Aim
To analyse the influence of H2O2 on pulp repair through osteocalcin and osteopontin immunolabelling and in cellular defence by using the antireactive oxygen species (ROS) antibody.
Methodology
...The maxillary molars of 50 rats were treated with 35% H2O2 (Ble groups) or placebo gel (control groups). At 0 h and 2, 7, 15 and 30 days (n = 10 hemimaxillae), the rats were killed and pulp tissue was evaluated using inflammation and immunolabelling scores (osteocalcin/osteopontin); ROS‐positive cells were counted. Paired t‐test and Wilcoxon signed‐rank test were used (P < 0.05).
Results
The Ble group had necrosis in the coronal pulp at 0 h and in the occlusal third of the coronal pulp at 2 days; at 7, 15 and 30 days, no inflammation was noted similar to the controls (P > 0.05). Osteocalcin was absent in the Ble at 0 h, moderate at 2 days and increased thereafter, differing from the controls at all two periods (P < 0.05). Osteopontin was higher principally at 7 and 15 days in Ble groups, but differing with control groups from 2 days after bleaching (P < 0.05). The Ble group had more ROS‐positive cells in the pulp at 7 and 15 days (P < 0.05). Tertiary dentine was observed at 7 days, increasing thereafter (P < 0.05).
Conclusions
Post‐bleaching pulp repair was associated with increased osteocalcin over time. Osteopontin also participated in this process, and anti‐ROS was involved in cellular defence against H2O2.
Aim
To evaluate the biocompatibility, induction of mineralization and antimicrobial activity of experimental intracanal pastes based on two glass and glass‐ceramic materials. Calcium hydroxide ...(Ca(OH)2) paste was used as the positive control.
Methodology
The glass‐ceramic powder two‐phased Biosilicate (BS‐2P) and F18 bioactive glass were mixed with distilled water (ratio 2 : 1), inserted in polyethylene tubes and implanted in the subcutaneous tissues of 16 rats. Empty tubes were used as negative control. After 7 and 30 days (n = 8), the rats were euthanized for haematoxylin–eosin, von Kossa, polarized light and osteopontin (OPN) immunolabeling analysis. Direct contact tests using a suspension of each paste were performed with Enterococcus faecalis planktonic cells to evaluate antimicrobial activity (24 h of contact), in a pilot study. The number of CFU mL−1 was calculated for each group. The antimicrobial analysis data were submitted to one‐way anova and Tukey tests, whilst biocompatibility and immunohistochemical data were submitted to the Kruskal–Wallis and Dunn tests (P < 0.05).
Results
Most specimens of the control, BS‐2P and Ca(OH)2 groups were associated with moderate inflammation seven days following implantation, whilst F18 was associated with moderate to severe inflammation, without differences amongst the groups (P > 0.05). At 30 days, most specimens of control, F18 and BS‐2P groups had mild inflammation, whilst Ca(OH)2 had mild to moderate inflammation; however, no differences were determined amongst the groups (P > 0.05). The fibrous capsule was thick at 7 days, becoming thin at 30 days. All pastes induced von Kossa‐positive structures and were birefringent to polarized light. At seven days, the BS‐2P group had significantly more OPN immunolabeling compared to the control and Ca(OH)2 groups (P < 0.05). At 30 days, the F18 group had significantly more OPN immunolabeling compared to the control and Ca(OH)2 groups (P < 0.05). All pastes reduced the total number of E. faecalis; however, the reduction was only significant when comparing BS‐2P and Ca(OH)2 groups to the control (P < 0.05). Only calcium hydroxide eliminated E. faecalis.
Conclusions
Experimental BS‐2P and F18 pastes were biocompatible, stimulated biomineralization and induced significant OPN immunolabeling compared to Ca(OH)2. Only the BS‐2P paste demonstrated antimicrobial activity comparable to Ca(OH)2.
•Surface tension of fluorinated ionic liquids.•Thermophysical properties of fluorinated ionic liquids.•Thermal properties and thermodynamic functions.
This paper reports the thermal, thermodynamic, ...thermophysical and surface properties of eight ionic liquids with fluorinated alkyl side chain lengths equal or greater than four carbon atoms. Melting and decomposition temperatures were determined together with experimental densities, surface tensions, refractive indices, dynamic viscosities and ionic conductivities in a temperature interval ranging from (293.15 to 353.15)K. The surface properties of these fluorinated ionic liquids were discussed and several thermodynamic functions, as well as critical temperatures, were estimated. Coefficients of isobaric thermal expansion, molecular volumes and free volume effects were calculated from experimental values of density and refractive index and compared with previous data. Finally, Walden plots were used to evaluate the ionicity of the investigated ionic liquids.
Aim
To investigate hydrogen peroxide (H2O2)‐induced responsiveness in pulp cells using heme oxygenase‐1 (HO‐1) immunolabelling, Jun‐D immunolabelling to study the effects of H2O2 on odontoblastic ...differentiation and CD90+/CD73+/CD105+/CD45‐ cell counting for in vivo identification of mesenchymal stem cells in the pulp.
Methodology
The maxillary molars of 50 rats were treated with a bleaching gel (35% H2O2, 1 × 30 min) or placebo gel (control groups). At 2, 3, 7, 15 and 30 days after the treatment (n = 10), inflammation in pulp tissue was analysed by haematoxylin–eosin staining, HO‐1‐ and Jun‐D‐immunolabelled cells were counted in each third of the pulp chamber, and the number of CD90+/CD73+/CD105+/CD45‐ cells was quantified by immunofluorescence. The results were assessed using the Paired t‐test or Wilcoxon signed‐rank test (P < 0.05).
Results
Significant H2O2‐induced inflammation was noted at 2 and 3 days (P < 0.05), with tertiary dentine formation occurring from 7 days. The bleached specimens had greater HO‐1 immunolabelling in the middle and cervical thirds of the coronal pulp at 2 and 3 days, in all thirds at 7 days, and in the occlusal third at 15 days (P < 0.05), and significant nuclear Jun‐D immunolabelling in the cervical third at 2 and 3 days and in the occlusal and middle thirds at 7 days (P < 0.05). Bleached and control groups had low numbers of CD90+/CD73+/CD105+/CD45‐ cells in the pulp at all periods (P > 0.05).
Conclusions
Pulp cells responded to oxidative stress by expressing HO‐1 during the post‐bleaching inflammation phase until the beginning of the repair phase. Jun‐D expression occurred during the reduction of inflammation and the beginning of tertiary dentine production. The presence of oxidative stress did not influence the number of CD90+/CD73+/CD105+/CD45‐ cells identified in vivo in the dental pulp.
This work represents an essential step towards the understanding of the dynamics and thermodynamic characteristics of a novel family of ionic liquids, namely fluorinated ionic liquids based on the ...combination of 1-alkyl-3-methylimidazolium cations with perfluoroalkylsulfonates or perfluoroalkylcarboxylates anions. The so far scarce information about these fluids constitutes a limiting factor for their potential applications. In this work, we provide detailed evidence on the influence of hydrogenated and fluorinated alkyl chain lengths in the final characteristics of the fluorinated ionic liquids. Different properties, namely, melting point, decomposition temperature, density, dynamic viscosity, ionic conductivity and refractive index, were determined and the experimental results were discussed taking into account the influence of the length of the hydrogenated and fluorinated alkyl chains. Molecular dynamic simulations were also performed to study the nanoscale structure of these novel compounds.
We present novel results on the free base 5,10,15,20-meso-tetra(pyridyl)-21H,23H-porphyrin (H2TPyP). This molecule presents complex electronic and vibrational properties and despite the vast ...literature reporting the transitions observed in its absorption and fluorescence spectra, a more accurate interpretation has been kept elusive. In particular, we show that the molecule's Q-band develops into many electronic and vibronic transitions, whose the well-known “four orbital model” finds it difficult to reconcile. Using distinct spectroscopy techniques, we conclude that both Qx- and Qy-bands comprise, in fact, two quasi-degenerated electronic states together with their respective vibronic progressions each. The analysis of the Huang-Rhys factors and complementary time- and polarization-resolved measurements reinforce the need for the proposed Q-band multi features remodeling.
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•The asymmetric shape of Qy and Qx absorption bands of H2TPyP is discussed.•Q-band is composed of multi-electronic transitions.•Spectral derivative and deconvolution support remodeling of current description.•The vibrational modes belonging to vibronic progressions are determined.
Detecting changes in the phenological responses of herbaceous species as a function of predicted climate change is important for forecasting future scenarios for the functioning of dry tropical ...forests, especially when predicting an increase in the frequency and intensity of extreme droughts. Because of the sensitivity of plants to water availability, our study hypothesizes that if years become drier or wetter, herbaceous plants will synchronously change the onset, duration, and intensity of their vegetative phenophases.
We used a historical series of 60 years of precipitation observations for the Caatinga vegetation to define daily average of precipitation for rainy (Twet), median (Tcontrol), and dry (Tdry) years. We simulated past average daily rainfall (Twet, Tcontrol, and Tdry) while growing two herbaceous perennials and two herbaceous annuals. We monitored plant growth and measured the activity (absence or presence) and intensity of vegetative phenophases. We used circular statistical analysis to assess differences between treatments.
Our results revealed that leaf production was seasonal but relatively uniform for perennial species and highly seasonal (wet season) for annual species. Simulated dry years induced lower leaf emergence concentrated over a few months in annual species, but this effect was more strongly significant in one of the two perennial species. Both annual and perennial species can experience delayed and less intense leaf abscission during the rainy season in years with below‐average precipitation. In contrast, large voluminous rains in years with above‐average precipitation can accelerate and intensify the process of leaf renewal.
If future precipitation reductions occur, the changes in phenological response indicate that the cover of annual and perennial herbaceous species in this study will likely decrease, altering the landscape and functioning of dry tropical forests. However, the potential trade‐offs observed may help populations of these species to persist during years of severe drought in the Caatinga.
We investigate how extreme rainfall simulations impact the growth cycles of perennial and annual herbaceous species from a Brazilian dry forest.
► We report the solubility of different conventional salts in several ionic liquids. ► The solubility was initially screened using a visual detection method. ► The most promising mixtures were ...quantitatively re-measured using an ATR–FTIR.
The solubility of different conventional salts in several room-temperature ionic liquids – containing ammonium, phosphonium or imidazolium cations combined with acetate, sulfate, sulfonate, thiocyanate, chloride, tetracyano-borate, tris(pentafluoroethyl)trifluoro-phosphate, l-lactate, bis(trifluoromethylsulfonyl)imide or trifluoromethylsulfonate anions – were screened using a visual detection method. The most promising mixtures were then re-measured using an ATR–FTIR (Attenuated Total Reflection Fourier Transform Infra Red) spectroscopy technique in order to accurately and quantitatively determine the corresponding solubility at 298.15K.
The changing of the electronic and vibronic states due to the insertion of Zn(II), Cu(II), Ni(II) or Co(II) ions in the meso-tetrakis(4-pyridyl)porphyrin ring center is investigated. The combination ...of absorption, photoluminescence, Raman and infrared spectroscopies with second-derivative-based spectral deconvolution analysis reveals that the structuration of both B- and Q-bands is very sensitive to the decorating ion. Similar to free base porphyrins, metal(II) meso-tetra(4-pyridyl)porphyrins also present their Q-band constituted of multiple electronic transitions, where the central ion plays an important role in the selection of vibration modes that mediate the vibronic transitions. Our novel results will expand and reinterpret current assignments for metal(II) meso-tetra(4-pyridyl)porphyrins vibrational modes available in the literature.
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•Electronic and vibronic transitions of metal (II) TPyP are investigated.•The dependence of the molecular symmetry with the inserted ion is proved.•Spectra derivative and deconvolution support the symmetry evolution.•The vibrational modes belong to vibronic progressions are determined.•The hot luminesce of the ZnTPyP's is observed.
The mutual effects of water content and carbon black nanoparticle (CBN) concentration on the electrical resistivity and self-sensing properties of mortars are reported in this paper. Previous works ...have focused on moisture effects in CBN-based composites whose conductivity mainly came from direct contact between nanofillers. This study found very distinct behaviors when the CBN concentration was within the percolation zone. Mortars containing different moisture and CBN contents were subjected to direct current (DC) measurements, biphasic DC, and piezoresistivity tests. Effects of water content on the intrinsic capacitance of CBN-based composites were reported. A deep investigation within the percolation zone allowed the design of a promising CBN-based composite whose resistivity and sensing properties are minimally dependent on the water content, because the effects on ionic conduction due to the elimination of pore water were compensated by the effects on contacting conduction due to the elimination of water films on CBN surface. Keywords: capacitive behavior; carbon black nanoparticles; electrical resistivity; piezoresistivity; smart cement-based composites; structural health monitoring; water content.
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