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Artificial active matters on a macroscopic scale, including vibrating particles, robots, and camphor boats, have attracted increasing attentions due to their uniform properties, rich and easily controllable parameters, convenient observation, and the independence of biochemical processes from physical processes, especially providing these unique advantages for researching the collective behaviors under strong confinement and crowded surroundings. In this review, we present an overview of motion models, mechanisms, and dynamic characteristics of various active particles, both in free and complex media. Additionally, we delve into the collective behaviors of "dry'' active matter, covering structural and dynamic properties observed in experiments and theoretical models. We summarize the impact of hydrodynamic interactions on the dynamics and structures of these active particles within hydrodynamic environments. Lastly, we discuss emerging opportunities and challenges for future advancement of macroscopic artificial active matter.

A simple one-step hydrothermal method to synthesize interlayer-expanded molybdenum disulfide microflowers (E-MoS2) by increasing the proportion of thiourea in the reactant was proposed. In the method, ammonium thiocyanate, the product of thiourea conversion in hydrothermal reaction, is embedded into the interlayer of MoS2 formed in situ to expand the layer spacing, which avoids the complex synthesis process of traditional E-MoS2 and the introduction of foreign species and templates. The E-MoS2 reveals a small Tafel slope of 68.5 mV/dec and a low overpotential of 285 mV at -10 mA/cm2, markedly lower than those of initial MoS2 counterpart (122.2 mV/dec and 588 mV, respectively), indicating its excellent hydrogen evolution performance. Compared with the original MoS2, the enhanced hydrogen evolution performance of E-MoS2 can be attributed to the following reasons: the expansion of interlayer spacing optimizes the electronic structure of MoS2, thereby improving its conductivity and reducing the hydrogen adsorption free energy; the in situ intercalation of ammonium thiocyanate inhibits the growth and reduces the size of microflowers during the synthesis process, thus exposing more active sites for E-MoS2. Therefore, the E-MoS2 is expected to be a promising non-noble metal electrocatalyst for hydrogen evolution reaction.

An anion-cation co-doping strategy was proposed, and the Mn and P co-doped MoS2 microflowers (Mn, P)-MoS2 catalyst were prepared successfully by one-step hydrothermal reaction for hydrogen evolution reaction(HER). The structure, morphology, chemical composition and valence state were characterized by X-ray diffraction, Raman spectra, scanning electron microscope, X-ray photoelectron spectroscopy and energy dispersive spectroscopy, and the HER performance was performed by electrochemical workstation for (Mn, P)-MoS2. The results show that Mn and P atoms are successfully incorporated into the MoS2 lattice, and the hydrogen evolution overpotential of (Mn, P)-MoS2 at a current density of 10 mA·cm-2 is 235 mV and a small Tafel slope of 61.2 mV·dec-1, which are lower than those of the pure MoS2 and Mn-cation or P-anion doped MoS2. Meanwhile, (Mn, P)-MoS2 presents excellent HER stability. The excellent HER performance of (Mn, P)-MoS2 could be attributed to: the incorporation of Mn and P activates the inert basal plane, optimizes the electronic structure and increases the conductivity of MoS2. The synergistic interaction between Mn and P realizes the complementary advantage of single anion or cation doping, and it increases the number of active sites at basal plane for hydrogen evolution, thus speeding up the Volmer electrochemical desorption step.

BACKGROUND The emerald is loved by people because of its gorgeous color and is respected as one of the world's four major gems. Due to the high value of emeralds, a variety of synthesis and optimization methods have emerged. The hydrothermal method is one of the common methods to produce synthetic emeralds. The emeralds synthesized by this method have typical water ripple texture, showing a serrated parallel arrangement, and the characteristic peaks of the infrared absorption spectrum in the range of 2300-3100cm-1 are the main identification feature. However, some emeralds synthesized by this method do not have the above typical characteristics. This has brought a great challenge to the quality inspection agencies, and brought many doubts to the majority of consumers, and affected the stability of the gem market. OBJECTIVES It is essential to study the new emerald synthesized by this new hydrothermal method. The refractive index, density, polychromatism, and infrared absorption spectrum characteristics of the tested samples are very similar to those of natural emeralds, so infrared absorption spectrum analysis cannot obtain the supporting evidence of its cause. Based on this, the gemological and spectral characteristics of the test samples were studied by ultraviolet visible spectrum, energy dispersive X-ray fluorescence spectrometry (EDXRF) and other spectroscopic means. Finally, the test samples were determined to be a new kind of emerald synthesized by the hydrothermal method. METHODS The refractive index, birefringence, relative density, polychromaticity and weight of the samples were tested by refractometer, electronic balance, and dichroic mirror. The internal and external characteristics of the test samples, the cutting and polishing quality of the samples, and the characteristics of internal inclusions were observed by gem microscope. The infrared reflection spectrum and infrared transmission spectrum characteristics of the samples were analyzed by Fourier transform infrared spectrometer and compared with the infrared spectrum characteristics of emeralds from different origins. The absorption spectrum characteristics of the samples were analyzed by ultraviolet-visible spectrometer, focusing on the absorption peak characteristics near 830nm. The element characteristics of the samples were tested by EDXRF, because the content characteristics of Cr and Ni in emerald are the key to identify whether it is natural or not. RESULTS The mass of the tested samples was 0.17-0.56g, the refractive index was 1.571-1.588, the birefringence was 0.007-0.009, the relative density was 2.56-2.78, and the polychromaticity was obviously blue-green/green. These conventional gemological characteristics were consistent with natural emeralds. The samples were observed under a gemstone microscope, and the samples had a parallel texture of suspected water ripple, but not typical. The water ripple texture of the typical hydrothermal synthetic emeralds was serrated parallel arrangement. However, the characteristics under the gem microscope should arouse the suspicion of jewelry inspectors.The infrared reflectance spectra of the samples had characteristic peaks of 1242, 1219, 1022, 968, 810, 741, 687, 594, 528, 490, and 459cm-1. The characteristic peaks of 1242, 1219, 1022, 968, 810, 741, and 687cm-1 were caused by the stretching vibration of Si—O—Si and O—Si—O, and the characteristic peaks of 594, 528, 490, and 459cm-1 were caused by the bending vibration of Si—O and the vibration of M—O. The infrared reflection spectrum characteristics of the samples were consistent with the infrared spectrum characteristics of beryl, but the infrared spectrum characteristics of the fingerprint area could not indicate whether the samples were natural or synthetic.The infrared transmission spectra of the samples had 5445, 5273, 5109, 4874, 4800, 4650, 4547, 3321, 3222, 3027, 2953, 2928, and 2431cm-1 characteristic peaks. 5273cm-1 was caused by typeⅡ water absorption, 5445cm-1 and 5109cm-1 were caused by typeⅠ water absorption. The typeⅡ water absorption peak of the test samples was relatively sharp at 5273cm-1, and the typeⅠ water absorption peaks at 5445cm-1 and 5109cm-1 were relatively strong. Compared with previous studies, the shape and intensity of water absorption peaks of natural emerald and hydrothermally synthesized emerald were different. The infrared absorption spectrum characteristics of the water of the test sample were different from those of natural emerald, but the diagnostic direct evidence could not be obtained from the infrared absorption spectrum. The infrared peak in the range of 2300-3100cm-1 is caused by Cl- ion absorption. According to the results of previous studies, the absorption intensity of hydrothermal synthetic emeralds in this wavenumber range was significantly stronger than that of natural emeralds. The infrared absorption spectra of the test samples were relatively weak in the range of 2300-3100cm-1, which was more similar to the infrared absorption spectrum characteristics of natural emeralds in Colombia, Yunnan, Madagascar and Brazil, and was obviously different from the infrared absorption spectrum results of emeralds synthesized by the hydrothermal method. There were obvious differences between the infrared transmission absorption spectra of the traditional hydrothermal synthetic emeralds and natural emeralds. The characteristics of infrared absorption spectra are important evidence for identifying the genesis of emeralds. However, it is difficult to obtain the final accurate conclusion from the infrared absorption spectrum analysis of the test samples described in this paper, so they have been named 'new' type.The UV-Visible spectrum characteristics of the test samples showed that the absorption peak below 350nm was caused by the Fe2+-O2- charge transfer band in emerald, the absorption peak at 429nm was caused by Cr3+ ions, the broad absorption band at 550-650nm was mainly caused by Cr3+ ions, the absorption peak at 683nm was caused by Cr3+ ions, the sharp absorption peak at 956nm was caused by water absorption, and the broad absorption peak near 850nm should be caused by Fe2+ absorption, which was rarely seen in the previous hydrothermal synthesis of emerald. The combination of Cr3+ and Fe3+ replacing Al3+ makes emerald, green. The absorption peak of UV-Visible spectrum caused by Fe2+ in natural emerald was in the range of 810-850nm, and only a few of the absorption bands caused by Fe2+ in natural emeralds are not obvious. The absorption band of the UV-Visible spectra of the test samples was not obvious or weak in the range of 810-850nm, and the 850nm absorption peak of individual samples was obvious. Therefore, the emeralds examined by ultraviolet-visible spectroscopy may be synthetic, but this could not be conclusively confirmed.The EDXRF results showed that the samples had Fe, Ni and Cr elements, which was different from previous studies of natural emeralds. Yang Zhuo(2010) studies showed that the main trace elements in natural emeralds, from different origins such as Brazil, Colombia, Egypt, India, South Africa, Zimbabwe and Canada by LA-ICP-MS, were Fe, V, Cr, Mg, Na and Cs, but the content of Ni was very low, far lower than that of Cr. The content of Cr in Yunnan emeralds was 58-177μg/g, and Ni was not detected (Bai et al., 2019). The chemical element characteristics of gem-grade emeralds in Afghanistan, Brazil, Colombia, Ethiopia, Madagascar, Russia, Zambia and Zimbabwe showed that Ni element was not detected (Karampelas et al., 2019). The elemental composition of emeralds from South Africa, Afghanistan, Australia, Colombia, Egypt, Madagascar, Zambia, Zimbabwe, Tanzania and China was analyzed by electron probe microanalysis, and Ni was not detected (Lum et al., 2016). It could be seen that Cr and Fe elements coexisted in natural emeralds, but Ni was almost non-existent. EDXRF was used in this study without quantitative analysis but calibrated by the gold standard sample, and the relative peak intensity of the element was of great significance. The peak intensity of the Ni element in the test sample was much higher than that of the Cr element, which did not conform to the element content characteristics of the natural emerald, and was consistent with the high content of Ni in the hydrothermal synthesis of emerald reported by Lu and Shen (2021) and Yang et al.(2022). The comprehensive analysis showed that the test sample was a synthetic emerald. CONCLUSIONS The infrared absorption spectrum characteristics of the test samples are similar to those of natural emeralds, and the infrared absorption spectrum could not be used as a basis for identifying the genesis of emeralds. Previous studies show that a set of absorption peaks in the range of 2300-3100cm-1 in the infrared absorption spectrum is an important identification feature of the hydrothermal synthesis of emeralds, but this feature is not obvious in the tested samples. The UV-Visible spectrum of the sample shows that the absorption band near 810-850nm related to Fe2+ is not obvious. The X-ray fluorescence spectra of the samples show that the Kα peak intensity of Ni is much higher than that Kα of Cr, which is the main feature of the new emerald synthesized by the hydrothermal method. It could be seen from the experimental results that the identification of jewelry and jade is a systematic work. It is necessary to learn from the previous results and combine the comprehensive analysis of various detection methods to obtain the correct result.

The outcome of pancreatic adenocarcinoma (PAAD) patients is poor, given resistance to gemcitabine. Long noncoding RNA (lncRNA) has been implicated in the carcinogenesis of pancreatic cancer; however, its function and mechanism in PAAD resistance to gemcitabine (GEM) are yet unknown. Herein, we demonstrate that lncRNA DSCR9 is significantly reduced in PAAD in vitro and in vivo. CCK-8, BrdU and flow cytometry assays show that overexpression of DSCR9 markedly suppresses pancreatic cancer cell proliferation and invasion, and promotes apoptosis under gemcitabine treatment. BTG2 acts as a tumor suppressor by reducing the proliferation and invasion of pancreatic cancer cells and increasing gemcitabine-induced apoptosis. Immunofluorescence (IF) staining combined with fluorescence in situ hybridization (FISH) of pancreatic cancer tissues shows that DSCR9 and BTG2 are both increased in pancreatic cancer tissues. Luciferase assay shows that miR-21-5p simultaneously binds to DSCR9 and 3′UTR of BTG2; DSCR9 relieves miR-21-5p-induced inhibition of BTG2 by competing with BTG2 for miR-21-5p binding. Overexpression of miR-21-5p enhances the invasiveness of pancreatic cancer cells by promoting cancer cell proliferation and invasion and attenuating gemcitabine-induced apoptosis. Overexpression of miR-21-5p attenuates the effect of DSCR9 overexpression on BTG2 expression and invasiveness of pancreatic cancer cells. Finally, miR-21-5p expression is increased, while BTG2 expression is decreased in pancreatic cancer tissues. miR-21-5p is negatively correlated with DSCR9 and BTG2. In conclusion, the DSCR9/miR-21-5p/BTG2 axis modulates pancreatic cancer proliferation, invasion, and gemcitabine resistance.

A new method to synthesize phoxim.

In this paper, Ugi reaction was used to synthesize the modified polylysine (M-ε-PL) in two steps, and OD value was measured by ultraviolet spectrophotometer to determine the inhibitory rate of M-ε-PL in different concentrations of Escherichia coli and Staphylococcus aureus. The results showed that the antibacterial effect was better with the increase of concentration of M-ε-PL. Among them, 20 mg/mL M-εPL had better bacteriostatic effect on E. coli and S. aureus. The antibacterial rate was 70% and 44%.