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91.
张德礼 《中国科学B辑(英文版)》1991,(8)
In this paper, superhigh reproductive rate strains of MEV with titre more than HA8192* or TCID50 log9.7 10 have been achieved both by cultivation in cell lines with different susceptibility to MEV and by isolating and identifying in field by the author. The systematic tests proved that S18 and L12 strains of MEV are the best strains for vaccine preparation. In this study, the best means for the tissue cultivation of MEV and the most advanced technological process for the production and detection of serum-free cell-cultured MEV fluids with super-high HA titre in batches in large quantities have been established for the first time. Optimum conditions for MEV inactivation were determined, and safe and effective inactivated vaccines with mineral oil or A1(OH)3 gel adjuvant were successfully prepared with serum-free cell-cultured MEV fluids. Both vaccines with different adjuvants can be manufactured in batches in large quantities and have been widely used all over China since 1986. The change laws of the imm 相似文献
92.
Xiang Hao Kaixiang Yang Hairong Wang Feng Peng Haiyang Yang 《Angewandte Chemie (International ed. in English)》2020,59(11):4314-4319
Non‐Newtonian fluids are ubiquitous in daily life and industrial applications. Herein, we report an intelligent fluidic system integrating two distinct non‐Newtonian rheological properties mediated by an autocatalytic enzyme reaction. Associative polyelectrolytes bearing a small amount of ionic and alkyl groups are engineered: by carefully balancing the charge density and the hydrophobic effect, the polymer solutions demonstrate a unique shear thickening property at low pH while shear thinning at high pH. The urea‐urease clock reaction is utilized to program a feedback‐induced pH change, leading to a strong upturn of the nonlinear viscoelastic properties. As long as the chemical fuel is supplied, two distinct non‐Newtonian states can be achieved with a tunable lifetime span. As a proof of concept, we demonstrate how the physical energy‐driven nonequilibrium properties can be manipulated by a chemical‐fueled process. 相似文献
93.
Zexi Liu Jing Ai Prashant Kumar Enming You Xiong Zhou Xi Liu Zhongqun Tian Petr Bou Yingying Duan Lu Han Nicholas A. Kotov Songyuan Ding Shunai Che 《Angewandte Chemie (International ed. in English)》2020,59(35):15226-15231
A surface‐enhanced Raman scattering‐chiral anisotropy (SERS‐ChA) effect is reported that combines chiral discrimination and surface Raman scattering enhancement on chiral nanostructured Au films (CNAFs) equipped in the normal Raman scattering Spectrometer. The CNAFs provided remarkably higher enhancement factors of Raman scattering (EFs) for particular enantiomers, and the SERS intensity was proportional to the enantiomeric excesses (ee) values. Except for molecules with mesomeric species, all of the tested enantiomers exhibited high SERS‐ChA asymmetry factors (g), ranging between 1.34 and 1.99 regardless of polarities, sizes, chromophores, concentrations and ee. The effect might be attributed to selective resonance coupling between the induced electric and magnetic dipoles associated with enantiomers and chiral plasmonic modes of CNAFs. 相似文献
94.
Kun‐ze Du Jin Li Lanhui Wang Jia Hao Xue‐jing Yang Xiu‐mei Gao Yan‐xu Chang 《Journal of separation science》2020,43(4):799-807
Hydrosoluble trehalose lipid (a biosurfactant) was employed for the first time as a green extraction solution to extract the main antioxidant compounds (geniposidic acid, chlorogenic acid, caffeic acid, and rutin) from functional plant tea (Eucommia ulmoides leaves). Single‐factor tests and response surface methodology were employed to optimize the extraction conditions for ultrasound‐assisted micellar extraction combined with ultra‐high‐performance liquid chromatography in succession. A Box‐Behnken design (three‐level, three‐factorial) was used to determine the effects of extraction solvent concentration (1–5 mg/mL), extraction solvent volume (5–15 mL), and extraction time (20–40 min) at a uniform ultrasonic power and temperature. In consequence, the best analyte extraction yields could be attained when the trehalose lipid solution concentration was prepared at 3 mg/mL, the trehalose lipid solution volume was 10 mL and the extraction time was set to 35 min. In addition, the recoveries of the antioxidants from Eucommia ulmoides leaves analyzed by this analytical method ranged from 98.2 to 102%. These results indicated that biosurfactant‐enhanced ultrasound‐assisted micellar extraction coupled with a simple ultra‐high‐performance liquid chromatography method could be effectively applied in the extraction and analysis of antioxidants from Eucommia ulmoides leaf samples. 相似文献
95.
Flat sheet asymmetric membranes were fabricated with homogeneous solution of poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) using N-methyl-2-pyrrolidone (NMP) as solvent via phase inversion method. PEGME (Poly ethylene glycol methyl ether) (Mn 5000) blend Humic Acid (HA), of different mole ratio was used as additive. Characterization of the membranes was done by Field emission scanning electron microscope (FESEM), Fourier Transform Infrared (FTIR) spectroscopy, Atomic force microscopy (AFM) and Differential scanning calorimetry (DSC) studies. Liquid-liquid displacement porosimetry (LLDP) study evaluated the morphological parameters, average pore size and pore size distribution. Bovine serum albumin (BSA) (MW - 68,000 Da) was used to study the antifouling effect and pore blocking mechanism of the membranes. The pure water flux (PWF), solute rejection and flux recovery ratio drastically increases for the PEGME blended HA membranes whereas the water contact angle decreases significantly. The pH responsiveness character of the prepared membranes altered the hydraulic permeability and rejection % at different pH. Finally, optimization of the variables contributing towards the PWF and BSA rejection of the desired membrane was performed using Design expert software 9.0 TRIAL through ANOVA (analysis of variance) using the combination of response surface methodology (RSM) and central composite design (CCD). 相似文献
96.
以碳酸锶为甲烷吸附活化的模型催化剂,用切换变应答、CH4(CO2)-TPD等技术,对甲烷的吸附、碱性对催化剂性能的影响进行了研究,结果表明,甲烷在碳酸锶上的活化显示出明显的酸碱活化机理特征,瞬变应答及TPD结果均证明,甲烷在碳酸锶表面有较强的吸附,其脱附温度约310℃,关联结果表明,甲烷转化率及C2烃收率与催化剂表面SrO碱性中心浓度有非常一致的顺变关系,因此催化剂表面的酸碱中心可能是甲烷的选择活 相似文献
97.
Jimena Scoccia M. Julia Castro M. Belén Faraoni Cecilia Bouzat Víctor S. Martín Darío C. Gerbino 《Tetrahedron》2017,73(20):2913-2922
A novel and efficient synthesis of dibenzo[b,e]oxepin-11(6H)-ones by direct intramolecular ortho-acylation from readily available 2-(phenoxymethyl)benzoic acids was developed. The method takes advantage of a newly developed cooperative system consisting of sustainable FeCl2 and Cl2CHOCH3 as the key components. This methodology is compatible with a wide variety of functional groups in good to excellent yields and high regioselectivity. The synthetic application of new protocol was extended to the synthesis of known tricyclic drug doxepin as well as a small library of oxepin based derivatives. For the first time, the obtained dibenzo[b,e]oxepinone derivatives were evaluated for their biological activities on the free-living nematode Caenorhabditis elegans as an effective and cost-efficient model system for anthelmintic discovery. 相似文献
98.
99.
The purpose of this investigation was to study the effect of Streptomyces erumpens cells immobilized in various matrices, i.e., agar–agar, polyacrylamide, and luffa (Luffa cylindrica L.) sponge for production of α-amylase. Luffa sponge was found to be 21% and 51% more effective in enzyme yield than agar–agar
and polyacrylamide, respectively. Response surface methodology was used to evaluate the effect of three main variables, i.e.,
incubation period, pH, and temperature on enzyme production with immobilized luffa cells. The experimental results showed
that the optimum incubation period, pH, and temperature were 36h, 6.0, and 50 °C, respectively. The repeated batch fermentation
of immobilized cells in shake flasks showed that S. erumpens cells were more or less equally physiologically active on the support even after three cycles of fermentation (3,830–3,575
units). The application of S. erumpens crude enzyme in liquefying cassava starch was studied. The maximum hydrolysis of cassava starch (85%) was obtained with the
application of 4ml (15,200 units) of crude enzyme after 5 h of incubation. 相似文献
100.
《Analytical letters》2012,45(15):2411-2429
Abstract A nickel(II) [Ni(II)] ion-selective electrode was prepared by incorporating a new N-S Schiff base ligand, glyoxal-bis(S-benzyldithiocarbazate) (GBSB), as a neutral carrier into the PVC matrix. The proposed electrode exhibits an excellent near-Nernstian response for Ni2+ ions, ranging from 2.8 × 10?7 to 1.0 × 10?1 mol/L with a detection limit of 1.2 × 10?7 mol/L and a slope of 31.9 ± 0.3 mV/dec in pH 4.0 nitrate buffer solution at 25°C. It has an appropriate response time and suitable reproducibility and can be used for at least 3 months. The operational pH range of the proposed electrode is 4.0–7.5. The response mechanism is discussed in view of the alternating current (AC) impedance technique. In addition, the electrode was successfully used as an indicator electrode in potentiometric titration of Ni2+ ion and in the direct determination of Ni2+ ion in milk power and chocolate samples. 相似文献