RESUMO
The use of sulfate-reducing bacteria (SRB) in passive treatments of acidic effluents containing heavy metals has become an attractive alternative biotechnology. Treatment efficiency may be linked with the effluent conditions (pH and metal concentration) and also to the amount and nature of the organic substrate. Variations on organic substrate and sulfate ratios clearly interfere with the biological removal of this ion by mixed cultures of SRB. This study aimed to cultivate a mixed culture of SRB using different lactate concentrations at pH 7.0 in the presence of Ni, Mn and Cu. The highest sulfate removal efficiency obtained was 98 %, at a COD/sulfate ratio of 2.0. The organic acid analyses indicated an acetate accumulation as a consequence of lactate degradation. Different concentrations of metals were added to the system at neutral pH conditions. Cell proliferation and sulfate consumption in the presence of nickel (4, 20 and 50 mg l(-1)), manganese (1.5, 10 and 25 mg l(-1)) and copper (1.5, 10 and 25 mg l(-1)) were measured. The presence of metals interfered in the sulfate biological removal however the concentration of sulfide produced was high enough to remove over 90 % of the metals in the environment. The molecular characterization of the bacterial consortium based on dsrB gene sequencing indicated the presence of Desulfovibrio desulfuricans, Desulfomonas pigra and Desulfobulbus sp. The results here presented indicate that this SRB culture may be employed for mine effluent bioremediation due to its potential for removing sulfate and metals, simultaneously.
Assuntos
Ácido Láctico/metabolismo , Metais Pesados/química , Sulfatos/metabolismo , Bactérias Redutoras de Enxofre/fisiologia , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Cobre/química , Meios de Cultura/química , Ácido Láctico/química , Manganês/química , Níquel/química , Filogenia , Bactérias Redutoras de Enxofre/classificação , Bactérias Redutoras de Enxofre/crescimento & desenvolvimentoRESUMO
Understanding the factors involved in embryo production in superovulated cows is fundamentally important in order to plan a program of embryo transfer. The present study analyzed the relevance of both intrinsic and extrinsic factors related to embryo production in Nelore cows (Bos taurus indicus). We studied 884 superovulation inductions in 318 donor cows ranging from 2 to 21 years of age, on six farms located in the state of Mato Grosso do Sul, Brazil. The data were analyzed using a General Linear Model in the SAS software package. The number and quality of the recovered embryos were not affected (P > 0.05) by continuous superovulation treatment (i.e., inducing superovulation up to six times), by the source of the hormones used (Pluset tm, Super-ov tm, Ovagen tm, FSH-p tm), by the hormone dosage (50, 75 or 100%), or by synchronization of follicular wave emergence with progestogens. Donor age negatively affected the number and quality of the embryos. Senile (>14 years) cows produced, on average, 5.0 ± 0.2 fewer total embryos and 3.0 ± 0.1 fewer transferable embryos than young cows (P < 0.001). The farm management increased the number of transferable embryos by 2.0 ± 0.4. We conclude that farm management and donor age are the main factors that should be considered when implementing a program of embryo transfer in Nelore cows submitted to superovulation treatment.
Assuntos
Animais , Embrião de Mamíferos/citologia , Fertilização/fisiologia , Óvulo/citologia , BovinosRESUMO
Understanding the factors involved in embryo production in superovulated cows is fundamentally important in order to plan a program of embryo transfer. The present study analyzed the relevance of both intrinsic and extrinsic factors related to embryo production in Nelore cows (Bos taurus indicus). We studied 884 superovulation inductions in 318 donor cows ranging from 2 to 21 years of age, on six farms located in the state of Mato Grosso do Sul, Brazil. The data were analyzed using a General Linear Model in the SAS software package. The number and quality of the recovered embryos were not affected (P > 0.05) by continuous superovulation treatment (i.e., inducing superovulation up to six times), by the source of the hormones used (Pluset tm, Super-ov tm, Ovagen tm, FSH-p tm), by the hormone dosage (50, 75 or 100%), or by synchronization of follicular wave emergence with progestogens. Donor age negatively affected the number and quality of the embryos. Senile (>14 years) cows produced, on average, 5.0 ± 0.2 fewer total embryos and 3.0 ± 0.1 fewer transferable embryos than young cows (P < 0.001). The farm management increased the number of transferable embryos by 2.0 ± 0.4. We conclude that farm management and donor age are the main factors that should be considered when implementing a program of embryo transfer in Nelore cows submitted to superovulation treatment.(AU)
Assuntos
Animais , Embrião de Mamíferos/citologia , Óvulo/citologia , Fertilização/fisiologia , BovinosRESUMO
Fibre Bragg grating is used to determine resin-based composite shrinkage. Two composite resins (Freedom from SDI and Z100 from 3M) were tested to determine the polymerization contraction behaviour. Each sample of resin was prepared with an embedded fibre Bragg grating. A LED activation unit with wavelength from 430 nm to 470 nm (Dabi Atlante) was used for resin polymerization. The wavelength position of the peak in the optical reflection spectra of the sensor was measured. The wavelength shift was related to the shrinkage deformation of the samples. Temperature and strain evolution during the curing phase of the material was monitored. The shrinkage in the longitudinal direction was 0.15 +/- 0.02% for resin Z100 (3M) and 0.06+/-0.01% for Freedom (SDI); two-thirds of shrinkage occurred after the first 50 s of illumination.
Assuntos
Resinas Compostas/química , Tecnologia de Fibra Óptica , Tecnologia Odontológica/métodos , Análise do Estresse Dentário , Tecnologia Odontológica/instrumentaçãoAssuntos
Humanos , Masculino , Feminino , Cumarínicos/uso terapêutico , Diosmina , Insuficiência Venosa , Insuficiência VenosaRESUMO
We investigated kidney and lung alterations caused by intercellular adhesion molecule type 1 (ICAM-1) blockade after ischemia and reperfusion of hind limb skeletal muscles. Rats were submitted to ligature of the infrarenal aorta for 6 h. The animals were randomized into three groups of 6 rats each: group I, sacrificed after ischemia; group II, reperfusion for 24 h, and group III, reperfusion for 24 h after receiving monoclonal anti-ICAM-1 antibodies. At the end of the experiment, blood samples were collected for creatinine, lactate dehydrogenase, creatine phosphokinase, potassium, pH and leukocyte counts. Samples were taken from the muscles of the hind limbs and from the kidneys and lungs for histological analysis and measurement of the neutrophil infiltrate by myeloperoxidase staining. The groups did not differ significantly with regard to the laboratory tests. There were no major histological alterations in the kidneys. An intense neutrophil infiltrate in the lungs, similar in all groups, was detected. Myeloperoxidase determination showed that after reperfusion there was significantly less retention of polymorphonuclear neutrophils in the muscles (352 ± 70 vs 1451 ± 235 I 10² neutrophils/mg; P<0.01) and in the kidneys (526 ± 89 vs 852 ± 73 I 10² neutrophils/mg; P<0.01) of the animals that received anti-ICAM-1 before perfusion compared to the group that did not. The use of anti-ICAM-1 antibodies in this experimental model minimized neutrophil influx, thus reducing the inflammatory process, in the muscles and kidneys after ischemia and reperfusion of the hind limbs
Assuntos
Animais , Ratos , Molécula 1 de Adesão Intercelular , Isquemia , Rim , Pulmão , Músculo Esquelético , Traumatismo por Reperfusão , Anticorpos Monoclonais , Adesão Celular , Membro Posterior , Molécula 1 de Adesão Intercelular , Isquemia , Rim , Pulmão , Músculo Esquelético , Neutrófilos , Peroxidase , Ratos Wistar , Traumatismo por ReperfusãoRESUMO
We investigated kidney and lung alterations caused by intercellular adhesion molecule type 1 (ICAM-1) blockade after ischemia and reperfusion of hind limb skeletal muscles. Rats were submitted to ligature of the infrarenal aorta for 6 h. The animals were randomized into three groups of 6 rats each: group I, sacrificed after ischemia; group II, reperfusion for 24 h, and group III, reperfusion for 24 h after receiving monoclonal anti-ICAM-1 antibodies. At the end of the experiment, blood samples were collected for creatinine, lactate dehydrogenase, creatine phosphokinase, potassium, pH and leukocyte counts. Samples were taken from the muscles of the hind limbs and from the kidneys and lungs for histological analysis and measurement of the neutrophil infiltrate by myeloperoxidase staining. The groups did not differ significantly with regard to the laboratory tests. There were no major histological alterations in the kidneys. An intense neutrophil infiltrate in the lungs, similar in all groups, was detected. Myeloperoxidase determination showed that after reperfusion there was significantly less retention of polymorphonuclear neutrophils in the muscles (352 +/- 70 vs 1451 +/- 235 x 10(2) neutrophils/mg; P<0.01) and in the kidneys (526 +/- 89 vs 852 +/- 73 10(2) neutrophils/mg; P<0.01) of the animals that received anti-ICAM-1 before perfusion compared to the group that did not. The use of anti-ICAM-1 antibodies in this experimental model minimized neutrophil influx, thus reducing the inflammatory process, in the muscles and kidneys after ischemia and reperfusion of the hind limbs.