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42 Uppsatser om Membrane - Sida 2 av 3
Mjölkningsfrekvensens inverkan på mjölkfettets kvalitet :
The milk production has developed rapidly the last years. The milk production per cow is increasing and the production units are larger with an increasing number of animals and a decreasing number of workers. Many milk producers invest in automatic milking systems (AM) to meet this change. In these systems the cows can voluntary decide milking frequency and usually the milking frequency are higher than two times per day. But how does the milking frequency effect the composition of the milk?
The aim of the present study was to study the effect of milking frequency on the milk composition and the milk fat quality.
Tjänligt vatten i kranen - Membranteknik gör det möjligt : En utredning av pilotförsök i Glemmingebro
Nanofiltration is a proper way of preparation of drinking water. The process has a lot in common with reverse osmosis where a semipermeable Membrane is used to separate a pure water flow from the remaining water. A pilot plant was used to ensure that nanofiltration is a suitable technology for a specific waterworks station in Glemmingebro, Ystad. The purpose was also to find out if a pH-adjustment is needed for feed water in a possible full scale plant. In this case nanofiltration is used mainly to remove sulphate and calcium since the raw water contains concentrations of these substances which exceed the limits for potable water. It is important to receive a high recovery (RC), otherwise the deliviery of water won?t be high enough.
Nya renings- och uppgraderingstekniker för biogas
Biogas is a renewable energy source that is produced by anaerobic digestion of organic mate-rial. In Sweden, biogas predominately comes from sewage water sludge and landfills or from organic waste of households and industries. Small scale digestion plants at farms are espe-cially expected to contribute to increased biogas production in the future. Biogas can be ob-tained directly in it?s raw form and used as fuel in a combustion chamber.
The RECK gene and invasive cancer development : the significance of RECK in angiogenesis and inhibition of matrix metalloproteinases
The RECK gene is a relatively new discovered gene with important implications for cancer research. The research has been primarily concentrated on the human gene with the ultimate aim to identify the invasive characteristics. Up regulated RECK is linked to significantly prolonged survival rates in patients with severe forms of malignancies.
RECK is normally expressed in all cells of the body and has an important role in the balance between destructive and constructive features of the extracellular matrix. The RECK protein is a Membrane-bound glycoprotein that inhibit matrix metalloproteinases which has the function of breaking down the ECM. There is a significant correlation between RECK gene expression and the formation of new vessels, presumably via the mediation of VEGF which is an important and powerful inducer of angiogenesis.
Comparison between different freezing and thawing methods for human spermatozoa
Preservation of cells and tissues by freezing at temperatures below 70°C has led to new possibilities for the storage of germ cells for fertility preservation. During the freezing process problems might occur, the greatest being ice crystallization which can cause Membrane destruction and thus cell death. To minimize this risk, solutions that reduce the freezing point can be added to reduce crystallization and increase survival rates. These solutions are called cryoprotectants. The best method for freezing is still not known.The aim of this study was to analyze the effect of various parameters on the survival rate of human semen frozen with liquid nitrogen.
Miljösystemanalys av VA-system i omvandlingsområden : fallstudie i Värmdö kommun
Wastewater handling of private sewage systems has become an all increasing matter. In Stockholm region the 90 000 private sewage systems contribute with larger phosphorus flows to the Baltic Sea than the two biggest sewage plants in the area, Henriksdal and Käppala, contribute together, even though these two plants purify wastewater from more than one million inhabitants.
When summer house areas turn into areas for permanent living ? transition areas ? the load on the existing systems increases, systems that already often are unsatisfying. In those areas it is not clear what the best system choice is; On-site systems for single households; Local collective systems or Connection to central systems.
Borrelia burgdorferi : metodutveckling och tillämpning avseende odling och resistensstudier mot komplement, särskilt interaktion med faktor H
The genus Borrelia is a widespread, pathogenic pest and the causative of among others borreliosis or Lyme disease. The vector for the bacteria is the hard tick, Ixodes ricinus and the infection is transferred through a bite. Untreated, Borrelia may cause arthritis, heart damage or neuroborreliosis. Infection is made possible through different strategies for avoiding the body?s complement system.
Metodundersökning av tre metoder för kvävemätning i en arktisk äng : Jämförelse mellan mätmetoderna extraktion, inkubation och jonbytesmembran (PRS-sond)
The purpose with this report was to compare three commonly occurring methods for measuring plant available nitrogen in soils. The methods extraction, incubation and Plant root simulator (PRS) probe - an ion exchange Membrane (Western Ag Innovations, Inc., Saskatoon, Canada) method were used and comparison between these methods were conducted. A full factorial experiment were set up in northern Finland with the treatments excluding herbivores, warming and fertilization to see how the inorganic nitrogen content in the soil was effected by the treatments. Soil cores were taken and from them a subsample was incubated for 18 days and thereafter analyzed for inorganic N in laboratory. PRS- probes were in the ground for 1 month.
Hund som komparativ modell för autoimmuna sjukdomar :
In this essay dog as a compatible model were put against human. The major histocompatibility complex (MHC) genes were compared between dogs, human, cat and mouse. To evaluate dog as a model and study similarities and differences was the aim with this review.
Dog as a model contributes to understand mechanisms behind autoimmune diseases and showed clearly histological similarities between human and dogs concerning the skin disease mucous Membrane pemphigoid (MMP)/cicatricial pemphgioid (CP). Further genetic evidence motivated the choice of using dog as a comprehensive model when the MHC-complex correlated with hypothyroiditis in Doberman dog as it does in human. Physiological similarities with low levels of thyroid hormones (T3 and T4) together with high level of thyroid releasing hormone (TSH) were found in the same way as in human.
Expression av PSI-N från Arabidopsis thaliana i E : coli
PSI-N is one of the subunits in eukaryotic Photosystem I (PSI) and is located on the lumenal side of the thylakoid Membrane. It is known to interact in the electron transport chain between plastocyanin and PSI, but the mechanism behind the interaction is still unclear. To achieve a better understanding of PSI-N´s role in the photosynthesis it is necessary to develop a method for purification of PSI-N. The goal with this project was to design a plasmid that encodes a fusion protein containing PSI-N. With use of proteases the fusion protein can be cleaved into purified PSI-N.
Expression av PSI-N från Arabidopsis thaliana i E.coli
PSI-N is one of the subunits in eukaryotic Photosystem I (PSI) and is located on the lumenal side of the thylakoid Membrane. It is known to interact in the electron transport chain between plastocyanin and PSI, but the mechanism behind the interaction is still unclear. To achieve a better understanding of PSI-N´s role in the photosynthesis it is necessary to develop a method for purification of PSI-N. The goal with this project was to design a plasmid that encodes a fusion protein containing PSI-N. With use of proteases the fusion protein can be cleaved into purified PSI-N.
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.
Itrakonazol till häst : en farmakokinetisk möjlighet?
Itraconazole is a third generation azol, a fungicide which acts by inhibiting ergerosterol synthesis in the fungal cell Membrane, and thereby disturbing fungal regeneration. It has proven to be less toxic, to have a broader spectrum of activity and to be more potent than its predecessor ketoconazole. Itraconazole is only available in therapheutics approved for human use. Pharmacokinetic studies has been performed in humans, dogs, cats and laboratory animals. Although itraconazole has been used tentatively with good effect against fungal infections in horses, no pharmacokinetic studies have yet been done.
4-1BB is up-regulated in human mast cells, when exposed to tumor conditioned medium
Mast cells have for a long time been known to accumulate around tumors (Maltby et al., 2009). Studies show that they may be important and sometimes essential in tumor angiogenesis, tumor growth and metastasis of tumors (Soucek, et al., 2007; Xiang et al., 2010). In an expression array study (Wensman et al, submitted manuscript) performed on mouse mast cells exposed to tumor conditioned medium, the gene 4-1BB was among the most up-regulated genes compared to control medium. 4-1BB codes for a Membrane receptor protein of the tumor necrosis factor superfamily and has been shown to be important in T cell regulation in tumor diseases. This study was performed to investigate if human mast cells up-regulate 4-1BB when they get exposed to tumor conditioned medium.
Molecular analysis of insecticide resistance in pollen beetle (Meligethes aeneus)
The escalating usage of pyrethroids has resulted in an increased awareness about resistance towards pyrethroids in insects. Pyrethroids inhibit voltage-sensitive sodium channels (VSSC) in nerve cell Membranes and are composed of synthetic molecules based on pyrethrins present in pyrethrum extracts from Chrysanthemum species. VSSC are transMembrane proteins that are important for electric signalling over the Membrane in insects. Mutations in the gene encoding the sodium channel have proved to be a common reason for resistance against pyrethroids. Pyrethroid resistance among pollen beetles is spread all over Sweden and also abroad and is increasing.