Chemical profiling and multicomponents quantitative analysis of Panzerina lanata by ultra-fast liquid chromatography with tandem mass spectrometry.

Panzerina lanata is a Chinese medicine with the bioactivity of detumescence and detoxification. In this study, novel qualitative and quantitative methods were established by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry and ultra-high-performance liquid chromatography-triple quadrupole linear ion trap mass spectrometry, respectively. As a result, 20 compounds were identified or tentatively characterized including flavonoids, organic acids, alkaloids, and lignans, five of which were identified for the first time based on the reference standards. The quantitative approach exhibited good linearity (R2  > 0.995), precision (RSDs < 4.97%), stability (RSDs < 4.77%), and recovery (96.04-104.14%). Afterward, this method was implemented to determine 11 flavonoids in four batches of P. lanata. Among them, seven compounds were quantified for the first time. Narcissin was abundant in each batch of P. lanata (average of 10.890-14.230 mg/g) with the highest quantities. The results provide valuable information for quality evaluation.

Ultrathin dendrimer-graphene oxide composite film for stable cycling lithium-sulfur batteries.

Lithium-sulfur batteries (Li-S batteries) have attracted intense interest because of their high specific capacity and low cost, although they are still hindered by severe capacity loss upon cycling caused by the soluble lithium polysulfide intermediates. Although many structure innovations at the material and device levels have been explored for the ultimate goal of realizing long cycle life of Li-S batteries, it remains a major challenge to achieve stable cycling while avoiding energy and power density compromises caused by the introduction of significant dead weight/volume and increased electrochemical resistance. Here we introduce an ultrathin composite film consisting of naphthalimide-functionalized poly(amidoamine) dendrimers and graphene oxide nanosheets as a cycling stabilizer. Combining the dendrimer structure that can confine polysulfide intermediates chemically and physically together with the graphene oxide that renders the film robust and thin (<1% of the thickness of the active sulfur layer), the composite film is designed to enable stable cycling of sulfur cathodes without compromising the energy and power densities. Our sulfur electrodes coated with the composite film exhibit very good cycling stability, together with high sulfur content, large areal capacity, and improved power rate.

Strong Metal-Phosphide Interactions in Core-Shell Geometry for Enhanced Electrocatalysis.

Rational design of multicomponent material structures with strong interfacial interactions enabling enhanced electrocatalysis represents an attractive but underdeveloped paradigm for creating better catalysts for important electrochemical energy conversion reactions. In this work, we report metal-phosphide core-shell nanostructures as a new model electrocatalyst material system where the surface electronic states of the shell phosphide and its interactions with reaction intermediates can be effectively influenced by the core metal to achieve higher catalytic activity. The strategy is demonstrated by the design and synthesis of iron-iron phosphide (Fe@FeP) core-shell nanoparticles on carbon nanotubes (CNTs) where we find that the electronic interactions between the metal and the phosphide components increase the binding strength of hydrogen adatoms toward the optimum. As a consequence, the Fe@FeP/CNT material exhibits exceptional catalytic activity for the hydrogen evolution reaction, only requiring overpotentials of 53-110 mV to reach catalytic current densities of 10-100 mA cm-2.

Determination and pharmacokinetic study of four lignans in rat plasma after oral administration of an extract of Valeriana amurensis by ultra-high performance liquid chromatography with tandem mass spectrometry.

A selective and sensitive ultra-high performance liquid chromatography with tandem mass spectrometry method was developed and validated for the determination and pharmacokinetic study of (+)-8-hydroxypinoresinol-4'-O-ß -D-glucopyranoside, prinsepiol-4-O-ß-D-glucopyranoside, (+)-pinoresinol-4,4'-di-O-ß-D-glucopyranoside, and (-)-massoniresinol 3α-O-ß-D-glucopyranoside in rat plasma after the oral administration of a Valeriana amurensis extract. The analytes and ethyl 4-hydroxybenzoate (internal standard) were separated on a Waters ACQUITY UPLC HSS T3 chromatographic column. The detection was performed on a triple quadrupole tandem mass spectrometer in multiple reaction monitoring mode using an electrospray ionization source operating in negative ionization mode. The linear ranges (ng/mL) of the standard curves were 0.39-154.00, 0.62-244.70, 0.50-198.60, and 0.34-134.50 for (+)-8-hydroxypinoresinol-4'-O-ß-D-glucopyranoside, prinsepiol-4-O-ß-D-glucopyranoside, (+)-pinoresinol-4,4'-di-O-ß-D-glucopyranoside, and (-)-massoniresinol 3α-O-ß-D-glucopyranoside, respectively. The inter- and intra-day precisions were less than 11.0%, the accuracies were between -5.9 and 7.7%, and the extraction recoveries of the four analytes were > 81.2% from rat plasma. The method was successfully applied to a pharmacokinetic study of the four analytes after oral administration of a Valeriana amurensis extract to rats. The developed method has the potential for pharmacokinetic analysis and to provide additional information in the clinical application of Valeriana amurensis.

UHPLC-MS/MS Determination, Pharmacokinetic, and Bioavailability Study of Taxifolin in Rat Plasma after Oral Administration of its Nanodispersion.

A rapid and sensitive LC-MS/MS method based on the Triple Quad system has been developed and validated for the determination and pharmacokinetics of taxifolin and its nanodispersion in rat plasma. Taxifolin plasma samples along with butylparaben (internal standard) were pre-treated by liquid-liquid extraction with ethyl acetate, and then separated on a SB-C18 RRHD column (150 mm × 2.1 mm × 1.8 µm) using isocratic elution with a run time of 3.0 min. The mobile phase was acetonitrile-water (90:10, v/v) containing 5 mM ammonium acetate at a flow rate of 0.4 mL/min. Quantification of taxifolin was performed by the electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (MRM) mode with negative atmospheric ionization at m/z 303.0→285.0 for taxifolin and 193.1→92.0 for I.S., respectively. The calibration curve of taxifolin showed good linearity over a concentration range of 5.0-4280 ng/mL with a correlation coefficient of 0.9995. The limit of quantification (LLOQ) was 5.0 ng/mL. Intra-day, inter-day precision and accuracy (percent relative to standard deviation) were all within 8% at three concentration levels. A total recovery of taxifolin and I.S. was beyond 75%. The present LC-MS/MS method was successfully applied to pharmacokinetic studies of taxifolin after intravenous administration of taxifolin, oral administration of its physical mixture and nanodispersion. The absolute bioavailability of taxifolin was calculated as 0.75% for taxifolin nanodispersion and 0.49% for taxifolin, respectively.

Ferrocene-Promoted Long-Cycle Lithium-Sulfur Batteries.

Confining lithium polysulfide intermediates is one of the most effective ways to alleviate the capacity fade of sulfur-cathode materials in lithium-sulfur (Li-S) batteries. To develop long-cycle Li-S batteries, there is an urgent need for material structures with effective polysulfide binding capability and well-defined surface sites; thereby improving cycling stability and allowing study of molecular-level interactions. This challenge was addressed by introducing an organometallic molecular compound, ferrocene, as a new polysulfide-confining agent. With ferrocene molecules covalently anchored on graphene oxide, sulfur electrode materials with capacity decay as low as 0.014 % per cycle were realized, among the best of cycling stabilities reported to date. With combined spectroscopic studies and theoretical calculations, it was determined that effective polysulfide binding originates from favorable cation-π interactions between Li+ of lithium polysulfides and the negatively charged cyclopentadienyl ligands of ferrocene.

Notch1 signaling pathway promotes growth and metastasis of gastric cancer via modulating CDH5.

OBJECTIVE: To explore the underlying molecular mechanism of Notch1/cadherin 5 (CDH5) pathway in modulating in cell malignant behaviors of gastric cancer (GC). METHODS: We performed bioinformatic analyses to screen the potential target genes of Notch1 from cadherins in GC. Western blot and RT-PCR were conducted to detect CDH5 expression in GC tissues and cells. We utilized chromatin immunoprecipitation (CHIP) assays to assess the interaction of Notch1 with CDH5 gene. The effects of Notch1/CDH5 axis on the proliferation, invasion, migration and vasculogenic mimicry in GC cells were evaluated by EdU, wound healing, transwell, and tubule formation assays. RESULTS: Significantly increased CDH5 expression was found in GC tissues compared with paracancerous tissues and associated to clinical stage and poor overall survival (OS) in patients with GC. Notch1 positively regulate the expression of CDH5 in GC cells. CHIP assays validated that CDH5 was a direct target of Notch1. In addition, Notch1 upregulation enhanced the proliferation, migration, invasion and vasculogenic mimicry capacity of GC cells, which could be attenuated by CDH5 silencing. CONCLUSIONS: These results indicated Notch1 upregulation enhanced GC malignant behaviors by triggering CDH5, suggesting that targeting Notch1/CDH5 axis could be a potential therapeutic strategy for GC progression.

Optimizing the Use of Basil as a Functional Plant for the Biological Control of Aphids by Chrysopa pallens (Neuroptera: Chrysopidae) in Greenhouses.

Effective biological control agents that can provide sustainable pest control need to be researched in further detail; functional plants (or non-crop insectary plants), in particular, are garnering increased research interest. Much remains to be learned as to how non-crop plants can augment biological control in greenhouse systems. In this study, we combined laboratory and greenhouse assays to assess the extent to which basil (Ocimum basilicum L.) (Lamiales: Lamiaceae) affected the biological control of aphids by the predatory lacewing Chrysopa pallens (Rambur) (Neuroptera: Chrysopidae). In the presence of the target prey (peach aphid; Myzus persicae (Sulzer)), both the vegetative and flowering stages of basil enhanced C. pallens longevity and (early-age) fecundity as compared to a control treatment. When basil plants were established near aphid infested eggplants (Solanum melongena L.), the C. pallens colonization rate improved by 72-92% in the short-term. Lacewing colonization patterns were modulated by the basil planting density and spatial arrangement (i.e., perimeter planting vs. intercropping). Under high density intercrop arrangements, C. pallens colonization rates were highest, its populations persisted longer in the crop, and the aphid numbers declined more rapidly. Our work shows how basil enhanced the key fitness attributes of a generalist predatory lacewing and benefitted aphid biological control in a greenhouse setting.

Functional metal-organic framework boosting lithium metal anode performance via chemical interactions.

Dendrite growth and low coulombic efficiency are two major factors that limit the utilization of Li metal electrodes in future generations of high-energy-density rechargeable batteries. This article reports the first study on metal-organic framework (MOF) materials for boosting the electrochemical performance of Li metal electrodes and demonstrates the power of molecular-structure functionalization for realizing desirable ion transport and Li metal nucleation and growth. We show that dendrite-free dense Li deposition and stable Li plating/stripping cycling with high coulombic efficiency are enabled by modifying a commercial polypropylene separator with a titanium-based MOF (NH2-MIL-125(Ti)) material. The NH2-MIL-125(Ti)-coated-separator renders Li|Cu cells that can run for over 200 cycles at 1 mA cm-2-1 mA h cm-2 with average coulombic efficiency of 98.5% and Li|Li symmetric cells that can be cycled at 1 mA cm-2-1 mA h cm-2 for more than 1200 h without short circuiting. The superior cycling stability is attributed to the amine substituents in the NH2-MIL-125(Ti) structure which induce increased Li+ transference numbers and uniform and dense early-stage Li deposition.