Ribosomally synthesized and post-translationally modified peptides (RiPPs) are an important source of bioactive natural products. The cross-links between aromatic amino acid side chains (cyclophane cross-links) confer structural diversity and complexity. These cross-links are primarily catalyzed by two major types of enzymes: radical S-adenosylmethionine (rSAM) enzymes and cytochrome P450 enzymes. This review focuses on the diverse cyclophane cross-linking patterns introduced by rSAM and P450 enzymes during RiPP biosynthesis, and summarizes the similarities and differences between these enzymatic transformations, aiming to provide some insights for the discovery, engineering, and mechanistic study of this class of natural products.

Cytochrome P450 enzymes represent a class of heme-containing protease widely distributed across the biological kingdom. Endowed with a broad substrate scope, diverse catalytic reaction profiles, high regio- and stereoselectivity toward substrates, and mild catalytic conditions, these enzymes stand out as superior biocatalysts with good potential of application. As one of the primary producers of natural products, Streptomyces harbors a wealth of P450 enzymes and natural product biosynthetic gene clusters (BGCs) in its genome, making it a versatile treasure trove for the generation of bioactive small-molecule compounds. This review summarizes the catalytic reactions by Streptomyces-derived P450 enzymes in natural product biosynthesis and delineates the engineering strategies for addressing the practical application challenges of P450 enzymes, aiming to provide some reference and guidance for in-depth research on P450 enzymes and their applications.

Neurocritical care involves complex pathophysiological mechanisms, and its incidence is higher, injuries are more severe, and treatment is more challenging in high-altitude environments. This consensus, based on the latest domestic and international evidence-based medical data, establishes a standardized, goal-oriented framework for neurocritical care management applicable in high-altitude regions and nationwide. The consensus was developed following international standards for evidence quality assessment and underwent two rounds of Delphi expert consultation, resulting in 32 recommendation statements covering three parts: management systems, monitoring and assessment, and core strategies. Key updates include: advocating for the establishment of independent neurocritical care units and implementing precise tiered diagnosis and treatment based on the "Five Differences in Critical Care" concept; constructing a "trinity" multimodal brain monitoring system centered on cerebral blood flow, cerebral oxygenation, and brain function, emphasizing routine bedside transcranial Doppler ultrasound, cerebral oximetry, and continuous electroencephalography monitoring; shifting management strategies from mild hypothermia therapy to targeted temperature management, and defining the "446" target management pathway for the supercritical stage; emphasizing the assessment of static and dynamic cerebrovascular autoregulation functions through multimodal methods to achieve individualized optimal mean arterial pressure management; elevating cerebrospinal fluid management goals to the level of "glymphatic system" function maintenance; implementing a multidisciplinary collaborative, whole-process management model focusing on patients' long-term neurological functional outcomes; de-escalation criteria include multidimensional indicators such as recovery of brain structure, restoration of cerebrovascular autoregulation, improvement in cerebrospinal fluid dynamics, and reduction in biomarker levels; and integrating cutting-edge technologies like artificial intelligence into post-critical care management and rehabilitation planning. This consensus systematically integrates the entire process of neurocritical care management, reflecting the modern connotation of goal-oriented, dynamic, and multimodal integration in neurocritical care medicine. It aims to adapt to new trends such as deepening understanding of pathophysiological mechanisms, the integration of medicine and engineering, and the empowerment of artificial intelligence, thereby further advancing the discipline of critical care medicine.

OBJECTIVE To systematically compare mature experiences of comprehensive drug value assessment in typical countries/regions and to provide decision-making references for China to establish a scientific and standardized comprehensive drug value assessment system for medical-insured drugs. METHODS The literature analysis was used to systematically review drug value assessment frameworks in 11 representative countries/regions， namely the UK， Canada， Italy， Australia， Germany， France， South Korea， Japan， the United States， as well as Taiwan （China） and Hong Kong （China）. Comparisons were made across three dimensions： assessment entities， value dimension， and application of results. RESULTS &CONCLUSIONS In most countries/regions， independent technical assessment institutions have been established as part of the drug value evaluation system， with the involvement of multiple stakeholders （e.g.， the UK， Canada）. The mainstream drug value assessment frameworks have generally transcended the traditional core dimensions of safety， efficacy， and cost-effectiveness， exhibiting two major trends： the continuous expansion of assessment dimensions and stricter evidence requirements. Assessment outcomes are closely integrated with payment policies， ranging from providing technical advice for decision-making （e.g.， Italy， France） to directly determining reimbursement eligibility （e.g.， the UK， Germany）. The following recommendations are proposed for China： first， establish an evaluation mechanism featuring multi-stakeholder participation and separation of evaluation from decision-making. Second， develop a comprehensive evaluation framework integrating clinical， economic， patient， and societal value， emphasizing quantitative indicator exploration and real-world evidence application. Third， promote direct linkage between value-based tiering outcomes and medical insurance reimbursement decisions or access negotiations to balance patient benefits， fund sustainability， and industrial innovation.

Objective: To explore the association between meat consumption and anxiety symptoms in first year junior high school students in Yunnan Province, and to provide theoretical support for preventing and relieving anxiety symptoms in junior high school students. Methods: From October to December 2022, a random cluster sampling method was used to select 8 500 first year junior high school students from 11 counties in Yunnan Province as the survey subjects for a questionnaire survey. The study used Food Frequency Questionnaire and the Chinese version of the Depression Anxiety Stress Scale-21 (DASS-21) to assess the meat consumption and anxiety symptoms of junior high school students.The distribution differences in anxiety symptoms among first year junior high school students with different demographic characteristics were analyzed statistically by using the Chi-square test,and the association between meat consumption and anxiety symptoms in students was analyzed by using a generalized linear model. Results: The detection rate of anxiety symptoms was 48.47%. After controlling for demographic variables and confounding factors, the consumption of livestock meat, poultry meat, processed meat, cured meat, barbecued meat and raw skin meat was statistically significant with anxiety symptoms ( β =-0.05, 0.04, 0.04, 0.08, 0.14, 0.17, all P <0.05). Stratified by ethnicity, The consumption of livestock meat, cured meat and barbecue was statistically correlated with anxiety symptoms in Han adolescents ( β =-0.07, 0.14, 0.22 ); the consumption of processed meat and raw skin meat was statistically correlated with anxiety symptoms in ethnic minority adolescents ( β =0.08, 0.18) (all P <0.05). Conclusions There is a statistical association between meat comsumption and the risk of anxiety symptoms in first year junior high school students in Yunnan Province. Guidance on meat consumption should be strengthened to prevent the occurrence of anxiety symptoms.

Parkinson's disease （PD） is a chronic progressive neurodegenerative disorder primarily characterized by motor dysfunction. The main pathological features include the loss of dopaminergic neurons in the substantia nigra， abnormal aggregation of alpha-Synuclein （α-Syn）， and the formation of Lewy bodies. However， the exact mechanisms remain unclear. In recent years， the PD incidence has gradually increased， while current treatment methods are limited to symptom alleviation， incapable of halting disease progression， and prone to adverse effects， thus making it urgent to search for medicines effective for PD. Modern research indicates that the Kelch-like ECH-associated protein 1 （Keap1）/nuclear factor E₂ related factor 2 （Nrf2）/antioxidant response element （ARE） signaling pathway is closely related to oxidative stress， neuroinflammation， apoptosis， ferroptosis， and mitochondrial dysfunction， playing a crucial role in the pathophysiological development of PD. A large number of studies have further confirmed that traditional Chinese medicine （TCM） can regulate diseases through a holistic view of Syndrome differentiation and microscopic molecular pathways. With unique advantages， such as multiple targets， multiple pathways， and fewer adverse reactions， TCM provides a new strategy for PD treatment. This article elucidates the mechanism of the Keap1/Nrf2/ARE signaling pathway in the occurrence and development of PD， while summarizing the latest research on PD intervention by TCM monomers， active ingredients， and compounds， as well as acupuncture via the precise targeted regulation of the Keap1/Nrf2/ARE pathway， aiming to provide a reference for clinical medicine development to prevent and treat PD.

ObjectiveTo analyze the epidemiological characteristics of 8 major respiratory pathogens in influenza-like illness (ILI) cases with acute respiratory infections at fever clinics in Huangpu District, Shanghai from 2015 to 2024, and to provide a scientific basis for the prevention and treatment of respiratory diseases. MethodsA retrospective study was conducted in Huangpu District. Individuals meeting the case definition of ILI from 2015 to 2024 was registered. Their nasopharyngeal swabs were collected for pathogen detection. A total of 8 respiratory viruses were tested, including Influenza A virus (Flu A), Influenza B virus (Flu B), adenovirus (ADV), enterovirus/human rhinovirus (EV/HRV), human parainfluenza virus (HPIV), human coronavirus (HCoV), respiratory syncytial virus (RSV), and human metapneumovirus (HMPV). ResultsFrom 2015 to 2019, a total of 344 ILI cases were tested, of which 192 out of 344 cases (55.81%) were tested positive for single respiratory pathogen. From 2023 to 2024, 1 557 ILI cases were tested, with 572 out of 1 557 cases (36.74%) being positive for single pathogen. From 2023 to 2024, the positive rate of single pathogen in ILI cases was significantly lower than that in 2015‒2019 (χ²=42.66, P<0.001). Specifically, the positive rate of Flu A (χ²=74.43, P<0.001) decreased, while that of HPIV (χ²=8.66, P=0.003) increased, both with statistically significant differences. According to the seasonal pattern, the epidemic intensity of Flu A decreased in summer, while that of HPIV increased in summer and autumn. Demographic results showed statistically significant differences in the positive rates of EV/HRV between genders (χ²=22.38, P<0.001), with males exhibiting a higher positive rate than females. No statistically significant differences were identified in the positive rates of single pathogen among different age groups (χ²=4.42, P=0.110). Nevertheless, statistically significant differences were noted when comparing the positive rates of EV/HRV, Flu A, Flu B and HPIV across different age groups (P<0.05). EV/HRV was more commonly detected in the 15‒<25 age group (10.93%), while Flu A and HPIV had the highest positive rates in the ≥60 age group (21.24% and 4.77%). Flu B had the highest positive rate in the 25‒<60 age group (11.26%). 52.63% of cases with co-infections occurred during winter, with the primary pathogens involved being EV/HRV (9 cases) and HCoV (6 cases). The most prevalent combination of co-infection was Flu A with EV/HRV. ConclusionThe prevalence of respiratory pathogens among ILI cases from 2023 to 2024 exhibited notable fluctuations compared to that from 2015 to 2019. Therefore, influenza surveillance should be strengthened, and attention should also be paid to the prevalence of respiratory pathogens such as HPIV. These findings have profound implications for future research, surveillance, vaccine planning, and public health policy making.

OBJECTIVE To investigate the effect and mechanism of morin on alveolar bone resorption in periodontitis mice based on the silent information regulator 1 （SIRT1）/peroxisome proliferator-activated receptor γ coactivator-1α （PGC-1α）/nuclear factor-erythroid 2-related factor 2 （Nrf2） pathway. METHODS The mice were randomly divided into control group， model group， morin group （40 mg/kg）， SRT1720 （SIRT1 activator） group （5 mg/kg）， and morin+EX527 （SIRT1 inhibitor） group （40 mg/kg morin+7.5 mg/kg EX527）， with 18 mice in each group. Except for control group， mice in other groups were subjected to silk ligation to establish periodontitis model. After successful modeling， mice in each group were treated with corresponding medicinal solutions or normal saline intragastrically or intraperitoneally， once a day， for two consecutive weeks. After the last medication， serum levels of tumor necrosis factor-α （TNF-α）， interleukin （IL）-1β， IL-6 and IL-10 were measured. The distance between the cementoenamel junction and alveolar bone crest was determined， and bone volume fraction and bone mineral density were calculated. Pathological changes of periodontal tissue were observed， and the number of osteoclasts was measured. mRNA expressions of receptor activator of nuclear factor-κB ligand （RANKL） and osteoprotegerin （OPG） in periodontal tissue， the levels of malondialdehyde （MDA） and superoxide dismutase （SOD） as well as protein expressions of SIRT1， PGC-1α， and Nrf2 were determined. RESULTS Compared with model group， the alveolar bone resorption and inflammatory cell infiltration in the periodontal tissues of mice were improved in morin group and SRT1720 group. The serum levels of TNF-α， IL-1β and IL-6， the distance between cementoenamel junction and alveolar bone crest， the number of osteoclasts in periodontal tissue， RANKL mRNA expression and the MDA level were decreased， shortened and reduced significantly （ P ＜0.05）； however， serum level of IL-10， bone volume fraction and bone mineral density， OPG mRNA expression in periodontal tissue， SOD level and protein expressions of SIRT1， PGC-1α and Nrf2 were increased significantly （ P ＜0.05）. Compared with morin group， the above pathological changes were significantly aggravated in the morin+EX527 group； and the levels of quantitative indicators were markedly reversed （ P ＜0.05）. CONCLUSIONS Morin may inhibit alveolar bone resorption in periodontitis mice by activating the SIRT1/PGC-1α/Nrf2 pathway to reduce inflammatory reaction and oxidative stress.

ObjectiveTo investigate the effects of metformin on the immune functions of immature dendritic cells （imDCs） and the underlying mechanisms. MethodsMouse bone marrow-derived imDCs were treated with different concentrations of metformin. The working concentration and treatment time of metformin in this study were determined based on the results of cell apoptosis and cell viability assays. The effects of metformin on the phagocytic capacity of imDCs was evaluated using an antigen endocytosis assay. The expression of cluster of differentiation 205 （CD205）， the polymerization of filamentous actin （F-actin）， and the underlying regulatory mechanisms were investigated through flow cytometry， laser confocal fluorescence microscopy， and Western blot. ResultsThe working concentrations of metformin were 1， 2， 4 mmol/L for 24 h determined by the apoptosis and cell viability assays.Metformin significantly suppressed the phagocytic capacity of imDCs， down-regulated the expression of the mannose receptor CD205 on the cell surface， which was closely associated with phagocytic function； metformin inhibited the RhoA-ROCK1-LIMK1-Cofilin signaling pathway， which inhibited the polymerization of F-actin and disturbed its dynamic remodeling of imDCs. ConclusionMetformin can inhibit the expression of CD205 and disrupt the remodeling of F-actin， thereby suppressing the antigen-capturing capacity of imDCs.

ObjectiveTo investigate the efficacy of selective internal radiation therapy （SIRT） in patients with unresectable hepatocellular carcinoma， and to provide a reference for the selection of clinical treatment regimens. MethodsA retrospective analysis was performed for the clinical data of 73 patients with unresectable hepatocellular carcinoma who received yttrium-90 microsphere SIRT in Eastern Hepatobiliary Surgery Hospital from May 1， 2023 to September 1， 2024. According to tumor characteristics， physical status， liver reserve function， laboratory tests， and SIRT treatment strategy， the patients were divided into radiation segmentectomy group with 9 patients， conversion therapy group with 47 patients， and palliative treatment group with 17 patients. Based on the results of postoperative follow-up， modified Response Evaluation Criteria in Solid Tumors were used to assess radiographic images. A one-way analysis of variance was used for comparison of normally distributed continuous data between three groups， and the chi-square test was used for comparison of categorical data between three groups； the Logistic regression model was used to perform the multivariate analysis. ResultsThere was a significant difference in postoperative outcome between the radiation segmentectomy group， the conversion therapy group， and the palliative treatment group （χ²=30.060， P<0.001）. The disease control rate was 100.0% （9/9） in the radiation segmentectomy group， 83.0% （39/47） in the conversion therapy group， and 29.4% （5/17） in the palliative treatment group， with a significant difference between the three groups （χ²=19.575， P<0.001）， and there was also a significant difference in objective response rate between the three groups （χ²=17.749， P<0.001）. The multivariate Logistic regression analysis showed that the number of tumors （odds ratio ［OR］=0.085， 95% confidence interval ［CI］： 0.008 — 0.906， P=0.041） and combined targeted immunotherapy （OR=18.808， 95%CI： 1.704 — 207.616， P=0.017） were independent influencing factors for achieving complete response. ConclusionThe number of tumors is an independent influencing factor for the efficacy of SIRT and is an important basis for selecting different treatment goals. SIRT combined with targeted immunotherapy may achieve better efficacy.