Epitaxial substitution of metal iodides for low-temperature growth of two-dimensional metal chalcogenides.

The integration of various two-dimensional (2D) materials on wafers enables a more-than-Moore approach for enriching the functionalities of devices1-3. On the other hand, the additive growth of 2D materials to form heterostructures allows construction of materials with unconventional properties. Both may be achieved by materials transfer, but often suffer from mechanical damage or chemical contamination during the transfer. The direct growth of high-quality 2D materials generally requires high temperatures, hampering the additive growth or monolithic incorporation of different 2D materials. Here we report a general approach of growing crystalline 2D layers and their heterostructures at a temperature below 400 °C. Metal iodide (MI, where M = In, Cd, Cu, Co, Fe, Pb, Sn and Bi) layers are epitaxially grown on mica, MoS2 or WS2 at a low temperature, and the subsequent low-barrier-energy substitution of iodine with chalcogens enables the conversion to at least 17 different 2D crystalline metal chalcogenides. As an example, the 2D In2S3 grown on MoS2 at 280 °C exhibits high photoresponsivity comparable with that of the materials grown by conventional high-temperature vapour deposition (~700-1,000 °C). Multiple 2D materials have also been sequentially grown on the same wafer, showing a promising solution for the monolithic integration of different high-quality 2D materials.

Sedative and hypnotic effects of Perilla frutescens essential oil through GABAergic system pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Chinese medicine believes that depression syndrome has become one of the core pathogenesis of insomnia. The pharmacology of traditional Chinese medicine points out that Perilla frutescens has the effect of regulating Qi and relieving depression, promoting Qi circulation to relieve pain, so Perilla frutescens may have the potential therapeutic effect on insomnia. Related studies have reported the sedative and hypnotic effects of Perilla frutescens, but these studies have not yet explored the mechanism of sedative and hypnotic effects of Perilla frutescens essential oil (PFEO) through inhalation administration. AIM OF THE STUDY: The purpose of this study is to explore the underlying sedative and hypnotic mechanisms of PFEO through the GABAergic system pathways. MATERIALS AND METHODS: Established the PCPA insomnia model of mice, The open field test, pentobarbital-induced falling asleep rate, latency of sleeping time, and duration of sleeping time experiments were used to evaluate the behavior of mice, the enzyme-linked immunosorbent assay was used to analyze the content of 5-HT and GABA in hypothalamus and cerebral cortex. Immunohistochemical experiment, Western blot experiment and RT-PCR experiment were used to study the mechanism of PFEO through GABAergic pathway to regulate insomnia. The main volatile constituents of PFEO were analyzed by gas chromatography-mass spectrometry (GC-MS). RESULTS: The inhalation of PFEO has sedative and hypnotic effects, which reduce significantly the autonomic activity of PCPA insomnia mice, increase falling asleep rate, shorten latency of sleeping time, and prolong duration of sleeping time; the results of enzyme-linked immunosorbent assay show that PFEO increase the content of 5-HT and GABA in hypothalamus and cerebral cortex. The results showed that inhalation of PFEO increase the expression of GABAAα1 and GABAAα2 positive cells, increase the level of GABAAα1 and GABAAα2 protein and also increase the level of GABAAα1 mRNA and GABAAα2 mRNA in the hypothalamus and cerebral cortex. The highest content of PFEO is Perillaldehyde (54.37%), followed by 1,4-Cineole (7.42%), Acetaldehyde diethyl acetal (6.61%), D-Limonene (5.09%), Eucalyptol (4.94%), etc. CONCLUSION: The inhalation of PFEO has sedative and hypnotic effects, it is speculated that the mechanism of which may be the sedative and hypnotic effects through the GABAergic pathway.

[Effect of Sijunzi Decoction on regulation of Aß-related proteins across blood-brain barrier].

According to traditional Chinese medicine, "spleen transport" is closely related to the metabolism of substance and energy. Studies have shown that Alzheimer's disease(AD) is a disease related to glucose and lipid metabolism and energy metabolism. The traditional Chinese medicine Jiangpi Recipe can improve the learning ability and memory of AD animal model. Sijunzi Decoction originated from Taiping Huimin Hefang Prescription is the basic prescription for strengthening and nourishing the spleen, with the effects of nourishing Qi and strengthening the spleen. In this experiment, human brain microvascular endothelial cells(HBMEC) and Sijunzi Decoction water extract(0.25, 0.5, 1 mg·L~(-1)) were pre-incubated for 2 h, and then Aß_(25-35) oligomers(final concentration 40 µmol·L~(-1)) was added for co-culture for 22 hours. The effect of Sijunzi Decoction on the activity of Aß_(25-35) oligomer injured cells and the expression of related proteins were investigated. Q-TOF-LC-MS was used first for principal component analysis of Sijunzi Decoction water extract. Then MTT assay was used to investigate the effect of Sijunzi Decoction water extract on the proliferation of HBMEC cells. Real-time fluorescence quantitative PCR(RT-qPCR) was employed to detect the mRNA expression of GLUT1, RAGE, and LRP1. The expression of Aß-related proteins across blood-brain barrier(RAGE, LRP1) was detected by Western blot. The results showed that 40 µmol·L~(-1) Aß_(25-35) oligomers could induce endothelial cell damage, reduce cell survival, increase expression of RAGE mRNA and RAGE protein, and reduce expression of GLUT1 mRNA, LRP1 mRNA, and LRP1 protein. Sijunzi Decoction water extract could reduce the Aß_(25-35) oligomer-induced cytotoxicity of HBMEC, decrease the expression of RAGE mRNA and RAGE protein, and increase the expression of GLUT1 mRNA, LRP1 mRNA and LRP1 protein. The results indicated that Sijunzi Decoction could reduce the injury of HBMEC cells induced by Aß_(25-35) oligomer, and regulate the transport-related proteins GLUT1, RAGE and LRP1, which might be the mechanism of regulating Aß_(25-35) transport across the blood-brain barrier.

Effect of Zhenxin Xingshui Yizhi Fang on Aß25-35 induced expression of related transporters in HBMEC cell model.

ETHNOPHARMACOLOGICAL RELEVANCE: Aß (ß-amyloid) deposition and abnormal transport were suggested to be risk factors for Alzheimer's disease (AD). Zhenxin Xingshui Yizhi Fang (XSF), an ancient prescription in traditional Chinese medicine, was first recorded in Qianjin Yifang for treating palpitation, hypnosia, amnesia. It is reported that XSF could improve mice learning memory ability, reduce the deposition of senile plaques in hippocampus of rat brain. In this study, the neuroprotective effect of XSF against Aß25-35-induced apoptosis in cultured human brain microvascular endothelial cells (HBMEC) and its potential mechanism were investigated. MATERIALS AND METHODS: HBMEC cells were treated with Aß25-35 to established neurotoxic cell model. After that, the cells were treated with 125, 250, 500 µg/mL XSF to observe the protective effect. The viability of HBMEC cells were evaluated by MTT assay, the Aß25-35-induced apoptosis was characterized by Hoechst-33258 and the activity of cysteinyl aspartate specific proteinase-3. The expression level of Aß1-42 in cells induced by Aß25-35 was measured by human Aß1-42 kit. Protein and mRNA expression levels of advanced glycation end products (RAGE), low density lipoprotein receptor-related protein 1 (LRP1), glucose transporter 1 and 3 (GLUT1 and GLUT3) were assayed by capillary electrophoresis immunoassay and quantitative real-time polymerase chain reaction analyses. RESULTS: In Aß25-35 induced neurotoxic cells, the percentage of apoptotic cells, the concentration of Aß1-42 and CASPASE-3 activity, protein and mRNA expression levels of RAGE increased significantly, but that of LRP1, GLUT1 and GLUT3 significantly decreased. XSF could inhibit the apoptotic of cells, reduced the concentration of Aß1-42 and CASPASE-3 expression, downregulate RAGE and upregulate LRP1, GLUT1 and GLUT3 expression. CONCLUSION: The results suggest that XSF can reduce the cytotoxicity of HBMEC induced by Aß25-35, inhibit apoptosis, and regulate the transport of Aß on BBB and energy metabolism disorder in HBMEC.

Sedative and hypnotic effects of compound Anshen essential oil inhalation for insomnia.

BACKGROUNDS: The chemical composition of many essential oils indicates that they have sedative and hypnotic effects, but there is still a lack of systematic studies on the sedative and hypnotic effects of essential oils. In addition, aromatherapy does not seem to have the side effects of many traditional psychotropic substances, which is clearly worthwhile for further clinical and scientific research. The clinical application of essential oils in aromatherapy has received increasing attention, and detailed studies on the pharmacological activities of inhaled essential oils are increasingly needed. HYPOTHESIS/PURPOSE: As insomniacs are usually accompanied by symptoms of depression and anxiety of varying degrees, based on the theory of aromatherapy of Traditional Chinese Medicine, this experiment is to study a Compound Anshen essential oil that is compatible with Lavender essential oil, Sweet Orange essential oil, Sandalwood essential oil and other aromatic medicine essential oils with sedative and hypnotic effects, anti-anxiety and anti-depression effects. To study the sedative and hypnotic effects of Compound Anshen essential oil inhaled and the main chemical components of Compound Anshen essential oil, and to compare and analyze the pharmacodynamics of diazepam, a commonly used drug for insomnia. METHODS: The Open field test and Pentobarbital-induced sleep latency and sleep time experiments were used to analyze and compare the sedative and hypnotic effects of inhaling Compound Anshen essential oil and the administration of diazepam on mice. The changes of 5-HT and GABA in mouse brain were analyzed by Elisa. The main volatile constituents of Compound Anshen essential oil were analyzed by gas chromatography-mass spectrometry (GC-MS). RESULTS: Inhalation of Compound Anshen essential oil can significantly reduce the spontaneous activity of mice, reduce latency of sleeping time and prolong duration of sleeping time. The results of enzyme-linked immunosorbent assay showed that Compound Anshen essential oil can increase the content of 5-HT and GABA in mouse brain. The main volatile chemical constituents of the Compound Anshen essential oil are D-limonene (24.07%), Linalool (21.98%), Linalyl acetate (15.37%), α-Pinene (5.39%), and α-Santalol (4.8%). CONCLUSION: The study found that the inhalation of Compound Anshen essential oil has sedative and hypnotic effect. This study provides a theoretical basis for further research and development of the sedative and hypnotic effects of Compound Anshen essential oil based on the theory of aromatherapy.