Microanalysis and preliminary pharmacokinetic studies of a sulfated polysaccharide from Laminariajaponica

A rapid, sensitive and reproducible high performance liquid chromatography （HPLC） method with post-column fluorescence derivatization has been developed to determine the amount of low-molecular- weight sulfated polysaccharide （GFS） in vivo. The metabolism of GFS has been shown to fit a two component model following its administration by intravenous injection, and its pharmacokinetic parameters were determined to be as follows： half-time of distribution phase （t1/2α）=11.2±2.93 min, half-time of elimination phase （tl/2α）=98.20±25.78 min, maximum concentration （Cmax）=110.53 gg/mL and peak time （Tmax）=5 min. The pharmacokinetic behavior of GFS was also investigated following intragastric administration. However, the concentration of GFS found in serum was too low for detection, and GFS could only be detected for up to 2 h after intragastric administration （200 mg/kg body weight）. Thus, the bioavailability of GFS was low following intragastric administration because of the metabolism of GFS. In conclusion, HPLC with post-column derivatization could be used for quantitative microanalysis and pharmacokinetic studies to determine the presence of polysaccharides in the serum following intravenous injection.

Microanalysis of Multi-Element in Juncus effusus L. by LIBS Technique

Laser-induced breakdown spectroscopy （LIBS） was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental microanalysis via LIBS. Microanalysis and multimode sampling methodologies were designed in this study. The relative standard deviation （RSD） approach was performed to optimize the multi-shot measurements. Taking advantage of the capability with no or minimal sample pre-treatment of LIBS, a thermodynamic chart of four elements （Mg, Ca, Ba, and Na） was created from twelve collection regions. The diagram of elemental distribution on a micro-scale was generated to explore the nature of Juncus effusus L. by LIBS. The results demon- strated that LIBS is a promising technique for rapid elemental microanalysis of heterogeneous samples.

Microanalysis on the Hydrogen Ion Irradiated 50 wt pct TiC-C Films

The 50 wt pct TiC-C films were prepared on stainless steel substrates by using a technique of ion beam mixing. These films were irradiated by hydrogen ion beam with a dose of 1×10^18 ions/cm^2 and an energy of 5 keV. Microanalysis of X-ray photoelectron spectroscopy （XPS） and secondary ion mass spectroscopy （SIMS） were used to analyze the films before and after hydrogen ion irradiation and to study the mechanism of hydrogen resistance.

Ore Microscopy and Microanalysis of the Nickeliferous Iron Ores from Komnina Vermion Area (N.W. Greece)

Nickel laterites are considerable sources of nickel. To be successfully exploited it is important to know the mineralogical and microstructural characteristics of the ore. Besides, the identification of the mineralogical components as well as the fabric description, can lead to the interpretation of the mechanism of deposit genesis. The aim of the present study is the microscopic and microanalytical investigation of the Fe-Ni ores from Komnina Vermion area (N.W. Greece). The mineralogical composition of the ore is mainly hematite, quartz, chromite and chlorite, while in minor quantities goethite, nickeliferous chlorite, serpentine, talc and calcite are also present. The ore structure is allotriomorphic inequigranular and the texture is oolitic-pisolitic. According to microscopic examination the deposit can be registered as a secondary pseudo-autochthonous.

Detection of distribution of copper inside and outside of lysosomes in cultured hepatolenticular degeneration fibroblasts by electron probe X-ray microanalysis

OBJECTIVE: To observe the distribution of copper in the subcellular structure for the understanding of primary pathogenesis of hepatolenticular degeneration (HLD). METHODS: Skin fibroblasts taken from HLD patients were cultured as an in vitro model of HLD, and the control cells taken from healthy volunteers were clutured in the same way. The distribution of copper inside and outside of lysosomes in fibroblasts was detected by quantitative electron probe X-ray microanalysis. The relationship between the subcellular location of copper and the genotype of the patients, and relationship between the distribution of copper and the course of the disease were analyzed. RESULTS: The content of Cu^(2+) inside lysosomes of HLD cells (14.6±2.1 mmol/kg) and of heterozygote cells (11.6±0.6 mmol/kg) was higher than that of normal cells (4.5±1.2 mmol/kg) (P<0.01). The content of Cu^(2+) outside lysosomes of HLD cells (17.5±4.2 mmol/kg) and of heterozygote cells (12.0±0.9 mmol/kg) was higher than that of normal cells (4.7±1.2 mmol/kg) (P<0.01). The distribution of copper in the subcellular structure was correlated with disease courses of HLD patients. With the progression of the disease, more copper was deposited in lysosomes (r=0.85, P<0.01). The content of copper in the diffused cytoplasmic compartment in HLD cells was correlated with that of sulfur (r=0.86, P<0.05), but not in heterozygote and normal cells. CONCLUSIONS: In the early stage of HLD, copper is accumulated outside lysosome, which is paralleled with increase of metallothionein-like proteins (copper and sulfur-binding proteins). With the development of the disease, more copper is deposited inside lysosome than outside lysosome. We conclude that the up-regulation expression of copper and sulfur-binding proteins and copper accumulation in lysosomes may play an important role in lowering the ATP7B gene mutation-induced toxic effects of free copper on the cell.

Electron probe microanalysis оf experimentally stimulated osteoarthrosis in dogs

AIM To develop methods of articular cartilage preparation for X-ray-electron probe microanalysis and to study its elements content in experimental osteoarthrosis.METHODS Twenty dogs aged 2-8 years were divided in research(aged 2 years, induction of osteoarthrosis-IOA) and intact group. Intact group included three subgroups(aged 2, 5 and 8 years). Samples of cartilage after araldite saturation and pouring were partially cut into semithin sections stained with methylene blue and with methylene blue-basic fuchsin. Their smooth surfaces were investigated by X-ray-electron probe microanalysis. Spatial distribution of sulfur, calcium and phosphorus and their concentrations(weight %) were investigated.RESULTS X-ray electron probe microanalysis revealed non-uniformsulfur distribution in cartilage of intact animals: Its content increases from superficial zone to deep one, this regularity was preserved in animals with IOA. Differences of IOA with spontaneous chondropathy were revealed. Spontaneous aging was characterized by calcium and phosphorus storage in deep and calcified zones and compensatory increase of sulfated glycosaminoglycans in intermediate and deep cartilage zones as evidenced by the metachromatic reaction and microanalysis data. Unlike spontaneous chondropathy connected with aging in experimentally stimulated osteoarthrosis more intensive storage of calcium but minor phosphorus in intermediate zone were marked. In IOA the calcified cartilage thinning and osteoclastic resorption are apparent with few changes of elements composition; the only difference from control is minority phosphorus content.CONCLUSION The obtained results demonstrate specific tricks of X-ray electron probe microanalysis and its possibility in the research of mechanisms of articular cartilage alterations in osteoarthrosis.

Multielemental Microanalysis in Root and Leaves, Growth and Biomass in Tomato Seedling in Response to Ca Levels and Induction of Stress: Non-Destructive Spectroscopy

Tomatoes are one of the main vegetables in the food industry that are consumed fresh and processed. A multi-element microanalysis was performed with the use of scanning electron microscopy (SEM) in conjunction with energy dispersion spectroscopy (EDS), to see changes in nutrient concentration in roots and leaves, as well as fresh and dry biomass in tomato seedlings. Exposed in nutrient solution (NS) with different levels of Ca (control, 25, 50 and 100 mM). The root was put in also to H2O2 for 8 hours to observe the changes that occurred. It was observed that NS with 100 mM Ca in fresh stem biomass and fresh leaf biomass increased by 25% and 38% compared to the control. It was observed that the NS with 100 and 50 mM of Ca, the content of Ca and Cl in foliar tissue increased by 34.50% and 13.15% compared to the control. Treatment with H2O2 and with 25 and 100 mM of Ca at NS increased the height of the seedling and fresh leaf bio-mass by 19.75% and 60.80% compared to the control. The treatment with H2O2 and with the different levels of Ca in the NS increased the content of C, P, K, Ca and Cl in the leaf tissue. Only S was significant for the control. Treatment with H2O2 and 100 mM Ca in the NS increased Ca and Mg by 83.48% and 40.47% for the root compared to the control. The K and Cl in the root was higher in the control treatment by 47.61% and 55% respect to the highest level of Ca. It is concluded that multielemental microanalysis is a powerful, non-destructive, fast and accurate tool for the determination of plant nutrients. Also, it is applicable for the areas like horticulture, physiology and agronomy.

Effect of Beam Current and Diameter on Electron Probe Microanalysis of Carbonate Minerals

The effect of operating conditions on the time-dependent X-ray intensity variation is of great importance for the optimal EPMA conditions for accurate determinations of various elements in carbonate minerals. Beam diameters of 0, 1, 2, 5, 10, 15, and 20 μm, and beam currents of 3, 5, 10, 20,and 50 nA were tested. Ca, Mg, Zn, and Sr were found to be more sensitive to electron beam irradiation as compared to other elements, and small currents and large beam diameters minimized the timedependent X-ray intensity variations. We determined the optimal EPMA operating conditions for elements in carbonate: 10 μm and 5 nA for calcite;10 μm and 10 nA for dolomite;5 μm and 10 nA or 10 μm and 20 nA for strontianite;and 20 nA and 5 μm for other carbonate. Elements sensitive to electron beam irradiation should be determined first. In addition, silicate minerals are preferred as standards rather than carbonate minerals.

Electron probe microanalysis for revealing occurrence mode of scandium in Bayer red mud

Red mud is a bauxite residue generated during the process of alumina production. In this research, the occur- rence mode of scandium in the Bayer red mud was investi- gated mainly by electron probe microanalysis （EPMA）. The Bayer red mud used in this work is composed of 21.47 wt% hematite, 12.13 wt% goethite, 8.86 wt% gibbsite, 5.02 wt% perovskite, 9.70 wt% quartz, 3.23 wt% anhydrite, 29.92 wt% Na_2Al_2Si_5O_14 and 9.67 wt% Al_3Fe_5O_12. Besides, the scandium content in the Bayer red mud is 84.32 × 10-6, indicating that this Bayer red mud is an important scandium resource deserving exploitation. The EPMA results show that the scandium within the Bayer red mud is mainly occurring in the iron minerals of hematite and goethite with the isomorphism form, but its distribution is not homogeneous in these iron minerals with the Sc_2O_3 content between 330 × 10-6 and 2040 × 10-6. This study provides a theoretical base for the further experimental work on the scandium extraction from this Bayer red mud.

Microanalysis of silver jewellery by laser-ablation laser-induced breakdown spectroscopy with enhanced sensitivity and minimal sample ablation

Laser-ablation laser-induced breakdown spectroscopy （LA-LIBS） based on single Nd：YAG laser is used to analyze copper impurity in silver jewellery with enhanced sensitivity and minimal sample ablation. 6-30 folds signal enhancement can be achieved under the re-excitation of the breakdown laser and the spatial resolution is only determined by the ablation laser. 50 ppm limit of detection of copper is achieved when the crater diameter is 17.2 μm under current experimental condition. This technique gives higher analysis sensitivity under the same sample ablation in comparison with single pulse （SP） LIBS. It is useful for high sensitive element mieroanalvsis of precious samples.

Elemental Composition of the Shell of the Testate Amoeba Difflugia tuberspinifera (Sarcodina:Rhizopoda)

X-ray microanalysis was used to study the elemental composition of the shell of the freshwater testate amoeba Difflugia tuberspinifera Hu et al.,1997 collected from Mulan Lake,Hubei province,China in July 2003.The results show that the shell is composed of ten elements:Si in greater quantity;then Ca and Al;and traces of K,Na,Cl,Fe,Mg,S and P.The analysis of results suggests that D.tuberspinifera in elemental composition appears to occupy a middle position between marine and soil testate amoebae.

二元生物薄标样的制备技术方法

本文着重介绍,在电镜X射线微区分析工作中,如何建立二元生物薄标样的制备技术方法,以及相关的计算公式等。

Recent advances in screening of enzymes inhibitors based on capillary electrophoresis

Capillary electrophoresis with many advantages plays an important role in pharmaceutical analysis and drug screening. This review gives an overview on the recent advances in the developments and applications of capillary electrophoresis in the field of enzyme inhibitor screening. The period covers 2013 to 2017. Both the pre-capillary enzyme assays and in-capillary enzyme assays which include electrophoretically mediated microanalysis（EMMA） and immobilized enzyme microreactor（IMER） are summarized in this article.

A method of laser focusing control in microlaser-induced breakdown spectroscopy

This paper presents a method for the automatic adjustment of the laser defocusing amount in micro-laser-induced breakdown spectroscopy. A microscopic optical imaging system consisting of a CCD camera and a 20× objective lens was adopted to realize the method. The real-time auto-focusing of the system was achieved by detecting the effective pixels of the light spot generated by the laser pointer. The focusing accuracy of the method could achieve 3 μm. The element concentrations of Mn and Ni in low-alloy steels were analyzed at a crater diameter of about 35 μm using the presented method. After using the presented method, the determination coefficients of Mn and Ni both exceeded 0.997, with the root-mean-square errors being 0.0133 and 0.0395, respectively. Scanning analysis was performed on the inclined plane and the curved surface by means of focusing control and non-focusing control. Ten characteristic spectral lines of Fe were selected as the analysis lines. With the focusing control, the average relative standard deviations obtained on the inclined plane and curved surface were both less than 5%, and much less than the values without focusing control, 14.6% and 40.39%.

Effect of aluminum oxide on the compressive strength of pellets

Analytical-reagent-grade Al2O3 was added to magnetite ore during the process of pelletizing, and the methods of mercury intru-sion, scanning electron microscopy, and image processing were used to investigate the effect of Al2O3 on the compressive strength of the pellets. The results showed that, as the Al2O3 content increased, the compressive strength of the pellets increased slightly and then decreased gradually. When a small amount of Al2O3 was added to the pellets, the Al2O3 combined with fayalite （2FeO＆#183;SiO2） and the aluminosilicate （2FeO＆#183;2Al2O3＆#183;5SiO2） was generated, which releases some iron oxide and reduces the inhibition of fayalite to the solid phase of consolidation. When Al2O3 increased sequentially, high melting point of Al2O3 particles hinder the oxidation of Fe3O4 and the recrystallization of Fe2O3, making the internal porosity of the pellets increase, which leads to the decrease in compressive strength of the pellets.

Study on mechanisms of different sulfuric acid leaching technologies of chromite

The extraction of chromate from chromite via the sulfuric acid leaching process has strong potential for practical use because it is a simple and environmentally friendly process. This paper aims to study the sulfuric acid leaching process using chromite as a raw material via either microwave irradiation or in the presence of an oxidizing agent. The results show that the main phases in Pakistan chromite are ferrichromspinel, chrompicotite, hortonolite, and silicate embedded around the spinel phases. Compared with the process with an oxidizing agent, the process involving microwaves has a higher leaching efficiency. When the mass fraction of sulfuric acid was 80% and the leaching time was 20 min, the efficiency could exceed 85%. In addition, the mechanisms of these two technologies fundamentally differ. When the leaching was processed in the presence of an oxidizing agent, the silicate was leached first and then expanded. By contrast, in the case of leaching under microwave irradiation, the chromite was dissolved layer by layer and numerous cracks appeared at the particle surface because of thermal shock. In addition, the silicate phase shrunk instead of expanding.

Study on M/A islands in pipeline steel X70

The fine structure of M/A islands in pipeline steel X70 has been studied by transmission electron microscope (TEM). It is shown that the M/A islands are about 1-2 μm in size and distribute at the grain boundary of irregular massive ferrite or acicular ferrite in the microstructure of the steel undergoing TMCP (thermo-mechanical controlled processing). The analysis of diffraction contrast shows that the M/A islands consist of retained austenite and some martensite lamellae different in size and orientation. The microt winning and midrib exist in the lamella of lenticular martensite, which exhibit the typical character of high-carbon martensite. The influences of TMCP parameters on M/A islands have been studied carefully. With the increase of the cooling speed, the amount of M/A islands decrease slightly and the morphology of M/A islands changes to thin dispersive short bars from thick irregular long strips.

Interdiffusion in the Fe_2O_3-TiO_2 system

Interdiffusion in the Fe203-TiO2 system was investigated by the diffusion couple method in the temperature range of 1323 to 1473 K. The diffusion concentration curves of Ti4＋ cations were obtained by electron probe microanalysis, according to which the Boltzmann-Matano method optimized by Broeder was used to calculate the interdiffusion coeffi- cients. The interdiffusion coefficients almost increased linearly with the mole fraction of Ti4＋ cations increasing, and they were in the range of 10-12-10-11cm2-s-1. The increase of temperature could also lead to the increase of the interdiffusion coefficients at a constant concentration of Ti4＋ cations. It was also found that the thickness growth of the diffusion layer obeyed the parabolic rate law.

An FEGSTEM Study of Grain Boundary Segregation of Phosphorus during Quenching in a 2.25Cr-1Mo Steel

Quenching-induced phosphorus segregation to prior austenite grain boundaries in a 0.077 wt pct P-doped 2.25Cr-2Mo steel is examined using field emission gun scanning transmission electron microscopy （FEGSTEM）. A phosphorus level of around 1.56 at. pct is observed for the water-quenched sample. In recognition of insufficiently high spatial resolution of the technique for grain boundary composition analysis, the measured results are corrected by an analytical convolution method. The corrected phosphorus segregation level may be up to about 4.7 at. pct. The quenchinginduced phosphorus segregation is nonequilibrium segregation and the migration of vacancy-phosphorus complexes plays an important role in the kinetic process. For such a reason, the mechanism for migration of the complexes is discussed in some detail.

Strengthening of Calcium Microalloying in Pure Gold

The mechanical properties of calcium(Ca) microalloyed 24 carat gold(Au 99.9 Ca 0.1) were measured and the corresponding microstructure was observed by TEM in order to investigate the strengthening mechanism.It was observed that the microalloying of 0.1wt% Ca improved the tensile strength(by 79% and 57% for the rolling and annealing states,respectively),hardness and E-Modulus as well as reduced the ductility of the 24 carat Au.Dispersed nano-sized precipitates and high density deformation twins were found in the rolled Au 99.9 Ca 0.1,which are attributed to be the major strengthening factors.The twins subsided after annealing and the strengthening of the annealed Au 99.9 Ca 0.1 is mainly contributed by the coarsened semi-coherent precipitates.