Evaluation of the relationship between HbA1c level and retina choroidal thickness in patients with gestational diabetes mellitus / Avaliação da relação entre o nível de HbA1c e a espessura coroidal da retina em pacientes com diabetes mellitus gestacional

ABSTRACT Purpose: To investigate the effect of hemoglobin A1c level on central macular thickness and central, nasal, and temporal choroidal thickness in patients with gestational diabetes mellitus. Methods: This retrospective study included 41 patients who had been diagnosed with gestational diabetes mellitus and undergone a 75-g oral glucose tolerance test between 24 and 28 weeks of gestation. They were divided into two groups based on their hemoglobin A1c level (group 1: hemoglobin A1c <6.0% and group 2: hemoglobin A1c ≥6.0%). All patients underwent a complete ophthalmologic examination. The central macular thickness and central, nasal, and temporal choroidal thickness were measured using optical coherence tomography. Results: Of the 3,016 pregnant women screened, 7.5% (n=228) were diagnosed with gestational diabetes mellitus during the study period and 41 of these patients were included in the study. Group 1 comprised 48 eyes from 24 patients and Group 2 consisted of 34 eyes of 17 patients. The average body mass index values were 30.8 ± 3.3 and 35.1 ± 9.0, respectively (p=0.002). The insulin use rates were 29.2% and 76.5%, respectively (p=0.000). Mean central macular thickness values were 250.8 ± 14.3 µm and 260.9 ± 18.1 µm, respectively, and the difference was significant (p=0.008). Conclusions: Although the body mass index and central macular thickness values were significantly higher in Group 2, there was no difference in the central, nasal, and temporal choroidal thickness between the two groups.

RESUMO Objetivos: Investigar o efeito do nível de hemoglobina A1c (HbA1c) na espessura macular central e na espessura da coróide central, nasal e temporal em pacientes com diabetes mellitus gestacional. Métodos: Este estudo retrospectivo incluiu 82 olhos de 41 pacientes diagnosticadas com diabetes mellitus gestacional, as quais fizeram um teste de tolerância oral à glicose de 75 g entre 24 e 28 semanas de gestação. As pacientes foram divididas em dois grupos de acordo com o nível de hemoglobina A1c (hemoglobina A1c <6,0% e hemoglobina A1c ≥6,0%). Todas as pacientes foram submetidas a exame oftalmológico completo e, a espessura macular central, a espessura central, nasal e temporal da coroide foram mensuradas por tomografia de coerência óptica. Resultados: Durante o período do estudo, das 3.016 gestantes triadas, 7,5% (n=228) foram diagnosticadas com diabetes mellitus gestacional. Destas, 41 pacientes foram analisadas de acordo com os critérios do estudo. Houve 48 olhos de 24 pacientes no primeiro grupo com hemoglobina A1c <6,0% e 34 olhos de 17 pacientes no segundo grupo com hemoglobina A1c ≥6,0%. Os valores médios do índice de massa corporal foram de 30,8 ± 3,3 e 35,1 ± 9,0, respectivamente (p=0,002). As taxas referentes ao uso de insulina foram de 29,2% e 76,5%, respectivamente (p=0,000). Os valores médios da espessura macular central foram medidos em 250,8 ± 14,3 µm e 260,9 ± 18,1 µm, respectivamente e a diferença foi significativa entre os dois grupos (p=0,008). Conclusões: Embora os valores do índice de massa corporal e da espessura macular central tenham sido significativamente maiores no Grupo 2 com hemoglobina A1c alta, não houve diferenças nas medidas de espessura coroidal central, nasal e temporal entre os dois grupos.

Bottom-Up Nanofabrication with Extreme-Ultraviolet Light: Metal-Organic Frameworks on Patterned Monolayers.

The fabrication of integrated circuits with ever smaller (sub-10 nm) features poses fundamental challenges in chemistry and materials science. As smaller nanostructures are fabricated, thinner layers of materials are required, and surfaces and interfaces gain a more important role in the formation of nanopatterns. We present a new bottom-up approach in which we use the high optical resolution offered by extreme ultraviolet (EUV) lithography to print patterns on self-assembled monolayers (SAMs). Upon radiation, low-energy electrons induce chemical changes in the SAM so that the projected image is transferred to the substrate surface. We use the chemical differences between exposed and unexposed regions to promote a selective growth of hybrid structures that can act as an etch-resistant layer for further pattern transfer or can be used as functional nanostructures. The EUV doses required to promote selective growth on exposed areas are close to industrial requirements. Furthermore, this method allows for the independent tuning of different steps in the EUV lithography process (photo-induced chemistry, spatially resolved chemical contrast, and formation of nanopatterns), an advantage over current resists, in which the same material plays all roles.

The role of electrophysiological examination in the diagnosis of carpal tunnel syndrome: Analysis of 2516 patients.

OBJECTIVE: The aim of the present study was to assess the correlation between patient history, physical examination, and electrophysiological method of assessment in patients with clinical suspicion of carpal tunnel syndrome (CTS). PATIENTS AND METHODS: Results of electrophysiological examinations performed from 2009 to 2016 on 3151 hands of 2516 patients who had symptoms that clinically suggested CTS were examined retrospectively. Patients were assessed in terms of age, gender, direction of nerve compression, and presence and degree of CTS as determined electrophysiologically. Kolmogorov-Smirnov test, Levene's test, and Chi-square test were used for statistical analyses. Level of significance was accepted as P < 0.05. RESULTS: : Of the 2516 patients, 1838 (73.1%) were female and 678 (26.9%) were male. Average age was 48.60 ± 14.83 years, and 1858 (73.8%) of the patients had complaints in only 1 hand, whereas 658 (26.2%) had complaints in bilateral hands. CTS was detected in 1383 patients (54.9%; female/male: 1019/364) and average age was 52.16 ± 13.84 years. No statistically significant association was found between CTS and gender. Nerve compression was found in 1 hand of 71.5% (1328) of females and 28.5% (530) of males, and this result was found to be statistically significant. No significant association was found between degree and direction of nerve compression. CONCLUSION: Only 54.9% of the patients with clinical suspicion were found to have CTS. Given complexity of the hand and a large number of potential pathologies, electrophysiological examination is necessary for definitive diagnosis to avoid unnecessary surgical interventions.

Single-digit-resolution nanopatterning with extreme ultraviolet light for the 2.5 nm technology node and beyond.

All nanofabrication methods come with an intrinsic resolution limit, set by their governing physical principles and instrumentation. In the case of extreme ultraviolet (EUV) lithography at 13.5 nm wavelength, this limit is set by light diffraction and is ≈3.5 nm. In the semiconductor industry, the feasibility of reaching this limit is not only a key factor for the current developments in lithography technologies, but also is an important factor in deciding whether photon-based lithography will be used for future high-volume manufacturing. Using EUV-interference lithography we show patterning with 7 nm resolution in making dense periodic line-space structures with 14 nm periodicity. Achieving such a cutting-edge resolution has been possible by integrating a high-quality synchrotron beam, precise nanofabrication of masks, very stable exposures instrumentation, and utilizing effective photoresists. We have carried out exposure on silicon- and hafnium-based photoresists and we demonstrated the extraordinary capability of the latter resist to be used as a hard mask for pattern transfer into Si. Our results confirm the capability of EUV lithography in the reproducible fabrication of dense patterns with single-digit resolution. Moreover, it shows the capability of interference lithography, using transmission gratings, in evaluating the resolution limits of photoresists.

Nearly amorphous Mo-N gratings for ultimate resolution in extreme ultraviolet interference lithography.

We present fabrication and characterization of high-resolution and nearly amorphous Mo1 - xNx transmission gratings and their use as masks for extreme ultraviolet (EUV) interference lithography. During sputter deposition of Mo, nitrogen is incorporated into the film by addition of N2 to the Ar sputter gas, leading to suppression of Mo grain growth and resulting in smooth and homogeneous thin films with a negligible grain size. The obtained Mo0.8N0.2 thin films, as determined by x-ray photoelectron spectroscopy, are characterized to be nearly amorphous using x-ray diffraction. We demonstrate a greatly reduced Mo0.8N0.2 grating line edge roughness compared with pure Mo grating structures after e-beam lithography and plasma dry etching. The amorphous Mo0.8N0.2 thin films retain, to a large extent, the benefits of Mo as a phase grating material for EUV wavelengths, providing great advantages for fabrication of highly efficient diffraction gratings with extremely low roughness. Using these grating masks, well-resolved dense lines down to 8 nm half-pitch are fabricated with EUV interference lithography.

Nonlinear superchiral meta-surfaces: tuning chirality and disentangling non-reciprocity at the nanoscale.

Circularly polarized light is incident on a nanostructured chiral meta-surface. In the nanostructured unit cells whose chirality matches that of light, superchiral light is forming and strong optical second harmonic generation can be observed.

Rendering dark modes bright by using asymmetric split ring resonators.

We have studied both theoretically and experimentally symmetric and asymmetric planar metallic Split Ring Resonators. We demonstrate that introducing structural asymmetry makes it possible to excite several higher order modes of both even (l = 2) and odd (l = 3, 5) order, which are otherwise inaccessible for a normally incident plane wave in symmetric structures. Experimentally we observe that the even mode resonances of asymmetric resonators have a quality factor 5.8 times higher than the higher order odd resonances.

Fabrication of high-resolution large-area patterns using EUV interference lithography in a scan-exposure mode.

Limited beam spot size is a major limitation of interference lithography. This limits the area of patterning and reduces the pattern homogeneity. We describe a scanning exposure technique to circumvent this problem. We show the generation of uniform and seamless gratings with half-pitches down to 35 nm over an area of several mm(2) using EUV interference lithography. The presented technique offers a fast and cost-effective method of fabricating one- and two-dimensional periodic nanostructures with improved uniformity and increased patterning area.

Fabrication of quasiperiodic nanostructures with EUV interference lithography.

We demonstrate the fabrication and analysis of well-ordered high-resolution quasiperiodic nanostructures with feature sizes down to a few tens of nanometers using extreme ultraviolet interference lithography. A well-controlled mask manufacturing process for producing high quality transmission diffraction masks enables simple and fast fabrication of highly ordered 2D quasiperiodic structures using 5- and 8-beam interference setups.

Electric and magnetic resonances in arrays of coupled gold nanoparticle in-tandem pairs.

We present an experimental and theoretical study on the optical properties of arrays of gold nanoparticle in-tandem pairs (nanosandwiches). The well-ordered Au pairs with diameters down to 35 nm and separation distances down to 10 nm were fabricated using extreme ultraviolet (EUV) interference lithography. The strong near-field coupling of the nanoparticles leads to electric and magnetic resonances, which can be well reproduced by Finite-Difference Time-Domain (FDTD) calculations. The influence of the structural parameters, such as nanoparticle diameter and separation distance, on the hybridized modes is investigated. The energy and lifetimes of these modes are studied, providing valuable physical insight for the design of novel plasmonic structures and metamaterials.

A mass and time-of-flight spectroscopy study of the formation of clusters in free-jet expansions of normal D2.

The mass spectra in the range of 2(D+)-38(D19+) amu of clusters formed in a supersonic free-jet expansion of normal D2 are investigated as functions of source temperature in the range of 95-220 K and of source pressure in the range of 10-120 bars. For some of the small ion fragments, time-of-flight distributions are also measured. For large clusters (n > 200) the intensities of the odd-numbered ion fragments exhibit magic numbers at D9+ and D15+ in accordance with previous experiments and calculations. The even-numbered ion fragments have much smaller intensities and exhibit new magic numbers at D10+ and D14+. For source conditions such that large clusters are formed, the intensities of the various different ion fragments are observed to saturate beyond a certain source pressure. At lower source pressures, where only small clusters are formed, the terminal mole fractions of the neutral dimers are analyzed in the light of available theories which take into account both the thermodynamics and the kinetics of the expansion. At higher source pressures and lower temperatures, where larger clusters are formed, the sizes of the neutral clusters are estimated using scaling laws and are found to be consistent with the mass spectra and measured time-of-flight distributions. By using a variety of techniques it has been possible to obtain reliable conclusions about the neutral cluster sizes for the present free-jet expansion conditions.