Moving boundary and photoelastic coupling in GaAs optomechanical resonators

Chip-based cavity optomechanical systems are being considered for applications in sensing, metrology, and quantum information science. Critical to their development is an understanding of how the optical and mechanical modes interact, quantified by the coupling rate $g_{0}$. Here, we develop GaAs optomechanical resonators and investigate the moving dielectric boundary and photoelastic contributions to $g_{0}$. First, we consider coupling between the fundamental radial breathing mechanical mode and a 1550 nm band optical whispering gallery mode in microdisks. For decreasing disk radius from $R=5$ $\mu$m to $R=1$ $\mu$m, simulations and measurements show that $g_{0}$ changes from being dominated by the moving boundary contribution to having an equal photoelastic contribution. Next, we design and demonstrate nanobeam optomechanical crystals in which a $2.5$ GHz mechanical breathing mode couples to a 1550 nm optical mode predominantly through the photoelastic effect. We show a significant (30 $\%$) dependence of $g_{0}$ on the device's in-plane orientation, resulting from the difference in GaAs photoelastic coefficients along different crystalline axes, with fabricated devices exhibiting $g_{\text{0}}/2\pi$ as high as 1.1 MHz for orientation along the [110] axis. GaAs nanobeam optomechanical crystals are a promising system which can combine the demonstrated large optomechanical coupling strength with additional functionality, such as piezoelectric actuation and incorporation of optical gain media

Association of erythrocyte n-3 polyunsaturated fatty acids with incident type 2 diabetes in a Chinese population

Summary Background & aims The association between circulating n-3 polyunsaturated fatty acid (PUFA) biomarkers and incident type 2 diabetes in Asian populations remains unclear. We aimed to examine the association of erythrocyte n-3 PUFA with incident type 2 diabetes in a Chinese population. Methods A total of 2671 participants, aged 40–75 y, free of type 2 diabetes at baseline, were included in the present analysis. Incident type 2 diabetes cases (n = 213) were ascertained during median follow-up of 5.6 years. Baseline erythrocyte fatty acids were measured by gas chromatography. We used multivariable Cox regression models to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of type 2 diabetes across quartiles of erythrocyte n-3 PUFA. Results After adjustment for potential confounders, HRs (95% CIs) of type 2 diabetes were 0.68 (0.47, 1.00), 0.77 (0.52, 1.15), and 0.63 (0.41, 0.95) in quartiles 2–4 of docosapentaenoic acid (C22:5n-3) (P-trend = 0.07), compared with quartile 1; and 1.08 (0.74, 1.60), 1.03 (0.70, 1.51), and 0.57 (0.38, 0.86) for eicosapentaenoic acid (C20:5n-3) (P-trend = 0.007). No association was found for docosahexaenoic acid (C22:6n-3) or alpha-linolenic acid (C18:3n-3). Conclusions Erythrocyte n-3 PUFA from marine sources (C22:5n-3 and C20:5n-3), as biomarkers of dietary marine n-3 PUFA, were inversely associated with incident type 2 diabetes in this Chinese population. Future prospective investigations in other Asian populations are necessary to confirm our findings

JNK pathway is involved in the inhibition of inflammatory target gene expression and NF-kappaB activation by melittin

<p>Abstract</p> <p>Background</p> <p>Bee venom therapy has been used to treat inflammatory diseases including rheumatoid arthritis in humans and in experimental animals. We previously found that bee venom and melittin (a major component of bee venom) have anti-inflammatory effect by reacting with the sulfhydryl group of p50 of nuclear factor-kappa B (NF-κB) and IκB kinases (IKKs). Since mitogen activated protein (MAP) kinase family is implicated in the NF-κB activation and inflammatory reaction, we further investigated whether activation of MAP kinase may be also involved in the anti-inflammatory effect of melittin and bee venom.</p> <p>Methods</p> <p>The anti-inflammatory effects of melittin and bee venom were investigated in cultured Raw 264.7 cells, THP-1 human monocytic cells and Synoviocytes. The activation of NF-κB was investigated by electrophoretic mobility shift assay. Nitric oxide (NO) and prostaglandin E₂(PGE₂) were determined either by Enzyme Linked Immuno Sorbent Assay or by biochemical assay. Expression of IκB, p50, p65, inducible nitric oxide synthetase (iNOS), cyclooxygenase-2 (COX-2) as well as phosphorylation of MAP kinase family was determined by Western blot.</p> <p>Results</p> <p>Melittin (0.5–5 μg/ml) and bee venom (5 and 10 μg/ml) inhibited lipopolysaccharide (LPS, 1 μg/ml) and sodium nitroprusside (SNP, 200 μM)-induced activation of c-Jun NH2-terminal kinase (JNK) in RAW 264.7 cells in a dose dependent manner. However, JNK inhibitor, anthra [1,9-cd]pyrazole-6 (2H)-one (SP600215, 10–50 μM) dose dependently suppressed the inhibitory effects of melittin and bee venom on NF-κB dependent luciferase and DNA binding activity via suppression of the inhibitory effect of melittin and bee venom on the LPS and SNP-induced translocation of p65 and p50 into nucleus as well as cytosolic release of IκB. Moreover, JNK inhibitor suppressed the inhibitory effects of melittin and bee venom on iNOS and COX-2 expression, and on NO and PGE₂generation.</p> <p>Conclusion</p> <p>These data show that melittin and bee venom prevent LPS and SNP-induced NO and PGE₂production via JNK pathway dependent inactivation of NF-κB, and suggest that inactivation of JNK pathways may also contribute to the anti-inflammatory and anti-arthritis effects of melittin and bee venom.</p

Kimura's Disease Involving the Ipsilateral Face and Extraocular Muscles

Kimura's disease (KD) is a rare, chronic inflammatory disorder, which is characterized by tumor-like masses mainly located in the head and neck region. Extraocular muscle involvement in KD is uncommon. We report a case of KD that involved both the extraocular muscles and buccal area. A 13-year-old male presented to our clinic with a two-year history of exophthalmos of the left eye and facial swelling. Facial CT and MRI showed a 1.5 × 1.5 cm2 soft tissue mass located at the left masticator and buccal area, exophthalmos of the left eye, and diffuse thickening of the left extraocular muscles. We performed a lateral rectus muscle incisional biopsy of the left eye. Oral methylprednisolone therapy was initiated and tapered following the incisional biopsy

Microglandular Adenosis

Microglandular adenosis (MGA) of the breast is a very rare and benign proliferative lesion. Most patients complain of a palpable breast mass that may arouse a clinical suspicion of breast cancer. Histopathologically, it is hard to distinguish MGA from breast cancer because of the lack of a myoepithelial layer and infiltrative proliferation. Several studies have reported a strong relationship between MGA and carcinoma arising in MGA, so the mass should be excised completely in cases of MGA determined from a core needle biopsy rather than observation. A 72-years-old woman presented with a palpable breast mass. On physical examination, a mass was palpable in the right upper outer quadrant area and somewhat fixed to the surrounding tissues and pectoralis major muscle. We could not detect any mass or dense lesion on mammography because of a grade 4 dense breast. Ultrasonographic findings revealed a low echoic lesion with indistinct margins. The result of a core needle biopsy was MGA, which was confirmed by excision. We report one case of MGA, which was believed to breast cancer clinically

Heart Transplantation in Pediatric Patients: Twelve-Year Experience of the Asan Medical Center

Heart transplantation is a standard treatment for end-stage heart disease. Pediatric heart transplantation, however, is not frequently performed due to the shortage of pediatric heart donors. This is the first report of pediatric heart transplantation in Korea. Our retrospective study included 37 patients younger than 18 yr of age who underwent heart transplantation at Asan Medical Center between August 1997 and April 2009. Preoperative diagnosis was either cardiomyopathy (n = 29, 78.3%) or congenital heart disease (n = 8, 22.7%). Mean follow up period was 56.9 ± 44.6 months. There were no early death, but 7 late deaths (7/37, 18.9%) due to rejection after 11, 15, 41 months (n = 3), infection after 5, 8, 10 months (n = 3), suspicious ventricular arrhythmia after 50 months (n = 1). There was no significant risk factor for survival. There were 25 rejections (25/37, 67.6%); less than grade II occurred in 17 patients (17/25, 68%) and more than grade II occurred in 8 patients (8/25, 32%). Actuarial 1, 5, and 10 yr survival was 88.6%, 76.8%, and 76.8%. Our midterm survival of pediatric heart transplantation showed excellent results. We hope this result could be an encouraging message to do more pediatric heart transplantation in Korean society