gebhart/patrepeval huggingface dataset:
Covalent Organic Frameworks as a Platform for Multidimensional Polymerization (2017)

The simultaneous polymerization and crystallization of monomers featuring directional bonding designs provides covalent organic frameworks (COFs), which are periodic polymer networks with robust covalent bonds arranged in two- or three-dimensional topologies. The range of properties characterized in COFs has rapidly expanded to include those of interest for heterogeneous catalysis, energy storage and photovoltaic devices, and proton-conducting membranes. Yet many of these applications will require materials quality, morphological control, and synthetic efficiency exceeding the capabilities of contemporary synthetic methods. This level of control will emerge from an improved fundamental understanding of COF nucleation and growth processes. More powerful characterization of structure and defects, improved syntheses guided by mechanistic understanding, and accessing diverse isolated forms, ranging from single crystals to thin films to colloidal suspensions, remain important frontier problems.
Effects of Xe Gas on Segmental Motion in a Polymer Blend As Studied by <sup>13</sup>C and <sup>129</sup>Xe High-Pressure MAS NMR (2001)

13C and 129Xe high-pressure (HP) magic-angle spinning (MAS) NMR was applied to a polystyrene/poly(vinyl methyl ether) (PS/PVME) = 50/50 blend under Xe pressure range of 0.0−4.0 MPa for investigating effects of the dissolved Xe atoms on the segmental motions of the individual component polymers. It is shown that the chemical shift of 129Xe dissolved in the blend moves to the high-frequency side and the line becomes narrow with increasing Xe gas pressure. The 129Xe higher-frequency shift is explained in terms of an increase of the Xe concentration in the blend. The line narrowing suggests that the Xe atomic diffusion is enhanced with increasing Xe concentration in the blend. On the other hand, the 13C line widths under MAS and 1H dipolar decoupling (DD) evidently show that the dissolved Xe atoms enhance the segmental motions of the individual component polymers (plasticization effect) at Xe gas pressures higher than 1.0 MPa. Furthermore, the observed pressure and temperature dependence of the line widths demonstrates that the motional frequency difference between PS and PVME at high pressures is less than that observed at high temperatures. It is concluded that the dissolved Xe atoms not only enhance the segmental motions of PS and PVME but also work to reduce the motional heterogeneity in the blend.
Spatial Integration in Construction (2002)

Work in construction always requires moving within, and interacting with, a complex environment while handling heavy materials and building elements to be joined, inserted, or aligned. Modern design software is able to digitally model all of those elements in their spatially correct configuration, and without interference. When it comes to the actual construction, however, the spatial models do not find any use. Twenty years after the manufacturing industry began using electronic design data to control their machinery, construction is also getting ready to move away from its longstanding tradition of working with paper-based blueprints. The newest steps on the path toward the use of three-dimensional digital design data in support of site operation are stimulated by the global positioning system and the many uses of lasers. Surveying has always performed critical functions on construction sites, such as marking building layouts, anchor bolts, concrete formwork, or bridge bearings. The objective of spatial integration in construction is to digitally merge spatial design data with the digital model of equipment working on implementing the design. This paper will briefly review historical advancements in “perfecting” the surveying technology before presenting three examples of a quantum leap in the way we design, plan, and control construction projects in the future.
Single Image Depth Estimation Trained via Depth From Defocus Cues (2019)

Estimating depth from a single RGB images is a fundamental task in computer vision, which is most directly solved using supervised deep learning. In the field of unsupervised learning of depth from a single RGB image, depth is not given explicitly. Existing work in the field receives either a stereo pair, a monocular video, or multiple views, and, using losses that are based on structure-from-motion, trains a depth estimation network. In this work, we rely, instead of different views, on depth from focus cues. Learning is based on a novel Point Spread Function convolutional layer, which applies location specific kernels that arise from the Circle-Of-Confusion in each image location. We evaluate our method on data derived from five common datasets for depth estimation and lightfield images, and present results that are on par with supervised methods on KITTI and Make3D datasets and outperform unsupervised learning approaches. Since the phenomenon of depth from defocus is not dataset specific, we hypothesize that learning based on it would overfit less to the specific content in each dataset. Our experiments show that this is indeed the case, and an estimator learned on one dataset using our method provides better results on other datasets, than the directly supervised methods.
Characterization of molecular branching (1975)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCharacterization of molecular branchingMilan RandicCite this: J. Am. Chem. Soc. 1975, 97, 23, 6609–6615Publication Date (Print):November 1, 1975Publication History Published online1 May 2002Published inissue 1 November 1975https://pubs.acs.org/doi/10.1021/ja00856a001https://doi.org/10.1021/ja00856a001research-articleACS PublicationsRequest reuse permissionsArticle Views2766Altmetric-Citations2514LEARN 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
STRUCTURAL STUDIES OF A LIQUID-FLUIDIZED MAGNETICALLY STABILIZED BED (1988)

As part of an effort to apply the magnetically stabilized fluidized bed (MSFB) to bioseparations, we have carried out a number of studies aimed at understanding its structure and properties. These included liquid-phase dispersion, conductivity (a measure of particle-particle contact), and studies with two different orientations of the applied magnetic field (parallel and transverse to the direction of liquid flow). The dispersion studies showed that the MSFB behaves much like a packed bed and is very different from an ordinary fluidized bed. The direction in which the magnetic field is applied is quite important, in one case causing a contraction and in the other an expansion of the bed compared to the height of a bed which is fluidized under identical conditions without a field.
A solution equivalent of the 2Zn→4Zn transformation of insulin in the crystal (1984)

Circular dichroic spectroscopy clearly reveals a solvent-induced conformational change of insulin in the presence of zinc ions. The spectral change corresponds to an increase in helix content. The transition observed in solution is an equivalent of the 2Zn----4Zn insulin transformation in the crystal. This is inferred from a series of observations. (1) The spectral effects are compatible with the refolding of the B-chain N-terminus into a helix known from crystal studies. (2) The spectral effects are induced by the very same conditions which are known to induce the 2Zn----4Zn insulin transformation in the crystal (i.e. threshold concentrations of NaCl, KSCN, NaI, for example). (3) They fail to be induced by the same conditions that fail to induce the crystal transformation (e.g. Ni2+ instead of Zn2+). It is concluded that the potential to undergo the transition resides in the hexamer since neither insulin dimers nor monomeric des-pentapeptideB26-30-insulin respond detectably to high halide concentration. Secondly the ability of zinc ions to accommodate tetrahedral coordination allows the transition which is not permitted by other divalent metal ions. Thirdly the transition is independent of the off-axial tetrahedral zinc coordination sites since it occurs in [AlaB5]insulin which lacks the B5 histidine necessary for their formation. A symmetrically rearranged hexamer thus appears possible with two tetrahedrally coordinated zinc ions on the threefold axis; this is consistent with the observation that in native insulin two zinc ions per hexamer are sufficient to produce the full spectral effect. The amount of additional helix derived from the circular dichroic spectral change, however, cannot settle whether the transition comprises only three or all six of the subunits to yield a symmetrical hexamer. Finally the transformation in solution evidently still occurs in an intramolecularly A1-B29-cross-linked insulin in spite of the partially reduced flexibility.
Nonrandom Transduction of Recombinant Adeno-Associated Virus Vectors in Mouse Hepatocytes In Vivo: Cell Cycling Does Not Influence Hepatocyte Transduction (2000)

Recombinant adeno-associated virus vectors (rAAV) show promise in preclinical trials for the treatment of genetic diseases including hemophilia. Liver-directed gene transfer results in a slow rise in transgene expression, reaching steady-state levels over a period of 5 weeks concomitant with the conversion of the single-stranded rAAV molecules into high-molecular-weight concatemers in about 5% of hepatocytes. Immunohistochemistry and RNA in situ hybridization show that the transgene product is made in about approximately 5% of hepatocytes, suggesting that most rAAV-mediated gene expression occurs in hepatocytes containing the double-stranded concatemers. In this study, the mechanism(s) involved in stable transduction in vivo was evaluated. While only approximately 5% of hepatocytes are stably transduced, in situ hybridization experiments demonstrated that the vast majority of the hepatocytes take up AAV-DNA genomes after portal vein infusion of the vector. Two different vectors were infused together or staggered by 1, 3, or 5 weeks, and two-color fluorescent in situ hybridization and molecular analyses were performed 5 weeks after the infusion of the second vector. These experiments revealed that a small but changing subpopulation of hepatocytes were permissive to stable transduction. Furthermore, in animals that received a single infusion of two vectors, about one-third of the transduced cells contained heteroconcatemers, suggesting that dimer formation was a critical event in the process of concatemer formation. To determine if the progression through the cell cycle was important for rAAV transduction, animals were continuously infused with 5'-bromo-2'-deoxyuridine (BrdU), starting at the time of administration of a rAAV vector that expressed cytoplasmic beta-galactosidase. Colabeling for beta-galactosidase and BrdU revealed that there was no preference for transduction of cycling cells. This was further confirmed by demonstrating no increase in rAAV transduction efficiencies in animals whose livers were induced to cycle at the time of or after vector administration. Taken together, our studies suggest that while virtually all hepatocytes take up vector, unknown cellular factors are required for stable transduction, and that dimer formation is a critical event in the transduction pathway. These studies have important implications for understanding the mechanism of integration and may be useful for improving liver gene transfer in vivo.
Production of biologically active fragments of parathyroid hormone by isolated Kupffer cells. (1986)

Cleavage of parathyroid hormone (PTH) by isolated Kupffer cells from rat liver was examined. Iodinated PTH labeled at position 43 was converted into two radioactive fragments which were shown by Edman degradation to have residues 35 and 38 as their NH2 termini. Cleavage at these positions is characteristic of cathepsin D. Amino-terminal fragments were detected by bioassay of fractions obtained by high performance liquid chromatography. These fragments eluted in positions characteristic of the 1-34 and 1-37 peptides also previously shown to be produced by purified cathepsin D. The putative 1-37 fragment was rapidly converted to 1-34 upon digestion with cathepsin D, whereas the putative 1-34 fragment was not further digested by this enzyme, behavior previously shown to be characteristic of 1-37 and 1-34 bovine PTH. Fragmentation of PTH as measured by generation of fragments soluble in trichloroacetic acid was inhibited by methylamine, monensin, and ammonium chloride. In addition, monensin significantly inhibited production of both carboxyl- and amino-terminal fragments. Finally, active PTH fragments were also produced by elicited peritoneal macrophages. It is concluded that Kupffer cells, and other macrophages, can produce active fragments of PTH which appear in the medium. These fragments may be generated by cathepsin D within the cells.
Real-Time Embedded Control System for VTOL Aircrafts: Application to stabilize a quad-rotor helicopter (2006)

In this paper, we present the design of an autopilot embedded control system for VTOL aircrafts using low cost sensors. The embedded control system uses parallel processing architecture. In addition, multitasking software is used to implement the data acquisition, control law computation, and correction output to get the desired set point. The control law can be easily tuning to improve the performance of the vehicle. We evaluate the performance of this platform in a quad-rotor helicopter. The main goal is to achieve the stationary flight using two control strategies, a linear PD control and nonlinear nested saturations control. Real time experiments show that the autopilot is a platform relievable with low cost components.
Coat Protein-Related Polypeptides from<i>in Vitro</i>Tobacco Mosaic Virus Coat Protein Mutants Do Not Accumulate in the Chloroplasts of Directly Inoculated Leaves (1991)

The data suggest that the altered coat protein wich was on the outside of the chloroplasts caused the degradation of the chloroplasts in infected cells. Coat protein probably subverts the chloroplasts by interfering with chloroplast protein synthesis and transport in the cytoplasm
Detection of Polyomavirus BK Reactivation After Renal Transplantation Using an Intensive Decoy Cell Surveillance Program Is Cost-Effective (2011)

Clinically significant BKV reactivation occurs early after transplantation and can be reliably detected by decoy cell screening. A surveillance strategy for detecting BKV reactivation based on urine cytology is cost-effective.
X-ray photoelectron spectroscopy characterization of the oxidation and reduction of polycrystalline ZrPt3 and HfIr3 from 300 to 1700 K (1992)

Samples of the Engel–Brewer intermetallic compounds ZrPt3 and HfIr3 are characterized by x-ray photoelectron spectroscopy (XPS) after in vacuo exposure to oxygen, water vapor, and hydrogen at temperatures ranging from 300 to 1700 K. Results from these experiments indicate that both ZrPt3 and HfIr3 only partially react with oxygen and water vapor up to 1700 K, forming a surface oxide layer no thicker than approximately 35 Å. The surface nature of the oxide layer is confirmed by angle-resolved XPS studies on HfIr3. Vacuum annealing and hydrogen dosing prior to oxidation passivate the surface, inhibiting oxidation, while hydrogen exposure after oxidation reduces the surface oxide. Consequently, as a result of their stability in a high-temperature oxidizing environment, these materials show promise for use as oxidation-resistant coatings for high-temperature carbon–carbon composite applications.
Finite Element Analysis of Axi-Symmetric Solids (1965)

The finite element method has been demonstrated to provide an effective means for the analysis of two-dimensional elastic continua. In this paper, the method is applied to a special class of two-dimensional system: The axially symmetric elastic solid. The procedure is identical with that used in plane stress analysis; it is merely necessary to develop special stiffness matrices for the axi-symmetric finite element. In the present development, axi-symmetric elements of triangular cross section are considered (forming complete rings in plan view). The procedure for evaluating the element stiffness is summarized, and the modifications required to adapt a finite element plane stress digital computer program for the treatment of axi-symmetric systems are cited. Results of several example analyses are presented; the solution of the Boussinesq problem, a concentrated load applied to an elastic half-space, demonstrates the accuracy of results that may be obtained.
Marked suppression of secondary hyperparathyroidism by intravenous administration of 1,25-dihydroxy-cholecalciferol in uremic patients. (1984)

Current evidence suggests that administration of 1,25(OH)2D3 to patients with chronic renal insufficiency results in suppression of secondary hyperparathyroidism only if hypercalcemia occurs. However, since the parathyroid glands possess specific receptors for 1,25(OH)2D3 and a calcium binding protein, there is considerable interest in a possible direct effect of 1,25(OH)2D3 on parathyroid hormone (PTH) secretion independent of changes in serum calcium. Recent findings indicate substantial degradation of 1,25(OH)2D3 in the intestine, therefore, it is possible that while oral administration of the vitamin D metabolite increases intestinal calcium absorption, the delivery of 1,25(OH)2D3 to peripheral target organs may be limited. We therefore compared the effects of orally or intravenously administered 1,25(OH)2D3 on the plasma levels of 1,25(OH)2D3 and the effects of these two modes of treatment on PTH secretion. Whereas oral administration of 1,25(OH)2D3 in doses adequate to maintain serum calcium at the upper limits of normal did not alter PTH levels, a marked suppression (70.1 +/- 3.2%) of PTH levels was seen in all 20 patients given intravenous 1,25(OH)2D3. Temporal studies suggested a 20.1 +/- 5.2% decrease in PTH without a significant change in serum calcium with intravenous 1,25(OH)2D3. In five patients the serum calcium was increased by the oral administration of calcium carbonate, the decrement in serum i-PTH was only 25 +/- 6.65% when compared with 73.5 +/- 5.08% (P less than 0.001) obtained by the administration of intravenous 1,25(OH)2D3. Thus, a similar serum calcium achieved by intravenous 1,25(OH)2D3 rather than calcium carbonate has a greater suppressive effect in the release of PTH. These studies indicate that 1,25(OH)2D3 administered intravenously rather than orally may result in a greater delivery of the vitamin D metabolite to peripheral target tissues other than the intestine and allow a greater expression of biological effects of 1,25(OH)2D3 in peripheral tissues. The use of intravenous 1,25(OH)2D3 thus provides a simple and extremely effective way to suppress secondary hyperparathyroidism in dialysis patients.
Targeted cytotoxic luteinizing hormone releasing hormone (LH-RH) analogs inhibit growth of estrogen independent MXT mouse mammary cancers in vivo by decreasing cell proliferation and inducing apoptosis (1997)

Tumor inhibitory action and the optimal dosage regimens of highly potent targeted cytotoxic luteinizing hormone releasing hormone (LH-RH) analogs containing doxorubicin (DOX) or 2-pyrrolino-DOX (AN-201) were tested in female BDF mice bearing estrogen independent MXT mouse mammary cancers. The effects were compared to those obtained with the cytotoxic radicals DOX or AN-201 alone. Analog AN-207, formed by linking 2-pyrrolino-DOX to [D-Lys6]LH-RH, and analog AN-152, produced by conjugation of DOX to the same carrier, given i.p. as a single injection or repeatedly 2 days apart at their maximum tolerated doses (MTDs) resulted in a 89-93% inhibition of tumor growth. Equimolar amounts of the cytotoxic radicals were toxic. AN-207 and AN-152 likewise had stronger tumor inhibitory effects than their respective cytotoxic radicals AN-201 or DOX alone, when compared at the lower doses corresponding to MTDs of the radicals. Histological evaluation indicated that decreased cell proliferation (shown by mitotic index and AgNOR counts) as well as increased apoptosis (demonstrated by histological and biochemical methods) both contributed to tumor suppression caused by the cytotoxic hormone analogs. Specific, high-affinity LH-RH receptors were present on MXT tumor samples of control untreated mice, but no binding sites for LH-RH could be found on tumor membranes after treatment with the cytotoxic LH-RH analogs. The results suggest that these powerful targeted cytotoxic LH-RH analogs could be considered for treatment of human mammary cancers having receptors for LH-RH.
Mass Spectrometric Characterisation of Post-Translational Modification and Genetic Variation in Human Tetranectin (1999)

Tetranectin, a plasminogen-binding trimeric C-type lectin-like protein primarily involved in tissue remodeling and development, was scanned for covalent modifications and sequence heterogeneity, using a combination of mass spectrometric and classical protein chemical analytical methods. Electrospray ionisation mass spectrometry showed the presence of eight components of different mass and abundance in plasma tetranectin, all of higher mass than that calculated from the cDNA sequence. To identify and locate residues accounting for the heterogeneity, samples of tetranectin were subjected to proteolytic cleavage. Peptide fragments, in mixtures or in purified form, were analysed by matrix-assisted-laser-desorption-ionisation mass spectrometry and, where required, by Edman sequencing and compared to the cDNA sequence. Our results show that the mass heterogeneity in plasma tetranectin is due to sequence heterogeneity at position 85 and the presence of a partially sialylated oligosaccharide prosthetic group attached to Thr-4. Residue 85 is encoded in the cDNA as a Ser residue, but plasma tetranectin is a 1:1 mixture of Ser85 and Gly-85 sequence variants. Mass spectrometric analysis of enzymatic and mild acid hydrolysates of an N-terminal glycopeptide showed that the composition and partial covalent structure of the O-linked oligosaccharide prosthetic group is < or =N-acetylhexosamine < or =[hexose, (sialic acid)0-3].