gebhart/patrepeval huggingface dataset:
High‐performance liquid chromatography method for determination of carnosic acid in rat plasma and its application to pharmacokinetic study (2009)

A sensitive and reproducible high-performance liquid chromatography method with ultraviolet detection (UV) was developed for the determination of carnosic acid (CA) in rat plasma. After simple acidification and liquid-liquid extraction of plasma samples using gemfibrozil as an internal standard, the supernatant was evaporated to dryness under a gentle stream of nitrogen. The residue was reconstituted in 200 microL before being injected into the chromatographic system. The analysis was performed on a C(18) column protected by an ODS guard column using acetonitrile-0.1% phosphoric acid (55:45, v/v) as mobile phase, and the wavelength of the UV detector was set at 210 nm. The calibration curve was linear over the range of 0.265-265.0 microg/mL with a correlation coefficient of 0.9997. The recovery for plasma samples of 0.530, 13.25, 132.5 and 265.0 microg/mL was 72.2, 87.9, 90.4 and 94.7%, respectively. The intra-day and inter-day relative standard deviations for the measurements of quality control samples were less than 3.1%. The stability of the plasma samples was also validated. This method was successfully used to study the pharmacokinetics and bioavailability of CA in rats.
SUGGESTED INVOLVEMENT OF CALCIUM AND CALMODULIN IN THE RESPONSES OF STOMATA TO ABSCISIC ACID (1985)

S ummary A requirement for calcium during the inhibition of stomatal opening by abscisic acid (ABA) was reported in a previous study, and evidence is now presented which gives further indications of the part played by calcium. Calcium‐channel blockers (lanthanum, verapamil and nifedipine) reduced the ability of stomata to respond to ABA. A calcium ionophore (A 23187) reduced stomatal opening, presumably because it mimicked the effect of ABA in increasing permeability of the plasma membrane to calcium. In the presence of three calmodulin antagonists, the inhibitory effect of ABA was much reduced. The synthetic auxin naphth‐l‐ylacetic acid (NAA) prevented stomatal opening, but this action did not appear to be dependent on calcium ions. It is suggested that the action of ABA on guard cells requires a free passage of calcium ions into the cytosol. They may act as second messengers, interacting with calmodulin to produce the overt cellular responses to ABA. Although the data presented apply only to stomata, these experiments may have provided insight into the basic mechanism by which ABA acts on cellular processes. It is suggested that some reported effects of Ca 2+ on the action of other plant growth substances could have resulted from complex interactions involving endogenous ABA.
Tooth Movement (1991)

This article reviews the evolution of concepts regarding the biological foundation of force-induced tooth movement. Nineteenth century hypotheses proposed two mechanisms: application of pressure and tension to the periodontal ligament (PDL), and bending of the alveolar bone. Histologic investigations in the early and middle years of the 20th century revealed that both phenomena actually occur concomitantly, and that cells, as well as extracellular components of the PDL and alveolar bone, participate in the response to applied mechanical forces, which ultimately results in remodeling activities. Experiments with isolated cells in culture demonstrated that shape distortion might lead to cellular activation, either by opening plasma membrane ion channels, or by crystallizing cytoskeletal filaments. Mechanical distortion of collagenous matrices, mineralized or non-mineralized, may, on the other hand, evoke the development of bioelectric phenomena (stress-generated potentials and streaming potentials) that are capable of stimulating cells by altering the electric charge on their membrane or their fluid envelope. In intact animals, mechanical perturbations on the order of about 1 min/d are apparently sufficient to cause profound osteogenic responses, perhaps due to matrix proteoglycan-related "strain memory". Enzymatically isolated human PDL cells respond biochemically to mechanical and chemical signals. The latter include endocrines, autocrines, and paracrines. Histochemical and immunohistochemical studies showed that during the early places of tooth movement, PDL fluids are shifted, and cells and matrix are distorted. Vasoactive neurotransmitters are released from periodontal nerve terminals, causing leukocytes to migrate out of adjacent capillaries. Cytokines and growth factors are secreted by these cells, stimulating PDL cells and alveolar bone lining cells to remodel their related matrices. This remodeling activity facilitates movement of teeth into areas in which bone had been resorbed. This emerging information suggests that in the living mammal, many cell types are involved in the biological response to applied mechanical stress to teeth, and thereby to bone. Essentially, cells of the nervous, immune, and endocrine systems become involved in the activation and response of PDL and alveolar bone cells to applied stresses. This fact implies that research in the area of the biological response to force application to teeth should be sufficiently broad to include explorations of possible associations between physical, cellular, and molecular phenomena. The goals of this investigative field should continue to expound on fundamental principles, particularly on extrapolating new findings to the clinical environment, where millions of patients are subjected annually to applications of mechanical forces to their teeth for long periods of time in an effort to improve their position in the oral cavity.(ABSTRACT TRUNCATED AT 400 WORDS)
Vida artificial: una perspectiva (1998)

Glufosinate is a common herbicide with neurotoxic effects, leading to seizures, convulsions and memory loss. Glufosinate indirectly induces glutamate toxicity by inhibiting glutamine synthesis in astrocytes. Here, we studied the acute toxic effects of a glufosinate-based herbicide in rat optic nerve at three doses (40, 80 or 120 μM, equal to 714 or 21 mg/kg bw/day). Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, glucose, calcium, as well as creatinine concentrations were analyzed after 24, 48 and 72 h treatment. Intraocular pressure (IOP) (expressed as the average of both eyes) was measured with a rebound tonometer. Interleukin-1β (IL-1β) and c-Fos expression were determined by immunohistochemistry. The results established that the glufosinate-based herbicide significantly increased IL-1β and c-Fos immunopositivity in the optic nerve (p < 0.05), concomitant with increased IOP. These results suggest that commercial formulations of glufosinate acutely affect the optic nerve.
Thermal degradation kinetics of poly(propylene carbonate) obtained from the copolymerization of carbon dioxide and propylene oxide (2003)

Abstract The kinetics of the thermal degradation of poly(propylene carbonate) (PPC) were investigated with different kinetic methods with data from thermogravimetric analysis under dynamic conditions. The apparent activation energies obtained with different integral methods (Ozawa–Flynn–Wall and Coats–Redfern) were consistent with the values obtained with the Kinssinger method (99.93 kJ/mol). The solid‐state decomposition process was a sigmoidal A 3 type in terms of the Coats–Redfern and Phadnis–Deshpande results. The influence of the heating rate on the thermal decomposition temperature was also studied. The derivative thermogravimetry curves of PPC confirmed only one weight‐loss step. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 947–953, 2003
A Novel and Simplified Procedure for Patterning Hydrophobic and Hydrophilic SAMs for Microfluidic Devices by Using UV Photolithography (2006)

This work describes how selective patterning of hydrophobic and hydrophilic areas inside microchannels of microfluidic devices can be achieved by combining well-known chemical protocols and standard photolithography equipment (365 nm). Two techniques have been performed and compared. The first technique is based on the preparation of self-assembled monolayers of photocleavable organosilane and the second one on photoassisted grafting (365 nm) of self-assembled monolayers (SAMs) on a silicon or glass substrate. In the first case, we begin with monolayers carrying an o-nitrobenzyl function (hydrophobic area) that is photochemically cleaved, revealing a carboxylic acid group (hydrophilic area). The problem is that the energy necessary to cleave this monolayer is too high and the reaction time is more than 1 h with 50 mW/cm(2) irradiation flux. To overcome this practical disadvantage, we propose another approach that is based on the thiol-ene reaction with benzophenone as photoinitiator. In this approach, a monolayer of mercaptopropyltrimethoxysilane (MPTS) is prepared first. Subsequently, a hydrocarbon chain is photografted locally onto the thiol layer, forming a hydrophobic surface while the reminding unmodified thiol surface is oxidized into sulfonic acid (hydrophilic area). We demonstrated the feasibility of this approach and synthesized high-quality self-assembled monolayers by UV grafting with an irradiation time of 30 s at 365 nm (50 mW/cm(2)). The modified surfaces have been characterized by contact angle measurements, X-ray photoelectron spectroscopy (XPS), AFM, and multiple internal reflection infrared spectroscopy (MIR-FTIR). The difference in the contact angles on the hydrophilic and hydrophobic surfaces reached a remarkable 77 degrees. We have also demonstrated that this method is compatible with selective surface grafting inside microfluidic channels.
Elicitors, Effectors, and <i>R</i> Genes: The New Paradigm and a Lifetime Supply of Questions (2007)

The plant basal immune system can detect broadly present microbe-associated molecular patterns (MAMPs, also called PAMPs) and induce defenses, but adapted microbes express a suite of effector proteins that often act to suppress these defenses. Plants have evolved other receptors (R proteins) that detect these pathogen effectors and activate strong defenses. Pathogens can subsequently alter or delete their recognized effectors to avoid defense elicitation, at risk of a fitness cost associated with loss of those effectors. Significant research progress is revealing, among other things, mechanisms of MAMP perception, the host defense processes and specific host proteins that pathogen effectors target, the mechanisms of R protein activation, and the ways in which pathogen effector suites and R genes evolve. These findings carry practical ramifications for resistance durability and for future resistance engineering. The present review uses numerous questions to help clarify what we know and to identify areas that are ripe for further investigation.
Turning and Walking by Gilts in Modified Gestation Crates (1988)

Mated gilts in gestation crates designed specially so gilts could turn or walk at will did turn around and walk. In Exp. 1, in crates 2.1 m long, flared at one end and pointed at the other, and 56 or 61 cm wide at center, gilts' turning frequency averaged 11.2 turns/d. Neither feeder nor waterer location, independent of the other, influenced turning frequency. Most turns apparently were not motivated by any obvious external stimulus. Narrowing crates from 61 to 56 cm reduced turning rate from 12.9/d to 8.9/d. Gilts spent more time facing the feeder when it was at the flared end (F; 66.1%) than when it was at the pointed end (P; 49.4%). Turning was followed by standing or lying, without simultaneous eating or drinking, 65.3% of the time. A greater proportion of turns were succeeded by eating or drinking when feeder and waterer were located in opposite ends of the crate (39.2%) instead of in the same end (29.7%). As a result of turns followed by only standing or lying, gilts were oriented head by head 52.9% of the times. Mean time of day for turning was 1016 in wide crates and 0855 in narrow crates. Also, mean turning time with waterer at P vs at F was 1012 vs 0928. In Exp. 2, a 2 X 2 factorial arrangement of treatments compared crates that were either 2.1 m or 3.4 m long and had either flared or rectangular ends. Neither length nor shape affected gilts' total daily duration of standing. Gilts stood up 8.3 times/d in rectangular crates, 13.9 times/d in flared.(ABSTRACT TRUNCATED AT 250 WORDS)
Ferrite particles: a superparamagnetic MR contrast agent for enhanced detection of liver carcinoma. (1987)

The potential of superparamagnetic ferrite particles to enhance detection of liver carcinoma at magnetic resonance (MR) imaging was studied with in vitro MR spectroscopy and in vivo MR imaging in animal models. After intravenous administration of ferrite, MR spectroscopy showed selective shortening of T2 relaxation times in normal liver but not in tumor. MR imaging showed that ferrite produced profound signal loss only from normal liver and not tumor; thus, differences in signal intensity between liver and tumor were greatly enhanced, especially on pulse sequences with T2-dependent contrast. Motion artifacts were reduced as well because of less signal from liver. Microscopic analysis showed sequestration of ferrite particles in hepatic reticuloendothelial cells but not in hepatocytes or tumor tissue, and there was no evidence of cellular injury. Ferrite particles efficiently and predictably enhance signal differences between normal liver and tumor and permit considerable latitude in selection of pulse sequence and timing parameters. Thus, they have considerable promise as a tissue-specific MR contrast agent for improved detection of liver carcinoma.
On the Psychophysics of Workload: Why Bother with Subjective Measures? (1984)

Psychophysical functions describe the relationship between variations in the amplitude of a defined physical quantity and the psychological perception of these changes. Examples are brightness, loudness, and pain. The regularities of these relationships have been formulated into psychophysical laws. The measurement methodology of psychophysical scaling has been refined by the Harvard group led by S. S. Stevens, who proposed a power function as a general form for such laws. The main argument of the present article is that a similar scaling approach can be adapted to the measurement of workload and task demands based upon subjective estimates. The rationale is that these estimates, like other psychophysical judgments, reflect the individual's perception of the amount of processing resources that the subject invests to meet the demand imposed by a task. This approach was successfully applied to the assessment of 21 experimental conditions given to a group of 60 subjects. The paper discusses the main results of this effort and their implications to theory and application in human performance.
Performance Analysis of SyncML Server System Using Stochastic Petri Nets (2004)

Synchronization Markup Language (SyncML) is a specification of a common data synchronization framework for synchronizing data on networked devices. SyncML is designed for use between mobile devices that are intermittently connected to a network and network services that are continuously available on the network. We have designed and developed a data synchronization system based on the SyncML protocol and evaluated the throughput of the system using the stochastic Petri nets package (SPNP) and analyzed the relationship between the arrival rate and the system resources. Using this model, we evaluate various performance measures in different situations, and we estimate the relationship between the arrival rate and the system resources. From the results, we can estimate the optimal amount of resources due to the arrival rate before deploying the developed system.
Dynamic power allocation using Stackelberg game in a wireless sensor network (2016)

Wireless sensor networks are characterized by a limited availability of resources such as the power required for data transmission. Cooperative communication enables transmission of data without using too much power. The fading of data is considerably less when the nodes are engaged in a cooperative communication protocol, rather than a competitive game. The quintessential concern for each node is the power it needs to allocate in order to relay the other nodes data. In cooperative communication, the nodes need to transmit not only their own data, but the data of the neighboring nodes too. An efficient solution to this problem can be determined by employing the Stackelberg game. From the determined solutions, improvement in the cooperation among the neighboring nodes can be worked upon. A cooperation region can be established within which the nodes work towards transmitting the data more efficiently. A similar concept can be applied to multi-hop networks and N relay multi-hop networks. Thus, an optimal region of cooperation for a single node, which permits it to achieve maximum cooperation amongst all the other nodes at the same time can be determined. Since we employ a game theoretic approach, we can determine a trade off between quantities such as power allocated and utility of the nodes, which results in maximum optimization of the network. Through this paper, we aim to improve the network utility factor of the wireless sensor network through dynamic power allocation using the Stackelberg game.
Efficient trellis search algorithms for adaptive MLSE on fast Rayleigh fading channels (2002)

Analyzes trellis search algorithms for joint sequence estimation and channel tracking, assuming rapidly varying frequency-selective Rayleigh fading. The generalized Viterbi algorithm (GVA) and the M-algorithm (MA) are considered for approximately searching the maximum likelihood path in the trellis diagram and compared with the Viterbi algorithm (VA). All algorithms perform channel tracking utilizing per-survivor processing (PSP) techniques by associating a channel estimate to each hypothetical trellis path, according to the least mean square (LMS) or recursive least square (RLS) algorithm. To reproduce a typical mobile digital communication system, a time-division multiple access (TDMA) data frame is assumed, where each user transmits a block of information symbols with known preamble and tail. For Doppler bands up to one hundredth the symbol frequency and a three path delay profile, the MA is shown to exhibit a slightly better performance than the GVA for an equal number of survivors, and outperform the VA.
Identification of novel molecular candidates for fatty liver in the hyperlipidemic mouse model, HcB19 (2004)

The inbred HcB19 mouse strain expresses a truncated form of thioredoxin interacting protein and is phenotypically characterized by fatty liver and elevated plasma triglycerides and VLDL. Recently, these mice have been proposed as an animal model for familial combined hyperlipidemia. The aim of the present study was identification of hepatic proteins specifically associated with the presence of fatty liver. Eighteen differential proteins were detected in whole-liver homogenate from HcB19, or the parental strain C3H, using 2D electrophoresis, and 11 of those were successfully identified by mass spectrometry. Five of the identified differential proteins were mitochondrial, two peroxisomal, two cytosolic, and two secretory. Four differential proteins were novel in the fatty liver proteome [i.e., aconitase, succinate dehydrogenase, propionyl CoA carboxylase alpha chain (PCCA), and 3-hydroxyanthranilate 3,4 dioxygenase (3HAAO)]. Of these, PCCA and 3HAAO are of particular interest because of their known functions in nicotinic acid metabolism (3HAAO) and ketogenesis (PCCA). We have newly identified several differential proteins in the hepatic proteome of mice with fatty liver, including PCCA and 3HAAO, and confirmed differential expression of previously reported proteins. These individual proteins, PCCA and 3HAAO, can be important in development of fatty liver or in the expression of hyperlipidemia.
<title>Embedded and efficient low-complexity hierarchical image coder</title> (1998)

We propose an embedded hierarchical image coding algorithm of low complexity. It exploits two fundamental characteristics of an image transform -- the well defined hierarchical structure, and energy clustering in frequency and in space. The image coding algorithm developed here, apart from being embedded and of low complexity, is very efficient and is comparable to the best known low-complexity image coding schemes available today.
Regional differences in temperature sensation and thermal comfort in humans (2008)

Sensations evoked by thermal stimulation (temperature-related sensations) can be divided into two categories, "temperature sensation" and "thermal comfort." Although several studies have investigated regional differences in temperature sensation, less is known about the sensitivity differences in thermal comfort for the various body regions. In the present study, we examined regional differences in temperature-related sensations with special attention to thermal comfort. Healthy male subjects sitting in an environment of mild heat or cold were locally cooled or warmed with water-perfused stimulators. Areas stimulated were the face, chest, abdomen, and thigh. Temperature sensation and thermal comfort of the stimulated areas were reported by the subjects, as was whole body thermal comfort. During mild heat exposure, facial cooling was most comfortable and facial warming was most uncomfortable. On the other hand, during mild cold exposure, neither warming nor cooling of the face had a major effect. The chest and abdomen had characteristics opposite to those of the face. Local warming of the chest and abdomen did produce a strong comfort sensation during whole body cold exposure. The thermal comfort seen in this study suggests that if given the chance, humans would preferentially cool the head in the heat, and they would maintain the warmth of the trunk areas in the cold. The qualitative differences seen in thermal comfort for the various areas cannot be explained solely by the density or properties of the peripheral thermal receptors and thus must reflect processing mechanisms in the central nervous system.
Graph coloring problems (1995)

Planar Graphs. Graphs on Higher Surfaces. Degrees. Critical Graphs. The Conjectures of Hadwiger and Hajos. Sparse Graphs. Perfect Graphs. Geometric and Combinatorial Graphs. Algorithms. Constructions. Edge Colorings. Orientations and Flows. Chromatic Polynomials. Hypergraphs. Infinite Chromatic Graphs. Miscellaneous Problems. Indexes.
The pharmacokinetics of methotrexate and its 7‐hydroxy metabolite in patients with rheumatoid arthritis. (1993)

1. The pharmacokinetics of MTX and its 7-hydroxy metabolite (7-OHMTX) were investigated in nine patients with rheumatoid arthritis (RA). Each patient received 15 mg MTX i.v., i.m. and p.o. after an overnight fast in a randomized cross-over design. The plasma concentrations of MTX and 7-OHMTX were measured over 7 days and their urinary excretion over 24 h. 2. Plasma concentrations of MTX were described by a triexponential function after i.v. administration, a triexponential function with zero or first order absorption after oral administration, and a biexponential function with zero of first order absorption after i.m. injection. Plasma concentrations of 7-OHMTX were described by a biexponential function after all three routes of administration. The median terminal elimination half-lives of MTX and 7-OHMTX were 55 h and 116 h, respectively. The area under the plasma concentration-time curve (AUC (0,170 h)) of MTX did not differ between i.m. and oral administration indicating similar bioavailability after these routes of administration. The AUC (0,170 h) values of 7-OHMTX after i.v., oral and i.m. administration were similar. Over 80% of MTX was excreted in urine as intact drug and about 3% was excreted as 7-OHMTX during 24 h after drug administration. 3. Plasma concentrations of MTX and 7-OHMTX were measurable at the end of the dose interval in most of the patients and may help to identify non-responders or patients with increased risk of side-effects.