gebhart/patrepeval huggingface dataset:
Capture and 3D culture of colonic crypts and colonoids in a microarray platform (2013)

Crypts are the basic structural and functional units of colonic epithelium and can be isolated from the colon and cultured in vitro into multi-cell spheroids termed "colonoids". Both crypts and colonoids are ideal building blocks for construction of an in vitro tissue model of the colon. Here we proposed and tested a microengineered platform for capture and in vitro 3D culture of colonic crypts and colonoids. An integrated platform was fabricated from polydimethylsiloxane which contained two fluidic layers separated by an array of cylindrical microwells (150 μm diameter, 150 μm depth) with perforated bottoms (30 μm opening, 10 μm depth) termed "microstrainers". As fluid moved through the array, crypts or colonoids were retained in the microstrainers with a >90% array-filling efficiency. Matrigel as an extracellular matrix was then applied to the microstrainers to generate isolated Matrigel pockets encapsulating the crypts or colonoids. After supplying the essential growth factors, epidermal growth factor, Wnt-3A, R-spondin 2 and noggin, 63 ± 13% of the crypts and 77 ± 8% of the colonoids cultured in the microstrainers over a 48-72 h period formed viable 3D colonoids. Thus colonoid growth on the array was similar to that under standard culture conditions (78 ± 5%). Additionally the colonoids displayed the same morphology and similar numbers of stem and progenitor cells as those under standard culture conditions. Immunofluorescence staining confirmed that the differentiated cell-types of the colon, goblet cells, enteroendocrine cells and absorptive enterocytes, formed on the array. To demonstrating the utility of the array in tracking the colonoid fate, quantitative fluorescence analysis was performed on the arrayed colonoids exposed to reagents such as Wnt-3A and the γ-secretase inhibitor LY-411575. The successful formation of viable, multi-cell type colonic tissue on the microengineered platform represents a first step in the building of a "colon-on-a-chip" with the goal of producing the physiologic structure and organ-level function of the colon for controlled experiments.
Optical mapping approaches to molecular genomics (1997)

A variety of physical mapping methods exist for the analysis of nucleic acids or genomes, including hybridization, sequence tagged site mapping, restriction enzyme fingerprinting, radiation hybrid mapping and optical mapping. Single-molecule approaches offer numerous advantages, including very high resolution, small sample size requirements, and parallel sample processing. The convergence of recent advances in new single molecule techniques, surface chemistry and machine vision technology has contributed to novel approaches to genome analysis.
Tantalum- and Titanium-Based Catalytic Systems for the Synthesis of Hyperbranched Polyethene (2000)

Hyperbranched polyethene was synthesized using a novel TaCl5/alkylaluminum halide catalyst system. The polymers were viscous oils with a ratio of methyl hydrogens/total alkyl hydrogens of 0.25−0.40 and weight-average molecular weights of 600−4000 daltons. Both branching and molecular weight can be varied by changing reaction conditions and catalyst composition. The system can also be modified to synthesize 1-alkenes (principally, 1-hexene). A second system, involving TiCl4/alkylaluminum halide, also gave hyperbranched polyethene, with a ratio of methyl hydrogens/total alkyl hydrogens of 0.10−0.25. Weight-average molecular weights varied from 900 to 1800 daltons. Higher selectivity to liquid product was achieved through the addition of dihydrogen. The mechanism of the formation of branched polyethene appears to involve, for the most part, oligomerization of ethene to 1-alkenes (principally 1-hexene) by a transition metal alkyl species followed by cationic oligomerization of the 1-alkenes by Lewis acidic species. The addition of tetraalkylammonium chloride to the TaCl5/Et3Al system resulted in a change in product selectivity from all polyethene to >65% 1-hexene. The highly selective trimerization of ethene by the tantalum system is unusual.
Über Sauerstoffradikale, XIV. Das 2‐Phenyl‐4.6‐di‐tert.‐butyl‐phenoxyl‐(1) (1960)

Abstract Darstellung, Eigenschaften und Reaktionen des 2‐Phenyl‐4.6‐di‐tert.‐butyl‐phenoxyls‐(1) werden mitgeteilt. Die Bedeutung sterischer Effekte für die Existenz monomerer Aroxyle tritt überzeugend zutage.
The Wnt/β-catenin signaling pathway targets PPARγ activity in colon cancer cells (2005)

Control of colon cell fate in adenocarcinomas is disrupted, in part, due to aberrant Wnt/beta-catenin signaling. The nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARgamma) has been implicated in the development of colon cancers. In the adenomatous polyposis coli multiple intestinal neoplasia (APCMin) mouse cancer model, PPARgamma expression in the colonic mucosa is markedly altered. In addition, PPARgamma protein levels are elevated, possibly through sequestration by activated beta-catenin in colon cancer cell lines. Induction of the Wnt/beta-catenin pathway by LiCl also elevated PPARgamma levels and induced PPARgamma-dependent reporter and endogenous target genes. Mechanistically, PPARgamma, through interactions with beta-catenin and T cell transcription factor (Tcf)-4, may be a determinant of cell fate and is likely a target of the Wnt pathway in cancer cells.
Minimization of Rational Word Functions (1991)

Rational functions from a free monoid into another are characterized by the finiteness of the index of some congruence naturally associated with the function. A sequential bimachine is constructed computing the function, which is completely canonical, and in some sense minimal. This generalizes the Nerode criterion and the minimal automaton of a rational language, and similar results for sequential functions.
High-efficiency switchable flat diffractive ophthalmic lens with three-layer electrode pattern and two-layer via structures (2007)

A general design for switchable, flat, liquid crystal diffractive lens with three-layer electrode pattern and two-layer via structures is reported for near-, intermediate-, and distance-vision corrections of presbyopic eyes. The microfabricated transparent concentric ring electrodes are distributed in two layers and different voltages are applied to each electrode through bus lines in another layer. Connection between the electrodes and the bus lines is achieved by vias (conducting holes for vertical interconnections) in the third dimension. For demonstration, a lens is first tuned with a focal length of 1m (1 diopter add power), eight-level phase modulation, and diffraction efficiency above 92% and then reconfigured to operate as a 2 diopter four-level lens with a diffraction efficiency of 78%. The lens operates with low voltages and a rise time of 150ms. This design methodology allows the aperture needed for practical use and a power-failure-safe configuration.
High sensitivity detection of activated factor IX: application to the analysis of different therapeutical factor IX concentrates and prothrombin complexes. (1998)

A very sensitive and highly reliable test system for the detection of activated coagulation factor IX (FIXa) has been established. This assay system is based on the cleavage of a fluorogenic substrate by activated factor X (FXa) which is generated by FIXa. This assay can be used to process a large number of samples at a time and, being based on the convenient microtiter plate format, can easily be adapted to automated processing for routine screening of large sample numbers. With this assay at hand we determined the FIXa content of different commercially available therapeutic FIX sources, such as high purity FIX (HPFIX) and prothrombin complex concentrates (PCC). Here we demonstrate that PCC from several suppliers do not contain significantly higher levels of FIXa as compared to HPFIX from the same supplier. In fact, there is a tendency for HPFIX to contain more FIXa than PCC. Moreover, HPFIX from certain manufacturers who do not produce PCC are characterized by an exceptionally high content of FIXa. Therefore, the higher thrombogenic potential of PCC which is well documented clinically cannot be explained solely -- if at all -- by an increased content of FIXa. Rather, it will be necessary to identify other components responsible for this phenomenon.
Diodes, Light‐emitting (2004)

Abstract A light‐emitting diode (LED) is a semiconductor device that emits monochromatic ultraviolet, visible, or infrared electromagnetic radiation when an electric current is passed through it. The semiconductor material is a compound or alloy of elements from columns III and V of the periodic table. Light‐emitting diodes are compact, mechanically rugged, energy efficient, are of low voltage, and have long operating lifetimes. For colored lighting applications, the efficiency of LEDs far exceeds that of filtered incandescent sources and they are becoming the dominant technology. LEDs are widely used as indicator lights, for backlighting small displays in electronic equipment, in exterior and interior lighting of automobiles, in large‐area full‐color displays, and for data communication. LEDs will be used for general white‐light illumination purposes to the extent that the energy efficiency improves and higher‐power, higher‐flux devices become available.
A Role for Flavin Monooxygenase-Like Enzymes in Auxin Biosynthesis (2001)

Although auxin is known to regulate many processes in plant development and has been studied for over a century, the mechanisms whereby plants produce it have remained elusive. Here we report the characterization of a dominant Arabidopsis mutant, yucca, which contains elevated levels of free auxin. YUCCA encodes a flavin monooxygenase-like enzyme and belongs to a family that includes at least nine other homologous Arabidopsis genes, a subset of which appears to have redundant functions. Results from tryptophan analog feeding experiments and biochemical assays indicate that YUCCA catalyzes hydroxylation of the amino group of tryptamine, a rate-limiting step in tryptophan-dependent auxin biosynthesis.
Seismic Background Noise and Detection Threshold in the Southern Great Basin Digital Seismic Network (2004)

This study compares predicted seismic thresholds to actual thresholds for a high-resolution, three-component digital network in the southern part of the Great Basin of Nevada, centered on Yucca Mountain, the designated site of a high-level nuclear-waste geologic repository. In order to do this comparison, it was necessary to quantify carefully the statistical properties of noise, including mean, variance, and correlation, and the statistical properties of signals, including mean, variance, and site effects. It was also necessary to relate the noise levels to the long-term average (lta) and the signal levels to the short-term average (sta) used in conventional signal-detector algorithms. Combining these attributes with a random-earthquake simulator enables one to predict the seismic threshold of the network for a given source area.

Initial predicted thresholds for the network were found to be approximately 0.3 to 0.4 magnitude unit less than the actual thresholds achieved by the network. There are several reasons for this, but the major reason seems to be the inability to time small signals that are automatically detected. A predicted threshold map for the network was constructed by accounting for the difference initially seen between predicted and actual thresholds. This map indicates that the network detects all events within 10 km of Yucca Mountain with three or more stations down to a threshold of roughly M L −0.5, whereas events near the fringes of the network are similarly detected down to a threshold of roughly M L +0.5. The simulations show that the network-estimated magnitude is biased upward as true magnitude approaches the threshold; this bias may be as large as roughly +0.3 for events near the threshold.
Activation of measles virus from silently infected human lymphocytes. (1978)

Lymphocytes were incubated with measles virus for 4 days in the absence of a lymphocyte stimulating agent. Such nonstimulated lymphocytes, infected with measles virus, did not express the virus antigens that are detectable by cytotoxic antibodies. Approximately 1 out of 5,000, or even fewer, of such lymphocytes produced virus as demonstrated by the infectious center assay; in the supernate only 10--100 infectious viruses per milliliter were detected. No virus structures could be observed by means of an electron microscope. However, such lymphocytes showed no reaction to phytohemagglutinin (PHA) in terms of DNA synthesis in a subsequent culture in the presence of antibodies against measles to prevent spreading of the infection to other cells. Although stimulation by PHA did not result in a significant increase in [3H]thymidine incorporation, measles virus was activated; 32 h after the addition of PHA nearly 80% of the cells were killed by measles virus antibodies and complement. The number of virus-producing cells increased to approximately 1 in 300 or more, and at 72 h the virus titer in the supernate had risen to 10(6) infectious particles per ml. This reactivation of measles virus was still obtained when PHA was added as late as 8 or more days after the initial infection.
[Gene delivery into human cancer cells via transferrin receptor]. (1998)

At present, vectors widely used for gene transduction are retroviruses and adenoviruses. However, the transduction using these vectors are primarily conducted ex vivo. The direct in vivo gene delivery method to target tumor cells are required. Trials to augment specificity of gene targeting to tumor cells have been in progress including approaches to use modified virus particles by gene technology instead of wild type particles or to take advantage of ligand-receptor or antibody-antigen systems by allowing vector DNAs to bind these ligand and antibodies. Transferrin receptor (TfR) is widely distributed on actively proliferating cells and is therefore an appropriate target for in vivo gene delivery into those cells. We developed a simple method to conjugate biotinylated double-stranded DNA to biotinylated Tf via streptavidin and demonstrated successful transduction of the conjugate into TfR-positive human cancer cells. The present method may provide a novel technique for gene transduction, which may be used especially to transfer various DNA vectors into cells specifically expressing TfR, in vivo as well as in vitro.
High Blood Caffeine Levels in MCI Linked to Lack of Progression to Dementia (2012)

Although both human epidemiologic and animal model studies have suggested that caffeine/coffee protects against Alzheimer's disease, direct human evidence for this premise has been lacking. In the present case-control study, two separate cohorts consisting of 124 total individuals (65-88 years old) were cognitively assessed and a blood sample taken for caffeine/biomarker analysis. Subjects were then monitored for cognitive status over the ensuing 2-4 year period to determine the extent to which initial plasma caffeine/biomarkers levels would be predictive of changes in cognitive status. Plasma caffeine levels at study onset were substantially lower (-51%) in mild cognitive impairment (MCI) subjects who later progressed to dementia (MCI→DEM) compared to levels in stable MCI subjects (MCI→MCI). Moreover, none of the MCI→DEM subjects had initial blood caffeine levels that were above a critical level of 1200 ng/ml, while half of stable MCI→MCI subjects had blood caffeine levels higher than that critical level. Thus, plasma caffeine levels greater than 1200 ng/ml (≈6 μM) in MCI subjects were associated with no conversion to dementia during the ensuing 2-4 year follow-up period. Among the 11 cytokines measured in plasma, three of them (GCSF, IL-10, and IL-6) were decreased in MCI→DEM subjects, but not in stable MCI→MCI subjects with high plasma caffeine levels. Coffee would appear to be the major or perhaps only source of caffeine for such stable MCI patients. This case-control study provides the first direct evidence that caffeine/coffee intake is associated with a reduced risk of dementia or delayed onset, particularly for those who already have MCI.
Haemophilus parahaemolyticus serotypes. Pathogenicity and cross immunity. (1979)

Pigs inoculated intranasally with Haemophilus parahaemolyticus, serotype 2, resisted challenge 3 weeks later with serotypes 2, 4 and 5 without showing clinical symptoms. The pigs were sacrificed 2 days after challenge, and post mortem examination showed a chronic pleuropneumonia from which only serotype 2 was re-isolated. Pigs inoculated intranasally with H. parahaemolyticus, serotype 2, showed no clinical symptoms when challenged 3 weeks later with serotype 1. Post mortem examination revealed a chronic pleuropneumonia with areas of necrosis from which H. parahaemolyticus, serotype 2, was re-isolated, but also small areas of a more acute fibrinous pneumonia from which serotype 1 was re-isolated. The control pig inoculated with only serotype 1 showed a severe acute fibrinous pleuropneumonia. The results indicate that a considerable cross immunity exists between the various serotypes of H. parahaemolyticus.
Histocompatibility-Linked Immune Response Genes (1972)

Publisher Summary This chapter provides information on histocompatibility-linked immune response genes. The genetic study of the capacity to form specific immune responses has revealed that the recognition of antigens as immunogens by individual animals and inbred strains is governed by the product of individual dominant genes located in the genome in close relationship with the genes coding for the molecules bearing the major histocompatibility specificities. These genes are termed as “histocompatibility,” or “H-linked Ir genes.” The presence of relevant genes permit immune responses to be formed, characterized by cellular immunity and antibody synthesis against the determinants on the antigens concerned. Three types of antigens are most useful in the identification of H-linked Ir genes: (1) synthetic polypeptides with limited structural heterogeneity; (2) alloantigens that differ slightly from their autologous counterparts, and (3) complex multideterminants antigens administered in limiting immunizing doses in conditions where only the most immunogenic determinants are recognized. Thus, the discovery of specific H-linked Ir genes depends upon experiments wherein the immunological system is presented with a challenge of highly restricted heterogeneity and specificity. The chapter presents a description of the specific immune responses that are under the control of H-linked Ir genes in guinea pigs, mice, and rats.
Hydrolytic reactions of carbyl sulfate (1974)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrolytic reactions of carbyl sulfateDavid L. Wooton and William G. LloydCite this: J. Org. Chem. 1974, 39, 14, 2112–2114Publication Date (Print):July 1, 1974Publication History Published online1 May 2002Published inissue 1 July 1974https://pubs.acs.org/doi/10.1021/jo00928a031https://doi.org/10.1021/jo00928a031research-articleACS PublicationsRequest reuse permissionsArticle Views139Altmetric-Citations6LEARN 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
Some effects of jet-lag and their alleviation by melatonin (1987)

Abstract Seventeen healthy volunteers (10 women and 7 men, aged 29-68) were flown from London to San Francisco between 20 November 1985 and 25 January 1986 and remained there for 14 days prior to flight home. Subjects took melatonin (N = 8, 5 women, 3 men) or placebo in a double-blind design, at 18.00h local time for three days before the return flight and at bedtime (22.00-24.00h) in Great Britain for four days. For three days before departure and on days 1-7,14,15, 21 and 22 after their return subjects collected 6-hourly sequential urine samples and kept a daily sleep log. They recorded mood and oral temperature 2 hourly and performed logical reasoning and letter cancellation tests 4 hourly from 08.00h (or wake up time) to 24.00h (or bedtime) whichever was the earlier. Urine was also collected for 48 h prior to departure from the U.S.A‥ On day 7 after their return subjects rated ‘jet lag’ (10 cm visual analogue scale—VAS) from 0 (insignificant) to 100 (very bad). Melatonin significantly improved ‘jet lag’ (p= 0.009). Comparisons by ANOVA between jet-lagged placebo subjects (N = 7) and melatonin (N = 8) showed decreased sleep latency with melatonin (p= 0.0397) which correlated positively with jet lag ratings, p< 0.001. Sleep quality was significantly improved in the melatonin group and correlated negatively with jet-lag ratings (p<0.001). No important differences were found in temperature, or performance data. Baseline differences were present in some performance ratings but no other variables. Melatonin treated subjects tended to be more alert than placebo subjects, especially at bedtime. They were also less depressed. Endogenous melatonin and Cortisol rhythms resyn-chronized more rapidly in melatonin subjects (p= 0.0216 and p= 0.0299 respectively, absolute acrophase shifts). Cortisol rhythms indicated adaptation to U.S.A. time in 14 days. These data suggest that MT can alleviate jet-lag after Eastward flight over eight time zones. Presumably its affects are primarily on sleep latency, quality, and directly or indirectly on some hormonal rhythms.
Long-Term and Accelerated Life Testing of a Novel Single-Wafer Vacuum Encapsulation for MEMS Resonators (2006)

We have developed a single-wafer vacuum encapsulation for microelectromechanical systems (MEMS), using a thick (20-mum) polysilicon encapsulation to package micromechanical resonators in a pressure <1 Pa. The encapsulation is robust enough to withstand standard back-end processing steps, such as wafer dicing, die handling, and injection molding of plastic. We have continuously monitored the pressure of encapsulated resonators at ambient temperature for more than 10 000 h and have seen no measurable change of pressure inside the encapsulation. We have subjected packaged resonators to >600 cycles of -50 to 80degC, and no measurable change in cavity pressure was seen. We have also performed accelerated leakage tests by driving hydrogen gas in and out of the encapsulation at elevated temperature. Two results have come from these hydrogen diffusion tests. First, hydrogen diffusion rates through the encapsulation at temperatures 300-400degC have been determined. Second, the package was shown to withstand multiple temperature cycles between room and 300-400degC without showing any adverse affects. The high robustness and stability of the encapsulation can be attributed to the clean, high-temperature environment during the sealing process