1,609 research outputs found
Small-polaron hopping conductivity in bilayer manganite LaSrMnO
We report anisotropic resistivity measurements on a
LaSrMnO single crystal over a temperature range
from 2 to 400 K and in magnetic fields up to 14 T. For K, the
temperature dependence of the zero-field in-plane resistivity
obeys the adiabatic small polaron hopping mechanism, while the out-of-plane
resistivity can be ascribed by an Arrhenius law with the same
activation energy. Considering the magnetic character of the polarons and the
close correlation between the resistivity and magnetization, we developed a
model which allows the determination of . The excellent
agreement of the calculations with the measurements indicates that small
polarons play an essential role in the electrical transport properties in the
paramagnetic phase of bilayer manganites.Comment: 4 pages, 3 figures, to appear in Physical Review
Synthesis and Biological Evaluation of Modified 2-Deoxystreptamine Dimers
Aminoglycosides are powerful antibiotics, but the emergence of resistant bacterial strains has prompted the search for analogues with better pharmacological profiles. The synthesis of 2-deoxystreptamine (2-DOS) dimers linked by polyamines and analogues based on furylcarbopeptoid skeletons is described. Potent and selective ligands for bacterial 16S rRNA were identified using microarray techniques by determining the affinity of these derivatives toward bacterial and human ribosomal RNA
Ultrasonic evidence of an uncorrelated cluster formation temperature in manganites with first-order magnetic transition at T_C
Ultrasonic attenuation and phase velocity measurements have been carried out
in the ferromagnetic perovskites La_{2/3}Ca_{1/3}MnO_3 and
La_{2/3}Sr_{1/3}MnO_3. Data show that the transition at the Curie temperature,
T_C, changes from first- to second-order as Sr replaces Ca in the perovskite.
The compound with first-order transition shows also another transition at a
temperature T* > T_C. We interpret the temperature window T_C < T < T* as a
region of coexistence of a phase separated regime of metallic and insulating
regions, in the line of recent theoretical proposals.Comment: 4 pages, 2 figure
Extracorporeal immune therapy with immobilized agonistic anti-Fas antibodies leads to transient reduction of circulating neutrophil numbers and limits tissue damage after hemorrhagic shock/resuscitation in a porcine model
Background: Hemorrhagic shock/resuscitation is associated with aberrant neutrophil activation and organ failure. This experimental porcine study was done to evaluate the effects of Fas-directed extracorporeal immune therapy with a leukocyte inhibition module (LIM) on hemodynamics, neutrophil tissue infiltration, and tissue damage after hemorrhagic shock/resuscitation. Methods: In a prospective controlled double-armed animal trial 24 Munich Mini Pigs (30.3 +/- 3.3 kg) were rapidly haemorrhaged to reach a mean arterial pressure (MAP) of 35 +/- 5 mmHg, maintained hypotensive for 45 minutes, and then were resuscitated with Ringer's solution to baseline MAP. With beginning of resuscitation 12 pigs underwent extracorporeal immune therapy for 3 hours (LIM group) and 12 pigs were resuscitated according to standard medical care (SMC). Haemodynamics, haematologic, metabolic, and organ specific damage parameters were monitored. Neutrophil infiltration was analyzed histologically after 48 and 72 hours. Lipid peroxidation, and apoptosis were specifically determined in lung, bowel, and liver. Results: In the LIM group, neutrophil counts were reduced versus SMC during extracorporeal immune therapy. After 72 hours, the haemodynamic parameters MAP and cardiac output (CO) were significantly better in the LIM group. Histological analyses showed reduction of shock-related neutrophil tissue infiltration in the LIM group, especially in the lungs. Lower amounts of apoptotic cells and lipid peroxidation were found in organs after LIM treatment. Conclusions: Transient Fas-directed extracorporeal immune therapy may protect from posthemorrhagic neutrophil tissue infiltration and tissue damage
ICOS costimulation at the tumor site in combination with CTLA-4 blockade therapy elicits strong tumor immunity
Cytotoxic T lymphocyte-associated protein 4 (CTLA-4) blockade therapy is able to induce long-lasting antitumor responses in a fraction of cancer patients. Nonetheless, there is still room for improvement in the quest for new therapeutic combinations. ICOS costimulation has been underscored as a possible target to include with CTLA-4 blocking treatment. Herein, we describe an ICOS agonistic aptamer that potentiates T cell activation and induces stronger antitumor responses when locally injected at the tumor site in combination with anti-CTLA-4 antibody in different tumor models. Furthermore, ICOS agonistic aptamer was engineered as a bi-specific tumor-targeting aptamer to reach any disseminated tumor lesions after systemic injection. Treatment with the bi-specific aptamer in combination with CTLA-4 blockade showed strong antitumor immunity, even in a melanoma tumor model where CTLA-4 treatment alone did not display any significant therapeutic benefit. Thus, this work provides strong support for the development of combinatorial therapies involving anti-CTLA-4 blockade and ICOS agonist tumor-targeting agents
Dietary Intake, Nutritional Adequacy and Food Sources of Total Fat and Fatty Acids, and Relationships with Personal and Family Factors in Spanish Children Aged One to <10 Years: Results of the EsNuPI Study
We aimed to determine the usual intake of total fat, fatty acids (FAs), and their main food
sources in a representative cohort of the Spanish pediatric population aged 1 to <10 years (n = 707)
who consumed all types of milk and an age-matched cohort who consumed adapted milk over the last
year (including follow-on formula, toddlerâs milk, growing-up milk, and fortified and enriched milks)
(n = 741) who were participants in the EsNuPI study (in English, Nutritional Study in the Spanish
Pediatric Population). Dietary intake, measured through two 24 h dietary recalls, was compared to
the European Food Safety Authority (EFSA) and the Food and Agriculture Organization of the United Nations (UN-FAO) recommendations. Both cohorts showed a high intake of saturated fatty acids
(SFAs), according to FAO recommendations, as there are no numerical recommendations for SFAs at
EFSA. Also, low intake of essential fatty acids (EFAs; linoleic acid (LA) and α-linolenic acid (ALA))
and long-chain polyunsaturated fatty acids (LC-PUFA) of the n-3 series, mainly docosahexaenoic
acid (DHA) were observed according to EFSA and FAO recommendations. The three main sources of
total fat and different FAs were milk and dairy products, oils and fats, and meat and meat products.
The consumption of adapted milk was one of the main factors associated with better adherence to
the nutritional recommendations of total fat, SFAs, EFAs, PUFAs; and resulted as the main factor
associated with better adherence to n-3 fatty acids intake recommendations. Knowledge of the dietary
intake and food sources of total fat and FAs in children could help in designing and promoting
effective and practical age-targeted guidelines to promote the consumption of EFA- and n-3 PUFA-rich
foods in this stage of life
- âŠ