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Valence-band hybridization endows the reaction specificity of AgPd nanozyme for exclusive peroxidase mimicking and improved sensing performance
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作者 Peng Jin Sili Lin +3 位作者 Dongmei Wang Jinsong Fan Qingyun Liu Kun Li 《Chinese Chemical Letters》 2025年第11期264-269,共6页
Nanozymes,characterized by their stability,cost-effectiveness,and tunable catalytic activity,are promising alternatives to natural enzymes.However,specifically mimicking a single natural enzyme's activity presents... Nanozymes,characterized by their stability,cost-effectiveness,and tunable catalytic activity,are promising alternatives to natural enzymes.However,specifically mimicking a single natural enzyme's activity presents a challenge.By exploiting the catalytic selectivity derived from the valence-band hybridization of noble metal nanoalloys,we introduce an alloying strategy to modulate the reaction specificity of metallic nanozymes.Ag Pd nanoalloy exhibits enhanced peroxidase-like activity and eliminated oxidase-like activity by adjusting the Ag content.The introduction of Ag changes the hybrid d band energy of the alloyed metal and inhibits the O_(2)adsorption and decomposition on Pd,while improving the peroxidase mimicry by allowing for the H_(2)O_(2)activation.By exemplifying the construction of a highly sensitive and selective colorimetric glucose detection platform with its practicality validated in serum samples,this strategy pioneers a multi-noble metal nanozyme with tailored peroxidase activity based on the chemical structure engineering and would advance the development of single-catalytic function nanozymes for building exclusively specific biosensors through reducing substrate competition. 展开更多
关键词 Reaction specificity PEROXIDASE Silver PALLADIUM NANOALLOY Glucose detection
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Light-controlled protein imprinted nanospheres with variable recognition specificity
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作者 Mingqi Wang Shixin Fa +4 位作者 Jiate Yu Guoxian Zhang Yi Yan Qing Liu Qiuyu Zhang 《Chinese Chemical Letters》 2025年第2期145-150,共6页
This work develops a protein imprinted nanosphere with varied recognition specificity for bovine serum albumin(BSA)and lysozyme(Lyz)under different UV light through a gradient dual crosslinked imprinting strategy(i.e.... This work develops a protein imprinted nanosphere with varied recognition specificity for bovine serum albumin(BSA)and lysozyme(Lyz)under different UV light through a gradient dual crosslinked imprinting strategy(i.e.,covalent crosslinking and dynamic reversible crosslinking).The imprinting cavities are initially constructed using irreversible covalent crosslinking to specifically recognize BSA,and then the coumarin residues in the imprinting cavities are crosslinked under 365 nm UV light to further imprint Lyz,because Lyz has smaller size than BSA.Since the photo-crosslinking of coumarin is a reversible reaction,the imprinting cavities of Lyz can be de-crosslinked under 254 nm UV light and restore the imprinting cavities of BSA.Moreover,the N-isopropyl acrylamide(NIPAM)and pyrrolidine residues copolymerized in the polymeric surface of the nanospheres are temperature-and p H-responsive respectively.Therefore,the protein rebinding and release behaviors of the nanospheres are controlled by external temperature and p H.As a result,the materials can selectively separate BSA from real bovine whole blood and Lyz from egg white under different UV light.This study may provide a new strategy for construction of protein imprinted materials with tunable specificity for different proteins. 展开更多
关键词 Molecularly imprinting Dynamically reversible crosslinking Stimulus-response Protein recognition Variable specificity
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Reciprocal translocation experiments reveal gut microbiome plasticity and host specificity in a Qinghai-Xizang Plateau lizard
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作者 Wei Yu Jing Yang +6 位作者 Li-Wei Teng Xiao-Long Zhao Ze-Yu Zhu Shuang Cui Wei-Guo Du Zhen-Sheng Liu Zhi-Gao Zeng 《Zoological Research》 2025年第1期139-151,共13页
Animal adaptation to environmental challenges is a complex process involving intricate interactions between the host genotype and gut microbiome composition.The gut microbiome,highly responsive to external environment... Animal adaptation to environmental challenges is a complex process involving intricate interactions between the host genotype and gut microbiome composition.The gut microbiome,highly responsive to external environmental factors,plays a crucial role in host adaptability and may facilitate local adaptation within species.Concurrently,the genetic background of host populations influences gut microbiome composition,highlighting the bidirectional relationship between host and microbiome.Despite this,our understanding of gut microbiome plasticity and its role in host adaptability remains limited,particularly in reptiles.To clarify this issue,we conducted a reciprocal translocation experiment with gravid females of the Qinghai toad-headed lizards(Phrynocephalus vlangalii)between high-altitude(2?600 m a.s.l.)and superhigh-altitude(3?600 m a.s.l.)environments on Dangjin Mountain of the Qinghai-Xizang Plateau,China.One year later,we assessed the phenotypes and gut microbiomes of their offspring.Results revealed significant plasticity in gut microbiome diversity and structure in response to contrasting elevations.Highaltitude conditions increased diversity,and maternal effects appeared to enable high-altitude lizards to maintain elevated diversity when exposed to superhigh-altitude environments.Additionally,superhigh-altitude lizards displayed distinct gut microbiome structures with notable host specificity,potentially linked to their lower growth rates.Overall,these findings underscore the importance of the gut microbiome in facilitating reptilian adaptation to rapid environmental changes across altitudinal gradients.Furthermore,this study provides critical insights into microbial mechanisms underpinning local adaptation and adaptative plasticity,offering a foundation for future research on host-microbiome interactions in evolutionary and ecological contexts. 展开更多
关键词 Gut microbiome PLASTICITY Host specificity Phrynocephalus vlangalii Reciprocal translocated experiment
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Elucidating the Substrate Specificity of Cytochrome P450 Enzymes:Insights into N-and S-Containing Small-Molecule Metabolism
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作者 Chaohua Yan Guilin Wei +4 位作者 Zhuoan Jin Xiaodong Li Liuyi Yang Liwei Zou Ling Yang 《Engineering》 2025年第11期229-250,共22页
Cytochrome P450 enzymes(P450s or CYPs)are the primary metabolic contributors to the absorption,distribution,metabolism,and excretion(ADME)properties of small-molecule drugs.These enzymes can catalyze various types of ... Cytochrome P450 enzymes(P450s or CYPs)are the primary metabolic contributors to the absorption,distribution,metabolism,and excretion(ADME)properties of small-molecule drugs.These enzymes can catalyze various types of reactions,including metabolic reactions that occur at nitrogen(N)and sulfur(S)sites of small molecules.In this review,we conducted a comprehensive statistical analysis of 294 P450s-mediated small-molecule substrates,among which more than 47%substrates contained N and S.The purpose of the analysis is to elucidate the broad-spectrum cross-reactivity and specificity between these substrates and various CYP isoforms across five reaction types.Our findings reveal that substrates with molecular weights greater than 500 Da or less than 200 Da are predominantly governed by the dominant effect of the CYP isoform’s active sites.In contrast,small-to medium-sized molecules with molecular weights ranging from 200 to 400 Da exhibit a stronger dependence on the types of heteroatoms they contain,with the size of the enzyme’s catalytic site(cavity)playing a negligible role in determining substrate specificity.This review starts from the metabolic mechanisms of P450s-mediated N-and S-containing compounds,and systematically analyzes the structural characteristics of substrates involved in N-dealkylation,N-oxidation,and S-oxidation,as well as their metabolic interactions with P450s.These analyses provide a new perspective for improving the existing understanding of the relationship between the P450s substrate specificity and substrate structural characteristics,and offer a valuable perspective for enhancing drug design and predicting metabolic stability based on the P450s-catalyzed reaction framework. 展开更多
关键词 Drug metabolism Cytochrome P450 enzymes Active sites/catalytic sites Substrate specificity N-and S-containing substrates
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Analysis of Seed-specificity of Silencing fad_2 Gene Expression in Transgenic Rapeseed Line W-4(Brassica napus L.) 被引量:3
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作者 陈松 彭琦 +5 位作者 周晓婴 高建芹 张维 张洁夫 浦惠明 戚存扣 《Agricultural Science & Technology》 CAS 2014年第8期1308-1311,1316,共5页
This study was to investigate the efficiency and specificity of RNAi silencing on the expression of endogenous fad2 gene in transgenic line W-4. [Method] The relative expression of fad2 gene in seeds at different deve... This study was to investigate the efficiency and specificity of RNAi silencing on the expression of endogenous fad2 gene in transgenic line W-4. [Method] The relative expression of fad2 gene in seeds at different developmental stages of 7th, 14th, 21st and 28th day after flowering (DAF) as wel as the root, stem, leaf at winter seedling stages of both the transgenic line W-4 and non-transgenic control Westar by real-time fluorescence quantitative PCR. [Results] The results showed the relative expression of fad2 gene was gradual y increasing with the days after flowering in the seeds of the control Westar, while it was found decreasing significantly since the 21st DAF in the seeds of the line W-4. The decline was up to 60% in comparison with the control Westar. However, no significant difference in the relative expression of fad2 gene in other organs like root, stem and leaf was observed between transgenic line W-4 and non-transgenic control Westar. Fatty acid composition analysis showed the oleic acid desaturation parameter(ODP) in seeds of the line W-4 was 0.07 in average, decreased by nearly 75% than control Westar which was 0.24 in average, while no significant difference in the seedling root, stem and leaf was measured between transgenic rapeseed and control. [Conclusion] The results above validated that RNA interference in transgenic rapeseed W-4 is at a seed-specific manner, not interfering with fad2 gene expression in organs such as the root, stem and leaf. The study also found that the period of fad2 gene expres-sion decline was wel coincided with the expression of napin gene, both appeared at the 21st DAF, indicating that the expression of dsRNA of fad2 gene is precisely control ed by the napin promoter. 展开更多
关键词 Transgenic rapeseed Real-time fluorescence quantitative PCR fad2gene Specific expression
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Specificity of acupoint effect and its fundamental laws 被引量:1
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作者 梁繁荣 唐勇 +5 位作者 李瑛 任玉兰 曾芳 赵凌 吴巧凤 黄文静 《World Journal of Acupuncture-Moxibustion》 2009年第1期1-5,共5页
Objective To explore the specificity of acupoint effect and its fundamental laws. Methods We use evidence-based medicine method and data mining technology for ancient and modern acupuncture literature of migraine and ... Objective To explore the specificity of acupoint effect and its fundamental laws. Methods We use evidence-based medicine method and data mining technology for ancient and modern acupuncture literature of migraine and functional dyspepsia to uncover the specificity and its laws. We apply multicenter,randomized controlled trials of acupuncture for migraine to identify the specificity from clini-cal aspects; to explain the biological base of the specificity,we analyze the PET/CT and NMR result on migraine and functional dyspepsia cases treated by acupuncture. Results The viewpoint of specificity of acupoint effect and its two fundamental laws (meridian course specificity and meridian qi convergence specificity)were found both in ancient and modern literature; compared to non-acupoints,the acupoints effect was specific on 180 migraine patients in the randomized controlled trials; the results of PET/CT scan showed that brain response to acupoint needling is more obvious than that of non-acupoint needling; NMR detected the influence on metabolic product of acupoint needling is more apparent than non-acupoint needling. Conclusions Our research confirmed that acupoint effect not only has its specificity but also has two fundamental laws:meridian course specificity and meridian qi convergence specificity,of which the biological base is supported by imaging and metabonomic studies. 展开更多
关键词 Acupoint Effect specificity Literature Research Multi-RCT METABONOMICS
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“低空经济”数据产权制度的法律构造
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作者 王立梅 崔赫 《交大法学》 北大核心 2026年第1期89-102,共14页
低空经济的发展高度依赖数据要素的充分流通与高效配置。然而,当前数据产权制度建设仍处于探索阶段,抽象化的制度设计难以回应具体领域的特殊需求。应从数据产权制度构建的现实困境出发,探索领域化路径具有的必要性与正当性,并以低空经... 低空经济的发展高度依赖数据要素的充分流通与高效配置。然而,当前数据产权制度建设仍处于探索阶段,抽象化的制度设计难以回应具体领域的特殊需求。应从数据产权制度构建的现实困境出发,探索领域化路径具有的必要性与正当性,并以低空经济为切入点,系统分析低空数据活动的独特属性及其对数据产权制度的特殊需求。在此基础上,提出构建低空经济数据产权制度的理论基础和价值目标,设计以分层确权机制、数据流转规则为核心的具体制度方案,以期为破解数据产权一般理论难题提供有益启示,为产业发展提供坚实的制度保障,从而推动我国数据法律制度体系的完善。 展开更多
关键词 低空经济 数据产权 领域化路径 制度构造
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基于病种精细化运营提升医院CMI值的实践探索
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作者 薛梅 陈寒冰 +1 位作者 陈炬均 李浩正 《中国医疗管理科学》 2026年第1期93-98,共6页
目的为应对医院病例组合指数(Case Mix Index,CMI)值排名下降的挑战,以公立医院高质量发展政策为指导,加强学科建设与运营精细化管理,开展病种精细化运营项目,旨在优化病种与收入结构,全面提升医院核心竞争力。方法系统实施病案首页质控... 目的为应对医院病例组合指数(Case Mix Index,CMI)值排名下降的挑战,以公立医院高质量发展政策为指导,加强学科建设与运营精细化管理,开展病种精细化运营项目,旨在优化病种与收入结构,全面提升医院核心竞争力。方法系统实施病案首页质控与DRG深入培训,构建全周期质控机制;加强手术分级管理及诊断操作标准化,保障手术质量安全;建立亚专科评价体系,实施病种成本精细化管理和多学科协作(Multidisciplinary Team,MDT)模式,实现运营与临床深度融合。结果项目的实施显著改善了医院关键指标:CMI值提升6.57%,时间消耗指数与费用消耗指数分别下降2.89%和4.58%;四级手术占比、RW≥1.5病例占比持续提高;学科布局更加合理,成本控制成效显著,耗材与药品占比进一步降低。结论病种精细化运营通过“病案筑基—技术提级—运营续航”的闭环路径,有效解决了学科与运营脱节问题,实现了CMI与学科能力的协同提升,为公立医院高质量发展提供可推广的实践范式。 展开更多
关键词 CMI值 病种管理 医院高质量发展
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Progress of reseach on specificity of meridian acupoint efficacy 被引量:1
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作者 李凌鑫 孟智宏 +1 位作者 樊小农 石学敏 《World Journal of Acupuncture-Moxibustion》 2012年第2期55-59,共5页
The status quo of study on specificity of meridian acupoints is summarized in this article through retrieval of relative literatures published in the recent 10 years in databases such as CNKI and SCI. The result indic... The status quo of study on specificity of meridian acupoints is summarized in this article through retrieval of relative literatures published in the recent 10 years in databases such as CNKI and SCI. The result indicates that specificity, which is brought into play through the inner biological mechanism, can be found in meridian acupoint efficacy. However, problems still remain since studies at present are still not systematic, comprehensive and scientific. In the future, relative studies should be carried out on extensive diseases and disease models with modern scientific technologies and equipments, strict as well as scientific experimental designation and evaluation methods. 展开更多
关键词 acupuncture efficacy specificity of meridian acupoint REVIEW
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A Simple and Rapid Method to Determine the CO_2/O_2 Specificity Factor for Rubisco
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作者 李国富 陆巍 +5 位作者 李森 公衍道 张秀芳 张荣铣 周海梦 赵南明 《Acta Botanica Sinica》 CSCD 2000年第12期1304-1307,共4页
A simple and rapid new method is presented to determine the CO 2/O 2 specificity factor for ribulose_1,5_bisphosphate(RuBP) carboxylase/oxygenase (Rubisco). In principle, the quantitative formula, which intrinsicall... A simple and rapid new method is presented to determine the CO 2/O 2 specificity factor for ribulose_1,5_bisphosphate(RuBP) carboxylase/oxygenase (Rubisco). In principle, the quantitative formula, which intrinsically resulted in error or enormous error in all reported methods, was improved to circumvent the problem. In practice, the complicated procedure with radiolabelling and chromatographic separation of 3_phosphoglycerate and 2_phosphoglycolate was substituted by one_step procedure without radiolabelling and chromatographic separation to decrease the random error. The effects of pH, temperature and ionic strength on accuracy of the data and the reliability of the calculation of the CO 2/O 2 specificity factor are also discussed. 展开更多
关键词 RUBISCO CO 2/O 2 specificity factor ERROR accuracL
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Analysis on 16S-ITS Marker from Bacillus licheniformis and Its Specificity
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作者 陈冲 佟建明 张潞生 《Agricultural Science & Technology》 CAS 2011年第11期1572-1573,1588,共3页
[Objective] This study aimed to establish molecular identification methods for Bacillus licheniformis. [Method] Based on clone sequencing and difference analysis for 16S and ITS sequences of B. licheniformis TS-01, sp... [Objective] This study aimed to establish molecular identification methods for Bacillus licheniformis. [Method] Based on clone sequencing and difference analysis for 16S and ITS sequences of B. licheniformis TS-01, specific primers were designed using region sequences as the targets used for amplifying all test strains. [Result] The specific primers of B. licheniformis were designed from the ITS and 16S rDNA regions. The optimal annealing temperature of the specific primers for PCR was 67.2 ℃ with 24 cycles. A 905 bp marker fragment was amplified for B. licheniformis TS-01, while all other test strains showed negative results. This indicated that a specific 16S-ITS marker was obtained, which accurately identified the strain at the species level. [Conclusion] This molecular identification method for B. licheniformis TS-01 has laid the foundation for molecular diagnosis of B. licheniformis. 展开更多
关键词 Bacillus licheniformis Specific primer 16S ITS
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New insights into the homeostatic role of Lrig1 in different neurogenic niches:Implications for neuronal regeneration
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作者 Ana Paula De Vincenti Fernanda Ledda Gustavo Paratcha 《Neural Regeneration Research》 2026年第4期1544-1545,共2页
Stem cell proliferation is tightly regulated in developing and adult tissues through the coordinated action of cell-intrinsic and extracellular signals.Although many extracellular cues were identified,the cell-intrins... Stem cell proliferation is tightly regulated in developing and adult tissues through the coordinated action of cell-intrinsic and extracellular signals.Although many extracellular cues were identified,the cell-intrinsic mechanisms underlying the decision of a stem cell to proliferate,enter a dormant quiescent state or differentiate into a specific cell type remains incompletely understood. 展开更多
关键词 neuronalregeneration neurogenicniches stem cell homeostaticrole dormant quiescent state differentiate specific cell type Lrig stemcellproliferation
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Gap-free,haplotype-resolved genome assembly reveals allele-specific expression and fruit color regulation in coconut
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作者 Min Chen Jing Li +6 位作者 Ziqi Ye Xiwei Sun Xiaomei Liu Hao Ding Lixia Zhou Xingtan Zhang Yaodong Yang 《Horticultural Plant Journal》 2026年第1期217-220,共4页
Coconut(Cocos nucifera L.),a major oil and fruit crop of the Arecaceae family,is extensively cultivated across the Asia—Pacific region.Despite its agricultural importance,genome assembly in coconut remains challengin... Coconut(Cocos nucifera L.),a major oil and fruit crop of the Arecaceae family,is extensively cultivated across the Asia—Pacific region.Despite its agricultural importance,genome assembly in coconut remains challenging due to its large genome size and high proportion of repetitive sequences.Allele-specific expression(ASE)plays a key role in regulating plant development and evolution,yet research on ASE in coconut is limited(Shao et al.,2019;Li et al.,2021;Zhang et al.,2021;Hu et al.,2022).Among phenotypic traits,fruit color is especially important as an indicator of maturity,guiding harvest timing and post-harvest processes(Kapoor et al.,2022).While prior studies have explored various coconut traits such as salt tolerance,fiber content,and plant height(Wang et al.,2021;Yang et al.,2021),investigations into ASE and fruit color remain scarce. 展开更多
关键词 allele specific expression Cocos nucifera haplotype resolved fruit color Asia Pacific region COCONUT phenotypic trai oil fruit crop
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Utilizing Single-cell and Spatial RNA-seq databasE for Alzheimer’s Disease(ssREAD)in hypothesis-driven queries
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作者 Diana Acosta Cankun Wang +1 位作者 Qin Ma Hongjun Fu 《Neural Regeneration Research》 2026年第2期677-678,共2页
Alzheimer’s disease(AD)is the most common form of dementia.In addition to the lack of effective treatments,there are limitations in diagnostic capabilities.The complexity of AD itself,together with a variety of other... Alzheimer’s disease(AD)is the most common form of dementia.In addition to the lack of effective treatments,there are limitations in diagnostic capabilities.The complexity of AD itself,together with a variety of other diseases often observed in a patient’s history in addition to their AD diagnosis,make deciphering the molecular mechanisms that underlie AD,even more important.Large datasets of single-cell RNA sequencing,single-nucleus RNA-sequencing(snRNA-seq),and spatial transcriptomics(ST)have become essential in guiding and supporting new investigations into the cellular and regional susceptibility of AD.However,with unique technology,software,and larger databases emerging;a lack of integration of these data can contribute to ineffective use of valuable knowledge.Importantly,there was no specialized database that concentrates on ST in AD that offers comprehensive differential analyses under various conditions,such as sex-specific,region-specific,and comparisons between AD and control groups until the new Single-cell and Spatial RNA-seq databasE for Alzheimer’s Disease(ssREAD)database(Wang et al.,2024)was introduced to meet the scientific community’s growing demand for comprehensive,integrated,and accessible data analysis. 展开更多
关键词 sex specific alzheimer s disease ad deciphering molecular mechanisms spatial transcriptomics ssread spatial transcriptomics st Alzheimers disease single cell RNA seq
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New Extracellular Bacillus subtilis Lectins with Sialic Acid-Specificity
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作者 Valentin Podgorsky Emma Kovalenko +2 位作者 Iryna Karpova Elena Sashchuk Ekaterina Getman 《Journal of Agricultural Science and Technology(A)》 2014年第6期541-546,共6页
The purpose of this work is to perform a detailed study of carbohydrate specificity of the new extracellular bacilli lectins which is considered to determine mechanisms of the lectins action. Sources of lectins were b... The purpose of this work is to perform a detailed study of carbohydrate specificity of the new extracellular bacilli lectins which is considered to determine mechanisms of the lectins action. Sources of lectins were bacterial strains from Ukrainian collection of microorganisms. The optimized protocol of bacilli lectins isolation and purification included precipitation with ammonium sulfate with subsequent gel filtration chromatography on Sepharose CL-6B. Hemagglutinating activity of bacilli lectins and their fine carbohydrate specificity to sialic acids and their derivatives as well as sialic asid-containing and asialic glycoconjugates were studied. The ability of extracellular bacilli lectins to discriminate a- and 13-conformation of carbohydrate molecule and the type of connection between the monomers was determined. Studied lectins showed the most affinity to glycoconjugates containing both types of sialic acids (N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (NeuGc)) and it is supposed to be a basis of their diagnostic and analytical potential. 展开更多
关键词 Bacillus subtilis LECTINS sialic acids specificity.
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磁共振mDixon技术在骨质疏松症中的定量研究
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作者 王梦娇 邓静 +5 位作者 刘珍珍 胡海峰 王余广 张天宇 刘海燕 罗琳 《黑龙江医药科学》 2026年第1期9-12,共4页
目的:探讨磁共振m Dixon技术在诊断骨质疏松症(OP)中的应用价值。方法:选取2025年2月至2025年6月于齐齐哈尔医学院附属第二医院就诊的105例同时做DXA骨密度检测及MRI检查的患者为研究对象。依据我国骨质疏松和骨矿盐疾病学协会提出的诊... 目的:探讨磁共振m Dixon技术在诊断骨质疏松症(OP)中的应用价值。方法:选取2025年2月至2025年6月于齐齐哈尔医学院附属第二医院就诊的105例同时做DXA骨密度检测及MRI检查的患者为研究对象。依据我国骨质疏松和骨矿盐疾病学协会提出的诊断标准将上述患者分为正常组、骨量减少组、骨质疏松组。检测3组BMD、T2^(*)、FF值,比较3组患者一般临床资料差异,分析T2^(*)、FF值与BMD的相关性,并构建ROC曲线检验T2^(*)、FF值在诊断骨质疏松及骨量减少的准确性及特异性。结果:3组患者年龄、BMI、BMD值、25(OH)维生素D、PTH、钙摄入、骨折史、糖皮质激素使用、磁共振定量参数差异有统计学意义(P<0.05)。FF值、T2^(*)值在3组间呈梯度上升。Pearson相关分析结果显示,FF、T2^(*)与BMD呈显著负相关。FF用于诊断OP的AUC面积为0.983,灵敏度为0.91,特异度为0.83,T2^(*)用于诊断OP的AUC面积为0.945,灵敏度为0.87,特异度为0.79。FF用于诊断骨量减少的AUC面积为0.876,灵敏度为0.82,特异度为0.73,T2^(*)用于诊断骨量减少的AUC面积为0.922,灵敏度为0.88,特异度为0.76。结论:磁共振mDixon定量技术通过FF和T2^(*)参数,能有效反映骨髓脂肪成分及其变化趋势,与骨密度密切相关,尤其在OP的早期识别和诊断中展现出良好的敏感性与特异性。 展开更多
关键词 磁共振mDixon 骨质疏松症 准确性 特异性
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降水变化对荒漠草原植物群落主要物种气孔形态和光合生理特性的影响
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作者 邓文辉 宋珂辰 +4 位作者 张浩 管思雨 雍嘉仪 谢铁娜 胡海英 《草业学报》 北大核心 2026年第1期65-78,共14页
本研究以宁夏荒漠草原植物群落的主要物种短花针茅、赖草、牛枝子、银灰旋花、远志为对象,设置增加50%自然降水量(PA),自然降水量(CK),减少50%自然降水量(PR)3个处理,研究了不同降水量下,荒漠草原主要植物叶片光合、气孔形态特征、水分... 本研究以宁夏荒漠草原植物群落的主要物种短花针茅、赖草、牛枝子、银灰旋花、远志为对象,设置增加50%自然降水量(PA),自然降水量(CK),减少50%自然降水量(PR)3个处理,研究了不同降水量下,荒漠草原主要植物叶片光合、气孔形态特征、水分利用效率的变化,揭示了荒漠草原主要植物对降水改变的光合适应机制,以期为荒漠草原生态系统管理以及应对全球气候变化趋势所带来的影响提供理论依据。结果表明:在荒漠草原,植物通过增加叶片气孔的周长和面积来降低蒸腾速率和气孔导度,从而降低净光合速率、提高水分利用效率达到适应干旱环境的目的。其中银灰旋花的净光合速率对降水量变化最敏感,PA处理下的净光合速率是PR处理的6.65倍,同时其水分利用效率最低。而赖草对水分的利用能力最高,短花针茅和远志次之。各主要群落植物的比叶面积指数均随降水量减少而显著增大(P<0.05)。植物叶片气孔形状偏向于圆形会增加植物的水分利用效率,而叶片气孔形状偏向于长形会增加植物的净光合速率。综合分析后可以看出,这5种植物中光合和水分利用的生态适应能力的高低为短花针茅>赖草>远志>银灰旋花>牛枝子。 展开更多
关键词 荒漠草原 降水变化 光合作用 气孔特征 δ^(13)C 比叶面积
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乙烯环氧化反应中高比表面积、高通透性银催化剂载体研究
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作者 王辉 《石油化工》 北大核心 2026年第1期15-21,共7页
为了开发乙烯环氧化反应中高比表面积、高通透性银催化剂载体,以新型含铝前体(氢氧化铝)、新型造孔剂(含碳物质)为研究对象,采用XRD、比表面分析仪、强度测试仪、SEM、压汞仪、TG-DSC等手段研究新型含铝前体和新型造孔剂对银催化剂载体... 为了开发乙烯环氧化反应中高比表面积、高通透性银催化剂载体,以新型含铝前体(氢氧化铝)、新型造孔剂(含碳物质)为研究对象,采用XRD、比表面分析仪、强度测试仪、SEM、压汞仪、TG-DSC等手段研究新型含铝前体和新型造孔剂对银催化剂载体性能的影响,并通过乙烯环氧化反应评价银催化剂催化性能。实验结果表明,新型含铝前体及新型造孔剂的添加能够提高载体比表面积、渗透性及通透性,还可提高氧化铝片层的规整度,由此载体制备的银催化剂在乙烯环氧化反应中表现很高的催化性能。 展开更多
关键词 银催化剂 载体 比表面积 孔道
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海岛恶劣环境对滨海特有的滨柃群落功能性状的影响
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作者 钟址非 王晓盈 +5 位作者 肖自新 朱琦琦 王彬彬 许艳蓉 李培杨 邓传远 《东北林业大学学报》 北大核心 2026年第1期68-74,101,共8页
为揭示盐雾、强风、土壤贫瘠等海岛恶劣环境对滨海特有滨柃群落功能性状的影响机制,以福建平潭7个海岛的102个滨柃群落样方为研究对象,采用群落加权平均值表征群落水平功能性状,结合相关性分析、最优模型筛选及结构方程模型,解析环境因... 为揭示盐雾、强风、土壤贫瘠等海岛恶劣环境对滨海特有滨柃群落功能性状的影响机制,以福建平潭7个海岛的102个滨柃群落样方为研究对象,采用群落加权平均值表征群落水平功能性状,结合相关性分析、最优模型筛选及结构方程模型,解析环境因子对功能性状的作用路径与贡献权重。结果表明:滨柃群落功能性状存在显著权衡,呈现保守型资源利用策略,树高与叶面积、比叶面积呈极显著负相关(p<0.01),与叶厚度、干材密度呈极显著正相关(p<0.01);在土壤因子中,全氮、有效磷及水溶性盐总量为关键因子,高pH促进树高但抑制叶面积,钾元素增加叶厚度与叶干物质质量分数;气候与地形因子通过直接与间接作用共同调控性状,海拔促进叶面积与比叶面积,样地离海岸线距离增加使叶干物质质量分数上升、种子质量下降,年均温与降水量增加使比叶面积升高。 展开更多
关键词 海岛 滨海特有物种 滨柃 群落加权平均值 功能性状
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石灰消化制备高比表面氢氧化钙及其铅吸附性能研究
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作者 陈建军 李力 +5 位作者 刘来宝 张岱宇 姜晨曦 竹含真 王辅 廖其龙 《无机盐工业》 北大核心 2026年第1期99-106,共8页
为探究不同烷醇胺改性剂对Ca(OH)_(2)理化性质和微观结构的影响,以及所制备的高比表面积Ca(OH)_(2)对铅吸附性能的影响,分别以三异丙醇胺(TIPA)、二乙醇单异丙醇胺(DEIPA)、三乙醇胺(TEA)为改性剂,生石灰为原料,采用消化法制备出片层状... 为探究不同烷醇胺改性剂对Ca(OH)_(2)理化性质和微观结构的影响,以及所制备的高比表面积Ca(OH)_(2)对铅吸附性能的影响,分别以三异丙醇胺(TIPA)、二乙醇单异丙醇胺(DEIPA)、三乙醇胺(TEA)为改性剂,生石灰为原料,采用消化法制备出片层状、高比表面积氢氧化钙,将其应用于含铅废水的处理。利用X射线衍射仪、高真空气体吸附分析仪、激光粒度仪、场发射扫描电镜对制备的Ca(OH)_(2)进行表征分析,结果表明,以TEA为改性剂获得的片层状Ca(OH)_(2)性能最佳,其比表面积、孔体积和平均孔径分别为53.94 m^(2)/g、0.208 cm^(3)/g和11.66 nm。同时,揭示高比表面积片层状Ca(OH)_(2)可能的形成机理。此外,Ca(OH)_(2)对铅的吸附过程更符合Langmuir模型(R^(2)=0.992 5)和准二级动力学模型(R^(2)=0.999 7),主要是以化学吸附为主的单分子吸附过程,同时伴随着少量物理吸附,其对水中铅的吸附率达99.54%,残留铅的质量浓度≤0.46 mg/L,远低于排放限值,证实烷醇胺改性Ca(OH)_(2)在含铅废水处理方面有广阔的应用前景。 展开更多
关键词 高比表面积Ca(OH)_(2) 石灰消化 吸附铅 烷醇胺改性剂
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