期刊文献+
共找到225篇文章
< 1 2 12 >
每页显示 20 50 100
SSZ-13分子筛在二甲醚羰基化反应中的机理研究和空间限域效应
1
作者 张晓敏 蔡凯 +6 位作者 李媖 戚暨 王悦 刘云铎 王美岩 黄守莹 马新宾 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第6期301-311,共11页
乙醇作为一种绿色清洁的燃料替代品和油品添加剂,在全球有广泛的市场需求.利用合成气经乙酸甲酯(MA)合成乙醇的工艺路线,因其原子经济性、产品选择性高、反应条件温和等优势而备受关注.其中,二甲醚(DME)羰基化是该路线的关键步骤之一.... 乙醇作为一种绿色清洁的燃料替代品和油品添加剂,在全球有广泛的市场需求.利用合成气经乙酸甲酯(MA)合成乙醇的工艺路线,因其原子经济性、产品选择性高、反应条件温和等优势而备受关注.其中,二甲醚(DME)羰基化是该路线的关键步骤之一.研究证实,具有8元环(8-MR)孔道结构的硅铝酸盐微孔分子筛可以在较低的反应温度下高选择性催化二甲醚羰基化反应.目前,研究者已经对丝光沸石(MOR)、镁碱沸石(FER)等分子筛进行了全面深入的分析,但对SSZ-13等菱沸石(CHA型)的研究有限,缺乏SSZ-13上主、副反应催化机理的阐释,并且忽略了沸石独特的笼状结构在反应中的空间限域效应.本文结合实验和理论计算确定了SSZ-13分子筛催化DME羰基化的活性位点,并探究了孔道的限域效应.通过负载具有不同尺寸的Na^(+)和Cs^(+)实现了对不同通道中Brönsted酸位点(BAS)的选择性屏蔽.酸性质表征和密度泛函理论(DFT)计算结果表明,在较低的负载量下,Na^(+)优先取代SSZ-13的6元环(6-MR)中的BAS,而Cs^(+)由于其较大的离子半径只能与8-MR中的BAS发生交换,从而实现了对SSZ-13不同孔道中酸分布的调控.负载不同金属量以及金属种类的样品活性研究表明,当6-MR中BAS减少时,DME转化率基本不变;而当8-MR中BAS被离子交换时,DME转化率明显下降.随后,将未经金属改性的、具有不同硅铝比的母体SSZ-13样品的MA生成速率与其8-MR中BAS的数量相关联,发现两者呈较好的线性关系,说明SSZ-13的8-MR中BAS为DME羰基化的活性中心.同时,DFT计算了DME在不同孔道BAS上的解离能,结果表明DME更容易在8-MR的BAS上解离从而进行后续反应.随后,探究了SSZ-13笼的空间限域效应对主副反应的影响机制.通过比较金属负载量相近的Na/H-SSZ-13和Cs/H-SSZ-13上CO插入甲氧基形成烯酮的反应势垒,证实了较大尺寸金属离子的引入增加了主反应速控步的能垒.为了揭示空间限域对副反应的影响,比较了反应后催化剂的热重、气质联用等表征结果,并利用密度泛函理论计算了副反应的关键物种(七甲基苯正离子)在Na/H-SSZ-13和Cs/H-SSZ-13上的吸附能,证实了SSZ-13的笼状结构体积是影响MA选择性的关键因素.金属负载后SSZ-13笼空间减少,可以有效地抑制副反应关键物种的形成,从而提高主反应选择性.综上,本文不仅对SSZ-13分子筛催化二甲醚羰基化反应机理进行了全面解析,并通过实验设计,改变了SSZ-13分子筛的孔道结构和笼结构空间,突出了分子筛限域效应在二甲醚羰基化反应中的重要作用.本文研究结果为设计具有较高选择性的沸石催化剂提供一定的参考. 展开更多
关键词 二甲醚 羰基化 SSZ-13分子筛 酸位点 限域效应
下载PDF
血清Apelin-13、脂肪酸结合蛋白4水平与绝经后骨质疏松症的相关性研究
2
作者 徐曼灵 朱静波 +5 位作者 俞恺雯 陈玲 樊华英 范庆涛 王秋萍 鲁燕 《实用临床医药杂志》 CAS 2024年第11期73-78,83,共7页
目的探讨血清Apelin-13、脂肪酸结合蛋白4(FABP4)水平与不同骨量绝经后女性代谢参数和骨代谢指标的相关性。方法选取145例绝经后女性作为研究对象,根据骨密度(BMD)检测结果分为骨量正常组49例、骨量减少(ON)组51例和骨质疏松(OP)组45例... 目的探讨血清Apelin-13、脂肪酸结合蛋白4(FABP4)水平与不同骨量绝经后女性代谢参数和骨代谢指标的相关性。方法选取145例绝经后女性作为研究对象,根据骨密度(BMD)检测结果分为骨量正常组49例、骨量减少(ON)组51例和骨质疏松(OP)组45例,测定并比较3组血清Apelin-13、FABP4水平和骨代谢指标、生化指标水平。采用Spearman相关分析法分析Apelin-13、FABP4等指标与BMD的相关性,采用多因素Logistic回归分析法分析OP的危险因素,绘制受试者工作特征(ROC)曲线分析血清Apelin-13对绝经后骨质疏松症(PMOP)的预测价值。结果OP组血清Apelin-13水平低于ON组、骨量正常组,差异有统计学意义(P<0.05);3组血清FABP4水平比较,差异无统计学意义(P>0.05);OP组血清甲状旁腺激素(PTH)、碱性磷酸酶(ALP)、Ⅰ型前胶原氨基端前肽(PⅠNP)、Ⅰ型胶原交联C端肽(CTXⅠ)、骨特异性碱性磷酸酶(BALP)水平高于ON组、骨量正常组,差异有统计学意义(P<0.05)。绝经后女性腰椎BMD与血清Apelin-13水平呈正相关(P<0.05),与血清FABP4水平无相关性(P>0.05);腰椎BMD与血清PTH、ALP、PⅠNP、CTXⅠ、BALP和年龄呈负相关(P<0.05),与体质量、体质量指数、T值、空腹胰岛素、胰岛素抵抗指数呈正相关(P<0.05)。多因素Logistic回归分析显示,血清Apelin-13、PTH、ALP、PⅠNP、CTXⅠ、BALP水平均为绝经后女性发生OP的独立影响因素(P<0.05)。ROC曲线结果显示,血清Apelin-13预测PMOP的最佳临界值为18.51 pg/mL,曲线下面积为0.716,敏感度为70.0%,特异度为64.4%。结论Apelin-13在PMOP患者血清中呈低表达,且其表达水平与腰椎BMD密切相关,或可作为PMOP的早期筛查指标和潜在治疗靶点。 展开更多
关键词 绝经后骨质疏松症 APELIN-13 脂肪酸结合蛋白4 Ⅰ型前胶原氨基端前肽 Ⅰ型胶原交联C端肽 骨特异性碱性磷酸酶
下载PDF
载Apelin-13缓释微囊的新型生物支架促兔输卵管再通的初步研究
3
作者 赵群 薛敏 +3 位作者 李俞延 郑义凡 徐哲伟 李志跃 《中南大学学报(医学版)》 CAS CSCD 北大核心 2023年第9期1304-1315,共12页
目的:输卵管炎性不孕症严重危害女性自然生育功能,临床迫切需求的真正意义上的输卵管再通包括病变输卵管解剖和功能的修复两方面,目前尚无有效的治疗方案。本研究旨在从这两方面探讨促进输卵管修复再通的方法。方法:制备Apelin-13缓释... 目的:输卵管炎性不孕症严重危害女性自然生育功能,临床迫切需求的真正意义上的输卵管再通包括病变输卵管解剖和功能的修复两方面,目前尚无有效的治疗方案。本研究旨在从这两方面探讨促进输卵管修复再通的方法。方法:制备Apelin-13缓释微囊和聚乳酸-羟基乙酸共聚物[poly(lactic-co-glycolic acid),PLGA]三维生物支架,检测生物支架的基本特性及体内降解情况(质量损失率),微囊的体外释药(累积释药率)、体内释药(Apelin-13血药浓度)及体外降解(降解率)情况。将Apelin-13微囊(微囊组)/载Apelin-13缓释微囊的PLGA三维生物支架(支架微囊组)注入/置入慢性输卵管炎新西兰兔模型的输卵管,观察和比较对照组、模型组、微囊组和支架微囊组术后输卵管的通畅情况、镜下结构、雌激素受体和孕激素受体的阳性表达情况。结果:术后第4周时PLGA三维生物支架的质量损失率为98.66%,微囊的体外降解率为70.58%,Apelin-13缓释微囊30 d体外累计释药率达98.68%,Apelin-13血药浓度在5 d内达到峰值,并在25 d内保持稳定。与模型组和微囊组相比,支架微囊组术后输卵管管腔内炎症反应轻,输卵管通畅率高,雌激素受体和孕激素受体的表达水平高(均P<0.05),支架微囊组的各项指标接近对照组。结论:载Apelin-13缓释微囊的PLGA三维生物支架可全面修复输卵管的解剖结构和生理功能,有望真正有效实现炎性输卵管再通。 展开更多
关键词 输卵管再通 聚乳酸-羟基乙酸共聚物 APELIN-13 三维生物支架 缓释微囊
下载PDF
13-Methyltetradecanoic acid mitigates cerebral ischemia/reperfusion injury 被引量:8
4
作者 Juan Yu Li-nan Yang +4 位作者 Yan-yun Wu Bao-hua Li Sheng-mei Weng Chun-lan Hu Yong-ling Han 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第9期1431-1437,共7页
13-Methyltetradecanoic acid can stabilize cell membrane and have anti-inflammatory, antioxidant and anti-apoptotic effects. Previous studies mainly focused on peripheral nerve injury, but seldom on the central nervous... 13-Methyltetradecanoic acid can stabilize cell membrane and have anti-inflammatory, antioxidant and anti-apoptotic effects. Previous studies mainly focused on peripheral nerve injury, but seldom on the central nervous system. We investigated whether these properties of 13-methyltetradecanoic acid have a neuroprotective effect on focal cerebral ischemia/reperfusion injury, and detected the expression of basic fibroblast growth factor and vascular endothelial growth factor. This study established rat models of middle cerebral artery occlusion/ reperfusion injury by ischemia for 2 hours and reperfusion for 24 hours. At the beginning of reperfusion, 13-methyltetradecanoic acid 10, 40 or 80 mg/kg was injected into the tail vein. Results found that various doses of 13-methyltetradecanoic acid effectively reduced infarct volume, mitigate cerebral edema, and increased the mRNA and protein expression of basic fibroblast growth factor and vascular endothe- lial growth factor at 24 hours of reperfusion. The effect was most significant in the 13-methyltetradecanoic acid 40 and 80 mg/kg groups. The findings suggest that 13-methyltetradecanoic acid can relieve focal ischemia/reperfusion injury immediately after reperfusion, stimu- late the upregulation of basic fibroblast growth factor and vascular endothelial growth factor to exert neuroprotective effects. 展开更多
关键词 nerve regeneration brain injury 13-methyltetradecanoic acid cerebral ischemia/reperfusion injury basic fibroblast growth factor vascular endothelial growth factor cerebral infarction cerebral edema neural regeneration
下载PDF
Simultaneous determination of 12,13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture by high performance liquid chromatography 被引量:4
5
作者 Zhi-Sheng Xie Xin-Jun Xu +4 位作者 Chun-Yan Xie Jie-Yun Huang Mei Yang Rui-Ming Li Xiao Chen 《Journal of Pharmaceutical Analysis》 SCIE CAS 2011年第3期219-222,共4页
A reversed phase high performance liquid chromatography (HPLC) method was established for the simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture. A Grace Apollo Cl8 col... A reversed phase high performance liquid chromatography (HPLC) method was established for the simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture. A Grace Apollo Cl8 column (250 mm × 4.6 mm, 5 μm) was used as the stationary phase and the mobile phase was composed of acetonitrile and aqueous phosphoric acid (0.2%, v/v). Gradient elution was carried out at the flow rate of 1.0 mL/min and the column temperature was 30 ℃. An ultraviolet (UV) detector was used with a selected wavelength of 240 nm. Calibration curves were linear within the concentration range of 4.6-45.75 μg/mL for 12, 13-dihydroxyeuparin (r〉0.9999) and 106.9-1068.9μg/mL for glycyrrhizic acid (r〉0.9999), respectively. Recoveries were 102.18% for 12, 13-dihydroxyeuparin and 101.17% for glycyrrhizic acid. The method developed could be applied to the simultaneous determination of 12, 13- dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture. 展开更多
关键词 12 13-Dihydroxy-euparin Glycyrrhizic acid Yanyanfang mixture High performance liquidchromatography
下载PDF
Short- and medium-term reproducibility of gastric emptying of a solid meal determined by a low dose of ^(13)C-octanoic acid and nondispersive isotope-selective infrared spectrometry 被引量:2
6
作者 Anna Kasicka-Jonderko Magdalena Kami■ska +2 位作者 Krzysztof Jonderko Olga Setera Barbara Blo■ska-Fajfrowska 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第8期1243-1248,共6页
AIM: To evaluate the reproducibility of a modified 13^C breath test-based measurement of solid phase gastric emptying (GE) within the frames of a simple-repeated measure study protocol. METHODS: Twelve healthy sub... AIM: To evaluate the reproducibility of a modified 13^C breath test-based measurement of solid phase gastric emptying (GE) within the frames of a simple-repeated measure study protocol. METHODS: Twelve healthy subjects (6 females and 6 males, mean age 24.9+0.7 years) were recruited to undergo three identical GE examinations. In six subjects the first two examinations were performed 2 d apart, and the third session was carried out at a median interval of 19.5 d (range 18 - 20 d) from the second one. In another six subjects the first two measurements were taken 20 d apart (median, range: 17-23 d), whereas the third session took place 2 d after the second one. Probes of expiratory air collected before and during six hours after intake of a solid meal (378 kcal) labelled with 75 μL (68 mg) 13^C-octanoic acid, were measured for 13^CO2 enrichment with the nondispersive isotopeselective infrared spectrometry NDIRS apparatus. RESULTS: Taking coefficients of variation for paired examinations into account, the short-term reproducibility of the GE measurement was slightly but not significantly better than the medium-term one: 7.7% and 11.2% for the lag phase (T-Lag), 7.3% and 10.9% for the gastric half emptying time (T1/2). The least differences in GE parameters detectable at P= 0.05 level in the 12 paired examinations were 9.6 and 15.6 min for T-Lag, 11.6 and 19.7 min for T1/2 by a two-day or two to three-week time gap, respectively CONCLUSION: The low-cost modification of the breath test involving a lower dose of 13^C-octanoic acid and NDIRS, renders good short- and medium-term reproducibility, as well as sensitivity of the measurement of gastric emptying of solids. 展开更多
关键词 13^C breath test Gastric emptying Nondispersive isotope-selective infrared spectrometry 13^C-octanoic acid REPRODUCIBILITY
下载PDF
Delayed Gastric Emptying in Anorexic Adolescents Measured with the <sup>13</sup>C Octanoic Acid Breath Test 被引量:1
7
作者 Martine K. F. Docx Kristin Verbeke +4 位作者 Annik Simons Joost Weyler José Ramet Luc Mertens Gigi Veereman-Wauters 《Food and Nutrition Sciences》 2012年第8期1043-1047,共5页
Many gastrointestinal complaints and motility disorders are described in patients suffering from different eating disorders. These have a negative impact on refeeding. This report evaluated–on admission-gastric empty... Many gastrointestinal complaints and motility disorders are described in patients suffering from different eating disorders. These have a negative impact on refeeding. This report evaluated–on admission-gastric emptying of a standardized solid meal with 13C octanoic acid breath test in anorexic adolescents. The results were compared with age and gender matched controls. Gastric emptying data were related to a subjective symptom score. 21 Anorexic girls and 3 boys (mean age: 15.6 y ± 1.3 y), body mass index (mean 15.6 kg/m2 ± 1.6 kg/m2), weight loss (mean: 22.2% ± 10.7%) were studied. T? of the gastric emptying time exceeded the P95 in 14/24 (58%) patients, classified as having delayed gastric emptying (DGE). One patient (4%) had a T? exceeding P75 and was classified as slow (SGE), whereas 9/24 (38%) patients had normal gastric emptying (NGE). In comparison to NGE, subjects with DGE had significantly higher symptom scores (p = 0.01) and more weight loss. The DGE and SGE patients lost 25.29% and 21.38% of weight respectively, whereas a weight loss of 17.64% was found in anorexics with NGE. In conclusion, gastric emptying is delayed in patients with anorexia. This is associated with more significant gastrointestinal symptoms and higher weight loss. 展开更多
关键词 ANOREXIA Nervosa Half-Gastric EMPTYING Time 13C Octanoic acid BREATH Test SUBJECTIVE Severity SYMPTOM Score
下载PDF
Two potentially specific but relevant patterns of proteomic change Response of SH-SY5Y cells to differentiation with retinoic acid followed by phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate, and susceptibility of differentiated cells to dopamine
8
作者 Mingxiu Tian Xing'an Li +4 位作者 Ming Chang Yingjiu Zhang Danping Wang Hongrong Xie Linsen Hu 《Neural Regeneration Research》 SCIE CAS CSCD 2010年第20期1525-1533,共9页
Dopamine (DA) exposure at a dose of 100 pmol/L for 24 hours causes oxidative stress in SH-SY5Y cells with induction of neuronal differentiation by retinoic acid (RA,10 pmol/L,72 hours) followed by phorbol ester 12... Dopamine (DA) exposure at a dose of 100 pmol/L for 24 hours causes oxidative stress in SH-SY5Y cells with induction of neuronal differentiation by retinoic acid (RA,10 pmol/L,72 hours) followed by phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA,80 nmol/L,72 hours). However,it remains unclear whether the alteration of phenotype observed in response to oxidative stress is associated with protein regulation in this cellular model for Parkinson's disease. The present study detected protein regulation affected by oxidative stress at a proteomic level:selection of differentially altered proteins using two dimensional difference in-gel electrophoresis and identification of these proteins using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. The results demonstrated significant alterations in expression of six proteins in SH-SY5Y cells following the differentiation and fourteen proteins in the differentiated cells following the exposure,exemplified by an increase of tubulin alpha1 in the former but a decrease of tubulin alpha-ubiquitous chain in the latter. These results suggest that two potentially specific but relevant patterns of proteomic change may be produced in SH-SY5Y cells with the induction of differentiation by RA followed by TPA,and in the differentiated cells after DA exposure. 展开更多
关键词 SH-SY5Y cells retinoic acid phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate DOPAMINE proteomic analysis Parkinson's disease neural regeneration
下载PDF
Acceleration of carbon-13 spin-lattice relaxation times in amino acids by electrolytes
9
作者 Tian Jinping Yin Yingwu 《合成化学》 CAS CSCD 2004年第z1期161-161,共1页
关键词 Amino acids Carboxylic acids electrolytes 13C NMR spectroscopy 13C NMR relaxationagent
下载PDF
Acid-base behavior of cryptand 1, 4, 7, 10, 13, 16, 21, 24-octaaza-bicyclo [8, 8, 8] hexacosan-3, 8, 12, 17, 20, 25-hexone and complex formation
10
作者 MO Zunli, CHEN Hong and GAO Jinzhang Institute of Chemistry, Northwest Normal University, Lanzhou 730070, China 《Rare Metals》 SCIE EI CAS CSCD 2002年第1期12-19,共8页
The bicyclic cryptand 1,4,7, 10,13,16,21, 24-octaaza-bigcyclo [8, 8,8] hexacosan-3, 8, 12, 17, 20, 25-hex-one (COBH) bearing diaminoethane groups along the eight-atom bridges was synthesized. The structure consists of... The bicyclic cryptand 1,4,7, 10,13,16,21, 24-octaaza-bigcyclo [8, 8,8] hexacosan-3, 8, 12, 17, 20, 25-hex-one (COBH) bearing diaminoethane groups along the eight-atom bridges was synthesized. The structure consists of discrete neutral macrobicyclic units; the two cycles share the two tertiary amine nitrogen atoms, which exhibit an endo-cndo conformation. Three identical branches formed by 1, 2-diaminoethane link the two tertiary amine groups. The protonation reactions of cryptand (COBH) and its complex formation with copper (II) were investigated by potentiometry in water and in a DMSO/water (80:20 in mass ratio) mixture as solvents. The cryptand acts as a his-base through its two N-bridgehead and exhibits a strong cooperativity that favors the first protonation and makes the second one difficult (△pK= 5.0). An inward rotation of the amide groups to form hydrogen bonds accounts for this cooperativity. The interaction of COBH with copper (II) leads to several binuclear complex proton contents. 展开更多
关键词 COBH(cryptand 1 4 7 10 13 16 21 24-octaaza-bigcyclo [8 8 8] hexacosan -3 8 12 17 20 25 - hex-one) macrobicyclic acid-base behavior complex formation proton contents
下载PDF
气相色谱法测定稳定同位素^13(C)标记辛酸纯度的不确定度评定
11
作者 赵诚 孙雯 袁璋晶 《肥料与健康》 CAS 2023年第1期65-69,共5页
根据行业标准《稳定同位素^13(C)标记的辛酸》(HG/T 5941—2021),采用气相色谱法测定稳定同位素^13(C)标记的辛酸纯度,对测定过程中的不确定度来源进行了分析,主要为标准溶液配制、标准曲线拟合、样品制备和样品测量重复性等。按《测定... 根据行业标准《稳定同位素^13(C)标记的辛酸》(HG/T 5941—2021),采用气相色谱法测定稳定同位素^13(C)标记的辛酸纯度,对测定过程中的不确定度来源进行了分析,主要为标准溶液配制、标准曲线拟合、样品制备和样品测量重复性等。按《测定不确定度评定与表示》(JJF 1059.1—2012)的规定进行不确定度计算,稳定同位素^13(C)标记的辛酸纯度的测量不确定度来源主要为标准溶液配制与标准曲线拟合,其合成标准不确定度为0.817%,扩展不确定度为1.6%,测定结果为99.0%±1.6%(k=2)。 展开更多
关键词 稳定同位素 ^13(C)标记辛酸 气相色谱法 不确定度
下载PDF
Biosynthesis of ^(13)C-Labeled Amino Acids and Sugars by Spirulina (Arthrospira) Maxima in a Parallelepiped Photobioreactor
12
作者 夏金兰 聂珍媛 J.M.Levert 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第5期102-106,共5页
This paper presents the investigation on biosynthesis of high-value-added amino acids and sugars labeled uniformly with stable isotope 13C by microalga Spirulina (Arthrospira) maxima in a parallelepiped photobioreacto... This paper presents the investigation on biosynthesis of high-value-added amino acids and sugars labeled uniformly with stable isotope 13C by microalga Spirulina (Arthrospira) maxima in a parallelepiped photobioreactor. The kinetic data of both batch and continuous cultures with characterization of the amino acids and sugars are shown. The continuous culture without nutrients deficiency is for biosynthesis of amino acids, with tyrosine as one of the principal constituents, and the batch culture with deficiency in nitrogen is for biosynthesis of labeled glucose that is up to 64% versus dry mass of cells. 展开更多
关键词 amino acid MICROALGA parallelepiped PHOTOBIOREACTOR SPIRULINA (Arthrospira) MAXIMA 13C-labeled sugar
全文增补中
LncRNA LUCAT1靶向调控miR-937-5p/MMP13轴对非小细胞肺癌细胞增殖、迁移能力的影响
13
作者 付堂清 李文忠 +2 位作者 罗仕云 师路 杜镇鸿 《河北医药》 CAS 2023年第6期814-819,共6页
目的 探究长链非编码核糖核酸(LncRNA)肺癌相关转录物1(LUCAT1)靶向调控微小RNA-937-5p(miR-937-5p)/基质金属蛋白酶13(MMP-13)轴对非小细胞肺癌(NSCLC)细胞增殖、迁移的影响。方法 采用定量实时聚合酶链反应(qRT-PCR)检测NSCLC组织和... 目的 探究长链非编码核糖核酸(LncRNA)肺癌相关转录物1(LUCAT1)靶向调控微小RNA-937-5p(miR-937-5p)/基质金属蛋白酶13(MMP-13)轴对非小细胞肺癌(NSCLC)细胞增殖、迁移的影响。方法 采用定量实时聚合酶链反应(qRT-PCR)检测NSCLC组织和细胞中LUCAT1、miR-937-5p和MMP-13 mRNA相对表达水平。将A549细胞分为Control组、sh-NC组、sh-LUCAT1组、sh-LUCAT1+anti-miR-937-5P组、sh-LUCAT1+OE-MMP-13组。并进行相应转染处理后,qRT-PCR和蛋白印迹检测转染效率,CCK-8和BrdU检测细胞活力和增殖;Transwell检测细胞迁移。双荧光素酶用于验证LUCAT1、miR-937-5p和MMP-13之间关系。异种移植肿瘤实验用于证实LUCAT1对肿瘤生长的影响,分为sh-NC组和sh-LUCAT1组。结果 LUCAT1和MMP-13 mRNA在NSCLC组织和细胞系中高表达,而miR-937-5p表达下调(P<0.05)。敲低LUCAT1在体外抑制A549细胞增殖和迁移,并在体内抑制肿瘤生长(P<0.05)。miR-937-5p被预测并被鉴定为LUCAT1的直接靶标,MMP-13被预测并被鉴定为miR-937-5p的靶基因,LUCAT1可通过miR-937-5p调控MMP-13表达(P<0.05)。抑制miR-937-5p或过表达MMP-13可部分逆转敲低LUCAT1在体外对细胞增殖和迁移的抑制作用(P<0.05)。结论 敲低LUCAT1通过靶向miR-937-5p间接下调MMP-13表达,抑制NSCLC细胞增殖和迁移。 展开更多
关键词 长链非编码核糖核酸肺癌相关转录物1 微小RNA-937-5p 基质金属蛋白酶13 非小细胞肺癌 增殖 迁移
下载PDF
Synthesis and structural analysis of ^(13)C-fatty acids
14
作者 WANG Hui-Qiong ZHAO Xia-Ling TANG Guo-Zhong (Shanghai Institute of Nuclear Research, the Chinese Academy of Sciences, Shanghai 201800) 《Nuclear Science and Techniques》 SCIE CAS CSCD 2000年第1期17-21,共5页
The 13C-labeled fatty acids octanoic-1-13C acid and palmitic-1-13C acid were synthetically prepared from Ba 13CO3. The yield of the former was more than 90% and that of the latter was above 85%. MS, IR, 1H-NMR and 13N... The 13C-labeled fatty acids octanoic-1-13C acid and palmitic-1-13C acid were synthetically prepared from Ba 13CO3. The yield of the former was more than 90% and that of the latter was above 85%. MS, IR, 1H-NMR and 13NMR were performed to analyze the structures of the two 13C-fatty acids, compared with their unlabeled fatty acids. 展开更多
关键词 13脂肪酸 合成 结构表征 质谱 红外光谱 核磁共振氢谱 核磁共振碳谱
全文增补中
Al_(13)去除水中腐殖酸的混凝作用机理 被引量:16
15
作者 刘红 王东升 +2 位作者 吕春华 鲁毅强 汤鸿霄 《环境化学》 CAS CSCD 北大核心 2005年第2期121-124,共4页
研究对比了Al_(13)、不同碱化度的聚合氯化铝(PACl)及工业聚合氯化铝等去除水中腐殖酸的絮凝特征,从Zeta电位、RT(余浊)、UV254等角度分别考察了pH值和投药量的影响,对不同形态组成絮凝剂的混凝效能有了进一步明确的认识,并且对Al13的... 研究对比了Al_(13)、不同碱化度的聚合氯化铝(PACl)及工业聚合氯化铝等去除水中腐殖酸的絮凝特征,从Zeta电位、RT(余浊)、UV254等角度分别考察了pH值和投药量的影响,对不同形态组成絮凝剂的混凝效能有了进一步明确的认识,并且对Al13的絮凝机理进行了有益的探索结果表明,Al13是混凝过程中的优势形态。 展开更多
关键词 混凝作用 AL13 腐殖酸 絮凝机理 碱化度 去除 混凝剂 除水 ZETA电位 组成
下载PDF
13-MTD通过激活MAPK途径和抑制Akt存活途径诱导乳腺癌MCF-7细胞凋亡 被引量:13
16
作者 蔡清清 林天歆 +4 位作者 范新兰 尹心宝 董文 黄立 林桐榆 《中国病理生理杂志》 CAS CSCD 北大核心 2009年第5期873-876,共4页
目的:探讨侧链饱和脂肪酸13-甲基十四烷酸(13-MTD)诱导人乳腺癌MCF-7细胞凋亡的作用机制。方法:140mg/L13-MTD处理体外培养的人乳腺癌MCF-7细胞和人乳腺正常细胞,采用流式细胞仪检测技术观察13-MTD对人乳腺癌MCF-7细胞凋亡的影响,免疫... 目的:探讨侧链饱和脂肪酸13-甲基十四烷酸(13-MTD)诱导人乳腺癌MCF-7细胞凋亡的作用机制。方法:140mg/L13-MTD处理体外培养的人乳腺癌MCF-7细胞和人乳腺正常细胞,采用流式细胞仪检测技术观察13-MTD对人乳腺癌MCF-7细胞凋亡的影响,免疫印迹法检测13-MTD处理后细胞内c-Jun氨基末端激酶(JNK),p38,Fas相关死亡结构域蛋白(FADD)和丝氨酸/苏氨酸蛋白激酶(Akt)等蛋白磷酸化变化。结果:流式细胞仪实验结果显示13-MTD能有效地诱导人乳腺癌MCF-7细胞凋亡,但不引起正常人乳腺上皮细胞凋亡。免疫印迹检测显示经13-MTD处理后的人乳腺癌MCF-7细胞JNK和p38磷酸化蛋白明显增加,Akt磷酸化蛋白明显减少。结论:13-MTD是一个新的安全高效抗肿瘤药物,其作用机制可能是通过激活MAPK途径和抑制Akt存活途径来诱导肿瘤细胞凋亡。 展开更多
关键词 乳腺肿瘤 细胞凋亡 13-甲基十四烷酸
下载PDF
工业专用高芥酸油菜新品种绵油13号的选育 被引量:12
17
作者 袁代斌 蒲定福 +3 位作者 蒙大庆 李芝凡 胥岚 郭子荣 《中国油料作物学报》 CAS CSCD 北大核心 2003年第3期85-87,共3页
工业专用甘蓝型高芥酸油菜绵油13号,系采用阶梯式复合杂交,经过多年优良基因重组逐渐积累育成。具有芥酸含量高(55.88%)、含油率高、丰产性较好、抗倒耐病力强、适应性广等优点,适宜在四川省的平丘区及其他类似生态区种植。
关键词 工业专用高芥酸油菜 绵油13号品种 选育 阶梯式复合杂交 亲本组配 产量性状 特征特性 推广应用 市场前景 栽培要点
下载PDF
多元羧酸与木材酯化反应的固体核磁共振谱CPMAS^(13)CNMR的表征 被引量:12
18
作者 方桂珍 李坚 +2 位作者 孔漫 上原徹 古野毅 《林业科学》 EI CAS CSCD 北大核心 2001年第2期108-111,共4页
本研究要用以多元羧酸为酯化剂 ,以无机盐为催化剂的交联体系。这一体系是新型的、水溶的、无毒害、无污染的非甲醛系试剂并联体系。本文采用固体核磁共振谱CP MAS1 3 CNMR ,测定木材主要组分酯化反应的CP MAS1 3 CNMR波谱 ,归属主要谱... 本研究要用以多元羧酸为酯化剂 ,以无机盐为催化剂的交联体系。这一体系是新型的、水溶的、无毒害、无污染的非甲醛系试剂并联体系。本文采用固体核磁共振谱CP MAS1 3 CNMR ,测定木材主要组分酯化反应的CP MAS1 3 CNMR波谱 ,归属主要谱线 ,分析了多元羧酸与木材交联反应过程中主要组分的化学结构变化。结果表明 :酯化反应后 ,羧基碳的比率增加 ;芳香族碳和羟基碳的比率减少 ;烷基碳的变化随着羧基碳的变化而改变。 展开更多
关键词 多元羧酸 木材 酯化反应 固体核磁共振谱 化学成分 科学结构
下载PDF
13-甲基十四烷酸诱导膀胱癌细胞株T24凋亡的机制研究 被引量:5
19
作者 尹心宝 林天歆 +4 位作者 许可慰 黄海 江春 韩金利 黄健 《中国病理生理杂志》 CAS CSCD 北大核心 2009年第7期1266-1270,共5页
目的:研究13-甲基十四烷酸诱导膀胱癌T24细胞凋亡的作用,探讨其可能的机制。方法:将不同浓度的13-甲基十四烷酸作用于膀胱癌T24细胞,用MTT法检测细胞增殖,流式细胞仪(FCM)检测细胞周期,TUNEL法检测细胞凋亡指数,蛋白免疫印迹法分析参与... 目的:研究13-甲基十四烷酸诱导膀胱癌T24细胞凋亡的作用,探讨其可能的机制。方法:将不同浓度的13-甲基十四烷酸作用于膀胱癌T24细胞,用MTT法检测细胞增殖,流式细胞仪(FCM)检测细胞周期,TUNEL法检测细胞凋亡指数,蛋白免疫印迹法分析参与凋亡的蛋白。结果:药物处理2h后p38、JNK磷酸化增强,AKT磷酸化减弱,8h后线粒体中细胞色素C释放,FADD及磷酸化FADD没有明显变化,caspase酶底物PARP、lamin B、RB在12h出现明显的裂解片段,且药物诱导T24细胞凋亡的过程有时间浓度依赖效应。结论:在13-MTD诱导T24细胞凋亡的过程中p38MAPK和JNK/SAPK信号通路被激活,PI3K/AKT信号通路被抑制,进而激活线粒体凋亡途径,使线粒体内的细胞色素C释放到胞浆,激活caspase酶,裂解相应的凋亡底物laminB、Rb、PARP,促进T24细胞凋亡。 展开更多
关键词 膀胱肿瘤 13-甲基十四烷酸 细胞凋亡 信号转导
下载PDF
不同时期叶面喷施萘乙酸对秋芝麻品种赣芝13号产量及种子质量的影响 被引量:5
20
作者 孙建 熊书敏 +5 位作者 皮晓玲 乐美旺 饶月亮 颜廷献 颜小文 周红英 《南方农业学报》 CAS CSCD 北大核心 2018年第7期1318-1323,共6页
【目的】探讨苗期和花期叶面喷施萘乙酸(NAA)对秋芝麻产量及种子质量的影响,为秋芝麻高产栽培和种子繁育提供理论参考。【方法】以秋芝麻品种赣芝13号为试验材料,设叶面喷施清水(CK)及苗期(T1)、花期(T2)及苗期和花期重复喷施(T3)10 mg/... 【目的】探讨苗期和花期叶面喷施萘乙酸(NAA)对秋芝麻产量及种子质量的影响,为秋芝麻高产栽培和种子繁育提供理论参考。【方法】以秋芝麻品种赣芝13号为试验材料,设叶面喷施清水(CK)及苗期(T1)、花期(T2)及苗期和花期重复喷施(T3)10 mg/L NAA溶液4个处理,成熟后测定上、中、下部蒴果的每蒴粒数及粒重等产量性状,并测定不同部位种子的发芽性状。【结果】不同时期叶面喷施NAA均能促使秋芝麻赣芝13号的株高和始蒴高度变高,空稍尖长度和果轴长度变长,单株蒴果数和每蒴粒数增加,但均与CK差异不显著(P>0.05,下同)。与CK相比,不同时期叶面喷施NAA后,T1、T2和T3处理的千粒重分别增加5.58%、5.15%和6.44%,单株产量分别增加8.76%、5.15%和16.24%,单位面积产量分别增加10.96%、10.97%和24.72%,差异均达显著水平(P<0.05,下同)。叶面喷施NAA还能显著增加赣芝13号植株上部蒴果的每蒴粒数和千粒重,显著提高上部蒴果种子的发芽率、苗高、根长和苗鲜重,提高种子质量,均以T3处理的效果较佳;但对中部和下部蒴果的相关性状影响不显著。【结论】叶面喷施NAA能显著提高赣芝13号的千粒重和单株产量,达到显著增产效果,苗期和花期重复喷施的作用效果优于苗期或花期单次喷施,其主要体现在显著提高上部蒴果的每蒴粒数和籽粒千粒重,使种子质量显著提高。 展开更多
关键词 秋芝麻 赣芝13 萘乙酸 生育时期 产量 种子质量
下载PDF
上一页 1 2 12 下一页 到第
使用帮助 返回顶部