Extraction and identification of steroidal saponins from Polygonatum cyrtonema Hua using natural deep eutectic solvent-synergistic quartz sand-assisted extraction method.

In this study, quartz sand with particularly sharp nanoscale edges acted like a nanoscale knife physically cut cells of Polygonatum cyrtonema Hua into nanosized particles and was synergized with natural deep eutectic solvent to extract steroidal saponins of Polygonatum cyrtonema Hua. The natural deep eutectic solvent (choline chloride-lactic acid)-synergistic quartz sand-assisted extraction was optimized using response surface methodology. The steroidal saponins purified with AB-8 macroporous resin were identified using ultra-high-performance liquid chromatography-triple time of flight mass spectrometry. The results showed that the experimental total saponins content value (36.97 ± 0.12 mg dioscin equivalent/g dry weight) at optimal extraction conditions with a temperature of 68°C, a rotational speed of 20 400 rpm, shear time of 4.3 min, the liquid-solid ratio of 38 ml/g, was close to the maximum possible theoretical value (36.64 mg dioscin equivalent/g dry weight). A total of 20 steroidal saponins were identified, among which the content of (25R)-Kingianoside E was the highest (102.66 ± 3.47 mg/g). Furthermore, a new steroid saponin (3ß,25S)-26-(ß-D-glucopyranosyloxy)-22-hydroxyfurost-5-en-3-yl 4-O-ß-D-glucopyranosyl-ß-D-galactopyranoside+Glc was found for the first time. These results revealed that natural deep eutectic solvent-synergistic quartz sand-assisted extraction was an efficient and green method to extract a variety of steroidal saponins.

All-Nanofiber-Based Janus Epidermal Electrode with Directional Sweat Permeability for Artifact-Free Biopotential Monitoring.

Epidermal electronics have been developed with gas/sweat permeability for long-term wearable electrophysiological monitoring. However, the state-of-the-art breathable epidermal electronics ignore the sweat accumulation and immersion at the skin/device interface, resulting in serious degradation of the interfacial conformality and adhesion, leading to signal artifacts with unstable and inaccurate biopotential measurements. Here, the authors present an all-nanofiber-based Janus epidermal electrode endowed with directional sweat transport properties for artifact-free biopotential monitoring. The designed Janus multilayered membrane (≈15 µm) of superhydrophilic-hydrolyzed-polyacrylonitrile (HPAN)/polyurethane (PU)/Ag nanowire (AgNW) can quickly (less than 5 s) drive sweat away from the skin/electrode interface while resisting its penetration in the reverse direction. Along with the medical adhesive (MA)-reinforced junction-nodes, the adhesion strength among the heterogeneous interfaces can be greatly enhanced for robust mechanical-electrical stability. Therefore, their measured on-body electromyography (EMG) and electrocardiography (ECG) signals are free of sweat artifacts with negligible degradation and baseline drift compared to commercial Ag/AgCl gel electrodes and hydrophilic textile electrodes. This work paves a way to design novel directional-sweat-permeable epidermal electronics that can be conformally attached under sweaty conditions for long-term biopotential monitoring and shows the potential to apply epidermal electronics to many challenging conditions.

Space-Confined One-Step Growth of 2D MoO2 /MoS2 Vertical Heterostructures for Superior Hydrogen Evolution in Alkaline Electrolytes.

2D material-based heterostructures are constructed by stacking or spicing individual 2D layers to create an interface between them, which have exotic properties. Here, a new strategy for the in situ growth of large numbers of 2D heterostructures on the centimeter-scale substrate is developed. In the method, large numbers of 2D MoS2 , MoO2 , or their heterostructures of MoO2 /MoS2 are controllably grown in the same setup by simply tuning the gap distance between metal precursor and growth substrate, which changes the concentration of metal precursors feed. A lateral force microscope is used first to identify the locations of each material in the heterostructures, which have MoO2 on the top of MoS2 . Noteworthy, the creation of a clean interface between atomic thin MoO2 (metallic) and MoS2 (semiconducting) results in a different electronic structure compared with pure MoO2 and MoS2 . Theoretical calculations show that the charge redistribution at such an interface results in an improved HER performance on the MoO2 /MoS2 heterostructures, showing an overpotential of 60 mV at 10 mA cm-2 and a Tafel slope of 47 mV dec-1 . This work reports a new strategy for the in situ growth of heterostructures on large-scale substrates and provides platforms to exploit their applications.

A review on chemical and physical modifications of phytosterols and their influence on bioavailability and safety.

Phytosterols have been shown to lower cholesterol levels and to have antioxidant, anti-inflammatory and other biological activities. However, the high melting point and poor solubility limit their bioavailability and practical application. It is advantageous to modify phytosterols chemically and physically. This article reviews and discusses the chemical and physical modifications of phytosterols, as well as their effects on the bioavailability and possible toxicity in vivo. The current research on chemical modifications is mainly focused on esterification to increase the oil solubility and water solubility. For physical modifications (mainly microencapsulation), there are biopolymer-based, surfactant-based and lipid-based nanocarriers. Both chemical and physical modifications of phytosterols can effectively increase the absorption and bioavailability. The safety of modified phytosterols is also an important issue. Phytosterol esters are generally considered to be safe. However, phytosterol oxides, which may be produced during the synthesis of phytosterol esters, have shown toxicity in animal models. The toxicity of nanocarriers also needs further studies.

Trait correlated expression combined with eQTL and ASE analyses identified novel candidate genes affecting intramuscular fat.

BACKGROUND: Intramuscular fat (IMF) content is a determining factor for meat taste. The Luchuan pig is a fat-type local breed in southern China that is famous for its desirable meat quality due to high IMF, however, the crossbred offspring of Luchuan sows and Duroc boars displayed within-population variation on meat quality, and the reason remains unknown. RESULTS: In the present study, we identified 212 IMF-correlated genes (FDR ≤ 0.01) using correlation analysis between gene expression level and the value of IMF content. The IMF-correlated genes were significantly enriched in the processes of lipid metabolism and mitochondrial energy metabolism, as well as the AMPK/PPAR signaling pathway. From the IMF-correlated genes, we identified 99 genes associated with expression quantitative trait locus (eQTL) or allele-specific expression (ASE) signals, including 21 genes identified by both cis-eQTL and ASE analyses and 12 genes identified by trans-eQTL analysis. Genome-wide association study (GWAS) of IMF identified a significant QTL on SSC14 (p-value = 2.51E-7), and the nearest IMF-correlated gene SFXN4 (r = 0.28, FDR = 4.00E-4) was proposed as the candidate gene. Furthermore, we highlighted another three novel IMF candidate genes, namely AGT, EMG1, and PCTP, by integrated analysis of GWAS, eQTL, and IMF-gene correlation analysis. CONCLUSIONS: The AMPK/PPAR signaling pathway together with the processes of lipid and mitochondrial energy metabolism plays a vital role in regulating porcine IMF content. Trait correlated expression combined with eQTL and ASE analysis highlighted a priority list of genes, which compensated for the shortcoming of GWAS, thereby accelerating the mining of causal genes of IMF.

Controlled Growth of Large-Sized and Phase-Selectivity 2D GaTe Crystals.

GaTe has recently attracted significant interest due to its direct bandgap and unique phase structure, which makes it a good candidate for optoelectronics. However, the controllable growth of large-sized monolayer and few-layer GaTe with tunable phase structures remains a great challenge. Here the controlled growth of large-sized GaTe with high quality, chemical uniformity, and good reproducibility is achieved through liquid-metal-assisted chemical vapor deposition method. By using liquid Ga, the rapid growth of 2D GaTe flakes with high phase-selectivity can be obtained due to its reduced reaction temperature. In addition, the method is used to synthesize many Ga-based 2D materials and their alloys, showing good universality. Raman spectra suggest that the as-grown GaTe own a relatively weak van der Waals interaction, where monoclinic GaTe displays highly-anisotropic optical properties. Furthermore, a p-n junction photodetector is fabricated using GaTe as a p-type semiconductor and 2D MoSe2 as a typical n-type semiconductor. The GaTe/MoSe2 heterostructure photodetector exhibits large photoresponsivity of 671.52 A W-1 and high photo-detectivity of 1.48 × 1010 Jones under illumination, owing to the enhanced light absorption and good quality of as-grown GaTe. These results indicate that 2D GaTe is a promising candidate for electronic and photoelectronic devices.

Stretchable multifunctional hydrogels for sensing electronics with effective EMI shielding properties.

Hydrogel-based soft and stretchable materials with skin/tissue-like mechanical properties provide new avenues for the design and fabrication of wearable sensors. However, synthesizing multifunctional hydrogels that simultaneously possess excellent mechanical, electrical and electromagnetic interference (EMI) shielding effectiveness is still a great challenge. In this work, the freeze-casting method is employed to fabricate a multifunctional hydrogel by filling Fe3O4 clusters into poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT:PSS) and polyvinyl alcohol (PVA) composite aqueous solution. The hydrogel possesses superior electrical and mechanical properties as well as great electromagnetic wave shielding properties. Benefiting from the high stretchability (∼904.5%) and fast sensing performance (response time ∼9 ms and self-recovery time ∼12 ms within the strain range ∼100%), the monitoring of human activities and manipulation of a remote-controlled toy car using the hydrogel-based stretchable strain sensors are successfully demonstrated. In addition, a great EMI shielding effectiveness with more than 46 dB in the frequencies of 8-12.5 GHz can be obtained, which provides an alternative strategy for designing next-generation EMI shielding materials. These results indicate that the multifunctional hydrogels can be used as flexible and stretchable sensing electronics requiring effective EMI shielding.

Genome-wide identification and expression analysis of detoxification efflux carriers (DTX) genes family under abiotic stresses in flax.

The detoxification efflux carriers (DTX)/multidrug and toxic compound extrusion (MATE) transporters encompass an ancient gene family of secondary transporters involved in the process of plant detoxification. A genome-wide analysis of these transporters was carried out in order to better understand the transport of secondary metabolites in flaxseed genome (Linum usitassimum). A total of 73 genes coding for DTX/MATE transporters were identified. Gene structure, protein domain and motif organization were found to be notably conserved over the distinct phylogenetic groups, showing the evolutionary significant role of each class. Gene ontology (GO) annotation revealed a link to transporter activities, response to stimulus and localizations. The presence of various hormone and stress-responsive cis-regulatory elements in promoter regions could be directly correlated with the alteration of their transcripts. Tertiary structure showed conservation for pore size and constrains in the pore, which indicate their involvement in the exclusion of toxic substances from the cell. MicroRNA target analysis revealed that LuDTXs genes were targeted by different classes of miRNA families. Twelve LuDTX genes were chosen for further quantitative real-time polymerase chain reaction analysis in response to cold, salinity and cadmium stress at 0, 6, 12 and 24 hours after treatment. Altogether, the identified members of the DTX gene family, their expression profile, phylogenetic and miRNAs analysis might provide opportunities for future functional validation of this important gene family in flax.

Synthesis of Ultrahigh-Quality Monolayer Molybdenum Disulfide through In Situ Defect Healing with Thiol Molecules.

Monolayer transition metal dichalcogenides are 2D materials with many potential applications. Chemical vapor deposition (CVD) is a promising method to synthesize these materials. However, CVD-grown materials generally have poorer quality than mechanically exfoliated ones and contain more defects due to the difficulties in controlling precursors' distribution and concentration during growth where solid precursors are used. Here, thiol is proposed to be used as a liquid precursor for CVD growth of high quality and uniform 2D MoS2 . Atomic-resolved structure characterizations indicate that the concentration of sulfur vacancies in the MoS2 grown from thiol is the lowest among all reported CVD samples. Low temperature spectroscopic characterization further reveals the ultrahigh optical quality of the grown MoS2 . Density functional theory simulations indicate that thiol molecules could interact with sulfur vacancies in MoS2 and repair these defects during the growth of MoS2 , resulting in high-quality MoS2 . This work provides a facile and controllable method for the growth of high-quality 2D materials with ultralow sulfur vacancies and high optical quality, which will benefit their optoelectronic applications.

Dual-Additive Assisted Chemical Vapor Deposition for the Growth of Mn-Doped 2D MoS2 with Tunable Electronic Properties.

Doping of bulk silicon and III-V materials has paved the foundation of the current semiconductor industry. Controlled doping of 2D semiconductors, which can also be used to tune their bandgap and type of carrier thus changing their electronic, optical, and catalytic properties, remains challenging. Here the substitutional doping of nonlike element dopant (Mn) at the Mo sites of 2D MoS2 is reported to tune its electronic and catalytic properties. The key for the successful incorporation of Mn into the MoS2 lattice stems from the development of a new growth technology called dual-additive chemical vapor deposition. First, the addition of a MnO2 additive to the MoS2 growth process reshapes the morphology and increases lateral size of Mn-doped MoS2 . Second, a NaCl additive helps in promoting the substitutional doping and increases the concentration of Mn dopant to 1.7 at%. Because Mn has more valance electrons than Mo, its doping into MoS2 shifts the Fermi level toward the conduction band, resulting in improved electrical contact in field effect transistors. Mn doping also increases the hydrogen evolution activity of MoS2 electrocatalysts. This work provides a growth method for doping nonlike elements into 2D MoS2 and potentially many other 2D materials to modify their properties.

Phytosterols and their derivatives: Potential health-promoting uses against lipid metabolism and associated diseases, mechanism, and safety issues.

Consumption of phytosterols (PSs), the plant-based analogs of cholesterol, can reduce serum cholesterol levels. This review discusses the current state of the art into the research of the structural features and dietary sources of PSs and their derivatives. The effect of PSs on individual lipid metabolites is summarized in the present review. PS-related nonalcoholic fatty liver disease (NAFLD), obesity, and the alleviation of inflammatory bowel diseases are discussed. PSs reduce the risk of having NAFLD by improving the blood biochemical parameters related to lipid transport and metabolism. However, current research on the circulating PSs indicates its safety concern regarding fatty liver disease induction. In addition, PS oxidation products exhibit pro-atherogenic properties, cytotoxicity oxidative stress, apoptosis, and pro-inflammatory properties. Further research is needed to investigate the bioavailability and safety issues of PSs and their derivatives in animal models and clinical trials.

Ultrasensitive gas detection of large-area boron-doped graphene.

Heteroatom doping is an efficient way to modify the chemical and electronic properties of graphene. In particular, boron doping is expected to induce a p-type (boron)-conducting behavior to pristine (nondoped) graphene, which could lead to diverse applications. However, the experimental progress on atomic scale visualization and sensing properties of large-area boron-doped graphene (BG) sheets is still very scarce. This work describes the controlled growth of centimeter size, high-crystallinity BG sheets. Scanning tunneling microscopy and spectroscopy are used to visualize the atomic structure and the local density of states around boron dopants. It is confirmed that BG behaves as a p-type conductor and a unique croissant-like feature is frequently observed within the BG lattice, which is caused by the presence of boron-carbon trimers embedded within the hexagonal lattice. More interestingly, it is demonstrated for the first time that BG exhibits unique sensing capabilities when detecting toxic gases, such as NO2 and NH3, being able to detect extremely low concentrations (e.g., parts per trillion, parts per billion). This work envisions that other attractive applications could now be explored based on as-synthesized BG.

Isolation and Purification of Two Isoflavones from Hericium erinaceum Mycelium by High-Speed Counter-Current Chromatography.

High-speed counter-current chromatography (HSCCC) was used to separate and purify two isoflavones for the first time from Hericium erinaceum (H. erinaceum) mycelium using a two-phase solvent system composed of chloroform-dichloromethane-methanol-water (4:2:3:2, v/v/v/v). These two isoflavones were identified as genistein (4',5,7-trihydroxyisoflavone, C15H10O5) and daidzein (4',7-dihydroxyisoflavone, C15H10O4), using infrared spectroscopy (IR), electro-spary ionisation mass (ESI-MS), ¹H-nuclear magnetic resonance (NMR) and 13C-NMR spectra. About 23 mg genistein with 95.7% purity and 18 mg daidzein with 97.3% purity were isolated from 150 mg ethanolic extract of H. erinaceum mycelium. The results demonstrated that HSCCC was a feasible method to separate and purify genistein and daidzein from H. erinaceum mycelium.

Imidazole-Bearing Polymeric Micelles for Enhanced Cellular Uptake, Rapid Endosomal Escape, and On-demand Cargo Release.

The complex design of multifunctional nanomedicine is beneficial to overcome the multiple biological barriers of drug delivery, but it also presents additional hurdles to clinical translation (e.g., scaling-up and quality control). To address this dilemma, we employed a simple imidazole-bearing polymer micelle for enhanced cellular uptake, facilitated endosomal escape, and on-demand release of a model drug, SN-38. The micelles were crosslinked by the reversible imidazole/Zn2+ coordination with a drug loading of ca. 4% (w/w) and a diameter less than 200 nm. Under mimicked tumor microenvironment (pH 6.8), the surface charge of micelles reversed from negative to positive, leading to enhanced micelles uptake by model 4T1 cells. Such effect was verified by fluorescent labelling of micelles. Compared to imidazole-free nanocarriers, the charge-reversal micelles delivered significantly more SN-38 to 4T1 cells. Due to the proton sponge effect, imidazole-bearing micelles could rapidly escape from endosomes compared to the control micelles, as evidenced by the kinetic analysis of micelle/endosome co-localization. The coordination crosslinking also enabled the acid-triggered drug release. This work provides a "three birds with one stone" approach to achieve the multifunctionality of nanocarriers without complicated particle design, and opens new avenues of advancing nanomedicine translation via simple tailored nanocarriers.

Suppression of Cell Wall Degrading Enzymes and their Encoding Genes in Button Mushrooms (Agaricus bisporus) by CaCl2 and Citric Acid.

Fresh button mushrooms (Agaricus bisporus) were harvested and treated with a solution of 1.5% CaCl2 + 0.5% citric acid and stored for 16 days at 12 °C. The effects of this treatment on firmness, weight, color, cell wall compositions (cellulose and chitin) and cell wall degrading enzymes (cel1ulase, beta-1, 3 glucanase, chitinase and phenylalanine ammonialyase) were investigated during post-harvest storage. The expressions of major genes (Cel1, Glu1, Chi1 and PAL1) involved in cell wall degradation during post-harvest storage were also monitored. The results revealed that the post-harvest chemical treatment maintained better firmness, weight, color and inhibited cellulase, beta-1, 3 glucanase, chitinase and phenylalanine ammonialyase activities. These findings showed that the down-regulation of cell wall degrading enzymes is a possible mechanism that delays the softening of button mushrooms by the application of combined chemical treatment.

Loss-induced super scattering and gain-induced absorption.

Giant transmission and reflection of a finite bandwidth are demonstrated at the same wavelength when the electromagnetic wave is incident on a subwavelength array of parity-time (PT) symmetric dimers embedded in a metallic film. Remarkably, this phenomenon vanishes if the metallic substrate is lossless while keeping other parameters unchanged. Moreover super scattering can also occur when increasing the loss of the dimers while keeping the gain unchanged. When the metafilm is adjusted to the vicinity of an exceptional point, tuning either the substrate dissipation or the loss of the dimers can lead to supper scattering in stark contrast to what would be expected in conventional systems. In addition, increasing the gain of the dimers can increase the absorption near the exceptional point. These phenomena indicate that the PT-synthetic plasmonic metafilm can function as a thinfilm PT-plasmonic laser or absorber depending on the tuning parameter. One implication is that super radiation is possible from a cavity by tuning cavity dissipation or lossy element inside the cavity.

Metal to Insulator Quantum-Phase Transition in Few-Layered ReS2.

In ReS2, a layer-independent direct band gap of 1.5 eV implies a potential for its use in optoelectronic applications. ReS2 crystallizes in the 1T'-structure, which leads to anisotropic physical properties and whose concomitant electronic structure might host a nontrivial topology. Here, we report an overall evaluation of the anisotropic Raman response and the transport properties of few-layered ReS2 field-effect transistors. We find that ReS2 exfoliated on SiO2 behaves as an n-type semiconductor with an intrinsic carrier mobility surpassing µ(i) ∼ 30 cm(2)/(V s) at T = 300 K, which increases up to ∼350 cm(2)/(V s) at 2 K. Semiconducting behavior is observed at low electron densities n, but at high values of n the resistivity decreases by a factor of >7 upon cooling to 2 K and displays a metallic T(2)-dependence. This suggests that the band structure of 1T'-ReS2 is quite susceptible to an electric field applied perpendicularly to the layers. The electric-field induced metallic state observed in transition metal dichalcogenides was recently claimed to result from a percolation type of transition. Instead, through a scaling analysis of the conductivity as a function of T and n, we find that the metallic state of ReS2 results from a second-order metal-to-insulator transition driven by electronic correlations. This gate-induced metallic state offers an alternative to phase engineering for producing ohmic contacts and metallic interconnects in devices based on transition metal dichalcogenides.

Manganese Doping of Monolayer MoS2: The Substrate Is Critical.

Substitutional doping of transition metal dichalcogenides (TMDs) may provide routes to achieving tunable p-n junctions, bandgaps, chemical sensitivity, and magnetism in these materials. In this study, we demonstrate in situ doping of monolayer molybdenum disulfide (MoS2) with manganese (Mn) via vapor phase deposition techniques. Successful incorporation of Mn in MoS2 leads to modifications of the band structure as evidenced by photoluminescence and X-ray photoelectron spectroscopy, but this is heavily dependent on the choice of substrate. We show that inert substrates (i.e., graphene) permit the incorporation of several percent Mn in MoS2, while substrates with reactive surface terminations (i.e., SiO2 and sapphire) preclude Mn incorporation and merely lead to defective MoS2. The results presented here demonstrate that tailoring the substrate surface could be the most significant factor in substitutional doping of TMDs with non-TMD elements.

Extraction optimization by response surface methodology: Purification and characterization of phytosterol from sugarcane (Saccharum officinarum L.) rind.

A green, simple, and effective method for the extraction of sugarcane lipids from sugarcane rind was investigated by response surface methodology. The optimum conditions of technological progress obtained through response surface methodology were as follows: liquid-to-solid ratio 7.94: 1 mL/g, extraction temperature 50°C and extraction time 5.98 h. The practical sugarcane lipids extraction yield was 6.55 ± 0.28%, which was in good consistence with the predicted extraction yield of 6.47%. The results showed that the sugarcane lipids extraction yield obtained in optimum conditions increased by 1.16∼7.28-fold compared to the yields obtained in single-factor experiments. After saponification and SPE steps, the nonsaponifiable fraction of sugarcane lipids was analyzed by gas chromatography with mass spectrometry and high-performance liquid chromatography. ß-Sitosterol, stigmasterol, and campesterol were the prevailing phytosterols in the sample, while fucosterol, gramisterol, stigmast-7-en-3-ol, (3ß,5α,24S)-, stigmasta-4,6,22-trien-3α-ol, and cholest-8(14)-en-3ß-ol acetate were also identified as minor steroids. Furthermore, the content of ß-sitosterol and a mixture of campesterol and stigmasterol (quantified by high-performance liquid chromatography) was 44.18 mg/100 g dry weight and 43.20 mg stigmasterol/100 g dry weight, respectively. Our results indicate that sugarcane rind is a good source of phytosterol.

Impact of nano-CaCO3 -LDPE packaging on quality of fresh-cut sugarcane.

BACKGROUND: In order to evaluate the effects of nano-CaCO3 -based low density polyethylene (nano-CaCO3 -LDPE) packaging on the quality of fresh-cut sugarcane, concentrations of O2 and CO2 within the packages, overall visual quality (OVQ), total bacterial count (TBC), yeast and mould count (YMC), reducing sugar content and total phenolic content, respiration, ethylene production, and the activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), acid invertase (AI) and neutral invertase (NI) were examined during storage at 10 °C for 5 days. RESULTS: The transmission rate of O2 and CO2 of the nano-CaCO3 -LDPE material was lower than that of LDPE, which lead to the more rapid formation of gas environment with low O2 and high CO2 concentration in the package. TBC and YMC counts of fresh-cut sugarcane were significantly retarded by nano-CaCO3 -LDPE packaging. Nano-CaCO3 -LDPE packaging fresh-cut sugarcane exhibited significantly lower activities of PAL, PPO, POD AI and NI than LDPE packaging fresh-cut sugarcanes during the storage. Meanwhile, nano-CaCO3 -LDPE packaging significantly inhibited the increase of browning index and total phenolic content, while improving OVQ. CONCLUSION: Our results indicated that nano-CaCO3 -LDPE packaging together with the cold storage is a promising approach in inhibiting browning and maintaining quality of fresh-cut sugarcane.