275 research outputs found
Signatures of topology in ballistic bulk transport of HgTe quantum wells
We calculate bulk transport properties of two-dimensional topological
insulators based on HgTe quantum wells in the ballistic regime. Interestingly,
we find that the conductance and the shot noise are distinctively different for
the so-called normal regime (the topologically trivial case) and the so-called
inverted regime (the topologically non-trivial case). Thus, it is possible to
verify the topological order of a two-dimensional topological insulator not
only via observable edge properties but also via observable bulk properties.
This is important because we show that under certain conditions the bulk
contribution can dominate the edge contribution which makes it essential to
fully understand the former for the interpretation of future experiments in
clean samples.Comment: 5 pages, 4 figure
Diabetic ketoacidosis with mild hyperglycemia associated with the use of canagliflozin. Report of one case with type 1 diabetes
Indexación: Web of Science; Scopus; Scielo.Diabetic ketoacidosis with mild hyperglycemia is a major complication of sodium-glucose cotransporter 2 inhibitors. Although its use is not approved for patients with type 1 diabetes mellitus, the drug is often prescribed with the hope of optimizing metabolic control. We report a 20 years old female with hypo-thyroidism and type 1 diabetes consulting for vomiting and abdominal pain. The patient had used canagliflozin during the two previous months. Laboratory showed a blood glucose of 200 mg/dl, a severe metabolic acidosis (pH 7.1) and ketonemia. The patient was successfully treated in the intensive care unit.http://ref.scielo.org/65brd
Use of statins and the risk of new onset Diabetes Mellitus
Indexación: Web of Science; ScieloSe ha descrito relación entre el uso de estatinas y aparición de nueva diabetes. Se revisa advertencia de la FDA, asà como análisis de estudios y meta análisis, que permiten deducir una acción de las estatinas que favorece el desarrollo de nueva diabetes. Las precauciones del uso de estatinas se deben orientar a pacientes con factores de riesgo de diabetes en prevención primaria cardiovascular. Se expresa la necesidad de estudios prospectivos con objetivos primarios especÃficos, para mayor precisión de información y adopción de recomendaciones basadas en alto nivel de evidencias.Relationship between statin use and appearance of new diabetes has been described. We review the FDA warning and analysis of studies and meta-analysis, which point to an action of statins which favors the development of new diabetes. Precautions of statin use should guide patients with risk factors for diabetes in primary cardiovascular prevention. It expresses the need for prospective studies with specific primary objectives, for accuracy of information and making recommendations based on high-level evidence.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-85602012000300007&nrm=is
PENINGKATAN KADAR LOVASTATIN ANGKAK OLEH Monascuspurpureus KO-KULTUR DENGAN Endomycopsis Burtontt [Improvement of Lovastatin Angkak Production by Monascus Purpureus Strains Co-Cultured with Endomycopsis Burtonii]
Lovastatin is a bioactive material of statin groups and has been used to reduce cholesterol through inhibiting HMG Co-A reductase enzyme activities. Three indigenous strains of Monascus purpureus and three mutans were used in this study produced lovastatin at the range of 0,1 - 1,42%. The objectives of this study were to increase lovastatin productions by co-cultured with several concentrations of Endomycopsis burtonii. M. purpureus (10 cfu/ml) was co-cultured with various concentrations of E. burtonii (10M0 ) cfu/ral at three different feeding times (day 2, 4, and 6). Feeding times and concentrations of E. burtonii significantly increased production of lovastatin by four strains of M. purpureus (JMBA5K, AID, JMBA and TOS). The highest production of lovastatin was achieved by M. purpureus TOS co-cultured by E. burtonii at 10 cfu/ml added at day 6. Expression of the genes that responsible for lovastatin production were analyzed by PCR and RT-PCR method. The phenotypic character of M. purpureus TOS with high lovastatin production was conformed by the high intensity of its gene expression
Single valley Dirac fermions in zero-gap HgTe quantum wells
Dirac fermions have been studied intensively in condensed matter physics in
recent years. Many theoretical predictions critically depend on the number of
valleys where the Dirac fermions are realized. In this work, we report the
discovery of a two dimensional system with a single valley Dirac cone. We study
the transport properties of HgTe quantum wells grown at the critical thickness
separating between the topologically trivial and the quantum spin Hall phases.
At high magnetic fields, the quantized Hall plateaus demonstrate the presence
of a single valley Dirac point in this system. In addition, we clearly observe
the linear dispersion of the zero mode spin levels. Also the conductivity at
the Dirac point and its temperature dependence can be understood from single
valley Dirac fermion physics.Comment: version 2: supplementary material adde
Surface state charge dynamics of a high-mobility three dimensional topological insulator
We present a magneto-optical study of the three-dimensional topological
insulator, strained HgTe using a technique which capitalizes on advantages of
time-domain spectroscopy to amplify the signal from the surface states. This
measurement delivers valuable and precise information regarding the surface
state dispersion within <1 meV of the Fermi level. The technique is highly
suitable for the pursuit of the topological magnetoelectric effect and axion
electrodynamics.Comment: Published version, online Sept 23, 201
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