Jarosite pseudomorph formation from arsenopyrite oxidation using Acidithiobacillus ferrooxidans

In this work, the oxidizing action of a native strain type A. ferrooxidans on a sulphide containing a predominance of arsenopyrite and pyrite has been evaluated. Incubation of the A. ferrooxidans strain in flasks containing 200 mL of T&K medium with the ore (particle size of 106 mu m) at pulp density 8% (w/v) at 35 degrees C on a rotary shaker at 200 rpm resulted in preferential oxidation of the arsenopyrite and the mobilization of 88% of the arsenic in 25 days. Mineralogical characterization of the residue after biooxidation was carried out with FTIR. XRD and SEM/XEDS techniques. An in situ oxidation of the arsenopyrite is suggested on the basis of the frequent appearance of jarosite pseudomorph replacing arsenopyrite, in which the transformations Fe(2+) -> Fe(3+), S(-2) -> S(+6) and As(-1) -> As(+3) -> As(+5) occur for the most part without formation of soluble intermediates, resulting in a type of jarosite that typically contains high concentrations of arsenic (type A-jarosite). However, during pyrite oxidation, dissolution of the constituent Fe and S predominates, which is evidenced by corrosion of pyrite particles with formation of pits, generating a type of jarosite with high quantities of K (type B-jarosite). Lastly, a third type of jarosite (type C-jarosite) also precipitated forming a thin film that covered the grains of pyrite principally. (C) 2010 Elsevier B.V. All rights reserved.

Alveolar process preservation at implants installed immediately into extraction sockets using deproteinized bovine bone mineral - an experimental study in dogs

Aim To evaluate the soft tissue and the dimensional changes of the alveolar bony crest at sites where deproteinized bovine bone mineral (DBBM) particles, concomitantly with the placement of a collagen membrane, were used at implants installed into sockets immediately after tooth extraction. Material and methods The pulp tissue of the mesial roots of 3P3 was removed in six Labrador dogs, and the root canals were filled. Flaps were elevated bilaterally, the premolars hemi-sectioned, and the distal roots removed. Recipient sites were prepared in the distal alveolus, and implants were placed. At the test sites, DBBM particles were placed in the residual marginal defects concomitantly with the placement of a collagen membrane. No treatment augmentation was performed at the control sites. A non-submerged healing was allowed. Impressions were obtained at baseline and at the time of sacrifice performed 4 months after surgery. The cast models obtained were analyzed using an optical system to evaluate dimensional variations. Block sections of the implant sites were obtained for histological processing and soft tissue assessments. Results After 4 months of healing, no differences in soft tissue dimensions were found between the test and control sites based on the histological assessments. The location of the soft tissue at the buccal aspect was, however, more coronal at the test compared with the control sites (1.8 +/- 0.8 and 0.9 +/- 0.8 mm, respectively). At the three-dimensional evaluation, the margin of the soft tissues at the buccal aspect appeared to be located more apically and lingually. The vertical dislocation was 1 +/- 0.6 and 2.7 +/- 0.5 mm at the test and control sites, respectively. The area of the buccal shrinkage of the alveolar crest was significantly smaller at the test sites (5.9 +/- 2.4 mm2) compared with the control sites (11.5 +/- 1.7 mm2). Conclusion The use of DBBM particles concomitantly with the application of a collagen membrane used at implants placed into sockets immediately after tooth extraction contributed to the preservation of the alveolar process.

Maternal antibody transfer to broiler progeny varies among strains and is affected by grain source and cage density

Two experiments were conducted to examine the effects of broiler breeder dietary grain source and cage density on maternal antibody (MatAb) transfer to progeny in 2 genetic strains (A and B). Broiler breeders were assigned to 16 litter floor pens and fed either corn- or wheat-based diets. Breeders were administered 4 live vaccines against Newcastle disease virus (NDV). At 23 wk of age, pullets and cocks, which reflected the full BW distribution from each treatment, were moved to a cage breeder house and placed at 1 or 2 hens/cage. Breeders were artificially inseminated at 44 wk (experiment 1) and 52 wk of age (experiment 2). Eggs were collected for 8 d, incubated, and placed in individual pedigree bags at d 19 of incubation. Blood samples from 5 chicks per treatment combination were collected at hatch in both experiments. Spleen and bursa were collected from the same chicks for histomorphometry analyses in experiment 2. In the second experiment, 12 chicks per treatment were placed in cages. Progeny were provided diets based on the same grain (corn or wheat) as their parents. Serum samples were collected at 5, 9, and 13 d of age and analyzed for anti-NDV MatAb. Data were analyzed as a 2 x 2 x 2 factorial design considering strain, dietary grain source, and cage density as main factors. Interaction effects were observed in breeders and progeny. Experiment 1 showed that strain A chicks had lower levels of MatAb when hens were housed at 2 hens/cage rather than 1 hen/cage. The MatAb levels of strain B chickens were not affected by cage density in either experiment. Experiment 2 demonstrated similar effects of cage density on MatAb levels and the area of bursa follicles for both strains. Progeny of breeders fed corn-based diets had smaller spleen white pulp only when hens were housed at 2 hens/cage compared with 1 hen/cage. The results of these experiments suggest that breeder strain and cage-density conditions affected MatAb transfer to progeny and embryo development of spleen and bursa.

Deproteinized bovine bone mineral in marginal defects at implants installed immediately into extraction sockets: an experimental study in dogs

Aim: To evaluate the influence of deproteinized bovine bone mineral (DBBM) particles concomitant with the placement of a collagen membrane on alveolar ridge preservation and on osseointegration of implants placed into alveolar sockets immediately after tooth extraction. Material and methods: The pulp tissue of the mesial roots of 3P3 was removed in six Labrador dogs and the root canals were filled. Flaps were elevated in the right side of the mandible, and the buccal and lingual alveolar bony plates were exposed. The third premolar was hemi-sectioned and the distal root was removed. A recipient site was prepared and an implant was placed lingually. After implant installation, defects of about 0.6mm wide and 3.1mm depth resulted at the buccal aspects of the implant, both at the test and at the control sites. The same surgical procedures and measurements were performed on the left side of the mandible. However, DBBM particles with a size of 0.25-1mm were placed into the remaining defect concomitant with the placement of a collagen membrane. Results: All implants were integrated into mature bone. No residual DBBM particles were detected at the test sites after 4 months of healing. Both the test and the control sites showed buccal alveolar bone resorption, 1.8 +/- 1.1 and 2.1 +/- 1mm, respectively. The most coronal bone-to-implant contact at the buccal aspect was 2 +/- 1.1 an 2.8 +/- 1.3mm, at the test and the control sites, respectively. This difference in the distance was statistically significant. Conclusion: The application of DBBM concomitant with a collagen membrane to fill the marginal defects around implants placed into the alveolus immediately after tooth extraction contributed to improved bone regeneration in the defects. However, with regard to buccal bony crest preservation, a limited contribution of DBBM particles was achieved.

Quantification of Peroxide Ion Passage in Dentin, Enamel, and Cementum After Internal Bleaching With Hydrogen Peroxide

The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 mu L of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 mu L of leuco-crystal violet and 50 mu L of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (alpha=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (p<0.01). The GC group presented a significantly lower peroxide passage than did GD and GE (p<0.01). It can be concluded that the hydrogen peroxide placed into the pulp chamber passed through the dental hard tissues, reaching the external surface and the periodontal tissue. The cementum surface was less permeable than were the dentin and enamel surfaces.

Toothache referred from auriculotemporal neuralgia: case report

P>AimTo present a 52-year-old male patient who complained of intense pain of short duration in the region of the left external ear and in the ipsilateral maxillary second molar that was relieved by blockade of the auriculotemporal nerve in the infratemporal fossa.SummaryExtra- and intraoral physical examination revealed a trigger point that reproduced the symptoms upon finger pressure in the ipsilateral auriculotemporal nerve and in the outer auricular pavilion. The patient's medical history was unremarkable. The maxillary left second molar tooth was not responsive to pulp sensitivity testing and there was no pain upon percussion or palpation of the buccal sulcus. Periapical radiographs revealed a satisfactory root filling in the maxillary left second molar. on the basis of the clinical signs and symptoms, the auriculotemporal was blocked with 0.5 mL 2% lidocaine and 0.5 mL of a suspension containing dexamethasone acetate (8 mg mL(-1)) and dexamethasone disodium sulfate (2 mg mL(-1)), with full remission of pain 6 months later. The diagnosis was auriculotemporal neuralgia.Key learning pointAuriculotemporal neuralgia should be considered as a possible cause of nonodontogenic toothache and thus included in the differential diagnoses.The blockade of the auriculotemporal nerve in the infratemporal fossa is diagnostic and therapeutic. It can be achieved with a solution of lidocaine and dexamethasone.

The induction of cytotoxicity, oxidative stress, and genotoxicity by root canal sealers in mammalian cells

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

Carrying and Effect of Granulated Baits Formulated with Entomopathogenic Fungi among Atta sexdens rubropilosa Colonies (Hymenoptera: Formicidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fiber fermentability effects on energy and macronutrient digestibility, fecal traits, postprandial metabolite responses, and colon histology of overweight cats

Considering the different potential benefits of divergent fiber ingredients, the effect of 3 fiber sources on energy and macronutrient digestibility, fermentation product formation, postprandial metabolite responses, and colon histology of overweight cats (Felis catus) fed kibble diets was compared. Twenty-four healthy adult cats were assigned in a complete randomized block design to 2 groups of 12 animals, and 3 animals from each group were fed 1 of 4 of the following kibble diets: control (CO; 11.5% dietary fiber), beet pulp (BP; 26% dietary fiber), wheat bran (WB; 24% dietary fiber), and sugarcane fiber (SF; 28% dietary fiber). Digestibility was measured by the total collection of feces. After 16 d of diet adaptation and an overnight period without food, blood glucose, cholesterol, and triglyceride postprandial responses were evaluated for 16 h after continued exposure to food. on d 20, colon biopsies of the cats were collected under general anesthesia. Fiber addition reduced food energy and nutrient digestibility. of all the fiber sources, SF had the least dietary fiber digestibility (P < 0.05), causing the largest reduction of dietary energy digestibility (P < 0.05). The greater fermentability of BP resulted in reduced fecal DM and pH, greater fecal production [g/(cat x d); as-is], and greater fecal concentration of acetate, propionate, and lactate (P < 0.05). For most fecal variables, WB was intermediate between BP and SF, and SF was similar to the control diet except for an increased fecal DM and firmer feces production for the SF diet (P < 0.05). Postprandial evaluations indicated reduced mean glucose concentration and area under the glucose curve in cats fed the SF diet (P < 0.05). Colon mucosa thickness, crypt area, lamina propria area, goblet cell area, crypt mean size, and crypt in bifurcation did not vary among the diets. According to the fiber solubility and fermentation rates, fiber sources can induce different physiological responses in cats, reduce energy digestibility, and favor glucose metabolism (SF), or improve gut health (BP).

Amino Acids on Mango Yield and Fruit Quality at Submedio Sao Francisco Region, Brazil

Farmers of the Submedio Sao Francisco Region (Brazil) have been spraying amino acids on mango trees with the objective of increasing panicle length and improving fruit retention and quality. This study, done in two experiments, tested the effect of amino acids sprayings at concentrations of 0.0%; 0.02%; 0.04% and 0.06%, on mango plants, 'Tommy Atkins', on the budding phase (panicles with 5 cm), fruit set and fruit growth (5 cm diameter). They were carried out from June to October in 2003, that is the natural period for harvest in the region, and from January to May, in 2004. There were no statistical differences in the first experiment among treatments regarding panicle length and fruit production, probably due to an appropriate management of nutrition, water and plant growth regulators, besides climatic conditions, mainly temperature and solar radiation. In the second experiment, significant increments in the panicle length of 13.37%, 11.70% and 21.4% were observed with amino acids concentrations, compared to the control. Increasing amino acids doses also enhanced the number of fruits per plant, thirty days before the harvest, in 16.17%, 45.32% and 37.38%, respectively, compared to the control, but there were no significant statistical differences. Characteristics of fruit quality during storage, as weight loss, total soluble solids, total titratable acidity and pulp firmness were not significantly affected by amino acids spraying. Changes on those variables were registered as a consequence of fruit ripening. Amino acids sprays lightly delayed the evolution of skin luminosity and Hue of pulp, but the differences could not be visually identified. The concentrations of amino acids were not efficient for improving the natural concentrations of these substances in the leaves, which could be the reason for the non significant effects on the variables analyzed.

Organic and conventional fertilisation procedures on the nitrate, antioxidants and pesticide content in parts of vegetables

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

Effects of broiler breeder genetic, diet type, and feeding program on maternal antibody transfer and development of lymphoid tissues in chicken progeny

Maternal antibody (MatAb) transfer is important for early chicken survivability. Diet composition and the amount of feed given to breeder pullets during rearing may affect the development of immunity and the transfer of MatAb to progeny, and could affect progeny performance and resistance to disease. The effects of broiler breeder nutrition and feeding management practices were evaluated for the transfer of MatAb to progeny and for spleen and bursa development at hatching in 2 genetic strains (A and B). In this experiment, the levels of MatAb against Newcastle disease virus were assessed by enzyme-linked immunosorbent assays in serum samples taken of pedigreed chicken progeny from hatching to 13 d of age. Chickens were fed corn-and wheat-based diets, as were their parents. The breeder feeding program and diet type altered the Newcastle disease virus MatAb found in progeny at hatching and affected how long these antibodies were maintained in circulation. Bursal follicle size at hatching was influenced by an interaction among all factors evaluated. Percentage of white pulp in the spleen was affected mainly by genetic strain and diet type, but responses varied according to the breeder feeding program. It was concluded that breeder feeding programs influence MatAb transfer and half-life, and may also affect the early development of lymphoid tissues.

Adubação organomineral e biofertilização líquida na produção de frutos de pinheira ( Annona squamosa L.) no submédio São Francisco, Brasil

The organic production systems based on natural processes do not allow the use of synthetic fertilizers with a high solubility, so it is required the use of technologies in accordance with the organic production legislation in order to make the technical, economical and environmental sustainable activities viable. To evaluate the effects of the usage of mineral and organic natural fertilizers, associated with liquid biofertilizers (BLE= enriched liquid biofertilizer and BF= leaf biofertilizers) on the production of the sugar apple fruit crop Annona squamosa L., replacing totally the chemical fertilizers, used by conventional farming systems, a nine year old orchard was driven in the irrigated plot n degrees 1295, irrigated project Nilo Coelho, district of Petrolina - PE. The experiment was carried out from September 2005 to February 2006. The experimental design was done through randomized blocks with eight treatments and four replications in plots of three plants each, with 96 plants in total. The treatments were the following: T(1) - plants with no fertilizer; T(2) - 60 g de N + 32 g de P(2)O(5) + 48 g de K(2)O; T(3) - 90g de N + 32 g de P(2)O(5) + 48 g de K(2)O; T(4) - 30 g de N + 32 g de P(2)O(5) + 48 g de K(2)O + 15 L de BLE + BF a 5 %; T(5) - 60g de N + 32 g de P(2)O(5) + 48 g de K(2)O + 30 L de BLE + BF a 5 %; T(6)- 90g de N + 32 g de P(2)O(5) + 48 g de K(2)O + 45 L de BLE + BF a 5 %; T(7) - 120g de N + 32 g de P(2)O(5) + 48 g de K(2)O + 60 L de BLE + BF a 5 %; T(8) - 150 g de N + 32 g de P(2)O(5) + 48 g de K(2)O + 75 L de BLE + BF a 5 % The fruit growth analyses (diameter and average length), total yield, productivity, average fruit weight, average number of fruits, fresh weight of the skin and pulp and dry weight of the fruits were used to evaluate the experiment. The results were relevant to the total production, fresh weight of the skin and dry weight of the fruits. The use of organominerals associated with liquid fertilizers increased significantly the productivity in values ranging from 10.44% (T(5) = 1.98 t ha(-1)) to 24.52 % (T(7) = 12.34 %). The treatment T(3) stood out (90g de N + 32g de P(2)O(5) + 48g de K(2)O) with a higher production than the control. The fruit weight increased in the fertilized treatments, with values increasing from treatment (T(2) = 5.26 %) to the treatment (T(7) = 12.34 %) in relation to the control. The fruit development was characterized by an average growth increase of 82 % in length and 84 % in diameter until the 56(th) day, with a sigmoidal growth pattern.

Fifteen-year Follow-up of a Conservatively Managed, Root-fractured Permanent Incisor

The purpose of this case report was to describe the successful long-term conservative management of a root-fractured permanent maxillary right central incisor in an 8-year-old patient. After the initial approach of splinting the traumatized tooth, the patient was followed on a regular basis for 15 years. Clinically, the crown of the root-fractured incisor showed no displacement or discoloration, and thermal tests suggested pulp vitality over the follow-up period. Radiographically, an increase in the diastasis was observed between the apical and coronal fragments due to both the growth of the alveolar process and the healing with interposition of hard and soft tissue between the fragments and confirmed with computed tomography scan in the 15-year follow-up appointment. (Pediatr Dent 2012;34:156-8) Received June 21, 2010 vertical bar Lost Revision August 18, 2010 vertical bar Accepted August 27, 2010

Liposomal encapsulation improves the duration of soft tissue anesthesia but does not induce pulpal anesthesia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)