Comparative visual outcomes of the first versus second eye following small-incision lenticule extraction (SMILE).

BACKGROUND: This study aimed to compare the visual outcomes of the first operated eyes with those of the second operated eyes following small-incision lenticule extraction (SMILE). METHODS: A total of 202 patients (404 eyes) underwent SMILE using the tear film mark centration method for myopia and myopic astigmatism correction. Baseline characteristics, objective optical quality, decentered displacement, induced corneal aberrations, and modulation transfer function (MTF) values were assessed. Linear regression analyzed the relationship between decentration and visual quality parameters, including corneal aberrations and MTF values. RESULTS: No significant difference was observed in objective visual quality, efficacy, and safety indexes between the two groups (all P > 0.05). The average decentered displacement for the first and second surgical eyes was 0.278 ± 0.17 mm and 0.315 ± 0.15 mm, respectively (P = 0.002). The horizontal coma in the first surgical eyes were notably lower than in the second (P = 0.000). MTF values at spatial frequencies of 5, 10, 15, and 20 cycles/degree (c/d) were higher in the first surgical eyes compared to the second (all P < 0.05). Linear regression indicated that high-order aberrations (HOAs), root mean square (RMS) coma, spherical aberration, horizontal coma, vertical coma, and eccentric displacement were all linearly correlated. Furthermore, MTF values exhibited a linear relationship with eccentric displacement across these spatial frequencies. CONCLUSIONS: There was no discernible difference in visual acuity, efficacy, or safety between the two operated eyes. Nonetheless, the first operated eyes exhibited reduced decentered displacement and demonstrated superior outcomes in terms of horizontal coma and MTF values compared to the second operated eyes following SMILE. The variations in visual quality parameters were linearly correlated with decentered displacement.

One-Step Electrochemical Ethylene-to-Ethylene Glycol Conversion over a Multitasking Molecular Catalyst.

Ethylene glycol is an essential commodity chemical with high demand, which is conventionally produced via thermocatalytic oxidation of ethylene with huge fossil fuel consumption and CO2 emission. The one-step electrochemical approach offers a sustainable route but suffers from reliance on noble metal catalysts, low activity, and mediocre selectivity. Herein, we report a one-step electrochemical oxidation of ethylene to ethylene glycol over an earth-abundant metal-based molecular catalyst, a cobalt phthalocyanine supported on a carbon nanotube (CoPc/CNT). The catalyst delivers ethylene glycol with 100% selectivity and 1.78 min-1 turnover frequency at room temperature and ambient pressure, more competitive than those obtained over palladium catalysts. Experimental data demonstrate that the catalyst orchestrates multiple tasks in sequence, involving electrochemical water activation to generate high-valence Co-oxo species, ethylene epoxidation to afford an ethylene oxide intermediate via oxygen transfer, and eventually ring-opening of ethylene oxide to ethylene glycol facilitated by in situ formed Lewis acid site. This work offers a great opportunity for commodity chemicals synthesis based on a one-step, earth-abundant metal-catalyzed, and renewable electricity-driven route.

Electrochemical carbon-carbon coupling with enhanced activity and racemate stereoselectivity by microenvironment regulation.

Enzymes are characteristic of catalytic efficiency and specificity by maneuvering multiple components in concert at a confined nanoscale space. However, achieving such a configuration in artificial catalysts remains challenging. Herein, we report a microenvironment regulation strategy by modifying carbon paper with hexadecyltrimethylammonium cations, delivering electrochemical carbon-carbon coupling of benzaldehyde with enhanced activity and racemate stereoselectivity. The modified electrode-electrolyte interface creates an optimal microenvironment for electrocatalysis-it engenders dipolar interaction with the reaction intermediate, giving a 2.2-fold higher reaction rate (from 0.13 to 0.28 mmol h-1 cm-2); Moreover, it repels interfacial water and modulates the conformational specificity of reaction intermediate by facilitating intermolecular hydrogen bonding, affording 2.5-fold higher diastereomeric ratio of racemate to mesomer (from 0.73 to 1.82). We expect that the microenvironment regulation strategy will lead to the advanced design of electrode-electrolyte interface for enhanced activity and (stereo)selectivity that mimics enzymes.

Unraveling the potential-dependent structure evolution in CuO for electrocatalytic biomass valorization.

Electrocatalytic oxidation of renewable biomass (such as glucose) into high-value-added chemicals provides an effective approach to achieving carbon neutrality. CuO-derived materials are among the most promising electrocatalysts for biomass electrooxidation, but the identification of their active sites under electrochemical conditions remains elusive. Herein, we report a potential-dependent structure evolution over CuO in the glucose oxidation reaction (GOR). Through systematic electrochemical and spectroscopic characterizations, we unveil that CuO undergoes Cu2+/Cu+ and Cu3+/Cu2+ redox processes at increased potentials with successive generation of Cu(OH)2 and CuOOH as the active phases. In addition, these two structures have distinct activities in the GOR, with Cu(OH)2 being favorable for aldehyde oxidation, and CuOOH showed faster kinetics in carbon-carbon cleavage and alcohol/aldehyde oxidation. This work deepens our understanding of the dynamic reconstruction of Cu-based catalysts under electrochemical conditions and may guide rational material design for biomass valorization.

Ocular Posterior Segment Distribution and Pharmacokinetics of Brimonidine After Intravitreal Administration in Guinea Pigs.

Purpose: Brimonidine is a highly alpha-2 adrenergic agonist, which provides a potential myopia control effect. This study aimed to examine the pharmacokinetics and concentration of brimonidine in the posterior segment tissue of eyes in guinea pigs. Methods: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was successfully used for brimonidine pharmacokinetics and tissue distribution research in guinea pigs following intravitreal administration (20 µg/eye). Results: Brimonidine concentrations in the retina and sclera were maintained at a high level (>60 ng/g) at 96 h postdosing. Brimonidine concentration peaked in the retina (377.86 ng/g) at 2.41 h and sclera (306.18 ng/g) at 6.98 h. The area under curve (AUC0-∞) was 27,179.99 ng h/g in the retina and 39,529.03 ng h/g in the sclera. The elimination half-life (T1/2e) was 62.43 h in the retina and 67.94 h in the sclera. Conclusions: The results indicated that brimonidine was rapidly absorbed and diffused to the retina and sclera. Meanwhile, it maintained higher posterior tissue concentrations, which can effectively activate the alpha-2 adrenergic receptor. This may provide pharmacokinetic evidence for the inhibition of myopia progression by brimonidine in animal experiments.

Remote Stereocenter through Amide-Directed, Rhodium-Catalyzed Enantioselective Hydroboration of Unactivated Internal Alkenes.

Despite the frequent occurrence of γ-branched amines in bioactive molecules, the direct catalytic asymmetric synthesis of this structural motif containing a remote stereocenter remains an important synthetic challenge. Here, we report an amide-directed, rhodium-catalyzed highly diastereo- and enantioselective hydroboration of unactivated internal alkenes. This method provided facile access to enantioenriched amines containing ß,γ-vicinal stereocenters. The application of this strategy to the synthesis of bioactive molecules was demonstrated. Computational studies indicated that migratory insertion of the alkene into rhodium hydride controls the enantioselectivity.

Mineralogical and chemical properties inversed from 21-lunar-day VNIS observations taken during the Chang'E-4 mission.

We report on the mineralogical and chemical properties of materials investigated by the lunar rover Yutu-2, which landed on the Von Kármán crater in the pre-Nectarian South Pole-Aitken (SPA) basin. Yutu-2 carried several scientific payloads, including the Visible and Near-infrared Imaging Spectrometer (VNIS), which is used for mineral identification, offering insights into lunar evolution. We used 86 valid VNIS data for 21 lunar days, with mineral abundance obtained using the Hapke radiative transfer model and sparse unmixing algorithm and chemical compositions empirically estimated. The mineralogical properties of the materials at the Chang'E-4 (CE-4) site referred to as norite/gabbro, based on findings of mineral abundance, indicate that they may be SPA impact melt components excavated by a surrounding impact crater. We find that CE-4 materials are dominated by plagioclase and pyroxene and feature little olivine, with 50 of 86 observations showing higher LCP than HCP in pyroxene. In view of the effects of space weathering, olivine content may be underestimated, with FeO and TiO2 content estimated using the maturity-corrected method. Estimates of chemical content are 7.42-18.82 wt% FeO and 1.48-2.1 wt% TiO2, with a low-medium Mg number (Mg # ~ 55). Olivine-rich materials are not present at the CE-4 landing site, based on the low-medium Mg #. Multi-origin materials at the CE-4 landing site were analyzed with regard to concentrations of FeO and TiO2 content, supporting our conclusion that the materials at CE-4 do not have a single source but rather are likely a mixture of SPA impact melt components excavated by surrounding impact crater and volcanic product ejecta.

A BODIPY-carbazole hybrid as a fluorescent probe: the design, synthesis, and discrimination of surfactants and the determination of the CMC values.

Surfactants play important roles in chemical industries and have become well-known environmental pollutants owing to their extensive use in different fields. In this work, we reported a fluorescent probe, namely, BDP-Zn2+ for the discrimination of four kinds of surfactants and the determination of CMC values. BDP-Zn2+ was composed of covalently linked BODIPY, carbazole, N,N-bis(2-pyridylmethyl)ethylenediamine (BPEA) and zinc ions to fabricate a novel push-pull molecular structure. Upon the addition of surfactants, the probe exhibited a turn-on fluorescence response and the emission was enhanced on increasing the surfactant concentrations. This indicated that the fluorescence intensity and the ratios of the emission at 607 nm to that at 514 nm as fingerprints could be used to identify the CMC values of the surfactants. Our current work provides an alternative method to efficiently discriminate different surfactants for the further studies of their physical and chemical functions.