Profiling Molecular

A number of friction studies have been carried out on organic polymers in recent years. Coefficients of friction are for the most part in the normal range, with values about as expected from Eq. XII-5. The detailed results show some serious complications, however. First, n is very dependent on load, as illustrated in Fig. XlI-5, for a copolymer of hexafluoroethylene and hexafluoropropylene [31], and evidently the area of contact is determined more by elastic than by plastic deformation. The difference between static and kinetic coefficients of friction was attributed to transfer of an oriented film of polymer to the steel rider during sliding and to low adhesion between this film and the polymer surface. Tetrafluoroethylene (Telfon) has a low coefficient of friction, around 0.1, and in a detailed study, this lower coefficient and other differences were attributed to the rather smooth molecular profile of the Teflon molecule [32]. 

The concept of feature trees as molecular descriptors was introduced by Rarey and Dixon [12]. A similarity value for two molecules can be calculated, based on molecular profiles and a rough mapping. In this section only the basic concepts are described. More detailed information is available in Ref. [12]. 

PTFE is outstanding in this group. In thin films it provides the lowest coefficient of friction (0.03—0.1) of any polymer, is effective from —200 to 250°C, and is generally unreactive chemically. The low friction is attributed to the smooth molecular profile of PTFE chains which allows easy sliding (57). Typical apphcations include chemical and food processing equipment, electrical components, and as a component to provide improved friction and wear in other resin systems. 

Hydrocarbons are segmented into a variety of categories. Each category possesses a distinct molecular profile and, in turn, set of chemical and physical properties. Each class of hydrocarbons therefore has historically served different markets. Crude petroleum is composed of four major hydrocarbon groups paraffins, olefins, naphthenes, and aromatics. 

Other feature of the molecular profile is involved in the interaction. This may frequently be an inert, structural detail having a simple, morphological function in the interaction, or it may, in some cases, be a polar or a polarizable moiety capable of active participation in the interaction in a sense analogous to that postulated by Kier for sweet taste. Systematic studies to test this concept have yet to be conducted. 

Figure 5-18 shows a molecular profile of a column of atmospheric air. 

Molecular profile of the Earth s atmosphere, showing a column above some point on the Earth s surface. As altitude increases, both pressure (P) and molecular density [ 7 decrease. 

Kononen J, Bubendorf L, Kallioniemi A, et al. Tissue microarrays for high-throughput molecular profiling of tumor specimens. Nat. Med. 1998 4 844-847. 

Based on the heat-induced AR principle, DNA/RNA extraction from FFPE tissues can be successfully achieved by a simple heating protocol that allows satisfactory application of molecular analysis using FFPE tissue samples housed in pathology laboratories worldwide. By a combination of improved extraction methods with various innovative techniques of molecular biology, more reliable results of molecular profiling for archival tissue are anticipated. 

Although analytical procedures based on GC/MS analysis usually involve a relatively long analysis time, requiring a wet chemical pretreatment of the samples, they are unsurpassed in their capacity to unravel the molecular composition of the lipids used in works of art and in archaeological findings at a molecular level. In addition to obtaining a qualitative molecular profile, GC permits quantitative or semi-quantitative measurements on specific molecules. 

Recently, a quantitative electrospray ionization/mass spectrometry method (ESI/MS) has been developed to analyze the molecular profile, or hpidome of different lipid classes in very small samples. In this method, total lipid extracts from tissues or cultured cells can be directly analyzed. By manipulating the ionization method, the mass spectrographs of polar or even non-polar lipids can be obtained [8]. This method and the use of lipid arrays allow precise and quantitative identification of the lipid profile of a given tissue, and map functional changes that occur. 

Pierson J, Norris JL, Aerni HR, Svenningsson P, Caprioli RM, et al. 2004. Molecular profiling of experimental Parkinson s disease direct analysis of peptides and proteins on brain tissue sections by MALDI mass spectrometry. J Proteome... 

Emmert-Buck MR, et al. 2000. Molecular profiling of clinical tissue specimens feasibility and applications. Am J Pathol... 

Berg, D. Molecular profiling of signaling pathways in formalin-fixed and paraffin-embedded cancer tissues... 

Espina, V. Reduction of preanalytical variability in specimen procurement for molecular profiling... 

Von H, Stephenson JJ Jr, Rosen P et al (2010) Pilot study using molecular profiling of patients tumors to find potential targets and select treatments for their refractory cancers. J Clin Oncol 28 4877-4883... 

Nam MJ, Madoz-Gurpide J, Wang H, et al. (2003) Molecular profiling of the immune response in colon cancer using protein micro-arrays occurrence of autoantibodies to ubiq-uitin C-terminal hydrolase L3. Proteomics 3, 2108-15. 

DNA Microarrays for Transcription Profiling Tumor Tissue Microarray and Proteomic Profiling Of Protein Kinases Molecular Profiling for Cancer Therapeutics New Guidelines For Reporting Tumor Marker Studies Conclusions References... 

Breast cancer is a complex and heterogeneous disease, encompassing a wide range of pathologic entities and molecular profiles. It is crucial for the physicians to accurately define a patient s risk of developing metastatic and recurrent diseases at diagnosis. This will determine the clinical course for the given patient, that is, which patient should receive expensive and toxic adjuvant therapy and which patient should avoid over-treatment. 

Cleator S, Ashworth A. Molecular profiling of breast cancer clinical implications. Br J Cancer 2004 90 1120-1124. 

Paik S. Molecular profiling of breast cancer. Curr Opin Obstet Gynecol 2006 18 59-63. 

Espina V, Geho D, Mehta AI et al. Pathology of the future molecular profiling for targeted therapy. Cancer Invest 2005 23 36 6. 

Rosenwald A, Wright G, Chan WC et al Lymphoma/ eukemia molecular profiling project. The use of molecular profiling to predict survival after chemotherapy for diffuse large-B-cell lymphoma. N Engl JMed 2002 346 1937-1947. 

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