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1.
Artigo em Inglês | MEDLINE | ID: mdl-39278616

RESUMO

OBJECTIVES: The task of writing structured content reviews and guidelines has grown stronger and more complex. We propose to go beyond search tools, toward curation tools, by automating time-consuming and repetitive steps of extracting and organizing information. METHODS: SciScribe is built as an extension of IBM's Deep Search platform, which provides document processing and search capabilities. This platform was used to ingest and search full-content publications from PubMed Central (PMC) and official, structured records from the ClinicalTrials and OpenPayments databases. Author names and NCT numbers, mentioned within the publications, were used to link publications to these official records as context. Search strategies involve traditional keyword-based search as well as natural language question and answering via large language models (LLMs). RESULTS: SciScribe is a web-based tool that helps accelerate literature reviews through key features: 1. Accumulate a personal collection from publication sources, such as PMC or other sources; 2. Incorporate contextual information from external databases into the presented papers, promoting a more informed assessment by readers. 3. Semantic question and answering of a document to quickly assess relevance and hierarchical organization. 4. Semantic question answering for each document within a collection, collated into tables. CONCLUSIONS: Emergent language processing techniques open new avenues to accelerate and enhance the literature review process, for which we have demonstrated a use case implementation within cardiac surgery. SciScribe automates and accelerates this process, mitigates errors associated with repetition and fatigue, as well as contextualizes results by linking relevant external data sources, instantaneously.

2.
J Acad Nutr Diet ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39029585

RESUMO

It is the position of the Academy of Nutrition and Dietetics and the American Council on Exercise that nutrition and physical activity interventions delivered by qualified nutrition and exercise practitioners, within their scopes of practice, can improve lifestyle behaviors and cardiometabolic risk factors for adults in the general population. Effective interventions require client-centered, evidence-based care provided by skilled practitioners using inclusive, dynamic methods, and collaboration with an interprofessional team, as appropriate. Increased access to evidence-based nutrition and physical activity interventions is necessary to improve public health and should be a target for policymakers, health care systems, and practitioners. Adults who attain a nutritious diet and adequate physical activity have improved overall health compared with their counterparts. However, most adults do not meet population recommendations. Qualified nutrition and exercise practitioners can collaborate with clients and interprofessional teams to provide nutrition and physical activity interventions and improve outcomes. However, recent guidelines have identified a need for guidance on best practices for delivering behavioral lifestyle counseling, referring to other practitioners, and improving access to disease prevention services. This Academy of Nutrition and Dietetics Position Paper aims to address common barriers for nutrition and exercise practitioners providing nutrition and physical activity interventions for adults in the general population, and best practices for overcoming these barriers. Collective action from interprofessional practitioners and implementation partners can increase access to high-quality, individualized services to prevent disease and improve health and well-being on a population level. This position was approved in July 2024 and will remain in effect until December 31, 2031.

3.
Ann Thorac Surg ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38871162

RESUMO

In this invited expert review, we focus on evolving lifetime management strategies for adolescents and young adults with congenital aortic valve disease, acknowledging that these patients often require multiple interventions during their lifetime. Our goal is to preserve the native aortic valve when feasible. Leveraging advanced multimodality imaging, a detailed assessment of the aortic valve and root complex can be obtained, and a surgically approach tailored to an individual patient's anatomy and pathology can be used. In turn, aortic valve repair and reconstruction can be offered to a greater number of patients, either as a definitive strategy or as a component of a staged strategy to delay the need for aortic valve replacement until later in life when more options are available.

4.
J Cardiovasc Dev Dis ; 11(2)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38392282

RESUMO

Congenital heart defects (CHDs) are complex conditions affecting the heart and/or great vessels that are present at birth. These defects occur in approximately 9 in every 1000 live births. From diagnosis to intervention, care has dramatically improved over the last several decades. Patients with CHDs are now living well into adulthood. However, there are factors that have been associated with poor outcomes across the lifespan of these patients. These factors include sociodemographic and socioeconomic positions. This commentary examined the disparities and solutions within the evolution of CHD care in the United States.

6.
J Acad Nutr Diet ; 123(8): 1215-1237.e5, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37061182

RESUMO

A nutritious diet and adequate physical activity vitally contribute to disease prevention, but most adults do not meet population-based dietary and physical activity recommendations. Qualified nutrition and exercise practitioners can address challenges to adopting healthy lifestyle behaviors by providing consistent, individualized, and evidence-based education and programming within their professional scopes of practice to improve client outcomes. The objective of this evidence-based practice guideline is to inform practice decisions for nutrition and exercise practitioners providing nutrition and physical activity interventions for adults who are healthy or have cardiometabolic risk factors, but no diagnosed disease. Evidence from a systematic review was translated to practice recommendations using an evidence-to-decision framework by an interdisciplinary team of nutrition and exercise practitioners and researchers. This evidence-based practice guideline does not provide specific dietary or physical activity recommendations but rather informs nutrition and exercise practitioners how they may utilize existing guidelines for the general population to individualize programming for a range of clients. This evidence-based practice guideline provides widely applicable recommendation statements and a detailed framework to help practitioners implement the recommendations into practice. Common barriers and facilitators encountered when delivering nutrition and physical activity interventions, such as adherence to professional scopes of practice; methods to support behavior change; and methods to support inclusion, diversity, equity, and access, are discussed. Nutrition and exercise practitioners can consistently provide individualized, practical, and evidence-based interventions by seeking to understand their clients' needs, circumstances, and values and by co-creating interventions with the client and their allied health team.


Assuntos
Dietética , Adulto , Humanos , Exercício Físico , Dieta , Estado Nutricional , Prática Clínica Baseada em Evidências
7.
Vasc Endovascular Surg ; 57(7): 771-775, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37058450

RESUMO

To date, emergent total endovascular aortic arch repair has not been described in the literature. We present a 67-year-old female with a poorly differentiated posterior mediastinal sarcoma. Imaging obtained was concerning for intravascular extension of the tumor into the thoracic aorta. While awaiting radiation therapy, the patient complained of worsening chest and arm pain, vital signs demonstrating tachypnea and hypoxia. Subsequent imaging revealed an increase in vascular erosion, concerning for a contained rupture, with complete obliteration of the left mainstem bronchus. The patient was emergently taken for percutaneous endovascular repair of her aortic arch. A three-vessel physician modified fenestrated graft was created and deployed with concurrent stenting of the innominate, left carotid, and left subclavian arteries. Interval computed tomography angiography revealed patency in all stented vessels, with no endoleak and no evidence of pseudoaneurysm. The patient was able to undergo chemotherapy with favorable decrease in tumor burden. Total endovascular aortic arch repair, when planned carefully, is an attractive option in high-risk patients who are otherwise not ideally suited for open total arch replacement.


Assuntos
Falso Aneurisma , Ruptura Aórtica , Humanos , Feminino , Idoso , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/cirurgia , Resultado do Tratamento , Ruptura Aórtica/diagnóstico por imagem , Ruptura Aórtica/cirurgia , Tórax
8.
Pediatr Cardiol ; 2023 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-36869913

RESUMO

Patients born with obstructed total anomalous pulmonary venous return have a high risk of morbidity and mortality in the neonatal period, which only increases when combined with single ventricle physiology and non-cardiac congenital anomalies such as heterotaxy syndrome. Despite advances in management of congenital heart disease, surgery within the first weeks of life to repair the pulmonary venous connection and establish pulmonary blood flow with a systemic-to-pulmonary shunt has historically led to disappointing outcomes. A multidisciplinary approach with pediatric interventional cardiology and cardiac surgery is required to reduce morbidity and mortality in this extremely high-risk patient population. Extending the time between birth and cardiac surgery can lessen postoperative complications and mortality risk, especially in patients with abnormal thoracoabdominal relationships. Our team was able to successfully utilize transcatheter stent placement in a vertical vein and patent ductus arteriosus to delay and stage cardiac surgeries in an infant born with obstructed total anomalous pulmonary venous return, unbalanced atrioventricular septal defect with pulmonary atresia and heterotaxy, thus reducing the morbidity and mortality associated with this diagnosis.

9.
Ann Thorac Surg ; 115(3): 771-777, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35934069

RESUMO

BACKGROUND: The integrated 6-year thoracic surgery (I-6) residency model was developed in part to promote early interest in cardiothoracic surgery in diverse trainees. To determine gaps in and opportunities for recruitment of women and minority groups in the pipeline for I-6 residency, we quantified rates of progression at each training level and trends over time. METHODS: We obtained 2015 to 2019 medical student, I-6 applicant, and I-6 resident gender and race/ethnicity demographic data from the American Association of Medical Colleges and Electronic Residency Application Service public databases and Accreditation Council for Graduate Medical Education Data Resource Books. We performed χ2, Fisher exact, and Cochran-Armitage tests for trend to compare 2015 and 2019. RESULTS: Our cross-sectional analysis found increased representation of women and all non-White races/ethnicities, except Native American, at each training level from 2015 to 2019 (P < .001 for all). The greatest trends in increases were seen in the proportions of women (28% vs 22%, P = .46) and Asian/Pacific Islander (25% vs 15%, P = .08) applicants. There was also an increase in the proportions of women (28% vs 24%, P = .024) and White (61% vs 58%, P = .007) I-6 residents, with a trend for Asian/Pacific Islanders (20% vs 17%, P = .08). The proportions of Hispanic (5%) and Black/African American (2%) I-6 residents in 2019 remained low. CONCLUSIONS: I-6 residency matriculation is not representative of medical student demographics and spotlights a need to foster early interest in cardiothoracic surgery among all groups underrepresented in medicine while ensuring that we mitigate bias in residency recruitment.


Assuntos
Internato e Residência , Especialidades Cirúrgicas , Humanos , Feminino , Estados Unidos , Estudos Transversais , Etnicidade , Especialidades Cirúrgicas/educação , Educação de Pós-Graduação em Medicina
10.
Nutrients ; 14(9)2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35565696

RESUMO

Healthy dietary intake and physical activity reduce the risk of non-communicable diseases. This systematic review and meta-analysis aimed to examine the effect of interventions including both nutrition and physical activity provided by nutrition and exercise practitioners for adults in the general population (those without diagnosed disease). The MEDLINE, CINAHL, Cochrane Central, Cochrane Database of Systematic Reviews and SportDiscus databases were searched for randomized controlled trials (RCTs) published from 2010 until April 2021. Outcomes included physical activity, fruit and vegetable intake, waist circumference, percent weight loss, quality of life (QoL) and adverse events. Grading of Recommendations Assessment, Development and Evaluation (GRADE) methods were used to synthesize and grade evidence. Meta-analyses were stratified according to participant health status. The database search identified 11,205 articles, and 31 RCTs were included. Interventions increased physical activity amount [standardized mean difference (SMD) (95% CI): 0.25 (0.08, 0.43)] (low certainty evidence); increased vegetable intake [SMD (95% CI): 0.14 (0.05, 0.23)] (moderate certainty evidence); reduced waist circumference [MD (95% CI): -2.16 cm (-2.96, -1.36)] (high certainty evidence); and increased likelihood of achieving 5% weight loss for adults with overweight and obesity [relative risk (95% CI): 2.37 (1.76, 3.19)] (high certainty evidence). Very low and low certainty evidence described little-to-no effect on QoL or adverse events. Nutrition and exercise practitioners play key roles in facilitating positive lifestyle behaviors to reduce cardiometabolic disease risk in adults.


Assuntos
Exercício Físico , Sobrepeso , Adulto , Humanos , Estilo de Vida , Sobrepeso/prevenção & controle , Qualidade de Vida , Redução de Peso
11.
Public Health Nutr ; 24(14): 4718-4736, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34030758

RESUMO

OBJECTIVE: The objective of this scoping review was to examine the research question: In the adults with or without cardiometabolic risk, what is the availability of literature examining interventions to improve or maintain nutrition and physical activity-related outcomes? Sub-topics included: (1) behaviour counseling or coaching from a dietitian/nutritionist or exercise practitioner, (2) mobile applications to improve nutrition and physical activity and (3) nutritional ergogenic aids. DESIGN: The current study is a scoping review. A literature search of the Medline Complete, CINAHL Complete, Cochrane Database of Systematic Reviews and other databases was conducted to identify articles published in the English language from January 2005 until May 2020. Data were synthesised using bubble charts and heat maps. SETTING: Out-patient, community and workplace. PARTICIPANTS: Adults with or without cardiometabolic risk factors living in economically developed countries. RESULTS: Searches resulted in 19 474 unique articles and 170 articles were included in this scoping review, including one guideline, thirty systematic reviews (SR), 134 randomised controlled trials and five non-randomised trials. Mobile applications (n 37) as well as ergogenic aids (n 87) have been addressed in several recent studies, including SR. While primary research has examined the effect of individual-level nutrition and physical activity counseling or coaching from a dietitian/nutritionist and/or exercise practitioner (n 48), interventions provided by these practitioners have not been recently synthesised in SR. CONCLUSION: SR of behaviour counseling or coaching provided by a dietitian/nutritionist and/or exercise practitioner are needed and can inform practice for practitioners working with individuals who are healthy or have cardiometabolic risk.


Assuntos
Doenças Cardiovasculares , Nutricionistas , Adulto , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Exercício Físico , Humanos , Estado Nutricional , Revisões Sistemáticas como Assunto
13.
J Thorac Cardiovasc Surg ; 160(6): 1479-1485.e5, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31706553

RESUMO

BACKGROUND: Del Nido cardioplegia (DC) offers prolonged single-dose myocardial protection in pediatric cardiac surgery. We set out to evaluate the efficacy of DC in adult patients undergoing isolated coronary artery bypass grafting (CABG). METHODS: From January 2012 to October 2017, 851 consecutive isolated CABG surgeries were performed by 2 study surgeons at our center with blood cardioplegia (BC, n = 350), used from January 2012 to April 2014, and DC (n = 501), used from May 2014 to October 2017. Propensity matching was used to yield 325 well-matched pairs. Clinical data were extracted from our local Society of Thoracic Surgeons database and mortality data from the Michigan State Social Security Death Index. RESULTS: Single-dose administration was used in 83% (417/501) of patients receiving DC. In propensity-matched groups, postoperative median troponin T levels (0.28 [0.16-0.59] ng/mL vs 0.46 [0.27-0.81] ng/mL; P < .01) were lower for patients receiving DC, and no difference in ejection fraction on postoperative echocardiography was observed (54 ± 12% and 53 ± 13% for BC and DC, respectively; P = .36). Perioperative outcomes were similar except for greater rate of atrial fibrillation (33% vs 23%; P = .01) in the DC group. Subgroup analyses revealed equivalent myocardial protection and clinical outcomes in patients with age ≥75 years, left ventricular ejection fraction ≤35%, left main disease, or Society of Thoracic Surgeons score ≥2.5%. Four-year survival did not differ between patients undergoing BC or DC. CONCLUSIONS: The current study revealed noninferior myocardial protection and clinical outcomes with DC versus BC in both routine and greater-risk patients undergoing isolated CABG. DC demonstrated the feasibility of single-dose administration for isolated CABG surgery. Larger randomized studies are needed to further explore the safety and efficacy of DC in adult cardiac surgery with longer crossclamp times.


Assuntos
Ponte de Artéria Coronária/métodos , Doença da Artéria Coronariana/cirurgia , Parada Cardíaca Induzida/métodos , Complicações Pós-Operatórias/prevenção & controle , Idoso , Soluções Cardioplégicas/administração & dosagem , Doença da Artéria Coronariana/diagnóstico , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Masculino , Complicações Pós-Operatórias/mortalidade , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Resultado do Tratamento , Estados Unidos/epidemiologia
14.
Rev. bras. anestesiol ; 68(4): 329-335, July-Aug. 2018. tab
Artigo em Inglês | LILACS | ID: biblio-958310

RESUMO

Abstract Background and objectives The primary aim was to determine risk factors for flumazenil administration during postanesthesia recovery. A secondary aim was to describe outcomes among patients who received flumazenil. Methods Patients admitted to the postanesthesia recovery room at a large, academic, tertiary care facility after surgery under general anesthesia from January 1, 2010, to April 30, 2015, were identified and matched to 2 controls each, by age, sex, and surgical procedure. Flumazenil was administered in the recovery phase immediately after general anesthesia, according to the clinical judgment of the anesthesiologist. Demographic, procedural, and outcome data were extracted from the electronic health record. Conditional logistic regression, accounting for the 1:2 matched-set case-control study designs, was used to assess characteristics associated with flumazenil use. Results The incidence of flumazenil administration in the postanesthesia care unit was 9.9 per 10,000 (95% CI, 8.4-11.6) general anesthetics. History of obstructive sleep apnea (Odds Ratio [OR] = 2.27; 95% CI 1.02-5.09), longer anesthesia (OR = 1.13; 95% CI 1.03-1.24 per 30 minutes), use of total intravenous anesthesia (OR = 6.09; 95% CI 2.60-14.25), and use of benzodiazepines (OR = 8.17; 95% CI 3.71-17.99) were associated with risk for flumazenil administration. Among patients who received midazolam, cases treated with flumazenil received a higher median (interquartile range) dose than controls: 3.5 mg (2.0-4.0 mg) vs. 2.0 mg (2.0-2.0 mg), respectively (p < 0.001). Flumazenil use was correlated with a higher rate of unanticipated noninvasive positive pressure ventilation, longer postanesthesia care unit stay, and increased rate of intensive care unit admissions. Conclusions Patients who required flumazenil postoperatively had received a higher dosage of benzodiazepines and utilized more postoperative health care resources. More conservative perioperative use of benzodiazepines may improve postoperative recovery and use of health care resources.


Resumo Justificativa e objetivos Determinar os fatores de risco da administração de flumazenil durante a recuperação pós-anestésica e descrever os desfechos entre os pacientes que receberam flumazenil. Métodos Os pacientes admitidos em sala de recuperação pós-anestésica de um grande centro universitário em setor terciário de cuidados pós-cirurgia sob anestesia geral entre 1° de janeiro de 2010 e 30 de abril de 2015 foram identificados e pareados com dois controles cada por idade, sexo e procedimento cirúrgico. Flumazenil foi administrado na fase de recuperação imediatamente após a anestesia geral, de acordo com a avaliação clínica do anestesiologista. Os dados demográficos, dos procedimentos e dos desfechos foram extraídos do registro eletrônico de saúde. A regressão logística condicional para os desenhos do estudo de caso-controle pareado em 1:2 foi usada para avaliar as características associadas ao uso de flumazenil. Resultados A incidência da administração de flumazenil em sala de recuperação pós-anestésica foi de 9,9 por 10.000 (95% IC: 8,4-1,6) anestesias gerais. História da apneia obstrutiva do sono (razão de chances [OR] = 2,27; IC 95%: 1,02-5,09), anestesia de longa duração (OR = 1,13; IC 95%: 1,03-1,24 por 30 minutos), uso de anestesia intravenosa total (OR = 6,09; IC de 95%: 2,60-14,25) e uso de benzodiazepínicos (OR = 8,17; IC 95%: 3,71-17,99) foram associados a risco para a administração de flumazenil. Entre os pacientes que receberam midazolam, os casos tratados com flumazenil receberam uma dose mediana mais alta (intervalo interquartil) do que os controles: 3,5 mg (2,0-4,0 mg) vs. 2,0 mg (2,0-2,0 mg), respectivamente (p < 0,001). O uso de flumazenil foi correlacionado com uma taxa maior não prevista de ventilação não invasiva com pressão positiva, permanência mais longa em sala de recuperação pós-anestésica e aumento da taxa de admissões em unidade de terapia intensiva. Conclusão Os pacientes que precisaram de flumazenil no pós-operatório receberam uma dose maior de benzodiazepínicos e usaram mais recursos de cuidados da saúde no pós-operatório. O uso mais conservador de benzodiazepínicos no período perioperatório pode melhorar a recuperação e o uso de recursos de cuidados da saúde no pós-operatório.


Assuntos
Humanos , Complicações Pós-Operatórias , Período de Recuperação da Anestesia , Flumazenil/administração & dosagem , Receptores de GABA-A/administração & dosagem , Estudos de Casos e Controles , Estudos Retrospectivos
15.
Braz J Anesthesiol ; 68(4): 329-335, 2018.
Artigo em Português | MEDLINE | ID: mdl-29631877

RESUMO

BACKGROUND AND OBJECTIVES: The primary aim was to determine risk factors for flumazenil administration during postanesthesia recovery. A secondary aim was to describe outcomes among patients who received flumazenil. METHODS: Patients admitted to the postanesthesia recovery room at a large, academic, tertiary care facility after surgery under general anesthesia from January 1, 2010, to April 30, 2015, were identified and matched to 2 controls each, by age, sex, and surgical procedure. Flumazenil was administered in the recovery phase immediately after general anesthesia, according to the clinical judgment of the anesthesiologist. Demographic, procedural, and outcome data were extracted from the electronic health record. Conditional logistic regression, accounting for the 1:2 matched-set case-control study designs, was used to assess characteristics associated with flumazenil use. RESULTS: The incidence of flumazenil administration in the postanesthesia care unit was 9.9 per 10,000 (95% CI, 8.4-11.6) general anesthetics. History of obstructive sleep apnea (Odds Ratio [OR]=2.27; 95% CI 1.02-5.09), longer anesthesia (OR=1.13; 95% CI 1.03-1.24 per 30minutes), use of total intravenous anesthesia (OR=6.09; 95% CI 2.60-14.25), and use of benzodiazepines (OR=8.17; 95% CI 3.71-17.99) were associated with risk for flumazenil administration. Among patients who received midazolam, cases treated with flumazenil received a higher median (interquartile range) dose than controls: 3.5mg (2.0-4.0mg) vs. 2.0mg (2.0-2.0mg), respectively (p<0.001). Flumazenil use was correlated with a higher rate of unanticipated noninvasive positive pressure ventilation, longer postanesthesia care unit stay, and increased rate of intensive care unit admissions. CONCLUSIONS: Patients who required flumazenil postoperatively had received a higher dosage of benzodiazepines and utilized more postoperative health care resources. More conservative perioperative use of benzodiazepines may improve postoperative recovery and use of health care resources.

16.
Artigo em Inglês | MEDLINE | ID: mdl-19963865

RESUMO

The Wireless Instantaneous Neurotransmitter Concentration Sensing System (WINCS) measures extracellular neurotransmitter concentration in vivo and displays the data graphically in nearly real time. WINCS implements two electroanalytical methods, fast-scan cyclic voltammetry (FSCV) and fixed-potential amperometry (FPA), to measure neurotransmitter concentrations at an electrochemical sensor, typically a carbon-fiber microelectrode. WINCS comprises a battery-powered patient module and a custom software application (WINCSware) running on a nearby personal computer. The patient module impresses upon the electrochemical sensor either a constant potential (for FPA) or a time-varying waveform (for FSCV). A transimpedance amplifier converts the resulting current to a signal that is digitized and transmitted to the base station via a Bluetooth radio link. WINCSware controls the operational parameters for FPA or FSCV, and records the transmitted data stream. Filtered data is displayed in various formats, including a background-subtracted plot of sequential FSCV scans - a representation that enables users to distinguish the signatures of various analytes with considerable specificity. Dopamine, glutamate, adenosine and serotonin were selected as analytes for test trials. Proof-of-principle tests included in vitro flow-injection measurements and in vivo measurements in rat and pig. Further testing demonstrated basic functionality in a 3-Tesla MRI unit. WINCS was designed in compliance with consensus standards for medical electrical device safety, and it is anticipated that its capability for real-time intraoperative monitoring of neurotransmitter release at an implanted sensor will prove useful for advancing functional neurosurgery.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Monitorização Intraoperatória/instrumentação , Monitorização Intraoperatória/métodos , Encéfalo/metabolismo , Dopamina/metabolismo , Humanos , Serotonina/metabolismo , Software
18.
J Am Soc Hortic Sci ; 129(3): 331-8, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15776542

RESUMO

The productivity of lettuce in a combination of high light, high temperature, and elevated CO2 has not been commonly studied because rapid growth usually causes a calcium deficiency in meristems called tipburn, which greatly reduces quality and marketability. We eliminated tipburn by blowing air directly onto the meristem, which allowed us to increase the photosynthetic photon flux (PPF) to 1000 micromoles m-2 s-1 (57.6 mol m-2 d-1); two to three times higher than normally used for lettuce. Eliminating tipburn doubled edible yield at the highest PPF level. In addition to high PPF, CO2 was elevated to 1200 micromoles m-2 mol-1, which increased the temperature optimum from 25 to 30 degrees C. The higher temperature increased leaf expansion rate, which improved radiation capture and more than doubled yield. Photosynthetic efficiency, measured as canopy quantum yield in a whole-plant gas exchange system, steadily increased up to the highest temperature of 32 degrees C in high CO2. The highest productivity was 19 g m-2 d-1 of dry biomass (380 g d-1 fresh mass) averaged over the 23 days the plants received light. Without the limitation of tipburn, the combination of high PPF, high temperature, and elevated CO2 resulted in a 4-fold increase in growth rate over productivity in conventional environments.


Assuntos
Ambiente Controlado , Lactuca/crescimento & desenvolvimento , Lactuca/metabolismo , Doenças das Plantas , Folhas de Planta/crescimento & desenvolvimento , Biomassa , Cálcio/metabolismo , Dióxido de Carbono/metabolismo , Clorofila/metabolismo , Luz , Meristema/crescimento & desenvolvimento , Meristema/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Potássio/metabolismo , Compostos de Amônio Quaternário/metabolismo , Temperatura , Vento
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