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A new technology kind of brazed monolayer cup diamond grinding wheel was developed via laser in an argon atmosphere. Grinding performances of this kind of brazed wheel in the surface grinding of the granites were studied. The experiment results show that the normal grinding forces and wear of diamond grits become higher with the increasing of the accumulated removal volume during grinding granites process. When continuous dry grinding was employed, the grits of the brazed diamond grinding wheel fail mainly in attired wear mode other than pull-out ones in conventional electroplated and sintered diamond tools, which indicates that the strong retention of brazing alloy to the diamond grits and longer service life of this kind of wheel.

The purpose of this paper is used Ansys to simulate the temperature field of laser brazing by FEM. The 3-D solid elements are used in FEM model, and nonlinear factors of temperature-dependent material properties are considered. The surface temperature grades have been attained, and the brazing experiment have been conducted, the results show that the wetting of Ni-Cr alloy to diamond is good. This study is useful for selecting reasonable processing parameters on laser brazing.

In order to develop new generation brazed Diamond grinding wheels, the joining experiments of Diamond super abrasive grains and medium carbon steel using the powder mixture of Ni-Cr alloy as active brazing alloy are carried out via laser in an argon atmosphere. The relevant characteristics of the special powder mixture, the microstructure of the interfacial region, which are both the key factors for determining the joining strength among the Diamond grains, the filler layer and the steel substrate, are investigated extensively by means of scanning electron microscope (SEM) and energy dispersion spectrometer (EDS), as well X-ray diffraction (XRD) analysis. The formation mechanism of carbide layers was discussed. All the results indicate that high strength bonding between diamond grits and the steel substrate has been successfully realized because the chromium in the Ni-based alloy segregated preferentially to the surface of the diamond to form a chromium-rich reaction product Cr3C2, and the bond between the alloy and the Diamond was established through the reaction product.

Brazing diamond grits to steel substrate using Ni-based filler alloy was carried out via laser in an argon atmosphere. Thermodynamic analysis was performed in order to research the interfacial reaction mechanism of diamond and Ni-Cr alloy during high temperature brazing. Meanwhile, microstructure of the interfacial layer was experimentally detected by scanning electron microscope (SEM), energy dispersion spectrometer (EDS) and X-ray diffraction (XRD) in this paper. The results indicate that according to the thermodynamic theory the interfacial reaction has been proved feasible, and during brazing high strength bonding between diamond grits and the steel substrate has been successfully realized because the chromium in the Ni-based alloy segregated preferentially to the surface of the diamond to form a chromium-rich reaction product Cr3C2, and the bond between the alloy and the Diamond was established through the reaction product.

Brazing diamond wheel was carried out via laser in an argon atmosphere. The interfacial microstructures among brazed diamond, the filler alloy and matrix were analyzed by scanning electron microscopy (SEM), energy dispersion spectrometer (EDS) and X- ray diffraction (XRD). The formation mechanism of carbide layers was also discussed. Finally, grinding examination of the grinding wheel was carried through. The results show that diamond can not fall off from the wheel even at heavy duty conditions.

Brazing diamond grits onto steel substrate using a Ni-based filler alloy was carried out via laser beam in an argon atmosphere. The microstructure of the interfacial region among the Diamond grits and the filler layer were investigated by means of scanning electron microscopes (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). Meanwhile, the formation mechanism of carbide layers was discussed. All the results indicated that the active element chromium in the Ni-based alloy concentrated preferentially to the surface of the grits to form a chromium-rich layer, and the hard joint between the alloy and the steel substrate is established through a cross-diffusion of iron and Ni-based alloy through parameters optimization.

Brazing diamond grits onto steel substrate using a Ni-based filler alloy was carried out via laser beam in an argon atmosphere. The microstructure of the interfacial region among the Diamond grits and the filler layer were investigated by means of scanning electron microscopes (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). Meanwhile, the formation mechanism of carbide layers was discussed. All the results indicated that the active element chromium in the Ni-based alloy concentrated preferentially to the surface of the grits to form a chromium-rich layer, and the hard joint between the alloy and the steel substrate is established through a cross-diffusion of iron and Ni-based alloy through parameters optimization.

Condition based maintenance (CBM) is becoming more and more popular in equipment maintenance. A prerequisite to widespread deployment of CBM technology and practice in industry is effective diagnostics and prognostics. A dynamic Bayesian network (DBN) based prognosis method was investigated to predict the remaining useful life (RUL) for an equipment. First, a DBN based prognosis framework and specific steps for building a DBN based prognosis model were presented. Then, the corresponding inference algorithms for DBN based prognosis were provided. Finally, a prognosis procedure based on particle filtering algorithms was used to predict the RUL of drill-bits of a vertical drilling machine, which is commonly used in industrial process. Preliminary experimental results are promising.

Brazing diamond grits onto steel substrate using a Ni-based filler alloy was carried out by laser beam in an argon atmosphere. The microstructure of the interfacial region among the Diamond grits, the filler layer and the steel substrate, were investigated by means of scanning electron microscopes (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). Meanwhile, the formation mechanism of carbide layers was discussed. All the results indicated that the active element chromium in the Ni-based alloy concentrated preferentially to the surface of the grits to form a chromium-rich layer, and the hard joint between the alloy and the steel substrate is established through a cross-diffusion of iron and Ni-based alloy.

Midazolam, lorazepam, and diazepam were recommended as emergent initial therapy for status epilepticus. However, there are no current studies to confirm the best agent for pediatric status epilepticus. We compared the efficacy of midazolam, lorazepam, and diazepam in treating pediatric status epilepticus using a network meta-analysis method. In total, 16 randomized controlled trials containing 1821 patients were included. Nonintravenous midazolam, intravenous lorazepam, and intravenous diazepam were more successful in achieving seizure cessation when compared with nonintravenous diazepam (odds ratio = 2.23, 95% credibility interval: 1.62, 3.10; odds ratio = 2.71, 95% credibility interval: 1.25, 5.89; odds ratio = 2.65, 95% credibility interval: 1.12, 6.29; respectively). Among lorazepam, midazolam, and diazepam, midazolam had the highest probability (surface under the cumulative ranking area [SUCRA] = 0.792) of achieving seizure cessation, and lorazepam had the largest probability (surface under the cumulative ranking area = 0.4346) of being the best treatment in reduction of respiratory depression. In conclusion, nonintravenous midazolam and intravenous lorazepam were superior to intravenous or nonintravenous diazepam, and intravenous lorazepam was at least as effective as nonintravenous midazolam in treating pediatric status epilepticus.

Filming-rehydration and ultrasonic method were combined to prepare ethosomes as a carrier of triptolide. A laser dynamic scattering instrument was used to determine the particle size of ethosomes. The average particle size was calculated based on the measurements of five different batches of ethosomes. To determine the entrapment efficiency, free triptolide was isolated by ultracentrifugation. The concentration of triptolide was then determined using high-performance liquid chromatography (HPLC). There was an inverse relation between the average size of the triptolide ethosomes and the concentration of ethanol, and the size increased as the phospholipid concentration increased; the entrapment efficiency of ethosomes increased with the increasing concentrations of ethanol and phospholipid. An optimal formulation was obtained when lecithin and ethanol were 2% (w/v) and 45% (v/v), respectively. Triptolide ethosomes exhibited a small particle size, even distribution and high entrapment efficiency (98%). Ethosomes have high entrapment efficiency, a good percutaneous permeability and qualities that make them particularly suitable to serve as a liposome drug carrier. The concentration of ethanol and phospholipids developed a positive impact on entrapment efficiency. Triptolide ethosomes with a ratio of 2% (w/v) lecithin to 45% ethanol (v/v) have, relatively, a small particle size, even distribution and high entrapment efficiency. Key words: Ethosomes, triptolide, liposome.

The proportion of asialoGM1 positive cells and NK activity of murine splenic cells was reduced to almost zero one day after intravenous injection of rabbit anti-asialoGM1 antibody. The cells and the activity started to increase at the latest 3 days after the injection, although the proportion was far below that of the normal control. The proportion of asialoGM1 positive cells and NK activity increased more remarkably when 1,3-β glucan, sizofiran, was administered intramuscularly one day after the antibody injection. The increases were dose related (50 – 1000 μg/mouse). The fact that sizofiran hastened the recoveries of splenic NK activity and asialoGM1 positive cells suggests sizofiran may have the activity to accelerate the differentiation of asialoGM1 positive NK cells.

The inhibitory effects of a biological response modifier (BRM), sizofiran, on sister chromatid exchanges (SCEs) in the bone marrow cells of mice treated with various anticancer agents or irradiation were investigated. Sizofiran (10 mg/kg i.m.) inhibited SCEs induced by mitomycin C (2 mg/kg i.v.), adriamycin (20 mg/kg i.v.) and cyclophosphamide (20 mg/kg i.v.) by about 20%, respectively. Analysis of the SCEs in vivo after irradiation plus sizofiran indicated that SCE levels were significantly lower than those observed in mice exposed to irradiation without sizofiran. Moreover, the effects of sizofiran were dependent on the timing of administration. Our results indicated that sizofiran should be administered simultaneously or soon after irradiation in order to minimize damage. Sizofiran also markedly restored the bone marrow cell mitosis which had been suppressed by anticancer agents, and this action was closely correlated with the prevention of increase in SCEs. These results indicate that in addition to immunopotentiating activity, sizofiran may play a role in preventing chromosomal damage induced by cancer chemotherapy and radiotherapy.

We have studied the immunological effects that accompany a change in the chemical structure of a group of antineoplastic antibiotics by comparing the immunoregulatory cytokine release during mitogen-stimulated spleen cell culture after in vivo drug treatment. Whereas bleomycin and peplomycin increased cytokine levels in culture supernatants when compared with supernatants from untreated control rat spleen cell cultures, liblomycin generally reduced cytokine levels under the same culture conditions. We then compared these results with the antitumor effects of equivalent doses of the three drugs against a highly antigenic rat fibrosarcoma, KMT-17, both in vivo and in vitro. The results suggest that the immunoaugmenting effects of these antitumor antibiotics are essential for an optimal antitumor effect in vivo, and that these effects can be drastically altered by modification of the chemical structure of the drugs employed.