Activation of dinitrogen (N2, 78 %) and dioxygen (O2, 21 %) has fascinated chemists and biochemists for decades. The industrial conversion of N2 into ammonia requires extremely high temperatures and ...pressures. Herein we report the first example of N2 and O2 cleavage by a uranium complex, N(CH2CH2NPiPr2)3U2(TMEDA), under ambient conditions without an external reducing agent. The N2 triple bond breaking implies a UIII–PIII six‐electron reduction. The hydrolysis of the N2 reduction product allows the formation of ammonia or nitrogen‐containing organic compounds. The interaction between UIII and PIII in this molecule allows an eight‐electron reduction of two O2 molecules. This study establishes that the combination of uranium and a low‐valent nonmetal is a promising strategy to achieve a full N2 and O2 cleavage under ambient conditions, which may aid the design of new systems for small molecules activation.
N2 and O2 cleavage was achieved under ambient conditions via a cooperativity between UIII and PIII centers. The N2 triple bond breaking implies a UIII–PIII six‐electron reduction. The interaction between UIII and PIII in this molecule allows an eight‐electron reduction of two O2 molecules. This study shows that metal–ligand cooperation is a promising strategy for the activation of small molecules.
Due to the influence of extreme weather, the environment in China's main cotton-producing areas is prone to drought stress conditions, which affect the growth and development of cotton and lead to a ...decrease in cotton yield. In this study, 188 upland cotton germplasm resources were phenotyped for data of 8 traits (including 3 major yield traits) under drought conditions in three environments for two consecutive years. Correlation analysis revealed significant positive correlations between the three yield traits. Genetic analysis showed that the estimated heritability of the seed cotton index (SC) under drought conditions was the highest (80.81%), followed by that of boll weight (BW) (80.64%) and the lint cotton index (LC) (70.49%) With genome-wide association study (GWAS) analysis, a total of 75 quantitative trait loci (QTLs) were identified, including two highly credible new QTL hotspots. Three candidate genes (Gh_D09G064400, Gh_D10G261000 and Gh_D10G254000) located in the two new QTL hotspots, QTL51 and QTL55, were highly expressed in the early stage of fiber development and showed significant correlations with SC, LC and BW. The expression of three candidate genes in two extreme materials after drought stress was analyzed by qRT-PCR, and the expression of these two materials in fibers at 15, 20 and 25 DPA. The expression of these three candidate genes was significantly upregulated after drought stress and was significantly higher in drought-tolerant materials than in drought-sensitive materials. In addition, the expression levels of the three candidate genes were higher in the early stage of fiber development (15 DPA), and the expression levels in drought-tolerant germplasm were higher than those in drought-sensitive germplasm. These three candidate genes may play an important role in determining cotton yield under drought conditions. This study is helpful for understanding the regulatory genes affecting cotton yield under drought conditions and provides germplasm and candidate gene resources for breeding high-yield cotton varieties under these conditions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Path coefficient, p test value and R2 value of policy influence ecosystem.
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•Policy implementation is a key element of ecological governance.•Policy factors play a important role in ...the evolution of the Tianzhu ecosystem.•The adjustment of planting industry is the key to ecological improvement.•To strengthen the intensity of grazing and other animal husbandry policy research.
Policy is a key element of ecological governance, however, insufficient attention has been given to how different policies and regulations in a systematic way affect ecosystem processes and functions. This study evaluated the impact of ecological policies in the national key ecological functional areas (NKEFAs) since 1990, taking Tianzhu County as a case study. We first evaluated the change in policy intensity through quantitative analysis of policy texts, then analyzed the change in the ecosystems with carbon storage, habitat quality, ecosystem service and water conservation. Finally, the partial least squares (PLS) was used to quantify the effective path for and effect of policies on the ecosystem through adjustments in agriculture, animal husbandry and population. The results showed that policies have a significant direct impact on the agricultural planting industry, animal husbandry and population size and structure, and have a significant indirect impact on the whole ecosystem. The research demonstrated the usefulness of applying PLS-SEM and ecosystem function indicators to evaluate the impact of ecological governance policies on ecosystems in NKEFAs. The research can provide reference for the ecological policy making of NKEFAs.
et Rhizoma is regarded as one of the most popular and commonly used herbal medicines and has been used in traditional Chinese medicine (TCM) prescriptions for over 2000 years. Pentacyclic triterpene ...saponins are common secondary metabolites in these plants, which are synthesized via the isoprenoid pathway to produce a hydrophobic triterpenoid aglycone containing a hydrophilic sugar chain. This paper systematically summarizes the chemical structures of triterpene saponins in
et Rhizoma and reviews and updates their main biological activities studies. Furthermore, the solubilization characteristics, influences, and mechanisms of
et Rhizoma are elaborated. Solubilization of the triterpene saponins from
et Rhizoma occurs because they contain the nonpolar sapogenin and water-soluble sidechain. The possible factors affecting the solubilization of
et Rhizoma are mainly other crude drugs and the pH of the decoction. Triterpene saponins represented by glycyrrhizin from
et Rhizoma characteristically form micelles due to amphiphilicity, which makes solubilization possible. This overview provides guidance regarding a better understanding of
et Rhizoma and its TCM compatibility, alongside a theoretical basis for the further development and utilization of
et Rhizoma.
The application of nanotechnology for antimicrobial delivery has capacity to improve antibacterial efficacy. Currently, the usage of various inorganic and organic carriers, such as metal ions, ...nano-silicon and surfactants, might increase the potential toxicity of nanoparticles and make their clinical transformation more difficult. Herein, a nano-delivery system was constructed by direct self-assembly of antibacterial phytochemicals (berberine and rhein) originated from traditional Chinese medicine Coptis chinensis Franch. and Rheum palmatum L., respectively. Combining X-ray single crystal diffraction, nuclear magnetic resonance and other spectra characterizations, the stacked structure of nanoparticles was profoundly demonstrated. Briefly, rhein acted as the layered backbone and berberine embedded in it. In vitro bacteriostasis experiment showed the minimum bactericidal concentration of nanoparticles was 0.1 μmol/mL, which was lower than that of berberine and rhein. The results of confocal laser scanning microscope, biofilm quantitive assay and scanning electron microscopy indicated that nanoparticles had strong inhibitory effects on Staphylococcus aureus biofilm. More importantly, transmission electron microscopy and mass spectra indicated the further bacteriostatic mechanism of nanoparticles. Meanwhile, the nanoparticles had well biocompatibility and safety. Current study will open up new prospect that the design of self-assemblies between active phytochemicals can be originated from traditional Chinese medicine combination.
Ber-Rhe nanoparticles (NPs) were formed by direct self-assembly of Ber and Rhe. Combining X-ray single crystal diffraction and spectral analyses, the self-assembly mechanism of NPs had been demonstrated. Meanwhile, Ber–Rhe NPs demonstrated the inhibitory effect against Staphylococcus aureus by destroying the cell wall & membrane and cleaning the biofilm. Display omitted
Diarrhea-predominant irritable bowel syndrome (IBS-D) is one common chronic functional disease of the digestive system with limited treatments. The microbiota–gut–brain axis (MGBA) has a central ...function in the pathogeny of IBS-D, which includes the participation of many various factors, such as brain-gut peptides (BGPs), immune inflammation, and intestinal flora. Inspired by the drug combination in traditional Chinese medicine (TCM), our previous study discovered that berberine (BBR) and baicalin (BA) could form natural self-assemblies as BA-BBR nanoparticles (BA-BBR NPs) and showed synergistic effects against IBS-D. Here, we investigated the synergistic effects of BA-BBR NPs on IBS-D model mice induced by chronic restraint stress plus Senna alexandrina Mill decoction with the influence on MGBA. BA-BBR NPs showed the best therapeutic effect on improving visceral hypersensitivity and diarrhea on IBS-D model mice, compared with BBR, BA, and BA/BBR mixture. Furthermore, BA-BBR NPs significantly (
P
<0.05) reduced the levels of 5-hydroxytryptamine (5-HT), vasoactive intestinal polypeptide (VIP) and choline acety transferase (CHAT) in colon tissues or of serum from BGPs; it lowered the expressions of the nuclear factor kappa-B (NF-κB) in colon tissues and changed the levels of basophil granulocyte (BASO) and leukomonocyte (LYMPH) in whole blood from immune inflammation; it altered the intestinal flora of Bacteroidia, Deferribacteres, Verrucomicrobia, Candidatus_Saccharibacteria, and Cyanobacteria from intestinal flora. In conclusion, BA-BBR NPs, after forming the natural self-assembly between BBR and BA, promoted the synergistic effect on IBS-D mice than the sum of BBR and BA effects, based to the formation of self-assemblies rather than the simple mixing. It further proved that synergistic effect of BA-BBR NPs on IBS-D mice might be related to BGPs, immune inflammation, and intestinal flora from three important interrelated components of MGBA. This study will provide a novel idea for the interpretation of TCM compatibility theory and provide the basis for BA-BBR NPs as a medicinal plant-derived natural and efficient nanomaterial for clinical use.
Cotton is an important commercial crop whose growth and yield are severely affected by drought. S-adenosylmethionine (SAM) is widely involved in the plant stress response and growth regulation; ...however, the role of the S-adenosylmethionine synthase (
) gene family in this process is poorly understood. Here, we systematically analyzed the expression of
genes in Upland Cotton (
L.). A total of 16
genes were identified, each with a similar predicted structure. A large number of cis-acting elements involved in the response to abiotic stress were predicted based on promoter analysis, indicating a likely important role in abiotic stress responses. The results of qRT-PCR validation showed that
genes had different expression patterns after drought stress and in response to drought stress. Analysis of a selected subset of
genes showed increased expression in cultivar Xinluzhong 39 (drought resistant) when compared to cultivar Xinluzao 26 (drought-sensitive) upland cotton. This study provides important relevant information for further study of
genes in drought resistance research of upland cotton, which is helpful for drought-resistance improvement of upland cotton.
Canine inflammatory mammary carcinoma (CIMC) has a high incidence of metastasis, high lethality, and poor prognosis, which needs novel adjuvant agents. Tetramethylpyrazine-Rhein Derivative (TRD) has ...been shown to have antitumor activity, which is a potential research direction for CIMC.
This study evaluated the efficacy of TRD on CIMC in vitro and in vivo, and provided possibilities for the application of active compounds in traditional Chinese medicine.
In vitro, TRD cytotoxicity was measured with CCK-8. Flow cytometry and transmission electron microscope were used to detect the cell cycle, cell death, and changes in mitochondria. Wound-healing assay, cell invasion assay, and scanning electron microscope were used to evaluate the suppression of cell migration and invasion. Expression changes were detected by RT-qPCR and western blot assay. In vivo, the lung metastasis models were randomly divided into control, low-dose TRD, high-dose TRD, and positive groups. Each group was administered orally once a day for 18 days and took in vivo imaging photos.
The IC50 of TRD in CHMp and MDCK were 42.59 and 79.37 μM, respectively. TRD mediated cell apoptosis by mitochondrial damage and caused S and G2/M phase arrest by downregulating cyclin B1. Moreover, TRD reduced filopodia and inhibited cell migration by downregulating cadherins. In CIMC lung metastasis models, TRD could effectively inhibit tumor growth (P < 0.001) in the lungs without significant toxicity.
TRD showed potential activity to inhibit CIMC lung metastasis with multi-target and low toxicity.
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•Canine inflammatory mammary carcinoma features metastasis and a poor prognosis.•Tetramethylpyrazine and rhein have antitumor activity.•Tetramethylpyrazine-Rhein Derivative (TRD) caused apoptosis and cell cycle arrest.•TRD reduced cell migration, filopodia, and cadherins with TGF-β1/smad and MAPK.•TRD inhibited lung metastasis with multi-target and low toxicity.
Through the self-assembled strategy to improve the clinical efficacy of the existing drugs is the focus of current research. Herbal formula granule is a kind of modern dosage form of traditional ...Chinese medicine (TCM) which has sprung up in recent decades. However, whether it is equivalent to the TCM decoction that has been used for thousands of years has always been a controversial issue. In this paper, taking the herb pair of Coptidis Rhizoma-Scutellariae Radix and its main component berberine-baicalin as examples, the differences and mechanisms of self-assemblies originated from the co-decoction and physical mixture were studied, respectively. Moreover, the relationship between the morphology and antibacterial effects of self-assemblies was illuminated via multi-technology. Our study revealed that the physical mixture's morphology of both the herb pair and the phytochemicals was nanofibers (NFs), while their co-decoction's morphology was nanospheres (NPs). We also found that the antibacterial activity was enhanced with the change of self-assemblies' morphology after the driving by thermal energy. This might be attributed to that NPs could influence amino acid biosynthesis and metabolism in bacteria. Current study provides a basis that co-decoction maybe beneficial to enhance activity and reasonable use of herbal formula granule in clinic.
Due to the challenges in data acquisition, especially for developing countries and at local levels, spatiotemporal evaluation for SDG11 indicators was still lacking. The availability of big data and ...earth observation technology can play an important role to facilitate the monitoring of urban sustainable development. Taking Guilin, a sustainable development agenda innovation demonstration area in China as a case study, we developed an assessment framework for SDG indicators 11.2.1, 11.3.1, and 11.7.1 at the neighborhood level using high-resolution (HR) satellite images, gridded population data, and other geospatial big data (e.g., road network and point of interest data). The findings showed that the proportion of the population with convenient access to public transport in the functional urban area gradually improved from 42% in 2013 to 52% in 2020. The increase in built-up land was much faster than the increase in population. The areal proportion of public open space decreased from 56% in 2013 to 24% in 2020, and the proportion of the population within the 400 m service areas of open public space decreased from 73% to 59%. The township-level results indicated that low-density land sprawling should be strictly managed, and open space and transportation facilities should be improved in the three fast-growing towns, Lingui, Lingchuan, and Dingjiang. The evaluation results of this study confirmed the applicability of SDG11 indicators to neighborhood-level assessment and local urban governance and planning practices. The evaluation framework of the SDG11 indicators based on HR satellite images and geospatial big data showed great promise to apply to other cities for targeted planning and assessment.
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