Application of computational quantum chemistry to chemical processes involved in mass spectrometry

The field of application of mass spectrometry (MS) has increased considerably due to the development of ionization techniques. Other factors that have stimulated the use of MS are the tandem mass spectrometry (MS/MS) and sequential mass spectrometry (MSn) techniques. However, the interpretation of the MS/MS and MSn data may lead to speculative conclusions. Thus, various quantum chemical methods have been applied for obtaining high quality thermochemical data in gas phase. In this review, we show some applications of computational quantum chemistry to understand the formation and fragmentation of gaseous ions of organic compounds in a MS analysis.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPESPCNP

Ensaios de inseticidas sistêmicos para animais, usando cães e triatomíneos

The following insecticides were mixed with industrialized dog food: Phoxim, Chlorphoxim, Themephos (Abate), Decamethrin, Lindane, and DDT. The insecticidal effect in the blood was tested with Triatoma infestans nymphs and adults. Positive results were obtained with Phoxim and Themephos. Chlorphoxim and Lindane at efficient levels became unpalatable. Decamethrin and DDT had no lethal effect upon the insects at the levels of concentration tolerated by the dogs.Foram incluídos em rações comerciais, e dados a cães, os seguintes inseticidas: Phoxim, Chlorphoxim, Themephos (Abate), Decametrina, Lindano e DDT. A ação inseticida, no sangue, foi testada com ninfas e adultos de Triatoma infestans. Foram obtidos bons resultados com o Phoxim e o Themephos. O Chlorphoxim e o Lindano, nas doses eficientes, mostraram-se pouco palatáveis e a Decametrina e o DDT, nas concentrações aceitas pelos cães, não tiveram ação letal sobre os insetos

The Analyticity of a Generalized Ruelle's Operator

In this work we propose a generalization of the concept of Ruelle operator for one dimensional lattices used in thermodynamic formalism and ergodic optimization, which we call generalized Ruelle operator, that generalizes both the Ruelle operator proposed in [BCLMS] and the Perron Frobenius operator defined in [Bowen]. We suppose the alphabet is given by a compact metric space, and consider a general a-priori measure to define the operator. We also consider the case where the set of symbols that can follow a given symbol of the alphabet depends on such symbol, which is an extension of the original concept of transition matrices from the theory of subshifts of finite type. We prove the analyticity of the Ruelle operator and present some examples

INTOXICAÇÃO NATURAL DE BOVINOS LEITEIROS POR Cestrum laevigatum (SOLANACEAE) NO AGRESTE DE PERNAMBUCO – BRASIL

The aim of the present study was to report an outbreak of natural poisoning by Cestrum laevigatum in dairy cattle in the “Agreste” region of Pernambuco state, Brazil. Epidemiological and clinical data were collected. Among a lot of 60 cows, eight became ill and four died. Two cows underwent necropsy, during which fragments of the central nervous system, liver, gall bladder, spleen and kidney were collected for histopathlogical analysis. Blood samples were collected for hematological and biochemical tests. The animals exhibited apathy, muscle tremors, reduced appetite, different degrees of dehydration and compromised reticulorumen dynamics as well as a small quantity of dry feces with the presence of mucus and blood. The laboratory exams revealed an increase in serum activity of aspartate aminotransferase and gamma glutamyltransferase as well as hypoalbuminemia. The necropsy revealed an enlarged liver and cutting surface with a nutmeg aspect as well as areas of hemorrhaging in the heart, trachea, abomasum, spleen, intestine and bladder. The microscopic analysis revealed centrilobular hepatic necrosis associated to accentuated hemorrhaging. These findings characterized poisoning by Cestrum laevigatum and led to the adoption of control and prevention measures

ACALASIA NA DOENÇA DE CHAGAS É DIFERENTE DE ACALASIA IDIOPÁTICA? EXPERIÊNCIA DO HOSPITAL DE CLÍNICAS DE PORTO ALEGRE

Objetive: The objective of this study is to evaluate the differences between achalasia in Chagas’ disease and idiopathic achalasia in patients admitted to the Hospital de Clínicas de Porto Alegre, by analyzing epidemiologic, clinic, radiologic and manometric findings.Methods: Patients referred to the Hospital de Clinicas de Porto Alegre between November 1996 and December 2001 with suspicion of achalasia, later confirmed by esophageal manometry, were included in the study. In addition to manometric and radiologic findings, patients were assessed for age, sex, symptomsand symptomatic period.Results: Among 51 patients, nine (18%) presented positive serology for Chagas’ disease and 42 (82%) presented negative serology. The latter were considered carriers of idiopathic achalasia. The mean age of patients with achalasia in Chagas’ disease was 62 ± 15 years, while the mean age in the idiopathic group was 43 ± 18 years (P < 0.02). The symptomatic period for patients with achalasia in Chagas’ disease was 74 ± 47 months, and in the idiopathic group, 49 ± 35 months (P < 0.05). Dysphagia, regurgitation, thoracic pain and weight loss, values at the lower esophageal sphincter (basal pressure, post-deglutitive relaxation pressure/duration and total length) and at the esophageal body (amplitude and duration of the post-deglutitive waves) were similar in both groups.Conclusions: The only statistically significant differences found between the two groups were age and length of the symptomatic period, significantly greater in patients with achalasia in Chagas’ disease. These data suggest a greater resistance to the symptoms in older patients.Objetivo: O presente trabalho tem como objetivo avaliar as diferenças entre a acalasia chagásica e a idiopática em pacientes do Hospital de Clínicas de Porto Alegre, através da análise de achados epidemiológicos, clínicos, radiológicos e manométricos.Métodos: Foram estudados pacientes encaminhados ao Hospital de Clínicas de Porto Alegre, entre novembro de 1996 e dezembro de 2001, com suspeita de acalasia, posteriormente, confirmada por manometria esofágica. Além das características manométricas e radiológicas, os pacientes foram avaliados quanto a idade, sexo, sintomas e tempo de evolução.Resultados: Entre 51 pacientes, nove (18%) tiveram sorologia positiva para doença de Chagas e 42 (82%) sorologia negativa. Indivíduos com sorologia negativa foram considerados portadores de acalasia idiopática. Pacientes com acalasia chagásica tinham média de idade de 62 ± 15 anos e os com idiopática 43 ± 18 anos (P < 0,02). O período de evolução dos sintomas em pacientes com acalasia chagásica foi de 74 ± 47 meses e nos idiopáticos 49 ± 35 meses (P < 0,05). Disfagia, regurgitação, dor torácica e emagrecimento, valores do esfíncter esofágico inferior (pressão basal, pressão e duração de relaxamento pós-deglutição e comprimento total) e do corpo esofágico (amplitude e duração das ondas pós-deglutição) foram similares em ambos os grupos.Conclusões: As únicas diferenças estatisticamente significativas encontradas entre os dois grupos foram a média de idade e o período de evolução dos sintomas, maiores nos pacientes chagásicos. Esses dados permitem especular sobre uma maior tolerância aos sintomas nos pacientes com idade mais avançada

Aedes aegypti salivary gland extract alleviates acute itching by blocking TRPA1 channels

Aedes aegypti (Ae. aegypti) saliva induces a variety of anti-inflammatory and immunomodulatory activities. Interestingly, although it is known that mosquito bites cause allergic reactions in sensitised hosts, the primary exposure of humans to Ae. aegypti does not evoke significant itching. Whether active components in the saliva of Ae. aegypti can counteract the normal itch reaction to injury produced by a histaminergic or non-histaminergic pathway in vertebrate hosts is unknown. This study investigated the effects of Ae. aegypti mosquito salivary gland extract (SGE) on sensitive reactions such as itching and associated skin inflammation. Acute pruritus and plasma extravasation were induced in mice by the intradermal injection of either compound 48/80 (C48/80), the Mas-related G protein-coupled receptor (Mrgpr) agonist chloroquine (CQ), or the transient receptor potential ankyrin 1 (TRPA1) agonist allyl isothiocyanate (AITC). The i.d. co-injection of Ae. aegypti SGE inhibited itching, plasma extravasation, and neutrophil influx evoked by C48/80, but it did not significantly affect mast cell degranulation in situ or in vitro. Additionally, SGE partially reduced CQ- and AITC-induced pruritus in vivo, suggesting that SGE affects pruriceptive nerve firing independently of the histaminergic pathway. Activation of TRPA1 significantly increased intracellular Ca2+ in TRPA-1-transfected HEK293t lineage, which was attenuated by SGE addition. We showed for the first time that Ae. aegypti SGE exerts anti-pruriceptive effects, which are partially regulated by the histamine-independent itch TRPA1 pathway. Thus, SGE may possess bioactive molecules with therapeutic potential for treating nonhistaminergic itch

Tele-electrocardiography and bigdata: the CODE (Clinical Outcomes in Digital Electrocardiography) study

Digital electrocardiographs are now widely available and a large number of digital electrocardiograms (ECGs) have been recorded and stored. The present study describes the development and clinical applications of a large database of such digital ECGs, namely the CODE (Clinical Outcomes in Digital Electrocardiology) study. ECGs obtained by the Telehealth Network of Minas Gerais, Brazil, from 2010 to 17, were organized in a structured database. A hierarchical free-text machine learning algorithm recognized specific ECG diagnoses from cardiologist reports. The Glasgow ECG Analysis Program provided Minnesota Codes and automatic diagnostic statements. The presence of a specific ECG abnormality was considered when both automatic and medical diagnosis were concordant; cases of discordance were decided using heuristisc rules and manual review. The ECG database was linked to the national mortality information system using probabilistic linkage methods. From 2,470,424 ECGs, 1,773,689 patients were identified. After excluding the ECGs with technical problems and patients <16 years-old, 1,558,415 patients were studied. High performance measures were obtained using an end-to-end deep neural network trained to detect 6 types of ECG abnormalities, with F1 scores >80% and specificity >99% in an independent test dataset. We also evaluated the risk of mortality associated with the presence of atrial fibrillation (AF), which showed that AF was a strong predictor of cardiovascular mortality and mortality for all causes, with increased risk in women. In conclusion, a large database that comprises all ECGs performed by a large telehealth network can be useful for further developments in the field of digital electrocardiography, clinical cardiology and cardiovascular epidemiology