Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
1.
J Mech Behav Biomed Mater ; 142: 105812, 2023 06.
Article in English | MEDLINE | ID: mdl-37084491

ABSTRACT

This study set out to develop a thermally compatible glass to be infiltrated into zirconia partially stabilized by yttrium oxide (5Y-PSZ), to characterize it, and to evaluate its structural reliability and mechanical behavior. 5Y-PSZ zirconia discs (N = 90), dimensions 1.5 mm × 15 mm were produced, polished with #600 alumina oxide and #1200 silicon carbide sandpaper in a polisher. Three groups of 5Y-PSZ discs were assigned (n = 30): Zctrl: as sintered zirconia, Zinf-comp: glass-infiltrated zirconia on the occlusal surface, and sintered, and Zinf-tens: glass-infiltrated zirconia on the cementing surface and sintered; for biaxial flexural strength testing (ISO 6872:2015). A gel was synthesized via the sol-gel method and applied to the ceramic surface. Mechanical assay data (MPa) were evaluated via Weibull analysis (α = 5%) and specimens via X-Ray Diffractometry (XRD), Scanning Electron Microscopy (SEM), and fractographic analysis. The Zinf-tens group showed a characteristic strength of 824 MPa and m = 9.9; Zinf-comp 613 MPa and m = 10.2; Zctrl 534 MPa and m = 8; all groups differed statistically (σ0). However, they were similar in structural homogeneity (m). XRD showed 20-50 µm of infiltration, which means dissolution of part of the yttrium and reduction in the size of the cubic grains. In addition, the Zinf-tens group presented a failure origin from inside the material. The developed glass infiltrated into zirconia partially stabilized by yttrium oxide, increasing its characteristic strength and structural homogeneity by reducing surface defects and changing the failure mode.


Subject(s)
Flexural Strength , Zirconium , Materials Testing , Reproducibility of Results , Zirconium/chemistry , Yttrium/chemistry , Ceramics/chemistry , Surface Properties , Dental Materials
2.
J Econ Entomol ; 110(4): 1770-1778, 2017 08 01.
Article in English | MEDLINE | ID: mdl-28535300

ABSTRACT

Bacillus thuringiensis (Bt) corn producing the Cry1F protein was the first highly efficacious Bt corn deployed against the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Brazil, but reduced efficacy of this technology against the fall armyworm has been reported in some regions of the country. Here, we surveyed Cry1F resistance allele frequency and susceptibility of eight S. frugiperda populations collected in 2013 from non-Bt fields in different regions of Brazil. In F1 screen experiments, the overall frequency of the Cry1F resistance alleles in Brazilian populations was estimated at 0.24, with 95% credibility interval between 0.18 and 0.25. In concentration-response bioassays, five of the eight populations surveyed exhibited significant resistance levels, which were over 32 times higher than that of the standard susceptible laboratory strain. The estimates of Cry1F resistance allele frequency were positively correlated with those of median effective or lethal concentrations (i.e., EC50 or LC50). These results show that the allelic frequency and the magnitude of Cry1F resistance are high in field populations of S. frugiperda in Brazil, indicating a challenging situation for resistance management.


Subject(s)
Bacterial Proteins/pharmacology , Gene Frequency , Insecticide Resistance , Spodoptera/genetics , Animals , Bacillus thuringiensis/chemistry , Brazil , Plants, Genetically Modified/chemistry , Spodoptera/drug effects , Zea mays/chemistry
3.
Transplant Proc ; 42(2): 454-6, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20304163

ABSTRACT

To study if the treatment with adenosine (ADO), an agonist of adenosine receptors, attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), we treated rabbits with ADO (15 mg x kg(-1), intravenously) or saline solution (SS) to I (60 minutes) before occlusion of superior mesenteric artery and/or R (120 min). After I or I/R, isolated jejunal segments (2 cm) were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared to the sham group, the jejunal contractions were similar in I + ADO, but reduced in I + SS, I/R + SS, and I/R + ADO groups. We concluded that the jejunal enteric nerves were damaged in I + SS, I/R + SS, and I/R + ADO, but not in I + ADO group. These results suggested that ADO attenuated intestinal dysfunction due to I, but not to R.


Subject(s)
Adenosine/pharmacology , Intestines/blood supply , Reperfusion Injury/drug therapy , Animals , Blood Circulation , Electric Stimulation , Femoral Vein/drug effects , Femoral Vein/physiology , Jejunum/blood supply , Jejunum/drug effects , Jejunum/physiology , Male , Mesenteric Artery, Superior/physiology , Muscle Contraction/drug effects , Muscle Contraction/physiology , Potassium Chloride/pharmacology , Purinergic P1 Receptor Agonists , Rabbits , Sodium Chloride/pharmacology
5.
J Pediatr (Rio J) ; 70(1): 33-8, 1994.
Article in Portuguese | MEDLINE | ID: mdl-14688892

ABSTRACT

The present article describes the management of three neonates with tricuspid atresia and duct dependent pulmonary circulation referred to the Instituto de Coração de Pernambuco in November 1992. A brief literature review of the condition is added. Full diagnosis was established with echocardiography at the neonatal ICU; all of them were intubated, mechanically ventilated and started on PGE1 and Dopamine infusions. Within 10h to 24h of hospitalization, all were submitted to surgery. One patient died on the third postoperative day the other two were discharged in good clinical condition. Despite the small our experience shows that clinical and surgical management of tricuspid atresia with duct dependent pulmonary circulation can reach satisfactory results in our region providing that early diagnosis of cyanotic heart disease is established by the pediatrician with timely transferal of the neonate to a reference center in paediatric cardiology.

6.
Arq Bras Cardiol ; 59(1): 47-9, 1992 Jul.
Article in Portuguese | MEDLINE | ID: mdl-1341146

ABSTRACT

PURPOSE: To describe the initial experience of a heart transplant program in Recife, Pernambuco. METHODS: Six patients in the final stage of heart failure were submitted to heart transplant. There were 4 male and 2 female patients, ranging in age from 15 to 61 years (mean, 43.8). Four had coronary heart disease and two dilated cardiomyopathy. The conventional operative technique of orthotopic heart transplant was used. All patients received a triple drug immunosuppressive therapy. RESULTS: There was one death due to acute rejection on the 28th postoperative day. The 5 survivors are in functional class I in a mean follow-up period of 113 days. CONCLUSION: The initial experience of a heart transplant program in Recife, Pernambuco, suggests that good long term results could be expected.


Subject(s)
Cardiac Care Facilities , Heart Transplantation , Adolescent , Adult , Brazil/epidemiology , Cardiac Care Facilities/statistics & numerical data , Female , Graft Rejection/epidemiology , Heart Transplantation/adverse effects , Heart Transplantation/statistics & numerical data , Humans , Male , Middle Aged , Postoperative Complications/epidemiology
7.
Arq Bras Cardiol ; 58(5): 375-7, 1992 May.
Article in Portuguese | MEDLINE | ID: mdl-1340711

ABSTRACT

Four children, three males, with ages 5, 1, 16 and 6 years, presented with isolated tricuspid valve endocarditis. Two of them were submitted to surgical treatment. Sepsis, cardiac murmur and heart failure were present in all of them. Three presented pulmonary embolism. Echocardiography demonstrated vegetation in the tricuspid valve in all cases. Two patients, one of them submitted to surgery, died. Tricuspid valve endocarditis in children with sepsis, heart failure and pulmonary embolism is a severe condition and early surgical treatment may diminished the high mortality.


Subject(s)
Endocarditis, Bacterial/diagnosis , Tricuspid Valve , Adolescent , Child , Child, Preschool , Echocardiography , Endocarditis, Bacterial/surgery , Female , Heart Valve Diseases/diagnosis , Heart Valve Diseases/surgery , Humans , Infant , Male
8.
ABCD (São Paulo, Impr.) ; 6(1): 15-9, jan.-mar. 1991. ilus
Article in English | LILACS | ID: lil-140067

ABSTRACT

Como etapa inicial de um plano de pesquisa sobre avaliacao de medidas descompressivas portosistemicas, comumente utilizadas em transplante hepatico experimental, foram estudados 20 caes mesticos, adultos, de ambos os sexos e com peso corporal de 15,2ñ1,7kg. Em dez caes praticou-se oclusao total e aguda da veia porta por um periodo de 2 horas (grupo oclusao portal). Em dez outros desses animais procedeu-se a operacao simulada (grupo controle). Foram investigados de modo sistematico dados hemodinamicos de pressao arterial (PA), pressao venosa central (PVC) e pressao portal (PP), assim como dados hematologicos de concentracao de hemoglobina (cHb) nos animais dos grupos estudados...


Subject(s)
Animals , Dogs , Portal Vein/surgery , Liver Transplantation , Research , Hemodynamics
9.
Arq Bras Cardiol ; 53(3): 161-3, 1989 Sep.
Article in Portuguese | MEDLINE | ID: mdl-2629672

ABSTRACT

To study the effects of age on the results of coronary artery bypass grafting (CABG), 250 patients operated on from 1986 to 1989 were divided into two groups: 1) less than 65 years of age and 2) older than 65. Pre, intra and postoperative data collected in all patients included: sex, type and class of angina, associated diseases, previous myocardial infarction, previous CABG, left ventricular aneurysm, bypass time, aortic cross-clamp time, number of grafts per patient, need for prolonged inotropic support, postoperative complications, and mortality. A large number of elderly patients had unstable angina (20.3% vs 6.2%), post-infarction angina (10.1% vs 7.8%), angina at rest (10.1% vs 3.6%), peripheral vascular disease (8.4% vs 2.6%), required prolonged inotropic support (18.6% vs 3.1%), had major neurological complications (8.4% vs 0.1%) and perioperative myocardial infarction (5.0% vs 0.5%). Overall mortality was 3.6% but mortality rates were significantly higher in elderly patients (11.8% vs 1.0%). These data suggest that elderly patients have an increased risk of cardiac and neurologic morbidity and mortality. It appear that the increased morbidity and mortality is related to an increased susceptibility of the elderly to serious postoperative complications.


Subject(s)
Myocardial Revascularization/mortality , Adult , Age Factors , Aged , Angina Pectoris/etiology , Angina, Unstable/etiology , Female , Humans , Male , Middle Aged , Myocardial Revascularization/adverse effects , Risk Factors
14.
J Thorac Cardiovasc Surg ; 89(6): 942-3, 1985 Jun.
Article in English | MEDLINE | ID: mdl-3999792

ABSTRACT

This report describes the case of a 19-month-old boy in whom paraplegia developed spontaneously 2 days after a technically uncomplicated coarctation of the aorta repair.


Subject(s)
Aortic Coarctation/surgery , Paraplegia/etiology , Humans , Infant , Male , Postoperative Complications/etiology , Time Factors
16.
Arq. bras. cardiol ; 42(4): 285-287, 1984. ilus, tab
Article in Portuguese | LILACS | ID: lil-21237

ABSTRACT

Os autores descrevem o cado de uma jovem de 27 anos de idade, portadora de aortite luetica e estenose do ostio da arteria coronaria esquerda. A paciente desenvolveu grave quadro de angina do peito sendo submetida, com sucesso, a cirurgia de revascularizacao miocardica. Chamam a atencao para a raridade e o grave prognostico dessa lesao, bem como para possibilidade de tratamento eficaz pelas pontes de veia safena


Subject(s)
Humans , Female , Adult , Angina Pectoris , Myocardial Revascularization , Syphilis, Cardiovascular
17.
Tex Heart Inst J ; 10(2): 115-8, 1983 Jun.
Article in English | MEDLINE | ID: mdl-15227123

ABSTRACT

The surgical technique of endocardiectomy and valve replacement for patients with uni- or biventricular endomyocardial fibrosis is described. Technical details of the operation are outlined, based upon experience with 37 surgical cases.

18.
J Cardiovasc Surg (Torino) ; 24(3): 256-8, 1983.
Article in English | MEDLINE | ID: mdl-6863384

ABSTRACT

A 2-year-old boy who presented with unrelated recurrent respiratory infections was found to have an enlarged cardiac silhouette on his chest roentgenogram. Clinical evaluation, echocardiography and cardiac cineangiograms failed to provide an accurate diagnosis. A left ventricular tumor was identified by exploratory thoracotomy and successful excision of an intramural fibroma of the left ventricle subsequently accomplished.


Subject(s)
Fibroma/surgery , Heart Neoplasms/surgery , Heart Ventricles/surgery , Child, Preschool , Fibroma/pathology , Heart Neoplasms/pathology , Humans , Male
SELECTION OF CITATIONS
SEARCH DETAIL
...