-
Physical Review Letters Mar 2023Ta_{2}NiSe_{5} is an excitonic insulator candidate showing the semiconductor or semimetal-to-insulator (SI) transition below T_{c}=326 K. However, since a...
Ta_{2}NiSe_{5} is an excitonic insulator candidate showing the semiconductor or semimetal-to-insulator (SI) transition below T_{c}=326 K. However, since a structural transition accompanies the SI transition, deciphering the role of electronic and lattice degrees of freedom in driving the SI transition has remained controversial. Here, we investigate the photoexcited nonequilibrium state in Ta_{2}NiSe_{5} using pump-probe Raman and photoluminescence spectroscopies. The combined nonequilibrium spectroscopic measurements of the lattice and electronic states reveal the presence of a photoexcited metastable state where the insulating gap is suppressed, but the low-temperature structural distortion is preserved. We conclude that electron correlations play a vital role in the SI transition of Ta_{2}NiSe_{5}.
PubMed: 36962049
DOI: 10.1103/PhysRevLett.130.106904 -
Nano Letters Nov 2020We present a new approach to femtosecond direct laser writing lithography to pattern nanocavities in ferromagnetic thin films. To demonstrate the concept, we irradiated...
We present a new approach to femtosecond direct laser writing lithography to pattern nanocavities in ferromagnetic thin films. To demonstrate the concept, we irradiated 300 nm thin nickel films by single intense femtosecond laser pulses through glass substrate. Using a fluence above the ablation threshold, the process is destructive, leading to the formation of an ablation crater. By progressively lowering the laser fluence, the formation of closed spallation cavities below the ablation threshold is achieved. Systematic studies by the electron and optical interferometric microscopies, supported by molecular dynamics simulations, enabled us to gain an understanding of the thermo-mechanical spallation mechanism at the solid-molten interface. We achieved the fabrication of periodic arrangements of closed spallation nanocavities. Due to their topology, closed magnetic nanocavities can support unique couplings of multiple excitations (magnetic, optical, acoustic, spintronic). Thereby, they offer a unique physics playground for emerging fields in magnetism, magneto-photonic, and magneto-acoustic applications.
PubMed: 33074002
DOI: 10.1021/acs.nanolett.0c02574 -
Zhurnal Nevrologii I Psikhiatrii Imeni... 2024To determine the frequency of and among patients admitted to a24-hour emergency hospital.
OBJECTIVE
To determine the frequency of and among patients admitted to a24-hour emergency hospital.
MATERIAL AND METHODS
The study included 2887 patients with a traumatic history who were admitted to the hospital for emergency reasons. This principle of sampling allowed us to exclude a high concentration of studies of patients with chronic neurological diseases, the cause of which could be symptomatic Kimmerle's anomaly (KA). During the period 01.01.20 to 31.12.20, primary CT was performed on an emergency basis in 7348 patients. Of these, CT scans of the brain and cervical spine were performed in 2965 patients. Some patients (78 people) were excluded from the study due to the presence of cervical vertebral fractures and metal artifacts in the craniovertebral region.
RESULTS
The Ponticulus posticus was detected in 1162 (40.2%) patients, among them class 3 and 4 was detected in 27.7%, and class 2 ossification in 12.5%. This Ponticulus posticus was significantly more common (χ test, =0.0005) in men. The Ponticulus lateralis was identified in 231 patients (8%), among them 94 patients (3.3%) had complete ponticulus on both sides, 29 patients (1%) - on one side, and 108 patients (3.7%) - two-sided incomplete ponticulus. In patients with class 2-3-4, Ponticulus lateralis were detected significantly more often (χ test, <0.0001).
CONCLUSION
The cumulative incidence of KA was 42%, 17% of patients are carriers of a complete KA bridge, which is significantly higher than in the European or Asian regions. The data suggest that KA is not the result of ossification of the posterior atlanto-occipital membrane, since different classes of KA occur equally often at different ages. Further studies of KA are needed, including its occurrence in patients of the neurological department and its correlation with individual neurological syndromes to determine the need for surgical treatment in the population.
Topics: Male; Humans; Cervical Atlas; Hospitalization; Hospitals; Brain; Patients
PubMed: 38261287
DOI: 10.17116/jnevro202412401176 -
Kardiologiia Mar 2020To assess possibilities of contrast echocardiography with quantitative evaluation of myocardial perfusion in patients with previous Q-wave myocardial infarction.
OBJECTIVE
To assess possibilities of contrast echocardiography with quantitative evaluation of myocardial perfusion in patients with previous Q-wave myocardial infarction.
MATERIALS AND METHODS
We examined 15 men (42-72 years) with coronary artery disease and previous myocardial infarction, and pathological Q-wave in 2 or more ECG leads. Quantification of left ventricular (LV) myocardial perfusion was performed by calculating of the ultrasound signal tissue intensity from the LV myocardial segments during intravenous administration of the ultrasound contrast agent (SonoVue). The Tissue intensive curve (TIC) analysis was done in the end-diastolic period before and on the fourth cardiac cycle after applying the "flash". Changes in the intensity of myocardial perfusion (A4, dB) was estimated as the difference between the intensity values of the ultrasound signal in the myocardial segment during the period of filling the contrast bubbles on 4-th cardiac cycle and before applying the «flash». Measurements were performed in 16 segments of the LV. A contrast cardiac magnetic resonance imaging (contrast MRI) was performed in order to verify the LV scar. Fibrotic changes of 50% of myocardial wall or more were considered as signs of post-infarction scar.
RESULTS
The dynamics of perfusion and scar presence in 240 myocardial segments were evaluated. The median A4 was 1 dB (range, -20 to 10 dB). MRI revealed 82 of 240 segments with the large-focal scar. The effectiveness of the diagnostic test (quantitative contrast perfusion echocardiography with A4 assessment) to detect myocardial scar was investigated. ROC curve analysis showed good model quality, AUC=0,787 (0,730-0,837); sensitivity 82.9%; specificity 75.3%; p<0.01. The cut-off point for A4 was -1.
CONCLUSION
A new approach to quantitative contrast assessment of perfusion allows to identify perfusion disorders with high efficiency in patients with previous Q-wave myocardial infarction.
Topics: Adult; Aged; Contrast Media; Coronary Disease; Echocardiography; Humans; Male; Middle Aged; Myocardial Infarction; Myocardium; Sensitivity and Specificity
PubMed: 32345194
DOI: 10.18087/cardio.2020.2.n817 -
Archives of Razi Institute Nov 2021Nowadays, it is difficult to find a more complicated inflammatory disease of the abdominal organs in its pathogenesis than acute pancreatitis (AP). The application of...
Nowadays, it is difficult to find a more complicated inflammatory disease of the abdominal organs in its pathogenesis than acute pancreatitis (AP). The application of antimediatory drugs and antimetabolites is the most promising direction in the correction of inflammatory pathological processes. The study of possible applications of a new group of drugs (monoclonal antibodies) that may trigger inflammation is also of great interest. The present study aimed to study the effect of infliximab on the lethality, volume, and nature of pancreatic lesions in severe necrotizing ductal pancreatic necrosis. The study was conducted on female Wistar rats (n=30) of similar age in the weight range of 200-250g. All manipulations were performed under general anesthesia by intraperitoneal injection of zoletil at a dose of 60 mg/kg, as well as chloral hydrate at a dose of 125 mg/kg. Model of severe acute necrotizing pancreatitis was performed through the injection of 0.5 ml of a buffer solution containing a bile acid salt-sodium taurocholate introductory. The animals were divided into the following groups: Group A (n=6): normal values; Group B (n=6): the mortality study was conducted in acute destructive pancreatitis in a period of 24 h; Group C (n=6): the simulation of acute severe necrotic pancreatitis was performed in this group along with the study of the volume of pancreatic lesions for a period of 6 h from the moment of modeling; Group D (n=6): in this group, the effect of infliximab (at a dose of 60 mkg/kg) was studied on mortality in severe destructive pancreatitis for a period of 24 h from the moment of modeling; Group E (n=6): in this group, the effect of infliximab (at a dose of 120 mkg/kg) was studied on the volume of pancreatic lesions in severe destructive pancreatitis for a period of 6 h from the moment of modeling. During the assessment of pancreatic damage, the mean±SD volume of pancreatic lesions was determined to be 34.8%±1.2% in a period of 6 h after modeling. Assessment of pancreatic damage in group E and the protective effect of infliximab at a dose of 60 mg/kg showed that the total volume of the necrotic pancreatic lesion was determined to be 21.3%±1.4% after a period of 6 h from the moment of AP modeling. In the course of this study, it was revealed that the application of infliximab at a dose of 60 mcg/kg led to a pronounced positive effect on the pancreatic lesion, manifested by up to 50% decrease in mortality for one day in group D. Infliximab had a definite protective effect in AP, decreasing the volume of the injury, as well as the mortality rate by half for 24 h. Therapy with anti-tumor necrosis factor with infliximab could significantly reduce the volume of pancreatic lesions in severe forms of pancreatic necrosis, which contributed to a pronounced decrease in mortality for 1 day from the moment of pathology reproduction.
Topics: Animals; Female; Rats; Acute Disease; Infliximab; Pancreatitis, Acute Necrotizing; Rats, Wistar
PubMed: 35355779
DOI: 10.22092/ari.2021.355845.1726 -
Problemy Sotsial'noi Gigieny,... Nov 2021The article presents results of sociological survey of district psychiatrists that revealed actual difficulties and shortcomings in organization of medical care for...
The article presents results of sociological survey of district psychiatrists that revealed actual difficulties and shortcomings in organization of medical care for mental patients. The problem of personnel high workload, inopportuneness and inadequate completeness of necessary medical care of mental patients are explained by a number of difficulties in organization of functioning of psychoneurological organizations. They included not only shortage of personnel and unsatisfactory material technical support of mental institutions, but also incompleteness of normative legal support mental care organization. The physicians identified the following priority targets to be implemented in practice will eliminate a number of actual problems in district psychiatrist work: organization of procedure of interdepartmental interaction of various services (GUFSIN, the Ministry of Internal Affairs, social protection agencies, passport office), development and approval of procedure of dispensary observation of mental patients, approval of procedure of interaction with territorial polyclinics and full implementation of medical care standards for patients with mental disorders. The administration of neuropsychiatric organizations from position of systemic approach is a priority direction of improving quality of medical care for mental patients.
Topics: Humans; Mental Disorders; Organizations; Patient Care; Physicians; Psychiatry
PubMed: 34882338
DOI: 10.32687/0869-866X-2021-29-6-1584-1587 -
Kardiologiia Jan 2021Diagnosis of heart failure with preserved ejection fraction (HFpEF) is associated with certain difficulties since many patients with HFpEF have a slight left ventricular...
[The role of diastolic transthoracic stress echocardiography with incremental workload in the evaluation of heart failure with preserved ejection fraction: indications, methodology, interpretation. Expert consensus developed under the auspices of the National Medical Research Center of Cardiology,...
Diagnosis of heart failure with preserved ejection fraction (HFpEF) is associated with certain difficulties since many patients with HFpEF have a slight left ventricular diastolic dysfunction and normal filling pressure at rest. Diagnosis of HFpEF is improved by using diastolic transthoracic stress-echocardiography with dosed exercise (or diastolic stress test), which allows detection of increased filling pressure during the exercise. The present expert consensus explains the requirement for using the diastolic stress test in diagnosing HFpEF from clinical and pathophysiological standpoints; defines indications for the test with a description of its methodological aspects; and addresses issues of using the test in special patient groups.
Topics: Biomedical Research; Cardiology; Consensus; Echocardiography; Echocardiography, Stress; Exercise Test; Heart Failure; Humans; Russia; Stroke Volume; Ventricular Function, Left; Workload
PubMed: 33522468
DOI: 10.18087/cardio.2020.12.n1219 -
Parasitology Research Dec 2019Paranoplocephala omphalodes is a widespread parasite of voles. Low morphological variability within the genus Paranoplocephala has led to erroneous identification of P....
Paranoplocephala omphalodes is a widespread parasite of voles. Low morphological variability within the genus Paranoplocephala has led to erroneous identification of P. omphalodes a wide range of definitive hosts. The use of molecular methods in the earlier investigations has confirmed that P. omphalodes parasitizes four vole species in Europe. We studied the distribution of P. omphalodes in Russia and Kazakhstan using molecular tools. The study of 3248 individuals of 20 arvicoline species confirmed a wide distribution of P. omphalodes. Cestodes of this species were found in Microtus arvalis, M. levis, M. agrestis, Arvicola amphibius, and also in Chionomys gud. Analysis of the mitochondrial gene cox1 variability revealed a low haplotype diversity in P. omphalodes in Eurasia.
Topics: Animals; Arvicolinae; Cestoda; Cestode Infections; Genes, Mitochondrial; Host Specificity; Kazakhstan; Phylogeny; Rodent Diseases; Russia
PubMed: 31691856
DOI: 10.1007/s00436-019-06462-z -
The Science of the Total Environment Jun 2024The increasing popularity and recognition of citizen science approaches to monitor soil health have promoted the idea to assess soil microbial decomposition based on a...
The increasing popularity and recognition of citizen science approaches to monitor soil health have promoted the idea to assess soil microbial decomposition based on a standard litter sample - tea bags. Although tea bag initiatives are expanding across the world, the global datasets remain biased in regard to investigating regions and biomes. This study aimed to expand the tea bag initiative to European Russia, which remains a "white spot" on the tea bag index map. We also added urban soils into the analysis, which were underestimated previously. We compared the standard and local tea brands to explore possible adaptations of the standard approach to regions with limited access to standard tea brands. The established monitoring network included natural and urban sites in six vegetation zones along a 3000 km latitudinal gradient. There was a very close linear relationship (R = 0.94-0.98) in the mass loss of alternative and standard tea litter. The mass loss of green tea in soil along the latitudinal gradient showed an increasing trend from north to south. Variations in the microbial decomposition of green tea were mainly explained by the latitudinal gradient, with low soil temperature identified as key factors hampering decomposition. Mass loss of the more recalcitrant rooibos tea was mainly determined via land use, with decomposition rates on average 1.3 times higher in urban soils. This pattern was in line with higher soil temperatures and pH in urban sites compared to natural counterparts. The findings of our study could prove valuable in extending the tea bag network of soil decomposition assessment into broader territories, including urban areas. Additionally, they could facilitate the involvement of citizen science and complete the database for C cycle modeling depending on climatic conditions.
Topics: Russia; Environmental Monitoring; Soil; Tea; Soil Microbiology
PubMed: 38531454
DOI: 10.1016/j.scitotenv.2024.171881 -
Kardiologiia Feb 2021This thematic review focuses on recently proposed classification of stages in pronounced aortic stenosis based on the prevalence of extravalvular cardiac damage and its...
This thematic review focuses on recently proposed classification of stages in pronounced aortic stenosis based on the prevalence of extravalvular cardiac damage and its modified variant designed for asymptomatic patients. The review presents studies, which analyzed the predictive significance of the proposed classification. The use of this classification allows predicting the course of disease in patients with pronounced aortic stenosis in valve replacement. The classification is based on routinely used structural and functional echocardiographic signs with already proven predictive values with respect of adverse events in patients after aortic valve replacement. The review discusses limitations of the classification for pronounced aortic stenosis stages based on the prevalence of extravalvular cardiac damage.
Topics: Aortic Valve; Aortic Valve Stenosis; Heart Injuries; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Prevalence; Severity of Illness Index
PubMed: 33706692
DOI: 10.18087/cardio.2021.1.n1024