Individuals were also excluded from the non-hip fracture cohort if they had a hip fracture on or within 2 years after their assigned index date. Third, all eligible individuals in the hip fracture cohort were matched on index date (month and fiscal year), age (±3 months), sex, and residence status (community vs. long-term care (LTC))

to non-hip fracture patients. Fourth, a propensity score for hip fracture was calculated using logistic regression according to collapsed aggregated diagnostic group (comorbidity score) [12], rurality index for Ontario (population density and access to health-care services score) [13], and income quintile. Finally, hip fracture patients find more were matched 1:1 to non-hip fracture individuals on the logit of the propensity score using a greedy matching algorithm with a maximum caliper width of 0.2 and no replacement [14]. We therefore hard

matched on age, sex, and residence status at index; all factors for which we were interested in providing stratified results; and then propensity score matched on comorbidity and sociodemographics that may impact health-care resource utilization. SBE-��-CD nmr Health-care costing and outcomes We used an Ontario health-care payer perspective, where only direct costs paid by the Ontario Ministry of Health and Long-Term Care were considered. When possible, all costs were applied based on the year they were incurred and then inflated and reported in 2010 Canadian dollars using the health-care component of the Ontario consumer price index (CPI, www.​statscan.​gc.​ca). Detailed methods for case-costing using administrative

databases in Ontario have recently been published [15]. In brief, Vitamin B12 acute hospitalizations, emergency department, and same day surgery costs were calculated using the resource intensity weight method that uses the average provincial costs per weighted case based on distinct case mix groups [16, 17]. Costing in complex continuing care was based on distinct resource utilization groups, case mix index, and number of days in care [18]. Physician service costs and prescription drug costs were based on the total amount paid to the physician/pharmacy from the Ministry of Health. Costs related to length of stay in rehabilitation were based on the rehabilitation patient group case mix classification and weighting system for Ontario [19–21]. Costs for home care were determined by applying an average cost per service (or hour) [22]. LTC costs were calculated based on the average cost per day and length of stay. In addition to health-care costs, we assessed the number of individuals who died, entered LTC, and experienced a second hip fracture. Statistical analysis Cohort characteristics were summarized using means and proportions. Balance between matched cohorts was assessed using standardized difference, where values <0.1 indicate balance [23].

Cerebrovasc Dis 2008, 25:170–175.CrossRefPubMed 26. Yetkin G:Chlamydia pneumoniae and coronary artery disease: controversial results of serological studies. Int Immunopharmacol 2006, 6:1524–1525.CrossRefPubMed 27. Liuba P, Pesonen E: Infection and early atherosclerosis: does the evidence support causation? Acta Paediatr 2005, 94:643–651.CrossRefPubMed 28. Kalayoglu MV, Indrawati, Morrison RP, Morrison SG, Yuan Y, Byrne GI: Chlamydial virulence determinants

in atherogenesis: the role of chlamydial lipopolysaccharide and heat shock protein 60 in macrophage-lipoprotein interactions. J Infect Dis 2000,181(Suppl 3):S483–489.CrossRefPubMed Selleckchem S3I-201 29. Libby P, Ridker PM, Maseri A: Inflammation and atherosclerosis. Circulation 2002, 105:1135–1143.CrossRefPubMed 30. Khovidhunkit W, Kim MS, Memon RA, Shigenaga JK, Moser AH, Feingold KR, Grunfeld C: Effects of infection and inflammation on lipid and lipoprotein metabolism: mechanisms and consequences to the host. J Lipid Res 2004, 45:1169–1196.CrossRefPubMed 31. Bobkova D, Honsova E, Kovar J, Poledne R: Effect of diets on lipoprotein concentrations in heterozygous apolipoprotein E-deficient mice. Physiol Res 2004, 53:635–643.PubMed 32. Jawieñ J,

Nastałek P, Korbut R: Mouse models of experimental atherosclerosis. J Physiol Pharmacol 2004, 55:503–517.PubMed 33. Higuchi ML, Santos MH, Roggério A, Kawakami JT, Bezerra HG, Canzian M: A role for archaeal organisms in development of atherosclerotic vulnerable plaques and myxoid matrices. Clinics 2006, 61:473–478.CrossRefPubMed 34. NRC. National Research Council: Guide for the care and use of laboratory animals. National Academic JQ1 Press. Washington. DC 35. Kenny GE: Serodiagnosis. Mycoplasmas Molecular Biology and Pathogenesis (Edited by: McElhaney RN, Finch LR, Baseman JB). Washington:American Society for Microbiology 1991, 505–512. 36. Reynolds ES: The use of lead citrate at high pH as an electron-opaque stain in electron microscope. J Cel Biol 1963, 17:208–212.CrossRef 37. Davies G, Reid L: Growth of the alveoli and pulmonary

arteries in childhood. Thorax 1970, 25:669–681.CrossRefPubMed 38. Glagov S, Weisenberg E, Zarins CK, Stankunavicius R, Kolettis GJ: Compensatory enlargement of human atherosclerotic ROS1 coronary arteries. N Engl J Med 1987, 316:1371–1375.CrossRefPubMed 39. Nishioka T, Berglund H, Luo H, Nagai T, Siegel RJ: How should we define inadequate coronary arterial remodeling. Circulation 1998, 97:1424–1425.PubMed Authors’ contributions SBD and MLH – carried out the molecular genetic studies, participated in the sequence alignment and drafted the manuscript. MMR and MLH – participated in the design of the study and performed the statistical analysis. JTO; SAPP; RNI and LFPF – participated in the sequence alignment. MHL – conceived of the study, and participated in its design and coordination and helped to draft the manuscript. JT and FCP – carried out the immunoassays.

Orf56 codes for a 91.2-kDa protein of 808 amino acids that possesses a C-terminal peptidoglycan-degrading domain (amino acids 678-808). We assigned this domain to the cysteine, histidine-dependent amidohydrolase/peptidase (CHAP) family through bioinformatic analysis (additional file 3, Figure

S1) based on the reported characteristics of this domain [35]. Figure 1 Phage K genome. A section JQ1 of Phage K genome comprising the ORFs 29 to 67 is depicted. ORFs are indicated by colored arrows: putative lysis module (green), structural module (orange), proteins with a putative/hypothetical function (blue) and ORF56 (black). BLASTP [27] searches revealed that ORF56 is related to the tail lysin protein ORF005 of Staphylococcus phage G1 and ORF007 of Staphylococcus

phage Twort. A significant similarity was also found with GP98 of Listeria phage A511 (E value: 1e-120), GP29 of Listeria phage P100 (E value: 6e-120), putative tail lysin of Enterococcus phage PhiEF24C (E value: 3e-100), and putative tail lysin of Lactobacillus phage Lb338-1 (E value: 6e-53). Protein expression and activity of ORF56 and its N-terminal truncated forms CHAP domain-containing proteins have been reported to be lytic to staphylococci [36]. Incubating 100 μl crude preparation of ORF56 with 1 × 107 cells of MRSA clinical isolate B911 for 60 min reduced CFUs by 90% compared with the control, demonstrating www.selleckchem.com/products/srt2104-gsk2245840.html its bactericidal activity against S. aureus (additional file 4, Figure S2). To determine the function of ORF56, we cloned

and expressed the full-length (2427-bp) orf56 gene. This yielded a 91-kDa protein as well as lower molecular-weight proteins, all of which showed muralytic activity on zymograms. from This observation led us to generate truncated forms of ORF56 (57, 50, 23, 19, 16, and 13 kDa) (Figure 2a), all of which showed muralytic activity on zymograms and bactericidal activity against live Staphylococcus cells, except for the 13-kDa form, which was active only on zymograms (data not shown). The truncated 16-kDa ORF56, designated as Lys16 (Figure 2b), which showed cell wall-degrading activity on zymogram (Figure 2c) and lethal activity in S. aureus cultures (Figure 2d), was chosen for further characterization and development. Figure 2 ORF56 derivatives and purity profile, zymogram, and bactericidal activity of Lys16. (a) Schematic representation of ORF56 and its N-terminal truncated forms. (b) SDS-PAGE profile of Lys16. Lane 1: molecular weight marker (97.5-14 kDa), Lane 2: purified Lys16 (5 μg). (c) Zymogram of purified Lys16 (5 μg) on autoclaved S aureus RN4220 cells. The muralytic activity of Lys16 is seen as a clear zone. (d) Bactericidal activity of Lys16. Purified Lys16 (100 μg/ml) reduced MRSA B911 viable CFUs by three orders of magnitude (99.9% cells killed).

We would like to extend a special thanks to Angela George and Dale Preston of the Texas Animal Health Commission, Austin, Texas for assistance with sample preparation. We thank Dr. Abey Bandara and Dr. Tom Inzana at Virginia Tech for providing the Francisella tularensis LVS strain genomic DNA. We would like to extend a special thanks to

Greg Thorne and Shaukat Rangwala with MoGene their valuable technical assistance. XAV-939 ic50 We appreciate the assistance of Linda Gunn, Renee Nester, Traci Roberts and Laurie Spotswood for administrative assistance. We also appreciate Zyagen and BEI resources for providing genomic DNA. Electronic supplementary material Additional file 1: Table S1 Distribution of probe types included in the UBDA design. The table describes the different data set features on the array. (PDF 55 KB) Additional file 2: Table S2 Sequence of labelling control oligonucleotide probes. Sequence information of the 70-mer oligonucleotides used in the spike-in study to determine the sensitivity of the UBDA array. (PDF 7 KB) Additional file 3: Figures S1A – S1D. Regression

analysis of signal Kinase Inhibitor Library nmr intensity values generated from spike in of different concentrations of 70-mer oligonucleotides to human genomic DNA versus the un-spiked sample. Average Cy3 signal intensity values were plotted on a log scale. Normalized signal intensities from the Cy3 channel, which were human genomic DNA samples with and without the addition of 6 spike-in 70-mer oligonucleotides,

were compared by linear regression. Each notation on the graph represents an individual control probe spot on the array. The R2 value is displayed in the lower right quadrant of the graph. Purple × represent perfect match probes (PM), blue diamonds represent 1 mis-match (MM) probes, red squares represent probes with 2 mis-matches and green triangles represent Urease 3 mis-matches. (A) At 4.5 picomolar of oligonucleotide spike-in, an R2 value of 0.96 was obtained for probes with a PM, 0.93 for 1 MM, 0.95 for 2 MM and 0.92 for 3 MM. (B) At 41 picomolar of oligonucleotide spike-in, an R2 value of 0.96 was obtained for probes with a PM, 0.87 for 1 MM, 0.94 for 2 MM and 0.86 for 3 MM. (C) At 121 picomolar of oligonucleotide spike-in, an R2 value of 0.92 was obtained for probes with a PM (perfect match), 0.85 for 1 MM, 0.90 for 2 MM and 0.83 for 3 MM. (D) At 364 picomolar of oligonucleotide spike-in, an R2 value of 0.84 was obtained for probes with a PM (perfect match), 0.81 for 1 MM, 0.90 for 2 MM and 0.75 for 3 MM. Blast searches were done for all 70 mer probe combinations to the human genome sequence. The 2 MM 70-mer oligonucleotide probes were highly similar to the human genome and hence are not considered informative and do not show any variation as represented by the linear regression value. (PDF 172 KB) Additional file 4: Figure S2. Analysis of probe hybridization specificity on the UBDA array.

J Bacteriol 2009, 191:2764–2775.PubMedCrossRef 11. Bellanger X, Morel C, Decaris B, Guédon G: Derepression of excision of integrative and potentially conjugative elements from Streptococcus thermophilus by DNA damage response: implication of a cI-related repressor. J Bacteriol 2007, 189:1478–1481.PubMedCrossRef

12. Bose B, Auchtung JM, Lee CA, Grossman AD: A conserved anti-repressor controls horizontal gene transfer by proteolysis. Mol Microbiol 2008, 70:570–582.PubMedCrossRef 13. Dodd IB, Shearwin KE, Egan JB: Revisited gene regulation in bacteriophage lambda. Curr Opin Genet Dev 2005, 15:145–152.PubMedCrossRef 14. Beaber JW, Burrus V, Hochhut B, Waldor MK: Comparison of SXT and R391, two conjugative integrating elements: definition of a genetic backbone for the mobilization of resistance determinants. Cell Mol Life Sci 2002, 59:2065–2070.PubMedCrossRef 15. Beaber JW, Hochhut Cytoskeletal Signaling B, Waldor MK: SOS response promotes horizontal dissemination of antibiotic resistance genes. Nature 2004, 427:72–74.PubMedCrossRef 16. Bose B, Grossman AD: Regulation of horizontal gene transfer in Bacillus subtilis by activation of a conserved site-specific protease. J Bacteriol 2011, 193:22–29.PubMedCrossRef 17. Auchtung JM, Lee CA, Monson RE, Lehman AP, Grossman AD: Regulation of a

Bacillus subtilis mobile genetic element by intercellular signaling and the global DNA damage response. Proc Natl Acad Sci USA 2005, 102:12554–12559.PubMedCrossRef Hormones antagonist 18. Ramsay JP, Sullivan JT, Jambari N, Ortori CA, Heeb S, Williams P, Barrett DA, Lamont IL, Ronson CW: A LuxRI-family regulatory system controls excision and transfer of the Mesorhizobium loti strain R7A symbiosis island by activating expression of two conserved hypothetical genes. Mol Microbiol 2009, 73:1141–1155.PubMedCrossRef 19. RNAfold web server [http://​rna.​tbi.​univie.​ac.​at/​cgi-bin/​RNAfold.​cgi] 20. Solaiman

Dolutegravir DK, Somkuti GA: Isolation and characterization of transcription signal sequences from Streptococcus thermophilus . Curr Microbiol 1997, 34:216–219.PubMedCrossRef 21. Bellanger X, Morel C, Gonot F, Puymège A, Decaris B, Guédon G: Site-specific accretion of an Integrative Conjugative Element and a related genomic island leads to cis -mobilization and gene capture. Mol Microbiol 2011. Accepted 22. Croucher NJ, Harris SR, Fraser C, Quail MA, Burton J, van der Linden M, McGee L, von Gottberg A, Song JH, Ko KS, Pichon B, Baker S, Parry CM, Lambertsen LM, Shahinas D, Pillai DR, Mitchell TJ, Dougan G, Tomasz A, Klugman KP, Parkhill J, Hanage WP, Bentley SD: Rapid pneumococcal evolution in response to clinical interventions. Science 2011, 331:430–434.PubMedCrossRef 23. Sitkiewicz I, Green NM, Guo N, Mereghetti L, Musser JM: Lateral gene transfer of streptococcal ICE element RD2 (region of difference 2) encoding secreted proteins. BMC Microbiol 2011, 11:65.PubMedCrossRef 24.

The faster uptake of LPK++ NPs may be due to the

electrostatic attraction between the positive surface charges on LPK ++ and the negative charges on the plasma membrane of DCs. Figure 5 Flow cytometry measurement of uptake of PK NPs and LPK NPs by JAWSII DCs. One milligram of NPs was incubated with 106 cells for 1, 2, and 3 h, respectively. As time lapsed, more NPs were ingested by cells. Enhanced uptake of LPK NPs by DCs was observed compared to PK NPs. DCs are more readily to uptake positively charged NPs compared www.selleckchem.com/products/AZD7762.html to negatively charged NPs. Most of the cells (>90%) had taken up LPK NPs in 3 h, while only 52% of the cells had taken up PK NPs. Figure 6 Confocal images of internalization of PK NPs and LPK NPs by JAWSII DCs. One hundred thousand cells were incubated with 0.1 mg NPs for 1 h (A), 2 h (B), and 3 h (C), respectively. The incubation concentration was 0.2 mg/mL. Red color is from rhodamine B, which was used to label KLH; green color is from NBD PE, which is a fluorescent lipid used to label the lipid layer; and blue color is from CellMask™ Blue Stain, which was used to label the cell membrane. Both positively charged LPK NPs and negatively charged LPK NPs were internalized more readily by cells than PK NPs. Scale bars represent 5 μm. Conclusions In summary, lipid-PLGA hybrid NPs with variable lipid compositions were

constructed. As a potential antigen delivery system, lipid-PLGA Bioactive Compound Library cell assay NPs exhibited superior quality in comparison Glutamate dehydrogenase to PLGA NPs in terms of stability, antigen release, and particle uptake by DCs. The in vitro performance of lipid-PLGA NPs was highly influenced by the composition of the lipid layer, which dictates

the surface chemistry of hybrid NPs. Hybrid NPs enveloped by lipids with more positive surface charges demonstrated higher stability, better controlled release of antigen, and more efficient uptake by DCs than particles with less positive surface charges. The results should provide basis for future design of lipid-PLGA hybrid NPs intended for antigen delivery. Acknowledgements This work was financially supported by the National Institutes of Health, more specifically, the National Institute on Drug Abuse (R21 DA030083). References 1. Grottkau BE, Cai X, Wang J, Yang X, Lin Y: Polymeric nanoparticles for a drug delivery system. Curr Drug Metab 2013, 14:840–846. 10.2174/138920021131400105CrossRef 2. Mallick S, Choi JS: Liposomes: versatile and biocompatible nanovesicles for efficient biomolecules delivery. J Nanosci Nanotechnol 2014, 14:755–765. 10.1166/jnn.2014.9080CrossRef 3. Danhier F, Ansorena E, Silva JM, Coco R, Le Breton A, Preat V: PLGA-based nanoparticles: an overview of biomedical applications. J Control Release 2012, 161:505–522. 10.1016/j.jconrel.2012.01.043CrossRef 4.

Previous work confirmed the role of Hfq and Fur in SodB expression [39]. Deletion of fur results in increased transcription of the sRNAs (rfrA and rfrB) that can pair with mRNA of sodB in an Hfq-dependent fashion and result in the degradation of sodB mRNA. However, a combined deletion of

hfq in Δfur results in loss of rfrAB-mediated degradation of sodB, and results in the synthesis of SodB protein that gets activated to FeSOD in the presence of Fe2+. Our decision to further study ftnB and hmpA was due to our previous findings, where we found that ftnB and hmpA were activated and repressed by Fnr, respectively [21]. The Fnr-dependent expression of ftnB was apparent from the reduced activity in Δfnr under anaerobic conditions, Selleck CX5461 and the reduced activity in the WT strain in presence of oxygen. In addition, iron chelation and the deletion of fur reduced ftnB expression regardless of the oxygen tension. These results indicated that Fur controlled regulation of ftnB is independent of Fnr. Our results are in agreement with earlier work that demonstrated dependence of ftnB expression on Fur [15]. www.selleckchem.com/products/GSK872-GSK2399872A.html However, they are contrary to a previous report, which

determined that Fur exhibited a repressive role on ftnB expression [79]. The reason for this discrepancy is unclear. It is evident from work reported herein and in a previous study in E. coli that ftnB exhibits a strong dependence on low O2 conditions [108]. Furthermore, the earlier study [108] determined that Fnr bound the promoter

of ftnB in E. selleck inhibitor coli and that the Fnr binding site was further upstream than in known Fnr regulated genes. The same investigators [108], postulated that Fnr was unable to induce ftnB and that other regulators were required. However, we have determined that Fnr alone contributes to the activation of ftnB and that Fur is required for full induction of the gene, with Fnr exhibiting a more pronounced role. The lack of a predicted Fur binding site in ftnB indicated that Fur regulation was indirect. The following scenario is proposed to explain these findings and to suggest that the observed regulation of ftnB by Fur is mediated by the histone-like protein H-NS. First, the microarray data showed that Fur negatively regulates the expression of hns and has a predicted Fur binding site (Table 3). Second, we recently demonstrated that Fur binds upstream of hns in a metal dependent fashion [29]. Third, whole genome ChIP analysis demonstrated that H-NS binds to ftnB and the expression of ftnB is up-regulated in the absence of hns [31]. Fourth, the tdc operon is a known target for H-NS repression [31, 76] and was significantly reduced in the absence of fur. Therefore, we propose that the positive regulation ftnB by Fur is mediated by the negative regulation of hns by Fur. Thus removal of Fur (i.e., as in Δfur) results in repression of ftnB by H-NS (see Figure 7).

Phys Rev B 1996, 54:11169–11186.CrossRef 20. Perdew JP, Chevary JA, Vosko SH, Jackson KA, Pederson MR, Singh DJ, Fiolhais C: Atoms, molecules, solids, and surfaces: applications of the generalized gradient approximation for exchange and correlation. Phys Rev B 1992, 46:6671–6687.CrossRef 21. Vanderbilt D: Soft self-consistent pseudopotentials in a generalized

eigenvalue formalism. Phys Rev B 1990, PRI-724 clinical trial 41:7892–7895.CrossRef Competing interests The authors declare that they have no competing interests. Authors’ contributions CC carried out the computation and wrote the manuscript. JHZ, GFD, HZS, and BYN provided technical assistance in computation. XJN, LZ, and JZ conceived and supervised the computation and discussed the results. CC and JZ co-wrote the manuscript. mTOR inhibitor All authors read and approved the final manuscript.”
“Background The more stable phases in iron oxides are hematite and magnetite. Hematite can be used in a lot of applications, such as sensors [1], water photooxidation [2], drug delivery [3], lithium ion battery [4], pigmentation [5], solar cell [6], etc., and magnetite can be utilized in biomedicine [7–11], magnetic devices [12],

etc. Therefore, studies about the nano/microstructures of iron oxides and their properties, which are related to the intrinsic structure and crystal shapes, have been intensively engaged, especially for hematite and magnetite. The bandgap of hematite is 2.0 to 2.2 eV which makes it useful in applications that involve visible light absorption [13, 14]. Magnetite has unique electric and magnetic properties because its intrinsic crystal structure allows electrons to be transferred between Fe2+ and Fe3+ in

the octahedral sites [15]. Many researches have demonstrated the capability of using chemical syntheses to control particle morphologies of iron oxide by surfactants [16–18]. Morphologies like wires [19], rods [20], tubes [21], rings [22], disks [23], cubes [24], spheres [25], hexagonal plates of α-Fe2O3 [26, 27], and polyhedral particles of Fe3O4 [28, 29] have been synthesized successfully. Several robust methods have been MycoClean Mycoplasma Removal Kit developed for phase transformation of iron oxides. α-Fe2O3 can be transformed to Fe3O4 at high temperature under a reducing ambient, such as hydrogen ambient [30, 31]. Yanagisawa and Yamasaki also showed that by controlling the mineralizer solutions, temperatures, and partial pressures of hydrogen in a hydrothermal system, phase transformation from α-Fe2O3 to Fe3O4 particles can be achieved [32]. The result indicated that high temperature and high pressure of hydrogen can accelerate the reduction reaction. Phase transition of iron oxides can also take place by hydrothermal reaction with a reducing agent [33, 34].

33 μm, and the length varied from 0.13 to 0.93 μm (Figure 5B). The aspect ratio is defined as the length divided by the width. The average aspect ratio was 1.47, with values ranging between 1.0 and 2.8. The largest observed block had a width of 0.33 μm, a length of 0.93 μm, and a maximum aspect ratio of 2.8 (Figure 5D). Murphy and co-workers reported that surfactants such as cetyltrimethylammonium

bromide or small ions act as structure-directing agents in the formation of anisotropic nanostructures [20]. We hypothesize that the structure-directing agents in the extracts likely induced the formation of anisotropic shapes during synthesis. We previously reported the presence of glycosaminoglycans in these earthworm extracts [15]. Glycosaminoglycans are water-soluble compounds with large negative charges that can act this website as structure-directing agents. Based on the interpretation of the FT-IR spectra, proteins/peptides are the likely other candidates. Figure 5 FE-SEM images of the EW-AuNPs. The scale Selleckchem Luminespib bar represents (A) 10 μm, (B) 1 μm, (C) 1 μm, and (D) 100 nm. Conclusions We report the green synthesis of AuNPs using aqueous earthworm extracts

as reducing agents to convert Au3+ to AuNPs and the characterization of these AuNPs. The reactions occurred in water without the use of any other toxic chemicals; thus, the resulting AuNPs were available for subsequent biological tests. Anisotropic NPs were observed in addition to the spherical NPs. We are unable to explain how the anisotropic NPs were generated, and this topic will be explored in future work. From the FT-IR spectra, we could conclude that the proteins/peptides in the extract were involved in the reduction of Au3+ and in the stabilization of the EW-AuNPs. In addition, the anticoagulant activity of heparin was reinforced when combined with the EW-AuNPs, which suggests that AuNPs are involved in the Meloxicam blood coagulation cascade. The current study demonstrates that the newly prepared AuNPs are promising candidates for novel gold nanomedicines. Acknowledgements This work was supported by the National Research Foundation of

Korea (NRF) grant funded by the Korean government: the Ministry of Education (NRF-2012R1A1A2042224) and the Ministry of Science, ICT & Future Planning (NRF-2010-18282). References 1. Sperling RA, Rivera Gil P, Zhang F, Zanella M, Parak WJ: Biological applications of gold nanoparticles. Chem Soc Rev 2008, 37:1896–1908.CrossRef 2. Yeh YC, Creran B, Rotello VM: Gold nanoparticles: preparation, properties, and applications in bionanotechnology. Nanoscale 2012, 4:1871–1880.CrossRef 3. Dreaden EC, Alkilany AM, Huang X, Murphy CJ, El-Sayed MA: The golden age: gold nanoparticles for biomedicine. Chem Soc Rev 2012, 41:2740–2779.CrossRef 4. Park Y, Hong YN, Weyers A, Kim YS, Linhardt RJ: Polysaccharides and phytochemicals: a natural reservoir for the green synthesis of gold and silver nanoparticles. IET Nanobiotechnol 2011, 5:69–78.CrossRef 5.

The temperature of the furnace was maintained at 900°C during the oxidation process. To avoid cracks or warping, the wafers were placed inside the furnace at 600°C. The furnace was heated slowly with a ramp rate of +13°C/min. During the oxidation process, hydrogen and oxygen gases were used

with flow rates of 4 and 2.5 standard liters per minute (SLM), respectively. The oxidation time was 90 min. Then, W metal buy Compound Library as a bottom electrode (BE) with a thickness of approximately 200 nm was deposited by radio frequency (RF) sputtering on SiO2/Si wafers. The deposition parameters of the W layer were shown in Table  1. Then, the BE was defined and patterned by standard photolithography and wet chemical etching processes. The following parameters were used for the photolithography process. The wafer is initially heated at 120°C for 10 min in the oven

to drive off any moisture that may be present on the wafer surface. A liquid ‘adhesion promoter’ such as hexamethyldisilazane or HMDS was applied to promote adhesion of the photoresist to the wafer. A spin coater was used to coat the HMDS on the wafer. The spin coating was run at initially 3,000 rpm for 10 s and then 5,000 rpm for 20 s. Following the same process, an AZ6112 positive photoresist (AZ Electronic Materials, Branchburg, NJ, USA) was spun on the wafer to create the pattern. The photoresist-coated wafer was then prebaked to drive off excess photoresist Inhibitor Library chemical structure solvent at 90°C for 2 min. After prebaking, the sample was placed on a vacuum substrate of an optical lithography system (ABM Sales Service, San Jose, CA, USA). Then, mask 1 was placed over the sample. The photoresist was exposed to ultraviolet (UV) light for 4 s. Before developing, a postexposure bake (PEB) was performed at 90°C for 1 min to reduce the standing wave phenomena caused by the destructive and constructive interference patterns of the incident light. The wafer was immersed into the AZ330 developer (AZ Electronic Materials) for 15 s to remove the exposed photoresist and then rinsed by deionized

(DI) water. The resulting wafer was then ‘hard-baked’ to harden the final resist at 120°C for Oxalosuccinic acid 15 min. The wet chemical etching process was used to etch the uncovered W metal layer and form the W BE. A commercially available tungsten etchant (Sigma-Aldrich) was used, and the wafer was dipped into the solution for 2 to 3 min. The same photolithography process was repeated to design the 1 × 1 to 10 × 10 arrays. To pattern the switching material and TE, mask 2 was placed over the samples using a mask aligner. After the masking process, the GeO x switching material with a thickness of approximately 10 nm was deposited by the same RF sputtering system. Following this, Cu as a TE with a thickness of approximately 40 nm was deposited using a thermal evaporator. Then, the aluminum (Al) layer with a thickness of approximately 160 nm was deposited in situ by the thermal evaporator.