gebhart/patrepeval huggingface dataset:
Analysis of hydroxy fatty acids as pentafluorobenzyl ester, trimethylsilyl ether derivatives by electron ionization gas chromatography/mass spectrometry (1995)

Electron ionization (EI) gas chromatography/mass spectrometry (GC/MS) analysis of pentafluorobenzyl ester-trimethyl sllyl ether (PFB-TMS) derivatives of hydroxy-subshtuted fatty acids provides structural information comparable to that obtained in analysis of methyl ester-trimethyl silyl ether (Me-TMS) derivatives. Use of this derivative eliminates the need to prepare two separate derivatives, the PFB-TMS derivative for molecular weight determination by electron capture ionization (negative ions) analysis and the Me-TMS derivative for structural determination by EI GC/MS analysis. The relative abundance of fragment ions observed during EI GC/MS analysis of these derivatized unsaturated fatty acids indicates the location of the -OTMS substituents relative to double bond positions in those cases studied. The most abundant fragment ions are observed when the compound contains an unsaturation two carbon atoms removed from the -OTMS ether carbon (the β-OTMS position). The "saddle effect" observed in the GC/MS analyses of some derivatized monohy- droxy unsaturated fatty acids is suggested to be due to a thermally allowed pericyclic double bond rearrangement and indicates the presence of a conjugated diene one carbon atom removed from the -OTMS ether carbon (the α-OTMS position). The saddle effect is most prominent for fatty acids that contain additional unsaturation separated by a single methylene unit from the conjugated diene moiety.
Cardiomyocyte DNA synthesis and binucleation during murine development (1996)

Cardiomyocyte DNA synthesis and binucleation indexes were determined during murine development. Cardiomyocyte DNA synthesis occurred in two temporally distinct phases. The first phase occurred during fetal life and was associated exclusively with cardiomyocyte proliferation. The second phase occurred during early neonatal life and was associated with binucleation. Collectively, these results suggest that cardiomyocyte reduplication ceases during late fetal life. Northern and Western blot analyses identified several candidate genes that were differentially expressed during the reduplicative and binucleation phases of cardiomyocyte growth.
A hyper-redundant manipulator (1994)

"Hyper-redundant" manipulators have a very large number of actuatable degrees of freedom. The benefits of hyper-redundant robots include the ability to avoid obstacles, increased robustness with respect to mechanical failure, and the ability to perform new forms of robot locomotion and grasping. The authors examine hyper-redundant manipulator design criteria and the physical implementation of one particular design: a variable geometry truss.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Deletion of the propeptide of apolipoprotein A-I reduces protein expression but stimulates effective conversion of preβ-high density lipoprotein to α-high density lipoprotein (2000)

The properties of the mature and pro-forms of recombinant apolipoprotein A-I (apoA-I) were compared with those of apoA-I isolated from human plasma. When the synthesis and secretion of pro- and mature forms of apoA-I from a baculovirus/insect cell expression system were compared in parallel experiments, the amount of the pro-form of apoA-I synthesized and secreted was severalfold higher than that of the mature form of apoA-I. A comparison of the properties of the pro- and mature forms of recombinant apoA-I and human plasma apoA-I showed no difference between all three in their secondary structure, their ability to self-associate, lipid-binding capacity, lecithin: cholesterol acyltransferase activation, and binding to the phospholipid transfer protein. The properties of reconstituted high density lipoprotein (HDL) particles formed from the proteins and their ability to promote cholesterol and phospholipid efflux from human skin fibroblasts were also similar. However, their ability to bind to plasma HDL subfractions differed, because twice as much proapoA-I associated with prebeta(1)-HDL and prebeta(2)-HDL subfractions compared with both mature recombinant and plasma apoA-I. Correspondingly, the amount of proapoA-I in alpha-HDL subfractions, especially in alpha(1)-HDL and alpha(2)-HDL, was decreased. We conclude that while the propeptide of apoA-I is required for the effective synthesis and secretion of apoA-I, cleavage of this peptide is a requisite for the effective interconversion of HDL subfractions.
Transport of sugar nucleotides into rat liver Golgi. A new Golgi marker activity. (1982)

Following incubation of sealed, "right side out," rat liver Golgi-derived vesicles with a mixture of [3H]GDP-fucose and GDP-[14C]fucose, the difference in the 3H to 14C ratio between the incubation medium and the lumen of the vesicles was less than 11%, suggesting that the sugar nucleotide was transported intact into the vesicles. Transport of GDP-fucose weas temperature-dependent, saturable, with an apparent Km of 7.5 microM and a Vmax of 14 pmol/mg of protein/10 min and inhibited by substrate analogues. Pretreatment of intact Golgi vesicles with pronase inhibited transport by 80% under conditions in which sialyltransferases (a lumenal marker) were not inhibited. This result is consistent with a sugar nucleotide carrier protein, portions of which face the cytoplasmic side of Golgi vesicles. Previous studies from this laboratory had shown that CMP-N-acetylneuraminic acid (CMP-NeuAc) could penetrate mouse liver microsomes in a manner suggesting carrier-mediated transport (Carey, D. J., Sommers, L. W., and Hirschberg, C. B. (1980) Cell 19, 597-605). Subsequent to transport, a portion of the N-acetylneuraminic acid moiety became covalently linked to proteins facing the lumen of Golgi vesicles (Carey, D. J., and Hirschberg, C. B. (1981) J. Biol. Chem. 256, 989-993). Upon subfractionation of rat liver into vesicles derived from the smooth and rough endoplasmic reticulum and Golgi, both the highest CMP-NeuAc specific transport activity and total transport activity were localized in the Golgi. Any transport activity in the other vesicles could be accounted for by contamination with Golgi, as determined by established marker enzyme activities. Transport of CMP-NeuAc was temperature-dependent, inhibited by pronase, substrate analogues, and saturable, with an apparent Km of 2.4 microM and a Vmax of 150 pmol/mg of protein/10 min.
New purged UV spectroscopic ellipsometer to characterize thin films and multilayers at 157 nm (2000)

Spectroscopic ellipsometry has long been recognized as the technique of choice to characterize thin films and multi layers. Instrumentation for the next generation of UV lithography at 157nm requires special optical set-up since O<SUB>2</SUB> and H<SUB>2</SUB>O are extremely absorbing below 190nm. The new system works into a purged glove box to reduce the oxygen and water contamination in the part per million range. The optical set-up includes a premonochromator in the polarizer arm to avoid photo bleaching. The system works in rotating analyzer configuration to minimize the parasitic polarizations. Ellipsometric and photometric measurement versus wavelength from 145 up to 630 nm and angle of incidence can be performed. The proposed paper will present in details the new system with some first experimental results in the field of micro lithography. Results are compared to those obtained with more standard UV ellipsometers and correlated to other measurements obtained with grazing x-ray reflectance technique.
Divergent Immune Responses in Male and Female Mice after Trauma-Hemorrhage: Dimorphic Alterations in T Lymphocyte Steroidogenic Enzyme Activities (2001)

Immune responses are suppressed in males, but not in proestrous females, after trauma-hemorrhage. Testosterone and 17beta-estradiol appear to be responsible for divergent immune effects. There is considerable evidence to suggest sex steroid hormone involvement in immune functions. As formation of active steroid depends on the activity of androgen- and estrogen-synthesizing enzymes, expression and activity of 5alpha-reductase, aromatase, and 3beta- and 17beta- hydroxysteroid dehydrogenases were determined in spleen and T lymphocytes of male and proestrous female mice after trauma-hemorrhage. All of the enzymes were present in spleen, specifically in T lymphocytes. 5alpha-Reductase expression and activity increased in male T lymphocytes, whereas aromatase activity, but not expression, increased in female T lymphocytes. Increased 5alpha-reductase activity in male T lymphocytes is immunosuppressive because of increased 5alpha-dihydrotestosterone synthesis, whereas in females increased aromatase activity triggering 17beta-estradiol synthesis is immunoprotective. This study also demonstrates the importance of 17beta-hydroxysteroid dehydrogenase oxidative and reductive functions. The immunoprotection of proestrous females is associated with enhanced reductase function of the enzyme. In males, decreased expression of oxidative isomer type IV, which impairs catabolism of 5alpha-dihydrotestosterone, probably augments immunosuppression. This study provides evidence for the involvement of intracrine sex steroid synthesis in gender dimorphic immune responses after trauma-hemorrhage.
Vision Through the Atmosphere (1952)

The present volume is the only full account in English of the physical, physiological, and psychological factors which lie at the basis of the calculation of the range of vision through the atmosphere. There is an extended chapter on instruments and one on the author's own theory of the colours of distant objects.
An Investigation into the Lability of the Bioactivity of Human Growth Hormone Using the ESTA Bioassay (1996)

We compared the bioactivity attributable to human growth hormone (hGH) in serum samples, determined at the time of their collection, with that after storage for 2-18 months at -20 degrees C. The samples were obtained from volunteers and patients who underwent provocative tests of hGH secretion, and the bioactivity was determined in the ESTA bioassay, which is based upon the use of Nb2 cells. We report that, in some subjects, the bioactivity of samples collected at the response peaks deteriorated on storage for as little as 2 months. The decrease in hGH bioactivity was systematic in that it consistently declined so as to approach the values initially determined by an immunoassay (Hybritech IRMA). This differential lability was a characteristic of the peak samples, and was not observed for either samples collected before and after the peaks of hGH secretion or for purified preparations of hGH which were subjected to a range of freeze/thaw and storage regimens. We suggest that this unusual lability is indicative of transient shifts in the spectrum of the variants of hGH which are present in the circulation following stimulation by provocative agents. This study emphasises the need to minimise the risk of introducing storage artefacts in investigations into the responses of hGH to provocation.
Non-invasive quantitative reconstruction of tissue elasticity using an iterative forward approach (2000)

A novel iterative approach is presented to estimate Young's modulus in homogeneous soft tissues using vibration sonoelastography. A low-frequency (below 100 Hz) external vibration is applied and three or more consecutive frames of B-scan image data are recorded. The internal vibrational motion of the soft tissue structures is calculated from 2D displacements between pairs of consecutive frames, which are estimated using a mesh-based speckle tracking method. An iterative forward finite element approach has been developed to reconstruct Young's modulus from the measured vibrational motion. This is accomplished by subdividing the 2D image domain into sample blocks in which Young's modulus is assumed to be constant. Because the finite element equations are internally consistent, boundary values other than displacement are not required. The sensitivity of the results to Poisson's ratio and the damping coefficient (viscosity) is investigated. The approach is verified using simulated displacement data and using data from tissue-mimicking phantoms.
Preparation and Characterization of Poly(lipid)-Coated, Fluorophore-Doped Silica Nanoparticles for Biolabeling and Cellular Imaging (2007)

The fabrication, characterization, and implementation of poly(lipid)-coated, highly luminescent silica nanoparticles as fluorescent probes for labeling of cultured cells are described. The core of the probe is a sol-gel-derived silica nanoparticle, 65-100 nm in diameter, in which up to several thousand dye molecules are encapsulated (Lian, W.; et al. Anal. Biochem. 2004, 334, 135-144). The core is coated with a membrane composed of bis-sorbylphosphatidylcholine, a synthetic polymerizable lipid that is chemically cross-linked to enhance the environmental and chemical stability of the membrane relative to a fluid lipid membrane. The poly(lipid) coating has two major functions: (i) to reduce nonspecific interactions, based on the inherently biocompatible properties of the phosphorylcholine headgroup, and (ii) to permit functionalization of the particle, by doping the coating with lipids bearing chemically reactive or bioactive headgroups. Both functions are demonstrated: (i) Nonspecific adsorption of dissolved proteins to bare silica nanoparticles and of bare nanoparticles to cultured cells is significantly reduced by application of the poly(lipid) coating. (ii) Functionalization of poly(lipid)-coated nanoparticles with a biotin-conjugated lipid creates a probe that can be used to target both dissolved protein receptors as well as receptors on the membranes of cultured cells. Measurements performed on single nanoparticles bound to planar supported lipid bilayers verify that the emission intensity of these probes is significantly greater than that of single protein molecules labeled with several fluorophores.
Subcutaneous vaccination with irradiated, cytokine-producing tumor cells stimulates CD8+ cell-mediated immunity against tumors located in the "immunologically privileged" central nervous system. (1996)

Vaccination with cytokine-producing tumor cells generates potent immune responses against tumors outside the central nervous system (CNS). The CNS, however, is a barrier to allograft and xenograft rejection, and established tumors within the CNS have failed to respond to other forms of systemic immunotherapy. To determine what barriers the "immunologically privileged" CNS would pose to cytokine-assisted tumor vaccines and what cytokines would be most efficacious against tumors within the CNS, we irradiated B16 murine melanoma cells producing murine interleukin 2 (IL-2), IL-3, IL-4, IL-6, gamma-interferon, or granulocyte-macrophage colony stimulating factor (GM-CSF) and used these cells as subcutaneous vaccines against tumors within the brain. Under conditions where untransfected B16 cells had no effect, cells producing IL-3, IL-6, or GM-CSF increased the survival of mice challenged with viable B16 cells in the brain. Vaccination with B16 cells producing IL-4 or gamma-interferon had no effect, and vaccination with B16 cells producing IL-2 decreased survival time. GM-CSF-producing vaccines were also able to increase survival in mice with pre-established tumors. The response elicited by GM-CSF-producing vaccines was found to be specific to tumor type and to be abrogated by depletion of CD8+ cells. Unlike the immunity generated against subcutaneous tumors by GM-CSF, however, the effector responses generated against tumors in the CNS were not dependent on CD4+ cells. These data suggest that cytokine-producing tumor cells are very potent stimulators of immunity against tumors within the CNS, but effector responses in the CNS may be different from those obtained against subcutaneous tumors.
Vagus nerve stimulation: current concepts (2008)

Vagus nerve stimulation (VNS) has become an accepted treatment option for pharmacologically resistant epilepsy. Although initially approved for adults, it increasingly has gained acceptance in children. In this article the author reviews the current state of knowledge of VNS therapy and discusses its potential utility.
Review lecture - The determinants of growth and form (1974)

Abstract An animal can only achieve its full genetic potential if it has lived its life in an ideal environ­ment. Few environments are ideal; they may be unfavourable for numerous reasons and for different lengths of time. Indeed, variations on these themes are almost infinitely possible, but concrete examples will be selected and their effects on the lives of animals and of man demonstrated. Time comes into all this, but its importance and the difference between chronological and biological time have not been properly appreciated. The interactions of time and the environment on the growth of animals and of their organs are complex, but recent work on malnutrition and growth has given us some insight into the matter. Theories that have been formulated are discussed, but none of those yet put forward explain all the facts that can be demonstrated experimentally, and studies that might provide clues have been neglected.
Alternative Splicing Controls the Mechanisms of FAK Autophosphorylation (2002)

Focal adhesion kinase (FAK) is activated following integrin engagement or stimulation of transmembrane receptors. Autophosphorylation of FAK on Tyr-397 is a critical event, allowing binding of Src family kinases and activation of signal transduction pathways. Tissue-specific alternative splicing generates several isoforms of FAK with different autophosphorylation rates. Despite its importance, the mechanisms of FAK autophosphorylation and the basis for differences between isoforms are not known. We addressed these questions using isoforms of FAK expressed in brain. Autophosphorylation of FAK(+), which is identical to that of "standard" FAK, was intermolecular in transfected cells, although it did not involve the formation of stable multimeric complexes. Coumermycin-induced dimerization of gyrase B-FAK(+) chimeras triggered autophosphorylation of Tyr-397. This was independent of cell adhesion but required the C terminus of the protein. In contrast, the elevated autophosphorylation of FAK(+6,7), the major neuronal splice isoform, was not accounted for by transphosphorylation. Specifically designed immune precipitate kinase assays confirmed that autophosphorylation of FAK(+) was intermolecular, whereas autophosphorylation of FAK(+6,7) or FAK(+7) was predominantly intramolecular and insensitive to the inhibitory effects of the N-terminal domain. Our results clarify the mechanisms of FAK activation and show how alternative splicing can dramatically alter the mechanism of autophosphorylation of a protein kinase.
Interferometric phase-dispersion microscopy (2000)

We describe a new scanning microscopy technique, phase-dispersion microscopy (PDM). The technique is based on measuring the phase difference between the fundamental and the second-harmonic light in a novel interferometer. PDM is highly sensitive to subtle refractive-index differences that are due to dispersion (differential optical path sensitivity, 5 nm). We apply PDM to measure minute amounts of DNA in solution and to study biological tissue sections. We demonstrate that PDM performs better than conventional phase-contrast microscopy in imaging dispersive and weakly scattering samples.
Multipoint Design Optimization of a Transonic Compressor Blade by Using an Adjoint Method (2013)

This paper presents the application of a viscous adjoint method to the multipoint design optimization of a rotor blade through blade profiling. The adjoint method requires about twice the computational effort of the flow solution to obtain the complete gradient information at each operating condition, regardless of the number of design parameters. NASA Rotor 67 is redesigned through blade profiling. A single point design optimization is first performed to verify the effectiveness and feasibility of the optimization method. Then in order to improve the performance for a wide range of operating conditions, the blade is redesigned at three operating conditions: near peak efficiency, near stall, and near choke. Entropy production through the blade row combined with the constraints of mass flow rate and total pressure ratio is used as the objective function. The design results are presented in detail and the effects of blade profiling on performance improvement and shock/tip-leakage interaction are examined.
Demonstration of multiple phenotypic diversity in a murine melanoma of recent origin. (1981)

The purpose of these studies was to examine whether the metastatic heterogeneity that is frequently found in serially transplanted neoplasms could be observed in a murine melanoma of recent origin. The primary K-1735 melanoma that arose in an inbred C3H/HeN murine mammary tumor virus-negative (C3H-) mouse was transplanted once into an immunosuppressed recipient and then established in culture. Cells from the fifth in vitro passage were used to produce clones. The parent K-1735 and 22 cloned lines were tumorigenic in syngeneic and outbred N:NIH(S) nude mice. Metastatic properties were assessed by observing the ability of the cells to produce pulmonary and extrapulmonary lesions after they were injected iv into 6-week-old C3H- mice. The number of metastases produced, their relative size, and pigmentation varied dramatically among the clones. Only 2 of 22 clones were indistinguishable from the parent tumor. Most of the nonmetastatic (but tumorigenic clones) were also nonmetastatic in 3-week-old nude mice, which suggests that the absence of metastasis formation was not merely due to their immunologic rejection by the normal C3H- mouse. Control subcloning experiments demonstrated that the procedure of cloning in vitro was not responsible for the variability among the clones. The clones did not differ in their karyotype or cell size, but they did differ in their growth rate in vitro. These phenotypes, however, did not correlate with metastatic propensity. In conclusion, the K-1735, a murine melanoma of most recent origin, is heterogeneous and contains subpopulations of cells with diverse biologic behavior.
Formation of Isobutene from 3-Hydroxy-3-Methylbutyrate by Diphosphomevalonate Decarboxylase (2010)

Isobutene is an important commercial chemical used for the synthesis of butyl rubber, terephthalic acid, specialty chemicals, and a gasoline performance additive known as alkylate. Currently, isobutene is produced from petroleum and hence is nonrenewable. Here, we report that the Saccharomyces cerevisiae mevalonate diphosphate decarboxylase (ScMDD) can convert 3-hydroxy-3-methylbutyrate (3-HMB) to isobutene. Whole cells of Escherichia coli producing ScMDD with an N-terminal 6×His tag (His(6)-ScMDD) formed isobutene from 3-HMB at a rate of 154 pmol h(-1) g cells(-1). In contrast, no isobutene was detected from control cells lacking ScMDD. His(6)-ScMDD was purified by nickel affinity chromatography and shown to produce isobutene from 3-HMB at a rate of 1.33 pmol min(-1) mg(-1) protein. Controls showed that both His(6)-ScMDD and 3-HMB were required for detectable isobutene formation. Isobutene was identified by gas chromatography (GC) with flame ionization detection as well as by GC-mass spectrometry (MS). ScMDD was subjected to error-prone PCR, and two improved variants were characterized, ScMDD1 (I145F) and ScMDD2 (R74H). Whole cells of E. coli producing ScMDD1 and ScMDD2 produced isobutene from 3-HMB at rates of 3,000 and 5,888 pmol h(-1) g cells(-1), which are 19- and 38-fold increases compared to rates for cells producing His(6)-ScMDD. This showed that genetic modifications can be used to increase the rate at which ScMDD converts 3-HMB to isobutene. Because 3-HMB can be produced from l-leucine, ScMDD has a potential application for the production of renewable isobutene. Moreover, isobutene is a gas, which might simplify its purification from a fermentation medium, substantially reducing production costs.