gebhart/patrepeval huggingface dataset:
Some biomedical applications of ferrofluids (1999)

Ferrofluids are colloidal solutions of iron oxide magnetic nanoparticles in either a polar or no polar liquid. We present here two biological applications using maghemite (γFe2O3) ferrofluids: magnetic cell sorting and magnetocytolysis. The first application employs magnetic particles binding a biological effector, which is capable to recognize the target cells specifically. These cells become magnetic and can be sorted in a gradient of magnetic field. We describe first the various steps of the synthesis of a biocompatible ferrofluid and the grafting an effector protein onto the particles. We then describe the use of particles carrying annexin V in the separation and quantification of damaged erythrocytes in blood samples. This very sensitive technique can be used to follow the erythrocytes ageing of normal blood samples during their storage under blood bank conditions or to detect the membrane modifications that are associated with some pathologies such as malaria or Alzheimer's disease. The dependence of the magnetic susceptibility versus the frequency is a way to transform magnetic energy into thermal energy. Magnetocytolysis is the destruction of cells, carrying magnetic particles, through the action of an alternating magnetic field (about 1 MHz). We present here preliminary experiments with macrophages, which demonstrate the method's feasibility and the formation of the non-specific interactions between the cells and the magnetic particles.
Tribology of Langmuir-Blodgett layers (1989)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTribology of Langmuir-Blodgett layersV. Novotny, J. D. Swalen, and J. P. RabeCite this: Langmuir 1989, 5, 2, 485–489Publication Date (Print):March 1, 1989Publication History Published online1 May 2002Published inissue 1 March 1989https://pubs.acs.org/doi/10.1021/la00086a034https://doi.org/10.1021/la00086a034research-articleACS PublicationsRequest reuse permissionsArticle Views159Altmetric-Citations53LEARN 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 Get e-Alerts
2-Phosphoglycerate phosphatase and serine biosynthesis in Veillonella alcalescens (1981)

The constituent enzymes for the phosphorylated and nonphosphorylated serine biosynthetic pathways in Veillonella alcalescens were identified and included phosphoserine phosphatase, 3-phosphoglycerate dehydrogenase, glycerate dehydrogenase, phosphoserine aminotransferase, and serine-pyruvate aminotransferase. Cell extracts of the organism were also found to cause the specific dephosphorylation of 2-phosphoglycerate. The phosphatase was purified 39-fold by manganese chloride precipitation, ammonium sulfate precipitation, and DEAE-cellulose chromatography. Sephadex G-200 gel filtration data established an apparent molecular weight of 50000 for the enzyme. The 2-phosphoglycerate phosphatase had a pH optimum of 5.5 and was distinct from phosphoglyceromutase. Assays conducted with the purified enzyme on a number of other phosphorylated intermediates indicated that the phosphatase was most specific for 2-phosphoglycerate. Glucerate, hydroxypyruvate, and serine inhibited the enzyme, whereas succinate stimulated activity. Veillonella 2-phosphoglycerate phosphatase is the first such enzyme to be described in a prokaryote and is probably involved in glycerate generation for the nonphosphorylated serine biosynthetic pathway.
Genetic and molecular analysis of a Caenorhabditis elegans beta-tubulin that conveys benzimidazole sensitivity. (1989)

Benzimidazole anti-microtubule drugs, such as benomyl, induce paralysis and slow the growth of the nematode Caenorhabditis elegans. We have identified 28 mutations in C. elegans that confer resistance to benzimidazoles. All resistant mutations map to a single locus, ben-1. Virtually all these mutations are genetically dominant. Molecular cloning and DNA sequence analysis established that ben-1 encodes a beta-tubulin. Some resistant mutants are completely deleted for the ben-1 gene. Since the deletion strains appear to be fully resistant to the drugs, the ben-1 product appears to be the only benzimidazole-sensitive beta-tubulin in C. elegans. Furthermore, since animals lacking ben-1 are viable and coordinated, the ben-1 beta-tubulin appears to be nonessential for growth and movement. The ben-1 function is likely to be redundant in the nematode genome.
Toll-Like Receptor Signaling Pathways (2003)

Members of the Toll-like receptor (TLR) family recognize conserved microbial structures, such as bacterial lipopolysaccharide and viral double-stranded RNA, and activate signaling pathways that result in immune responses against microbial infections. All TLRs activate MyD88-dependent pathways to induce a core set of stereotyped responses, such as inflammation. However, individual TLRs can also induce immune responses that are tailored to a given microbial infection. Thus, these receptors are involved in both innate and adaptive immune responses. The mechanisms and components of these varied responses are only partly understood. Given the importance of TLRs in host defense, dissection of the pathways they activate has become an important emerging research focus. TLRs and their pathways are numerous; Science's Signal Transduction Knowledge Environment's TLR Connections Map provides an immediate, clear overview of the known components and relations of this complex system.
Novel micromechanical bulk acoustic wave resonator sensing concepts for advanced atomic force microscopy (2012)

This thesis investigates novel concepts of micromechanical bulk acoustic wave sensors for advanced atomic force microscopy (AFM), using micromachined silicon resonators, which are analyzed with regard to their performance as compared to conventional AFM sensors. Conventional AFM systems use a cantilever resonator for sensing the surface forces of the sample. Since a laser is used to detect the cantilevers movement, a certain minimum area for reflecting the laser beam is required. These restrictions in the cantilever scalability limits the resonant frequency and quality factor of the resonator and thus the overall performance and resolution of a conventional AFM system. To overcome these limitations and to improve atomic force microscopy, new sensor concepts are proposed. First an analysis of different extensional mode resonator geometries is conducted to determine the dependency of the shape and dimensions on the stiffness, resonant frequency and displacement for the use as AFM sensor. Based on that a two resonator system is introduced, consisting of a flexural mode resonator acting as sensing unit with design specifications oriented on an AFM cantilever and of an additional bulk mode resonator with high resonant frequency and high quality factor detecting the movement of the first resonator. They are coupled electrostatically, where a DC potential between the two resonators and a variation in gap width, caused by the oscillation of the flexural mode resonator, modulate the pre-stress in the bulk mode resonator resulting in a frequency shift, which is then detected capacitively. Finite-element simulations are conducted to determine the sensitivity of the system for different resonator geometries, dimensions and DC potentials between the two resonators, as well as the thermal noise and thus the detection limit of the system. As a second design, a variation of the existing sensor is proposed using a mechanical spring system to couple the two resonators. The benchmark criteria of these novel concepts is that it should be possible to detect a force in the range of the Brownian motion at room temperature. Summarizing the results it can be concluded that a ring shaped geometry is the most suitable for a single bulk acoustic wave resonator sensor for AFM applications, as it achieves highest displacement for a given size, resonant frequency and quality factor. These findings can also be used to improve the electrostatically coupled resonator system and to reduce the DC potential needed between the two resonators to avoid pull-in and at the same time still achieve good sensor sensitivity.
The Neuromodulatory System: A Framework for Survival and Adaptive Behavior in a Challenging World (2008)

Biological organisms have the ability to respond quickly to an ever-changing world. Because this adaptability is so critical for survival, all vertebrates have sub-cortical structures, which comprise the neuromodulatory systems, to regulate fundamental behavior and drive decision making in response to environmental events. In the vertebrate, there are separate neuromodulators that respond to threats, reward anticipation, novelty, and attentional effort. However, each of these neuromodulatory systems has a similar effect, that is, to cause an organism to be decisive when environmental conditions call for such actions, and allow the organism to be more exploratory when there are no pressing events. In this article, it is proposed that principles of the neuromodulatory system could provide a framework for controlling artificial agents that may improve current artificial agent behavior. These agents would operate autonomously, effectively explore their environment, and be decisive when environmental conditions call for action.
Low-cost VCSEL-transceiver module for optical data busses (2002)

We have proposed and demonstrated a new low-cost, low insertion loss and compact optical transceiver module for optical data busses with reflective star topology. System experiments show the feasibility of these modules as transceivers in control data busses for mobile systems. We believe that the described mounting technique can also be applied to 50/125 /spl mu/m and 62.5/125 /spl mu/m silica and to plastic optical fiber based systems.
YBCO-coated conductors fabricated by inclined substrate deposition technique (2004)

Inclined substrate deposition (ISD) is an attractive technique for rapid production of high-quality template layers for YBCO-coated conductors. We have grown biaxially textured magnesium oxide (MgO) films on metallic substrates by ISD at rapid deposition rates, 20–100 A s−1. Scanning electron microscopy of the ISD MgO films showed columnar grain structures with a roof-tile-shaped surface. X-ray diffraction pole figure analysis revealed that the ISD MgO film is biaxially aligned with the c-axis tilted from its substrate normal. Tilt angles of and were measured on ISD MgO films deposited at 55° and 35° inclination angles, respectively. A full width at half maximum (FWHM) of was observed in the -scan for short-length ISD MgO films. A 1 m long tape of ISD MgO grown on a metallic substrate was fabricated by a reel-to-reel method. This tape has an average -scan FWHM of 16.1° with a standard deviation of 2.6°. YBCO films were grown on strontium ruthenium oxide (SRO)-buffered ISD MgO substrates by pulsed laser deposition. A superconducting critical transition temperature Tc = 91 K and critical current density Jc = 1.1 × 106 A cm−2 were measured at 77 K in self-field for a sample that is 0.3 µm thick, 2.9 mm wide, and 1.0 cm long.
Trans-dominant Tat mutants with alterations in the basic domain inhibit HIV-1 gene expression. (1991)

The Tat protein of the human immunodeficiency virus type 1 (HIV-1) is required for efficient viral gene expression. By means of mutational analyses, several domains of the Tat protein that are required for complete activation of HIV-1 gene expression have been defined. These include an amino-terminal activating domain, a cysteine-rich dimerization domain, and a basic domain important in the binding of Tat to the trans-activation response element (TAR) and in Tat nuclear localization. Recently, we described a mutation, known as delta tat, which resulted in a protein with a truncated basic domain. This protein had a "trans-dominant" phenotype in that it inhibited wild-type Tat activation of the HIV-1 LTR. To further characterize the requirements for generating a Tat trans-dominant phenotype, we constructed a variety of Tat proteins with truncations or substitutions in the basic domain. A number of these proteins showed a trans-dominant phenotype. These Tat mutants also inhibited activation of the HIV-1 LTR by a protein composed of Tat fused to the prokaryotic R17 (phage MS2) RNA-binding protein in which the R17 recognition element was inserted in the HIV-1 LTR in place of TAR. Thus, an intact TAR element was not required for this inhibition. We also studied the cellular localization of Tat and a trans-dominant Tat mutant by means of immunofluorescence staining with the use of antibodies reactive to different domains of the Tat protein. The results indicated that Tat becomes localized predominantly in the nucleus both in the presence and absence of the trans-dominant Tat construct, suggesting that the trans-dominant mutant does not inhibit Tat nuclear localization. These studies further define the requirements for the creation of trans-dominant Tat mutants, and suggest that the mechanism of trans-dominant Tat inhibition may be either the formation of an inactive complex between wild-type and mutant Tat or sequestration of cellular factors involved in regulating HIV-1 gene expression.
New signal-processing LSIs for the 8 mm camcorder (1990)

A novel LSI chip set for the high-band 8-mm camcorder has been developed. The new LSI system has succeeded in reducing the number of peripheral parts and power consumption by 48% and 35% for the camera block, and 37% and 26% for the VCR block, as well as improving the picture quality. Using these LSIs, a compact, lightweight, low-power, and high-picture-quality Hi8 camcorder can be achieved.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Photostimulation of two types of Ca2+ wavesin rat pheochromocytoma PC12 cells by ultrashort pulsednear-infrared laser irradiation (2005)

We show that focused laser irradiation can generate Ca 2+ waves in differentiated PC12 cells, using highly penetrating and locally acting near-infrared femtosecond pulsed laser light. Similar to photolytic uncaging experiments, intracellular Ca 2+ concentrations could be elevated to produce a whole cell Ca 2+ rise, but without the requirement for caged Ca 2+ . Irradiation of subcellular volumes in the soma or in PC12 neurites generated a relatively slow calcium rise (speed ∼20 μm/s). Less frequently, a fast calcium rise (speed &gt;1200 μm/s) was observed, consistent with laser-induced membrane depolarization. The probability of Ca 2+ generation increased with laser power and was found to be the same in excitable (PC12) and non-excitable (HeLa) cells.
Maps: a compiler-managed memory system for software-exposed architectures (2000)

Microprocessors must exploit both instruction-level parallelism (ILP) and memory parallelism for high performance. Sophisticated techniques for ILP have boosted the ability of modern-day microprocessors to exploit ILP when available. Unfortunately, impro
A Novel Core Genome-Encoded Superantigen Contributes to Lethality of Community-Associated MRSA Necrotizing Pneumonia (2011)

Bacterial superantigens (SAg) stimulate T-cell hyper-activation resulting in immune modulation and severe systemic illnesses such as Staphylococcus aureus toxic shock syndrome. However, all known S. aureus SAgs are encoded by mobile genetic elements and are made by only a proportion of strains. Here, we report the discovery of a novel SAg staphylococcal enterotoxin-like toxin X (SElX) encoded in the core genome of 95% of phylogenetically diverse S. aureus strains from human and animal infections, including the epidemic community-associated methicillin-resistant S. aureus (CA-MRSA) USA300 clone. SElX has a unique predicted structure characterized by a truncated SAg B-domain, but exhibits the characteristic biological activities of a SAg including Vβ-specific T-cell mitogenicity, pyrogenicity and endotoxin enhancement. In addition, SElX is expressed by clinical isolates in vitro, and during human, bovine, and ovine infections, consistent with a broad role in S. aureus infections of multiple host species. Phylogenetic analysis suggests that the selx gene was acquired horizontally by a progenitor of the S. aureus species, followed by allelic diversification by point mutation and assortative recombination resulting in at least 17 different alleles among the major pathogenic clones. Of note, SElX variants made by human- or ruminant-specific S. aureus clones demonstrated overlapping but distinct Vβ activation profiles for human and bovine lymphocytes, indicating functional diversification of SElX in different host species. Importantly, SElX made by CA-MRSA USA300 contributed to lethality in a rabbit model of necrotizing pneumonia revealing a novel virulence determinant of CA-MRSA disease pathogenesis. Taken together, we report the discovery and characterization of a unique core genome-encoded superantigen, providing new insights into the evolution of pathogenic S. aureus and the molecular basis for severe infections caused by the CA-MRSA USA300 epidemic clone.
Fatal Familial Insomnia and Familial Creutzfeldt-Jakob Disease: Disease Phenotype Determined by a DNA Polymorphism (1992)

Fatal familial insomnia (FFI) and a subtype of familial Creutzfeldt-Jakob disease (CJD), two clinically and pathologically distinct diseases, are linked to the same mutation at codon 178 (Asn178) of the prion protein gene. The possibility that a second genetic component modified the phenotypic expression of the Asn178 mutation was investigated. FFI and the familial CJD subtype segregated with different genotypes determined by the Asn178 mutation and the methionine-valine polymorphism at codon 129. The Met129, Asn178 allele segregated with FFI in all 15 affected members of five kindreds whereas the Val129, Asn178 allele segregated with the familial CJD subtype in all 15 affected members of six kindreds. Thus, two distinct disease phenotypes linked to a single pathogenic mutation can be determined by a common polymorphism.
Genetically Engineered Fluorescent Voltage Reporters (2012)

Fluorescent membrane voltage indicators that enable optical imaging of neuronal circuit operations in the living mammalian brain are powerful tools for biology and particularly neuroscience. Classical voltage-sensitive dyes, typically low molecular-weight organic compounds, have been in widespread use for decades but are limited by issues related to optical noise, the lack of generally applicable procedures that enable staining of specific cell populations, and difficulties in performing imaging experiments over days and weeks. Genetically encoded voltage indicators (GEVIs) represent a newer alternative that overcomes several of the limitations inherent to classical voltage-sensitive dyes. We critically review the fundamental concepts of this approach, the variety of available probes and their state of development.
Transactivation of the PPAR-Responsive Enhancer Module in Chemopreventive Glutathione S -Transferase Gene by the Peroxisome Proliferator-Activated Receptor-γ and Retinoid X Receptor Heterodimer (2004)

Cancer chemopreventive agents transcriptionally induce glutathione S-transferase (GST), which can protect cells from chemical-induced carcinogenesis. Activation of either NF-E2-related factor-2 (Nrf2) or the CCAAT/enhancer binding protein-beta (C/EBPbeta) contributes to GST induction. Peroxisome proliferator-activated receptor-gamma (PPARgamma) and the retinoic acid X receptor (RXR) play roles in regulating cell differentiation and chemoprevention. This study examined GSTA2 gene induction by the PPARgamma activator and 9-cis-retinoic acid (RA), a RXR ligand, and investigated the molecular basis of PPAR-RXR-mediated GSTA2 induction in the H4IIE hepatocytes. Either 15-deoxy-delta (12, 14)-prostaglandin J(2) (PGJ(2)) or RA induced GSTA2 with Nrf2 and C/EBPbeta activation. When compared with PGJ(2) or RA alone, PGJ(2) + RA enhanced GSTA2 induction, with increases in Nrf2 and C/EBPbeta activation. PGJ(2) + RA increased the luciferase reporter gene activity in the cells transfected with the -1.65-kb flanking region of the GSTA2 gene. Thiazolidinedione PPARgamma agonists, troglitazone, rosiglitazone, and pioglitazone, in combination with RA, potentiated GSTA2 induction, confirming that the activation of the PPARgamma and RXR heterodimer contributed to GSTA2 expression. Deletion of the antioxidant response element- or C/EBP-binding sites or the overexpression of dominant-negative mutant of C/EBP abolished the reporter gene expression. PGJ2 + RA increased the binding of the PPARgamma - RXR heterodimer to the putative PPAR-response elements (PPREs) in the GSTA2 promoter. Specific mutations of these multiple PPRE sites resulted in the complete loss of its responsiveness to PGJ2 + RA, which suggests that these binding sites function as a PPRE-responsive enhancer module (PPREM). Transactivation of PPREM by the PPARgamma - RXR heterodimer was verified by the effective GSTA2 induction in the cells treated with PGJ2 + RA after transfecting them with the plasmids encoding PPARgamma1 and RXRalpha. In conclusion, the PPARgamma - RXR heterodimer promotes GSTA2 induction by activating PPREM in the GSTA2 gene, as well as inducing Nrf2 and C/EBPbeta activation.
Metabolism and excretion of nitric oxide in humans. An experimental and clinical study. (1993)

Despite the increasing insight in the clinical importance of nitric oxide (NO), formerly known as endothelium-derived relaxing factor (EDRF), there is limited information about the metabolism and elimination of this mediator in humans. We studied the degradation of NO in healthy subjects inhaling 25 ppm for 60 minutes and in patients with severe heart failure inhaling 20, 40, and 80 ppm in consecutive 10-minute periods. In other healthy subjects, the renal clearance of NO metabolite was measured. The metabolism ex vivo was evaluated by direct incubation of nitrite, the NO oxidation product, in blood from healthy humans. During inhalation of NO, the plasma levels of nitrate increased progressively, both in the healthy subjects (from 26 to 38 mumol/L, P < .001) and in the patients (from 72 to 90 mumol/L, P < .001). Methemoglobin (MetHb) also increased in the healthy subjects (from 7 to 13 mumol/L, P < .001) as well as in the patients (from 19 to 42 mumol/L, P < .01). No change in nitrosohemoglobin (HbNO) was detected, either in the healthy subjects or in the patients. In arterialized blood (O2 saturation, 94% to 99%), incubated nitrite was semiquantitatively converted to nitrate and MetHb. In venous blood (O2 saturation, 36% to 85%) moderate amounts of HbNO were also formed. Plasma and urinary clearance of nitrate in healthy subjects averaged 20 mL/min. We conclude that uptake into the red blood cells with subsequent conversion to nitrate and MetHb is a major metabolic pathway for endogenously formed NO. Nitrate may then enter the plasma to be eliminated via the kidneys.(ABSTRACT TRUNCATED AT 250 WORDS)
The radiologic prediction of Alzheimer disease: the atrophic hippocampal formation. (1993)

Our findings strongly suggest that among persons with mild memory impairments, dilatation of the perihippocampal fissures is a useful radiologic marker for identifying the early features of Alzheimer disease.