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| 1 | Bifurcation and Chaos Analysis of Nonlinear Rotor System with Axial-grooved Gas-lubricated Journal Bearing Support显示文摘Axial-grooved gas-lubricated journal bearings have been widely applied to precision instrument due to their high accuracy, low friction, low noise and high stability. The rotor system with axial-grooved gas-lubricated journal bearing support is a typical nonlinear dynamic system. The nonlinear analysis measures have to be adopted to analyze the behaviors of the axial-grooved gas-lubricated journal bearing-rotor nonlinear system as the linear analysis measures fail. The bifurcation and chaos of nonlinear rotor system with three axial-grooved gas-lubricated journal bearing support are investigated by nonlinear dynamics theory. A time-dependent mathematical model is established to describe the pressure distribution in the axial-grooved compressible gas-lubricated journal bearing. The time-dependent compressible gas-lubricated Reynolds equation is solved by the differential transformation method. The gyroscopic effect of the rotor supported by gas-lubricated journal bearing with three axial grooves is taken into consideration in the model of the system, and the dynamic equation of motion is calculated by the modified Wilson-θ-based method. To analyze the unbalanced responses of the rotor system supported by finite length gas-lubricated journal bearings, such as bifurcation and chaos, the bifurcation diagram, the orbit diagram, the Poincaré map, the time series and the frequency spectrum are employed. The numerical results reveal that the nonlinear gas film forces have a significant influence on the stability of rotor system and there are the rich nonlinear phenomena, such as the periodic, period-doubling, quasi-periodic, period-4 and chaotic motion, and so on. The proposed models and numerical results can provide a theoretical direction to the design of axial-grooved gas-lubricated journal bearing-rotor system. | ZHANG Yongfang HEI Di Lü Yanjun WANG Quandai MüLLER Norbert | 2014 | Chinese Journal of Mechanical Engineering2014，27，2： | 9 |
| 2 | Significant decrease in prevalence ofHelicobacter pylori in the Czech Republic显示文摘AIM:To study possible decrease in prevalence of Helicobacter pylori(H.pylori) infection in the Czech Republic within a 10-year period.METHODS:A total of 22 centres entered the study.The catchment areas of these centres covered cities and towns with more than 20 000 inhabitants,smaller towns(≤ 20 000 inhabitants) with surrounding villages and rural areas,and were spread over the whole country,corresponding well to the geographical distribution of the Czech population.A total of 1 837 subjects(aged 5-98 years) took part in the study,randomly selected out of 38 147 people from the general population.H.pylori infection was investigated by means of a 13 C-urea breath test.Breath samples in duplicates were analysed using isotope ratio mass spectrometry.The cut-off point was 3.5.Social and demographic characteristics were based on data from self-completed questionnaires.RESULTS:The overall prevalence of H.pylori infection was 23.5%(430/1826),and 4.8%(20/420) in children aged 15 or less.There was no statistically significant difference in prevalence between males(24.3%;208/857) and females(22.9%,222/969,P = 0.494).H.pylori infection was strongly associated with higher age,among subjects aged 55+ years,prevalence of H.pylori infection was 39.8%(252/633,P < 0.001).The highest prevalence of H.pylori infection was found among persons aged 55-64 years(43.9%,97/221) and 75+ years(37.9%,58/153).Among study subjects aged 15+ years,prevalence of H.pylori infection was significantly increased in those with lowest education(odds risk 3.19,95% CI 1.87-5.47).Compared to never married(14.1%),the prevalence of H.pylori infection was statistically significantly higher among married(35.4%,246/694,P < 0.001),divorced(36.8%,49/133,P < 0.001) and widowed study subjects(40.2%,45/112,P < 0.001),both in minimally and fully adjusted analysis.There was no significant difference in the prevalence of H.pylori infection between married and widowed subjects(35.4%,246/694 vs 40.2%,45/112,P = 0.389).There was little variation in smoking prevalence across categories of smoking and there was no evidence of an increased risk ofH.pylori infection among current or past smokers in our data(odds risk 1.04 with 95% CI 0.78-1.40 for current smokers;odds ratio 0.83 with 95% CI 0.60-1.16 for former smokers).The current prevalence of H.pylori in 2011 was significantly lower compared to the prevalence reported from identical geographical areas in 2001(23.5%vs 41.7%,P < 0.001).CONCLUSION:The overall prevalence of H.pylori infection in the general population has fallen substantially in the Czech Republic over the past 10 years. | Jan Bure Marcela Kopáová Ilona Koupil Bohumil Seifert Miluka kodová Fendrichová Jana pirková Viktor Voíek Stanislav Rejchrt TomáDouda Norbert Král Ilja Tachecí | 2012 | World Journal of Gastroenterology2012，18，32： | 8 |
| 3 | Phase I study of matuzumab in combination with 5-fluorouracil, leucovorin and cisplatin (PLF) in patients with advanced gastric and esophagogastric adenocarcinomas显示文摘 | Tanja Trarbach Marta Przyborek Norbert Schleucher Steffen Heeger Christian Lüpfert Udo Vanhoefer | 2013 | Investigational New Drugs2013，，3： | 3 |
| 4 | Antioxidant efficiency of lycopene on oxidative stress-induced damage in bovine spermatozoa显示文摘Background: Lycopene(LYC) is a natural carotenoid with powerful reactive oxygen species(ROS) scavenging activities. The aim of this study was to investigate if lycopene has the ability to reverse ROS-mediated alterations to the motility, viability and intracellular antioxidant profile of bovine spermatozoa subjected to ferrous ascorbate(Fe AA). Spermatozoa were washed out of fresh bovine semen, suspended in 2.9 % sodium citrate and subjected to LYC treatment(0.25, 0.5, 1 or 2 mmol/L) in the presence or absence of Fe AA(150 μmol/L Fe SO_4 and 750 μmol/L ascorbic acid) during a 6 h in vitro culture. Spermatozoa motion characteristics were assessed using the Sperm Vision?computer-aided sperm analysis(CASA) system. Cell viability was examined with the metabolic activity(MTT) assay,ROS generation was quantified via luminometry and the nitroblue-tetrazolium(NBT) test was applied to quantify the intracellular superoxide formation. Cell lysates were prepared at the end of the in vitro culture to investigate the intracellular activity of superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase(GPx) as well as the concentrations of glutathione(GSH) and malondialdehyde(MDA).Results: FeA A treatment led to a reduced spermatozoa motility(P < 0.001), viability(P < 0.001) and a decline of the antioxidant capacity of spermatozoa(P < 0.001) but increased the ROS generation(P < 0.001), superoxide production(P < 0.001) and lipid peroxidation(P < 0.001). LYC administration resulted in a preservation of the spermatozoa motion parameters(P < 0.001), mitochondrial activity(P < 0.001) and antioxidant characteristics(P < 0.001 with respect to SOD;P < 0.01 in relation to CAT; P < 0.05 as for GPx and GSH) with a concentration range of 1 and 2 mmol/L LYC revealed to be the most effective.Conclusions: Our results suggest that LYC exhibits significant ROS-scavenging and antioxidant properties which may prevent spermatozoa alterations caused by oxidative stress, and preserve the functionality of male reproductive cells. | Eva Tvrdá Anton Kovácik Eva Tusimová Dusan Paál Alica Mackovich Jakhongir Alimov Norbert Lukác | 2017 | Journal of Animal Science and Biotechnology2017，8，1： | 3 |
| 5 | Determination of ethyl carbamate in wine by high performance liquid chromatography显示文摘 | Zsolt Ajtony Norbert Szoboszlai László Bencs Erna Viszket Victor G. Mihucz | 2013 | Food Chemistry2013，，2： | 2 |
| 6 | Elevated insulin-like growth factor 1 receptor, hepatocyte growth factor receptor and telomerase protein expression in mild ulcerative colitis显示文摘 | Ferenc Sipos Orsolya Galamb László Herszényi Béla Molnár Norbert Solymosi Tamás Zágoni Lajos Berczi Zsolt Tulassay | 2008 | Scandinavian Journal of Gastroenterology2008，，3： | 2 |
| 7 | Experimental models in peritoneal dialysis: A European experience显示文摘 | Norbert L WimVB Mieke VL | 1998 | Kidney Int1998，54，： | 1 |
| 8 | Giant outbursts of luminous blue variables and the formation of the homunculus nebula around η carinae显示文摘 | Guillermo G | 1999 | The Astrophysical Journal1999，520，7： | 1 |
| 9 | Treatment of severe pulmonary hypertension:A bradykinin receptor 2 agonist B9972 causes reduction of pulmonary artery pressure and fight ventricular hypertrophy显示文摘 | TARASEVICIENE S L SCERBAVICIUS R NORBERT F V | 2005 | Peptides2005，26，8： | 1 |
| 10 | Biotechnological intensification of biogas production显示文摘 | Zoltán Bagi Norbert ács Balázs Bálint Lenke Horváth Krisztina Dobó Katalin R. Perei Gábor Rákhely Kornél L. Kovács | 2007 | Applied Microbiology and Biotechnology2007，，2： | 1 |
| 11 | A Simplified Risk Score for Predicting Postoperative Nausea and Vomiting: Conclusions from Cross-validations between Two Centers显示文摘 | Christian C. Apfel Esa L??r? Merja Koivuranta Clemens-A. Greim Norbert Roewer | 1999 | Anesthesiology1999，，3： | 1 |
| 12 | A Simplified Risk Score for Predicting Postoperative Nausea and Vomiting: Conclusions from Cross-validations between Two Centers显示文摘 | Christian C. Apfel Esa L??r? Merja Koivuranta Clemens-A. Greim Norbert Roewer | 1999 | Anesthesiology1999，，3： | 1 |
| 13 | Matrix Metalloproteinase-9 Expression in the Normal Mucosa–Adenoma–Dysplasia–Adenocarcinoma Sequence of the Colon显示文摘 | László Herszényi Ferenc Sipos Orsolya Galamb Norbert Solymosi István Hritz Pál Miheller Lajos Berczi Béla Molnár Zsolt Tulassay | 2008 | Pathology & Oncology Research2008，，1： | 1 |
| 14 | Nanosatellite and microsystem technology capabilitis, limitation and applications显示文摘 | M Seven K Manfred L Norbert | 2005 | Acta Astron2005，39，4： | 1 |
| 15 | Quanticationof fungal DNA by using fluorescence resonance energytransfer and the light cycler system显示文摘 | Juergen L Norbert H Holger H | 2000 | J Clin Microbi-ol2000，38，2： | 1 |
| 16 | potentials of aluminum pressure die casting显示文摘 | NORBERT G PETER L HUBERT K | 2003 | Casting Plant and Technology Interna-tional2003，，3： | 1 |
| 17 | ECG baseline wander and pow-erline interference reduction using nonlinear filter bank显示文摘 | JACEK M L NORBERT H | 2005 | Signal Processing2005，85，： | 1 |
| 18 | Differential mobilization of P in the maize rhizosphere by citric acid and potassium citrate 显示文摘 | Laura P Norbert C Jones D L | 2006 | Soil Biology & Biochemistry2006，38，： | 1 |
| 19 | Effects of native and modified lowdensity lipoproteins on monocyte recruitment in atherosclerosis 显示文摘 | Christian AG Norbert L Klaus L | 2007 | Hypertension2007，50，2： | 1 |
| 20 | Imprtance of blood pressure and volume control in peritoneal dialysis patients显示文摘 | Norbert L Wim VB | 2001 | Perit Dial Int2001，21，2： | 1 |
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