Effect of nourishing Yin and purging fire Chinese herbal mixture on delaying light-induced premature puberty in rats

OBJECTIVE:To elucidate the mechanism of the nourishing Yin and purging fire Chinese herbal mixture(NYPF)in delaying light-induced premature puberty in rats.METHODS:Twenty-one days old female SpragueDawley rats were randomly assigned to normal group(N),long light exposure group(L),NYPF and normal saline group(NS).Rats in the L,NYPF and NS groups were exposed to 16 h:350 lux light/8 h:dark,while rats in the N group were exposed to 12 h:50 lux light/12 h:dark.NYPF and normal saline was administered to the rats in the NYPF group or NS group,respectively,from day 21.Five rats in every group were sacrificed at 9 p.m.on day 28(P28),on the day when rat's vulva opened in the L group(L-VO),on the day when the first estrous interphase occurred in rats of L group(L-E1),and on the day when the second estrous interphase occurred in rats of L group(L-E2),respectively.RESULITS:On day 34,all rats in the L group,80%of rats in the NS group,40%of rats in the N group,and 20%of rats in the NYPF group showed complete opening of the vulva.At P28,m RNA level of hypothalamic kisspeptin(Kiss-1)in the L group was significantly higher than that in the N group(P<0.05).The rats in the L and NS groups had significantly lower hypothalamic argininephenylalanine-amide(RFamide)-related peptide 3(RFRP-3)m RNA levels than those in the N group(P<0.05),whereas RFRP-3 m RNA level was significantly higher in the NYPF group than that in the L group(P<0.05).At L-VO,the ovarian index of the L and NS groups was significantly higher than that of the N group(P<0.05)and estradiol(E2)level of the NYPF group was significantly lower than that of the N and NS groups(P<0.05);hypothalamic Kiss-1 m RNA level in the L and NS groups was significantly higher than that in the N and NYPF groups(P<0.05),whereas hypothalamic RFRP-3 m RNA level in the L,NYPF,and NS groups was significantly lower than that in the N group(P<0.05).At L-E1,E2 level of the L and NS groups was significantly higher than that of the N group(P<0.01),whereas it was significantly lower in the NYPF group than that of the N,L,and NS groups(P<0.01),and serum luteinizing hormone level of the L and NS groups was significantly higher than that of the N group(P<0.05);levels of serum melatonin and ovarian melatonin receptor 1(MT-1)m RNA in the L,NYPF,and NS groups were significantly lower than those in the N group(P<0.05).At L-E2,the uterine organ index of the NYPF group was significantly lower than that of the L group(P<0.05);and ovarian MT-1 m RNA level of the L and NS groups was significantly lower than that in the N group(P<0.05).CONCLUSIONS:NYPF can delay puberty onset in rats exposed to strong light for a prolonged duration,and regulation of the gene expression of Kiss-1 and RFRP-3 in the hypothalamus has been suggested as one of the mechanisms.

Study on Chrome-free Purging Plugs for Steel Ladles

Purging plug refractories in China typically contain around 3 mass% of super-fine chromium oxide in the matrix in order to improve the performance of the purging plugs, primarily, slag corrosion and wear resistance. Alternatives to chromium oxide containing refractories have gained interest due to health concerns related to the formation of soluble chromium compounds over long storage periods of refractory wastes. Super-ground reactive alumina can replace chromium oxide in purging plug refractories and this paper discussed the new reactive alumina E-SY 88 in comparison to chromium oxide in a typical purging plug castable. The mixing behaviour, wet castable properties, as well as cured, dried, and fired properties at different temperatures up to 1 600 ℃ were compared. In addition, the hot modulus of rupture, creep behaviour, thermal shock resistance and slag corrosion resistance were tested. The microstructure after slag corrosion was investigated by SEM. The results prove that E-SY 88 is an economically viable technical alternative to chromium oxide in purging plug refractories.

Effects of Nano-CaCO_(3)Addition on Properties of Corundum-based Dispersive Purging Plugs

In order to improve the properties of corundum based dispersive purging plugs,dispersive purging plug specimens were prepared using tabular corundum(1-0.15 and≤0.15 mm)as the aggregates,tabular corundum(≤0.044 mm)andα-Al_(2)O_(3)micropowder(d_(50)=0.6μm)as the matrix,Secar 71 cement as the binder,introducing different amounts of nano-CaCO_(3),casting into shapes,and firing at different temperatures(1200 or 1600℃)for 4 h.The effects of the nano-CaCO_(3) extra-addition(0,0.5%,1.0%,1.5%and 2.0%,by mass)on the consistency of the castables as well as the properties and microstructure of the dispersive purging plug specimens were studied.The results show that:(1)with the fixed water addition,the consistency of the corundum castables decreases as the nano-CaCO_(3)addition increases;(2)with the increasing nano-CaCO_(3)addition,the bulk density of the specimens fired at different temperatures for 4 h decreases,the apparent porosity,the cold strength and the hot modulus of rupture all increase,the gas permeability does not change significantly;(3)the specimens fired at 1600℃ for 4 h have obviously better cold comprehensive performance than those fired at 1200℃for 4 h;(4)when the nano-CaCO_(3)addition is 1.5%,the comprehensive performance of the specimen is the optimal.

Effect of Zircon Addition on Properties of Corundum Porous Materials

This paper aims to improve the corrosion resistance of dispersive purging plugs.White fused corundum particles and fine powder,α-Al_(2)O_(3) micropowder,Cr_(2)O_(3) micropowder,Guangxi clay and zircon powder were used as the main raw materials.The mass ratio of white fused corundum particles and fine powder was fixed at 85:15,and 0,1%,2%,or 3%(by mass)of zircon fine powder was added to replace the same amount of white fused corundum fine powder.The corundum porous material was prepared by the particle stacking pore-forming method at 1650℃for 3 h.The effect of the zircon addition on the properties and microstructure of porous materials was investigated.The results show that:after adding zircon,the permeability of the porous material increases,the cold and hot strengths increase obviously,and the expansion rate after firing decreases.When the addition of zircon is 2%,the comprehensive performance of the specimen is optimal with the smallest linear change rate and the highest permeability.

Effects of Freeze/Thaw Cycles and Gas Purging Method on Polymer Electrolyte Membrane Fuel Cells

At subzero temperature, the startup capability and performance of polymer electrolyte membrane fuel cell (PEMFC) deteriorates markedly. The object of this work is to study the degradation mechanism of key components of PEMFC-membrane-electrode assembly (MEA) and seek feasible measures to avoid degradation. The effect of freeze/thaw cycles on the structure of MEA is investigated based on porosity and SEM measurement. The performance of a single cell was also tested before and after repetitious freeze/thaw cycles. The experimental results indicated that the performance of a PEMFC decreased along with the total operating time as well as the pore size distribution shifting and micro configuration changing. However, when the redundant water had been removed by gas purging, the performance of the PEMFC stack was almost resumed when it experienced again the same subzero temperature test. These results show that it is necessary to remove the water in PEMFCs to maintain stable performance under subzero temperature and gas purging is proved to be the effective operation.

PURGING OF BONE MARROWS CONTAMINATED WITH MYELOID LEUKEMIC CELLS BY INTERLEUKIN-2 AND LYMPHOKINE-ACTIVATED KILLER CELLS

The capability of recombinant human interleukin-2 ( rhIL-2) and lymphokine-activated killer (LAK) cells in the purging of normal human bone marrows contaminated with human myeloid leukemic cell lines was evaluated. Mixtures of normal human bone marrow mononuclear cells ( BMC) and K562 cells or HL-60 cells (at the BMCK562 ratio of 200:1, 100:1 or 20:1) were incubated with IL-2 with or without LAK cells at the BMC:LAK ratio of 1:1 for one or three days. The nubmers of residual K562 cells, BFU-E and CFU-GM were examined by clonogenic assays. In 200:1 mixture groups without LAK cells, the number of K562 colonies reduced by 50% with no loss of BFU-E and CFU-GM in one-day cultures, and no K562 colonies formed in three-day cultures with about 20% loss of BFU-E and CFU-GM. If the BMC.K562 ratios were 100:1 or 20:1 in the mktures, the leukemic cells could not be eliminated. When the mixtures were incubated with IL-2 and LAK cells, no leukemic cell colonies were detected in the 20:1 group following one-day

Microstructure and physical properties of steel-ladle purging plug refractory materials

Three different castables were prepared as steel-ladle purging-plug refractory materials： corundum-based low-cement castable （C-LCC）, corundum-spinel-based low-cement castable （C-S-LCC）, and no-cement corundum-spinel castable （C-S-NCC） （hydratable alu- mina p-A1203 bonded）. The properties of these castables were characterized with regard to water demand/flow ability, cold crushing strength （CCS）, cold modulus of rupture （CMoR）, permanent linear change （PLC）, apparent porosity, and hot modulus of rupture （HMoR）. The re- sults show the CCS/CMoR and HMoR of C-LCC and C-S-LCC are greater than those of the castable C-S-NCC. According to the micro- structure analysis, the sintering effect and the bonding type of the matrix material differ among the three castables. The calcium hexaluminate （CA6） phase in the matrix of C-LCC enhances the cold and hot mechanical strengths. In the case of C-S-LCC, the CA6 and 2CaO·2MgO·14A12O3（C2MEA14） ternary phases generated from the matrix can greatly increase the cold and hot mechanical strengths. In the case of the no-cement castable, sintering becomes difficult, resulting in a lower mechanical strength.

Hepatocytes isolated from neoplastic liver-immunomagnetic purging as a new source for transplantation

AIM： To investigate whether hepatocytes isolated from macroscopically normal liver during hepatic resection for neoplasia could provide a novel source of healthy hepatocytes, including the development of reliable protocols for malignant cells removal from the hepatocyte preparation. METHODS： Hepatocytes were procured from resected liver of 18 patients with liver tumors using optimised digestion and cell-enrichment protocols. Suspensions of various known quantities of the HT-29 tumor cell line and patient hepatocytes were treated or not with Ep-CAM-antibody-coated immunomagnetic beads in order to investigate the efficacy of tumor-purging by immunomagnetic depletion, using a semi-quantitative RT-PCR method developed to detect tumor cells. Immunomagnetic bead-treated or bead-untreated tumor cell-hepatocyte suspensions were transplanted intra-peritoneally in Balb/C nude mice to assess the rates of tumor development. RESULTS： Mean viable hepatocyte yield was 9.3×10^6 cells per gram of digested liver with mean viability of 70.5%. Immunomagnetic depletion removed tumor cells to below the RT-PCR detection-threshold of 1 tumor cell in 10^6 hepatocytes, representing a maximum tumor purging efficacy of greater than 400000-fold. Transplanted, immunomagnetic bead-purged tumor cell-hepatocyte suspensions did not form peritoneal tumors in Balb/C nude mice. Co-transplantation of hepatocytes with tumor cells did not increase tumorigenesis of the tumor cells. CONCLUSION： Immunomagnetic depletion appears to be an effective method of purging contaminating tumor cells to below threshold for likely tumorigenesis. Along with improved techniques for isolation of large numbers of viable hepatocytes, normal liver resected for neoplasia has potential as another clinically useful source of hepatocytes for transplantation.

Numerical Simulation of Saline Intrusion and Purging in Long SeaOutfalls with Three-Dimensional Model

Saline intrusion into marine sewage ouffalls will greatly decrease the efficiency of sewage disposal. In order to investigate the mechanisms of this flow, in this paper, a three-dimensional numerical model based on FVM （Finite Volume Method） is established, The RNG κ-ε model is selected for turbulence modeling. The time-averaged vohtme fraction equations are introduced to simulate the stratification and inteffaeial exchange of sewage and seawater in outfalls. Validity of the established three-dimensional numerical model is evaluated by comparisons of numerical results with experimental data. With this three-dimensional numerical model, the internal flow characteristics in ouffalls for different sewage discharges are simulated. The results indicate that for a low sewage discharge, saline circulates in the outfall due to intrusion and both the inflowing momentum and the inteffaeial turbulent mixing are important mechanisms to extrude the saline. For a high sewage discharge, saline intrusion could be avoided. The inflow momentum is the main mechanism to extrude the saline and the inteffacial turbulent mixing is nut important relatively. Even at a high sewage discharge, the saline wedge would be retained in the main ouffall pipe after the risers are purged. It takes a long time for this saline wedge to be extruded by interracial turbulent mixing.

Progress and Developing Trend of Purging Plugs for Refining Ladle

Damage reasons of purging plugs for refining ladle and research progress on thermal shock resistance of corundum- spinel purging plugs were summarized. Research achievements and application results of nonoxides bonded corundum purging plugs for refining ladle were briefly reviewed. The further research and developing trend of purging plugs was proposed.

Effects of Freeze/Thaw Cycles and Gas Purging Method on Polymer Electrolyte Membrane Fuel Cells

At subzero temperature, the startup capability and performance of polymer electrolyte membrane fuel cell PEMFC deteriorates markedly. The object of this work is to study the degradation mechanism of key compo- nents of PEMFC—membrane-electrode assembly MEA and seek feasible measures to avoid degradation. The ef- fect of freezethaw cycles on the structure of MEA is investigated based on porosity and SEM measurement. The performance of a single cell was also tested before and after repetitious freezethaw cycles. The experimental results indicated that the performance of a PEMFC decreased along with the total operating time as well as the pore size distribution shifting and micro configuration changing. However, when the redundant water had been removed by gas purging, the performance of the PEMFC stack was almost resumed when it experienced again the same subzero temperature test. These results show that it is necessary to remove the water in PEMFCs to maintain stable per- formance under subzero temperature and gas purging is proved to be the effective operation.

PURGING OF ACUTE NON-LYMPHOCYTIC LEUKEMIA PROGENITORS BY PROCAINE AND HYPERTHERMIA

Procaine and hyperthermia have been shown to possess a relatively selective cytotoxicity to leukemlc cells. In this study, the combined effects of procaine and hyperthermia on the growth of hematopoietic progenitors (GM-CFU) and ieukemic progenitors (L-CFU) were examined to determine if this combination resulted in a great selective killing of leukemlc cells than that achieved by procaine or heat alone. When the cells were treated simutaneously with procaine (2 mM) and hyperthermia (42℃) for one hour, the killing of L-CFU was enhanced considerably whereas GM-CFU were not markedly affected. These data Indicate that the combined treatment with procain and hyperthermia might offer an efficient mean to selectively purge residual leukemlc cells in vitro. Procaine with hyperthermia may have a role in clinical autoiogous bone marrow transplantation for acute leukemia.

Ongoing Technology and Developing Trend of Ar-blowing Purging Plug

An introduction of the ongoing technology of argon-blowing purging plugs in China was presented in this work. Gel powders were used as starting materials to enhance the high temperature mechanical properties of the purging plugs. Composite purging plug adopting extrusion formed gas-purging bar and slit had its surface structural design improved, which enhanced the resistances to thermal shock and molten steel penetration, prolonging the service life. In addition, the safety was greatly improved by upgrading the framework and production process, enhancing the resistance to breakout. It is indicated that the developing trend is to produce purging plugs of longer service life and better gas purging rate with different starting materials and structure designs to meet the requirements of various metallurgical processes.

Optimization and Application of Corundum-spinel Purging Plugs for Refining Ladles

Corundum - spinel purging plugs were optimized through adjusting the formulation and the particle size composition of starting materials to prolong the service life of purging plugs for a 60 t refining ladle in a steel plant. Th.e optimized formulatioa is 30 mass% tabular corundum （6 - 3 mm ） , 20 mass% tabular corundum （3-1 ram）, 22 mass% tabular corundum （1 -0.5 ram） ＋ sintered spinel, 28% tabular corundum fines （0. 045 mm） ＋ fused spinel （0. 045 mm） ＋ bimodal α-Al2O3 micropowder ＋ Secar71 cement. The on-site results show that the plug can achieve an obviously long service life of 18 cycles, saving cost greatly.

Purging Plugs and Well Blocks for Refining Ladle

1 Scope This standard specifies the classification, technical requirements, test methods, inspection rules, marking, packing, transportation, storage and quality certificate of purging plugs and well blocks for refining ladle.

Numerical investigation on thermomechanical behavior of alumina–calcium hexaluminate refractories for purging plug

Alumina–spinel refractories used in slit-type purging plugs are susceptible to cross-sectional damage,resulting in a serious mismatch between their service life and that of ladle.Alumina–calcium hexaluminate refractories have gradually become the new trend in purging plug materials with the development of refining technology.The thermomechanical damage of slit-type purging plugs with alumina–calcium hexaluminate refractory was investigated by the thermo-solid coupling simulation.Combined with the polynomial fitting and design of experiments methods,the influence of thermophysical parameters on temperature and thermal stress of alumina–calcium hexaluminate refractories for purging plugs was systematically analyzed.The results show that the maximum thermal stress of the purging plugs appears during the stages of steel transporting and stirring,and the vulnerable parts are located above Y=0.323 m.The thermal conductivity and the coefficient of thermal expansion of the material are the most sensitive parameters to the temperature and thermal stress inside the structure,respectively.The addition of more calcium hexaluminate can relieve the stress concentration and large deformation around the slits.Consequently,when the content of calcium hexaluminate is 47 wt.%and in the form of aggregate-binder,the temperature and thermal stress distribution inside the refractory are optimal,which can effectively improve the service life of the slit-type purging plug.

Influence of in situ formed spinel in bonding phase on mechanical properties and air permeability of magnesia-chrome porous purging materials

Magnesia-chrome porous purging plugs are crucial functional components to remove inclusions and stabilize the flow field during iron and steel smelting.However,practical applications of magnesia-chrome porous purging materials are stil hampered by the poor scouring resistance to molten steel and unstable air permeability owing to their low mechanical properties and uncontrollable pore structure.Therefore,the particle-packing type magnesiachrome porous purging materials reinforced by in situ formed spinel were prepared using fused magnesia-chrome particles and Al powders as major raw materials.The results show that in situ formed spinel solid solutions in bonding phase led to the decreased median pore size and increased pore surface fractal dimension from the reactions between Al powders and magnesia-chrome particles and along with high-temperature sintering,bonding between magnesia-chrome particles and the resultant mechanical properties of materials were greatly elevated.Besides,the results of air permeability tests and polynomial ftting indicated that the formation of spinel solid solutions was the main contributing factor for controllable air permeability,and pressure drop of porous purging materials was positively correlated with surface fractal dimension of pores.Moreover,the as-prepared porous purging materials added with 6 wt.%Al powders obtained the maximum cold crushing strength(54.2 MPa)and hot modulus of rupture(12.9 MPa)with median pore size of 24.06μm and ftting non-Darcian permeability coefficient of 0.97×10^(-6)m.

吹扫捕集气相色谱-质谱法定性分析人尿中挥发性有机物

The volatile organic compounds in male and female urine were analyzed using P&T/GC-MS.More than 70 VOCs in samples were identified.Identification of compound were based on NIST05 library and relative references.Compounds in double urines included short-chain alcohols,ketones,aldehyde,sulfether,aliphatic hydrocarbon,aromatic hydrocarbon and chlorinated hydrocarbon.The nicotine in urine was identified.The source of VOCs in urine was briefly discussed in the article.

高速公路两侧农业土壤中挥发性有机化合物污染研究

The pollution of VOCs was studied on both side of highway.With the determination method of purge and trap concentration coupled with gas chromatography-mass spectrometry,we found that the degree of pollution near the highway was not very bad.

一种改进的热流道清洗剂

据“www．ptonline．com，2010年4月”报道，位于纽约州Depew的Shuman塑料公司的Dyna—Purge分公司改进了用于有色料在热流道系统中快速切换的清除剂Dyna-PurgeP的性能。增强的清洗剂配方具有双重净除作用，可以渗入窄狭的通道，使降解产物松动并移除降解产物。该公司称这种新增的净除作用特别适用于有狭窄通道和拐角的老式设备。