Synthesis of Bis(<em>N</em>,<em>N</em>-diethyl)aniline-Based, Nonlinear, Optical Chromophores with Increased Electro-Optic Activity by Optimizing the Thiolated Isophorone Bridge

Six nonlinear, optical chromophores, Z1–Z6, based on the bis(N,N-diethyl)aniline-derived donor and thiolated isophorone bridge, were designed and synthesized. The bis(N,N-diethyl)aniline-derived donor was applied in a chromophore with thiolated isophorone as an electron bridge for the first time. In particular, the bridge parts of chromophores Z2–Z6 were modified with different functional groups, including tert-butyltrimethylsilane and tert-butyl(methyl)diphenylsilane derivative: 1,3-bis(trifluoromethyl)benzene and alkylaniline cyanoacetate, respectively. Density functional theory calculations suggested this series of chromophores show much greater hyperpolarizability than traditional, nonlinear, optical chromophores due to strong electron donor ability. These chromophores, Z1–Z6, showed very high poling efficiencies due to the large steric hindrance and hyperpolarizability of the chromophores. A large poling efficiency (2.04 ± 0.08 nm2/V2) and r33 value (193 pm/V) were achieved for polymeric thin films doped with 25 wt% chromophore Z6 at 1310 nm

Characterizing the epidemiology, virology, and clinical features of influenza in China’s first severe acute respiratory infection sentinel surveillance system, February 2011 – October 2013

BACKGROUND: After the 2009 influenza A(H1N1)pdm09 pandemic, China established its first severe acute respiratory infections (SARI) sentinel surveillance system. METHODS: We analyzed data from SARI cases in 10 hospitals in 10 provinces in China from February 2011 to October 2013. RESULTS: Among 5,644 SARI cases, 330 (6%) were influenza-positive. Among these, 62% were influenza A and 38% were influenza B. Compared with influenza-negative cases, influenza-positive SARI cases had a higher median age (20.0 years vs.11.0, p=0.003) and were more likely to have at least one underlying chronic medical condition (age adjusted percent: 28% vs. 25%, p<0.001). The types/subtypes of dominant strains identified by SARI surveillance was almost always among dominant strains identified by the influenza like illness (ILI) surveillance system and influenza activity in both systems peaked at the same time. CONCLUSIONS: Data from China's first SARI sentinel surveillance system suggest that types/subtypes of circulating influenza strains and epidemic trends among SARI cases were similar to those among ILI cases