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Based on the 1961-2007 meteorological data of Haikou City and its urbanization level in 1989-2007, this paper studied the climatope change and its relations with city development of the City. In 1995-2007, the mean annual air temperature in Haikou had an obvious increase, with an increment of 0-93 °C·a-1, while the mean annual relative humidity decreased obviously, with a decrement of 3% per year, compared with those in 1961-1990. Both the mean annual air temperature and the mean annual relative humidity had significant correlations with the urbanization level of Haikou, suggesting that urbanization could better explain the recent 20 years variation of climate elements in Haikou. The city development of Haikou not only changed the climatope elements, but also affected the air quality, making the frequency of acid rain increased, and the mean annual acid rain pH value decreased. [ABSTRACT FROM AUTHOR]

This paper presents a dynamics modeling and control scheme for multi-spacecraft coordinated flying based on dynamical decomposition. With certain decomposition arithmetics, physically separated spacecrafts can be connected together, and multi-spacecraft coordinated flying involved in complicated motions can be decomposed into two parts, one is the group motion of multi-spacecraft flying and the other is the relative motion of spacecrafts, formation flying. The dynamics models of these two subsystems possess the similar form with that of a single spacecraft, and the formation maintenance, reconfiguration and formation transfer within a large scope can be realized by controlling one of the subsystems. Tracking control laws for group system and formation system are also designed, and their stability is proved by Lyapunov theorem. Simulation results validate the effectiveness of the decomposition arithmetics and the control scheme. [ABSTRACT FROM AUTHOR]

This study deals with grid-connected multi-microgrid system (MMGS) operation scheduling optimization problem using improved marine predators algorithm. Studies are lacking a system operation strategy designed to involve the internal power interaction and load demand response in the scheduling manipulation is short. This study involves power interaction and demand response to achieve the MMGS operational economy and reliability. Each MGS is combined to main grid with the continuous use of renewable energy and MMGS rapid development. This study proposes the analytical steps as follows. (1) the MMGS construction model includes wind energy and photovoltaic; (2) the optimization objective function so as to minimize the cost is constructed according to the characteristics of the equipment in the system; (3) a hierarchical improved marine predators algorithm is assumed to boost the optimal effect; (4) the test of the enhanced algorithm is completed and the optimization problem of the total running cost is solved; and; (5) a system operation strategy is designed considering the internal power interaction and load demand response in the MMGS scheduling operation. A different algorithms comparative analysis is performed. The proposed scheduling optimization approach is testified among analysis of specific examples, and the total operating cost is reduced by 11.19%. • This study deals with grid-connected MMGS operation scheduling optimization problem using HIMPA. • Prior studies are lacking a system operation strategy to involve the internal power interaction. • A system operation strategy is involved the internal power interaction and load demand response in the MMGS scheduling operation. • The proposed approach is testified among specific examples and the total cost is reduced by 11.19%. [ABSTRACT FROM AUTHOR]

Cathepsin L (CatL) has been widely known for its involvement in the innate immunity. However, it still remains poorly understand how CatL modulates the immune system of teleosts. Moreover, the CatL of Nile tilapia (NtCatL) has not been cloned or characterized. In this study, the gene encoding NtCatL was cloned, and was characterized by bioinformatics analysis, heterologous expression and protease activity assay. The coding sequence of NtCatL is 1017 bp in length and encodes 338 amino acid residues with a predicted molecular weight of 38.487 kDa and a theoretical isoelectric point of 5.79. NtCatL possesses the features of a typical cathepsin L, including one signal peptide, one propeptide region, and one papain family cysteine protease domain containing four active site residues (Gln 135 , Cys 141 , His 281 , and Asn 305 ). The prediction of protein-protein interaction shows that NtCatL may interact with some functional proteins for realizing an immune function. Real-time quantitative PCR revealed the widespread transcriptional expression of NtCatL in six tissues of healthy Nile tilapia, and the NtCatL mRNA is significantly up-regulated after Streptococcus agalactiae challenge. These results suggest that NtCatL is likely to be involved in the immune reaction of Nile tilapia. Recombinant proteins from the mature domain (residues 117-337) of NtCatL were obtained by heterologous expression using pET28a and Rosetta (DE3) competent cells. A protein product with the high purity was obtained by using TALON Superflow purification rather than adopting HisTrap HP columns. The protease activity of the recombinant protein was verified by using a substrate hydrolyzing assay. This work has cloned and characterized the CatL from Nile tilapia for the first time, and contributes to elucidating the immunological functions of CatL., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The vertical distributions of methane-oxidizing bacteria (MOBs) and sulfate-reducing bacteria (SRBs) in the marine sediment core of DH-CL14 from the Dongsha region, the South China Sea, were investigated. To enumerate MOBs and SRBs, their specific genes of pmoA and apsA were quantified by a culture-independent molecular biological technique, real-time polymerase chain reaction (RT-PCR). The result shows that the pmoA gene copies per gram of sediments reached the maximum of 1,118,679 at the depth of 140-160 cm. Overall considering the detection precision, sample amount, measurement cost, and sensitivity to the seepage of methane from the oil/gas reservoirs or gas hydrates, we suggest that the depth of 140-160 cm may be the optimal sampling position for the marine microbial exploration of oils, gases, and gas hydrates in the Dongsha region. The data of the pmoA and apsA gene copies exhibit an evident coupling relation between MOBs and SRBs as illustrated in their vertical distributions in this sediment core, which may well be interpreted by a high sulfate concentration inhibiting methane production and further leading to the reduction of MOBs. In comparison with the numbers of the pmoA and apsA copies at the same sediment depth, we find out that there were two methane-oxidizing mechanisms of aerobic and anaerobic oxidation in this sediment core, i.e., the aerobic oxidation with free oxygen dominantly occurred above the depth of 210-230 cm, while the anaerobic oxidation with the other electron acceptors such as sulfates and manganese-iron oxides happened below the depth of 210-230 cm.

Microorganisms play an important role in the biodegradation of petroleum contaminants, which have attracted great concern due to their persistent toxicity and difficult biodegradation. In this paper, a novel hydrocarbon-degrading bacterium HZ01 was isolated from the crude oil-contaminated seawater at the Daya Bay, South China Sea, and identified as Achromobacter sp. Under the conditions of pH 7.0, NaCl 3% (w/v), temperature 28 °C and rotary speed 150 rpm, its degradability of the total n-alkanes reached up to 96.6% after 10 days of incubation for the evaporated diesel oil. Furthermore, Achromobacter sp. HZ01 could effectively utilize polycyclic aromatic hydrocarbons (PAHs) as its sole carbon source, and could remove anthracene, phenanthrene and pyrence about 29.8%, 50.6% and 38.4% respectively after 30 days of incubation. Therefore, Achromobacter sp. HZ01 may employed as an excellent degrader to develop one cost-effective and eco-friendly method for the bioremediation of marine environments polluted by crude oil., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The biodetoxification of cyanide-rich wastewater has become increasingly popular because of its cost-effectiveness and environmental friendliness. Therefore, we have developed an effective method, optimised by response surface methodology, for detoxifying cyanide-rich wastewater using Bacillus sp. CN-22, which was newly isolated from a cyanide-contaminated electroplating sludge and could tolerate a CN⁻ concentration of 700 mg L⁻¹. The concentration of CN⁻ in the treated wastewater decreased from 200 to 6.62 mg L⁻¹ after cultivation with 2.38 % inocula for 72 h on the medium, consisting of 0.05 % KH₂PO₄, 0.15 % K₂HPO₄, 1.0 mM MgCl₂, 1.0 mM FeCl₃, 0.1 % NH₄Cl, and 0.1 % glycerol. The CN⁻ degradability of 96.69 % is similar to the predicted value of 96.82 %. The optimal cultivation conditions were controlled as follows: initial pH, 10.3; temperature, 31 °C; and rotary speed, 193 rpm. The maintenance of higher pH in the overall treatment procedures may avoid the production of volatile HCN and the risk associated with cyanide detoxification. Additionally, the bacterial strain Bacillus sp. CN-22, with its potent cyanide-degrading activity at the initial CN⁻ concentration of 200 mg L⁻¹, may be employed to effectively treat cyanide-rich wastewater, especially electroplating effluent.

The ketocarotenoid astaxanthin can be found in the microalgae Haematococcus pluvialis, Chlorella zofingiensis, and Chlorococcum sp., and the red yeast Phaffia rhodozyma. The microalga H. pluvialis has the highest capacity to accumulate astaxanthin up to 4-5% of cell dry weight. Astaxanthin has been attributed with extraordinary potential for protecting the organism against a wide range of diseases, and has considerable potential and promising applications in human health. Numerous studies have shown that astaxanthin has potential health-promoting effects in the prevention and treatment of various diseases, such as cancers, chronic inflammatory diseases, metabolic syndrome, diabetes, diabetic nephropathy, cardiovascular diseases, gastrointestinal diseases, liver diseases, neurodegenerative diseases, eye diseases, skin diseases, exercise-induced fatigue, male infertility, and HgCl₂-induced acute renal failure. In this article, the currently available scientific literature regarding the most significant activities of astaxanthin is reviewed., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Based on the 1961-2007 meteorological data of Haikou City and its urbanization level in 1989-2007, this paper studied the climatope change and its relations with city development of the City. In 1995-2007, the mean annual air temperature in Haikou had an obvious increase, with an increment of 0.93 degrees C x a(-1), while the mean annual relative humidity decreased obviously, with a decrement of 3% per year, compared with those in 1961-1990. Both the mean annual air temperature and the mean annual relative humidity had significant correlations with the urbanization level of Haikou, suggesting that urbanization could better explain the recent 20 years variation of climate elements in Haikou. The city development of Haikou not only changed the climatope elements, but also affected the air quality, making the frequency of acid rain increased, and the mean annual acid rain pH value decreased.

Objective: To identify the antimicrobial resistance of commercial lactic acid bacteria present in microbial foods and drug additives by analyzing their isolated strains used for fermentation and probiotics., Methods: Antimicrobial susceptibility of 41 screened isolates was tested with disc diffusion and E-test methods after species-level identification. Resistant strains were selected and examined for the presence of resistance genes by PCR., Results: Distribution of resistance was found in different species. All isolates were susceptible to chloramphenicol, tetracycline, ampicillin, amoxicillin/clavulanic acid, cephalothin, and imipenem. In addition, isolates resistant to vancomycin, rifampicin, streptomycin, bacitracin, and erythromycin were detected, although the incidence of resistance to these antibiotics was relatively low. In contrast, most strains were resistant to ciprofloxacin, amikacin, trimethoprim/sulphamethoxazole, and gentamycin. The genes msrC, vanX, and dfrA were detected in strains of Enterococcus faecium, Lactobacillus plantarum, Streptococcus thermophilus, and Lactococcus lactis., Conclusion: Antibiotic resistance is present in different species of probiotic strains, which poses a threat to food safety. Evaluation of the safety of lactic acid bacteria for human consumption should be guided by established criteria, guidelines and regulations.

A gradient reversed-phase high-performance liquid chromatography (HPLC) method was developed for the rapid determination of free ergosterol, ergosteryl esters, and ergocalciferol. The HPLC method was used to evaluate the distribution of ergosterol and ergosteryl esters in the different parts (stipe, pileus, and gills) of the agaric fungi, Agrocybe aegerita, Termitomyces albuminosus, and Lentinus edodes, and the relative changes of free and esterified ergosterols during the degradation of ergosterol in the comminuted fungal tissues. The results showed that total ergosterol levels and the relative abundances of free to esterified ergosterols were different among the various species and in the different parts of these agaric fungi. The results also indicated that ergosteryl esters were more stable than free ergosterol. While the content of free ergosterol markedly decreased, substantial amounts of ergosteryl esters remained for a long period, and even an increase in the contents of ergosteryl esters was also found in some comminuted fungal tissues. Therefore, it is possible that free ergosterol in the cell membrane of the dead fungal hyphae undergoes degradation or esterification, by which excess free ergosterol may be removed, and stored in cytosolic lipid particles. It is suggested that free ergosterol (not total ergosterol) should be used as a biomarker for fungal biomass.

Flaxseed contains the largest amount of lignan secoisolariciresinol diglucoside (SDG) oligomers and is the richest dietary source of SDG. SDG oligomers in the flaxseed extract are often hydrolyzed to break the ester linkages for the release of SDG and the glycosidic bonds for the release of secoisolariciresinol (SECO). The hydrolysates of SDG oligomers are complicated because of the production of esters in an alcohol-containing medium. In this study, a new gradient reversed-phase high-performance liquid chromatography (HPLC) method has been developed to be suitable for the separation and determination of: (1) SDG oligomers extracted from the defatted flaxseed powder by a 70% aqueous methanol solution; (2) SDG oligomers and their alkaline hydrolysates, including SDG, p-coumaric acid glucoside and its methyl ester, ferulic acid glucoside and its methyl ester in an alkaline hydrolytic solution; and (3) the succedent acid hydrolysates, including secoisolariciresinol monoglucoside (SMG), SECO, anhydrosecoisolariciresinol (anhydro-SECO), p-coumaric acid and its methyl ester, ferulic acid and its methyl ester, 5-hydroxymethyl-2-furfural (HMF) and its degradation product in an acid hydrolytic solution. The content of SDG oligomers in a defatted flaxseed powder was found to be 38.5 mg/g on a dry matter basis, corresponding to a SDG content of 15.4 mg/g, which was determined after alkaline hydrolysis. Furthermore, this study presented a major reaction pathway for the hydrolysis of SDG oligomers.

The fruiting bodies, spores, and lipid from the spores of Ganoderma lucidum have been widely used for medicinal purpose in China. Ergosterol content may be a suitable marker for evaluating the quality of ganoderma spore and ganoderma spore lipid (GSL) products. A gradient reversed-phase high-performance liquid chromatography method was developed for the simultaneous determination of free and esterified ergosterols in G. lucidum. The contents of free and esterified ergosterols in the different parts (the stipe, pileus, tubes, and spores) of G. lucidum and GSL were determined. The results showed that total ergosterol levels in the stipe, pileus, tubes, and spores of G. lucidum were between 0.8 and 1.6 mg/g. The relative abundances of free to esterified ergosterol were different in the different parts of G. lucidum. The spores and the tubes, the hymenophore tissue that contains the spore-producing cells, have a considerably higher percentage of ergosteryl esters (41.9 and 39.7% of total ergosterol) in comparison with the pileus and stipe tissues (3.6 and 6.2%).

The ratios of stable carbon isotopes ((13)C/(12)C) of ganoderma fruiting body, ganoderma spore, ganoderma spore lipid (GSL) and individual fatty acids in GSL were determined by gas chromatography-stable isotope ratio mass spectrometry and elemental analysis-stable isotope ratio mass spectrometry. These values fall into a range from -26.9 to -23.3 per thousand, suggesting that the cut log as the Ganoderma-cultivated substrate in Fujian, China, may belong to C3 plants. Eighteen fatty acids were identified and their abundances measured by gas chromatography-mass spectrometry in the six GSL samples with C(16:0), C(18:0), C(18:1) and C(18:2) as major constituents, and C(16:1) is evidently enriched compared with the other edible vegetable oils. On the basis of the compositions of fatty acids and stable carbon isotopes in GSL, we have developed a novel method to detect the adulteration of GSL products with cheaper edible vegetable oils. An example of ideal blending between GSL and C4 or C3 vegetable oil is further provided to expound the discrimination procedures and corresponding sensitive indicators. Simultaneously, the carbon isotope fractionation in the biosynthesis of individual fatty acids was observed, revealing that the formation of C(18:0) from C(16:0) in ganodema spores had no conspicuous (13)C enrichment of +0.4 per thousand for Ganoderma sinensis spore and +0.1 per thousand for G. lucidum spore; the desaturation of C(18:0) to C(18:1) resulted in a distinct (13)C depletion of -1.4 per thousand for G. sinensis spore and -0.9 per thousand for G. lucidum spore; and the next desaturation from C(18:1) to C(18:2) displayed no evident (13)C fractionation of -0.1 per thousand for G. sinensis spore and -0.2 per thousand for G. lucidum spore.

Lignan is an important phytoestrogen with weakly estrogenic and anti-estrogenic properties, and possesses diverse bioactivities, including antioxidation, antitumor and antivirus etc. In particular, it may prevent hormone-dependent diseases, such as breast cancer, prostate cancer and benign prostatic hyperplasia. However, many important scientific problems have not been constrained, whether do the metabolites of lignans from foods have their potential genic toxicity? What are the anticancer mechanisms of lignans? What is the dosage of lignans to achieve the desired biological effect? In this paper, the references on lignans have systematically been reviewed in the following aspects: classification, distribution, metabolism, pharmacological activities and analytical methods, and a prospective of future studies on lignans is also elucidated.

The motility and chemotaxis system are critical for the virulence of pathogenic leptospire, which enable them to penetrate host tissue barriers during infection. The completed genome sequence of a representative virulent serovar type strain (Lai) of Leptospira interrogans serogroups Icterohaemorrhagiae (L. interrogans strain Lai) suggested that there were multiple copies of putative chemotaxis homologues located at its large chromosome. In order to verify the function of these proteins, the putative cheY genes were cloned into pQE31 vector and then expressed, respectively, in wild-type Escherichia coli strain RP437 and cheY defective strain RP5232. The results showed that all the five cheYs could restore the swarming of RP5232 strain to some extend. Overexpression of CheYs in RP437 showed inhibited swarming of RP437. To investigate the mechanism of chemotaxis signaling in L. interrogans strain Lai, certain aspartates (Asp-53, Asp-61, Asp-70, Asp-62, and Asp-66 for L. interrogans strain Lai CheY1, CheY2, CheY3, CheY4, and CheY5, respectively) were mutated. Expression of these mutated cheYs manifested neither restoration of the swarming ability of RP5232 nor inhibition on swarming ability of RP437. Multiple amino acid sequence alignment predicted ternary structures and the result of mutation experiment suggested that these conserved aspartate residues of L. interrogans were analogous to that in E. coli CheY in function and structure. So, L. interrogans and E. coli may have similar mechanisms of activation of the chemotaxis phosphorelay pathway, but there are differences in their control by signal terminator.

The motility and chemotaxis systems are critical for the virulence of leptospires. In this study, the phylogenetic profiles method was used to predict the interaction of chemotaxis proteins. It was shown that CheW1 links to CheA1, CheY, CheB and CheW2; CheW3 links to CheA2, MCP (LA2426), CheB3 and CheD1; and CheW2 links only to CheW1. The similarity analysis demonstrated that CheW2 of Leptospira interrogans strain Lai had poor homology with CheW of Escherichia coli in the region of residues 30-50. In order to verify the function of these proteins, the putative cheW genes were cloned into pQE31 vector and expressed in wild-type E. coli strain RP437 or cheW defective strain RP4606. The swarming results indicated that CheW1 and CheW3 could restore swarming of RP4606 while CheW2 could not. Overexpression of CheW1 and CheW3 in RP437 inhibited the swarming of RP437, whereas the inhibitory effect of CheW2 was much lower. Therefore, we presumed that CheW1 and CheW3 might have the function of CheW while CheW2 does not. The existence of multiple copies of chemotaxis homologue genes suggested that L. interrogans strain Lai might have a more complex chemosensory pathway.

Aim: To determine the effect of Helicobacter pylori VacA on gene expression of gastric cancer cells., Methods: Gene expression profile of a gastric cancer cell line, SGC7901, after challenged by VacA+ and VacA- H pylori broth culture supernatants (BCS), was detected by the cDNA microarray technique. Cytoskeleton changes of SGC7901 and HeLa cells were observed through high-resolution laser scanning confocal microscopy., Results: A total of 16,000 cDNA clones were detected. The percentage of genes with heterogeneous expression in SGC7901 cells challenged by VacA+ BCS reached 5%, compared with that challenged by VacA- BCS. There were 865 genes/EST with 2-fold differential expression levels and 198 genes/EST with 3-fold differential expression levels. Most of these genes were involved in vital cell events including signal transduction, regulation of gene expression, cytoskeleton, apoptosis, stress response and inflammation, cell cycle and tumor development. Cells co-cultured with VacA+ BCS showed collapsed and disrupted microtubular cytoarchitecture., Conclusion: VacA+ BCS can disrupt cytoskeletal architecture, likely through affecting the expression of cytoskeleton-associated genes, directly induce the expression of tumor promoter-related genes and inhibit the expression of tumor suppressor genes, thus favoring the development of tumors. VacA+ BCS can also alter the expression of inflammation and stress response genes. This suggests that VacA may play an important role in the pathogenicity of H pylori.

Aim: To study the immune response of host to Helicobacter pylori VacA., Methods: The monocyte/macrophage-like U937 cells were infected with Helicobacter pylori vacA-positive strain NCTC 11638 or isogenic vacA-negative mutant. Differentially expressed genes were identified at 2, 6, 10, and 24 h post-infection by cDNA microarray. Differential expressions of some genes were confirmed by Northern blot., Results: More than 100 genes altered their mRNA expression at different time points respectively, many of which were identified to be related to immune evasion., Conclusion: VacA is a crucial element for H pylori to escape from host immune defense by means of differentially regulating the expression of some related genes. These genes, previously known or unknown to be involved in the mechanism of immune evasion, deserve further investigation to unearth much more information complicated in the immune response.

Aim: To construct a vacA-knockout Helicobacter pylori mutant strain, whose only difference from the wild strain is its disrupted vacA gene., Methods and Results: A clone containing kanamycin resistance gene used for homologous recombination was constructed in a directional cloning procedure into pBluescript II SK, and then transformed into vacA+ H pylori by electroporation. Colonies growing on the selective media containing kanamycin were harvested for chromosomal DNA extraction, and the allelic exchange was determined by polymerase chain reactions and sequencing. Loss of vacuolating activity of the vacA-knockout strain was confirmed by examining the gastric cells co-cultured with cell-free supernatants from H pylori wild strain or the mutant., Conclusion: We constructed a vacA-knockout strain of H pylori through direct mutagenesis, which creates an important precondition for the future research on virulence comparison with gene expression analysis.