting the next generation of efficient and customizable biologics manufacturing.

Objective:To explore the feasibility of obtaining three-dimensional (3D) models of intraosseous and periosteal arteries of hallux phalanx using micro-arteriography with micro-CT scan.Methods:From January 2022 to April 2025, the Department of Orthopaedic, the 988th Hospital of the Joint Logistics Support Force of the Chinese PLA conducted a study on 7 fresh-frozen specimens of distal lower limb (right lower limb) from an 85-year-old male, and both lower limbs from an 82-year-old male, a 78-year-old female and a 66-year-old male in the Department of Human Anatomy & Histology and Embryology, Peking University School of Basic Medical Sciences. Red lead oxide powder (Pb 3O 4) was ground and filtered through a 300 mesh, and then mixed with turpentine at ratios of 1 g ∶ 1.5 ml, 1 g ∶ 1.0 ml, and 1 g ∶ 0.5 ml to prepare lead-based contrast agent suspensions. After thawing the specimens at room temperature, the suspensions were injected via the popliteal artery in ascending order of concentration. After injections, the specimens were fixed in 10% methanal for 2 weeks. The proximal and distal phalanges of the hallux, with the surrounding periosteum preserved intact, were then harvested. The harvested specimens were scanned using micro-CT at an ultimate resolution of 12 μm. Subsequently, Mimics Medical software was used to reconstruct 3D models of the intraosseous and periosteal arteries within the phalanges. Results:Periosteal arteries in the proximal phalanx were primarily distributed near the joint region. A consistently large trunk artery entered from plantar side, supplying most of the diaphysis and head. There was a rich periosteal arterial network on both sides of the distal phalanx, which communicates with each other through the arterial arch in the bone groove. However, trunk intraosseous artery could be absent. Intraosseous arteries in the proximal ends of both the proximal and distal phalanges originated from periosteal arteries. These formed an interconnected arteriosomes and coursed parallel to the articular surfaces.Conclusion:The micro-arteriography acquired by micro-CT scan effectively visualizes intraosseous and periosteal arteries and enables the reconstruction and analysis of 3D models of the arteriosomes. The characteristics of arteriolar distribution provide a theoretical basis for osteotomy or internal fixation procedures involving a hallux phalanx.

Objective:To analyze the short-term hospital-based transmission characteristics and gene variation of Carbapenem-Resistant Klebsiella pneumoniae (CRKP) by genome-wide technique to provide evidence for transmission control. Methods:The experimental strain was derived from all the CRKP isolated in Affiliated Hospital of North China University of Science and Technology from October 2022 to December 2023. Strain identification and drug susceptibility were tested with VITEK 2-Compact automatic bacterial identification drug susceptibility analyzer or disk method, and the results were interpreted through whole genome sequencing. The ST type, carbapenem resistance gene, virulence factor, and O serotype of the collected strains were analyzed.Results:Among the 115 strains of CRKP, 94 strains were isolated from the intensive care unit (ICU), accounting for 81.7%, and 21 strains were isolated from the non-intensive care unit (NICU), accounting for 18.3%. The 115 strains of CRKP can be divided into 11 ST types, of which ST11 type was the most (54.8%, 63/115), followed by ST15 type (22.6%, 26/115) and ST5492 type (15.7%, 18/115). Type ST5492 was a new clonal group in the region. The 115 strains of CRKP could be divided into 7 O serotypes, most of which were O2a type(32.2%,37/115), followed by O5 type(30.4%,35/115) and O1 type(27.8%,32/115). The resistance genes of carbapenem antibiotics showed that there were 107 strains carrying the blaKPC-2 gene, one strain with the blaNDM-1 gene, and one strain with both the blaKPC-2 and blaNDM-13 genes. Virulence genes were detected in 55 CRKP strains (47.8%, 55/115), among which six strains detected peg-344, iucA, iroB, rmpA, and rmpA2 virulence genes (5.2%, 6/115). Four virulence genes ( peg-344, iucA, rmpA, and rmpA2) were detected in 34 strains (29.6%, 34/115). Three virulence genes ( iucA, iroB and rmpA) were detected in two strains (1.7%, 2/115). Three virulence genes ( peg-344, iucA and rmpA) were detected in one strain (0.8%, 1/115). IucA and rmpA virulence genes were detected in 12 strains (10.4%, 12/115). KPC-2_ST11_O2a, KPC-2_ST15_O1 and KPC-2_ST5492_O5 were dominant clones, and their distribution was mainly in the intensive care unit. The whole genome sequence analysis showed that there were three dominant clones, among which ST11 clones were subdivided into three dominant O serotypes, all of which were mainly in the intensive care unit. Conclusion:The popular strain in the hospital of CRKP is a KPC-2_ST11 clone group carrying iucA, rmpA/rmpA2, with cross-department transmission and mutation. ST5492 is a newly-launched clone type. The intensive care unit of hvKP carrying five virulence genes, including peg-344, should be alert to the epidemic risk of CR-hvKP outbreak.

Objective:To analyze the carriage status, subtype distribution and flanking gene sequence characteristics of oxacillinases (OXA enzyme) in 241 clinical strains of Pseudomonas aeruginosa, and assess their roles in the drug resistance of Pseudomonas aeruginosa and ability to horizontally transfer across species. Methods:Clinical P. aeruginosa isolates were collected from four hospitals in Sanya, Tangshan, Zhangjiakou, and Beijing. The prevalence of oxacillinases and their flanking gene sequences was analyzed by whole-genome sequencing (NGS) and bioinformatic approaches. Results:A total of 241 isolates of P. aeruginosa were gathered, and 35 blaOXA subtypes were identified through screening of 252 blaOXA genes. These genes were classified into three subfamilies: blaOXA-50-like (241, 95.6%), blaOXA-1-like (9, 3.6%) and blaOXA-10-like (2, 0.8%). Among these, 11 subtypes (11, 31.4%) were novel blaOXA subtypes. Nine of these belonged to the blaOXA-50-like subfamily and were designated as blaOXA-1244, blaOXA-1245, blaOXA-1246, blaOXA-1250, blaOXA-1252, blaOXA-1253, blaOXA-1254, blaOXA-1255, and blaOXA-1256. The remaining two belonged to the blaOXA-10-like subfamily and were named blaOXA-1247 and blaOXA-1248. Compared to the amino acid sequence of OXA-10, the newly identified subtype OXA-1247 exhibited a mutation at position 117, where a valine was replaced by a leucine. This change was thought to improve the enzyme′s ability to hydrolyze carbapenems. In the analysis of the flanking sequences of the blaOXA genes, Class I integrons were identified in four bacterial strains. The variable regions of these integrons carried three distinct patterns of resistance gene cassettes: aac( 6′) -Ib-blaOXA-1247-ant( 3′′) -Ia, aac( 6′) -Ib-blaOXA-1248 and aac( 6′) -Ib- blaIMP-45-blaOXA-1-catB3. Among these, the strain BJ2326 carried a class I integron that was connected to the downstream IS CR1 element to form a composite class I integron structure, additionally carrying the resistance gene blaPER-1. Out of the 223 non-wild-type P. aeruginosa strains, 127 strains exhibited non-wild-type profiles to the four beta-lactam antibiotics MEM, CAZ, FEP, and TZP, with the combination of MEM+CAZ+FEP being the most prevalent, representing 57.0% of the total. Conclusions:The blaOXA genes in 241 clinical P. aeruginosa strains showed diversity. Some blaOXA genes had a co-transfer risk with the metallo-β-lactamase resistance gene blaIMP-45. Among the 11 newly discovered blaOXA subtypes, the new subtype OXA-1247 may have carbapenemase activity and potential for horizontal transfer.

Objective To explore the effects of Shenyuan Yiqi Huoxue Capsules on cardiopulmonary exercise function and quality of life in patients with ischemic cardiomyopathy.Methods Totally 66 patients with ischemic cardiomyopathy were divided into treatment group and control group using random number table method,with 33 cases in each group.Both groups received standardized Western medicine treatment,and the treatment group was additionally given Shenyuan Yiqi Huoxue Capsules,the control group was given Shenyuan Yiqi Huoxue Capsules simulator,three capsules per time,three times a day,orally.The observation period was 30 days.To evaluate the efficacy of TCM syndrome in two groups.The observation indicators included baseline data,TCM syndrome scores,cardiopulmonary exercise test detection indicators,MLHFQ score,SF-36 score,echocardiographic indicators,N-terminal pro-B-type natriuretic peptide(NT-pro BNP)and safety indicators.Results The total effective rate of the treatment group was 93.94%(31/33),while that of the control group was 78.79%(26/33).The treatment group was significantly better than the control group(P<0.05).Compared with before treatment,the TCM syndrome scores of the two groups of patients decreased(P<0.05),and after treatment,the TCM syndrome score of the treatment group was lower than that of the control group(P<0.05).Compared with before treatment,the peak oxygen uptake(peak VO2),anaerobic threshold(AT)and peak oxygen pulse(peak O2 pulse)of both groups of patients increased,while the carbon dioxide ventilation equivalent slope(VE/VCO2 slope)decreased(P<0.05).After treatment,the treatment group had higher peak VO2,AT and peak O2 pulse than the control group,while the VE/VCO2 slope was lower than the control group(P<0.05).Compared with before treatment,both groups of patients showed a decrease in MLHFQ score and an increase in SF-36 score(P<0.05);after treatment,the MLHFQ score in the treatment group was lower than that in the control group,and the SF-36 score was higher than that in the control group(P<0.05).Compared with before treatment,both groups of patients showed a decrease in left ventricular end systolic diameter,left ventricular end diastolic diameter and NT-pro BNP levels,while myocardial motion index and left ventricular ejection fraction increased(P<0.05);after treatment,the treatment group showed a decrease in left ventricular end systolic diameter,left ventricular end diastolic diameter and NT-pro BNP levels,while myocardial motion index and left ventricular ejection fraction increased(P<0.05).During the treatment period,no adverse reactions such as dizziness,nausea,vomiting or diarrhea were found in both groups of patients.Conclusion Shenyuan Yiqi Huoxue Capsules can significantly improve the clinical efficacy of ischemic cardiomyopathy patients,alleviate TCM symptoms,improve their cardiorespiratory function and quality of life.

Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

Objective:To investigate the relationship among seminal oxidation-reduction potential(nORP),sperm DNA frag-mentation(DFI)and semen parameters in patients with varicocele.Methods:Clinical data of 522 patients treated in the reproduc-tive andrology clinic of the Northern Theater General Hospital from November 2023 to December 2023 were retrospectively analyzed,in-cluding 435 men of childbearing age and 87 men of infertile age.The patients were divided into the varicocele group(n=116)and non-varicocele group(n=406)according to clinical diagnosis.The differences of seminal plasma nORP,DFI,sperm high DNA stain ability(HDS)and semen parameters were analyzed between the two groups.The relationship among general clinical data,seminal plasma nORP,semen parameters,DFI and HDS in patients with varicocele were further analyzed.According to the severity of varico-cele,the patients were divided into three groups,including mild,moderate and severe.And the differences of seminal plasma nORP and semen parameters,DFI and HDS among all groups were analyzed.The differences of seminal plasma nORP,semen parameters,DFI and HDS were compared between the varicocele and non-varicocele groups.Results:The total sperm count,sperm concentra-tion,progressive motility sperm percentage(PR％)and normal sperm morphology rate(NSMR)in patients with varicocele were sig-nificantly lower than those in control group(P＜0.05).And seminal plasma nORP,DFI and HDS in patients with varicocele were sig-nificantly higher than those in control group(P＜0.05).Seminal plasma nORP in patients with varicocele was significantly negatively correlated with total sperm,sperm concentration and NSMR(P＜0.05),and significantly positively correlated with DFI and HDS(P＜0.05).There were significant differences in nORP,total sperm count,sperm concentration,PR％,DFI and HDS among mild,moderate and severe varicocele groups(P＜0.05).Seminal plasma nORP,sperm concentration,PR％and DFI in severe group were significantly lower than those in mild and moderate groups(P＜0.05).Sperm count and HDS in severe group were significantly lower than those in mild group(P＜0.05).In infertile patients,seminal plasma nORP,DFI and HDS in varicocele group were significantly higher than those in control group(P＜0.05).And PR％in varicocele group was significantly lower than that in control group(P＜0.05).Conclusions:Seminal plasma nORP in patients with varicocele may be an important marker of oxidative stress affecting DFI and semen parameters.

Objective To understand the current situation of healthcare-associated infection(HAI)in China,pro-vide data support and decision-making basis for formulating scientific and effective strategies for HAI prevention and control.Methods A nationwide cross-sectional survey on HAI was conducted among various types and levels of medical institutions in China according to a unified protocol of bedside surveys and case investigations.Results In 2024,a total of 5 736 medical institutions and 2 751 765 patients were surveyed.Among them,34 889 HAI cases were identified,with a prevalence rate of 1.27％.The number of HAI episodes was 38 032,and case prevalence rate was 1.38％.The prevalence rate of HAI in medical institutions in different regions of China ranged from 0.66％to 2.35％.Among medical institutions of different scales,those with a bed capacity of ≥900 had the high-est incidence of HAI,reaching 1.65％.The most common infection site was the lower respiratory tract(44.66％),followed by the urinary tract(12.94％),surgical site(9.32％),upper respiratory tract(7.02％),and bloodstream infection(5.78％).The top 3 departments with the highest HAI rates were the general intensive care unit(10.02％),department of neurosurgery(5.51％),and department(group)of hematology(5.34％).A total of 23 238 strains of HAI pathogens were detected,with 10 714 strains(46.10％)from lower respiratory tract speci-mens.The top 5 detected strains were Klebsiella pneumoniae(14.76％),Pseudomonas aeruginosa(13.33％),Escherichia coli(12.79％),Acinetobacter baumannii(9.23％),and Staphylococcus aureus(7.88％).231 944 pa-tients underwent class Ⅰ incision surgery were monitored,with 1 647 cases experienced surgical site infection,and the prevalence rate of surgical site infection was 0.71％.The number of patients who should undergo pathogen de-tection(patients receiving therapeutic and therapeutic combined prophylactic antimicrobial agents)was 715 179,while the actual number was 480 492,with a pathogen detection rate of 67.18％.425 225 patients received patho-genic detection before treatment,with a detection rate of 59.46％.Conclusion The overall HAI prevalence in Chi-na is lower,showing disparities among medical institutions of different regions and scales.Therefore,precise imple-mentation of measures is necessary for HAI prevention and control,with a focus on high-risk institutions and high-risk departments,key areas,and critical procedures.All levels of medical institutions should continuously reduce the incidence of HAI by strengthening monitoring,standardizing the use of antimicrobial agents,and reinforcing basic HAI prevention and control measures.

Objective:To systematically evaluate the current status of research on the development of indicators for entrustable professional activities (EPAs) of residents in China.Methods:We searched the China National Knowledge Infrastructure, Wanfang Data, Airiti Library, PubMed, Embase, and Web of Science databases for literature on the development of EPA indicators for residents in China published between January 1, 2005 and February 28, 2025. Two researchers independently screened the literature and extracted data, followed by descriptive analysis. The quality of the studies was assessed using the Joanna Briggs Institute critical appraisal tool for expert opinion. Quantitative data were presented as medians (ranges) and qualitative data were presented as frequencies (percentages).Results:A total of eight articles were included, in which two general EPA indicator systems and six specialty-specific EPA indicator systems were developed for residents. The overall quality of the research was high, with the main shortcomings related to the methods used in the process of constructing the consensus indicators. The number of experts recruited ranged from 22 to 45, with 100.00% response rate, high authority coefficients (0.820-0.914), and high coordination coefficients (0.157-0.741). Most of the studies used literature reviews as one source for the indicator pool (8 studies, 100.00%), employed the Delphi method to reach consensus (6 studies, 75.00%), and provided inclusion criteria for the indicators (7 studies, 87.50%). However, only one study (12.50%) explored the practical application of the developed indicators, and none of the studies set indicator weights or conducted quality assessments. The number of EPA indicators developed ranged from 10 to 38 per study. The reporting of EPA indicators was included in most studies regarding titles (8 studies, 100.00%) and the expected levels of entrustment at various stages of training (6 studies, 75.00%), but the reporting on other aspects was lacking. Among the specialty-specific EPA indicators, 38.39% overlapped with the general EPAs indicators.Conclusions:The research on the development of EPA indicators for residents in China is still in its early stages, and there is room for improvement in methodological quality and reporting coverage. There is partial overlap between specialty-specific and general EPA indicators, failing to fully reflect the unique characteristics of different specialties.