Review of FTIR microspectroscopy applications to investigate biochemical changes in C. elegans

Caenorhabditis elegans nematode has emerged as a model organism paving the ways for multidisciplinary research in biomedical, environmental toxicology, aging, metabolism, obesity, and drug discovery. The wide range of applications of this model organism are attributed to C. elegans’ unique features: C. elegans are inexpensive, easy to grow and maintain in a laboratory, has a short lifespan, and has a small body size. With this increased interest, the need for analytical techniques to assess the biochemical information on intact worms continues to grow. Fourier Transform Infrared (FTIR) microspectroscopy is considered as a powerful technique that can be used to determine the chemical structure and composition of various materials, including biological samples. Furthermore, the development of focal plane array detectors has made this technique attractive to study complex biological systems such as whole nematodes. This review focuses on the use of FTIR microspectroscopy to study C. elegans. The first published work on the use of FTIR microspectroscopy to study a complex whole animal was reported in 2004. Since then, very few other studies were carried out. The objective of this review is to summarize work conducted to date using FTIR microspectroscopy to study nematodes and to discuss the information that can be gained by using this technique. This could allow scientists to add this technique to the arsenal of techniques already in use for C. elegans studies.     

$\mathbb{Z}_+^k$-作用的方向原像熵

In this paper,a new type of entropy,directional preimage entropy including topological and measure theoretic versions for■-actions,is introduced.Some of their properties including relationships and the invariance are obtained.Moreover,several systems including■-actions generated by the expanding maps,■-actions defined on finite graphs and some infinite graphs with zero directional preimage branch entropy are studied.     

Raman spectroscopic of osteoporosis model in mouse tibia in vivo

In this work, we correlate Raman spectroscopy in vivo which is performed in healthy bone tibia, 3-month-old mice with osteoporotic bone, within two groups: OVX (ovariectomized) and sham (lumbar access, no ovariectomy group control). Laser beam was applied directly in a punch of skin in the distal medial part of tibia. To access bone quality, we calculate mineral/matrix ratio, relative lipid and proteoglycan content as well as the crystallinity using normalized spectrum within the integrated area method. The variables obtained for bone quality were statistically verify by ANOVA and tested for normality, where differences were considered to be significant for P < 0.05. In osteoporotic bone (OVX) we found a decreasing ratio between mineral to matrix and relative proteoglycan content, followed by a relative increasing lipid content when comparing with healthy bone (Sham) with statistical significance. The crystallinity showed higher value for OVX group but without statistical significance. Our Confocal Raman Spectroscopy provides a well-controlled environment to differentiate osteoporotic bone from healthy bone by decreasing calcium and glycosaminoglycans and increasing the amount of lipids in the cortical tibia of the mouse in vivo.