gebhart/patrepeval huggingface dataset:
Mechanisms of Stability of Fibers Electrospun from Peptides with Ionized Side Chains (2012)

Abstract Non‐woven electrospun fiber mats made of polypeptides are increasingly considered attractive for basic research and technology development in the life sciences, medicine, and other areas. Here, co ‐poly( L ‐glutamic acid 4 , L ‐tyrosine 1 ) (PLEY) was adopted as a model polymer for a study of the mechanisms of fiber stability. Crosslink density has been quantified by a dye‐based method. Fiber morphology, elemental composition, and stability have been assessed by microscopy and energy‐dispersive X‐ray spectroscopy (EDX). The results have been interpreted with reference to the pH dependence of the UV absorbance and fluorescence of PLEY chains. The study has revealed that fiber stability in an aqueous medium is crucially dependent on the extent of side chain ionization, even after polymer crosslinking. magnified image Covalent crosslinks (orange) may be formed between polymers (blue).
Lymphotoxin enhances the susceptibility of neoplastic and preneoplastic cells to natural killer cell mediated destruction (1982)

Treatment of neoplastic guinea-pig cells for 1-14 days with 300 units of guinea-pig lymphotoxin/ml medium enhanced 2- to 5-fold their susceptibility to natural killer (NK) cell-mediated cytotoxicity as measured by 4 h 51Cr and 72 h [3H]-thymidine-release assays. The NK susceptibility of human neoplastic and guinea-pig non-neoplastic cells refractory to guinea-pig lymphotoxin growth-inhibitory activity was unchanged after lymphotoxin treatment. Lymphotoxin preparations were free of detectable interferon and the enhancing activity copurified with lymphotoxin during diafiltration and isoelectric focusing. Treatment of NK cells with lymphotoxin preparations also augmented NK-mediated lysis but that activity did not copurify with lymphotoxin. As with neoplastic cells, lymphotoxin-sensitive preneoplastic cells previously treated with ultraviolet light, a chemical carcinogen, or carcinogen and the tumor-promoting agent tetradecanoylphorbol-acetate also exhibited lymphotoxin enhancement to NK-cell destruction. Thus, the immunologic hormone lymphotoxin enhances the susceptibility of lymphotoxin-sensitive cells to NK-cell destruction, indicating that these two natural immune mediators, lymphotoxin and NK cells, have the potential in concert to regulate carcinogenesis and neoplastic growth.
Fully automatic 3D segmentation of iceball for image-guided cryoablation (2012)

The efficient extraction of the cryoablation iceball from a time series of 3D images is crucial during cryoablation to assist the interventionalist in determining the coverage of the tumor by the ablated volume. Conventional semi-automatic segmentation tools such as ITK-SNAP and 3D Slicer's Fast Marching Segmentation can attain accurate iceball segmentation in retrospective studies, however, they are not ideal for intraprocedure real time segmentation, as they require time-consuming manual operations, such as the input of fiducials and the extent of the segmented region growth. In this paper, we present an innovative approach for the segmentation of the iceball during cryoablation, that executes a fully automatic computation. Our approach is based on the graph cuts segmentation framework, and incorporates prior information of iceball shape evolving in time, modeled using experimentally-derived iceball growth parameters. Modeling yields a shape prior mask image at each timepoint of the imaging time series for use in the segmentation. Segmentation results of our method and the ITK-SNAP method are compared for 8 timepoints in 2 cases. The results indicate that our fully automatic approach is accurate, robust and highly efficient compared to manual and semi-automatic approaches.
Formation of ferrite thin films by vacuum evaporation with annealing process (1977)

Cobalt ferrite thin films were prepared in successive processes by vacuum evaporation of cobalt on hematite (αFe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ) films and annealing at relatively low temperature. The surfaces of these films were observed by transmission electron micrograph(TEM) and scanning electron micrograph(SEM), also their structures were identified using transmission electron diffraction(TED) and reflection electron diffraction(RED) methods. Then, a diffusion profile of depth distribution of cobalt ions into (αFe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ) layer was investigated by Auger electron spectroscopy(AES) analysis. Magnetic properties were measured with a vibrating sample magnetometer. Results showed that cobalt ions migrated easily into a (αFe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ) layer at relatively low temperature and formed ferrite thin films in the form of Co <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3-x</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> . Their magnetic properties, such as high coercive force, large residual magnetization and smooth surface, indicate considerable possibilities to obtain excellent magnetic medium for high density recording disk.
Activity-Based Protein Profiling of Organophosphorus and Thiocarbamate Pesticides Reveals Multiple Serine Hydrolase Targets in Mouse Brain (2010)

Organophosphorus (OP) and thiocarbamate (TC) agrochemicals are used worldwide as insecticides, herbicides, and fungicides, but their safety assessment in terms of potential off-targets remains incomplete. In this study, a chemoproteomic platform, termed activity-based protein profiling, was used to broadly define serine hydrolase targets in mouse brain of a panel of 29 OP and TC pesticides. Among the secondary targets identified, enzymes involved in the degradation of endocannabinoid signaling lipids, monoacylglycerol lipase, and fatty acid amide hydrolase were inhibited by several OP and TC pesticides. Blockade of these two enzymes led to elevations in brain endocannabinoid levels and dysregulated brain arachidonate metabolism. Other secondary targets include enzymes thought to also play important roles in the nervous system and unannotated proteins. This study reveals a multitude of secondary targets for OP and TC pesticides and underscores the utility of chemoproteomic platforms in gaining insights into biochemical pathways that are perturbed by these toxicants.
Dental Follicle Progenitor Cell Heterogeneity in the Developing Mouse Periodontium (2006)

As a developmental precursor for diverse periodontal tissues, the dental follicle (DF) harbors great promise for periodontal tissue regeneration. However, development of optimal therapy awaits the answer to a key question that impinges on many issues in development-Do adult progenitor tissues form a homogeneous cell population that differentiates into target tissues when they arrive at the site, or they contain heterogeneous cell populations that are committed to specific fates? To address the homogeneity/heterogeneity question, we analyzed differentiation pathways and markers in several cloned DF cell lines. Our studies revealed that each of our cloned DF lines featured remarkably unique characteristics, indicative of a separate and distinct lineage. One line, DF1, was high in proliferative activity but did not display any mineralization behavior, suggesting that it might be related to a periodontal ligament-type lineage. DF2 was similar to DF1, but featured remarkably high alkaline phosphatase activity indicative of a highly undifferentiated state. DF3 matched the mineralization characteristics of a same stage alveolar bone line AB1 in terms of gene expression and von Kossa staining, indicating that DF3 might be of cementoblastic or alveolar bone osteoblastic lineage. To verify the multilineage potential of the DF for purposes of tissue engineering, a series of differentiation induction experiments was conducted. For identification purposes, characteristics of these heterogeneous follicular progenitor cells were compared with follicle components in tissue sections of the postnatal developing periodontium. The presence of heterogeneous cell populations in the DF mirrors individual developmental pathways in the formation of the dental integument. The profound cellular heterogeneity of the DF as an adult progenitor for tissue regeneration also suggests that heterogeneous cellular constituents might play as much of a role in tissue regeneration as the inducible characteristics of individual lineages might do.
Visualizing Zeptomole (Electro)Catalysis at Single Nanoparticles within an Ensemble (2011)

The relationship between the structural properties, such as the size and the shape, of a catalytic nanoparticle and its reactivity is a key concept in (electro)catalysis. Current understanding of this relationship is mainly derived from studies involving large ensembles of nanoparticles (NPs). However, the results necessarily reflect the average catalytic behavior of an ensemble, even though the properties of individual particles may vary widely. Here, we demonstrate a novel approach using scanning electrochemical cell microscopy (SECCM) to locate and map the reactivity of individual NPs within an electrocatalytic ensemble, consisting of platinum NPs supported on a single carbon nanotube. Significantly, our studies show that subtle variations in the morphology of NPs lead to dramatic changes in (potential-dependent) reactivity, which has important implications for the design and assessment of NP catalysts. The instrumental approach described is general and opens up new avenues of research in functional imaging, nanoscale electron transfer, and catalysis.
Extreme thermodynamics with polymer gel tori: Harnessing thermodynamic instabilities to induce large-scale deformations (2018)

When a swollen, thermoresponsive polymer gel is heated in a solvent bath, it expels solvent and deswells. When this heating is slow, deswelling proceeds homogeneously, as observed in a toroid-shaped gel that changes volume while maintaining its toroidal shape. By contrast, if the gel is heated quickly, an impermeable layer of collapsed polymer forms and traps solvent within the gel, arresting the volume change. The ensuing evolution of the gel then happens at fixed volume, leading to phase separation and the development of inhomogeneous stress that deforms the toroidal shape. We observe that this stress can cause the torus to buckle out of the plane, via a mechanism analogous to the bending of bimetallic strips upon heating. Our results demonstrate that thermodynamic instabilities, i.e., phase transitions, can be used to actuate mechanical deformation in an extreme thermodynamics of materials.
Airborne adaptive MTI scheme with preventing the whitening of the target (1999)

A new airborne MTI scheme that applies to non-homogeneous clutter environment is presented. Results of simulation have proved that the scheme has a superior ground clutter suppression performance and can effectively prevent the whitening of a target.
Practical high efficiency bifacial solar cells (2002)

In this paper, we present a practical process to obtain bifacial Si solar cells. These cells are made using p/sup +/nn/sup +/ structure on high-medium base resistivity, continuous emitters and with a process that maintains high bulk minority carrier lifetime. Efficiencies of 19.1% and 18.1% are achieved under standard conditions when the cell is illuminated by n/sup +/n high-low junction and when it is illuminated by p/sup +/n junction, respectively. We show that the n/sup +/n high-low junction provides a higher current density and a good ratio between generated current of each face is found to be of about 103%.
Powder pattern indexing with the dichotomy method (2004)

The efficiency of the successive dichotomy method for powder diffraction pattern indexing [Louër & Louër (1972). J. Appl. Cryst . 5 , 271–275] has been proved over more than 30 years of usage. Features implemented in the new version of the computer program DICVOL 04 include (i) a tolerance to the presence of impurity (or inaccurately measured) diffraction lines, (ii) a refinement of the `zero-point' position, (iii) a reviewing of all input lines from the solution found from, generally, the first 20 lines, (iv) a cell analysis, based on the concept of the reduced cell, to identify equivalent monoclinic and triclinic solutions, and (v) an optional analysis of input powder data to detect the presence of a significant `zero-point' offset. New search strategies have also been introduced, e.g. each crystal system is scanned separately, within the input volume limits, to limit the risk of missing a solution characterized by a metric lattice singularity. The default values in the input file have been extended to 25 Å for the linear parameters and 2500 Å 3 for the cell volume. The search is carried out exhaustively within the input parameter limits and the absolute error on peak position measurements. Many tests with data from the literature and from powder data of pharmaceutical materials, collected with the capillary technique and laboratory monochromatic X-rays, have been performed with a high success rate, covering all crystal symmetries from cubic to triclinic. Some examples reported as `difficult' cases are also discussed. Additionally, a few recommendations for the correct practice of powder pattern indexing are reported.
<i>E. coli</i> Ada regulatory protein repairs the <i>S</i>p diastereoisomer of alkylated DNA (1985)

Using HPLC and 31P NMR spectroscopy on a chemically synthesized asymmetric mixture of the diastereoisomers of thymidyl(3'----5')thymidyl-O-methyl phosphate absolute configuration has been correlated with chromatographic mobility. The methyl phosphotriester system in alkylated DNA which is repaired by the Ada regulatory protein of E. coli has consequently been established to possess the Sp configuration.
Mild Detritylation of Nucleic Acid Hydroxyl Groups by Warming Up (2011)

It is challenging to effectively deprotect hydroxyl groups of acid-or-base sensitive bio-macromolecules without causing even minor defects and compromising high quality of final products. We report here a mild detritylation strategy in mildly acidic buffers to remove the DMTr protection from the 5'-hydroxyl groups of synthetic nucleic acids. The DMTr-groups can be easily and effectively removed at pH 4.5 or 5.0 with slight warming up (40 °C), offering virtually quantitative deprotection. This warming-up strategy is particularly useful for deprotection of the modified nucleic acids that are sensitive to the conventional acid deprotection. As a first step towards our long-term goal of synthesizing defect-free nucleic acids, our novel and simple strategy further increases the quality of synthetic nucleic acids.
Evidence of Absence of Porcine Endogenous Retrovirus (PERV) Infection in Patients Treated with a Bioartificial Liver Support System (1999)

Porcine endogenous retrovirus (PERV) genomes are present in all pig cells. In this retrospective study, we assessed PERV infectivity in 28 patients treated with an extracorporeal bioartificial liver (HepatAssist system) that includes a membrane device containing porcine hepatocytes. All patients tested negative for PERV using polymerase chain reaction analysis of peripheral blood mononuclear cells (PBMC) collected up to 5 years after treatment. In vitro results showed that the membrane decreased the risk of PERV transmission by a factor of 105, and porcine hepatocytes did not produce infectious PERV in co-cultures with human cell line 293. Our results do not support the presence of PERV infection in patients treated with this porcine hepatocyte-based bioartificial liver.
Basic fibroblast growth factor gene transfection to enhance the repair of avascular necrosis of the femoral head. (2004)

Transfection of bFGF gene enhances bone tissue angiogenesis. Repair in osteonecrosis would be accelerated accordingly.
Overview of the efficacy of cetuximab in recurrent and/or metastatic squamous cell carcinoma of the head and neck in patients who previously failed platinum‐based therapies (2008)

Cetuximab has the potential to prolong survival in patients with recurrent and/or metastatic SCCHN who fail on platinum therapy compared with various second-line therapies. Cetuximab did not increase the toxicities associated with chemotherapy. The results obtained by treatment with cetuximab alone after platinum failure did not appear to differ from the results obtained by reintroducing platinum in combination with cetuximab.
Characteristics of cytotoxin produced by Campylobacter jejuni strains. (1994)

The cytotoxic activity against cultured cells of nineteen clinically isolated strains of Campylobacter jejuni was tested. These strains were found to have different profiles in cytotoxin and enterotoxin production, and the characteristics of cytotoxin were further investigated. The cytotoxin showed cell killing toxicity against CHO and HeLa cells. Vacuole formation was observed in the case of rat hepatocyte primary culture. Treatment with trypsin at 80 degrees C for 30 min inactivated the cytotoxin activity, suggesting that the toxin was protein. The toxin was produced in the culture supernatant with high specific activity per protein, followed by polymyxin and CHAPS treatment fractions in this order. This suggests that the cytotoxin was a cell-releasing toxin and that the active toxin was present as a membrane-associated form. The cytotoxin activity was separated from the enterotoxin activity by DEAE-cellulose column chromatography. The washed fraction contained enterotoxin and cytotoxin, whereas the KCl eluted fraction showed mainly cytotoxic activity.
Oxidative stress aspects of the cytotoxicity of carbamide peroxide: in vitro studies (1995)

Carbamide peroxide is the active ingredient in many at-home patient-applied tooth whiteners. The cytotoxicity of carbamide peroxide, as related to oxidative stress, was evaluated in vitro with several human cell lines, including Smulow-Glickman (S-G) gingival epithelial cells. The potency of carbamide peroxide was related to its hydrogen peroxide component rather than to carbamide, was eliminated in the presence of exogenous catalase, and was enhanced in the presence of aminotriazole, an inhibitor of cellular catalase. The intracellular level of glutathione, a scavanger of toxic oxygen metabolites, was decreased in cells exposed to carbamide peroxide; at higher concentrations of carbamide peroxide, leakage of lactic acid dehydrogenase was also evident. Cells pretreated with the glutathione-depleting agents, buthionine sulfoximine, chlorodinitrobenzene, and bis(chloroethyl) nitrosourea, were hypersensitive to subsequent challenge with carbamide peroxide. Conversely, pretreatment with the iron chelator, deferoxamine, protected the cells against subsequent exposure to carbamide peroxide.
Extent of the acute phase response in fulminant hepatic failure. (1994)

The extent of the acute phase response and the relation between acute phase proteins and cytokines in plasma was investigated in 50 patients with fulminant hepatic failure. On admission, C reactive protein was significantly higher in fulminant hepatic failure (median: 12.4 micrograms/ml, range:0.2-112 micrograms/ml) than in 20 controls (median: 0.8 microgram/ml, range: 0.3-2.9 micrograms/ml, p < 0.001). Serial measurements showed that plasma C reactive protein increased daily after admission until day 5, the end of the study period. alpha 1-Antitrypsin (AAT) (median: 69.1%, range: 27.5-124%) and fibrinogen (median: 1.10 g/l, range: 0-2.82 g/l) were significantly lower in fulminant hepatic failure on admission than in controls (AAT: median: 126%, range: 75.4-149%; fibrinogen: median 2.48 g/l, range: 1.82-3.39 g/l, p < 0.001) and did not change subsequently. Both AAT and fibrinogen were maintained at significantly higher concentrations in survivors than in those who did not. Bacterial infection occurred in 23 patients during the course of fulminant hepatic failure, but did not influence the concentrations of these three proteins. Interleukin 6 was significantly higher in fulminant hepatic failure (median: 21.2 pg/ml, range: 0-871 pg/ml) than in controls (median: 2.4 pg/ml, range: 1.5-8.2 pg/ml, p < 0.001). There was a significant correlation between interleukin 6 and the C reactive protein concentrations in patients with viral hepatitis on admission and in all patients 48 hours later, consistent with other evidence that interleukin 6 stimulates synthesis of this acute phase protein.
Thermosonic Gold Wire Bonding to Copper Conductors (1982)

The use of thick film copper conductors in hybrid microcircuitry requires that wire bonding to their surfaces be demonstrated as a feasible and reliable interconnection technique. Previous work has shown that acceptable and reliable ultrasonic aluminum wire bonds can be made to copper. The conditions necessary to make successful thermosonic gold wire bonds to copper are described. Items covered are the types of tool to use, the influence of stage temperature, the maximum dwell time for the parts on the stage, and the bonding window that yields the best results. In addition, information is provided on the reliability of the bonds following aging at temperatures in the range 150° to 350°C, in high temperature-humidity conditions such as 40°C, 90 percent RH, and 85°C, 85 percent RH and after 100 thermal cycles between -55°C and 150°C.
On two new polymers of acetaldehyde (1936)

M. W. Travers, Trans. Faraday Soc., 1936, 32, 246 DOI: 10.1039/TF9363200246
Altered error specificity of RNase H-deficient HIV-1 reverse transcriptases during DNA-dependent DNA synthesis (2013)

Asp(443) and Glu(478) are essential active site residues in the RNase H domain of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT). We have investigated the effects of substituting Asn for Asp(443) or Gln for Glu(478) on the fidelity of DNA-dependent DNA synthesis of phylogenetically diverse HIV-1 RTs. In M13mp2 lacZα-based forward mutation assays, HIV-1 group M (BH10) and group O RTs bearing substitutions D443N, E478Q, V75I/D443N or V75I/E478Q showed 2.0- to 6.6-fold increased accuracy in comparison with the corresponding wild-type enzymes. This was a consequence of their lower base substitution error rates. One-nucleotide deletions and insertions represented between 30 and 68% of all errors identified in the mutational spectra of RNase H-deficient HIV-1 group O RTs. In comparison with the wild-type RT, these enzymes showed higher frameshift error rates and higher dissociation rate constants (koff) for DNA/DNA template-primers. The effects on frameshift fidelity were similar to those reported for mutation E89G and suggest that in HIV-1 group O RT, RNase H inactivation could affect template/primer slippage. Our results support a role for the RNase H domain during plus-strand DNA polymerization and suggest that mutations affecting RNase H function could also contribute to retrovirus variability during the later steps of reverse transcription.