851 research outputs found

    Lanthanide(III) complexes of rhodamine-DO3A conjugates as agents for dual-modal imaging

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    Two novel dual-modal MRI/optical probes based on a rhodamine-DO3A conjugate have been prepared. The bis aqua-Gd(III) complex Gd.L1 and mono aqua-Gd(III) complex Gd.L2 behave as dual-modal imaging probes (r1 = 8.5 and 3.8 mM-1s-1 for Gd.L1 and Gd.L2 respectively; λex = 560 nm and λem = 580 nm for both complexes). The rhodamine fragment is pH sensitive and upon lowering of pH an increase in fluorescence intensity is observed as the spirolactam ring opens to give the highly fluorescent form of the molecule. The ligands are bimodal when coordinated to Tb(III) ions, inducing fluorescence from both the lanthanide center and the rhodamine fluorophore, on two independent time-frames. Confocal imaging experiments were carried out to establish the localization of Gd.L2 in HEK cells. Co-localisation with MitoTracker® Green confirmed that Gd.L2 compartmentalizes in the mitochondria. Gd.L2 was also evaluated as an MRI probe for imaging tumors in BALB/c nude mice bearing M21 xenografts. A 36.5% decrease in T1 within the tumor was observed 30 minutes post injection showing that Gd.L2 is preferentially up taken in the tumor. Gd.L2 is the first small molecule MR/fluorescent dual-modal imaging agent to display an off-on pH switch upon its preferential uptake within the more acidic micro-environment of tumor cells

    The Bose–Hubbard model with squeezed dissipation

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    The stationary properties of the Bose–Hubbard model under squeezed dissipation are investigated. The dissipative model does not possess aU (1) symmetry but conserves parity. We find that 〈a j 〉 = 0 always holds, so no symmetry breaking occurs. Without the onsite repulsion, the linear case is known to be critical. At the critical point the system freezes to an EPR state with infinite two mode entanglement. We show here that the correlations are rapidly destroyed whenever the repulsion is switched on. As we increase the latter, the system approaches a thermal state with an effective temperature defined in terms of the squeezing parameter in the dissipators. We characterize this transition by means of a Gutzwiller ansatz and the Gaussian Hartree–Fock–Bogoliubov approximation

    The level of recognition of physical symptoms in patients with a major depression episode in the outpatient psychiatric practice in Puerto Rico: An observational study

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    BACKGROUND: This study was designed to evaluate the psychiatrists' level of recognition of somatic symptoms associated to a major depressive episode (MDE) (DSM-IV-TR criteria) and the impact of those somatic symptoms on the treatment effectiveness. METHODS: This non-interventional study was conducted in 25 medical offices in Puerto Rico from February to December 2003. It had 2 visits separated by 8 weeks. The level of recognition was determined by: the correlation between the physician clinical evaluation and their patients' self-evaluations through different validated instruments using kappa statistics. Chi-square test was used to evaluate the impact of somatic symptoms on treatment antidepressants' effectiveness. RESULTS: All the 145 recruited patients reported the presence of at least one somatic symptom associated with their current MDE. In the two visits covered by the study, a fair agreement between the psychiatrists' and the patients' reports was noted for headache, abdominal pain and upper limb pains (0.4003 ≤ κ ≥ 0.6594). For other painful symptoms and painless somatic symptoms, the Kappa values obtained were non-significant. Slight but significant reductions in depression and painful symptoms severity were observed after 8 weeks of treatment. A proportional relationship between the pain and depression severity was observed (p < 0.0001). CONCLUSION: The study results show that somatic symptoms: are very common in depressed Puerto Rican patients; are significant under-reported by psychiatrists; and have a significant impact on the antidepressant effectiveness

    Lenguaje, representación y tipología en la obra de Ángel Amor Ruibal

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    El objetivo de este trabajo es proporcionar una lectura no historicista, es decir, vinculada en lo posible a la lingüística de los siglos XX-XXI, de la obra del autor gallego Ángel Amor Ruibal (1869-1930). Destacaremos la modernidad de su pensamiento en su visión del lenguaje y la lingüística. Veremos que su concepción del signo en muchos aspectos anticipa y en otros intuye las características que posteriormente le atribuirá Saussure (1916). Además, mostraremos que Amor Ruibal era firmemente partidario de resaltar lo que se conoce en la actualidad como el carácter representacional del lenguaje. De hecho, la línea base de argumentación de este autor coincide, en esencia, con la de Bickerton (1990). Finalmente, resaltaremos las concomitancias entre la visión que tiene de la lingüística el autor gallego y la corriente tipo-lógico-funcional actual (Croft 1993, Moure 2001). Ambas aproximaciones utilizan una metodología histórica, comparativa y funcional basada en una concepción dinámica del lenguaje que integra todo tipo de variación: interlingüística, intralingüística y diacrónica

    Beyond the initial assault: characterizing revictimization in intimate partner violence and its implications for women’s health

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    Recent research has emphasized the importance of addressing specific victim-related factors to reduce victims’ vulnerability and prevent future revictimization experiences. This study aimed to analyze the vulnerability profiles of women who were victims of intimate partner violence, including those who had experienced a single incident of violence and those who had endured revictimization. Participants were 338 women with active judicial protection measures registered in the system of support for victims of gender violence (VioGén) in Madrid, Spain. The analysis considered sociodemographic characteristics, victimization history, perceived triggers of violence, women’s responses and feelings, as well as clinical outcomes linked to revictimization history. The study revealed that many victims faced socioeconomic vulnerability. Furthermore, the findings underscored the intricate link between the likelihood of enduring chronic violence and women’s awareness of early indicators of violence risk, their initial responses to aggression, communication skills, and recurrent behaviors in the context of an established violent dynamic. This study offers valuable insights for law enforcement to identify the risk of revictimization. Furthermore, findings raise awareness about the particularly vulnerable situation of some women to repeated victimization experiences and provide relevant information for clinical interventionThis work was supported by the Ministry of Science, Innovation and Universities of Spain (Grant number: PGC2018-096130-B-I00) and the funding for the predoctoral contract FPI (PRE2019-091184

    High-Frequency Resonant SEPIC Converter With Wide Input and Output Voltage Ranges

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    This paper presents a resonant single-ended-primary-inductor-converter (SEPIC) converter and control method suitable for high frequency (HF) and very high frequency (VHF) dc-dc power conversion. The proposed design provides high efficiency over a wide input and output voltage range, up-and-down voltage conversion, small size, and excellent transient performance. In addition, a resonant gate drive scheme is presented that provides rapid startup and low-loss at HF and VHF frequencies. The converter regulates the output using an ON-OFF control scheme modulating at a fixed frequency (170 kHz). This control method enables fast transient response and efficient light-load operation while providing controlled spectral characteristics of the input and output waveforms. A hysteretic override technique is also introduced which enables the converter to reject load disturbances with a bandwidth much greater than the modulation frequency, limiting output voltage disturbances to within a fixed value. An experimental prototype has been built and evaluated. The prototype converter, built with two commercial vertical MOSFETs, operates at a fixed switching frequency of 20 MHz, with an input voltage range of 3.6-7.2 V, an output voltage range of 3-9 V, and an output power rating of up to 3 W. The converter achieves higher than 80% efficiency across the entire input voltage range at nominal output voltage and maintains good efficiency across the whole operating range

    Lipid Composition and Associated Gene Expression Patterns during Pollen Germination and Pollen Tube Growth in Olive (Olea europaea L.)

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    Pollen lipids are essential for sexual reproduction but our current knowledge regarding lipid dynamics in growing pollen tubes is still very scarce. Here, we report unique lipid composition and associated gene expression patterns during olive pollen germination. Up to 376 genes involved in the biosynthesis of all lipid classes, except suberin, cutin and lipopolysaccharides, are expressed in the olive pollen. The fatty acid profile of the olive pollen is markedly different compared with other plant organs. Triacylglycerol, containing mostly C12-C16 saturated fatty acids, constitutes the bulk of olive pollen lipids. These compounds are partially mobilized, and the released fatty acids enter the β-oxidation pathway to yield acetyl-CoA, which is converted into sugars through the glyoxylate cycle in the course of pollen germination. Our data suggest that fatty acids are synthesized de novo and incorporated into glycerolipids by the “eukaryotic pathway” in elongating pollen tubes. Phosphatidic acid is synthesized de novo in the endomembrane system during pollen germination and seems to have a central role in the pollen tube lipid metabolism. The coordinated action of fatty acid desaturases FAD2-3 and FAD3B might explain the increase of linoleic and alpha-linolenic acids observed in the germinating pollen. A continuous synthesis of triacylglycerol by the action of DGAT1 enzyme, but not PDAT, seems also plausible. All these data allow for a better understanding of the lipid metabolism during the olive reproduction process, which can impact in the future in the increase of olive fruit yield and, therefore, olive oil production

    Depositional and structural controls on a fault-related dolostone formation (Maestrat Basin, E Spain)

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    Fault-related dolomitisation is responsible for the development of numerous hydrocarbon reservoirs hosted in diagenetically-altered carbonates and is therefore critical to hydrocarbon exploration, subsurface storage (i.e. CO2), the formation of associated mineralisation (i.e. MVT-deposits) and for understanding the key controls on subsurface fluid flow. Multiple dolomitised outcrop analogues have been characterised in recent years, but uncertainty still remains as to the controls on dolomitisation in terms of dolostone geobody size and geometries, their distribution and how they impact reservoir quality. Late Tithonian shallow-marine carbonates at Serra Esparreguera in the Maestrat Basin (E. Spain) were partially dolomitised on the seismic scale, resulting in a spectrum of geobodies with varying degrees of spatial connectivity. Dolostone predominantly replaces Polpís Fm wackestones and packstones, and bioclastic grainstones of the Bovalar Fm. Dolostone geobodies transition through vertical stratigraphy from being massive and spatially extensive to localised stratabound bodies as textural heterogeneity increases. Irregular dolostone geometries occur in the Polpís Fm, which is texturally homogenous relative to the overlying Bovalar Fm, cross-cutting bedding in areas with high abundance of faults. Faults occur adjacent to dolostone and constrain its lateral extent across the outcrop. Dolomitisation fronts are typically sharp with morphologies affected by small-scale faults and bedding-parallel stylolites. Dolomitisation occurred under burial conditions and dolostones were later overprinted by phases of calcite and saddle dolomite cementation. The spatial distribution of dolostone is strongly influenced by the depositional heterogeneity and faults, while smaller structures (i.e. metre-scale fractures and stylolites) and bedding surfaces controlled the dolomitisation front geometry. Dolostone geobodies at Serra Esparreguera provide new insights into the structural, depositional and diagenetic controls on dolomitisation at a seismic scale, which can be used as a predictive guide to improve the understanding of carbonate reservoirs with complex paragenetic histories

    Quantitative analysis of stylolite networks in different platform carbonate facies

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    Stylolites are rough surfaces that form by pressure solution, and present variable geometries and spatial distributions. Despite being ubiquitous in carbonate rocks and potentially influencing fluid flow, it is not yet clear how the type and distribution of stylolite networks relate to lithofacies. This study investigates Lower Cretaceous platform carbonates in the Benicàssim area (Maestrat Basin, Spain) to statistically characterise stylolite morphology and stylolite network distributions in a selection of typical shallow-marine carbonate lithofacies, from mudstones to grainstones. Bedding-parallel stylolite networks were sampled in the field to quantify stylolite spacing, wavelength, amplitude, intersection morphology and connectivity. Grain size, sorting and composition were found to be the key lithological variables responsible for the development of rough anastomosing stylolite networks. Poorly-connected stylolites with large vertical spacings were found to be dominant in grain-supported lithofacies, where grains are fine and well sorted. Anastomosing stylolite networks appear well developed in mud-supported lithofacies with poorly-sorted clasts that are both heterogenous in size and composition. Mud-supported facies feature stylolites that are closely spaced, have high amplitudes and intersection densities, and predominantly present suture and sharp-peak type morphologies. Larger grains and poor sorting favour the formation of stylolites with small vertical spacings, low wavelengths and high amplitudes. This statistical analysis approach requires only limited information, such as that from drill core, and can be used to characterise stylolite morphology and distributions in subsurface carbonate reservoirs
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