julilili42/papers huggingface dataset:
Redefining fetal evoked fields with biomagnetic recordings over the whole maternal abdomen
2005-08-24

The development of a technique for the recording of fetal brain activity has been highly limited by the inaccessibility of the developing human brain in utero. Based on the needs of resolution and a noninvasive nature, only biomagnetic measurements are suitable for the determination of the integrity of the fetal brain on a routine basis. We have built a new biomagnetic measurement device dedicated to this task. The main construction concerns were those of patient comfort, ease of performance of standard measurements, and appropriate spatial and temporal resolution. Our initial evaluation of the instrument has shown that it is capable of obtaining signals traditionally regarded as evoked fetal fields. Our results also show that this interpretation has to be made very carefully and that a large scale array is more appropriate for the extraction of fetal brain signals. In future it will be necessary to develop more controlled protocols by combining fetal behavioural tests and fetal auditory evoked field (fAEF) recordings, to generate convincing evidence that reported fAEF are generated in the fetal brain.
Synthesis of Jasplakinolide Analogues Containing a Novel ω‐Amino Acid
2005-08-24

Abstract The synthesis of the ω‐amino acid 4 is described utilizing a two‐dimensional synthesis strategy combined with an enzymatic differentiation of homotopic ester groups. The amino acid 4 features two non‐bonded interactions that result in conformational constraints on a cyclic construct. This amino acid was incorporated into the four macrolactams 17 , 22 , 31 , and 37 . The ring in 17 and 22 is 18‐membered, whereas 31 and 37 have a 19‐membered ring. The pairs with the same ring size differ in a N‐methyl group. For the larger macrolactams ( 31 and 37 ) conformational analysis showed that the macrocyclic rings are somewhat more rigid than in the natural lead, the depsipeptide jasplakinolide. Nevertheless, their conformations are comparable to the natural product. There are no intramolecular hydrogen bonds, neither is the cis ‐rotamer populated in the N‐methyl compound 37 . Due to the increased flexibility of the smaller macrolactams 17 and 22 and signal overlap, a distinct solution structure could not be obtained for these compounds. The amino acid 4 should be useful for restricting the conformation of other small peptides.
Polymer Coated Capacitive Microintegrated Gas Sensor
2005-08-24

Detection of volatile organic compounds (VOCs) is important for various environmental and industrial applications such as alarm devices for pollution or building control purposes. The feasibility of smart capacitive chemical micro sensors in CMOS technology has already been assessed [I]. The objective of the current investigation was to elabo rate an analytical model for the gas/polymer interaction and to compare FEM simulations and measurements. In order to develop a model for the interactions between VOCs and the polymer layers, systematic measurementsof various parameters affecting the sensing layer were carried out. The efforts were concentrated on commercially avail able polyetherurethane (PUT, Thermedics Inc., USA), as the sensitive layer.
Solid Electrolytes For Gas Sensing At High Temperatures. Multi Electrode Setup To Analyze Gas Mixtures
2005-08-24

Diffusion limited amperometric cells based on stabilized zirconia with a sequential arrangement of several electrodes have been developed for the analysis of exhaust gas mixtures. Such a multi electrode setup allows a spatial separation of different electrode reactions which may be used to monitor the concentrations of several gases at the same time. First results obtained with a cell with two electrodes operating in NO/O/sub 2/ gas mixtures demonstrate the feasibility of this approach by a simultaneous detection Of O/sub 2/ and NO.
A COprocessor for KOhonen's self-organizing map (COKOS)
2005-08-24

Presents a system which enables easy and fast computation of Kohonen's self-organizing map (SOM). It is a hardware supported system consisting of different parts. A neural coprocessor (COKOS) is connected to a personal computer (PC) by a special, asynchronous interface. The neural coprocessor works vector-component-parallel and processing-element-serial and speeds up the performance of Kohonen's algorithm of the self-organizing map by magnitude. A user friendly interface (ULTIKOS) supports the preprocessing of the input data and the control and assessment of the learning process.
Linearisation In Multicomponent Analysis Based On A Hybrid Sensor-array With 19 Sensor Elements
2005-08-24

We present experimental results obtained with a modular hybrid sensor-array for gas mixture analysis and for odour sensing. [1] Sensor elements are based on mass sensitive, electrochemical, field effect, and electrical transducers. Linearisation in such a complex setup is an essential feature of the subsequent multicomponent analysis. Three different methods are applied for this task. To characterize in a first simple example the different performances of these approaches, we analysed various mixtures of carbon monoxide (CO) and toluene (tol.) in air. Principal Component Regression (PCR) and Partial Least Squares (PLS) were used for the quantitative multicomponent analysis.
Analysis Of Complex Gas Mixtures By Pattern Recognition With Polymer Based Quartz Microbalance Sensor Arrays
2005-08-24

Polymer coated quartz microbalance gas sensor arrays were used to analyse quaternary mixtures of volatile or game compounds. The performance of the sensor arrays in combination with qualitative data evaluation utilising self-organising feature maps is described. The concept of context preservation artificial neural networks is compared to standard topology preservation with respect to its classification properties for model partitioning. In the studied case, context preserving maps yield more compact clusters with smaller map dimensions.
Ozone Detection In The Ppb- Range With Workfunction Sensors Operating At Room Temperature
2005-08-24

Thin evaporated films of potassium iodide (KI) are highly sensitive to ozone in workfunction measurements. Among various other materials KI is well suited for limit detection in the ppb- range in normal humid air with work function sensors like SGFET. The cross-sensitivities to other oxidants are comparatively small which is due to a redox system of highly oxidated states on the layer surface as is found by XPS analysis.
A New Affinity Biosensor: Self-assembled Thiols As Selective Monolayer Coatings Of Quartz Microbalances
2005-08-24

SUMMARY We investigated quartz microbalance (QMB) transducers for their use as affinity biosensors after coating with selfassembled peptide monolayers. With the aim of achieving a densely packed sensitive layer the Au substrates were examined first with X-ray photoelectron spectroscopy (XPS) and scanning force microscopy (SFM). The successful immunological reaction of the subsequently immobilized antigen and antibody was demonstrated by an due to the formation of a covalent bond between the gold and the sulfur. In the present study a synthetic peptide (epitope as antigen) with the amino acid sequence 135- 154 of the capsid protein VP 1 of the foot-and-mouth-disease virus (FMDV) was modified with o-hydroxyundecanethiol by a succinyl linker (HUT-peptide). Together with o-hydroxyundecanethiol (HUT) a mixed monolayer of these two compounds was formed by self-assembly from solution (Figure 1). This continuous epitope is recognized selectively by monoclonal and polyclonal antibodies against FMDV [2]. Our earlier studies with an impedance transducer indicated in principle the suitability of such monolayers for the use as an affinity biosensor [3]. With the aim of achieving a higher sensitivity and stability
The effect of low energy protons on the operational characteristics of EPIC-MOS CCDs
2005-08-24

The University of Tubingen 3.5 MeV Van de Graaf accelerator facility was used to investigate the effect of low energy protons on the performance of the European Photon Imaging Camera (EPIC), metal-oxide semiconductor (MOS), charge coupled devices (CCDs). Two CCDs were irradiated in different parts of their detecting areas using different proton spectra and dose rates. Iron-55 was the calibration source in all cases and was used to measure any increases in charge transfer inefficiency (CTI) and resolution of the CCDs as a result of proton damage. Additional changes in the CCD bright pixel table and changes in the low X-ray energy response of the device were examined. The Monte Carlo code SRIM was used to model the effect of a 10 MeV equivalent fluence of protons interacting with the CCD. Since the non-ionising energy loss (NIEL) function could not be applied effectively at such low proton energies. From the 10 MeV values, the expected CTI degradation could be calculated and then compared to the measured CTI changes.
Evaluation Of Dynamic Sensor Signals By Artificial Neural Networks
2005-08-24

Random walks have been used to calibrate neural nets for evaluating dynamic data (non-equilibrium signals) as they occur under realistic environmental conditions. The prediction of test data even at varied exposure times is possible for organic volatiles with low RMS errors in the range of 30 ppm. The neural nets consisted of feed-forward and recurrent nets. The results show that a careful selection of the training data is of major importance. In contrast the improvements by the recurrent nets or more sophisticated network architectures as compared with feed-forward nets were only small.
Performance And Limitations Of Reflectometric Fibre Optical Sensors For Voc Sensing Applications
2005-08-24

Interferometric optical sensors are known for the exact determination of path lengths. Equipped with appropriate sensitive polymer coatings, this effect can be used to monitor changes in VOC concentration in vapour phase and water. The performance and limitations of a fibre optical RUS-transducer are reported here with respect to optical components, temperature variation and properties of the polymer coating.
Expression of the immune-tolerogenic major histocompatibility molecule HLA-G in multiple sclerosis: implications for CNS immunity
2005-08-25

HLA-G is a non-classical major histocompatibility complex (MHC) class I antigen with highly limited tissue distribution under non-pathological conditions. Although capable of acting as a peptide-presenting molecule, its strong immune-inhibitory properties identify HLA-G as a mediator of immune tolerance with specific relevance at immune-privileged sites such as trophoblast or thymus. To assess the role of HLA-G in CNS immunity, we investigated its expression in brain specimens from patients with multiple sclerosis (n = 11), meningitis (n = 2) and Alzheimer's disease (n = 2) and non-pathological CNS controls (n = 6). Furthermore, cultured human microglial cells and CSF of patients with multiple sclerosis and controls were assessed. Furthermore, CSF from MS patients and controls, as well as cultured human microglial cells were assessed. Using several HLA-G specific mAb and immunohistochemistry, HLA-G protein was found strongly expressed in brain specimens from patients with multiple sclerosis while it was rarely detectable in the non-pathological control specimens. In multiple sclerosis brain specimens, HLA-G immunoreactivity was observed in acute plaques, in chronic active plaques, in perilesional areas as well as in normal appearing white matter. In all areas microglial cells, macrophages, and in part endothelial cells were identified as the primary cellular source of expression. HLA-G was also found in other disease entities (meningitis, Alzheimer's specimens) where expression correlated to activation and MHC class II expression on microglial cells. Importantly, ILT2, a receptor for HLA-G, was also found in multiple sclerosis brain specimens thus emphasizing the relevance of this inhibitory pathway in vivo. HLA-G mRNA and protein expression and regulation could also be corroborated on cultured human microglial cells in vitro. Further, expression of HLA-G in the CSF of multiple sclerosis patients and controls was analysed by flow cytometry and ELISA. Monocytes represented the main source of cellular HLA-G expression in the CSF. Corresponding to the observations with the tissue specimens, CSF mean levels of soluble HLA-G were significantly higher in multiple sclerosis than in non-inflammatory controls (171 +/- 31 versus 39 +/- 10 U/ml; P = 0.0001). The demonstration of HLA-G and its receptor ILT2 on CNS cells and in areas of microglia activation implicate HLA-G as a contributor to the fundamental mechanisms regulating immune reactivity in the CNS. This pathway may act as an inhibitory feedback aimed to downregulate the deleterious effects of T-cell infiltration in neuroinflammation.
Intrafamilial variability in fragile X–associated tremor/ataxia syndrome
2005-08-25

Abstract Fragile X–associated tremor/ataxia syndrome (FXTAS) is a progressive adult‐onset tremor/ataxia syndrome caused by premutations in the FMR1 gene. In cranial MRI, the most characteristic findings are bilateral T2 hyperintense lesions within the middle cerebellar peduncles. Here we present a sibpair of two affected brothers presenting with very different symptoms (typical FXTAS versus essential tremor‐like), disease progression, and MRI findings, illustrating broad intrafamilial variability of FXTAS. Also, their family history suggests further evidence of possible manifestation of FXTAS in women. © 2005 Movement Disorder Society
Microfabrication And Characterisation Of Microelectrode Arrays For In Vivo Nerve Signal Recording
2005-08-25

The present work was performed in the framework of the ESPRIT-project "INTER" aimed at the development of an "intelligent" artificial interface between the living nerve system and electronic devices. The design, the fabrication, and the characterisation of regeneration-type microelectrode arrays for in vivo recording of nerve signals is described here. The impedance of the microelectrodes could be decreased by electrochemical platinisation. An equivalent circuit is proposed to describe the response behaviour of these electrodes after different preparation steps.
A case study on interactive exploration and guidance aids for visualizing historical data
2005-08-25

In this paper, we address the problem of historical data visualization. We describe the data acquisition, preparation, and visualization. Since the data contain four dimensions, the standard 3D exploration techniques have to be extended or appropriately adapted in order to enable interactive exploration. We discuss in detail two interaction concepts: (1) navigation with one fixed dimension, and (2) quasi 4D navigation allowing to simultaneously explore the four-dimensional space. In addition, we also present a picture-in-picture display mode, enabling the user to interactively view the data, while "flying with" a particular event, tracking its motion in time and space. Finally, we present a technique for guided exploration and animation generation, allowing for a vivid gain of insight into the historical data.
Gravimetric Dielectric And Calorimetric Methods For The Detection Of Organic Solventvapours Using Poly(etherurethane) Coatings
2005-08-25

SUMMARY Cycloaliphatic poly(etherurethane) has been used as sensitive layer for the detection of organic solvent vapours such as ketones, alcohols, amines, alkanes, aromatic compounds and chlorinated hydrocarbons with quartz microbalances (QMB), interdigital capacitors (IDC) and calorimetric transducers. The sensor signals are completely reversible and reproducible at room temperature. Using QMB's even less than 10 ppm of nitrobenzene in air can be detected. The IDC measurements show particularly high sensitivities for alcohols. The different transducer parameters are discussed comparatively for the different organic volatiles.
Different Strategies For The Dynamical Calibration Of Gas Sensors
2005-08-25

Different strategies for the dynamical calibration of gas sensors have been applied to Quartz Microbalance polymer coated sensors exposed to binary mixtures of Toluene and Octane. White Gaussian Noise and steps signals are used for calibration and validation purposes. This work is the first attempt to a comparative analysis of diverse methods in gas sensor dynamic calibration.
Mass Sensitive Detection Of CO/sub 2/ By Aminogroup-functionalized Polymers
2005-08-25

A series of aminogroup-functionalized polymers was investigated as sensitive coatings for the detection Of CO/sub 2/ in the gas phase by using quartz microbalance transducers. The sensor signals are reversible with response and decay times in the order of minutes at operating temperatures between 25/spl deg/C and 70/spl deg/C. The long term stability and the cross sensitivities to other gases are also discussed.
A4 INTERACTION OF NMDA AND GROUP I METABOTROPIC GLUTAMATE RECEPTORS IN AVERSIVE LEARNING
2005-08-25

1Merz Pharmaceuticals, Behavioural Pharmacology, Frankfurt/Main, Germany 2University of Tübingen, Department of Neuropharmacology, Zoological Institute, Tübingen, Germany E-mail: [email protected] Abstracts of the 11th Biennial EBPS Meeting
Profuse and selective growth in vitro of rat spinal axons on a micro-patterned poly (ethylene imine) grid
2005-08-25

To distribute neurites (axons) along a surface and to guide them towards specific point targets we cultured spinal cord explants on coverslips printed with a micro-patterned grid of poly (ethylene imine) (PEI) lanes. The grid was prepared by micro-contact printing with silicone stamps. Spinal cord explants were resected from neonatal rats. A tiny bunch of glass filaments was used to ensure adhesion of the explant to the coverslip. One end of the bunch was glued to the coverslip while the other end pressed the explant firmly onto the coverslip. Spinal cord explants cultured in a collagen matrix, on a coverslip stamped with poly D-lysine (PDL), or on a coverslip uniformly coated with PEI or PDL were used as controls. Cultures were maintained for 6 days in vitro (div). Outgrowth from the explant was observed using phase contrast microscopy. None of the explants detached from the coverslip. Neurites emerged randomly from the explants, but upon crossing one of the grid lanes they subsequently followed the grid pattern. The outgrowing neurites were guided by the PEI lanes of the grid and reached lengths of up to 2400 /spl mu/m. After 6 div no signs of degeneration were observed in the outgrowth of explants cultured on a stamped coverslip or on a homogeneously coated coverslip, while degeneration did appear in the explants cultured in collagen after 4 div. Compared to control explants cultured on PDL (either on stamped or on uniformly coated coverslips), explants cultured on a micro-patterned PEI grid grew more profuse (more and longer neurites). Because these cultures can be easily manipulated, this paradigm is ideally suitable for studies of neuronal networks and for studies that necessitate the guidance of neurites towards a specific target (in culture), for instance the electrodes of a multi-electrode array in a culture dish.
Pesticide Detection With A Direct Optical Immunoprobe
2005-08-25

SUMMARY An approach for the detection of pesticides in water based on antibodies and optical detection is described. Sdective detection of the analyte is achieved by pesticide specific antibodies in a competitive test scheme. Unoccupied antibodies from the test mixture bind at the surface of an optical transducer. The amount of antibodies bound is inversdy related to the concentration of analyte in the sample. The time resolved detection of them binding process is based on white light reflectometry or evanescent field refractometry. Test midpoints at O.5ppb have been achieved, putting the EU drinking water limit (0. lppb) within reach.
Carbonate Based CO/sub2/ Sensors With High Performance
2005-08-25

SUMMARY Comparison of three different sodium carbonate based sensor types show that sensors with solid state references have a nearly drift-free response to CO2 changes (drift < 0.5 mV124 h). Gases as H20 (50% r.H.), CO (30 ppm), CH4 (200 ppm) had no significant influence on the performance of all sensor types. Small amounts of NO2 (100 ppm) lead to a reversible disturbance of the sensor signal only if the reference electrode is not sealed. It is shown that all sensor types resist to SO2 concentrations lower than 500 ppb because the formation of sodium sulphate is kinetically hindered. out CO2 sensing tests with a fixed relative humidity of 50%.
Case study on real-time visualization of virtual Tubingen on commodity PC hardware
2005-08-25

For psychophysical studies in spatial cognition a virtual model of the picturesque old town of Tubingen has been constructed. In order to perform psychophysical experiments in highly realistic virtual environments the model is based on high quality texture maps adding up to several hundreds of MBytes. To accomplish the required real-time frame updates, view frustum and occlusion culling without visibility pre-processing, levels of detail, and texture compression are applied in an interleaved manner. Shared memory communication and a standard PC with two commodity graphics cards is used to enable the powerful combination of those techniques because this combination is not yet available on a single graphics card.
High-Efficiency Deterministic Josephson Vortex Ratchet
2005-08-26

We investigate experimentally a Josephson vortex ratchet--a fluxon in an asymmetric periodic potential driven by a deterministic force with zero time average. The highly asymmetric periodic potential is created in an underdamped annular long Josephson junction by means of a current injector providing an efficiency of the device up to 91%. We measured the ratchet effect for driving forces with different spectral content. For monochromatic high-frequency drive the rectified voltage becomes quantized. At high driving frequencies we also observe chaos, subharmonic dynamics, and voltage reversal due to the inertial mass of a fluxon.
Short-Course Regimens of Artesunate-Fosmidomycin in Treatment of Uncomplicated Plasmodium falciparum Malaria
2005-08-26

ABSTRACT Fosmidomycin is effective against malaria, but it needs to be given for ≥4 days when used alone. We conducted a study of 50 children with Plasmodium falciparum malaria to evaluate the safety and efficacy of consecutively shortened regimens of artesunate-fosmidomycin (1 to 2 mg/kg of body weight and 30 mg/kg of body weight, respectively; doses given every 12 hours). All dosing regimens were well tolerated. Artesunate-fosmidomycin acted rapidly, resulting in consolidated geometric mean parasite and fever clearance times of 24 h and 15 h, respectively. Treatment regimens of ≥2 days led to cure ratios of 100% by day 14 (39/39; 95% confidence interval [95% CI], 91% to 100%). Most importantly, the 3-day regimen achieved 100% cure on day 28 (10/10; 95% CI, 69% to 100%). Treatment with artesunate-fosmidomycin was associated with transient grade I or II neutropenia (absolute neutrophil counts of 750 to 1,200/μl and 400 to 749/μl, respectively) in six or two patients, respectively. Artesunate-fosmidomycin demonstrates the feasibility and potential value of short-course artemisinin-based combination chemotherapy with rapidly eliminated combination partners.