1,233 research outputs found
Paraneoplastic Antibodies
Paraneoplastic neurological syndromes (PNS) are remote effects of cancer. These are not caused by invasion of the tumor or its metastasis nor by other direct effects of the tumor or its treatment. PNS are rare, affecting less than 0.1% of all cancer patients. PNS have a subacute course, leaving the patient severely disabled in weeks to months. In most cases PNS precede the diagnosis of cancer.
The discovery of paraneoplastic antineuronal antibodies facilitated the diagnosis. ‘Well characterized onconeural antibodies’ are defined by recognizable patterns on rat brain immunohistochemistry and positive immunoblotting on recombinant antigen proteins. These are exclusively found in patients with cancer and include anti-Hu, Yo, CV2, Ri, Ma2 and amphiphysin. These antigens represent intracellular proteins, so in PNS damage is caused by cellular immune responses, explaining the poor response to immune modulating treatment and poor prognosis. We identified the anti-Tr antigen as the transmembrane protein Delta/ Notch-like epidermal growth factor-related receptor (DNER).
More recently a still growing number of autoantibodies directed against synaptic or neuronal cell-surface antigens has been identified, including mGluR1, NMDA, AMPA and GABA receptors. These autoantibodies have direct access to their target antigen and are potentially pathogenic. The associated clinical syndromes may be paraneoplastic or may represent an autoimmune encephalitis (without underlying tumor). Patients harboring autoantibodies directed against synaptic or neuronal cell-surface antigens respond favorably to immunotherapy with a good outcome in up to 80%.
This thesis focuses on paraneoplastic antineuronal antibodies and includes studies on new methods of autoantibody detection, identification of novel paraneoplastic antigen(s) and the description of clinical syndromes associated with newly detected paraneoplastic antibodies
Anisotropic pinned/biased magnetization in superlattices
The exchange coupling at the interfaces of magnetic superlattices consisting
of ferromagnetic and antiferromagnetic grown on (001)
oriented is studied with in-plane and out-of-plane orientations, with
respect to the substrate plane, of the cooling magnetic field. The
magnetization of the in-plane, field cooled hysteresis loop is lower than the
corresponding in-plane zero-field-cooled hysteresis loop. The out-of-plane
field cooled hysteresis loop is shifted, from the origin, along the graphical
magnetization axis. We attribute this irreversible rotation of the moment to
the pinning/biasing of spin in the layer in the vicinity of
interfaces by the antiferromagnetic layer.Comment: To be published in Eur. Jour. Phys. B for a topical issue on "new
trends in magnetic exchange bias phenomena
Reorientation Transition in Single-Domain (Ga,Mn)As
We demonstrate that the interplay of in-plane biaxial and uniaxial anisotropy
fields in (Ga,Mn)As results in a magnetization reorientation transition and an
anisotropic AC susceptibility which is fully consistent with a simple single
domain model. The uniaxial and biaxial anisotropy constants vary respectively
as the square and fourth power of the spontaneous magnetization across the
whole temperature range up to T_C. The weakening of the anisotropy at the
transition may be of technological importance for applications involving
thermally-assisted magnetization switching.Comment: 4 pages, 4 figure
Прибыльность предприятия и резервы ее повышения
Целью данной работы является анализ факторов, влияющих на прибыль, анализ показателей оценки
прибыли, и разработка рекомендаций по увеличению прибыли
Mapping magnetic sources at the millimeter to micrometer scale in dunite and serpentinite by high-resolution magnetic microscopy
Rock samples can have wide range of magnetic properties depending on composition, amount of ferromagnetic minerals, grain sizes and microstructures. Here, we used scanning magnetic microscopy, a highly sensitive and high-resolution magnetometric technique to map remanent magnetic fields over a planar surface of a rock sample. The technique allows for the investigation of discrete magnetic mineral grains, or magnetic textures and structures with submillimeter scale resolution. Here, we present a case-study of magnetic scans of pristine and serpentinized dunite thin sections from the Reinfjord Ultramafic Complex, in northern Norway. The magnetic mineralogy is characterized by electron microprobe, scanning electron- and optical-microscopy, and with rock magnetic methods. In serpentinized samples the magnetic carrier is end-member magnetite occurring as large discrete grains and small grains in micron scale veins. By contrast, the pristine dunite sample contains large Cr-spinel grains with very fine equant exsolutions ranging in composition from ferrichromite to end-member magnetite. Forward and inverse modeling of the magnetic anomalies is used to determine the remanent magnetization directions and intensities of discrete magnetic sources observed in the scanning magnetic microscopy. The fine-scale magnetization of the rock sample is used to investigate the magnetic carriers and the effect of serpentinization on the magnetic properties of the dunite. Modeling shows that the dipolar magnetic anomalies that are mapped by scanning magnetic microscopy are caused by grains with heterogeneous magnetic sources. The intensity of the magnetization and the amount of magnetic minerals are higher in the serpentinized sample than the pristine dunite sample, consistent with the measured bulk magnetic properties. Furthermore, the serpentinized samples show a larger variability in the direction of the magnetization and a stronger heterogeneity with respect to the pristine sample. The ability to rigorously associate components of the bulk magnetic properties to individual mineral phases creates new possibilities for rock magnetic, paleomagnetic, and exploration applications
Evaluation of European Land Data Assimilation System (ELDAS) products using in site observations
Three land-surface models with land-data assimilation scheme (DA) were evaluated for one growing season using in situ observations obtained across Europe. To avoid drifts in the land-surface state in the models, soil moisture corrections are derived from errors in screen-level atmospheric quantities. With the in situ data it is assessed whether these land-surface schemes produce adequate results regarding the annual range of the soil water content, the monthly mean soil moisture content in the root zone and evaporative fraction (the ratio of evapotranspiration to energy available at the surface). DA considerably reduced bias in net precipitation, while slightly reducing RMSE as well. Evaporative fraction was improved in dry conditions but was hardly affected in moist conditions. The amplitude of soil moisture variations tended to be underestimated. The impact of improved land-surface properties like Leaf Area Index, water holding capacity and rooting depth may be as large as corrections of the DA systems. Because soil moisture memorizes errors in the hydrological cycle of the models, DA will remain necessary in forecast mode. Model improvements should be balanced against improvements of DA per se. Model bias appearing from persistent analysis increments arising from DA systems should be addressed by model improvement
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