gebhart/patrepeval huggingface dataset:
Über die Einwirkung von Haloform auf Steroidcarbonylfunktionen (1958)

Abstract 3‐Keto‐Steroide lassen sich bei tiefen Temperaturen mit Chloroform und Kalium‐tert.‐butylat in 3‐Hydroxy‐3‐trichlormethyl‐Verbindungen überführen. Beim 16‐Dehydro‐pregnenolon erhält man durch entsprechende Umsetzung mit Bromoform das 16α‐Tribrom‐pregnenolon. Dadurch ergibt sich eine neue Synthese für 16α‐Methyl‐progesteron. Durch Reaktion der 17‐Formylgruppe mit Chloroform entstehen 21.21.21‐Trichlor‐20‐hydroxy‐Steroide. Auf diesem Wege kann man unter anderem 21.21.21‐Trichlor‐progesteron synthetisieren.
All-CMOS temperature compensated current reference (2010)

This paper presents a novel temperature independent current reference based on the theory of mutual compensation of mobility and threshold voltage. It is completely compatible with standard CMOS-technology. The experiment results indicate that the temperature coefficient of this current reference is less than 290 ppm/°C over a temperature range from −20 to 110°C.
In <i>Pichia pastoris</i>, growth rate regulates protein synthesis and secretion, mating and stress response (2013)

Protein production in yeasts is related to the specific growth rate μ. To elucidate on this correlation, we studied the transcriptome of Pichia pastoris at different specific growth rates by cultivating a strain secreting human serum albumin at μ = 0.015 to 0.15 h(-1) in glucose-limited chemostats. Genome-wide regulation revealed that translation-related as well as mitochondrial genes were upregulated with increasing μ, while autophagy and other proteolytic processes, carbon source-responsive genes and other targets of the TOR pathway as well as many transcriptional regulators were downregulated at higher μ. Mating and sporulation genes were most active at intermediate μ of 0.05 and 0.075 h(-1) . At very slow growth (μ = 0.015 h(-1) ) gene regulation differs significantly, affecting many transporters and glucose sensing. Analysis of a subset of genes related to protein folding and secretion reveals that unfolded protein response targets such as translocation, endoplasmic reticulum genes, and cytosolic chaperones are upregulated with increasing growth rate while proteolytic degradation of secretory proteins is downregulated. We conclude that a high μ positively affects specific protein secretion rates by acting on multiple cellular processes.
Continuous Formation of CO<sub>2</sub> Hydrate via a Kenics-Type Static Mixer (2004)

Formation of CO2 hydrate using a Kenics-type static mixer was studied experimentally. The flows of liquid CO2 and water were mixed in the static mixer, and CO2 hydrate was formed continuously from the two-phase flow. The patterns of hydrate formation were found to be dependent on the flow velocities of liquid CO2 and water. The flow of agglomerated hydrate chunks in water occurred under relatively CO2-rich conditions, while dispersed flow of tiny particles of CO2 hydrate with small liquid CO2 drops was observed under relatively water-rich conditions. These effects could be explained by two mechanisms occurring in the static mixer, namely, continuous shedding of hydrate films from the interface between liquid CO2 and water induced by the shearing force and breakup of the CO2 drops. The energy consumption by the static mixer for the hydrate formation process was estimated, and it was significantly less than that for a stirring vessel type reactor. A continuous hydrate formation process could be achieved using the static mixer.
Both the <i>cis</i> - <i>trans</i> equilibrium and isomerization dynamics of a single proline amide modulate β2-microglobulin amyloid assembly (2013)

The human protein β2-microglobulin (β2m) aggregates as amyloid fibrils in patients undergoing long-term hemodialysis. Isomerization of Pro32 from its native cis to a nonnative trans conformation is thought to trigger β2m misfolding and subsequent amyloid assembly. To examine this hypothesis, we systematically varied the free-energy profile of proline cis-trans isomerization by replacing Pro32 with a series of 4-fluoroprolines via total chemical synthesis. We show that β2m's stability, (un)folding, and aggregation properties are all influenced by the rate and equilibrium of Pro32 cis-trans isomerization. As anticipated, the β2m monomer was either stabilized or destabilized by respective incorporation of (2S,4S)-fluoroproline, which favors the native cis amide bond, or the stereoisomeric (2S,4R)-fluoroproline, which disfavors this conformation. However, substitution of Pro32 with 4,4-difluoroproline, which has nearly the same cis-trans preference as proline but an enhanced isomerization rate, caused pronounced destabilization of the protein and increased oligomerization at neutral pH. More remarkably, these subtle alterations in chemical composition--incorporation of one or two fluorine atoms into a single proline residue in the 99 amino acid long protein--modulated the aggregation properties of β2m, inducing the formation of polymorphically distinct amyloid fibrils. These results highlight the importance of conformational dynamics for molecular assembly of an amyloid cross-β structure and provide insights into mechanistic aspects of Pro32 cis-trans isomerism in β2m aggregation.
Mechanical and electrical properties of CdTe tetrapods studied by atomic force microscopy (2007)

The mechanical and electrical properties of CdTe tetrapod-shaped nanocrystals have been studied with atomic force microscopy. Tapping mode images of tetrapods deposited on silicon wafers revealed that they contact the surface with three of its arms. The length of these arms was found to be 130+/-10 nm. A large fraction of the tetrapods had a shortened vertical arm as a result of fracture during sample preparation. Fracture also occurs when the applied load is a few nanonewtons. Compression experiments with the atomic force microscope tip indicate that tetrapods with the shortened vertical arm deform elastically when the applied force was less than 50 nN. Above 90 nN additional fracture events occurred that further shortened the vertical arm. Loads above 130 nN produced irreversible damage to the other arms as well. Current-voltage characteristics of tetrapods deposited on gold revealed a semiconducting behavior with a current gap of approximately 2 eV at low loads (<50 nN) and a narrowing to about 1 eV at loads between 60 and 110 nN. Atomistic force field calculations of the deformation suggest that the ends of the tetrapod arms are stuck during compression so that the deformations are due to bending modes. Empirical pseudopotential calculation of the electron states indicates that the reduction of the current gap is due to electrostatic effects, rather than strain deformation effects inside the tetrapod.
Novel Role for a Sterol Response Element Binding Protein in Directing Spermatogenic Cell-Specific Gene Expression (2004)

Sperm are highly specialized cells, and their formation requires the synthesis of a large number of unique mRNAs. However, little is known about the transcriptional mechanisms that direct male germ cell differentiation. Sterol response element binding protein 2gc (SREBP2gc) is a spermatogenic cell-enriched isoform of the ubiquitous transcription factor SREBP2, which in somatic cells is required for homeostatic regulation of cholesterol. SREBP2gc is selectively enriched in spermatocytes and spermatids, and, due to its novel structure, its synthesis is not subject to cholesterol feedback control. This suggested that SREBP2gc has unique cell- and stage-specific functions during spermatogenesis. Here, we demonstrate that this factor activates the promoter for the spermatogenesis-related gene proacrosin in a cell-specific manner. Multiple SREBP2gc response elements were identified within the 5'-flanking and proximal promoter regions of the proacrosin promoter. Mutating these elements greatly diminished in vivo expression of this promoter in spermatogenic cells of transgenic mice. These studies define a totally new function for an SREBP as a transactivator of male germ cell-specific gene expression. We propose that SREBP2gc is part of a cadre of spermatogenic cell-enriched isoforms of ubiquitously expressed transcriptional coregulators that were specifically adapted in concert to direct differentiation of the male germ cell lineage.
Pendent Accelerator Groups in Rubber Vulcanizates (1970)

Abstract A rapid build-up of pendent accelerator groups in the initial stages of vulcanization of natural rubber has shown that they are the precursors to the formation of crosslinks. Larger amounts of attached accelerator fragments were found for efficient and so-called sulfurless systems than for conventional accelerator-sulfur systems especially at short cure times. Cleavage of disulfides and polysulfides in the pendent groups by hexanethiol in piperidine showed a build-up of di- and polysulfides in the initial stages corresponding to that of accelerator fragments. Analyses were made by liquid scintillation counting using 14 C-labeled accelerators. Due to the necessity of using liquid samples, vulcanizates were degraded in xylene solution with tert butyl hydroperoxide using osmium tetroxide as a catalyst. The use of a dual vulcanization system of dicumyl peroxide followed by the addition of sulfur and labeled accelerator by swelling techniques made possible the determination of accelerator fragments at short cure times when their concentration was the greatest. Polysulfides were found to have a profound and detrimental effect on the hardening of SBR during accelerated aging in air. An increase in attached accelerator fragments was found to take place during aging which may contribute to additional crosslinking and hardening.
CPV 101: Intro to CPV Technology, Opportunities and Challenges (Presentation) (2009)

The presentation describes Concentrating Photovoltaic power (CPV), why it is important, the associated the opportunities and challenges, and more than 5-dozen companies that are pursuing the approach.
Adaptive Classifiers-Ensemble System for Tracking Concept Drift (2007)

Adapting to various types of concept drift is important for dealing with real-world online learning problems. To achieve this, we previously reported an online learning system that uses an ensemble of classifiers, the adaptive classifiers-ensemble (ACE) system. ACE consists of one online classifier, many batch classifiers, and a drift detection mechanism. To improve the performance of ACE, we have improved the weighting method, which combines the outputs of classifiers, and have added a new classifier pruning method. Experimental results showed that the enhanced ACE performed well for a synthetic dataset that contained both sudden and gradual changes and recurring concepts.
Nonconvexity of the capacity region of the multiple-access arbitrarily varying channel subject to constraints (1995)

The random-code capacity region of a multiple-access arbitrarily varying channel subject to both state and input constraints is determined. Consideration of a simple erasure channel shows that the capacity region is not convex in general.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Heilmittelchemische Studien in der heterocyclischen Reihe. 5. Mitteilung. Pyridazine II. Eine neue Pyridazinsynthese (1954)

Abstract A new synthesis of 6‐pyridazones starting from three single components is described. The starting materials are (1) and α‐diketone, α‐ketoaldehyde or glyoxal, (2) a carbonic acid having an active methylene group in α‐position, and (3) hydrazine or a monosubstituted hydrazine.
1. Solanum alkaloids. Part I. The alkaloid from the fruit of Solanum aviculare (1942)

R. C. Bell and L. H. Briggs, J. Chem. Soc., 1942, 1 DOI: 10.1039/JR9420000001
Production of hydroxyl radicals by tumor cells varies with cell type as measured by electron spin resonance spectrometry. (1991)

The hydroxyl radicals produced by two adherent cell lines, a human cancer cell and a mouse fibroblast, and six suspended human leukemia cell lines at different stages of differentiation were measured by electron spin resonance (ESR) spectrometry. The concentration of hydroxyl radicals detected in these tumor cells increased in proportion to temperature and cell number. The addition of the enzymes superoxide dismutase (SOD) and catalase (which do not permeate the cell membrane), reduced the amount of hydroxyl radicals detected. SOD decreased hydroxyl radicals somewhat but catalase eliminated hydroxyl radicals almost completely. These findings suggest that hydroxyl radicals are produced extracellularly consisted primarily of H2O2 but partially from superoxide radicals. Using the human leukemia cell lines at different stages of differentiation we demonstrated that cell differentiation may correlate with hydroxyl radical production. The earlier the stage of leukemic cell differentiation the more the greater the production of hydroxyl radicals. Moreover, the ability of SOD or catalase to eliminate hydroxyl radical activity correlated inversely with leukemic cell differentiation.
<scp>PTPRN</scp> 2 and <scp>PLC</scp> β1 promote metastatic breast cancer cell migration through <scp>PI</scp> (4,5)P <sub>2</sub> ‐dependent actin remodeling (2015)

Altered abundance of phosphatidyl inositides (PIs) is a feature of cancer. Various PIs mark the identity of diverse membranes in normal and malignant cells. Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) resides predominantly in the plasma membrane, where it regulates cellular processes by recruiting, activating, or inhibiting proteins at the plasma membrane. We find that PTPRN2 and PLCβ1 enzymatically reduce plasma membrane PI(4,5)P2 levels in metastatic breast cancer cells through two independent mechanisms. These genes are upregulated in highly metastatic breast cancer cells, and their increased expression associates with human metastatic relapse. Reduction in plasma membrane PI(4,5)P2 abundance by these enzymes releases the PI(4,5)P2-binding protein cofilin from its inactive membrane-associated state into the cytoplasm where it mediates actin turnover dynamics, thereby enhancing cellular migration and metastatic capacity. Our findings reveal an enzymatic network that regulates metastatic cell migration through lipid-dependent sequestration of an actin-remodeling factor.
Ultrahigh-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Q</mml:mi></mml:math>Tunable Whispering-Gallery-Mode Microresonator (2009)

Typical microresonators exhibit a large frequency spacing between resonances and a limited tunability. This impedes their use in a large class of applications which require a resonance of the microresonator to coincide with a predetermined frequency. Here, we experimentally overcome this limitation with highly prolate-shaped whispering-gallery-mode "bottle microresonators" fabricated from standard optical glass fibers. Our resonators combine an ultrahigh quality factor of 3.6 x 10(8), a small mode volume, and near-lossless fiber coupling, characteristic of whispering-gallery-mode resonators, with a simple and customizable mode structure enabling full tunability.
The S variant of human α<sub>1</sub>-antitrypsin, structure and implications for function and metabolism (1989)

The S variant of the human alpha 1-antitrypsin with E-264----V, is responsible for a mild alpha 1-antitrypsin deficiency quite common in the European population. S protein specifically cleaved at the susceptible peptide bond was crystallized and its crystal structure determined and refined to 3.1 A resolution. The S variant crystallizes isomorphous to the normal M variant. The difference Fourier electron density map shows the E----V change as outstanding residual density. In addition, small structural changes of the main polypeptide chain radiate from the site of mutation and affect parts far removed from it. By the mutation, internal hydrogen bonds and salt linkages of E-264 to Y-38 and K-487, respectively, are lost. They cause the far-reaching slight distortions and are probably related to the reduced thermal stability of the S mutant. They may also be responsible for slower folding of the polypeptide chain and the clinical symptoms of alpha 1-antitrypsin deficiency. In a theoretical study by molecular dynamics methods simulations of the M and S proteins were made and the results analysed with respect to structural and dynamic properties and compared with the experimental results. There is a significant correlation between experimental and theoretical results in some respects.
ELECTRONIC MONITORING OF VITAL SIGNS (1965)

MRS. GEORGE (B.S., Kansas State University, Manhattan, Kans.; M.A., Iowa State University) is instructor of medical-surgical nursing at Bethany Hospital in Kansas City, Kan., where pioneering work has been done in the use of monitoring devices.
Functionalized polypropylene prepared by melt free radical grafting of low volatile oxazoline and its potential in compatibilization of PP/PBT blends (1996)

This article concerns the functionalization of polypropylene (PP) with oxazoline functionality by melt free radical grafting along with a low degree of degradation of PP in a batch mixer. A low volatile oxazoline, ricinoloxazoline maleinate (OXA), was used as the monomer. The grafting yield of OXA ranged from about 0.5 phr up to 1.5 phr (grams per 100 grams of PP) when its initial concentration and that of the peroxide ranged from 1.5 to 6.0 phr and 0.1 to 0.7 phr, respectively. The corresponding conversion of OXA to grafted OXA ranged from about 15 to 50%. Addition of styrene (St) as the comonomer did not enhance the grafting yield of OXA but markedly reduced the PP degradation. Also, little homo-and/or copolymers of OXA and/or St were found in the grafting system. This agrees with our finding that OXA and St did not copolymerize easily. The potential of using an OXA modified PP (PP-g-OXA) as the compatibilizer precursor in PP/PBT blends was examined as well. The presence of PP-g-OXA reduced the particle size of the dispersed phase (PBT) along with improved cohesion between the PP and PBT phases. This is consistent with a model kinetic study, which showed that the reaction between oxazoline and carboxylic functionalities was very fast. © 1996 John Wiley & Sons, Inc.
Focal Contacts as Mechanosensors (2001)

The transition of cell-matrix adhesions from the initial punctate focal complexes into the mature elongated form, known as focal contacts, requires GTPase Rho activity. In particular, activation of myosin II-driven contractility by a Rho target known as Rho-associated kinase (ROCK) was shown to be essential for focal contact formation. To dissect the mechanism of Rho-dependent induction of focal contacts and to elucidate the role of cell contractility, we applied mechanical force to vinculin-containing dot-like adhesions at the cell edge using a micropipette. Local centripetal pulling led to local assembly and elongation of these structures and to their development into streak-like focal contacts, as revealed by the dynamics of green fluorescent protein-tagged vinculin or paxillin and interference reflection microscopy. Inhibition of Rho activity by C3 transferase suppressed this force-induced focal contact formation. However, constitutively active mutants of another Rho target, the formin homology protein mDia1 (Watanabe, N., T. Kato, A. Fujita, T. Ishizaki, and S. Narumiya. 1999. Nat. Cell Biol. 1:136-143), were sufficient to restore force-induced focal contact formation in C3 transferase-treated cells. Force-induced formation of the focal contacts still occurred in cells subjected to myosin II and ROCK inhibition. Thus, as long as mDia1 is active, external tension force bypasses the requirement for ROCK-mediated myosin II contractility in the induction of focal contacts. Our experiments show that integrin-containing focal complexes behave as individual mechanosensors exhibiting directional assembly in response to local force.
Lymph node blood vessels provide exit routes for metastatic tumor cell dissemination in mice (2018)

During metastasis, malignant cells escape the primary tumor, intravasate lymphatic vessels, and reach draining sentinel lymph nodes before they colonize distant organs via the blood circulation. Although lymph node metastasis in cancer patients correlates with poor prognosis, evidence is lacking as to whether and how tumor cells enter the bloodstream via lymph nodes. To investigate this question, we delivered carcinoma cells into the lymph nodes of mice by microinfusing the cells into afferent lymphatic vessels. We found that tumor cells rapidly infiltrated the lymph node parenchyma, invaded blood vessels, and seeded lung metastases without involvement of the thoracic duct. These results suggest that the lymph node blood vessels can serve as an exit route for systemic dissemination of cancer cells in experimental mouse models. Whether this form of tumor cell spreading occurs in cancer patients remains to be determined.
FDTD Modeling of Biological Tissues Cole–Cole Dispersion for 0.5–30 GHz Using Relaxation Time Distribution Samples—Novel and Improved Implementations (2009)

In this paper, novel finite-difference time-domain implementations of the Cole-Cole dispersion model for biological tissues, from 0.5 to 30 GHz, based on the sampling of the distribution of relaxation time, and the convolution integral formulation, are provided and verified. Moreover, shortcomings of the original relaxation time sampling implementation, with polarization formulation, were identified, and the improved polarization implementation is provided as well. These implementations are compared with the implementation utilizing the fractional derivative formulation. All compared implementations require storing the electric field and some related auxiliary quantities for only the previous time step. It is observed that, for a single-term Cole-Cole relation, relaxation time sampling implementations can provide accuracy, storage requirement, and simulation time comparable to the ones for the fractional derivative implementation. However, the latter does not exist for the more general multiterm Cole-Cole dispersion relation, for which the implementations based on the relaxation time sampling could be easily extended to.