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Meteorites are an essential reference for human exploration of the universe and its cosmic evolution and an essential research object for searching for extraterrestrial life. Ways to quickly identify and screen suspected meteorite samples have become the foundation and prerequisite for research on high-value meteorite samples. Therefore, this paper proposes a Raman mapping-assisted micro-laser induced breakdown spectroscopy (micro-LIBS) technology for field detection of suspected meteorite material composition without sample pre-processing, with a high detection speed and cost-effectiveness, to realize the detection of element composition and molecular structure. Raman mapping carries out multispectral imaging with high spectral resolution of the region of interest. The fusion of Raman mapping and optical microscopy images can provide mineral categories and spatial distribution characteristics in regions of interest. A quantitative analysis model for Fe, Mg, and Na elements was constructed based on the multidimensional scaling–back propagation neural network (MDS-BPNN) algorithm. The determination coefficient of the model test set was better than 0.997, and the root mean square error was better than 0.65. The content of Fe, Mg, and Na elements in the meteorite was preliminarily evaluated, providing a reference for further analysis of element information in spectral image fusion data. The Raman–LIBS combined technology has significant application potential in rapidly evaluating suspected meteorite samples. Without high-end precision instruments or field research, this technology can provide scientists with significant reference value atomic and molecular spectral information. At the same time, this technology can be extended to other petrology research. We offer a fast, efficient, cost-effective, and reliable analysis scheme for reference. [ABSTRACT FROM AUTHOR]

The stream sediment (SS) records evolution information of the water system structure and sedimentary environment in specific regions during different geological periods, which is of great significance for studying the ancient planetary environment and the law of water system changes. Based on the SS of different geographical environments on Earth, remote laser-induced breakdown spectroscopy (remote-LIBS) technology combined with the multidimensional scaling-back propagation neural network (MDS-BPNN) algorithm was used to conduct an in-depth analysis of remote qualitative and quantitative detection of the elemental composition and content of SS. The results show that the detection system based on remote LIBS combined with an artificial neural network algorithm can achieve an ideal quantitative analysis of major and trace elements. The coefficients of determination (R2) of the test set for major elements is greater than 0.9996, and the root mean square error (RMSE) is less than 0.7325. The coefficients of determination (R2) of the test set for trace elements is greater than 0.9837, and the root mean square error is less than 42.21. In addition, for the application scenario of exploring extraterrestrial life, biominerals represented by stromatolite phosphorite (SP) are easy to form sand and enter into SS under weathering. Therefore, this paper discusses the feasibility of using remote-LIBS technology to detect and identify such minerals under the disappearance of SPs' macro- and micro-characteristics. From our research, we can find that remote-LIBS technology is the preferred candidate for discovering dust-covered biominerals. In geological environments rich in water system sedimentary rocks, such as Mars' ancient riverbeds, LIBS technology is crucial for deciphering the "life signals" hidden in the Martian sand. [ABSTRACT FROM AUTHOR]

Objective To prepare lentiviruses expressing shRNA sequences targeting human signal transducer and activator of transcription 3 (STAT3) and detect the effect of STAT3 knockdown on type I interferon (IFN1)-induced proliferation and migration in HepG2 cells. Methods Four STAT3-targeting shRNA sequences (shRNA1-shRNA4) and one control sequence (Ctrl shRNA) were selected and cloned respectively into pLKO.1-sp6-pgk-GFP to construct shRNA-expressing vectors. Along with backbone psPAX2 and pMD2.G vectors, they were separately transfected into HEK293T cells to prepare lentiviruses. HepG2 cells were infected with the lentiviruses. Cytoplastic STAT3 level was detected by Western blotting to screen effective shRNA sequence(s) targeting STAT3. Proliferation and migration of HepG2 cells were analyzed by CCK-8 assay and Transwell TM migration and scratching assay, respectively. To detect the effect of IFN1 on cell proliferation and migration of HepG2 cells, the cells were treated with 2000 U/mL IFNα2b for indicated time and the activation of IFN-triggered STAT1 signal transduction was assayed by Western blotting. Results Two most effective STAT3-targeting shRNA sequences shRNA1 and shRNA2 were selected, and the expression of both STAT3 shRNA significantly decreased proliferation and migration of HepG2 cells. When treated with IFNα2b, 2000 U/mL of IFN1 showed more competent in attenuating growth and migration of HepG2 cells. Our data further proved that knockdown of STAT3 increased the phosphorylation of STAT1, and IFNα2b further enhanced the activation of STAT1 signaling in HepG2 cells. Conclusion Knockdown of STAT3 inhibits cell migration and growth, and rescues IFN response through up-regulating STAT1 signal transduction in HepG2 hepatoma cells.