24 resultados para Steam injection.
Resumo:
Purpose: To evaluate the effect of a single intravitreal bevacizumab injection on visual acuity, contrast sensitivity and optical coherence tomography-measured central macular thickness in eyes with macular edema from branch retinal vein occlusion. Methods: Seventeen eyes of 17 patients with macular edema from unilateral branch retinal vein occlusion were treated with a single bevacizumab injection. Patients were submitted to a complete evaluation including best corrected visual acuity, contrast sensitivity and optical coherence tomography measurements before treatment and one and three months after injection. Visual acuity, contrast sensitivity and optical coherence tomography measurements were compared to baseline values. Results: Mean visual acuity measurement improved from 0.77 logMAR at baseline to 0.613 logMAR one month after injection (P=0.0001) but worsened to 0.75 logMAR after three months. Contrast sensitivity test demonstrated significant improvement at spatial frequencies of 3, 6, 12 and 18 cycles/degree one month after injection and at the spatial frequency of 12 cycles/degree three months after treatment. Mean +/- standard deviation baseline central macular thickness (552 +/- 150 mu m) reduced significantly one month (322 +/- 127 mu m, P=0.0001) and three months (439 perpendicular to 179 mu m, P=0.01) after treatment. Conclusions: Bevacizumab injection improves visual acuity and contrast sensitivity and reduces central macular thickness one month after treatment. Visual acuity returns to baseline levels at the 3-month follow-up, but some beneficial effect of the treatment is still present at that time, as evidenced by optical coherence tomography-measured central macular thickness and contrast sensitivity measurements.
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Purpose: To investigate macular thickness and visual acuity changes after 1 intravitreal injection of 0.5-mg ranibizumab during phacoemulsification cataract surgery in eyes with diabetic macular edema refractory to laser treatment. Methods: Eleven eyes of 11 patients with diabetic macular edema refractory to modified Early Treatment Diabetic Retinopathy Study laser therapy received intravitreal during phacoemulsification cataract surgery. Comprehensive ophthalmic evaluation was performed preoperatively and at 1, 4, 8 +/- 1, and 12 +/- 2 weeks postoperatively. Main outcome measures included central subfield thickness and best-corrected Early Treatment Diabetic Retinopathy Study visual acuity. Results: Eleven patients completed the 12-week study visit. Mean central subfield thickness (+/- SEM) was 399.82 +/- 29.50 mu m at baseline and did not change significantly at any postoperative study visit (P > 0.05). Mean (+/- SEM) best-corrected Early Treatment Diabetic Retinopathy Study visual acuity was 0.95 +/- 0.13 logarithm of the minimum angle of resolution (20/200) at baseline and was significantly improved at Weeks 1 (0.38 +/- 0.13), 4 (0.38 +/- 0.11), 8 (0.35 +/- 0.08), and 12 (0.46 +/- 0.12) after treatment (P < 0.05). Conclusion: In this case series of patients with diabetic macular edema refractory to laser therapy, intravitreal ranibizumab administered during cataract surgery was associated with no significant change in central subfield thickness postoperatively. Significant improvement in best-corrected Early Treatment Diabetic Retinopathy Study visual acuity was observed after treatment, likely because of cataract removal. RETINA 32:1799-1803, 2012
Resumo:
Five pilot-scale steam explosion pretreatments of sugarcane bagasse followed by alkaline delignification were explored. The solubilised lignin was precipitated with 98% sulphuric acid. Most of the pentosan (82.6%), and the acetyl group fractions were solubilised during pretreatment, while 90.2% of cellulose and 87.0% lignin were recovered in the solid fraction. Approximately 91% of the lignin and 72.5% of the pentosans contained in the steam-exploded solids were solubilised by delignification, resulting in a pulp with almost 90% of cellulose. The acidification of the black liquors allowed recovery of 48.3% of the lignin contained in the raw material. Around 14% of lignin, 22% of cellulose and 26% of pentosans were lost during the process. In order to increase material recovery, major changes, such as introduction of efficient condensers and the reduction in the number of washing steps, should be done in the process setup. (C) 2012 Elsevier Ltd. All rights reserved.
Resumo:
In this study, catalysts containing 5 wt.% Ni deposited on a support composed of a CeO2-ZrO2 solid solution deposited on alumina were tested in the steam reforming of methane. The supports, with various ratios of Ce to Zr, were prepared by co-precipitation of the oxide precursors, followed by calcination in synthetic air. The catalysts were then prepared by Ni impregnation of the supports. The prepared solids were characterized by temperature-programmed reduction with H-2 (TPR-H-2), in situ X-ray diffraction (XRD) and X-ray absorption near-edge structure (XANES) spectroscopy. The XRD analysis confirmed the formation of a solid solution between ZrO2 and CeO2. In the catalytic tests, it was found that catalysts with higher Ce content did not exhibit deactivation during 6 h of reaction. The catalyst with highest Ce content, Ni(0.8Ce0.2Zr)AI, provided the best result, with the highest rate of conversion of methane and the lowest carbon deposition, which may be partly due to the smaller Ni-0 crystallites in this sample and also the segregated CeO2 particles may have favored H2O adsorption which could lead to higher C gasification. (C) 2012 Elsevier B.V. All rights reserved.
Resumo:
To evaluate an innovative technique for intrastromal air injection to achieve deep anterior lamellar keratoplasty (DALK) with bare Descemet membrane (DM). Thirty-four eyes with anterior corneal pathology, including 27 with keratoconus, underwent DALK. After 400 mm trephination with a suction trephine, ultrasound pachymetry was performed 0.8 mm internally from the trephination groove in the 11 to 1 o'clock position. In this area, a 2-mm incision was created, parallel to the groove, with a micrometer diamond knife calibrated to 90% depth of the thinnest measurement. A cannula was inserted through the incision and 0.5 mL of air was injected to dissect the DM from the stroma. After peripheral paracentesis, anterior keratectomy was carried out to bare the DM. A 0.25-mm oversized graft was sutured in place. Overall, 94.1% of eyes achieved DALK. Bare DM was achieved in 30 eyes, and a pre-DM dissection was performed in 2 eyes. Air injection was successful in detaching the DM (achieving the big bubble) in 88.2% of the eyes. In keratoconus eyes, the rate was 88.9%. All cases but one required a single air injection to achieve DM detachment. Microperforations occurred in 5 cases: 3 during manual layer-by-layer dissection after air injection failed to detach the DM, 1 during removal of the residual stroma after big-bubble formation, and 1 during the diamond knife incision. Two cases (5.9%) were converted to penetrating keratoplasty because of macroperforations. The technique was reproducible, safe, and highly effective in promoting DALK with bare DM.
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Objectives/Hypothesis. Hepatocyte growth factor (HGF) is a multifunctional polypeptide that plays various roles in embryogenesis and tissue regeneration and exhibits marked antifibrotic activity. The present study sought to assess the effects of HGF injection and reinjection coinciding with its peak of activity on collagen density, vessel density, inflammatory reaction in the lamina propria, and mean epithelial thickness in the injured rabbit vocal fold. Study Design. Prospective, controlled, experimental animal study. Methods. Fourteen rabbits were subdivided into two groups and underwent injury of the vocal folds. Immediately after injury, animals in group 1 received HGF injections into the right vocal fold (RVF), whereas those in group 2 received bilateral HGF injections and a single reinjection into the RVF 10 days after the first, to coincide with the peak of HGF activity. The left vocal folds (LVFs) served as controls in both groups. Histological assessment of laryngeal specimens was performed at 30 and 40 days, respectively. Results. In both groups, collagen density was lower in the right (treated) vocal folds than in the left (control) folds (P = 0.018). Vessel density was higher in the RVFs in group 2 (P = 0.018). Differences were found in mean epithelial thickness and inflammatory reaction in the lamina propria but did not reach statistical significance. Conclusions. In the scarred rabbit vocal fold, HGF injection is associated with decreased collagen density in the lamina propria, whereas reinjection after 10 days produces decreased collagen density and higher vessel density.
Resumo:
Abstract Background The ability to manipulate the genetic networks underlying the physiological and behavioural repertoires of the adult honeybee worker (Apis mellifera) is likely to deepen our understanding of issues such as learning and memory generation, ageing, and the regulatory anatomy of social systems in proximate as well as evolutionary terms. Here we assess two methods for probing gene function by RNA interference (RNAi) in adult honeybees. Results The vitellogenin gene was chosen as target because its expression is unlikely to have a phenotypic effect until the adult stage in bees. This allowed us to introduce dsRNA in preblastoderm eggs without affecting gene function during development. Of workers reared from eggs injected with dsRNA derived from a 504 bp stretch of the vitellogenin coding sequence, 15% had strongly reduced levels of vitellogenin mRNA. When dsRNA was introduced by intra-abdominal injection in newly emerged bees, almost all individuals (96 %) showed the mutant phenotype. An RNA-fragment with an apparent size similar to the template dsRNA was still present in this group after 15 days. Conclusion Injection of dsRNA in eggs at the preblastoderm stage seems to allow disruption of gene function in all developmental stages. To dissect gene function in the adult stage, the intra-abdominal injection technique seems superior to egg injection as it gives a much higher penetrance, it is much simpler, and it makes it possible to address genes that are also expressed in the embryonic, larval or pupal stages.
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PURPOSE: To present a review about a comparative study of bile duct ligation versus carbon tetrachloride Injection for inducing experimental liver cirrhosis. METHODS: This research was made through Medline/PubMed and SciELO web sites looking for papers on the content "induction of liver cirrhosis in rats". We have found 107 articles but only 30 were selected from 2004 to 2011. RESULTS: The most common methods used for inducing liver cirrhosis in the rat were administration of carbon tetrachloride (CCl4) and bile duct ligation (BDL). CCl4 has induced cirrhosis from 36 hours to 18 weeks after injection and BDL from seven days to four weeks after surgery. CONCLUSION: For a safer inducing cirrhosis method BDL is better than CCl4 because of the absence of toxicity for researches and shorter time for achieving it.