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3D printing technologies have matured to produce complex structures, still they are often limited to static materials. Introducing alkoxyamine bonds into 3D printed structures offers unprecedented possibilities for post‐synthetic modification through nitroxide exchange reaction and nitroxide‐mediated polymerization. This study provides a comprehensive molecular and macroscopic characterization of 3D‐printed alkoxyamine‐containing dynamic covalent adaptable networks. The study provides new insights into their dynamic structural and mechanical alterations, making them promising candidates for advanced applications ranging from biomedical engineering to flexible electronics. [ABSTRACT FROM AUTHOR]

The preparation of polymers containing sulfur–nitrogen bond derivatives, particularly 2,2,6,6‐tetramethylpiperidine‐1‐sulfanyl (TEMPS) dimers (i.e., BiTEMPS), has been limited to free‐radical or conventional step‐growth polymerization as result of the inherent thermal lability of the BiTEMPS unit. Accordingly, a novel poly(diaminodisulfide) possessing the BiTEMPS functional group is synthesized via acyclic diene metathesis (ADMET) polymerization at 65–75 °C within 3 h with precise control over the primary polymer structure. Polymer is isolated with an Mn of 20 400 g mol−1 and Ð of 1.9. Importantly, detailed nuclear magnetic resonance (NMR), size exclusion chromatography, attenuated total reflectance Fourier transform infrared (ATR‐IR) in addition to elemental analysis studies of the BiTEMPS polymer confirm the successful polymerization, and show that the BiTEMPS unit remains intact during the polymerization process. Furthermore, the previously unexplored UV‐responsiveness of the BiTEMPS decorated polymer backbone is investigated for the very first time. [ABSTRACT FROM AUTHOR]

A sulfur‐based self‐condensation method is investigated as an efficient tool for the synthesis of polythiophene derivatives. The reaction proceeds through multicomponent redox polycondensation between readily available diketone compounds and elemental sulfur in the presence of a Brønsted acid/base pair. Six different diketone derivatives have been screened and the polymerization is generalized by the synthesis of so‐far‐unprecedented alternating copolymers based on 2,4‐thiophene/arene repeating units. By exploiting microwave heating the synthetic procedure is optimized, particularly for alternating copolymers containing aryl and thiophene units, such that a copolymer can be synthesized in only 24 h compared to the conventional process taking 6 d, yielding polymers within the same apparent weight average molar mass (Mw). All obtained copolymers are analyzed in detail using size exclusion chromatography (SEC), nuclear magnetic resonance (NMR), attenuated total reflectance infrared spectroscopy (ATR‐IR), thermal gravimetric analysis and differential scanning calorimetry (DSC). [ABSTRACT FROM AUTHOR]

A series of poly(sodium methacrylate) hydrogels, also called superabsorbents, having a theoretical degree of neutralization of 100 mol%, and degree of crosslinking varying from 0.6 to 20 mol%, are synthesized via conventional free radical polymerization. The networks are characterized in detail by inverse size‐exclusion chromatography and 1H‐NMR relaxometry in order to place particular emphasis on the investigation of the pore size distribution (PSD) and the chain mobility, respectively. The two previously mentioned parameters are compared to understand the correlation between the elastic chain mobilities and the average pore size of the hydrogel. From the resulting data, a new empirical equation is proposed, which is valid under the given experimental conditions and permits a rough estimation of the average PSD from the relaxation data. Thus, the equation permits to reduce the number of analytical techniques needed for the characterization of complex systems such as polymer networks. [ABSTRACT FROM AUTHOR]

The composition of vascularized adipose tissue is still an ongoing challenge as no culture medium is available to supply adipocytes and endothelial cells appropriately. Endothelial cell medium is typically supplemented with epidermal growth factor (EGF) as well as hydrocortisone (HC). The effect of EGF on adipocytes is discussed controversially. Some studies say it inhibits adipocyte differentiation while others reported of improved adipocyte lipogenesis. HC is known to have lipolytic activities, which might result in mature adipocyte dedifferentiation. In this study, we evaluated the influence of EGF and HC on the co-culture of endothelial cells and mature adipocytes regarding their cell morphology and functionality. We showed in mono-culture that high levels of HC promoted dedifferentiation and proliferation of mature adipocytes, whereas EGF seemed to have no negative influence. Endothelial cells kept their typical cobblestone morphology and showed a proliferation rate comparable to the control independent of EGF and HC concentration. In co-culture, HC promoted dedifferentiation of mature adipocytes, which was shown by a higher glycerol release. EGF had no negative impact on adipocyte morphology. No negative impact on endothelial cell morphology and functionality could be seen with reduced EGF and HC supplementation in co-culture with mature adipocytes. Taken together, our results demonstrate that reduced levels of HC are needed for co-culturing mature adipocytes and endothelial cells. In co-culture, EGF had no influence on mature adipocytes. Therefore, for the composition of vascularized adipose tissue constructs, the media with low levels of HC and high or low levels of EGF can be used. [ABSTRACT FROM AUTHOR]

Perivascular cells are multilineage cells located around the vessel wall and important for wall stabilization. In this study, we evaluated a stem cell media and a perivascular cell-specific media for the culture of primary perivascular cells regarding their cell morphology, doubling time, stem cell properties, and expression of cell type-specific markers. When the two cell culture media were compared to each other, perivascular cells cultured in the stem cell medium had a more elongated morphology and a faster doubling rate and cells cultured in the pericyte medium had a more typical morphology, with several filopodia, and a slower doubling rate. To evaluate stem cell properties, perivascular cells, CD146– cells, and mesenchymal stem cells (MSCs) were differentiated into the adipogenic, osteogenic, and chondrogenic lineages. It was seen that perivascular cells, as well as CD146– cells and MSCs, cultured in stem cell medium showed greater differentiation than cells cultured in pericyte-specific medium. The expression of pericyte-specific markers CD146, neural/glial antigen 2 (NG2), platelet-derived growth factor receptor-β (PDGFR-β), myosin, and α-smooth muscle actin (α-SMA) could be found in both pericyte cultures, as well as to varying amounts in CD146– cells, MSCs, and endothelial cells. The here presented work shows that perivascular cells can adapt to their in vitro environment and cell culture conditions influence cell functionality, such as doubling rate or differentiation behavior. Pericyte-specific markers were shown to be expressed also from cells other than perivascular cells. We can further conclude that CD146+ perivascular cells are inhomogeneous cell population probably containing stem cell subpopulations, which are located perivascular around capillaries. [ABSTRACT FROM AUTHOR]

Background: The aim of this study is to validate the Basic Documentation for Psycho-Oncology Short Form (PO-Bado SF), a six item interview-based expert rating scale for distress screening in cancer patients.Methods: Using a heterogeneous multicenter study sample (n = 1551), we examined validity, reliability, and dimensionality of the PO-Bado SF. The Hospital Anxiety and Depression Scale (HADS), the Distress Thermometer, the Questionnaire on Stress in Cancer, and the Patient Health Questionnaire were used to investigate convergent validity. Confirmatory factor analysis was applied to address unidimensionality. An optimal cutoff point was determined by ROC analysis and the maximum of Youden's index. An additional study with n = 41 audio recorded PO-Bado SF interviews was carried out to assess inter-rater reliability.Results: Mean age of the study sample was 64.0 (SD = 12.0), 42% were women. About 24% of the patients suffered from metastases. The one-factor solution was confirmed; internal consistency of the PO-Bado SF was high (α = 0.84). The PO-Bado SF total score correlated significantly with all psychosocial measures, the highest correlation was with the HADS total score (r = 0.64). Patients with severe disease conditions (metastases, psychological/psychiatric treatment in the past, low performance status) received higher distress ratings (p < 0.001). Using HADS total score (>13) as external criterion, an optimal PO-Bado SF cutoff score of >9 emerged (sensitivity 0.75; specificity 0.82). Inter-rater reliability was satisfactory for each of the six items (intra class correlation of 0.75 to 0.85).Conclusions: The PO-Bado SF is a short, reliable and valid expert rating scale to identify distressed cancer patients. [ABSTRACT FROM AUTHOR]

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Burkholderia cepacia H111, which was isolated from a cystic fibrosis patient, effectively kills the nematode Caenorhabditis elegans. Depending on the medium used for growth of the bacterium two different killing modes were observed. On high-osmolarity medium the nematodes became paralysed and died within 24 h. Using filter assays we provide evidence that this killing mode involves the production of an extracellular toxin. On nematode growth medium killing occurs over the course of 2-3 days and involves the accumulation of bacteria in the intestinal lumen of C. elegans. We demonstrate that the cep quorum-sensing system of H111 is required for efficient killing of C. elegans under both killing conditions. Using the C. elegans phm-2 mutant that has a non-functional grinder evidence is provided that the cep system is required to enter the intestinal lumen but is dispensable for the colonization of the gut. Furthermore, we demonstrate that the type II secretion machinery is not essential for nematode killing. [ABSTRACT FROM AUTHOR]

Summary Burkholderia cepacia and Pseudomonas aeruginosa often co-exist as mixed biofilms in the lungs of patients suffering from cystic fibrosis (CF). Here, we report the isolation of 13 random mini-Tn 5 insertion mutants of B. cepacia H111 that are defective in biofilm formation on a polystyrene surface. We show that the screening procedure used in this study is biased towards mutants defective in the late stages of biofilm development. A detailed quantitative analysis of the biofilm structures formed by wild-type and mutant strains revealed that the isolated mutants are impaired in their abilities to develop a typical three-dimensional biofilm structure. Molecular investigations showed that the genes required for biofilm maturation fall into several classes: (i) genes encoding for surface proteins; (ii) genes involved in the biogenesis and maintenance of an integral outer membrane; and (iii) genes encoding regulatory factors. It is shown that three of the regulatory mutants produce greatly reduced amounts of N -octanoylhomoserine lactone (C8-HSL). This compound serves as the major signal molecule of the cep quorum-sensing system. As this density-dependent regulatory system is involved in the regulation of biofilm maturation, we investigated the interplay between the three regulatory genes and the quorum-sensing cascade. The results of these investigations show that the identified genes encode for regulatory elements that are positioned upstream of the cep system, indicating that the quorum-sensing system of B. cepacia is a major checkpoint for biofilm formation. [ABSTRACT FROM AUTHOR]