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689 Uppsatser om Cell cycle - Sida 1 av 46

The role of cell cycle control mechanisms in regulated and sustained cell proliferation

The Cell cycle is the time a cell spends between two cell divisions. The Cell cycle includes several parallel processes, all of which must be completed before a cell is mature for dividing. In the first place, all subcomponents (RNA, protein and membrane lipids) need to double in quantity and this occurs continuously through the Cell cycle. Furthermore, the genome and some chromosomal proteins must double and this take place during a limited interval in the middle of the Cell cycle (S-phase). On either side of the S-phase are two "gaps" which is called G1 and G2. When the cell has passed a point in the G-phase they are irreversibly programmed to progress through the remaining of the Cell cycle and will undergo the next cell division. When a cell have passed a point in the G1 phase, approximately four hours after mitosis, a normal cell is in a state of indecision.

The control of the cell cycle with particular emphasis on the G1/S transition

Tumour development occurs to a large extent because of dysregulation of the Cell cycle. Of particular importance are defects occurring in the G1 phase. The reason why G1 is critical is because of the influence of several signals (external signals as well as cyclins and cdks) on this stage. The G1 phase can be divided into two parts, G1pm and G1ps. Each part has its ?own? restriction point which needs to be passed in order to progress to S phase.

Thymidinkinas 1 som tumörmarkör vid juvertumörer hos tik :

Determination of serum thymidine kinase 1 (TK-1) activity is used as a tumour marker in both human and veterinary medicine. TK-1 is an intracellular enzyme involved in a salvage pathway of DNA synthesis. The expression of TK-1 is cell cycle dependent and the activity increases markedly after the G1 to S transition in the Cell cycle and then declines rapidly in G2. The pronounced proliferative activity in tumour cells result in a higher TK-1 enzyme activity within the cell. The fact that the increased TK-1 activity can be measured in serum makes TK-1 a useful marker in diagnostics of neoplastic diseases and it provides information regarding prognosis and treatment effectiveness. In human medicine a radioactive based test is used to determine the TK-1 serum activity.

Basmobilen

Today?s cell phones include more and more functionality, it is no longer uncommon to be able to connect to the Internet or take photos with the cell phone. In this thesis the question is if the cell phone users are interested in this new functionality. Are there people who are interested in a cell phone that in this thesis is called ?Basmobilen? (the entry level phone), which include the following functions; phone call, SMS, phone book, calling lists, clock and the possibility to change the call signal.

Mastcellens funktion vid försvar mot infektioner

The complexity of the mast cell is becoming more prominent. From being the cell recognized just to contribute to allergic inflammation it is now also associated with wound healing, protection against tumor growth and in recognition and defense against a wide range of pathogens. The location of the mast cell in the barrier between the external and internal environment of the body enables the cell to quickly respond to invading bacteria, virus and parasites. Diarrhea due to Escherichia coli infection, listeriosis, toxoplasmosis, Newcastle disease and bovine respiratory syncytial virus are examples of mast cell activating diseases that can affect animals in, as well as outside, the agricultural sector. Additionally, ticks and tick-borne diseases are of concern.

3D modelling of a Laser Welding Cell for movie presentation : making of the movie

This report describes a Bachelor thesis work in which a robotised laser welding cell has been modelled and simulated for the purpose of making a presentation movie. The report shows that the work has been concentrated on making the movie from the modelling phase through the recording of the movie and ending up with the editing of the final presentation movie. A pre-study was made prior the Bachelor thesis work. In the pre-study a literature study was conducted about measurement and calibration of a welding cell. Measurement of almost all equipment in the entire cell was also conducted in the pre-study.

The significance of oxytocin in canine mammary tumours

Oxytocin is a hormone which plays a crucial role in many reproductive and behavioural functions. It affects many organs and the classical peripheral targets are the mammary glands during lactation and uterus during labour. Oxytocin receptors have recently been described in a variety of normal tissues and primary cell cultures, but also in neoplastic tissues and established neoplastic cell lines, as breast cancer cell lines. The signalling pathways and biological effects of the oxytocin/oxytocin receptor system seem to depend on species, type of tissue, physiological versus neoplastic state and receptor location within the cell membrane.The aim of this project was to find out if the cell proliferation in the canine mammary carcinoma cell line CMT-U27 was affected upon stimulation of oxytocin, and to investigate the presence of oxytocin receptors in these cells. The cell proliferation was examined by using an ELISA-kit, where the absorbance measured is relative to the amount of living cells.

Basmobilen

Today?s cell phones include more and more functionality, it is no longer uncommon to be able to connect to the Internet or take photos with the cell phone. In this thesis the question is if the cell phone users are interested in this new functionality. Are there people who are interested in a cell phone that in this thesis is called ?Basmobilen? (the entry level phone), which include the following functions; phone call, SMS, phone book, calling lists, clock and the possibility to change the call signal.

Förbättring av utnyttjandegrad i robotcell

When a company in the manufactory industry makes costly investments, it's important that these are used as much as possible. The company in this case claims that their invested robot cell, with CNC machine isn't used enough. The questions here are: How can we improve the use of the robot cell? Which products are appropriate for the production in the robot cell? As a method to come to a conclusion, an analysis has been made over the manufactured products. And also interviews with machine operators and the production management.

En vidareutveckling av förvaltningsmodellen vid systemförvaltningsprocessen

Detta arbete behandlar problemområdet systemförvaltning och är en vidareutveckling av förvaltningsmodellen vid systemförvaltningsprocessen. Vid systemförvaltningsarbetet finns det olika förvaltningsmodeller som kan vara ett stöd vid taktisk och operativ styrning samt administrativ kontroll.Systemförvaltningsmodellen består generellt av sju olika rekommenderade delmodeller där bland annat systemförvaltningsprocessen ingår. Modeller för systemförvaltningsprocessen bör förenkla, effektivisera och ge stöd när systemförfrågningar samt systemkrav inkommer från verksamhetsledningen eller systemanvändaren. Undersökningen i detta examensarbete fokuserar på en vidareutveckling av modellen Application Maintenace Cycle (AM/Cycle) som utvecklats av Peder Brandt.Vidareutvecklingen i detta arbete resulterar i en modell för systemförvaltningsprocessen, vilken benämns Application Maintenace Schedule Cycle (AMS/Cycle). Litteraturstudier och intervjuer har påvisat vissa svagheter med modellen AM/Cycle, vilket tagits i beaktande vid vidareutvecklingen av AMS/Cycle.

Ultraljud som diagnostiskt hjälpmedel vid subklinisk mastit hos ko :

This study was performed to investigate the possibility to use ultrasonography as a diagnostic tool for sub-clinical mastitis in dairy cows. Five cows with high cell counts, and four cows with low cell counts were selected as cases and controls, respectively, and their udders examined with ultrasound during a 5 week period. The image of the udders of cows with high cell counts exhibited small, hyper-echoic, rounded foci, approximately 1 cm in diameter, near the milk cisterns and the base of the teats. These changes were not found consistently in all cows with high cell count, however. Ultrasonography may be a valuable complementary tool in the diagnosis of sub-clinical mastitis in dairy cow, but more cases need to be monitored before its full value can be ascertained..

Tre metoder för diagnos av mastit i fält :

The objective of this work was to evaluate and compare three field methods for detection of mastitis, California Mastits Test (CMT), DeLaval cell counter DCC (DCC) and FMA2001 Farm Milk Analyzer (FMA2001). Furthermore, to investigate at what cell count level clinical symptoms of mastitis are seen, and finally to check if the clinical findings and cell counts could be related to bacteriological findings. DCC and FMA2001 are new analytic instruments to be used on dairy farms for detection of mastitis. CMT has been a widely used cow-side-test of milk quality in mastitis control efforts, but it cannot be used for estimating cell counts in scientific studies or investigations. Two hundred and eight quarter milk samples from 52 cows were analysed with DCC and CMT, and 168 of these samples with FMA2001. Microbiological examination was done on 38 milk samples with CMT scores of 4 and 5.

Human Stem Cell - European National Innovation Systems and Patents

The purpose of this paper is for the reader to realise how national innovation systems are deeply intertwined with the legal background of a country and to understand the processes that involves national innovation systems specifically regarding the stem cell / genetics research and how the need for specific community law must be considered targeting the stem cell patents. The legal part will try to answer: Why is it important given the actual state of the European stem cell national innovation systems for the European Commission to take a stand and tackle issues regarding the patenting of the human stem cell innovations? This is done from a country industry analysis (business approach) and then linking it with competition law from a community stand point of view (that tackles biotechnology issues). In order to achieve this the paper is divided into three separate analyses beginning with a theoretical background of general biotechnology / genetic terms that will enable the reader to have a general understanding of the importance of this kind or research ( genetics / stem cell research). The chosen countries case studies exemplify very diverse economies and development perspective from the traditionally R&D intensive to the least and from the biggest countries in Europe to one of the smallest, thus giving cultural, legal, economic and scientific variety..

Investigation of Syndecan-1 Ectodomain Isolated from Chinese Hamster Ovary (CHO) Cell Culture Medium

Syndecan-1 is a cell surface proteoglycan which participates in cell adhesion, differentiation, motility, morphogenesis and intracellular signaling. The two glycosaminoglycans heparan sulfate and chondroitin sulfate are covalently attached to the ectodomain of syndecan-1 via a tetra saccharide linkage sequence. However, the ectodomain can be modified having only one or neither of the glycosaminglycans attached. The glycosaminoglycans are capable of binding ligands such as fibroblast growth factors (FGFs) and support activation of receptors. The ectodomain is proteolytically cleaved from the cell surface by metalloproteinases in a process known as shedding.

Förstudie för automatisering av gjutgodsrensning

This thesis work has been performed at the Division of Assembly Technology at Linköping University for a period of ten weeks. The work is part of the project ProFlexA, which is a research project in collaboration between Linköping University, Lund University, and industrial partners such as Combi Wear Parts and Smålands Stålgjuteri AB.The casting process creates random incurred burrs and defects, which must be removed during a cleaning process to make sure that the cast can be sold. Automation has long been sought for the cleaning of castings due to, among other things, poor working conditions for staff, but this has proved difficult to implement with today's technology. Automation has for some time been available for more capital strong companies with large annual volumes, but for smaller companies with small-and medium-sized volumes, automation has not been an option.The goal of ProFlexA is to develop an automated cleaning cell aimed at small-and medium-sized volumes.The goal of the thesis is to do a pre study at ProFlexA?s partners on cleaning of castings, and develop concepts for automated cleaning of castings.By recording the process and cycle times, the cleaning of castings has been documented as it works today, and on this basis, information and statistics has been compiled.

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