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Exopolysaccharides (EPSs) are important bioactive carbohydrate compound such as Capsular polysaccharide (CPS). EPSs are often used as bioenrichment agents and bioabsorbers to remove environmental pollutants like di-n-butyl phthalate (DBP). Among the EPSs producing bacteria, lactic acid bacteria (LAB) have gained the most attention. As generally recognized as safe (GRAS) microorganisms, LAB can produce EPSs with many different structures without any health risks. However, the EPSs production of LAB is usually not enough for large-scale application in industrial production. Here, capA gene (encoding CPS biosynthesis protein) was overexpressed in Lactobacillus plantarum P1 to improve the production of EPSs and further enhance the capability of the adsorption of DBP. Compared with P1, the CPS production in capA overexpressed strain was increased by 11.3 mg/L, and the EPSs thickness was increased from 0.0786±0.0224μm in P1 to 0.1160±0.0480μm in P1-capA. These caused the adsorption ratio of DBP in P1-capA to be doubled. Overall, the findings in this study provided a safe solution for the adsorption and removing of DBP.

Tuberculosis, caused by mycobacteria, continues to pose a substantial public health threat. Mycobacteria typically use cholesterol from the membranes of host macrophages as a carbon and energy source. Most genes that control cholesterol degradation are regulated by KstR, which is highly conserved in Mycobacterium tuberculosis and Mycobacterium smegmatis. Through bioinformatic analysis, we found a typical global nitrogen regulator (GlnR)-binding motif (CCGAC-AACAGT-GACAC) in the promoter region of kstR of M. smegmatis, and we determined its binding activity in vitro using electrophoretic mobility shift assays. Using RT-qPCR, we found that nine genes involved in side-chain or sterol-ring oxidation were upregulated in a ΔglnR M. smegmatis strain compared to the WT strain and glnR-complemented strains under nitrogen limitation. ATP assays in macrophages revealed that coordinated GlnR-KstR regulation significantly reduced the viability of M. smegmatis in macrophages. Thus, we found that various genes involved in cholesterol catabolism are regualted by GlnR via KstR in response to environmental nitrogen, and that they further affect the invasive ability of M. smegmatis. These findings revealed a novel regulatory mechanism of cholesterol catabolism, which may be useful in the development of new strategies for controlling tuberculosis. This article is protected by copyright. All rights reserved.

This study explored the molecular mechanism behind the protective effects from low-dose lipopolysaccharide (LPS) on an in-vitro model of spinal cord injury (SCI). For this, PC12 cells were treated with different concentrations of LPS and the cell counting kit-8 assay was used to measure the toxicity of LPS to the cells. Next, we used immunofluorescence to measure nuclear translocation of Nrf2 in PC12 cells. PC12 cells were then treated with IGF-1 (PI3K agonist) and LY294002 (PI3K inhibitor). An in-vitro model of SCI was then established via oxygen–glucose deprivation/reoxygenation. Rates of apoptosis were measured using flow cytometry and the TUNEL assay. Low-dose LPS increased the expression levels of Nrf2, p-PI3K/PI3K, and p-AKT/AKT, and facilitated nuclear translocation of Nrf2. The activation of PI3K–AKT signaling by IGF-1 significantly increased the expression of Nrf2, whereas inhibition of PI3K–AKT signaling significantly decreased the expression of Nrf2. Low-dose LPS reduced the apoptotic ratio of PC12 cells, decreased the expression levels of caspase 3 and caspase 9, and increased the expression levels of HO-1, NQO1, and γ-GCS. Low-dose LPS also reduced the rate of apoptosis and oxidative stress by activating the PI3K–AKT–Nrf2 signaling pathway. Collectively, the results indicate that PI3K–AKT–Nrf2 signaling participates in the protective effects from low-dose LPS in an in-vitro PC12 cell model of SCI.

Melanoma is the most aggressive skin cancer, and accounts for the major part of skin cancer-related deaths in the world. In addition, the underlying mechanism of tumor progression in melanoma remains far from being elucidated. In this study, we have evaluated the function of miR-25 in melanoma. First, we examined the expression of miR-25 in four melanoma cell lines (A875, MV3, M14 and uacc-257) and in a normal melanocyte cell line (HEM-a). Then, we overexpressed miR-25 in M14 cells. Our results show that miR-25 promotes M14 cell proliferation and migration. We found that miR-25 up-regulates the PI3K/Akt/mTOR signaling pathway in these tumor cells. Furthermore, a luciferase-based reporter gene assay showed that miR-25 could directly target the RNA-binding motif protein 47 (RBM47). Taken together, our findings suggest that RBM47 is a promising target for the treatment of melanoma.

Malignant melanoma, one of the most aggressive skin cancers, has a very high mortality rate. Currently, the number of drugs to treat melanoma is low. Although new immunotherapeutic approaches based on the use of antibodies against immune checkpoints have shown long term responses, it is urgent to develop novel anti-melanoma drugs with a high efficiency and a low toxicity in a large number of patients. Lycorine, a natural product, has been reported to exert antitumor effects on some cancers. However, the impact of lycorine on melanoma cells is still unknown. Using the CCK8 assay, we found that lycorine can suppress the proliferation of melanoma A375 cells in a dose-time-dependent manner. Moreover, a transwell assay showed that lycorine inhibited the migration and invasion of A375 cells significantly. Further, lycorine treatment could induce the apoptosis of the A375 cells. Biochemical analyses showed that the expression level of the anti-apoptosis Bcl-2 protein decreased, while the expression of the pro-apoptosis protein Bax and active caspase-3 increased after lycorine treatment. Finally, using western blot assay, we found that the antitumor effects of lycorine on A375 cells might be through the inactivation of the PI3K/Akt signaling pathway. Based on these observations, we suggest that lycorine may be an interesting candidate for further studies on its ability to represent a novel antitumor drug for human melanoma treatment in the future.

Mycobacterium tuberculosis utilizes fatty acids of the host as the carbon source. Metabolism of odd-chain fatty acids by Mycobacterium tuberculosis produces propionyl coenzyme A (propionyl-CoA). The methylcitrate cycle is essential for mycobacteria to utilize the propionyl-CoA to persist and grow on these fatty acids. In M. smegmatis, methylcitrate synthase, methylcitrate dehydratase, and methylisocitrate lyase involved in the methylcitrate cycle are encoded by prpC, prpD, and prpB, respectively, in operon prpDBC. In this study, we found that the nitrogen regulator GlnR directly binds to the promoter region of the prpDBC operon and inhibits its transcription. The binding motif of GlnR was identified by bioinformatic analysis and validated using DNase I footprinting and electrophoretic mobility shift assays. The GlnR-binding motif is separated by a 164-bp sequence from the binding site of PrpR, a pathway-specific transcriptional activator of methylcitrate cycle, but the binding affinity of GlnR to prpDBC is much stronger than that of PrpR. Deletion of glnR resulted in faster growth in propionate or cholesterol medium compared with the wild-type strain. The ΔglnR mutant strain also showed a higher survival rate in macrophages. These results illustrated that the nitrogen regulator GlnR regulates the methylcitrate cycle through direct repression of the transcription of the prpDBC operon. This finding not only suggests an unprecedented link between nitrogen metabolism and the methylcitrate pathway but also reveals a potential target for controlling the growth of pathogenic mycobacteria. IMPORTANCE The success of mycobacteria survival in macrophage depends on its ability to assimilate fatty acids and cholesterol from the host. The cholesterol and fatty acids are catabolized via β-oxidation to generate propionyl coenzyme A (propionyl-CoA), which is then primarily metabolized via the methylcitrate cycle. Here, we found a typical GlnR binding box in the prp operon, and the affinity is much stronger than that of PrpR, a transcriptional activator of methylcitrate cycle. Furthermore, GlnR repressed the transcription of the prp operon. Deletion of glnR significantly enhanced the growth of Mycobacterium tuberculosis in propionate or cholesterol medium, as well as viability in macrophages. These findings provide new insights into the regulatory mechanisms underlying the cross talk of nitrogen and carbon metabolisms in mycobacteria.

Mycobacterium tuberculosis utilizes fatty acids of the host as the carbon source. Metabolism of odd-chain fatty acids by Mycobacterium tuberculosis produces propionyl coenzyme A (propionyl-CoA). The methylcitrate cycle is essential for mycobacteria to utilize the propionyl-CoA to persist and grow on these fatty acids. In M. smegmatis, methylcitrate synthase, methylcitrate dehydratase, and methylisocitrate lyase involved in the methylcitrate cycle are encoded by prpC, prpD, and prpB, respectively, in operon prpDBC. In this study, we found that the nitrogen regulator GlnR directly binds to the promoter region of the prpDBC operon and inhibits its transcription. The binding motif of GlnR was identified by bioinformatic analysis and validated using DNase I footprinting and electrophoretic mobility shift assays. The GlnR-binding motif is separated by a 164-bp sequence from the binding site of PrpR, a pathway-specific transcriptional activator of methylcitrate cycle, but the binding affinity of GlnR to prpDBC is much stronger than that of PrpR. Deletion of glnR resulted in faster growth in propionate or cholesterol medium compared with the wild-type strain. The ΔglnR mutant strain also showed a higher survival rate in macrophages. These results illustrated that the nitrogen regulator GlnR regulates the methylcitrate cycle through direct repression of the transcription of the prpDBC operon. This finding not only suggests an unprecedented link between nitrogen metabolism and the methylcitrate pathway but also reveals a potential target for controlling the growth of pathogenic mycobacteria. IMPORTANCE The success of mycobacteria survival in macrophage depends on its ability to assimilate fatty acids and cholesterol from the host. The cholesterol and fatty acids are catabolized via β-oxidation to generate propionyl coenzyme A (propionyl-CoA), which is then primarily metabolized via the methylcitrate cycle. Here, we found a typical GlnR binding box in the prp operon, and the affinity is much stronger than that of PrpR, a transcriptional activator of methylcitrate cycle. Furthermore, GlnR repressed the transcription of the prp operon. Deletion of glnR significantly enhanced the growth of Mycobacterium tuberculosis in propionate or cholesterol medium, as well as viability in macrophages. These findings provide new insights into the regulatory mechanisms underlying the cross talk of nitrogen and carbon metabolisms in mycobacteria.

NADP + is a vital cofactor involved in a wide variety of activities, such as redox potential and cell death. Here, we show that NADP + negatively regulates an acetyltransferase from Myxococcus xanthus , Mxan_3215 ( Mx Kat), at physiologic concentrations. Mx Kat possesses an NAD(P)-binding domain fused to the Gcn5-type N -acetyltransferase (GNAT) domain. We used isothermal titration calorimetry (ITC) and a coupled enzyme assay to show that NADP + bound to Mx Kat and that the binding had strong effects on enzyme activity. The Gly11 residue of Mx Kat was confirmed to play an important role in NADP + binding using site-directed mutagenesis and circular dichroism spectrometry. In addition, using mass spectrometry, site-directed mutagenesis, and a coupling enzymatic assay, we demonstrated that Mx Kat acetylates acetyl coenzyme A (acetyl-CoA) synthetase (Mxan_2570) at Lys622 in response to changes in NADP + concentration. Collectively, our results uncovered a mechanism of protein acetyltransferase regulation by the coenzyme NADP + at physiological concentrations, suggesting a novel signaling pathway for the regulation of cellular protein acetylation. IMPORTANCE Microorganisms have developed various protein posttranslational modifications (PTMs), which enable cells to respond quickly to changes in the intracellular and extracellular milieus. This work provides the first biochemical characterization of a protein acetyltransferase ( Mx Kat) that contains a fusion between a GNAT domain and NADP + -binding domain with Rossmann folds, and it demonstrates a novel signaling pathway for regulating cellular protein acetylation in M. xanthus . We found that NADP + specifically binds to the Rossmann fold of Mx Kat and negatively regulates its acetyltransferase activity. This finding provides novel insight for connecting cellular metabolic status (NADP + metabolism) with levels of protein acetylation, and it extends our understanding of the regulatory mechanisms underlying PTMs.

The regulatory mechanisms underlying the uptake and utilization of multiple types of carbohydrates in actinomycetes remain poorly understood. In this study, we show that GlnR (central regulator of nitrogen metabolism) serves as a universal regulator of nitrogen metabolism and plays an important, previously unknown role in controlling the transport of non-phosphotransferase-system (PTS) carbon sources in actinomycetes. It was observed that GlnR can directly interact with the promoters of most (13 of 20) carbohydrate ATP-binding cassette (ABC) transporter loci and can activate the transcription of these genes in response to nitrogen availability in industrial, erythromycin-producing Saccharopolyspora erythraea. Deletion of the glnR gene resulted in severe growth retardation under the culture conditions used, with select ABC-transported carbohydrates (maltose, sorbitol, mannitol, cellobiose, trehalose, or mannose) used as the sole carbon source. Furthermore, we found that GlnR-mediated regulation of carbohydrate transport was highly conserved in actinomycetes. These results demonstrate that GlnR serves a role beyond nitrogen metabolism, mediating critical functions in carbon metabolism and crosstalk of nitrogen- and carbon-metabolism pathways in response to the nutritional states of cells. These findings provide insights into the molecular regulation of transport and metabolism of non-PTS carbohydrates and reveal potential applications for the cofermentation of biomass-derived sugars in the production of biofuels and bio-based chemicals.

Mycobacterium tuberculosisutilizes the fatty acids of the host as the carbon source. While the metabolism of odd chain fatty acids produces propionyl-CoA. Methylcitrate cycle is essential for Mycobacteria to utilize the propionyl-CoA to persist and grow on these fatty acids. InM. smegmatis, methylcitrate synthase, methylcitrate dehydratase, and methylisocitrate lyase involved in methylcitrate cycle were respectively encoded byprpC,prpD,and prpBin operonprpDBC. In this study, we found that the nitrogen regulator GlnR directly binds to the promoter region ofprpDBCoperon and inhibits its transcription. The typical binding sequence of GlnR was identified by bioinformatics analysis and electrophoretic mobility shift assay. The GlnR-binding motif was seperated by 164 bp with the binding site of PrpR which was a pathway-specific transcriptional activator of methylcitrate cycle. Moreover, the affinity constant of GlnR was much stronger than that of PrpR toprpDBC. The deletion ofglnRresulted in poor growth in propionate or cholesterol medium comparing with wild-type strain. The ΔglnRmutant strain also showed a higher survival in macrophages. These results illustrated that the nitrogen regulator GlnR regulated methylcitrate cycle through directly repressing the transcription ofprpDBCoperon. The finding reveals an unprecedented link between nitrogen metabolism and methylcitrate pathway, and provides a potential application for controlling populations of pathogenic mycobacteria.Author SummaryNutrients are crucial for the survival and pathogenicity ofMycobacterium tuberculosis. The success of this pathogen survival in macrophage due to its ability to assimilate fatty acids and cholesterol from host. The cholesterol and fatty acids are catabolized via β-oxidation to generate propionyl-CoA, which is then mainly metabolized via the methylcitrate cycle. The assimilation of propionyl-CoA needs to be tightly regulated to prevent its accumulation and alleviate toxicity in cell. Here, we identified a new regulator GlnR (the nitrogen transcriptional regulator) that repressed the transcription ofprpoperon involved in methylcitrate cycle inM. smegmatis. In this study, we found a typical GlnR binding box inprpoperon, and the affinity is much stronger than that of PrpR which is known as a pathway-specific transcriptional activator of methylcitrate cycle. In addition, deletion ofglnRobviously affect the growth of mutant in propionate or cholesterol medium, and show a better viability in macrophage. The findings not only provide the insights into the regulatory mechanism underlying crosstalk of nitrogen metabolism and carbon metabolism, but also reveal a potential application for controlling populations of pathogenic mycobacteria.

AccD6 is an important component of acetyl-CoA/propionyl-CoA carboxylase, which acts as a key role in mycolic acid synthesis and short chain fatty acyl-coenzyme A metabolism. In this study, we demonstrated that AccD6 of Mycobacterium smegmatis associates with AccA3 (α subunit of acetyl-CoA carboxylase, MSMEG_1807) and AccE (e subunit, MSMEG_1812) to form the acetyl-CoA (propionyl-CoA) carboxylase. Results showed that the MSMEG_4331 subunit is a regulator that interacts with the promoter region of accD6 to inhibit its transcription. Transcription of accD6 was reduced by 50% in the mutant M. smegmatis strain overexpressing MSMEG_4331. Moreover, the activity of AccD6 was inhibited by acylation (such as acetylation and propionylation). These results demonstrate that AccD6 of M. smegmatis is regulated at both the transcriptional and post-translational levels. Our findings highlight the novel regulatory mechanism underlying mycolic acid biosynthesis in mycobacteria.

Two genes encoding β-glucosidase from Streptomyces coelicolor A3(2) were cloned and expressed in Escherichia coli BL21 (DE3). Two recombinant enzymes (SC1059 and SC7558) were purified and characterized. The molecular mass of the purified SC1059 and SC7558 as determined by SDS-PAGE agrees with the calculated values (51.0 and 52.2 kDa, respectively). Optimal temperature and pH for the two enzymes were both at 35 °C and 6.0. SC7558 exhibited to be much more active than SC1059 under optimal conditions, and it was recombined with ice nucleation protein which could anchor on the surface of the cell. The optimal temperature and pH of the recombinant cells were 55 °C and 8.0, respectively. The resultant cells were to be used as material for immobilized β-glucosidase, which is convenient to catalyze substrates in various complicated conditions.

Oral lichen planus (OLP) is a chronic inflammatory disease, has prolonged courses, repeated attacks and resistance to treatment. The traditional narrow spectrum UVB treatment has an established efficacy on skin lichen planus, and high safety. However, most of ultraviolet phototherapy devices have a huge volume, thereby cannot be used in the treatment of OLP. Lymphocytic infiltration is evident in the lesions of lichen planus, and the direct irradiation of 308-nm excimer laser can induce apoptosis of the T lymphocytes in skin lesions, thereby has a unique therapeutic effect on the diseases involving T lymphocytes. This study aims to investigate the efficacy of 308-nm excimer laser in the treatment of OLP. A total of six OLP patients were enrolled into this study, and further pathological diagnosis was conducted, then 308-nm excimer laser was used in the treatment. The efficacy of 308-nm excimer laser in the treatment of OLP was satisfactory. The clinical symptoms of five patients were significantly improved. In two patients, the erosion surface based on congestion and the surrounding white spots completely disappeared, and clinical recovery was achieved. Three patients achieved partial remission, that is, the erosion surface healed, congestion and white spot area shrunk by more than 1/2 of the primary skin lesions. In the remaining one patient, the erosion surface had not completely healed after treatment, and congestion and white spot area shrunk by less than 1/2 of the primary skin lesions. Only one patients had developed mild pain during the treatment, and this symptom alleviated by itself. The 308-nm excimer laser therapy can serve as a safe and effective treatment for OLP.

Four new metal complexes {[Cu(api)2(H2O)]·(ClO4)2·CH3CN}n (1), [Cu(api)2(ClO4)2]n (2), [Cd(api)2(SCN)2]n (3) and [Ni(api)2(SCN)2]n (4) (api = 1-(3-Aminopropyl)-imidazole) were synthesized by reactions of api and different metal salts under different conditions. Interestingly, complexes 1–3 exhibit various one dimensional (1D) double chain structures, while complex 4 shows a 2D layer structure. The results indicate that metal ions, anions, solvents, and the synthesis methods, have great influence on the formation and structure of the complexes.

This paper studies the continuous prisoner's dilemma games (CPDG) on Barabasi—Albert (BA) networks. In the model, each agent on a vertex of the networks makes an investment and interacts with all of his neighboring agents. Making an investment is costly, but which benefits its neighboring agents, where benefit and cost depend on the level of investment made. The payoff of each agent is given by the sum of payoffs it receives in its interactions with all its neighbors. Not only payoff, individual's guilty emotion in the games has also been considered. The negative guilty emotion produced in comparing with its neighbors can reduce the utility of individuals directly. We assume that the reduction amount depends on the individual's degree and a baseline level parameter. The group's cooperative level is characterized by the average investment of the population. Each player makes his investment in the next step based on a convex combination of the investment of his best neighbors in the last step, his best history strategies in the latest steps which number is controlled by a memory length parameter, and a uniformly distributed random number. Simulation results show that this degree-dependent guilt mechanism can promote the evolution of cooperation dramatically comparing with degree-independent guilt or no guilt cases. Imitation, memory, uncertainty coefficients and network structure also play determinant roles in the cooperation level of the population. All our results may shed some new light on studying the evolution of cooperation based on network reciprocity mechanisms.

Four new copper(II) complexes [Cu(HL)(im)](ClO4)2 (1), [Cu(HL)(py)](ClO4)2 (2), [Cu2(HL)2(bpy)2](ClO4)4·H2O (3), and [Cu2(HL)2(bpy)](ClO4)4·H2O (4) (im = imidazole; py = pyridine; bpy = 4,4′-bipyridine) were synthesized by reactions of tripodal ligandN1-(2-aminoethyl)-N1-(1H-imidazol-4-ylmethyl)-ethane-1,2-diamine(HL) and Cu(ClO4)2·6H2O with different nitrogen-containing aromatic ligands. It was found that the size of the N-containing aromatic ligand, and the ratio of the ligand and metal ion, have great influence on the formation and structure of the complexes.

In this paper, the fluid solid coupling method is used and the FE (Finite Element) analysis is conducted for the PSSS (Periodic Symmetric Struts Support) of the large scale GT(Gas Turbine), and the overall thermal stress and thermal deformation are obtained. From the structure feature of the gas turbine, the initial boundary conditions of the high-temperature gas flow field and thermal deformation are analyzed at first. Then the coupling relationship between fluid and solid two phases is expressed mathematically, and the thermal conductivity is considered for calculation of heat transfer process, and the overall temperature field is obtained. Finally the thermal boundary condition of PSSS is defined and the structural FE analysis is conducted. At the same time, the thermal stress field and thermal deformation field are discussed for overall PSSS structure.

In this paper，the simplified three-dimensional model of Periodic Symmetric Struts Support (PSSS) was established, which is applied to a certain type of gas turbine. The software of computational fluid Dynamics (CFD) and the standard k-ε turbulence model are used in the numerical simulation．To simulate the coupling problems of fluid and solid，the numerical models by considering the heat transfer problem coupling with the solid and fluid have been developed．The internal flow field in PSSS was numerically simulated by an effective method for solving integrated coupling problems. The temperature field and thermal deformation rule of the PSSS was obtained. Through comparison coordinate values of the checked points before and after thermal deformation, the impact of thermal deformation on bearing center level height under temperature load was studied. The centering process of the PSSS at high temperature state was verified.

Meshing for finite element analysis accuracy plays a very important part in numerical simulation of Periodic Symmetric Struts Support (PSSS). Different accuracy can be obtained by different element sizes or types. Three element types and eight element sizes are used for comparing the accuracy of modal analysis in this paper. Comparing with the mutual relations of different accuracy, the scientific basis is provided for selecting the correct mesh size and improves the efficiency of numerical calculation in modal analysis.

In this paper, in order to overcome the technical difficulty of center level height of Periodic Symmetric Struts Support (PSSS) by using the test in the field and reduce the high cost of testing, the method of the finite element analysis by considering thermal condition and the dynamic response is used and the center level height of PSSS is evaluated. Some relations for center level height changing process of PSSS were found and some parametric effects are obtained for the stability analysis of gas turbine by changing the number of struts support and angle.

In evolutionary games, it becomes more difficult to choose optimal strategies for players because of incomplete information and bounded rationality. For bounded rational players, how to maximize the expected sum of payoffs by learning and changing strategies is an important question in evolutionary game theory. Reinforcement learning does not need a model of its environment and can be used online, it is well-suited for problems with incomplete and uncertain information. Evolutionary game theory is the subject about the decision problems of multiagent with incomplete information. In this article, reinforcement learning is introduced in evolutionary games, multiagent reinforcement learning model is constructed, and the learning algorithm is presented based on Q -learning. The results of simulation experiments show that the multiagent reinforcement learning model can be applied successfully in evolutionary games for finding the optimal strategies.

Saccharopolyspora erythraea is a Gram-positive bacterium that can produce antibiotics. However, this microorganism must often be genetically improved for higher production before it can be used in an industrial setting. Here, we report the whole-genome sequence of the industrial hyperproducer strong mutator Saccharopolyspora erythraea strain D.

A mechanistic proposal for this novel transformation involving both C—O bond formation and C—C bond cleavage is given.

Saccharopolyspora erythraea produces a large number of secondary metabolites with biological activities, including erythromycin. Elucidation of the mechanisms through which the production of these secondary metabolites is regulated may help to identify new strategies for improved biosynthesis of erythromycin. In this paper, we describe the systematic prediction and analysis of small non-coding RNAs (sRNAs) in S. erythraea, with the aim to elucidate sRNA-mediated regulation of secondary metabolite biosynthesis. In silico and deep-sequencing technologies were applied to predict sRNAs in S. erythraea. Six hundred and forty-seven potential sRNA loci were identified, of which 382 cis-encoded antisense RNA are complementary to protein-coding regions and 265 predicted transcripts are located in intergenic regions. Six candidate sRNAs (sernc292, sernc293, sernc350, sernc351, sernc361, and sernc389) belong to four gene clusters (tpc3, pke, pks6, and nrps5) that are involved in secondary metabolite biosynthesis. Deep-sequencing data showed that the expression of all sRNAs in the strain HL3168 E3 (E3) was higher than that in NRRL23338 (M), except for sernc292 and sernc361 expression. The relative expression of six sRNAs in strain M and E3 were validated by qRT-PCR at three different time points (24, 48, and 72 h). The results showed that, at each time point, the transcription levels of sernc293, sernc350, sernc351, and sernc389 were higher in E3 than in M, with the largest difference observed at 72 h, whereas no signals for sernc292 and sernc361 were detected. sernc293, sernc350, sernc351, and sernc389 probably regulate iron transport, terpene metabolism, geosmin synthesis, and polyketide biosynthesis, respectively. The major significance of this study is the successful prediction and identification of sRNAs in genomic regions close to the secondary metabolism-related genes in S. erythraea. A better understanding of the sRNA-target interaction would help to elucidate the complete range of functions of sRNAs in S. erythraea, including sRNA-mediated regulation of erythromycin biosynthesis.

This paper studies the decision behavior of workers and characteristics of retirement age in social security system. Based on overlapping-generation model and Markov decision process, this paper constructs a dynamic decision model for social security system. In this model, workers choose their optimal retirement age taking into account the current social security system. In addition, this paper analyzes the equilibrium results. In the end, experiment simulation shows that social security system has some effects on the retirement behavior of workers.

Five hundred fifty samples were collected from five chicken farms in Shanghai during March 2005 to October 2006. Twenty-five samples tested positive for Salmonella from a total of 550 samples, of which 500 were obtained from feces of healthy chickens and 50 were obtained from diseased chicks. The 25 presumptive Salmonella isolates were confirmed by the API 20E identification kit. Serotyping of these isolates by agglutination tests with antiserum displayed seven serovars; genotyping of these isolates with multilocus sequence typing demonstrated six sequence type (ST) patterns (i.e., ST-11, ST-19, ST-92, ST-96, ST-290, and ST-367). The multilocus sequence typing data revealed that some of these strains, isolated from different farms, might have the same ST and might come from the same source. The susceptibilities of these strains to 14 antimicrobials were determined; most of the isolates (13 of 25) were resistant to doxycycline and tetracycline, and two isolates were resistant to cefotaxime and ceftazidime, but none was resistant to gentamicin or kanamycin.

This paper proposes a multi-agent decision model based on recurrent neural networks and particle swarm optimization technology. In this paper, the recurrent neural network is used for strategy decision controller. The inputs of the recurrent neural network are decided by the last strategies of other agents. Then the outputs determine the next strategy that the agent will choose. The weight values are updated by particle swarm optimization algorithm. The multi-agent decision model is applied in public goods games, and numerical results show that this decision model has the ability of adaptive learning and can prevent the collision between agents to realize the total social utility maximum.

Various substituted N-aryl carbamoyl methyl diacetates have been synthesized from N-aryl-3-oxobutanamides via a diacetoxylation mediated by the combination of iodobenzene diacetate (PIDA)/Zn(OAc)2. This provides a new convenient method to form C–O bonds and cleave C–C bonds. Ten examples were obtained from easily available materials in good to excellent yields.