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1.
J Dent Res ; 102(10): 1114-1121, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37317840

RESUMO

The dental profession has endured unprecedented disruption amid COVID-19. Novel stressors have included a high risk of occupational exposure to COVID-19, financial losses, and stricter infection prevention and control requirements. The present study investigated the longitudinal impact of COVID-19 on the stress and anxiety levels of a cohort of Canadian dentists (N = 222) between September 2020 and October 2021. Salivary cortisol was selected as a biomarker of mental stress, and 10 sets of monthly saliva samples (2,131 in total) were self-collected, sent to our laboratory in prepaid courier envelopes, and analyzed by enzyme-linked immunosorbent assay. To assess COVID-19 anxiety, 9 monthly online questionnaires were administered, comprising a general COVID-19 anxiety instrument and 3 items regarding the impact of dentistry-related factors. Bayesian log-normal mixed effect models were fitted to estimate the longitudinal trajectory of salivary cortisol levels and their association with the disease burden of COVID-19 in Canada. After accounting for age, sex, vaccination status, and the diurnal rhythm of cortisol secretion, a modest positive association was found between dentists' salivary cortisol levels and the count of COVID-19 cases in Canada (96% posterior probability). Similarly, the self-reported impact of dentistry-related factors, such as fear of getting COVID-19 from a patient or coworker, was greatest during peaks of COVID-19 waves in Canada; however, general COVID-19 anxiety decreased consistently throughout the study period. Interestingly, at all collection points, the majority of participants were not concerned about personal protective equipment. Overall, participants reported relatively low rates of psychological distress symptoms in relation to COVID-19, a result that should be reassuring for the dental community. Our findings strongly suggest a link between self-reported and biochemical measurements of stress and anxiety in Canadian dentists during the COVID-19 pandemic.


Assuntos
COVID-19 , Humanos , Hidrocortisona , Pandemias , Teorema de Bayes , Canadá/epidemiologia , Ansiedade/diagnóstico , Ansiedade/psicologia , Inquéritos e Questionários , Odontólogos/psicologia
2.
Osteoarthritis Cartilage ; 30(7): 935-944, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35257862

RESUMO

OBJECTIVE: This systematic review investigated whether people with patellofemoral osteoarthritis (PFOA) have muscle strength, volume, and activation around the hip and knee that is different from asymptomatic controls. METHODS: Searches were carried out in five electronic databases, with terms related to PFOA, including muscle strength, volume and activation. Only studies with at least one group with symptomatic PFOA and one asymptomatic group were included. The methodological quality of the studies was assessed using the Downs and Black checklist. Certainty of evidence was assessed using the GRADE methodology. Using the random effects model, a meta-analysis was performed when there were at least two studies reporting the same domain. RESULTS: Eight studies (250 participants) met the inclusion criteria. Subjects with PFOA had weaker hip abduction (SMD -0.96; 95%CI = -1.34 to -0.57), hip external rotation (-0.55;-1.07 to -0.03), hip extension (-0.72;-1.16 to -0.28), and knee extension (-0.97;-1.41 to -0.53) when compared to asymptomatic controls. People with PFOA also presented with smaller volumes of the gluteus medius, gluteus minimus, tensor fascia lata, vastus medialis (VM), vastus lateralis (VL) and rectus femoris when compared to asymptomatic controls. Also, people with PFOA presented with changes in muscle activation for the VL, VM and gluteus maximus (GMax) when compared to asymptomatic controls. CONCLUSION: People with PFOA present with lower strength and volume of the hip and quadriceps muscles and altered muscle activation of the VM, VL and GMax during ascending and descending stairs when compared to asymptomatic controls. However, the certainty of these findings are very low. TRIAL REGISTRATION NUMBER: PROSPERO systematic review protocol (ID = CRD42020197776).


Assuntos
Osteoartrite do Joelho , Eletromiografia , Humanos , Joelho , Articulação do Joelho , Força Muscular , Músculo Esquelético , Músculo Quadríceps
3.
Rev Sci Instrum ; 92(6): 064101, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243508

RESUMO

With the aim of improving phototherapy for neonatal jaundice (hyperbilirubinemia), this study investigates the degradation of unconjugated bilirubin under irradiance by conventional light and by white, red, green, and blue LED sources in vitro. The absorption spectra of bilirubin under these different light sources are compared. The results demonstrate that white LED phototherapy promotes more efficient bilirubin degradation than conventional blue-light therapy. This study provides a basis for the design of novel phototherapy devices for the treatment of hyperbilirubinemia.


Assuntos
Icterícia Neonatal , Fototerapia , Bilirrubina , Humanos , Recém-Nascido , Luz
4.
Trials ; 22(1): 208, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33712076

RESUMO

BACKGROUND: Arterial hypotension induced by general anesthesia is commonly identified as a risk factor of morbidity, especially neurological, after cardiac or noncardiac surgery in adults and children. Intraoperative hypotension is observed with sevoflurane anesthesia in children, in particular in neonates, infants younger than 6 months, and preterm babies. Ephedrine is commonly used to treat intraoperative hypotension. It is an attractive therapeutic, due to its dual action on receptors alpha and beta and its possible peripheral intravenous infusion. There are few data in the literature on the use of ephedrine in the context of pediatric anesthesia. The actual recommended dose of ephedrine (0.1 to 0.2 mg/Kg) frequently leads to a therapeutic failure in neonates and infants up to 6 months of age. The use of higher doses would probably lead to a better correction of hypotension in this population. The objective of our project is to determine the optimal dose of ephedrine for the treatment of hypotension after induction of general anesthesia with sevoflurane, in neonates and infants up to 6 months of age. METHODS: The ephedrine study is a prospective, randomized, open-label, controlled, dose-escalation trial. The dose escalation consists of 6 successive cohorts of 20 subjects. The doses studied are 0.6, 0.8, 1, 1.2, and 1.4 mg/kg. The dose chosen as the reference is 0.1 mg/kg, the actual recommended dose. Neonates and infants younger than 6 months, males and females, including preterm babies who undergo a surgery with general anesthesia inducted with sevoflurane were eligible. Parents of the subject were informed. Then, the subjects were randomized if presenting a decrease in mean blood pressure superior to 20% of their initial mean blood pressure (before induction of anesthesia), despite a vascular filling with sodium chloride 0.9%. The primary outcome is the success of the therapy defined as an mBP superior to 80% of the baseline mBP (prior to anesthesia) within 10 min post ephedrine administration. The subjects were followed-up for 3 days postanesthesia. DISCUSSION: This study is the first randomized, controlled trial intending to determine the optimal dose of ephedrine to treat hypotension in neonates and infants below 6 months old. TRIAL REGISTRATION: ClinicalTrials.gov NCT02384876 . Registered on March 2015.


Assuntos
Efedrina , Hipotensão , Adulto , Anestesia Geral/efeitos adversos , Pressão Sanguínea , Criança , Efedrina/efeitos adversos , Feminino , Humanos , Hipotensão/induzido quimicamente , Hipotensão/diagnóstico , Hipotensão/tratamento farmacológico , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Vasoconstritores/efeitos adversos
5.
Childs Nerv Syst ; 37(1): 211-215, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32661646

RESUMO

BACKGROUND: Acute flaccid myelitis (AFM) syndrome consists of loss of lower motor neurons following a viral infection, with preserved sensory function. It usually affects the upper limbs asymmetrically, with proximal more than distal muscle involvement. METHODS: Five cases were surgically treated with nerve transfers: spinal accessory to suprascapular nerve transfer (4 patients), branch of radial nerve to axillary nerve transfer (Somsak's procedure) (2 patients), and transfer of a fascicle of the ulnar nerve to the motor branch to the biceps (Oberlin's procedure) (1 patient). RESULTS: Motor improvement was seen in three cases. Widespread motor involvement was associated with poor outcome. CONCLUSION: This small series of cases reinforces that nerve transfers are a reliable option for treatment of selected children with AFM.


Assuntos
Viroses do Sistema Nervoso Central , Mielite , Transferência de Nervo , Doenças Neuromusculares , Criança , Humanos , Mielite/cirurgia , Nervo Ulnar
7.
Curr Neurovasc Res ; 16(4): 291-300, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31633476

RESUMO

BACKGROUND: In the developing cerebral cortex, Radial Glia (RG) multipotent neural stem cell, among other functions, differentiate into astrocytes and serve as a scaffold for blood vessel development. After some time, blood vessel Endothelial Cells (ECs) become associated with astrocytes to form the neurovascular Blood-Brain Barrier (BBB) unit. OBJECTIVE: Since little is known about the mechanisms underlying bidirectional RG-ECs interactions in both vascular development and astrocyte differentiation, this study investigated the impact of interactions between RG and ECs mediated by secreted factors on EC maturation and gliogenesis control. METHODS: First, we demonstrated that immature vasculature in the murine embryonic cerebral cortex physically interacts with Nestin positive RG neural stem cells in vivo. Isolated Microcapillary Brain Endothelial Cells (MBEC) treated with the conditioned medium from RG cultures (RG-CM) displayed decreased proliferation, reduction in the protein levels of the endothelial tip cell marker Delta-like 4 (Dll4), and decreased expression levels of the vascular permeability associated gene, plasmalemma vesicle-associated protein-1 (PLVAP1). These events were also accompanied by increased levels of the tight junction protein expression, zonula occludens-1 (ZO-1). RESULTS: Finally, we demonstrated that isolated RG cells cultures treated with MBEC conditioned medium promoted the differentiation of astrocytes in a Vascular Endothelial Growth Factor-A (VEGF-A) dependent manner. CONCLUSION: These results suggest that the bidirectional interaction between RG and ECs is essential to induce vascular maturation and astrocyte generation, which may be an essential cell-cell communication mechanism to promote BBB establishment.


Assuntos
Astrócitos/citologia , Barreira Hematoencefálica/citologia , Diferenciação Celular/fisiologia , Células Endoteliais/citologia , Animais , Encéfalo/citologia , Encéfalo/metabolismo , Permeabilidade Capilar/fisiologia , Células Cultivadas , Camundongos , Células-Tronco Neurais/citologia , Neurogênese/fisiologia
8.
Eur Arch Paediatr Dent ; 20(6): 603-607, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31087255

RESUMO

PURPOSE: This study investigated whether the report of mothers about the amount of dentifrice applied on a toothbrush could be a reliable method to estimate the inadvertent use of dentifrices. METHODS: A cross-sectional study was conducted in a randomly selected sample of 334 mothers of children enrolled in public day care centres of a city in the Brazilian northeast. Initially, the mothers chose the figure corresponding to the amount of dentifrice used during their children's daily toothbrushing. Then, they simulated real-life conditions with the toothbrush routinely used to brush the children's teeth. The amount of dentifrice on toothbrush was weighted using an analytical scale. Data were analysed by the Kruskal-Wallis followed by the Dunn test (α = 0.05). RESULTS: The weight of dentifrice on the toothbrush was high (> 0.3 g), mainly considering the categories 'covered only' and 'completely covered' that showed no statistical difference (p > 0.05). The proportion of agreement between the mothers' reports and the weight of dentifrice on the toothbrush was 0.23 (CI 0.18-0.28). CONCLUSION: The mothers' report regarding the amount of dentifrice on the toothbrush by demonstrative figures was not a reliable method to estimate the inadvertent ingestion of fluoride from dentifrices.


Assuntos
Dentifrícios , Brasil , Cariostáticos , Criança , Estudos Transversais , Feminino , Fluoretos , Humanos , Escovação Dentária
9.
J Cell Physiol ; 234(9): 16275-16280, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30805930

RESUMO

BACKGROUND: Patients with chronic kidney disease (CKD) have a severe vitamin D deficiency and increasing epidemiological data suggesting that this deficiency may play a role in overall morbidity and mortality associated with CKD. It is known that vitamin D regulates the immune system, however, in dialysis patients this deficiency and the modulation of proinflammatory cells is unclear. Among these, monocytes arouse interest considering they constitutively express vitamin D receptors. AIM: This study aimed the evaluation of monocytic profile in CKD patients according to vitamin D levels. METHODS: Patients in hemodialysis (HD) were divided into two groups, regarding vitamin D levels: Group 1, vitamin D <26 ng/ml (n = 15) and Group 2, vitamin D ≥26 ng/ml (n = 18). Whole blood was collected aiming evaluation of (a) monocytic populations through CD14 and CD16 expression, (b) reactive oxygen species (ROS) generation, and (c) apoptosis. RESULTS: We observed that in Group 1, when compared to Group 2, there was a significant increase in intermediate monocytes (CD14++ CD16 + ; 34.7 ± 31.6 vs. 12.1 ± 6.3; p = 0.006, respectively) and decrease in classical ones (CD14 ++ CD16 - ; 45.3 ± 31.8 vs. 70.4 ± 25.1; p = 0.017, respectively). There was no difference between groups regarding nonclassical monocytes (CD14 + CD16 ++ ), as well as to apoptosis and to ROS generation. CONCLUSION: This study suggests that HD patients with lower vitamin D levels might have an intensified inflammatory outline as intermediate monocytes with an inflammatory pattern are increased in this population, when compared with patients with higher levels of vitamin D.

10.
J Mol Model ; 24(9): 236, 2018 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-30116995

RESUMO

Single-molecules have been widely investigated in the last decades due to their promises as devices in molecular electronics. One of the advantages in the use of natural compounds in molecular electronics is the economy of material and molecular synthesis, which makes the process both cheaper and self-sustaining. Although many studies have considered electronic transport in single molecules, there are few studies associated with isomeric effects in biologically appealing systems. In the present work, we have studied ballistic electron transport in two isomeric forms of a retinol molecule: 11-cis and all-trans-retinol. The molecules were connected between two Au(111) electrodes and calculations were performed with the NEGF-DFT methodology. Current-voltage, differential conductance, and rectification curves were obtained and compared for two structures. While 11-cis-retinol shows a more symmetrical current-voltage curve, all-trans-retinol acts as molecular diode for low applied voltages. Our results suggest that a simple isomeric effect modulates the molecular device from nanowires to diodes with potential applications as field-effect transistors.

11.
Sci Rep ; 8(1): 12774, 2018 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-30143723

RESUMO

Zika virus (ZIKV) is associated with brain development abnormalities such as primary microcephaly, a severe reduction in brain growth. Here we demonstrated in vivo the impact of congenital ZIKV infection in blood vessel development, a crucial step in organogenesis. ZIKV was injected intravenously in the pregnant type 2 interferon (IFN)-deficient mouse at embryonic day (E) 12.5. The embryos were collected at E15.5 and postnatal day (P)2. Immunohistochemistry for cortical progenitors and neuronal markers at E15.5 showed the reduction of both populations as a result of ZIKV infection. Using confocal 3D imaging, we found that ZIKV infected brain sections displayed a reduction in the vasculature density and vessel branching compared to mocks at E15.5; altogether, cortical vessels presented a comparatively immature pattern in the infected tissue. These impaired vascular patterns were also apparent in the placenta and retina. Moreover, proteomic analysis has shown that angiogenesis proteins are deregulated in the infected brains compared to controls. At P2, the cortical size and brain weight were reduced in comparison to mock-infected animals. In sum, our results indicate that ZIKV impairs angiogenesis in addition to neurogenesis during development. The vasculature defects represent a limitation for general brain growth but also could regulate neurogenesis directly.


Assuntos
Neovascularização Fisiológica , Infecção por Zika virus/congênito , Zika virus/fisiologia , Animais , Vasos Sanguíneos/patologia , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Encéfalo/virologia , Modelos Animais de Doenças , Embrião de Mamíferos/patologia , Embrião de Mamíferos/virologia , Células Endoteliais/patologia , Células Endoteliais/virologia , Feminino , Camundongos Endogâmicos C57BL , Neurogênese , Tamanho do Órgão , Infecção por Zika virus/patologia , Infecção por Zika virus/virologia
12.
Curr Pharm Des ; 24(20): 2311-2316, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30051776

RESUMO

BACKGROUND: Heme-oxygenase (HO) catalyzes the main enzymatic step of heme degradation and generates anti-inflammatory end products with protective roles in physiological and pathological situations. The importance of HO in pathological conditions is evidenced by its pharmacological inhibition or genetic blockage in different models of stress such as infection, inflammation and oxidative stress. Under these situations, another well-known protective process triggered is autophagy. Autophagy is a homeostatic process that eliminates defective cytosolic components and organelles, allowing cells and tissues to recover through recycling of functional blocks for anabolic reactions. Recently, studies have demonstrated a link between HO activity and autophagy activation. OBJECTIVE: In this review, we focus on the interplay between HO and autophagy, and highlight its importance in homeostasis maintenance under stress conditions.


Assuntos
Autofagia/fisiologia , Heme Oxigenase-1/metabolismo , Homeostase/fisiologia , Animais , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Estresse Fisiológico
13.
Cytopathology ; 29(4): 355-360, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29893438

RESUMO

INTRODUCTION: To evaluate the internal quality control indicators and quality management programme in a university cytopathology laboratory. METHODS: All results of conventional cervical smears tests (taken from the SISCAN, the Brazilian cervical cancer screening system) of women aged ≥15 years at the time of Papanicolaou smear specimen collection during January 2007-December 2014 were included. The final results of the cytopathology were classified in accordance with the Bethesda System. The variables included in the database were the woman's name, date of birth, and age at the time of sampling (15-30, 31-40 and older than 40 years). RESULTS: In this period, 50 286 cytopathology examinations were carried out. Of these, 44 386 (91.34%) were negative for malignancy or unsatisfactory and 4209 (8.66%) presented epithelial abnormalities. The percentage of the tests consistent with atypical squamous cells (ASC) between satisfactory examinations was 4.12%; the percentage of tests compatible with ASC among abnormal examinations was 47.87%; the ASC/squamous intraepithelial lesion) ratio was 0.97 and the percentage of high-grade squamous intraepithelial lesion among satisfactory tests was 2.21%, and the 5-year retrospective review identified 4.97% of false-negative results. CONCLUSION: All rates obtained were consistent over the years and within the recommended values by Federal Regulation of Brazil. This demonstrates the efficacy of our established internal quality monitoring and continuing education, reflecting the commitment of the team involved in the release of smear reports.


Assuntos
Colo do Útero/patologia , Teste de Papanicolaou/normas , Controle de Qualidade , Doenças do Colo do Útero/patologia , Adolescente , Adulto , Brasil , Serviços de Laboratório Clínico , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Universidades
14.
Morphologie ; 102(337): 78-82, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29625795

RESUMO

Venous punctures are among the most common procedures performed by healthcare professionals. In particular, the cubital fossa is the site where the venous accesses are frequently made due to the number of superficial veins and the numerous anastomoses in this region. The arrangement of these venous connections is of particular interest for clinical application in several areas, thus, the healthcare professional must possess knowledge about these vessels and their anatomical relationships. The present study aims to analyze the venous pattern of the cubital fossa among individuals from Brazil. This study was approved by a Research Ethics Committee. The sample had 100 healthy individuals (50 men and 50 women). The superficial veins of the cubital fossa were analyzed with the aid of a sphygmomanometer. When inflated, the pressure in the forearm increased and the veins became prominent. It was observed that in the selected sample the types with the highest prevalence were the Type I and Type VII, both with 22% in 200 limbs studied. The chi2 test showed a significant statistical difference between the anastomosis pattern and the sex of the studied sample. The anastomotic pattern of the superficial veins of the studies sample is similar to African, European and Asian populations. The study of these variations is necessary to provide scientific basis for the healthcare professional during a venipuncture in order to avoid iatrogenic errors and damages in cutaneous nerves or neighboring arteries.


Assuntos
Variação Anatômica , Cotovelo/irrigação sanguínea , Erros Médicos/prevenção & controle , Flebotomia/efeitos adversos , Veias/anatomia & histologia , Adolescente , Adulto , Artérias/anatomia & histologia , Brasil , Cotovelo/inervação , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Flebotomia/métodos , Fatores Sexuais , Pele/irrigação sanguínea , Pele/inervação , Esfigmomanômetros , Adulto Jovem
15.
Anaesthesia ; 73(3): 304-312, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29265174

RESUMO

Ultrasound examination of the gastric antrum is a non-invasive tool that allows reliable estimation of gastric contents. We performed this prospective cohort study in non-elective paediatric surgery to assess whether gastric ultrasound may help to determine the best anaesthetic induction technique, whether rapid sequence or routine. The primary outcome was the reduction of inappropriate induction technique. A pre-operative clinical assessment was performed by the attending anaesthetist who made a provisional plan for induction. Gastric ultrasound was performed in the semirecumbent and right lateral decubitus positions for a qualitative assessment of gastric contents, using a 0-2 grading scale. A final induction plan was made based on this assessment. Immediately after tracheal intubation, gastric contents were suctioned through a multi-orifice nasogastric tube; these were defined as above risk threshold for regurgitation and aspiration if there was clear fluid > 0.8 ml.kg-1 , and/or the presence of thick fluid and/or solid particles. Gastric ultrasound was feasible in 130 out of 143 (90%) of children, and led to a change in the planned induction technique in 67 patients: 30 from routine to rapid sequence, and 37 from rapid sequence to routine. An appropriate induction technique was therefore performed in 85% of children, vs. 49% planned after pre-operative clinical assessment alone (p < 0.00001). Our results suggest that gastric ultrasound is a useful guide to the general anaesthetic induction technique with respect to the risk of pulmonary aspiration, in comparison with pre-operative clinical assessment alone.


Assuntos
Anestesia Geral/métodos , Cuidados Pré-Operatórios , Antro Pilórico/diagnóstico por imagem , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Prospectivos
16.
Eur Arch Paediatr Dent ; 18(6): 399-404, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29075962

RESUMO

AIM: To evaluate the prevalence of sleep bruxism and associated factors among children aged 3-12 years as reported by parents via a questionnaire. METHODS: A cross-sectional study was conducted with a sample of 148 parents/caregivers of children aged 3-12 years treated at paediatric dentistry clinics. Parents/caregivers answered a questionnaire in the waiting room. Information on the gender and age of the child, age of parent/caregiver, meaning of bruxism and child's sleep (type of sleep, if he/she slept alone, hours of sleep per night and if nocturnal bruxism could affect his/her health) were collected. Descriptive statistics were performed and Poisson regression with robust variance was employed (p < 0.05). RESULTS: The prevalence of sleep bruxism was 32.4%. Most parents (64.2%) did not know the meaning of bruxism. In the final Poisson regression model, child's gender (PR 1.32; 95% CI 1.06-1.66) and restless sleep (PR 1.39; 95% CI 1.12-1.72) were significantly associated with sleep bruxism. CONCLUSION: The prevalence of sleep bruxism was high and was associated with gender and having restless sleep. Most parents/guardians did not know the meaning of bruxism.


Assuntos
Bruxismo do Sono/epidemiologia , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Masculino , Pais , Prevalência , Fatores Sexuais , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Inquéritos e Questionários
17.
Phys Chem Chem Phys ; 19(33): 22078-22087, 2017 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-28795183

RESUMO

In the present work we propose a novel treatment to investigate ballistic electron transport under mechanical strain in a 1-D molecular bridge composed of alternating simple and triple bonds (polyyne) connected between two Single-Wall Carbon Nanotube (SWCNT) electrodes. Calculations with the DFT-NEGF methodology were performed in order to analyze this system at low values of mechanical strain (compression and distension) and at equilibrium length in the presence of bias voltages applied along the longitudinal direction. The results show that, while the mechanical strain displaces the energy levels and changes the band gap in the nanotube caps, the applied bias breaks the degeneracy in the nanotube cap states and defines the electrical conductance along the system. The analysis of the PDOS suggests that the main contribution to the electrical current comes from the superposition of the nanotube cap states, which is in agreement with the transmission calculation, and this device can be employed as a transistor observed in the I-V curve.

18.
Anaesthesia ; 72(11): 1351-1356, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28805238

RESUMO

Ultrasound examination of the gastric antrum allows reliable assessment of gastric contents and volume. Postoperative assessment of gastric contents before recovery from anaesthesia could help the physician to choose the most appropriate extubation technique after surgery in children. In this prospective observational study, we assessed whether significant changes occurred in gastric contents during the intra-operative period in children undergoing elective ear, nose and throat (ENT) surgery. Children aged between six months and 16 years were recruited consecutively. Ultrasound examination of the antrum was performed before induction of anaesthesia and at the end of surgery before tracheal extubation, and included quantitative and qualitative assessment of gastric contents. The mean (SD) gastric volume was 0.28 (0.30) ml.kg-1 before surgery and 0.27 (0.30) ml.kg-1 after surgery, p = 0.82. No solid contents were identified in the antrum, and the gastric volume was < 1.5 ml.kg-1 in all patients during both ultrasound examinations. Our results suggest that, after elective ENT surgery, children are not at risk of a full stomach before tracheal extubation, and that pulmonary aspiration of blood that may occur after elective ENT surgery is probably not related to regurgitation of ingested blood from the stomach.


Assuntos
Procedimentos Cirúrgicos Eletivos/métodos , Conteúdo Gastrointestinal/diagnóstico por imagem , Procedimentos Cirúrgicos Otorrinolaringológicos/métodos , Estômago/diagnóstico por imagem , Ultrassonografia/métodos , Adolescente , Extubação , Criança , Pré-Escolar , Estudos de Coortes , Jejum , Feminino , Humanos , Lactente , Masculino , Pneumonia Aspirativa/etiologia , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Antro Pilórico/diagnóstico por imagem
20.
Braz. j. biol ; 77(1): 162-169, Jan-Mar. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-839156

RESUMO

Abstract Predatory mites that belong to the Phytoseiidae family are one of the main natural enemies of phytophagous mites, thus allowing for their use as a biological control. Phytoseiulus macropilis (Banks, 1904) (Acari: Phytoseiidae) is among the main species of predatory mites used for this purpose. Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) is considered to be one of the most important species of mite pests and has been described as attacking over 1,100 species of plants in 140 families with economic value. The objective of the present study was to investigate, in the laboratory, the reproductive parameters of the predatory mite P. macropilis when fed T. urticae. Experiments were conducted under laboratory conditions at 25 ± 2 °C of temperature, 70 ± 10% RH and 14 hours of photophase. In addition, biological aspects were evaluated and a fertility life table was established. The results of these experiments demonstrated that the longevity of adult female was 27.5 days and adult male was 29.0 days. The population was estimated to increase approximately 27 times (Ro) in mean generation time (T), which was 17.7 days. Lastly, the mite population grew 1.2 times/day (λ) and doubled every 3.7 days (TD).


Resumo Os ácaros predadores pertencentes à família Phytoseiidae constituem um dos principais inimigos naturais de ácaros fitófagos, o que possibilita o seu uso em controle biológico. Entre as principais espécies destaca-se Phytoseiulus macropilis (Banks, 1904) (Acari: Phytoseiidae). O ácaro Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) é considerado uma das espécies de ácaros-praga mais importantes, atacando mais de 1.100 espécies de plantas em 140 famílias de valor econômico. Este trabalho foi realizado com o objetivo de estudar, em laboratório, os parâmetros reprodutivos do ácaro predador P. macropilis, quando alimentado com T. urticae. Os estudos foram conduzidos em laboratório à temperatura de 25 ± 2 °C, 70 ± 10% de UR e 14 horas de fotofase e foram avaliados os aspectos biológicos e confeccionada a tabela de vida de fertilidade. Foi constatada uma longevidade de 27,5 dias para fêmeas adultas e 29,0 dias para machos. A população foi estimada em aumentar aproximadamente 27 vezes (Ro) no período médio de duração de geração (T) que foi de 17,7 dias. A população do ácaro cresceu 1,2vezes/dia (λ) e dobrou a cada 3,7 dias (TD).


Assuntos
Animais , Masculino , Feminino , Reprodução , Tetranychidae , Longevidade , Ácaros/fisiologia
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