Diagnostic Efficacy and Possible Underlying Mechanisms of Noninvasive Clinical Markers in Hepatocellular Carcinoma.

Background and Aims: In this study, we aimed to evaluate the diagnostic values of alpha-fetoprotein (AFP), soluble AXL (sAXL), des-γ-carboxy prothrombin (DCP), the aspartate aminotransferase-to-platelet ratio index (APRI), and the gamma-glutamyl transpeptidase-to-platelet ratio (GPR) in hepatocellular carcinoma (HCC) and the possible underlying mechanisms of the correlations between them. Methods: We collected serum samples from 190, 128, and 75 patients with HCC, cirrhosis, and chronic viral hepatitis, and from 82 healthy subjects. Serum levels of AFP, sAXL, and DCP were determined, and APRI and GPR values were calculated. Receiver operating characteristic (ROC) curves were used to analyze the diagnostic value of single and combined biomarkers. Results: We detected significant differences between the HCC group and other groups regarding serum AFP, sAXL, DCP, and APRI levels. GPR significantly differed between the HCC group and other groups, except for the liver cirrhosis group. AFP, sAXL, DCP, APRI, and GPR had positive correlations with each other, and AFP showed a higher area under the curve (AUC) and Youden index values, while APRI and DCP showed the highest sensitivity and specificity. Also, when AFP was combined with sAXL, DCP, APRI, and GRP, the highest AUC (0.911) and a higher net reclassification improvement value were obtained compared with those obtained for the individual biomarkers. Conclusions: AFP, sAXL, DCP, APRI, and GPR are independent risk factors for HCC, and the diagnostic performance of AFP combined with sAXL, DCP, APRI, and GPR for HCC diagnosis was superior to that of the individual biomarkers.

Effects of pure oxygen aeration on organic pollutants removal performance and soluble microbial products characteristics of salt-tolerant activated sludge.

The effects of pure oxygen aeration on organic pollutants removal performance and effluent soluble microbial products (SMP) characteristics of salt-tolerant sludge for the treatment of wastewater with the salinity from 1.0% to 3.5% were investigated. The results showed that the oxygen transfer efficiency of the pure oxygen aeration was higher than that of the air aeration. At the low salinities (0.5%, 1.0%, 1.5%), the total organic carbon (TOC) removal rates were 71.42%, 72.88% and 76.30%, respectively, much higher than those with air aeration. However, there were no significant differences of TOC removal efficiency between the air aeration and the pure oxygen aeration at high salinities (2.5% and 3.5%). The SMP contents showed a trend of first decline and then increase generally. The content of SMP with pure oxygen aeration was lower than that with air aeration at low salinity, whereas an opposite result was obtained for salinity above 2.5%. Five excitation-emission matrix (EEM) fluorescence peaks detected in the SMP with pure oxygen aeration and air aeration were assigned to tryptophan protein-like, tyrosine protein-like and humic acid-like substances. Humic acid-like fluorescence mainly appeared in the SMP with air aeration, which may be due to respiratory failure under air aeration conditions.

Characteristics of the extracellular products of pure oxygen aerated activated sludge in batch mode.

The effects of pure oxygen aeration on compositional characteristics of soluble microbial products (SMP) and extracellular polymeric substances (EPS) of the activated sludge acclimated in a sequential batch reactor (SBR) were explored in batch mode. The structure of the extracellular products would change with different aeration methods or aeration rates. The proportion of SMP of most oxygen aerated sludge was less than 10%, while that in air aerated sludge was as high as 30-40%. The proportion of TB-EPS decreased from 56.95% to 30.63%, and the proportion of LB-EPS increased obviously with the increase of oxygen aeration rate. The contents of the protein (PN) and the polysaccharide (PS) of extracellular products with oxygen aeration were significantly different, and the PN was much higher than PS (p < 0.05). The zeta potential of each component in activated sludge was negative, gradually decreasing with the progress of biological treatment. The fluorescence peaks in SMP, LB-EPS and TB-EPS with pure oxygen aeration were attributed to tryptophan PN-like and humic acid-like fractions. The results showed that the proportion of the components in the extracellular products could be regulated by adjusting the aeration rate and aeration mode, so as to optimize the treatment process of activated sludge.

Direct growth of m-BiVO4@carbon fibers for highly efficient and recyclable photocatalytic and antibacterial applications.

Owing to photocatalytic and antibacterial properties, bismuth based oxides has drawn much attention in recent past. However, non-recyclability of these oxides has restricted their practical applications. In present work, a novel nanostructured composite monoclinic bismuth vanadate@ activated carbon fibers (BiVO4@ACF) photocatalyst was efficaciously synthesized using a solvothermal method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Bruner-Emmett-Teller (BET). The specific surface area, phase composition, microstructure, binding and photocatalytic activity of BiVO4@ACF pose great dependence on solvent nature and chelating agents utilized for synthesis. The photocatalytic and antibacterial potential of this composite was evaluated and optimized by using a model pollutant, Reactive Rhodamine Blue (RhB) and pathogenic microbes (Escherichia coli and Staphylococcus aureus). The composite possesses enhanced photocatalytic and antibacterial activity and was reutilized for three rounds of respective reaction without any loss of activity and structure as evident from SEM and XRD results. The photocatalytic mechanism of photodegradation of dye and bactericidal properties of samples under visible light irradiation was determined by scavenger and photoluminescence (PL) spectroscopy. The enhanced photocatalytic and antibacterial activity, chemical stability and most importantly good recyclability of BiVO4@ACFs highlight the potential application of this composite in water purification and other biological applications.

Aggregation-induced responses (AIR) of 2D-derived layered nanostructures enable emerging colorimetric and fluorescence sensors.

Layered nanostructures (LNs), including two-dimensional nanosheets, nanoflakes, and planar nanodots, show large surface-to-volume ratios, unique optical properties, and desired interfacial activities. LNs are highly promising as alternative probes and platforms due to numerous merits, e.g. signal amplification, improved recognition ability, and anti-interference capacity, for emerging sensing applications. Significantly, when stimuli-responsive aggregation occurs, the modified LNs show engineered morphologies, attractive optical absorption and fluorescence characteristics, which are remarkably programmable. On the basis of the altered aggregation behaviours of LNs, as well as their modulated physical and chemical characteristics, a series of novel sensing assays exhibiting enhanced sensitivity, simple operation, multiple functions, and improved anti-interference capacity are reported, contributing to both point-of-care testing and high-throughput measurements. Herein, the aggregation-induced response sensing strategies of LNs are comprehensively summarized with the classification of materials and variation of aggregated routes aiming at understanding dimension-dependent features, expanding nanoscale biosensor applications, and addressing key issues in disease diagnosis and environmental analysis.

Z-scheme 2D-m-BiVO4 networks decorated by a g-CN nanosheet heterostructured photocatalyst with an excellent response to visible light.

For economical water splitting and degradation of toxic organic dyes, the development of inexpensive, efficient, and stable photocatalysts capable of harvesting visible light is essential. In this study, we designed a model system by grafting graphitic carbon nitride (g-C3N4) (g-CN) nanosheets on the surface of 2D monoclinic bismuth vanadate (m-BiVO4) nanoplates by a simple hydrothermal method. This as-synthesized photocatalyst has well-dispersed g-CN nanosheets on the surface of the nanoplates of m-BiVO4, thus forming a heterojunction with a high specific surface area. The degradation rate for bromophenol blue (BPB) shown by BiVO4/g-CN is 96% and that for methylene blue (MB) is 98% within 1 h and 25 min, respectively. The 2D BiVO4/g-CN heterostructure system also shows outstanding durability and retains up to ∼95% degradation efficiency for the MB dye even after eight consecutive cycles; the degradation efficiency for BPB does not change too much after eight consecutive cycles as well. The enhanced photocatalytic activities of BiVO4/g-CN are attributed to the larger surface area, larger number of surface active sites, fast charge transfer and improved separation of photogenerated charge carriers. We proposed a mechanism for the improved photocatalytic performance of the Z-scheme photocatalytic system. The present work gives a good example for the development of a novel Z-scheme heterojunction with good stability and high photocatalytic activity for toxic organic dye degradation and water splitting applications.

Ability of prebiotic polysaccharides to activate a HIF1α-antimicrobial peptide axis determines liver injury risk in zebrafish.

Natural polysaccharides have received much attention for their ability to ameliorate hepatic steatosis induced by high-fat diet. However, the potential risks of their use have been less investigated. Here, we show that the exopolysaccharides (EPS) from Lactobacillus rhamnosus GG (LGG) and L. casei BL23 reduce hepatic steatosis in zebrafish fed a high-fat diet, while BL23 EPS, but not LGG EPS, induce liver inflammation and injury. This is due to the fact that BL23 EPS induces gut microbial dysbiosis, while LGG EPS promotes microbial homeostasis. We find that LGG EPS, but not BL23 EPS, can directly activate intestinal HIF1α, and increased HIF1α boosts local antimicrobial peptide expression to facilitate microbial homeostasis, explaining the distinct compositions of LGG EPS- and BL23 EPS-associated microbiota. Finally, we find that liver injury risk is not confined to Lactobacillus-derived EPS but extends to other types of commonly used natural polysaccharides, depending on their HIF1α activation efficiency.

Prevalence and Risk Factors of Stress Urinary Incontinence Among Perimenopausal Women and Its Influence on Daily Life in Women with Sexual Desire Problem.

The prevalence of, and related factors to, stress urinary incontinence (SUI) among perimenopausal Chinese women and its impact on daily life among those women with sexual desire problem in Hubei province were investigated. In this study, 1519 perimenopausal women aged 40 to 65 years were selected from three urban communities in the Wuhan area, and two impoverished, mountainous communities in Hubei province, and followed from April to October 2014. Detailed information about demographic characteristics, menstruation, pregnancy, sexual life and chronic diseases was collected. A cross-sectional survey was carried out following information collection by Chi-square test and multiple logistic regression analysis. Univariate and multivariate logistic regression analysis demonstrated that the potential factors associated with developing SUI were old age (OR=3.4, 95% CI: 1.92-6.04), vaginal delivery (OR=0.623, 95% CI: 0.45-0.87), low income (OR=0.063, 95% CI: 0.40-0.92), atrophic vaginitis (OR=1.4, 95% CI: 1.03-1.80), pelvic organ prolapse (OR=2.81, 95% CI: 1.36-5.80), chronic pelvic pain (OR=2.17, 95% CI: 1.90-4.03), constipation (OR=1.44, 95% CI: 1.07-1.93) and incontinence of feces (OR=3.32, 95% CI: 2.03-5.43). Moreover, the ratio of SUI (33.2%) was higher than the ratio of urgency urinary incontinence (24.1%) or the ratio of mixed urinary incontinence (17.4%), and SUI had a greater impact on daily life among women with decreased sexual desire. In conclusion, SUI is a common disorder affecting over one third of the women surveyed, and has a severe impact on the daily life of perimenopausal women with declined sexual desire. Age, mode of delivery, and monthly income are major risk factors involved in the development of SUI.

Organic degradation and extracellular products of pure oxygen aerated activated sludge under different F/M conditions.

This study aimed to investigate the effect of food to microorganisms rate (F/M) on organic removal, extracellular polymeric substances (EPS) and soluble microbial products (SMP) of the pure oxygen aerated activated sludge running in batch mode. The F/M rates were controlled by adjusting the MLSS concentrations (2000, 5000, 8000 mg/L) and/or the initial TOC concentrations (100, 500 mg/L). Results showed that at high F/M rate (0.25 kg TOC/kg MLSS), the substrate degradation rate in the oxygen aerated reactor could reach 1.347 mg TOC/(L·min)), much higher than that in the air aerated reactor (0.640 mg TOC/(L·min)). The SMP concentrations with oxygen aeration were also higher than those with air aeration under high F/M conditions. The total EPS contents in the pure oxygen aerated sludge were significantly lower regardless of the different F/M rates. High F/M condition would lead to more amount of polysaccharides synthesis rather than proteins synthesis in EPS.

In situ self-sacrificed template synthesis of vanadium nitride/nitrogen-doped graphene nanocomposites for electrochemical capacitors.

Vanadium nitride and graphene have been widely used as pseudo-capacitive and electric double-layer capacitor electrode materials for electrochemical capacitors, respectively. However, the poor cycling stability of vanadium nitride and the low capacitance of graphene impeded their practical applications. Herein, we demonstrated an in situ self-sacrificed template method for the synthesis of vanadium nitride/nitrogen-doped graphene (VN/NGr) nanocomposites by the pyrolysis of a mixture of dicyandiamide, glucose, and NH4VO3. Vanadium nitride nanoparticles of the size in the range of 2 to 7 nm were uniformly embedded into the nitrogen-doped graphene skeleton. Furthermore, the VN/NGr nanocomposites with a high specific surface area and pore volume showed a high specific capacitance of 255 F g-1 at 10 mV s-1, and an excellent cycling stability (94% capacitance retention after 2000 cycles). The excellent capacitive properties were ascribed to the excellent conductivity of nitrogen-doped graphene, high surface area, high pore volume, and the synergistic effect between vanadium nitride and nitrogen-doped graphene.

Structure-Based Discovery of Nonpeptide Allatostatin Analogues for Pest Control.

FGLamide allatostatins (ASTs) are regarded as possible insecticide candidates, although their lack of in vivo effects, rapid degradation, poor water solubility, and high production costs preclude their practical use in pest control. In contrast to previous research, the C-terminal tripeptide (FGLa) was selected as the lead compound in this study. Five nonpeptide AST analogues (2-amino-1-[3-oxo-3-(substituted-anilino)propyl]pyridinium nitrate derivatives) were designed on the basis of the structure-activity relationship and docking results of FGLa. All of the nonpeptide analogues (S1-S5) were more potent against juvenile-hormone (JH) biosynthesis than the lead compound. They significantly inhibited the biosynthesis of JH in vivo following injection. A pest-control application demonstrated that S1 and S3 have larvicidal effects following oral administration (the IC50 values were 0.020 and 0.0016 mg/g, respectively). The good oral toxicities and excellent water solubilities of S1 and S3 suggest that they have considerable potential as insecticides for pest management.

Prevalence and risk factors of urinary incontinence among perimenopausal women in Wuhan.

This study investigated the prevalence and risk factors of urinary incontinence (UI) among perimenopausal women in Wuhan. A cross-sectional survey was performed on 1067 women aged 40-65 years sampled in Wuhan urban area from April to October 2014. Information about demographic characteristics, menstruation, parity and UI symptoms was collected using a questionnaire. The data were evaluated by Chi-square test and multiple Logistic regression analysis. The prevalence rate of UI was 37.2%, with stress UI (32.2%) being more prevalent than urgency UI (21.6%) and mixed UI (16.6%). 31.2% women with UI stated that UI had negative impact on their life. Risk factors for UI included menstrual disorder, menopause, overweight, perineal laceration, atrophic vaginitis, constipation and pelvic organ prolapse. Appropriate investigation apropos the factors associated with UI should be performed to diminish its impact on women's life.

The Efficacy of Aspirin in Preventing the Recurrence of Colorectal Adenoma: a Renewed Meta-Analysis of Randomized Trials.

BACKGROUND: Through search the possible randomized control trials, we make a renewed meta-analysis in order to assess the impact of aspirin in preventing the recurrence of colorectal adenoma. MATERIALS AND METHODS: The Medicine/PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Chinese biomedical literature service system (SinoMed) databases were searched for the related randomized controlled trials until to the April 2016. Three different authors respectively evaluated the quality of studies and extracted data, and we used the STATA software to analyze, investigate heterogeneity between the data, using the fixed-effects model to calculate and merge data. RESULTS: 7 papers were included the renewed meta- analysis, among these studies, two pairs were identified as representing the same study population, with the only difference being the duration of follow-up. Thus there were only five papers included our meta-analysis, and one Chinese paper were also included the work. Results were categorized by the length of follow-up, different kinds of people, varied dose of oral aspirin. The relative of adenoma in patients taking aspirin vs placebo were 0.73 (95% CI 0.55-0.98, P=0.039) with 1 year follow up; 0.84 (95% CI 0.72-0.98, P=0.484) with greater than 1 year follow up; for the advanced adenoma, the RR 0.68 (95% CI 0.49-0.94, P=0.582),for one year; RR=0.75 (95% CI 0.52-1.07, P=0.552) for greater one year. Furthermore the white population could divided into two subgroups according to the different length of follow-up time. When the length of follow-up time less than 3-year, The RR of two subgroups respective were RR=0.86 (95% CI 0.76-0.98, P=0.332), I2=0%, RR=0.68 (95% CI 0.47-0.98, P=0.552), I2=64.6%, But with the extension of follow-up time greater than 2-year, with the white, oral aspirin without considering dose had no efficacy on preventing the recurrence of any adenoma, the RR was 0.86 (95% CI 0.71-1.05, P=0.302), I2=16.4%. CONCLUSIONS: This meta-analysis indicated that oral aspirin is associated with a remarkable decrease in the recurrence of any adenoma and advanced adenomas in patients follow-up for 1 year without concerning the dose of aspirin, but with the extension of follow-up time for greater than 1 year, oral aspirin can be effective on preventing the recurrence of any adenoma, but for the advanced adenoma, the result indicated that oral aspirin had no efficacy, According to the inclusion of ethnic groups, we also divided relevant papers into two subgroups as the yellow and white group. Then the follow-up time was less than 3 years, oral aspirin without considering the dose, had an significant efficacy on preventing the recurrence of any adenoma. But with the follow-up greater than 2 years, oral aspirin had no effect in the white.

[Morphological characteristics and gene expression of Chrysomya megacephala eggs in different developmental stages].

OBJECTIVE: To research the morphological characteristics and differential gene expression of Chrysomya megacephala eggs in different developmental stages. METHODS: After C. megacephala laid eggs (0 h), the eggs were collected every 2 h until eggs hatched into larvae. The morphological characteristics of C. megacephala eggs in different developmental stages were observed by stereo microscopy and scanning electron microscopy. The total RNA of the fly eggs was extracted. The expression levels of bicoid, slalom and chitin synthase genes was determined by real-time flourescence quantitative PCR. Statistic analyses were performed with SPSS 19.0. RESULTS: Under the stereomicroscope, at 0-4 h after egg laying, the morphological change of C. megacephala eggs was not obvious. At the 6th hour after egg laying, somites were formed. After 8 hours the eggs shriveled. At the 9th hour after egg laying, the eggs hatched into larvae. The scanning electron microscope images showed that the morphological change of eggs was not obvious in the first 4 hours, the end of micropyle slightly outward, the surface around the micropyle was smooth. At the 6th hour after egg laying, the end of micropyle began to sag and irregular protrusions formed around the micropyle. At the 8th hour the end of micropyle was obviously dented. After 9 hours larvae hatched from eggs. Real-time fluorescence quantitative PCR indicated that the expression levels of bicoid, slalom and chitin synthase genes from C. megacephala eggs regularly changed with the developmental stages. There was a significant difference in threshold cycle values among the three genes (P<0.05). CONCLUSION: The morphological characteristics of C. megacephala eggs change with the development stage. The levels of gene expression in different development period of C. megacephala eggs are different.

Celecoxib regulates apoptosis and autophagy via the PI3K/Akt signaling pathway in SGC-7901 gastric cancer cells.

Gastric cancer, one of the most common malignancies worldwide, typically has a poor prognosis and poor survival rate. Previous studies have investigated the chemopreventive effect of celecoxib. In the present study, the SGC-7901 human gastric cancer cell line was utilized to examine the chemopreventive mechanisms of celecoxib. The inhibition of cell proliferation was determined using MTT assay, cell apoptosis was monitored by terminal deoxynucleotidyl transferase-mediated dUTP nick end­labeling (TUNEL) and flow cytometry, and cell ultrastructural changes were assessed via transmission electron microscopy. The mRNA expression of Akt, caspase-8 and -9 was examined using quantitative reverse-transcription-polymerase chain reaction (qRT-PCR) and p-Akt, procaspase-8 and -9 were analyzed via western blotting. The results showed that celecoxib inhibited the proliferation of SGC-7901 cells in a time- and dose-dependent manner. Additionally, celecoxib induced apoptosis as substantiated by typical apoptotic bodies, autophagosomes and an increased apoptotic rate. It was found that following celecoxib treatment, Akt mRNA expression was not significantly altered, and that p-Akt protein levels decreased in a time- and dose­dependent manner. Additionally, caspase-8 and -9 mRNA expression was significantly increased, while procaspase-8 and -9 protein expression decreased relative to the time- and dose-dependent effects. These results demonstrated that celecoxib induced apoptosis and autophagy of gastric cancer cells in vitro through the PI3K/Akt signaling pathway. Moreover, our findings suggested that celecoxib induces apoptosis in gastric cancer cells through the mitochondrial and death receptor pathways, providing additional understanding regarding the chemopreventive behaviors of celecoxib and its uses in cancer therapy.

N,N'-Diphenyl-9,10-dioxo-9,10-di-hydro-anthracene-2,7-disulfonamide.

The title mol-ecule, C26H18N2O6S2, has an overall Z-shaped conformation, in which the benzene rings are inclined to the anthra-quinone mean plane by 60.60 (9) and 50.66 (13)°. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds link the mol-ecules into layers parallel to the bc plane.

[The influence of CD44 on the adhesive, migratory and infiltrative abilities of leukemia cells].

OBJECTIVE: To investigate the expression of CD44 in leukemia cell lines and its role in adhesion, migration and infiltration of leukemia cells. METHODS: The expression levels of CD44 in four leukemia cell lines SHI-1, THP-1, NB4 and K562 were assayed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot when they were in logarithmic phase. And these cell lines were divided into control group (treated with same species and isotype IgG) and experimental group (treated with anti-CD44 mono-clonal antibody). The assays of cell-cell adhesion to endothelial cells line ECV304, migration through the artificial matrix membrane and infiltration through the Matrigel were performed. RESULTS: The relative expression ratios of CD44 to GAPDH in SHI-1, THP-1, NB4 cells were 0.0731 ± 0.0072, 0.0827 ± 0.0151 and 0.1473 ± 0.0365, respectively, which were significantly higher than that in K562 cells (0.0002 ± 0.0000, P < 0.01). Cell-cell adhesion assay showed that the adhesion rates of SHI-1, THP-1 and NB4 cells in the experimental group decreased to 72.78%, 64.09% and 57.42%, respectively, and were lower than those of the control groups, while that of K562 cells in the experimental group was 106.16%. Migration assay showed that the transmembrane rates of SHI-1,THP-1 and NB4 cells were 55%, 29% and 25% in the control group, respectively, and decreased to 32%, 18% and 12% in the experimental group, respectively, while those of K562 cells in both control group and experimental group remained 2%. The infiltration rates of SHI-1, THP-1 and NB4 cells decreased from 24%, 15% and 13% in the control group to 12%, 8% and 4% in the experimental group, respectively, while K562 cells in both groups could not pass through the Matrigel. CONCLUSION: CD44 antigen might play an important role in the adhesion, migration and infiltration of leukemia cells and be involved in the extra-medullary infiltration of leukemia cells.

[Rainfall intensity effects on nutrients transport in surface runoff from farmlands in gentle slope hilly area of Taihu Lake Basin].

To investigate the effect of rainfall on agricultural nonpoint source pollution, watershed scale experiments were conducted to study the characteristics of nutrients in surface runoff under different rainfall intensities from farmlands in gentle slope hilly areas around Taihu Lake. Rainfall intensity significantly affected N and P concentrations in runoff. Rainfall intensity was positively related to TP, PO4(3-) -P and NH4+ -N event mean concentrations(EMC). However, this study have found the EMC of TN and NO3- -N to be positively related to rainfall intensity under light rain and negatively related to rainfall intensity under heavy rain. TN and TP site mean amounts (SMA) in runoff were positively related to rainfall intensity and were 1.91, 311.83, 127.65, 731.69 g/hm2 and 0.04, 7.77, 2.99, 32.02 g/hm2 with rainfall applied under light rain, moderate rain, heavy rain and rainstorm respectively. N in runoff was mainly NO3- -N and NH4+ -N and was primarily in dissolved form from Meilin soils. Dissolved P (DP) was the dominant form of TP under light rain, but particulate P (PP) mass loss increased with the increase of rainfall intensity and to be the dominant form when the rainfall intensity reaches rainstorm. Single relationships were used to describe the dependence of TN and TP mass losses in runoff on rainfall, maximum rainfall intensity, average rainfall intensity and rainfall duration respectively. The results showed a significant positive correlation between TN mass loss and rainfall, maximum rainfall intensity respectively (p < 0.01) and also TP mass loss and rainfall, maximum rainfall intensity respectively (p < 0.01).

A high efficient method of constructing recombinant Bombyx mori (silkworm) multiple nucleopolyhedrovirus based on zero-background Tn7-mediated transposition in Escherichia coli.

A high efficient way for generation of recombinant Bombyx mori (silkworm) multiple nucleopolyhedrovirus by Tn7-mediated transposition in Escherichia coli was performed. The new system consists of a conditional replication donor vector pRCDM and an attTn7 site blocked E. coli containing BmNPV-Bacmid. The donor vector contains a replication origin derived from R6Kgamma, which propagated only in host cells with pir gene expression decreased in the transposition background greatly. Compared with original vector derived from pUC, the transposition efficiency increased from 5.7 to 66% ( approximately 10 fold) when using conditional replication vector pRCDM transposition into original BmDH10Bac. A further effort to decrease the transposition background was made by blocking the attTn7 site in host E. coli genome. The resulting attTn7 occupied BmDH10BacDeltaTn7 resulted in a significant increase from 5.7 to 23% ( approximately 4 fold) in the efficacy of generate recombinant BmNPV Bacmid by transposition. Furthermore, the transposition of BmDH10BacDeltaTn7 with pRCDM resulted typically in 100% white colonies, and it indicated that a zero transposition background was accomplished. This high efficient and zero background transposition system provides a new simple and rapid method for construction of recombinant BmNPV used to express target genes or produce gene-delivery virus particles in silkworm.

[Principal physicochemical properties of artificial soil composed of sewage sludge stabilized by fly ash].

The pH, nutrients and heavy metals of stabilized sewage sludge were investigated by mixing municipal sewage sludge with alkaline fly ash and mine tailing. The results indicate that water-holding capacity of artificial soil III (FA : SS = 1 : 1) and II (FA : SS = 2 : 1) treatments were significantly higher than that of CK (brown meadow soil), while that of the IV (FA : SS = 1 : 2) treatment was similar to CK; The nutrients contents (organic matter, N, P, K) of stabilized sewage sludge were up to a high fertilizer level. Moreover, with decrease of the ratio of fly ash to sewage sludge, the nutrient content of artificial soils increased. Except total Ni content of III (FA : SS = 1 : 1) treatment was high (187.67 mg x kg(-1)), Cd, Pb, Cu, Zn, and Cr for all artificial soil treatments were all significant lower than control standards for pollutants in sludges and fly ash from Agricultural use (GB 4284-84, GB 8173-87).