Systematic study of Ga1−x_{1-x}Inx_xAs self-assembled quantum wires with different interfacial strain relaxation

A systematic theoretical study of the electronic and optical properties of Ga$_{1-x}$In$_x$As self-assembled quantum-wires (QWR's) made of short-period superlattices (SPS) with strain-induced lateral ordering is presented. The theory is based on the effective bond-orbital model (EBOM) combined with a valence-force field (VFF) model. Valence-band anisotropy, band mixing, and effects due to local strain distribution at the atomistic level are all taken into account. Several structure models with varying degrees of alloy mixing for lateral modulation are considered. A valence force field model is used to find the equilibrium atomic positions in the QWR structure by minimizing the lattice energy. The strain tensor at each atomic (In or Ga) site is then obtained and included in the calculation of electronic states and optical properties. It is found that different local arrangement of atoms leads to very different strain distribution, which in turn alters the optical properties. In particular, we found that in model structures with thick capping layer the electron and hole are confined in the Ga-rich region and the optical anisotropy can be reversed due to the variation of lateral alloying mixing, while for model structures with thin capping layer the electron and hole are confined in the In-rich region, and the optical anisotropy is much less sensitive to the lateral alloy mixing.Comment: 23 pages, and 8 figure

Multi-Stability of Electromagnetically Induced Transparency in Atom-Assisted Optomechanical Cavities

We study how an oscillating mirror affects the electromagnetically induced transparency (EIT) of an atomic ensemble, which is confined in a gas cell placed inside a micro-cavity with an oscillating mirror in one end. The oscillating mirror is modeled as a quantum mechanical harmonic oscillator. The cavity field acts as a probe light of the EIT system and also produces a light pressure on the oscillating mirror. The back-action from the mirror to the cavity field results in several (from one to five) steady-states for this atom-assisted optomechanical cavity, producing a complex structure in its EIT. We calculate the susceptibility with respect to the few (from one to three) stable solutions found here for the equilibrium positions of the oscillating mirror. We find that the EIT of the atomic ensemble can be significantly changed by the oscillating mirror, and also that the various steady states of the mirror have different effects on the EIT.Comment: 10 pages, 9 figure

The Effects of Furosemide and Hypoxia on CIick-Evoked Otoacoustic Emissions in Anesthetized Guinea Pigs

From the concepts of well known ototoxic effects of loop diuretics and hypoxic state, twenty anesthetized guinea pigs with diuretics and/or hypoxia were evaluated with click-evoked otoacoustic emissions (CEOAEs) by timesequential monitoring. Furosemide 25 mg/kg was infused intravenously and CEOAEs were measured before and 5, 10, 20, 30, 45 and 60 minutes after injection in 8 guinea pigs. Both echo responses and reproducibilities were decreased significantly at 10 minutes after injection and showed minimal level at 20 minutes. Recovery of CEOAEs was noted by spectral analysis at 30 minutes after injection, and full recovery of CEOAEs was evident after then. At 60 minutes after injection, hypoxia of 20 seconds by turning off the artificial respirator was added. The CEOAEs showed statistically significant decreases compared with those of prehypoxic state (p<O.OI). The CEOAEs of 8 guinea pigs with injection of furosemide. 50 mg/kg showed decreased responses and no fr recoveries for the 60 minutes observation periods. Findings from this study support the clinical utility of CEOAEs as a screening test for early detection of various ototoxicities

Pseudocyst of Temporal Bone and Posterior Cranial Fossa Caused by Cholesterol Granuloma

Accurate preoperative diagnosis of temporal bone lesion is critical because the surgical approaches used for this region are different depending upon the specific disease process involved. While CT and MID have improved the accuracy of preoperative diagnosis of temporal bone pathology, these imaging studies are most helpful when used in conjuction with one another. This case showed a pseudocyst of lhe temporal bone and posterior cranial fossa caused by a blockage of aditus ad antrum due to cholesterol granuloma. The patient was a 33-year-old man with a right-sided temporo-occipital headache. Computed tomography revealed a mass involving the temporal bone and posterior cranial fossa with central bony density. On MRI, the mass showed isosignal intensity with respect to the brain on Tl-weighted image, hyperintense signal to the brain on T2-weighted image, peripheral enhancement on gadolinum enhanced image. Histologically, the mass showed a cholesterol cleft, multinucleated giant cells and a fibrotic capsule without endothelial lining. The patient had no postoperative difficulty and was discharged without problems

Diversity and distribution of the genus Scrophularia L. (Scrophulariaceae) in Uzbekistan

This article presents a new checklist of Scrophularia in Uzbekistan. The synopsis includes 21 species; one of them is national endemic, and seven species were newly recorded for Uzbekistan as a result of field collecting missions, studies, and examination of Tashkent (TASH), St.-Petersburg (LE), Almaty (AA), and Moscow (MW) herbarium collections. The geographical distribution of Scrophularia in Uzbekistan was mapped and analyzed. The identification key, a table of comparative diagnostic characters, nomenclatural types, and ecological data are provided. (C) 2019 National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA), Publishing Services by Elsevier.Peer reviewe

Properties of Central Caustics in Planetary Microlensing

To maximize the number of planet detections, current microlensing follow-up observations are focusing on high-magnification events which have a higher chance of being perturbed by central caustics. In this paper, we investigate the properties of central caustics and the perturbations induced by them. We derive analytic expressions of the location, size, and shape of the central caustic as a function of the star-planet separation, $s$, and the planet/star mass ratio, $q$, under the planetary perturbative approximation and compare the results with those based on numerical computations. While it has been known that the size of the planetary caustic is \propto \sqrt{q}, we find from this work that the dependence of the size of the central caustic on $q$ is linear, i.e., \propto q, implying that the central caustic shrinks much more rapidly with the decrease of $q$ compared to the planetary caustic. The central-caustic size depends also on the star-planet separation. If the size of the caustic is defined as the separation between the two cusps on the star-planet axis (horizontal width), we find that the dependence of the central-caustic size on the separation is \propto (s+1/s). While the size of the central caustic depends both on $s$ and q, its shape defined as the vertical/horizontal width ratio, R_c, is solely dependent on the planetary separation and we derive an analytic relation between R_c and s. Due to the smaller size of the central caustic combined with much more rapid decrease of its size with the decrease of q, the effect of finite source size on the perturbation induced by the central caustic is much more severe than the effect on the perturbation induced by the planetary caustic. Abridged.Comment: 5 pages, 4 figures, ApJ accepte

A Novel Meatoplasty Method in Canal Wall Down Tympanomastoidectomy: A Perichondrial Posterior Fixation Technique

ObjectivesAlthough it is well recognized that a small meatus after canal wall down (CWD) tympanomastoidectomy can cause a lifetime problem, unsatisfactory results are frequently encountered. We herein introduce a novel technique, perichondrial posterior fixation (PPF), to maintain a wide external auditory canal (EAC), to minimize postoperative wound infection due to the smaller dead space and to improve the posterior auricular cosmetic outcome.MethodsA total of 73 patients who underwent CWD tympanomastoidectomy were included. Interventions are CWD tympanomastoidectomy with the PPF technique. Review of the medical records and evaluation of the postoperative size of the meatus and the extent of the cavum conchal cartilage buried within the mastoid cavity by taking digital photographs.ResultsThirty males and 43 females were included and the mean age was 44.1 yr (range, 6 to 66 yr). The mean follow-up duration was 26 months (range, 12 to 56 months). All ears maintained a clean and large external meatus. The posterior auricular cavum conchal cartilage was successfully prevented from being buried into the mastoid cavity in all ears. The extent of cartilage buried into the mastoid cavity was much reduced compared to the conventional technique.ConclusionThe PPF technique, which is a novel meatoplasty technique in CWD tympanomastoidectomy, seems to be effective in maintaining a large external meatus and improving the cosmetic outcome with minimal risk of complications

Intracellular interferons in fish : a unique means to combat viral infection

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