Screening methods for early detection of colorectal cancers and polyps

Leningrad Regional Oncology Dispensary, Saint Petersburg, Russia, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroduction: According to a report by the International Agency for Research on Cancer (IARC), in 2019 around 18.1 million new cases of cancer were recorded worldwide. In Russia due to the underdevelopment of early diagnosis, the detection of cancer often happens too late, only in the 3rd and 4th stages. In Russia the incidence of colorectal cancer is increasing. In the structure of malignant tumors, colorectal cancer is the 3rd in terms of incidence and 2nd in mortality. CRC ranks second in mortality from malignant neoplasms among men and women. Most often, CRC arises from colon adenomas, and in some cases in patients with hereditary polyposis syndromes. Methods and materials: Screening takes place in the overall program, which includes: primary prevention (diet, lifestyle), timely examination with the use of colonoscopy (where available and corresponds to the level of the screening program) in patients with positive screening results and timely treatment (polypectomy, surgery). Results: Modern screening centers should have devices with the maximum resolution (electronic endoscopy in HD format). For more clear details and more accurate differentiation of the tumor, virtual chromography allows to detect blood vessels and other tissue structures in the narrow-spectrum zone without the application of dyes. The zoom-endoscopy method is based on a change in the focal distance between the lenses at the distal end of the device. Conclusions: Modern treatment of colon tumors includes: CSP (Cold snare polypectomy), HSP (Hot snare polypectomy), EMR (Endoscopic mucosal resection), ESD (Endoscopic submucosal dissection), FTRD (Full-thickness resection). Every year In Oncology Dispensary of Leningrad Regional, more than 10 thousand outpatient examinations and more than 400 endoscopic inpatient operations are performed

Capsule endoscopy for screening colon tumors

Department of General Surgery with a course of endoscopy of the Federal State Budgetary Educational Institution of Higher Education and Medical University of the Ministry of Health of Russia, Leningrad Regional Oncologic Dispensary, Department of Faculty Surgery. prof. A.A. Rusanov of the Federal State Budgetary Educational Institution of Higher Education and Medical University of the Ministry of Health of Russia, Sankt-Petersburg, Russia, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroduction: Most of the colon tumors are detected in the later stages. The introduction of new, minimally invasive technologies into clinical practice allows to improve the results of the diagnosis of neoplasms. Material and methods: Capsule endoscopy is a procedure for colon examination using a miniature camera, which takes more than 10,000 images of colon at a speed of 4 to 24 frames per second. For the patient, the procedure itself does not cause discomfort. On the day of the study, the patient may do his usual activities. The indications for capsular examination of the colon may be suspected tumor of the colon, a positive test of fecal occult blood test, and the patient is over 50 years old. We made a decision to launch a pilot project for screening the colon among health care workers in Oncology Dispensary of Leningrad Region. Results: In the years 2017-2018, we performed 67 capsule colon examinations for medical workers who had not previously performed a colonoscopy. A total colon investigation was performed in 58 patients (87%). Among these patients 2 malignant tumors of the colon (3.5%) were detected. Colon epithelial neoplasia was detected in 11 patients (19%). These findings contributed to perform colonoscopy with endoscopic polypectomy. Conclusion: Capsule endoscopy of the colon can be used for examination, in cases where colonoscopy is not possible. Capsule endoscopy helps to convince the patient of the need to perform colonoscopy. Capsule endoscopy is a safe method for screening colorectal cancer

Field induced dx2−y2+idxyd_{x^2-y^2}+id_{xy} state and marginal stability of high-Tc superconductors

It is shown that the {\em complex} $d_{xy}$ component is generated in d-wave superconductor in the magnetic field. As one enters superconducting state at finite field the normal to superconducting transition occurs into bulk $d_{x^2-y^2}+i d_{xy}$ state . The driving force for the transition is the linear coupling between magnetic field and non zero magnetization of the $d_{x^2-y^2}+i d_{xy}$ condensate. The external magnetic field violates parity and time reversal symmetries and the nodal quasiparticle states respond by generating the $id_{xy}$ component of the order parameter, with the magnitude estimated to be on the order of few Kelvin. Parity (P) and time reversal (T) symmetries are violated in this state.Comment: 4 pages, latex file with two eps figure file

Gaps and excitations in fullerides with partially filled bands : NMR study of Na2C60 and K4C60

We present an NMR study of Na2C60 and K4C60, two compounds that are related by electron-hole symmetry in the C60 triply degenerate conduction band. In both systems, it is known that NMR spin-lattice relaxation rate (1/T1) measurements detect a gap in the electronic structure, most likely related to singlet-triplet excitations of the Jahn-Teller distorted (JTD) C60^{2-} or C60^{4-}. However, the extended temperature range of the measurements presented here (10 K to 700 K) allows to reveal deviations with respect to this general trend, both at high and low temperatures. Above room temperature, 1/T1 deviates from the activated law that one would expect from the presence of the gap and saturates. In the same temperature range, a lowering of symmetry is detected in Na2C60 by the appearance of quadrupole effects on the 23Na spectra. In K4C60, modifications of the 13C spectra lineshapes also indicate a structural modification. We discuss this high temperature deviation in terms of a coupling between JTD and local symmetry. At low temperatures, 1/T$_1$T tends to a constant value for Na2C60, both for 13C and 23Na NMR. This indicates a residual metallic character, which emphasizes the proximity of metallic and insulting behaviors in alkali fullerides.Comment: 12 pages, 13 figure

Metal-insulator transitions: Influence of lattice structure, Jahn-Teller effect, and Hund's rule coupling

We study the influence of the lattice structure, the Jahn-Teller effect and the Hund's rule coupling on a metal-insulator transition in AnC60 (A= K, Rb). The difference in lattice structure favors A3C60 (fcc) being a metal and A4C60 (bct) being an insulator, and the coupling to Hg Jahn-Teller phonons favors A4C60 being nonmagnetic. The coupling to Hg (Ag) phonons decreases (increases) the value Uc of the Coulomb integral at which the metal-insulator transition occurs. There is an important partial cancellation between the Jahn-Teller effect and the Hund's rule coupling.Comment: 4 pages, RevTeX, 3 eps figure, additional material available at http://www.mpi-stuttgart.mpg.de/docs/ANDERSEN/fullerene

Cellular Origins of EGFR-Driven Lung Cancer Cells Determine Sensitivity to Therapy

Targeting the epidermal growth factor receptor (EGFR) with tyrosine kinase inhibitors (TKIs) is one of the major precision medicine treatment options for lung adenocarcinoma. Due to common development of drug resistance to first- and second-generation TKIs, third-generation inhibitors, including osimertinib and rociletinib, have been developed. A model of EGFR-driven lung cancer and a method to develop tumors of distinct epigenetic states through 3D organotypic cultures are described here. It is discovered that activation of the EGFR T790M/L858R mutation in lung epithelial cells can drive lung cancers with alveolar or bronchiolar features, which can originate from alveolar type 2 (AT2) cells or bronchioalveolar stem cells, but not basal cells or club cells of the trachea. It is also demonstrated that these clones are able to retain their epigenetic differences through passaging orthotopically in mice and crucially that they have distinct drug vulnerabilities. This work serves as a blueprint for exploring how epigenetics can be used to stratify patients for precision medicine decisions

Flat bands in topological media

Topological media are systems whose properties are protected by topology and thus are robust to deformations of the system. In topological insulators and superconductors the bulk-surface and bulk-vortex correspondence gives rise to the gapless Weyl, Dirac or Majorana fermions on the surface of the system and inside vortex cores. Here we show that in gapless topological media, the bulk-surface and bulk-vortex correspondence is more effective: it produces topologically protected gapless fermions without dispersion -- the flat band. Fermion zero modes forming the flat band are localized on the surface of topological media with protected nodal lines and in the vortex core in systems with topologically protected Fermi points (Weyl points). Flat band has an extremely singular density of states, and we show that this property may give rise in particular to surface superconductivity which could exist even at room temperature.Comment: 9 pages, 5 figures, version to appear in JETP Letter

Endoscopic treatment of patients with early forms of gastric cancer

Leningrad regional oncological dispensary, Russia, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaBackground: Currently, most patients with gastric tumors are detected in late stages. Early diagnosis is a major factor in improving treatment outcomes. On the other hand, patients who are diagnosed on early stages often receive aggressive treatment and are not subjects to less invasive interventions. Material and Methods: In our clinic we have been using endoscopic surgery for early gastric cancer since 2009. Japanese colleagues are the most experienced in this kind of treatment that is why we follow the recommendations of Japanese Gastric Cancer Association (JGCA). The main criterion provided that endoscopic removal is possible is the depth of tumor invasion. We evaluate the depth of invasion primarily by endoscopic ultrasonography. According to our data the accuracy of this method is 94%. The main operation used for the treatment of early gastric cancer is endoscopic submucosal dissection (ESD). Its main advantages are single block resection within healthy tissues and adequate morphological assessment of the removed tumor. In the last ten years we have performed 148 ESD (145 patients) for early forms of gastric cancer. Surgeries were radical in 95% of cases. Results:There were no cases of postoperative mortality. Progression of the disease was noted only in one patient. These endoscopic surgeries have proved to be effective, safe and reasonable in treating early gastric cancer. Conclusions: Thus, endoscopic surgery significantly reduces the cost of treatment and hospital stay (average - 3.7 days), facilitates rehabilitation and improves the quality of patients’ life

The degenerate 3-band Hubbard model with "anti-Hund's rule" interactions; a model for AxC60

We consider the orbitally degenerate 3-band Hubbard model with on-site interactions which favor low spin and low orbital angular momentum using standard second order perturbation theory in the large Hubbard-U limit. At even integer filling this model is a Mott insulator with a non-degenerate ground state that allows for a simple description of particle-hole excitations as well as gapped spin and orbital modes. We find that the Mott gap is generally indirect and that the single particle spectrum at low doping reappears close to even filling but rescaled by a factor 2/3 or 1/3. The model captures the basic phenomenology of the Mott insulating and metallic fullerides AxC60. This includes the existence of a smaller spin gap and larger charge gap at even integer filling, the fact that odd integer stoichiometries are generally metallic while even are insulating, as well as the rapid suppression of the density of states and superconducting transition temperatures with doping away from x=3.Comment: Revised with additional reference

Raman spectroscopy as a versatile tool for studying the properties of graphene.

Raman spectroscopy is an integral part of graphene research. It is used to determine the number and orientation of layers, the quality and types of edge, and the effects of perturbations, such as electric and magnetic fields, strain, doping, disorder and functional groups. This, in turn, provides insight into all sp(2)-bonded carbon allotropes, because graphene is their fundamental building block. Here we review the state of the art, future directions and open questions in Raman spectroscopy of graphene. We describe essential physical processes whose importance has only recently been recognized, such as the various types of resonance at play, and the role of quantum interference. We update all basic concepts and notations, and propose a terminology that is able to describe any result in literature. We finally highlight the potential of Raman spectroscopy for layered materials other than graphene