Solid refractory

The immobility of the surface atoms of a refractory solid has the consequence that the surface energy and other physical properties depend greatly on the immediate history of the material. A clean cleavage surface of a crystal will have a different (and probably lower) surface energy than a ground, abraded, heat-treated or polished surface of the same material. 

Surface defects (Section VII-4C) are also influenced by the history of the sample. Such imperfections may to some extent be reversibly affected by processes such as adsorption so that it is not safe to regard even a refractory solid as having fixed surface actions. Finally, solid surfaces are very easily contaminated detection of contamination is aided by ultra-high-vacuum techniques and associated cleaning protocols [24]. 

The determination of precise physical properties for elemental boron is bedevilled by the twin difficulties of complex polymorphism and contamination by irremovable impurities. Boron is an extremely hard refractory solid of high mp, low density and very low electrical conductivity. Crystalline forms are dark red in transmitted light and powdered forms are black. The most stable ()3-rhombohedral) modification has mp 2092°C (exceeded only by C among the non-metals), bp 4000°C, d 2.35 gcm (a-rhombohedral form 2.45gcm ), A77sublimation 570kJ per mol of B, electrical conductivity at room temperature 1.5 x 10 ohm cm- . 

Mullendore, A., Chemical Vapor Deposition of Boron-based Refractory Solids, AIP Conf. Proc., pp. 4-140, Am Inst, of Physics, New York (1986)... 

Stable oxides, such as those of chromium, vanadium and titanium cannot be reduced to the metal by carbon and the production of these metals, which have melting points above 2000 K, would lead to a refractory solid containing carbon. The co-reduction of the oxides with iron oxide leads to the formation of lower melting products, the ferro-alloys, and this process is successfully used in industrial production. Since these metals form such stable oxides and carbides, the process based on carbon reduction in a blast furnace would appear to be unsatisfactory, unless a product saturated with carbon is acceptable. This could not be decarburized by oxygen blowing without significant re-oxidation of the refractory metal. 

Nitrides. Among the elements of the 15th group, the particular behaviour of nitrogen is notable. Several are the analogies with carbon in the formation, for instance, of interstitial compounds. A number of these phases, such as the refractory solid solution MeN. phases, have been described in 3.8.4 ff. 

Ratain, M., Preliminary antitumor activity of BAY 43-9006 in metastatic renal cell carcinoma and other advanced refractory solid tumors in a phase 11 randomized discontinuation trial (RDT), Proc. Am. Soc. Clin. Oncol., 22, 381, Abstr. 4501, 2004. 

Benzamides constitute a fourth dass of HDAC inhibitors. One example, MS-275, is a phenylenediamine derivative that exhibits robust HDAC inhibition in patients with advanced myeloid leukemia as well as refractory solid tumors or lymphoma in Phase I studies [72]. MS-275 is currently in Phase II trials. In a recent study aimed at optimizing the benzamide scaffold, several bis-(aryl) type analogs were synthesized and evaluated for their activity against a panel of HDACs [85]. Moradei et al. found that a thienyl substitution para to the free amino group in the phenylenediamine core rendered inhibitors specific for HDACsl, 2 with potency superior to that of MS-275. Isoform-specific inhibitors should aid in dissecting the roles of HDACs in normal cellular fundioning and cancer. 

Boron is an extremely hard refractory solid having a hardness of 9.3 on Mohs scale and a very low (1.5 x 10-6 ohm-1 cm-1) room temperature electrical conductivity so that boron is classified as a metalloid or semiconductor. These values are for the CC-rhombohedral form. 

Chen, H.X., Marchall, J.L., Ness, E., Martin, R.R., Dvorchik, B., Rizi, N. et al. (2000) A safety and pharmacokinetic study of a mixed-backbone oligonucleotide (GEM231) targeting the type I protein kinase A by two-hour infusion in patients with refractory solid tumors. Clin. Cancer Res., 6, 1259-1266. 

Lustig RA, Vogl 7], Fromm D, et al, A multicenter phase I safety study of intratumoral photoactivation of talaporfin sodium in patients with refractory solid tumors. Cancer 2003 ... 

DAC (decitabine)+ doxorubicin + cyclophosphamide I Pediatric relapsed/ refractory solid tumors or neuroblastoma NCI... 

Gilbert J, Baker SD, Bowling MK, Grochow L, Figg WD, Zabelina Y, Done-hower RC, Carducci MA. A phase I dose escalation and bioavailability study of oral sodium phenylbutyrate in patients with refractory solid tumor malignancies. Clin Cancer Res 2001 7 2292-2300. 

Moore M et al (2005) Phase I study to determine the safety and pharmacokinetics of the novel Raf kinase and VEGFR inhibitor BAY 43-9006, administered for 28 days on/7 days off in patients with advanced, refractory solid tumors. Ann Oncol 16 1688-1694... 

Fox E et al (2010) A phase 1 trial and pharmacokinetic study of cediranib, an orally bioavail-able pan-vascular endothelial growth factor receptor inhibitor, in children and adolescents with refractory solid tumors. J Clin Oncol 28 5174-5181... 

O Dwyer, P.J., Gallagher, M., Nguyen, B., Waddell, M.J., and Chiorean, E.J. (2010). Phase accelerated dose-escalating safety and pharmacokinetic study of GGTI-2419, a novel geranylgeranyltransferase I inhibitor, in patients with refractory solid tumors. Ann Oncol 21(Suppl. 2) ii42. 

Focusing on the postprenylation enzymes Reel and Icmt is an attractive approach for the development of potential therapeutic agents, especially in refractory solid tumors because their enzymatic functions are unique. Inhibitors for the endoprotease have arisen mainly from the design of substrate-based compounds however, their therapeutic use may be in question because of the recent data indicating the importance of Reel function. On the other hand, inhibitors of Icmt demonstrate promise as therapeutic agents. 

Supko JG, Eder JP Jr, Ryan DP, Seiden MV, Lynch TJ, Amrein PC, Kufe DW, Clark JW. Phase I clinical trial and pharmacokinetic study of the spicamycin analog KRN5500 administered as a 1-hour intravenous infusion for five consecutive days to patients with refractory solid tumors. Clin Cancer Res 2003 9 5178-86. 

In evaluating the mechanistic models for sorption by coals, one is well advised to consider the contrast of the two general classes of sorbents physical adsorption (sometimes called physisorption) will likely alter the surface structure of a molecular solid adsorbent (such as ice, paraffin, and polymers), but not that of high surface energy, refractory solids (such as the usual metals and metal oxides, and carbon black) (9). Adamson (27) has proposed... 

Clark JW, Eder JP, Ryan D, et al. Safety and pharmacokinetics of the dual action Raf kinase and vascular endothelial growth factor receptor inhibitor, BAY 43-9006, in patients with advanced, refractory solid tumors. Clin Cancer Res. 2005 ll(15) 5472-5480. 

Bomgaars LR, Bernstein M, Krailo M, et al. Phase II trial of irinotecan in children with refractory solid tumors a Children s Oncology Group Study. J Clin Oncol 2007 25(29) 4622-7. 

Boron carbide is a solid. It can be burned to release a large amount of energy, but it is a refractory solid, and on combustion, solid boron oxide is formed. Boron nitride is a solid and releases so little energy on combustion it cannot be considered a fuel. 

Wave Astronomy Satellite (SWAS) show the abundance to be less than 0.1% that of CO. At this level, it does not interfere with organic synthesis. With elemental evolution, an increase of the 0/C ratio is expected. If this is not readily incorporated into the refractory solid phase, production of organic species in the interstellar molecular clouds could well be reduced. CO is an abundant molecule in strongly red shifted quasars (Downes and Solomon, 2003) (z = 2.6-6.4). Thus, it would be expected that its reaction products also are present, but harder to observe. SWAS is instrumented to measure O2 abundances and has not observed any. (O2, although lacking an electric dipole moment, has magnetic dipole transitions.) Note that it has probably not been observed in dense molecular clouds. 

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