透明质酸的浓度对成纤维细胞黏附和增殖的影响

透明质酸广泛存在于细胞外基质、细胞表面和细胞内部,其独特的理化特性使其具有多种生物学功能。透明质酸对细胞具有多种作用,可以调控细胞生长因子和细胞因子的分泌,抑制蛋白酶的分解,影响细胞的黏附、生长、增殖和分化。本实验将不同浓度的透明质酸加入成纤维细胞培养液中,考察了在培养液中透明质酸的浓度对成纤维细胞的黏附、DNA合成量、糖胺聚糖分泌量和MTT活性的影响。实验结果表明,当培养液中透明质酸的浓度小于0.1%时,对成纤维细胞的黏附和生长增殖有明显的促进作用,当培养液中透明质酸的浓度大于0.1%时,对成纤维细胞的黏附和生长增殖有很强的抑制作用。     

MTT法测定稀土离子对BEL-7402及K562细胞的毒性及增殖毒性

用MTT法测定稀土离子在不同浓度、不同培养液中,与BEL 7402和K562细胞作用不同时间,对细胞的毒性和增殖毒性。结果表明,在含10%小牛血清培养液中,仅个别稀土离子在较高浓度时对BEL 7402细胞增殖有较弱的抑制作用;对于K562细胞,稀土离子在低浓度时对细胞增殖即表现出较强的抑制作用(P<0.05)。当培养液不含小牛血清时,较低浓度的稀土离子即可抑制BEL 7402细胞的增殖(P<0 05)。     

发芽糙米微量元素锌的生物强化

目的发芽糙米的锌生物强化培育及对人体补锌的适用性探讨。方法选取3个品种(吉梗81号、博优209号、黑糯米)的糙米为材料,用不同质量浓度锌培养液(0~250μg·m L-1)浸种24 h(28℃)并发芽36 h(30℃),在萌发过程中实行锌的生物强化,培育富锌发芽糙米。通过测定不同锌含量条件下发芽糙米的萌发参数(吸水率、发芽率),以及锌、Vc和矿物质(Fe、Mn、Mg)含量,探明培养液锌的适宜含量条件和富锌发米糙米的补锌适用性。结果对吉梗81号、博优209号、黑糯米等3个品种,富锌发芽糙米培育的锌培养液适宜质量浓度均为75~150μg·m L-1,最佳质量浓度为100μg·m L-1。3个品种发芽糙米对锌的富集能力由强到弱顺序为:吉梗81号,博优209号,黑糯米。与对照处理(CK)相比,富锌发芽糙米Vc、GABA含量较高,而矿质元素(Fe、Mn、Mg)渗漏损失略低。富锌发芽糙米每10 g(DW)的锌积累量,对吉梗81号、博优209号及黑糯米等3个品种可提供锌占中国成人RNI百分数分别是:53.8%(男性)和89.7%(女性),45.6%(男性)和76.0%(女性),以及41.1%(男性)和68.5%(女性)。结论发芽糙米可能是进行锌生物强化的优良载体,预计富锌发芽糙米适用于人体补锌。     

镧-大肠杆菌毒物兴奋效应机制探索

为了探索培养液中稀土元素镧浓度变化所引发的大肠杆菌生长的毒物兴奋效应(Hormesis)是否会对菌体内其他无机元素吸收量产生影响,并从菌体中无机元素浓度再平衡的角度探讨并验证Hormesis效应的可能发生机制,特以大肠杆菌为实验菌种,在改变培养液中镧浓度的同时用分光光度计监测大肠杆菌的OD值,藉此观察细菌生长动态;用电感耦合等离子体质谱仪(ICP-MS)测定菌体中45种元素含量并借助统计学方法分析上述元素含量与镧浓度以及细菌生长动态之间的相关性。结果显示,培养液中镧元素浓度变化会引发大肠杆菌生长的Hormesis效应,同时导致菌体内无机元素浓度再平衡;菌体内包括锰在内的部分元素含量随着细菌生长速度的加快而升高,由此推测这些元素在一定浓度范围内或许是有益于细菌生长的"益生元素";培养液中添加锰元素后观察到细菌生长进一步加快,从而初步验证了镧-大肠杆菌Hormesis效应的"益生元素上调机制"的假设。     

碘离子胁迫对绿豆萌发过程4种微量元素的影响

用火焰原子吸收法测定绿豆萌发过程中铜、铁、锰和锌的含量,研究不同含量碘离子胁迫对绿豆萌发过程中生理活动的影响。结果显示,各含量培养液所培养的绿豆芽苗中4种元素含量随培养时间的增加而显著降低,适当质量浓度的碘离子(20~80 mg/L)可以促进绿豆对铜、铁、锌的溶出,但碘离子质量浓度过高(100 mg/L)时将抑制绿豆对铜、铁、锰的溶渗出,培养末期绿豆均能从培养液中重新利用铁、锰、锌3种微量元素。     

外源稀土Ce3+对紫背浮萍光合作用和水体富营养化的影响

随着稀土的大量开采、冶炼和应用,导致稀土元素正逐渐由岩石圈向水圈和生物圈转移,由此对水环境很可能造成类同重金属的环境负面效应。基于适量稀土对植物生长的促进作用,以四川境内较为常见且易引起水体富营养化的紫背浮萍为研究对象,运用室内受控实验,观测不同浓度稀土Ce3+对紫背浮萍光合作用的影响,并对紫背浮萍鲜重以及培养液进行了15 d的监测。结果表明较低浓度Ce3+(0.30,0.60 mg.L-1)能提高紫背浮萍叶绿素a的含量和碳酸酐酶活性,促进植物的光合作用,其鲜重均高于空白样(P<0.05),并随着时间推移,培养液中DO含量逐渐下降,COD含量则显示出上升趋势;而较高浓度Ce3+(1.50,3.00 mg.L-1)条件下,紫背浮萍叶绿素a和碳酸酐酶活性明显降低,鲜重低于空白样,光合作用下降,植物生长受到抑制。研究结果可知,水域中适量浓度Ce3+(0～0.60 mg.L-1)可提高水生植物光合作用,加快新陈代谢,进而使水质恶化,促进水体富营养化的发生。     

低剂量氯化镨对体外培养大鼠胰岛β细胞分泌胰岛素的影响

以体外培养的大鼠胰岛细胞为对象，利用放射免疫检测技术，免疫组织化学技术及透射电镜观察低剂量PrCl3对胰岛β细胞分泌胰岛素功能的影响，当PrCl3浓度分别为0．01和0．1mmol.L^-1时，培养液中胰岛素含量及培养孔内β细胞数目明显高于对照组，对体外培养的大鼠胰岛β细胞分泌胰岛素具有促进作用。     

微流控芯片中细胞动态胞吞二氧化硅纳米颗粒的研究

研究了用微流控芯片在体外模拟人体血液流动状态下细胞胞吞二氧化硅纳米粒子的方法和特性. 通过调节储液池的液面差, 使细胞从微通道入口流入并在通道内沉积贴壁生长. 将含有贴壁细胞的微流控芯片放入37 ℃/体积分数5%CO₂的培养箱中, 使细胞培养液连续流过贴壁细胞. 培养24 h后, 在流动的培养液中加入作为荧光标记物的500 nm 粒径的掺杂有异硫氰酸荧光素(FITC)的二氧化硅微球(MSN), 继续培养6 h后, 用荧光显微镜测定细胞胞吞二氧化硅纳米粒子后的荧光强度, 考察了不同流速下细胞对二氧化硅微球摄入量的影响. 结果表明, 在动态条件下, 细胞对二氧化硅微球的吞噬量明显下降, 当流速从0.022 mm/s 增加至0.74 mm/s时, 吞噬量从静态测得值的74.7%下降至7.1%.     

恶性肿瘤患者血清锌与淋巴细胞转化率及自然杀伤细胞活性变化…

观察了８６例恶性肿瘤患者血清锌与淋巴细胞转化及自然伤细胞活性间的变化。结果表明，肿瘤患者的血清锌较正常对照组明显降低，同时伴有淋巴细胞转化率ＮＫ细胞活性下降。表明缺锌是肿瘤患者免疫功能下降的原因之一。     

急性心肌梗塞时血清锌的变化

检查了症状发生后24小时内入院的61例急性心肌梗塞病人的血清锌浓度，其中42例在症状发生后12小时内进行锌浓度测定。其结果提示血清锌浓度在症状发生后的最初3小时内急剧下降，在发病后的最初2至3天血清锌浓度达到最低水平．然后在5至10天内逐渐回复到正常水平，检查结果还提示血清锌显著下降的病人，其临床情况一般比较严重，而且预后较差。因此及时补充锌可能有助于急性心肌梗塞病人的健康恢复。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.