Positioning of grid points for spanning potential energy surfaces-How much effort is really needed?

The positions of grid points for representing a multidimensional potential energy surface (PES) have a non-negligible impact on its accuracy and the associated computational effort for its generation. Six different positioning schemes were studied for PESs represented by n-mode expansions as needed for the accurate calculation of anharmonic vibrational frequencies by means of vibrational configuration interaction theory. A static approach, which has successfully been used in many applications, and five adaptive schemes based on Gaussian process regression have been investigated with respect to the number of necessary grid points and the accuracy of the fundamental modes for a small set of test molecules. A comparison with a related, more sophisticated, and consistent approach by Christiansen et al. is provided. The impact of the positions of the ab initio grid points is discussed for multilevel PESs, for which the computational effort of the individual electronic structure calculations decreases for increasing orders of the n-mode expansion. As a result of that, the ultimate goal is not the maximal reduction of grid points but rather the computational cost, which is not directly related.

Evaporation and Fragmentation of Organic Molecules in Strong Electric Fields Simulated with DFT.

Atom probe tomography allows us to measure the three-dimensional composition of materials with up to atomic resolution by evaporating the material using high electric fields. Initially developed for metals, it is increasingly used for covalently bound structures. To aid the interpretation of the obtained fragmentation pattern, we modeled the fragmentation and desorption of self-assembled monolayers of thiolate molecules on a gold surface in strong electrostatic fields using density functional theory. We used a cluster model and a periodic model of amino-undecanethiolate, NH2(CH2)11S, and fluoro-decanethiolate, CF3(CF2)7(CH2)2S. In the former molecule, the fragment CH2NH2+ was found to evaporate at fields of 5.4-7.7 V/nm. It was followed by different hydrocarbon fragments. Fluoro-decanethiolate evaporates CF3+ at fields of 5.7-6.7 V/nm in the cluster model and at 15.4-23.1 V/nm in the periodic model, followed by CF2+ and C2F42+. Detailed analysis of the electronic structure during the evaporation process revealed a stepwise accumulation of the charge in the head groups exposed to the strongest fields, followed by dissociation of covalent bonds. These observations will facilitate the analysis of atom probe experiments of covalently bound structures.

Geometry Optimization in Internal Coordinates Based on Gaussian Process Regression: Comparison of Two Approaches.

Geometry optimization based on Gaussian process regression (GPR) was extended to internal coordinates. We used delocalized internal coordinates composed of distances and several types of angles and compared two methods of including them. In both cases, the GPR surrogate surface is trained on geometries in internal coordinates. In one case, it predicts the gradient in Cartesian coordinates and in the other, in internal coordinates. We tested both methods on a set of 30 small molecules and one larger Rh complex taken from the study of a catalytic mechanism. The former method is slightly more efficient, while the latter method is somewhat more robust. Both methods reduce the number of required optimization steps compared to GPR in Cartesian coordinates or the standard L-BFGS optimizer. We found it advantageous to use automatically adjusted hyperparameters to optimize them.

Pregnancy-associated spontaneous coronary artery dissection: insights from a case series of 13 patients.

AIMS: We sought to present a series of 13 pregnancy-associated spontaneous coronary artery dissection (P-SCAD), their angiographic and multimodal imaging findings, acute phase treatment, and outcomes. METHODS AND RESULTS: Between 2005 and 2015, 13 cases of P-SCAD were collected from a database of 11 tertiary hospitals. The mean age was 33.8 ± 3.7 years; most patients had no risk factors for coronary artery disease, and the majority were multiparous. P-SCAD occurred during the puerperium in 12 patients with a median time of 10 days. Only one patient presented with P-SCAD in the 37th week of pregnancy, and she was the only patient who died in this series. Six patients (46%) presented with ST-segment elevation acute myocardial infarction (STEMI), six (46%) presented with non-STEMI, and one presented with unstable angina; one-third of women had cardiogenic shock. In 12 patients, the dissection involved the left anterior descending or circumflex artery, and it extended to the left main coronary artery in 6 patients. Intravascular ultrasound or optical coherence tomography helped to confirm diagnosis and guide treatment in 46% of cases. Seven women were managed clinically; percutaneous coronary intervention was performed in five cases, and coronary artery bypass grafting was performed in one patient. CONCLUSION: In these 13 cases of P-SCAD, clinical presentation commonly included acute myocardial infarction and cardiogenic shock. Multivessel dissections and involvement of the left coronary artery and left main coronary artery were highly prevalent. Clinicians must be aware of angiographic appearances of P-SCAD for prompt diagnosis and management in these high-risk patients.

The REBECGA brazilian registry of pregnancy and heart disease: rationale and design

BACKGROUND: Maternal mortality rates in Brazil remain above the goals established by the United Nations Sustainable Development Goals. Heart disease is estimated to affect 4% of all pregnancies and remains by itself the main indirect obstetric cause of maternal death. In the last decades, a significant improvement in the prognosis of heart diseases has made pregnancy possible in women with heart disease and provided better maternal and fetal outcomes. OBJECTIVES: To establish a multicenter Brazilian Registry of pregnant women with heart disease; to study the causes of immediate and late maternal mortality; and to assess the prevalence of heart disease in the country's macro-regions. METHODS: This is an observational study, with retrospective and prospective stages, of the clinical and obstetric progression of pregnant women with heart disease. These women consecutively received care during pregnancy and will be followed up for up to a year after delivery at public and private hospitals with infrastructure for the execution of this project, a principal investigator, and approval by Ethics and Research Committees. RESULTS: Our results will be presented after data collection and statistical analysis, aiming to demonstrate immediate and late maternal mortality rates, as well as the prevalence of heart disease in the country and its cardiovascular and obstetric complications during pregnancy. CONCLUSIONS: REBECGA will be the Brazilian Registry of heart disease and pregnancy and it will contribute to planning preventive measures, raising financial resources for the improvement of high-risk prenatal care, and reducing immediate and late maternal mortality due to heart disease.

[Transient ventricular dysfunction (Takotsubo cardiomyopathy)]. / Síndrome da disfunção apical reversível (Takotsubo).

The patient was a male with myasthenia gravis, hospitalized with acute respiratory failure due to decompensation of the underlying disease. He evolved with findings suggestive of acute myocardial infarction, with electrocardiographic and enzymatic alterations compatible with that diagnosis. The patient underwent emergency coronary angiography, which showed no severe coronary obstruction, although his left ventricle had significant systolic dysfunction with characteristic alterations, on ventriculography, of the syndrome described as transient ventricular dysfunction or Takotsubo syndrome. On evolution, complete recovery of the electrocardiographic alterations and systolic ventricular function assessed on echocardiography occurred, confirming the syndrome.

The Impact of Cardiac Diseases during Pregnancy on Severe Maternal Morbidity and Mortality in Brazil.

BACKGROUND: To evaluate maternal heart disease as a cause or complicating factor for severe morbidity in the setting of the Brazilian Network for Surveillance of Severe Maternal Morbidity. METHODS AND FINDINGS: Secondary data analysis of this multicenter cross-sectional study was implemented in 27 referral obstetric units in Brazil. From July 2009 to June 2010, a prospective surveillance was conducted among all delivery hospitalizations to identify cases of severe maternal morbidity (SMM), including Potentially Life-Threatening Conditions (PLTC) and Maternal Near Miss (MNM), using the new criteria established by the WHO. The variables studied included: sociodemographic characteristics, clinical and obstetric history of the women; perinatal outcome and the occurrence of maternal outcomes (PLTC, MNM, MD) between groups of cardiac and non-cardiac patients. Only heart conditions with hemodynamic impact characterizing severity of maternal morbidity were considered. 9555 women were included in the Network with severe pregnancy-related complications: 770 maternal near miss cases and 140 maternal death cases. A total of 293 (3.6%) cases were related to heart disease and the condition was known before pregnancy in 82.6% of cases. Maternal near miss occurred in 15% of cardiac disease patients (most due to clinical-surgical causes, p<0.001) and 7.7% of non-cardiac patients (hemorrhagic and hypertensive causes, p<0.001). Maternal death occurred in 4.8% of cardiac patients and in 1.2% of non-cardiac patients, respectively. CONCLUSIONS: In this study, heart disease was significantly associated with a higher occurrence of severe maternal outcomes, including maternal death and maternal near miss, among women presenting with any severe maternal morbidity.

Pregnancy follow-up and outcome in a patient with Takayasu's arteritis.

We describe here the pregnancy follow-up and outcome in a patient with Takayasu's arteritis, with a detailed account of the complications during gestation and delivery and the impact of the disease on the newborn's health.

Monitorização ambulatorial de pressão arterial em gestantes normotensas / Ambulatory blood pressure monitoring in normotensive pregnant women

As controvérsias sobre os padrões pressóricos durante a gravidez normal justificam a realização de estudos para melhor entender a questão. O objetivo deste estudo foi conhecer as variações normais da pressão arterial (PA), através da monitorização ambulatorial da pressão arterial (MAPA), em gestantes saudáveis numa capital da região norte do Brasil. Foram estudadas 89 gestantes normotensas, nulíparas ou multíparas, de 3 centros obstétricos da cidade de Belém (PA). As gestantes foram divididas em três grupos, segundo a idade gestacional: Grupo 1, composto por 25 grávidas, entre 6 e 13 semanas de gestação; Grupo 2, por 32 grávidas, entre 14 e 25 semanas; e Grupo 3, por 32 grávidas, entre 28 e 38 semanas de gestação. As 89 gestantes apresentavam idade entre 18 e 35 anos (mediana de 24 anos). Não houve diferenças significantes entre o número de nulíparas e multíparas (p = 0,5555). Quanto às variáveis da MAPA analisadas (média de 24 horas) houve diferenças estatisticamente significantes apenas em três delas: PA sistólica no Grupo 3 (aumento), PA diastólica no Grupo 2 (redução) e descenso noturno diastólico no Grupo 1 (aumento). Podemos concluir que em grávidas normotensas, os parâmetros da MAPA avaliados tiveram comportamento similar aos padrões de normalidade considerados para a população geral.

Controversies regarding blood pressure patterns during normal pregnancy justify studies for their better understanding. The objective of this study was to verify normal blood pressure (BP) variations by means of ambulatory blood pressure monitoring (ABPM) in healthy pregnant women in the capital of a northern Brazilian state. A total of 89 normotensive nulliparous or multiparous pregnant women from 3 obstetric centers in the city of Belém ­ State of Pará, were studied. The pregnant women were divided into three groups, according to their gestational age: Group 1, comprising 25 pregnant women between 6 and 13 weeks of gestation; Group 2, with 32 pregnant women between 14 and 25 weeks of gestation; and Group 3, with 32 pregnant women between 28 and 38 weeks of gestation. The ages of the 89 pregnant women ranged from 18 to 35 years (median of 24,0 years). There was no significant difference between the number of nulliparae and multiparae (p = 0.5555). As regards the ABPM variables analyzed (mean of 24 hours), statistically significant differences were observed in only three of them: systolic BP in Group 3 (increase); diastolic BP in Group 2 (decrease), and diastolic nocturnal dip in Group 1 (increase). In conclusion, in normotensive pregnant women the variation of the ABPM parameters analyzed was similar to the normal patterns observed in the general population.

Gestação em portadora de arterite de Takayasu / Pregnancy follow-up and outcome in a patient with Takayasu's arteritis

No presente relato, que descreve a gestação de paciente portadora de arterite de Takayasu, serão avaliadas a interação dessa afecção com a gravidez e as intercorrências materno-fetais, do parto e do recém-nascido.

We describe here the pregnancy follow-up and outcome in a patient with Takayasu's arteritis, with a detailed account of the complications during gestation and delivery and the impact of the disease on the newborn's health.

Marca-passo cardíaco e gestação: estudo retrospectivo em três centros de São Paulo / Cardiac pacemaker and gestation: retrospective study in three centers of São Paulo

Objetivo: Objetivou-se, neste estudo, avaliar as complicações maternas e fetais (clínicas e obstétricas) em mulheres portadoras de marca-passo cardíaco, assim como, a relação entre os modos de estimulação cardíaca(atrial, ventricular ou atrioventricular) e a evolução da gestação quanto às intercorrências materno-fetais, Peso de RN e APGAR. Materiais e métodos: Pesquisa retrospectiva embasada em análise de prontuários médicos de gestantes portadoras de marca-passo cardíaco, acompanhadas nos serviços de Cardiopatia e Gravidez do IDPC, INCOR e HSP (1980 a 2003). Resultado: Analisaram-se 65 gestações em 52 mulheres. 12 pacientes tiveram implante do marca-passo durante a gravidez. A mostra foi dividida em dois grupos, segundo o modo de estimulação cardíaca. Grupo 1:> 25 gestações no modo atrioventricular. Grupo 2: 40 gestações no modo ventricular. Os dois grupos foram semelhantes do ponto de vista estatístico. Não houve diferença significativa entre os modos de estimulação e o peso dos recém-nascidos (p=0,765), bem com em relação à nota de Apgar (p=0,287). Observamos correlação negativa significante (p=0.017) entre o tempo decorrido entre o implante do marca-passo e a gestação, com o peso dos recém-nascidos. Conclusão: Concluiu-se que, em ambos os modos de estimualaçao cardíaca houve recém-nascidos com boas condições de nascimento e com peso adequado para a idade gestacional. Quanto maior o tempo decorrido entre o implante de marca-passo e a gestacional, menor foi o peso dos recém-nascidos.

Síndrome da disfunção apical reversível (Takotsubo) / Transient ventricular dysfunction (Takotsubo cardiomyopathy)

Homem portador de miastenia gravis, internado por descompensação da doença de base, em insuficiência respiratória aguda. Na evolução, apresentou quadro sugestivo de infarto agudo do miocárdio, com alterações eletrocardiográficas e enzimáticas compatíveis com o diagnóstico. Submetido a coronariografia de urgência, não evidenciou obstrução coronariana grave, entretanto o ventrículo esquerdo apresentava disfunção sistólica importante, com alteração característica pela ventriculografia da síndrome descrita como disfunção ventricular transitória ou síndrome de Takotsubo. Na evolução, houve completa recuperação das alterações eletrocardiográficas e da função ventricular sistólica avaliada pelo ecocardiograma, confirmando a síndrome.

Mortalidade materna por cadiopatia / Maternal mortality due to heart disease

Realizou-se estudo retrospectivo da mortalidade materna por cadiopatia, no período de janeiro de 1979 a dezembro de 1989. Dentre um total de 16.423 internaçöes, houve 694 gestantes com o diagnóstico de cardiopatia (4,2%). No mesmo período, ocorrerram 51 óbitos maternos, correspondendo a um coeficiente de mortalidade materna de 428,2/100.000 nascidos vivos. Houve 12 óbitos maternos por cardiopatia. A análise estatística permitiu a identificaçäo de alguns fatores associados a maior risco de morte nas pacientes cardiopatas: primeira gravidez, primiparidade, ausência de assistência pré-natal, realizaçäo de cirurgia cardíaca anterior à gravidez e/ou gestaçäo. O maior número de mortes ocorreu no puerpério. A classificaçäo funcional (NYHA) näo se constituiu em parâmetro seguro para avaliar o prognóstico materno, pois 91,7 por cento dos casos de óbito foram incluídos no grupo considerado favorável (classes I e II) ao iniciar a gestaçäo

Cirurgia cardíaca com circulação extracorpórea em gestantes. Análise da evolução materno-fetal / Cardiopulmonary Bypass Surgery in Pregnants. Analysis of Maternal and Fetal Outcome

PURPOSE--To analyze maternal and fetal outcome in pregnant undergone to cardiac surgery. METHODS--We studied the evolution of 30 pregnant women submitted to cardiac surgery at the Hospital São Paulo, between Jan/81 and Dec/92 and, further, attended at this Hospital till the parturition. The following variables were analyzed: cardiopulmonary bypass, time of the procedure and time of the anoxia, patient temperature, surgical complications, and neonatal, maternal and fetal outcomes. RESULTS--All patients had rheumatic heart disease and, in 17, mitral stenosis was the main anatomic abnormality. Mitral commissurotomy was performed in 24 patients, double comissurotomy (mitral and aortic) in 1 patient and valve replacement was performed in 5. Cardiopulmonary bypass was utilized in all procedure; occurrence of surgical complications (p < 0.001) and the prolonged surgical time (p = 0.009) were related to the fetal mortality. There was 4 (13.3) maternal deaths and 10 (33.3) fetal deaths related to the surgery. CONCLUSION--The indication of cardiac surgery in pregnant women is heart failure, refractory to conventional therapy; cardiopulmonary bypass is associated with high fetal mortality.

Anticoagulaçäo na gravidez / Anticoagulation during pregnancy

A anticoagulaçäo durante a gravidez representa um dilema clínico, pois se associa a riscos maternos e fetais.Está indicada para tratamento e profilaxia da trombose venosa profunda e na prenvençäo e no tratamento de fenômenos tromboembólicos associados a valvopatiase a próteses valvares cardíacas.Até o presente, näo existe um esquema terapêutico definitivo, especialmente para as pacientes portadoras de próteses valvares cardíacas mecânicas, pois os esquemas terapêuticos que têm por objetivos diminuir os riscos fetais aumentam os risco maternos; da mesma forma, as tentativas de minorar os riscos maternos aumentam os riscos fetais.É apresentada breve revisäo da literatura e um dos esquemas terapêuticos utilizados em nosso meio.

Situaçöes especiais da reanimaçäo cardiorrespiratória / Special situations in cardiopulmonary reanimation

O presente artigo discute a reanimaçäo cardio-respiratória em três situaçöes distintas: o acidente vascular cerebral, a hipotermia e a gravidez. O acidente vascular cerebral é uma das principais causas de mortalidade e morbidade em países desenvolvidos. Seu tratamento precoce visa diminuir esses altos índices. Säo discutidas estratégias terapêuticas, com ênfase aos estudos mais recentes de uso de trombólitos. A hipotermia acidental é enfocada como alerta aos médicos que trabalham em serviço de urgência como diagnóstico diferencial. Säo abordadas as alteraçöes metabólicas, bem como aspectos terapêuticos. A ressuscitaçäo cardiopulmonar de gestantes é uma situaçäo única, pois além da tentativa de salvaguardar a vida materna, existe a preocupaçäo de garantir a sobrevida fetal. Na ressuscitaçäo cardiopulmonar da gestante, todos as manobras terapêuticas convencionais devem ser aplicadas sem modificaçöes. A realizaçäo de parto cesáreo de emergência deve ser considerada se a ciruculaçäo näo for restabelecida em 4 a 5 minutos. Fatores importantes a serem considerados säo: viabilidade fetal, equipe treinada nos procedimentos, e suporte apropriado para a mäe e o recém-nascido.