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排序方式: 共有333条查询结果,搜索用时 15 毫秒
1.
The performances of three widely different cathode materials (Pt, strontium-doped lanthanum manganite (LSM), and NiO) have been compared for use with proton conducting Li2SO4–Al2O3 composite electrolyte, using H2S–air and H2–air fuel cells operating at 600 °C. Surface analysis and electrochemical techniques were used to characterize fresh and used electrode materials. Pt or LSM cathodes each became covered with Li2SO4 and Al2O3 and, as a consequence, the fuel cells showed poor performance. In contrast, the NiO cathode catalyst did not become covered with Li2SO4 and good fuel cell performance was achieved. Exceptionally good current densities of over 100 mA/cm2 and power densities of over 30 mW/cm2 were obtained for H2S–air fuel cells having Mo–Ni–S anode catalysts. Slight agglomeration of NiO particles during fuel cell operation had only a minor effect on performance.  相似文献   
2.
Follicular hyperkeratinization of the epithelium of the acroinfundibulum of sebaceous follicles is one of the primary events in the pathogenesis of acne vulgaris. Oral treatment with 13-cis-retinoic acid can reduce these hyperkeratoses. In order to determine whether follicular hyperkeratinization is related to disturbances of epidermal follicular lipids, we analyzed the lipids of initial comedones from 10 patients with nodulocystic acne before and after a 6th weeks oral therapy with 13-cis-retinoic acid (0.7 mg/kg body weight). The treatment with retinoid resulted in a significant increase of epidermal lipids (free sterols: +34%; ceramides: +19%, whereas the lipids of sebaceous origin decreased (glycerides: -36%). The mass ratio of free sterols to cholesterol sulfate increased by 86% compared to pre-treatment levels. These findings support the hypothesis that local follicular deficiencies of epidermal lipids due to increased sebum secretion might induce abnormal follicular keratinization.  相似文献   
3.
This study evaluated changes in the profiles of African American women presented in fashion magazines during the 20th century. Twenty-six variables were measured on a total of 119 profile photographs collected from various fashion magazines published in the 1940s through the 1990s. The photographs were divided into 6 groups corresponding to the decade in which they were published. A 1-way analysis of variance was performed, and between-group differences were examined with a Tukey multiple comparison procedure. Significant between-group differences (P <.01) were found for anteroposterior lip position, nasolabial angle, and interlabial angle, with increased fullness and more anteriorly positioned lips in the more recent decades. No significant differences were found for the frontonasal angle, the nasal tip angle, and the relationship of the chin to the upper face (total facial angle). Esthetic standards for the African-American female profile changed during the 20th century and, similar to the standards for the white profile, show a trend toward fuller and more anteriorly positioned lips.  相似文献   
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B. Melnik    G. Plewig  T. Tschung 《Allergy》1991,46(7):502-506
We demonstrate that spontaneous in vitro immunoglobulin E synthesis of atopic peripheral blood mononuclear cells could be suppressed by the addition of 10(-6) M to 10(-5) M prostaglandin E1 (PGE1) or PGE2. Impaired suppressor T lymphocyte maturation and function in atopic individuals are explained by an insufficient transmission of prostaglandin E (PGE) signals during thymic lymphocyte differentiation as well as an impaired ability of the atopic immune system to activate suppressor T cells by PGE-mediated feed back mechanisms. Decreased levels of 6-desaturated PGE-precursor fatty acids in plasma, T lymphocytes, monocytes, adipose tissue and breast milk have been observed in atopic individuals. These insights might offer a novel approach to the prevention of atopic disease by substitution of the atopic pregnant and nursing woman and her newborn infant with long-chain omega-6-fatty acids.  相似文献   
6.
We report that daily administration of the diuretic NKCC1 chloride co‐transporter, bumetanide, reduces the severity of autism in a 10‐year‐old Fragile X boy using CARS, ADOS, ABC, RDEG and RRB before and after treatment. In keeping with extensive clinical use of this diuretic, the only side effect was a small hypokalaemia. A double‐blind clinical trial is warranted to test the efficacy of bumetanide in FRX. Conclusion: This single case report showed an improvement of the scores of each test used after 3 months of treatment. Double‐blind clinical trials are warranted to test the efficacy of bumetanide in FRX.  相似文献   
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Neuroradiology - In this study, we aimed to develop a novel prediction model to identify patients in need of a non-contrast head CT exam during emergency department (ED) triage. We collected data...  相似文献   
10.
During postnatal development of CA1 pyramidal neurons, GABAergic synapses are excitatory and established prior to glutamatergic synapses. As interneurons are generated before pyramidal cells, we have tested the hypothesis that the GABAergic interneuronal network is operative before glutamate pyramidal neurons and provides the initial patterns of activity. We patch-clamp recorded interneurons in foetal (69 neurons) and neonatal P0 (162 neurons) hippocampal slices and performed a morphofunctional analysis of biocytin-filled neurons. At P0, three types of interneurons were found: (i) non-innervated "silent" interneurons (5%) with no spontaneous or evoked synaptic currents; (ii) G interneurons (17%) with GABA(A) synapses only; and (iii) GG interneurons with GABA and glutamatergic synapses (78%). Relying on the neuronal capacitance, cell body size and arborization of dendrites and axons, the three types of interneurons correspond to three stages of development with non-innervated neurons and interneurons with GABA(A) and glutamatergic synapses being, respectively, the least and the most developed. Recordings from both pyramidal neurons and interneurons in foetuses (E18-20) revealed that the majority of interneurons (65%) had functional synapses whereas nearly 90% of pyramidal neurons were quiescent. Therefore, interneurons follow the same GABA-glutamate sequence of synapse formation but earlier than the principal cells. Interneurons are the source and the target of the first synapses formed in the hippocampus and are thus in a position to modulate the development of the hippocampus in the foetal stage.  相似文献   
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