1,096 research outputs found
Resistivity of the (Gd1-xYx) in alloys as high temperatures two band model approach
Two-band model for the substitutionary binary alloy of different rare earth metals with relatively simple 4f multiplet structure placed within the transition metal host matrix was proposed and applied to (Gd1-xYx)2In.
The main interaction which causes the magnetic part of the resistivity was assumed in a form of stochastically distributed in space s— f interaction. The calculated high temperature spin disorder resistivity of (Gdx1- Yx )2In alloys reproduces well the experimental alloys data
Ultrafast photocurrents at the surface of the three-dimensional topological insulator
Topological insulators constitute a new and fascinating class of matter with
insulating bulk yet metallic surfaces that host highly mobile charge carriers
with spin-momentum locking. Remarkably, the direction and magnitude of surface
currents can be controlled with tailored light beams, but the underlying
mechanisms are not yet well understood. To directly resolve the "birth" of such
photocurrents we need to boost the time resolution to the scale of elementary
scattering events ( 10 fs). Here, we excite and measure photocurrents in
the three-dimensional model topological insulator
with a time resolution as short as 20 fs by sampling the concomitantly emitted
broadband THz electromagnetic field from 1 to 40 THz. Remarkably, the ultrafast
surface current response is dominated by a charge transfer along the Se-Bi
bonds. In contrast, photon-helicity-dependent photocurrents are found to have
orders of magnitude smaller magnitude than expected from generation scenarios
based on asymmetric depopulation of the Dirac cone. Our findings are also of
direct relevance for optoelectronic devices based on topological-insulator
surface currents
Jak pracować ze zdolnymi? Poradnik dla nauczycieli i rodziców
Publikacja powstała w ramach projektu "Opracowanie i wdrożenie kompleksowego systemu pracy z uczniem zdolnym"Publikacja współfinansowana przez Unię Europejską w ramach Europejskiego Funduszu Społeczneg
Role of progesterone receptor in luminal breast cancers
W praktyce klinicznej raki piersi luminalne B utożsamiane są z posiadającymi receptor estrogenowy, brakiem receptora HER2 oraz z brakiem lub niskimi poziomami receptora progesteronowego, ewentualnie z wysokim indeksem Ki67. Rzeczywista klasyfikacja molekularna raków piersi jest oparta o różnice w ekspresji całego panelu genów, nie tylko związanych z powyższymi receptorami, jednak dla celów klinicznych przyjęto uproszczony podział. Raki typu luminalnego B to w klasyfikacji klinicznej raki z ekspresją ER, jednak z gorszym rokowaniem. Coraz częściej w piśmiennictwie sugeruje się, że raki luminalne B stanowią grupę, w której aktywacja receptora estrogenowego nie jest kluczowa, a „siłą napędową” nowotworu są inne szlaki czynników wzrostu, związane na przykład z nabłonkowym czynnikiem wzrostu (EGF), insulinopodobnym czynnikiem wzrostu (IGF) czy czynnikiem wzrostu fibroblastów (FGF). Złożoności dodają liczne interakcje różnych czynników wzrostu z innymi receptorami. Przedstawione w tym artykule rozważania są podstawą do pełniejszego zrozumienia heterogenności raka piersi oraz są punktem wyjścia do dalszego pogłębiania wiedzy na ten temat.In clinical practice luminal B breast tumours are characterised by having estrogen receptor, the absence of HER2, and a lack or low levels of progesterone receptor, optionally with a high index of Ki67. However, the actual molecular classification of luminal cancers is based on differences in the expression of the whole panel of genes, not only those related to the above mentioned receptors. Luminal B cancers, are in fact, estrogen receptor positive tumours, but with worse outcome. Recently, it is frequently suggested that the luminal B tumours are a group in which the function of the estrogen receptor is not critical and other pathways are over-activated, which are related with growth factors: for example epithelial (EGF), insulin-like (IGF ) or fibroblast (FGF). Surprisingly there are also many interactions between various growth factors with estrogen receptor. This paper presents the heterogeneity of breast cancer. It is also a starting point for further research
Peripheral nerves electrostimulators. Technical Specifications
Admission The first successful attempt to use stimulants neuro modulation properties date back to the first half of the twentieth century. Due to the high technological limitations, the use of peripheral nerve electrostimulators the early eighties
XX century was relatively small and involved few patients treated primarily due to neuropathic pain and patients psychosurgical.
The development of modern batteries in the eighties of the twentieth century, standardization and implementation process to achieve consensus on the guidelines for operations in the field of functional neurosurgery, they contributed to intensified "Renaissance" functional neurosurgery.
Material and methods Articles in the EBSCO database were analyzed using the keywords: peripheral nerves, stimulation, electrostimulation, neurosurgery. Furthermore, neural searched betting sites in terms of the technical aspects of this equipment. Available literature was subjectively selected. Then searched the latest version of each article.
Results Offered different tools offered technical specifications. Technological developments have allowed the convenience to use devices, min. by increasing control by the user or representative of the operation of the pacemaker.
Conclusions The development of technology and neuroscience neurostymulatorów resulted in the development of many available on the market. However, more research is needed to determine the exact parameters of stimulation, which would get the largest size stimulation effect while minimizing adverse effects
Angiosarcoma of the lungs, liver, and bones in a 27-year-old male patient
Angiosarcoma is a rare (from 1% to 2% of all soft tissue sarcomas), highly aggressive endothelial tumor that may affect any organ. The prognosis for the disease is poor, particularly if it is metastatic by the time of diagnosis. The etiology is unclear; however, there are definite risk factors including chronic lymphedema, radiation therapy, familial syndromes, and exposure to environmental chemical toxins and foreign bodies. Although the final diagnosis is histopathological, radiological tools such as ultrasound, CT, and MRI are still necessary to determine the stage of cancer. Treatment includes surgery, chemotherapy, and radiation therapy. Chemotherapy is the main treatment strategy for metastatic angiosarcoma, however, the toxicity level of frequently used agents is high. The research focuses on targeted medicines and immunotherapy as potential therapeutic options. We present a case of angiosarcoma in a young man without chronic illnesses with metastatic spread to the lungs, liver, and bones at the time of diagnosi
In vivo data: treatment with the F11R/JAM-A peptide 4D decreases mortality and reduces the generation of atherosclerotic plaques in ApoE-deficient mice
The data in this article focus on the F11 Receptor (F11R/JAM-A; Junctional Adhesion Molecule-A; JAM-A, F11R), a cell adhesion protein constitutively expressed on the membrane surface of circulating platelets and localized within the tight junctions of healthy endothelial cells (ECs). Previous reports have shown that F11R/JAM-A plays a critical role in the adhesion of platelets to an inflamed endothelium due to its’ pathological expression on the luminal surface of the cytokine-inflamed endothelium. Since platelet adhesion to an inflamed endothelium is an early step in the development of atherosclerotic plaque formation, and with time, resulting in heart attacks and stroke, we conducted a long-term, study utilizing the atherosclerosis-prone ApoE-/- mice to attempt a blockade of the formation of atherosclerotic plaques by preventing the adhesion of platelets to the inflamed vasculature in vivo. Utilizing a nonhydrolyzable peptide derived from an amino acid sequence of F11R/JAM-A, peptide 4D, we have shown in culture that the adhesion of platelets to the inflamed endothelial cells could be blocked by peptide 4D. The present data demonstrate the positive health benefits of chronic peptide 4D administration to the atherosclerosis-prone ApoE-/- mice, and provides new information for potential use of this F11R derived peptide in the prevention of atherosclerosis. The data presented in this article provide further experimental support for the study presented in Babinska et al., Atherosclerosis 284 (2019) 92-101
Glomangioma in the hand: diagnosis, treatment, and challenges
Introduction. In this paper, we have analysed all hand glomangioma cases referred to our clinic in the context of symptoms, time to diagnosis, and the role of surgical resection of the lesion.
Material and methods. We have collected the following data: the presence of risk factors, manifestation, time to diagnosis, the treatment applied, and follow-up of patients.
Results. We have collected medical records from six patients, three males and three females. The median age was 45 (IQR: 29.5–65.75). The main symptom in all patients was severe pain and tenderness. The first-choice physician(s) were: general practitioners, general surgeons, and neurologists. The median time to diagnosis was 7 (IQR: 5–10) years. The main complaint of our patients was severe pain — 9 (IQR: 9–10) on the VAS scale, which was significantly alleviated after surgical treatment — 0 (IQR: 0–0; p = 0.043).
Conclusions. Extremely long times to final diagnosis, and excellent outcomes of surgical treatment, highlight the necessity of raising awareness of glomangiomas among clinicians
Can we identify non-stationary dynamics of trial-to-trial variability?"
Identifying sources of the apparent variability in non-stationary scenarios is a fundamental problem in many biological data analysis settings. For instance, neurophysiological responses to the same task often vary from each repetition of the same experiment (trial) to the next. The origin and functional role of this observed variability is one of the fundamental questions in neuroscience. The nature of such trial-to-trial dynamics however remains largely elusive to current data analysis approaches. A range of strategies have been proposed in modalities such as electro-encephalography but gaining a fundamental insight into latent sources of trial-to-trial variability in neural recordings is still a major challenge. In this paper, we present a proof-of-concept study to the analysis of trial-to-trial variability dynamics founded on non-autonomous dynamical systems. At this initial stage, we evaluate the capacity of a simple statistic based on the behaviour of trajectories in classification settings, the trajectory coherence, in order to identify trial-to-trial dynamics. First, we derive the conditions leading to observable changes in datasets generated by a compact dynamical system (the Duffing equation). This canonical system plays the role of a ubiquitous model of non-stationary supervised classification problems. Second, we estimate the coherence of class-trajectories in empirically reconstructed space of system states. We show how this analysis can discern variations attributable to non-autonomous deterministic processes from stochastic fluctuations. The analyses are benchmarked using simulated and two different real datasets which have been shown to exhibit attractor dynamics. As an illustrative example, we focused on the analysis of the rat's frontal cortex ensemble dynamics during a decision-making task. Results suggest that, in line with recent hypotheses, rather than internal noise, it is the deterministic trend which most likely underlies the observed trial-to-trial variability. Thus, the empirical tool developed within this study potentially allows us to infer the source of variability in in-vivo neural recordings
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