138 resultados para graded-index fiber lens
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This work aimed to study the in vitro colonic fermentation profile of unavailable carbohydrates of two different kinds of unripe banana flour and to evaluate their postprandial glycemic responses. The unripe banana mass (UBM), obtained from the cooked pulp of unripe bananas (Musa acuminata, Nanico variety), and the unripe banana starch (UBS), obtained from isolated starch of unripe banana, plantain type (Musa paradisiaca) in natura, were studied. The fermentability of the flours was evaluated by different parameters, using rat inoculum, as well as the glycemic response produced after the ingestion by healthy volunteers. The flours presented high concentration of unavailable carbohydrates, which varied in the content of resistant starch, dietary fiber and indigestible fraction (IF). The in vitro colonic fermentation of the flours was high, 98% for the UBS and 75% for the UBM when expressed by the total amount of SCFA such as acetate, butyrate and propionate in relation to lactulose. The increase in the area under the glycemic curve after ingestion of the flours was 90% lower for the UBS and 40% lower for the UBM than the increase produced after bread intake. These characteristics highlight the potential of UBM and UBS as functional ingredients. However, in vivo studies are necessary in order to evaluate the possible benefic effects of the fermentation on intestinal health.
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Foods that contain unavailable carbohydrates may lower the risks for some non-transmissible chronic diseases because of the potential benefits provided by the products of colonic fermentation. On the other hand, foods that are sources of available carbohydrates may have higher energy value and increase the post-prandial glycemic response. The biomarker glycemic index and the resulting glycemic load may be used to classify foods according to their potential to increase blood glucose. Information about glycemic index and glycemic load may be useful in diet therapy. Currently, food composition tables in Brazil do not provide data for individually analyzed carbohydrates even though some quality data are available in scientific publications. The objectives of this work were to produce and compile information about the concentration of individual carbohydrates in foods and their glycemic responses and to disseminate this information through the Brazilian Food Composition Database (TBCA-USP). The glycemic index and glycemic load of foods were evaluated in healthy individuals. Concentrations of available carbohydrates (soluble sugars and available starch) and unavailable carbohydrates (dietary fiber, resistant starch, beta-glucans, fructans) were quantified by official methods, and other national data were compiled. TBCA-USP (http://www.fcf.usp.br/tabela), which is used by professionals and the population in general, now offers both chemical and biological information for carbohydrates. (C) 2009 Elsevier Inc. All rights reserved.
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An enantioselective liquid chromatographic method using two-phase hollow fiber liquid-phase microextraction (HF-LPME-HPLC) was developed for the determination of isradipine (ISR) enantiomers and its main metabolite (pyridine derivative of isradipine, PDI) in microsomal fractions isolated from rat liver. The analytes were extracted from 1 mL of microsomal medium using a two-phase HF-LPME procedure with hexyl acetate as the acceptor phase, 30 min of extraction, and sample agitation at 1,500 rpm. For the first time, ISR enantiomers and PDI were resolved. For this separation, a ChiralpakA (R) AD column with hexane/2-propanol/ethanol (94:04:02, v/v/v) as the mobile phase at a flow rate of 1.5 mL min(-1) was used. The column was kept at 23 A +/- 2 A degrees C. The drug and metabolite detection was performed at 325 nm and the internal standard oxybutynin was detected at 225 nm. The recoveries were 23% for PDI and 19% for each ISR enantiomer. The method presented quantification limits (LOQ) of 50 ng mL(-1) and was linear over the concentration range of 50-5,000 and 50-2,500 ng mL(-1) for PDI and each ISR enantiomer, respectively. The validated method was employed to an in vitro biotransformation study of ISR using rat liver microsomal fraction showing that (+)-(S)-ISR is preferentially biotransformed.
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A three-phase hollow-fiber liquid-phase microextraction method for the analysis of rosiglitazone and its metabolites N-desmethyl rosiglitazone and p-hydroxy rosiglitazone in microsomal preparations is described for the first time. The drug and metabolites HPLC determination was carried out using an X-Terra RP-18 column, at 22 degrees C. The mobile phase was composed of water, acetonitrile and acetic acid (85:15:0.5, v/v/v) and the detection was performed at 245 nm. The hollow-fiber liquid-phase microextraction procedure was optimized using multifactorial experiments and the following optimal condition was established: sample agitation at 1750 rpm, extraction for 30 min, hydrochloric acid 0.01 mol/L as acceptor phase, 1-octanol as organic phase, and donor phase pH adjustment to 8.0. The recovery rates, obtained by using 1 mL of microsomal preparation, were 47-70%. The method presented LOQs of 50 ng/mL and it was linear over the concentration range of 50-6000 ng/mL, with correlation coefficients (r) higher than 0.9960, for all analytes. The validated method was employed to study the in vitro biotransformation of rosiglitazone using rat liver microsomal fraction.
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Background and purpose: The effects of centrally administered cannabinoids on body core temperature (Tc) and the contribution of endogenous cannabinoids to thermoregulation and fever induced by lipopolysaccharide (LPS) (Sigma Chem. Co., St. Louis, MO, USA) were investigated. Experimental approach: Drug-induced changes in Tc of male Wistar rats were recorded over 6 h using a thermistor probe (Yellow Springs Instruments 402, Dayton, OH, USA) inserted into the rectum. Key results: Injection of anandamide [(arachidonoylethanolamide (AEA); Tocris, Ellisville, MO, USA], 0.01-1 mu g i.c.v. or 0.1-100 ng intra-hypothalamic (i.h.), induced graded increases in Tc (peaks 1.5 and 1.6 degrees C at 4 h after 1 mu g i.c.v. or 10 ng i.h.). The effect of AEA (1 mu g, i.c.v.) was preceded by decreases in tail skin temperature and heat loss index (values at 1.5 h: vehicle 0.62, AEA 0.48). Bell-shaped curves were obtained for the increase in Tc induced by the fatty acid amide hydrolase inhibitor [3-(3-carbamoylphenyl)phenyl] N-cyclohexylcarbamate (Cayman Chemical Co., Ann Arbor, MI, USA) (0.001-1 ng i.c.v.; peak 1.9 degrees C at 5 h after 0.1 ng) and arachidonyl-2-chloroethylamide (ACEA; Tocris) (selective CB(1) agonist; 0.001-1 mu g i.c.v.; peak 1.4 degrees C 5 h after 0.01 mu g), but (R,S)-(+)-(2-Iodo-5-nitrobenzoyl)-[1-(1-methyl-piperidin-2-ylmethyl)-1H-indole-3-yl] methanone (Tocris) (selective CB(2) agonist) had no effect on Tc. AEA-induced fever was unaffected by i.c.v. pretreatment with 6-Iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indole-3-yl](4-methoxyphenyl) methanone (Tocris) (selective CB(2) antagonist), but reduced by i.c.v. pretreatment with N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251; Tocris) (selective CB(1) antagonist). AM251 also reduced the fever induced by ACEA or LPS. Conclusions and implications: The endogenous cannabinoid AEA induces an integrated febrile response through activation of CB(1) receptors. Endocannabinoids participate in the development of the febrile response to LPS constituting a target for antipyretic therapy.
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This article reports a study on the preparation, densification process, and structural and optical properties of SiO(2)-Ta(2)O(5) nanocomposite films obtained by the sol-gel process. The films were doped with Er(3+) and the Si:Ta molar ratio was 90:10. Values of refractive index, thickness and vibrational modes in terms of the number of layers and thermal annealing time are described for the films. The densification process is accompanied by OH group elimination, increase in the refractive index, and changes in film thickness. Full densification of the film is acquired after 90 min of annealing at 900 degrees C. The onset of crystallization and devitrification, with the growth of Ta(2)O(5) nanocrystals occurs with film densification, evidenced by high-resolution transmission electron microscopy. The Er(3+)-doped nanocomposite annealed at 900 degrees C consists of Ta(2)O(5) nanoparticles, with sizes around 2 nm, dispersed in the SiO(2) amorphous phase. The main emission peak of the film is detected at around 1532 nm, which can be assigned to the (4)I(13/2)->(4)I(15/2) transition of the Er(3+) ions present in the nanocomposites. This band has a full width at half medium of 64 nm, and the lifetime measured for the (4)I(13/2) levels is 5.4 ms, which is broader compared to those of other silicate systems. In conclusion, the films obtained in this work are excellent candidates for use as active planar waveguide. (C) 2010 Elsevier B.V. All rights reserved.
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PURPOSE: To determine whether implantation of an aspherical intraocular lens (IOL) results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery without critical reduction of depth of focus. DESIGN: Double-blinded, randomized, prospective study. METHODS: In an intraindividual study of 25 patients with bilateral cataract, an aspherical IOL (Akreos Advanced Optic [AO]; Bausch & Lomb, Inc., Rochester, New York, USA) was implanted in one eye and a spherical IOL (Akreos Fit; Bausch & Lomb, Inc) in the fellow eye. Higher-order aberrations with a 5- and 6-mm pupil were measured with a dynamic retinoscopy aberrometer at 1 and 3 months after surgery. Uncorrected and best-corrected visual acuity and contrast sensitivity under mesopic and photopic conditions also were measured. Distance-corrected near and intermediate visual acuity were studied as a measurement of depth of focus. RESULTS: There was no statistically significant difference between eyes in uncorrected and best-corrected visual acuity at I and 3 months after surgery. There was a statistically significant between-group difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. The Akreos AO group obtained statistically significant lower values of higher-order aberrations and spherical aberration with 5- and 6-mm pupils compared with the Akreos Fit group (P < .05). There was no significant difference in distance-corrected near and intermediate visual acuity between both groups. CONCLUSIONS: Aspherical aberration-free Akreos AO IOL induced significantly less higher-order aberrations and spherical aberration than the Akreos Fit. Contrast sensitivity was better under mesopic conditions with the Akreos AO with similar results of depth of focus. (Am J Ophthalmol 2010;149:383-389. (C) 2010 by Elsevier Inc. All rights reserved.)
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Chronic hepatitis C (CHC) is one of the most important causes of chronic liver disease in the world, potentially resulting in cirrhosis, hepatocellular carcinoma, and the need for liver transplantation. Liver biopsy is currently performed before therapy indication. Although, it is the golden standard there are many reasons to avoid or delay the procedure. APRI Score is an easy, low cost and practice alternative method which was described as an alternative for assessing structural changes in chronic hepatitis C (CHC). The rationale of this study was to observe the accuracy of APRI Score in comparison to liver biopsy in 400 patients divided into two groups of 200 carriers (Validation and Experimental groups respectively) selected at random or according to liver fibrosis staging (METAVIR). The ROC curves showed a concordance among these two methods of 92% and 88.5% when 1.05 was the cut off (F3 and F4), and 87% and 83%, on 0.75 cut offs (F2-F4). The discordance in advanced fibrosis staging (F3 and F4) was only 16 (8%) and 22 (11%) out of 200 patients in the experimental and validation groups, respectively. In 26 (13%) out of 200 patients in the experimental group and 34 (17%) out of 200 patients in the validation group, there was discordance between APRI Score and liver biopsy in moderate and advanced fibrosis (F2-F4). In conclusion APRI is a serological marker that has satisfactory sensitivity and specificity together with a high predictive value and it can be useful either in the absence of a biopsy or to reduce the frequency with which biopsies need to be carried out to monitor the evolution of chronic hepatitis C and the right moment for treatment indication.
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Background Type 2 diabetes mellitus (T2DM) is a common disease with numerous complications. Bariatric surgery is an efficient procedure for controlling T2DM in morbidly obese patients. In T2DM, the incretin effect is either greatly impaired or absent. This study aimed to evaluate the preliminary results from interposing a segment of ileum into the proximal jejunum associated with a sleeve or diverted sleeve gastrectomy to control T2DM in patients with a body mass index (BMI) less than 35 kg/m(2). Methods For this study, 39 patients (16 women and 23 men) underwent two laparoscopic procedures comprising different combinations of ileal interposition into the proximal jejunum via a sleeve or diverted sleeve gastrectomy. The mean age of these patients was 50.3 years (range, 36-66 years). The mean BMI was 30.1 kg/m(2) (range, 23.4-34.9 kg/m(2)). All the patients had a diagnosis of T2DM that had persisted for at least 3 years and evidence of stable treatment with oral hypoglycemic agents or insulin for at least 12 months. The mean duration of T2DM was 9.3 years (range, 3-22 years). Results The mean operative time was 185 min, and the median hospital stay was 4.3 days. Four major complications occurred in the short term (30-days), and the mortality rate was 2.6%. The mean postoperative follow-up period was 7 months (range, 4-16 months), and the mean percentage of weight loss was 22%. The mean postoperative BMI was 24.9 kg/m(2) (range, 18.9-31.7 kg/m2). An adequate glycemic control was achieved for 86.9% of the patients, and 13.1% had important improvement. The patients whose glycemia was not normalized were using a single oral hypoglycemic agent. No patient needed insulin therapy postoperatively. All the patients except experienced normalization of their cholesterol levels. Targeted triglycerides levels were achieved by 71% of the patients, and hypertension was controlled for 95.8%. Conclusions The laparoscopic ileal interposition via either a sleeve gastrectomy or diverted sleeve gastrectomy seems to be a promising procedure for the control of T2DM and the metabolic syndrome. A longer follow-up period is needed.
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Nani FS, Torres MLA - Correlation between the Body Mass Index (BMI) of Pregnant Women and the Development of Hypotension after Spinal Anesthesia for Cesarean Section. Background and objectives: Very few publications correlate hypotension in obese pregnant women, and especially morbidly obese, after spinal anesthesia for cesarean section. The objective of the present study was to evaluate the incidence of hypotension according to the BMI. Methods: Forty-nine patients with pregestational BMI below 25 kg.m(-2) were included in the Eutrophia group, and 51 patients with BMI >= 25 kg.m(-2) were included in the Overweight group. After spinal anesthesia, blood pressure, volume of crystalloid infused, and dose of vasopressors used until delivery were recorded. A fall in systolic blood pressure below 100 mmHg or 10% reduction of the initial systolic blood pressure (SBP) was considered as hypotension and it was corrected by the administration of vasopressors. Results: Episodes of hypotension were fewer in the Eutrophia group (5.89 +/- 0.53 vs. 7.80 +/- 0.66, p = 0.027), as well as the amount of crystalloid administered (1,298 +/- 413.6 mL vs. 1,539 +/- 460.0 mL; p = 0.007), and use of vasopressors (5.87 +/- 3.45 bolus vs. 7.70 +/- 4.46 bolus; p = 0.023). As for associated diseases, we observed higher incidence of diabetes among obese pregnant women (29.41% vs. 9.76%, RR 1.60, 95%CI: 1.15-2.22, p = 0.036), however, differences in the incidence of pregnancy-induced hypertension (PIN) were not observe between both groups (overweight: 21.57%, normal weight: 12.20%, RR 1.30, 95%CI: 0.88-1.94, p = 0.28). Conclusions: In the study sample, pregestational BMI >= 25 kg.m(-2) was a risk factor for hypotension after spinal anesthesia in patients undergoing cesarean section. The same group of patients required higher doses of vasopressors. Those results indicate that the anesthetic techniques in those patients should be improved to reduce the consequences of post-spinal anesthesia hypotension, both in pregnant women and fetuses.
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Background: Different hemodynamic parameters including static indicators of cardiac preload as right ventricular end-diastolic volume index (RVEDVI) and dynamic parameters as pulse pressure variation (PPV) have been used in the decision-making process regarding volume expansion in critically ill patients. The objective of this study was to compare fluid resuscitation guided by either PPV or RVEDVI after experimentally induced hemorrhagic shock. Methods: Twenty-six anesthetized and mechanically ventilated pigs were allocated into control (group I), PPV (group II), or RVEDVI (group III) group. Hemorrhagic shock was induced by blood withdrawal to target mean arterial pressure of 40 mm Hg, maintained for 60 minutes. Parameters were measured at baseline, time of shock, 60 minutes after shock, immediately after resuscitation with hydroxyethyl starch 6% (130/0.4), 1 hour and 2 hours thereafter. The endpoint of fluid resuscitation was determined as the baseline values of PPV and RVEDVI. Statistical analysis of data was based on analysis of variance for repeated measures followed by the Bonferroni test (p < 0.05). Results: Volume and time to resuscitation were higher in group III than in group II (group III = 1,305 +/- 331 mL and group II = 965 +/- 245 mL, p < 0.05; and group III = 24.8 +/- 4.7 minutes and group II = 8.8 +/- 1.3 minutes, p < 0.05, respectively). All static and dynamic parameters and biomarkers of tissue oxygenation were affected by hemorrhagic shock and nearly all parameters were restored after resuscitation in both groups. Conclusion: In the proposed model of hemorrhagic shock, resuscitation to the established endpoints was achieved within a smaller amount of time and with less volume when guided by PPV than when guided by pulmonary artery catheter-derived RVEDVI.
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Abnormal heart-rate (HR) response during or after a graded exercise test has been recognized as a strong and an independent predictor of all-cause mortality in healthy and diseased subjects. The purpose of the present study was to evaluate the HR response during exercise in women with systemic lupus erythematosus (SLE). In this case-control study, 22 women with SLE (age 29.5 perpendicular to 1.1 years) were compared with 20 gender-, BMI-, and age-matched healthy subjects (age 26.5 +/- 1.4 years). A treadmill cardiorespiratory test was performed and HR response during exercise was evaluated by the chronotropic reserve (CR). HR recovery (Delta HRR) was defined as the difference between HR at peak exercise and at both first (Delta HRR1) and second (Delta HRR2) minutes after exercising. SLE patients presented lower peak VO(2) when compared with healthy subjects (27.6 perpendicular to 0.9 vs. 36.7 perpendicular to 1.1 ml/kg/min, p = 0.001, respectively). Additionally, SLE patients demonstrated lower CR (71.8 +/- 2.4 vs. 98.2 +/- 2.6%, p = 0.001), Delta HRR1 (22.1 +/- 2.5 vs. 32.4 +/- 2.2%, p = 0.004) and Delta HRR2 (39.1 +/- 2.9 vs. 50.8 +/- 2.5%, p = 0.001) than their healthy peers. In conclusion, SLE patients presented abnormal HR response to exercise, characterized by chronotropic incompetence and delayed Delta HRR. Lupus (2011) 20, 717-720.
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BACKGROUND: Alcoholic beverages may have protective cardiovascular effects but are known to increase the plasma levels of triglycerides (TG). Both TG and the ratio of TO to high-density lipoprotein cholesterol (TG/HDL-cholesterol) are associated with increased cardiovascular risk. OBJECTIVES: To determine the predictive factors for variations in plasma levels of TO and the TG/HDL-cholesterol ratio in patients after they had consumed red wine for 14 days. METHODS: Forty-two subjects (64% men, 46 +/- 9 years, baseline body mass index [BMI] 25.13 +/- 2.76 kg/m(2)) were given red wine (12% or 12.2% alc/vol, 250 mL/day with meals). Plasma concentration of lipids and glucose were measured before and after red wine consumption. Blood was collected after 12 hours of fast and alcohol abstention. RESULTS: Red wine increased plasma levels of TO from 105 +/- 42 mg/dL to 120 +/- 56 mg/dL (P = .001) and the TG/HDL-cholesterol ratio from 2.16 +/- 1.10 to 2.50 +/- 1.66 (P = .014). In a multivariate linear regression model that included age, baseline BMI, blood pressure, lipids, and glucose, only BMI was independently predictive of the variation in plasma TO after red wine (beta coefficient 0.592, P < .001). BMI also predicted the variation in TG/HDL-cholesterol ratio (beta coefficient 0.505, P = .001, adjusted model). When individuals were divided into three categories, according to their BMI, the average percentage variation in TG after red wine was -4%, 17%, and 33% in the lower (19.60-24.45 kg/m(2)), intermediate, and greater (26.30-30.44 kg/m(2)) tertiles, respectively (P = .001). CONCLUSIONS: Individuals with higher BMI, although nonobese, might be at greater risk for elevation in plasma TO levels and the TG/HDL-cholesterol ratio after short-term red wine consumption. (C) 2011 National Lipid Association. All rights reserved.
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Background: UV radiation is the major environmental factor related to development of cutaneous melanoma. Besides sun exposure and the influence of latitude, some host characteristics such as skin phototype and hair and eye color are also risk factors for melanoma. Polymorphisms in DNA repair genes could be good candidates for susceptibility genes, mainly in geographical regions exposed to high solar radiation. Objective: Evaluate the role of host characteristic.; and DNA repair polymorphism in melanoma risk in Brazil. Methods: We carried out a hospital-based case-control study in Brazil to evaluate the contribution of host factors and polymorphisms in DNA repair to melanoma risk. A total of 412 patients (202 with melanoma and 210 controls) were analyzed regarding host characteristics for melanoma risk as well as for 11 polymorphisms in DNA repair genes. Results: We found an association of host characteristics with melanoma development, such as eye and hair color, fair skin, history of pigmented lesions removed, sunburns in childhood and adolescence, and also European ancestry. Regarding DNA repair gene polymorphisms, we found protection for the XPG 1104 His/His genotype (OR 0.32; 95% CI 0.13-0.75), and increased risk for three polymorphisms in the XPC gene (PAT+; IV-6A and 939Gln), which represent a haplotype for XPC. Melanoma risk was higher in individuals carrying the complete XPC haplotype than each individual polymorphism (OR 3.64; 95% CI 1.77-7.48). Conclusions: Our data indicate that the host factors European ancestry and XPC polymorphisms contributed to melanoma risk in a region exposed to high sun radiation. (C) 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.
Trypan blue staining for capsulorhexis: Ultrastructural effect on lens epithelial cells and capsules
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PURPOSE: To evaluate the ultrastructural effect of trypan blue 0.1% staining for capsulorhexis on lens epithelial cells (LECs) and capsules SETTING: Division of Ophthalmology. University of Sao Paulo, Sao Paulo, Brazil METHODS: Before capsulorhexis, patients were randomly assigned to 1 of 2 groups Trypan blue 0 1% staining was performed in the treatment group No trypan blue was used in the control group Samples of capsules with LECs were fixed and analyzed with routine optical microscopy techniques. immunohistochemistry for beclin-1 expression (a marker of autophagy), terminal deoxynucleotidyl transf erase-mediated dUTP-biotin nick-end labeling to detect apoptosis, and transmission electron microscopy (TEM) Morphometric analyses were performed. and the 2 sets of data were compared. RESULTS: Each group comprised 15 patients Cell death by autophagy and apoptosis was observed in the treatment group but not in the control group The TEM images of subcapsular epithelium cells showed mitochondria` rupture, dilation of the cisterns of the endoplasmic reticulum, increased cytoplasmic and nuclear electron density, and abnormalities in the nuclear profile of trypan blue-stained cells. Morphometric analysis showed statistically significant differences between the 2 groups in the longest nuclear axes and the ratio between the total nuclear perimeter and the cell area (P = .03) The difference in capsule thickness between groups was not significant. CONCLUSION: Trypan blue caused LEC death, which supports the hypothesis that staining with trypan blue 0 1% can help reduce the incidence of posterior capsule pacification after cataract surgery