467 research outputs found
THE OPTICAL PROPERTIES OF Pr3+ EMBEDDED IN THE RARE EARTH BOROGERMANATE MATRICES: REBGeO5
The luminescent properties of the trivalent praseodymium ion in the trigonal borogermanate matrice PrBGeO5 have been analysed. The energy level schemes are deduced from the absorption and emission spectra and reproduced with 14 crystal field parameters (cfps) according to the local point symmetry occupied by the rare earth element in the matrix.The luminescent properties of the trivalent praseodymium ion in the trigonal borogermanate matrice PrBGeO5 have been analysed. The energy level schemes are deduced from the absorption and emission spectra and reproduced with 14 crystal field parameters (cfps) according to the local point symmetry occupied by the rare earth element in the matrix
Effects of human pharmaceuticals on cytotoxicity, EROD activity and ROS production in fish hepatocytes.
Pharmaceuticals are found in the aquatic environment but their potential effects on non-target species like fish remain unknown. This in vitro study is a first approach in the toxicity assessment of human drugs on fish. Nine pharmaceuticals were tested on two fish hepatocyte models: primary cultures of rainbow trout hepatocytes (PRTH) and PLHC-1 fish cell line. Cell viability, interaction with cytochrome P450 1A (CYP1A) enzyme and oxidative stress were assessed by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrasodium bromide tetrazolium (MTT), 7-ethoxyresorufin-o-deethylase (EROD) and dichlorofluorescein (DCFH-DA) assays, respectively. The tested drugs were clofibrate (CF), fenofibrate (FF), carbamazepine (CBZ), fluoxetine (FX), diclofenac (DiCF), propranolol (POH), sulfamethoxazole (SFX), amoxicillin (AMX) and gadolinium chloride (GdCl(3)). All substances were cytotoxic, except AMX at concentration up to 500 microM. The calculated MTT EC(50) values ranged from 2 microM (CF) to 651 microM (CBZ) in PLHC-1, and from 53 microM (FF) to 962 microM (GdCl(3)) in PRTH. CF, FF, and FX were the most cytotoxic drugs and induced oxidative stress before being cytotoxic. Compared to hepatocytes from human and dog, fish hepatocytes seemed to be more susceptible to the peroxisome proliferators (PPs) CF and FF. In PLHC-1 cells none of the tested drugs induced the EROD activity whereas POH appeared as a weak EROD inducer in PRTH. Moreover, in PRTH, SFX, DiCF, CBZ and to a lesser extend, FF and CF inhibited the basal EROD activity at clearly sublethal concentrations which may be of concern at the biological and chemical levels in a multipollution context
Smoothened receptor signaling regulates the developmental shift of GABA polarity in rat somatosensory cortex.
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordSonic Hedgehog (Shh) and its patched-smoothened receptor complex control a variety of functions in the developing central nervous system such as neural cell proliferation and differentiation. Recently, Shh signaling components have been found to be expressed at the synaptic level in the postnatal brain, suggesting a potential role in the regulation of synaptic transmission. Using in utero electroporation of constitutively active and negative-phenotype forms of the Shh signal transducer smoothened (Smo), we studied the role of Smo signaling in the development and maturation of GABAergic transmission in the somatosensory cortex. Our results show that enhancing Smo activity during development accelerates the shift from depolarizing to hyperpolarizing GABA in dependence on functional expression of potassium-chloride cotransporter type 2 (KCC2). On the other hand, blocking Smo activity maintains GABA response in a depolarizing state in mature cortical neurons resulting in altered chloride homeostasis and increased seizure susceptibility. This study reveals an unexpected function of Smo signaling on the regulation of chloride homeostasis through the control of KCC2 cell surface stability and on the timing of the GABA inhibitory/excitatory shift in brain maturation
A stable fish reporter cell line to study estrogen receptor transactivation by environmental (xeno)estrogens.
International audienceCross-species differences between human and fish estrogen receptor (ER) binding by environmental chemicals have been reported. To study ER transactivation in a fish cellular context, we stably co-transfected the PLHC-1 fish hepatoma cell line with a rainbow trout estrogen receptor (rtER) and the luciferase reporter gene driven by an estrogen response element (ERE). This new cell model, called PELN-rtER (for PLHC-1-ERE-Luciferase-Neomycin), responded to 17beta-estradiol (E2) in a both concentration- and temperature-dependent manner, as well as to environmental ER ligands from different chemical classes: natural and synthetic estrogens, zearalenone metabolites, genistein, alkyphenoles and benzophenone derivatives. The comparison with other in vitro models, i.e. human reporter cell lines (HELN-rtER, MELN) and vitellogenin induction in primary cultures of rainbow trout hepatocytes, showed an overall higher sensitivity of the human cells for a majority of ligands, except for benzophenone derivatives which were active at similar or lower concentrations in fish cells, suggesting species-specificity for these substances. Correlation analyses suggest that the fish cell line is closer to the trout hepatocyte than to the human cell context, and could serve as a relevant mechanistic tool to study ER activation in fish hepatic cellular context
Clinical presentation, management and outcomes in the Acute Heart Failure Global Survey of Standard Treatment (ALARM-HF)
Purpose: We performed a survey on acute heart failure (AHF) in nine countries in four continents. We aimed to describe characteristics and management of AHF among various countries, to compare patients with de novo AHF versus patients with a pre-existing episode of AHF, and to describe subpopulations hospitalized in intensive care unit (ICU) versus cardiac care unit (CCU) versus ward. Methods and results: Data from 4,953 patients with AHF were collected via questionnaire from 666 hospitals. Clinical presentation included decompensated congestive HF (38.6%), pulmonary oedema (36.7%) and cardiogenic shock (11.7%). Patients with de novo episode of AHF (36.2%) were younger, had less comorbidities and lower blood pressure despite greater left ventricular ejection fraction (LVEF) and were more often admitted to ICU. Overall, intravenous (IV) diuretics were given in 89.7%, vasodilators in 41.1%, and inotropic agents (dobutamine, dopamine, adrenaline, noradrenaline and levosimendan) in 39% of cases. Overall hospital death rate was 12%, the majority due to cardiogenic shock (43%). More patients with de novo AHF (14.2%) than patients with a pre-existing episode of AHF (10.8%) (p=0.0007) died. There was graded mortality in ICU, CCU and ward patients with mortality in ICU patients being the highest (17.8%) (p<0.0001). Conclusions: Our data demonstrated the existence of different subgroups based on de novo or pre-existing episode(s) of AHF and the site of hospitalization. Recognition of these subgroups might improve management and outcome by defining specific therapeutic requirement
The Role of Regulated mRNA Stability in Establishing Bicoid Morphogen Gradient in Drosophila Embryonic Development
The Bicoid morphogen is amongst the earliest triggers of differential spatial pattern of gene expression and subsequent cell fate determination in the embryonic development of Drosophila. This maternally deposited morphogen is thought to diffuse in the embryo, establishing a concentration gradient which is sensed by downstream genes. In most model based analyses of this process, the translation of the bicoid mRNA is thought to take place at a fixed rate from the anterior pole of the embryo and a supply of the resulting protein at a constant rate is assumed. Is this process of morphogen generation a passive one as assumed in the modelling literature so far, or would available data support an alternate hypothesis that the stability of the mRNA is regulated by active processes? We introduce a model in which the stability of the maternal mRNA is regulated by being held constant for a length of time, followed by rapid degradation. With this more realistic model of the source, we have analysed three computational models of spatial morphogen propagation along the anterior-posterior axis: (a) passive diffusion modelled as a deterministic differential equation, (b) diffusion enhanced by a cytoplasmic flow term; and (c) diffusion modelled by stochastic simulation of the corresponding chemical reactions. Parameter estimation on these models by matching to publicly available data on spatio-temporal Bicoid profiles suggests strong support for regulated stability over either a constant supply rate or one where the maternal mRNA is permitted to degrade in a passive manner
Breakthrough invasive fungal disease in patients receiving posaconazole primary prophylaxis: a 4-year study
AbstractPosaconazole (PSC) is currently recommended as primary prophylaxis in neutropenic patients with acute myeloid leukaemia (AML) and in allogenic haematopoietic stem cell transplantation (AHSCT) recipients with graft-versus-host disease (GVHD). Studies focusing on breakthrough invasive fungal disease (IFD) upon PSC prophylaxis show disparate results. In order to evaluate the incidence of IFD in patients on PSC prophylaxis and identify IFD risk factors, we carried out a retrospective study of all consecutive patients on PP from January 2007 to December 2010 in our hospital. Breakthrough IFDs were identified from the database of the central pharmacy and the French administrative database (PMSI), registering final medical diagnoses of hospitalized patients. Medical data were reviewed to study proven or probable IFD, according to EORTC/MSG definition. PSC plasma concentrations (PPC) were also retrieved. Poisson models were used for statistical analysis. Two hundred and seventy-nine patients received PSC prophylaxis for a median duration of 1.4 months (range 0.2–17.9). Proven (n = 6) or probable (n = 3) IFDs were diagnosed in nine cases (3.2%). IFD incidence rate per 100 person-month was 1.65 (95% CI, 0.79–2.97). IFDs were candidaemia (Candida glabrata, n = 2), pulmonary invasive aspergillosis (n = 3), disseminated fusariosis (n = 2) and pulmonary mucormycosis (n = 2). Seven deaths were reported, directly related to IFD in three patients (33.3%). First dosage of PPC under 0.3 mg/L was the single significant risk factor for IFD (RR, 7.77; 95% CI, 1.30–46.5; p 0.025). Breakthrough IFD in patients receiving PSC prophylaxis is rare but associated with a poor outcome. Low PSC plasma concentrations are associated with an increased risk of IFD
Robotic milking technologies and renegotiating situated ethical relationships on UK dairy farms
Robotic or automatic milking systems (AMS) are novel technologies that take over the labor of dairy farming and reduce the need for human-animal interactions. Because robotic milking involves the replacement of 'conventional' twice-a-day milking managed by people with a system that supposedly allows cows the freedom to be milked automatically whenever they choose, some claim robotic milking has health and welfare benefits for cows, increases productivity, and has lifestyle advantages for dairy farmers. This paper examines how established ethical relations on dairy farms are unsettled by the intervention of a radically different technology such as AMS. The renegotiation of ethical relationships is thus an important dimension of how the actors involved are re-assembled around a new technology. The paper draws on in-depth research on UK dairy farms comparing those using conventional milking technologies with those using AMS. We explore the situated ethical relations that are negotiated in practice, focusing on the contingent and complex nature of human-animal-technology interactions. We show that ethical relations are situated and emergent, and that as the identities, roles, and subjectivities of humans and animals are unsettled through the intervention of a new technology, the ethical relations also shift. © 2013 Springer Science+Business Media Dordrecht
High resolution infrared absorption spectra, crystal field, and relaxation processes in CsCdBr_3:Pr^3+
High resolution low-temperature absorption spectra of 0.2% Pr^3+ doped
CsCdBr_3 were measured in the spectral region 2000--7000 cm-1. Positions and
widths of the crystal field levels within the 3H5, 3H4, 3F2, and 3F3 multiplets
of the Pr^3+ main center have been determined. Hyperfine structure of several
spectral lines has been found. Crystal field calculations were carried out in
the framework of the semiphenomenological exchange charge model (ECM).
Parameters of the ECM were determined by fitting to the measured total
splittings of the 3H4 and 3H6 multiplets and to the observed in this work
hyperfine splittings of the crystal field levels. One- and two-phonon
relaxation rates were calculated using the phonon Green's functions of the
perfect (CsCdBr_3) and locally perturbed (impurity dimer centers in
CsCdBr_3:Pr^3+) crystal lattice. Comparison with the measured linewidths
confirmed an essential redistribution of the phonon density of states in
CsCdBr_3 crystals doped with rare-earth ions.Comment: 16 pages, 5 tables, 3 figure
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