Tree diversity increases decadal forest soil carbon and nitrogen accrual.

Increasing soil carbon and nitrogen storage can help mitigate climate change and sustain soil fertility1,2. A large number of biodiversity-manipulation experiments collectively suggest that high plant diversity increases soil carbon and nitrogen stocks3,4. It remains debated, however, whether such conclusions hold in natural ecosystems5-12. Here we analyse Canada's National Forest Inventory (NFI) database with the help of structural equation modelling (SEM) to explore the relationship between tree diversity and soil carbon and nitrogen accumulation in natural forests. We find that greater tree diversity is associated with higher soil carbon and nitrogen accumulation, validating inferences from biodiversity-manipulation experiments. Specifically, on a decadal scale, increasing species evenness from its minimum to maximum value increases soil carbon and nitrogen in the organic horizon by 30% and 42%, whereas increasing functional diversity enhances soil carbon and nitrogen in the mineral horizon by 32% and 50%, respectively. Our results highlight that conserving and promoting functionally diverse forests could promote soil carbon and nitrogen storage, enhancing both carbon sink capacity and soil nitrogen fertility.

Native diversity buffers against severity of non-native tree invasions.

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4. Here, leveraging global tree databases5-7, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions.

Linking fine root lifespan to root chemical and morphological traits-A global analysis.

Fine root lifespan is a critical trait associated with contrasting root strategies of resource acquisition and protection. Yet, its position within the multidimensional "root economics space" synthesizing global root economics strategies is largely uncertain, and it is rarely represented in frameworks integrating plant trait variations. Here, we compiled the most comprehensive dataset of absorptive median root lifespan (MRL) data including 98 observations from 79 woody species using (mini-)rhizotrons across 40 sites and linked MRL to other plant traits to address questions of the regulators of MRL at large spatial scales. We demonstrate that MRL not only decreases with plant investment in root nitrogen (associated with more metabolically active tissues) but also increases with construction of larger diameter roots which is often associated with greater plant reliance on mycorrhizal symbionts. Although theories linking organ structure and function suggest that root traits should play a role in modulating MRL, we found no correlation between root traits associated with structural defense (root tissue density and specific root length) and MRL. Moreover, fine root and leaf lifespan were globally unrelated, except among evergreen species, suggesting contrasting evolutionary selection between leaves and roots facing contrasting environmental influences above vs. belowground. At large geographic scales, MRL was typically longer at sites with lower mean annual temperature and higher mean annual precipitation. Overall, this synthesis uncovered several key ecophysiological covariates and environmental drivers of MRL, highlighting broad avenues for accurate parametrization of global biogeochemical models and the understanding of ecosystem response to global climate change.

Higher tree diversity is linked to higher tree mortality.

Examining the relationship between tree diversity and ecosystem functioning has been a recent focus of forest ecology. Particular emphasis has been given to the impact of tree diversity on productivity and to its potential to mitigate negative global change effects; however, little attention has been paid to tree mortality. This is critical because both tree mortality and productivity underpin forest ecosystem dynamics and therefore forest carbon sequestration. Neglecting tree mortality leaves a large part of the picture undocumented. Here we show that increasingly diverse forest stands have increasingly high mortality probabilities. We found that the most species-rich stands in temperate biomes had mortality probabilities more than sevenfold higher than monospecific stands (∼0.6% year−1 in monospecific stands to 4.0% year−1 in the most species-rich stands) while in boreal stands increases were less pronounced but still significant (∼1.1% year−1 in monospecific stands to 1.8% year−1 in the most species-rich stands). Tree species richness was the third-most-important predictor of mortality in our models in temperate forests and the fifth-most-important predictor in boreal forests. Our results highlight that while the promotion of tree diversity undoubtedly has many positive effects on ecosystem functioning and the services that trees provide to humanity, it remains important to consider all aspects of forest dynamics in order to properly predict the implications of maintaining and promoting tree diversity.

The number of tree species on Earth.

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness.

Search for a Sub-eV Sterile Neutrino Using Daya Bay's Full Dataset.

This Letter presents results of a search for the mixing of a sub-eV sterile neutrino with three active neutrinos based on the full data sample of the Daya Bay Reactor Neutrino Experiment, collected during 3158 days of detector operation, which contains 5.55×10^{6} reactor ν[over ¯]_{e} candidates identified as inverse beta-decay interactions followed by neutron capture on gadolinium. The analysis benefits from a doubling of the statistics of our previous result and from improvements of several important systematic uncertainties. No significant oscillation due to mixing of a sub-eV sterile neutrino with active neutrinos was found. Exclusion limits are set by both Feldman-Cousins and CLs methods. Light sterile neutrino mixing with sin^{2}2θ_{14}≳0.01 can be excluded at 95% confidence level in the region of 0.01 eV^{2}≲|Δm_{41}^{2}|≲0.1 eV^{2}. This result represents the world-leading constraints in the region of 2×10^{-4} eV^{2}≲|Δm_{41}^{2}|≲0.2 eV^{2}.

A novel perspective for exploring the relationship between cerebral small vessel disease and deep medullary veins with automatic segmentation.

BACKGROUND: This study aimed to establish an intelligent segmentation algorithm to count the number of deep medullary veins (DMVs) and analyze the relationship between DMVs and imaging markers of cerebral small vessel disease (CSVD). METHODS: DMVs on magnetic resonance imaging (MRI) of patients with CSVD were counted by intelligent segmentation and manual counting. The dice coefficient and intraclass correlation coefficient (ICC) were used to evaluate their consistency and correlation. Structural MR images were used to assess imaging markers and total burden of CSVD. A multivariate linear regression model was used to evaluate the correlation between the number of DMVs counted by intelligent segmentation and imaging markers of CSVD, including white matter hyperintensities of the presumed vascular origin, lacune, perivascular spaces, cerebral microbleeds, and total CSVD burden. RESULTS: A total of 305 patients with CSVD were enrolled. An intelligent segmentation algorithm was established to calculate the number of DMVs, and it was validated and tested. The number of DMVs counted intelligently significantly correlated with the manual counting method (r = 0.761, P< 0.001). The number of smart-counted DMVs negatively correlated with the imaging markers and total burden of CSVD (P< 0.001), and the correlation remained after adjusting for age and hypertension (P< 0.05). CONCLUSIONS: The proposed intelligent segmentation algorithm, which was established to count DMVs, can provide objective and quantitative imaging information for the follow-up of patients with CSVD. DMVs are involved in CSVD pathogenesis and a likely new imaging marker for CSVD.

Multiphase computed tomography angiography combined with inflammation index to predict clinical functional prognosis in patients with acute ischemic stroke.

AIM: In this study, we investigated the feasibility of the Alberta Stroke Program Early CT Score (ASPECTS) and multiphase computed tomography angiography (mCTA) lateral branch circulation grading combined with clinical and laboratory indicators to predict the clinical prognosis of patients with acute ischemic stroke after 90 days. MATERIALS AND METHODS: The clinical data of 80 patients with acute anterior circulation ischemic stroke were retrospectively analyzed and divided into the good prognosis (37 cases) and poor prognosis groups (43 cases) according to their clinical function score at 90 days after discharge. Various factors, including basic imaging parameters (ASPECTS), occluded vessel location, affected side location and clinical indicators (time from onset to computed tomography examination, height, weight, body mass index, previous hypertension, and degree of hypertension and diabetes mellitus), laboratory blood rutine, and biochemical tests (white blood count, neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio, hematocrit test, platelet count, international normalized ratio, blood glucose, triglycerides, uric acid, and D-dimer) were considered in the analysis. RESULTS: Logistic regression analysis showed that the mCTA score, hypertension, and neutrophil count were significant independent predictors. CONCLUSION: A nomogram of the mCTA score, hypertension, and neutrophil count may predict functional recovery after 90 days in patients with acute ischemic stroke.

Interaction between nutrition-related parameters and sexual orientation on depression.

OBJECTIVES: Sexual minorities may be more vulnerable to mental disorders. Previous studies have found associations between diet and depression, but no studies have focused on the interaction between nutrition-related parameters and sexual orientation regarding depression. This study aims to explore the interaction between nutrition-related parameters and sexual orientation regarding depression. STUDY DESIGN: Cross-sectional analysis using NHANES 2007-2016 data. METHODS: This study utilized data from NHANES 2007-2016, with 11,065 participants involved. Nutrition-related parameters were evaluated using the healthy eating index-2015 (HEI-2015) and the dietary inflammation index (DII), while depression was obtained through Patient Health Questionnaire (PHQ-9). Logistic regression and stratified analysis of subgroups were used in this study. RESULTS: Compared to those who consumed healthy and anti-inflammatory diets, the ORs for depression in groups consuming unhealthy and pro-inflammatory diets were 1.366 (95%CI:1.073,1.738) and 1.652 (95%CI:1.345,2.028), respectively. Sexual minorities have a higher risk of depression than heterosexuals. There is an interaction effect (P = 0.037) between HEI-2015 and sexual orientation on depression, while it was not found in DII. Subgroup analysis indicated that the interaction between sexual orientation and HEI-2015 persisted in males (P = 0.024), but not in females. CONCLUSION: Both diet and sexual orientation had impacts on depression. There was an interaction between HEI-2015 and sexual orientation on depression, and this association was different by gender. Sexual minorities who are Gay/lesbian, Bisexual, and Something else are at higher risk for depression, and adopting healthy eating patterns and anti-inflammatory diets that are consistent with the recommendations of the USDA may appropriately reduce the risk of depression.

Surgical treatment of nasopharyngeal cancer - a consensus recommendation from two Chinese associations.

BACKGROUND: Surgical treatment is playing an increasingly important role in the management of nasopharyngeal carcinoma (NPC). This consensus focuses on the indications for optimal surgery, and surgical methods in the whole process of treatment for NPC to provide a useful reference to assist these difficult clinical decisions. METHODOLOGY: A thorough review of available literature on NPC and surgery was conducted by the Association for the prevention and treatment of nasopharyngeal carcinoma in China, international exchange and promotion Association for medicine and healthcare, and the Committee on nasopharyngeal cancer of Guangdong provincial anticancer association. A set of questions and a preliminary draft guideline was circulated to a panel of 1096 experienced specialists on this disease for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the experts in two authoritative medical science and technology academic groups in the prevention and treatment of NPC in China for review and reconsideration. RESULTS: The initial round of questions showed variations in clinical practice even among similar specialists, reflecting the lack of high-quality supporting data and resulting difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of surgery, including indications and surgical approaches. CONCLUSION: By standardizing the surgical indications and practice, we hope not only to improve the surgical outcomes, but also to highlight the key directions of future clinical research in the surgical management of NPC.

[Enhance the management of perioperative crisis events, improve the safety and quality of pediatric anesthesia].

Perioperative crisis events refer to unexpected seriously life-threatening when the patient is during or after surgery, and require rapid identification, evaluation, and management by clinical teams to minimize harm. The pediatric anesthesia management during perioperative period is special and challenging for anesthesiologists, requiring professional technical and non-technical skills. The article mainly elaborates on the incidence and risk factors of pediatric anesthesia crisis events during perioperative period and introduces the concept of anesthesia crisis resource management and strategies. The anesthesiologist team needs to adopt a crisis resource management strategy, taking a typical crisis event of malignant hyperthermia as an example, including identification of crisis signs immediately, termination of trigger drugs rapidly, intravenous injection of the special drug dantrolene, physical cooling, and symptomatic support treatment, seeking assistance from other teams actively, recording and feeding back. This study aims to improve the cognitive decision-making ability and teamwork ability of anesthesiologists and their teams, effectively preventing and responding to potential crisis events effectively, and ensuring the safety of pediatric patients during perioperative period.

[Establishment and validation of prediction models for human leukocyte antigen haplotypes and human leukocyte antigen genotypes].

Objective: To establish prediction models for human leukocyte antigen (HLA) haplotypes and HLA genotypes, and verify the prediction accuracy. Methods: The prediction models were established based on the characteristic of HLA haplotype inheritance and linkage disequilibrium (LD), as well as the invention patents and software copyrights obtained. The models include algorithm and reference databases such as HLA A-C-B-DRB1-DQB1 high-resolution haplotypes database, B-C and DRB1-DQB1 LD database, G group alleles table, and NMDP Code alleles table. The prediction algorithm involves data processing, comparison with reference data, filtering results, probability calculation and ranking, confidence degree estimation, and output of prediction results. The accuracy of the predictions was verified by comparing them with the correct results, and the relationship between prediction accuracy and the probability distribution and confidence degree of the predicted results was analyzed. Results: The HLA haplotypes and genotypes prediction models were established. The prediction algorithm included the prediction of A-C-B-DRB1-DQB1 haplotypes according to HLA-A, B, DRB1, C, DQB1 genotypes, the prediction of C and DQB1 high-resolution results according to A, B and DRB1 high-resolution results, and the prediction of A, B, DRB1, C and DQB1 high resolution results according to the A, B and DRB1 intermediate or low resolution results. Validation results of "Predicting A-C-B-DRB1-DQB1 haplotypes basing on HLA-A, B, DRB1, C, DQB1 genotypes" model: for 787 data, the accuracy was 94.0% (740/787) with 740 correct predictions, 34 incorrect predictions, and 13 instances with no predicted results. For 847 data, the accuracy was 100% (847/847). The 2 411 and 2 594 haplotype combinations predicted from 787 and 847 data were grouped according to confidence degree, the accuracy was 100% (48/48, 114/114) for a confidence degree of 1, 96.2% (303/315) and 97.8% (409/418) for a confidence degree of 2 respectively. Validation results of "Predicting A, B, DRB1 and C, DQB1 high-resolution genotypes basing on HLA-A, B, DRB1 high, intermediate, or low resolution genotypes" model: when predicting C and DQB1 high resolution genotypes basing on A, B, and DRB1 high resolution genotypes, 89.3% (1 459/1 634) of the predictions were correct. The accuracy for the top 2 predicted probability (GPP) ranking was 79.2% (1 156/1 459), and for the top 10, it was 95.0% (1 386/1 459). Furthermore, when GPP≥90% and GPP 50%-90%, the prediction accuracy was 81.3% (209/257) and 72.8% (447/614) respectively. The accuracy of predicting C and DQB1 high resolution genotypes basing on the results of A, B, and DRB1 high resolution genotypes from the China Marrow Donor Program was 87.0% (20/23). The accuracy of predicting A, B, DRB1, C, and DQB1 high resolution genotypes basing on the results of A, B, and DRB1 intermediate or low-resolution genotypes was 70.0% (7/10) and 52.5% (21/40) respectively. When predicting whether the patient is likely to have a HLA 10/10 matched donor, the accuracy of the top 2 GPP combinations with a proportion of ≥50% was 85.7% (6/7). Conclusions: When using A, B, DRB1, C, DQB1 genotypes to predict A-C-B-DRB1-DQB1 haplotype combinations, the results with a confidence degree of 1 and 2 are reliable. When predicting C and DQB1 genotypes according to A, B and DRB1 genotypes, the top 10 results ranked by GPP are reliable, and the top 2 results with GPP≥50% are more reliable.

[Preliminary exploration of the clinical warning value of ischemic modified albumin in the development of pre-eclampsia].

Objective: To explore the clinical warning value of ischemic modified albumin (IMA) and IMA to human serum albumin (HSA) ratio (IMAR) in the development of pre-eclampsia (PE) and its severity. Methods: A total of 156 pregnant women with PE admitted to the Haidian District Maternal and Child Health Hospital of Beijing from April 2022 to March 2023 were collected as the PE group, and 156 healthy pregnant women with the same age and gestational age were matched as the control group. PE pregnant women were further divided into severe PE group (78 cases) and non-severe PE group (78 cases). Severe PE pregnant women were divided into emergency group (42 cases) and non-emergency group (36 cases) according to the disease progression time.All pregnant women were stratified according to their HSA levels (<30 g/L, 30-32 g/L, ≥32 g/L), and the peripheral blood IMA, HSA, and IMAR of pregnant women in different periods and subgroups were compared, and also the difference of IMA levels in umbilical artery blood. Bivariate correlation analysis was used to explore the correlation between severe PE and IMA or IMAR, and receiver operating characteristic (ROC) curves was used to analyze the diagnostic value of IMA, HSA, and IMAR for PE and severe PE. Results: (1) The IMA level and IMAR in peripheral serum of pregnant women in the PE group at diagnosis, and the IMA level in umbilical artery blood at delivery, and peripheral serum at 2 days after delivery were higher than those in the control group. The HSA level in peripheral serum was lower than that in the control group at diagnosis, and the differences were statistically significant (all P<0.001). (2) The IMA level and IMAR in the peripheral serum of pregnant women with severe PE were higher than those in the non-severe PE group at diagnosis, while the HSA level were lower than those in the non-severe PE group. The differences were statistically significant (all P<0.05). At diagnosis, the IMA level and IMAR in peripheral serum of pregnant women in the emergency group were higher than those in the non-emergency group, while the HSA level was lower than that in the non-emergency group. The differences were statistically significant (all P<0.05). When diagnosed, the peripheral serum IMA levels of pregnant women in the PE group were compared between subgroups with HSA<30 g/L, 30-32 g/L, ≥32 g/L, and there was no statistically significant difference (F=0.366, P=0.694). However, the IMAR was compared between the three subgroups, and the difference was statistically significant (F=28.544, P<0.001), which increased with the decrease of HSA levels. In the subgroup with HSA≥32 g/L, the peripheral serum IMA level and IMAR of pregnant women in the PE group were higher than those in the control group at diagnosis, and the differences were statistically significant (all P<0.001). (3) The severe PE manifestations positively correlated with peripheral serum IMAR at diagnosis include systolic blood pressure (r=0.279), mean arterial pressure (r=0.212), and urinary protein quantification (r=0.277), while the severe PE manifestations negatively correlated include HSA levels (r=-0.644) and newborn birth weight (r=-0.305), all of which were significantly correlated (P<0.05). (4) The area under curve (AUC) for IMAR diagnosis of PE was 0.875 (95%CI: 0.833-0.916), with the highest diagnostic efficiency at a cutoff value of 2.06, sensitivity of 72.5%, and specificity of 85.1%. The AUC for diagnosing severe PE was 0.871 (95%CI: 0.822-0.919), with the highest diagnostic efficacy at a cutoff value of 2.18, sensitivity of 72.3%, and specificity of 88.3%. The diagnostic efficacy of IMAR for PE and severe PE were higher than those of IMA and HSA levels. Conclusions: The level of IMA and IMAR in pregnant women with PE are higher than those in normal pregnant women. IMA and IMAR are correlated with the severity of PE, with IMAR changes occurring earlier and more significantly. IMAR could be considered as one of the evaluation indicators for the development of PE, or as a more sensitive PE severity warning indicator than HSA.

[Common issues and solutions in intraoperative frozen pathological diagnosis of small pulmonary nodules].

With the development of chest CT screening, surgically resected lung tumors have shifted from predominantly large masses to predominantly small nodules. The intraoperative frozen diagnosis of pulmonary small nodules faces many challenges, such as the accurate understanding about the concepts of adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic adenocarcinoma, as well as their differential diagnosis with small size invasive adenocarcinoma, benign tumors (such as bronchiolar adenoma, sclerosing pneumocytoma, etc.), metastatic tumors and so on. This study summarizes some common problems encountered in the intraoperative frozen diagnosis of small pulmonary nodules in daily practice, focusing on the diagnosis and differential diagnosis of adenocarcinoma, in order to make the accurate intraoperative frozen diagnosis of small pulmonary nodules and diminish misdiagnosis.

[Serum hepatitis B virus pregenomic RNA profiles in patients with chronic hepatitis B on long-term antiviral therapy].

Objective: To explore the clinical changes in levels of the new clinical marker serum hepatitis B virus (HBV) pregenomic RNA (pgRNA) in patients with chronic hepatitis B (CHB) with long-term antiviral therapy. Methods: 100 CHB cases who were initially treated with nucleos(t)ide analogues (NAs) at Peking University First Hospital were included. The levels of alanine aminotransferase (ALT), HBV DNA, hepatitis B e-antigen (HBeAg), and hepatitis B surface antigen (HBsAg) during the follow-up period were measured. The TaqMan-based real-time quantitative PCR method was used to detect serum HBV pgRNA levels. The independent sample t-test and Mann-Whitney U test were used to compare continuous variables between groups, while Pearson's χ (2) test and Fisher's exact test were used to compare categorical variables. Results: HBV pgRNA levels decreased significantly in patients who developed virological responses at 48 weeks (n = 54) during subsequent treatment compared to those who did not (n = 46). The HBV pgRNA level was lower in HBeAg-positive patients than in HBeAg-negative patients (P < 0.05 or P < 0.01). Patients with higher HBV DNA and HBeAg-positivity levels at baseline had a higher HBV pgRNA level following antiviral therapy. There was no statistically significant difference in HBV pgRNA levels in patients with different HBV pgRNA levels at baseline after antiviral therapy. There was no correlation between serum HBV pgRNA and HBsAg at baseline, but there was a correlation after long-term antiviral therapy, while there was a weak correlation between HBV pgRNA and HBsAg at the fifth and ninth years of antiviral therapy (r = 0.262, P = 0.031; r = 0.288, P = 0.008). Conclusion: HBV pgRNA levels were higher with higher HBV activity in CHB patients with long-term antiviral therapy.

[The ninth edition of TNM staging for lung cancer: precise staging for precise diagnosis and treatment].

The ninth edition of TNM staging for lung cancer has been announced at the 2023 World Lung Cancer Congress and implemented from January 1, 2024. The focus of the ninth TNM staging change is dividing N2 into N2a and N2b, as well as M1c into M1c1 and M1c2. Although the T staging has not changed, it has played an important role in verifying the eighth edition of the T staging. The subdivision of stage N2 has led some patients with ⅢA of the eighth edition to experience ascending or descending stages, which will more accurately help to assess the condition and prognosis of patients with mediastinal lymph node metastasis, as well as the design of related clinical studies. Modifying the M1c staging will help define oligometastasis and explore new treatment models in the future. The ninth edition of the TNM staging system provides a more detailed division of different tumor loads, but there is no clear explanation for the staging of lung cancer after neoadjuvant therapy. Further data analysis is needed, and it is expected to be answered in the tenth edition of TNM staging.

[Relationship between cardiopulmonary exercise testing and the prognosis of cardiovascular disease in coronary heart disease patients].

Objective: To investigate the predictive value of cardiopulmonary exercise test (CPET) indexes for major adverse cardiovascular events (MACE) in patients with coronary heart disease (CHD). Methods: This study was a retrospective cohort study. CHD patients were consecutively enrolled who procedure CPET before discharge from the Department of Cardiology, General Hospital of Northern Theater Command from November 2015 to September 2021 were enrolled. Demographic information, past medical history, CPET indexes and other baseline data were collected and the patients were followed up. Patients were divided into a MACE group and a control group according to the presence or absence of MACE. A multivariate Cox proportional hazard regression model was used to analyze the CPET indexes with predictive value for MACE in CHD patients. Results: A total of 3 800 patients were eligible for the criterion, age (57.2±8.8) years, 2 920 (76.84%) males. During a follow-up of 1 237 (695, 1 596) days, 390 (10.26%) patients were in MACE group, and 3 410 (89.74%) patients were in control group. In adjusted multivariable analysis, higher metabolic equivalent of tasks (MET) at anaerobic threshold (AT) is an independent protective factor for MACE in patients with CHD (HR=0.75, 95%CI 0.62-0.90, P=0.002), higher VE/VCO2 is an independent risk factor for MACE in CHD patients (HR=1.05, 95%CI 1.02-1.07, P=0.001). Conclusion: In CPET, high MET at AT is an independent protective factor for MACE in patients with CHD, and high VE/VCO2 is an independent risk factor for MACE in CHD patients.

[Exploring the characteristics changes of cardiopulmonary exercise testing in patients with acute coronary syndrome after PCI before and during the COVID-19 pandemic].

Objective: To investigate the changes in cardiopulmonary exercise testing (CPET) characteristics before and after the outbreak of COVID-19 in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI). Methods: This is a cross-sectional study that included ACS patients who underwent PCI at the General Hospital of the Northern Theater Command from July 2018 to February 2023. Based on the timeline of the COVID-19 pandemic, patients were divided into two groups: the pre-pandemic group and the during-pandemic group, with January 2020 as the dividing line. Clinical data were collected from both groups, and a comparative analysis was performed on their postoperative CPET outcomes, including peak oxygen uptake (peak VO2), peak metabolic equivalents (peak MET), and other indicators. Weber's classification was used to assess cardiac function. In addition, the 7-tiem generalized anxiety disorder scale (GAD-7) and the patient health questionnaire-9 (PHQ-9) were used to assess the patients' psychological anxiety and depression states, respectively. Multivariate logistic regression was used to analyze the influencing factors of CPET after PCI. Results: A total of 4 310 post-PCI ACS patients were included, with an average age of (58.7±9.1) years, and 3 464 (80.37%) were male. There were 1 698 patients in the pre-pandemic group and 2 612 patients in the during-pandemic group. The main indicator of the CPET, peak VO2 (15.04±3.93) ml·min-1·kg-1 in the during-pandemic group, was lower than that in the pre-pandemic group (15.52±3.68) ml·min-1·kg-1, and the difference was statistically significant (P<0.001). Multivariate logistic regression analysis showed that advanced age, female gender, high body mass index, elevated high-sensitivity C-reactive protein, reduced high-density lipoprotein cholesterol, smoking history, history of myocardial infarction, more severe ACS classification, and mild to moderate degree of depression were related to poor cardiopulmonary outcomes (P<0.05). Conclusion: The COVID-19 pandemic had a negative impact on the cardiopulmonary outcomes of ACS patients after PCI. Reduced physical activity, and increased psychological stress should be given consideration and attention regarding their impact on patients' cardiopulmonary function.