gebhart/patrepeval huggingface dataset:
Factors influencing flip angle mapping in MRI: RF pulse shape, slice‐select gradients, off‐resonance excitation, and B0 inhomogeneities (2006)

To understand the various effects that influence actual flip angles, and correct for these effects, it is important to precisely quantify the MRI parameters (such as T1, T2, and perfusion). In this paper actual flip angle maps are calculated using a conventional gradient-echo (GRE) sequence with different radiofrequency (RF) pulse shapes (Gaussian, sinc, and truncated-sinc), slice-selection gradients, off-resonance excitations, and B0 field inhomogeneities. The experimental results demonstrate that RF pulse shapes significantly affect the flip angle distribution and calibration factors. Off-resonance RF excitations, B0 nonuniformities, and slice-selection gradients can lead to degradations in the signal intensities of the images used to map the flip angle, and potentially introduce a bias and increased variance in the measured flip angles.
Drug-induced myasthenic syndromes. (1984)

More than 40 drugs are known to increase muscle relaxation, to aggravate myasthenia gravis, or to induce myasthenic syndromes in "normal" individuals with or without a known impaired safety factor. Many of these drugs have been known for a long time. In the last ten years some other drugs have been added to the long list: Penicillamine, beta-adrenergic blockers, carnitine, some antibiotics, lithium carbonate, catharactics containing magnesium salts, etc. An immunological basis for the penicillamine-induced myasthenia gravis is generally approved, but there may be other examples such as trimethadione and phenytoin. The knowledge of these possible side effects is important for the interpretation of unwanted effects, particularly diplopia and other mild myasthenic symptoms.
Cx43 Hemichannels and Gap Junction Channels in Astrocytes Are Regulated Oppositely by Proinflammatory Cytokines Released from Activated Microglia (2007)

Astrocytes have a role in maintaining normal neuronal functions, some of which depend on connexins, protein subunits of gap junction channels and hemichannels. Under inflammatory conditions, microglia release cytokines, including interleukin-1beta and tumor necrosis factor-alpha, that reduce intercellular communication via gap junctions. Now, we demonstrate that either conditioned medium harvested from activated microglia or a mixture of these two cytokines enhances the cellular exchange with the extracellular milieu via Cx43 hemichannels. These changes in membrane permeability were not detected in astrocytes cultured from Cx43 knock-out mice and were abrogated by connexin hemichannel blockers, including La3+, mimetic peptides, and niflumic acid. Both the reduction in gap junctional communication and the increase in membrane permeability were mediated by a p38 mitogen-activated protein kinase-dependent pathway. However, the increase in membrane permeability, but not the gap junction inhibition, was rapidly reversed by the sulfhydryl reducing agent dithiothreitol, indicating that final regulatory mechanisms are different. Treatment with proinflammatory cytokines reduced the total and cell surface Cx43 levels, suggesting that the increase in membrane permeability was attributable to an increase in hemichannels activity. Indeed, unitary events of approximately 220 pS corresponding to Cx43 hemichannels were much more frequent in astrocytes treated with microglia conditioned medium than under control conditions. Finally, the effect of cytokines enhanced the uptake and reduced the intercellular diffusion of glucose, which might explain changes in the metabolic status of astrocytes under inflammatory conditions. Accordingly, this opposite regulation may affect glucose trafficking and certainly will modify the metabolic status of astrocytes involved in brain inflammation.
Early Changes in Quiescent B Cell Physiology Subsequent to Cognate and Bystander Interaction with Helper T Cells (1988)

We have assessed early changes in quiescent B cells following cognate and bystander interaction with cloned helper T cells. Variables monitored include Ia expression, blastogenesis, G0 to G1 transition, and progression through cycle. We have also assessed the antigen specificity, Ia restriction, and dependence on membrane immunoglobulin crosslinking of both generation and delivery of effectors that mediate B cell responses. The results demonstrate that antigen presentation by quiescent B cells to T cells resulting in the generation of effectors that activate B cells is Ia-restricted and dependent on antigen and an (mIgM and mIgD) crosslinking signal. However, once generated, T cell effector functions act independently of Ia haplotype to promote Ia expression, blastogenesis, and G0 to G1 transition by most small B cells. Although these responses can be mediated by T cell supernatants, further progression of B cells through S, G2 and M is only efficient when Th cells are present in cultures. Thus, results suggest that one or more Ia unrestricted, labile and/or cell-associated factors, not active in most conventional T cell supernatants, are necessary to stimulate proliferation of small B cells.
Characterization of Two Types of Endothelial Progenitor Cells and Their Different Contributions to Neovasculogenesis (2003)

We found two types of EPC from a source of adult peripheral blood that might have different roles in neovasculogenesis based on the identified differences.
Chirp-free transmission over 82.5 km of single mode fibers at 2 Gbit/s with injection locked DFB semiconductor lasers (1985)

The spectral and modulation characteristics of injection locked distributed feedback lasers operating at 1.5-μm wavelength have been investigated. The total elimination of excess chirp in directly modulated lasers by the injection locking technique has allowed us to perform transmission experiments over 82.5 km of single mode fibers at 2 Gbit/s without any measurable penalty related to dispersion. Device design parameters for efficient chirp suppression are also given.
Ligand-independent and -dependent Functions of Thyroid Hormone Receptor Isoforms Depend upon Their Distinct Amino Termini (1995)

Isoform specificity likely plays a large role in the ability of the thyroid hormone receptor (TR) to specifically regulate gene expression in both the presence and absence of its cognate ligand, triiodothyronine. To investigate further the mechanism of isoform specificity of human TRs (TR alpha 1 and TR beta 1), we have examined their functional effects on positive thyroid hormone response elements (TREs) both in the presence and absence of ligand. TR alpha 1 was greater than 2-fold more potent than TR beta 1 on both TREs studied, in terms of both ligand-independent repression and ligand-dependent stimulation. By creating a number of chimeric and mutant receptors, we have established that the increased functional potency of TR alpha 1 is due to its unique amino terminus. Deletion or substitution of the TR alpha 1 amino terminus leads to a loss of both its ligand-independent and -dependent functions on positive TREs. Furthermore, the TR alpha 1 amino terminus antagonizes homodimer formation on the positive TREs studied. TR constructs, which contain the TR alpha 1 amino terminus, are unable to form homodimers and form exclusively heterodimers with RXR alpha on direct repeat and palindromic TREs. Deletion of the amino terminus from either TR isoform leads to preferential homodimer formation, which suggests that the TR amino terminus is important for relative heterodimerization capability. From these data, we conclude that TR alpha 1 isoform specificity on positive TREs resides predominantly in its amino terminus through its ability to favor heterodimerization with the retinoid X receptor or other nuclear proteins.
Characterization of the Thermus thermophilus locus encoding peptide deformylase and methionyl-tRNA(fMet) formyltransferase (1994)

An Escherichia coli strain with thermosensitive expression of the gene encoding peptide deformylase (fms) has been constructed. At nonpermissive temperatures, this strain fails to grow. The essential character of the fms gene was further used to clone by heterologous complementation the locus corresponding to Thermus thermophilus peptide deformylase. The cloned fragment also carries the methionyl-tRNA(fMet) formyltransferase gene (fmt). It is located immediately downstream from the fms gene, as in E. coli. Further sequence analysis of the region surrounding the E. coli fms-fmt locus indicates that the genes bordering the fms-fmt region are not conserved in T. thermophilus.
A toolbox for power system dynamics and control engineering education and research (1992)

The design concept and use of the power system toolbox (PST), a Matlab-based power system dynamics simulation and control design package, are discussed. The motivation for developing the package was to provide a flexible environment for teaching power system simulation techniques and control design concepts to advanced undergraduate and graduate students, and for graduate students to perform research and development on power systems. The authors discuss the capabilities of PST and the software development philosophy. Sample applications are given. Some potential educational usage is suggested. The future enhancement to the package is outlined.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Kinetic analysis of the interaction between the monoclonal antibody A33 and its colonic epithelial antigen by the use of an optical biosensor (1997)

The interaction between the humanised A33 monoclonal antibody and the corresponding F(ab)'2 or Fab' fragments with the colonic epithelial A33 antigen, purified by micropreparative HPLC from membrane extracts of the colonic carcinoma cell line LIM 1215, has been studied with the BIAcore 2000 biosensor using surface plasmon resonance detection. The surface orientation of immobilised antibody and the Fab' fragment onto the biosensor surface was controlled using alternative immobilisation chemistries. This resulted in significantly higher molar binding activities compared with the conventional N-hydroxysuccinimide (NHS)/N-ethyl-N'-dimethylaminopropylcarbodiimide (EDC) chemistry. This increase in signal resulted in a concomitant increase in sensitivity of detection, which facilitates analysis of low levels of A33 antigen. The apparent association rate (ka) and dissociation rate (kd) constants obtained with the different immobilisation chemistries were determined. These analyses showed that the kinetic constants obtained for the IgG were not significantly affected by the method of immobilisation. F(ab)'2 and Fab' fragments immobilised using NHS/EDC chemistry showed significantly lower apparent affinity. By contrast the use of the thiol coupling chemistry with the Fab' fragment gave a five fold increase in observed KA, resulting in a similar affinity to that observed with the intact IgG molecule.
Time-evolution of in vivo protein corona onto blood-circulating PEGylated liposomal doxorubicin (DOXIL) nanoparticles (2016)

Nanoparticles (NPs) are instantly modified once injected in the bloodstream because of their interaction with the blood components. The spontaneous coating of NPs by proteins, once in contact with biological fluids, has been termed the 'protein corona' and it is considered to be a determinant factor for the pharmacological, toxicological and therapeutic profile of NPs. Protein exposure time is thought to greatly influence the composition of protein corona, however the dynamics of protein interactions under realistic, in vivo conditions remain unexplored. The aim of this study was to quantitatively and qualitatively investigate the time evolution of in vivo protein corona, formed onto blood circulating, clinically used, PEGylated liposomal doxorubicin. Protein adsorption profiles were determined 10 min, 1 h and 3 h post-injection of liposomes into CD-1 mice. The results demonstrated that a complex protein corona was formed as early as 10 min post-injection. Even though the total amount of protein adsorbed did not significantly change over time, the fluctuation of protein abundances observed indicated highly dynamic protein binding kinetics.
Mechanisms controlling volume change of saturated clays and the role of the effective stress concept (1973)

Synopsis This investigation deals with the mechanisms con- trolling the one-dimensional volume change beha- viour of saturated kaolinite and montmorillonitic clays. An attempt has been made to explain the behaviour of the clays in the light of the modified effective stress concept which takes into considera- tion the interparticle electrical attractive and repul- sive forces. Eight organic pore fluids of different dielectric properties and water have been used to vary the interparticle forces in the one-dimensional consolidation tests. In order to further confirm the nature of the mechanisms, tests have also been con- ducted in which the existing pore fluid was replaced by another of different dielectric properties, to change the force system at interparticle level. The experimental results clearly indicate that the volume change behaviour of these clays is controlled basi- cally by two mechanisms which are governed by the modified effective stress concept. In mechanism 1, the volume change is controlled by the shearing resistance at interparticle level and in mechanism 2, primarily by the long range diffuse double layer repulsive forces. Although these effects operate simultaneously, the results indicate that mechanism 1 primarily governs the volume change behaviour of non-expanding lattice type clays like kaolinite, and mechanism 2, that of the expanding lattice type clays like montmorillonite. On étudie les mécanismes qui régissent le comportement au tours du changement de volume unidimensionel d'argiles à kaolinite et à montmorillonite saturées. On essaye d'expliquer le comportement de ces argiles en fonction du concept de contrainte effective modifiée, qui tient compte des forces électriques d'attraction et de répulsion. On s'est servi de huit fluides interstitiels organiques ayant des propriétés diélectriques différentes, ainsi que de I'eau, pour faire varier ces forces entre particules dans des essais de consolidation unidimensionelle. Pour confirmer la nature de ces mécanismes, on a également fait des essais au tours desquels le fluide interstitiel existant a été remplacé par un autre fluide ayant des propriétés diélectriques différentes, pour changer le système de forces au niveau des particules. Les résultats expérimentaux indiquent clairement que le comportement au tours du changement de volume de ces argiles dépend essentiellement de deux mécanismes qui sont régis par le concept de contrainte effective modifiee. Dans le premier mécanisme, le changement de volume est régi par la résistance au cisaillement au niveau des particules et dans le second mécanisme, par des forces de répulsion à plus grande distance dans la double couche diffuse. Bien que ces effets aient lieu en même temps, les résultats indiquent que le premier mécanisme régit principalement le changement de volume du type d'argiles à réseau non dilatant, comme la kaolinite, et le second mécanisme celui du type d'argiles à réseau dilatant comme la montmorillonite.
A Practical Synthesis of Multifunctional Ketones through the Fukuyama Coupling Reaction (2007)

Abstract A highly efficient, robust and scalable protocol for the synthesis of multifunctional ketones through Fukuyama coupling, i.e., cross‐coupling of thiol esters with zinc reagents, has been developed. Treatment of thiol esters with alkylzinc iodides or dialkyl zincs in the presence of palladium on activated carbon (Pd/C) or palladium acetate [Pd(OAc) 2 ] furnished the corresponding ketones in high yields. Evaluation of the properties‐activities relationship of the Pd/C‐catalyzed reaction has proven that oxidic Pd/C is much more potent than reduced Pd/C in the reaction of thiolactone 1a with zinc reagent 2a . Based on the dependence of the Pd/C‐catalyzed reaction on the nature of Pd/C in combination with the extent of the Pd leaching from Pd/C to the solution, a dual reaction mechanism for the Pd/C‐catalyzed Fukuyama coupling reaction, which includes heterogeneous and homogeneous catalytic cycles, was proposed. The marked reduction of the zinc reagents and the use of Pd(OAc) 2 in much smaller amounts were achieved when zinc bromide was added. This supports a hypothesis where a shift of the Schlenk equilibrium from inactive dialkylzincs (R 2 Zn) to active organozinc species, such as alkylzinc halides (RZnX) and three‐coordinate species [(RZnX 2 ) − ⋅ (ZnX) + ], and generation of the stabilized monomeric Pd complexes during the reaction, may facilitate the reaction.
Ultrafast correlation image sensor: concept, design, and applications (2002)

This paper proposes a new type of image sensor on which correlation detectors between incident lights and electronic signals are integrated as a 2-D array. This architecture is characterized by: 1) photodiodes for converting incident photons to currents (multiplicands), 2) one or a few external electric signals (multipliers) which are common to all pixels, 3) multipliers of the photo currents and the external signals, 4) capacitors for accumulating the products as the correlation results, and 5) CCD or MOS switching networks for scanning out the correlation results. Several design and applications of the sensor are demonstrated.
Sequence and Spacing of TATA Box Elements Are Critical for Accurate Initiation from the β-Phaseolin Promoter (2004)

The beta-phaseolin (phas) gene, which encodes one of the major seed storage proteins of P. vulgaris, is tightly regulated at the transcription level resulting in strict tissue-specific and spatial expression during embryonic development. The phas proximal promoter contains a complex arrangement of core promoter elements including three TATA boxes as well as several putative initiator elements. To delineate the respective contributions of the core promoter elements to transcription initiation we have performed site-directed mutagenesis of the phas promoter. In vivo expression studies were performed on transgenic Arabidopsis harboring phas promoter mutants driving expression of the beta-glucuronidase (gus) reporter gene. Quantitative assessment of GUS activity in seeds bearing the promoter mutants indicated that both sequence and spacing of the TATA elements influenced the efficiency of transcription. Substitution, insertion or deletion mutations had no effect on histochemical staining patterns indicating that strict spacing requirements are not essential for correct spatial expression of phas during embryogenesis. Further evaluation of the phas promoter by in vitro transcription analysis revealed the presence of multiple TATA-dependent transcription initiation start sites. The distance between TATA elements and transcription start sites was maintained in insertion and deletion mutants through the creation of novel initiation sites, indicating that positioning of the TATA elements rather than DNA sequence was the primary determinant of start site location. We conclude that, while dispensable for proper spatial distribution, the complex architecture of the phas promoter is required to ensure high levels of accurate phas transcription initiation in the developing embryo.
Gene Inactivation of Proprotein Convertase Subtilisin/Kexin Type 9 Reduces Atherosclerosis in Mice (2012)

Altogether, our results show a direct relationship between PCSK9 and atherosclerosis. PCSK9 overexpression is proatherogenic, whereas its absence is protective.
Inhibition of tumor cell growth by RTP/rit42 and its responsiveness to p53 and DNA damage. (1998)

Through a differential screening technique, we have identified a cDNA clone with differential expression in normal versus tumor cells. This clone, designated rit42 (reduced in tumor, 42 kDa), was previously isolated as a homocysteine-inducible gene in human endothelial cells (RTP), and the same or a highly related androgen-responsive gene in mouse has also been identified. Both Northern blot analysis and in situ hybridization demonstrated a significantly diminished expression in tumor cells, including those derived from breast and prostate when compared with normal cells. It was shown that RTP/rit42 mRNA cycles with cell division, peaking at G1 and G2-M, with lower expression in S phase. The biphasic expression of RTP/rit42 mRNA was absent in tumor cells. Introduction of rit42 cDNA into human cancer cells reduced cell growth both in vitro and in nude mice. Moreover, analysis of a tetracycline-regulated p53-inducible system in null-p53 cell lines showed that RTP/rit42 mRNA expression increased concomitantly with p53 expression and followed a similar time course. In addition, DNA-damaging agents induced RTP/rit42 expression in a p53-dependent manner but independent of a p53-mediated G1 arrest. Immunofluorescence analysis of a FLAG epitope-tagged RTP/rit42 protein revealed a cytoplasmic localization pattern with redistribution to the nucleus upon DNA damage. We have localized RTP/rit42 to human chromosome 8q24.3. Taken together, these results are consistent with a growth inhibitory role for RTP/rit42, and its down-regulation may contribute to the tumor malignant phenotype.
Cloning of the human eosinophil chemoattractant, eotaxin. Expression, receptor binding, and functional properties suggest a mechanism for the selective recruitment of eosinophils. (1996)

The CC chemokine eotaxin, identified in guinea pigs and also recently in mice, may be a key element for the selective recruitment of eosinophils to certain inflamed tissues. Using a partial mouse eotaxin CDNA probe, the human eotaxin gene was cloned and found to be 61.8 and 63.2% identical at the amino acid level to guinea pig and mouse eotaxin. Human eotaxin protein was a strong and specific eosinophil chemoattractant in vitro and was an effective eosinophil chemoattractant when injected into the skin of a rhesus monkey. Radiolabeled eotaxin was used to identify a high affinity receptor on eosinophils (0.52 nM Kd), expressed at 4.8 x 10(4) sites per cell. This receptor also bound RANTES and monocyte chemotactic protein-3 with lower affinity, but not macrophage inflammatory protein-1 alpha. Eotaxin could desensitize calcium responses of eosinophils to RANTES and monocyte chemotactic protein-3, although RANTES was able to only partially desensitize eosinophil calcium responses to eotaxin. Immunohistochemistry on human nasal polyp with antieotaxin mAbs showed that certain leukocytes as well as respiratory epithelium were intensely immunoreactive, and eosinophil infiltration occurred at sites of eotaxin upregulation. Thus eotaxin in humans is a potent and selective eosinophil chemoattractant that is expressed by a variety cell types in certain inflammatory conditions.
Efficient scan operators for bit-serial processor arrays (2003)

A fast algorithm is presented for broadcasting a word of length w on an n*n single-instruction multiple-data (SIMD) array of bit-serial processing elements, in time O(n+w). Data-skewing problems caused by SIMD restrictions are solved by assuming that each processing element contains a shift register and an activity flag that allows each processing element to conditionally ignore instructions. The broadcasting algorithm is then extended to a fast segmented-scan (prefix) algorithm that runs in time O(n+(w+t)log n), where t is the time needed to perform the arbitrary, user-defined operation on which the scan is based. Because of the versatility of scan operations, many algorithms written for more powerful SIMD computers, such as the connection machine, can easily be adapted to bit-serial arrays. Slightly less efficient algorithms are also presented for processing elements that lack shift registers.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>