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1.
J Inflamm Res ; 16: 6155-6166, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38107382

RESUMO

Purpose: To determine the value of intrapulmonary concomitant lesions in differentiating non-neoplastic and neoplastic ground-glass nodules (GGNs). Patients and Methods: From January 2014 to March 2022, 395 and 583 patients with confirmed non-neoplastic and neoplastic GGNs were retrospectively enrolled. Their clinical and chest CT data were evaluated. The CT features of target GGNs and intrapulmonary concomitant lesions in these two groups were analyzed and compared, and the role of intrapulmonary concomitant lesions in improving differentiation was evaluated. Results: The intrapulmonary concomitant lesions were more common in patients with non-neoplastic GGNs than in those with neoplastic ones (87.88% vs 82.18%, P = 0.015). Specifically, patients with non-neoplastic GGNs had a higher incidence of multiple solid nodules (SNs), patchy ground-glass opacity/consolidation, and fibrosis/calcification in any lung fields (each P < 0.05). Logistic regression analysis indicated that patients < 44 years old, diameter < 7.35 mm, irregular shape, and coarse margin or ill-defined boundary for target GGN, pleural thickening, and concomitant SNs in the same lobe and fibrosis or calcification in any lung field were independent indicators for predicting non-neoplastic GGNs. The AUC of the model for predicting non-neoplastic GGNs increased from 0.894 to 0.926 (sensitivity, 83.10%; specificity, 87.10%) after including the concomitant lesions in the patients' clinical characteristics and CT features of target GGNs (P < 0.0001). Conclusion: Besides the patients' clinical characteristics and CT features of target GGNs, the concomitant multiple SNs in the same lobe and fibrosis/calcification in any lung field should be considered in further differentiating non-neoplastic and neoplastic GGNs.

2.
Acta Radiol ; 64(9): 2526-2534, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37464809

RESUMO

BACKGROUND: Some peripheral small cell lung cancers (pSCLCs) and benign lung tumors (pBLTs) have similar morphological features but different treatment and prognosis. PURPOSE: To determine the significance of marginal vessels in differentiating pSCLCs and pBLTs. MATERIAL AND METHODS: A total of 57 and 95 patients with pathological confirmed nodular (≤3 cm) pSCLC and pBLT with similar morphological features were enrolled in this study retrospectively. The patients' clinical characteristics and computed tomography (CT) features of tumors and marginal vessels (vessels connecting with tumors) were analyzed and compared. RESULTS: Compared with pBLTs, pSCLCs had a larger diameter (P = 0.001) but lower enhancement (P = 0.015) and fewer had calcification (P = 0.013). Compared with pBLTs, more lesions had proximal (70.2% vs. 22.1%) and distal (59.6% vs. 4.2%) marginal vessels in pSCLCs (each P < 0.0001). In addition, in pSCLCs, the numbers of proximal (1.3 ± 1.4 vs. 0.3 ± 0.6), distal (2.4 ± 3.1 vs. 0.1 ± 0.5), and total (3.6 ± 3.5 vs. 0.4 ± 1.0) marginal vessels were all more than those in pBLTs (each P < 0.001). Receiver operating characteristic curve analysis revealed the positive distal marginal vessel sign had the highest specificity (95.8%), and the number of total marginal vessels had the best performance in discriminating pSCLC from pBLT (cutoff value = 1.5, AUC = 0.80, 95% CI = 0.72-0.89, sensitivity = 70.2%, and specificity = 91.6%). CONCLUSION: For peripheral solid nodules similar to pBLTs but without any calcification, the possibility of pSCLC should be considered if they have multiple marginal vessels (≥2), especially the distal ones.


Assuntos
Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Estudos Retrospectivos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Tomografia Computadorizada por Raios X/métodos , Carcinoma de Pequenas Células do Pulmão/diagnóstico por imagem , Curva ROC
3.
Zhongguo Zhong Yao Za Zhi ; 46(20): 5351-5361, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34738439

RESUMO

This study aims to predict the material basis and mechanism of Dachengqi Decoction in the treatment of sepsis based on network pharmacology. The chemical constituents and targets of Dachengqi Decoction were retrieved from TCMSP, UniPot and DrugBank and the targets for the treatment of sepsis from OMIM and GeneCards. The potential targets of Dachengqi Decoction for the treatment of sepsis were screened by OmicShare. STRING database and Cytoscape 3.7.2 were used to construct the Chinese medicinal-active component-target-disease, active component-key target-key pathway, and protein-protein interaction(PPT) networks. The gene ontology(GO) term enrichment analysis and Kyoto encyclopedia of genes and genomes(KEGG) pathway enrichment analysis were performed by DAVID(P<0.05). Finally, the animal experiment was conducted to verify some targets and pathways. A total of 40 active components and 157 targets of the Dachengqi Decoction, 2 407 targets for the treatment of sepsis, and 91 common targets of the prescription and the disease were also obtained. The key targets were prostaglandin G/H synthase 2(PTGS2), prostaglandin G/H synthase 1(PTGS1), protein kinase cAMP-dependent catalytic-α(PRKACA), coagulation factor 2 receptor(F2 R), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic gamma subunit(PIK3 CG), dipeptidyl peptidase 4(DPP4), etc. A total of 533 terms and 125 pathways were obtained for the 91 targets. The main terms were the response to drug, negative regulation of apoptotic process, positive regulation of nitric oxide biosynthetic process and lipopolysaccharide-mediated signaling pathway, and the pathways included pathways in cancer, hepatitis B, and phosphatidylinositol 3-kinase and protein kinase B(PI3 K/Akt) signaling pathway. The animal experiment confirmed that Dachengqi Decoction can down-regulate inflammatory cytokines interleukin-1ß(IL-1ß), IL-6 and tumor necrosis factor α(TNF-α)(P<0.01). It could also reduce the wet/dry weight ratio of lung tissue, the level of myeloperoxidase(MPO) and the phosphorylation of PI3 K and Akt(P<0.01). These results indicated that Dchengqi Decoction could act on inflammation-related targets and improve sepsis by inhibiting PI3 K/Akt signaling pathway. The animal experiment supported the predictions of network pharmacology. Dachengqi Decoction intervenes sepsis via multiple components, multiple targets, and multiple pathways. The result lays a foundation for further research on the mechanism of Dachengqi Decoction in the treatment of sepsis.


Assuntos
Medicamentos de Ervas Chinesas , Sepse , Animais , Ontologia Genética , Extratos Vegetais , Sepse/tratamento farmacológico , Sepse/genética
4.
Zhongguo Zhong Yao Za Zhi ; 44(24): 5336-5344, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-32237377

RESUMO

Xanthii Fructus is a traditional Chinese medicine for the treatment of sinusitis and headache,rich in medicinal materials and is widely used for more than 1 800 years. Modern pharmacological studies have showed that Xanthii Fructus has anti-inflammatory,analgesic,anti-tumor,anti-bacterial,hypoglycemic,anti-allergic,immunomodulatory and other pharmacological effects,which can be commonly used in the treatment of diseases relating to immune abnormalities,such as rheumatoid arthritis,acute and chronic rhinitis,allergic rhinitis,and skin diseases,with a high medicinal value. Toxicological studies have shown that Xanthii Fructus poisoning can cause substantial damage to organs,such as the liver,kidney,and gastrointestinal tract,especially to liver. Because of the coexisting of its efficacy and toxicity,Xanthii Fructus often leads to a series of safety problems in the clinical application process. This study attempts to summarize its characteristics of adverse reactions,analyze the root cause of the toxicity of Xanthii Fructus from such aspects as processing,dose,course of treatment and eating by mistake,discuss the substance of its efficacy/toxicity from chemical compositions,and put forward exploratory thinking about how to promote its clinical rational application from the aspects such as strict processing,reasonable compatibility,medication information,contraindication,strict control of the dose,and course of treatment,so as to promote the safe and reasonable application of Xanthii Fructus.


Assuntos
Medicamentos de Ervas Chinesas/efeitos adversos , Frutas/toxicidade , Xanthium/toxicidade , Medicamentos de Ervas Chinesas/uso terapêutico , Humanos , Medicina Tradicional Chinesa
5.
Brain Behav Immun ; 66: 244-256, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28690033

RESUMO

Toll-like receptor 4 (TLR4) and C5aR1 (CD88) have been recognized as potential therapeutic targets for the reduction of inflammation and secondary damage and improvement of outcome after ischemia and reperfusion (I/R). The inflammatory responses which induce cell apoptosis and necrosis after I/R brain injury lead to a limited process of neural repair. To further comprehend how these targets function in I/R state, we investigated the pathological changes and TLR4 and C5aR1 signaling pathways in vitro and in vivo models of I/R brain injury in this study. Meanwhile, we explored the roles of schisantherin A on I/R brain injury, and whether it exerted neuroprotective effects by regulating the TLR4 and C5aR1 signaling pathways or not. The results showed that schisantherin A significantly reduced the neuronal apoptosis induced by oxygen and glucose deprivation and reperfusion (OGD/R) injury in primary culture of rat cortical neurons. Also, schisantherin A alleviated neurological deficits, reduced infarct volume, attenuated oxidation stress, inflammation and apoptosis in ischemic parietal cortex of rats after middle cerebral artery occlusion and reperfusion (MCAO/R) injury. Moreover, the activated TLR4 and C5aR1 signaling pathways were inhibited by schisantherin A treatment. In conclusion, TLR4 and C5aR1 played a vital role during I/R brain injury in rats, and schisantherin A exhibited neuroprotective effects by TLR4 and C5aR1 signaling pathways. These findings also provided new insights that would aid in elucidating the effect of schisantherin A against cerebral I/R and support the development of schisantherin A as a potential treatment for ischemic stroke.


Assuntos
Isquemia Encefálica/metabolismo , Ciclo-Octanos/administração & dosagem , Dioxóis/administração & dosagem , Lignanas/administração & dosagem , Fármacos Neuroprotetores/administração & dosagem , Receptor da Anafilatoxina C5a/metabolismo , Traumatismo por Reperfusão/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Apoptose/efeitos dos fármacos , Isquemia Encefálica/complicações , Isquemia Encefálica/prevenção & controle , Sobrevivência Celular/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Inflamação/etiologia , Inflamação/metabolismo , Necrose/tratamento farmacológico , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Estresse Oxidativo , Lobo Parietal/efeitos dos fármacos , Lobo Parietal/metabolismo , Lobo Parietal/patologia , Cultura Primária de Células , Ratos Sprague-Dawley , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/prevenção & controle , Transdução de Sinais
6.
Sci Rep ; 7(1): 3651, 2017 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-28623330

RESUMO

Elevated ground-level ozone (O3), which is an important aspect of air quality related to public health, has been causing increasing concern. This study investigated the spatiotemporal distribution of ground-level O3 concentrations in China using a dataset from the Chinese national air quality monitoring network during 2013-2015. This research analyzed the diurnal, monthly and yearly variation of O3 concentrations in both sparsely and densely populated regions. In particular, 6 major Chinese cities were selected to allow a discussion of variations in O3 levels in detail, Beijing, Chengdu, Guangzhou, Lanzhou, Shanghai, and Urumchi, located on both sides of the Heihe-Tengchong line. Data showed that the nationwide 3-year MDA8 of ground-level O3 was 80.26 µg/m3. Ground-level O3 concentrations exhibited monthly variability peaking in summer and reaching the lowest levels in winter. The diurnal cycle reached a minimum in morning and peaked in the afternoon. Yearly average O3 MDA8 concentrations in Beijing, Chengdu, Lanzhou, and Shanghai in 2015 increased 12%, 25%, 34%, 22%, respectively, when compared with those in 2013. Compared with World Health Organization O3 guidelines, Beijing, Chengdu, Guangzhou, and Shanghai suffered O3 pollution in excess of the 8-hour O3 standard for more than 30% of the days in 2013 to 2015.

7.
Mol Neurobiol ; 54(3): 2126-2142, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-26924319

RESUMO

Ischemic stroke is a major disability and cause of death worldwide due to its narrow therapeutic time window. Neuroprotective agent is a promising strategy to salvage acutely ischemic brain tissue and extend the therapeutic time window for stroke treatment. In this study, we aimed to evaluate the neuroprotective effects of isoquercetin in (1) primary culture of rat hippocampal neurons exposure on oxygen and glucose deprivation and reperfusion (OGD/R) injury and (2) rats subjected to transient middle cerebral artery occlusion and reperfusion (MCAO/R) injury. The results showed that isoquercetin post-treatment reduced the infarct size, number of apoptotic cells, oxidative stress, and inflammatory response after ischemia and reperfusion injury. The underlying mechanism study indicated that the neuroprotective effects of isoquercetin were elicited via suppressing the activation of toll-like receptor 4 (TLR4), nuclear factor-kappa B (NF-κB) and caspase-1; the phosphorylation of ERK1/2, JNK1/2, and p38 mitogen-activated protein kinase (MAPK); and the secretion of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6. In addition, isoquercetin also effectively alleviated hippocampus neuron apoptosis by regulation of cyclic AMP responsive element-binding protein (CREB), Bax, Bcl-2, and caspase-3. Our report provided new considerations into the therapeutic action and the underlying mechanisms of isoquercetin to improve brain injury in individuals who have suffered from ischemic stroke. As a potent anti-inflammatory and anti-oxidative compound with neuroprotective capacities, the beneficial effects of isoquercetin when used to treat ischemic stroke and related diseases in humans warrant further studies.


Assuntos
Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Região CA1 Hipocampal/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Quercetina/análogos & derivados , Animais , Isquemia Encefálica/patologia , Região CA1 Hipocampal/citologia , Região CA1 Hipocampal/metabolismo , Células Cultivadas , Inflamação/tratamento farmacológico , Isquemia/tratamento farmacológico , Masculino , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Quercetina/farmacologia , Ratos Sprague-Dawley , Traumatismo por Reperfusão/patologia
8.
J. physiol. biochem ; 70(3): 735-747, sept. 2014.
Artigo em Inglês | IBECS | ID: ibc-127318

RESUMO

Brain ischemia appears to be associated with innate immunity. Recent reports showed that C3a and C5a, as potent targets, might protect against ischemia induced cell death. In traditional Chinese medicine, the fruit of Schizandra chinesis Baill (Fructus schizandrae) has been widely used as a tonic. In the present study, we sought to evaluate the neuroprotective effects of schizandrin A, a composition of S. chinesis Baill, against oxygen and glucose deprivation followed by reperfusion (OGD/R)-induced cell death in primary culture of rat cortical neurons, and to test whether C3a and C5a affected cortical neuron recovery from ischemic injury after schizandrin A treatment. The results showed that schizandrin A significantly reduced cell apoptosis and necrosis, increased cell survival, and decreased intracellular calcium concentration ([Ca2+]i) and lactate dehydrogenase (LDH) release in primary culture of rat cortical neurons after OGD/R. Mechanism studies suggested that the modulation of extracellular-regulated kinase (ERK), c-Jun NH2-terminal kinases (JNK), and p38, as well as caspase-3 activity played an important role on the progress of neuronal apoptosis. C5aR participated in the neuroprotective effect of schizandrin A in primary culture of rat cortical neurons after OGD/R. Our findings suggested that schizandrin A might act as a candidate therapeutic target drug used for brain ischemia and related diseases


Assuntos
Animais , Ratos , Fármacos Neuroprotetores/farmacocinética , Schisandraceae , Neurônios , Traumatismo por Reperfusão/prevenção & controle , Proteínas Quinases Ativadas por Mitógeno , Apoptose , Isquemia/tratamento farmacológico , Modelos Animais de Doenças , Substâncias Protetoras/farmacocinética , Extratos Vegetais/farmacocinética
9.
J Physiol Biochem ; 70(3): 735-47, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24986222

RESUMO

Brain ischemia appears to be associated with innate immunity. Recent reports showed that C3a and C5a, as potent targets, might protect against ischemia induced cell death. In traditional Chinese medicine, the fruit of Schizandra chinesis Baill (Fructus schizandrae) has been widely used as a tonic. In the present study, we sought to evaluate the neuroprotective effects of schizandrin A, a composition of S. chinesis Baill, against oxygen and glucose deprivation followed by reperfusion (OGD/R)-induced cell death in primary culture of rat cortical neurons, and to test whether C3a and C5a affected cortical neuron recovery from ischemic injury after schizandrin A treatment. The results showed that schizandrin A significantly reduced cell apoptosis and necrosis, increased cell survival, and decreased intracellular calcium concentration ([Ca(2+)]i) and lactate dehydrogenase (LDH) release in primary culture of rat cortical neurons after OGD/R. Mechanism studies suggested that the modulation of extracellular-regulated kinase (ERK), c-Jun NH2-terminal kinases (JNK), and p38, as well as caspase-3 activity played an important role on the progress of neuronal apoptosis. C5aR participated in the neuroprotective effect of schizandrin A in primary culture of rat cortical neurons after OGD/R. Our findings suggested that schizandrin A might act as a candidate therapeutic target drug used for brain ischemia and related diseases.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Ciclo-Octanos/farmacologia , Lignanas/farmacologia , Fármacos Neuroprotetores/farmacologia , Compostos Policíclicos/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Cálcio/metabolismo , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Glucose/metabolismo , L-Lactato Desidrogenase/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Medicina Tradicional Chinesa , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Fitoterapia , Ratos , Receptor da Anafilatoxina C5a/genética , Receptor da Anafilatoxina C5a/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Schisandra , Transdução de Sinais/efeitos dos fármacos
10.
J Neurosci Res ; 92(7): 944-54, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24687774

RESUMO

Mulberroside A is a natural polyhydroxylated stilbene compound present at relatively high abundance in the roots and twigs of Morus alba L. It is known for its nephroprotective, hypoglycemic, and antidiabetic effects. Because its metabolite, oxyresveratrol, possessed purported anti-inflammatory and neuroprotective effects, we proposed that mulberroside A may elicit neuroprotective effects that can be used in the treatment of brain ischemic injury. Therefore, we decided to investigate the pharmacological properties of mulberroside A in primary culture of rat cortical neurons after oxygen-glucose deprivation followed by reperfusion (OGD/R), evaluating its ability to counteract the hypoxia-ischemia impairment. The results showed that mulberroside A elicited neuroprotective effects comparable to nimodipine. The mechanistic studies showed that mulberroside A decreased the expressions of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, and IL-6 and inhibited the activation of NALP3, caspase-1, and nuclear factor-κB and the phosphorylation of extracellular signal-regulated protein kinases, the c-Jun N-terminal kinase, and p38, exhibiting anti-inflammatory antiapoptotic effects. Our results also further demonstrate that the proinflammatory cytokines of IL-1ß, IL-6, and TNF-α are promising targets for treatment of cerebral ischemic injury. Although further investigation is required for its development, all of these findings led us to speculate that mulberroside A is a candidate for the treatment of ischemic stroke, which would act as a multifactorial neuroprotectant.


Assuntos
Córtex Cerebral/citologia , Dissacarídeos/farmacologia , Glucose/deficiência , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Estilbenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Proteínas de Transporte , Caspase 1/metabolismo , Hipóxia Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocinas/genética , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Embrião de Mamíferos , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Ratos , Ratos Sprague-Dawley , Receptores Citoplasmáticos e Nucleares/metabolismo , Transdução de Sinais/efeitos dos fármacos
11.
Neurochem Int ; 63(8): 741-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24099731

RESUMO

In the present study, oxygen-glucose deprivation followed by reperfusion (OGD/R), an in vitro model of ischemia, was used to evaluate the neuroprotective effect of isoquercetin in primary culture of rat cortical neuronal cells. It was found that isoquercetin administered prior to the insult could prevent OGD/R-induced intracellular calcium concentrations ([Ca(2+)]i) increase, lactate dehydrogenase (LDH) release and cell viability decrease. For the first time, isoquercetin is described as a neuroprotective agent that potentially explains the alleviation and prevention from OGD/R-induced injury in neurons. Mechanistic studies showed that the neuroprotective effect of isoquercetin was carried out by anti-inflammatory signaling pathway of inhibiting protein expression of toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB), and mRNA expression of TNF-α and IL-6, accompanied by the anti-apoptotic signaling pathway of deactivation of extracellular-regulated kinase (ERK), Jun kinase (JNK) and p38, and inhibition of activity of caspase-3. Therefore, these studies highlighted the confirmation of isoquercetin, a flavonoid compound, as an anti-inflammation and anti-apoptosis factor which might be used as a therapeutic strategy for the ischemia/reperfusion (I/R) brain injury and related diseases.


Assuntos
Córtex Cerebral/efeitos dos fármacos , Glucose/metabolismo , Neurônios/efeitos dos fármacos , Oxigênio/metabolismo , Quercetina/farmacologia , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismo , Animais , Sequência de Bases , Células Cultivadas , Córtex Cerebral/citologia , Córtex Cerebral/metabolismo , Primers do DNA , NF-kappa B/metabolismo , Neurônios/metabolismo , Quercetina/química , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
Ying Yong Sheng Tai Xue Bao ; 23(10): 2670-6, 2012 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-23359925

RESUMO

A laboratory experiment with the soil samples collected from China and Canada was conducted to study the effects of land use type (forestland vs. grassland) and incubation temperature (10 degrees C vs. 15 degrees C) on the soil nitrification, nitrogen mineralization, and N2O and CO2 emissions under aerobic condition. As compared with forestland soils, grassland soils had higher nitrification rate and N2O emission, with the highest nitrification rate in China grassland soil. At 10 and 15 degrees C, the average net nitrification rate of China grassland soil was 2.10 and 2.86 mg N x kg(-1) x d(-1) and the cumulative N2O emission in 15 incubation days was 10.2 and 15.4 microg N2O-N x kg(-1), respectively. Soil pH was the main factor affecting the nitrification rate and N2O emission, and there existed significant positive correlations between the soil pH and the nitrification rate and N2O emission. Forestland soils had higher nitrogen mineralization rate and CO2 emission than grassland soils, and China forestland soil had the highest nitrogen mineralization rate, with the average net mineralization rate at 10 and 15 degrees C being 3.08 and 2.87 mg N x kg(-1) x d(-1), respectively. The CO2 emission was the highest in Canada forestland soil, and the cumulative CO2 emission in 15 incubation days at 10 and 15 degrees C was 314 and 370 mg CO2-C x kg(-1), respectively. The soil organic carbon and soluble organic carbon contents had significant positive correlations with the soil nitrogen mineralization rate and CO2 emission, respectively, whereas the increasing soil temperature promoted the nitrification in grassland soils and the N2O emission from forestland soils and grassland soils. The same pronounced effects of increasing temperature were also found on the CO2 emission from forestland soils.


Assuntos
Dióxido de Carbono/análise , Nitrogênio/química , Óxido Nitroso/análise , Solo/química , Monitoramento Ambiental , Efeito Estufa , Nitrificação , Nitrogênio/análise , Poaceae/crescimento & desenvolvimento , Temperatura , Árvores/crescimento & desenvolvimento
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