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The recently proposed concept of a Hund's metal--a metal in which electron correlations are driven by Hund's rule coupling-can be used to explain the exotic magnetic and electronic behaviour of strongly correlated electron systems of multi-orbital metallic materials. Tuning the abundance of parameters that determine these materials is, however, experimentally challenging. Here, we show that the basic constituent of a Hund's metal--a Hund's impurity--can be realized using a single iron atom adsorbed on a platinum surface, a system that comprises a magnetic moment in the presence of strong charge fluctuations. The magnetic properties can be controlled by using the tip of a scanning tunnelling microscope to change the binding site and degree of hydrogenation of the 3d transition-metal atom. We are able to experimentally explore a regime of four almost degenerate energy scales (Zeeman energy, temperature, Kondo temperature and magnetic anisotropy) and probe the magnetic excitations with the microscope tip. The regime of our Hund's impurity can be tuned from an emergent magnetic moment to a multi-orbital Kondo state, and the system could be used to test predictions of advanced many-body theories for non-Fermi liquids in quantum magnets or unconventional superconductors.
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We show through first-principles nuclear structure calculations that the special nature of the strong nuclear force determines highly regular patterns heretofore unrecognized in nuclei that can be tied to an emergent approximate symmetry. This symmetry is ubiquitous and mathematically tracks with a symplectic symmetry group. This, in turn, has important implications for understanding the physics of nuclei: we find that nuclei are made of only a few equilibrium shapes, deformed or not, with associated vibrations and rotations. It also opens the path for ab initio large-scale modeling of open-shell intermediate-mass nuclei without the need for renormalized interactions and effective charges.
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Strokes secondary to acute internal carotid artery (ICA) occlusion are associated with an extremely poor prognosis. The best treatment approach in this setting is still unknown. The aim of our study was to evaluate the efficacy, safety, and outcomes of emergent surgical revascularization of acute extracranial ICA occlusion in patients with minor to severe ischemic stroke. METHODS: A retrospective analysis was performed using prospectively collected data of consecutive patients who underwent carotid thromboendarterectomy for symptomatic acute ICA occlusion during the period from January 2013 to December 2015. Primary outcomes were disability at 90 days assessed by the modified Rankin Scale (mRS) and neurological deficit at discharge assessed using the National Institute of Health Stroke Scale (NIHSS). Secondary outcomes were the recanalization rate, 30-day overall mortality, and any intracerebral bleeding. RESULTS: During the study period, a total of 6 patients (5 men and 1 woman) with a median age of 64 years (range: 58-84 years) underwent emergent reconstruction for acute symptomatic ICA occlusion within a median of 5.4 hours (range: 2.9-12.0 hours) after symptoms onset. The median presenting NIHSS score was 10.5 points (range: 4-21). Before surgery, 4 patients (66.7%) had been treated by systemic recombinant tissue plasminogen activator lysis. The median time interval between initiation of intravenous thrombolysis and carotid thromboendarterectomy was 117.5 minutes (range: 65-140 minutes). Patency of the ICA was achieved in all patients. On discharge, the median NIHSS score was 2 points (range: 0-11 points). There was no postoperative intracerebral hemorrhage and zero 30-day mortality rate. At 3 months, 5 patients (83.3%) had a good clinical outcome (mRS ≤ 2). CONCLUSION: Patients presenting with minor to severe ischemic stroke syndromes due to isolated extracranial ICA occlusion may benefit from emergent carotid revascularization. Thorough preoperative neuroimaging is essential to aid in selecting eligible candidates for acute surgical intervention.
- Klíčová slova
- acute ischemic stroke, carotid artery occlusion, carotid endarterectomy, internal carotid artery, outcome, penumbra,
- MeSH
- akutní nemoc MeSH
- arteria carotis interna diagnostické zobrazování patofyziologie chirurgie MeSH
- čas zasáhnout při rozvinutí nemoci MeSH
- časové faktory MeSH
- cévní mozková příhoda diagnóza etiologie mortalita patofyziologie MeSH
- CT angiografie MeSH
- digitální subtrakční angiografie MeSH
- ischemie mozku diagnóza etiologie mortalita patofyziologie MeSH
- karotická endarterektomie * škodlivé účinky mortalita MeSH
- lidé středního věku MeSH
- lidé MeSH
- mozková angiografie metody MeSH
- mozkový krevní oběh MeSH
- náhlé příhody MeSH
- perfuzní zobrazování metody MeSH
- posuzování pracovní neschopnosti MeSH
- průchodnost cév MeSH
- retrospektivní studie MeSH
- rizikové faktory MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- stenóza arteria carotis komplikace diagnostické zobrazování mortalita chirurgie MeSH
- stupeň závažnosti nemoci MeSH
- trombolytická terapie MeSH
- výběr pacientů MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Domestic and municipal sewage contains various pathogenic or potentially pathogenic microorganisms which, depending on species concentration, pose a potential risk to human health and whose presence must therefore be reduced in the course of wastewater treatment. The removal of microbiological pollution is seldom a primary target for constructed treatment wetlands (CWs). However, wetlands are known to act as excellent biofilters through a complex of physical, chemical and biological factors which all participate in the reduction of the number of bacteria. Measurement of human pathogenic organisms in untreated and treated wastewater is expensive and technically challenging. Consequently, environmental engineers have sought indicator organisms that are (1) easy to monitor and (2) correlate with population of pathogenic organisms. The most frequently used indicators are total coliforms, fecal coliforms, fecal streptococci and Escherichia coli. The literature survey of 60 constructed wetlands with emergent vegetation around the world revealed that removal of total and fecal coliforms in constructed wetlands with emergent macrophytes is high, usually 95 to > 99% while removal of fecal streptococci is lower, usually 80-95%. Because bacterial removal efficiency is a function of inflow bacteria number, the high removal effects are achieved for untreated or mechanically pretreated wastewater. Therefore, the outflow numbers of bacteria are more important. For TC and FC the outflow concentrations are usually in the range of 10(2) to 10(5) CFU/ 100 ml while for FS the range is between 10(2) and 10(4) CFU/ 100 ml. Results from operating systems suggest that enteric microbe removal efficiency in CWs with emergent macrophytes is primarily influenced by hydraulic loading rate (HLR) and the resultant hydraulic residence time (HRT) and the presence of vegetation. Removal of enteric bacteria follows approximately a first-order relationship.
- MeSH
- biodegradace MeSH
- ekosystém * MeSH
- Enterobacteriaceae izolace a purifikace MeSH
- Escherichia coli izolace a purifikace MeSH
- filtrace MeSH
- mikrobiologie vody MeSH
- monitorování životního prostředí MeSH
- odpad tekutý - odstraňování metody MeSH
- pohyb vody MeSH
- rostliny MeSH
- Streptococcus izolace a purifikace MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Non-independent interactions among predators can have important consequences for the structure and dynamics of ecological communities by enhancing or reducing prey mortality rate through, e.g., predator facilitation or interference. The multiplicative risk model, traditionally used to detect these emergent multiple predator effects (MPEs), is biased because it assumes linear functional response (FR) and no prey depletion. To rectify these biases, two approaches based on FR modelling have recently been proposed: the direct FR approach and the population-dynamic approach. Here we compare the strengths, limitations and predictions of the three approaches using simulated data sets. We found that the predictions of the direct FR and the multiplicative risk models are very similar and underestimate predation rates when prey density is high or prey depletion is substantial. As a consequence, these two approaches often fail in detecting risk reduction. Finally, parameters estimated with the direct FR approach lack mechanistic interpretation, which limits the understanding of the mechanisms driving multiple predator interactions and potential extension of this approach to more complex food webs. We thus strongly recommend using the population-dynamic approach because it is robust, precise, and provides a scalable mechanistic framework to detect and quantify MPEs.
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Despite all the gains that have been achieved with endovascular mechanical thrombectomy revascularization and intravenous thrombolysis logistics since 2015, there is still a subgroup of patients with salvageable brain tissue for whom persistent emergent large vessel occlusion portends a catastrophic outcome. OBJECTIVE: To test the safety and efficacy of emergent microsurgical intervention in patients with acute ischemic stroke and symptomatic middle cerebral artery occlusion after failure of mechanical thrombectomy. METHODS: A prospective two-center cohort study was conducted. Patients with acute ischemic stroke and middle cerebral artery occlusion for whom recanalization failed at center 1 were randomly allocated to the microsurgical intervention group (MSIG) or control group 1 (CG1). All similar patients at center 2 were included in the control group 2 (CG2) with no surgical intervention. Microsurgical embolectomy and/or extracranial-intracranial bypass was performed in all MSIG patients at center 1. RESULTS: A total of 47 patients were enrolled in the study: 22 at center 1 (12 allocated to the MSIG and 10 to the CG1) and 25 patients at center 2 (CG2). MSIG group patients showed a better clinical outcome on day 90 after the stroke, where a modified Rankin Scale score of 0-2 was reached in 7 (58.3%) of 12 patients compared with 1/10 (10.0%) patients in the CG1 and 3/12 (12.0%) in the CG2. CONCLUSIONS: This study demonstrated the potential for existing microsurgical techniques to provide good outcomes in 58% of microsurgically treated patients as a third-tier option.
- Klíčová slova
- Stroke, Thrombectomy, Thrombolysis,
- MeSH
- arteria carotis interna chirurgie MeSH
- cévní mozková příhoda * diagnostické zobrazování chirurgie MeSH
- endovaskulární výkony * metody MeSH
- infarkt arteria cerebri media MeSH
- ischemická cévní mozková příhoda * MeSH
- ischemie mozku * diagnostické zobrazování chirurgie MeSH
- kohortové studie MeSH
- lidé MeSH
- prospektivní studie MeSH
- retrospektivní studie MeSH
- trombektomie škodlivé účinky metody MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- randomizované kontrolované studie MeSH
Emerging environmental contaminants, such as medicine waste, are of great concern to the scientific community and to the local environmental and health departments because of their potential long-term effects and ecotoxicological risk. Besides the prolonged use of medicines for the development of modern society, the elucidation of their effect on the ecosystem is relatively recent. Medicine waste and its metabolites can, for instance, cause alterations in microbial dynamics and disturb fish behavior. Bioremediation is an efficient and eco-friendly technology that appears as a suitable alternative to conventional methods of water waste and sludge treatment and has the capacity to remove or reduce the presence of emerging contaminants. Thus, this review has the objective of compiling information on environmental contamination by common medicines and their microbial biodegradation, focusing on five therapeutic classes: analgesics, antibiotics, antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs), and contraceptives. Their effects in the environment will also be analyzed, as well as the possible routes of degradation by microorganisms.
- MeSH
- biodegradace MeSH
- ekosystém * MeSH
- odpadní vody * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- odpadní vody * MeSH
BACKGROUND: Acute symptomatic occlusion of extracranial internal carotid artery (eICA) can lead to a critical and potentially devastating stroke associated with high morbidity and mortality. Optimal treatment remains unclear. We analyzed our institutional experience with emergent surgical recanalization of acutely occluded eICA. METHODS: Retrospective analysis of hospital records, surgical reports, imaging studies and outpatient records. Final outcome was assessed according to modified Rankin Scale (mRS). RESULTS: Between January 2010 and September 2013, 22 patients underwent emergent surgical recanalization. There were 17 men and five women, mean age 65.4 years (range 37-85). Mean admission National Institute of Health Stroke Scale (NIHSS) was 12 (range 6-21). All patients had evidence of salvageable penumbra on perfusion computed tomography. Tandem intracranial lesion was present in nine patients. Surgical recanalization was successful in 16 patients (72.7 %). Twenty-four hours after surgery, 17 patients (77.2 %) improved by a minimum of 1 point on NIHSS, 14 patients (63.6 %) improved by three and more points; two patients deteriorated by two and five points, the latter treated initially with systemic thrombolysis due to intracranial hemorrhage. No other intracranial hematoma was observed. During 30 days following surgery, two patients died (9 % mortality rate) due to severity of initial stroke. On discharge, four patients were classified as mRS 0, five patients as mRS 1, five patients as mRS 2 and six patients as mRS 4. Favorable recovery (mRS 0-2) was achieved in 14 patients (63.6 %). No change in mRS was observed at three months. CONCLUSIONS: Our results suggest that emergent surgical desobliteration of occluded eICA can lead to favorable recovery in a majority of patients. Patient selection based on penumbra imaging is crucial. Given the popularity and simplicity of carotid endarterectomy, the procedure should by no means be abandoned in the treatment of acute eICA occlusion.
- MeSH
- arteria carotis interna diagnostické zobrazování chirurgie MeSH
- arteriální okluzní nemoci diagnostické zobrazování mortalita chirurgie MeSH
- dospělí MeSH
- hodnocení výsledků zdravotní péče * MeSH
- karotická endarterektomie metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci arterie carotis diagnostické zobrazování mortalita chirurgie MeSH
- radiografie MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- bradykardie MeSH
- duševní poruchy farmakoterapie MeSH
- extrapyramidové dráhy MeSH
- gastrointestinální nemoci MeSH
- hyperkineze MeSH
- hypotenze MeSH
- kognitivní poruchy MeSH
- kožní manifestace MeSH
- lidé MeSH
- nežádoucí účinky léčiv * MeSH
- pocení MeSH
- pohybové poruchy MeSH
- poruchy močení MeSH
- poruchy zraku MeSH
- salivace MeSH
- sexuální chování MeSH
- spasmus MeSH
- tachykardie MeSH
- tělesná hmotnost MeSH
- tremor MeSH
- únava MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- císařský řez metody MeSH
- hysterektomie metody MeSH
- lidé MeSH
- nemoci placenty * MeSH
- placenta accreta * chirurgie MeSH
- retrospektivní studie MeSH
- těhotenství MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH