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Precious metal nanoparticles have been widely investigated due to their excellent activity shown in catalysis and sensing. However, how to prepare highly dispersed noble metal nanoparticles to improve the lifetime of catalysts and reduce the cost is still an urgent problem to be solved. In this study, a carbon-based carrier material was prepared by an expansion method and loaded with Pd or Ag nanoparticles on this carbon material to synthesize precious metal nanoparticle composites, which were characterized in detail. The results show that the nanoparticles prepared using this method exhibit superior dispersion. Under the synergistic effect of noble metal nanoparticles and porous carbon carriers, the composites exhibited excellent catalytic degradation of p-nitrophenol and showed excellent sensing performance in the modified hydrogen peroxide sensor electrode. This approach is highly informative for the preparation of nanocomposites in medical and environmental fields.
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Acute ischemic stroke (AIS) is the most prevalent type of stroke, and due to its high incidence, disability rate, and mortality rate, it imposes a significant burden on the health care system. Amino acids constitute one of the most crucial metabolic products within the human body, and alterations in their metabolic pathways have been identified in the microenvironment of AIS, thereby influencing the pathogenesis, severity, and prognosis of AIS. The amino acid metabolism characteristics in AIS are complex. On one hand, the dynamic progression of AIS continuously reshapes the amino acid metabolism pattern. Conversely, changes in the amino acid metabolism pattern also exert a double-edged effect on AIS. This interaction is bidirectional, dynamic, heterogeneous, and dose-specific. Therefore, the distinctive metabolic reprogramming features surrounding amino acids during the AIS process are systematically summarized in this paper, aiming to provide potential investigative strategies for the early diagnosis, treatment approaches, and prognostic enhancement of AIS.
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Aminoácidos , AVC Isquêmico , Humanos , Aminoácidos/metabolismo , AVC Isquêmico/metabolismo , AnimaisRESUMO
The pathogenesis of glioma has remained unclear. In this study, it was found that high expression of the outer dense fibers of sperm tail 3B (ODF3B) in gliomas was positively correlated with the grade of glioma. The higher the grade, the worse the prognosis. ODF3B is closely related to the growth and apoptosis of glioma. In terms of mechanism, ODF3B was found to affect the proliferation and apoptosis of glioma through the JAK1 and JAK2/STAT3 pathways. ODF3B was also found to affect the growth and apoptosis of glioma in vivo. We conclude that ODF3B affects glioma proliferation and apoptosis via the JAK/STAT pathway and is a potential therapeutic target.
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Ethylene (C2H4) purification and propylene (C3H6) recovery are highly relevant in polymer synthesis, yet developing physisorbents for these industrial separation faces the challenges of merging easy scalability, economic feasibility, high moisture stability with great separation efficiency. Herein, we reported a robust and scalable MOF (MAC-4) for simultaneous recovery of C3H6 and C2H4. Through creating nonpolar pores decorated by accessible N/O sites, MAC-4 displays top-tier uptakes and selectivities for C2H6 and C3H6 over C2H4 at ambient conditions. Molecular modelling combined with infrared spectroscopy revealed that C2H6 and C3H6 molecules were trapped in the framework with stronger contacts relative to C2H4. Breakthrough experiments demonstrated exceptional separation performance for binary C2H6/C2H4 and C3H6/C2H4 as well as ternary C3H6/C2H6/C2H4 mixtures, simultaneously affording record productivities of 27.4 and 36.2â L kg-1 for high-purity C2H4 (≥99.9 %) and C3H6 (≥99.5 %). MAC-4 was facilely prepared at deckgram-scale under reflux condition within 3â hours, making it as a smart MOF to address challenging gas separations.
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BACKGROUND: Epigenetic alteration plays an essential role in the occurrence and development of extranodal natural killer/T cell lymphoma (ENKTL). Histone methyltransferase (HMT) KMT2D is an epigenetic regulator that plays different roles in different tumors, but its role and mechanism in ENKTL are still unclear. METHODS: We performed immunohistochemical staining of 112 ENKTL formalin-fixed paraffin-embedded (FFPE) samples. Then, we constructed KMT2D knockdown cell lines and conducted research on cell biological behavior. Finally, to further investigate KMT2D-mediated downstream genes, ChIP-seq and ChIP -qPCR was performed. RESULTS: The low expression of KMT2D was related to a decreased abundance in histone H3 lysine 4 mono- and trimethylation (H3K4me1/3). In KMT2D knockdown YT and NK-YS cells, cell proliferation was faster (P < 0.05), apoptosis was decreased (P < 0.05), the abundance of S phase cells was increased (P < 0.05), and the level of H3K4me1 was decreased. Notably, ChIP-seq revealed two crucial genes and pathways downregulated by KMT2D. CONCLUSIONS: KMT2D is a tumor suppressor gene that mediates H3K4me1 and influences ENKTL proliferation and apoptosis by regulating the cell cycle. Moreover, in ENKTL, serum- and glucocorticoid-inducible kinase-1 (SGK1) and suppressor of cytokine signaling-1 (SOCS1) are downstream genes of KMT2D.
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Linfoma Extranodal de Células T-NK , Humanos , Histona Metiltransferases , Linfoma Extranodal de Células T-NK/patologia , Carcinogênese/genética , Proteína 1 Supressora da Sinalização de CitocinaRESUMO
Herein, we present a decarboxylative thiocarbonylation of aryl and alkenyl sulfonium salts with oxalic acid monothioethers (OAMs), which can be achieved by visible light-accelerated palladium catalysis. Sulfonium salts are widely available, and OAM is an easily accessible and stored reagent; this mild reaction method can also be used for the synthesis of different types of thioester compounds. The reaction represents a new application of visible light-accelerated palladium catalysis in catalytic decarboxylative cross-couplings.
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Extranodal natural killer/T-cell lymphoma (ENKTL) with hepatosplenic involvement is rare, accounting for approximately 0.2% of ENKTL cases. The clinicopathologic features of ENKTL with hepatosplenic involvement are still poorly understood. Seven cases of ENKTL with hepatosplenic involvement were investigated retrospectively by clinical features, pathology, immunophenotype, genotype, Epstein-Barr virus (EBV) status, and survival analysis. The median age was 36 years; three patients (3/7) had a history of primary nasal ENKTL. Six cases (6/7) presented liver or spleen structures that were replaced by neoplasms, and the neoplastic cells displayed diffuse infiltration; one case (1/7) displayed neoplastic cells scattered in hepatic sinuses and portal areas. The cellular morphology and immunohistochemical features were similar to those of ENKTL involving other sites. Follow-up data were available in five of the seven patients. All five patients received first-line chemotherapy based on L-asparaginase. Three patients died, and two were still alive by the last follow-up. The median overall survival (OS) was 21 months. ENKTL with hepatosplenic involvement is rare, regardless of whether it is initial or secondary. There are two histopathologic patterns of ENKTL with hepatosplenic involvement, and L-asparaginase-based chemotherapy combined with AHSCT might yield good efficacy. Morphological features of ENKTL in the spleen and liver A The architecture of the spleen was affected, and dense infiltration of the neoplastic cells was observed in the left part; B Focal infiltration of the neoplastic cells was located in the red pulp; C Dense infiltration of the neoplastic cells in the liver, accompanied by fatty change of hepatocytes and congestion; D More neoplastic cells accumulated in sinusoidal region.
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Infecções por Vírus Epstein-Barr , Linfoma Extranodal de Células T-NK , Humanos , Adulto , Estudos Retrospectivos , Infecções por Vírus Epstein-Barr/complicações , Linfoma Extranodal de Células T-NK/patologia , Asparaginase , Herpesvirus Humano 4 , Células Matadoras Naturais/patologiaRESUMO
Implementing the dual-ligand strategy, a microporous Zn-based MOF 1 with nitro and amino groups was effectively produced. The activated interconnected pores of 1 exhibited high C2H2 uptake capacity and preferential adsorption behaviour for C2H2 over CO2, as identified by the experiments and simulations. This work provides a new approach for designing and synthesizing the MOFs with desired structures and properties by optimizing their pore environment via the dual-ligand strategy.
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BACKGROUND: Anaplastic lymphoma kinase (ALK)-positive histiocytosis, a novel rare histiocytic proliferation, was first described in 2008; it occurs in early infancy with liver and hematopoietic involvement. The spectrum was subsequently broadened to include localized diseases in older children and young adults. However, its full clinicopathological features and molecular lineage have not been fully elucidated. RESULTS: Here, we report four cases of multisystem ALK-positive histiocytosis without hematopoietic involvement. Clinically, three patients were adults aged between 32 and 51 years. Two patients', whose main manifestations were intracranial mass and numerous micronodules in the thoracoabdominal cavity organs and skin papules respectively, had a partial response to ALK inhibitors after surgery. One patient presented with mediastinal neoplasm without surgical treatment, and progressive disease occurred after two years of ALK inhibitor therapy. The fourth patient was a 17-month-old male with a large intracranial mass and presented with a poor response to ALK inhibitor and chemoradiotherapy; he died eight months after surgery. Pathologically, the histiocytes were large, with abundant eosinophilic cytoplasm, and mixed with variable numbers of foamy cells and Touton giant cells. Interstitial fibrosis was also observed. Histiocytes were positive for macrophage markers (CD68 and CD163) and ALK. KIF5B-ALK fusions were detected in two cases, EML4-ALK in one, and both DCTN1-ALK and VRK2-ALK fusions were detected in one case. CONCLUSIONS: We observed that ALK inhibitors present robust and durable responses in adult patients but a poor response in young children with central nervous system involvement. There is no consensus on the optimal treatment regimen and long-term prognosis requires further observation. Moreover, every unusual histiocytic proliferative lesion, especially unresectable and multisystem involvement, should be routinely tested for ALK immunohistochemical staining to identify this rare disease.
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Histiocitose , Adulto , Pré-Escolar , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Histiócitos/patologia , Histiocitose/genética , Histiocitose/patologia , Fígado/patologia , Prognóstico , Receptores Proteína Tirosina QuinasesRESUMO
BACKGROUND: Osteopetrosis is a rare genetic disorder characterized by increased bone density due to defective bone resorption of osteoclasts. Approximately, 80% of autosomal dominant osteopetrosis type II (ADO-II) patients were usually affected by heterozygous dominant mutations in the chloride voltage-gated channel 7 (ClCN7) gene and present early-onset osteoarthritis or recurrent fractures. In this study, we report a case of persistent joint pain without bone injury or underlying history. CASE SUMMARY: We report a 53-year-old female with joint pain who was accidentally diagnosed with ADO-II. The clinical diagnosis was based on increased bone density and typical radiographic features. Two heterozygous mutations in the ClCN7 and T-cell immune regulator 1 (TCIRG1) genes by whole exome sequencing were identified in the patient and her daughter. The missense mutation (c.857G>A) occurred in the CLCN7 gene p. R286Q, which is highly conserved across species. The TCIRG1 gene point mutation (c.714-20G>A) in intron 7 (near the splicing site of exon 7) had no effect on subsequent transcription. CONCLUSION: This ADO-II case had a pathogenic CLCN7 mutation and late onset without the usual clinical symptoms. For the diagnosis and assessment of the prognosis for osteopetrosis, genetic analysis is advised.
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Polycyclic aromatic hydrocarbons (PAHs) are widely present in the environment as toxic pollutants. In this study, quantum chemistry methods are used to study reactions of PAHs in both particle and gas phases. Seven theoretical methods are exploited to predict the reactive sites of 15 PAHs in the particle phase. Among these methods, the performance of the condensed Fukui function (CFF) is optimum. The gas-phase reactions of eight PAHs are also investigated. Except for fluorene, CFF predicts correctly the gas-phase mono-nitro products for seven systems. The products of fluorene predicted by CFF are 1-nitrofluorene and 3-nitrofluorene, which is however inconsistent with the experimental results. Transition state theory is then used to investigate the reaction mechanism of fluorene. Calculated rate constants for 3-nitrofluorene and 2-nitrofluorene formation are much bigger than that for 1-nitrofluorene formation, which is in agreement with the experimental results.
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AIM: Postoperative pain has adverse effects on children with urological problems, including sleep disturbances, incision dehiscence, bleeding and delayed recovery. Accurate parental assessment of children's behaviours and responses could help to manage postoperative pain. We aimed to implement evidence-based practice for parental involvement in a urology ward, to increase parents' participation in children's postoperative pain management. DESIGN: The project was conducted in a paediatric urology ward using the framework and methods of the Fudan University Evidence-Based Nursing Center's Evidence-based Continuous Quality Improvement Model. METHODS: Fifteen audit criteria were used to represent best practice recommendations for parental involvement in postoperative pain management. A pre-implementation audit was conducted with 211 randomly sampled children and parents. Obstacles, promoting factors and key strategies were analysed, and evidence-based interventions implemented to improve compliance. A follow-up audit using the same audit criteria was conducted with 202 children and parents to assess the effect of targeted strategies on compliance with best practice. The SQUIRE guidelines were followed. RESULTS: At the baseline audit, compliance with the evidence-based criteria was 0%-71.5%; only five audit criteria achieved a compliance rate > 60%. After best practice implementation, the follow-up audit showed compliance improvements for all criteria; compliance for three criteria improved to 100%. PATIENT OR PUBLIC CONTRIBUTION: This best practice implementation project improved parents' participation in children's postoperative pain management. The findings demonstrate how audits can promote best practice in postoperative pain management for children. Additional studies will be conducted to address children's postoperative life quality based on best practice.
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Urologia , Humanos , Criança , Hospitais , Dor Pós-Operatória , Enfermagem Baseada em Evidências , PaisRESUMO
P53 prognostic cut-off values differ between studies of mantle cell lymphoma (MCL), and its immunohistochemistry (IHC) interpretation is still based on semiquantitative estimation, which might be inaccurate. This study aimed to investigate the optimal cut-off value for p53 in predicting prognosis of patients with MCL and the possible use of computer image analysis to identify the positive rate of p53. We calculated p53 positive rate using QuPath software and compared it with the data obtained by manual counting and semiquantitative estimation. Survival curves were generated by using the Youden index and the Kaplan-Meier method. The chi-squared (χ2) test was used to compare MIPI, Ann Arbor stage, and cell morphology with p53. Spearman rank correlation test and Bland-Altman analysis were used to compare manual counting, computer image analysis and semiquantitative estimation, as well as the consistency between different observers. The optimal cut-off value of p53 for predicting prognosis was 20% in MCL patients. Patients with p53 ≥ 20% had a significantly worse overall survival (OS) than those with p53 < 20% (P < 0.0001). MCL patients with MIPI intermediate to high risk, Ann Arbor stage III-IV, and blastoid/pleomorphic variant cell morphology had more p53 ≥ 20%. There was a strong correlation between computer image analysis and manual counting of p53 from the same areas in MCL tissues (Spearman's rho = 0.966, P < 0.0001). The results of computer analysis are completely consistent between observers, and computer image analysis of Ki-67 can predict the prognosis of MCL patients. MCL patients with p53 ≥ 20% had a shorter OS and a tendency for MIPI intermediate to high risk, Ann Arbor stage III-IV, and blastoid/pleomorphic variant. Computer image analysis could determine the actual positive rate of p53 and Ki-67 and is a more attractive alternative than semiquantitative estimation in MCL.
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Linfoma de Célula do Manto , Proteína Supressora de Tumor p53 , Adulto , Humanos , Processamento de Imagem Assistida por Computador , Antígeno Ki-67/análise , Linfoma de Célula do Manto/diagnóstico , Linfoma de Célula do Manto/patologia , PrognósticoRESUMO
The SARS-CoV-2 pandemic has become a severe global public health event, and the development of protective and therapeutic strategies is urgently needed. Downregulation of angiotensin converting enzyme 2 (ACE2; one of the important SARS-CoV-2 entry receptors) and aberrant inflammatory responses (cytokine storm) are the main targets to inhibit and control COVID-19 invasion. Silver nanomaterials have well-known pharmaceutical properties, including antiviral, antibacterial, and anticancer properties. Here, based on a self-established metal evaporation-condensation-size graded collection system, smaller silver particles reaching the Ångstrom scale (AgÅPs) were fabricated and coated with fructose to obtain a stabilized AgÅP solution (F-AgÅPs). F-AgÅPs potently inactivated SARS-CoV-2 and prevented viral infection. Considering the application of anti-SARS-CoV-2, a sterilized F-AgÅP solution was produced via spray formulation. In our model, the F-AgÅP spray downregulated ACE2 expression and attenuated proinflammatory factors. Moreover, F-AgÅPs were found to be rapidly eliminated to avoid respiratory and systemic toxicity in this study as well as our previous studies. This work presents a safe and potent anti-SARS-CoV-2 agent using an F-AgÅP spray.
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Enzima de Conversão de Angiotensina 2 , Tratamento Farmacológico da COVID-19 , Humanos , Peptidil Dipeptidase A/metabolismo , SARS-CoV-2 , Prata/farmacologiaRESUMO
Background and Aims: The clinical outcome of relapsed and refractory (RR) extranodal natural killer/T-cell lymphoma (ENKTL) is poor. It is necessary to identify RR patients in ENKTL and find novel therapeutic targets to improve the prognosis of patients with RR ENKTL. Methods: A total of 189 ENKTL patients with effective clinical characteristics were enrolled. Paraffin specimens were collected for PD-L1 expression identification. Kaplan-Meier curve analysis was performed for survival analysis. Whole exome sequencing (WES) was performed for identifying the mutational characterization of RR and effective treatment (ET) patients. Results: Univariate and multivariate Cox proportional hazards regression analysis showed that negative PD-L1 expression (HR = 1.132, 95% CI = 0.739-1.734, P = 0.036) was an independent predictor of poor prognosis in patients with ENKTL. The overall survival (OS) of PD-L1 positive patients was significantly higher than that of PD-L1 negative patients (P = 0.009). Then, we added PD-L1 expression as a risk factor to the model of Prognostic Index of Natural Killer Lymphoma (PINK), and named as PINK+PD-L1. The PINK+PD-L1 model can significantly distinguish RR patients, ET patients, and the whole cohort. Moreover, our data showed that PD-L1 expression was lower than 25% in most RR patients, suggesting that RR subtypes may be associated with low expression of PD-L1 (P = 0.019). According to the whole exome sequencing (WES), we found that the mutation frequencies of JAK-STAT (P = 0.001), PI3K-AKT (P = 0.02) and NF-kappa B (P < 0.001) pathways in RR patients were significantly higher than those in ET patients. Conclusion: Patients tend to show RR when PD-L1 expression is lower than 25%. The model of PINK+PD-L1 can stratify the risk of different groups and predict OS in ENKTL patients. The mutational profile of ENKTL patients with RR is different from that of patients with ET.
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BACKGROUND: Hypertension is a public health problem globally. Understanding the perceived challenges of low-income older people populations with chronic disease is an obstacle the world is facing today. AIM: To explore perceived challenges of self-management in low-income older people with hypertension. METHODS: Data were collected in three communities from September 2019 to October 2019 by semi-structured interviews. Interviews were audio-taped by digital voice recorder and analysed according to Colaizzi's seven steps. RESULTS: Participants demonstrated perceived challenges concerning hypertension self-management. Six themes were identified: hypertension belief bias, family dysfunction, deep-rooted habit, elder self-neglect, medical informatization and supportive health policy. Each theme was identified with several subthemes. CONCLUSIONS: Findings implied that most of the low-income older people lacked self-management behaviours. Future research is needed to address perceived challenges related to self-management behaviour for patients with hypertension worldwide.
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Hipertensão , Autogestão , Idoso , Política de Saúde , Humanos , Hipertensão/terapia , Pobreza , Pesquisa QualitativaRESUMO
Recently, the development of porous absorbents for efficient CO2 and I2 capture has attracted considerable attention because of severe global climate change and environmental issues with the nuclear energy. Hence, a unique porous metal-organic framework (MOF), {[Co(L)]·DMF·2H2O}n (1, DMF = N,N-dimethylformamide) with uncoordinated N atoms was rationally constructed via using a heterofunctional 4,6-bis(4'-carboxyphenyl)pyrimidine (H2L) linker. Interestingly, 1 exhibits exceptional properties for I2 sorption, CO2 capture, and catalytic conversion. Particularly, I2 can be efficiently removed in both vapor and solution forms, and the adsorption amount can reach 676.25 and 345.28 mg g-1, respectively. Furthermore, complex 1 displays high adsorption capacity for CO2 (53.78 cm3 g-1, 273 K). Consequently, 1 is expected to be a promising and practical material for environmental purification due to its excellent adsorption properties.
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ABSTRACT: Acute respiratory distress syndrome (ARDS) is a life-threatening condition characterized by increased permeability of the alveolar-capillary barrier and impaired alveolar fluid clearance. Resolvin E1 (RvE1) is a specialized pro-resolving mediator derived endogenously from omega-3-polyunsaturated fatty acids. RvE1 (10âµg/kg i.v.) was injected to rats 6 h post-lipopolysaccharide (LPS) (14 mg/kg) induction. After another 3 h, alveolar fluid clearance was measured in live rats (nâ=â8-9). The primary Type II alveolar epithelial cell was isolated and treated by LPS (1âµg/mL) with or without RvE1 (250ânM). The expression of epithelial sodium channel (ENaC), Na+/K+-ATPase (NKA), AKT, serum- and glucocorticoid-induced kinase 1 (SGK1), and Nedd4-2 were detected. RvE1 improved survival rate (30% vs. 70%, Pâ=â0.048), increased the clearance of alveolar fluid (13.34% vs. 18.73%, Pâ <â0.001), reduced lung wet-dry weight ratio (5.01 vs. 4.63, Pâ <â0.001), mitigated lung injury scores (13.38 vs. 7.0, Pâ <â0.05) and inflammation in LPS-induced ARDS in rats. RvE1 upregulated alveolar ENaC and NKA expression in vivo and in vitro. In addition, RvE1 significantly increased the expression of phosphorylated AKT, SGK1, and phosphorylated Nedd4-2 in LPS-stimulated primary alveolar type II cells. The effects of RvE1 were abrogated by blocking phosphatidylinositide3'-kinase (PI3K) and SGK1 with LY294002 and GSK650394, respectively. In summary, RvE1 upregulated ENaC and NKA expression by activating PI3K/AKT/SGK1 pathway to promote alveolar fluid clearance, suggesting that RvE1 may be a potentially effective drug for ARDS treatment.
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Lesão Pulmonar Aguda , Síndrome do Desconforto Respiratório , Lesão Pulmonar Aguda/metabolismo , Animais , Ácido Eicosapentaenoico/análogos & derivados , Canais Epiteliais de Sódio/metabolismo , Canais Epiteliais de Sódio/uso terapêutico , Lipopolissacarídeos/toxicidade , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Síndrome do Desconforto Respiratório/tratamento farmacológico , ATPase Trocadora de Sódio-Potássio/efeitos adversos , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
BACKGROUND: To assess the association of HSD17B13 rs72613567:TA allelic variant with liver disease, we performed the current review and meta-analysis. METHODS: Seven studies were identified by a search of CNKI,CBM,MEDLINE, PubMed, EMBASE, and CENTRAL databases from inception to November 2021. Odds ratios (ORs) with 95% confidence interval (CI) were calculated using random effects model or fixed effects model based on the between-study heterogeneity. The Stata 14.0 software was employed for data analysis. RESULTS: Statistical analysis showed that the HSD17B13 rs72613567:TA allelic variant can decrease the risk of hepatocellular carcinoma(HCC) in nonalcoholic fatty liver disease (NAFLD) patients, alcoholic fatty liver disease (ALD) patients and viral hepatitis patients (TA vs T OR = 0.766, 95% CI = 0.682-0.860, P = 0.000; TATA + TAT vs TT OR = 0.755, 95% CI = 0.645-0.885, P = 0.001) or healthy controls(TA vs T OR = 0.649, 95% CI = 0.431-0.977, P = 0.038). Besides, the HSD17B13 rs72613567:TA allelic variant can also provide protection from nonalcoholic fatty liver disease (NAFLD) not only in entire population (TA vs T OR = 0.669, 95% CI = 0.524-0.856, P = 0.001) but also in healthy people (TA vs T OR = 0.600, 95% CI = 0.464-0.777, P = 0.000). No significant publication bias found in this airticle. CONCLUSION: The present findings suggest HSD17B13 rs72613567:TA allelic variant can reduce the risk of HCC and NAFLD in the entire population studied.
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17-Hidroxiesteroide Desidrogenases/genética , Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Alelos , Carcinoma Hepatocelular/genética , Humanos , Neoplasias Hepáticas/genética , Hepatopatia Gordurosa não Alcoólica/genética , Razão de ChancesRESUMO
Forests in Beijing exhibit vulnerability to increasing stress of extreme drought in recent years. To investigate the drought tolerance of different tree species, we chose three tree species (Larix principis-rupprechtii, Pinus tabuliformis, and Quercus wutaishanica) from the forest of Dongling Mountain in Beijing and used dendroecological method to analyze the relationship between radial growth and climate, as well as their resistance and resilience to extreme drought events. Our results showed that the radial growth of L. principis-rupprechtii and P. tabuliformis was significantly negatively correlated with monthly mean temperature from May to June, but that of Q. wutaishanica was significantly negatively correlated with monthly mean temperature only in May. The radial growth of L. principis-rupprechtii was significantly positively correlated with monthly mean precipitation in June, monthly mean relative humidity from May to June and August to September. The radial growth of P. tabuliformis was significantly positively correlated with monthly mean precipitation and monthly mean relative humidity from June to August. The radial growth of Q. wutaishanica was significantly positively correlated with monthly mean precipitation in February and May, and monthly mean relative humidity in May. The radial growth of all the three species was significantly positively correlated with monthly mean SPEI (standardized precipitation evapotranspiration index) from May to July. L. principis-rupprechtii was least drought tolerant, as indicated by the greatest growth reduction (46.6%-69.6%), lowest resistance (0.534, 0.304, 0.530) and resilience (0.686, 0.570, 0.753) during the three extreme drought events occurred in the 1994, 2001-2002, and 2007. In contrast, tree growth of Q. wutaishanica showed the highest drought resistance in 2007, whereas no significant differences were observed between other two species. Extreme drought events caused by continuous high temperature and reduced precipitation during the growing season accounted for the reduction in tree radial growth. The various physiological and ecological strategies of tree species were the possible reasons for the difference in drought tolerance. Our results could provide a basis for the selection of suitable afforestation tree species and the formulation of forest protection mea-sures to maintain forest ecosystem functions and services under the background of undergoing climate change.