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<title>Ciencias Experimentales</title>
<link>http://hdl.handle.net/10366/4055</link>
<description/>
<pubDate>Mon, 25 May 2026 17:39:18 GMT</pubDate>
<dc:date>2026-05-25T17:39:18Z</dc:date>
<item>
<title>Kinematics of Burial Remagnetizations in Fold-and-Thrust Belts: A Case Study From the South Pyrenean Foreland Basin (NE Spain)</title>
<link>http://hdl.handle.net/10366/171385</link>
<description>[EN]This study investigates two burial‐related remagnetizations in the Jaca–Pamplona foreland basin (Southern Pyrenees): one with dual polarity and a positive reversals test, and another with only reverse polarity. These components, labeled C3 and C4 based on their mean unblocking temperatures, were identified from a paleomagnetic analysis of 142 sites in Eocene turbidites of the Hecho Group. Component C3 shows unblocking temperatures of 250°C–350°C, systematic reverse polarity, and a predominantly post‐folding timing.&#13;
Component C4 exhibits unblocking temperatures of 250°C–550°C, dual polarity and a mainly syn‐to postfolding acquisition. The spatial distribution of C4 polarity defines WNW–ESE bands parallel to structures and younging southward. The acquisition of C4 is interpreted as a chemical remagnetization triggered by progressive burial driven by combined sedimentary and tectonic loading that increased temperatures (up to ∼250°C in the deeper northern sectors, according to previous paleotemperature studies). This thermal evolution&#13;
promoted authigenic, stable single‐domain magnetite growth, beginning during the Lutetian (chron C20) and probably ending in the Rupelian (chrons C11‐C10) as uplift and exhumation progressed. In contrast, the reverse polarity and post‐folding behavior of component C3 suggest a mixed origin involving both chemical remagnetization and a thermoviscous overprint during the long chron C12r (Rupelian), contemporaneous with the youngest reverse C4 band and preceding the final exhumation of the basin. These findings highlight the complex interplay among tectonics, sedimentation, and chemical remagnetization processes in the South Pyrenean foreland, providing new insight into the timing and kinetics of remagnetization in fold‐and‐thrust belts.
</description>
<pubDate>Thu, 01 Jan 2026 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171385</guid>
<dc:date>2026-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>Magnetic fabrics and paleomagnetism of continental mudrocks: Implications for unravelling the tectonic evolution of the South Pyrenean Zone (NE Spain)</title>
<link>http://hdl.handle.net/10366/171384</link>
<description>[EN]The anisotropy of the magnetic susceptibility (AMS) in mudrocks has been widely used to study orogenic belts due to their sensitivity to strain, while paleomagnetism remains the most effective method to quantify vertical axis rotations (VARs) resulting from the accommodation of along-strike variations in shortening. However, AMS can be also eventually used as a passive marker to detect VARs and the integration of both techniques offers a powerful approach to understand the tectonic evolution of fold-and-thrusts-belts. In this work, a combined AMS and paleomagnetic study along a stratigraphic section of continental rocks from the Campodarbe Formation in the Jaca-Pamplona Basin, southern Pyrenees, was carried out. This stratigraphic section (Martes section) records the tectonic evolution of this part of the basin from Priabonian to Rupelian times. The magnetic fabrics show the imprint of early stages of deformation, characterized by dominantly oblate ellipsoids and WNW-ESE horizontal magnetic lineations (axes of maximum magnetic susceptibility kmax), parallel to bedding and the main regional structures. In the lower part of the section, kmax axes trend around 290º, gradually rotating to 270º towards the top. The AMS is interpreted as locked under the imprint of the layer parallel shortening (LPS) associated to the activity of the basement thrusts in the northern Jaca-Pamplona Basin. On the other hand, paleomagnetic data indicate clockwise VARs of 6º to 12º in the lower part of the section, and a counterclockwise rotation of 7º to 14º in the upper part. These differential rotations could result from lateral changes in the Biniés basement thrust or the Jaca thrust system that were active during Oligocene&#13;
times. Both techniques record a net rotation of ca. 25º between the lower and upper part of the section, which support the interpretation that early-locked AMS behaves as a passive marker and validates its use for detecting and quantifying VARs.
</description>
<pubDate>Thu, 01 Jan 2026 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171384</guid>
<dc:date>2026-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>Controlling human activities as confounding variable in road studies</title>
<link>http://hdl.handle.net/10366/171311</link>
<description>[EN]Roads cause disturbances to wildlife from the beginning of their construction and once the road is in operation, people usually make use of the habitats, reducing their quality. To this are added the effects caused by light and noise from vehicles. These propagate through the land adjacent to the road causing changes in the fauna’s use of the habitat. This led us to ask ourselves what attributes inherent to the road and terrain influence the vertebrate fauna and what factors associated with human activities can be considered as confounding variables for the results interpretation? The study was conducted in proximity of the 40D highway in Mexico. Three paired areas were selected where signs of wildlife presence were recorded during spring and fall from 2018 to 2020 and these data were used as response variable (2108 records of 49 species). We used as explanatory variables the inherent&#13;
characteristics of the natural terrain and road (e.g., height difference between road and habitat, distance from road), as well as those related to human presence in the habitat (e.g., distance to nearest town). GLM’s were adjusted to determine the influence of these on our response variable. We found that the inherent variables of the road and terrain have a significant influence on the number of faunal of hunting interest traces found (p = 0.018, r2 = 23.09). The method used allowed us to identify and distinguish the influence that human activities exert on the fauna within the road’s influence zone. The differential way in which organisms respond to human presence and activity makes it difficult to isolate this effect from the one we wish to evaluate, such as that of the road. Therefore, it is suggested that the variables used in this study be used as a control measure of this effect in the work carried out in proximity of roads.
</description>
<pubDate>Mon, 18 Jul 2022 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171311</guid>
<dc:date>2022-07-18T00:00:00Z</dc:date>
</item>
<item>
<title>COVID-19 related travel restrictions prevented numerous wildlife deaths on roads: A comparative analysis of results from 11 countries</title>
<link>http://hdl.handle.net/10366/171310</link>
<description>[EN]Millions of wild animals are killed annually on roads worldwide. During spring 2020, the volume of road traffic was reduced globally as a consequence of the COVID-19 pandemic. We gathered data on wildlife-vehicle collisions (WVC) from Czechia, Estonia, Finland, Hungary, Israel, Norway, Slovenia, Spain, Sweden, and for Scotland and England within the United Kingdom. In all studied countries WVC statistics tend to be dominated by large mammals (various deer species and wild boar), while information on smaller mammals as well as birds are less well recorded. The expected number of WVC for 2020 was predicted on the basis of 2015–2019 WVC time series representing expected WVC numbers under normal traffic conditions. Then, the forecasted and reported WVC data were compared.&#13;
The results indicate varying levels of WVC decrease between countries during the COVID-19 related traffic flow reduction (CRTR). While no significant change was determined in Sweden, where the state-wide response to COVID-19 was the least intensive, a decrease as marked as 37.4% was identified in Estonia. The greatest WVC decrease, more than 40%, was determined during the first weeks of CRTR for Estonia, Spain, Israel, and Czechia.&#13;
Measures taken during spring 2020 allowed the survival of large numbers of wild animals which would have been killed under normal traffic conditions. The significant effects of even just a few weeks of reduced traffic, help to highlight the negative impacts of roads on wildlife mortality and the need to boost global efforts of wildlife conservation, including systematic gathering of roadkill data.
</description>
<pubDate>Thu, 01 Apr 2021 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171310</guid>
<dc:date>2021-04-01T00:00:00Z</dc:date>
</item>
<item>
<title>Effect of Protected Areas on Human Populations in the Context of Colombian Armed Conflict, 2005–2018</title>
<link>http://hdl.handle.net/10366/171309</link>
<description>[EN]It is widely recognised that conservation policies in protected areas must also favour the development and viability of human populations. Although much research has focused on economic consequences, understanding the real impact of conservation on local populations requires a more holistic standpoint. Using quasi-experimental matching methods and a diachronic perspective, the biodemographic and socio-economic effects of Colombia’s National Natural Parks (NNPs) were evaluated (all in a context of internal conflict and post-conflict). The analyses were made for the set of NNPs and then grouped into four natural regions (Andes, Caribbean, Amazon-Orinoquía and Pacific) and two conflict intensities. Differences were found mainly for NNPs with low-intensity conflict, but only for biodemographic variables, not for socio-economic ones. Starting from a situation of disadvantage, a relative improvement in the conditions of the NNP municipalities was observed throughout the 13-year period in relation to the control group. Results should be taken with caution due to the conflict situation, but the lack of correlation between biodemographic and socio-economic aspects highlights the need to include more complex approaches in protected area management policies.
</description>
<pubDate>Fri, 25 Dec 2020 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171309</guid>
<dc:date>2020-12-25T00:00:00Z</dc:date>
</item>
<item>
<title>Connectivity Predicts Presence but Not Population Density in the Habitat-Specific Mountain Lizard Iberolacerta martinezricai</title>
<link>http://hdl.handle.net/10366/171308</link>
<description>[EN]The Batuecan lizard Iberolacerta martinezricai is a critically endangered species due to its significantly reduced distribution, which is restricted to the scree slopes (SS) of a few mountain peaks within the Batuecas-Sierra de Francia Natural Park (western Spain). Given its high specialisation in this type of discontinuous habitat, the long-term conservation of the species requires maintaining the connectivity between populations. This study analyses the contribution of connectivity, as well as other patch-related factors, in the distribution and density patterns of the species. With this aim, 67 SS were sampled by line transects from May to October 2018. Each SS was characterised using variables indicative of the microhabitat conditions for the lizard. Inter-SS connectivity was quantified using graph theory for seven distances. Generalised linear models (GLMs) were performed for both presence and density. Model results showed that while connectivity was a relevant factor in the presence of lizards, density only involved patch-related variables. Discrepancies probably occurred because the factors influencing presence operate on a wider scale than those of abundance. In view of the results, the best-connected SS, but also those where the lizard is most abundant and from which more dispersed individuals are likely to depart, seem to be the essential patches in any conservation strategy. The results may also be relevant to other species with habitat-specific requirements.
</description>
<pubDate>Tue, 02 Mar 2021 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171308</guid>
<dc:date>2021-03-02T00:00:00Z</dc:date>
</item>
<item>
<title>Use of rock tablet method to measure rock weathering and landscape denudation</title>
<link>http://hdl.handle.net/10366/171232</link>
<description>[EN]Rock weathering is a key component of the rock cycle that transforms rocks in sediments, soils and/or dissolves minerals to ions, and plays an important role in landforms development and landscape evolution. The quantification of weathering is often challenging due to the impact of measuring techniques on the rock itself and/or the assumptions required to perform the calculations. Among different methods used to quantify rock weathering, rock tablet method is one of the most widely used. The rock tablet method consists of cutting rock samples in a shape that allows precise calculation of their volume and surface. These rock pieces, often named tablets when they are flat, are dried, precisely weighed and exposed to the natural environment for certain amount of time. After retrieval, the same laboratory procedure is repeated, and from the weight loss, the weathering rate is calculated. When the density of the rock is known and it is reasonable to assume that the lost material is removed from the ground surface, the weight loss can be used to calculate denudation rates. This is the case in karst regions, where rock tablets are one of the most commonly used methods to calculate denudation. This simple and versatile method requires only a limited amount of laboratory equipment to be implemented which makes it very popular. However, experimental design, preparation of samples and calculations are not homogeneous among researchers, sometimes making the results of this method challenging to be evaluated and compared. In this paper we describe the rock tablet method, include its historical overview, review the most significant studies that have used this technique, highlight its limitations, introduce correction factors to minimize some of those limitations, and provide good practice recommendations to help other researchers to obtain comparable results around the world.
</description>
<pubDate>Fri, 01 Jan 2021 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171232</guid>
<dc:date>2021-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>ISODRIP, a model to transfer the δ18O signal of precipitation to drip water — Implementation of the model for Eagle Cave (central Spain)</title>
<link>http://hdl.handle.net/10366/171231</link>
<description>[EN]The isotope signature of cave waters provides an excellent opportunity to better understand the recharge in karst regions and the complexity of drainage systems in the vadose zone. We have developed a cave isotope hydrological model (ISODRIP) that requires entering basic hydrometeorological information and a precipitation δ18O record to simulate the discharge and δ18O signals of different drip sites. The model includes four different modules to simulate various flow route regimes: continuous and discontinuous drips under diffuse or preferential flows. We use precipitation and cave water δ18O records that were obtained in Eagle Cave (central Spain) during a 5-year period to test our model and to better understand the dynamics of karst aquifers. Eagle Cave waters do not record evaporation. The δ18O signals do not have seasonality, although they record intra-annual and inter-annual variability. Additionally, cave water δ18O signal falls within the range of the annual average weighted isotope composition of precipitation. Well-mixed cave waters, that characterize diffuse flows, record 1‰ δ18O variability, whereas partially-mixed waters, that flow along preferential drainage routes, have up to 3‰ δ18O variability. The results suggest that precipitation takes on average 15 months to reach the cave through the diffuse flow network, whereas under preferential flow the transit time is highly variable depending on the previous condition of the system. ISODRIP includes a soil layer above the vadose zone that controls large recharge events, together with direct recharge components that bypass the soil layer enabling at least some recharge all year round. Thus, the simulations reproduce the observed lack of seasonal bias in the cave water δ18O composition in relation to the average weighted isotope composition of precipitation. This research highlights the importance of understanding recharge dynamics and the configuration of particular drips sites to properly interpret speleothem δ18O records.
</description>
<pubDate>Fri, 01 Jan 2021 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171231</guid>
<dc:date>2021-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>Temperature as a tracer of hydrological dynamics in an anchialine cave system with a submarine spring</title>
<link>http://hdl.handle.net/10366/171224</link>
<description>[EN]Although temperature is a nonconservative tracer, it often provides useful information to understand hydrological processes. This study explores the potential of temperature to characterize the hydrological dynamics of a submarine spring and its coastal karst aquifer in Krka Estuary (Croatia). The estuary is well stratified and its water column has a clear thermocline. A network of loggers was designed to monitor the temperature along vertical profiles in the estuary and the coastal aquifer, taking advantage of an anchialine cave that enabled access to the subterranean estuary. The location of the thermocline in the groundwater, which defines the upper boundary of the saline intrusion, depends on (1) the recharge of the aquifer via infiltration of precipitation, (2) the evolution of the thermocline in the estuary, and (3) the tidal oscillations. The sources of water flowing though the anchialine cave were identified: brackish water from the estuary above the thermocline, saline water from the estuary below the thermocline, and freshwater from infiltrated precipitation. A conceptual model is described that characterizes the hydrological dynamics of this coastal aquifer and its interactions with the estuary. Thus, at least for some hydrological settings, temperature is a valid tracer to characterize the main hydrological processes. The measurement of temperature is inexpensive compared to other (conservative) tracers. Therefore, for those hydrological settings that have water masses with distinct temperatures, the use of temperature as a tracer to establish conceptual models of the hydrological dynamics is encouraged.
</description>
<pubDate>Mon, 01 Jan 2018 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171224</guid>
<dc:date>2018-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>Plasticity, Mineralogy, and WRB Classification of Some Typical Clay Soils along the Two Major Rivers in Croatia</title>
<link>http://hdl.handle.net/10366/171223</link>
<description>[EN]Quantification of soil plasticity is usually based on Atterberg limits or indices, which are then used for engineering and agricultural purposes on clay soils. Because these limits/indices are seldom analyzed during routine soil surveys, they are sometimes estimated from available soil properties using pedotransfer functions (PTFs). Main aim of this study was to test if two robust PTFs, previously created by other authors for other soils/areas, may be used for predicting plasticity of typical clay soils on fluvial deposits in Croatia. We analyzed mineralogy, plasticity, and related physicochemical properties of four representative soil profiles&#13;
along Sava and Drava, two longest Croatian rivers. Particle size distribution patterns pointed to more uniform sedimentation along Sava, compared to Drava. Also, more clay was found within Sava profiles. Soil texture was finer farther away from the sources of both rivers. Soil cation exchange capacity (CEC) was almost fully positively correlated to clay content. On the other hand, Corg content showed no correlation to CEC. This is attributed to the significant presence of smectite across all studied soils. Clay was recognized as the main factor influencing soil plasticity. When compared to the measured values, the predicted values of plasticity index and liquid limit were heavily underestimated. Hence, region-specific PTFs should be developed for more accurate prediction of plasticity in these soils. According to the WRB-2015, the soils were classified as Eutric Reductigleyic Stagnic Gleysols (Clayic, Humic, Protovertic). Because soils were not dry during field description, shrink-swell cracks were not prominent, and therefore soils were not classified as Vertisols. We suggest that field criteria for classification of Vertisols should not depend on actual soil moisture. Instead, plastic limits/ indices could be used.
</description>
<pubDate>Wed, 01 Jan 2020 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171223</guid>
<dc:date>2020-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>Long-term denudation rate of karstic North Dalmatian Plain (Croatia) calculated from 36Cl cosmogenic nuclides</title>
<link>http://hdl.handle.net/10366/171220</link>
<description>[EN]The development of a karst landscape results from complex interactions between lithology, climate, hydrology, soil, vegetation and tectonics. Weathering and erosion of carbonate rocks leads to denudation of karst landscapes. As dissolution of carbonate rocks is often considered to be the main process governing carbonate weathering, other processes are often overlooked. Here we present research done in the North Dalmatian Plain, a carbonate erosive surface located in the Dinaric karst region. Although the study site is composed of two different carbonate lithologies having different weathering style, there is no evident lithological impact on the topography of the erosive surface. Analyses of 36Cl concentration were performed in ten proximal bedrock samples from both lithologies and resulted in long-term denudation rates ranging from 14.7 to 22.8 m/Ma. Since no statistical significance&#13;
was found between samples from different lithologies (all samples belong to a single normal population) and they have the same geomorphological context and climate features, variable denudation rates are attributed to local (sample specific) differences. In the study site there are no large outstanding rock residuals or patches with deep soil profiles. Thus, to maintain the levelled erosive surface, local differential denudation rates have to vary with time. We hypothesize that lichens and pedogenic carbonates have a significant role in modulating local differences in denudation rates. Our study shows that even at outcrop scale those differences can be significant, and the study of sample populations is preferred to single or limited number of analyses. Thus, the longterm denudation rate of the North Dalmatian Plain, including its local variability is 18.91±0.81 m/Ma. Despite classical studies on karst terrains assume that dissolution is the main process responsible for development of these landscapes, our research highlights the importance of physical weathering in combination with dissolution of carbonates as main controls on the denudation of karst landscapes.
</description>
<pubDate>Sat, 01 Jan 2022 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171220</guid>
<dc:date>2022-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>Investigation of short-term denudation rates using the rock tablet method in Northern Velebit National Park (Croatia)</title>
<link>http://hdl.handle.net/10366/171181</link>
<description>[EN]The formation of karst landscapes is the result of a series of processes, whereby rock weathering and denudation play important roles. Soluble carbonate rocks are chemically weathered (dissolved) on the surface or under soil cover resulting in the formation of different karst morphologies and controlling surface denudation.&#13;
The Dinaric karst area is the type-site for numerous karst features and phenomena, but studies on carbonate weathering in this region are still scarce, especially in the mountainous regions. To better understand the formation of Dinaric karst mountainous landscapes, we studied denudation rates at the northern part of Velebit Mountain using the rock tablet method. Denudation was measured using rock tablets consisting of local lithologies and “standard rock tablets” exposed to the natural environment at the surface, but also buried in the soil. Furthermore, rock tablets were placed in three different settings (open slope, small clearing, bottom of a doline) to evaluate the local factors impacting the denudation rate. The results of this study showed that the denudation rate is highly dependent on local factors and lithology, and that local rock tablets from different lithologies should be used to determine the actual denudation rate.
</description>
<pubDate>Mon, 01 Jan 2024 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171181</guid>
<dc:date>2024-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>La traducción médico-farmacéutica en los Grados de Traducción e Interpretación en las universidades españolas, la opinión de los profesores</title>
<link>http://hdl.handle.net/10366/171091</link>
<description>[ES]La traducción médico-farmacéutica como rama&#13;
de especialidad se empieza a impartir desde nivel de grado en&#13;
asignaturas como Traducción Científico-Técnica, Traducción&#13;
Biosanitaria o como parte del temario de asignaturas de traducción general o traducción especializada. En nuestra investigación, hemos querido obtener una foto fija de su presencia&#13;
en las universidades españolas y recabar la opinión de los profesores que la imparten para conocer en mayor profundidad&#13;
cómo se aborda su enseñanza, así como su pertinencia en los&#13;
estudios de Traducción e Interpretación.
</description>
<pubDate>Sat, 01 Jan 2022 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171091</guid>
<dc:date>2022-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>Effect of binary and ternary polyvinylpyrrolidone and/or hydroxypropyl-β-cyclodextrin complexes on the photochemical and photosensitizing properties of Naproxen</title>
<link>http://hdl.handle.net/10366/171081</link>
<description>[EN]The effect of the polyvinylpyrrolidone and/or hydroxypropyl-b-cyclodextrin on the photolability of aqueous solutions of the antiinflammatory&#13;
drug Naproxen was studied. Kinetic studies revealed that the presence of all of these additives reduced drug photodegradation.&#13;
In all cases, the presence of the different additives elicited a change in the photomixture composition, being the&#13;
alcoholic derivative the major photoproduct formed. Nevertheless, the change in the efficiency of the process and the amount of&#13;
the photoproducts formed in the different systems were not related with the biodamage produced by the drug. In this sense, the&#13;
presence of free Naproxen clearly sensitized the photoperoxidation of linoleic acid. The photosensitizing effect decreased as the&#13;
PVP concentration increased. Different protection provides the binary (Naproxen:HP-b-CD) and ternary (Naproxen:HP-b-&#13;
CD:PVP) complexes. The binary complex formation had not effect on the prevention of photooxidation of linoleic acid sensitized&#13;
by the drug, whereas the ternary complex formation supresses the drug effect. The different behaviour observed with b-CD and HPb-&#13;
CD and the structural differences of both cyclodextrins seem to indicate that in the case of the HP-b-CD the linoleic binds with the&#13;
CD and takes contact with the drug. These results confirm that in these systems the prevention of biodamage would be due to a&#13;
decrease in the contact between the short-lived species generated during Naproxen photodegradation and biological structures,&#13;
rather than due to the nature or amount of the photoproducts. In addition, the ability of the complex to interact with the biological&#13;
structure depends on the structure of both interacting species.
</description>
<pubDate>Thu, 01 Jan 2004 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171081</guid>
<dc:date>2004-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>Naproxen: Hydroxypropyl-β-cyclodextrin: Polyvinylpyrrolidone ternary complex formation</title>
<link>http://hdl.handle.net/10366/171080</link>
<description>[EN]The aim of the present study was to investigate the effect of the presence of the water-soluble polymer polyvinylpyrrolidone&#13;
(PVP) MW = 24000 g/mol, on the complexation of the phototoxic anti-inflammatory drug naproxen, in its sodium salt&#13;
form, with hydroxypropil-β-cyclodextrin (HP-β-CD). The data show that the polymer interacts with the free naproxen and&#13;
with the naproxen:HP-β-CD inclusion complex. The presence of different proportions of PVP, in the 0–1%(w/w) range&#13;
systematically increased the Kapp of the naproxen:HP-β-CDinclusion complex formation. The cause of this increase is that&#13;
the polymer interacts with the HP-β-CD with a binding constant of K2 = 29000± 53M−1; and with the naproxen:HP-β-CD&#13;
inclusion complex, to give a ternary complex naproxen:HP-β-CD:PVP. The binding constant of this process was K3 = 5350&#13;
± 1 M−1. NMR data revealed that in the ternary system, PVP is outside of the cyclodextrin, and therefore must be wholly&#13;
or partially recovering the naproxen:HP-β-CD inclusion complex.
</description>
<pubDate>Thu, 01 Jan 2004 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171080</guid>
<dc:date>2004-01-01T00:00:00Z</dc:date>
</item>
<item>
<title>Hydrogen bonding in a non-steroidal anti-inflammatory drug—Naproxen</title>
<link>http://hdl.handle.net/10366/171052</link>
<description>[EN]Photophysical properties of a non-steroidal anti-inflammatory drug, Naproxen (6-methoxy a-methyl-2-naphthalene acetic acid sodium&#13;
salt), were investigated in solvents of different polarity, hydrogen donor ability and also in cyclodextrins. The results indicate that in all cases&#13;
the emitting state is the ~I~ singlet. In alcoholic solvents, an intermolecular hydrogen bond is responsible for the observed photophysical&#13;
behaviour of the probe whereas in non-protic solvents (polar and weakly polar) an intramolecular hydrogen bond type is postulated to&#13;
rationalize the data found. In water, the non-radiative rate constant has a value similar to those found in aqueous solutions of a- and/3-&#13;
cyclodextrins where the probe form complexes. The behaviour in water is explained by a water-structure enforced hydrophobic effect.&#13;
The spectroscopic results are interpreted on the basis of a multiple-parameter model that considers specific solute-solvent interactions.&#13;
These were also observed in the ground state and detected by Fourier transform infrared spectroscopy.&#13;
Molecular mechanics (MM) and molecular orbital (AM1) calculations also support the existence of two conformations (rotamers) in&#13;
Naproxen with non-equivalent intramolecular hydrogen bond-like formation.
</description>
<pubDate>Sun, 01 Jan 1995 00:00:00 GMT</pubDate>
<guid isPermaLink="false">http://hdl.handle.net/10366/171052</guid>
<dc:date>1995-01-01T00:00:00Z</dc:date>
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