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1.
Nikolova Emiliya Dimova Petia Minkin Krasimir Todorov Tihomir Mitev Vanio Todorova Albena 《Journal of neurovirology》2020,26(6):984-987
Journal of NeuroVirology - In the current study, a 58-year-old male patient presented with recurrent glioblastoma multiforme (GBM). The patient underwent surgical resection, 4 months... 相似文献
2.
Multivariate survival data are frequently encountered in biomedical applications in the form of clustered failures (or recurrent events data). A popular way of analyzing such data is by using shared frailty models, which assume that the proportional hazards assumption holds conditional on an unobserved cluster-specific random effect. Such models are often incorporated in more complicated joint models in survival analysis. If the random effect distribution has finite expectation, then the conditional proportional hazards assumption does not carry over to the marginal models. It has been shown that, for univariate data, this makes it impossible to distinguish between the presence of unobserved heterogeneity (eg, due to missing covariates) and marginal nonproportional hazards. We show that time-dependent covariate effects may falsely appear as evidence in favor of a frailty model also in the case of clustered failures or recurrent events data, when the cluster size or number of recurrent events is small. When true unobserved heterogeneity is present, the presence of nonproportional hazards leads to overestimating the frailty effect. We show that this phenomenon is somewhat mitigated as the cluster size grows. We carry out a simulation study to assess the behavior of test statistics and estimators for frailty models in such contexts. The gamma, inverse Gaussian, and positive stable shared frailty models are contrasted using a novel software implementation for estimating semiparametric shared frailty models. Two main questions are addressed in the contexts of clustered failures and recurrent events: whether covariates with a time-dependent effect may appear as indication of unobserved heterogeneity and whether the additional presence of unobserved heterogeneity can be detected in this case. Finally, the practical implications are illustrated in a real-world data analysis example. 相似文献
3.
Theodor Abelin 《Sozial- und Pr?ventivmedizin》1987,32(6):277-279
Ohne Zusammenfassung 相似文献
4.
A 59-year-old hypertensive male, 1 year after uncomplicatedmitral annuloplasty for regurgitation with MAZE procedure, witha history of chronic obstructive pulmonary disease and repeatedpulmonary 相似文献
5.
K. O'Connor M. H. Freeston D. Gareau Y. Careau M. J. Dufour F. Aardema C. Todorov 《Clinical psychology & psychotherapy》2005,12(2):87-96
The principal goal of the current study was to compare the efficacy of two treatment formats, group and individual, of an empirically proven manualized cognitive–behavioural treatment (CBT) package, for obsessions without overt compulsions. It was hypothesized that individualized treatment would be more effective both in terms of post-treatment group mean improvement and end state functioning. A secondary goal was to assess the relationship between cognitive and behavioural change during treatment and link it to symptom change. Both group and individual CBT format produced a significant clinical change, but as expected individual treatment produced the greater change in symptoms and in obsessional belief. Also, the individual format showed a clear superiority over the group format in the reduction of anxiety and depression. Severity of OCD symptoms showed little relationship with strength of obsessional beliefs at the start of treatment, but change in beliefs was strongly correlated with behavioural improvement post-treatment. The results of the study suggest that the impact of a group format may lie in the value of shared social support and motivational effect of peer feedback, but at the expense of individualized targets. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
6.
Eugenija Zuskin E. Neil Schachter Bozica Kanceljak Jadranka Mustajbegovic Theodor J. Witek 《International archives of occupational and environmental health》1994,66(5):317-324
The relationship of skin reactivity and serum immunoglobulin E (IgE) levels to the prevalence of chronic respiratory symptoms and to ventilatory capacity is examined in workers exposed to different organic aerosols. The results from group of control workers similarly tested are also presented. Workers exposed to occupational allergens had positive skin tests more frequently than did controls, except for soy bean workers. Workers with positive skin tests to occupational allergens had a higher prevalence of almost all symptoms than those with negative skin tests although the differences did not always reach statistical significance. Workers with positive skin reactions in general had significantly higher serum IgE levels than did workers with negative skin reactions. There were across-shift reductions of ventilatory capacity in all groups of exposed workers, varying for forced vital capacity from 1.7% to 13.3%, for forced expiratory volume from 0.4%–21.9%, for maximum flow rates at 50% from 1.5% to 16.1% and for maximum flow rates at the last 25% of control vital capacity from 0% to 24.9%. There was, however, no correlation between acute and chronic lung function changes and skin reactivity or IgE values. Our data suggest that although exposure to organic aerosols may be associated with frequent immunologic reactions, these findings do not predict objective respiratory impairment.The research was supported in part by grant no. JBP 733 from the National Institutes of Health, Bethesda, Md., USA, and by grant no. RO1 OHO-2593-04 from the National Institutes of Occupational Safety and Health, Centers for Disease Control, Atlanta, Ga., USA 相似文献
7.
Antitumor activity of thaliblastine (NSC-68075) in experimental ovarian tumor cell lines sensitive and resistant to cisplatin. 总被引:1,自引:0,他引:1
Cytotoxicity of thaliblastine (thalicarpine, TBL; NSC-68075) and/or cisplatin (DDP) in DDP-sensitive (O-342) and-resistant (O-342/DDP) rat ovarian tumor cell lines was comparatively determined using the MTT assay. The 50% inhibitory dose (ID50) of DDP was found to be 6.2 microM in O-342 cells and 23.4 microM in O-342/DDP cells, while, vice versa, the ID50 of TBL was 39.3 micrograms/ml in the sensitive line and 27.3 micrograms/ml in the resistant line. Furthermore, simultaneous exposure of cells to DDP and TBL showed a significant superiority over DDP alone in O-342 cells, as evaluated with variance analysis (P less than 0.001). This enhancing effect of TBL on DDP cytotoxicity, however, was not observed in the resistant cells. 相似文献
8.
The triphenyl and tributyl phosphine initiated polymerization of maleic anhydride was investigated. The structure of the macro zwitterions, formed under the given reaction conditions, depended on the initiator employed. If the polymerization was initiated by triphenyl phosphine, the macromolecules contained succinic anhydride units and cyclopentanone derivatives, formed from further rearrangement. If, however, tributyl phosphine was employed as initiator, the polymers were mostly made up of conjugated ketoolefinic units. IR, NMR and mass spectrometric measurements were carried out to determine the structure of the polymers. Existence of the macro zwitterions was proved by high voltage electrophoresis. The semi-conductor properties of the polymers containing conjugated ketoolefinic units are discussed. Spectroscopic investigation of the kinetics of the triphenyl phosphine initiated polymerization of maleic anhydride showed that the initiation reaction of the ylide, formed with the monomer, proceeded about 90 times slower than the propagation reaction due to addition of the monomer to the growing chain-end. 相似文献
9.
Ohne ZusammenfassungHerr Professor Dr.James E. Rothman wurde 1950 in Haverhill/Mass. geboren, studierte am Yale-College und am Department of Biological Chemistry, Harvard Medical School sowie am Department of Biology, Massachusetts Inst. of Technology von 1967–1978. Daraufhin wurde er Assistant Professor, 3 Jahre später Associate Professor und nach weiteren 3 Jahren Professor am Department of Biochemistry, Stanford University. Seit 1988 ist er Squibb Professor of Molecular Biology am Department of Biology an der Princeton University.Herr Prof. Dr.K.W.A. Wirtz wurde 1942 in Utrecht geboren, erhielt seine Ausbildung in Biochemie und Physiologie an den Universitäten von Utrecht und Cornell Univ. Ithaka und promovierte mit einer Arbeit unter Prof. L.L.M. van Deenen (Heinrich-Wieland-Preis 1971). Unterbrochen durch längere Aufenthalte im Ausland, wurde er 1973 Assistant Professor und 1980 Professor für Biochemie an seiner heutigen Wirkungsstätte. 相似文献
10.
Theodor Pfleiderer Peter Otto Wolfgang Hardegg 《Journal of molecular medicine (Berlin, Germany)》1959,37(1):39-42
Zusammenfassung Die Kaliumkonzentration im Blutserum nach der Gerinnung ist höher als im Blutplasma, dessen Gerinnung durch Heparin, Äthylendiamintetraessigsäure (EDTA) oder Citrat verhindert wurde. Die Differenz beträgt beim Hund 15–20%, beim Menschen 12–16% und beim Rind 8–10%.Der Unterschied wird durch den bei der Gerinnung des Blutes auftretenden Zerfall der Thrombocyten hervorgerufen, deren Kaliumgehalt überraschend hoch ist (mindestens das 10–20fache der Konzentration im Plasma).Aus diesem Grund geben Kaliumbestimmungen im Serum, bei denen das Blut während der Präparation der Proben gerinnt, zu hohe Werte gegenüber der tatsächlich in vivo herrschenden Konzentration im Plasma. Messungen der Kaliumkonzentration sollten immer im Plasma erfolgen, wobei als gerinnungshemmende Substanzen Heparin oder EDTA geeignet sind. 相似文献