gebhart/patrepeval huggingface dataset:
Sampling and reconstruction effects due to motion in diffusion-weighted interleaved echo planar imaging (2000)

Subject motion during diffusion-weighted interleaved echo-planar imaging causes k-space offsets which lead to irregular sampling in the phase-encode direction. For each image, the k-space shifts are monitored using 2D navigator echoes, and are shown to lead to a frequent violation of the Nyquist condition when an ungated sequence is used on seven subjects. Combining data from four repeat acquisitions allows the Nyquist condition to be satisfied in all but 1% of images. Reconstruction of the irregularly-sampled data can be performed using a matrix inversion technique. The repeated acquisitions make the inversion more stable and additionally improve the signal-to-noise ratio. The resultant isotropic diffusion-weighted images and average apparent diffusion coefficient (ADC) maps show high resolution and enable clear localization of a stroke lesion. Residual ADC artifacts with a slow spatial variation are observed and assumed to originate from non-rigid pulsatile brain motion. Magn Reson Med 44:101-109, 2000.
<i>Pseudomonas aeruginosa</i> uses a cyclic‐di‐GMP‐regulated adhesin to reinforce the biofilm extracellular matrix (2010)

Pseudomonas aeruginosa, the principal pathogen of cystic fibrosis patients, forms antibiotic-resistant biofilms promoting chronic colonization of the airways. The extracellular (EPS) matrix is a crucial component of biofilms that provides the community multiple benefits. Recent work suggests that the secondary messenger, cyclic-di-GMP, promotes biofilm formation. An analysis of factors specifically expressed in P. aeruginosa under conditions of elevated c-di-GMP, revealed functions involved in the production and maintenance of the biofilm extracellular matrix. We have characterized one of these components, encoded by the PA4625 gene, as a putative adhesin and designated it cdrA. CdrA shares structural similarities to extracellular adhesins that belong to two-partner secretion systems. The cdrA gene is in a two gene operon that also encodes a putative outer membrane transporter, CdrB. The cdrA gene encodes a 220 KDa protein that is predicted to be rod-shaped protein harbouring a beta-helix structural motif. Western analysis indicates that the CdrA is produced as a 220 kDa proprotein and processed to 150 kDa before secretion into the extracellular medium. We demonstrated that cdrAB expression is minimal in liquid culture, but is elevated in biofilm cultures. CdrAB expression was found to promote biofilm formation and auto-aggregation in liquid culture. Aggregation mediated by CdrA is dependent on the Psl polysaccharide and can be disrupted by adding mannose, a key structural component of Psl. Immunoprecipitation of Psl present in culture supernatants resulted in co-immunoprecipitation of CdrA, providing additional evidence that CdrA directly binds to Psl. A mutation in cdrA caused a decrease in biofilm biomass and resulted in the formation of biofilms exhibiting decreased structural integrity. Psl-specific lectin staining suggests that CdrA either cross-links Psl polysaccharide polymers and/or tethers Psl to the cells, resulting in increased biofilm structural stability. Thus, this study identifies a key protein structural component of the P. aeruginosa EPS matrix.
Localization of three human polypeptide GalNAc-transferases in HeLa cells suggests initiation of O-linked glycosylation throughout the Golgi apparatus (1998)

O-glycosylation of proteins is initiated by a family of UDP-N-acetylgalactosamine:polypeptide N-acetylgalactos-aminyltransferases (GalNAc-T). In this study, we have localized endogenous and epitope-tagged human GalNAc-T1, -T2 and -T3 to the Golgi apparatus in HeLa cells by subcellular fractionation, immunofluorescence and immunoelectron microscopy. We show that all three GalNAc-transferases are concentrated about tenfold in Golgi stacks over Golgi associated tubular-vesicular membrane structures. Surprisingly, we find that GalNAc-T1, -T2 and -T3 are present throughout the Golgi stack suggesting that initiation of O-glycosylation may not be restricted to the cis Golgi, but occur at multiple sites within the Golgi apparatus. GalNAc-T1 distributes evenly across the Golgi stack whereas GalNAc-T2 and -T3 reside preferentially on the trans side and in the medial part of the Golgi stack, respectively. Moreover, we have investigated the possibility of O-glycan initiation in pre-Golgi compartments such as the ER. We could not detect endogenous polypeptide GalNAc-transferase activity in the ER of HeLa cells, neither by subcellular fractionation nor by situ glycosylation of an ER-retained form of CD8 (CD8/E19). However, upon relocation of chimeric GalNAc-T1 or -T2 to the ER, CD8/E19 is glycosylated with different efficiencies indicating that all components required for initiation of O-glycosylation are present in the ER except for polypeptide GalNAc-transferases.
A Novel Europium(III)-Based MRI Contrast Agent (2001)

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Novel Europium(III)-Based MRI Contrast AgentShanrong Zhang, Patrick Winter, Kuangcong Wu, and A. Dean SherryView Author Information Department of Chemistry, University of Texas at Dallas P.O. Box 830688, Richardson, Texas 75083 Department of Radiology Rogers Magnetic Resonance Center 5801 Forest Park Road, Dallas, Texas 75235 Cite this: J. Am. Chem. Soc. 2001, 123, 7, 1517–1518Publication Date (Web):January 26, 2001Publication History Received22 November 2000Published online26 January 2001Published inissue 1 February 2001https://doi.org/10.1021/ja005820qCopyright © 2001 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views2255Altmetric-Citations216LEARN 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 InReddit Read OnlinePDF (41 KB) Get e-AlertsSUBJECTS:Imaging,Power,Resonance structures,Saturation,Water Get e-Alerts
Make plasticizer olefins via n-butene dimerization (1986)

The trends in end uses for the PVC plasticizers now favor C/sub 9/-C/sub 13/ oxo alcohols, which yield less volatile products exhibiting the greater heat resistance needed in an increasing percentage of all applications. A great many alternative plasticizer products have reached prominence because the more common plasticizers cannot meet these more stringent requirements. The common denominator of these new compounds is highly linear C/sub 9/-C/sub 13/ oxo alcohols, some of which can be made from octol olefins with very favorable economics relative to other technologies. The Octol process dimerizes N-butene to ocetenes and trimerizes to dodecenes for plasticizer olefins. In addition to process technical and economic data, some comparisons of properties among alternative products and their production economics are presented.
Staging of suspected breast cancer: effect of MR imaging and MR-guided biopsy. (1995)

MR imaging allows detection of mammographically and clinically occult foci of carcinoma in patients with suspected breast cancer.
Tissue engineering of a hybrid bypass graft for coronary and lower limb bypass surgery (2008)

Tissue-engineered blood vessels have largely relied on inelastic scaffolds or biological solutions with uncertain long-term in vivo durability. In this report we present for the first time a hybrid tissue-engineered bypass graft consisting of an elastic scaffold of compliant poly(carbonate-urea)urethane (CPU), incorporated with human smooth muscle cells (SMCs) and endothelial cells (ECs) from the same human source. Human vascular SMCs and ECs were extracted from umbilical cord vessels. The effect of shear stress preconditioning on cell retention on the hybrid bypass graft was investigated under pulsatile arterial flow conditions. Retention of ECs seeded onto CPU precoated with SMCs was significantly improved by a period of shear stress preconditioning, especially when the stress incrementally increased. This is probably because the mechanical stimuli orient cells and increase the release of matrix proteins and attachment factors. The stage is now set for developing a hybrid graft for in vivo studies.
Ultra-thin epitaxial films of graphite and hexagonal boron nitride on solid surfaces (1997)

In this article, we have reviewed the recent progress of the experimental studies on ultra-thin films of graphite and hexagonal boron nitride (h-BN) by using angle-resolved electron spectroscopy together with other techniques. The fundamental properties of these high-quality films are discussed on the basis of the data on dispersion relations of valence electrons, phonon dispersion etc. The interfacial orbital mixing of the -state of the monolayer graphite (MG) with the d states of the reactive substrates is the origin for the phonon softening, expansion of the nearest-neighbour C - C distance, modification of the -band, low work function, and two-dimensional plasmons with high electron density, etc. In the cases of weak mixing at the interface between the MG and relatively inert substrates, the observed properties of the MG are very close to the bulk ones. In contrast to the case for MG, the interfacial interaction between the h-BN monolayer and the substrate is weak.
Factores tecnológicos y estructurales explicativos de la internacionalización de las empresas innovadoras (1997)

Investigacion que plantea la busqueda de los principales determinantes tecnologicos y estructurales que influyen en la decision de internacionalizacion de las empresas a traves de tres vias: la exportacion, la inversion directa y la concesion de licencias a empresas extranjeras.

ABSTRACT: The research on the internationalization of firms ought to be closely related to the small and medium firms´ foreign activities, given their growing importance in these processes. At the same time, technological aspects play a crucial role in the internationalization decisions.
Activation of the B-cell Surface Receptor CD40 Induces A20, a Novel Zinc Finger Protein That Inhibits Apoptosis (1995)

CD40 activation is critical for B-cell function, leading to activation and expression of cell surface markers, proliferation, immunoglobulin class switching and inhibition of programmed cell death (PCD). Germinal center B-cells, for example, can be prevented from undergoing PCD by CD40 activation. The mechanism by which PCD is inhibited has been an enigma. A potential role for A20, a novel zinc finger protein, in inhibiting B-cell apoptosis was suggested by our previous finding that it is induced by the Epstein-Barr virus LMP-1 gene product, a potent cell death inhibitor. We now show that CD40 activation induces A20 and that expression of A20 renders B-cell lines resistant to PCD. Additionally, we show that CD40 activation of A20 expression is mediated by inducible binding of NF-κB complexes to the A20 promoter and provide evidence for a critical role for Thr234 (in the CD40 cytoplasmic domain) in activating NF-κB. CD40 activation is critical for B-cell function, leading to activation and expression of cell surface markers, proliferation, immunoglobulin class switching and inhibition of programmed cell death (PCD). Germinal center B-cells, for example, can be prevented from undergoing PCD by CD40 activation. The mechanism by which PCD is inhibited has been an enigma. A potential role for A20, a novel zinc finger protein, in inhibiting B-cell apoptosis was suggested by our previous finding that it is induced by the Epstein-Barr virus LMP-1 gene product, a potent cell death inhibitor. We now show that CD40 activation induces A20 and that expression of A20 renders B-cell lines resistant to PCD. Additionally, we show that CD40 activation of A20 expression is mediated by inducible binding of NF-κB complexes to the A20 promoter and provide evidence for a critical role for Thr234 (in the CD40 cytoplasmic domain) in activating NF-κB.
FAS/FAS Ligand Interaction at the Placental Interface is not Required for the Success of Allogeneic Pregnancy in Anti-Paternal MHC Preimmunized Mice (2001)

FAS/FASL interaction between FAS+ T cells and FASL+ fetal trophoblasts at the fetomaternal interface is not mandatory for successful allopregnancy. The potential roles of other apoptosis-induction mechanisms at the fetomaternal interface, such as TNF/TRAIL, require critical testing before enthusiasm is merited. It maybe necessary to eliminate all such mechanisms to show a deleterious effect on pregnancy. Spontaneous deletion of all pathways seems a priori unlikely to occur, and hence, of dubious relevance to fetal loss.
Reduction of Submissive Behavior Model for antidepressant drug activity testing: study using a video-tracking system (2005)

Submissive animals can be defined in a food competition test as spending significantly less time on the feeder than their dominant partners. Using observer-based scoring in the Reduction of Submissive Behavior Model, submissive behavior in rats and mice has been previously shown to be sensitive and selective to antidepressant treatment. In this paper, we report the use of automated scoring by a multiple-subject video-tracking system to record similar effects of antidepressants on rat submissive behavior. Automated scoring enabled the observation of four pairs of rats during each 5-min experimental session (one set) and immediate switching to the observation of the next four pairs of animals. Studies were conducted to confirm our previous results with imipramine and fluoxetine that were obtained with manual scoring, and to extend those results to studies with other drugs, including the antidepressant maprotiline and the delta-opioid antagonist naltrindole, which is not known to have antidepressant activity. As in previous studies, treatment of the submissive animal for 5 weeks with imipramine (20 mg/kg) or fluoxetine (10 mg/kg) significantly reduced submissive behavior, with a delayed onset of antidepressant effect that was dependent on drug dose. Maprotiline (10 and 20 mg/kg), like imipramine or fluoxetine and in contrast to naltrindole, strongly reduced rat submissive behavior, further demonstrating the selectivity of this test for antidepressant activity.
Critical oxygen levels to avoid corneal edema for daily and extended wear contact lenses. (1984)

The relationship between corneal edema and hydrogel lens oxygen transmissibility was examined for both daily and extended contact lens wear by measuring the corneal swelling response induced by a variety of contact lenses over a 36-hr wearing period. The relationships derived enable average edema levels that occur with daily and extended wear in a population of normal young adults to be predicted to within +/- 1.0%. The critical lens oxygen transmissibilities required to avoid edema, for the group as a whole, for daily and extended contact lens wear were obtained from the derived curves. It was found under daily wear conditions that lenses having an oxygen transmissibility of at least 24.1 +/- 2.7 X 10(-9) (cm X ml O2)/(sec X ml X mmHg), an Equivalent Oxygen Percentage (EOP) of 9.9%, did not induce corneal edema. This level of oxygen transmissibility can be achieved (1) in standard, low water content, poly-HEMA lenses by using an average lens thickness of 33 microns or less, or (2) in a higher water content material, such as Duragel 75, by using an average thickness of 166 microns or less. The critical hydrogel lens oxygen transmissibility needed to limit overnight corneal edema to 4% (the level experienced without a contact lens in place) was found to be 87.0 +/- 3.3 X 10(-9) (cm X ml O2)/(sec X ml X mmHg)--an EOP of 17.9%. This ideal level of oxygen transmissibility cannot, at present, be provided with hydrogel materials.(ABSTRACT TRUNCATED AT 250 WORDS)
Immunohistochemical diagnosis of Neospora caninum in tissue sections (1989)

An avidin-biotin-peroxidase complex immunoperoxidase staining method was developed to detect Neospora caninum in formalin-fixed, paraffin-embedded tissue sections. Specific antiserum to N caninum was made in rabbits and used to probe tissues from dogs naturally and experimentally infected with N caninum. The test detected tachyzoites and bradyzoites of N caninum. A reaction was not observed to Toxoplasma gondii, Hammondia hammondi, Sarcocystis cruzi, S capricanis, S tenella, Besnoitia jellisoni, Caryospora bigenetica, Hepatazoon canis, Atoxoplasma sp, or the organism causing canine dermal coccidiosis. When antiserum made in rabbits to T gondii was used in the test, reaction to N caninum was not observed.
The design and implementation of the 4.3BSD UNIX operating system (1989)

The first authoritative description of Berkeley UNIX, its design and implementation. Book covers the internal structure of the 4.3 BSD systems and the concepts, data structures and algorithms used in implementing the system facilities. Chapter on TCP/IP. Annotation copyright Book News, Inc. Portlan
Influence of passive humidification on respiratory heat loss in tracheotomized patients (2006)

The results indicate that passive airway humidification is effective in tracheotomized patients even after a 10-minute period. However, the positive effect on the energy balance of the tracheal mucosa after prolonged use of the HME remains to be proven.
3D modeling of indoor environments by a mobile robot with a laser scanner and panoramic camera (2005)

We present a method to acquire a realistic, visually convincing 3D model of indoor office environments based on a mobile robot that is equipped with a laser range scanner and a panoramic camera. The data of the 2D laser scans are used to solve the SLAM problem and to extract walls. Textures for walls and floor are built from the images of a calibrated panoramic camera. Multiresolution blending is used to hide seams in the generated textures.
Prevention of Stress‐Induced Erosive Gastritis by Parenteral Administration of Arachidonic Acid (1990)

Stress-induced mucosal ulcerations are associated with a decreased synthesis of mucosal prostaglandin (PG) E2. This phenomenon is poorly understood. To investigate whether it is due to a decreased availability of the necessary substrates to the mucosa, four groups of 10 Holtzman rats were studied: group 1 received normal saline by intraperitoneal (ip) injection; group 2 also received ip normal saline, then were submitted to stress, by the cold restraint method; group 3 received a solution of arachidonic acid (AA) ip; and group 4 also received ip AA, then were submitted to stress. After sacrifice, the number of gastric ulcerations were counted and specimens of nonulcerated mucosa were assayed for PGE2 by high-performance liquid chromatography; the mean numbers of ulcers were 0, 5.8, 0.8, and 3 and the mean levels of PGE2 were 55, 41, 125, and 62 pg/mg of wet tissue for groups 1, 2, 3, and 4, respectively. It is concluded that parenteral administration of AA reduces but does not completely eliminate stress-induced gastric ulcerations and that the stressed animals synthesized half as much PGE2 as the nonstressed ones after ip administration of equal amounts of AA, suggesting that stress reduces the availability of AA to the gastric mucosa, possibly by vascular spasm.
Stromal biology and therapy in pancreatic cancer (2010)

Pancreatic ductal adenocarcinoma (PDA) is an almost uniformly lethal disease. One explanation for the devastating prognosis is the failure of many chemotherapies, including the current standard of care therapy gemcitabine. Although our knowledge of the molecular events underlying multistep carcinogenesis in PDA has steadily increased, translation into more effective therapeutic approaches has been inefficient over the last several decades. Evidence for this innate resistance to systemic therapies was recently provided in an accurate mouse model of PDA by the demonstration that chemotherapies are poorly delivered to PDA tissues because of a deficient vasculature. This vascular deficiency correlated with the presence of a dense stromal matrix that is a prominent histological hallmark of PDA tumours. Therapeutic targeting of stromal cells decreased the stroma from pancreatic tumours, resulting in increased intratumoral perfusion and therapeutic delivery of gemcitabine. Stromal cells contained within the PDA tumour microenvironment therefore represent an additional constituent to neoplastic cells that should be critically evaluated for optimal therapeutic development in preclinical models and early clinical trials.
Influence of polymerization conditions on the copolymerization of styrene with ethylene using Me<sub>2</sub>Si(Me<sub>4</sub>Cp)(<i>N</i>‐<i>tert</i>‐butyl)TiCl<sub>2</sub>/methylaluminoxane Ziegler‐Natta catalysts (1996)

Abstract Styrene was copolymerized with ethylene using Me 2 Si(Me 4 Cp)( N‐tert ‐butyl)TiCl 2 /methylaluminoxane (Me = methyl, Cp = cyclopentadienyl) varying monomer concentration, styrene/ethylene molar ratio and polymerization temperature. Increasing styrene or decreasing ethylene concentration, respectively, in the monomer feed lowered both activity of the catalyst system and molecular weight of the copolymer. Only at low styrene content, a linear correlation of styrene concentration in the monomer feed and styrene incorporation in the copolymer was found. From copolymerizations at various temperatures the activation energy of the insertion step was calculated to be 56 kJ/mol. According to Fineman‐Ross plot, the copolymerization parameters are r E = 23,4 for ethylene and r S = 0,015 for styrene. Investigation of the thermal properties by means of differential scanning calorimetry and dynamic mechanical analysis revealed pronounced decrease of melting temperature and increase of glass transition temperature with increasing styrene content.
Steel-Polypropylene-Steel Laminate – A New Weight Reduction Material (1980)

The dent resistance, flexural stiffness, fatigue strength, and formability are characterized for a steel-polypropylene-steel (S-P-S) laminate for automotive applications. Many of these physical properties are comparable to those of steel. The S-P-S laminate takes advantage of the I-beam principle in bending. The highest stress is in the surface, with the lowest stress at the neutral axis. The material has a high stiffness-to-weight ratio, with the potential to reduce component weight by 50% with no loss in flexural stiffness. Applications where bending stiffness is the major design criterion include: seat backs, load floors, covers, narrow body panels, truck trailer sides, and interior trim. One disadvantage of S-P-S is loss of bolt torque due to creep by the polypropylene core. This loss is a function of the applied stress level, core thickness and temperature.