scholarly journals Determination of freshness of pork by the contents of nucleic acid-related substances.

2002 ◽  
Vol 39 (3) ◽  
pp. 200-208
Author(s):  
Atsushi HORIUCHI ◽  
Mikio CHIKYU ◽  
Tatsuo KAWARASAKI ◽  
Hirohisa AKAMATSU ◽  
Seiichi SUZUKI ◽  
...  
Author(s):  
M. Boublik ◽  
V. Mandiyan ◽  
S. Tumminia ◽  
J.F. Hainfeld ◽  
J.S. Wall

Success in protein-free deposition of native nucleic acid molecules from solutions of selected ionic conditions prompted attempts for high resolution imaging of nucleic acid interactions with proteins, not attainable by conventional EM. Since the nucleic acid molecules can be visualized in the dark-field STEM mode without contrasting by heavy atoms, the established linearity between scattering cross-section and molecular weight can be applied to the determination of their molecular mass (M) linear density (M/L), mass distribution and radius of gyration (RG). Determination of these parameters promotes electron microscopic imaging of biological macromolecules by STEM to a quantitative analytical level. This technique is applied to study the mechanism of 16S rRNA folding during the assembly process of the 30S ribosomal subunit of E. coli. The sequential addition of protein S4 which binds to the 5'end of the 16S rRNA and S8 and S15 which bind to the central domain of the molecule leads to a corresponding increase of mass and increased coiling of the 16S rRNA in the core particles. This increased compactness is evident from the decrease in RG values from 114Å to 91Å (in “ribosomal” buffer consisting of 10 mM Hepes pH 7.6, 60 mM KCl, 2 m Mg(OAc)2, 1 mM DTT). The binding of S20, S17 and S7 which interact with the 5'domain, the central domain and the 3'domain, respectively, continues the trend of mass increase. However, the RG values of the core particles exhibit a reverse trend, an increase to 108Å. In addition, the binding of S7 leads to the formation of a globular mass cluster with a diameter of about 115Å and a mass of ∽300 kDa. The rest of the mass, about 330 kDa, remains loosely coiled giving the particle a “medusa-like” appearance. These results provide direct evidence that 16S RNA undergoes significant structural reorganization during the 30S subunit assembly and show that its interactions with the six primary binding proteins are not sufficient for 16S rRNA coiling into particles resembling the native 30S subunit, contrary to what has been reported in the literature.


1957 ◽  
Vol 12 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Nobuyasu KAWASAKI ◽  
Ichiro TAKI ◽  
Chiaki WATANABE ◽  
Kiyoshi MATOBA ◽  
Mokichiro NISHIO ◽  
...  

2019 ◽  
Vol 15 (5) ◽  
pp. 505-510
Author(s):  
Yanjuan Zheng ◽  
Qiushi Peng ◽  
Rui Dong ◽  
Tingyu Chen ◽  
Yi Bao ◽  
...  

Introduction: A rapid, and accurate Ultra Performance Liquid Chromatography (UPLC) method was developed to simultaneously analyze Methocarbamol, Paracetamol and the related substances Materials and Methods: Waters ACQUITY UPLC® BEH Phenyl C18 column was used in conjunction with UV detection at 225nm. Gradient elution with 0.05M, pH 6 phosphate buffer and acetonitrile flow at 0.3mL /min rate were used to separate the substances. The retention times for 4-Aminopheno, Paracetamol, Guaifenesin, Methocarbamol, and 4-Chloroacetanilide were 1.319 minute, 2.224 minute, 4.467 minute, 4.769 minute and 5.433 minute respectively. The concentration was linear in the range of 2-100 µg/ml for Methocarbamol, and 1-100 µg/mL for Paracetamol. The percentage recoveries were between 99.28±1.23% to 100.57±0.99% for Methocarbamol, and between 99.08±1.23% to 101.23±1.39% for Paracetamol. Results and Discussion: The validated optimal protocol is robust and accurate for simultaneous analysis of Methocarbamol, Paracetamol and the related substances, applicable for bulk powder as well as pharmaceutical formulation. Conclusion: In this paper, a highly sensitive, accurate, and precise UPLC method with UV-Vis detection was developed and validated for quality control of MET and PAR in bulk as well as in pharmaceutical preparations.


1965 ◽  
Vol 29 (3) ◽  
pp. 234-238
Author(s):  
Kiyoshi Nakayama ◽  
Takashi Nara ◽  
Haruo Tanaka ◽  
Zenroku Satō ◽  
Masanaru Misawa ◽  
...  

2006 ◽  
Vol 834 (1-2) ◽  
pp. 178-182 ◽  
Author(s):  
Jian Wang ◽  
Xiaojun Hu ◽  
Ying Tu ◽  
Kunyi Ni
Keyword(s):  

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