Shoulder formation

The risk of development of colorectal cancer increases with the extent and the duration of the disease, Focal wall thickening, shoulder formation, or large polypoid lesions are suspicious for the development of colorectal cancer (Fig. 13.9. a-c). Differentiation between an inflammatory stenosis in ulcerative colitis and cancer is the domain of endoscopy with biopsy, but CTC maybe used as an adjunct in patients with an endoscopically non-assessable colon. 

Fig. 13.9a-c. Ulcerative colitis with stenotic cancer in the transverse colon (arrow) local flattening and disappearance of the haustra in the sigmoid and descending colon (a). Focal, stenotic, circular wall thickening with shoulder formation in the transverse colon, with soft tissue attenuation and CM enhancement (b,c). Combined 2D+3D view of the stenotic cancer (c)... 

Colorectal cancer typically shows extensive focal polypoid, asymmetric, or circular wall thickening with short extension (<5 cm), especially with shoulder formation (Fenlon et al. 1998 Taylor et al. 2003a). Colorectal carcinomas show moderate enhancement with intravenous contrast (Oto et al. 2003 Sosna et al. 2003) (Fig. 13.13a,b). CT differentiation between stage Tl (invasion of mucosa and/or submucosa) and T2 (invasion of the muscularis propria) is not feasible, but tumor extension beyond the colon wall (T3), characterized by stranding, an indistinct boundary, and nodular protrusions into pericolic fat tissue, is readily appreciated by CT (Fig. 13.14a,b). Tumor infiltration to adjacent organs (T4) is most likely if the carcinoma shows a broad-based contact, no intervening fat planes, and indistinct boundaries... 

Fig. 13.14a,b. Semicircular sigmoid carcinoma (arrow) focal, asymmetric, semicircular wall thickening with shoulder formation in the sigmoid colon (a,b). The lesion shows CM enhancement and pericolic soft tissue stranding (b)... 

Fig. 13.16a-d. Segmental colonic spasm in the descending colon (arrow) focal, irregular circular wall thickening with shoulder formation in the supine position (a-c). The lesion shows soft tissue attenuation and CM enhancement (a). Normal colon wall without wall thickening or stenosis in the prone position (d). It is important to identify the same segment as in the supine position... 

The species S3 (absorbing at 420 nm) and S4 (absorbing at 530 nm) have been detected by reflection spectra in the condensate but the formation of S4 is unexplained [16]. S3 and SO2 have also been observed by Raman spectroscopy in such samples [15] (the expected S4 Raman line at 678 cm was probably obscured by the SS stretching mode of S2O at 673 cm but a shoulder at the high-frequency side of the S2O line indicates that some S4 may have been present). While the reddish colors turn yellow on warming at about -120 °C, the sulfur radicals could be observed by ESR spectroscopy up to 0 °C [10]. If the condensation of S2O gas is performed very slowly at -196 °C the condensate is almost colorless and turns red only if the temperature is allowed to increase slowly. Hence, it has been suspected that S2O is actually colorless like SO2. 

After the reaction for 5 h in a reactant stream of CH , O, and Hj (P(CHJ= 33.7, P(0,)= 8.4 and P(H2)= 50.7 kPa), the catalyst was analyzed by XRD, Mossbauer and XPS studies. As regarding the XRD and Mossbauer spectroscopic measurements, obvious changes were not observed before and after the reaction. On the other hand, a marked change was observed in the XPS spectrum of the catalyst after the reaction. As shown in Fig. 2, besides the peak at 57.7 eV, which was the only peak of Fe3p obtained for the sample before the reaction and was ascribed to Fe(III), a clear shoulder at 56.1 eV was observed after the reaction. This can be ascribed to the Fe(ll) on the catalyst surface. The same phenomenon has been reported for FeP04 catalyst [13]. Such observations suggest the occurrence of the redox of iron between Fe(Iil) and Fe(II) during the reaction. We believe that this redox plays a key role in the formation of a new active center and thus is important in the selective oxidation of CH4... 

SEC analysis shows that some samples have a blmodal MWD. At this time it is not possible to tell whether the bimodallty is an artifact of the polymerization mechanism or, perhaps, a consequence of partial hydrolysis of the polymer i.e., the high MW shoulder in Figure 5 may be due to the formation of aggregates through Intermolecular dipolar interactions of P-OH side groups or to polymer molecules crosslinked by P-O-P bonds. 

TGA, iodometric, mid-IR, luminescence (fluorescence and phosphorescence) and colour formation (yellowness index according to standard method ASTM 1925) were all employed in a study of aspects of the thermal degradation of EVA copolymers [67], Figure 23 compares a set of spectra from the luminescence analysis reported in this work. In the initial spectra (Figure 23(a)) of the EVA copolymer, two excitation maxima at 237 and 283 nm are observed, which both give rise to one emission spectrum with a maximum at 366 nm weak shoulders... 

The sulfuric acid treated aliquot representing the blank forms a cyclic ether anhydroerythromycin.10 The alkaline treatment causes the formation of an unsaturated ketone (9-keto-10-ene) having its absorbance maximum as a shoulder at 236 nm. (e 6000).n i2 Thus, any other UV absorbing species are measured with the blank and subtracted from the absorbance before calculation of the erythromycin concentration. A typical spectrum is shown in Figure 4. 

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