julilili42/papers huggingface dataset:
Molecular Imaging of Vulnerable Atherosclerotic Plaques
2005-12-19

Despite primary and secondary prevention, serious cardiovascular events such as unstable angina or myocardial infarction still account for a third of all deaths worldwide. Therefore, identifying individual patients with vulnerable plaques at high risk for plaque rupture is a central challenge in clinical medicine. Several noninvasive techniques, such as magnetic resonance imaging, multislice computed tomography and electron beam tomography are currently being tested for their ability to identify such patients by morphological criteria. In contrast, noninvasive scintigraphic techniques use radiolabeled molecules to detect functional aspects in atherosclerotic plaques by visualizing its biologic activity. Based upon knowledge regarding the pathophysiology of atherosclerosis, various studies - in vitro, in vivo and first clinical trials - have used different tracers for plaque imaging studies, including radioactive labeled lipoproteins, components of the coagulation system, cytokines, mediators of the metalloproteinase system, cell adhesion receptors and even whole cells.
On Electromagnetic Thirring Problems
2005-12-19

The standard Thirring problem describes the (non–local) influence of rotating masses on the inertial properties of space–time, especially the so–called dragging of inertial frames inside a rotating mass shell relative to the asymptotic frames. It is then a natural question to ask whether and how properties other than inertial ones are also influenced by rotating masses, and the first (non–inertial and non–gravitational) properties which come here to one’s mind, are surely electromagnetic phenomena. Indeed there exists a whole series of papers [1, 2, 3, 4, 5] on models where a charge sits inside a slowly rotating mass shell (mass M, radius R), and where the rotationally induced magnetic field is calculated and discussed, typically for small ratios M/R and/or An especially remarkable but confusing fact is that Cohen’s results [2] are in complete agreement with Machian expectations whereas Ehlers and Rindler [4] interpret their results to be “in fact Mach–negative or, at best, Mach– neutral”. We examine a class of models consisting of two spherical shells of radii and the first one carrying a nearly arbitrary charge but no rest mass, the second one being nearly arbitrary massive but electrically neutral. The only restriction on the parameters is that the systems should be free of singularities and horizons. To these shells we apply small but otherwise arbitrary “stirring” angular velocities and
Generalized Quantifiers
2005-12-20

Abstract Generalized quantifiers in logic are those quantifiers which go beyond the traditional first order quantifiers ∃, ∀. Quantifiers in natural language semantics are the denotations of determiners; generalized quantifiers are the denotations of noun phrases (NPs).
Enhanced programmed cell death of iron‐deficient erythrocytes
2005-12-21

ABSTRACT Exposure of erythrocytes to osmotic shock, oxidative stress, and energy depletion activates Cl – sensitive and Ca 2+ ‐permeable cation channels. Subsequent Ca 2+ entry triggers eryptosis, characterized by erythrocyte shrinkage, membrane blebbing, and phosphatidylserine exposure all features typical for apoptotic death of nucleated cells. Erythrocytes exposing phosphatidylserine are recognized, bound, engulfed, and degraded by macrophages. Eryptosis thus fosters clearance of affected erythrocytes from circulating blood. Iron deficiency leads to anemia, in part by decreasing erythrocyte life span. In this study, phosphatidylserine exposure, cell size, and cytosolic Ca 2+ were measured by FACS analysis of annexin‐V binding, forward scatter, and Fluo‐3 fluorescence, respectively. Erythrocytes from mice on control diet were compared with erythrocytes from mice exposed 10 weeks to iron‐deficient diet. Iron deficiency significantly ( P &lt;0.001) enhanced erythrocyte annexin‐V binding (from 2.4 to 3.7%), decreased forward scatter (from 544 to 393), and increased cytosolic Ca 2+ concentration. 45 Ca 2+ flux measurements and patch clamp experiments revealed enhanced Ca 2+ uptake (by 2.3‐fold) and cation channel activity. The half‐life of fluorescence‐labeled, iron‐deficient, or Ca 2+ ‐loaded erythrocytes was significantly reduced compared with control erythrocytes. Thus, the experiments reveal a novel mechanism triggered by iron deficiency, which presumably contributes to accelerated clearance of erythrocytes in iron deficiency anemia.
Spatial neglect—a vestibular disorder?
2005-12-21

The phenomenon of spatial neglect after right brain damage greatly helps our understanding of the normal mechanisms of directing and maintaining spatial attention, of spatial orientation, and the characteristics of neural representation of space. The intriguing symptom is a spontaneous orientation bias towards the right leading to neglect of objects or persons on the left. Interestingly, we observe similar symptoms namely a spontaneous bias of eyes and head along the horizontal dimension of space in patients with unilateral vestibular dysfunction. Further similarities concern anatomical findings. Both spatial neglect and vestibular processing at cortical level show dominance in the right hemisphere and involve common brain areas. Lesion studies in human and monkey, electrical and transcranial magnetic stimulation, as well as functional imaging results have revealed the superior temporal cortex, insula and the temporo-parietal junction to be substantial parts of the multisensory (vestibular) system as well as to be affected in spatial neglect. We argue that these structures are not strictly 'vestibular' but rather have a multimodal character representing a significant site for the neural transformation of converging vestibular, auditory, neck proprioceptive and visual input into higher order spatial representations. Neurons of these regions provide us with redundant information about the position and motion of our body in space. They seem to play an essential role in adjusting body position relative to external space. This view may initiate further development of those strategies to treat spatial neglect that use routes to rehabilitation based on specific manipulations of sensory input feeding into this system.
Senescence‐specific regulation of catalases in Arabidopsis thaliana (L.) Heynh
2005-12-22

ABSTRACT Oxygen free radicals are thought to play an essential role in senescence, especially those derived from peroxisomes. Therefore, the activities of different isoforms of the peroxisomal hydrogen peroxide (H 2 O 2 )‐scavenging enzyme catalase (CAT) were analysed during senescence of Arabidopsis . CAT2 activity decreased with bolting time parallel with cytosolic ascorbate peroxidase 1 (APX1) activity before loss of chlorophyll could be measured. At the same time point, the H 2 O 2 content increased. Subsequently, the stress‐inducible CAT3 isoform was activated and APX1 activity was recovered, accompanied by a decline of the H 2 O 2 content. In very late stages, low activities of the seed‐specific CAT1 became detectable in leaves, but H 2 O 2 increased again. Further analyses of CAT expression by promoter : β ‐glucuronidase ( GUS ) fusions in transgenic plants revealed a vasculature‐specific CAT3 expression, whereas CAT2 expression turned out to be specific for photosynthetic active tissues. CAT2 expression is down‐regulated during leaf senescence, while CAT3 expression is induced with age and corresponds to an accumulation of H 2 O 2 in the vascular bundles. CAT2 down‐regulation on the transcriptional level appears as the initial step in creating the H 2 O 2 peak during bolting time, while the decrease in APX1 activity might only be a secondary and amplifying effect.
Effects on MRI due to altered rf polarization near conductive implants or instruments
2005-12-22

In magnetic resonance imaging near metal parts variations in radio frequency (rf)‐amplitude and of receive sensitivity must be considered. For loop structures, e.g., vascular stents, produces rf eddy currents in accordance to Faraday's law; the ‐related electrical rf field injects directly to elongated structures (e.g., wires). Locally, the rf magnetic field (induced ) is superimposed onto the rf field from the transmitter coil, which near the metal can dominate spin excitation. Geometry and arrangement of the parts determine the polarization of . Components parallel to are of special interest. A copper sheet ( , thick) and a long copper wire were examined in a water phantom using the spin‐echo (SE) technique. In addition to rf‐amplitude amplification, rf‐phase shift due to components of could be detected near the metallic objects. Periodic rf‐amplitude instabilities had an amplified effect for phase‐shifted regions. Phase‐encoding artifacts occurred as distinct ghosts or band‐like smearing from affected spin ensembles. SE phase imaging can potentially be used in interventional magnetic resonance imaging for background‐free localization of metallic markers.
4′-Phosphopantetheine Biosynthesis in Archaea
2005-12-22

Coenzyme A as the principal acyl carrier is required for many synthetic and degradative reactions in intermediary metabolism. It is synthesized in five steps from pantothenate, and recently the CoaA biosynthetic genes of eubacteria, plants, and human were all identified and cloned. In most bacteria, the so-called Dfp proteins catalyze the synthesis of the coenzyme A precursor 4'-phosphopantetheine. Dfp proteins are bifunctional enzymes catalyzing the synthesis of 4'-phosphopantothenoylcysteine (CoaB activity) and its decarboxylation to 4'-phosphopantetheine (CoaC activity). Here, we demonstrate the functional characterization of the CoaB and CoaC domains of an archaebacterial Dfp protein. Both domains of the Methanocaldococcus jannaschii Dfp protein were purified as His tag proteins, and their enzymatic activities were then identified and characterized by site-directed mutagenesis. Although the nucleotide binding motif II of the CoaB domain resembles that of eukaryotic enzymes, Methanocaldococcus CoaB is a CTP- and not an ATP-dependent enzyme, as shown by detection of the 4'-phosphopantothenoyl-CMP intermediate. The proposed 4'-phosphopantothenoylcysteine binding clamp of the Methanocaldococcus CoaC activity differs significantly from those of other characterized CoaC proteins. In particular, the active site cysteine residue, which otherwise is involved in the reduction of an aminoenethiol reaction intermediate, is not present. Moreover, the conserved Asn residue of the PXMNXXMW motif, which contacts the carboxyl group of 4'-phosphopantothenoylcysteine, is exchanged for His.
Programming of Time-to-Peak Force for Brief Isometric Force Pulses: Effects on Reaction Time
2005-12-22

According to the parallel force unit model (PFUM) the programming of an isometric force pulse requires the specification of the number of force units and force unit duration. The programming of a force pulse with minimal time-to-peak force is an exception, however, as force unit duration is limited by the minimal possible value, which should be easier to adjust than larger force unit durations. Therefore, the duration of the programming process should be shorter for these force pulses and hence should result in shorter reaction time (RT). Four experiments assessed this prediction using a response precueing procedure. In each experiment the participants produced isometric flexions with their left or right index finger, and time-to-peak force was manipulated within a block. The results are consistent with the predictions of PFUM. The results, however, are at variance with alternative accounts which assume that RT depends primarily on response duration or rate of force production.
Hardware Oriented Algorithms for Rendering Order-Independent Transparency
2005-12-22

Journal Article Hardware Oriented Algorithms for Rendering Order-Independent Transparency Get access M. Amor, M. Amor *Corresponding author: margamor@udc.es Search for other works by this author on: Oxford Academic Google Scholar M. Bóo, M. Bóo Search for other works by this author on: Oxford Academic Google Scholar E. J. Padrón, E. J. Padrón Search for other works by this author on: Oxford Academic Google Scholar D. Bartz D. Bartz Search for other works by this author on: Oxford Academic Google Scholar The Computer Journal, Volume 49, Issue 2, March 2006, Pages 201–210, https://doi.org/10.1093/comjnl/bxh159 Published: 22 December 2005 Article history Received: 12 May 2004 Revision received: 18 October 2005 Published: 22 December 2005
Adherent Platelets Recruit and Induce Differentiation of Murine Embryonic Endothelial Progenitor Cells to Mature Endothelial Cells In Vitro
2005-12-23

The homing and differentiation mechanisms of endothelial progenitor cells (EPCs) at sites of vascular lesions are unclear. To investigate whether platelets play a role in the recruitment and differentiation of EPCs, we made use of a robust mouse embryonic EPC (eEPC) line that reliably differentiates to a mature endothelial phenotype. We found that platelets stimulate chemotaxis and migration of these murine eEPCs. Further, the substantial adhesion of murine eEPCs on immobilized platelets that occurs under dynamic flow conditions is inhibited by neutralizing anti–P-selectin glycoprotein ligand-1 and anti–VLA-4 (β 1 -integrin) monoclonal antibodies but not by anti-CD11b (a M -integrin; macrophage antigen-1). Coincubation of murine eEPCs with platelets for 5 days induced differentiation of EPCs to mature endothelial cells as verified by positive von Willebrand factor immunofluorescence and detection of Weibel Palade bodies through electron microscopy. We conclude that platelets may play a critical part in the capture and subsequent differentiation of murine eEPCs at sites of vascular lesions, revealing a possible new role of platelets in neoendothelization after vascular injury.
[Quantification of human DNA from forensic samples via real time PCR by the help of a telomerase assay].
2005-12-23

Quantitative data concerning the content of human DNA and the effect of PCR inhibitors in a sample would provide very important information within a forensic DNA analysis. With the help of real-time PCR it is possible to test DNA samples for these influencing factors. However, the amplified DNA segments detected by means of usual TaqMan DNA probes are longer than most of the short tandem repeats to be investigated. Because of possible DNA degradation, a DNA probe located in the human telomerase transcriptase gene was successfully tested on forensic samples in the present study. Its amplified DNA segment is only 94 bases in length and, thus, shorter than the short tandem repeats. Therefore, it seems perfectly suited for the examination of degraded DNA. With the telomerase probe it was possible to obtain accurate results of the influence factors mentioned above. Based on the findings of this examination and on a case example, in which the poorly preserved remains of a baby were subjected to paternity testing, the possible uses of the telomerase assay are discussed.
Transforming Growth Factor-&#946;: A Molecular Target for the Future Therapy of Glioblastoma
2005-12-27

The median survival of patients with glioblastoma treated by surgery, radiotherapy and chemotherapy is in the range of 12 months. These limits in the efficacy of current treatment modalities call for the development of novel therapeutic approaches targeting the specific biological features of this type of cancer. Glioblastomas are a rich source of immunosuppressive molecules which may interfere with immune recognition and rejection as well as clinical strategies of active immunotherapy. The most prominent glioblastoma-associated immunosuppressant is the cytokine, transforming growth factor (TGF)-beta, a multifunctional cytokine which not only interferes with multiple steps of afferent and efferent immune responses, but also stimulates migration, invasion and angiogenesis. The complex regulation of TGF-beta bioavailability includes its synthesis as a proprotein, proteolytic processing by furin-like proteases, assembly in a latent complex, and finally liberation from latency by multiple effector mechanisms, a process collectively referred to as activation. Several in vitro paradigms and rodent glioma models have been used to demonstrate that the antagonism of TGF-beta holds promise for the treatment of glioblastoma, employing antisense strategies, inhibition of pro-TGF-beta processing, scavenging TGF-beta by decorin, or blocking TGF-beta activity by specific TGF-beta receptor (TGF-betaR) I kinase antagonists. Moreover, the local application of TGF-beta(2) antisense oligonucleotides is currently evaluated in a randomized clinical trial for recurrent malignant glioma. In summary, we propose that TGF-beta-antagonistic treatment strategies are among the most promising of the current innovative approaches for glioblastoma, particularly in conjunction with novel approaches of cellular immunotherapy and vaccination.
Epithelial-specific transcription factor ESE-3 is involved in the development of monocyte-derived DCs
2005-12-27

Abstract Dendritic cells (DCs) are recognized as the most potent antigen-presenting cells of the immune system with the unique ability to initiate and maintain primary immune responses. In order to better characterize the functional and phenotypic features of DCs, a subtractive cDNA library to identify differentially expressed genes in monocyte-derived DCs (MDCs) was constructed. Using this approach, we found that the epithelial transcription factor ESE-3, which was previously shown to be exclusively expressed in cells of epithelial origin, is differentially expressed in MDCs. This was further confirmed by reverse transcriptase–polymerase chain reaction (RT-PCR) and Western blot analyses. The expression of ESE-3 is up-regulated upon maturation of MDCs and inhibited by treating the cells with IL-10 or IFN-γ. Knockdown experiments using siRNA suggest that ESE-3 plays an important role during MDC development. Our results might help to improve the phenotypic characterization of DCs and lead to a better understanding of the cellular mechanisms involved in antigen presentation and T-cell stimulation.
Decays of tensor mesons and the tensor glueball in an effective field approach
2005-12-28

The strong and electromagnetic decays of the ground-state tensor mesons are studied in an effective field approach. A fit to the well-known experimental data is performed. The decay ratios of the tensor glueball are evaluated and possible candidates are discussed.
Momentum, density, and isospin dependence of symmetric and asymmetric nuclear matter properties
2005-12-29

Properties of symmetric and asymmetric nuclear matter have been investigated\\nin the relativistic Dirac-Brueckner-Hartree-Fock approach based on projection\\ntechniques using the Bonn A potential. The momentum, density, and isospin\\ndependence of the optical potentials and nucleon effective masses are studied.\\nIt turns out that the isovector optical potential depends sensitively on\\ndensity and momentum, but is almost insensitive to the isospin asymmetry.\\nFurthermore, the Dirac mass and the nonrelativistic mass \\nwhich parametrizes the energy dependence of the single particle spectrum, are\\nboth determined from relativistic Dirac-Brueckner-Hartree-Fock calculations.\\nThe nonrelativistic mass shows a characteristic peak structure at momenta\\nslightly above the Fermi momentum . The relativistic Dirac mass shows a\\nproton-neutron mass splitting of in isospin asymmetric\\nnuclear matter. However, the nonrelativistic mass has a reversed mass splitting\\n which is in agreement with the results from\\nnonrelativistic calculations.\\n
Modulation of excitability as an early change leading to structural adaptation in the motor cortex
2005-12-29

Abstract The excitability of the motor cortex is a function of single cell excitability, synaptic strength, and the balance between excitatory cells and inhibitory cells. Sustained periods of sensory stimulation enhance the excitability in the motor cortex. This adaptation, which represents an early change in cortical network function effective in motor learning and recovery from a motor deficit, is followed by longer‐lasting changes, such as modifications in cortical somatotopy, and by structural plasticity. Interventions aiming at increasing excitability also positively affect learning processes. Recent studies highlight that the cerebellum, especially the interpositus nucleus, plays a key function in the adaptation of the motor cortex to repeated trains of peripheral stimulation. Interpositus neurons, which receive inputs from the sensorimotor cortex and the spinal cord, are involved in somesthetic reflex behaviors and assist the cerebral cortex in transforming sensory signals to motor‐oriented commands by acting via the cerebello‐thalamo‐cortical projections. Moreover, climbing fibers originating in the inferior olivary complex and innervating the nucleus interpositus mediate highly integrated sensorimotor information derived from spinal modules. The intermediate cerebellum allows the motor cortex to tune the gain of polysynaptic responses originating from the spinal cord after repetitive trains of peripheral stimulation, allowing an online calibration of cutaneo‐muscular responses. © 2005 Wiley‐Liss, Inc.
Substituted Isoxazoles as Potent Inhibitors of p38 MAP Kinase
2005-12-29

Abstract In a continuous effort to develop improved p38 MAP (mitogen‐activated protein) kinase inhibitors, we focused our attention on the suitability of the isoxazole ring as a bioisosteric replacement for the imidazole ring of SB‐203580. 3,4‐ and 4,5‐disubstituted as well as 3,4,5‐trisubstituted isoxazole derivatives were synthesized. These compounds were tested in an in vitro enzyme‐linked immunosorbent assay of isolated p38 MAP kinase and for inhibitory potency against cytochrome P450. Compound 4 a displays a highly promising profile for development as an anti‐inflammatory agent owing to its enhanced suppression of cytokine release, decreased affinity for cytochrome P450 and a twofold decrease in IC 50 toward isolated p38 MAP kinase.
Characters that differ between diploid and haploid honey bee (Apis mellifera) drones.
2005-12-30

Diploid males have long been considered a curiosity contradictory to the haplo-diploid mode of sex determination in the Hymenoptera. In Apis mellifera, 'false' diploid male larvae are eliminated by worker cannibalism immediately after hatching. A 'cannibalism substance' produced by diploid drone larvae to induce worker-assisted suicide has been hypothesized, but it has never been detected. Diploid drones are only removed some hours after hatching. Older larvae are evidently not regarded as 'false males' and instead are regularly nursed by the brood-attending worker bees. As the pheromonal cues presumably are located on the surface of newly hatched bee larvae, we extracted the cuticular secretions and analyzed their chemical composition by gas chromatograph-mass spectrometry (GC-MS) analyses. Larvae were sexed and then reared in vitro for up to three days. The GC-MS pattern that was obtained, with alkanes as the major compounds, was compared between diploid and haploid drone larvae. We also examined some physical parameters of adult drones. There was no difference between diploid and haploid males in their weight at the day of emergence. The diploid adult drones had fewer wing hooks and smaller testes. The sperm DNA content was 0.30 and 0.15 pg per nucleus, giving an exact 2:1 ratio for the gametocytes of diploid and haploid drones, respectively. Vitellogenin was found in the hemolymph of both types of imaginal drones at 5 to 6 days, with a significantly lower titer in the diploids.
Synthesis of the Long Sought After Compound Pentafluoronitrosulfane, SF5NO2
2005-12-30

Endlich erwischt: Bei der Photolyse einer Mischung aus SF5Br und NO2 wird Pentafluornitrosulfan, SF5NO2 (siehe Bild), in Gramm-Mengen erhalten. Gasphasen-Elektronenbeugungsstudien lieferten erste Strukturinformationen und enthüllten die längste bisher beschriebene SVI-N-Bindung (1.903(7) Å).