4,809 research outputs found
Anisotropic Dirac electronic structures of AMnBi2 (A = Sr, Ca)
Low-energy electronic structures in AMnBi(2) (A=alkaline earths) are investigated using a first-principles calculation and a tight binding method. An anisotropic Dirac dispersion is induced by the checkerboard arrangement of A atoms above and below the Bi square net in AMnBi(2 center dot) SrMnBi2 and CaMnBi2 have a different kind of Dirac dispersion due to the different stacking of nearby A layers, where each Sr (Ca) of one side appears at the coincident (staggered) xy position of the same element at the other side. Using the tight binding analysis, we reveal the chirality of the anisotropic Dirac electrons as well as the sizable spin-orbit coupling effect in the Bi square net. We suggest that the Bi square net provides a platform for the interplay between anisotropic Dirac electrons and the neighboring environment such as magnetism and structural changes.open6
Effect of Cultivar on Yield, Chemical Composition and British Thermal Unit Content of Three Switchgrass (\u3cem\u3ePanicum Virgatum L.\u3c/em\u3e) Cultivars
Switchgrass varieties with different sowing times and years of cultivation may change nutrient parameters, dry matter production and bio-fuel characteristics expressed as British Thermal Unit (BTU). The objective of this study was to report the effect of cultivar on dry matter yield, chemical composition and bio-fuel value of three Switchgrass (Panicum Virgatum L.) cultivars. Fossil fuel usage is a key human-related factor contributing to the production of green house gases. Biomass conversion into forms of energy is an old idea but one that is receiving increasing attention largely because of environmental, energy supply and agricultural market condition concerns (McCarl and Schneider 2001)
Recommended from our members
Rapid Intramitochondrial Zn2+ Accumulation in CA1 Hippocampal Pyramidal Neurons After Transient Global Ischemia: A Possible Contributor to Mitochondrial Disruption and Cell Death.
Mitochondrial Zn2+ accumulation, particularly in CA1 neurons, occurs after ischemia and likely contributes to mitochondrial dysfunction and subsequent neurodegeneration. However, the relationship between mitochondrial Zn2+ accumulation and their disruption has not been examined at the ultrastructural level in vivo. We employed a cardiac arrest model of transient global ischemia (TGI), combined with Timm's sulfide silver labeling, which inserts electron dense metallic silver granules at sites of labile Zn2+ accumulation, and used transmission electron microscopy (TEM) to examine subcellular loci of the Zn2+ accumulation. In line with prior studies, TGI-induced damage to CA1 was far greater than to CA3 pyramidal neurons, and was substantially progressive in the hours after reperfusion (being significantly greater after 4- than 1-hour recovery). Intriguingly, TEM examination of Timm's-stained sections revealed substantial Zn2+ accumulation in many postischemic CA1 mitochondria, which was strongly correlated with their swelling and disruption. Furthermore, paralleling the evolution of neuronal injury, both the number of mitochondria containing Zn2+ and the degree of their disruption were far greater at 4- than 1-hour recovery. These data provide the first direct characterization of Zn2+ accumulation in CA1 mitochondria after in vivo TGI, and support the idea that targeting these events could yield therapeutic benefits
The highly rearranged mitochondrial genomes of the crabs Maja crispata and Maja squinado (Majidae) and gene order evolution in Brachyura
Abstract
We sequenced the mitochondrial genomes of the spider crabs Maja crispata and Maja squinado (Majidae, Brachyura). Both genomes contain the whole set of 37 genes characteristic of Bilaterian genomes, encoded on both \u3b1- and \u3b2-strands. Both species exhibit the same gene order, which is unique among known animal genomes. In particular, all the genes located on the \u3b2-strand form a single block. This gene order was analysed together with the other nine gene orders known for the Brachyura. Our study confirms that the most widespread gene order (BraGO) represents the plesiomorphic condition for Brachyura and was established at the onset of this clade. All other gene orders are the result of transformational pathways originating from BraGO. The different gene orders exhibit variable levels of genes rearrangements, which involve only tRNAs or all types of genes. Local homoplastic arrangements were identified, while complete gene orders remain unique and represent signatures that can have a diagnostic value. Brachyura appear to be a hot-spot of gene order diversity within the phylum Arthropoda. Our analysis, allowed to track, for the first time, the fully evolutionary pathways producing the Brachyuran gene orders. This goal was achieved by coupling sophisticated bioinformatic tools with phylogenetic analysis
How much do you know about benign, preneoplastic, non-invasive and invasive neoplastic lesions of the urinary bladder classified according to the 2004 WHO scheme?
The aim of this essay is the self assessment of the level of knowledge of the 2004 WHO classification of bladder neoplasms through a series of MCQs, each associated a short commentary. This paper is directed to all who are involved with the application of this classification at the anticancer research, diagnostic, prognostic and therapeutic levels, in particular to uropathologists, urologists and oncologists
Observation of In-Plane Magnetic Field Induced Phase Transitions in FeSe
We investigate thermodynamic properties of FeSe under in-plane magnetic fields using torque magnetometry, specific heat, and magnetocaloric measurements. Below the upper critical field Hc2, we observed the field induced anomalies at H1 ∼ 15 T and H2 ∼ 22 T near H ∥ ab and below a characteristic temperature T* ∼ 2 K. The transition magnetic fields H1 and H2 exhibit negligible dependence on both temperature and field orientation. This contrasts to the strong temperature and angle dependence of Hc2, suggesting that these anomalies are attributed to the field induced phase transitions, originating from the inherent spin-density-wave instability of quasipaticles near the superconducting gap minima or possible Flude-Ferrell-Larkin-Ovchinnikov state in the highly spin-polarized Fermi surfaces. Our observations imply that FeSe, an atypical multiband superconductor with extremely small Fermi energies, represents a unique model system for stabilizing unusual superconducting orders beyond the Pauli limit
Observation of the in-plane magnetic field-induced phase transitions in FeSe
We investigate the thermodynamic properties of FeSe under the in-plane
magnetic fields using torque magnetometry, specific heat, magnetocaloric
measurements. Below the upper critical field Hc2, we observed the field-induced
anomalies at H1 ~ 15 T and H2 ~ 22 T near H//ab and below a characteristic
temperature T* ~ 2 K. The transition magnetic fields H1 and H2 exhibit
negligible dependence on both temperature and field orientation. This contrasts
with the strong temperature and angle dependence of Hc2, suggesting that these
anomalies are attributed to the field-induced phase transitions, originating
from the inherent spin-density-wave instability of quasiparticles near the
superconducting gap minima or possible Flude-Ferrell-Larkin-Ovchinnikov state
in the highly spin-polarized Fermi surfaces. Our observations imply that FeSe,
an atypical multiband superconductor with extremely small Fermi energies,
represents a unique model system for stabilizing unusual superconducting orders
beyond the Pauli limit.Comment: 8 pages, 4 figures, submitte
- …