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Achieving structurally stable O3-type layered oxide cathodes through site-specific cation-anion co-substitution for sodium-ion batteries
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作者 Yihao Shen Chen Cheng +5 位作者 Xiao Xia Lei Wang Xi Zhou Pan Zeng Jianrong Zeng Liang Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期411-418,I0011,共9页
O3-type layered oxides have garnered great attention as cathode materials for sodium-ion batteries because of their abundant reserves and high theoretical capacity.However,challenges persist in the form of uncontrolla... O3-type layered oxides have garnered great attention as cathode materials for sodium-ion batteries because of their abundant reserves and high theoretical capacity.However,challenges persist in the form of uncontrollable phase transitions and intricate Na^(+)diffusion pathways during cycling,resulting in compromised structural stability and reduced capacity over cycles.This study introduces a special approach employing site-specific Ca/F co-substitution within the layered structure of O_(3)-NaNi_(0.5)Mn_(0.5)O_(2) to effectively address these issues.Herein,the strategically site-specific doping of Ca into Na sites and F into O sites not only expands the Na^(+)diffusion pathways but also orchestrates a mild phase transition by suppressing the Na^(+)/vacancy ordering and providing strong metal-oxygen bonding strength,respectively.The as-synthesized Na_(0.95)Ca_(0.05)Ni_(0.5)Mn_(0.5)O_(1.95)F_(0.05)(NNMO-CaF)exhibits a mild O3→O3+O'3→P3 phase transition with minimized interlayer distance variation,leading to enhanced structural integrity and stability over extended cycles.As a result,NNMO-CaF delivers a high specific capacity of 119.5 mA h g^(-1)at a current density of 120 mA g^(-1)with a capacity retention of 87.1%after 100 cycles.This study presents a promising strategy to mitigate the challenges posed by multiple phase transitions and augment Na^(+)diffusion kinetics,thus paving the way for high-performance layered cathode materials in sodium-ion batteries. 展开更多
关键词 Sodium-ion batteries O3-type layered oxides site-specific co-doping Phase transition
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Collagen1α1 promoter drives the expression of Cre recombinase in osteoblasts of transgenic mice 被引量:1
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作者 Lagabaiyila Zha Ning Hou +4 位作者 Jian Wang Guan Yang Yuanrong Gao Lin Chen Xiao Yang 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2008年第9期525-530,共6页
Osteoblasts participate in bone formation, bone mineralization, osteoclast differentiation and many pathological processes. To study the function of genes in osteoblasts using Cre-LoxP system, we generated a mouse lin... Osteoblasts participate in bone formation, bone mineralization, osteoclast differentiation and many pathological processes. To study the function of genes in osteoblasts using Cre-LoxP system, we generated a mouse line expressing the Cre recombinase under the control of the rat Collagenlcd (Collα1) promoter (Collα1-Cre). Two founders were identified by genomic PCR from 16 offsprings, and the integration efficiency is 12.5%. In order to determine the tissue distribution and the activity of Cre recombinase in the transgenic mice, the Coll αl-Cre transgenic mice were bred with the ROSA26 reporter strain and a mouse strain that carries Smad4 conditional alleles (Smad4^Co/Co). Multiple tissue PCR of Collα1-Cre;Smad4^Co/+ mice revealed the restricted Cre activity in bone tissues containing osteoblasts and tendon. LacZ staining in the Collα1-Cre;ROSA26 double transgenic mice revealed that the Cre recombinase began to express in the osteoblasts of calvaria at E14.5. Cre activity was observed in the osteoblasts and osteocytes of P10 double transgenic mice. All these data indicated that the Collα1-Cre transgenic mice could serve as a valuable tool for osteoblast lineage analysis and conditional gene knockout in osteoblasts. 展开更多
关键词 Collagenl OSTEOBLAST Cre recombinase transgenic mouse
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Recombinase polymerase amplification as a promising tool in hepatitis C virus diagnosis 被引量:14
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作者 Hosam Zaghloul Mahmoud El-shahat 《World Journal of Hepatology》 CAS 2014年第12期916-922,共7页
Hepatitis C virus(HCV)infection represents a significant health problem and represents a heavy load on some countries like Egypt in which about 20%of the total population are infected.Initial infection is usually asym... Hepatitis C virus(HCV)infection represents a significant health problem and represents a heavy load on some countries like Egypt in which about 20%of the total population are infected.Initial infection is usually asymptomatic and result in chronic hepatitis that give rise to complications including cirrhosis and hepatocellular carcinoma.The management of HCV infection should not only be focus on therapy,but also to screen carrier individuals in order to prevent transmission.In the present,molecular detection and quantification of HCV genome by real time polymerase chain reaction(PCR)represent the gold standard in HCV diagnosis and plays a crucial role in the management of therapeutic regimens.However,real time PCR is a complicated approach and of limited distribution.On the other hand,isothermal DNA amplification techniques have been developed and offer molecular diagnosis of infectious dieses at point-of-care.In this review we discuss recombinase polymerase amplification technique and illustrate its diagnostic value over both PCR and other isothermal amplification techniques. 展开更多
关键词 Hepatitis C virus Nucleic acid testing Polymerase chain reaction POINT-OF-CARE recombinase polymerase amplification
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Spatial variability of soil properties in red soil and its implications for site-specific fertilizer management 被引量:6
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作者 SONG Fang-fang XU Ming-gang +5 位作者 DUAN Ying-hua CAI Ze-jiang WEN Shi-lin CHEN Xian-ni SHI Wei-qi Gilles COLINET 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第9期2313-2325,共13页
Assessing spatial variability and mapping of soil properties constitute important prerequisites for soil and crop management in agricultural areas. To explore the relationship between soil spatial variability and land... Assessing spatial variability and mapping of soil properties constitute important prerequisites for soil and crop management in agricultural areas. To explore the relationship between soil spatial variability and land management, 256 samples were randomly collected at two depths (surface layer 0–20 cm and subsurface layer 20–40 cm) under different land use types and soil parent materials in Yujiang County, Jiangxi Province, a red soil region of China. The pH, soil organic matter (SOM), total nitrogen (TN), cation exchange capacity (CEC), and base saturation (BS) of the soil samples were examined and mapped. The results indicated that soils in Yujiang were acidified, with an average pH of 4.87 (4.03–6.46) in the surface layer and 4.99 (4.03–6.24) in the subsurface layer. SOM and TN were significantly higher in the surface layer (27.6 and 1.50 g kg–1, respectively) than in the subsurface layer (12.1 and 0.70 g kg–1, respectively), while both CEC and BS were low (9.0 and 8.0 cmol kg–1, 29 and 38% for surface and subsurface layers, respectively). Paddy soil had higher pH (mean 4.99) than upland and forest soils, while soil derived from river alluvial deposits (RAD) had higher pH (mean 5.05) than the other three parent materials in both layers. Geostatistical analysis revealed that the best fit models were exponential for pH and TN, and spherical for BS in both layers, while spherical and Gaussian were the best fitted for SOM and CEC in the surface and subsurface layers. Spatial dependency varied from weak to strong for the different soil properties in both soil layers. The maps produced by selecting the best predictive variables showed that SOM, TN, and CEC had moderate levels in most parts of the study area. This study highlights the importance of site-specific agricultural management and suggests guidelines for appropriate land management decisions. 展开更多
关键词 spatial variability soil pH CEC BS site-specific fertilizer management
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Effects of Site-Specific Nitrogen Management on Yield and Dry Matter Accumulation of Rice from Cold Areas of Northeastern China 被引量:7
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作者 PENG Xian-long LIU Yuan-ying +3 位作者 LUO Sheng-guo FAN Li-chun SONG Tian-xing GUO Yan-wen 《Agricultural Sciences in China》 CAS CSCD 2007年第6期715-723,共9页
The effects of yield increase and mechanism of site-specific nitrogen management (SSNM) in five rice varieties from cold areas of northeastern China were studied. Plot experiment for critical SPAD value and experime... The effects of yield increase and mechanism of site-specific nitrogen management (SSNM) in five rice varieties from cold areas of northeastern China were studied. Plot experiment for critical SPAD value and experiments of two fertilization methods, SSNM and farmer's fertilization practice (FFP) were conducted to study their effects on the quality and dry matter accumulation of rice population, as well as N uptake. Compared with FFP, SSNM significantly decreased the average N rate by 33.8%, significantly increased average ear-bearing tiller rate and LAI for grain-filling stage by 12.3% and 14.1-27.6%, correspondingly, improved dry matter weight and N uptake after heading period by 4.3-29.1% and 11.8-55.1% (P 〈 0.05), and heightened recovery efficiency and agronomic efficiency by 38.5-133.4% (P 〈 0.05) and 39.8-194.3% (P 〈 0.05), respectively, as well as increased the average yield by 9.8% in 2004 and 2005. The results indicated that the accumulation rate of dry matter and N increased the rice yield and N use efficiency, because of improving rice population quality and increasing LAI after heading period. 展开更多
关键词 cold areas RICE site-specific nitrogen management YIELD dry matter N use efficiency
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Visual Detection of Vibrio parahaemolyticus using Combined CRISPR/Cas12a and Recombinase Polymerase Amplification 被引量:8
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作者 JIANG Han Ji TAN Rong +8 位作者 JIN Min YIN Jing GAO Zhi Xian LI Hai Bei SHI Dan Yang ZHOU Shu Qing CHEN Tian Jiao YANG Dong LI Jun Wen 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2022年第6期518-527,共10页
Objective To establish an ultra-sensitive,ultra-fast,visible detection method for Vibrio parahaemolyticus(VP).Methods We established a new method for detecting the tdh and trh genes of VP using clustered regularly int... Objective To establish an ultra-sensitive,ultra-fast,visible detection method for Vibrio parahaemolyticus(VP).Methods We established a new method for detecting the tdh and trh genes of VP using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 12a(CRISPR/Cas12a)combined with recombinase polymerase amplification and visual detection(CRISPR/Cas12a-VD).Results CRISPR/Cas12a-VD accurately detected target DNA at concentrations as low as 10^(-18)M(single molecule detection)within 30 min without cross-reactivity against other bacteria.When detecting pure cultures of VP,the consistency of results reached 100%compared with real-time PCR.The method accurately analysed pure cultures and spiked shrimp samples at concentrations as low as 10^(2)CFU/g.Conclusion The novel CRISPR/Cas12a-VD method for detecting VP performed better than traditional detection methods,such as real-time PCR,and has great potential for preventing the spread of pathogens. 展开更多
关键词 Vibrio parahaemolyticus CRISPR/Cas12a-VD Isothermal amplification recombinase polymerase amplification Visual detection CROSS-REACTIVITY
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Development of a radiolabeled site-specific single-domain antibody positron emission tomography probe for monitoring PD-L1 expression in cancer 被引量:2
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作者 Yinfei Chen Shiyu Zhu +6 位作者 Jiayu Fu Jianguo Lin Yan Sun Gaochao Lv Minhao Xie Tao Xu Ling Qiu 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2022年第6期869-878,共10页
Despite advances in immunotherapy for the treatment of cancers,not all patients can benefit from programmed cell death ligand 1(PD-L1)immune checkpoint blockade therapy.Anti-PD-L1 therapeutic effects reportedly correl... Despite advances in immunotherapy for the treatment of cancers,not all patients can benefit from programmed cell death ligand 1(PD-L1)immune checkpoint blockade therapy.Anti-PD-L1 therapeutic effects reportedly correlate with the PD-L1 expression level;hence,accurate detection of PD-L1 expression can guide immunotherapy to achieve better therapeutic effects.Therefore,based on the high affinity antibody Nb109,a new site-specifically radiolabeled tracer,^(68)Ga-NODA-cysteine,aspartic acid,and valine(CDV)-Nb109,was designed and synthesized to accurately monitor PD-L1 expression.The tracer ^(68)Ga-NODA-CDV-Nb109 was obtained using a site-specific conjugation strategy with a radiochemical yield of about 95%and radiochemical purity of 97%.It showed high affinity for PD-L1 with a dissociation constant of 12.34±1.65 nM.Both the cell uptake assay and positron emission tomography(PET)imaging revealed higher tracer uptake in PD-L1-positive A375-hPD-L1 and U87 tumor cells than in PD-L1-negative A375 tumor cells.Meanwhile,dynamic PET imaging of a NCI-H1299 xenograft indicated that doxorubicin could upregulate PD-L1 expression,allowing timely interventional immunotherapy.In conclusion,this tracer could sensitively and dynamically monitor changes in PD-L1 expression levels in different cancers and help screen patients who can benefit from anti-PD-L1 immunotherapy. 展开更多
关键词 Single-domain antibody site-specific labeling Immuno-PET imaging PD-L1
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Construction of Marker-Free GFP Transgenic Tobacco by Cre/lox Site-Specific Recombination System 被引量:4
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作者 SONG Hong-yuan REN Xue-song SI Jun LI Cheng-qiong SONG Ming 《Agricultural Sciences in China》 CAS CSCD 2008年第9期1061-1070,共10页
Marker-free GFP transgenic tobacco plants were constructed based on Cre/lox site-specific recombination system. A GFP gene was introduced into the tobacco genome using the Bar gene as a linked selectable marker flanke... Marker-free GFP transgenic tobacco plants were constructed based on Cre/lox site-specific recombination system. A GFP gene was introduced into the tobacco genome using the Bar gene as a linked selectable marker flanked by recombination sites in a directed orientation. The Bar gene expression box was subsequently excised from the plant genome by a strategy of Cre gene retransformation. After removal of the Cre-NPT Ⅱ locus by genetic segregation through self-cross, plants that incorporated only the GFP transgene were obtained. Transgenic tobacco plants mediated by Agrobacterium tumefaciens were obtained, which resisted herbicide Basta and GFP expressed well, then the Cre gene was subsequently introduced into 5 plants of them, respectively, by retransformation. The leaf disks from Cre transgenic plants were used to test the resistance to Basta on the medium with 8 mg L-1 of PPT. The results showed that few discs were able to regenerate normally, and the excision at 76-100% efficiency depended on individual retransformation events. Evidence for a precise recombination event was confirmed by cloning the nucleotides sequence surrounding the lox sites of the Basta sensitive plants. The result indicated that the excision event in the recombination sites was precise and conservative, without loss or alteration of any submarginal nucleotides of the recombination sites. Bar gene excised plants were selfpollinated to allow segregation of the GFP gene from the Cre-NPT Ⅱ locus. The progenies from self-pollinated plants were scored for Kan senstivity, then the segregation of GFP gene from Cre-NPT Ⅱ locus in the Kan senstive plants were confirmed by PCR analysis subsequently. Hence, constructing marker-free transgenic tobacco plants by Cre/lox sitespecific recombination system was reliable, and the strategy presented here should be applicable to other plants for the construction of marker-free transgenic plants as well. 展开更多
关键词 Cre/lox site-specific recombination system marker-free transgenic tobacco GFP
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The Site-Specific Hydrolysis of l-β-Hydroxybaccatin Ⅱ by Aspergillus Niger 被引量:2
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作者 Jun Zeng ZHANG Li He ZHANG(The National Research Laboratories of Natural and Biomimetic Drugs School of pharmaceutical Sciences, Beijing Medical Uaiversity, Beijing 100083)Di An SUN +1 位作者 Jian Qiao GU Qi Cheng FANG(Institute of Materia MedicaChinese Academy 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第12期1091-1092,共2页
The site-specific microbiological hydrolysis of a natural 1β-hydroxybaccatin I, with the culture of Aspergillus niger. is described.
关键词 SITE The site-specific Hydrolysis of l Hydroxybaccatin by Aspergillus Niger
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Development of a Recombinase-aided Amplification Combined With Lateral Flow Dipstick Assay for the Rapid Detection of the African Swine Fever Virus 被引量:2
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作者 LI Jiang Shuai HAO Yan Zhe +6 位作者 HOU Mei Ling ZHANG Xuan ZHANG Xiao Guang CAO Yu Xi LI Jin Ming MA Jing ZHOU Zhi Xiang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2022年第2期133-140,共8页
Objective To establish a sensitive,simple and rapid detection method for African swine fever virus(ASFV)B646L gene.Methods A recombinase-aided amplification-lateral flow dipstick(RAA-LFD)assay was developed in this st... Objective To establish a sensitive,simple and rapid detection method for African swine fever virus(ASFV)B646L gene.Methods A recombinase-aided amplification-lateral flow dipstick(RAA-LFD)assay was developed in this study.Recombinase-aided amplification(RAA)is used to amplify template DNA,and lateral flow dipstick(LFD)is used to interpret the results after the amplification is completed.The lower limits of detection and specificity of the RAA assay were verified using recombinant plasmid and pathogenic nucleic acid.In addition,30 clinical samples were tested to evaluate the performance of the RAA assay.Results The RAA-LFD assay was completed within 15 min at 37°C,including 10 min for nucleic acid amplification and 5 minutes for LFD reading results.The detection limit of this assay was found to be 200 copies per reaction.And there was no cross-reactivity with other swine viruses.Conclusion A highly sensitive,specific,and simple RAA-LFD method was developed for the rapid detection of the ASFV. 展开更多
关键词 African swine fever virus recombinase aided amplification Lateral flow detection
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Application of site-specific biomass models to quantify spatial distribution of stocks and historical emissions from deforestation in a tropical forest ecosystem 被引量:1
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作者 Cedric A.Goussanou Sabin Guendehou +1 位作者 Achille E.Assogbadjo Brice Sinsin 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第1期205-213,共9页
Allometric equations developed for the Lama forest, located in southern Benin, West Africa, were applied to estimate carbon stocks of three vegetation types:undisturbed forest, degraded forest, and fallow. Carbon sto... Allometric equations developed for the Lama forest, located in southern Benin, West Africa, were applied to estimate carbon stocks of three vegetation types:undisturbed forest, degraded forest, and fallow. Carbon stock of the undisturbed forest was 2.7 times higher than that in the degraded forest and 3.4 times higher than that in fallow. The structure of the forest suggests that the individual species were generally concentrated in lower diameter classes. Carbon stock was positively correlated to basal area and negatively related to tree density, suggesting that trees in higher diameter classes contributed significantly to the total carbon stock. The study demonstrated that large trees constitute an important component to include in the sampling approach to achieve accurate carbon quantification in forestry. Historical emissions from deforestation that converted more than 30% of the Lama forest into cropland between the years 1946 and 1987 amounted to 260,563.17 tons of carbon per year(t CO2/year) for the biomass pool only. The study explained the application of biomass models and ground truth data to estimate reference carbon stock of forests. 展开更多
关键词 Biomass Reference level site-specific biomass model Spatial distribution Tropical forest ecosystem
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Study on Site-specific Nutrient Management in Cotton Field
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作者 YANG Li-ping JIANG Cheng JIN Ji-yun ZHANG Feng-ming 《Agricultural Sciences in China》 CAS CSCD 2001年第1期102-106,共5页
The study on the characteristics of spatial variability of soil nutrients and fertilizer recommendations in cotton field under certain conditions of agricultural management was conducted with GIS and systematic approa... The study on the characteristics of spatial variability of soil nutrients and fertilizer recommendations in cotton field under certain conditions of agricultural management was conducted with GIS and systematic approach for soil nutrient constrains. The results showed that of the spatial variability of soil nutrient was greatly related to the management condition of previous crops. Grid sampling and variable rate application technology (VRAT) were the tools that would hopefully increase fertilizer efficiency. The fertilizers were applied where they were needed and at proper rate. Balance fertilization demonstration showed that fertilizer recommendations according to the available nutrient level in soil could decrease fertilizer cost with 657.4 yuan / ha and increase seed cotton yield by 19.8%. A net profit of the balanced fertilization was 5314.9 yuan / ha higher than that of local fertilization practice. 展开更多
关键词 COTTON field site-specific NUTRIENT management GIS FERTILIZER RECOMMENDATIONS Variable rate FERTILIZATION
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Development of rabbit monoclonal and polyclonal antibodies for detection of site-specific histone modifications and their application in analyzing overall modification levels
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作者 Lan Guo Benliang Yin +2 位作者 Junli Zhou Xueyong Li Xing Wang Deng 《Cell Research》 SCIE CAS CSCD 2006年第5期519-527,共9页
In addition to DNA sequence information, site-specific histone modifications are another important determinant of gene expression in a eukaryotic organism. We selected four modification sites in common histones that a... In addition to DNA sequence information, site-specific histone modifications are another important determinant of gene expression in a eukaryotic organism. We selected four modification sites in common histones that are known to significantly impact chromatin function and generated monoclonal or polyclonal antibodies that recognize each of those site-specific modifications. We used these antibodies to demonstrate that the site-specific histone modification levels remain relatively constant in different organs of the same organism. We also compared the levels of selected histone modifications among several representative organisms and found that site-specific modifications are highly variable among different organisms, providing new insight into the evolutionary divergence of specific histone modifications. 展开更多
关键词 histone modification site-specific antibody CHROMATIN
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Effects of Long-term Site-specific Fertilization on Soil Physical and Chemical Properties and Nutrients in Dry Farmland
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作者 Xiaojun WANG Yuqing SUN +6 位作者 Yong WANG Xiaojuan ZHANG Shangpei ZHANG Junxue YANG Shiwu LUO Jihong SHANG Bingwen CHENG 《Agricultural Science & Technology》 CAS 2017年第11期2118-2122,共5页
In order to investigate the variation in soil physical and chemical properties and nutrients in the mountainous areas in southern Ningxia, and to provide a theoretical basis for fertilization management in local farml... In order to investigate the variation in soil physical and chemical properties and nutrients in the mountainous areas in southern Ningxia, and to provide a theoretical basis for fertilization management in local farmland, the soil p H, total salt content,crop root length, root weight, soil organic matter, available nitrogen, total nitrogen, total phosphorous and total potassium in different fertilization treatments were measured from 2010 to 2016. Multiple comparisons of the data were performed using Duncan's new multiple range test. The results indicated that in the 0-20 cm soil layer, soil p H value and total salt content changed in different patterns, and varied greatly from 2010 to 2016(P<0.05). The changes of both root length and root weight of millet over time fitted S-shaped curves. The root length and root weight in the four fertilization treatments(Treatment 2 to Treatment5) increased faster than those in the control(Treatment 1). The soil organic matter content in all the five treatments gradually increased from 2010 to 2016. The content of alkaline hydrolyzable nitrogen in soil rapidly increased in the first two to three years of the experiment, followed by a slow increase or decrease in 2013, and then raised rapidly again from 2014 to 2016.The soil total nitrogen content varied significantly from 2010 to 2016. The total phosphorus content in soil changed in a different pattern from that of total nitrogen content. The seven-year field trails revealed that soil p H, total salt content, root length, root weight and soil nutrient all changed with the increase of fertilizer level, and that long-term fertilization is of significance for maintaining soil fertility, improving soil quality and reducing soil salinization. 展开更多
关键词 site-specific fertilization Physical and chemical properties NUTRIENT Soil quality
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Chemotactic Activity of Site-Specific Multivalent Conjugates of Stromal Cell-Derived Factor 1<i>α</i>on Branched Nanoparticles
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作者 Yu-Fang Hsieh Fang Huang +1 位作者 Shyam Patel Song Li 《Journal of Biomaterials and Nanobiotechnology》 2018年第1期51-63,共13页
Stromal cell-derived factor 1α (SDF1α) is a potent chemokine for the recruitment of stem cells. A challenge is to maintain its activity and control its release. In this study, we engineered a recombinant cysteine-S... Stromal cell-derived factor 1α (SDF1α) is a potent chemokine for the recruitment of stem cells. A challenge is to maintain its activity and control its release. In this study, we engineered a recombinant cysteine-SDF1α (cysSDF1α) protein, and performed multivalent conjugation of cysSDF1 through the maleimide functional group to two forms of branched nanoparticles: multi-arm poly (ethylene glycol) (MA-PEG) and hyaluronic acid (HA). We characterized the chemotactic activity of the conjugates, and determined how the molecular weight (MW) of MA-PEG and HA affected the chemotactic activity. CysSDF1α had similar efficiency to wild-type SDF1α in cell recruitment. Multivalent conjugation of cysSDF1α to low MW MA-PEG (~18 nm) did not significantly affect the chemotactic activity, while the conjugation of cysSDF1α to high MW MA-PEG (~72 nm) lowered the efficiency, possibly due to the larger spacing between conjugated SDF1α molecules. HA has a linear backbone and a high density of multivalent binding sites;however, the chemotactic activity of HA-linked cys-SDF1α was much lower, which further decreased with the increase of HA MW from 200 kDa (~0.78 μm) to 700 kDa (~2.7 μm). Digestion of HA into smaller fragments using hyaluronidase partially recovered the chemotactic activity of cysSDF1α, suggesting that high MW HA might exert steric hindrance for SDF1α binding to its receptors on cell surface and that HA could be used as a depot for SDF1α storage and release. These results demonstrate that multivalent conjugates of SDF1α to nanoparticles may be used to engineer SDF1α delivery for cell recruitment and tissue regeneration. 展开更多
关键词 SDF1α Delivery Cell Recruitment site-specific PROTEIN Ligation MULTIVALENT PROTEIN CONJUGATES
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Establishment of Recombinase Polymerase Amplification for Rapid Detection of Spring Viremia of Carp Virus(SVCV)
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作者 Liang Junni Yin Weili +3 位作者 Shang Di Liu Ning Duan Xiaohui Lin Sen 《Animal Husbandry and Feed Science》 CAS 2020年第2期29-32,共4页
[Objective]The paper was to develop a rapid method for the detection of spring Viremia of carp virus(SVCV).[Method]The specific primers were designed by targeting the G gene of SVCV.The recombinase polymerase amplific... [Objective]The paper was to develop a rapid method for the detection of spring Viremia of carp virus(SVCV).[Method]The specific primers were designed by targeting the G gene of SVCV.The recombinase polymerase amplification(RPA)assay for detecting SVCV was estab-lished by optimizing the reaction conditions.The optimal amplification temperature of RPA assay was 30℃,and the test could be finished within 20 min.[Result]The method was specific with no cross-reaction with other common fish infectious viruses.Sensitivity test showed that the lowest detection limit of the method was 89.2 copies/μL,higher than that of traditional RT-PCR.Moreover,a total of 80 clinical samples were detected by RPA and RT-PCR,respectively.The weak positive samples tested by RT-PCR could be detectable with RPA,indicating that RPA assay could be used in clinical detection.[Conclusion]The method established is rapid,simple,specific and sensitive for testing SVCV,and it will be widely used in grassroots laboratory and on-site inspection. 展开更多
关键词 recombinase polymerase amplification Rapid detection Spring viremia of carp virus(SVCV)
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Site-specific recombination in Escherichia coli mediated by actinomyces phage R4 integrase
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作者 YAN ZHUO YANG LE KANG PAN +1 位作者 NATSUE SANO MAKOTO SHIRAI 《Journal of Microbiology and Immunology》 2005年第2期136-141,共6页
The purpose of this study was to demonstrate that actinomyces phage R4 integrase Sre protein efficiently mediate site-specific recombination in Escherichia coll. An intramolecular recombination assay system in E. coli... The purpose of this study was to demonstrate that actinomyces phage R4 integrase Sre protein efficiently mediate site-specific recombination in Escherichia coll. An intramolecular recombination assay system in E. coli was constructed. The plasmid pBZP contains attB and attP sites in direct orientation flanking a lacZ gene. When pBZP was introduced into E. coli cells, in which the plasmid pSREA containing sre gene was resident, Sre protein catalyzed integration of attP into attB site, resulting in excision of the lacZ gene. This integration changed bacteria colonies from blue to white on agar plates containing X-Gal, which showed that the lacZ was removed. The integrant DNAs were identified by enzyme digestion, PCR and DNA sequencing. The minimal sizes of attB and attP were 50 bp and 47 bp for 100% recombination efficiency. The phage recombinase Sre efficiently integrated attP into attB site to create attR and attL in E. coli host environment without Streptomyces specific cofactors. This intrmolecular assay system is a simple and efficient system for Sre-mediated recombination in E. coll. 展开更多
关键词 site-specific recombination Sre protein lntramolecular assay system
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基于Cre-loxP重组酶系统构建肺泡Ⅱ型上皮细胞特异性敲除SENP1基因小鼠
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作者 杨坤 章容 +4 位作者 吴越 雷小平 谌云川 康兰 董文斌 《中国组织工程研究》 CAS 北大核心 2025年第14期2943-2950,共8页
背景:前期在体外成功构建了SENP1基因沉默的人肺泡上皮细胞系,在细胞水平上研究了SENP1在高氧性肺损伤中的作用。目的:基于Cre-loxP重组酶系统构建肺泡Ⅱ型上皮细胞特异性敲除SENP1基因小鼠模型。方法:将SENP1^(flox/-)小鼠自交得到SENP... 背景:前期在体外成功构建了SENP1基因沉默的人肺泡上皮细胞系,在细胞水平上研究了SENP1在高氧性肺损伤中的作用。目的:基于Cre-loxP重组酶系统构建肺泡Ⅱ型上皮细胞特异性敲除SENP1基因小鼠模型。方法:将SENP1^(flox/-)小鼠自交得到SENP1^(flox/flox)和SENP1^(flox/-)小鼠;将Sftpc-Cre^(+/+)小鼠与野生型小鼠交配获得更多的Sftpc-Cre^(+/-)小鼠。将Sftpc-Cre^(+/+)或子代Sftpc-Cre^(+/-)小鼠与SENP1^(flox/-)或子代SENP1^(flox/flox)小鼠进行杂交,获得SENP1^(flox/-)Sftpc-Cre^(+/-)双杂合小鼠。将SENP1^(flox/-)Sftpc-Cre^(+/-)小鼠与SENP1^(flox/flox)小鼠杂交,获得SENP1^(flox/flox)Sftpc-Cre^(+/-)小鼠。剪鼠尾提取基因组DNA,行PCR扩增,扩增产物经琼脂糖凝胶电泳确定小鼠基因型。取SENP1^(flox/flox)和SENP1^(flox/flox)Sftpc-Cre^(+/-)小鼠肺组织行免疫荧光双标实验及Western blot以验证SENP1敲除效果;取SENP1^(flox/flox)和SENP1^(flox/flox)Sftpc-Cre^(+/-)小鼠心、肝、肺、肾组织行苏木精-伊红染色以观察两组小鼠各脏器的组织形态。结果与结论:琼脂糖凝胶电泳正确筛选出SENP1^(flox/flox)Sftpc-Cre^(+/-)小鼠。免疫荧光双标实验显示,与SENP1^(flox/flox)小鼠相比,SENP1^(flox/flox)Sftpc-Cre^(+/-)小鼠肺组织中SENP1的平均荧光强度降低(P<0.01),且SENP1和Sftpc未见明显共定位(P<0.01)。Western blot结果显示,与SENP1^(flox/flox)小鼠相比,SENP1^(flox/flox)Sftpc-Cre^(+/-)小鼠肺组织中SENP1蛋白表达降低(P<0.001)。苏木精-伊红染色结果显示SENP1^(flox/flox)和SENP1^(flox/flox)Sftpc-Cre^(+/-)小鼠的心、肝、肺和肾脏组织形态无明显改变。该研究利用Cre-loxP重组酶系统成功构建了肺泡Ⅱ型上皮细胞特异性敲除SENP1基因小鼠,为后续研究SENP1基因在以肺泡Ⅱ型上皮细胞为主要损伤细胞的肺疾病如支气管肺发育不良、特发性肺纤维化中的作用提供了良好的工具。 展开更多
关键词 SENP1 Cre-loxP重组酶系统 肺泡Ⅱ型上皮细胞 条件性基因敲除 小鼠
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快速检测十足目虹彩病毒1 RPA-LFD方法的建立及初步应用 被引量:1
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作者 袁雪梅 陈静 +5 位作者 黄雷 蔺凌云 潘晓艺 彭先启 焦锦彪 姚嘉赟 《中国预防兽医学报》 CAS CSCD 北大核心 2024年第5期505-510,共6页
为建立一种高效、快速、简便的十足目虹彩病毒1(DIV1)检测方法,本研究以DIV1 ATPase基因为检测靶标,设计特异性引物和探针,采用方阵法优化反应温度和时间,结果显示,重组酶聚合酶扩增技术(RPA)最优反应温度为37℃,时间为15 min,结果观察... 为建立一种高效、快速、简便的十足目虹彩病毒1(DIV1)检测方法,本研究以DIV1 ATPase基因为检测靶标,设计特异性引物和探针,采用方阵法优化反应温度和时间,结果显示,重组酶聚合酶扩增技术(RPA)最优反应温度为37℃,时间为15 min,结果观察时间为5 min,检测过程总时长为20 min,初步建立了DIV1的重组酶聚合酶扩增技术结合侧向流试纸条方法(RPA-LFD)。提取其他7种常见虾类病原基因组与DIV1基因组,采用该方法检测,分析其特异性;构建重组质粒标准品p UC57-DIV1,10倍倍比稀释后采用该方法检测,分析其灵敏性;以3种不同浓度的重组质粒标准品为模板进行批间、批内重复性试验。结果显示,该方法能特异性检测DIV1,与虾类其他常见易感病原均无交叉反应;其对重组质粒标准品的检测限为1×10^(1)拷贝/μL;批内和批间重复性试验的检测结果均一致,重复性好。利用该方法与已发表的荧光定量PCR(qPCR)同时检测15份感染DIV1的罗氏沼虾样品及40份临床样品,结果显示,该方法的阳性检测率为69.09%(38/55),阴性率为30.91%(17/55),与q PCR检测结果一致,二者的阳性符合率、阴性符合率、总符合率均为100%。综上所述,本研究建立的RPA-LFD方法检测DIV1具有快速、简便、灵敏度高且特异性强的特点,且不需要精密昂贵的仪器设备,为基层实验室及现场检测提供了可行技术手段。 展开更多
关键词 重组酶聚合酶扩增 侧向流试纸条技术 十足目虹彩病毒I
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肉制品中马源性成分重组酶介导链置换等温扩增实时检测方法的建立及应用 被引量:1
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作者 范维 孔维恒 +3 位作者 高晓月 董雨馨 李贺楠 郭文萍 《食品科学》 EI CAS CSCD 北大核心 2024年第3期203-210,共8页
目的:建立一种快速鉴定肉及肉制品中马源性成分的重组酶介导链置换等温扩增实时检测方法。方法:以马源性ATpase 6基因为靶基因设计多组特异性引物和Exo探针,通过引物筛选及反应参数优化,建立一种采用重组酶介导链置换等温扩增技术检测... 目的:建立一种快速鉴定肉及肉制品中马源性成分的重组酶介导链置换等温扩增实时检测方法。方法:以马源性ATpase 6基因为靶基因设计多组特异性引物和Exo探针,通过引物筛选及反应参数优化,建立一种采用重组酶介导链置换等温扩增技术检测马源性成分的方法,并对该方法进行特异性、灵敏度和稳定性验证,同时通过对不同掺入比例混合样品、不同加工工艺模拟样品和市售样品进行检测,分析方法的检出限、适用性和准确性。结果:该方法反应迅速、特异性强、灵敏度高。可在39℃恒温条件下16min内完成反应;对23种非目标源性具有良好特异性;目标DNA的检测灵敏度可达到1.8copies/μL水平;对生肉的检出限为0.01%(质量分数,下同),对熟肉制品的检出限为0.1%;对90份市售样品进行检测,结果与标准方法一致。结论:建立的重组酶介导链置换等温扩增方法可用于肉及肉制品中马源性成分的掺假鉴别检测。 展开更多
关键词 重组酶介导链置换等温扩增 掺假鉴别 马源性成分 肉及肉制品
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