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Safe trapping of radioactive nuclear waste such as 137Cs has become a grim issue with the popularity of nuclear power and the growing yield of nuclear waste. To address this intractable problem, pollucite has been screened out as an ideal material for the long-term storage of 137Cs due to its low leaching rate and good chemical and thermal stability. With an effort to further enhance its immobilization capability and practical values, we herein report a robust route to prepare pollucite from ion-doped geopolymer at low temperature (≤1000 °C), achieving high Cs content (33.37 wt.%) and the lowest leaching rate of Cs (2.51 × 10−4 g m-2 d-1) to date. Meanwhile, the leaching mechanism of Cs in pollucite is revealed via leaching tests coupled with SEM-EDS analysis. Therefore, this contribution may provide an alternative route to preparing pollucite and open up new possibilities in the immobilization of 137Cs for real-world applications.

The fungus gnat is a major pest of chive in China. Its control has been relied heavily on the application of clothianidin. Due to the intensive application, its control efficacy become reduced. The present study was intended to evaluate co-drenching of clothianidin with hexaflumuron on absorption and dissipation of clothianidin in chive plants and soils and determine the effect of such application on control efficacies. Chive production fields in Guangdong and Hubei Provinces were drenched with clothianidin alone and a mixture of clothianidin and hexaflumuron at low application rates. Concentrations of clothianidin in chive plants and soils were analyzed by HPLC. Results showed that co-application had higher control efficacies against the fungus gnat than clothianidin alone. The co-application enhanced clothianidin absorption and dissipation and extended the half-lives of clothianidin in chive. It was likely that hexaflumuron protected chive roots from larva damage, and healthy roots absorbed more clothianidin, resulting in the extension of the half-lives. Additionally, the terminal residues of clothianidin in chive after 14 days of application were lower than the maximum residue limit in chive set by the Codex Alimentarius Commission. This study for the first time documented that co-application of clothianidin and hexaflumuron improved chive plants in absorption and dissipation of clothianidin and enhanced fungus gnat control efficacies.

Striped rice stem borer, Chilo suppressalis (Walker) and pink stem borer, Sesamia inferens (Walker) are two important pests, causing substantial yield loss in rice production. Application of conventional synthetic pesticides, such as suspension concentrates and water-dispersible granules, is a primary method for control of the two pests. Due to the flow of water in rice field, spray drift, and soil adsorption, applied such pesticides are often out of the target, resulting in low control efficacy, potential contamination of soil or surface water, and also threat to human health. Thus, there is an urgent need for developing environmentally friendly and highly targeted pesticide formulations to meet the challenges. The present study synthesized chlorantraniliprole loaded chitosan-alginate floating hydrogel microspheres (CCAM) through physical embedding, ionic crosslinking, and incorporation of citronellol as an oil phase. The morphology, particle size, entrapment efficiency, loading capacity, in vitro slow-release kinetics, and floating ability of the CCAM were tested in laboratory conditions. The CCAM and two commercial formulations (suspended and granulated) of chlorantraniliprole were respectively evaluated in two rice fields located in two provinces of China. The CCAM was able to float on the surface of rice field, gather around rice stems, and slowly release chlorantraniliprole, which resulted in significantly higher concentrations of chlorantraniliprole in rice stems and leaves for a prolonged time than suspended and granulated controls. The application of CCAM provided an on-target control of both striped stem borer and pink stem borer. Furthermore, CCAM application had very low residue of chlorantraniliprole in soils. As far as is known, this is the first report of chlorantraniliprole loaded on chitosan-alginate floating hydrogel microspheres for rice stem borer control. Our results indicate that the synthesized CCAM could potentially be used as a controlled-release product for effective control of the two rice pests, while reducing the residual chlorantraniliprole in the soil and avoiding pesticide drift.

CO2 geological sequestration in shale is a promising method to mitigate global warming caused by greenhouse gas emissions as well as to enhance the gas recovery to some degree, which effectively addresses the problems related to energy demand and climate change. With the data from the New Albany Shale in the Illinois Basin in the United States, the CMG-GEM simulator is applied to establish a numerical model to evaluate the feasibility of CO2 sequestration in shale gas reservoirs with potential enhanced gas recovery (EGR). To represent the matrix, natural fractures, and hydraulic fractures in shale gas reservoirs, a multicontinua porous medium model will be developed. Darcy’s and Forchheimer’s models and desorption-adsorption models with a mixing rule will be incorporated into the multicontinua numerical model to depict the three-stage flow mechanism, including convective gas flow mainly in fractures, dispersive gas transport in macropores, and CH4-CO2 competitive sorption phenomenon in micropores. With the established shale reservoir model, different CO2 injection schemes (continuous injection vs. pulse injection) for CO2 sequestration in shale gas reservoirs are investigated. Meanwhile, a sensitivity analysis of the reservoir permeability between the hydraulic fractures of production and injection wells is conducted to quantify its influence on reservoir performance. The permeability multipliers are 10, 100, and 1,000 for the sensitivity study. The results indicate that CO2 can be effectively sequestered in shale reservoirs. But the EGR of both injection schemes does not perform well as expected. In the field application, it is necessary to take the efficiency of supplemental energy utilization, the CO2 sequestration ratio, and the effect of injected CO2 on the purity of produced methane into consideration to design an optimal execution plan. The case with a permeability multiplier of 1,000 meets the demand for both CO2 sequestration and EGR, which indicates that a moderate secondary stimulation zone needs to be formed between the primary hydraulic fractures of injection and production wells to facilitate the efficient energy transfer between interwell as well as to prevent CO2 from channeling. To meet the demand for CO2 sequestration in shale gas reservoirs with EGR, advanced and effective fracking is essential.

Cell mass and viability are tightly linked to the productivity of fermentation processes. In 2nd generation lignocellulose-based media quantitative measurement of cell concentration is challenging because of particles, auto-fluorescence, and intrinsic colour and turbidity of the media. We systematically evaluated several methods for quantifying total and viable yeast cell concentrations to validate their use in lignocellulosic media. Several automated cell counting systems and stain-based viability tests had very limited applicability in such samples. In contrast, manual cell enumeration in a hemocytometer, plating and enumeration of colony forming units, qPCR, and in situ dielectric spectroscopy were further investigated. Parameter optimization to measurements in synthetic lignocellulosic media, which mimicked typical lignocellulosic fermentation conditions, resulted in statistically significant calibration models with good predictive capacity for these four methods. Manual enumeration of cells in a hemocytometer and of CFU were further validated for quantitative assessment of cell numbers in simultaneous saccharification and fermentation experiments on steam-exploded wheat straw. Furthermore, quantitative correlations could be established between these variables and in situ permittivity. In contrast, qPCR quantification suffered from inconsistent DNA extraction from the lignocellulosic slurries. Development of reliable and validated cell quantification methods and understanding their strengths and limitations in lignocellulosic contexts, will enable further development, optimization, and control of lignocellulose-based fermentation processes.

In this study a laboratory-scale sequencing batch bioreactor was constructed, using phenanthrene/pyrene as the sole carbon-source, to demonstrate the removal efficiencies of polycyclic aromatic hydrocarbons (PAHs) and the evolution process of a functional bacterial community. The removal rates were: COD, 51.4 to 76.3%; phenanthrene, 63.5 to 92.4%; and pyrene, 65.9 to 90.1%. Quantification analysis indicated that in sludge samples from the phenanthrene/pyrene degradation stage, the contents of 16S rRNA and ring-hydroxylating dioxygenase genes of Gram-positive and Gram-negative bacteria were 10-and 72-, 102- and 1152-, 31- and 905-fold higher, respectively, than those in seed sludge samples. Clone sequencing and evolution analysis showed that genera Comamonas, Pseudomonas, and Mycobacterium were distributed across all samples and were significant PAH-degrading populations, but some genera, such as Polaromonas and Nocardioides, were substantially enriched only when phenanthrene/pyrene was fed. Correspondingly, the functional genes nidA3, phnAc, and ndoC2 were distributed across all samples, whereas nagAc, pdoA2, and pdoA were enriched only when phenanthrene/pyrene was fed.

The occurrence of various antibiotics in wastewater treatment systems continues to arouse extensive attention. However, the effects of low concentration of antibiotics on wastewater treatment performance and the related functional bacteria, especially under long-term operation, remain largely unknown. In this study, a lab-scale anaerobic-aerobic system was established to evaluate the impacts of 5 mg l−1 tetracycline on the performance of a lab-scale wastewater treatment system and the abundance of the related functional bacteria. The results indicated that Tc exposure had little effect (p > 0.05) on the efficiency of COD removal during the whole period of 200 days, but significantly decreased ammonia removal (p

The antibacterial effects of phenyllactic acid (PLA) against Vibrio parahaemolyticus and its application on raw salmon fillets (RSF) were investigated in this study. The minimum inhibitory concentration (MIC) of PLA against V. parahaemolyticus was 3.2 mg/mL. Interestingly, PLA at sub-MIC (0.4 mg/mL) completely inactivated planktonic V. parahaemolyticus under saline condition. The influence of PLA on bacterial membrane and genomic DNA was explored to reveal its antibacterial mechanism. Although no obvious morphological changes were observed by scanning electron microscope, the permeability of bacterial membrane was increased and the leakage of potassium was detected under PLA stress. DNA interaction analysis illustrated that PLA was intercalative with genomic DNA, which might influence normal physiological functions of bacteria. Besides, PLA at sub-MIC could effectively inhibit the motility (i.e., swimming and swarming) of V. parahaemolyticus, thereby inhibiting its biofilm formation. The in vivo antibacterial tests confirmed that PLA at 8 MIC was capable of eliminating the contamination of V. parahaemolyticus on RSF thoroughly, while low concentration of PLA could also be used as an antibacterial agent to inhibit the growth of V. parahaemolyticus on RSF, suggesting that PLA was a promising candidate for the control of foodborne pathogens in chilled aquatic products.

The migration and transformation of sulfur is closely related to carbon sources. However, knowledge on the co-occurrence patterns of sulfur-related bacteria and other carbon-consuming microorganisms in constructed wetlands (CWs) is limited. In this study, CWs with intertidal wetland sediments (IWS), as microbial inoculant, was constructed to investigate the sulfate and chemical oxygen demand (COD) removal rates, microbial community composition, and co-occurrence network. IWS-enhanced CWs planted with Phragmites australis (PA+) and unplanted ones (CT+) were set up with controls (PA and CT). Results showed that the sulfate removal rate was higher in PA+ (60.60% ± 0.80%) than PA (44.64% ± 2.72%). The sulfate removal rate decreased and that of COD increased in PA+ and PA when the influent sulfate concentrations were raised. Microbial analysis indicated that the numbers of sulfate-reducing bacteria (SRB), sulfur oxidizing bacteria (SOB), and carbon-degrading bacteria improved the removal efficiency of sulfate in PA+ and CT+. The microbial topological pattern revealed that the exchange of matter, energy, and information by microorganisms in PA+ and CT+ was faster than that in PA and CT. The co-occurrence network analysis indicated that SRB (e.g., unclassified Desulfuromonadaceae) harbored negative correlations with denitrifying bacteria (e.g., Thauera, Flavobacterium, and unclassified Burkholderiaceae) because of electron donor competition. However, Flavobacterium and Thauera could cooperate to denitrify through different electron donors to avoid competition. Moreover, Pseudomonas and Amaricoccus had cross-feeding and cooperation in the network when carbon was restricted.

Using plant essential oil instead of chemical pesticides to control melon fly (Bactrocera cucurbitae (Coquillett)) is still a great challenge in agricultural practices, which must effectively slow down the volatility rate of plant essential oil. In this study, citral as a natural plant essential oil was blended with environmentally friendly castor oil based waterborne polyurethane (PU). The interaction, chemical resistance, adhesion property and sustained release behavior of the composites with different citral content were clarified, and the efficacies against the melon fly under field conditions were explored. The results indicated that the composites prepared exhibited excellent adhesion behavior on bitter gourds (Momordica charantia L.) even under rainfall washing, meanwhile the chemical resistance of composites could be tailored via controlling citral content. Low citral content composite films could be washed off by alcohol without worrying about the safety of that on crops. The composite prepared exhibited long-lasting repellent behavior against melon fly. The composite can be prepared via a simple technology and low cost, which has great value for plant essential oil applied in agriculture and can provide a new approach for melon fly control.

This study investigated the ability of dual crosslinked interpenetrating polymer network (IPN) blend beads (DIN:SA/PVA-beads), composed of sodium alginate (SA) and poly (vinyl alcohol) (PVA), as a base-triggered carrier for the controlled release of dinotefuran (DIN) in Spodoptera litera midgut. The blend beads were characterized for morphology, encapsulation efficiency, swelling degree, and in vitro release of the blend beads were characterized. The results revealed that the double-crosslinked gel beads had a tightly interpenetrating network structure and exhibited a satisfactory embedding effect for DIN. The maximum of the DIN loading capacity was approximately 1.01%, with a high encapsulation efficiency of 83.19%. The triggered release of DIN from the blend beads was studied in deionized water (pH 3.0–11.0) via high-performance liquid chromatography (HPLC); it was found that the release rate was higher in alkaline pH conditions than in acidic and neutral conditions. An in vivo dynamics and degradation study also demonstrated that the excellent release characteristics of DIN:SA/PVA-beads in the midgut of S. litera. This study provides a promising controlled-release form of dinotefuran that is more effective and can be used for the targeted control of pests with alkaline midgut.

Background Monolepta hieroglyphica (Motschulsky) is a primary pest of maize. The effect of dimethoate on controlling a M. hieroglyphica infestation was studied using drip irrigation. Field trials were conducted to determine the most effective application rate and water volume for dimethoate treatment in arid and semi-arid regions. The absorption, distribution and dissipation of dimethoate in maize and soil were examined. Results Field trials showed that dimethoate at a rate of 2.70 kg a.i. ha-1 and water volume of 200 m3 ha-1 was the most effective treatment for controlling M. hieroglyphica. Dimethoate via drip irrigation showed longer persistence than dimethoate applied via artificial or unmanned air vehicle spraying. Different parts of the maize plant had a hysteresis effect on dimethoate absorption. Dimethoate was absorbed from the roots, transported upward, and enriched in the leaf. Dimethoate was mainly concentrated within a certain range near the emitter after drip irrigation. Terminal residues of dimethoate in maize grain were below detectable levels 42 days after treatment. Conclusions Dimethoate treatment via drip irrigation can control M. hieroglyphica infestation on maize. Results showed that dimethoate is safe for maize and the environment. This study provides guidance for the application of pesticides in arid and semi-arid areas. © 2019 Society of Chemical Industry.

The efficacy and mode of action of biodegradable chitosan (CS) and carboxymethyl chitosan (CMCS) organic polymer nanoparticles (NPs) on insects were studied. The prepared CS/CMCS-NPs were spherical with a particle size of 142.1 ± 2.0 nm. The swelling test showed that they were pH-sensitive, and the swelling rate was 554 % at pH 4.5. It was found that CS/CMCS-NPs had insecticidal efficacy against red fire ants (S. invicta). The mortality of red fire ants on the 6th day after treatment with 0.2 % and 0.06 % CS/CMCS-NPs suspensions was 98.33 ± 1.67 % and 48.33 ± 3.33 %, respectively. After CS/CMCS-NPs treatment, the food intake, growth, and development of red fire ants were inhibited; the midgut was significantly expanded; and the activity of digestive enzymes in the midgut was decreased. Our findings suggest that CS/CMCS-NPs mainly inhibited the digestion function of the midgut, leading to the death of red fire ants.

ER stress has close relation with various metabolic diseases including obesity and insulin resistance, and could result in the abnormal production of ROS including O2-. Real-time and in situ detection of endogenous O2- in ER is vitally important for revealing the physiological roles of O2- during ER stress. Herein, we present an ER-specific two-photon probe (ER-Rs) for the detection of endogenous O2- in living cells and zebrafishes. The probe ER-Rs employed triflate as the response site for O2-, and used p-methylsulfonamide as the ER-specific moiety. In response to O2-, the triflate group of the probe ER-Rs was transformed to hydroxyl and the turn-on fluorescence was produced. The probe ER-Rs displayed highly sensitive and selective response to O2-, and could be employed as an ER-specific two-photon probe for the visualization of endogenous O2- in live cells, tissues and zebrafishes.

Excessive production and utilization of nanoparticles (NPs) at industrial and household levels releases substantial quantities of NPs into the environment. These can be harmful to different types of organisms and cause adverse effects on ecosystems. Purchased TiO2 and ZnO NPs were characterized via XRD, XPS, FESEM, and Zeta potential. This study elucidates how multidrug resistant Escherichia coli LM13, which was recovered from livestock manure, counteracts the antibacterial activities of TiO2 and ZnO NPs to survive in the environment. E. coli ATCC25922, which is susceptible to antibiotics, was used as control. A dose-response experiment showed that the antibacterial activity of TiO2 was lower than that of ZnO NPs and, LM13 was more resistant to NPs than ATCC25922. An AcrAB-TolC efflux pump along with its regulation genes helped LM13 to minimize NP toxicity. Flow cytometry findings also indicated that the intensity of the side-scatter light parameter increased with TiO2 and ZnO NPs in a dose dependent manner, suggesting NP uptake by the both strains. The generation of reactive oxygen species in LM13 was several-fold lower than in ATCC25922, suggesting that reactive oxygen species mainly contribute to the toxicity mechanism. These results illustrate the necessity to evaluate the impacts of NPs on the survival capacity of bacteria and on the resistance genes in bacteria with higher NP resistance than NP susceptible bacteria.

The denitrifying phosphorus-accumulating organisms (DPAOs) were extensively focused in the past years due to their high efficiencies in simultaneous removal of phosphorus (P) and nitrogen (N) in wastewater treatment. However, it is not clear how this group of bacteria evolve along with the operation process of a specific wastewater treatment system. Here, it is firstly investigated that the effects of simultaneous variations in chemical oxygen demand (COD), P, and N concentrations on enhanced biological phosphorus removal and phosphorus accumulating (PAOs) and DPAOs in an anaerobic–aerobic–anoxicSBR. The results showed that P and N removal ratios were 83.10 ± 6.72% and 64.21 ± 7.10%, 90.38 ± 3.63% and 84.52 ± 4.91%, 78.82 ± 8.78% and 78.71 ± 3.98% corresponding to the SBR operation process of phases I, II and III respectively. The potential PAOs and DPAOs (such as genera Thauera and Dechloromonas) were clearly enriched at different operation phases, especially at phase II. Q-PCR and correlation analysis indicated that phosphorus accumulating-related ppk1 genes and denitrifying-related genes coexisted in the SBR and their contents varied with influent COD, P, and N concentrations. Moreover, ppk1 genes clade IIC/IIF and denitrifying-related genes nirK were highly correlated in the SBR. Therefore, simultaneous variations in nutrient concentrations significantly affected the abundance and distribution of functional bacteria and genes related to P and N removal. The results are valuable in N and P removal of practical wastewater treatment engineering

Fresh fish are highly perishable because their high content of protein and unsaturated fatty acids are easily oxidized and/or degraded under the influence of bacteria and the external environment. In this study, four natural preservatives (phenyllactic acid, kojic acid, tea polyphenols and thymol) were initially screened for antimicrobial activity against spoilage bacteria commonly found in fish by in vitro antibacterial tests. The results suggested that kojic acid (KA) and tea polyphenols (TP) exhibited a strong synergistic antibacterial effect against spoilage bacteria. Hence, the effects of KA and/or TP on the preservation of refrigerated sea bass (Lateolabrax japonicus) fillets after soaking treatments were determined. Changes in physicochemical parameters, indexes of fish freshness and microbial enumeration were examined. KA, TP and KA-TP treatments were effective in inhibiting bacterial growth and delaying lipid oxidation in fish flesh, resulting in lower TVB-N and TBARS than the control. Meanwhile, the freshness and physical qualities (color and texture) of fish fillets were also stabilized by the three treatments. Moreover, the KA-TP treatment showed the best effect on refrigerated fish preservation among the three treatments and extended the shelf-life by 5–6 days, suggesting that KA-TP have the potential to become a compound preservative for aquatic products.

Traditional pesticide formulations show poor utilization and environmental safety due to their low foliage adhesion and large auxiliaries. In this study, a novel and environment-friendly indoxacarb formulation was prepared to improve the pesticide&rsquo, s utilization rate, target control characteristics and ecological security. Indoxacarb-loaded waterborne polyurethane&ndash, sodium alginate (PU/SA) nanoemulsions with film forming properties, alkaline responsive release, high effectiveness against Spodoptera litura, and reduced acute contact toxicity for nontarget organisms were successfully prepared. The colloidal properties, swelling and release behaviors, leaf adhesion, degradation dynamics and bioactivity assay of the indoxacarb-loaded PU/SA nanoemulsions were determined. Results showed that the obtained indoxacarb-loaded microcapsule particulates were approximately 57 nm in diameter, electronegative &minus, 45.9 mV, and uniformly dispersed in the nanoemulsions. The dried latex films of PU/SA in the alkaline environment revealed better responsive swelling and release characteristics than those in acidic and neutral conditions. Compared with a commercial emulsifiable concentrate, the indoxacarb-loaded PU/SA nanoemulsions were useful for the targeted control of S. litura, which have alkaline gut and showed reduced acute contact toxicity to Harmonia axyridia. Furthermore, the PU/SA formulation had better foliage adhesion and indicated the property of controlled-release and a persistent effect.

Lipid rafts, distinct liquid-ordered plasma membrane microdomains, have been shown to regulate tumor cell migration by internalizing and recycling cell-surface proteins. The present study reports that lipid rafts are a prerequisite for lamellipodia formation, which is the first step in the processes of tumor cell migration. The results from the wound-healing assay and immunostaining indicated that lipid rafts were asymmetrically distributed to the leading edge of migrating melanoma A375 cells during lamellipodia formation. When the integrity of lipids rafts was disrupted, lamellipodia formation was inhibited. The investigation of possible molecular mechanisms indicated that lipid rafts recruited β1 and β3 integrins, two important adhesion proteins for cell migration, to the lamellipodia. However, the different distribution characteristics of β1 and β3 integrins implied disparate functions in lamellipodia formation. Further immunostaining experiments showed that the actin cytoskeleton was responsible for lipid raft-mediated β1 and β3 integrin distribution in the lamellipodia. Together, these findings provide novel insights into the regulation of lipid rafts in lamellipodia formation, and suggest that lipid rafts may be novel and attractive targets for cancer therapy.

Background Considerable progress is being made in ethanol production from lignocellulosic feedstocks by fermentation, but negative effects of inhibitors on fermenting microorganisms are still challenging. Feeding preadapted cells has shown positive effects by sustaining fermentation in high-gravity simultaneous saccharification and co-fermentation (SSCF). Loss of cell viability has been reported in several SSCF studies on different substrates and seems to be the main reason for the declining ethanol production toward the end of the process. Here, we investigate how the combination of yeast preadaptation and feeding, cell flocculation, and temperature reduction improves the cell viability in SSCF of steam pretreated wheat straw. Results More than 50% cell viability was lost during the first 24 h of high-gravity SSCF. No beneficial effects of adding selected nutrients were observed in shake flask SSCF. Ethanol concentrations greater than 50 g L−1 led to significant loss of viability and prevented further fermentation in SSCF. The benefits of feeding preadapted yeast cells were marginal at later stages of SSCF. Yeast flocculation did not improve the viability but simplified cell harvest and improved the feasibility of the cell feeding strategy in demo scale. Cultivation at 30 °C instead of 35 °C increased cell survival significantly on solid media containing ethanol and inhibitors. Similarly, in multifeed SSCF, cells maintained the viability and fermentation capacity when the temperature was reduced from 35 to 30 °C during the process, but hydrolysis yields were compromised. By combining the yeast feeding and temperature change, an ethanol concentration of 65 g L−1, equivalent to 70% of the theoretical yield, was obtained in multifeed SSCF on pretreated wheat straw. In demo scale, the process with flocculating yeast and temperature profile resulted in 5% (w/w) ethanol, equivalent to 53% of the theoretical yield. Conclusions Multifeed SSCF was further developed by means of a flocculating yeast and a temperature-reduction profile. Ethanol toxicity is intensified in the presence of lignocellulosic inhibitors at temperatures that are beneficial to hydrolysis in high-gravity SSCF. The counteracting effects of temperature on cell viability and hydrolysis call for more tolerant microorganisms, enzyme systems with lower temperature optimum, or full optimization of the multifeed strategy with temperature profile. Electronic supplementary material The online version of this article (doi:10.1186/s13068-017-0893-y) contains supplementary material, which is available to authorized users.

Background The most advanced strains of xylose-fermenting Saccharomyces cerevisiae still utilize xylose far less efficiently than glucose, despite the extensive metabolic and evolutionary engineering applied in their development. Systematic comparison of strains across literature is difficult due to widely varying conditions used for determining key physiological parameters. Here, we evaluate an industrial and a laboratory S. cerevisiae strain, which has the assimilation of xylose via xylitol in common, but differ fundamentally in the history of their adaptive laboratory evolution development, and in the cofactor specificity of the xylose reductase (XR) and xylitol dehydrogenase (XDH). Results In xylose and mixed glucose–xylose shaken bottle fermentations, with and without addition of inhibitor-rich wheat straw hydrolyzate, the specific xylose uptake rate of KE6-12.A (0.27–1.08 g gCDW−1 h−1) was 1.1 to twofold higher than that of IBB10B05 (0.10–0.82 g gCDW−1 h−1). KE6-12.A further showed a 1.1 to ninefold higher glycerol yield (0.08–0.15 g g−1) than IBB10B05 (0.01–0.09 g g−1). However, the ethanol yield (0.30–0.40 g g−1), xylitol yield (0.08–0.26 g g−1), and maximum specific growth rate (0.04–0.27 h−1) were in close range for both strains. The robustness of flocculating variants of KE6-12.A (KE-Flow) and IBB10B05 (B-Flow) was analyzed in high-gravity simultaneous saccharification and co-fermentation. As in shaken bottles, KE-Flow showed faster xylose conversion and higher glycerol formation than B-Flow, but final ethanol titres (61 g L−1) and cell viability were again comparable for both strains. Conclusions Individual specific traits, elicited by the engineering strategy, can affect global physiological parameters of S. cerevisiae in different and, sometimes, unpredictable ways. The industrial strain background and prolonged evolution history in KE6-12.A improved the specific xylose uptake rate more substantially than the superior XR, XDH, and xylulokinase activities were able to elicit in IBB10B05. Use of an engineered XR/XDH pathway in IBB10B05 resulted in a lower glycerol rather than a lower xylitol yield. However, the strain development programs were remarkably convergent in terms of the achieved overall strain performance. This highlights the importance of comparative strain evaluation to advance the engineering strategies for next-generation S. cerevisiae strain development. Electronic supplementary material The online version of this article (doi:10.1186/s13068-017-0887-9) contains supplementary material, which is available to authorized users.

Background High content of water-insoluble solids (WIS) is required for simultaneous saccharification and co-fermentation (SSCF) operations to reach the high ethanol concentrations that meet the techno-economic requirements of industrial-scale production. The fundamental challenges of such processes are related to the high viscosity and inhibitor contents of the medium. Poor mass transfer and inhibition of the yeast lead to decreased ethanol yield, titre and productivity. In the present work, high-solid SSCF of pre-treated wheat straw was carried out by multi-feed SSCF which is a fed-batch process with additions of substrate, enzymes and cells, integrated with yeast propagation and adaptation on the pre-treatment liquor. The combined feeding strategies were systematically compared and optimized using experiments and simulations. Results For high-solid SSCF process of SO2-catalyzed steam pre-treated wheat straw, the boosted solubilisation of WIS achieved by having all enzyme loaded at the beginning of the process is crucial for increased rates of both enzymatic hydrolysis and SSCF. A kinetic model was adapted to simulate the release of sugars during separate hydrolysis as well as during SSCF. Feeding of solid substrate to reach the instantaneous WIS content of 13 % (w/w) was carried out when 60 % of the cellulose was hydrolysed, according to simulation results. With this approach, accumulated WIS additions reached more than 20 % (w/w) without encountering mixing problems in a standard bioreactor. Feeding fresh cells to the SSCF reactor maintained the fermentation activity, which otherwise ceased when the ethanol concentration reached 40–45 g L−1. In lab scale, the optimized multi-feed SSCF produced 57 g L−1 ethanol in 72 h. The process was reproducible and resulted in 52 g L−1 ethanol in 10 m3 scale at the SP Biorefinery Demo Plant. Conclusions SSCF of WIS content up to 22 % (w/w) is reproducible and scalable with the multi-feed SSCF configuration and model-aided process design. For simultaneous saccharification and fermentation, the overall efficiency relies on balanced rates of substrate feeding and conversion. Multi-feed SSCF provides the possibilities to balance interdependent rates by systematic optimization of the feeding strategies. The optimization routine presented in this work can easily be adapted for optimization of other lignocellulose-based fermentation systems. Electronic supplementary material The online version of this article (doi:10.1186/s13068-016-0500-7) contains supplementary material, which is available to authorized users.

Here, we prepared several derivatives of chitin and detected their activities in blocking P-selectin-mediated inflammation cell (HL60 cell) adhesion. Our results showed that 6-O-sulfated chitin (6S-chitin) and 6-O-sulfated carboxymethyl chitin (6SCM-chitin), but not 6-O-carboxymethyl chitin (6CM-chitin), dramatically reduced P-selectin-mediated HL60 cell adhesion under static and flow conditions. Interestingly, 6SCM-chitin demonstrated stronger activity than 6S-chitin. Because 6SCM-chitin is obtained by the introduction of carboxymethyl group to C6 of 6S-chitin, we speculate that the synergy of sulfate and carboxymethyl groups in chitin might be indispensable for blocking P-selectin-mediated cell adhesion. The spacing arrangement of sulfate groups and carboxymethyl groups of modified chitin most probably meets the requirement of recognition by P-selectin. Our findings have a potential value for exploiting the biological use of chitin, especially for designing anti-inflammatory agents targeting P-selectin.

The diagenesis and porosity evolution in the deep 3rd member of Shahejie Formation of the Wendong Oilfield was analyzed using thin-sections, casting thin-sections, X-ray diffractometry, scanning electron micrograph observations, and other data. Sandstone reservoirs are currently at the late diagenetic period. Pores consist of primary pores and the inter-granular dissolved and intra-granular dissolved pores of feldspar, debris and carbonate cements. Physical properties are mainly controlled by carbonate cementation and dissolution, and distribution of abnormally high fluid pressure. The evolution of porosity parameters shows that primary porosity is 36.75%, the porosity loss rate is 40.49% during the process of mechanic compaction, the porosity loss rate is 37.25% during the process of cementation and metasomasis, and the porosity increase rate is 17.88% during the process of dissolution. The proportion of primary porosity is 55.03%, and that of the secondary porosity is 44.97%. The error rate in the quantitative study of porosity is 0.96%, and the main influencing factor of the error rate is sorting coefficient of detrital rock (S0). Key words: deep reservoir, Dongpu Sag, Wendong Oilfield, porosity evolution model, secondary pore

Selectin-mediated leukocyte initial attachment and rolling over vessel endothelial surface are crucial steps for inflammatory responses. As P-selectin is a promising target for anti-inflammation therapeutic strategy, recent works have focused on searching for more potent and non-toxic P-selectin antagonists among various natural carbohydrate products. Here, we isolated three water-soluble polysaccharide fractions (PPS-1, PPS-2 and PPS-3) from the roots of Physalis alkekengi by DEAE-cellulose and Sephacryl S-200 chromatography. Their physicochemical and structural characterizations were determined by chemical methods, GC (gas chromatography), HPLC (high performance liquid chromatography), FT-IR (Fourier transform infrared spectrometry), partial acid hydrolysis, methylation and GC-MS (gas chromatography-mass spectrometry) analyses. The inhibitory capacity of the polysaccharide fractions in P-selectin-mediated leukocyte adhesion was evaluated by flow cytometric, static adhesion and laminar flow assays. Results showed that different polysaccharide fractions possess distinct physicochemical and structural properties, including carbohydrate, protein and uronic acid contents, molecular weight, monosaccharide composition and glycosidic linkage type. Among the polysaccharide fractions, PPS-2 could effectively block the interaction between P-selectin and its native ligand.

Vibrational Stark effect (VSE) spectroscopy was used to measure the electrostatic fields present at the interface of the human guanosine triphosphatase (GTPase) Ras docked with the Ras binding domain (RBD) of the protein kinase Raf. Nine amino acids located on the surface of Raf were selected for labeling with a nitrile vibrational probe. Eight of the probe locations were situated along the interface of Ras and Raf, and one probe was 2 nm away on the opposite side of Raf. Vibrational frequencies of the nine Raf nitrile probes were compared both in the monomeric, solvated protein and when docked with wild-type (WT) Ras to construct a comprehensive VSE map of the Ras–Raf interface. Molecular dynamics (MD) simulations employing an umbrella sampling strategy were used to generate a Boltzmann-weighted ensemble of nitrile positions in both the monomeric and docked complexes to determine the effect that docking has on probe location and orientation and to aid in the interpretation of VSE results. These results were compared to an identical study that was previously conducted on nine nitrile probes on the RBD of Ral guanidine dissociation stimulator (RalGDS) to make comparisons between the docked complexes formed when either of the two effectors bind to WT Ras. This comparison finds that there are three regions of conserved electrostatic fields that are formed upon docking of WT Ras with both downstream effectors. Conservation of this pattern in the docked complex then results in different binding orientations observed in otherwise structurally similar proteins. This work supports an electrostatic cause of the known binding tilt angle between the Ras–Raf and Ras–RalGDS complexes.

Excessive trafficking of leukocytes can lead to serious tissue injury. Here, four regioselectively sulfated chitosans were assessed as inhibitors of HL-60 leukocyte binding to P-selectin, by investigating their effect on leukocyte adhesion to CHO cells expressing human P-selectin under static and flow conditions. The results show that the sulfochitosans exhibit inhibitory activity in this general order: heparin > N-sulfated/6-O-sulfated chitosan ≥ 3-O,6-O-sulfated chitosan > 6-O-sulfated chitosan ≫ N-sulfated chitosan. This suggests that the sulfation of the double site in chitosan is essential for efficient inhibition of P-selectin-mediated HL-60 leukocyte adhesion and that such sulfochitosans may have potential as therapeutic agents against inflammatory disease.

We prepared chitosan sulfated derivatives to address the common structural requirement of the sulfate pattern to block P-selectin-mediated tumor cell adhesion. Our results indicate that 6-O-sulfation of chitosan is indispensable for inhibition of P-selectin binding to human melanoma A375 cells. Furthermore, additional N-sulfation or 3-O-sulfation dramatically enhanced the inhibitory activity of 6-O-sulfated chitosan, suggesting that efficient anti-P-selectin adhesion activity of sulfated saccharides requires the synergy of 6-O-sulation and N- or 3-O-sulfation in glucosamine units.

Nanoscale containers and devices fabrication and application are recently attracted much attention. The surface profiles of nanoscale patterns are very important for nanotechnology and nano-devices integration. Nanopits and nanopores arrays are fabricated with focused ion beam tool. The morphologies of these small containers were explored by atomic force microscopy. The topography of every nanopattern looks like a volcano; and each nanopit has a V-shaped cross section with a pronounced ring-shaped structure that surrounds the crater. The main reason of this protruded ring structure is the swelling of the substrate due to amorphization and it is the inherent shape obtained by single-pass FIB milling. In this fabricating case, the redeposition effect is minor. The atomic force microscopy results of the nanopits rim morphologies are helpful to the micro- and nanoscale devices integration.