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Quantifying in situ N2 fluxes from an intensively managed calcareous soil using the 15N gas-flux method

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Journal of Integrative Agriculture 2022年第9期21卷 2750-2766页

作者： liu Yan WANG rui pan Zhan-lei ZHENG Xun-hua WEI huan-huan ZHANG hong-rui MEI Bao-ling QUAN Zhi FANG Yun-ting JU xiao-tang State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of Sciences(CAS)Beijing 100029P.R.China College of Earth and Planet Science University of Chinese Academy of SciencesBeijing 100049P.R.China College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193P.R.China School of Ecology and Environment Inner Mongolia UniversityHohhot 010021P.R.China CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110164P.R.China College of Tropical Crops Hainan UniversityHaikou 570228P.R.China

Denitrification-induced nitrogen(N) losses from croplands may be greatly increased by intensive ***,the accurate quantification of these losses is still challenging due to insufficient available in situ measurements of soil dinitrogen(N) *** carried out two one-week experiments in a maize-wheat cropping system with calcareous soil using theN gas-flux(NGF) method to measure in situ Nfluxes following urea *** ofN-labeled urea(99 atom%,130-150 kg N ha) were followed by irrigation on the 1 st,3 rd,and 5 th days after fertilization(DAF 1,3,and 5,respectively).The detection limits of the soil Nfluxes were 163-1 565,81-485,and 54-281 μg N mhfor the two-,four-,and six-hour static chamber enclosures,*** Nfluxes measured in 120 cases varied between 159 and 2 943(811 on average) μg N *** were higher than the detection limits,with the exception of only two *** Nfluxes at DAF 3 were significantly higher(by nearly 80%(P<0.01)) than those at DAF 1 and 5 in the maize experiment,while there were no significant differences among the irrigation times in the wheat *** Nfluxes and the ratios of nitrous oxide(NO) to the NO plus Nfluxes following urea application to maize were approximately 65% and 11 times larger,respectively(P<0.01),than those following urea application to *** differences could be mainly attributed to the higher soil water contents,temperatures,and availability of soil N substrates in the maize experiment than in the wheat *** study suggests that theNGF method is sensitive enough to measure in situ Nfluxes from intensively fertilized croplands with calcareous soils.

关键词： N2 fluxes 15N gas-flux method N2O/(N2O+N2)ratios detection limit intensive cropping system

Possible Involvement of K^＋/Na^＋ in Assessing the Seed Vigor Index

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Journal of Integrative Plant Biology 2005年第8期47卷 935-941页

作者： hong-Yan CHENG Guang-hua ZHENG xiao-Feng WANG Yan liu Yi-tang YAN jian LIN Institute of Botany the Chinese Academy of Sciences Beijing 100093 China Department of Biology Beijing Forestry University Beijing 100083 China

More substances leaked from a higher-vigor seed sample than from a lower-vigor sample. This indicates that, in some cases, electric conductivity does not represent seed vigor level very well, especially for high-vigor seeds. Results from germination, germination index, leachate conductivity, and the ratio of K^＋/Na^＋ from three-seed lots of Chinese cabbage （Brassica pekinensis （Louv.） Rupr） showed that K^＋/Na^＋ correlated well with germination and germination index. The ability of K^＋/Na^＋ to indicate well changes in vigor was further supported by investigation in soybean （Glycine max （L.） Merr.） seeds and another cultivar of Chinese cabbage seeds. Thus, seed leakage of K^＋/Na^＋ can accurately indicate seed vigor, whereas the conductivity test failed to do so. Furthermore, K^＋/Na^＋ showed up bigger quantitative differences in vigor level than did the conductivity test. This findings provide a more sensitive and accurate index for the assessment of seed vigor. The mechanisms of Na^＋ and K^＋ ion transport are also discussed.

关键词： Chinese cabbage K^+/Na^+ leakage seed vigor soybean.

Strengthening Mechanism and Microstructure of Deformable Ti Particles Reinforced AZ91 Composite

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Acta Metallurgica Sinica(English Letters) 2022年第12期35卷 1935-1945页

作者： Biao tang jian-Bo Li Jun-liu Ye huan Luo Yi-Tao Wang Bo Guan Yang-Fan Lu xian-hua Chen Kai-hong Zheng Fu-Sheng pan School of Materials Science and Engineering Chongqing UniversityChongqing 400044China International Joint Laboratory for Light Alloys(MOE) School of Materials Science and EngineeringChongqing UniversityChongqing 400044China Institute of New Materials Guangdong Academy of SciencesGuangzhou 510650China

In this study,the deformable titanium(Ti)particles reinforced AZ91 composite was successfully prepared by powder metallurgy and subsequent *** mechanical properties and microstructural evolution of pure AZ91 and 5 Ti/AZ91 composite were *** yield strength,ultimate tensile strength,and elongation of 5 Ti/AZ91 composite are measured to be 212 MPa,323 MPa,and 10.1%,*** analysis revealed that Ti particles are elongated along the extrusion direction,forming a discontinuous strip Ti particles,fine precipitated Mg_(17)Al_(12) phase inhibits dynamic recrystallization(DRX)behavior through Zener pinning effect and hinders the growth of matrix grains,resulting in refiner grains of 5 Ti/AZ91 *** deformed Ti particles and magnesium(Mg)matrix to generate additional heterogeneous deformation-induced(HDI)*** deformation-induced strengthening mainly contributed to the increment of yield strength for 5 Ti/AZ91 composite.

关键词： Magnesium matrix composites Tiparticles Recrystallization Mechanical properties Heterogeneous deformation

Pro-inflammatory microenvironment and systemic accumulation of CXCR3+cell exacerbate lung pathology of old rhesus macaques infected with SARS-CoV-2

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Signal Transduction and Targeted Therapy 2021年第10期6卷 3033-3044页

作者： hong-Yi Zheng xiao-Yan He Wei Li Tian-Zhang Song jian-Bao Han xiang Yang Feng-Liang liu Rong-hua Luo Ren-Rong Tian xiao-Li Feng Yu-hua Ma Chao liu Ming-hua Li Yong-tang Zheng Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common DiseasesKunming Institute of ZoologyChinese Academy of SciencesKunmingYunnanChina Kunming College of Life Science University of Chinese Academy of SciencesKunmingYunnanChina Kunming National High-Level Biosafety Research Center for Non-Human Primates Center for Biosafety Mega-ScienceKunming Institute of ZoologyChinese Academy of SciencesKunmingYunnanChina National Resource Center for Non-Human Primates National Research Facility for Phenotypic&Genetic Analysis of Model Animals(Primate Facility)Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnanChina Bioland Laboratory(Guangzhou Regenerative Medicine and Health Guangdong Laboratory) GuangzhouChina

Understanding the pathological features of severe acute respiratory syn drome coronavirus 2(SARS-CoV-2)infect io n in an animal model is crucial for the treatment of coronavirus disease 2019(COVID-19).Here,we compared imnnunopathological changes in young and old rhesus macaques(RMs)before and after SARS-CoV-2 infection at the tissue *** analysis of multiplex immunofluoresce nee staining images of formali n-fixed paraffi n-embedded(FFPE)sections showed that SARS-CoV-2 infectio n specifically induced elevated levels of apoptosis,autophagy,and nuclear factor kappa-B(NF-kB)activation of angiotensirv convert!ng enzyme 2(ACE2)+cells,and increased interferon a(IFN-a)-and interleukin 6(IL-6)-secreting cells and C-X-C motif chemokine receptor 3(CXCR3)+cells in lung tissue of old *** pathological pattern,which may be related to the age-related pro-inflammatory microenvironment in both lungs and spleens,was significantly correlated with the systemic accumulation of CXCR3+cells in lungs,spleens,and peripheral ***,the ratio of CXCR3+to T-box protein expression in T cell(T-bet)+(CXCR3+/T-bet+ratio)in CD8+cells may be used as a predictor of severe *** findings uncovered the impact of aging on the immunopathology of early SARS-CoV-2 infection and demonstrated the potential application of CXCR3+cells in predicting severe COVID-19.

关键词： CXCR3 spleen lung

Delayed severe cytokine storm and immune cell infiltration in SARS-CoV-2-infected aged Chinese rhesus macaques

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Zoological Research 2020年第5期41卷 503-516页

作者： Tian-Zhang Song hong-Yi Zheng jian-Bao Han Lin Jin xiang Yang Feng-Liang liu Rong-hua Luo Ren-Rong Tian Hou-Rong Cai xiao-Li Feng Chao liu Ming-hua Li Yong-tang Zheng Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common DiseasesKunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650223China Kunming National High-Level Biosafety Research Center for Non-Human Primates Center for Biosafety Mega-ScienceKunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650107China Department of Respiratory and Critical Care Medicine Affiliated Drum Tower Hospital of Nanjing UniversityNanjingJiangsu 210008China National Resource Center for Non-Human Primates National Research Facility for Phenotypic&Genetic Analysis of Model Animals(Primate Facility)Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650107China

As of June 2020, Coronavirus Disease 2019(COVID-19) has killed an estimated 440 000 people worldwide, 74% of whom were aged ≥65 years,making age the most significant risk factor for death caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection. To examine the effect of age on death, we established a SARSCoV-2 infection model in Chinese rhesus macaques(Macaca mulatta) of varied ages. Results indicated that infected young macaques manifested impaired respiratory function, active viral replication, severe lung damage, and infiltration of CD11b^+ and CD8^+ cells in lungs at one-week post infection(wpi), but also recovered rapidly at 2 wpi. In contrast, aged macaques demonstrated delayed immune responses with a more severe cytokine storm, increased infiltration of CD11b^+ cells, and persistent infiltration of CD8^+ cells in the lungs at 2 wpi. In addition,peripheral blood T cells from aged macaques showed greater inflammation and chemotaxis, but weaker antiviral functions than that in cells from young macaques. Thus, the delayed but more severe cytokine storm and higher immune cell infiltration may explain the poorer prognosis of older aged patients suffering SARS-CoV-2 infection.

关键词： COVID-19 Non-human primate animal model Elderly Immune response

Enhancement of CTLs induced by DCs loaded with ubiquitinated hepatitis B virus core antigen

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World Journal of Gastroenterology 2012年第12期18卷 1319-1327页

作者： jian-hua Chen Yong-Sheng Yu xiao-hua Chen hong-hong liu Guo-Qing Zang Zheng-Hao tang Department of Infec-tious Diseases Sixth People's Hospital Affiliated to ShanghaiJiaotong UniversityShanghai 200233China

AIM： To investigate whether hepatitis B virus （HBV） could induce a hepatitis B virus core antigen （HBcAg）specific cytotoxic T lymphocyte （CTL） response in vitro by dendritic cells （DCs） transduced with lentiviral vector-encoding ubiquitinated hepatitis B virus core antigen （LV-Ub-HBcAg）.METHODS： Recombinant LV-Ub-HBcAg were transfected into highly susceptible 293 T cells to obtain high virus titres, Bone marrow-derived DCs isolated from BALB/c mice were cultured with recombinant granulocyte-macrophage colony-stimulating factor and recombinant interleukin （IL）-4. LV-Ub-HBcAg, lentiviral vector-encoding hepatitis B virus core antigen （LV-HBcAg）, lentiviral vector （LV） or lipopolysaccharide were added to induce DC maturation, and the DC phenotypes were analyzed by flow cytometry. The level of IL-12 in the supernatant was detected by enzyme-linked immunosorbent assay （ELISA）. T lymphocytes were proliferated using Cell Counting Kit-8. DCs were cultured and induced to mature using different LVs, and co-cultured with allogeneic T cells to detect the secretion levels of IL-2, IL-4, IL-10and interferon-γ in the supernatants of T cells by ELISA. Intracellular cytokines of proliferative T cells were analyzed by flow cytometry, and specific CTL activity was measured by a lactate dehydrogenase release assay.RESULTS： LV-Ub-HBcAg-induced DCs secreted more IL-12 and upregulated the expression of CD80, CD86 and major histocompatibility class ]I, DCs sensitised by different LVs effectively promoted cytokine secretion; the levels of IL-2 and interferon-y induced by LV-Ub- HBcAg were higher than those induced by LV-HBcAg, Compared with LV-HBcAg-transduced DCs, LV-Ub- HBcAg-transduced DCs more efficiently stimulated the proliferation of T lymphocytes and generated HBcAgspecific cytotoxic T lymphocytes.CONCLUSION： LV-Ub-HBcAg effectively induced DC maturation. The mature DCs efficiently induced T cell polarisation to Thl and generated HBcAg-specific CTLs.

关键词： Ubiquitin Hepatitis B virus core antigen Lentiviruses Dendritic cells Cytotoxic T lymphocytes

Induction of apoptosis of human gastric carcinoma SGC-7901 cell line by 5,7-dihydroxy-8-nitrochrysin in vitro

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World Journal of Gastroenterology 2007年第28期13卷 3824-3828页

作者： xiao-hong Ai Xing Zheng xiao-Qing tang Li Sun Yang-Qin Zhang Yong Qin hua-Qing liu hong xia jian-Guo Cao Department of Oncology First Affiliated Hospital Nahua University Hengyang 421001 Hunan Province China Institute of Oncology Nahua University Hengyang 421001 Hunan Province China Institute of Pharmacology Nahua University Hengyang 421001 Hunan Province China School of Pharmaceutical Science Central South University Changsha 410078 Hunan Province China

AIM： To investigate the effect of 5, 7-dihydroxy-8- nitrochrysin （NOChR） on apoptosis of human gastric carcinoma SGC-7901 cell line.METHODS： SGC-7901 cells were cultured in vitro and the inhibitory effect of NOChR on proliferation of SGC-7901 cells was measured by using an Ml-r assay. NOChR-induced apoptosis rate of SGC-7901 cells was detected using flow cytometry （FCM） with PI staining. DNA ladder bands were observed by DNA agarose gel electrophoresis. The influence of NOChR on the proxisome proliferator-activated receptor-γ （PPARγ）, Bcl-2 and Bax protein expression of SGC-7901 cells was analyzed by Western blot.RESULTS： MIF assay showed that NOChR markedly inhibited proliferation of SGC-7901 cells in a dose- dependent manner, and when ICso was 4.14 μmol/L, the potency of NOChR was 10 times than that of lead compound, chrysin （ChR, IC50 was 40.56 μmol/L）, and was similar to 5-fluorouracil （5-FU, IC50 was 4.51 μmol/L）. FCM with propidium iodide （PI） staining demonstrated that the apoptosis rates of SGC-7901 cells treated with 1.25, 5.00 and 20.00 μmol/L NOChR for 48 h were 9.8% 4- 0.2%, 36.8% 4- 1.9% and 45.5% 4- 3.5%, respectively, and were significantly higher when treated with 5.00 and 20.00 μmol/L NOChR than that with 20.00 μmol/L ChR （12.9% 4- 1.5%）. DNA agarose gel electrophoresis showed that treatment of SGC-7901 cells with 20.00 μmol/L NOChR for 48 h resulted in typical DNA ladder bands of DNA of SGC-7901 cells, which could be eliminated by treating with 10.00 μmol/L GW9662, a blocker of PPARy. Western blot analysis revealed that after 24 h of treatment with 20.00 μmol/L NOChR, PPARgamma and Bax protein expression of SGC-7901 cells increased but Bcl-2 expression decreased; however, pre-incubation with 10.00 μmol/L GW9662 could efficiently antagonize and weaken the regulatory effect of 20.00 μmol/L NOChR on Bax and Bcl-2 protein expression of SGC-7901 cells. CONCLUSION： NOChR induces apoptosis of SGO7901 cell lines by activating PPARy and decreasing rat

关键词： Gastric neoplasm Chrysin Chrysin derivatives Apoptosis Proxisome proliferator-activated receptorγ Bcl-2 Bax

Rosiglitazone enhances fluorouracil-induced apoptosis of HT-29 cells by activating peroxisome proliferator-activated receptor γ

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World Journal of Gastroenterology 2007年第10期13卷 1534-1540页

作者： Yan-Qin Zhang xiao-Qing tang Li Sun Lin Dong Yong Qin hua-Qing liu hong xia jian-Guo Cao Cancer-Research institute of N-anhua University Hengyang 421001 Hunan Province China Department of Pharmacology School of Pharmaceutical Sciences Central South University Changsha 410078 Hunan Province China

AIM： To examine whether and how rosiglitazone enhances apoptosis induced by fluorouracil in human colon cancer （HT-29） cells. METHODS： Human colon cancer HT-29 cells were cultured in vitro and treated with fluorouracil and/or rosiglitazone. Proliferation and growth of HT-29 cells were evaluated by MTF assay and trypan blue exclusion methods, respectively. The apoptosis of HT-29 cells was determined by acridine orange/ethidium bromide staining and flow cytometry using PI fluorescence staining. The expressions of peroxisome proliferator-activated receptor γ （PPARγ）, Bcl-2 and Bax in HT-29 cells were analyzed by Western blot. RESULTS： Although rosiglitazone at the concentration below 30 μmol/L for 72 h exerted almost no inhibitory effect on proliferation and growth of HT-29 cells, it could significantly enhance fluorouracil-induced HT-29 cell proliferation and growth inhibition. Furthermore, 10 μmol/L rosilitazone did not induce apoptosis of HT-29 cells but dramatically enhanced fluorouracil-induced apoptosis of HT-29 cells. However, rosiglitazone did not improve apoptosis induced by fluorouracil in HT-29 cells pretreated with GW9662, a PPARγ antagonist. Meanwhile, the expression of Bax and PPAR7 was upregulated, while the expression of Bcl-2 was down regulated in HT-29 cells treated with rosiglitazone in a time-dependent manner. However, the effect of rosiglitazone on Bcl-2 and Bax was blocked or diminished in the presence of GW9662. CONCLUSION： Rosiglitazone enhances fluorouracilinduced apoptosis of HT-29 cells by activating PPARγ.

关键词： Colon cancer Rosiglitazone Fluorouracil Apoptosis

Lower respiratory tract samples are reliable for severe acute respiratory syndrome coronavirus 2 nucleic acid diagnosis and animal model study

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Zoological Research 2021年第2期42卷 161-169页

作者： Ren-Rong Tian Cui-xian Yang Mi Zhang xiao-Li Feng Rong-hua Luo Zi-Lei Duan jian-jian Li Jia-Fa liu Dan-Dan Yu Ling Xu hong-Yi Zheng Ming-hua Li hong-Li Fan Jia-Li Wang Xing-Qi Dong Yong-tang Zheng Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common DiseasesKunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650223China Center for Biosafety Mega-Science Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650223China Yunnan Infectious Diseases Hospital KunmingYunnan 650301China

Severe acute respiratory syndrome coronavirus 2(SARS-Co V-2) and coronavirus disease 2019(COVID-19) continue to impact countries *** present, inadequate diagnosis and unreliable evaluation systems hinder the implementation and development of effective prevention and treatment strategies. Here, we conducted a horizontal and longitudinal study comparing the detection rates of SARS-Co V-2 nucleic acid in different types of samples collected from COVID-19 patients and SARS-Co V-2-infected monkeys. We also detected anti-SARS-Co V-2 antibodies in the above clinical and animal model samples to identify a reliable approach for the accurate diagnosis of SARS-Co V-2 infection. Results showed that, regardless of clinical symptoms, the highest detection levels of viral nucleic acid were found in sputum and tracheal brush samples, resulting in a high and stable diagnosis rate. Anti-SARS-Co V-2 immunoglobulin M(Ig M) and G(Ig G) antibodies were not detected in6.90% of COVID-19 patients. Furthermore,integration of nucleic acid detection results from the various sample types did not improve the diagnosis rate. Moreover, dynamic changes in SARS-Co V-2 viral load were more obvious in sputum and tracheal brushes than in nasal and throat swabs. Thus,SARS-Co V-2 nucleic acid detection in sputum and tracheal brushes was the least affected by infection route, disease progression, and individual differences. Therefore, SARS-Co V-2 nucleic acid detection using lower respiratory tract samples alone is reliable for COVID-19 diagnosis and study.

关键词： COVID-19 SARS-CoV-2 Diagnosis Animal model