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1.
A novel TiO2 (anatase) containing a large amount of single electron trapped oxygen vacancies (SETOV) was prepared by dehydration of titanic acid nanotubes. This novel TiO2 contains high concentration intrinsic defects in bulk structure, while its surface still remains the stoichiometric structure to protect them. And this novel TiO2 itself has the visible light absorption without any doping, so we call it as the third generation of TiO2 . However, it is regretted that this novel TiO2 (A) only has photocatalytic activity under UV light irradiation, and was inactive for the visible light. The true reasons for this phenomenon were investigated by the transient IR absorption and photoluminescence spectra. Through constructing the foreign electron traps (PdO, PtO2 ), the photocatalytic oxidation of propylene under visible light irradiation was successfully achieved. The removal yield of propylene (C3H6 ) reached 7.6% and 28% on 2 wt.% PtO2 /novel TiO2 and 2 wt.% PdO/novel TiO2 , respectively. By comparison with the noble metal electron traps (Pt, Pd), we found that the effective foreign electron traps need to satisfy two conditions: (1) its work function should situate in the range of Eg(TiO2 ); (2) O2 adsorbes on it undissociatively. This work opens up a new route for the investiga- tion of solar-energy-available TiO2 .  相似文献   

2.
A highly efficient procedure has been developed for the conjugate addition of amines to electron deficient alkenes. The novel ionic liquid [HO3S-bPy][FeCl4] with both Lewis and Brønsted acid sites has been synthesized successfully for the reactions. The results show that the catalyst was very efficient for the conjugate addition of amines to electron deficient alkenes with excellent yields in several minutes. This method has several key features including operational simplicity, no need of any solvent, low cost of the catalyst used, high yields, reusability, excellent chemoselectivity, and wide applicability.  相似文献   

3.
The use of nanotechnology in drug delivery is a rapidly expanding field. Biodegradable or nontoxic nanomaterials have the most promising application potentials in nanomedicine. Herein, we report a novel core-shell nanoparticle with double shell coatings (silica and poly(D,L-lactide-co-glycolide) (PLGA)) with the total shell thickness of (8.7 ± 1.3) nm. The outer shell of PLGA is biodegradable and used for controlled and sustained release, and the inner shell of silica is mesoporous for the preservation of t...  相似文献   

4.
Using a synthetic oligonucleotide (dA-dC)15 as a probe to screen a probe pool made by microdissected human chromosome band 17q11-q12, a DNA fragment containing (CA)16 was isolated, which is a novel short tandem repeat (STR) determined by searching in the GenBank and GDB. It has 8 allelic types with a PIC value of 0.61. The novel STR is conformed with Mendelian segregation according to the linkage analysis of a three-generation neurofibromatosis type Ⅰ (NF1) pedigree. The STR was localized at chromosome band 17q11-q12 in the vicinity of NF1 gene by FISH analysis. The accession number of the STR in GenBank and GDB is G32112 and D17S2204 respectively.  相似文献   

5.
氨基酸分子首次用以制备构筑稀土介孔发光材料.L-丝氨酸通过分子修饰得到新配体2-烟酰氨基-3-羟基丙酸(L),并进一步引入MCM-41介孔基质中,最后和稀土Tb3+离子复合得发光介孔材料Tb-L-MCM-41.通过核磁共振、紫外、XRD、氮吸附和荧光光谱等对配体和杂化材料的结构和性质进行了表征.结果表明,配体L很好的引入到MCM-41介孔基质中,Tb-L-MCM-41介孔材料呈现L的特征紫外吸收.同时,稀土配合物的引入占据了MCM41基质的部分孔道,使其比表面和孔体积都有所降度.Tb-L-MCM-41呈现稀土Tb3+离子的特征光.  相似文献   

6.
A novel myotoxic protein phospholipase A2 (PLA2), denoted as Gln49-PLA2, has been isolated from snake venom of Agkistrodon blomhoffii ussurensis, which has weak lethal effect and apparent anticoagulant activity, but lacks the PLA2 and hemorrhagenic activity. Gln49-PLA2 obviously increases of plasma creatine-kinase (CK) upon intramuscular injection in mice, suggesting that it may induce a dose-dependent myonecrosis. Histological studies also reveal morphological changes in mouse skeletal muscles, including extensive myonecrosis, hemorrhage and neutrophil infiltration in the treated animals. The myotoxic ability induced by Gln49-PLA2 can be partially inhibited by heparin.  相似文献   

7.
A novel myotoxic protein phospholipase A2 (PLA2), denoted as Gln49-PLA2, has been isolated from snake venom of Agkistrodon blomhoffii ussurensis, which has weak lethal effect and apparent anticoagulant activity, but lacks the PLA2 and hemorrhagenic activity. Gln49-PLA2 obviously increases of plasma creatine-kinase (CK) upon intramuscular injection in mice, suggesting that it may induce a dose-dependent myonecrosis. Histological studies also reveal morphological changes in mouse skeletal muscles, including extensive myonecrosis, hemorrhage and neutrophil infiltration in the treated animals. The myotoxic ability induced by Gln49-PLA2 can be partially inhibited by heparin.  相似文献   

8.
Ceramic coating electric-deposited by high-energy pulse   总被引:1,自引:0,他引:1  
A novel method to prepare ceramic coatings has been developed by making use of plasma energy produced from the pulsed discharge between electric conductor and aqueous electrolyte. A ZrO2-8%Y2O3, coating was obtained by this method, which had excellent adhesion with substrate, smooth surface and good resistance to high temperature oxidation.  相似文献   

9.
The transient receptor potential Ankyrin 1(TRPA1) cation channel is activated by various pungent and irritant compounds,and it also mediates the perception of noxious cold.Identification of different agonists for this channel is important for understanding its activation mechanism.Therefore,a screen for novel TRPA1 agonists was performed using an agonist-induced calcium influx assay.Out of 90 compounds screened,pinacidil was identified as a novel agonist for this channel.Pinacidil is a known opener of the K atp channel,for which it has an EC50 value of 1-3 μmol/L.In comparison,the EC50 value of pinacidil for TRPA1 is relatively high(260 μmol/L).Recombinant HEK-TRPA1 cells did not respond to P1075,another K atp channel opener,suggesting that the effect of pinacidil on TRPA1 was highly specific.Further studies revealed that the agonist activity of pinacidil could be blocked by the TRP channel inhibitors,ruthenium red and HC-030031.Using glutathione(GSH) and site-specific mutagenesis,we demonstrated that pinacidil could activate TRPA1 by covalent modification of the critical amino acids C619,C639 and C663 in the N-terminus of TRPA1.  相似文献   

10.
There is currently intense interest in the use of nanoparticles for a wide range of biomedical and technological applications. In this paper, the hierarchical Co doped ZnO nanoflowers were synthesized by a facile wet chemical method and explored as biosensing material. The as-modified novel hydrogen peroxide sensor exhibited a wide linear range(0.25–20 mM), highly reproducible response(R.S.D. of 2.7%) and long-term stability. The doping Co~(2+)ions carried out the oxidations rapidly and efficiently for the catalysis of hydrogen peroxide(H_2O_2). A high activity toward H_2O_2 in the presence of ascorbic acid(AA) and NaNO_2, which are only common for natural enzymes, has also been demonstrated. The good analytical performance, low cost and straightforward preparation method makes this doped semiconductor promising for a wide range of potential applications in medicine, biotechnology and environmental chemistry.  相似文献   

11.
唐平  余训民 《广西科学》2001,8(2):99-102
提出一个新的拓扑指数Yx,即隐氢图中的所有相邻边的一阶分子连接性指数的乘积之和占分子中有效碳原子的分率,用Yx研究取代苯,甲基苯、卤代苯、卤代烃、氯苯、含氮杂环化合物和直链伯醇的生物活(毒)性,建立相应的相关方程(r=0.9203-0.9914),计算出部分取代苯类化合物对发光菌(Photobacterium phosphoreum)、呆鲦鱼(Piumephales promelass)、大型蚤(Daphnia magua strau)、酵母菌(Saccharomyces cerevisiae)和绿藻Green algae的毒性数据,新的拓扑指数易于计算,有较高的结构区分能力,新方法计算方便,物理意义明确。  相似文献   

12.
A novel high-intensity TiO2 nanotubes array membrane was fabricated via electrochemical anodization of highly pure titanium foil and an open-ended TiO2 nanotubes array membrane was obtained by HF gas etching at the bottom of the nanotubes. Pig tubular epithelial cells (LLC-PK1) and vascular endothelial cells (ECV304) were cultivated on the open-ended TiO2 nanotubes surface through a mixing implantation method and TiO2 nanotubes biomembrane materials with physiological function were successfully produced. Hemocompatibility of glass slides, pure titanium, TiO2 nanotubes without cells and TiO2 nanotubes with culture cells were investigated by the plasma recalcification time method and reabsorption of sodium and potassium were measured by custom-designed devices. The results show that the hemocompatibility of the TiO2 nanotubes array membrane with culture cells was superior to the control group, and the biomembrane has an excellent reabsorption function. This demonstrates that a TiO2 nanotubes array membrane has excellent physiological function and is an ideal candidate material for biological dialysis.  相似文献   

13.
A novel surface technique has been developed to produce ZrO2 and ZrO2-Y2O3 coatings on the surface of alloys by using double pulsed plasma arc to react with a solution film containing nano-oxide particles. These coatings exhibit smooth surface and excellent adhesion with substrate. The morphologies of the ceramic coatings and phases were analyzed. It was shown that the oxidation resistance of 18-8 stainless steel was markedly improved by applying ZrO2 and ZrO2-Y2O3 coatings.  相似文献   

14.
Mixed-conducting oxygen permeable membranes represent a class of novel ceramic membranes, which exhibit mixed oxygen ionic and electronic conductivities. At high temperatures, oxygen can permeate through the membrane from the high to low oxygen pressure side under an oxygen concentration gradient. Theoretically, the permselectivity of oxygen is 100%. Recently, a novel mixed-conducting membrane—Ba0.5Sr0.5Co0.8Fe0.2O3−δ has been developed, which shows extremely high oxygen permeability and promising stability. Furthermore, the reactor made with such membranes was successfully applied to the partial oxidation of methane to syngas reaction using air as the oxygen source, which realized the coupling of the separation of oxygen from air and the partial oxidation of membrane reaction in one process. At 850°C, methane conversion > 88%, CO selectivity > 97% and oxygen permeation rate of about 7.8 mL/(cm2 · min) were obtained.  相似文献   

15.
Anatase TiO2 nanotubes array(ATONA) has attracted tremendous attention owing to its promising applications in solar cells, water splitting and organic pollutants photocatalytic degradation. However, the activity of ATONAs was greatly suppressed by the grain boundaries existed in the tube walls, which acted as carrier scattering and recombination centers. Herein, we report a novel strategy to prepare array of single crystalline anatase TiO2 nanotubes(SC-ATONAs) with signific...  相似文献   

16.
A new enantioselective aldol-type reaction of 4-hydroxycoumarins and ethyl trifluoropyruvate has been developed. In the presence of (DHQD)2PHAL (5 mol%), ethyl trifluoropyruvate could react with various 4-hydroxycoumarins to afford novel 4-hydroxycoumarin derivatives containing a tertiary trifluoromethyl alcohol center in good yields with moderate enantioselectivities.  相似文献   

17.
多金属氧酸盐(POMs)作为一类新颖、独特的无机构筑单元,可以通过调节合成条件使端氧或桥氧活化,从而得到多种化合物。为了研究POMs的电化学性质,选择Keggin-型磷钼酸和1,4-双(咪唑基)丁烷(L),通过水热法合成了一种新的基于多金属氧酸盐的无机-有机杂化化合物(H2L)3(PMo12O40)2,研究了该化合物对于亚硝酸盐的电催化活性。通过元素分析,红外、热重、X射线单晶衍射和X射线粉末衍射对化合物进行表征,探讨了合成过程中反应条件(例如pH值)与目标化合物结构之间的关系,测试了目标化合物的电化学性能和电催化性质。X射线单晶衍射分析表明,多酸是通过氢键与配体连接的三维结构,属于Triclinic晶系,空间群为P-1;荧光分析表明,化合物的荧光主要来自配体贡献。该化合物对亚硝酸盐有较好的电催化活性,有望用于实际样品中亚硝酸盐的检测。  相似文献   

18.
Multiwalled carbon nanotubes were oxidized with concentrated HNO3 and H2SO4 to introduce carboxylic groups onto carbon nanotubes surfaces. The oxidized carbon nanotubes were reacted subsequently with thionyl chloride and 2-Hydroxylethyl-2'-bromoisobutyrate, producing MWNT-based macroinitiators, MWNT-Br, for the atom transfer radical polymerization of (N-isopropylacrylamide). FTIR, XPS, ^1H NMR, Raman and TGA were used to characterize the resulting products and to determine the content of the water-soluble poly (N-isopropylacrylamide) chains in the product. The MWNTs grafted with PNIPAM chains have good solubility in distilled water; THF and CHCl3. TEM images of the samples provide direct evidence for the formation of a nanostructure that MWNTs coated with polymer layer. The produced MWNT-g-PNIPAM has a PNIPAM shell, which is very sensitive to the change of temperature. This method would open a door for the fabrication of novel functional carbon nanotube-based nanomaterials or nanodevices with designable structure and tailor-made properties.  相似文献   

19.
Photodegradation of organic pollutants over semiconductor catalysts is considered to be a viable method for wastewater treatment.Of the different semiconductor photocatalysts,ZnO has been widely used for the photodegradation of organic pollutants.Meanwhile,graphene is being actively investigated as a cocatalyst for such processes.The high carrier transport rate of graphene can favor the transfer of photoexcited electrons,while the increased specific surface area provides adsorption sites for the organic effluent molecules,thereby improving overall photocatalytic activity.Therefore,in this study,Pt–ZnO–reduced graphene oxide(RGO)rods with different RGO contents are synthesize during a novel Pt-induced electrochemical method,where ZnjZnO acts as the anode and PtjH2OjH2acts as the cathode.The photocatalytic degradation activity of the Pt–ZnO–RGO rods is remarkably improved under UV–visible light irradiation,with the optimum loading RGO content of 1 wt%.  相似文献   

20.
PDCD5 is a novel apoptosis-related gene. Overexpression of PDCD5 facilitates apoptosis in various tumor cells. Here, we investigated the roles of recombinant human PDCD5 (rhPDCD5) protein in chemosensitivities of hematologic malignancies. The rhPDCD5 increased the in vitro cytotoxicity of daunorubicin (DNR), adriamycin (ADM) and As203 in three hematologic tumor cell lines. In vivo studies showed that DNR combined with rhPDCD5 significantly suppressed tumor growth of U937 xenograft nude mice compared with DNR alone. In conclusion, rhPDCD5 combined with the chemotherapeutic drug has greater efficacy than chemotherapy alone, and rhPDCD5 is a very promising chemosensitizer.  相似文献   

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