4,930 research outputs found
Interplay between antiferromagnetic order and spin polarization in ferromagnetic metal/electron-doped cuprate superconductor junctions
Recently we proposed a theory of point-contact spectroscopy and argued that
the splitting of zero-bias conductance peak (ZBCP) in electron-doped cuprate
superconductor point-contact spectroscopy is due to the coexistence of
antiferromagnetic (AF) and d-wave superconducting orders [Phys. Rev. B {\bf
76}, 220504(R) (2007)]. Here we extend the theory to study the tunneling in the
ferromagnetic metal/electron-doped cuprate superconductor (FM/EDSC) junctions.
In addition to the AF order, the effects of spin polarization, Fermi-wave
vector mismatch (FWM) between the FM and EDSC regions, and effective barrier
are investigated. It is shown that there exits midgap surface state (MSS)
contribution to the conductance to which Andreev reflections are largely
modified due to the interplay between the exchange field of ferromagnetic metal
and the AF order in EDSC. Low-energy anomalous conductance enhancement can
occur which could further test the existence of AF order in EDSC. Finally, we
propose a more accurate formula in determining the spin polarization value in
combination with the point-contact conductance data.Comment: 9 pages, 8 figure
Fiber-top atomic force microscope
We present the implementation of an atomic force microscope (AFM) based on fiber-top design. Our results demonstrate that the performances of fiber-top AFMs in contact mode are comparable to those of similar commercially available instruments. Our device thus represents an interesting\ud
alternative to existing AFMs, particularly for applications outside specialized research laboratories, where a compact, user-friendly, and versatile tool might often be preferred
Aging and hyponutrition; A challenge for the sustainability of the NHS: Conclusions of the 9th abbot-SENPE debate forum
La desnutrición es un problema común en todos los
niveles de atención sanitaria, desde atención primaria a
especializada y en centros de atención geriátrica. Su incidencia
en los hospitales es del 40% y en las residencias de
mayores supera el 60%. Esto último es de gran importancia,
tienen una alta relación con el progresivo envejecimiento
de la población europea, y es la mayor y más
frecuente causa de discapacidad en la población anciana
que vive en su domicilio o en instituciones.
Países como Holanda, Dinamarca o el Reino Unido han
desarrollado Planes Estratégicos Integrales para luchar
contra la desnutrición desarrollando e implantando guías,
estableciendo cribados obligatorios en los ingresos y altas
hospitalarias, en las residencias en ancianos, etc. En nuestro
país, en una acción conjunta de SENPE y la Fundación
Abbott, estamos desarrollando un Plan Estratégico Integral
(Proyecto + nutridos) en el que establecemos recomendaciones
claras, precisas y validadas para efectuar cribaje
nutricional tanto en pacientes hospitalizados, como en los
institucionalizados y en los mayores ambulatorios.
En este tema deben de ser tenidos en cuenta los
aspectos sociales y financieros. La desnutrición es con
mucha frecuencia deficientemente reconocida y tratada.
Ello tiene un impacto negativo sobre los pacientes individuales
en términos de morbilidad, mortalidad, independencia
y calidad de vida, y sobre los sistemas de cuidado
sanitario en términos de uso de recursos y costesHyponutrition is a common problem at all health care
levels, from primary to specialized care, as well as in geriatric
care. Its incidence in a hospital setting is 40% and 60%
in nursing homes. This is very important, it is highly related
with progressive aging of the European population, and is
the biggest and most frequent cause of disability among the
elderly population living at home or institutions.
Countries such as Holland, Denmark, or the United
Kingdom have developed Comprehensive Strategic Plans
to fight against hyponutrition by developing and implementing
guidelines, establishing mandatory screenings at the
moment of hospital admission and discharge, at nursing
homes, etc. In our country, a combined action of SENPE
and Abbott Foundation is developing a Comprehensive
Strategic Plan (+ nutridos Project) in which clear, precise,
and validated recommendations are established to perform
nutritional screening both in hospitalized patients and institutionalized
and ambulatory elderly people.
This issue has to take into account the social and financial
aspects. Hyponutrition is many times insufficiently
recognized and treated. This has a negative impact on the
individual patient in terms of morbidity, mortality, independence,
and quality of life, as well as on the health care
systems in terms of use of health care resources and cost
LIGHT AND ELECTRON MICROSCOPIC RADIOAUTOGRAPHY OF HEPATIC CELL NUCLEOLI IN MICE TREATED WITH ACTINOMYCIN D
Nucleolar partition induced by actinomycin D was used to demonstrate some aspects of nucleolar RNA synthesis and release in mouse hepatic cells, with light and electron microscopic radioautography. The effect of the drug on RNA synthesis and nucleolar morphology was studied when actinomycin D treatment preceded labeling with tritiated orotic acid. Nucleolar partition, consisting of a segegration into granular and fibrillar parts was visible if a dosage of 25 µg of actinomycin D was used, but nucleolar RNA was still synthesized. After a dosage of 400 µg of actinomycin D, nucleolar RNA synthesis was completely stopped If labeling with tritiated orotic acid preceded treatment with 400 µg of actinomycin D, labeled nucleolar RNA was present 15 min after actinomycin D treatment while high resolution radioautography showed an association of silver grains with the granular component. At 30 min after actinomicyn D treatment all labeling was lost. Since labeling was associated with the granular component the progressive loss of label as a result of actinomycin D treatment indicated a release of nucleolar granules. The correlation between this release and the loss of 28S RNA from actinomycin D treated nucleoli as described in the literature is discussed
The effects of 5-fluorouracil and interferon-alpha on early healing of experimental intestinal anastomoses.
The continuing search for effective adjuvant therapy after resection of intestinal malignancies has prompted a growing interest in both immediate post-operative regional chemotherapy and the combination of 5-fluorouracil (5-FU) and interferon-alpha as drugs of choice. We have compared the effects of both compounds, alone and together, on early healing of intestinal anastomoses. Four groups (n = 26 each) of rats underwent resection and anastomosis of both ileum and colon: a control group and three groups receiving intraperitoneal 5-FU, interferon-alpha or both on the day of surgery and the next 2 days. Animals were killed 3 or 7 days (n = 10 each) after operation in order to measure anastomotic strength and hydroxyproline content. The remaining six animals in each group were used to study anastomotic collagen synthetic capacity at day 3. Three days after operation, ileal anastomotic bursting pressure was lowered by 37% in the 5-FU/interferon-alpha group (P = 0.0104). At day 7, anastomotic breaking strength was reduced significantly in ileum (P = 0.0221) and colon (P = 0.0054) of the 5-FU/interferon-alpha group and in colon of the interferon-alpha group (P = 0.0221). Collagen synthetic capacity was strongly suppressed by 5-FU but not by interferon-alpha. However, no differences in anastomotic hydroxyproline content were observed between groups at both days 3 and 7. Thus, post-operative use of interferon-alpha, in particular in combination with 5-FU, may be detrimental to anastomotic repair in the intestine
- …