Search results for "clam"
showing 10 items of 454 documents
Heat-induced action potential discharges in nociceptive primary sensory neurons of rats.
2009
Although several transducer molecules for noxious stimuli have been identified, little is known about the transformation of the resulting generator currents into action potentials (APs). Therefore we investigated the transformation process for stepped noxious heat stimuli (42-47 degrees C, 3-s duration) into membrane potential changes and subsequent AP discharges using the somata of acutely dissociated small dorsal root ganglion (DRG) neurons (diameteror=32.5 microm) of adult rats as a model for their own peripheral terminals. Three types of heat-induced membrane potential changes were differentiated: type 1, heat-induced AP discharges (approximately 37% of the neurons); type 2, heat-induce…
Second trimester uterine arteries pulsatility index is a function of placental pathology and provides insights on stillbirth aetiology: A multicenter…
2022
Introduction: The aim of this study was to investigate the relationships between maternal vascular malperfusions (MVM) and second trimester uterine arteries pulsatility index (UtA-PI) in cases of stillbirth (SB), compared to live-birth (LB) matched controls. Methods: This was a multicentre, observational, matched case-control study performed at five referral maternity centres over a 4-year period including SB and LB control pregnancies at high-risk for preeclampsia (PE) and/or fetal growth restriction (FGR), matched and stratified for UtA-PI MoM quartiles values of the SB cases. Logistic regression was used to assess the rates of each MVM finding, within each increasing MoM quartile subcate…
Titanium complexes for the formation of nitrogen compounds : synthesis of homoallylamines and amidines
2011
Homoallylic amines are key reagents for the formation of a large number of biologically interesting products. Due to the double bond of their allylic moiety, easily functionalisable, they are commonly used in organic synthesis. This research work deals with the synthesis of homoallylic amines thanks to titanium complexes. In fact, the reductive coupling between of imines and dienes promoted by titanium allows the formation of diastereoisomeric homoallylamines syn and anti. The diastereoselectivity of the reaction is directly affected by the nitrogen substituent. Whether it is benzyl or phenyl, the selectivity will be in favour of syn or anti respectively. Moreover, the addition of a the Lew…
Coexpression of heat-evoked and capsaicin-evoked inward currents in acutely dissociated rat dorsal root ganglion neurons.
1997
Noxious heat is able to activate heat-sensitive nociceptors in the skin very rapidly, but little is known about the mechanisms by which heat is transduced. We used the whole-cell patch-clamp technique to study the effects of noxious heat and capsaicin on freshly dissociated rat dorsal root ganglion neurons in vitro. Using temperatures between 41 degrees C and 53 degrees C, 8 of 19 small neurons (phior = 30 microm) exhibited a heat-evoked inward current. All heat-sensitive neurons tested were also capsaicin-sensitive. Moreover, the heat response tended to be enhanced after capsaicin (360 +/- 150 pA versus 125 +/- 45 pA, P0.1, n = 7). Two of five heat-insensitive neurons were excited by capsa…
[(1,4,8,11-Tetraazacyclotetradeca-1,4,8,11-tetrayl)tetraacetamide-kappa6N1,N4,N8,N11,O1,O8]copper(II) sulfate 4.5-hydrate.
2002
The crystal structure of the title copper(II) complex, [Cu(C(18)H(36)N(8)O(4))]SO(4).4.5H(2)O, formed with the tetraamide cyclam derivative 2-(4,8,11-triscarbamoylmethyl-1,4,8,11-tetraazacyclotetradec-1-yl)acetamide (TETAM), is described. The macrocycle lies on an inversion centre occupied by the hexacoordinated Cu atom. The four macrocyclic tertiary amines form the equatorial plane of an axially Jahn-Teller elongated octahedron. Two O atoms belonging to two diagonally opposite amide groups occupy the apical positions, giving rise to a trans-III stereochemistry, while both the remaining pendant side arms extend outwards from the macrocyclic cavity and are engaged in hydrogen bonds with sulf…
Geostatistical Survey and Amelioration of an Inland Salt Affected Area in the Lake of Texcoco, Mexico
1999
The area formerly occupied by the Texcoco Lake, near Mexico City, was subjected to drainage since the past century, to prevent flooding of the city; however, the progressive desiccation and the geological origin of the area gave place to the appearance of strongly salt and sodium affected soils. Lacking vegetation, these soils are very susceptible to wind erosion, and has been attempted to provide the area with a plant cover, using mostly native species. However, there are extensive areas where the levels of salts and exchangeable sodium percentage (ESP) are so high that the introduction of plants has not been successful; in these places, some kind of amelioration is needed, but since a gen…
State, law and gender studies
2003
La formación del estado y su ordenamiento jurídico se ha realizado por los varones con exclusión de las mujeres, la igualdad entre los hombres y las mujeres no ha sido un principio fundamental del derecho ni del sistema político. El derecho a la igualdad descansa sobre presupuestos de naturaleza cultural y filosófica que tratan al hombre como el sujeto universal y a la mujer como una categoría específica. La teoría feminista del derecho coincide en la crítica de estos presupuestos pero existen grandes diferencias en cuanto se pretende abordar un modelo teórico alternativo para resolver la desigualdad de género-sexo. La aprobación de la Constitución, la adaptación del ordenamiento jurídico a…
Cu2+-cyclam complex functionalised with naphthylmethyl fluorescent signalling subunits as fluorescent chemosensors for sulfate in aqueous environment.
2000
Abstract The fluorescent behaviour of the polyazacycloalkane containing naphthyl groups 1,4,8,11-tetrakis(naphthylmethyl)-1,4,8,11-tetraazacyclotetradecane (L 1 ) and its Cu 2+ complex in the presence of anions are compared in aqueous environment (THF:water 70:30 v/v, 0.1 mol dm −3 tetrabutylammonium perchlorate, 25°C). The emission fluorescent intensity of the L 1 –Cu 2+ system is selectively enhanced in the presence of sulfate at acid pH.
Synthesis, Characterization, and X-ray Crystal Structures of Cyclam Derivatives. 5. Copper(II) Binding Studies of a Pyridine-Strapped 5,12-Dioxocycla…
2004
The copper(II) binding properties of the macrobicyclic diamide 1,9,12,18,22-pentaazatricyclo[7.6.6.1(3,7)]docosa-3,5,7(22)-triene-13,19-dione (L1) have been fully investigated by spectroscopic (IR, UV-vis, EPR, MALDI-TOF MS), X-ray diffraction, potentiometric, electrochemical, and spectroelectrochemical methods. This constrained receptor possesses a hemispherical cavity created by cross-bridging the 1 and 8 positions of trans-dioxocyclam (1,4,8,11-tetraazacyclotetradecane-5,12-dione, L2) with a 2,6-pyridyl strap. Treatment of L1 with a copper salt in methanol produces a red complex of [Cu(L1H(-1))]+ formula in which the copper atom is embedded in a 13-membered ring and coordinated by both a…
Co2+ Translocation in a Terpyridine−Cyclam Ditopic Receptor
2001
The coordination behaviour of the ditopic receptor of 1-[p-(2,2′:6′,2′′-terpyrid-4′-yl)tolyl]-1,4,8,11-tetraazacyclotetradecane (L1) towards Co2+ in acetonitrile/water (70:30, v/v) has been investigated. At acidic pH values, the L1−H+−Co2+ system shows an oxidation wave at 150 mV vs. SCE, characteristic of Co2+ in a bis(terpyridine) environment. Upon addition of OH−, a reduction in the intensity of the wave at 150 mV is observed and a new oxidation wave appears at 1.30 V. This new wave is close to that found for [Co(cyclam)]2+ under similar working conditions. The electrochemical data thus suggest that there is a pH-controlled translocation of the Co2+ ion from the bis(terpyridine) to the c…