gebhart/patrepeval huggingface dataset:
Stimulation of B lymphocytes through surface Ig receptors induces LFA-1 and ICAM-1-dependent adhesion (1991)

Engagement of the surface Ig receptor with anti-IgM antibodies stimulates murine B lymphocytes to markedly increase their expression of the cell adhesion molecules ICAM-1 and LFA-1. Stimulated B cells display increased homotypic adhesiveness and form spontaneous heterotypic conjugates with T lymphocytes. This latter T-B cell interaction is further enhanced if T cells have been previously activated with phorbol esters. In all cases, the formation of cell-cell conjugates is dependent on LFA-1-ICAM-1-mediated interactions as assessed in mAb blocking experiments. B lymphocytes stimulated with anti-IgM display a marked increase in binding to ICAM-1-transfected L cells. This cell-cell interaction is inhibited by anti-LFA-1 mAb binding to the B lymphocyte. Together, these results demonstrate that there is an induction of both ICAM-1 and LFA-1 on stimulated B cells and a corresponding increase in the adhesiveness of these cells. These findings suggest that Ag binding to the surface Ig receptor could prepare a B lymphocyte for subsequent interaction with a T lymphocyte. This provides insight into how efficient T-B collaboration may occur between very infrequent Ag-specific lymphocytes.
Reduction of restoration capacity requirements in advanced optical networks (2002)

This paper investigates the required excess capacity and the required number of optical transceivers for restoration against single link or node failures in future metropolitan area networks (MANs) and wide area networks (WANs). The following aspects of optical networking technology are taken into account: (i) electronic switching and optical transmission with one wavelength per fiber, (ii) wavelength division multiplexing (WDM), (iii) tunable transmitters and receivers, (iv) optical bypass technology, and (v) wavelength conversion. An example network is studied. It is concluded that all of the gain in fiber miles is obtained by wavelength division multiplexing, which provides a gain of about M, the number of wavelengths. The number of transmitters and receivers (equivalently, the electronic switch size) is reduced slightly by tunable transmitter and receivers; to reduce these numbers to their minimum (a reduction by a factor of two) requires optical bypass technology. These results lead to the conclusion that with an electrical cross-connect, and in particular, due to its flexible granularity, with an asynchronous transfer mode (ATM)-based cross-connect, and with WDM-based point-to-point optical transport, very efficient failure recovery techniques can be constructed. More advanced optical technology for switching reduces the number of transceivers and electronic switch sizes by a factor of two for restoration purposes. The absolute gain in fiber miles, number of transceivers, and electronic switch sizes increases when the network demand increases. However, the prohibitive cost of laying new fiber cable makes the gain achieved by WDM alone the most important factor in advanced optical network restoration.
Differentiation of Pseudomonas aeruginosa into the alginate‐producing form: inactivation of mucB causes conversion to mucoidy (1993)

Mucoidy in Pseudomonas aeruginosa is a critical virulence factor associated with chronic respiratory infections in cystic fibrosis. A cluster of three tightly linked genes, algU, mucA and mucB located at 67.5 min, controls development of mucoid phenotype. This locus is allelic with a group of mutations (muc) associated with conversion into constitutively mucoid forms. One of the genes previously characterized in this region, algU, is absolutely required for the transcriptional activation of algD, a critical event in the establishment of mucoidy. AlgU is homologous to the alternative sigma factor sigma H (Spo0H) controlling sporulation and competence in Bacillus. Two genes downstream of algU, mucA and mucB were further characterized in this study. Previous complementation studies have demonstrated that mucA is required for suppression of mucoidy in the muc-2 strain PAO568. In this work, complementation analysis indicated that, in addition, mucB was required for suppression of mucoidy in the muc-25 strain PAO581, and for enhanced complementation of the muc-2 mutation in PAO568. The complete nucleotide sequence of mucA and mucB was determined. Insertional inactivation of mucB on the chromosome of the standard genetic strain PAO resulted in mucoid phenotype, and in a strong transcriptional activation of algD. Thus, a loss of mucB function is sufficient to cause conversion of P. aeruginosa into the mucoid phenotype. Since the algU-mucA-mucB region is a general site where muc mutations have been mapped, it is likely that mucB participates in the emergence of mucoid forms. Both mucA and mucB play a regulatory role in concert with the sigma-like factor AlgU; all three genes, along with signal transduction and histone-like elements, control differentiation of P. aeruginosa into the mucoid phenotype.
Optimization of microfluidic single cell trapping for long-term on-chip culture (2010)

The poor efficiency of microfluidic single cell trapping is currently restricting the full potential of state-of-the-art single cell analyses. Using fluid dynamics simulations in combination with particle image velocimetry to systematically optimize trap architectures, we present a microfluidic chip with enhanced single cell trapping and on-chip culture performance. Upon optimization of trap geometries, we measured trapping efficiencies of up to 97%. Our device also enables the stable, relatively long-term culture of individual non-adherent mammalian cells in high-throughput without a significant decrease in cell viability. As a first application of this platform we demonstrate the automated separation of the two daughter cells generated upon single cell division. The reliable trapping and re-trapping of mammalian cells should for example provide the fundament for novel types of investigations in stem cell and tumour cell biology, which depend on reliable tracking of genealogical relationships such as in stem cell lineage tracking.
Genetic Dissection of Acquired Resistance to Disease (1997)

Plants come in frequent contact with potentially pathogenic fungi, bacteria, and viruses, yet disease results from relatively few of these exposures. In many cases an encounter leaves no obvious trace of its occurrence and the microbe fails to establish itself due to a lack in activation of pathogenicity functions or to highly effective plant defense mechanisms. Other encounters leave evidence of an intense plant-microbe interaction that results in the arrest of pathogen development after attempted colonization. In these cases plant tissues often display activated defense functions that produce antimicrobial compounds, enzymes, and structural reinforcements that may limit pathogen growth (Dixon and Lamb, 1990). These reactions may also be associated with the HR, a localized region of plant cell death around infection sites. An HR may involve just a single cell or it can produce death of extensive regions of tissue. The combination of defense activities can limit infection and prevent it from spreading to other tissues. The effectiveness of these defense strategies is determined both by the rate of host activation of defenses and by the rate of expansion of the pathogen colony. Therefore, in the evolution of plants and their pathogens, traits that permit rapid and effective defense responses should be favored in the evolution of the host, whereas desirable pathogen traits are those that enable rapid growth or facilitate evasion, suppression, or tolerance of host reactions.
Elucidating the Mechanism of Laccase and Tyrosinase in Wheat Bread Making (2007)

Cross-linking enzymes generate covalent bonds in and between food biopolymers. These enzymes are interesting tools for tailoring dough and bread structures, as the characteristics of the biopolymers significantly determine the viscoelastic and fracture properties of dough and bread. In this study, the influence of oxidative cross-linking enzymes, tyrosinase from the filamentous fungus Trichoderma reesei and laccase from the white rot fungus Trametes hirsuta, on dough and bread were examined. Oxidation of low molecular weight phenolic model compounds of flour, cross-linking of gluten proteins, dough rheology, and bread making were characterized during or after the enzymatic treatments. In the dough and bread experiments, laccase and tyrosinase were also studied in combination with xylanase. Of the model compounds tyrosine, p-coumaric acid, caffeic acid, ferulic acid, and Gly-Leu-Tyr tripeptide, tyrosinase oxidized all except ferulic acid. Laccase was able to oxidize each of the studied compounds. The phenolic acids were notably better substrates for laccase than l-tyrosine. When the ability of the enzymes to cross-link isolated gliadin and glutenin proteins was studied by the SDS-PAGE analysis, tyrosinase was found to cross-link the gliadin proteins effectively, whereas polymerization of the gliadins by laccase was observed only when a high enzyme dosage and prolonged incubation were used. Examination of large deformation rheology of dough showed that both laccase and tyrosinase made doughs harder and less extensible, and the effects increased as a function of the enzyme dosage. In bread making, interestingly, the pore size of the breads baked with tyrosinase turned out to be remarkably larger and more irregular when compared to that of the other breads. Nevertheless, both of the oxidative enzymes were found to soften the bread crumb and increase the volume of breads, and the best results were achieved in combination with xylanase.
Metalorganic vapor-phase epitaxial growth of vertically well-aligned ZnO nanorods (2002)

We report metalorganic vapor-phase epitaxial growth and structural and photoluminescent characteristics of ZnO nanorods. The nanorods were grown on Al2O3(00⋅1) substrates at 400 °C without employing any metal catalysts usually needed in other methods. Electron microscopy revealed that nanorods with uniform distributions in their diameters, lengths, and densities were grown vertically from the substrates. The mean diameter of the nanorods is as narrow as 25 nm. In addition, x-ray diffraction measurements clearly show that ZnO nanorods were grown epitaxially with homogeneous in-plane alignment as well as a c-axis orientation. More importantly, from photoluminescence spectra of the nanorods strong and narrow excitonic emission and extremely weak deep level emission were observed, indicating that the nanorods are of high optical quality.
The receptor for Bacillus thuringiensis CrylA(c) delta‐endotoxin in the brush border membrane of the lepidopteran Manduca sexta is aminopeptidase N (1994)

A 120 kDa glycoprotein in the larval midgut membrane of the lepidopteran Manduca sexta, previously identified as a putative receptor for Bacillus thuringiensis CrylA(c) delta-endotoxin, has been purified by a combination of protoxin affinity chromatography and anion exchange chromatography. In immunoblotting experiments, the purified glycoprotein has the characteristics predicted of the receptor: it binds CrylA(c) toxin in the presence of GlcNAc but not GalNAc; it binds the lectin SBA; but it does not bind CrylB toxin. N-terminal and internal amino acid sequences obtained from the protein show a high degree of similarity with the enzyme aminopeptidase N (EC 3.4.11.2). When assayed for aminopeptidase activity, purified receptor preparations were enriched 5.3-fold compared to M. sexta brush border membrane vesicles. We propose that the receptor for CrylA(c) toxin in the brush border membrane of the lepidopteran M. sexta is the metalloprotease aminopeptidase N.
Detection of Human Gastric Cancer in Resected Specimens Using a Novel Infrared Fluorescent Anti-Human Carcinoembryonic Antigen Antibody with an Infrared Fluorescence Endoscope in Vitro (2001)

An anti-CEA antibody with affinity for cancerous lesions and labeled with ICG-sulfo-OSu can therefore be imaged using this infrared fluorescence endoscope. Specific antibodies tagged with ICG-sulfo-OSu can label cancer cells and can generate a strong enough fluorescent signal to detect small cancers when examined with an infrared fluorescence endoscope.
Mutations in the PCSK9 gene in Norwegian subjects with autosomal dominant hypercholesterolemia (2004)

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is at a locus for autosomal dominant hypercholesterolemia, and recent data indicate that the PCSK9 gene is involved in cholesterol biosynthesis. Mutations within this gene have previously been found to segregate with hypercholesterolemia. In this study, DNA sequencing of the 12 exons of the PCSK9 gene has been performed in 51 Norwegian subjects with a clinical diagnosis of familial hypercholesterolemia where mutations in the low-density lipoprotein receptor gene and mutation R3500Q in the apolipoprotein B-100 gene had been excluded. Two novel missense mutations were detected in the catalytic subdomain of the PCSK9 gene. Two patients were heterozygotes for D374Y, and one patient was a double heterozygote for D374Y and N157K. D374Y segregated with hypercholesterolemia in the two former families where family members were available for study. Our findings support the notion that mutations in the PCSK9 gene cause autosomal dominant hypercholesterolemia.
TrkC plays an essential role in breast tumor growth and metastasis (2010)

Tropomyosin-related kinase (Trk) C, a member of the Trk family of neurotrophin receptors, has been implicated in the growth and survival of human cancer tissues. Here, we report that TrkC is frequently overexpressed in human breast cancers and plays an essential role in tumor growth and metastasis. Ectopic expression of TrkC in non-malignant mammary epithelial cells suppressed anoikis, which correlated with activation of the Ras-mitogen-activated protein kinase and phosphatidylinositol-3-OH kinase (PI3K)/Akt pathways, and reduced expression of the metastatic regulator Twist. Furthermore, suppression of TrkC expression in highly metastatic mammary carcinoma cells inhibited their growth in vitro, as well as their ability to metastasize from the mammary gland to the lung in vivo. These results have identified TrkC as a critical regulator of breast cancer cell growth and metastasis.
Synthesis, Structure, and Metalation of Two New Highly Porous Zirconium Metal–Organic Frameworks (2012)

Three new metal-organic frameworks [MOF-525, Zr(6)O(4)(OH)(4)(TCPP-H(2))(3); MOF-535, Zr(6)O(4)(OH)(4)(XF)(3); MOF-545, Zr(6)O(8)(H(2)O)(8)(TCPP-H(2))(2), where porphyrin H(4)-TCPP-H(2) = (C(48)H(24)O(8)N(4)) and cruciform H(4)-XF = (C(42)O(8)H(22))] based on two new topologies, ftw and csq, have been synthesized and structurally characterized. MOF-525 and -535 are composed of Zr(6)O(4)(OH)(4) cuboctahedral units linked by either porphyrin (MOF-525) or cruciform (MOF-535). Another zirconium-containing unit, Zr(6)O(8)(H(2)O)(8), is linked by porphyrin to give the MOF-545 structure. The structure of MOF-525 was obtained by analysis of powder X-ray diffraction data. The structures of MOF-535 and -545 were resolved from synchrotron single-crystal data. MOF-525, -535, and -545 have Brunauer-Emmett-Teller surface areas of 2620, 1120, and 2260 m(2)/g, respectively. In addition to their large surface areas, both porphyrin-containing MOFs are exceptionally chemically stable, maintaining their structures under aqueous and organic conditions. MOF-525 and -545 were metalated with iron(III) and copper(II) to yield the metalated analogues without losing their high surface area and chemical stability.
Effect of Anxiolytics on Cognitive Flexibility in Problem Solving (2004)

Therefore, this suggests that the phenomenon of noradrenergic modulation of cognitive flexibility does not result from a nonspecific anxiolytic effect, but rather is specific to the noradrenergic system.
Narrow inhomogeneous and homogeneous optical linewidths in a rare earth doped transparent ceramic (2013)

Inhomogeneous and homogeneous linewidth are reported in a Eu${}^{3+}$ doped transparent Y${}_{2}$O${}_{3}$ ceramic for the ${}^{7}$F${}_{0}$-${}^{5}$D${}_{0}$ transition, using high-resolution coherent spectroscopy. The 8.7-GHz inhomogeneous linewidth is close to that of single crystals, as is the 59-kHz homogeneous linewidth at 3 K (${T}_{2}$ $=$ 5.4 $\ensuremath{\mu}$s). The homogeneous linewidth exhibits a temperature dependence that is typical of a crystalline environment, and additional dephasing observed in the ceramic is attributed to magnetic impurities or defects introduced during the synthesis process. The absence of Eu${}^{3+}$segregation at the grain boundaries, evidenced through confocal microfluorescence, further indicates that the majority of Eu${}^{3+}$ions in the ceramic experience an environment comparable to a single crystal. The obtained results suggest that ceramic materials can be competitive with single crystals for applications in quantum information and spectral hole burning devices, beyond their current applications in lasers and scintillators.
Nucleic acid related compounds. 38. Smooth and high-yield iodination and chlorination at C-5 of uracil bases and p-toluyl-protected nucleosides (1982)

Treatment of uracil bases and protected nucleosides with iodine monochloride (ICl) gave the corresponding 5-iodouracil products in over 95% purified yields. Analogously facile chlorination was effected with iodobenzene dichloride (PhICl 2 ). Protection of the nucleosides as p-toluyl esters provided reactants that were soluble in organic solvents and crystallized readily in high yields.
Induction of Insulin Resistance In Vivo by Amylin and Calcitonin Gene–Related Peptide (1990)

During hyperinsulinemic glucose-clamp studies, intravenous infusion of calcitonin gene-related peptide (CGRP) in rats antagonized the ability of insulin to stimulate peripheral glucose disposal by 52% (196 +/- 7.2 vs. 105 +/- 10.5 mumol.kg-1.min-1, P less than 0.05) and to inhibit hepatic glucose output by 54% (P less than 0.01). CGRP also inhibited the in vitro effects of insulin to stimulate hexose uptake in cultured BC3H1 myocytes at all insulin concentrations studied. Amylin is a peptide isolated from amyloid deposits in pancreatic islets of type II (non-insulin-dependent) diabetic subjects, is present in normal beta-cells, and bears a striking homology to CGRP. When synthetic human amylin was infused during clamp studies, it inhibited the ability of insulin to stimulate glucose disposal by 56% (96.9 +/- 9.4 vs. 42.4 +/- 5.0 mumol.kg-1.min-1, P less than 0.05) and to suppress hepatic glucose output by 64%. Therefore, amylin and CGRP can cause insulin resistance in vivo and may be implicated in insulin-resistant states such as type II diabetes mellitus.
ChemInform Abstract: The Boronic Acid Mannich Reaction: A New Method for the Synthesis of Geometrically Pure Allylamines. (1993)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Murine hematopoietic stem cells change their surface phenotype during ex vivo expansion (2005)

Abstract Ex vivo expansion of hematopoietic stem cells (HSCs) is important for many clinical applications, and knowledge of the surface phenotype of ex vivo–expanded HSCs will be critical to their purification and analysis. Here, we developed a simple culture system for bone marrow (BM) HSCs using low levels of stem cell factor (SCF), thrombopoietin (TPO), insulin-like growth factor 2 (IGF-2), and fibroblast growth factor-1 (FGF-1) in serum-free medium. As measured by competitive repopulation analyses, there was a more than 20-fold increase in numbers of long-term (LT)–HSCs after a 10-day culture of total BM cells. Culture of BM “side population” (SP) cells, a highly enriched stem cell population, for 10 days resulted in an approximate 8-fold expansion of repopulating HSCs. Similar to freshly isolated HSCs, repopulating HSCs after culture were positive for the stem cell markers Sca-1, Kit, and CD31 and receptors for IGF-2. Surprisingly, prion protein and Tie-2, which are present on freshly isolated HSCs, were not on cultured HSCs. Two other HSC markers, Endoglin and Mpl, were expressed only on a portion of cultured HSCs. Therefore, the surface phenotype of ex vivo–expanded HSCs is different from that of freshly isolated HSCs, but this plasticity of surface phenotype does not significantly alter their repopulation capability.
Phosphorylation of human erythrocyte band 3 by endogenous p72syk. (1994)

The anion transporter, band 3, is the major tyrosine kinase substrate in both red cell membranes and intact human erythrocytes. Using antibodies to various protein-tyrosine kinases, we found that p72syk and p56/53lyn are present in human red cells, while p56lck, pp60src, p59fyn, and p55blk are absent. Treatment of intact red cells with a combination of vanadate and hydrogen peroxide dramatically increased the tyrosine phosphorylation of band 3. This treatment increased the tyrosine kinase activity of p72syk and decreased the activity of p56/53lyn in immune complex kinase assays. Band 3 was found to be associated in immune complexes with p72syk but not with p56/53lyn. These findings suggest that p72syk is responsible, at least in part, for the tyrosine phosphorylation of band 3 in human erythrocytes.
Asymmetric synthesis of ß-amino acids and α-substituted β-amino acids (1996)

This review is intended to give a brief summary of some of the more recent developments in the synthesis of p-amino acids and asubstituted amino acids. The first part is concerned with an overview of the naturally occurring compounds containing p-amino acids. The second part summarises results on the synthesis of natural and unnatural p-amino acids, by routes involving the enzymatic resolution of racemic mixtures, the intermediary preparation of perhydropyrimidin-4-ones and the conjugate addition of ammonia equivalents to a, P-unsaturated esters and imides which are all topics near to the scientific interest of the authors. For a more complete overview of the methods developed to obtain enantiomerically pure p-amino acids, including hydrogenation of 3-aminoacrylates and nucleophilic addition of enolates to imines, see two recent excellent reviews.
Automatic Text Summarization (2008)

This work proposes an approach to address automatic text summarization. This approach is a trainable summarizer, which takes into account several features, including sentence position, positive keyword, negative keyword, sentence centrality, sentence resemblance to the title, sentence inclusion of name entity, sentence inclusion of numerical data, sentence relative length, Bushy path of the sentence and aggregated similarity for each sentence to generate summaries. First we investigate the effect of each sentence feature on the summarization task. Then we use all features score function to train genetic algorithm (GA) and mathematical regression (MR) models to obtain a suitable combination of feature weights. The proposed approach performance is measured at several compression rates on a data corpus composed of 100 English religious articles. The results of the proposed approach are promising.
Segmentation and length measurement of the abdominal blood vessels in 3-D MRI images (2009)

In diagnosing diseases and planning surgeries the structure and length of blood vessels is of great importance. In this research we develop a novel method for the segmentation of 2-D and 3-D images with an application to blood vessel length measurements in 3-D abdominal MRI images. Our approach is robust to noise and does not require contrast-enhanced images for segmentation. We use an effective algorithm for skeletonization, graph construction and shortest path estimation to measure the length of blood vessels of interest.