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50篇 您的检索式:作者名="Mingfeng Liu"
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1Temperature variation of a thermionic cathode during electron emission显示文摘It is necessary to know the actual temperature of a thermionic cathode that works as the electron source in a microwave tube. It has been found that the temperature of the cathode drops markedly during the thermionic emission. For example, the temperature could fall by about 30oC under a current density of 2.92 A/cm2. Using the molecular thermodynamics, the dependence of the cathode temperature on the emission current density has been obtained. It has been theoretically pointed out that several factors, such as heating model and temperature coefficient of resis-tance of heater, can influence the cathode temperature. These theoretical conclu-sions were supported by the experimental results.LIU YanWen TIAN Hong HAN Yong XU ZhenYing MENG MingFeng ZHANG HongLai 2008Science China(Technological Sciences)2008,51,9:22
2Investigation on the catalytic effects of AAEM during steam gasification and the resultant char reactivity in oxygen using Shengli lignite at different forms显示文摘Jianxin Mi Ningbo Wang Mingfeng Wang Pengju Huo Dan Liu 2015International Journal of Coal Science & Technology2015,2,3:14
3Daily variation characteristics of CO2 emission fluxes and contributions of environmental factors in semiarid grassland of Inner Mongolia, China显示文摘Fixed field experimental studies are carried out on daily variations of the undis- turbed community and soil respiration fluxes in different phenological phases of 2001―2002 in semiarid Aneurolepidium chinense steppe of Inner Mongolia, China using static black chamber method. Corresponding statistical analysis of the contributions of the water-heat factors (air temperature, ground temperature, surface soil water content) and ecological factors (above- ground biomass, underground biomass, litter biomass) to daily variation law of the undisturbed community and soil respiration fluxes as well as differences in daily respiration are also con- ducted. The results indicate that undisturbed community and soil respiration have apparent daily variation laws, daily variation patterns of respiration fluxes during different phenological phases are basically the same, and the variations of environmental factors only exert effect on CO2 emission intensities, while the effect on daily variation pattern of grassland CO2 emission fluxes is relatively small. The daily total respiration of the undisturbed community in different phenological phases ranges from 1.34―10.13 g·m?2; soil daily total respiration ranges from 0.98―5.17 g·m?2; both daily variations of undisturbed community and soil respiration fluxes are significantly corre- lated (p < 0.05) or extremely significantly correlated (p < 0.01) with air temperatures and ground surface temperatures, but the correlativity with the soil temperature at 5 and 10 cm depths is relatively weak; multiple regression analysis indicates that about 80% of the difference in daily respiration of the undisturbed community among different phenological phases is induced by the variation of the aboveground biomass, while the variations of the remaining factors can jointly explain around 20% of the daily respiration variations of the whole grassland ecosystem; about 83% of the soil daily respiration variation of the different phenological phases is caused by 0―20 cm underground biomass. Besides, surface soil water content is also an important environmental factor affecting soil daily respiration variations of the Aneurolepidium chinense steppe, but its partial correlation coefficient with soil daily respiration amount does not reach the significance level of 0.05.QI Yuchun DONG Yunshe LIU Jiyuan GENG Yuanbo LI Mingfeng YANG Xiaohong LIU Lixin 2005Science China Earth Sciences2005,48,7:11
4Acute calculous cholecystitis associated with hepatic artery pseudoaneurysm after percutaneous transhepatic gallbladder drainage in a diabetic patient显示文摘Patients with acute calculous cholecystitis are usually undertaken surgery laparoscopic cholecystectomy.However,there are controversies about the decision of operation for patients with high risk factors.Percutaneous transhepatic gallbladder drainage (PTGD) is palliative therapy to alleviate symptoms and physical signs.Since improved clinical outcome has been observed for PTGD,it was recommended as an initial therapeutic option for high risk patients who might need surgery.1 Percutaneous drainage in acute calculous cholecystitis for high risk patients is to be a safe and successful treatment option for patients less eligible for surgery.2 PTGD is relatively safe,but has certain complications.We provided a case report of acute calculous cholecystitis associated with hepatic artery pseudoaneurysm after PTGD in a diabetes mellitus patient.The liver vascular pseudoaneurysms and secondary changes of liver were documented by the imaging examination.The complex interactions among inflammation,bleeding,and diabetes mellitus were involved in this case.Tian Hu Xia Mingfeng Zhang Shuai Li Jie Liu Ju 2014Chinese Medical Journal2014,,17:9
5Design of the Metal Precursors Molecular Structures in Impregnating Solutions for Preparation of Efficient Ni Mo/Al_2O_3 Hydrodesulfurization Catalysts显示文摘The molecular structures of metal precursors in the impregnating solution were designed so as to prepare efficient Ni Mo/Al_2O_3 hydrodesulfurization(HDS) catalysts. At first, five typical impregnating solutions were designed; the existing metal precursors, such as [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species in the solutions were confirmed by laser Raman spectroscopy(LRS). The UV-Vis spectra results indicated that the solutions containing both phosphoric acid and citric acid could change the existing form of nickel species. Five corresponding Ni Mo/Al_2O_3 catalysts were prepared by the incipient wetness impregnation method. The LRS analysis results of dried catalysts showed that the above metal precursors could be partly retained on alumina support after impregnation and drying, although the interface reaction between different metal precursors and alumina support unavoidably took place. Then the catalysts were sulfided and characterized by N2 physisorption, TEM and XPS analyses. The results showed that different metal precursors in impregnating solution could mainly result in the difference in both the morphology of(Ni)Mo S2 slabs and the promoting effect of Ni species. The catalyst prepared mainly with [P2Mo5O23]^(6-)-like species used as precursors exhibited worse dispersion of(Ni)Mo S2 slabs and lower ratio of Ni–Mo–S active phases than the one with [Mo4(citrate)2O11]^(4-)-like species. Promisingly, the catalyst prepared with co-existing [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species showed better hydrodesulfurization activity for 4,6-DMDBT thanks to its more well-dispersed Ni–Mo–S active phases.Li Huifeng Li Mingfeng Chu Yang Liu Feng Nie Hong 2015China Petroleum Processing & Petrochemical Technology2015,17,4:8
6Discrimination of False Negative Results in RT-PCR Detection of SARS-CoV-2 RNAs in Clinical Specimens by Using an Internal Reference显示文摘Reverse transcription-polymerase chain reaction(RT-PCR)is an essential method for specific diagnosis of SARS-CoV-2 infection.Unfortunately,false negative test results are often reported.In this study,we attempted to determine the principal causes leading to false negative results of RT-PCR detection of SARS-CoV-2 RNAs in respiratory tract specimens.Multiple sputum and throat swab specimens from 161 confirmed COVID-19 patients were tested with a commercialfluorescent RT-PCR kit targeting the ORF1 ab and N regions of SARS-CoV-2 genome.The RNA level of a cellular housekeeping gene ribonuclease P/MRP subunit p30(RPP30)in these specimens was also assessed by RT-PCR.Data for a total of 1052 samples were retrospectively re-analyzed and a strong association between positive results in SARS-CoV-2 RNA tests and high level of RPP30 RNA in respiratory tract specimens was revealed.By using the ROC-AUC analysis,we identified Ct cutoff values for RPP30 RT-PCR which predicted false negative results for SARS-CoV-2 RT-PCR with high sensitivity(95.03%–95.26%)and specificity(83.72%–98.55%)for respective combination of specimen type and ampli-fication reaction.Using these Ct cutoff values,false negative results could be reliably identified.Therefore,the presence of cellular materials,likely infected host cells,are essential for correct SARS-CoV-2 RNA detection by RT-PCR in patient specimens.RPP30 could serve as an indicator for cellular content,or a surrogate indicator for specimen quality.In addition,our results demonstrated that false negativity accounted for a vast majority of contradicting results in SARS-CoV-2 RNA test by RT-PCR.Yafei Zhang Changtai Wang Mingfeng Han Jun Ye Yong Gao Zhongping Liu Tengfei He Tuantuan Li Mengyuan Xu Luping Zhou Guizhou Zou Mengji Lu Zhenhua Zhang 2020Virologica Sinica2020,35,6:5
7Therapeutic effect of natural melanin from edible fungus Auricularia auricula on alcohol-induced liver damage in vitro and in vivo显示文摘This study explored the therapeutic effects of Auricularia auricula melanin(AAM)on alcoholic liver damage in vitro and in vivo.Human normal liver L02 cells were pre-treated with ethanol and then treated with AAM to explore the therapeutic effect of AAM on ethanol-induced hepatocyte injury.The results show that AAM signifi cantly elevated the cell viability,ameliorated the cell morphology,reduced the ROS and increased the GSH/GSSG of ethanol-pretreated L02 cells.Then,mice were administered with ethanol to induce acute alcoholic liver damage,and administered with AAM to further study the therapeutic effect of AAM on alcoholic liver damage in mice.As a result,AAM reduced the levels of ALT,AST,TG,and MDA,increased the levels of ADH,SOD,and CAT in liver damage mice.The therapeutic effect of AAM may be related to inhibition of CYP2E1 expression and activation of Nrf2 and its downstream antioxidase.The research enriched the bioactivity of AAM and provided some ideas for the development of melanin-related health foods.Ruolin Hou Xin Liu Xiaoping Wu Mingfeng Zheng Junsheng Fu 2021Food Science and Human Wellness2021,10,4:4
8Thermodynamics of strange quark matter with the density-dependent bag constant显示文摘The thermodynamics of strange quark matter with density dependent bag constant are studied self-consistently in the framework of the general ensemble theory and the MIT bag model.In our treatment,an additional term is found in the expression of pressure.With the additional term,the zero pressure locates exactly at the lowest energy state,indicating that our treatment is a self-consistently thermodynamic treatment.The self-consistent equations of state of strange quark matter in both the normal and color-flavor-locked phase are derived.They are both softer than the inconsistent ones.Strange stars in both the normal and color-flavor locked phase have smaller masses and radii in our treatment.It is also interesting to find that the energy density at a star surface in our treatment is much higher than that in the inconsistent treatment for both phases.Consequently,the surface properties and the corresponding observational properties of strange stars in our treatment are different from those in the inconsistent treatment.ZHU MingFeng LIU GuangZhou YU Zi XU Yan SONG WenTao 2009Science China(Physics,Mechanics & Astronomy)2009,52,10:3
92022 Chinese expert consensus and guidelines on clinical management of toxicity in anti-CD19 chimeric antigen receptor T-cell therapy for B-cell non-Hodgkin lymphoma显示文摘Adoptive cellular immunotherapy with chimeric antigen receptor(CAR)T cells has emerged as a novel modality for treating relapsed and/or refractory B-cell non-Hodgkin lymphoma(B-NHL).With increasing approval of CAR T-cell products and advances in CAR T cell therapy,CAR T cells are expected to be used in a growing number of cases.However,CAR T-cell-associated toxicities can be severe or even fatal,thus compromising the survival benefit from this therapy.Standardizing and studying the clinical management of these toxicities are imperative.In contrast to other hematological malignancies,such as acute lymphoblastic leukemia and multiple myeloma,anti-CD19 CAR T-cell-associated toxicities in B-NHL have several distinctive features,most notably local cytokine-release syndrome(CRS).However,previously published guidelines have provided few specific recommendations for the grading and management of toxicities associated with CAR T-cell treatment for B-NHL.Consequently,we developed this consensus for the prevention,recognition,and management of these toxicities,on the basis of published literature regarding the management of anti-CD19 CAR T-cell-associated toxicities and the clinical experience of multiple Chinese institutions.This consensus refines a grading system and classification of CRS in B-NHL and corresponding measures for CRS management,and delineates comprehensive principles and exploratory recommendations for managing anti-CD19 CAR T-cell-associated toxicities in addition to CRS.Ping Li Yang Liu Yun Liang Jian Bo Sujun Gao Yongxian Hu Yu Hu He Huang Xiaojun Huang Hongmei Jing Xiaoyan Ke Jianyong Li Yuhua Li Qifa Liu Peihua Lu Heng Mei Ting Niu Yongping Song Yuqin Song Liping Su Sanfang Tu Jianxiang Wang Depei Wu Zhao Wang Kailin Xu Zhitao Ying Qingming Yang Yajing Zhang Fengxia Shi Bin Zhang Huilai Zhang Xi Zhang Mingfeng Zhao Weili Zhao Xiangyu Zhao Liang Huang Jun Zhu Wenbin Qian Weidong Han Aibin Liang 2023Cancer Biology & Medicine2023,20,2:3
10Distribution of Asbestos Enterprises and Asbestosis Cases--China, 1997−2019显示文摘What is already known on this topic?Asbestos is classified as a Class I Carcinogen by the International Agency for Research on Cancer(IARC)because exposure causes mesothelioma and lung cancer in addition to asbestosis and plaques.So far,asbestos has been banned in 67 countries,but chrysotile,a commonly encountered form of asbestos,is still widely used in China and most developing countries.Most asbestos-caused cancers are not reported,recorded,and compensated in many countries.What is added by this report?Enterprises manufacturing asbestos products have been migrating from economically developed Eastern China to relatively underdeveloped central and western regions between 2010 and 2019.Asbestosis cases reported in Tianjin,Beijing,Shandong,Xinjiang,Gansu,Qinghai,and Sichuan accounted for a large proportion of the total cases in China,which was inconsistent with the distribution of asbestos-related enterprises(AREs).The reported asbestosis cases versus total pneumoconiosis cases declined from 2.81%to 0.39%from 2006–2017,and this proportion reached 0.69%in 2018.What are the implications for public health practice?Robust occupational and environmental health assessments and reporting are needed to define the epidemiology of asbestos-related lung diseases,and management of using asbestos and existing products containing asbestos need strengthening and follow-up.Enterprises should be encouraged to use safer substitutes and gradually ban asbestos materials in China.Mingfeng Chen Huanqiang Wang Jianfang Zhang Chen Yu Weidong Liu Yunhao Xu 2020China CDC weekly2020,2,18:2
11Asymptomatic patients and asymptomatic phases of Coronavirus Disease 2019(COVID-19):a population-based surveillance study显示文摘In this population-based study,we identified 307 confirmed COVID-19 cases from massive surveillance,including 129551 individuals screened at fever clinics or returning from Hubei and 3710 close contacts of confirmed COVID-19 patients.Among them,17 patients were asymptomatic at initial clinical assessment.These asymptomatic patients on admission accounted for a small proportion of all patients(5.54%)with relatively weak transmissibility,and the detection rate was 0.35 per 100 close contacts.Moreover,the dynamics of symptoms of the 307 patients showed that the interval from symptom remission to the final negativity of viral nucleic acid was 5.0 days(interquartile range 2.0 to 11.0 days),with 14 patients(4.56%)having re-detectable viral RNA after discharge.Overall;our findings suggested asymptomatic carriers and presymptomatic patients only accounted for a small proportion of COVID-19 patients.Also,the asymptomatic phase during recovery from COVID-19 implied that negativity in viral RNA is necessary as a de-isolation criterion and follow-up is recommended.Xueying Zheng Sihui Luo Yong Sun Mingfeng Han Jian Liu Liangye Sun Liangming Zhang Ping Ling Yu Ding Tengchuan Jin Zhirong Liu Jianping Weng 2020National Science Review2020,7,10:2
12Overexpression of OsSPL9 enhances accumulation of Cu in rice grain and improves its digestibility and metabolism显示文摘Copper(Cu)is an essential trace mineral element for all forms of life,and is an important structural component and co-factor for a variety of metalloenzymes(Pen^a et al.,1999;Bertinato and L'Abbe,2004).In humans,Cu deficiency is not common because of the ubiquitous occurrence of Cu and ease of gastrointestinal absorption(Zidar et al.,1977;Uauy et al.,1998).However,because of the low Cu content in most sources of feed,the use of Cu as a growth promoter to maximize animal production has been well documented in animal feeding(Braude,1945;Lu et al.,2010).Pre-Mingfeng Tang Chuanshe Zhou Lu Meng Donghai Mao Can Peng Yuxing Zhu Daoyou Huang Zhiliang Tan Caiyan Chen Chengbing Liu Dechun Zhang 2016Journal of Genetics and Genomics2016,43,11:2
13Experimental and simulation studies on concentration polarization in tt2 enrichment by highly permeable and selective Pd membranes显示文摘Zhang Jian Liu Dongyu He Mingfeng 2006Journal of Membrane Science2006,274,:1
14Genomic Characterization, Localization, and Functional Expression of FGL2, the Human Gene Encoding Fibroleukin: A Novel Human Procoagulant显示文摘Sivashankary Yuwaraj JinWen Ding Mingfeng Liu Philip A. Marsden Gary A. Levy 2001Genomics2001,,3:1
15The integrin-linked kinase gene up-regulated by hypoxia plays its pro-survival role in colorectal cancer cells显示文摘Lei Xiao Xiaolong Yue Xiaodong Ming Lishan Xu Mingfeng Ding Jun Xu Qian Liu 2013Journal of Receptors and Signal Transduction2013,,1:1
16Determination of Arctic melt pond fraction and sea ice roughness from Unmanned Aerial Vehicle (UAV) imagery显示文摘Melt ponds on Arctic sea ice are of great significance in the study of the heat balance in the ocean mixed layer, mass and salt balances of Arctic sea ice, and other aspects of the earth-atmosphere system. During the 7 th Chinese National Arctic Research Expedition, aerial photographs were taken from an Unmanned Aerial Vehicle over an ice floe in the Canada Basin. Using threshold discrimination and three-dimensional modeling, we estimated a melt pond fraction of 1.63% and a regionally averaged surface roughness of 0.12 for the study area. In view of the particularly foggy environment of the Arctic, aerial images were defogged using an improved dark channel prior based image defog algorithm, especially adapted for the special conditions of sea ice images. An aerial photo mosaic was generated, melt ponds were identified from the mosaic image and melt pond fractions were calculated. Three-dimensional modeling techniques were used to generate a digital elevation model allowing relative elevation and roughness of the sea ice surface to be estimated. Analysis of the relationship between the distributions of melt ponds and sea ice surface roughness shows that melt ponds are smaller on sea ice with higher surface roughness, while broader melt ponds usually occur in areas where sea ice surface roughness is lower.WANG Mingfeng SU Jie LI Tao WANG Xiaoyu JI Qing CAO Yong LIN Long LIU Yilin 2018Advances in Polar Science2018,29,3:1
17Experimental study of melt electrospinning in parallel electrical field显示文摘HAO Mingfeng LIU Yong HE Xuetao 2011Advanced Materials Research2011,,211:1
18Biomass Catalytic Pyrolysis with Ni Based Catalyst to Produce Hydrogen Rich Gas显示文摘Hydrogen rich gas was produced using rice husk as biomass material on the continuous biomass pyrolysis apparatus which consisted of continuous pyrolysis reactor and secondary catalytic cracking reactor. Ni based catalysts of different Ni/Al mass ratio and calcined temperature were prepared by impregnating method. The catalysts were characterized by X-ray diffraction (XRD), scan electron microscope (SEM) and FT-IR Spectrometer (FT-IR). Ni based catalyst showed good selectivity for H2 production from biomass. Catalysts prepared under different conditions had little influence on the yields of three states products when used at the same cracking temperature. Ni/Al mass ratio played an important role in products selectivity. However, the content of NiO increased further when Ni/Al mass ratio values reached 0.7 : 10, and the yield of H2 slightly increased. Hydrogen yield was greatly impacted by calcined temperature. Catalyst calcined at 550℃ performed best. When the catalyst was calcined at high temperature, NiO in the catalyst transformed into NiAl2O4, and the acid site also changed, which caused the deactivation of the catalyst. The hydrogen yield increased with the cracking temperature. The highest stable yield of hydrogen was about 30% without increasing with the cracking temperature.WANG Mingfeng LIU Min XU Xiwei LI Bosong ZHANG Qiang JIAN Enchen 2010Journal of Northeast Agricultural University(English Edition)2010,17,4:1
19Cold water stress attenuates dopaminergic neurotoxicity induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in mice显示文摘在现在的学习,我们在导致的 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP ) 在 dopaminergic 神经原上测试了冷水应力(CWS ) 的效果 Parkinson 是疾病(PD ) 老鼠模型,并且发现那个 CWS 预告的处理得到了更少的 MPTP neurotoxicity。理解位于这现象下面的分子的机制,我们在试验性的鼠标的 striatum 检测了热吃惊蛋白质 70 的表达式(Hsp70 ) ,并且发现那个 CWS 预告的处理能显著地在对待 MPTP 的鼠标增加 striatal Hsp70。与 Hsp70 的正式就职同时,而且, striatal -synuclein 的导致 MPTP 的增加在 CWS +对待 MPTP 的老鼠被禁止。CWS 预告的处理显著地也在 striatum 禁止了 anti-apoptotic 分子 Bcl-2 表示的减小并且在对待 MPTP 的老鼠的 substantia nigra 提高了 Bcl-2 抄写。一起拿,这些数据显示 Hsp70 可能是为对导致 MPTP 的 dopaminergic 毒性的 CWS 的 neuroprotective 效果的重要中介。Mingfeng Xia Minjuan Bian Qian Yu Jie Liu Yufang Huang Xueting Jin Shiduo Lu Mei Yu Fang Huang 2011Acta Biochimica et Biophysica Sinica2011,43,6:1
20Protective effect of flavonoids from Scutellaria baicalensis Georgi on cerebral ischemia injury显示文摘Yongyu Zhang Xiaoyan Wang Xiaorong Wang Zhaohui Xu Zhe Liu Qian Ni Xiangping Chu Mingfeng Qiu Aihua Zhao Wei Jia 2006Journal of Ethnopharmacology2006,,3:1
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