81 research outputs found

    Steeper Iris Conicity Is Related to a Shallower Anterior Chamber: The Gutenberg Health Study

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    Purpose. To report the distribution of iris conicity (steepness of the iris cone), investigate associated factors, and test whether pseudophakia allows the iris to sink back. Methods. A population-based cross-sectional study was carried out. Ophthalmological examination including objective refraction, biometry, noncontact tonometry, and Scheimpflug imaging (Pentacam®, Oculus) was performed including automated measurement of iris conicity. 3708 phakic subjects, 144 subjects with bilateral and 39 subjects with unilateral pseudophakia were included. Multivariable analyses were carried out to determine independently associated systemic and ocular factors for iris conicity in phakic eyes. Results. Mean iris conicity was 8.28° ± 3.29° (right eyes). Statistical analysis revealed associations between steeper iris conicity and shallower anterior chamber depth, thicker human lens and higher corneal power in multivariable analysis, while older age was related to a flatter iris conicity. Refraction, axial length, central corneal thickness, pupil diameter, and intraocular pressure were not associated with iris conicity. Pseudophakia resulted in a 5.82° flatter iris conicity than in the fellow phakic eyes. Conclusions. Associations indicate a correlation between iris conicity with risk factors for angle-closure, namely, shallower anterior chamber depth and thicker human lens. In pseudophakic eyes, iris conicity is significantly lower, indicating that cataract surgery flattens the iris

    Prevalence of depression and anxiety among participants with glaucoma in a population-based cohort study : the Gutenberg Health Study

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    Background To investigate the prevalence of depression and anxiety among subjects with self-reported glaucoma and the association between self-reported glaucoma and depression respectively anxiety in a European cohort. Methods A study sample of 14,657 participants aged 35 to 74 years was investigated in a population-based cohort study. All participants reported presence or absence of glaucoma. Ophthalmological examinations were carried out in all participants and demographic and disease related information were obtained by interview. Depression was assessed with the Patient Health Questionnaire (PHQ-9), and generalized anxiety with the two screening items (GAD-2) of the short form of the GAD-7 (Generalized Anxiety Disorder-7 Scale). Prevalence of depression and generalized anxiety were investigated for subjects with and without self-reported glaucoma. Logistic regression analyses with depression, respectively anxiety as dependent variable and self-reported glaucoma as independent variable were conducted and adjusted for socio-demographic factors, systemic comorbidities (arterial hypertension, myocardial infarction, stroke, diabetes mellitus, chronic obstructive pulmonary disease, cancer), ocular diseases (cataract, macular degeneration, corneal diseases, diabetic retinopathy), visual acuity, intraocular pressure, antiglaucoma eye drops (sympathomimetics, parasympathomimetics, carbonic anhydrase inhibitors, beta-blockers, prostaglandins) and general health status. Results 293 participants (49.5% female) reported having glaucoma. Prevalence of depression among participants with and without self-reported glaucoma was 6.6% (95%-CI 4.1–10.3) respectively 7.7% (95%-CI 7.3–8.2), and for anxiety 5.3% (95%-CI 3.1–8.7) respectively 6.6% (95%-CI 6.2–7.1). Glaucoma was not associated with depression (Odds ratio 1.10, 95%-CI 0.50–2.38, p = 0.80) or anxiety (1.48, 95%-CI 0.63–3.30, p = 0.35) after adjustment for socio-demographic factors, ocular/systemic diseases, ocular parameters, antiglaucoma drugs and general health status. A restriction to self-reported glaucoma cases either taking topical antiglaucoma medications or having a history of glaucoma surgery did not alter the result. Conclusions This is the first study analyzing both depression and anxiety among glaucoma patients in a European cohort. Subjects with and without self-reported glaucoma had a similar prevalence of depression and anxiety in our population-based sample. Self-reported glaucoma was not associated with depression or anxiety. A lack of a burden of depressive symptoms may result from recruitment from a population-based sample as compared to previous study groups predominantly recruited from tertiary care hospitals

    Trainable segmentation for transmission electron microscope images of inorganic nanoparticles

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    We present a trainable segmentation method implemented within the python package ParticleSpy. The method takes user labelled pixels, which are used to train a classifier and segment images of inorganic nanoparticles from transmission electron microscope images. This implementation is based on the trainable Waikato Environment for Knowledge Analysis (WEKA) segmentation, but is written in python, allowing a large degree of flexibility and meaning it can be easily expanded using other python packages. We find that trainable segmentation offers better accuracy than global or local thresholding methods and requires as few as 100 user-labelled pixels to produce an accurate segmentation. Trainable segmentation presents a balance of accuracy and training time between global/local thresholding and neural networks, when used on transmission electron microscope images of nanoparticles. We also quantitatively investigate the effectiveness of the components of trainable segmentation, its filter kernels and classifiers, in order to demonstrate the use cases for the different filter kernels in ParticleSpy and the most accurate classifiers for different data types. A set of filter kernels is identified that are effective in distinguishing particles from background but that retain dissimilar features. In terms of classifiers, we find that different classifiers perform optimally for different image contrast; specifically, a random forest classifier performs best for high-contrast ADF images, but that QDA and Gaussian Naïve Bayes classifiers perform better for low-contrast TEM images

    The impact of pseudophakia on vision-related quality of life in the general population -The Gutenberg Health Study

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    ABSTRACT Cataract surgery is the most frequently performed surgical procedure worldwide. We aim to determine the prevalence of having implanted an artificial lens (pseudophakia) and of no lens (aphakia) and to compare visual function. As part of the Gutenberg Health study, a population-based cross-sectional study was conducted in Germany. An ophthalmological examination including slit-lamp examination was conducted. Prevalence including 95% confidential intervals were calculated and analyses were conducted for systemic and ocular associated factors with pseudophakia using multivariable logistic regression models. Vision-related quality of life was assessed using a standardized questionnaire and Rasch transformation. 14,696 people were included. Of these, 1.55% [1.36%-1.77%] had unilateral pseudophakia and 3.08% [2.81%-3.37%] had bilateral pseudophakia. Unilateral aphakia was present in 21 people and bilateral aphakia in 2 people. Pseudophakia was independently associated with age, higher body weight and lower body height, diabetes and smoking. Vision-related quality of life values were similar for those with bilateral phakia and pseudophakia but were lower for those with unilateral pseudophakia. The pseudophakia status is related to several cardiovascular risk factors, indicating a relationship to an aging effect that causes premature lens opacification. Bilateral pseudophakia can almost imitate the physiological condition of phakia except for the need to use glasses

    The impact of pseudophakia on vision-related quality of life in the general population - The Gutenberg Health Study.

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    Cataract surgery is the most frequently performed surgical procedure worldwide. We aim to determine the prevalence of having implanted an artificial lens (pseudophakia) and of no lens (aphakia) and to compare visual function.As part of the Gutenberg Health study, a population-based cross-sectional study was conducted in Germany. An ophthalmological examination including slit-lamp examination was conducted. Prevalence including 95% confidential intervals were calculated and analyses were conducted for systemic and ocular associated factors with pseudophakia using multivariable logistic regression models. Vision-related quality of life was assessed using a standardized questionnaire and Rasch transformation.14,696 people were included. Of these, 1.55% [1.36%-1.77%] had unilateral pseudophakia and 3.08% [2.81%-3.37%] had bilateral pseudophakia. Unilateral aphakia was present in 21 people and bilateral aphakia in 2 people. Pseudophakia was independently associated with age, higher body weight and lower body height, diabetes and smoking. Vision-related quality of life values were similar for those with bilateral phakia and pseudophakia but were lower for those with unilateral pseudophakia.The pseudophakia status is related to several cardiovascular risk factors, indicating a relationship to an aging effect that causes premature lens opacification. Bilateral pseudophakia can almost imitate the physiological condition of phakia except for the need to use glasses

    Operando XAFS investigation on the effect of ash deposition on three-way catalyst used in Gasoline Particulate Filters and the effect of the manufacturing process on the catalytic activity

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    Platinum group metals (PGM) such as palladium and rhodium based catalysts are currently being implemented in Gasoline Particulate Filter (GPF) autoexhaust aftertreatment systems. However, little is known about how the trapped particulate matter, such as the incombustible ash, interacts with the catalyst and so may affect its performance. This operando study follows the evolution of the Pd found in two different model GPF systems: one containing ash components extracted from a GPF and another from a catalyst washcoat prior to adhesion onto the GPF. We show that the catalytic activity of the two systems vary when compared with a 0 g ash containing GPF. Compared to the 0 g ash sample the 20 g ash containing sample had a higher CO light off temperature, in addition, an oscillation profile for CO, CO2 and O2 was observed, which is speculated to be a combination of CO oxidation, C deposition via a Boudouard Reaction and further partial oxidation of the deposited species to CO. During the ageing procedure the washcoat sample reduces NO at a lower temperature than the 0 g ash sample. However, post ageing the 0 g ash sample recovers and both samples reduce NO at 310 circleC. In comparison, the 20 g ash GPF sample maintains a higher NO reduction temperature of 410 circleC post ageing, implying that the combination of high temperature ageing and presence of ash has an irreversible negative effect on catalyst performance

    Dynamics at polarized carbon dioxide-iron oxyhydroxide interfaces unveil the origin of multicarbon product formation

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    Surface-sensitive ambient pressure X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy combined with an electrocatalytic reactivity study, multilength-scale electron microscopy, and theoretical modeling provide insights into the gas-phase selective reduction of carbon dioxide to isopropanol on a nitrogen-doped carbon-supported iron oxyhydroxide electrocatalyst. Dissolved atomic carbon forms at relevant potentials for carbon dioxide reduction from the reduction of carbon monoxide chemisorbed on the surface of the ferrihydrite-like phase. Theoretical modeling reveals that the ferrihydrite structure allows vicinal chemisorbed carbon monoxide in the appropriate geometrical arrangement for coupling. Based on our observations, we suggest a mechanism of three-carbon-atom product formation, which involves the intermediate formation of atomic carbon that undergoes hydrogenation in the presence of hydrogen cations upon cathodic polarization. This mechanism is effective only in the case of thin ferrihydrite-like nanostructures coordinated at the edge planes of the graphitic support, where nitrogen edge sites stabilize these species and lower the overpotential for the reaction. Larger ferrihydrite-like nanoparticles are ineffective for electron transport

    Visualization and Quantitative Analysis of Reconstituted Tight Junctions Using Localization Microscopy

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    Tight Junctions (TJ) regulate paracellular permeability of tissue barriers. Claudins (Cld) form the backbone of TJ-strands. Pore-forming claudins determine the permeability for ions, whereas that for solutes and macromolecules is assumed to be crucially restricted by the strand morphology (i.e., density, branching and continuity). To investigate determinants of the morphology of TJ-strands we established a novel approach using localization microscopy

    PuLSE:Quality control and quantification of peptide sequences explored by phage display libraries

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    The design of highly diverse phage display libraries is based on assumption that DNA bases are incorporated at similar rates within the randomized sequence. As library complexity increases and expected copy numbers of unique sequences decrease, the exploration of library space becomes sparser and the presence of truly random sequences becomes critical. We present the program PuLSE (Phage Library Sequence Evaluation) as a tool for assessing randomness and therefore diversity of phage display libraries. PuLSE runs on a collection of sequence reads in the fastq file format and generates tables profiling the library in terms of unique DNA sequence counts and positions, translated peptide sequences, and normalized 'expected' occurrences from base to residue codon frequencies. The output allows at-a-glance quantitative quality control of a phage library in terms of sequence coverage both at the DNA base and translated protein residue level, which has been missing from toolsets and literature. The open source program PuLSE is available in two formats, a C++ source code package for compilation and integration into existing bioinformatics pipelines and precompiled binaries for ease of use

    Gender Differences and the Impact of Partnership and Children on Quality of Life During the COVID-19 Pandemic

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    Objectives: The COVID-19 pandemic and its protective measures have changed the daily lives of families and may have affected quality of life (QoL). The aim of this study was to analyze gender differences in QoL and to examine individuals living in different partnership and family constellations.Methods: Data from the Gutenberg COVID-19 cohort study (N = 10,250) with two measurement time points during the pandemic (2020 and 2021) were used. QoL was assessed using the EUROHIS-QOL questionnaire. Descriptive analyses and autoregressive regressions were performed.Results: Women reported lower QoL than men, and QoL was significantly lower at the second measurement time point in both men and women. Older age, male gender, no migration background, and higher socioeconomic status, as well as partnership and children (especially in men), were protective factors for QoL. Women living with children under 14 and single mothers reported significantly lower QoL.Conclusion: Partnership and family were protective factors for QoL. However, women with young children and single mothers are vulnerable groups for lower QoL. Support is especially needed for women with young children
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