Hints of Growth Mechanism Left in Supercrystals.

Supercrystals of DNA-functionalized nanoparticles are visualized in three dimensions using X-ray ptychographic tomography, and their reciprocal spaces are mapped with small-angle X-ray scattering in order to better understand their internal defect structures. X-ray ptychographic tomography reveals various types of defects in an assembly that otherwise exhibits a single crystalline diffraction pattern. On average, supercrystals composed of smaller nanoparticles are smaller in size than supercrystals composed of larger particles. Additionally, supercrystals composed of small nanoparticles are typically aggregated into larger "necklace-like" structures. Within these larger structures, some but not all pairs of connected domains are coherent in their relative orientations. In contrast, supercrystals composed of larger nanoparticles with longer DNA ligands typically form faceted crystals. The combination of these two complementary X-ray techniques reveals that the crystalline assemblies grow by aggregation of smaller assemblies followed by rearrangement of nanoparticles.

Short-Term Outcomes of Bimatoprost Sustained-Release Intracameral Implant in Glaucoma.

PRCIS: This retrospective study found a statistically significant reduction in mean intraocular pressure (IOP) and the number of medications after intracameral Bimatoprost sustained release (SR) injection in patients with glaucoma. A history of selective laser trabeculoplasty (SLT) did not impact treatment outcomes. PURPOSE: To determine outcomes of Bimatoprost SR on IOP and the number of topical IOP-lowering medications in patients with glaucoma. A secondary objective was to determine the outcomes of Bimatoprost SR in patients with a prior history of SLT. METHODS: Retrospective case series. One hundred eighteen eyes from 84 patients that received Bimatoprost SR by 6 glaucoma specialists at Wills Eye Hospital from March 2020 to September 2021 were examined. The intervention was a single injection of intracameral Bimatoprost SR. The main outcome measures included IOP and the number of medications. RESULTS: The most recent mean follow-up time for all eyes was 27.8 ± 18.6 weeks. The mean posttreatment IOP at the most recent follow-up of 16.6 ± 5.3 mm Hg was significantly lower than the mean under-therapy pretreatment IOP of 18.5 ± 5.7 mm Hg for all eyes ( P < 0.01). The mean posttreatment number of medications at the most recent follow-up of 1.3 ± 1.3 decreased compared with the number of pretreatment medications of 2.1 ± 1.4 for all eyes ( P < 0.01). Analysis of multilevel models controlling for demographic variables demonstrated a statistically significant reduction in IOP and number of medications posttreatment ( P < 0.01). A prior history of SLT (n = 54) had no impact on treatment for both IOP and the number of medications ( P > 0.1 for both). CONCLUSIONS: Intracameral Bimatoprost SR reduced IOP and decreased the number of medications. Prior history of SLT did not impact Bimatoprost SR treatment outcomes.

Outcomes of Selective Laser Trabeculoplasty After Prior Incisional Surgery for Open Angle Glaucoma.

PRCIS: This retrospective case series of patients with open angle glaucoma and prior trabeculectomy or tube shunt surgery found that selective laser trabeculoplasty (SLT) resulted in significant intraocular pressure (IOP) reductions in the intermediate follow-up period in select cases. PURPOSE: The purpose of this study was to assess the IOP-lowering effect and tolerability of SLT after prior trabeculectomy or tube shunt surgery. MATERIALS AND METHODS: Open angle glaucoma patients at Wills Eye Hospital who previously underwent incisional glaucoma surgery and subsequently received SLT between 2013 and 2018 were included, along with an age-matched control group. Baseline characteristics, procedural data, and post-SLT data were recorded at 1, 3, 6, 12 months, and most recent visit. The primary success of SLT treatment was defined as IOP reduction of 20% or greater without the use of additional glaucoma medications compared to pre-SLT IOP. Secondary success was defined as IOP reduction ≥20% with the use of additional glaucoma medications compared to pre-SLT IOP. RESULTS: There were 45 eyes in the study group and 45 eyes in the control group. In the study group, IOP decreased from a baseline of 19.5±4.7 mm Hg on 2.2±1.2 medications to 16.7±5.2 mm Hg ( P =0.002) on 2.2±1.1 glaucoma medications ( P =0.57). In the control group, IOP decreased from 19.5±4.2 mm Hg on 2.4±1.0 medications to 16.4±5.2 mm Hg ( P =0.003) on 2.1±1.3 medications ( P =0.36). There was no difference in IOP reduction or change in number of glaucoma medications after SLT at any postoperative visit between the 2 groups ( P ≥0.12 for all). Primary success rates at 12 months were 24.4% for the control group and 26.7% for the prior incisional glaucoma surgery group with no significant difference between the groups ( P =0.92). There were no persistent complications after SLT treatment in either group. CONCLUSION: SLT may effectively lower IOP in patients with open angle glaucoma who have had previous incisional glaucoma surgery and should be considered in select cases.

Morphology Engineering in Multicomponent Hollow Metal Chalcogenide Nanoparticles.

Hollow metal chalcogenide nanoparticles are widely applicable in environmental and energy-related processes. Herein, we synthesized such particles with large compositional and morphological diversity by combining scanning probe block copolymer lithography with a Kirkendall effect-based sulfidation process. We explored the influence of temperature-dependent diffusion kinetics, elemental composition and miscibility, and phase boundaries on the resulting particle morphologies. Specifically, CoNi alloys form single-shell sulfides for the synthetic conditions explored because Co and Ni exhibit similar diffusion rates, while CuNi alloys form sulfides with various types of morphologies (yolk-shell, double-shell, and single-shell) because Cu and Ni have different diffusion rates. In contrast, Co-Cu heterodimers form hollow heterostructured sulfides with varying void numbers and locations depending on synthesis temperature and phase boundary. At higher temperatures, the increased miscibility of CoS2 and CuS makes it energetically favorable for the heterostructure to adopt a single alloy shell morphology, which is rationalized using density functional theory-based calculations.

Arrays of Colloidal Single Crystals Engineered with DNA in Lithographically Defined Microwells.

Lithographically defined microwell templates are used to study DNA-guided colloidal crystal assembly parameters, including superlattice position, habit orientation, and size, in an effort to increase our understanding of the crystallization process. In addition to enabling the synthesis of arrays of individual superlattices in arbitrary predefined patterns, the technique allows one to study the growth pathways of the crystals via ex situ scanning electron microscopy. Importantly, a Volmer-Weber (VM) (island formation)-like growth mode is identified, which has been reproduced via simulations. Notably, both experiment and simulation reveal that the crystallites merge and reorient within the microwells that defined the crystal growth to form single-crystalline structures, an observation not common for VM pathways. The control afforded by this platform will facilitate efforts in constructing metamaterials from colloidal crystals as well as their integration into optical devices and applications.

Systematic Review of Prevalence Studies of Progressive Supranuclear Palsy and Corticobasal Syndrome.

Background: High-quality prevalence studies are important in estimating the burden of disease in a population, thus informing priority setting, resource allocation, delivery, and use of health services. Objectives: This study was undertaken to systematically review the methods and results of previous prevalence studies of progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) and make recommendations for future studies. Methods: A total of 2 authors independently identified original articles that described the prevalence of PSP or CBS using several comprehensive and overlapping search strategies, assessed study quality, and extracted relevant data. Descriptive and pooled analyses were performed as appropriate. Results: A total of 16 studies were identified in PSP and 9 studies in CBS, with highly heterogeneous methods of case definition, identification, and verification in identified studies. Few studies were deemed of necessary quality or methodological homogeneity to justify a full meta-analysis. In addition, few studies reported age- and sex-stratified results. The best 3 prevalence studies in PSP gave a pooled rate of 7.1 per 100,000 per year, whereas the pooled rate in 2 CBS studies was roughly 3 times lower at 2.3 per 100,000 per year. Based on crude rates, there was little evidence to suggest clear sex differences in the prevalence of PSP or CBS or that the prevalence of PSP had increased over time, but some evidence to suggest that prevalence may increase with increasing age. Conclusion: Given the paucity of prevalence studies in PSP and CBS, further high-quality prevalence studies are necessary.

Regioselective Deposition of Metals on Seeds within a Polymer Matrix.

We use scanning probe block copolymer lithography in a two-step sequential manner to explore the deposition of secondary metals on nanoparticle seeds. When single element nanoparticles (Au, Ag, Cu, Co, or Ni) were used as seeds, both heterogeneous and homogeneous growth occurred, as rationalized using the thermodynamic concepts of bond strength and lattice mismatch. Specifically, heterogeneous growth occurs when the heterobond strength between the seed and growth atoms is stronger than the homobond strength between the growth atoms. Moreover, the resulting nanoparticle structure depends on the degree of lattice mismatch between the seed and growth metals. Specifically, a large lattice mismatch (e.g., 13.82% for Au and Ni) typically resulted in heterodimers, whereas a small lattice mismatch (e.g., 0.19% for Au and Ag) resulted in core-shell structures. Interestingly, when heterodimer nanoparticles were used as seeds, the secondary metals deposited asymmetrically on one side of the seed. By programming the deposition conditions of Ag and Cu on AuNi heterodimer seeds, two distinct nanostructures were synthesized with (1) Ag and Cu on the Au domain and (2) Ag on the Au domain and Cu on the Ni domain, illustrating how this technique can be used to predictively synthesize structurally complex, multimetallic nanostructures.

Confined Growth of DNA-Assembled Superlattice Films.

We study the assembly of DNA-functionalized nanocubes under lateral confinement in microscale square trenches on a DNA-functionalized substrate. Microfocus small-angle X-ray scattering (SAXS) and scanning electron microscopy (SEM) are used to characterize the superlattices (SLs). The results indicate that nanocubes form simple-cubic SLs with square-prism morphology and a (100) out-of-plane orientation to maximize DNA bonding. In-plane, SLs align with the template, exposing their {100} side facets, and the degree of alignment depends on trench size. Interestingly, the distribution of in-plane orientations determined from SAXS and SEM do not agree, indicating that the internal and external structures of the SLs differ. To understand this discrepancy, X-ray ptychography is employed to image the internal structures of the SLs, revealing that SLs which appear to be single-crystalline in SEM may have subsurface grain boundaries, depending on trench size. SEM reveals that the SLs grow via nucleation and growth of randomly oriented domains, which then coalesce; this mechanism explains the observed dependence of alignment and defect structure on size. Interestingly, crystallization occurs via an unusual growth mode, whereby continuous SL layers grow on top of several misoriented islands. Overall, this work elucidates the effect of lateral confinement on the crystallization of DNA-functionalized nanoparticles and shows how X-ray ptychography can be used to gain insight into nanoparticle crystallization.

Large-Area, Highly Crystalline DNA-Assembled Metasurfaces Exhibiting Widely Tunable Epsilon-Near-Zero Behavior.

Metasurfaces prepared via bottom-up nanoparticle assembly enable the deliberate manipulation of light in the optical regime, resulting in media with various engineered optical responses. Here, we report a scalable method to grow highly crystalline 2D metasurfaces composed of colloidal gold nanocubes, over macroscopic areas, using DNA-mediated assembly under equilibrium conditions. Using an effective medium description, we predict that these plasmonic metasurfaces behave as dielectric media with high refractive indices that can be dynamically tuned by tuning DNA length. Furthermore, we predict that, when coupled with an underlying thin gold film, the real permittivity of these metasurfaces exhibits a crossover region between positive and negative values, known as the epsilon-near-zero (ENZ) condition, which can be tuned between 1.5 and 2.6 µm by changing DNA length. Optical characterization performed on the DNA-assembled metasurfaces reveals that the predicted optical properties agree well with the measured response. Overall, we propose an efficient method for realizing large-area plasmonic metasurfaces that enable dynamic control over optical characteristics. High-index and ENZ metasurfaces operating in the telecommunications regime could have significant implications in high-speed optical computing, optical communications, optical imaging, and other areas.

Low-Density 2D Superlattices Assembled via Directional DNA Bonding.

It is critical to assemble nanoparticles (NPs) into superlattices with controlled symmetries and spacings on substrates for metamaterials applications, where such structural parameters dictate their properties. Here, we use DNA to assemble anisotropic NPs of three shapes-cubes, octahedra, and rhombic dodecahedra-on substrates and investigate their thermally induced reorganization into two-dimensional (2D) crystalline films. We report two new low-density 2D structures, including a honeycomb lattice based on octahedral NPs. The low-density lattices favored here are not usually seen when particles are crystallized via other bottom-up assembly techniques. Furthermore, we show that, consistent with the complementary contact model, a primary driving force for crystallization is the formation of directional, face-to-face DNA bonds between neighboring NPs and between NPs and the substrate. Our results can be used to deliberately prepare crystalline NP films with novel morphologies.

Crystal structure engineering in multimetallic high-index facet nanocatalysts.

In the context of metal particle catalysts, composition, shape, exposed facets, crystal structure, and atom distribution dictate activity. While techniques have been developed to control each of these parameters, there is no general method that allows one to optimize all parameters in the context of polyelemental systems. Herein, by combining a solid-state, Bi-influenced, high-index facet shape regulation strategy with thermal annealing, we achieve control over crystal structure and atom distribution on the exposed high-index facets, resulting in an unprecedentedly diverse library of chemically disordered and ordered multimetallic (Pt, Co, Ni, Cu, Fe, and Mn) tetrahexahedral (THH) nanoparticles. Density functional theory calculations show that surface Bi modification stabilizes the {210} high-index facets of the nanoparticles, regardless of their internal atomic ordering. Moreover, we find that the ordering transition temperatures for the nanoparticles are dependent on their composition, and, in the case of Pt3Fe1 THH nanoparticles, increasing Ni substitution leads to an order-to-disorder transition at 900 °C. Finally, we have discovered that ordered intermetallic THH Pt1Co1 nanocatalysts exhibit a catalytic performance superior to disordered THH Pt1Co1 nanoparticles and commercial Pt/C catalysts toward methanol electrooxidation, highlighting the importance of crystal structure and atom distribution control on high-index facets in nanoscale catalysts.

The safety, efficacy and pharmaceutical quality of male enhancement nutraceuticals bought online: Truth versus claim.

OBJECTIVE: Nutraceutical products are widely used for their claimed therapeutic benefits. However, falsified or adulterated nutraceuticals present a major health threat to consumers. This study investigates the pharmaceutical quality, safety and anti-inflammatory effects of six male enhancement nutraceuticals that claim to be 100% natural. METHODS: Three batches of six male enhancement products were tested to detect the presence and levels of adulterants via high-performance liquid chromatography (HPLC). The pharmaceutical quality of the selected nutraceuticals was tested with near infrared spectroscopy (NIR) and SeDeM. The cytotoxic effects of these products on HepG2 cells were determined through cell proliferation (XTT) and lactate dehydrogenase (LDH) cytotoxicity assays. Lastly, the in vitro inflammatory effects of these products were investigated using murine J774 macrophages through cytokine release analysis. RESULTS: HPLC analysis detected the presence of sildenafil citrate, a vasodilator, and the active ingredient in Viagra and Revatio, in all batches of the products we analyzed. Amount of sildenafil citrate ranged from 0.45 mg to 51.85 mg among different batches. NIR assessment showed inter- and intra-batch heterogeneity in product composition. Results of the XTT and LDH assays showed significant cytotoxic effects of the analyzed products. XTT analysis revealed that the viability of HepG2 treated with tested products varied from 27.57% to 41.43%. Interestingly, the male enhancement products also showed anti-inflammatory effects. CONCLUSION: Despite their labeling as 100% natural, all products tested in this study contained levels of sildenafil citrate, which was not reported on the packaging. There was a lack of pharmaceutical uniformity among products of the same batch and across different batches. Additionally, the products we tested had cytotoxic effects. These study findings highlight the adulteration, poor quality and hazard of these nutraceuticals. Therefore, strict regulation of these products and standardization of the definition of nutraceuticals are urgently needed. Further, these falsely advertised products should be withdrawn from the market due to potential adverse effects on the health of their consumers.

Mie-Resonant Three-Dimensional Metacrystals.

Optical metamaterials, engineered to exhibit electromagnetic properties not found in natural materials, may enable new light-based applications including cloaking and optical computing. While there have been significant advances in the fabrication of two-dimensional metasurfaces, planar structures create nontrivial angular and polarization sensitivities, making omnidirectional operation impossible. Although three-dimensional (3D) metamaterials have been proposed, their fabrication remains challenging. Here, we use colloidal crystal engineering with DNA to prepare isotropic 3D metacrystals from Au nanocubes. We show that such structures can exhibit refractive indices as large as ∼8 in the mid-infrared, far greater than that of common high-index dielectrics. Additionally, we report the first observation of multipolar Mie resonances in metacrystals with well-formed habits, occurring in the mid-infrared for submicrometer metacrystals, which we measured using synchrotron infrared microspectroscopy. Finally, we predict that arrays of metacrystals could exhibit negative refraction. The results present a promising platform for engineering devices with unnatural optical properties.

Orbital Cellulitis Following Uncomplicated Glaucoma Drainage Device Surgery: Case Report and Review of Literature.

PURPOSE: Orbital cellulitis (OC) is a rare postoperative complication of glaucoma drainage device (GDD) implantation. To date, there have only been 10 reported cases of OC following GDD implantation. CASE REPORT: Here, we report a case of OC in a 57-year-old man who developed pain, proptosis, and limited extraocular motility two days after uneventful Ahmed FP7 implantation in the right eye. Contrast-enhanced computed tomography of the orbits demonstrated fat stranding and a small fluid collection, consistent with OC. He had minimal improvement with intravenous antibiotics and ultimately underwent GDD explantation. A systematic review of the literature showed that the development of OC following GDD implantation can occur in the early or late postoperative period. Immediate hospitalization with intravenous administration of broad-spectrum antibiotics is recommended. Explantation of the infected GDD is often required for source control. CONCLUSION: OC is a rare postoperative complication of GDD implantation. Prompt evaluation and treatment are required, often combined with GDD explantation.

Predictors of Success in Selective Laser Trabeculoplasty.

PURPOSE: Selective laser trabeculoplasty (SLT) is a common procedure to lower intraocular pressure (IOP) in patients with glaucoma. However, reports are conflicting regarding what factors contribute to SLT success. The purpose of this study was to determine predictors of SLT success. DESIGN: Retrospective case series. PARTICIPANTS: All patients treated with SLT between January 1, 2012, and June 30, 2018. METHODS: Baseline, demographic, procedural, and ophthalmic examination data were recorded at the time of first SLT treatment. Intraocular pressure and medication data were recorded at all follow-up visits. MAIN OUTCOME MEASURES: Selective laser trabeculoplasty success was defined as IOP decrease of 20% or more from baseline at the 3-month, 6-month, and 12-month follow-up visits. Eyes were considered to have failed and were censored when additional SLT or glaucoma surgery was performed. Patients were excluded if they had less than 3 months of follow-up. RESULTS: A total of 997 eyes from 677 patients were included in the study. Mean age was 70.2±11.5 years. Selective laser trabeculoplasty success was achieved in 227 eyes (22.8%), whereas 770 eyes (77.2%) did not meet success criteria. Intraocular pressure before SLT was 21.9±5.2 mmHg while taking 2.0±1.2 medications in eyes with successful SLT, compared with 19.0±5.0 mmHg (P < 0.0001) while taking 2.1±1.3 medications (P = 0.52) in eyes with SLT failure. At the 1-year follow-up, mean IOP in eyes with SLT success was 14.7±3.2 mmHg with 2.0±1.2 medications, compared with 16.3±4.7 mmHg (P = 0.008) with a mean of 1.9±1.3 medications (P = 0.37) in eyes with SLT failure. Eyes with SLT success more often showed greater angle pigment (P = 0.03). Age, glaucoma severity, total SLT power, type of glaucoma, severity of glaucoma, visual field mean defect, and retinal nerve fiber layer thickness were not found to correlate with success. No difference was found between the rate of success based on treatments before SLT, whether surgical or medical. CONCLUSIONS: In this large cohort of eyes undergoing SLT, greater IOP and angle pigment before SLT correlated positively with SLT success. Age, total SLT power, severity of glaucoma, and prior treatments were not associated with SLT success or failure.

High-Index-Facet Metal-Alloy Nanoparticles as Fuel Cell Electrocatalysts.

A method to introduce high-index facets into colloidally synthesized nanoparticles is used to produce compositionally uniform Pt-M (M = Ni, Co, and Cu) and Rh-M (M = Ni and Co) tetrahexahedral nanoparticles. The realization of this method allows for a systematic study of catalyst activity as a function of particle composition for various electrooxidation reactions of liquid fuels (formic acid, methanol, and ethanol). The individual contributions of their high-index facets, internal alloying of transition metals, and surface Bi modification to their electrocatalytic properties are experimentally explored, resulting in three key findings. First, the presence of high-index facets is favorable for improving the catalytic activity for all three classes of reactions studied. Second, the effect of transition metal alloying on catalytic activity differs from reaction to reaction. For methanol electrooxidation in an acid electrolyte, due to the contribution from surface Bi modification being negligible, transition metal alloying can significantly the improve overall catalytic efficiency. However, for the other studied reactions, where the surface Bi is highly favorable for improving catalytic activity, there is little influence from transition metal alloying. Finally, multimetallic tetrahexahedral particles have improved stabilities during prolonged operation compared to their monometallic counterparts due to the presence of the alloyed transition metal atoms.

Outcomes of Ahmed Glaucoma Valve Implantation With Viscoelastic Fill at Both Beginning and End of Surgery.

PRéCIS:: Intracameral injection of viscoelastic at the beginning of Ahmed FP7 implantation did not reduce early postoperative complication rates. PURPOSE: To evaluate early postoperative complication rates after a modified technique in which the anterior chamber (AC) is filled with viscoelastic at the beginning of Ahmed FP7 implantation before conjunctival peritomy. SUBJECTS AND METHODS: A retrospective chart review was performed of eyes that underwent Ahmed FP7 implantation with or without viscoelastic fill to ~20 mm Hg by finger tension by a single surgeon (M.R.M). Viscoelastic prevented the AC from becoming shallow at any time during surgery, and additional viscoelastic was injected into the AC at the end of surgery to achieve a final intraocular pressure (IOP) of 20 mm Hg. RESULTS: A total of 159 eyes of 159 patients were included. Mean age was 76.4±10.4 years. Mean preoperative IOP was 30.3±9.7 mm Hg on 2.7±1.2 glaucoma medications. On postoperative day 1, there was an IOP spike ≥30 mm Hg in 0% of patients. Within the first postoperative month, hypotony (<5 mm Hg) occurred in 19 (21.8%) eyes that received viscoelastic fill compared with 5 (13.2%) eyes that did not receive viscoelastic fill (P=0.26). During the early postoperative period (≤3 mo), there was no difference in AC depth, microhyphema, choroidal effusion, or leakage between the 2 groups (P≥0.30 for all). There was a higher rate of layered hyphemas in the viscoelastic-fill group at postoperative week 1 (P=0.01). At 3-month follow-up, mean IOP was 14.9±5.5 mm Hg on 1.6±0.8 medications in the viscoelastic-fill group and 16.0±5.2 mm Hg on 1.0±1.2 medications in the nonviscoelastic-fill group (IOP P=0.35). Compared with baseline, change in IOP at 3 months was similar between both groups (P=0.15). Rates of additional medications and procedures did not differ between the 2 groups at any postoperative visit. CONCLUSIONS: Early intracameral injection of viscoelastic during Ahmed glaucoma valve implantation did not reduce early postoperative complication rates.

Multimetallic High-Index Faceted Heterostructured Nanoparticles.

Multimetallic heterostructured nanoparticles with high-index facets potentially represent an important class of highly efficient catalysts. However, due to their complexity, they are often difficult to synthesize. Herein, a library of heterostructured, multimetallic (Pt, Pd, Rh, and Au) tetrahexahedral nanoparticles was synthesized through alloying/dealloying with Bi in a tube furnace at 900-1000 °C. Electron microscopy and selected area diffraction measurements show that the domains of the heterostructured nanoparticles are epitaxially aligned. Although nanoparticles formed from Au alone exhibit low-index facets, Pt and Au form PtAu heterostructured nanoparticles with high-index facets, including domains that are primarily made of Au. Furthermore, the alloying/dealloying of Bi occurs at different rates and under different conditions within the heterostructured nanoparticles. This influences the types of architectures observed en route to the final high-index state, a phenomenon clearly observable in the case of PdRhAu nanoparticles. Finally, scanning probe block copolymer lithography was used in combination with this synthetic strategy to control nanoparticle composition in the context of PtAu nanoparticles (1:4 to 4:1 ratio range) and size (15 to 45 nm range).