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1.
Nat Commun ; 15(1): 2155, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38461160

RESUMO

The summer Eurasian westerly jet is reported to become weaker and wavier, thus promoting the frequent weather extremes. However, the primary driver of the changing jet stream remains in debate, mainly due to the regionality and seasonality of the Eurasian jet. Here we report a sharp increase, by approximately 140%, in the interannual variability of the summertime East Asian jet (EAJ) since the end of twentieth century. Such interdecadal change induces considerable changes in the large-scale circulation pattern across Eurasia, and consequently weather and climate extremes including heatwaves, droughts, and Asian monsoonal rainfall regime shifts. The trigger mainly emerges from preceding February North Atlantic seesaw called Scandinavian pattern (contributing to 81.1 ± 2.9% of the enhanced EAJ variability), which harnesses the "cross-seasonal-coupled oceanic-atmospheric bridge" to exert a delayed impact on EAJ and thus aids relevant predictions five months in advance. However, projections from state-of-the-art models with prescribed anthropogenic forcing exhibit no similar circulation changes. This sheds light on that, at the interannual timescale, a substantial portion of recently increasing variability in the East Asian sector of the Eurasian westerly jet arises from unforced natural variability.

2.
Food Res Int ; 176: 113842, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38163733

RESUMO

Oil autoxidation is an early process of food deterioration, monitoring oil oxidation is therefore of great significance to ensure food quality and safety. In this study, a detection method of the primary and secondary oxidative products was developed by gas chromatography ion mobility spectrometry (GC-IMS).The secondary oxidative products was analyzed by GC-IMS. Then, the relationships between peroxide values and the contents of secondary oxidative products were investigated by constructing a prediction model of peroxide value of rapeseed oil with the help of secondary oxidative products and chemometrics. The coefficient of determination Q2 of the model validation set is 0.96, and the RMSECV is 0.1570 g/100 g. These validation results indicated that secondary oxidative products could also reflect the content of the primary oxidative products. Moreover, 10 characteristic markers related to oxidative rancidity were identified for monitoring edible oil rancidity and oxidative stability.


Assuntos
Qualidade dos Alimentos , Espectrometria de Mobilidade Iônica , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Mobilidade Iônica/métodos , Óleo de Brassica napus , Peróxidos
3.
Clin Rev Allergy Immunol ; 64(1): 17-32, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35031959

RESUMO

The current COVID-19 global pandemic poses immense challenges to global health, largely due to the difficulty to detect infection in the early stages of the disease, as well as the current lack of effective antiviral therapy. Research and understanding of the human immune system can provide important theoretical and technical support for the clinical diagnosis and treatment of COVID-19, the clinical implementations of which include immunoassays and immunotherapy, which play a crucial role in the fight against the pandemic. This review consolidates the current scientific evidence for immunoassay, which includes multiple methods of detecting antigen and antibody against SARS-CoV-2. We compared the characteristics, advantages and disadvantages, and clinical applications of these three detection techniques. In addition to detecting viral infections, knowledge on the body's immunity against the virus is desirable; thus, the immunotherapy-based neutralizing antibody (nAb) detection methods were discussed. We also gave a brief introduction to the new immunoassay technology such as biosensing. This was followed by an in-depth and extensive review on a variety of immunotherapy methods. It includes convalescent plasma therapy, neutralizing antibody-based treatments targeting different regions of SARS-CoV-2, immunotherapy targeted on the host cell including inhibiting the host cell receptor and cytokine storm, as well as cocktail antibodies, cross-neutralizing antibodies, and immunotherapy based on cross-reactivity between viral epitopes and autoepitopes and autoantibody. Despite the development of various immunological testing methods and antibody therapies, the current global situation of COVID-19 is still tense. We need more efficient detection methods and more reliable antibody therapies. The up-to-date knowledge on therapeutic strategies will likely help clinicians worldwide to protect patients from life-threatening viral infections.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Anticorpos Antivirais , Soroterapia para COVID-19 , Anticorpos Neutralizantes/uso terapêutico , Imunoterapia/métodos , Imunoensaio
4.
Natl Sci Rev ; 7(7): 1150-1153, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34692139

RESUMO

The Maritime Continent is a huge heat source region over the Indo-Pacific warm pool and it plays a key role in global weather/climate variations. The locations of Maritime Continent autumn droughts, linked to frequent rampant forest wildfires, are closely related to the mixed diversity of El Niño and Indian Ocean Dipole events.

5.
Arch Pharm (Weinheim) ; 350(2)2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28092111

RESUMO

A series of 5-substituted benzo[d][1,3]dioxole derivatives was designed, synthesized, and tested for anticonvulsant activity using the maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) screens. Neurotoxicity was determined by rotarod test. In the preliminary screening, six compounds, 3a, 3c, 3d, and 4d-f, showed promising anticonvulsant activities in the MES model, and compounds 4c and 4d exhibited full protection against seizures at doses of 300 mg/kg in the scPTZ model. Among the synthesized compounds, 3c as the most active compound showed high protection against the MES-induced seizures with an ED50 value of 9.8 mg/kg and a TD50 value of 229.4 mg/kg after intraperitoneal injection into mice, thus providing compound 3c with a high protective index (TD50 /ED50 ) of 23.4 comparable to those of reference antiepileptic drugs.


Assuntos
Anticonvulsivantes/síntese química , Anticonvulsivantes/farmacologia , Dioxóis/química , Dioxóis/farmacologia , Convulsões/prevenção & controle , Animais , Anticonvulsivantes/química , Dioxóis/síntese química , Relação Dose-Resposta a Droga , Desenho de Fármacos , Eletrochoque , Camundongos , Pentilenotetrazol , Teste de Desempenho do Rota-Rod , Convulsões/induzido quimicamente , Relação Estrutura-Atividade
6.
Sci Rep ; 6: 30470, 2016 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-27461985

RESUMO

Springtime rainfall, accounting for 25-40% of the annual rainfall in southern China, exerts great agricultural and socioeconomic impacts on the region. In the recent decades, southern China has experienced a significant declining trend of precipitation in boreal spring. Meanwhile, precipitation has increased over the South China Sea and the Philippine Sea (SCS-PhS). This paper presents observational and modeling evidences suggesting that the intensified latent heating released by the convection over SCS-PhS leads to suppressed springtime rainfall over southern China. Moisture budget analysis indicates that the drying trend over southern China is due mainly to weakened convergence of moisture flux, which is controlled by a heat-induced anomalous overturning circulation reinforced by the convection over SCS-PhS. Further idealized simulations support the feature that the heat-induced overturning circulation and its corresponding anomalous cyclone can be well established in several days under the spring mean flow condition. Thus, this rapid dynamic process is associated with both the intraseasonal-to-interannual variations and the long-term change of the springtime rainfall over southern China.

7.
Nat Commun ; 7: 11721, 2016 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-27251873

RESUMO

Arctic climate changes include not only changes in trends and mean states but also strong interannual variations in various fields. Although it is known that tropical-extratropical teleconnection is sensitive to changes in flavours of El Niño, whether Arctic climate variability is linked to El Niño, in particular on interannual timescale, remains unclear. Here we demonstrate for the first time a long-range linkage between central Pacific (CP) El Niño and summer Arctic climate. Observations show that the CP warming related to CP El Niño events deepens the tropospheric Arctic polar vortex and strengthens the circumpolar westerly wind, thereby contributing to inhibiting summer Arctic warming and sea-ice melting. Atmospheric model experiments can generally capture the observed responses of Arctic circulation and robust surface cooling to CP El Niño forcing. We suggest that identification of the equator-Arctic teleconnection, via the 'atmospheric bridge', can potentially contribute to improving the skill of predicting Arctic climate.

8.
Molecules ; 15(5): 3683-93, 2010 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-20657507

RESUMO

The essential oils of the Osmanthus fragrans tea (OFT), Osmanthus fragrans (OF) and green tea (GT) had been extracted by steam distillation and analyzed by gas chromatography-mass spectrometry (GC-MS) with the help of heuristic evolving latent projections (HELP), an effective chemometric resolution method (CRM). The overlapping peak clusters were resolved into pure chromatograms and pure mass spectra with HELP. The qualitative analysis was performed by similarity searches in the National Institute of Standards and Technology (NIST) mass spectra database with the obtained pure mass spectrum of each component. Identification of some compounds was also assisted by comparison of temperature-programmed retention indices (PTRI) with authentic standards included in our own laboratory database under construction. The quantitative results were obtained by overall volume integration (OVI) method. A total of 67, 73 and 53 components in essential oils of the OFT, OF and GT were identified, accounting for 90.83%, 93.65% and 89.97% total contents of the essential oil of OFT, OF and GT, respectively.


Assuntos
Óleos Voláteis/análise , Chá/química , Cromatografia Gasosa-Espectrometria de Massas , Métodos
9.
J Sep Sci ; 32(2): 258-66, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19156645

RESUMO

Comparative analysis of volatile constituents between recipe jingfangsan and its single herbs was performed by GC-MS combined with alternative moving window factor analysis (AMWFA), a new chemometric resolution method. Identification of the compounds was also assisted by comparison of temperature-programmed retention indices (PTRIs) on the OV-1 column with authentic samples. In total, 36, 29, and 42 volatile components in essential oil of Herba schizonepetae (HS), Radix saposhnikoviae (RS), and the recipe were respectively determined qualitatively and quantitatively, accounting for 81.80, 82.62 and 85.98% total contents of volatile oil of HS, RS, and the recipe respectively. Analysis by the method of AMWFA indicates that there are 22 common volatile constituents between the recipe and single herbal medicine HS, and 14 common volatile constituents between the recipe and single herb medicine RS. The experimental results also show that the volatile components of the recipe in number are almost addition of that of two single herbal medicines HS and RS, and are mainly from the single herbal medicine HS.


Assuntos
Medicamentos de Ervas Chinesas/análise , Medicamentos de Ervas Chinesas/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Óleos Voláteis/análise , Óleos Voláteis/química , Soluções
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