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1.
由聚[2′-氯乙基-2,3-环硫丙基醚]和多乙烯声胺反应,合成了四种以聚硫醚为主链的氧杂多乙烯多胺型螯合树脂,它们对贵金属离子Au(Ⅲ)、Pd(Ⅱ)、Pt(Ⅳ)、Ag~+等具有优良的吸附性能。  相似文献   

2.
Developing new acceptor materials as alternatives to fullerene acceptors remains a challenge in the field of organic photovoltaics. We report on the synthesis and optoelectronic properties of three acceptor polymers bearing diketopyrrolopyrrole units in the main chain (PA, PB and PC). Their performance as the acceptor material in bulk heterojunction solar cells using P3HT as the donor material has been tested. The solar cells show relatively high open-circuit voltages (≥0.9 V) but low fill factors and short-circuit current densities limit the photovoltaic device performance. Formation of free charge carriers and low electron mobility are identified as the major obstacles. In blends of P3HT with PA or PB charge formation is limited, while for the P3HT:PC blend photogenerated charges recombine into the PC triplet state before they can separate, unless assisted by a reverse electric field.  相似文献   

3.
In this study, the effects of Peucedanum praeruptorum DUNN methanolic extract (PPME) and its major constituents on SGC7901 human gastric cancer cells were evaluated. Two pyranocoumarins, namely, (±) praeruptorin A (PA) and (±) praeruptorin B (PB), were isolated from PPME. A high performance liquid chromatographic (HPLC) method was developed to determine the contents of PA and PB in PPME. The anti-proliferative and cytotoxic actions of PPME were observed using the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and release of lactate dehydrogenase (LDH) assays. At 300 μg/mL, PPME inhibited cell growth by 51.2% (P < 0.01), probably linked to the high concentration of PA and PB. Both PA and PB exhibited antiproliferative and cytotoxic activities on the SGC7901 cells. Furthermore, the active principle compound, PA, also enhanced the actions of doxorubincin (DOX) on SGC7901 cells. Cell growth decreased higher with the combined treatment of PA and DOX than that with the chemotherapy agent applied alone, suggesting that PA could reduce the dose of DOX for the desired effects.  相似文献   

4.
Changes in serum lipidome and in tissue lipidome are associated with cancer. In this study, tissue mass spectrometry imaging (MSI) and serum lipid profiling by matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) were performed to investigate significantly changed lipids in both tumor (malignant thyroid cancer (MTC) and benign thyroid tumor (BTT)) tissues and sera. Y-scatterplots of variable importance in the projection (VIP) values vs. fold change values indicate that change trends in the levels of ten lipids (i.e., phosphatidylcholine (PC)(34:1), PC(36:1), PC(38:6), phosphatidic acid (PA) (36:2), PA(36:3), PA(38:3), PA(38:4), PA(38:5), PA(40:5), and sphingomyelin (SM)(34:1)) in both tissues and sera from MTC patients, BTT patients, and normal individuals are significantly associated with these three types of pathophysiological status. In order to examine their diagnostic ability, 289 serum samples from 124 MTC patients, 43 BTT patients, and 122 normal controls were randomly divided into the training set and validation set. A biomarker of PC(34:1) exhibited excellent diagnostic ability to differentiate both MTC and BTT patients from normal individuals, with an area under the receiver operating characteristic (ROC) curve value of 0.984, a sensitivity of 96.4 %, and a specificity of 92.7 %. A panel which included PA(36:3) and SM(34:1) could distinguish between MTC and BTT, with an area under receiver operating characteristic curve (AUC) of 0.961, a sensitivity of 87.8 %, and a specificity of 92.9 %. It is worth noting that a panel consisting of PC(34:1), PA(36:3), and SM(34:1) could differentiate MTC patients from both BTT patients and normal individuals, with an AUC of 0.841, a sensitivity of 86.6 %, and a specificity of 75.5 %.
Figure
Comparison of tissue lipid Profiling and serum lipid profiling using MALDI-FTICR MS to select thyroid disease-specific lipids  相似文献   

5.
由聚环硫氟丙烷与多乙烯多胺反应制得的聚合物(PB)再与环硫丙烷反应,合成了四种以聚硫醚为主链的异丙巯基胺树脂(PBM_1-4)。树脂对Au~(3+)、Pd~(2+)、Pt~(4+)、Ag~+和Hg~(2+)等离子具有强的吸附能力,对Cu~(2+)次之,对Zn~(2+)和Pb~(2+)很弱。树脂对贵金属具有高的选择性,能从含Au~(3+)、Cr~(3+)、Co~(2+)、Ni~(2+)、Cu~(2+)、Mn~(2+)、Zn~(2+)和Fe~(3+)的溶液中定量吸附Au~(3+)而不吸附其它离子。  相似文献   

6.
Abstract

Membrane phospholipids were extracted using a modified Folch, Lees and Sloane-Stanley method, from 21 different algae species covering three major divisions of the protista kingdom. In the modified method after chloroform/methanol (2:1 v/v) extraction and filtration, the solution was backwashed with K-EDTA, 0.6 M, instead of KCl, 1 M. Because algae samples are eavily loaded with cations that broaden NMR signals, the K-EDTA wash results in more highly resolved NMR signals. Following rotary evaporation, the crude algae lipid extract was dissolved in the chloroform-benzene(d6)/methanol-CsEDTA (2:l ml/ml) reagent and analyzed using a 500 MHz NMR spectrophotometer. Phospholipid chemical shifts were determined relative to standard phosphoric acid (85%), following the UIPAC convention. The internal reference used was phosphatidylcholine (PC, -0.84 δ) Division chlorophyta (8 sps.) yields phospholipid signals for phosphatidylglycerol (PG, 0.50), phosphatidic acid (PA, 0.25), cardiolipin (CL, 0.18), phosphatidylethanolamine (PE, 0.03), sphyngomyelin (SPH, -0.09), phosphatidylinositol (PI, -0.37) and PC; the lysoderivatives for lyso PG (LPG, 1.09) and lyso PC (LPC, -0.28), and one uncharacterized signal at 0.32. Phosphatidylserine (PS -0.05) and plasmalogens were not detected. Division rhodophyta (10 sps.) shows signal from PG, PA, CL, PE, SPH, PI, and PC; the lysoderivatives of lyso PA (LPA, 0.83), lyso PE (LPE, 0.43) and LPC; the plasmalogens PC plasmalogen (PC plas, -0.77), LPC plas (-0.20), and l-0-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (PAF-acether, -0.70); and an uncharacterized signal at -40 δ chemical shift. PS was not detected. Division Phaeophytas (3 sps.) showed signals for PG, PA, CL, PE, SPH, PI, and PC and lysoderivatives of LPG, LPA, LPE plas (0.53), LPE, LPC plas, and LPC. PS, PAF-acether and the uncharacterized signals at 0.32 δ and -0.40 δ were not detected.  相似文献   

7.
The effect of native cyclodextrins (alpha, beta, or gammaCD with six, seven and eight glucose units, respectively), hydroxypropyl-beta-cyclodextrin (HPCD), chitosan (CHT) and glucose in water solution or water with n-propylamine (PA) as co-solvent upon the UV-vis and fluorescence properties of poorly fluorescent N-methyl carbamates pesticides (C) as bendiocarb (2,2-dimethyl-1,3-benzodioxol-4-ol methylcarbamate, BC) and promecarb (3-methyl-5-(1-methylethyl)phenol methylcarbame, PC) was examined. Fluorescent enhancement was found for both substrates with all CDs in water or PA-water except from PC with alphaCD. The addition of CHT increases the fluorescence of BC but decreases the fluorescence of PC, and glucose addition gives in both cases no spectral changes. Host-guest interaction was clearly determined by fluorescence enhancement with betaCD and HPCD with a 1:1 stoichiometry for the complexes (C:CD). The values obtained for the association constants (K(A), M(-1)) were (6+/-2)x10(2) and (2.3+/-0.3)x10(2) for BC:betaCD and BC:HPCD complexes, respectively. For PC:betaCD and PC:HPCD the values of K(A) were (19+/-2)x10(2) and (21+/-2)x10(2), respectively. The ratio of the fluorescence quantum yields for the bound and free substrates (phi(CCD)/phi(C)) was in the range 1.74-3.8. The limits of detection (L(D), microg mL(-1)) for the best conditions were (0.57+/-0.02) for BC with HPCD and (0.091+/-0.002) for PC with betaCD in water. Application to the analysis in pesticide spiked samples of tap water and fruit yields satisfactory apparent recoveries (84-114%), and for the extraction procedure in fruits and a commercial formulation, recoveries were of 81-98% and 104%, respectively. The method is rapid, simple, direct, sensitive and useful for pesticide analysis.  相似文献   

8.
Two new germacrane‐type sesquiterpenoids bearing an epoxy ring, myrrhanolide D ( 1 ) and myrrhasin A ( 2 ), together with eight known compounds, 3 – 10 , were isolated from the resinous exudates of Commiphora opobalsamum. Their structures were elucidated based on the analyses of their spectroscopic data. The isolated compounds 1, 2, 6 , and 8 were evaluated for their cytotoxic activities against human prostate cancer DU145 and PC3 cells.  相似文献   

9.
A new lipid nano-emulsion (LNE) was prepared from soybean oil and phosphatidylcholine (PC) employing two cosurfactants, sodium palmitate (PA) for reduced droplet size and sucrose palmitate (SP) for stability enhancement. The mean droplet size of LNEs prepared at a PA/PC (w/w) ratio of larger than 1/10 was found to be ca. 50 nm by dynamic light scattering and atomic force microscopy. However, during the 12-month storage, the PA/PC (1/10)-LNE showed an increase in mean droplet size and broadening of the droplet size distribution due to coalescence of the LNE particles. In a saline solution, the coalescence proceeded very rapidly, i.e., the mean droplet size increased to more than 150 nm within 0.5 h. To suppress the coalescence of LNE particles, four sucrose fatty acid esters of different chain lengths were examined as candidate cosurfactants. The results showed that PA/SP/PC (1/4/10)-LNE could maintain a mean droplet size around 50 nm for 12 months. In a saline solution, the mean droplet size could be maintained within 100 nm even after 24 h. Slight formation of flocculation in the LNEs depending on the storage period was suggested by measurement of the 31P nuclear magnetic resonance line width of the LNEs.  相似文献   

10.
PC/尼龙6共混合金的结晶结构与性能   总被引:11,自引:1,他引:10  
聚碳酸酯(PC)由于具有突出的冲击韧性、良好的透明性、尺寸稳定性和电气绝缘性而广泛应用于电子电气、仪器仪表、汽车、机械、医疗、照明和建筑等领域,是一种综合性能优良的工程塑料.但也存在着加工流动性差和耐药性差、易应力开裂及对缺口敏感等缺陷,且价格昂贵,因而限制了它的应用范围.对PC进行合金化,提高PC的性能,降低成本是PC改性的重要研究方向,开发成功的PC合金有PC/ABS,PC/PET,PC/PBT[1]和PC/PE[2]等.制备高性能PC/尼龙6(PA6)合金是目前国内外PC改性的热点.PA6的加入可以改善PC的耐药性、耐应力开裂性及加工性能,降…  相似文献   

11.
The effect of phenobarbital (PB) or amitriptyline (AMT) on phospholipid metabolism was studied in rat liver. Administration of PB or AMT caused a marked increase in the microsomal phosphatidylcholine (PC) content. In this context, the activities of glycerophosphate acyltransferase (GAT), phosphatidate cytidylyltransferase (PCT), phosphatidate phosphohydrolase (PPH) and choline phosphotransferase (CPT) in the liver were all increased by PB. In contrast, the activities of GAT and PCT were little affected by AMT, while those of PPH and CPT were significantly increased by AMT. These findings suggest that AMT or PB would increase hepatic microsomal PC synthesis through inducing PPH and then CPT.  相似文献   

12.
Dicyclohexano-18-crown-6 (DCH18C6) aqueous solution was irradiated using 60Co source and precipitates containing yellow transparent blocks (PA) and powders (PB) were obtained. TGA analysis confirms that both PA and PB have higher thermal stability than DCH18C6. Both DSC and GPC results suggest that PA might be oligomer and PB were ultrahigh molecular weight polymers. The FTIR spectra indicate that both PA and PB have similar chemical structures containing carboxyl and hydroxyl groups. By using scavengers, it was found that the formation of PA and PB is attributed to the radiation-induced radical polymerization of DCH18C6, and ·OH radical produced by water radiolysis might be a critical species for the formation of PA and PB. These studies help to understand the radiation chemistry behavior of DCH18C6 in the reprocessing of nuclear fuel.  相似文献   

13.
We have synthesized three new donor–acceptor‐type monomers to achieve soluble and processable low‐band gap polymers, 4,7‐bis(4‐octyl‐2‐thienyl)‐2,1,3‐benzothiadiazole (B4TB), 4,7‐bis(3‐octyl‐2‐thienyl)‐2,1,3‐benzothiadiazole (B3TB), and 4‐(3‐octyl‐2‐thienyl)‐7‐(4‐octyl‐2‐thienyl)‐2,1,3‐benzothiadiazole (B34TB), by the Suzuki coupling reaction. Using B4TB and B3TB, two soluble high molecular weight regioregular head‐to‐head and tail‐to‐tail polymers poly[4,7‐bis(4‐octyl‐2‐thienyl)‐2,1,3‐ benzothiadiazole] (PB4TB) and poly[4,7‐bis(3‐octyl‐2‐thienyl)‐2,1,3‐benzothiadiazole] (PB3TB) were prepared via iron(III) chloride‐mediated oxidative polymerization. The structures of the polymers were confirmed by 1H and 13C NMR, and the molecular weights were determined by size exclusion chromatography. The optical properties (absorbance and fluorescence) of the monomers and polymers were studied and compared with unsubstituted analogues. The monomers and polymers bearing octyl substituents on the thiophene rings pointing away from the benzothiadiazole units (B4TB and PB4TB) possess a more planar structure, and their optical spectra appear redshifted as compared with those having the octyl chain nearer to the benzothiadiazole (B3TB and PB3TB). The optical band gaps of PB3BT (Eg = 2.01 eV) and PB4BT (Eg = 1.96 eV), however, are at much higher energy levels than that of the unsubstituted electrochemically polymerized PBTB material (Eg = 1.1–1.2 eV) as a result of steric effects of the octyl chains. The electrochemical properties of the monomers and polymers were examined using cyclic voltammetry and reflect the effect of alkyl substitution. B4TB and PB4TB were oxidized at a lower potential than B3TB and PB3TB, whereas their reduction potentials were less negative. The electrochemical band gap calculated from the onset of the reduction and oxidation process agreed with the optical band gap calculated from the absorption edges. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 251–261, 2002  相似文献   

14.
15.
A new iridoid glycoside, gelsemiol 6'-trans-caffeoyl-1-glucoside (1), was isolated from Verbena littoralis, together with four known phenylethanoid glycosides, acteoside (2), 2'-acetylacteoside (3), jionoside (4), and isoverbascoside (5). Their structures were elucidated by spectral data. Compound 1 showed weak enhancement of nerve growth factor (NGF)-mediated neurite outgrowth from PC12D cells.  相似文献   

16.
From the reactions between M(2)(T(i)PB)(4), where T(i)PB = 2,4,6-triisopropylbenzoate and two equivalents each of 2-furan carboxylic acid, FuCO(2)H, and 2-selenophene carboxylic acid, SpCO(2)H in toluene, the new compounds trans-M(2)(T(i)PB)(2)(O(2)CFu)(2) (1a M = Mo, 2a M = W) and trans-M(2)(T(i)PB)(2)(O(2)CSp)(2) (1b M = Mo, 2b M = W) were formed. These new compounds have been characterized by (1)H NMR, steady-state UV-Vis-NIR absorption and emission spectroscopy, cyclic and differential pulse voltammetry, and fs and ns transient absorption spectroscopy. The compound Mo(2)(T(i)PB)(2)(O(2)CSp)(2) (1b) has been characterized by single crystal X-ray crystallography. These data are compared with those previously reported for related 2-thiophene carboxylate derivatives: M(2)(T(i)PB)(2)(O(2)CTh)(2). The physico-chemical data correlate well with electronic structure calculations performed on model compounds. All compounds have detectible S(1) photoexcited states with lifetimes that vary from ~5 ps to < 1 ps. The molybdenum compounds have T(1) states with microsecond lifetimes that are assigned as MMδδ* whereas the T(1) states for tungsten are (3)MLCT with lifetimes on the order of nanoseconds. In all cases, shorter lifetimes were seen in complexes containing heavier atoms.  相似文献   

17.
设计合成了3条棕榈酸修饰的两亲性多肽C15H31CO-(AEELAKK)3-NH2(PA1), C15H31CO-(AEALAKK)3-NH2(PA2) 和C15H31CO-(AEELAKA)3-NH2(PA3), 研究了其在水溶液中的自组装行为以及带净正电荷的PA2 和带净负电荷的PA3 等比例混合后的共组装行为, 并推测了其机理. 圆二色谱分析结果表明, 其二级结构均为α-螺旋结构, PA2和PA3等比例混合后α-螺旋含量升高. 利用透射电镜观察了PA1, PA2, PA3以及PA2+PA3(体积比1: 1)自组装体的形貌, 结果表明, PA2和PA3等比例混合后共组装形成了长的纳米纤维. 芘荧光探针研究了3种两亲性多肽以及PA2+PA3 的临界胶束浓度.  相似文献   

18.
Step acid dissociation reactions of benzodiamyloxyl (X) and thiadiazole (Y) porphyrazine (H2PA) derivatives H2PA(X)4, H2PA(X)3(Y), H2PA(X)2(Y)2, H2PA(X)(Y)3, and H2PA(Y)4 were studied theoretically (MP3) and experimentally (spectropotentiometrically) in the H2L-(K[2.2.2])OH-DMSO system for the series H2P (porphin), H2P(μs-Pr)4, H2P(μs-Ph)4, H(N-Me)P(μs-Ph)4, H2TBP (tetrabenzoporphin), H2TBP(μs-Ph)4, H2PA (porphyrazine), H2PA(β-Ph)4, H2PC (phthalocyanine), and H2PC(t-Bt)4. The linear correlation pK a1 298 = 0.32622ΔH°a1(g) ? 94.62 (R = 0.998) was observed for H2PA and its symmetrical derivatives H2PA(β-Ph)4, H2PC, H2PC(t-Bt)4, H2PC(X)4, and H2PC(Y)4. Deviations of the proportionality factors in the pK a1 298 = bH°a1(g) + A dependences from the theoretical value (2.303RT)?1 were explained by medium effects. Substituent effects on pK a1 298 were divided into internal δ(R i)int and external δ(R i)ext (solvation) contributions. The compensation dependences δ(R i)ext = ?0.10911δ(R i)int + 0.13 and δ(R i)ext = ?0.52969δ(R i)int (correlation coefficients 0.998) were observed for simple (H2PA, H2TBP, H2P(μs-Ph)4, and H2P(μs-Pr)4) and complex (H(N-Me)P(Ph)4, H2TBP(μs-Ph)4, H2PA(β-Ph)4,H2PA(Y)4, H2PC, H2PC(t-Bt)4, and H2PC(X)4) porphin derivatives, respectively.  相似文献   

19.
Two acetylene polymers containing cyanobiphenyl-based mesogens,poly { 10-[ ((4'- cyano-4-biphenylyl ) oxy ) carbonyl] - 1 -decyne } (PA8CN ), which has a relativelyfiexible polyalkyne backbone, and poly {[4-(((12-((4'-cyano-4-biphenylyl)oxy)dodecyl)oxy)carbonyl) phenyl]-acetylene} (PB12CN), which has a fairly rigid poly (phenylacetylene )backbone, were synthesized using respectively WCl_6 and [Rh(nbd)Cl]_2 as the catalysts.PA8CN exhibits enantiotropic interdigitated smectic A phase (S_(Ad)) over a temperaturerange as wide as ca. 100℃, whereas PB12CN is non-mesomorphic, demonstrating thatthe backbone rigidity plays an important role in determining the liquid crystallinity of thepolyacetylenes.  相似文献   

20.
Two adamantyl-containing oxazoline monomers. 2-(1-adamantyl)-2-oxazoline, A , and 2-(1-adamantylmethyl)-2-oxazoline, B , were synthesized, and polymerized in 1,2-dichlorobenzene to give polymers PA and PB respectively. Both polymers are highly crystalline and showed very high Tm's (269°C for PA and 320°C for PB ) and little solubility in common organic solvents. Annealed PA showed a critical surface tension of 23.6 dyne/cm. PB was not soluble in the many organic solvents tested at room temperature. Due to its high Tm and insolubility, contact angle measurements on PB were impossible. Diblock copolymers based on different weight ratios of A and 2-ethyl-2-oxazoline, E , showed relatively narrow molecular weight distribution (MWD) when methyl p-nitrobenzenesulfonate, I , was used as initiator. After annealing, diblock polymers with B/I = 7, 10, or 12 showed Tm's (200–281°C); after quenching the same samples showed Tc's (160–171°C), which were lower than that of pure PB , 215°C. The quenched diblocks showed single Tg's (63–82°C) which implies that these short blocks are compatible. Diblock polymer with B/I = 5 and E/I = 20 was amorphous and displayed inverse emulsifying ability in styrene + water emulsion polymerization. BEB type triblock polymers prepared using ethylene glycol dinosylate as initiator had broader MWD and higher Tm's compared to their diblock counterparts with the same B/E wt% and B/I ratios. These triblock polymers were not completely soluble in styrene and/or water and therefore could not be used as emulsifying agents.  相似文献   

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