Integrated Auto-Tuning PID Control of Continuous Casting Process

Accuratemouldlevelcontrolisveryimportantincontinuouscastingprocess(seeFig.1)anditisbelievedtobeakeyfactorinimprovingfinalproductquality.Althoughmanymethodshavebeendevelopedformouldlevelcontrol[1,2],theyarenotperfectbecauseonlypartofthefactorssuchasdisturbanceofcastingspeedandnonlinearityofthemouldlevelcontrolsystemareconsidered[3—5].Infact,theperformanceofthehydraulicservosystemofslidinggateanddeviationoftundishweightaretwomajorfactorsaffectingmouldlevelcontrol.Allthesetwoloopsshouldbeconside…     

Preparation of Nano Y_2O_2S∶Eu Phosphor by Ethanol Assisted Combustion Synthesis Method

Rareearthoxysulfidematerialsexhibithighlumi nescentefficiencyaswellasexcellentchemicalstabili ty.Thesematerialsarewidelyusedasluminescent hostmaterialsofseveralcommerciallyavailablephos phorssuchasredemittingphosphorsforcolortelevi sionpicturetube,X rayphosphors[1],andlongafter glowpigments[2].Thereexistseveralmethodsinpre paringrareearthoxysulfides:(1)Traditionalsulfide fusionmethod,i.e.sulfurationofrareearthoxidein theflux(Na2CO3K2CO3K3PO4)athighte mperature[3,4],whichiswidelyemployedona…     

Preparation of Lanthanum Nickel Oxide-Coated Ni Sheet Anodes and Their Application to Electrolytic Production of (CF_3)_3N in (CH_3)_4NF·4.0HF Melt

Perfluoroalkylgroup,CF3,promoteslipophilici tyoforganiccompounds,andthereforeperfluorotrim ethylamine,(CF3)3N,isanimportantfluorinesource forthesynthesisofusefulorganicfluorocompoundsas medicinesandagriculturalchemicals,iteasilydecom posestoreleaseCF3radicals.Inaddition,Fukayaet alreportedthat(CF3)3Nisapotentialfiresuppression gasbyabinitiocalculation[1,2].Thiscompoundwas obtainedbyelectrolysisoftrimethylamine,(CH3)3N,dissolvedinanhydrousHFusingNianode[3,4],which iscalledtheSimonsproces…     

Characteristics of Rare Earth Elements of Zircons from Mesozoic Volcanic Rocks in Luanping Region, Hebei

Zircon,whichisrichinU,Thanddeficientincommonlead,andhashighstabilityandthehighest envelopedtemperatureofisotopicsystem[1,2],isan idealisotopicdatingobjectinmagmaticrocks.Inthe recentyears,theLA ICP MSmethod,asanewtest ingmethodwhichhassprangupsincetheendo…     

Synthesis of ZnO∶Dy Nanopowder and Photoluminescence of Dy~ (3+) in ZnO

Thedevelopmentofadvanceddisplayandlight ing technologysuchasfield emissiondisplays(FEDs)andplasmadisplaypanels(PDPs)requiresphosphor whichhasahighefficiencyandcoloredluminescence films.Zincoxide(ZnO)infilmandpowderformsis oneofthemostefficientoxide basedwideband gap phosphormaterials.ZnOischemicallystableandhas moderateconductivitycomparedwithconventionalsul fidephosphormaterials.RE dopedsemiconductorhas applicationsinactivelayers,forexample,thinfilm electro luminescencedevices[1],optoelec…     

Synthesis and Characterization of Terbium-Trimesic Acid Luminescent Complex in Polyvinylpyrrolidone Matrix

Rare earth luminescent complex is one of themost active advanced research fields[1]due to its spe-cial properties[2].It has been the subject of researchfor many years[3 ~6],because of its betterluminescenceproperties , excellent color , and high quantumefficiency[7].It is noted that an appropriate ligand isvery i mportant for i mproving the luminescent prop-erties[8]. Aromatic carboxylic acid has been in focusfor its high symmetry and coordination diversity[9].So ,rare earth aromatic carboxyli…     

Evaluating Acceleration Ability of Electrons of SiO_2 and ZnS in ZnS∶Er Electroluminescence

SinceCoeyandSun[1]discoveredtheinterstitial compoundSm2Fe17Nx,ithasattractedmanyresearch ers′attention.Asakindofpermanentmagneticmate rial,Sm2Fe17Nxexhibitsfairlyhighsaturationmagneti zation(1.54T)[2],highanisotropyfield(14T)under roomtemperatureandhighC…     

Preparation and Characterization of Porous Yttrium Oxide Powders with High Specific Surface Area

Y2O3isoftenusedinthemanufactureofphos phorsandceramics[1～3].However,itisalsousedas selectivecatalysts[1,4,5],suchasforthedehydrationof2alkanols,thedimerizationofmethane,1butene isomerization,hydrogenationof1,3butadieneandac etonealdoladdition,andsupport[6,7]formetalsthat catalyzetheformationofmethanolfromCO2andH2.It iswidelyacceptedthatthecatalysispropertiesofox idesdependstronglyontheirphysicalcharacteristics,especiallyontheirspecificsurfaceareaandporous structure.Agreatdealofattentionhasb…     

Synthesis of YAG∶Ce~(3+) Phosphor by Polyacrylamide Gel Method and Promoting Action of α-Al_2O_3 Seed Crystal on Phase Formation

Cerium activatedyttriumaluminumgarnet Y3Al5O12(YAG∶Ce3+)isknownasanefficientphos phor,whichhasstrongyellowluminescencewhenex citedbybluephotons.Therefore,YAG∶Ceisideally suitedforluminescenceconversionofbluelightemit tingdiodes[1,2],andusedintheassemblingofwhite lightemittingdiode(wLED),sinceblueandyellow arecomplementarycolors.Suchdiodesarenowcom merciallyavailable[2].HighluminancewhiteLEDhas beenarousedattentionaroundworldduetoitslighting withnohydrargyrum,highefficiencyandlonglife.…     

Novel Salt-Assisted Combustion Synthesis of High Surface Area Ceria Nanopowders by An Ethylene Glycol-Nitrate Combustion Process

Ceria and ceria-based powders are candidate ma-terials for a wide range of applications ,for example ,solid electrolytes for solid oxide fuel cells (SOFC)[1],three way catalysts for the treatment of automotive ex-haust gases[2],petroleum-cracking catalyst[3],oxygensensors[4], chemical-mechanical polishing for micro-electronics[5],and UVfilter[6].In recent years , since high surface area ceriananoparticles show superior physical and chemicalproperties to bulk particles , much effort has been …     

Stimulation of P2Y receptors activates c-fos gene expression and inhibits DNA synthesis in cultured cardiac fibroblasts

OBJECTIVES: The aims of this study were to determine (1) whether neonatal rat cardiac fibroblasts (CAFB) express P2Y receptors; (2) whether CAFB respond to extracellular ATP by inducing expression of c-fos mRNA; and (3) whether extracellular ATP modulates norepinephrine (NE)-stimulated cell growth in CAFB. METHODS: Expression of P2Y1 and P2Y2 receptors and induction of c-fos were examined by Northern blot analysis. CAFB growth was assessed by measuring [3H]thymidine incorporation and DNA content. P2Y receptor pharmacology was studied using various ATP analogues. RESULTS: Northern blot analysis of polyA enriched RNA confirmed that at least 2 subtypes of P2Y receptors (P2Y1 and P2Y2) are expressed in cultured CAFB. Extracellular ATP induced the expression of c-fos mRNA through a pathway that was sensitive to inhibitors of protein kinase C (PKC), but not to inhibitors of intracellular Ca2+ signaling. Extracellular ATP inhibited the NE-stimulated increases in DNA content and in [3H]thymidine incorporation into DNA. Whereas the potency order for stimulation of c-fos expression was ATP = UTP > ADP > adenosine, the potency order to inhibit the NE-induced increase of [3H]thymidine incorporation into DNA was ATP > ADP > UTP > adenosine. CONCLUSIONS: These data demonstrate that CAFB express both P2Y1 and P2Y2 receptor mRNA and that CAFB respond to P2Y receptor stimulation by induction of c-fos and inhibition of DNA synthesis. These findings suggest that the effects of ATP on [3H]thymidine incorporation into DNA and on expression of c-fos mRNA are exerted via distinct P2Y receptor subtypes.     

P2Y and P2U receptors differentially release intracellular Ca2+ via the phospholipase c/inositol 1,4,5-triphosphate pathway in astrocytes from the dorsal spinal cord

In astrocytes, raising intracellular Ca2+ concentration is a principal mechanism for transducing extracellular signals following activation of cell-surface receptors. Receptors that may be activated by purine nucleotides, P2 receptors, are known to be expressed by astrocytes from dorsal spinal cord; these astrocytes express two distinct subtypes of P2 receptor, P2Y and P2U. A main goal of the present study was to determine the intracellular signalling pathways mediating the Ca2+ responses produced by stimulating these receptors. Experiments were done using cultured astrocytes from rat dorsal spinal cord. Ca2+ responses were evoked by 2-methylthio-ATP or UTP, nucleotides previously shown to selectively activate P2Y and P2U receptors, respectively, in these cells. P2Y- and P2U-evoked Ca2+ responses were found not to depend upon extracellular Ca2+ and were blocked by thapsigargin, a Ca2+-ATPase inhibitor known to deplete inositol 1,4,5-triphosphate-sensitive Ca2+ stores. Intracellular application of the inositol 1,4,5-triphosphate-sensitive receptor antagonist, heparin, or of the G-protein inhibitor guanosine 5'-O-(2-thiodiphosphate), blocked the P2Y- and P2U-evoked Ca2+ responses. Moreover, the responses were prevented by the phospholipase C inhibitor, U-73122, but were unaffected by the inactive analogue, U-73343. These results indicate that P2Y and P2U receptors on dorsal spinal astrocytes are linked via G-protein coupling to release of intracellular Ca2+ via the phospholipase C/inositol 1,4,5-triphosphate pathway. When we assessed the releasable pools of intracellular Ca2+, by repeated agonist applications in zero extracellular Ca2+, we found that the pool accessed by activating P2U receptors was only a subpool of that accessed by activating P2Y receptors. This implies that there are separable inositol 1,4,5-triphosphate-releasable pools of Ca2+ in dorsal spinal astrocytes and that these may be differentially released by activating distinct metabotropic P2 receptors. This differential release of Ca2+ may be important for physiological as well as pathophysiological events occurring within the spinal cord.     

Comparison of tumor growth between hsp25- and hsp27-transfected murine L929 cells in nude mice

We have developed a novel system for examining the possible contribution of small heat shock proteins (hsp) to tumor growth. L929 fibrosarcoma cells, which do not express significant levels of endogenous hsp25, were stably transfected with either murine hsp25 or human hsp27. Both transfected genes were over-expressed and the respective proteins were phosphorylated in L929 cells. L929 cells transfected with hsp25 exhibited enhanced tumor growth compared to control transfected L929 cells upon s.c. injection into nude mice. In contrast, cells transfected with hsp27 exhibited delayed tumor progression in comparison to controls. Although these 2 heat shock genes and respective proteins are structurally very similar, they apparently exhibit distinct effects on tumor growth in this system.     

Expression of novel genes linked to the androgen-induced, proliferative shutoff in prostate cancer cells

Androgens control cell numbers in the prostate through three separate pathways: (a) inhibition of cell death, (b) induction of cell proliferation (Step-1) and (c) inhibition of cell proliferation (Step-2, proliferative shutoff). The mechanisms underlying these phenomena are incompletely understood. The human prostate carcinoma LNCaP variants express these pathways as follows: LNCaP-FGC express both steps, LNCaP-LNO expresses Step-2, LNCaP-TAC expresses Step-1, and LNCaP-TJA cells express neither step. These cells facilitated the search for mediators of the androgen-induced proliferative shutoff pathway. Androgen exposure for 24 h or longer induced an irreversible proliferative shutoff in LNCaP-FGC cells. The Wang and Brown approach for identifying differentially expressed mRNAs was used to search for mediators of Step-2. Ten unique inserts were identified and from those ten, three genes were further studied. The basal expression of these genes in shutoff-negative variants was not affected by androgen exposure. They were induced by androgens in shutoff-positive LNCaP variants and the androgen receptor-transfected, shutoff-positive, MCF7-AR1 cells. These genes were induced only in the range of androgen concentrations that elicited the shutoff response. Time course analysis showed that their induction precedes the commitment point by 12-18 h. In addition, they were expressed in the normal prostate during proliferative shutoff. These features suggest that the candidate genes have a role in the regulation cascade for proliferative shutoff.     

Specific sequence modifications of a cry3B endotoxin gene result in high levels of expression and insect resistance

Solanum melongena (eggplant) cv. Picentia and the wild species Solanum integrifolium were transformed with both a wild type (wt) and four mutagenized versions of Bacillus thuringiensis (Bt) gene Bt43 belonging to the cry3 class. The Bt gene was partly modified in its nucleotide sequence by replacing four target regions (W: +1 to +170; X: +592 to +1057; Y: +1203 to +1376; Z: +1376 to +1984) with synthetic fragments obtained by polymerase chain reaction amplification of crude oligonucleotides. The synthetic Bt genes were designed to avoid, in their modified regions, sequences such as ATTTA sequence, polyadenylation sequences and splicing sites, which might destabilize the messenger RNA. Furthermore, the codon usage was improved for a better expression in the plant system. The amino acid composition was not altered. Four versions of the modified Bt gene were obtained, BtE, BtF, BtH and BtI, with a nucleotide subtitution percentage of 8.2, 8.6, 14, and 16%, respectively, in comparison to the wt gene Bt43. Modified versions contained different subsets of substituted regions: BtE-W + Z, BtF - Y + Z, BtH-X + Y + Z, BtI - W + X + Y + Z. In the final modified version (BtI), overall guanine+cytosine was increased from the 34.1% of the wt gene to 45.5%, and most of the destabilizing sequences were eliminated. Transgenic plants obtained with the more modified versions, BtH and BtI, were fully resistant to Leptinotarsa decemlineata Say first- and third-instar larvae, while Bt43 wt, BtE and BtF genotypes did not cause mortality and did not affect larval development.     

Inducible expression of suicide genes in Leishmania donovani amastigotes

This study tests the feasibility of using the A2 gene regulatory system to create a Leishmania cell line in which attenuation is developmentally regulated when the parasite differentiates from promastigotes to amastigotes. The Leishmania donovani- inducible A2 gene regulatory system was used to differentially express in amastigotes two potential suicide genes: a truncated version of the L. donovani 3'-nucleotidase/nuclease expressed in the cytoplasm and the herpes simplex virus thymidine kinase gene. These genes were inserted between A2 noncoding regulatory sequences for up-regulation of expression in amastigotes. The accumulation of toxic products affected L. donovani cell replication and viability both in vitro and in vivo. The inducible expression of toxic gene products represents a valuable tool for the development of safe and effective vaccines.     

对比分析黑斑息肉综合征合并大肠癌组织肿瘤基因

Objective: The aim of the study was to screen the differentially expressed genes of Peutz-Jeghers syndrome (PJS) and colorectal carcinoma (CRC). Methods: This study used cDNA microarray to comparatively analyze the gene expression profiles of 4 cases of PJS combined with colorectal adenocarcinoma vs. normal mucosae. The cDNA microarray contained 8064 human genes, and then using RT-PCR to test three genes of all. Results: The experimental data showed that fourteen genes were differentially expressed, which were up-regulated in PJS. Fifty-one genes expressions were altered in CRCs, of which 32 were up-regulated, as compared to the normal mucosae. In addition, 5 genes were similarly altered in both PJS and CRCs. RT-PCR analyses confirmed the cDNA microarray data for three of those genes: LATS2, APC and MADH4. Conclusion: LCN2, USP4, GRO3, HYAL1 and APC - these differentially expressed genes likely represent biomarkers for early detection of CRC and may be potential therapeutic targets.     

Effect of gadolinium incorporation on optical characteristics of YNbO_4：Eu~（3＋） phosphors for lamp applications

Eu3+-doped (Y,Gd)NbO4 phosphor was synthesized by solid-state reaction for possible application in cold cathode fluorescent lamps. A broad absorption band with peak maximum at 272 nm was observed which was due to the charge transfer between Eu3+ ions and neighboring oxygen anions. A deep red emission at the peak wavelength of 612 nm was observed which could be attributed to the 5D0→7F2 transition in Eu3+ ions. The highest luminance for Y1-x-yGdyNbO4:Eux3+ under 254 nm excitation was achieved at Eu3+ concentration of 18 mol.% (x=0.18) and Gd3+ concentration of 8.2 mol.% (y=0.082). The luminance of Y0.738Gd0.082NbO4:Eu3+0.18 was higher than that of a typical commercial phosphor Y2O3:Eu3+ and the CIE chromaticity coordinate was (0.6490, 0.3506), which was deeper than that of Y2O3:Eu3+. The particle size of the synthesized phosphors was controlled by the NaCl flux and particle size as high as 8 μm with uniform size distribution of particles was obtained.     

Treatment of acute herpes simplex encephalitis

Combined subjective and objective nutritional assessment was performed on admission in 127 patients with oral and maxillofacial malignancies. On the basis of the nutritional assessment result, three typical nutritional parameters-body weight (BW) (X1), mid-upper-arm circumference (MAC) (X2), and hand grip strength (HGS) (X3) were used to establish a new nutritional assessment method that was developed by a computer-based discriminant analysis. The established model was as follows: Y1 = -126 + 1.09X1 + 1.34X2 + 0.23X3; Y2 = -95.63 + 0.96X1 + 1.17X2 + 0.19X3. In the model Y1 was regarded as good nutrition and Y2 as malnutrition. The larger value of Y stood for the patient's nutritional status (i.e. Y1 > Y2, well nourished; Y1 < Y2 malnourished). The new nutritional assessment correlates well with the combined subjective and objective nutritional assessment with a total agreement rate of 88.2%. With its simplicity and accuracy, the new nutritional assessment deserves a wide application in clinical situation.