julilili42/papers huggingface dataset:
Superconducting properties, microstructure and chemical composition of MgB2sheathed materials
2003-06-03

The superconducting properties, the microstructure and the chemical composition of sheathed MgB2 tapes and of one wire, all synthesized by the powder-in-tube method, were investigated. At 4.2 K critical current densities up to 105 A cm−2 (0 T) and 1.5 × 104 A cm−2 (2.5 T) were obtained by transport measurements in the wire and the tapes, respectively.
Insulin-Like Effect of Low-Dose Leptin on Glucose Transport in Langendorff Rat Hearts
2003-06-04

The data suggest that leptin at low physiological concentrations is able to exert a partial insulin like effect on glucose uptake. We speculate that the effect might be mediated by both leptin receptor isoforms. This leptin effect is additive to the effect of insulin and might therefore contribute to the insulin independent basal glucose supply of the heart. It can not be completely excluded that the observed leptin effect on glucose transport is secondary to altered myocardial function.
A Phosphorane as Supported Acylanion Equivalent: Linker Reagents for Smooth and Versatile CC Coupling Reactions
2003-06-05

Smoothly linked: Polymer-supported phosphorane 1 is a C-nucleophile that can be acylated under mild reaction conditions. Diversely substituted α-ketocarbonyl and α-hydroxycarbonyl compounds 2 are furnished following to a reaction sequence including oxidative cleavage of the supported phosphoranes. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2003/z51190_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Synthesis and Nonlinear Optical Properties of Fluorine‐Containing Naphthalocyanines
2003-06-06

Abstract The fluorine‐containing metal naphthalocyanines [F 16 NcGaCl] ( 7 ) and [(F 16 NcGa) 2 O] ( 8 ), which represent the first examples of peripherally fluorine substituted naphthalocyanines, were synthesized, and the nonlinear optical transmission was studied. Peripheral substitution by fluorine atoms enhances the solubility and photostability of the naphthalocyanines. In particular, for the axially μ ‐oxo‐bridged naphthalocyanine dimer 8 , practically no aggregation was observed in organic solvents and it has proved to be an efficient optical limiter when irradiated with laser light pulses at the wavelength of 532 nm, with pulse duration of 5 ns and repetition rate of 20 Hz.
Reconstructing palaeotemperatures using leaf floras – case studies for a comparison of leaf margin analysis and the coexistence approach
2003-06-09

In the past the problems and advantages of the nearest-living-relative (NLR) and leaf physiognomy approaches have been repeatedly discussed and it has been demonstrated that both approaches frequently show broad agreement with each other. However, detailed comparisons of the various methods for accuracy in estimation of palaeoclimate at individual localities are still lacking. Such studies are needed before data obtained from different approaches can be integrated in palaeoclimate maps and models. Moreover, there are some indications that leaf physiognomy and NLR approaches may lead to different results. In this study we applied a physiognomic method based on leaf margin analysis and the coexistence approach, a recent variation of the NLR approach, to two Tertiary palaeofloras (Schrotzburg, Middle Miocene, south Germany; Kleinsaubernitz, Upper Oligocene, east Germany). We demonstrated that both approaches can produce reasonable and consistent results if the standard error of the leaf physiognomy palaeoclimate data is taken into account. However, our results and interpretations indicate that reconstructions based on leaf physiognomy are influenced by factors not related to climate, such as sample size and differential preservation or transport. In contrast, reconstructions for the same fossil assemblages based on the coexistence approach seem to be less affected by taphonomic variables, but may be less sensitive to minor climate changes.
Ets2 and protein kinase Cepsilon are important regulators of parathyroid hormone-related protein expression in MCF-7 breast cancer cells
2003-06-09

Parathyroid hormone-related protein (PTHrP) promotes the metastatic potential and proliferation of breast cancer cells, and acts anti-apoptotically. In invasive MDA-MB-231 breast cancer cells, transforming growth factor β-regulated PTHrP synthesis is mediated by an Ets1/Smad3-dependent activation of the PTHrP P3 promoter. In the present study, we studied the regulation of PTHrP expression in non-invasive, Ets1-deficient and transforming growth factor β-resistant MCF-7 cells. We found PMA to be a strong stimulator of P3-dependent PTHrP expression in MCF-7 cells. Mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinase (ERK) kinase 1 (MEK-1)/ERK1/2 inhibitor PD98059 interfered with this activity. Promoter studies revealed that the PMA effect depended on the Ets and stimulating protein-1 (Sp1)-binding sites. Of several Ets factors tested, Ets2, but not Ese-1, Elf-1 or Ets1, supported the PMA-dependent increase in promoter activity. PD98059 and a threonine to alanine mutation of the ERK1/2-responsive Ets2 phosphorylation site at position 72 inhibited the Ets2/PMA effect. Activated protein kinase C (PKC)ε could mimic PMA by stimulating the P3 promoter alone or in co-operation with Ets2 in an MEK-1/ERK1/2-dependent manner. Activated PKCα, although capable of co-operating with Ets2, failed to induce transcription from the P3 promoter on its own. The Ets2/PKCα synergistic effect was neither sensitive to PD98059 nor to Thr72/Ala72 mutation. PMA neither increased the expression of Sp1 nor modulated the transcriptional activity of Sp1. However, it induced the displacement of a yet unknown factor from the Sp1-binding site, which may result in Sp1 recruitment to the promoter. Our results suggest an ERK1/2-dependent Ets2/PKCε synergism to be involved in PTHrP expression in MCF-7 breast cancer cells.
A mutant in the essential gene shows phenotypic markers of apoptosis
2003-06-09

We report the study of Kluyveromyces lactis cells expressing a truncated form of KlLSM4, a gene ortholog to LSM4 of Saccharomyces cerevisiae which encodes an essential protein involved in both pre-mRNA splicing and mRNA decapping. We had previously demonstrated that the first 72 amino acids of the K. lactis Lsm4p (KlLsm4Deltap) can restore cell growth in both K. lactis and S. cerevisiae cells not expressing the endogenous protein. However, cells showed a remarkable loss of viability in stationary phase. Here we report that cells expressing KlLsm4Deltap presented clear apoptotic markers such as chromatin condensation, DNA fragmentation, accumulation of reactive oxygen species, and showed increased sensitivity to different drugs. RNA analysis revealed that pre-mRNA splicing was almost normal while mRNA degradation was significantly delayed, pointing to this as the possible step responsible for the observed phenotypes.
Locus of the effect of temporal preparation: Evidence from the lateralized readiness potential
2003-06-10

Abstract It is well established that reaction time (RT) is shorter when a response signal is preceded by a warning signal, because the warning signal causes the participant to prepare for the upcoming response. A review of chronometric and psychophysiological studies reveals the prevailing view that this temporal preparation operates mainly at a motor level speeding up rather late processes. To assess the locus of this preparation effect, we conducted two experiments employing the lateralized readiness potential (LRP). Contrary to this prevailing view, the results of both experiments clearly indicate that temporal preparation enhances the processing speed of relatively early processes, because a manipulation of temporal uncertainty affected RT, the P300 latency, and the stimulus‐to‐LRP interval but not the LRP‐to‐keypress interval.
X‐Ray Pulses from Accretion Columns: Contributions to the Energy Dependence of the Pulse Shape
2003-06-10

We study the pulse profiles of medium-luminosity binary X-ray pulsars in the framework of a column model. The model includes relativistic effects in a Schwarzschild spacetime and the dipolar shape of the accretion funnel. It takes into account mechanisms that are expected to be of major importance for the energy dependence of the pulse shape: energy-dependent local beaming of radiation leaving the column, the luminous halo formed by illumination of the neutron star surface, and magnetic scattering in the upper accretion stream. Beam patterns and pulse profiles are calculated for different values of mass and radius of the neutron star and different local beaming functions. The results illustrate that the energy dependence of the pulse profiles is to a large degree determined by the energy-dependent relative importance of the halo and column contributions to the observed flux.
Analysis of the effect of IL-12 therapy on immunoregulatory T-cell subsets in patients with chronic hepatitis C infection.
2003-06-10

IL-12 therapy in patients with HCV does not alter the production of regulatory cytokines produced by type 1/type 2 TH cells. The significantly enhanced production of BCG-induced TNF-alpha may, however, indicate an activation of antigen presenting cells or natural killer cells.
A topology-shape-metrics approach for the automatic layout of UML class diagrams
2003-06-11

Class diagrams are among the most popular visualizations for object oriented software systems and have a broad range of applications. In many settings it is desirable that the placement of the diagram elements is determined automatically, especially when the diagrams are generated automatically which is usually the case in reverse engineering. For this reason the automatic layout of class diagram gained importance in the last years. Current approaches for the automatic layout of class diagrams are based on the hierarchic graph drawing paradigm. These algorithms produce good results for class diagrams with large and deep structural information, i.e., diagrams with a large and deep inheritance hierarchy. However, they do not perform satisfactorily in absence of this information. We propose in this work a new algorithm for automatic layout of class diagram which is based on the topology-shape-metrics approach. The algorithm is an adaption of sophisticated graph drawing algorithms which have proven their effectiveness in many applications. The algorithm works as well for class diagrams with rich structural information as for class diagrams with few or no structural information. It improves therefore the existing algorithms significantly. An implementation of the algorithm is used in the reverse engineering tool JarInspector.
[Suicidal yew poisoning--from Caesar to today--or suicide instructions on the internet].
2003-06-11

Already the Celts and ancient Germanic peoples knew about the poisonousness of the yew, which played an important part in the mythology of these civilizations. For hunting, the arrows were made poisonous with yew juice, and yew leaves were used for homicide and suicide. In modern times taxine is rarely used with suicidal intent, although this method is actually recommended on the respective Websites. After a 14-year-old boy had intensively studied poisonous plants and methods of suicide on various Websites, he cut leaves from a yew tree (taxus baccata) in his parents' garden, crushed and ingested them and died soon afterwards. At the forensic autopsy pieces of the partially crushed, partially completely preserved yew leaves were found in the stomach. The histological findings were unspecific, e.g. marked general blood congestion of the internal organs and pronounced cerebral and pulmonary edema. When the tree leaves found in the stomach were viewed under the light microscope, a stoma typical of taxus was observed; chemical-toxicological investigations revealed 3,5-dimethoxyphenol in the gastric content, which is considered a marker for the ingestion of taxus.
Anticataleptic activity of cathinone and MDMA (Ecstasy) upon acute and subchronic administration in rat
2003-06-11

Abstract It was recently demonstrated that acute administration of 3,4‐methylenedioxymethamphet‐amine (MDMA, “Ecstasy”) is capable of counteracting haloperidol‐induced catalepsy in rats. The present study was done with another psychostimulant, S‐(−)‐cathinone. In these experiments, 32 male Sprague‐Dawley rats, 225 ± 25 g, were used. They were divided into three groups. All groups received 0.5 mg/kg haloperidol in normal saline (s.c.) as a first injection. Then 30 min later each group received either isotonic phosphate‐buffered saline, 1 mg/kg S‐(−)‐cathinone, or 2.5 mg/kg (RS)‐MDMA (s.c.) as a second injection. The results of descent latency on both the horizontal bar and vertical grid showed that S‐(−)‐cathinone or (RS)‐MDMA upon acute administration induces a strong anticataleptic activity ( P &lt; 0.0001) compared to rats treated with haloperidol plus vehicle. The effect of both drugs was later masked upon subchronic administration (days 2–7, 26–29). This is probably due to sensitization of cataleptic behavior. However, when the same groups of rats were tested on day 8 in a different task, i.e., open‐field, they showed a significant difference ( P &lt; 0.05). The detailed mechanism of the observed strong anticataleptic activity of S‐(−)‐cathinone (which is considered a potent dopamine releaser) requires further investigation. Synapse 49:232–238, 2003. © 2003 Wiley‐Liss, Inc.
Search for somatic 22q11.2 deletions in patients with conotruncal heart defects
2003-06-12

Abstract A wide range of clinical variability in patients with 22q11.2 deletions has been demonstrated in numerous studies. Nevertheless, it is still an open question if major genetic factors contribute to clinical expression. Therefore one aim of this study was to investigate, if patients with 22q11.2 deletion and conotruncal heart defects show a “second hit” somatic 22q11.2 deletion in tissue from the conotruncus, heart vessels or thymus. The second aim was to analyse patients with conotruncal heart defects without 22q11.2 deletion in blood cells for somatic deletion mosaicism. We were able to study tissue samples from heart surgery from 23 patients, 9 of whom had 22q11 deletions by FISH analysis on metaphase spreads from peripheral lymphocytes. Analysis of 18 polymorphic markers from the 22q11.2 region in DNA prepared from thymus and/or heart vessels and/or conotruncus tissue and peripheral lymphocytes in each patient did not show any allelic loss. Thus somatic 22q11.2 deletions apparently do not play a major role in conotruncal heart defects in patients with or without germ line 22q11.2 deletion. © 2003 Wiley‐Liss, Inc.
In vivo Studies of the Genetically Modified Mouse Kidney
2003-06-13

Gene-targeted mice provide a powerful approach to study the physiological and pathophysiological role of a given protein in kidney function and can give insights on the functional importance of these proteins under in vivo conditions as well as on the potential compensating mechanisms in their absence. Full utilisation of these animal models requires adaptation of the respective methods to the size of the mouse. This applies especially to in vivo studies in mice which have to deal with rather small structures and volumes, e.g. vessels for cannulation, plasma volumes or urinary flow rates. Here some aspects which can help to study kidney function in the mouse in vivo are outlined. The applicability of these in vivo methods are stressed by reviewing their very recent application in mice being deficient for either ROMK or SGK1.
Nucleosomes induce lymphocyte necrosis
2003-06-13

Abstract Nucleosomes are major autoantigens in systemic lupus erythematosus. These are found as circulating complexes in both lupus patients and lupus mice. The existence of a potential ubiquitous cellsurface receptor specific for nucleosomes has been suggested. However, neither the nature nor the role of this receptor has been identified. Moreover, the consequence of receptor‐nucleosome interaction on the target cell has not been studied in detail so far. We show here that purified nucleosomes induce cell death of normal and lupus lymphocytes ex vivo in a dose‐ and time‐dependentmanner whereas human dendritic cells were relatively resistant. Most importantly, nucleosome‐induced cell death is primary necrosis. Moreover, necrosis could be abolished when nucleosomes were first treated with deoxyribonuclease I, proteinase K or with a specific monoclonal antibody. Finally, intravenous injections of purified nucleosomes result in a reduced spleen cell number compared to buffer‐injected mice, indicating that circulating nucleosomes may behave similarly in vivo . Taken together, this is the first report indicating that nucleosomes are able to induce necrosis,which in turn could result in an amplification loop of the disease causing the inflammation observed in lupus patients.
Transfection of Dendritic Cells with RNA Induces CD4- and CD8-Mediated T Cell Immunity Against Breast Carcinomas and Reveals the Immunodominance of Presented T Cell Epitopes
2003-06-15

Abstract Transfection of dendritic cells (DC) with tumor-derived RNA has recently been shown to elicit tumor-specific CTL capable of recognizing and lysing a variety of tumor cells. In our study we analyzed the induction of HLA class I- and II-restricted T cell responses against MCF-7 breast cancer cells. Using this approach we were able to elicit CD4- and CD8-mediated antitumor responses. The CTL specifically lysed MCF-7 cells and DC electroporated with MCF-7 RNA, but spared control cell lines. The specificity of the cytotoxic activity was confirmed in cold target inhibition assays and using mAbs blocking HLA class I molecules. Interestingly, these polyclonal cytotoxic T cells recognized selectively two epitopes derived from the MUC1 and Her-2/neu tumor Ags. The induced Th cells were found to be entirely HLA class II restricted and showed a significant cross-reactivity to a renal cell carcinoma cell line, similar to the results obtained with cytotoxic T cells.
A note on the relativistic Euler equations
2003-06-16

We present an alternative way to write the Euler equations for an ideal isentropic fluid as a symmetric hyperbolic system of evolution equations for a timelike vector field. An equation of state has to be provided which relates the length of this vector to the sound velocity. The relation to the conventional formulation is established and some of the consequences are discussed.
Heat Stress-Dependent DNA Binding of Arabidopsis Heat Shock Transcription Factor HSF1 to Heat Shock Gene Promoters in Arabidopsis Suspension Culture Cells in vivo
2003-06-16

Abstract Using UV laser cross-linking and immunoprecipitation we measured the in vivo binding of Arabidopsis heat shock transcription factor HSF1 to the promoters of target genes, Hsp18.2 and Hsp70. The amplification of promoter sequences, co-precipitated with HSF1-specific antibodies, indicated that HSF1 is not bound in the absence of heat stress. Binding to promoter sequences of target genes is rapidly induced by heat stress, continues throughout the heat treatment, and declines during subsequent recovery at room temperature. The molecular mechanisms underlying the differences between Hsp18.2 and Hsp70 in the kinetics of HSF1/promoter binding and corresponding mRNA expression profiles are discussed.
Celecoxib activates a novel mitochondrial apoptosis signaling pathway
2003-06-17

ABSTRACT The cyclooxygenase (COX)‐2 inhibitor Celecoxib may inhibit cancer cell growth independently of its capacity to block the COX‐2 enzyme. The growth inhibitory effect had been attributed to its pro‐apoptotic effects. However, the molecular details of Celecoxib‐induced apoptosis have not been analyzed yet. To differentiate between death receptor and mitochondrial signaling pathways, induction of apoptosis upon treatment with Celecoxib was tested in Jurkat T‐ and BJAB B‐lymphoma cell lines with defects in either pathway. Celecoxib‐induced dose‐ and time‐dependent apoptosis in Jurkat and BJAB cells involving i) activation of caspases‐9, ‐8, and ‐3, ii) cleavage of poly(ADP‐ribose) polymerase and inhibitor of caspase‐activated DNAase, iii) breakdown of the mitochondrial membrane potential, and iv) release of cytochrome c . Lack of Fas‐associated death domain protein (FADD), overexpression of a dominant negative FADD, lack of caspase‐8, and treatment with caspase‐8‐specific inhibitors had no influence on Celecoxib‐induced apoptosis. In contrast, overexpression of a dominant negative caspase‐9 or pharmacological inhibition of caspase‐9 strongly interfered with Celecoxib‐induced cell death. Furthermore, expression of Apaf‐1 was required for Celecoxib‐induced apoptosis. Importantly, Bcl‐2 overexpression did not abrogate caspase activation, mitochondrial alterations, and apoptosis upon Celecoxib treatment while inhibiting radiation induced apoptosis. In conclusion, Celecoxib induces apoptosis via a novel apoptosome‐dependent but Bcl‐2‐independent mitochondrial pathway.
Sites of Interaction between the FecA and FecR Signal Transduction Proteins of Ferric Citrate Transport in Escherichia coli K-12
2003-06-17

ABSTRACT Transcription of the fecABCDE ferric citrate transport genes of Escherichia coli K-12 is initiated by a signaling cascade from the cell surface into the cytoplasm. FecR receives the signal in the periplasm from the outer membrane protein FecA loaded with ferric citrate, transmits the signal across the cytoplasmic membrane, and converts FecI in the cytoplasm to an active sigma factor. In this study, it was shown through the use of a bacterial two-hybrid system that, in the periplasm, the C-terminal FecR 237-317 fragment interacts with the N-terminal FecA 1-79 fragment. In the same C-terminal region, amino acid residues important for the interaction of FecR with FecA were identified by random and site-directed mutagenesis. They were preferentially located in and around a leucine motif (residues 247 to 268) which was found to be highly conserved in FecR-like proteins. The degree of residual binding of FecR mutant proteins to FecA was correlated with the degree of transcription initiation in response to ferric citrate in the culture medium. Three randomly generated inactive FecR mutants, FecR(L254E), FecR(L269G), and FecR(F284L), were suppressed to different degrees by the mutants FecA(G39R) and FecR(D43E). One FecR mutant, FecR (D138E, V197A), induced fecA promoter-directed transcription constitutively in the absence of ferric citrate and bound more strongly than wild-type FecR to FecA. The data showed that FecR interacts in the periplasm with FecA to confer ferric citrate-induced transcription of the fec transport genes and identified sites in FecR and FecA that are important for signal transduction.
Sea-level fluctuations during the last glacial cycle
2003-06-18

The last glacial cycle was characterized by substantial millennial-scale climate fluctuations, but the extent of any associated changes in global sea level (or, equivalently, ice volume) remains elusive. Highstands of sea level can be reconstructed from dated fossil coral reef terraces, and these data are complemented by a compilation of global sea-level estimates based on deep-sea oxygen isotope ratios at millennial-scale resolution or higher. Records based on oxygen isotopes, however, contain uncertainties in the range of +/-30 m, or +/-1 degrees C in deep sea temperature. Here we analyse oxygen isotope records from Red Sea sediment cores to reconstruct the history of water residence times in the Red Sea. We then use a hydraulic model of the water exchange between the Red Sea and the world ocean to derive the sill depth-and hence global sea level-over the past 470,000 years (470 kyr). Our reconstruction is accurate to within +/-12 m, and gives a centennial-scale resolution from 70 to 25 kyr before present. We find that sea-level changes of up to 35 m, at rates of up to 2 cm yr(-1), occurred, coincident with abrupt changes in climate.