Numerical simulation of aerosol dynamics in an impinging jet with microdroplet coalescence^§

Droplet laden jet plays important roles in cutting-edge technologies including spray cooling, aerosol jet printing, pollution control, and cascade impactors. In this work, a numerical simulation scheme for jet flow is proposed. The turbulence is calculated based on the-f model and the droplets are described by the discrete phase model. The droplet-droplet collisions are calculated by a mesh-independent collision model. The results are compared with an experiment in which concentric dual-ring deposition patterns were observed on the impinging plate. The effects of the droplet volume fraction are investigated. Criteria for the necessity of two-way coupling as well as coalescence calculation are provided. This work provides a practical tool for aerosol impinging research and design.</p

Impact of process parameters and sludge properties on electro-dewatering performance

In this paper, the semi-theoretical kinetics equations were proposed and the electro-dewatering experiments of sludge were conducted to analyze the kinetics laws of electro-dewatering under constant voltage and constant current. The results showed that the decline rate of moisture content remained stable under constant current, while the decline rate of moisture content kept decaying in the operating mode of constant voltage. No matter in what kind of operating mode, the change in decline rate of moisture content was consistent with that of filtrate flow rate, both of which were essentially dependent on the current. The follow-up electro-dewatering tests under constant voltage were carried out by using three different kinds of sludge to understand the mechanism of electro-dewatering. The results showed that the main parameters that controlled the electro-dewatering behavior were measured current, conductivity and zeta potential of sludge. When treated at 30 V, sludge C reached the lowest moisture content, owing to its higher conductivity and zeta potential. However, the poorer electro-osmotic effect of sludge C led to its higher average unit energy consumption. By comparison, an increase of applied voltage was more effective for electro-dewatering process of sludge C but at the expense of higher energy consumption, while sludge A and B were more inclined to improve the electro-dewatering effect by extending the dewatering time. Finally, the derived equations were demonstrated by the experiments, which could provide guidance for the practical applications.</p

Highly Efficient Dopamine Sensing with a Carbon Nanotube-Encapsulated Metal Chalcogenide Nanostructure

Carbon nanotube-encapsulated nickel selenide composite nanostructures were used as nonenzymatic electrochemical sensors for dopamine detection. These composite nanostructures were synthesized through a simple, one-step, and environmentally friendly chemical vapor deposition method, wherein the CNTs were formed in situ from pyrolysis of a carbon-rich metallo-organic precursor. The composition and morphology of these hybrid NiSe2-filled carbon nanostructures were confirmed by powder X-ray diffraction, Raman, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy images. Electrochemical tests demonstrated that the as-synthesized hybrid nanostructures exhibited outstanding electrocatalytic performance toward dopamine oxidation, with a high sensitivity of 19.62 μA μM–1 cm–2, low detection limit, broad linear range of 5 nM–640 μM, and high selectivity. The synergistic effects of enhanced electrochemical activity of nickel selenide along with the enhanced conductivity of carbon nanotubes led to the high electrocatalytic efficiency for these nanostructured composites. The high sensitivity and selectivity of this nanostructured composite could be exploited to develop simple, selective, and sensitive electrochemical sensors to detect and quantify dopamine in human tear samples with high reliability. This nanotube-encapsulated sensor, hence, paves the way for discoveries in the development of dopamine sensors with low cost and high stability, which can be used for noninvasive dopamine detection in peripheral bodily fluids

Two-Dimensional High‑k Nanosheets for Dielectric Polymer Nanocomposites with Ultrahigh Discharged Energy Density

Flexible dielectric materials with high electrical energy densities are of crucial importance in advanced electronics and electric power systems. The conventional methods for fabricating flexible dielectric materials with high electrical energy densities are introducing zero-, one-, and three-dimensional high-k inorganic nanofiller into a dielectric polymer matrix while less two-dimensional high-k nanofillers were included. Herein, two-dimensional (2D) high-k titanium dioxide nanosheets prepared by a one-step hydrothermal reaction were utilized to boost the energy storage performance of dielectric polymer nanocomposites. It was found that compared with the polymer matrix the nanocomposites not only exhibit an enhanced dielectric constant but also show suppressed dielectric loss, which is desirable for energy storage applications. The nanocomposite with 5 wt % 2D nanosheets exhibits a superhigh discharged energy density of 13.0 J/cm3 at 570 MV/m, which is nearly four times greater than that of commercialized biaxially oriented polypropylene (BOPP) (3.6 J/cm3 at 600 MV/m). In addition, nanocomposites with 5 wt % zero- and one-dimensional (0D and 1D) nanofiller are also fabricated for comparison. Results reveal that discharged energy densities of nanocomposites with 5 wt % 2D nanosheets are 236% and 382% higher than those of nanocomposites with 5 wt % 1D (5.5 J/cm3 at 400 MV/m) and 0D (3.4 J/cm3 at 300 MV/m) nanofiller, respectively. Finite element simulation was conducted to study the electric field distribution in nanocomposites with different shapes of nanofillers. Furthermore, the comparison of the current nanocomposites and previous reported nanocomposites with 0D, 1D, and 3D nanofillers shows that the 2D high-k nanofiller exhibited superior potential in advancing the energy storage nature of polymer nanocomposites. This remarkable exhibition of energy storage capability provides new insights into the development of high performance dielectric materials

Image_2_The DOF-Domain Transcription Factor ZmDOF36 Positively Regulates Starch Synthesis in Transgenic Maize.JPEG

Starch synthesis is a complex process that influences crop yield and grain quality in maize. Many key enzymes have been identified in starch biosynthesis; however, the regulatory mechanisms have not been fully elucidated. In this study, we identified a DOF family gene, ZmDOF36, through transcriptome sequencing analysis. Real-time PCR indicated that ZmDOF36 was highly expressed in maize endosperm, with lower expression in leaves and tassels. ZmDOF36 is a typical DOF transcription factor (TF) that is localized to the nucleus and possesses transcriptional activation activity, and its transactivation domain is located in the C-terminus (amino acids 227–351). Overexpression of ZmDOF36 can increase starch content and decrease the contents of soluble sugars and reducing sugars. In addition, abnormal starch structure in transgenic maize was also observed by scanning electron microscopy (SEM). Furthermore, the expression levels of starch synthesis-related genes were up-regulated in ZmDOF36-expressing transgenic maize. ZmDOF36 was also shown to bind directly to the promoters of six starch biosynthesis genes, ZmAGPS1a, ZmAGPL1, ZmGBSSI, ZmSSIIa, ZmISA1, and ZmISA3 in yeast one-hybrid assays. Transient expression assays showed that ZmDOF36 can activate the expression of ZmGBSSI and ZmISA1 in tobacco leaves. Collectively, the results presented here suggest that ZmDOF36 acts as an important regulatory factor in starch synthesis, and could be helpful in devising strategies for modulating starch production in maize endosperm.</p

Additional file 1 of Regulation of Drought and Salt Tolerance by OsSKL2 and OsASR1 in Rice

Additional file 1: Fig. S1. Phylogenetic relationships and sequence analysis of SK genes. A Phylogenetic tree constructed using MEGA7.0 based on the N-J method. Bootstrap values (above 50%) from 1000 replicates are indicated at each node. B Sequence alignment of conserved motifs of SK and SK-like homologs. C CS domain analysis in the AtSKL2 and OsSKL2 proteins. Fig. S2. Tissue expression profiles of OsSKL2 in rice root, stem and leaf. Fig. S3. Plasmid construction and expression of OsSKL2 in the transgenic rice lines. A Schematic diagram of the RNAi construct used for the development of OsSKL2 transgenic rice. B Expression levels of OsSKL2 in the wild-type (WT), OsSKL2 overexpressing (OE3 and OE6), and OsSKL2 RNAi (RI6 and RI9) transgenic lines as determined by qRT-PCR. OsActin1 was used as an RNA loading standard for comparison of OsSKL2 expression levels. C Expression levels of OsSKL1 and OsSKL2 in the OsSKL2-RNAi lines. Fig. S4. Analysis of the shikimic acid contents of wild-type (WT) and OsSKL2 transgenic plants. Fig. S5. OsSKL2 enhanced tolerance to osmotic stress at the germination stage. A Phenotypes of wild-type (WT) and OsSKL2 transgenic seeds germinated on 1/2 MS medium with or without 120/150 mM NaCl or 200/250 mM mannitol for 12 d, respectively (bar = 5 cm). B Seedling height and C the Seminal root number of WT and OsSKL2 transgenic plants before and after osmotic treatment. Data represent means ± SD (n = 36). Three independent experiments were carried out with similar results. All data were analyzed using one-way analysis of variance (ANOVA) based on the Student’s t-test. *P < 0.05, **P < 0.01. Fig. S6. OsSKL2 enhanced salt tolerance in rice grown in soil. A Phenotypes of wild-type (WT) and OsSKL2 transgenic seedlings before and after treatment with 1.5% NaCl. Four-week-old seedlings were used for NaCl treatment (bar = 10 cm). B Survival rates and C relative water contents of WT and OsSKL2 transgenic plants before and after treatment with 1.5% NaCl (n = 30). Fig. S7. OsSKL2 enhanced drought tolerance in rice grown in soil. A Phenotypes of wild-type (WT) and OsSKL2 transgenic seedlings before and after drought treatment, and after re-watering Four-week-old seedlings were used for drought treatment. (bar = 10 cm). B Survival rates and C relative water contents of WT and OsSKL2 transgenic plants before and after drought treatment (n = 30). Fig. S8. Comparison of ROS accumulation following treatment with ABA. Leaves of wild-type (WT) and OsSKL2 transgenic lines stained with DAB to show ROS accumulation following exposure to 5 μM ABA for 10 d (bar = 1 cm). Fig. S9. Interactions between OsSKL2, other SK homologs and OsASR1 based on a yeast two-hybrid assay. A Interactions between various fragments of OsSKL2 and OsASR1. B Interactions between OsASR1 and other rice SK homologs. Fig. S10. Subcellular localization and transcription activation assay of OsASR1. A Analysis of the subcellular localization of OsASR1 using a rice protoplast transient transformation system (bar = 10 μm). B Transactivation activity analysis of full-length OsASR1 in yeast. Fig. S11. Plasmid construction and expression levels of OsASR1 in the transgenic rice lines. A Schematic diagram of the RNAi construct used for OsASR1 transgenic rice. B–D Expression levels of OsASR1 in the wild-type (WT) and OsASR1 transgenic lines as determined by RT-PCR and qRT-PCR. E Expression levels of other rice ASR members in the OsASR1-RNAi lines. OsActin1 was used as an RNA loading standard for comparison of OsASR1 expression levels

Sequencing Heparan Sulfate Using HILIC LC-NETD-MS/MS

Heparan sulfate (HS) mediates a wide range of protein binding interactions key to normal and pathological physiology. Though liquid chromatography coupled with mass spectrometry (LC-MS) based disaccharide composition analysis is able to profile changes in HS composition, the heterogeneity of modifications and the labile sulfate group present major challenges for liquid chromatography tandem mass spectrometry (LC-MS/MS) sequencing of the HS oligosaccharides that represent protein binding determinants. Here, we report online LC-MS/MS sequencing of HS oligosaccharides using hydrophilic interaction liquid chromatography (HILIC) and negative electron transfer dissociation (NETD). A series of synthetic HS oligosaccharides varying in chain length (tetramers and hexamers), number of sulfate groups (3–7), sulfate patterns (sulfate positional isomers), and uronic acid epimerization (epimers) were separated and sequenced. The LC elution order of isomeric compounds was associated with their fine structure. The application of an online cation exchange device (ion suppressor) enhanced the precursor charge states, and the subsequent NETD produced abundant glycosidic fragments, allowing the characterization of both lowly sulfated and highly sulfated HS oligosaccharides. Furthermore, the diagnostic cross-ring ions differentiated the 6-O sulfation and 3-O sulfation, allowing unambiguous structural assignment. Collectively, this LC-NETD-MS/MS method is a powerful tool for sequencing of heterogeneous HS mixtures and is applicable for the differentiation of both isomers and epimers, for the characterization of saccharide mixtures with a varying extent of sulfation and even for the determination of both predominant and rare modification motifs. Thus, LC-NETD-MS/MS has great potential for further application to biological studies

Image_4_The DOF-Domain Transcription Factor ZmDOF36 Positively Regulates Starch Synthesis in Transgenic Maize.JPEG

Starch synthesis is a complex process that influences crop yield and grain quality in maize. Many key enzymes have been identified in starch biosynthesis; however, the regulatory mechanisms have not been fully elucidated. In this study, we identified a DOF family gene, ZmDOF36, through transcriptome sequencing analysis. Real-time PCR indicated that ZmDOF36 was highly expressed in maize endosperm, with lower expression in leaves and tassels. ZmDOF36 is a typical DOF transcription factor (TF) that is localized to the nucleus and possesses transcriptional activation activity, and its transactivation domain is located in the C-terminus (amino acids 227–351). Overexpression of ZmDOF36 can increase starch content and decrease the contents of soluble sugars and reducing sugars. In addition, abnormal starch structure in transgenic maize was also observed by scanning electron microscopy (SEM). Furthermore, the expression levels of starch synthesis-related genes were up-regulated in ZmDOF36-expressing transgenic maize. ZmDOF36 was also shown to bind directly to the promoters of six starch biosynthesis genes, ZmAGPS1a, ZmAGPL1, ZmGBSSI, ZmSSIIa, ZmISA1, and ZmISA3 in yeast one-hybrid assays. Transient expression assays showed that ZmDOF36 can activate the expression of ZmGBSSI and ZmISA1 in tobacco leaves. Collectively, the results presented here suggest that ZmDOF36 acts as an important regulatory factor in starch synthesis, and could be helpful in devising strategies for modulating starch production in maize endosperm.</p

Image_1_The DOF-Domain Transcription Factor ZmDOF36 Positively Regulates Starch Synthesis in Transgenic Maize.JPEG

Starch synthesis is a complex process that influences crop yield and grain quality in maize. Many key enzymes have been identified in starch biosynthesis; however, the regulatory mechanisms have not been fully elucidated. In this study, we identified a DOF family gene, ZmDOF36, through transcriptome sequencing analysis. Real-time PCR indicated that ZmDOF36 was highly expressed in maize endosperm, with lower expression in leaves and tassels. ZmDOF36 is a typical DOF transcription factor (TF) that is localized to the nucleus and possesses transcriptional activation activity, and its transactivation domain is located in the C-terminus (amino acids 227–351). Overexpression of ZmDOF36 can increase starch content and decrease the contents of soluble sugars and reducing sugars. In addition, abnormal starch structure in transgenic maize was also observed by scanning electron microscopy (SEM). Furthermore, the expression levels of starch synthesis-related genes were up-regulated in ZmDOF36-expressing transgenic maize. ZmDOF36 was also shown to bind directly to the promoters of six starch biosynthesis genes, ZmAGPS1a, ZmAGPL1, ZmGBSSI, ZmSSIIa, ZmISA1, and ZmISA3 in yeast one-hybrid assays. Transient expression assays showed that ZmDOF36 can activate the expression of ZmGBSSI and ZmISA1 in tobacco leaves. Collectively, the results presented here suggest that ZmDOF36 acts as an important regulatory factor in starch synthesis, and could be helpful in devising strategies for modulating starch production in maize endosperm.</p

Paper-Based Microfluidic Device (DON-Chip) for Rapid and Low-Cost Deoxynivalenol Quantification in Food, Feed, and Feed Ingredients

Mycotoxin contamination causes over $5 billion of economic loss per year in the North American food and feed industry. A rapid, low-cost, portable, and reliable method for on-site detection of deoxynivalenol (DON), a representative mycotoxin predominantly occurring in grains, would be helpful to control mycotoxin contamination. In this study, a paper-based microfluidic chip capable of measuring DON (DON-Chip) in food, feed, and feed ingredients was developed. The DON-Chip incorporated a colorimetric competitive immunoassay into a paper microfluidic device and used gold nanoparticles as a signal indicator. Furthermore, a novel ratiometric analysis method was proposed to improve detection resolvability. Detection of DON in the aqueous extracts from solid food, feed, or feed ingredients was successfully validated with a detection range of 0.01–20 ppm (using dilution factors from 10 to 104). Compared with conventional methods, the DON-Chip method could greatly reduce the cost and time of mycotoxin detection in the food and feed industry