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991.
A novel electrochemical method for the sequence-specific detection of double-stranded polymerase chain reaction (PCR) products of PML/RARα fusion gene in acute promyelocytic leukemia (APL) was described in detail. Based on a “sandwich” sensing mode involving a pair of locked nucleic acids probes (capture probe and reporter probe), this DNA sensor exhibited excellent selectivity and specificity. The direct and quantitative analysis of double-stranded complementary was firstly performed by our sensor without the use of alkali, helicase enzymes, or denaturants. Finally, combining PCR technique with electrochemical detection scheme, PCR amplicons (191 bp) of the PML/RARα fusion gene were obtained and rapidly identified with a low detection limit of 79 fmol in the 100-μL hybridization system. The results clearly showed the power of sensor as a promising tool for the sensitive, specific, and portable detection of APL and other diseases.  相似文献   
992.
Silanol groups on a silica surface affect the activity of immobilized catalysts because they can influence the hydrophilicity/hydrophobicity, matter transfer, or even transition state in a catalytic reaction. Previously, these silanol groups have usually been passivated by using surface‐passivation reagents, such as alkoxysilanes, bis‐silylamine reagents, chlorosilanes, etc., and surface passivation has typically been found in mesoporous‐silicas‐supported molecular catalysts and heteroatomic catalysts. However, this property has rarely been reported in mesoporous‐silicas‐supported metal‐nanoparticle catalysts. Herein, we prepared an almost‐superhydrophobic SBA‐15‐supported gold‐nanoparticle catalyst by using surface passivation, in which the catalytic activity increased more than 14 times for the reduction of nitrobenzene compared with non‐passivated SBA‐15. In addition, this catalyst can selectively catalyze hydrophobic molecules under our experimental conditions, owing to its high (almost superhydrophobic) hydrophobic properties.  相似文献   
993.
By taking advantage of UV‐Raman spectroscopy and high‐resolution TEM (HRTEM), combined with the focused ion beam (FIB) technique, the transformation from GaOOH into α‐Ga2O3 and then into β‐Ga2O3 was followed. We found that the stepwise transformations took place from the surface region before developing into the bulk of single particles without particle agglomeration and growth. During the transformation from GaOOH into α‐Ga2O3, the elimination of water vapor through the dehydroxylation of GaOOH resulted in the formation of micropores in the single particles, whilst maintaining their particle size. For the phase transformation from α‐Ga2O3 into β‐Ga2O3, the nucleation of β‐Ga2O3 was found to occur at the surface defects and this process could be retarded by occupying these defects with a small amount of La2O3. By finely controlling the process of the phase transformation, the β‐Ga2O3 domains gradually developed from the surface into the bulk of the single particles without particle agglomeration. Therefore, the surface structure of the α‐Ga2O3 single particles can be easily tuned and a particle with an α@β core–shell phase structure has been obtained.  相似文献   
994.
The reactions of E powder (E=S, Se) with a mixture of Cr(CO)6 and Mn2(CO)10 in concentrated solutions of KOH/MeOH produced two new mixed Cr? Mn? carbonyl clusters, [E2CrMn2(CO)9]2? (E=S, 1 ; Se, 2 ). Clusters 1 and 2 were isostructural with one another and each displayed a trigonal‐bipyramidal structure, with the CrMn2 triangle axially capped by two μ3‐E atoms. The analogous telluride cluster, [Te2CrMn2(CO)9]2? ( 3 ), was obtained from the ring‐closure of Te2Mn2 ring complex [Te2Mn2Cr2(CO)18]2? ( 4 ). Upon bubbling with CO, clusters 2 and 3 were readily converted into square‐pyramidal clusters, [E2CrMn2(CO)10]2? (E=Se, 5 ; Te, 6 ), accompanied with the cleavage of one Cr? Mn bond. According to SQUID analysis, cluster 6 was paramagnetic, with S=1 at room temperature; however, the Se analogue ( 5 ) was spectroscopically proposed to be diamagnetic, as verified by TD‐DFT calculations. Cluster 6 could be further carbonylated, with cleavage of the Mn? Mn bond to produce a new arachno‐cluster, [Te2CrMn2(CO)11]2? ( 7 ). The formation and structural isomers, as well as electrochemistry and UV/Vis absorption, of these clusters were also elucidated by DFT calculations.  相似文献   
995.
A high-performance liquid chromatography coupled with photodiode array detection and electrospray ionization tandem mass spectrometry (HPLC-PAD–ESI-MS) method has been developed for the simultaneous identification and quantification of active compounds (rutin and quercetin) contained in Traditional Chinese Medicine (TCM) Euonymus alatus (Thunb.) Siebold (EAS). The herb samples from ten main origins and five medicinal portions (leaf, fruit, stem, pterygium and root) were investigated. The separation was performed on a Shim C18 column at 30 °C with an isocratic elution. Methanol (A) and water (0.5% methanoic acid, v/v) (B) were used as mobile phases. The recoveries of the two compounds were 100.184% and 100.417%, respectively, and all of them showed good linearity (r2 ? 0.9993) in relatively wide concentration ranges. The developed method was applied to identify and quantify the two major active compounds in the collected herb samples, and the results indicated that contents of the two compounds in EAS varied significantly from habitat to habitat. It was demonstrated that the proposed method was helpful for the quality evaluation of EAS.  相似文献   
996.
The lanthanum(III) complexes tris(3,5‐diphenylpyrazolato‐κ2N,N′)tris(tetrahydrofuran‐κO)lanthanum(III) tetrahydrofuran monosolvate, [La(C15H11N2)3(C4H8O)3]·C4H8O, (I), and tris(3,5‐diphenyl‐1,2,4‐triazolato‐κ2N1,N2)tris(tetrahydrofuran‐κO)lanthanum(III), [La(C14H10N3)3(C4H8O)3], (II), both contain LaIII atoms coordinated by three heterocyclic ligands and three tetrahydrofuran ligands, but their coordination geometries differ. Complex (I) has a mer‐distorted octahedral geometry, while complex (II) has a fac‐distorted configuration. The difference in the coordination geometries and the existence of asymmetric La—N bonding in the two complexes is associated with intramolecular C—H...N/O interactions between the ligands.  相似文献   
997.
In the title CuII complex, [Cu(C19H14O3P)2(C3H7NO)(H2O)2], the molecule is bisected by a twofold axis relating the two 2‐(diphenylphosphoryl)benzoate (ODPPB) ligands. The asymmetric unit consists of a CuII metal centre on the symmetry axis, an ODPPB ligand, one water ligand and one dimethylformamide (DMF) ligand (disordered around the twofold axis). The CuII ion has fivefold coordination provided by two carboxylate O atoms from two ODPPB ligands, two O atoms from two coordinated water molecules and another O atom from a (disordered) DMF molecule, giving a CuO5 square‐pyramidal coordination geometry. The ODPPB ligand adopts a terminal monocoordinated mode with two free O atoms forming two strong intramolecular hydrogen bonds with the coordinated water molecules, which may play a key role in the stability of the molecular structure, as shown by the higher release temperature for the coordinated water molecules than for the coordinated DMF molecule. The optical absorption properties of powder samples of the title compound have also been studied.  相似文献   
998.
A one‐dimensional AgI coordination complex, catena‐poly[[silver(I)‐μ‐{2‐[2‐(pyridin‐4‐yl)‐1H‐benzimidazol‐1‐ylmethyl]phenol‐κ2N2:N3}] perchlorate monohydrate], {[Ag(C19H15N3O)]ClO4·H2O}n, was synthesized by the reaction of 2‐[2‐(pyridin‐4‐yl)‐1H‐benzimidazol‐1‐ylmethyl]phenol (L) with silver perchlorate. In the complex, the L ligands are arranged alternately and link AgI cations through one benzimidazole N atom and the N atom of the pyridine ring, leading to an extended zigzag chain structure. In addition, the one‐dimensional chains are extended into a three‐dimensional supramolecular architecture via O—H...O hydrogen‐bond interactions and π–π stacking interactions. The complex exhibits photoluminescence in acetonitrile solution, with an emission maximum at 390 nm, and investigation of the thermal stability reveals that the network structure is stable up to 650 K.  相似文献   
999.
Nano-montmorillonites belong to aluminosilicate clay minerals with innocuity, high specific surface area, ion exchange, and favorable adsorption property. Due to the excellent properties, montmorillonites can be used as labels for the electrochemical immunosensors. In this study, nano-montmorillonites were converted to sodium montmorillonites (Na-Mont) and further utilized for the immobilization of thionine (TH), horseradish peroxidase (HRP) and the secondary anti-zeranol antibody (Ab2). The modified particles, Na-Mont-TH-HRP-Ab2 were used as labels for immunosensors to detect zeranol. This protocol was used to prepare the immunosensor with the primary antibody (Ab1) immobilized onto the nanoporous gold films (NPG) modified glassy carbon electrode (GCE) surface. Within zeranol concentration range (0.01–12 ng mL−1), a linear calibration plot (Y = 0.4326 + 8.713 X, r = 0.9996) was obtained with a detection limit of 3 pg mL−1 under optimal conditions. The proposed immunosensor showed good reproducibility, selectivity, and stability. This new type of immunosensors with montmorillonites and NPG as labels may provide potential applications for the detection of zeranol.  相似文献   
1000.
Tunable polymerization of ionic liquid on the surfaces of multi-walled carbon nanotubes (MWCNTs) was achieved by a mild thermal-initiation-free radical reaction of 3-ethy-1-vinylimidazolium tetrafluoroborate in the presence of MWCNTs. Successful modification of polymeric ionic liquid (PIL) on MWCNTs surfaces (PIL-MWCNTs) was demonstrated by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and X-ray photoelectron spectroscopy. The resulting PIL-MWCNTs possessed unique features of high dispersity in aqueous solution and tunable thickness of PIL layer, due to positive imidazole groups along PIL chains and controllable ionic liquid polymerization by tuning the ratio of precursor. Based on cation-π interaction between the positive imidazole groups on PIL-MWCNTs surface and hydroquinone (HQ) or catechol (CC), excellent discrimination ability toward HQ and CC and improved simultaneous detection performance were achieved. The linear range for HQ and CC were 1.0 × 10−6 to 5.0 × 10−4 M and 1.0 × 10−6 to 4.0 × 10−4 M, respectively. The detection limit for HQ was 4.0 × 10−7 M and for CC 1.7 × 10−7 M (S/N = 3), correspondingly.  相似文献   
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