检索结果-南通市图书馆

Detection of Serine Octamer by Desorption Electrospray Ionization Mass Spectrometry in Resultant Mixture of Aspartic Acid Exposed to Sunshine Under Natural Conditions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2007年第6期23卷 650-653页

作者： chen huan-wen LI Ming JIN Wei JIN Qin-han ZHENG Jian College of Chemistry Jilin Province Research Center of Engineering and Technology for Spectral Instruments Jilin University Changchun 130021 P. R. China Applied Chemistry Department East China University of Technology Fuzhou 344000 P. R. China College of Information Science and Engineering Zhejiang University Hangzhou 310027 P. R. China Beijing Physical and Chemical Analysis Center Beijing 100089 P. R. China

Serine, one of the nonessential amino acids, is of principal interest because of its capability to form magic-number ionic clusters, which provide a remarkable preference for homochirality. With L-aspartic acid as the precursor, this study provides experimental evidence for serine formation in weak acidified aqueous solutions in the presence of iron, with exposure to sunlight, which simulates the natural conditions of the prebiotic aqueous environment. The resultant mixture is directly analyzed via desorption electrospray ionization mass spectrometry（ DESI-MS）, without any sample preseparation. The serine monomer is successfully detected as protonated molecules, giving a peak at m/z 106, which is confirmed by the MS/MS fragments. Protonated serine octamer（ m/z 841 ） is also observed with significant abundance in the MS spectra and is confirmed by the MS/MS data, which shows the formation of the serine octamer by a synthesized serine in the resultant mixture. It is also found that the serine octamer yielded equivalent abundance in the DESI mass spectra in a wide pH range（pH = 1-5 ）, and that existence of ferrous salt and sunshine are essential for the conversion of aspartic acid to serine in the acidic water solution.

关键词： Serine octamer Aspartic acid Photocatalysis DESI Mass spectrometry

Pogostemon cablin essential oil as feed additive promotes the repair of the rumen epithelial barrier in heat-stressed beef cattle

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第3期18卷 433-440页

作者： huan chen Mingrui Yang Xianglong Shang Hao chen Yi Li Yanjiao Li Lin Li Mingren Qu Xiaozhen Song Jiangxi Province Key Laboratory of Animal Nutrition Engineering Research Center of Feed DevelopmentJiangxi Agricultural UniversityNanchang 330045China

Pogostemon cablin essential oil(PEO),extracted from ***,has anti-oxidant,anti-inflammatory,and anti-stress properties,as well as the ability to improve gastrointestinal *** study aims to evaluate the effects of PEO on the performance,rumen epithelial morphology,and barrier function in heat-stressed beef ***-six male Jingjiang cattle at 18 months old were randomly assigned into four groups and fed a diet containing PEO at 0(control),50,100,or 150 mg/kg in the feed concentrate(n=9).All experimental cattle were fed under high temperature and humidity in summer for 60 *** results indicated that 50 mg/kg of PEO treatment enhanced the average daily gain of beef cattle compared with the control group(P=0.032).All PEO treatments reduced the diamine oxidase activity(P=0.004)and malondialdehyde content(P=0.008)in *** addition,the content of 70 kDa heat shock protein in the 100 mg/kg group was increased,and the activity of glutathione peroxidase and total antioxidant capacity in both 100 mg/kg and 150 mg/kg groups were enhanced compared to the control group(P<0.05).More importantly,PEO treatment with 50 mg/kg enhanced the mRNA relative expressions of occludin in ruminal epithelia but decreased the mRNA relative expressions of c-Jun N-terminal kinase,P38 mitogen-activated protein kinases,caspase-3,Beclin1(P<0.05),and extremely significant declined the mRNA relative expressions of extracellular regulated protein kinases and ubiquitin-binding protein in contrast to the control group(P<0.01).These findings indicated that dietary PEO supplementation might be favorable to improve growth performance and repairing damaged rumen epithelium of heat-stressed cattle by down-regulating the mitogen-activated protein kinase signaling pathway.

关键词： Beef cattle Heat stress Rumen epithelial barrier Pogostemon cablin essential oil Growth performance MAPK signaling pathway

ZmbZIP27 regulates nitrogen-mediated leaf angle by modulating lignin deposition in maize

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2024年第5期12卷 1404-1413页

作者： huan chen Xiaoping Gong Yu Guo Jingjuan Yu Wen-Xue Li Qingguo Du State Key Laboratory of Crop Gene Resources and Breeding National Engineering Laboratory for Crop Molecular BreedingInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China State Key Laboratory of Plant Environmental Resilience College of Biological SciencesChina Agricultural UniversityBeijing 100193China

In grain crops such as maize(Zea mays),leaf angle(LA)is a key agronomic trait affecting light interception and thus planting density and ***(N)affects LA in plants,but we lack a good understanding of how N regulates ***,we report that N deficiency enhanced lignin deposition in the ligular region of maize *** situ hybridization showed that the bZIP transcription factor gene ZmbZIP27 is mainly expressed in the phloem of maize vascular *** N-sufficient conditions,transgenic maize overexpressing ZmbZIP27 showed significantly smaller LA compared with wild type(WT).By contrast,zmbzip27_(ems)mutant showed larger LA under both N-deficient and N-sufficient conditions compared with *** of ZmbZIP27 enhanced lignin deposition in the ligular region of maize in the *** further demonstrated that ZmbZIP27 could directly bind the promoters of the microRNA genes ZmMIR528a and ZmMIR528b and negatively regulate the expression levels of ***528 knockdown transgenic maize displayed erect architecture in the field by increasing lignin content in the ligular region of *** together,these results indicate that ZmbZIP27 regulates N-mediated LA size by regulating the expression of ZmmiR528 and modulating lignin deposition in maize.

关键词： Maize Nitrogen Leaf angle Ligular region Lignin deposition

Evaluating two stages of silicone-containing arylene resin oxidation via experiment and molecular simulation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第2期66卷 189-202页

作者： Jiangtao Cai Qingfu huang huan chen Tao Zhang Bo Niu Yayun Zhang Donghui Long Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China Key Laboratory of Special Functional Polymeric Materials and Related Technology(Ministry of Education) School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

Silicon-containing aryl acetylene resin(PSA)is a new type of high-temperature resistant resin with excellent oxidation resistance,whereas antioxidant reaction mechanism of PSA resin under ultra-high temperatures still remains ***,the oxidation behavior and mechanisms of PSA resin are systematically investigated combining kinetic analysis and Reax FF molecular dynamics(MD)*** analysis indicates that the oxidation process of PSA resin undergoes two main steps:oxidative mass gain and oxidative *** distributed activation energy model(DAEM)is employed for describing oxidation processes and the best-fit one is obtained using genetic algorithms and differential *** model demonstrates that the oxidative weight gain stage is dominated by two virtual reactants and the oxidative degradation stage consists of three virtual ***,the observation of MD reaction pathways indicates that oxygen oxidation of unsaturated structures occurs in the initial stage,which results in the formation of PSA resin ***,cracked pieces react with O_(2)to generate CO and other chemicals in the second *** resin matrix's great antioxidation resilience is illustrated by the formation of SiO_(2).The analysis based on MD simulations exhibits an efficient computational proof with the experiments and DAEM *** on the results,a two-stage reaction mechanism is proposed,which provides important theoretical support for the subsequent study of the oxidation behavior of silica-based resins.

关键词： PSA resin Oxidative degradation Thermogravimetric analysis DAEM reaction kinetics ReaxFF simulation

Urchin-like Nb_(2)O_(5)hollow microspheres enabling efficient and selective photocatalytic C–C bond cleavage in lignin models under ambient conditions

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第9期33卷 4357-4362页

作者： huan chen Donghui Hong Kun Wan Junjie Wang Bo Niu Yayun Zhang Donghui Long State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China Shanghai Key Laboratory of Multiphase Materials Chemical Engineering East China University of Science and TechnologyShanghai 200237China

Selective cleavage of robust C−C bonds to harvest value-added aromatic oxygenates is an intriguing but challenging task in lignin *** is a promising technology with the advantages of mild reaction conditions and strong ***,we show a novel urchin-like Nb_(2)O_(5)hollow microsphere(U-Nb_(2)O_(5)HM),prepared by one-pot hydrothermal method,are highly active and selective for C_(α)−C_(β)bond cleavage of ligninβ-O-4 model compounds under mild conditions,achieving 94%substrate conversion and 96%C−C bond cleavage *** experimental studies and density functional theory(DFT)calculations revealed that the superior performance of U-Nb_(2)O_(5)HMs arises from more exposed active sites,more efficient free charge separation and the active(001)facet,which facilitates the activation of Cβ−H bond of lignin models and generate key Cβradical intermediates by photogenerated holes,further inducing the C_(α)−C_(β)bond cleavage to produce aromatic *** work could provide some suggestions for the fabrication of hierarchical photocatalysts in the lignin depolymerization system.

关键词： Niobium oxide Urchin-like hierarchical structure Photocatalysis β-O-4 Lignin model C_(β)radical

TIRggering cell death via two enzymatic reactions

在线全文

学校读者我要写书评

暂无评论

Molecular Plant 2022年第8期15卷 1263-1265页

作者： Na Liu huan chen Xu Wang Daowen Wang Zheng Qing Fu College of Life Sciences Henan Agricultural UniversityZhengzhou 450002China Department of Biological Sciences University of South CarolinaColumbiaSC29208USA State Key Laboratory of Wheat and Maize Crop Science College of AgronomyCenter for Crop Genome EngineeringHenan Agricultural UniversityZhengzhou 450002China

Plant pathogens rely on effectors that are delivered into host cells to cause *** fight back,plants acquired nucleotidebinding site-leucine-rich repeat(NB-LRR or NLR)resistance proteins to recognize these pathogen effectors directly or to detect the activities of these effectors indirectly,triggering effectortriggered immunity(ETI)(Cui et al.,2015).These sensorNLRs also carry a variable toll/interleukin-1 receptor(TIR)or coiledcoil domain on their N termini.

关键词： immunity death

Long-term inorganic plus organic fertilization increases yield and yield stability of winter wheat

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Crop Journal 2018年第6期6卷 589-599页

作者： huan chen Aixing Deng Weijian Zhang Wei Li Yuqiang Qiao Taiming Yang chengyan Zheng chengfu Cao Fu chen College of Agronomy and Biotechnology China Agricultural UniversityBeijing 100193China Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing 100081China Crop Research Institute Anhui Academy of Agricultural SciencesHefei 230031AnhuiChina Anhui Center of Agricultural Meteorology Hefei 230031AnhuiChina

An understanding of wheat yield and yield stability response to fertilization is important for sustainable wheat production. A 36-year long-term fertilization experiment was employed to evaluate the yield and yield stability of winter wheat. Five fertilization regimes were compared,including(1) CK, no fertilizer;(2) NPK, inorganic fertilizer only;(3) O, organic fertilizer only;(4)NPKO, 50% of NPK plus 50% of O, and(5) HNPKO, 80% of NPK plus 80% of O. The greatest yield increase was recorded in HNPKO, followed by NPKO, with O producing the lowest mean yield increase. Over the 36 years, the rate of wheat yield increase in fertilized plots ranged from95.31 kg ha-1 year-1 in the HNPKO to 138.65 kg ha-1 year-1 in the O. Yield stability analysis using the additive main effects and multiplicative interactions(AMMI) method assigned 62.3%, 26.3%,and 11.4% of sums of squares to fertilization effect, environmental effect, and fertilization ×environment interaction effect, respectively. The combination of inorganic and organic fertilization(NPKO and HNPKO) appeared to produce more stable yields than O or NPK, with lower coefficients of variation and AMMI stability value. However, wheat grown with O seemed to be the most susceptible to climate change and the least productive among the fertilized *** correlations of grain yield with soil properties and with mean air temperature were observed. These findings suggest that inorganic + organic fertilizer can increase wheat yield and its stability by improvement in soil fertility and reduction in variability to climate change.

关键词： Winter wheat Grain yield Yield stability AMMI analysis Long-term fertilization

Comparison analysis between haplo identical stem cell transplantation and matched sibling donor stem cell transplantation for high-risk acute myeloid leukemia in first complete remission

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2019年第5期62卷 691-697页

作者： Yang Liu Xiaojun huang Qian Fei Lanping Xu Xiaohui Zhang Kaiyan Liu Yuhong chen huan chen Yu Wang Peking University People's Hospital Peking University Institute of Hematology

In order to compare the effect between haploidentical(HID) stem cell transplantation(HSCT) and matched sibling donor(MSD)stem cell transplantation for high-risk acute myeloid leukemia(AML) in first complete remission status(CR1), we retrospectively studied 170 cases who received stem cell transplantation from Jan 2008 to Jul 2015 in Peking University People's Hospital. We divided all cases into MSD group(43 cases) and HID(127 cases) group. Patients in HID and MSD group displayed similar baseline characteristics except for age distribution. There were no statistic differences for overall survival(OS), cumulative incidence of relapse, leukemia free survival(LFS), transplantation related mortality(TRM) between HID and MSD group. The 3-year OS, LFS for all patients was 63.9% and 59.7% respectively. Multivariate analysis showed that grade III-IV acute graft versus host disease(aGVHD) was an independent risk factor for treatment related mortality(HR=8.134, 95% CI:3.210–20.611, P<0.001), monosomy/complex chromosomal karyotype and white blood cell count more than 50×109 L-1 were two independent factors for relapse(HR=1.533, 95% CI: 1.040–2.260, P=0.031)(HR=1.004, 95% CI: 1.001–1.008, P=0.015).Grade III-IV aGVHD was an independent factor for mortality(HR=3.184, 95% CI: 1.718–5.902, P<0.001). These results demonstrated some risk factors for high-risk AML leukemia transplantation and indicated for AML patients in CR1 status, haplo stem cell transplantation could have the same therapeutic effect as MSD transplantation.

关键词： high risk AML haplo stem cell transplantation matched sibling donor transplantation complex/monosomy chromosomal karyotype

Effects of gold core size on regulating the performance of doxorubicin-conjugated gold nanoparticles

在线全文

学校读者我要写书评

暂无评论

Nano Research 2018年第6期11卷 3396-3410页

作者： Dongyan Wu Huaisong Wang Xiaoshuang Hou huan chen Yu Ma Yanglong Hou Jin Hong Ya Ding State Key Laboratory of Natural Medicines Department of Pharmaceutical Analysis China Pharmaceutical University Nanjing 210009 China Department of Biochemistry School of Life Science and Technology China Pharmaceutical University Nanjing 210009 China Beijing Key Laboratory for Magnetoelectric Materials and Devices (BKLMMD) Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT) Department of Materials Science and Engineering College of Engineering Peking University Beijing 100871 China Key Laboratory of Biomedical Functional Materials School of Sciences China Pharmaceutical University Nanjing 210009 China

Studies on the influence of one critical parameter （e.g., size）, targeting a specific disease, while keeping other factors unchanged, are important for improving understanding and application of the molecular design of biomedical nanomaterials. In this study, we used doxorubicin （Dox）-conjugated gold nanoparticles （GNPs） to investigate the effects of the size of the gold core （10, 20, or 60 nm） on the performance of their conjugates. We found that all three conjugates differed slightly in their physicochemical properties, facilitating a direct and accurate assessment of the size effects of GNP-Dox conjugates on their in vitro and in vivo performance. The cytological properties （the cell penetration rate and efficiency, as well as the cytotoxicity） and antitumor performance （the intratumoral penetration, treatment efficacy, and biodistribution） were highly correlated to the size of the inorganic core. Among all test groups, although the conjugate with a 60-nm gold core had the highest drug loading and release efficiency, the conjugate with a 10-nm gold core displayed the best antitumor efficacy toward the liver cancer models. This was because it showed the deepest tumor permeability and the highest tumor cell-killing ability of Dox transported by the relatively small GNPs. This study provides important evidence for better understanding the effect of size on in vitro and in vivo properties of potential therapeutic nanosystems and their structure design.

关键词： size effect doxorubicin-conjugated gold nanoparticles antitumor efficacy tumor penetration liver cancer