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1.
Electric nanogenerators that directly convert the energy of moving drops into electrical signals require hydrophobic substrates with a high density of static electric charge that is stable in “harsh environments” created by continued exposure to potentially saline water. The recently proposed charge-trapping electric generators (CTEGs) that rely on stacked inorganic oxide–fluoropolymer (FP) composite electrets charged by homogeneous electrowetting-assisted charge injection (h-EWCI) seem to solve both problems, yet the reasons for this success have remained elusive. Here, systematic measurements at variable oxide and FP thickness, charging voltage, and charging time and thermal annealing up to 230 °C are reported, leading to a consistent model of the charging process. It is found to be controlled by an energy barrier at the water-FP interface, followed by trapping at the FP-oxide interface. Protection by the FP layer prevents charge densities up to −1.7 mC m−2 from degrading and the dielectric strength of SiO2 enables charge decay times up to 48 h at 230 °C, suggesting lifetimes against thermally activated discharging of thousands of years at room temperature. Combining high dielectric strength oxides and weaker FP top coatings with electrically controlled charging provides a new paradigm for developing ultrastable electrets for applications in energy harvesting and beyond. 相似文献
2.
The expression of cytokeratins (CK), involucrin, vimentin, CD34, and alpha-smooth-muscle actin was studied in fetal and adult hair follicles. The first stage of the developing hair follicle is characterized by palisaded, elongated epithelial cells budding from the epidermal basal layer. These cells express CK5/6, CK14, CK17, CK19, and vimentin. During the following weeks of gestation, different structures in the developing hair follicle can be identified and characterized. The matrical cells display only CK19. The keratinocytes of the outer root sheath express CK5/6, CK14, CK17, CK19, and involucrin; those of the inner root sheath, CK4, CK18, and involucrin; those of the isthmus, the same profile as the ORS. In the infundibulum, the basal-layer keratinocytes express CK5/6, CK14, CK17, and CK19, whereas in the suprabasal layers CK1, CK4, CK10, CK14, and CK17 are seen. The adult hair follicle in anagen fails to express CK19 in the matrical cells and isthmus and both CK17 and CK19 in the infundibulum. These profiles of intermediate filaments and other markers appear to be potentially useful in categorizing neoplasms with apparent follicular differentiation. 相似文献
3.
PURPOSE: To summarize the pathologic diagnoses of a large number of surgically-obtained specimens over an extended time period in a single ophthalmic pathology laboratory. METHODS: We analyzed the records of 24,444 surgically obtained specimens accessioned in the L.F. Montgomery Ophthalmic Pathology Laboratory, Emory University, Atlanta, GA between May 1941 and December 1995. Age, sex, topography, clinical procedure, and histologic diagnosis were entered into a database using the modified SNOMED coding system. The diagnosis of the surgically enucleated eyes were analyzed with respect to years of enucleation. RESULTS: The most common topographic area associated with a histologic diagnosis was the cornea (39.3%), followed by lens (16.0%), vitreous (12.0%), uvea (9.8%), eyelids (8.0%), conjunctiva (7.7%), retina (7.7%), and orbit (2.1%). The relative proportion of vitreous specimens has continuously increased and became the most common surgical specimen in 1995. The most common underlying disease of surgically enucleated eyes is trauma (40.9%), followed by ocular neoplasia (24.2%), 'surgical' diseases of the cornea, lens and retina including glaucoma (17.3%), vascular diseases (6.7%), and inflammatory conditions (6.7%). The relative frequency of trauma and ocular inflammation as a cause of enucleation decreased significantly (p < 0.05) over the time of the study period while the relative proportion of ocular neoplastic processes increased (p < 0.0001). CONCLUSIONS: The availability of new surgical techniques has caused a change in the relative frequencies of different ocular specimens submitted for histologic examination. 相似文献
4.
First break picking is a pattern recognition problem in seismic signal processing, one that requires much human effort and is difficult to automate. The authors' goal is to reduce the manual effort in the picking process and accurately perform the picking. Feedforward neural network first break pickers have been developed using backpropagation training algorithms applied either to an encoded version of the raw data or to derived seismic attributes which are extracted from the raw data. The authors summarize a study in which they applied a backpropagation fuzzy logic system (BPFLS) to first break picking. The authors use derived seismic attributes as features, and take lateral variations into account by using the distance to a piecewise linear guiding function as a new feature. Experimental results indicate that the BPFLS achieves about the same picking accuracy as a feedforward neural network that is also trained using a backpropagation algorithm; however, the BPFLS is trained in a much shorter time, because there is a systematic way in which the initial parameters of the BPFLS can be chosen, versus the random way in which the weights of the neural network are chosen 相似文献
5.
The 20-kDa protein gene is androgen regulated in rat ventral prostate. Intron 1 contains a 130-base pair complex response element (D2) that binds androgen (AR) and glucocorticoid receptor (GR) but transactivates only with AR in transient cotransfection assays in CV1 cells using the reporter vector D2-tkCAT. To better understand the function of this androgen-responsive unit, nuclear protein interactions with D2 were analyzed by DNase I footprinting in ventral prostate nuclei of intact or castrated rats and in vitro with ventral prostate nuclear protein extracts from intact, castrated, and testosterone-treated castrated rats. Multiple androgen-dependent protected regions and hypersensitive sites were identified in the D2 region with both methods. Mobility shift assays with 32P-labeled oligonucleotides spanning D2 revealed specific interactions with ventral prostate nuclear proteins. Four of the D2-protein complexes decreased in intensity within 24 h of castration. UV cross-linking of the androgen-dependent DNA binding proteins identified protein complexes of approximately 140 and 55 kDa. The results demonstrate androgen-dependent nuclear protein-DNA interactions within the complex androgen response element D2. 相似文献
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7.
J Prosser CW Hughes S Sheikha RA Kowatch GL Kramer N Rosenbarger J Trent F Petty 《Canadian Metallurgical Quarterly》1997,7(3):181-199
Plasma GABA concentrations (pGABA) were measured in 115 inpatients (aged 7-17) with child psychiatric disorders. Group mean pGABAs were compared for 38 patients with mood disorders only (MOOD), 29 with behavior disorders only (BEH), 48 with comorbid mood and behavior disorders (MOOD + BEH), and 14 normal controls (CON, aged 14-17). The BEH group was characterized by (a) high mean pGABAs (157 vs. 133 pmol/ml), (b) lower mean pGABAs in BEH subjects who had been receiving pharmacotherapy with SSRIs or other medications (p < 0.026), and (c) decreased pGABA with increasing age (p = 0.019). These features were not found in controls or in groups of patients with mood disorders (MOOD or MOOD + BEH). Elevated mean pGABA in the BEH group appeared specifically in patients with comorbid CD and ADHD, not in patients with ADHD or CD alone (p = 0.004). No patient in BEH (or CON) had pGABA below 100 pmol/ml, but low pGABAs were found in 15% of MOOD patients (who had no behavior disorder) and in 16% of MOOD + BEH patients. Pharmacotherapy did not change pGABAs in the MOOD or the MOOD + BEH groups. No pGABA differences were found among the anxiety disorders, either alone or with mood or behavior comorbidity. The finding that plasma GABA levels are elevated in nonmedicated behavior disorders that present in the absence of mood disorders, and appear to lower following medication treatments, merits increased attention to the pharmacological study of nonaffective behavior disorders. 相似文献
8.
MJ de Gortari BA Freking SM Kappes KA Leymaster AM Crawford RT Stone CW Beattie 《Canadian Metallurgical Quarterly》1997,28(4):274-290
We report the evaluation of 1036 bovine microsatellite primer pairs for their suitability as linkage markers in sheep. Approximately 58% (605/1036) of bovine primer pairs amplified a locus in sheep. Sixty-seven per cent (409/605) of amplified loci were detected as polymorphic. Marker heterozygosity, allele number and range of allele sizes were significantly lower in sheep than cattle sampled in this study. However, median fragment size was similar. These data suggest that high-resolution comparative linkage maps between closely related species can be constructed relatively efficiently. 相似文献
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10.
There are several tumors and tumorlike entities of bone that do not easily fit into the specific classifications provided elsewhere in this issue. In this article, several seemingly unrelated entities are discussed, including cystic diseases of bone (simple bone cysts and aneurysmal bone cysts), Langerhans' cell histiocytosis, benign and malignant vascular tumors of bone, and adamantinoma of long bone and its relationship to osteofibrous dysplasia. 相似文献