Visual and Patient-Reported Outcomes of a Diffractive Trifocal Intraocular Lens Compared with Those of a Monofocal Intraocular Lens.

PURPOSE: To evaluate the effectiveness and safety of a trifocal intraocular lens (IOL), the TFNT00 (Alcon, Fort Worth, TX), versus a monofocal IOL, the SN60AT (Alcon). DESIGN: Food and Drug Administration-approved, prospective, multicenter, nonrandomized, parallel-group, assessor-masked, confirmatory trial. PARTICIPANTS: Patients enrolled were 22 years of age or older with a diagnosis of bilateral cataract with planned removal by phacoemulsification with a clear corneal incision. METHODS: Consented participants selected their preferred IOL, which was implanted sequentially into each eye of patients meeting eligibility criteria. MAIN OUTCOME MEASURES: The coprimary effectiveness outcomes were mean photopic monocular best-corrected distance visual acuity (BCDVA; 4 m) and distance-corrected near visual acuity (DCNVA; 40 cm) at 6 months after surgery. Secondary effectiveness outcomes included mean monocular distance-corrected intermediate visual acuity (DCIVA; 66 cm) and proportion of participants responding "never" to question 1 of the Intraocular Lens Satisfaction questionnaire (regarding frequency of spectacle use in the past 7 days). Safety outcomes included frequency of "severe" and "most bothersome" visual disturbances. RESULTS: Two hundred forty-three patients underwent cataract surgery with bilateral implantation of the TFNT00 (n = 129) or SN60AT (n = 114) and were followed up for 6 months. Noninferiority of TFNT00 to SN60AT in mean photopic monocular BCDVA (95% upper confidence limit of the difference was <0.1 logarithm of the minimum angle of resolution [logMAR] margin), and superiority in mean photopic monocular DCNVA (difference of 0.42 logMAR; P < 0.001) and DCIVA (difference of 0.26 logMAR; P < 0.001) were demonstrated. The proportion of patients never requiring glasses overall was superior for TFNT00 versus SN60AT (80.5% and 8.2%, respectively). Starbursts, halos, and glare were the most frequently rated severe symptoms with TFNT00; however, less than 5% of patients were very bothered at month 6. CONCLUSIONS: The TFNT00 exhibited superior monocular DCNVA and DCIVA to a spherical monofocal IOL, with comparable monocular BCDVA. Binocular visual acuity was 20/25 or better for distance to near (+0.5 D to -2.5 D), resulting in high levels of spectacle independence. Less than 5% of patients were very bothered by the photic visual disturbances associated with the TFNT00 at 6 months after surgery.

Universal Dynamics of Molecular Reorientation in Hybrid Lead Iodide Perovskites.

The role of organic molecular cations in the high-performance perovskite photovoltaic absorbers, methylammonium lead iodide (MAPbI3) and formamidinium lead iodide (FAPbI3), has been an enigmatic subject of great interest. Beyond aiding in the ease of processing of thin films for photovoltaic devices, there have been suggestions that many of the remarkable properties of the halide perovskites can be attributed to the dipolar nature and the dynamic behavior of these cations. Here, we establish the dynamics of the molecular cations in FAPbI3 between 4 K and 340 K and the nature of their interaction with the surrounding inorganic cage using a combination of solid state nuclear magnetic resonance and dielectric spectroscopies, neutron scattering, calorimetry, and ab initio calculations. Detailed comparisons with the reported temperature dependence of the dynamics of MAPbI3 are then carried out which reveal the molecular ions in the two different compounds to exhibit very similar rotation rates (≈8 ps) at room temperature, despite differences in other temperature regimes. For FA, rotation about the N···N axis, which reorients the molecular dipole, is the dominant motion in all phases, with an activation barrier of ≈21 meV in the ambient phase, compared to ≈110 meV for the analogous dipole reorientation of MA. Geometrical frustration of the molecule-cage interaction in FAPbI3 produces a disordered γ-phase and subsequent glassy freezing at yet lower temperatures. Hydrogen bonds suggested by atom-atom distances from neutron total scattering experiments imply a substantial role for the molecules in directing structure and dictating properties. The temperature dependence of reorientation of the dipolar molecular cations systematically described here can clarify various hypotheses including those of large-polaron charge transport and fugitive electron spin polarization that have been invoked in the context of these unusual materials.

Structural Evolution and Atom Clustering in ß-SiAlON: ß-Si6-zAlzOzN8-z.

SiAlON ceramics, solid solutions based on the Si3N4 structure, are important, lightweight structural materials with intrinsically high strength, high hardness, and high thermal and chemical stability. Described by the chemical formula ß-Si6-zAlzOzN8-z, from a compositional viewpoint, these materials can be regarded as solid solutions between Si3N4 and Al3O3N. A key aspect of the structural evolution with increasing Al and O (z in the formula) is to understand how these elements are distributed on the ß-Si3N4 framework. The average and local structural evolution of highly phase-pure samples of ß-Si6-zAlzOzN8-z with z = 0.050, 0.075, and 0.125 are studied here, using a combination of X-ray diffraction, NMR studies, and density functional theory calculations. Synchrotron X-ray diffraction establishes sample purity and indicates subtle changes in the average structure with increasing Al content in these compounds. Solid-state magic-angle-spinning 27Al NMR experiments, coupled with detailed ab initio calculations of NMR spectra of Al in different AlOqN4-q tetrahedra (0 ≤ q ≤ 4), reveal a tendency of Al and O to cluster in these materials. Independently, the calculations suggest an energetic preference for Al-O bond formation, instead of a random distribution, in the ß-SiAlON system.

Constructing Hierarchical Porous Zeolites via Kinetic Regulation.

Zeolites are crystalline inorganic solids with microporous structures, having widespread applications in the fields of catalysis, separation, adsorption, microelectronics, and medical diagnosis. A major drawback of zeolites is the mass transfer limitation due to the small size of the micropores (less than 1 nm). Numerous efforts have been dedicated to integrating mesopores with the microporous zeolite structures by using templating and/or destructive approaches. Here we provide a new strategy for hierarchical pore size zeolite synthesis, without using supramolecular or hard templates. The branching epitaxial growth behavior, as a result of aluminum-zoning, contributes to the formation of the hierarchical porous zeolite structures.

Manganese Tetraboride, MnB4: High-Temperature Crystal Structure, p-n Transition, (55)Mn NMR Spectroscopy, Solid Solutions, and Mechanical Properties.

The structural and electronic properties of MnB4 were studied by high-temperature powder X-ray diffraction and measurements of the conductivity and Seebeck coefficient on spark-plasma-sintered samples. A transition from the room-temperature monoclinic structure (space group P2(1)/c) to a high-temperature orthorhombic structure (space group Pnnm) was observed at about 650 K. The material remained semiconducting after the transition, but its behavior changed from p-type to n-type. (55)Mn NMR measurements revealed an isotropic chemical shift of -1315 ppm, confirming an oxidation state of Mn close to I. Solid solutions of Cr(1-x)Mn(x)B4 (two phases in space groups Pnnm and P2(1)/c) were synthesized for the first time. In addition, nanoindentation studies yielded values of (496±26) and (25.3±1.7) GPa for the Young's modulus and hardness, respectively, compared to values of 530 and 37 GPa obtained by DFT calculations.

Clinical performance of a hybrid presbyopia-correcting intraocular lens in patients undergoing cataract surgery in a multicenter trial.

PURPOSE: To compare the clinical performance of TECNIS Synergy intraocular lens (IOL), model ZFR00V, vs TECNIS IOL, model ZCB00, in cataract patients. SETTING: Multicenter clinical setting. DESIGN: Prospective, randomized, subject/evaluator-masked clinical trial. METHODS: Cataract patients aged ≥22 years were randomly assigned 1:1 to bilateral implantation with ZFR00V or ZCB00. Key end points at 6 months postsurgery included monocular and binocular visual acuities at 4 m, 66 cm, 33 cm, and/or 40 cm, binocular distance-corrected defocus testing, patient-reported outcomes, and safety. RESULTS: 272 patients were implanted with ZFR00V (135) or ZCB00 (137). At 6 months, 83/131 (63.4%) ZFR00V patients demonstrated 20/25 or better combined monocular distance-corrected vision at far, intermediate, or near, compared with 5/130 (3.8%) ZCB00 patients. ZFR00V demonstrated excellent binocular uncorrected vision at intermediate (0.022 logMAR) and distance-corrected vision at 40 cm (0.047 logMAR). Strong ZFR00V performance persisted under mesopic conditions (0.244 logMAR or ∼20/32 Snellen), where improvement over ZCB00 with distance-corrected vision at near was 3.5 lines. ZFR00V provided a broad range of functional vision (20/32 or better) through -3.5 diopters of defocus (29 cm). Most ZFR00V patients reported no spectacle wear overall (93.1%) or at all 4 viewing distances combined (87.8%), and 55.7% qualified as completely spectacle independent. Relatively low proportions of ZFR00V patients reported being very/extremely bothered by halos (13.7%), starbursts (11.5%), or night glare (8.4%). The safety profile was similar between IOL groups. CONCLUSIONS: TECNIS Synergy ZFR00V demonstrated improved intermediate and near vision, increased range of vision, and greater spectacle independence vs TECNIS monofocal ZCB00.

Performance of a Translucent Activator for LipiFlow Vectored Thermal Pulse (VTP) Treatment of Meibomian Gland Dysfunction.

Purpose: Investigator feedback was used to assess the clinical use of the LipiFlow® System with the new translucent Activator Clear to successfully complete LipiFlow® treatments. Patients and Methods: This was a prospective, open-label clinical investigation. A total of 88 eyes (44 subjects) were treated using the LipiFlow® System with the new Activator Clear. Subjects diagnosed with bilateral meibomian gland dysfunction (MGD) were enrolled in the study. Each investigator performed a complete LipiFlow® treatment with the translucent Activator on both eyes of each subject. Investigators completed a questionnaire assessing the clinical use of the Activator Clear on a 5-point scale (1 - very difficult or strongly disagree, 3 - neutral, 5 - very easy or strongly agree). Results: The new translucent Activator provided successful LipiFlow® treatments in 100% of cases, with 95% confidence interval of (96%, 100%). Additionally, the investigators agreed or strongly agreed that the translucent components of the Activator Clear made it easy to access and position the activator with confidence on the subject's eye. Conclusion: The overall investigators' impressions on usage and functionality of LipiFlow® System with the translucent Activator were very positive. The Activator Clear enables doctors with efficient and confident positioning around patient eyelids to ensure successful LipiFlow® treatment when used as indicated.

Molecular structure and dynamics at the interfaces within bulk heterojunction materials for solar cells.

The molecular structures within the interfaces of the bulk heterojunction material comprising regioregular-poly(3-hexylthiophene-2,5-diyl), rrP3HT, and C(60) or its soluble derivative, [6,6]-phenyl-C(61)butyric acid methyl ester, PCBM, have been studied by one- and two-dimensional nuclear magnetic resonance (NMR). The local structure within the interface was inferred from chemical shift (CS) data obtained from composite films (CFs) fabricated at room temperature (PCBMCF-RT and C(60)CF-RT) and from CFs that had been subsequently annealed at 150 degrees C for 30 min (PCBMCF-A150 and C(60)CF-150A). In PCBMCF-RT, the alkyl side chains of rrP3HT are close to the C(60) ball; C(60) is essentially 'wrapped' by the alkyl side chains. In PCBMCF-A150, the alkyl side chains self-assemble such that rrP3HT and PCBM are separated. The observation of well-defined splittings in the CS spectrum of the (13)C of C(60) in C(60)CF-A150 indicates a distortion from spherical symmetry. Measurements of the spin-lattice relaxation rate, 1/T(1), of C(60) imply local magnetic field fluctuations that arise from the dynamics of the C(60) distortion.

Structural analysis of hybrid titania-based mesostructured composites.

High-optical-quality titania-based mesostructured films with cubic or 2D-hexagonal symmetry were fabricated by combining trifluoroacetate (TFA)-modified titanium precursors with amphiphilic triblock poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) copolymers. The distribution, dynamics, and local environments of the TFA-modified titania, PEO, and PPO components of the hybrid were investigated. IR/Raman spectroscopy, in situ small-angle X-ray scattering, and transmission electron microscopy studies indicate that TFA coordinates the titanium center and forms a stable complex that is subsequently organized by the block copolymer species into ordered mesostructures. Solid-state NMR (19)F-->(1)H cross-polarization, (13)C{(1)H} two-dimensional heteronuclear correlation, and (1)H relaxation techniques were used to determine that PEO is predominantly incorporated within the TFA-modified titania, and that PPO environments encompass both microphase separated regions and interfacial regions composed of mixed PPO and TFA-modified titania. NMR (19)F multiple-quantum spin counting measurements suggest that -CF(3) groups of the trifluoroacetate ligands do not form clusters but instead randomly distribute within the inorganic component of the hybrid.

NMR analysis of surfaces and interfaces in 2-nm CdSe.

Solid-state NMR analysis on wurtzite 2-nm hexadecylamine-capped CdSe nanocrystals (CdSe-HDA) provides evidence of discrete nanoparticle reconstruction within the Se sublattice of the nanomaterial. The cadmium and selenium atoms are probed with (1)H-(113)Cd and (1)H-(77)Se cross-polarization magic angle spinning (MAS) experiments, which demonstrate five ordered selenium sites in the nanoparticle that can be assigned to contributions arising from different surface sites and a selenium site one layer down from the surface. Intriguingly, in these materials both HDA and thiophenol are observed to selectively bind to specific sites on the nanoparticle surface. 2D heteronuclear chemical shift correlation (HETCOR) experiments provide evidence for thiophenol selectively binding at surface vacancies. Analysis of the NMR provides a model of a 2-nm CdSe-HDA molecular surface.