Search

Self-germinated seedlings of Citrus sinensis and C. grandis were supplied with nutrient solution with 0 mM AlCl(3)·6H(2)O (control, −Al) or 1 mM AlCl(3)·6H(2)O (+Al) for 18 weeks. The DW (Dry weights) of leaf, stem, shoot and the whole plant of C. grandis were decreased and the ratio of root DW to shoot DW in C. grandis were increased by Al, whereas these parameters of C. sinensis were not changed by Al. Al treatment dramatically decreased the sulfur (S) content in C. grandis roots and the phosphorus (P) content in both C. sinensis and C. grandis roots. More Al was transported to shoots and leaves in C. grandis than in C. sinensis under Al treatment. Al treatment has more adverse effects on C. grandis than on C. sinensis, as revealed by the higher production of superoxide anion (O(2)(·−)), H(2)O(2) and thiobarbituric acid reactive substace (TBARS) content in C. grandis roots. Via the Illumina sequencing technique, we successfully identified and quantified 12 and 16 differentially expressed miRNAs responding to Al stress in C. sinensis and C. grandis roots, respectively. The possible mechanism underlying different Al tolerance of C. sinensis and C. grandis were summarized as having following aspects: (a) enhancement of adventitious and lateral root development (miR160); (b) up-regulation of stress and signaling transduction related genes, such as SGT1, PLC and AAO (miR477, miR397 and miR398); (c) enhancement of citrate secretion (miR3627); (d) more flexible control of alternative glycolysis pathway and TCA cycle (miR3627 and miR482); (e) up-regulation of S-metabolism (miR172); (f) more flexible control of miRNA metabolism. For the first time, we showed that root development (miR160) and cell wall components (cas-miR5139, csi-miR12105) may play crucial roles in Al tolerance in citrus plants. In conclusion, our study provided a comprehensive profile of differentially expressed miRNAs in response to Al stress between two citrus plants differing in Al tolerance which further enriched our understanding of the molecular mechanism underlying Al tolerance in plants. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s12298-020-00895-y) contains supplementary material, which is available to authorized users.

Recently, lightweight and highly efficient electromagnetic interference (EMI) shielding composites are crucial but changing for the development of modern electronics and telecommunication. Here, a novel polyhedral Co/C particle embedded carbon nanofiber (CNF@Co/C) aerogels were synthesized via pyrolysis of bacterial cellulose wired zeolitic imidazolate frameworks-67 (ZIF-67) aerogel under argon. The flexible CNF@Co/C aerogels exhibit a high EMI shielding effectiveness (SE) is approaching 56.07 dB at a density of only 0.023 g cm−3 in the X band, and the average absorption coefficient is as high as 0.79, indicating 79% of electromagnetic (EM) waves are absorbed in shielding process. The remarkable performance results from the three-dimensional (3D) CNF-threaded porous structure with interconnected network and the magnetic Co/C particle strung by CNF, which contribute to a conduction loss and optimal impedance matching along with multiple polarization and strong magnetic loss. This work paves a promising way for the new generation of electronic device with lightweight and efficient EMI shielding.

Transition metal phosphides (TMPs) demonstrate great potential for hydrogen evolution reaction (HER) electrocatalysis, but their activities need further improvement. Herein we report a novel Au incorporation strategy to boost the HER catalytic performance of CoP. As a proof of concept, heterostructured Au/CoP nanoparticles dispersed on nitrogen-doped carbon with unique porosity, denoted as Au/CoP@NC-3, are synthesized by thermal treatment of Au-nanoparticle-incorporated ZIF-67 precursor. It shows excellent HER activity as well as good durability in acidic and alkaline condition, respectively, greatly outperforming its Au-free analogue, namely, CoP@NC. In-depth analysis suggests that the improved HER activity of Au/CoP@NC-3 is attributed to the presence of Au nanoparticles which enlarge the electrochemical active surface areas and adjust the electronic structure of active CoP species to enhance the water adsorption and optimize H adsorption for the accelerated HER process.

A quick, green, and sensitive method for chiral separation and determination of fluazifop-butyl enantiomers in tobacco and soil was established by ultra-performance convergence chromatography with tandem mass spectrometry (UPC2 -MS/MS). The baseline separation was obtained on an ACQUITY UPC2 Trefoil CEL2 column in 4 minutes with CO2 and methanol as mobile phase. Column temperature, auto back pressure regulator pressure (ABPR), and modifier solvent were optimized to obtain the best separation efficiency. Under the optimal conditions, the recoveries of both enantiomers were 82.8% to 99.5% with relative standard deviations (RSDs) less than 5.5% at three different concentration levels in two matrices. Good coefficients of determination (R2 ≥ 0.9976) were achieved over the concentration range of 10 to 500 ng/mL. The limits of detection (LODs) for all enantiomers in the two matrices varied from 1.6 to 2.1 μg/kg, and the limits of quantification (LOQs) did not exceed 7.0 μg/kg. The proposed method was then successfully applied to analyze authentic samples, confirming that it was a green, convenient, and reliable strategy for the analysis of fluazifop-butyl enantiomers in tobacco and soil.

Hemp (Cannabis sativa L.) cultivars Yunma 5 (YM5, fiber-type) and Bamahuoma (BM, seed-type) were seriously affected by salt-alkali stress during germination, while the knowledge about the salt tolerance during seedling stage is deficient. Here, responses of hemp (Cannabis sativa L.) seedlings of the cultivars YM5 and BM to the stress of different concentrations of NaCl and Na2CO3 were investigated to explore the salt tolerance of hemp. Results showed that the plant height, dry weight and root length of YM5 and BM seedlings gradually decreased as the concentration of NaCl or Na2CO3 increased. Although physiological indices such as EC (Electrical conductivity), SOD (Superoxide dismutase) and Pro (Proline) increased as the salt concentration increased, the increase extent was significantly greater in YM5 than in BM. Under the conditions of 100 and 200 mM NaCl, BM had greater dry weight and root length, and lower Pro content than YM5. However, under the stress of 100 and 200 mM Na2CO3, the opposite results were recorded, with the exception for lower chlorophyll content and higher SOD activity in BM than in YM5. These findings indicated that BM had a stronger NaCl tolerance than YM5. Moreover, morphological indices of the two cultivars under Na2CO3 stress were stunted more than under NaCl stress, and the seedlings died when Na2CO3 concentration increased up to 300 mM. Some up-regulation of salt-tolerant genes were observed in the two hemp cultivars, a higher expression under NaCl stress than under Na2CO3 stress, and a higher expression in YM5 than in BM were recorded. Findings from the study indicated that hemp seedling is more sensitive to Na2CO3 stress, and the tolerance of hemp to salt stress varies with salt type and salt concentration, although both cultivars can withstand moderate doses of NaCl and Na2CO3.

Multicyclic polymers including bicyclic and tetracyclic polymers were constructed by combining atom transfer radical polymerization (ATRP) and a photo-induced coupling reaction of anthryl groups. First, 4-arm and 8-arm star polystyrenes were synthesized by ATRP using tetrafunctional and octafunctional initiators, respectively. Subsequently, after two-step modification of Br-terminated 4-arm and 8-arm star polystyrenes, including azidation and copper-catalyzed azide–alkyne cycloaddition (CuAAC) reactions with prop-2-yn-1-yl anthracene-9-carboxylate, the precursors with anthryl end groups were obtained. Finally, the photo-induced coupling reaction was conducted upon irradiation at 365 nm in a diluted solution of 4-arm and 8-arm star precursors, to produce bicyclic and tetracyclic polymers, respectively. Besides, the multicyclic polymers can convert back to the original precursors after heating at 150 °C. 1H NMR, FT-IR, GPC and UV-vis analyses were carried out to verify the resultant multicyclic structures and the topological conversion between multicyclic polystyrenes and their precursors.

Multicyclic polystyrene (PS) with hyperbranched structure was constructed in an efficient way. First, a seesaw-type PS was synthesized via atom transfer radical polymerization (ATRP) using a Y-shaped ATRP initiator containing one hydroxyl at center and bromine at each end. After azidation, the anthryl and hydroxyl groups were introduced to the ends of the polymer chain by click reaction with a trifunctional molecule bearing alkynyl, hydroxyl, and anthryl groups (alkynyl-OH-ant). By irradiation with 365 nm UV light in a highly dilute condition, cyclic polymer with three hydroxyl groups (c-PS-(OH)3) can be obtained; then it was converted to a cyclic polymer containing three azides (c-PS-(N3)3) by bromination of the hydroxyl groups and azidation. This “A3” cyclic macromonomer was then used to construct hyperbranched multicyclic polymers via self-accelerating click reaction with sym-dibenzo-1,5-cyclooctadiene-3,7-diyne (DBA). The properties of obtained polymer were characterized by NMR, FT-IR, MALDI-TOF MS, a...

Ferroptosis is a new form of regulated cell death that shows promise for tumor treatment. Most current ferroptosis tumor therapies are based on the intrinsic pathological features of the malignancies, and it would be of clinical significance to develop ferroptosis-inducing strategies with improved tumor specificity and modulability. Here we report a polydopamine-based nanoplatform (FeII PDA@LAP-PEG-cRGD) for the efficient loading of Fe2+ and β-lapachone (LAP), which could readily initiate ferroptosis in tumor cells upon treatment with near-infrared light. PDA nanostructures could generate mild hyperthermia under NIR irritation and trigger the release of the ferroptosis-inducing Fe2+ ions. The NIR-actuated photothermal effect would also activate cellular heat shock response and upregulate the downstream NQO1 via HSP70/NQO1 axis to facilitate bioreduction of the concurrently released β-lapachone and enhance intracellular H2 O2 formation to promote the Fe2+ -mediated lipid peroxidation.

This work presents a simple, rapid and green chiral analysis method for five triazole fungicides (penconazole, tebuconazole, triadimefon, myclobutanil, and triadimenol) in tobacco, by which the samples were cleaned up by the novel pass-through solid phase extraction and subsequently the stereoisomers were separated and determined by the supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS). Optimized separation of the stereoisomers was achieved on an ACQUITY UPC2 Trefoil AMY 1 column within 6 min. Under fortified concentration levels of 0.1, 0.5 and 2.0 mg/kg, the mean recoveries were 82.8-106.6%, the intra-day relative standard deviations (RSDs) were 1.1-6.6%, and the inter-day RSDs were 2.5-5.6%. The correlation coefficient was greater than 0.9926 for all studied analytes within the range of 10-500 ng/mL. The limits of detection (LODs) for all stereoisomers ranged from 0.26 μg/kg to 3.24 μg/kg. The established method was subsequently successfully applied to analyze authentic samples, confirming that this method is a novel, rapid and environmentally friendly method for the stereoselective separation of triazole fungicides in tobacco.

Silicon carbide (SiC) devices have attracted much attention due to their superior characteristics of high blocking voltage, high frequency and high operating temperature. In recent years, with the continuous development of SiC device technology, domestic and foreign high-voltage SiC devices have made certain breakthroughs. In this paper, a 6.5kV/400A SiC module is prepared using the 6.5kV SiC MOSFET chip and 6.5kV SiC SBD chip independently developed by the research group. The on-resistance of the module is 20.8mΩ at a junction temperature of 150°C, and the drain leakage current is 146μA under a voltage of 6.5kV, indicating that the module has excellent conduction and blocking characteristics. The switching characteristics of the 6.5kV/400A SiC module are tested and evaluated based on high-voltage SiC dynamic test platform. At a junction temperature of 150°C, the turn-on energy is 714.2mJ, and the turn-off energy Eoff is 448mJ, compared with the Si IGBT module of the same voltage and current, the SiC module has faster switching speed, lower switching loss, and has obvious advantages in high-voltage and high-frequency applications.

N′-nitrosonornicotine (NNN) is one of the most prevalent and toxic tobacco-specific nitrosoamines. A chiral center at its 2′-position results in R and S enantiomers, the partial double bond character of the N N = O group also results in E and Z isomers, therefore, NNN can form a total of four absolute configurations (E-(R)-NNN, E-(S)-NNN, Z-(R)-NNN, and Z-(S)-NNN). This study investigated the resolution of R/S enantiomers and E/Z isomers of NNN by supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS). The baseline separation of E/Z-(R,S)-NNN isomers/enantiomers was accomplished through the optimization of chiral columns and co-solvents. Due to the lack of single standard of E/Z isomers, only R-NNN (sum of E-(R)-NNN and Z-(R)-NNN) and S-NNN (sum of E-(S)-NNN and Z-(S)-NNN) were further examined. Through the comprehensive optimization of SFC-MS/MS conditions, R-NNN and S-NNN were separated with a run time of 5 min, the developed method was validated, and its applicability to the determination of NNN enantiomers in burley tobacco samples was demonstrated. This study could be applied to preparative separation of single enantiomer and/or isomer of NNN, and could provide potential benefits to biologic activity studies on these enantiomers and isomers.

The trade-off between plant growth and resistance to herbivory is thought to be at least partly mediated by the interactions between jasmonates and gibberellins (GAs). Insect herbivory activates jasmonate biosynthesis and signaling, and plant growth is concomitantly inhibited. Whether or not the herbivory-induced jasmonates suppress the accumulation of GAs and thus reduce plant growth, and which jasmonates are functional in this process, remain unclear. In this study, we show that herbivory-induced stunted growth of Nicotiana attenuata was completely dependent on allene oxide cyclase (AOC) and coronatine insensitive1 (COI1), which encode a JA biosynthetic enzyme and the receptor, respectively, but only partially dependent on jasmonic acid-isoleucine conjugate (JA-Ile), the bioactive jasmonate. Quantification of GAs and exogenous treatments indicated that herbivory-induced growth inhibition was caused by GA4 deficiency, and that the reduction in GA4 accumulation was strongly associated with both decreased concentrations of GA biosynthetic gene transcripts and transcriptional activation of GA catabolic genes. We further show that JA-Ile only positively regulated the levels of GA catabolic genes, while the accumulation of GA biosynthetic gene transcripts was controlled by certain AOC-derived jasmonate(s) rather than by JA-Ile. This work sheds light on the mechanisms by which plants adapt to herbivory by using intricate phytohormone signaling and transcriptional regulatory networks.

We present studies of protein (insulin) efflux rates from nano-sized core–shell systems with a gelled core and a lipid bilayer (nanolipogels). The efflux control mechanism is the manipulation of mesh size, and we show that diffusion control via crosslinking is the dominant mechanism for efflux control. The concept is inspired by the macromolecular crowding effect in human cells, which may be considered as a physical network of undefined mesh size. Our bio-inspired system is made of chemically crosslinked water-swellable poly(ethylene glycol) diacrylate cores, whose mesh size can be manipulated to yield a quantifiable crowding effect that then leads to predictable release rates for biomacromolecules.

Citrus grandis seedlings were irrigated with nutrient solutions with four Al-P combinations [two Al levels (0 mM and 1.2 mM AlCl3·6H2O) × two P levels (0 μM and 200 μM KH2PO4)] for 18 weeks. Al dramatically inhibited the growth of C. grandis seedlings, as revealed by a decreased dry weight of roots and shoots. Elevating P level could ameliorate the Al-induced growth inhibition and organic acid (malate and citrate) secretion in C. grandis. Using a comparative proteomic approach revealed by the isobaric tags for relative and absolute quantification (iTRAQ) technique, 318 differentially abundant proteins (DAPs) were successfully identified and quantified in this study. The possible mechanisms underlying P-induced alleviation of Al toxicity in C. grandis were proposed. Furthermore, some DAPs, such as GLN phosphoribosyl pyrophosphate amidotransferase 2, ATP-dependent caseinolytic (Clp) protease/crotonase family protein, methionine-S-oxide reductase B2, ABC transporter I family member 17 and pyridoxal phosphate phosphatase, were reported for the first time to respond to Al stress in Citrus plants. Our study provides some proteomic details about the alleviative effects of P on Al toxicity in C. grandis, however, the exact function of the DAPs identified herein in response to Al tolerance in plants must be further investigated.

A deep understanding of the basic geologic characteristics of the fine-grained shale layers in the Paleogene 1st sub-member of Kong 2 Member (Ek21) in Cangdong sag, Bohai Bay Basin, is achieved through observation of 140 m continuous cores and systematic analysis of over 1 000 core samples from two wells. Basic geological conditions for shale oil accumulation are proposed based on the unconventional geological theory of oil and gas. The shale rock system mainly developed interbedded formation of felsic shale, calcareous and dolomitic shale and carbonates; high quality hydrocarbon source rock formed in the stable and closed environment is the material base for shale oil enrichment; intergranular pores in analcite, intercrystalline pores in dolomite and interlayer micro-fractures make tight carbonate, calcareous and dolomitic shale and felsic shale effective reservoirs, with brittle mineral content of more than 70%; high abundance laminated shale rock in the lower section of Ek21 is rich in shale oil, with a total thickness of 70 m, burial depth between 2 800 to 4 200 m, an average oil saturation of 50%, a sweet spot area of 260 km2 and predicted resources of over 5×108 t. Therefore, this area is a key replacement domain for oil exploration in the Kongdian Formation of the Cangdong sag. At present, the KN9 vertical well has a daily oil production of 29.6 t after fracturing with a 2 mm choke. A breakthrough of continental shale oil exploration in a lacustrine basin is expected to be achieved by volume fracturing in horizontal wells. Key words: shale oil, fine grained deposits, horizontal well, volume fracturing, shale reservoir sweet spot, Paleogene Kongdian Formation, Cangdong sag, Bohai Bay Basin

Benzo[a]pyrene (BaP) is considered as one of the most carcinogenic pollutants in cigarette smoke. The development of simple and sensitive BaP screening methods can help assess the risk of cigarette exposure to the human body rapidly. In this report, a rapid fluorescence immunoassay (RFIA) method for the detection of BaP is proposed, the core of which is the synthesis of bifunctional covalent antibody–DNA conjugates for target recognition and signal amplification. Based on the optimization of the SYBR Green I and PAH–BSA concentrations, as well as DNA–antibody immune complex's dilution in the RFIA system, a serial dilution of BaP was tested with this method. The results showed that the linear working range of the RFIA for BaP is 0.46 to 333 ng mL−1, which is much wider than traditional ELISA. The detection limit was 0.32 ng mL−1, which was more sensitive than other methods such as the redox-labeled electrochemical immunoassay method and the competitive piezoelectric biosensor. Then the cross-reactions (CR) of other PAHs in cigarette smoke were evaluated using this RFIA and found that the cross-reactions of naphthalene, anthracene, and pyrene were very low (

Shale gas is one of the most promising resources for unconventional natural gas. Several shale samples were collected from the Silurian Longmaxi Formation in the Yibin region, Sichuan Province, China. The basic geological parameters of the shale samples including total organic carbon, clay mineral content, and vitrinite reflectance were detected. Pore structure characteristics were analyzed with scanning electron microscopy, high-pressure mercury injection, and low-temperature nitrogen and carbon dioxide adsorption methods. Isothermal adsorption and desorption experiments were carried out using gravimetric methods. The isosteric heat of the shale adsorption was calculated using the isothermal adsorption experimental results. According to the experimental results, the shale samples have high maturity, low porosity and penetration. The surface morphological structures include organic pores, clay mineral pores, intergranular pores of authigenic minerals, dissolution pores and micro-cracks. Micropores comprised the majority of the developed pores in the shale samples and play a major role in adsorption processes. The adsorption and desorption results show that the adsorption amount of gas mainly undergoes a rapid increase phase, a slowly rising transition phase and a gentle phase, and desorption hysteresis generally occurs during gas desorption. Adsorption thermodynamics results show that the volume of adsorbed gas decreases with the increase of adsorption temperature and the isosteric heat increases with the increase of the volume of the adsorbed gas.

Thermal management has become a serious problem with development of miniaturized, high integration and high performance electronics devices, where the improvement of thermal conductivity on polymer composites is crucial for the internal heat transfer and dissipation. In this work, graphene aerogels (GA) with three-dimensional (3D) structure were prepared by a simple method and reduced by different ways. Then, GA were used as fillers to prepare high thermal conductivity polymer composites. A thermal conductivity of 3.36 W m −1 K −1 at room temperature was obtained when use polyurethane filling the hydroiodic acid reduced GA composite (HI-RGA/PU), and the graphene loading was as low as 2.5 wt.%. This result is better than most researches of polymer-based thermal conductive composites. Furthermore, the heat transfer test and thermal cycling test show that HI-RGA/PU has a good and stable performance in the practical application as thermal interface material (TIM), which proves that GA is a promising filler for thermal conductive material.

To fabricate ceramic components with a complex structure, the bottom-up mask-projection stereolithography (MP-SL) technique is currently employed. However, a fracture or a defect is normally found because of the large separation force formed between the newly cured layer and the bottom surface of the slurry tank. Hence, to overcome this issue, an oxygen-permeable layer is integrated into the conventional MP-SL system for printing a β-TCP ceramic slurry in this study. The system is based on the fact that oxygen inhibits the photopolymerization process by consuming free radicals. The effects of the light exposure time and oxygen concentration on the curing depth and thickness of the oxygen-inhibition layer were investigated. Moreover, the separation forces were indirectly determined using a weight sensor. The results show that the oxygen-inhibition layer helped in reducing the separation force by 60% compared to that wherein oxygen is not employed. The solid loading could be increased by up to 44 vol% and the printable cross-sectional area by 5 times. In summary, the proposed oxygen-controlled bottom-up MP-SL technique helped in improving the ceramic printing efficiency and product quality.

Nitrate treatment performance and denitrification activity were compared between denitrifying biological filters (DNBFs) based on dewatered alum sludge (DAS) and neutralized used acid (NUA). The spatiotemporal distribution of denitrifying genes and the genetic potential associated with denitrification activity and nitrate removal in both DNBFs were also evaluated. The removal efficiency of NUA–DNBF increased by 8% compared with that of DAS–DNBF, and the former NUA–DNBF emitted higher amount of N2O. Analysis of abundance and composition profiles showed that denitrifying gene patterns varied more or less in two matrices with different depths at three sampling times. Burkholderiales, Rhodocyclales, and Rhizobiales were the most commonly detected in both media during stable periods. Denitrification was determined by the abundance of specific genes or their ratios as revealed by controlling factors. The enhanced nitrate removal could be due to increasing qnosZ or decreasing ∑qnir/qnosZ. Furthermore, NUA–DNBF solely reduced nitrate by increasing the denitrification enzyme activity.

Aromatic amines in mainstream cigarette smoke have long been monitored due to their carcinogenic toxicity. In this work, a reliable and rapid method was developed for the simultaneous determination of 9 aromatic amines in mainstream cigarette smoke by modified dispersive liquid liquid microextraction (DLLME) and ultraperformance convergence chromatography tandem mass spectrometry (UPC2-MS/MS). Briefly, the particulate phase of the cigarette smoke was captured by a Cambridge filter pad, and diluted hydrogen chloride aqueous solution is employed to extract the aromatic amines under mechanical shaking. After alkalization with sodium hydroxide solution, small amount of toluene was introduced to further extract and enrich aromatic amines by modified DLLME under vortexing. After centrifugation, toluene phase was purified by a universal QuEChERS cleanup kit and was finally analyzed by UPC2-MS/MS. Attributing to the superior performance of UPC2-MS/MS, this novel approach allowed the separation and determination of 9 aromatic amines within 5.0min with satisfactory resolution and sensitivity. The proposed method was finally validated using Kentucky reference cigarette 3R4F, and emission levels of targeted aromatic amines determined were comparable to previously reported methods At three different spiked levels, the recoveries of most analytes were ranged from 74.01% to 120.50% with relative standard deviation (RSD) less than 12%, except that the recovery of p-toluidine at low spiked level and 3-aminobiphenyl at medium spiked level was 62.77% and 69.37% respectively. Thus, this work provides a novel alternative method for the simultaneous analysis of 9 aromatic amines in mainstream cigarette smoke.

Aluminum (Al) treatment significantly decreased the dry weight (DW) of stem, shoot and whole plant of both Citrus sinensis and C. grandis, but did not change that of root. Al significantly decreased leaf DW of C. grandis, increased the ratio of root to shoot and the lignin content in roots of both species. The higher content of Al in leaves and stems and lignin in roots of C. grandis than that of C. sinensis might be due to the over-expression of Al sensitive 3 (ALS3) and cinnamyl alcohol deaminase (CAD) in roots of C. grandis, respectively. By using yeast-two-hybridazation (Y2H) and bimolecular fluorescence complementation (BiFC) techniques, we obtained the results that glutathione S-transferase (GST), vacuolar-type proton ATPase (V-ATPase), aquaporin PIP2 (PIP2), ubiquitin carboxyl-terminal hydrolase 13 (UCT13), putative dicyanin blue copper protein (DCBC) and uncharacterized protein 2 (UP2) were interacted with ALS3 and GST, V-ATPase, Al sensitive 3 (ALS3), cytochrome P450 (CP450), PIP2, uncharacterized protein 1 (UP1) and UP2 were interacted with CAD. Annotation analysis revealed that these proteins were involved in detoxification, cellular transport, post-transcriptional modification and oxidation-reduction homeostasis or lignin biosynthesis in plants. Real-time quantitative PCR (RT-qPCR) analysis further revealed that the higher gene expression levels of most of these interacting proteins in C. grandis roots than that in C. sinensis ones were consistent with the higher contents of lignin in C. grandis roots and Al absorbed by C. grandis. In conclusion, our study identified some key interacting components of Al responsive proteins ALS3 and CAD, which could further help us to understand the molecular mechanism of Al tolerance in citrus plants and provide new information to the selection and breeding of tolerant cultivars, which are cultivated in acidic areas.

Magnesium (Mg) deficiency is one of the major constraining factors that limit the yield and quality of agricultural products. Uniform seedlings of the Citrus sinensis were irrigated with Mg deficient (0 mM MgSO4) and Mg sufficient (1 mM MgSO4) nutrient solutions for 16 weeks. CO2 assimilation, starch, soluble carbohydrates, TBARS content and H2O2 production were measured. Transcriptomic analysis of C. sinensis leaves was performed by Illumina sequencing. Our results showed that Mg deficiency decreased CO2 assimilation, but increased starch, sucrose, TBARS content and H2O2 production in C. sinensis leaves. A total of 4864 genes showed differential expression in response to Mg deficiency revealed by RNA-Seq and the transcriptomic data were further validated by real-time quantitative PCR (RT-qPCR). Gene ontology (GO) enrichment analysis indicated that the mechanisms underlying Mg deficiency tolerance in C. sinensis may be attributed to the following aspects: a) enhanced microtubule-based movement and cell cycle regulation, b) elevated signal transduction in response to biotic and abiotic stimuli, c) alteration of biological processes by tightly controlling phosphorylation especially protein phosphorylation, d) down-regulation of light harvesting and photosynthesis due to the accumulation of carbohydrates, e) up-regulation of cell wall remodeling and antioxidant system. Our results provide a comprehensive insight into the transcriptomic profile of key components involved in the Mg deficiency tolerance in C. sinensis and enrich our understanding of the molecular mechanisms by which plants adapted to a Mg deficient condition.

Approximately 4000 diseases are associated with malfunctioning genes in a particular cell type. Gene-based therapy provides a platform to modify the disease-causing genes expression at the cellular level to treat pathological conditions. However, gene delivery is challenging as these therapeutic genes need to overcome several physiological and intracellular barriers in order, to reach the target cells. Over the years, efforts have been dedicated to develop efficient gene delivery vectors to overcome these systemic barriers. Chitosan, a versatile polysaccharide, is an attractive non-viral vector material for gene delivery mainly due to its cationic nature, biodegradability and biocompatibility. The present review discusses the design factors that are critical for efficient gene delivery/transfection and highlights the recent progress of gene therapy using chitosan-based carriers. Published version

Alkali-leaching residual wire sludge (AWRS) is an abundant by-product in the harmless disposal process of wire rope sludge. In this study, we modified AWRS through thermal treatment to produce a low-cost and highly efficient adsorbent for the removal of Cu2+ and Ni2+ from wastewater. The results indicated that AWRS calcinated at 700 °C exhibited maximum Cu2+ and Ni2+ removal capacities (36.48 mg/g and 46.58 mg/g, respectively). The adsorption process was observed to follow the Elovich kinetic model and the Langmuir–Freundlich isotherm model. The sorption of Cu2+ and Ni2+ on AWRS700 was highly pH dependent and behaved optimally at the solution pH values of 6 and 5, respectively. Column studies and physicochemical analyses (XRD, SEM-EDS, and XPS) indicated that the sorption of Cu2+ and Ni2+ on AWRS700 was mainly governed by the chemisorption mechanism, and this was attributed to active metal oxides (Fe2O3, CaO, and Al2O3) in AWRS700. Specifically, Cu2+ is mainly adsorbed on AWRS700 in the form of Cu(OH)2, CuO2, and CuFeO2, and Ni2+ is mainly adsorbed in the form of NiAlO4, Ni2O3, and Ni(OH)2. Given the low-cost and high adsorption efficiency of AWRS700, the developed AWRS700 is a promising adsorbent for Cu2+ and Ni2+ removal from wastewater.

4-(methylintrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N’-nitrosonornicotine (NNN) are the most prevalent and toxic tobacco specific nitrosamines (TSNAs). Due to their carcinogenicity, knowledge of the composition of NNK and NNN in tobacco is necessary. Herein, a sensitive and rapid method, which employs autoclave extraction-supercritical fluid chromatography/tandem mass spectrometry (SFC-MS/MS), has been developed for the analysis of NNK and NNN in tobacco. Both water-soluble and matrix-bound NNK and NNN were extracted with 100 mM ammonium acetate in an autoclave (130 °C, 4 h), and the aqueous extract was subjected to solvent replacement prior to SFC-MS/MS analysis. NNK and NNN were effectively separated within 5 min by using supercritical CO2 as the main mobile phase coupled with a co-solvent of methanol. Excellent linearity was obtained with coefficients of determination (R2) greater than 0.9997 in the range of 1–160 ng/mL and 5–800 ng/mL for NNK and NNN, respectively. The recoveries were in the range of 92.5–110.0% at different spiked levels of real samples. 12 tobacco samples which include 3 typical tobacco varieties of burley, flue-cured, and oriental tobaccos had been analyzed, and the fraction of matrix-bound NNK was determined as well. In addition, a comparison between the proposed SFC-MS/MS method and a validated liquid chromatography tandem mass spectrometry (LC–MS/MS) internal standard method was conducted. Both techniques exhibit comparable analysis results, but peak splitting of NNN was observed by LC-MSMS due to the existence of E/Z isomers, while SFC-MS/MS offers great improvement through elution condition optimization, demonstrating the applicability of SFC-MS/MS as an alternative tool for NNK and NNN analysis.

Scouring and bleaching are essential steps in flax yarn production; however, in many cases, these treatments have relatively low selectivity on non-cellulosic polysaccharides (NCPs) and lignin. Herein, the specific chemical properties of flax fibers through a variety of scouring and/or bleaching procedures are reviewed to understand their correlations with the mechanical and morphological characteristics. The hydrolysis behaviors of hemicellulose and lignin are different from those of cellulose during chlorine-alkali-oxygen (Cl-AO), enzyme-alkali-oxygen (EAO), and alkali-oxygen (AO) treatments, while the structural hemicellulose polysaccharides fractions were not affected by acid pretreatment followed by alkali scouring (AA) treatment. It was found that the unbleached AA treatment improved scouring efficiency to the greatest extent by decreasing 73.3 % of hemicellulose content and 59.8 % of lignin content compared to the untreated flax fibers and obtained the highest tensile strength (6.58 cN/dtex) and elongation (3.73 %). Delignification was more crucial on fiber tenacity and fineness than hemicellulose removal (R2 = 0.71, 0.79 vs R2 = 0.46, 0.61). Within the hemicellulose fractions, a corresponding beneficial relationship between the xylan (XYL) composition and flax fiber properties is presented. The correlation of GM and GGM contents in hemicellulose with flax fiber length was significant with R2 value 0.97 and 0.99, respectively. This study provides insight into the hydrolysis behavior of hemicellulose and a basis for developing scouring and/or bleaching models that can predict fiber properties.

In this study, the effects of oxygen content on transformation temperatures, microstructures and mechanical properties of Ti-4Zr-xO (wt%) alloys (x = 0, 0.15, 0.20, 0.25 and 0.30) were revealed. It was found that the increase in oxygen content can obviously increase the β-transition temperatures of Ti-4Zr-xO alloys. The microstructure of α phase were transformed from typical basket weave structure into flaky and equiaxed structure. Also, the tensile strength and yield strength of alloys increased obviously by adding oxygen element. In contrast, the elongation presented a decline trend as a whole except Ti-4Zr-0.25O alloy. Among present Ti-4Zr-xO compositions, Ti-4Zr-0.25O exhibited the best comprehensive mechanical properties due to the occurrence of nano-twins.

The depth profiles of aluminum (Al) ion implantation on 4H-SiC epilayers with implantation energy range from 90 keV to above 1 MeV have been studied. The SIMS profiles show that the channeling effect is significantly reduced as the energy increases. This is attributed to the dechanneling effects due to the introduction of interstitial type defects created by preceding implanting ions under high-implantion energy and high-dose level conditions. We compare experimental data with simulation results based on SRIM™ program and Sentaurus™ Monte Carlo (MC) model. The SRIM simulation shows good agreement with the experimental profiles around the projected range, but could not reproduce the channeling tails of the profiles. The calibrated sentaurus MC model can show good agreement with the experimental profiles of projected range and channeling. The effect of tilt angle and implantation temperature on the channeling in the calibrated sentaurus MC model is also studied.

This study employed a newly developed treatment biofilter to remove high nitrogen (N) concentration from synthetic livestock wastewater combined with media containing neutralized used acid (NUA) and dewatered alum sludge (DAS). This biofilter was also utilized to investigate the spatial and temporal distributions of ammonia-oxidizing bacterial (AOB) and nitrite-oxidizing bacterial (NOB) communities and their active responses to effluent characteristics. Data were obtained from 210 days of operations. Results showed that N removal was robust, with ammonia N and total N removal efficiencies of 59.8–82.1% and 57.5–74.9%, respectively. Denaturing gradient gel electrophoresis and sequence analyses revealed that the shift of AOB and NOB community structures in DAS was time dependent. These structures did not exhibit distinct differences in both media as depth varied. The retrieved AOB and NOB sequences from both media primarily belonged to Nitrosomonas, Nitrosovibrio, and Nitrobacter. The nitrification rates indicated that the change in AOB activity corresponded to the AOB community structure variation in the system. The peak was observed in DAS at the final time. By contrast, the NOB activity was inconsistent with the trend of its community structure. The AOB rate was positively related to the NOB rate. This finding suggested that AOB and NOB mutually promoted each other. The AOB and NOB activities of DAS rather than those of NUA appeared dependent on available nitrate from the effluent. Overall, these findings on AOB and NOB helped enhance further understanding on the efficient N removal of the NUA–DAS system.

An LC-tandem MS (LC–MS/MS) method for the determination of 21 kinds of carcinogenic aromatic amines released from azo dyes in food wrappers was used in this research. Sodium dithionite was added to a citric acid buffer medium to reduce and decompose possible azo dyes. The extract was analyzed after liquid–liquid extraction (LLE) and dispersive SPE (d-SPE). The conditions for chromatographic separation, mass spectrum, LLE, and d-SPE were optimized. Under optimal conditions, the LOD was in the range of 0.13–0.35 mg/kg and LOQ in the range of 0.38–1.05 mg/kg, with the addition of standard recoveries of most aromatic amines being ≥80% and RSDs ≤10%. The recoveries for 2,4-diaminotoluene and 2,4-diaminoanisole were significantly lower, being ≤40%. The method was successfully used to analyze 30 practical samples, and the results showed that it is user-friendly, with high sensitivity, rapid control, and low matrix interference.

Air plasma has been widely applied in industrial manufacture. In this paper, both dry and humid air plasmas' thermodynamic and transport properties are calculated in temperature 300-100000 K and pressure 0.1-100 atm. To build a more precise model of real air plasma, over 70 species are considered for composition. Two different methods, the Gibbs free energy minimization method and the mass action law method, are used to determinate the composition of the air plasma in a different temperature range. For the transport coefficients, the simplified Chapman-Enskog method developed by Devoto has been applied using the most recent collision integrals. It is found that the presence of CO2 has almost no effect on the properties of air plasma. The influence of H2O can be ignored except in low pressure air plasma, in which the saturated vapor pressure is relatively high. The results will serve as credible inputs for computational simulation of air plasma.

In order to refine and homogenise microstructure and to improve mechanical properties of the magnesium alloys for biomedical application, the Mg–2.0Nd–0.1Zn–0.4Zr (wt-%, NZ20K) alloy with low amount of alloying elements was processed by double extrusion and aging processes (DEAP). Compared to the NZ20K alloy after once extrusion and aging processes (OEAP), the microstructure becomes finer and more homogeneous, and the elongation is raised up ∼121% by DEAP. Moreover, the yield strength and ultimate tensile strength are improved ∼27 and ∼16% respectively. Additionally, the corrosion rate of the NZ20K alloy by the DEAP is a little slower than that of the OEAP. It can be concluded that the mechanical properties, as well as the corrosion resistance of the NZ20K alloy, are able to be enhanced by the double extrusion and aging processes.

Recently, VS4 with advanced sodium storage performance has attracted researchers’ attention. Herein, VS4 with a 3D structure composed of uniform nanosheets is successfully prepared through a simple solvothermal method. SEM and TEM images exhibit that VS4 with a perfect 3D structure can be obtained at 180 °C after 20 h (VS4-20 h). Benefiting from the perfect 3D structure, VS4-20 h presents excellent sodium storage performance. It delivers a reversible capacity of 472 mA h g−1 after 100 cycles at 0.2 A g−1. Moreover even tested at a higher current density of 1A g−1, a stable reversible capacity of 410 mA h g−1 can be retained after 400 cycles. Additionally, the VS4-20 h electrode also shows a high initial coulombic efficiency (82.2%) and outstanding rate-performance (345 mA h g−1 at 5 A g−1 and 288 mA h g−1 at 10 A g−1). The simple preparation method in this work and excellent electrochemical performance endow the VS4 electrode as a promising anode material for sodium-ion batteries.

Fe3O4 shows great potential in the energy storage field; however, the low conductivity, particles aggregation and large volume change during the electrochemical process seriously limit its practical application. Here, spindle-shaped core-shell Fe3O4@N-doped carbon scattered in graphene (Fe3O4@NCm/rGO) has been successfully fabricated. SEM and TEM results indicate that the N-doped carbon shell with a thickness of 10 nm was homogenously coating on the spindle-shaped Fe3O4 surface, and at the same time the Fe3O4@NCm particles evenly dispersed on the graphene sheets. Profiting from the N-doped carbon shell and graphene, the Fe3O4@NCm/rGO electrode delivers excellent electrochemical performances both in Li and Na ion half-cells (720 mAh g−1 at 1000 mA g−1 after 500 cycles and 237 mAh g−1 at 1000 mA g−1 after 2500 cycles for Li and Na ion half-cells, respectively). And most importantly, the Fe3O4@NCm/rGO electrode also presents superior lithium and sodium storage performances in Li and Na ion full-cells with 526 mAh g−1 for Li-ion full cell and 192 mAh g−1 for Na-ion full cell. These results demonstrate that the Fe3O4@NCm/rGO composites have great promising applications as anodes in both commercial Li/Na-ion batteries.

A three-dimensional (3D) ultralight Co/C@CNF aerogel is fabricated by directional freeze-casting of cellulose nanofiber (CNF) anchored Zeolitic Imidazolate Framework-67 (ZIF-67) and subsequently annealing process of ZIF-67/CNF aerogel at different temperature from 700℃ to 900℃. The resultant Co/C@CNF aerogels are interconnected carbon sheet networks inlaid with Co/C nanoparticles, and the corresponding EMI shielding properties are proved to be dependent on the annealing temperature. Remarkably, the Co/C@CNF aerogel at 900℃ displays high EMI shielding effectiveness of 35.1 dB at a density of only 1.74 mg cm−3, corresponding to the highest specific SE reaching 20172.4 dB cm3 g−1, and an extremely high absorption characteristic. This good performance is benefiting from magnetic nanoparticles of Co embedded in carbon sheet and 3D interconnected networks, enhancing magnetic loss and dielectric loss ability. This study offers a facile approach to design novel aerogels with ultra-high absorption for highly efficient EMI shielding application in aerospace, portable electronics, and so on.

A newly combined dewatered alum sludge (DAS) and neutralized used acid (NUA) biofilter has been constructed and investigated recently, aiming for improving nitrate (NO3−–N) removal in simulated groundwater and exploring the spatiotemporal distribution of nirS and nosZ. The biofilter achieved 81.54% and 13.6 g N/ (m3 d) removal efficiency of NO3−–N during the stabilization period. Spatiotemporal distributions of diversity and composition of nirS and nosZ varied approximately in two media with depths and time. Both DAS and NUA played important roles in attenuating nitrate because of predominant denitrifying genera functions, and the core differences were Rhodanobacter and Rhodobacter in DAS while Halomonas, Pseudogulbenkiania, and Cupriavidus in NUA. Acting as the strongly correlated genera, Magnetospirillum and Halomonas had a significantly positive or negative correlation with other dominant genera. Positive correlations existed among COD, TN, NO3−−N, NO2−−N, and both nirS and nosZ in the DAS filter, whereas the correlations were negative in the NUA filter. Particularly, the effluent concentration of NO3−−N had a significantly negative correlation with the relative abundance of Rubrivivax and Pseudomonas. These results could be useful in adjusting the denitrification of nitrogen contaminants at the genetic level, especially in mitigating the influence of discharge of NO3−−N on the process of groundwater restoration.

Herein, we demonstrate an effective strategy to prepare N and P co-doped carbon nanotubes (NPC) using pyrrole monomer and phytic acid as precursors. Importantly, density functional theory (DFT) and pseudocapacitance contribution calculations certify that the electron mobility and electrochemical kinetics of the carbon nanotubes are enhanced by P-doping. Furthermore, the co-effect of the special hollow nanotubes structure and dual N, P doping endows the NPC with excellent rate performance and long-term cycling stability when it is used as an anode material for sodium ion batteries. Even tested at a high current density of 5000 mA g−1, a high reversible capacity of 180.3 mA h g−1 can be obtained after 3000 cycles for the NPC electrode.

(Burk.) F.H. Chen, a valuable Chinese medicine, is currently confronted with arsenic (As) contamination in China due to soil pollution. Our previous research demonstrated that Fe(0) and zeolite had a certain inhibitory effect on As accumulation in . In order to further reduce As accumulation in the plant, a synthetic iron material (Fe-Ce oxide [FC]) with high As adsorption capacity was tested for As remediation. In the study, after FC was applied to the As-contaminated soil, was planted in the soil. The As leaching behavior of the treated soil and As accumulation in were evaluated. The results showed that FC immobilized As more effectively than Fe(0) and zeolite in soils with high As concentrations. When the FC dosage was 0.5 % (w/w), As concentration of root (the main medicinal part) decreased by 56%, and root biomass increased by 55%. Results indicated FC could reduce the non-specifically adsorbed As fraction (F1) and specifically adsorbed As fraction (F2) by 22 to 31% and 5 to 17%, respectively, thus reducing the toxicity characteristic leaching procedure leachable As concentration by 41 to 67%. The finding of an iron plaque coating on the plant root and its function as a barrier to As uptake by is reported here for the first time. The occurrence of iron plaque led to a reduction in As concentration in the phellem and xylem-phloem by 66 to 80% and 43 to 70%, respectively. Our findings will help in developing As contamination control in areas where is planted and set a foundation for a FC-based As immobilization technology.

This is a review of nanotherapeutic systems, specifically those that exhibit controlled release of the encapsulated bioactive compound. The survey includes the delivery of a range of bioactive compounds, from lipophilic small molecules to hydrophilic proteins and siRNA molecules. The research into enabling sustained delivery of these compounds from nanocarriers has been prolific, but clinical success has been harder to achieve. This is partly because achieving true sustained duration of action over several days is difficult when the carrier dimensions become less than about 400 nm, due to the much shorter diffusion path length compared to micron-sized carrier systems. Other options must be sought to control the efflux of incorporated bioactives, particularly when these bioactives have moderate to high hydrophilicity. A few of these options are discussed critically in this review. We also answer the question: is controlled release needed for nanotherapies? We present the case for controlled release in specific conditions, with two examples from our own work: one for treatment of glaucoma, and the second for inhibition of fibrosis following surgery. The former is sustaining the release of a small-molecule lipophilic drug, while the latter focusses on sustained siRNA delivery.

Nornicotine, an alkaloid constituent of tobacco, is a precursor to the carcinogen N-nitrosonornicotine that is produced during the curing and processing of tobacco. Accumulating evidence reveals that nornicotine enantiomers have different neurochemical and behavioral effects. In the present study, an accurate and rapid method was developed for the enantioseparation of (R)-(+)-nornicotine and (S)-(-)-nornicotine enantiomers in tobacco by ultra-performance convergence chromatography with tandem mass spectrometry. Chromatographic conditions were investigated to achieve the optimal resolution of two enantiomers. Results indicated that (R)-(+)-nornicotine and (S)-(-)-nornicotine could be separated within 5 min when ammonium hydroxide was added into the cosolvent, and the best resolution (Rs = 4.76) was achieved on a immobilized cellulose tris-(3,5-dichlorophenylcarbamate) chiral stationary phase. The proposed method was validated and was finally applied to analyze the compositions of (R)-(+)-nornicotine and (S)-(-)-nornicotine in three typical types of tobaccos (flue-cured, burley, and oriental). It was found that, enantiomer fraction of nornicotine (the proportion of (S)-(-)-nornicotine in the nornicotine pool) in burley tobacco samples was relatively high and constant compared with flue-cured and oriental tobaccos. The effective and rapid enantioseparation of nornicotine may help the understanding of alkaloid metabolites in different tobacco varieties and may also benefit pharmacological studies of alkaloid enantiomers.

A series of graphene nanosheets-filled poly(methyl methacrylate) nanocomposites (GNS/PMMA) is successfully prepared by an in situ fast polymerization method with graphene weight fractions from 0.1 to 2.0 wt %. In situ polymerization is effective in well dispersing of GNS in matrixes and suitable for both low and high content of GNS. The synthesis processes of polymer composites could be simplified and fast by using industrial grade graphene. The GNS fillers are found to disperse homogeneously in the PMMA matrix. The maximum electrical conductivity of the composites achieves 0.57 S m−1, with an extremely low percolation threshold of 0.3 wt %. The electrical conductivities are further predicted by percolation theory and found to agree well with the experimental results. The results indicate that the microstructures, thermal, electrical, and mechanical properties of PMMA polymer are significantly improved by adding a low amount of graphene nanosheets. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43423.

In many unconventional reservoirs, gas wells do not perform to their potential when water-based fracturing fluids are used for treatments. The sub-optimal fracture productivity can be attributed to many factors such as effective fracture length loss, low load fluid recovery, flowback time, and water availability. The development of unconventional reservoirs has, therefore, prompted the industry to reconsider waterless fracturing treatments as viable alternatives to water-based fracturing fluids. In this paper, a simulation approach was used by coupling a fracture propagation model with a multiphase flow model. The Toolachee Formation is a tight sand in the Cooper Basin, around 7,200 ft in depth, and has been targeted for gas production. In this study, a 3D hydraulic fracture propagation model was first developed to provide fracture dimensions and conductivity. Then, from an offset well injection fall off test, the model was tuned by using different calibration parameters such as fracture gradient and closure pressure to validate the model. Finally, fracture propagation model outputs were used as the inputs for multiphase flow reservoir simulation. A large number of cases were simulated based on different fraccing fluids and the concept of permeability jail to represent several water-induced damage effects. It was found that LPG was a successful treatment, especially in a reservoir where the authors suspected the presence of permeability jails. The authors also observed that total flowback recovery approached 76% within 60 days in the case of using gelled LPG. Modelling predictions also support the need for high-quality foam, and LPG can be expected to bring long-term productivity gains in normal tight gas relative permeability behaviour.