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71.
In the oxidative polymerization of 2,6-dimethylphenol ( 8 ) the catalytic activities of the following semiconducting organic polymeric metal complexes were studied: polymeric complexes containing bis(ethylene-1,2-dithiolato)Cu(II) or Fe(III) complexes and copper(II) phthalocyanine structures ( 3a – c ), catalysts consisting of bis(ethylene-1,2-dithiolato)-Cu(II) or Fe(III) complex structures and hemiporphyrazine type structures ( 5a – c ), and also polymers containing a copper complex of dimercaptomaleic acid monoamide ( 7 ). It was found that a suspension of the insoluble bis(ethylene-1,2-dithiolato)Cu(II) polymeric complexes of type 3 catalyzes the polymerization in the presence of oxygen in pyridine at room temperature producing poly[oxy-(2,6-dimethyl-1,4-phenylene)] ( 9 ) in very good yields. Polymeric complexes of type 5 were inactive by themselves. However, we showed that bis(ethylene-1,2-dithiolato)Cu(II) polymeric complexes of both the 3 and 5 type possess great activities if they are used in the presence of small amounts of copper(II)-pyridine complex in pyridine solution (the chosen concentration was so low that the Cu(II)-pyridine complex alone had only a small activity). Bis(ethylene-1,2-dithiolato)Fe(III) complexes of both the 3 and 5 type were inactive even in the presence of the Cu(II)-pyridine complex.  相似文献   
72.
To identify the most rapid and reliable technique for recovery and identification of Staphylococcus aureus small-colony variants (SCVs), the colonial appearance of 106 isolates representing SCVs and the normal phenotype were evaluated on two newly described chromogenic agar media. Although almost all of the SCVs grew on the chromogenic agar media, they did not exhibit a change of color. In comparison with conventional media, S. aureus ID agar (SAID; bioMerieux, La Balme Les Grottes, France) showed the most reliable results, with 49 of 53 SCVs tested growing either as an SCV colony or with a normal phenotype after only 24 h of incubation. Growth of SCVs was often not detected before 72 h of incubation on some of the media tested. In conclusion, the most accurate and rapid method to detect both the species S. aureus and the SCV phenotype is to inoculate specimens onto both Columbia blood agar and SAID.  相似文献   
73.
Aberrant glycosylation is a common feature of metastatic sub-clones of malignant tumours and in uveal melanoma in particular, the HNK-1 glycotope has been positively correlated with poor prognosis. So far, no such correlation has been investigated in cutaneous melanoma. In order to do so, HNK-1 expression was evaluated immunohistochemically in 100 primary cutaneous melanomas and correlated with metastasis after up to 10-years' follow-up. Furthermore, HNK-1 expression was analysed in metastatic deposits (19 distant cutaneous metastases and six sentinel lymph node metastases), as well as in benign nevi. Kaplan-Meier analysis revealed a positive association between HNK-1 expression and metastasis (p < 0.005) and multivariate Cox regression analysis adjusted for the standard prognostic markers ulceration and vertical tumour thickness confirmed HNK-1 expression as an independent prognostic marker. HNK-1 expression was preserved in 42% of the distant cutaneous metastases, but metastatic cells in lymph nodes were devoid of HNK-1 immunoreactivity. None of the benign pigmented lesions exhibited HNK-1 immunoreactivity. Expression of the HNK-1 glycotope in cutaneous malignant melanoma is an independent prognostic marker of metastasis. Differential HNK-1 expression at the metastatic sites implies that its expression is modulated by the surrounding environment. As HNK-1 is also transiently expressed during migration of melanocyte precursor cells derived from the neural crest, recapitulation of this transient expression might occur during metastatic spread of cutaneous malignant melanoma.  相似文献   
74.
Summary: In the last 10 years the continuing search for gene function has yielded many mutant mice that unexpectedly showed a complete lack of lymph nodes and/or Peyer's patches. With the realization that all these functionally highly diverse genes are involved at some point in the development of lymphoid organs, the challenge now is to assign a function to the molecules involved in lymphoid organ development. It will be important to determine the sequence of molecular events and assign this to the cellular events that lead to an accumulation of hematopoietic cells in one location, ultimately forming an organized lymphoid organ. Here we will focus on CD45+CD4+CD3 cells that are the early colonizing cells in lymph nodes and Peyer's patches and develop a hypothetical model of their contribution to the creation of organized lymphoid structures.  相似文献   
75.
BACKGROUND: Circulating autoantibodies against FcepsilonRI, IgE, or both occur in approximately one third of patients with chronic idiopathic urticaria (CIU), but not all autoantibodies initiate histamine release. OBJECTIVE: We sought to classify patients with CIU into subsets on the basis of serum bioactivity and immunoreactivity and to examine the relationship between newly defined subtype and disease severity. METHODS: Sera from patients with CIU (n = 78), dermog-raphism (n = 15), and cholinergic urticaria (n = 10) and sera from healthy subjects (n = 39) were analyzed by means of Western blot analysis for anti-FcepsilonRI autoantibodies and for histamine release from basophils and dermal mast cells. In vivo reactivity of autologous serum was tested by means of intradermal injection, and CIU severity was determined on the basis of clinical interview. RESULTS: We classified sera from patients with CIU into 5 subsets: immunoreactive histamine-releasing anti-FcepsilonRI autoantibodies (n = 20 [26%]); immunoreactive anti-FcepsilonRI autoantibodies without histamine-releasing activity (n = 12 [15%]); anti-IgE-like autoantibodies (n = 7 [9%]); serum containing a mast cell-specific histamine-releasing factor (n = 7 [9%]); and sera with no identifiable factor (n = 32 [41%]). Patients with serum histamine-releasing activity had more severe urticaria than patients without such activity. Positive skin test responses to autologous sera were associated with histamine-releasing anti-FcepsilonRI autoantibodies but not with non-histamine-releasing anti-FcepsilonRI autoantibodies. Neither healthy subjects nor patients with dermographism or cholinergic urticaria had his-tamine-releasing anti-FcepsilonRI autoantibodies. CONCLUSION: These data support the specificity of functional anti-FcepsilonRI autoantibodies to CIU. The identification of distinctive subsets of patients suggests that other pathogenic mechanisms occur in CIU in addition to direct ligation of FcepsilonRI by autoantibodies causing dermal mast cell degranulation. Elucidating these mechanisms might lead to new treatments for CIU.  相似文献   
76.
Perceived failure is reported to have detrimental effects on subsequent performance in patients with major depressive disorder. We investigated the error-related negativity (ERN)/error negativity (Ne), an electrophysiological correlate of response monitoring, using a 64-channel EEG. Sixteen patients with DSM-IV major depressive disorder and 16 matched controls participated in an Eriksen flanker task with continuous performance feedback that signaled monetary reward. Compared to controls, patients with major depressive disorder showed a less negative ERN/Ne in error trials following error trials. This result might reflect impaired response monitoring processes in major depressive disorder resulting from an underactivity in a central reward pathway and/or a deficit in strategic reasoning.  相似文献   
77.
78.
Differential cortical activation by cognitive processing was studied using dimensional complexity, a measure derived from nonlinear dynamics that indicates the degrees of freedom (complexity) of a dynamic system. We examined the EEG of 32 healthy subjects at rest, during a visually presented calculation task, and during a moving shape perception task. As a nonlinear measure of connectivity, the mutual dimension of selected electrode pairs was used. The first Lyapunov coefficient was also calculated. Data were tested for non-linearity using a surrogate data method and compared to spectral EEG measures (power, coherence). Surrogate data testing confirmed the presence of nonlinear structure in the data. Cognitive activation led to a highly significant rise in dimensional complexity. While both tasks activated central, parietal and temporal areas, mental arithmetic showed frontal activation and an activity maximum at T3, while the moving shape task led to occipital activation and a right parietal activity maximum. Analysis of mutual dimension showed activation of a bilateral temporal-right frontal network in calculation. The Lyapunov coefficent showed clear topographic variation, but was not significantly changed by mental tasks (p<.09). While dimensional complexity was almost unrelated to power values, nonlinear (mutual dimension) and linear (coherence) measures of connectivity shared up to 37% of variance. Data are interpreted in terms of increased cortical complexity as a result of recruitment of asynchronously active, distributed neuronal assemblies in cognition. The topography of nonlinear dynamics are related to neuropsychological and neuroimaging findings on mental calculation and moving shape perception.  相似文献   
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