7 results on '"Küster N"'
Search Results
2. Ionization of coherent excitons by strong terahertz fields.
- Author
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Ewers, B., Küster, N. S., Woscholski, R., Koch, M., Chatterjee, S., Khitrova, G., Gibbs, H. M., Klettke, A. C., Kira, M., and Koch, S. W.
- Subjects
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IONIZATION (Atomic physics) , *PHOTONS , *EXCITON theory , *FIELD theory (Physics) , *ABSORPTION , *QUANTUM theory , *PHYSICS experiments - Abstract
The interaction of coherent excitons with intense, single-cycle terahertz (THz) pulses is investigated. A significant bleaching of the 1 Í-exciton resonance develops into a splitting of the absorption peak and the emergence of pronounced wings with increasing THz field strength. A quantum-mechanical many-body analysis attributes the experimental observations to a transition from excitonic Rabi flopping to multi-THz-photon ionization and the population of optically dark exciton states with high quantum numbers. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
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3. CYTOKINE RESPONSE ASSOCIATED WITH HEPATITIS C VIRUS CLEARANCE IN HIV COINFECTED PATIENTS INITIATING PEG INTERFERON- BASED THERAPY.
- Author
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Truong Tam Nguyen, Reihani Niloofar, Pierre-Alain Rubbo, Kuster Nils, Karine Bollore, Jacques Ducos, Georges-Philippe Pageaux, Jacques Reynes, Philippe Van de Perre, and Edouard Tuaillon
- Subjects
hepatitis C virus, HIV, cytokines ,Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
Background: Treatment against hepatitis C virus (HCV) infection based on peginterferon-a (pegIFNa) and ribavirin induces important changes on cytokine release and T cell activation. Objective: Immune response to pegIFNa-ribavirin therapy was explored in patients coinfected by HCV and HIV. Methods: Concentrations of 25 cytokines and CD8+ T cell activation were monitored in HCV/HIV coinfected patients classified as sustained virological responders (SVR, n=19) and non-responders (NR, n=11). Results: High pretreatment concentrations of IP-10 (CXCL-10) and MCP-1 (CCL-2) were associated with poor anti-HCV response. PegIFNa-ribavirin therapy increased CD8+ T cell activation and induced significant changes in levels of eleven cytokines related to both Th1 and Th2 responses in SVR (IL-1b, IL-1RA, IL-4, IL-5, IL-6, IL-7, IL-12p40/70, IL-13, IP-10, eotaxin, MCP-1) but only six cytokines in NR (IL-1b, IL-2, IL-5, IL-12p40/70, IL-13, eotaxin). Highest rise in MIP-1b and MCP-1 levels was observed four weeks after anti-HCV treatment initiation in SVR compared to NR (p=0.002 and p=0.03, respectively), whereas a decrease of IL-8 concentration was associated with treatment failure (p= 0.052). Conclusions: Higher and broader cytokine responses to pegIFNa-ribavirin therapy were observed in SVR patients compared to NR. Changes in IL-8, MIP-1b and MCP-1 serum concentrations may be associated with efficacy of pegIFNa- and ribavirin-based therapies in patients coinfected by HCV and HIV.
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- 2016
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4. Analysis of proteome response to the mobile phone radiation in two types of human primary endothelial cells
- Author
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Kuster Niels, Nylund Reetta, and Leszczynski Dariusz
- Subjects
Cytology ,QH573-671 - Abstract
Abstract Background Use of mobile phones has widely increased over the past decade. However, in spite of the extensive research, the question of potential health effects of the mobile phone radiation remains unanswered. We have earlier proposed, and applied, proteomics as a tool to study biological effects of the mobile phone radiation, using as a model human endothelial cell line EA.hy926. Exposure of EA.hy926 cells to 900 MHz GSM radiation has caused statistically significant changes in expression of numerous proteins. However, exposure of EA.hy926 cells to 1800 MHz GSM signal had only very small effect on cell proteome, as compared with 900 MHz GSM exposure. In the present study, using as model human primary endothelial cells, we have examined whether exposure to 1800 MHz GSM mobile phone radiation can affect cell proteome. Results Primary human umbilical vein endothelial cells and primary human brain microvascular endothelial cells were exposed for 1 hour to 1800 MHz GSM mobile phone radiation at an average specific absorption rate of 2.0 W/kg. The cells were harvested immediately after the exposure and the protein expression patterns of the sham-exposed and radiation-exposed cells were examined using two dimensional difference gel electrophoresis-based proteomics (2DE-DIGE). There were observed numerous differences between the proteomes of human umbilical vein endothelial cells and human brain microvascular endothelial cells (both sham-exposed). These differences are most likely representing physiological differences between endothelia in different vascular beds. However, the exposure of both types of primary endothelial cells to mobile phone radiation did not cause any statistically significant changes in protein expression. Conclusions Exposure of primary human endothelial cells to the mobile phone radiation, 1800 MHz GSM signal for 1 hour at an average specific absorption rate of 2.0 W/kg, does not affect protein expression, when the proteomes were examined immediately after the end of the exposure and when the false discovery rate correction was applied to analysis. This observation agrees with our earlier study showing that the 1800 MHz GSM radiation exposure had only very limited effect on the proteome of human endothelial cell line EA.hy926, as compared with the effect of 900 MHz GSM radiation.
- Published
- 2010
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5. Amplitude-modulated electromagnetic fields for the treatment of cancer: Discovery of tumor-specific frequencies and assessment of a novel therapeutic approach
- Author
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Munden Reginald F, Bottger Brad, Costa Frederico P, Barbault Alexandre, Bomholt Fin, Kuster Niels, and Pasche Boris
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Purpose Because in vitro studies suggest that low levels of electromagnetic fields may modify cancer cell growth, we hypothesized that systemic delivery of a combination of tumor-specific frequencies may have a therapeutic effect. We undertook this study to identify tumor-specific frequencies and test the feasibility of administering such frequencies to patients with advanced cancer. Patients and methods We examined patients with various types of cancer using a noninvasive biofeedback method to identify tumor-specific frequencies. We offered compassionate treatment to some patients with advanced cancer and limited therapeutic options. Results We examined a total of 163 patients with a diagnosis of cancer and identified a total of 1524 frequencies ranging from 0.1 Hz to 114 kHz. Most frequencies (57–92%) were specific for a single tumor type. Compassionate treatment with tumor-specific frequencies was offered to 28 patients. Three patients experienced grade 1 fatigue during or immediately after treatment. There were no NCI grade 2, 3 or 4 toxicities. Thirteen patients were evaluable for response. One patient with hormone-refractory breast cancer metastatic to the adrenal gland and bones had a complete response lasting 11 months. One patient with hormone-refractory breast cancer metastatic to liver and bones had a partial response lasting 13.5 months. Four patients had stable disease lasting for +34.1 months (thyroid cancer metastatic to lung), 5.1 months (non-small cell lung cancer), 4.1 months (pancreatic cancer metastatic to liver) and 4.0 months (leiomyosarcoma metastatic to liver). Conclusion Cancer-related frequencies appear to be tumor-specific and treatment with tumor-specific frequencies is feasible, well tolerated and may have biological efficacy in patients with advanced cancer. Trial registration clinicaltrials.gov identifier NCT00805337
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- 2009
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6. Lipopolysaccharide biosynthesis and traffic in the envelope of the pathogen Brucella abortus.
- Author
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Servais C, Vassen V, Verhaeghe A, Küster N, Carlier E, Phégnon L, Mayard A, Auberger N, Vincent S, and De Bolle X
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- O Antigens, Carbohydrate Metabolism, Cell Membrane, Brucella abortus genetics, Lipopolysaccharides
- Abstract
Lipopolysaccharide is essential for most Gram-negative bacteria as it is a main component of the outer membrane. In the pathogen Brucella abortus, smooth lipopolysaccharide containing the O-antigen is required for virulence. Being part of the Rhizobiales, Brucella spp. display unipolar growth and lipopolysaccharide was shown to be incorporated at the active growth sites, i.e. the new pole and the division site. By localizing proteins involved in the lipopolysaccharide transport across the cell envelope, from the inner to the outer membrane, we show that the lipopolysaccharide incorporation sites are determined by the inner membrane complex of the lipopolysaccharide transport system. Moreover, we identify the main O-antigen ligase of Brucella spp. involved in smooth lipopolysaccharide synthesis. Altogether, our data highlight a layer of spatiotemporal organization of the lipopolysaccharide biosynthesis pathway and identify an original class of bifunctional O-antigen ligases., (© 2023. The Author(s).)
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- 2023
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7. Potato plants with genetically engineered tropane alkaloid precursors.
- Author
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Küster N, Rosahl S, and Dräger B
- Subjects
- Alcohol Oxidoreductases genetics, Alcohol Oxidoreductases metabolism, Gene Expression Regulation, Plant, Gene Knockdown Techniques, Methyltransferases genetics, Methyltransferases metabolism, Phenotype, Plant Proteins genetics, Plant Proteins metabolism, Plants, Genetically Modified, RNA Interference, Solanum tuberosum genetics, Solanum tuberosum metabolism, Tropanes metabolism
- Abstract
Main Conclusion: Solanum tuberosum tropinone reductase I reduced tropinone in vivo. Suppression of tropinone reductase II strongly reduced calystegines in sprouts. Overexpression of putrescine N -methyltransferase did not alter calystegine accumulation. Calystegines are hydroxylated alkaloids formed by the tropane alkaloid pathway. They accumulate in potato (Solanum tuberosum L., Solanaceae) roots and sprouting tubers. Calystegines inhibit various glycosidases in vitro due to their sugar-mimic structure, but functions of calystegines in plants are not understood. Enzymes participating in or competing with calystegine biosynthesis, including putrescine N-methyltransferase (PMT) and tropinone reductases (TRI and TRII), were altered in their activity in potato plants by RNA interference (RNAi) and by overexpression. The genetically altered potato plants were investigated for the accumulation of calystegines and for intermediates of their biosynthesis. An increase in N-methylputrescine provided by DsPMT expression was not sufficient to increase calystegine accumulation. Overexpression and gene knockdown of StTRI proved that S. tuberosum TRI is a functional tropinone reductase in vivo, but no influence on calystegine accumulation was observed. When StTRII expression was suppressed by RNAi, calystegine formation was severely compromised in the transformed plants. Under phytochamber and green house conditions, the StTRII RNAi plants did not show phenotypic alterations. Further investigation of calystegines function in potato plants under natural conditions is enabled by the calystegine deprived StTRII RNAi plants.
- Published
- 2017
- Full Text
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