Search results for "mixture"
showing 10 items of 1178 documents
The use of hydrogels in bone-tissue engineering
2010
Many different types of scaffold materials have been used for tissue engineering applications, and hydrogels form one group of materials that have been used in a wide variety of applications. Hydrogels are hydrophilic polymer networks and they represent an important class of biomaterials in biotechnology and medicine because many hydrogels exhibit excellent biocompatibility with minimal inflammatory responses and tissue damage. Many studies have demonstrated the use of hydrogels in bone-tissue engineering applications. In this report, the summary was conducted on various kinds of polymers and different modification methods of hydrogels to enhance bone formation. The results revealed that hy…
Development of a morphogenetically active scaffold for three-dimensional growth of bone cells: biosilica-alginate hydrogel for SaOS-2 cell cultivation
2013
Polymeric silica is formed from ortho-silicate during a sol–gel formation process, while biosilica is the product of an enzymatically driven bio-polycondensation reaction. Both polymers have recently been described as a template that induces an increased expression of the genes encoding bone morphogenetic protein 2 (BMP-2) and osteoprotegerin in osteoblast-related SaOS-2 cells; simultaneously or subsequently the cells respond with enhanced hydroxyapatite formation. In order to assess whether the biocompatible polymeric silica/biosilica can serve as a morphogenetically active matrix suitable for three-dimensional (3D) cell growth, or even for 3D cell bioprinting, SaOS-2 cells were embedded i…
Response of micro- and macrovascular endothelial cells to starch-based fiber meshes for bone tissue engineering.
2006
The establishment of a functional vasculature is as yet an unrealized milestone in bone reconstruction therapy. For this study, fiber-mesh scaffolds obtained from a blend of starch and poly(caprolactone) (SPCL), that have previously been shown to be an excellent material for the proliferation and differentiation of bone marrow cells and thereby represent great potential as constructs for bone regeneration, were examined for endothelial cell (EC) compatibility. To be successfully applied in vivo, this tissue engineered construct should also be able to support the growth of ECs in order to facilitate vascularization and therefore assure the viability of the construct upon implantation. The ma…
Organic coating on biochar explains its nutrient retention and stimulation of soil fertility
2017
Amending soil with biochar (pyrolized biomass) is suggested as a globally applicable approach to address climate change and soil degradation by carbon sequestration, reducing soil-borne greenhouse-gas emissions and increasing soil nutrient retention. Biochar was shown to promote plant growth, especially when combined with nutrient-rich organic matter, e.g., co-composted biochar. Plant growth promotion was explained by slow release of nutrients, although a mechanistic understanding of nutrient storage in biochar is missing. Here we identify a complex, nutrient-rich organic coating on co-composted biochar that covers the outer and inner (pore) surfaces of biochar particles using high-resoluti…
Developmental trajectories of school burnout: Evidence from two longitudinal studies
2014
Abstract To examine school burnout trajectories, in Study 1, 15-year-old adolescents ( N = 614) completed the School Burnout Inventory twice during their final term of comprehensive school and twice after the transition to upper secondary high school or vocational school. In Study 2, school burnout in 17-year-old adolescents was measured twice annually ( N = 575) during their upper secondary education. In Study 1, growth mixture modeling for school burnout yielded a four-latent-group solution: 60% of the adolescents showed a low and stable level of school burnout, 29% increasing burnout, 3% strongly increasing burnout and 8% high-decreasing school burnout. In Study 2, we identified two la…
Career goal-related success expectations across two educational transitions: A seven-year longitudinal study
2013
The purpose of this seven-year longitudinal study was to examine the trajectories of adolescents' career goal-related success expectations during two educational transitions. Altogether 850 (48% female, M Age = 16) participants reported their success expectations for their career-related goals, first in the last year of comprehensive school and four times during the following seven years. Overall, the success expectations showed a significant increase. However, there was considerable heterogeneity in the development of these expectations. Growth Mixture Modeling showed that four trajectories fitted the data best: high-increasing (78%), low-increasing (9%), decreasing (6%) and U-shaped (7%).…
Hsp60 and human aging: Les liaisons dangereuses
2013
Stressors can cause abnormal intracellular accumulation of Hsp60 and its localization in extramitochondrial sites, secretion, and circulation, with immune system activation. Dysfunction of chaperones associated with their quantitative and qualitative decline with aging (chaperonopathies of aging) characterizes senescence and is a potential causal factor in the physiological deterioration that occurs with it. The role of Hsp60 in aging is not easy to elucidate, because aging is accompanied by pathologies (e.g., cardiovascular and neurodegenerative disorders, osteoporosis, diabetes, cancer, etc.) in which Hsp60 has been implicated but, although those disorders are more frequent in the elderly…
Novel bioactive bromopyrrole alkaloids from the Mediterranean sponge Axinella verrucosa
2005
The Mediterranean sponge Axinella verrucosa has been investigated for its alkaloid composition and has been found to produce a complex mixture of bromopyrrole alkaloids. Along with the previously isolated compounds 5-18, four novel alkaloids of this class, compounds 1-4, have been isolated, and their structures established through spectroscopic methods. Compounds 1-4 were found to display neuroprotective activity against the agonists serotonin and glutamate in vitro.
Immune response to the 23-valent polysaccharide pneumococcal vaccine after the 7-valent conjugate vaccine in allogeneic stem cell transplant recipien…
2009
The current recommendations for active immunization after stem cell transplant (SCT) include 3 doses of 7-valent pneumococcal conjugate vaccine (PCV7) from 3 months after transplant, followed by a 23-valent polysaccharide pneumococcal vaccine (PPV23). However, until now, the immune response to PPV23 after PCV7 has not been assessed after SCT. In the EBMT IDWP01 trial, 101 patients received 1 dose of PPV23 at 12 or 18 months, both after 3 doses of PCV7. The efficacy of PPV23 was assessed 1 month later and at 24 months after transplant by the pneumococcal serotype 1 and 5 antibody levels. Serotype 1 and 5 are not included in PCV7. Although the geometric mean concentrations were significantly …
Safety, tolerability, and immunologic noninferiority of a 13-valent pneumococcal conjugate vaccine compared to a 7-valent pneumococcal conjugate vacc…
2010
13-valent pneumococcal conjugate vaccine (PCV13) was compared to PCV7 in infants administered 4 doses. For the 7 common serotypes, PCV13- and PCV7-elicited responses showed comparable percent responders achieving 0.35mug/mL IgG threshold (exception 6B, 77.5% versus 87.1%, respectively) and OPA titers of 1:8; IgGs were lower than PCV7 but functional responses were generally comparable. For the 6 additional serotypes, PCV13-elicited IgG and functional OPA responses were notably greater than PCV7. The toddler dose boosted immune responses. Vaccines were comparable with regard to safety. PCV13 should be as effective as PCV7 in preventing pneumococcal disease caused by the common serotypes and m…