An Oligosilsesquioxane Cage Functionalized with Molybdenum(II) Organometallic Fragments

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Activity of Mo(II) allylic complexes supported in MCM-41 as oxidation catalysts precursors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tissue Reaction to a Triantibiotic Paste Used for Endodontic Tissue Self-regeneration of Nonvital Immature Permanent Teeth

Introduction: The endodontic regenerative procedure (ERP), which is an alternative to calcium hydroxide induced apexification, involves the use of a triple antibiotic paste (TAP) as a dressing material. The aim of this study was to evaluate the response of rat subcutaneous tissue to implanted polyethylene tubes that were filled with TAP or calcium hydroxide. Methods: Thirty rats received 2 individual implants of polyethylene tubes filled with TAP or calcium hydroxide paste (CHP) and another empty tube as a control. Thirty additional rats received 2 individual implants consisting of polyethylene tubes filled with dressing material carriers (macrogol and propylene glycol) and a sham procedure. After 7, 15, 30, 60, and 90 days, 12 animals were euthanized, and the tubes and surrounding tissue were removed and processed for histology by using glycol methacrylate and stained with hematoxylin and eosin. The histological score ranged from 0 to 3 depending on the content of inflammatory cells; the fibrous capsule was considered thin or thick, and necrosis and calcification were recorded as present or absent. The results were analyzed using the Kruskal-Wallis test. Results: Both dressing materials induced moderate reactions at 7 and 15 days. These reactions were similar to the control (P>.05) and reduced in intensity (to mild) from day 30 onward (P>.05). The carriers did not interfere with the reaction of the dressing materials. Conclusions: TAP and CHP were biocompatible over the different experimental periods examined. (J Endod 2012;38:91-94)

Evaluation of pH and Calcium Ion Release of Calcium Hydroxide Pastes Containing Different Substances

Introduction: The objective of this study was to evaluate the pH and calcium ion release of calcium hydroxide pastes associated with different substances. Methods: Forty acrylic teeth with simulated root canals were divided into 4 groups according to the substance associated to the calcium hydroxide paste: chlorhexidine (CHX) in 2 formulations (1% solution and 2% gel), Casearia sylvestris Sw extract, and propylene glycol (control). The teeth with pastes and sealed coronal accesses were immersed in 10 mL deionized water. After 10 minutes, 24 hours, 48 hours, and 7, 15, and 30 days, the teeth were removed to another container, and the liquid was analyzed. Calcium ion release was measured by atomic absorption spectrophotometry, and pH readings were made with a pH meter. Data were analyzed statistically by analysis of variance and Tukey test (alpha = 0.05). Results: Calcium analysis revealed significant differences (P < .05) for 1% CHX solution and 2% CHX gel at 10 minutes. After 24 hours, 2% CHX gel x Control and 2% CHX gel x 1% CHX solution differed significantly (P < .05). After 48 hours, there were significant differences (P < .05) for 2% CHX gel x Control and Extract x Control. No differences (P > .05) were observed among groups in the other periods. Regarding the pH, there were significant differences (P < .05) for 2% CHX gel x Control and 2% CHX gel x 1% CHX solution after 48 hours and for 2% CHX gel x Control after 15 days. In the other periods, no differences (P > .05) were observed among groups. Conclusions: All pastes behaved similarly in terms of pH and calcium ion release in the studied periods. (J Endod 2009;35:1274-1277)

Residues of calcium hydroxide-based intracanal medication associated with different vehicles: A scanning electron microscopy evaluation

This study evaluated the presence of residues after removal of calcium hydroxide [Ca(OH)2] associated with different vehicles. Thirty single-rooted teeth were instrumented to a master apical file #25 using 2.5% NaOCl as main irrigant and 17% trisodium EDTA (ethylenediaminetetraacetic acid) as final agent irrigant. Then, the root canals were dressed with Ca(OH)2 associated with silicone oil (Group 1), 2% chlorhexidine gluconate (Group 2), or propylene glycol (Group 3). After coronal sealing, all teeth were kept in a moist environment at room temperature. After 7 days, the teeth were reopened and medicaments were removed using 5 mL of saline solution and instrumentation with master apical file followed by new irrigation with 5 mL of 2.5% NaOCl. Subsequently, teeth were split longitudinally and assessed by scanning electron microscopy. The wall cleanliness of the cervical and apical thirds of the roots were evaluated and scored by three blinded examiners. Statistical analysis was performed using KruskalWallis and Wilcoxon tests at 5% level of significance. All roots had residues of Ca(OH)2 on the canal walls. All experimental groups had similar results (P > 0.05) regardless of the third evaluated. There was significant difference between the apical and cervical thirds only in Group 3 (P < 0.05). Association of different vehicles to Ca(OH)2 does not influence the persistence of residues on the root canal walls. Microsc. Res. Tech. 2012. (C) 2012 Wiley Periodicals, Inc.

Effect of Ultrasonic Activation on pH and Calcium Released by Calcium Hydroxide Pastes in Simulated External Root Resorption

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Harmful effects of carbamazepine on the postnatal development of the rat ventral prostate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cryogenic preservation of embryos of Prochilodus lineatus (Valenciennes, 1836) (Characiforme; Prochilodontidae)

While the freezing techniques of mammal embryos have been providing promising results, the cryopreservation of teleostean eggs and embryos have remained unsuccessful up to now. Therefore, this work aimed to develop a procedure of cryogenic preservation of embryos of Prochilodus lineatus and to observe, at both structural and ultrastructural levels, the morphological alterations that took place after the application of freezing/thawing techniques. The embryos at the morula stage could not tolerate exposure to the cryoprotectants ethylene glycol monomethyl ether, propylene glycol monomethyl ether, methanol, dimethyl sulphoxide and propylene glycol, presenting 100% of mortality. Embryos at the 4- to 6-somites stage tolerated exposure to propylene glycol and dimethyl sulphoxide, and the results revealed no significant differences (alpha = 0.05) regarding survival from both treatments. None of the freezing, thawing and hydration protocols was effective on preserving embryo viability. The ultrastructural analyses of frozen and thawed embryos showed that cells from ectoderm, somites, notochord and endoderm were structurally intact, with well preserved nuclei and mitochondria. The yolk globules were able to tolerate the freezing process, but the yolk syncytial layer was unorganized, displaying an electron-dense and compacted appearance, collapsed reticules, nuclei with modified chromatin and ruptures on the plasmatic membrane at the contact zone with endoderm. It might be concluded that the procedures tested for freezing were unable to avoid the formation of intracellular ice crystals, leading to drastic morphological modifications and making P. lineatus embryos unviable.

Biodegradation of the Films of PP, PHBV and Its Blend in Soil

Films of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(propylene) (PP), PP/PHBV (4:1), blends were prepared by melt-pressing and investigated with respect to their microbial degradation in soil after 120 days. Biodegradation of the films was evaluated by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction. The biodegradation and/or bioerosion of the PP/PHBV blend was attributed to microbiological attack, with major changes occurring at the interphases of the homopolymers. The PHBV film was more strongly biodegraded in soil, decomposing completely in 30 days, while PP film presented changes in amorphous and interface phase, which affected the morphology.

Interaction between Pluronic F127 and Dioctadecyldimethylammonium Bromide (DODAB) Vesicles Studied by Differential Scanning Calorimetry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Preparation of hierarchically structured porous aluminas by a dual soft template method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Design of hierarchical porous aluminas by using one-pot synthesis and different calcination temperatures

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Multi-spectroscopic monitoring of cisplatin-derived species delivery from ureasil polyether hybrid matrix

Driven by the challenges involved in the development of new advanced materials with unusual drug delivery profiles capable of improving the therapeutic and toxicological properties of existing cancer chemotherapy, the one-pot sol-gel synthesis of flexible, transparent and insoluble urea-cross-linked polyether-siloxane hybrids has been recently developed. In this one-pot synthesis, the strong interaction between the antitumor cisplatin (CisPt) molecules and the ureasil-poly(propylene oxide) (PPO) hybrid matrix gives rise to the incorporation and release of an unknown CisPt-derived species, hindering the quantitative determination of the drug release pattern from the conventional UV-Vis absorption technique. In this article, we report the use of an original synchrotron radiation calibration method based on the combination of XAS and UV-Vis for the quantitative determination of the amount of Pt-based molecules released in water. Thanks to the combination of UV-Vis, XAS and Raman techniques, we demonstrated that both the CisPt molecules and the CisPt-derived species are loaded into an ureasil-PPO/ureasil-poly(ethylene oxide) (PEO) hybrid blend matrix. The experimentally determined molar extinction coefficient of the CisPt-derived species loaded into ureasil-PPO hybrid matrix enabled the simultaneous time-resolved monitoring of each Pt species released from this hybrid blend matrix.

Evaluation of efficacy of preservatives associated with Achillea millefolium L. extract against Bacillus subtilis

A eficácia antimicrobiana de conservantes empregados em formulações cosméticas foi avaliada usando Phenova® e Imidazolinidil uréia que inibiram o crescimento de Bacillus subtilis no extrato de Achillea millefolium L. e Nipagin®/ Nipasol® 0,2% em propilenoglicol não apresentaram efeito microbicida.

Characterization and catalytic activity of iron(III) mono(4-N-methyl pyridyl)-tris(halophenyl) porphyrins in homogeneous and heterogeneous systems

The synthesis, characterization and catalytic activity of the cationic iron porphyrins Fe[M(4-N-MePy)TDCPP]Cl-2 and Fe[M(4-N-MePy)TFPP]Cl-2 in the epoxidation of (Z)-cyclooctene by PhIO in homogeneous solution and supported on silica gel (SG), imidazole propyl gel (IPG) or SG modified with 2-(4-sulfonatophenyl)ethyl groups (SiSO3) have been accomplished. When supported on IPG, both cationic FeP bind to the support via Fe-imidazole coordination. Fe[M(4-N-MePy)TDCPP]IPG contains a mixture of low-spin bis-coordinated (FeP)-P-III and high-spin mono-coordinated (FeP)-P-III species, whereas Fe[M(4-N-MePy)TFPP]IPG only contains high-spin mono-coordinated (FeP)-P-III. These FePIPG catalysts also contain (FeP)-P-II species, whose presence was confirmed by EPR spectroscopy using NO as a paramagnetic probe. Both cationic FePs coordinate to SG through Fe-O ligation and they are present as high-spin (FeP)-P-III species. The cationic FePs supported on SiSO3- are also high-spin (FeP)-P-III species and they bind to the support via electrostatic interaction between the 4-N-methylpyridyl groups and the SO3- groups present on the matrix. In homogeneous solution, both Fe[M(4-N-MePy)TDCPP]Cl-2 and Fe[M(4-N-MePy)TFPP]Cl-2 have similar catalytic activity to Fe(TDCPP)Cl and Fe(TFPP)Cl, leading to cis-epoxycyclooctane yields of 92%. When supported on inorganic matrices,both FePs lead to epoxide yields comparable to their homogeneous analogues and their anchoring enables catalyst recovery and re-use. Recycling of Fe[M(4-N-MePy)TDCPP]SiSO3- shows that this FeP maintains its activity in a second reaction. (C) 1999 Elsevier B.V. B.V. All rights reserved.