An in vitro study on the antibacterial effects of chlorhexidine-loaded positively charged silver nanoparticles on Enterococcus faecalis

This study successfully developed a positively charged silver nanocomplex as a nanocarrier for chlorhexidine (CHX) using ionic liquids. This nanocomplex can interestingly deliver the antibacterial agent with a synergistic effect. In this study, we synthetized and characterized a positively charged silver nanocomplex (AgNPs+) and CHX-loaded positively charged silver nanoparticles (CHX@AgNPs+) using UV-visible spectroscopy, transmission electron microscopy, X-ray diffractometer, Fourier transform infrared spectroscopy, and Zetasizer. Then, the loading efficiency and release profile of XHX from nanocomplex were evaluated. The antibacterial activity was evaluated by employing two standard microdilution tests to obtain the minimum bactericidal and inhibitory concentrations. The average sizes of 27.43 nm and 29.66 nm were obtained for AgNPs+ and CHX@AgNPs+, respectively. The CHX@AgNPs+ showed a constant release of CHX, making them a more effective antibacterial agent against Enterococcus faecalis (E. faecalis) than CHX or AgNPs+ alone. Antibacterial assays showed that CHX@AgNPs+ significantly reduced the viability of the bacterial strain compared to CHX as the standard irrigant. AgNPs+ had an antibacterial effect similar to CHX only at intermediate concentrations (12 and 25 μg/mL), and their effects were significantly less than those of CHX at other concentrations (3, 6, 50, and 100 μg/mL). The effects of CHX@AgNPs+ were statistically greater than those of AgNPs+ at all concentrations tested. The MIC values of CHX@AgNPs+ and CHX were 50 and 100 μg/mL. However, AgNPs+ were not showed MIC value at tested concentrations. Therefore, the designed nanocomplex can be regarded as a potential root canal disinfectant with clinical applications for bacterial infections

Functional recovery of sciatic nerve through inside-out vein graft in rats

AbstractObjectivePresent study aimed at further comprehensive functional, histomorphometrical and immunohistochemical assessment of peripheral nerve regeneration using rat sciatic nerve transection model.MethodsThe 10-mm rat sciatic nerve gap was created in rats. In control group nerve stumps were sutured to adjacent muscle and in treatment group the gap was bridged using an inside-out vein graft. In sham-operated group the nerve was manipulated and left intact. All animals underwent walking track analysis test 4, 8, and 12 weeks after surgery. Subsequently, muscle mass measurement was performed to assess reenervation, histological examination to observe the sciatic nerve regeneration morphologically and Immunohistochemistry to detect Schwann cells using anti S-100. Results were analyzed using a factorial ANOVA with two between-subjects factors. Bonferroni test for pairwise comparisons was used to examine the effect of treatments.ResultsFunctional analysis of myelinated nerve fibers showed that nerve function improved significantly in the time course in treatment group. However, quantitative morphometrical analysis of myelinated nerve fibers showed that there was no significant difference between 8 and 12 weeks in treatment group. Muscle weight ratio was bigger and weight loss of the gastrocnemius muscle was ameliorated by inside-out vein grafting. The position of positive immunohistochemical reactions further implied that regenerated axons and Schwann cell-like cells existed after vein grafting was performed, and was accompanied by the process of myelination and structural recovery of regenerated nerves.ConclusionFunctional analysis of peripheral nerve repair is far more reliable than quantitative morphometrical analysi

Excitatory versus inhibitory feedback in Bayesian formulations of scene construction

La investigación que se presenta en este trabajo, siendo de enfoque cuantitativo, tiene el objetivo de obtener la relación que hay entre las fases del neuromarketing y los elementos de la publicidad animada “Todo va a estar bien” de Rímac Seguros en los alumnos de la facultad de comunicaciones de la Universidad de Ciencias y Artes de América Latina (Lima 2017). Para su resultado, se utilizó el diseño correlacional, en un tipo de investigación no experimental. El nivel de ésta es descriptiva - correlacional y su método de investigación deductivo, inductivo y técnica estadística para conseguir los resultados precisos en una muestra de 50 estudiantes para su análisis utilizando la encuesta como instrumento de medición. Se llega a la conclusión de tener una relación entre las fases del neuromarketing y los elementos de la animación publicitaria de Rímac Seguros en este tipo de público estudiado, confirmando las hipótesis que se plantearon desde el principio

Assessment of electrocardiogram interpretation competency among healthcare professionals and students of Ardabil University of Medical Sciences: A multidisciplinary study

Background: Electrocardiogram (ECG) interpretation is a core clinical skill that helps to rapid diagnosis of potentially life-threatening diseases. Misinterpretation of the electrocardiogram can lead to inappropriate clinical decisions with adverse outcomes. The main aim of this survey was to assess the competency of electrocardiogram interpretation and related factors among healthcare professionals and students of Ardabil University of Medical Sciences. Methods: This descriptive cross-sectional study included 323 staff and students of Ardabil University of Medical Sciences in northwestern Iran. Data were collected randomly from November to January 1400 using the Badell-Coll ECG Interpretation Competency Questionnaire and analyzed using SPSS V.14. Statistical analysis included descriptive statistics, independent t-test, ANOVA, Pearson correlation coefficient and multiple linear regression. Results: The results showed that the mean and standard deviation of electrocardiogram interpretation competency of health professional staff and students was 5.13 ± 2.25 (maximum score = 10). The large number of participants wasn’t able to identify normal sinus rhythm (n = 251, 77.3%), acute myocardial infarction (n = 206, 63.8%) and pathological Q waves (n = 201, 62.2%). The results of multiple linear regression showed that the variables of education level, self-assessment of electrocardiogram interpretation competence, work experience, and type of hospital were able to predict the competence of ECG interpretation in participants. Conclusions: Our findings showed that the participants’ level of electrocardiogram interpretation competency was low. Hence, regular, standard training and education are recommended. Also, managers and educators of the health system should consider the role of positive self-assessment and exposure to ECG interpretation in improving the competence of staff and students to interpret ECG

3D Printing of Dental Prostheses: Current and Emerging Applications

Revolutionary fabrication technologies such as three-dimensional (3D) printing to develop dental structures are expected to replace traditional methods due to their ability to establish constructs with the required mechanical properties and detailed structures. Three-dimensional printing, as an additive manufacturing approach, has the potential to rapidly fabricate complex dental prostheses by employing a bottom-up strategy in a layer-by-layer fashion. This new technology allows dentists to extend their degree of freedom in selecting, creating, and performing the required treatments. Three-dimensional printing has been narrowly employed in the fabrication of various kinds of prostheses and implants. There is still an on-demand production procedure that offers a reasonable method with superior efficiency to engineer multifaceted dental constructs. This review article aims to cover the most recent applications of 3D printing techniques in the manufacturing of dental prosthetics. More specifically, after describing various 3D printing techniques and their advantages/disadvantages, the applications of 3D printing in dental prostheses are elaborated in various examples in the literature. Different 3D printing techniques have the capability to use different materials, including thermoplastic polymers, ceramics, and metals with distinctive suitability for dental applications, which are discussed in this article. The relevant limitations and challenges that currently limit the efficacy of 3D printing in this field are also reviewed. This review article has employed five major scientific databases, including Google Scholar, PubMed, ScienceDirect, Web of Science, and Scopus, with appropriate keywords to find the most relevant literature in the subject of dental prostheses 3D printing

Levosimendan exerts anticonvulsant properties against PTZ-induced seizures in mice through activation of nNOS/NO pathway: Role for K<inf>ATP</inf> channel

Aims Although approving new anticonvulsants was a major breakthrough in the field of epilepsy control, so far we have met limited success in almost one third of patients suffering from epilepsy and a definite and reliable method is yet to be found. Levosimendan demonstrated neuroprotective effects and reduced mortality in conditions in which seizure can be an etiology of death; however, the underlying neuroprotective mechanisms of levosimendan still eludes us. In the light of evidence suggesting levosimendan can be a KATP channel opener and nitrergic pathway activator, levosimendan may exert antiseizure effects through KATP channels and nitrergic pathway. Main methods In this study, the effects of levosimendan on seizure susceptibility was studied by PTZ-induced seizures model in mice. Key findings Administration of a single effective dose of levosimendan significantly increased seizures threshold and the nitrite level in the hippocampus and temporal cortex. Pretreatment with noneffective doses of glibenclamide (a KATP channel blocker) and L-NAME (a non-selective NOS inhibitor) neutralize the anticonvulsant and nitrite elevating effects of levosimendan. While 7-NI (a neural NOS inhibitor) blocked the anticonvulsant effect of levosimendan, Aminoguanidine (an inducible NOS inhibitor) failed to affect the anticonvulsant effects of levosimendan. Cromakalim (a KATP channel opener) or L-arginine (an NO precursor) augmented the anticonvulsant effects of a subeffective dose of levosimendan. Moreover, co-administration of noneffective doses of Glibenclamide and L-NAME demonstrated a synergistic effect in blocking the anticonvulsant effects of levosimendan. Significance Levosimendan has anticonvulsant effects possibly via KATP/nNOS/NO pathway activation in the hippocampus and temporal corte