We introduce a new method for performing and miniaturizing many types of heterogeneous catalysis involving nanoparticles. The method makes use of the plasmon resonance present in nanoscale metal catalysts to provide the necessary heat of reaction when illuminated with a low-power laser. We demonstrate our approach by reforming a flowing, liquid mixture of ethanol and water over gold nanoparticle catalysts in a microfluidic channel. Plasmon heating of the nanoparticles provides not only the heat of reaction but the means to generate both water and ethanol vapor locally over the catalysts, which in turn allows the chip and the fluid lines to remain at room temperature. The measured products of the reaction, CO 2 , CO, and H 2 , are consistent with catalytic steam reforming of ethanol. The approach, which we refer to as plasmon-assisted catalysis, is general and can be used with a variety of endothermic catalytic processes involving nanoparticles.

SummarySalmonella genomic island 1 (SGI1) is a genomic island containing an antibiotic resistance gene cluster identified in several Salmonella enterica serovars. The SGI1 antibiotic resistance gene cluster, which is a complex class 1 integron, confers the common multidrug resistance phenotype of epidemic S. enterica Typhimurium DT104. The SGI1 occurrence in S. enterica serovars Typhimurium, Agona, Paratyphi B, Albany, Meleagridis and Newport indicates the horizontal transfer potential of SGI1. Here, we report that SGI1 could be conjugally transferred from S. enterica donor strains to non-SGI1 S. enterica and Escherichia coli recipient strains where it integrated into the recipient chromosome in a site-specific manner. First, an extrachromosomal circular form of SGI1 was identified by PCR which forms through a specific recombination of the left and right ends of the integrated SGI1. Chromosomal excision of SGI1 was found to require SGI1-encoded integrase which presents similarities to the lambdoid integrase family. Second, the conjugal transfer of SGI1 required the presence of a helper plasmid. The conjugative IncC plasmid R55 could thus mobilize in trans SGI1 which was transferred from the donor to the recipient strains. By this way, the conjugal transfer of SGI1 occurred at a frequency of 10----6 transconjugants per donor. No transconjugants could be obtained for the SGI1 donor lacking the int integrase gene. Third, chromosomal integration of SGI1 occurred via a site-specific recombination between a 18 bp sequence found in the circular form of SGI1 and a similar 18 bp sequence at the 3 ¢ ¢ ¢ ¢ end of thdF gene in the S. enterica and E. coli chromosome. SGI1 appeared to be transmissible only in the presence of additional conjugative functions provided in trans . SGI1 can thus be classified within the group of integrative mobilizable elements (IMEs).

The Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producing Enterobacteriaceae and Pseudomonas aeruginosa isolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively, and increased to 80% and 77.3%, respectively, using a more concentrated bacterial extract. False-negative results were associated with mucoid strains or linked to enzymes with low carbapenemase activity, particularly OXA-48-like, which has emerged globally in enterobacteria.

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The rates are remarkably similar to those found in our previous study; although we found wide variations in HA CDI among the participating hospitals. However, the attributable mortality increased almost 4-fold (5.7% vs. 1.5%; P<.001).

We introduce a new chemical vapor deposition (CVD) process that can be used to selectively deposit materials of many different types. The technique makes use of the plasmon resonance in nanoscale metal structures to produce the local heating necessary to initiate deposition when illuminated by a focused low-power laser. We demonstrate the technique, which we refer to as plasmon-assisted CVD (PACVD), by patterning the spatial deposition of PbO and TiO 2 on glass substrates coated with a dispersion of 23 nm gold particles. The morphology of both oxide deposits is consistent with local laser-induced heating of the gold particles by more than 150 °C. We show that temperature changes of this magnitude are consistent with our analysis of the heat-loss mechanisms. The technique is general and can be used to spatially control the deposition of virtually any material for which a CVD process exists.

Current methods of chemical vapour deposition (CVD) of graphene on copper are complicated by multiple processing steps and by high temperatures required in both preparing the copper and inducing subsequent film growth. Here we demonstrate a plasma-enhanced CVD chemistry that enables the entire process to take place in a single step, at reduced temperatures (o420°C), and in a matter of minutes. Growth on copper foils is found to nucleate from arrays of well-aligned domains, and the ensuing films possess sub-nanometre smoothness, excellent crystalline quality, low strain, few defects and roomtemperature electrical mobility up to (6.0 ± 1.0) Â 10 4 cm 2 V À 1 s À 1 , better than that of large, single-crystalline graphene derived from thermal CVD growth. These results indicate that elevated temperatures and crystalline substrates are not necessary for synthesizing high-quality graphene.

Human papillomavirus (HPV), particularly type 16 (HPV-16), is present in more than 99% of cervical cancers. The HPV oncoproteins E6 and E7 are constantly expressed and therefore represent ideal targets for HPV vaccine development. We previously developed DNA vaccines encoding calreticulin (CRT) linked to HPV-16 E7 and generated potent E7-specific CD8؉ T-cell immune responses and antitumor effects against an E7-expressing tumor. Since vaccines targeting E6 also represent an important strategy for controlling HPVassociated lesions, we developed a DNA vaccine encoding CRT linked to E6 (CRT/E6). Our results indicated that the CRT/E6 DNA vaccine, but not a wild-type E6 DNA vaccine, generated significant E6-specific CD8 ؉ T-cell immune responses in vaccinated mice. Mapping of the immunodominant epitope of E6 revealed that an E6 peptide comprising amino acids (aa) 48 to 57 (E6 aa48-57), presented by H-2K b , is the optimal peptide and that the region of E6 comprising aa 50 to 57 represents the minimal core sequence required for activating E6-specific CD8 ؉ T lymphocytes. We also demonstrated that E6 aa48-57 contains cytotoxic T-lymphocyte epitopes naturally presented by E6-expressing TC-1 cells. Vaccination with a CRT/E6 but not a CRT/mtE6 (lacking aa 50 to 57 of E6) DNA vaccine could protect vaccinated mice from challenge with E6-expressing TC-1 tumors. Thus, our data indicate that E6 aa48-57 contains the immunodominant epitope and that a CRT/E6 DNA vaccine may be useful for control of HPV infection and HPV-associated lesions.Cervical cancer is the second leading cause of cancer death among women worldwide, and more than 99% of cervical cancers contain human papillomavirus (HPV), particularly the high-risk HPV type 16 (HPV-16) (26). Two HPV oncoproteins, E6 and E7, are consistently expressed in HPV-associated cancer cells and are responsible for their malignant transformation. These oncogenic proteins therefore represent ideal target antigens for developing vaccines and immunotherapeutic strategies against HPV-associated neoplasms. Numerous preclinical studies and some clinical studies have targeted the HPV oncogenic proteins E6 and E7 for the development of vaccines to control HPV-associated lesions (for a review, see reference 16).DNA vaccines have become an appealing approach to generating antigen-specific immunotherapy because of their simplicity, stability, safety, and capacity for repeated administration (for reviews, see references 7, 17, 19, 22, and 24). Intradermal administration of DNA vaccines by means of a gene gun represents an efficient means of targeting dendritic cells, the most potent professional antigen-presenting cells, which are specialized to prime helper and killer T cells in vivo (5, 21). Using intradermally administered DNA vaccines, we have tested several intracellular targeting strategies to modify the properties of dendritic cells in order to enhance antigen presentation through the major histocompatibility complex (MHC) class I and class II pathways (for a review, see reference 11). Kim et...