排序方式: 共有138条查询结果,搜索用时 31 毫秒
61.
Eduard Fron Marc Lor Roberto Pilot Gerd Schweitzer Haluk Dincalp Steven De Feyter Jens Cremer Peter Bauerle Klaus Mullen Mark Van der Auweraer Frans C De Schryver 《Photochemical & photobiological sciences》2005,4(1):61-68
Based on femtosecond time-resolved spectroscopy and single photon timing experiments, intramolecular photoinduced charge transfer has been investigated in two systems containing a peryleneimide chromophore (P) and thiophene (T) groups. The first compound bearing a single thiophene ring (PT1) is used as model and shows a behavior similar to P, studied previously, while in the compound with two thiophene rings attached (PT2) electron transfer from the thiophene donor to the peryleneimide acceptor is observed in benzonitrile. Femtosecond fluorescence upconversion and femtosecond transient absorption experiments in benzonitrile indicate that this ion-pair state formation occurs in 19 ps. This ion-pair state then decays with two time constants of 1400 and 820 ps, probably corresponding to different conformations of the thiophene rings. 相似文献
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Meric M Kasap M Gacar G Budak F Dundar D Kolayli F Eroglu C Vahaboglu H 《FEMS microbiology letters》2008,282(2):214-218
An intensive care unit (ICU)-based OXA-23-producing multiple-drug resistant Acinetobacter baumannii (MDRAB) outbreak was detected between October 2005 and October 2006. A total of 47 patients were infected/colonized with the outbreak strain. Clinical data were available from 37 patients. The all-cause mortality rate among the patients exposed to the epidemic strain was 35% (13/37). The outbreak strain and the resistance determinants were characterized both by microbiological methods and by molecular techniques. Cloning and sequencing experiments identified ISAbaI-associated bla(oxa-23) on the chromosome. Screening of imipenem-resistant Acinetobacter isolated from the ICU during the outbreak period with PCR identified 97 isolates as positive for the ISAbaI-bla(oxa-23) structure. Pulsed-field gel electrophoresis and plasmid analyses with selected nonrepetitive isolates revealed the clonality. Disk diffusion on cloxacillin-supplemented agar media and the real-time PCR experiments showed that outbreak isolates are overexpressing the ampC enzyme. This study highlights the occurrence of OXA-23-producing and ampC-overexpressing MDRAB in ICUs. 相似文献
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Background
Hemorrhagic pleural effusion, especially in the right hemithorax rarely occurs as the sole presentation of pancreatitis.Case Presentation
This article reports massive right-sided hemorrhagic pleural effusion as the sole manifestation of pancreatitis in a 16-year-old Iranian boy. The patient referred to Nemazee Hospital, the main hospital of southern Iran, with right-sided shoulder and chest pain accompanied with dyspnea. His chest x-ray showed massive right-sided pleural effusion. The pleural fluid amylase was markedly elevated (8840 U/L), higher than that in the serum (3318 U/L). Abdominal CT scan showed a cystic structure measuring about 5·2 cm in the head of pancreas, highly suggestive of a pancreatic pseudocyst. Pleural effusion resolved after 3 weeks of chest tube insertion but not completely. After this period of conservative therapy another CT scan showed that pseudocyst was still in the head of pancreas. So, external drainage was done with mushroom insertion and the patient was discharged after 40 days of hospitalization. The cause of pancreatitis could not be identified.Conclusion
Pancreatitis should be taken into consideration when hemorrhagic pleural effusion, especially in the right hemithorax occurs. 相似文献64.
65.
Sayarlioglu H Topal C Sayarlioglu M Dulger H Dogan E Erkoc R 《Mediators of inflammation》2004,13(2):119-121
OBJECTIVE: It is known that glucose concentrations of peritoneal dialysis solutions are detrimental to the peritoneal membrane. In order to determine the effect of glucose concentration on cytokine levels of peritoneal fluid of continuous ambulatory peritoneal dialysis (CAPD) patients, a cross-sectional study was performed. METHODS: Nine non-diabetic CAPD patients participated in two 8-h dwell sessions of overnight exchanges in consecutive days, with 1.36% and 3.86% glucose containing peritoneal dialysis solutions (Baxter-Eczacibas). Peritoneal dialysis fluid tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 levels were measured. RESULTS: TNF-alpha levels after 1.36% and 3.86% glucose used dwells were 23+/-14 pg/ml and 28+/-4 pg/ml, respectively (p=0.78). The IL-6 levels were 106+/-57 pg/ml and 115+/-63 pg/ml (p=0.81), respectively. CONCLUSION: In our in vivo study we found that the glucose concentration of the conventional lactate-based CAPD solution has no effect on basal IL-6 and TNF-alpha levels of peritoneal fluid. Further in vivo studies with non-lactate-based CAPD solutions are needed in order to determine the effect of glucose concentration per se on cytokine release. 相似文献
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Amphotericin B is a polyene macrolide antibiotic used to treat systemic fungal infections. Amphotericin B's chemotherapeutic action requires the formation of transmembrane channels, which are known to transmit monovalent ions. We have investigated the ion passage pathways through the pore of a realistic model structure of the channel and computed the associated thermodynamic properties. Our calculations combined the free energy computations using the Poisson equation with a continuum solvent model and the molecular simulations in which solvent molecules were present explicitly. It was found that there are no substantial structural barriers to a single sodium or chloride ion passage. Thermodynamic free energy calculations showed that the path along which the ions prefer to move is off center from the channel's central axis. In accordance with experiments, Monte Carlo molecular simulations established that sodium ions can pass through the pore. When it encounters a chloride anion in the channel, the sodium cation prefers to form a solvent-bridged pair configuration with the anion. 相似文献
69.
Molecular phylogeny of the speciose vole genus Microtus (Arvicolinae, Rodentia) inferred from mitochondrial DNA sequences 总被引:10,自引:0,他引:10
Jaarola M Martínková N Gündüz I Brunhoff C Zima J Nadachowski A Amori G Bulatova NS Chondropoulos B Fraguedakis-Tsolis S González-Esteban J José López-Fuster M Kandaurov AS Kefelioğlu H da Luz Mathias M Villate I Searle JB 《Molecular phylogenetics and evolution》2004,33(3):647-663
Voles of the genus Microtus represent one of the most speciose mammalian genera in the Holarctic. We established a molecular phylogeny for Microtus to resolve contentious issues of systematic relationships and evolutionary history in this genus. A total of 81 specimens representing ten Microtus species endemic to Europe as well as eight Eurasian, six Asian and one Holarctic species were sequenced for the entire cytochrome b gene (1140 bp). A further 25 sequences were retrieved from GenBank, providing data on an additional 23, mainly Nearctic, Microtus species. Phylogenetic analysis of these 48 species generated four well-supported monophyletic lineages. The genus Chionomys, snow voles, formed a distinct and well-supported lineage separate from the genus Microtus. The subgenus Microtus formed the strongest supported lineage with two sublineages displaying a close relationship between the arvalis species group (common voles) and the socialis species group (social voles). Monophyly of the Palearctic pitymyid voles, subgenus Terricola, was supported, and this subgenus was also subdivided into two monophyletic species groups. Together, these groupings clarify long-standing taxonomic uncertainties in Microtus. In addition, the "Asian" and the Nearctic lineages reported previously were identified although the latter group was not supported. However, relationships among the main Microtus branches were not resolved, suggesting a rapid and potentially simultaneous radiation of a widespread ancestor early in the history of the genus. This and subsequent radiations discernible in the cytochrome b phylogeny, show the considerable potential of Microtus for analysis of historical and ecological determinants of speciation in small mammals. It is evident that speciation is an ongoing process in the genus and that the molecular data provides a vital insight into current species limits as well as cladogenic events of the past. 相似文献
70.
Zoroğlu SS Yürekli M Meram I Söğüt S Tutkun H Yetkin O Sivasli E Savaş HA Yanik M Herken H Akyol O 《Cell biochemistry and function》2003,21(1):55-60
Several studies indicate that nitric oxide (NO) is involved in the aetiopathogenesis of many neuropsychiatric disorders such as schizophrenia, bipolar disorder, depression, Alzheimer's disease, Hungtington disease and stroke. Although it has not been investigated yet, several recent studies proposed that NO may have a pathophysiological role in autism. Adrenomedullin (AM), a recently discovered 52-amino acid peptide hormone, induces vasorelaxation by activating adenylate cyclase and also by stimulating NO release. AM immune reactivity is present in the brain consistent with a role as a neurotransmitter. It has been stated that NO and AM do function in the regulation of many neurodevelopmental processes. We hypothesized that NO and AM activities have been affected in autistic patients and aimed to examine these molecules. Twenty-six autistic patients and 22 healthy control subjects were included in this study. AM and total nitrite (a metabolite of NO) levels have been measured in plasma. The mean values of plasma total nitrite and AM levels in the autistic group were significantly higher than control values, respectively (p < 0.001, p = 0.028). There is no correlation between total nitrite and AM levels (r = 0.11, p = 0.31). Certainly, this subject needs much further research investigating autistic patients in earlier periods of life and with subtypes of the disorder. 相似文献