julilili42/papers huggingface dataset:
Stimulus-response compatibility in intensity-force relations
2002-09-29

Romaiguère, Hasbroucq, Possamaï, and Seal (1993) reported a new compatibility effect from a task that required responses of two different target force levels to stimuli of two different intensities. Reaction times were shorter when high and low stimulus intensities were mapped to strong and weak force presses respectively than when this mapping was reversed. We conducted six experiments to refine the interpretation of this effect. Experiments 1 to 4 demonstrated that the compatibility effect is clearly larger for auditory than for visual stimuli. Experiments 5 and 6 generalized this finding to a task where stimulus intensity was irrelevant. This modality difference refines Romaiguère et al.'s (1993) symbolic coding interpretation by showing that modality-specific codes underlie the intensity-force compatibility effect. Possible accounts in terms of differences in the representational mode and action effects are discussed.
6-Acetonyldihydroavicine
2002-09-30

The title compound, 1-(5-methyl-5,6-dihydro[1,3]dioxolo[4',5':4,5]benzo[c][1,5]dioxolo[4,5-j]phenanthridin-6-yl)acetone, C(23)H(19)NO(5), isolated from the stem bark of Zanthoxylum rhoifolium, crystallizes as a racemate in space group P1. The structure shows two aromatic ring systems, each terminated by a five-membered dioxole ring, coupled by an N-containing ring. The core of the molecule is almost planar; the planes of the two ring systems form an angle of 18.42 (6) degrees. The packing shows the molecules parallel to each other and about 3.5 A apart with graphite-type interactions. The N-methyl and acetone groups, which are anti with respect to one another, lie out of the plane and pack in spaces between neighbouring molecules.
Applications of Sol−Gel-Processed Interphase Catalysts
2002-10-01

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplications of Sol−Gel-Processed Interphase CatalystsZhong-lin Lu, Ekkehard Lindner, and Hermann A. MayerView Author Information Institut für Anorganische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany Cite this: Chem. Rev. 2002, 102, 10, 3543–3578Publication Date (Web):October 9, 2002Publication History Published online9 October 2002Published inissue 1 October 2002https://pubs.acs.org/doi/10.1021/cr010358thttps://doi.org/10.1021/cr010358tresearch-articleACS PublicationsCopyright © 2002 American Chemical SocietyRequest reuse permissionsArticle Views3056Altmetric-Citations245LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Catalysts,Hydrogenation,Ligands,Materials,Selectivity Get e-Alerts
Two transcriptional regulators GlnR and GlnRII are involved in regulation of nitrogen metabolism in Streptomyces coelicolor A3(2)
2002-10-01

Summary Streptomyces coelicolor has an unusually large arsenal of glutamine synthetase (GS) enzymes: a prokaryotic GSI‐β‐subtype enzyme (encoded by glnA ), three annotated glnA ‐like genes of the GSI‐α‐subtype and a eukaryote‐like glutamine synthetase II (encoded by glnII ). Under all tested conditions, GSI was found to represent the dominant glutamine synthetase activity. A significant heat‐labile GSII activity, which is very low to undetectable in liquid‐grown cultures, was only detected in morphologically differentiating S. coelicolor cultures. Analysis of glnA and glnII transcription by S1 nuclease mapping and egfp fusions revealed that, on nitrogen‐limiting solid medium, glnII but not glnA expression is upregulated. An OmpR‐like regulator protein, GlnR, has previously been implicated in transcriptional control of glnA expression. Gel retardation analysis revealed that GlnR is a DNA‐binding protein, which interacts with the glnA promoter. It is not autoregulatory and does not bind to the upstream regions of the glnA ‐like genes of the α‐subfamily, nor to the glnII promoter in vitro . A second GlnR target was identified upstream of the amtB gene, encoding a putative ammonium transporter. amtB forms an operon with glnK (encoding a PII protein) and glnD (encoding a putative PII nucleotidylyltransferase) shown by S1 nuclease protection analysis and reverse transcription‐polymerase chain reaction (RT‐PCR). An amtB and glnA promoter alignment revealed a putative GlnR operator structure. Downstream of glnII , a gene encoding for another OmpR‐like regulator, GlnRII, was identified, with strong similarity to GlnR. Gel shifts with GlnRII showed that the promoters recognized by GlnR are also targets of GlnRII. However, GlnRII also interacted with the glnII upstream region. Only inactivation of glnR resulted in a glutamine auxotrophic phenotype, whereas the glnRII mutant can grow on minimal medium without glutamine.
A 4bp-Insertion in the eya-Homologous Region (eyaHR) of EYA4 Causes Hearing Impairment in a Hungarian Family Linked to DFNA10
2002-10-01

This family is the third one linked to DFNA10 and revealing a mutation in the EYA4 gene. In all three families, the mutations are localized in different regions of the eyaHR, suggesting that this protein contains several functional subregions with different tissue-specific importance.
Breakpoint medians and breakpoint phylogenies: Afixed-parameter approach
2002-10-01

Abstract With breakpoint distance, the genome rearrangement field delivered one of the currently most popular measures in phylogenetic studies for related species. Here, Breakpoint Median, which is NP-complete already for three given species (whose genomes are represented as signed orderings), is the core basic problem. For the important special case of three species, approximation (ratio 7/6) and exact heuristic algorithms were developed. Here, we provide an exact, fixed-parameter algorithm with provable performance bounds. For instance, a breakpoint median for three signed orderings over nelements that causes at most d breakpoints can be computed in time O((2.15)d·n). We show the algorithm's practical usefulness through experimental studies. In particular, we demonstrate that a simple implementation of our algorithm combined with a new tree construction heuristic allows for a new approach to breakpoint phylogeny, yielding evolutionary trees that are competitive in comparison with known results developed in a recent series of papers that use clever algorithm engineering methods.
Reproducibility and Accuracy of Coronary Calcium Measurements with Multi–Detector Row versus Electron-Beam CT
2002-10-01

By coupling retrospective gating with nearly isotropic volumetric imaging data, spiral multi-detector row CT provides better input data for quantification of coronary arterial calcium volume. Multi-detector row CT allows precise and repeated measurement of coronary arterial calcification, with low interexamination variability.
The GlnD and GlnK homologues of Streptomyces coelicolor A3(2) are functionally dissimilar to their nitrogen regulatory system counterparts from enteric bacteria
2002-10-01

Summary Glutamine synthetase I (GSI) enzyme activity in Streptomyces coelicolor is controlled post‐translationally by the adenylyltransferase (GlnE) as in enteric bacteria. Although other homologues of the Escherichia coli Ntr system ( glnK , coding for a PII family protein; and glnD , coding for an uridylyltransferase) are found in the S. coelicolor genome, the regulation of the GSI activity was found to be different. The functions of glnK and glnD were analysed by specific mutants. Surprisingly, biochemical assay and two‐dimensional PAGE analysis showed that modification of GSI by GlnE occurs normally in all mutant strains, and neither GlnK nor GlnD are required for the regulation of GlnE in response to nitrogen stimuli. Analysis of the post‐translational regulation of GlnK in vivo by two‐dimensional PAGE and mass spectrometry indicated that it is subject to both a reversible and a non‐reversible modification in a direct response to nitrogen availability. The irreversible modification was identified as removal of the first three N‐terminal amino acid residues of the protein, and the reversible modification as adenylylation of the conserved tyro‐sine 51 residue that is known to be uridylylated in E. coli . The glnD insertion mutant expressing only the N‐terminal half of GlnD was capable of adenylylating GlnK, but was unable to perform the reverse deadenylylation reaction in response to excess ammonium. The glnD null mutant completely lacked the ability to adenylylate GlnK. This work provides the first example of a PII protein that is modified by adenylylation, and demonstrates that this reaction is performed by a homologue of GlnD, previously described only as a uridylyltransferase enzyme.
Towards patient‐specific tumor antigen selection for vaccination
2002-10-01

Summary: In this review, we discuss the possibilities for combining the power of molecular analysis of the antigens expressed in a given individual tumor with the design of a tailored vaccine containing defined antigens. Step 1 is a differential gene expression analysis of tumor and corresponding normal tissue. Step 2 is the analysis of human leukocyte antigen (HLA) ligands on tumor cells. Step 3 is data mining with the aim to select those antigens that might be suitable for tumor attack by the adaptive immune system. Step 4 is the on‐the‐spot clinical grade production of the constituents of the patient tailored vaccine, e.g. peptides. Step 5 is then vaccination and monitoring. Although it will not be possible to cover all relevant antigens expressed in a tumor, the antigens that can be identified with our present technical possibilities might be enough for improved immunotherapy. The scope of the present review is to explore the possibilities and the formidable technical and logistical challenge for such individual patient‐oriented antigen definition to be used for therapeutic immunization.
Synaptic plasticity in the acoustic startle pathway: the neuronal basis for short‐term habituation?
2002-10-01

Abstract The aim of the present study was to analyse the cellular mechanism underlying short‐term habituation of the acoustic startle response (ASR). We explored distinct synapses of the neuronal startle pathway in rat brain slices by patch‐clamp recordings of giant neurons in the caudal pontine reticular formation. Presynaptic stimulation of auditory afferents by repeated bursts at 0.1 and 1 Hz led to an exponential decay of EPSC magnitudes. This homosynaptic depression (HSD) was reversible and repeatedly inducible after recovery. Many parameters of HSD in vitro match those of ASR habituation in vivo . The mechanisms underlying HSD are distinct from classical short‐term plasticity: paired‐pulse as well as paired‐burst stimulation revealed a facilitation of the second EPSC, occurring in a much smaller time window up to interstimulus intervals of 200 ms. Pharmacological experiments demonstrated that HSD could be completely blocked by the group II and III metabotropic glutamate receptor antagonist MPPG. Similar results were obtained by CPPG, another group II and III antagonist. In contrast, HSD was not affected by the group I and II antagonist MCPG. We conclude that we found a form of synaptic depression in synapses within the primary startle pathway which correlates in many respects with short‐term habituation of the ASR and which is presumably mediated by group III metabotropic glutamate receptors.
Potential Synergistic Protection of Retinal Ganglion Cells from Axotomy-Induced Apoptosis by Adenoviral Administration of Glial Cell Line-Derived Neurotrophic Factor and X-Chromosome-Linked Inhibitor of Apoptosis
2002-10-01

Following transection of the optic nerve (ON) in the adult rat, retinal ganglion cells (RGCs) undergo degeneration, and within 14 days 85% of axotomized RGCs die by apoptosis. Adenoviral delivery of the mammalian caspase inhibitor X-chromosome-linked inhibitor of apoptosis (Ad.XIAP) to the ON stump leads to expression exclusively in RGCs and rescues 18.9% of the RGCs that would degenerate without treatment. Following adenoviral vector injection into the vitreous body, bioactive glial cell line-derived neurotrophic factor (Ad.GDNF) is expressed in the retina and secreted to rescue 22.8% of lesioned RGCs. Here we report that coadministration of Ad.XIAP retrogradely directed to RGCs and intravitreal Ad.GDNF acts synergistically to protect axotomized RGCs. Combination treatment rescued 47.3% of RGCs that would undergo apoptosis without any treatment as opposed to 37.4% that would be expected if the two treatments acted independently. While without treatment only 15% of axotomized RGCs would survive, combination treatment resulted in survival of 55.4% of the total RGC population. These findings underline the neuroprotective potential of synergistic effects of a combination of different treatment strategies.
Human cytomegalovirus induces a direct inhibitory effect on antigen presentation by monocyte‐derived immature dendritic cells
2002-10-01

Summary. The hypothesis that productive infection of monocyte‐derived immature dendritic cells (DCs) by the human cytomegalovirus (HCMV) is associated with decreased immunostimulatory capacity was tested in this study. DCs were infected with 60–80% efficiency by HCMV strain TB40/E. Infected versus uninfected cells were analysed by fluorescence‐activated cell sorting and by immunocytochemistry for surface expression of major histocompatibility complex (MHC) and co‐stimulatory molecules as well as cytokine secretion during the 3 d after infection. The immunostimulatory capacity of these cells was measured by mixed leucocyte reaction. In spite of the fact that HCMV infection of DCs induced an increased release of tumour necrosis factor‐α (TNF‐α) and a decreased interleukin 10 (IL‐10) production, expression of MHC class I and II, as well as CD40 and CD80 molecules, were downregulated on infected DCs. The mixed leucocyte reaction showed significantly reduced immunostimulatory capacity of infected DC cultures. Simultaneous detection of MHC antigens and virus antigens by double immunofluorescence revealed that downregulation occurred only on infected cells, but not on uninfected bystander cells. These findings demonstrate on a single cell level, together with the marked downregulation of MHC and co‐stimulatory molecules in the presence of high TNF‐α and low IL‐10 levels, a direct inhibitory effect of HCMV on antigen presentation by immature DCs independent of soluble mediators.
Central control of upper airway resistance regulating respiratory airflow in mammals
2002-10-01

Abstract This article reviews recent studies on the importance of glycine receptors for both the spontaneous and the reflex respiratory modulation of the laryngeal abductors and adductors. Our findings show that strychnine blockade of glycine receptors within the brainstem changes the eupneic three‐phase respiratory pattern into two phases. This has major implications for glottal control: (i) the inspiratory glottic abduction and early expiratory adduction were both compromised – a finding mimicked by 5% hypoxia; (ii) closure of the glottis during defensive upper airway reflexes became intermittent and the reflex apnoea reversed to sustained inspiratory discharge. Based on these data, we predict that periods of prolonged hypoxia, such as those that occur during sleep apnoeas, will constrain inspiratory glottic abduction thereby impeding inhalation.
Influence of proteins Bsp and FemH on cell shape and peptidoglycan composition in group B streptococcus c cThe GenBank accession number for the sequence reported in this paper is AJ305309.
2002-10-01

Group B streptococcus (GBS) is surrounded by a capsule. However, little is known about peptidoglycan metabolism in these bacteria. In the present study, a 65 kDa protein was isolated from the culture supernatant of GBS and N-terminally sequenced, permitting isolation of the corresponding gene, termed bsp. The bsp gene was located close to another gene, designated femH, and reverse transcription-PCR revealed a bicistronic transcriptional organization for both genes. The Bsp protein was detected in the culture supernatant from 31 tested clinical isolates of GBS, suggesting a wide distribution of Bsp in these bacteria. Overexpression of bsp resulted in lens-shaped GBS cells, indicating a role for bsp in controlling cell morphology. Insertional disruption of femH resulted in a reduction of the L-alanine content of the peptidoglycan, suggesting that femH is involved in the incorporation of L-alanine residues in the interpeptide chain of the peptidoglycan of GBS.
Androgens and the Development of the Vagina
2002-10-01

Today it is generally held that the vagina develops from sinovaginal bulbs and that the lower third of the definitive vagina is derived from the urogenital sinus. Here we show that the entire vagina arises by downward growth of Wolffian and Müllerian ducts, that the sinovaginal bulbs are in fact the caudal ends of the Wolffian ducts, and that vaginal development is under negative control of androgens. We designed a genetic experiment in which the androgen receptor defect in the Tfm mouse was used to examine the effects of androgens. Vaginal development was studied by 3D reconstruction in androgen-treated female embryos and in complete androgen-insensitive littermates. In androgen-treated females, descent of the genital ducts was inhibited, and a vagina formed in androgen-insensitive Tfm embryos as it does in normal females. By immmunohistochemical localization of the androgen receptor in normal mouse embryos, we demonstrated that the androgen receptor was expressed in Wolffian duct and urogenital sinus-derived structures, and was entirely absent in the Müllerian duct derivatives. We conclude that the Wolffian ducts are instrumental in conveying the negative control by androgens on vaginal development. The results are discussed under evolutionary aspects at the transition from marsupial to eutherian mammals.
ULTRASOUND BIOMICROSCOPY IN CHRONIC OCULAR HYPOTONY
2002-10-01

Ultrasound biomicroscopy is a new tool for detecting the underlying structural abnormalities in ocular hypotony. In cases where clinical examination is not sufficient it can be of great help in deciding on a course of treatment.
Anisotropic s -wave superconductivity: Comparison with experiments on MgB 2 single crystals
2002-10-01

The recently discovered superconductivity in MgB2 has captured world attention due to its simple crystal structure and relatively high superconducting transition temperature Tc=39K. It appears to be generally accepted that it is phonon-mediated s-wave BCS-like superconductivity. Surprisingly, the strongly temperature dependent anisotropy of the upper critical field, observed experimentally in magnesium diboride single crystals, is still lacking a consistent theoretical explanation. We propose a simple single-gap anisotropic s-wave order parameter in order to compare its implications with the prediction of a multi-gap isotropic s-wave model. The quasiparticle density of states, thermodynamic properties, NMR spin-lattice relaxation rate, optical conductivity, and Hc2 anisotropy have been analyzed within this anisotropic s-wave model. We show that the present model can capture many aspects of the unusual superconducting properties of MgB2 compound, though more experimental data appear to be necessary from single crystal MgB2.
Cultivation of Porcine Hepatocytes in Polyurethane Nonwovens as Part of a Biohybrid Liver Support System
2002-10-01

Many patients suffering from end-stage liver disease cannot be transplanted within reasonable time due to the shortage of donor organs. Bioartificial liver support systems may contribute to the liver regeneration or bridging the time until a liver graft for transplantation becomes available. Nonwovens with integrated oxygenation capacity have been developed and manufactured by melt blow technology using thermoplastic polyurethane. Capillary membranes for oxygenation were integrated into the nonwoven during the processing. The polyurethane nonwoven structures with adapted pore size and high pore volume allow high cell densities in the hepatocyte culture. The three-dimensional cell culture was housed by a flow bioreactor system and was integrated in a closed loop circulation with monitoring possibilities for pressure, pH, temperature, ammonia, and oxygen. Hepatocytes were isolated from rats or pigs by collagenase perfusion and infused into the medium-perfused circulation. Cells showed high viability and hepatocyte specific cytochrome P450-dependent metabolic function in culture (MEGX test).
Mg2+ sensitizes KATP channels to inhibition by DIDS: dependence on the sulphonylurea receptor subunit
2002-10-01

ATP‐sensitive potassium channels (K ATP channels) consist of pore‐forming Kir6.x subunits and of sulphonylurea receptors (SURs). In the absence of Mg 2+ , the stilbene disulphonate, DIDS, irreversibly inhibits K ATP channels by binding to the Kir subunit. Here, the effects of Mg 2+ on the interaction of DIDS with recombinant K ATP channels were studied in electrophysiological and [ 3 H]‐glibenclamide binding experiments. In inside‐out macropatches, Mg 2+ (0.7 m M ) increased the sensitivity of K ATP channels towards DIDS up to 70 fold (IC 50 =2.7 μ M for Kir6.2/SUR2B). Inhibition of current at DIDS concentrations 10 μ M was irreversible. Mg 2+ sensitized the truncated Kir6.2Δ26 channel towards inhibition by DIDS only upon coexpression with a SUR subunit (SUR2B). The effect of Mg 2+ did not require the presence of nucleotides. [ 3 H]‐glibenclamide binding to SUR2B(Y1206S), a mutant with improved affinity for glibenclamide, was inhibited by DIDS. The potency of inhibition was increased by Mg 2+ and by coexpression with Kir6.2. In the presence of Mg 2+ , DIDS inhibited binding of [ 3 H]‐glibenclamide to Kir6.2/SUR2B(Y1206S) with IC 50 =7.9 μ M by a non‐competitive mechanism. Inhibition was fully reversible. It is concluded that the binding site of DIDS on SUR that is sensed by glibenclamide does not mediate channel inhibition. Instead, Mg 2+ binding to SUR may allosterically increase the accessibility and/or reactivity of the DIDS site on Kir6.2. The fact that the Mg 2+ effect does not require the presence of nucleotides underlines the importance of this ion in modulating the properties of the K ATP channel. British Journal of Pharmacology (2002) 137 , 429–440. doi: 10.1038/sj.bjp.0704905