julilili42/papers huggingface dataset:
Christmas tree case study: computed tomography as a tool for mastering complex real world objects with applications in computer graphics
2003-06-26

We report on using computed tomography (CT) as a model acquisition tool for complex objects in computer graphics. Unlike other modeling and scanning techniques the complexity of the object is irrelevant in CT, which naturally enables to model objects with, for example, concavities, holes, twists or fine surface details. Once the data is scanned, one can apply post-processing techniques for data enhancement, modification or presentation. For demonstration purposes we chose to scan a Christmas tree which exhibits high complexity which is difficult or even impossible to handle with other techniques. However, care has to be taken to achieve good scanning results with CT. Further, we illustrate post-processing by means of data segmentation and photorealistic as well as non-photorealistic surface and volume rendering techniques.
Bromobalhimycin and Chlorobromobalhimycins—Illuminating the Potential of Halogenases in Glycopeptide Antibiotic Biosyntheses
2003-06-27

Can bromine beat bacteria? By varying the amounts of chloride and bromide salts in fermentation culture media, we have generated novel sets of vancomycin-type glycopeptides with bromine substitution. This study extends the sequence of substituents at the aglycon moiety of balhimycin from H through F and Cl to Br (see scheme) and opens up possibilites for the investigation of substituent effects upon the activity of glycopeptide antibiotics. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2268/2003/z619_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.
Ground states and bias-current-induced rearrangement of semifluxons in0−πlong Josephson junctions
2003-06-27

We investigate numerically a long Josephson junction with several phase pi-discontinuity points. Such junctions are usually fabricated as a ramp between an anisotropic cuprate superconductor like YBCO and an isotropic metal superconductor like Nb. From the top, they look like zigzags with pi-jumps of the Josephson phase at the corners. These pi-jumps, at certain conditions, lead to the formation of half-integer flux quanta, which we call semifluxons (SF), pinned at the corners. We show (a) that the spontaneous formation of SFs depends on the junction length, (b) that the ground state without SFs can be converted to a state with SFs by applying a bias current, (c) that the SF configuration can be rearranged by the bias current. All these effects can be observed using a SQUID microscope.
Synthesis and Characterization of Soluble Octaaryl‐ and Octaaryloxy‐Substituted Metal‐Naphthalocyanines
2003-06-30

Abstract An easy route for the synthesis of vanadium, zinc, magnesium, etc. complexes of new soluble symmetrical octa( m ‐trifluoromethylphenyl) or octa( m ‐trifluoromethylphenoxy) substituted 2,3‐naphthalocyanines {[( m ‐CF 3 Ph) 8 NcM] or [( m ‐CF 3 PhO) 8 NcM]} in good yields is described in detail. The structures of the synthesized compounds were verified by UV/Vis and 1 H and 13 C NMR spectroscopy, as well as by mass spectrometry. The good solubilities of the prepared compounds in toluene and coordinating solvents (e.g., THF), was explained in terms of the nonplanar arrangements of eight m ‐CF 3 Ph substituents in relation to the Nc macrocycle, preventing aggregation of the molecules. The Q‐bands in the UV/Vis spectra of the [( m ‐CF 3 Ph) 8 NcM] species are each bathochromically shifted by ca. 13 nm in relation to [( m ‐CF 3 PhO) 8 NcM] species, appearing at 817 nm for [( m ‐CF 3 Ph) 8 NcVO] in toluene. All NcMs prepared exhibit very high molar extinction coefficients for the Q‐band {lg(ε) ≈︁ 5.6} in THF. Some of prepared Nc complexes appeared to be very unstable on exposure to daylight. In addition, a nickel‐catalyzed Kumada cross‐coupling synthesis of substituted o ‐terphenyls, intermediate compounds for the preparation of octaaryl‐substituted Ncs, is described. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2003)
Concerning the quark condensate
2003-06-30

A continuum expression for the trace of the massive dressed-quark propagator\\nis used to explicate a connection between the infrared limit of the QCD Dirac\\noperator's spectrum and the quark condensate appearing in the operator product\\nexpansion, and the connection is verified via comparison with a lattice-QCD\\nsimulation. The pseudoscalar vacuum polarisation provides a good approximation\\nto the condensate over a larger range of current-quark masses.\\n
Symbiotic Status, Phosphate, and Sucrose Regulate the Expression of Two Plasma Membrane H+-ATPase Genes from the Mycorrhizal Fungus Glomus mosseae
2003-07-01

Abstract The establishment of the arbuscular mycorrhizal symbiosis results in a modification of the gene expression pattern in both plant and fungus to accomplish the morphological and physiological changes necessary for the bidirectional transfer of nutrients between symbionts. H+-ATPase enzymes play a key role establishing the electrochemical gradient required for the transfer of nutrients across the plasma membrane in both fungi and plants. Molecular analysis of the genetic changes in arbuscular mycorrhizal fungi during symbiosis allowed us to isolate a fungal cDNA clone encoding a H+-ATPase, GmPMA1, from Glomus mosseae (BEG12). Despite the high conservation of the catalytic domain from H+-ATPases, detailed analyses showed that GmPMA1 was strongly related only to a previously identified G. mosseae ATPase gene, GmHA5, and not to the other four ATPase genes known from this fungus. A developmentally regulated expression pattern could be shown for both genes, GmPMA1 and GmHA5. GmPMA1 was highly expressed during asymbiotic development, and its expression did not change when entering into symbiosis, whereas the GmHA5 transcript was induced upon plant recognition at the appressorium stage. Both genes maintained high levels of expression during intraradical development, but their expression was reduced in the extraradical mycelium. Phosphate, a key nutrient to the symbiosis, also induced the expression of GmHA5 during asymbiotic growth, whereas sucrose had a negative effect. Our results indicate that different fungal H+-ATPases isoforms might be recruited at different developmental stages possibly responding to the different requirements of the life in symbiosis.
Construction of an Expression System for Site-DirectedMutagenesis of the LantibioticMersacidin
2003-07-01

ABSTRACT The lantibiotic (i.e., lanthionine-containing antibiotic) mersacidin is an antimicrobial peptide of 20 amino acids which is produced by Bacillus sp. strain HIL Y-85,54728. Mersacidin inhibits bacterial cell wall biosynthesis by binding to the precursor molecule lipid II. The structural gene of mersacidin ( mrsA ) and the genes for the enzymes of the biosynthesis pathway, dedicated transporters, producer self-protection proteins, and regulatory factors are organized in a biosynthetic gene cluster. For site-directed mutagenesis of lantibiotics, the engineered genes must be expressed in an expression system that contains all of the factors necessary for biosynthesis, export, and producer self-protection. In order to express engineered mersacidin peptides, a system in which the engineered gene replaces the wild-type gene on the chromosome was constructed. To test the expression system, three mutants were constructed. In S16I mersacidin, the didehydroalanine residue (Dha) at position 16 was replaced with the Ile residue found in the closely related lantibiotic actagardine. S16I mersacidin was produced only in small amounts. The purified peptide had markedly reduced antimicrobial activity, indicating an essential role for Dha16 in biosynthesis and biological activity of mersacidin. Similarly, Glu17, which is thought to be an essential structure in mersacidin, was exchanged for alanine. E17A mersacidin was obtained in good yields but also showed markedly reduced activity, thus confirming the importance of the carboxylic acid function at position 17 in the biological activity of mersacidin. Finally, the exchange of an aromatic for an aliphatic hydrophobic residue at position 3 resulted in the mutant peptide F3L mersacidin; this peptide showed only moderately reduced activity.
Matching or Competition? Performance Comparison Processes in an Idea Generation Task
2003-07-01

Performance matching due to social comparison has been proposed as one explanation for the observed productivity loss in group brainstorming (Brown &amp; Paulus, 1996; Paulus &amp; Dzindolet, 1993). According to Festinger (1954), however, social comparison should not lead to performance matching but rather to competition. In our first experiment, we tested this hypothesis for a coactive situation and found enhanced performance due to interpersonal competition but no performance matching. In the second experiment, we attempted to replicate this result with interactive dyads and introduced an outgroup in order to shift competition from the interpersonal to the intergroup level. Both the replication and the shift of competition were successful. The intergroup competition was not accompanied by performance matching within the dyads.
Out-of-core compression for gigantic polygon meshes
2003-07-01

Polygonal models acquired with emerging 3D scanning technology or from large scale CAD applications easily reach sizes of several gigabytes and do not fit in the address space of common 32-bit desktop PCs. In this paper we propose an out-of-core mesh compression technique that converts such gigantic meshes into a streamable, highly compressed representation. During decompression only a small portion of the mesh needs to be kept in memory at any time. As full connectivity information is available along the decompression boundaries, this provides seamless mesh access for incremental in-core processing on gigantic meshes. Decompression speeds are CPU-limited and exceed one million vertices and two million triangles per second on a 1.8 GHz Athlon processor.A novel external memory data structure provides our compression engine with transparent access to arbitrary large meshes. This out-of-core mesh was designed to accommodate the access pattern of our region-growing based compressor, which - in return - performs mesh queries as seldom and as local as possible by remembering previous queries as long as needed and by adapting its traversal slightly. The achieved compression rates are state-of-the-art.
Thiazolidinediones – some recent developments
2003-07-01

The role of thiazolidinediones (currently rosiglitazone and pioglitazone) in the treatment of Type 2 diabetes is firmly established. The mechanism of action involves binding to the peroxisome proliferator-activated receptor-gamma, a transcription factor that regulates the expression of specific genes especially in fat cells but also other cell types such as endothelial cells, macrophages and monocytes, vascular smooth muscle cells and colonic epithelium. Thiazolidinediones have been shown to interfere with expression and release of mediators of insulin resistance originating in adipose tissue (e.g., increased free fatty acids, decreased adiponectin) in a way that results in net improvement of insulin sensitivity (i.e., in muscle and liver). A direct or indirect effect on AMP-dependent protein kinase may also be involved. Prevention of lipid accumulation in tissues critical to glycaemia such as visceral adipocytes, liver, muscle and beta-cells at the expense of lipids accumulating at the less harmful subcutaneous site may be central to their net metabolic effect. The sustained beneficial effect of troglitazone on beta-cell function in women with previous gestational diabetes in addition to the insulin-sensitising properties point to an important role of this class of drugs in the prevention of Type 2 diabetes. Original safety concerns based on animal and in vitro studies (e.g., fatty bone marrow transformation, colonic cancer, adipogenic transdifferentiation of blood cells) remain theoretical issues but become less pressing practically with prolonged uneventful clinical use. Hepatotoxicity for troglitazone and fluid retention, which can aggravate pre-existing heart failure, are the most important side effects. In summary, with the thiazolidinediones, a novel concept for the treatment of insulin resistance and possibly preservation of beta-cell function is available that could become effective in the prevention of Type 2 diabetes. Moreover, their anti-inflammatory properties also make them interesting in the prevention and treatment of atherosclerosis and possibly other inflammatory conditions (e.g., inflammatory bowel disease). Long-term data will be necessary for a final risk-benefit assessment of these substances.
Preoperative magnetic source imaging for brain tumor surgery: a quantitative comparison with intraoperative sensory and motor mapping
2003-07-01

Object The aim of this study was to compare quantitatively the methods of preoperative magnetic source (MS) imaging and intraoperative electrophysiological cortical mapping (ECM) in the localization of sensorimotor cortex in patients with intraaxial brain tumors. Methods Preoperative magnetoencephalography (MEG) was performed while patients received painless tactile somatosensory stimulation of the lip, hand, and foot. The early somatosensory evoked field was modeled using a single equivalent current dipole approach to estimate the spatial source of the response. Three-dimensional magnetic resonance image volume data sets with fiducials were coregistered with the MEG recordings to form the MS image. These individualized functional brain maps were integrated into a neuronavigation system. Intraoperative mapping of somatosensory and/or motor cortex was performed and sites were compared. In two subgroups of patients we compared intraoperative somatosensory and motor stimulation sites with MS imaging–based somatosensory localizations. Mediolateral projection of the MS imaging source localizations to the cortical surface reduced systematic intermodality discrepancies. The distance between two corresponding points determined using MS imaging and ECM was 12.5 ± 1.3 mm for somatosensory–somatosensory and 19 ± 1.3 mm for somatosensory–motor comparisons. The observed 6.5 mm increase in site separation was systematically demonstrated in the anteroposterior direction, as expected from actual anatomy. In fact, intraoperative sites at which stimulation evoked the same patient response exhibited a spatial variation of 10.7 ± 0.7 mm. Conclusions Preoperative MS imaging and intraoperative ECM show a favorable degree of quantitative correlation. Thus, MS imaging can be considered a valuable and accurate planning adjunct in the treatment of patients with intraaxial brain tumors.
Supported Organometallic Complexes. XXXVIII [1] Bis(methoxyethyldimethylphosphine)ruthenium(II) Complexes as Transfer Hydrogenation Catalysts
2003-07-01

Abstract Diamineruthenium(II) complexes containing the hemilabile methoxyethyldimethylphosphine ligand, [Cl 2 Ru( L n )(η 1 ‐Me 2 PCH 2 CH 2 OMe) 2 ] ( 2L n ) (n = 1‐12, Scheme 1), have been synthesized from the starting materials Me 2 PCH 2 CH 2 OMe, [Ru(COD)Cl 2 ] n , and the respective diamines L 1 ‐ L 12 . The structure of complex 2L 5 reveals that two chlorides are in trans position, while in complex 2L 11 the two chlorides favor a cis configuration. Most of the complexes are highly catalytic active in the hydrogen transfer reduction of acetophenone. The experimental study indicates that the replacement of phenyl groups for methyl functions in the ether‐phosphine ruthenium(II) complexes resulted in a switch of the hydrogenation mechanism from direct hydrogenation to transfer hydrogenation. The reason is attributed to the better donor ability of methyl groups compared to phenyl substitutents. Thus the metal center becomes more electron‐rich and inhibits the binding of dihydrogen to the ruthenium(II) complex fragment.
Disturbed Sound Lateralization in Patients with Spatial Neglect
2003-07-01

Previous studies on auditory space perception in patients with neglect have investigated localization of free-field-sound stimuli or lateralization of dichotic stimuli that are perceived intracranially. Since those studies in part revealed contradictory results, reporting either systematic errors to the left or systematic errors to the right, we reassessed the ability of auditory lateralization in patients with right hemispheric lesions with and without neglect. Unexpectedly, about half of the patients with neglect showed erratic judgments on sound position, that is, they were completely unable to lateralize sounds. The remaining neglect patients only showed a small deviation of the auditory median plane to the left side, indicating that they perceived the sounds as slightly shifted to the right side. The comparison between both groups revealed higher severity of neglect in the group of neglect patients who were unable to perform the task, suggesting that the inability of sound lateralization was associated with the strength of clinical neglect. However, we also observed 1 out of 9 patients with left brain damage who was not able to lateralize spatial sounds. This patient did not show any symptoms of spatial neglect. Thus, it may be that a spatial auditory deficit, such as that observed here in right-brain-damaged patients, only co-occurs with spatial neglect if the right superior temporal cortex is lesioned.
Reduced Skeletal Muscle Oxygen Uptake and Reduced β-Cell Function
2003-07-01

OBJECTIVE—Studies on insulin sensitivity and insulin secretion in subjects with a familial predisposition for type 2 diabetes mellitus (T2DM) traditionally produce inconsistent results. This may be due to small sample size, subject selection, matching procedures, and perhaps lack of a measure of physical fitness. RESEARCH DESIGN AND METHODS—In the present study, we specifically tested the hypothesis that a family history of T2DM is associated with reduced Vo2max, measured by incremental bicycle ergometry, independent of insulin sensitivity estimated from an oral glucose tolerance test (OGTT; n = 424) and measured by a euglycemic-hyperinsulinemic clamp (n = 185). Subjects included in the study were young (34 ± 10 years), healthy, and normal glucose tolerant with either a first-degree relative (FDR) with T2DM (n = 183), a second-degree relative with T2DM (n = 94), or no family history of T2DM (control subjects, n = 147). BMI, percent body fat, waist-to-hip ratio (WHR), and habitual physical activity (HPA; standard questionnaire) were comparable among groups. FDRs had significantly lower Vo2max than control subjects: 40.5 ± 0.6 vs. 45.2 ± 0.9 ml O2/kg lean body mass, P = 0.01 after adjusting for sex, age, BMI, HPA, and insulin sensitivity (euglycemic-hyperinsulinemic clamp). RESULTS—BMI, percent body fat, waist-to-hip ratio (WHR), and habitual physical activity (HPA; standard questionnaire) were comparable among groups. FDRs had significantly lower Vo2max than control subjects: 40.5 ± 0.6 vs. 45.2 ± 0.9 ml O2/kg lean body mass, P = 0.01 after adjusting for sex, age, BMI, HPA, and insulin sensitivity (euglycemic-hyperinsulinemic clamp). Insulin sensitivity per se was not affected by family history of T2DM after adjusting for age, sex, BMI, and percent body fat (P = 0.76). The appropriateness of β-cell function for the individual insulin sensitivity (disposition index: product of a validated secretion parameter [OGTT] and sensitivity [clamp]) was significantly lower in FDRs (87 ± 4 units) versus control subjects (104 ± 6 units, P = 0.02 after adjusting for sex, age, and BMI). Analyses of the larger OGTT group produced essentially the same results. CONCLUSIONS—In conclusion, these data are compatible with the hypothesis that familial predisposition for T2DM impairs maximal oxygen consumption in skeletal muscle. Because habitual physical activity was not different, genetic factors may be involved. Conceivably, reduced Vo2max precedes skeletal muscle insulin resistance, providing a partial explanation for discrepancies in the literature.
Identification of an HLA‐A*0201‐restricted T‐cell epitope derived from the prostate cancer‐associated protein trp‐p8
2003-07-01

Abstract BACKGROUND New concepts for the immunotherapy of prostate carcinoma (PCa) largely depend on the identification of suitable target antigens that are present in a high percentage of prostate tumors. Their expression in normal tissues should be restricted to the prostate and they should be immunogenic in vivo. The number of antigens displaying these properties is still limited. Here, we identify for the first time an immunogenic peptide derived from the prostate‐specific protein transient receptor potential‐p8 (trp‐p8) that is recognized by cytotoxic T lymphocytes (CTLs) from PCa patients. METHODS To determine the abundance of trp‐p8 in prostate tumors, the expression level of trp‐p8 mRNA was quantitatively analyzed in a panel of prostate cancer tissues. Trp‐p8‐derived human leukocyte antigen (HLA)‐A*0201‐restricted peptides were selected and tested for the in vitro activation of CTLs when loaded on autologous dendritic cells (DCs). RESULTS Trp‐p8 mRNA was found to be expressed in all prostate tumors and in the corresponding normal prostate tissue. Of five selected trp‐p8‐derived peptides, only peptide GLMKYIGEV was shown to activate specific CTLs, which effectively lysed PCa cells confirming the endogenous generation and presentation of this peptide by tumor cells. CONCLUSIONS Our results suggest this antigen as a suitable target for the T‐cell‐based immunotherapy of PCa. Prostate 56: 270–279, 2003. © 2003 Wiley‐Liss, Inc.
Value of comparative genomic hybridization and fluorescence in situ hybridization for molecular diagnostics in multiple myeloma
2003-07-01

Summary. Chromosomal abnormalities, such as 13q deletions, are emerging as important prognostic factors in multiple myeloma. Fluorescence in situ hybridization (FISH) using specific DNA probes is the technique most widely used for the determination of genomic aberrations in this disease. The utility of comparative genomic hybridization (CGH) for molecular diagnostics in plasma cell malignancies has not been systematically analysed. We investigated tumour samples of patients with multiple myeloma ( n = 43) or plasma cell leukaemia ( n = 3) using CGH and FISH with five DNA probes localized to chromosome bands 1p22, 6q21, 11q22–q23, 13q14 and 17p13. By CGH, the most frequent genomic changes were gains on chromosomes 1q, 9q and 11q, as well as losses on chromosomes 13q, 6q, Xp and Xq. By FISH, trisomy 11q was identified at a similar frequency to the 13q deletion (42%). Compared with FISH data, the sensitivity of CGH was 80·7% and the specificity was 97·5%. Thirty‐two aberrations found by FISH were not identified by CGH, mostly as a result of the proportion of cells carrying the respective aberrations, or because of the limited spatial resolution of CGH. Our data indicate that, for clinical molecular diagnostics in multiple myeloma, FISH with a disease‐specific DNA probe set is superior to CGH analysis.
The Effects of Fresh Frozen Plasma on Neutrophil-Endothelial Interactions
2003-07-01

During shock, fluid administration leads to a massive dilution of plasma. Apart from maintaining hemodynamics, this might affect tissue damage by influencing leukocyte accumulation in the microvasculature. Using endothelial cells, isolated neutrophils, and a parallel plate flow chamber, we studied the effects of fresh frozen plasma on neutrophil-endothelial interactions.