Photon correlation in GaAs self-assembled quantum dots

We report on photon coincidence measurement in a single GaAs self-assembled quantum dot (QD) using a pulsed excitation light source. At low excitation, when a neutral exciton line was present in the photoluminescence (PL) spectrum, we observed nearly perfect single photon emission from an isolated QD at 670 nm wavelength. For higher excitation, multiple PL lines appeared on the spectra, reflecting the formation of exciton complexes. Cross-correlation functions between these lines showed either bunching or antibunching behavior, depending on whether the relevant emission was from a biexciton cascade or a charged exciton recombination.Comment: 5 pages, 3 figure

Treatment of mandibular condyalr osteochondroma

We successfully treated a case of facial asymmetry involved in unilateral mandibular condylar osteochondroma with ipsilateral mandibular condylectomy and contralateral ramus osteotomy. A female, 32-year 11-month of age, had a chief complaint of facial asymmetry which initiated about 10 years ago. A mirror image analysis using a non-contact 3D image scanner revealed that the soft tissue on the deviated side was protruded more than 5.50 mm compared with the non-deviated side. The patinet was diagnosed as facial asymmetry with a skeletal Class III jaw-base relationship caused by unilateral mandibular condylar osteochondroma. After 18 months of preoperative orthodontic treatment, ipsilateral condylectomy and contralateral sagittal split ramus osteotomy were performed. As the results of postoperative orthodontic treatment for 20 months, an ideal occlusion having a Class I molar relationship with an adequate interincisal relationship was achieved. Facial asymmetry and mandibular protrusion were dramatically improved, and the differences between the deviation and non-deviation sides were decreased to less than 1.11 mm. The acceptable occlusion and symmetric face were maintained throughout 1-year retention period. Conclusively, our results indicated the stability after condylectomy without condylar reconstruction in a patient with unilateral condylar osteochondroma

The actual–ideal gap in work–life balance and quality of life among acute care ward nurses

Aims: To describe the current situation of the work–life balance gap among acute care ward nurses and assess its association with quality of life (QOL).Background: Nurses who spend more time at work than on their personal lives are reported to have lower QOL. To capture the actual–ideal work–life balance gap among nurses with different backgrounds, time spent on work, family and private life must be examined.Methods: This cross-sectional study included 228 nurses from 3 Japanese acute care hospitals.Results: Work gap scores and family gap scores for nurses living alone were sig-nificantly higher and lower, respectively, than those for nurses living with family. Moreover, the QOL score decreased with increase in the work–life balance gap for nurses.Conclusions: Nurses living alone had greater work burden than nurses living with family. Conversely, living with family may protect nurses\u27 family lives. The work–life balance gap was associated with QOL.Implications for Nursing Management: Addressing the gap between the actual–ideal proportions in work–life balance is important for improving nurses\u27 QOL and work–life balance. Flexible working options and policy changes may also improve their work–life balance and QOL

LIPUSはミニスクリューインプラント周囲の骨形成を促進する

Miniscrew implants (MSIs) are currently used to provide absolute anchorage in orthodontics; however, their initial stability is an issue of concern. Application of low-intensity pulsed ultrasound (LIPUS) can promote bone healing. Therefore, LIPUS application may stimulate bone formation around MSIs and enhance their initial stability. Aim. To investigate the effect of LIPUS exposure on bone formation after implantation of titanium (Ti) and stainless steel (SS) MSIs. Methods. MSIs made of Ti-6Al-4V and 316L SS were placed on rat tibiae and treated with LIPUS. The bone morphology around MSIs was evaluated by scanning electron microscopy and threedimensional micro-computed tomography. MC3T3-E1 cells cultured on Ti and SS discs were treated with LIPUS, and the temporary expression of alkaline phosphatase (ALP) was examined. Results. Bone-implant contact increased gradually from day 3 to day 14 after MSI insertion. LIPUS application increased the cortical bone density, cortical bone thickness, and cortical bone rate after implantation of Ti and SS MSIs (P < 0.05). LIPUS exposure induced ALP upregulation in MC3T3- E1 cells at day 3 (P < 0.05). Conclusion. LIPUS enhanced bone formation around Ti and SS MSIs, enhancing the initial stability of MSIs

Characterization of Clonal Polyp Strains Established from Aurelia sp. Inhabiting the Seto Inland Sea of Japan

ミズクラゲ(Aurelia sp.)の生活環の中で，ポリプからストロビラを経てエフィラに形態変化する過程はストロビレーションと呼ばれる。ストロビレーションの分子機構の解明に向けて分子生物学的および生化学的研究を進めるために，瀬戸内海産のミズクラゲからポリプのクローン系統を7株確立した。実験室内でストロビレーションを誘導する条件を検討した結果，これらのクローン系統は，25℃から10℃への低温処理によって32- 42日でストロビレーションを開始し，indomethacin (25μM)の投与によって25℃条件下で4-8日でストロビレーションを開始した。また，短期間だけ低温処理をおこなう飼育実験の結果，ストロビレーションは一旦開始すると低温条件下でなくても正常に進行し完了することが明らかになった。さらに，分子系統解析の結果，今回確立したクローン系統がAurelia sp.1(Dawson et al., 2005)であることが示唆された。In the life cycle of Aurelia sp., the transition from polyp to strobila/ephyra is called“strobilation”. To study the molecular mechanisms of strobilation with molecular biological and biochemical approaches, we established 7 clonal polyp strains from Aurelia sp. inhabiting the Seto Inland Sea of Japan. In laboratory condition, the clonal strains started strobilation in 32 - 42 days by a temperature change from 25˚C to 10˚C, or in 4 - 8 days at 25˚C by administration of indomethacin (25 μM). The experiments of short-term low-temperature treatments revealed that strobilation proceeded to the end independently of temperature after strobilation had been initiated. Further, molecular phylogenetic analysis suggested that the clonal strains could be Aurelia sp. 1 (Dawson et al., 2005).本研究は，平成20年度広島大学後援会・教育研究一般助成および平成20年度広島大学大学院生物圏科学研究科・研究科長裁量経費研究助成の支援のもとで実施されたものである

Picosecond Nonlinear Relaxation of Photoinjected Carriers in a Single GaAs/AlGaAs Quantum Dot

Photoemission from a single self-organized GaAs/AlGaAs quantum dot (QD) is temporally resolved with picosecond time resolution. The emission spectra consisting of the multiexciton structures are observed to depend on the delay time and the excitation intensity. Quantitative agreement is found between the experimental data and the calculation based on a model which characterizes the successive relaxation of multiexcitons. Through the analysis we can determine the carrier relaxation time as a function of population of photoinjected carriers. Enhancement of the intra-dot carrier relaxation is demonstrated to be due to the carrier-carrier scattering inside a single QD.Comment: 4 pages, 4 figures, to be published in Phys. Rev. B, Rapid

PTH and LIPUS on Osteoporotic Fracture Healing

Osteoporotic fracture has become a major public health problem, and until today, the treatments available are not satisfactory. While there is growing evidence to support the individual treatment of parathyroid hormone (PTH) administration and low-intensity pulsed ultrasound (LIPUS) exposure as respectively systemic and local therapies during osteoporotic fracture healing, their effects have not yet been investigated when introduced concurrently. This study aimed to evaluate the effects of combined treatment with PTH (1–34) and LIPUS on fracture healing in ovariectomized (OVX) rats. Thirty-two, 12-week-old female Sprague–Dawley rats were OVX to induce osteoporosis. After 12 weeks, the rats underwent surgery to create bilateral mid-diaphyseal fractures of proximal tibiae. All animals were randomly divided into 4 groups (n = 8 for each): control group as placebo, PTH group, LIPUS group, and combined group. PTH group had PTH administration at a dose of 30 lg/kg/day for 3 days/week for 6 weeks. LIPUS group received ultrasound 5 days/week for 20 min/day for 6 weeks and combined group had both PTH administration and LIPUS exposure for 6 weeks. Fracture healing was observed weekly by anteroposterior radiography and micro-CT. Five weeks after the fracture, the tibia were harvested to permit histological assessments and at week 6, for mechanical property of the fracture callus. Micro-CT showed that the PTH and combined groups exhibited significantly higher BMD and trabecular bone integrity than control group at weeks 4–6. Radiography, fracture healing score and mean callus area indicated that the combined group revealed better healing processes than the individual groups. Mechanically, bending moment to failure was significantly higher in LIPUS, PTH and combined groups than in control group. These data suggest that the combined treatment of PTH and LIPUS have been shown to accelerate fracture bone healing and enhance bone properties rather than single agent therapy, and may be considered as a treatment remedy for fracture healing in postmenopausal osteoporosis

Screening for resistance against Pseudomonas syringae in rice-FOX Arabidopsis lines identified a putative receptor-like cytoplasmic kinase gene that confers resistance to major bacterial and fungal pathogens in Arabidopsis and rice

Approximately 20 000 of the rice-FOX Arabidopsis transgenic lines, which overexpress 13 000 rice full-length cDNAs at random in Arabidopsis, were screened for bacterial disease resistance by dip inoculation with Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). The identities of the overexpressed genes were determined in 72 lines that showed consistent resistance after three independent screens. Pst DC3000 resistance was verified for 19 genes by characterizing other independent Arabidopsis lines for the same genes in the original rice-FOX hunting population or obtained by reintroducing the genes into ecotype Columbia by floral dip transformation. Thirteen lines of these 72 selections were also resistant to the fungal pathogen Colletotrichum higginsianum. Eight genes that conferred resistance to Pst DC3000 in Arabidopsis have been introduced into rice for overexpression, and transformants were evaluated for resistance to the rice bacterial pathogen, Xanthomonas oryzae pv. oryzae. One of the transgenic rice lines was highly resistant to Xanthomonas oryzae pv. oryzae. Interestingly, this line also showed remarkably high resistance to Magnaporthe grisea, the fungal pathogen causing rice blast, which is the most devastating rice disease in many countries. The causal rice gene, encoding a putative receptor-like cytoplasmic kinase, was therefore designated as BROAD-SPECTRUM RESISTANCE 1. Our results demonstrate the utility of the rice-FOX Arabidopsis lines as a tool for the identification of genes involved in plant defence and suggest the presence of a defence mechanism common between monocots and dicots

低出力パルス超音波は自己免疫疾患での唾液腺炎による唾液分泌低下を改善する

Introduction: Low-intensity pulsed ultrasound (LIPUS) has been known to promote bone healing by nonthermal effects. In recent studies, LIPUS has been shown to reduce inflammation in injured soft tissues. Xerostomia is one of the most common symptoms in Sjögren syndrome (SS). It is caused by a decrease in the quantity or quality of saliva. The successful treatment of xerostomia is still difficult to achieve and often unsatisfactory. The aim of this study is to clarify the therapeutic effects of LIPUS on xerostomia in SS. Methods: Human salivary gland acinar (NS-SV-AC) and ductal (NS-SV-DC) cells were cultured with or without tumor necrosis factor-α (TNF-α; 10 ng/ml) before LIPUS or sham exposure. The pulsed ultrasound signal was transmitted at a frequency of 1.5 MHz or 3 MHz with a spatial average intensity of 30 mW/cm2 and a pulse rate of 20 %. Cell number, net fluid secretion rate, and expression of aquaporin 5 (AQP5) and TNF-α were subsequently analyzed. Inhibitory effects of LIPUS on the nuclear factor κB (NF-κB) pathway were determined by Western blot analysis. The effectiveness of LIPUS in recovering salivary secretion was also examined in a MRL/MpJ/lpr/lpr (MRL/lpr) mouse model of SS with autoimmune sialadenitis. Results: TNF-α stimulation of NS-SV-AC and NS-SV-DC cells resulted in a significant decrease in cell number and net fluid secretion rate (p < 0.01), whereas LIPUS treatment abolished them (p < 0.05). The expression changes of AQP5 and TNF-α were also inhibited in LIPUS treatment by blocking the NF-κB pathway. Furthermore, we found that mRNA expression of A20, a negative feedback regulator, was significantly increased by LIPUS treatment after TNF-α or interleukin 1β stimulation (NS-SV-AC, p < 0.01; NS-SV-DC, p < 0.05). In vivo LIPUS exposure to MRL/lpr mice exhibited a significant increase in both salivary flow and AQP5 expression by reducing inflammation in salivary glands (p < 0.01). Conclusions: These results suggest that LIPUS upregulates expression of AQP5 and inhibits TNF-α production. Thus, LIPUS may restore secretion by inflamed salivary glands. It may synergistically activate negative feedback of NF-κB signaling in response to inflammatory stimulation. Collectively, LIPUS might be a new strategic therapy for xerostomia in autoimmune sialadenitis with SS

Financial revolution in republican China during 1900–37: a survey and a new interpretation

This paper surveys the phenomenal transformation of banking and finance, public debt, and monetary regimes during 1900–37, a period of great political instability in Chinese history. To understand why growth in these strategic sectors occurred, I highlight the role of the institutional nexus of Western treaty ports (with Shanghai being the most important) and China Maritime Customs service, a relatively autonomous tax bureaucracy. My new interpretation on the importance of this mechanism sheds new light on the role of Chinese political institutions, the impact of the West and the ongoing Great Divergence debate