Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
PLoS One ; 16(7): e0254635, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264974

RESUMO

BACKGROUND: Statins have anti-inflammatory and immunomodulatory effects that may reduce the severity of coronavirus disease 2019 (COVID-19), in which organ dysfunction is mediated by severe inflammation. Large studies with diverse populations evaluating statin use and outcomes in COVID-19 are lacking. METHODS AND RESULTS: We used data from 10,541 patients hospitalized with COVID-19 through September 2020 at 104 US hospitals enrolled in the American Heart Association's COVID-19 Cardiovascular Disease (CVD) Registry to evaluate the associations between statin use and outcomes. Prior to admission, 42% of subjects (n = 4,449) used statins (7% on statins alone, 35% on statins plus anti-hypertensives). Death (or discharge to hospice) occurred in 2,212 subjects (21%). Outpatient use of statins, either alone or with anti-hypertensives, was associated with a reduced risk of death (adjusted odds ratio [aOR] 0.59, 95% CI 0.50-0.69), adjusting for demographic characteristics, insurance status, hospital site, and concurrent medications by logistic regression. In propensity-matched analyses, use of statins and/or anti-hypertensives was associated with a reduced risk of death among those with a history of CVD and/or hypertension (aOR 0.68, 95% CI 0.58-0.81). An observed 16% reduction in odds of death among those without CVD and/or hypertension was not statistically significant. CONCLUSIONS: Patients taking statins prior to hospitalization for COVID-19 had substantially lower odds of death, primarily among individuals with a history of CVD and/or hypertension. These observations support the continuation and aggressive initiation of statin and anti-hypertensive therapies among patients at risk for COVID-19, if these treatments are indicated based upon underlying medical conditions.


Assuntos
Anti-Hipertensivos/administração & dosagem , COVID-19/epidemiologia , Doenças Cardiovasculares/epidemiologia , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Sistema de Registros/estatística & dados numéricos , Adulto , Fatores Etários , Idoso , American Heart Association , Anti-Hipertensivos/uso terapêutico , COVID-19/mortalidade , Doenças Cardiovasculares/tratamento farmacológico , Uso de Medicamentos/estatística & dados numéricos , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Grupos Populacionais/estatística & dados numéricos , Estados Unidos
2.
Int J Cardiol Heart Vasc ; : 100770, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33778152

RESUMO

Background: Coronavirus Disease-2019 (COVID-19) is associated with cardiovascular injury, but left ventricular (LV) function is largely preserved. We aimed to evaluate for subclinical LV dysfunction in patients with COVID-19 through myocardial strain analysis. Methods: We performed a single-center retrospective cohort study of all patients hospitalized with COVID-19 who underwent echocardiography. Traditional echocardiographic and global longitudinal strain (GLS) values were compared with prior and subsequent echocardiograms. Results: Among 96 patients hospitalized with COVID-19 with complete echocardiograms, 67 (70%) had adequate image quality for strain analysis. The cohort was predominantly male (63%) and 18% had prevalent cardiovascular disease (CVD). Echocardiograms were largely normal with median [IQR] LV ejection fraction (EF) 62% [56%, 68%]. However, median GLS was abnormal in 91% (-13.5% [-15.0%, -10.8%]). When stratified by CVD, both groups had abnormal GLS, but presence of CVD was associated with worse median GLS (-11.6% [-13.4%, -7.2%] vs -13.9% [-15.0%, -11.3%], p=0.03). There was no difference in EF or GLS when stratified by symptoms or need for intensive care. Compared to pre-COVID-19 echocardiograms, EF was unchanged, but median GLS was significantly worse (-15% [-16%, -14%] vs -12% [-14%, -10%], p=0.003). Serial echocardiograms showed no significant changes in GLS or EF overall, however patients who died had stable or worsening GLS, while those who survived to discharge home showed improved GLS. Conclusions: Patients with COVID-19 had evidence of subclinical cardiac dysfunction manifested by reduced GLS despite preserved EF. These findings were observed regardless of history of CVD, presence of COVID-19 symptoms, or severity of illness. Funding Sources: Partially supported by the National Institutes of Health, Grant 5T32HL079891, as part of the UCSD Integrated Cardiovascular Epidemiology Fellowship. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. Disclosures: There are no relationships with industry relevant to this manuscript. The authors report no relationships that could be construed as a conflict of interest.

3.
Int J Cardiol ; 324: 122-130, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32950592

RESUMO

BACKGROUND: Geographic variations in management and outcomes of individuals supported by continuous-flow left ventricular assist devices (CF-LVAD) between the United States (US) and Europe (EU) is largely unknown. METHODS: We created a retrospective, multinational registry of 524 patients who received a CF-LVAD (either HVAD or Heartmate II) between January 2008 and April 2017. Follow up spanned from date of CF-LVAD implant to post-HTx period with a median follow up of 44.8 months. RESULTS: The cohort included 299 (57.1%) EU and 225 (42.9%) US patients. Although the US cohort was significantly older with a higher prevalence of comorbidities, survival was similar between the cohorts (US 63.1%, EU 68.4% at 5 years, unadjusted log-rank test p = 0.43).Multivariate analyses suggested that older age, higher body mass index, elevated creatinine, use of temporary mechanical circulatory support prior CF-LVAD, and implantation of HVAD were associated with increased mortality. Among CF-LVAD patients undergoing HTx, the median time on CF-LVAD support was shorter in the US, meanwhile US donors were younger. Finally, the pattern of adverse events (stroke, gastrointestinal bleedings, late right ventricular failure, and driveline infection) during support differed significantly between US and EU. CONCLUSIONS: Although waitlisted patients in the US on CF-LVAD have higher risk comorbid conditions, the overall outcome is similar in US and EU. Geographic variations with regards to donor characteristics, duration of CF-LVAD support prior to transplant, and adverse events on support can explain the disparity in the utilization of mechanical bridge to transplant strategy between US and EU.


Assuntos
Insuficiência Cardíaca , Transplante de Coração , Coração Auxiliar , Idoso , Europa (Continente)/epidemiologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/cirurgia , Coração Auxiliar/efeitos adversos , Humanos , Sistema de Registros , Estudos Retrospectivos , Resultado do Tratamento , Estados Unidos/epidemiologia
4.
Am J Cardiol ; 136: 149-155, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32946859

RESUMO

The impact of statins, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) on coronavirus disease 2019 (COVID-19) severity and recovery is important given their high prevalence of use among individuals at risk for severe COVID-19. We studied the association between use of statin/angiotensin-converting enzyme inhibitors/ARB in the month before hospital admission, with risk of severe outcome, and with time to severe outcome or disease recovery, among patients hospitalized for COVID-19. We performed a retrospective single-center study of all patients hospitalized at University of California San Diego Health between February 10, 2020 and June 17, 2020 (n = 170 hospitalized for COVID-19, n = 5,281 COVID-negative controls). Logistic regression and competing risks analyses were used to investigate progression to severe disease (death or intensive care unit admission), and time to discharge without severe disease. Severe disease occurred in 53% of COVID-positive inpatients. Median time from hospitalization to severe disease was 2 days; median time to recovery was 7 days. Statin use prior to admission was associated with reduced risk of severe COVID-19 (adjusted OR 0.29, 95%CI 0.11 to 0.71, p < 0.01) and faster time to recovery among those without severe disease (adjusted HR for recovery 2.69, 95%CI 1.36 to 5.33, p < 0.01). The association between statin use and severe disease was smaller in the COVID-negative cohort (p for interaction = 0.07). There was potential evidence of faster time to recovery with ARB use (adjusted HR 1.92, 95%CI 0.81 to 4.56). In conclusion, statin use during the 30 days prior to admission for COVID-19 was associated with a lower risk of developing severe COVID-19, and a faster time to recovery among patients without severe disease.


Assuntos
Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Betacoronavirus , Infecções por Coronavirus/epidemiologia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Pneumonia Viral/epidemiologia , Adulto , Idoso , COVID-19 , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/terapia , Cuidados Críticos , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/terapia , Recuperação de Função Fisiológica , Estudos Retrospectivos , Fatores de Risco , SARS-CoV-2 , Índice de Gravidade de Doença
6.
Circ Heart Fail ; 12(7): e006058, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31213069

RESUMO

Advanced heart failure therapies, including heart transplantation and durable mechanical circulatory support, are available to a limited number of patients because of the scarcity of donors, expense, and large burden of care. The importance of psychological and social determinants of health, including cognitive status, health literacy, psychopathology, social support, medical adherence, and substance abuse, are emphasized in advanced heart failure and further amplified in the context of mechanical circulatory support and heart transplantation. The psychosocial assessment of advanced heart failure therapy candidates remains largely subjective, requiring a multidisciplinary evaluation, which may include psychiatrists, social workers, case managers, financial coordinators, pharmacists, and clinicians. Objective tools-including the Stanford Integrated Psychosocial Assessment for Transplantation, Psychosocial Assessment of Candidates for Transplantation, and Transplant Evaluation Rating Scale-were developed and validated in limited populations to help standardize the evaluation process. Small, retrospective studies have inconsistently shown that these tools may predict clinical outcomes in the transplant population, with higher-risk scores associated with readmissions, rejection episodes, and infections. However, it has been more difficult to show that these tools can predict mortality, and their applicability to the mechanical circulatory support population is less studied. The International Society for Heart and Lung Transplantation released a consensus statement in 2018 to promote consistency of psychosocial evaluation across advanced heart failure programs, but it lacks specific recommendations given the current state of evidence. This state-of-the-art review expands on the current consensus by critically reviewing current studies supporting available objective assessment tools, proposing a psychosocial evaluation framework that uses a multidisciplinary approach and offering future directions for research.


Assuntos
Insuficiência Cardíaca/terapia , Transplante de Coração , Ventrículos do Coração/cirurgia , Coração Auxiliar , Consenso , Insuficiência Cardíaca/diagnóstico , Transplante de Coração/métodos , Coração Auxiliar/efeitos adversos , Humanos , Seleção de Pacientes
7.
J Am Coll Cardiol ; 73(18): 2296-2298, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31072573
8.
Circulation ; 139(8): 1094-1101, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30779650

RESUMO

Cardiovascular disease continues to be the leading cause of death among women in the United States. One of the barriers to improving cardiovascular disease outcomes in women is the lack of reliable, effective screening modalities. Breast arterial calcification has emerged as a potential risk stratification tool. Localized deposition in the media of the artery, known as Mönckeberg medial calcific sclerosis, is notably different from the intimal atherosclerotic process commonly associated with coronary artery disease. Nonetheless, studies favor a correlation between breast arterial calcification and cardiovascular risk factors or coronary artery disease, defined as coronary artery calcification on computed tomography scan or both nonobstructive and obstructive lesions on angiography. Since a majority of women over the age of 40 undergo yearly breast cancer screening with mammography, measurement of breast arterial calcification may offer a personalized, noninvasive approach to risk-stratify women for cardiovascular disease at no additional cost or radiation. Mammography has the potential to alter the course of the leading cause of death in women, heart disease, through the evaluation of breast arterial calcification and identification of opportunities for prevention. Current evidence supports the universal reporting of breast arterial calcifications and personalized patient-provider discussions to more aggressively treat cardiac risk factors through targeted medical therapies or healthy lifestyle changes.


Assuntos
Mama/irrigação sanguínea , Doenças Cardiovasculares/epidemiologia , Esclerose Calcificante da Média de Monckeberg/epidemiologia , Adulto , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/terapia , Feminino , Humanos , Incidência , Achados Incidentais , Masculino , Mamografia , Esclerose Calcificante da Média de Monckeberg/diagnóstico por imagem , Esclerose Calcificante da Média de Monckeberg/mortalidade , Esclerose Calcificante da Média de Monckeberg/terapia , Valor Preditivo dos Testes , Prevalência , Prognóstico , Medição de Risco , Fatores de Risco , Fatores Sexuais
9.
J Cardiovasc Surg (Torino) ; 60(2): 251-258, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30168306

RESUMO

BACKGROUND: The optimal advanced heart failure (HF) therapy strategy for patients aged 60 or older with end-stage HF refractory to optimal medical therapy remains uncertain. This study compares outcomes of three advanced HF therapy strategies in this patient population. METHODS: A single-center retrospective study was conducted in 95 patients aged 60-73 years who had undergone isolated heart transplantation (HTx) or continuous flow left ventricular assist device (LVAD) implantation from 2010 to 2017. Patients were stratified into three cohorts by strategy; HTx-only (N.=25), LVAD-to-HTx (N.=29), and LVAD-only (N.=41). Primary end point was 2-year overall survival. Secondary end points included incidence of post-operative adverse events, freedom from first readmission at 1 year, and percentage of days spent in hospital following advanced HF therapy. RESULTS: Two-year survival was 91% in HTx-only patients, 88% in LVAD-to-HTx patients, and 49% in LVAD-only patients (P=0.0008). No significant difference in post-transplant survival was found between patients with or without LVAD-related adverse events preceding transplantation (P=0.42). One-year freedom from first readmission was 38.3% in HTx-only patients, 17.2% in LVAD-to-HTx patients and 7.3% in LVAD-only patients (P=0.0028). Patients in LVAD-to-HTx cohort had higher incidences of gastrointestinal bleeding (38% vs. 3%; P<0.01), major bleeding (28% vs. 3%; P=0.02), and right heart failure (69% vs. 31%; P<0.01) during post-LVAD period compared with post-HTx period. Their percentage of days spent in hospital during post-LVAD period was significantly higher than post-HTx period (7.9% vs. 1.2%; P<0.001). CONCLUSIONS: Our experience with patients over 60 years old undergoing advanced therapy suggests that HTx-only and LVAD-to-HTx strategies had superior medium-term survival than LVAD-only strategy. LVAD-to-HTx strategy is effective in reducing incidence of adverse events and percentage of hospitalized days in this specific patient population.


Assuntos
Insuficiência Cardíaca/terapia , Transplante de Coração , Coração Auxiliar , Função Ventricular Esquerda , Fatores Etários , Idoso , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Transplante de Coração/efeitos adversos , Transplante de Coração/mortalidade , Coração Auxiliar/efeitos adversos , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Readmissão do Paciente , Complicações Pós-Operatórias/etiologia , Desenho de Prótese , Recuperação de Função Fisiológica , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
10.
Heart Lung ; 48(2): 85-89, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30227993

RESUMO

BACKGROUND: The Stanford integrated psychosocial assessment for transplantation (SIPAT) is a validated psychosocial evaluation tool in the transplant population. OBJECTIVE: We evaluated SIPAT in predicting post-left ventricular assist device (LVAD) outcomes, including cumulative re-admissions, driveline infections, pump malfunction, pump thrombosis, gastrointestinal bleeding, major bleeding, stroke and right ventricular failure. METHODS: This retrospective study included 50 LVAD patients at an academic institution in the United States who had a pre-implant SIPAT score during the years 2015-2017. Patients were split into two groups based on SIPAT score, separating a "excellent"/"good" from a "minimally acceptable"/"poor" candidate. Poisson regression, using SIPAT as both a categorical and continuous variable, was used to compare the incidence rates of the primary outcome of cumulative re-admissions and secondary outcomes of LVAD complications. RESULTS: The patient cohort was predominantly male 93.5% vs 89.4% (p = 0.629) with a median age of 67.0 vs 58.0 years (p = 0.037), planned destination therapy 48.4% vs 68.4% (p = 0.242) and median LVAD follow-up time of 241 vs 379 days (p = 0.10) in the low- and high- SIPAT groups, respectively. SIPAT was not a significant predictor for cumulative re-admissions, but there was an association between higher SIPAT scores and major bleeding. CONCLUSION: In this single-center retrospective study, SIPAT did not predict cumulative re-admissions. Further study is required to validate SIPAT before clinical implementation.


Assuntos
Insuficiência Cardíaca/cirurgia , Transplante de Coração/psicologia , Coração Auxiliar , Idoso , Feminino , Insuficiência Cardíaca/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Readmissão do Paciente/tendências , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos
11.
Am J Respir Cell Mol Biol ; 60(6): 637-649, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30562042

RESUMO

Pulmonary arterial hypertension (PAH) is characterized by increased pulmonary artery pressure and vascular resistance, typically leading to right heart failure and death. Current therapies improve quality of life of the patients but have a modest effect on long-term survival. A detailed transcriptomics and systems biology view of the PAH lung is expected to provide new testable hypotheses for exploring novel treatments. We completed transcriptomics analysis of PAH and control lung tissue to develop disease-specific and clinical data/tissue pathology gene expression classifiers from expression datasets. Gene expression data were integrated into pathway analyses. Gene expression microarray data were collected from 58 PAH and 25 control lung tissues. The strength of the dataset and its derived disease classifier was validated using multiple approaches. Pathways and upstream regulators analyses was completed with standard and novel graphical approaches. The PAH lung dataset identified expression patterns specific to PAH subtypes, clinical parameters, and lung pathology variables. Pathway analyses indicate the important global role of TNF and transforming growth factor signaling pathways. In addition, novel upstream regulators and insight into the cellular and innate immune responses driving PAH were identified. Finally, WNT-signaling pathways may be a major determinant underlying the observed sex differences in PAH. This study provides a transcriptional framework for the PAH-diseased lung, supported by previously reported findings, and will be a valuable resource to the PAH research community. Our investigation revealed novel potential targets and pathways amenable to further study in a variety of experimental systems.


Assuntos
Pulmão/metabolismo , Pulmão/patologia , Hipertensão Arterial Pulmonar/genética , Análise de Sistemas , Transcriptoma/genética , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Regulação da Expressão Gênica , Ontologia Genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Hipertensão Arterial Pulmonar/patologia , Caracteres Sexuais , Transdução de Sinais/genética , Adulto Jovem
13.
Dig Dis Sci ; 62(2): 299-304, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27990589

RESUMO

Lynch syndrome is an autosomal-dominant hereditary cancer syndrome. Mutations in mismatch repair genes, including MLH1, MSH2, MSH6, and PMS2, are implicated in the pathogenesis of the syndrome through microsatellite instability (MSI) and a rapid adenoma-carcinoma sequence. The primary methodologies for diagnosis include clinical criteria (Amsterdam I/II, Revised Bethesda Guidelines), computational models, and genetic testing (MSI, immunohistochemistry, germline testing). Universal genetic testing of colorectal cancers has gained popularity as a method to identify high-risk individuals and to offer appropriate cancer surveillance, psychological reassurance, and family planning. Management includes short-interval surveillance with colonoscopy in those without colorectal cancer and colectomy for those with cancer. Long-term chemoprevention with aspirin may improve mortality.


Assuntos
Adenoma/diagnóstico , Carcinoma/diagnóstico , Colectomia , Colonoscopia , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Adenoma/genética , Adenoma/prevenção & controle , Adenoma/cirurgia , Anti-Inflamatórios não Esteroides/uso terapêutico , Aspirina/uso terapêutico , Carcinoma/genética , Carcinoma/prevenção & controle , Carcinoma/cirurgia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais Hereditárias sem Polipose/prevenção & controle , Neoplasias Colorretais Hereditárias sem Polipose/cirurgia , Reparo de Erro de Pareamento de DNA/genética , Proteínas de Ligação a DNA/genética , Gerenciamento Clínico , Detecção Precoce de Câncer , Gastroenterologistas , Testes Genéticos , Humanos , Imuno-Histoquímica , Instabilidade de Microssatélites , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Fatores de Tempo
15.
Resuscitation ; 102: 75-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26944043

RESUMO

OBJECTIVE: Bystander cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) has the ability to improve patient survival. However, the rates at which CPR occurs are suboptimal. We hypothesized that targeted CPR training in neighborhoods with low bystander CPR and high incidence of cardiac arrests would increase the incidence of bystander CPR for adult OHCA. METHODS: This study is a descriptive observation and analysis of the TAKE 10 program, which recruited City of Austin and Travis County residents to teach fellow community members compression-only CPR. Twelve zip codes in Austin and Travis County were identified as "high-risk," based on low bystander CPR rates and high incidences of cardiac arrest. Data was collected on bystander CPR for OHCA over the study period of July 2008 to September 2013. Incidence of cardiac arrest and bystander CPR were calculated yearly and overall. RESULTS: Over the study period, a total of 11,242 community members completed compression-only CPR training. While there was no significant difference in the number of individuals trained in high-risk zip codes compared to the other zip codes (High-Risk [n±sd] 263±235; General 212±193; p-value 0.46), the amount of people trained in the high-risk zip codes did trend upwards over the study period. Additionally, there was an increase in percent of bystander CPR per eligible cardiac arrest in the high-risk zip codes (2009: [n±sd] 0.28±0.34 to 2013: 0.39±0.28). CONCLUSIONS: Targeted compression-only CPR training in high-risk neighborhoods may be associated with increased bystander CPR rates over time.


Assuntos
Reanimação Cardiopulmonar/educação , Serviços Médicos de Emergência , Educação em Saúde/métodos , Parada Cardíaca Extra-Hospitalar/terapia , Melhoria de Qualidade , Sistema de Registros , Humanos , Características de Residência , Estudos Retrospectivos , Estados Unidos
16.
West J Emerg Med ; 16(3): 414-7, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25987916

RESUMO

We use a case report to describe the acute psychiatric and medical management of marijuana intoxication in the emergency setting. A 34-year-old woman presented with erratic, disruptive behavior and psychotic symptoms after recreational ingestion of edible cannabis. She was also found to have mild hypokalemia and QT interval prolongation. Psychiatric management of cannabis psychosis involves symptomatic treatment and maintenance of safety during detoxification. Acute medical complications of marijuana use are primarily cardiovascular and respiratory in nature; electrolyte and electrocardiogram monitoring is indicated. This patient's psychosis, hypokalemia and prolonged QTc interval resolved over two days with supportive treatment and minimal intervention in the emergency department. Patients with cannabis psychosis are at risk for further psychotic sequelae. Emergency providers may reduce this risk through appropriate diagnosis, acute treatment, and referral for outpatient care.


Assuntos
Cannabis/efeitos adversos , Hipopotassemia/diagnóstico , Síndrome do QT Longo/diagnóstico , Psicoses Induzidas por Substâncias/diagnóstico , Adulto , Cacau , Eletrocardiografia , Eletrólitos , Serviço Hospitalar de Emergência , Feminino , Humanos , Hipopotassemia/induzido quimicamente , Hipopotassemia/terapia , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/terapia , Psicoses Induzidas por Substâncias/psicologia , Psicoses Induzidas por Substâncias/terapia , Transtornos Psicóticos/psicologia , Encaminhamento e Consulta
17.
J Am Chem Soc ; 135(30): 11257-65, 2013 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-23837635

RESUMO

An intramolecular reaction catalyzed by Rh porphyrins was studied in the presence of interfacial electric fields. 1-Diazo-3,3-dimethyl-5-phenylhex-5-en-2-one (2) reacts with Rh porphyrins via a putative carbenoid intermediate to form cyclopropanation product 3,3-dimethyl-5-phenylbicyclo[3.1.0]hexan-2-one (3) and insertion product 3,3-dimethyl-2,3-dihydro-[1,1'-biphenyl]-4(1H)-one (4). To study this reaction in the presence of an interfacial electric field, Si electrodes coated with thin films of insulating dielectric layers were used as the opposing walls of a reaction vessel, and Rh porphyrin catalysts were localized to the dielectric-electrolyte interface. The charge density was varied at the interface by changing the voltage across the two electrodes. The product ratio was analyzed as a function of the applied voltage and the surface chemistry of the dielectric layer. In the absence of an applied voltage, the ratio of 3:4 was approximately 10:1. With a TiO2 surface, application of a voltage induced a Rh porphyrin-TiO2 interaction that resulted in an increase in the 3:4 ratio to a maximum in which 4 was nearly completely suppressed (>100:1). With an Al2O3 surface or an alkylphosphonate-coated surface, the voltage caused a decrease in the 3:4 ratio, with a maximum effect of lowering the ratio to 1:2. The voltage-induced decrease in the 3:4 ratio in the absence of TiO2 was consistent with a field-dipole effect that changed the difference in activation energies for the product-determining step to favor product 4. Effects were observed for porphyrin catalysts localized to the electrode-electrolyte interface either through covalent attachment or surface adsorption, enabling the selectivity to be controlled with unfunctionalized Rh porphyrins. The magnitude of the selectivity change was limited by the maximum interfacial charge density that could be attained before dielectric breakdown.

18.
PLoS One ; 8(2): e52669, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23468837

RESUMO

Forecasting technological progress is of great interest to engineers, policy makers, and private investors. Several models have been proposed for predicting technological improvement, but how well do these models perform? An early hypothesis made by Theodore Wright in 1936 is that cost decreases as a power law of cumulative production. An alternative hypothesis is Moore's law, which can be generalized to say that technologies improve exponentially with time. Other alternatives were proposed by Goddard, Sinclair et al., and Nordhaus. These hypotheses have not previously been rigorously tested. Using a new database on the cost and production of 62 different technologies, which is the most expansive of its kind, we test the ability of six different postulated laws to predict future costs. Our approach involves hindcasting and developing a statistical model to rank the performance of the postulated laws. Wright's law produces the best forecasts, but Moore's law is not far behind. We discover a previously unobserved regularity that production tends to increase exponentially. A combination of an exponential decrease in cost and an exponential increase in production would make Moore's law and Wright's law indistinguishable, as originally pointed out by Sahal. We show for the first time that these regularities are observed in data to such a degree that the performance of these two laws is nearly the same. Our results show that technological progress is forecastable, with the square root of the logarithmic error growing linearly with the forecasting horizon at a typical rate of 2.5% per year. These results have implications for theories of technological change, and assessments of candidate technologies and policies for climate change mitigation.


Assuntos
Modelos Estatísticos , Tecnologia/tendências , Algoritmos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...