Maxim. (Rutaceae) is a popular food additive and traditional Chinese herbal medicine commonly named
in China. This plant is widely distributed in Asian countries. The aim of this paper is to provide ...a systematic review on the traditional usages, botany, phytochemistry, pharmacology, pharmacokinetics, and toxicology of this plant. Furthermore, the possible development and perspectives for future research on this plant are also discussed. To date, over 140 compounds have been isolated and identified from
, including alkaloids, terpenoids, flavonoids, and free fatty acids. The extracts and compounds have been shown to possess wide-ranging biological activity, such as anti-inflammatory and analgesic effects, antioxidant and anti-tumor effects, antibacterial and antifungal effects, as well as regulatory effects on the gastrointestinal system and nervous system, and other effects. As a traditional herbal medicine,
has been widely used to treat many diseases, especially digestive disorders, toothache, stomach ache, and diarrhea. Many traditional usages of this plant have been validated by present investigations. However, further research elucidating the structure-function relationship among chemical compounds, understanding the mechanism of unique sensation, as well as exploring new clinical effects and establishing criteria for quality control for
should be further studied.
Besides the conventional carbon sources, acetyl-CoA has recently been shown to be generated from acetate in various types of cancers, where it promotes lipid synthesis and tumour growth. The ...underlying mechanism, however, remains largely unknown. We find that acetate induces a hyperacetylated state of histone H3 in hypoxic cells. Acetate predominately activates lipogenic genes ACACA and FASN expression by increasing H3K9, H3K27 and H3K56 acetylation levels at their promoter regions, thus enhancing de novo lipid synthesis, which combines with its function as the metabolic precursor for fatty acid synthesis. Acetyl-CoA synthetases (ACSS1, ACSS2) are involved in this acetate-mediated epigenetic regulation. More importantly, human hepatocellular carcinoma with high ACSS1/2 expression exhibit increased histone H3 acetylation and FASN expression. Taken together, this study demonstrates that acetate, in addition to its ability to induce fatty acid synthesis as an immediate metabolic precursor, also functions as an epigenetic metabolite to promote cancer cell survival under hypoxic stress.
To avoid the interference of blue background fluorescence from food substrates, red-emitting carbon dots (R-CDs) were designed for the detection of brilliant blue FCF (BB). The synthesized R-CDs ...exhibited good photoluminescence stability and emitted red fluorescence at 627 nm. BB exhibits a linear fluorescence quenching effect on R-CDs in the range of 0.2–40 μM with a limit of detection of 84.00 nM. The fluorescence quenching mechanism can be explained by the inner filter effect. Food samples showed no fluorescence signals in the red region. Common substrates also had no visible effect on the fluorescence of the R-CDs. The developed method is practical for the detection of BB in cocktails and beverages without sample pretreatment. Using R-CDs as fluorescent probes, a sensitive, selective, and accurate BB detection method was developed.
•Red-emitting carbon dots are designed for detecting brilliant blue FCF.•The interference of background fluorescence from complex food substrates is avoided.•A fast, sensitive and accurate detection method towards brilliant blue FCF.•Drinks can be detected simply without any pretreatment.
Summary
Raffinose is thought to play an important role in plant tolerance of abiotic stress. We report here that maize HEAT SHOCK FACTOR A2 (ZmHSFA2) and HEAT SHOCK BINDING PROTEIN 2 (ZmHSBP2) ...physically interact with each other and antagonistically modulate expression of GALACTINOL SYNTHASE2 (ZmGOLS2) and raffinose biosynthesis in transformed maize protoplasts and Arabidopsis plants. Overexpression of ZmHSFA2 in Arabidopsis increased the expression of Arabidopsis AtGOLS1, AtGOLS2 and AtRS5 (RAFFINOSE SYNTHASE), increased the raffinose content in leaves and enhanced plant heat stress tolerance. Contrary to ZmHSFA2, overexpression of ZmHSBP2 in Arabidopsis decreased expression of AtGOLS1, AtGOLS2 and AtRS5, decreased the raffinose content in leaves and reduced plant heat stress tolerance. ZmHSFA2 and ZmHSBP2 also interact with their Arabidopsis counterparts AtHSBP and AtHSFA2 as determined using bimolecular fluorescence complementation assays. Furthermore, endogenous ZmHSBP2 and Rluc, controlled by the ZmHSBP2 promoter, are transcriptionally activated by ZmHSFA2 and inhibited by ZmHSBP2 in maize protoplasts. These findings provide insights into the transcriptional regulation of raffinose biosynthetic genes, and the tolerance their product confers to plant heat stress.
Significance Statement
Supraoptimal temperature is a major threat to plant productivity and survival. We found that maize HEAT SHOCK FACTOR A2 (HSFA2) and HEAT SHOCK BINDING PROTEIN 2 (HSBP2) antagonistically modulate expression of the GALACTINOL SYNTHASE gene in maize protoplast cells, and regulate both raffinose biosynthesis and plant heat stress tolerance in Arabidopsis. In addition, ZmHSBP2 is transcriptionally activated by ZmHSFA2 and inhibited by its own protein ZmHSBP2, elucidating control of protective oligosaccharide production in response to this abiotic stress.
The outbreak of coronavirus disease 2019 (COVID-19) is a global health emergency. Various omics results have been reported for COVID-19, but the molecular hallmarks of COVID-19, especially in those ...patients without comorbidities, have not been fully investigated. Here we collect blood samples from 231 COVID-19 patients, prefiltered to exclude those with selected comorbidities, yet with symptoms ranging from asymptomatic to critically ill. Using integrative analysis of genomic, transcriptomic, proteomic, metabolomic and lipidomic profiles, we report a trans-omics landscape for COVID-19. Our analyses find neutrophils heterogeneity between asymptomatic and critically ill patients. Meanwhile, neutrophils over-activation, arginine depletion and tryptophan metabolites accumulation correlate with T cell dysfunction in critical patients. Our multi-omics data and characterization of peripheral blood from COVID-19 patients may thus help provide clues regarding pathophysiology of and potential therapeutic strategies for COVID-19.
Here we demonstrate an anionic porphyrin, protoporphyrin IX (PPIX), as a parallel G-quadruplex-specific fluorescent probe for monitoring DNA structural changes and utilize it to develop a DNA-based ...K+ sensor. The interactions of PPIX with different DNA structures in K+ or Na+ solution are investigated by using circular dichroism, fluorescence, and UV−vis spectroscopy. The observations reveal that PPIX has an ∼100-fold selectivity for parallel G-quadruplexes against duplexes and antiparallel G-quadruplexes. Meanwhile, the fluorescence intensity of PPIX increases by over 10-fold upon binding to parallel G-quadruplexes. On the basis of the selectivity and fluorescence property of PPIX, we introduce a facile, label-free approach to monitoring DNA structural changes via fluorescence signal readout that is tuned by PPIX binding and release. To illustrate it, we utilize PPIX and a G-rich DNA PS2.M to construct a fluorescent K+ sensor based on an antiparallel-to-parallel conformation transition of the G-quadruplex. PS2.M adopts an antiparallel quadruplex structure in Na+ solution, whereas it gradually converts into a parallel G-quadruplex upon addition of increasing K+. This conformational change is indicated by a sharp increase in the fluorescence intensity of PPIX, owing to the good ability of PPIX to discriminate parallel G-quadruplexes from antiparallel ones. Even in the presence of 100 mM Na+, such a “turn-on” fluorescent sensor can respond to low concentrations of K+, with a limit of detection (0.5 mM) for K+ analysis. In addition, this sensor exhibits a high selectivity for K+ over other common metal ions, which ensures its practical applications to real samples. These results reveal that PPIX is promising for use as a specific DNA structural probe in sensing applications.
By systematically summarizing horizontal well fracturing technology abroad for shale oil and gas reservoirs since the “13th Five-Year Plan”, this article elaborates new horizontal well fracturing ...features in 3D development of stacked shale reservoirs, small well spacing and dense well pattern, horizontal well re-fracturing, fracturing parameters optimization and cost control. In light of requirements on horizontal well fracturing technology in China, we have summarized the technological progress in simulation of multi-fracture propagation, horizontal well frac-design, electric-drive fracturing equipment, soluble tools and low-cost downhole materials and factory-like operation. On this basis, combined with the demand analysis of horizontal well fracturing technology in the “14th Five-Year Plan” for unconventional shale oil and gas, we suggest strengthening the research and development in the following 7 aspects: (1) geology-engineering integration; (2) basic theory and design optimization of fracturing for shale oil and gas reservoirs; (3) development of high-power electric-drive fracturing equipment; (4) fracturing tool and supporting equipment for long horizontal section; (5) horizontal well flexible-sidetracking drilling technology for tapping remaining oil; (6) post-frac workover technology for long horizontal well; (7) intelligent fracturing technology.
Unusual nuclear quantum effects may emerge near noble metal nanostructures such as squeezed vibrational states in molecular junctions and plasmonic resonance energy transfer in the infrared domain. ...Herein, nuclear quantum effects near heavy metals are studied by nuclear–electronic orbital density functional theory (NEO-DFT) with an effective core potential. For a quantum proton sandwiched between a pair of gold tips modeled by two Au6 clusters, NEO-DFT calculations suggest that the quantum proton density can be squeezed as the tip distance decreases. For an HF molecule placed near a one-dimensional Au nanowire composed of up to 34 Au atoms, real-time NEO time-dependent density functional theory (RT-NEO-TDDFT) shows that the infrared plasmonic motion within the Au nanowire may resonantly transfer electronic energy to the HF proton vibrational stretch mode. Overall, these calculations illustrate the advantages of the NEO approach for probing nuclear quantum effects, such as squeezed proton vibrational states and infrared plasmonic resonance energy transfer.
Second-order nonlinear metasurfaces have proven their ability to efficiently convert the frequency of incident signals over subwavelength thickness. However, the availability of second-order ...nonlinear materials for such metasurfaces has so far been limited to III-V semiconductors, which have low transparency in the visible and impose constraints on the excitation geometries due to the lack of diagonal second-order susceptibility components. Here we propose a new design concept for second-order nonlinear metasurfaces on a monolithic substrate, which is not limited by the availability of thin crystalline films and can be applied to any non-centrosymmetric material. We exemplify this concept in a monolithic Lithium Niobate metasurface with cylinder-shaped corrugations for enhanced field confinement. By optimizing the geometrical parameters, we show enhanced second harmonic generation from a near-infrared pump beam with conversion efficiency above 10
using 1 GW/cm
pump intensity. Our approach enables new opportunities for practical designs of generic metasurfaces for nonlinear and quantum light sources.
Under the catalysis of Rh2(OAc)4 (10 mol%) and (±)‐Me‐Pybox (20 mol%) in 1,2‐DCE at 80 °C, the homocoupling/4+1 cycloaddition cascade of diazobarbiturates with diazopyrazolones proceeded readily and ...provided spirobarbiturates in 32–88% chemical yields. The chemical structure of the obtained spirobarbiturates was identified by X‐ray diffraction analysis.
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