Systematic investigation of the material basis, effectiveness and safety of Thesium chinense Turcz. and its preparation Bairui Granules against lung inflammation.

BACKGROUND: Thesium chinense Turcz. (Named as Bai Rui Cao in Chinese) and its preparations (e.g., Bairui Granules) have been used to treat inflammatory diseases, such as acute mastitis, lobar pneumonia, tonsillitis, coronavirus disease 2019 (COVID-19), and upper respiratory tract infection. However, the material basis, pharmacological efficiency, and safety have not been illustrated. METHODS: Anti-inflammatory activity-guided isolation of constituents has been performed using multiple column chromatography, and their structures were elucidated by NMR spectroscopy and ECD calculations. The inhibitory effects on lung inflammation and safety of the crude ethanol extract (CE), Bairui Granules (BG), and the purified active constituents were evaluated using lipopolysaccharide (LPS)-stimulated acute lung inflammation (ALI) mice model or normal mice. RESULTS: Seven new compounds (1-7) and fifty-six known compounds (8-63) were isolated from T. chinense, and fifty-four were reported from this plant for the first time. The new flavonoid glycosides 1-2, new fatty acids 4-5, new alkaloid 7 as well as the known constituents including flavonoid aglycones 8-11, lignans 46-54, alkaloids 34 and 45, coumarins 57, phenylpropionic acids 27, and simple aromatic compounds 39, 44 and 58 exhibited anti-inflammatory activity. Network pharmacology analysis indicated that anti-inflammation of T. chinense was attributed to flavonoids and alkaloids by regulating inflammation-related proteins (e.g., TNF, NF-κB, TGF-ß). Furthermore, constituents of T. chinense including kaempferol-3-O-glucorhamnoside (KN, also named as Bairuisu I, 19), astragalin (AG, Bairuisu II, 12), and kaempferol (KF, Bairuisu III, 8), as well as CE and BG could alleviate lung inflammation caused by LPS in mice by preventing neutrophils infiltration and the expression of the genes for pro-inflammatory cytokines NLRP3, caspase-1, IL-1ß, and COX-2. After a 28-day subacute toxicity test, BG at doses of 4.875 g/kg and 9.750 g/kg (equivalent to onefold and twofold the clinically recommended dose) and CE at a dose of 11.138 g/kg (equivalent to fourfold the clinical dose of BG) were found to be safe and non-toxic. CONCLUSIONS: The discovery of sixty-three constituents comprehensively illustrated the material basis of T. chinense. T. chinense and Bairui Granules could alleviate lung inflammation by regulating inflammation-related proteins and no toxicity was observed under the twofold of clinically used doses.

[Transcriptional regulation mechanism of differential accumulation of flavonoids in different varieties of Lonicera macranthoides based on metabonomics and transcriptomics].

This study aims to explore the molecular regulatory mechanism of the differential accumulation of flavonoids between 'Xianglei' and the wild type of Lonicera macranthoides. The flowers, stems, and leaves of the two varieties of L. macranthoides were collected. Ultra-performance liquid chromatography-mass spectrometry(UPLC-MS) and high-throughput sequencing(RNA-seq) were employed to screen out the differential flavonoids, key differentially expressed genes(DEGs) and transcription factors(TFs). Fourteen DEGs were randomly selected for verification by qRT-PCR. The results showed that a total of 17 differential flavonoids were obtained, including naringin chalcone, apigenin, and quercetin. The transcriptomic analysis predicted 19 DEGs associated with flavonoids, including 2 genes encoding chitin synthase(CHS) and 3 genes encoding chalcone isomerase(CHI). The regulatory network analysis and weighted gene co-expression network analysis(WGCNA) screen out the key enzyme genes CHS1, FLS1, and HCT regulating the accumulation of flavonoids. MYB12 and LBD4 may be involved in the biosynthesis of flavonoids by regulating the expression of key enzyme genes CHS1, FLS1, and HCT. The qRT-PCR and RNA-seq results were similar regarding the expression patterns of the 14 randomly selected DEGs. This study preliminarily analyzed the transcriptional regulatory mechanism for the differential accumulation of flavonoids in the two varieties of L. macranthoides and laid a foundation for further elucidating the regulatory effects of key enzyme genes and TFs on the accumulation of flavonoids.

Analysis of quality evaluation and optimal harvest period of Aurantii Fructus from different sources using UHPLC-Q-TOF-MS/MS.

INTRODUCTION: The active constituents in Aurantii Fructus sourced from different regions within Hunan Province exhibit variations, with certain samples demonstrating substandard quality. OBJECTIVES: The aim of this study is to conduct a comparative analysis of the chemical composition and quality of Aurantii Fructus from various sources, establish a robust methodology for quality evaluation, and determine the optimal harvesting period. MATERIALS AND METHODS: The components of Aurantii Fructus were qualitatively analyzed using a non-targeted metabolomics approach. Multivariate statistical analyses were conducted to identify potential markers, enabling qualitative and quantitative evaluation of the quality and optimal harvest period of Aurantii Fructus. RESULTS: Overall, 155 compounds were identified in Aurantii Fructus, with Huangpi exhibiting the highest number of components. Eleven potential markers were selected to assess the quality of Aurantii Fructus. The average content of Huangpi was the highest, indicating a high level of similarity. The samples' overall scores were ordered as follows: Huangpi > Xiangcheng > Choucheng > Daidai. Anren and Changde's Huangpi exhibited high contents, being rich in chemical components, resulting in favorable scores. Similarly, Changde's Xiangcheng displayed significant medicinal value. As the harvest time was delayed, there was an increase in fruit size, accompanied by thinner peels and a continuous decrease in the contents of potential markers. The best harvest period of Aurantii Fructus was within 1 week before and after the Lesser Heat. CONCLUSION: The present study establishes a precise and efficient method for evaluating the quality of Aurantii Fructus, thereby providing more comprehensive insights into its composition. This research lays the foundation for subsequent development and utilization of Aurantii Fructus.

Integrated network pharmacology and pharmacological investigations to explore the potential mechanism of Ding-Chuan-Tang against chronic obstructive pulmonary disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Ding-Chuan-Tang (Abbreviated as DCT) is frequently prescribed for treatment of respiratory diseases, including chronic obstructive pulmonary disease (COPD), which is characterized by coughing, wheezing, and chest tightness in traditional Chinese medicine (TCM). However, the potential mechanism of DCT has not been investigated. AIM OF STUDY: The aim of the study is to explore the efficiency of DCT in the treatment of COPD in vivo and in vitro, and to illustrate the possible mechanism against COPD. METHODS: COPD model was induced by exposure of mice to cigarette smoke (CS) for 16 weeks. Enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay, Western blot, etc., were used to explore the efficiency and mechanisms of DCT. Network pharmacology analysis, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, etc., was performed to explore the potential targets in the treatment of DCT on COPD. RESULTS: DCT significantly alleviated pulmonary pathological changes in mouse COPD model, and inhibited inflammatory response induced by CS and LPS in vivo and in vitro. Network pharmacology analysis suggested that DCT alleviated COPD via inhibiting inflammation by regulating PI3K-AKT pathway. In cell-based models, DCT suppressed the phosphorylation of PI3K and AKT, which further regulated its downstream targets Nrf2 and NF-κB, and inhibited inflammatory response. CONCLUSIONS: DCT effectively attenuated COPD in the mouse model induced by CS. The therapeutic mechanism of DCT against COPD was closely associated with the regulation of PI3K-AKT pathway and its downstream transcription factors, Nrf2 and NF-κB.

Realization of large-area ultraflat chiral blue phosphorene.

Blue phosphorene (BlueP), a theoretically proposed phosphorous allotrope with buckled honeycomb lattice, has attracted considerable interest due to its intriguing properties. Introducing chirality into BlueP can further enrich its physical and chemical properties, expanding its potential for applications. However, the synthesis of chiral BlueP remains elusive. Here, we demonstrate the growth of large-area BlueP films on Cu(111), with lateral size limited by the wafer dimensions. Importantly, we discovered that the BlueP is characterized by an ultraflat honeycomb lattice, rather than the prevailing buckled structure, and develops highly ordered spatial chirality plausibly resulting from the rotational stacking with the substrate and interface strain release, as further confirmed by the geometric phase analysis. Moreover, spectroscopic measurements reveal its intrinsic metallic nature and different characteristic quantum oscillations in the image-potential states, which can be exploited for a range of potential applications including polarization optics, spintronics, and chiral catalysis.

Comparative evaluation of four Lycium barbarum cultivars on NaIO3-induced retinal degeneration mice via multivariate statistical analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: The fruit of Lycium barbarum L. (goji berry) is a traditional Chinese medicine and is often used to improve vision. While various goji cultivars may differentially treat retinal degeneration, however their comparative effectiveness remains unclear. AIM OF THE STUDY: To evaluate the protective effects of four goji cultivars on NaIO3-induced retinal degeneration mouse model and identify the most therapeutically potent cultivar. MATERIALS AND METHODS: The principal compounds in the extracts of four goji cultivars were characterized by UPLC-Q-TOF/MS. A retinal degeneration mouse model was established via NaIO3 injection. Dark-light transition and TUNEL assays were used to assess visual function and retinal apoptosis. The levels of antioxidative, inflammatory, and angiogenic markers in serums and eyeballs were measured. Hierarchical cluster analysis, principal component analysis and partial least squares-discriminant analysis were used to objectively compare the treatment responses. RESULTS: Sixteen compounds were identified in goji berry extracts. All goji berry extracts could reverse NaIO3-induced visual impairment, retinal damage and apoptosis. The samples from the cultivar of Ningqi No.1 significantly modulated oxidative stress, inflammation, and vascular endothelial growth factor levels, which are more effectively than the other cultivars based on integrated multivariate profiling. CONCLUSION: Ningqi No.1 demonstrated a stronger protective effect on mouse retina than other goji cultivars, and is a potential variety for further research on the treatment of retinal degeneration.

Methotrexate Chemotherapy Causes Growth Impairments, Vitamin D Deficiency, Bone Loss, and Altered Intestinal Metabolism-Effects of Calcitriol Supplementation.

Vitamin D deficiency or insufficiency is prevalent in childhood cancer patients and survivors after chemotherapy; further studies are needed to investigate the underlying aetiology and effectiveness of vitamin D supplementation in preventing chemotherapy-induced bone loss. This study used a rat model of treatment with antimetabolite methotrexate to investigate whether methotrexate chemotherapy causes vitamin D deficiency and if vitamin D supplementation attenuates the resultant bone loss. Methotrexate treatment (five daily injections) decreased serum vitamin D levels (from 52 to <30 ng/mL), reduced body and bone lengthening and tibial trabecular bone volume, and altered intestinal vitamin D metabolism, which was associated with intestinal mucosal damage known to cause malabsorption of nutrients, including dietary vitamin D and calcium. During the early stage after chemotherapy, mRNA expression increased for vitamin D activation enzyme CYP27B1 and for calcium-binding protein TRPV6 in the intestine. During the intestinal healing stage, expression of vitamin D catabolism enzyme CYP24 increased, and that of TRPV6 was normalised. Furthermore, subcutaneous calcitriol supplementation diminished methotrexate-induced bone loss due to its effect suppressing methotrexate-induced increased bone resorption. Thus, in young rats, methotrexate chemotherapy causes vitamin D deficiency, growth impairments, bone loss, and altered intestinal vitamin D metabolism, which are associated with intestinal damage, and vitamin D supplementation inhibits methotrexate-induced bone loss.

Transcription factors MdMYC2 and MdMYB85 interact with ester aroma synthesis gene MdAAT1 in apple.

Volatile esters in apple (Malus domestica) fruit are the critical aroma components determining apple flavor quality. While the exact molecular regulatory mechanism remains unknown, jasmonic acid (JA) plays a crucial role in stimulating the synthesis of ester aromas in apples. In our study, we investigated the effects of methyl jasmonate (MeJA) on the production of ester aroma in apples. MeJA treatment significantly increased ester aroma synthesis, accompanied by the upregulation of several genes involved in the jasmonate pathway transduction. Specifically, expression of the gene MdMYC2, which encodes a transcription factor associated with the jasmonate pathway, and the R2R3-MYB transcription factor gene MdMYB85 increased upon MeJA treatment. Furthermore, the essential gene ALCOHOL ACYLTRANSFERASE 1 (MdAAT1), encoding an enzyme responsible for ester aroma synthesis, showed increased expression levels as well. Our investigation revealed that MdMYC2 and MdMYB85 directly interacted with the promoter region of MdAAT1, thereby enhancing its transcriptional activity. In addition, MdMYC2 and MdMYB85 directly bind their promoters and activate transcription. Notably, the interaction between MdMYC2 and MdMYB85 proteins further amplified the regulatory effect of MdMYB85 on MdMYC2 and MdAAT1, as well as that of MdMYC2 on MdMYB85 and MdAAT1. Collectively, our findings elucidate the role of the gene module consisting of MdMYC2, MdMYB85, and MdAAT1 in mediating the effects of JA and promoting ester aroma synthesis in apples.

Rosafuningensis (Rosaceae), a new species from Yunnan, China.

A new species Rosafuningensis and its variant R.funingensisf.rosea, both collected from Yunnan Province, China, are, for the first time, documented and illustrated in this study. Morphological analysis in comparison with two related species in the wild, R.gigantea and R.rubus, presents distinguishable features through leaf surfaces, inflorescences and the shape of styles. R.funingensis leaf surfaces are abaxially villous, purple-red, pale green when mature, adaxially glabrous, dark green; inflorescences solitary or 2-5(7) in corymbose cyme; and styles connate into a column or not, exserted.

[Mining and identification of members of MYB transcription factor family in Lonicera macranthoides].

As a large family of transcription factors, the MYB family plays a vital role in regulating flower development. We studied the MYB family members in Lonicera macranthoides for the first time and identified three sequences of 1R-MYB, 47 sequences of R2R3-MYB, two sequences of 3R-MYB, and one sequence of 4R-MYB from the transcriptome data. Further, their physicochemical properties, conserved domains, phylogenetic relationship, protein structure, functional information, and expression were analyzed. The results show that the 53 MYB transcription factors had different conserved motifs, physicochemical properties, structures, and functions in wild type and 'Xianglei' cultivar of L. macranthoides, indicating their conservation and diversity in evolution. The transcript level of LmMYB was significantly different between the wild type and 'Xianglei' cultivar as well as between flowers and leaves, and some genes were specifically expressed. Forty-three out of 53 LmMYB sequences were expressed in both flowers and leaves, and 9 of the LmMYB members showed significantly different transcript levels between the wild type and 'Xianglei' cultivar, which were up-regulated in the wild type. The results provide a theoretical basis for further studying the specific functional mechanism of the MYB family.

The sensitivity of mechanical properties and pore structures of Beishan granite to large variation of temperature in nuclear waste storage sites.

Granite is the host rock of the Beishan Underground Research Laboratory (URL) for geological disposal of high-level radioactive waste in China. The mechanical behavior of Beishan granite is the key in determining whether the repository can serve safely for a long time. The surrounding rock of the repository will be exposed to thermal environment induced by radionuclide decay, resulting in significant changes in the physical and mechanical properties of the Beishan granite. This study investigated the pore structure and mechanical properties of Beishan granite after thermal treatment. The T2 spectrum distribution, pore size distribution, porosity, and magnetic resonance imaging (MRI) were obtained through nuclear magnetic resonance (NMR); uniaxial compressive strength (UCS) and acoustic emission (AE) signal characteristic of granite were investigated through uniaxial compression tests. The results showed that high temperature significantly affected the T2 spectrum distribution, pore size distribution, porosity, compressive strength, and elastic modulus of granite, and porosity gradually increases, whereas the strength and elastic modulus gradually decline with increasing temperature. The porosity of granite has a linear relationship with UCS and elastic modulus, indicating that the essential mechanism for the deterioration of macroscopic mechanical properties lies in changes of microstructure. In addition, the thermal damage mechanism of granite was revealed, and a damage variable was defined based on porosity and uniaxial compressive strength.

[Three-dimensional multi-component analysis of Aurantii Fructus quality and research on influencing factors].

The present study explored the consistency of the content proportions of active components of Aurantii Fructus and analyzed the influencing factors based on three-dimensional multi-component analysis. A total of 839 Aurantii Fructus samples in 65 research articles were analyzed using the three-dimensional multi-component analysis mode. The content data of flavonoid components(naringin, hesperidin, neohesperidin, narirutin, and nobiletin), coumarin components(meranzin and gluconolactone), and alkaloid(synephrine) in 386 samples which met the criteria of 2020 edition of the Chinese Pharmacopoeia were extracted and adjusted to percentages, and the content ratios between components were calculated. The influencing factors of Aurantii Fructus quality were analyzed. The results showed content ratios of components as follows: neohesperidin∶naringin in the range of 0.4-1.2; narirutin∶naringin in the range of 0.02-0.16; hesperidin∶naringin in the range of 0.01-0.3; nobiletin∶naringin in the range of 0.000 588 3-0.069 68; synephrine∶naringin in the range of 0.02-0.042; gluconolactone∶naringin in the range of 0.001-0.01; meranzin∶naringin in the range of 0.000 4-0.035. The quality of Aurantii Fructus was closely related to the origin, variety, harvesting time, and processing method of medicinal materials. Harvesting time had a greater impact on the quality of Aurantii Fructus, and the origin and variety had a certain impact on the quality of Aurantii Fructus. The findings of this study indicated that the ratios between flavonoid components, flavonoids and coumarin components, and flavonoids and alkaloids fluctuated. The production base should optimize the varieties, harvesting period, and processing methods of Aurantii Fructus to provide a scientific basis for the production of high-quality Aurantii Fructus.

Hydrothermal Aging Alleviates the Phosphorus Poisoning of Cu-SSZ-39 Catalysts for NH3-SCR Reaction.

As a new type of catalyst with the potential for commercial application in NOx removal from diesel engine exhausts, Cu-SSZ-39 catalysts must have excellent resistance to complex and harsh conditions. In this paper, the effects of phosphorus on Cu-SSZ-39 catalysts before and after hydrothermal aging treatment were investigated. Compared with fresh Cu-SSZ-39 catalysts, phosphorus poisoning significantly decreased the low-temperature NH3-SCR catalytic activity. However, such activity loss was alleviated by further hydrothermal aging treatment. To reveal the reason for this interesting result, a variety of characterization techniques including NMR, H2-TPR, X-ray photoelectron spectroscopy, NH3-TPD, and in situ DRIFTS measurements were employed. It was found that Cu-P species produced by phosphorus poisoning decreased the redox ability of active copper species, resulting in the observed low-temperature deactivation. After hydrothermal aging treatment, however, Cu-P species partly decomposed with the formation of active CuOx species and a release of active copper species. As a result, the low-temperature NH3-SCR catalytic activity of Cu-SSZ-39 catalysts was recovered.

Manipulation of Particle/Cell Based on Compressibility in a Divergent Microchannel by Surface Acoustic Wave.

The mechanical properties (compressibility or deformability) of cells are closely related to their death, migration, and differentiation. Accurate separation and manipulation of bioparticles based on these mechanical properties are still a challenging in the field of acoustofluidics. In this work, based on surface acoustic waves (SAW) and divergent microchannels, we developed a new method for separating and detecting particles or cells with different compressibility. The difference in acoustic radiation force (Fr) caused by compressibility are gradually amplified and accumulated by decreasing the flow velocity, and they are finally reflected in the particle migration distance. During the transverse migration process, the alternating dominance of the acoustic radiation force and the Stokes resistance force (Fs) drives the particles to create three typical migration patterns: intermittent migration, compound migration, and near-wall migration. In the present tilted SAW device, a 91% separation success rate of ∼10 µm polystyrene (PS) and polydimethylsiloxane (PDMS) particles can be achieved by optimizing the acoustic field input power and the fluid velocity. The application potential of the present divergent microchannel is validated by separating the myelogenous leukemia cell K562 and the natural killer cell NK92 that have similar densities and sizes (∼15 µm) but different compressibility. The results of this work are expected to provide valuable insights into the acoustofluidics separation and detection of the cells that are with different compressibility.

Plasma Meets MOFs: Synthesis, Modifications, and Functionalities.

As a porous and network materials consisting of metals and organic ligands, metal-organic frameworks (MOFs) have become one of excellent crystalline porous materials and play an important role in the era about materials science. Plasma, as a useful tool for stimulating efficient reactions under many conditions, and the plasma-assisted technology gets more attractions and endows MOFs more properties. Based on its feature, the research about the modifications and functionalities of MOFs have been developing a certain extent. This review contains a description of the methods for plasma-assisted modification and synthesis of MOFs, with specifically focusing on the plasma-assisted potential for modifications and functionalities of MOFs. The different applications of plasma-assisted MOFs were also presented.

Nano-sized alumina supported palladium catalysts for methane combustion with excellent thermal stability.

Pd/Al2O3 catalysts supported on Al2O3 of different particle sizes were synthesized and applied in methane combustion. These catalysts were systematically characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), high resolution-transmission electron microscopy (HR-TEM), high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), H2-temperature-programmed reduction (H2-TPR), O2-temperature-programmed oxidation (O2-TPO), X-ray photoelectron spectroscopy (XPS), and X-ray absorption fine structure (XAFS). The characterization results indicated that nano-sized Al2O3 enabled the uniform dispersion of palladium nanoparticles, thus contributing to the excellent catalytic performance of these nano-sized Pd/Al2O3 catalysts. Among them, Pd/Al2O3-nano-10 (Pd/Al2O3 supported by alumina with an average particle size of 10 nm) showed superior catalytic activity and stability for methane oxidation under harsh practical conditions. It maintained excellent catalytic performance for methane oxidation for 50 hr and remained stable even after harsh hydrothermal aging in 10 vol.% steam at 800°C for 16 hr. Characterization results revealed that the strong metal-support interactions and physical barriers provided by Al2O3-nano-10 suppressed the coalescence ripening of palladium species, and thus contributed to the superior sintering resistance of the Pd/Al2O3-nano-10 catalyst.

Mining and identification of members of MYB transcription factor family in Lonicera macranthoides / 中国中药杂志

As a large family of transcription factors, the MYB family plays a vital role in regulating flower development. We studied the MYB family members in Lonicera macranthoides for the first time and identified three sequences of 1R-MYB, 47 sequences of R2R3-MYB, two sequences of 3R-MYB, and one sequence of 4R-MYB from the transcriptome data. Further, their physicochemical properties, conserved domains, phylogenetic relationship, protein structure, functional information, and expression were analyzed. The results show that the 53 MYB transcription factors had different conserved motifs, physicochemical properties, structures, and functions in wild type and 'Xianglei' cultivar of L. macranthoides, indicating their conservation and diversity in evolution. The transcript level of LmMYB was significantly different between the wild type and 'Xianglei' cultivar as well as between flowers and leaves, and some genes were specifically expressed. Forty-three out of 53 LmMYB sequences were expressed in both flowers and leaves, and 9 of the LmMYB members showed significantly different transcript levels between the wild type and 'Xianglei' cultivar, which were up-regulated in the wild type. The results provide a theoretical basis for further studying the specific functional mechanism of the MYB family.

Three-dimensional multi-component analysis of Aurantii Fructus quality and research on influencing factors / 中国中药杂志

The present study explored the consistency of the content proportions of active components of Aurantii Fructus and analyzed the influencing factors based on three-dimensional multi-component analysis. A total of 839 Aurantii Fructus samples in 65 research articles were analyzed using the three-dimensional multi-component analysis mode. The content data of flavonoid components(naringin, hesperidin, neohesperidin, narirutin, and nobiletin), coumarin components(meranzin and gluconolactone), and alkaloid(synephrine) in 386 samples which met the criteria of 2020 edition of the Chinese Pharmacopoeia were extracted and adjusted to percentages, and the content ratios between components were calculated. The influencing factors of Aurantii Fructus quality were analyzed. The results showed content ratios of components as follows: neohesperidin∶naringin in the range of 0.4-1.2; narirutin∶naringin in the range of 0.02-0.16; hesperidin∶naringin in the range of 0.01-0.3; nobiletin∶naringin in the range of 0.000 588 3-0.069 68; synephrine∶naringin in the range of 0.02-0.042; gluconolactone∶naringin in the range of 0.001-0.01; meranzin∶naringin in the range of 0.000 4-0.035. The quality of Aurantii Fructus was closely related to the origin, variety, harvesting time, and processing method of medicinal materials. Harvesting time had a greater impact on the quality of Aurantii Fructus, and the origin and variety had a certain impact on the quality of Aurantii Fructus. The findings of this study indicated that the ratios between flavonoid components, flavonoids and coumarin components, and flavonoids and alkaloids fluctuated. The production base should optimize the varieties, harvesting period, and processing methods of Aurantii Fructus to provide a scientific basis for the production of high-quality Aurantii Fructus.

Si/Al Ratio Determines the SCR Performance of Cu-SSZ-13 Catalysts in the Presence of NO2.

A comparative study was performed to investigate the NH3-selective catalytic reduction (SCR) reaction activity of Cu-SSZ-13 zeolites having Si/Al ratios (SARs) of 5, 18, and 30. Remarkably, the Cu-SSZ-13 zeolite catalysts exhibited completely opposite behaviors as a function of SAR under standard SCR (SSCR) and fast SCR (FSCR) reaction atmospheres. Under SSCR conditions, the NOx conversion increased as expected with the decreasing SAR. Under FSCR conditions, however, the NOx conversion decreased as the SAR decreased, contrary to expectations. In this study, based on characterization of the catalysts by X-ray diffraction, transmission electron microscopy, electron paramagnetic resonance, H2-temperature-programmed reduction, temperature-programmed desorption, and diffuse reflectance infrared Fourier transform spectroscopy, together with theoretical calculations, the authors found that the amount of Brønsted acid sites goes up while the SAR goes down, leading to an increase in the accumulation of NH4NO3 under FSCR reaction conditions. Moreover, the accumulated NH4NO3 is of greater stability for those low SAR Cu-SSZ-13 catalysts. These two reasons cause the FSCR performance of Cu-SSZ-13 to decrease with a decrease in SAR. As a result, the NO2 effect on SCR activity changes from promotion to inhibition as the SAR decreases.