Benchmarking a semiclassical impurity solver for dynamical-mean-field theory: self-energies and magnetic transitions of the single-orbital Hubbard model

An investigation is presented of the utility of semiclassical approximations for solving the quantum-impurity problems arising in the dynamical-mean-field approach to the correlated-electron models. The method is based on performing a exact numerical integral over the zero-Matsubara-frequency component of the spin part of a continuous Hubbard-Stratonovich field, along with a spin-field-dependent steepest descents treatment of the charge part. We test this method by applying it to one or two site approximations to the single band Hubbard model with different band structures, and comparing the results to quantum Monte-Carlo and simplified exact diagonalization calculations. The resulting electron self-energies, densities of states and magnetic transition temperatures show reasonable agreement with the quantum Monte-Carlo simulation over wide parameter ranges, suggesting that the semiclassical method is useful for obtaining a reasonable picture of the physics in situations where other techniques are too expensive.Comment: 14 pages, 15 figure

Інвестиційна політика як один з пріорітетних шляхів розвитку економіки регіонів

В сучасних умовах спаду економічного розвитку регіонів важливу роль відіграють пошуки нових напрямів в регіональній реформі. На сучасному етапі дуже мало приділяється уваги новаторським питанням. Таким чином, розвиток інноваційної діяльності суб’єктів господарювання регіону може бути використаний як дієвий чинник економічного оздоровлення

The Classification of Weld Seam Defects for Quantitative Analysis by means of Ultrasonic Testing

The paper describes effective quality assessment of spent nuclear fuel storage cask. The ultrasonic testing method is considered. The classification of possible defects with corresponding dimensions limits is proposed. The database of defects of the spent nuclear fuel storage cask was created in compliance with the nuclear energy industry regulatory documents

Podoplanin immunopositive lymphatic vessels at the implant interface in a rat model of osteoporotic fractures

Insertion of bone substitution materials accelerates healing of osteoporotic fractures. Biodegradable materials are preferred for application in osteoporotic patients to avoid a second surgery for implant replacement. Degraded implant fragments are often absorbed by macrophages that are removed from the fracture side via passage through veins or lymphatic vessels. We investigated if lymphatic vessels occur in osteoporotic bone defects and whether they are regulated by the use of different materials. To address this issue osteoporosis was induced in rats using the classical method of bilateral ovariectomy and additional calcium and vitamin deficient diet. In addition, wedge-shaped defects of 3, 4, or 5 mm were generated in the distal metaphyseal area of femur via osteotomy. The 4 mm defects were subsequently used for implantation studies where bone substitution materials of calcium phosphate cement, composites of collagen and silica, and iron foams with interconnecting pores were inserted. Different materials were partly additionally functionalized by strontium or bisphosphonate whose positive effects in osteoporosis treatment are well known. The lymphatic vessels were identified by immunohistochemistry using an antibody against podoplanin. Podoplanin immunopositive lymphatic vessels were detected in the granulation tissue filling the fracture gap, surrounding the implant and growing into the iron foam through its interconnected pores. Significant more lymphatic capillaries were counted at the implant interface of composite, strontium and bisphosphonate functionalized iron foam. A significant increase was also observed in the number of lymphatics situated in the pores of strontium coated iron foam. In conclusion, our results indicate the occurrence of lymphatic vessels in osteoporotic bone. Our results show that lymphatic vessels are localized at the implant interface and in the fracture gap where they might be involved in the removal of lymphocytes, macrophages, debris and the implants degradation products. Therefore the lymphatic vessels are involved in implant integration and fracture healing

Ability of 18F-FDG Positron Emission Tomography Radiomics and Machine Learning in Predicting KRAS Mutation Status in Therapy-Naive Lung Adenocarcinoma.

OBJECTIVE Considering the essential role of KRAS mutation in NSCLC and the limited experience of PET radiomic features in KRAS mutation, a prediction model was built in our current analysis. Our model aims to evaluate the status of KRAS mutants in lung adenocarcinoma by combining PET radiomics and machine learning. METHOD Patients were retrospectively selected from our database and screened from the NSCLC radiogenomic dataset from TCIA. The dataset was randomly divided into three subgroups. Two open-source software programs, 3D Slicer and Python, were used to segment lung tumours and extract radiomic features from 18F-FDG-PET images. Feature selection was performed by the Mann-Whitney U test, Spearman's rank correlation coefficient, and RFE. Logistic regression was used to build the prediction models. AUCs from ROCs were used to compare the predictive abilities of the models. Calibration plots were obtained to examine the agreements of observed and predictive values in the validation and testing groups. DCA curves were performed to check the clinical impact of the best model. Finally, a nomogram was obtained to present the selected model. RESULTS One hundred and nineteen patients with lung adenocarcinoma were included in our study. The whole group was divided into three datasets: a training set (n = 96), a validation set (n = 11), and a testing set (n = 12). In total, 1781 radiomic features were extracted from PET images. One hundred sixty-three predictive models were established according to each original feature group and their combinations. After model comparison and selection, one model, including wHLH_fo_IR, wHLH_glrlm_SRHGLE, wHLH_glszm_SAHGLE, and smoking habits, was validated with the highest predictive value. The model obtained AUCs of 0.731 (95% CI: 0.619~0.843), 0.750 (95% CI: 0.248~1.000), and 0.750 (95% CI: 0.448~1.000) in the training set, the validation set and the testing set, respectively. Results from calibration plots in validation and testing groups indicated that there was no departure between observed and predictive values in the two datasets (p = 0.377 and 0.861, respectively). CONCLUSIONS Our model combining 18F-FDG-PET radiomics and machine learning indicated a good predictive ability of KRAS status in lung adenocarcinoma. It may be a helpful non-invasive method to screen the KRAS mutation status of heterogenous lung adenocarcinoma before selected biopsy sampling

Oxidative functionalization mechanisms in organic synthesis using fenton reaction systems

We argued an oxywater-oxene concept for hydrogen peroxide transformation in Fenton reaction systems and used this interpretation for mechanisms explanation of hydroperoxide monooxygen oxidative functionalization processes (alkane and arene hydroxylation, alkene epoxidation, Baeyer-Villiger ketone oxidation to ester, organonitrogen compounds N-oxidation and organosulfur compounds S-oxidation) and dioxygen alkene and alkadiene functionalization processes (synthesis of hydroperoxides and cyclic peroxides)

Inpatient or day clinic treatment? Results of a multi-site-study

Objective: This naturalistic study aimed to identify criteria which are of relevance for making a decision as to whether inpatient or day hospital treatment is indicated

Efficacy, safety and quality of life in a multicenter, randomized, placebo-controlled trial of low-dose peanut oral immunotherapy in children with peanut allergy

BACKGROUND: Only 2 small placebo-controlled trials on peanut oral immunotherapy (OIT) have been published. OBJECTIVE: We examined the efficacy, safety, immunologic parameters, quality of life (QOL), and burden of treatment (BOT) of low-dose peanut OIT in a multicenter, double-blind, randomized placebo-controlled trial. METHODS: A total of 62 children aged 3 to 17 years with IgE-mediated, challenge-proven peanut allergy were randomized (1:1) to receive peanut OIT with a maintenance dose of 125 to 250 mg peanut protein or placebo. The primary outcome was the proportion of children tolerating 300 mg or more peanut protein at oral food challenge (OFC) after 16 months of OIT. We measured the occurrence of adverse events (AEs), immunologic changes, and QOL before and after OIT and BOT during OIT. RESULTS: Twenty-three of 31 (74.2%) children of the active group tolerated at least 300 mg peanut protein at final OFC compared with 5 of 31 (16.1%) in the placebo group (P < .001). Thirteen of 31 (41.9%) children of the active versus 1 of 31 (3.2%) of the placebo group tolerated the highest dose of 4.5 g peanut protein at final OFC (P < .001). There was no significant difference between the groups in the occurrence of AE-related dropouts or in the number, severity, and treatment of objective AEs. In the peanut-OIT group, we noted a significant reduction in peanut-specific IL-4, IL-5, IL-10, and IL-2 production by PBMCs compared with the placebo group, as well as a significant increase in peanut-specific IgG4 levels and a significant improvement in QOL; 86% of children evaluated the BOT positively. DISCUSSION: Low-dose OIT is a promising, effective, and safe treatment option for peanut-allergic children, leading to improvement in QOL, a low BOT, and immunologic changes showing tolerance development