Efficient Certified Resolution Proof Checking

We present a novel propositional proof tracing format that eliminates complex processing, thus enabling efficient (formal) proof checking. The benefits of this format are demonstrated by implementing a proof checker in C, which outperforms a state-of-the-art checker by two orders of magnitude. We then formalize the theory underlying propositional proof checking in Coq, and extract a correct-by-construction proof checker for our format from the formalization. An empirical evaluation using 280 unsatisfiable instances from the 2015 and 2016 SAT competitions shows that this certified checker usually performs comparably to a state-of-the-art non-certified proof checker. Using this format, we formally verify the recent 200 TB proof of the Boolean Pythagorean Triples conjecture

COMPARATIVE ANALYSIS OF RADIOLOGIC ASPECTS OF FACET JOINTS IN SURGICAL TREATMENT OF PATIENTS WITH DEGENERATIVE DISEASES OF THE LUMBAR SPINE

Objective To study the radiologic characteristics of facet joints at different stages of the degenerative process in the lumbar spine to determine the indications for various methods of fixing the affected segment and to evaluate the results of treatment.Material and Methods To determine the radiologic aspects of facet joints in the affected area and in  adjacent segments of the lumbar spine, two groups were formed, including 136 patients who underwent multispiral computed tomography in two-energy mode before surgery and 12 months after surgery. Group I included patients who underwent rigid fixation of the spine (360°), and group II included patients who underwent dynamic fixation using nitinol rods (180°).Results Based on a comprehensive instrumental study, it was found that the degeneration of the intervertebral disc according to Pfirrmann II and III revealed an increase in the density of the cartilaginous plate in facet joints (HU). These digital indicators confirm the preservation of joint functionality, both in the affected area and in adjacent segments. With severe degrees of disk degeneration in Pfirrmann IV and V and facet joints, deep pathological changes occurred, directed towards the loss of facet joints functionality.Conclusion The obtained digital indicators of dual-energy computed tomography for the state of facet joints  in combination with the results of magnetic resonance imaging can be used as criteria in a complex of patient studies to assess the degree of degeneration of the vertebral motion segment in the affected area and adjacent segments. We recommend using these criteria as a diagnostic component for finding optimal methods of surgical treatment

CT-IGFBP-4 as a novel prognostic biomarker in acute heart failure

Aims Insulin-like growth factor binding protein-4 (IGFBP-4) fragments have been shown to predict the risk of major adverse cardiovascular events, including segment-elevation myocardial infarction, in patients with acute coronary syndrome. We evaluated the prognostic value of the carboxy-terminal fragment of IGFBP-4 (CT-IGFBP-4) for all-cause mortality in emergency room patients with acute heart failure (AHF). Methods and results CT-IGFBP-4, N-terminal pro brain natriuretic peptide (NT-proBNP), and C-reactive protein (CRP) were measured at admission from the lithium-heparin plasma of 156 patients with AHF. All-cause mortality was recorded for 1 year. Receiver operator characteristic (ROC) curves, Kaplan-Meier, and Cox proportional hazard ratio analyses were performed to evaluate the prognostic value of the various clinical variables, CT-IGFBP-4, NT-proBNP, CRP, and their combinations. During 1 year of follow-up, 52 (33.3%) patients died. CT-IGFBP-4 only weakly correlated with NT-proBNP (Pearson correlation coefficient r = 0.16, P = 0.044) and did not correlate with CRP (r = 0.08, P = 0.35), emphasizing the different nature of these biomarkers. The receiver operator characteristic area under the curve (ROC AUC) of CT-IGFBP-4 for the prediction of all-cause mortality (0.727) was significantly higher than that of NT-proBNP (0.680, P = 0.045) and CRP (0.669, P = 0.016). The combination of CT-IGFBP-4, NT-proBNP, and CRP predicted mortality significantly better (ROC AUC = 0.788) than any of the biomarkers alone (P <0.01 for all). The addition of CT-IGFBP-4 to a clinical prediction model that included age, gender, systolic blood pressure, creatinine, and sodium levels, as well as the history of previous heart failure, coronary artery disease, and hypertension significantly improved the mortality risk prediction (ROC AUC 0.774 vs. 0.699, P = 0.025). Cox hazard analysis indicated that elevated CT-IGFBP-4 was independently associated with 1 year mortality (hazard ratio 3.26, P = 0.0008) after adjustment for age, gender, history of previous heart failure, coronary artery disease, hypertension, chronic kidney failure, history of diabetes, heart rate, haemoglobin, plasma sodium, NT-proBNP, CRP, cystatin C, and elevated cardiac troponin I or T. Patients with increased levels of either two or three of the biomarkers CT-IGFBP-4, NT-proBNP, and CRP had significantly higher mortality risk (adjusted hazard ratio 10.04, P <0.0001) than patients with increased levels of one or none of the biomarkers. Conclusions CT-IGFBP-4 was independently associated with all-cause mortality in patients with AHF. Compared with single biomarkers, the combination of CT-IGFBP-4, NT-proBNP, and CRP improved the prediction of all-cause mortality in patients with AHF.Peer reviewe

Complex neuroimaging study of the proximal segment after rigid fixation and dynamic stabilization in patients with degenerative lumbar disease

Background. The development of the adjacent level syndrome and, as a consequence, adjacent segment degenerative disease are currently the most common complications of decompression and stabilization surgery with the development of segmental instability. The aim of the study. To conduct a comprehensive neuroimaging assessment of  the proximal adjacent segment after rigid fixation and dynamic stabilization in degenerative lumbar disease. Materials and methods. We conducted a prospective multicenter study of the results of surgical treatment of 274 patients with degenerative-dystrophic diseases of the lumbar spine, who underwent monosegmental decompression and stabilization surgery using the TLIF (transforaminal lumbar interbody fusion) technique and open transpedicular rigid fixation, as well as open hemilaminectomy with stabilization of the operated segments with nitinol rods. The study included radiography, diffusion-weighted magnetic resonance imaging and computed tomography (dualenergy mode) of intervertebral discs and isolated facet degeneration of the upper adjacent level. Results and discussion. Combination of the initial proximal segment degeneration in the form of  facet joints degeneration (density of cartilaginous plate  – 163.5 ± 14.2 HU, density of external facet – 709.35 ± 13.6 HU, density of internal facet – 578.1  ±  12.1  HU), Pfirrmann III, IV  grade degeneration of intervertebral disc and a measured diffusion coefficient of less than 1300 mm2/s cause high risks of developing adjacent segment degenerative disease, which regulates the use of monosegmental dynamic fixation with nitinol rods, or preventive rigid fixation of the adjacent segment. Conclusion. Using complex neuroimaging in the preoperative period makes it possible to predict the results of surgical treatment, take timely measures to prevent degenerative diseases of the adjacent segment, and to carry out dynamic monitoring of processes in the structures of the spinal motion segment

Comprehensive analysis of the results of surgical treatment of patients with degenerative diseases of the lumbar spine using rigid fixation systems

Introduction. According to the literature, the development of adjacent-level syndrome 10 years after posterior rigid stabilization is noted in 6.7–80 % of patients, of which 24 % require revision surgery.The aim: to conduct a comprehensive analysis of the results of surgical treatment of patients with degenerative diseases of the lumbar spine using rigid fixation systems.Materials and methods. A multicenter retrospective study of the results of surgical treatment of 268 patients with degenerative-dystrophic diseases of the lumbar spine, who underwent mono- or bisegmental decompression-stabilizing intervention with the implementation of the TLIF (Transforaminal Lumbar Interbody Fusion) technique and open transpedicular rigid fixation, was conducted. The study included radiography, MRI and CT (in 2-energy mode) of intervertebral discs and isolated facet degeneration of the upper adjacent level.Results and discussion. The combination of the initial degeneration of the adjacent spinal motion segment in the form of disc degeneration of grade III and higher according to Pfirrmann with threshold values of the density of the outer cartilaginous plate from 161.7 ± 18.8 to 164.8 ± 14.2 HU, the density of the outer facet – from 702.43 ± 12.3 to 713.65 ± 13.6 HU and the density of the inner facet – from 580.5 ± 11.6 to 582.1 ± 15.1 HU, as well as with signs of segmental instability of the adjacent segment can be considered as risk factors for the development of its degeneration. With the progression of degeneration of the upper intervertebral disc, revision interventions were performed within 12–60 months after surgery.Conclusion. Bisegmental stabilization with signs of initial degeneration in the intervertebral disc and facet joints in the upper segment has proven its clinical and instrumental effectiveness in the period of 36 months and reduces the risks of developing degenerative disease of the adjacent disc

NMR study of magnetic nanoparticles Ni@C

The 61Ni, 13C NMR spectra of carbon encapsulated nickel nanoparticles have been obtained. It has been shown that the cores of the particles consist of metallic nickel with face-centered cubic structure, nickel carbide Ni3C and carbon-nickel solid solution. The carbon shell of nanoparticles is a highly defective structure and close to an amorphous glassy-like carbon. © Published under licence by IOP Publishing Ltd.Ural Branch, Russian Academy of Sciences, UB RAS: 18-10-2-37.The study was performed within the state assignments of the Mikheev Institute of Metal Physics of the Ural Branch of the Russian Academy of Sciences: state program «Function» No АААА-А19-119012990095-0; state program «Magnit» No АААА-А18-118020290129-5 and state program «Alloys». The research also was supported by the project of the complex program of Ural Branch of Russian Academy of Sciences № 18-10-2-37

HARDWARE AND SOFTWARE SYSTEM FOR PSYCHOFUNCTIONAL STATE CORRECTION

Рассмотрены некоторые результаты разработки аппаратно-программной системы (АПС) электромагнитного излучения для коррекции стресса. Показано, что АПС с амплитудной модуляцией по псевдо-случайному закону при крайне низких уровнях мощности излучения позволяет корректировать психофункциональное состояние человека.Some results of the development of a hardware-software system (HSS) of electromagnetic radiation for stress correction are considered. It is shown that HSS with amplitude modulation according to a pseudo-random law at extremely low levels of radiation power makes it possible to correct the psycho-functional state of a person