Sulfide toxicity kinetics of a uasb reactor

The effect of sulfide toxicity on kinetic parameters of anaerobic organic matter removal in a UASB (up-flow anaerobic sludge blanket) reactor is presented. Two lab-scale UASB reactors (10.5 L) were operated continuously during 12 months. The reactors were fed with synthetic wastes prepared daily using glucose, ammonium acetate, methanol and nutrient solution. One of the reactors also received increasing concentrations of sodium sulfide. For both reactors, the flow rate of 16 L.d-1 was held constant throughout the experiment, corresponding to a hydraulic retention time of 15.6 hours. The classic model for non-competitive sulfide inhibition was applied to the experimental data for determining the overall kinetic parameter of specific substrate utilization (q) and the sulfide inhibition coefficient (Ki). The application of the kinetic parameters determined allows prediction of methanogenesis inhibition and thus the adoption of operating parameters to minimize sulfide toxicity in UASB reactors

Study of the urban evolution of Brasilia with the use of LANDSAT data

The urban growth of Brasilia within the last ten years is analyzed with special emphasis on the utilization of remote sensing orbital data and automatic image processing. The urban spatial structure and the monitoring of its temporal changes were focused in a whole and dynamic way by the utilization of MSS-LANDSAT images for June 1973, 1978 and 1983. In order to aid data interpretation, a registration algorithm implemented at the Interactive Multispectral Image Analysis System (IMAGE-100) was utilized aiming at the overlap of multitemporal images. The utilization of suitable digital filters, combined with the images overlap, allowed a rapid identification of areas of possible urban growth and oriented the field work. The results obtained permitted an evaluation of the urban growth of Brasilia, taking as reference the proposed stated for the construction of the city

A new emerging oral infection: Raoultella planticola in a boy with haematological malignancy

BACKGROUND: Oral mucositis is a common complication in pediatric cancer patients, affecting up to 80% of children. Due to neutropenia and disruption of the mucosal barrier, chemotherapy-induced oral mucositis is often complicated by super-infections. CASE REPORT: A 16-years old male with stage 3 Burkitt's lymphoma developed chemotherapy induced oral mucositis grade 3 (according to WHO scale). Ulcers were quickly growing (reaching a maximum diameter of 3 cm) and became greyish in colour, resulting in dysphagia and pain. A swab of the lesions was taken and microbiological tests were performed. The sample grew for Raoultella planticola, an encapsulated Gram-negative bacterium whose full pathogenic potential still needs to be defined. TREATMENT: The patient received antibiotic combination therapy with Amikacin and Ceftazidime for 8 days. Complete healing of the lesions and resolution of the symptoms were reached and he completed his antineoplastic therapy without further complications. FOLLOW-UP: Twelve months after the infection, he is alive and well, with no oral complaints. CONCLUSION: This is the first report of a Raoultella planticola infection in a patient with chemotherapy induced oral mucositis. This type of infection must be added to the list of organisms to be considered when caring for these patients

Atropisomerism in Hindered Naphthyl Sulfoxides: Structure, Stereodynamics, and Chiral Resolution.

Barriers for the EZ interconversion of atropisomers of 1-naphthyl sulfoxides (ArSOR) having a methyl group at position 2 of the naphthalene moiety were measured by variable-temperature NMR. Their values were found to cover the range 10.6-18.4 kcal mol-1, the extreme values corresponding to derivatives 1 (R = Me) and 4 (R = Bu(t)), respectively. NOE and LIS measurements indicated that the Z atropisomer is more stable than the E but that the absence of the methyl group at position 2 of the naphthalene moiety reverses this trend, rendering E more stable than Z. Solid-state NMR and X-ray diffraction of 4 established that only the more stable atropisomer (Z) is present in the crystalline state. Molecular mechanics calculations suggest that the Z,E interconversion process might occur by a rotation pathway having an opposite direction in the case of the more hindered derivatives 3 and 4 (R = Pr(i) and Bu(t), respectively) with respect to the less hindered 1 and 2 (R = Me and Et, respectively). The enantiomers, which are due to the presence of the asymmetric sulfur atom, were resolved on a chiral stationary phase (DACH-DNB) having an SS configuration. Asymmetric oxidation reactions were employed to assign the absolute R configuration to the more retained enantiomers of alkyl aryl sulfoxides. The opposite trend (S being retained longer) was observed for diaryl sulfoxides such as 5 (R = Ph). In the case of the derivative with the largest interconversion barrier, sulfoxide 4, it was also possible to resolve (at -35-degrees-C) the two enantiomeric forms and their associated atropisomers. The use of on-line CD detection and the knowledge of the NMR assignments allowed us to unambiguously assign the elution order of the four species as ES, ER, ZS, ZR

Effect of ammonia load on efficiency of nitrogen removal in an SBBR with liquid-phase circulation

The removal of biological nitrogen from a synthetic wastewater with different ammonium nitrogen concentrations (50 and 100 mgN-NH4+/L) by a nitrification and denitrification process using a sequencing batch biofilm reactor (SBBR) with liquid-phase circulation was studied. The system with a total working volume of 4.6 L (3.7 L in the reactor and 0.9 L in the reservoir) treated 2.1 L of synthetic wastewater in 12-h cycles. As inoculum two types of biomass were used: an anaerobic/anoxic one from an up-flow anaerobic sludge blanket reactor (UASB) and an aerobic one from a prolonged aeration activated sludge system. The system, maintained at 30 ± 1 ºC, operated in batch mode followed by fed-batch mode and was aerated intermittently. During fed-batch operation the reactor was fed with an external carbon source as electron donor in the denitrifying step and with no aeration. When the reactor was fed with 50 mgN-NH4+/L, efficiencies of removal of ammonium nitrogen and total nitrogen from the effluent were 93.8 and 72.2%, respectively, and nitrite, nitrate and organic nitrogen concentrations were 0.07, 6.4 and 0.5 mg/L, respectively. On the other hand, when the influent ammonium nitrogen concentration was 100 mgN-NH4+/L, residual nitrite and nitrate were 0.17 and 20.4, respectively, and no N-Org was found in the effluent. It should be mentioned that residual nitrate remained unaltered at the different C/N ratios used. Consequently, efficiency of total nitrogen removal was reduced to 66.7%, despite efficiency of ammonium nitrogen removal exceeding 90%. These results show the potential of the proposed system in removing ammonium nitrogen from liquid effluents with a moderate ammonium nitrogen concentration.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Dynamic instance generation for few-shot handwritten document layout segmentation (short paper)

Historical handwritten document analysis is an important activity to retrieve information about our past. Given that this type of process is slow and time-consuming, the humanities community is searching for new techniques that could aid them in this activity. Document layout analysis is a branch of machine learning that aims to extract semantic informations from digitised documents. Here we propose a new framework for handwritten document layout analysis that differentiates from the current state-of-the-art by the fact that it features few-shot learning, thus allowing for good results with little manually labelled data and the dynamic instance generation process. Our results were obtained using the DIVA - HisDB dataset

Rare jaw bone tumor: The importance of multidisciplinary management and minimally invasive treatment

Objective: The aim of this study was to present a mini review of oral Cementoblastoma and to report a particular case of this tumor. The Cementoblastoma is a rare benign lesion that represents less than 1-6% of all odontogenic tumors. Cementoblastoma, in the current WHO classification of odontogenic tumors, falls under the category of mesenchymal tumors (WHO 2017) and it is characterized by the proliferation of cementum-like tissue and, in all cases, tends to be associated with an erupting permanent tooth, most often the first molar. Case Presentation: A 15-year-old female presented a great Cementoblastoma with cortical expansion that affected the left mandibular body, extending from the canine to the first premolar (size 28x24 mm) and involving the mandibular canal. Surgery was performed under general anesthesia with total excision of the lesion, which was then sent for histological analysis. Due to the high risk of nerve injuries and the extreme fragility of the remaining bone after surgery, which required plates and intermaxillary blockage, the surgical site was regenerated with an iliac crest graft together with autologous and synthetic bone. Results: For the mini-review, 107 articles were found, but only 26 were selected. The patient was monitored for 12 months after surgery; a perfect healing was reported without complications, and she showed no signs of recurrence. Conclusions: This case report emphasizes the usefulness of clinical choices in a rare case of cementoblastoma of great size in a very young patient. In this condition, finding the most effective eradicative and reconstructive treatment, following the last published protocols, could achieve optimal clinical and psychological patient outcomes

Kinetic modeling and microbial assessment by fluorescent in situ hybridization in anaerobic sequencing batch biofilm reactors treating sulfate-rich wastewater

This paper reports the results of applying anaerobic sequencing batch biofilm reactors (AnSBBR) for treating sulfate-rich wastewater. The reactor was filled with polyurethane foam matrices or with eucalyptus charcoal, used as the support for biomass attachment. Synthetic wastewater was prepared with two ratios between chemical oxygen demand (COD) and sulfate concentration (COD/SO4(2-)) of 0.4 and 3.2. For a COD/SO4(2-) ratio of 3.2, the AnSBBR performance was influenced by the support material used; the average levels of organic matter removal were 67% and 81% in the reactors filled with polyurethane foam and charcoal, respectively, and both support materials were associated with similar levels of sulfate reduction (above 90%). In both reactors, sulfate-reducing bacteria (SRB) represented more than 65% of the bacterial community. The kinetic model indicated equilibrium between complete- and incomplete-oxidizing SRB in the reactor filled with polyurethane foam and predominantly incomplete-oxidizing SRB in the reactor filled with charcoal. Methanogenic activity seems to have been the determining factor to explain the better performance of the reactor filled with charcoal to remove organic matter at a COD/SO4(2-) ratio of 3.2. For a COD/SO4(2-) ratio of 0.4, low values of sulfate reduction (around 32%) and low reaction rates were observed as a result of the small SRB population (about 20% of the bacterial community). Although the support material did not affect overall performance for this condition, different degradation pathways were observed; incomplete oxidation of organic matter by SRB was the main kinetic pathway and methanogenesis was negligible in both reactors.This work was funded by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and the Financiadora de Estudos e Projetos (FINEP), Brazil. The authors acknowledge the grants received from FAPESP and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazi