Graphene thermal infrared emitters integrated into silicon photonic waveguides

Cost-efficient and easily integrable broadband mid-infrared (mid-IR) sources would significantly enhance the application space of photonic integrated circuits (PICs). Thermal incandescent sources are superior to other common mid-IR emitters based on semiconductor materials in terms of PIC compatibility, manufacturing costs, and bandwidth. Ideal thermal emitters would radiate directly into the desired modes of the PIC waveguides via near-field coupling and would be stable at very high temperatures. Graphene is a semi-metallic two-dimensional material with comparable emissivity to thin metallic thermal emitters. It allows maximum coupling into waveguides by placing it directly into their evanescent fields. Here, we demonstrate graphene mid-IR emitters integrated with photonic waveguides that couple directly into the fundamental mode of silicon waveguides designed for a wavelength of 4,2 {\mu}m relevant for CO${_2}$ sensing. High broadband emission intensity is observed at the waveguide-integrated graphene emitter. The emission at the output grating couplers confirms successful coupling into the waveguide mode. Thermal simulations predict emitter temperatures up to 1000{\deg}C, where the blackbody radiation covers the mid-IR region. A coupling efficiency {\eta}, defined as the light emitted into the waveguide divided by the total emission, of up to 68% is estimated, superior to data published for other waveguide-integrated emitters.Comment: 24 page

Recent advances in the treatment of Kawasaki disease

Kawasaki disease (KD) is acute systemic vasculitis that occurs mainly in infants and children under 5 years of age. The etiology of KD remains unknown. KD is liable to be complicated by coronary artery lesions (CALs), which develop in approximately 15–25% of untreated KD children and in approximately 5% of KD children after intravenous immunoglobulin (IVIG) therapy. A single high dose of IVIG (2 g/kg) is the gold standard therapy in the acute stage of KD. However, approximately 8–38% of children are unresponsive to initial IVIG treatment and at increased risk for CAL development. Anti-inflammatory high doses of aspirin are recommended in conjunction with IVIG, but our study demonstrated that there is no evidence of efficacy in preventing CAL development. The usefulness of steroids in initial therapy for KD or treatment of IVIG-resistant patients is not well established. Other immunosuppressive therapies, including infliximab, have been used in the treatment of refractory KD, but merit additional investigation. Subclinical atherosclerosis may develop early in KD patients, which makes early initiation of therapy to improve chronic inflammation an important issue. Future multicenter studies may help to define the optimal management of KD patients

Idiopathic Dilated Cardiomyopathy in Children: A Single Medical Center's Experience

The prognosis of patients with idiopathic dilated cardiomyopathy (DCM) is poor. Most patients die while waiting for cardiac transplantation because of the small number of donors in Taiwan. The purpose of this study was to review our experience with pediatric patients diagnosed with idiopathic DCM and attempt to discover prognostic factors. Methods: Eighteen patients with idiopathic DCM presenting between 1990 and 2004 were identified. They were classified into 2 groups according to outcome: group 1 comprised 13 patients who died; group 2 comprised 5 who survived. Clinical findings and laboratory investigations were compared between the 2 groups. Results: The age at initial diagnosis for the 18 patients (11 males, 7 females) ranged from fetus to 13 years (median, 3 months). The follow-up period ranged from 12 days to 44 months (median, 7 months) in group 1, and from 1 to 48 months (median, 39 months) in group 2. Of the 18 patients, 13 (72%) died: 11 died from severe heart failure while waiting for cardiac transplantation. The cumulative survival rate was 50% at 1 year and 28% at 4 years. The presence of arrhythmia and low left ventricular ejection fraction were predictive of a poor outcome. Conclusion: The diagnosis of idiopathic DCM in children is associated with a generally poor prognosis. The lack of available donors results in significant mortality for pediatric patients awaiting transplantation. Advocating organ donation to increase the size of the organ donor pool is needed to significantly reduce the mortality rate in such patients

Radiofrequency Catheter Ablation of Coexistent Idiopathic Left Ventricular Tachycardia and Atrioventricular Nodal Reentrant Tachycardia

A healthy 15-year-old male patient presented with a 6-month history of recurrent attacks of palpitations. On multiple emergency room visits, a sustained wide QRS complex tachycardia with a right bundle branch block and northwest axis deviation was documented. The tachycardia was not terminated by intravenous adenosine, but was suppressed with intravenous verapamil. There was no evidence of structural heart disease, myocarditis, long QT syndrome, or electrolyte imbalance after a series of standard examinations. Idiopathic left ventricular tachycardia (ILVT) was suspected. Electrophysiologic studies revealed 2 inducible tachycardias, which were shown to represent atrioventricular nodal reentrant tachycardia (AVNRT) and ILVT. Transformation from AVNRT to ILVT occurred spontaneously following atrial pacing. Successful ablation of ILVT and the slow atrioventricular nodal pathway resulted in cure of the double tachycardia

High serum DcR3 levels are associated with the occurrence of peritonitis in patients receiving chronic peritoneal dialysis

Background: Peritoneal dialysis (PD)-related peritonitis is a serious complication that typically leads to hospitalization, catheter loss, and even mortality. Previous studies of the risk factors for peritonitis are discordant. To date, no biomarker associated with PD-related peritonitis has been investigated. However, it has been shown that serum decoy receptor 3 (DcR3) is a valuable marker in predicting the outcome of several inflammatory diseases. The aim of this study was to investigate whether serum DcR3 is a predictor of peritonitis in chronic PD patients. Methods: We conducted a prospective cohort study of PD patients in the PD unit of a tertiary referral center from March 1 to November 30, 2007, and followed up until December 31, 2009. Clinical and laboratory parameters were recorded and serum DcR3 was measured to assess risk factors for developing PD-related peritonitis. Results: A total of 77 patients (38 men and 39 women; mean age 58 ± 13 years) were enrolled in this study. The average time on PD was 24.5 months and 46 patients (60%) were diabetic. The mean follow-up duration was 499 ± 17 days. The rate of peritonitis incidence was 0.17 episodes per patient-year. Baseline serum DcR3 in 77 patients was 1.94 ± 1.23 ng/mL. Kaplan–Meier survival analysis showed that patients with serum DcR3 > 1.8 ng/mL had a higher risk of peritonitis than those with serum DcR3 < 1.8 ng/mL (p = 0.016). The Cox proportional hazard model further showed that high serum DcR3 (>1.8 ng/mL) was an independent risk factor for subsequent peritonitis (hazard ratio 3.61, 95% CI 1.17–11.08; p = 0.03). Conclusion: Serum DcR3 was associated with increased risk of PD-related peritonitis

Synthesis and Antibacterial Activities of Novel 4-Hydroxy-7-hydroxy- and 3-Carboxycoumarin Derivatives

Coumarin derivatives are used as fluorescent dyes and medicines. They also have some notable physiological effects, including the acute hepatoxicity and carcinogenicity of certain aflatoxins, the anticoagulant action of dicoumarol, and the antibiotic activity of novobicin and coumerymycin A1. Because the number of drug resistant strains is increasing at present, the synthesis of new antibacterial compounds is one of the critical methods for treating infectious diseases. Therefore, a series of coumarin-substituted derivatives, namely 4-hydroxy- and 7-hydroxycoumarins, and 3-carboxycoumarins were synthesized. 4-Hydroxycoumarin derivatives 4a–c underwent rearrangement reactions. Both 4- and 7-hydroxycoumarins were treated with activated aziridines which produced series of ring-opened products 7, 8, 10, and 11. 3-Carboxy-coumarin amide dimer derivatives 14–21 were prepared by reacting aliphatic alkylamines and alkyldiamines with PyBOP and DIEA. In this study, we use a new technique called modified micro-plate antibiotic susceptibility test method (MMAST), which is more convenient, more efficient, and more accurate than previous methods and only a small amount of the sample is required for the test. Some of the compounds were produced by reactions with acid anhydrides and demonstrated the ability to inhibit Gram-positive microorganisms. The dimer derivatives displayed lower antibacterial activities

Reappraisal of the Prostaglandin E1 Dose for Early Newborns with Patent Ductus Arteriosus-Dependent Pulmonary Circulation

The usual initial dose of prostaglandin E1 (PGE1) for ductal-dependent congenital heart disease (CHD) is 50–100 ng/kg/minute. The aim of this study was to review our experience of a low initial dose of PGE1 treatment in early newborns with congenital heart disease and patent ductus arteriosus (PDA)-dependent pulmonary flow. Methods: We reviewed the clinical data of 33 newborns with CHD and PDA-dependent pulmonary circulation who were admitted from January 2005 to December 2010. Clinical parameters were collected, including, PGE1 dosage, oxygenation condition, vital signs, and other related clinical parameters during admission. Echocardiography was employed to assess the status of the PDA as clinically indicated. Results: Thirty-three newborns, including 17 males and 16 females, with CHD and PDA-dependent pulmonary circulation were enrolled in the study. Their mean age was 2.9 ± 5.1 (within the range of 1–26) days with a median of 1.0 day. Among the 33 cases, 25 were diagnosed with pulmonary atresia and eight with critical pulmonary stenosis. Twenty-five of our patients were treated with the initial low-dosage regimen of 20.0 ± 7.4 ng/kg/minute in our neonatal intensive care unit. None of these 25 patients with had significant apnea necessitating intubation and none had hypotension, fever, convulsion or cortical hyperostosis. Three of the eight patients who were treated with high-dose PGE1 (39 ± 13.2 ng/kg/minute) before referral to our unit had apnea and intubation after PGE1 use. All patients had adequate PDA patency with a low maintenance dose of 10.5 ± 5.3 ng/kg/minute before operation under our protocol. Conclusion: In our experience, adequate PDA flows in early newborns with CHD and PDA-dependent pulmonary circulation could be achieved at a much lower dose than recommended in the literature. The lower dose of PGE1 also causes much fewer complications, such as apnea, fever, and hypotension. For early newborns with CHD and PDA-dependent pulmonary circulation, treatment with a lower initial dose of PGE1 of 20 ng/kg/minute and a maintenance dose of 10 ng/kg/minute is recommended