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排序方式: 共有171条查询结果,搜索用时 15 毫秒
51.
52.
Goran T. Anačkov Milica M. Rat Boris Dj. Radak Ružica S. Igić Dragana M. Vukov Marko M. Rućando Mirjana M. Krstivojević Snežana B. Radulović Dušanka Lj. Cvijanović Dubravka M. Milić Biljana I. Panjković Klara L. Szabados Ranko D. Perić Alen M. Kiš Vida R. Stojšić Pal P. Boža 《Central European Journal of Biology》2013,8(10):1032-1043
Floristic diversity in the Pannonian Plain is the result of mosaic habitat composition, characterized by steppes, saline meadows, and lowland forests along major rivers. In the last few centuries, the flora has become enriched by species introduced by human activities, such as colonization and industrialization. Presently it consists of nearly 1800 species. As a result of 30 years of field research as well as herbarium and literature searches, a list of invasive alien neophytes has been compiled and is presented here. The list includes 152 species, classified as either naturalized, casual, or unknown. One of the species is listed in Red Book of Serbian Flora. Eighty species are naturalized, and 61 are casual species. The majority of the introduced flora originates from North America (66) and the Old World (43). Most alien invasive species of the Southeastern part of the Pannonian Plain, were introduced accidentally by seed material or deliberately by nursery saplings. The annual and perennial herbaceous plants, which flower in the summer and summer-autumn periods, are represented in the greatest numbers. The alien flora was further analyzed with respect to taxonomy, life forms, pollination, and seed dispersal mode. The greatest number of alien species appears in anthropogenic and semi-natural habitats (59). In natural habitats, 45 invasive taxa were recorded, representing a conservation threat to biodiversity. 相似文献
53.
Various positive effects of pet ownership on cardiovascular health are well known. The aim of this prospective and controlled longitudinal study was to determine the effects of everyday dog-walking on physical capacity in elderly patients during the first year after myocardial infarction. Regularly dog-walking for at least 15 minutes three times a day is related to significantly higher work load on the bicycle exercise test (72.5 +/- 10.75 versus 67.6 +/- 11.6 W p < 0.05) in the "dog-walking" group (N = 29, mean age 72.5 years) at 12 months compared to the control group (N = 30, mean age 71.7 years). Our results suggest that dogs may help to maintain continuous physical activity in elderly cardiovascular patients promoting their physical capacity. Further researches are needed to confirm this association as well to identify other possible influences of dog ownership on the cardiovascular health and on the outcome in patients after myocardial infarction. 相似文献
54.
de Graaf RM Ricard G van Alen TA Duarte I Dutilh BE Burgtorf C Kuiper JW van der Staay GW Tielens AG Huynen MA Hackstein JH 《Molecular biology and evolution》2011,28(8):2379-2391
It is generally accepted that hydrogenosomes (hydrogen-producing organelles) evolved from a mitochondrial ancestor. However, until recently, only indirect evidence for this hypothesis was available. Here, we present the almost complete genome of the hydrogen-producing mitochondrion of the anaerobic ciliate Nyctotherus ovalis and show that, except for the notable absence of genes encoding electron transport chain components of Complexes III, IV, and V, it has a gene content similar to the mitochondrial genomes of aerobic ciliates. Analysis of the genome of the hydrogen-producing mitochondrion, in combination with that of more than 9,000 genomic DNA and cDNA sequences, allows a preliminary reconstruction of the organellar metabolism. The sequence data indicate that N. ovalis possesses hydrogen-producing mitochondria that have a truncated, two step (Complex I and II) electron transport chain that uses fumarate as electron acceptor. In addition, components of an extensive protein network for the metabolism of amino acids, defense against oxidative stress, mitochondrial protein synthesis, mitochondrial protein import and processing, and transport of metabolites across the mitochondrial membrane were identified. Genes for MPV17 and ACN9, two hypothetical proteins linked to mitochondrial disease in humans, were also found. The inferred metabolism is remarkably similar to the organellar metabolism of the phylogenetically distant anaerobic Stramenopile Blastocystis. Notably, the Blastocystis organelle and that of the related flagellate Proteromonas lacertae also lack genes encoding components of Complexes III, IV, and V. Thus, our data show that the hydrogenosomes of N. ovalis are highly specialized hydrogen-producing mitochondria. 相似文献
55.
56.
Vcev A Nakić D Mrden A Mirat J Balen S Ruzić A Persić V Soldo I Matijević M Barbić J Matijević V Bozić D Radanović B 《Collegium antropologicum》2007,31(3):757-760
The aim of this investigation was to determine the seroprevalence of H. pylori in patients with coronary artery disease (CAD). Patients with coronary artery disease (n = 90) and control group (n = 90) were enrolled into this randomized, multi-centre study. CAD risk factors analyzed included age, male gender, diabetes mellitus, systemic hypertension, cigarette smoking, hypercholesterolemia and socioeconomic status. The results of this study showed a higher seroprevalence of Helicobacter pylori infection in patients with CAD compared to controls (78.8% versus 58.3%, p < 0.05). However, Helicobacter pylori seropositivity was not associated with coronary artery risk factors (smoking, body mass index, diabetes mellitus, hypertension, total cholesterol and socioeconomic status) either in the whole study population or in the patients and control subjects analyzed separately (P > 0.05). Further study are needed to clarify the precise role of Helicobacter pylori infection on the development of coronary artery disease. 相似文献
57.
S. A. Alen’kina V. R. Zharkova V. E. Nikitina 《Applied Biochemistry and Microbiology》2007,43(6):583-586
Lectins from the surface of Azospirillum brasilense Sp7 and Azospirillum brasilense Sp7.2.3 (a mutant with impaired lectin activity) were shown to induce a stabilizing effect on the activity of almond β-glucosidase under conditions of thermoinactivation and proteolytic enzyme treatment. Differences were revealed in the influence of lectins with various antigenic properties. Our results indicate that the effects of lectins on the catalytic activity of the enzyme are mainly associated with conformational changes in lectin molecules during mutagenesis, but not with carbohydrate specificity (general property). These data should be taken into account in evaluating the role of lectins in the formation of nitrogen-fixing associations. 相似文献
58.
Spodoptera frugiperda (Lepidoptera: Noctuidae) host-plant variants: two host strains or two distinct species? 总被引:1,自引:0,他引:1
59.
Jennifer Morger Lars Rberg Sabine M. Hille Sanne Helsen Jan tefka Mohammad M. Al‐Sabi Christian M. O. Kapel Tapio Mappes Sandra Essbauer Rainer G. Ulrich Paola Bartolommei Alessio Mortelliti Linas Bal
iauskas Nico W. van den Brink Alice Rmy Anna Bajer Mihail Cheprakov Misa Korva Ana L. García‐Prez Roman Biek Susan Withenshaw Barbara Tschirren 《Biological journal of the Linnean Society. Linnean Society of London》2015,116(1):124-133
Parasite‐mediated selection may contribute to the maintenance of genetic variation at host immune genes over long time scales. To date, the best evidence for the long‐term maintenance of immunogenetic variation in natural populations comes from studies on the major histocompatibility complex (MHC) genes, whereas evidence for such processes from other immune genes remains scarce. In the present study, we show that, despite pronounced population differentiation and the occurrence of numerous private alleles within populations, the innate immune gene Toll‐like receptor 2 (TLR2) displays a distinct haplotype structure in 21 bank vole (Myodes glareolus) populations across Europe. Haplotypes from all populations grouped in four clearly differentiated clusters, with the three main clusters co‐occurring in at least three previously described mitochondrial lineages. This pattern indicates that the distinct TLR2 haplotype structure may precede the split of the mitochondrial lineages 0.19–0.56 Mya and suggests that haplotype clusters at this innate immune receptor are maintained over prolonged time in wild bank vole populations. 相似文献
60.
Svetlana A. Alen’kina Vladimir A. Bogatyrev Larisa Y. Matora Marina K. Sokolova Marina P. Chernyshova Ksenia A. Trutneva Valentina E. Nikitina 《Plant and Soil》2014,378(1-2):337-349