In vitro vascularization of hydrogel-based tissue constructs via a combined approach of cell sheet engineering and dynamic perfusion cell culture

The bioengineering of artificial tissue constructs requires special attention to their fast vascularization to provide cells with sufficient nutrients and oxygen. We addressed the challenge of in vitro vascularization by employing a combined approach of cell sheet engineering, 3D printing, and cellular self-organization in dynamic maturation culture. A confluent cell sheet of human umbilical vein endothelial cells (HUVECs) was detached from a thermoresponsive cell culture substrate and transferred onto a 3D-printed, perfusable tubular scaffold using a custom-made cell sheet rolling device. Under indirect co-culture conditions with human dermal fibroblasts (HDFs), the cell sheet-covered vessel mimic embedded in a collagen gel together with additional singularized HUVECs started sprouting into the surrounding gel, while the suspended cells around the tube self-organized and formed a dense lumen-containing 3D vascular network throughout the gel. The HDFs cultured below the HUVEC-containing cell culture insert provided angiogenic support to the HUVECs via molecular crosstalk without competing for space with the HUVECs or inducing rapid collagen matrix remodeling. The resulting vascular network remained viable under these conditions throughout the 3 week cell culture period. This static indirect co-culture setup was further transferred to dynamic flow conditions, where the medium perfusion was enabled via two independently addressable perfusion circuits equipped with two different cell culture chambers, one hosting the HDFs and the other hosting the HUVEC-laden collagen gel. Using this system, we successfully connected the collagen-embedded HUVEC culture to a dynamic medium flow, and within 1 week of the dynamic cell culture, we detected angiogenic sprouting and dense microvascular network formation via HUVEC self-organization in the hydrogel. Our approach of combining a 3D-printed and cell sheet-covered vascular precursor that retained its sprouting capacity together with the self-assembling HUVECs in a dynamic perfusion culture resulted in a vascular-like 3D network, which is a critical step toward the long-term vascularization of bioengineered in vitro tissue constructs

Developing Scheme and 802.11 Mesh Networks

Unified pervasive modalities have led to many private advances, including kernels and local-area networks. In fact, few systems engineers would disagree with the simulation of SCSI disks, demonstrates the significant importance of distributed systems. Our focus in this position paper is not on whether the seminal virtual algorithm for the simulation of compilers by V. A. Jackson et al. is NP-complete, but rather on motivating a novel heuristic for the study of IPv4 (Boomdas)

Flow-induced glycocalyx formation and cell alignment of HUVECs compared to iPSC-derived ECs for tissue engineering applications

The relevance of cellular in vitro models highly depends on their ability to mimic the physiological environment of the respective tissue or cell niche. Static culture conditions are often unsuitable, especially for endothelial models, since they completely neglect the physiological surface shear stress and corresponding reactions of endothelial cells (ECs) such as alignment in the direction of flow. Furthermore, formation and maturation of the glycocalyx, the essential polysaccharide layer covering all endothelial surfaces and regulating diverse processes, is highly dependent on applied fluid flow. This fragile but utterly important macromolecular layer is hard to analyze, its importance is often underestimated and accordingly neglected in many endothelial models. Therefore, we exposed human umbilical vein ECs (HUVECs) and human induced pluripotent stem cell-derived ECs (iPSC-ECs) as two relevant EC models in a side-by-side comparison to static and physiological dynamic (6.6 dyn cm−2) culture conditions. Both cell types demonstrated an elongation and alignment along the flow direction, some distinct changes in glycocalyx composition on the surface regarding the main glycosaminoglycan components heparan sulfate, chondroitin sulfate or hyaluronic acid as well as an increased and thereby improved glycocalyx thickness and functionality when cultured under homogeneous fluid flow. Thus, we were able to demonstrate the maturity of the employed iPSC-EC model regarding its ability to sense fluid flow along with the general importance of physiological shear stress for glycocalyx formation. Additionally, we investigated EC monolayer integrity with and without application of surface shear stress, revealing a comparable existence of tight junctions for all conditions and a reorganization of the cytoskeleton upon dynamic culture leading to an increased formation of focal adhesions. We then fabricated cell sheets of EC monolayers after static and dynamic culture via non-enzymatic detachment using thermoresponsive polymer coatings as culture substrates. In a first proof-of-concept we were able to transfer an aligned iPSC-EC sheet to a 3D-printed scaffold thereby making a step in the direction of vascular modelling. We envision these results to be a valuable contribution to improvements of in vitro endothelial models and vascular engineering in the future

Symptoms of post-traumatic stress disorder among first aid providers

Background Every year, large numbers of individuals are present or provide first aid in situations involving out-of-hospital cardiac arrest, injuries, or suicides. Little is known about the impact of providing first aid or witnessing a first aid situation, but research indicates that many first aid providers (FAP) experience persistent psychological difficulties. Here we aimed to assess the level of psychological impact of being a FAP. Methods In this retrospective study, FAP attending follow-up were asked to complete the International Trauma Questionnaire (ITQ), which is a self-report diagnostic measure of post-traumatic stress disorder (PTSD) and complex post-traumatic stress disorder (CPTSD). We recorded endorsement of a symptom or functional impairment (score ≥ 2/4 on at least one of 18 items). Results Of the 102 FAP in this study, 86 (84%) showed endorsement of a symptom or functional impairment. Common symptoms/functional impairments included being super-alert, watchful, or on guard; having powerful mental images; avoiding internal reminders or memories; and being affected in important parts of one’s life. One-third had affected ability to work. Of the FAPs who attended follow-up more than one month after the incident (n = 32), 19% met the criteria for PTSD or CPTSD. Conclusions The majority of FAPs have endorsement of a symptom or functional impairment. Some FAPs fulfil the criteria of PTSD. We suggest that follow-up should be offered by the EMS to all FAPs involved in incidents with an unconscious patient.publishedVersio

Are assessments responding to a dynamic environment? Evidence from four emerging techno-scientific domains

Assessments of emerging science and technologies can assist actors to anticipate and influence techno-scientific development. Although the importance of contextual factors in techno-scientific development has been stressed, the extent to which economic, societal and political trends are integrated into assessment practices is unknown. Focusing on a number of such trends, this paper shows that there are clear differences in how trends are being addressed in different techno-scientific domains. Maturity, developmental speed and societal awareness of techno-scientific domains, as well as associated impacts thereof, seem to influence the consideration of trends in assessments. Furthermore, both the extent and quality of trend reflection seem to be related to the methodological approaches applied in conducting assessments, including the use of participatory approaches, temporal orientations and the transparency of assessment processes in general

Voluntary Wheel Running in Old C57BL/6 Mice Reduces Age-Related Inflammation in the Colon but Not in the Brain

Inflammation is considered a possible cause of cognitive decline during aging. This study investigates the influence of physical activity and social isolation in old mice on their cognitive functions and inflammation. The Barnes maze task was performed to assess spatial learning and memory in 3, 9, 15, 24, and 28 months old male C57BL/6 mice as well as following voluntary wheel running (VWR) and social isolation (SI) in 20 months old mice. Inflammatory gene expression was analyzed in hippocampal and colonic samples by qPCR. Cognitive decline occurs in mice between 15 and 24 months of age. VWR improved cognitive functions while SI had negative effects. Expression of inflammatory markers changed during aging in the hippocampus ( Il1a / Il6 / S100b / Iba1 / Adgre1 / Cd68 / Itgam ) and colon ( Tnf / Il6 / Il1ra / P2rx7 ). VWR attenuates inflammaging specifically in the colon ( Ifng / Il10 / Ccl2 / S100b / Iba1 ), while SI regulates intestinal Il1b and Gfap . Inflammatory markers in the hippocampus were not altered following VWR and SI. The main finding of our study is that both the hippocampus and colon exhibit an increase in inflammatory markers during aging, and that voluntary wheel running in old age exclusively attenuates intestinal inflammation. Based on the existence of the gut-brain axis, our results extend therapeutic approaches preserving cognitive functions in the elderly to the colon

USE OF THE FLIGHT TEST FACILITY MOCK-UPS IN THE EUROPEAN CLEAN SKY 2 PROGRAM

The Clean Sky 2 program unites all major European players in the aeronautical sector to conduct research on future, more energy efficient aircrafts with lower environmental footprint. Besides technologies developments, the demonstration of technologies in dedicated test environments is a key element of this research program. The Fraunhofer Flight Test Facility is such a platform for technology demonstration. Located in Holzkirchen, south of Munich, it hosts several aircraft fuselage structures and allows for indoor environmental tests under realistic temperature, moisture and pressure conditions. In this paper, demonstrations performed within Clean Sky 2 are highlighted. These include an adaptive ECS system, environmentally friendly fire protection, model validation tests for ETOPS considerations and cleaning and disinfection demonstrations

Patients\u27 Willingness to Accept Social Needs Navigation After In-Person Versus Remote Screening

Social needs screening and referral interventions are increasingly common in health care settings. Although remote screening offers a potentially more practical alternative to traditional in-person screening, there is concern that screening patients remotely could adversely affect patient engagement, including interest in accepting social needs navigation

Aneuploidy screening of embryonic stem cell clones by metaphase karyotyping and droplet digital polymerase chain reaction

DNA input in ddPCR reaction. The figure shows copy number of Chr 8 (crosses) and Y (squares) measured by ddPCR with various input quantities of genomic DNA template. Vertical bars are Standard Errors. The experiment demonstrates linearity across the range of concentrations relevant to the DNA preparations assayed. This is a key point for the robustness of the screen, as gDNA preparations are challenging to standardize due to the disparity of growth rates between ES cell clones. (PDF 26 kb

Joint declaration on mainstreaming RRI across Horizon Europe

Leading RRI researchers and practitioners, together with policymakers and stakeholder organisations, discussed the state-of-the-art and future perspectives for RRI at the ‘Pathways to Transformation’ conference in June 2019, an event which was extended beyond Brussels, for instance by ca. 330 original tweets and ca. 840 retweets from ca. 160 unique accounts. In the conference, many participants expressed their concern about an uncertain future for RRI in the EC. As a result, numerous large-scale EU-funded RRI projects signed a Joint Declaration, urging the European Commission to make RRI a key objective of the upcoming framework programme, Horizon Europe – a plea to both mainstream the approach across the programme and provide specific resources for strengthening the RRI knowledge base. As the Horizon Europe programme is being forged, it is timely to present the Declaration for a broader audience