1,496 research outputs found
Treatment of epidermoid tumors with gamma knife radiosurgery: case series
Epidermoid tumors (ETs) are benign lesions that are treated
mainly by means of surgical resection, with overall good results. External beam
radiotherapy is an alternative treatment for those recurrent tumors, in which a
second surgery might not be the best choice for the patient. A little information
exists about the effectiveness of gamma knife radiosurgery for the treatment of
newly diagnosed and recurrent ETs. We present three cases of ETs treated with
gamma knife radiosurger
Fatigue Study of the Pre-Corroded 6082-T6 Aluminum Alloy in Saline Atmosphere
[Abstract] This work studies the influence of the saline atmospheric corrosion on the fatigue strength of 6061-T6 aluminum alloy. For this purpose, this alloy was subjected to tests in a salt spray corrosion chamber at different exposure times (1, 2, and 3 months) according to ASTM B117 standard. The morphological study of the pits was carried out by confocal microscopy. Subsequently, fatigue tests were performed at variable stresses whose maximum stress (Smax) was between 30% and 95% of the yield strength (S0) in order to keep them within the zone of elastic behavior of the material. Data were analyzed using the Basquin equation and the maximum likelihood function method. The results show a similar decrease in the conventional fatigue limit (2 × 106 cycles) after one month (98 MPa) and two months (91 MPa) of corrosion. After three months of corrosion, the material showed a very important reduction in the fatigue limit (68 MPa) with respect to the uncorroded material (131 MPa). The data of Se/S0 (fatigue limit/yield strength) versus the ratio Pm/Dm (pit average depth/pit diameter at zero depth) can be fitted to a logarithmic curve
TRPC6 channels are required for proliferation, migration and invasion of breast cancer cell lines by modulation of Orai1 and Orai3 surface exposure
Transient receptor potential channels convey signaling information from a number of stimuli to a wide variety of cellular functions, mainly by inducing changes in cytosolic Ca2+ concentration. Different members of the TRPC, TRPM and TRPV subfamilies have been reported to play a role in tumorigenesis. Here we show that the estrogen receptor positive and triple negative breast cancer cell lines, MCF7 and MDA-MB-231, respectively, exhibit enhanced expression of the TRPC6 channel as compared to the non-tumoral MCF10A cell line. In vitro TRPC6 knockdown using shRNA impaired MCF7 and MDA-MB-231 cell proliferation, migration and invasion detected by BrdU incorporation, wound healing and Boyden chamber assays, respectively. Using RNAi-mediated TRPC6 silencing as well as overexpression of the pore-dead dominant-negative TRPC6 mutant we have found that TRPC6 plays a relevant role in the activation of store-operated Ca2+ entry in the breast cancer cell lines but not in non-tumoral breast cells. Finally, we have found that TRPC6 interacts with Orai1 and Orai3 in MCF7 and MDA-MB-231 cells and is required for the translocation of Orai1 and Orai3 to the plasma membrane in MDA-MB-231 and MCF7 cells, respectively, upon Ca2+ store depletion. These findings introduce a novel mechanism for the modulation of Ca2+ influx and the development of different cancer hallmarks in breast cancer cells
Are black holes a serious threat to scalar field dark matter models?
Classical scalar fields have been proposed as possible candidates for the
dark matter component of the universe. Given the fact that super-massive black
holes seem to exist at the center of most galaxies, in order to be a viable
candidate for the dark matter halo a scalar field configuration should be
stable in the presence of a central black hole, or at least be able to survive
for cosmological time-scales. In the present work we consider a scalar field as
a test field on a Schwarzschild background, and study under which conditions
one can obtain long-lived configurations. We present a detailed study of the
Klein-Gordon equation in the Schwarzschild spacetime, both from an analytical
and numerical point of view, and show that indeed there exist quasi-stationary
solutions that can remain surrounding a black hole for large time-scales.Comment: 34 pages, 13 figure
Exploring the high-temperature electrical performance of Ca3-xLaxCo4O9 thermoelectric ceramics for moderate and low substitution levels
Aliovalent substitutions in Ca3Co4O9 often result in complex effects on the electrical prop-erties and the solubility, and impact of the substituting cation also depends largely on the prepara-tion and processing method. It is also well-known that the monoclinic symmetry of this material’s composite crystal structure allows for a significant hole transfer from the rock salt-type Ca2CoO3 buffer layers to the hexagonal CoO2 ones, increasing the concentration of holes and breaking the electron–hole symmetry from the latter layers. This work explored the relevant effects of relatively low La-for-Ca substitutions, for samples prepared and processed through a conventional ceramic route, chosen for its simplicity. The obtained results show that the actual substitution level does not exceed 0.03 (x < 0.03) in Ca3-xLaxCo4O9 samples with x = 0.01, 0.03, 0.05 and 0.07 and that further introduction of lanthanum results in simultaneous Ca3Co4O9 phase decomposition and secondary Ca3Co2O6 and (La,Ca)CoO3 phase formation. The microstructural effects promoted by this phase evolution have a moderate influence on the electronic transport. The electrical measurements and determined average oxidation state of cobalt at room temperature suggest that the present La sub-stitutions might only have a minor effect on the concentration of charge carriers and/or their mobil-ity. The electrical resistivity values of the Ca3-xLaxCo4O9 samples with x = 0.01, 0.03 and 0.05 were found to be ~1.3 times (or 24%) lower (considering mean values) than those measured for the pris-tine Ca3Co4O9 samples, while the changes in Seebeck coefficient values were only moderate. The highest power factor value calculated for Ca2.99La0.01Co4O9 (~0.28 mW/K2m at 800 °C) is among the best found in the literature for similar materials. The obtained results suggest that low rare-earth substitutions in the rock salt-type layers can be a promising pathway in designing and improving these p-type thermoelectric oxides, provided by the strong interplay between the mobility of charge carriers and their concentration, capable of breaking the electron–hole symmetry from the conduc-tive layers.publishe
Genetic heterogeneity in the toxicity to systemic adenoviral gene transfer of interleukin-12
Despite the efficacy of IL-12 in cancer experimental models, clinical trials with systemic recombinant IL-12 showed unacceptable toxicity related to endogenous IFNgamma production. We report that systemic administration of a recombinant adenovirus encoding IL-12 (AdCMVmIL-12) has a dramatically different survival outcome in a number of mouse pure strains over a wide range of doses. For instance at 2.5 x 10(9) p.f.u., systemic AdCMVmIL-12 killed all C57BL/6 mice but spared all BALB/c mice. Much higher IFNgamma concentrations in serum samples of C57BL/6 than in those from identically treated BALB/c were found. Causes for heterogeneous toxicity can be traced to differences among murine strains in the levels of gene transduction achieved in the liver, as assessed with adenovirus coding for reporter genes. In accordance, IL-12 serum concentrations are higher in susceptible mice. In addition, sera from C57BL/6 mice treated with AdCMVmIL-12 showed higher levels of IL-18, a well-known IFNgamma inducer. Interestingly, lethal toxicity in C57BL/6 mice was abolished by administration of blocking anti-IFNgamma mAbs and also by simultaneous depletion of T cells, NK cells, and macrophages. These observations together with the great dispersion of IFNgamma produced by human PBMCs upon in vitro stimulation with IL-12, or infection with recombinant adenovirus encoding IL-12, suggest that patients might also show heterogeneous degrees of toxicity in response to IL-12 gene transfer
Therapeutic effects of psyllium in type 2 diabetic patients
P. 830-842The study included three phases: phase 1 (1 week), phase 2 (treatment, 14 g fibre=day, 6 weeks) and phase 3 (4 weeks).
At the end of each phase a clinical evaluation was performed after the ingestion of a test breakfast of 1824.2 kJ (436 kcal).
Measurements included concentrations of blood glucose, insulin, fructosamine, GHbA1c, C-peptide and 24 h urinary glucose
excretion. In addition, uric acid, cholesterol and several mineral and vitamin concentrations were also evaluated.
Twenty type 2 diabetic patients (12 men and 8 women) participated in the study with a mean age of 67.4 y for men
and 66 y for women. The mean body mass index of men was 28.2 kg=m2 and that of women 25.9 kg=m2.
Glucose absorption decreased significantly in the presence of psyllium (12.2%); this reduction is not associated with an
important change in insulin levels (5%). GHbA1c, C-peptide and 24 h urinary glucose excretion decreased (3.8, 14.9 and 22.5%,
respectively) during the treatment with fibre (no significant differences) as well as fructosamine (10.9%, significant differences).
Psyllium also reduced total and LDL cholesterol (7.7 and 9.2%, respectively, significant differences), and uric acid (10%,
significant difference). Minerals and vitamins did not show important changes, except sodium that increased significantly after
psyllium administration.S
Mutation of vsx genes in zebrafish highlights the robustness of the retinal specification network
Genetic studies in human and mice have established a dual role for Vsx genes in retina development: an early function in progenitors' specification, and a later requirement for bipolar-cells fate determination. Despite their conserved expression patterns, it is currently unclear to which extent Vsx functions are also conserved across vertebrates, as mutant models are available only in mammals. To gain insight into vsx function in teleosts, we have generated vsx1 and vsx2 CRISPR/Cas9 double knockouts (vsxKO) in zebrafish. Our electrophysiological and histological analyses indicate severe visual impairment and bipolar cells depletion in vsxKO larvae, with retinal precursors being rerouted toward photoreceptor or Müller glia fates. Surprisingly, neural retina is properly specified and maintained in mutant embryos, which do not display microphthalmia. We show that although important cis-regulatory remodelling occurs in vsxKO retinas during early specification, this has little impact at a transcriptomic level. Our observations point to genetic redundancy as an important mechanism sustaining the integrity of the retinal specification network, and to Vsx genes regulatory weight varying substantially among vertebrate species
Abnormal sympathoadrenal development and systemic hypotension in PHD3<sup>–/–</sup> mice.
Modelling the predictable effects of dietary lipid sources on the fillet fatty acid composition of one-year-old gilthead sea bream (Sparus aurata L.)
The present study aimed to ascertain the different fatty acid (FA) descriptors linking dietary and muscle FA composition in one-year-old gilthead sea bream. For that purpose, our own published data along with additional data from the present study were compiled and analysed. High linear correlations (r2 = 0.90, P < 0.001) between dietary and muscle fatty acid composition were reported for monoenes, C18 polyunsaturated FA (PUFA) and long-chain PUFA. Prediction deviations due to changes in muscle fatness were analyzed in an independent trial with two different feeding levels (full ration size, 30% restriction ration). Regardless of feeding regimen, predicted values for muscle FA at low concentrations deviated (P < 0.001) from observed values, but good predictions with less than 6% deviations were found for abundant fatty acids (16:1n-7, 18:1n-9, 18:2n-6, 18:3n-3, 20:4n-6, 20:5n-3, 22:6n-3). All this highlights the predictable effects of dietary oils in the muscle FA composition of gilthead sea bream, although further research is needed to cover all the range of commercial fish size and for the up-scaling of laboratory results to different fish farming conditions
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