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排序方式: 共有163条查询结果,搜索用时 15 毫秒
1.
Biological Trace Element Research - The ko-standardization method is suitable for routine multielement determinations by reactor neutron activation analysis (NAA). Investigation of NIST standard... 相似文献
2.
Momčilo Mihailović Paul Lindberg Ivan Jovanović Duŝan Antić 《Biological trace element research》1992,33(1-3):71-77
The selenium (Se) contents in common cereals in endemic and nonendemic areas in Serbia are very low. Plasma Se levels of both
patients and healthy subjects, were also low, reflecting low Se intakes. Patients with Balkan endemic nephropathy (BEN) had
significantly lower (p<0.05) plasma Se levels than healthy individuals, both from regions close to endemic areas, and from Belgrade. Mean plasma
Se of BEN patients was slightly but insignificantly higher in samples taken immediately after dialysis than in those taken
before, suggesting that very little of the Se present in plasma is dialyzable. Plasma SeGSH-Px activities before and after
hemodialysis in both BEN and Nonendemic chronic renal failure (NCRF) patients were not significantly different, but BEN patients
had lower enzyme activities than those with NCRF and healthy controls. In BEN patients, a significant correlation between
plasma Se and SeGSH-Px activity was found.
NCFR patients were with diagnoses: TBC of kidneys, chronic glomerulonephritis, chronic pyelonephritis, and polycystic kidneys. 相似文献
3.
Geographically Related Variation in Epicuticular Wax Traits of Pinus nigra Populations from Southern Carpathians and Central Balkans – Taxonomic Considerations
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Zorica S. Mitić Bojan K. Zlatković Snežana Č. Jovanović Gordana S. Stojanović Petar D. Marin 《化学与生物多样性》2016,13(7):931-942
The chemical composition of epicuticular waxes of nine populations from three Pinus nigra J. F. Arnold subspecies (namely subsp. nigra, subsp. banatica (Borbás ) Novák , and subsp. pallasiana (Lamb .) Holmboe ) from Southern Carpathians and central Balkan Peninsula were analyzed using GC/MS and GC/FID chromatography, and multivariate statistical techniques with respect to biogeography and taxonomy. In the needle waxes, four primary alcohols and 14 n‐alkanes ranging from C21 to C33 were identified, and the most abundant compounds were the four odd‐numbered n‐alkanes C27, C25, C23, and C29. Multivariate statistical analyses (CDA and CA) have shown existence of three P. nigra groups and suggested clinal differentiation as a mechanism of genetic variation across a geographic area: the first group consisted of the southernmost populations of subsp. pallasiana from Macedonia, the second consisted of the northernmost subsp. banatica populations from Romania, while all populations in Serbia described as three different subspecies (nigra, banatica, and pallasiana) formed the third group together with subsp. nigra population from Bosnia and Herzegovina. According to simple linear regression, geographic latitude and four bioclimatic parameters were moderately correlated with the contents of epicuticular wax compounds that are important in population discrimination, while stepwise multiple regression showed that latitude participated in most of the regression models for predicting the composition of the epicuticular waxes. These results agree with CDA and CA analysis, and confirmed the possibility of recognition of fine geographic differentiation of the analyzed P. nigra populations. 相似文献
4.
Chemical Composition of Ballota macedonica Vandas and Ballota nigra L. ssp. foetida (Vis.) Hayek Essential Oils – The Chemotaxonomic Approach
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Aleksandra S. Đorđević Olga P. Jovanović Bojan K. Zlatković Gordana S. Stojanović 《化学与生物多样性》2016,13(6):782-788
The essential oils isolated from fresh aerial parts of Ballota macedonica (two populations) and Ballota nigra ssp. foetida were analyzed by GC and GC/MS. Eighty five components were identified in total; 60 components in B. macedonica oil (population from the Former Yugoslav Republic of Macedonia), 34 components in B. macedonica oil (population from the Republic of Serbia), and 33 components in the oil of B. nigra ssp. foetida accounting for 93.9%, 98.4%, and 95.8% of the total oils, respectively. The most abundant components in B. macedonica oils were carotol (13.7 – 52.1%), germacrene D (8.6 – 24.6%), and (E)‐caryophyllene (6.5 – 16.5%), while B. nigra ssp. foetida oil was dominated by (E)‐phytol (56.9%), germacrene D (10.0%), and (E)‐caryophyllene (4.7%). Multivariate statistical analyses (agglomerative hierarchical cluster analysis and principal component analysis) were used to compare and discuss relationships among Ballota species examined so far based on their volatile profiles. The chemical compositions of B. macedonica essential oils are reported for the first time. 相似文献
5.
An approach for the improved immobilization of penicillin G acylase onto macroporous poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) as a potential industrial biocatalyst
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Zorica D. Knežević‐Jugović Milena G. Žuža Sonja M. Jakovetić Andrea B. Stefanović Enis S. Džunuzović Katarina B. Jeremić Slobodan M. Jovanović 《Biotechnology progress》2016,32(1):43-53
The use of penicillin G acylase (PGA) covalently linked to insoluble carrier is expected to produce major advances in pharmaceutical processing industry and the enzyme stability enhancement is still a significant challenge. The objective of this study was to improve catalytic performance of the covalently immobilized PGA on a potential industrial carrier, macroporous poly(glycidyl methacrylate‐co‐ethylene glycol dimethacrylate) [poly(GMA‐co‐EGDMA)], by optimizing the copolymerization process and the enzyme attachment procedure. This synthetic copolymer could be a very promising alternative for the development of low‐cost, easy‐to‐prepare, and stable biocatalyst compared to expensive commercially available epoxy carriers such as Eupergit or Sepabeads. The PGA immobilized on poly(GMA‐co‐EGDMA) in the shape of microbeads obtained by suspension copolymerization appeared to have higher activity yield compared to copolymerization in a cast. Optimal conditions for the immobilization of PGA on poly(GMA‐co‐EGDMA) microbeads were 1 mg/mL of PGA in 0.75 mol/L phosphate buffer pH 6.0 at 25°C for 24 h, leading to the active biocatalyst with the specific activity of 252.7 U/g dry beads. Chemical amination of the immobilized PGA could contribute to the enhanced stability of the biocatalyst by inducing secondary interactions between the enzyme and the carrier, ensuring multipoint attachment. The best balance between the activity yield (51.5%), enzyme loading (25.6 mg/g), and stability (stabilization factor 22.2) was achieved for the partially modified PGA. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:43–53, 2016 相似文献
6.
Although it is generally accepted that Europeans exhibit the highest frequencies of Carabelli's trait (70-90%), these values represent the expression of all possible morphological grades. When only a well-defined trait expression is considered (grades 5th, 6th and 7th), the frequency is much lower, not more than 19.2% for the 5th grade, and significantly less for the 6th and 7th grades. Our observations based on the study of the Croatian (Central European) populations show the highest frequencies for grade of the trait (exceeding 23%). Comparative data for European or European derived populations demonstrate significant variation in grade expression. While the previously published data suggest that the highest grade of the trait expression does not exceed 10%, our figures show the highest yet known frequency of a well-defined trait. 相似文献
7.
8.
Structure of the integrin binding fragment from fibrillin-1 gives new insights into microfibril organization 总被引:5,自引:0,他引:5
Lee SS Knott V Jovanović J Harlos K Grimes JM Choulier L Mardon HJ Stuart DI Handford PA 《Structure (London, England : 1993)》2004,12(4):717-729
Human fibrillin-1, the major structural protein of extracellular matrix (ECM) 10-12 nm microfibrils, is dominated by 43 calcium binding epidermal growth factor-like (cbEGF) and 7 transforming growth factor beta binding protein-like (TB) domains. Crystal structures reveal the integrin binding cbEGF22-TB4-cbEGF23 fragment of human fibrillin-1 to be a Ca(2+)-rigidified tetragonal pyramid. We suggest that other cbEGF-TB pairs within the fibrillins may adopt a similar orientation to cbEGF22-TB4. In addition, we have located a flexible RGD integrin binding loop within TB4. Modeling, cell attachment and spreading assays, immunocytochemistry, and surface plasmon resonance indicate that cbEGF22 bound to TB4 is a requirement for integrin activation and provide insight into the molecular basis of the fibrillin-1 interaction with alphaVbeta3. In light of our data, we propose a novel model for the assembly of the fibrillin microfibril and a mechanism to explain its extensibility. 相似文献
9.
Neelaredoxin, an iron-binding protein from the syphilis spirochete, Treponema pallidum, is a superoxide reductase 总被引:4,自引:0,他引:4
10.
Djordjević VA Jovanović JV Pavković-Lučić SB Drakulić DD Djurović MM Gotić MD 《Genetics and molecular research : GMR》2010,9(4):2213-2221
Cytogenetic findings are reported for 31 female patients with Turner's syndrome. Chromosome studies were made from lymphocyte cultures. Non-mosaicism 45,X was demonstrated in 15 of these patients, whereas only three were apparently mosaic. Eight patients showed non-mosaic and four patients showed mosaic structural aberrations of the X-chromosome. One non-mosaic case displayed a karyotype containing a small marker chromosome. Conventional cytogenetics was supplemented by fluorescence in situ hybridization (FISH) with an X-specific probe to identify the chromosomal origin of the ring and a 1q12-specific DNA probe to identify de novo balanced translocation (1;9) in one patient. To our knowledge, this is the first finding of karyotype 45,X,t(1;9)(cen;cen)/46,X,r(X),t(1;9)(cen;cen) in Turner's syndrome. The same X-specific probe was also used to identify a derivative chromosome in one patient. 相似文献