105 research outputs found

    In Vivo Comparison of 23-and 25-Gauge Sutureless Vitrectomy Incision Architecture Using Spectral Domain Optical Coherence Tomography

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    Purpose. To investigate the in vivo incision architecture using spectral domain optical coherence tomography (SD-OCT) in 23-gauge and 25-gauge transconjunctival sutureless pars plana vitrectomy (TSPPV). Methods. A prospective observational study of 22 eyes of 22 patients that underwent three-port 25-gauge (10 eyes) or 23-gauge (12 eyes) TSPPV was performed. the three sclerotomies sites in each eye were analyzed by Corneal Adapter Model (CAM) RTVue SD-OCT (Optovue Inc., Fremont, CA, USA) with wound cross-section images (longitudinal and transversal) on days 1, 7, and 30 postoperatively. Transversal and longitudinal length, location, angle between the conjunctival surface tangent and the incision plane, and architecture deformations were evaluated. Results. All patients (22 eyes) completed the study and surgeries lasted less than 60 minutes. All wounds were obliquely performed, 23-gauge mean angle was 23 +/- 5 degrees, and 25-gauge angule was 21 +/- 4 degrees. Twenty-three-gauge sclerotomy transversal mean length was 1122 +/- 242 mu m and 25-gauge transversal sclerotomy mean length was 977 +/- 174 mu m; 23-gauge longitudinal mean length was 363 +/- 42 mu m and 25-gauge longitudinal sclerotomy mean length was 234 +/- 19 mu m; 23-gauge open wound thickness mean was 61 +/- 28 mu m and 25-gauge open wound thickness mean was 22 +/- 6 mu m. All results were statistically significant (P < 0.05). No vitreous incarceration or silicone oil residue was observed in incision sites with both gauges. Conclusions. the 23-gauge and 25-gauge architectural wound constructions were well visualized using CAM SD-OCT. Statistical differences between the two gauges were observed throughout the study period.Teixeira Oftalmol, BR-70392901 Brasilia, DF, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilUniv Catolica Brasilia, Dept Ophthalmol, Brasilia, DF, BrazilUniv Montreal, Dept Ophthalmol, Hop Maisonneuve Rosemont, Montreal, PQ, CanadaPontificia Univ Catolica Rio de Janeiro, Dept Ophthalmol, Rio de Janeiro, RJ, BrazilUniv Illinois, Dept Ophthalmol, Chicago, IL 60680 USAUniversidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilWeb of Scienc

    Optimization of biomass pretreatments using fractional factorial experimental design

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOPretreatments are one of the main bottlenecks for the lignocellulose conversion process and the search for cheaper and effective pretreatment methodologies for each biomass is a complex but fundamental task. Here, we used a 2ν5−1 fractional factorial des11FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2016/13602-72016/10955-62016/05636-

    Extraction of rice bran oil using supercritical CO2 combined with ultrasound

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    CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORRice bran oil (RBO) contains oryzanol and tocopherols. Its recovery was performed using conventional techniques with toxic solvents that leave residues in the final product. Supercritical fluid extraction (SFE) has been used, obtaining high global yields352785794CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIOR552229/2011-32013/02203-6sem informaçã

    Optimization of biomass pretreatments using fractional factorial experimental design

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    Background: Pretreatments are one of the main bottlenecks for the lignocellulose conversion process and the search for cheaper and effective pretreatment methodologies for each biomass is a complex but fundamental task. Here, we used a 2ν5-1 fractional factorial design (FFD) to optimize five pretreatment variables: milling time, temperature, double treatment, chemical concentration, and pretreatment time in acid-alkali (EA) and acid-organosolv (EO) pretreatments, applied to elephant grass leaves. Results: FFD allowed optimization of the pretreatment conditions using a reduced number of experiments and allowed the identification of secondary interactions between the factors. FFD showed that the temperature can be kept at its lower level and that the first acid step can be eliminated in both pretreatments, without significant losses to enzymatic hydrolysis. EA resulted in the highest release of reducing sugars (maximum of 205 mg/g substrate in comparison to 152 mg/g in EO and 40 mg/g in the untreated sample), using the following conditions in the alkali step: [NaOH] = 4.5% w/v; 85 °C and 100 min after ball milling the sample. The factors statistically significant (P < 0.05) in EA pretreatment were NaOH concentration, which contributes to improved hydrolysis by lignin and silica removal, and the milling time, which has a mechanical effect. For EO samples, the statistically significant factors to improved hydrolysis were ethanol and catalyst concentrations, which are both correlated to higher cellulose amounts in the pretreated substrates. The catalyst is also correlated to lignin removal. The detailed characterization of the main hemicellulosic sugars in the solids after pretreatments revealed their distinct recalcitrance: glucose was typically more recalcitrant than xylose and arabinose, which could be almost completely removed under specific pretreatments. In EA samples, the removal of hemicellulose derivatives was very dependent on the acid step, especially arabinose removal. Conclusion: The results presented herewith contribute to the development of more efficient and viable pretreatments to produce cellulosic ethanol from grass biomasses, saving time, costs and energy. They also facilitate the design of enzymatic cocktails and a more appropriate use of the sugars contained in the pretreatment liquors, by establishing the key recalcitrant polymers in the solids resulting from each processing step

    Diffuse decreased gray matter in patients with idiopathic craniocervical dystonia: a voxel-based morphometry study

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Background: Recent studies have addressed the role of structures other than the basal ganglia in the pathophysiology of craniocervical dystonia (CCD). Neuroimaging studies have attempted to identify structural abnormalities in CCD but a clear pattern of alteration has not been established. We performed whole-brain evaluation using voxel-based morphometry (VBM) to identify patterns of gray matter (GM) changes in CCD. Methods: We compared 27 patients with CCD matched in age and gender to 54 healthy controls. VBM was used to compare GM volumes. We created a two-sample t-test corrected for subjects' age, and we tested with a level of significance of p < 0.001 and false discovery rate (FDR) correction (p < 0.05). Results: Voxel-based morphometry demonstrated significant reductions of GM using p < 0.001 in the cerebellar vermis IV/V, bilaterally in the superior frontal gyrus, precuneus, anterior cingulate and paracingulate, insular cortex, lingual gyrus, and calcarine fissure; in the left hemisphere in the supplementary motor area, inferior frontal gyrus, inferior parietal gyrus, temporal pole, supramarginal gyrus, rolandic operculum, hippocampus, middle occipital gyrus, cerebellar lobules IV/V, superior, and middle temporal gyri; in the right hemisphere, the middle cingulate and precentral gyrus. Our study did not report any significant result using the FDR correction. We also detected correlations between GM volume and age, disease duration, duration of botulinum toxin treatment, and the Marsden-Fahn dystonia scale scores. Conclusion: We detected large clusters of GM changes chiefly in structures primarily involved in sensorimotor integration, motor planning, visuospatial function, and emotional processing.Recent studies have addressed the role of structures other than the basal ganglia in the pathophysiology of craniocervical dystonia (CCD). Neuroimaging studies have attempted to identify structural abnormalities in CCD but a clear pattern of alteration ha5FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2010/11085-9]2010/11085-

    Effects of pretreatment on morphology, chemical composition and enzymatic digestibility of eucalyptus bark: a potentially valuable source of fermentable sugars for biofuel production – part 1

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    Abstract\ud \ud \ud \ud Background\ud \ud In recent years, the growing demand for biofuels has encouraged the search for different sources of underutilized lignocellulosic feedstocks that are available in sufficient abundance to be used for sustainable biofuel production. Much attention has been focused on biomass from grass. However, large amounts of timber residues such as eucalyptus bark are available and represent a potential source for conversion to bioethanol. In the present paper, we investigate the effects of a delignification process with increasing sodium hydroxide concentrations, preceded or not by diluted acid, on the bark of two eucalyptus clones: Eucalyptus grandis (EG) and the hybrid, E. grandis x urophylla (HGU). The enzymatic digestibility and total cellulose conversion were measured, along with the effect on the composition of the solid and the liquor fractions. Barks were also assessed using Fourier-transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance (NMR), X-Ray diffraction, and scanning electron microscopy (SEM).\ud \ud \ud \ud Results\ud \ud Compositional analysis revealed an increase in the cellulose content, reaching around 81% and 76% of glucose for HGU and EG, respectively, using a two-step treatment with HCl 1%, followed by 4% NaOH. Lignin removal was 84% (HGU) and 79% (EG), while the hemicellulose removal was 95% and 97% for HGU and EG, respectively. However, when we applied a one-step treatment, with 4% NaOH, higher hydrolysis efficiencies were found after 48 h for both clones, reaching almost 100% for HGU and 80% for EG, in spite of the lower lignin and hemicellulose removal. Total cellulose conversion increased from 5% and 7% to around 65% for HGU and 59% for EG. NMR and FTIR provided important insight into the lignin and hemicellulose removal and SEM studies shed light on the cell-wall unstructuring after pretreatment and lignin migration and precipitation on the fibers surface, which explain the different hydrolysis rates found for the clones.\ud \ud \ud \ud Conclusion\ud \ud Our results show that the single step alkaline pretreatment improves the enzymatic digestibility of Eucalyptus bark. Furthermore, the chemical and physical methods combined in this study provide a better comprehension of the pretreatment effects on cell-wall and the factors that influence enzymatic digestibility of this forest residue.The authors are grateful to FAPESP and CNPq for the financial support for this work via grants # 2010/11135-6; 2009/18354-8; 2010/08370-3; 2008/ 56255-9 and 2010/52362-5 (FAPESP); grants # 159341/2011-6; 482166/ 2010-0 and 490022/2009-0 (CNPq), Projeto INCT do Bioetanol (CNPq/ FAPESP), to USP for the financial via NAP Centro de Instrumentação para Estudos Avançados de Materiais Nanoestruturados e Biossistemas and NAP de Bioenergia e Sustentabilidade, and European Community’s Seventh Framework Programme SUNLIBB (FP7/2007-2013) under the grant agreement n° 251132. We are also grateful to Valeria Gazda for the help with furfural and 5-HMF chromatographic analysis and Caragh Whitehead for the paper review. The electron microscopy work has been performed on the microscopes JSM-5900LV and Quanta 650-FEG at LME/LNNano/ CNPEM, Campinas

    Effects of pretreatment on morphology, chemical composition and enzymatic digestibility of eucalyptus bark: a potentially valuable source of fermentable sugars for biofuel production - part 1

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    Background: In recent years, the growing demand for biofuels has encouraged the search for different sources of underutilized lignocellulosic feedstocks that are available in sufficient abundance to be used for sustainable biofuel production. Much attention has been focused on biomass fromgrass. However, large amounts of timber residues such as eucalyptus bark are available and represent a potential source for conversion to bioethanol. In the present paper, we investigate the effects of a delignification process with increasing sodium hydroxide concentrations, preceded or not by diluted acid, on the bark of two eucalyptus clones: Eucalyptus grandis (EG) and the hybrid, E. grandis x urophylla (HGU). The enzymatic digestibility and total cellulose conversion were measured, along with the effect on the composition of the solid and the liquor fractions. Barks were also assessed using Fourier-transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance (NMR), X-Ray diffraction, and scanning electron microscopy (SEM). Results: Compositional analysis revealed an increase in the cellulose content, reaching around 81% and 76% of glucose for HGU and EG, respectively, using a two-step treatment with HCl 1%, followed by 4% NaOH. Lignin removal was 84% (HGU) and 79% (EG), while the hemicellulose removal was 95% and 97% for HGU and EG, respectively. However, when we applied a one-step treatment, with 4% NaOH, higher hydrolysis efficiencies were found after 48 h for both clones, reaching almost 100% for HGU and 80% for EG, in spite of the lower lignin and hemicellulose removal. Total cellulose conversion increased from 5% and 7% to around 65% for HGU and 59% for EG. NMR and FTIR provided important insight into the lignin and hemicellulose removal and SEM studies shed light on the cell-wall unstructuring after pretreatment and lignin migration and precipitation on the fibers surface, which explain the different hydrolysis rates found for the clones. Conclusion: Our results show that the single step alkaline pretreatment improves the enzymatic digestibility of Eucalyptus bark. Furthermore, the chemical and physical methods combined in this study provide a better comprehension of the pretreatment effects on cell-wall and the factors that influence enzymatic digestibility of this forest residue.FAPESP (10/11135-6, 09/18354-8, 10/08370-3, 08/56255-9, 10/52362-5)CNPq (159341/2011-6, 482166/2010-0, 490022/2009-0)European Community’s Seventh Framework Programme SUNLIBB (FP7/2007-2013)INCT do BioetanolNúcleo de Apoio à Pesquisa em Bioenergia e Sustentabilidade (NAPBS)Centro de Instrumentação para Estudos Avançados de Materiais Nanoestruturados e Biossistemas (CIEA_MNB

    Natural rubber-clay nanocomposites: mechanical and structural properties

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    International audienceThe mechanical properties of non-vulcanized natural rubber and dialyzed natural rubber-clay nanocomposites have been studied by uniaxial deformations to evaluate the reinforcement efficiency of the clay. We show that while non-rubber molecules contribute to auto-reinforcement, removal of these molecules improves significantly the performance of clay as reinforcement agent. These mechanical properties are discussed in relation to morphological aspects of the clay characterized by TEM and SANS. The nanocomposites prepared by "latex-mixing" with aqueous dispersions of clay are found to contain completely exfoliated clay lamellae in coexistence with tactoids. Improved mechanical properties of the nanocomposites can be modeled by the high aspect ratio of exfoliated clay platelets coupled with immobilized rubber matrix. Interestingly, presence of tactoids does not appear to compromise the excellent reinforcement properties of the exfoliated platelets. At high deformations, strain-induced alignment of the clay exhibits anisotropic scattering, with anisotropy increasing with clay concentration and stretching

    Identification of metabolic pathways influenced by the G-protein coupled receptors GprB and GprD in Aspergillus nidulans

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    Heterotrimeric G-protein-mediated signaling pathways play a pivotal role in transmembrane signaling in eukaryotes. Our main aim was to identify signaling pathways regulated by A. nidulans GprB and GprD G-protein coupled receptors (GPCRs). When these two null mutant strains were compared to the wild-type strain, the DeltagprB mutant showed an increased protein kinase A (PKA) activity while growing in glucose 1% and during starvation. In contrast, the DeltagprD has a much lower PKA activity upon starvation. Transcriptomics and (1)H NMR-based metabolomics were performed on two single null mutants grown on glucose. We noted modulation in the expression of 11 secondary metabolism gene clusters when the DeltagprB and DeltagprD mutant strains were grown in 1% glucose. Several members of the sterigmatocystin-aflatoxin gene cluster presented down-regulation in both mutant strains. The genes of the NR-PKS monodictyphenone biosynthesis cluster had overall increased mRNA accumulation in DeltagprB, while in the DeltagprD mutant strain the genes had decreased mRNA accumulation. Principal component analysis of the metabolomic data demonstrated that there was a significant metabolite shift in the DeltagprD strain. The (1)H NMR analysis revealed significant expression of essential amino acids with elevated levels in the DeltagprD strain, compared to the wild-type and DeltagprB strains. With the results, we demonstrated the differential expression of a variety of genes related mainly to secondary metabolism, sexual development, stress signaling, and amino acid metabolism. We propose that the absence of GPCRs triggered stress responses at the genetic level. The data suggested an intimate relationship among different G-protein coupled receptors, fine-tune regulation of secondary and amino acid metabolisms, and fungal development
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