gebhart/patrepeval huggingface dataset:
Constructing Ordered Sensitized Heterojunctions: Bottom-Up Electrochemical Synthesis of p-Type Semiconductors in Oriented n-TiO2 Nanotube Arrays (2009)

Fabrication of efficient semiconductor-sensitized bulk heterojunction solar cells requires the complete filling of the pore system of one semiconductor (host) material with nanoscale dimensions (<100 nm) with a different semiconductor (guest) material. Because of the small pore size and electrical conductivity of the host material, it is challenging to employ electrochemical approaches to fill the entire pore network. Typically, during the electrochemical deposition process, the guest material blocks the pores of the host, precluding complete pore filling. We describe a general synthetic strategy for spatially controlling the growth of p-type semiconductors in the nanopores of electrically conducting n-type materials. As an illustration of this strategy, we report on the facile electrochemical deposition of p-CuInSe(2) in nanoporous anatase n-TiO(2) oriented nanotube arrays and nanoparticle films. We show that by controlling the ambipolar diffusion length the p-type semiconductors can be deposited from the bottom-up, resulting in complete pore filling.
Specificity and binding properties of the blood group A reactive hemagglutinin from Helix pomatia (1971)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpecificity and binding properties of the blood group A reactive hemagglutinin from Helix pomatiaElvin A. Kabat and Sten HammarstromCite this: Biochemistry 1971, 10, 9, 1684–1692Publication Date (Print):April 1, 1971Publication History Published online1 May 2002Published inissue 1 April 1971https://pubs.acs.org/doi/10.1021/bi00785a028https://doi.org/10.1021/bi00785a028research-articleACS PublicationsRequest reuse permissionsArticle Views81Altmetric-Citations96LEARN 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
High capacity image steganographic model (2000)

Steganography is an ancient art of conveying messages in a secret way that only the receiver knows the existence of a message. So a fundamental requirement for a steganographic method is imperceptibility; this means that the embedded messages should not be discernible to the human eye. There are two other requirements, one is to maximise the embedding capacity, and the other is security. The least-significant bit (LSB) insertion method is the most common and easiest method for embedding messages in an image. However, how to decide on the maximal embedding capacity for each pixel is still an open issue. An image steganographic model is proposed that is based on variable-size LSB insertion to maximise the embedding capacity while maintaining image fidelity. For each pixel of a grey-scale image, at least four bits can be used for message embedding. Three components are provided to achieve the goal. First, according to contrast and luminance characteristics, the capacity evaluation is provided to estimate the maximum embedding capacity of each pixel. Then the minimum-error replacement method is adapted to find a grey scale as close to the original one as possible. Finally, the improved grey-scale compensation, which takes advantage of the peculiarities of human visual system, is used to eliminate the false contouring effect. Two methods, pixelwise and bitwise, are provided to deal with the security issue when using the proposed model. Experimental results show effectiveness and efficiency of the proposed model.
Using Droplets of Nematic Liquid Crystal To Probe the Microscopic and Mesoscopic Structure of Organic Surfaces (1999)

We report a simple and general procedure that uses nematic liquid crystals (NLCs) to probe the structure of organic surfaces prepared by molecular self-assembly. The procedure involves placement of a submillimeter-sized droplet of NLC on the surface of a self-assembled monolayer (SAM) of organic molecules and observation of the droplet under illumination with polarized light. Because NLCs are optically anisotropic, polarized light permits characterization of the distortion of the NLC within the droplet, which we demonstrate here to reflect the structure of surfaces on spatial scales that range from the molecular to the mesoscopic. We demonstrate the use of droplets of NLCs (i) to probe the molecular-level structure (Ångstrom-scale) of surfaces by distinguishing between SAMs formed from odd or even chain-length alkanethiols or SAMs coadsorbed from mixtures of long and short alkanethiols; (ii) to probe the nanometer-scale texture of polycrystalline films of gold used to support SAMs, including gold substrates prepared by oblique deposition from a vapor of gold; (iii) to image the micrometer-scale structure of SAMs patterned by using microcontact printing; and (iv) to follow, in situ, reactions on surfaces, using as an example the displacement of a SAM formed from CH3(CH2)6SH by CH3(CH2)15SH dissolved into the NLC. Because either reflection or transmission polarization microscopy can be used to image the NLC drops, this method permits characterization of monolayers of organic molecules on both transparent and opaque substrates. To clarify the relationship between the optical appearance of the NLC droplets, the distortions of NLCs within the droplets, and the orientations of NLCs near SAMs, we report numerical simulations of droplets of NLCs supported on surfaces and calculations of the optical textures of these droplets.
Synthetic matrix metalloproteinase-sensitive hydrogels for the conduction of tissue regeneration: Engineering cell-invasion characteristics (2003)

Synthetic hydrogels have been molecularly engineered to mimic the invasive characteristics of native provisional extracellular matrices: a combination of integrin-binding sites and substrates for matrix metalloproteinases (MMP) was required to render the networks degradable and invasive by cells via cell-secreted MMPs. Degradation of gels was engineered starting from a characterization of the degradation kinetics (k(cat) and K(m)) of synthetic MMP substrates in the soluble form and after crosslinking into a 3D hydrogel network. Primary human fibroblasts were demonstrated to proteolytically invade these networks, a process that depended on MMP substrate activity, adhesion ligand concentration, and network crosslinking density. Gels used to deliver recombinant human bone morphogenetic protein-2 to the site of critical defects in rat cranium were completely infiltrated by cells and remodeled into bony tissue within 4 wk at a dose of 5 microg per defect. Bone regeneration was also shown to depend on the proteolytic sensitivity of the matrices. These hydrogels may be useful in tissue engineering and cell biology as alternatives for naturally occurring extracellular matrix-derived materials such as fibrin or collagen.
Normal Development, Wound Healing, and Adenovirus Susceptibility in β5-Deficient Mice (2000)

Integrins have been shown to play important roles in embryonic development, wound healing, metastasis, and other biological processes. alphavbeta5 is a receptor for RGD-containing extracellular matrix proteins that has been suggested to be important in cutaneous wound healing and adenovirus infection. To examine the in vivo function of this receptor, we have generated mice lacking beta5 expression, using homologous recombination in embryonic stem cells. Mice homozygous for a null mutation of the beta5 subunit gene develop, grow, and reproduce normally. Keratinocytes harvested from beta5(-/-) mice demonstrate impaired migration on and adhesion to the alphavbeta5 ligand, vitronectin. However, the rate of healing of cutaneous wounds is not different in beta5(-/-) and beta5(+/+) mice. Furthermore, keratinocytes and airway epithelial cells obtained from null mice show adenovirus infection efficiency equal to that from wild-type mice. These data suggest that alphavbeta5 is not essential for normal development, reproduction, adenovirus infection, or the healing of cutaneous wounds.
Lightpath communications: an approach to high bandwidth optical WAN's (1992)

An architectural approach that meets high bandwidth requirements by introducing a communication architecture based on lightpaths, optical transmission paths in the network, is introduced. Since lightpaths form the building block of the proposed architecture, its performance hinges on their efficient establishment and management. It is shown that although the problem of optimally establishing lightpaths is NP-complete, simple heuristics provide near optimal substitutes for several of the basic problems motivated by a lightpath-based architecture.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Halftoning with random correlated noise (1992)

The process of digital haiftoning replaces a visually continuous-tone image with a binary image. This procedure must be accomplished in such a way as to give the illusion of multiple gray levels while introducing a minimum amount of artifacts or structure not present in the original continuous-tone image. In this investigation, nonperiodic noise patterns that were uniformly distributed, so as to maintain good continuous-tone reproduction, were generated and used as random halftone screens. The noise patterns also had a prescribed two-dimensional spatial correlation, chosen in an attempt to reduce the undesirable artifacts normally introduced by the halftone process. Noise that has a correlation such that its spectrum is lacking low-frequency power is sometimes referred to as "blue noise." An iterative method of generating random correlated noise patterns is described, and some examples of the resulting halftoned images are presented.
Compromised stability of DNA methylation and transposon immobilization in mosaic Arabidopsis epigenomes (2009)

Transgenerational epigenetic inheritance has been defined by the study of relatively few loci. We examined a population of recombinant inbred lines with epigenetically mosaic chromosomes consisting of wild-type and CG methylation-depleted segments (epiRILs). Surprisingly, transposons that were immobile in the parental lines displayed stochastic movement in 28% of the epiRILs. Although analysis after eight generations of inbreeding, supported by genome-wide DNA methylation profiling, identified recombined parental chromosomal segments, these were interspersed with unexpectedly high frequencies of nonparental methylation polymorphism. Hence, epigenetic inheritance in hybrids derived from parents with divergent epigenomes permits long-lasting epi-allelic interactions that violate Mendelian expectations. Such persistently "unstable" epigenetic states complicate linkage-based epigenomic mapping. Thus, future epigenomic analyses should consider possible genetic instabilities and alternative mapping strategies.
Isolation and Characterization of an RIP (Ribosome-Inactivating Protein)-Like Protein from Tobacco with Dual Enzymatic Activity (2004)

Ribosome-inactivating proteins (RIPs) are N-glycosidases that remove a specific adenine from the sarcin/ricin loop of the large rRNA, thus arresting protein synthesis at the translocation step. In the present study, a protein termed tobacco RIP (TRIP) was isolated from tobacco (Nicotiana tabacum) leaves and purified using ion exchange and gel filtration chromatography in combination with yeast ribosome depurination assays. TRIP has a molecular mass of 26 kD as evidenced by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and showed strong N-glycosidase activity as manifested by the depurination of yeast rRNA. Purified TRIP showed immunoreactivity with antibodies of RIPs from Mirabilis expansa. TRIP released fewer amounts of adenine residues from ribosomal (Artemia sp. and rat ribosomes) and non-ribosomal substrates (herring sperm DNA, rRNA, and tRNA) compared with other RIPs. TRIP inhibited translation in wheat (Triticum aestivum) germ more efficiently than in rabbit reticulocytes, showing an IC50 at 30 ng in the former system. Antimicrobial assays using highly purified TRIP (50 microg mL(-1)) conducted against various fungi and bacterial pathogens showed the strongest inhibitory activity against Trichoderma reesei and Pseudomonas solancearum. A 15-amino acid internal polypeptide sequence of TRIP was identical with the internal sequences of the iron-superoxide dismutase (Fe-SOD) from wild tobacco (Nicotiana plumbaginifolia), Arabidopsis, and potato (Solanum tuberosum). Purified TRIP showed SOD activity, and Escherichia coli Fe-SOD was observed to have RIP activity too. Thus, TRIP may be considered a dual activity enzyme showing RIP-like activity and Fe-SOD characteristics.
Expression of Recombinant Antibodies in Mammalian Cell Lines (2004)

Since the advent of hybridoma technology, mammalian-cell culture has been employed for the expression and high-level production of monoclonal antibodies (MAbs). Recent adaptations in recombinant technology have developed the use of numerous prokaryotic and eukaryotic systems for the expression of heterologous molecules. The major systems used for MAb expression have been reviewed and compared (,), and a number of the key methodologies are detailed within this series. Prokaryotic expression systems offer the potential of high production yields at a substantial reduced cost of goods (see Chapter 14). However, because of the complexity of the protein-folding pathway, bacterial expression has been limited to small antibody fragments, and in some cases may require refolding to produce a biologically active product. Another limitation is that recombinant MAbs expressed in bacteria are aglycosylated and can result in the reduction or loss of biological effector functions (). For large, multidomain molecules such as full-length MAbs or complex recombinant antibody fragments, eukaryotic systems such as mammalian or yeast expression have been utilized. Currently, nine USFDA-licensed Mabs for in vivo human use have been expressed from mammalian-cell culture for commercial production.
Tissue distribution of morphine in the newborns of addicted monkeys and humans. Clinical implications. (1980)

The distribution of morphine in various tissues of 6 addicted monkey fetuses and in 2 infants of drug-dependent mothers (IDDM) show that significant concentrations of the drug are in the gastrointestines (tissue plus content), liver, cerebellum, lungs, heart, spleen and thymus. The high concentration of morphine in the gastrointestinal tract may be secondary to the excretion of the drug through the bile or by the repeated swallowing by the fetus of amniotic fluid which contains morphine (1.9 +/- 1.0 micrograms/dl). Meconium, taken from 2 IDDMs show a significant concentration of morphine for up to 2-3 days after birth. Thus, meconium is a useful material to analyze postnatally for the diagnosis of neonatal narcotic addiction.
Flow cytometric analysis of kappa and lambda light chain expression in evaluation of specimens for B‐cell neoplasia (1996)

Analysis of light chain expression is one of the most important determinations in flow cytometric immunophenotyping of patient specimens. Numerous technical factors, such as antibody choice and cytophilic antibody artifact, impact a laboratory's ability to perform this test. There have been conflicting reports concerning the efficacy of polyclonal versus monoclonal antibodies, as well as methods of circumventing cytophilic antibodies, indicating that a consensus has not been reached on optimal methods for light chain determination. The authors have investigated methods for light chain analysis in 104 normal donors and 366 patient specimens, comparing different anti-light chain antibodies as well as strategies for analysis of specimens with low numbers of monoclonal B cells, admixed polyclonal B cells, or cytophilic antibodies. The patient specimens were either part of the initial diagnostic evaluation of patients with suspected lymphoma, or were performed for staging or assessment of treatment of patients with known B-cell neoplasia. No monoclonality was detected in control specimens, and there was no significant difference in staining with monoclonal verses polyclonal anti-light chain antibodies. In addition, cytophilic antibody did not obscure results in normal controls. Monoclonality was detected in 106 patient specimens, with 89 showing gross involvement with a predominant monoclonal B-cell process. However, in 43% of the grossly monoclonal specimens, there was failure to detect monoclonality with at least one light chain antibody set, with 8% of these cases showing failure with two anti-light chain sets. This indicates the importance of antibody choice in light chain analysis. Cytophilic antibody artifact in monoclonal specimens was easily overcome by appropriate antibody combinations, obviating the need for cytophilic antibody-shedding by incubation at 37°C in fetal calf serum. In 27 patient specimens with low numbers of B cells or admixed polyclonal B cells, a clonal search based on FSC and CD19 or CD20 expression was performed. In 17 of the 27 cases (63%), a small monoclonal population was detected among admixed polyclonal B cells. The authors conclude that multiple strategies are necessary in flow cytometric analysis for B-cell monoclonality. © 1996 Wiley-Liss, Inc. 1 This article is a US Government work and, as such, is in the public domain in the United States of America.
Three-Dimensional Trajectory Assessment of an IVUS Transducer From Single-Plane Cineangiograms: A Phantom Study (2005)

The recovery of the three-dimensional (3-D) path of the transducer used during an intravascular ultrasound (IVUS) examination is of primary importance to assess the exact 3-D shape of the vessel under study. Traditionally, the reconstruction is done by simply stacking the images during the pullback, or more recently using biplane angiography to recover the vessel curvature. In this paper, we explain, how single-plane angiography can be used with two projection models, to perform this task. Two types of projection geometry are analyzed: weak-perspective and full-perspective. In weak-perspective projection geometry, the catheter path can be reconstructed without prior transducer depth information. With full-perspective projection geometry, precise depth location of reference points are needed in order to minimize the error of the recovered transducer angle of incidence. The transducer angulation reconstruction is based on the foreshortening effect as seen from the X-ray images. By comparing the measured to the true transducer length, we are able to get its incidence angle. The transducer trajectory is reconstructed by stitching together the different estimated angulations obtained from each image in a cineangiogram sequence. The method is described and validated on two helical vessel phantoms, giving on average a reconstructed path that is less than 2 mm distant from the true path when using full-perspective projection.
Transcription factor binding and modified histones in human bidirectional promoters (2007)

Bidirectional promoters have received considerable attention because of their ability to regulate two downstream genes (divergent genes). They are also highly abundant, directing the transcription of approximately 11% of genes in the human genome. We categorized the presence of DNA sequence motifs, binding of transcription factors, and modified histones as overrepresented, shared, or underrepresented in bidirectional promoters with respect to unidirectional promoters. We found that a small set of motifs, including GABPA, MYC, E2F1, E2F4, NRF-1, CCAAT, YY1, and ACTACAnnTCC are overrepresented in bidirectional promoters, while the majority (73%) of known vertebrate motifs are underrepresented. We performed chromatin-immunoprecipitation (ChIP), followed by quantitative PCR for GABPA, on 118 regions in the human genome and showed that it binds to bidirectional promoters more frequently than unidirectional promoters, and its position-specific scoring matrix is highly predictive of binding. Signatures of active transcription, such as occupancy of RNA polymerase II and the modified histones H3K4me2, H3K4me3, and H3ac, are overrepresented in regions around bidirectional promoters, suggesting that a higher fraction of divergent genes are transcribed in a given cell than the fraction of other genes. Accordingly, analysis of whole-genome microarray data indicates that 68% of divergent genes are transcribed compared with 44% of all human genes. By combining the analysis of publicly available ENCODE data and a detailed study of GABPA, we survey bidirectional promoters with breadth and depth, leading to biological insights concerning their motif composition and bidirectional regulatory mode.
Immunoglobulin G–mediated Inflammatory Responses Develop Normally in Complement-deficient Mice (1996)

The role of complement in immunoglobulin G-triggered inflammation was studied in mice genetically deficient in complement components C3 and C4. Using the reverse passive Arthus reaction and experimental models of immune hemolytic anemia and immune thrombocytopenia, we show that these mice have types II and III inflammatory responses that are indistinguishable from those of wild-type animals. Complement-deficient and wild-type animals exhibit comparable levels of erythrophagocytosis and platelet clearance in response to cytotoxic anti-red blood cell and antiplatelet antibodies. Furthermore, in the reverse passive Arthus reaction, soluble immune complexes induce equivalent levels of hemmorhage, edema, and neutrophillic infiltration in complement-deficient and wild-type animals. In contrast, mice that are genetically deficient in the expression of Fc receptors exhibit grossly diminished reactions by both cytotoxic antibodies and soluble immune complexes. These studies provide strong evidence that the activation of cell-based Fc gamma R receptors, but not complement, are required for antibody-triggered murine inflammatory responses.