gebhart/patrepeval huggingface dataset:
Bone Regeneration in a Rabbit Critical-Sized Skull Defect Using Autologous Adipose-Derived Cells (2008)

Repair of substantial cranial defects in adults and children may be compromised due to limitations in donor bone stocks for autologous grafts. We evaluated the capability of autologous adipose-derived mesenchymal cells (ADCs) in combination with polylactic acid (PLA) scaffolds to regenerate bone in a critical-sized skull defect. Thirty adult New Zealand White rabbits were divided into six groups of five animals each: (1) PLA alone (control), (2) fibronectin-coated PLA, (3) PLA with ADCs, (4) fibronectin-coated PLA with ADCs, (5) PLA with osteogenically induced ADCs (osADCs), and (6) fibronectin-coated PLA with osADCs. All the animals were humanely killed after 6 weeks. X-ray, histology, and histomorphometric analysis were performed to evaluate the new bone formation inside the PLA scaffold. Radiographically and histomorphometrically, the groups in which the PLA was not fibronectin coated showed no bone formation in contrast to the fibronectin-coated groups (Gp1 vs. Gp2, p < 0.0005); the group treated with osteo-induced ADCs and fibronectin (Gp6) showed significantly more bone formation than the group treated with undifferentiated ADCs (Gp4) and the group treated without cells (Gp5, p < 0.0005, in both cases). These data indicate that the surface treatment with fibronectin promotes bone formation within the scaffold, and that autologous, osteo-induced adipose-derived cells enhance bone formation if seeded into a fibronectin-treated PLA scaffold.
Fountain codes for lossless data compression (2005)

This paper proposes a universal variable-length lossless compression algorithm based on fountain codes. The compressor concatenates the Burrows-Wheeler block sorting transform (BWT) with a fountain encoder, together with the closed-loop iterative doping algorithm. The decompressor uses a Belief Propagation algorithm in conjunction with the iterative doping algorithm and the inverse BWT. Linear-time compression/decompression complexity and competitive performance with respect to state-of-the-art compression algorithms are achieved.
Prevalence of Porphyromonas gingivalis and Periodontal Health Status (1998)

Periodontitis is a common, progressive disease that eventually affects the majority of the population. The local destruction of periodontitis is believed to result from a bacterial infection of the gingival sulcus, and several clinical studies have provided evidence to implicate Porphyromonas gingivalis. If P. gingivalis is a periodontal pathogen, it would be expected to be present in most subjects with disease and rarely detected in subjects with good periodontal health. However, in most previous studies, P. gingivalis has not been detected in the majority of subjects with disease, and age-matched, periodontally healthy controls were not included for comparison. The purpose of the study reported here was to compare the prevalence of P. gingivalis in a group with periodontitis to that of a group that is periodontally healthy. A comprehensive sampling strategy and a sensitive PCR assay were used to maximize the likelihood of detection. The target sequence for P. gingivalis-specific amplification was the transcribed spacer region within the ribosomal operon. P. gingivalis was detected in only 25% (46 of 181) of the healthy subjects but was detected in 79% (103 of 130) of the periodontitis group (P < 0.0001). The odds ratio for being infected with P. gingivalis was 11.2 times greater in the periodontitis group than in the healthy group (95% confidence interval, 6.5 to 19.2). These data implicate P. gingivalis in the pathogenesis of periodontitis and suggest that P. gingivalis may not be a normal inhabitant of a periodontally healthy dentition.
Balancing the immune response in the brain: IL-10 and its regulation (2016)

The regulation of IL-10 production by central nervous cells remains a challenging field. Answering the many remaining outstanding questions will contribute to the design of targeted approaches aiming at controlling deleterious inflammation in the brain.
Improving the Power Line Communication Signal-to-Noise Ratio During a Resistive Load Commutation (2009)

In any cable or power line communications, impulse noise is known to be the most difficult noise to filter. In particular, non periodic asynchronous impulse noise is impossible to predict. Under such noise conditions, the OFDM1 symbol generally used in PLC2 is corrupted. To overcome this problem, the signal-to-noise ratio is generally improved by detecting and/or filtering the noise. This leads however to heavy detection and computing time in comparison with the disturbance duration. In this paper, we study the parameters of the noise generated by a load commutation and propose a new approach that consists in controlling the commutation instant of the load. This approach reduces by up to 15 dB the asynchronous impulsive noise emitted by a resistive load in a 40.96-µs typical Homeplug AV3 OFDM symbol duration. Synchronisation is integrated in electronic commutation system. Results show that the load value does not influence the magnitude of the impulse noise.
Autocorrelation and regularization in digital images. I. Basic theory (1988)

Spatial structure occurs in remotely sensed images when the imaged scenes contain discrete objects that are identifiable in that their spectral properties are more homogeneous within than between them and other scene elements. The spatial structure introduced is manifest in statistical measures such as the autocovariance function and variogram associated with the scene, and it is possible to formulate these measures explicitly for scenes composed of simple objects of regular shapes. Digital images result from sensing scenes by an instrument with an associated point spread function (PSF). Since there is averaging over the PSF, the effect, termed regularization, induced in the image data by the instrument will influence the observable autocovariance and variogram functions of the image data. It is shown how the autocovariance or variogram of an image is a composition of the underlying scene covariance convolved with an overlap function, which is itself a convolution of the PSF. The functional form of this relationship provides an analytic basis for scene inference and eventual inversion of scene model parameters from image data.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
A Two-domain Structure of One Subunit Explains Unique Features of Eukaryotic Hydratase 2 (2004)

2-Enoyl-CoA hydratase 2, a part from multifunctional enzyme type 2, hydrates trans-2-enoyl-CoA to 3-hydroxyacyl-CoA in the (3R)-hydroxy-dependent route of peroxisomal beta-oxidation of fatty acids. Unliganded and (3R)-hydroxydecanoyl coenzyme A-complexed crystal structures of 2-enoyl-CoA hydratase 2 from Candida tropicalis multifunctional enzyme type 2 were solved to 1.95- and 2.35-A resolution, respectively. 2-Enoyl-CoA hydratase 2 is a dimeric, alpha+beta protein with a novel quaternary structure. The overall structure of the two-domain subunit of eukaryotic 2-enoyl-CoA hydratase 2 resembles the homodimeric, hot dog fold structures of prokaryotic (R)-specific 2-enoyl-CoA hydratase and beta-hydroxydecanoyl thiol ester dehydrase. Importantly, though, the eukaryotic hydratase 2 has a complete hot dog fold only in its C-domain, whereas the N-domain lacks a long central alpha-helix, thus creating space for bulkier substrates in the binding pocket and explaining the observed difference in substrate preference between eukaryotic and prokaryotic enzymes. Although the N- and C-domains have an identity of <10% at the amino acid level, they share a 50% identity at the nucleotide level and fold similarly. We suggest that a subunit of 2-enoyl-CoA hydratase 2 has evolved via a gene duplication with the concomitant loss of one catalytic site. The hydrogen bonding network of the active site of 2-enoyl-CoA hydratase 2 resembles the active site geometry of mitochondrial (S)-specific 2-enoyl-CoA hydratase 1, although in a mirror image fashion. This arrangement allows the reaction to occur by similar mechanism, supported by mutagenesis and mechanistic studies, although via reciprocal stereochemistry.
Efficiency droop in nitride‐based light‐emitting diodes (2010)

Abstract Nitride‐based light‐emitting diodes (LEDs) suffer from a reduction (droop) of the internal quantum efficiency with increasing injection current. This droop phenomenon is currently the subject of intense research worldwide, as it delays general lighting applications of GaN‐based LEDs. Several explanations of the efficiency droop have been proposed in recent years, but none is widely accepted. This feature article provides a snapshot of the present state of droop research, reviews currently discussed droop mechanisms, contextualizes them, and proposes a simple yet unified model for the LED efficiency droop. magnified image Illustration of LED efficiency droop (details in Fig. 13 ).
Neuronal Cell Surface Molecules Mediate Specific Binding to Rabies Virus Glycoprotein Expressed by a Recombinant Baculovirus on the Surfaces of Lepidopteran Cells (1998)

The existence of specific rabies virus (RV) glycoprotein (G) binding sites on the surfaces of neuroblastoma cells is demonstrated. Spodoptera frugiperda (Sf21) cells expressing G of the RV strain CVS (Gcvs-Sf21 cells) bind specifically to neuroblastoma cells of different species but not to any other cell type (fibroblast, myoblast, epithelial, or glioma). Attachment to mouse neuroblastoma NG108-15 cells is abolished by previous treatment of Gcvs-Sf2 cells with anti-G antibody. Substitutions for lysine at position 330 and for arginine at position 333 in RV G greatly reduce interaction between Gcvs-Sf21 cells and NG108-15 cells. These data are consistent with in vivo results: an avirulent RV mutant bearing the same double mutation is not able to infect sensory neurons or motoneurons (P. Coulon, J.-P. Ternaux, A. Flamand, and C. Tuffereau, J. Virol. 72:273-278, 1998) after intramuscular inoculation into a mouse. Furthermore, infection of NG108-15 cells by RV but not by vesicular stomatitis virus leads to a reduction of the number of binding sites at the neuronal-cell surface. Our data strongly suggest that these specific attachment sites on neuroblastoma cells represent a neuronal receptor(s) used by RV to infect certain types of neurons in vivo.
Epigenetic differences between naïve and primed pluripotent stem cells (2017)

It has been 8 years since the concept of naïve and primed pluripotent stem cell states was first proposed. Both are states of pluripotency, but exhibit slightly different properties. The naïve state represents the cellular state of the preimplantation mouse blastocyst inner cell mass, while the primed state is representative of the post-implantation epiblast cells. These two cell types exhibit clearly distinct developmental potential, as evidenced by the fact that naïve cells are able to contribute to blastocyst chimeras, while primed cells cannot. However, the epigenetic differences that underlie the distinct developmental potential of these cell types remain unclear, which is rather surprising given the large amount of active investigation over the years. Elucidating such epigenetic differences should lead to a better understanding of the fundamental properties of these states of pluripotency and the means by which the naïve-to-primed transition occurs, which may provide insights into the essence of stem cell commitment.
A New Classification of Prodrugs: Regulatory Perspectives (2009)

Many therapeutic agents are manufactured and administered in prodrug forms. In this paper, a new classification system for prodrugs is proposed to provide useful information about where in the body a prodrug is converted to the active drug. In this system, prodrugs are classified into Type I or Type II and the respective Subtypes IA, IB, IIA, IIB or IIC based on their sites of conversion into the final active drug form. For Type I prodrugs, conversion occurs intracellularly (e.g., antiviral nucleoside analogs, lipid-lowering statins), whereas conversion of Type II prodrugs occurs extracellularly, for examples in digestive fluids, systemic circulation or other extracellular body fluids (e.g., etoposide phosphate, valganciclovir, fosamprenavir). Type IA prodrugs refer to those that are converted at the cellular targets of therapeutic actions, whereas Type IB prodrugs' conversion occurs in the primary metabolic tissues such as liver, gut, or lung. For Type II prodrugs, the conversion process could either take place extracellularly in the milieu of gastrointestinal fluids (Type IIA), in the systemic circulation and/or other systemic extracellular fluid compartments (Type IIB), or near therapeutical target cells (Type IIC). A prodrug may belong to multiple categories and be recognized as a Mixed-Type prodrug. For example a prodrug may be converted both in target cells and metabolic tissues such as liver (i.e., named as a Type IA/IB prodrug), or one converted in both GI fluids and systemic circulations (i.e., named as a Type IIA/IIB prodrug). The Mixed-Type compound can be further distinguished as a Parallel Mixed-Type or Sequential Mixed-Type prodrug depending on the conversion processes that proceed with, either in concurrent or in sequential steps. Because traditional analysis of drug actions has always been focused on the site of action and mode of action, the proposed classification of prodrugs based on cellular locations of conversion is in line with current thought processes of regulatory review and risk assessment of both prodrug and active drug. By gaining insights regarding the site of action through prodrug nomenclature, risk benefit evaluation can be made more efficiently because both information on kinetics and impact of tissues involved are adequately revealed through prodrug subtype designated. In conclusion, the new system of classification will add to existing knowledge of prodrug classifications, and will provide improved insight into the contributory roles of both prodrug and active drug in the product's efficacy and safety, and their risk-benefit assessment.
Sequence-targeted photochemical modifications of nucleic acids by complementary oligonucleotides covalently linked to porphyrins (1990)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSequence-targeted photochemical modifications of nucleic acids by complementary oligonucleotides covalently linked to porphyrins Trung Le Doan, Daniele Praseuth, Loic Perrouault, Marcel Chassignol, Nguyen Thanh Thuong, and Claude HeleneCite this: Bioconjugate Chem. 1990, 1, 2, 108–113Publication Date (Print):March 1, 1990Publication History Published online1 May 2002Published inissue 1 March 1990https://pubs.acs.org/doi/10.1021/bc00002a004https://doi.org/10.1021/bc00002a004research-articleACS PublicationsRequest reuse permissionsArticle Views119Altmetric-Citations35LEARN 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
Integration of DNA fragments by illegitimate recombination in Saccharomyces cerevisiae. (1991)

DNA fragments (generated by BamHI treatment) with no homology to the yeast genome were transformed into Saccharomyces cerevisiae. When the fragments were transformed in the presence of the BamHI enzyme, they integrated into genomic BamHI sites. When the fragments were transformed in the absence of the enzyme, they integrated into genomic G-A-T-C sites. Since the G-A-T-C sequence is present at the ends of BamHI fragments, this results indicates that four base pairs of homology are sufficient for some types of mitotic recombination.
Molecular Cloning and Functional Characterization of Murine Sphingosine Kinase (1998)

Sphingosine-1-phosphate (SPP) is a novel lipid messenger that has dual function. Intracellularly it regulates proliferation and survival, and extracellularly, it is a ligand for the G protein-coupled receptor Edg-1. Based on peptide sequences obtained from purified rat kidney sphingosine kinase, the enzyme that regulates SPP levels, we report here the cloning, identification, and characterization of the first mammalian sphingosine kinases (murine SPHK1a and SPHK1b). Sequence analysis indicates that these are novel kinases, which are not similar to other known kinases, and that they are evolutionarily conserved. Comparison with Saccharomyces cerevisiae and Caenorhabditis elegans sphingosine kinase sequences shows that several blocks are highly conserved in all of these sequences. One of these blocks contains an invariant, positively charged motif, GGKGK, which may be part of the ATP binding site. From Northern blot analysis of multiple mouse tissues, we observed that expression was highest in adult lung and spleen, with barely detectable levels in skeletal muscle and liver. Human embryonic kidney cells and NIH 3T3 fibroblasts transiently transfected with either sphingosine kinase expression vectors had marked increases (more than 100-fold) in sphingosine kinase activity. The enzyme specifically phosphorylated D-erythro-sphingosine and did not catalyze the phosphorylation of phosphatidylinositol, diacylglycerol, ceramide, D,L-threo-dihydrosphingosine or N, N-dimethylsphingosine. The latter two sphingolipids were competitive inhibitors of sphingosine kinase in the transfected cells as was previously found with the purified rat kidney enzyme. Transfected cells also had a marked increase in mass levels of SPP with a concomitant decrease in levels of sphingosine and, to a lesser extent, in ceramide levels. Our data suggest that sphingosine kinase is a prototypical member of a new class of lipid kinases. Cloning of sphingosine kinase is an important step in corroborating the intracellular role of SPP as a second messenger.
Normal wound healing compared to healing within porous Dacron implants (1988)

This study examined the hypothesis that healing within porous implants differs from that in normal connective tissue. Special attention was given to extracellular components including collagen, reticular fibers, and ground substance, and to enzymes associated with activated macrophages. Using Dacron velour and the rabbit as host, the healing of normal connective tissue and that of the tissue/implant interface were histologically compared 10 and 28 days postimplantation. The results exhibited significant differences between connective tissue healing, implant capsule formation, and granulation tissue generation. The healing of connective tissue and implant capsule formation were essentially complete at 28 days. However, tissue inside the implant was qualitatively different and did not significantly change between 10 and 28 days. It was characterized by macrophages and giant cells, a predominantly acid mucopolysaccharide ground substance, and qualitatively fewer and less well defined collagen and reticular fibers were observed than in normal wound healing. Thus we conclude that the connective tissue inside Dacron velour does not resemble normal connective tissue after 10 or 28 days of healing. Furthermore, the collagen never fully matures into orderly bundles, a phenomenon which may be related to an altered mucopolysaccharide composition and a diminished reticular network. The lysosomal enzymatic activity of the macrophages and perhaps the giant cells at the tissue/implant interface may be linked to these differences.
A Comparison of Automatic Vehicle Tracking Systems (1974)

Many segments of the transportation industry will benefit from an automatic vehicle tracking and monitoring system. Such a system automatically reports the position of a number of vehicles (groundborne, seaborne and airborne) to a central location. Dispatchers, such as police, bus or taxi, could more efficiently use their resources if they could track the location of the vehicles they are controlling. Ships on a seaway could be more efficiently scheduled into docks or locks if their position and speed were being tracked. Trucking companies could more effectively protect their cargos from theft or hi-jacking if they could monitor the location of the trucks. A few automatic vehicle tracking systems have been implemented. As an example the Chicago Metropolitan Bus System has been evaluating a system. The Urban Mass Transportation Administration of the Department of Transportation is conducting a program to determine the best system for “Automatic Vehicle Monitoring”. Tests have been conducted of at least four RF positioning systems to determine which of these technologies meet DOT/UMTA requirements. The next phase will be a trial implementation of one of these tested systems. This paper summarizes the stated user requirements as determined by DOT/UMTA, St. Lawrence Seaway Authority, Forestry Service, Railroads and others. These user requirements include positioning accuracy, number of vehicles to be handled simultaneously, coverage area and implementation and operating costs. A comparison of several technologies is then presented. A very brief description of each system, including Loran–C, Differential Omega, RF trilateration, sign-post and dead reckoning is presented with a comparison of the advantages and disadvantages in view of the user requirements. A cost comparison is presented which compares the implementation and operating costs of the different systems. Overall efficiency is compared; i.e. cost per user, rf spectrum efficiency, etc. A summary of this comparison concludes that a Loran–C Automatic Tracking System is the most efficient alternative to the requirement for an automatic vehicle positioning system. A description of a Loran–C System then follows, which briefly describes the major system components. Implementation and operating costs are presented. The solution to the two prime problems of a Loran AVM System are described—namely a low-cost receiver and the availability of relatively low-cost, small, Loran–C chains presently in production.