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1.
Nature ; 600(7890): 621-624, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34937892

RESUMO

Magnetars are strongly magnetized, isolated neutron stars1-3 with magnetic fields up to around 1015 gauss, luminosities of approximately 1031-1036 ergs per second and rotation periods of about 0.3-12.0 s. Very energetic giant flares from galactic magnetars (peak luminosities of 1044-1047 ergs per second, lasting approximately 0.1 s) have been detected in hard X-rays and soft γ-rays4, and only one has been detected from outside our galaxy5. During such giant flares, quasi-periodic oscillations (QPOs) with low (less than 150 hertz) and high (greater than 500 hertz) frequencies have been observed6-9, but their statistical significance has been questioned10. High-frequency QPOs have been seen only during the tail phase of the flare9. Here we report the observation of two broad QPOs at approximately 2,132 hertz and 4,250 hertz in the main peak of a giant γ-ray flare11 in the direction of the NGC 253 galaxy12-17, disappearing after 3.5 milliseconds. The flare was detected on 15 April 2020 by the Atmosphere-Space Interactions Monitor instrument18,19 aboard the International Space Station, which was the only instrument that recorded the main burst phase (0.8-3.2 milliseconds) in the full energy range (50 × 103 to 40 × 106 electronvolts) without suffering from saturation effects such as deadtime and pile-up. Along with sudden spectral variations, these extremely high-frequency oscillations in the burst peak are a crucial component that will aid our understanding of magnetar giant flares.


Assuntos
Astros Celestes , Atmosfera
2.
J Synchrotron Radiat ; 31(Pt 2): 363-377, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38386565

RESUMO

The ForMAX beamline at the MAX IV Laboratory provides multiscale and multimodal structural characterization of hierarchical materials in the nanometre to millimetre range by combining small- and wide-angle X-ray scattering with full-field microtomography. The modular design of the beamline is optimized for easy switching between different experimental modalities. The beamline has a special focus on the development of novel fibrous materials from forest resources, but it is also well suited for studies within, for example, food science and biomedical research.

3.
J Phys Chem A ; 128(7): 1241-1249, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38324399

RESUMO

The recent implementation of attosecond and few-femtosecond X-ray pump/X-ray probe schemes in large-scale free-electron laser facilities has opened the way to visualize fast nuclear dynamics in molecules with unprecedented temporal and spatial resolution. Here, we present the results of theoretical calculations showing how polarization-averaged molecular-frame photoelectron angular distributions (PA-MFPADs) can be used to visualize the dynamics of hydrogen migration in methanol, ethanol, propanol, and isopropyl alcohol dications generated by X-ray irradiation of the corresponding neutral species. We show that changes in the PA-MFPADs with the pump-probe delay as a result of intramolecular photoelectron diffraction carry information on the dynamics of hydrogen migration in real space. Although visualization of this dynamics is more straightforward in the smaller systems, methanol and ethanol, one can still recognize the signature of that motion in propanol and isopropyl alcohol and assign a tentative path to it. A possible pathway for a corresponding experiment requires an angularly resolved detection of photoelectrons in coincidence with molecular fragment ions used to define a molecular frame of reference. Such studies have become, in principle, possible since the first XFELs with sufficiently high repetition rates have emerged. To further support our findings, we provide experimental evidence of H migration in ethanol-OD from ion-ion coincidence measurements performed with synchrotron radiation.

4.
Nature ; 562(7725): 82-85, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30283106

RESUMO

SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star)1-3. Two jets of ionized matter with a bulk velocity of approximately 0.26c (where c is the speed of light in vacuum) extend from the binary, perpendicular to the line of sight, and terminate inside W50, a supernova remnant that is being distorted by the jets2,4-8. SS 433 differs from other microquasars (small-scale versions of quasars that are present within our own Galaxy) in that the accretion is believed to be super-Eddington9-11, and the luminosity of the system is about 1040 ergs per second2,9,12,13. The lobes of W50 in which the jets terminate, about 40 parsecs from the central source, are expected to accelerate charged particles, and indeed radio and X-ray emission consistent with electron synchrotron emission in a magnetic field have been observed14-16. At higher energies (greater than 100 gigaelectronvolts), the particle fluxes of γ-rays from X-ray hotspots around SS 433 have been reported as flux upper limits6,17-20. In this energy regime, it has been unclear whether the emission is dominated by electrons that are interacting with photons from the cosmic microwave background through inverse-Compton scattering or by protons that are interacting with the ambient gas. Here we report teraelectronvolt γ-ray observations of the SS 433/W50 system that spatially resolve the lobes. The teraelectronvolt emission is localized to structures in the lobes, far from the centre of the system where the jets are formed. We have measured photon energies of at least 25 teraelectronvolts, and these are certainly not Doppler-boosted, because of the viewing geometry. We conclude that the emission-from radio to teraelectronvolt energies-is consistent with a single population of electrons with energies extending to at least hundreds of teraelectronvolts in a magnetic field of about 16 microgauss.

6.
Curr Urol Rep ; 25(6): 117-124, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38763948

RESUMO

PURPOSE OF REVIEW: Renal cell carcinoma presents a unique proclivity for vascular involvement giving rise to a peculiar form of locally advanced disease so-called tumor thrombus. To date, the only curative strategy for these cases remains surgery, which should aim to remove every vestige of macroscopic disease. Most of the preexisting literature advocates opening the vena cava to allow tumor thrombus removal and subsequent venous suture closure. However, inferior vena cava circumferential resection (cavectomy) without caval replacement is possible in the majority of cases since progressive occlusion facilitates the development of a collateral venous network aimed at maintaining cardiac preload. RECENT FINDINGS: Radical nephrectomy with tumor thrombectomy remains a surgical challenge not exempt of operative complications even in experienced hands. In opposition to what traditional cavotomy and thrombus withdrawal can offer, circumferential cavectomy without caval replacement would provide comparable or even better oncologic control, decrease the likelihood of operative bleeding, and prevent the development of perioperative pulmonary embolism. This review focuses on the rationale of circumferential IVC resection without caval replacement and the important technical aspects of this approach in cases of renal cell carcinoma with vascular involvement. We also include an initial report on the surgical outcomes of a contemporary series of patients managed under this approach at our center.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Células Neoplásicas Circulantes , Nefrectomia , Veia Cava Inferior , Humanos , Carcinoma de Células Renais/cirurgia , Neoplasias Renais/cirurgia , Veia Cava Inferior/cirurgia , Nefrectomia/métodos , Trombectomia/métodos
7.
Public Health ; 230: 12-20, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38479163

RESUMO

OBJECTIVE: This article aims to estimate the differences in environmental impact (greenhouse gas [GHG] emissions, land use, energy used, acidification and potential eutrophication) after one year of promoting a Mediterranean diet (MD). METHODS: Baseline and 1-year follow-up data from 5800 participants in the PREDIMED-Plus study were used. Each participant's food intake was estimated using validated semi-quantitative food frequency questionnaires, and the adherence to MD using the Dietary Score. The influence of diet on environmental impact was assessed through the EAT-Lancet Commission tables. The influence of diet on environmental impact was assessed through the EAT-Lancet Commission tables. The association between MD adherence and its environmental impact was calculated using adjusted multivariate linear regression models. RESULTS: After one year of intervention, the kcal/day consumed was significantly reduced (-125,1 kcal/day), adherence to a MD pattern was improved (+0,9) and the environmental impact due to the diet was significantly reduced (GHG: -361 g/CO2-eq; Acidification:-11,5 g SO2-eq; Eutrophication:-4,7 g PO4-eq; Energy use:-842,7 kJ; and Land use:-2,2 m2). Higher adherence to MD (high vs. low) was significantly associated with lower environmental impact both at baseline and one year follow-up. Meat products had the greatest environmental impact in all the factors analysed, both at baseline and at one-year follow-up, in spite of the reduction observed in their consumption. CONCLUSIONS: A program promoting a MD, after one year of intervention, significantly reduced the environmental impact in all the factors analysed. Meat products had the greatest environmental impact in all the dimensions analysed.


Assuntos
Dieta Mediterrânea , Gases de Efeito Estufa , Humanos , Dieta , Meio Ambiente , Coleta de Dados
8.
J Environ Manage ; 356: 120638, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38518496

RESUMO

Microorganisms drive the degradation of organic matter thanks to their enzymatic versatility. However, the structure of lignocellulose poses a great challenge for the microbiota inhabiting a compost pile. Our purpose was to increase the biodegradability of vegetable waste in the early stages of the composting process by applying a microbial consortium with lignocelllulolytic capacity. For this, a previous screening was performed among the culturable microbiota from different composting processes to find inoculants with ligninocellulolytic activity. Selected strains were applied as a pure culture and as a microbial consortium. The starting material was composed of tomato plant and pruning remains mixed in a ratio (50:50 v/v), whose humidity was adjusted to around 65%. To determine the ability of both treatments to activate the biodegradation of the mixtures, moisture, organic matter, ash, C/N ratio, 4-day cumulative respirometric index (AT4) and degradation rates of cellulose, hemicellulose and lignin were evaluated. Subsequently, a real composting process was developed in which the performance of the microbial consortium was compared with the composting process without inoculum (control). According to our tests, three microbial strains (Bacillus safensis, Bacillus licheniformis and Fusarium oxysporum) were selected. The results showed that the application of the bacteria strains at low doses (104 CFU g-1 on the complete residual material of the pile) resulted in higher rates of lignocelullose degradation after 10 days of treatment compared to that observed after application of the fungus in pure culture or untreated controls. The implementation of the strategy described in this work resulted in obtaining compost with better agronomic quality than the uninoculated controls. Therefore, the application of this consortium could be considered as an interesting tool for bioactivation of lignocellulosic waste prior to the composting process.


Assuntos
Compostagem , Lignina , Lignina/metabolismo , Celulose , Bactérias/metabolismo , Solo
9.
Med Oral Patol Oral Cir Bucal ; 29(1): e128-e134, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37823297

RESUMO

BACKGROUND: Inflammatory biomarkers, including C-reactive protein, erythrocyte sedimentation rate, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, and the systemic immune-inflammation index, have been proposed as prognostic factors diverse pathologies. However, their application for deep neck infections has yet to be clarified. MATERIAL AND METHODS: We performed a retrospective study of 163 adult patients with diagnosis of deep neck infections with the aim to evaluate the association between serological biomarkers with complications and outcomes of patients with DNI. Studied variables included demographic data, complications of DNI, outcomes, complications and death of the included subjects. The evaluated serological biomarkers were hemoglobin, leukocytes, neutrophils, lymphocytes, platelets, glucose, creatinine, albumin, CRP, and ESR. NLR, PLR, and SIII index were estimated. RESULTS: The patients' mean age was 40.6 ± 15.3 years. Complications of DNI were observed in 19.6% (n=32) patients, being the need for tracheostomy due to airway obstruction (11%, n=18) and mediastinitis (8.6%, n= 14) the most common. Evaluated subjects had an increased value of serological biomarkers (SII index 2639.9 ± 2062.9, NLR 11.3 ± 8.5, PLR 184.1 ± 108.5, CRP 12.6 ± 8.9 mg/dL, ESR 20.7 ± 9.1 mm/h). Patients with complications had a significantly higher value of all inflammatory parameters (p < 0.05). A SII index cut-off value of 2975 was selected from a ROC curve analysis. A sensitivity of 93.8%, specificity of 86.3%, a positive predictive value of 62.5%, and a negative predictive value of 98.3% are reported. The SII index was found to have an increased positive predictive value compared to NLR, PLR, and CRP for DNI complications. CONCLUSIONS: Our analysis concluded that the SII index, NLR, and PLR are valuable biomarkers to assess the risk of complications from DNI. SII index showed a high accuracy for prediction of DNI complications with a cut-off value of 2975.


Assuntos
Inflamação , Linfócitos , Adulto , Humanos , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Biomarcadores , Linfócitos/patologia
10.
Foot Ankle Surg ; 30(2): 117-122, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37949704

RESUMO

BACKGROUND: Platelet-rich plasma (PRP) and botulinum toxin type A (BTX-A) injections have proven effective in clinical trials for plantar fasciitis treatment but have not been directly compared. We aimed to compare clinical outcomes in patients undergoing PRP or BTX-A injections. METHODS: We performed a randomised controlled trial (59 patients; 1-year follow-up) to assess efficacy, using pain and functional scales (VAS, AOFAS Hindfoot-scale and FAAM questionnaire) and fascia thickness reduction, in control and single ultrasound-guided BTX-A or PRP injection groups. RESULTS: The BTX-A group showed better results at 1-month after treatment. Conversely, the PRP injection was more effective in the long-term, with significant pain reduction and functional improvement. Plantar fascia thickness significantly reduced from months 1 and 3 in the PRP and BTX-A groups, respectively. CONCLUSION: PRP and BTX-A injections are effective in patients with plantar fasciitis with BTX-A achieving better short-term pain reduction and PRP better long-term results. LEVEL OF EVIDENCE: Level I; Randomised Controlled Trial.


Assuntos
Toxinas Botulínicas Tipo A , Fasciíte Plantar , Plasma Rico em Plaquetas , Humanos , Fasciíte Plantar/terapia , Fasciíte Plantar/tratamento farmacológico , Toxinas Botulínicas Tipo A/uso terapêutico , Dor , Ultrassonografia de Intervenção , Resultado do Tratamento
11.
Cancer Immunol Immunother ; 72(11): 3475-3489, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37606856

RESUMO

BACKGROUND: Immune checkpoint inhibitors (ICI) substantially improve outcome for patients with cancer. However, the majority of patients develops immune-related adverse events (irAEs), which can be persistent and significantly reduce quality of life. Neurological irAEs occur in 1-5% of patients and can induce severe, permanent sequelae or even be fatal. In order to improve the diagnosis and treatment of neurological irAEs and to better understand their pathogenesis, we assessed whether previous neurotropic infections are associated with neurological irAEs. METHODS: Neurotropic infections that might predispose to ICI-induced neurological irAEs were analyzed in 61 melanoma patients from 3 countries, the Netherlands, Australia and Germany, including 24 patients with neurotoxicity and 37 control patients. In total, 14 viral, 6 bacterial, and 1 protozoal infections previously reported to trigger neurological pathologies were assessed using routine serology testing. The Dutch and Australian cohorts (NL) included pre-treatment plasma samples of patients treated with neoadjuvant ICI therapy (OpACIN-neo and PRADO trials; NCT02977052). In the Dutch/Australian cohort a total of 11 patients with neurological irAEs were compared to 27 control patients (patients without neurological irAEs). The German cohort (LMU) consisted of serum samples of 13 patients with neurological irAE and 10 control patients without any documented irAE under ICI therapy. RESULTS: The association of neurological irAEs with 21 possible preceding infections was assessed by measuring specific antibodies against investigated agents. The seroprevalence of all the tested viral (cytomegalovirus, Epstein-Barr-Virus, varicella-zoster virus, measles, rubella, influenza A and B, human herpes virus 6 and 7, herpes simplex virus 1 and 2, parvovirus B19, hepatitis A and E and human T-lymphotropic virus type 1 and 2), bacterial (Borrelia burgdorferi sensu lato, Campylobacter jejuni, Mycoplasma pneumoniae, Coxiella burnetti, Helicobacter pylori, Yersinia enterocolitica and Y. pseudotuberculosis) and protozoal (Toxoplasma gondii) infections was similar for patients who developed neurological irAEs as compared to control patients. Thus, the analysis provided no evidence for an association of described agents tested for seroprevalence with ICI induced neurotoxicity. CONCLUSION: Previous viral, bacterial and protozoal neurotropic infections appear not to be associated with the development of neurological irAEs in melanoma patients who underwent therapy with ICI across 3 countries. Further efforts are needed to unravel the factors underlying neurological irAEs in order to identify risk factors for these toxicities, especially with the increasing use of ICI in earlier stage disease.


Assuntos
Antineoplásicos Imunológicos , Melanoma , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Estudos Soroepidemiológicos , Qualidade de Vida , Antineoplásicos Imunológicos/uso terapêutico , Austrália/epidemiologia , Melanoma/tratamento farmacológico , Estudos Retrospectivos
12.
Opt Express ; 31(3): 3504-3519, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36785342

RESUMO

Nowadays, atom-based quantum sensors are leaving the laboratory towards field applications requiring compact and robust laser systems. Here we describe the realization of a compact laser system for atomic gravimetry. Starting with a single diode laser operating at 780 nm and adding only one fiber electro-optical modulator, one acousto-optical modulator and one laser amplifier we produce laser beams at all the frequencies required for a Rb-87 atomic gravimeter. Furthermore, we demonstrate that an atomic fountain configuration can also be implemented with our laser system. The modulated system reported here represents a substantial advance in the simplification of the laser source for transportable atom-based quantum sensors that can be adapted to other sensors such as atomic clocks, accelerometers, gyroscopes or magnetometers with minor modifications.

13.
Phys Rev Lett ; 130(6): 061002, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36827578

RESUMO

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28} cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25} cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

14.
Phys Rev Lett ; 131(5): 051201, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37595214

RESUMO

We report the first detection of a TeV γ-ray flux from the solar disk (6.3σ), based on 6.1 years of data from the High Altitude Water Cherenkov (HAWC) observatory. The 0.5-2.6 TeV spectrum is well fit by a power law, dN/dE=A(E/1 TeV)^{-γ}, with A=(1.6±0.3)×10^{-12} TeV^{-1} cm^{-2} s^{-1} and γ=3.62±0.14. The flux shows a strong indication of anticorrelation with solar activity. These results extend the bright, hard GeV emission from the disk observed with Fermi-LAT, seemingly due to hadronic Galactic cosmic rays showering on nuclei in the solar atmosphere. However, current theoretical models are unable to explain the details of how solar magnetic fields shape these interactions. HAWC's TeV detection thus deepens the mysteries of the solar-disk emission.

15.
BMC Gastroenterol ; 23(1): 375, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37915010

RESUMO

BACKGROUND: Natural orifice transluminal endoscopy surgery (NOTES) gastrojejunal anastomosis (GJA) with duodenal exclusion (DE) could be used as a less invasive alternative to surgical gastric bypass. The aim of this study was to compare the efficacy and safety of both methods for bariatric purpose. METHODS: This was a prospective, experimental and comparative study on 27 obese living pigs, comparing 4 groups: GJA alone (group 1, G1), GJA + DE (group 2, G2), surgical gastric bypass (group 3, G3), control group (group 4, G4). GJA was endoscopically performed, using NOTES technic and LAMS, while DE was performed surgically for limb length selection. Animals were followed for 3 months. Primary outcome included technical success and weight change, while secondary endpoints included the rate of perioperative mortality and morbidity, histological anastomosis analysis and biological analysis. RESULTS: Technical success was 100% in each intervention group. No death related to endoscopic procedures occurred in the endoscopic groups, while early mortality (< 1 month) was 57,1% in the surgical group, all due to anastomotic dehiscence. At 3 months, compared to baseline, mean weight change was + 3,1% in G1 (p = 0,46); -14,9% in G2 (p = 0,17); +5,6% in G3 (p = 0,38) and + 25% in G4 (p = 0,029). Histopathological analysis of endoscopic GJA showed complete fusion of different layers without leak or abscess. CONCLUSIONS: Endoscopic GJA with DE provides the efficacy of bypass on weight control in an animal model. Next steps consist of the development of devices to perform exclusively endoscopically limb length selection and DE.


Assuntos
Derivação Gástrica , Laparoscopia , Obesidade Mórbida , Suínos , Animais , Estudos Prospectivos , Endoscopia , Obesidade/cirurgia , Derivação Gástrica/métodos , Obesidade Mórbida/cirurgia , Resultado do Tratamento
16.
Crit Care ; 27(1): 450, 2023 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-37986015

RESUMO

BACKGROUND: CONCISE is an internationally agreed minimum set of outcomes for use in nutritional and metabolic clinical research in critically ill adults. Clinicians and researchers need to be aware of the clinimetric properties of these instruments and understand any limitations to ensure valid and reliable research. This systematic review and meta-analysis were undertaken to evaluate the clinimetric properties of the measurement instruments identified in CONCISE. METHODS: Four electronic databases were searched from inception to December 2022 (MEDLINE via Ovid, EMBASE via Ovid, CINAHL via Healthcare Databases Advanced Search, CENTRAL via Cochrane). Studies were included if they examined at least one clinimetric property of a CONCISE measurement instrument or recognised variation in adults ≥ 18 years with critical illness or recovering from critical illness in any language. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist for systematic reviews of Patient-Reported Outcome Measures was used. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were used in line with COSMIN guidance. The COSMIN checklist was used to evaluate the risk of bias and the quality of clinimetric properties. Overall certainty of the evidence was rated using a modified Grading of Recommendations, Assessment, Development and Evaluation approach. Narrative synthesis was performed and where possible, meta-analysis was conducted. RESULTS: A total of 4316 studies were screened. Forty-seven were included in the review, reporting data for 12308 participants. The Short Form-36 Questionnaire (Physical Component Score and Physical Functioning), sit-to-stand test, 6-m walk test and Barthel Index had the strongest clinimetric properties and certainty of evidence. The Short Physical Performance Battery, Katz Index and handgrip strength had less favourable results. There was limited data for Lawson Instrumental Activities of Daily Living and the Global Leadership Initiative on Malnutrition criteria. The risk of bias ranged from inadequate to very good. The certainty of the evidence ranged from very low to high. CONCLUSIONS: Variable evidence exists to support the clinimetric properties of the CONCISE measurement instruments. We suggest using this review alongside CONCISE to guide outcome selection for future trials of nutrition and metabolic interventions in critical illness. TRIAL REGISTRATION: PROSPERO (CRD42023438187). Registered 21/06/2023.


Assuntos
Estado Terminal , Força da Mão , Adulto , Humanos , Estado Terminal/terapia , Atividades Cotidianas , Resultado do Tratamento , Avaliação de Resultados em Cuidados de Saúde
17.
Nature ; 547(7664): 425-427, 2017 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-28748924

RESUMO

Newly formed black holes of stellar mass launch collimated outflows (jets) of ionized matter that approach the speed of light. These outflows power prompt, brief and intense flashes of γ-rays known as γ-ray bursts (GRBs), followed by longer-lived afterglow radiation that is detected across the electromagnetic spectrum. Measuring the polarization of the observed GRB radiation provides a direct probe of the magnetic fields in the collimated jets. Rapid-response polarimetric observations of newly discovered bursts have probed the initial afterglow phase, and show that, minutes after the prompt emission has ended, the degree of linear polarization can be as high as 30 per cent-consistent with the idea that a stable, globally ordered magnetic field permeates the jet at large distances from the central source. By contrast, optical and γ-ray observations during the prompt phase have led to discordant and often controversial results, and no definitive conclusions have been reached regarding the origin of the prompt radiation or the configuration of the magnetic field. Here we report the detection of substantial (8.3 ± 0.8 per cent from our most conservative simulation), variable linear polarization of a prompt optical flash that accompanied the extremely energetic and long-lived prompt γ-ray emission from GRB 160625B. Our measurements probe the structure of the magnetic field at an early stage of the jet, closer to its central black hole, and show that the prompt phase is produced via fast-cooling synchrotron radiation in a large-scale magnetic field that is advected from the black hole and distorted by dissipation processes within the jet.

18.
Med Oral Patol Oral Cir Bucal ; 28(4): e355-e361, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-36641741

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is the cause of the ongoing coronavirus disease 2019 (COVID-19) pandemic. It has been hypothesized oral health may be related to the severity and complications of COVID-19. The aim of this study was to analyze the prevalence of apical periodontitis and the frequency of root canal treatment in a sample of patients with SARS-CoV-2 infection (COVID-19), correlating them with the severity of the disease. MATERIAL AND METHODS: This retrospective study was conducted following the Strengthening Reporting Observational Studies in Epidemiology (STROBE) guidelines. The study examined 280 patients with positive real time PCR COVID-19 test whose treatment was performed in our hospital. Fifty-two patients aged 52.3 ± 17.3 years, including 30 males and 22 females, who had an orthopantomography in their clinical record, performed in the last 2 years, were included. Patients with SARS-CoV-2 infection were grouped as mild or moderate (MM) and severe or critical (SC) illness groups, according to the NIH COVID-19 Treatment Guidelines (Wu & McGoogan 2020). Radiographic records were analyzed and apical periodontitis (AP) was diagnosed as radiolucent periapical lesions (RPLs), using the periapical index score (PAI). Student's t test, χ2 test and multivariate logistic regression were used in the statistical analysis. RESULTS: The number of carious teeth was significantly higher in the SC group (3.4 ± 4.1), which showed more than twice as many teeth with carious lesions than the MM group (1.4 ± 1.8) (p = 0.02). Multivariate regression analysis showed association between the number of carious teeth and the severity of SARS-CoV-2 disease (OR = 1.5; 95% CI = 1.1-2.1; p = 0.017). Endodontic status (OR = 7.12; 95% CI = 1.2-40.9; p = 0.027) also correlated with the disease severity. CONCLUSIONS: The results suggest that the oral health status of COVID-19 patients correlated with the severity of the SARS-CoV-2 virus infection. Significant association has been found between the severity of COVID-19 disease and the presence of a greater number of teeth with caries lesions, as well as with endodontic status.


Assuntos
COVID-19 , Cárie Dentária , Periodontite Periapical , Masculino , Feminino , Humanos , SARS-CoV-2 , Estudos Retrospectivos , Tratamento Farmacológico da COVID-19 , Periodontite Periapical/epidemiologia , Periodontite Periapical/etiologia , Periodontite Periapical/terapia , Cárie Dentária/complicações
19.
Med Oral Patol Oral Cir Bucal ; 28(1): e25-e31, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36173714

RESUMO

BACKGROUND: Odontogenic deep neck infections remain a common condition that presents a challenging issue due to the complex involvement of the neck and adjacent structures and its potential life-threatening risk. Periapical infection of the second or third molar with spread to the submandibular and parapharyngeal spaces is the most commonly observed scenario. However, the time of dental extraction of the infection focus remains controversial. The aim of this study is to provide an overview of the epidemiology, clinical and radiological features, and management in patients diagnosed with ODNI and to identify the role of early dental extraction on patient outcomes and recovery. MATERIAL AND METHODS: This retrospective study included patients over 18 years old with a diagnosis of ODNI who were admitted to the University Hospital "Dr Jose Eleuterio Gonzalez" from January 2017 to January 2022. ODNI diagnosis was based on clinical and radiological evidence of the disease supplemented by dental and maxillofacial evaluation for an odontogenic aetiology. RESULTS: A total of 68 patients were included in the study. The patients' mean age was 40.96 ± 14.9. Diabetes mellitus was the most common comorbidity. The submandibular space was the most common deep neck space involved (n=59, 86.8%). Mediastinitis, marginal nerve injury and orocervical fistula were observed in 7.5% of patients, with no fatality in this series. A delay of >3 days for dental extraction of the involved tooth was associated with an increased rate of mediastinitis (n=3, 100%, p= 0.022), number of surgical interventions (1.45 ± 0.61, p= 0.006), ICU stay (n=8, 40%, p= 0.019), and ICU length of stay (0.85 ± 0.8, p= 0.001). CONCLUSIONS: Expedited management with surgical drainage and intravenous antibiotic treatment, along with early extraction of the involved tooth, is mandatory.


Assuntos
Mediastinite , Humanos , Adulto , Pessoa de Meia-Idade , Adolescente , Estudos Retrospectivos , Mediastinite/diagnóstico , Mediastinite/tratamento farmacológico , Mediastinite/etiologia , Pescoço , Hospitalização , Antibacterianos/uso terapêutico
20.
Am J Gastroenterol ; 117(2): 301-310, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34962498

RESUMO

INTRODUCTION: Several scoring systems predict mortality in alcohol-associated hepatitis (AH), including the Maddrey discriminant function (mDF) and model for end-stage liver disease (MELD) score developed in the United States, Glasgow alcoholic hepatitis score in the United Kingdom, and age, bilirubin, international normalized ratio, and creatinine score in Spain. To date, no global studies have examined the utility of these scores, nor has the MELD-sodium been evaluated for outcome prediction in AH. In this study, we assessed the accuracy of different scores to predict short-term mortality in AH and investigated additional factors to improve mortality prediction. METHODS: Patients admitted to hospital with a definite or probable AH were recruited by 85 tertiary centers in 11 countries and across 3 continents. Baseline demographic and laboratory variables were obtained. The primary outcome was all-cause mortality at 28 and 90 days. RESULTS: In total, 3,101 patients were eligible for inclusion. After exclusions (n = 520), 2,581 patients were enrolled (74.4% male, median age 48 years, interquartile range 40.9-55.0 years). The median MELD score was 23.5 (interquartile range 20.5-27.8). Mortality at 28 and 90 days was 20% and 30.9%, respectively. The area under the receiver operating characteristic curve for 28-day mortality ranged from 0.776 for MELD-sodium to 0.701 for mDF, and for 90-day mortality, it ranged from 0.773 for MELD to 0.709 for mDF. The area under the receiver operating characteristic curve for mDF to predict death was significantly lower than all other scores. Age added to MELD obtained only a small improvement of AUC. DISCUSSION: These results suggest that the mDF score should no longer be used to assess AH's prognosis. The MELD score has the best performance in predicting short-term mortality.


Assuntos
Doença Hepática Terminal/etiologia , Hepatite Alcoólica/mortalidade , Fígado/fisiopatologia , Adulto , Análise Discriminante , Doença Hepática Terminal/mortalidade , Doença Hepática Terminal/fisiopatologia , Feminino , Seguimentos , Saúde Global , Hepatite Alcoólica/complicações , Hepatite Alcoólica/fisiopatologia , Humanos , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Fatores de Risco , Índice de Gravidade de Doença , Taxa de Sobrevida/tendências , Fatores de Tempo
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