[Progress in the application of laser ablation ICP-MS to surface microanalysis in material science].

In the present paper, apparatus and theory of surface analysis is introduced, and the progress in the application of laser ablation ICP-MS to microanalysis in ferrous, nonferrous and semiconductor field is reviewed in detail. Compared with traditional surface analytical tools, such as SEM/EDS (scanning electron microscopy/energy dispersive spectrum), EPMA (electron probe microanalysis analysis), AES (auger energy spectrum), etc. the advantage is little or no sample preparation, adjustable spatial resolution according to analytical demand, multi-element analysis and high sensitivity. It is now a powerful complementary method to traditional surface analytical tool. With the development of LA-ICP-MS technology maturing, more and more analytical workers will use this powerful tool in the future, and LA-ICP-MS will be a super star in elemental analysis field just like LIBS (Laser-induced breakdown spectroscopy).

[Segregation bands analysis of steel sample using laser-induced breakdown spectroscopy].

In the present paper, under optimum experimental condition, two middle-low alloy slab and homogeneous samples were analyzed under the condition of spatial resolution about 100 microm by scanning mode. Element 2D intensity distribution can be converted into 2D concentration distribution via establishing calibration curve. The results showed that there is a central segregation for C, Si, Mn, P, S and Cu for 86 # slab sample, and C, Si, P and Ti for 174 # slab sample, the width of segregation band was estimated, and it agrees well with metallographic analysis. Homogeneous sample was analyzed by scanning mode, the result showed that C, Si, Mn, P, S and so on are well distributed, and there is no segregation band existing. 2D distribution of element intensity or concentration can be used to indirectly reflect sample's homogeneity. Compared with traditional metallographic analysis, LIBS can not only show central segregation bands position and width, but also provide 2D concentration distribution for C, Si, Mn, P, S etc in detail. This method can be used to characterize segregation band position and its width rapidly, and provide theoretical guidance for improving metallurgical process.

[Application progress of laser-induced breakdown spectroscopy for surface analysis in materials science field].

As a truly surface analytical tool, laser-induced breakdown spectroscopy (LIBS) was developed in recent ten years, and in this paper, fundamental theory, instrumentation and it's applications in material science are reviewed in detail. Application progress of elemental distribution and depth profile analysis are mainly discussed in the field of metallurgy, semiconductor and electronical materials at home and abroad. It is pointed out that the pulse energy, ambient gas and it's pressure, and energy distribution of laser beam strongly influence spatial and depth resolution, and meanwhile a approach to improving resolution considering analytical sensitivity is provided. Compared with traditional surface analytical methods, the advantage of LIBS is very large scanning area, high analytical speed, and that conducting materials or non-conducting materials both can be analyzed. It becomes a powerful complement of traditional surface analytical tool.

[The relationship between plasma homocysteine levels and diabetic peripheral neuropathy].

OBJECTIVE: To explore the relationship between plasma homocysteine levels and diabetic peripheral neuropathy (DPNP). METHODS: A crossectional analysis was conducted on 227 patients with type 2 diabetes. Peripheral neuropathy was confirmed using electromyography (EMG). The risk factors possibly associated with diabetic neuropathy or plasma homocysteine levels were analyzed in relation to likelihood of occurrence of DPNP. RESULTS: Eighty patients with neuropathy and 147 patients without neuropathy were included. Plasma homocysteine levels were significantly higher in patients with diabetic neuropathy [(12.6 ± 3.6) µmol/L] than without diabetic neuropathy [(8.2 ± 0.9) µmol/L] (P < 0.001), and the relationship remained significant after adjusting for duration of diabetes, glycosylated hemoglobin A1c (HbA1c), age, renal status, serum folate acid and vitamin B(12), and metformin [OR 1.15 (1.02 - 1.28), P < 0.05]. In addition, per increase of 4.0 µmol/L plasma homocysteine was closely related to the occurrence of neuropathy after controlling for per unit increase of other confounding factors [OR 1.17 (0.94 - 1.33), P < 0.05]. CONCLUSIONS: Hyperhomocysteinemia was an independent risk factor for the occurrence of diabetic peripheral neuropathy.

Diabetes mellitus accelerates the progression of osteoarthritis in streptozotocin-induced diabetic mice by deteriorating bone microarchitecture, bone mineral composition, and bone strength of subchondral bone.

BACKGROUND: The purpose of this study was to develop an optimal diabetes-osteoarthritis (DM-OA) mouse model to validate that diabetes aggravates osteoarthritis (OA) and to evaluate the microarchitecture, chemical composition, and biomechanical properties of subchondral bone (SB) as a consequence of the DM-OA-induced damage induced. METHODS: Mice were randomly divided into three groups: DM-OA group, OA group, and sham group. Blood glucose levels, body weight, and food intake of all animals were recorded. Serum calcium (Ca) and osteocalcin (OCN) levels were compared in the three groups. The messenger ribonucleic acid (mRNA) and protein expression of key regulators for bone metabolism were detected. A semi-quantitative grading system [Osteoarthritis Research Society International (OARSI)] was used to evaluate cartilage and SB degeneration. Microspectroscopy, microindentations, micro-computed tomography (CT) imaging, and fracture load of compression testing were also used to evaluate trabecular SB properties. RESULTS: Glycemic monitoring and pancreas pathological results indicated stable high blood glucose and massive destruction of pancreas and islet cells in the DM-OA group. Serum levels of bone specific alkaline phosphatase (ALP-B) and tartrate-resistant acid phosphatase 5b (TRACP-5b) in the DM-group were higher than those of the other two groups while levels of serum Ca and OCN were lower. Meanwhile, the protein and mRNA expression of osteoblast-specific biomarkers [osteoprotegerin/receptor activator of nuclear factor kappa-B ligand (OPG/RANKL) ratio, collagen type I (COL-I), Runt-related transcription factor 2 (RUNX-2), OCN] were suppressed, and osteoclast-specific biomarkers [sclerostin (SOST)] was elevated in the DM-OA group. The mineral-to-collagen ratio, microindentation elastic modulus, hardness, micro-architectural parameters, bone mineral density, and fracture load of SB trabecular bone of the DM-OA group joint were lower than those of the other two groups. On the other hand, The OARSI score, trabecular spacing, and structural model index of the DM-OA group joint were higher than those of the other two groups. CONCLUSIONS: The glycemic and pancreatic pathological results indicated that the DM-OA model was a simple and reliable model induced by streptozotocin (STZ) and surgery. The results revealed the mechanisms through which diabetes accelerates OA; that is, by damaging and deteriorating the functions of SB, including its microarchitecture, chemical composition, and biomechanical properties.

[Research progress on mechanism of acupuncture and moxibustion promoting fracture healing].

Acupuncture has a significant effect on promoting fracture healing. It can dredge meridians and collaterals, regulate qi and blood, eliminate swelling and remove stasis. However, its mechanism is still not fully elucidated. With the development of research, it has been found in recent years that the mechanism of acupuncture and moxibustion promoting fracture healing involves regulating the expression level of cell growth factor, activating Wnt/ß-Catenin and other signal pathways, improving local blood circulation, affecting the content of mineral elements in bone, regulating the endocrine system, promoting the differentiation and proliferation of bone cells, promoting the proliferation and activation of osteoblasts and influencing the apoptosis of bone cells And so on. The mechanism of acupuncture and moxibustion promoting fracture healing is very complex, which is still at the level of animal experiments and cells.

[Laser-induced breakdown spectrometer--a new tool for quick analysis of on-the-spot sample in metallurgy].

In metallurgical steel making a quick analysis of on-the-spot sample is required to know the process of steel making. A new-type spectrometer, laser-induced breakdown spectrometer developed by ourselves, was presented in the present paper. A Nd : YAG laser with pulse width of nanometer was used as an ionization and excitation source. Emission from the plasma ap-peared when the laser beam was focused on the surface of sample. After it was spectrally resolved by a Paschen-Runge polychromator, detected by photomultiplier detectors, integrated by gate intensifier, and converted by analog-to-digital converter, the final result was transmitted to a computer in order to complete data processing. Compared to the common spectrometer on-the-spot in metallurgy, this instrument allows fast analyis without sample preparation (one minute or less), with high precision and sensitivity, so it is very suitable for the analysis of on-the spot sample in metallurgy. In recent years with the fast development of optical fiber, on-line analysis of liquid steel and dynamical control of metallurgical processing will come true by using this instrument.

[Role of female partners in the diagnosis and treatment of erectile dysfunction].

The role of female partners in the diagnosis and treatment of erectile dysfunction (ED) is being paid more and more attention now. ED has serious adverse effects on the sexual experience of female partners, while the attitudes of female partners to ED will have a direct effect on seeking and continuing treatment behavior of ED patients. So it's necessary for clinicians to consider female partners in the clinical practice of ED. The evidence from a recently published clinical trial has demonstrated that vardenafil not only improved ED men's erectile function, but also improved the sexual quality of life for female partners, which was the ideal solution of ED couples.

Study on a series of novel self-assembly supramolecular solar cells based on a double-layer structured chromophore of Zn-porphyrins.

We prepared in this work an anchoring porphyrin and a series of hat-porphyrins. The zinc atom of the hat-porphyrins can be coordinated axially with the pyridine moiety of the anchoring porphyrin which is anchored on the titania surface by a carboxyl group. The structures of the assemblies were confirmed using computational calculations, transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS). Solar cell devices of the monomer anchoring porphyrin and its assemblies were fabricated and the photovoltaic performances were measured under standard AM 1.5 sunlight irradiance. We found that the assembly devices showed higher JSC and lower VOC than that of the monomer anchoring porphyrin device. However, the comprehensive influence of JSC and VOC led to an enhancement in the solar-to-electric power-conversion efficiency (PCE) of the assemblies. We also studied the variation of JSC and VOC using electronic absorption and emission spectroscopy, charge extraction measurements, transient photovoltage decay measurements and electrochemical impedance spectroscopy.

[Quantity of released nickel ion from Ni-Cr alloy of compound galvano-ceramic bridge].

OBJECTIVE: To evaluate the biological safety of compound galvano-ceramic bridge by measuring the consistency of released nickel ion of the galvano-form slices cohered with Ni-Cr alloy slice specimens which were immersed in artificial saliva. METHODS: Specimens were divided into five groups with four tests and one control. Test specimens were made into the structure like rectangle sandwich that one side of Ni-Cr alloy was cohered to the center surface of galvano golden base of 0.2 mm and another side was fused porcelain with the thickness of 0.3 mm (group A), 0.5 mm (group B), 1.0 mm (group C), and 0.3 mm (group D). And the Ni-Cr alloys were totally embedded in galvano golden base and firing porcelain. Naked Ni-Cr alloy was taken as control. Group D was immersed into acid artificial saliva (AS) with high fluoride, while others were in acid AS at 37 degrees C for 120 h. Then the consistency of released nickel ion in the solution was measured with inductively coupled plasma-atomic emission spectrometry (ICP-AES). RESULTS: Nickel ions detected in the artificial saliva for the groups A, B, C, and D in acid AS with or without high fluoride were all under 0.005 mg/L Significant differences were found between each test group and the control [(0.65 +/- 0.45) mg/L]. CONCLUSIONS: Galvano-ceramic bridge, Ni-Cr alloy bridge with fused porcelain and golden base, shows biological safety responsible for the consistency of released nickel ion.