检索结果-南通市图书馆

Increased salt sensitivity induced by sensory denervation: role of superoxide

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第12期25卷 60-66页

作者： Alex f chen,Donna H WANG Department of Medicine and Pharmacology & Toxicology Michigan State University East Lansing MI 48824 USA Department of Medicine and Pharmacology & Toxicology Michigan State University East Lansing MI 48824 USA

AIM: To test the hypothesis that production of superoxide in mesenteric resistance arteries is increased and con- tributes to the development of hypertension induced by sensory denervation plus high salt intake. METHODS: Newborn Wistar rats were given capsaicin 50 mg/kg sc on the 1st and 2nd d of life. After weaning, male rats were grouped as follows and treated for 3 weeks with: capsaicin pretreatment plus normal sodium diet (0.5 %, CAP-NS), CAP plus high sodium diet (4 %, CAP-HS), control plus NS (CON-NS), or CON-HS. Both tail-cuff systolic blood pressure and mean arterial pressure (MAP) were measured in each of the groups. Western blot analysis was used for measurement of manganese superoxide dismutase (MnSOD) and endothelial nitric oxide synthase (eNOS) in the mesenteric resistance arteries. Lucigenin chemiluminescence assay was used for superoxide production in the mesenteric resistance arteries. The Griess method was used for measurement of nitrite/nitrate levels in plasma. RESULTS: Both tail-cuff pressure and MAP were higher in CAP-HS compared with CAP-NS, CON-HS, and CON- NS rats (Pfferent among 4 groups. Acute iv administration of tempol, a membrane-permeable superoxide scavenger, de- creased MAP in both CAP-HS and CON-HS when compared with their respective controls. However, the de- creases of MAP between these two groups were not different. Chronic treatment with tempol failed to prevent the development of hypertension in CAP-HS rats. Superoxideproduction in the mesenteric resistance arteries was increased in CAP-HS compared with CAP-NS, CON-HS, and CON-NS (Pf mesenteric superoxideproduction in CAP-HS rats. CONCLUSIONS: Regardless of increased vascular MnSOD levels, salt

关键词： superoxides tempol afferent neurons capsaicin denervation dietary sodium chloride nitric oxide

fAB MS of Permethylated L-β-Aspartamido-Carbohydrates

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 1998年第2期14卷 52-54,56-58页

作者： WANG Tsong-hui chen T.f. Barofsky D.f. Department of Instrumental Analysis Institute of Forensic ScienceBeijing100038 Department of Agricultural Chemistry Oregon State UniversityCorvallisOregon 97331USA

Native glycopeptides are suitable to fAB mass spectrometric analysis due to their high polarity, low volatility and large molecular size. The deficiency in the fAB spectra of glycopeptides is the limited number of peaks and the low abundances of fragments. In order to obtain the information of carbohydrate sequence the permethylation of carbohydrate, a well known method, is recommended here. The L β aspartamido carbohydrate from chicken egg albumin was chosen as the model compound of glycopeptides. Our experiments showed obvious carbohydrate sequence in the spectra of permethylated aspartamido carbohydrates. The key conditions to perform the method are the methylation reagent and purification process for the permethylated derivatives.

关键词： Glycopeptide Ovalbumin Permethylation fABMS

MICROSTRUCTURE AND INCLUSION CHARACTERIZATION IN THE SIMULATED COARSE-GRAIN HEAT AffECTED ZONE WITH LARGE HEAT INPUT Of A Ti-Zr-MICROALLOYED HSLA STEEL

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2005年第2期18卷 96-106页

作者： Y.T.chen X.chen Q.f.Ding J.Zeng TechnologyCenter WuhanIronandSteel（group）CooperationWuhan430080China

The microstructure and the characteristics of the inclusions embedded in ferrite matrix in simulated coarse-grain heat affected zone (CGHAZ) of a Ti-Zr-treated high strength low alloy (HSLA) steel have been investigated. The microstructure of the simulated CGHAZ dominantly consisted of intragranular acicular ferrite (IAf) combining with a small amount of polygonal ferrite (Pf), widmanst tten ferrite (Wf), bainite ferrite (Bf), pearlite and martensite-austenite (M-A) islands. The Pf, Wf and Bf were generally observed at the prior austenite grain boundaries and the interlocking acicular ferrite was usually found intragranularly. It was found that the inclusions were composed of Ti2O3, ZrO2, Al2O3 locating at the center of the particles and MnS lying on the surface layer of the inclusions. The intragranular complex inclusions promoted the acicular ferrite formation and the refinement of microstructure whilst those at prior austenite grain boundaries caused Pf formation on the inclusions. The simulated CGHAZ consisting of such complicated microstructure exhibited desired mechanical properties.

关键词： microalloyed HSLA steel heat affected zone microstructure mechanical property inclusion acicular ferrite titanium zirconium

Enhanced Mechanical Properties of friction Stir Welded 5083Al-H19 Joints with Additional Water Cooling

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2017年第9期33卷 1009-1014页

作者： B.B.Wang f.f.chen f.Liu W.G.Wang P.Xue Z.Y.Ma School of Mechanical Engineering Liaoning Shihua University Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences

3-mm-thick 5083Al-H19 rolled plates were friction stir welded(fSW) at tool rotation rates of 800 and200 rpm with and without additional water cooling. With decreasing the rotation rate and applying water cooling, softening in the fSW joint was significantly reduced. At a low rotation rate of 200 rpm with additional water cooling, almost no obvious softening was observed in the fSW joint, and therefore a fSW5083Al-H19 joint with nearly equal strength to the base material(BM) was obtained. furthermore, the grains in the nugget zone were considerably refined with reducing the heat input and ultrafine equiaxed grains of about 800 nm were obtained in the lowest heat input condition. This work provides an effective method to achieve high property fSW joints of precipitate-hardened and work-hardened Al alloys.

关键词： friction stir welding Aluminum alloy Water cooling Microstructure Mechanical property

STUDY ON THE TANTALIZING ON THE SURfACE Of TITANIUM ALLOY BY NET-SHAPE CATHODE GLOW DISCHARGING

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 375-379页

作者： f.chen H.Zhou Y.f.Zhang J.D.Pan DepartmentofMechanicalEngineering BeijingInsistuteofPetro-ChemicalTechnologyBeijing102617China DepartmentofMechanicalEngineering BcijingInstituteofGraphicCommunicationBcijing102600China DepartmentofPressandPacking ResearchInstituteofSurfaceEngineeringTaiyuanUniversityofTechnologyTaiyuan030024China

A new net-shape cathode sputtering target which has a simple structure and a hig h sputtering was put forward. The multiple-structure made of alloying and coatin g layers of tantalum was achieved on the surface of TC4 (Ti6Al4V) using this met hod in double glow surface alloying process. The tantalized samples were investi gated by SEM, XRD and electrochemical corrosion method .Results show the complic ated tissue of pure tantalizing layer and diffusion layer was successfully forme d on the surface of TC4 with the method of net-shape cathode glow discharge, whi ch further improved the corrosion-resistance of TC4 and formed good corrosion-re sistant alloys.

关键词： TC4 (Ti6Al4V) cathode sputtering tantalizing

A composite sphere assemblage model for porous oolitic rocks:Application to thermal conductivity

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2017年第1期9卷 54-61页

作者： f. chen A. Giraud D. Grgic K. Kalo Geo Ressources Laboratory Université de Lorraine (ENSG) CNRS CREGU Vandoeuvre-lès-Nancy F-54518 France

The present work is devoted to the determination of linear effective thermal conductivity of porous rocks characterized by an assemblage of grains(oolites) coated by a matrix. Two distinct classes of pores, *** or intra oolitic pores(oolite porosity) and mesopores or inter oolitic pores(inter oolite porosity), are taken into account. The overall porosity is supposed to be connected and decomposed into oolite porosity and matrix porosity. Within the framework of Hashin composite sphere assemblage(CSA)models, a two-step homogenization method is developed. At the first homogenization step, pores are assembled into two layers by using self-consistent scheme(SCS). At the second step, the two porous layers constituting the oolites and the matrix are assembled by using generalized self-consistent scheme(GSCS) and referred to as three-phase model. Numerical results are presented for data representative of a porous oolitic limestone. It is shown that the influence of porosity on the overall thermal conductivity of such materials may be significant.

关键词： Effective thermal conductivity Three-phase model Oolitic limestone Composite sphere assemblage(CSA) model

STUDY Of EXPLOSIVE VAPORIZATION Of LD11R ALUMINUMALLOY DURING ELECTRON BEAM DEEP PENETRATION

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2000年第6期13卷 1119-1124页

作者： Wang, Y.J. Jia, S.J. Liu, f.J. chen, X.f. NKL of EDB process. Technol. Beijing 100024 China

High-power-density electron beam with single pulse was performed on the LD11R aluminum alloy. The electron beam was focused on three typical positions. for each case, the distribution of the solute concentration at the cavity bottom solid-liquid interface was investigated by using the 'rapidly fixing' method. The interaction of the beam and solute atoms was analyzed. A new mechanism of explosive vaporization was proposed based on the present results. The occurrence of this explosive vaporization source was discussed.

关键词： Electron beam welding Vaporization

Genetic targeting of astrocytes to combat neurodegenerative disease

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2020年第2期15卷 199-211页

作者： Rachel Kéry Allen P. f. chen Gregory W. Kirschen Medical Scientist Training Program MSTP)Stony Brook MedicineStony BrookNYUSA Department of Neurobiology & Behavior Stony Brook UniversityStony BrookNYUSA

Astrocytes, glial cells that interact extensively with neurons and other support cells throughout the central nervous system, have recently come under the spotlight for their potential contribution to, or potential regenerative role in a host of neurodegenerative disorders. It is becoming increasingly clear that astrocytes, in concert with microglial cells, activate intrinsic immunological pathways in the setting of neurodegenerative injury, although the direct and indirect consequences of such activation are still largely unknown. We review the current literature on the astrocyte’s role in several neurodegenerative diseases, as well as highlighting recent advances in genetic manipulation of astrocytes that may prove critical to modulating their response to neurological injury, potentially combatting neurodegenerative damage.

关键词： Alzheimer's disease amyotrophic lateral sclerosis glia immune system inflammation Parkinson's disease reactive astrocyte regeneration

Nitric oxide:a newly discovered function on wound healing

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2005年第3期26卷 259-264页

作者： Alex f chen Departments of Pharmacology and Neurology and the Neuroscience Program Michigan State University East Lansing MI 48824-1317 USA

Wound healing impairment represents a particularly challenging clinical problemto which no efficacious treatment regimens currently *** factors ensuringappropriate intercellular communication during wound repair are not *** protein-type mediators are well-established players in thisprocess,emerging evidence from both animal and human studies indicates thatnitric oxide (NO) plays a key role in wound *** beneficial effects of NO onwound repair may be attributed to its functional influences on angiogenesis,inflammation,cell proliferation,matrix deposition,and *** find-ings from in vitro and in vivo studies of NO on wound repair are summarized inthis *** unveiled novel mechanisms support the use of NO-containingagents and/or NO synthase gene therapy as new therapeutic regimens for im-paired wound healing.

关键词： angiogenesis inflammation nitric oxide proliferation wound healing