Temperature Dependence of Highly Excited Exciton Polaritons in Semiconductor Microcavities

Observations of polariton condensation in semiconductor microcavities suggest that polaritons can be exploited as a novel type of laser with low input-power requirements. The low-excitation regime is approximately equivalent to thermal equilibrium, and a higher excitation results in more dominant nonequilibrium features. Although standard photon lasing has been experimentally observed in the high excitation regime, e-h pair binding can still remain even in the high-excitation regime theoretically. Therefore, the photoluminescence with a different photon lasing mechanism is predicted to be different from that with a standard photon lasing. In this paper, we report the temperature dependence of the change in photoluminescence with the excitation density. The second threshold behavior transited to the standard photon lasing is not measured at a low-temperature, high-excitation power regime. Our results suggest that there may still be an electron--hole pair at this regime to give a different photon lasing mechanism.Comment: 25 pages, 11 figures, to appear in J. Phys. Soc. Jp

Earthquake-Induced Potentiation of Acute Risk Factors in Hypertensive Elderly Patients: Possible Triggering of Cardiovascular Events After a Major Earthquake

AbstractObjectives. We sought to investigate the potentiation of acute risk factors after the Hanshin-Awaji earthquake (7.2 on the Richter scale).Background. The frequency of cardiovascular events increases just after a major earthquake, but the causative factors have not been fully investigated.Methods. We studied the changes in cardiovascular risk factors in 42 elderly outpatients with well-controlled hypertension living near the epicenter (Awaji-Hokudan districts) 7 to 14 days after the earthquake when the major felt-aftershocks persisted. They all experienced the highest stress grading of 6 (catastrophic stress) according to the DSM-III-R. To study the hemostatic profile and endothelial cell state, we measured the blood pressure (BP), hematocrit and lipid profiles as well as fibrinogen, a marker of fibrin turnover (d-dimer), fibrinolytic factors (plasmin-alpha2–plasmin inhibitor complex [PIC], tissue-type plasminogen activator [t-PA] antigen and t-PA inhibitor [PAI] activity) and an endothelial cell-derived marker (von Willebrand factor [vWF]).Results. Systolic and diastolic blood pressures and other variables increased after the earthquake. Before and after the earthquake, the median (25th to 75th percentiles) systolic BP was 152 (range 142 to 164) and 170 mm Hg (range 161 to 178), respectively (p < 0.0001), and the diastolic BP was 83 (range 79 to 88) and 91 mm Hg (range 84 to 96), respectively (p < 0.0001). Of blood viscosity determinants, hematocrit was 38.1% (range 40.7% to 35.9%) and 39.7% (range 42.9% to 38.3%), respectively (p < 0.001), and fibrinogen 316 (range 272 to 360) and 335 mg/dl (range 307 to 391), respectively (p < 0.05). Von Willebrand factor was 128% (range 74% to 148%) and 148% (range 100% to 178%), respectively (p < 0.01); d-dimer was 410 (range 285 to 633) and 560 ng/ml (range 391 to 888), respectively (p < 0.0001); and PIC was 0.74 (range 0.58 to 0.91) and 0.75 μg/ml (range 0.58 to 1.1), respectively (p < 0.05). In contrast, lipid profiles did not change after the quake. When the patients were classified into the high stress and moderate stress groups according to the degrees of damage to their house and injury to family members, the levels of fibrinogen, vWF, PIC and t-PA antigen were increased only in the former group, whereas BP, hematocrit and d-dimer levels were increased in both groups. These abnormalities of acute risk factors, except for vWF, were transient and decreased to prequake levels by 4 to 6 months after the quake.Conclusions. Earthquake-induced stress seems to induce transient increases in BP, blood viscosity determinants and fibrin turnover and to prolong endothelial cell stimulation. The potentiation of these acute risk factors might contribute to the occurrence of cardiovascular events just after a major earthquake in elderly subjects with hypertension.(J Am Coll Cardiol 1997;29:926–33)© 1997 by the American College of Cardiolog

Comparison of Protein Profiles of Gingival Crevicular Fluids Collected from Incisors, Canines, and Molars

Many studies have shown that gingival crevicular fluid （GCF） reflects the inflammatory state of local periodontal tissues. GCF has been collected from several types of teeth in previous studies. However, there is no report that characterizes GCF by the type of tooth. In the present study, the protein profiles of GCF from different sites were comprehensively compared with each other. GCF was sampled from six healthy adult men （21-31 years old） with healthy periodontal tissues. Three separate GCF samples were collected at the maxillary central incisor, canine, and first molar of each individual. The protein profiles of GCF were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis and liquid chromatogram-tandem mass spectrometry （LC-MS/MS）. The band patterns on the sodium dodecyl sulfate polyacrylamide gel electrophoresis from the set of three GCF samples from each individual were similar, regardless of the type of tooth. The proteins contained in each band were identified by LC-MS/MS analysis, and they were found to be the same among the three GCF samples. A comprehensive and quantitative analysis of proteins in the GCF samples was performed by LC-MS/MS using isobaric tag labeling. In total, 86 proteins were identified in GCF. A small number of proteins were increased or decreased in GCF from the first molars compared with the other types of teeth in one or two individuals. However, overall, no proteins were found to exhibit a reproducibly different composition in any of the individuals. These analyses show that the protein profiles of GCF in healthy periodontal tissues are similar, regardless of the type of tooth

Deoxofluorination of graphite oxide with sulfur tetrafluoride

In this study, deoxofluorination of graphite oxide (GO) using sulfur tetrafluoride (SF₄) at a temperature below the decomposition temperature of GO (∼200 °C) was investigated for the first time with and without HF catalysis. At 25 °C, the reaction proceeds only at high SF₄ pressures (≥8 atm) when not catalyzed by HF and at 1 atm SF₄ under the catalysis of HF. The degree of fluorination increases at higher temperatures and SF₄ pressures. Hydroxy and carbonyl groups are replaced by fluorine following this reaction, and SF₄ and SOF₂ are introduced into the product, while the epoxy groups do not react. SF₄ and SOF₂ in the products are removed by washing with water. The obtained product is less hygroscopic than pristine GO owing to the hydrophobicity of the fluorine atom. The interlayer separation of the product is increased after deoxofluorination despite the smaller size of fluorine than the sizes of the oxygen-containing functional groups. When compared with direct fluorination using elemental fluorine, deoxofluorination using SF₄ has the advantages of high reactivity with hydroxy groups and the preservation of the carbon skeleton, and the reaction results in the formation of graphite oxyfluoride

Discharge Characteristic of Fluorinated Graphene-like Graphite as a Cathode of Lithium Primary Battery

The 64th special issue "Frontiers of Carbon Materials"Graphene-like graphite prepared by heating graphite oxide under vacuum at 800 degrees C was fluorinated by elemental fluorine in the presence of HF at room temperature. The interlayer spacing of the resulting material was 0.639 nm and it showed CxF type characteristics. The fluorine content of it (x = 1.7) was higher than that obtained from natural graphite (x = 2.3). The discharge capacity of it as a cathode of lithium primary battery reached 940 mAhg(-1) at a low current density, which was 50% larger than the theoretical capacity based on the 100% discharge of fluorine

Pathologically Proven Intraocular Infiltration With Adult T-Cell Leukemia/Lymphoma: Two New Cases With Either Vitreous Opacity or Aqueous Hypopyon and Literature Review of 16 Cases

This study reported 2 new patients and 16 historical cases with pathologically proven intraocular infiltration with adult T-cell leukemia and lymphoma (ATLL) to know the timing of intraocular infiltration in the disease course. The first case was a 67-year-old woman who developed bilateral vitreous opacity about half a year after the onset of acute type of ATLL that had been unresponsive to chemotherapy. She underwent vitrectomy combined with cataract surgery in both eyes. She had bilateral optic disc atrophy and localized retinal white infiltrates in both eyes. Cytological examination of vitreous aspirates demonstrated medium-sized cells with aberrant flower-like convoluted nuclei, positive for CD3, and thus indicative of T-cells. The second case was a 38-year-old man who was diagnosed acute type of ATLL at the presentation of acute kidney injury. About half a year after initial chemotherapy and allogeneic hematopoietic stem cell transplantation, he developed aqueous hypopyon in the right eye, concurrent with cutaneous and central nervous system relapse. Aqueous tap disclosed class V abnormal cells. The aqueous “pseudohypopyon” resolved in response to another round of chemotherapy with mogamulizumab. In review of 18 patients, intraocular infiltration with ATLL was diagnosed by vitrectomy in 9, aqueous tap in 3, chorioretinal biopsy in 3, and autopsy in 3. The intraocular infiltration developed concurrently with systemic diagnosis of ATLL in 5 patients, but developed later after chemotherapy in 13. In conclusion, intraocular infiltration with ATLL appears rare, and pathological diagnosis by vitrectomy and aqueous tap would help determine therapeutic plan in relapse after chemotherapy

One-dimension visco-elastic modelling of wood in the process of formation to clarify the Hygrothermal Recovery behavior of tension wood

International audienceWood production on stem by deposit of concentric layers on its periphery are going along with the setting up of growth stress. Growth stress has two origins: (1) loading due to weight of the structure is applied progressively when the tree is growing; (2) cell maturation, which happened at the end of the deposit of a new layer, causes an expansion, called maturation deformation, which can’t happen freely due to the previous layer and lead to the creation of initial growth stress [1]. The growth stress can be released during cutting and also during hygrothermal treatment (HT), it can be called Hygrothermal Recovery (HTR) [2]

Field-orientation dependence of quantum phase transitions in the S=1/2 triangular-lattice antiferromagnet Ba3_3CoSb2_2O9_9

Ba$_3$CoSb$_2$O$_9$ approximates the two-dimensional spin-1/2 triangular-lattice Heisenberg antiferromagnet. This compound displays magnetic-field-induced quantum phase transitions, including the 1/3-magnetization-plateau, but its magnetization processes for the magnetic field $H$ parallel and perpendicular to the $c$ axis are different due to the weak easy-plane anisotropy and the weak interlayer antiferromagnetic exchange interaction. To elucidate how the quantum phase transitions change between these two field directions, we measured the field-angle dependence of the magnetization process in Ba$_3$CoSb$_2$O$_9$ using pulsed high magnetic fields. We compared obtained magnetic field-field angle phase diagram with those obtained by the large-size cluster mean-field method combined with a scaling scheme and the semiclassical theory. We also found a narrow 1/3-magnetization plateau and a high-field transition with a small magnetization jump for $H\,{\parallel}\,c$, not observed in the previous studies.Comment: 8 pages, 7 figures, to appear in Phys. Rev.