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排序方式: 共有467条查询结果,搜索用时 15 毫秒
1.
Aurel Popa Wagner Eugenia Psarrou Lieselotte Popa Wagner 《Analytical biochemistry》1983,129(2):326-328
A simple and sensitive high-performance liquid chromatography method with electrochemical detector is described for the determination of free 3-methoxy-4-hydroxyphenylacetic acid (HVA) in human plasma. The method does not involve any extraction, is specific and reproducible, and has the potential to measure serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) simultaneously. The plasma concentration of free HVA in eight normal, healthy adult volunteers was 10.9 ± 4.6 (mean ± SD). In a preliminary study, in one schizophrenic patient the plasma HVA increased twofold after neuroleptic treatment. 相似文献
2.
Distinct effects of climate warming on populations of silver fir (Abies alba) across Europe
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3.
Bioactive polymers XXX. Immobilization of invertase on the diazonium salt of 4-aminobenzoylcellulose
Invertase was immobilized on diazotized 4-aminobenzoylcellulose. The optimum coupling conditions, namely enzyme concentration, time, and pH, were determined. The temperature and pH value for the maximum activity of the immobilized enzyme were determined and the apparent Michaelis constant was estimated. 相似文献
4.
Adrian Bogdan Tigu Catalin Sorin Constantinescu Patric Teodorescu David Kegyes Raluca Munteanu Richard Feder Mareike Peters Ioana Pralea Cristina Iuga Diana Cenariu Andra Marcu Alina Tanase Anca Colita Rares Drula Jon Thor Bergthorsson Victor Greiff Delia Dima Cristina Selicean Ioana Rus Mihnea Zdrenghea Diana Gulei Gabriel Ghiaur Ciprian Tomuleasa 《Journal of cellular and molecular medicine》2023,27(19):2864-2875
Acute megakaryoblastic leukaemia (AMkL) is a rare subtype of acute myeloid leukaemia (AML) representing 5% of all reported cases, and frequently diagnosed in children with Down syndrome. Patients diagnosed with AMkL have low overall survival and have poor outcome to treatment, thus novel therapies such as CAR T cell therapy could represent an alternative in treating AMkL. We investigated the effect of a new CAR T cell which targets CD41, a specific surface antigen for M7-AMkL, against an in vitro model for AMkL, DAMI Luc2 cell line. The performed flow cytometry evaluation highlighted a percentage of 93.8% CAR T cells eGFP-positive and a limited acute effect on lowering the target cell population. However, the interaction between effector and target (E:T) cells, at a low ratio, lowered the cell membrane integrity, and reduced the M7-AMkL cell population after 24 h of co-culture, while the cytotoxic effect was not significant in groups with higher E:T ratio. Our findings suggest that the anti-CD41 CAR T cells are efficient for a limited time spawn and the cytotoxic effect is visible in all experimental groups with low E:T ratio. 相似文献
5.
A case of a laryngeal extensive carcinoma determining a severe obstruction is reported, where the development of a monstrous adenopathy is followed by the regression of the initial tumour until complete laryngoscopical disappearance, as well as of obstructive and general symptoms. Cytological and histological examinations of the above-mentioned lymph node demonstrated (besides metastatic cells) a peculiar cellular reaction, similar to rhinoscleroma, which represented an original anti-carcinoma defensive mode. The medical importance of this very rare case is discussed and the probable immune origin of this reactive cellular complex is explained by analogy with "Hodgkinom", where granuloma are the immune response of the body against Sternberg-Reed cell. 相似文献
6.
The precipitation of iron sulfides potentially offers enough energy and reducing power to sustain life but organisms harnessing this reaction have not to our knowledge been previously described. We isolated a bacterial strain, capable of forming the iron sulfide minerals troilite (FeS), greigite (Fe3S4), and pyrite (FeS2), from subsurface, microbial mats in Mangalia, Romania. This strain, most closely related to strains of Thiomonas sp., forms pyrite only if the redox conditions remain negative (< ?60 mV), sulfides are provided continually (≈1 mM), and the concentration of iron remains low (≤ 0.08 mM) but constant. Pyrite formation by this microbial strain is proposed as an example of biologically controlled mineralization because it is controlled by uncouplers of oxidative phosphorylation, it is larger in living than in dead cells, it is additive (controlled less by the amount of cell surfaces and more by reagents), and it results in the formation of ATP. This study indicates that precipitation and crystal formation can represent an energy resource for life and provides support for the “iron-sulfide world hypothesis” regarding the early evolution of life on Earth. 相似文献
7.
Valentin Popa Louis Morneau Céline Piché André Deshaies Eric Bauce Claude Guertin 《ZooKeys》2013,(348):97-124
Twig beetles in the genus Pityophthorus Eichhoff, 1864 include more than 300 species worldwide, with maximum diversity in tropical and subtropical regions. To date, approximately 50 species of Pityophthorus have been recorded in Canada, and these species are associated mainly with coniferous trees. Since 1981, no comprehensive study on this difficult taxonomic group has been conducted in Quebec, Canada, most likely due to their limited significance as forest pests. Based on data gathered from five years of field sampling in conifer seed orchards and compiled from various entomological collections, the distribution of Pityophthorus species in Quebec is presented. Approximately 291 new localities were recorded for the Pityophthorus species. Five species-group taxa, namely Pityophthorus puberulus (LeConte, 1868), Pityophthorus pulchellus pulchellus Eichhoff, 1869, Pityophthorus pulicarius (Zimmermann, 1868), Pityophthorus nitidus Swaine, 1917,and Pityophthorus cariniceps LeConte&Horn, 1876 were the most widespread. In contrast, Pityophthorus consimilis LeConte, 1878, Pityophthorus intextus Swaine, 1917, Pityophthorus dentifrons Blackman, 1922, Pityophthorus ramiperda Swaine, 1917, and Pityophthorus concavus Blackman, 1928 display a notably limited distribution. In addition, the first distribution records of Pityophthorus intextus and Pityophthorus biovalis Blackman, 1922 are furnished, and the subspecies Pityophthorus murrayanae murrayanae Blackman, 1922is reported from Quebec for the second time. Moreover, distribution maps are provided for all Pityophthorus species recorded in the province of Quebec. 相似文献
8.
Ludmila Aricov Daniel George Angelescu Adriana Băran Vlad Tudor Popa Aurica Precupaş 《Journal of biomolecular structure & dynamics》2020,38(9):2659-2671
AbstractThe binding of drugs to serum proteins is governed by weak non-covalent forces. In this study, the nature and magnitude of the interactions between piroxicam (PRX) and bovine serum albumin (BSA) was assessed using spectroscopic, calorimetric and computational molecular methods. The fluorescence data revealed an atypical behavior during PRX and BSA interaction. The quenching process of tryptophan (Trp) by PRX is a dual one (approximately equal static and dynamic quenched components). The FRET results indicate that a non-radiative transfer of energy occurred. The association constant and the number of binding sites indicate moderate PRX and BSA binding. The competitive binding study indicates that PRX is bound to site I from the hydrophobic pocket of subdomain IIA of BSA. The synchronous spectra showed that the microenvironment around the BSA fluorophores and protein conformation do not change considerably. The Trp lifetimes revealed that PRX mainly quenches the fluorescence of Trp-213 situated in the hydrophobic domain. The CD and DSC investigation show that addition of PRX stabilizes the protein structure. ITC results revealed that BSA-PRX binding involves a combination of electrostatic, hydrophobic and hydrogen interactions. The analysis of the computational data is consistent with the experimental results. This thorough investigation of the PRX-BSA binding may provide support for other studies concerning moderate affinity drugs with serum protein.Communicated by Ramaswamy H. Sarma 相似文献
9.
Christoforos A. Hadjistasi Ioannis J. Stavrou Raluca‐Ioana Stefan‐Van Staden Hassan Y. Aboul‐Enein Constantina P. Kapnissi‐Christodoulou 《Chirality》2013,25(9):556-560
In this study, simple electrophoretic methods were developed for the chiral separation of the clinically important compounds fucose and pipecolic acid. In recent years, these analytes, and particularly their individual enantiomers, have attracted considerable attention due to their role in biological functions and disorders. The detectability and sensitivity of pipecolic acid and fucose were improved by reacting them with fluorenylmethyloxycarbonyl chloride (FMOC‐Cl) and 5‐amino‐2‐naphthalene‐sulfonic acid (ANSA), respectively. The enantioseparation conditions were optimized by initially investigating the type of the chiral selector. Different chiral selectors, such as polymeric surfactants and cyclodextrins, were used and the most effective ones were determined with regard to resolution and analysis time. A 10‐mM β‐cyclodextrin was able to separate the enantiomers of ANSA‐DL‐fucose and the polymeric surfactant poly(sodium N‐undecanoyl‐LL‐leucine‐valinate) was able to separate the enantiomers of FMOC‐DL‐pipecolic acid, with resolution values of 3.45 and 2.78, respectively. Additional parameters, such as the concentration and the pH of the background electrolyte (BGE), the concentration of the chiral selector, and the addition of modifiers were examined in order to optimize the separations. The addition of the chiral ionic liquid D‐alanine tert‐butyl ester lactate into the BGE was also investigated, for the first time, in order to improve resolution of the enantiomers. Chirality 25:556–560, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
10.
N-(2-aminoethyl)-2-acetamidyl gellan gum (GCM-EDA) was prepared by carboxymethylation (via nucleophilic substitution of primary hydroxyl groups of the β-d-glucose unit of gellan gum, in the presence of alkali and chloroacetic acid) and reaction with tert-butyl N-(2-aminoethyl) carbamate (N-Boc-EDA) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as an activator, followed by deprotection with trifluoroacetic acid. The structural confirmation and characterization of N-(2-aminoethyl)-2-acetamidyl gellan gum was performed by spectroscopic, rheological and thermogravimetric analysis, and in vitro tests showed a lack of cytotoxicity which is indicative of the potential of this material to be used in biomedical applications. 相似文献