Sesquiterpene lactones from Tithonia diversifolia with ferroptosis-inducing activities.

Eight previously undescribed sesquiterpene lactones (1-8), together with six known ones (9-14) were isolated from the aerial parts of Tithonia diversifolia (Hemsl.) A. Gray. The absolute configurations of these compounds were elucidated using HRMS, NMR spectroscopy, optical rotation measurements, X-ray crystallography, and ECD. Among them, sesquiterpene lactones 2-4 share a unique carbon skeleton with a rare C-3/C-4 ring-opened structure. Compounds 1 and 8 showed moderate inhibitory effects toward CT26 murine colon carcinoma cells by promoting lipid ROS production, highlighting their potential as ferroptosis inducers.

Gut microorganisms of Locusta migratoria in various life stages and its possible influence on cellulose digestibility.

Locusta migratoria is an important phytophagous pest, and its gut microbial communities play an important role in cellulose degradation. In this study, the gut microbial and cellulose digestibility dynamics of Locusta migratoria were jointly analyzed using high-throughput sequencing and anthrone colorimetry. The results showed that the gut microbial diversity and cellulose digestibility across life stages were dynamically changing. The species richness of gut bacteria was significantly higher in eggs than in larvae and imago, the species richness and cellulose digestibility of gut bacteria were significantly higher in early larvae (first and second instars) than in late larvae (third to fifth instars), and the diversity of gut bacteria and cellulose digestibility were significantly higher in imago than in late larvae. There is a correlation between the dynamics of gut bacterial communities and cellulose digestibility. Enterobacter, Lactococcus, and Pseudomonas are the most abundant genera throughout all life stages. Six strains of highly efficient cellulolytic bacteria were screened, which were dominant gut bacteria. Carboxymethyl cellulase activity (CMCA) and filter paper activity (FPA) experiments revealed that Pseudomonas had the highest cellulase enzyme activity. This study provides a new way for the screening of cellulolytic bacteria and lays the foundation for developing insects with significant biomass into cellulose-degrading bioreactors. IMPORTANCE: Cellulose is the most abundant and cheapest renewable resource in nature, but its degradation is difficult, so finding efficient cellulose degradation methods is an urgent challenge. Locusta migratoria is a large group of agricultural pests, and the large number of microorganisms that inhabit their intestinal tracts play an important role in cellulose degradation. We analyzed the dynamics of Locusta migratoria gut microbial communities and cellulose digestibility using a combination of high-throughput sequencing technology and anthrone colorimetry. The results revealed that the gut microbial diversity and cellulose digestibility were dynamically changed at different life stages. In addition, we explored the intestinal bacterial community of Locusta migratoria across life stages and its correlation with cellulose digestibility. The dominant bacterial genera at different life stages of Locusta migratoria were uncovered and their carboxymethyl cellulase activity (CMCA) and filter paper activity (FPA) were determined. This study provides a new avenue for screening cellulolytic bacteria and lays the foundation for developing insects with significant biomass into cellulose-degrading bioreactors.

Eighteen iridoids from the roots and rhizomes of Valeriana jatamansi and their protective effects against α-hemolysin.

Thirteen previously undescribed iridoids (1-13), together with five known iridoids (14-18) were isolated from the roots and rhizomes of Valeriana jatamansi Jones. Their structures with absolute configurations were elucidated by analysis of MS, NMR, optical rotation and their experimental and calculated electronic circular dichroism spectra. All of the isolated compounds were tested for their protective effects against α-hemolysin-induced cell death in A549 cells. Compounds 14, 16 and 17 showed moderate protective effects, and compounds 15 and 18 showed weak protective effects.

Dimeric ent-kauranoids isolated from Isodon japonica var. Glaucocalyx and their anti-inflammatory activities.

The phytochemical investigation of the aerial parts of Isodon japonica var. glaucocalyx afforded four undescribed (glaucocalyxin O-R, 1-4) and six known ent-kauranoids (5-10). Their structures were established using NMR and MS measurements. Compounds 1 and 2 are dimeric ent-kaurane-type diterpenoids. Moreover, the plausible biogenetic pathways for compounds 1 and 2 were proposed as Michael addition between two monomers. Eight compounds were assayed for their anti-inflammatory activity by evaluating NO production in LPS-induced RAW 267.4 cells, and compounds 7, 8 and 9 exhibited relatively remarkable anti-inflammatory activities at 10 µM.

Enhanced Sensing Mechanism Based on Shifting an Exceptional Point.

Non-Hermitian systems associated with exceptional points (EPs) are expected to demonstrate a giant response enhancement for various sensors. The widely investigated enhancement mechanism based on diverging from an EP should destroy the EP and further limits its applications for multiple sensing scenarios in a time sequence. To break the above limit, here, we proposed a new enhanced sensing mechanism based on shifting an EP. Different from the mechanism of diverging from an EP, our scheme is an EP nondemolition and the giant enhancement of response is acquired by a slight shift of the EP along the parameter axis induced by perturbation. The new sensing mechanism can promise the most effective response enhancement for all sensors in the case of multiple sensing in a time sequence. To verify our sensing mechanism, we construct a mass sensor and a gyroscope with concrete physical implementations. Our work will deepen the understanding of EP-based sensing and inspire designing various high-sensitivity sensors in different physical systems.

Isolation and characterization of intestinal bacteria associated with cellulose degradation in grasshoppers (Orthoptera).

Insect gut bacteria play an essential role in the nutritional metabolism, growth, and development of insects. Grasshoppers (Orthoptera) are cellulose-rich plant-feeding pests. Although the biological potential of grasshopper gut microorganisms to assist cellulose decomposition is well established, microbial resources for efficient degradation of cellulose biomass are still scarce and need to be developed. In this study, we used selective media to isolate cellulose-degrading bacteria from the intestines of Atractomorpha sinensis, Trilophidia annulata, Sphingonotus mongolicus, and Calliptamus abbreviatus. Phylogenetic analysis based on the maximum likelihood method using 16S rDNA sequencing sequences to identify bacteria revealed the isolation of 11 strains belonging to 3 genera, including Klebsiella, Aeromonas, and Bacillus. The degradability of the isolates to cellulose was then determined by the DNS colorimetric method, and the results showed that Bacillus had the highest degradation rate. The elucidation of microbial cellulose degradation capacity in grasshoppers not only contributes to the understanding of multiple plant-insect-microbe interactions, but also provides a valuable microbial resource for solving the biomass conversion of cellulose species problem.

Heterodyne detection of backscattering for whispering-gallery-mode sensors.

Whispering-gallery-mode (WGM) microcavities have shown significant applications in nanoparticle sensing for environmental monitoring and biological analysis. However, the enhancement of detection resolution often calls for active cavities or elaborate structural designs, leading to an increase of fabrication complexity and cost. Herein, heterodyne amplification is implemented in WGM microsensors based on backscattering detection mechanism. By interfering with an exotic reference laser, the reflecting light backscattered by perturbation targets can be strongly enlarged, yielding an easy-to-resolve and consequently sensitive microsensor. The dependence of detection laser frequency has also been characterized with the assistance of optothermal dynamics. We show that exploiting heterodyne interferometry boosts the detection of weak signals in microresonator systems and provides a fertile ground for optical microsensor development.

Demonstration of Yb3+-doped and Er3+/Yb3+-codoped on-chip microsphere lasers.

Rare-earth-doped on-chip microlasers are of great significance in both fundamental research and engineering. To the best of our knowledge, this is the first report of Yb3+-doped and Er3+/Yb3+-codoped on-chip microsphere lasers fabricated via sol-gel synthesis. Laser emissions were observed in a band around 1040 nm in both Yb3+-doped and Er3+/Yb3+-codoped resonators pumped at 980 nm and had measured ultralow thresholds of 5.2 µW and 0.6 µW, respectively. Both single-mode and multi-mode emissions were recorded around 1040 nm in these lasers. Single-mode and two-mode emissions were obtained at 1550 nm in the Er3+/Yb3+-codoped lasers when pumped at 980 nm and 1460 nm, respectively. Furthermore, quality factors induced by different loss mechanisms in the microsphere lasers are theoretically estimated. These resonators are expected to contribute to the high-density integration of on-chip silica-based microlasers.

Scalable higher-order exceptional surface with passive resonators.

The sensitivity of perturbation sensing can be effectively enhanced with higher-order exceptional points due to the nonlinear response to frequency splitting. However, experimental implementation is challenging since all the parameters need to be precisely prepared. The emergence of an exceptional surface (ES) improves the robustness of the system to the external environment, while maintaining the same sensitivity. Here, we propose, to our knowledge, the first scalable protocol for realizing a photonic high-order ES with passive resonators. By adding one or more additional passive resonators in the low-order ES photonic system, the three- or arbitrary N-order ES is constructed and proved to be easily realized in experiment. We show that the sensitivity is enhanced and the experimental demonstration is more resilient against fabrication errors. The additional phase-modulation effect is also investigated.

Color-detuning-dynamics-based quantum sensing with dressed states driving.

Exploring quantum technology to precisely measure physical quantities is a meaningful task for practical scientific researches. Here, we propose a novel quantum sensing model based on color detuning dynamics with dressed states driving (DSD) in stimulated Raman adiabatic passage. The model is valid for sensing different physical quantities, such as magnetic field, mass, rotation and so on. For different sensors, the used systems can range from macroscopic scale, e.g. optomechanical systems, to microscopic nanoscale, e.g. solid spin systems. The dynamics of color detuning of DSD passage indicates the sensitivity of sensors can be enhanced by tuning system with more adiabatic or accelerated processes in different color detuning regimes. To show application examples, we apply our approach to build optomechanical mass sensor and solid spin magnetometer with practical parameters.

Phase-controlled dual-wavelength resonance in a self-coupling whispering-gallery-mode microcavity.

We report a novel, to the best of our knowledge, way to achieve phase-controlled dual-wavelength resonance based on whispering-gallery-mode (WGM) microcavities experimentally. With the help of a feedback waveguide, not only two optical pathways but also a unidirectional coupling between counter-propagating waves are formed, which is the requirement of all-optical analogues of electromagnetically induced transparency and Autler-Townes splitting. By adjusting the accumulating phase introduced from the fiber waveguide, we observe the signal lineshape changes from symmetric to asymmetric, i.e., the resonant transmission and extinction ratio of two splitting modes can be controlled, which brings a new degree of freedom to the WGM resonator system. These results may boost the development of quantum state control and pave the way for reconfiguring devices such as narrow-band filters.

Identification of Transient Receptor Potential Vanilloid 3 Antagonists from Achillea alpina L. and Separation by Liquid-Liquid-Refining Extraction and High-Speed Counter-Current Chromatography.

Bioassay-guided fractionation of the ethanol extract of whole herbs of Achillea alpina led to the isolation of isochlorogenic acids A and B as transient receptor potential vanilloid 3 (TRPV3) channel antagonists by using a calcium fluorescent assay. The structures were identified by spectroscopic analysis and the inhibitory activities of isochlorogenic acids A and B were confirmed by whole-cell patch clamp recordings of human embryonic kidney 293 (HEK293) cells expressing human TRPV3. Molecular docking results revealed that these two compounds reside in the same active pocket of human TRPV3 channel protein with lower binding energy than the agonist 2-aminoethoxydiphenyl borate (2-APB). High-speed counter-current chromatography (HSCCC) coupled with a liquid-liquid extraction approach was successfully established for the separation of isochlorogenic acids A and B from the whole herbs of A. alpina. Ethyl acetate and n-hexane-ethyl acetate-water (3:3:4 and 1:5:4, v/v/v) were selected as liquid-liquid extraction solvent systems to remove high- and low-polarity impurities in the mixture. Sixty g of ethanol extract was refined by solvent partition to yield 1.7 g of the enriched fraction, of which 480 mg in turn obtained 52.5 mg of isochlorogenic acid B (purity 98.3%) and 37.6 mg isochlorogenic acid A (purity 96.2%) after HSCCC with n-hexane-ethyl acetate-water containing 1% acetic acid (1:4:8, v/v/v).

Manipulation of optomechanically induced transparency and absorption by indirectly coupling to an auxiliary cavity mode.

We theoretically study the optomechanically induced transparency (OMIT) and absorption (OMIA) phenomena in a single microcavity optomechanical system, assisted by an indirectly coupled auxiliary cavity mode. We show that the interference effect between the two optical modes plays an important role and can be used to control the multiple-pathway induced destructive or constructive interference effect. The three-pathway interference could induce an absorption dip within the transparent window in the red sideband driving regime, while we can switch back and forth between OMIT and OMIA with the four-pathway interference. The conversion between the transparency peak and absorption dip can be achieved by tuning the relative amplitude and phase of the multiple light paths interference. Our system proposes a new platform to realize multiple pathways induced transparency and absorption in a single microcavity and a feasible way for realizing all-optical information processing.

Differentiation of sow and mouse ovarian granulosa cells exposed to zearalenone in vitro using RNA-seq gene expression.

Zearalenone (ZEA), a natural contaminant found in feed, has been shown to have a negative impact on domestic animal reproduction, particularly in pigs. There are species-specific differences in the ZEA-induced toxicity pattern. Here, we investigated the different biological effects of ZEA exposure on porcine and mouse granulosa cells, using RNA-seq analysis. We treated murine and porcine granulosa cells with 10 µM and 30 µM ZEA during 72 h of culturing, in vitro. The results showed that 10 µM ZEA exposure significantly altered mitosis associated genes in porcine granulosa cells, while the same treatment significantly altered the steroidogenesis associated genes in mouse granulosa cells. Exposure to 30 µM ZEA resulted in significantly up-regulated expression of inflammatory related genes in porcine granulosa cells as well as the cancer related genes in mouse granulosa cells. Similarly, 30 µM ZEA exposure significantly decreased the expression of tumor suppressor factors in the mouse granulosa cells. Furthermore, immunofluorescence, RT-qPCR as well as western-blot analysis verified the different expression of related genes in ZEA exposed porcine and mouse granulosa cells. Collectively, these results illustrate the presence of species differences with regards to ZEA effects between porcine and mouse ovarian granulosa cells, in vitro.

Fabrication of a microtoroidal resonator with picometer precise resonant wavelength.

Fabricating an optical microresonator with precise resonant wavelength is of significant importance for fundamental research and practical applications. Here, we develop an effective method to fabricate ultra-high Q microtoroid with picometer-precise resonant wavelength. Our method adds a tuning reflow process, using low-power CO2 laser pulses, to the traditional fabrication process. It can tailor resonant wavelength to a red or blue direction by choosing a proper laser power. Also, this shift can be controlled by the exposure time. Meanwhile, quality factor remains nearly unchanged during this tailoring process. Our method can greatly reduce the difficulties of experiments where precise resonances are required.

Experimental quantum secure direct communication with single photons.

Quantum secure direct communication is an important mode of quantum communication in which secret messages are securely communicated directly over a quantum channel. Quantum secure direct communication is also a basic cryptographic primitive for constructing other quantum communication tasks, such as quantum authentication and quantum dialog. Here, we report the first experimental demonstration of quantum secure direct communication based on the DL04 protocol and equipped with single-photon frequency coding that explicitly demonstrated block transmission. In our experiment, we provided 16 different frequency channels, equivalent to a nibble of four-bit binary numbers for direct information transmission. The experiment firmly demonstrated the feasibility of quantum secure direct communication in the presence of noise and loss.

Insulin regulates primordial-follicle assembly in vitro by affecting germ-cell apoptosis and elevating oestrogen.

Insulin is a protein secreted by pancreatic ß-cells, which plays an important role in the regulation of ovarian function. However, the specific molecular mechanism of its function remains largely unknown. This study aimed to assess the effect of insulin on mouse folliculogenesis using an in vitro ovary-culture model. The results demonstrated that insulin promoted the proliferation of ovarian granulosa cells in vitro, and thereby accelerated the progress of folliculogenesis (the percentage of oocytes in cysts declined from 42.6% to 29.3%); however, the percentage of apoptotic oocytes increased after insulin treatment. Further investigation indicated that apoptosis occurred mainly in germ-cell cysts. After 3 days of insulin treatment, oestrogen in the culture medium of mouse ovaries significantly increased (P<0.01), while the lower dose of oestrogen promoted primordial-follicle assembly in vitro. In conclusion, insulin promoted folliculogenesis by facilitating germ-cell apoptosis within the cysts and upregulating oestrogen levels.

Exposure to diethylhexyl phthalate (DEHP) results in a heritable modification of imprint genes DNA methylation in mouse oocytes.

Diethylhexyl phthalate (DEHP) is an estrogen-like compound widely used as a plasticizer in commercial products and is present in medical devices, and common household items. It is considered an endocrine disruptor since studies on experimental animals clearly show that exposure to DEHP can alter epigenetics of germ cells. This study was designed to assess the effects of DEHP on DNA methylation of imprinting genes in germ cells from fetal and adult mouse. Pregnant mice were treated with DEHP at doses of 0 and 40 µg DEHP/kg body weight/day from 0.5 to 18.5 day post coitum. The data revealed DEHP exposure significantly reduced the percentage of methylated CpG sites in Igf2r and Peg3 differentially methylated regions (DMRs) in primordial germ cells from female and male fetal mouse, particularly, in the oocytes of 21 dpp mice (F1), which were produced by the pregnant micetreated with DEHP. More surprisingly, the modification of the DNA methylation of imprinted genes in F1 mouse oocytes was heritable to F2 offspring which exhibit lower percentages of methylated CpG sites in imprinted genes DMRs. In conclusion, DEHP exposure can affect the DNA methylation of imprinting genes not only in fetal mouse germ cells and growing oocytes, but also in offspring's oocytes.

Di-(2-ethylhexyl) phthalate and bisphenol A exposure impairs mouse primordial follicle assembly in vitro.

Bisphenol-A (BPA) and diethylhexyl phthalate (DEHP) are estrogenic compounds widely used in commercial plastic products. Previous studies have shown that exposure to such compounds have adverse effects on various aspects of mammalian reproduction including folliculogenesis. The objective of this study was to examine the effects of BPA and DEHP exposure on primordial follicle formation. We found that germ cell nest breakdown and primordial follicle assembly were significantly reduced when newborn mouse ovaries were exposed to 10 or 100 µM BPA and DEHP in vitro. Moreover, BPA and DEHP exposure increased the number of TUNEL positive oocytes and the mRNA level of the pro-apoptotic gene Bax in oocytes. These effects were associated with decreased expression of oocyte specific genes such as LIM homeobox 8 (Lhx8), factor in the germline alpha (Figla), spermatogenesis and oogenesis helix-loop-helix (Sohlh2), and newborn ovary homeobox (Nobox). Interestingly, BPA and DEHP exposure also prevented DNA demethylation of CpG sites of the Lhx8 gene in oocytes, a process normally associated with folliculogenesis. Finally, folliculogenesis was severely impaired in BPA and DEHP exposed ovaries after transplantation into the kidney capsules of immunodeficient mice. In conclusion, BPA and DEHP exposures impair mouse primordial follicle assembly in vitro.

Cloning and in vitro function analysis of codon-optimized FatI gene.

Currently, n-3 polyunsaturated fatty acids (n-3 PUFAs) have attracted great attention because of their biological significance to organisms. In addition, PUFAs show an obvious impact on prevention and treatment of various diseases. Because n-3 PUFAs cannot be endogenously synthesized by mammals, mammals have to rely on a dietary supplement for sufficient supply. The finding and application of the fatty acid dehydrogenase I (FatI) gene are expected to change the current situation because it can convert n-6 polyunsaturated fatty acids (n-6 PUFAs) to n-3 PUFAs. Meanwhile, the gradual maturation of transgenic technology makes it possible to produce transgenic animals that can synthesize n-3 PUFAs by themselves. In this study, the DNA coding sequence of FatI was synthesized by a chemical method after codon optimization according to the mammal's codon bias. The synthesized DNA sequence was introduced into Boer goat fetal fibroblasts by the constructed recombinant eukaryotic expression vector pcDNA3.1(+)-FatI. Boer goat fetal fibroblasts were transfected by electroporation, and the stable transfected cell lines were obtained by G418 selection. Genomic DNA PCR and Southern blot were applied to verify that the foreign gene FatI was integrated into the genome of the Boer goat fibroblasts. RT-PCR results showed the expression of FatI gene at the mRNA level. The fatty acid profile of cells carrying the FatI gene revealed an increase in total n-3 PUFAs (from 0.61 to 0.95), but a decrease in n-6 PUFAs (from 10.34 to 9.85), resulting in a remarkable increase in the n-3:n-6 ratio (from 0.059 to 0.096). The n-3:n-6 ratio had a 63.49 percent increase, which is a precursor of the response of n-3 desaturase activity of the FatI gene. The study may provide a practical tool for producing transgenic animals that can produce n-3 PUFAs by themselves, and we hope that the application will lay the foundation for animals producing n-3 PUFAs, which will benefit human nutrition and wellness.