Proc Natl Acad Sci USA 2004,101(39):14240–14245.Selleckchem GDC 973 PubMedCrossRef 20. Arun S, Neubauer H, Gurel A, Ayyildiz G, Kuscu B, Yesildere T, Meyer H, Hermanns W: Equine glanders in Turkey. Vet Rec 1999,144(10):255–258.PubMedCrossRef 21. Neubauer H, Meyer H, Finke EJ: Human glanders. Revue Internationale des Services de Sante des Forces Armees 1997, 70:258–265. 22. Whitlock GC, Estes DM, Torres AG: Glanders: off to the races with Burkholderia mallei. FEMS Microbiol Lett 2007,277(2):115–122.PubMedCrossRef

23. Srinivasan A, Kraus CN, DeShazer D, Becker PM, Dick JD, Spacek L, Bartlett JG, Byrne WR, Thomas DL: Glanders in a military research microbiologist. N Engl J Med 2001,345(4):256–258.PubMedCrossRef 24. Gregory BC, Waag DM: Glanders. In Medical Aspects of Biological Idasanutlin solubility dmso Warfare. U.S Army Medical Department Borden Insitute Textbooks of Biological Warfare; 2007:121–146. 25. Waag DM, Deshazer D: Glanders: New insights into an old disease. In Biological Weapons Defense: Infectious Diseases and Counterbioterrorism. Edited by: Lindler LE LF,

Korch GW. Totowa, New Jersey: Humana Press Inc; 2004. 26. Nierman WC, DeShazer D, Kim HS, Tettelin H, Nelson KE, Feldblyum GSK2118436 in vivo T, Ulrich RL, Ronning CM, Brinkac LM, Daugherty SC, Davidsen TD, Deboy RT, Dimitrov G, Dodson RJ, Durkin AS, Gwinn ML, Haft DH, Khouri H, Kolonay JF, Madupu R, Mohammoud Y, Nelson WC, Radune D, Romero CM, Sarria S, Selengut J, Shamblin C, Sullivan SA, White O, Yu Y, Zafar N, Zhou L, Fraser CM: Structural flexibility in the Burkholderia mallei genome. Proc Natl Acad Sci USA 2004,101(39):14246–14251.PubMedCrossRef 27. Kumar A, Chua KL, Schweizer HP: Method for regulated expression of single-copy efflux pump

genes in a surrogate Pseudomonas aeruginosa strain: identification of the BpeEF-OprC chloramphenicol and trimethoprim efflux pump of Burkholderia pseudomallei 1026b. Antimicrob Agents Chemother 2006,50(10):3460–3463.PubMedCrossRef 28. Harland DN, Dassa E, Titball RW, Brown KA, Atkins HS: ATP-binding cassette systems in Burkholderia pseudomallei and Burkholderia mallei. BMC Genomics 2007, 8:83.PubMedCrossRef RVX-208 29. Tribuddharat C, Moore RA, Baker P, Woods DE: Burkholderia pseudomallei class a beta-lactamase mutations that confer selective resistance against ceftazidime or clavulanic acid inhibition. Antimicrob Agents Chemother 2003,47(7):2082–2087.PubMedCrossRef 30. Dance DA, Wuthiekanun V, Chaowagul W, White NJ: The antimicrobial susceptibility of Pseudomonas pseudomallei. Emergence of resistance in vitro and during treatment. J Antimicrob Chemother 1989,24(3):295–309.PubMedCrossRef 31. Jenney AW, Lum G, Fisher DA, Currie BJ: Antibiotic susceptibility of Burkholderia pseudomallei from tropical northern Australia and implications for therapy of melioidosis. Int J Antimicrob Agents 2001,17(2):109–113.PubMedCrossRef 32.

What unites these viruses, in addition to similar proteomes, is the

presence in each of a cytosine-C5 specific DNA methylase (pfam00145, DNA_methylase, C-5 cytosine-specific DNA methylase; ΦCD119 protein YP_529611.1) and a DNA replication cassette composed of three proteins: a DnaD (primosome recruiting protein, presumably analogous to lambda gpO and P22 gp18; ΦCD119 protein YP_529603.1), a hypothetical protein (misidentified in ΦCD27 as a putative resolvase/integrase and missed entirely in the annotation Pritelivir purchase of ΦCD119) and a single-stranded DNA binding protein. 7. phiKZ-like viruses find more phages φKZ and EL are members of a group of giant phages isolated, to date, only in Pseudomonas species. Their heads are isometric, 120 nm in diameter, and they possess 190 nm-long tails. The phage heads contain an inner body. The DNA of φKZ is over 280 kb in size and has 306 ORFs, most of which are unrelated to ORFS of any known protein [87], while EL contains 201 ORFs within its 211 kb genome [88]. These two phages and Pseudomonas phage Lin68 have recently been proposed as part of a genus “”phiKZ viruses”" [89]. selleck products We now

consider that the differences (number of ORFs, mol%G+C, protein homologs) between φKZ and EL exclude EL from membership in the same genus. Indeed, the recent analysis of novel Pseudomonas phage 201φ2-1 [90] showed this phage to have a strong correlation to φKZ (167 similar proteins), suggesting that it is a true member of the phiKZ virus genus. 8. PB1-like viruses This genus is named after the first isolated member of this group (PB1) [91]. Morphological and DNA-DNA hybridization 4��8C studies by V. Krylov indicated that the following Pseudomonas phages were related: E79, 16, 109, 352, 1214, FS, 71, 337, φC17, SL2, B17 [92]. The sequences of a number of viruses belonging to this genus, namely F8, BcepF1, PB1, 14-1, LBL3, LMA2, and SN (P.-J. Ceyssens, personal communication) have now been completed. None of these phages encodes

a recognizable integrase, suggesting that they are virulent. Phage F8 is one of the Pseudomonas typing phages from the Lindberg set which includes six more similar phages [93, 94]. It possesses a 70-nm wide head with visible capsomers and a 138 nm-long tail, four short straight tail fibers and a base plate that separates from the sheath upon contraction. The tail exhibits no transverse striations, but presents a criss-cross pattern [95]. This criss-cross pattern is a rare feature that has only been observed in phage Felix O1. BcepF1 was isolated from soil by enrichment culture [96] using a Burkholderia ambifaria strain as its host (E.J. Summer and C.F. Gonzalez, unpublished).

Further, CgOPT1 might facilitate incorporation of metabolites or small peptides that BYL719 in vitro can be used as signalling molecules e.g., during plant infection. CgOPT1 was activated in the presence of IAA in a concentration-dependent manner. Transcription was already enhanced at 50 μM IAA and was further enhanced at higher concentrations, with saturation at 500 μM. These concentrations are much higher than the IAA levels in plants but are within the range of IAA amounts produced by C. gloeosporioides [16]. Lack of activation by acetic acid, indole-3-ethanol

(tryptophol) or tryptamine ruled out possible activation of CgOPT1 by auxin-induced changes in pH, or as a general response to indoles. Nevertheless, at this stage it is impossible to determine whether up-regulation of CgOPT1 in the presence of IAA is a check details direct response to IAA or rather, an

indirect response to other changes that might be brought about by IAA. Further, induction by IAA does not necessarily imply that it would be involved in IAA transport, especially because C. gloeosporioides produces large quantities of IAA, so induction might be through endogenous rather than exogenous IAA. In addition to the IAA-induced transcription of CgOPT1, the gene was differentially expressed during fungal development, particularly during spore germination. CgOPT1 transcript could not be detected in resting spores, it was highly induced during germination, and then it declined during mycelium formation. This expression pattern is opposite to that of the vacuolar copper-transporting gene CgCTR2, which is necessary for the initial stages

of germination and is highly expressed in resting spores and down-regulated immediately Thiamet G after spore germination [24]. Therefore, CgOpt1 is probably important during germ-tube formation and elongation, but is not required for the initiation of spore germination. Silencing of the gene provided additional evidence for the involvement of CgOptT1 in development as well as pathogeniCity: cgopt1-silenced mutants displayed reduced sporulation and pigmentation, and were less pathogenic than the wild-type strain. These pleiotropic effects suggest GSK1120212 datasheet association of CgOpt1 with several different processes. IAA appears to have an enhancing effect on processes such as sporulation, spore germination, and germ-tube elongation. However, the effects of IAA vary with experimental conditions, and opposite results might be obtained. In our sporulation assay, we took special care to eliminate possible interference and side effects from experimental parameters such as solvent, medium, or light. IAA was applied to filter paper, the ethanol was evaporated, and then the filter was placed between two layers of agar to avoid direct contact with the fungus. Additionally, because sporulation is enhanced by light, the experiments were conducted under both light and dark conditions.

In some cases, the products of the first PCR were further amplified with repeated alternation of one high annealing temperature (58°C) cycle and one moderate annealing temperature (44°C) cycle in which the randomized primer was replaced with primer Fix5-29-2 (5′ CTA CAC

GAG TCA CTG CAG 3′), a primer sequence that was identical to selleck compound 18 of the 21 5′ terminal nucleotides of the randomized primer. DNA sequences obtained were used as query probes to search the E. coli K-12 genome sequence database for identifying transposon insertion sites. Lethality of environmental stresses The susceptibility of bacterial cells to UV irradiation was tested by applying serial dilutions of mid-log phase (OD600 = 0.3 ~0.5) cultures to agar plates that were irradiated

with an Ultraviolet Crosslinker CL-1000 (UVP) at a dose of 2000 μJ/cm2 in a dark room. The plates were then covered with aluminium foil and incubated overnight at 37°C. A1155463 For other stressors, mid-log phase cells were treated with 2 mM H2O2 (cells were resuspended in 0.9% saline before treatment), 10% sodium dodecyl sulfate (SDS), or high temperature (52°C) for 15 min. Serial dilutions were then prepared, and 10-μl of aliquots from the dilutions were spotted in triplicate on plates and incubated at 37°C overnight. The sensitivity of cells to the lethal effects of these stressors was expressed as percent survival of treated cells relative to that of Sepantronium molecular weight untreated cells determined at the time of treatment (LD90 could not be used because many of the mutant-stressor combinations did not reduce survival sufficiently). Complementation of hyperlethality by cloned genes All DNA manipulations were carried out according to procedures described previously Farnesyltransferase [13]. The emrK and ycjU genes

with their promoter regions were amplified by PCR using chromosomal DNA isolated from DM4100 as templates and cloned into pBR322. The primers used were 5′-TAG GAA TTC ATC TCC CTT CTC CCT GTA GT-3′ and 5′-TAA GTC GAC ATT CTT TGT GCC AAC CTG-3′ for emrK, and 5′-TGC GAA TTC CTG CTG ACC CAA AGT TAT-3′ and 5′-TAG CTG CAG TCA CCT CTT TGG CGA TT-3′ for ycjU. Plasmids containing wild-type ycjW, yrbB, and ybcM were from the ASKA library [17]. The plasmids were placed in the corresponding mutant strains, as well as in the wild-type strain DM4100, by electroporation. The strains harboring the plasmids were then tested for nalidixic acid lethality. For ycjW, yrbB, and ybcM, the expression was induced by adding 1 mM of IPTG 2 hr before nalidixic acid treatment. Results and Discussion Screening for mutants exhibiting hyperlethality to nalidixic acid During the course of evolution, bacteria have acquired a variety of genetic networks that provide protection from stress. For example, in E. coli more than 30 two-component systems detect the environment and cause changes in the expression of large numbers of genes [18].

syltensis www.selleckchem.com/products/bmn-673.html DSM 22749T was grown in SYMHC medium under an initial headspace gas atmosphere of 20% (v/v)

O2, C. halotolerans DSM 23344T in SYM medium containing 0.5% (v/v) Tween 80 under air atmosphere and P. rubra DSM 19751T in defined medium containing 5 mM DL-malate under an initial headspace gas atmosphere of 12% (v/v) O2. The amount of produced BChl a is symbolized by red bars for L. syltensis DSM 22749T, blue bars for C. halotolerans DSM 23344T and green bars for P. rubra DSM 19751T. Each experiment was performed in duplicate and the shown values represent means of two measurements. The ratio of photosynthetic pigments depends on the redox conditions The pigment stoichiometry in L. syltensis varied widely and https://www.selleckchem.com/products/c646.html depended on the incubation conditions. Under conditions of a reducing environment (excess substrate, low oxygen concentrations, darkness) the determined BChl a/spirilloxanthin ratios were below one, whereas under oxidative stress (substrate limitation, high oxygen concentrations, illumination with blue

light) the production of spirilloxanthin was inhibited and pigment ratios reached values above five (Figure 4). A similar interrelationship was previously found in C. litoralis[15], whereas the variation of pigment ratios in C. halotolerans and P. rubra did not correlate linearly with the environmental redox Rutecarpine conditions. Especially, in P. rubra the BChl a/spirilloxanthin ratios reached higher values under optimal conditions for expression of the photosynthetic apparatus as under suboptimal conditions, irrespective of the environmental redox conditions being too high or too low for optimal pigment expression. It is noteworthy, that in these strains

the observed variability of the pigment stoichiometry was independent of the total amount of produced photosynthetic pigments, which could indicate that the ratio and amount of produced photosynthetic pigments are controlled by two independent regulatory mechanisms. Figure 4 Pigment stoichiometry in cells grown under various incubation conditions. The determined photosynthetic pigment ratios are based on results obtained in the experiments shown in Figures 1B and 3. Bars illustrate pigment ratios obtained upon incubation with different amounts of a distinct carbon source and line graphs represent values determined upon growth under illumination with different light sources. Bars and graphs in red represent values of L. syltensis DSM 22749T, values of C. halotolerans DSM 23344T are given in blue colour and values of P. rubra DSM 19751T in green.

The measurement data, for which the moment of the force was less than 100 μNm, were rejected. The original electrorheological system designed for HAAKE MARS 2 is not equipped with any diagnostic tool allowing to determine whether the system is working properly. It is not possible to check whether the sample is actually located in an electric field or not. Furthermore, before each series

of measurements, the multimeter Rigol DM 3064 (Rigol, Beijing, China) was pinned to the rotor (Figure 4(D)). In this way, it was checked selleckchem whether the voltage is correctly supplied to the rotor, and we are sure that each sample was measured in an electric field. After completing all the calibration steps and finding that they were all carried out properly, the measurement of the earlier prepared sample was started. The sample of nanofluid with an automatic pipette on the lower measurement plate was applied, volume of the sample was 2.7 cm3. On the power supply unit, the desirable voltage was set, and then it was turned, Selleck NCT-501 thereby the

voltage to the rotor was brought. The first measurement was performed in the absence of voltage. Afterward, the sample has been tested for the following values of voltage: 500, 1,000, 1,500, and 2,000 V. The measurements of dynamic viscosity curves were performed in a step procedure in the CR mode at the shear range from 1 to 1,000 s −1 in the logarithmic scale. Each of the 30 steps took 100 s, wherein the value of the shear rate acting on the sample at that time was constant. The measurement points were collected on the basis of the results obtained in the last 3 s of a single step. In the course of measurements, it was not possible to maintain a constant temperature because an imposed mode of operation of the assembled system has made it impossible. A thixotrophic behavior was observed upon measurement in CR mode performed in three steps. First sample was measured with increase of shear rate from 1 to 1,000 s −1 in a time of 600 s. The second step was shearing the sample with a constant shear

rate of 1,000 s −1 used for 600 s. The third stage of experiment was the measurement with shear rate decreasing from 1,000 to 1 s −1 in 600 s. In view of the fact next that the measuring geometry was an air-cooled system, it was not possible to achieve a constant temperature during the measurements. The system was purged with air at room temperature, and the lab has efficient air conditioning system. Nevertheless, temperature spread reached 1.5°C. Results and discussion Pressure measurement A study to determine the dynamic viscosity curve of MgAl2O4-DG nanofluid under anisotropic high pressure was conducted. The experiment was performed on two samples of different mass concentrations of nanoparticles in nanofluid, namely 10 and 20 wt.%.

2005). Materials and methods Design and population For this cross-sectional study, 1,035

male and 905 female workers (Table 1) were chosen from the MSNS cohort who completed both the baseline and follow-up MSNS questionnaires. Selleck VX-689 The MSNS cohort consists of men and women, residing in the city of Malmö (240 000 inhabitants), Sweden, who were between 45 and 65 years of age in 1991, and who were recruited into the larger Malmö Diet and Cancer Study (MDCS) (Manjer et al. 2001) from February 1992 to December 1994. The cohort was recruited during the major political and financial crisis period of the Swedish society, for instance, unemployment rate dramatically increased from 1.7 % in 1990 to 9.4 % in 1994 (OECD 2006). Comparison with a public health survey (Lindström et al. 2001), covering 74.6% of the same age cohort, suggests that the MDCS population AMN-107 sample was selected toward better health than in the general population (Manjer et al. 2001). The participants in the original MDCS (n = 14,555; participation rate, 40.8%) filled in a baseline (T 1) questionnaire.

After about 1 year (mean follow-up time, 403 days; standard deviation, 49), a follow-up (T 2) questionnaire was mailed to the baseline participants. The follow-up questionnaire was returned by 12,607 men and women. Non-respondents were younger, less educated, and than respondents, but there were no gender differences between respondents and non-respondents. Table 1 Distributions

of socio-demographic variables, psychosocial work characteristics, and psychological distress (GHQ case) in the Swedish male (n = 1,035) and female (n = 905) workers Variables Category Men (%) Women (%) Age (years) 45–54 61.0 62.8 55–64 39.0 37.2 Education (years) Up to 12 70.6 68.4 Over 12 29.4 31.6 Marital status Married 75.9 62.8 Non-married 24.1 37.2 Origin of country Swedish 92.8 93.4 Non-Swedish 7.2 6.6 Cross-sectional (at T 1) Low job control 30.5 46.6 High job demands 51.2 45.9 Low social support at work 50.4 44.9 Cross-sectional (at T 2) Low job control 33.8* 55.2** High job demands 55.2* 48.8 Low social support at work 49.8 49.6** Cross-time (both at T 1 and T 2) Consistent mafosfamide C, D, and S across times 46.8 44.8 Changed C, D, or S across times 53.2 55.2 Family-to-work conflict (at T 2)   10.7 18.5 Stress from outside-work problems (at T 2)   20.5 31.6 Worry due to family members (at T 2)   7.5 21.0 Number of days on sick leave (at T 2) ≤3 days 87.1 79.2 ≥4 days 12.9 20.8 GHQ case (at T 2)   11.2 19.4 C job control, D job demands, S social support at work. * p < 0.05; ** p < 0.01 when compared by repeated measures t-tests with values at T 1 Unfortunately, information on general psychological distress was not measured in the baseline study so it was not possible to perform a longitudinal analysis.

The as-synthesized CuGaS2 nanoplates adopt a unique crystal structure of wurtzite-zincblende polytypism. In the growth process of CuGaS2 nanoplates, copper sulfides firstly formed, and then the as-formed copper sulfides

were gradually phase-transformed to CGS nanoplates with proceeding of the reaction. The optical bandgap energy of the nanoplates is estimated to be approximately 2.24 eV. Our results will aid in the application of two-dimensional CuGaS2 nanoplates and the synthesis of other multicomponent sulfide nanomaterials. Acknowledgements CH5183284 This work was supported by the National Natural Science Foundation of China (No. 91022033, No. 21171158), and National Basic Research Program of China (2010CB934700). Electronic supplementary material Additional file 1:

Three crystal structure models of CuGaS2 and an XRD pattern of an intermediate sample. Figure S1. Three crystal structure models of CuGaS2 (a) tetragonal chalcopyrite structure; (b) cation-disordered cubic zincblende modification, (c) cation-disordered hexagonal wurtzite phase. Figure S2. XRD pattern of a sample collected at 220°C for 0 min. In the present case, Cu2-xS (JCPDS 23–0959) seems to contribute to the experimental pattern. (DOC 872 KB) References 1. Zhong H, Bai Z, Zou B: Tuning the luminescence properties of colloidal I–III–VI semiconductor nanocrystals for optoelectronics and biotechnology applications. J Phys Chem Lett 2012, 3:3167–3175.CrossRef 2. Aldakov D, Lefrancois A, Reiss P: Ternary and quaternary metal chalcogenide nanocrystals: synthesis, properties and applications. J Mater Chem C 2013, BMS907351 1:3756–3776.CrossRef 3. Panthani MG, Akhavan V, Goodfellow B, Schmidtke JP, Dunn L, Dodabalapur A, Barbara PF, Korgel BA: Synthesis of CuInS 2 , CuInSe 2 , and Cu(In x Ga 1- x )Se 2 (CIGS) nanocrystal “inks” for printable photovoltaics. J Am Chem Soc 2008, 130:16770–16777.CrossRef 4. Tsuji

I, Kato H, Kudo A: Photocatalytic hydrogen evolution on ZnS-CuInS 2 -AgInS 2 solid solution photocatalysts with wide visible light absorption bands. Chem Mater 2006, 18:1969–1975.CrossRef 5. Song WS, Yang H: Efficient Nintedanib (BIBF 1120) white-light-emitting diodes fabricated from highly fluorescent copper indium sulfide core/shell quantum dots. Chem Mater 2012, 24:1961–1967.CrossRef 6. Pons T, Pic E, Lequeux N, Cassette E, Bezdetnaya L, Guillemin F, Marchal F, Dubertret B: Cadmium-free CuInS 2 /ZnS quantum dots for sentinel lymph node imaging with reduced toxicity. ACS Nano 2010, 4:2531–2538.CrossRef 7. Xie RG, Rutherford M, Peng XG: Formation of high-quality I-III-VI semiconductor nanocrystals by tuning relative reactivity of cationic precursors. J Am Chem Soc 2009, 131:5691–5697.CrossRef 8. Pan DC, An LJ, Sun ZM, Hou W, Yang Y, Yang ZZ, Lu YF: Synthesis of Cu-In-S ternary nanocrystals with tunable structure and composition. J Am Chem Soc 2008, 130:5620–5621.CrossRef 9.

The source meter was connected to both metallic pads to apply an ac electrical current (I 0), as shown on the right side of Figure 3a. I 0 with an angular modulation frequency of 1ω was applied to generate Joule heat and temperature fluctuations at a frequency of 2ω. The resistance of the narrow metal strip is proportional to the temperature that leads to a voltage fluctuation V = IR of 3ω across the specimen. A lock-in amplifier (A − B mode) connected to the two electrodes in the middle receives the 3ω voltage fluctuation along the narrow metal strip;

that gives the information about the thermal conductivity of the films. A few early studies by our group showed that the thermal conductivities of 1D silicon carbide nanowires (SiC NWs) [16] and Bi NWs [20] were measured successfully with our experimental setup and equipment. For the measurement of the thermal conductivity VX-809 in vitro selleck products of nonporous and nanoporous

Bi thin films, the third-harmonic voltage (V 3ω ) must be plotted against the natural logarithm of the applied frequencies ln ω resulting in a linear relationship. The thermal conductivity is then determined from the slope in the linear region. Figure 3b shows the linear regions of the plot of V 3ω versus ln ω at various applied ac currents ranging from 5 to 10 μA. The characteristic parameters of the linear region calculated from the graphs, as well as other required information, are summarized in Table 1. The difference between two V 3ω values (i.e., V 3ω1 and V 3ω2) is equated to the temperature drop across the Bi film and is used to calculate the cross-plane thermal

conductivity, which is defined by the following Equation: (1) Figure 3 Thermal conductivities of both nonporous and nanoporous Bi thin films. (a) Experimental setup and circuit (left side) and corresponding circuit (right side), equipped with thermal management and electrical measurement systems for thermal conductivity measurements via the 3ω method at room Sulfite dehydrogenase temperature. (b) Linear regions of the third-harmonic voltage versus the applied frequency at various applied ac currents ranging from 5 to 10 μA. (c) Thermal conductivities of nonporous Bi thin films in terms of applied ac currents. Table 1 Summary of the characteristic measuring parameters I 0 (μA) V 0 (mV) κ (W/m·K) I 0 (μA) V 0 (mV) κ (W/m·K) 5.0 564.38 1.76 × 104 2.90 7.0 601.34 1.45 × 104 2.90 5.5 560.23 1.82 × 104 2.94 8.0 627.17 1.24 × 104 2.80 6.0 565.74 1.77 × 104 2.94 9.0 618.19 1.27 × 104 2.76 6.5 607.28 1.41 × 104 2.89 10.0 630.10 1.17 × 104 2.67 The parameters used for the calculation of the thermal conductivity of nonporous Bi thin films as a function of the applied electrical ac current. R 0 , dR/dT, and l were determined to be 39.38 Ω, 53.64 mΩ/K, and 3 mm, respectively.

Reshchikov MA, Sabuktagin S, Johnstone DK, Morkoc H: Transient photovoltage in GaN as measured by atomic force microscope tip. J Appl Phys 2004, 96:2556. 10.1063/1.1774245CrossRef Competing interests The authors declare that they have no competing interests. Authors’ contributions PG and

KR fabricated the porous silicon and Ni-filled porous silicon samples, and PC and YS performed the surface photovoltage transient measurements. All authors discussed the data and prepared the manuscript. All authors read and approved the final manuscript.”
“Background In the recent years, noble metal nanoparticles, especially gold nanoparticles (AuNPs), have attracted great interest and wide attention. AuNPs have proven to be a versatile platform in many areas Akt inhibitor such as catalysis, biosensing, VX-661 optoelectronics, biological imaging, and therapeutic techniques [1–3]. Recently,

the preparation and potential applications of AuNPs are becoming increasingly popular among researchers due to their distinctive optical properties, particularly tuneable surface plasmon resonance. Up to now, a number of chemical and physical methods for synthesis of metal nanoparticles have been reported, such as chemical reduction, electro-reduction, photo-reduction, and heat evaporation [4–6]. In most cases, the synthetic processes either involve the use of borohydride, hydrazine, citrate, etc. or require rather complex procedures or rigorous conditions, followed by surface modification with some protecting ligands like thiols and oleic acid. Thus, both toxicity and high cost make these materials less promising in industrial and biological applications. To address these problems, biosynthesis of biological materials has received considerable attention. Compared

to traditional methods, biosynthesis has many advantages by decreasing the use of toxic chemicals in the process and eliminating risks in industrial, pharmaceutical, and biomedical applications. To date, a broad range of biological materials has been introduced for the biosynthesis of metal nanoparticles including phytochemicals (polyphenol buy Erastin extract, catechin, lemongrass leaf extract, aloe extract, and fruit extracts) [7–13], microorganisms (bacteria and yeast) [14–16], protein [17, 18], peptide [19, 20], and polysaccharide [21–24]. Among the various biological materials, polysaccharides are emerging as an important natural resource for the synthesis of metal nanoparticles. In such processes, polysaccharides usually act as a reducing agent or stabilizer because of their special structure and properties. Since Raveendran et al. proposed a completely green method for preparation of silver nanoparticles with starch [23], many researchers have investigated the effects and mechanism of various polysaccharides on the formation of metal nanoparticles, such as cellulose, chitosan, alginic acid, hyaluronic acid, and agarose [21–25].