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1.
Arch Virol ; 169(5): 115, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38709425

RESUMO

Porcine circoviruses (PCVs) are a significant cause of concern for swine health, with four genotypes currently recognized. Two of these, PCV3 and PCV4, have been detected in pigs across all age groups, in both healthy and diseased animals. These viruses have been associated with various clinical manifestations, including porcine dermatitis and nephropathy syndrome (PDNS) and respiratory and enteric signs. In this study, we detected PCV3 and PCV4 in central China between January 2022 and February 2023. We tested fecal swabs and tissue samples from growing-finishing and suckling pigs with or without respiratory and systemic manifestations and found the prevalence of PCV3 to be 15.15% (15/99) and that of PCV3/PCV4 coinfection to be 4.04% (4/99). This relatively low prevalence might be attributed to the fact that most of the clinical samples were collected from pigs exhibiting respiratory signs, with only a few samples having been obtained from pigs with diarrhea. In some cases, PCV2 was also detected, and the coinfection rates of PCV2/3, PCV2/4, and PCV2/3/4 were 6.06% (6/99), 5.05% (5/99), and 3.03% (3/99), respectively. The complete genomic sequences of four PCV3 and two PCV4 isolates were determined. All four of the PCV3 isolates were of subtype PCV3b, and the two PCV4 isolates were of subtype PCV4b. Two mutations (A24V and R27K) were found in antibody recognition domains of PCV3, suggesting that they might be associated with immune escape. This study provides valuable insights into the molecular epidemiology and evolution of PCV3 and PCV4 that will be useful in future investigations of genotyping, immunogenicity, and immune evasion strategies.


Assuntos
Infecções por Circoviridae , Circovirus , Genótipo , Filogenia , Doenças dos Suínos , Circovirus/genética , Circovirus/isolamento & purificação , Circovirus/classificação , Animais , Suínos , China/epidemiologia , Doenças dos Suínos/virologia , Doenças dos Suínos/epidemiologia , Infecções por Circoviridae/veterinária , Infecções por Circoviridae/virologia , Infecções por Circoviridae/epidemiologia , Coinfecção/virologia , Coinfecção/veterinária , Coinfecção/epidemiologia , Genoma Viral/genética , Fezes/virologia
2.
Metabolites ; 14(4)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38668352

RESUMO

Temperature is vital in plant growth and agricultural fruit production. Litchi chinensis Sonn, commonly known as litchi, is appreciated for its delicious fruit and fragrant blossoms and is susceptible to stress when exposed to low temperatures. This study investigates the effect of two cryoprotectants that counteract cold stress during litchi flowering, identifies the genes that generate the cold resistance induced by the treatments, and hypothesizes the roles of these genes in cold resistance. Whole plants were treated with Bihu and Liangli cryoprotectant solutions to protect inflorescences below 10 °C. The soluble protein, sugar, fructose, sucrose, glucose, and proline contents were measured during inflorescence. Sucrose synthetase, sucrose phosphate synthetase, antioxidant enzymes (SOD, POD, CAT), and MDA were also monitored throughout the flowering stage. Differentially expressed genes (DEGs), gene ontology, and associated KEGG pathways in the transcriptomics study were investigated. There were 1243 DEGs expressed after Bihu treatment and 1340 in the control samples. Signal transduction pathways were associated with 39 genes in the control group and 43 genes in the Bihu treatment group. The discovery of these genes may contribute to further research on cold resistance mechanisms in litchi. The Bihu treatment was related to 422 low-temperature-sensitive differentially accumulated metabolites (DAMs), as opposed to 408 DAMs in the control, mostly associated with lipid metabolism, organic oxidants, and alcohols. Among them, the most significant differentially accumulated metabolites were involved in pathways such as ß-alanine metabolism, polycyclic aromatic hydrocarbon biosynthesis, linoleic acid metabolism, and histidine metabolism. These results showed that Bihu treatment could potentially promote these favorable traits and increase fruit productivity compared to the Liangli and control treatments. More genomic research into cold stress is needed to support the findings of this study.

3.
Phytomedicine ; 128: 155385, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38569292

RESUMO

BACKGROUND: Xianlian Jiedu Decoction (XLJDD) has been used for the treatment of colorectal cancer (CRC) for several decades because of the prominent efficacy of the prescription. Despite the clear clinical efficacy of XLJDD, the anti-CRC mechanism of action is still unclear. PURPOSE: The inhibitory effect and mechanism of XLJDD on CRC were investigated in the azoxymethane/dextran sulfate sodium (AOM/DSS)-induced mice. METHODS: The AOM/DSS-induced mice model was adopted to evaluate the efficacy after administering the different doses of XLJDD. The therapeutic effects of XLJDD in treating AOM/DSS-induced CRC were investigated through histopathology, immunofluorescence and ELISA analysis methods. In addition, metabolomics profile and 16S rRNA analysis were used to explore the effective mechanisms of XLJDD on CRC. RESULTS: The results stated that the XLJDD reduced the number of tumor growth on the inner wall of the colon and the colorectal weight/length ratio, and suppressed the disease activity index (DAI) score, meanwhile XLJDD also increased body weight, colorectal length, and overall survival rate. The treatment of XLJDD also exhibited the ability to lower the level of inflammatory cytokines in serum and reduce the expression levels of ß-catenin, COX-2, and iNOS protein in colorectal tissue. The findings suggested that XLJDD has anti-inflammatory properties and may provide relief for those suffering from inflammation-related conditions. Mechanistically, XLJDD improved gut microbiota dysbiosis and associated metabolic levels of short chain fatty acids (SCFAs), sphingolipid, and glycerophospholipid. This was achieved by reducing the abundance of Turicibacter, Clostridium_sensu_stricto_1, and the levels of sphinganine, LPCs, and PCs. Additionally, XLJDD increased the abundance of Enterorhabdus and Alistipes probiotics, as well as the content of butyric acid and isovaleric acid. CONCLUSION: The data presented in this article demonstrated that XLJDD can effectively inhibit the occurrence of colon inner wall tumors by reducing the level of inflammation and alleviating intestinal microbial flora imbalance and metabolic disorders. It provides a scientific basis for clinical prevention and treatment of CRC.


Assuntos
Azoximetano , Neoplasias Colorretais , Sulfato de Dextrana , Medicamentos de Ervas Chinesas , Microbioma Gastrointestinal , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Camundongos , Masculino , Modelos Animais de Doenças , Metaboloma/efeitos dos fármacos , Colo/efeitos dos fármacos , Colo/patologia , Colo/microbiologia
4.
Phytomedicine ; 109: 154574, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36610161

RESUMO

BACKGROUND: Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Abnormal activation of NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome plays a vital role in the pathogenesis of sepsis. Matrine is proved to show good anti-inflammatory properties, whereas its effect and the underlying molecular machinery on sepsis remains unclear. PURPOSE: The aim of this study is to evaluate the effect and mechanism of Matrine on sepsis. STUDY DESIGN: THP-1 cells and J774A.1 cells were stimulated by lipopolysaccharide (LPS) with nigericin or adenosine triphosphate (ATP) to establish an in vitro model. Cecal ligation and puncture (CLP)-induced sepsis mouse model was used. Matrine was given by gavage. METHODS: To investigate the NLRP3 inflammasome activation, phorbol myristate acetate (PMA)-induced THP-1 cells were first primed with LPS and then stimulated by matrine, followed by treatment with nigericin or ATP. The concentration of interleukin 1ß (IL-1ß) and interleukin 18 (IL-18) in the cell culture supernatant was detected. The mechanism was explored by cell death assay, immunoblots and immunofluorescence in vitro. C57BL/6 mice were intragastrically administered with matrine for 5 days before CLP. The therapeutic effect of matrine was evaluated by symptoms, pathological analysis, ELISA and RT-qPCR. RESULTS: Our results revealed that matrine inhibited IL-1ß and IL-18 secretion, suppressed caspase-1 activation, reduced cell death, and blocked ASC speck formation upon NLRP3 inflammasome activation. Furthermore, matrine restrains NLRP3 inflammasome activation as well as pyroptosis through regulating the protein tyrosine phosphatase non-receptor type 2 (PTPN2)/JNK/SREBP2 signaling. Matrine also prominently improved the symptoms and pathological changes with reduced levels of TNF-α, IL-1ß, and IL-6 in the lung tissues and serum in a dose-dependent manner. CONCLUSION: Matrine effectively alleviates the symptoms of CLP-induced sepsis in mice, restrains NLRP3 inflammasome activation by regulating PTPN2/JNK/SREBP2 signaling pathway, and may become a promising therapeutic agent for sepsis treatment.


Assuntos
Inflamassomos , Sepse , Camundongos , Animais , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Interleucina-18 , Matrinas , Proteína Tirosina Fosfatase não Receptora Tipo 2 , Lipopolissacarídeos/farmacologia , Nigericina , Camundongos Endogâmicos C57BL , Sepse/tratamento farmacológico , Sepse/metabolismo , Trifosfato de Adenosina , Interleucina-1beta/metabolismo
5.
J Ethnopharmacol ; 303: 116031, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36503032

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Shen-Qi-Jiang-Tang granule (SQJTG), a classic traditional Chinese medicine (TCM) prescription, has been widely used in clinical for diabetes, especially type Ⅱ diabetes. Previous anti-diabetic studies stumbled across that SQJTG has a potential kidney protective effect on diabetic nephropathy (DN). However, the protective mechanism of SQJTG on DN still needs to be explored. AIM OF THE STUDY: The purpose of the present study was to explore the therapeutic effect of SQJTG on DN through both bioinformatics analysis and in vivo experiments. METHODS AND MATERIALS: The TCMIP database was used for screening potential compounds and targets of SQJTG, and the GeneCards, OMIM, DrugBank, and TTD databases were used for collecting DN-related genes. Then protein-protein interaction analysis for the common targets of SQJTG and DN was performed by the STRING database. Meanwhile, KEGG and GO were carried out using the Metascape and DAVID databases. In vivo experiments, to testify the potential kidney protective effects of SQJTG, STZ-induced DN mice with different dosages of SQJTG treatment were collected and the renal tissues were detected by H&E, PAS, Masson and TUNEL staining. Immunohistochemistry and immunoblotting were used to assess the proteins' expressions. Flow cytometry and ELISA assay were used to detect the levels of pro-inflammatory cytokines. RESULTS: Among the 338 compounds ascertained by SQJTG, there were 789 related targets as well. Moreover, 1,221 DN-related targets were predicted and 20 core targets were screened by the PPI analyses. According to GO and KEGG pathway analysis, SQJTG may affect DN via the TNF pathway. For the in vivo experiments, renal histomorphological examinations demonstrated that SQJTG treatment significantly ameliorated STZ-induced kidney damage and had a dosage dependence. Meanwhile, mice with DN were found to have dramatic increases in IL-1, TNF-α, IL-6, and IL-12, but markedly decreased after administration of SQJTG. In addition, the protein levels of TNF signaling molecules, like p-P65, p-JNK, and p-p38, showed significantly elevated in kidney tissues of DN mice and attenuated after SQJTG treatment. CONCLUSIONS: SQJTG exerts a kidney protective effect in DN mice via modulating TNF signaling pathways, and it has promising applications for the treatment of DN.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Camundongos , Animais , Nefropatias Diabéticas/patologia , Diabetes Mellitus Experimental/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo
6.
Front Microbiol ; 13: 1040846, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36406423

RESUMO

Diabetes-specific microvascular disease is a leading cause of blindness, renal failure and nerve damage. Epidemiological data demonstrated that the high morbidity of T2DM occurs as a result of obesity and gradually develops into serious complications. To date, the mechanisms that underlie this observation are still ill-defined. In view of the effect of obesity on the gut microflora, Leprdb/db mice underwent antibiotic treatment and microbiota transplants to modify the gut microbiome to investigate whether microbes are involved in the development of diabetic nephropathy (DN) and/or diabetic retinopathy (DR). The mouse feces were collected for bacterial 16S ribosomal RNA gene sequencing. Cytokines including TNF-α, TGF-ß1, IFN-γ, IL-1ß, IL-6, IL-17A, IL-10, and VEGFA were detected by enzyme-linked immunosorbent assay (ELISA), flow cytometry, real-time PCR and immunofluorescent assay. Eyes and kidney were collected for histopathological assay. Intestinal permeability was also detected using Evans Blue. The results showed that obesity influenced metabolic variables (including fast/fed glucose, insulin, and triglyceride), retinopathy and nephropathy, and the gut microbiota. Obesity mainly reduced the ratio of Bacteroidetes/Firmicutes and influenced relative abundance of Proteobacteria, Actinobacteria, and Spirochetes. Obesity also increased intestinal permeability, metabolic endotoxemia, cytokines, and VEGFA. Microbiota transplants confirm that obesity aggravates retinopathy and nephropathy through the gut microbiota. These findings suggest that obesity exacerbates retinopathy and nephropathy by inducing gut microbiota dysbiosis, which further enhanced intestinal permeability and chronic low-grade inflammation.

7.
Eur J Pharmacol ; 934: 175293, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36167152

RESUMO

OBJECTIVE: Myocardial infarction is the highest cause of cardiovascular death. Previous studies found that patients with myocardial infarction have elevated serum IL-37 and IL-37 treatment significantly alleviates adverse remodeling in myocardial infarction mice. However, the underlying mechanism of IL-37 in myocardial infarction is still unknown. Here we explored the underlying mechanism of IL-37 in attenuating myocardial infarction. METHODS: The myocardial infarction mice model was constructed by left anterior descending ligation and then submitted to recombinant IL-37 administration. The histology and cardiac function were detected by HE & Masson staining and echocardiography, respectively. The macrophage phenotypes were analyzed by flow cytometry and real-time PCR. The cytokines in serum and cell culture supernatant were determined by ELISA. In addition, THP-1 cells were used in vitro to investigate the underlying mechanisms. RESULTS: Infarcted mice showed increased inflammatory cell infiltration and impaired cardiac function. IL-37 treatment alleviated pro-inflammatory macrophage infiltration, tissue injury, and collagen deposition in hearts on day 3 and 7 after infarction in mice. In addition, IL-37 application modulated the balance between M1 and M2 macrophages in infarcted hearts. In vitro, THP-1 cell line polarization was also regulated by IL-37, companied by YAP phosphorylation and NLRP3 inactivation. Verteporfin, a YAP inhibitor, could abolish IL-37-induced NLRP3 inhibition and M2 macrophage polarization. CONCLUSION: Our results demonstrated that IL-37 achieves a favorable therapeutical function on myocardial infarction by modulating YAP-NLRP3 mediated macrophage programming, providing a promising drug for the treatment of myocardial infarction.


Assuntos
Infarto do Miocárdio , Proteína 3 que Contém Domínio de Pirina da Família NLR , Camundongos , Animais , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Miocárdio/metabolismo , Verteporfina , Infarto do Miocárdio/patologia , Macrófagos/metabolismo , Citocinas/metabolismo
8.
Phytomedicine ; 87: 153590, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34033998

RESUMO

BACKGROUND: Inflammatory bowel disease (IBD) is an autoimmune disease. The pathogenesis of IBD is complicated and intestinal mucosal barrier damage is considered as the trigger factor for the initiation and recurrence of IBD. Total Glucosides of Paeony (TGP) has shown good inhibitory effects on immune-inflammation in clinic studies. However, its effect and mechanism on IBD are largely unknown. PURPOSE: The purpose of this study is to evaluate the effect and mechanism of TGP on IBD. STUDY DESIGN: DSS-induced colitis mouse model was used. TGP was given by gavage. Caco-2 cells were stimulated by outer membrane vesicles (OMV) to establish an in vitro model. METHODS: C57BL/6 mice were divided into normal control group, model group, mesalazine group, paeoniflorin (PA) group, high-dose group of TGP, and low-dose group of TGP. The model was induced with 2.5% DSS for 7 days, and TGP was intragastrically administered for 10 days. The therapeutic effect of TGP was evaluated by symptoms, histochemical analysis, RT-qPCR and ELISA. The mechanism was explored by intestinal permeability, Western blot and immunofluorescence in vivo and in vitro. RESULTS: Our results showed that TGP could significantly improve the symptoms and pathological changes, with reduced levels of TNF-α, IL-17A, IL-23 and IFN-γ in the colon tissues and serum under a dose-dependent manner. TGP also reduced the intestinal permeability and restored the protein expression of tight junction and adherens junction proteins of intestinal epithelial cells in vivo and in vitro. Furthermore, TGP could inhibit the expression of p-Lyn and Snail and prevent Snail nuclear localization, thereby maintaining tight and adherens junctions. CONCLUSION: TGP effectively improves the symptoms of DSS-induced colitis in mice, protects the intestinal epithelial barrier by inhibiting the Lyn/Snail signaling pathway, and maybe a promise therapeutic agent for IBD treatment.


Assuntos
Colite/tratamento farmacológico , Glucosídeos/farmacologia , Paeonia/química , Quinases da Família src/metabolismo , Animais , Células CACO-2 , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Glucosídeos/química , Humanos , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Monoterpenos/farmacologia , Permeabilidade , Fatores de Transcrição da Família Snail/metabolismo , Proteínas de Junções Íntimas/metabolismo , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo
9.
Circ Res ; 127(4): 534-549, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32316875

RESUMO

RATIONALE: SNX10 (sorting nexin 10) has been reported to play a critical role in regulating macrophage function and lipid metabolism. OBJECTIVE: To investigate the precise role of SNX10 in atherosclerotic diseases and the underlying mechanisms. METHODS AND RESULTS: SNX10 expression was compared between human healthy vessels and carotid atherosclerotic plaques. Myeloid cell-specific SNX10 knockdown mice were crossed onto the APOE-/- (apolipoprotein E) background and atherogenesis (high-cholesterol diet-induced) was monitored for 16 weeks. We found that SNX10 expression was increased in atherosclerotic lesions of aortic specimens from humans and APOE-/- mice. Myeloid cell-specific SNX10 deficiency (Δ knockout [KO]) attenuated atherosclerosis progression in APOE-/- mice. The population of anti-inflammatory monocytes/macrophages was increased in the peripheral blood and atherosclerotic lesions of ΔKO mice. In vitro experiments showed that SNX10 deficiency-inhibited foam cell formation through interrupting the internalization of CD36, which requires the interaction of SNX10 and Lyn-AKT (protein kinase B). The reduced Lyn-AKT activation by SNX10 deficiency promoted the nuclear translocation of TFEB (transcription factor EB), thereby enhanced lysosomal biogenesis and LAL (lysosomal acid lipase) activity, resulting in an increase of free fatty acids to fuel mitochondrial fatty acid oxidation. This further promoted the reprogramming of macrophages and shifted toward the anti-inflammatory phenotype. CONCLUSIONS: Our data demonstrate for the first time that SNX10 plays a crucial role in diet-induced atherogenesis via the previously unknown link between the Lyn-Akt-TFEB signaling pathway and macrophage reprogramming, suggest that SNX10 may be a potentially promising therapeutic target for atherosclerosis treatment.


Assuntos
Doenças da Aorta/metabolismo , Aterosclerose/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Reprogramação Celular/fisiologia , Macrófagos/fisiologia , Nexinas de Classificação/fisiologia , Animais , Apolipoproteínas E/genética , Aterosclerose/sangue , Aterosclerose/patologia , Antígenos CD36/metabolismo , Núcleo Celular/metabolismo , Progressão da Doença , Ácidos Graxos não Esterificados/metabolismo , Células Espumosas/citologia , Humanos , Lisossomos/fisiologia , Macrófagos/citologia , Camundongos , Mitocôndrias/metabolismo , Monócitos/citologia , Oxirredução , Proteínas Proto-Oncogênicas c-akt/metabolismo , Nexinas de Classificação/deficiência , Nexinas de Classificação/genética , Esterol Esterase/metabolismo
10.
Phytomedicine ; 65: 153091, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31654988

RESUMO

BACKGROUND: The development of rheumatoid arthritis (RA) is related to germinal center (GC) response and autoreactive T cells, which mediate adaptive immunity and play an important role in stimulating the production of autoantibodies and pro-inflammatory cytokines by B cells and macrophages. Total Glucosides of Paeony (TGP) has anti-inflammatory, immunomodulatory and analgesic effects and is widely used to treat RA. However, few studies investigated whether the therapeutic effect of TGP is associated with the inhibition of autoimmune response. PURPOSE: The aim of this study was to investigate the effects and mechanisms of TGP on RA. STUDY DESIGN: Type II collagen-induced arthritis (CIA) mouse model was used, and TGP and paeoniflorin were intragastrically treated. METHODS: DBA/1 mice were divided into 5 groups: control, model, positive drug (paeoniflorin) and high- and low-dose TGP group. After 21 days of intragastric administration, the pathological change, inflammation expression and molecular mechanism of each group of mice were detected by Micro-CT, histochemical analysis, ELLSA, Western blot, RT-qPCR and flow cytometry. RESULTS: Our study found that TGP treatment effectively improved inflammation and joint destruction in CIA mice. It reduced the production of serum IgG2a and pro-inflammatory cytokines, including serum interleukin (IL)-21, tumor necrosis factor (TNF)-α and IL-6, and the phosphorylation of NF-κB p65 and STAT3 in a dose-dependent manner. More importantly, TGP could suppress the frequency of germinal center B cells and Tfh cells in the spleen. CONCLUSION: TGP can not only improve symptoms, but also inhibit bone destruction. The therapeutic effect of TGP on CIA is mainly achieved by inhibiting spleen Tfh cell differentiation and GC formation through STAT3 signaling pathway.


Assuntos
Artrite Experimental/tratamento farmacológico , Glucosídeos/farmacologia , Paeonia/química , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Animais , Artrite Experimental/imunologia , Artrite Experimental/patologia , Diferenciação Celular/efeitos dos fármacos , Citocinas/sangue , Imunoglobulina G/sangue , Masculino , Camundongos Endogâmicos DBA , NF-kappa B/metabolismo , Fosforilação/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Fator de Transcrição STAT3/metabolismo , Baço/efeitos dos fármacos , Baço/imunologia , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
11.
Huan Jing Ke Xue ; 38(8): 3146-3152, 2017 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964920

RESUMO

The on-road emissions of typical alkanes from 11 heavy-duty diesel vehicles with different emission standards (from China Ⅰ to China Ⅳ) were tested using a portable emission measurement system(PEMS) and quantified by gas chromatography-mass spectrometry (GC-MS). Our aim was to analyze the emission characteristics of typical alkanes in heavy-duty diesel vehicle exhaust. The results show that the emission standard significantly affected the emission factors (EFs) of n-alkanes and hopanes. Vehicles with higher emission standards had lower EFs. Compared with China Ⅰ vehicles, the total EFs of n-alkanes, 17α(H),21ß(H)-C30 hopane (C30-hopane), and 22S- and 22R-17α(H),21ß(H)-homohopane (22S-C31 and 22R-C31 homohopane) from China Ⅳ vehicles were significantly reduced by 72.23%, 64.95%, 70.78%, and 74.68%, respectively. The peak carbon numbers of gaseous n-alkanes were 17 to 18, while they were 18 to 21 in particulate n-alkanes. The 22S-C31 homohopane/(22S-C31 homohopane + 22R-C31 homohopane) ratios ranged from 0.46 to 0.56, with an average of 0.50, which conform to the characteristics of hopanes in petroleum. The total EFs of n-alkanes had a good linear relationship with the total EFs of C30-hopane, and the R2 was 0.9268. Furthermore, the driving conditions had a great influence on the emissions of n-alkanes and hopanes. Specifically, the EFs of n-alkanes and hopanes on non-highway roads were 1.69 to 2.42 times greater than those on highways.

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