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561.
562.
β-Sulfinyl α,β-unsaturated ketones (2a-f) reacted in a regioselective manner with dienes such as butadiene (3a) and 1,3-pentadiene (3b) to give 1,4-cyclohexadiene derivatives (4-8) with the concomitant elimination of sulfenic acid, while the ketones (2a-c) reacted with cyclopentadiene (3c) to yield the norbornenes (9). 相似文献
563.
The asymmetric Favorskii rearrangement of optically active α‐haloketones, which are easily prepared from chiral menthyl‐4‐toluenesulfoxide in several steps using primary or secondary amines, yields their corresponding secondary or tertiary chiral amides. The secondary chiral amides were converted to acids or amines using acylation followed by hydrolysis or reduction. In addition, the tertiary amides were directly reduced to alcohol with Super‐Hydride®. 相似文献
564.
Samira Mehravar Shohreh Fatemi Masaharu Komiyama 《Surface and interface analysis : SIA》2020,52(9):547-552
Nickel supported on reduced graphene oxide was synthesized by chemical vapor deposition technique. The crystal structure and magnetic properties of the prepared sample were studied by means of Raman spectrometry, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectrometry (ICP-OES), and vibrating sample magnetometry (VSM). The result of Raman spectroscopy revealed the structure of few-layer graphene as the support for Ni nanoparticles. XP spectrum confirmed the presence of metallic Ni on the a few-layer graphene surface. TE micrograph showed that the nickel nanoparticles were sphere shaped and the mean particle size is about 20 nm deposited on the reduced graphene oxide. The magnetic study showed the ferromagnetic behavior of 3.2 wt% nickel over reduced graphene oxide at room temperature. 相似文献
565.
Easy‐to‐Attach/Detach Solubilizing‐Tag‐Aided Chemical Synthesis of an Aggregative Capsid Protein
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Dr. Shugo Tsuda Dr. Masayoshi Mochizuki Hiroyuki Ishiba Prof. Dr. Kumiko Yoshizawa‐Kumagaye Prof. Dr. Hideki Nishio Prof. Dr. Shinya Oishi Dr. Taku Yoshiya 《Angewandte Chemie (International ed. in English)》2018,57(8):2105-2109
A solubilizing Trt‐K10 tag was developed for the effective chemical preparation of peptides/proteins with low solubility. The Trt‐K10 tag comprises a hydrophilic oligo‐Lys sequence and a trityl anchor, and can be selectively introduced to a side chain thiol of Cys of deprotected peptides/proteins with a trityl alcohol‐type introducing reagent Trt(OH)‐K10 under acidic conditions. Significantly, the ligation product in the reaction mixture of a thiol‐additive‐free native chemical ligation can be modified directly in a one‐pot manner to facilitate the isolation of the product by high‐performance liquid chromatography. Finally, the Trt‐K10 tag can be readily removed with a standard trifluoroacetic acid cocktail. Using this easy‐to‐attach/detach tag‐aided method, a hepatitis B virus capsid protein that is usually difficult to handle was synthesized successfully. 相似文献
566.
Yoshihiko Ooka Fumihiko Kanai Shinichiro Okabe Takuya Ueda Ryota Shimofusa Sadahisa Ogasawara Tetsuhiro Chiba Yasunori Sato Masaharu Yoshikawa Osamu Yokosuka 《Magnetic resonance imaging》2013
Purpose
To assess the value of gadoxetic acid-enhanced magnetic resonance imaging (MRI) for the pre-therapeutic detection of hepatocellular carcinoma (HCC) using receiver operating characteristic (ROC) analysis with the combination of computed tomography (CT) arterial portography and CT hepatic arteriography (CTAP/CTHA).Materials and Methods
A total of 54 consecutive patients with 87 nodular HCCs were retrospectively analyzed. All HCC nodules were confirmed pathologically. Three blinded readers independently reviewed 432 hepatic segments, including 78 segments with 87 HCCs. Each reader read two sets of images: Set 1, CTAP/CTHA; Set 2, gadoxetic acid-enhanced MRI including a gradient dual-echo sequence and diffusion-weighted imaging (DWI). The ROC method was used to analyze the results. The sensitivity, specificity, positive predictive value, negative predictive value and sensitivity according to tumor size were evaluated.Results
For each reader, the area under the curve was significantly higher for Set 2 than for Set 1. The mean area under the curve was also significantly greater for Set 2 than for Set 1 (area under the curve, 0.98 vs. 0.93; P = .0009). The sensitivity was significantly higher for Set 2 than for Set 1 for all three readers (P = .012, .013 and .039, respectively). The difference in the specificity, positive predictive values and negative predictive values of the two modalities for each reader was not significant (P > .05).Conclusion
Gadoxetic acid-enhanced MRI including a gradient dual-echo sequence and DWI is recommended for the pre-therapeutic evaluation of patients with HCC. 相似文献567.
F. P. Heßberger S. Antalic B. Streicher S. Hofmann D. Ackermann B. Kindler I. Kojouharov P. Kuusiniemi M. Leino B. Lommel R. Mann K. Nishio S. Saro B. Sulignano 《The European Physical Journal A - Hadrons and Nuclei》2005,26(2):233-239
The decay of odd-mass mendelevium isotopes ( A = 247-255) has been studied by means of α-γ spectroscopy. Strong evidence for a small α branch in the decay of 253Md was found. γ lines in coincidence with α-decays of 247, 249, 251, 253Md have been observed for the first time. Levels in the einsteinium daughter nuclei were assigned on the basis of α-γ coincidence
measurements. An energy systematics of the 7/2-[514] Nilsson level could be established, showing a correlation with the deformation parameter β2 of the corresponding nuclei. The results are compared with theoretical predictions 相似文献
568.
Takashi Nakajima Keishi Nishio Tadashi Ishigaki Toshio Tsuchiya 《Journal of Sol-Gel Science and Technology》2005,33(1):107-111
In this study, Lnx(SiO4)6O(1.5x–12) (Ln: Nd, La) materials as electrolytes for solid oxide fuel cells (SOFC) were prepared by the sol-gel process. It has been reported that the apatite structure of Lnx(SiO4)6O(1.5x–12) shows higher ionic conductivity than yttrium-stabilized zirconium oxide at the working temperature of the SOFC. Ln10(SiO4)6O3 is a major component of the Lnx(SiO4)6O(1.5x–12) system. Ln10(SiO4)6O3 consists of Ln9.33(SiO4)6O2 and a small amount of Ln2SiO5. It has been proposed that the ionic conductivity of Lnx(SiO4)6O(1.5x–12) decreases with increasing Ln2SiO5 with non-apatite structure. The object of the present study was to bring about this decrease by generating Ln2SiO5 in the system.Precursor solutions for synthesis of the powder were prepared using tetraethoxysilane (Si(OC2H5)4) and neodymium acetate monohydrate (Nd(CH3COO)3·H2O) or lanthanum acetate monohydrate (La (CH3COO)3·H2O) as raw materials and acetic acid (CH3COOH), 2-methoxyethanol (C2H5OCH2CH2OH), and triethanolamine (N(CH2CH2OH)3) as solvents. To obtain the powder, the solution was dried and heat-treated at 600 °C for 2 h. Disks made from the powder were heat-treated at temperatures between 1100 and 1500 °C for 10 h. The results of an XRD investigation indicate that almost all diffraction peaks of these samples could be assigned to Ln9.33(SiO4)6O2. The sample with x = 10.00 included a small amount of Ln2SiO5. The ionic conductivity of this latter sample was higher than that of other samples with similar values of x (x = 9.33 and 10.67). 相似文献
569.
Yuya Nishio Ryota Mifune Taisuke Sato Shin-ich Ishikawa Hiroshi Matsubara 《Tetrahedron letters》2017,58(12):1190-1193
A solution of hydrogen bromide (HBr) in 1,4-dioxane was prepared and investigated for its ability to brominate alcohols, and hydrobrominate alkenes. This study revealed that the brominating ability of this HBr/1,4-dioxane solution is equal or superior to that of hydrobromic acid or HBr in acetic acid. The solution of HBr in 1,4-dioxane is robust, exhibiting no decomposition of the solvent, and retaining 97% of its original concentration, when kept at ?25 °C for 30 days. This solution is a liquid alternative to HBr gas without protic solvents. 相似文献
570.
Eriko Ohgitani Masaharu Shin-Ya Masaki Ichitani Makoto Kobayashi Takanobu Takihara Masaya Kawamoto Hitoshi Kinugasa Osam Mazda 《Molecules (Basel, Switzerland)》2021,26(12)
Potential effects of tea and its constituents on SARS-CoV-2 infection were assessed in vitro. Infectivity of SARS-CoV-2 was decreased to 1/100 to undetectable levels after a treatment with black tea, green tea, roasted green tea, or oolong tea for 1 min. An addition of (−) epigallocatechin gallate (EGCG) significantly inactivated SARS-CoV-2, while the same concentration of theasinensin A (TSA) and galloylated theaflavins including theaflavin 3,3′-di-O-gallate (TFDG) had more remarkable anti-viral activities. EGCG, TSA, and TFDG at 1 mM, 40 µM, and 60 µM, respectively, which are comparable to the concentrations of these compounds in tea beverages, significantly reduced infectivity of the virus, viral RNA replication in cells, and secondary virus production from the cells. EGCG, TSA, and TFDG significantly inhibited interaction between recombinant ACE2 and RBD of S protein. These results suggest potential usefulness of tea in prevention of person-to-person transmission of the novel coronavirus. 相似文献