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This work presents the preparation of a series of [(PbSe)1+δ]4[TiSe2]4 isomers via a low temperature synthesis approach that exploits precursor nanoarchitecture to direct formation of specific isomers. The targeted isomers formed even when the precursors did not have the correct amount of each element to make a unit cell from each repeating sequence of elemental layers deposited. This suggests that the exact composition of the precursors is less important than the nanoarchitecture in directing the formation of the compounds. The as-deposited diffraction data show that the isomers begin to form during the deposition, and Ti2Se, in addition to PbSe and TiSe2, are present in the specular diffraction patterns. HAADF-STEM images reveal impurity layers above and below an integer number of targeted isomer unit cells. The structural data suggest that Ti2Se forms as Se is deposited on the initial Ti layers and remains throughout isomer self-assembly. During growth, the isomers deplete the local supply of Ti and Pb, creating diffusion gradients that drive additional cations toward the growth front, which leaves surface impurity layers of TiSe2 and TiO2 after the supply of Pb is exhausted. The deposited stacking sequences direct formation of the targeted isomers, but fewer repeating units form than intended due to the lack of material per layer in the precursor and formation of impurity layers. All isomers have negative Hall and Seebeck coefficients, indicating that electrons are the majority carrier. The carrier concentration and conductivity of the isomers increase with the number of interfaces in the unit cell, resulting from charge donation between adjacent layers. The opposite variation of the carrier concentration and mobility with temperature result in minima in the resistivity between 50 and 100 K. The very weak temperature dependence of the carrier concentration likely results from changes in the amount of charge transfer between the layers with temperature.

Background A balance between autonomy and supervision can be difficult to obtain in medical education. In this study, we sought to determine whether the presence and level of supervision of ophthalmology resident outpatient clinic correlates with metrics of resident success, professionalism and stress. Methods A survey was emailed to all US ophthalmology program directors requesting it be forwarded to PGY4 residents. Questions included whether their program provided a resident-hosted outpatient clinic, and if so, whether residents were mandated to discuss every patient with faculty. Residents were assigned to three categories based on this question (0: no clinic, 1: mandated faculty input, 2: discretionary faculty input). Success metrics included numbers of manuscripts submitted, OKAP scores and success in obtaining fellowships. Professionalism metrics included rating comfort obtaining informed consent, breaking bad news, managing time in clinic, and confidence in providing care in various settings. Residents affirming participation in a continuity clinic also provided perceptions of the level of supervision and how the clinic affected stress. Results Category 1 residents perceived somewhat too much supervision, while category 2 residents felt that they had somewhat insufficient supervision. The majority of residents in either category did not feel that the continuity clinic affected their overall stress, although those who reported a change in stress usually indicated that the presence of the clinic increased stress. There were no other statistically significant differences between the responses from any category. Conclusions The presence of a resident-hosted continuity clinic neither adds nor detracts from the success or sense of professionalism of ophthalmology residents. However, when such a clinic is present, the degree of supervision appears to correlate inversely with resident perception of autonomy. These results suggest that the decision of a training program to offer a clinic hosted by residents offering comprehensive continuity care can be informed primarily by faculty and trainee philosophy and personal preferences without comprising education quality, clinical efficiency, residents’ perception of stress or their success in fellowship matching. Electronic supplementary material The online version of this article (10.1186/s12909-019-1620-0) contains supplementary material, which is available to authorized users.

This work presents the preparation of a series of [(PbSe)

Importance The description of racial and ethnic data in human trials is relatively unregulated, leading to potential confusion with and inconsistent reporting of these data. Objective To determine the frequency and use of racial and ethnic data in the ophthalmology literature in 2019. Design, Setting, and Participants This cross-sectional study included all full-length human studies published between January and December 2019 in theAmerican Journal of Ophthalmology,JAMA Ophthalmology, andOphthalmology. Main Outcomes and Measures Whether race or ethnicity was included in the data or analysis, how the categorization was described in the methods and results, specific racial and ethnic categories used, and whether and how the categories were determined. Results A total of 547 articles were identified during the study period, 484 (88% ± 2.7%) of which reported background demographic information, including patient age and sex. Only 233 (43% ± 4.1%) reported race and/or ethnicity. Of those articles, 72 (31% ± 5.9%) categorized it as race, 51 (22% ± 5.3%) ethnicity, 56 (24% ± 5.4%) race/ethnicity, 21 (9% ± 3.7%) race and ethnicity, 12 (5% ± 3.0%) descent, 12 (5% ± 2.9%) population, and 5 (2% ± 2.0%) ancestry; in 21 (9% ± 3.8%) it was not defined. Only 30 studies (13% ± 4.4%) described how it was determined in the methods or results, most frequently by self-report (77% ± 3.9%). A total of 78 races and/or ethnicities were defined. Conclusions and Relevance While most articles during the study period reported background demographic information, few included race and ethnicity and only a fraction of those described how these data were determined. The categories used were heterogeneous and often inconsistent. These findings suggest the need for increased and more standardized reporting of ethnic and racial demographic data in the ophthalmology literature.

Solid-state reaction kinetics on atomic length scales have not been heavily investigated due to the long times, high reaction temperatures, and small reaction volumes at interfaces in solid-state reactions. All of these conditions present significant analytical challenges in following reaction pathways. Herein we use in situ and ex situ X-ray diffraction, in situ X-ray reflectivity, high-angle annular dark field scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy to investigate the mechanistic pathways for the formation of a layered (Pb0.5Sn0.5Se)1+δ(TiSe2)m heterostructure, where m is the varying number of TiSe2 layers in the repeating structure. Thin film precursors were vapor deposited as elemental-modulated layers into an artificial superlattice with Pb and Sn in independent layers, creating a repeating unit with twice the size of the final structure. At low temperatures, the precursor undergoes only a crystallization event to form an intermediate (SnSe2)1+γ(TiSe2)m(PbS...

Preparing homologous series of compounds allows chemists to rapidly discover new compounds with predictable structure and properties. Synthesizing compounds within such a series involves navigating a free energy landscape defined by the interactions within and between constituent atoms. Historically, synthesis approaches are typically limited to forming only the most thermodynamically stable compound under the reaction conditions. Presented here is the synthesis, via self-assembly of designed precursors, of isocompositional incommensurate layered compounds [(BiSe)1+δ] m[TiSe2] m with m = 1, 2, and 3. The structure of the BiSe bilayer in the m = 1 compound is not that of the binary compound, and this is the first example of compounds where a BiSe layer thicker than a bilayer in heterostructures has been prepared. Specular and in-plane X-ray diffraction combined with high-resolution electron microscopy data was used to follow the formation of the compounds during low-temperature annealing and the subsequent decomposition of the m = 2 and 3 compounds into [(BiSe)1+δ]1[TiSe2]1 at elevated temperatures. These results show that the structure of the precursor can be used to control reaction kinetics, enabling the synthesis of kinetically stable compounds that are not accessible via traditional techniques. The data collected as a function of temperature and time enabled us to schematically construct the topology of the free energy landscape about the local free energy minima for each of the products.

Solid-state reaction kinetics on atomic length scales have not been heavily investigated due to the long times, high reaction temperatures, and small reaction volumes at interfaces in solid-state reactions. All of these conditions present significant analytical challenges in following reaction pathways. Herein we use in situ and ex situ X-ray diffraction, in situ X-ray reflectivity, high-angle annular dark field scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy to investigate the mechanistic pathways for the formation of a layered (Pb

Daniel B Moore,1 Rebecca F Neustein,2 Sarah K Jones,1 Alan L Robin,3 Kelly W Muir1,4 1Duke Eye Center, Duke University Medical Center, Durham, NC, 2Emory School of Medicine, Atlanta, GA, 3Department of Ophthalmology, Johns Hopkins School of Medicine and International Health, Bloomberg School of Public Health, Baltimore, MD, 4Health Services Research & Development, Durham VA Medical Center, Durham, NC, USA Abstract: As they grow older, most children with glaucoma must eventually face the transition to self-administering medications. We previously reported factors associated with better or worse medication adherence in children with glaucoma, using an objective, electronic monitor. Utilizing the same data set, the purpose of the current study was to determine whose report (the caregiver’s or the child’s) corresponded better with electronically monitored adherence. Of the 46 participants (22 girls), the mean age of children primarily responsible, and caregiver primarily responsible for medication administration was 15±2 and 10±2 years, respectively. For the children whose caregiver regularly administered the eyedrops, the caregiver’s assessment of drop adherence was associated with measured adherence (P=0.012), but the child’s was not (P=0.476). For the children who self-administered eyedrops, neither the child’s (P=0.218) nor the caregiver’s (P=0.395) assessment was associated with measured percent adherence. This study highlights potential errors when relying on self-reporting of compliance in patients and caregivers with pediatric glaucoma, particularly when the child is responsible for administering their own eyedrops. Frank discussions about the importance of medication adherence and how to improve compliance may help both the child and caregiver better communicate with the treating provider. Keywords: glaucoma, children, adherence

A series of (BiSe)1+δ(TiSe2)n compounds where n was varied from two to four were synthesized and electrically characterized to explore the extent of charge transfer from the BiSe layer to the TiSe2 layers. These kinetically stable heterostructures were prepared using the modulated elemental reactants (MER) method, in which thin amorphous elemental layers are deposited in an order that mimics the nanostructure of the desired product. X-ray diffraction (XRD), X-ray area diffraction, and scanning transmission electron microscopy (STEM) data show that the precursors formed the desired products. Specular diffraction scans contain only 00l reflections, indicating that the compounds are crystallographically aligned with the c-axis perpendicular to the substrate. The c-axis lattice parameter increases by 0.604(3) nm with each additional TiSe2 layer. In-plane diffraction scans contain reflections that can be indexed as the (hk0) of the BiSe and TiSe2 constituents. Area diffraction scans are also consistent with th...

A basic summary of thermoelectric principles is presented in a historical context, following the evolution of the field from initial discovery to modern day high-zT materials. A specific focus is placed on nanocomposite materials as a means to solve the challenges presented by the contradictory material requirements necessary for efficient thermal energy harvest. Misfit layer compounds are highlighted as an example of a highly ordered anisotropic nanocomposite system. Their layered structure provides the opportunity to use multiple constituents for improved thermoelectric performance, through both enhanced phonon scattering at interfaces and through electronic interactions between the constituents. Recently, a class of metastable, turbostratically-disordered misfit layer compounds has been synthesized using a kinetically controlled approach with low reaction temperatures. The kinetically stabilized structures can be prepared with a variety of constituent ratios and layering schemes, providing an avenue to systematically understand structure-function relationships not possible in the thermodynamic compounds. We summarize the work that has been done to date on these materials. The observed turbostratic disorder has been shown to result in extremely low cross plane thermal conductivity and in plane thermal conductivities that are also very small, suggesting the structural motif could be attractive as thermoelectric materials if the power factor could be improved. The first 10 compounds in the [(PbSe)1+δ]m(TiSe2)n family (m, n ≤ 3) are reported as a case study. As n increases, the magnitude of the Seebeck coefficient is significantly increased without a simultaneous decrease in the in-plane electrical conductivity, resulting in an improved thermoelectric power factor.

To evaluate optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) measurements in patients with active and quiescent uveitis with and without glaucoma and compare results to the published age-adjusted normative data.Comparative, retrospective pilot study.Consecutive patients with uveitis who underwent OCT RNFL measurements between December 2011 and October 2012 were identified: 76 uveitic eyes without glaucoma and 135 uveitic eyes with glaucoma.We conducted OCT of the RNFL.Global and sectoral RNFL thickness measurements.In 19 nonglaucomatous, uveitic eyes with active inflammation, mean global and all sectoral RNFL measurements were greater than the normative 95th percentile. The mean global RNFL OCT measurement was 140.5 microns in such eyes compared with 107.8 microns in the 57 nonglaucomatous, quiescent, uveitic eyes (P=0.008). These measurements were significantly higher than the average of 95.3 microns reported in normal eyes (P0.001). All mean sectoral measurements except superonasal were significantly higher in active compared with quiescent uveitic eyes (P=0.002-0.05). In glaucomatous eyes with both quiescent and active uveitis, the mean global RNFL measurements on OCT were 92.3 and 95.7 microns, respectively. These measurements were significantly higher than the mean global RNFL thickness (65.3 microns) reported in eyes with the same stage (moderate) of nonuveitic glaucoma.Uveitis is a major confounding factor in assessing the thickness of the RNFL. A significant thickening of the RNFL was found in patients with active uveitis and a greater RNFL thickness than anticipated in patients with uveitic glaucoma. These data raise concerns about the comparative value of RNFL scans as a method to detect and monitor glaucoma in uveitic eyes.

Preparing homologous series of compounds allows chemists to rapidly discover new compounds with predictable structure and properties. Synthesizing compounds within such a series involves navigating a free energy landscape defined by the interactions within and between constituent atoms. Historically, synthesis approaches are typically limited to forming only the most thermodynamically stable compound under the reaction conditions. Presented here is the synthesis, via self-assembly of designed precursors, of isocompositional incommensurate layered compounds [(BiSe)

Synthesis and electrical properties of kinetically stabilized (PbSe)1+δ(TiSe2)n thin-film intergrowths are reported for 1 ≤ n ≤ 18. A linear increase in the c-lattice parameter of the intergrowth is observed as n is increased and the slope is consistent with the inclusion of an additional TiSe2 structural unit as n is incremented by 1 and the observed intercept is consistent with the expected thickness of a PbSe bilayer. The charge donated to the TiSe2 constituent from the PbSe is diluted across more layers as n is increased, leading to a systematic increase in the Seebeck coefficient. The room temperature resistivity values of the reported compounds are all on the order of 10−5 Ω m and depend on defect densities that affect the mobility, making the magnitude of the resistivity less sensitive to n. The temperature dependence is metallic for large n, with a slight upturn at low temperatures due to localization of carriers for small n values. The power factor increases with n, including the highest reported for chalcogenide misfit layered and related compounds, showing that nanostructuring and modulation doping are an effective means of tuning the power factor of thermoelectric intergrowth materials. Since these compounds have very low thermal conductivity due to structural anisotropy and misregistration between intergrowth constituents, this suggests that varying their nanoarchitecture is a promising approach to obtain high values of zT.

Background The purpose of this study is to evaluate the number of eyedrops available per bottle of a variety of commonly prescribed glaucoma medications. Methods Six bottles of each glaucoma medication were tested: three each in the vertical and horizontal orientations. Bottles were housed in a customized force gauge apparatus designed to mimic ballpoint fingertip contact with a bottle. At a standard rate, all drops were expressed from each bottle and counted with an automated drop counter. Simultaneously, bottle volume was measured and drop size and number were also estimated. The main outcome measures were: total number of drops, volume per bottle and drops per milliliter (mL) of glaucoma medication. Results A total of 192 bottles from 32 bottle designs and manufacturers were tested. Twenty-two of the 32 bottle designs had a significantly different mean number of drops in the vertical and horizontal positions, with 10 designs have more drops dispensed in the horizontal orientation and 12 in the vertical orientation. Six of the 32 bottle designs had a significantly different mean total bottle volume in the vertical and horizontal positions, with all designs having greater volume in the vertical position. An adjusted ratio of mean number of drops/mean bottle volume demonstrated a range from 20.9 drops/mL to 40.8 drops/mL. Conclusions There is significant variability in drops and volume available per bottle of glaucoma medication depending on both the bottle position and manufacturer. These data point to the need for circumspection in prescribing glaucoma medications and caution in evaluating therapeutic outcomes.

(SnSe)1.2TiSe2 was found to self-assemble from a precursor containing modulated layers of Sn–Se and Ti–Se over a surprisingly large range of layer thicknesses and compositions. The constituent lattices form an alternating layer superstructure with rotational disorder present between the layers. This compound was found to have the highest Seebeck coefficient measured for analogous TiX2 containing misfit layered compounds to date, suggesting potential for low-temperature thermoelectric applications. Electrical characterization suggests that electrons transferred from SnSe to TiSe2 are responsible for the higher carrier concentration observed relative to bulk TiSe2. The transfer of charge from one constituent to the other may provide a mechanism for doping layered dichalcogenides for various applications without negatively affecting carrier mobility.

Telluride misfit layer compounds are reported for the first time. These compounds were synthesized using a novel approach of structurally designing a precursor that would form the desired product upon low-temperature annealing, which allows the synthesis of kinetically stable products that do not appear on the equilibrium phase diagram. Four new compounds of the [(PbTe)1.17]m(TiTe2)n family are reported, and their structures were examined by a variety of X-ray diffraction techniques.

Purpose To evaluate the risk factors for and frequency of an acute intraocular pressure (IOP) elevation (spike) after phacoemulsification in patients with glaucoma. Setting Academic glaucoma clinics and operating rooms. Design Retrospective case series. Methods Charts of consecutive glaucoma patients without previous incisional glaucoma surgery having phacoemulsification by the same surgeon between August 1996 and July 2012 were reviewed to obtain demographic information, preoperative glaucoma medications, severity and treatment measures, intraoperative course, and postoperative outcomes. A postoperative IOP spike was defined as IOP greater than 50% above baseline IOP. Main outcome measures were the number of eyes with a postoperative IOP spike and risk factors associated with an IOP spike after phacoemulsification. Results Of 271 eyes (271 patients) included in the study, 45 (17%) had an IOP spike. Risk factors for postoperative IOP spike by multivariate analysis included longer axial length (AL) or associated characteristics (wider angle grade on gonioscopy, deeper anterior chamber, and male sex), higher number of preoperative IOP-lowering medications, previous laser trabeculoplasty, and lack of postoperative oral acetazolamide. One eye (0.4%) required trabeculectomy during the 90-day postoperative period. Conclusions A significant proportion of glaucoma patients having phacoemulsification had an IOP spike. Patients requiring a higher number of IOP-lowering medications or laser trabeculoplasty for IOP control preoperatively and those with a greater AL should be treated more aggressively with IOP-lowering medication in the immediate postoperative period. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Background. Optic disk hemorrhage is known to be a risk factor for glaucoma progression. Cataract surgery by phacoemulsification results in large intraocular pressure fluctuations. We aim to investigate whether phacoemulsification is associated with optic disc hemorrhage in patients with glaucoma. Methods. This is a retrospective review of consecutive university clinic based glaucoma patients undergoing phacoemulsification alone, with at least 3 visits in the year before and at least 5 visits in the year following phacoemulsification. The presence of optic disk hemorrhage was evaluated with slit lamp biomicroscopy at each clinic visit prior to and following phacoemulsification. Results. We evaluated 158 eyes of 158 subjects; 15 (9.5%) had ODH noted at least once during the 2-year study period. Four eyes had ODH identified on postoperative day 1, for a cross-sectional prevalence of 2.5%. Fourteen ODH episodes were noted preoperatively versus 12 episodes postoperatively (P=0.68). Aspirin use was associated with ODH (P=0.015). Conclusions. Our cross-sectional study found a prevalence of ODH immediately after CE that was similar to other published rates, and our longitudinal study did not find an increase in ODH in the year after phacoemulsification when compared to the year prior to surgery.

We introduced 250 alligator snapping turtles (Macrochelys temminckii) originating from a turtle farm in Arkansas into six pools adjacent to the Washita River in Johnston, Bryan, and Marshall counties, Oklahoma. Additionally, we released 16 captive-bred and reared juvenile turtles. We used radiotelemetry and mark-recapture to monitor dispersal of turtles, selection of microhabitat, and patterns of movement. We placed transmitters on 16 adult turtles from Arkansas and 16 captive-bred juveniles 2–4 years old. We recorded 198 locations of 32 individuals by radiotelemetry between May 2007 and August 2008. We recaptured 45 turtles one-five times using hoop nets employed for 501 trap-nights. We compared movement and selection of habitat between sexes and age classes for the parameters water depth, bottom temperature, turbidity, and canopy cover. Adults and juveniles chose shallower depths with more canopy than available randomly. Additionally, adults chose greater depths than did juveniles, and juvenile...

Synthesis and structural characterization of a turbostratically disordered polymorph of (PbSe)1.18(TiSe2)2 is reported. The structure of this compound consists of an intergrowth between one distorted rock salt structured PbSe bilayer and two transition metal dichalcogenide structured Se–Ti–Se trilayers. In addition to the lattice mismatch, there is extensive rotational disorder between these constituents. The electrical resistivity of (PbSe)1.18(TiSe2)2 is a factor of 9 lower at room temperature, and the Seebeck coefficient is almost double that reported for the crystalline misfit layered compound analogue.

Transition metal dichalcogenides, TSe2 with T = V, Ti, and Ta, were synthesized through self-assembly of designed amorphous precursors. All three compounds formed with the expected layered transiti...

To determine the force requirements to dispense a single drop from commonly prescribed brand and generic topical glaucoma medications and correlate these findings with pinch strength in a representative patient population.Four bottles of each medication were tested: 2 in the vertical and 2 in the horizontal orientation. Bottles were housed in a customized force gauge apparatus designed to mimic ballpoint fingertip contact with a bottle tip. For all bottles, each of the first 10 dispensed drops was tested and then tests were performed in increments of 10 until the bottle was empty. For each tested drop, the maximum force and displacement were electronically measured. Concurrently, maximum pinch strength was measured on consecutive glaucoma patients.A total of 84 bottles from 21 bottle designs were tested. There was significant variability across the designs, with roughly a 7-fold (0.67 to 4.49 kgf) and 4-fold (0.81 to 3.00 kgf) difference in force requirements in the vertical and horizontal positions, respectively. Of 53 enrolled patients in the glaucoma clinic, the mean pinch strength was 5.05 (range, 1.23 to 10.4 kgf) and 4.82 (range, 1.47 to 10.67 kgf) kgf for the right and left hands, respectively.There is statistically significant variability in the force required to squeeze a drop from common glaucoma medications, and a representative sampling of clinic patients suggests that many likely struggle with the force requirements of several bottle designs. These data further support standardization of topical glaucoma drug delivery and design.

A homologous series of quasi-2D ([PbSe]1+δ)m(TiSe2)m nanolayered heterostructures are prepared via self-assembly of designed precursors with 1 ≤m≤ 4 and their structures and properties investigated. All heterostructures have the same global composition but vary in their interface density. X-ray diffraction and electron microscopy studies show that the structures consist of rock salt structured PbSe layers alternating with TiSe2 layers, and that grain size increases with m. The compounds are all metallic with upturns in resistivity at low temperature suggesting electron localization, with room temperature resistivity of 1-3 10(-5)Ω m, negative Hall coefficients and Seebeck coefficients between -50 and -100 μV K(-1). A decrease in the mobile carrier concentration with temperature is observed for all m and the rate increases with increasing low-dimensionality. Decreasing the interface density also decreases the average carrier concentration while increasing the electron mobility. The Seebeck coefficients systematically increase in magnitude as m is increased, but the net effect to the power factor is small due to a compensating increase in resistivity. The observed transport behavior is not described by the simple rigid band models with charge transfer between constituents used previously. Charge exchange between constituents stabilizes the intergrowth, but also introduces mobile carriers and interfacial band bending that must play a role in the transport behavior of the heterostructures. As chemical potentials equilibrate in high m heterostructures there is a decrease in total coulombic stabilization as there are fewer interfaces, so m = 1 is likely to be most stable. This rationalizes why the structurally similar misfit layer compounds with m = 1 are often the only intergrowths that can be prepared. Charge transfer and band bending at interfaces should occur in other heterostructures with similar type II broken-gap band alignments and are important considerations regarding both their stability and transport properties.

Targeted heterostructures containing intergrown two dimensional (2D) layers of 3 different constituent layers, SnSe2, PbSe and TiSe2, were prepared by controlling the composition and sequence of elemental bilayers within a designed precursor. Varying the structure of the precursor enabled the number of structural units of each constituent and the sequence of crystalline 2D layers to be precisely controlled. The stacking of the 2D layers, their structures, and the segregation of the elements between them were determined using X-ray diffraction and electron microscopy techniques, with the observed sequence of the 2D layers consistent with the targeted intergrowth. This ability to prepare targeted heterostructures is critical, since the number of possible configurations in the final compound increases rapidly as the number of constituents increases, from almost 60 000 with two constituents to over 130 million with three constituents and to over 35 billion with four constituents for 20 or fewer distinct layers in the unit cell. This general route for synthesizing specific multiple component heterostructures will accelerate the feedback loop in this growing research area, permitting theorists to assume specific structures in the search for enhanced properties and providing experimentalists with crystallographically aligned samples to test these predictions.

The method of modulated elemental reactants (MER) is used to prepare the layered compound Ti1+x Se2. Using a thin-film precursor prepared by sequentially depositing elemental titanium and selenium by physical vapor deposition, the binary compound is readily formed by short-duration annealing at 350°C. x-Ray diffraction indicates that TiSe2 layers in the film are highly oriented with the c-axis of the layers perpendicular to the substrate. Temperature-dependent electrical resistivity and Hall coefficient measurements for the MER-prepared specimen reveal temperature dependence that is distinct from crystalline stoichiometric TiSe2 in bulk form. The room-temperature Seebeck coefficient was measured to be −134 μV/K, which is opposite in sign and significantly larger in magnitude than stoichiometric crystalline TiSe2, suggesting that carrier transport in the disordered film is markedly different from the bulk crystalline material.

The synthesis and characterization of a new layered compound with the composition (PbSe)1·16TiSe2 in thin-film form is reported in this study. The structure of the new compound was characterized by specular and in-plane synchrotron x-ray diffraction studies, which indicate that the compound can be described as a layered intergrowth of PbSe and TiSe2 in which the individual constituents are precisely layered yet rotationally (turbostratically) disordered with an average in-plane domain size in the order of 10 nm. In contrast to crystalline (PbSe)1·16(TiSe2)2 prepared by solid-state reaction at high temperature, the electrical resistivity in the range 20–300 K is nearly temperature independent. The Seebeck coefficient at room temperature was measured to be S = −66(1) μV/K at the carrier concentration of n = 2·1(5) × 1021 cm−3, indicating behavior characteristic of a heavily doped semiconductor. The electrical transport properties for the (PbSe)1·16TiSe2 compound are compared and contrasted to those of other misfi t-layered and turbostratically disordered (MX)1+δ(TX2)n compounds.

Sir Harold Ridley is recognised today as the inventor of intraocular lens implantation, one the most successful and common procedures in all of surgery. His story, however, is not largely one of triumph and public accolade. This paper reviews Ridley's invention of the intraocular lens and highlights the struggles he faced after his discovery.

Purpose To determine the accuracy of postoperative predicted refractive outcomes in surgically aphakic pediatric patients undergoing secondary intraocular lens (IOL) implantation. Comparisons were also made with other variables historically considered important in cataract surgery. Methods Retrospective review of 50 eyes from 35 consecutive pediatric patients (≤18 years of age) undergoing secondary IOL implantation within the ciliary sulcus or posterior capsular bag. All cases were performed by 1 of 2 surgeons and all refractions were performed manually using the retinoscope by an experienced pediatric ophthalmologist. Results The mean patient age at the time of the secondary implantation was 6.5 years of age (range, 0.58-15.04). The mean patient age at the time of the primary cataract extraction was 0.78 years (range, 0.08-5.77). For all patients, mean absolute value of prediction error was 1.64 D (SD 1.58 D). There were no significant associations between mean absolute value of prediction error and any of the variables measured including axial length, corneal mean curvature, bag or sulcus implantation, formula used, or age at primary and secondary surgery (p > 0.05). Conclusions The mean absolute value of prediction error observed in this study is consistent with previous pediatric primary and secondary IOL data in that it shows a considerable difference from that expected in adult populations. Our findings support the argument that methods currently employed to calculate IOL power may fail to accurately account for all the variations in the eyes of pediatric patients.

Sir Harold Ridley is recognised today as the inventor of intraocular lens implantation, one the most successful and common procedures in all of surgery. His story, however, is not largely one of triumph and public accolade. This paper reviews Ridley's invention of the intraocular lens and highlights the struggles he faced after his discovery.

Introduction The purpose of this study was to determine whether the outcomes following placement of a fluocinolone acetonide implant (Retisert®; Bausch & Lomb, Inc.) combined with an Ahmed™ glaucoma valve (New World Medical, Inc.) in eyes with uveitic glaucoma (UG Retisert) were different when compared to an Ahmed valve alone in eyes with uveitic glaucoma or primary open angle glaucoma (UG non-Retisert and POAG, respectively). Methods Retrospective, interventional study of consecutive uveitic and OAG eyes undergoing Ahmed valve (AV) implantation with or without combined Retisert insertion at a single academic center between 2009 and 2012. Surgical success was defined as intraocular pressure (IOP) between 5 and 18 mmHg and greater than 20% reduction of IOP at two consecutive visits without need for additional IOP-lowering medications or surgical procedures. Secondary outcome measures included IOP and number of glaucoma medications. Results Sixty eyes of 60 patients (22 UG Retisert, 16 UG non-Retisert, 22 POAG) were included. Mean ± standard deviation surgical success duration was significantly greater in UG Retisert eyes, 629 ± 53 days, compared to those with UG non-Retisert, 361 ± 37 days, and POAG, 472 ± 65 days (P = 0.034). At 24 months, the mean IOP was 11.7, 12.1, and 15.0 mmHg and the average patient was on 1.45, 0.71, and 2.00 medications in the UG Retisert, UG non-Retisert, and POAG valve groups, respectively. Conclusion Retisert implants when combined with AV in uveitic glaucoma had a longer duration of surgical success than uveitic or POAG treated with AV insertion alone. Electronic supplementary material The online version of this article (doi:10.1007/s40123-015-0041-3) contains supplementary material, which is available to authorized users.

Thin films of the new title intergrowth compound consisting of a bilayer of SnSe and TiSe2 trilayer are prepared by self-assembly from a precursor containing modulated layers of Sn-Se and Ti-Se, which is synthesized by deposition of elemental layers (annealing at 350 °C).

Purpose To compare the surgical outcome visual acuity and complication rates among pediatric patients undergoing cataract surgery under local or general anesthesia in rural southern Ethiopia Methods This retrospective study included pediatric patients younger than years who underwent cataract surgery in rural southern Ethiopia during July August Local anesthesia was use in patients over the age of years unless they suffered from traumatic or bilateral cataract Clinical indices were collected before and following surgery including uncorrected visual acuity categorized into ambulatory better than hand motion and non ambulatory hand motion or light perception vision intraocular pressure cycloplegic refraction and ocular complications Results Ninety one eyes of consecutive patients male female were included in the study The average age at diagnosis was plusmn years Fifty five operations were performed under general anesthesia GA and using local anesthesia LA The percentage of patients with ambulatory UCVA improved significantly in both the GA vs p lt and LA groups vs lt No significant differences between the groups were noted regarding visual acuity results or complications Conclusions Our results suggest that the outcomes of pediatric cataract surgery performed under either local or general anesthesia were comparable LA should be considered a valid option for older children undergoing cataract surgery especially when medical resources are limited

PURPOSE The Parry-Romberg syndrome, or progressive hemifacial atrophy, is a slowly progressive marked facial deformity because of atrophy of subcutaneous fat and skin, cartilage, and bone wasting. Various ocular findings may be present in approximately 40% of cases of progressive hemifacial atrophy. We describe a novel case of a 42-year-old woman with progressive hemifacial atrophy and bilateral retinal dystrophy consistent with retinitis pigmentosa. METHODS Case report and literature review. RESULTS Clinical features, fundus photographs, visual fields, and electroretinographic findings are reported. CONCLUSION Progressive hemifacial atrophy can occur with retinitis pigmentosa.

Telluride misfit layer compounds are reported for the first time. These compounds were synthesized using a novel approach of structurally designing a precursor that would form the desired product upon low-temperature annealing, which allows the synthesis of kinetically stable products that do not appear on the equilibrium phase diagram. Four new compounds of the [(PbTe)1.17]m(TiTe2)n family are reported, and their structures were examined by a variety of X-ray diffraction techniques.

Importance Measurement of retinal nerve fiber layer (RNFL) thickness using optical coherence tomography can aid in the diagnosis and management of glaucoma. We observed a previously unreported phenomenon in eyes with uveitis-associated glaucoma in which paradoxical changes in RNFL thickness were noted. Observations Four eyes of 3 patients with uveitis-associated glaucoma had a relatively normal RNFL measurement on presentation during periods of active uveitis and raised intraocular pressure. Subsequent control of uveitis and intraocular pressure was associated with a paradoxical thinning of the RNFL and increased cupping. Conclusions and Relevance Normal-appearing measurements of RNFL thickness in patients with uveitis should be interpreted cautiously in those with a raised intraocular pressure. Physicians should recognize that continued thinning of the RNFL and increased cupping, despite good intraocular pressure control in such eyes, may be due to resolution of edema of the RNFL.

The title compound is prepared by annealing (350 °C, N2) a system of 28 repetitions of sputtered layer sequences of Ti-Se-Ti-Se-Pb-Se.

To assess the prevalence of eye disease among malnourished children in a rural Ethiopian health center and evaluate correlations between xerophthalmia and grades of malnutrition. A retrospective, cross-sectional survey. An institution-based cross-sectional prospective study was performed at Bushulo Health Center in rural south Ethiopia and included all children age 6 months to 14 years receiving care for malnourishment from June 1st to July 30th, 2008. Data collection involved a combination of interviews with caretakers, ocular examination by a pediatric ophthalmologist and anthropometric measurements. One hundred and seventy-three children (average age at examination 2.9 ± 0.2 years) were treated for malnutrition (97 female, 76 male). One hundred and forty-nine patients had moderate malnutrition (86.03 %) and 24 had severe malnutrition (13.9 %). The following eye diseases were diagnosed--trachoma (12.1 %), blepharitis (13.3 %) and xerophthalmia (20.8 %). Severely malnourished children were more likely to suffer from xerophthalmia than moderately malnourished children (p < 0.0001). When comparing anthropometric measurements to the diagnosis of xerophthalmia, only weight percentile showed significance (p = 0.008). Xerophthalmia is a common global cause of pediatric blindness and is highly correlated with severe malnutrition. Continued efforts are necessary to improve nutrition and outcomes in these patients.

Primary congenital glaucoma is the most common type of infantile glaucoma, yet it remains a relatively rare disease. Treatment is principally surgical, and management lasts a lifetime. In the developing world, delayed diagnosis, limited treatment, and inadequate follow-up lead to a heavier burden on the patient and community. We highlight the epidemiology and genetics of the disease, its current management and prognosis, and the limitations facing both providers and patients in the developing world. Further efforts are necessary to provide effective, timely screening of children and allocate adequate resources to allow health care workers to reduce the rate of avoidable blindness in developing countries.