strain FB24: chrJ, chrK, and chrL. Future work should focus on elucidating the exact physiological function of these genes. However, our research is an important first step in Ro 61-8048 nmr characterizing potential regulatory networks controlling efflux-mediated chromate resistance. We further illustrate the value of examining the genomic context of already characterized metal resistance genes in identifying check details new players in metal resistance

mechanisms. Methods Bacterial strains and growth conditions Bacterial strains and plasmids used in this study are listed in Table 3. Arthrobacter strains were cultured in 0.1X or 0.2X nutrient broth (NB) [Difco, Sparks, MD], Luria-Bertani (LB) medium pH 7.0, or modified Xenobiotic Basal Medium (mXBM). Modified XBM contained 10 mM glycerol phosphate, 10 mM KNO3, 6.0 mM NH4NO3, 0.01 mM CaCl2, 2 ml L-1 of EDTA Fe Citrate Solution [7.4 mM FeCl3, 11.4 mM Na2EDTA, 12.8 mM sodium citrate (C6H5O7Na3), 100 mM MgSO4, 5% NH4Cl2, 0.05 M CaCl2, 1.0 M NaCl, 1 M NaHCO3], 10 ml L-1 of vitamin solution (see Jerke [48] and Additional file 4 for components), 1 ml L-1 SL-7 trace elements [49], with

glucose (1.7 mM) as a carbon and energy source. Table 3 Bacterial strains and plasmids used in this study. Strain or plasmid Description Reference Arthrobacter        FB24 CrR [6] selleck    D11 CrS derivative of FB24 This work E. coli   Org 27569      JM110 dam – dcm – Stratagene Plasmids

    pAOWA10128 7.3 kb insert in pMCL200 obtained from DOE-JGI. Contains Arth_4248-Arth_4254. DOE-JGI pBluescript II SK+ 3.0 kb, ApR, lacZ, used for sublconing inserts prior to ligation into pART2. Promega pART2 4.6 kb, KmR, pCG100 ori, ColE1 ori, vector for expression in Arthrobacter [55] pKH11 10.6 kb PCR product from FB24 plasmid 3 (CP000457) containing Arth_4247-4255 in pBluescript II SK+ This worka pKH12 Insert from pKH11 cloned into pART2 This work pKH21 7.3 kb insert from pAOWA10128 in pBluescript II SK+ This work pKH22 Insert from pKH21 cloned into pART2 This work pKH32 3.7 kb EcoRI-KpnI fragment from pKH21 cloned into pART2. Contains Arth_4248-4249. This work pKH42 3.8 kb XhoI-BglII fragment from pKH21 cloned into pART2. Contains Arth_4251-Arth_4254. This work pKH52 8.3 kb insert from MluI-BglII digest of pKH11 to delete Arth_4252 and Arth_4252 cloned into pART2 This work pKH62 pKH22 digested with SfiI to delete Arth_4249-Arth_4252. This work pKH72 pKH12 digested with ScaI and XbaI to delete Arth_4247. This work aA schematic of each construct is presented in Figure 3. Induction of Cr(VI) resistance genes was assessed in Arthrobacter sp. strain FB24 cells by culturing in 150 ml NB to early mid-log phase (OD600, 0.3) at 30°C with shaking at 200 rpm. Cells were harvested by centrifugation, washed once with 0.2X NB and suspended in 15 ml 0.2X NB.

Similarity searches using BLASTX revealed that eleven of the 16 regions contained sequences associated with phage proteins found in H. influenzae and related species. The remaining five regions encoded a putative tRNA-dihydrouridine synthase C, a predicted transcriptional regulator (NikR), a transport protein, and Hia and Hap proteins. Table 2 Regions in the H. influenzae strain RM7060 genome not found in strain 10810 Accession number Highest match by BLASTX analysis Species ZP_01791522 NikR predicted transcriptional regulator H. influenzae PittAA AAL79955 Hia/YadA-like similar to neisserial GNA992 H. influenzae nontypeable strain

1860A AAM74927 Hap peptidase S6 H. influenzae HK274 ZP_05977792 putative carboxylate/amino acid/amine transporter Neisseria mucosa P46495 Putative

PI3K Inhibitor Library integrase/recombinase HI_1572 H. influenzae ZP_00134779 Phage-related Mocetinostat ic50 protein, tail component Selleckchem PXD101 Actinobacillus pleuropneumoniae YP_001968298 Phage-related protein, tail component Actinobacillus pleuropneumoniae ZP_01791539 Mu-like prophage protein H. influenzae PittAA YP_003007008 Phage-related minor tail protein Aggregatibacter aphrophilus NJ8700 ZP_01791533 putative phage tail component H. influenzae PittAA YP_001290203.1 tRNA-dihydrouridine synthase C H. influenzae PittEE YP_001053216.1 predicted bacteriophage tail assembly protein Actinobacillus pleuropneumoniae L20 ZP_05990265 hypothetical protein COK_2151 Mannheimia haemolytica ZP_04753126 possible prophage antirepressor Actinobacillus minor NM305 ZP_04464399 Phage Mu protein F like protein H. influenzae 6P18H1 YP_003007004 phage protein Aggregatibacter

aphrophilus Experimental assessment of H. influenzae transformation High throughput sequencing provides a useful experimental tool to examine in detail the recombination events associated with the transfer and exchange of DNA between H. influenzae strains through transformation. To this end, we investigated the transformation of DNA from a Hib strain donor into a high efficiency recipient Vildagliptin strain. To ensure that each transformant was the result of a recombination event we used a spontaneous, high level streptomycin resistant (strR) derivative of strain Eagan (EaganstrR), possessing a point mutation in rpoB. Spontaneous strR mutants were infrequent (<10-10 in control transformations of Rd using streptomycin-sensitive Eagan DNA). Compared to strain Rd, the donor strain Eagan genome sequence had 18,789 SNPs relatively uniformly distributed throughout the genome (an average density of 10.3 SNPs per kbp) including the region around rpoB, the location of the strR mutation. Following transformation and selection on streptomycin, 200 independent Rd+EaganstrR colonies were pooled, the genomic DNA sequenced and mapped to the Rd reference genome sequence using the MAQ programme to identify SNPs.

The cells were washed 5 times with 1 ml PBS then fixed for 30 minutes at 4°C with 250 μl 2% paraformaldehyde (w/v). The coverslips were removed from the wells, washed with PBS then mounted onto glass slides with Vectashield-DAPI mounting medium (Vector Laboratories). The slides were examined using an Axiovert 200 M confocal MM-102 order microscope (Zeiss). At least three areas of approximately 10 cells each were examined per sample and the experiment was performed on three independent

occasions. Construction of ifp and inv insertional mutants An ifp knockout mutant was generated in the Y. pseudotuberculosis strain IP32953, after initially constructing an ifp mutant in strain YPIII. Briefly, 1725 bp of ifp was amplified with IntA and IntB primers, digested with SacI and SphI then ligated into the cloning vector pGEM-T easy. The find more plasmid was digested with BglII to linearise and allow for the ligation of the kanamycin cassette within the ifp sequence. PCR with primers

IntA and IntB was undertaken on the plasmid to create linear fragments of kanamycin cassette flanked by ifp sequence. This PCR product was electroporated into YPIII previously transformed with pKOBEG, which contains the λ red recombinase operon. The temperature sensitive pKOBEG plasmid was then lost from putative mutants by growth at 37°C, whilst the presence of EX 527 the pYV plasmid was maintained by the addition of 2.5 mM CaCl2. Southern blot analysis confirmed correct mutation. Genomic DNA from this YPIIIΔifp was used as a template for PCR Non-specific serine/threonine protein kinase amplification of the kanamycin cassette flanked by two ~500 bp regions of gene-specific DNA. The primers INTA and INTB (Table 2) were used to amplify a 2.7 kbp product. This was purified using a Qiagen PCR purification kit, precipitated, and then resuspended in 5 μl MilliQ H2O. Strain IP32953 containing the mutagenesis plasmid pAJD434 [33] was grown in LB broth containing 100 μg trimethoprim ml-1 and 0.8% arabinose

(w/v) for 5 hours at 28°C in order to induce the expression of the λ-red genes from the pAJD434 plasmid. These cells were electroporated with the purified PCR product and kanamycin resistant colonies were screened by PCR and Southern blot to confirm the correct insertion. The pAJD434 plasmid was then removed by incubation overnight at 37°C in the presence of 2.5 mM CaCl2. Colonies were screened to confirm the loss of the pAJD434 plasmid and the presence of the virulence plasmid (pYV). A similar method was used for the construction of the inv mutant except primers YPTB1668Chlor1 and YPTB1668Chlor4 (Table 2), were designed to amplify the chloramphenicol resistant cassette from pBAD33 flanked by 50 bp gene-specific regions. This PCR product was then used as described above to generate an insertional mutant of the inv gene (IPΔINV) and a double ifp and inv insertional mutant (IPΔIFPΔINV), by electroporation into IP32953 WT or mutated ifp (IPΔIFP) strains.

Sst2 tumor suppressor activity relies on see more an autocrine loop whereby its natural ligand somatostatin is secreted by sst2-expressing cells resulting in constitutive sst2 activation. However, molecular mechanisms responsible for sst2-dependent inhibition of invasiveness

are unknown. The a6b4 Selleckchem GDC-0994 integrin plays a critical role in epithelia integrity: its presence in hemidesmosal structures (HDs) at the basal cell surface links the intracellular intermediate filament network to the extracellular laminins of the basement membrane. Interestingly, HDs are frequently absent in cancer cells, whereas the a6b4 integrin (mostly its β4 subunit) is overexpressed in several cancers, including pancreatic, and contributes to carcinoma invasiveness by stimulating cell migration. This is partly achieved through a6b4 integrin delocalization into lamellipodia and filopodia. We have demonstrated that somatostatin, BX-795 datasheet by acting through sst2, can revert a6b4 integrin delocalization to migration structures, an hallmark of epithelial cancer cells, by forcing its relocalization to HDs, thereby stabilizing epithelial cell anchorage to basement membrane and inhibiting cell migration. Underlying molecular

mechanisms are here shown to rely on a sst2-dependent up-regulation of HDs protein expression, including BP180. Strikingly, knocking-down BP180 expression (siRNA) impairs somatostatin-induced HDs assembly in sst2-expressing cells. Interestingly, BP180 siRNA partially reverts sst2 inhibitory Gemcitabine chemical structure role on in vitro and in vivo cell migration and invasion, as demonstrated using the chick chorioallatoic membrane model whereby tumor progression of pancreatic

cancer cell xenografts is monitored. We have identified an original mechanism for sst2 to revert cancer cell pro-migratory phenotype by relocalizing the a6b4 integrin to HDs thereby facilitating hemidesmosome assembly and cancer cell anchorage to basement membrane. O85 Anti-JAM-C Tumor Growth Inhibition Occurs through Modulation of Thrombomodulin Expressing Stromal Cells Vincent Frontera 1 , Marie-Laure Arcangeli1, Claudia Zimmerli2, Florence Bardin1, Elodie Obrados1, Stephane Audebert1, Beat Imhof2, Jean Paul Borg1, Michel Aurrand-Lions1 1 Université de la méditerrannée institut poali calmettes, Inserm U891, Marseille, France, 2 Department of Pathology and Immunology, Centre Médical Universitaire, Geneva, Switzerland The Junctional Adhesion Molecule-C (JAM-C) has been identified as an adhesion molecule highly expressed by lymphatic sinuses of lymph nodes, mesenchymal and endothelial cells 1.

All patient Cyclosporin A materials were obtained with approval of local medical ethic committee. Patients were operated between 1990 and 2001, at the time of censoring 41 (59%) had died of whom 22 (54%) died from their disease, and 29 patients were still alive; four of them were alive with recurrence of the tumor. Mean follow up was 99 months (range 50–172 months). Patients with stage I/II (n = 47) and stage III (n = 23) colorectal cancer (as defined by the American Joint committee on Cancer and Union Internationale Contre le Cancer-criteria) were selected for this study. RT-PCR of CXCR4 in a Patient Cohort PCR primers for the detection of CXCR4 and the house-keeping genes (heterogeneous nuclear ribonucleoprotein M (HNRPM)

and TATA box binding protein (TBP) were designed in PRIMER Express (Applied Biosystems, USA) and span at least one exon-exon boundary. The primers used were: HNRPM, 5’-GAGGCCATGCTCCTGGG-3’, 5’-TTTAGCATCTTCCATGTGAAATCG-3’, TBP, 5’-CACGAACCACGGCACTGAT-3’, 5’-TTTTCTTGCTGCCAGTCTGGAC-3’ and CXCR4 5’-TTCTACCCCAATGACTTGTG-3’-5’-ATGTAGTAAGGCAGCCAACA-3’. RT-PCR reactions were performed on an ABI Prism 7900ht (Applied

Biosystems) using the SybrGreen RT-PCR core-kit (Eurogentec, Belgium). Cycle conditions were 10 min at 95°C followed by 40 cycles of 10 s at 95°C and 1 min at 60°C. Cycle threshold extraction was CP-868596 price performed using the SDS software (version 2.2.2, Applied Biosystems). For all PCR reactions, a standard curve was generated using a five-step, five-fold dilution of pooled cDNA from the HCT81 colorectal cancer cell line. Relative concentrations of mRNA for each gene were calculated from the standard curve. After RT-PCR, dissociation curves were made to check the quality of the reaction. Reactions

with more than one peak in the dissociation curve were discarded. For normalization, the expression values for each gene were divided by the normalization factor of the gene (the average of the two house keeping genes). Immunohistochemistry of CXCR4 in a Patient Cohort Megestrol Acetate A tissue find more microarray (TMA) was constructed from formalin-fixed, paraffin-embedded tissues from 58 curatively operated colorectal cancer patients as described previously [24]. Standard three-step, indirect immunohistochemistry was performed on 4-μm tissue sections transferred to glass slides using a tape-transfer system (Instrumedics, USA), including citrate antigen retrieval and blockage of endogenous peroxidase. Sections were overnight incubated with the primary antibody CXCR4 (Mouse-anti-Human CXCR4 IgG2B, clone MAB172, R&D Systems, USA). Secondary reagent used was biotinylated rabbit anti-mouse IgG antibodies (DAKO Cytomation, Denmark) and biotinylated-peroxidase streptavidin complex (SABC; DAKO Cytomation, Denmark). Microscopic analysis was assessed by two independent observers (F.M.S. and C.J.K.) in a double-blinded manner. Three different punches per patient were scored.

Several researchers have investigated the effect of these various forms of Cr in terms of Cr retention, uptake into

the muscle cell, and effects on performance [11–15], confirming CrM as the most effective formulation [10]. (For review of alternative forms see [10]) Previous research has also shown that the addition of certain nutrients to Cr may improve Cr retention [16–19]. For example, researchers have found that the co-ingestion of 5 g of CrM with 93 g of glucose significantly increased Cr retention by 60% compared to CrM alone after 5 days of 20 g · d-1[17]. Similarly the addition of certain macronutrients have also been shown to improve Cr retention [18]. STA-9090 mw Steenge et al. [18] found that the addition of 96 g of carbohydrates and/or 47 g of carbohydrates with 50 g of protein Entinostat chemical structure to 20 g of CrM daily improved Cr retention

by roughly 25% (p < 0.05) compared to 5 g carbohydrates. Results of the study suggest that higher insulin levels, in response to the additional macronutrients, may augment Cr uptake into the muscle. While co-ingesting large amounts of carbohydrate and/or protein with Cr has been reported to augment muscle and/or whole body Cr retention, some athletes or recreationally active individuals may be interested in lower-calorie strategies to improve Cr uptake. Recently there has been an interest in the effects of combining Cr with additional ingredients to else improve Cr uptake and retention. For example, Greenwood and associates [16] found that the co-ingestion GF120918 clinical trial of 1 g of D-pinitol (a plant extract with insulin-like properties) per day with CrM (20 g/d) for 3 days significantly improved Cr absorption and retention compared to CrM alone and a placebo. Ethanolic or aqueous extracts

of Russian Tarragon (RT) (artemisia dracunculus) have been purported to have anti-hyperglycemic effects. Theoretically, co-ingestion of RT with Cr may help augment Cr uptake [20, 21]. To support this theory, Jäger et al. [20] found that plasma Cr levels were reduced when RT was combined with CrM compared to CrM alone, suggesting an increase in Cr uptake. Therefore, the purpose of this study was to examine whether a low dose aqueous RT extract ingested 30 minutes prior to CrM intake during a 5-day loading phase significantly affected whole body Cr retention and/or anaerobic capacity in healthy, recreationally active males when compared to CrM ingestion alone. Methods Experimental design The study was conducted in a double-blind, randomized, and crossover manner. The independent variable was RT extract supplementation. Dependent variables included intramuscular Cr concentration, whole body Cr retention, and anaerobic sprint performance capacity. Participants who qualified for the study participated in a familiarization session in which the study was explained following written consent.

This technique combines the simplicity of microscopic observation and the specificity of DNA/rRNA hybridization, allowing detection of selected bacterial species and morphologic visualization [14, 15]. Nowadays, Peptide Nucleic Acid (PNA) probes are used instead of natural nucleic acids to improve FISH efficiency [16–19], because they enable more rapid and more specific hybridization [19–23]. The main goal of our work was to evaluate the PNA-FISH performance on mixed samples using a multiplex approach to detect Lactobacillus spp. and G. vaginalis. To validate the PNA probes, we determined,

both in silico and in vitro, their specificity and sensitivity, using a broad diversity of representative Lactobacillus and Gardnerella strains, as well as other taxonomically related or Metabolism inhibitor pathogenic bacterial MM-102 supplier strains commonly found in vaginal samples. To confirm the usefulness of our methodology, the efficiency and specificity of the probes was also tested at different concentrations of Lactobacillus and G. vaginalis strains in the presence of a monolayer of HeLa cells. Methods Culture of bacterial strains The bacterial strains used in this study are listed

in Table 1. All strains from Lactobacillus spp. were grown in Man, Rogosa and Sharpe agar (MRS; Sigma, Portugal), excepting L. iners that was grown in Brucella Blood agar (BBA; Oxoid, United Kingdom) as well as Atopobium vaginae and Gardnerella vaginalis. The remaining bacterial species were cultured on Brain Heart Infusion agar (BHI; Oxoid, United Kingdom) or Trypticase selleck products Soy Agar (TSA; Oxoid, United Kingdom). Each bacterial culture was streaked onto fresh plates every 48–72 h. Plates were incubated at 37°C or 30°C (in the case of L. pentosus strains) under anaerobic conditions (AnaeroGen Atmosphere Generation system; Oxoid, United Kingdom) for 24–48 h prior ALOX15 to FISH experiments. Table 1 Bacterial strains used in PNA-FISH assays and their specificity with Lac663 and Gard162 probes Bacterial

species Collection strain Lac663 Probe efficiency Gard162 Probe efficiency Lactobacillus acidophilus ATCC 4356T ++++ – L. crispatus ATCC 33820T ++++ – L. gasseri ATCC 9857T ++++ – L. reuteri NCFB 2656T +++ – L. rhamnosus ATCC 7469T ++++ – L. rhamnosus CECT 288T ++++ – L. johnsonii ATCC 11506T ++++ – L. hilgardii NCFB 962T +++ – L. delbrueckii subsp. delbrueckii ATCC 9649T +++ – L. delbrueckii subsp. lactis ATCC 12315T +++ – L. pentosus CECT 4023T ++++ – L. casei CECT 5275T ++++ – L. coryniformis subsp. torquens CECT 4129T ++++ – L. paracasei CECT 227T ++++ – L. agilis CCUG 31450T ++++ – L. animalis ATCC 35046T +++ – L. bifermentans ATCC 35409T +++ – L. brevis ATCC 14869T ++++ – L. buchneri ATCC 4005T +++ – L. fermentum ATCC 11739T +++ – L. curvatus subsp. curvatus ATCC 25601T ++++ – L. farciminis DSM 20182T ++++ – L. fructivorans ATCC 8288T +++ – L. gallinarum CCUG 31412T ++++ – L. graminis DSM 20719T ++ – L. hamsteri ATCC 43851T +++ – L.

Transferrin and its receptor (TfR1) play an important role during infection of macrophages with bacterial pathogens that prefer an intracellular lifestyle. Expression of TfR1 can in turn be modulated by bacterial infections [9]. Intracellular bacteria such as Mycobacterium tuberculosis and Ehrlichia [10, 11] actively recruit TfR1 to the bacterium-containing vacuole. However, the requirement

of TfR1 for bacterial pathogenesis has not been directly addressed. We sought here to determine if iron delivery through the transferrin receptor (TfR1) is essential for the success of two intracellular pathogens with CP673451 differing intracellular life-styles, Salmonella typhimurium and Francisella AZD5582 concentration tularensis. Salmonella typhimurium represents a well-characterized model intracellular find more pathogen, which causes typhoid fever in the mouse. Salmonella uncouples from the phagolysosomal pathway in macrophages and remains in a protected intracellular niche inside a vacuole [12]. The Salmonella-containing vacuole

(SCV) interacts with multiple endocytic pathways and avoids its fusion with acidic lysosomes. This is similar to infection with Chlamydia, Legionella, and Mycobacteriae. In contrast, Francisella tularensis, causative agent of tularemia and considered a category A biothreat because of its high infectivity and high case-fatality rate when untreated, enters the macrophage in a vesicle, but escapes from its enclosure into the cytosol after lysis of its vesicle within sixty minutes after entry into the host cell [13]. Both Francisella and Salmonella require iron for successful intracellular proliferation [14]. A Francisella operon, figABCD, has recently been described as being involved in iron acquisition [15, 14]. Recent studies from two groups using random transposon mutagenesis of either F. tularensis LVS [16] or F. novicida [17] showed that insertions into the figA, figB,

figC, or feoB genes caused reduced virulence of these mutants. While transposon insertions may cause polar effects on Tolmetin downstream genes, these data strongly suggest that expression of these particular gene products is essential for full virulence of Francisella species. In addition, expression of certain F.tularenis virulence genes is clearly regulated by iron availability [14, 18]. After exposure to just a few aerosolized Francisella, serum iron decreases very rapidly [19]. Bacteria counteract the host’s withholding of iron by secretion of iron chelators, which are termed siderophores, or by directly interacting with host iron-binding proteins [20–22]. The Francisella figABCDEF gene cluster (also referred to as fslABCDEF [23]) encodes such a siderophore, which belongs to the polycarboxylate family such as produced by Rhizopus species [15, 14].

Further, application of target analysis techniques utilizing specific kinetic models is required to extract the spectroscopic signature of the quenching

states and to identify the molecular mechanism of non-photochemical quenching. Acknowledgments J.T.M.K. and R.B. were supported by the Earth and Life Sciences council of the Netherlands Foundation for Scientific Research (NWO-ALW) through a VIDI and a Rubicon grant, respectively. The authors thank Cosimo Bonetti for providing Fig. 2. This manuscript was edited by Govindjee. Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. References Ahn TK, Avenson TJ, Ballottari M, Cheng YC, Niyogi P005091 cost KK, Bassi R, Fleming GR (2008) Architecture of a charge-transfer state regulating light harvesting in a plant antenna protein. Science 320:794–797PubMedCrossRef Arlt T, Schmidt S, Kaiser W, Lauterwasser C, Meyer M, Scheer H, Zinth W (1993) The accessory bacteriochlorophyll—a real electron carrier in primary photosynthesis. Proc Natl Acad Sci USA 90:11757–11761PubMedCrossRef Arnett DC, Moser CC, Dutton PL, Scherer NF (1999) The first events in photosynthesis: electronic coupling and energy transfer

dynamics in the photosynthetic reaction center from Rhodobacter CAL101 sphaeroides. J Phys Chem B 103:2014–2032CrossRef Berera R, see more Herrero C, Van Stokkum

IHM, Vengris M, Kodis G, Palacios RE, Van Amerongen H, Van Grondelle R, Gust D, Moore TA, Moore AL, Kennis JTM (2006) A simple artificial light-harvesting dyad as Niclosamide a model for excess energy dissipation in oxygenic photosynthesis. Proc Natl Acad Sci USA 103:5343–5348PubMedCrossRef Berera R, Van Stokkum IHM, Kodis G, Keirstead AE, Pillai S, Herrero C, Palacios RE, Vengris M, Van Grondelle R, Gust D, Moore TA, Moore AL, Kennis JTM (2007) Energy transfer, excited-state deactivation, and exciplex formation in artificial caroteno-phthalocyanine light-harvesting antennas. J Phys Chem B 111:6868–6877PubMedCrossRef Berera R, Van Stokkum IHM, D’Haene S, Kennis JTM, Van Grondelle R, Dekker JP (2009) A mechanism of energy dissipation in cyanobacteria. Biophys J 96:2261–2267PubMedCrossRef Billsten HH, Zigmantas D, Sundström V, Polivka T (2002) Dynamics of vibrational relaxation in the S1 state of carotenoids having 11 conjugated C=C bonds. Chem Phys Lett 355:465–470CrossRef Cerullo G, Polli D, Lanzani G, De Silvestri S, Hashimoto H, Cogdell RJ (2002) Photosynthetic light harvesting by carotenoids: detection of an intermediate excited state. Science 298:2395–2398PubMedCrossRef Chynwat V, Frank HA (1995) The application of the energy-gap law to the S1 energies and dynamics of carotenoids. Chem Phys 194:237–244CrossRef Cong H, Niedzwiedzki DM, Gibson GN, Frank HA (2008) Ultrafast time-resolved spectroscopy of xanthophylls at low temperature.

Acknowledgements The authors thank the

Program 973 (grant no.: 2013CB632102) and the National Natural Science Foundation of China (grant no.: 61176117). References 1. Han HS, Seo SY, Shin JH: Optical gain at 1.54 μm in erbium-doped silicon nanocluster sensitized waveguide. Appl Phys Lett 2001, 79:4568–4570.CrossRef 2. Miritello M, Savio RL, Iacona F, Franzò G, Irrera A, Piro AM, Bongiorno C, Priolo F: Efficient check details luminescence and energy transfer in erbium silicate Selleck Go6983 thin films. Adv Mater 2007, 19:1582–1588.CrossRef 3. Izeddin I, Moskalenko AS, Yassievich IN, Fujii M, Gregorkiewicz T: Nanosecond dynamics of the near-infrared photoluminescence of Er-doped SiO 2 sensitized with Si nanocrystals. Phys Rev Lett 2006, 97:207401.CrossRef 4. Anopchenko A, Tengattini selleck inhibitor A, Marconi A, Prtljaga N, Ramírez JM, Jambois O, Berencén Y, Navarro-Urrios D, Garrido B, Milesi F, Colonna JP, Fedeli JM: Bipolar pulsed excitation

of erbium-doped nanosilicon light emitting diodes. J Appl Phys 2012, 111:063102.CrossRef 5. Kik PG, Brongersma ML, Polman A: Strong exciton-erbium coupling in Si nanocrystal-doped SiO 2 . Appl Phys Lett 2000, 76:2325–2327.CrossRef 6. Fujii M, Yoshida M, Kanzawa Y, Hayashi S, Yamamoto K: 1.54 μm photoluminescence of Er 3+ doped into SiO 2 films containing Si nanocrystals: evidence for energy transfer from Si nanocrystals to Er 3+ . Appl Phys Lett 1997, 71:1198–1200.CrossRef 7. Irrera A, Iacona F, Franzò G, Miritello M, Savio RL, Castagna ME, Coffa S, Priolo F: Influence of the matrix properties on the performances of Er-doped Si nanoclusters

light emitting devices. J Appl Phys 2010, 107:054302.CrossRef 8. Franzò G, Pecora E, Priolo F, Iacona F: Role of the Si excess on the excitation of Er doped SiO x . Appl Phys Lett 2007, 90:183102.CrossRef 9. Franzò G, Boninelli S, Pacifici D, Priolo F, Iacona F, Bongiorno C: Sensitizing properties of amorphous Si clusters on the 1.54-μm luminescence of Er in Si-rich SiO2. Appl Phys Lett 2003, 82:3871–3873.CrossRef Adenosine triphosphate 10. Daldosso N, Luppi M, Ossicini S, Degoli E, Magri R, Dalba G, Fornasini P, Grisenti R, Rocca F, Pavesi L, Boninelli S, Priolo F, Spinella C, Iacona F: Role of the interface region on the optoelectronic properties of silicon nanocrystals embedded in SiO 2 . Phys Rev B 2003, 68:085327.CrossRef 11. Pavesi L, Negro LD, Mazzoleni C, Franzò G, Priolo F: Optical gain in silicon nanocrystals. Nature 2000, 408:440–444.CrossRef 12. Franzò G, Miritello M, Boninelli S, Savio RL, Grimaldi MG, Priolo F, Iacona F, Nicotra G, Spinella C, Coffa S: Microstructural evolution of SiOx films and its effect on the luminescence of Si nanoclusters. J Appl Phys 2008, 104:094306.CrossRef 13. Sun K, Xu WJ, Zhang B, You LP, Ran GZ, Qin GG: Strong enhancement of Er 3+ 1.54 μm electroluminescence through amorphous Si nanoparticles. Nanotech 2008, 19:105708.CrossRef 14. Wang YQ, Smirani R, Ross GG, Schiettekatte F: Ordered coalescence of Si nanocrystals in SiO 2 . Phys Rev B 2005, 71:161310(R). 15.