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Multimodal additive manufacturing of biomimetic tympanic membrane replacements with near tissue-like acousto-mechanical and biological properties
No full textThe three additive manufacturing techniques fused deposition modeling, gel plotting and melt electrowriting were combined to develop a mimicry of the tympanic membrane (TM) to tackle large TM perforations caused by chronic otitis media. The mimicry of the collagen fiber orientation of the TM was accompanied by a study of multiple funnel-shaped mimics of the TM morphology, resulting in mechanical and acoustic properties similar to those of the eardrum. For the different 3D printing techniques used, the process parameters were optimized to allow reasonable microfiber arrangements within the melt electrowriting setup. Interestingly, the fiber pattern was less important for the acousto-mechanical properties than the overall morphology. Furthermore, the behavior of keratinocytes and fibroblasts is crucial for the repair of the TM, and an in vitro study showed a high biocompatibility of both primary cell types while mimicking the respective cell layers of the TM. A simulation of the in vivo ingrowth of both cell types resulted in a cell growth orientation similar to the original collagen fiber orientation of the TM. Overall, the combined approach showed all the necessary parameters to support the growth of a neo-epithelial layer with a similar structure and morphology to the original membrane. It therefore offers a suitable alternative to autologous materials for the treatment of chronic otitis media
Wegweiser für werdende Eltern
No full textDas Familienbegleitheft 1 des Jugendamtes des Landkreises Zwickau ist für Schwangere, Paare mit Kinderwunsch sowie Schwangere und werdende Väter in Not gedacht
Wegweiser für Eltern und Familien mit Kindern und Jugendlichen von 7 bis 18 Jahren
No full textDas Familienbegleitheft 3 des Jugendamtes des Landkreises Zwickau hält Informationen für Eltern mit Kindern vom 7. bis zum 18. Lebensjahr bereit
Development of yarns from recycled carbon fiber based on friction spinning technology with specific properties for thermoset composites
No full textBecause of a growing demand and usage of carbon fiber, effective methods to re-use waste and recycled carbon fiber recoverable either from process scraps or from end-of-life components are attracting increased attention. The development of different hybrid yarn structures consisting of recycled carbon fiber and thermoplastic fibers (recycled carbon fiber content approx. 50% by weight) for thermoplastic composites have been reported earlier. Yarns with high recycled carbon fiber content (>90% by weight) required for thermoset composites are still not realizable due to high shortening in recycled carbon fiber length (≥70%) during different processing steps of spinning. The reason lies in low shear strength, smooth fiber surface and high brittleness of recycled carbon fiber. Second, a lack of crimp in recycled carbon fiber leads to drafting errors during the drawing and spinning process. In this paper, the spinning limit regarding the core to sheath ratio of noble yarns with a recycled carbon fiber content greater than 90% by weight based on friction spinning technology for thermoset composites is reported. Slivers of recycled carbon fiber solely required for the development of yarns are produced on carding and drawing machines optimized for the gentle processing of recycled carbon fiber. Furthermore, different spinning parameters such as spinning drum speed and suction air pressure are investigated and their effect on tensile properties of yarn is analyzed. The results show that yarns with high recycled carbon fiber content (>90% by weight) can be produced with reproducible quality on the DREF-3000 friction spinning machine
Erosion behaviour of human, bovine and equine dental hard tissues
No full textDental hard tissues from different species are used in dental research, but little is known about their comparability. The aim of this study was to compare the erosive behaviour of dental hard tissues (enamel, dentin) obtained from human, bovine and equine teeth. In addition, the protective effect of the pellicle on each hard tissue under erosive conditions was determined. In situ pellicle formation was performed for 30 min on enamel and dentin samples from all species in four subjects. Calcium and phosphate release was assessed during 120 s of HCl incubation on both native and pellicle-covered enamel and dentin samples. SEM and TEM were used to examine surface changes in native enamel and dentin samples after acid incubation and the ultrastructure of the pellicle before and after erosive exposure. In general, bovine enamel and dentin showed the highest degree of erosion after acid exposure compared to human and equine samples. Erosion of human primary enamel tended to be higher than that of permanent teeth, whereas dentin showed the opposite behaviour. SEM showed that eroded equine dentin appeared more irregular than human or bovine dentin. TEM studies showed that primary enamel appeared to be most susceptible to erosion
Health literacy and information needs among German skin cancer patients in comparison to people without skin cancer: A survey
No full textBackground
An increasing number of patients are seeking health information on the internet. Health literacy and the quality of information are crucial to enable patients to find relevant high-quality information.
Objectives
To investigate the relevance of quality criteria for health information and to determine the health literacy of skin cancer patients (SC) in comparison to those without skin cancer (NSC).
Methods
Between December 2021 until February 2022 we undertook an online survey on the importance of multiple criteria to investigate the relevance of quality criteria of online health information. SC and NSC were eligible for participation. The questionnaire assessed participants´ health information-seeking behavior and the evaluation of relevance of quality criteria for health information on a 5-point-LIKERT-Scale. The participants´ health literacy was measured according to the health literacy measurement scale ranging from 0-100. Comparisons between SC and NSC were investigated with t-tests.
Results
We retrieved data from 268 participants, of whom 98 (38%) were SC. Participants assigned the highest relevance to the health information topics treatment (4.7 ± 0.64) and effects of a disease (4.49 ± 0.76). Participants ranked the content of information with a mean of 4.72 (±0.57) to be the most relevant criterion, followed by objectivity (4.61 ± 0.67) and completeness of the information (4.59 ± 0.61). Participants showed the highest competence in understanding of information (62.4 ± 22.5) and in disease prevention (58.32 ± 22.9). They reached low values in accessing health related information (46.78 ± 25.62) and appraising it (33.16 ± 20.11). Subgroup analysis indicated that SC had a greater need for practical information that is helpful in dealing with a disease compared to NSC. They showed significantly lower health literacy than NSC.
Conclusions
Our study documents that SC and NSC have a high need for different dimensions of quality of health information. These differences in the importance of criteria should be considered in the development of future targeted health information
Presymptomatic type 1 diabetes and disease severity at onset: Letter
No full textTo the Editor: The recent fndings of Hummel et al demonstrate the potential clinical benefts of identifying children with presymptomatic type 1 diabetes [1]. The authors compared children who developed type 1 diabetes after a previous diagnosis of presymptomatic type 1 diabetes in the Fr1da study with those in a registry cohort of children diagnosed without a prediagnosis [aus dem Brief
Framed Curves, Ribbons, and Parallel Transport on the Sphere
No full textWe consider curves γ : [0, 1] → R3 endowed with an adapted orthonormal frame r : [0, 1] → SO(3). We wish to deform such framed curves (γ ,r) while preserving two contraints: a local constraint prescribing one of its ‘curvatures’ (i.e., off-diagonal elements ofr r T ), and a global constraint prescribing the initial and terminal values of γ and r. We proceed in two stages. First we deform the frame r in a way that is naturally compatible with the constraints on r, by interpreting the local constraint in terms of parallel transport on the sphere. This provides a link to the differential geometry of surfaces. The deformation of the base curve γ is achieved in a second step, by means of a suitable reparametrization of the frame. We illustrate this deformation procedure by providing some applications: first, we characterize the boundary conditions on (γ ,r) that are accessible without violating the local constraint; then, we provide a short proof of a smooth approximation result for framed curves satisfying both the differential and the global constraints. Finally, we also apply these ideas to elastic ribbons with nonzero width
Carbon nanotube neurotransistors with ambipolar memory and learning functions
No full textIn recent years, neuromorphic computing has gained attention as a promising approach to enhance computing efficiency. Among existing approaches, neurotransistors have emerged as a particularly promising option as they accurately represent neuron structure, integrating the plasticity of synapses along with that of the neuronal membrane. An ambipolar character could offer designers more flexibility in customizing the charge flow to construct circuits of higher complexity. We propose a novel design for an ambipolar neuromorphic transistor, utilizing carbon nanotubes as the semiconducting channel and an ion-doped sol–gel as the polarizable gate dielectric. Due to its tunability and high dielectric constant, the sol–gel effectively modulates the conductivity of nanotubes, leading to efficient and controllable short-term potentiation and depression. Experimental results indicate that the proposed design achieves reliable and tunable synaptic responses with low power consumption. Our findings suggest that the method can potentially provide an efficient solution for realizing more adaptable cognitive computing systems
Antifibrotic Soluble Thy-1 Correlates with Renal Dysfunction in Chronic Kidney Disease
No full textKidney fibrosis is a major culprit in the development and progression of chronic kidney disease (CKD), ultimately leading to the irreversible loss of organ function. Thymocyte differentiation antigen-1 (Thy-1) controls many core functions of fibroblasts relevant to fibrogenesis but is also found in a soluble form (sThy-1) in serum and urine. We investigated the association of sThy-1 with clinical parameters in patients with CKD receiving hemodialysis treatment compared to individuals with a preserved renal function. Furthermore, Thy-1 tissue expression was detected in a mouse model of diabetic CKD (eNOS-/-; db/db) and non-diabetic control mice (eNOS-/-). Serum and urinary sThy-1 concentrations significantly increased with deteriorating renal function, independent of the presence of diabetes. Serum creatinine is the major, independent, and inverse predictor of serum sThy-1 levels. Moreover, sThy-1 is not only predicted by markers of renal function but is also itself an independent and strong predictor of markers of renal function, i.e., serum creatinine. Mice with severe diabetic CKD show increased Thy-1 mRNA and protein expression in the kidney compared to control animals, as well as elevated urinary sThy-1 levels. Pro-fibrotic mediators, such as interleukin (IL)-4, IL-13, IL-6 and transforming growth factor β, increase Thy-1 gene expression and release of sThy-1 from fibroblasts. Our data underline the role of Thy-1 in the control of kidney fibrosis in CKD and raise the opportunity that Thy-1 may function as a renal antifibrotic factor