julilili42/papers huggingface dataset:
A new tritylodontid from the Upper Jurassic Shishugou Formation of the Junggar Basin (Xinjiang, NW China)
2004-09-10

Abstract A new tritylodontid cynodont, Bienotheroides ultimus sp. nov., is described from the Upper Jurassic Shishugou Formation of Jiangjunmiao in the northeastern Junggar Basin of Xinjiang (NW China). The type consists of a partial skeleton, including teeth, a partial skull, and a considerable portion of the postcranium. It is identifiable as Bienotheroides because of the structure of the upper molars and the characteristically deep zygomatic arch. It is distinguished from Bienotheroides zigongensis from the Middle Jurassic of the Junggar Basin particularly by characters of the forelimb, including a humerus that shows little torsion of the proximal and distal ends. Bienotheroides ultimus is the last of the Chinese tritylodontids known so far, and apart from Xenocretosuchus from the Lower Cretaceous of Russia and an unnamed form from the Lower Cretaceous of Japan, it is the last non-mammalian therapsid known in the entire fossil record.
<title>Computer modeling of the processes of laser thermal keratoplasty</title>
2004-09-10

The model of corneal biotissue layers and their values of optical parameters are presented. The model of the processes involved in laser thermal keratoplasty of eye biotissues is proposed, and the results of computer modeling are presented. Characteristics of optical and thermal processes and the influence of parameters of radiation and biotissues on the results of laser action are studied. The results of numerical simulations demonstrate the possibility of heating of the region in corneal stroma by a converging beam of laser radiation with a sufficient parameters.
Induction of Nuclear Factor–κB and c‐Jun/Activator Protein–1 via Toll‐Like Receptor 2 in Macrophages by Antimycotic‐TreatedCandida albicans
2004-09-13

We examined the role of Toll-like receptors (TLRs) by using TLR2-deficient (TLR2(-/-)), TLR4-defective (TLR4(d/d)), and double-knockout murine macrophages and human embryonic kidney (HEK) 293 cells transfected with human TLR2 or TLR4 expression plasmids after stimulation with different preparations of the human pathogenic fungus Candida albicans. Compared with wild-type macrophages, TLR2(-/-) and TLR4(d/d) macrophages had impaired recognition of viable C. albicans, whereas antimycotic (AM)-treated C. albicans solely used TLR2 in a TLR4- and interferon- gamma -independent manner. In human HEK293 cells, AM-treated C. albicans elicited mainly TLR2-dependent activation. The differences in responsiveness to viable C. albicans, compared with C. albicans treated with cytoplasmic membrane-interacting AMs, suggest specific recognition of different pathogen-associated patterns by TLRs in innate antifungal responses. Our analyses of signal transduction after stimulation of wild-type macrophages with AM-treated C. albicans demonstrated involvement of the transcription factors nuclear factor- kappa B and c-Jun/activator protein-1 and of the mitogen-activated protein kinases p38, extracellular-related kinase, and c-Jun NH(2)-terminal kinase.
Visualization of protein interactions in living plant cells using bimolecular fluorescence complementation
2004-09-14

Summary Dynamic networks of protein–protein interactions regulate numerous cellular processes and determine the ability to respond appropriately to environmental stimuli. However, the investigation of protein complex formation in living plant cells by methods such as fluorescence resonance energy transfer has remained experimentally difficult, time consuming and requires sophisticated technical equipment. Here, we report the implementation of a bimolecular fluorescence complementation (BiFC) technique for visualization of protein–protein interactions in plant cells. This approach relies on the formation of a fluorescent complex by two non‐fluorescent fragments of the yellow fluorescent protein brought together by association of interacting proteins fused to these fragments ( Hu et al. , 2002 ). To enable BiFC analyses in plant cells, we generated different complementary sets of expression vectors, which enable protein interaction studies in transiently or stably transformed cells. These vectors were used to investigate and visualize homodimerization of the basic leucine zipper (bZIP) transcription factor bZIP63 and the zinc finger protein lesion simulating disease 1 (LSD1) from Arabidopsis as well as the dimer formation of the tobacco 14‐3‐3 protein T14‐3c. The interaction analyses of these model proteins established the feasibility of BiFC analyses for efficient visualization of structurally distinct proteins in different cellular compartments. Our investigations revealed a remarkable signal fluorescence intensity of interacting protein complexes as well as a high reproducibility and technical simplicity of the method in different plant systems. Consequently, the BiFC approach should significantly facilitate the visualization of the subcellular sites of protein interactions under conditions that closely reflect the normal physiological environment.
Transition‐Metal‐Mediated Synthesis of Novel Carbocyclic Nucleoside Analogues with Antitumoral Activity
2004-09-14

Abstract A diversity‐oriented, enantioselective synthesis of new (monoprotected) carbocyclic nucleoside analogues (CNAs) with the nucleobase attached to a 3‐hydroxymethyl‐4‐trialkylsilyloxymethylcyclopent‐2‐en‐1‐yl scaffold was developed. As a key intermediate, racemic (5 SR ,8 RS )‐8‐allyloxy‐2‐trimethylsilyl‐7‐oxa‐bicyclo[3.3.0]‐oct‐1‐en‐3‐one was prepared from 1,1‐diallyloxy‐3‐trimethylsilyl‐2‐propyne in a cobalt‐mediated Pauson–Khand reaction. The enantiomerically pure material was obtained through efficient kinetic resolution (selectivity factor s ≥40 at −78 °C) by means of an oxazaborolidine‐catalyzed borane reduction (CBS reduction) with catecholborane. The absolute configuration of the resolved products was determined by CD spectroscopy, Mosher ester analysis, and chemical correlation. Subsequent steps involve diastereoselective ketone reduction and fully regio‐ and diastereoselective introduction of the nucleobase through Pd 0 ‐catalyzed allylic substitution. The generality of the method was demonstrated by preparation of CNAs in both enantiomeric series with all five natural nucleobases, as well as 5‐bromouracil, 5‐fluorouracil, and 6‐chloropurine. Screening of the various compounds in a cytotoxicity assay with BJAB and ALL tumor cell lines revealed that some of the compounds possess pronounced antitumoral properties (LD 50 values down to 9 μ M , as determined by lactate dehydrogenase release after 48 h). By measuring DNA fragmentation, it could be shown that the activity results from induction of apoptosis.
CD25 Indicates the Neoplastic Phenotype of Mast Cells
2004-09-15

The diagnosis of systemic mastocytosis (SM) is based primarily on the histologic and immunohistochemical evaluation of a bone marrow trephine biopsy specimen. Although mast cell (MC) specific antigens like tryptase and chymase are detectable in routinely processed tissue, no immunohistochemical markers that can be used to discriminate between normal and neoplastic MCs are yet available. We have investigated the diagnostic value of an antibody against CD25 for the immunohistochemical detection of MCs in bone marrow sections in 73 patients with SM and 75 control cases (reactive marrow, n = 54; myelogenous neoplasms, n = 21) and correlated the results with the presence of c-kit mutations. While MCs in almost all patients with SM (72 of 73) expressed CD25, none of the control samples contained CD25-positive MCs. Irrespective of the SM subtype, most of neoplastic MCs expressed CD25. In 3 patients with advanced MC disease, pure populations of neoplastic MCs were obtained and found to express CD25 mRNA by RT-PCR analysis. In addition, all patients with CD25-positive MCs contained c-kit mutations, while all control cases exhibited wild type c-kit. CD25 therefore appears to be a reliable immunohistochemical marker for the discrimination of neoplastic from normal/reactive MCs, with potential as a diagnostic tool in SM.
Frontal gamma-band activity in magnetoencephalogram during auditory oddball processing
2004-09-15

Previous studies have demonstrated induced gamma-band activity (GBA) over posterior temporo-parietal and inferior frontal cortex during auditory spatial vs pattern mismatch processing, respectively. Here we investigated magnetoencephalographic oscillatory responses during an active auditory pattern oddball task. Fourteen subjects were instructed to detect pairs of deviating animal vocalizations in a sequence of standard sounds. The comparison of targets with standards revealed differences in oscillatory activity >80 Hz 200–300 ms after stimulus onset. GBA was increased over left inferior frontal cortex, replicating previous results of putative auditory ventral stream activation during passive pattern deviance processing. Additional GBA enhancements over superior frontal cortex were specific to active target detection. They probably reflected executive networks involved in memory maintenance and decision making.
Effect of magnetic field in superconductor hybrid interfaces
2004-09-15

We examine the effect of the magnetic field on the proximity effect in\\nnanostructures, self consistently using the Bogoliubov-deGennes formalism\\nwithin the two dimensional extended Hubbard model. We calculate the local\\ndensity of states and the pair amplitude. We study several nanostructures:\\nsuperconductor - two dimensional electron gas, superconductor - ferromagnet. In\\nthese structures the magnetic field can be considered as a modulation parameter\\nfor the proximity effect.\\n
Fabrication and evaluation of efficient light emitters comprising nanocluster-rich SiO 2 layers
2004-09-15

We have demonstrated the feasibility of obtaining intense blue-to-violet electroluminescence (EL) from silicon-based light-emitting structures at room temperature (RT), in line with the need for efficient and inexpensive light sources whose production is compatible with existing silicon device technology. Ion-beam synthesis (IBS) and standard silicon processing have been used to fabricate light-emitting diodes whose active medium is a layer of thermal SiO<sub>2</sub> containing germanium nanocrystals. Extensive research has been carried out in three main directions: optimization of the fabrication process, improvement in the device lifetime, and elucidation of the underlying mechanisms of light emission and charge injection/charge transport. This research effort has resulted in the establishment of a set of optimum conditions for the formation of improved-quality Si-based light emitters. It has been shown that the use of plasma treatement is helpful in increasing device lifetime. Issues related to the nature and the excitation of the light-emitting centers have been considered. Finally, the utility of such light-emitting devices in the development of integrated optoelectronic devices as well as Lab-on-a-Chip, microarray and sensor systems has been outlined.
Mini‐review: Transendothelial migration of leukocytes: through the front door or around the side of the house?
2004-09-16

Abstract Leukocyte adhesion to the endothelial cells lining the vessel wall and the subsequent migration of the leukocytes into the underlying tissue are key elements of both innate and adaptive immunity. Leukocyte extravasation is generally believed to take place through small gaps at intercellular endothelial cell junctions – the para cellular route. This view has, however, been repeatedly challenged by morphological studies demonstrating leukocyte migration through the endothelial cells themselves – the trans cellular pathway. On the basis of the current experimental evidence, we propose consideration that both pathways are equally possible for a leukocyte's journey from the apical surface of the endothelium to its basal side.
Cyanopeptolin 963A, a Chymotrypsin Inhibitor of Microcystis PCC 7806
2004-09-16

A new depsipeptide, cyanopeptolin 963 A (1), was isolated from an axenic strain of the toxic freshwater cyanobacterium Microcystis PCC 7806. The structure of this compound was elucidated by chemical and spectroscopic analyses, including high-resolution ESI-FTICR-MS, 2-D NMR, and GC-MS of the hydrolysate. The major structural difference compared to previously characterized cyanopeptolins of this strain is the replacement of the basic amino acid in position 3 by L-tyrosine. Compound 1 displayed inhibitory activity against chymotrypsin with an IC50 value of 0.9 microM.
In-Medium IsovectorπNAmplitude from Low-Energy Pion Scattering
2004-09-16

Differential cross sections for elastic scattering of 21.5 MeV positive and negative pions by Si, Ca, Ni, and Zr have been measured as part of a study of the pion-nucleus potential across the threshold. The "anomalous" repulsion in the s-wave term was observed, as is the case with pionic atoms. The extra repulsion can be accounted for by a chiral-motivated model where the pion decay constant is modified in the medium. Unlike in pionic atoms, the anomaly cannot be removed by merely introducing an empirical on-shell energy dependence.
Influence of low power cm-/mm-microwaves on cardiovascular function
2004-09-17

The present study has been designed to investigate physiological effects of short (15 min) exposure to low level energy microwaves (< 10 microW cm(-2)). To this end heart rate, PQ, QS and ST (electrocardiography), respiration (conductive stretch band around the thorax), skin temperature (thermocouple), skin conductance (Ag/AgCl electrodes), systolic and diastolic blood pressure (automatic cuff) were continuously recorded in a group of 50 test persons before, during and after a 15 min exposure to 3 microW cm(-2) high frequency (77 GHz) microwaves. After an equilibration period of 30 min the first group of test persons and after additional 30 min the second group of test persons were exposed. The study has been performed in a strict double blind design. While significant effects on the measured parameters were observed depending on time ('calming' effect), no significant difference was observed between exposure and sham exposure to microwaves. In view of the small scatter of the data the present study rules out physiologically relevant effects of low level energy on the autonomic nervous system and cardiovascular function.
An AIF orthologue regulates apoptosis in yeast
2004-09-20

Apoptosis-inducing factor (AIF), a key regulator of cell death, is essential for normal mammalian development and participates in pathological apoptosis. The proapoptotic nature of AIF and its mode of action are controversial. Here, we show that the yeast AIF homologue Ynr074cp controls yeast apoptosis. Similar to mammalian AIF, Ynr074cp is located in mitochondria and translocates to the nucleus of yeast cells in response to apoptotic stimuli. Purified Ynr074cp degrades yeast nuclei and plasmid DNA. YNR074C disruption rescues yeast cells from oxygen stress and delays age-induced apoptosis. Conversely, overexpression of Ynr074cp strongly stimulates apoptotic cell death induced by hydrogen peroxide and this effect is attenuated by disruption of cyclophilin A or the yeast caspase YCA1. We conclude that Ynr074cp is a cell death effector in yeast and rename it AIF-1 (Aif1p, gene AIF1).
Superconducting quantum interference devices: State of the art and applications
2004-09-20

Superconducting quantum interference devices (SQUIDs) are sensitive detectors of magnetic flux. A SQUID consists of a superconducting loop interrupted by either one or two Josephson junctions for the RF or dc SQUID, respectively. Low transition temperature (T/sub c/) SQUIDs are fabricated from thin films of niobium. Immersed in liquid helium at 4.2 K, their flux noise is typically 10/sup -6//spl Phi//sub 0/ Hz/sup -1/2/, where /spl Phi//sub 0//spl equiv/h/2e is the flux quantum. High-T/sub c/ SQUIDs are fabricated from thin films of YBa/sub 2/Cu/sub 3/O/sub 7-x/, and are generally operated in liquid nitrogen at 77 K. Inductively coupled to an appropriate input circuit, SQUIDs measure a variety of physical quantities, including magnetic field, magnetic field gradient, voltage, and magnetic susceptibility. Systems are available for detecting magnetic signals from the brain, measuring the magnetic susceptibility of materials and geophysical core samples, magnetocardiography and nondestructive evaluation. SQUID "microscopes" detect magnetic nanoparticles attached to pathogens in an immunoassay technique and locate faults in semiconductor packages. A SQUID amplifier with an integrated resonant microstrip is within a factor of two of the quantum limit at 0.5 GHz and will be used in a search for axions. High-resolution magnetic resonance images are obtained at frequencies of a few kilohertz with a SQUID-based detector.
An n- to p-type conductivity transition induced by oxygen adsorption on α-Fe2O3
2004-09-20

The simultaneous measurements of conductance and work function changes induced by gaseous ambient have been performed on α-Fe2O3 thick film polycrystalline samples kept at 280 °C and exposed to different gaseous atmospheres. The switching from n- to p-type conductivity on α-Fe2O3 is shown to have an electronic origin, which is due to the oxygen adsorption and formation of a surface inversion layer and, therefore, to the inversion of the surface conduction type. The modeling of the n–p switching is described in terms of conductance dependence on the band bending induced by gaseous ambient.
Thermoradiotherapy of the chest wall in locally advanced or recurrent breast cancer with marginal resection
2004-09-20

The results concerning local tumour control and overall survival in these high-risk patients are promising, especially for TRT for the treatment of local recurrences. A longer follow-up is needed to estimate late toxicity.
Value of the clinical history for different users of dermoscopy compared with results of digital image analysis
2004-09-21

ABSTRACT Background The clinical history of a given pigmented lesion could influence the therapeutic decision. Teledermatology and automated image analysis also hold great potential for revolutionizing dermatology services. Aim The aim of this retrospective study was to evaluate the diagnostic accuracy of users with different experiences in dermoscopy with and without information about patients and their history compared with classification by an automated analysing system. Setting One hundred and fifty‐seven dermoscopic images of pigmented lesions, taken and proved by histopathology at the Pigmented Lesions Clinic of the Department of Dermatology of the University Tuebingen, Germany, were included. Methods All images were viewed by three investigators with different experience: excellent (A), average (B) and beginner (C). In the first dermoscopic classification, no information was available. After 3 months the same images were once more classified by the three investigators, now with the information about the patients and their history. The melanocytic lesions were tested by the Tuebinger Mole Analyser. Results For user A the sensitivity, specificity and diagnostic accuracy revealed no improvement on including the history (81.3% to 84.4%, 94.6% to 92.3% and 92.0% to 90.7%), whereas user B clearly improved his results (75.0% to 87.5%, 76.9% to 88.5% and 76.5% to 88.3%). No change in the sensitivity was seen by user C (84.4%), but there was a clear improvement in the specificity (69.2% to 87.7%) and diagnostic accuracy (72.2% to 87.0%). Using the computer algorithm, a sensitivity of 100%, a specificity of 76.9% and a diagnostic accuracy of 81.9% were achieved. Conclusions The study revealed results relevant to the use of dermoscopy: (1) continuing dermoscopic education influences the diagnostic accuracy; (2) the history is helpful for averaged users and beginners in dermoscopy; (3) digital image analysis has the highest sensitivity, but a lower specificity compared to the clinicians; and (4) digital dermoscopy could be used for store‐and‐forward systems in teledermoscopy.
An astronomical search for evidence of new physics: Limits on gravity-induced birefringence from the magnetic white dwarf RE J0317-853
2004-09-21

The coupling of the electromagnetic field directly with gravitational gauge\\nfields leads to new physical effects that can be tested using astronomical\\ndata. Here we consider a particular case for closer scrutiny, a specific\\nnonminimal coupling of torsion to electromagnetism, which enters into a\\nmetric-affine geometry of space-time. We show that under the assumption of this\\nnonminimal coupling, spacetime is birefringent in the presence of such a\\ngravitational field. This leads to the depolarization of light emitted from\\nextended astrophysical sources. We use polarimetric data of the magnetic white\\ndwarf to set strong constraints on the essential coupling\\nconstant for this effect, giving .\\n
Multi-frequency study of extragalactic supernova remnants and HII regions
2004-09-21

We present a multi-frequency study of supernova remnants (SNRs) and HII regions in the nearby Sculptor Group Sd galaxy NGC 300, based on new ATCA observations at the wavelengths of 13 and 20 cm, XMM-Newton observations, newly-processed ROSAT (PSPC/HRI; [CITE]) and VLA (20/6 cm) images of this galaxy. We have investigated the physical properties at the X-ray and radio wavelengths of the 28 optical SNRs found by [CITE] and have expanded on the multi-wavelength work by [CITE] on this same galaxy. From a total of 54 radio sources and 11 X-ray sources, we report 18 SNRs and three (3) SNR candidates (classified by spectral index alone) in NGC 300. Five of these 18 SNRs are associated with reported optical SNRs and three have X-ray counterparts. An additional 12 radio SNRs are seen in the [CITE] [S II] images. We also investigate the luminosity function of our SNRs. Three background radio sources are confirmed and 12 other sources could represent additional background objects. Twenty two radio correlations with OB associations within NGC 300 correspond to either HII regions or SNRs making them a good tracer of SNRs near star-forming regions. Additionally, two radio sources coincide with potential globular clusters of NGC 300 reported by [CITE].
Do child psychiatrists in Germany diagnose bipolar disorders in children and adolescents? Results from a survey
2004-09-21

Objectives: There is a controversy about the prevalence of childhood bipolar disorders (BD). Based on discrepant results, we studied if German psychiatrists in outpatient settings diagnose BD in children and adolescents at all, and if there are possible correlates of the diagnoses of pediatric BD. We also asked how often typical manic symptoms (e.g. elated mood) are actually seen in attention deficit hyperactivity disorder (ADHD) patients. Methods: Provided by the medical register we had a complete list of all 251 psychiatrists in the area. Using a questionnaire we asked if and how often they diagnose BD among children and adolescents and how often they observe manic‐like symptoms in children with ADHD (response rate 61%). Results: While 63% of all psychiatrists have diagnosed BD in adolescents, only 7.8% did so in children. Age and therapeutic approach of the psychiatrists were associated with the likelihood of having diagnosed BD in children. Furthermore some typical bipolar symptoms were also present in ADHD patients. Conclusions: Our study only relied on self‐reports of the psychiatrists about the diagnoses and number of cases, but BD in children seems to be rarely diagnosed in outpatient settings in Germany. The design of our study, however, cannot resolve the questions what the reasons are for this low rate of BD diagnoses, e.g. misdiagnoses, overlooking comorbidity or referral strategies. Epidemiological studies are needed and should consider multiple follow‐ups.