Therefore, it appears that Δphx1/Δphx1 diploid cells are defective in Dinaciclib completing the first meiotic division [28]. The sporulation efficiency was determined by counting the number of asci among at least 500 cells counted. Compared with the wild-type cells which demonstrated up to about 50% sporulation efficiency, the mutant diploids exhibited only about 10% efficiency (Figure 6B). Figure 6 Sporulation defect of  Δphx1/Δphx1  mutant diploid. (A) The wild type and mutant diploid cells were grown to the stationary phase (OD600 of 8–9; ~70 h culture) in EMM at 30°C and examined

under the microscope (Axiovert 200 M, Carl Zeiss). Representative DIC and DAPI images were presented. (B) Quantification of the sporulation efficiency. Diploid

cells grown for different lengths of time at 30°C in EMM were examined under the microscope to count the number of spore-containing asci. The percentage of asci formation among a total of more than 500 counted cells was presented as sporulation efficiency. Cells grown from three independent cultures were examined Ilomastat research buy to obtain average values. Conclusions Phx1 is a homeobox-containing protein whose synthesis is elevated during the stationary phase. It resides primarily in the nucleus and contains the transcriptional activating ability when bound to DNA, supporting its role as a transcriptional regulator. Its synthesis is induced by nutrient starvation, various oxidative stresses, and by heat shock, coinciding with its role in long-term survival and stress resistance. It is also critically required for the formation of meiotic spores from diploid cells. Taken all these observations together, it is quite clear that Phx1 is a novel regulator that confers cells with fitness to survive during the nutrient-lacking stationary phase. Sorafenib molecular weight It enhances viability and ability to form spores for the future, most likely through reprogramming gene expression pattern. Elucidation of the signaling pathway as well as its target genes will be of interest to understand the mechanism of long-term survival and sporulation specific in this fungi as well

as common across other organisms. Methods Strains, plasmids and culture media We used ED665 (h − ade6-M210 leu1 32 ura4 D18), ED668 (h + ade6 M216 leu1 32 ura4 D18), JH43 (h − ade6 M210 leu1 32) and 972 (h – ) strains as the wild type [30]. To disrupt the phx1 + gene, we replaced 2200 nt of the phx1 + ORF in pUC18-phx1 + recombinant plasmid with a ura4 + cassette [31]. Digestion of pUC18-Δphx1::ura4 + with ClaI/BglII generated a 4.3 kb fragment, which was used to transform wild-type cells to create mutant strains ESX5 (Δphx1::ura4 + in ED665) and ESX8 (Δphx1::ura4 + in ED668). Transformants were confirmed by both Southern hybridization and PCR. We also generated the prototrophic Δphx1 mutant without auxotrophic markers.

In the obtained spectra, the Bragg peak position and their intensities were compared with the standard JCPDS files. The result shows that the particles have a cubic structure. The size of the silver nanoparticles was found E7080 ic50 to be 5 nm. The XRD pattern thus clearly indicated that the AgNPs formed in the present synthesis were crystalline

in nature. Pasupuleti et al. and other reserachers observed a similar XRD pattern of silver nanoparticles using Rhinacanthus nasutus leaf extract. Some unassigned peaks (*) have also been observed suggesting that the crystallization of bio-organic phase [26, 30–33]. Figure 2 XRD pattern of silver nanoparticles synthesized using A. cobbe leaf broth. FTIR spectra of AgNPs The FTIR spectra were recorded to identify potential biomolecules that contributed to the reduction of the Ag+ ions and to the capping of the bioreduced AgNPs [33]. Figure 3A shows FTIR spectra of A. cobbe leaf extract observed at 3,420 and 1,730 cm-1 are characteristic of the O-H and C = O stretching modes for the OH and C = O groups possibly

secondary metabolites of leaf extract. Figure 3B shows the FTIR spectra of purified silver nanoparticles, the presence of bonds due to O-H stretching (around 3,441 cm-1), C = O group (around 1,636 cm-1), the peak at 1,636 cm-1 could be assigned to the vibrations due to amide I band present in the proteins and the peak around 1,384 cm-1 assigned to geminal methyl group. The minor band 1,054 cm-1 corresponds to C-N stretching alcohols, ID-8 the band 594, and 887 cm-1 regions for C-H out of plane AZD5582 in vivo bend, which are characteristics of aromatic phenols [26]. The spectra also illustrate a prominent shift in the wave numbers corresponding to amide I band (1,636 cm-1) and amide II band (1520 cm-1) linkages, validates that free amino (-NH2) or carboxylate (-COO-)

groups in compounds of the A. cobbe leaf extract have interacted with AgNPs surface making AgNPs highly stable. The energy at this vibration is sensitive to the secondary and tertiary structure of the proteins. The band observed at 3,441 cm-1 was characteristic of - NH stretching of the amide (II) band. Several bands between 2,000 cm-1 to 3,000 cm-1 were absent, which could be attributed to protein precipitation occurring during the reduction and stabilization of the AgNPs [33]. We have observed some additional peaks of silver nanoparticles located at around 1,054 cm-1 can be assigned as the C-N stretching vibrations of amine. This present result obtained from A.cobbe agrees with those reported previously for Rhinacanthus nasutus [33], Thevetia peruviana [34], latex of Jatropha curcas [35]. Our observation lends support to a previous study in which formation of spherical silver nanoparticles was reported by using various plant extracts. Further, the FTIR patterns of A.

It can be observed that, under 2 W/cm2 laser irradiation, the

V CPD values change slightly for all the three samples, but they increase obviously when the laser intensity increase up to 4 W/cm2 and above. Also, the increase magnitude is different for the three types of NRs. The increase of V CPD with laser intensity is most significant for NR3, similar to the increase of trapped charges. Similar surface potential variation by photogenerated charges has been obtained by Kelvin potential force Integrin inhibitor microscopy (KPFM) [26, 27]; it was declared that the positive (negative) shift in surface potential with laser corresponds to an increase in hole (electron) density. Thus, the positive shift in V CPD with laser intensity in our experiments can also be attributed to the increase of trapped hole density, which is consistent with the above results of charge density. As V CPD equals to (ϕ tip − ϕ sample) / e, the results declare that the work function of Si NR decrease upon laser irradiation should be due to the photogenerated holes trapped in NRs. The reason why positive charging measured on n-type Si NRs is not very clear, and further studies are required to get a clear mechanism. Vactosertib molecular weight The possible mechanism may be suggested to the tunneling of photogenerated electrons to the substrate and trapping the holes in the NRs. In previous studies on the photoionization of an individual CdSe nanocrystals [16, 28], it was

found that a significant fraction of nanocrystals was positively charged and it was attributed to the tunneling of the excited electrons into the substrate. They assumed that the hole tends to be localized in the nanocrystal, while the electron is much more delocalized, with a nonnegligible fraction of the electron density outside the nanocrystal. Another possibility arises from that the holes can be captured at Si-Si bonds according to the reaction ≡ Si-Si ≡ + h → ≡Si+ + · Si≡, as reported in reference [29]. By adopting the above viewpoint, it can be suggested that when Si NRs are irradiated, free charges are

photogenerated after dissociation of of the excitons. Due to the tunneling of photoelectrons and/or capture of holes, the Si NRs would be positively charged. To see the dynamics of charging and decharging, the time evolution of the EFM phase shift with the laser ON and OFF is present in Figure 4a,b for NR2 and NR3, respectively. As the change of phase shift with laser irradiation is too small for NR1, it is not given here. When the laser is turned on, the EFM phase shifts of both NR2 and NR3 moves to the more negative values, and the signal follows a monotonic decay to a new equilibrium value, corresponding to the charge generation and trapping process. The experimental curves can be fitted with single exponential decay, as shown in the left insets in Figure 4, giving a time constant of 7.6 and 13.6 s for NR2 and NR3, respectively.

Experimental design For sensitivity and efficiency

analysis, we tested each fungal genomic DNA in three 10-fold serial dilutions in triplicate reactions using the optimized 18S qPCR conditions as described above. Using the Ct-value results, we calculated FungiQuant’s reaction efficiency and correlation coefficient for each species tested. Limit of detection (LOD) validation MI-503 mouse Experimental design To determine the LOD of FungiQuant for detecting low concentration fungal DNA, we analyzed no-template controls (i.e., molecular grade H2O), background control (i.e., 10 ng, 50ng, and 150ng human DNA), as well as three low concentration of fungal DNA: a) 1.8 copies, b) 5 copies, and c) 10 copies of fungal 18S rRNA gene. Each template was analyzed in 96 replicates in 10 μl and 5 μl reactions using conditions as described above. Data Analysis Experimental results using all templates were assessed for: a) the proportion of determined and undetermined values and b) the Ct-value distribution among those replicates with determined values. Using the specificity associated with the background controls, which provides the most likely source of contamination and signal noise, the probability of each triplicate results was calculated under the null hypothesis that

the sample contained no positive target. The analysis was performed separately

Nutlin-3 chemical structure for each reaction volume using an alpha level of 0.05 to determine results inconsistent with the null. Analysis using the Ct-value from samples with positive amplification was also performed using a non-parametric median test to determine if 1.8 copies, 5 copies, or 10 copies templates could be differentiated from the no-template and background controls. The Ct-value data was further assessed to determine if the average Ct-value is an appropriate estimate of the true Ct-value in low concentration samples for reporting and analysis. FungiQuant laboratory quantitative validation Experimental design We followed the Minimum Information for publication of Quantitative real-time PCR Experiments, or the MIQE guidelines, whenever applicable [31]. We performed additional MTMR9 tests to evaluate FungiQuant performance when background human DNA is present. We included seven template conditions: plasmid standards alone and plasmid standards with 0.5 ng, 1 ng, 5 ng, and 10 ng of human DNA per reaction in 10 μl reactions, as well as plasmid standards alone and plasmid standards with 1 ng human DNA in 5 μl reactions. For each condition assessed, we performed three qPCR runs to assess reproducibility. In each run, three replicate standard curves were tested across the 384-well plate to assess repeatability.

coli K12, the majority of persister studies have focused on three bacterial taxa: Mycobacterium tuberculosis, Pseudomonas

aeruginosa, and Staphylococcus aureus. M. tuberculosis is known for its recalcitrance to antibiotic treatment [14–16], and genetic studies have shown that toxin overexpression exhibits drug-specific effects: toxins that increase persistence in one antibiotic do not necessarily increase persistence in other antibiotics [15]. This contrasts with results in E. coli K12 outlined above, in which persistence is generally characterized Selleck RAD001 by multidrug tolerance [9, 11]. In clinical settings, P. aeruginosa mutants that produce increased persister fractions (up to 100-fold above wildtype) have been isolated [4]; however, the genetic mechanisms causing increased persister fractions are not well understood. Finally, in S. aureus, although some research on the influence of metabolism on persister formation [17], genetic studies STA-9090 chemical structure are lacking. Most studies on persister formation have focused on strains

harboring mutations that increase or decrease persister frequency. However, one recent study [18] tested how persister formation differs among strains of bacteria. In this study, mammalian commensal and pathogenic E. coli isolates were found to exhibit substantial variation in the fraction of persisters that are present in exponentially growing populations of cells. In addition, it was found that the fraction of persisters that survived treatment in one antibiotic was uncorrelated with the fraction surviving in a second antibiotic. However, without Farnesyltransferase a quantitative model of persistence, this result cannot unambiguously exclude other explanations, such as differences in the death rates of cells between isolates. Here, using a collection of environmental isolates of E. coli, we examine

variation in the frequency of persister cells in naturally occurring strains. In order to consistently measure persister fractions, we use a mathematical model to derive quantitative and reliable estimates of the fraction of persisters in each population. Our quantitative set of data corroborates the results of the previous study on commensal and pathogenic E. coli isolates [18], showing that there is substantial variation in the fraction of persister cells among environmental isolates of E. coli. In addition, we show that the fraction of cells that survive drug treatment in one drug is uncorrelated with the fraction surviving in a second drug. Importantly, we show that this lack of correlation extends to drugs have nearly identical modes of action. Finally, by using combinations of antibiotics, we provide evidence that for any single strain, there may be a subset of persister cells that are recalcitrant to treatment with any antibiotic.

Rank) named in the Materials and Methods. We identified four genes strongly up-regulated by iron limitation [9] and compared their expression between

drip-flow biofilm, three standard comparison data sets [15, 18, 20], and a positive control in which the bacterial culture was deliberately iron-limited (Figure 3C) [22]. All four genes were highly ranked in the iron-limited positive control. The expression rank of these four genes in the drip flow biofilm was consistently lower in comparison to the reference data sets. These data suggest that bacteria

in the drip-flow BIBW2992 mouse biofilm as grown in this study did not experience limitation for iron. The concentration of iron in the medium, added in the form selleckchem of ferrous ammonium sulfate, was 1.5 μM. From the literature, we identified four genes that are induced by the presence of nitrate in the medium, either under aerobic or anaerobic conditions [25]. The expression rank of these genes is compared in Figure 3D. The rank for the drip-flow biofilm for all four genes was higher than the three standard comparison data sets and lower than a nitrate-amended positive control. The medium used to grow the biofilm did not contain added nitrate. Figure 3E

presents a comparison of gene rank for four growth phase responsive genes. Three genes associated with stationary phase, cspD, rmf, and rpoS, [26–29] were very highly ranked in both our drip flow biofilm and the comparison data set that was sampled in stationary phase. The fourth gene whose expression is associated with early exponential phase growth, fis, [26, 29] showed the inverse ranking. Mannose-binding protein-associated serine protease The biofilm and stationary phase culture had similar ranks for the fis gene, while the two systems in which bacteria were rapidly growing had much higher ranks. These comparisons suggest that many of the cells in the biofilm exhibit stationary phase character. To further explore the potential relationship between transcript levels for these genes and growth state, we plotted gene rank for fis and rpoS as a function of specific growth rate, where a growth rate was reported or optical density versus time data permitted a quantitative estimation (not shown).

Antimicrob Agents Chemother 2005, 49:3789–3793.CrossRefPubMed

60. Clinical and Laboratory Standards Institute: Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. approved standard. 7th ed. M7-A7. Wayne, PA 2006. 61. Charbonnier Y, Gettler B, Francois P, Bento M, Renzoni A, Vaudaux P, Schlegel W, Schrenzel J: A generic approach for the design of whole-genome oligoarrays, validated for genomotyping, deletion mapping and gene expression analysis on Staphylococcus aureus. BMC Genomics 2005, 6:95.CrossRefPubMed 62. Scherl A, Francois P, Charbonnier Y, Deshusses JM, Koessler selleck inhibitor T, Huyghe A, Bento M, Stahl-Zeng J, Fischer A, Masselot A, Vaezzadeh A, Galle F, Renzoni A, Vaudaux P, Lew D, Zimmermann-Ivol CG, Binz PA, Sanchez JC, Hochstrasser DF, Schrenzel J: Exploring glycopeptide-resistance in Staphylococcus aureus : a combined proteomics and transcriptomics approach for the identification of resistance-related markers. BMC Genomics 2006, 7:296.CrossRefPubMed 63. Koessler T, Francois P, Charbonnier Y, Huyghe A, Bento

M, Dharan S, Renzi G, Lew D, Harbarth S, Pittet D, Schrenzel J: Use of oligoarrays for characterization of community-onset methicillin-resistant Staphylococcus aureus. J Clin Microbiol 2006, 44:1040–1048.CrossRefPubMed 64. Garzoni C, Francois P, Huyghe A, Couzinet S, Tapparel C, Charbonnier Y, Renzoni A, Lucchini S, Lew DP, Vaudaux P, Kelley WL, Schrenzel J: A from global view of Staphylococcus aureus whole genome expression upon internalization in human epithelial selleck screening library cells. BMC Genomics 2007, 8:171.CrossRefPubMed 65. Nagarajan V, Elasri MO: SAMMD: Staphylococcus aureus microarray meta-database. BMC Genomics 2007, 8:351.CrossRefPubMed

66. Vaudaux P, Francois P, Bisognano C, Kelley WL, Lew DP, Schrenzel J, Proctor RA, McNamara PJ, Peters G, Von Eiff C: Increased expression of clumping factor and fibronectin-binding proteins by hemB mutants of Staphylococcus aureus expressing small colony variant phenotypes. Infect Immun 2002, 70:5428–5437.CrossRefPubMed Competing interests The authors declare that they have no competing interests. Authors’ contributions PV, BF, WLK, and DL were involved in the study design. BF performed the experimental study and acquisition of data. BF and PV performed data analysis and wrote the final draft of this paper. FG, RAP, and DL provided input into subsequent drafts and iteration of this manuscript. All authors read and approved the final manuscript.”
“Background Bacterial vaginosis (BV) is one of the most common reasons for women to seek medical attention; the underlying cause of BV is controversial. Women with BV are at higher risk for preterm delivery, pelvic inflammatory disease (PID) and acquisition of HIV [1–5].

CrossRef 26. Wagner CD, Riggs WM, Davis LE, Moulder JF: Handbook of X-Ray Photoelectron Spectroscopy. Eden Prairie: Perkin-Elmer Corporation; 1979. Competing interests The authors declare that they have no competing interests. Authors’ contributions MQG and YLX designed the experiments. MQG, YB, and FX carried out the experiments and performed data analysis. MQG wrote the paper.

All authors read and approved EVP4593 the final manuscript.”
“Background High-brightness deep ultraviolet light-emitting diodes (UV LEDs) have attracted much attention in areas of air/water sterilization and decontamination, bioagent detection and natural light, identification, UV curing, and biomedical and analytical instrumentation [1]. To date, the maximum external quantum efficiency (EQE) for commercialization of deep UV LEDs is 3% at the wavelength of 280 nm [2, 3]. Various reasons can account for the poor EQE, mainly such as relatively low-resistance ohmic contacts, low hole concentration in p-type AlGaN layer, and the absence of transparent conductive PRI-724 oxides (TCOs) electrode in the deep UV wavelength region [4, 5]. In particular, it is believed that the development of high-performance TCOs electrode in the deep UV region is a key to increase the EQE of UV LEDs.

Conventionally, indium tin oxide (ITO), which exhibits high conductance and good transparency in a visible region, has been widely used as the TCOs electrodes in LEDs and solar cells [6, 7]. However, it has an opaque property in the deep UV (<300 nm) region due to a small bandgap (approximately 3.2 eV), and hence, new TCO materials need to be explored for deep UV LEDs. The wide bandgap materials such as SiO2, Si3N4, HfO2 are attractive as TCOs for deep UV LEDs because of their high transmittance in deep UV regions, but it is difficult to provide electrical conductivity into these materials. In the meantime, the gallium oxide with β phase (β-Ga2O3) having a large optical bandgap of 4.9 eV has been reported as a deep-UV TCO material [8] because its conductivity PtdIns(3,4)P2 can be improved by thermal annealing, impurity doping,

or incorporating some conducting paths using SWNTs. The Ga2O3 film has also excellent adhesion to GaN surfaces [9]. For example, since undoped Ga2O3 film has insulating properties (i.e., conductivity (σ) <10-9 Ω-1 · Cm-1), it was doped with tin (Sn) atoms to increase the conductivity at the expense of optical transmittance. For 3 mol% Sn-doped Ga2O3 films, the conductivity was increased up to 375 Ω-1 · Cm-1 (42 Ω/square) but the transmittance decreased to approximately 15% in the deep UV region (280 nm) [10]. In order to improve the low optical properties, several groups have reported synthesized TCO layer by wet-based nanoparticles (NPs), such as ITO, indium zinc oxide (IZO), antimony zinc oxide (AZO), antimony tin oxide (ATO), etc. [11–14]. This small particle size (i.e.

Bishop EJ, Shilton C, Benedict S, Kong F, Gilbert GL, Gal D, et al.: Necrotizing fasciitis in captive juvenile Crocodylus porosus caused by Streptococcus agalactiae: an outbreak and review of the animal and human literature. Epidemiol Infect 2007, 135:1248–1255.PubMedCrossRef 7. Ip M, Cheuk ES, Tsui MH, Kong F, Leung TN, Gilbert GL: Identification of a Streptococcus agalactiae selleck serotype III subtype 4 clone in association with adult invasive disease

in Hong Kong. J Clin Microbiol 2006, 44:4252–4254.PubMedCrossRef 8. Wang YH, Su LH, Hou JN, Yang TH, Lin TY, Chu C, et al.: Group B streptococcal disease in nonpregnant patients: emergence of highly resistant strains of serotype Ib in Taiwan in 2006 to 2008. J Clin Microbiol 2010, 48:2571–2574.PubMedCrossRef 9. Jolley KA, Chan MS, Maiden MC: mlstdbNet – distributed multi-locus sequence typing (MLST) databases. BMC Bioinforma 2004, 5:86.CrossRef 10. Van Belkum A, Tassios PT, Dijkshoorn L, Haeggman S, Cookson B, Fry NK, et al.: Guidelines for the validation and application

of typing methods for use in bacterial epidemiology. Clin Microbiol Infect 2007,13(3):1–46.PubMedCrossRef 11. Sun Y, Kong F, Zhao Z, Gilbert GL: Comparison of a 3-set genotyping system with multilocus sequence typing for Streptococcus agalactiae (Group B Streptococcus). J Clin Microbiol 2005, 43:4704–4707.PubMedCrossRef 12. Spratt BG: The 2011 Garrod Lecture: From penicillin-binding proteins to molecular epidemiology. J Antimicrob Chemother 2012, 67:1578–1588.PubMedCrossRef 13. Jones N, Bohnsack JF, Takahashi S, Oliver KA, Chan MS, Kunst

F, et al.: Multilocus sequence typing system for group B streptococcus. J Clin Microbiol KPT-330 manufacturer 2003, 41:2530–2536.PubMedCrossRef 14. Brochet M, Couve E, Zouine M, Vallaeys T, Rusniok C, Lamy MC, et al.: Genomic diversity and evolution within the species Streptococcus agalactiae. Microbes Infect 2006, 8:1227–1243.PubMedCrossRef 15. Sørensen UB, Poulsen K, Ghezzo C, Margarit I, Kilian M: Emergence and global dissemination of host-specific Streptococcus agalactiae clones. mBio 2010, 1:e00178–10.PubMedCrossRef 16. Evans JJ, Bohnsack JF, Klesius PH, Whiting AA, Garcia JC, Shoemaker Phospholipase D1 CA, et al.: Phylogenetic relationships among Streptococcus agalactiae isolated from piscine, dolphin, bovine and human sources: a dolphin and piscine lineage associated with a fish epidemic in Kuwait is also associated with human neonatal infections in Japan. J Med Microbiol 2008, 57:1369–1376.PubMedCrossRef 17. Zappulli V, Mazzariol S, Cavicchioli L, Petterino C, Bargelloni L, Castagnaro M: Fatal necrotizing fasciitis and myositis in a captive common bottlenose dolphin (Tursiops truncatus) associated with Streptococcus agalactiae. J Vet Diagn Invest 2005, 17:617–622.PubMedCrossRef 18. Amborski RL, Snider TG III, Thune RL, Culley DD Jr: A non-hemolytic, group B Streptococcus infection of cultured bullfrogs, Rana catesbeiana, in Brazil. J Wildl Dis 1983, 19:180–184.PubMed 19.

Figure 6 UV–vis spectra and Kubelka-Munk function. (a) UV–vis diffuse reflectance spectra for different samples and the respective Kubelka-Munk function for estimating the band gap energy (EBG) from variation

of (αhν)1/2 with photon energy (hν) (b). Figure  7a displays the degradation efficiency of MB versus irradiation time over different samples. A blank study (absence of catalyst) was carried out as a background check. For a comparison, P25 was investigated under the same conditions. It could be observed that without catalysts, only 21% of MB was degraded within 60 min. In contrast, Fosbretabulin purchase the degradation efficiency of MB enhanced greatly in the presence of catalysts. The photocatalytic activity of the N-doped mesoporous TiO2 nanorods was much higher than that of the C-N co-doped rod-like TiO2 photocatalyst in our previous work Selleckchem Salubrinal [11]. The best catalytic efficiency was found in the sample

NMTNR-6-500, which takes 60 min to degrade 99.8% MB in the solution, while the P25 degraded only 54% MB in the solution during the same time. Figure  7b shows a linear relationship between ln(C 0/C) and the reaction time, indicating that the photodegradation of MB follows the first-order kinetics. The order of rate constants was summarized as follows: blank < P25 < NMTNR-4-600 < NMTNR-4-400 < NMTNR-2-500 < NMTNR-4-500 < NMTNR-6-500, which is consistent with the conclusions of photocatalytic degradation curves presented in Figure  7a. Figure 7 Degradation curves of MB and plot of ln( C 0 / C ). (a) The degradation curves of MB under visible light irradiation. (b) The plot of ln(C 0/C) with irradiation time of visible light for different samples. Based on the data in Table  1, the excellent photocatalytic performance of N-doped mesoporous TiO2 nanorods might be explained by the following factors. Firstly, N doping could extend the spectral response to visible light and greatly improve the utilization of visible light [1, 20]. Secondly, it is known that mesoporosity can improve surface adsorption capacity of the reactants due to the increased surface area [21, 22].

It is obvious that with the increase of N proportion, the photocatalytic efficiency was improved. This may be resulting from the narrowed band gap and the enlarged surface to area of N-doped mesoporous TiO2 nanorods. In addition, the calcination temperature also plays an important role in the catalytic efficiency. On the one hand, with the increase of the temperature, the grain size and band gap increased and the specific surface area decreased, which are responsible for the depress of photocatalytic activity. On the other hand, under lower temperature, TiO2 had a lower crystallinity, which results in the lower photocatalytic activity. To evaluate the stability of these photocatalysts, the repeated experiments for the degradation of MB were performed, and the results were shown in Figure  8.