2,095 research outputs found
Migração de Ponta de Cateter Venoso Central Totalmente Implantado para Veia Jugular Interna Ipsilateral
Introduction: Totally implantable venous access devices (TIVAD) are crucial in the treatment of patients undergoing long-term chemotherapy.Various complications have been documented, including catheter tip migration.Case Description: A TIVAD was introduced to perform chemotherapy on a 64-year-old male with a diagnosis of sigmoid colon cancer.17 months after the introduction of TIVAD, our patient had complaints of pain in the right cervical region, extending from the clavicle to the mandibular area, during a chemotherapy session. Chest X-ray was required to confirm the position of TIVAD, demonstrating catheter tip migration to the ipsilateral internal jugular vein. Increased intrathoracic pressure due to cough and vomiting remains a possible cause for catheter tip migration.Conclusion: the correct position of TIVAD, meaning the tip of the catheter located 1-2 cm below the carina in chest X-ray, is crucial to prevent migration. Chest X-ray could be performed to detect migration. Measures to prevent increased intrathoracic pressure should be taken.Introdução: Dispositivos médicos como o cateter venoso central totalmente implantado (TIVAD) são cruciais no tratamento de pacientes submetidos a quimioterapia de longo prazo.Várias complicações foram documentadas, incluindo a migração da ponta do cateter.Caso Clínico: Foi introduzido um TIVAD para realização de quimioterapia num paciente de 64 anos de idade com diagnóstico de cancro do colon sigmoide. 17 meses após a introdução do TIVAD, o doente apresentou queixas de dor na região cervical direita, desde a clavícula à área mentoneana, durante uma sessão e quimioterapia. Foi realizado radiografia de tórax para confirmar a posição do TIVAD, demonstrando a migração da ponta do cateter para a veia jugular interna ipsilateral. O aumento da pressão intratorácica devido à tosse e vômito podem ser causas possíveis da migração da ponta do cateter.Conclusão: A posição correta do TIVAD, que equivale à ponta do cateter localizado a 1 - 2 cm abaixo da carina na radiografia de tórax, é crucial para prevenir a migração. A radiografia de tórax pode ser realizada para detetar a migração.Devem ser tomadas medidas para prevenir o aumento da pressão intratorácica
Universal behavior at discontinuous quantum phase transitions
Discontinuous quantum phase transitions besides their general interest are
clearly relevant to the study of heavy fermions and magnetic transition metal
compounds. Recent results show that in many systems belonging to these classes
of materials, the magnetic transition changes from second order to first order
as they approach the quantum critical point (QCP). We investigate here some
mechanisms that may be responsible for this change. Specifically the coupling
of the order parameter to soft modes and the competition between different
types of order near the QCP. For weak first order quantum phase transitions
general results are obtained. In particular we describe the thermodynamic
behavior at this transition when it is approached from finite temperatures.
This is the discontinuous equivalent of the non-Fermi liquid trajectory close
to a conventional QCP in a heavy fermion material.Comment: 7 pages, 3 figure
Doppler ultrasonography of the pectinis oculi artery in harpy eagles (Harpia harpyja)
Twenty harpy eagles (Harpia harpyja) without systemic or ocular diseases were examined to measure blood velocity parameters of the pectinis oculi artery using Doppler ultrasonography. Pectinate artery resistive index (RI) and pulsatility index (PI) were investigated using ocular Doppler ultrasonography. The mean RI and PI values across all eyes were 0.44±0.10 and 0.62±0.20 respectively. Low RI and PI values found in the harpy eagle´s pectinis oculi artery compared with the American pekin ducks one and other tissue suggest indeed a high metabolic activity in pecten oculi and corroborates the hypothesis of a nutritional function and/or intraocular pressure regulation.Keywords: Avian posterior segment, Pulsatility index, Raptors, Resistive index
Quantum first order phase transitions
The scaling theory of critical phenomena has been successfully extended for
classical first order transitions even though the correlation length does not
diverge in these transitions. In this paper we apply the scaling ideas to
quantum first order transitions. The usefulness of this approach is illustrated
treating the problems of a superconductor coupled to a gauge field and of a
biquadratic Heisenberg chain, at zero temperature. In both cases there is a
latent energy associated with their discontinuous quantum transitions. We
discuss the effects of disorder and give a general criterion for it's relevance
in these transitions.Comment: 6 pages, 2 figures, misprints corrected and a reference added.
Version published in PHYSICA
Quantum corrections to the phase diagram of heavy-fermion superconductors
The competition between magnetism and Kondo effect is the main effect
determining the phase diagram of heavy fermion systems. It gives rise to a
quantum critical point which governs the low temperature properties of these
materials. However, experimental results made it clear that a fundamental
ingredient is missing in this description, namely superconductivity. In this
paper we make a step forward in the direction of incorporating
superconductivity and study the mutual effects of this phase and
antiferromagnetism in the phase diagram of heavy fermion metals. Our approach
is based on a Ginzburg-Landau theory describing superconductivity and
antiferromagnetism in a metal with quantum corrections taken into account
through an effective potential. The proximity of an antiferromagnetic
instability extends the region of superconductivity in the phase diagram and
drives this transition into a first order one. On the other hand
superconducting quantum fluctuations near a metallic antiferromagnetic quantum
critical point gives rise to a first order transition from a low moment to a
high moment state in the antiferromagnet. Antiferromagnetism and
superconductivity may both collapse at a quantum bicritical point whose
properties we calculate.Comment: 10 pages, 6 figure
Development of a poly(vinyl alcohol)/lysine electrospun membrane-based drug delivery system for improved skin regeneration
Nanofiber-based wound dressings are currently being explored as delivery systems of different biomolecules for avoiding skin infections as well as improve/accelerate the healing process. In the present work, a nanofibrous membrane composed of poly(vinyl alcohol) (PVA) and lysine (Lys) was produced by using the electrospinning technique. Further, anti-inflammatory (ibuprofen (IBP)) and antibacterial (lavender oil (LO)) agents were incorporated within the electrospun membrane through blend electrospinning and surface physical adsorption methods, respectively. The obtained results demonstrated that the PVA_Lys electrospun membranes incorporating IBP or LO displayed the suitable morphological, mechanical and biological properties for enhancing the wound healing process. Moreover, the controlled and sustained release profile attained for IBP was appropriate for the duration of the wound healing inflammatory phase, whereas the initial burst release of LO is crucial to prevent wound bacterial contamination. Indeed, the PVA_Lys_LO electrospun membranes were able to mediate a strong antibacterial activity against both S. aureus and P. aeruginosa, without compromising human fibroblasts viability. Overall, the gathered data emphasizes the potential of the PVA_Lys electrospun membranes-based drug delivery systems to be used as wound dressings.info:eu-repo/semantics/publishedVersio
Littré’s hernia – a case of a Meckel’s diverticulum in a strangulated femoral hernia and literature review
Introdução: O divertículo de Meckel é a anomalia gastrointestinal congénita mais comum e resulta da obliteração incompleta do ducto vitelino. A hérnia de Littré define-se pela presença de um divertículo de Meckel no saco herniário. O estrangulamento do divertículo de Meckel numa hérnia femoral é uma entidade extremamente rara que requer correção cirúrgica imediata.
Caso Clínico: Reportamos o caso clínico de uma mulher de 18 anos que recorreu ao serviço de urgência por uma hérnia femoral dolorosa e encarcerada à esquerda, sem sinais ou sintomas de obstrução intestinal associados. Durante a intervenção cirúrgica, aquando da abertura do saco herniário, foi identificado um divertículo de Meckel, procedendo-se então a diverticulectomia. A ansa de intestino delgado não se encontrava herniada nem tinha sinais de isquemia, pelo que não foi necessário realizar uma enterectomia. O defeito herniário foi subsequentemente corrigido através da técnica de Lichtenstein modificada.
Discussão: A sintomatologia de um divertículo de Meckel complicado é inespecífica e dependente do tipo de complicação. O diagnóstico de hérnia de Littré é exigente e difícil de estabelecer durante o pré-operatório, uma vez que a sua apresentação clínica é ambígua e a imagiologia tem um papel limitado. Quando a obstrução do intestino delgado é provocada por um divertículo de Meckel complicado, a intervenção cirúrgica tem como objetivo principal remover o divertículo e corrigir a patologia associada, independentemente da abordagem utilizada ser laparoscópica ou cirurgia aberta.
Conclusão: No caso de uma hérnia de Littré estrangulada o tratamento é baseado na condição clínica do doente e na experiência do cirurgião. Não obstante, o tratamento requer, pelo menos, uma ressecção completa do divertículo para evitar complicações futuras.Introduction: Meckel’s diverticulum is the most common gastrointestinal congenital anomaly and it results from an incomplete obliteration of the vitelline duct. Littré’s hernia is defined by the presence of a Meckel’s diverticulum in a hernia sac. A strangulated Meckel’s diverticulum in a femoral hernia is an extremely rare entity and its management requires prompt surgery.
Case Report: We describe a case of a 18-year-old woman that presented with a painful incarcerated femoral hernia in her left groin. She did not have any signs or symptoms of bowel obstruction. During surgery, a Meckel’s diverticulum was identified in the hernia sac. The small bowel was not herniated and did not show signs of ischaemia, thus, an enterectomy was not required. A diverticulectomy was performed and the hernia defect was subsequently repaired with a modified Lichtenstein technique.
Discussion: The symptomatology of a complicated Meckel’s diverticulum is non-specific and dependent on the type of complication. The diagnosis of Littré’s hernia is challenging and difficult to establish preoperatively since its presentation is ambiguous and imaging has a limited role. When small bowel obstruction is caused by a complicated Meckel’s diverticulum, the main aim of surgery is to remove the diverticulum and to correct the associated pathology, either by laparoscopy or by an open surgical approach.
Conclusion: A patient’s condition and surgeon based management is generally adopted in case of a strangulated Littré’s hernia. Nevertheless, it requires complete resection of the diverticulum to avoid future complications
Cortisol rapidly increases baroreflex sensitivity of heart rate control, but does not affect cardiac modulation of startle
Cortisol, the final product of human HPA axis activation, rapidly modulates the cortical processing of afferent
signals originating from the cardiovascular system. While peripheral effects have been excluded, it remains
unclear whether this effect is mediated by cortical or subcortical (e.g. brainstem) CNS mechanisms. Cardiac
modulation of startle (CMS) has been proposed as a method to reflect cardio-afferent signals at subcortical
(potentially brainstem-) level. Using a single blind, randomized controlled design, the cortisol group (n = 16
volunteers) received 1 mg cortisol intravenously, while the control group (n = 16) received a placebo substance.
The CMS procedure involved the assessment of eye blink responses to acoustic startle stimuli elicited at six
different latencies to ECG-recorded R-waves (R + 0, 100, 200, 300, 400 and 500 ms). CMS was assessed at four
measurement points: baseline, -16 min, +0 min, and +16 min relative to substance application. Baroreflex
sensitivity (BRS) of heart rate (HR) control was measured non-invasively based on spontaneous beat-to-beat HR
and systolic blood pressure changes. In the cortisol group, salivary cortisol concentration increased after IV
cortisol administration, indicating effective distribution of the substance throughout the body. Furthermore, BRS
increased in the cortisol group after cortisol infusion. There was no effect of cortisol on the CMS effect, however.
These results suggest that low doses of cortisol do not affect baro-afferent signals, but central or efferent components of the arterial baroreflex circuit presumably via rapid, non-genomic mechanisms
Isolation of endophytic bacteria from arboreal species of the Amazon and identification by sequencing of the 16S rRNA encoding gene
Endophytic bacteria from three arboreal species native to the Amazon (Carapa guianenses, Ceiba pentandra, and Swietenia macrophylla), were isolated and identified, through partial sequencing of the 16S rRNA encoding gene. From these, 16 isolates were obtained, although, when compared to sequences deposited in GenBank, only seven had produced identifiable fragments. Bacillus, Pantoea and two non-culturable samples were identified. Results obtained through sequence analysis revealed low genetic diversity across the isolates, even when analyzing different species and plant structures. This is the first report concerning the isolation and identification of endophytic bacteria in these plant species
Lignin-enriched tricalcium phosphate/sodium alginate 3D scaffolds for application in bone tissue regeneration
The bone is a connective, vascularized, and mineralized tissue that confers protection to organs, and participates in the support and locomotion of the human body, maintenance of homeostasis, as well as in hematopoiesis. However, throughout the lifetime, bone defects may arise due to traumas (mechanical fractures), diseases, and/or aging, which when too extensive compromise the ability of the bone to self-regenerate. To surpass such clinical situation, different therapeutic approaches have been pursued. Rapid prototyping techniques using composite materials (consisting of ceramics and polymers) have been used to produce customized 3D structures with osteoinductive and osteoconductive properties. In order to reinforce the mechanical and osteogenic properties of these 3D structures, herein, a new 3D scaffold was produced through the layer-by-layer deposition of a tricalcium phosphate (TCP), sodium alginate (SA), and lignin (LG) mixture using the Fab@Home 3D-Plotter. Three different TCP/LG/SA formulations, LG/SA ratio 1:3, 1:2, or 1:1, were produced and subsequently evaluated to determine their suitability for bone regeneration. The physicochemical assays demonstrated that the LG inclusion improved the mechanical resistance of the scaffolds, particularly in the 1:2 ratio, since a 15 % increase in the mechanical strength was observed. Moreover, all TCP/LG/SA formulations showed an enhanced wettability and maintained their capacity to promote the osteoblasts' adhesion and proliferation as well as their bioactivity (formation of hydroxyapatite crystals). Such results support the LG inclusion and application in the development of 3D scaffolds aimed for bone regeneration.info:eu-repo/semantics/publishedVersio
- …