SDEGen: learning to evolve molecular conformations from thermodynamic noise for conformation generation.

Generation of representative conformations for small molecules is a fundamental task in cheminformatics and computer-aided drug discovery, but capturing the complex distribution of conformations that contains multiple low energy minima is still a great challenge. Deep generative modeling, aiming to learn complex data distributions, is a promising approach to tackle the conformation generation problem. Here, inspired by stochastic dynamics and recent advances in generative modeling, we developed SDEGen, a novel conformation generation model based on stochastic differential equations. Compared with existing conformation generation methods, it enjoys the following advantages: (1) high model capacity to capture multimodal conformation distribution, thereby searching for multiple low-energy conformations of a molecule quickly, (2) higher conformation generation efficiency, almost ten times faster than the state-of-the-art score-based model, ConfGF, and (3) a clear physical interpretation to learn how a molecule evolves in a stochastic dynamics system starting from noise and eventually relaxing to the conformation that falls in low energy minima. Extensive experiments demonstrate that SDEGen has surpassed existing methods in different tasks for conformation generation, interatomic distance distribution prediction, and thermodynamic property estimation, showing great potential for real-world applications.

Effect of femtosecond laser cutting parameters on the results of small-incision lenticule extraction.

PURPOSE: To determine the effect of femtosecond laser cutting parameters on small-incision lenticule extraction (SMILE) results by evaluating cap thickness, interface light scattering, and visual and refractive outcomes. SETTING: SynsLaser Clinic, Oslo, Norway. DESIGN: Retrospective. METHODS: 58 right eyes treated with SMILE using a programmed cap thickness of 130 µm were divided into 2 groups according to laser settings: Group 1: 165 nJ pulse energy and 4.5 µm spot separation (n = 36); Group 2: 125 nJ pulse energy and 4.2 µm spot separation (n = 22). The cap thickness was measured within the central 5 mm of the horizontal meridian using spectral-domain optical coherence tomography. Postoperative interface light scattering was graded based on the percentage area showing light scattering: 0: no scattering; 1: ≤25%; 2: 26% to 50%; 3: 51% to 75%; and 4: >75%. RESULTS: At 3 months postoperatively, cap thickness was 138.9 ± 6.2 µm in Group 1 and 149.4 ± 3.5 µm in Group 2 ( P < .001). Interface scattering was 0.9 ± 1.0 in Group 1 and 0.3 ± 0.9 in Group 2 ( P < .05), with no scattering in 33.3% and 86.4% of the eyes, respectively. The postoperative spherical equivalent refraction was -0.03 ± 0.44 diopters (D) in Group 1 and -0.04 ± 0.31 D in Group 2. In Group 1, 83.3% of the eyes were within ± 0.5 D of the desired outcome, and 69.4% achieved an uncorrected distance visual acuity of 20/20 or better. In Group 2, these values were 95.5% and 86.4%, respectively. CONCLUSIONS: Lower pulse energy with tighter spots seems to reduce interface light scattering and improve refractive outcomes while also significantly increasing cap thickness.

Assessment of patient compliance in orthokeratology and analysis of influencing factors: a cross-sectional study.

BACKGROUND: Patient non-compliance, that is, failure to perform standard wear and care orthokeratology (ortho-k) lenses procedures, has been shown to be a major risk factor for contact lens-associated complications. Therefore, this study aimed to investigate the compliance with wear and care behaviors of ortho-k patients and analyze its influencing factors. METHODS: Patients who were successfully prescribed ortho-k lenses at the Eye Center of the Second Affiliated Hospital of Zhejiang University School of Medicine (ECSAHZU) were enrolled in the study. Patient compliance with wear and care behaviors was examined through a questionnaire. RESULTS: This study assessed 238 subjects. The subjects' ages ranged from 7 to 25 (mean ± SD, 11.3 ± 2.5) years. The compliance with wear and care behaviors was 19.7%, and the subjects' self-assessment compliance was 96.6%. The compliance rate of subjects wearing lenses for less than 1 year was higher than that of subjects wearing lenses for more than 1 year (p < 0.001). In the first year, the compliance rates of wearing experiences for less than 1 month, 1 month, 3 months, 6 months, and more than 6 months were 45, 29, 21.6, 20, and 27.6%, respectively, and there were no statistically significant differences in compliance among these periods (p = 0.314). No correlation was identified between compliance and age (r = - 0.061, p = 0.527) or sex (r = 0.114, p = 0. 751). There was no correlation between compliance and lens care operator (r = - 0.626, p = 0.151). CONCLUSIONS: The compliance of ortho-k patients was poor. After wearing ortho-k lenses for more than 1 year, compliance with wear and care behaviors declined. In clinical practice, measures should be taken to solve these problems and improve the safety of wearing ortho-k lenses.