Interplay between the Formation of Colloidal Clathrate and Cubic Diamond Crystals.

Controlling the valency of directional interactions of patchy particles is insufficient for the selective formation of target crystalline structures due to the competition between phases of similar free energy. Examples of such are stacking hybrids of interwoven hexagonal and cubic diamonds with (i) its liquid phase, (ii) arrested glasses, or (iii) clathrates, all depending on the relative patch size, despite being within the one-bond-per-patch regime. Herein, using molecular dynamics simulations, we demonstrate that although tetrahedral patchy particles with narrow patches can assemble into clathrates or stacking hybrids in the bulk, this behavior can be suppressed by the application of external surface potential. Depending on its strength, the selective growth of either cubic diamond crystals or empty sII clathrate cages can be achieved. The formation of a given ordered network depends on the structure of the first adlayer, which is commensurate with the emerging network.

On the selective formation of cubic tetrastack crystals from tetravalent patchy particles.

Achieving the formation of target open crystalline lattices from colloidal particles is of paramount importance for their potential application in photonics. Examples of such desired structures are the diamond, tetrastack, and pyrochlore lattices. Here, we demonstrate that the self-assembly of tetravalent patchy particles results in the selective formation of cubic tetrastack crystals, both in the bulk and in the systems subjected to external fields exerted by the solid substrate. It is demonstrated that the presence of an external field allows for the formation of well-defined single crystals with a low density of defects. Moreover, depending on the strength of the applied external field, the mechanism of epitaxial growth changes. For weakly attractive external fields, the crystallization occurs in a similar manner as in the bulk, since the fluid does not wet the substrate. Nonetheless, the formed crystal is considerably better ordered than the crystals formed in bulk, since the surface induces the ordering in the first layer. On the other hand, it is demonstrated that the formation of well-ordered cubic tetrastack crystals is considerably enhanced by the increase in external field strength, and the formation of the thick crystalline film occurs via a series of layering transitions.

Correction: Pursuing colloidal diamonds.

Correction for 'Pursuing colloidal diamonds' by Lukasz Baran et al., Nanoscale, 2023, 15, 10623-10633, https://doi.org/10.1039/D3NR01771K.

Pursuing colloidal diamonds.

The endeavor to selectively fabricate a cubic diamond is challenging due to the formation of competing phases such as its hexagonal polymorph or others possessing similar free energy. The necessity to achieve this is of paramount importance since the cubic diamond is the only polymorph exhibiting a complete photonic bandgap, making it a promising candidate in view of photonic applications. Herein, we demonstrate that due to the presence of an external field and delicate manipulation of its strength we can attain selectivity in the formation of a cubic diamond in a one-component system comprised of designer tetrahedral patchy particles. The driving force of such a phenomenon is the structure of the first adlayer which is commensurate with the (110) face of the cubic diamond. Moreover, after a successful nucleation event, once the external field is turned off, the structure remains stable, paving an avenue for further post-synthetic treatment.

Development and Validation of a Diabetic Retinopathy Risk Stratification Algorithm.

OBJECTIVE: Although diabetic retinopathy is a leading cause of blindness worldwide, diabetes-related blindness can be prevented through effective screening, detection, and treatment of disease. The study goal was to develop risk stratification algorithms for the onset of retinal complications of diabetes, including proliferative diabetic retinopathy, referable retinopathy, and macular edema. RESEARCH DESIGN AND METHODS: Retrospective cohort analysis of patients from the Kaiser Permanente Northern California Diabetes Registry who had no evidence of diabetic retinopathy at a baseline diabetic retinopathy screening during 2008-2020 was performed. Machine learning and logistic regression prediction models for onset of proliferative diabetic retinopathy, diabetic macular edema, and referable retinopathy detected through routine screening were trained and internally validated. Model performance was assessed using area under the curve (AUC) metrics. RESULTS: The study cohort (N = 276,794) was 51.9% male and 42.1% White. Mean (±SD) age at baseline was 60.0 (±13.1) years. A machine learning XGBoost algorithm was effective in identifying patients who developed proliferative diabetic retinopathy (AUC 0.86; 95% CI, 0.86-0.87), diabetic macular edema (AUC 0.76; 95% CI, 0.75-0.77), and referable retinopathy (AUC 0.78; 95% CI, 0.78-0.79). Similar results were found using a simpler nine-covariate logistic regression model: proliferative diabetic retinopathy (AUC 0.82; 95% CI, 0.80-0.83), diabetic macular edema (AUC 0.73; 95% CI, 0.72-0.74), and referable retinopathy (AUC 0.75; 95% CI, 0.75-0.76). CONCLUSIONS: Relatively simple logistic regression models using nine readily available clinical variables can be used to rank order patients for onset of diabetic eye disease and thereby more efficiently prioritize and target screening for at risk patients.

Quantification of risk factors for diabetic retinopathy progression.

AIMS: To determine the importance of blood sugar control, blood pressure, and other key systemic factors on the risk of progression from no retinopathy to various stages of diabetic retinopathy. METHODS: Restrospective cohort analysis of patients (N = 99, 280) in the Kaiser Permanente Northern California healthcare system with a baseline retina photographic screening showing no evidence of retinopathy and a minimum follow-up surveillance period of 3 years from 2008 to 2019. We gathered longitudinal data on diabetic retinopathy progression provided by subsequent screening fundus photographs and data captured in the electronic medical record over a mean surveillance of 7.3 ± 2.2 (mean ± SD) years. Progression from an initial state of no diabetic retinopathy to any of four outcomes was determined: (1) any incident retinopathy, (2) referable (moderate or worse) retinopathy, (3) diabetic macular edema, and (4) proliferative diabetic retinopathy. Multiple predictors, including age, race, gender, glycosylated hemoglobin (HbA1c), systolic blood pressure (SBP), cholesterol, chronic renal disease, and type of diabetes were investigated. RESULTS: Among modifiable risk factors, the average HbA1c had the strongest impact on the progression of diabetic retinopathy, followed by average SBP control and total cholesterol. Patients with an average HbA1c of 10.0% or greater (≥ 97 mmol/mol) had a risk ratio of 5.72 (95% CI 5.44-6.02) for progression to any retinopathy, 18.84 (95% CI 17.25-20.57) for referable retinopathy, 22.85 (95% CI 18.87-27.68) for diabetic macular edema, and 25.96 (95% CI 18.75-36.93) for proliferative diabetic retinopathy compared to those with an average HbA1c of 7.0% (53 mmol/mol) or less. Non-white patients generally had a higher risk of progression to all forms of diabetic retinopathy, while Asian patients were less likely to develop diabetic macular edema (HR 0.76, 95% CI 0.66-0.87). CONCLUSIONS: We confirm the critical importance of glucose control as measured by HbA1c on the risk of development of diabetic retinopathy.

Diabetic retinopathy screening using a virtual reading center.

AIMS: To summarize the effects of centralization of diabetic fundus photograph interpretation into a virtual reading center. METHODS: In 2016 Kaiser Permanente Northern California, a large, membership-based health plan with an ethnically and racially diverse population, centralized diabetic retinopathy screening into a virtual reading center. Retina screens were based on single field, 45-degree fundus photographs. We compared the accuracy of photography interpretation the year before centralization to the year after using masked reads performed by retina specialists of 1000 randomly selected screens from each time period. RESULTS: In all, 1902 patient screens with adequate quality images were included in the primary analysis. Images from pre-centralization screens were largely read by ophthalmologists (76.2%), while screens post-centralization were mainly read by optometrists (84.6%). Despite being interpreted by readers with lower levels of professional training, the sensitivity of screening increased from 43.9% (95% CI 38.0-49.8%) to 66.0% (95% CI 60.5-71.4%). CONCLUSION: A move to a centralized virtual reading center was associated with improved accuracy of diabetic retinopathy screening.

Good syndrome and other causes of cytomegalovirus retinitis in HIV-negative patients-case report and comprehensive review of the literature.

We describe a 65-year-old Thai woman who developed cytomegalovirus retinitis (CMVR) in the setting of Good syndrome-a rare, acquired partial immune deficiency caused by thymoma. The patient subsequently developed vitritis with cystoid macular edema (CME) similar to immune recovery uveitis (IRU) despite control of the retinitis with antiviral agents. A comprehensive review of the literature through December, 2014, identified an additional 279 eyes of 208 patients with CMVR in the absence of human immunodeficiency virus (HIV) infection. Including our newly reported case, 9 of the 208 patients (4.3 %) had Good syndrome. Twenty-one of the 208 patients (10.1 %) had CMVR related to intraocular or periocular corticosteroid administration. The remaining 178 patients (85.6 %) acquired CMVR from other causes. Within the subset of patients who did not have Good syndrome or did not acquire CMVR followed by intraocular or periocular corticosteroid administration, there were many other factors contributing to a decline in immune function. The most common included age over 60 years (33.1 %), an underlying malignancy (28.7 %), a systemic autoimmune disorder requiring systemic immunosuppression (19.1 %), organ (15.2 %) or bone marrow (16.3 %) transplantation requiring systemic immunosuppression, and diabetes mellitus (6.1 %). Only 4.5 % of the patients had no identifiable contributor to a decline in immune function. While the clinical features of CMVR are generally similar in HIV-negative and HIV-positive patients, the rates of moderate to severe intraocular inflammation and of occlusive retinal vasculitis appear to be higher in HIV-negative patients.

Ocular features of west nile virus infection in North America: a study of 14 eyes.

PURPOSE: To present a case series of ocular findings of West Nile virus infection (WNVI) in North America. DESIGN: Retrospective, noncomparative, observational case series. PARTICIPANTS: All patients were referred to the authors for WNVI with ocular involvement between the years 2002 and 2005. METHODS: Chart review was performed on all participants. All participants underwent complete ophthalmic evaluation during each examination, including best-corrected Snellen visual acuity measurement, tonometry, slit-lamp biomicroscopy of the anterior and posterior segments, and dilated fundus examination with indirect ophthalmoscopy. Fundus photography and fluorescein angiography were also performed on all eyes. Relevant ocular findings associated with WNVI were recorded and tabulated. MAIN OUTCOME MEASURES: The authors studied the characteristics, frequency, and locations of ocular lesions found in participants' eyes. RESULTS: There were 14 eyes (7 patients) with ocular West Nile virus lesions from 2002 to 2005. Average patient age was 58.4 years (range, 32-85 years). Ocular findings in descending order of frequency included multifocal chorioretinal target lesions in 12 eyes (85.7%), retinal hemorrhages in 7 eyes (50.0%), vitritis in 6 eyes (42.9%), chorioretinal linear streaks in 4 eyes (28.6%), perivascular sheathing and vasculitis in 4 eyes (28.6%), narrowed retinal vessels in 4 eyes (28.6%), disc edema in 4 eyes (28.6%), optic atrophy in 2 eyes (14.3%), vascular occlusion in 2 eyes (14.3%), and VIth nerve palsy in 1 eye (7.1%). Peripheral fundus lesions were found in all 14 eyes (100%), whereas posterior fundus lesions were found in 8 eyes (57.1%). Five patients (71.4%) were diabetic. Diabetic retinopathy was present in 7 eyes (70%). CONCLUSIONS: Multifocal choroiditis is the most common ocular manifestation associated with WNVI, with a typically benign clinical course. Less frequent ocular lesions, including optic neuritis and occlusive vasculitis, frequently induce persistent and likely permanent visual deficit. Diabetic patients and those older than 50 years of age are more vulnerable to the more severe features of WNVI, including more serious ocular lesions.

Characteristics of sixty myopic eyes with pre-laser in situ keratomileusis retinal examination and post-laser in situ keratomileusis retinal lesions.

PURPOSE: A survey of eyes with pre-laser in situ keratomileusis (LASIK) retinal examinations and characteristics of post-LASIK retinal breaks and retinal detachments (RDs). METHODS: A survey of worldwide vitreoretinal surgeons (424 physicians). Surveyed information included demographics, best-corrected visual acuity, degree of myopia, pre- and post-LASIK retinal findings, follow-up time, and treatment outcome. RESULTS: Sixty eyes with pre-LASIK retinal examinations developed post-LASIK retinal breaks and RDs. There was an average of 2.3 breaks per eye, yielding a total of 140 breaks in the 60 eyes. Forty eyes also had RDs besides the retinal breaks. Large percentages of eyes had substantial myopia (mean myopia, -9.5 +/- 5.8 diopters [D]) and complex vitreoretinal complications. Forty percent developed vitreoretinal complications within 6 months after LASIK. The 20 eyes that developed more extensive RDs (>3 clock hours) had a significantly higher mean myopia than did the 6 eyes that developed limited RD (< or = 3 clock hours) within 12 months after LASIK (-8.92 +/- 6.82 D versus -3.50 +/- 1.97 D, P = 0.03). There were significant statistical differences in distribution of retinal breaks and tears between the temporal and nasal quadrants (P < 0.001, P < 0.001, respectively, chi2, but not between the superior and inferior quadrants. CONCLUSION: Distributions of retinal breaks in this study were comparable with results found in non-LASIK eyes in young myopes. Treatment for post-LASIK vitreoretinal complications was highly successful. The vulnerability of such highly myopic eyes for vitreoretinal complications warrants their close monitoring.

Intravitreally injected human immunoglobulin attenuates the effects of Staphylococcus aureus culture supernatant in a rabbit model of toxin-mediated endophthalmitis.

OBJECTIVE: To determine whether human immunoglobulin attenuates the toxic effects of Staphylococcus aureus culture supernatant in a rabbit model of endophthalmitis. METHODS: Immunoglobulin binding to products of S aureus strain RN4220 was tested by Western blot analysis using known toxins (beta-hemolysin and toxic shock syndrome toxin-1) and a concentrated culture supernatant containing S aureus exotoxins (pooled toxin). To induce endophthalmitis, pooled toxin was injected into the rabbit vitreous. For immunoglobulin treatment, immunoglobulin and pooled toxin were either mixed and injected simultaneously or immunoglobulin was injected immediately after or 6 hours after pooled toxin injection. Severity of endophthalmitis was graded according to a 9-day course with clinical examination (slitlamp biomicroscopy or indirect ophthalmoscopy) and evaluation of histologic sections. RESULTS: The toxic effects of pooled toxin were markedly reduced when immunoglobulin was mixed with pooled toxin and injected simultaneously. Delayed injection of immunoglobulin diminished its ability to reduce toxicity. Clinical and histologic signs of toxicity were partially attenuated when immunoglobulin was injected immediately after pooled toxin, but only minimal clinically detectable reductions in toxicity were observed when immunoglobulin injection was delayed for 6 hours. CONCLUSION: Pooled human immunoglobulin can attenuate the toxic intravitreal effects of a concentrated culture supernatant containing S aureus exotoxins. Clinical Relevance Immunoglobulin may represent a novel adjuvant in the treatment of bacterial endophthalmitis. To optimize the potential therapeutic benefit, maximizing the mixture of immunoglobulin with bacterial products and early intervention are likely to be important.