Objective The majority of wound infections after median sternotomy in obese patients are triggered by the breakdown of skin sutures and subsequent seepage of skin flora. The purpose of this study was ...to evaluate negative pressure wound dressing treatment for the prevention of infection. We hypothesized that negative pressure wound dressing treatment for 6 to 7 days applied immediately after skin closure reduces the numbers of wound infections. Methods In a prospective study, 150 consecutive obese patients (body mass index ≥ 30) with cardiac surgery performed via median sternotomy were analyzed. In the negative pressure wound dressing treatment group (n = 75), a foam dressing (Prevena, KCI, Wiesbaden, Germany) was placed immediately after skin suturing, and negative pressure of −125 mm Hg was applied for 6 to 7 days. In the control group (n = 75), conventional wound dressings were used. The primary end point was wound infection within 90 days. Mann–Whitney U test and Fisher exact test were used. Freedom from infection was estimated by Kaplan–Meier analysis. Results Three of 75 patients (4%) with continuous negative pressure wound dressing treatment had wound infections compared with 12 of 75 patients (16%) with conventional sterile wound dressing ( P = .0266; odds ratio, 4.57; 95% confidence interval, 1.23-16.94). Wound infections with Gram-positive skin flora were found in only 1 patient in the negative pressure wound dressing treatment group compared with 10 patients in the control group ( P = .0090; odds ratio, 11.39; 95% confidence interval, 1.42-91.36). Conclusions Negative pressure wound dressing treatment over clean, closed incisions for the first 6 to 7 postoperative days significantly reduces the incidence of wound infection after median sternotomy in a high-risk group of obese patients.
Lithium plating in commercial LiNi sub(1/3)Mn sub(1/3)Co sub(1/3)O sub(2)/graphite cells at sub-ambient temperatures is studied by neutron diffraction at Stress-Spec, MLZ. Li plating uses part of the ...active lithium in the cell and competes with the intercalation of lithium into graphite. As a result, the degree of graphite lithiation during and after charge is lower. Comparison of graphite lithiation after a C/5 charging cycle fast enough to expect a considerable amount of Li plating with a much slower C/30 reference cycle reveals a lower degree of graphite lithiation in the first case; neutron diffraction shows less LiC sub(6) and more LiC sub(12) is present. If the cell is subjected to a 20 h rest period after charge, a gradual transformation of remaining LiC sub(12) to LiC sub(6) can be observed, indicating Li diffusion into the graphite. During the rest period after the C/5 charging cycle, the degree of graphite lithiation can be estimated to increase by 17%, indicating at least 17% of the active lithium is plated. Data collected during discharge immediately after C/5 charging give further evidence of the presence and amount of metallic lithium: in this case 19% of discharge capacity originates from the oxidation of metallic lithium. Also, lithium oxidation can be directly related to the high voltage plateau observed during discharge in case of lithium plating.
The vertebrate eye allows to capture an enormous amount of detail about the surrounding world which can only be exploited with sophisticated central information processing. Furthermore, vision is an ...active process due to head and eye movements that enables the animal to change the gaze and actively select objects to investigate in detail. The entire system requires a coordinated coevolution of its parts to work properly. Ray-finned fishes offer a unique opportunity to study the evolution of the visual system due to the high diversity in all of its parts. Here, we are bringing together information on retinal specializations (fovea), central visual centers (brain morphology studies), and eye movements in a large number of ray-finned fishes in a cladistic framework. The nucleus glomerulosus-inferior lobe system is well developed only in Acanthopterygii. A fovea, independent eye movements, and an enlargement of the nucleus glomerulosus-inferior lobe system coevolved at least five times independently within Acanthopterygii. This suggests that the nucleus glomerulosus-inferior lobe system is involved in advanced object recognition which is especially well developed in association with a fovea and independent eye movements. None of the non-Acanthopterygii have a fovea (except for some deep sea fish) or independent eye movements and they also lack important parts of the glomerulosus-inferior lobe system. This suggests that structures for advanced visual object recognition evolved within ray-finned fishes independent of the ones in tetrapods and non-ray-finned fishes as a result of a coevolution of retinal, central, and oculomotor structures.
To investigate the prevalence of depressive symptoms in rheumatoid arthritis (RA) patients using two previously validated questionnaires in a large patient sample, and to evaluate depressive symptoms ...in the context of clinical characteristics (e.g. remission of disease) and patient-reported impact of disease.
In this cross-sectional study, the previously validated Patient Health Questionnaire (PHQ-9) and Beck-Depression Inventory II (BDI-II) were used to assess the extent of depressive symptoms in RA patients. Demographic background, RA disease activity score (DAS28), RA impact of disease (RAID) score, comorbidities, anti-rheumatic therapy and antidepressive treatment, were recorded. Cut-off values for depressive symptomatology were PHQ-9 ≥5 or BDI-II ≥14 for mild depressive symptoms or worse and PHQ-9 ≥ 10 or BDI-II ≥ 20 for moderate depressive symptoms or worse. Prevalence of depressive symptomatology was derived by frequency analysis while factors independently associated with depressive symptomatology were investigated by using multiple logistic regression analyses. Ethics committee approval was obtained, and all patients provided written informed consent before participation.
In 1004 RA-patients (75.1% female, mean±SD age: 61.0±12.9 years, mean disease duration: 12.2±9.9 years, DAS28 (ESR): 2.5±1.2), the prevalence of depressive symptoms was 55.4% (mild or worse) and 22.8% (moderate or worse). Characteristics independently associated with depressive symptomatology were: age <60 years (OR = 1.78), RAID score >2 (OR = 10.54) and presence of chronic pain (OR = 3.25). Of patients classified as having depressive symptoms, only 11.7% were receiving anti-depressive therapy.
Mild and moderate depressive symptoms were common in RA patients according to validated tools. In routine clinical practice, screening for depression with corresponding follow-up procedures is as relevant as incorporating these results with patient-reported outcomes (e.g. symptom state), because the mere assessment of clinical disease activity does not sufficiently reflect the prevalence of depressive symptoms.
This study is registered in the Deutsches Register Klinischer Studien (DRKS00003231) and ClinicalTrials.gov (NCT02485483).
With neutron diffraction, the local stress and texture of metallic components can be analyzed non-destructively. For both, highly accurate positioning of the sample is essential, requiring the ...measurement at the same sample location from different directions. Current sample-positioning systems in neutron diffraction instruments combine XYZ tables and Eulerian cradles to enable the accurate six-degree-of-freedom (6DoF) handling of samples. However, these systems are not flexible enough. The choice of the rotation center and their range of motion are limited. Industrial six-axis robots have the necessary flexibility, but they lack the required absolute accuracy. This paper proposes a visual servoing system consisting of an industrial six-axis robot enhanced with a high-precision multi-camera tracking system. Its goal is to achieve an absolute positioning accuracy of better than 50μm. A digital twin integrates various data sources from the instrument and the sample in order to enable a fully automatic measurement procedure. This system is also highly relevant for other kinds of processes that require the accurate and flexible handling of objects and tools, e.g., robotic surgery or industrial printing on 3D surfaces.
Fluorescence microscopy is indispensable in many areas of science, but until recently, diffraction has limited the resolution of its lens-based variant. The diffraction barrier has been broken by a ...saturated depletion of the marker's fluorescent state by stimulated emission, but this approach requires picosecond laser pulses of$GW/cm^2$intensity. Here, we demonstrate the surpassing of the diffraction barrier in fluorescence microscopy with illumination intensities that are eight orders of magnitude smaller. The subdiffraction resolution results from reversible photoswitching of a marker protein between a fluorescence-activated and a nonactivated state, whereby one of the transitions is accomplished by means of a spatial intensity distribution featuring a zero. After characterizing the switching kinetics of the used marker protein asFP595, we demonstrate the current capability of this RESOLFT (reversible saturable optical fluorescence transitions) type of concept to resolve 50-100 nm in the focal plane. The observed resolution is limited only by the photokinetics of the protein and the perfection of the zero. Our results underscore the potential to finally achieve molecular resolution in fluorescence microscopy by technical optimization.
Atomisation of an aqueous solution for tablet film coating is a complex process with multiple factors determining droplet formation and properties. The importance of droplet size for an efficient ...process and a high quality final product has been noted in the literature, with smaller droplets reported to produce smoother, more homogenous coatings whilst simultaneously avoiding the risk of damage through over-wetting of the tablet core. In this work the effect of droplet size on tablet film coat characteristics was investigated using X-ray microcomputed tomography (XμCT) and confocal laser scanning microscopy (CLSM). A quality by design approach utilising design of experiments (DOE) was used to optimise the conditions necessary for production of droplets at a small (20 μm) and large (70 μm) droplet size. Droplet size distribution was measured using real-time laser diffraction and the volume median diameter taken as a response. DOE yielded information on the relationship three critical process parameters: pump rate, atomisation pressure and coating-polymer concentration, had upon droplet size. The model generated was robust, scoring highly for model fit (R2 = 0.977), predictability (Q2 = 0.837), validity and reproducibility. Modelling confirmed that all parameters had either a linear or quadratic effect on droplet size and revealed an interaction between pump rate and atomisation pressure. Fluidised bed coating of tablet cores was performed with either small or large droplets followed by CLSM and XμCT imaging. Addition of commonly used contrast materials to the coating solution improved visualisation of the coating by XμCT, showing the coat as a discrete section of the overall tablet. Imaging provided qualitative and quantitative evidence revealing that smaller droplets formed thinner, more uniform and less porous film coats.
Phase-locking to the temporal envelope of speech is associated with envelope processing and speech perception. The phase-locked activity of the auditory pathway, across modulation frequencies, is ...generally assessed at group level and shows a decrease in response magnitude with increasing modulation frequency. With the exception of increased activity around 40 and 80 to 100 Hz. Furthermore, little is known about the phase-locked response patterns to modulation frequencies ≤ 20 Hz, which are modulations predominately present in the speech envelope. In the present study we assess the temporal modulation transfer function (TMTF
) of the phase-locked activity of the auditory pathway, from 0.5 to 100 Hz at a high-resolution and by means of auditory steady-state responses. Although the group-averaged TMTF
corresponds well with those reported in the literature, the individual TMTF
shows a remarkable intersubject variability. This intersubject variability is especially present for ASSRs that originate from the cortex and are evoked with modulation frequencies ≤ 20 Hz. Moreover, we found that these cortical phase-locked activity patterns are robust over time. These results show the importance of the individual TMTF
when assessing phase-locked activity to envelope fluctuations, which can potentially be used as a marker for auditory processing.
In extreme environments, microbial organisms reside in pockets with locally habitable conditions. Micro-climates conducive to the persistence of life in an otherwise inhospitable ...environment—“refugia”—are spatially restricted and can be micro- to centimeters in extent. If martian microbes are preserved in fossil refugia, this presents a double-edged sword for biosignature exploration: these locations will be specific and targetable but small and difficult to find. To better understand what types of features could be refugia in martian salt-encrusted basins, we explore a case study of two terrestrial habitats in salt-encrusted paleo-lake basins (salars): Salar Grande (SG) in the Atacama Desert and Salar de Pajonales (SdP) in the Altiplano Puna plateau of Chile. We review the formation of salt constructs within SG and SdP, which are the features that serve as refugia in those salars, and we explore the connection between the formation of salt constructs at the local scale with the larger-scale geologic phenomena that enable their formation. Our evaluation of terrestrial salars informs an assessment of which chloride basins on Mars might have had a high potential to form life-hosting salt constructs and may preserve biosignatures, or even host extant life. Our survey of martian salars identifies 102 salars in regions with a geographic context conducive to the formation of salt constructs, of which 17 have HiRISE coverage. We investigate these 17 martian salars with HiRISE coverage and locate the presence of possible salt constructs in 16 of them. Salt constructs are features that have may have been continuously habitable for the past ~3.8 Byr, have exceptional preservation potential, and are accessible by robotic exploration. Future work could explore in detail the mechanisms involved in the formation of the topographic features we identified in salt-encrusted basins on Mars to test the hypothesis that they are salt constructs.
Gypsum‐lined degassing holes in tumuli Hofmann, Michael H.; Hinman, Nancy W.; Phillips, Michael ...
Earth surface processes and landforms,
December 2023, 2023-12-00, 20231201, Letnik:
48, Številka:
15
Journal Article
Recenzirano
Small, circular holes, lined with a thin gypsum veneer, and closely associated with gypsum tumuli (domes), occur at Salar de Pajonales, a salt flat in the northern Andes, Chile. We propose a model in ...which the formation of the gypsum‐lined holes, and less commonly the formation of the tumuli itself, is controlled by the unique juxtaposition of physiographic, geologic and hydrologic conditions. On a regional scale, Salar de Pajonales is unusual compared to other salars, as it is located close to a large magmatic inflation centre (Lazufre), lies along strike of major regional structural trends, is a large ephemeral lake and contains high salt concentrations. On a basin scale, the lined holes are only present along strike of lineaments that are directly linked to the local stress regime. In turn, these lineaments control the location of degassing and subsequently the formation of the lined holes in the gypsum tumuli and, in part, the tumuli themselves.
The purpose of this paper is to (1) present peculiar lined‐holes in gypsum tumuli from Salar de Pajonales, Chile, (2) compare their spatial distribution to physiographic, geologic and hydrologic parameters to constrain the controls on formation, (3) propose a new model of the formation of the lined‐holes that is compatible with the observations and the collocation and synchronous relationships and constraints and (4) provide a new exploration model that could assist with search for life on Mars and other planets.
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