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2.
Acad Med ; 99(3): 310-316, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38039985

RESUMEN

PURPOSE: Clinical practice variability is characterized by 2 or more clinicians making different treatment decisions despite encountering a similar case. This study explores how medical residents and fellows experience and interpret intersupervisor clinical practice variability and how these variations influence learning. METHOD: Seventeen senior residents or fellows in internal medicine, hematology, or thrombosis medicine (postgraduate year 3 or above) participated in semistructured interviews after a clinical rotation in thrombosis medicine from December 2019 to March 2021. Data collection and analysis occurred iteratively and concurrently in a manner consistent with constructivist grounded theory. Variation theory was used to guide the development of some interview questions. A central tenet of this theory is that learning occurs by experiencing 3 sequential patterns of variation: contrast, generalization, and fusion. Participants were recruited purposively with respect to specialty until theoretical sufficiency was reached. RESULTS: Clinical practice variability was experienced by all participants. Residents and fellows attributed practice variability to intrinsic differences among supervisors; interinstitutional differences; selection and interpretation of evidence; patient preferences, priorities, and fears; and their own participation in the decision-making process. Clinical practice variability helped residents and fellows discern key features of cases that influenced decision-making (contrast), group similar cases so that the appropriate evidence could be applied (generalization), and develop attitudes consistent with providing individualized patient care (fusion). Observing practice variability was more helpful for fifth- and sixth-year residents and less helpful for third- and fourth-year residents. CONCLUSIONS: Clinical practice variability helped residents and fellows discern critical aspects, group similar patients, and practice individualized medicine. Future research should characterize how clinical practice variability influences learning across the spectrum of training, how supervisors could encourage learning from practice variability, and how curricula could be modified to allow learners greater opportunity to reflect on and consolidate the practice differences they observe.


Asunto(s)
Internado y Residencia , Trombosis , Humanos , Educación de Postgrado en Medicina/métodos , Curriculum , Medicina Interna , Competencia Clínica
3.
Res Pract Thromb Haemost ; 6(6): e12795, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36186106

RESUMEN

Intravenous thrombolysis is a standard of care treatment for patients with acute ischemic stroke. Tissue plasminogen activator (tPA) has been the main thrombolytic agent used since the publication of the seminal National Institutes of Neurological Disorders and Stroke trial in 1995. There is now mounting evidence to support the routine use of Tenecteplase (TNK) to treat acute ischemic stroke. TNK is a genetically modified tPA with higher fibrin specificity, longer half-life, and reduced systemic coagulopathy. In this illustrated review, we compare the indications, doses, mechanisms of action, efficacy and safety of TNK and tPA. We provide an overview of published clinical trials studying TNK in acute ischemic stroke, including dose-escalation studies and head-to-head comparisons with tPA. Finally, we summarize current acute stroke guideline recommendations and suggest treatment algorithms to manage the two main complications of intravenous thrombolysis: symptomatic intracerebral hemorrhage and angioedema.

4.
Blood Adv ; 6(17): 4975-4982, 2022 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-35748885

RESUMEN

BACKGROUND: COVID-19-related critical illness is associated with an increased risk of venous thromboembolism (VTE). OBJECTIVE: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about the use of anticoagulation for patients with COVID-19. METHODS: ASH formed a multidisciplinary guideline panel, including 3 patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline development process, including performing systematic evidence reviews (up to January 2022). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the GRADE approach to assess evidence and make recommendations, which were subject to public comment. This is an update to guidelines published in February 2021 and May 2021 as part of the living phase of these guidelines. RESULTS: The panel made 1 additional recommendation: a conditional recommendation for the use of prophylactic-intensity over therapeutic-intensity anticoagulation for patients with COVID-19-related critical illness who do not have suspected or confirmed VTE. The panel emphasized the need for an individualized assessment of thrombotic and bleeding risk. CONCLUSIONS: This conditional recommendation was based on very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials comparing different intensities of anticoagulation for patients with COVID-19-related critical illness.


Asunto(s)
COVID-19 , Hematología , Tromboembolia Venosa , Anticoagulantes/uso terapéutico , Enfermedad Crítica/terapia , Humanos , Estados Unidos , Tromboembolia Venosa/tratamiento farmacológico , Tromboembolia Venosa/etiología , Tromboembolia Venosa/prevención & control
5.
Blood Adv ; 6(17): 4915-4923, 2022 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-35503027

RESUMEN

BACKGROUND: COVID-19-related acute illness is associated with an increased risk of venous thromboembolism (VTE). OBJECTIVE: These evidence-based guidelines from the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in making decisions about the use of anticoagulation in patients with COVID-19. METHODS: ASH formed a multidisciplinary guideline panel that included patient representatives and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process and performed systematic evidence reviews (through November 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations, which were subject to public comment. This is an update to guidelines published in February 2021 as part of the living phase of these guidelines. RESULTS: The panel made one additional recommendation. The panel issued a conditional recommendation in favor of therapeutic-intensity over prophylactic-intensity anticoagulation in patients with COVID-19-related acute illness who do not have suspected or confirmed VTE. The panel emphasized the need for an individualized assessment of risk of thrombosis and bleeding. The panel also noted that heparin (unfractionated or low molecular weight) may be preferred because of a preponderance of evidence with this class of anticoagulants. CONCLUSION: This conditional recommendation was based on very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials comparing different intensities of anticoagulation in patients with COVID-19-related acute illness.


Asunto(s)
COVID-19 , Hematología , Tromboembolia Venosa , Enfermedad Aguda , Anticoagulantes/uso terapéutico , Humanos , Estados Unidos , Tromboembolia Venosa/tratamiento farmacológico , Tromboembolia Venosa/etiología , Tromboembolia Venosa/prevención & control
6.
Adv Mater ; 34(26): e2200574, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35419882

RESUMEN

Here, a new family of 2D transition metal carbo-chalcogenides (TMCCs) is reported, which can be considered a combination of two well-known families, TM carbides (MXenes) and TM dichalcogenides (TMDCs), at the atomic level. Single sheets are successfully obtained from multilayered Nb2 S2 C and Ta2 S2 C using electrochemical lithiation followed by sonication in water. The parent multilayered TMCCs are synthesized using a simple, scalable solid-state synthesis followed by a topochemical reaction. Superconductivity transition is observed at 7.55 K for Nb2 S2 C. The delaminated Nb2 S2 C outperforms both multilayered Nb2 S2 C and delaminated NbS2 as an electrode material for Li-ion batteries. Ab initio calculations predict the elastic constant of TMCC to be over 50% higher than that of TMDC.

7.
Blood Adv ; 6(2): 664-671, 2022 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-34727173

RESUMEN

BACKGROUND: COVID-19-related acute illness is associated with an increased risk of venous thromboembolism (VTE). OBJECTIVE: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about the use of anticoagulation for thromboprophylaxis in patients with COVID-19 who do not have confirmed or suspected VTE. METHODS: ASH formed a multidisciplinary guideline panel, including 3 patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including performing systematic evidence reviews (up to March 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the grading of recommendations assessment, development, and evaluation (GRADE) approach to assess evidence and make recommendations, which were subject to public comment. RESULTS: The panel agreed on 1 additional recommendation. The panel issued a conditional recommendation against the use of outpatient anticoagulant prophylaxis in patients with COVID-19 who are discharged from the hospital and who do not have suspected or confirmed VTE or another indication for anticoagulation. CONCLUSIONS: This recommendation was based on very low certainty in the evidence, underscoring the need for high-quality randomized controlled trials assessing the role of postdischarge thromboprophylaxis. Other key research priorities include better evidence on assessing risk of thrombosis and bleeding outcomes in patients with COVID-19 after hospital discharge.


Asunto(s)
COVID-19 , Hematología , Tromboembolia Venosa , Cuidados Posteriores , Anticoagulantes/efectos adversos , Medicina Basada en la Evidencia , Humanos , Alta del Paciente , SARS-CoV-2 , Estados Unidos , Tromboembolia Venosa/etiología , Tromboembolia Venosa/prevención & control
8.
BMJ ; 375: n2400, 2021 10 14.
Artículo en Inglés | MEDLINE | ID: mdl-34649864

RESUMEN

OBJECTIVE: To evaluate the effects of therapeutic heparin compared with prophylactic heparin among moderately ill patients with covid-19 admitted to hospital wards. DESIGN: Randomised controlled, adaptive, open label clinical trial. SETTING: 28 hospitals in Brazil, Canada, Ireland, Saudi Arabia, United Arab Emirates, and US. PARTICIPANTS: 465 adults admitted to hospital wards with covid-19 and increased D-dimer levels were recruited between 29 May 2020 and 12 April 2021 and were randomly assigned to therapeutic dose heparin (n=228) or prophylactic dose heparin (n=237). INTERVENTIONS: Therapeutic dose or prophylactic dose heparin (low molecular weight or unfractionated heparin), to be continued until hospital discharge, day 28, or death. MAIN OUTCOME MEASURES: The primary outcome was a composite of death, invasive mechanical ventilation, non-invasive mechanical ventilation, or admission to an intensive care unit, assessed up to 28 days. The secondary outcomes included all cause death, the composite of all cause death or any mechanical ventilation, and venous thromboembolism. Safety outcomes included major bleeding. Outcomes were blindly adjudicated. RESULTS: The mean age of participants was 60 years; 264 (56.8%) were men and the mean body mass index was 30.3 kg/m2. At 28 days, the primary composite outcome had occurred in 37/228 patients (16.2%) assigned to therapeutic heparin and 52/237 (21.9%) assigned to prophylactic heparin (odds ratio 0.69, 95% confidence interval 0.43 to 1.10; P=0.12). Deaths occurred in four patients (1.8%) assigned to therapeutic heparin and 18 patients (7.6%) assigned to prophylactic heparin (0.22, 0.07 to 0.65; P=0.006). The composite of all cause death or any mechanical ventilation occurred in 23 patients (10.1%) assigned to therapeutic heparin and 38 (16.0%) assigned to prophylactic heparin (0.59, 0.34 to 1.02; P=0.06). Venous thromboembolism occurred in two patients (0.9%) assigned to therapeutic heparin and six (2.5%) assigned to prophylactic heparin (0.34, 0.07 to 1.71; P=0.19). Major bleeding occurred in two patients (0.9%) assigned to therapeutic heparin and four (1.7%) assigned to prophylactic heparin (0.52, 0.09 to 2.85; P=0.69). CONCLUSIONS: In moderately ill patients with covid-19 and increased D-dimer levels admitted to hospital wards, therapeutic heparin was not significantly associated with a reduction in the primary outcome but the odds of death at 28 days was decreased. The risk of major bleeding appeared low in this trial. TRIAL REGISTRATION: ClinicalTrials.gov NCT04362085.


Asunto(s)
Anticoagulantes/uso terapéutico , COVID-19/mortalidad , COVID-19/terapia , Heparina/uso terapéutico , Hospitalización/estadística & datos numéricos , Respiración Artificial , Biomarcadores/sangre , Femenino , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Masculino , Persona de Mediana Edad , SARS-CoV-2 , Índice de Severidad de la Enfermedad
9.
Adv Med Educ Pract ; 12: 1153-1163, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34675742

RESUMEN

The paradigm of medical education is evolving with the introduction of competency-based medical education (CBME) and it is crucial that residency programs adapt. In this paper, we provide an overview of the current status of medical education in Hematology in Canada including models of training, assessment methods, anticipated challenges, and the effects of the COVID-19 pandemic. We will also discuss additional training that can be pursued after a Hematology residency, with a particular focus On Transfusion Medicine as it was one of the first programs to implement a competency-based curriculum. Finally, we explore the future directions of medical education in Hematology and Transfusion Medicine.

10.
Blood Adv ; 5(20): 3951-3959, 2021 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-34474482

RESUMEN

BACKGROUND: COVID-19-related critical illness is associated with an increased risk of venous thromboembolism (VTE). OBJECTIVE: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in making decisions about the use of anticoagulation for thromboprophylaxis in patients with COVID-19-related critical illness who do not have confirmed or suspected VTE. METHODS: ASH formed a multidisciplinary guideline panel that included 3 patient representatives and applied strategies to minimize potential bias from conflicts of interest. The McMaster University Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline development process by performing systematic evidence reviews (up to 5 March 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the GRADE approach to assess evidence and make recommendations, which were subject to public comment. This is an update on guidelines published in February 2021. RESULTS: The panel agreed on 1 additional recommendation. The panel issued a conditional recommendation in favor of prophylactic-intensity over intermediate-intensity anticoagulation in patients with COVID-19-related critical illness who do not have confirmed or suspected VTE. CONCLUSIONS: This recommendation was based on low certainty in the evidence, which underscores the need for additional high-quality, randomized, controlled trials comparing different intensities of anticoagulation in critically ill patients. Other key research priorities include better evidence regarding predictors of thrombosis and bleeding risk in critically ill patients with COVID-19 and the impact of nonanticoagulant therapies (eg, antiviral agents, corticosteroids) on thrombotic risk.


Asunto(s)
COVID-19 , Hematología , Tromboembolia Venosa , Anticoagulantes/efectos adversos , Enfermedad Crítica , Medicina Basada en la Evidencia , Humanos , SARS-CoV-2 , Estados Unidos , Tromboembolia Venosa/etiología , Tromboembolia Venosa/prevención & control
11.
medRxiv ; 2021 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-34268513

RESUMEN

BACKGROUND: Heparin, in addition to its anticoagulant properties, has anti-inflammatory and potential anti-viral effects, and may improve endothelial function in patients with Covid-19. Early initiation of therapeutic heparin could decrease the thrombo-inflammatory process, and reduce the risk of critical illness or death. METHODS: We randomly assigned moderately ill hospitalized ward patients admitted for Covid-19 with elevated D-dimer level to therapeutic or prophylactic heparin. The primary outcome was a composite of death, invasive mechanical ventilation, non-invasive mechanical ventilation or ICU admission. Safety outcomes included major bleeding. Analysis was by intention-to-treat. RESULTS: At 28 days, the primary composite outcome occurred in 37 of 228 patients (16.2%) assigned to therapeutic heparin, and 52 of 237 patients (21.9%) assigned to prophylactic heparin (odds ratio, 0.69; 95% confidence interval [CI], 0.43 to 1.10; p=0.12). Four patients (1.8%) assigned to therapeutic heparin died compared with 18 patients (7.6%) assigned to prophylactic heparin (odds ratio, 0.22; 95%-CI, 0.07 to 0.65). The composite of all-cause mortality or any mechanical ventilation occurred in 23 (10.1%) in the therapeutic heparin group and 38 (16.0%) in the prophylactic heparin group (odds ratio, 0.59; 95%-CI, 0.34 to 1.02). Major bleeding occurred in 2 patients (0.9%) with therapeutic heparin and 4 patients (1.7%) with prophylactic heparin (odds ratio, 0.52; 95%-CI, 0.09 to 2.85). CONCLUSIONS: In moderately ill ward patients with Covid-19 and elevated D-dimer level, therapeutic heparin did not significantly reduce the primary outcome but decreased the odds of death at 28 days. Trial registration numbers: NCT04362085 ; NCT04444700.

12.
Trials ; 22(1): 202, 2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33691765

RESUMEN

OBJECTIVES: To determine the effect of therapeutic anticoagulation, with low molecular weight heparin (LMWH) or unfractionated heparin (UFH, high dose nomogram), compared to standard care in hospitalized patients admitted for COVID-19 with an elevated D-dimer on the composite outcome of intensive care unit (ICU) admission, non-invasive positive pressure ventilation, invasive mechanical ventilation or death up to 28 days. TRIAL DESIGN: Open-label, parallel, 1:1, phase 3, 2-arm randomized controlled trial PARTICIPANTS: The study population includes hospitalized adults admitted for COVID-19 prior to the development of critical illness. Excluded individuals are those where the bleeding risk or risk of transfusion would generally be considered unacceptable, those already therapeutically anticoagulated and those who have already have any component of the primary composite outcome. Participants are recruited from hospital sites in Brazil, Canada, Ireland, Saudi Arabia, United Arab Emirates, and the United States of America. The inclusion criteria are: 1) Laboratory confirmed COVID-19 (diagnosis of SARS-CoV-2 via reverse transcriptase polymerase chain reaction as per the World Health Organization protocol or by nucleic acid based isothermal amplification) prior to hospital admission OR within first 5 days (i.e. 120 hours) after hospital admission; 2) Admitted to hospital for COVID-19; 3) One D-dimer value above the upper limit of normal (ULN) (within 5 days (i.e. 120 hours) of hospital admission) AND EITHER: a. D-Dimer ≥2 times ULN OR b. D-Dimer above ULN and Oxygen saturation ≤ 93% on room air; 4) > 18 years of age; 5) Informed consent from the patient (or legally authorized substitute decision maker). The exclusion criteria are: 1) pregnancy; 2) hemoglobin <80 g/L in the last 72 hours; 3) platelet count <50 x 109/L in the last 72 hours; 4) known fibrinogen <1.5 g/L (if testing deemed clinically indicated by the treating physician prior to the initiation of anticoagulation); 5) known INR >1.8 (if testing deemed clinically indicated by the treating physician prior to the initiation of anticoagulation); 6) patient already prescribed intermediate dosing of LMWH that cannot be changed (determination of what constitutes an intermediate dose is to be at the discretion of the treating clinician taking the local institutional thromboprophylaxis protocol for high risk patients into consideration); 7) patient already prescribed therapeutic anticoagulation at the time of screening [low or high dose nomogram UFH, LMWH, warfarin, direct oral anticoagulant (any dose of dabigatran, apixaban, rivaroxaban, edoxaban)]; 8) patient prescribed dual antiplatelet therapy, when one of the agents cannot be stopped safely; 9) known bleeding within the last 30 days requiring emergency room presentation or hospitalization; 10) known history of a bleeding disorder of an inherited or active acquired bleeding disorder; 11) known history of heparin-induced thrombocytopenia; 12) known allergy to UFH or LMWH; 13) admitted to the intensive care unit at the time of screening; 14) treated with non-invasive positive pressure ventilation or invasive mechanical ventilation at the time of screening; 15) Imminent death according to the judgement of the most responsible physician; 16) enrollment in another clinical trial of antithrombotic therapy involving hospitalized patients. INTERVENTION AND COMPARATOR: Intervention: Therapeutic dose of LMWH (dalteparin, enoxaparin, tinzaparin) or high dose nomogram of UFH. The choice of LMWH versus UFH will be at the clinician's discretion and dependent on local institutional supply. Comparator: Standard care [thromboprophylactic doses of LMWH (dalteparin, enoxaparin, tinzaparin, fondaparinux)] or UFH. Administration of LMWH, UFH or fondaparinux at thromboprophylactic doses for acutely ill hospitalized medical patients, in the absence of contraindication, is generally considered standard care. MAIN OUTCOMES: The primary composite outcome of ICU admission, non-invasive positive pressure ventilation, invasive mechanical ventilation or death at 28 days. Secondary outcomes include (evaluated up to day 28): 1. All-cause death 2. Composite of ICU admission or all-cause death 3. Composite of mechanical ventilation or all-cause death 4. Major bleeding as defined by the ISTH Scientific and Standardization Committee (ISTH-SSC) recommendation; 5. Red blood cell transfusion (>1 unit); 6. Transfusion of platelets, frozen plasma, prothrombin complex concentrate, cryoprecipitate and/or fibrinogen concentrate; 7. Renal replacement therapy; 8. Hospital-free days alive; 9. ICU-free days alive; 10. Ventilator-free days alive; 11. Organ support-free days alive; 12. Venous thromboembolism (defined as symptomatic or incidental, suspected or confirmed via diagnostic imaging and/or electrocardiogram where appropriate); 13. Arterial thromboembolism (defined as suspected or confirmed via diagnostic imaging and/or electrocardiogram where appropriate); 14. Heparin induced thrombocytopenia; 15. Trajectories of COVID-19 disease-related coagulation and inflammatory biomarkers. RANDOMISATION: Randomisation will be stratified by site and age (>65 versus ≤65 years) using a 1:1 computer-generated random allocation sequence with variable block sizes. Randomization will occur within the first 5 days (i.e. 120 hours) of participant hospital admission. However, it is recommended that randomization occurs as early as possible after hospital admission. Central randomization using an interactive web response system will ensure allocation concealment. BLINDING (MASKING): No blinding involved. This is an open-label trial. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): 462 patients (231 per group) are needed to detect a 15% risk difference, from 50% in the control group to 35% in the experimental group, with power of 90% at a two-sided alpha of 0.05. TRIAL STATUS: Protocol Version Number 1.4. Recruitment began on May 11th, 2020. Recruitment is expected to be completed March 2022. Recruitment is ongoing. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04362085 Date of Trial Registration: April 24, 2020 FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest of expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.


Asunto(s)
Anticoagulantes/uso terapéutico , Trastornos de la Coagulación Sanguínea/tratamiento farmacológico , Tratamiento Farmacológico de COVID-19 , Trastornos de la Coagulación Sanguínea/sangre , Trastornos de la Coagulación Sanguínea/complicaciones , COVID-19/sangre , COVID-19/complicaciones , COVID-19/fisiopatología , Ensayos Clínicos Fase III como Asunto , Productos de Degradación de Fibrina-Fibrinógeno/metabolismo , Heparina/uso terapéutico , Heparina de Bajo-Peso-Molecular/uso terapéutico , Hospitalización , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Ventilación no Invasiva/estadística & datos numéricos , Ensayos Clínicos Pragmáticos como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Respiración Artificial/estadística & datos numéricos , SARS-CoV-2
13.
Nano Lett ; 21(6): 2444-2452, 2021 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-33651617

RESUMEN

Silver, king among plasmonic materials, features low inelastic absorption in the visible-infrared (vis-IR) spectral region compared to other metals. In contrast, copper is commonly regarded as too lossy for actual applications. Here, we demonstrate vis-IR plasmons with quality factors >60 in long copper nanowires (NWs), as determined by electron energy-loss spectroscopy. We explain this result by noticing that most of the electromagnetic energy in these plasmons lies outside the metal, thus becoming less sensitive to inelastic absorption. Measurements for silver and copper NWs of different diameters allow us to elucidate the relative importance of radiative and nonradiative losses in plasmons spanning a wide spectral range down to <20 meV. Thermal population of such low-energy modes becomes significant and generates electron energy gains associated with plasmon absorption, rendering an experimental determination of the NW temperature. Copper is therefore emerging as an attractive, cheap, abundant material platform for high-quality plasmonics in elongated nanostructures.

14.
Adv Sci (Weinh) ; 8(3): 2003656, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33552874

RESUMEN

Enhancing both the energy storage and power capabilities of electrochemical capacitors remains a challenge. Herein, Ti3C2T z MXene is mixed with MoO3 nanobelts in various mass ratios and the mixture is used to vacuum filter binder free, open, flexible, and free-standing films. The conductive Ti3C2T z flakes bridge the nanobelts, facilitating electron transfer; the randomly oriented, and interconnected, MoO3 nanobelts, in turn, prevent the restacking of the Ti3C2T z nanosheets. Benefitting from these advantages, a MoO3/Ti3C2T z film with a 8:2 mass ratio exhibits high gravimetric/volumetric capacities with good cyclability, namely, 837 C g-1 and 1836 C cm-3 at 1 A g-1 for an ≈ 10 µm thick film; and 767 C g-1 and 1664 C cm-3 at 1 A g-1 for ≈ 50 µm thick film. To further increase the energy density, hybrid capacitors are fabricated with MoO3/Ti3C2T z films as the negative electrodes and nitrogen-doped activated carbon as the positive electrodes. This device delivers maximum gravimetric/volumetric energy densities of 31.2 Wh kg-1 and 39.2 Wh L-1, respectively. The cycling stability of 94.2% retention ratio after 10 000 continuous charge/discharge cycles is also noteworthy. The high energy density achieved in this work can pave the way for practical applications of MXene-containing materials in energy storage devices.

15.
Blood Adv ; 5(3): 872-888, 2021 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-33560401

RESUMEN

BACKGROUND: Coronavirus disease 2019 (COVID-19)-related critical illness and acute illness are associated with a risk of venous thromboembolism (VTE). OBJECTIVE: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about the use of anticoagulation for thromboprophylaxis for patients with COVID-19-related critical illness and acute illness who do not have confirmed or suspected VTE. METHODS: ASH formed a multidisciplinary guideline panel and applied strict management strategies to minimize potential bias from conflicts of interest. The panel included 3 patient representatives. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic evidence reviews (up to 19 August 2020). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment. RESULTS: The panel agreed on 2 recommendations. The panel issued conditional recommendations in favor of prophylactic-intensity anticoagulation over intermediate-intensity or therapeutic-intensity anticoagulation for patients with COVID-19-related critical illness or acute illness who do not have confirmed or suspected VTE. CONCLUSIONS: These recommendations were based on very low certainty in the evidence, underscoring the need for high-quality, randomized controlled trials comparing different intensities of anticoagulation. They will be updated using a living recommendation approach as new evidence becomes available.


Asunto(s)
Anticoagulantes/uso terapéutico , COVID-19/patología , Tromboembolia Venosa/tratamiento farmacológico , COVID-19/complicaciones , COVID-19/virología , Enoxaparina/uso terapéutico , Medicina Basada en la Evidencia , Guías como Asunto , Humanos , SARS-CoV-2/aislamiento & purificación , Sociedades Médicas , Tromboembolia Venosa/complicaciones
16.
Nanoscale Adv ; 3(23): 6689-6695, 2021 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-36132662

RESUMEN

The construction of nanocomposite electrodes based on 2D materials is an efficient route for property enrichment and for exploitation of constituent 2D materials. Herein, a flexible Mo1.33C i-MXene/MoS2/graphene (MOMG) composite electrode is constructed, utilizing an environment-friendly method for high-quality graphene and MoS2 synthesis. The presence of graphene and MoS2 between MXene sheets limits the commonly observed restacking, increases the interlayer spacing, and facilitates the ionic and electronic conduction. The as-prepared MOMG electrode delivers a volumetric capacitance of 1600 F cm-3 (450 F g-1) at the scan rate of 2 mV s-1 and retains 96% of the initial capacitance after 15 000 charge/discharge cycles (10 A g-1). The current work demonstrates that the construction of nanocomposite electrodes is a promising route towards property enhancement for energy storage applications.

18.
Kidney Int Rep ; 5(2): 159-164, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32043029

RESUMEN

INTRODUCTION: Studies have shown that achieving a time in therapeutic range (TTR) for warfarin of greater than 60% is associated with a lower risk of bleeding. However, many patients on hemodialysis (HD) do not achieve this target. METHODS: We audited TTR achievement at the in-center HD unit of our hospital in 2017 and found that only 40% of patients had achieved a TTR >60%. We aimed to improve the percentage of HD patients achieving target TTR within 2 years. We reported each patient's individualized trend in quarterly TTR to their primary warfarin prescriber as an audit-feedback report. These reports were generated, disseminated, and subsequently improved following a series of plan-do-study-act cycles. We then used statistical process control to assess for changes in the percentage of HD patients achieving target TTR over time. RESULTS: In the primary analysis, 28 patients were included in the baseline period, and 46 were included in the intervention period. At baseline, the percentage of patients achieving a TTR >60% varied between 33% and 45% (mean ± SD, 40% ± 5%); post-intervention, this metric improved and varied between 52% and 71% (mean ± SD, 61% ± 8%). In time-series analysis, there was evidence of statistically significant variation between the 2 periods and evidence of sustained improvement. CONCLUSIONS: A quality improvement program consisting of an audit-feedback report that raises awareness of the quality gap in TTR achievement can result in substantial improvement in the safe and efficacious administration of warfarin to patients receiving maintenance hemodialysis.

19.
Int J Radiat Oncol Biol Phys ; 107(1): 136-142, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-31987962

RESUMEN

PURPOSE: Dose-escalated stereotactic ablative radiotherapy (SABR) to the whole prostate may be associated with better outcomes but has a risk of increased toxicity. An alternative approach is to focally boost the dominant intraprostatic lesion (DIL) seen on magnetic resonance imaging. We report the toxicity and quality-of-life (QOL) outcomes of 2 phase 2 trials of prostate and pelvic SABR, with or without a simultaneous DIL boost. METHODS AND MATERIALS: The first trial treated patients with high-risk prostate cancer to a dose of 40 Gy to the prostate and 25 Gy to the pelvis in 5 fractions. The second trial treated patients with intermediate-risk and high-risk prostate cancer to a dose of 35 Gy to the prostate, 25 Gy to the pelvis, and a DIL boost up to 50 Gy in 5 fractions. Acute toxicities, late toxicities, and QOL were assessed. RESULTS: Thirty patients were enrolled in each trial. In the focal boost cohort, the median DIL D90% was 48.3 Gy. There was no significant difference in acute grade ≥2 gastrointestinal or genitourinary toxicity between the 2 trials or in cumulative worst late gastrointestinal or genitourinary toxicity up to 24 months. There was no significant difference in QOL domain scores or minimally clinical important change between the 2 trials. CONCLUSIONS: Prostate and pelvic SABR with a simultaneous DIL boost was feasible. Acute grade ≥2 toxicity, late toxicity, and QOL seemed to be comparable to a cohort that did not receive a focal boost. Further follow-up will be required to assess long-term outcomes, and randomized data are required to confirm these findings.


Asunto(s)
Neoplasias de la Próstata/patología , Neoplasias de la Próstata/radioterapia , Calidad de Vida , Radiocirugia/efectos adversos , Seguridad , Anciano , Anciano de 80 o más Años , Humanos , Masculino , Persona de Mediana Edad , Riesgo , Factores de Tiempo
20.
Acad Med ; 95(2): 275-282, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31517680

RESUMEN

PURPOSE: To characterize how residents employ rhetorical appeals (i.e., the strategic use of communication to achieve specifiable goals) when discussing unnecessary diagnostic tests with patients. METHOD: In 2015, senior hematology residents from 10 Canadian universities participating in a national formative objective structured clinical examination (OSCE) completed a resource stewardship communication station. In this communication scenario, a standardized patient (SP) portrayed a patient requesting unnecessary thrombophilia testing following early pregnancy loss. The authors performed a thematic analysis of audio transcripts using a qualitative description approach to identify residents' rhetorical appeals to logic (rational appeals), credibility, and emotion. RESULTS: For persuasive communication, residents (n = 27) relied primarily on rational appeals that fit into 3 categories (with themes) focused on medical evidence (poor utility, professional guidelines and recommendations), avoidance of harm (insurance implications, unnecessary or potentially harmful interventions, patient anxiety), and reassurance to patient (normalizing, clinical pretest probability, criteria for reconsidering testing). Appeals to credibility and emotion were rarely used. CONCLUSIONS: In an OSCE setting, residents relied predominantly on rational appeals when engaging SPs in conversations about unnecessary tests. These observations yield insights into how recent emphasis within residency education on appropriate test utilization may manifest when residents put recommendations into practice in conversations with patients. This study's framework of rational appeals may be helpful in designing communication curricula about unnecessary testing. Future studies should explore rhetoric about unnecessary testing in the clinical environment, strategies to teach and coach residents leading these conversations, and patients' preferences and responses to different appeals.


Asunto(s)
Hematología/educación , Relaciones Médico-Paciente , Procedimientos Innecesarios/psicología , Aborto Espontáneo/psicología , Canadá , Competencia Clínica , Humanos , Internado y Residencia , Guías de Práctica Clínica como Asunto , Trombofilia/diagnóstico
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