Carbon Nanofibers Grown in CaO for Self-Sensing in Mortar.

Intelligent cementitious materials integrated with carbon nanofibers (CNFs) have the potential to be used as sensors in structural health monitoring (SHM). The difficulty in dispersing CNFs in cement-based matrices, however, limits the sensitivity to deformation (gauge factor) and strength. Here, we synthesise CNF by chemical vapour deposition on the surface of calcium oxide (CaO) and, for the first time, investigate this amphiphilic carbon nanomaterial for self-sensing in mortar. SEM, TEM, TGA, Raman and VSM were used to characterise the produced CNF@CaO. In addition, the electrical resistivity of the mortar, containing different concentrations of CNF with and without CaO, was measured using the four-point probe method. Furthermore, the piezoresistive response of the composite was quantified by means of compressive loading. The synthesised CNF was 5-10 µm long with an average diameter of ~160 nm, containing magnetic nanoparticles inside. Thermal decomposition of the CNF@CaO compound indicated that 26% of the material was composed of CNF; after CaO removal, 84% of the material was composed of CNF. The electrical resistivity of the material drops sharply at concentrations of 2% by weight of CNF and this drop is even more pronounced for samples with 1.2% by weight of washed CaO. This indicates a better dispersion of the material when the CaO is removed. The sensitivity to deformation of the sample with 1.2% by weight of CNF@CaO was quantified as a gauge factor (GF) of 1552, while all other samples showed a GF below 100. Its FCR amplitude can vary inversely up to 8% by means of cyclic compressive loading. The method proposed in this study provides versatility for the fabrication of carbon nanofibers on a tailored substrate to promote self-sensing in cementitious materials.

Effect of preservation solution and distension pressure on saphenous vein's endothelium.

OBJECTIVES: Approaches to improve saphenous vein (SV) patency in coronary artery bypass graft (CABG) surgery remain relevant. This study aimed to evaluate the effects of different preservation solutions and different pressures of intraluminal distention on the endothelium of SV segments in CABG. METHODS: Forty-two SV segments obtained from 12 patients undergoing CABG were divided into 7 groups. Group 1 (control) was prepared without preservation or intraluminal distension, while the other 6 groups were preserved in autologous heparinized autologous arterial blood or normal saline (NS), with distention pressures 30, 100 and 300 mmHg. To assess the effects of using these solutions and pressures on the endothelium, the grafts were analysed by scanning electron microscopy, with the measurement of endothelial damage degree. RESULTS: Segments in group 1 showed minimal endothelial damage. SV grafts preserved with NS had significantly greater endothelial damage both compared to the control group and compared to groups preserved with autologous arterial blood (P < 0.001). Segments distended with pressures up to 100 mmHg showed less damage when compared to those distended at 300 mmHg, with the ones subjected to higher pressures presenting a maximum degree of damage, with considerable loss and separation of endothelial cells, extensive foci of exposure of the basement membrane and numerous fractures of the intimate layer, without differences regarding the solution used. CONCLUSIONS: Preparation of SV using NS and with intraluminal distension pressures above 100 mmHg is factors related to increased damage to the venous endothelium.

Inspiratory Muscle Training Improves Aerobic Capacity in Amateur Indoor Football Players.

Inspiratory muscle training represents a recommended clinical practice to improve physical performance of healthy individuals, athletes, and those with chronic diseases. This study aimed to evaluate whether high- and low-intensity inspiratory muscle training interferes with the aerobic capacity of indoor soccer players. Volunteers were equally and randomly divided into CON (control group, no inspiratory muscle training); HIG (high-intensity group, inspiratory muscle training at 80% of maximal inspiratory pressure, 3 sets of 12 repetitions); and LIG (low-intensity group, inspiratory muscle training at 50% of maximal inspiratory pressure, 2 sets of 20 repetitions). Before and after inspiratory muscle training, maximal inspiratory and expiratory pressures, the incremental shuttle run test, and the 3-min step test were evaluated. Both inspiratory muscle training protocols improved maximal inspiratory and expiratory pressures, and indirect maximal oxygen consumption and distance traveled in the shuttle test compared to CON. However, only HIG achieved significant increases of indirect oxygen consumption and frequency of step rise in the 3-min step test (p<0.05). Inspiratory muscle training is an important tool to enhance maximal inspiratory pressure and exercise tolerance with potential benefits on submaximal aerobic capacity. However, high-intensity inspiratory muscle training improved aerobic capacity in amateur indoor soccer players in both submaximal tests.

Morphological alterations in endometrium after use of levonorgestrel-releasing intrauterine system: a case report / Alterações morflógicas no endométrio após uso de dispositivo intrauterino com liberação de levonorgestrel: relato de caso

Case Report: A 44-year-old patient attended the gynecology service for routine consultation. The patient reported implantation of a levonorgestrel-releasing intrauterine system (LNG-IUS), five years ago. No macroscopic changes were seen in the uterus or in the endometrium cavity during the procedure, but an endometrial biopsy was performed. Histopathological analysis revealed an endometrium with an expanded stroma by pseudo-decidualization and mucoid (mucinous) alterations, forming small puddles of mucin, also presenting with polypoid indentations, ectatic vessels, lymphoid cell foci, including plasma cells and deposits of calcium salts. Conclusion: As the use of this type of contraceptive method becomes more usual, knowledge of LNG-IUS-induced changes becomes increasingly relevant for the assessment of its long-term efficacy and safety.

Relato de Caso: Paciente de 44 anos compareceu ao serviço de ginecologia para consulta de rotina. Relatou implante de dispositivo intrauterino com liberação de levonorgestrel (DIU-LNG) há cinco anos. Durante o exame físico, o fio do dispositivo não foi visualizado. À histeroscopia, para remoção do dispositivo, não foram evidenciadas alterações na cavidade endometrial. Material foi, então, colhido para biópsia. O estudo histopatológico evidenciou um endométrio com estroma expandido por pseudodecidualização e alterações mucoides, formando pequenos aglomerados de mucina, também se apresentando com endentações polipoides, vasos ectásicos, focos de células linfoides e depósitos de sais de cálcio. A presença de DIU-LNG na cavidade uterina causa uma série de alterações histopatológicas e funcionais no endométrio, as quais não são relacionadas, exclusivamente, ao efeito contraceptivo do dispositivo. Conclusão: Com o aumento da utilização desse método anticoncepcional, o conhecimento das alterações provocadas pelo seu uso se torna cada vez mais relevante para avaliação de sua eficácia e segurança em longo prazo.

Intraoperative Analysis of Flow Dynamics in Arteriovenous Composite Y Grafts.

Objective: Composite graft of left internal thoracic artery and great saphenous vein in revascularization of the left coronary system is a technique well described in literature. The aim of this study is to analyze blood flow dynamics in this configuration of composite graft especially in what concerns left internal thoracic artery's adaptability and influence of great saphenous vein segment on left internal thoracic artery's flow. Methods: Revascularization of left coronary system with composite graft, with left internal thoracic artery revascularizing the anterior interventricular artery and a great saphenous vein segment, anastomosed to the left internal thoracic artery, revascularizing another branch of the left coronary system, was performed in 23 patients. Blood flow was evaluated by transit time flowmetry in all segments of the composite graft (left internal thoracic artery proximal segment, left internal thoracic artery distal segment and great saphenous vein segment). Measures were performed in baseline condition and after dobutamine-induced stress, without and with non-traumatic temporary clamping of the distal segments of the composite graft. Results: Pharmacological stress resulted in increase of blood flow values in the analyzed segments (P<0.05). Non-traumatic temporary clamping of great saphenous vein segment did not result in statistically significant changes in the flow of left internal thoracic artery distal segment, both in baseline condition and under pharmacological stress. Similarly, non-traumatic temporary clamping of left internal thoracic artery distal segment did not result in statistically significant changes in great saphenous vein segment flow. Conclusion: Composite grafts with left internal thoracic artery and great saphenous vein for revascularization of left coronary system, resulted in blood flow dynamics with physiological adaptability, both at rest and after pharmacological stress, according to demand. Presence of great saphenous vein segment did not alter physiological blood flow dynamics in distal segment of left internal thoracic artery.

Intraoperative analysis of flow dynamics in arteriovenous composite y grafts

Abstract Objective: Composite graft of left internal thoracic artery and great saphenous vein in revascularization of the left coronary system is a technique well described in literature. The aim of this study is to analyze blood flow dynamics in this configuration of composite graft especially in what concerns left internal thoracic artery's adaptability and influence of great saphenous vein segment on left internal thoracic artery's flow. Methods: Revascularization of left coronary system with composite graft, with left internal thoracic artery revascularizing the anterior interventricular artery and a great saphenous vein segment, anastomosed to the left internal thoracic artery, revascularizing another branch of the left coronary system, was performed in 23 patients. Blood flow was evaluated by transit time flowmetry in all segments of the composite graft (left internal thoracic artery proximal segment, left internal thoracic artery distal segment and great saphenous vein segment). Measures were performed in baseline condition and after dobutamine-induced stress, without and with non-traumatic temporary clamping of the distal segments of the composite graft. Results: Pharmacological stress resulted in increase of blood flow values in the analyzed segments (P<0.05). Non-traumatic temporary clamping of great saphenous vein segment did not result in statistically significant changes in the flow of left internal thoracic artery distal segment, both in baseline condition and under pharmacological stress. Similarly, non-traumatic temporary clamping of left internal thoracic artery distal segment did not result in statistically significant changes in great saphenous vein segment flow. Conclusion: Composite grafts with left internal thoracic artery and great saphenous vein for revascularization of left coronary system, resulted in blood flow dynamics with physiological adaptability, both at rest and after pharmacological stress, according to demand. Presence of great saphenous vein segment did not alter physiological blood flow dynamics in distal segment of left internal thoracic artery.