OBJECTIVE To analyze the selection and rationales of comparators for pharmaceutical enterprises in their medical insurance access application， so as to provide a reference for promoting communication and consensus between enterprises and medical insurance authorities in this process. METHODS The application materials for drugs outside the catalogue that passed formal review published by the National Healthcare Security Administration from 2021 to 2025 were extracted， and then content analysis was used to systematically sort out relevant information of the declared drugs and comparators； the specific situations and rationales of pharmaceutical enterprises’ selection of comparators were analyzed. RESULTS A total of 1 341 declared drug documents were collected. Data analysis showed that 1 035 （77.18%） were submitted with positive comparators and 306 （22.82%） used blank comparators； 58 drugs （4.33%） took combination therapy as the reference， and 5 drugs （0.37%） referred to non-pharmacological （or non-single pharmacological） treatment regimens. Among competitive drugs declared by multiple enterprises， 50.00% of the enterprises submitted different comparators. A total of 4 basic conditions and 39 additional conditions were extracted as the rationales for selecting positive comparators. For blank comparators， 12 drug-related factors， 2 administrative factors， and 1 other factor were identified. More than 10% of the drugs did not state the rationale for comparator selection， and over 44% of drugs using blank comparators provided only one justification. CONCLUSIONS Pharmaceutical enterprises mainly select comparators based on their own interests in the medical insurance access application， and there are deficiencies in the adequacy and standardization of their selection basis and reasoning. It is recommended that enterprises follow the principled requirements of medical insurance authorities， and fully and normatively explain the reasons for selecting comparators in combination with the characteristics of their own products. Meanwhile， it is advisable to change the current open-ended statement form of selection reasons into a closed-ended answering mode， so as to highlight the priority of selection， standardize the declaration behavior of enterprises， and reduce communication divergences between the two parties.

The rupture of carotid vulnerable plaques is the core pathological basis for major cardiovascular and cerebrovascular events. However， the insufficient alignment between existing animal models and the clinical disease and syndrome characteristics of traditional Chinese and western medicine has limited research progress. In this study， biomedical databases in China and abroad were systematically searched， and the modeling mechanisms and evaluation systems of carotid vulnerable plaque animal models were systematically assessed based on diagnostic criteria of both traditional Chinese and western medicine. Analysis of the clinical correspondence indicated that existing animal models can be categorized into four types： simple high-fat diet， surgical induction combined with high-fat feeding， genetic engineering combined with high-fat feeding， and drug induction combined with high-fat feeding. Among these， the compound strategy of surgical induction combined with high-fat feeding has become the current mainstream approach， showing good concordance with western medicine. The study found that the double balloon injury rabbit model and the ApoE^-/- mouse carotid artery tandem constriction combined with high-fat feeding model demonstrated a high degree of clinical correspondence with both traditional Chinese and western medicine in terms of vulnerable plaque imaging and pathological features. Nevertheless， existing models still face significant technical limitations in faithfully simulating plaque pathology and in translating findings to clinical applications. To address these challenges， integrating complex comorbidity mechanism construction， multimodal dynamic mechanism monitoring， and collaborative evaluation systems of traditional Chinese and western medicine could enable the development of highly concordant carotid vulnerable plaque disease-syndrome combination animal models. Such models would provide a reproducible experimental platform for targeted drug development to regulate plaque stability and for individualized precision treatment， as well as a theoretical basis for innovation in clinical diagnostic and therapeutic strategies.

ObjectiveTo investigate the possible mechanism of Bushen Huoxue Granule （补肾活血颗粒， BHG） in treating Parkinson's disease （PD） from the perspecitve of dopamine （DA） homeostasis. MethodsSeventy-two mice were randomly divided into blank group， model group， madopar group and BHG low-， medium- and high-dose groups， with 12 mice in each group. Except for the blank group， all mice were administered intraperitoneal injections of 1-methyl-4-phenyl-1，2，3，6-tetrahydropyridine （MPTP） for 7 consecutive days to induce a PD model. On the day following the injection， BHG low-， medium- and high-dose groups were administered BHG at doses of 1.25， 2.5， and 5.0 mg/（g·d） by oral gavage， respectively， while the madopar group received madopar tablets at dose of 0.093 8 mg/（g·d） by oral gavage. The blank group and the model group were given 0.2 ml/10 g of distilled water by gavage. All treatments were given once daily for 14 days. Open field test， pole climbing test and grip test were used to evaluate the behavior of mice in each group. Immunohistochemistry was used to detect the expression of tyrosine hydroxylase （TH） in striatum. Nissl staining was used to detect the activity of striatal neurons. The contents of DA and 3,4-dihydroxyphenylacetic acid （DOPAC） in striatum were detected by ultra performance liquid chromatography tandem mass spectrometry. The number and volume of synaptic vesicles were observed by transmission electron microscope. The expression of vesicular monoamine transporter 2 （VMAT2） in striatum was detected by immunofluorescence. Western Blot was used to detect the expression of extracellular signal-regulated kinase （ERK）， phosphorylated ERK （p-ERK）， cAMP response element-binding protein （CREB）， phosphorylated CREB （p-CREB） and VMAT2 in striatum. ResultsCompared to the blank group， mice in the model group showed a significant decline in total distance and average speed in the open field test， along with an increase in total resting time； in the pole test， both the time required for the mice to turn completely downward （T-turn） and the total time taken to reach the bottom of the pole （T-total） were prolonged； forelimb grip strength was reduced； in the striatum， the mean optical density of TH， the average fluorescence intensity of VMAT2 protein， and DA content all decreased， while the number of striatal neurons was reduced， and the DOPAC/DA ratio was elevated； the levels of p-ERK/ERK， p-CREB/CREB， and VMAT2 in the striatum significantly decreased （P＜0.01）； transmission electron microscopy revealed that both the number and volume of synaptic vesicles in striatal neurons were markedly reduced. Compared to the model group， mice in the madopar group and BHG low-， medium- and high-dose groups showed significant improvements in all the above indicators （P＜0.05 or P＜0.01）. Compared to madopar group， the BHG high-dose group exhibited increased DA content and elevated p-CREB/CREB ratio in the striatum （P＜0.05）. Compared to the BHG low-dose group， the BHG high-dose group showed increased total distance and mean velocity， decreased total resting time， T-turn， and T-total， as well as enhanced forelimb grip strength； moreover， the average fluorescence intensity of VMAT2 protein， DA content， p-ERK/ERK， p-CREB/CREB， and VMAT2 levels in the striatum were all significantly elevated （P＜0.05 or P＜0.01）. ConclusionBHG may restore DA homeostasis and alleviate the damage of dopaminergic neurons by regulating ERK/CREB/VMAT2 signaling pathway.

Objective:To evaluate the value of a combined model based on primary lesion 18F-fluorodeoxyglucose ( 18F-FDG) PET/CT radiomics for predicting lymph node metastasis in non-small cell lung cancer (NSCLC) . Methods:A retrospective analysis was conducted on the clinical data of 203 NSCLC patients who underwent pre-treatment PET/CT imaging at Nanjing Drum Tower Hospital from June 2013 to July 2023. Patients were randomly assigned to the training set ( n=142) and the validation set ( n=61) at a ratio of 7∶3. A predictive model was developed in the training set, and its predictive performance and clinical application value were assessed in both the training and validation sets. Traditional PET/CT parameters and PET/CT radiomics features of the primary lesion were obtained by 3D-slicer software. Least absolute shrinkage and selection operator (LASSO), random forest, and extreme gradient boosting were performed to extract features. Support vector machine was used to construct a radiomics score (Radscore). Univariate and multivariate logistic regression analysis was used to predict the influencing factors of lymph node metastasis in NSCLC patients and to establish models. Predictive performance of the models was evaluated by receiver operator characteristic (ROC) curves and clinical application value was assessed by calibration curves and decision curve analysis (DCA) . Results:Among 203 NSCLC patients, 116 had lymph node metastasis, with 64 cases in the training set and 52 cases in the validation set. Three complementary classical machine learning methods were used for feature screening, and finally 10 radiomics features were obtained. The optimal threshold for Radscore-PET was 0.43 and the optimal threshold for Radscore-CT was 0.39. Univariate analysis showed that, sex ( OR=0.48, 95% CI: 0.24-0.95, P=0.036), tumor marker levels ( OR=3.81, 95% CI: 1.84-7.91, P<0.001), long diameter of tumor ( OR=2.56, 95% CI: 1.27-5.16, P=0.009), short diameter of tumor ( OR=3.73, 95% CI: 1.75-7.92, P=0.001), vacuolar sign ( OR=0.32, 95% CI: 0.12-0.86, P=0.024), ring-like metabolism ( OR=3.67, 95% CI: 1.33-10.13, P=0.012), maximum standardized uptake value (SUV max) ( OR=6.57, 95% CI: 3.03-14.25, P<0.001), metabolic tumor volume (MTV) ( OR=2.91, 95% CI: 1.43-5.92, P=0.003), total lesion glycolysis (TLG) ( OR=4.23, 95% CI: 2.08-8.59, P<0.001), Radscore-PET ( OR=21.93, 95% CI: 9.04-53.20, P<0.001) and Radscore-CT ( OR=13.72, 95% CI: 6.12-30.76, P<0.001) were all influencing factors for predicting lymph node metastasis in NSCLC patients. Multivariate analysis showed that, tumor marker levels ( OR=2.55, 95% CI: 1.11-5.90, P=0.028), vacuolar sign ( OR=0.26, 95% CI: 0.08-0.83, P=0.023), SUV max ( OR=5.94, 95% CI: 1.99-17.75, P=0.001), Radscore-PET ( OR=25.51, 95% CI: 5.92-110.22, P<0.001), and Radscore-CT ( OR=8.68, 95% CI: 2.73-27.61, P<0.001) were independent influencing factors for predicting lymph node metastasis in patients with NSCLC. Based on the above independent influencing factors, models were constructed: the traditional model (tumor marker levels, vacuolar sign, SUV max), the PET model (SUV max, Radscore-PET), the CT model (vacuolar sign, Radscore-CT), and the combined model (tumor marker levels, vacuolar sign, SUV max, Radscore-PET, Radscore-CT). ROC curve analysis showed that, the area under curve (AUC) of the traditional, PET, CT, and combined models in the training set were 0.75 (95% CI: 0.67-0.82), 0.90 (95% CI: 0.84-0.95), 0.85 (95% CI: 0.78-0.90), and 0.94 (95% CI: 0.88-0.97), respectively. The predictive value of the combined model was higher than that of the traditional model ( Z=5.01, P<0.001), the PET model ( Z=1.99, P=0.047), and the CT model ( Z=3.25, P=0.001). In the validation set, the AUCs for the traditional model, PET model, CT model, and combined model were 0.65 (95% CI: 0.52-0.77), 0.86 (95% CI: 0.74-0.93), 0.85 (95% CI: 0.73-0.93), and 0.90 (95% CI: 0.80-0.96), respectively. The predictive value of the combined model was superior to that of the traditional model ( Z=3.23, P=0.001). The sensitivity and specificity of the combined model in the training set were 84.37% and 91.03%, while in the validation set, the sensitivity and specificity were 82.61% and 94.74%, respectively. Calibration curves showed a good agreement between the predicted and actual probabilities in both the training and validation sets. DCA showed that the combined models had good discriminative ability in both the training and validation sets. Conclusions:Tumor marker levels, vacuolar sign, SUV max, Radscore-PET, and Radscore-CT are all independent influencing factors for predicting lymph node metastasis in patients with NSCLC. The combined model based on these factors demonstrates excellent predictive performance and clinical application value for predicting lymph node metastasis in NSCLC.

Objective To study the clinical characteristics and medication patterns of Wangbi Tablets in treating patients with knee osteoarthritis(KOA)in the real world and to analyze the advantages and specific features of Chinese patent medicines in treating advantage disease.Methods A prospective case registry study was conducted,registering 3 000 patients from 30 TCM and Western medicine hospitals across China from April 2019 to December 2021.Data on gender,age,BMI,Chinese medicine staging(CMS),K-L grading,medication duration,VAS score,medical history and combined medication were collected for descriptive analysis.Comparisons were made between different stages and between single-use and combined-use groups.The Apriori algorithm was used for association analysis of combined medications.Results A total of 2 999 patients were included,with 2 063 females(68.79%)and 936 males(31.21%).The average age was(56.89±8.90)years.The average BMI was(23.80±2.88)kg/m2.The proportion of patients in CMS I was 512(17.07%),with a VAS median score of 8,while the proportion of patients in CMS Ⅱ was 2 181(72.73%),with a VAS median score of 6.The proportion of patients in CMS Ⅲ was 306(10.20%),with a VAS median score of 3;316 cases(10.54%)were classified as K-L grade I,2 477 cases(82.59%)as grade Ⅱ,204 cases(6.80%)as grade Ⅲ,and 2 cases(0.07%)as grade Ⅳ.Medication analysis indicated that the single-use group(1507 cases,50.25%)was larger than the combined-use group(1 492 cases,49.75%).In terms of the number of drugs used in combination,one(39.01%)and two(38.14%)were the main types;in terms of medication types,combination therapy with Western medicine(62.27%)and simultaneous use of Western medicine and other Chinese materia medica(26.14%)were the main methods;the top three drugs with the highest frequency of combination use were glucosamine capsules,imrecoxib tablets and sodium hyaluronate injection.The top three drug combinations with the highest support were"Huoxue Zhishang Powder+imrecoxib tablets","glucosamine capsules+imrecoxib tablets"and"glucosamine capsules+sodium hyaluronate injection".Inter-group comparisons showed that the medication duration for Wangbi Tablets in CMS I was longer than in CMS Ⅱ and CMS Ⅲ(P<0.01).The proportion of patients on monotherapy in CMS I(62.11%)was higher than in CMS Ⅱ(46.54%)and CMS Ⅲ(56.86%)(P<0.001).Among patients in CMS I(16.41%)and CMS Ⅲ(21.24%),the highest proportion used one combined medication,whereas in CMS Ⅱ,the highest proportion was for those using two combined medications(20.50%).In all three groups,CMS I(19.53%),CMS Ⅱ(33.70%)and CMS Ⅲ(30.72%),the highest proportion of combined medications was Western medicine.Conclusion More than half of the patients treated KOA with Wangbi Tablets alone.Approximately one-fifth of the patients were in CMS I,with a median pain score of 8.The average duration of medication for patients in CMS I,CMS Ⅱ and CMS Ⅲ decreases,and there is no obvious pattern in the medication method at different stages;combination therapy is represented by"Huoxue Zhishang Powder+imrecoxib tablets"and"glucosamine capsules+imrecoxib tablets".

Objective To study the clinical characteristics and medication patterns of Wangbi Tablets in treating patients with knee osteoarthritis(KOA)in the real world and to analyze the advantages and specific features of Chinese patent medicines in treating advantage disease.Methods A prospective case registry study was conducted,registering 3 000 patients from 30 TCM and Western medicine hospitals across China from April 2019 to December 2021.Data on gender,age,BMI,Chinese medicine staging(CMS),K-L grading,medication duration,VAS score,medical history and combined medication were collected for descriptive analysis.Comparisons were made between different stages and between single-use and combined-use groups.The Apriori algorithm was used for association analysis of combined medications.Results A total of 2 999 patients were included,with 2 063 females(68.79%)and 936 males(31.21%).The average age was(56.89±8.90)years.The average BMI was(23.80±2.88)kg/m2.The proportion of patients in CMS I was 512(17.07%),with a VAS median score of 8,while the proportion of patients in CMS Ⅱ was 2 181(72.73%),with a VAS median score of 6.The proportion of patients in CMS Ⅲ was 306(10.20%),with a VAS median score of 3;316 cases(10.54%)were classified as K-L grade I,2 477 cases(82.59%)as grade Ⅱ,204 cases(6.80%)as grade Ⅲ,and 2 cases(0.07%)as grade Ⅳ.Medication analysis indicated that the single-use group(1507 cases,50.25%)was larger than the combined-use group(1 492 cases,49.75%).In terms of the number of drugs used in combination,one(39.01%)and two(38.14%)were the main types;in terms of medication types,combination therapy with Western medicine(62.27%)and simultaneous use of Western medicine and other Chinese materia medica(26.14%)were the main methods;the top three drugs with the highest frequency of combination use were glucosamine capsules,imrecoxib tablets and sodium hyaluronate injection.The top three drug combinations with the highest support were"Huoxue Zhishang Powder+imrecoxib tablets","glucosamine capsules+imrecoxib tablets"and"glucosamine capsules+sodium hyaluronate injection".Inter-group comparisons showed that the medication duration for Wangbi Tablets in CMS I was longer than in CMS Ⅱ and CMS Ⅲ(P<0.01).The proportion of patients on monotherapy in CMS I(62.11%)was higher than in CMS Ⅱ(46.54%)and CMS Ⅲ(56.86%)(P<0.001).Among patients in CMS I(16.41%)and CMS Ⅲ(21.24%),the highest proportion used one combined medication,whereas in CMS Ⅱ,the highest proportion was for those using two combined medications(20.50%).In all three groups,CMS I(19.53%),CMS Ⅱ(33.70%)and CMS Ⅲ(30.72%),the highest proportion of combined medications was Western medicine.Conclusion More than half of the patients treated KOA with Wangbi Tablets alone.Approximately one-fifth of the patients were in CMS I,with a median pain score of 8.The average duration of medication for patients in CMS I,CMS Ⅱ and CMS Ⅲ decreases,and there is no obvious pattern in the medication method at different stages;combination therapy is represented by"Huoxue Zhishang Powder+imrecoxib tablets"and"glucosamine capsules+imrecoxib tablets".

BACKGROUND:Currently,there is a lack of large sample studies to analyze the bone metabolism level of patients with femoral head necrosis of different etiologies and stages,which is not conducive to the development of better necrosis-promoting repair strategies. OBJECTIVE:To study the bone metabolism of patients with osteonecrosis of the femoral head with different etiologies and Association Research Circulation Osseous(ARCO)stages. METHODS:A retrospective study was performed on 401 patients diagnosed with osteonecrosis of the femoral head as the trial group,and 81 healthy subjects as the control group.The trial group could be divided into three groups according to different etiologies:steroid-induced osteonecrosis of the femoral head,alcoholic osteonecrosis of the femoral head and traumatic osteonecrosis of the femoral head,and were divided into stages Ⅱ/Ⅲ/Ⅳ according to different ARCO stages.Seven bone metabolism-related indicators of all subjects were collected,including bone metabolism-regulating hormone 25-hydroxyvitamin D and bone conversion markers:N-terminal propeptide of type Ⅰ procollagen,degradation product of type Ⅰ collagen,n-terminal middle molecular fragment of osteocalcin,general biochemical markers of bone metabolism:serum calcium,serum phosphorus,serum alkaline phosphatase.The bone metabolism levels of each group were compared and the independent factors associated with osteonecrosis of the femoral head were determined by binary Logistic regression analysis. RESULTS AND CONCLUSION:Compared with the control group,levels of degradation product of type Ⅰ collagen,N-terminal propeptide of type Ⅰ procollagen,n-terminal middle molecular fragment of osteocalcin,serum phosphorus and alkaline phosphatase in the trial group were significantly increased(all P＜0.05).Based on the presence or absence of the disease,according to binary Logistic regression analysis,degradation product of type Ⅰ collagen,N-terminal propeptide of type Ⅰ procollagen,and n-terminal middle molecular fragment of osteocalcin were independent factors associated with osteonecrosis of the femoral head.The levels of degradation product of type Ⅰ collagen and N-terminal propeptide of type Ⅰ procollagen in three groups of patients with different etiologies were higher than normal reference values.The bone metabolism-regulating hormone 25-hydroxyvitamin D and serum calcium in the alcoholic osteonecrosis of the femoral head group were higher than those in the other two groups(P＜0.05).The level of bone metabolism-regulating hormone 25-hydroxyvitamin D in steroid-induced and traumatic osteonecrosis of the femoral head groups was lower than the normal value.There were no significant differences in seven bone metabolism-related indicators in patients with ARCO stages Ⅱ,Ⅲ and Ⅳ osteonecrosis of the femoral head(all P＞0.05),but degradation product of type Ⅰ collagen and N-terminal propeptide of type Ⅰ procollagen in these three groups were higher than normal reference values.Bone metabolism-regulating hormone 25-hydroxyvitamin D in patients with ARCO stage Ⅱ and ARCO stage Ⅳ was lower than the normal reference value.It is concluded that the bone metabolism level of osteonecrosis of the femoral head patients was abnormal.The degradation product of type Ⅰ collagen and N-terminal propeptide of type Ⅰ procollagen of osteonecrosis of the femoral head patients with different etiologies and ARCO stages were all higher than the normal reference value,and they were in a state of high bone turnover.Degradation product of type Ⅰ collagen,N-terminal propeptide of type Ⅰ procollagen and n-terminal middle molecular fragment of osteocalcin may be risk factors for the pathogenesis of osteonecrosis of the femoral head.

OBJECTIVE To study the protective effect of saikosaponin b2(SSb2)on corticosterone(CORT)induced PC12 cell injury and its mechanism.METHODS ① PC12 cells were divided into the cell control group(24 h of culture with RPMI-1640 medium),CORT group(24 h of culture with CORT 100-800 μmol·L-1)and SSb2 group(24 h of culture with SSb2 1.5625,3.125,6.25,12.5,25,50 and 100 μmol·L-1).MTT assay was used to detect the cell survival rate.②PC12 cells were divided into the cell control group(24 h of culture with RPMI 1640 medium),model group(24 h of culture with CORT 400 μmol·L-1),and model+SSb2 group(3 h pretreatment with SSb2 1.5625,3.125,6.25,12.5 and 25 μmol·L-1,removal of the supernatant before cells were co-incubated with CORT 400 μmol·L-1 and corresponding concentrations of SSb2 for 24 h).MTT assay was used to detect the cell survival rate while micro-plate assay was used to detect the lactate dehydrogenase(LDH)leakage rate of PC12 cells.③PC12 cells were divided into the cell control group,model group and model+SSb2 12.5 μmol·L-1 group.AnnexinV-FITC/PI flow cytometry assay was used to detect PC12 cell apoptosis,ultra-perfor-mance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)cell metabonomics was used to detect metabolic profile changes and colorimetric assay was employed to detect the glutamic acid content and glutaminase activity in PC12 cells.RESULTS Compared with the cell control group,the cell viability decreased to(55±6)%(P<0.01)when the concentration of CORT was 400 μmol·L-1.When the concentration of SSb2 was higher than 50 μmol·L-1,there was significant toxicity to PC12 cells(P<0.01).②Compared with the cell control group,the cell survival rate was signif-icantly decreased(P<0.01),while the release rate of LDH was significantly increased(P<0.01)in the model group.Compared with the model group,the cell survival rate significantly increased(P<0.05,P<0.01),while the LDH release rate significantly decreased(P<0.01)in the model+SSb2 group.③ Com-pared with the cell control group,cell apoptosis was significantly increased in the model group(P<0.05).Compared with the model group,cell apoptosis was significantly decreased(P<0.05)in the model+ SSb2 group.Metabolomics results show that SSb2 significantly back-regulated nine differential metabo-lites of glutamate,creatine,N-acetylaspartate,L-tyrosine,citric acid,L-isoleucine,lactic acid,glutamine and choline.Further network analysis of the key metabolites regulated by SSb2 yielded five major metabolic pathways:D-glutamine and D-glutamate metabolism,phenylalanine,tyrosine and tryptophan biosynthesis,alanine,aspartate and glutamate metabolism,tyrosine metabolism and arginine biosynthesis.Compared with the cell control group,the content of glutamate and activity of glutaminase were significantly decreased in the model group(P<0.01).Compared with the model group,the content of glutamate(P<0.01)and activity of glutaminase(P<0.05)were significantly increased in the model+SSb2 group.CONCLUSION SSb2 has a neuroprotective effect on CORT-injured PC12 cells,and the mechanism of which is related to inhibition of apoptosis and regulation of metabolic disorders.

Background Improper settings of outdoor smoking points in public places may increase the risk of secondhand smoke exposure among the population. Conducting research on air pollution in and around smoking spots and related influencing factors can provide valuable insights for optimizing the setting of outdoor smoking points. Objective To investigate the influence of the number of smokers at outdoor smoking points and the distance on the diffusion characteristics of surrounding air pollutants, in order to optimize the setting of outdoor smoking points. Methods Surrounding the exhibition halls in the China International Import Expo (CIIE), two outdoor smoking points were randomly selected, one on the first floor (ground level) and the other on the second floor (16 m above ground), respectively. At 0, 3, 6, and 9 m from the smoking points in the same direction, validated portable air pollutant monitors were used to measure the real-time fine particulate matter (PM_2.5) and carbon dioxide (CO₂) concentrations for consecutive 5 d during the exhibition, as well as the environmental meteorological factors at 0 m with weather meters including wind speed, wind direction, and air pressure. An open outdoor atmospheric background sampling point was selected on each of the two floors to carry out parallel sampling. Simultaneously, the number of smokers at each smoking point were double recorded per minute. The relationships between the number of smokers, distance from the smoking points, and ambient PM_2.5 and CO₂ concentrations were evaluated by generalized additive regression models for time-series data after adjustment of confounders such as temperature, relative humidity, and wind speed. Results The median numbers of smokers at smoking points on the first and second floors were 6 [interquartile range (IQR): 3, 9] and 9 (IQR: 6, 13), respectively. Windless (wind speed <0.6 m·s⁻¹) occupied most of the time (85.9%) at both locations. The average concentration of ambient PM_2.5 at the smoking points (0 m) [mean ± standard deviation, (106±114) μg·m⁻³] was 4.2 times higher than that of the atmospheric background [(25±7) μg·m⁻³], the PM_2.5 concentration showed a gradient decline with the increase of distance from the smoking points, and the average PM_2.5 concentration at 9 m points [(35±22) μg·m⁻³] was close to the background level (1.4 times higher). The maximum concentration of CO₂ [(628±23) μmol·mol⁻¹] was observed at 0 m, and its average value was 1.3 times higher than that of the atmospheric background [(481±40) μmol·mol⁻¹], and there was no gradient decrease in CO₂ concentration with increasing distance at 0, 3, 6, and 9 m points. The regression analyses showed that, taking smoking point as the reference, every 3 m increase in distance was associated with a decrease of ambient PM_2.5 by 24.6 [95% confidence interval (95%CI): 23.5, 25.8] μg·m⁻³ (23.2%) and CO₂ by 54.1 (95%CI: 53.1, 55.1) μmol·mol⁻¹ (8.6%). Every one extra smoker at the smoking point was associated with an average increase of PM_2.5 and CO₂ by 2.0 (95%CI: 1.7, 2.8) μg·m⁻³ and 1.0 (95%CI: 0.7，1.2) μmol·mol⁻¹, respectively. The sensitivity analysis indicated that, under windless conditions, the concentrations of PM_2.5 and CO₂ at the smoking points were even higher but the decreasing and dispersion characteristics remained consistent. Conclusion Outdoor smoking points could significantly increase the PM_2.5 concentrations in the surrounding air and the risks of secondhand smoke exposure, despite of the noticeable decreasing trend with increasing distance. Considering the inevitable poor dispersion conditions such as windless and light wind, outdoor smoking points are recommended to be set at least 9 m or farther away from non-smoking areas.

Objective To analyze the relationship between microorganisms and endodontic disease by using 16S rDNA sequencing to compare the composition of the microbial community in the root canals of teeth with pulpitis and apical periodontitis.Methods Clinical samples were collected from teeth requiring root canal treatment.The to-tal DNA of the bacteria in the samples and the gene fragments of the V3-V4 highly variable region on the 16S rDNA fragments were amplified through PCR.After sequencing by NovaSeq,statistical and bioinformatic analysis,inclu-ding phylogenetic analysis,diversity analysis and analysis of group differences,were performed.Results In total,6 teeth with pulpitis and 7 teeth with apical periodontitis were collected,and a total of 8 510 OTUs were obtained after next-generation sequencing,and the analysis of bacterial diversity showed that the difference between pulpitis and apical periodontitis in terms of the composition of the bacterial flora was statistically significant(P＜0.05).In particular,the relative abundance of Proteobacteria,Acidobacteriota and Actinobacteriota phylum was significantly higher in the roots of teeth affected by pulpitis than apical periodontitis.The relative abundance of Bacteroidota phylum and Synergistota phylum was significantly higher in the root canals of teeth with apical periodontitis.Con-clusion There is a complex diversity of infecting microorganisms in the root canals of teeth affected by endodontic diseases.The microbial communities in the infected root canals of pulpitis and apical periodontitis show some differ-ences,and changes in the microbial composition of the root canals may be associated with the development of endo-dontic diseases.