Modern Trends of Organic Chemistry in Russian Universities

© 2018, Pleiades Publishing, Ltd. This review is devoted to the scientific achievements of the departments of organic chemistry in higher schools of Russia within the past decade

TU‐E‐217BCD‐04: Spectral Breast CT: Effect of Adaptive Filtration on CT Numbers, CT Noise, and CNR

Purpose: Photon counting spectral breast CT is feasible in part due to using an adaptive filter. An adaptive filter provides flat x‐ray intensity profile and constant x‐ray energy spectrum across detector surface, decreases required detector count rate, and eliminates beam hardening artifacts. However, the altered x‐ray exposure profiles at the breast and detector surface may influence the distribution of CT noise, CT numbers, and contrast to noise ratio (CNR) across the CT images. The purpose of this work was to investigate these effects. Methods: Images of a CT phantom with and without adaptive filter were simulated at 60kVp, 90kVp, and 120kVp tube voltages and 660 mR total skin exposure. The CT phantom with water content had 14cm diameter, contrast elements representing adipose tissue and 2.5mg/cc iodine contrast located at 1cm, 3.5cm, and 6cm from center of the phantom. The CT numbers, CT noise, and CNR were measured at multiple locations for several filter/exposure combinations: (1)without adaptive filter for 660mR skin exposure; (2)with adaptive filter for 660mR skin exposure along central axis (mean skin exposure across the breast was \u3c660mR); and (3)with adaptive filter for scaled exposure (mean skin exposure was 660mR). Results: Beam hardening (cupping) artifacts had 47HU magnitude without adaptive filter but were eliminated with adaptive filter. CNR of contrast elements was comparable for (1) and (2) over central parts but was higher by 20–30% for (1) near the edge of the phantom. CNR was higher by 20–30% in (3) as compared to (2) over central parts and comparable near the edges. Conclusions: The adaptive filter provided: uniform distribution of CT noise, CNR, and CT numbers across CT images; comparable or better CNR with no dose penalty to the breast; and eliminated beam hardening artifacts. © 2012, American Association of Physicists in Medicine. All rights reserved

Reaction of substituted 1-methylthio-4,5-dihydro[1,2]dithiolo[3,4-c]-quinolin iodides with arylamines. Synthesis of novel 1,2-dithiolo[3,4-c]-quinolin-1-ylidene(aryl)amines and 10-(arylimino)-7,10-dihydro[1,2]dithiolo[3,4-c]-pyrrolo[3,2,1-ij]quinoline-4,5-diones

A series of novel (8-R-7-R'-4,4-dimethyl-4,5-dihydro-1H-[1,2]dithiolo[3,4-c]quinolin-1-ylidene)(4(2)-R"- phenyl)amines were synthesized by reaction of 4,4-dimethyl-1-methylthio-4,5-dihydro[1,2]dithiolo[3,4- c]quinolin iodides with arylamines in an efficient manner. The Stolle type reaction of the obtained compounds with oxalyl chloride gave 2-R-3-R'-10-[(4(2)-R"-phenyl)imino]-7,7-dimethyl-7,10-dihydro[1,2]dithiolo[3,4- c]pyrrolo[3,2,1-ij]quinoline-4,5-diones. The structure of the synthesized compounds were characterized by NMR spectroscopy, mass-spectrometry and elemental analyses. © 2017 Arkat USA, Inc

A new synthetic route to polyhydrogenated pyrrolo[3,4-b]pyrroles by the domino reaction of 3-bromopyrrole-2,5-diones with aminocrotonic acid esters

A new synthetic approach to polyfunctional hexahydropyrrolo[3,4-b]pyrroles was developed based on cyclization of N-arylbromomaleimides with aminocrotonic acid esters. A highly chemo- and stereoselective reaction is a Hantzsch-type domino process, involving the steps of initial nucleophilic C-addition or substitution and subsequent intramolecular nucleophilic addition without recyclyzation of imide cycle. © 2017 by the authors

Reaction of substituted 1-methylthio-4,5-dihydro[1,2]dithiolo[3,4-c]-quinolin iodides with arylamines. Synthesis of novel 1,2-dithiolo[3,4-c]-quinolin-1-ylidene(aryl)amines and 10-(arylimino)-7,10-dihydro[1,2]dithiolo[3,4-c]-pyrrolo[3,2,1-ij]quinoline-4,5-diones

A series of novel (8-R-7-R'-4,4-dimethyl-4,5-dihydro-1H-[1,2]dithiolo[3,4-c]quinolin-1-ylidene)(4(2)-R"- phenyl)amines were synthesized by reaction of 4,4-dimethyl-1-methylthio-4,5-dihydro[1,2]dithiolo[3,4- c]quinolin iodides with arylamines in an efficient manner. The Stolle type reaction of the obtained compounds with oxalyl chloride gave 2-R-3-R'-10-[(4(2)-R"-phenyl)imino]-7,7-dimethyl-7,10-dihydro[1,2]dithiolo[3,4- c]pyrrolo[3,2,1-ij]quinoline-4,5-diones. The structure of the synthesized compounds were characterized by NMR spectroscopy, mass-spectrometry and elemental analyses. © 2017 Arkat USA, Inc

A new synthetic route to polyhydrogenated pyrrolo[3,4-b]pyrroles by the domino reaction of 3-bromopyrrole-2,5-diones with aminocrotonic acid esters

A new synthetic approach to polyfunctional hexahydropyrrolo[3,4-b]pyrroles was developed based on cyclization of N-arylbromomaleimides with aminocrotonic acid esters. A highly chemo- and stereoselective reaction is a Hantzsch-type domino process, involving the steps of initial nucleophilic C-addition or substitution and subsequent intramolecular nucleophilic addition without recyclyzation of imide cycle. © 2017 by the authors

WE‐E‐201C‐09: Intravascular Imaging with Storage Phosphor Detector

Purpose: To develop and test an intravascular positron imaging system based on a storage phosphor (SP) detector for imaging vulnerable plaques of human coronary arteries. Materials and methods: The positron‐emitting radiotracer F18‐FDG accumulates in vulnerable arterial plaques with inflamed overlying cap; thus vulnerable plaques could be imaged by an intravascular positron detector located at the end of a cardiac catheter. An experimental intravascular imaging detector was constructed as a SP tube with 55 mm length, 2 mm diameter, and 0.28 mm wall thickness. A light diffuser with 0.9 mm diameter and 55 mm length is inserted into the SP tube to erase signal accumulated in the SP during fluoroscopic guidance of catheter insertion. The light diffuser was connected to a 0.38 W laser source through a 2 m long optical fiber. A heart phantom with 300 cm3 volume, and 3.2 mm diameter coronary arteries with plaques was fabricated. 0.5 μCi/cm3 FDG solution filled the heart and coronary arteries, with a range of activities in the plaques. The detector was inserted in a coronary artery and the plaques were imaged for 2 min. The detector was extracted and read out in 2 min using a SP reader. Results: The light diffuser erased the fluoroscopic x‐ray signal of the SP to background levels. Vulnerable plaques with area activities of 1.2 nCi/mm2 and higher were visualized. This activity is a factor of 10 lower than that expected in human vulnerable plaques. The detector can image the internal surface of 50 mm long vessels with 0.6 mm FWHM spatial resolution in a single measurement. The detector is flexible, easy to handle, and provides virtually real time imaging. Conclusion: The intravascular detector provides sensitivity, spatial resolution, flexibility, and imaging times that are well suited for clinical imaging of vulnerable plaques of human coronary artery. © 2010, American Association of Physicists in Medicine. All rights reserved