80 research outputs found
Preparation of hybrid samples for scanning electron microscopy (SEM) coupled to focused ion beam (FIB) analysis: A new way to study cell adhesion to titanium implant surfaces.
The study of the intimate connection occurring at the interface between cells and titanium implant surfaces is a major challenge for dental materials scientists. Indeed, several imaging techniques have been developed and optimized in the last decades, but an optimal method has not been described yet. The combination of the scanning electron microscopy (SEM) with a focused ion beam (FIB), represents a pioneering and interesting tool to allow the investigation of the relationship occurring at the interface between cells and biomaterials, including titanium. However, major caveats concerning the nature of the biological structures, which are not conductive materials, and the physico-chemical properties of titanium (i.e. color, surface topography), require a fine and accurate preparation of the sample before its imaging. Hence, the aim of the present work is to provide a suitable protocol for cell-titanium sample preparation before imaging by SEM-FIB. The concepts presented in this paper are also transferrable to other fields of biomaterials research
Aptamer-Mediated Selective Protein Affinity to Improve Scaffold Biocompatibility
Protein adsorption on surfaces occurs shortly after scaffold insertion. This process is of pivotal importance to achieve therapeutic success in tissue engineering (TE), and favorable proteins should be adsorbed at the interface without unfolding to preserve their structure and function. Protein misfolding at the interface is a common phenomenon, which can impair cell adhesion and scaffold colonization. Many efforts have been done to improve scaffold biocompatibility by ameliorating protein adsorption, but with poor results. In the present chapter, we propose the use of a novel class of molecules, aptamers, to improve scaffold biocompatibility. Aptamers are small, single stranded oligonucleotides, which specifically bind to a target molecule: they work as antibodies, but without many of the drawbacks associated to the use of antibodies. We propose to immobilize aptamers on scaffolds to retain specific proteins, acting as docking points to guide cell activity. In particular, we show the results obtained by enriching different polymeric scaffolds with aptamers against human fibronectin, a naturally abundant protein in tissues, which plays a pivotal role in cell adhesion. We demonstrate that scaffold enrichment with aptamers lead to a better colonization of the substrate from cells. The results we obtained pave the way to the possibility of further investigating the role of aptamers as useful molecules to improve scaffold biocompatibility in the contest of tissue engineering
Tuberculosis among HIV-1-infected subjects in a tertiary out-patient service in São Paulo city, Brazil
Atualmente, a tuberculose (TB) é considerada a doença infecciosa mais importante entre os pacientes infectados pelo HIV-1 nos países em desenvolvimento, como o Brasil. Análise retrospectiva dos casos de tuberculose ocorridos a partir de janeiro 1995 até dezembro de 2010 foi realizada em nossa coorte de 599 pacientes HIV positivos. O desfecho primário foi a ocorrência de TB ativa, e 41 casos da doença foram diagnosticados durante este período de 16 anos. As contagens médias do nadir de células T CD4 e ao momento do diagnóstico de TB foram de 146 e 217 células/mm³, respectivamente. A carga viral média de HIV foi de 5,19 log10 cópias/mL, e 59% dos pacientes estavam em tratamento com ART. A incidência de TB foi de 1,47 casos por 100 pessoas-ano, para um tempo total de seguimento da coorte de 2775 pessoas-ano. A probabilidade de sobreviver até 10 anos após o diagnóstico foi de 75% para pacientes com TB, em oposição a 96% para pacientes com outras doenças oportunistas não-TB (p = 0,03). A tuberculose pode ser considerada problema de saúde pública entre as pessoas que vivem com HIV no Brasil, apesar da ampla utilização de anti-retrovirais para o tratamento da infecção pelo HIV / AIDS.TB is currently considered to be the most important infectious disease among HIV-1-infected subjects in developing countries, such as Brazil. A retrospective analysis of TB cases was performed, occurring from January 1995 to December 2010 in our cohort of 599 HIV positive patients. The primary outcome was the occurrence of active TB. Forty-one TB cases were diagnosed over this period of 16 years, among 599 HIV positive patients in an open cohort setting in the city of Sao Paulo, Brazil. All-time lowest mean CD4 T cell count at the time of TB diagnosis was 146 and 186 cells/mm³, respectively. The mean HIV viral load was 5.19 log10 copies/mL, and 59% of the patients were on HAART. TB incidence was 1.47 per 100 person-years, for a total follow-up time of 2775 person-years. The probability of surviving up to 10 years after diagnosis was 75% for TB patients as opposed to 96% for patients with other, non-TB opportunistic diseases (p = 0.03). TB can be considered a public health problem among people living with HIV in Brazil despite of the widespread use of antiretrovirals for the treatment of HIV infection/AIDS
Synthetic recovery of impulse propagation in myocardial infarction via silicon carbide semiconductive nanowires
: Myocardial infarction causes 7.3 million deaths worldwide, mostly for fibrillation that electrically originates from the damaged areas of the left ventricle. Conventional cardiac bypass graft and percutaneous coronary interventions allow reperfusion of the downstream tissue but do not counteract the bioelectrical alteration originated from the infarct area. Genetic, cellular, and tissue engineering therapies are promising avenues but require days/months for permitting proper functional tissue regeneration. Here we engineered biocompatible silicon carbide semiconductive nanowires that synthetically couple, via membrane nanobridge formations, isolated beating cardiomyocytes over distance, restoring physiological cell-cell conductance, thereby permitting the synchronization of bioelectrical activity in otherwise uncoupled cells. Local in-situ multiple injections of nanowires in the left ventricular infarcted regions allow rapid reinstatement of impulse propagation across damaged areas and recover electrogram parameters and conduction velocity. Here we propose this nanomedical intervention as a strategy for reducing ventricular arrhythmia after acute myocardial infarction
PEDOT:PSS interfaces support the development of neuronal synaptic networks with reduced neuroglia response in vitro
The design of electrodes based on conductive polymers in brain-machine interface technology offers the opportunity to exploit variably manufactured materials to reduce gliosis, indeed the most common brain response to chronically implanted neural electrodes. In fact, the use of conductive polymers, finely tailored in their physical-chemical properties, might result in electrodes with improved adaptability to the brain tissue and increased charge-transfer efficiency. Here we interfaced poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) doped with different amounts of ethylene glycol (EG) with rat hippocampal primary cultures grown for 3 weeks on these synthetic substrates. We used immunofluorescence and scanning electron microscopy combined to single cell electrophysiology to assess the biocompatibility of PEDOT:PSS in terms of neuronal growth and synapse formation. We investigated neuronal morphology, density and electrical activity. We reported the novel observation that opposite to neurons, glial cell density was progressively reduced, hinting at the ability of this material to down regulate glial reaction. Thus PEDOT:PSS is an attractive candidate for the design of new implantable electrodes, controlling the extent of glial reactivity without affecting neuronal viability and function
Critical literacy as a pedagogical goal in English language teaching
In this chapter, the authors provide an overview of the area of critical literacy as it pertains to second language pedagogy (curriculum and instruction). After considering the historical origins of critical literacy (from antiquity, and including in first language education), they consider how it began to penetrate the field of applied linguistics. They note the geographical and institutional spread of critical literacy practice as documented by published accounts. They then sketch the main features of L2 critical literacy practice. To do this, they acknowledge how practitioners have reported on their practices regarding classroom content and process. The authors also draw attention to the outcomes of these practices as well as challenges that practitioners have encountered in incorporating critical literacy into their second language classrooms
Efeito da Analgesia Preventiva na Redução da Dor Pós-Operatória: Uma Análise Abrangente
This article explores the significant intersection between anesthesia and chronic pain therapy in cancer patients, highlighting the importance of these approaches in the context of treating various neoplastic conditions. Anesthesia plays a crucial role in surgical procedures and therapeutic interventions, requiring a comprehensive analysis of available options to ensure the safety and comfort of patients. When considering different anesthetic techniques, the goal is to provide healthcare professionals with an in-depth understanding of the latest and most effective strategies, taking into account factors such as postoperative recovery and acute pain management.
The choice of anesthetic approach in cancer patients is multifaceted, influenced by variables such as the type of intervention, the patient's overall health, and the specificities of the neoplastic condition. In this context, the comparative analysis of different anesthetic techniques, such as regional and general approaches, becomes essential to ensure treatment effectiveness and minimize adverse impacts.
Furthermore, chronic pain therapy in cancer patients is a complex challenge that requires an integrated approach. This article examines various therapeutic modalities, from pharmacological interventions to non-pharmacological methods, with the aim of providing valuable insights to optimize chronic pain management and improve post-treatment quality of life. Understanding the complexities and nuances of these therapies is essential to ensure comprehensive and personalized care for cancer patients, emphasizing the importance of a holistic approach in managing chronic pain in an oncological context.
Finally, this article seeks to consolidate up-to-date information on anesthesia and chronic pain therapy in cancer patients, offering a critical review of available scientific literature. The goal is to contribute to the continuous development of clinical practices in this area, promoting the effectiveness of procedures and improving the quality of life for patients facing this challenging condition.Este artigo explora a significativa interseção entre a anestesia e a terapia de dor crônica em pacientes oncológicos, destacando a importância dessas abordagens no contexto do tratamento de diversas condições neoplásicas. A anestesia desempenha um papel crucial em procedimentos cirúrgicos e intervenções terapêuticas, exigindo uma análise abrangente das opções disponíveis para garantir a segurança e o conforto dos pacientes. Ao considerar diferentes técnicas anestésicas, o objetivo é fornecer aos profissionais de saúde uma visão aprofundada das estratégias mais recentes e eficazes, levando em conta fatores como a recuperação pós-operatória e o manejo da dor aguda.
A escolha da abordagem anestésica em pacientes oncológicos é multifacetada, influenciada por variáveis como o tipo de intervenção, estado de saúde geral do paciente e especificidades da condição neoplásica. Neste contexto, a análise comparativa de diferentes técnicas anestésicas, como abordagens regionais e gerais, torna-se essencial para garantir a eficácia do tratamento e minimizar os impactos adversos.
Além disso, a terapia de dor crônica em pacientes oncológicos é um desafio complexo que requer uma abordagem integrada. Este artigo examina diversas modalidades terapêuticas, desde intervenções farmacológicas até métodos não farmacológicos, com o intuito de fornecer insights valiosos para otimizar o manejo da dor crônica e melhorar a qualidade de vida pós-tratamento. A compreensão das complexidades e nuances dessas terapias é essencial para garantir um cuidado abrangente e personalizado aos pacientes oncológicos, destacando a importância de uma abordagem holística na gestão da dor crônica em contexto oncológico.
Por fim, este artigo busca consolidar informações atualizadas sobre anestesia e terapia de dor crônica em pacientes oncológicos, oferecendo uma revisão crítica da literatura científica disponível. O objetivo é contribuir para o desenvolvimento contínuo das práticas clínicas nessa área, promovendo a eficácia dos procedimentos e a melhoria da qualidade de vida para os pacientes que enfrentam essa condição desafiadora.
 
Spaghet: a coenocline simulator useful to calibrate software detectors
A coenocline simulator is described, which allows one to calibrate programs or chains of programs before using them on survey data. An example is given, and the listings of two versions of the simulator, in BASIC and FORTRAN respectively
Dialoghi tra un religioso direttore ad un sacerdote novello : en' quali ... si trattano le più importanti materie ecclesiastiche : operatta utilissima a`´sacerdoti novelli
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