Andrew ( Gabriel ) Livshits
With each new pilot project in the field of biomedical technologies and open new opportunities for commercialization
It seems our international group of researchers , even from short publications and reports on the results of various studies and health checks ideas and discoveries , using methods and techniques to eliminate all kinds of contradictions , we can formulate and selectively choose those in which there is potential for innovation
Below are details of some of these studies and each reader can on the basis of this information, using known of TRIZ and ARIZ methods and techniques to transform analytically and classify this information as a base for a new biomedical project
Engineers at MIT have created a water-repellent nano-coating , from which droplets condensing vapor jump yourself. The work is published in the journal Nano Letters, and a brief summary can be read on the website of the institute.
Created by the authors structured surface looks under the microscope as lawn of crystals of copper oxide . When applied to the appropriate coating it , its water repellency become so pronounced that the drops of condensed steam on it hardly hold.
Moreover, a merger of two smaller droplets released energy becomes sufficient to obtain large drop itself jumped from the surface.
Engineers aim to create unusual surfaces was increased thermal conductivity of heat exchangers in steam condensers . The fact that by using this conventional copper tubing at the surface thereof a water film is quickly formed , which prevents heat transfer .
The faster the liquid droplets are removed from the heat exchanger , the higher the efficiency , so recently have spread heat exchangers with a pronounced hydrophobic surface .
The authors showed that the new surface allows a third increase rate of heat transfer , even when compared with the latest hydrophobic heat exchangers. Because these devices are used , including power plants, such efficiency gains can be regarded as very significant.
Earlier, another group of engineers (also of MIT) to solve the problem of increasing the heat transfer rate used a similar approach . Scientists have also created a hydrophobic surface micro-texture , but last version of this sophisticated technology is used photolithography rather than chemical treatment .
Scientists from the University of Genoa in Italy have developed a technology of electron microscopy , which allowed for the first time to consider the DNA coils . The work is published in the journal Nano-letters, and its summary results New Scientist.
To obtain an image scientists had to create an entirely new substrate on which the nucleic acid was recorded . She had microscopic support, which was stretched between the DNA strand , with a substrate molecule to make holes for the electron beams .
As a result , scientists have been able to obtain an image in which the grooves are clearly visible . A- form DNA
The thickness of the molecule in the image does not correspond to reality. Perhaps this is due to the fact that in the single molecule is not used and six strands of nucleic acids. Impossibility of working with a single DNA was attributed to insufficient sensitivity matrices that photograph electrons . Because of this, during the desired exposure image single molecules have time to collapse under the influence of electron bombardment .
New technology will allow to study DNA -protein interactions (eg , landing site of transcription factors ) directly to individual nucleic acid molecules .
Earlier, another group of scientists learned by atomic force microscopy to determine the sequence of nucleotides in DNA .
Ion channels - this is one of the main instruments through which the cell exchanges matter with the outside world . These complex molecular devices like Doorman at the checkpoint at the same time and analyze molecules and control the flow of particles through the cell membrane .
German scientists , creators of artificial versions of such a channel , believe that their analogue can perform both functions. The bandwidth parameters define the ion channels (shape, the diameter of the charge passing through the channel of the molecule) , and these parameters can be varied as desired researchers.
Analytical possibilities of the artificial channels have been confirmed by a series of experiments , also comparable with natural they reliably distinguish the polymer molecules along the length and configuration.
As is known, in the bilayer lipid membrane cells embedded protein complexes that control the flow of inter alia different molecules inside the cell and outside. And may serve as a pass -specific molecule recognized by the surface receptor and the size and configuration , and the charge of the molecules. Some of these membrane complexes called ion channels , through which charged particles are sent outside or inside the cell.
All processes that depend on a potential difference across the membrane , - a lot of - based on the operation of ion channels . Any living creature depends on its ion channels without them impossible passage of nerve impulses ( one that's enough! ) Muscle contractions , water exchange and much more. Study of the principles of their actions and their classification according to the functions and structure of the branch of science devoted to the remarkable physiology.
And now biotechnologists reached that designed and made working artificial ion channel . They attracted by the idea to simulate channel with predictable properties. Creators version artificial ion channels were German scientists from the Technical University of Munich and the University of Michigan in Ann Arbor (USA). They decided to liken his creation natural channel alpha- hemolysin - protein - toxins produced by staphylococci and streptococci . This is one of the most studied channel complexes , its structure first deciphered and arranged it easier others.
The mechanism of alpha- hemolysin as follows. As known, different concentrations of ions inside and outside of cells differ . For example , many potassium ions inside the cell and the outside small and sodium ions - contrary, many small outside and inside. Because of this, there is a potential difference between the inner and outer surfaces of the cell membrane - the membrane potential (more about him in the note discovered yet another way by which neurons control their anxiety, "Elements" , 15.07.2010 ) . This potential, as already mentioned above, the " tied" to a huge number of processes occurring in the cell - for example, with its help are transported across the membrane of certain substances (see symport ) . Therefore, the presence of the membrane potential is essential for the life of the cell .
And here are some pathogenic bacteria (eg , streptococci and staphylococci ) learned how to use the fact that a violation of the membrane potential of the cell dies . Once outside the cell , these bacteria start to secrete proteins , which are collected in an ion channel - hemolysin - on the cell membrane . This channel , in contrast to the " respectable " normal channels of the membrane , passes are not strictly specific ions on a specific moment, and all the ions in a row and consistently (ie , in fact , this is not a channel , but simply a "hole" , it's time ) . As a result of ion concentrations on both sides of the membrane are aligned , the membrane potential disappears and the cell dies. Most vulnerable to such attacks red blood cells , red blood cells , and, in fact , so hemolysin ( from the Greek ' dissolving blood ') and got its name.
Of course, scientists channel need not to kill cells. Such a channel , like Maxwell's demon , would allow to sort on one side of the membrane strictly defined molecule. And to use such property can be in every one.
Alpha - hemolysin consists of seven ( six to eight ) the protein subunits that form a hollow barrel . This barrel is attached to the membrane hydrophobic Donets . Attached to the Donets tube lysine and glutamate , it is something and passes through the membrane . Bore tube of 2.2 nm , in the narrowest part of the attachment to the Donets - about 1.5 nm. Approximately the same shape structure , but the basis of their DNA biotechnology German modeled .
DNA in this case was very comfortable molecule. By setting the primary structure of the molecule (i.e., a sequence of nucleotides) , and can predict its secondary and tertiary structure. In other words, to obtain a molecule predetermined shape and size.
In contrast to proteins which are known to twenty monomer - amino - between which there is a complex relationship (each possible pair of amino acids can be strongly or weakly attracted or repelled depending on the charge , solubility in water and fats , and so on ) , the DNA is formed only four nucleotides , which are simple relations between adenine binds with thymine , and guanine - cytosine with . Therefore, to create several single-stranded DNA segments spatial complex with desired properties is easy - it's like making models of matches . Where " match " (ie, DNA segments ) must be connected , it is necessary to put a " clip " - short segments oligonucleotide complementary to a desired site " matches ." At the same DNA " match " is much more interesting spatially than conventional wooden matches if they fasten certain way, they can bend and inform the final three-dimensional structure even more complex form . Of course, things are not so simple, and we must always calculate the structure of the complex so that each other would not connect anything superfluous. However, when used properly , this technique ( also known as " DNA origami " , see DNA origami) can create quite a complex three-dimensional systems with desired properties .
In this paper it has been done successfully . Researchers created an artificial DNA origamny channel , the main characteristics of which coincided with those of alpha- hemolysin : the pore diameter was 2 nm , a length of about 47 nm , the strength of the ion flow nanosimensa 0.87 ( on ion currents through the channels discussed in chapter " Nernst equation and the ion flux " in the book "Molecular biology of the Cell "). First channel itself built on the membrane , and then , entrenched , began to conduct the ion current through the membrane. Current through a single channel , as expected, was more or less constant .
Just as cellular ion channels , artificial analogues of single stranded DNA can pass from one side to the other membrane . When passing through the channel of the DNA molecule hole closes and the current is blocked. Therefore, the passage of molecules through the pores are judged by a characteristic picture of the current jumps : the moment of passage of large molecules through the channel on the net current looks like a local minimum. The more complicated the molecule on passing loops and attached balances the longer the current lock and the less time the channel is open . For each of the species studied molecules , scientists have documented their specific pattern passing through the channel. This means that using synthetic ion channel molecules can be analyzed in solution.
And if the building structure of DNA to make small changes ? Of course, such changes should be , which conceived the researcher , who wished to get more bandwidth. Indeed , simulating loop structure building blocks of DNA , scientists have channels with the specified characteristics .
It is clear that the construction of artificial ion channels - this is an area of future technologies . It is assumed that these nano-devices will not only promising molecular analyzers , but also medicinal agents with a broad area of applications. Let us hope that it is not very distant future , here science develops downright c space velocity. Here, for example , a funny remark from the article: "In the past it has been shown that nano-scale membrane pores can potentially be extremely useful monomolecular biosensors " (and then a few references) . Judging by these links , the " past" of the authors believe , 2001-2010 . Past rapidly carried away , but also rapidly approaching future.