Characterization of extended defects in 2D materials using aperture-based dark-field STEM in SEM.

Quantitative diffraction contrast analysis with defined diffraction vectors is a well-established method in TEM for studying defects in crystalline materials. A comparable transmission technique is however not available in the more widely used SEM platforms. In this work, we transfer the aperture-based dark-field imaging method from the TEM to the SEM, thus enabling quantitative diffraction contrast studies at lower voltages in SEM. This is achieved in STEM mode by inserting a custom-made aperture between the sample and the STEM detector and centering the hole on a desired reflection. To select individual reflections for dark-field imaging, we use our Low Energy Nanodiffraction (LEND) setup [Schweizer et al., Ultramicroscopy 213, 112956 (2020)], which captures transmission diffraction patterns from a fluorescent screen positioned below the sample. The aperture-based dark-field STEM method is particularly useful for studying extended defects in 2D materials, where (i) stronger diffraction at the lower voltages used in SEM is advantageous, but (ii) two-beam conditions cannot be established, making quantitative diffraction contrast analysis with standard bright-field and annular dark-field detectors impossible. We demonstrate the method by studying basal plane dislocations in bilayer graphene, which have attracted considerable research interest due to their exceptional structural and electronic properties. Direct comparison of results obtained on identical dislocations by the established TEM method and by the new aperture-based dark-field STEM method in SEM shows that a reliable Burgers vector analysis is possible by applying the well-known g·b=0 invisibility criterion. We further use the LEND setup to acquire 4D-STEM data and show that the virtual dark-field images match well with those in aperture-based dark-field STEM images for reliable Burgers vector analysis.

Bioelectrical Impedance Vectors Analysis of Sarcopenic Older Adults Submitted to a Resistance Training Program.

The objective of the present study is to analyze the changes in bioimpedance vector analysis (BIVA) and phase angle (PhA) in sarcopenic older people submitted to a 12-week resistance training (RT) program according to classic and specific analyses. To this end, 20 sarcopenic older adults of both sexes, invited through media, underwent bioimpedance analysis before and after the RT carried out three times a week, for 12 weeks. The mean impedance vectors of the groups established for the confidence ellipses (95% of the confidence ellipse) are compared using Hotelling's T2 test. The distance D from Mahalanobis is also calculated. Classic and Specific BIVA are presented. The resistance values for the classical analyses (R/H) decreased across all groups (whole group, women and men, p < 0.05), with approximate decreases ranging from 9.4% to 10%, while the classic reactance (Xc/H) decreased (p < 0.05) only for the whole group (5.9%) and men (7.7%). For the specific BIVA, trends are verified for the whole sample, with a decrease in resistance (R.sp) and an increase in reactance (Xc.sp). In conclusion, the RT program in sarcopenic individuals promoted a reduction in resistance values in classical analyses, indicating a possible increase in hydration status and, consequently, musculoskeletal mass.

Independent Vector Analysis for Feature Extraction in Motor Imagery Classification.

Independent vector analysis (IVA) can be viewed as an extension of independent component analysis (ICA) to multiple datasets. It exploits the statistical dependency between different datasets through mutual information. In the context of motor imagery classification based on electroencephalogram (EEG) signals for the brain-computer interface (BCI), several methods have been proposed to extract features efficiently, mainly based on common spatial patterns, filter banks, and deep learning. However, most methods use only one dataset at a time, which may not be sufficient for dealing with a multi-source retrieving problem in certain scenarios. From this perspective, this paper proposes an original approach for feature extraction through multiple datasets based on IVA to improve the classification of EEG-based motor imagery movements. The IVA components were used as features to classify imagined movements using consolidated classifiers (support vector machines and K-nearest neighbors) and deep classifiers (EEGNet and EEGInception). The results show an interesting performance concerning the clustering of MI-based BCI patients, and the proposed method reached an average accuracy of 86.7%.

Variations in bioelectrical impedance devices impact raw measures comparisons and subsequent prediction of body composition using recommended estimation equations.

BACKGROUND & AIMS: Bioelectrical impedance analysis (BIA) for body composition estimation is increasingly used in clinical and field settings to guide nutrition and training programs. Due to variations among BIA devices and the proprietary prediction equations used, studies have recommended the use of raw measures of resistance (R) and reactance (Xc) within population-specific equations to predict body composition. OBJECTIVE: We compared raw measures from three BIA devices to assess inter-device variation and the impact of differences on body composition estimations. METHODS: Raw R, Xc, impedance (Z) parameters were measured on a calibrated phantom and athletes using tetrapolar supine (BIASUP4), octapolar supine (BIASUP8), and octapolar standing (BIASTA8) devices. Measures of R and Xc were compared across devices and graphed using BIA vector analysis (BIVA) and raw parameters were entered into recommended athlete-specific equations for predicting fat-free mass (FFM) and appendicular lean soft tissue (ALST). Whole-body FFM and regional ALST were compared across devices and to a criterion five-compartment (5C) model and dual energy X-ray absorptiometry for ALST. RESULTS: Data from 73 (23.2 ± 4.8 y) athletes were included in the analyses. Technical differences were observed between Z (range 12.2-50.1Ω) measures on the calibrated phantom. Differences in whole-body impedance were apparent due to posture (technological) and electrode placement (biological) factors. This resulted in raw measures for all three devices showing greater dehydration on BIVA compared to published norms for athletes using a separate BIA device. Compared to the 5C FFM, significant differences (p < 0.05) were observed on all three equations for BIASUP8 and BIASTA8, with constant error (CE) from -2.7 to -4.6 kg; no difference was observed for BIASUP4 or when device-specific algorithms were used. Published equations resulted in differences as large as 8.8 kg FFM among BIA devices. For ALST, even after a correction in the error of the published empirical equation, all three devices showed significant (p < 0.01) CE from -1.6 to -2.9 kg. CONCLUSIONS: Raw bioimpedance measurements differ among devices due to technical, technological, and biological factors, limiting interchangeability of data across BIA systems. Professionals should be aware of these factors when purchasing systems, comparing data to published reference ranges, or when applying published empirical body composition prediction equations.

Jerk (d(acceleration)/dt) as an operative variable in pneumatic tube transport (PTT).

BACKGROUND: Jerk, the rate of change of acceleration (d(acceleration)/dt), is a known operative variable in public transportation safety, but this term has never appeared in the literature regarding pneumatic tube transport (PTT) and specimen integrity. We investigated profiles of acceleration and jerk for 2 PTT routes within our hospital system. METHODS: Acceleration data were collected for PTT for 2 routes (A, B) using an accelerometer. Acceleration vectors (a) were analyzed in terms of distributions of jerk (da/dt), and distributions of θ, the angle between successive acceleration vectors. RESULTS: Routes A and B had transit times of approximately 300 s. Acceleration vectors (a) ranged in magnitude from 0 to 8 g. For B, a > 1.2 g comprised 29.0% of results, compared to 13.5% of results for A (ratio = 2.1). Jerk ranged from 0 to 94 g/s. For B, jerk > 0.5 g/s comprised 71.9% of results, compared to 32.5% of results for A (ratio = 2.2). θ ranged from 0 to 180 degrees. For B, θ > 5 degrees comprised 59.3% of results, compared to 26.6% of results for A (ratio = 2.2). CONCLUSION: Differences in distribution in acceleration, jerk, and θ ran in parallel as variables for comparison between 2 PTT routes. Jerk and θ are likely to be operative variables in effects of PTT.

Carbon and Nutrient Limitations of Microbial Metabolism in Xingkai Lake, China: Abiotic and Biotic Drivers.

Microbial communities are crucial for water quality and biogeochemical cycling in freshwaters. Microbes secrete extracellular enzymes to decompose organic matter for their needs of nutrients and scarce elements. Yet, there is a lack of knowledge on microbial metabolic limitations in freshwaters, especially in lake sediments. Here, we examined the carbon, nitrogen, and phosphorus-acquiring extracellular enzyme activities and the bacterial and fungal communities of 30 sediments across Xingkai Lake, the largest freshwater lake in Northeast Asia. We further analyzed the microbial metabolic limitations via extracellular enzyme stoichiometry and explored the direct and indirect effects of abiotic and biotic factors on the limitations. We found that microbial metabolisms were primarily limited by phosphorus in Xingkai Lake. For instance, microbial carbon and phosphorus limitations were closely correlated to abiotic factors like water depth, total dissolved solids, sediment total carbon, and conductivity. The metabolic limitations were also affected by biotic factors, such as showing positive relationships with the alpha and beta diversity of bacteria, and with the beta diversity of fungi. In addition, community compositions of bacteria and fungi were mainly correlated to abiotic factors such as total carbon and dissolved organic carbon, respectively. Collectively, microbial metabolic limitations were affected directly or indirectly by abiotic factors and microbial communities. Our findings indicate that microbial metabolic limitations are not only driven by bacteria and fungi but also by abiotic factors such as water depth and total nitrogen, and thus provide empirical evidence for effective management of freshwater lakes under climate warming and intensified human activities.

The Homburg-Adelaide toric IOL nomogram: How to predict corneal power vectors from preoperative IOLMaster 700 keratometry and total corneal power in toric IOL implantation.

PURPOSE: The purpose of this study is to compare the reconstructed corneal power (RCP) by working backwards from the post-implantation spectacle refraction and toric intraocular lens power and to develop the models for mapping preoperative keratometry and total corneal power to RCP. METHODS: Retrospective single-centre study involving 442 eyes treated with a monofocal and trifocal toric IOL (Zeiss TORBI and LISA). Keratometry and total corneal power were measured preoperatively and postoperatively using IOLMaster 700. Feedforward neural network and multilinear regression models were derived to map keratometry and total corneal power vector components (equivalent power EQ and astigmatism components C0 and C45) to the respective RCP components. RESULTS: Mean preoperative/postoperative C0 for keratometry and total corneal power was -0.14/-0.08 dioptres and -0.30/-0.24 dioptres. All mean C45 components ranged between -0.11 and -0.20 dioptres. With crossvalidation, the neural network and regression models showed comparable results on the test data with a mean squared prediction error of 0.20/0.18 and 0.22/0.22 dioptres2 and on the training data the neural network models outperformed the regression models with 0.11/0.12 and 0.22/0.22 dioptres2 for predicting RCP from preoperative keratometry/total corneal power. CONCLUSIONS: Based on our dataset, both the feedforward neural network and multilinear regression models showed good precision in predicting the power vector components of RCP from preoperative keratometry or total corneal power. With a similar performance in crossvalidation and a simple implementation in consumer software, we recommend implementation of regression models in clinical practice.

Assessing the Role of Bioelectrical Impedance Vector Analysis in Prognosis and Prevention of Contrast-Associated Acute Kidney Injury After Percutaneous Coronary Intervention.

This study evaluated the impact of Bioelectrical Impedance Vector Analysis (BIVA)-guided hydration therapy on contrast-associated acute kidney injury (CA-AKI) in patients undergoing percutaneous coronary intervention (PCI). From April 2022 to January 2023, this prospective study at the Eastern General Hospital of the Chinese People's Liberation Army involved 902 adults with stable coronary artery disease (CAD) scheduled for PCI. BIVA measurements were performed pre-contrast, followed by a standard hydration regimen. The study focused on the development of CA-AKI and major adverse cardiovascular events (MACE, including all-cause death, nonfatal myocardial infarction, and target vessel revascularization) within 1 year post-PCI. Among the 902 patients (average age: 60.8 years, 65.2% men), CA-AKI post-PCI was observed in 10.8%. Those with CA-AKI had more comorbidities and higher baseline creatinine levels. The contrast volume-to-estimated Glomerular Filtration Rate (eGFR) ratio was higher in CA-AKI patients, with a significantly increased resistance/height ratio (R/H). High R/H values correlated with a greater risk of MACE and all-cause mortality within a year. The study underscores the importance of BIVA-guided hydration therapy and R/H ratio in predicting CA-AKI in PCI patients with stable CAD. Incorporating R/H ratio assessments may enhance pre-procedural risk assessment and improve long-term outcomes (P = .0017).

Seabuckthorn (Hippophae rhamnoides L.) plantation degradation aggravates microbial metabolic C and P limitations on the Northern Loess Plateau in China.

Vegetation degradation in arid and semi-arid regions reduces plant C inputs to the soil, which can impede soil nutrient cycling because of the limited C source for microbial metabolism. However, whether vegetation degradation aggravates microbial nutrient limitation in degraded ecosystems in arid and semi-arid regions is not fully understood. Here, we investigated changes in soil enzyme activity and microbial nutrient limitation along a well-documented gradient of degraded seabuckthorn (Hippophae rhamnoides L.) (slightly degraded, canopy dieback <25 %, moderately degraded, canopy dieback 25 %-75 %, and severely degraded, canopy dieback >75 %) in Liang (long ridge) and gully channel locations in the Pisha Sandstone region of the Loess Plateau, China. We found that as the magnitude of seabuckthorn degradation increased, activities of C-acquiring enzymes and ratios of C:N and C:P enzymes (0.54-0.80 and 0.52-0.77, respectively) increased whereas the N:P enzyme ratio (0.93-0.99) decreased. Stoichiometric modelling further indicated that microorganisms were limited by soil C and P (vector angle >45°) in the seabuckthorn plantation region, and the degradation of seabuckthorn plantation aggravated microbial C and P limitations. Partial least squares path modelling revealed that seabuckthorn degradation (canopy dieback) was the main factor explaining microbial C limitation variations, while soil physicochemical properties (pH and soil moisture content) and understory plant parameters (litter biomass) were the major factors underlying microbial P limitation of long ridge and gully channel formations, respectively. Our findings highlight synergistic changes between aboveground and belowground processes, suggesting an unexpected negative effect of vegetation degradation on soil microbial community and nutrient cycling. These insights offer a direction for the development of plantation nutrients management strategies in semi-arid and arid areas.

Proposal and validation of an equation to identify sarcopenia using bioelectrical impedance analysis-derived parameters.

OBJECTIVE: This study aimed to develop a simpler approach for diagnosing sarcopenia by using only bioelectrical impedance vector analysis parameters. METHODS: The study design was a cross-sectional study. The research was conducted based on the Itabashi Longitudinal Study on Aging, a community-based cohort study, with data collected from the 2022 and 2023 surveys in Itabashi Ward, Tokyo, Japan. The development cohort consisted of 1146 participants from the 2022 survey, and the validation cohort included 656 participants from the 2023 survey. Both cohorts were comprised of community-dwelling older adults with similar inclusion criteria. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. The logistic model utilized height divided by impedance at 50 kHz and phase angle to establish a new regression equation to identify sarcopenia. Regression equations were generated for the development cohort and validated for the validation cohort. Discriminatory ability was assessed using the area under the receiver operating characteristic curve (AUC) for men and women. RESULTS: The prevalence of sarcopenia was 20.7% and 14.8% in the development and validation cohort, respectively. The AUC (95% confidence interval) of the logistic model in discriminating sarcopenia was 0.92 (0.88, 0.95) for men and 0.82 (0.78, 0.86) for women in the development cohort and 0.85 (0.78, 0.91) for men and 0.90 (0.86, 0.95) for women in the validation cohort. CONCLUSION: The study demonstrated that a simple formula using bioelectrical parameters at 50 kHz proved useful in identifying sarcopenia in the older adult population.

Corrigendum: Influence of body composition assessment with bioelectrical impedance vector analysis in cancer patients undergoing surgery.

[This corrects the article DOI: 10.3389/fonc.2023.1132972.].

Specific bioelectrical vectors pattern in individuals with sarcopenic obesity.

BACKGROUND: Sarcopenic obesity is a common condition in the elderly associated with excessive adiposity and low muscle mass and strength. AIMS: This study aims to establish a method for detecting bioelectrical characteristics in individuals with sarcopenic obesity through specific Bioelectrical Impedance Vector Analysis (specific BIVA), while considering the characteristics of individuals with healthy, sarcopenic, and obese conditions. METHODS: The sample was composed by 915 Italian adults over 50 years of age (men: 74.6 ± 8.8 y; women:76.3 ± 8.8 y) living in Sardinia (Italy). A dataset of 1590 US adults aged 21 - 49 years retrieved from the 2003 - 2004 National Health and Nutrition Examination Survey was also considered in a final step of the study. Anthropometric (stature, weight, waist, arm, and calf circumferences) and whole-body bioelectrical variables were taken. In the Italian sample, bioelectrical impedance was applied to estimate the relative content of fat mass and skeletal muscle mass. Groups with healthy body composition (NS-NO), or consistent with sarcopenia (S), sarcopenic obesity (S-O), and obesity (O) were defined based on the cut-offs suggested by European expert guidelines (EWGSOP2 and ESPEN-EASO). Specific BIVA was applied to compare groups and to identify the area for sarcopenic obesity within young-adults tolerance ellipses. The position of the specific vector of US individuals with S-O, selected on the basis of DXA measurements, was also considered. RESULTS: In both sexes of the Italian sample, the bioelectrical characteristics of the four groups were different (p < 0.001). The differences were mainly related to vector length, indicative of higher fat mass, which was longer in the O and S-O groups, and phase angle, a proxy of intracellular/extracellular water and muscle mass, lower in the sarcopenic groups. Bioelectrical vectors of the S-O group fell in the right quadrant, outside of the 95 % tolerance ellipses of young adults. The mean vector of the US sample with S-O fell in the same area. Within the S-O area, women had similar bioelectrical values, while men showed phase angle variability, which was related to the severity of the condition. CONCLUSIONS: Specific BIVA detects body composition peculiarities of individuals with sarcopenic obesity, thus allowing their diagnosis when associated with low handgrip strength values.

The severity of early fluid overload assessed by bioelectrical vector impedance as an independent risk factor for longer patient care after cardiac surgery.

BACKGROUND AND AIMS: Fluid overload is a common postoperative complication in patients undergoing cardiac surgery. Although this condition is notably associated with relevant adverse outcomes, assessment of hydration status in clinical practice is challenging. Bioelectrical impedance vector analysis (BIVA) has emerged as a potentially effective method to monitor hydration changes, but the available evidence in critically ill patients undergoing cardiac surgery is limited and sometimes conflicting. The aim of this study was to explore by mean of BIVA the evolution over time of hydration status and its impact on relevant outcomes. METHODS: Prospective observational study enrolling 130 patients undergoing cardiac surgery. Height normalized impedance was calculated both before surgery (baseline) and in the first five postoperative days. Relevant clinical and laboratory data were collected daily close to BIVA measurements. Length of mechanical ventilation (MV), intensive care unit (ICU) and hospital stay exceeding the 75th percentile of the study population were considered as study endpoints. RESULTS: Compared to baseline, a significant reduction in impedance was found at first postoperative day, demonstrating a relevant fluid overload. An adjusted impedance at first postoperative day shorter than the best respective threshold was associated to longer MV (7.4 times), ICU stay (4.7 times) and hospital stay (5.6 times). A significant change in impedance and phase angle was documented throughout the observation days (p < 0.001), without returning to the baseline value. The co-existence of low impedance and high plasma osmolarity increased significantly the risk of incurring the study outcomes. CONCLUSIONS: In patients with cardiac surgery-induced fluid overload, recovery to baseline conditions occurs slowly. A relevant early fluid overload should be considered predictive for longer time of MV, ICU and total hospital stay.

Vector analysis outcomes after Femtosecond Laser In-Situ Keratomileusis (FS-LASIK) versus Small Incision Lenticule Extraction (SMILE) for moderate myopic astigmatism

Objectives@#To compare the vector analysis, visual, and refractive outcomes of femtosecond-assisted laser insitu keratomileusis (LASIK) and small incision lenticule extraction (SMILE) among myopic patients with moderate myopic astigmatism.@*Methods@#This was a single-center, retrospective, cohort study that compared eyes that underwent femtosecond LASIK or SMILE for the correction of myopia and astigmatism of 0.75 to 3.0 diopters. Vector analysis and standard graphs for reporting visual and refractive outcomes were utilized for analysis.@*Results@#There were 82 femtosecond LASIK-treated eyes and 80 SMILE-treated eyes with similar preoperative characteristics except for slightly higher mean preoperative sphere refraction in the SMILE group (-4.2±2.4 D vs -4.9±1.6 D, p=0.03). At 3 months, femtosecond LASIK group had better mean uncorrected distance visual acuity (UDVA) (LogMAR 0.006±0.06 vs 0.06±0.09, p=0.00) and had more eyes achieving postoperative UDVA of 20/20 or better (88% versus 56%). Although there were similar postoperative spherical equivalents, residual astigmatism was higher in the SMILE group (0.11±0.22 D vs 0.32±0.30 D, p=0.00). Vector analyses showed significantly better outcomes for femtosecond LASIK than for SMILE in terms of difference vector (DV), index of success (IOS), torque, and flattening index (FI). A trend for undercorrection for higher astigmatism was seen in both groups that was greater in the SMILE group. Both groups showed high safety with the majority of eyes showing postoperative corrected distance VA (CDVA) within 1 line of preoperative CDVA (98.8% versus 91.2%). @*Conclusion@#Although femtosecond LASIK and SMILE have similar predictability at 3 months, femtosecond LASIK has relatively better efficacy and superior astigmatic outcomes than SMILE for the correction of moderate myopic astigmatism.

Clinical effect of cross positioning method for correcting low and moderate astigmatism during small incision lenticule extraction / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate the clinical outcomes of using the cross-positioning method for correcting low and moderate astigmatism during small incision lenticule extraction(SMILE)surgery with Alpins vector analysis.METHODS: A total of 50 patients(81 eyes)with low and moderate astigmatism with the rule ≤1.50 D who underwent SMILE surgery at the laser myopia treatment center of Xi'an No.1 Hospital from May 2022 to November 2022 were included in the prospective randomized controlled study, and they were divided into two groups according to the random table, with 25 case(41 eyes)in cross-positioning group and 25 cases(40 eyes)in control group. In the cross-positioning group, the patients' head position was adjusted based on the cross intersection lines before the standard SMILE procedure, aligning the lateral canthi with the horizontal line and the midpoint of the eyebrows and the nose bridge with the vertical line. Postoperative visual acuity and refractive results at 3 mo were observed in both groups, and astigmatic changes were analyzed and evaluated using the Alpins vector analysis method.RESULTS: During the follow-up period, 6 cases(11 eyes)in the cross-positioning group were lost to follow-up, while in the control group, 8 cases(14 eyes)were lost to follow-up, with 19 cases(30 eyes)and 17 cases(26 eyes)finally included in the cross-positioning group and the control group, respectively. At 3 mo postoperatively, the uncorrected visual acuity(UCVA)of both groups' operated eyes was ≥1.0, and no serious complications occurred, with no significant differences in UCVA, best corrected visual acuity(BCVA), spherical power, and spherical equivalent between the cross-positioning group and the control group(all P&#x0026;#x003E;0.05). The cylindrical power in the cross-positioning group was 0.00(0.00, 0.00)D, which was lower than -0.13(-0.50, 0.00)D in the control group(P=0.01). The vector analysis results showed that the difference vector(DV)in the cross-positioning group was lower than that in the control group [0.00(0.00, 0.00)vs 0.13(0.00, 0.50), P=0.01], and the index of success(IOS)was better than that of the control group [0.00(0.00, 0.00)vs 0.18(0.00, 0.77), P&#x0026;#x003C;0.01]. At 3 mo postoperatively, 26(87%)and 15(58%)eyes in the cross-positioning group and control groups achieved an angle of error(AE)within ±5°, respectively.CONCLUSION: The cross positioning method was used to calibrate the patients' head position during SMILE surgery, which reduced the axial position error and improved the accuracy of SMILE in correcting low and moderate astigmatism.

Vector analysis of toric implantable collamer lens V4c implantation in correcting moderate to high myopia with high astigmatism / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate the clinical effect of toric implantable collamer lens(TICL)V4c for correcting moderate to high myopia with high astigmatism using vector analysis and quality of life impact of refractive correction(QIRC).METHODS: Retrospective case series. A total of 55 patients(90 eyes)with moderate to high myopia and high astigmatism who received TICL V4c implantation in the refraction surgery center of ophthalmology department in our hospital from January 2019 to December 2022 were collected. Followed-up for 1 a, the uncorrected distance visual acuity(UDVA), best corrected visual acuity(BCVA)and diopters were observed. Alpins vector analysis was used to evaluate the effect of astigmatism correction, and QIRC scale was used to evaluate patients' quality of life.RESULTS: At 1 a postoperatively, the UDVA of 98% eyes was the same or better than pre-operative BCVA, the safety index was 1.11±0.14, and the efficacy index was 1.11±0.15. The angle of error of 97% of the astigmatic eyes was within ±15°. The results of vector analysis showed that correction index was 0.83±0.13, angle of error was 1.00±4.49°, and index of success was 0.21±0.15. The total higher order aberrations under a pupil diameter of 6 mm was significantly increased compared with preoperatively(P&#x003C;0.05), the QIRC score was significantly better than that before surgery(P&#x003C;0.001), and the increase of total QIRC scores was positively correlated with preoperative spherical equivalent(rs=0.215, P&#x003C;0.05), indicating that the higher degree of myopia before surgery the patients, the better the quality of life after TICL implantation.CONCLUSION: TICL V4c implantation for the correction of moderate to high myopia with high astigmatism is safe and effective, and the patients' quality of life significantly improved after surgery.

Short-term clinical results with a trifocal diffractive toric intraocular lens using an optimized preoperative and intraoperative protocol.

PURPOSE: To evaluate the short-term clinical outcomes of a specific toric diffractive trifocal intraocular lens (IOL) implanted following an optimized clinical protocol in a large population. METHODS: Retrospective analysis of 337 eyes of 231 patients (mean age, 62.2 years) undergoing cataract surgery with implantation of the trifocal diffractive IOL AT.LISA tri toric 939M/MP (Carl Zeiss Meditec). A strict and careful clinical protocol was followed, including an accurate measurement of corneal astigmatism, use of a latest generation IOL power calculator, photography-based method intraoperative control of IOL alignment and IOL reposition at 1 week postoperatively if needed. Clinical outcomes in terms of visual acuity, refraction, efficacy of astigmatic correction analysed by vector analysis and patient satisfaction were evaluated during a 3-month follow-up. RESULTS: A total of 82% and 98% of eyes achieved a postoperative uncorrected distance visual acuity of 0.00 and 0.10 logMAR or better, respectively. Furthermore, 99.7%, and 100.0% of eyes showed a postoperative spherical equivalent within ± 0.50 D and ± 1.00 D, with 97.9% of eyes having a postoperative cylinder ≤ 0.50 D. Uncorrected near and intermediate visual acuities were 0.2 logMAR or better in 89.0% and 99.1% of eyes, respectively. Mean difference vector, magnitude of error and angle of error were 0.02 ± 0.14 D, 0.02 ± 0.13 D and 0.11 ± 1.18°. Patient satisfaction was referred as high or very high by 97.6% of patients. CONCLUSIONS: The implantation of the trifocal toric IOL evaluated following a careful clinical protocol provides an efficacious visual rehabilitation and astigmatic correction, leading to high levels of patient satisfaction.

Total and segmental phase angle in a cohort of hospitalised patients with COVID-19: mortality prediction and changes throughout hospitalisation.

Body composition and phase angle (PhA) have been used to predict mortality in multiple diseases. However, little has been studied regarding segmental measurements, which could potentially help assess subtle changes in specific tissue segments. This study aimed to identify the total PhA cut-off point associated with mortality risk and changes in body composition within a week of hospitalisation in non-critical hospitalised patients with COVID-19. A cohort study was conducted where patients underwent to a complete nutritional assessment upon admission and after seven days, and followed up until hospital discharge or death. A receiver operating characteristic curve was constructed to determine the PhA cut-off point, and the Kaplan­Meier estimator was used to determine survival analysis. Segmental and complete body compositions on admission and after 7 d were compared. We included 110 patients (60 men) with a mean age of 50·5 ± 15·0 years and a median BMI of 28·5 (IQR, 25·6­33·5) kg/m2. The median length of hospital stay was 6 (IQR, 4­9) d, and the mortality rate was 13·6 %. The PhA cut-off point obtained was 4°, with significant differences in the survival rate (P < 0·001) and mortality (HR = 5·81, 95 % CI: 1·80, 18·67, P = 0·003). Segmental and whole-body compositions were negatively affected within one week of hospitalisation, with changes in the approach by the graphical method in both sexes. Nutritional status deteriorates within a week of hospitalisation. PhA < 4° is strongly associated with increased mortality in non-critical hospitalised patients with COVID-19.

Comparison of two swept-source optical coherence tomography devices, a Scheimpflug camera system and a ray-tracing aberrometer in the measurement of corneal power in patients with cataract.

PURPOSE: To assess the differences and similarities in the corneal curvature obtained by two swept-source optical coherence tomography (SS-OCT) devices, Scheimpflug imaging system and one ray tracing aberrometer in patients with cataracts. Moreover, this study aimed to compare the differences in posterior corneal (PK), total corneal (TK) and true net power (TNP) measurements among the IOLMaster 700, CASIA2, and Pentacam. METHODS: A total of 200 eyes of 200 patients (116 female, 58%) were enrolled in this study, with a mean age of 65.9 ± 9.5 years. The flattest (Kf), steepest (Ks), and mean cornal powers (Km), J0, and J45 were obtained using two SS-OCT-based biometric devices, one rotating camera system and one ray-tracing aberrometer. The PK, TK and TNP values were also measured using these devices. To evaluate the differences and similarities between the devicves, the Friedman test, Pearson correlation coefficient (r), intraclass coefficient correlation (ICC) and Bland‒Altman plots with 95% limits of agreement (LoA) were used, and boxplots and stacked histograms were generated to describe the distributions of the data. RESULTS: There were no significant differences between the IOLMaster 700 and Pentacam for any of the keratometry values. Additionally, there were no significant differences between the IOLMaster 700 and iTrace in evaluating J0 and J45. Bland‒Altman plots revealed relatively wide LoA widths, almost larger than 1 diopter for the keratometry values and almost larger than 0.5 diopter for J0 and J45 values among the four devices. In terms of PK and TK values, significant differences and low ICCs were found among the three devices. CONCLUSIONS: Although strong correlations and good agreement were found among the IOLMaster700, CASIA2, Pentacam and iTrace for Kf, Ks, Km and J0, J45, it seems that the measurements should not be used interchangeably because of the wide LoA widths and the presence of significant differences among the devices. Similarly, due to significant differences and low ICCs, the PK, TK and TNP values obtained by IOLMaster 700, CASIA2, and Pentacam should not be used interchangeably.

Vector Analysis and Prognostic Factors for Femtosecond Arcuate Keratotomy in Post-Keratoplasty Astigmatism.

Purpose: To analyze different tomographic and refractive parameters for predicting successful visual outcome following femtosecond laser-assisted arcuate keratotomy (FSAK) for post-keratoplasty astigmatism. Design: Retrospective. Methods: Retrospective study evaluating patients with astigmatism following penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK) who underwent FSAK. Vector analysis using the Alpins method was done to calculate surgically induced astigmatism (SIA). An improvement of 3 lines of Early Treatment Diabetic Retinopathy Study (ETDRS) lines was used for successful outcome. Outcome was measured at 3 months and 17 months. Results: This study included 106 eyes from 104 patients (65 males and 39 females). Mean age was 31.8±8.6 years, and 89.4% (n=93) of cases were keratoconus (KC), 3.8% (n=4) scar, 3.8% (n=4) granular dystrophy, 1.9% (n=2) post-LASIK ectasia, and 1.0% (n=1) macular dystrophy. Uncorrected visual acuity (UCVA) improved from 1.02±0.53 logarithm minimal angle of resolution (logMAR) to 0.87±0.49 logMAR (p=0.01) at 3 months and to 0.92±1.08 logMAR (p=0.57) at 17 months. Best spectacle-corrected visual acuity (BSCVA) improved from 0.41±0.30 logMAR to 0.31±0.19 logMAR (p<0.01) at 3 months and to 0.23±0.27 logMAR (p<0.01) at 17 months. Success was achieved in 50% (n=53) and 49% (n=52) at 3 and 17 months follow-up, respectively. Success group showed worse preoperative UCVA (1.21±0.56 vs 0.83±0.44 logMAR; p<0.01), worse preoperative BSCVA (0.50±0.36 vs 0.33±0.19 logMAR; p=0.01). Preoperative UCVA had an area under the curve of 0.721 (95% CI: 0.622-0.820; p< 0.01). The Youden's optimal cutoff point was 0.90 logMAR (equivalent Snellen 20/159) with 76.9% sensitivity and 35.2% specificity. Flattening index (FI) was 87% in DALK and 73% in PKP (p=0.14). Correction index (CI) was 99% and 86% (p=0.18) for DALK and PKP, respectively. Success of the astigmatic surgery for DALK and PKP was 44% vs 42% (p=0.29), respectively. Conclusion: Improvement of at least three lines was achieved in 49% of patients who underwent FSAK following PKP or DALK; this improvement was achieved in patients who had a worse preoperative UCVA.