Chromatographic behavior of the biologically active proline derivative captopril on particulate, monolithic and core–shell narrow bore columns

2012 ◽  
Vol 4 (12) ◽  
pp. 4373
Author(s):  
Constantinos K. Zacharis ◽  
Theano D. Karakosta ◽  
Paraskevas D. Tzanavaras ◽  
Pantelis G. Rigas ◽  
Demetrius G. Themelis
Keyword(s):  
Biologically Active ◽  
Chromatographic Behavior ◽  
Core Shell ◽  
Narrow Bore Columns

Macrophages produce somnogenic and pyrogenic muramyl peptides during digestion of staphylococci

1991 ◽  
Vol 260 (1) ◽  
pp. R126-R133 ◽  
Author(s):  
L. Johannsen ◽  
J. Wecke ◽  
F. Obal ◽  
J. M. Krueger
Keyword(s):  
Immune Response ◽  
Body Temperature ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Mammalian Cells ◽  
Slow Wave Sleep ◽  
Biological Effects ◽  
Biologically Active ◽  
Chromatographic Behavior ◽  
Bacterial Cell Walls

Muramyl peptides have a variety of biological effects in mammals, including enhancement of the immune response, sleep, and body temperature. Although mammals lack biosynthetic pathways for muramyl peptides, they are found in mammals and are well known as components of bacterial cell walls. This suggests that phagocytic mammalian cells digest bacterial cell walls and produce biologically active muramyl peptides. Staphylococcal cell walls were radioactively labeled during growth of the bacteria. During the digestion of these radiolabeled bacteria, murine bone marrow macrophages produced low-molecular-weight substances that coeluted chromatographically with the radioactive cell wall marker. Further separation of these substances using reversed-phase high-performance liquid chromatography resulted in the isolation of substances with high specific biological activity. Intracerebroventricular injection of rabbits with these substances induced an increase in slow-wave sleep and body temperature and a suppression of rapid-eye-movement sleep. The characteristics of the biological responses and the chromatographic behavior of the active components are consistent with those of muramyl peptides. The ability of macrophages to tailor muramyl peptides from peptidoglycan may provide an amplification step for the immune response. Muramyl peptides released by macrophages may also act as mediators for various facets of the acute phase response elicited by bacterial infections such as fever and sleep.

scholarly journals Temperature Effects on Retention and Separation of PAHs in Reversed-Phase Liquid Chromatography Using Columns Packed with Fully Porous and Core-Shell Particles

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Christophe Waterlot ◽  
Anaïs Goulas
Keyword(s):  
Limit Of Detection ◽  
Tap Water ◽  
Reversed Phase ◽  
Chromatographic Behavior ◽  
Core Shell ◽  
Reversed Phase Liquid Chromatography ◽  
Porous Particles ◽  
Phase Liquid ◽  
Effects Of Temperature ◽  
Shell Particles

Effects of temperature on the reversed-phase chromatographic behavior of PAHs were investigated on three columns. The first was the recent C18column (250 mm × 4.6 mm) packed with 5 µm core-shell particles while the others were more conventional C18columns (250 mm × 4.6 mm) packed with fully porous particles. Among the 16 PAHs studied, special attention has been paid to two pairs of PAHs, fluorene/acenaphthene and chrysene/benzo[a]anthracene, which often present coeluting problems. Due to the low surface area of the core-shell particles, lowest retention time of each PAH was highlighted and effects of the temperature on the separation of PAHs were negligible in regard to those using columns packed with fully porous particles. For each PAH studied, it was demonstrated that peaks were symmetrical and may be considered as Gaussian peaks when the column packed with core-shell particle was employed. In the best condition, the separation of PAHs was conducted at 16°C under very low pressure values (670–950 psi = 46–65 bars). Depending on PAHs, the limit of detection ranged from 0.88 to 9.16 μg L−1. Analysis of spiked acetonitrile samples with PAHs at 10 and 50 µg L−1and tap water at 10 µg L−1gave very good recoveries (94%–109.3%) and high precision (1.1%–3.5%).

Core-shell based nanocarriers as delivery systems for biologically active metal ions and drugs

2008 ◽  
Vol 132 (3) ◽  
pp. e32-e33 ◽  
Author(s):  
M.A. Quadir ◽  
C. Treiber ◽  
G. Multhaup ◽  
M. Körner ◽  
R. Haag
Keyword(s):  
Metal Ions ◽  
Delivery Systems ◽  
Biologically Active ◽  
Core Shell ◽  
Active Metal

scholarly journals Green fabrication of biologically active magnetic core-shell Fe3O4/Au nanoparticles and their potential anticancer effect

2019 ◽  
Vol 96 ◽  
pp. 51-57 ◽  
Author(s):  
Zahra Izadiyan ◽  
Kamyar Shameli ◽  
Mikio Miyake ◽  
Sin-Yeang Teow ◽  
Suat-Cheng Peh ◽  
...  
Keyword(s):  
Au Nanoparticles ◽  
Magnetic Core ◽  
Biologically Active ◽  
Core Shell ◽  
Anticancer Effect
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