Adaptation stresses

Meyerson, F.Z. (1981). Adaptation, Stress and their Prevention (In Russian). Nauka, Moscow, 200 pp. 

Wink, S., et al.. Quantitative high content imaging of cellular adaptive stress response pathways in toxicity for chemical safety assessment. Chem Res Toxicol, 2014. 27 p. 338-55. 

Up to this point, we have used a numerical input file to stress the fact that computers work on numbers, not diagrams, MM3 and TINKER work from numerical input files that are similar but not identical. Both can be adapted to wo rk u n de r th e c om m an d o f a g ra p h i c al w se r i n terface, G UI (p ro n o u n c ed g oo ey , Before going into more detail concerning MM, we shall solve a geometry optimization using the GUT of PCMODEL (Serena Sortware). The input is constructed by using a mouse to point and click on each atom of the connected atom list or skeleton of the molecule. This yields Fig. 4-6 (top). 

The upper use temperature for annealed ware is below the temperature at which the glass begins to soften and flow (about Pa-s or 10 P). The maximum use temperature of tempered ware is even lower, because of the phenomenon of stress release through viscous flow. Glass used to its extreme limit is vulnerable to thermal shock, and tests should be made before adapting final designs to any use. Table 4 Hsts the normal and extreme temperature limits for annealed and tempered glass. These data ate approximate and assume that the product is not subject to stresses from thermal shock. 

As the laminate industry grew, this anisotropic behavior was accepted and fabrication techniques adapted to it. For example, expansion and contraction space was left between wall panels, very strong adhesives were developed for bonding the product to substrates, special substrates were qualified, and where it was necessary to cut holes into the laminates the corners were radiused to prevent cracking from stress concentration. 

The design of smart materials and adaptive stmctures has required the development of constitutive equations that describe the temperature, stress, strain, and percentage of martensite volume transformation of a shape-memory alloy. These equations can be integrated with similar constitutive equations for composite materials to make possible the quantitative design of stmctures having embedded sensors and actuators for vibration control. The constitutive equations for one-dimensional systems as well as a three-dimensional representation have been developed (7). 

Stress-relaxation measurements, where stress decay is measured as a function of time at a constant strain, have also been used extensively to predict the long-term behavior of styrene-based plastics (9,12). These tests have also been adapted to measurements in aggressive environments (13). Stress-relaxation measurements are further used to obtain modulus data over a wide temperature range (14). 

Figure 4.20 Values of stress concentration factor, Kt, as a function of radius, r, with 3a limits for a circumferentially notched round bar in tension [d A/(0.5, 0.00266) inches, = 0.00333 inches] (adapted from Haugen, 1980)...

The consequence of the presence of scroll helicity in a tubule is expected to be that any increase (decrease) of the intralayer C—C distance G will increase (decrease) the local length of the spiral, but not necessarily the mean interlayer distance, since the scroll can easily adapt its radius of curvature to minimize, if necessary, any energetic strain due to a stress in the local bond lengths. 

Figure C-5 Shear Stress-Strain Curve for 3M XP251S Fiberglass-Epoxy (Adapted from [C-1])...

Discs Discs of nickel electroformed on to mandrels bearing grooves modulated with recorded sound have been used for many years for stamping sound recording discs. This process has been adapted and refined for the manufacture of digital records, including video discs . Video disc stampers must be hard, stress-free, and flat to within 0.1 m results of a short investigation directed towards these requirements have been reported ". 

The time/temperature-dependent change in mechanical properties results from stress relaxation and other viscoelastic phenomena that are typical of these plastics. When the change is an unwanted limitation it is called creep. When the change is skillfully adapted to use in the overall design, it is referred to as plastic memory. 

Antidepressant Drugs. Figure 1 Effects of stress as a model for depression and the reversal by the use of antidepressants. Multiple intracellular targets might be involved in the regulation of plasticity and resilience by antidepressants, which block extracellular transporters. Adapted from [1],... 

CRH (Corticotropin releasing hormone) is expressed in the nucleus paraventricularis of the hypothalamus and drives the stress hormone system by activating synthesis and release of corticotropin at the pituitary and in turn corticosteroid from the adrenal cortex. CRH is also expressed at many other brain locations not involved in neuroendocrine regulation, e.g. the prefrontal cortex and the amygdala. Preclinical studies have shown that CRH also coordinates the behavioral adaptation to stress (e.g. anxiety, loss of appetite, decreased sleepiness, autonomic changes, loss of libido). 

A molecular variation of plasma membrane has been reported by Puccia et al. Reduction of total lipids (XL) content and significant variations of triglyceride (TG) and phospholipids (PL) fractions were observed as a consequence of exposure of C. intestinalis ovaries to TBTCl solutions. In particular, an evident TG decrease and a PL increase were observed, which probably provoked an increment in membrane fluidity, because of the high concentration of long chain fatty acids and, as a consequence, PL. This could be a cell-adaptive standing mechanism toward the pollutants, as observed in Saccharomyces cerevisiae. Also the increase in the content of the polyunsaturated fatty acids (PUPA), important in the synthesis of compounds such as prostaglandin which are present in the ovary in a stress situation, was probably a consequence of a defense mechanism to the stress provoked by the presence of TBTCl. 

Berry, J.A. 1975 Adaptation of photosynthetic processes to stress. Science 188 644-650. 

---