gebhart/patrepeval huggingface dataset:
Interface studies of tungsten nitride and titanium nitride composite metal gate electrodes with thin dielectric layers (1998)

Interface formation between reactively sputtered tungsten nitride (WNx) or titanium nitride (TiNx) metallic films and thermally grown silicon dioxide (SiO2) layers is studied by interrupted growth with on-line Auger electron spectroscopy. For both composite metals, growth proceeds directly without a metal precursor layer. The chemical stability of these WNx/SiO2 and TiNx/SiO2 interfaces is investigated by rapid thermal annealing up to 850 °C. The WNx/SiO2 interface is stable up to 650 °C while TiNx/SiO2 is stable below 850 °C. Metal–oxide–semiconductor capacitors have been fabricated with WNx and TiNx gates and 7.5 nm thick thermal oxide gate dielectrics with interface trap densities, Dit&amp;lt;2×1011 cm−2 eV−1. Capacitance–voltage and current–voltage measurements indicate the Fermi level for TiNx lies near midgap in Si, while for WNx it lies closer to the valence band.
Recombinant fowlpox virus vaccines for poultry (1993)

The intensive poultry industries rely heavily upon the use of vaccines for disease control. Viral vector based vaccines offer new avenues for the development of vaccines for effective disease control in poultry. Techniques developed for the construction of recombinant vaccinia viruses have been readily adapted to the construction of recombinant viruses based on fowlpox virus (rFPV). The ability to insert several genes into the large genome of fowlpox may enable the development of multivalent vaccines and vaccines incorporating immune response modifiers such as lymphokines. Newcastle disease, avian influenza, infectious bursal disease and Marek's disease antigens expressed by rFPV have been shown to be effective vaccines in poultry. None appear, however, to provide a substantial improvement in vaccine efficacy. Recombinant FPV will be a valuable adjunct to conventional vaccines currently in widespread use. Whether rFPV or other vector based vaccines can circumvent the problems of vaccination in the presence of high maternally derived antibodies is yet to be resolved. The observation that avipoxvirus recombinants may be suitable for the vaccination of non-avian species provides an added dimension to vaccines based on FPV or other avipoxviruses. Recombinant FPV will find a useful role in poultry disease control when used in conjunction with conventional vaccines.
Optical properties of theF+center in crystallineAl2O3 (1978)

Ultraviolet optical absorption, emission, and excitation spectra are presented for 14-MeV neutron-irradiated high-purity crystalline ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$. Low-temperature polarized excitation spectra for the 3.8-eV luminescence correlated well with polarized absorption at 4.8 eV (both polarizations) and 5.4 eV ($\stackrel{\ensuremath{\rightarrow}}{\mathrm{E}}\ensuremath{\perp}\stackrel{\ensuremath{\rightarrow}}{\mathrm{c}}$). These optical properties compare favorably with those predicted using wave functions from an earlier pointion calculation for the ${\mathrm{F}}^{+}$ center by La, Bartram, and Cox. The 4.8- and 5.4-eV absorption bands are assigned to the $1A\ensuremath{\rightarrow}1B$ and $1A\ensuremath{\rightarrow}2A$ transitions, respectively, of the ${F}^{+}$ center and the 3.8-eV luminescence is assigned to the $1B\ensuremath{\rightarrow}1A$ transition. The $1A\ensuremath{\rightarrow}2B$ transition could not be conclusively identified, but preliminary evidence suggests it occurs near 6.3 eV. Similar absorption and emission bands are observed following energetic-proton and ${\mathrm{Al}}^{+}$ bombardment. Other uv optical properties are presented, including the quantum efficiency, lifetime, and temperature dependence of the emission.
Treatment of basilar invagination associated with Chiari I malformations in the pediatric population: cervical reduction and posterior occipitocervical fusion (2004)

Object. The reduction of basilar invagination associated with Chiari I malformations in pediatric patients is often possible. Eleven children ranging in age from 1.5 to 17 years underwent a novel treatment method involving decompression, manual reduction, and posterior instrumentation-augmented fusion. Outcomes were evaluated retrospectively. Methods. After decompression of the lesion, manual craniocervical distraction and extension were performed, followed by posterior occipitocervical fusion involving rigid internal fixation. All patients were symptomatic at presentation. Intraoperative monitoring included somatosensory evoked potentials, fluoroscopy, and direct intradural demonstration of the craniocervical junction. No new neurological deficits occurred immediately after surgery. Perioperatively, symptoms in seven patients improved significantly and in four they remained unchanged. Three patients required subsequent transoral resections. During long-term follow up (mean 39.4 months, range 3–92 months) symptoms improved markedly in nine, remained unchanged in one, and progressively worsened in one patient. Conclusions. In selected cases, manual cervical distraction and extension, posterior fixation, and fusion appear to provide a safe, effective standalone treatment for basilar invagination associated with Chiari malformation in children.
Carbon Nanotubes Decorated with Pt Nanocubes by a Noncovalent Functionalization Method and Their Role in Oxygen Reduction (2008)

Combined with polymer wrapping and layer-by-layer techniques, a noncovalent functionalization method is developed todisperse Pt nanocubes (NCs) onto carbon nanotubes (CNTs). By adjusting therelative ratio of Pt NCs to CNTs, nanotubes with different Pt NC loadings are produced. The composites exhibit excellent electrocatalytic activity towards oxygen reduction.
Release of caspase-9 from mitochondria during neuronal apoptosis and cerebral ischemia (1999)

Caspase-9 is critical for cytochrome c (cyto-c)-dependent apoptosis and normal brain development. We determined that this apical protease in the cyto-c pathway for apoptosis resides inside mitochondria in several types of cells, including cardiomyocytes and many neurons. Caspase-9 is released from isolated mitochondria on treatment with Ca2+ or Bax, stimuli implicated in ischemic neuronal cell death that are known to induce cyto-c release from mitochondria. In neuronal cell culture models, apoptosis-inducing agents trigger translocation of caspase-9 from mitochondria to the nucleus, which is inhibitable by Bcl-2. Similarly, in an animal model of transient global cerebral ischemia, caspase-9 release from mitochondria and accumulation in nuclei was observed in hippocampal and other vulnerable neurons exhibiting early postischemic changes preceding apoptosis. Loss of mitochondrial barrier function during neuronal damage from ischemia or other insults therefore may play an important role in making certain caspases available to participate in apoptosis.
[Regulation of foreign plasmid DNA on immune gene after oral administration in mice]. (2005)

Foreign plasmid DNA can modulate the expression of immune genes via the gastrointestinal tract, and further analysis of related genes and process may help to understand the molecular mechanisms of foreign plasmid DNA in the gastrointestinal tract.
Biomimetic Approaches for Fabricating High-Density Nanopatterned Arrays (2007)

A variety of alternative approaches to lithography have been investigated to address the many challenges currently associated with scaling of feature sizes. One of the more cost-effective techniques has been to use the intrinsic self-assemblying properties of AB diblock copolymers to make polymer thin films as nanometer etch masks. A more etch-resistant film can be fabricated through enrichment of domains within the block copolymer thin films with metals such as silicon. In contrast to previous methods for mineralizing polymer thin films, we demonstrate here a biomimetic approach for synthesizing two-dimensional silica nanopatterns at neutral pH and mild temperatures within polystyrene-b-poly-4-vinylpyridine thin films. We further show that one can employ these benign synthetic conditions to fabricate sub-20 nm features of phase change materials (PCM) while keeping the PCM film in its amorphous state in order to study the effect that scaling these materials has on their crystallization temperatures.
Direct determination of the protonation states of aspartic acid-102 and histidine-57 in the tetrahedral intermediate of the serine proteases: neutron structure of trypsin (1981)

A neutron structure analysis at 2.2-A resolution has been performed on bovine trypsin covalently inhibited by a transition-state analogue, the monoisopropylphosphoryl (MIP) group. The unique ability of neutron diffraction to locate hydrogen atoms experimentally has allowed the determination of the protonation states of the catalytic site residues (Asp-102 and His-57). Since the bound MIP group mimics the tetrahedral intermediate structure, these correspond to the protonation states at the most crucial step of the hydrolysis. This has resolved a much debated mechanistic issue by showing conclusively that the catalytic base in the transition state of the reaction is His-57, not Asp-102. This finding has important implications for the understanding of the hydrolysis mechanism of the serine proteases. A detailed examination of the stereochemical interaction among the catalytic groups was also conducted to identify their individual roles in the mechanism. Besides functioning as the catalytic group, it was found that His-57 could effectively "steer" the attacking water toward the acyl group during deacylation. Other aspects of protein structure which are observable only by neutron diffraction analysis are also discussed. These include orientation of well-ordered amide side chains, which is made possible by the large scattering difference between nitrogen and oxygen atoms, location and orientation of water molecules, and hydrogen exchange properties of the protein.
Overexpression of C-terminal Src Kinase Homologous Kinase Suppresses Activation of Lyn Tyrosine Kinase Required for VLA5-mediated Dami Cell Spreading (1998)

The Csk homologous kinase (Chk), which is co-expressed with C-terminal Src kinase (Csk) in hematopoietic cells, negatively regulates Src family kinases in vitro with selectivity toward Lyn but not c-Src in platelets. To explore the role of Src family kinases in hematopoietic cell adhesion, we overexpressed Chk in the megakaryocytic cell line Dami and established clones exhibiting a 10-fold increase in the amount of Chk. Overexpression of Chk was found to suppress VLA5 integrin-mediated cell spreading, but not cell attachment, throughout fibronectin (FN) stimulation. Deletion and point mutagenesis analyses of Chk showed that this suppression was dependent upon both the SH3 domain, which is responsible for membrane anchoring, and kinase activity. FN-induced cell spreading accompanied a sustained increase in Lyn activity with coincidental kinetics and the activation of Lyn was also suppressed by overexpression of Chk but not a Chk mutant lacking the SH3 domain. Expression of a truncated Lyn mutant lacking the kinase domain inhibited both cell spreading and Lyn activation upon stimulation with FN. These results suggest that sustained activation of Lyn, which is regulated by membrane-anchored Chk, plays a crucial role in VLA5-mediated cell spreading but not cell attachment to a FN substrate.
Relationships and tasks in scientific research collaborations (1986)

Most computer-based aids for researchers and other workers have had individuals rather than groups or teams as their beneficiaries. This is unfortunate, since much work in business, government, and academia is performed by groups of people. In this paper we examine research collaborations as a particularly informative example of group work and propose a model of research collaboration that should provide guidance to those developing technology to support collaborative work. The model is based on 50 semi-structured interviews with researchers in psychology, management science, and computer science. It focuses on the problems in forming and maintaining personal relationships and completing tasks that researchers must solve to have a successful collaboration. These problems occur when collaborators are initiating projects, executing them, and documenting results.
A Fast Index for Semistructured Data (2001)

Queries navigate semistructured data via path expressions, and can be accelerated using an index. Our solution encodes paths as strings, and inserts those strings into a special index that is highly optimized for long and complex keys. We describe the Index Fabric, an indexing structure that provides the efficiency and flexibility we need. We discuss how &amp;quot;raw paths&amp;quot; are used to optimize ad hoc queries over semistructured data, and how &amp;quot;refined paths&amp;quot; optimize specific access paths. Although we can use knowledge about the queries and structure of the data to create refined paths, no such knowledge is needed for raw paths. A performance study shows that our techniques, when implemented on top of a commercial relational database system, outperform the more traditional approach of using the commercial system&amp;apos;s indexing mechanisms to query the XML.
Halogen Bonding and π···π Stacking Control Reactivity in the Solid State (2004)

The halogen bonding and the π···π stacking interactions induce the noncovalent self-assembly of modules into photoreactive supramolecular architecture. The π···π interaction pre-organizes the template, and the halogen bonding aligns the olefins to conform to the topochemical principle for photoreaction. The UV irradiation of the crystal resulted in a cyclization product with quantitative yield and stereospecificity.
Matrix metalloproteinase 2 in tumor cell-induced platelet aggregation: regulation by nitric oxide. (2001)

A correlation exists between the ability of tumor cells to aggregate platelets and their tendency to metastasize. Tumor cell-induced platelet aggregation (TCIPA) facilitates the embolization of the vasculature with tumor cells and the formation of metastatic foci. It is well documented that matrix metalloproteinases (MMPs) play an integral part in tumor spread and the metastatic cascade. Therefore, we have examined the role of MMPs during TCIPA and its regulation by nitric oxide (NO) in vitro. Human HT-1080 fibrosarcoma and A549 lung epithelial cancer cells induced TCIPA in a concentration-dependent manner that was monitored by aggregometry. This aggregation resulted in the release of MMIP-2 from platelets and cancer cells, as measured by zymography. HT-1080 cells released significantly more MMP-2 than A549 cells and were more efficacious in inducing TCIPA. Inhibition of MMP-2 with phenanthroline (1-1000 microM), a synthetic inhibitor of MMPs, and by neutralizing anti-MMIP-2 antibody (10 microg/ml) reduced TCIPA induced by HT-1080 cells. TCIPA was abolished by simultaneous inhibition of platelet function with acetylsalicylic acid (100 microM; thromboxane pathway inhibitor), apyrase (250 microg/ml; ADP pathway inhibitor), and phenanthroline. NO donors such as S-nitroso-n-acetylpenicillamine and S-nitrosoglutathione (both at 0.01-100 microM) inhibited TCIPA and MMP-2 release from platelets and tumor cells. The inhibitory actions of S-nitroso-n-acetylpenicillamine and S-nitrosoglutathione were reversed by 1H-[1,2,4]oxadiazole[4,3]quinoxalin-1-one (0.01-30 microM), a selective inhibitor of the soluble guanylyl cyclase. We conclude that (a) human fibrosarcoma cells aggregate platelets via mechanism(s) that are mediated, in part, by MMP-2; (b) NO inhibits TCIPA, in part, by attenuating the release of MMP-2; and (c) these effects of NO are cGMP-dependent.
The Natural History of Headache: Predictors of Onset and Recovery (2006)

The objective of this study was to determine predictors of onset of new headache episodes and recovery from headache over one year. A population-based cohort study was conducted, comprising a baseline postal survey to a random sample of adults aged>or=18 years, with follow-up survey after 1 year. Risk factor data at baseline were compared with headache status at follow-up in two groups: (i) those free of recent headache at baseline and (ii) those with a recent headache at baseline. In respondents free of recent headache at baseline, previous headache [risk ratio (RR) 4.15], the presence of other pain at baseline (RR 1.43), severe sleep problems (RR 1.67) and drinking caffeine (RR 1.99) increased the risk of a new headache episode during the follow-up year. In respondents with recent headache at baseline, less severe headaches at baseline predicted recovery during the follow-up year, as did the absence of anxiety [recovery ratio (ReR) 2.84] and of sleep problems (ReR 2.77). Risks for increased headache-related disability reflected those for onset of a new episode and these risks increased in strength for large increases in disability. Sleep problems and caffeine consumption increase the risk of developing headache and thus provide targets for prevention. Low levels of anxiety, sleep problems and the absence of other pain improve the likelihood of recovering and remaining free from headache.
Expression and Regulation of Major Histocompatibility Complex on Neural Stem Cells and Their Lineages (2008)

The expression of major histocompatibility complex (MHC) antigens on neural stem cells (NSCs) and their lineages is tightly related to the fate of these cells as grafts in allogenic transplantation. In this study, we observed that NSCs derived from embryonic rat forebrain expressed MHC class I and class II molecules at a low level, whereas the cells differentiated from NSCs, including neurons, astrocytes, and oligodendrocytes, lost their MHC expression. However, a proinflammatory factor, interferon-γ (IFN-γ), could induce and up-regulate the expression of MHC in both NSCs and their differentiated lineages in vitro. These results suggest that predifferentiating NSCs into lineage-limited cells prior to transplantation combined with controlling the local production of proinflammatory cytokines moderately may potentially benefit the survival of transplants.
Preanalytical variability: the dark side of the moon in laboratory testing (2006)

Remarkable advances in instrument technology, automation and computer science have greatly simplified many aspects of previously tedious tasks in laboratory diagnostics, creating a greater volume of routine work, and significantly improving the quality of results of laboratory testing. Following the development and successful implementation of high-quality analytical standards, analytical errors are no longer the main factor influencing the reliability and clinical utilization of laboratory diagnostics. Therefore, additional sources of variation in the entire laboratory testing process should become the focus for further and necessary quality improvements. Errors occurring within the extra-analytical phases are still the prevailing source of concern. Accordingly, lack of standardized procedures for sample collection, including patient preparation, specimen acquisition, handling and storage, account for up to 93% of the errors currently encountered within the entire diagnostic process. The profound awareness that complete elimination of laboratory testing errors is unrealistic, especially those relating to extra-analytical phases that are harder to control, highlights the importance of good laboratory practice and compliance with the new accreditation standards, which encompass the adoption of suitable strategies for error prevention, tracking and reduction, including process redesign, the use of extra-analytical specifications and improved communication among caregivers.
Current Concepts Review - The Science of Reconstruction of the Anterior Cruciate Ligament* (1997)

FRANK, CYRIL B. M.D., F.R.C.S.(C)†, CALGARY, ALBERTA, CANADA; JACKSON, DOUGLAS W. M.D.‡, LONG BEACH, CALIFORNIA Author Information
Hydroxyl Stereochemistry and Amine Number within Poly(glycoamidoamine)s Affect Intracellular DNA Delivery (2005)

Nucleic acid drugs have great potential to treat many devastating aliments, but their application has been hindered by the lack of efficacious and nontoxic delivery vehicles. Here, a new library of poly(glycoamidoamine)s (D1-D4, G1-G4, and M1-M4) has been synthesized by polycondensation of esterified d-glucaric acid (D), dimethyl-meso-galactarate (G), and d-mannaro-1,4:6,3-dilactone (M) with diethylenetriamine (1), triethylenetetramine (2), tetraethylenepentamine (3), and pentaethylenehexamine (4). The stereochemistry of the carbohydrate hydroxyl groups and the number of amine units have been systematically changed in an effort to examine how the polymer chemistry affects the plasmid DNA (pDNA) binding affinity, the compaction of pDNA into nanoparticles (polyplexes), the material cytotoxicity, and the efficacy of nucleic acid delivery. The polymers with four secondary amines (D4, G4, and M4) between the carbohydrates were found to have the highest pDNA binding affinity and the galactarate polymers generally yielded the smallest polyplexes. Delivery studies with pDNA containing the firefly luciferase or beta-galactosidase reporter genes in BHK-21, HeLa, and HepG2 cells demonstrated that all of the poly(glycoamidoamine)s deliver pDNA without cytotoxicity. Polymers D4, G4, and M4 displayed the highest delivery efficiency, where G4 was found to be a particularly effective delivery vehicle. Heparin competition assays indicated that this may be a result of the higher pDNA binding affinity displayed by G4 as compared to D4 and M4. Polyplexes formed by polymers with weaker pDNA affinities may dissociate at the cell surface due to interactions with negatively charged glycosaminoglycans, which would cause a decrease in the number of polyplexes that are endocytosed.
Altered glycosylation of the MUC-1 protein core contributes to the colon carcinoma-associated increase of mucin-bound sialyl-Lewis(x) expression. (1993)

The mucin carbohydrate epitope sialyl-Le(x), detected with the monoclonal antibody AM-3, is strongly overexpressed in > 90% of human colon carcinomas. We show here that in colon carcinoma one of the mucin cores bearing the sialyl-Le(x) group is MUC-1, whereas sialyl-Le(x) present in normal colon is not detectable on MUC-1. The amounts of MUC-1 core detectable with the monoclonal antibody BC3 in extracts of tumor tissue are 60-180% of those in normal tissue. Two other carbohydrate epitopes located on MUC-1 in mucins from normal and tumor tissue have also been characterized. In contrast to sialyl-Le(x), their expression on MUC-1 is variable and does not correlate with the malignant transformation of colonic mucosa. The transfer of the sialyl-Le(x) group onto the MUC-1 core contributes to the colon carcinoma-associated overexpression of the sialyl-Le(x) epitope.