Innovative and scalable security technologies are in high demand to deter increasing counterfeiting in modern society. Here, we report the first example of thermochromic–fluorescent ink based on semiconducting polymer dots (Pdots) by taking advantage of the unique optical properties of Pdots. We designed and synthesized two types of thermochromic molecules and then incorporated them with multicolor fluorescent Pdots. The resulting Pdots exhibited colorimetric and fluorescent dual-readout abilities in response to different temperatures which greatly increase the security level for anticounterfeiting applications. These multifunctional Pdots can be easily doped into flexible substrates or prepared as inks. These full-color inks can be further loaded into marker pens for handwriting or cartridges for inkjet printing with excellent signal-to-background contrast. Moreover, complex and delicate full-color images can be printed on security documents or currency for practical use. We anticipate that this first example of thermoresponsive dual-readout methodology based on Pdots will have broad use in advanced security marking technologies.

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Background/purpose The purpose of this study was to determine the pathogens and to estimate the incidence of pediatric community-acquired pneumonia (CAP) in Taiwan. Methods This prospective study was conducted at eight medical centers from November 2010 to September 2013. Children aged 6 weeks to 18 years who met the radiologic criteria for pneumonia were enrolled. To detect classical and atypical bacteria and viruses, blood and pleural fluids were cultured, and respiratory specimens were examined by multiple conventional and molecular methods. Results At least one potential pathogen was identified in 705 (68.3%) cases of 1032 children enrolled, including bacteria in 420 (40.7%) cases, virus in 180 (17.4%) cases, and mixed viral-bacterial infection in 105 (10.2%) cases. Streptococcus pneumoniae (31.6%) was the most common pathogen, followed by Mycoplasma pneumoniae (22.6%). Adenovirus (5.9%) was the most common virus. RSV was significantly associated with children aged under 2 years, S. pneumoniae in children aged between 2 and 5 years, and M. pneumoniae in children aged >5 years. The annual incidence rate of hospitalization for CAP was highest in children aged 2–5 years (229.7 per 100,000). From 2011 to 2012, significant reduction in hospitalization rates pertained in children under 5 years of age, in pneumonia caused by pneumococcus, adenovirus or co-infections and complicated pneumonia. Conclusion CAP related pathogens have changed after increased conjugated pneumococcal vaccination rates. This study described the latest incidences and trends of CAP pathogens, which are crucial for prompt delivery of appropriate therapy.

The theoretical prediction of H atom elimination on the excited state of phenol, imidazole and indole, the respective chromophores for the amino acids tyrosine, histidine and tryptophan, and the confirmation of theoretical prediction by experimental observations have a great impact on the explanation of photostability of amino acids upon irradiation with UV photons. On the other hand, no theoretical prediction of the excited state photodissociation dynamics has been made on the other aromatic amino acid, phenylalanine. In this work, photodissociation dynamics for various phenylalanine chromophores, including, phenylethylamine, N-methyl-phenylethylamine, and N-acetyl phenylalanine methyl ester was investigated in a molecular beam at 248 and 193 nm using multimass ion imaging techniques. The major dissociation channel for these compounds is the C-C bond cleavage. However, the photofragment translational energy distribution of phenylethylamine contains two components. The slow component corresponds to the dissociation on the ground state surface after internal conversion, and the fast component represents the dissociation from an excited state with a large exit barrier. The competition between the dissociation on the ground state and on the excited state changes as the size of chromophores increases. Internal conversion to the ground state prior to dissociation becomes the major nonradiative process for large chromophores. This study reveals the size-dependent photostability for these amino acid chromophores.