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71.
Julliana Marques R. de Figueirêdo Fabiana Pereira da Costa Jucielle Veras Fernandes Alisson Mendes Rodrigues Gelmires de Araújo Neves Romualdo Rodrigues Menezes Lisiane Navarro de Lima Santana 《Materials》2020,13(22)
New ceramic formulations based on scheelite tailing were developed, and their potential in the ceramic industry was evaluated. Green bodies with different contents of scheelite tailing (0–8 wt%) were sintered (1150 °C, 1200 °C, and 1250 °C) and characterized in terms of the main mineralogical phases, microstructure, and physico-mechanical properties. The mullite was the main phase identified in all sintered temperatures. This result was also ratified with the aid of scanning electron microscope (SEM) images, in which small needles of the mullite were detected. The presence of mullite is required because it contributes to increasing the mechanical resistance of the material. The physico-mechanical properties measured (water absorption, linear shrinkage, apparent porosity, and flexural strength) were compared to the ISO 13006, and the samples sintered at 1150 °C presented potential to be used as semi-stoneware, while those sintered at 1200 °C and 1250 °C can be employed stoneware and porcelain tiles, respectively. 相似文献
72.
Luiz Schweitzer Alexandre Cunha Thiago Pereira Kerstin Mika Ana Maria Botelho do Rego Ana Maria Ferraria Heinz Kieburg Sven Geissler Eckart Uhlmann Janosch Schoon 《Materials》2020,13(23)
Loosening of orthodontic and orthopedic implants is a critical and common clinical problem. To minimize the numbers of revision surgeries due to peri-implant inflammation or insufficient osseointegration, developments of new implant manufacturing strategies are indicated. Ultrafast laser surface texturing is a promising contact-free technology to modify the physicochemical properties of surfaces toward an anti-infectious functionalization. This work aims to texture Ti6Al4V surfaces with ultraviolet (UV) and green (GR) radiation for the manufacturing of laser-induced periodic surface structures (LIPSS). The assessment of these surface modifications addresses key aspects of topography, morphology and chemical composition. Human primary mesenchymal stromal cells (hMSCs) were cultured on laser-textured and polished Ti6Al4V to characterize the surfaces in terms of their in vitro biocompatibility, cytotoxicity, and metal release. The outcomes of the in vitro experiment show the successful culture of hMSCs on textured Ti6Al4V surfaces developed within this work. Cells cultured on LIPSS surfaces were not compromised in terms of their viability if compared to polished surfaces. Yet, the hMSC culture on UV-LIPSS show significantly lower lactate dehydrogenase and titanium release into the supernatant compared to polished. Thus, the presented surface modification can be a promising approach for future applications in orthodontics and orthopedics. 相似文献
73.
Alexandre Kanashiro Thais Oliveira de Lucena Leoncio Ayda Henriques Schneider Hélio Rocha Alves Gabriel Shimizu Bassi Sabrina Graziani Veloso Dutra Fernando de Queiróz Cunha Luis Ulloa David do Carmo Malvar 《Pharmacological reports : PR》2019,71(6):1095-1103
BackgroundThe regulation of the immune system by the sympathetic nervous system is allowing the design of novel treatments for inflammatory disorders such as arthritis. In this study, we have analyzed the effects of α- and β-adrenoceptor agonists injected subcutaneously, intrathecally, or intra-articularly in zymosan-induced arthritis.MethodsMurine arthritis was induced by intra-articular (knee joint) injection of zymosan. α1 (phenylephrine), α2 (clonidine), β1 (dobutamine), or β2 (salbutamol)-adrenoceptor agonists were injected subcutaneously (sc), intrathecally (it), or intra-articularly (ia) to activate peripheral, spinal, or intra-articular adrenoceptors and to study their effects on articular edema formation and neutrophil migration into the synovial cavity.ResultsTreatments with phenylephrine did not affect the edema formation, but it increased neutrophil migration when injected subcutaneously (155.3%) or intra-articularly (187.7%). Treatments with clonidine inhibited neutrophil migration (59.9% sc, 68.7% it, 42.8% ia) regardless of the route of administration, but it inhibited edema formation only when injected intrathecally (66.7%) or intra-articularly (36%) but not subcutaneously. Treatments with dobutamine inhibited both edema (42.0% sc, 69.5% it, 61.6% ia) and neutrophil migration (28.4% sc, 70.3% it, 82.4% ia) in a concentration dependent manner. Likewise, all the treatments with salbutamol also inhibited edema formation (89.9% sc, 62.4% it, 69.8% ia) and neutrophil migration (76.6% sc, 39.1% it, 71.7% ia).ConclusionWhereas the β-adrenoceptor agonists induced anti-inflammatory effects regardless of their route of administration, α1- and α2-adrenoceptor agonists induced either pro- and anti-inflammatory effects, respectively. 相似文献
74.
Tadeu Uggere de Andrade Silvia Cruz Goes Coutinho Haguihara Raiana Maria Prucoli Falsoni Cristiane Lyrio da Silva Dionísio Gonzaga Dubois Filho Flvia de Souza Andrade Moraes Andrews Marques do Nascimento Girlandia Alexandre Brasil Ewelyne Miranda de Lima 《Basic & clinical pharmacology & toxicology》2019,124(4):360-369
The aim of the study was to evaluate the effect of an anabolic steroid, stanozolol, in a model of atherosclerosis and to investigate the involvement of the modulation of the inflammatory cytokines and oxidative stress in vascular lipid deposition. Low‐density lipid receptor‐deficient (LDLr?/?) mice were fed a standard chow diet and were each week injected subcutaneously either saline (control C group) or 20 mg/kg stanozolol (S group). After 8 weeks, the levels of cholesterol, oxidized LDL (OxLDL) and cytokines were measured in plasma, lipid deposition in aorta was evaluated by en face analysis, and thiobarbituric acid‐reactive substances and oxidation protein were determined in liver. The S group demonstrated increases in vascular lipid deposition, triglycerides and non‐HDL cholesterol levels. Stanozolol increased tumour necrosis factor alpha (TNF‐α) and decreased interleukin‐10 as well as increased the TNF‐α/IL‐10 ratio. Furthermore, oxidative stress was observed in the S group, as indicated by an increase in the plasma OxLDL, as well as by lipid peroxidation and oxidation of proteins in the liver. Chronic treatment with stanozolol promoted lipid deposition in the LDLr?/? mice that could be attributed to a modification of the circulating cytokine levels and systemic oxidative stress. Our results suggest that the anabolic steroid stanozolol in the absence of functional LDL receptors by increasing systemic inflammation and oxidative stress may increase the risk of development and progression of atherosclerosis. 相似文献
75.
Tatiani Botelho Vinícius B. Marques Maylla R. Simes Patricia R. do Val Lima Fabiana V. Simes Dalton V. Vassallo Leonardo dos Santos 《Basic & clinical pharmacology & toxicology》2019,124(2):190-198
Mercury intoxication is a public health risk factor due to its hazardous effect to several organs, including the cardiovascular system. There is evidence of endothelial dysfunction after exposure to mercury, but the effects on endothelium‐dependent vasodilatation are still unknown. In the present study, we aimed to evaluate the chronic effects of high HgCl2 doses on the mechanisms of vasodilatation. Wistar rats were injected with HgCl2 (1st dose 10.86 μg/kg, and daily doses 0.014 μg/kg for 30 days i.m.), and saline was used as control. Mercury exposure reduced the acetylcholine‐induced vasodilatation in aortic rings, which was restored by incubation with antioxidant tiron. Inhibition of the NO synthase, Na+/K+‐ATPase and K+ channels indicates reduced participation of these factors. In the mercury group, there were an increased local anion superoxide and a reduced NO. The vasodilatation to exogenous NO was partially inhibited by co‐incubation with TEA plus tiron, suggesting that reduced NO bioavailability is the responsible to that decreased the participation of K+ channels. Moreover, there was an increased participation of the Na+/K+‐ATPase associated with an up‐regulation of its alpha‐1 subunit. In conclusion, reduced NO bioavailability plays a major role in the impaired participation of K+ channels and Na+/K+‐ATPase in the acetylcholine‐mediated relaxation, although sodium pump is up‐regulated probably as a compensatory mechanism. 相似文献
76.
77.
Melissa Carvalho Machado do Couto Marcelo de Freitas Lima Teresa Cristina Bergamo do Bomfim 《Acta tropica》2014
Bovine cryptosporidiosis is mainly caused by four distinct species: Cryptosporidium parvum, C. bovis, C. ryanae and C. andersoni. The first, C. parvum, is a major concern in livestock causing economic losses, in addition to public health impact because of its zoonotic characteristics. The present study aimed to determine the occurrence of different species and subtypes of Cryptosporidium using molecular techniques. A total of 143 fecal samples were collected from calves from three dairy farms located in the state of Rio de Janeiro, Brazil. Saturated sugar centrifugal flotation method was used for the microscopic evaluation of the samples. Among these samples, 19.6% (28) were positive by microscopy, and 82.1% (23) of these 28 samples had their diagnosis confirmed by PCR using 18S as gene target. After sequencing, three species of Cryptosporidium were found to infect calves in different age groups. In pre-weaning phase (<2 months), 10% (3/30) of the calves were infected with C. parvum, whereas 14.2% (16/113) of post-weaning calves (≥2 months) were observed to be infected with C. andersoni and 1.8% (2/113) by C. ryanae with the latter diagnosed for the first time in the state of Rio de Janeiro. Those samples identified as C. parvum were further characterized at the GP60 locus, and PCR products were cloned. Eight different subtypes (IIaA20G2R1, IIaA20G2R2, IIaA19G2R1, IIaA19G2R2, IIaA18G1R1, IIaA18G2R2, IIaA16G3R2 and IIaA14G2R2) of C. parvum were identified, all belonging to the IIa family subtype, which is considered of high zoonotic potential. The subtypes mentioned above have not yet been detected in Brazilian cattle, and four of these subtypes (IIaA20G2R2, IIaA19G2R2, IIaA18G2R2 and IIaA14G2R2) had not been diagnosed elsewhere in calves until this study. 相似文献
78.
79.
80.
de Oliveira JA do Amaral Escada AL Alves Rezende MC Mathor MB Alves Claro AP 《Clinical oral implants research》2012,23(4):511-514
Objective: The purpose of the present study was to evaluate the influence of radiation in osseointegrated dental implants installed in tibiae of rats. Material and methods: Screw‐shaped implants (2.5 mm diameter by 3.5 mm length) were custom made from commercially pure titanium bars. Titanium implants were blasted and sterilized before implantation. Animals were divided into two groups of 12 animals each and the rats were not paired after the groups' formation. The experimental group (group 1) received external irradiation 4 weeks after surgery while in the control group (group 2) animals were kept free of radiation. The shear strength required to detach the implant from bone was measured by push‐out testing and osseointegration was histologically evaluated. Results: Results showed that the compressive strength of irradiated implants (33.49 MPa) was significantly lower than the compressive strength of non‐irradiated implants (48.05 MPa). Conclusions: We concluded that the mechanical strength bonding between implants and host tissues decreased after irradiation. To cite this article: Oliveira JAG, Escada ALA, Alves Rezende MCR, Mathor MB, Alves Claro APR. Analysis of the effects of irradiation in osseointegrated dental implants.Clin. Oral Impl. Res. 23 , 2012 511–514.doi: 10.1111/j.1600‐0501.2010.02149.x 相似文献