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301.
阐述了"环境工程原理"课程建设的重要性、课堂教学的内容与方式,以及该课程实践的发展和实施情况。 相似文献
302.
Emerging topics and new perspectives on HLA-G 总被引:1,自引:1,他引:0
Fainardi E Castellazzi M Stignani M Morandi F Sana G Gonzalez R Pistoia V Baricordi OR Sokal E Peña J 《Cellular and molecular life sciences : CMLS》2011,68(3):433-451
Following the Fifth International Conference on non-classical HLA-G antigens (HLA-G), held in Paris in July 2009, we selected
some topics which focus on emerging aspects in the setting of HLA-G functions. In particular, HLA-G molecules could play a
role in: (1) various inflammatory disorders, such as multiple sclerosis, intracerebral hemorrhage, gastrointestinal, skin
and rheumatic diseases, and asthma, where they may act as immunoregulatory factors; (2) the mechanisms to escape immune surveillance
utilized by several viruses, such as human cytomegalovirus, herpes simplex virus type 1, rabies virus, hepatitis C virus,
influenza virus type A and human immunodeficiency virus 1 (HIV-1); and (3) cytokine/chemokine network and stem cell transplantation,
since they seem to modulate cell migration by the downregulation of chemokine receptor expression and mesenchymal stem cell
activity blocking of effector cell functions and the generation of regulatory T cells. However, the immunomodulatory circuits
mediated by HLA-G proteins still remain to be clarified. 相似文献
303.
Comino-Méndez I Gracia-Aznárez FJ Schiavi F Landa I Leandro-García LJ Letón R Honrado E Ramos-Medina R Caronia D Pita G Gómez-Graña A de Cubas AA Inglada-Pérez L Maliszewska A Taschin E Bobisse S Pica G Loli P Hernández-Lavado R Díaz JA Gómez-Morales M González-Neira A Roncador G Rodríguez-Antona C Benítez J Mannelli M Opocher G Robledo M Cascón A 《Nature genetics》2011,43(7):663-667
Hereditary pheochromocytoma (PCC) is often caused by germline mutations in one of nine susceptibility genes described to date, but there are familial cases without mutations in these known genes. We sequenced the exomes of three unrelated individuals with hereditary PCC (cases) and identified mutations in MAX, the MYC associated factor X gene. Absence of MAX protein in the tumors and loss of heterozygosity caused by uniparental disomy supported the involvement of MAX alterations in the disease. A follow-up study of a selected series of 59 cases with PCC identified five additional MAX mutations and suggested an association with malignant outcome and preferential paternal transmission of MAX mutations. The involvement of the MYC-MAX-MXD1 network in the development and progression of neural crest cell tumors is further supported by the lack of functional MAX in rat PCC (PC12) cells and by the amplification of MYCN in neuroblastoma and suggests that loss of MAX function is correlated with metastatic potential. 相似文献
304.
305.
Action mechanisms of a new erythrocyte-derived depressing factor 总被引:4,自引:0,他引:4
Fig. . Effect of CHCl 《科学通报(英文版)》2000,45(23):2113-2118
To investigate the action mechanisms of a new erythrocyte-derived depressing factor (EDDF), the focus is placed on the effect
of EDDF on both cytosolic and nuclear free calcium (Ca2+) transportation in vascular smooth muscle cell (VSMC), as well as the apoptosis and cell cycle of VSMC of rats. EDDF has
been extracted from human erythrocytes. The changes of Ca2+ levels in cytoplasm ([Ca2+]i) and nucleus ([Ca2+]n) have been observed using a laser scanning confocal microscope together with fluo-3/AM as a calcium indicator. Flow cytometric
technique was used to study the effect of EDDF on cell cycle and apoptosis of VSMC. [Ca2+], and [Ca2+]n were significantly decreased through several different pathways: ( i ) it reduced the Ca2+ influx by blocking L-type voltage-dependent calcium channel (L-VDC) and R-type voltage-dependent calcium channel (R-VDC);
(ii) it inhibited the Ca2+ release from inositol 1, 4, 5-trisphosphate (IP3) sensitive calcium store; and (iii) activated Ca2+-ATPase of sarcoplasmic reticulum (SR) and promoted the transportation of Ca2+ from cytoplasm to SR. However, EDDF seemed to have little inhibitory effect on the Ca2+ release from ryonodine sensitive calcium pool. It was also found that EDDF (10−4 g/mL) significantly decreased the proportion of S phase of human umbilical vein (HUV) and inhibited the proliferation of
VSMC induced by angiotensin II (Angll, 10−5 mol/L). The apopotosis did not occur when VSMC was cultured under normal condition. While VSMC apoptosis was induced by Angll
(10−5 mol/L) and EDDF (10−4 g/mL) seemed to have little effect on it. The inhibitory effect of EDDF on the elevation of [Ca2+]i and [Ca2+]n of VSMC might play an essential role in its action mechanisms and the ways it affects the Ca2+ handling of VSMC demonstrate that EDDF was different from other endogenous blood pressure regulators and some known antihypertensive
drugs. EDDF could inhibit the proliferation of VSMC, which indicated that it might be beneficial to the prevention and treatment
of hypertension and arteriosclerosis. 相似文献
306.
Fig. . Chemical structure of biotinylated cyclicRGD-containing hexapeptide with different spacer lengths. 《科学通报(英文版)》2000,45(23):2148-2151
The RGD sequence generally exists in the extracellular matrix proteins and can be recognized by many integrin proteins. The
binding ability of immobilized biotinylated cyclic hexapeptide [cyclo(-Arg-Gly-Asp-D-Phe-Lys-Gly-)] containing RGD to integrin
ααbβ3 was tested by the methods of ELISA and SPR. Results showed that a spacer of 1.48–2.2 nm between the peptide and the biotin
residue was long enough to send the RGD sequence into the binding center embccedded within αIIbβ3, and the equilibrium dissociation constant was 1.1 μm. The work provides an ideal model system for the research of cell adhesion
on solid surfaces. 相似文献
307.
晚更新世末期东亚季风活动与陆架区沉积环境变迁 总被引:3,自引:0,他引:3
从距今18000年的最后冰期最盛时期到距今10000年开始的全新世海侵,全球气候发生过急剧的变化。位于亚洲东部的古季风活动也经历了盛衰变化。大量的钻孔及浅地层剖面分析资料已经证实,冰期最盛时期陆架区古季风活动加强,陆架出现了沙漠环境与黄土沉积。当冰期结束,气候转暖,冬季风减弱之际,南黄海陆架及长江三角洲一带的沙漠与黄土分布范围也随之缩小,原先的沙漠活动区变成了黄土分布区,也就是所谓硬粘土沉积区。随着古季风活动的进一步衰退和海面的不断升高,来自陆架区的东北风变为冷湿气流。长江三角洲地区和陆架上出现了有利于沼泽发育的环境,全新世海侵把泥炭层淹没。陆架区晚更新世末期以来的地层中出现沙层、硬粘土和泥炭层的沉积序列,即“三元沉积结构”,是古季风盛衰过程的最好记录。 相似文献
308.
A.Penzkofer A.Tyagi T.Susdorf D.del Agua O.García R.Sastre A.Costela I.García-Moreno 《复旦学报(自然科学版)》2007,(5)
1 Results The development of tuneable solid-state organic dye lasers is a subject of considerable interest and research activity.Compared to conventional liquid dye lasers they have the advantage of being free of solvent handling,having small size,and being easy to operate.For high-performance solid-state dye lasers highly photo-stable dyes with low quantum yield of triplet formation and low triplet-triplet absorption cross-section in the lasing wavelength region are required.For solid state dye lasers organic molecules have been incorporated in inorganic glasses (mainly sol-gel glasses),in organic polymer matrices,and into hybrid compositions of inorganic-organic hosts.Here samples of the BODIPY dye (dipyrromethene-BF2 dye) PM597 incorporated in copolymers resembling inorganic-organic hybrid matrices are characterized by optical spectroscopic methods towards their application as solid-state laser rods.The inorganic function is entered by the constituent 3-(trimethoxysilyl)propyl methacrylate (TMSPMA).The organic constituents are monomers with one polymerizable group [methyl methacrylate (MMA),or 2-hydroxyethyl methacrylate (HEMA)],two [ethylene glycol dimethacrylate (EGDMA)],three [pentaerythriol triacrylate (PETA)],and four [pentaerythriol tetraacrylate (PETRA)] polymerizable groups.The copolymers were obtained by radical bulk polymerization with 2,2'-azobis(isobutyronitrile) (AIBN) as polymerization initiator.TMSPMA and MMA were also copolymerized by "in-situ" and simultaneous hydrolysis-condensation of the methoxy groups of TMSPMA during the free radical polymerization of MMA using AIBN in order to fully approach a sol-gel inorganic glass-organic polymer hybrid solid-state dye laser material.Structural and thermo-mechanical studies (thermogravimetry,differential scanning calorimetry,and infrared spectroscopy) revealed the highest thermo-mechanical stability for high-degree inter-crossing copolymerisation [COP(TMSPMA-PETA),COP(TMSPMA-PETRA)] and hydrolysis-polymerization [COPH(MMA-TMSPMA)].Concerning the optical spectroscopy characterisation,all studied PM597 doped copolymer samples exhibited high fluorescence quantum yields (60 % to 70 %),negligibly small excited-state absorption cross-sections (5% to 10 % of ground-state absorption at 527 nm),and high photo-stability (typically up to 3 million excitation cycles before degradation after some initial fading).The laser properties of the PM597 doped copolymers were evaluated by transversal pumping with 6 ns laser pulses of 5.5 mJ energy at 532 nm.Most of the studied samples surpassed 100 000 laser shots with no or only less than 50 % of laser output power reduction. 相似文献
309.
310.
经典的建立化学反应方程式的方法有积分法、微分法、半衰期法等。这些方法计算工作量大,并且误差大。使用微型电子计算机建立化学反应动力学方程式,计算方法简便,计算结果准确。 相似文献