Sökning: "K channels"

Visar resultat 1 - 5 av 135 avhandlingar innehållade orden K channels.

  1. 1. Ion Transport in Glial and Neuroblastoma Cells

    Författare :Sonya K. A. Juthberg; Linköpings universitet; []
    Nyckelord :MEDICINE; MEDICIN;

    Sammanfattning : The aim of this thesis has been to increase our understanding of the ion channel function and the ion transport mechanisms in glial cells. The analysis has also covered Na channel function in human neuroblastoma cells in order to get a basis for similar studies of glial cells In paper I isotopes 42K and 201 Tl were used to compare the K+ transport properties in cell lines from human malignant gliomas (U-251MG and Tp-378MG), carcinomas, and brain metastasis. LÄS MER

  2. 2. Colonic barrier function in ulcerative colitis - Interactions between ion and mucus secretion

    Författare :Jenny K Gustafsson; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :intestine; mucus; ion transport; colitis; CFTR;

    Sammanfattning : Anion and mucus secretions have traditionally been looked upon as two separate parts of the epithelial defense system. The importance of anion secretion has been attributed to its role in creating the driving force for fluid secretion that flushes the epithelium from bacteria, while mucus secretion ensures protection via the mucus layer that forms a physical barrier between the bacteria and the epithelium. LÄS MER

  3. 3. Improved Techniques for Retransmission and Relaying in Wireless Systems

    Författare :Chaitanya V. K. Tumula; Erik G. Larsson; Tobias J. Oechtering; Linköpings universitet; []
    Nyckelord :Hybrid-ARQ; relaying schemes; superposition coding; 3GPP- LTE; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : The last three decades have seen significant advances in the wireless communication field. As the data rates of wireless systems are increasing, the demand for mobile services also is increasing rapidly. Like other natural resources, radio spectrum suitable for mobile wireless communications is also limited. LÄS MER

  4. 4. HARQ Systems: Resource Allocation, Feedback Error Protection, and Bits-to-Symbol Mappings

    Författare :Chaitanya Tumula V. K.; Erik G. Larsson; Danyo Danev; Ana I. Pérez-Neira; Linköpings universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HARQ Systems; Resource Allocation; Geometric Programming; 3GPP-LTE; PUCCH Format 2; Complex-field coding; Signal Space Diversity; Optimization; Superposition Coding;

    Sammanfattning : Reliability of data transmission is a fundamental problem in wireless communications. Fading in wireless channels causes the signal strength to vary at the receiver and this results in loss of data packets. To improve the reliability, automatic repeat request (ARQ) schemes were introduced. LÄS MER

  5. 5. The interplay of ions in the stimulation of the pancreatic -cell

    Författare :Michael Eberhardson; Uppsala universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cell biology; diabetes; pancreatic β-cells; cytoplasmic calcium; oscillations; glucose; tetrodotoxin; tolbutamide; veratridine; tetraethylammonium; quinine; cesium; H2DIDS; furosemide; transients; microfluorometry; fura-2; MQAE; calcium channels; potassium channels; sodium channels; chloride channels; Cellbiologi; Cell biology; Cellbiologi; medicinsk cellbiologi; Medical Cell Biology;

    Sammanfattning : Glucose stimulation of insulin release is mediated by depolarisation of the pancreatic β-cells with accompanying entry of Ca2+ through voltage-dependent channels. An important feature of the glucose-induced depolarisation is its rhythmicity causing oscillations of the cytoplasmic Ca2+ concentration ([Ca2+]i), which trigger pulsatile release of insulin. LÄS MER