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In the field of high-power microwave (HPM) devices with low magnetic fields, the efficiency, impedance, and stability of the diode are significantly reduced by the backward current. This article investigates the process that backward current bombards the anode, leading to anode ions bombarding the cathode rod, and ultimately enhancing the cathode rod emission. The study also examines the reasons behind the sharp change in diode impedance and the effect of the anode material on the diode. Finally, methods for suppressing the backward current are presented, including the anode material and cathode rod structure. The experiments demonstrate that these methods can suppress the backward current, enhance diode impedance, and improve diode impedance stability and structure lifetime.

Crack-based flexible strain sensors with ultra-high sensitivity under tiny strain are highly desired for environmental perception and motion detection of novel flexible and miniature robots. However, previously reported methods for fabricating crack patterns have often sacrificed the cyclic stability of the sensor, leading to a trade-off relationship between the sensitivity and the cyclic stability. Here, a universal and simple strategy based on fatigue loading with an ultra-large cumulative strain of up to ∼1.2 × 107%, rather than the traditionally quasi-static pre-overloading methods, is proposed to introduce channel cracks in the sensing layer without sacrificing the cyclic stability. The developed flexible strain sensors exhibit high strain-sensitivity (gauge factor = 5798) under tiny strain (< 3%), high cyclic stability (15 000 cycles) and a low strain detecting limit (0.02%). Furthermore, a leaf-like mechanosensor is developed using the fatigue crack-based strain sensor for the realization of multifunctional applications in environment perception and micro-motion detection. Brilliant airflow sensing performance with a wide sensing range (0.93–11.93 m s−1) and a fast response time (0.28 s) for amphibious applications is demonstrated. This work provides a new strategy for overcoming limits of crack-based flexible strain sensors and the developed leaf-like mechanosensor shows great application potential in miniature and flexible reconnaissance robots.

Photoinduced charge separation and transfer are the core factors affecting the photoelectrochemical performance of BiVO4-based photoanodes. Herein, a hole extraction layer was inserted between a BiVO4photoanode and an oxygen evolution cocatalyst (OEC). The introduction of Cu2O as a hole extraction layer between the OEC layer (FeOOH/NiOOH) and BiVO4optimized the migration paths and extended the lifetimes of the photogenerated holes, thus enhancing the photoelectrochemical performance of the photoelectrode. The charge separation efficiency of the optimized BiVO4/Cu2O/FeOOH/NiOOH photoanode was 92.0% significantly higher than the 70.6% efficiency for pure BiVO4. As expected, this photoanode also displayed a high photocurrent density of 3.85 mA cm−2at 1.23 VRHE(under AM 1.5G illumination), which was 2.77 times greater than that of pure BiVO4. Our results indicate that electrodepositing a Cu2O hole extraction layer is a simple and scalable method for increasing the photoelectrochemical activity of BiVO4photoanodes for solar water splitting.

Patients harboring CRLF2-rearranged B-lineage acute lymphocytic leukemia (B-ALL) face a 5-year survival rate as low as 20%. While significant gains have been made to position targeted therapies for B-ALL treatment, continued efforts are needed to develop therapeutic options with improved duration of response. Here, first we have demonstrated that patients with CRLF2-rearranged Ph-like ALL harbor elevated thymic stromal lymphopoietin receptor (TSLPR) expression, which is comparable with CD19. Then we present and evaluate the anti-tumor characteristics of 1B7/CD3, a novel CD3-redirecting bispecific antibody (BsAb) that co-targets TSLPR. In vitro, 1B7/CD3 exhibits optimal binding to both human and cynomolgus CD3 and TSLPR. Further, 1B7/CD3 was shown to induce potent T cell activation and tumor lytic activity in both cell lines and primary B-ALL patient samples. Using humanized cell- or patient-derived xenograft models, 1B7/CD3 treatment was shown to trigger dose-dependent tumor remission or growth inhibition across donors as well as induce T cell activation and expansion. Pharmacokinetic studies in murine models revealed 1B7/CD3 to exhibit a prolonged half-life. Finally, toxicology studies using cynomolgus monkeys found that the maximum tolerated dose of 1B7/CD3 was ≤1 mg/kg. Overall, our preclinical data provide the framework for the clinical evaluation of 1B7/CD3 in patients with CRLF2-rearranged B-ALL.

Objective: There is a lack of effective and long-term safe drugs for the treatment of osteoarthritis (OA). Tetrandrine (Tet) has been approved and used to treat rheumatoid arthritis for several decades, but its effect on OA has not been investigated. Herein, we explored the effect of Tet on OA and its underlying mechanism. Methods: OA was induced using destabilization of the medial meniscus (DMM) in C57BL/6J mice. The animals were randomly divided into sham, DMM, Tet, celecoxib (CXB), and indomethacin (INDO) groups. Each group was given solvent or corresponding drugs by gavage for 7 weeks after convalescence. Pathological staining, OARSI scores, micro-computed tomography and behavior tests were performed to evaluate the effects of Tet. Results: Tet remarkably alleviated cartilage injury in the knee joint, limited bone remodeling in the subchondral bone, and delayed progression of OA. Tet also significantly relieved joint pain and maintained function. Further mechanistic studies revealed that Tet lowered inflammatory cytokine levels and selectively suppressed gene and protein expression of cyclooxygenase (COX)-2 but not COX-1 (P&lt;0.01). Tet also reduced the production of prostaglandin E2 without damaging the gastric mucosa. Conclusion: We found that Tet could selectively inhibit COX-2 gene expression and decrease cytokine levels in mice, thus reducing inflammation and improving OA without obvious gastric adverse events. These results provide a scientific basis for the clinical application of Tet in the treatment of OA.

Developing robust and effectual nonprecious electrocatalysts for the bifunctional hydrogen oxidation and evolution reactions (HOR and HER) in alkaline electrolyte is of critical significance for the realization of future hydrogen economy but challenging. Herein, this work demonstrates a new routine for the preparation of bio-inspired FeMo2S4microspheres viathe one-step sulfuration of Keplerate-type polyoxometalate {Mo72Fe30}. The bio-inspired FeMo2S4microspheres feature potential-abundant structural defects and atomically precise iron doping and act as an effective bifunctional electrocatalyst for hydrogen oxidation/reduction reactions. The FeMo2S4catalyst presents an impressive alkaline HOR activity compared to FeS2and MoS2with the high mass activity of 1.85 mA·mg–1and high specific activity as well as excellent tolerance to carbon monoxide poisoning. Meanwhile, FeMo2S4electrocatalyst also displayed prominent alkaline HER activity with a low overpotential of 78 mV at a current density of 10 mA·cm–2and robust long-term durableness. Density functional theory (DFT) calculations indicate that the bio-inspired FeMo2S4with a unique electron structure possesses the optimal hydrogen adsorption energy and enhanced adsorption of hydroxyl intermediates, which accelerates the potential-determining Volmer step, thus promoting the HOR and HER performance. This work provides a new pathway for designing efficient noble-metal-free electrocatalysts for the hydrogen economy.

Overcoming ice accretion on external aircraft wing surfaces plays a crucial role in aviation, and developing environmentally friendly passive anti-icing surfaces is considered to be a promising strategy. Superhydrophobic surfaces (SHSs) have attracted increasing attention due to their potential advantages of keeping the airframe dry without causing additional aerodynamic losses. However, the passive anti-icing performances of SHSs reported to date varied a lot under different icing test conditions. Therefore, a systematic investigation is necessary to elucidate the icing conditions where SHSs can remain effective and pave the way for SHSs toward practical anti-icing applications. Herein, we designed and fabricated a typical type of SHS featuring dual-scale hierarchical structures with arrayed micromountains (with both spacings and heights of tens of micrometers) covered by single-scale sandy-corrugation-like periodic structures (with both spacings and heights of only several micrometers) (termed SS1). Its anti-icing performances under three representative icing conditions, including static water freezing, dynamic supercooled-droplet impinging, and icing wind tunnel conditions, were comparatively investigated. The SS1 SHS maintained a lower static ice-adhesion strength (<60 kPa even after 50 deicing cycles at temperatures as low as −25 °C), which was attributed to a cumulative cracking effect facilitating the ice detachment. Within the laboratory dynamic icing tests, the SS1 SHSs with micromountain heights of 20–30 μm performed optimally in the antiadhesion of supercooled droplets (at an impinging velocity of 3.4 m/s and temperatures of −5 to −25 °C). In spite of the significant anti-icing performances of the SS1 SHSs in both static and dynamic laboratory tests, they could hardly sustain reliable passive anti-icing performances in harsher icing wind tunnel tests with supercooled droplets impinging their surfaces at velocities of up to 50 m/s at a temperature of −5 °C for 10 min. This study can inspire the development of improved SHSs for achieving satisfactory anti-icing performances in real-aviation conditions.

Capillary-fed thin-film evaporation viamicro/nanoscale structures has attracted increasing attention for its high evaporation flux and pumpless liquid replenishment. However, maximizing thin-film evaporation has been hindered by the intrinsic trade-off between the heat flux and liquid transport. Here, we designed and fabricated nanostructured micro-steam volcanoes on copper surfaces featuring triple-level super-wicking routes to overcome this trade-off and boost water evaporation. The triple-level super-wicking routes enable the continuous formation of a 3D thin film for highly efficient evaporation by continuous self-driven liquid replenishment and extending the thin-film region. The micro-steam volcanoes increased the surface area by 225%, improving the evaporation rate by 141%, with a rapid self-pumping water transport speed up to 80 mm s−1. A remarkable solar-driven water evaporation rate of 3.33 kg m−2h−1under one sun vertical incidence was achieved, which is among the highest reported values for metal-based evaporators. When attached to electric-heating plates, the evaporator realized an electrothermal evaporation rate of 12.13 kg m−2h−1. Moreover, it can also be used for evaporative cooling with enhanced convective heat transfer, reaching a 36.2 °C temperature reduction on a heat source with a heat flux of 6 W cm−2. This study promises a general strategy for designing thin-film evaporators with high efficiencies, low costs, and multi-functional compatibilities.

Based on geometrical characteristics, all surface microstructures are categorized into two types: closed-cell and open-cell structures. Closed-cell structures are well-known to have more stable and durable superhydrophobicity at room temperatures. However, in low-temperature environments where massive environmentally induced physical changes emerge, whether closed-cell surfaces can maintain good anti-icing performances has not yet been confirmed, and thus how to design optimal superhydrophobic anti-icing microstructures is rarely reported. Here, we apply an ultrafast laser to fabricate superhydrophobic surfaces with tunable patterned micro-nanostructures from a complete closed-cell to different ratios and to a complete open-cell. We discover that droplets on closed-cell structures completely degrade to the high-adhesion Wenzel state after icing and melting cycles while those on the open-cell structures well recover to the original Cassie-Baxter state. We propose an improved ideal gas model to clarify the mechanisms that the decreased air pocket pressure and the air dissolution on closed-cell structures induce easy impalement during icing and the difficult recovery during melting, paving the way for optimizing the anti-icing structure design. The optimized open-cell surfaces exhibit over 33 times lower ice adhesion strengths (1.4 kPa) and long-term icephobic durability (<20 kPa after 33 deicing cycles) owing to the increased air pocket pressure at low temperatures. Significant dewetting processes during condensation endow the open-cell structures with more remarkable high-humidity resistance and anti-frosting properties. Our study reveals the general design principle of superhydrophobic anti-icing structures, which might guide the design of superhydrophobic anti-icing surfaces in practical harsh environments.

Understanding the structure of the plastic deformation region is important for improving the mechanical property of amorphous alloys. What kind of structure is conducive to the formation of deformation zone is however still unclear yet. The uniaxial compression of amorphous Cu64.5Zr35.5has been conducted by a large-scale molecular dynamics simulation. The structure characteristics of the system, especially the deformation regions are systematically investigated based on the newly developed topologically close-packed cluster (TCP) method and the shear transformation zone theory. Results indicate that the deformation process is divided into three stages that can be reasonably explicated by the population and heredity of the 30 top largest standard clusters (LaSCs). It is also found that the response of topologically close-packed (TCP) atoms to strain is closely related with the bond number connected to icosahedra atoms, and the densely packed TCP atoms are more prone to non-affine displacement than the loosely packed ones, which act as the carrier of accommodating plastic deformation. In addition, the plastic deformation units are composed of various types of LaSCs, and the region with local translational symmetry is observed. These findings greatly improve the understanding of the relationship of microstructure and deformation of metallic glasses.

Selective oxidation of aryl alkenes to aldehydes is an important approach to produce industrial raw materials, in which the exploration of an efficient heterogeneous catalyst is significant but challenging. In this work, three hydrogen bond-mediated polyoxometalate(POM)-contained metal–organic networks with the formulas of [Ni(BTD)2(H2O)2]2[SiW12O40]·12H2O (1), [Ni(BTD)2(H2O)]2[SiW12O40]·6H2O (2) and [Zn(BTD)2(H2O)]2[SiW12O40]·6H2O (3) (BTD = 4H,4ʹH-[3,3ʹ-bi(1,2,4-triazole)]-5,5ʹ-diamine) were hydrothermally synthesized, in which the metal–organic fragments interact with POM clusters via abundant hydrogen bonding to extend the structure into three-dimensional supramolecular networks. To be explored as heterogenous catalysts, compounds 1–3showed high catalytic activity and selectivity for the selective oxidation of styrene to benzaldehyde. Among them, compound 1exhibits the highest performance with ca. 99% styrene conversion and ca. 99% selectivity of benzaldehyde in 5 h. Moreover, compound 1displays rich substrate compatibility, recyclability and good structural stability. A series of experiments demonstrated that the high performance of compound 1should be attributed to the synergistic effect among polyoxoanion and coordination-unsaturated metal centers in metal–organic fragments, which facilitates the activation of H2O2and styrene substrates, thus enhancing the catalytic performance.

The wicking phenomenon, including wicking and hemiwicking, has attracted increasing attention for its critical importance to a wide range of engineering applications, such as thermal management, water harvesting, fuel cells, microfluidics, and biosciences. There exists a more urgent demand for anisotropic wicking behaviors since an increasing number of advanced applications are significantly complex. For example, special-shaped vapor chambers and heating atomizers in some electronic cigarettes need liquid replenishing with various velocities in different directions. Here, we report two-dimensional anisotropic hemiwicking behaviors with elliptical shapes on laser structured prismatic microgrooves. The prismatic microgrooves were fabricated via one-step femtosecond laser direct writing, and the anisotropic hemiwicking behaviors were observed when utilizing glycerol, glycol, and water as the test liquid. Specifically, the ratios of horizontal wicking distance in directions along short and long axes were tan 0°, tan 15°, tan 30°, and tan 45° for samples with cross-angles of 0°, 30°, 60°, and 90°, respectively. The vertical water wicking front displayed corresponding angles under the guidance of laser structured prismatic microgrooves. Theoretical analysis shows that the wicking distance is mainly dependent on the cross-angle θ and surface roughness, in which the wicking distance is proportional to cos(θ/2). Driven by the capillary pressure forming in the narrow microgrooves, the liquid initially filled the valleys of microgrooves and then surrounded and covered the prismatic ridges with laser-induced nanoparticles. The abundant nanoparticles increased the surface roughness, leading to the enhancement of wicking performance, which was further evidenced by the larger wicking speed of the sample with more nanoparticles. The mechanism of anisotropic hemiwicking behaviors revealed in this work paves the way for wicking control, and the proposed prismatic microgrooved surfaces with two-dimensional anisotropic hemiwicking performance and superhydrophilicity could serve in a broad range of applications, especially for the advanced thermal management with specific heat load configurations.

ABSTRACTMacroautophagy/autophagy is an important innate and adaptive immune response that can clear microbial pathogens through guiding their degradation. Virus infection in animals and plants is also known to induce autophagy. However, how virus infection induces autophagy is largely unknown. Here, we provide evidence that the early phase of rice black-streaked dwarf virus (RBSDV) infection in Laodelphax striatelluscan also induce autophagy, leading to suppression of RBSDV invasion and accumulation. We have determined that the main capsid protein of RBSDV (P10) is the inducer of autophagy. RBSDV P10 can specifically interact with GAPDH (glyceraldehyde-3-phosphate dehydrogenase), both in vitroand in vivo. Silencing of GAPDHin L. striatelluscould significantly reduce the activity of autophagy induced by RBSDV infection. Furthermore, our results also showed that both RBSDV infection and RBSDV P10 alone can promote phosphorylation of AMP-activated protein kinase (AMPK), resulting in GAPDH phosphorylation and relocation of GAPDH from the cytoplasm into the nucleus in midgut cells of L. striatellusor Sf9 insect cells. Once inside the nucleus, phosphorylated GAPDH can activate autophagy to suppress virus infection. Together, these data illuminate the mechanism by which RBSDV induces autophagy in L. striatellus, and indicate that the autophagy pathway in an insect vector participates in the anti-RBSDV innate immune response.Abbreviations3-MA: 3-methyladenine; AMPK: AMP-activated protein kinase; ATG: autophagy-related; co-IP: co-immunoprecipitation; DAPI: 4ʹ,6-diamidino-2-phenylindole; dpf: days post-feeding; dsRNA: double-stranded RNA; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GST: glutathione-S-transferase; RBSDV: Rice black-streaked dwarf virus; TEM: transmission electron microscope.

The influence of trace Y on the microstructure evolution and mechanical properties of Mg100−xYx(x=0.25, 0.75, 1.5, 3, 4, 5, at.%) alloys during solidification process was investigated via molecular dynamics (MD) simulations. The results show that the Mg100−xYxalloys are mainly characterized by a face-centered cubic (FCC) crystal structure; this is different from pure metal Mg, which exhibits a hexagonal close packed (HCP) structure at room temperature. Among these alloys, Mg99.25Y0.75has a larger proportion of FCC cluster structures, with the highest fraction reaching 56.65%. As the content of the Y increases up to 5 at.% (Mg95Y5alloy), the amount of amorphous structures increases. The mechanical properties of the Mg100−xYxalloys are closely related to their microstructures. The Mg99.25Y0.75and Mg97Y3alloys exhibit the highest yield strengths of 1.86 and 1.90 GPa, respectively. The deformation mechanism of the Mg−Y alloys is described at the atomic level, and it is found that a difference in the FCC proportion caused by different Y contents leads to distinct deformation mechanisms.

Abstract: Molecular dynamics simulation (MD) has been conducted to investigate the pressure effect on microstructure of copper during rapid solidification. The pressure increases the onset temperature (Tc) of nucleation but decreases the energy of atoms and the lattice constant of the final face-centered cubic crystal. Before temperature decreases to Tcthe average coordination number (ACN) of atoms and the percentage of topologically close-packed atoms (PTCP) increase, while the number of types of the largest standard clusters (KLaSC) decreases and that of the topologically close-packed (KTCP) atoms is about the same. Interestingly they are pressure-independent constants at Tc, with KLaSC= 3300, ACN = 13.08, PTCP= 18.3%, and KTCP= 33 in the super-cooled copper. Graphical abstract:

Our previous study demonstrated that paeoveitol D, a benzofuran compound isolated from Paeonia veitchii, displayed activity on MT1and MT2receptors with agonistic ratios of 57.5% and 51.6% at a concentration of 1 mM. To explore the structure–activity relationships, 34 paeoveitol D derivatives were synthesized and evaluated for their MT1and MT2agonistic activities using the Fluo-8 calcium assay. Among them, 16 and 18 derivatives increased agonistic activities on the MT1and MT2receptors, respectively. Compound 18indicated EC50values of 21.0 and 298.9 μM on MT1and MT2receptors in agonistic dose response curves with Tango assays and shortened immobility time in the forced swim test. The preliminary mechanism-of-action investigation manifested that the antidepressant activity of compound 18may be mediated by promoting serotonin (5-HT) and dopamine (DA) levels in the mice brain. Compound 18also showed favorable pharmacokinetic profiles and low toxicity in vivo. These results suggest that compound 18could be a potential antidepressant agent.

The biomimetic synthesis of guaianolide dimers lavandiolides H, I, and K and artematrolide F containing a spirolactone moiety has been accomplished for the first time from naturally abundant arglabin in four to six steps with an overall yield up to 60%, and a series of natural product-like guaianolide dimers, trimer, and tetramer were also successfully synthesized. Notably, the trimeric compound exhibited antihepatoma cytotoxicity more potent than that of sorafenib with IC50values of 6.2 μM (HepG2), 6.8 μM (Huh7), and 7.2 μM (SK-HEP-1).

A highly efficient method for the selective formal C–H/C–H cross-coupling of azoles and (hetero)arenes was established through arylsulfonium intermediates under transition-metal catalysis, which produced a variety of 2-(hetero)aryl azoles in good to excellent yields. Advantages of the reaction included mildness, a good functional group tolerance, a wide range of substrates, a high regio- and chemoselectivity, one-pot procedures, and the late-stage functionalization of complex molecules without the use of oxidants, offering a promising strategy for the transition-metal-catalyzed C–H arylation of azoles.

The new generation of Sc and Zr modified Al alloys has been attracted wide concerns in aerospace industry, owing to the excellent mechanical performances and superior thermal stability than other normal Al alloys. By microalloying with Sc and Zr, the Al3(Sc, Zr) particle forms as the grain refiner during the solidification, which is extremely beneficial for the laser powder bed fusion (LPBF) processed Al alloys. In this study, a new type Al-14.1Mg-0.47Si-0.31Sc-0.17 Zr alloy was additively manufactured by LPBF, and the microstructure, tensile properties and thermal stability were studied in detail. By using a single melt-67° scanning strategy, the LPBF-processed specimen with a relative density of 99.4 % and tensile strength of 487.7 MPa was obtained at 160 W-200 mm/s. And this AlMgSiScZr alloy can still exhibit an excellent tensile strength of 393.9 MPa at a moderate temperature of 473 K. After the aging treatment, the tensile properties further increased due to the precipitate hardening of Mg2Si and Al3(Sc, Zr), and the maximum value (580 MPa) was reached at an aging time of 10 h. The average crystal size was almost unchanged after aging treated at 325 ℃ and 24 h, indicating this AlMgSiScZr alloy has an improved thermal stability. The AlMgSiScZr alloy is recommended to substitute some particular titanium alloys in aerospace field afterwards. [ABSTRACT FROM AUTHOR]

To investigate the potential phases in myopic retinal vascular alterations for further elucidating the mechanisms underlying the progression of high myopia (HM).

A novel Al-14.1Mg-0.47Si-0.31Sc-0.17 Zr alloy was applied in the printing process of selective laser melting (SLM), and the corresponding microstructural feature, phase identification, tensile properties and corrosion behavior of the AlMgSiScZr alloy were studied in detail. As fabricated at 160 W and 200 mm/s, the Mg content of bulk sample decreased to 11.7 wt% due to the element vaporization at high energy density, and the density of this additively manufactured AlMgSiScZr alloy was 2.538 g/cm3, which is 4.2 %∼8.5 % lighter than that of other SLM-processed Al alloys. After heat-treated (HT) at 325 ℃ and 6 h, the microstructure was almost unchanged with an alternate distribution of fine equiaxed crystals and coarse columnar crystals. Nano-sized Al 3 (Sc, Zr) and Mg 2 Si phases precipitated dispersedly in the Al matrix, and the tensile strength increased from 487.6 MPa to 578.4 MPa for precipitation strengthening and fine grain strengthening. With a fine grain size of 2.53 μm, an excellent corrosion resistance was obtained for the as-printed (AP) AlMgSiScZr alloy. While the corrosion resistance of HT sample decreased slightly for the formation of non-dense oxide layer and pitting corrosion induced by diffuse precipitation distribution. This SLM-printed AlMgSiScZr alloy with high specific strength, good thermal stability and excellent corrosion resistance has broad prospects for the aerospace and automotive applications. [ABSTRACT FROM AUTHOR]

Two rare flavanol-monoterpenoid hybrids, tsaokols A (1) and B (2), were isolated from the dried fruits of Amomum tsao-kounder the guidance of LCMS and bioassay. They showed significant α-glucosidase inhibitory activity with IC50values of 18.8 and 38.6 μmol/L.

The authors examined the original data of their work and noticed misuse of images in fig. 1 and fig. 3 (as shown below on the upper panels, red box). The correct images are shown on the lower panels (red box). The authors sincerely apologize for the mistake and confirm the change does not affect the scientific conclusion of the published work.

Artatrovirenols A and B (1and 2), two novel cagelike sesquiterpenoids, possess a unique 5/5/6/5/5-pentacyclic and a 5/5/6/5-tetracyclic system with an unprecedented tetracyclo[5.3.1.1.4,1101,5]dodecane scaffold from Artemisia atrovirens. The structures of compounds 1and 2including their absolute stereochemistry were elucidated through extensive spectroscopic analyses, X-ray crystallography, and quantum chemical calculations. Plausible biosynthetic pathways for the new isolates were proposed from the naturally occurring arglabin (3) via the key intramolecular Diels–Alder cycloaddition. Compound 1showed cytotoxicity against three human hepatoma cell lines (HepG2, SMMC-7721, and Huh7) with half maximal inhibitory concentration values of 123.8, 44.0, and 142.6 μΜ, respectively.

The phase transition of tungsten (W) under high pressures was investigated with molecular dynamics simulation. The structure was characterized in terms of the pair distribution function and the largest standard cluster analysis (LSCA). It is found that under 40−100 GPa at a cooling rate of 0.1 K/ps a pure W melt first crystallizes into the body-centred cubic (BCC) crystal, and then transfers into the hexagonal close-packed (HCP) crystal through a series of BCC−HCP coexisting states. The dynamic factors may induce intermediate stages during the liquid−solid transition and the criss-cross grain boundaries cause lots of indistinguishable intermediate states, making the first-order BCC−HCP transition appear to be continuous. Furthermore, LSCA is shown to be a parameter-free method that can effectively analyze both ordered and disordered structures. Therefore, LSCA can detect more details about the evolution of the structure in such structure transition processes with rich intermediate structures.

The dried fruits of Amomum tsao-kowere first revealed to have hypoglycemic effects on db/db mice at a concentration of 200 mg/kg. In order to clarify the antidiabetic constituents, 19 new flavanol–fatty alcohol hybrids, tsaokoflavanols A–S (1–19), were isolated and determined by extensive spectroscopic data and ECD calculations. Most of the compounds showed α-glucosidase and PTP1B dual inhibition, among which 1, 2, 6, 11, and 18exhibited obvious activity against α-glucosidase with IC50values of 5.2–9.0 μM, 20–35 times stronger than that of acarbose (IC50, 180.0 μM); meanwhile, 6, 10–12, and 19were PTP1B/TCPTP-selective inhibitors with IC50values of 56.4–80.4 μM, 2–4 times stronger than that of suramin sodium (IC50, 200.5 μM). Enzyme kinetics study indicated that compounds 1, 2, 6, and 11were α-glucosidase and PTP1B mixed-type inhibitors with Kivalues of 13.0, 11.7, 2.9, and 5.3 μM and 142.3, 88.9, 39.2, and 40.8 μM, respectively. Docking simulations proved the importance of hemiacetal hydroxy, the orientation of 3,4-dihydroxyphenyl, and the length of alkyl in binding with α-glucosidase and PTP1B.

Random screening suggested that the EtOH extract of Artemisia myriantha(Asteraceae) and its EtOAc fraction had cytotoxicity against HepG2 cells with inhibitory ratios of 30.6% and 53.5% at 50.0 μg/mL. Bioassay-guided isolation of the most active fractions (Fr. C and Fr. D) afforded 19 new sesquiterpenolides, artemyrianolides A–S (1–19), involving 13 germacranolides (1–13), four guaianolides (14–17), and two eudesmanolides (18and 19), together with 16 known sesquiterpenoids (20–35). The new compounds were characterized by physical data analyses (HRESIMS, IR, 1D and 2D NMR, ECD), and the absolute configurations of compounds 1, 2, and 11were determined by X-ray crystallography. Structurally, compounds 2and 11–13maintain an uncommon cis-fused 10/5 bicyclic system and compound 12possesses an unusual (7S) configuration. Twenty of the compounds exhibited cytotoxicity against HepG2, Huh7, and SMMC-7721 cell lines. Compound 9showed cytotoxic activity on both HepG2 and Huh7 cells with IC50values of 8.6 and 8.8 μM, and compounds 8and 33showed cytotoxicity to the three human hepatoma cell lines with IC50values of 4.9 and 7.4 μM (HepG2), 4.3 and 7.8 μM (Huh7), and 3.1 and 9.8 μM (SMMC-7721), respectively.

Abstract: Four new sesquiterpenoids, artemyrianins A–D (1–4), and three new norlignans, artemyrianins E–G (5–7), together with five known compounds (8–12), were isolated from the aerial parts of Artemisia myriantha(Asteraceae). The new compounds were established by spectroscopic data analyses (HRMS, IR, 1D and 2D NMR), and their absolute configurations were confirmed by the single-crystal X-ray diffraction or ECD calculations. The isolates showed cytotoxicity against HepG2 cells with IC50values ranging from 33.3 to 145.2 μM. Graphic Abstract:

Abstract: Two new sesquiterpenoids, artemlavanins A (1) and B (3), together with fifteen known compounds (2and 4−17) were isolated from the EtOH extract of Artemisia lavandulaefolia. The structures of new compounds were elucidated by extensive spectroscopic analyses (HRESIMS, 1D and 2D NMR) and ECD calculations. Compound 1was a sesquiterpenoid lactone possessing a rearranged eudesmane skeleton; compounds 2–5, 6–8, 9and 10–12belonged to the eudesmane, guaiane, oppositane and farnesane sesquiterpenoids, respectively; compounds 13–17were the phenyl derivatives with a 4-hydroxyacetophenone moiety. Twelve compounds (1–3, 5–7, 10–12, 14, 15and 17) displayed cytotoxicity against hepatic stellate cell line LX2 (HSC-LX2) with IC50values ranging from 35.1 to 370.3 μM. Compounds 2, 7, 10–12and 17exhibited the stronger cytotoxicity than silybin (IC50, 169.6 μM) with IC50values of 82.1, 35.1, 95.0, 83.8, 81.6 and 90.1 μM. Compound 7as the most active one showed significant inhibition on the deposition of human collagen type I (Col I), human hyaluronic acid (HA) and human laminin (HL) with IC50values of 10.7, 24.5 and 13.3 μM. Graphic Abstract:

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