A new triterpene, javablumine A (1) along with six known ones were isolated from the aerial parts of Sambucus javanica Blume. They were identified as ...3β,23-dihydroxy-11α,12α-epoxy-urs-20(30)-en-28,13β-olide (1), ursolic acid (2), pomolic acid (3), oleanic acid (4), 2α-hydroxy-oleanolic acid (5), α-amyrin (6), and lupeol palmitate (7), respectively. Compounds 1 and 3 exhibited inhibitory effect against nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW264.7 macrophage cell lines with IC
50
values of 17.4 and 26.2 μM, respectively.
Efficient and selective dehydrogenation of formic acid is a key challenge for a fuel‐cell‐based hydrogen economy. Though the development of heterogeneous catalysts has received much progress, their ...catalytic activity remains insufficient. Moreover, the design principle of such catalysts are still unclear. Here, experimental and theoretical studies on a series of mono‐/bi‐metallic nanoparticles supported on a NH2‐N‐rGO substrate are combined for formic acid dehydrogenation where the surface energy of a metal is taken as a relevant indicator for the adsorption ability of the catalyst for guiding catalyst design. The AuPd/NH2‐N‐rGO catalyst shows record catalytic activity by reducing the energy barrier of rate controlling steps of formate adsorption and hydrogen desorption. The obtained excellent results both in experiments and simulations could be extended to other important systems, providing a general guideline to design more efficient catalysts.
A AuPd/NH2‐N‐rGO catalyst shows supreme catalytic performance for the decomposition of formic acid at room temperature, with a turnover frequency (TOF) of 4445.6 h−1. Developments in the experiments and simulations of high‐performance catalysts may promote the practical application of formic acid as a promising hydrogen storage material.
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•H2O has an inhibition effect on soot formation.•Soot morphology evolutions in the flames with H2O addition are revealed.•H2O slows down soot inception process but promotes soot ...surface growth.•H2O addition leads to a higher degree of carbonization in soot nanostructure.•H2O addition slightly reduces soot oxidation reactivity.
The effects of H2O addition on the evolutions of soot morphology, nanostructure, and oxidation reactivity were investigated in ethylene inverse diffusion flames. The thermophoretic sampling and transmission electron microscopy (TEM) analysis were used to evaluate the soot morphological characteristics including primary particle diameter, projected area of agglomerates, and fractal dimension. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) were utilized to gain the nanostructure and crystallite features and thermogravimetric analyzer (TGA) was adopted for oxidation reactivity by analyzing the soot collected via quartz plate sampling. A reduction in soot production was found with increasing H2O concentration, which illustrated an inhibition effect of H2O on soot formation. The soot morphology evolutions further demonstrated that H2O addition could decrease soot inception process from the reduced sizes of primary particles and agglomerates, and fractal dimension. The HRTEM and XRD results showed that the increasing H2O addition led to larger fringe length, lower fringe tortuosity, and smaller interlayer spacing of soot, which indicated a higher carbonization degree in soot nanostructure. The soot oxidation reactivity was slightly reduced with H2O addition.
Ferns are primitive vascular plants with diverse morphologies and structures. Plant anatomical traits and their linkages can reflect adaptation to the environment; however, these remain are still ...poorly understood in ferns. The main objective of this study was to explore whether there was structural coordination among and within organs in fern species. We measured 16 hydraulically related anatomical traits of pinnae, petioles, and roots of 24 representative fern species from the tropical and subtropical forest understory and analyzed trait correlation networks. In addition, we examined phylogenetic signals for the anatomical traits and analyzed co‐evolutionary relationships. These results indicated that stomatal density and all petiole anatomical traits exhibited significant phylogenetic signals. Evolutionary correlations were observed between the tracheid diameter and wall thickness of the petiole and between the water transport capacity of the petiole and stomatal density. Conversely, anatomical traits of roots (e.g., root diameter) showed no phylogenetic signals and were not significantly correlated with those of the pinnae and petioles, indicating a lack of structural coordination between the below‐ and above‐ground organs. Unlike angiosperms, vein density is unrelated to stomatal density or pinna thickness in ferns. As root diameter decreased, the cortex‐to‐stele diameter ratio decreased significantly (enhanced water absorption) in angiosperms but remained unchanged in ferns. These differences lead to different responses of ferns to climate change and improve our knowledge of the water adaptation strategies of ferns.
Flexible supercapacitors (SCs) with compact configuration are ideal energy storage devices for portable electronics, owing to their original advantages (e.g., fast charging/discharging). To ...effectively reduce the volume of SCs, an integrated electrode of free-standing polyaniline (PANI)/single-wall carbon nanotube (SWCNT) film with high performance has been developed via a facile solution deposition method, which can be employed as current collector and active material in the meantime. Thanks to the strong π–π interactions between PANI and CNTs, an efficient conductive network with ordered PANI molecular chains is formed in this hybrid film electrode, which is beneficial for the ion diffusion process and fast redox reaction resulting in a high capacitance of 446 F g–1 and outstanding cycling stability, achieving 98% retention over 13 000 cycles. Predictably, solid-state SCs constructed by this free-standing PANI/SWCNT film electrode exhibited remarkable mechanical stability and flexibility in a compact configuration, let alone its excellent capacitive performance (218 F g–1). Moreover, the highest energy density of flexible solid-state SC reached 19.45 Wh kg–1 at a power density of 320.5 W kg–1, further indicating a good potential as an energy storage device. This work would inspire other simple process techniques for high-performance flexible SCs, catering to the demand of portable electronic devices.
Microfluidic spinning technology (MST), incorporating microfluidics with chemical reactions, has gained considerable interest for constructing anisotropic advanced microfibers, especially helical ...microfibers. However, these efforts suffer from the limited material choices, restricting their applications. Here, a new phase inversion‐based microfluidic spinning (PIMS) method is proposed for producing helical microfibers. This method undergoes a physicochemical phase inversion process, which is capable of efficiently manufacturing strong (tensile stress of more than 25 MPa), stretchable, flexible and biocompatible helical microfibers. The helical microfibers can be used to fabricate bi‐oriented stretchable artificial abdominal skin, preventing incisional hernia formation and promoting the wound healing without conglutination. This research not only offers a universal approach to design helical microfibers but also provides a new insight into artificial skin.
A novel phase inversion‐based microfluidic spinning (PIMS) technology is developed to continuously produce stretchable high‐strength polycaprolactone (PCL) helical microfibers with controllable structures. The helical microfibers are weaved into strong, bi‐oriented stretchable, flexible and biocompatible artificial skins meshes, which can be used to prevent abdominal incisional hernia formation and promote wound healing.
Gastrointestinal microbiota may be involved in
associated gastric cancer development. The aim of this study was to explore the possible microbial mechanisms in gastric carcinogenesis and potential ...dysbiosis arising from
infection.
Deep sequencing of the microbial 16S ribosomal RNA gene was used to investigate alterations in paired gastric biopsies and stool samples in 58 subjects with successful and 57 subjects with failed anti-
treatment, relative to 49
negative subjects.
In
positive subjects, richness and Shannon indexes increased significantly (both p<0.001) after successful eradication and showed no difference to those of negative subjects (p=0.493 for richness and p=0.420 for Shannon index). Differential taxa analysis identified 18 significantly altered gastric genera after eradication. The combination of these genera into a Microbial Dysbiosis Index revealed that the dysbiotic microbiota in
positive mucosa was associated with advanced gastric lesions (chronic atrophic gastritis and intestinal metaplasia/dysplasia) and could be reversed by eradication. Strong coexcluding interactions between
and
,
,
,
,
were found only in advanced gastric lesion patients, and were absent in normal/superficial gastritis group. Changes in faecal microbiota included increased
after successful
eradication and more upregulated drug-resistant functional orthologs after failed treatment.
infection contributes significantly to gastric microbial dysbiosis that may be involved in carcinogenesis. Successful
eradication potentially restores gastric microbiota to a similar status as found in uninfected individuals, and shows beneficial effects on gut microbiota.
It is well established that ferroptosis is primarily induced by peroxidation of long-chain poly-unsaturated fatty acid (PUFA) through nonenzymatic oxidation by free radicals or enzymatic stimulation ...of lipoxygenase. Although there is emerging evidence that long-chain saturated fatty acid (SFA) might be implicated in ferroptosis, it remains unclear whether and how SFA participates in the process of ferroptosis. Using endogenous metabolites and genome-wide CRISPR screening, we have identified FAR1 as a critical factor for SFA-mediated ferroptosis. FAR1 catalyzes the reduction of C16 or C18 saturated fatty acid to fatty alcohol, which is required for the synthesis of alkyl-ether lipids and plasmalogens. Inactivation of FAR1 diminishes SFA-dependent ferroptosis. Furthermore, FAR1-mediated ferroptosis is dependent on peroxisome-driven ether phospholipid biosynthesis. Strikingly, TMEM189, a newly identified gene which introduces vinyl-ether double bond into alkyl-ether lipids to generate plasmalogens abrogates FAR1-alkyl-ether lipids axis induced ferroptosis. Our study reveals a new FAR1-ether lipids-TMEM189 axis dependent ferroptosis pathway and suggests TMEM189 as a promising druggable target for anticancer therapy.
It is well known that magnetic field is one of the effective tools to improve the activity of hydrogen evolution reaction (HER), but considering the inconvenient application of an external magnetic ...field, it is essential to find a ferromagnetic material with high HER activity itself. Fortunately, recent study has shown that the two‐dimmention (2D) Fe2Sn monolayer is a stable ferromagnetic topological Weyl semimetal material with high Tc of 433 K. Here, we report the Fe2Sn monolayer can be used as an alternative HER catalyst compared with expensive platinum (Pt). Our first‐principles results show that the Gibbs free energy (ΔGH*) value of the spin polarized Fe2Sn monolayer is −0.06 eV, much better than that without considering spin polarization (−1.23 eV). Moreover, the kinetic analysis demonstrates that the HER occurs on the Fe2Sn monolayer according to the Volmer‐Tafel mechanism with low energy barriers. Hence, our findings provide obvious evidence for spin‐polarization‐improved HER activity, paving a new way to design high‐performance HER catalysts.
Spin polarization: We investigate the hydrogen evolution reaction activity (HER) activity of basal plane of the 2D ferromagnetic Weyl semimetal Fe2Sn. Our findings show that the Fe2Sn monolayer in spin polarized state exhibit superior HER performance when compared with that in spin un‐polarized, indicating that spin polarization enables high HER activity.
•The methods for analyzing phosphate starvation-induced secreted APase activity were provided.•A brief historical review on the identification of phosphate starvation-induced APase was provided.•The ...functions of phosphate starvation-induced APase were reviewed.•The molecular mechanisms that regulate phosphate starvation-induced APase were reviewed.•A perspective on future direction in this field was discussed.
Phosphorus is essential for plant growth and development, but levels of inorganic phosphate (Pi), the major form of phosphorus that plants assimilate, are quite limiting in most soils. To cope with Pi deficiency, plants trigger a suite of adaptive responses, including the induction and secretion of acid phosphatases (APases). In this article, we describe how Pi starvation-induced (PSI) APases are analyzed, and we provide a brief historical review of their identification. We then discuss the current understanding of the functions of PSI-secreted APases and how these APases are regulated at the molecular level. Finally, we provide a perspective on the future direction of research in this field.
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