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131.
Kai‐Hsuan Hsieh Chih‐Ying Hsu I‐Ju Hung Chih‐Ling Yeh Yau‐Hung Chen Chien‐Chung Cheng 《中国化学会会志》2021,68(1):34-38
Liposomes composed of cell‐penetrating peptide derivatives increased transport across the cell membrane. Conjugating rhodamine to a cell‐penetrating peptide increased the toxicity of rhodamine in E. coli and zebrafish embryos. A similar total protein inhibition pattern with different intensities, indicating that the interaction pathways of the rho‐KTTKS‐CONH2 monomer and liposomes were the same. It suggests that the rho‐KTTKS‐CONH2 liposomes showed higher toxicity because better transport across the cell membrane increased the effective concentration inside cells. The staining of zebrafish embryos using rho‐KTTKS‐CONH2 liposomes showed a longer retention time, suggesting that it can penetrate deeper tissues or organs in zebrafish. 相似文献
132.
Fong-Fu Hsu Irfan J. Lodhi John Turk Clay F. Semenkovich 《Journal of the American Society for Mass Spectrometry》2014,25(8):1412-1420
We describe a linear ion-trap (LIT) multiple-stage (MSn) mass spectrometric approach towards differentiation of alkylacyl, alk-1-enylacyl- and diacyl-glycerophoscholines (PCs) as the [M – 15]– ions desorbed by electrospray ionization (ESI) in the negative-ion mode. The MS4 mass spectra of the [M – 15 – R2′CH = CO]– ions originated from the three PC subfamilies are readily distinguishable, resulting in unambiguous distinction of the lipid classes. This method is applied to two alkyl ether rich PC mixtures isolated from murine bone marrow neutrophils and kidney, respectively, to explore its utility in the characterization of complex PC mixture of biological origin, resulting in the realization of the detailed structures of the PC species, including various classes and many minor isobaric isomers. Graphical abstract
? 相似文献
133.
Wei-Jie Ou Chen-Shan Kao Yih-Shing Duh Jing-Ming Hsu 《Journal of Thermal Analysis and Calorimetry》2014,116(3):1111-1116
Thermal instability of lithiated cathode materials with organic carbonate were investigated using DSC. Lithium transition metal oxides of LiFePO4, LiMn2O4, and LiCoO2 were mixed with diethyl carbonate, dimethyl carbonate, ethylene carbonate, ethyl methyl carbonate, and propylene carbonate then dynamically screened to about 500 °C. Curves were acquired and analyzed to determine exothermic onset temperatures and reaction enthalpies. These data for assessing the thermal hazards of lithium-ion batteries under discharged conditions were compared to those data published in the literature. 相似文献
134.
Biosynthesis of Streptolidine Involved Two Unexpected Intermediates Produced by a Dihydroxylase and a Cyclase through Unusual Mechanisms 下载免费PDF全文
Dr. Chin‐Yuan Chang Syue‐Yi Lyu Dr. Yu‐Chen Liu Ning‐Shian Hsu Dr. Chih‐Chung Wu Dr. Cheng‐Fong Tang Kuan‐Hung Lin Dr. Jin‐Yuan Ho Dr. Chang‐Jer Wu Dr. Ming‐Daw Tsai Dr. Tsung‐Lin Li 《Angewandte Chemie (International ed. in English)》2014,53(7):1943-1948
Streptothricin‐F (STT‐F), one of the early‐discovered antibiotics, consists of three components, a β‐lysine homopolymer, an aminosugar D ‐gulosamine, and an unusual bicyclic streptolidine. The biosynthesis of streptolidine is a long‐lasting but unresolved puzzle. Herein, a combination of genetic/biochemical/structural approaches was used to unravel this problem. The STT gene cluster was first sequenced from a Streptomyces variant BCRC 12163, wherein two gene products OrfP and OrfR were characterized in vitro to be a dihydroxylase and a cyclase, respectively. Thirteen high‐resolution crystal structures for both enzymes in different reaction intermediate states were snapshotted to help elucidate their catalytic mechanisms. OrfP catalyzes an FeII‐dependent double hydroxylation reaction converting L ‐Arg into (3R,4R)‐(OH)2‐L ‐Arg via (3S)‐OH‐L ‐Arg, while OrfR catalyzes an unusual PLP‐dependent elimination/addition reaction cyclizing (3R,4R)‐(OH)2‐L ‐Arg to the six‐membered (4R)‐OH‐capreomycidine. The biosynthetic mystery finally comes to light as the latter product was incorporation into STT‐F by a feeding experiment. 相似文献
135.
M. Sc. Shih‐Fan Hsu Dipl.‐Chem. Susanne Rommel M. Sc. Philipp Eversfield Dr. Keven Muller Prof. Dr. Elias Klemm Prof. Dr. Werner R. Thiel Prof. Dr. Bernd Plietker 《Angewandte Chemie (International ed. in English)》2014,53(27):7074-7078
Apart from energy generation, the storage and liberation of energy are among the major problems in establishing a sustainable energy supply chain. Herein we report the development of a rechargeable H2 battery which is based on the principle of the Ru‐catalyzed hydrogenation of CO2 to formic acid (charging process) and the Ru‐catalyzed decomposition of formic acid to CO2 and H2 (discharging process). Both processes are driven by the same catalyst at elevated temperature either under pressure (charging process) or pressure‐free conditions (discharging process). Up to five charging–discharging cycles were performed without decrease of storage capacity. The resulting CO2/H2 mixture is free of CO and can be employed directly in fuel‐cell technology. 相似文献
136.
Selective Transfer Hydrogenation and Hydrogenation of Ketones Using a Defined Monofunctional (P^N(Bn)^N(Bn)^P)–RuII Complex 下载免费PDF全文
Shih‐Fan Hsu Prof. Dr. Bernd Plietker 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(15):4242-4245
A defined (P^N^N^P)–Ru complex possessing tertiary amines within the ligand backbone proved to be highly active both in transfer hydrogenations and hydrogenations of a variety of ketones. As compared to the existing catalytic systems, no bifunctional activation of H2 or of the substrate by the metal center and a secondary amine within the ligand backbone is required to obtain high activities at catalyst loadings of down to 10 ppm. 相似文献
137.
Dr. Cheng‐Chung Lee Dr. Manuel Maestre‐Reyna Dr. Kai‐Cheng Hsu Prof. Dr. Hao‐Ching Wang Prof. Dr. Chia‐I Liu Prof. Dr. Wen‐Yih Jeng Li‐Ling Lin Richard Wood Dr. Chia‐Cheng Chou Prof. Dr. Jinn‐Moon Yang Prof. Dr. Andrew H.‐J. Wang 《Angewandte Chemie (International ed. in English)》2014,53(48):13054-13058
Crown ethers are small, cyclic polyethers that have found wide‐spread use in phase‐transfer catalysis and, to a certain degree, in protein chemistry. Crown ethers readily bind metallic and organic cations, including positively charged amino acid side chains. We elucidated the crystal structures of several protein‐crown ether co‐crystals grown in the presence of 18‐crown‐6. We then employed biophysical methods and molecular dynamics simulations to compare these complexes with the corresponding apoproteins and with similar complexes with ring‐shaped low‐molecular‐weight polyethylene glycols. Our studies show that crown ethers can modify protein surface behavior dramatically by stabilizing either intra‐ or intermolecular interactions. Consequently, we propose that crown ethers can be used to modulate a wide variety of protein surface behaviors, such as oligomerization, domain–domain interactions, stabilization in organic solvents, and crystallization. 相似文献
138.
Sin-Hong Chen Ya-Chi Lin Ming-Kuei Shih Li-Fei Wang Shyh-Shyan Liu Jue-Liang Hsu 《Molecules (Basel, Switzerland)》2020,25(22)
Protein phosphorylation is a crucial post-translational modification that plays an important role in the regulation of cellular signaling processes. Site-specific quantitation of phosphorylation levels can help decipher the physiological functions of phosphorylation modifications under diverse physiological statuses. However, quantitative analysis of protein phosphorylation degrees is still a challenging task due to its dynamic nature and the lack of an internal standard simultaneously available for the samples differently prepared for various phosphorylation extents. In this study, stable-isotope dimethyl labeling coupled with phosphatase dephosphorylation (DM + deP) was tried to determine the site-specific degrees of phosphorylation in proteins. Firstly, quantitation accuracy of the (DM + deP) approach was confirmed using synthetic peptides of various simulated phosphorylation degrees. Afterwards, it was applied to evaluate the phosphorylation stoichiometry of milk caseins. The phosphorylation degree of Ser130 on α-S1-casein was also validated by absolute quantification with the corresponding synthetic phosphorylated and nonphosphorylated peptides under a selected reaction monitoring (SRM) mode. Moreover, this (DM + deP) method was used to detect the phosphorylation degree change of Ser82 on the Hsp27 protein of HepG2 cells caused by tert-butyl hydroperoxide (t-BHP) treatment. The results showed that the absolute phosphorylation degree obtained from the (DM + deP) approach was comparable with the relative quantitation resulting from stable-isotope dimethyl labeling coupled with TiO2 enrichment. This study suggested that the (DM + deP) approach is promising for absolute quantification of site-specific degrees of phosphorylation in proteins, and it may provide more convincing information than the relative quantification method. 相似文献
139.
S. K. Liaw S. Wang C. S. Shin N. K. Chen K. C. Hsu A. Manshina Y. Tver’yanovich C.-F. Su L. K. Wang 《Laser Physics》2010,20(7):1608-1611
A single-longitudinal-mode selection is realized in a linear-cavity fiber laser construction using a loop-back optical circulator
and a partial reflectance fiber Bragg grating as the cavity ends. At 1551 nm wavelength, the measured signal-to-noise-ratio
is 56 dB and with a line width less than 1 MHz obtained using multiple subring cavities as mode filters. The pumping efficiency
is 10% improved by recycling the residual pump power to gain medium. 相似文献
140.
The adhesion behavior of di-n-butyl phthalate (DBP) onto different substrates (quartz, glass, and silicon) used as wafer surfaces was studied by using an in situ UV spectrophotometric technique. The results from the closed cell experiments revealed that greatest extent of DBP adhesion occurred on the quartz chip (0.154 μg cm−2), followed in the order by the glass (0.054 μg cm−2) and silicon (0.039 μg cm−2). By means of the in situ spectrophotometric observation, application of an electrical field at 290 V cm−1 in the cell proved to be effective in inducing charging of DBP aerosols, which were consequently attracted towards the electrodes. This method can be applied to wafer storage and transport equipments to prevent wafer contamination from material outgassing representative by DBP. 相似文献