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排序方式: 共有1227条查询结果,搜索用时 15 毫秒
901.
Niemiec T Szmidt M Sawosz E Grodzik M Mitura K 《Journal of nanoscience and nanotechnology》2011,11(10):9072-9077
The objective of the study was to evaluate the effect of nanodiamond (ND) particles manufactured by detonation method (size of grains 2-10 nm) on organism health status. Wistar rats were administrated with diamond nanoparticles colloid by intravenous and intraperitoneal injection. Both routes of administration increased superoxide dismutase (SOD) activity and at the same time decreased activity of glutathione reductase (GR) and glutathione peroxidase (GPx) within erythrocytes. ND did not significantly affect neither total antioxidative state (TAS) nor thiobarbituric acid reactive substances (TBARS) in examined animals blood plasma. This study was also designed to examine the effect of ND on the phagocytosis activity and oxidative burst of innate immune cells. Both intravenous and intraperitoneal administration of ND hydrocolloid decreased the number of the phagocytosing neutrophiles stimulated by E. coli. Independently of the injection method nanodiamond increased the number of cells with stimulated oxidative burst and it suppressed the mechanism of oxygen dependent bacteria elimination. 相似文献
902.
Katarzyna Nowińska Zdzisław Adamczyk Edyta Melaniuk-Wolny 《Materials and Manufacturing Processes》2015,30(12):1457-1464
The primary raw materials used in the imperial smelting process (ISP) are Zn and Pb concentrates. Dust generated in the course of ISP is recycled. The identified sphalerite grains indicate the presence of Pb, Fe, Cd sulfides, Fe and Zn oxides, as well as accompanying elements (Ca, Mn, Cu, As, Se, Ag, Sn, and Sb). The tests performed have demonstrated the differentiation in the content of the accompanying elements in sphalerite present in both charge mixture as well as in dusts. This differentiation may be an indication of the migration of these element from sphalerite to the products or to waste during the process. 相似文献
903.
Metastases of lung cancer to the spleen are a great rarity and described sporadically. The authors describe the case of the left lung cancer in which the histopathological diagnosis was made only on the base of the biopsy material taken from the metastatic lesion in the spleen. Interestingly, the location of the primary cancer site made it impossible to obtain the specimens and only a single distant metastatic lesion was found in the spleen. The case presented above is an example that metastasis can occur in every organ, sometimes can be isolated in the least probable organs, and when such organ is available for biopsy, it can be useful for pathological diagnosis. 相似文献
904.
Schultka K Ciesielski B Serkies K Sawicki T Tarnawska Z Jassem J 《Radiation protection dosimetry》2006,120(1-4):171-175
In this study, we present the results of in vivo dosimetry, using electron paramagnetic resonance in l-alanine, performed on 13 patients treated for gynaecological cancers. The doses from (137)Cs (12 samples) and (192)Ir (one sample) brachytherapy sources were determined inside vagina. The detectors had a form of small cellulose capsules tightly filled with crystalline alanine. The positions of the detectors were reconstructed from two orthogonal radiographs. The planned doses were calculated with a computer planning system (PLATO, Nucletron). The relative deviations between planned and measured doses ranged from -23 to +14%. The mean deviation from the prescribed dose was relatively low (-5%) with SD of 10%. The main sources of differences between the measured and calculated doses were attributed to uncertainty in the determination of the detector position inside the patient's body and to uncontrolled changes in the detector position during the treatment. 相似文献
905.
Katarzyna Makowska Leszek Piotrowski Zbigniew Ludwik Kowalewski 《Journal of Nondestructive Evaluation》2017,36(2):43
The paper describes an application of non-destructive volumetric magnetic and ultrasonic techniques for evaluation of the selected mechanical parameter variations of P91 steel having direct influence on its suitability for further use in critical components used in power plants. Two different types of deformation processes were carried out. First, a series of the P91 steel specimens was subjected to creep and second, one to plastic deformation in order to achieve the material with an increasing strain level up to 10%. Subsequently, non-destructive and destructive tests were performed. Magnetic methods based on measurements of magnetoacoustic emission and magnetic hysteresis loop changes as well as the ultrasonic method based on acoustic birefringence measurements, were applied. Finally, the static tensile tests were carried out in order to evaluate the mechanical parameters. It is shown that some relationships between the selected parameters coming from the non-destructive and destructive tests may be formulated. 相似文献
906.
The effect of isothermal treatment (at 675, 750 and 900 °C) on HIC (hydrogen induced cracking) in sour environments containing hydrogen sulphide of a 2205 duplex stainless steel has been investigated. The performance and microstructure of failed material were characterized by optical microscopy, scanning electron microscopy and also X-ray diffraction. Two kinds of Cr-, Mo-enriched intermetallic phases, σ and χ, were found to precipitate preferentially at /γ interfaces and within grains after different times of aging in the temperature range of 650–900 °C. After performing tests according to the NACE Standard TM 0284 (1987) the specimens were investigated by using quantitative metallography methods. The volume fraction of σ phase was changed with the time of aging and σ phase developed into coarse particles due to the high diffusibility of solute atoms at high temperatures. The variation of size and shape of σ phase particles was obtained by applying different heat treatment conditions to 2205 steel specimens. The results showed that 2205 duplex stainless steel containing nearly 12 vol.% of σ phase in dispersed conditions was resistant to step cracking in wet environments containing hydrogen sulphide. It was highly possible that a crack would propagate faster along the embrittled σ phase. However, very small cracks were found at austenite–ferrite boundaries where o phase particles were also present. 相似文献
907.
Chojnacka K 《Journal of hazardous materials》2005,121(1-3):167-173
The paper presents results of studies carried out on sorption of Cr(III) ions from aqueous solutions by eggshells as a low-cost sorbent. It was found that crushed eggshells possess relatively high sorption capacity, when comparing with other sorbents, that was evaluated as 21-160 mg/g. The effect of process parameters: pH, temperature, initial concentration of Cr(III) ions on the process kinetics was studied. It was found that the equilibrium of the process was reached after 60 min. Also equilibrium studies were performed: the effect of sorbent concentration and equilibrium Cr(III) concentration was studied. The maximum experimentally determined sorption capacity 160 mg/g was obtained at low sorbent concentration at 20 degrees C and pH 5. It was found that sorption capacity increased with the increase of Cr(III) concentration, temperature and sorbent concentration. Mathematical models describing kinetics and equilibrium of sorption were proposed. The process kinetics was described with pseudo-second-order pattern and equilibrium was described with Langmuir-type equation, and the influence of sorbate concentration, with an empirical dependence. The models were positively verified. Eggshells were able to remove the concentration of Cr(III) ions below the acceptable level, i.e. at 40 degrees C, at the initial concentration of metal ions 100 mg/kg, at sorbent concentration 15 g/l. 相似文献
908.
We discuss the impact of quantum game theory on information processing and the emerging information society. The framework, that we establish, encompasses various particular models considered in the field of artificial intelligence. This paper provides insight into the following issues: detailed analysis of a quantum algorithm solving Newcombs’ paradox, the Elitzur–Vaidman circuit breaker and the Metropolis algorithm is presented. 相似文献
909.
910.
Adam Zmysowski Jerzy Sitkowski Katarzyna Bus Katarzyna Michalska Arkadiusz Szterk 《International journal of molecular sciences》2021,22(19)
It was proven that sterols subjected to high-temperature treatment can be concatenated, which results in polymeric structures, e.g., 3β,3′β-disteryl ethers. However, it was also proven that due to increased temperature in oxygen-containing conditions, sterols can undergo various oxidation reactions. This study aimed to prove the existence and perform quantitative analysis of oxidized 3β,3′β-disteryl ethers, which could form during high-temperature treatment of sterol-rich samples. Samples were heated at 180, 200 and 220 °C for 0.5 to 4 h. Quantitative analyses of the oxidized 3β,3′β-disteryl ethers were performed with liquid extraction, solid-phase extraction and liquid chromatography coupled with mass spectrometry. Additionally, to perform this analysis, the appropriate standards of all oxidized 3β,3′β-disteryl ethers were prepared. Eighteen various oxidized 3β,3′β-disteryl ethers (derivatives of 3β,3′β-dicholesteryl ether, 3β,3′β-disitosteryl ether and 3β,3′β-distigmasteryl ether) were prepared. Additionally, the influence of metal compounds on the mechanism of ether formation at high temperatures was investigated. 相似文献