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.

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 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.

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.

Adjuncts to colonic cleansing before colonoscopy

Pre-procedural cleansing of the bowel can maximize the effectiveness and efficiency of colonoscopy.Yet,efficacy of the current gold standard colonic preparation method-high-volume oral administration of purgative agents 12-24 h prior to the procedure-is limited by several factors,such as patient compliance(due to poor palatability and inconvenience of the dosing regimen)and risks of complications(due to drug interactions or intolerance).Attempts to resolve these limitations have included providing adjunctive agents and methods to promote the colonic cleansing ability of the principal purgative agent,with the aim of lessening unpleasant side effects(such as bloating)and reducing the large ingested volume requirement.Several promising adjunctive agents are bisacodyl,magnesium citrate,senna,simethicone,metoclopramide,and prokinetics,and each are being investigated for their potential.This review provides an up to date summary of the reported investigations into the potencies and weaknesses of the key adjuncts currently being applied in clinic as supplements to the traditional bowel preparation agents.While the comparative analysis ofthese adjuncts showed that no single agent or method has yet achieved the goal of completely overcoming the limitations of the current gold standard preparation method,they at least provide endoscopists with an array of alternatives to help improve the suboptimal efficacy of the main cleansing solutions when used alone.To aid in this clinical endeavor,a subjective grade was assigned to each adjunct to indicate its practical value.In addition,the systematic review of the currently available agents and methods provides insight into the features of each that may be overcome or exploited to create novel drugs and strategies that may become adopted as effective bowel cleansing adjuncts or alternatives.

Change in renal function after sodium phosphate preparation for screening colonoscopy

AIM:To investigate the changes in renal function at 12-24 mo in patients following sodium phosphate(NaP) preparation for screening colonoscopy.METHODS:We carried out a retrospective study on the results from patients who received health check-up services as part of an employer-provided wellness program performed between August 2006 and May 2008 and who were followed up for 12-24 mo.Prior to screening colonoscopy,224 patients underwent bowel cleansing with NaP(NaP group) and 113 patients with polyethylene glycol(PEG group).The control group comprised 672 age-matched patients.We compared the changes in the creatinine levels and the glomerular filtration rates(GFRs) from baseline to 12-24 mo between the NaP,PEG,and control groups using two-way repeated measured analysis of variance.In addition,multivariate linear regression analysis was performed to assess the risk factors for a decreased GFR.RESULTS:The baseline mean serum creatinine level in the NaP,PEG,and control groups was 1.12 ± 0.15,1.12 ± 0.16,and 1.12 ± 0.15 mg/dL,which increased to 1.15 ± 0.15,1.15 ± 0.18,and 1.15 ± 0.15 mg/dL,respectively,after 12-24 mo.The baseline mean GFR in the NaP,PEG,and control groups was 69.0 ± 7.7,68.9 ± 8.0,and 69.6 ± 6.7 mL/min per 1.73 m2,which decreased to 66.5 ± 7.8,66.5 ± 8.3,and 67.4 ± 6.4 mL/min per 1.73 m2,respectively,after 12-24 mo.The changes in serum creatinine levels and GFRs were not significantly between the NaP,PEG,and control groups(P = 0.992 and P = 0.233,respectively).Using multivariate linear regression analysis,only the baseline GFR was associated with the change in GFR(P < 0.001).Indeed,the bowel preparations were not associated with the change in GFR(P = 0.297).CONCLUSION:NaP bowel preparation in subjects with normal renal function was not associated with renal injury,and NaP can thus be used safely for screening colonoscopy.

Multicenter,randomized study to optimize bowel for colon capsule endoscopy

AIM To assess the cleansing efficacy and safety of a new Colon capsule endoscopy(CCE) bowel preparation regimen.METHODS This was a multicenter,prospective,randomized,controlled study comparing two CCE regimens. Subjects were asymptomatic and average risk for colorectal cancer. The second generation CCE system(Pill Cam? COLON 2;Medtronic,Yoqneam,Israel) was utilized. Preparation regimens differed in the 1 st and 2 nd boosts with the Study regimen using oral sulfate solution(89 m L) with diatrizoate meglumine and diatrizoate sodium solution("diatrizoate solution")(boost 1 = 60 m L,boost 2 = 30 m L) and the Control regimen oral sulfate solution(89 m L) alone. The primary outcome was overall and segmental colon cleansing. Secondary outcomes included safety,polyp detection,colonic transit,CCE completion and capsule excretion ≤ 12 h. RESULTS Both regimens had similar cleansing efficacy for the whole colon(Adequate: Study = 75.9%,Control = 77.3%;P = 0.88) and individual segments. In the Study group,CCE completion was superior(Study = 90.9%,Control = 76.9%;P = 0.048) and colonic transit was more often < 40 min(Study = 21.8%,Control = 4%;P = 0.0073). More Study regimen subjects experienced adverse events(Study = 19.4%,Control = 3.4%;P = 0.0061),and this difference did not appear related to diatrizoate solution. Adverse events were primarily gastrointestinal in nature and no serious adverse events related either to the bowel preparation regimen or the capsule were observed. There was a trend toward higher polyp detection with the Study regimen,but this did not achieve statistical significance for any size category. Mean transit time through the entire gastrointestinal tract,from ingestion to excretion,was shorter with the Study regimen while mean colonic transit times were similar for both study groups.CONCLUSION A CCE bowel preparation regimen using oral sulfate solution and diatrizoate solution as a boost agent is effective,safe,and achieved superior CCE completion.

A critical review on Nepal Dock(Rumex nepalensis):A tropical herb with immense medicinal importance

Rumex nepalensis Spreng.(Polygonaceae) commonly known as Nepal Dock has wide-spectrum therapeutic potencies and is extensively used for centuries in traditional medicine systems. The leaves of this plant are edible and a rich source of natural antioxidants. They act as a possible food supplement and are largely used in pharmaceutical industry. Extracts and metabolites from this plant exhibits pharmacological activities including anti-inflammatory, antioxidant, antibacterial, antifungal, antiviral, insecticidal, purgative, analgesic, antipyretic, anti-algal, central nervous system depressant, genotoxic, wound healing and skeletal muscle relaxant activity. Due to its remarkable biological activities, it has the potential to act as a rich source of drug against life threatening diseases. However, more studies are needed to scientifically validate the traditional uses of this plant, beside isolating and identifying their active principles and characterizing the mechanisms of action. We present herein a critical account of its botany, ecology, traditional uses, phytoconstituent profile and major pharmacological activities reported in recent years and therefore will provide a source of information on this plant for further studies.

Methanol extract of Tephrosia vogelii leaves potentiates the contractile action of acetylcholine on isolated rabbit jejunum

Objective:To investigate the modulating role of methanol extract of Tephrosia vogelii leaves on acetylcholine(ACh)-induced contraction of isolated rabbit jejunum.Methods: Rabbit jejunum segment was removed and placed in an organ bath containing Tyrode's solution, and its contractions were recorded isometrically.Results: ACh(2.0 × 10-10 g/m L) and the extract(2.0 × 10-4 g/m L) individually increased the frequency of contraction(mean ± SEM) of the isolated smooth muscle tissue by 47.6% ± 9.5% and 77.8% ± 66.5%, respectively. When ACh and the extract were combined, the frequency of contraction of the tissue was increased by 222.2% ± 25.9%, representing a 366.7% increase(P < 0.001) over the effect of ACh alone. Similarly, ACh(2.0 × 10-9 g/m L) and the extract individually increased significantly(P < 0.001) the amplitude of contraction of the tissue by 685.7% ± 61.1% and 455.2% ± 38.1%, respectively. When ACh and the extract were combined, the amplitude of contraction of the tissue rose by 1263.8% ± 69.0%, representing 84.3% increase over the ef ect of ACh alone. Conclusions: The findings demonstrate that methanol extract of Tephrosia vogelii leaves potentiates the contractile ef ect of ACh on intestinal smooth muscle, supporting the traditional claim that the plant is purgative.

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。

耐高热的清机料

据“www．ptonline．com”报道，纽约州迪普舒曼塑料有限公司Dyna—Purge Div．开发出一种新型清洗吹扫耐高温热塑性塑料清机料Dyna—Purge E2。2013年12月俄亥俄州阿克伦大学高分子科学与高分子工程研究所对该材料进行独立研究，

AutoCAD文件的压缩

本文简单叙述了精减AutoCAD文件大小的二种方法,并对此进行了比较。

运用低温Purge降低LPCVD氮化硅工艺的微粒污染

LPCVD制备的氮化硅薄膜具有良好的阶梯覆盖性,但是这种薄膜的应力偏高,在石英工艺腔管使用到8μm后易形成剥落微粒。特别是半导体工艺发展到了亚微米阶段,这一问题对于产品良率的影响也越来越大。文中以垂直式LPCVD设备为研究对象,通过利用晶圆冷却时间,运用降低工艺腔体温度并使用N2Purge的方法来改善微粒状况。通过大量对比实验来得出最优温度设定。运用这种方式不但改善了LPCVD设备制备氮化硅膜的微粒状况,还延长了设备的维护周期,增加设备利用时间。

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.

Sequential analysis of dimethyl sulfur compounds in seawater

A sequential method for the determination of dimethyl sulfur compounds, including dimethylsulfide （DMS）, dimethylsulfonio- propionate （DMSP） and dimethylsulfoxide （DMSO）, in seawater samples has been developed. Detection limit of 2.5 pmol of DMS in 25 mL sample, corresponding to 0.10 nmol/L, was achieved. Recoveries for dimethyl sulfur compounds were in the range of 68.6- 78.3%. The relative standard deviations （R.S.D.s） for DMS, DMSP and DMSO determination were 3.0, 5.4 and 7.4%, respectively.

人胎肝低分子天然抑瘤物体外培养净化自体骨髓移植治疗急性白血病的研究

本文对17例急性白血病患者,在完全缓解期采用LMW-NTS体外培养净化后进行了自体骨髓移植,其中急性髓细胞白血病14例,急性淋巴细胞白血病3例。预处理以环磷酰胺和全身照射为主。移植后来接受抗白血病治疗,随访观察15至45个月,11例无病生存≥+15月,8例≥+24月,5例≥+30月,最长1例为+43月。5例在+6-+22月复发。1例在+6月猝死。统计3.5年无病生存率为62.7％士15.0％。

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.

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

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.