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951.
Le Duc Anh Shingo Kaneta Masashi Tokunaga Munetoshi Seki Hitoshi Tabata Masaaki Tanaka Shinobu Ohya 《Advanced materials (Deerfield Beach, Fla.)》2020,32(14):1906003
Strontium titanate (SrTiO3 or STO) is important for oxide-based electronics as it serves as a standard substrate for a wide range of high-temperature superconducting cuprates, colossal magnetoresistive manganites, and multiferroics. Moreover, in its heterostructures with different materials, STO exhibits a broad spectrum of important physics such as superconductivity, magnetism, the quantum Hall effect, giant thermoelectric effect, and colossal ionic conductivity, most of which emerge in a two-dimensional (2D) electron gas (2DEG) formed at an STO interface. However, little is known about its counterpart system, a 2D hole gas (2DHG) at the STO interface. Here, a simple way of realizing a 2DHG with an ultrahigh mobility of 24 000 cm2 V−1 s−1 is demonstrated using an interface between STO and a thin amorphous FeOy layer, made by depositing a sub-nanometer-thick Fe layer on an STO substrate at room temperature. This mobility is the highest among those reported for holes in oxides. The carrier type can be switched from p-type (2DHG) to n-type (2DEG) by controlling the Fe thickness. This unprecedented method of forming a 2DHG at an STO interface provides a pathway to unexplored hole-related physics in this system and enables extremely low-cost and high-speed oxide electronics. 相似文献
952.
Marivane Turim Koschevic Renata Pires de Araújo Vitor Augusto dos Santos Garcia Farayde Matta Fakhouri Kelly Mari Pires de Oliveira Eduardo José Arruda Alain Dufresne Sílvia Maria Martelli 《应用聚合物科学杂志》2021,138(35):50885
Typha domingensis (Cattail) fiber is a significant natural resource, abundant in cellulose. The study reports the useful utilization of T. domingensis fiber for physicochemical impregnation of silver nanoparticles and benzalkonium chloride, in the development of a material with antimicrobial activity. The fibers were pre-treated with alkaline hydrogen peroxide (bleaching) for partial removal of lignin, pectin and waxes. Subsequently treated in a solution of different concentrations of benzalkonium chloride and Tollens' reagent. The new materials obtained were carefully investigated for their structure and thermal stability, morphology and susceptibility to antimicrobials (Staphylococcus aureus, Escherichia coli, Salmonella typhimuruim, and Salmonella enteritidis). Fourier transform infrared spectra showed the presence of benzalkonium chloride. The morphology analysis showed the silver nanoparticles on the surface of the bleached fibers. The susceptibility profile to antimicrobials was confirmed by the formation of inhibition halos (≅11.26 mm). Based on the properties of the materials obtained, it can be concluded that the modified cattail fibers have the potential to be used as a functional filler, or coating, in the development of antimicrobial composites. 相似文献
953.
Dr. Michael Kugler Dr. Jan Nekvinda Dr. Josef Holub Dr. Suzan El Anwar Dr. Viswanath Das Dr. Václav Šícha Dr. Klára Pospíšilová Dr. Milan Fábry Dr. Vlastimil Král Dr. Jiří Brynda Dr. Václav Kašička Dr. Marián Hajdúch Dr. Pavlína Řezáčová Dr. Bohumír Grüner 《Chembiochem : a European journal of chemical biology》2021,22(18):2741-2761
This review describes recent progress in the design and development of inhibitors of human carbonic anhydrase IX (CA IX) based on space-filling carborane and cobalt bis(dicarbollide) clusters. CA IX enzyme is known to play a crucial role in cancer cell proliferation and metastases. The new class of potent and selective CA IX inhibitors combines the structural motif of a bulky inorganic cluster with an alkylsulfamido or alkylsulfonamido anchor group for Zn2+ ion in the enzyme active site. Detailed structure-activity relationship (SAR) studies of a large series containing 50 compounds uncovered structural features of the cluster-containing inhibitors that are important for efficient and selective inhibition of CA IX activity. Preclinical evaluation of selected compounds revealed low toxicity, favorable pharmacokinetics and ability to reduce tumor growth. Cluster-containing inhibitors of CA IX can thus be considered as promising candidates for drug development and/or for combination therapy in boron neutron capture therapy (BNCT). 相似文献
954.
955.
Suffusion is a type of internal erosion, namely, the transportation of soil driven by the seepage force of finer fractions within coarser fractions. The present work uses triaxial confining compression tests to study how a small degree of suffusion affects soil stiffness and deformation. This approach allows the suffusion inside a specimen to impose a downward seepage flow. Although a small degree of suffusion is not detectable, it can lead to the deterioration of earth structures. Linear displacement transducers and clip gages were attached to specimens to accurately measure the localized strain rates. In addition, the turbidity of the discharged water was evaluated. Following the downward seepage, each drained specimen was monotonically compressed. The experimental results show that cohesive soil undergoes suffusion and that most of the clay fractions bonding the sand particles erode. At intermediate strain, the deviator stress decreases in proportion to the degree of suffusion, but this decrease ceases at the critical state. Anisotropic behavior is observed and is tentatively attributed to the disruption of the soil texture, which is qualitatively monitored by scanning electron microscopy. Finally, a simple formula is proposed for evaluating the decrease in stiffness due to suffusion. 相似文献
956.
Paolino Ninfali Michele Mari Maria A. Meli Carla Roselli Elena Antonini 《International Journal of Food Science & Technology》2019,54(5):1558-1565
This study evaluated the effects of malting and in vitro digestion on the bioaccessibility of six avenanthramides (AVNs), soluble phenols (SPs) and antioxidant capacity (ORAC) in cookies (3B, 4B, 5B) prepared with oat flour malted for three (M3), four (M4), five (M5) days, respectively. Control cookies (CTRL) were made with non-malted oat flour (M0). Five-days malting increased the AVN content of native kernels up to 10-folds, whereas SPs and ORAC tripled their values. After the in vitro digestion, AVNs showed their bioaccessibility in the following order: 5B > 4B > 3B, with a recovery of 1703 μg AVNs per 50 g portion of 5B cookies, compared to 135 μg of CTRL. Results showed that the inclusion of 27% malted oat flour was effective to formulate functional cookies with satisfactory technological properties, high AVN content and bioaccessibility. 相似文献
957.
D Rebouillat A Hovnanian I Marié AG Hovanessian 《Canadian Metallurgical Quarterly》1999,274(3):1557-1565
The 2-5A synthetases represent a family of proteins implicated in the mechanism of the antiviral action of interferon. When activated by double-stranded RNA, these proteins polymerize ATP into 2'-5'-linked oligomers with the general formula pppA(2'p5'A)n, n >/= 1. Three forms of human 2-5A synthetases have been described corresponding to proteins of 40/46 (p40/p46), 69/71 (p69/p71), and 100 kDa (p100). Here we describe the molecular cloning and characterization of p100. By screening a cDNA expression library with a specific p100 polyclonal antibody, we first isolated a 590-nucleotide cDNA fragment which was subsequently used to isolate the full-length 6365-nucleotide cDNA. This cDNA recognizes a distinct interferon-induced messenger RNA of 7 kilobases. It has an open reading frame encoding a protein of 1087 amino acids including the sequence of seven peptides obtained by microsequencing of the natural p100 protein, which was purified from interferon-treated human cells. p100 is composed of three adjacent domains, each homologous to the previously defined catalytic unit of 350 amino acids, which is present as one unit in p40/p46 and as two units in p69/p71. The recombinant p100 synthesized preferentially dimeric 2', 5'-oligoadenylate molecules and displayed parameters for maximum enzyme activity similar to the natural p100. These results confirm that the enzymatic activity of p100 is distinct compared with that of p40/p46 and p69/p71. 相似文献
958.
An analytical model, known as RISK-N, is developed to simulate nitrogen cycling in soils, and nitrate transport and fate in soils and ground water. The soil is separated into upper-root, lower-root, and intermediate-vadose zones, each with uniform properties. Transport in each soil zone is modeled on the basis of complete mixing. Transport in the aquifer, however, is modeled using a two-dimensional advection-dispersion transport equation. A simulation is made with a hypothetical corn plot, using meteorological, soil, hydrologic, and hydrogeological data for the South Platte River region of northeastern Colorado. Sensitivity analyses are performed on model parameters. This study shows that the RISK-N model is capable of simulating nitrate leaching rates, as well as ground-water concentrations, that are consistent with those obtained by numerical models, while requiring fewer input variables. 相似文献
959.
The inhibitory effect of a protein isolated from rat serum on lysosomal acid cholesteryl ester hydrolase (acid CEH; EC.3.1.1.13)
activity was studied. An inhibitor was purified from rat serum following ultracentrifugation and heat treatment using column
chromatography on Sephacryl S-200 and ultrafiltration. The purified inhibitor appeared as a single protein band in sodium
dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The molecular weight of the inhibitor was 28,000 Daltons as judged
by gel filtration on Sephacryl S-200 and SDS-polyacrylamide gel electrophoresis. The purified inhibitor was shown to be apolipoprotein
A-I (apo A-I), the major apolipoprotein of high-density lipoprotein (HDL), using immunoprecipitation with rat anti-apo A-I
immunoglobulin (Ig)G. Inhibition of acid CEH activity by apo A-I was dependent on the concentration of apo A-I. The values
of Vmax obtained were similar with or without apo A-I. Apo A-I of various other mammalian species, including human, bovine and rabbit,
also inhibited acid CEH activity. Other apolipoproteins, such as apo A-II and apo B, also showed inhibiting activity. On the
other hand, apo A-I had no effect on the activity of other enzymes found in lysosomes, such as cathepsin D, β-glucuronidase
and acid phosphatase. The results suggest that apolipoproteins may play a role in the regulation of hydrolysis of cholesteryl
esters in lipoproteins, that have been transferred to the liver, and that the inhibition of acid CEH activity by apo A-I may
be a characteristic of the lipid-binding protein or be due to changes of the lipid/water interface. 相似文献
960.
Maija Hoikkanen Mari Honkanen Minnamari Vippola Toivo Lepistö Jyrki Vuorinen 《Progress in Organic Coatings》2011,72(4):716-723
Enhancing adhesion is of primary importance in preparation of insert injection molded plastic–metal hybrids. Here, the combination of coupling agent application parameters and steel oxide microstructure effects on the adhesion in thermoplastic urethane–stainless steel hybrids was studied. The stainless steel oxide structure was first modified by electrolytical polishing and subsequent oxidation treatment, then the steel was coated with N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (γ-AEAPS) prior to overmolding with thermoplastic urethane. The properties of formed silane coatings and ultimately the thermoplastic urethane–stainless steel hybrids were determined by several microscopical methods, infrared spectroscopy and mechanical testing. The bond strength of hybrids depended on the silane layer thickness. Also the stainless steel surface oxide structure had a remarkable influence on the coating formation and the resulting hybrid bond strength. 相似文献