Nevertheless, these procedures are illustrations of tests that can be used to screen patients to find out the ones who have a propensity for ventricular tachyarrhythmia, and thus may be at increased risk of sudden cardiac death. Depending upon the biochemical markers of interest, measurements of mass, concentration or abundance may be less important than determination of whether the marker is present or absent. The invention encompasses embodiments in which measurement of a biochemical marker in a patient includes determining whether the marker is present or not.
More on Molecular Manufacturing Mechanics Chris Phoenix, Director of Research, Center for Responsible Nanotechnology In the last science essay, I promised to provide additional detail on several topics that were beyond the scope of that essay.
Why will a well-designed molecular machine system not suffer wear? How can contaminant molecules be excluded from a manufacturing system? Mechanically guided reactions are very different, in several important ways, from familiar chemical reactions.
Pressure can be two orders of magnitude higher; concentration, seven orders of magnitude higher. The position and orientation of the reactant molecules can be controlled, as well as the direction of forces. Molecular fragments that would be far too reactive to survive long in any other form of chemistry could be mechanically held apart from anything that would react with them, until the desired reaction was lined up.
One of the most important differences is that reactions can be guided to the correct site among hundreds of competing sites. An enzyme might have trouble selecting between the atom five in from the edge, and the one six in from the edge, on a nearly homogeneous surface.
For a mechanical system, selecting an atom is easy: Reactions can be made much more rapid and reliable than in solution-phase chemistry. The reaction rate can be increased dramatically using pressure, concentration, and orientation. Likewise, the equilibrium can be shifted quite far toward the product by means of large energy differences between reactants and product.
Differences that would be quite large -- too large for convenience -- in solution chemistry could easily be accommodated in mechanical chemistry. In a macro-scale mechanical system, wear happens when tiny pieces of a component are broken away or displaced.
Small concentrations of force or imperfections in the materials cause local failure at a scale too small to be considered breakage. But even microscopic flecks of material contain many billions of atoms.
At the nano-scale, the smallest pieces -- the atoms -- are a large fraction of the size of the components. A single atom breaking away or being rearranged would constitute breakage, not wear. This also means that fatigue cannot occur, since fatigue is also a physical rearrangement of the structure of an object, and thus would constitute breakage.
We cannot simply dismiss the problem of wear or fatigue by giving it another name; if mechanical breakage will happen randomly as a result of normal use, then nanomachines will be less reliable than they need to be. Thus, it is important to consider the mechanisms of random breakage.
These include high-energy radiation, mechanical force, high temperature, attack from chemicals, and inherently weak bonds. High-energy radiation, for these purposes, includes any photon or particle with enough energy to disrupt a bond.
The lower frequencies of photon, ultraviolet and below, can be shielded with opaque material. Higher energy radiation cannot be fully shielded, since it includes muons from cosmic rays; for many nanomachines, even shielding from more ordinary background radiation will also be impractical.
So radiation damage is inescapable, but is not a result of mechanical motion -- it is more analogous to rusting than to wear. And it happens slowly: The mechanical force applied to moving parts can be controlled by the design of the machine.
Although an excess of mechanical force can of course break bonds, most bonds are far stronger than they need to be to maintain their integrity, and modest forces will not accelerate bond breakage enough to worry about.
High temperature can supply the energy needed to break and rearrange bonds. At the nanoscale, thermal energy is not constant, but fluctuates randomly and rapidly.
This means that even at low temperatures, it will occasionally happen that sufficient energy will be concentrated to break a bond.
However, this will be rare. Even taking modest mechanical forces into account, a wide variety of molecular structures can be built that will be stable for decades.
See Nanosystems Chapter 6. Various chemicals can corrode certain materials.
Although pure diamond is rather inert, nanomachines may be made of other, more organic molecules. However, harmful chemicals will be excluded from the working volume of nanosystems. The "grit" effect of molecules getting physically caught between moving interfaces need not be a concern -- that is, if random molecules can actually be excluded.
This brings us to the third topic.
The ability to build flawless diamondoid nanosystems implies the ability to build atomically flat surfaces.top pick within the processing styles would be a logical processor and my second pick would be a reactive stimulator.
According to Steven F. Ungvari, the author of the TRIZ website, a logical processor is one who is, “logical, methodical and not easily deterred.
Logical processor and hypothetical analyzer therefore have a negative effect in communication at work. Performer pattern is made up of reactive stimulation and logical processor.
It is therefore seen to be very effective in decision making and average in connecting with others. These “reactive attitudes” can be directed towards peculiar people or even ourselves in the signifier of self-evaluation (pg.
66). When Strawson speaks on the reactive attitude. he gives the illustration of holding bitterness towards an person. REACTIVE STIMULATOR RELATIONAL INNOVATOR LOGICAL PROCESSOR HYPOTHETICAL ANALYZER YOUR SALES PROFILE You can use the above graphic to get an idea of your capacity along each dimension.
the higher you scored on a style. Performer – This orientation pattern combines the styles of Reactive Stimulator and Logical Processor (Salton, ).
Figure 4 (Salton, ) illustrates the various combinations and their resulting strategic patterns, given different primary and secondary strategic profiles. They divide N compounds into reactive and nonreactive, and Develop your argument in support of this statement logically — in a logical order.
This means that you should 1) introduce the focus and intent of your essay, 2) give the Charlene D’Avanzo and the Ecological Society of America.
Teaching Issues and Experiments in Ecology.