Synthesis and Characterization of Novel Isosorbide‐Based Polyester Derivatives Decorated with α ‐Acyloxy Amides

The synergy of multicomponent reactions (MCRs) and metathesis chemistry is applied for the synthesis of bio-based functional isosorbide polymers (i.e., polyesters) decorated with α-acyloxy amide motif. The chemical structure of the polyesters that are not accessible by any other conventional methodologies is characterized in-depth via nuclear magnetic resonance, size-exclusion chromatography, and attenuated total reflectance infrared spectroscopy. It is also observed that the “biomass-derived” carbon % of the polymers varied between 66.2 and 76.9. Moreover, the thermal properties of the novel isosorbide-based polymers are investigated via thermogravimetric analysis and differential scanning calorimetry, revealing that the polymers are in the amorphous state, identified by the glass transition temperature (T$_g$) values below the human body temperature. The mechanical properties and the biocompatibility of the functional novel polyester derivative with the highest “biomass-derived” carbon % are evaluated via dynamic mechanical analysis and cytotoxicity test. The exemplary polymer is biocompatible with chondrocyte cells in the conditions used in the tests. In summary, the complementary nature of isosorbide derivatives with MCRs and metathesis chemistry is utilized to illustrate the potential utility of isosorbide as a building block for polymers with prospective biomedical application (namely, as novel cartilage materials)

Correlation between weather and incidence of selected ophthalmological diagnoses: a database analysis

Purpose: Our aim was to correlate the overall patient volume and the incidence of several ophthalmological diseases in our emergency department with weather data. Patients and methods: For data analysis, we used our clinical data warehouse and weather data. We investigated the weekly overall patient volume and the average weekly incidence of all encoded diagnoses of "conjunctivitis", "foreign body", "acute iridocyclitis", and "corneal abrasion". A Spearman's correlation was performed to link these data with the weekly average sunshine duration, temperature, and wind speed. Results: We noticed increased patient volume in correlation with increasing sunshine duration and higher temperature. Moreover, we found a positive correlation between the weekly incidences of conjunctivitis and of foreign body and weather data. Conclusion: The results of this data analysis reveal the possible influence of external conditions on the health of a population and can be used for weather-dependent resource allocation

Synthesis and Characterization of Novel Isosorbide‐Based Polyester Derivatives Decorated with α ‐Acyloxy Amides

The synergy of multicomponent reactions (MCRs) and metathesis chemistry is applied for the synthesis of bio-based functional isosorbide polymers (i.e., polyesters) decorated with α-acyloxy amide motif. The chemical structure of the polyesters that are not accessible by any other conventional methodologies is characterized in-depth via nuclear magnetic resonance, size-exclusion chromatography, and attenuated total reflectance infrared spectroscopy. It is also observed that the “biomass-derived” carbon % of the polymers varied between 66.2 and 76.9. Moreover, the thermal properties of the novel isosorbide-based polymers are investigated via thermogravimetric analysis and differential scanning calorimetry, revealing that the polymers are in the amorphous state, identified by the glass transition temperature (T$_g$) values below the human body temperature. The mechanical properties and the biocompatibility of the functional novel polyester derivative with the highest “biomass-derived” carbon % are evaluated via dynamic mechanical analysis and cytotoxicity test. The exemplary polymer is biocompatible with chondrocyte cells in the conditions used in the tests. In summary, the complementary nature of isosorbide derivatives with MCRs and metathesis chemistry is utilized to illustrate the potential utility of isosorbide as a building block for polymers with prospective biomedical application (namely, as novel cartilage materials)

Characterization of Distinct Chondrogenic Cell Populations of Patients Suffering from Microtia Using Single-Cell Micro-Raman Spectroscopy

Microtia is a congenital condition of abnormal development of the outer ear. Tissue engineering of the ear is an alternative treatment option for microtia patients. However, for this approach, the identification of high regenerative cartilage progenitor cells is of vital importance. Raman analysis provides a novel, non-invasive, label-free diagnostic tool to detect distinctive biochemical features of single cells or tissues. Using micro-Raman spectroscopy, we were able to distinguish and characterize the particular molecular fingerprints of differentiated chondrocytes and perichondrocytes and their respective progenitors isolated from healthy individuals and microtia patients. We found that microtia chondrocytes exhibited lower lipid concentrations in comparison to healthy cells, thus indicating the importance of fat storage. Moreover, we suggest that collagen is a useful biomarker for distinguishing between populations obtained from the cartilage and perichondrium because of the higher spectral contributions of collagen in the chondrocytes compared to perichondrocytes from healthy individuals and microtia patients. Our results represent a contribution to the identification of cell markers that may allow the selection of specific cell populations for cartilage tissue engineering. Moreover, the observed differences between microtia and healthy cells are essential for gaining better knowledge of the cause of microtia. It can be useful for designing novel treatment options based on further investigations of the discovered biochemical substrate alterations

Enhanced cellular migration and prolonged chondrogenic differentiation in decellularized cartilage scaffolds under dynamic culture conditions

Lesions of aural, nasal and tracheal cartilage are frequently reconstructed by complex surgeries which are based on harvesting autologous cartilage from other locations such as the rib. Cartilage tissue engineering (CTE) is regarded as a promising alternative to attain vital cartilage. Nevertheless, CTE with nearly natural properties poses a significant challenge to research due to the complex reciprocal interactions between cells and extracellular matrix which have to be imitated and which are still not fully understood. Thus, we used a custom-made glass bioreactor to enhance cell migration into decellularized porcine cartilage scaffolds (DECM) and mimic physiological conditions. The DECM seeded with human nasal chondrocytes (HPCH) were cultured in the glass reactor for 6 weeks and examined by histological and immunohistochemical staining, biochemical analyses and real time-PCR at 14, 28 and 42 days. The migration depth and the number of migrated cells were quantified by computational analysis. Compared to the static cultivation, the dynamic culture (DC) fostered migration of HPCH into deeper tissue layers. Furthermore, cultivation in the bioreactor enhanced differentiation of the cells during the first 14 days, but differentiation diminished in the course of further cultivation. We consider the DC in the presented bioreactor as a promising tool to facilitate CTE and to help to better understand the complex physiological processes during cartilage regeneration. Maintaining differentiation of chondrocytes and improving cellular migration by further optimizing culture conditions is an important prerequisite for future clinical application

Dark exciton anti-funneling in atomically thin semiconductors

Strain engineering can manipulate the propagation of excitons in atomically thin transition metal dichalcogenides. Here, the authors observe an anti-funnelling behavior, i.e., the exciton photoluminescence moves away from high-strain regions, and attribute it to the dominating role of propagating dark excitons. Transport of charge carriers is at the heart of current nanoelectronics. In conventional materials, electronic transport can be controlled by applying electric fields. Atomically thin semiconductors, however, are governed by excitons, which are neutral electron-hole pairs and as such cannot be controlled by electrical fields. Recently, strain engineering has been introduced to manipulate exciton propagation. Strain-induced energy gradients give rise to exciton funneling up to a micrometer range. Here, we combine spatiotemporal photoluminescence measurements with microscopic theory to track the way of excitons in time, space and energy. We find that excitons surprisingly move away from high-strain regions. This anti-funneling behavior can be ascribed to dark excitons which possess an opposite strain-induced energy variation compared to bright excitons. Our findings open new possibilities to control transport in exciton-dominated materials. Overall, our work represents a major advance in understanding exciton transport that is crucial for technological applications of atomically thin materials

Vasohibin inhibits angiogenic sprouting in vitro and supports vascular maturation processes in vivo

<p>Abstract</p> <p>Background</p> <p>The murine homologue of human vasohibin (mVASH1), a putative antiangiogenic protein, was investigated for its effects on <it>in vitro </it>and <it>in vivo </it>angiogenesis.</p> <p>Methods</p> <p>Cell growth and migration were analyzed in murine fibroblasts, smooth muscle cells and endothelial cells. Angiogenic sprouting was studied in human umbilical vein endothelial cells (HUVECs) in the spheroid sprouting assay. <it>In vivo </it>effects on blood vessel formation were investigated in the chorioallantoic membrane (CAM) assay and in the C57BL/6 melanoma xenograft model.</p> <p>Results</p> <p>Purified murine and human VASH1 protein induced apoptosis of murine fibroblasts <it>in vitro</it>, but not of vascular aortic smooth muscle cells (AoSMC) or endothelial cells. Adenoviral overexpression of murine and human VASH1 inhibited capillary sprouting of HUVECs in the spheroid assay. Administration of recombinant murine and human VASH1 inhibited growth of large vessels in the CAM assay and promoted the formation of a dense, fine vascular network. Murine VASH1-overexpressing B16F10 melanomas displayed a reduction in large vessels and vascular area. Moreover, tumors showed more microvessels that stained positive for the mural cell markers α-smooth muscle cell actin (ASMA) and proteoglycan (NG2).</p> <p>Conclusion</p> <p>Our data imply that murine VASH1 causes angiogenic remodelling by inhibiting angiogenic sprouting and large vessel growth, thereby supporting the formation of a vascular bed consisting predominantly of mature microvessels.</p

Die deutsche Wasserstoffpolitik und ihre Auswirkungen auf die Wasserstoffwirtschaft und alternative Transformationspfade

DIE DEUTSCHE WASSERSTOFFPOLITIK UND IHRE AUSWIRKUNGEN AUF DIE WASSERSTOFFWIRTSCHAFT UND ALTERNATIVE TRANSFORMATIONSPFADE Die deutsche Wasserstoffpolitik und ihre Auswirkungen auf die Wasserstoffwirtschaft und alternative Transformationspfade / Kern, Florian (Rights reserved) ( -