AT2023lli: A Tidal Disruption Event with Prominent Optical Early Bump and Delayed Episodic X-ray Emission

High-cadence, multiwavelength observations have continuously revealed the diversity of tidal disruption events (TDEs), thus greatly advancing our knowledge and understanding of TDEs. In this work, we conducted an intensive optical-UV and X-ray follow-up campaign of TDE AT2023lli, and found a remarkable month-long bump in its UV/optical light curve nearly two months prior to maximum brightness. The bump represents the longest separation time from the main peak among known TDEs to date. The main UV/optical outburst declines as $t^{-4.10}$, making it one of the fastest decaying optically selected TDEs. Furthermore, we detected sporadic X-ray emission 30 days after the UV/optical peak, accompanied by a reduction in the period of inactivity. It is proposed that the UV/optical bump could be caused by the self-intersection of the stream debris, whereas the primary peak is generated by the reprocessed emission of the accretion process. In addition, our results suggest that episodic X-ray radiation during the initial phase of decline may be due to the patched obscurer surrounding the accretion disk, a phenomenon associated with the inhomogeneous reprocessing process. The double TDE scenario, in which two stars are disrupted in sequence, is also a possible explanation for producing the observed early bump and main peak. We anticipate that the multicolor light curves of TDEs, especially in the very early stages, and the underlying physics can be better understood in the near future with the assistance of dedicated surveys such as the deep high-cadence survey of the 2.5-meter Wide Field Survey Telescope (WFST).Comment: 14 pages, 8 figures,accepted for publication by ApJ

Formaldehyde Gas Sensors Fabricated with Polymer-Based Materials: A Review

Formaldehyde has been regarded as a common indoor pollutant and does great harm to human health, which has caused the relevant departments to pay attention to its accurate detection. At present, spectrophotometry, gas chromatography, liquid chromatography, and other methods have been proposed for formaldehyde detection. Among them, the gas sensor is especially suitable for common gaseous formaldehyde detection with the fastest response speed and the highest sensitivity. Compared with the formaldehyde sensors based on small molecules, the polymer-based sensor has higher selectivity but lower sensitivity because the polymer-based sensor can realize the specific detection of formaldehyde through a specific chemical reaction. Polymer-related formaldehyde sensors can be very versatile. They can be fabricated with a single polymer, molecularly imprinted polymers (MIP), polymer/metal-oxide composites, different polymers, polymer/biomass material composites, polymer/carbon material composites, and polymer composites with other materials. Almost all of these sensors can detect formaldehyde at ppb levels under laboratory conditions. Moreover, almost all polymer nanocomposite sensors have better sensitivity than single polymer sensors. However, the sensing performance of the sensor will be greatly reduced in a humid environment due to the sensitive coating on the gaseous formaldehyde sensor, which is mostly a hydrophilic polymer. At present, researchers are trying to improve the sensitive material or use humidity compensation methods to optimize the gaseous formaldehyde sensor. The improvement of the practical performance of formaldehyde sensors has great significance for improving indoor living environments

Essential Oil Derived From Eupatorium adenophorum Spreng. Mediates Anticancer Effect by Inhibiting STAT3 and AKT Activation to Induce Apoptosis in Hepatocellular Carcinoma

Eupatorium adenophorum Spreng. (EA) is a well-known noxious invasive species. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the essential oil derived from EA (EAEO) is mainly composed of sesquiterpenes. However, the pharmacological value of EAEO in hepatocellular carcinoma (HCC) remains largely unexplored. Herein, we investigated the anti-HCC activities of EAEO, and explored the potential mechanisms of EAEO-induced apoptosis. An MTT assay showed that EAEO inhibited HCC cell proliferation with little toxicity on normal liver cells. Wound healing and FACS assays revealed that EAEO suppressed HCC cell migration and arrested cell cycle, respectively. Moreover, EAEO promoted in vitro HCC cell apoptosis, and EAEO treatment inhibited HepG2 xenografts growth and enhanced apoptotic nucleus of xenografts in HepG2-bearing nude mice. Mechanistically, EAEO significantly decreased the ratio of Bcl-2/Bax and resulted in the activation of caspase-9 and -3. EAEO also reduced the expression of Grp78, which in turn relieved the inhibition of caspase-12 and -7. Meanwhile, EAEO suppressed the phosphorylation of STAT3 and AKT, indicative of its anti-HCC potential. In summary, we determined that EAEO treatment promoted HCC apoptosis via activation of the apoptotic signaling pathway in mitochondria and endoplasmic reticulum, as well as repressed the activity of STAT3 and AKT in HCC cells

A New Triterpene from the Plant of Uncaria Macrophylla

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A New Triterpene From Uncaria macrophylla and Its Antitumor Activity

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Potential Molecular Mechanism of <i>Illicium simonsii</i> Maxim Petroleum Ether Fraction in the Treatment of Hepatocellular Carcinoma

Traditional Chinese medicine (TCM) has been considered, for many years, an important source of medicine to treat different diseases. As a type of TCM, Illicium simonsii Maxim (ISM) is used as an anti-inflammatory, anti-bacterial, and anti-virus. Besides, ISM is also used in the treatment of cancer. In order to evaluate the anti-hepatocellular carcinoma (HCC) activity, petroleum ether extract was prepared from part of the fruit of ISM. First, the compounds of the petroleum ether fraction of Illicium simonsii Maxim (PEIM) were identified using LC-MS/MS analysis. Next, the cell viability and morphological changes were evaluated by MTT assay and Hoechst staining. In addition, the effect of PEIM on the levels of inflammatory factors (TNF-α, IL-1β, and IL-6) was determined using the ELISA kit. Furthermore, apoptosis was evaluated by flow cytometry, and gene expression and the regulation of signaling pathways were investigated, respectively, by real-time fluorescence quantitative PCR (RT-qPCR) and western blot. Results showed that a total of 64 compounds were identified in the PEIM. Additionally, the PEIM had anti-HCC activity against HepG2 cells, in which the half maximal inhibitory concentration (IC50) was 55.03 μg·mL−1. As well, the PEIM was able to modulate the expression of TNF-α, IL-1β, and IL-6, while we also found that it induced HepG2 cell apoptosis through the activation of P53 mRNA and caspase-3 mRNA. Finally, the PEIM possibly downregulated the expression of TLR4, MyD88, p-NF-κBp65, TNF-α, IL-1β, INOS, IL-6, JAK2, STAT3, CyclinD1, CDK4, MDM2, and Bcl-2, and upregulated the expression of P53, P21, Bax, Cytochrome-C, Caspase-9, and Caspase-3 in HepG2 cells. These findings may confirm that the PEIM has possible anti-HCC effects. However, additional studies are required to fully understand the mechanisms of action of the PEIM and the signaling pathways involved in its effects. Moreover, the anti-HCC activity of the PEIM should be studied in vivo, and signaling pathways involved in its effects should be explored to develop the anti-HCC drug

Three New Phenolics and Other Constituents from the Seeds of Lithocarpus pachylepis

Twelve phenolics, including the three new compounds balanophonin C (1), balanophonin D (2), balanophonin E (3), were isolated from the seeds of Lithocarpus pachylepis. Their structures were elucidated by various spectroscopic techniques (UV, IR, MS, 1D and 2D NMR). Compounds 1–9 were evaluated for their anti-inflammatory activities on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 and showed moderate inhibitory activities, with IC50 values ranging from 10.9 to 34.7 μM