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41.
Properties of mixtures of Portland cements and "waste steel foundry dust (WSFD)" from Czech steel works were examined. It was found that WSFDs are formed by microporous clusters of spherical particles of iron oxides, ranging in size from 10 to 100 nm. The content of ZnO in WSFD affects markedly the hydration of cement + WSFD mixtures both in solidification time and strength development. Properties of WSFD are very similar to those of very fine silicon flue dusts formed during Si and FeSi production. Cement + WSFD mixtures show long term strength stability and low heavy metals leaching even at WSFD content of 70-80wt.% The above results document the perspectives of WSFD solidification, disposal and the use of this waste material as a new additive to building materials.  相似文献   
42.
The expression of 5-HT (serotonin) receptors (sr) was analyzed in the spinal cord and ganglia of 15 human conceptuses (5–10-weeks), and in the 9-week fetus with spina bifida. We used immunohistochemical method to detect sr-positive, apoptotic (caspase-3) and proliferating (Ki-67) cells, double immunofluorescence for co-localization with protein gene peptide (pgp) 9.5 and GFAP, as well as semiquantification and statistical measurements. Following the neurulation process, moderate (sr1 and sr2) and mild (sr3) expression characterized neuroblasts in the spinal cord and ganglia. During further development, sr1 expression gradually increased in the motoneurons, autonomic and sensory neurons, while sr2 and sr3 increased strongly in floor and roof plates. In the ganglia, sr3 expression increased during limited developmental period, while sr1 and sr2 increased throughout the investigated period. Co-expression of sr/pgp 9.5 characterized developing neurons, while sr/GFAP co-localized in the roof plate. In the spinal cord and ganglia of malformed fetus, weaker sr1 and sr2 and stronger sr3 expression accompanied morphological abnormalities. Anomalous roof plate morphology showed an excess of apoptotic and proliferating cells and increased sr3 expression. Our results indicate a human-species specific sr expression pattern, and the importance of sr1 in neuronal differentiation, and sr2 and sr3 in the control of the roof plate morphogenesis in normal and disturbed development.  相似文献   
43.
The application of heterogeneous photocatalysis is described as an advanced oxidation process (AOP) for the degradation of the diazo reactive dye using immobilized TiO2 as a photocatalyst. Starting TiO2 solutions were prepared with and without the addition of polyethylene glycol (PEG) and TiO2 films were directly deposited on a borosilicate glass substrate using the sol-gel dip-coating method. The surface morphology and the nanoscale roughness of TiO2 films were studied by means of atomic force microscopy (AFM). Structural properties of TiO2 were identified by X-ray diffraction (XRD). The decomposition behaviour of organic compounds from the gels was investigated using thermal gravimetry (TG) and differential scanning calorimetry (DSC). Photocatalytic activities of TiO2 films in the process of degradation of the commercial diazo textile dye Congo red (CR), used as a model pollutant, were monitored by means of UV/vis spectrophotometry. The kinetics of the degradation of the CR dye was described with the Langmuir-Hinshelwood (L-H) kinetic model.The addition of PEG to the TiO2 solution resulted in the changes in the film surface morphology, and affected the ratio of anatase-rutile crystal phases and the photocatalytic activity of TiO2. The TiO2 film prepared with PEG is characterized by higher roughness parameters (Ra, Rmax, Rq, Rz and Zmax), a lower amount of the rutile phase of TiO2, a higher amount of the anatase phase of TiO2 and a better photocatalytic activity compared to the TiO2 film without the addition of PEG.  相似文献   
44.
The purpose of the research was to investigate crystallization behavior and sintering of cordierite synthesized by a low-price aqueous sol–gel route starting from silicic acid and magnesium and aluminum salts. Viscous sintering of the gel occurred in the temperature range of 800–850 °C, followed by μ-cordierite crystallization at about 900 °C, which proves the homogeneity of the gel. Decreasing of μ-cordierite crystallinity in a wide temperature range prior to commencing of α-cordierite crystallization at about 1200 °C indicates reconstructive type of μ- → α-cordierite transformation. The transformation was fully completed at 1350 °C. The value of the Avrami parameter indicates that μ-cordierite crystallization was controlled by surface or interface nucleation, which implies that viscous sintering occurred in the primary gel particles, which leads to shrinkage, and thereafter nucleation occurred on the surface or interface of the particles. The overall activation energy of μ-cordierite crystallization was 382.0 kJ/mol. The sinterability of the powder obtained by calcination at 1300 °C, where well-crystallized α-cordierite was formed, was better than that of the powder obtained by calcination at 850 °C, where the most intensive shrinkage occurred before the onset of crystallization of μ-cordierite.  相似文献   
45.
Lasalocid is a polyether ionophoric coccidiostat used for the prevention of coccidiosis in poultry at a prescribed concentration and during a certain time interval. Due to a public health concern about the presence of coccidiostat residues in poultry, the aim of the present study was to determine the levels of lasalocid residues in the edible tissues of broiler chickens (breast muscle, thigh muscle, heart, liver, gizzard, kidneys and skin/fat) fed commercially produced feed containing 100?mg?kg?1) of lasalocid in complete feed throughout the 5-day withdrawal period (WP). The residues were investigated by liquid chromatography coupled with electrospray ionisation (ESI) tandem mass spectrometry (MS/MS) with triple quadrupole. The limit of detection (LOD) and the limit of quantification (LOQ) of the method were 0.47 and 1.44?μg?kg?1, respectively. The average recovery based on the matrix-fortified calibrations for chicken tissues ranged between 79% and 98%. Lasalocid was found to accumulate in the liver, followed by the heart, skin/fat, kidneys, thigh muscle and gizzard. The lowest concentrations of lasalocid residues were found in the breast muscle. On day 5 of the WP, residue concentrations of lasalocid did not decline below the LOQ of the method, but were far below the maximum residue level (MRL) established for lasalocid in poultry from 20 to 100?μg kg?1 by European Commission Regulation (EU) No. 37/2010. The results confirmed that the WP established for lasalocid is sufficient to ensure the decline of its residues in the tissues of broiler chickens to the safe residue level.  相似文献   
46.
A review of a rare case of a proven mutation in the RP1 gene (RP1c.2029C>T, p. (ARG677*) in a kidney transplant patient was presented herein. According to his medical history, he had tonsillectomy performed at the age of 20 due to erythrocyturia, and at the age of 32 he was treated for malignant hypertension. The patient had been diagnosed with chronic renal failure at age 56 years. During an eye examination in 2016, retinitis pigmentosa was suspected and the patient was advised to run further tests. After an ophthalmological examination and tests, genetic testing was performed and a mutation in the RP1 gene encoding a family of proteins which are components of microtubules in photoreceptor primary cilia was proven. The literature search found that mutations in the RP1 gene have so far been exclusively associated with a non-syndromic form of retinal degeneration. However, the RP1 protein is expressed in the kidneys, and it remains unclear why the mutation of this gene so far was only specifically related to retinal photoreceptor function and not to arterial hypertension and renal disease. Primary cilia are thought to act as potential mechanosensory fluid-flow receptors in the vascular endothelium and kidney and their dysfunction results in atherosclerotic changes, hypertension, and chronic renal failure.  相似文献   
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