16 research outputs found
Transcranial Magnetic Stimulation to Address Mild Cognitive Impairment in the Elderly: A Randomized Controlled Study
Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique with potential to improve memory. Mild cognitive impairment (MCI), which still lacks a specific therapy, is a clinical syndrome associated with increased risk of dementia. This study aims to assess the effects of high-frequency repetitive TMS (HF rTMS) on everyday memory of the elderly with MCI. We conducted a double-blinded randomized sham-controlled trial using rTMS over the left dorsolateral prefrontal cortex (DLPFC). Thirty-four elderly outpatients meeting Petersenâs MCI criteria were randomly assigned to receive 10 sessions of either active TMS or sham, 10âHz rTMS at 110% of motor threshold, 2,000 pulses per session. Neuropsychological assessment at baseline, after the last session (10th) and at one-month follow-up, was applied. ANOVA on the primary efficacy measure, the Rivermead Behavioural Memory Test, revealed a significant group-by-time interaction p=0.05, favoring the active group. The improvement was kept after one month. Other neuropsychological tests were heterogeneous. rTMS at 10âHz enhanced everyday memory in elderly with MCI after 10 sessions. These findings suggest that rTMS might be effective as a therapy for MCI and probably a tool to delay deterioration
Fatigue Life Prediction of Steel Pipelines Based on X-ray Diffraction Analyses
International audienc
High Cycle Fatigue Damage Evaluation of Steel Pipelines Based on Microhardness Changes During Cyclic Loads: Part II
ACTIInternational audienceThe hardness of a material shows its ability to resist to microplastic deformation caused by indentation or penetration and is closely related to the plastic slip capacity of the material. Therefore, it could be significant to study the resistance to microplastic deformations based on microhardness changes on the surface, and the associated accumulation of fatigue damage. The present work is part of a research study being carried out with the aim of proposing a new method based on microstructural changes, represented by a fatigue damage indicator, to predict fatigue life of steel structures submitted to cyclic loads, before macroscopic cracking. Here, Berkovich indentation tests were carried out in the samples previously submitted to high cycle fatigue (HCF) tests. It was observed that the major changes in the microhardness values occurred at the surface of the material below 3 ÎŒm of indentation depth, and around 20% of the fatigue life of the material, proving that microcracking is a surface phenomenon. So, the results obtained for the surface of the specimen and at the beginning of the fatigue life of the material will be considered in the proposal of a new method to estimate the fatigue life of metal structures
Diagnostic Imaging of Diseases Affecting the Guttural Pouch
The most common diseases of the guttural pouch are empyema, tympany, mycosis and temporohyoid osteoarthropathy. The challenge in diagnosis of guttural pouch diseases lies in the complex anatomy of the guttural pouch and adjacent associated structures. Diagnostic imaging is a good complement to endoscopy for the diagnosis of some guttural pouch diseases, especially to make a full assessment of the lesions involving the pouch and surrounding structures. This review article describes the value of each diagnostic imaging technique in the diagnosis of guttural pouch disease and the corresponding imaging findings. Radiography is generally used as the first line to complement endoscopic findings, and can give useful additional information although it is limited by superimposition. Ultrasonographic examination of the guttural pouch is of limited value due to the presence of gas in the guttural pouch but can eventually be used to detect fluid within the pouch or can help to evaluate the soft tissues located lateral and ventral to the guttural pouch. Cross-sectional imaging, especially CT, is increasingly available and appears to be the best technique to fully assess the surrounding soft tissues and to precisely identify lesions of the temporohyoid apparatus, temporal bone and skull base that are associated with guttural pouch disease
High Cycle Fatigue Damage Evaluation of Steel Pipelines Based on Microhardness Changes During Cyclic Loads
International audienceFatigue is a major cause of failures concerning metal structures, being capable of causing catastrophic damage to the environment and considerable financial loss. Steel pipelines used in oil and gas industry for hydrocarbon transportation, for instance, are submitted to the action of cyclic loads, being susceptible to undergo fatigue failures. The phenomenon of metal fatigue is a complex process comprising different successive mechanisms. In general, four stages can be identified, representing microcrack initiation (nucleation), microcracking, macrocrack propagation, and final fracture. Fatigue damage prior to nucleation of microcracks is primarily related to localized plastic strain development at or near material surface during cycling. The microhardness of the material shows its ability to resist microplastic deformation caused by indentation or penetration, and is closely related to the material plastic slip capacity. Therefore, the study of changes in material surface microhardness during the different stages of fatigue process can estimate the evolution of the material resistance to microplastic deformations and, consequently, provide relevant information about the cumulated fatigue damage on the surface. The present work is part of a research study being carried out with the aim of proposing a new method based on microstructural changes, represented by a fatigue damage indicator, to predict fatigue life of steel structures submitted to cyclic loads, before macroscopic cracking. In a previous work, the X-ray diffraction technique was used to evaluate these changes. This technique presents several advantages, since it is non-destructive and concerns the surface and subsurface of the material, where major microstructural changes take place during fatigue. The most important parameter obtained by this technique is the full width at half maximum (FWHM) of the diffraction peak, which can provide information about the dislocation network density and estimate microdeformations. It was found that the evolution of this parameter with cycling presents three different stages, associated to the mechanisms of microcrack initiation, microcracking, macrocrack propagation, respectively. Here, the fatigue damage of pipeline steels is evaluated through microhardness testing. Different stages of changes in microhardness are also found and they are correlated to those observed with the X-ray technique and also with transmission electron microscopic (TEM) images from experimental tests performed with a similar material. This correlation can help to corroborate the X-ray diffraction results previously obtained and recommend then this non-destructive technique as the base of the method for predicting fatigue life of steel structures proposed here
CONCENTRAĂĂES SĂRICAS DE SĂDIO, POTĂSSIO E CĂLCIO EM EQUINOS DA RAĂA MANGALARGA MARCHADOR APĂS EXERCĂCIO FĂSICO
O presente estudo teve por objetivo avaliar a influĂȘncia do exercĂcio fĂsico de intensidade submĂĄxima (marcha) sobre as concentraçÔes sĂ©ricas de sĂłdio, potĂĄssio e cĂĄlcio em equinos criados no estado do EspĂrito Santo. Foram obtidas amostras de sangue de 15 equinos, da raça Mangalarga Marchador, em quatro momentos: antes (T0), com 5 minutos (T1), 30 minutos (T2) e 2 horas (T3) apĂłs o termino da atividade fĂsica (40 minutos de marcha). Os valores mĂ©dios para o sĂłdio foram de 148,1±18,2mEq/L, 151,1±12,7mEq/L, 144,1±17,4mEq/L e 152,3±23,1mEq/L; para o potĂĄssio foram de 4,2±0,8mEq/L, 4,7±0,7mEq/L, 3,4±0,5mEq/L e 3,9±0,8mEq/L; e para o cĂĄlcio foram de 11,1±1,8mg/dL, 10,6±1,6mg/dL, 11,5±2,6mg/dL e 11,0±1,5mg/dL, respectivamente, nos tempos T0, T1, T2 e T3. Os resultados demonstraram que a marcha nĂŁo influenciou de forma significativa os valores sĂ©ricos de sĂłdio e de cĂĄlcio. Houve diferença significativa com redução nos valores mĂ©dios de potĂĄssio em T2 (p<0,0001). Os resultados tambĂ©m sugerem que os equinos estavam bem condicionados ao tipo de exercĂcio fĂsico imposto
Efficiency of OPU-IVEP-ET of fresh and vitrified embryos in buffaloes.
The present study aims to report ovum pickup (OPU), in vitro embryo production (IVEP) and embryo transfer (ET) outcomes of fresh and vitrified buffalo embryos. For this purpose, 36 buffalo donors were submitted to 11 OPU sessions (n = 201). A total of 998 oocytes (5.0 +/- 0.5/donor/session) and 584 viable oocytes (2.9 +/- 0.3/donor/session) were recovered. Viable oocytes (grades 1, 2 and 3) were subjected to IVM, IVF (D0) and IVC. On D2, 54.5% of cleavage rate was obtained. Embryo yield on D7 was 44.9% (grade 1: 229 embryos, grade 2: 5 embryos and grade 3: 28 embryos). From this total, 115 fresh (grades 1 to 3) and 70 vitrified embryos (only grade 1) were transferred into recipients previously synchronized with fixed time embryo transfer (FTET) protocol. Vitrification was performed using the cryotop method. Pregnancy diagnosis in fresh and in vitrified groups were, respectively: 43.5% (50/115) and 37.1% (26/70) on 30 days after embryo transfer, and 41.7% (48/115) and 31.4% (22/70) on 60 days after embryo transfer. In conclusion, our results demonstrate the possibilities for commercial use of the techniques of OPU, IVEP and ET of fresh and vitrified embryos in buffaloes
Pregnancy monitoring of in vitro produced embryos in buffaloes
In the present study, pregnancies obtained from 115 in vitro produced embryos were monitored by ultrasonography on days 30 and 60 after embryo transfer (ET), and at calving. Additionally, the health of newborns and recipients were also evaluated. On day 30 after ET, positive pregnancy was diagnosed in 50 animals (43.5%). A total of 8 fetal mortalities (16.0%) were verified from 30 days until calving, in which 2 occurred from 30 to 60 days after ET (4.0%), and 6 occurred from 60 days until calving (12.0%). In this last period of pregnancy, 3 pregnancy losses were due to abortion, and the other 3 were stillbirth. One additional animal was eliminated from the study, remaining 41 pregnancies. From these 41 pregnancies, a total of 20 female calves (48.8%) and 21 male calves (51.2%) were born. Pregnancies from female and male calves had a mean length of 309.8 and 310.9 days, respectively (range 300 to 328 days, and 297 to 320 days, respectively). Weight at calving was a mean of 31.4 and 33.8 kg for female and male calves, respectively. All calving occurred without intervention and dystocia was not observed in any case. No large offspring syndrome, hydramnios, hydroallantois, or umbilical cord anomalies were observed in calves. Delivery was normal in all recipients, and no puerperal infections, or retained placenta occurred. Suckling assistance was not necessary in any newborn. All genetic pedigree was confirmed later by DNA tests
Pregnancy Monitoring of In Vitro Produced Embryos in Buffaloes
In the present study, pregnancies obtained from 115 in vitro produced embryos were monitored by ultrasonography on days 30 and 60 after embryo transfer (ET), and at calving. Additionally, the health of newborns and recipients were also evaluated. On day 30 after ET, positive pregnancy was diagnosed in 50 animals (43.5%). A total of 8 fetal mortalities (16.0%) were verified from 30 days until calving, in which 2 occurred from 30 to 60 days after ET (4.0%), and 6 occurred from 60 days until calving (12.0%). In this last period of pregnancy, 3 pregnancy losses were due to abortion, and the other 3 were stillbirth. One additional animal was eliminated from the study, remaining 41 pregnancies. From these 41 pregnancies, a total of 20 female calves (48.8%) and 21 male calves (51.2%) were born. Pregnancies from female and male calves had a mean length of 309.8 and 310.9 days, respectively (range 300 to 328 days, and 297 to 320 days, respectively). Weight at calving was a mean of 31.4 and 33.8 kg for female and male calves, respectively. All calving occurred without intervention and dystocia was not observed in any case. No large offspring syndrome, hydramnios, hydroallantois, or umbilical cord anomalies were observed in calves. Delivery was normal in all recipients, and no puerperal infections, or retained placenta occurred. Suckling assistance was not necessary in any newborn. All genetic pedigree was confirmed later by DNA tests