ObjectiveTo evaluate the clinical efficacy and economic value of the Jiangsu Traditional Chinese Medicine （TCM） Diagnosis and Treatment Protocol for Dominant Diseases （abbreviated as the Diagnosis and Treatment Protocol） in adult patients with non-severe community-acquired pneumonia （CAP） based on real-world clinical data. MethodsA retrospective real-world cohort study was conducted using electronic medical records of adult patients hospitalized for non-severe CAP from September 1st， 2023 to December 31st， 2024 across 10 TCM hospitals in Jiangsu province. Patients were classified into an exposure group and a non-exposure group based on whether they received Chinese herbal medicine （CHM） according to the Diagnosis and Treatment Protocol. The non-exposure group received only conventional western medicine， while the exposure group additionally received differentiated CHM for at least five consecutive days. Outcomes were compared between two patient groups， including cough resolution rate， sputum resolution rate （assessed by volume， color， and consistency）， incidence of abnormal C-reactive protein （CRP）， incidence of abnormal white blood cell （WBC） count， and radiographic resolution rate of pulmonary infiltrates on chest imaging. Multivariable logistic regression was performed to identify factors influencing clinical efficacy. Subgroup analyses were conducted according to age， gender， smoking status， history of hypertension， and pneumonia severity score （CURB-65）， and the efficacy of treatment for cough and sputum was analyzed within each subgroup. Cost-effectiveness analysis was conducted using cough resolution rate as the outcome measure， evaluating the pharmacoeconomics of the two groups. ResultsA total of 1688 patients were included with 1293 in the exposure group and 395 in the non-exposure group. Compared to the non-exposure group， the exposure group demonstrated significantly higher resolution rates of cough， sputum volume， color， and consistency， as well as a significantly lower incidence of abnormal CRP （P＜0.05）. No statistically significant difference was observed between the groups in terms of abnormal WBC count and radiographic resolution rate of pulmonary infiltrates （P＞0.05）. Logistic regression analysis showed that the cough resolution rate in the exposure group was 1.83 times that of the non-exposure group， while the probabilities of resolution in sputum volume， color， and consistency were 1.37， 2.09， and 1.56 times those of the non-exposure group， respectively （P＜0.05）. Subgroup analyses showed that the exposure group achieved significantly higher cough resolution rates across most subgroups except for populations with a CURB-65 score ≥2 or those with a history of hypertension （P＜0.05）. Specifically， among females， patients aged ≥18 and ＜65 years， non-smokers， those without hypertension， and those with a CURB-65 score of 0， the exposure group showed a higher cough resolution rate than the non-exposure group （P＜0.05）. From an economic perspective， total hospitalization cost， length of stay， antibiotic cost， and CHM cost all differed significantly between groups （P＜0.05）. The cost-effectiveness ratio （CER） was 10,788.80 CNY/case in the exposure group， while 22,513.80 CNY/case in the non-exposure group. This implies that， compared with the exposure group， the non-exposure group incurred an additional 17,302.27 CNY to achieve one case of cough resolution. When the willingness-to-pay threshold ranged from 0 to 50,000 CNY， the probability of economic advantage was consistently higher in the exposure group than in the non-exposure group. ConclusionOn the basis of conventional western medicine， the addition of CHM in accordance with the Diagnosis and Treatment Protocol can effectively improve clinical symptoms， reduce inflammatory markers， promote clinical recovery， and is more cost-effective in treating adults with non-severe CAP.

ObjectiveTo observe the real‑world effectiveness and economic outcomes of Weishi Qingjin Formula （苇石清金方， WQF） in the treatment of adult community‑acquired pneumonia （CAP） with phlegm‑heat obstructing the lung syndrome. MethodsBased on a multicenter， real-world retrospective cohort study， clinical data were collected from hospitalized adult patients diagnosed with non‑severe CAP and phlegm‑heat obstructing the lung syndrome in 10 traditional Chinese medicine （TCM） hospitals in Jiangsu province. Patients were divided into an exposure group （those who received oral WQF） and a non‑exposure group （those who did not）. The following outcomes were compared between the two groups before and after treatment， which were remission rates of clinical symptoms including cough， expectoration （sputum volume， color， consistency）， and chest pain， levels of inflammatory markers including C‑reactive protein （CRP） and white blood cell count （WBC）， and the rate of pulmonary inflammatory absorption on chest CT. Subgroup analyses were performed based on age， gender， smoking status， presence of hypertension， and the severity of community-acquired pneumonia （CURB‑65） score， comparing the two groups in terms of cough remission rate， chest pain remission rate， and chest CT absorption rate. For health economic evaluation， cost‑effectiveness analysis was used to calculate the cost‑effectiveness ratio （CER） and incremental cost‑effectiveness ratio （ICER）. Univariate sensitivity analysis and probabilistic sensitivity analysis were performed to test the robustness of the results. ResultsA total of 647 patients in the exposure group and 1491 patients in the non-exposure group were included in the final statistical analysis. There was no statistically significant difference in length of hospital stay， gender， marital status， smoking history， bronchoscopy history， and comorbidities between the groups （P＞0.05）， but age， CURB-65 score， and antibiotic use. The exposure group had significantly higher remission rates of cough and sputum consistency than the non-exposure group （P＜0.05）. After adjusting for confounders using propensity score matching and logistic regression， the cough remission rate in the exposure group was 1.49 times that of the non-exposure group （P＜0.01）. No significant difference was observed between groups in the reduction rates of CRP and WBC， and in the rate of pulmonary inflammatory absorption on chest CT （P＞0.05）. Subgroup analyses revealed that the cough remission rate in the exposure group was significantly better than that in the non-exposure group except for patients aged ≥65 years， smokers， hypertensive patients， those using other type antibiotics or not using antibiotics， and those with a CURB-65 score ≥1 （P＜0.05）. Among smokers， the chest pain remission rate in the exposure group was 4.38 times that of the non-exposure group （P＜0.01）. No significant difference in chest CT absorption rate was found between groups across subgroups of gender， age， hypertension status， or antibiotic type （P＞0.05）. In terms of economic evaluation， CER was 10,877.60 CNY/case in the exposure group and 16,773.10 CNY/case in the non-exposure group. Compared to the exposure group， the non-exposure group incurred an additional 15,034.26 CNY to achieve one case of cough resolution， indicating a more favorable cost-effectiveness profile. Probabilistic sensitivity analysis yielded results consistent with the cost-effectiveness analysis， confirming the robustness of the findings. ConclusionWQF demonstrates significant efficacy in improving cough symptoms in the treatment of adult CAP with phlegm-heat obstructing the lung syndrome， and also exhibits favorable economic benefits.

ObjectiveTo evaluate the clinical efficacy and economic value of the Jiangsu Traditional Chinese Medicine （TCM） Diagnosis and Treatment Protocol for Dominant Diseases （abbreviated as the Diagnosis and Treatment Protocol） in adult patients with non-severe community-acquired pneumonia （CAP） based on real-world clinical data. MethodsA retrospective real-world cohort study was conducted using electronic medical records of adult patients hospitalized for non-severe CAP from September 1st， 2023 to December 31st， 2024 across 10 TCM hospitals in Jiangsu province. Patients were classified into an exposure group and a non-exposure group based on whether they received Chinese herbal medicine （CHM） according to the Diagnosis and Treatment Protocol. The non-exposure group received only conventional western medicine， while the exposure group additionally received differentiated CHM for at least five consecutive days. Outcomes were compared between two patient groups， including cough resolution rate， sputum resolution rate （assessed by volume， color， and consistency）， incidence of abnormal C-reactive protein （CRP）， incidence of abnormal white blood cell （WBC） count， and radiographic resolution rate of pulmonary infiltrates on chest imaging. Multivariable logistic regression was performed to identify factors influencing clinical efficacy. Subgroup analyses were conducted according to age， gender， smoking status， history of hypertension， and pneumonia severity score （CURB-65）， and the efficacy of treatment for cough and sputum was analyzed within each subgroup. Cost-effectiveness analysis was conducted using cough resolution rate as the outcome measure， evaluating the pharmacoeconomics of the two groups. ResultsA total of 1688 patients were included with 1293 in the exposure group and 395 in the non-exposure group. Compared to the non-exposure group， the exposure group demonstrated significantly higher resolution rates of cough， sputum volume， color， and consistency， as well as a significantly lower incidence of abnormal CRP （P＜0.05）. No statistically significant difference was observed between the groups in terms of abnormal WBC count and radiographic resolution rate of pulmonary infiltrates （P＞0.05）. Logistic regression analysis showed that the cough resolution rate in the exposure group was 1.83 times that of the non-exposure group， while the probabilities of resolution in sputum volume， color， and consistency were 1.37， 2.09， and 1.56 times those of the non-exposure group， respectively （P＜0.05）. Subgroup analyses showed that the exposure group achieved significantly higher cough resolution rates across most subgroups except for populations with a CURB-65 score ≥2 or those with a history of hypertension （P＜0.05）. Specifically， among females， patients aged ≥18 and ＜65 years， non-smokers， those without hypertension， and those with a CURB-65 score of 0， the exposure group showed a higher cough resolution rate than the non-exposure group （P＜0.05）. From an economic perspective， total hospitalization cost， length of stay， antibiotic cost， and CHM cost all differed significantly between groups （P＜0.05）. The cost-effectiveness ratio （CER） was 10,788.80 CNY/case in the exposure group， while 22,513.80 CNY/case in the non-exposure group. This implies that， compared with the exposure group， the non-exposure group incurred an additional 17,302.27 CNY to achieve one case of cough resolution. When the willingness-to-pay threshold ranged from 0 to 50,000 CNY， the probability of economic advantage was consistently higher in the exposure group than in the non-exposure group. ConclusionOn the basis of conventional western medicine， the addition of CHM in accordance with the Diagnosis and Treatment Protocol can effectively improve clinical symptoms， reduce inflammatory markers， promote clinical recovery， and is more cost-effective in treating adults with non-severe CAP.

ObjectiveTo observe the real‑world effectiveness and economic outcomes of Weishi Qingjin Formula （苇石清金方， WQF） in the treatment of adult community‑acquired pneumonia （CAP） with phlegm‑heat obstructing the lung syndrome. MethodsBased on a multicenter， real-world retrospective cohort study， clinical data were collected from hospitalized adult patients diagnosed with non‑severe CAP and phlegm‑heat obstructing the lung syndrome in 10 traditional Chinese medicine （TCM） hospitals in Jiangsu province. Patients were divided into an exposure group （those who received oral WQF） and a non‑exposure group （those who did not）. The following outcomes were compared between the two groups before and after treatment， which were remission rates of clinical symptoms including cough， expectoration （sputum volume， color， consistency）， and chest pain， levels of inflammatory markers including C‑reactive protein （CRP） and white blood cell count （WBC）， and the rate of pulmonary inflammatory absorption on chest CT. Subgroup analyses were performed based on age， gender， smoking status， presence of hypertension， and the severity of community-acquired pneumonia （CURB‑65） score， comparing the two groups in terms of cough remission rate， chest pain remission rate， and chest CT absorption rate. For health economic evaluation， cost‑effectiveness analysis was used to calculate the cost‑effectiveness ratio （CER） and incremental cost‑effectiveness ratio （ICER）. Univariate sensitivity analysis and probabilistic sensitivity analysis were performed to test the robustness of the results. ResultsA total of 647 patients in the exposure group and 1491 patients in the non-exposure group were included in the final statistical analysis. There was no statistically significant difference in length of hospital stay， gender， marital status， smoking history， bronchoscopy history， and comorbidities between the groups （P＞0.05）， but age， CURB-65 score， and antibiotic use. The exposure group had significantly higher remission rates of cough and sputum consistency than the non-exposure group （P＜0.05）. After adjusting for confounders using propensity score matching and logistic regression， the cough remission rate in the exposure group was 1.49 times that of the non-exposure group （P＜0.01）. No significant difference was observed between groups in the reduction rates of CRP and WBC， and in the rate of pulmonary inflammatory absorption on chest CT （P＞0.05）. Subgroup analyses revealed that the cough remission rate in the exposure group was significantly better than that in the non-exposure group except for patients aged ≥65 years， smokers， hypertensive patients， those using other type antibiotics or not using antibiotics， and those with a CURB-65 score ≥1 （P＜0.05）. Among smokers， the chest pain remission rate in the exposure group was 4.38 times that of the non-exposure group （P＜0.01）. No significant difference in chest CT absorption rate was found between groups across subgroups of gender， age， hypertension status， or antibiotic type （P＞0.05）. In terms of economic evaluation， CER was 10,877.60 CNY/case in the exposure group and 16,773.10 CNY/case in the non-exposure group. Compared to the exposure group， the non-exposure group incurred an additional 15,034.26 CNY to achieve one case of cough resolution， indicating a more favorable cost-effectiveness profile. Probabilistic sensitivity analysis yielded results consistent with the cost-effectiveness analysis， confirming the robustness of the findings. ConclusionWQF demonstrates significant efficacy in improving cough symptoms in the treatment of adult CAP with phlegm-heat obstructing the lung syndrome， and also exhibits favorable economic benefits.

This paper systematically reviews the current status of integrated traditional Chinese and western medicine in the treatment of Helicobacter pylori （Hp） infection， as well as recent progress in clinical and basic research both in China and internationally. It summarizes the advantages of traditional Chinese medicine （TCM） in Hp infection management， including improving Hp eradication rates， enhancing antibiotic sensitivity， reducing antimicrobial resistance， decreasing drug-related adverse effects， and ameliorating gastric mucosal lesions. These advantages are particularly evident in patients who are intolerant to bismuth-containing regimens， those with refractory Hp infection， and individuals with precancerous gastric lesions. An integrated， whole-process management approach and individualized， staged comprehensive treatment strategies combining TCM and western medicine are proposed for Hp infection. Future prevention and control of Hp infection should adopt an integrative Chinese-western medical strategy， emphasizing prevention， strengthening primary care， implementing proactive long-term monitoring， optimizing screening strategies， and advancing the development of novel technologies and mechanistic studies of Chinese herbal interventions. These efforts aim to provide a theoretical basis and practical pathways for the establishment and improvement of Hp infection prevention and control systems.

Objective: To characterize perioperative dynamic changes in immune-cell phenotypes and inflammatory cytokines in patients undergoing CPB (cardiopulmonary bypass) cardiac surgery, and to explore their associations with postoperative outcomes. Methods: In this prospective cohort study, 120 adult patients who underwent elective cardiac surgery under CPB at West China Hospital from May 2022 to March 2023 were enrolled. Perioperative immune-cell phenotypes and concentrations of 40 inflammation-related cytokines were measured. The primary outcomes were the sequential organ failure assessment (SOFA) score at 24 h after surgery and ΔSOFA (the peak SOFA score within 48 h after surgery minus the preoperative SOFA score). Secondary outcomes included major adverse cardiovascular events (MACE), acute kidney injury (AKI), respiratory failure, severe liver injury, and infection. Results: The mean age of enrolled patients was 57±10 years. Of these, 52% (62/120) were male and 90% (108/120) underwent valve surgery. During the rewarming to the end of CPB, neutrophil counts rapidly increased (7.39×10 /L vs preoperative 3.07×10 /L, P<0.001), with significant upregulation of CD11b (7.30×10 /L vs preoperative 3.05×10 /L, P<0.001) and CD54 (7.15×10 /L vs preoperative 2.99×10 /L, P<0.001). Lymphocyte counts increased at the end of CPB (1.75×10 /L vs preoperative 1.12×10 /L, P<0.001) but decreased significantly at 24 h after surgery (0.59×10 /L vs preoperative 1.12×10 /L, P<0.001). Plasma analysis showed that multiple pro-inflammatory cytokines increased during CPB and remained elevated up to 24 h after surgery; five chemokines and the anti-inflammatory cytokine IL-10 peaked at the end of CPB. The SOFA score increased from 1 (1, 2) preoperatively to 7 (5, 10) at 24 h after surgery, with a ΔSOFA of 6 (4, 8). Within 30 days after surgery, 48 patients (40.0%) developed AKI, 17 (14.2%) developed infection, 4 (3.3%) developed severe liver injury, 3 (2.5%) developed respiratory failure, and 3 (2.5%) experienced MACE. During the 2-year follow-up, 8 patients (6.7%) experienced MACE and 5 (4.2%) died. Conclusion: Multi-organ dysfunction is common after cardiac surgery under CPB (median ΔSOFA, 6), accompanied by perioperative activation of multiple immune-cell subsets and upregulation of pro-inflammatory, anti-inflammatory, and chemotactic mediators. This study provides data-driven evidence and research clues for further investigation of the associations between CPB-related immune perturbations and postoperative organ dysfunction and clinical outcomes.

Introduction: Adequate knowledge of diabetes is essential for effective self-management and glycemic control. Emerging trends in digital platforms, video-based education offer a scalable and accessible approach to patient learning. However, evidence on the effectiveness of validated YouTube-based diabetes education in the Malaysian population remains limited. We aimed to evaluate the impact of a newly developed, tri-language YouTube diabetes education programme on clinical and knowledge outcomes. Methodology: In this multicentre study, patients with diabetes mellitus were randomly assigned to intervention (YouTube-based education) and control groups (standard care). The intervention consisted of newly developed and validated short educational videos on YouTube regarding diabetes, complications and lifestyle changes, delivered weekly via WhatsApp over 9 weeks. Videos were available in English, Malay and Chinese. The control group received standard care and counseling. Demographic data, hemoglobin A1c (HbA1c), and knowledge scores were collected at baseline and 3 months post-intervention. Results: A total of 109 patients (62.4% female; mean age 53.2 years; mean diabetes duration 16.3 years) were enrolled in the study, with similar baseline characteristics between groups. The intervention group demonstrated significantly greater improvement in glycemic control compared to the control group (HbA1c: −1.22 ± 1.36% vs. −0.24 ± 1.05%; p <0.001). While knowledge scores improved in both groups, the increase was significantly greater in the intervention group (2.66 vs. 0.80; p = 0.001). Notably, improvement in knowledge score predicted HbA1c reduction (b = 0.091; 95% CI 0.01, 0.172; p = 0.028). Conclusion The tri-language YouTube-based diabetes education programme significantly improved both glycemic control and patients’ knowledge. This accessible, scalable video-based education represents an effective strategy to enhance diabetes selfmanagement, offering flexible, on-demand learning for diverse populations.
Social Media ; Diabetes Mellitus

Objective The aim of the study is to analyze the incidence patterns and epidemiological characteristics of parasitic and vector-borne diseases in the Minhang and Jinshan districts of Shanghai, and provide evidence-based information for optimizing prevention and control measures. Methods We collected information from epidemic reports and epidemiological investigation forms for cases of parasitic and vector-borne diseases from 2005 to 2024 in Shanghai's Minhang and Jinshan districts. Descriptive epidemiological method were adopted to conduct a comparative analysis of incidence trends, epidemic characteristics, and infection sources. Results A total of 229 cases in 7 categories were reported between 2005 and 2024, with an average annual incidence rate of 0.36/100 000. The average annual incidence rate in Minhang District was significantly higher than that in Jinshan District. The most prevalent diseases were malaria and dengue fever, followed by Japanese encephalitis. Monthly case reports were available, predominantly from June to October, with a peak in July-August. A statistically significant difference was observed between the two districts in case distribution during June-October (P＜0.001), whereas no significant difference was found for July-August (P=0.331). The majority of cases were young men (111/229,48.47%), aged 20-39 years. Migrant workers/farmers constituted the largest occupational group (55/229, 24.02%). Registered residents of other provinces and cities (147/229,64.19%), and the main source of infection was overseas importation (112/229,48.91%). There were no statistically significant differences in gender and household-registration composition between the two districts (P＞0.05). Significant differences existed in age, occupation, and source of infection (P＜0.05). The imported diseases were malaria and dengue fever, with Africa and Southeast Asia being the primary source locations. Malaria was the predominant disease imported from other provinces and cities, with cases having been imported from abroad since 2012. Local infections were mainly Japanese encephalitis, followed by malaria (with the last local case reported in 2010). Cases between 2005 and 2009 were predominantly imported from other provinces and cities. The proportion of cases imported from abroad increased sharply after 2010, particularly in Minhang District. Local infections sometimes arise in Jinshan District, with Japanese encephalitis serving as the primary type. Conclusions Incidence rates of parasitic and vector-borne diseases in Minhang and Jinshan districts have generally remained low. To further reduce this disease burden, it will be necessary to strengthen joint measures for prevention and control, eliminate the environmental risk factors of vector organisms, enhance monitoring and precise control of the environment and inbound personnel to prevent the occurrence and transmission of parasitic and vector-borne diseases.

With the rapid development of generative artificial intelligence(GAI)technologies,their widespread application in academic research and writing is continuously expanding the boundaries of sci-entific inquiry.However,this trend has also raised a series of ethical and regulatory challenges,inclu-ding issues related to authorship,content authenticity,citation accuracy,and accountability.In light of the growing involvement of AI in generating academic content,establishing an open,controllable,and trustworthy ethical governance framework has become a key task for safeguarding research integrity and maintaining trust within the academic community.This expert consensus outlines ethical requirements across key stages of AI-assisted academic writing-including topic selection,data management,citation practices,and authorship attribution.It aims to clarify the boundaries and ethical obligations surrounding AI use in academic writing,ensuring that technological tools enhance efficiency without compromising in-tegrity.The goal is to provide guidance and institutional support for building a responsible and sustainable research ecosystem.

Objective:To establish and evaluate a second-tier screening method for neonatal congenital adrenal hyperplasia (CAH) and develop appropriate screening interpretation criteria.Methods:We employed liquid chromatography-tandem mass spectrometry to simultaneously detect five steroid hormones in dried blood spots: 17α-hydroxyprogesterone (17α-OHP), androstenedione (A4), 11-deoxycortisol (11-DOC), 21-deoxycortisol (21-DOC), and cortisol (F), calculating (17α-OHP+A4)/F and (17α-OHP+21-DOC)/F ratios for second-tier CAH screening. The study utilized 429 residual dried blood spot samples from neonates (0-7 days) who completed first-tier screening between January 2020 and March 2024 in Guangzhou Women and Children's Medical Center, Guangzhou Medical University, including first-tier negatives ( n=369), confirmed false positives ( n=50), and CYP21A2-confirmed 21-hydroxylase deficiency patients ( n=10). Mann-Whitney U and Kruskal-Wallis tests analyzed steroid concentration variations across gestational ages and birth weights in all negative samples, with reference intervals established via P2.5- P97.5 percentiles and screening cutoffs set at population P97.5. Receiver operating characteristic (ROC) curve analysis identified optimal interpretation indicators among steroid hormone profiles, with second-tier screening performance evaluated by comparing sensitivity and specificity across different steroid hormone indicators to establish the optimal diagnostic criteria. Results:The five steroid hormones demonstrated intra-assay precision with coefficient of variation (CV) of 9.8%-14.2% and inter-assay precision with CV of 4.7%-14.4% across three different concentration levels of quality control materials. Accuracy ranged from 98.5% to 110.0% and the lower limits of quantification were 0.25 ng/ml for 17α-OHP, 0.05 ng/ml for A4/11-DOC, 0.31 ng/ml for 21-DOC, and 0.1 ng/ml for F. Stratification by gestational age categorized 17α-OHP into ≤31, 32-34, and ≥35 weeks; A4 into ≤31, 32-36, and ≥37 weeks; and 11-DOC into ≤31 and ≥32 weeks, while the remaining indicators were not stratified. When grouped by birth weight (low/normal), all measured parameters except 21-DOC showed statistically significant differences between groups (all P<0.05). Established reference intervals included 17α-OHP: 0.53-7.82 ng/ml (≤31 weeks), <0.25-3.60 ng/ml (32-34 weeks), <0.25-1.64 ng/ml (≥35 weeks); A4: 0.12-2.36 ng/ml (≤31 weeks), <0.05-1.45 ng/ml (32-36 weeks), 0.17-0.95 ng/ml (≥37 weeks); 11-DOC: 0.43-4.04 ng/ml (≤31 weeks), 0.08-1.46 ng/ml (≥32 weeks); F: 1.70-83.70 ng/ml; 21-DOC: <0.31-0.69 ng/ml; (17α-OHP+A4)/F: 0.01-0.74; and (17α-OHP+21-DOC)/F: 0.01-0.69. Comprehensive comparison of CAH second-tier screening performance demonstrated that interpretation based on elevated 17α-OHP accompanied by either elevated 21-DOC or elevated ratios [(17α-OHP+A4)/F or (17α-OHP+21-DOC)/F] achieved 100% sensitivity, 96% specificity, and a 96% reduction in false-positive rate. Conclusion:The application of liquid chromatography-tandem mass spectrometry for multi-steroid hormone profiling in second-tier neonatal CAH screening, utilizing gestational age-specific 17α-OHP cutoffs combined with elevated 21-DOC or ratio criteria, demonstrated 100% screening sensitivity while substantially reducing false-positive rates from primary screening, though further validation with expanded sample sizes remains necessary.