期刊文献+
共找到3,561篇文章
< 1 2 179 >
每页显示 20 50 100
Synthesis, Structure and Quantum Mechanical Calculations of Methyl 2-(5-((Quinolin-8-yloxy)-methyl)-1,3,4-oxadiazol-2-ylthio)-acetate
1
作者 AAMER SAEED FOUZIA PERVEEN +2 位作者 NAEEM ABBAS SIDRA JAMAL ULRICH FL?RKE 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第6期858-870,共13页
The title compound was synthesized by the base catalyzed reaction of 5-((quinolin- 8-yloxy)methyl)-1,3,4-oxadiazole-2(3H)-thione with methyl chloroacetate. The structure was supported by the spectroscopic data a... The title compound was synthesized by the base catalyzed reaction of 5-((quinolin- 8-yloxy)methyl)-1,3,4-oxadiazole-2(3H)-thione with methyl chloroacetate. The structure was supported by the spectroscopic data and unambiguously confirmed by single-crystal X-ray diffraction studies. It crystallizes from a methanol solution in the triclinic space group Pi with unit cell dimensions a = 7.4509(9), b = 10.2389(12), c = 12.2299(15)A, a = 74.771(2), β = 77.956(2), 7 = 69.263(2)°, V = 834.98(17) A3 and Z = 2. In order to gain some valuable insights into the molecular structure, the quantum mechanical calculations were performed using both HF and time-dependent density functional theory at the B3LYP/6-31G(d,p) level. The molecular geometry from X-ray determination of the title compound in the ground state has been compared using the Hartree-Fock (HF) and density functional theory (DFT) with the 6-31G(d) basis set. The calculated results show that the DFT and HF can well reproduce the structure of the title compound. The energetic behavior of the title compound was examined using the B3LYP method with the 6-31G(d) basis set. The harmonic vibrational frequencies calculated have been compared with the experimental FTIR and FT-Raman spectra. The restricted Hartree-Fock and density functional theory-based nuclear magnetic resonance (NMR) calculation procedure was also performed, and it was used for assigning the 13C and 1H NMR chemical shifts of the title compound. Moreover, molecular electrostatic potential and thermodynamic parameters of the title compound were investigated by theoretical calculations. 展开更多
关键词 methyl 2-(5-((quinolin-8-yloxy)methyl)-1 3 4-oxadiazol-2-ylthio)acetate CRYSTALSTRUCTURE CONFORMER quantum chemical calculations vibrational studies
在线阅读 下载PDF
Synthesis and Crystal Structure of Methyl 2-(Diphenylamino)-4-phenyl-1,3-thiazole-5-carboxylate
2
作者 Ali Souldozi Seyed Hamid Reza Shojaei +2 位作者 Ali Ramazani Katarzyna lepokura Tadeusz Lis 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第1期82-88,共7页
The title compound, methyl 2-(diphenylamino)-4-phenyl-1,3-thiazole-5-carboxylate, was synthesized and studied by single-crystal X-ray diffraction method. The structure of the product was confirmed by IR, 1H- and 13C... The title compound, methyl 2-(diphenylamino)-4-phenyl-1,3-thiazole-5-carboxylate, was synthesized and studied by single-crystal X-ray diffraction method. The structure of the product was confirmed by IR, 1H- and 13C-NMR spectroscopy and elemental analysis. These experimental studies were supported by quantum mechanical calculations. The structure was solved in monoclinic, space group P21/c with a = 9.573(3), b = 19.533(7), c = 9.876(3), β = 92.35(4)°, V = 1845.2(10)3, T = 85(2) K, Z = 4, R = 0.040 and wR = 0.089 for 6424 observed reflections with I2σ(I). 展开更多
关键词 single-crystal X-ray structure multi-component reaction methyl 2-(diphenylamino)-4-phenyl-1 3-thiazole-5-carboxylate benzoyl isothiocyanate DIPHENYLAMINE dimethyl acetylenedicarboxylate
在线阅读 下载PDF
Syntheses and Crystal Structures of Methyl 2-(4,5-Dibromo-1-methylpyrrole-2-carbonylamino)-3-phenylpropanoate and 4,5-Dibromo-1-methyl-2- trichloroacetylpyrrole
3
作者 ZENG Xiang-Chao GU Jian XU Shi-Hai LIU Po-Run 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第2期153-158,共6页
4,5-Dibromo-1-methyl-2-trichloroacetylpyrrole Ⅰ, prepared by the reaction of 1-methyl-2-trichloroacetylpyrrole with Br2 in 98.6 % yield, was condensed with methyl L-2-amino-3- phenylpropanoate to afford methyl 2-(4,... 4,5-Dibromo-1-methyl-2-trichloroacetylpyrrole Ⅰ, prepared by the reaction of 1-methyl-2-trichloroacetylpyrrole with Br2 in 98.6 % yield, was condensed with methyl L-2-amino-3- phenylpropanoate to afford methyl 2-(4,5-dibromo-1-methylpyrrole-2-carboxmido)-3-phenylpropanoate Ⅱ in 90.8% yield. Crystal data for Ⅰ: monoclinic system, space group P21/c with a = 8.595(3), b = 10.900(4), c = 12.321(5) ,A°,β = 92.292(7)°, V = 1153.4(8)A°^3, Dc = 2.213 g/cm^3, F(000) = 728, CTH4Br2Cl3NO, Mr = 384.28, λ = 0.71073 A°, μ(MoKa) = 7.688 mm^-1, Z = 4, R = 0.0338 and wR2 = 0.0840 for 1963 observed reflections with I 〉 2a(I). Crystal data for Ⅱ: monoclinic system, space group P21 with a = 4.886(2), b = 15.921(8), c = 11.635(6) A°,β = 101.803(9)°, V = 885.9(7) A°^3, Dc = 1.665 g/cm^3, F(000) = 440, C16H16Br2N2O3, Mr = 444.13, λ = 0.71073 A°, μ(MoKa) = 4.590 mm^-1, Z = 2, R = 0.0335 and wR2 = 0.0837 for 3191 observed reflections with I 〉 2σ(I). The crystal structure reveals that compound Ⅱ forms the one-dimensional chain structure via the intermolecular hydrogen bonds of N(2)-H…O(1). 展开更多
关键词 methyl 2-(4 5-dibromo-1-methylpyrrole-2-carbonylamino)-3-phenylpropanoate synthesis crystal structure 4 5-dibromo-1-methyl-2-trichloroacetylpyrrole
在线阅读 下载PDF
Ce掺杂TiO_(2)-SnO_(2)粉体的制备、表征及光催化降解甲基红研究
4
作者 周树年 唐小强 +1 位作者 张贞发 赵汉民 《广东化工》 2026年第1期13-16,共4页
以四氯化锡(Ⅳ)五水化合物、钛酸四丁酯作为前驱体,以硝酸铈作为Ce源,采用溶胶凝胶法-共沉淀法相结合制备Ce掺杂TiO_(2)-SnO_(2)粉体。用甲基红模拟污染物作为目标降解物,以污染物的降解率作为光催化性能的主要评价指标,考察了SnO_(2)... 以四氯化锡(Ⅳ)五水化合物、钛酸四丁酯作为前驱体,以硝酸铈作为Ce源,采用溶胶凝胶法-共沉淀法相结合制备Ce掺杂TiO_(2)-SnO_(2)粉体。用甲基红模拟污染物作为目标降解物,以污染物的降解率作为光催化性能的主要评价指标,考察了SnO_(2)摩尔分数、Ce掺杂量、光照时间等因素对光催化性能的影响。用扫描电镜(SEM)、X射线衍射(XRD)、拉曼光谱、紫外-可见漫反射光谱(UV-Vis DRS)对材料进行表征。实验结果表明,当Sn^(4+)复合比为10.00%、Ce^(4+)掺杂比为1.00%时材料呈现最优形貌与晶相结构;Ce掺杂样品在波段>420nm的光响应增强;LED光照下搅拌时间4 h,对0.050 g/L甲基红溶液的降解效率最高,为76.78%。 展开更多
关键词 CE掺杂 TiO_(2)-SnO_(2)粉体 制备与表征 光催化 甲基红
在线阅读 下载PDF
复合光催化剂Bi_(12)O_(17)Cl_(2)/TiO_(2)制备及其性能
5
作者 殷榕灿 胡丹丹 崔玉民 《工程科学学报》 北大核心 2026年第1期62-71,共10页
在室温条件下,利用BiCl_(3)·5H_(2)O、NaOH和CH_(3)CH_(2)OH作原料合成了Bi_(12)O_(17)Cl_(2)光催化剂.把TiO_(2)与Bi_(12)O_(17)Cl_(2)通过机械混合法进行复合,制备Bi_(12)O_(17)Cl_(2)/TiO_(2)复合光催化剂.通过改变Bi_(12)O_(17... 在室温条件下,利用BiCl_(3)·5H_(2)O、NaOH和CH_(3)CH_(2)OH作原料合成了Bi_(12)O_(17)Cl_(2)光催化剂.把TiO_(2)与Bi_(12)O_(17)Cl_(2)通过机械混合法进行复合,制备Bi_(12)O_(17)Cl_(2)/TiO_(2)复合光催化剂.通过改变Bi_(12)O_(17)Cl_(2)在Bi_(12)O_(17)Cl_(2)/TiO_(2)中的质量分数,分别考察Bi_(12)O_(17)Cl_(2)/TiO_(2)和TiO_(2)在紫外光和可见光条件下,对甲基橙的光催化降解效率.研究发现,当用紫外光照射1.25 h时,3%Bi_(12)O_(17)Cl_(2)/TiO_(2)催化剂的紫外光催化活性最高,3%Bi_(12)O_(17)Cl_(2)/TiO_(2)光催化降解甲基橙的降解效率为100%.当用可见光照射2 h时,3%Bi_(12)O_(17)Cl_(2)/TiO_(2)催化剂的可见光催化活性最高,3%Bi_(12)O_(17)Cl_(2)/TiO_(2)光催化降解甲基橙的降解率为90%.当用可见光照射2 h时,3%Bi_(12)O_(17)Cl_(2)/TiO_(2)光催化降解甲基橙溶液的COD(Chemical oxygen demand)去除率最高,其COD去除率为75%.通过对Bi_(12)O_(17)Cl_(2)/TiO_(2)光催化反应机理研究表明,TiO_(2)有比Bi_(12)O_(17)Cl_(2)更负的导带值,TiO_(2)也具有比Bi_(12)O_(17)Cl_(2)更正的价带值.在光照条件下,位于二氧化钛导带上的电子,可以向Bi_(12)O_(17)Cl_(2)的导带上迁移.与此同时,位于二氧化钛价带上的空穴,可以向Bi_(12)O_(17)Cl_(2)的价带上迁移,使得TiO_(2)中光生电子与空穴的复合率得以有效降低,进而提高了Bi_(12)O_(17)Cl_(2)/TiO_(2)光催化降解率.由于发生上述电荷转移,能够使电子-空穴对有效分离,即提升了光催化降解甲基橙的活性.光生电子与O_(2)发生反应,生成·O_(2)^(-).而·O_(2)^(-)与h^(+)为具有很强氧化能力的活性自由基,可以把甲基橙氧化降解为CO_(2)、H_(2)O和N_(2)等无机矿化产物.这将对于开发新型光催化材料、深度处理有机染料污染物和保护环境具有重要意义. 展开更多
关键词 光催化 TiO_(2) 三氯化铋 复合光催化剂 Bi_(12)O_(17)Cl_(2) 甲基橙
在线阅读 下载PDF
急性脑梗死患者血清NRG-1、CHIT1、Cx43、MECP2水平变化及其与病情严重程度、预后的关系
6
作者 李劲松 华森鑫 +1 位作者 黄璐丹 苏清 《实用医学杂志》 北大核心 2026年第4期691-697,共7页
目的 探讨急性脑梗死(ACI)患者血清神经调节蛋白-1(NRG-1)、几丁质酶1(CHIT1)、间隙连接蛋白43(Cx43)、甲基CpG结合蛋白2(MECP2)水平变化及其与病情严重程度、预后的关系。方法 选取2023年9月至2024年11月武汉市第一医院收治的355例ACI... 目的 探讨急性脑梗死(ACI)患者血清神经调节蛋白-1(NRG-1)、几丁质酶1(CHIT1)、间隙连接蛋白43(Cx43)、甲基CpG结合蛋白2(MECP2)水平变化及其与病情严重程度、预后的关系。方法 选取2023年9月至2024年11月武汉市第一医院收治的355例ACI患者作为病例组,根据患者病情严重程度分为重度组(49例)、中度组(126例)和轻度组(180例),患者入院后均接受超早期静脉溶栓治疗,治疗后均观察3个月,根据预后情况分为预后不良组(81例)和预后良好组(274例),另外按照1:1比例选取同期于武汉市第一医院接受健康体检的健康人群355名作为对照组。比较各组基本资料及血清NRG-1、CHIT1、Cx43、MECP2水平,采用多因素logistic回归分析ACI患者预后不良的危险因素,并绘制受试者工作特征(ROC)曲线,获取曲线下面积(AUC),分析血清NRG-1、CHIT1、Cx43、MECP2对ACI患者预后不良的预测价值。结果 较对照组,病例组血清NRG-1水平更低,而血清CHIT1、Cx43、MECP2水平更高(P<0.05)。血清NRG-1水平在轻、中、重度组之间逐渐降低,而血清CHIT1、Cx43、MECP2水平在3组之间逐渐升高(P<0.05)。预后不良组入院时美国国立卫生研究院卒中量表(NIHSS)评分≥15分、大面积梗死、发病至溶栓时间为3~4.5 h比例及血清CHIT1、Cx43、MECP2水平高于预后良好组(P<0.05),而血清NRG-1水平低于预后良好组(P<0.05)。多因素logistic回归分析结果显示,血清CHIT1、Cx43、MECP2水平均是ACI患者预后不良的危险因素(P<0.05),而血清NRG-1水平是保护因素(P<0.05)。ROC分析结果显示,血清NRG-1、CHIT1、Cx43、MECP2联合检测预测ACI患者预后不良的AUC值为0.931,高于各指标单独检测(0.796、0.801、0.791、0.805,P<0.05)。结论 ACI患者血清NRG-1水平呈低表达,而血清CHIT1、Cx43、MECP2水平呈高表达,且四者与患者病情严重程度及预后不良密切相关,同时血清NRG-1、CHIT1、Cx43、MECP2联合检测对ACI患者预后不良的预测价值更高。 展开更多
关键词 急性脑梗死 神经调节蛋白-1 几丁质酶1 间隙连接蛋白43 甲基CpG结合蛋白2 病情严重程度 预后
暂未订购
(E)-2-硝基甲基肉桂酸甲酯的合成
7
作者 任小雨 王天利 《实验室科学》 2026年第1期21-26,共6页
将科研课题融入实验教学,是培养本科生实践能力和科研素质的重要内容。有机膦催化的硝基甲苯和丙炔酸酯快速构建(E)-2-硝基甲基肉桂酸甲酯的创新实验,原料成本低,实验条件温和、反应时长适中,实验难度适中,产率优良且稳定性好,实验包含... 将科研课题融入实验教学,是培养本科生实践能力和科研素质的重要内容。有机膦催化的硝基甲苯和丙炔酸酯快速构建(E)-2-硝基甲基肉桂酸甲酯的创新实验,原料成本低,实验条件温和、反应时长适中,实验难度适中,产率优良且稳定性好,实验包含回流、萃取、薄层色谱监测反应的进程、柱层析法进行产品纯化、核磁共振波谱对结构表征等知识点。学生在巩固基本知识和技能的基础上,学习从事科学研究的基本思路,激发学生对科学探索的兴趣。 展开更多
关键词 有机膦催化 重排反应 (E)-2-硝基甲基肉桂酸甲酯 有机创新实验 科研成果转化
在线阅读 下载PDF
一种大环肽中间体—[2-(5-甲酰基-3-甲基-吡唑-1-甲基)-苄基]-氨基-9氢-芴基甲酯的合成
8
作者 殷跃凡 龚晓莹 《广东化工》 2026年第1期8-12,共5页
以5-甲基吡唑-3-甲酸甲酯和2-氰基苄溴为主要原料,经过N-烷基化取代反应、氢化铝锂还原反应、胺基保护反应以及氧化反应,得到了一种大环肽中间体—[2-(5-甲酰基-3-甲基-吡唑-1-甲基)-苄基]-氨基-9芴基甲酯,总摩尔收率为29.3%,各步所得... 以5-甲基吡唑-3-甲酸甲酯和2-氰基苄溴为主要原料,经过N-烷基化取代反应、氢化铝锂还原反应、胺基保护反应以及氧化反应,得到了一种大环肽中间体—[2-(5-甲酰基-3-甲基-吡唑-1-甲基)-苄基]-氨基-9芴基甲酯,总摩尔收率为29.3%,各步所得产物经质谱、核磁共振氢谱等进行结构确证,其中第一步的N-烷基化取代反应,经过条件优化收率得到了提升至52.3%。 展开更多
关键词 烷基化取代 还原 胺基保护 氧化 中间体 [2-(5-甲酰基-3-甲基-吡唑-1-甲基)-苄基]-氨基-9芴基甲酯 结构确证
在线阅读 下载PDF
Odorless and Practical Thioacetalization Reagent: Methyl 2-(1,3-Dithian-2-ylidene)-3-oxobutanoate
9
作者 孙然 刘群 +4 位作者 于海丰 赵玉龙 刘军 欧阳艳 董德文 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2005年第8期1060-1064,共5页
a-Oxo ketene dithioacetals, methyl 2-(1,3-dithian/dithiolan-2-ylidene)-3-oxobutanoate (2a/2b) prepared in nearly quantitative yields simply from methyl acetylacetate, carbon disulfide and 1,3-dibromopropane/1,2-di... a-Oxo ketene dithioacetals, methyl 2-(1,3-dithian/dithiolan-2-ylidene)-3-oxobutanoate (2a/2b) prepared in nearly quantitative yields simply from methyl acetylacetate, carbon disulfide and 1,3-dibromopropane/1,2-dibromoethane in the presence of potassium carbonate, were investigated in the thioacetalization with various carbonyl compounds 3. It has been demonstrated that methyl 2-(1,3-dithian-2-ylidene)-3-oxobutanoate (2a) could act as a nonthiolic, odorless and practical thioacetalization reagent. A range of aldehydes and ketones 3 were converted into the corresponding dithioacetals 4 in high yields (up to 91%) in the presence of 2a. Moreover, 2a showed high chemoselectivity between aldehyde and ketone in thioacetalization. 展开更多
关键词 methyl 2-(1 3-dithian-2-ylidene)-3-oxobutanoate thiol equivalent thioacetalization CHEMOSELECTIVITY
原文传递
Synthesis and Crystal Structure of Lanthanum Nitrate with Methyl-2-pyridyl Ketone Benzoyl Hydrazone 被引量:5
10
作者 TAIXi-shi YINXian-hong +2 位作者 LIUDe-bo TANMin-yu YUKai-bei 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2003年第4期434-436,共3页
A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 ... A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 5660(3) nm, c =1 3512(3) nm, α=90 00°, β=94 39(1)°, γ=90 00°, V =3 6037(12) nm 3, Z =4 . The complex is a ten-coordinated one with a lanthanum ion surrounded by a N 4O 6 set. The crystal structure is stabilized by hydrogen bonds between water molecules and NO - 3 anions. 展开更多
关键词 SYNTHESIS Lanthanum complex methyl-2-pyridyl ketone benzoyl hydrazone Crystal structure
在线阅读 下载PDF
新型长效植物调节剂2-O-β-L-glucopyranoside-4-O-methyl phloracetophenone的全合成
11
作者 陈靖 李晓东 +3 位作者 孙铁民 张蕾 吴秀丽 王金辉 《天然产物研究与开发》 CAS CSCD 北大核心 2013年第11期1469-1473,共5页
以β-L-(-)葡萄糖、无水醋酐及吡啶为原料,通过五步反应进行全合成,制备一种新型植物生长调节剂;β-D-葡萄糖水解酶催化下进行水解反应,研究其水解曲线。全合成产物经1H NMR鉴定为2-O-β-L-glucopyranoside-4-O-methyl phloracetophenon... 以β-L-(-)葡萄糖、无水醋酐及吡啶为原料,通过五步反应进行全合成,制备一种新型植物生长调节剂;β-D-葡萄糖水解酶催化下进行水解反应,研究其水解曲线。全合成产物经1H NMR鉴定为2-O-β-L-glucopyranoside-4-O-methyl phloracetophenone(1),总得率17.4%;水解实验表明domesticoside(2)可被β-D-葡萄糖水解酶水解为苷元,而化合物(1)不被水解。本法可作为一种新型长效生长调节剂的制备方法,也为体内快速被β-D-葡萄糖水解酶水解失活药物的结构修饰提供了新的思路。 展开更多
关键词 2-O-β-L-glueopyranoside-4-O-methylphloraeetophenone β-L-(-)葡萄糖 水解 调节剂
暂未订购
Treatment of taste and odor causing compounds 2-methyl isoborneol and geosmin in drinking water:A critical review 被引量:48
12
作者 Rangesh Srinivasan George A.Sorial 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第1期1-13,共13页
Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinkin... Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinking water and are mainly caused by the presence of two semi-volatile compounds - 2-methyl isobomeol (MIB) and geosmin. A review of these two taste and odor causing compounds in drinking water is presented. The sources for the formation of these compounds in water are discussed alongwith the health and regulatory implications. The recent developments in the analysis of MIB/geosmin in water which have allowed for rapid measurements in the nanogram per liter concentrations are also discussed. This review focuses on the relevant treatment alternatives, that are described in detail with emphasis on their respective advantages and problems associated with their implementation in a full- scale facility. Conventional treatment processes in water treatment plants, such as coagulation, sedimentation and chlorination have been found to be ineffective for removal of M1B/geosmin. Studies have shown powdered activated carbon, ozonation and biofiltration to be effective in treatment of these two compounds. Although some of these technologies are more effective and show more promise than the others, much work remains to be done to optimize these technologies so that they can be retrofitted or installed with minimal impact on the overall operation and effectiveness of the treatment system. 展开更多
关键词 adsorption drinking water GEOSMIN 2-methyl isoborneol (MIB) odor taste
原文传递
半导体废水中N-甲基-2-吡咯烷酮的潜在风险及去除特性 被引量:1
13
作者 陈晓雯 巫寅虎 +8 位作者 黄南 张倬玮 王琦 王文龙 吴乾元 熊江磊 罗嘉豪 于红 胡洪营 《工业水处理》 北大核心 2025年第4期10-16,26,共8页
N-甲基-2-吡咯烷酮(NMP)作为半导体行业废水中的典型有机物,具有浓度高、降解难等特点,已成为行业重点关注的污染物,所以探明NMP在废水中的赋存特征、潜在风险及降解特性对行业废水的高效低耗处理具有重要意义。总结了半导体废水中NMP... N-甲基-2-吡咯烷酮(NMP)作为半导体行业废水中的典型有机物,具有浓度高、降解难等特点,已成为行业重点关注的污染物,所以探明NMP在废水中的赋存特征、潜在风险及降解特性对行业废水的高效低耗处理具有重要意义。总结了半导体废水中NMP的来源、浓度和毒性风险,梳理了NMP的主要处理工艺、去除效果和降解规律,探讨了现有处理工艺存在的主要问题及解决建议。NMP主要来源于半导体制造过程的清洗剂,在半导体废水中具有较高的浓度和较强的生物毒性。现有技术对NMP的处理包括物理分离、生物处理和化学降解等,但存在去除不彻底、产生高毒性中间产物等问题。建议从NMP脱毒工艺开发及强化去除机理等方面开展研究,并着眼于行业链条,结合源头工艺革新和资源化回收,实现对NMP风险的全过程控制。 展开更多
关键词 半导体行业废水 N-甲基-2-吡咯烷酮 风险控制
在线阅读 下载PDF
FAM19A4/miR124-2基因甲基化与p16/Ki-67联合检测对宫颈癌前病变的诊断效能
14
作者 黄鹏翀 李鹏程 沈乾坤 《实用癌症杂志》 2025年第8期1353-1356,共4页
目的探究FAM19A4/miR124-2基因甲基化联合p16/Ki-67检测能否提高宫颈癌筛查的检测效能。方法收集宫颈非典型鳞状细胞患者96例为研究对象,病理学检查判断宫颈病变分型,液基薄层细胞学(TCT)观察患者的FAM19A4/miR124-2基因甲基化,免疫组化... 目的探究FAM19A4/miR124-2基因甲基化联合p16/Ki-67检测能否提高宫颈癌筛查的检测效能。方法收集宫颈非典型鳞状细胞患者96例为研究对象,病理学检查判断宫颈病变分型,液基薄层细胞学(TCT)观察患者的FAM19A4/miR124-2基因甲基化,免疫组化(IHC)检测p16和Ki-67的阳性率。结果宫颈脱落细胞中FAM19A4/miR124-2甲基化阳性率为68.75%,且随着宫颈病变严重程度增加;根据p16/Ki-67的IHC进行IS评分分组,对宫颈上皮瘤变的严重程度有一定的区分度。FAM19A4/miR124-2甲基化联合p16/Ki-67检测敏感性和特异性分别为90%和85%,AUC为0.92。结论FAM19A4/miR124-2甲基化和p16/Ki-67免疫组化检测对宫颈≥HSIL病变均具有较高临床价值,联合p16/Ki-67检测能更灵敏准确地检测出宫颈≥HSIL的病变。 展开更多
关键词 宫颈癌前病变 FAM19A4/miR124-2 甲基化 p16/Ki-67
暂未订购
Liver insulin-like growth factor 2 methylation in hepatitis C virus cirrhosis and further occurrence of hepatocellular carcinoma 被引量:6
15
作者 Philippe Couvert Alain Carrié +8 位作者 Jacques Pariès Jenny Vaysse Audrey Miroglio Antoine Kerjean Pierre Nahon Jamel Chelly Jean-Claude Trinchet Michel Beaugrand Nathalie Ganne-Carrié 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第35期5419-5427,共9页
AIM: To assess the predictive value of the insulinlike growth factor 2 (Igf2) methylation profile for the occurrence of Hepatocellular Carcinoma (HCC) in hepatitis C (HCV) cirrhosis. METHODS: Patients with: (1) biopsy... AIM: To assess the predictive value of the insulinlike growth factor 2 (Igf2) methylation profile for the occurrence of Hepatocellular Carcinoma (HCC) in hepatitis C (HCV) cirrhosis. METHODS: Patients with: (1) biopsy-proven compensated HCV cirrhosis; (2) available baseline frozen liver sample; (3) absence of detectable HCC; (4) regular screening for HCC; (5) informed consent for genetic analysis were studied. After DNA extraction from liver samples and bisulfite treatment, unbiased PCR and DHPLC analysis were performed for methylation analysis at the Igf2 locus. The predictive value of the Igf2 methylation profile for HCC wasassessed by Kaplan-Meier and Cox methods. RESULTS: Among 94 included patients, 20 developed an HCC during follow-up (6.9 ± 3.2 years). The methylation profile was hypomethylated, intermediate and hypermethylated in 13, 64 and 17 cases, respectively. In univariate analysis, two baseline parameters were associated with the occurrence of HCC: age (P = 0.01) and prothrombin (P = 0.04). The test of linear tendency between the three ordered levels of Igf2 methylation and probability of HCC occurrence was significant (Log Rank, P = 0.043; Breslow, P = 0.037; Tarone-Ware, P = 0.039). CONCLUSION: These results suggest that hypomethylation at the Igf2 locus in the liver could be predictive for HCC occurrence in HCV cirrhosis. 展开更多
关键词 Liver cancer CIRRHOSIS Insulin-growth factor 2 DNA methylation
暂未订购
Synthesis and Crystal Structure of a Co(Ⅱ) Complex with Taurine-5-methyl-2-hydroxyisophthalaldehyde Schiff Bases [Co(C_(13)H_(16)N_2O_7S_2)(H_2O)_3]_2·H_2O 被引量:2
16
作者 QIN Xiu-Ying JIANG Yi-Min +1 位作者 ZHANG Shu-Hua MO Qian-Qun 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第2期205-209,共5页
The title complex [CoL(H20)3]2·H2O (C26H46N4O21S4CO2), where L = taurine-5- methyl-2-hydroxyisophthalaldehydes, has been synthesized and characterized by IR and X-ray diffraction analysis. The crystal of the ... The title complex [CoL(H20)3]2·H2O (C26H46N4O21S4CO2), where L = taurine-5- methyl-2-hydroxyisophthalaldehydes, has been synthesized and characterized by IR and X-ray diffraction analysis. The crystal of the complex belongs to the triclinic system, space group P1, with a = 11.197(4), b = 13.309(5), c = 14.486(5) ]A, a = 78.827(13),β = 70.547(11), γ = 81.058(13)°, Mr = 996.77, S = 1.08, V= 1987.2(13) A3, Z = 2, Dc = 1.666 g/cm3, F(000) = 1032,μ = 1.131 mm^-1, R = 0.0633 and wR = 0.1293. According to the structural analysis, the Co( Ⅱ ) ion adopts a slightly distorted six-coordinated octahedral geometry. One N atom of the Schiff base of each molecule was hydrogenated to form hydrogen bond with O atom. Two coterminous molecules packed in one crystal water molecule are linked by intermolecular hydrogen bonds, thus generating an infinite chain constructed by hydrogen bonds. 展开更多
关键词 cobalt(Ⅱ) complex taurine-5-methyl-2-hydroxyisophthalaldehydes crystal structure
在线阅读 下载PDF
Regeneration of 2-amino-2-methyl-1-propanol used for carbon dioxide absorption 被引量:21
17
作者 ZHANG Pei SHI Yao WEI Jianwen ZHAO Wei YE Qing 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第1期39-44,共6页
To improve the efficiency of the carbon dioxide cycling process and to reduce the regeneration energy consumption, a sterically hindered amine of 2-amino-2-methyl-1- propranol (AMP) was investigated to determine its... To improve the efficiency of the carbon dioxide cycling process and to reduce the regeneration energy consumption, a sterically hindered amine of 2-amino-2-methyl-1- propranol (AMP) was investigated to determine its regeneration behavior as a CO2 absorbent. The CO2 absorption and amine regeneration characteristics were experimentally examined under various operating conditions. The regeneration efficiency increased from 86.2% to 98.3% during the temperature range of 358 to 403 K. The most suitable regeneration temperature for AMP was 383 K, in this experiment condition, and the regeneration efficiency of absorption/regeneration runs descended from 98.3% to 94.0%. A number of heat-stable salts (HSS) could cause a reduction in CO2 absorption capacity and regeneration efficiency. The results indicated that aqueous AMP was easier to regenerate with less loss of absorption capacity than other amines, such as, monoethanolamine (MEA), diethanolamine (DEA), diethylenetriamine (DETA), and N-methyldiethanolamine (MDEA). 展开更多
关键词 carbon dioxide 2-amino-2-methyl-1-propanol regeneration efficiency energy consumption
在线阅读 下载PDF
Amino-functionalized magnetic bacterial cellulose/activated carbon composite for Pb^2+ and methyl orange sorption from aqueous solution 被引量:7
18
作者 Xiaogui Huang Xiaozhang Zhan +2 位作者 Cuilian Wen Feng Xu Lijin Luo 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2018年第5期855-863,共9页
A new nanostructured amino-functionalized magnetic bacterial cellulose/activated carbon(BC/AC)composite bioadsorbent(AMBCAC)was prepared for removal of Pb^2+ and methyl orange(MO)from aqueous solution.The resul... A new nanostructured amino-functionalized magnetic bacterial cellulose/activated carbon(BC/AC)composite bioadsorbent(AMBCAC)was prepared for removal of Pb^2+ and methyl orange(MO)from aqueous solution.The results demonstrated that the equilibrium adsorption capacity(qe)for Pb^2+ obviously increases by 2.14 times after introduction of amino groups,the optimum p H for Pb^2+and MO adsorption was 5.0 and 3.0,respectively,and the qeof AMBCAC was 161.78 mg g^-1 for Pb^2+ and 83.26 mg g^-1 for MO under the optimal conditions in this investigation.The kinetics and adsorption isotherm data of the sorption process were well fitted by pseudo-second-order kinetic model and Langmuir isotherm respectively.The thermodynamic results(the Gibbs free energy change G〈0,the enthalpy change H〉0,the entropy change S〉0)implied that the adsorption process of Pb^2+ and MO was feasible,endothermic and spontaneous in nature.These results support that the AMBCAC composite developed in this work can provide a cheap and efficient way for easy removal of both Pb^2+ and MO as a promising adsorbent candidate for wastewater treatment. 展开更多
关键词 Bacterial cellulose Activated carbon Pb^2 methyl orange Adsorption
原文传递
Synthesis of fused pyran and arylbis(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methane in ionic liquid 被引量:2
19
作者 Xue Sen Fan Ying Ying Qu Xin Ying Zhang Xia Wang Jian Ji Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第4期387-390,共4页
Promoted and mediated by an ionic liquid-[bmim][BF4], fused pyrans or arylbis(4-hydroxy-6-methyl-2-oxo-2H-pyran-3- yl)methanes were efficiently and selectively prepared from the reaction of aldehyde and 4-hydroxy-6-... Promoted and mediated by an ionic liquid-[bmim][BF4], fused pyrans or arylbis(4-hydroxy-6-methyl-2-oxo-2H-pyran-3- yl)methanes were efficiently and selectively prepared from the reaction of aldehyde and 4-hydroxy-6-methyl-2-oxo-pyran with or without acetic anhydride. By using these novel procedures, pyrimidine nucleoside-fused pyran and arylbis(pyranon-3-yl)methane hybrids with potential biological activities were constructed. 展开更多
关键词 Ionic liquid Fused pyran Arylbis(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methane Pyrimidine nucleoside Green synthesis
在线阅读 下载PDF
橘小实蝇雌雄成虫对甲基丁香酚及其类似物2-烯丙基-4,5-二甲氧基苯酚的行为和电生理反应 被引量:1
20
作者 张盼盼 张杰 +3 位作者 张艳 严善春 刘伟 王桂荣 《昆虫学报》 北大核心 2025年第6期785-796,共12页
【目的】针对全球重要果蔬害虫橘小实蝇Bactrocera dorsalis,基于雄性引诱剂的雄性歼灭技术(male annihilation technique,MAT)已被广泛应用,其中甲基丁香酚(methyl eugenol,ME)作为核心引诱剂,对雄虫表现出高效的引诱作用。然而,现有... 【目的】针对全球重要果蔬害虫橘小实蝇Bactrocera dorsalis,基于雄性引诱剂的雄性歼灭技术(male annihilation technique,MAT)已被广泛应用,其中甲基丁香酚(methyl eugenol,ME)作为核心引诱剂,对雄虫表现出高效的引诱作用。然而,现有技术主要针对雄虫,雌虫对ME的行为反应及其嗅觉感知能力尚不明确,成为限制以ME为基础的雌性引诱剂全面优化的瓶颈。因此,本研究旨在系统揭示橘小实蝇雌成虫对ME的行为反应及嗅觉感知能力,探索ME在橘小实蝇雌虫中的潜在生物学作用,为优化应用ME的雌虫防控策略提供新的研究思路。【方法】为明确橘小实蝇雌成虫对ME的行为反应和感知能力,选择生理状态活跃的12日龄雌雄成虫作为试虫,首先利用嗅觉陷阱实验与四臂嗅觉仪实验测试了橘小实蝇雌雄成虫对剂量为1000和100μg的ME以及具有类似诱雄功能的2-烯丙基-4,5-二甲氧基苯酚(2-allyl-4,5-dimethoxy phenol,DMP)的趋向行为,对剂量为1000μg ME和DMP的取食行为;其次利用触角电位(electroantennogram,EAG)反应实验测定剂量为0.1,1,10和100μg的ME和DMP引起的橘小实蝇雌雄成虫的EAG反应;最后利用单感器技术(single sensillum recording,SSR)记录了橘小实蝇雌雄成虫触角上锥形感器对ME和DMP的SSR反应。【结果】行为学测试结果表明,橘小实蝇雌成虫未对ME和DMP表现出明显的趋向行为或取食倾向,而雄成虫表现强烈的行为反应。然而,EAG实验则显示,橘小实蝇雌成虫与雄成虫类似,对ME和DMP均产生了显著的嗅觉响应;进一步的SSR实验发现,橘小实蝇雌成虫具有与雄成虫类似的嗅觉感器,负责ME和DMP的感知。【结论】本研究结果提示,橘小实蝇雌成虫具备与雄成虫类似的ME嗅觉感知机制,但ME对雌成虫的行为的影响不同于对雄成虫的诱集功能,ME对雌成虫可能具有其他潜在的生物学作用。这些结果为深入理解橘小实蝇对ME的感知与行为反应提供了新的实验依据,同时为改良雌虫行为调控技术提供了理论参考。 展开更多
关键词 橘小实蝇 性二态行为 甲基丁香酚 2-烯丙基-4 5-二甲氧基苯酚 行为反应 电生理反应
在线阅读 下载PDF
上一页 1 2 179 下一页 到第
使用帮助 返回顶部