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171.
One of major problems in image auto-annotation is the difference between the expected word counts vector and the resulted word counts vector. This paper presents a new approach to automatic image annotation—an algorithm called resulted word counts optimizer which is an extension to existing methods. An ideal annotator is defined in terms of recall quality measure. On the basis of the ideal annotator an optimization criterion is defined. It allows to reduce the difference between resulted and expected word counts vectors. The proposed algorithm can be used with various image auto-annotation algorithms because its generic nature. Additionally, it does not increase the computational complexity of the original annotation method processing phase. It changes output word probabilities according to a pre-calculated vector of correction coefficients.  相似文献   
172.
Polyethyleneimine (PEI) induced immune responses were investigated in human bronchial epithelial (hBE) cells and mice. PEI rapidly induced ATP release from hBE cells and pretreatment with glutathione (GSH) blocked the response. PEI activated two conductive pathways, VDAC-1 and pannexin 1, which completely accounted for ATP efflux across the plasma membrane. Moreover, PEI increased intracellular Ca2+ concentration ([Ca2+]i), which was reduced by the pannexin 1 inhibitor, 10Panx (50 μM), the VDAC-1 inhibitor, DIDS (100 μM), and was nearly abolished by pretreatment with GSH (5 mM). The increase in [Ca2+]i involved Ca2+ uptake through two pathways, one blocked by oxidized ATP (oATP, 300 μM) and another that was blocked by the TRPV-1 antagonist A784168 (100 nM). PEI stimulation also increased IL-33 mRNA expression and protein secretion. In vivo experiments showed that acute (4.5 h) PEI exposure stimulated secretion of Th2 cytokines (IL-5 and IL-13) into bronchoalveolar lavage (BAL) fluid. Conjugation of PEI with ovalbumin also induced eosinophil recruitment and secretion of IL-5 and IL-13 into BAL fluid, which was inhibited in IL-33 receptor (ST2) deficient mice. In conclusion, PEI-induced oxidative stress stimulated type 2 immune responses by activating ATP-dependent Ca2+ uptake leading to IL-33 secretion, similar to allergens derived from Alternaria.  相似文献   
173.
Insulation of samples and water sorption coefficient of cement mortars modified with polypropylene fibres. In the following paper are shown results of water capillary suction in cement mortars prepared in accordance with 18 different recipes. All the mortars were prepared using natural quartz sand 0 to 2 mm. The mortars were varied with the use of two different cements and two different water‐cement ratios w/c, namely clean cement CEM I 42.5 R at w/c = 0.55 and ash cement CEM II/B‐V 32.5 R at w/c = 0.55 and w/c = 0.45. These mortars were modified by adding three types of polypropylene fibres with five lengths ranging from 3 to 38 mm. All samples were insulated against humidity on the side surfaces to ensure the one‐way water flow during the execution of this experiment. In relation to each type of mortar two different types of insulation were used: a silicone coat and polyethylene foil. The comparative analysis received served to evaluate the scale of reaction to the sorption coefficient A of such factors as: the type of cement, the w/c ratio, the type and length of fibres and the type of humidity insulation. It appeared that this last factor exerted a major effect on the course of the process, and equally on the A parameter when described in terms of quantity.  相似文献   
174.
PbS nanocrystals are synthesized using colloidal techniques and have their surfaces capped with oleic acid. The absorption band edge of the PbS nanocrystals is tuned between 900 and 580?nm. The PbS nanocrystals exhibit tuneable photoluminescence with large non-resonant Stokes shifts of up to 500?meV. The magnitude of the Stokes shift is found to be dependent upon the size of PbS nanocrystals. Time-resolved photoluminescence spectroscopy of the PbS nanocrystals reveals that the photoluminescence has an extraordinarily long lifetime of 1?μs. This long fluorescence lifetime is attributed to the effect of dielectric screening similar to that observed in other IV-VI semiconductor nanocrystals.  相似文献   
175.
Near-resonant holographic interferometry is demonstrated to measure temperature and species concentration in a two-dimensional steady premixed air-acetylene flame. A peak temperature of (2600 +/- 100) K and a peak OH number density of (9.6 +/- 0.3) x 10(22) m(-3) are obtained, consistent with the expected values for such a flame. These values are determined by recording interferograms with a laser assumed sufficiently detuned from line center so that pressure and temperature broadening can be ignored. The results are thus obtained without making prior assumptions on the temperature or pressure of the flame beyond the existence of thermal equilibrium.  相似文献   
176.
Holographic interferometry measurements have been performed on high-speed, high-temperature gas flows with a laser output tuned near a resonant sodium transition. The technique allows the detection and quantification of the sodium concentration in the flow. By controlling the laser detuning and seeded sodium concentration, we performed flow visualization in low-density flows that are not normally detectable with standard interferometry. The technique was also successfully used to estimate the temperature in the boundary layer of the flow over a flat plate.  相似文献   
177.
178.
The periplasmic hydrogenase (hydrogen: ferricytochrome-c3 oxido-reductase EC 1.12.2.1) from Desulfovibrio desulfuricans (NCIMB 8372) was isolated and the catalytic properties of the enzyme determined with different electron mediators. In the direction of H2-oxidation with the physiological electron mediator cytochrome c3, the value of the apparent second order rate constant (kcat/Km) is close to that expected for a diffusion-controlled reaction. In H2-production however, the value of kcat/Km with cytochrome c3 is almost 200 times lower. When methyl viologen is used as mediator, the value of kcat/Km is the same in both directions and is intermediate to the values obtained with cytochrome c3. The close to optimum value of kcat/Km in H2-oxidation with cytochrome c3 as electron acceptor is discussed with respect to the biological role of this and related hydrogenases. H2-production occurred with the hydrogenase in a system where the mediator was reduced with either of three photosensitizers (proflavin, 5-deazariboflavin, Zn-tetraphenyl porphyrin sulphonate) upon illumination. The efficiency of different mediators is discussed.  相似文献   
179.
In recent years, new cross-linkers from renewable resources have been sought to replace toxic synthetic compounds of this type. One of the most popular synthetic cross-linking agents used for biomedical applications is glutaraldehyde. However, the unreacted cross-linker can be released from the materials and cause cytotoxic effects. In the present work, dialdehyde starch nanocrystals (NDASs) were obtained from this polysaccharide nanocrystal form as an alternative to commonly used cross-linking agents. Then, 5–15% NDASs were used for chemical cross-linking of native chitosan (CS), gelatin (Gel), and a mixture of these two biopolymers (CS-Gel) via Schiff base reaction. The obtained materials, forming thin films, were characterized by ATR-FTIR, SEM, and XRD analysis. Thermal and mechanical properties were determined by TGA analysis and tensile testing. Moreover, all cross-linked biopolymers were also characterized by hydrophilic character, swelling ability, and protein absorption. The toxicity of obtained materials was tested using the Microtox test. Dialdehyde starch nanocrystals appear as a beneficial plant-derived cross-linking agent that allows obtaining cross-linked biopolymer materials with properties desirable for biomedical applications.  相似文献   
180.
Imidazolium salts (IMSs) are the subject of many studies showing their anticancer activities. In this research, a series of novel imidazolium salts substituted with lithocholic acid (LCA) and alkyl chains of various lengths (S1–S10) were evaluated against colon cancer cells. A significant reduction in the viability and metabolic activity was obtained in vitro for DLD-1 and HT-29 cell lines when treated with tested salts. The results showed that the activities of tested agents are directly related to the alkyl chain length, where S6–S8 compounds were the most cytotoxic against the DLD-1 line and S4–S10 against HT-29. The research performed on the xenograft model of mice demonstrated a lower tendency of tumor growth in the group receiving compound S6, compared with the group receiving 5-fluorouracil (5-FU). Obtained results indicate the activity of S6 in the induction of apoptosis and necrosis in induced colorectal cancer. LCA-based imidazolium salts may be candidates for chemotherapeutic agents against colorectal cancer.  相似文献   
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