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The proton is one of the main building blocks of all visible matter in the Universe1. Among its intrinsic properties are its electric charge, mass and spin2. These properties emerge from the complex dynamics of its fundamental constituents-quarks and gluons-described by the theory of quantum chromodynamics3-5. The electric charge and spin of protons, which are shared among the quarks, have been investigated previously using electron scattering2. An example is the highly precise measurement of the electric charge radius of the proton6. By contrast, little is known about the inner mass density of the proton, which is dominated by the energy carried by gluons. Gluons are hard to access using electron scattering because they do not carry an electromagnetic charge. Here we investigated the gravitational density of gluons using a small colour dipole, through the threshold photoproduction of the J/ψ particle. We determined the gluonic gravitational form factors of the proton7,8 from our measurement. We used a variety of models9-11 and determined, in all cases, a mass radius that is notably smaller than the electric charge radius. In some, but not all cases, depending on the model, the determined radius agrees well with first-principle predictions from lattice quantum chromodynamics12. This work paves the way for a deeper understanding of the salient role of gluons in providing gravitational mass to visible matter.
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In two experiments, we systematically investigated the reasons why people retained certain autobiographical events in their memory, as well as the properties of those events and their predicted memorability. The first experiment used three methods (word-cued, free-recalled, and "memorable, interesting, and/or important") to retrieve event memories, and examined memories from three different time-frames: very recent (within past 7 days), recent (past 2 weeks and 6 months), and older events (at least one year). In addition, data were also collected for an important transitional event recently experienced by all participants ("starting university"). The results revealed that people had access to three types of event memories: memories for life transitions, memories for older distinctive events, and memories for recent mundane events. Participants reported remembering events that were distinctive, first-time experiences, emotionally impactful, or simply because they were recent. They also predicted that older events would be more resistant to forgetting than very recent and recent events. The second experiment examined participants' memorable and forgettable events, and found that memorable events tended to be older, while forgettable events were more likely to be recent. These findings suggested that many retrievable memorable autobiographical memories were neither important nor transitional in nature. The studies contribute to our understanding of people's metamnemonic knowledge about their autobiographical memories.
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Memória Episódica , Rememoração Mental , Metacognição , Humanos , Rememoração Mental/fisiologia , Adulto , Adulto Jovem , Metacognição/fisiologia , Feminino , Masculino , Acontecimentos que Mudam a Vida , Fatores de TempoRESUMO
The quark and gluon structure of the proton has been under intense experimental and theoretical investigation for five decades. Even for the distributions of the well-studied valence quarks, challenges such as the value of the down quark to up quark ratio at high fractional momenta remain. Much of the sea of quark-antiquark pairs emerges from the splitting of gluons and is well described by perturbative evolution in quantum chromodynamics. However, experiments confirm that there is a non-perturbative component to the sea that is not well understood and hitherto has been difficult to calculate with ab initio non-perturbative methods. This non-perturbative structure shows up, perhaps most directly, in the flavor dependence of the sea antiquark distributions. While some of the general trends can be reproduced by models, there are features of the data that do not seem to be well described. This article discusses the experimental situation, the status of calculations and models, and the directions where these studies will progress in the near future.
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Backward-angle meson electroproduction above the resonance region, which was previously ignored, is anticipated to offer unique access to the three quark plus sea component of the nucleon wave function. In this Letter, we present the first complete separation of the four electromagnetic structure functions above the resonance region in exclusive ω electroproduction off the proton, epâe^{'}pω, at central Q^{2} values of 1.60, 2.45 GeV^{2}, at W=2.21 GeV. The results of our pioneering -u≈-u_{min} study demonstrate the existence of a unanticipated backward-angle cross section peak and the feasibility of full L/T/LT/TT separations in this never explored kinematic territory. At Q^{2}=2.45 GeV^{2}, the observed dominance of σ_{T} over σ_{L}, is qualitatively consistent with the collinear QCD description in the near-backward regime, in which the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes: universal nonperturbative objects only accessible through backward-angle kinematics.
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Sepsis is a life-threatening condition caused by a dysregulated host response to infection. Over the last decades, the approach to sepsis is evolving dramatically, mainly as a result of a rapid increase in the knowledge of its epidemiology, physiopathology, and management. In this context, the new international criteria and definition for sepsis, The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3), were introduced in 2016. The criteria were established consensually by the Task Force which consisted of experts from the Society of Critical Care Medicine and the European Society of Intensive Care Medicine. The main goal is the expansion of awareness of the professional public about this medical condition with a high fatality rate, particularly when not diagnosed and treated early. Sepsis-3 should also serve as a benchmark for future preclinical and clinical research, development of new diagnostic methods, and the terapy of patients with sepsis and septic shock.
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Sepse , Terminologia como Assunto , Comitês Consultivos , Consenso , Humanos , Choque SépticoRESUMO
Diagnostic imaging is crucial in the work-up of acute aortic diseases. Current imaging algorithms enable radiologists differentiating the various entities with subsequent clinically relevant treatment options. Within this educational overview we focus on non-traumatic acute aortic disease. Recent developments of cross sectional imaging are summarized. As for acute aortic disease, we discuss dissections, intramural hematoma, penetrating aortic ulcer, and aortitis. Current treatment options are presented.
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Angiografia/métodos , Doenças da Aorta/diagnóstico , Doenças da Aorta/terapia , Angiografia por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X/métodos , Doença Aguda , Aorta , Diagnóstico Diferencial , Medicina Baseada em Evidências , Humanos , PrognósticoRESUMO
Etruria contained one of the great early urban civilisations in the Italian peninsula during the first millennium BC, much studied from a cultural, humanities-based, perspective, but relatively little with scientific data, and rarely in combination. We have addressed the unusual location of twenty inhumations found in the sacred heart of the Etruscan city of Tarquinia, focusing on six of these as illustrative, contrasting with the typical contemporary cremations found in cemeteries on the edge of the city. The cultural evidence suggests that the six skeletons were also distinctive in their ritualization and memorialisation. Focusing on the six, as a representative sample, the scientific evidence of osteoarchaeology, isotopic compositions, and ancient DNA has established that these appear to show mobility, diversity and violence through an integrated bioarchaeological approach. The combination of multiple lines of evidence makes major strides towards a deeper understanding of the role of these extraordinary individuals in the life of the early city of Etruria.
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Arqueologia , Itália , Humanos , História Antiga , Masculino , DNA Antigo/análise , FemininoRESUMO
The manuscript summarizes current approved contrast media and their indications. Contrast agents that are discussed include iodinated contrast agents, magnetic resonance (MR) contrast agents, and ultrasound contrast agents. Allergic and non-allergic renal adverse events are described. The clinical issue of metformin and the administration of contrast agents are updated. Nephrogenic systemic fibrosis (NSF) is discussed and safety issues of available MR contrast agents are analyzed. The most recent changes in European Society of Urogenital Radiology (ESUR) guidelines are also presented.
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Meios de Contraste/efeitos adversos , Meios de Contraste/normas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Guias de Prática Clínica como Assunto , Radiologia/normas , Europa (Continente) , Humanos , Radiologia/tendênciasRESUMO
BACKGROUND: Particularly at the beginning, the COVID-19 (coronavirus disease 2019) pandemic caused a reduction in the number of interventions in interventional radiology. At the same time, interventional training became more challenging. Infectious patients and disease transmission within interventional radiology departments continue to pose significant challenges. OBJECTIVES: This article describes the status and recommendations for interventional radiological procedures in COVID-19 patients. MATERIALS AND METHODS: Guidelines and recommendations from international and national societies as well as original works and reviews were evaluated. RESULTS: Interventional radiological care of COVID-19 patients with complicated courses of infection has become established during the course of the pandemic. To protect patients and staff, interventions in COVID-19 patients should be prioritized, performed in separate procedure rooms if possible, and patients should be tested before interventions. Logistics, staff planning, and hygiene measures should be continuously optimized. CONCLUSIONS: Structured workflows within interventional radiology in dealing with COVID-19 patients appear necessary to minimize infection risks and to guarantee the staff's work capability and health. In order to develop concepts for the handling of COVID-19 patients and to be prepared for potential upcoming waves of infections, recommendations of the Robert Koch Institute (RKI) and (inter-)national professional societies are helpful.
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COVID-19 , Humanos , SARS-CoV-2 , Radiologia Intervencionista/métodos , Pandemias/prevenção & controleRESUMO
We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.
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BACKGROUND: The COVID-19 pandemic had an unprecedented impact on clinical practice and healthcare professionals. We aimed to assess how interventional radiology services (IR services) were impacted by the pandemic and describe adaptations to services and working patterns across the first two waves. METHODS: An anonymous six-part survey created using an online service was distributed as a single-use web link to 7125 members of the Cardiovascular and Interventional Radiological Society of Europe via email. Out of 450 respondents, 327 who completed the survey at least partially including 278 who completed the full survey were included into the analysis. RESULTS: Interventional radiologists (IRs) reported that the overall workload decreased a lot (18%) or mildly (36%) or remained stable (29%), and research activities were often delayed (30% in most/all projects, 33% in some projects). Extreme concerns about the health of families, patients and general public were reported by 43%, 34% and 40%, respectively, and 29% reported having experienced significant stress (25% quite a bit; 23% somewhat). Compared to the first wave, significant differences were seen regarding changes to working patterns, effect on emergency work, outpatient and day-case services in the second wave. A total of 59% of respondents felt that their organisation was better prepared for a third wave. A total of 19% and 39% reported that the changes implemented would be continued or potentially continued on a long-term basis. CONCLUSION: While the COVID-19 pandemic has negatively affected IR services in terms of workload, research activity and emotional burden, IRs seem to have improved the own perception of adaptation and preparation for further waves of the pandemic.
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COVID-19 , Humanos , Pandemias/prevenção & controle , Radiologistas , Radiologia Intervencionista , Inquéritos e QuestionáriosRESUMO
PURPOSE: Since the incidental discovery and systematic introduction of mechanical endovascular stroke treatment in 2015 there are few reports about the real-life situation in daily clinical practice. The aim of this study was to evaluate the mechanical thrombectomy data documented in the quality assurance database of the German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR) and the German Society of Neuroradiology (DGNR) in 2019. METHODS: We retrospectively analyzed the clinical and procedural data of all mechanical thrombectomies that were entered into the voluntary nationwide database in 2019. The information of each procedure was provided on a standardized web-based data sheet. Data were exported and analyzed by a group of experts on behalf of the DGNR. RESULTS: A total of 13,840 data sets from 158 participating centers could be analyzed. Mean age of the patients was 74⯱ 13 years; 53.9% were female. Vessel occlusion was located in the anterior circulation in 87.4%, in the posterior circulation in 10.7%. On hospital admission, the median National Institutes of Health Stroke Scale (NIHSS) was 14 (lower/upper quartile 10/19); at hospital discharge, median NIHSS had dropped to 9 (lower/upper quartile 2/12; pâ¯<â¯0.001). Recanalization of the occluded vessel segment was successful (TICI 2bâ¯+ 3) in 88.4%. The reported complication rate was 7.3%, with subarachnoid hemorrhage as the most frequent complication (3.4%), followed by parenchymal hemorrhage (1.7%) and embolization in new territories (1.2%). Overall, the median time interval from symptom onset to hospital admission was 94â¯min (quartiles 59/180â¯min), the median time from hospital admission to groin puncture was 74â¯min (lower/upper quartile 47/103â¯min), and the median duration of the procedure 43â¯min (lower/upper quartile 25.2/73.2 min). A comparison between primary and secondary referral revealed a significant faster symptom-to-intervention time for primary referrals, whereas in-house workflows showed no significant difference. CONCLUSION: The analysis represents the largest documented cohort of acute stroke patients treated by thrombectomy. The documentation allows for a detailed evaluation of procedural, clinical, logistic and radiation exposure data and might be used for monitoring the quality of the treatment on a nationwide scale.
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Isquemia Encefálica , Procedimentos Endovasculares , Acidente Vascular Cerebral , Feminino , Alemanha/epidemiologia , Humanos , Recém-Nascido , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia , Trombectomia , Resultado do TratamentoRESUMO
Radiocarbon (14C), as a consequence of its production in the atmosphere and subsequent dispersal through the carbon cycle, is a key tracer for studying the Earth system. Knowledge of past 14C levels improves our understanding of climate processes, the Sun, the geodynamo, and the carbon cycle. Recently updated radiocarbon calibration curves (IntCal20, SHCal20, and Marine20) provide unprecedented accuracy in our estimates of 14C levels back to the limit of the 14C technique (~55,000 years ago). Such improved detail creates new opportunities to probe the Earth and climate system more reliably and at finer scale. We summarize the advances that have underpinned this revised set of radiocarbon calibration curves, survey the broad scientific landscape where additional detail on past 14C provides insight, and identify open challenges for the future.
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We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1, which is sensitive to short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the "superfast" quarks probed at x>1. The falloff at x>1 is noticeably stronger in 2H and 3He, but nearly identical for all heavier nuclei.
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How climate and ecology affect key cultural transformations remains debated in the context of long-term socio-cultural development because of spatially and temporally disjunct climate and archaeological records. The introduction of agriculture triggered a major population increase across Europe. However, in Southern Scandinavia it was preceded by ~500 years of sustained population growth. Here we show that this growth was driven by long-term enhanced marine production conditioned by the Holocene Thermal Maximum, a time of elevated temperature, sea level and salinity across coastal waters. We identify two periods of increased marine production across trophic levels (P1 7600-7100 and P2 6400-5900 cal. yr BP) that coincide with markedly increased mollusc collection and accumulation of shell middens, indicating greater marine resource availability. Between ~7600-5900 BP, intense exploitation of a warmer, more productive marine environment by Mesolithic hunter-gatherers drove cultural development, including maritime technological innovation, and from ca. 6400-5900 BP, underpinned a ~four-fold human population growth.
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Arqueologia , Clima , Evolução Cultural/história , Recursos Naturais/provisão & distribuição , Crescimento Demográfico , Agricultura , Animais , História Antiga , Humanos , Invenções/história , Moluscos , Oceanos e Mares , Países Escandinavos e NórdicosRESUMO
Venous thrombosis is one of the most common vascular diseases. Without treatment, pulmonary embolism is a potentially life-threatening complication. Long-term complications are chronic venous insufficiency and post-thrombotic syndrome. Medical anticoagulation is currently the standard therapy, since it prevents appositional thrombus growth although it usually can not prevent the development of post-thrombotic syndrome. The structure of the thrombotic material often leads to partial recanalisation with residual stenosis. Early and sufficient systemic thrombolysis with adequate concentration may achieve disintegration of the thrombus and preservation of venous valve function. Supplementary to conservative therapy, local catheter thrombolysis is possible even in cases with contraindications for a systemic thrombolysis therapy. Additional interventional techniques reduce the required concentration of the thrombolytic. Venous stenosis can be treated by balloon angioplasty and stent implantation. This article reviews the different percutaneous treatment options as well as their application and usefulness in thrombosis of the lower torso.
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Angioplastia com Balão/métodos , Veia Femoral , Fibrinolíticos/administração & dosagem , Veia Ilíaca , Embolia Pulmonar/terapia , Stents , Trombectomia , Terapia Trombolítica/métodos , Filtros de Veia Cava , Veia Cava Inferior , Trombose Venosa/terapia , Administração Tópica , Angiografia , Veia Femoral/diagnóstico por imagem , Fibrinolíticos/efeitos adversos , Humanos , Veia Ilíaca/diagnóstico por imagem , Infusões Intravenosas , Flebografia , Embolia Pulmonar/diagnóstico por imagem , Embolia Pulmonar/prevenção & controle , Terapia Trombolítica/efeitos adversos , Tomografia Computadorizada por Raios X , Veia Cava Inferior/diagnóstico por imagem , Trombose Venosa/diagnóstico por imagemRESUMO
Nephrogenic systemic fibrosis (NSF) is a relative new disease affecting predominantly patients with severely impaired kidney function. Strict adherence to a concordant clinical and pathological definition has allowed for careful separation of this entity from other fibrosing disorders, leading eventually to the realization that gadolinium based contrast agents were closely associated with its onset. Gadodiamide and similarly unstable Gd-CA should therefore not be used in patients with renal insufficiency. The clinical symptoms of NSF vary considerably from patient to patient. NSF should be suspected in renal failure patients presenting any possible NSF symptom appearing in the weeks after Gd-enhanced MRI. Suspected cases should have a skin biopsy taken from an affected region for the histological confirmation or rejection of the diagnosis. There are no established curative treatments to NSF patients. Prevention is the only alternative. Guidelines for the daily routine seem to be the right way. When NSF is identified the primary goal is reversal of underlying renal failure or renal transplantation. In addition, use of physical therapy and pain control is mandatory. One of the best news in late 2007 is the decreasing rate of newly detected NSF cases. In the case this development continues, NSF may become an historical disease in the near future.
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Dermopatia Fibrosante Nefrogênica , Biópsia , Meios de Contraste/efeitos adversos , Gadolínio DTPA/efeitos adversos , História do Século XX , História do Século XXI , Humanos , Imageamento por Ressonância Magnética/efeitos adversos , Dermopatia Fibrosante Nefrogênica/epidemiologia , Dermopatia Fibrosante Nefrogênica/etiologia , Dermopatia Fibrosante Nefrogênica/patologia , Dermopatia Fibrosante Nefrogênica/prevenção & controle , Guias de Prática Clínica como Assunto , Insuficiência Renal/complicações , Insuficiência Renal/terapia , Medição de Risco , Fatores de Risco , Pele/patologiaRESUMO
BACKGROUND: The study aimed to demonstrate the noninferiority of capecitabine to 5-fluorouracil (5-FU)/folinic acid (FA), in relation to progression-free survival (PFS) after first-line treatment of metastatic colorectal cancer and the benefit of adding celecoxib (C) to irinotecan/fluoropyrimidine regimens compared with placebo (P). PATIENTS AND METHODS: Patients were randomly assigned to receive FOLFIRI: irinotecan (180 mg/m(2) i.v. on days 1, 15 and 22); FA (200 mg/m(2) i.v. on days 1, 2, 15, 16, 29 and 30); 5-FU (400 mg/m(2) i.v. bolus, then 22-h, 600 mg/m(2) infusion) or CAPIRI: irinotecan (250 mg/m(2) i.v. infusion on days 1 and 22); capecitabine p.o. (1000 mg/m(2) b.i.d. on days 1-15 and 22-36). Patients were additionally randomly assigned to receive either placebo or celecoxib (800 mg: 2 x 200 mg b.i.d.). RESULTS: The trial was closed following eight deaths unrelated to disease progression in the 85 enrolled (629 planned) patients. Response rates were 22% for CAPIRI + C, 48% for CAPIRI + P, 32% for FOLFIRI + C and 46% for FOLFIRI + P. Median PFS and overall survival (OS) times were shorter for CAPIRI versus FOLFIRI (PFS 5.9 versus 9.6 months and OS 14.8 versus 19.9 months) and celecoxib versus placebo (PFS 6.9 versus 7.8 months and OS 18.3 versus 19.9 months). CONCLUSION: Due to the small sample size following early termination, no definitive conclusions can be drawn in relation to the noninferiority of CAPIRI compared with FOLFIRI.