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The synergetic effect and underlying mechanism of potassium ferrate (PF) with tea saponin (TS, a biosurfactant) in producing short chain fatty acids (SCFAs) from anaerobic fermentation of waste activated sludge (WAS) were explored in this work. Experimental results showed that 0.2 g PF (g TSS)−1 (total suspended solid) combined with 0.02 g TS (g TSS)−1 could further improve SCFAs' production, and the maximum SCFAs content reached 2008.7 mg COD L−1, which is 1.2 and 4.5 times higher than those with PF and TS individually added, respectively, and 5.3 times higher than that of blank WAS on Day 12. In the model substrates experiments, the degradation rates of bovine serum albumin and dextran with combination of PF and TS were 41.3%±0.1% and 48.5%±0.06%, respectively, on Day 3, which are lower than those in blank WAS (with degradation rates of 72.3%±0.5% and 90.3%±0.3%). It was revealed that the oxidative effect of PF and the solubilization of TS caused more organic matters to be dissolved out from WAS, providing a large number of biodegradable substances for subsequent SCFAs production. While WAS pretreated with the combination of PF and TS, the relative abundances of Firmicutes increased from 6.4% (blank) to 38.6%, and that of Proteobacteria decreased from 41.8% (blank) to 21.8%. The combination of PF and TS promoted the hydrolysis process of WAS by enriching Firmicutes, and then increased acetic acid production by inhibiting Proteobacteria that consumed SCFAs. Meanwhile, at the genus level, acidogenesis bacteria (e.g., Proteiniclasticum and Petrimonas) were enriched whereas SCFAs consuming bacteria (e.g., Dokdonella) were inhibited. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of potassium ferrate (PF) and low-temperature thermal hydrolysis co-pretreatment on the promotion of sludge hydrolysis process and the impact on acid production in the subsequent anaerobic digestion process. The analytical investigations showed that co-pretreatment significantly facilitated the hydrolysis process of the sludge and contributed to the accumulation of short-chain fatty acids (SCFAs). The pretreatment conditions under the optimal leaching of organic matter from sludge were hydrothermal temperature of 75°C, hydrothermal treatment time of 12 h, and PF dosage of 0.25 g g−1 TSS (total suspended solids), according to the results of orthogonal experiments. By pretreatment under proper conditions, the removal rate of soluble chemical oxygen demand (SCOD) achieved 71.8% at the end of fermentation and the removal rate of total phosphorus (TP) was 69.1%. The maximum yield of SCFAs was 750.3 mg L−1, 7.45 times greater than that of the blank group. Based on the analysis of the anaerobic digestion mechanism, it was indicated that the co-pretreatment could destroy the floc structure on the sludge surface and improve organic matter dissolving, resulting in more soluble organic substances for the acidification process. Furthermore, microbial community research revealed that the main cause of enhanced SCFAs generation was an increase in acidogenic bacteria and a reduction of methanogenic bacteria. [ABSTRACT FROM AUTHOR]

Purpose: Radiotherapy is an indispensable treatment for esophageal cancer (EC), but radioresistance is not uncommon. Curcumol, as an active extract from traditional Chinese medicines, has been reported to have antitumor activity in various types of human tumor cells. However, its reversal of radioresistance has been rarely reported. Materials and methods: In the present study, curcumol was prepared as an inclusion complex with β-cyclodextrin. EC cell lines were treated with radiation and curcumol β-cyclodextrin inclusion complex (CβC), and the effect of radiosensitization of CβC was investigated in vitro and in vivo. The in vitro experiments included cell proliferation assay, clonogenic survival assay, apoptosis assay, cell cycle assay, and western blot assay. Results: The in vitro data revealed that CβC and irradiation synergistically inhibited the proliferation, reduced the colony formation, promoted the apoptosis, increased the G2/M phase, inhibited DNA damage repair, and reversed the hypoxia-mediated radioresistance of EC cells to a greater extent than did CβC alone or irradiation alone. The sensitization enhancement ratios (SERs) were 1.39 for TE-1 and 1.48 for ECA109 under hypoxia. The SERs were 1.25 for TE-1 and 1.32 for ECA109 under normoxia. The in vivo data demonstrated that the combination of CβC and irradiation could inhibit tumor growth to the greatest extent compared with either monotherapy alone. The enhancement factor was 2.45. Conclusion: This study demonstrated that CβC could enhance radiosensitivity of EC cells under hypoxic and normoxic condition. Thus, CβC can be used as an effective radiosensitizer for EC. [ABSTRACT FROM AUTHOR]

Maneuverability is one of the important tactical and technical indexes of fighter aircraft. In this paper, the finite element method is used to establish a dynamic model of the rotor system that can consider arbitrary maneuvering flight form and rotor speed variation during the flight, and the vibration characteristic of the dynamic model is investigated in detail. In addition, the nonlinear forces caused by bearings and oil film are also considered. The Newmark-β method combined with Newton-Raphson method is adopted to solve the dynamic equations. The influences of speed variation, rolling, pitching, and yawing maneuver loads on the vibration responses of the rotor system are also evaluated. [ABSTRACT FROM AUTHOR]

A precise and reliable analytical method of high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed to measure trace levels of enrofloxacin (ENR) and its major metabolite ciprofloxacin (CIP) in carp tissues. Optimized chromatographic separation was obtained on a Waters Xterra MS C18 reversed-phase column using gradient elution with methanol and 0.1% formic acid aqueous solution including 5 mmol L−1 of ammonium acetate. The established method was applied to study the pharmacokinetics and distribution of ENR and CIP in tissues of carp following a single oral administration in feed at a dosage of 40 mg kg−1 bw (body weight). Data were analyzed using DAS 2.0 dynamics software, and the experimental results suggest that ENR was rapidly absorbed and extensively distributed in carp tissues through systemic circulation, and the pharmacokinetic characteristics can be described with a two-compartment model. The elimination half-lives (t1/2β) from muscle, liver, gill, plasma and skin were 131, 160, 104, 132 and 310 h, respectively. The areas under the drug concentration-time curves (AUC) for these tissues were 491, 972, 750, 249 and 706 h mg kg−1, respectively. The maximum concentration (Cmax) values were 13, 29, 37, 9 and 5 mg kg−1 with peak times (tmax) of 8, 4, 4, 2 and 4 h, respectively. Ciprofloxacin, the active metabolite of ENR, was also detected in carp tissues, indicating that only 1.54% of de-ethylation of ENR occurs in carp. At a water temperature of 18°C, the drug withdrawal time was determined to be no less than 24 d while the carp was fed at a single dosage of 40 mg kg−1. [ABSTRACT FROM AUTHOR]

In this paper, a flexible tether-net system is applied to capture the space debris and a numerical framework is established to explore its nonlinear dynamic behaviors, which comprises four principal phases: folding, spreading, contacting, and closing. Based on the discretization of the whole structure into multiple nodes and connected edges, elastic force vectors and associated Jacobian matrix are derived analytically to solve a series of equations of motion. With a fully implicit method applied to analyze the nonlinear dynamics of a slender rod network, the involved mechanical responses are investigated numerically accounting for the interactions. Contact between the deformable net and a rigid body is handled implicitly through a cost-effective modified mass algorithm while the catenary theory is utilized to guide the folding process (from planar configuration to origami-like pattern). The dragging and spreading actions for the folded hexagon net could be realized by shooting six corner mass toward a specific direction; next, the six corners would be controlled to move along a prescribed path producing a closing gesture, when touch between the flying net and the target body is detected, so that for the space debris could be captured and removed successfully. We think the established discrete model could provide a novel insight in the design of active debris removal (ADR) techniques and promote further development of the model-based control of tether tugging systems. [ABSTRACT FROM AUTHOR]

Global air pollution is a serious problem, and the chemical components in PM can facilitate the invasion of biological components in the human body. However, previous studies have paid little attention to the health risks associated with fungi, as opposed to those associated with bacteria and viruses. This study analyzed fungal community structures, diversity and nutrition acquisition patterns under different weather conditions (sun, haze and dust). The results showed that the characteristics of the fungal community changed significantly when special weather occurred. Diversity and uniformity increased significantly, and the increase on haze days was greater than that on dust days. The dominant genera of fungi on sunny days were Periconia (26.76%) and Alternaria (27.56%), and the dominant genus of fungi on haze and dust days was Aspergillus (70.34 and 86.82%, respectively). According to the calculation of the concentration of cultivable fungi, the HI value on haze days was 1.43 times greater than that on sunny days. The exposure risk in adults was greater than that in children (adults (Age: 18–60) > adults (Age: > 60) > children (Age: 0–5) > children (Age: 6–17)). Within the same age group, the exposure risk in males was greater than that in females. According to the species annotation results, the relative abundance of dangerous fungi under special weather increased significantly, and the interaction between PM and microorganisms increased the health risk posed by special weather-related fungi in humans. The FUNGuild gene annotation results revealed that the pathogenic fungus content on sunny days was higher than those on haze and dust days, so the health risks associated with sunny days should not be ignored. [ABSTRACT FROM AUTHOR]

Continued innovation in screening methodologies remains important for the discovery of high-quality multiactive fungi, which have been of great significance to the development of new drugs. Mangrove-derived fungi, which are well recognized as prolific sources of natural products, are worth sustained attention and further study. In this study, 118 fungi, which mainly included Aspergillus spp. (34.62%) and Penicillium spp. (15.38%), were isolated from the mangrove ecosystem of the Maowei Sea, and 83.1% of the cultured fungi showed at least one bioactivity in four antibacterial and three antioxidant assays. To accurately evaluate the fungal bioactivities, the fungi with multiple bioactivities were successfully evaluated and screened by principal component analysis (PCA), and this analysis provided a dataset for comparing and selecting multibioactive fungi. Among the 118 mangrove-derived fungi tested in this study, Aspergillus spp. showed the best comprehensive activity. Fungi such as A. clavatonanicus, A. flavipes and A. citrinoterreus, which exhibited high comprehensive bioactivity as determined by the PCA, have great potential in the exploitation of natural products and the development of new drugs. This study demonstrated the first use of PCA as a time-saving, scientific method with a strong ability to evaluate and screen multiactive fungi, which indicated that this method can affect the discovery and development of new drugs. [ABSTRACT FROM AUTHOR]

Rolling bearing and squeeze film damper will introduce structural nonlinearity into the dynamic model of aeroengine. Rubbing will occur due to the clearance reduction design of the engine. The coupling of structural nonlinearity and fault nonlinearity will make the engine present rich vibration responses. This paper aims to analyze the nonlinear vibration behavior of the whole aeroengine including rolling bearing and squeeze film damper under rubbing fault. Firstly, the dynamic model of a turboshaft engine with nonlinear support and rubbing fault is established; The rolling bearing force, the oil film force and the rubbing force are introduced into a dual-rotor–casing model with six support points. Secondly, the linear part of the model is verified by the dynamic characteristics of the three-dimensional finite element model. Finally, the varying compliance vibration, the damping effect and the bifurcation mechanism are analyzed in detail in which the bearing clearance, speed ratio and rubbing stiffness are considered. Results show that the rubbing fault in the nonlinear support case will excite more significant varying compliance vibration in the low-speed region and expand the rotating speed range of the chaotic region in the high-speed region compared with that in the linear support case. [ABSTRACT FROM AUTHOR]

We investigated the degradation behavior of amorphous silicon nitride (Si3N4) fibers in low air pressure and presumed the evolution mechanism. The obtained Si3N4 fibers were characterized by tensile strength, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and elemental analysis after being annealed (air pressure: 1 Pa–0.1 MPa, temperature: 1000–1600 °C, dwell time: 0–4 h). When air pressure was lower than 100 Pa or higher than 1000 Pa the strength of fibers dropped sharply. Due to the moderate partial pressure of oxygen in 100–1000 Pa, both active oxidation and passive oxidation were restrained resulting in the best mechanical property of fibers in 100–1000 Pa. Besides air pressure, annealing time also affected the thermal behavior of fibers. Firstly Si3N4 fibers were passive oxidized to form SiO2 layer on the surface, and then Si3N4 decomposed into free Si and SiO2 released gaseous SiO. Finally crystallization inside of fibers and formation of nanowires on the outer surface played the leading role in the progress of degradation. [ABSTRACT FROM AUTHOR]

As dye demand continues to rapidly increase in the food, pharmaceutical, cosmetic, paper, textile, and leather industries, an industrialization increase is occurring. Meanwhile, the degradation and removal of azo dyes have raised broad concern regarding the hazards posed by these dyes to the ecological environment and human health. Physicochemical treatments have been applied but are hindered by high energy and economic costs, high sludge production, and chemicals handling. Comparatively, the bioremediation technique is an eco-friendly, removal-efficient, and cost-competitive method to resolve the problem. This paper provides scientific and technical information about recent advances in the biodegradation of azo dyes. It expands the biodegradation efficiency, characteristics, and mechanisms of various microorganisms containing bacteria, fungi, microalgae, and microbial consortia, which have been reported to biodegrade azo dyes. In addition, information about physicochemical factors affecting dye biodegradation has been compiled. Furthermore, this paper also sketches the recent development and characteristics of advanced bioreactors. [ABSTRACT FROM AUTHOR]

The area of East China Sea (ECS) inner shelf is an important sink of suspended particulates from Yangtze River (YR) and materials originated from YR basin. In this study, the parameters of lignin and alkane biomarkers in surface sediment samples from ECS inner shelf were determined to distinguish the sources and to trace the transport of terrigenous organic matters in the region. Our dataset showed that total alkanes with carbon numbers from 10 to 38 (T-alkanes) were significantly correlated to both TAR (terrigenous/aquatic ratio) and HMW/LMW (the ratio of high molecular weight to low molecular weight alkanes) (r =0.88, P<0.05 for both), indicating that the majority of T-alkanes was predominantly originated from terrestrial sources, and T-alkanes are important constituents of terrestrial organic matters in the study area. The area was probably affected by petroleum pollution to a certain degree, as indicated by the values of carbon preference index (CPI), odd-over-even carbon number predominance (OEP) and the ratio of pristane to phytane (Pr/Ph). The values of Pr/n-C17 and Ph/n-C18 suggested a strong reductive sedimentary condition in the region with no obvious biodegradation. The content of eight lignin phenols (Σ8) decreased from the coast to the open sea, indicative of riverine input and hydrodynamic transport of terrigenous organic matters. Lignin degradation parameters presented an increasing trend from the coastline toward the open sea. The lignin vegetation parameters and alkane index (AI) suggested the predominance of non-woody angiosperms in the YR basin. The obvious correlation between Λ8 (Σ8 normalized to 100 mg organic carbon), TAR and HMW/LMW reveals the significantly concurrent input of lignin and alkanes from terrestrial sources. [ABSTRACT FROM AUTHOR]

An improved finite element modeling method is developed for isotropic curvilinearly stiffened plates under a thermal environment. The existing modeling method for curvilinearly stiffened plates avoids the difficulty of node overlap, which is suitable for plates with different thicknesses. By introducing the influence of temperature on material parameters and thermal stress on additional stiffness, the existing method is improved and extended to the study of thermodynamics. The proposed method is verified by modal test at normal temperature and commercial finite element software at the thermal environment. The variation of dynamic characteristics with temperature under different boundary conditions was studied. Results show that when the boundary conditions are asymmetric, the influence of temperature on the thermal mode shape is more significant than the case of symmetrical. [ABSTRACT FROM AUTHOR]

In this study, atmospheric bioaerosol particles were collected from March to December 2015 in the coastal region of Qingdao. The dominant fungi were identified, and the concentrations and size distributions of bacteria, total fungi and dominant fungi were measured. The most dominant fungal taxon was Cladosporium, followed by Alternaria, Penicillium and Aspergillus. The concentrations of fungi showed significant seasonal variation (p < 0.05) and peaked in summer, while bacterial concentrations peaked in autumn without significant seasonal differences. The particle size of fungi showed a similar normal distribution, peaking at 2.1 to 3.3 μm, while that of bacteria presented a skewed distribution pattern with a peak at > 7.0 μm. The size patterns of the four dominant fungi were distinct due to their respective properties. With correlation analysis, we found PM10, CO and NO2 were positively associated with the bacterial concentration. The factors correlated with fungal concentrations included temperature, relative humidity, CO, NO2, SO2 and O3. The results of RDA showed that the most important meteorological factors affecting the microorganism species composition were temperature and relative humidity, and the dominant air pollutants were SO2, CO and O3. We selected related parameters to conduct multiple linear regression analysis to explore the synergistic effects on a given microorganism. The contribution to the rate of changes in bacterial and fungal concentrations caused by related factors was less than 30%, indicating that the sources and community changes had a great influence on bioaerosol concentrations. The more detailed the classification of microorganisms is, the more specific correlation information may be obtained through our analysis method. [ABSTRACT FROM AUTHOR]

Nonylphenols (NPs) are persistent organic pollutants (POPs) with estrogenic properties that can perform endocrine-disrupting activities. By using high-concentration NP as environmental selection pressure, one NP biodegradation strain named NPF-4 was isolated and purified from estuary sediment of the Moshui River. It was identified as Penicillium simplicissimum (PS1) by appearance and 18S rDNA analysis. In different culture situations, the strain mass growth and biodegradation ability were evaluated. Within 4-n-nonylphenol (4-n-NP) initial concentration of 20 mg L, it could be degraded 53.76, 90.08, and 100.00 % at 3, 7, and 14 days, respectively. In feeding experiments, it showed that NPF-4 could use 4-n-NP as a sole carbon source. Based on seven products/intermediates detected with GC and LC-MS, a novel biopathway for 4-n-NP biodegradation was proposed, in which sequential hydroxylation, oxidation, and decarboxylation at terminal β-C atom may occur for 4-n-NP detoxification, even complete mineralization in the end. [ABSTRACT FROM AUTHOR]

Artificial upwelling, as a geoengineering tool, has received worldwide attention because it may actualize ocean fertilization in a sustainable way, which could potentially alleviate the pressures on the fish stocks and human-driven climate change in the ocean. We reviewed the current knowledge on the development of an artificial upwelling system and its potential environmental effects. Special attention was given to the research progress on the air-lift concept artificial upwelling by Zhejiang University. The research on artificial upwelling over the past few decades has generated a range of devices that have been successfully applied in the field for months. Based on field experiments and the associated modeling results, part of them reported positive effects on increasing primary production and enhancing CO sequestration. However, as a significant disturbance to the environment, especially for large-scale applications, the uncertainties related to the potential effects on ecosystem remain unsolved. Zhejiang University has overcome the technical challenges in designing and fabricating a robust and high efficiency artificial upwelling device which has been examined in two field experiments in Qiandao Lake and one sea trial in the East China Sea. It was investigated that cold and hypoxic deep ocean water (DOW) could be uplifted to the euphotic layer, which could potentially change the nutrient distribution and adjust the N/P ratio. Both simulation and field experiments results confirmed that utilizing self-powered energy to inject compressed air to uplift DOW was a valid and efficient method. Therefore, further field-based research on artificial upwelling, especially for long-term field research is required to test the scientific hypothesis. [ABSTRACT FROM AUTHOR]

This paper presents a new concept of multi-axis wave energy converter (WEC), which can capture wave energy from multiple directions of motion. It describes the modelling of the multi-axis WEC and presents the results of laboratory experiments on the power capture of the multi-axis WEC in a wave tank subjected to synthesized scaled sea waves. The experiments investigate the influence of parameters such as buoy structure, damping and inertia modification (ballasting) on the hydrodynamic performance. The experimental results indicate that the multi-axis WEC yields very good performance under a variety of wave conditions. It is also demonstrated that, by utilizing more than one direction of motion, the multi-axis WEC proves capable of supplying more power than a single-axis WEC. This work constitutes a preliminary step towards the development of an advanced concept of WEC. [ABSTRACT FROM AUTHOR]

Two new indole alkaloids, 2-(3,3-dimethylprop-1-ene)-costaclavine ( 1) and 2-(3,3-dimethylprop-1-ene)-epicostaclavine ( 2), together with the known compounds costaclavine ( 3), fumgaclavine A ( 4) and C ( 5), were isolated from the marine-derived fungus Aspergillus fumigatus. The planar structures of the two new compounds were elucidated on the basis of chemical and physicochemical evidence including MS, UV, IR and NMR spectra. Their stereochemistry was studied by NOESY, H-H coupling constant and CD spectra. The compounds 1, 2, 3 and 5 showed weak cytotoxicity against a mouse leukemia cell line (P388). [ABSTRACT FROM AUTHOR]

Abstracts are not published in this journal [ABSTRACT FROM AUTHOR]

Cultural situation generally played a crucial role on biodegradation mechanism establishment of pollutant. Extensive studies had focused on the optimization of cultivation environment based on in situ conditions. However, there were still few reports on the effects of artificial control on microbial growth and degradation. In this work, the relationship of biomass, situation, and artificial control was explored through the biodegradation of nonylphenols as standard containments by four trains named A. niger, A. terreus SHPP01, A. terreus NIH2624, and T. aff. harzianum from the estuary sediment of Jiaozhou Bay. Various culture conditions covering mineral salt medium, glucose synergistic medium, and carbon rich complex medium had been used to quest the relationship. As a conclusion, different strains usually showed different mechanisms within the same media. The correlation ship between biomass and degradation and removal rate was positive, and the natural medium was usually the best choice for microbial study in situ simulation. Hence, our study provided a valuable reference for the realization of more efficient and rapid biodegradation of pollutants. [ABSTRACT FROM AUTHOR]

Abstracts are not published in this journal [ABSTRACT FROM AUTHOR]