The role of cyclic nucleotide on fetal and neonantal erythropoiesis

For the purpose to reveal the changes in stimulatory effect of dibutyryl-cyclic- AMP on erythropoiesis during ontogenetic development, the author studied syntheses of DNA, RNA and protein of erythroid cells in fetal liver, neonatal and adult bone marrows of rats. In the bone marrow of neonatal animals erythropoiesis was stimulated by the intraperitoneal injection of cyclic nucleotide with enhanced DNA, RNA and protein syntheses of erythroid cells. Enhancing effect of dibutyryl-c-AMP on the erythropoiesis decreased gradually with advance of neonatal days. Autoradiographic observations revealed that in erythoid cells isolated from fetal liver and neonatal bone marrows, DNA-, RNA- and protein-snythesis was markedly stimulated by incubating with cyclic nucleotide, but not in those from adult bone marrow. Discussion was made on the changes in the regulatory mechanism of erythropoiesis according to the transition of hematopoietic organs during development.</p

Idiopathic Epicardial Ventricular Arrhythmias: Diagnosis and Ablation Technique from the Aortic Sinus of Valsalva

Idiopathic outflow tract arrhythmias (ventricular tachycardias or symptomatic premature ventricular contractions; OT-VT/PVCs) can originate from the left ventricular (LV) epicardium (Epi-VT/PVCs), and radiofrequency (RF) energy applications from the aortic sinus of Valsalva can eliminate Epi-VT/PVCs in selected patients. Among the various ECG findings, the R-wave duration index and R/S amplitude index in leads V1 or V2 are useful for identifying Epi-VT/PVCs, and the Q-wave ratio of leads aVL to aVR and S-wave amplitude in lead V1 are useful for differentiating between an Epi-VT/PVC originating from the LV epicardium remote from the left sinus of Valsalva (LSV) and that from the LSV. Tissue tracking imaging is a promising modality for identifying the origin of OT-VT/PVCs and for differentiating between an Epi-VT/PVC originating from the LV epicardium remote from the LSV and that from the LSV. If the origin of the Epi-VT/PVC is identified within the LSV, coronary and aortic angiography should be performed to assess the anatomic relationships between the Epi-VT/PVC origin and coronary arteries and aortic valve before the RF energy delivery. To avoid potential complications, RF ablation should be performed at the LSV using a maximum power of 35 watts and maximum temperature of 55°C. Epicardial mapping through the coronary venous system and the presence of potentials recorded from the ablation site within the LSV and their changes before and after the RF energy applications may be useful for diagnosing Epi-VT/PVCs or predicting a successful catheter ablation from the LSV

Matrix model criticality and resonant tunneling

We suggest that the Hermitian matrix models with resonant tunneling may exhibit novel criticality. Some features of the proposed criticality are explored. In particular, we argue that the new critical point is connected with the first-order transition.Comment: 11 pages, 6 figures. v2: References adde

Non-thermodynamic nature of the orbital angular momentum in neutral fermionic superfluids

We discuss the orbital angular momentum (OAM) and the edge mass current in neutral fermionic superfluids with broken time reversal symmetry. Recent mean field studies imply that total OAM of a uniform superfluid depends on boundary conditions and is not a thermodynamic quantity. We point out that this does not conflict with thermodynamics, because there is no intensive external field conjugate to OAM with which a uniform superfluid is stable in the thermodynamic limit, in sharp contrast to the orbital magnetization in a non-superfluid system. We establish a simple physical picture for the sensitivity of OAM to boundaries by introducing the notion of "unpaired fermions" and "fermionic Landau criterion" within a mean field description. In order to go beyond the mean field approximation, we perform a density matrix renormalization group calculation and conclude that the mean field understanding is essentially correct.Comment: 15 pages, 8 figures, to be published in Phys. Rev.