230 research outputs found
Modeling of coastal water contamination in Fortaleza (Northeastern Brazil)
An important tool in environmental management projects and studies due to the complexity of environmental systems, environmental modeling makes it possible to integrate many variables and processes, thereby providing a dynamic view of systems. In this study the bacteriological quality of the coastal waters of Fortaleza (Brazil) was modeled considering multiple contamination sources. Using the software SisBaHiA, the dispersion of thermotolerant coliforms and Escherichia coli from three sources of contamination (rivers, storm drains and submarine outfall) was analyzed. The models took into account variations in bacterial decay due to solar radiation and other environmental factors. Fecal pollution discharged from rivers and storm drains is transported westward by coastal currents, contaminating strips of beach water to the left of each storm drain or river. Exception to this condition only occurs on beaches protected by the breakwater of the harbor, where counterclockwise vortexes reverse this behavior. The results of the models were consistent with field measurements taken during the dry and the rainy season. Our results show that the submarine outfall plume
was over 2 km from the nearest beach. The storm drains and the Maceió stream are the main factors responsible for the poor water quality on the waterfront of Fortaleza
Early psychiatric morbidity in a Brazilian sample of acute ischemic stroke patients
OBJECTIVE: Stroke is a major public health problem worldwide, and its neuropsychiatric sequelae are frequent and disabling. Furthermore, there is evidence that these sequelae impair recovery. Brazil has the highest stroke rates in Latin America, but data on the frequency of neuropsychiatric disorders in these patients are scarce. This study aimed to identify mental disorders among in-hospital patients with acute ischemic stroke. METHODS: The Mini International Neuropsychiatric Interview-Plus (MINI-Plus) was applied to 60 patients during the first week of hospitalization. RESULTS: Psychiatric disorders were diagnosed in 55% of the patients. A wide range of neuropsychiatric disorders have been identified, mainly mood and anxiety disorders. Specifically, we identified major depression (26.7%), alcohol abuse or dependence (11.7%), specific phobia (8.3%), generalized anxiety disorder (6.7%), psychosis (5.0%), social phobia (3.3%), adjustment disorder (3.3%) and panic disorder (1.7%). CONCLUSION: Psychiatric comorbidity should be evaluated as part of the rehabilitation of stroke patients and should be carefully examined by physicians
Low temperature thermal diffusivity of LiKSO4 obtained using the photoacoustic phase lag method
This paper describes the determination of the thermal diffusivity of LiKSO4 crystals using the photoacoustic phase lag method, in the 77 K to 300 K temperature interval. This method is quite simple and fast and when it is coupled to a specially designed apparatus, that includes a resonant photoacoustic cell, allows for the determination of the thermal diffusivity at low temperatures. The thermal diffusivity is an important parameter that depends on the temperature, and no values of this parameter for LiKSO4, at low temperature, have yet been reported. The LiKSO4 is a crystal with many phase transitions which can be detected via the anomalies in the variation of the thermal diffusivity as a function of the temperature
Peripheral nerve injury and axonotmesis: State of the art and recent advances
Peripheral nerve lesions are frequent occurrences in both human and animal patients, leading to important physiological and labor complications that affect the quality of life of those who suffer the injury. More severe injuries are often associated with poor nerve regeneration and inadequate functional recovery, even with early medical and surgical interventions. Peripheral nerve crush lesions are frequent and, therefore, an experimental lesion paradigm widely used in researches involving nerve injury models and therapies for its resolution. In recent years, many studies have focused on innovative approaches to peripheral nerve treatment after crush injuries with more or less success. This review addresses the theme of peripheral nerve injury, with a special focus on the axonotmesis lesion, its etiology, pathophysiological mechanisms, methods of functional evaluation and regenerative processes, therapeutic options and corresponding recent advances
Cardiopulmonary exercise test in patients with refractory angina: functional and ischemic evaluation
Objectives: Refractory angina (RA) is a chronic condition clinically characterized by low effort tolerance; therefore, physical stress testing is not usually requested for these patients. Cardiopulmonary exercise testing (CPET) is considered a gold standard examination for functional capacity evaluation, even in submaximal tests, and it has gained great prominence in detecting ischemia. The authors aimed to determine cardiorespiratory capacity by using the oxygen consumption efficiency slope (OUES) in patients with refractory angina. The authors also studied the O2 pulse response by CPET and the association of ischemic changes with contractile modifications by exercise stress echocardiography (ESE).
Methods: Thirty-one patients of both sexes, aged 45 to 75 years, with symptomatic (Canadian Cardiovascular Society class II to IV) angina who underwent CPET on a treadmill and exercise stress echocardiography on a lower limb cycle ergometer were studied. ClinicalTrials.gov: NCT03218891.
Results: The patients had low cardiorespiratory capacity (OUES of 1.74 ± 0.4 L/min; 63.9±14.7% of predicted), and 77% of patients had a flattening or drop in O2 pulse response. There was a direct association between Heart Rate (HR) at the onset of myocardial ischemia detected by ESE and HR at the onset of flattening or drop in oxygen pulse response detected by CPET (R = 0.48; p = 0.019).
Conclusion: Patients with refractory angina demonstrate low cardiorespiratory capacity. CPET shows good sensitivity for detecting abnormal cardiovascular response in these patients with a significant relationship between flattening O2 pulse response during CEPT and contractile alterations detected by exercise stress echocardiography
Clinical presentation, histological findings, and prognosis in female dogs with mixed mammary neoplasms
ABSTRACT The aim of this study was to describe the clinical and morphological characteristics of mixed mammary neoplasms and verify what characteristics affect the prognosis of female dogs with carcinomas in mixed tumors and carcinosarcomas. This was a retrospective study of 67 female dogs that underwent mastectomies and were diagnosed with benign mixed tumors (n=13), carcinomas in mixed tumors (n=44) and carcinosarcomas (n=10). Data regarding the clinical and histological aspects of the neoplasms were collected and the relation with specific survival times, and hazard ratios (HR) in 24 months was calculated. In univariate analysis, the diagnosis of carcinosarcoma (HR 8.26, p=0.006), carcinomatous areas with micropapillary or solid patterns (HR 17.49; p=0. 001) and lymph node metastasis (HR 7.07;p=0.020) were associated with specific survival. In multivariable analysis, only micropapillary or solid pattern (HR=16.34; p=0.007) remained independent factor associated with lower specific survival. Micropapillary or solid carcinomatous patterns were associated with shorter specific survival time (p=0.002) among animals with carcinomas in mixed tumors. Among the carcinosarcomas, lymph node metastasis (p=0.010) was associated with a shorter specific survival time. In conclusion, carcinomas in mixed tumors and carcinosarcomas vary in prognosis depending on the carcinomatous proliferation patterns and spread of the disease
Genetic control of common bean (Phaseolus vulgaris) resistance to powdery mildew (Erysiphe polygoni)
Mechanical properties of murine hippocampal subregions investigated by atomic force microscopy and in vivo magnetic resonance elastography
The hippocampus is a very heterogeneous brain structure with different mechanical properties reflecting its functional variety. In particular, adult neurogenesis in rodent hippocampus has been associated with specific viscoelastic properties in vivo and ex vivo. Here, we study the microscopic mechanical properties of hippocampal subregions using ex vivo atomic force microscopy (AFM) in correlation with the expression of GFP in presence of the nestin promoter, providing a marker of neurogenic activity. We further use magnetic resonance elastography (MRE) to investigate whether in vivo mechanical properties reveal similar spatial patterns, however, on a much coarser scale. AFM showed that tissue stiffness increases with increasing distance from the subgranular zone (p = 0.0069), and that stiffness is 39% lower in GFP than non-GFP regions (p = 0.0004). Consistently, MRE showed that dentate gyrus is, on average, softer than Ammon's horn (shear wave speed = 3.2 ± 0.2 m/s versus 4.4 ± 0.3 m/s, p = 0.01) with another 3.4% decrease towards the subgranular zone (p = 0.0001). The marked reduction in stiffness measured by AFM in areas of high neurogenic activity is consistent with softer MRE values, indicating the sensitivity of macroscopic mechanical properties in vivo to micromechanical structures as formed by the neurogenic niche of the hippocampus
Use of chitosan scaffolds for repairing rat sciatic nerve defects
Neurotmesis must be surgically treated by direct end-to-end suture of the two nerve stumps or by a nerve graft harvested from elsewhere in the body in case of tissue loss. To avoid secondary damage due to harvesting of the nerve graft, a tube-guide can be used to bridge the nerve gap. Previously, our group developed and tested hybrid chitosan membranes for peripheral nerve tubulization and showed that freeze-dried chitosan type III membranes were particularly effective for improving peripheral nerve functional recovery after axonotmesis. Chitosan type III membranes have about 110 µm pores and about 90% of porosity, due to the employment of freeze-drying technique. The present study aimed to verify if chitosan type III membranes can be successfully used also for improving peripheral nerve functional recovery after neurotmesis of the rat sciatic nerve. Sasco Sprague-Dawley adult rats were divided into 6 groups: Group 1: end-to-end neurorrhaphy enwrapped by chitosan membrane type III (End-to-EndChitIII); Group 2: 10mm-nerve gap bridged by an autologous nerve graft enwrapped by chitosan membrane type III (Graft180ºChitIII); Group 3: 10mm-nerve gap bridged by chitosan type III tube-guides (GapChitIII); These 3 experimental groups were compared with 3 control groups, respectively: Group 4: 10mm-nerve gap bridged by an autologous nerve graft (Graft180º); Group 5: 10mm-nerve gap bridged by PLGA 90:10 tube-guides (PLGA); Group 6: end-to-end neurorrhaphy alone (End-to-End). Motor and sensory functional recovery were evaluated throughout a healing period of 20 weeks using extensor postural thrust (EPT), withdrawal reflex latency (WRL) and ankle kinematics. Regenerated nerves withdrawn at the end of the experiment were analysed histologically. Results showed that nerve regeneration was successful in all experimental and control groups and that chitosan type III tubulization induced a significantly better nerve regeneration and functional recovery in comparison to PLGA tubulization control. Further investigation is needed to explore the mechanisms at the basis of the positive effects of chitosan type III on axonal regeneration
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