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排序方式: 共有148条查询结果,搜索用时 13 毫秒
41.
A new plasmid vector, pNSI, is described that allows positive selection for bacterial transformants carrying recombinant plasmids. It is a derivative of pBR327, and it includes a regulatory region from the lambdoid phage 434. The expression of the TcR gene of pNS1 is under the control of the oRpR operator-promoter of phage 434, which is regulated by the represser gene c1. The cloning sites of pNSI (StuI, NdeI, HpaI, HindIII, AsuII and EcoRI) are situated within cI; hence insertion of foreign DNA into these sites causes derepressed expression of the TcR gene from pR thus conferring the TcR phenotype on the harboring Escherichia coli strain. The use ofpNS1 is facilitated by the presence of another selectable marker, ApR its small size, and its known nucleotide sequence; no special host strain is required. 相似文献
42.
Sergej Tomi? Jelena ?oki? Sa?a Vasiliji? Nina Ogrinc Rebeka Rudolf Primo? Pelicon Dragana Vu?evi? Petar Milosavljevi? Sr?a Jankovi? Ivan An?el Jelena Rajkovi? Marjan Slak Rupnik Bernd Friedrich Miodrag ?oli? 《PloS one》2014,9(5)
Gold nanoparticles (GNPs) are claimed as outstanding biomedical tools for cancer diagnostics and photo-thermal therapy, but without enough evidence on their potentially adverse immunological effects. Using a model of human dendritic cells (DCs), we showed that 10 nm- and 50 nm-sized GNPs (GNP10 and GNP50, respectively) were internalized predominantly via dynamin-dependent mechanisms, and they both impaired LPS-induced maturation and allostimulatory capacity of DCs, although the effect of GNP10 was more prominent. However, GNP10 inhibited LPS-induced production of IL-12p70 by DCs, and potentiated their Th2 polarization capacity, while GNP50 promoted Th17 polarization. Such effects of GNP10 correlated with a stronger inhibition of LPS-induced changes in Ca2+ oscillations, their higher number per DC, and more frequent extra-endosomal localization, as judged by live-cell imaging, proton, and electron microscopy, respectively. Even when released from heat-killed necrotic HEp-2 cells, GNP10 inhibited the necrotic tumor cell-induced maturation and functions of DCs, potentiated their Th2/Th17 polarization capacity, and thus, impaired the DCs'' capacity to induce T cell-mediated anti-tumor cytotoxicity in vitro. Therefore, GNP10 could potentially induce more adverse DC-mediated immunological effects, compared to GNP50. 相似文献
43.
Since their discovery, fermentation processes have gone along not only with the industrial beverages production and breweries, but since the times of Alexander Fleming, they have become a crucial part of the health care due to antibiotics production. However, complicated dynamics and strong nonlinearities cause that the production with the use of linear control methods achieves only suboptimal yields. From the variety of nonlinear approaches, gradient method has proved the ability to handle these issues—nevertheless, its potential in the field of fermentation processes has not been revealed completely. This paper describes constant vaporization control strategy based on a double-input optimization approach with a successful reduction to a single-input optimization task. To accomplish this, model structure used in the previous work is modified so that it corresponds with the new optimization strategy. Furthermore, choice of search step is explored and various alternatives are evaluated and compared. 相似文献
44.
Anastasija Zaiko Maiju Lehtiniemi Aleksas Narščius Sergej Olenin 《Biological invasions》2011,13(8):1739-1765
This paper presents an overall bioinvasion impact assessment on the scale of a large marine region—the Baltic Sea, as defined
by the Helsinki Commission. The methodology is based on a classification of the abundance and distribution range of alien
species and the magnitude of their impacts on native communities, habitats and ecosystem functioning aggregated in a “Biopollution
Level” index (BPL) which ranges from ‘no impact’ (BPL = 0) to ‘massive impact’ (BPL = 4). The assessment performed for nine
Baltic sub-regions revealed that documented ecological impact is only known for 43 alien species out of 119 registered in
the Sea. The highest biopollution (BPL = 3, strong impact) occurs in coastal lagoons, inlets and gulfs, and the moderate biopollution
(BPL = 2)—in the open sea areas. The methodology was also used to classify species into alien (BPL = 0) versus ‘impacting’
species (BPL > 0), which can be divided into ‘potentially invasive’ (BPL = 1) and ‘invasive’ (BPL > 1) ones. No clear correlation
between the number of established alien and impacting species was found in the sub-regions of the Baltic Sea. The methodology,
although requiring a substantial research effort, proved to be useful for interregional comparisons and evaluating the bioinvasion
effects of individual alien species. 相似文献
45.
Sergej Nadalin Jasminka Giacometti Suzana Jonovska Draško Tomljanović Alena Buretić-Tomljanović 《Prostaglandins, leukotrienes, and essential fatty acids》2013,88(2):185-190
We investigated the etiology of the attenuated niacin skin flush response in schizophrenia patients. Skin response to topical niacin of 0.1 M, 0.01 M, 0.001 M, and 0.0001 M concentrations was rated using method of volumetric niacin response (VNR) and correlated to two functional A/G polymorphisms in genes: phospholipase A2 group IVA (BanI of the PLA2G4A), and rs689466 of the prostaglandin synthase-2 (PTGS2). We further tested the possible correlation between niacin response and fatty acid (FA) content of red blood cells (RBCs). We detected statistically significant but weak impact of both polymorphisms on niacin flush response in schizophrenia patients. The dosage of the G alleles of both polymorphisms was associated with higher VNR values, although each polymorphic variant accounted for only 1% of the overall flush response variability. Regarding FA content, both n?3 and n?6 polyunsaturated FAs (PUFAs) were significantly reduced in the patient group, but an association with niacin sensitivity was not detected. 相似文献
46.
Schmidt O Schuenemann VJ Hand NJ Silhavy TJ Martin J Lupas AN Djuranovic S 《Journal of molecular biology》2007,372(4):894-905
47.
Schwörer Christoph Gobet Erika van Leeuwen Jacqueline F. N. Bögli Sarah Imboden Rachel van der Knaap W. O. Kotova Nadezhda Makhortykh Sergej Tinner Willy 《Vegetation History and Archaeobotany》2022,31(2):155-170
Vegetation History and Archaeobotany - Observing natural vegetation dynamics over the entire Holocene is difficult in Central Europe, due to pervasive and increasing human disturbance since the... 相似文献
48.
Romana Šínová Jana Kudová Kristina Nešporová Sergej Karel Romana Šuláková Vladimír Velebný Lukáš Kubala 《Journal of cellular physiology》2019,234(8):13209-13219
The stimulation of myocardium repair is restricted due to the limited understanding of heart regeneration. Interestingly, endogenous opioid peptides such as dynorphins and enkephalins are suggested to support this process. However, the mechanism—whether through the stimulation of the regenerative capacity of cardiac stem cells or through effects on other cell types in the heart—is still not completely understood. Thus, a model of the spontaneous cardiomyogenic differentiation of mouse embryonic stem (mES) cells via the formation of embryoid bodies was used to describe changes in the expression and localization of opioid receptors within cells during the differentiation process and the potential of the selected opioid peptides, dynorphin A and B, and methionin-enkephalins and leucin-enkephalins, to modulate cardiomyogenic differentiation in vitro. The expressions of both κ- and δ-opioid receptors significantly increased during mES cell differentiation. Moreover, their primary colocalization with the nucleus was followed by their growing presence on the cytoplasmic membrane with increasing mES cell differentiation status. Interestingly, dynorphin B enhanced the downregulation gene expression of Oct4 characteristic of the pluripotent phenotype. Further, dynorphin B also increased cardiomyocyte-specific Nkx2.5 gene expression. However, neither dynorphin A nor methionin-enkephalins and leucin-enkephalins exhibited any significant effects on the course of mES cell differentiation. In conclusion, despite the increased expression of opioid receptors and some enhancement of mES cell differentiation by dynorphin B, the overall data do not support the notion that opioid peptides have a significant potential to promote the spontaneous cardiomyogenesis of mES cells in vitro. 相似文献
49.
Fabian M. Nensa Martin H. D. Neumann Andreas Schr?tter Andre Przyborski Thomas Mastalski Sergej Susdalzew Christina Looβe Stefan Helling Fouzi El Magraoui Ralf Erdmann Helmut E. Meyer Julian Uszkoreit Martin Eisenacher Jaehong Suh Suzanne Y. Guénette Nelli R?hner Donat K?gel Carsten Theiss Katrin Marcus Thorsten Müller 《Molecular & cellular proteomics : MCP》2014,13(2):475-488
50.
Dragicevic A Dzopalic T Vasilijic S Vucevic D Tomic S Bozic B Colic M 《Cytotherapy》2012,14(5):598-607
Background aimsRecent studies have shown that the ligation of Toll-like receptor 3 (TLR3) or Dectin-1 on human monocyte-derived dendritic cells (MoDC) elicits their maturation, but with a different outcome on immunomodulation. Therefore the aim of this work was to study the response of MoDC to the combined effect of polyinosinic:polycytydilic acid [Poly (I:C)] and curdlan, selective TLR3 and Dectin-1 agonists, respectively.MethodsImmature MoDC, generated from human monocytes, were treated with Poly (I:C), curdlan or their combination for 2 days. Phenotypic characteristics of MoDC were determined by flow cytometry, and cytokine production was measured by enzyme-linked immunosorbent assay (ELISA) and FlowCytomix, while the stimulatory capability of MoDC was tested using a mixed leukocyte reaction assay.ResultsThe combination of Poly (I:C) and curdlan induced phenotypic maturation of MoDC with the capability to stimulate an alloreactive response. Such treated MoDC up-regulated the production of interleukin (IL)-12, IL-23 and IL-10, compared with the effect of Poly (I:C) alone. Curdlan-treated MoDC stimulated the production of IL-17 by alloreactive CD4 + T cells more strongly than Poly (I:C)-treated MoDC. The opposite effect was observed for interferon(IFN)-γ production. When combined, these agonists primed MoDC to increase further the production of IFN-γ by CD4 + T cells in co-culture, especially those of naive (CD45RA +) phenotype, and IL-17 by memory (CD45RO +) CD4 + T cells.ConclusionsLigation of TLR3 and Dectin-1 receptor up-regulates T-helper (Th) 1 and Th17 immune responses compared with single agonists. These findings may have therapeutic implications for the use of MoDC in immunotherapy. 相似文献