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Horký D Lauschová I Illek J Pechová A Sindelár M 《Microscopy research and technique》2002,56(6):451-453
The objective of this study was to evaluate the presence of heavy metals in the hepatocytes of the animals fed a cadmium-supplemented diet and also receiving zinc and/or selenium in the injection form. The experiment involved four groups of calves (6-8, both sexes) receiving the heavy metals in various combinations for 95 days. Electron micrographs of liver cells were prepared and statistically evaluated using Student's t-test. A modified morphometric apparatus was used for morphometric examination. Exogenous cadmium showed marked accumulation in the hepatocytes. If, however, the cadmium diet was combined with zinc or selenium administration the amount of the reduction product was much lower. 相似文献
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针对目前传统摩擦磨损试验机的不足之处,开发了一种基于原位和RNT技术的摩擦磨损试验机。在合理设计和选取试验机工作系统及主要部件的基础上,采用原位全息显微技术和放射性核素技术,实现了对摩擦过程中材料磨痕表面微观形貌的在线原位观察和磨损量的实时精确测量。利用试验机对CuZ n20/100Cr6进行摩擦磨损性能实验,并对试验后试样进行了X射线电子能谱分析(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析研究。结果表明,磨痕表面形成耐磨层和晶粒细化是CuZ n20具有良好耐磨性的主要原因;试验机的实验结果精确,能为深入研究材料摩擦学行为提供重要参考依据。 相似文献
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Köhler HR 《Microscopy research and technique》2002,56(5):393-401
This review summarizes results on the intracellular distribution of metals in cells of woodlice (Isopoda), millipedes (Diplopoda), and springtails (Collembola), which are three major groups of saprophagous arthropods contributing to the turnover of soil organic matter. Although the impact of metals and also metal pollution has inevitably been shown at levels of higher biological organization than subcellular mechanisms in these animal groups, the aim of this review is to focus exclusively on storage sites and aspects of intracellular metal metabolism. Thus, methodologically, results obtained by microscopical techniques such as histochemistry, X-ray microanalysis, energy filter transmission electron microscopy, or laser microprobe mass spectrometry were given preference. Results from atomic absorption spectrophotometry of cellular fractions were kept to a minimum. In all three taxa, the main intracellular metal storage sites are various types of \"granules\" which are widely distributed throughout cell types associated with the digestive system. 相似文献
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采用5mL王水溶解试样,在最佳测量条件下,用标准曲线法建立校准曲线,通过基体匹配和内标校正相结合的方式消除基体效应,实现了ICP-MS法测定316H不锈钢中锌、硒的准确测定,各元素的相关系数均在0.999以上.将本方法用于实际样品的检测,测得结果的相对标准偏差(RSD,n=11)为7.4%~10.6%,加标回收率在92... 相似文献
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This article presents a follow-up, a more comprehensive and extensive study to a previous, but limited study on three metals in oysters from the West Cove area of Lake Calcasieu in Southwest Louisiana. Results from a two-sampling period in mid-October and mid-December 2009 showed concentrations levels in μg/g (mean of 15 oysters, ± standard deviation, and range) as determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) of cadmium, 5.0, ±0.5, 4.0–6.3, and 3.0, ±0.5, 1.8–5.3; chromium, 3.1, ±0.6, 2.0–3.6, and 1.7, ±0.6, 0.7–3.0; copper, 125.0, ±115, 58–245, and 115, ±45, 76–228; iron, 224, ±66, 142–403, and 311, ±111, 160–559; lead, 3.4, ±0.7, 1.6–5.8, and 4.7, ±2.3, 0.7–13; and zinc, 1859, ±774, 740–3471, and 1578, ±783, 692–3056. These concentrations were lower by at least a factor of 10 from the previous study on cadmium and lead but similar to store-bought oysters. The two sampling period concentrations were not statistically different for the two sampling month periods. The lowering of the concentration was attributed to a cleaner (from metals) oyster beds. Results of the six metals from soils in six different sites in the oyster beds showed comparable or slightly higher concentrations than the oysters. Water samples from the six sites were low, or below the detection limit of the ICP-OES instrument. 相似文献
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ZDDP reacts with oil-soluble copper salts to form complex compounds and these compounds can substantially surpass the initial additive in the effectiveness of antiwear and antioxidant action. Application of AES allows us to establish the influence of ZDDP and complex compounds formed by it on the structural state of the friction surfaces. The specific nature of action of these complex compounds lies in minimisation of the oxidation processes in the surface microvolumes of the lubricating medium, the consequence of which is the localisation of tribo-chemical processes of secondary structure-film formation in the thinner layers. On the whole, the results obtained offer evidence of the existence of certain interrelations and generality of the processes producing antiwear and antioxidant action by zinc dithiophosphate additives in lubricating layers. 相似文献
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Hanan H. Abd-Elhafeez Abeera Mohamoud El-Sayed Ali Meawad Ahmed Soha A. Soliman 《Microscopy research and technique》2022,85(4):1538-1556
In Sohag City, 400 samples were collected from different food markets of different meat products from two companies with high and low prices (e.g., minced meat, kofta sausage, beef burger, and luncheon meat) for determining food fraud. Light, fluorescence, and scanning electron microscopy (SEM) were used to examine the samples. “Special histochemical stains” permit the microscopic examination of different cell types, structures, and/or microorganisms. Histological examination revealed variant tissue types, besides skeletal muscles. Nuchal ligaments, bones, hyaline cartilages, white fibrocartilages, large and medium arteries, cardiac muscles, tendons, and collagenous connective tissues comprised the capsule of a parenchymatous organ. Additionally, a crystal of food additives was recognized using light microscopy and SEM. SEM allows the visualization of bacterial contamination. Using different microscopic anatomy techniques is an efficient methodology for qualitative evaluations of various meat products. No difference in quality was observed between low- and high-priced meat products. 相似文献
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Inductively coupled plasma mass spectrometry (ICP-MS) was applied to determine copper, arsenic, cadmium, lead in athletic food using Sc, Ge, In, Bi as an internal standard. The linear correlation factor for four elements are higher than 0.999. Recoveries of spiked samples are in the range of 85.5%-115.5% and precision was fine, RSD is lower than 5.0%. And these are close agreement with the reference values in three standard reference materials of GBW08503, NBS1568, GBW08571. It indicates that the method is simple, rapid, sensitive and accurate, which can meet the demand for copper, arsenic, cadmium, lead analysis in athletic food. 相似文献
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赵晶晶 《现代仪器使用与维修》2013,(6):55-58
本文采用电感耦合等离子体发射光谱法测定锌精矿、锌矿石、铅锌混合矿中的锌、铜、砷、铅、镉含量。样品经溶解后,引入ICP-AES,同时测定锌、铜、砷、铅、镉含量。该方法与现行方法相比,分析周期短,适用于大宗锌精矿商品进出口检验的要求。试验数据表明,方法的相对偏差较低,精密度好,准确可靠。 相似文献
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Lipids, particularly phospholipids (PLs), are key components of cellular membrane. PLs play important and diverse roles in cells such as chemical‐energy storage, cellular signaling, cell membranes, and cell–cell interactions in tissues. All these cellular processes are pertinent to cells that undergo transformation, cancer progression, and metastasis. Thus, there is a strong possibility that some classes of PLs are expected to present in cancer cells and tissues in cellular physiology. The mass spectrometric soft‐ionization techniques, electrospray ionization (ESI), and matrix‐assisted laser desorption/ionization (MALDI) are well‐established in the proteomics field, have been used for lipidomic analysis in cancer research. This review focused on the applications of mass spectrometry (MS) mainly on ESI‐MS and MALDI‐MS in the structural characterization, molecular composition and key roles of various PLs present in cancer cells, tissues, blood, and urine, and on their importance for cancer‐related problems as well as challenges for development of novel PL‐based biomarkers. The profiling of PLs helps to rationalize their functions in biological systems, and will also provide diagnostic information to elucidate mechanisms behind the control of cancer, diabetes, and neurodegenerative diseases. The investigation of cellular PLs with MS methods suggests new insights on various cancer diseases and clinical applications in the drug discovery and development of biomarkers for various PL‐related different cancer diseases. PL profiling in tissues, cells and body fluids also reflect the general condition of the whole organism and can indicate the existence of cancer and other diseases. PL profiling with MS opens new prospects to assess alterations of PLs in cancer, screening specific biomarkers and provide a basis for the development of novel therapeutic strategies. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 37:107‐138, 2018 相似文献
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Medicinal bark refers to structures outside the vascular cambium of stems, branches and roots of gymnospermous and dicotyledonous plants that are used as medicinal materials; bark is an important type of Chinese herbal medicine. However, identification of the species from which the bark comes can be very difficult, especially when the bark is dried and sliced. In our previous studies, we have found that fluorescence microscopy is a powerful tool for the identification of easily confused Chinese herbal medicines, powdered Chinese herbal medicines and decoction dregs. To establish the fluorescent characteristics by which medicinal barks can be identified, for ensuring their safe and effective use, a systematic microscopic investigation by normal light and fluorescence microscope was carried out on transverse section samples of 11 medicinal barks commonly used in China. Specifically, the fluorescent characteristics of mechanical tissues, including stone cells and fibres as well as secretory tissues, have been observed. The microscopic features of medicinal bark are here systematically and comparatively described and illustrated. Under the fluorescence microscope, various tissues emitted fluorescence of different colours, and we found that both the colours and the intensity can be used to distinguish and identify these barks. 相似文献
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对比研究多晶及单晶铜耐磨与耐腐蚀性能。在干摩擦条件不同载荷和速度下考察多晶及单晶铜的摩擦学性能;探讨多晶及单晶铜在3.5%NaCl溶液中的自然腐蚀及电化学腐蚀性能的差异。结果表明:在干摩擦及转速为100~400 r/min条件下,多晶铜的摩擦因数高于单晶铜,磨损量低于单晶铜;在干摩擦及载荷为20~35 N条件下,多晶铜摩擦因数高于单晶铜,磨损量无明显差异;单晶铜在NaCl溶液中比多晶铜具有较强的耐蚀性;多晶铜与45#钢磨损机制以黏着磨损为主,而单晶铜与45#钢的磨损机制以剥层磨损为主。接触表面塑性变形能力以及晶粒取向、晶界分布的差异是影响单晶铜和多晶铜磨损和腐蚀性能的主要原因;含有平直柱状晶晶界的单晶材料具有高取向性,有利于其大塑性变形;择优取向使单晶铜在晶胞尺度上的微观平面排列致密,同时晶界的减少抑制了腐蚀的扩展,从而提高了其耐蚀性。 相似文献
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Raja Jelassi Hajer Khemaissia Chedliya Ghemari Maryline Raimond Catherine Souty‐Grosset Karima Nasri‐Ammar 《Microscopy research and technique》2020,83(2):148-155
The hepatopancreas of crustaceans species has been recognized as an essential target organ to assess trace elements' effects. Due to its dynamic and capability of detoxifying trace metal, this organ often indicates distinct pathological disturbances. In the present work, we intend to evaluate the bioaccumulation of trace metal in three Orchestia species (Orchestia montagui, Orchestia gammarellus, and Orchestia mediterranea) living in symmetry in the banks of Bizerte lagoon (37°13′8″N 09°55′1″E) after their exposure during 14 days to a mixture of copper and zinc, and to highlight the effect of these metals on their hepatopancreas ultrastructure using transmission electron microscopy. At the end of the experiment, results showed that the mortality and the body mass varied according to the used nominal concentrations. Significant alterations were noted in all the treatment groups. The degree of these alterations depends on the used concentration, and they are represented especially by the cells remoteness and the border lyses, the reduction of the nuclear volume, the increase in the cytoplasm density with the presence of trace metal in the nucleus as well as in the vacuole, the disorganization and the destruction of microvilli, the condensation of the majority of cellular organelles and mitochondria swelling. Through this study, Orchestia genus could be an attractive candidate for the biochemical study of trace metal toxicity in Tunisian wetlands. 相似文献
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Functional restoration for orthopedic, systemic, or dental purposes uses a diverse range of biomaterials. Monitoring for any subsequent failures associated with pathology is vital. To this end, an alternative methodology beyond that of cutting sections by conventional microtome knife-based histomethodologies was pioneered. The method was to saw a block of tissue followed by grinding the unsupported slice to the required thickness. The sawing and grinding of unsupported bones or teeth exposed not only the specimen fragility, but also the delicacy of the associated soft tissues. Although incomplete, the significance of the technique was recognized and improvements were incorporated which persist to the present day addressing the histopathology of challenging specimens. One major improvement for preserving cellular structure as well as reducing fracture incidence was achieved by impregnating tissue samples with cross-linked resins prior to the cutting and grinding processes. Methyl and glycol methacrylate resins superseded all other choices because of the advantages of photo-initiated curing. Further pioneering work led to the formulation of increasingly appropriate resin systems and the subsequent processing protocols evolved, as clinical needs for histology-specific techniques became apparent. Over the decades, several key pioneers entered this scientific arena to develop the now established resin formulation, processing protocols, and allied applications. This has led to the commercialization of the various resin systems. The aim here is to discuss the commercially available glycol and methyl methacrylate resin systems and their practical application to a variety of important techniques used in the histological assessment of complex pathology specimens. 相似文献