• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 92
  • 36
  • 14
  • 9
  • 8
  • 8
  • 5
  • 5
  • 4
  • 1
  • 1
  • 1
  • Tagged with
  • 233
  • 33
  • 31
  • 26
  • 21
  • 19
  • 18
  • 17
  • 17
  • 17
  • 14
  • 13
  • 13
  • 12
  • 12
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Biologicky aktivní metabolity významných zástupců rodu Magnolia / Bioactive metabolites of representative members in the genus Magnolia

Lakatošová, Ivana January 2019 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany Candidate: Ivana Lakatošová Supervisor: PharmDr. Anna Hošťálková, Ph.D. Title of Master's thesis: Bioactive metabolites of representative members in the genus Magnolia 2019, 72 p. Key words: Magnolia, secondary metabolites, traditional medicine, CNS bioactivity The aim of this Master's thesis was to summarise current knowledge of significant secondary metabolites of species Magnolia officinalis and Magnolia obovata, and their biological activity. Botanical features of genus Magnolia were defined and described, followed by the classification of bioactive compounds isolated from species Magnolia officinalis and Magnolia obovata. The Master's thesis focused predominantly on the effects of biphenol compounds of magnolol and honokiol, which have been subjected to many studies. The main attention was given to the immunosuppressive effect and pharmacologic effects on the nervous system. Essential oils were observed to have an anti-inflammatory and a myorelaxant effect. Alkaloids and neolignans, which had been known to relax spasms of skeletal muscles, expressed neuroprotective activity. Neolignans were shown to have the inhibitory effect on bacteria, viruses and pathogenic fungi. They also proved themselves to be...
32

Postoperativ smärtbehandling till barn med hjärntumör

Rinaldo, Carina, Johansson, Karin January 2010 (has links)
Smärta i samband med intrakraniell kirurgi liknar smärta i samband med all annan form av kirurgi. Syftet var att granska hur barn med hjärntumör smärtbedömts och smärtbehandlats postoperativt efter tumörkirurgi. Metod: Totalt har journaler för 40 barn (20 barn på Akademiska barnsjukhuset i Uppsala och 20 barn på Astrid Lindgrens barnsjukhus vid Karolinska sjukhuset, Stockholm) som opererats för tumörer i hjärnan granskats, avseende smärtbedömning, användandet av smärtskalor, farmakologiska och ickefarmakologisk smärtbehandling de tre första postoperativa dygnen. Resultat: Studien visade att smärtskattning med smärtskalor användes på 12 av 40 barn. Den vanligaste formen av smärtbedömning som återfanns dokumenterad var en bedömning av sjuksköterskan. På Akademiska sjukhuset återfanns ingen dokumenterad smärtbedömning i 60 % av de granskade dygnen, på Astrid Lindgrens barnsjukhus var motsvarande siffra 20 %. De vanligaste läkemedlen som används på båda sjukhusen var paracetamol och opioider, framförallt morfin. Vid Astrid Lindgrens barnsjukhus används företrädelsevis stående ordinationer med paracetamol i kombination med opioidinfusioner. Vid Akademiska sjukhuset används framförallt paracetamol som stående ordination och opioidinjektioner som vid behovsordinationer. I dokumentationen återfanns ingen ickefarmakologisk behandling. För totalt 6 barn fanns omnämnt olika typer av distraktion eller tröst. Slutsats: Slutsatsen blir att utifrån journaldokumentation är systematisk smärtskattning av barn som opererats för tumörer i hjärnan, och utvärdering av given smärtbehandling bristfällig. / Pain in relation to intracranial surgery is similar to pain in relation to all other kind of surgery. Aim: The aim of this study was to review how children with brain tumour were assessed and treated for postoperative pain after tumour surgery. A total of 40 charts of children (20 children at Akademiska University Hospital and 20 children at Astrid Lindgren Children’s Hospital) who had gone through brain surgery have been reviewed with respect to pain assessment, use of assessment tools, pharmacological and nonpharmacological treatment the first tree days after surgery. Result: This study showed that pain assessment tools were used for 12 out of 40 children. The most used documented way of pain assessment was an assessment by the nurse. At the Akademiska University Hospital no documented pain assessment was performed in 60% of the reviewed days. At Astrid Lindgren Children’s Hospital the corresponding number was 20%. The most common drugs used at both hospitals were paracetamol and opioids, particularly morphine. At Astrid Lindgren Children’s Hospital they preferably used standing prescriptions of paracetamol in combination with morphine. At the Akademiska University Hospital they used paracetamol as a standing prescription and opioids as an on demand prescription. In the documentation no nonpharmacological treatment was found. For 6 children there was documentation of different types of distraction or consolation. Conclusion: The conclusion from the study of the documentation is that systematic pain assessment of children who had gone through brain surgery and evaluation of given pain treatment is insufficient.
33

Delivery of Cdc42, Rac1, and Brain-derived Neurotrophic Factor to Promote Axonal Outgrowth After Spinal Cord Injury

Jain, Anjana 09 July 2007 (has links)
Injury severs the axons in the spinal cord causing permanent functional loss. After injury, a series of events occur around the lesion site, including the deposition of growth cone inhibitory astroglial scar tissue containing chondroitin sulfate proteoglycan (CSPG)- rich regions. It is important to encourage axons to extend through these inhibitory regions for regeneration to occur. The work presented in this dissertation investigates the effect of three proteins, constitutively active (CA)-Cdc42, CA-Rac1, and brain-derived neurotrophic factor (BDNF) on axonal outgrowth through CSPGs-rich inhibitory regions after spinal cord injury (SCI). Cdc42 and Rac1 are members of the Rho GTPase family and BDNF is a member of the neurotrophin sub-family. These three proteins affect the actin cytoskeleton dynamics. Therefore, Cdc42, Rac1, and BDNF promote axonal outgrowth. The effect of CA-Cdc42 and CA-Rac1 on neurite extension through CSPG regions was determined in an in vitro model. Rac1 and Cdc42 s ability to modulate CSPG-dependent inhibition has yet to be explored. In this study, a stripe assay was utilized to examine the effects of modulating all three Rho GTPases on neurite extension across inhibitory CSPG lanes. Alternating laminin (LN) and CSPG lanes were created and NG108-15 cells and E9 chick dorsal root ganglions (DRGs), were cultured on the lanes. Using the protein delivery agent Chariot, the neuronal response to exposure of CA and dominant negative (DN) Rho GTPases, along with the bacterial toxin C3, was determined by quantifying the percent ratio of neurites crossing the CSPG lanes. CA-Cdc42, CA-Rac1, and C3 transferase significantly increased the number of neurites crossing into the CSPG lanes compared to the negative controls for both the NG108-15 cells and the E9 chick DRGs. We also show that these mutant proteins require the delivery vehicle, Chariot, to enter the neurons and affect neurite extension. Therefore, activation of Cdc42 and Rac helps overcome the CSPG-dependent inhibition of neurite extension. In an in vivo study, CA-Cdc42 and CA-Rac1 were locally delivered into a spinal cord cavity. Additionally, BDNF was delivered to the lesion site, either individually or in combination with either CA-Cdc42 or CA-Rac1. The dorsal over-hemisection model was utilized, creating a ~2mm defect that was filled with an in situ gelling hydrogel scaffold containing lipid microtubules loaded with the protein(s) to encourage axons. The lipid microtubules enable slow release of proteins while the hydrogel serves to localize them to the lesion site and permit axonal growth. The results from this study demonstrate that groups treated with BDNF, CA-Cdc42, CA-Rac1, BDNF/CA-Cdc42, and BDNF/CA-Rac1 had significantly higher percentage of axons from the corticospinal tract (CST) that traversed the CSPG-inhibitory regions, as well as penetrate the glial scar compared to the untreated and agarose controls. Although axons from the CST tract did not infiltrate the scaffold-filled lesion, NF-160+ axons were observed in the scaffold. Treatment with BDNF, CA-Cdc42, and CA-Rac1 also reduced the inflammatory response, quantified by analyzing GFAP and CS-56 intensity for reactive astrocytes and CSPGs, respectively, at the interface of the scaffold and host tissue. Therefore, the local delivery of CA-Cdc42, CA-Rac1 and BDNF, individual and combination demonstrated the ability of axons to extend through CSPG inhibitory regions, as well as reduce the glial scar components.
34

Microsystems for In Vitro CNS Neuron Study

Park, Jaewon 2011 December 1900 (has links)
In vertebrate nervous system, formation of myelin sheaths around axons is essential for rapid nerve impulse conduction. However, the signals that regulate myelination in CNS remain largely unknown partially due to the lack of suitable in vitro models for studying localized cellular and molecular basis of axon-glia signals. We utilize microfabrication technologies to develop series of CNS neuron culture microsystems capable of providing localized physical and biochemical manipulation for studying neuron-glia interaction and neural progenitor development. First, a circular neuron-glia co-culture platform with one soma-compartment and one axon/glia compartment has been developed. The device allows physical and fluidic isolation of axons from neuronal somata for studying localized axon-glia interactions under tightly controlled biochemical environment. Oligodendrocyte (OL) progenitor cells co-cultured on isolated axons developed into mature-OLs, demonstrating the capability of the platform. The device has been further developed into higher-throughput devices that contain six or 24 axon/glia compartments while maintaining axon isolation. Increased number of compartments allowed multiple experimental conditions to be performed simultaneously on a single device. The six-compartment device was further developed to guide axonal growth. The guiding feature greatly facilitated the measurement of axon growth/lengths and enabled quantitative analyses of the effects of localized biomolecular treatment on axonal growth and/or regeneration. We found that laminin, collagen and Matri-gel promoted greater axonal growth when applied to somata than to the isolated axons. In contrast, chondroitin sulfate proteoglycan was found to negatively regulate axon growth only when it was applied to isolated axons. Second, a microsystem for culturing neural progenitor cell aggregates under spatially controlled three-dimensional environment was developed for studies into CNS neural development/myelination. Dense axonal layer was formed and differentiated OLs formed myelin sheaths around axons. To the best to our knowledge, this was the first time to have CNS myelin expressed inside a microfluidic device. In addition, promotion of myelin formation by retinoic acid treatment was confirmed using the device. In conclusion, we have developed series of neuron culture platforms capable of providing physical and biochemical manipulation. We expect they will serve as powerful tools for future mechanistic understanding of CNS axon-glia signaling as well as myelination.
35

Principy neurochirurgické a neurointenzivistické likvorologie / The principles of neurosurgical and intensive care liquorology

Kelbich, Petr January 2015 (has links)
The principles of neurosurgical and neurointensive care liquorology We observed the development of the cerebrospinal fluid (CSF) patterns in 120 patients after bleeding in the CNS (central nervous system). We used our original cytological- energetic principle to investigate 1453 samples of the CSF from these patients. The principal aim of our investigation is the detection of immunocompetitive cells in the CSF and the specification of their activation via the coefficient of energy balance (KEB). Furthermore we evaluated the numbers of erythrocytes and leucocytes in the CSF and also the catalytic activities of the aspartate aminotranspherase (AST) in the CSF as biomarkers of structural disorder of the CNS. Our goal was to evaluate a three week long development of the CSF patterns to gain more accurate information for a more effective therapy and for a better prediction of further clinical development of these patients. We confirmed that following biomarkers were unfavourable for the development of the CSF compartment and probably the CNS as a whole: higher extent of bleeding in the CNS; higher frequency of the neutrophile granulocytes in the CSF compartment; higher extent of anaerobic metabolism in the CSF compartment; higher level of the catalytic activity of the AST in the CSF; higher age...
36

Progress in Global Air Traffic Management (GATM) Avionics System Test at the Air Force Flight Test Center

Switzer, Earl R., Fleishans, Amy D. 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents a progress report on Global Air Traffic Management (GATM) avionic system test activities at the Air Force Flight Test Center. In many parts of the world today the continuing growth of commercial air traffic is running up against limits brought on by overuse of aviation resources. Air corridors in Europe and on transoceanic air routes are operating at maximum capacity. Civil Aviation Authorities (CAAs) are working these challenges on two levels—near-term incremental improvements and long-term visionary changes. Each country has a CAA; ours being the Federal Aviation Administration (FAA). Near-term solutions focus on better utilization of resources such as air space and frequency spectrum and improved performance of air traffic control facilities. Long-term visionary changes, such as free flight, could fundamentally change the current civil aviation business process model. CAA policies and standards are driving near-term improvements and migration toward long-term objectives. This initiative is referred as Communication Navigation Surveillance/Air Traffic Management (CNS/ATM). Implementation of the U.S. military’s vision, Global Reach/Global Power, requires the ability to rapidly deploy armed forces to major regional conflicts anywhere in the world, and to sustain these forces for as long as it takes to resolve these conflicts. To achieve this goal and accomplish rapid deployments while at the same time minimizing costs, the Air Force has adopted a solution that makes extensive use of CNS/ATM. The Air Force calls its initiative Global Air Traffic Management (GATM). Air Force aircraft equipped with GATM avionics will be able to use CNS/ATM capabilities such as reduced vertical separation minimum (RVSM), 8.33 kHz data links, automatic dependent surveillance - broadcast (ADS-B), and global communication networks. These capabilities make possible improved flight safety, lower fuel costs, and quicker turn times. The Air Force Flight Test Center supports the GATM initiative by providing Air Traffic Control (ATC) Communications Test Facilities and Avionic System Test (ACTFAST) capabilities to support aircraft modification programs.
37

INFLUENCE OF THE SEROTONERGIC SYSTEM ON PHYSIOLOGY, DEVELOPMENT, AND BEHAVIOR OF DROSOPHILA MELANOGASTER

Dasari, Sameera 01 January 2007 (has links)
The regulation and modulation of the serotonergic system is clinically significant in humans. Abnormally low levels of serotonin can result in depression and conditions like panic disorder, obsessive-compulsive disorder, social anxiety disorder, sudden infant death syndrome, and eating disorders. The mechanistic role of serotonin (5-HT) on the neural circuits related with these diseases is not definitively known. Drosophila is a simple model system that provides an advantage over vertebrates to modify genetically and for electrophysiological studies on identifiable cells. In this organism the sensory-CNS-motor circuit is modulated by 5-HT, octopamine (OA), and dopamine (DA), which gives one insight that these neuromodulators are playing a role in central neuronal circuits. The role of 5-HT in the behavior and development of Drosophila melanogaster larvae is being studied. p-CPA (para-chlorophenylalanine) blocks the synthesis of 5-HT by inhibiting tryptophan hydroxylase. The development, behavior and physiology in 3rd instar larvae are affected after feeding this drug. MDMA (3,4 methylenedioxyamphetamine), an analog of methamphetamine is a drug of abuse that has been shown to cause depletion of 5-HT from nerve terminals. It causes the 5-HT transporter to work in reverse. Thus, a dumping of 5-HT results. In Drosophila 3rd instar larva development, physiology and behavior are effected when MDMA is fed throughout their development period. Also at the fly neuromuscular junction, (NMJ) MDMA is causing more evoked vesicular release of glutamate from the presynaptic nerve terminal. Also using anti-sense expression of the 5-HT2dro receptor, role of 5-HT and one of its receptors is studied on development, physiology and behavior. Knock down of 5-HT2dro resulted in developmental delay. Physiology and behavior were also abnormal in these animals.
38

Neuroembryology.

Darnell, Diana, Gilbert, Scott F 01 1900 (has links)
How is it that some cells become neurons? And how is it that neurons become organized in the spinal cord and brain to allow us to walk and talk, to see, recall events in our lives, feel pain, keep our balance, and think? The cells that are specified to form the brain and spinal cord are originally located on the outside surface of the embryo. They loop inward to form the neural tube in a process called neurulation. Structures that are nearby send signals to the posterior neural tube to form and pattern the spinal cord so that the dorsal side receives sensory input and the ventral side sends motor signals from neurons to muscles. In the brain, stem cells near the center of the neural tube migrate out to form a mantel zone, and a set of dividing cells from the mantle zone migrate further to produce a second set of neurons at the outer surface of the brain. These neurons will form the cerebral cortex, which contains six discrete layers. Each layer has different connections and different functions. WIREs Dev Biol 2017, 6:e215. doi: 10.1002/wdev.215 For further resources related to this article, please visit the WIREs website.
39

Oligodendroglial anillin facilitates septin assembly to prevent myelin outfoldings

Erwig, Michelle Scarlett 28 January 2019 (has links)
No description available.
40

The modulation of locomotor central pattern generators by octopamine and Tyramine indrosophila larvae

Ockert, Waldemar January 2012 (has links)
Movement is controlled by neuronal central pattern generator (CPG) networks that are segmentally organised in organisms across the animal kingdom. The precise role of neuromodulators in the function, development and, particularly, the maintenance of these circuits is currently unresolved. This study investigates the effects of chronically altered signalling of tyramine and/or octopamine, two well established neuromodulators, in Drosophila larval locomotion. It shows that tyramine reduces crawling speed in larvae, whereas octopamine increases speed up to a physiological maximum. Changes in crawling speed are mediated by modulating stride duration, whilst stride length remains constant. These two neuromodulators also affect segmental muscle contraction and relaxation rates, indicative that the effects on crawling speed are likely to be at least partially due to modulatory effects on muscle physiology. Muscle recordings from muscle M6 in two adjacent segments, during fictive forward locomotion show that stride duration is influenced by a variable time delay between segmental CPG outputs. Frequency and duration of individual segmental outputs, by contrast, remains constant. The behavioural and electrophysiological data suggest, therefore, that the segmental locomotor CPG outputs remain constant in response to chronically altered neuromodulatory signalling. This study also identified a close spatial proximity of motor neuronal dendritic branches and putatively octopaminergic and/or tyraminergic synaptic terminal varicosities in the ventral nerve cord (VNC) neuropil. Moreover, manipulation of a putatively octopaminergic and/or tyraminergic subpopulation of interneurons, located in anterior brain regions, is sufficient to induce a similar, albeit smaller, larval crawling deficit. This indicates that the effects of locomotion may be induced in the central nervous system. This is confirmed in identified motor neurons as chronic changes in octopaminergic and/or tyraminergic signalling increase the frequency of bursting of action potential firing. In addition, the synaptic current amplitudes are substantially reduced in both ventral and dorsal muscle- innervating motor neurons, indicative of an effect to presynaptic excitation. In contrast, the function of neuromuscular junction remains largely unchanged. Taken together, this data shows that neuromodulation is sufficient to alter the output of a relatively small group of neurons, that comprise the locomotor CPG. The site of action of these modulators is, however, likely to be diverse.

Page generated in 0.0401 seconds