Conserved and Diversified Mechanism of Autophagy between Plants and Animals upon Various Stresses

Autophagy is a highly conserved degradation mechanism in eukaryotes, executing the breakdown of unwanted cell components and subsequent recycling of cellular material for stress relief through vacuole-dependence in plants and yeast while it is lysosome-dependent in animal manner. Upon stress, different types of autophagy are stimulated to operate certain biological processes by employing specific selective autophagy receptors (SARs), which hijack the cargo proteins or organelles to the autophagy machinery for subsequent destruction in the vacuole/lysosome. Despite recent advances in autophagy, the conserved and diversified mechanism of autophagy in response to various stresses between plants and animals still remain a mystery. In this review, we intend to summarize and discuss the characterization of the SARs and their corresponding processes, expectantly advancing the scope and perspective of the evolutionary fate of autophagy between plants and animals.

A Generalized Strain Energy-Based Homogenization Method for 2-D and 3-D Cellular Materials with and without Periodicity Constraints

A generalized strain energy-based homogenization method for 2-D and 3-D cellular materials with and without periodicity constraints is proposed using Hill’s Lemma and the matrix method for spatial frames. In this new approach, the equilibrium equations are enforced at all boundary and interior nodes and each interior node is allowed to translate and rotate freely, which differ from existing methods where the equilibrium conditions are imposed only at the boundary nodes. The newly formulated homogenization method can be applied to cellular materials with or without symmetry. To illustrate the new method, four examples are studied: two for a 2-D cellular material and two for a 3-D pentamode metamaterial, with and without periodic constraints in each group. For the 2-D cellular material, an asymmetric microstructure with or without periodicity constraints is analyzed, and closed-form expressions of the effective stiffness components are obtained in both cases. For the 3-D pentamode metamaterial, a primitive diamond-shaped unit cell with or without periodicity constraints is considered. In each of these 3-D cases, two different representative cells in two orientations are examined. The homogenization analysis reveals that the pentamode metamaterial exhibits the cubic symmetry based on one representative cell, with the effective Poisson’s ratio v¯ being nearly 0.5. Moreover, it is revealed that the pentamode metamaterial with the cubic symmetry can be tailored to be a rubber-like material (with v¯ ≅0.5) or an auxetic material (with v¯< 0).

Stromal-vascular fraction of adipose tissue as an alternative source of cellular material for regenerative medicine

Adipose tissue is the most convenient source of cellular material for regenerative medicine as it can be obtained in significant quantities via cosmetic liposuction, lipoaspiration of subcutaneous fat or by excision of fat deposits. Adipose tissue consists of adipocytes and cells, which are the part of the stromal-vascular fraction (SVF). Different cell populations can be isolated from SVF, among which the population of adipose tissue stem cells (adipose-derived stem cells, ADSC) is especially important for regenerative medicine. SVF can be obtained relatively easily from adipose tissue (adipose tissue is an alternative to bone marrow in terms of being a source of stem cells) and used to treat various pathologies. Recent studies show that SVF not only has a therapeutic effect similar to that of ADSC, but in some cases is even more effective. The article provides the analysis of the main methods of SVF obtainment, characteristics of SVF cellular composition, its potential for use in clinical medicine and its main advantages over other sources of cellular material, including­ ADSC cultured in vitro, for regenerative medicine. Keywords: adipocytes, adipose-derived stem cells, regenerative medicine, stromal-vascular fraction

Examination of rabbit liver by ultrasound

The article provides information on the study of the mechanical properties of isolated rabbit liver cells in terms of density, compressibility and ultra-sonic velocity. It was found that the values of the studied characteristics are mainly determined by the water content in the cells. The density, compressibility, and velocity of ultrasound in the cellular material are interconnected by a linear relationship.