gebhart/patrepeval huggingface dataset:
Bimetallic Catalysis for Styrene Homopolymerization and Ethylene−Styrene Copolymerization. Exceptional Comonomer Selectivity and Insertion Regiochemistry (2004)

This communication reports the styrene homopolymerization behavior and ethylene-styrene copolymerization behavior of the covalently linked bimetallic constrained geometry catalyst (mu-CH2CH2-3,3'){(eta5-indenyl)[1-Me2Si(tBuN)](TiMe2)}2 (Ti2), which is the first single-site catalyst that effects not only styrene homopolymerization with high activity, but also efficient ethylene-styrene copolymerization over a broad styrene composition range (0-76% at 20 degrees C, 1.0 atm ethylene pressure). In styrene homopolymerization, a 50x increase in polymerization activity is achieved with Ti2 vs the mononuclear analogue, Ti1, using an identical trityl borate cocatalyst and polymerization conditions. In ethylene + styrene copolymerization, Ti2 enchains approximately 20% more styrene than Ti1 under identical reaction conditions. 13C NMR spectroscopy indicates that greater than two consecutive styrene units are enchained in the copolymer backbone produced by Ti2 + Ph3C+B(C6F5)4-. End group analysis of the styrene homopolymer produced by Ti2 + Ph3C+B(C6F5)4- suggests that 1,2-regiochemistry is installed in approximately 50% of the initiation steps. This unusual microstructure is believed to be related to the bimetallic catalyst structure.
Determination of [3H]- and [14C]hematoporphyrin derivative distribution in malignant and normal tissue. (1979)

The synthesis and tissue-localizing ability of [14C]- and [3H]hematoporphyrin derivative (HPD) in mice have been described. Tissue levels and distributions were the same for both radioactive compounds, indicating that in vivo tritium exchange did not occur with [3H]HPD. The amount of [14C]HPD or [3H]HPD which localized in the transplanted tumor tissue of mice at various times following i.p. injection (10 mg/kg) was higher than in skin or muscle tissue but was less than in liver, kidney, or spleen tissue. These results tend to disprove the generalization that HPD accumulates in malignant tissue to a higher degree than in all normal tissue. It is also reported that gross visualization of porphyrin fluorescence cannot be correlated with actual tissue concentrations of the dye.
The use of eye movements in human-computer interaction techniques (1991)

In seeking hitherto-unused methods by which users and computers can comrnumcate, we investigate the usefulness of eye movements as a fast and convenient auxiliary user-to-computer communication mode. The barrier to exploiting this medium has not been eye-tracking technology but the study of interaction techniques that incorporate eye movements mto the usercomputer dialogue in a natural and unobtrusive way This paper discusses some of the human factors and technical considerations that arise in trying to use eye movements as an input medium, describes our approach and the first eye movement-based interaction techniques that we have devised and implemented in our laboratory, and reports our experiences and observa tions on them.
Multi-layer SU-8 lift-off technology for microfluidic devices (2005)

This paper reports on a novel multilayer SU-8 lift-off technology which allows for low cost rapid prototyping of microfluidic devices. The process presented is based on a multi-layer structure of SU-8 which can be released from the substrate after processing and enables the creation of through holes. The lift-off is accomplished during the development by making use of the volume shrinkage of the SU-8 during postbaking and by modification of the adhesion to the substrate. To demonstrate the technology, prototypes of a multichannel microdispenser according to the Dispensing Well Plate (DWP™) principle (Koltay et al 2004 Sensors Actuators A 116 472, 483) were fabricated. The samples contain 24 parallel dispensing units with 100 µm through holes and a dosage volume of 60 nl. For the first time all functional structures such as reservoirs, channels and through holes (nozzles) of the DWP™ were realized exclusively in the photodefinable epoxy SU-8. To assess the quality of the SU-8 process the geometry of the presented prototypes is characterized by profiler measurements and scanning electron microscopy. Furthermore, the dispensing performance is studied experimentally by gravimetrical measurements. A reproducibility of the dosage volume of 1% and a homogeneity within individual droplet arrays of 3.6% were achieved.
Use of genetic recombination as a reporter of gene expression. (1994)

An understanding of the patterns of gene expression in response to specific environmental signals can yield insight into a variety of complex biological systems such as microbial-host interactions, developmental cycles, cellular differentiation, ontogeny, etc. To extend the utility of the reporter gene fusion approach to such studies, we have constructed a gene expression reporter cassette that permits the generation of transcriptional fusions to tnpR encoding resolvase, a site-specific recombinase of the transposable element gamma delta. Induction of the transcriptional fusions results in production of resolvase, which in turn, catalyzes excision of a linked tetracycline-resistance reporter gene flanked by direct repeats of res, the DNA sequences at which resolvase functions. The loss of tetracycline resistance in descendant bacteria serves as a permanent and heritable marker of prior gene expression. This gene fusion approach will allow us to assay the induction of gene expression in as few as one cell. Additionally, gene expression can be assayed at a later time and/or different place from the inducing environment facilitating the study of gene expression in complex environments such as animal tissues.
Glass transitions of polymers with compressed fluid diluents: type II and III behavior (1994)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGlass transitions of polymers with compressed fluid diluents: type II and III behaviorP. D. Condo, D. R. Paul, and K. P. JohnstonCite this: Macromolecules 1994, 27, 2, 365–371Publication Date (Print):January 1, 1994Publication History Published online1 May 2002Published inissue 1 January 1994https://pubs.acs.org/doi/10.1021/ma00080a008https://doi.org/10.1021/ma00080a008research-articleACS PublicationsRequest reuse permissionsArticle Views499Altmetric-Citations143LEARN 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
A Simple Route to Highly Oriented and Ordered Nanoporous Block Copolymer Templates (2008)

Controlling the orientation and lateral ordering of the block copolymer microdomains is essential to their use as templates and scaffolds for the fabrication of nanostructured materials. In addition, a process must be robust, simple to implement, and rapid, and should not introduce disruptive processing steps that would impede their use. Here, we describe thin films of poly(styrene-b-4-vinylpyridine) (PS-b-P4VP) diblock copolymers, spin-coated from mixed solvents that show highly oriented, cylindrical microdomains with a high degree of order on a wide range of substrates, including silicon oxide, polystyrene, germanium, polyimide, and poly(butylene terephthalate). In addition, the preferential solvation of the P4VP block with an alcohol caused a surface reconstruction that resulted in the formation of a nanoporous film upon drying. The evaporation of gold onto the reconstructed films produced thermally stable and reactive ion etching resistant films.
Identification of latent membrane protein 2A (LMP2A) domains essential for the LMP2A dominant-negative effect on B-lymphocyte surface immunoglobulin signal transduction (1996)

Epstein-Barr virus (EBV) recombinants which carry three different deletion mutations in the LMP2A cytoplasmic amino-terminal domain were constructed. The presence of each mutation, LMP2A delta 21-36, LMP2A delta 21-64, and LMP2A delta 21-85, in EBV-infected transformed lymphoblastoid cell lines was confirmed by PCR analysis and Southern blot hybridization. Confirmation of mutant LMP2A protein expression was by immunofluorescence and immunoblotting with a newly identified rat monoclonal antibody that recognizes each of the LMP2A deletion mutations. Lymphoblastoid cell lines infected with recombinant EBV DNAs containing the mutations were analyzed for loss of LMP2A's dominant-negative effect on surface immunoglobulin signal transduction by monitoring induction of tyrosine phosphorylation, calcium mobilization, and activation of lytic replication following surface immunoglobulin cross-linking. Domains of LMP2A important for induction of tyrosine phosphorylation, calcium mobilization, and activation of lytic replication were identified.
Photochemical Versus Thermal Mechanisms in Matrix-assisted Laser Desorption/Ionization Probed by Back Side Desorption (1996)

The contribution of photochemical and thermal effects in the formation and ejection of biomolecular ions in matrix-assisted laser desorption/ionization; (MALDI) is studied by comparing desorption from one-and-the-same sample in two incident laser geometries—irradiating the sample front, or irradiating the back side through a 2000 Å gold layer. Such a set-up results in the efficient decoupling of photoexcitation from thermal processes. Our results indicate that laser-induced photochemistry, e.g. charge transfer reactions between electronically-excited matrix molecules and the analyte, plays a major role in the MALDI process.
Simple Method for Controlled Association of Colloidal-Particle Mixtures using pH-Dependent Hydrogen Bonding (2009)

We describe a simple method for the controlled mixing of particles that could be used to produce materials with new properties. We demonstrate the procedure with sets of silica particles that have each been coated with one of two different organic thin films. One set of particles is functionalized with carboxylic acid groups and the other with ethylene oxide. Each of these sets of particles is stable in solution. When mixed, heteroaggregation can be induced reversibly and on demand simply by changing the pH. We provide evidence that control over aggregation is achieved by the ability to alter the number of hydrogen bonds between different types of particles and thus the strength of the attraction between different particles. We provide support for this mechanism by measuring the forces between a plate coated in a thin film of carboxylic groups and particles coated in ethylene oxide using colloid probe AFM. At pH 9, where we expect most of the acidic groups to be deprotonated, there is a strong repulsion between the particle and plate. However, at pH 3, the force is attractive, which we assign to the hydrogen bonding between the ether oxygen of the PEO and the hydrogen of the carboxylic acid group. Heteroflocculation occurred in the pH range of 3-4.5. At pH 5 and above, no flocculation was observed. Because the number of hydrogen bonds per surface area and therefore the strength of binding between dissimilar particles can be titrated through control of the pH, we can control the surface forces and avoid rapid coagulation that produces low density and disorganized particle arrangements. The control of interaction forces and therefore the approach of particles should allow the production of composite materials having mixture or product properties.
Improved impedance matrix localization method (EM problems) (1993)

Moment method calculations have the well-known limitations of requiring excessive storage and execution times for even modestly large electromagnetics problems. The impedance matrix localization (IML) method was introduced as a modification to standard moment method calculations to ease these limitations. It utilizes a matrix transformation which effectively changes the basis (testing) functions into ones resembling traveling waves. An improved method that uses an orthogonal transformation to generate standing-wave-like basis functions is presented here. Remarkable improvements are achieved in the numerical stability of the method and in its compatibility with iterative solvers. Furthermore, the correspondence of the large elements in this matrix to geometrical theory of diffraction (GTD) terms is strengthened, as is the possibility of further increasing the speed of iterative solutions by constructing preconditioners based on the pattern of nonzero matrix elements.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Differential expression of elafin in human normal mammary epithelial cells and carcinomas is regulated at the transcriptional level. (1995)

Elafin is an elastase inhibitor with a unique structure, not related to the serpin family, which includes the neutrophil elastase inhibitor. The gene was identified in this laboratory by subtractive hybridization between RNAs from human mammary tumor-derived cells and cDNAs from normal human mammary epithelial cells. Elafin is consistently expressed in normal mammary epithelial cells, but is down-regulated in most breast tumor cell lines. Restriction fragment analysis detected no gross deletions or rearrangement of the gene in any of the tumor cell lines examined. The elafin gene was cloned, and both the cDNA and the promoter region were sequenced. A major positive upstream promoter element was identified by chloramphenicol acetyltransferase assay and deletion analysis, active in normal cell extracts but not in extracts of tumor cells. These results demonstrate that differential expression of elafin in normal mammary epithelial cells and breast tumor cells is regulated at the transcriptional level. Cell synchronization experiments demonstrated that elafin mRNA is down-regulated in S phase in normal cells. These results suggest that elafin may act as an inhibitor of cell cycle progression.
Inactivation of von Hippel-Lindau Gene Induces Constitutive Phosphorylation of MET Protein in Clear Cell Renal Carcinoma (2006)

It is well known that inactivation of von Hippel-Lindau (VHL) gene predisposes for human clear cell renal carcinoma (CCRC). However, details about critical roles of VHL inactivation during tumorigenesis are still unknown. MET protein is a tyrosine kinase receptor for hepatocyte growth factor/scatter factor (HGF/SF), which regulates cell growth, cell morphology, and cell motility. We showed that MET protein overexpressed in CCRC cells was phosphorylated without HGF/SF. This constitutive phosphorylation of MET protein in CCRC cells was inhibited by the rescue of exogenous wild-type VHL gene without a decrease in expression level of MET protein. Interestingly, wild-type VHL gene suppressed the phosphorylation of MET protein only under high cell density conditions. Additionally, MET protein activated by the inactivation of VHL gene modified cell adherence, including N-cadherin and beta-catenin. When activation of MET protein in CCRC cells was inhibited by the MET inhibitor K252a, the growth of CCRC cells in vitro and the tumorigenesis induced by CCRC cells in nude mice were suppressed. From these results, we concluded that inactivation of VHL gene induced constitutive phosphorylation of MET protein and modified intercellular adherence structure to trigger the cell growth released from contact inhibition, finally resulting in tumorigenesis. This is one of the mechanisms of CCRC oncogenesis, and MET protein has potential as a molecular target for novel CCRC therapies.
Detection and concealment of transmission errors in H.261 images (1998)

The detection and concealment approach to transmission errors in H.261 images is proposed. For entropy-coded H.261 images, a transmission error in a codeword will not only affect the underlying codeword, but also may affect subsequent codewords, resulting in a great degradation of the received images. Here a transmission error may be a single-bit error or a burst error containing N successive error bits. The objective of the proposed approach is to recover high-quality H.261 images from the corresponding corrupted H.261 images, without increasing the transmission bit rate. In the proposed approach, using the constraints imposed on compressed image data, all the groups of blocks (GOBs) within an H.261 picture can be correctly located. After a GOB is located, transmission errors within the GOB are detected by two successive procedures: (1) whether the GOB is corrupted or not is determined by checking a set of error-checking conditions under decoding and (2) the precise location (block-based) of the first transmission error (i.e., the first corrupted block) within the GOB is located by a block-based backtracking procedure. For a corrupted block, a set of concealed block candidates, SC, is generated, and a proposed fitness function for error concealment is used to select the "best" concealed block candidate among SC as the concealed block of the corrupted block. Based on the simulation results obtained in this study, the proposed approach can indeed recover high-quality H.261 images from their corresponding corrupted H.261 images.
Green tea in chemoprevention of cancer (1999)

The concept of prevention of cancer using naturally occurring substances that could be included in the diet consumed by the human population is gaining increasing attention. Tea, next to water, is the most popularly consumed beverage in the world and it is grown in about 30 countries. Abundant data, amassed from several laboratories around the world in the last ten years, provided convincing evidence that polyphenolic antioxidants present in tea afford protection against cancer risk in many animal-tumor bioassay systems. The epidemiological studies, though inconclusive, have also suggested that the consumption of tea is associated with a lowered risk of cancer. Much of this work has been done on green tea; less is known about black tea. Green tea contains many polyphenolic antioxidants, and (-)-epigallocatechin-3-gallate (EGCG) is the key polyphenolic antioxidant believed to be responsible for most of the cancer chemopreventive properties of green tea. This review will discuss these effects and the molecular mechanisms associated with the biological response to green-tea polyphenols.
Activin Receptors and Cellular Signaling by the Receptor Serine Kinase Family (1994)

AN EMERGING theme in cell signaling research is the multifunctional nature of many growth factors and cytokines. Proteins purified based on distinct activities are often found to have identical structures; furthermore, different members of large growth factor families have similar, although subtly distinct, effects on diverse sets of cells. Such related factors often have related receptors, activation of which turns on common cellular signaling pathways. Understanding both the specificity and the overlap of growth factor signaling will involve elucidation of the unique and shared features of those receptors and their intracellular targets. The activins are growth and differentiation factors that are produced by, and exert effects on, a broad range of cells and tissues (reviewed in Refs. 1–5). With the cloning of several activin receptors, as well as the development of biological models for assessing activin and activin receptor function, substantial progress has been made in understanding the mechanism of action of these potent molecules.
The matricellular protein SPARC is internalized in Sertoli, Leydig, and germ cells during testis differentiation (2006)

The gene encoding the matricellular protein secreted protein, acidic and rich in cysteine (SPARC) was identified in a screen for genes expressed sex-specifically during mouse gonad development, as being strongly upregulated in the male gonad from very early in testis development. We present here a detailed analysis of SPARC gene and protein expression during testis development, from 11.5 to 15.5 days post coitum (dpc). Section in situ hybridization analysis revealed that SPARC mRNA is expressed by the Sertoli cells in the testis cords and the fetal Leydig cells, found within the interstitial space between the testis cords. Immunodetection with anti-SPARC antibody showed that the protein was located inside the testis cords, within the cytoplasm of Sertoli and germ cells. In the interstitium, SPARC was present intracellularly within the Leydig cells. The internalization of SPARC in Sertoli, Leydig, and germ cells suggests that it plays an intracellular regulatory role in these cell types during fetal testis development.
Bioartificial Cartilage (2000)

Cartilage is a highly differentiated tissue. Its three-dimensional composition of cells and matrix is able to resist intensive mechanical loads. The capacity of cartilage tissue for regeneration is limited. Chondrocytes are responsible for matrix production of cartilage tissue. Enzymatic isolation and expansion of chondrocytes with cell culture techniques has been improved in the last years. These cells can be cultured on different three-dimensional culture systems suitable for transplantation to repair localized cartilage defects. Two types of bioresorbable polymer fleece matrices (PLLA and a composite fleece of polydioxanone and polyglactin) and lyophilized dura as a biological carrier are tested. Phenotypic and morphological appearance of the cultured articular rabbit chondrocytes is preserved on all three types of transport media. Production of glycosaminoglycans has been shown by Alcian blue staining, production of collagen by azan staining. Chondroitin 4- and 6-sulfate are detected immunohistochemically in the created constructs. The different carriers have specific characteristics regarding their suitability for the creation of bioartificial cartilage. This tissue is transplantable into articular cartilage defects and could, therefore, improve the minor intrinsic healing capacity of cartilage tissue.