225 research outputs found

    En krokodil med vingar - en kvalitativ studie om mellanchefens upplevelse av sin roll i flexibla organisationer

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    Syftet med denna studie Ă€r att skapa en djupare förstĂ„else för hur mellanchefer i flexibla organisationer upplever sin arbetsroll samt hur de arbetar för att möta de krav som stĂ€lls. Studien omfattar mellanchefer i flexibla organisationer, dĂ€r bemanningsföretag har fĂ„tt statuera exempel pĂ„ flexibel organisation. Insamling av empiriskt material har skett via 10 semistrukturerade intervjuer, med totalt 11 intervjupersoner. UtifrĂ„n teorier kring Ă€mnet mellanchefsrollen och hanteringsstrategier har vi analyserat vĂ„r empiri och fĂ„tt en djupare förstĂ„else om hur mellancheferna i flexibla organisationer upplever sin roll och arbetssituation samt hur de hanterar de krav som stĂ€lls pĂ„ dem. Det framgĂ„r i studien att mellancheferna upplever sin arbetsroll som positiv, trots att den stundtals kan vara bĂ„de utmanande och krĂ€vande. Mötet med mĂ€nniskor ses som en central del av rollen och intervjupersonerna beskriver det som en kĂ€lla till sĂ„vĂ€l glĂ€dje som frustration. Stödet frĂ„n sina kollegor och frĂ„n organisationen beskrivs som en förutsĂ€ttning för att klara av sitt arbete. Resultatet visar att mellancheferna anvĂ€nder sig utav bĂ„de problemfokuserade och kĂ€nslofokuserade hanteringsstrategier, vilket frĂ€mst visar sig genom att de anvĂ€nder sig av ett proaktivt förhĂ„llningssĂ€tt för att klara av att möta de krav som stĂ€lls. En metafor för mellanchefens roll i flexibla organisationer kan beskrivas som en krokodil med vingar – de förvĂ€ntas vara överallt i organisationen, lösa alla problem, helst samtidigt och gĂ€rna igĂ„r

    The significance of planning and management of the subsurface to achieve sustainable cities

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    Introduction: The subsurface is the foundation upon which all cities rest. But the subsurface is not only a construction basis which provide physical space for infrastructure and the possibility to create a better surface living environment: the subsurface is a multifunctional natural resource. Apart from physical space, it provides water, energy, materials, habitats for ecosystems, support for surface life, and a repository for cultural heritage and geological archives. Currently, the subsurface is often utilised according to the “first-come-first-served” principle, which hinders possibilities to take strategic decisions on prioritisation and optimisation of competing subsurface uses, as well as fair inter- and intragenerational distribution of limited natural resources. A great disadvantage is the invisibility of the subsurface and consequently a lack of understanding of it as a multifunctional resource: the recently launched concept of geosystem services could help mitigate its underrating. Methods: In order to better acknowledge and lift forward the significance of the subsurface in achieving a sustainable future, the 17 SDGs are scrutinized in relation to the resources of subsurface, and specifically how better planning and management of the subsurface can contribute in achieving the goals. Results: Subsurface planning and management is relevant to at least seven (3, 6, 7, 9, 11, 12, 13) out of seventeen SDGs. Although the subsurface is not explicitly mentioned in the SDGs (except for aquifers), the subsurface can significantly contribute in achieving several of these goals. Conclusions: Sound planning and management of the subsurface can support the achievement of the mapped SDGs in various ways. The subsurface must be recognised as a precious and multifunctional resource which require careful planning and sensitive management in accordance with its potential and its value to society.Grant support: Swedish Research Council Formas (942-2016-50), Swedish Rock Engineering Research Foundation (BeFo 385), Swedish Institute Visby Programme (23887/2017)

    Long-term in vivo integrity and safety of 3D-bioprinted cartilaginous constructs

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    Long-term stability and biological safety are crucial for translation of 3D-bioprinting technology into clinical applications. Here, we addressed the long-term safety and stability issues associated with 3D-bioprinted constructs comprising a cellulose scaffold and human cells (chondrocytes and stem cells) over a period of 10 months in nude mice. Our findings showed that increasing unconfined compression strength over time significantly improved the mechanical stability of the cell-containing constructs relative to cell-free scaffolds. Additionally, the cell-free constructs exhibited a mean compressive stress and stiffness (compressive modulus) of 0.04 +/- 0.05 MPa and 0.14 +/- 0.18 MPa, respectively, whereas these values for the cell-containing constructs were 0.11 +/- 0.08 MPa (p= .019) and 0.53 +/- 0.59 MPa (p= .012), respectively. Moreover, histomorphologic analysis revealed that cartilage formed from the cell-containing constructs harbored an abundance of proliferating chondrocytes in clusters, and after 10 months, resembled native cartilage. Furthermore, extension of the experiment over the complete lifecycle of the animal model revealed no signs of ossification, fibrosis, necrosis, or implant-related tumor development in the 3D-bioprinted constructs. These findings confirm the in vivo biological safety and mechanical stability of 3D-bioprinted cartilaginous tissues and support their potential translation into clinical applications

    Subsurface planning: Towards a common understanding of the subsurface as a multifunctional resource

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    In response to powerful trends in technology, resource and land supply and demand, socioeconomics and geopolitics, cities are likely to increase use of the subsurface in the near future. Indeed, the subsurface and its appropriate use have been put forward as being of crucial importance if we are to achieve resilient and sustainable cities. In recent years, quite apart from being seen primarily as a construction basis to provide physical space for infrastructure and to create a better surface living environment, the subsurface has been recognised as a multifunctional natural resource, one which provides physical space, water, energy, materials, habitats for ecosystems, support for surface life, and a repository for cultural heritage and geological archives. Currently, the subsurface is often utilised according to the “first-come-first-served” principle, which hinders possibilities to take strategic decisions on prioritisation and optimisation of competing subsurface uses, as well as fair inter- and intragenerational distribution of limited natural resources. Taking a broad international perspective, this paper investigates the subsurface as a multifunctional resource from five focal points: (1) what professionals with different backgrounds mean when using different terms related to the subsurface; (2) how professionals describe the subsurface and its multiple resources, functions and services; (3) how planning of subsurface use is supported in policy and regulations; (4) how the subsurface is included in the planning process; and (5) frameworks that can support decision-making on responsible use of the subsurface. The study reveals that the subsurface must be recognised (not only by scientists but also by decision- and policy-makers and other stakeholders) as a precious and multifunctional resource requiring careful planning and sensitive management in accordance with its potential and its value to society. Utilisation of the different subsurface functions to yield services requires careful planning and a framework to support decision-makers in achieving a balance between utilisation and preservation, and between the subsurface functions themselves in the case of outright utilisation. Further, to facilitate the necessary change towards transdisciplinary work settings in the planning process and form a platform for knowledge exchange and capacity building, there is an urgent need for a common language, i.e. mutually understandable terminology, and a common understanding, i.e. an all-inclusive view on the subsurface as a complex multifunctional resource

    Simulations of 3D bioprinting: predicting bioprintability of nanofibrillar inks

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    3D bioprinting with cell containing bioinks show great promise in the biofabrication of patient specific tissue constructs. To fulfil the multiple requirements of a bioink, a wide range of materials and bioink composition are being developed and evaluated with regard to cell viability, mechanical performance and printability. It is essential that the printability and printing fidelity is not neglected since failure in printing the targeted architecture may be catastrophic for the survival of the cells and consequently the function of the printed tissue. However, experimental evaluation of bioinks printability is time-consuming and must be kept at a minimum, especially when 3D bioprinting with cells that are valuable and costly. This paper demonstrates how experimental evaluation could be complemented with computer based simulations to evaluate newly developed bioinks. Here, a computational fluid dynamics simulation tool was used to study the influence of different printing parameters and evaluate the predictability of the printing process. Based on data from oscillation frequency measurements of the evaluated bioinks, a full stress rheology model was used, where the viscoelastic behaviour of the material was captured. Simulation of the 3D bioprinting process is a powerful tool and will help in reducing the time and cost in the development and evaluation of bioinks. Moreover, it gives the opportunity to isolate parameters such as printing speed, nozzle height, flow rate and printing path to study their influence on the printing fidelity and the viscoelastic stresses within the bioink. The ability to study these features more extensively by simulating the printing process will result in a better understanding of what influences the viability of cells in 3D bioprinted tissue constructs

    3D printing is a transformative technology in congenital heart disease

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    Survival in congenital heart disease has steadily improved since 1938, when Dr. Robert Gross successfully ligated for the first time a patent ductus arteriosus in a 7-year-old child. To continue the gains made over the past 80 years, transformative changes with broad impact are needed in management of congenital heart disease. Three-dimensional printing is an emerging technology that is fundamentally affecting patient care, research, trainee education, and interactions among medical teams, patients, and caregivers. This paper first reviews key clinical cases where the technology has affected patient care. It then discusses 3-dimensional printing in trainee education. Thereafter, the role of this technology in communication with multidisciplinary teams, patients, and caregivers is described. Finally, the paper reviews translational technologies on the horizon that promise to take this nascent field even further

    Three dimensional ink-jet printing of biomaterials using ionic liquids and co-solvents

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    1-Ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) and 1-butyl-3-methylimidazolium acetate ([C4C1Im][OAc]) have been used as solvents for the dissolution and ink-jet printing of cellulose from 1.0 to 4.8 wt%, mixed with the co-solvents 1-butanol and DMSO. 1-Butanol and DMSO were used as rheological modifiers to ensure consistent printing, with DMSO in the range of 41–47 wt% producing samples within the printable range of a DIMATIX print-head used (printability parameter < 10) at 55 °C, whilst maintaining cellulose solubility. Regeneration of cellulose from printed samples using water was demonstrated, with the resulting structural changes to the cellulose sample assessed by scanning electron microscopy (SEM) and white light interferometry (WLI). These results indicate the potential of biorenewable materials to be used in the 3D additive manufacture process to generate single-component and composite materials

    Conductive Cellulose Composites with Low Percolation Threshold for 3D Printed Electronics

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    We are reporting a 3D printable composite paste having strong thixotropic rheology. The composite has been designed and investigated with highly conductive silver nanowires. The optimized electrical percolation threshold from both simulation and experiment is shown from 0.7&thinsp;vol. % of silver nanowires which is significantly lower than other composites using conductive nano-materials. Reliable conductivity of 1.19&thinsp;×&thinsp;102&thinsp;S/cm has been achieved from the demonstrated 3D printable composite with 1.9&thinsp;vol. % loading of silver nanowires. Utilizing the high conductivity of the printable composites, 3D printing of designed battery electrode pastes is demonstrated. Rheology study shows superior printability of the electrode pastes aided by the cellulose\u27s strong thixotropic rheology. The designed anode, electrolyte, and cathode pastes are sequentially printed to form a three-layered lithium battery for the demonstration of a charging profile. This study opens opportunities of 3D printable conductive materials to create printed electronics with the next generation additive manufacturing process

    Nanocellulose/bioactive glass cryogels as scaffolds for bone regeneration

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    A major challenge exists in the preparation of scaffolds for bone regeneration, namely, achieving simultaneously bioactivity, biocompatibility, mechanical performance and simple manufacturing. Here, cellulose nanofibrils (CNF) are introduced for the preparation of scaffolds taking advantage of their biocompatibility and ability to form strong 3D porous networks from aqueous suspensions. CNF are made bioactive for bone formation through a simple and scalable strategy that achieves highly interconnected 3D networks. The resultant materials optimally combine morphological and mechanical features and facilitate hydroxyapatite formation while releasing essential ions for in vivo bone repair. The porosity and roughness of the scaffolds favor several cell functions while the ions act in the expression of genes associated with cell differentiation. Ion release is found critical to enhance the production of the bone morphogenetic protein 2 (BMP-2) from cells within the fractured area, thus accelerating the in vivo bone repair. Systemic biocompatibility indicates no negative effects on vital organs such as the liver and kidneys. The results pave the way towards a facile preparation of advanced, high performance CNF-based scaffolds for bone tissue engineering

    Multicomponent polysaccharide alginate-based bioinks

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    3D-Bioprinting has seen a rapid expansion in the last few years, with an increasing number of reported bioinks. Alginate is a natural biopolymer that forms hydrogels by ionic cross-linking with calcium ions. Due to its biocompatibility and ease of gelation, it is an ideal ingredient for bioinks. This review focuses on recent advances on bioink formulations based on the combination of alginate with other polysaccharides. In particular, the molecular weight of the alginate and its loading level has an impact on materials performance, as well as the loading of the divalent metal salt and its solubility, which affects the cross-linking of the gel. Alginate is often combined with other polysaccharides that can sigificantly modify the properties of the gel, and can optimise alginate for use in different biological applications. It is also possible to combine alginate with sacrificial polymers, which can temporarily reinforce the 3D printed construct, but then be removed at a later stage. Other additives can be formulated into the gels to enhance performance, including nanomaterials that tune rheological properties, peptides to encourage cell adhesion, or growth factors to direct stem cell differentiation. The ease of formulating multiple components into alginate gels gives them considerable potential for further development. In summary, this review will facilitate the identification of different alginate-polysaccharide bioink formulations and their optimal applications, and help inform the design of second generation bioinks, allowing this relatively simple gel system to achieve more sophisticated control over biological processes
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