gebhart/patrepeval huggingface dataset:
Tendon response to tensile stress: an ultrastructural investigation of collagen:proteoglycan interactions in stressed tendon. (1995)

Tendons are parallel arrays of collagenous fibres which are specialised to resist and transmit tensile stresses. The response of tendon fibres to tensile stress is age-dependent and complex. Elastic elongation at low stress is accompanied by the disappearance of alternate light and dark bands seen in transmitted polarised light. This region of the stress/strain curve is associated with straightening of fibre 'crimps'. At higher stress, elongation is still elastic and reversible until break point is reached. This behaviour may be associated with straightening of a helical arrangement of collagen fibrils. In addition to the collagen fibrils, there are transverse and longitudinal proteoglycan filaments, many of which bridge and link between the fibrils. We have investigated the effect of various levels of stress from very low up to breaking point on the appearance of the proteoglycan filaments and their relationships with the collagen fibrils. Proteoglycan-collagen fibril interactions in rat and mouse tail and flexor digitorum tendons were visualised by Cupromeronic blue staining, applied to dissected fibres in the resting state and at stresses up to breaking. Proteoglycan filaments were seen to be orthogonally arranged in every D period, probably at the d band in mature tendons. In immature tendons proteoglycan filaments took up more varied orientations, but were mainly orthogonal or axially arranged with respect to the collagen fibrils. Both pictures appeared unchanged after application of stress of any level up to breaking point. Young tendons ruptured at lower stresses than mature tendons. It is suggested that PG bridges between collagen fibrils play a part in transmitting and resisting tensile stresses in tendons, contributing to the strength of the tissue.
Transgenic Mice Demonstrate a Testis-specific Promoter for Lactate Dehydrogenase, LDHC (1998)

The mammalian genome encodes a family of lactate dehydrogenase (LDH) isozymes. Two of these, ldha and ldhb, are expressed ubiquitously. The ldhc gene is active only in the germinal epithelium during spermatogenesis. In our analysis of ldhc gene regulation, we found that a 60-base pair promoter sequence was sufficient for testis-specific expression in an in vitro transcription assay. To confirm these findings, a genomic fragment containing 100 base pairs overlapping the transcription start site was isolated and linked to the Escherichia coli lacZ gene. We report that this genomic fragment drives testis-specific expression in transgenic mice. We conclude that transcription of the transgene and possibly of the endogenous ldhc gene is restricted to leptotene/pachytene primary spermatocytes.
Post-cyclosporine-mediated hypertension and nephropathy: amelioration by vascular endothelial growth factor (2001)

Recent studies have demonstrated a role for microvascular and tubulointerstitial injury in some models of salt-sensitive hypertension. We utilized a model of post-cyclosporin A (CsA) nephropathy and hypertension to test the hypothesis that treatment with an angiogenic factor aimed at ameliorating the microvascular and renal injury would prevent the development of hypertension. CsA was administered with a low-salt diet for 45 days, resulting in a renal lesion characterized by afferent arteriolopathy, focal peritubular capillary loss, and tubulointerstitial fibrosis. Rats were then placed on a high-salt diet and randomized to receive either vascular endothelial growth factor (VEGF(121)) or vehicle for 14 days. Placement of rats with established CsA nephropathy on a high-salt diet results in the rapid development of salt-sensitive hypertension. VEGF(121) treatment resulted in lower blood pressure, and this persisted on discontinuing the VEGF. VEGF(121) treatment was also associated with a decrease in osteopontin expression, macrophage infiltration, and collagen III deposition and markedly stimulated resolution of the arteriolopathy (20.9 +/- 7.8 vs. 36.9 +/- 6.1%, VEGF vs. vehicle, P < 0.05). In conclusion, CsA-associated renal microvascular and tubulointerstitial injury results in the development of salt-sensitive hypertension. Treatment of animals with established CsA nephropathy with VEGF reduces the hypertensive response and accelerates histological recovery. The vascular protective effect of VEGF may be due to the improvement of arteriolopathy. Angiogenic growth factors may represent a novel strategy for treating CsA-associated hypertension and renal disease.
Novel commutation technique of AC–ACconverters (1998)

The AC–AC converter called the matrix converter is very simple in structure and has powerful controllability. However, to date there have been few practical applications, especially in power electronics fields. One of the major reasons is the commutation problem. The paper proposes a novel commutation technique which is very simple to implement. This commutation scheme allows the dead time to avoid current spikes of nonideal switches and at the same time establishes a current path of the inductive load to avoid voltage spikes. Experimental results obtained on a 5 kW prototype are discussed.
Thomas Shelton, Translator, in 1612-14 (1958)

Little is known of Thomas Shelton, the translator of Don Quixote, and the following passage in a letter dated 13 February 1611/12, from William Trumbull, the English Agent in Brussels, reporting home to Lord Salisbury, is therefore particularly interesting:
Effect of Particle Morphology on Emitted Dose of Fatty Acid-Treated Disodium Cromoglycate Powder Aerosols (1997)

These studies assess the quantity and morphology of the emitted aerosolized dose of irregularly shaped disodium cromoglycate particles in the fine particle fraction using in vitro methods. Disodium cromoglycate was treated with a homologous series of saturated fatty acids, between C8 and C18, in a range of concentrations. The products of these treatments were powders with a variety of particle size, shape, and aggregation characteristics. Samples of these powders were loaded in gelatin capsules, generated as aerosols from a Rotahaler and collected in a two-stage liquid impinger or eight-stage inertial impactor. Particles were examined directly by scanning electron microscopy and subsequently the images were analyzed to define morphology. The aerodynamic fine-particle fraction determined by the two-stage impinger increased approximately twofold with lauric acid treatment (0.0317 g/g, 6.7%) and threefold with stearic acid treatment (0.58 g/g; 9.7%) compared with disodium cromoglycate alone (0 g/g, 3.56%). The lauric acid formulation appeared to alter deposition primarily by changing particle morphology. Stearic acid altered particle shape to some extent and the increase in the fine-particle fraction appeared to be attributable to improved particle dispersion properties. The uncontrolled presence of irregular-shaped particles can introduce dosing errors due to effects on dispersion and aerodynamic behavior. Conversely, controlled particle morphology and size may be employed to optimize the dose delivered to the lungs particularly if particle-particle and particle-surface interactions can be minimized.
Cultural Factors in International Economy (2005)

Click to increase image sizeClick to decrease image size Additional informationNotes on contributorsYonghong WuWu Yonghong, Ph. D., associate professor at College of Economics, Sichuan University. Academic interests inolude international economics and area economic studies.AXiao WeiXiao Wei, Ph.D., professor at College of Literature & Journalism, Sichuan University. Academic interests cover the fields of feminine writings and cultural studies.
A variational framework for active and adaptative segmentation of vector valued images (2003)

Much effort has been made in integrating different information in a variational framework to segment images. Recent works on curve propagation were able to incorporate stochastic information (see Paragios, N. and Deriche, R., J. Visual Commun. and Image Representation, 2002; Zhu, S. and Yuille, A., 1996) and prior knowledge on shapes (see Cremers, D. et al., 2002; Rousson M. and Paragios, N., 2002). The information inserted in these studies is most of the time extracted offline. Meanwhile, other approaches have proposed to extract region information during the segmentation process itself (see Chan, T. et al., 2000; Jehan-Besson, S. et al., 2002; Yezzi, A. et al., 1999). Following these new approaches and extending the work of Paragios and Deriche to vector-valued images, we propose an entirely variational framework to approach the segmentation problem. Both the image partition and the statistical parameters for each region are unknown. After a brief reminder on recent segmenting methods, we present a variational formulation obtained from a Bayesian model. After that, we show two different differentiations driving to the same evolution equations. Detailed studies on gray and color images of the 2-phase case follow. We finish with an application to tracking which shows the benefits of our dynamic framework.
Selenium detector with a grid for selenium charge gain (2005)

Amorphous selenium direct-conversion x-ray detectors have been used successfully for full field digital mammography (FFDM) and digital radiography (DR). Such detectors characteristically exhibit high spatial resolution and conversion efficiency that is a function of the applied electric field. At an electric field of 10 volts per micron, about 50 electron volts of photon energy are required to generate an electron-hole pair in a typical amorphous selenium x-ray conversion layer. At FFDM and DR imaging x-ray energies each absorbed photon can generate only about 250 to 1000 electron-hole pairs. Each absorbed x-ray photon is only contributing 4 x 10<sup>-17</sup> to 1.6 x 10<sup>-16</sup> coulombs of imaging charge. On the noise side, detectors operating at room temperature have a basic thermal (kTC) noise of 300 to 600 electrons per pixel from the image charge storage capacitor. Electronic noise from the front-end charge amplifier is also amplified by one plus the ratio of the TFT data line capacitance and the feedback capacitance of the charge amplifier. Medical imaging applications must therefore employ low noise thin film transistor (TFT) arrays, low data line capacitance and low noise charge integration amplifiers to achieve high signal-to-noise ratio (SNR) and detective quantum efficiency (DQE). To achieve quantum-noise limited imaging results with the lowest practical x-ray exposure dose, it is desirable to include an additional low-noise gain stage in the x-ray conversion layer. This is particularly important for the application of dynamic imaging or for tomosynthesis where x-ray dose per frame is very limited. A new structure for an amorphous selenium detector that employs an internal biased gain grid to cause avalanche-gain within the x-ray conversion layer is being proposed. A signal charge amplification of at least 10X can be achieved without introducing excessive noise. Quantum-limited image detection should then be attainable for even very low exposures.
ILK over‐expression in human colon cancer progression correlates with activation of β‐catenin, down‐regulation of E‐cadherin and activation of the Akt–FKHR pathway (2005)

Integrin-linked kinase (ILK) has been implicated in the development and progression of several human malignancies. However, the role of ILK in human colon cancer progression is not well established, neither have its possible in vivo downstream effectors in the disease been identified. We studied, by immunohistochemistry, ILK, beta-catenin, E-cadherin, p-Akt and p-FKHR protein expression in 125 primary colon carcinomas and 45 corresponding lymph node metastases. ILK was expressed in 98.4% of the primary tumours and in 100% of metastatic lesions. The levels of ILK expression correlated strongly with tumour invasion, tumour grade and stage and were significantly higher in metastatic tumours. Activation of beta-catenin, down-regulation of E-cadherin and activation of the Akt-FKHR pathway correlated significantly with both ILK expression and tumour progression parameters. In conclusion, our results suggest that ILK may have an important role in progression of human colon cancer, possibly through in vivo regulation of beta-catenin, E-cadherin and Akt pathways. Our study also provides some evidence implicating p-FKHR in human colon carcinogenesis and ILK signalling.
Threshold current of 670-nm AlGaInP strained quantum well lasers (1994)

By means of gain-current calculations we have examined the factors which determine the threshold current of compressively strained Ga/sub x/In/sub 1-x/P/AlGaInP quantum well lasers for the various well width/composition (x) combinations which give a transition wavelength of 670 nm. In addition to valence band modifications we find that the increasing depth and decreasing width of the well are important in decreasing the current as the strain increases. We reveal the important role of well width fluctuations in devices with high compressive strain.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
A Toolbox of Diverse Promoters Related to Methanol Utilization: Functionally Verified Parts for Heterologous Pathway Expression in <i>Pichia pastoris</i> (2015)

The heterologous expression of biosynthetic pathways for pharmaceutical or fine chemical production requires suitable expression hosts and vectors. In eukaryotes, the pathway flux is typically balanced by stoichiometric fine-tuning of reaction steps by varying the transcript levels of the genes involved. Regulated (inducible) promoters are desirable to allow a separation of pathway expression from cell growth. Ideally, the promoter sequences used should not be identical to avoid loss by recombination. The methylotrophic yeast Pichia pastoris is a commonly used protein production host, and single genes have been expressed at high levels using the methanol-inducible, strong, and tightly regulated promoter of the alcohol oxidase 1 gene (PAOX1). Here, we have studied the regulation of the P. pastoris methanol utilization (MUT) pathway to identify a useful set of promoters that (i) allow high coexpression and (ii) differ in DNA sequence to increase genetic stability. We noticed a pronounced involvement of the pentose phosphate pathway (PPP) and genes involved in the defense of reactive oxygen species (ROS), providing strong promoters that, in part, even outperform PAOX1 and offer novel regulatory profiles. We have applied these tightly regulated promoters together with novel terminators as useful tools for the expression of a heterologous biosynthetic pathway. With the synthetic biology toolbox presented here, P. pastoris is now equipped with one of the largest sets of strong and co-regulated promoters of any microbe, moving it from a protein production host to a general industrial biotechnology host.
Adhesion and growth of endothelial cell on amphiphilic PU/PS IPN surface: Effect of amphiphilic balance and immobilized collagen (2002)

Since natural blood vessels are lined with an endothelial cell (EC) monolayer, it is proposed that synthetic biomaterial surfaces be covered or seeded with endothelial cells for ideal nonthrombogenicity under normal conditions. The effects of the surface energy of hydrophilic-hydrophobic IPN on EC adhesion and growth were investigated. The human umbilical vein endothelial cells (HUVECs) were cultured on polyurethane (PU)/polystyrene (PS) IPN prepared by changing only the amphiphilic balance and controlling the microphase separated surface structure. The collagens were immobilized on the IPN surfaces for enhanced adhesion of HUVECs, and the morphology of the collagens immobilized highly depended on the surface energy of the IPNs. The stranded rope structure of the collagen molecules in the solution state was maintained only on the surface of the IPN with intermediate hydrophilicity. The adhesion and the proliferation of ECs on the nontreated IPN surfaces increased by increasing the hydrophobicity of the IPNs, and they were optimized on the collagen-treated IPN surface having an intermediate hydrophilicity. Finally, platelet adhesion was significantly reduced on the EC-hybridized surface of the IPNs.
Chemical studies of metabolites from Pacific Ocean marine sponges and the starfish Dermasterias imbricata (2008)

A study of biologically active extracts of several Pacific Ocean marine sponges has led to the isolation of eight new and nine previously known natural products. The structures of the compounds were determined by a combination of spectroscopic data analysis and chemical interconversions. In addition, the partial synthesis of imbricatine (3), a cytotoxic metabolite of the starfish Dermasterias imbricata, was accomplished. Crude extracts from the sponge Petrosia contignata collected in Papua New Guinea showed potent cytotoxicity against the murine leukemia L1210 cell line. These extracts yielded contignasterol (24), a new highly oxygenated steroid that inhibited histamine release from rat peritoneal mast cells with an IC50 of 0.8 gM, and petrolactone (37), a new sesquiterpene with the drimane carbon skeleton. The structure of contignasterol, which contains the "unnatural" 1413 proton configuration and a cyclichemiacetal functionality in its side chain, was elucidated via spectroscopic studies of its tetraacetate and its reduction product penta acetate. A known polybrominated diphenylether 41 accounted for the cytotoxicity of the crude extracts. The sponge Acanthella sp. yielded ten sesquiterpenes, four of which were new. Compounds 80-87, 89 and 90 contained isonitrile, isothiocyanate, formamide, carbamate and chloride functional groups. In addition, violacene (88), a halogenated monoterpene previously isolated from the red algae Plocamium violaceum, was isolated from the sponge extracts. The Northeastern Pacific sponge Neoesperiopsis digitata yielded neoesperlactone (96), an eighteen carbon fatty acid derived y-lactone. In addition, the major aromatic component was found to be identical by tic and 1H NMR comparison to commercially obtained p-hydroxybenzaldehyde. The study of the Papua New Guinea sponge Pseudaxinella massa led to the identification of a novel cyclic heptapeptide pseudaxinellin (103) which contained standard protein amino acid residues with the L configuration. The study of two species of marine sponges, Ptilocaulis trachys and Amphimedon sp. , collected at Enewetak lagoon, led to the isolation and identification of the depsipeptide majusculamide C (104)which had previously been found in the blue green alga Lyngbya majuscula collected at Enewetak. The synthetic confirmation of the tetrahydroisoquinoline substructure of the starfish metabolite imbricatine (3) was accomplished using a Pictet-Spengler reaction to couple the starting materials 3-(3,5-dihydroxyphenyl) alanine methyl ester (143) and sodium 3-(4-benzyloxyphenyl) glycidate (141). A series of deprotections and protections on the resulting racemic benzyltetrahydroisoquinoline led to a product 140 that was identical by 1H NMR and mass spectroscopic analysis to the protected Raney nickel reduction product of imbricatine (3).
Inferring networks of diffusion and influence (2010)

Information diffusion and virus propagation are fundamental processes talking place in networks. While it is often possible to directly observe when nodes become infected, observing individual transmissions (i.e., who infects whom or who influences whom) is typically very difficult. Furthermore, in many applications, the underlying network over which the diffusions and propagations spread is actually unobserved. We tackle these challenges by developing a method for tracing paths of diffusion and influence through networks and inferring the networks over which contagions propagate. Given the times when nodes adopt pieces of information or become infected, we identify the optimal network that best explains the observed infection times. Since the optimization problem is NP-hard to solve exactly, we develop an efficient approximation algorithm that scales to large datasets and in practice gives provably near-optimal performance. We demonstrate the effectiveness of our approach by tracing information cascades in a set of 170 million blogs and news articles over a one year period to infer how information flows through the online media space. We find that the diffusion network of news tends to have a core-periphery structure with a small set of core media sites that diffuse information to the rest of the Web. These sites tend to have stable circles of influence with more general news media sites acting as connectors between them.
PHOTOBLEACHING DIFFERENCE ABSORPTION SPECTRA OF HUMAN CONE PIGMENTS: QUANTITATIVE ANALYSIS AND COMPARISON TO OTHER METHODS (1992)

Four human cone pigment apoproteins were expressed by transfection of human tissue culture cells with the corresponding complementary DNA clones. Following reconstitution of the cone pigments by incubation with 11-cis retinal, photobleaching difference absorption spectra were obtained for the blue pigment, the green pigment, and two polymorphic variants of the red pigment. These spectra were analyzed to determine the wavelengths of maximal absorbance and the bandwidths. The recombinant cone pigment spectra were compared to human cone spectral sensitivities and cone pigment absorption spectra determined by microspectrophotometry, single-cell electrophysiology, reflection densitometry, electroretinography, and psychophysical color and brightness matching.
Applications of Anionic Polymerization Research (1998)

The general mechanistic aspects of living alkyllithium-initiated polymerization of styrenes and dienes are presented. The structural variables which can be controlled are discussed including molecular weight and molecular weight distribution. Methods for the synthesis of well-defined block copolymers, star polymers and chain-end functionalized polymers are described. New developments in polymer synthesis using functionalized alkyllithium initiators are presented. The controlled alkyllithium-initiated polymerization of alkyl methacrylates is considered in terms of proper choice of initiator, solvent and temperatures. New additives which permit anionic alkyl methacrylate and acrylate polymerization at higher temperatures are discussed. The anionic polymerization of alkylene oxides (epoxides) is discussed with emphasis on ethylene oxide and propylene oxide. The mechanism and characteristics of anionic polymerization of lactams are also described.
Introduction to Oil Chemistry and Properties (2014)

This chapter is an introduction to petroleum chemistry and properties. The traditional separation of saturate, aromatic, resin, and asphaltene (SARA) oil components is summarized. Details on these groupings and the many compounds within the groupings and their abundance, the typical amounts found in some oils, are given. The common properties of oils are summarized and typical examples given.
Creative Teaching in Colleges and Universities (1964)

Click to increase image sizeClick to decrease image size Additional informationNotes on contributorsJohn Carr DuffJohn Carr Duff is a professor of educational administration, Department of Administration and Supervision, School of Education, New York University.