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Category: Ankle; Trauma Introduction/Purpose: Over the last decade, much attention has been paid to the fractures of the posterior malleolus as it became obvious that the mere presence of a posterior tibial fragment is associated with a less favorable prognosis in malleolar fractures. It seems logical to pay the anterior restraints of the ankle joint a similar attention as to the posterior ones. The anteriolateral distal tibia may be considered a 'fourth' or anterior malleolus. Here, we present a technique of fixation of trimalleolar fractures with additional fracture of the anterior tibial tubercle ('quadrimalleolar') or anterior fibular rim ('quadrimalleolar equivalent'). Methods: Twenty-four patients with a mean age of 60 years were treated with open reduction and internal fixation of all 4 malleoli. There were 17 quadrimalleolar and 6 quadrimalleolar equivalent fractures. One patient had both anterior tibial and fibular avulsion fractures in addition to a trimalleolar ankle fracture. Surgical approaches and internal fixation were tailored individually. Twenty patients were operated in prone position with direct fixation of the posterior malleolus and 4 patients in supine position with indirect anterior to posterior screw fixation of the posterior malleolus under transfibular control of reduction. Results: After fixation of al 4 malleoli, only one patient (4%) required a syndesmotic screw for residual syndesmotic instability on intraoperative testing. There were no infections, and no wound healing problems. All patients went on to solid union. No late fusions were needed. Nineteen patients (79%) could be reevaluated after a mean of 77 months (range, 15 to 156 months) follow- up. The Foot Function Index averaged 15 (range, 50 to 0), the Olerud and Molander Score averaged 79 (range, 45 to 100) and the AOFAS Ankle and Hindfoot Scale averaged 87 (range, 39 to 100). Conclusion: Fixation of the anterior and posterior tibial fragments increases syndesmotic stability by providing a bone-to-bone fixation. Reduction of displaced anterior and posterior tibial rim fractures restores the physiological shape of the tibial incisura and therefore facilitates fibular reduction. In the majority of cases, this also restores articular congruity of the lateral tibial plafond. Anatomic reduction of the anterior and posterior malleolus in addition to medial and lateral malleolar fixation leads to favourable functional results despite a complex (quadrimalleolar) fracture pattern.

Conventional spectroscopic ellipsometry is a powerful tool in optical metrology. However, when it comes to the characterization of non-periodic nanostructures or structured fields that are much smaller than the illumination spot size, it is not well suited as it integrates the results over the whole illuminated area. Instead, imaging ellipsometry can be applied. Especially imaging Mueller matrix ellipsometry is highly useful in nanostructure characterization and defect inspection, as it is capable to measure the complete Mueller matrix for each pixel in a microscope image of the sample. It has been shown that these so-called Mueller matrix images can help to distinguish geometrical features of nanostructures in the sub-wavelength regime due to visible differences in off-diagonal matrix elements. To further investigate the sensitivity of imaging Mueller matrix ellipsometry for sub-wavelength sized features, we designed and fabricated a sample containing geometrical nanostructures with lateral dimensions ranging from 50 to 5,000 nm. The structures consist of square and circular shapes with varying sizes and corner rounding. For the characterization of their Mueller matrix images, we constructed an in-house Mueller matrix microscope capable of measuring the full Mueller matrix for each pixel of a CCD camera, using an imaging system and a dual-rotating compensator configuration for the ellipsometric system. The samples are illuminated at 455 nm wavelength and the measurements can be performed in both transmission and reflection. Using this setup, we systematically examine the sensitivity of Mueller matrix images to small features of the designed nanostructures. Within this contribution, the results are compared with traceable atomic force microscopy measurements and the suitability of this measurement technique in optical nanometrology is discussed. AFM measurements confirm that the fabricated samples closely match their design and are suitable for nanometrological test measurements. Mueller matrix images of the structures show close resemblance to numerical simulations and significant influence of sub-wavelength features to off-diagonal matrix elements.

Introduction: Childhood obesity is a principal concern worldwide. Guatemalan households have the highest prevalence of double burden of malnutrition in the world. These households are self-identified as indigenous and live with lower incomes in rural communities. However, there are limited data on risk factors for childhood obesity and limited information regarding the school environments, especially in rural communities. The objectives of this study were to determine the prevalence of overweight and obesity in a sample of rural schoolchildren, evaluate whether there is significant variability across schools, and characterize the food environment around public elementary schools in rural communities. Methods: A cross-sectional study was conducted in four rural public schools within three villages of El Progreso, a Department (state) of Guatemala, located about 60 km east of Guatemala City. Anthropometric measures and sociodemographic information for 398 schoolchildren and their mothers were collected in 2018. Environmental audits of food outlets and food advertisements were completed for a 250- and 500-meter radius around schools. Food outlets and food advertisements were categorized as healthy and less healthy, or acceptable or not acceptable, respectively, using international protocols. One-way ANOVA was used to compare schools and continuous demographic variables. Fisher’s LSD post hoc test was used to examine differences between schools. Chi-Squared tests were conducted to evaluate differences between categorical demographic variables, overweight and obesity, and variables regarding food environments. A logistic regression was used to examine factors associated with overweight and obesity and variability across schools, adjusted for household income, child sex and age, and maternal education and age. Results: The overall percentage of overweight and obesity among schoolchildren across all four schools was 32.4%. There was a higher percentage of less healthful food outlets compared to healthful food outlets and overall food outlets within

Interferometric experiments are often limited in sensitivity by the thermal noise of the mirrors. In particular, interferometric gravitational wave detectors and laser stabilization resonators can benefit from reduced mirror noise. We present results of experimental investigations on micro-structured mirrors (meta-mirrors) and hybrid etalon mirrors (meta-etalons) promising particularly low thermal noise. We show the first characterization of meta-etalons scattering and absorption losses, demonstrating optical losses below 500 ppm. This level of optical losses is sufficient for planning direct thermal noise measurement in dedicated optical cavity experiments. These measurements would be very important for validating the thermal noise predictions. We present our development toward the integration of meta-etalons in ultra-stable optical cavities.

In order to accomplish more functional and efficient light routing on a chip, photonic integration is necessary. Particularly in quantum technologies, which require a high precision of operation, avoiding bulky optical arrangements is in high demand. Scalable and robust photonic components open up a plethora of possibilities. The light guiding systems have to be able to cover a wide range of operational wavelengths and different light polarization states. In this work, we present the first numerical results for our approach of a PIC producing NIR circularly polarized light based on a Si3N4 material platform. This concept includes waveguides and metasurfaces that are easily integrable on the chip surface of many trapped-ion quantum computer architectures.

Metasurfaces, the two-dimensional variant of metamaterials, manipulate light in unique ways, opening up a whole new world of optical functionalities, ranging from optical imaging to quantum optics. High reflectivities and tailored phase profiles could allow such metamirrors to outperform conventional multilayer mirrors for high-precision optical interferometry due to their low thermal noise. Here, we design twin metamirrors with theoretical reflectivities of > 99.9 % at 1064 nm and 1550 nm. These mirrors can be implemented in bispectral low-noise optical cavities, which would reduce the number of cavities or can be used as a transfer cavity for quantum experiments like atomic clocks.

Abstract Background In this work, a nanostructured guided-mode resonance filter matrix with high transmission efficiency and narrow bandwidth is demonstrated. The developed nano-filter arrays have various usages, e.g., combined with the CMOS image sensors to realize compact spectrometers for biomedical sensing applications. Methods In order to optimize the filter performance, the spectral responses of filters with different structural parameters are carefully studied based on the variable-controlling method. A quality factor is carried out for quantitative characterization. Results In this case, a high fill factor of 0.9 can strongly suppress sidebands, while buffer layer thickness can be adjusted to mainly control the bandwidth. The transmission peaks shift from 386 nm to 1060 nm with good linearity when periods vary from 220 nm to 720 nm. The incident angle dependence is simulated to be ~ 1.1 nm/degree in ±30° range. The filters are then fabricated and characterized. The results obtained from both simulations and experiments agree well, where the filters with the period of 352 nm exhibit simulated and measured transmission peaks of 564 nm and 536 nm, the FWHM of 13 nm and 17 nm, respectively. In terms of metal material, besides aluminum, silver is also investigated towards optimization of the transmission efficiency. Conclusion The transmission spectra of designed filters have high transmission and low sideband; its peaks cover the whole visible and near infrared range. These characteristics allow them to have the possibility to be integrated into image sensors for spectrometer applications.

Objectives Few studies have used longitudinal data to study the development of cognition over the life course in low-income and middle-income countries. The objectives of this study were to assess predictors of cognitive development trajectories from 6 months through 7 years, and if these trajectories predicted adult cognitive function in a birth cohort from Guatemala.Design We analysed data from the INCAP Nutrition Supplementation Trial Longitudinal Study in Guatemala. Cognition was assessed at eight different time points between 6 months and 7 years. We derived childhood development trajectories using latent class growth analysis. We assessed predictors of the trajectories using ordinal logistic regression, and associations between childhood trajectories and adult non-verbal intelligence and literacy at age 18–52 years (mean±SD =42.7±6.4 years) using mixed models.Setting The study was conducted in four Guatemalan villages.Participants The study included 927 participants from Guatemala with repeated measurements of cognitive function during the first 7 years of life.Results We identified three trajectories of cognitive development (high: n=214, average: n=583, low: n=130). Participants whose mothers were taller (proportional log odds (PO)=0.03, 95% CI=0.01 to 0.06), had more years of schooling (PO=0.15, 95% CI=0.06 to 0.25), or lived in households with higher socioeconomic scores (PO=0.19, 95% CI=0.09 to 0.29) were more likely to follow higher trajectories. Childhood trajectories predicted adult non-verbal intelligence (high=18.4±0.3, average=14.6±0.53, low=11.4±0.9) and literacy (high=63.8±2.0, average=48.6±1.2, low=33.9± 2.6) scores.Conclusions In this sample from Guatemala, cognitive development trajectories from 6 months through 7 years were associated with adult non-verbal intelligence and literacy. These findings provide evidence of tracking of cognition over time in a transitioning low-income setting.

Objective In Guatemala, cirrhosis is among the 10 leading causes of death, and mortality rates have increased lately. The reasons for this heavy burden of disease are not clear as the prevalence of prominent risk factors, such as hepatitis B virus, hepatitis C virus and heavy alcohol consumption, appears to be low. Aflatoxin B1 (AFB1) exposure, however, appears to be high, and thus could be associated with the high burden of cirrhosis. Whether AFB1 increases the risk of cirrhosis in the absence of viral infection, however, is not clear.Design Cirrhosis cases (n=100) from two major referral hospitals in Guatemala City were compared with controls (n=200) from a cross-sectional study. Logistic regression was used to estimate the ORs and 95% CIs of cirrhosis and quintiles of AFB1 in crude and adjusted models. A sex-stratified analysis was also conducted.Results The median AFB1 level was significantly higher among the cases (11.4 pg/mg) than controls (5.11 pg/mg). In logistic regression analyses, higher levels of AFB1 was associated with cirrhosis (quintile 5 vs quintile 1, OR: 11.55; 95% CI 4.05 to 32.89). No attenuation was observed with adjustment by sex, ethnicity, hepatitis B virus status, and heavy alcohol consumption. A significantly increasing trend in association was observed in both models (p trend