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Protein Content and Amino Acid Composition in Grains of Wheat-Related Species 被引量:8
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作者 JIANG Xiao-ling TIAN Ji-chun HAO Zhi ZHANG Wei-dong 《Agricultural Sciences in China》 CAS CSCD 2008年第3期272-279,共8页
The protein content and amino acid composition for 17 wheat-related species (WRS) and three common wheats (control) were determined and analyzed, and the essential amino acids (EAAs) in WRS were evaluated accord... The protein content and amino acid composition for 17 wheat-related species (WRS) and three common wheats (control) were determined and analyzed, and the essential amino acids (EAAs) in WRS were evaluated according to FAO/WHO amino acid recommendations. The results showed that the mean protein content for WRS was 16.67%, which was 23.21% higher than that for the control. The mean contents (g 100 g^-1 protein) of most amino acids for WRS were lysine 2.74%, threonine 2.83%, phenylalanine 4.17%, isoleucine 3.42%, valine 3.90%, histidine 2.81%, glutamic acid 29.96%, proline 9.12%, glycine 3.59%, alanine 3.37%, and cysteine 1.57%, which were higher than those for the control. The contents of the other 6 amino acids for WRS were lower than those for the control. The materials (Triticum monococcum L., Triticum carthlicum Nevski, and Triticum turgidum L.) contained relatively high concentration of the most deficient EAAs (lysine, threonine, and methionine). Comparing with FAO/WHO amino acid recommendations, the amino acid scores (AAS) of lysine (49.8%), threonine (70.7%), and sulfur-containing amino acids (74.8%) were the lowest, which were considered as the main limiting amino acids in WRS. It was observed that the materials with Triticum urartu Turn. (AA) and Aegilops speltoides Tausch. (SS) genomes had relatively high contents of protein and EAA. The contents of protein (16.91%), phenylalanine (4.78%), isoleucine (3.53%), leucine (6.16%), and valine (4.09%) for the diploid materials were higher than those for the other materials. These results will provide some information for selecting parents in breeding about nutrient quality and utilization of fine gene in wheat. 展开更多
关键词 wheat-related species protein content amino acid composition amino acid score
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Branched-chain amino acids to tyrosine ratio value as a potential prognostic factor for hepatocellular carcinoma 被引量:10
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作者 Toru Ishikawa 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第17期2005-2008,共4页
The prognosis of hepatocellular carcinoma(HCC) depends on tumor extension as well as hepatic function.Hepatic functional reserve is recognized as a factor affecting survival in the treatment of HCC;the ChildPugh class... The prognosis of hepatocellular carcinoma(HCC) depends on tumor extension as well as hepatic function.Hepatic functional reserve is recognized as a factor affecting survival in the treatment of HCC;the ChildPugh classif ication system is the most extensively used method for assessing hepatic functional reserve in patients with chronic liver disease,using serum albumin level to achieve accurate assessment of the status of protein metabolism.However,insuff icient attention has been given to the status of amino acid(AA) metabolism in chronic liver disease and HCC.Fischer's ratio is the molar ratio of branched-chain AAs(BCAAs:leucine,valine,isoleucine) to aromatic AAs(phenylalanine,tyrosine) and is important for assessing liver metabolism,hepatic functional reserve and the severity of liver dysfunction.Although this ratio is diff icult to determine in clinical situations,BCAAs/tyrosine molar concentration ratio(BTR) has been proposed as a simpler substitute.BTR correlates with various liver function examinations,including markers of hepatic f ibrosis,hepatic blood flow and hepatocyte function,and can thus be considered as reflecting the degree of hepatic impairment.This manuscript examines the literature to clarify whether BTR can serve as a prognostic factor for treatment of HCC. 展开更多
关键词 Branched-chain amino acids to tyrosine ratio Fischer's ratio Prognostic factor Hepatocellular carcinoma
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Evolution from Primitive Life to Homo sapiens Based on Visible Genome Structures: The Amino Acid World 被引量:3
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作者 Kenji Sorimachi 《Natural Science》 2009年第2期107-119,共13页
It is not too much to say that molecular biology, including genome research, has progressed based on the determination of nucleotide or amino acid sequences. However, these ap-proaches are limited to the analysis of r... It is not too much to say that molecular biology, including genome research, has progressed based on the determination of nucleotide or amino acid sequences. However, these ap-proaches are limited to the analysis of relatively small numbers of the same genes among spe-cies. On the other hand, by graphical presenta-tion of the ratios of the numbers of amino acids present to the total numbers of amino acids presumed from the target gene(s) or genome or those of the numbers of nucleotides present to the total numbers of nucleotides calculated from the target gene(s) or genome, we can readily draw conclusions from extraordinarily huge data sets integrated by human intelli-gence. 1) Assuming polymerization of amino acids or nucleotides in a simulation analysis based on a random choice, proteins were formed by simple amino acid polymerization, while nucleotide polymerization to form nucleic acids encoding specific proteins needed certain specific control. These results proposed that protein formation chronologically preceded codon formation during the establishment of primitive life forms. In the prebiotic phase, amino acid composition was a dominant factor that determined protein characteristics;the “Amino Acid World”. 2) The genome is constructed homogeneou- sly from putative small units displaying similar codon usages and coding for similar amino acid compositions;the unit is a gene assembly en-coding 3,000 - 7,000 amino acid residues and this unit size is independent not only of genome size, but also of species. 3) In codon evolution, all nucleotide alterna-tions are correlated, not only in coding regions, but also in non-coding regions;the correlations can be expressed by linear formulas;y = ax + b, where “y” and “x” represent nucleotide con-tents, and “a” and “b” are constant. 4) The basic pattern of cellular amino acid compositions obtained from whole cell lysates is conserved from bacteria to Homo sapiens, and resembles that calculated from complete genomes. This basic pattern is characterized by a “star-shape” that changes slightly among species, and changes in amino acid composi-tion seem to reflect biological evolution. 5) Organisms can essentially be classified according to two codon patterns. Biological evolution due to nucleotide sub-stitutions can be expressed by simple linear formulas based on mathematical principles, while natural selection must affect species pre- servation after nucleotide alternations. There-fore, although Darwin’s natural selection is not directly involved in nucleotide alternations, it contributes obviously to the selection of nu-cleotide alternations. Thus, Darwin’s natural selection is doubtless an important factor in biological evolution. 展开更多
关键词 EVOLUTION PRIMITIVE LIFE Form Genome NUCLEOTIDE Content Chargaff’s PARITY Rules CODON amino acids Linear Formula Classification
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Effect of Dehulling and Hydrothermal Treatment on the Amino Acid Content of Soriz (<i>Sorghum oryzoidum</i>) 被引量:1
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作者 Rodica Siminiuc Lidia Coșciug 《Food and Nutrition Sciences》 2021年第12期1232-1242,共11页
Cereals are the basic element in ensuring the food security of the population through the significant intake of carbohydrates, proteins, dietary fiber, vitamins and minerals. The processing of cereals leads to changes... Cereals are the basic element in ensuring the food security of the population through the significant intake of carbohydrates, proteins, dietary fiber, vitamins and minerals. The processing of cereals leads to changes in their nutritional quality, which could lead to both reduced nutrients and anti-nutrients. Gluten-free cereal varieties attract attention as raw materials to improve the nutritional quality of food and to diversify the product range. Sorghum (<i>Sorghum</i><span> <i>oryzoidum</i></span>) is a hybrid of sorghum, obtained at the Institute for Scientific Research for Corn and Sorghum in the Republic of Moldova, by crossing Sudan grass (<i>S</i><span>. <i>sudanense</i></span>) and bicolor sorghum (<i>S</i><span>. <i>bicolor</i></span>). The research aimed to determine the impact of dehulling and hydrothermal treatment on the amino acid content of soriz. The obtained results reported that the dehulling and hydrothermal treatment led to the uneven modification of the amino acid content in the investigated samples. As a result of dehulling, the total amount of essential amino acids decreased by 19.8% compared to the native grain. Boiling whole grains without prior hydration led to <span>34% loss of essential amino acids compared to native grains, and pre-hydration</span> of the grains and subsequent boiling reduced essential amino acid losses by 8% compared to cooked grains without hydration. Boiling grains with pre-hydration had a positive effect on the chemical index of lysine, methionine and cysteine, leucine and tryptophan. However, the nutritional quality of sorghum grain proteins and derivatives obtained, evaluated according to the chemical index, is low. The results obtained reported that dehulling and hydrothermal treatment unevenly altered the amino acid content, and the method of boiling grains with pre-hydration had a positive effect on the CSI of lysine, methionine and cysteine, leucine and tryptophan. 展开更多
关键词 soriz DEHULLING Hydrothermal Treatment amino acids Chemical score Index
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DCHA AS A NEW REAGENT FOR THE ESTERIFICATION OF OBSTINATED AMINO ACIDS BY THE MERRIFIELD'S RESIN 被引量:1
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作者 De Xin WANG Gui Shen LU (Institute of Materia Medica,Chinese Academy of Medical Sciences,Beijing 100050) 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第4期289-290,共2页
The obstinated amino acid,Boc-Asn(or Boc-Gln),was directly anchored onto the Merrifield's resin using DCHA as the base in present reaction.The yield(71.88%)of Boc-Asn-OCH_2-resin was much better than those(0-33.5%... The obstinated amino acid,Boc-Asn(or Boc-Gln),was directly anchored onto the Merrifield's resin using DCHA as the base in present reaction.The yield(71.88%)of Boc-Asn-OCH_2-resin was much better than those(0-33.5%)using Cs_2CO_3,KOH,KF.DEA and TEA as the base.which are efficient reagents for other amino acids in the same reaction. 展开更多
关键词 DEA TEA GLN DCHA As A NEW REAGENT FOR THE EsTERIFICATION OF OBsTINATED amino acids BY THE MERRIFIELD’s REsIN As
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Effectiveness of an amino acid beverage formulation in diarrheapredominant irritable bowel syndrome:A pragmatic real-world study 被引量:1
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作者 Samantha E Niles Phil Blazy +5 位作者 Samuel N Cheuvront Robert W Kenefick Sadasivan Vidyasagar Adam BSmith Neil Fawkes William Denman 《World Journal of Gastrointestinal Pharmacology and Therapeutics》 2023年第5期39-49,共11页
BACKGROUND Amino-acid based medical foods have shown promise in alleviating symptoms of drug induced gastrointestinal side effects;particularly,diarrhea-predominant symptoms.Irritable bowel syndrome(IBS)is a gastroint... BACKGROUND Amino-acid based medical foods have shown promise in alleviating symptoms of drug induced gastrointestinal side effects;particularly,diarrhea-predominant symptoms.Irritable bowel syndrome(IBS)is a gastrointestinal disorder that affects up to 9% of people globally,with diarrhea predominant IBS(IBS-D)being the most prevalent subtype.Further trials are needed to explore potential added benefits when integrated into standard care for IBS-D.AIM To assess the effectiveness of an amino acid-based medical food as an adjunct to standard of care for adults with IBS-D.METHODS This is a pragmatic,real world,open label,single arm study comparing a 2-week baseline assessment to a 2-week intervention period.One hundred adults,aged 18 to 65 years,with IBS-D,according to Rome IV criteria,were enrolled after completing a 2-week baseline assessment period and received a 2-week supply of an amino acid based medical food which was consumed at home twice daily on top of their standard of care.The primary outcome was an assessment of tolerability after 2-weeks of consumption,while secondary outcomes included changes in stool consistency(Bristol Stool Form Scale),severity of abdominal pain&discomfort,symptoms of urgency,Global Improvement Survey(GIS),and the IBS severity scoring system(IBS-SSS).RESULTS The test product was well-tolerated as each participant successfully completed the full 14-day trial,and there were no instances of dropouts or discontinuation of the study product reported.Forty percent of participants achieved a 50% or more reduction in the number of days with type 6-7 bowel movements(IBS-D stool consistency responders).Fifty-three percent of participants achieved a clinically meaningful reduction of 30% in mean weekly pain scores,and 55%experienced the same for mean weekly discomfort scores(IBS-D pain and discomfort responders).Participants experienced a mean-109.4(95% confidence interval:-130.1,-88.8)point reduction on the IBS-SSS and 52% experienced a minimally clinically important difference of>95 points.An IBS-SSS category shift from severe to moderate or mild occurred in 69% of participants.For functional symptoms,76% of participants reported symptom relief on the GIS.CONCLUSION The amino acid-based medical food was well-tolerated,when added to the standard of care,and demonstrated improvements in both overall IBS symptom severity and IBS-D symptoms within just 2 wk. 展开更多
关键词 Diarrhea-predominant irritable bowel syndrome amino acid beverage formulation Pragmatic real-world study Medical food Bristol stool Form scale Irritable Bowel syndrome–severity scoring system
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Recent progress in the applications of presynaptic dopaminergic positron emission tomography imaging in parkinsonism
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作者 Yujie Yang Xinyi Li +7 位作者 Jiaying Lu Jingjie Ge Mingjia Chen Ruixin Yao Mei Tian Jian Wang Fengtao Liu Chuantao Zuo 《Neural Regeneration Research》 SCIE CAS 2025年第1期93-106,共14页
Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.... Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders. 展开更多
关键词 aromatic amino acid decarboxylase brain imaging dopamine transporter Parkinson’s disease PARKINsONIsM positron emission tomography presynaptic dopaminergic function vesicle monoamine transporter type 2
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Free amino acid content in trunk,branches and branchlets of Araucaria angustifolia(Araucariaceae)
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作者 Crizane Hackbarth Patricia Soffiatti +3 位作者 Fla′vio Zanette Eny Iochevet Segal Floh Amanda Ferreira Macedo Henrique Aparecido Laureano 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第6期1489-1496,共8页
Araucaria angustifolia(Bertol.) O. Kuntze exhibits dimorphism in its stem structure, where the trunk is orthotropic and branches and branchlets(primary and secondary branches) are plagiotropic. These stems exhibit dif... Araucaria angustifolia(Bertol.) O. Kuntze exhibits dimorphism in its stem structure, where the trunk is orthotropic and branches and branchlets(primary and secondary branches) are plagiotropic. These stems exhibit different behavior when used for vegetative propagation,and only segments of trunk can form a complete plant. The physiological and biochemical mechanisms that characterize these stems are still little known. The aim of this study was to describe the free amino acid profiles in trunks,branches, and branchlets of A. angustifolia. Segments of 5 cm in length were excised from young individuals below the stem apex. The needles were removed and samples were frozen and lyophilized. The determinations were made by high-performance liquid chromatography, and the results were expressed as lg/g fresh weight(FW). The trunks and branches had the highest content of total amino acids, which were 112.23 ± 20.57 lg/g FW and 111.97 ± 27.78 lg/g FW, respectively. The amino acids—glutamine, aspartate and c-aminobutyric acid and tyrosine—were noticeably higher in the three types of stems.In the trunk, a higher amount of asparagine and tryptophan,was also detected. Glutamic acid and glutamine were found in higher quantities in the branches. The branchlets had very low total amino acid content (30.79 ± 4.19 lg/g FW), wherein asparagine is the only amino acid not detected. Thus, it was observed that the profile of the free amino acid differs among trunks, branches, and branchlets in A. angustifolia, indicating that they perform different functions. 展开更多
关键词 Brazilian pine Physiological mechanisms stem’s dimorphism Free amino acids
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Synthesis,Characterization and Structure of Chiral Amino Acids and Their Corresponding Amino Alcohols with Camphoric Backbone
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作者 QIAN Hui-Fen HUANG Wei +1 位作者 LI Hui-Hui YAO Cheng 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第10期1243-1249,共7页
Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-(+)-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among t... Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-(+)-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among them, one intermediate (1S,3R)-3-amino-2,2,3- trimethyl cyclopentane-1-carboxylic acid hydrochloride 3 was structurally elucidated by X-ray diffraction techniques. Versatile intermolecular hydrogen bonding interactions observed in its packing structure result in a two-dimensional framework. 展开更多
关键词 chiral amino acids and amino alcohols (1s 3R)-3-amino-2 2 3-trimethyl-cyclopentane-1-carboxylic acid hydrochloride hydrogen-bonding interactions crystal structures
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Natural selection in vertebrate evolution under genomic and biosphere biases based on amino acid content: Primitive vertebrate hagfish (<i>Eptatretus burgeri</i>)
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作者 Kenji Sorimachi Teiji Okayasu +2 位作者 Shuji Ohhira Nobuhide Masawa Ichio Fukasawa 《Natural Science》 2013年第2期221-227,共7页
Cluster analyses using the amino acid content predicted from the coding regions (13 genes) of complete vertebrate mitochondrial genomes as traits grouped selected vertebrates into two clusters, terrestrial and aquatic... Cluster analyses using the amino acid content predicted from the coding regions (13 genes) of complete vertebrate mitochondrial genomes as traits grouped selected vertebrates into two clusters, terrestrial and aquatic vertebrates. Exceptions were the hagfish (Eptatretus burgeri), thought to be an early ancestor of vertebrates, and the black spotted frog (Rana nigromaculata), which is terrestrial as an adult and aquatic as a larva. These two species fall into the terrestrial and aquatic clusters, respectively. Using the nucleotide (G, C, T and A) content in the coding and non-coding regions, and in the complete genome as traits, similar results were obtained but with some additional exceptions. In addition, phylogenetic analyses of 16S rRNA sequences produced a consistent result. The results of this study indicated that vertebrate evolution is controlled by natural selection under both an internal bias as a result of nucleotide replacement genomic rules, and an external bias caused by environmental biospheric conditions. 展开更多
关键词 Natural selection VERTEBRATE Evolution Complete Mitochondrial Genome amino acid Composition 16s rRNA Hagfish (Eptatretus burgeri)
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Rapid, accurate and serotype independent pipeline for in silico epitope mapping of SARS-CoV-2 antigens: a combined machine learning and Chou’s pseudo amino acid composition method
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作者 Arash Rahmani Mokhtar Nosrati 《Medical Data Mining》 2023年第3期1-9,共9页
Here,a new integrated machine learning and Chou’s pseudo amino acid composition method has been proposed for in silico epitope mapping of severe acute respiratorysyndrome-like coronavirus antigens.For this,a training... Here,a new integrated machine learning and Chou’s pseudo amino acid composition method has been proposed for in silico epitope mapping of severe acute respiratorysyndrome-like coronavirus antigens.For this,a training dataset including 266 linear B-cell epitopes,1,267 T-cell epitopes and 1,280 non-epitopes were prepared.The epitope sequences were then converted to numerical vectors using Chou’s pseudo amino acid composition method.The vectors were then introduced to the support vector machine,random forest,artificial neural network,and K-nearest neighbor algorithms for the classification process.The algorithm with the highest performance was selected for the epitope mapping procedure.Based on the obtained results,the random forest algorithm was the most accurate classifier with an accuracy of 0.934 followed by K-nearest neighbor,artificial neural network,and support vector machine respectively.Furthermore,the efficacies of predicted epitopes by the trained random forest algorithm were assessed through their antigenicity potential as well as affinity to human B cell receptor and MHC-I/II alleles using the VaxiJen score and molecular docking,respectively.It was also clear that the predicted epitopes especially the B-cell epitopes had high antigenicity potentials and good affinities to the protein targets.According to the results,the suggested method can be considered for developing specific epitope predictor software as well as an accelerator pipeline for designing serotype independent vaccine against the virus. 展开更多
关键词 severe acute respiratory syndrome-like coronavirus machine learning Chou’s pseudo amino acid composition epitope based vaccine
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Therapeutic effects of Lingguizhugan decoction in a rat model of high-fat diet-induced insulin resistance
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作者 Xiao-Ming Liu Shi-Qing Yuan +4 位作者 Ying Ning Shi-Jia Nie Xu-Qiong Wang Hong-Yi Jia Xiu-Li Zheng 《World Journal of Diabetes》 SCIE 2024年第6期1291-1298,共8页
BACKGROUND Lingguizhugan(LGZG)decoction is a widely used classic Chinese medicine formula that was recently shown to improve high-fat diet(HFD)-induced insulin resistance(IR)in animal studies.AIM To assess the therape... BACKGROUND Lingguizhugan(LGZG)decoction is a widely used classic Chinese medicine formula that was recently shown to improve high-fat diet(HFD)-induced insulin resistance(IR)in animal studies.AIM To assess the therapeutic effect of LGZG decoction on HFD-induced IR and explore the potential underlying mechanism.METHODS To establish an IR rat model,a 12-wk HFD was administered,followed by a 4-wk treatment with LGZG.The determination of IR status was achieved through the use of biochemical tests and oral glucose tolerance tests.Using a targeted metabolomics platform to analyze changes in serum metabolites,quantitative real-time PCR(qRT-PCR)was used to assess the gene expression of the ribosomal protein S6 kinase beta 1(S6K1).RESULTS In IR rats,LGZG decreased body weight and indices of hepatic steatosis.It effectively controlled blood glucose and food intake while protecting islet cells.Metabolite analysis revealed significant differences between the HFD and HFDLGZG groups.LGZG intervention reduced branched-chain amino acid levels.Levels of IR-related metabolites such as tryptophan,alanine,taurine,and asparagine decreased significantly.IR may be linked to amino acids due to the contemporaneous increase in S6K1 expression,as shown by qRT-PCR.CONCLUSIONS Our study strongly suggests that LGZG decoction reduces HFD-induced IR.LGZG may activate S6K1 via metabolic pathways.These findings lay the groundwork for the potential of LGZG as an IR treatment. 展开更多
关键词 Lingguizhugan decoction High-fat diet-induced insulin resistance amino acid metabolism s6K1
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七氟醚不同麻醉深度对术后应激反应以及血清兴奋性氨基酸、S-100β、NSE含量的影响 被引量:10
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作者 蔡云亮 李安学 +2 位作者 李文兵 朱红 黄静 《海南医学院学报》 CAS 2015年第3期393-396,共4页
目的:研究七氟醚不同麻醉深度对术后应激反应以及血清兴奋性氨基酸、S-100β、神经元特异性烯醇化酶(NSE)含量的影响。方法:将2013年4月-2014年5月期间在我院接受静吸复合麻醉的120例患者纳入研究,根据七氟醚麻醉深度不同分为两组,... 目的:研究七氟醚不同麻醉深度对术后应激反应以及血清兴奋性氨基酸、S-100β、神经元特异性烯醇化酶(NSE)含量的影响。方法:将2013年4月-2014年5月期间在我院接受静吸复合麻醉的120例患者纳入研究,根据七氟醚麻醉深度不同分为两组,观察组患者接受高浓度七氟醚麻醉[脑电双频指数(BIS)值35-45]、对照组患者接受低浓度七氟醚麻醉(BIS值50-60),比较两组患者的术后应激反应以及血清兴奋性氨基酸、S-100β、NSE含量。结果:(1)应激反应:观察组患者的血清皮质醇(Cor)、去甲肾上腺素(NE)、肾上腺素(E)含量低于对照组(P〈0.05);(2)兴奋性氨基酸:观察组患者的血清谷氨酸(Glu)、天冬氨酸(Asp)、甘氨酸(Gly)含量低于对照组(P〈0.05);(3)血清生化指标:观察组患者的血清S-100β、NSE含量低于对照组(P〈0.05)。结论:高浓度七氟醚麻醉(BIS值35-45)有助于缓解术后应激反应、减少神经细胞损伤、降低血清兴奋性氨基酸含量、S-100β、NSE含量,是更为理想的七氟醚麻醉深度。 展开更多
关键词 七氟醚 术后认知功能障碍 应激 兴奋性氨基酸 神经元特异性烯醇化酶 s-100β蛋白
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大连地区无偿献血者隐匿性乙型肝炎病毒感染pre-S/S区基因分析 被引量:19
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作者 王东 邓雪莲 +4 位作者 周璐 方琳琳 宋浏伟 袁权 安万新 《中国输血杂志》 CAS 北大核心 2015年第1期26-31,共6页
目的了解大连地区无偿献血者隐匿性肝炎乙型病毒感染(OBI)的情况和pre-S/S区基因的变异情况。方法对大连市血液中心2010年12月2日-2013年5月31日的无偿献血者血液标本进行常规ELISA(HBs Ag、抗-HCV、抗-HIV和抗-TP)和HIV/HBV/HCV联合NA... 目的了解大连地区无偿献血者隐匿性肝炎乙型病毒感染(OBI)的情况和pre-S/S区基因的变异情况。方法对大连市血液中心2010年12月2日-2013年5月31日的无偿献血者血液标本进行常规ELISA(HBs Ag、抗-HCV、抗-HIV和抗-TP)和HIV/HBV/HCV联合NAT筛查,对于单独核酸检测反应性的献血者加以跟踪或回溯,结合乙型肝炎血清学标志物的试验、鉴别试验、病毒定量试验和半巢式PCR来确定OBI,同时对OBI的pre-S/S区基因序列与对照组(HBs Ag+序列,Genbank)做比对分析。结果共筛查158 232份血液标本,确定了其中的69份OBI,流行率为1∶2 293(69/158 232)。41例OBI获得pre-S/S区基因序列:B型6例、C型34例、D型1例;与对照组相比,OBI在S区的氨基酸序列的变异明显(PB=0.013;PC=0.003),主要变异位点为B型的V14G/A、Y161F/S、V168A、P217L和C型的E2G/A/V、T118R/K/A/M、P127T/L/H/S、E164D/G、L175S、S174N。结论大连地区献血者OBI在HBV基因组S区的氨基酸序列存在多个位点的变异,这些变异与OBI的产生存在某种关系,且这种关系受基因型的影响。 展开更多
关键词 隐匿性乙型肝炎病毒感染(OBI) pre-s/s区基因 氨基酸序列变异 乙型肝炎病毒 无偿献血者 大连
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一种新的氨基酸描述子及其在肽QSAR中的应用 被引量:25
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作者 梅虎 周原 +1 位作者 孙立力 李志良 《物理化学学报》 SCIE CAS CSCD 北大核心 2004年第8期821-825,共5页
从天然氨基酸的25个结构与拓扑变量中经主成分分析得到一种新的氨基酸描述子———VSTV(principalcomponentscoresvectorofstructuralandtopologicalvariables).应用该描述子对以下3个体系,即血管紧张素转化酶抑制剂(2肽)、抗菌18肽和... 从天然氨基酸的25个结构与拓扑变量中经主成分分析得到一种新的氨基酸描述子———VSTV(principalcomponentscoresvectorofstructuralandtopologicalvariables).应用该描述子对以下3个体系,即血管紧张素转化酶抑制剂(2肽)、抗菌18肽和促凝血酶原激酶抑制剂(6~12肽)进行分子结构参数化表达,并在此基础上通过偏最小二乘回归(PLSR)建立定量构效关系(QSAR)模型,取得了优于文献的结果.模型的复相关系数(R2)和交互检验复相关系数(Q2)分别为0.789,0.767;0.996,0.879;0.981,0.480. 展开更多
关键词 氨基酸 多肽 拓扑 VsTV 定量构效关系 偏最小二乘回归
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人胎盘谷胱甘肽S-转移酶的纯化和性质 被引量:5
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作者 李春海 张凯 +1 位作者 谭子兴 陈毓兰 《生物化学杂志》 CSCD 1991年第2期135-141,共7页
将人胎盘组织粗匀浆经105000×g超速离心后,用S-已基谷胱甘肽-琼脂糖-6B亲和层析一步纯化法获得电泳纯的人胎盘GST(简称GST-π)。其比活性较粗匀浆高194.7倍,回收率为50%。再经DE_(52)交换柱进一步纯化,用KCl浓度梯度洗脱后为单一... 将人胎盘组织粗匀浆经105000×g超速离心后,用S-已基谷胱甘肽-琼脂糖-6B亲和层析一步纯化法获得电泳纯的人胎盘GST(简称GST-π)。其比活性较粗匀浆高194.7倍,回收率为50%。再经DE_(52)交换柱进一步纯化,用KCl浓度梯度洗脱后为单一锐峰,等电聚集电泳呈一条带,等电点(pI)为4.60。GST-π经TSKgel-G3000SW柱高效液相层析,也为单一对称锐峰,测得其分子量为45.2kD;在SDS-PAGE电泳也为单一区带,测得其亚基单位的分子量为22.5kD。GST-π氨基酸组成分析可检出十六种氨基酸,其中以谷氨酸、亮氨酸、丙氨酸、天冬氨酸及甘氨酸含量较高。 GST-π酶动力学研究证明GST-π以GST和CDNB为底物时km值分别为0.16mmol/L和0.55mmol/L,经测定表明,GST-π的最适作用pH值为7.5,在pH6.5—9的范围内较为稳定,体外GST-π在温度超过25℃对容易失活。以GST-π为抗原,得到兔抗人GST-π抗血清,其效价为1:32,与人肝GSTs不发生免疫交叉反应。 展开更多
关键词 胎盘 谷胱甘肽 s-转移酶 GsTs
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牛视网膜S抗原和IRBP的氨基酸分析
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作者 杨培增 李绍珍 +5 位作者 潘苏华 曹心嫄 谢楚芳 梁舜薇 黄祥坤 毛文书 《眼科学报》 1993年第4期203-207,共5页
我们用离子交换层析和亲和层析的方法提纯了视网膜S抗原和光感受器间维生素A类结合蛋白(interphotoreceptor retinoid—bindingprotein,IRBP),分析了它们的氨基酸组成及其含量,发现绝大多数氨基酸含量与国外报道的结果相似,对个别氨基... 我们用离子交换层析和亲和层析的方法提纯了视网膜S抗原和光感受器间维生素A类结合蛋白(interphotoreceptor retinoid—bindingprotein,IRBP),分析了它们的氨基酸组成及其含量,发现绝大多数氨基酸含量与国外报道的结果相似,对个别氨基酸含量出现较大差别的可能原因及有关问题进行了讨论. 展开更多
关键词 s抗原 维生素A类 结合蛋白 氨基酸 葡萄膜炎
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立体选择性合成(S,S)-2-羟基-3-氨基-4-苯基丁酸
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作者 肖敏 吴筱屏 +4 位作者 梁本熹 长谷川Y 松本S 村松Y 李志良 《化学试剂》 CAS CSCD 北大核心 1996年第6期324-326,336,共4页
研究了药物及其中间体的立体选择性合成。报道了一种抗艾滋病候选药中间体(S,S)-2-羟基-3-氨基-4-笨基丁酸的立体选择性合成方法,显著地提高了S-型产物的收率。
关键词 药物立体选择性 羟基氨基酸 抗艾滋病药
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具有C_2-对称的新型手性双-S-2-(咪唑-1-基)脂肪酰二胺的合成
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作者 郭生金 罗奎 +1 位作者 兰静波 谢如刚 《山西农业大学学报(自然科学版)》 CAS 2007年第1期96-98,102,共4页
以L-氨基酸为手性源,合成了多种具有C2-对称的手性双-S-2-(咪唑-1-基)脂肪酰二胺并且进行了结构表征。在碱性条件下,L-氨基酸和乙二醛、甲醛经过缩合反应生成了(S)-2-(咪唑-1-基)羧酸钠,与甲醇作用转化为甲酯后继与二胺进行胺解反应制... 以L-氨基酸为手性源,合成了多种具有C2-对称的手性双-S-2-(咪唑-1-基)脂肪酰二胺并且进行了结构表征。在碱性条件下,L-氨基酸和乙二醛、甲醛经过缩合反应生成了(S)-2-(咪唑-1-基)羧酸钠,与甲醇作用转化为甲酯后继与二胺进行胺解反应制得目标分子。这些化合物可进一步合成新型手性咪唑鎓环蕃或进行配位络合、分子识别等研究。 展开更多
关键词 天然氨基酸 双-s-2-(咪哇-1-基)脂肪酰胺 咪唑衍生物 合成
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(S)-N-保护的2-氨基-3-(二乙氧膦酰基)丙酸乙酯的合成
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作者 王昊 王美怡 洪伟 《广州化工》 CAS 2013年第17期6-7,共2页
(S)-N-保护的2-氨基-3-(二乙氧膦酰基)丙酸乙酯是用于制备L-2-氨基-3-膦酰基丙酸的重要中间体。报道了立体选择性合成(S)-N-保护的2-氨基-3-(二乙氧膦酰基)丙酸乙酯的方法,以N-保护的L-丝氨酸为原料,经Mitsunobu反应和亲核加成反应的两... (S)-N-保护的2-氨基-3-(二乙氧膦酰基)丙酸乙酯是用于制备L-2-氨基-3-膦酰基丙酸的重要中间体。报道了立体选择性合成(S)-N-保护的2-氨基-3-(二乙氧膦酰基)丙酸乙酯的方法,以N-保护的L-丝氨酸为原料,经Mitsunobu反应和亲核加成反应的两步反应制得,其结构经1H NMR和13C NMR表征。 展开更多
关键词 (s)-N-保护的2-氨基-3-(二乙氧膦酰基)丙酸乙酯 L-2-氨基-3-膦酰基丙酸 合成
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