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1.
Nat Astron ; 8(4): 504-519, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38659610

RESUMO

Dust associated with various stellar sources in galaxies at all cosmic epochs remains a controversial topic, particularly whether supernovae play an important role in dust production. We report evidence of dust formation in the cold, dense shell behind the ejecta-circumstellar medium (CSM) interaction in the Type Ia-CSM supernova (SN) 2018evt three years after the explosion, characterized by a rise in mid-infrared emission accompanied by an accelerated decline in the optical radiation of the SN. Such a dust-formation picture is also corroborated by the concurrent evolution of the profiles of the Hα emission line. Our model suggests enhanced CSM dust concentration at increasing distances from the SN as compared to what can be expected from the density profile of the mass loss from a steady stellar wind. By the time of the last mid-infrared observations at day +1,041, a total amount of 1.2 ± 0.2 × 10-2 M⊙ of new dust has been formed by SN 2018evt, making SN 2018evt one of the most prolific dust factories among supernovae with evidence of dust formation. The unprecedented witness of the intense production procedure of dust may shed light on the perceptions of dust formation in cosmic history.

2.
Nat Astron ; 7(9): 1098-1107, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37736027

RESUMO

Detecting gravitationally lensed supernovae is among the biggest challenges in astronomy. It involves a combination of two very rare phenomena: catching the transient signal of a stellar explosion in a distant galaxy and observing it through a nearly perfectly aligned foreground galaxy that deflects light towards the observer. Here we describe how high-cadence optical observations with the Zwicky Transient Facility, with its unparalleled large field of view, led to the detection of a multiply imaged type Ia supernova, SN Zwicky, also known as SN 2022qmx. Magnified nearly 25-fold, the system was found thanks to the standard candle nature of type Ia supernovae. High-spatial-resolution imaging with the Keck telescope resolved four images of the supernova with very small angular separation, corresponding to an Einstein radius of only θE = 0.167″ and almost identical arrival times. The small θE and faintness of the lensing galaxy are very unusual, highlighting the importance of supernovae to fully characterize the properties of galaxy-scale gravitational lenses, including the impact of galaxy substructures.

4.
Tech Coloproctol ; 27(3): 189-208, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36138307

RESUMO

BACKGROUND: The aim of this meta-analysis was to assess the impact of operative blood loss on short and long-term outcomes following colorectal cancer surgery. METHODS: A systematic literature review and meta-analysis were performed, from inception to the 10th of August 2020. A comprehensive literature search was performed on the 10th of August 2020 of PubMed MEDLINE, Embase, Science Citation Index Expanded, and Cochrane Central Register of Controlled Trials. Only studies reporting on operative blood loss and postoperative short term or long-term outcomes in colorectal cancer surgery were considered for inclusion. RESULTS: Forty-three studies were included, reporting on 59,813 patients. Increased operative blood loss was associated with higher morbidity, for blood loss greater than 150-350 ml (odds ratio [OR] 2.09, p < 0.001) and > 500 ml (OR 2.29, p = 0.007). Anastomotic leak occurred more frequently for blood loss above a range of 50-100 ml (OR 1.14, p = 0.007), 250-300 ml (OR 2.06, p < 0.001), and 400-500 ml (OR 3.15, p < 0.001). Postoperative ileus rate was higher for blood loss > 100-200 ml (OR 1.90, p = 0.02). Surgical site infections were more frequent above 200-500 ml (OR 1.96, p = 0.04). Hospital stay was increased for blood loss > 150-200 ml (OR 1.63, p = 0.04). Operative blood loss was significantly higher in patients that suffered morbidity (mean difference [MD] 133.16 ml, p < 0.001) or anastomotic leak (MD 69.56 ml, p = 0.02). In the long term, increased operative blood loss was associated with worse overall survival above a range of 200-500 ml (hazard ratio [HR] 1.15, p < 0.001), and worse recurrence-free survival above 200-400 ml (HR 1.33, p = 0.01). Increased blood loss was associated with small bowel obstruction caused by colorectal cancer recurrence for blood loss higher than 400 ml (HR 1.97, p = 0.03) and 800 ml (HR 3.78, p = 0.02). CONCLUSIONS: Increased operative blood loss may adversely impact short term and long-term postoperative outcomes. Measures should be taken to minimize operative blood loss during colorectal cancer surgery. Due to the uncertainty of evidence identified, further research, with standardised methodology, is required on this important subject.


Assuntos
Neoplasias Colorretais , Procedimentos Cirúrgicos do Sistema Digestório , Humanos , Fístula Anastomótica/epidemiologia , Fístula Anastomótica/etiologia , Perda Sanguínea Cirúrgica , Infecção da Ferida Cirúrgica , Neoplasias Colorretais/cirurgia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia
5.
Microbiol Resour Announc ; 11(12): e0077122, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36321902

RESUMO

GantcherGoblin is a lytic siphovirus that was isolated on Arthrobacter globiformis B-2979 from soil collected in Massachusetts. The 55,368-bp genome has a GC content of 50.1% and 91 predicted protein-coding genes. Based on gene content similarity to phages in the Actinobacteriophage Database, GantcherGoblin was assigned to phage subcluster AU6.

6.
Sci Rep ; 12(1): 4665, 2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35304500

RESUMO

For several decades, the interest of the scientific community in aneutronic fusion reactions such as proton-Boron fusion has grown because of potential applications in different fields. Recently, many scientific teams in the world have worked experimentally on the possibility to trigger proton-Boron fusion using intense lasers demonstrating an important renewal of interest of this field. It is now possible to generate ultra-short high intensity laser pulses at high repetition rate. These pulses also have unique properties that can be leveraged to produce proton-Boron fusion reactions. In this article, we investigate the interaction of a high energy attosecond pulse with a solid proton-Boron target and the associated ion acceleration supported by numerical simulations. We demonstrate the efficiency of single-cycle attosecond pulses in comparison to multi-cycle attosecond pulses in ion acceleration and magnetic field generation. Using these results we also propose a path to proton-Boron fusion using high energy attosecond pulses.

7.
Tech Coloproctol ; 26(6): 413-423, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35132505

RESUMO

BACKGROUND: The aim of this study was to compare energy devices used for intraoperative hemostasis during colorectal surgery. METHODS: A systematic literature review and Bayesian network meta-analysis performed. MEDLINE, EMBASE, Science Citation Index Expanded, and Cochrane were searched from inception to August 11th 2021. Intraoperative outcomes were operative blood loss, operative time, conversion to open, conversion to another energy source. Postoperative outcomes were mortality, overall complications, minor complications and major complications, wound complications, postoperative ileus, anastomotic leak, time to first defecation, day 1 and 3 drainage volume, duration of hospital stay. RESULTS: Seven randomized controlled trials (RCTs) were included, reporting on 680 participants, comparing conventional hemostasis, LigaSure™, Thunderbeat® and Harmonic®. Harmonic® had fewer overall complications compared to conventional hemostasis. Operative blood loss was less with LigaSure™ (mean difference [MD] = 24.1 ml; 95% confidence interval [CI] - 46.54 to - 1.58 ml) or Harmonic® (MD = 24.6 ml; 95% CI - 42.4 to - 6.7 ml) compared to conventional techniques. Conventional hemostasis ranked worst for operative blood loss with high probability (p = 0.98). LigaSure™, Harmonic® or Thunderbeat® resulted in a significantly shorter mean operative time by 42.8 min (95% CI - 53.9 to - 31.5 min), 28.3 min (95% CI - 33.6 to - 22.6 min) and 26.1 min (95% CI - 46 to - 6 min), respectively compared to conventional electrosurgery. LigaSure™ resulted in a significantly shorter mean operative time than Harmonic® by 14.5 min (95% CI 1.9-27 min) and ranked first for operative time with high probability (p = 0.97). LigaSure™ and Harmonic® resulted in a significantly shorter mean duration of hospital stay compared to conventional electrosurgery of 1.3 days (95% CI - 2.2 to - 0.4) and 0.5 days (95% CI - 1 to - 0.1), respectively. LigaSure™ ranked as best for hospital stay with high probability (p = 0.97). Conventional hemostasis was associated with more wound complications than Harmonic® (odds ratio [OR] = 0.27; CI 0.08-0.92). Harmonic® ranked best with highest probability (p = 0.99) for wound complications. No significant differences between energy devices were identified for the remaining outcomes. CONCLUSIONS: LigaSure™, Thunderbeat® and Harmonic® may be advantageous for reducing operative blood loss, operative time, overall complications, wound complications, and duration of hospital stay compared to conventional techniques. The energy devices result in comparable perioperative outcomes and no device is superior overall. However, included RCTs were limited in number and size, and data were not available to compare all energy devices for all outcomes of interest.


Assuntos
Cirurgia Colorretal , Perda Sanguínea Cirúrgica , Cirurgia Colorretal/efeitos adversos , Humanos , Tempo de Internação , Metanálise em Rede , Duração da Cirurgia , Complicações Pós-Operatórias/etiologia
8.
Nature ; 601(7892): 201-204, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35022591

RESUMO

The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars1 emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion4. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.

9.
Phys Rev Appl ; 17(4)2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37965129

RESUMO

Most microwave readout architectures in quantum computing or sensing rely on a semiconductor amplifier at 4 K, typically a high-electron mobility transistor (HEMT). Despite its remarkable noise performance, a conventional HEMT dissipates several milliwatts of power, posing a practical challenge to scale up the number of qubits or sensors addressed in these architectures. As an alternative, we present an amplification chain consisting of a kinetic inductance traveling-wave parametric amplifier (KITWPA) placed at 4 K, followed by a HEMT placed at 70 K, and demonstrate a chain-added noise TΣ=6.3±0.5K between 3.5 and 5.5 GHz. While, in principle, any parametric amplifier can be quantum limited even at 4 K, in practice we find the performance of the KITWPA to be limited by the temperature of its inputs and by an excess of noise Tex=1.9K. The dissipation of the rf pump of the KITWPA constitutes the main power load at 4 K and is about 1% that of a HEMT. These combined noise and power dissipation values pave the way for the use of the KITWPA as a replacement for semiconductor amplifiers.

10.
Opt Lett ; 46(18): 4570-4573, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34525049

RESUMO

A proposal for additional temporal compression and peak power enhancement of intense (>TW/cm2) femtosecond laser pulses using two thin plane-parallel plates is presented. The first ultrathin plate (order of mm) induces spectral broadening due to self-phase modulation, and the second ultrathin plate (order of micron) corrects the spectral phase. The elimination of the negative dispersive multilayer coating from the scheme offers an improved laser-induced damage threshold for the post-compression process.

11.
J Environ Anal Toxicol ; 8(1)2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34094707

RESUMO

In 2006, the Agency for Toxic Substances and Disease Registry received a request to determine whether a cluster of polycythemia vera patients existed in a northeast Pennsylvania community. A significant cluster of PV cases was identified at the nexus of three counties near several hazardous waste sites. The current study evaluated the potential for a select number of environmental contaminants previously detected in the cluster area to induce DNA damage using in vitro assays with hematopoietic stem-cell derived progenitor cells. CD34+ cells were isolated from normal cord blood samples and were cultured for 48-72 hours to generate erythroid progenitor cells. Eighteen compounds were chosen for the assay; arsenic trioxide, benzo(a)pyrene, benzene, methylene chloride, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), trichloroethylene, potassium chloride, ethylbenzene, benzo[k]fluoranthene, styrene, cadmium chloride, hydroquinone, 1,1,1-trichloroethane, sodium cyanide, manganese chloride, chromium oxide, lead oxide, and sodium arsenite. Genotoxicity of the compounds was determined using the comet assay, and toxicity determined via the cell viability assay. Using the comet assay, 16 compounds at 10 nM concentration, induced a significant amount of DNA damage compared to the control. When evaluating whether a dose-dependent relationship was present, seventeen of the eighteen compounds led to greater DNA damage with increasing exposure concentrations. 2,3,7,8-TCDD was particularly potent, inducing DNA damage in virtually all cells at 1 µM. In conclusion, most of the toxins evaluated using the comet assay showed potential to induce DNA damage in hematopoietic cells, and the genotoxic effects were dose-dependent.

12.
Ann R Coll Surg Engl ; 103(7): 471-477, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33851878

RESUMO

INTRODUCTION: Diverticular disease is one of the most frequent reasons for attending emergency departments and surgical causes of hospital admission. In the past decade, many surgical and gastroenterological societies have published guidelines for the management of diverticular disease. The aim of the present study was to appraise the methodological quality of these guidelines using the Appraisal of Guidelines Research and Evaluation II (AGREE II) tool. METHODS: PubMed, Embase, Cochrane Library and Google Scholar databases were searched systematically. The methodological quality of the guidelines was appraised independently by five appraisers using the AGREE II instrument. FINDINGS: A systematic search of the literature identified 12 guidelines. The median overall score of all guidelines was 68%. Across all guidelines, the highest score of 85% was demonstrated in the domain 'Scope and purpose'. The domains 'Clarity and presentation' and 'Editorial independence' both scored a median of 72%. The lowest scores were demonstrated in the domains 'Stakeholder involvement' and 'Applicability' at 46% and 40%, respectively. Overall, the National Institute for Health and Care Excellence (NICE) guidelines performed consistently well, scoring 100% in five of six domains; NICE was one of the few guidelines that specifically reported stakeholder involvement, scoring 97%. Generally, the domain of 'Stakeholder involvement' ranked poorly with seven of twelve guidelines scoring below 50%, with the worst score in this domain demonstrated by Danish guidelines at 25%. CONCLUSION: Six of twelve guidelines (NICE, American Society of Colon & Rectal Surgeons (ASCRS), European Society of Coloproctology (ESCP), American Gastroenterological Association, German Society of Gastroenterology/German Society for General and Visceral Surgery (German), Netherlands Society of Surgery) scored above 70%. Only three, NICE, ASCRS and ESCP, scored above 75% and were voted unanimously by the appraisers for use as they are. Therefore, use of AGREE II may help improve the methodological quality of guidelines and their future updates.


Assuntos
Doenças Diverticulares/terapia , Gastroenterologia/normas , Guias de Prática Clínica como Assunto , Sociedades Médicas/normas , Doenças Diverticulares/diagnóstico , Medicina Baseada em Evidências/métodos , Medicina Baseada em Evidências/normas , Gastroenterologia/métodos , Humanos , Participação dos Interessados
13.
Ann R Coll Surg Engl ; 103(4): 235-244, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33682486

RESUMO

INTRODUCTION: The debate on the best surgical management strategy for acute malignant left-sided colonic obstruction is ongoing. Decompressing colostomy (DC) and stenting as a bridge to surgery (SBTS) are the currently proposed alternative approaches to emergency colectomy (EC). However, the results of a traditional meta-analysis were inconclusive. Therefore, a network meta-analysis (NMA) was conducted to compare the three approaches for acute left-sided colonic obstruction. METHODS: A systematic literature search of Embase, PubMed, Google Scholar and the Cochrane library was performed. A traditional meta-analysis and subsequent NMA were conducted. FINDINGS: A significantly greater number of primary anastomoses were performed in the DC cohort than in the EC and SBTS cohorts. The 90-day mortality rate was significantly lower in the DC cohort than in the EC and SBTS cohorts. Higher costs were associated with the SBTS cohort (by US$2,000) than with the EC cohort. The locoregional recurrence rate was higher for the SBTS cohort than for the EC cohort. CONCLUSIONS: Evidence from the first NMA suggests there may be some clinical advantages associated with DC as an alternative approach to the EC and SBTS approaches for adequately selected patients with malignant large bowel obstruction.


Assuntos
Colectomia , Doenças do Colo/cirurgia , Neoplasias do Colo/complicações , Colostomia , Obstrução Intestinal/cirurgia , Stents , Doença Aguda , Doenças do Colo/etiologia , Humanos , Obstrução Intestinal/etiologia , Metanálise em Rede
16.
J Laryngol Otol ; : 1-6, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33168109

RESUMO

OBJECTIVES: As the pathophysiology of COVID-19 emerges, this paper describes dysphagia as a sequela of the disease, including its diagnosis and management, hypothesised causes, symptomatology in relation to viral progression, and concurrent variables such as intubation, tracheostomy and delirium, at a tertiary UK hospital. RESULTS: During the first wave of the COVID-19 pandemic, 208 out of 736 patients (28.9 per cent) admitted to our institution with SARS-CoV-2 were referred for swallow assessment. Of the 208 patients, 102 were admitted to the intensive treatment unit for mechanical ventilation support, of which 82 were tracheostomised. The majority of patients regained near normal swallow function prior to discharge, regardless of intubation duration or tracheostomy status. CONCLUSION: Dysphagia is prevalent in patients admitted either to the intensive treatment unit or the ward with COVID-19 related respiratory issues. This paper describes the crucial role of intensive swallow rehabilitation to manage dysphagia associated with this disease, including therapeutic respiratory weaning for those with a tracheostomy.

20.
MMWR Morb Mortal Wkly Rep ; 69(20): 632-635, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32437338

RESUMO

On March 16, 2020, the day that national social distancing guidelines were released (1), the Arkansas Department of Health (ADH) was notified of two cases of coronavirus disease 2019 (COVID-19) from a rural county of approximately 25,000 persons; these cases were the first identified in this county. The two cases occurred in a husband and wife; the husband is the pastor at a local church (church A). The couple (the index cases) attended church-related events during March 6-8, and developed nonspecific respiratory symptoms and fever on March 10 (wife) and 11 (husband). Before his symptoms had developed, the husband attended a Bible study group on March 11. Including the index cases, 35 confirmed COVID-19 cases occurred among 92 (38%) persons who attended events held at church A during March 6-11; three patients died. The age-specific attack rates among persons aged ≤18 years, 19-64 years, and ≥65 years were 6.3%, 59.4%, and 50.0%, respectively. During contact tracing, at least 26 additional persons with confirmed COVID-19 cases were identified among community members who reported contact with church A attendees and likely were infected by them; one of the additional persons was hospitalized and subsequently died. This outbreak highlights the potential for widespread transmission of SARS-CoV-2, the virus that causes COVID-19, both at group gatherings during church events and within the broader community. These findings underscore the opportunity for faith-based organizations to prevent COVID-19 by following local authorities' guidance and the U.S. Government's Guidelines: Opening Up America Again (2) regarding modification of activities to prevent virus transmission during the COVID-19 pandemic.


Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Organizações Religiosas , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Adolescente , Adulto , Idoso , Arkansas/epidemiologia , COVID-19 , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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