Self-assembling Fmoc dipeptide hydrogel for in situ 3D cell culturing

<p>Abstract</p> <p>Background</p> <p>Conventional cell culture studies have been performed on 2D surfaces, resulting in flat, extended cell growth. More relevant studies are desired to better mimic 3D <it>in vivo </it>tissue growth. Such realistic environments should be the aim of any cell growth study, requiring new methods for culturing cells <it>in vitro</it>. Cell biology is also tending toward miniaturization for increased efficiency and specificity. This paper discusses the application of a self-assembling peptide-derived hydrogel for use as a 3D cell culture scaffold at the microscale.</p> <p>Results</p> <p>Phenylalanine derivative hydrogel formation was seen to occur in multiple dispersion media. Cells were immobilized <it>in situ </it>within microchambers designed for cell analysis. Use of the highly biocompatible hydrogel components and simplistic procedures significantly reduced the cytotoxic effects seen with alternate 3D culture materials and microstructure loading methods. Cells were easily immobilized, sustained and removed from microchambers. Differences in growth morphology were seen in the cultured cells, owing to the 3-dimentional character of the gel structure. Degradation improved the removal of hydrogel from the microstructures, permitting reuse of the analysis platforms.</p> <p>Conclusion</p> <p>Self-assembling diphenylalanine derivative hydrogel provided a method to dramatically reduce the typical difficulties of microculture formation. Effective generation of patterned 3D cultures will lead to improved cell study results by better modeling <it>in vivo </it>growth environments and increasing efficiency and specificity of cell studies. Use of simplified growth scaffolds such as peptide-derived hydrogel should be seen as highly advantageous and will likely become more commonplace in cell culture methodology.</p

Исследование функциональных характеристик композиционных материалов антифрикционного назначения на основе полиамида

Материалы XIV Междунар. науч.-техн. конф. студентов, аспирантов и молодых ученых, Гомель, 24–25 апр. 2014 г

The nurses´ coping strategies for handling emotional stress

I sitt dagliga arbete möter sjuksköterskan ständigt olika former av lidande, sorg och människor som befinner sig i svåra situationer. Sjuksköterskan utsätts för stress och olika typer av emotionell påfrestning. Forskning visar att emotionell överbelastning kan leda till att sjuksköterskan utvecklar en känslokall distans till patienten. Det är en balansgång för sjuksköterskan att vara personlig men inte privat i mötet med patienten. För att vården ska bedrivas på ett engagerat och empatiskt sätt bör det finnas ett känslomässigt engagemang, men ändå med en professionell distans från sjuksköterskan sida, för att hon inte ska riskera att bli emotionellt utmattad. Syftet med denna litteraturstudie var att underöka vilka copingstrategier sjuksköterskor använder sig av för att hantera den emotionella stress de utsätts för i sitt dagliga arbete. Copingstrategier inom palliativ, onkologisk och intensivvård har undersökts. Resultatet visar att sjuksköterskor använder sig av en rad olika copingstrategier. De mest centrala är positiv omvärdering av situationen, problemlösning, att söka socialt stöd, och självkontroll. Accepterande av ansvar tillhör de copingstrategier som används minst

Asymmetric Cellular Microenvironments

This thesis presents methods to combine 3D cell culture, microfluidics and gradients on a controlled cellular scale. 3D cultures in biological extracellular matrix gels or synthetic gels bridge the gap between organ-tissue cultures and traditional 2D cultures. A device for embedding, anchoring and culturing cells in a controlled 3D flow through micro-environment was designed and evaluated. The device was realized using an etched silicon pillar flow chamber filled with gel mixed with cells. The pillars anchor and stabilize the gel as well as increase the surface to volume ratio, permitting higher surface flow rates and improving diffusion properties. Within the structure cells were still viable and proliferating after six days of cultivation, showing that it is possible to perform medium- to-long term cultivation of cells in a controlled 3D environment. This concept was further developed to include controllable and time stable 3D microgradient environments. In this system stable diffusion gradients can be generated by the application of two parallel fluid flows with different composition against opposite sides of a gel plug with embedded cells. Culture for up to two weeks was performed showing cells still viable and proliferating. The cell tracer dye calcein was used to verify gradient formation as the fluorescent intensity in exposed cells was proportional to the position in the chamber. Cellular response to an applied stimulus was demonstrated by use of an adenosine triphosphate gradient where the onset of an intracellular calcium release also depends on cell position.QC 2010111

Thomas Frisk 1

Cells in tissues are organized in well-defined 3-D structures. However, most cell physiological studies are still performed on 2-D cell cultures or on single dissociated cells, environments that are far from representative for th

Information system database refactoring

Bakalaura darbā tika aprakstīti ieteikumi kā, izmantojot restrukturizācijas metodes, uzlabot datu bāzes veiktspēju. Autors ir aplūkojis restrukturizācijas procesa galvenās vadlīnijas, tamdēļ darbs ir vērtīgs gan programmatūras koda izstrādātajiem, gan relāciju datu bāzes speciālistiem. Darbs satur vairākus konkrētus praktiskus ieteikumus datu bāzes projektējuma un informācijas sistēmas ātrdarbības uzlabošanai. Bakalaura darbā tika aplūkotas testēšanas metodes, kas nodrošina restrukturizācijas operāciju kvalitāti. Primāri darbs var kalpot projekta izstrādātājam kā tehniskā rokasgrāmata, bet tā kā darbs satur arī teorētisko daļu, tad tas var noderēt par stimulu dziļākiem pētījumiem restrukturizācijas jomā.This bachelor thesis describes refactoring methods to improve database performance. Author described baselines or refactoring processes, therefore the bachelor thesis is useful for developers and relation data base professionals. Bachelor thesis contains number of practical recommendations for information system performance improvement and data base design. The bachelor thesis describes test methods for quality assurance after refactoring operations. Primarly thesis is a technical manual for system developers, but it contains theoretical part, which may stimulate in-depth research of refactoring

MICROFLUIDIC DEVICE FOR STUDIES OF PRIMARY CILIUM DIRECTION SENSITIVITY

ABSTRACT This paper presents a novel method for studying cilia forming cells in asymmetric microfluidic environments. It has previously been shown that bending the primary cilium by a fluid flow will give rise to a calcium signal, but the sensitivity for flow direction has so far not been studied. The microfluidic device presented here was designed for control of the local direction of fluid flow on the cellular level, and thus, enables studies of cellular response to a direction controlled cilium movement. Cells seeded on cover slips form cilia with the average length 2.9 µm after three days in culture and 4.3 µm after four days. Distinct calcium peaks were found after the initiation of flow in the channel. By using a microstructured flow system we have been able to study the sensitivity of confluent COS 7 cells expressing primary cilium to changes in fluid flow

Three dimensional asymmetric microenvironment for cell biological studies

We report on a method for three-dimensional cultivation of cells in a microstructured asymmetric environment. In the system an asymmetric environment is created by using diffusion through a gel of extra cellular matrix proteins surrounded by microfluidic flow channels. Individual cells embedded in the gel react on the concentration gradient. The system has been evaluated both for diffusion properties and based on the cellular response.NQ

Three dimensional asymmetric microenvironment for cell biological studies

We report on a method for three-dimensional cultivation of cells in a microstructured asymmetric environment. In the system an asymmetric environment is created by using diffusion through a gel of extra cellular matrix proteins surrounded by microfluidic flow channels. Individual cells embedded in the gel react on the concentration gradient. The system has been evaluated both for diffusion properties and based on the cellular response.NQ

Microfluidic device for studies of primary cilium direction sensitivity

This paper presents a novel method for studying cilia forming cells in asymmetric microfluidic environments. It has previously been shown that bending the primary cilium by a fluid flow will give rise to a calcium signal, but the sensitivity for flow direction has so far not been studied. The microfluidic device presented here was designed for control of the local direction of fluid flow on the cellular level, and thus, enables studies of cellular response to a direction controlled cilium movement. Cells seeded on cover slips form cilia with the average length 2.9 μm after three days in culture and 4.3 μm after four days. Distinct calcium peaks were found after the initiation of flow in the channel. By using a microstructured flow system we have been able to study the sensitivity of confluent COS 7 cells expressing primary cilium to changes in fluid flow.NQ