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C26H41NO8, orthorhombic, P212121 (no. 19), a = 8.24370(10) Å, b = 13.1867(2) Å, c = 22.8490(4) Å, V = 2483.85(6) Å3, Z = 4, Rgt (F) = 0.0357, wRref (F 2) = 0.0975, T = 169.99(10) K.

The abnormal proliferation of vascular smooth muscle cells (VSMCs) is crucial in the atherosclerosis. Although long noncoding RNAs (lncRNAs) are implicated in a variety of diseases, their roles in activation of VSMCs proliferation and vascular disorder diseases are not well understood. In addition, heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2/B1) was reported to participate in lncRNAs-mediated function. Herein, we propose to investigate the role of lncRNA AC105942.1 and hnRNPA2/B1 in pathological VSMCs proliferation and the possible mechanisms in vitro. We have identified that lncRNA AC105942.1 was downregulated and hnRNPA2/B1 was upregulated in atherosclerotic plaques compared with normal artery tissues. Enhanced lncRNA AC105942.1 could noticeably inhibit Ang II-induced VSMCs proliferation. Further investigation suggested that lncRNA AC105942.1 could downregulate the expression of hnRNPA2/B1 and then regulate the level of CDK4 and p27. Taken together, our study indicated that lncRNA AC105942.1 downregulated hnRNPA2B1 to protect against the atherosclerosis by suppressing VSMCs proliferation. LncRNA AC105942.1 and hnRNPA2/B1 could represent potential therapeutic and diagnostic targets to atherosclerosis-related diseases.

Zhang, Ji-hui, Chen, Jin-lin, Xu, Wei-bin, Xia, Yi-ping, Zhu, Hao-yue, Wang, Jing-hao, Li, Yao-lan, Wang, Guo-cai, Zhang, Yu-bo, Chen, Neng-hua (2023): Undescribed phloroglucinol derivatives with antiviral activities from Dryopteris atrata (Wall. Ex Kunze) Ching. Phytochemistry (113585) 208: 113585, DOI: 10.1016/j.phytochem.2023.113585, URL: http://dx.doi.org/10.1016/j.phytochem.2023.113585

Pegaharines A-G (1-6), six novel β-carboline alkaloids representing three types of skeleton, were isolated from the seeds of Peganum harmala. Compound 1 is a peculiar β-carboline alkaloid characterized by the unprecedented carbon skeleton of an azepine-indole system. Compounds 3-6 represent the first examples of heterodimers constructed from rare tetracyclic β-carboline and classic tricyclic β-carboline alkaloids. Compounds 1 and 2 were characterized by X-ray crystallography. Compound 4 exhibited strong antiviral activity against HSV-2, with an IC50 value of 2.12 ± 0.14 μM.

One new alkaloid, 6, 7-dimethoxyisoquinoline

One new alkaloid, 6, 7-dimethoxyisoquinoline-N-oxide (1), one new benzofuran derivative, 3,7-dimethyl-6-acetyl-8-benzofuranol (2) and one new lignan, salsolains A (3), along with seven known compounds (4–10), were isolated from the whole plant of Salsola collina Pall. Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HR-ESI-MS, 1 D and 2 D NMR), and their absolute configurations were determined by the X-ray crystallography and ECD calculation. The activities of compounds 1–10 against inflammatory cytokines IL-6 and TNF-α levels on LPS-induced RAW 264.7 macrophages were assessed, especially, compound 5 (50 μM) exhibited the most significant anti-inflammatory activity with the secretion levels of IL-6 and TNF-α at 3.87% and 4.03%, respectively.

A phytochemical investigation on the alkaloids from water-soluble part of Sophora alopecuroides led to obtain forty matrine-type alkaloids (1–40) including eighteen new ones (1–18), which covers almost all positions of the oxygen substitution in matrine-type structure. Notably, eight compounds (1–8) belong to rare bis-amide matrine-type alkaloid. The new structures were determined based on extensive spectroscopic data, electronic circular dichroism (ECD) calculations, and six instances, verified by X-ray crystallography. Most of isolates showed anti-neuroinflammatory activities based on the expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in BV2 microglia cells. Especially, compound 39 can suppress those two mediator secretions in a dose-dependent manner with IC50 values of 21.6 ± 0.5 and 16.7 ± 0.8 μM, respectively. Further mechanistic study revealed that 39 suppressed the phosphorylation of IκBα and p65 subunit to regulate the NF-κB signaling pathway.

Two new isoquinoline alkaloids, 6 R,6aS-N-nantenine Nβ-oxide (1), 6S,6aS-N-nantenine Nα-oxide (2), along with nine known alkaloids, nantenine (3), oxonantenine (4), protopine (5), nornantenine (6),...

Phosphoinositide-3 kinase signaling modulates many cellular processes, including cell survival, proliferation, differentiation, and apoptosis. Currently, it is known that the establishment of respiratory syncytial virus infection requires phosphoinositide-3 kinase signaling. However, the regulatory pattern of phosphoinositide-3 kinase signaling or its corresponding molecular mechanism during respiratory syncytial virus entry remains unclear. Here, the involvement of phosphoinositide-3 kinase signaling in respiratory syncytial virus entry was studied. PIK-24, a novel compound designed with phosphoinositide-3 kinase as a target, had potent anti-respiratory syncytial virus activity both in vitro and in vivo. PIK-24 significantly reduced viral entry into the host cell through blocking the late stage of the fusion process. In a mouse model, PIK-24 effectively reduced the viral load and alleviated inflammation in lung tissue. Subsequent studies on the antiviral mechanism of PIK-24 revealed that viral entry was accompanied by phosphoinositide-3 kinase signaling activation, downstream RhoA and cofilin upregulation, and actin cytoskeleton rearrangement. PIK-24 treatment significantly reversed all these effects. The disruption of actin cytoskeleton dynamics or the modulation of phosphoinositide-3 kinase activity by knockdown also affected viral entry efficacy. Altogether, it is reasonable to conclude that the antiviral activity of PIK-24 depends on the phosphoinositide-3 kinase signaling and that the use of phosphoinositide-3 kinase signaling to regulate actin cytoskeleton rearrangement plays a key role in respiratory syncytial virus entry.

Pegaharines A-G (

A new sesquiterpene pyridine alkaloid (

The Zeeman splitting effect is observed in a strong magnetic field generated by a laser-driven coil. The expanding plasma from the coil wire surface is concentrated at the coil center and interacts with the simultaneously generated magnetic field. The Cu I spectral lines at wavelengths of 510.5541, 515.3235, and 521.8202 nm are detected and analyzed. The splittings of spectral lines are used to estimate the magnetic field strength at the coil center as ∼31.4 ± 15.7 T at a laser intensity of ∼5.6 × 1015 W/cm2, which agrees well with measurements using a B-dot probe. Some other plasma parameters of the central plasma disk are also studied. The temperature is evaluated from the Cu I spectral line intensity ratio, while the electron density is estimated from the Stark broadening effect.

Five novel quinolizidine-based alkaloids (1-5) were obtained from the seeds of Sophora alopecuroides L. Compounds 1 and 2 are the first examples of sparteine-indolizine and matrine-indolizine alkaloids, respectively, whereas 3 and 4 are epimeric normatrine-julolidine alkaloids with unusual skeletons. The structures of these compounds were determined by spectroscopic methods, single-crystal X-ray diffraction, and electronic circular dichroism analyses. Hypothetical biosynthetic pathways of 1-5 were proposed. Compound 2 exhibited significant antiviral activity against the hepatitis B virus.

Seven undescribed phloroglucinol derivatives, tomentodiones N−T, and eleven known ones were isolated from Rhodomyrtus tomentosa. Tomentodione N is the first example of a β-triketone unit coupled with an isoamyl alcohol through a furan fused-ring, and tomentodiones N, S, T were three racemates. The undescribed structures were elucidated by means of spectroscopic, X-ray diffraction, electronic circular dichroism calculation, and chemical methods. In addition, the isolated compounds were determined for the cytotoxic activities on HeLa cells and anti-inflammatory activities in LPS-stimulated RAW 264.7 cells.

Four new ent-kaurane diterpenes with chiral epoxyangelate moieties, (2′R,3′R)-3α-(2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (1), (2′S,3′S)-3α-(2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (2), (2′S,3′R)-3α-(2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (3) and (2′R,3′S)-3α-(2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (4), along with eight known diterpenes (5−12), were isolated from Wedelia prostrata. The absolute configurations of the new structures were determined by X-ray crystallography, ECD calculations and chemical methods. All compounds were evaluated for their cytotoxicity activities on human HepG-2 cells, with IC50 values of 11.72 ± 0.22 μmol/L to 54.75 ± 1.12 μmol/L.

Dryopteris crassirhizoma Nakai (Dryopteridaceae), a thick-stemmed wood fern, is a semi-evergreen plant mainly distributed in North and Northeast China. It is of great value in horticultural and medicinal applications. In this study, five β-tocopherol derivatives, drycrasspherols A–E (1–5), with three kinds of skeletons, were isolated from the rhizomes of Dryopteris crassirhizoma. Compounds 1–2 represent the basic architecture featuring a phenol motif fused with the phytyl-type diterpene via a pyran ring, compounds 3–4 possess an unprecedented tetracyclic system in which a 4-methylcyclohexanone is incorporated into the base unit of 1. Interestingly, compound 5 is a novel dimer constructed from two monomers via a pyran ring to form a pentacyclic system. These structures were elucidated by comprehensive spectroscopic data and quantum chemical electronic circular dichroism (ECD) calculations. Importantly, compound 1 exhibited the comparable anti-respiratory syncytial virus activity with an IC50 value of 6.50 ± 1.25 μM to the positive control ribavirin. This study suggested the rhizomes of D. crassirhizoma as well as the β-tocopherol derivatives had new potential applications in pharmaceutical industry.

Seven sesquiterpene lactones, 8-O-methacryloylelephanpane, 2,4-bis-O-methyl-8-O-methacryloylelephanpane, 4-O-ethyl-8-O-methacryloylelephanpane, 8-O-methacryloylisoelephanpane, 2-O-demethyltomenphantopin C, molephantin A, molephantin B, along with ten known ones, were isolated from Elephantopus mollis (Asteraceae). Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HRESIMS, 1D and 2D NMR). The isolates were evaluated for their anti-inflammatory activities on LPS-stimulated RAW 264.7 cells, and all tested compounds exhibited potent anti-inflammatory effects with IC50 values of 0.57 ± 0.17 to 14.34 ± 1.61 μM, except that compound tomenphantopin C exhibited moderate anti-inflammatory activity with IC50 values of 59.97 ± 1.53 μM.

Two novel diterpenoid alkaloids, grandiflodines A and B (1 and 2), were isolated from Delphinium grandiflorum. Compound 1 represents a rare hetisine-type C20-diterpenoid alkaloid in which the bond between the atoms of N and C-17 is broken. Compound 2 features an unusual lycoctonine-type C19-diterpenoid alkaloid skeleton with the cleavage of N–C19 and C7–C17 bonds, and the construction of the N–C7 bond. Structural elucidations of the isolates were performed by spectroscopic analysis, X-ray diffraction and comparison with the literature. These compounds were tested for their antiviral and anti-inflammatory activities.

Phytochemical investigation of the ethanol extract from the rhizomes of Paris polyphylla var. yunnanensis led to the isolation of three steroid saponins (1–3) and two triterpenoid saponins (4, 5). Among them, compound 1 is a new steroid saponin, and 3–5 were obtained for the first time from the genus Paris. Their structures were elucidated on the basis of extensive analyses of spectroscopic data including IR, UV, MS, and 1D and 2D NMR. All of these compounds were tested for their cytotoxic activities on human nasopharyngeal cancer cells (CNE) and antiviral activities against respiratory syncytial virus (RSV). Steroidal saponins 1 and 2 showed moderate effects on CNE cells, with IC50 values 32.56 and 33.10 μM, respectively.

Two new isoquinoline alkaloids, 6 R,6aS-N-nantenine N��-oxide (1), 6S,6aS-N-nantenine N��-oxide (2), along with nine known alkaloids, nantenine (3), oxonantenine (4), protopine (5), nornantenine (6), N-methyl-laurotetanine (7), isocorydine (8), O-methyflavinantine (9), N-methyl-2,3,6-trimethoxymorphinan-dien-7-one N��-oxide (10) and (+)-10-O-methylhernovine N��-oxide (11) were isolated from the seeds of Nandina domestica. Their structures were elucidated by extensive analyses of spectroscopic data (IR, UV, HRESIMS, 1 D and 2 D NMR), ECD calculation and comparison with the related literatures. In addition, the cytotoxicity against A549 cells of these alkaloids was determined by the MTT assay.

Three new diterpenoids, including one labdane diterpenoid (1) and two cembrane diterpenoids (2–3), were isolated from the aerial parts of Croton laui, along with four known analogues (4–7). Their structures were elucidated by spectroscopic analysis and comparison with literature data. All compounds were evaluated for their cytotoxicity against two tumour cell lines.

Three novel sesquiterpenoid-based meroterpenoids, drychampones A-C (1-3, respectively), were isolated from Dryopteris championii. Compounds 1 and 3 possessed a novel carbon skeleton which was constructed by an 11/6/6 ring system coupled with a pyronone moiety, and 1-3 were three racemates. Their structures and absolute configurations were elucidated by NMR, MS, and computational methods. The hypothetical biosynthetic pathways of these meroterpenoids and their antibacterial activities were also discussed.

The rhizome of Dryopteris crassirhizoma Nakai is an important traditional Chinese medicine listed in Chinese Pharmacopoeia for the treatment of parasitic infestation and viral diseases. In this work, ten enantiomeric pairs of new acylphloroglucinol meroterpenoids, (±)-dryocrassoids A − J [(±)-1−10], along with six known acylphloroglucinols (11−16) were isolated from the rhizomes of D. crassirhizoma. Notably, these new enantiomers were the first examples of meroterpenoids constructed by acylphloroglucinols and nerolidol-type sesquiterpenes, while (±)-1a/1b, (±)-2a/2b, (±)-4a/4b were obtained as the inseparable interconverting mixtures of keto and enol tautomers. The new structures and absolute configurations were identified by the interpretation of high resolution electron spray ionization mass spectrum (HRESIMS), nuclear magnetic resonance (NMR) spectroscopic data, and quantum chemical electronic circular dichroism (ECD) calculations. In addition, these compounds were assayed for the in vitro antiviral activities against herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), and respiratory syncytial virus (RSV). The results indicated that most of the compounds showed anti-HSV-1 and anti-RSV effects to different extent under the concentration of 100 μM. This study provided evidences for further study and utilization of D. crassirhizoma in medicinal products.

Diffraction gratings have been widely used in waveguides. They can transmit light beams or images from the in-coupling end to the out-coupling end at predetermined positions. However, when they are applied to augmented reality and virtual reality with large field of view and color light sources, there will arise some problems such as mismatch and missing field of view, non-uniform emission, and others. Therefore, starting from these physical problems, the upper limit of the field of view for diffractive waveguide and the complete theoretical boundary formula of the field of view are derived, and on this basis, in-depth research is conducted on monochromatic waves and multicolor waves, respectively. It is concluded that the single-layer diffractive waveguide supports the theoretical upper limit of the monochromatic wave field angle of about 48° under normal high refractive index of n = 1.75, and supports the theoretical upper limit of the multicolor wave field angle of 26.4° for coefficient q = 1.3. Clearly, a larger field of view requires a higher refractive index n and a smaller q value. The boundary conditions of field integrity indicate that reducing the maximum diffraction angle of the long wave and thinning the thickness of the waveguide layer can solve the problem of missing field of view. The practical maximum diffraction angle generally does not exceed 75°, and the thickness of the waveguide layer is about 0.5 to 1.0 mm generally based on the incident field of view. Finally, a method of expanding each total internal reflection field of view into a ray tracing diagram and a distribution function of pupils to receive light energy at various angles are obtained. In this way, the optimal position of the out-coupling grating region can be achieved, and the inverse of the distribution function is used to constrain the angular distribution of the projected light or the grating efficiency, and then receiving uniform exit image at any position becomes possible. The uniformity of the monochromatic waveguide increases from 0.27 to 0.15, and the uniformity of the long wave in the single grating multicolor waveguide rises from 0.4 to 0.28. The results of these studies will undoubtedly help to solve the problem in the diffractive waveguides used in large field of view and multicolor light.

Three new prenylated acetophenone derivatives, acronyculatin P (1), acronyculatin Q (2), and acronyculatin R (3) were isolated from the leaves of Acronychia oligophlebia. Their structures were identified by extensive analyses of spectroscopic data (IR, UV, ESI-HRMS, 1D and 2D NMR) and comparison with the literatures. In addition, the cytotoxic activity against MCF-7 cells of the compounds were evaluated by the MTT assay and the IC50 values were 56.8, 40.4 and 69.1 μM, respectively.

We report a new scenario of the time-of-flight technique in which fast neutrons and delayed gamma-ray signals were both recorded in a millisecond time window in harsh environments induced by high-intensity lasers. The delayed gamma signals, arriving far later than the original fast neutron and often being ignored previously, were identified to be the results of radiative captures of thermalized neutrons. The linear correlation between the gamma photon number and the fast neutron yield shows that these delayed gamma events can be employed for neutron diagnosis. This method can reduce the detecting efficiency dropping problem caused by prompt high-flux gamma radiation and provides a new way for neutron diagnosing in high-intensity laser-target interaction experiments.

Seven new acetophenone derivatives (acroliones A - G, 1 - 7) and three known ones (8 - 10) were isolated from the leaves of Acronychia oligophlebia. Their structures were elucidated based on extensive spectroscopic analyses (IR, UV, HR-ESI-MS, 1D- and 2D-NMR), X-ray diffraction and comparison with literature data. The anti-inflammatory and antioxidant activities of all isolates were evaluated.

Three new prenylated acetophenone derivatives, acronyculatin P (1), acronyculatin Q (2), and acronyculatin R (3) were isolated from the leaves of Acronychia oligophlebia. Their structures were identified by extensive analyses of spectroscopic data (IR, UV, ESI-HRMS, 1D and 2D NMR) and comparison with the literatures. In addition, the cytotoxic activity against MCF-7 cells of the compounds were evaluated by the MTT assay and the IC50 values were 56.8, 40.4 and 69.1 μM, respectively.

The Shen-Guang II Upgrade (SG-II-U) laser facility consists of eight high-power nanosecond laser beams and one short-pulse picosecond petawatt laser. It is designed for the study of inertial confinement fusion (ICF), especially for conducting fast ignition (FI) research in China and other basic science experiments. To perform FI successfully with hohlraum targets containing a golden cone, the long-pulse beam and cylindrical hohlraum as well as the short-pulse beam and cone target alignment must satisfy tight specifications (30 and $20~\unicode[STIX]{x03BC}\text{m}$ rms for each case). To explore new ICF ignition targets with six laser entrance holes (LEHs), a rotation sensor was adapted to meet the requirements of a three-dimensional target and correct beam alignment. In this paper, the strategy for aligning the nanosecond beam based on target alignment sensor (TAS) is introduced and improved to meet requirements of the picosecond lasers and the new six LEHs hohlraum targets in the SG-II-U facility. The expected performance of the alignment system is presented, and the alignment error is also discussed.

We present laboratory measurement and theoretical analysis of silicon K-shell lines in plasmas produced by Shenguang II laser facility, and discuss the application of line ratios to diagnose the electron density and temperature of laser plasmas. Two types of shots were carried out to interpret silicon plasma spectra under two conditions, and the spectra from 6.6 Å to 6.85 Å were measured. The radiative-collisional code based on the flexible atomic code (RCF) is used to identify the lines, and it also well simulates the experimental spectra. Satellite lines, which are populated by dielectron capture and large radiative decay rate, influence the spectrum profile significantly. Because of the blending of lines, the traditional $G$ value and $R$ value are not applicable in diagnosing electron temperature and density of plasma. We take the contribution of satellite lines into the calculation of line ratios of He-$\unicode[STIX]{x1D6FC}$ lines, and discuss their relations with the electron temperature and density.

As a promising new way to generate a controllable strong magnetic field, laser-driven magnetic coils have attracted interest in many research fields. In 2013, a kilotesla level magnetic field was achieved at the Gekko XII laser facility with a capacitor–coil target. A similar approach has been adopted in a number of laboratories, with a variety of targets of different shapes. The peak strength of the magnetic field varies from a few tesla to kilotesla, with different spatio-temporal ranges. The differences are determined by the target geometry and the parameters of the incident laser. Here we present a review of the results of recent experimental studies of laser-driven magnetic field generation, as well as a discussion of the diagnostic techniques required for such rapidly changing magnetic fields. As an extension of the magnetic field generation, some applications are discussed.

Astrophysical collisionless shocks are amazing phenomena in space and astrophysical plasmas, where supersonic flows generate electromagnetic fields through instabilities and particles can be accelerated to high energy cosmic rays. Until now, understanding these micro-processes is still a challenge despite rich astrophysical observation data have been obtained. Laboratory astrophysics, a new route to study the astrophysics, allows us to investigate them at similar extreme physical conditions in laboratory. Here we will review the recent progress of the collisionless shock experiments performed at SG-II laser facility in China. The evolution of the electrostatic shocks and Weibel-type/filamentation instabilities are observed. Inspired by the configurations of the counter-streaming plasma flows, we also carry out a novel plasma collider to generate energetic neutrons relevant to the astrophysical nuclear reactions.

In high power laser facility for inertial confinement fusion research, final optics assembly (FOA) plays a critical role in the frequency conversion, beam focusing, color separation, beam sampling and debris shielding. The design and performance of FOA in SG-II Upgrade laser facility are mainly introduced here. Due to the limited space and short focal length, a coaxial aspheric wedged focus lens is designed and applied in the FOA configuration. Then the ghost image analysis, the focus characteristic analysis, the B integral control design and the optomechanical design are carried out in the FOA design phase. In order to ensure the FOA performance, two key technologies are developed including measurement and adjustment technique of the wedged focus lens and the stray light management technique based on ground glass. Experimental results show that the design specifications including laser fluence, frequency conversion efficiency and perforation efficiency of the focus spot have been achieved, which meet the requirements of physical experiments well.

Three new diterpenoids, including one clerodane diterpenoid 1 and two linear diterpenoids 2 and 3, were isolated from the aerial parts of Croton laui, along with four known compounds 4–7. Structura...

Three new eudesmanolides, prostrolides A–C (1–3), along with six known compounds were isolated from the herbs of Wedelia prostrata (Asteraceae). The structures were determined by extensive analysis of their spectroscopic data (IR, UV, HRESIMS, 1D and 2D NMR). The isolated compounds were evaluated for their cytotoxic activity on human hepatocellular carcinoma HepG2 cells. All isolates exhibited cytotoxic activities with IC50 values of 4.60 ± 0.17 to 27.23 ± 0.36 µM.

Six new acylphloroglucinols (1-6) were isolated from Dryopteris championii. Their structures were established on the basis of extensive analysis of spectroscopic data and comparison with reported data. The antibacterial activities of the isolates were evaluated against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Dickeya zeae. This article is protected by copyright. All rights reserved.

Microwave radiation in several gigahertz frequency band is a common phenomenon in laser-plasma interactions. It can last hundreds of nanoseconds and cause huge electromagnetic pulse disturbances to electrical devices in experiments. It has been found that the microwave radiation might originate from the oscillation of charged chambers, the return current on target holders, the dipole radiation, the quadrupole radiation, and the electron bunch emitted from the plasma to the vacuum. The microwave radiation waveform, frequency spectrum, and intensity depend on many factors such as laser pulse, target, and chamber parameter. To distinguish the microwave radiation mechanisms, the influence of the experimental parameters on the radiation characteristics should be investigated systematically. In this paper we investigate the microwave radiation influenced by the laser intensity in nanosecond laser-plasma interactions. It is found that the microwave radiation intensity varies nonmonotonically with the laser intensity. For the lower laser intensity, the radiation intensity first increases and then decreases with laser intensity increasing, the radiation field continuously oscillates in tens of nanoseconds, and the radiation spectrum contains two components below and above 0.3 GHz, respectively. For the higher laser intensity, the radiation intensity increases with the laser intensity increasing, the radiation field has a unipolar radiation lasting tens of nanoseconds, and the radiation spectrum mainly includes the component below 0.3 GHz. The waveform and spectrum analysis show that these phenomena are due to the difference of the radiation mechanisms at different laser intensities. The frequency component below and above 0.3 GHz are induced by the electron bunch emitted from the plasma to the vacuum and the dipole radiation respectively. At low laser intensity, both the dipole radiation and the electron bunch emitted from the plasma contribute to the microwave radiation. At high laser intensity, the microwave radiation is mainly produced by the electron beam emitted from the plasma to the vacuum. This work is significant for understanding the microwave radiation mechanisms in nanosecond laser-plasma interactions, and implies the potential to provide a reference to the diagnosing of the escape electrons and the sheath field on the target surface by the microwave radiation in laser-plasma interaction.

Two new sesquiterpenoids, strophanthoids A and B (1 and 2), along with seven known cardiac glycosides were isolated from the roots of Strophanthus divaricatus. Their structures were elucidated on t...

The driving mechanism of solar flares and coronal mass ejections is a topic of ongoing debate, apart from the consensus that magnetic reconnection plays a key role during the impulsive process. While present solar research mostly depends on observations and theoretical models, laboratory experiments based on high-energy density facilities provide the third method for quantitatively comparing astrophysical observations and models with data achieved in experimental settings. In this article, we show laboratory modeling of solar flares and coronal mass ejections by constructing the magnetic reconnection system with two mutually approaching laser-produced plasmas circumfused of self-generated megagauss magnetic fields. Due to the Euler similarity between the laboratory and solar plasma systems, the present experiments demonstrate the morphological reproduction of flares and coronal mass ejections in solar observations in a scaled sense, and confirm the theory and model predictions about the current-sheet-born anomalous plasmoid as the initial stage of coronal mass ejections, and the behavior of moving-away plasmoid stretching the primary reconnected field lines into a secondary current sheet conjoined with two bright ridges identified as solar flares.

Five new diterpenoid alkaloids, ajacisines A–E (1–5), were isolated from Delphinium ajacis, along with seven known alkaloids (6–12). On the basis of their spectral data (IR, UV, HR-ESI-MS, 1D and 2D NMR) and chemical properties, the structures of compounds 1–12 were identified. All isolated compounds were evaluated for their in vitro antiviral activities against respiratory syncytial virus, and compounds 3–5 and 8 exhibited moderate to weak effects with IC50 values of 75.2 ± 1.1, 35.1 ± 0.6, 10.1 ± 0.3, and 50.2 ± 0.5 µM, respectively.

Nine new labdane diterpenoids (1-9) were isolated from the aerial parts of Croton laui, along with eight known analogues (10-17). Their structures were identified on the basis of the spectral data (IR, UV, HRESIMS, 1D and 2D NMR), and the structure of 8 was confirmed by single crystal X-ray diffraction analyses. In addition, compounds 1, 4, 7, 8, and 14 showed weak anti-inflammatory activities in LPS-stimulated RAW 264.7 cells.

Six new pentacyclic triterpenoids were isolated from the fruit of Camptotheca acuminata. The chemical structures of the new compounds were elucidated by extensive spectroscopic analysis including HR-ESI-MS, IR, UV, 1D- and 2D-NMR. Moreover, the antibacterial activities of compounds 1, 2, 4, 5, and 6 were evaluated against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Dickeya zeae. All these tested compounds showed moderate antibacterial activity against Bacillus subtilis and Dickeya zeae.

Two new sesquiterpenoids, strophanthoids A and B (1 and 2), along with seven known cardiac glycosides were isolated from the roots of Strophanthus divaricatus. Their structures were elucidated on t...

This article raises an improved program of adding Pseudo-Satellite’s pseudo-range measurement and setting best configuration for Pseudo-Satellite in mentioned program on the basis of existing Binary System [1]. Through comparison and analysis of improved Tri-satellite System and existing Binary System, this article proves that it shortens location time and location precision by adding Pseudo-Satellite to Binary Navigation Location System. Finally this conclusion is approved by simulating Mathematical model using software.