Comparing surgical efficiencies between phacoemulsification systems: a single surgeon retrospective study of 2000 eyes

AIM: To compare under similar conditions intraoperative surgical efficiencies metrics between an active fluidics and a gravity based phacoemulsification systems.METHODS: Adult patients who were diagnosed with a cataract that compromised visual acuity inferior to 20/40 were included in the study. Patients were excluded from the study if they had a history of severe retinal disorders, clinically significant corneal endothelial dystrophy or history of corneal disease. All phacoemulsification surgeries were performed by a single surgeon. Both phacoemulsification systems used the 0.9 mm 45-degree aspiration bypass system Intrepid Balanced tip and the 0.9 mm Intrepid Ultra infusion sleeve. All cataracts were classified using the Lens Opacities Classification System III, cumulative dissipated energy(CDE) and aspiration fluids were measured in each surgery.RESULTS: Totally 2000 eyes were included in the study. Phacoemulsification was performed in 1000(50%) eyes with an active fluid dynamics system and in 1000(50%) eyes with a gravity-based fluidic system. Mean CDE until fracture of the lens was 1.1 and 1.9 percent-seconds and total mean CDE used was 5.6 and 7.2 percent-seconds using an active fluidics dynamics system and gravity-based fluidic system, respectively(P<0.001). Mean aspiration fluids used were 70 m L using an active fluidics dynamics system and 85 m L using a gravity-based fluidic system(P<0.001).CONCLUSION: This study evidences that surgeries performed under similar conditions(same surgeon, phaco tip and sleeve) with the active fluidics dynamics system required significantly lower CDE and aspiration fluids.

CoMnMgAl Hydrotalcite-like Compounds and their Complex Oxides: Facile Synthesis and FCC SO_x Removal

The X-CoMnMgAl hydrotalcite-like precursors(X-LDHs) were first synthesized by the coprecipitation method using Cl-, CO32-, NO3- and SO42- as the corresponding guest anions, which were further used to prepare X-CoMnMgAl complex oxides(X-LDOs) through calcination. The structure and the surface morphology of the as-prepared samples were characterized by FT–IR, XRD, N2 adsorption-desorption and SEM. These as-prepared X-LDOs could act as sulfur-transfer catalysts for desulfurization. The activity of SOx adsorption and regeneration was evaluated via a self-assembled fixed-bed reactor simulating the conditions found in the fluid catalytic cracking units. These four types of sulfur-transfer catalysts with the same phase but different structure displayed the following order of desulfurization efficiency: CO3-LDO >Cl-LDO >NO3-LDO > SO4-LDO.

A Mathematical Model to Characterize RH Desulfurization Process

A physical model based on similarity principles was built to simulate RH desulfurization process. In order to quantitatively analyze RH desulfurization process, a mathematical model was proposed. By analyzing experimental results with the mathematical model, an empirical formula whose determination coefficient was 0.98 was given to express the relationship between transient desulfurization efficiency and time. All the determination coefficients of four fitted curves based on four repeated experiments with different gas flow rates were more than 0.94, which was the exact evidence of the rationality of the empirical formula. Meanwhile, it was found that transient desulfurization ability increased firstly and then decreased with increasing gas flow rate and reached the maximum value when the gas flow rate was 1.8 m^3/h. A plenty of repeated trials showed the same rule, which validated the mathematical model and the conclusions obtained from physical experiments.

Screening of Fungi from Chinese Medical Plants for Anti-Human Immunodeficiency Virus Type 1 Activity

In order to Isolate anti-human Immunodeflclency virus （HIV） agents from natural products, 97 ethanollc extracts of 90 fungi were tested for their Inhibitory activity on HIV-1. Most of the extracts tested were relatively non-toxic to human lymphocytic MT-4 cells, but extracts of some fungi exhibited potent antl-HIV activity In an in vitro 3-（4, 5-dlmethyl-2 thlazoyl）-2,5-dlphenyl-2H-tetrazollum bromide assay with a selectivity Index greater than 3. Most fungi were Isolated from Dendrobium sp. and Taxus sp.