Sorbents with high efficiency for CO2 capture based on amines-supported carbon for biogas upgrading.

Sorbents for CO2 capture have been prepared by wet impregnation of a commercial active carbon (Ketjen-black, Akzo Nobel) with two CO2-philic compounds, polyethylenimine (PEI) and tetraethylenepentamine (TEPA), respectively. The effects of amine amount (from 10 to 70wt.%), CO2 concentration in the feed, sorption temperature and gas hourly space velocity on the CO2 capture performance have been investigated. The sorption capacity has been evaluated using the breakthrough method, with a fixed bed reactor equipped with on line gas chromatograph. The samples have been characterized by N2 adsorption-desorption, scanning electron microscopy and energy dispersive X-ray (SEM/EDX). A promising CO2 sorption capacity of 6.90 mmol/gsorbent has been obtained with 70wt.% of supported TEPA at 70°C under a stream containing 80vol% of CO2. Sorption tests, carried out with simulated biogas compositions (CH4/CO2 mixtures), have revealed an appreciable CO2 separation selectivity; stable performance was maintained for 20 adsorption-desorption cycles.

Intravitreal bevacizumab as primary treatment for retinal angiomatous proliferation: twelve-month results.

PURPOSE: To evaluate the short-term efficacy and safety of intravitreal bevacizumab for the treatment of retinal angiomatous proliferation. METHODS: Seventeen eyes from 16 patients with newly diagnosed retinal angiomatous proliferation underwent intravitreal injections of bevacizumab, 1.25 mg. The patients were scheduled for three monthly bevacizumab injections. Early Treatment of Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity, central macular thickness on optical coherence tomography, and fluorescein angiographic findings were examined before and after treatment. Patients were followed-up for 12 months. RESULTS: The mean best-corrected visual acuity (+/- standard deviation [SD]) at baseline was 39.53 (+/-10.40) letters (Snellen equivalent: 20/42). At 12 months after treatment the mean best-corrected visual acuity (+/-SD) improved significantly (P = 0.0000001) to 47.88 (+/-11.78) letters (Snellen equivalent: 20/28). Best-corrected visual acuity improved 3 ETDRS lines or more in 3 (17.65%) of 17 treated eyes, 14 (82.35%) eyes were stable, and 15 (88.23%) eyes gained 1 or more ETDRS lines. The mean central macular thickness (+/-SD) at baseline was 297 (+/-60.72) microm. At 12 months after treatment, the mean central macular thickness (+/-SD) reduced significantly (P = 0.00001) to 237 (+/-28.80) microm. At the 12-month follow-up, absence of fluorescein leakage was demonstrated in 14 (82%) of 17 treated eyes. No ocular or systemic adverse effects from treatment were encountered. CONCLUSION: The 12-month results of intravitreal bevacizumab for retinal angiomatous proliferation are very promising with no apparent short-term safety concerns. Treated eyes had a significant functional and anatomical improvement. Further studies will be needed to better determine long-term efficacy and safety.

The influence of learning effect on frequency doubling technology perimetry (Matrix).

PURPOSE: To determine learning effect in healthy patients without perimetric experience, tested with the frequency doubling technology perimetry, with the new model Matrix. PATIENTS AND METHODS: Frequency doubling technology in the 30-2 threshold mode was performed on 37 healthy subjects. Each subject was tested twice in different sessions. The test always began with the right eye (RE) and continued with the left eye (LE). To evaluate learning effect the results of the REs at the first session were compared with those of the LE. The following parameters were evaluated: foveal threshold (FT), reliability indexes, mean defect (MD), pattern standard deviation (PSD), glaucoma hemifield test (GHT), duration of examination. RESULTS: At the first session the average values of RE were FT=30.81 db, MD=-1 db, PSD=3.01 db, and duration of the examination=383.27 "and of LE were FT=30.73, MD=-0.79 db, PSD=2.97 db, and duration of examination 382.62." At the second session the average values of RE were FT=32.22 db, MD=+0.16 db, PSD 2.75 db, and duration of examination=374.97 db. The reliability was different and the GHT between the RE and LE in the first and second session was also different. CONCLUSIONS: A learning effect was observed between the first and the second sessions and the results of the GHT appeared improved. This above all should be taken into account when considering the clinical use of this test to avoid erroneous diagnostic conclusions.

Open-angle glaucoma: variations in the intraocular pressure after visual field examination.

PURPOSE: To evaluate intraocular pressure (IOP) variations after automated visual field examination in patients with primary open-angle glaucoma and in healthy subjects. PATIENTS AND METHODS: Intraocular pressure was measured in 49 patients (94 eyes) with primary open-angle glaucoma and in 13 healthy subjects (26 eyes) before and immediately after automated visual field examination. All patients had stable IOP and were using local medication to treat glaucoma. The visual field test was performed with a Humphrey 630 VF analyzer and the Central 30-2 full-threshold program. RESULTS: Mean IOP increased significantly in glaucomatous patients immediately after automated visual field examination (P < 0.01), and returned to pretest values after 1 hour (P = 0.2). Mean IOP variation was 2.38 (range, -6-11) mm Hg. In 42 (44.68%) glaucomatous eyes, IOP increased more than 2 mm Hg, with a mean increase of 5.5 mm Hg. Elderly glaucoma patients showed a significantly higher IOP rise than younger patients. No significant IOP variation was detected in healthy subjects. CONCLUSION: Intraocular pressure varied significantly and tended to increase immediately after automated visual field examination in patients with primary open-angle glaucoma. Age seemed to contribute to these IOP changes, but other factors could be involved.