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.

Background In 2021, chronic obstructive pulmonary disease (COPD) emerged as the forth leading cause of death in the world. However, the impact of air pollutants on COPD is still inconsistent across current studies. Objective To analyze the relationship between ambient sulfur dioxide (SO₂) exposure and hospital admissions for COPD in Lanzhou, and to examine the modified effects of SO₂ across different genders, age groups, and seasons. Methods A total of 20718 hospital admission records for COPD were collected from Lanzhou between 2016 and 2020, alongside synchronized data on SO₂ concentration and meteorological variables. A generalized additive model integrated with a distributed lag nonlinear model was used to assess the relationship and the lag effects between SO₂ exposure and COPD admissions. Potential confounders, including meteorological factors, day-of-the-week effect, and holidays, were controlled for, with a maximum lag period set at 7 d. Two-pollutant models and sensitivity analyses were conducted to ensure robustness. Results are expressed as relative risks (RR) with 95% confidence intervals (95%CI). Results During the study period, the average daily number of COPD admissions was 11.34±7.03. The average mass concentration of SO₂ was (23.72±12.35) μg·m⁻³. SO₂ exposure was positively correlated with COPD admissions; specifically, each 10 μg·m⁻³ increase in SO₂ concentration was associated with an RR of 1.440 (95%CI: 1.317, 1.573). Stratified analyses found that at a cumulative lag of 7 d, the RRs were higher among females, individuals aged ≥65 years, and during the cold season. Conversely, no significant increase in COPD admission risk related to SO₂ was observed during the warm season. For every 10 μg·m⁻³ increase in SO₂ concentration, the RR was 1.483 (95%CI: 1.311, 1.678) for females, 1.441 (95%CI: 1.311, 1.583) for those aged > 65 years， and 1.595 (95%CI: 1.313, 1.937) during the cold season. Conclusion Short-term exposure to ambient SO₂ exposure in Lanzhou is associated with an increased risk of COPD admission. The association is more pronounced among females, the elderly (aged> 65 years) and during the cold season.

Objective: To establish evidence-based, safe and efficient management of HIV-reactive blood donors by investigating safe and feasible assessment strategies for HIV-reactive blood donors based on routine blood screening data. Methods: The data of blood screening, supplementary testing, follow-up and CDC confirmation for HIV-reactive blood donors in our center from 2014 to 2024 were analyzed systematically to confirm HIV infection and identify infection status. Results: There were 1 235 samples (0.13%, 1 235/928 000) reactive in HIV blood screening over the 11-year period. A-mong them, 199 donors (16.11%) in asymptomatic HIV infection (HIV Ag/Ab++&HIV RNA+), 2(0.16%) as acute early HIV infection (HIV Ag/Ab+-&HIV RNA+) and 7(0.57%) as window-period infection (HIV RNA positive only) were confirmed. Donors with the result of HIV Ag/Ab+-&HIV RNA-(single-positive) were all excluded for HIV infection, while 1 in 6 HIV Ag/Ab++&HIV RNA-donors (double-positive) was confirmed to have HIV infection. When HIV Ag/Ab reagents were used continuously before and after the follow-up, it's observed in one reagent that the proportion of negative results in subsequent follow-up in single-positive donors who had negative results in the first sampling was significantly higher than the proportion of negative results in subsequent follow-up in those initially single-positive (P<0.05). But no significant difference was observed in another reagent (P>0.05). When reagents were changed in follow-up, the rate of singlepositive donors with negative results in the first sampling reached 96.7%, which was significantly higher than the negative rate of those without reagent changing in follow-up (P<0.05). Conclusion: Based on the serological and nucleic acid testing results of HIV blood screening, the confirmation of HIV infection and identification of infection status can be achieved accurately and efficiently. All HIV Ag/Ab+-&HIV RNA-donors were confirmed as false positive, and should be maintained their eligibilities for blood donation, but recommended to pass the retest before next donation. Using a different reagent for retesting helps improve the eligible rate. HIV Ag/Ab++&HIV RNA-donors should be deferred permanently due to the risk of true positivity.

Objective: To investigate the trends in incidence and mortality of thyroid cancer in Nantong City, Jiangsu Province from 2013 to 2022, so as to provide a basis for optimizing comprehensive regional prevention and control strategies. Methods: Data on incidence and mortality of thyroid cancer in Nantong City from 2013 to 2022 were collected via the Nantong Cancer Registration Reporting System. Crude incidence and mortality were calculated. The Chinese population-standardized incidence and Chinese population-standardized mortality were calculated using the standard age structure from the Fifth National Population Census in 2000. The average annual percent change (AAPC) was used to analyze the trends in incidence and mortality of thyroid cancer across different genders, age groups, and urban-rural areas from 2013 to 2022. Results: The crude incidence and Chinese population-standardized incidence in Nantong City rose from 5.79/100 000 and 4.36/100 000 in 2013 to 34.87/100 000 and 30.40/100 000 in 2022, respectively (AAPC=22.226%, 24.139%, both P<0.05). The crude mortality increased from 0.39/100 000 to 1.07/100 000 (AAPC=10.469%, P<0.05), while the trend for Chinese population-standardized mortality was not statistically significant (P>0.05). The Chinese population-standardized incidence and Chinese population-standardized mortality for females were 20.41/100 000 and 0.30/100 000, respectively, which were 3.28 times and 1.50 times those of males. The Chinese population-standardized incidence showed upward trends for both males and females (AAPC=22.840%, 24.592%, both P<0.05), while the trends for Chinese population-standardized mortality were not statistically significant (both P>0.05). From 2013 to 2022, the crude incidence in the age groups of 15-<45, 45-<65, and 65-<85 years, and the crude mortality in the age group of 65-<85 years showed upward trends (AAPC=27.808%, 21.756%, 13.365%, and 8.030%, all P<0.05), while trends in other age groups were not statistically significant (all P>0.05). The Chinese population-standardized incidence in urban areas was 16.96/105, which was 1.40 times that of rural areas. The Chinese population-standardized mortality in rural areas was 0.27/105, which was 1.29 times that of urban areas. From 2013 to 2022, the Chinese population-standardized incidence in both urban and rural areas and Chinese population-standardized mortality in rural areas showed upward trends (AAPC=17.264%, 27.758%, 6.387%, all P<0.05), while trend in Chinese population-standardized mortality in urban areas was not statistically significant (P>0.05). Conclusions From 2013 to 2022, the crude incidence, Chinese population-standardized incidence, and crude mortality of thyroid cancer in Nantong City all showed upward trends in the total population, males, and females, while the trend in Chinese population-standardized mortality was stable. There were differences in mortality trends between urban and rural areas: the trend in urban areas was stable, whereas the trend in rural areas was upward.

Objective : To explore the mediating effect of self-efficacy on family health and health literacy among middle-aged and elderly chronic diseases patients in rural areas, so as to provide a basis for developing targeted health literacy improvement strategies. Methods: Based on the publicly available 2021 "Survey of Chinese Residents' Psychology and Behavior" database, rural chronic diseases patients aged >45 years were selected as the study subjects. Data on demographic information, family type, and chronic diseases comorbidities were collected. The Chinese simplified Family Health Scale, General Self-Efficacy Scale, and Health Literacy Scale were used to assess family health, self-efficacy, and health literacy, respectively. Correlation analysis was employed to explore the relationships between variables, and the 4.1 Process program was used to analyze the mediating effect of self-efficacy on family health and health literacy. The Bootstrap method was applied to test the significance of the mediating effect. Results: A total of 449 participants were included, of whom 241 were male (53.67%) and 208 were female (46.33%). The majority (205 cases, 45.66%) were aged 60-<76 years. There were 168 cases (37.42%) with chronic disease comorbidities. The total score for family health was (37.96±6.25) points. The self-efficacy score was (27.28±5.40) points, the health literacy index was (27.72±8.08) points, and the health literacy proficiency rate was only 14.90% (67 patierts). Mediating effect analysis showed that family health could directly and positively influence health literacy, with a direct effect value of 0.090 (95%CI: 0.001-0.179). It could also indirectly and positively influence health literacy through self-efficacy, with a mediating effect value of 0.164 (95%CI: 0.099-0.234). The mediating effect accounted for 64.31% of the total effect. Conclusion Self-efficacy plays a positive mediating role between family health and health literacy among middle-aged and elderly chronic diseases patients in rural areas.

Objective: To understand the allocation and use of safety seats for preschool children and explore its related factors, so as to provide a scientific reference for promoting the usage of safety seats. Methods: A stratified random cluster sampling method was used to select 3 143 parents of preschool children aged 3 to 6 from six kindergartens in Shunyi District, Beijing from January 3 to 10, 2022. An online questionnaire survey was conducted to collect and evaluate the equipment and use of child safety seats in different characteristics of preschool children, as well as their scores of health beliefs. Multiple factor Logistic regression analysis was used to investigated the related factors of safety seat configuration and use. Results: The equipping rate and usage rate of safety seats for preschool children were 66.56% and 58.45%, respectively. The proportion of equipped and used safety seats for preschool children in core families (69.52%, 62.23%) were higher than that in large families (64.35%, 55.62%), only child families ( 72.39 %, 64.87%) were higher than non only child families (61.49%, 52.86%), and urban families (71.63%, 63.04%) were higher than rural families (52.31%, 45.51%) ( χ 2=9.23, 13.86; 41.72, 46.44; 101.96 ,76.97,all P <0.05) . As the educational level of parents ( χ 2 trend =154.23,98.76) and annual income of the family ( χ 2 trend =155.78,127.69) rised, the reporting rates of the equipped and used child safety seats in the family also increased(all P <0.05 ). There were statistically significant differences in the scores of different dimensions of health beliefs for the provision ( t =-20.22-18.16) and use ( t =24.32-24.17) of safety seats for preschool children(all P <0.05). After adjusting for child sex, child age, family annual income, parental education level, family type, whether the child was an only child, and place of residence，multivariate Logistic regression analysis showed that preschool children with higher perceived susceptibility score( OR =1.11, 1.08), higher self efficacy score( OR =1.23, 1.33), and higher suggestive factors score( OR =1.08, 1.12) were more likely to have and use safety seats in their families, while preschool children with higher perceived impairments score( OR =0.82, 0.80) were less likely to have and use safety seats in their families (all P <0.05). Conclusions The installation rate of child safety seats needs to be improved, and there is also a certain gap in their use after installation. Parents of preschool children should improve susceptibility and self efficacy to safety seat equipment and use, and perceptual barriers should be reduced.

ObjectiveTo establish a high-performance liquid chromatography（HPLC） for the quantitative analysis of multiple components in Gegen Qinlian tablets， and to comprehensively evaluate the quality of samples from different manufacturers by integrating chemical pattern recognition and technique for order preference by similarity to ideal solution（TOPSIS）， in order to provide a reference basis for quality evaluation and control of Gegen Qinlian tablets. MethodsHPLC was employed to determine the contents of 10 components in 28 batches of Gegen Qinlian tablets collected from 6 manufacturers， and taking the detection results as variables， SIMCA 14.1 and SPSS 26.0 were employed for cluster analysis（CA）， principal component analysis（PCA）， and orthogonal partial least squares-discriminant analysis（OPLS-DA） to identify key components affecting the quality. Then， TOPSIS analysis was employed to rank the quality of Gegen Qinlian tablets from the 6 manufacturers and establish a comprehensive quality evaluation method. ResultsA quantitative method for Gegen Qinlian tablets was established. After methodological validation， the method was found to be stable and reliable， and could be used for the quantitative analysis of this preparation. The contents of 3′-hydroxy puerarin， puerarin， 3′-methoxy puerarin， daidzein， coptisine hydrochloride， epiberberine， jatrorrhizine hydrochloride， berberine hydrochloride， palmatine hydrochloride and baicalin in 28 batches of samples were 3.58-7.35， 24.88-42.32， 4.20-9.36， 4.33-7.60， 2.52-6.44， 0.93-4.10， 0.58-3.05， 10.68-22.92， 0.82-4.82， 11.73-60.16 mg·g^-1， respectively. Among them， puerarin， berberine hydrochloride and baicalin all met the limit requirements for this preparation specified in the 2025 edition of the Pharmacopoeia of the People's Republic of China. CA and PCA clustered the 28 batches of samples into 5 categories， PCA extracted 2 principal components with a cumulative variance contribution rate of 90.588%， and OPLS-DA screened out 4 differential markers with variable importance in the projection（VIP） values>1.0， namely baicalin， 3′-hydroxy puerarin， coptisine hydrochloride and palmatine hydrochloride， which might be the main components affecting the quality of Gegen Qinlian tablets. TOPSIS analysis showed that the comprehensive score of each evaluation index（C_i） values of different manufacturers were different. Among them， the C_i of manufacturer B was ranked higher， indicating potentially superior quality， while the C_i of manufacturer A was ranked lower， suggesting potentially inferior quality. ConclusionThis study establishes a quantitative method for Gegen Qinlian tablets， and the content uniformity of the same manufacturer is good， while there are differences in the contents of active components among different manufacturers. Through the chemical pattern recognition analysis， it is found that the content differences of Gegen Qinlian tablets may be related to baicalin， 3′-hydroxy puerarin， coptisine hydrochloride and palmatine hydrochloride.

ObjectiveThis paper aims to investigate the protective effects of the Tanyu Tongzhi Youhua prescription（TYTZP） against myocardial ischemia/reperfusion injury in rats via regulation of the cyclic GMP-AMP synthase （cGAS）/stimulator of interferon genes （STING） signaling pathway. MethodsFifty-six 8-week-old male Sprague-Dawley （SD） rats were randomly divided into sham group， model group， ticagrelor group （32.4 mg·kg^-1）， RU320521 （RU.521cGAS inhibitors） group （5 mL·kg^-1）， groups of TYTZP with low dose （3.6 g·kg^-1）， medium dose （7.2 g·kg^-1）， and high dose （14.4 g·kg^-1）， with eight rats per group. The ticagrelor group and groups of TYTZP with different doses received pre-treatment for seven days according to their respective protocols. The RU.521 group received an intraperitoneal injection one hour before modeling. A rat model of the no-reflow phenomenon in myocardial ischemia/reperfusion injury was established by ligating the left anterior descending coronary artery in situ. Myocardial no-reflow area was determined by thioflavin staining. Histopathological morphology of myocardial tissue was observed via hematoxylin and eosin （HE） staining. Cardiac function was detected by echocardiography. Myocardial microcirculation function change was observed by using real-time myocardial contrast echocardiography. The myocardial enzyme levels in the serum were measured by serum biochemical analysis. The double-stranded DNA （dsDNA） levels were detected by using PicoGreen. The protein expression of cGAS， STING， and nuclear factor-κB （NF-κB） p65 in myocardial tissue was detected by Western blot. The levels of cardiac troponin Ⅰ （cTNⅠ）， cardiac troponin T （cTNT）， interleukin-6 （IL-6）， interleukin-1β （IL-1β）， and tumor necrosis factor-α （TNF-α） in the peripheral blood were measured by enzyme-linked immunosorbent assay （ELISA）. ResultsCompared with the sham group， the model group showed a significantly increased myocardial no-reflow area （P<0.01）. Myocardial fiber rupture and disarray and inflammatory cell infiltration were observed by HE staining. The ultrasound results indicated that left ventricular ejection fraction （LVEF） and left ventricular fractional shortening （LVFS） （P<0.01） were significantly decreased. Real-time myocardial contrast echocardiography showed that the peak time of myocardial blood perfusion was significantly prolonged （P<0.01）， and the levels of creatine kinase （CK）， creatine kinase isoenzyme （CK-MB）， lactate dehydrogenase （LDH）， cTNⅠ， cTNT， and dsDNA were significantly elevated （P<0.01）. Western blot results showed that the myocardial protein expressions of cGAS， STING， and NF-κB p65 were upregulated （P<0.01）. ELISA results showed that the inflammatory factors in the serum such as IL-6， IL-1β， and TNF-α were increased （P<0.01）. Compared with the model group， the group of the TYTZP significantly reduced the levels of myocardial enzyme， troponins， and dsDNA （P<0.01， P<0.05）， improved cardiac function and myocardial microcirculation， alleviated histopathological morphology and inflammatory infiltration， inhibited activation of the cGAS/STING pathway， reduced the expression of NF-κB p65 （P<0.01， P<0.05）， and inhibited inflammatory response. ConclusionThe TYTZP mitigates the no-reflow phenomenon in myocardial ischemia/reperfusion injury， and its mechanism is associated with inhibiting the activation of the cGAS/STING pathway and attenuating inflammatory responses.

ObjectiveThis paper aims to investigate the protective effects of the Tanyu Tongzhi Youhua prescription（TYTZP） against myocardial ischemia/reperfusion injury in rats via regulation of the cyclic GMP-AMP synthase （cGAS）/stimulator of interferon genes （STING） signaling pathway. MethodsFifty-six 8-week-old male Sprague-Dawley （SD） rats were randomly divided into sham group， model group， ticagrelor group （32.4 mg·kg^-1）， RU320521 （RU.521cGAS inhibitors） group （5 mL·kg^-1）， groups of TYTZP with low dose （3.6 g·kg^-1）， medium dose （7.2 g·kg^-1）， and high dose （14.4 g·kg^-1）， with eight rats per group. The ticagrelor group and groups of TYTZP with different doses received pre-treatment for seven days according to their respective protocols. The RU.521 group received an intraperitoneal injection one hour before modeling. A rat model of the no-reflow phenomenon in myocardial ischemia/reperfusion injury was established by ligating the left anterior descending coronary artery in situ. Myocardial no-reflow area was determined by thioflavin staining. Histopathological morphology of myocardial tissue was observed via hematoxylin and eosin （HE） staining. Cardiac function was detected by echocardiography. Myocardial microcirculation function change was observed by using real-time myocardial contrast echocardiography. The myocardial enzyme levels in the serum were measured by serum biochemical analysis. The double-stranded DNA （dsDNA） levels were detected by using PicoGreen. The protein expression of cGAS， STING， and nuclear factor-κB （NF-κB） p65 in myocardial tissue was detected by Western blot. The levels of cardiac troponin Ⅰ （cTNⅠ）， cardiac troponin T （cTNT）， interleukin-6 （IL-6）， interleukin-1β （IL-1β）， and tumor necrosis factor-α （TNF-α） in the peripheral blood were measured by enzyme-linked immunosorbent assay （ELISA）. ResultsCompared with the sham group， the model group showed a significantly increased myocardial no-reflow area （P<0.01）. Myocardial fiber rupture and disarray and inflammatory cell infiltration were observed by HE staining. The ultrasound results indicated that left ventricular ejection fraction （LVEF） and left ventricular fractional shortening （LVFS） （P<0.01） were significantly decreased. Real-time myocardial contrast echocardiography showed that the peak time of myocardial blood perfusion was significantly prolonged （P<0.01）， and the levels of creatine kinase （CK）， creatine kinase isoenzyme （CK-MB）， lactate dehydrogenase （LDH）， cTNⅠ， cTNT， and dsDNA were significantly elevated （P<0.01）. Western blot results showed that the myocardial protein expressions of cGAS， STING， and NF-κB p65 were upregulated （P<0.01）. ELISA results showed that the inflammatory factors in the serum such as IL-6， IL-1β， and TNF-α were increased （P<0.01）. Compared with the model group， the group of the TYTZP significantly reduced the levels of myocardial enzyme， troponins， and dsDNA （P<0.01， P<0.05）， improved cardiac function and myocardial microcirculation， alleviated histopathological morphology and inflammatory infiltration， inhibited activation of the cGAS/STING pathway， reduced the expression of NF-κB p65 （P<0.01， P<0.05）， and inhibited inflammatory response. ConclusionThe TYTZP mitigates the no-reflow phenomenon in myocardial ischemia/reperfusion injury， and its mechanism is associated with inhibiting the activation of the cGAS/STING pathway and attenuating inflammatory responses.

ObjectiveTo investigate the effect and mechanism of modified Sini San in ameliorating intestinal mucosal barrier by observing its effects on short chain fatty acids （SCFAs） and high mobility group protein B1 （HMGB1）/receptor of advanced glycation end products （RAGE） signaling pathways in chronic stress rats. MethodsThe 50 male SD rats were randomly divided into control group，model group，low-dose modified Sini San group （7.34 g·kg^-1·d^-1），high-dose modified Sini San group （14.68 g·kg^-1·d^-1），and Fructo-oligosaccharides group （3.15 g·kg^-1·d^-1），with 10 rats in each group. Except for the control group，all other groups were subjected to chronic unpredictable stress/social isolation to create a chronic stress model for 6 weeks. After 4 weeks of modeling，each treatment group was given corresponding drugs by gavage for 2 weeks while modeling. The control group and model group were given the same volume of physiological saline. The effects of Modified Sini San on behaviors，body weight，Bristol score in feces and fecal moisture content in chronic stress rats were observed. Hematoxylin and eosin （HE） staining was used to observe the pathological changes in the cecum. The content of SCFAs in the cecal contents of rats were detected by Gas chromatography-mass spectrometry （GC-MS）. Immunohistochemistry and Western blot were used to detect the expression of HMGB1/RAGE pathway related proteins in cecal tissue. The levels of ZO-1，Occludin，and Claudin-1 in the cecal tissue were detected by enzyme linked immunosorbent assay （ELISA）. ResultsCompared with the model group，the sucrose preference rate，total distance traveled and the number of grid crossings in the open field test of rats in the low-dose modified Sini San group were obviously increased （P<0.05， P<0.01），and the immobility time in the open field test and the immobility time in the forced swimming test of rats in the low-dose and high-dose modified Sini San groups were obviously reduced （P<0.05， P<0.01）. Meanwhile，the Bristol score and fecal moisture content of rats in the low and high dose groups of modified Sini San were obviously increased （P<0.05）. The low-dose group of modified Sini San had intact mucosal layer structure in the cecal tissue and reduced infiltration of inflammatory cells. The content of SCFAs in the cecal contents increased，with a obviously increase in the content of acetic acid，propionic acid，butyric acid，and isovaleric acid （P<0.05， P<0.01） and the expression levels of HMGB1，RAGE，Toll-like receptor 2（TLR2），Toll-like receptor 4（TLR4），tumor necrosis factor-α（TNF-α），and nuclear factor kappa-B p65（NF-κB p65） proteins in cecal tissue were significantly decreased （P<0.05， P<0.01） in low-dose group of modified Sini San. Meanwhile，the contents of ZO-1，Occludin，and Claudin-1 in the cecal tissue were obviously increased （P<0.01） in low-dose group of modified Sini San. ConclusionModified Sini San can improve the function of intestinal mucosal barrier in chronic stress rats by increasing the content of SCFAs in the intestine and inhibiting the HMGB1/RAGE pathway.