(c) 2008 IBRO. Published by Elsevier Ltd. All rights reserved.”
“The murine cytomegalovirus (MCMV) M33 gene is conserved among all betaherpesviruses and encodes a homologue of seven-transmembrane receptors (7TMR) with the capacity for constitutive signaling. Previous studies have demonstrated that M33 is important for MCMV dissemination to or replication within the salivary glands. In this study, we probed N- and C-terminal regions of

M33 as well as known 7TMR signature motifs in transmembrane (TM) II and TM III to determine the impact on cell surface expression, constitutive signaling, and in vivo phenotype. The region between amino acids R-340 and A(353) of the C terminus was found to be important for CREB- and NFAT-mediated SB202190 in vitro signaling, Ro 61-8048 manufacturer although not essential for phosphatidylinositol turnover. Tagging or truncation of the N terminus of M33 resulted in loss of cell surface expression. Within TM II, an F79D mutation abolished constitutive signaling, demonstrating a role, as in other cellular and viral 7TMR, of TM II in receptor activation. In TM III, the arginine (but not the asparagine)

residue of the NRY motif (the counterpart of the common DRY motif in cellular 7TMR) was found to be essential for constitutive signaling. Selected mutations incorporated into recombinant MCMV showed that disruption of constitutive signaling for a viral 7TMR homologue resulted in a reduced capacity to disseminate to or replicate in the salivary glands. In addition, HCMV UL33 was found to partially compensate for the lack of M33 in vivo, suggesting conserved biological roles of the UL33 Exoribonuclease gene family.”
“Two P loop domain potassium (K2P or KCNK) channels

produce transmitter-modulated K(+) currents that could influence brain development. We mapped by in situ hybridization the expression of the K2P gene family in the developing mouse brain. All the K2P genes had different expression patterns, and it is likely that many neuronal types change their K2P channel subunit composition during development. Fitting with a possible role in the control of cell division, three K2P genes (r) under bar andem of P domains in a (w) under bar eak (i) under bar nwardly-rectifying (K) under bar (+) channel-(re) under bar lated (K) under bar (+) channel (TREK) -1, TREK-2 and (w) under bar eak (i) under bar nwardly-rectifying (K) under bar (+) channel-related (a) under bar cid-(s) under bar ensitive (K) under bar (+) channel (TASK) -2) had high expression in the embryonic subventricular and ventricular zones, and the (t) under bar andem of P domains in a (w) under bar eak (i) under bar nwardly-rectifying (K) under bar (+) channel (TWIK) -1, TREK-1, TREK-2 and TASK-3 genes were significantly expressed in the external cerebellar granule cell layer.

0% and 3.6%, respectively, for glucose and find more 14.2% and 8.3%, respectively, for insulin.

Conclusions: Variations in the range of 3.6% are observed in glucose measurements during the time course of an FDG scan even after

accounting for analytical error; larger variations of 8.3% are observed in insulin levels, Therefore, corrections of SUV for blood glucose, especially if obtained from single measurements, can introduce additional errors of at least this much. Published by Elsevier Inc.”
“In vitro studies have implicated activation of the p38 mitogen-activated protein kinase (MAPK) signalling pathway in cytokine-mediated pancreatic beta-cell injury. Activation of the p38 MAPK occurs through two different upstream kinases, mitogen-activated

protein selleckchem kinase kinase 3 (MKK3) and MKK6. This study examined the role of MKK3 signalling in an in vivo model of cytokine-dependent pancreatic injury induced by multiple low doses of streptozotocin (MLD-STZ). Groups of wild-type (WT) or Mkk3-/- C57BL/6J mice received 5 daily injections of STZ (40 mg/kg) and were killed on day 5, week 2 or week 4. MLD-STZ in WT mice exhibited two distinct phases of pancreatic damage: islet cell apoptosis (immunostaining for cleaved caspase-3) on day 5 in the absence of leukocyte infiltration, and this was followed by islet inflammation (leukocyte infiltration and cytokine production) and further islet cell apoptosis on day 14 resulting in a loss of insulin-producing beta-cells and an 80% incidence of hyperglycaemia. Mkk3-/- mice were not protected from the initial phase of STZ-induced islet cell apoptosis day 5. However, Mkk3-/- mice were completely protected from the induction of hyperglycaemia. This was attributed to inhibition of leukocyte infiltration, production of pro-inflammatory cytokines and islet cell apoptosis Etomidate at day 14 of MLD-STZ. In vitro studies showed that cultured islets from Mkk3-/- and WT mice are equally susceptible to STZ and cytokine-induced apoptosis. In conclusion, MKK3 signalling plays an essential role in the development of islet

inflammation leading to destruction of beta-cells and hyperglycaemia in MLD-STZ-induced pancreatic injury.”
“Introduction: A new F-18 ligand, 2-(2′-((dimethylamino)methyl)-4′-(3-[F-18]fluoropropoxy)-phenylthio)benzenamine ([F-18]1), for positron emission tomography (PET) imaging of serotonin transporters (SERT) was evaluated.

Methods: Binding affinity was determined through in vitro binding assays with LLC-PK1 cells overexpressing SERT, NET or DAT (LLC-SERT, LLC-NET and LLC-DAT) and with rat cortical homogenates. Localization and selectivity of [18F]1 binding in vivo were evaluated by biodistribution, autoradiography and A-PET imaging studies in rats.

Results: This compound displayed excellent binding affinity for SERT in vitro with K-i=0.33 and 0.24 nM in LLC-SERT and rat cortical homogenates, respectively. Biodistribution studies with [F-18]1 showed good brain uptake (1.

To our knowledge, our study is the largest patient survey of characteristics associated with osteoporosis diagnosis and treatment. However, the study had several limitations. First, because LXH254 the survey was based on self-report, there may have been recall bias concerning osteoporosis diagnosis and treatment. learn more Second, the survey population consisted of individuals who lived in or near western Pennsylvania, volunteered for a research registry, and

were disproportionately white, healthy, and highly educated, which may limit the generalizability of our results. However, it is possible that if even in this survey population individuals with several known risk factors for osteoporosis were not more likely to receive osteoporosis diagnosis or treatment, this may be an even larger problem in the general population of older adults. Third, our study had small numbers of individuals with certain osteoporosis risk factors, such as smokers and heavy alcohol drinkers, which may have limited our ability to detect an association between these characteristics and osteoporosis diagnosis or treatment. Our study also had several notable

strengths, including a large sample size, nearly 70% response AICAR rate, and inclusion of both female and male participants. In conclusion, we found that individuals with several key osteoporosis risk factors, such as advanced age, prolonged oral steroid use, and family history of osteoporosis, were either not more likely to receive osteoporosis diagnosis or not more likely to obtain treatment, when adjusting for other osteoporosis risk factors. Our results suggest that individuals with these risk factors are more likely to be underdiagnosed or undertreated. Future

investigations should confirm our findings in other study populations and investigate interventions to improve osteoporosis diagnosis and treatment rates in individuals at highest risk. Acknowledgements The authors thank Anna K. Ercius, MPH, for mailing surveys, data collection, and data entry; Deljo Gannon for data entry and validation; Linda Quinn and Terry Sefcik, MSIS, for assistance with survey design; the University of Pittsburgh Claude D. Pepper Older Americans Independence Center for access to a registry of Buspirone HCl individuals interested in research participation; and all of the individuals who responded to our survey. Funding This study was supported by grants KL2 RR024154-02 and UL1 RR024153 from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH) and NIH Roadmap for Medical Research (Dr. Nayak); grant K24 DK062895 from the National Institute of Diabetes and Digestive and Kidney Diseases (Dr. Greenspan); and grant P30 AG024827 from the National Institute on Aging (University of Pittsburgh Claude D.

5 and 399.5 eV are due to the amide N and other N of FA, respectively. The bands at 400.1 and 399.9 eV were in accordance with those of triazole ring N as reported [36]. However, the peak of free amide N at 398.5 eV disappeared in the spectrum of OCMCS-FA (Figure 6d), and a new peak at 400.8 eV

appeared due to the amide conjugation between FA and OCMCS. Interestingly, the N 1-s spectrum of Fe3O4@SiO2-OCMCS-FA https://www.selleckchem.com/products/ag-120-Ivosidenib.html nanovehicle (Figure 6c) showed similar peaks with OCMCS-FA except at 401.2 eV. The peak at 401.2 eV might be originated from the formation of amide linkage between the carboxyl group of the OCMCS and amide on the surface of silica which was reasonably consistent with the peak reported in the literature. Anyway, XPS results support OCMCS-FA chemically bound to the surface of Fe3O4@SiO2 by amidation. Figure

6 High-resolution C 1s, O 1s, and N 1s X-ray photoelectron spectra. (a) High-resolution C 1s spectrum of Fe3O4@SiO2-OCMCS-FA, (b) high-resolution O 1s spectrum of Fe3O4@SiO2-OCMCS-FA, (c) high-resolution N 1s spectrum of Fe3O4@SiO2-OCMCS-FA, (d) high-resolution N 1s of OCMCS-FA, and (e) high-resolution N 1s spectrum of FA. Moreover, the zeta potential of suspension for Fe3O4@SiO2-OCMCS-FA was -28.89 ± 0.43 mV which was smaller than that of Fe3O4 NPs considering that silica and OCMCS-FA modification protect the Fe3O4 NPs away from aggregation. As shown in Figure 7, spherical Fe3O4 NPs were chosen as the template to obtain multifunctional nanovehicle.

It can be seen that spherical Pexidartinib research buy Fe3O4 NPs were about 6 to 8 nm in size with high dispersibility (Figure 7a, inset). The corresponding high-resolution image (Figure 7a, inset) showed clear lattice fringes which corresponds to Fe3O4. A thick layer of dense silica was deposited onto the surface of Fe3O4 with a core thickness of 7 nm and shell thickness of 14 nm (Figure 7a) with uniform particle size and excellent morphology. Erlotinib cost Then, a thin layer of OCMCS-FA conjugated to the surface of Fe3O4@SiO2 through amidation with the aid of sodium tripolyphosphate (TPP) forms a tri-layered (5 nm) multifunctional nanovehicle (Fe3O4@SiO2-OCMCS-FA) (Figure 7b). The SEM image shows that the nanovehicles are very uniform in both size and shape (Figure 7b, inset). Figure 7 TEM images. (a) Fe3O4@SiO2 (inset: Fe3O4) and (b) Fe3O4@SiO2-OCMCS-FA (inset: SEM images of Fe3O4@SiO2-OCMCS-FA). The magnified hysteresis loop of Fe3O4@SiO2-OCMCS-FA nanovehicle which clearly showed that no remanence and hysteresis were detected demonstrated the superparamagnetism of the nanovehicle (Figure 8). After Tozasertib cost coating with silica, the magnetization of Fe3O4@SiO2 was undoubtedly decreased compared with the Fe3O4 nanoparticles for the shell and relatively low Fe3O4 amount. However, after the final modification of OCMCS-FA, the magnetization of the nanovesicles was not apparently decreased due to the thin outer layer.

A review of the literature. J Clin Periodontol 1995, 22(1):1–14.PubMedCrossRef 33. Bollen CM, Lambrechts P, Quirynen M: Comparison

of surface roughness of oral hard find more materials to the threshold surface roughness for bacterial plaque retention: a review of the literature. Dent Mater 1997, MS-275 in vivo 13(4):258–269.PubMedCrossRef 34. Lee BC, Jung GY, Kim DJ, Han JS: Initial bacterial adhesion on resin, titanium and zirconia in vitro. J Adv Prosthodont 2011, 3(2):81–4.PubMedCrossRefPubMedCentral 35. Öztürk O, Sudagidan M, Türkan U: Biofilm formation by Staphylococcus epidermidis on nitrogen ion implanted CoCrMo alloy material. J Biomed Mater Res 2007, 81A(3):663–668.CrossRef 36. Kajiyama S, Tsurumoto T, Osaki M, Yanagihara K, Shindo H: Quantitative analysis of Staphylococcus epidermidis biofilm on the surface of biomaterial. J Orthop Sci 2009, 14(6):769–775.PubMedCrossRef 37. Taylor

RL1, Verran J, Lees GC, Ward A: The influence of substratum topography on bacterial adhesion to polymethyl methacrylate. J Mater Sci Mater Med 1998, 9(1):17–22.PubMedCrossRef 38. Boks NP, Busscher HJ, van der Mei HC, Norde W: Bond-strengthening in staphylococcal adhesion to hydrophilic and hydrophobic surfaces using atomic force microscopy. Langmuir 2008, click here 24(22):12990–12994.PubMedCrossRef 39. Tang P, Zhang W, Wang Y, Zhang B, Wang H, Lin C, Zhang L: Effect of Superhydrophobic Surface of Titanium on Staphylococcus aureus Adhesion. J Nanomaterials 2011, 2011:8. doi:10.1155/2011/178921.CrossRef

40. Tegoulia VA, Cooper SL: Staphylococcus aureus adhesion to self-assembled monolayers: effect of surface chemistry and fibrinogen presence. Casein kinase 1 Colloids and Surfaces B: Biointerfaces 2002, 24(3):217–28.CrossRef 41. Al-Ahmad A, Wiedmann-Al-Ahmad M, Faust J, Bächle M, Follo M, Wolkewitz M, Hannig C, Hellwig E, Carvalho C, Kohal R: Biofilm formation and composition on different implant materials in vivo . J Biomed Mater Res B Appl Biomater 2010, 95(1):101–109.PubMedCrossRef 42. Scarano A, Piattelli M, Caputi S, Favero GA, Piattelli A: Bacterial adhesion on commercially pure titanium and zirconium oxide disks: an in vivo human study. J Periodontol 2004, 75(2):292–296.PubMedCrossRef 43. Poortinga AT, Bos R, Busscher HJ: Measurement of charge transfer during bacterial adhesion to an indium tin oxide surface in a parallel plate flow chamber. J Microbiol Methods 1999, 38(3):183–189.PubMedCrossRef Competing interests The authors declare that they have no competing interests. Authors’ contributions IY and HK have designed the study, IY, HK, TS, HS, and HH gathered the data, and IY, HK, MT, and MO analyzed the data. IY wrote the Initial drafts of the manuscript, and HK and MO performed the statistical analysis and ensure the accuracy of the data.

The diagnostic efficiency was constantly high at cutoff points of 0.2 kU/l (Hycor) up to 0.1 kU/l (Phadia) accompanied by an optimized sensitivity. Altogether, a cutoff point of at least 0.2 kU/l represented the most advantageous combination of specificity and sensitivity and yielded constantly high

diagnostic efficiency for both commercial test kits. Fig. 3 Sensitivity, specificity and diagnostic efficacy of the commercial cattle allergen tests (a Hycor, b Phadia) to identify the symptomatic claw trimmers, given in 27 claw trimmers with and 65 without work-related symptoms. We used different cut points between Tofacitinib chemical structure 0.35 and 0.10 kU/l (WS work-related symptoms) Discussion This paper is the first to report the results obtained with a self-prepared cattle allergen mix designed to represent the full spectrum of cattle allergens present in a typical agricultural workplace, PU-H71 order as previously characterized with immunoblotting (Heutelbeck et al. 2009). Additional tests with self-made cattle hair extracts can help to bridge the diagnostic gap seen in patients showing cattle-related symptoms, but negative results

in tests with commercially available extracts (Heutelbeck et al. 2007, 2009; Prahl et al. 1978; Ylönen et al. 1990). However, the complexity and the costs of the immunoblotting procedures involved in such tests are too high for routine use at present. For routine screening, the commercial test kits are more practicable and cost-effective. In our study, up to 27.8% of all claw trimmers with negative results using commercial test kits showed positive results with the self-prepared allergen mix extracted from cattle hair. Similar results have been previously reported (Heutelbeck et al. 2007; Prahl et al. 1978; Ylönen et al. 1990): some farmers with a negative result using commercially available serological allergy tests showed distinct reactions with cattle

allergens in immunoblotting experiments (Heutelbeck et al. 2009). Such inconsistencies between clinical symptoms and in vivo or in vitro diagnostics may result from the absence of certain ARN-509 mw important allergens in the commercial extract used for Amine dehydrogenase testing. The strong association of work-related allergy symptoms with cattle-related sensitization in this study may be a result of the unique characteristics of claw trimming with constantly high cattle allergen exposure. However, regarding the sensitization pattern in the immunoblot experiments, we found more specific reactivity at molecular weights of about 16 kDa rather than in the range of about 20 kDa previously described as the major allergen Bos d 2 (Prahl et al. 1982; Ylönen et al. 1992; Rautiainen et al. 1997). The relevance of these proteins to an earlier stage of sensitization should be addressed in further studies. To improve the sensitivity of commercial test kits, this study proposes an optimized cutoff level for two commercially available cattle allergen extracts. Cutoff levels around 0.

The apoptotic ratio was increased in NSBP1 knockdown 786-O cells compared to control (Figure 2B). To confirm that NSBP1 knockdown could inhibit proliferation and induce apoptosis in ccRCC cells, we examined the expression of apoptosis and cell cycle related proteins and found that Bax

protein level was significantly increased while CyclinB1 and Bcl-2 protein levels were decreased selleck chemical in NSBP1 knockdown cells compared with control (Figure 2C). These data provide evidence that NSBP1 modulates cell cycle and OSI-906 ic50 antagonizes apoptosis to promote the oncogenic potential of ccRCC cells. NSBP1 knockdown inhibits the invasion of ccRCC cells Next we assessed the role of NSBP1 in cell invasion, an important aspect of ccRCC metastasis. By transwell assay we found that NSBP1 knockdown cells showed few number of invading cells compared to control group which expressed high level of NSBP1 (Figure 3A). The number of cells crossing the matrigel was 62.3 ± 3.1 in NSBP1 siRNA group versus 110.7 ± 3.1 in scramble siRNA control group (P < 0.05). Moreover, gelatin zymography assay demonstrated that NSBP1 knockdown efficiently decreased MMP-2 and MMP-9 enzymatic activity, especially MMP-9 enzymatic activity (Figure 3B). To address whether decreased

MMP-9 and MMP-2 activity is due to the downreguation of their expression after NSBP1 knockdown, we examined the expression of MMP-9, MMP-2 and their upstream transcription factors c-fos and c-jun. Nirogacestat nmr Western blot analysis demonstrated that NSBP1 knockdown downregulated the expression of VEGF, VEGFR-2, MMP-2, MMP-9, c-fos and c-jun (Figure 3C). Taken together, these data suggest that NSBP1 upregulates the

expression of MMP-2 and MMP-9 via c-fos and c-jun. The increased MMPs activity and angiogenesis then contributes to the migration and invasion of ccRCC cells. Figure 3 NSBP1 knockdown inhibits the invasion of ccRCC cells. (A), Representative photos showing the invasion of ccRCC cells into the lower chamber of transwell. ×200. (B), Gelatin zymography assay showing that MMP-9 and MMP-2 activities were decreased in NSBP1 knockdown 786-O cells. Data shown Etofibrate were mean ± SEM from three independent experiments. (C), Western blot analysis showing that the expression of VEGF, VEGFR-2, MMP-2, MMP-9, c-fos and c-jun were significantly decreased in NSBP1 knockdown 786-O cells. Data shown were mean ± SEM from three independent experiments. *p < 0.05, **p < 0.01, versus the scramble siRNA transfected control group. NSBP1 knockdown inhibits ccRCC growth in xenograft nude mice To further investigate the role of NSBP1 in ccRCC in vivo, we established xenograft ccRCC by subcutaneous injection of 1 × 106 NSBP1 knockdown 786-O cells or the corresponding scramble siRNA transfected control cells into the flanks of BALB/c nude mice (n = 10).

The endophytic bacteria found inside the stems would be better protected against the antimicrobial effect of the essential oil. To support this argument, the susceptibility of the bacterial isolates to the essential oil obtained from L. sidoides genotypes LSID006 and LSID104 was determined. The essential oil from the genotype LSID006 was chosen to represent the ones from LSID003 and LSID105 which are Bromosporine datasheet Similar in their

thymol and carvacrol contents. MIC determination showed that 85.7% and 74.6% of the strains tested presented a MIC ≥ 0.25 mg ml-1 of essential oil from genotypes LSID006 and LSID104, respectively, CB-839 manufacturer suggesting an intermediate sensitivity of the isolates to the presence of both essential oils. However, no difference in the susceptibility range could be observed between the stem-derived and leaf-derived strains. It is important to state that the number of leaf-derived strains tested was much lower than the number of stem-derived strains, thus compromising the interpretation of the results obtained. In total,

145 endophytic Metabolism inhibitor bacterial isolates were obtained mostly from the stems. Our results suggest that the most dominant group associated with the L. sidoides genotypes was the Gammaproteobacteria, which is consistent with other studies [33, 37, 38]. Isolates from the genera Bacillus and Paenibacillus (belonging to the Firmicutes) were mainly obtained from LSID105 leaves (Figure 4). Because

members of these genera are spore formers, they may have resisted exposure to the essential oil after maceration of the leaves. Although we do not know whether Selleck Ibrutinib the isolated strains have any plant growth promoting potential, other studies have already demonstrated the importance of the different genera found here as nitrogen fixers, phosphate solubilizers and/or auxin producers in other plants [39, 40]. As the cultivation-dependent methodology used was affected by cell death in the leaves, the PCR-DGGE approach chosen to determine the structure of the microbial communities found in the leaves and stems of L. sidoides became crucial to this study. Moreover, it allowed access to the communities (such as the Alphaproteobacteria, Betaproteobacteria and Actinobacteria) possibly present in lower numbers or that failed to grow under the conditions used for isolation. Similar results were obtained when the total bacteria (accessed by two different sets of primers for PCR amplification), Alphaproteobacteria and Betaproteobacteria communities were considered. Slight differences in DGGE profiles were observed among the genotypes; nevertheless, these differences did not contribute to the grouping of the different communities as much as the location in the plant (stem or leaf) where these communities were found.

5 % and a one-sided type I error of 2.5 %. The primary efficacy variable was the percent change from baseline in lumbar spine BMD at week 52-Endpoint; the last valid post-baseline measurement was used when the week 52 value was missing (LOCF). Predefined secondary outcomes included changes in BMD at the lumbar spine and regions of the proximal femur, changes in biochemical markers of bone turnover, and incidence of morphometric vertebral fractures at week 104. No changes in secondary outcomes were made during the course of the study. Efficacy analyses were performed in the intent-to-treat (ITT) population consisting of all subjects who were randomized, received at least one dose of study drug, and had analyzable

BMD or bone marker data at baseline and at least one posttreatment time point. Ninety-five percent, two-sided confidence intervals (CIs) for the treatment difference were constructed and used to see more determine differences between IR daily and each of the DR weekly treatment groups. Nonparametric selleck methods were used to perform the statistical analysis of all bone biopsy parameters. The nonparametric Wilcoxon rank sum test was used for between-group comparisons. The nonparametric Hodges–Lehmann CIs (95 %) were constructed for the median differences between groups. Results Subjects A total of 1,859 women were screened; of these, 923 subjects were

randomized, and 922 subjects received at least one dose of study drug (Fig. 1). Baseline characteristics were previously described and were similar across treatment groups [1]. The median daily dose of calcium was 1,000 mg for all three treatment groups, and the median daily dose of vitamin D was 800 IU for all three treatment groups. A similar percentage of subjects in each treatment group completed the 104-week study (IR daily group, 80.8 %; DR FB weekly group, 76.2 %; DR BB weekly group, 77.9 %). The most common reasons given for withdrawal, which AR-13324 manufacturer occurred at similar incidences across all three treatment groups, were adverse event and voluntary withdrawal. A high percentage of ITT subjects in all groups (96.7 % of

subjects in the IR daily group, 96.7 % 3-oxoacyl-(acyl-carrier-protein) reductase of subjects in the DR FB weekly group, and 95.1 % of subjects in the DR BB weekly group) took at least 80 % of the study tablets. Fig. 1 Disposition of subjects Efficacy assessments As reported previously, all three treatment groups experienced significant improvements from baseline in lumbar spine BMD after 1 year of treatment. The response to both the 35-mg DR groups at week 52 was shown to be non-inferior and not superior to that observed with the 5-mg IR tablet. All three treatment groups continued to show significant improvements from baseline in lumbar spine BMD during the second year of the study with both 35-mg DR groups showing significantly greater increases than the 5-mg IR group (Fig. 2). The least squares mean percent change from baseline in lumbar spine BMD at week 104 was 5.5 % (95 % CI, 5.0 to 6.

Authors’ contributions RGG carried out the sample preparation, participated on its analysis, performed all the analyses except AFM and FTIR analyses, and wrote the paper. NTH also wrote the paper and analyzed the samples. JC performed the FTIR analysis. QRZ

participated on the AFM analysis and proof corrections. ZY, YJS, LYZ, and YFZ participated in the study guidance and paper correction. All authors read and approved the final manuscript.”
“Background Since the discovery of efficient visible photoluminescence (PL) of silicon nanoparticles (Si-np) due to quantum confinement effects (QCE) [1], the possibility selleck screening library of bandgap engineering of Si-based materials through the Si-np size control makes Si-based nanostructured material attracting for future applications in optoelectronics as low-cost, miniaturized, and CMOS-compatible, light-emitting devices (LEDs), laser, as well as photovoltaic devices. In the past, researches were focused on luminescent Si-np embedded in Si oxide media. However, the insulating nature of Si oxide remains a barrier for the production of future electrically pumped LEDs and efficient photovoltaic cells. This detrimental aspect can be overcomed to an extent, using a KU-57788 purchase higher conductive host medium like Si nitride which has a lower bandgap energy than SiO2. The first results on Si nitride are promising since many researchers

have reported on efficient visible PL with tunable light emission via the change of the Si nitride composition. However, it also turns out that selleck N-rich nitride [2–4] and Si-rich nitride thin Metalloexopeptidase films containing amorphous [5–8] or crystalline [9–14]

Si-np or without Si-np [15–18] can exhibit PL in the same spectral range. As a result, the mechanism of the PL in Si nitride is still a controversial subject in the literature. QCE in amorphous or crystalline Si-np, defect states in the bandgap, and band tail recombination have been proposed to account for the PL. However, since the synthesis methods were mostly based on chemical vapor deposition techniques, most of the films contained a significant amount of hydrogen [2, 5, 8, 10, 11, 13, 14, 16] and, in some cases, of oxygen [19, 20], which can both contribute to the PL. Consequently, it is difficult to experimentally distinguish the mechanisms of the PL. Then, this article is significant since we report on the structural and optical properties of Si-rich SiN x<1.33 thin films devoid of hydrogen and oxygen. The films were deposited by radio frequency (RF) magnetron sputtering. The excess of Si incorporated during the sputtering process makes possible the formation of Si-np during a suitable annealing. The microstructural properties of the films with regard to the composition and the annealing temperature are investigated. The possible contributions of the Si nitride medium and of Si-np formed during thermal annealing, or laser annealing, on the origin of the PL are discussed notably as a function of the Si-np phase (crystalline or amorphous).