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排序方式: 共有613条查询结果,搜索用时 15 毫秒
31.
Tsai CC Mikes P Andrukh T White E Monaenkova D Burtovyy O Burtovyy R Rubin B Lukas D Luzinov I Owens JR Kornev KG 《Nanoscale》2011,3(11):4685-4695
We describe a method of fabrication of nanoporous flexible probes which work as artificial proboscises. The challenge of making probes with fast absorption rates and good retention capacity was addressed theoretically and experimentally. This work shows that the probe should possess two levels of pore hierarchy: nanopores are needed to enhance the capillary action and micrometer pores are required to speed up fluid transport. The model of controlled fluid absorption was verified in experiments. We also demonstrated that the artificial proboscises can be remotely controlled by electric or magnetic fields. Using an artificial proboscis, one can approach a drop of hazardous liquid, absorb it and safely deliver it to an analytical device. With these materials, the paradigm of a stationary microfluidic platform can be shifted to the flexible structures that would allow one to pack multiple microfluidic sensors into a single fiber. 相似文献
32.
We report on the fabrication of a novel material with the ability to remain in solution even under the very demanding conditions required for structural and dynamic characterization of biomacromolecule assays. This stability is provided by the increase in surface area of a low density material (aluminium) natively coated with a very hydrophilic surface composed of aluminium oxide (Al(2)O(3)) and metallic silver nanoparticles. Additionally, due to the dense collection of active hot spots on their surface, this material offers higher levels of SERS intensity as compared with the same free and aggregated silver nanoparticles. 相似文献
33.
A. L. Lapidus A. Yu. Krylova Ya. V. Mikhailova L. V. Sineva A. B. Erofeev 《Solid Fuel Chemistry》2011,45(2):71-80
The effect of the nature of the support of a Co catalyst on the synthesis of hydrocarbons from CO, H2, and C2H4 was studied in this work. It was found that the introduction of ethylene into synthesis gas resulted in an increase in the yield of liquid hydrocarbons. In this case, the conversion of C2H4 was complete and the degree of its involvement into the synthesis of C5+ hydrocarbons depended on the concentration of this component in the starting mixture and the nature of the support. Specific features of the adsorption of CO and C2H4 on the used Co catalysts were determined using a temperature-programmed desorption method. 相似文献
34.
Marina A. Marchenko Victoria V. Nefedova Daria S. Yampolskaya Galina V. Kopylova Daniil V. Shchepkin Sergey Y. Bershitsky Natalia A. Koubassova Andrey K. Tsaturyan Dmitrii I. Levitsky Alexander M. Matyushenko 《International journal of molecular sciences》2020,21(22)
Tropomyosin (Tpm) is one of the major actin-binding proteins that play a crucial role in the regulation of muscle contraction. The flexibility of the Tpm molecule is believed to be vital for its functioning, although its role and significance are under discussion. We choose two sites of the Tpm molecule that presumably have high flexibility and stabilized them with the A134L or E218L substitutions. Applying differential scanning calorimetry (DSC), molecular dynamics (MD), co-sedimentation, trypsin digestion, and in vitro motility assay, we characterized the properties of Tpm molecules with these substitutions. The A134L mutation prevented proteolysis of Tpm molecule by trypsin, and both substitutions increased the thermal stability of Tpm and its bending stiffness estimated from MD simulation. None of these mutations affected the primary binding of Tpm to F-actin; still, both of them increased the thermal stability of the actin-Tpm complex and maximal sliding velocity of regulated thin filaments in vitro at a saturating Ca2+ concentration. However, the mutations differently affected the Ca2+ sensitivity of the sliding velocity and pulling force produced by myosin heads. The data suggest that both regions of instability are essential for correct regulation and fine-tuning of Ca2+-dependent interaction of myosin heads with F-actin. 相似文献
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38.
A. G. Popov A. V. Shitov E. G. Gerasimov D. Yu. Vasilenko M. Yu. Govorkov D. Yu. Bratushev V. P. Vyatkin K. Yu. Shunyaev T. L. Mikhailova 《The Physics of Metals and Metallography》2012,113(4):331-340
Pressless process used for the preparation of sintered Nd-Fe-B magnets has been studied. The effect of the average particle
size D
av, filling density ρf, and powder-texturing conditions for obtaining density ρ and desired magnetic hysteretic properties of sintered magnets has
been investigated for both traditional technology (TT) and low-oxygen technology (LOT). The ρf magnitude ensuring the optimum relation between the density ρ of sintered magnets and their degree of texture was shown to
be 2.5–3.0 and 2.2 g/cm3 for the TT and LOT, respectively. At lower ρf magnitudes, no required density of sintered magnets is reached, whereas at higher filling densities, a low level of texture
and low remanence are realized. Optimum parameters of pulsed field inducing the high degree of texture in powders have been
determined. The following properties were achieved for magnets prepared by pressless LOT: B
r
≥ 14.2 kG, H
c ≥ 8 kOe, and (BH)max ≥ 47.9 MG Oe. 相似文献
39.
The effect of the hydrogen regeneration conditions of a 20% Co/Hβ cobalt-zeolite catalyst on its properties in the synthesis of hydrocarbons from CO and H2 was studied. It was found that regeneration with hydrogen was most effective at 400°C. In this case, the productivity of the catalyst was as high as 305 × 103 g/m3 Cat/h at a maximum synthesis-gas space velocity (5000 h−1). 相似文献
40.
Olga V. Kovaleva Madina A. Rashidova Daria V. Samoilova Polina A. Podlesnaya Rasul M. Tabiev Valeria V. Mochalnikova Alexei Gratchev 《International journal of molecular sciences》2021,22(1)
There is an urgent need for identification of new prognostic markers and therapeutic targets for non-small cell lung cancer (NSCLC). In this study, we evaluated immune cells markers in 100 NSCLC specimens. Immunohistochemical analysis revealed no prognostic value for the markers studied, except CD163 and CD206. At the same time, macrophage markers iNOS and CHID1 were found to be expressed in tumor cells and associated with prognosis. We showed that high iNOS expression is a marker of favorable prognosis for squamous cell lung carcinoma (SCC), and NSCLC in general. Similarly, high CHID1 expression is a marker of good prognosis in adenocarcinoma and in NSCLC in general. Analysis of prognostic significance of a high CHID1/iNOS expression combination showed favorable prognosis with 20 months overall survival of patients from the low CHID1/iNOS expression group. For the first time, we demonstrated that CHID1 can be expressed by NSCLC cells and its high expression is a marker of good prognosis for adenocarcinoma and NSCLC in general. At the same time, high expression of iNOS in tumor cells is a marker of good prognosis in SCC. When used in combination, CHID1 and iNOS show a very good prognostic capacity for NSCLC. We suggest that in the case of lung cancer, tumor-associated macrophages are likely ineffective as a therapeutic target. At the same time, macrophage markers expressed by tumor cells may be considered as targets for anti-tumor therapy or, as in the case of CHID1, as potential anti-tumor agents. 相似文献