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1.
J Bodyw Mov Ther ; 36: 228-234, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37949565

RESUMO

INTRODUCTION: Foam Rolling (FR) as a technique of self-massage has become a widely used intervention in clinical and sports practice. It is assumed that FR leads to an increased intramuscular microvascular blood flow (MBF), and therefore is commonly recommended as a warm-up or regeneration method. However, no data validate the effects of FR on MBF. This study aimed to assess whether FR increases intramuscular MBF using contrast-enhanced ultrasound (CEUS). METHODS: Ten healthy athletes performed a standardized FR intervention applied to the lateral thigh (3 sets: 45 s FR, 20 s rest). Intramuscular perfusion was determined by CEUS under resting conditions (t0), immediately (t1), and 30 min (t2) after the intervention. Peak enhancement (PE), wash-in rate (WiR), and wash-in perfusion index (WiPI) were evaluated as quantitative perfusion parameters in vastus lateralis (VL) and intermedius (VI) muscle separately via regions of interest mapping. RESULTS: Immediately after the intervention (t1), perfusion parameters showed a non-significant decrease in VL (p = 0.3; PE: -32.1%, WiPI: -29.6%, WiR: -50.4%) and VI (p = 0.4; PE: -10.3%, WiPI: -6.4%, WiR: -35.6%). A non-significant decrease was found at t2 in VL (p = 0.2; PE: -34%, WiPI -33.9%, WiR -61.2%) and VI (p = 0.2; PE -17.6%, WiPI -13.8%, WiR -43.2%). CONCLUSIONS: The common assumption of intramuscular MBF improvement due to FR could not be confirmed for up to 30 min after the intervention. If an increase in intramuscular metabolism or MBF is intended, we recommend that alternative methods (i.e., traditional warm-up) should be preferred.


Assuntos
Meios de Contraste , Músculo Quadríceps , Humanos , Músculo Quadríceps/diagnóstico por imagem , Microcirculação/fisiologia , Ultrassonografia/métodos
2.
Phys Rev Lett ; 116(3): 033201, 2016 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-26849592

RESUMO

Elastic collisions between initially unpolarized electrons and hydrogenlike atoms are discussed, aiming to analyze the entanglement properties of the correlated final spin system. Explicit spin-dependent interactions are neglected and electron exchange only is taken into account. We show the final spin system to be completely characterized by a single spin correlation parameter depending on scattering angle and energy. Its numerical value identifies the final spins of the collision partners to be either in the separable, entangled, or Bell correlated regions. We emphasize explicit examples for the mixed spin system in order to illustrate the abstract concepts. The analysis of published experimental and numerical data reveals the possibility to create tunable pairs of collision partners with any desired degree of spin entanglement.

3.
J Chem Phys ; 139(3): 034306, 2013 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-23883026

RESUMO

Triple differential cross section measurements for the electron-impact ionization of the highest occupied molecular orbitals of tetrahydropyran and 1,4-dioxane are presented. For each molecule, experimental measurements were performed using the (e,2e) technique in asymmetric coplanar kinematics with an incident electron energy of 250 eV and an ejected electron energy of 20 eV. With the scattered electrons being detected at -5°, the angular distributions of the ejected electrons in the binary and recoil regions were observed. These measurements are compared with calculations performed within the molecular 3-body distorted wave model. Here, reasonable agreement was observed between the theoretical model and the experimental measurements. These measurements are compared with results from a recent study on tetrahydrofuran [D. B. Jones, J. D. Builth-Williams, S. M. Bellm, L. Chiari, C. G. Ning, H. Chaluvadi, B. Lohmann, O. Ingolfsson, D. Madison, and M. J. Brunger, Chem. Phys. Lett. 572, 32 (2013)] in order to evaluate the influence of structure on the dynamics of the ionization process across this series of cyclic ethers.

4.
J Chem Phys ; 136(24): 244301, 2012 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-22755568

RESUMO

Cross section data for electron scattering from DNA are important for modelling radiation damage in biological systems. Triply differential cross sections for the electron impact ionization of the highest occupied outer valence orbital of tetrahydrofurfuryl alcohol, which can be considered as an analogue to the deoxyribose backbone molecule in DNA, have been measured using the (e,2e) technique. The measurements have been performed with coplanar asymmetric kinematics at an incident electron energy of 250 eV, an ejected electron energy of 20 eV, and at scattered electron angles of -5°, -10°, and -15°. Experimental results are compared with corresponding theoretical calculations performed using the molecular 3-body distorted wave model. Some important differences are observed between the experiment and calculations.


Assuntos
DNA/química , Furanos/química , Cinética
5.
J Chem Phys ; 136(2): 024304, 2012 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-22260576

RESUMO

Cross-section data for electron impact induced ionization of bio-molecules are important for modelling the deposition of energy within a biological medium and for gaining knowledge of electron driven processes at the molecular level. Triply differential cross sections have been measured for the electron impact ionization of the outer valence 7b(2) and 10a(1) orbitals of pyrimidine, using the (e, 2e) technique. The measurements have been performed with coplanar asymmetric kinematics, at an incident electron energy of 250 eV and ejected electron energy of 20 eV, for scattered electron angles of -5°, -10°, and -15°. The ejected electron angular range encompasses both the binary and recoil peaks in the triple differential cross section. Corresponding theoretical calculations have been performed using the molecular 3-body distorted wave model and are in reasonably good agreement with the present experiment.


Assuntos
Elétrons , Pirimidinas/química , Teoria Quântica
6.
J Chem Phys ; 133(12): 124302, 2010 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-20886927

RESUMO

Triple differential cross sections for the electron-impact ionization of the outer valence orbital of tetrahydrofuran have been measured using the (e, 2e) technique. The measurements have been performed with coplanar asymmetric kinematics, at an incident electron energy of 250 eV and at an ejected electron energy of 10 eV, over a range of momentum transfers. The experimental results are compared with theoretical calculations carried out using the molecular three-body distorted wave model. The results obtained are important for gaining an understanding of electron driven processes at a molecular level and for modeling energy deposition in living tissue.


Assuntos
DNA/química , Elétrons , Transferência de Energia , Furanos/química , Modelos Biológicos , Fenômenos Biomecânicos , Transferência Linear de Energia
7.
Rev Sci Instrum ; 78(1): 013108, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17503908

RESUMO

We describe new developments aimed to extend the capabilities and the sensitivity of the (e,2e)(e,3e) multicoincidence spectrometer at Orsay University [Duguet et al., Rev. Sci. Instrum. 69, 3524 (1998)]. The spectrometer has been improved by the addition of a third multiangle detection channel for the fast "scattered" electron. The present system is unique in that it is the only system which combines three toroidal analyzers all equipped with position sensitive detectors, thus allowing the triple coincidence detection of the three electrons present in the final state of an electron impact double ionization process. The setup allows measurement of the angular and energy distributions of the ejected electrons over almost the totality of the collision plane as well as that of the scattered electron over a large range of scattering angles in the forward direction. The resulting gain in sensitivity ( approximately 25) has rendered feasible a whole class of experiments which could not be otherwise envisaged. The setup is described with a special emphasis on the new toroidal analyzer, data acquisition hardware, and data analysis procedures. The performances are illustrated by selected results of (e,2e) and (e,3e) experiments on the rare gases.


Assuntos
Elétrons , Espalhamento de Radiação
8.
Phys Rev Lett ; 96(23): 233201, 2006 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-16803377

RESUMO

We have investigated the electron impact single ionization of the hydrogen molecule, with fully determined kinematics. The experimental and theoretical results are compared with He ionization under the same conditions. The results indicate that the ejected electron angular distribution for H(2) is modified due to Young-type interference between ionization amplitudes for scattering from the two centers in the hydrogen molecule. The observable result is a suppression of the backward scattering (recoil) peak compared with the binary peak.

9.
Mol Pharmacol ; 53(6): 1139-48, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9614219

RESUMO

We recently reported that activation of the highly efficient phospholipase C (PLC) stimulatory m3 muscarinic acetylcholine receptor (mAChR) can induce a long-lasting Gi-mediated heterologous potentiation of PLC stimulation in human embryonic kidney (HEK) 293 cells, which was accompanied by an increased cellular level of the PLC substrate phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2]. Here, we examined whether such a potentiated PLC response is also induced by the rather poorly PLC stimulatory m2 mAChR and the endogenously expressed purinergic and lysophosphatidic acid receptors. Pretreatment of m2 mAChR-expressing HEK 293 cells for 2 min with carbachol, followed by agonist washout and measurement of PLC activity >/=40 min later, caused a long-lasting (up to approximately 90 min) heterologous potentiation of receptor- and G protein-mediated PLC stimulation. A similar heterologous potentiation of receptor-mediated PLC stimulation was induced by short term activation of lysophosphatidic acid and purinergic receptors. Either of the three receptor agonists increased the cellular level of PtdIns(4,5)P2 by approximately 50%. The mAChR-induced PLC potentiation was fully prevented by either pertussis toxin or the protein kinase C (PKC) inhibitors staurosporine and Gö 6976, which did not affect acute PLC stimulation. On the other hand, the rise in PtdIns(4,5)P2 was prevented only by combined treatment of HEK 293 cells with pertussis toxin and PKC inhibitors. In conclusion, we demonstrated that activation of poorly PLC stimulatory receptors can also induce a long-lasting Gi-mediated heterologous potentiation of PLC signaling in HEK 293 cells and that this novel PLC regulatory process is under the control of PKC.


Assuntos
Proteínas de Ligação ao GTP/fisiologia , Proteína Quinase C/fisiologia , Receptores Muscarínicos/fisiologia , Fosfolipases Tipo C/metabolismo , Trifosfato de Adenosina/farmacologia , Carbacol/farmacologia , Células Cultivadas , Ativação Enzimática , Humanos , Fosfatos de Inositol/metabolismo , Fosfatidilinositol 4,5-Difosfato/biossíntese
10.
Life Sci ; 60(13-14): 1093-100, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9121352

RESUMO

The role of small molecular weight guanine nucleotide-binding proteins (G proteins) of the Rho family in muscarinic acetylcholine receptor (mAChR) signaling to phospholipase C (PLC) and phospholipase D (PLD) was studied in human embryonic kidney (HEK) cells, stably expressing the human m3 receptor subtype. Evidence for the involvement of Rho proteins in m3 mAChR signaling to both phospholipases is based on findings obtained with Clostridium (C.) difficile toxin B and C. botulinum C3 exoenzyme, both of which specifically, although by different mechanisms, inactivate Rho family G proteins. Toxin B potently inhibited both the mAChR-stimulated PLC and PLD activities in intact cells as well as the stimulation of both phospholipases by the stable GTP analog GTPgammaS in permeabilized cells, the latter effect being mimicked by C3 exoenzyme. In contrast, PLC and PLD activities, measured in the presence of exogenous phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2], a substrate and cofactor for PLC and PLD, respectively, were not altered. These data suggested that the Rho-inactivating toxins inhibit stimulation of PLC and PLD by reducing the cellular level of PtdIns(4,5)P2, which was indeed found with both toxin B and C3 exoenzyme. In agreement with a crucial role of cellular PtdIns(4,5)P2 supply for PLC signaling, we observed that short-term agonist (carbachol) treatment of HEK cells caused a long-lasting increase in PtdIns(4,5)P2 level, accompanied by a potentiation of receptor- and G protein-stimulated inositol phosphate formation. Finally, studies with tyrosine kinase and tyrosine phosphatase inhibitors strongly suggest that PtdIns(4,5)P2 synthesis and mAChR-stimulated PLD activity in HEK cells apparently also involve a tyrosine phosphorylation-dependent mechanism(s). Thus, m3 mAChR signaling to PLC and PLD in HEK cells requires the concerted action of various intracellular components, most notably the complex regulation of PtdIns(4,5)P2 synthesis.


Assuntos
Proteínas de Ligação ao GTP/fisiologia , Fosfolipase D/metabolismo , Receptores Muscarínicos/fisiologia , Fosfolipases Tipo C/metabolismo , Linhagem Celular , Humanos , Peso Molecular , Fosfatidilinositol 4,5-Difosfato/análise , Fosfatidilinositol 4,5-Difosfato/fisiologia
13.
Infusionstherapie ; 17(2): 84-8, 1990 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-2113039

RESUMO

A total of 20 patients of both sexes received total parenteral nutrition with an all-in-one solution (excluding fat). All patients underwent a medium-sized surgical intervention. The solution was applied throughout 4 postoperative days in a medium dosage of 30 ml/kg B.w./day. Additional electrolyte solutions (200-500 ml/day) were allowed, to substitute fluid losses. Routine laboratory parameters remained in hemostasis; even blood sugar was stabilized between 120 and 150 mg% (x) without insulin. The authors conclude that short-term parenteral nutrition using this all-in-one solution exclusively could achieve hemostasis in clinically relevant parameters. No side effects were detected.


Assuntos
Nutrição Parenteral Total/métodos , Cuidados Pós-Operatórios/métodos , Adulto , Idoso , Aminoácidos/administração & dosagem , Ensaios Clínicos como Assunto , Eletrólitos/administração & dosagem , Emulsões Gordurosas Intravenosas/administração & dosagem , Feminino , Gastroenteropatias/cirurgia , Solução Hipertônica de Glucose/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/cirurgia , Necessidades Nutricionais , Estudos Prospectivos
14.
Phys Rev A Gen Phys ; 34(2): 1561-1563, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9897419
15.
Arch Orthop Trauma Surg (1978) ; 103(2): 83-4, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6477077

RESUMO

Stress roentgenograms in 25 probands were performed to evaluate the stability of the normal shoulder joint. The shoulder was remarkably stable, the average ventral subluxation being 0.8 mm, the dorsal subluxation 0.2 mm.


Assuntos
Instabilidade Articular/diagnóstico por imagem , Articulação do Ombro/diagnóstico por imagem , Estresse Mecânico , Adulto , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/fisiopatologia , Instabilidade Articular/fisiopatologia , Radiografia , Articulação do Ombro/fisiologia , Articulação do Ombro/fisiopatologia
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