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11.
Wise RG Lujan BJ Schweinhardt P Peskett GD Rogers R Tracey I 《Magnetic resonance imaging》2007,25(6):801-810
BACKGROUND AND PURPOSE: Functional neuroimaging can distinguish components of the pain experience associated with anticipation to pain from those associated with the experience of pain itself. Anticipation to pain is thought to increase the suffering of chronic pain patients. Inappropriate anxiety, of which anticipation is a component, is also a cause of disability. We present a pharmacological functional magnetic resonance imaging (fMRI) study in which we investigate the selective modulation by midazolam of brain activity associated with anticipation to pain compared to pain itself. METHODS: Eight right-handed male volunteers underwent fMRI combined with a thermal pain conditioning paradigm and midazolam (30 mug/kg) or saline administration on different occasions, with order randomized across volunteers. Volunteers learned to associate a colored light with either painful, hot stimulation or nonpainful, warm stimulation to the back of the left hand. RESULTS: Comparison of the period during thermal stimulation (pain-warm) revealed a network of brain activity commonly associated with noxious stimulation, including activities in the anterior cingulate cortex (ACC), the bilateral insular cortices (anterior and posterior), the thalamus, S1, the motor cortex, the brainstem, the prefrontal cortex and the cerebellum. Comparison of the periods preceding thermal stimulation (anticipation to pain-anticipation to warm) revealed activity principally in the ACC, the contralateral anterior insular cortex and the ipsilateral S2/posterior insula. Detected by a region-of-interest analysis, midazolam reduced the activity associated specifically with anticipation to pain while controlling for anticipation to warm. This was most significant in the contralateral anterior insula (P<.05). There were no significant drug effects on the activity associated with pain itself. CONCLUSION: In identifying a pharmacological effect on activity preceding but not during pain, we have successfully demonstrated an fMRI assay that can be used to study the action of anxiolytic agents in a relatively small cohort of humans. 相似文献
12.
13.
Annali di Matematica Pura ed Applicata (1923 -) - We obtain convolution inequalities in Lebesgue and Lorentz spaces with power weights when the functions involved are assumed to be radially... 相似文献
14.
In this paper we solve a boundary value problem in a two-dimensional domain O for a system of equations of Fluid-Poisson type, that is, a viscous approximation to a potential equation for the velocity coupled with an ordinary differential equation along the streamlines for the density and a Poisson equation for the electric field. A particular case of this system is a viscous approximation of transonic flow models. The general case is a model for semiconductors. We show existence of a density ρ, velocity potential φ, and electric potential Φ in the bounded domain O that are C1,α(O¯), C2,α(O¯), and W2,α(O¯) functions, respectively, such that ρ, φ, Φ, the speed |Δφ|, and the electric field E = ΔΦ are uniformly bounded in the viscous parameter. This is a necessary step in the existing programs in order to show existence of a solution for the transonic flow problem. © 1996 John Wiley & Sons, Inc. 相似文献
15.
Michael Reinhardt Andreas Schnhals Dietmar Pfeifer Karl Pfeiffer Irene V. Lampe Hans-Joachim Lorkowski 《先进技术聚合物》1996,7(10):791-796
Dielectric relaxation spectroscopy in the frequency range from 10−2 Hz to 106 Hz and electron spin resonance (ESR) experiments are employed to study the dynamics in chemically and physically crosslinked networks. As examples for physically crosslinked networks ortho- and para-cresol novolacs were investigated. Dielectrically these materials show low-temperature β- and high-temperature α-relaxation. Both relaxation regions differ for both types of novolacs. This is also reflected by the ESR measurements and is discussed in terms of different hydrogen bonds found to be stronger in para-cresol novolac. For the chemically crosslinked poly(triallyl isocyanurate) only a β-peak is found by the dielectric measurements. Also in the ESR experiment the slow motion regime is characterized up to high temperatures. This means that the segmental motion is strongly suppressed by chemical crosslinking. Nevertheless the obtained change in the formal T50G value can be used to characterize the glass transition in highly crosslinked systems by the ESR method. 相似文献
16.
Irene Scheunert 《Chemie in Unserer Zeit》1994,28(2):68-78
Im Prinzip kann fast jede organische Industriechemikalie durch die Mikroorganismen des Bodens abgebaut werden. 相似文献
17.
Rajagopal Karthikeyan Khalaf Abdul Jalil M. Parastesh Fatemeh Moroz Irene Karthikeyan Anitha Jafari Sajad 《Nonlinear dynamics》2019,98(1):477-487
Nonlinear Dynamics - In this paper, the extended Hindmarsh–Rose neuron model, which considers the slow intracellular exchange of calcium ions between its store and the cytoplasm, is studied.... 相似文献
18.
Francesca Di Cristo Anna Valentino Ilenia De Luca Gianfranco Peluso Irene Bonadies Anna Calarco Anna Di Salle 《Molecules (Basel, Switzerland)》2022,27(7)
The management of periodontitis remains a vital clinical challenge due to the interplay between the microorganisms of the dental biofilm and the host inflammatory response leading to a degenerative process in the surrounding tissues. Quercetin (QUE), a natural flavonol found in many foods, including apples, onions and tea, has exhibited prolonged and strong antibiofilm and anti-inflammatory effects both in vitro and in vivo. However, its clinical application is limited by its poor stability and water solubility, as well as its low bioavailability. Thus, in the present study, electrospun polylactic acid (PLA) nanofibers loaded with different amounts (5–10% w/w) of QUE were produced to rapidly respond to the acidic microenvironment typical of periodontal pockets during periodontal disease. This strategy demonstrated that PLA-QUE membranes can act as a drug reservoir releasing high QUE concentrations in the presence of oral bacterial infection (pH < 5.5), and thus limiting Pseudomonas aeruginosa PAO1 and Streptococcus mutans biofilm maturation. In addition, released QUE exerts antioxidant and anti-inflammatory effects on P. gingivalis Lipopolysaccharide (LPS)-stimulated human gingival fibroblast (HGFs). The reported results confirmed that PLA-QUE membranes could inhibit subgingival biofilm maturation while reducing interleukin release, thereby limiting host inflammatory response. Overall, this study provided an effective pH-sensitive drug delivery system as a promising strategy for treating periodontitis. 相似文献
19.
Paloma Begines Sergio Martos Irene Lagunes Ins Maya Jos M. Padrn
scar Lpez Jos G. Fernndez-Bolaos 《Molecules (Basel, Switzerland)》2022,27(4)
Being aware of the enormous biological potential of organoselenium and polyphenolic compounds, we have accomplished the preparation of novel hybrids, combining both pharmacophores in order to obtain new antioxidant and antiproliferative agents. Three different families have been accessed in a straightforward and chemoselective fashion: carbohydrate-containing N-acylisoselenoureas, N-arylisoselenocarbamates and N-arylselenocarbamates. The nature of the organoselenium framework, number and position of phenolic hydroxyl groups and substituents on the aromatic scaffolds afforded valuable structure–activity relationships for the biological assays accomplished: antioxidant properties (antiradical activity, DNA-protective effects, Glutathione peroxidase (GPx) mimicry) and antiproliferative activity. Regarding the antioxidant activity, selenocarbamates 24–27 behaved as excellent mimetics of GPx in the substoichiometric elimination of H2O2 as a Reactive Oxygen Species (ROS) model. Isoselenocarbamates and particularly their selenocarbamate isomers exhibited potent antiproliferative activity against non-small lung cell lines (A549, SW1573) in the low micromolar range, with similar potency to that shown by the chemotherapeutic agent cisplatin (cis-diaminodichloroplatin, CDDP) and occasionally with more potency than etoposide (VP-16). 相似文献
20.
Marina Sicignano Dr. Rosaria Schettini Luisa Sica Giovanni Pierri Prof. Dr. Francesco De Riccardis Prof. Dr. Irene Izzo Dr. Bholanath Maity Dr. Yury Minenkov Prof. Dr. Luigi Cavallo Dr. Giorgio Della Sala 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(29):7131-7141
The first highly enantioselective arylogous Michael reaction (AMR) of 3-unsubstituted phthalides has been described. This phase-transfer methodology, which uses catalytic amounts of KOH/18-crown-6 catalyst in mesitylene in the presence of N,O-bis(trimethylsilyl)acetamide (BSA), gives access to a broad range of 3-monosubstituted phthalides with high levels of syn diastereoselectivity and good yields, starting from 3-unsubstituted derivatives and diverse α,β-unsaturated carbonyl compounds. The reaction also applies to unactivated 3-alkyl phthalides to afford 3,3-dialkyl derivatives. A plausible mechanism has been suggested. DFT analysis of possible transition states gives a rationale of the high syn diastereoselectivity observed and its correlation with the solvent's dielectric constant. 相似文献