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By suppressing the growth of impurities, a melt spinning method was successfully applied to the synthesis of typical 1 : 2 : 2 layered CeMn 2 Si 2 and AlFe 2 B 2 compounds. X-ray diffraction analysis showed that CeMn 2 Si 2 and AlFe 2 B 2 had good purity and crystallized in ThCr 2 Si 2 -and AlFe 2 B 2 -type structures, respectively. The differences among three 1 : 2 : 2-type structures were also analyzed. The magnetic properties were investigated by magnetic measurements and electronic structure calculations. It was found that the Fe moment of AlFe 2 B 2 reaches 1.32 μ B at 5 K, which fits well with the calculated result of 1.44 μ B at 0 K, and that the isothermal magnetic entropy change reaches 7.2 J kg %1 K %1 at 5 T, which shows great potential for room-temperature refrigeration applications.

Abstract. Signal transducer and activator of transcription 1 (STAT1) regulates cell proliferation and survival. The present study aimed to investigate the role of STAT1 in the development and progression of human hepatocellular carcinoma (HCC). The levels of STAT1 expression in 36 HCC and 12 non-HCC liver tissues were examined by immunohistochemistry. The effect of STAT1 overexpression or silencing on the proliferation and apoptosis of HCC cells was determined by MTT and flow cytometric assays. The effect of STAT1 overexpression or silencing on the levels of p53 and cyclin E expression was determined by quantitative PCR and western blot assays. The level of STAT1 expression in the HCC tissues was significantly lower compared to the level in the non-HCC liver tissues and was negatively associated with the histological grade of HCC and serum HBsAg, anti-HCV and α-fetoprotein positivity in HCC patients. Induction of STAT1 overexpression significantly inhibited HepG2 cell proliferation and enhanced HCC cell apoptosis, accompanied by upregulation of p53 expression and STAT1 phosphorylation, but a reduction in cyclin E expression in HepG2 cells. In contrast, knockdown of STAT1 by introduction of STAT1-specific siRNA promoted HepG2 cell proliferation, but inhibited HCC cell apoptosis, accompanied by significant downregulation of p53 expression, but enhancement of cyclin E expression in vitro. Our data suggest that STAT1 may inhibit HCC growth by regulating p53-related cell cycling and apoptosis.

Huperzine Q (1) and N-oxyhuperzine Q (2), two novel irregular fawcettimine-type Lycopodium alkaloids were isolated from the CHCl 3 fraction of the basic material of the whole plant of the Chinese medicinal herb Huperzia serrata. Their structures were determined as 13-epi-13b,16-epoxydihydrofawcettimine (1) and N-oxy-13-epi-13b,16-epoxydihydrofawcettimine (2) by means of spectroscopic studies and X-ray crystallographic analysis.Introduction. ± Huperzia serrata (Thunb.) Trev. (Huperziaceae) is one of the most commonly used traditional Chinese herbal medicines for the treatment of contusion, strain, swelling, and schirophrema [1]. The discovery that huperzine A, a Lycopodium alkaloid isolated from this plant, was a potent acetylcholinesterase inhibitor [2] has prompted us reinvestigate the chemical constituents of this plant. As a continuation of our work [3], we re-examined the CHCl 3 extract of the basic materials of dry whole plants (10 kg), and obtained huperzine Q (1) and N-oxyhuperzine Q (2), two novel compounds that represent a unique structural type among the Lycopodium alkaloids [4]. In the present paper, we report the isolation and structural elucidation of the above compounds.

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Spinal cord injury (SCI) is a severe health problem and the mechanism involved remains elusive. The aim of the present study was to elucidate the role of C/EBP homologous protein (CHOP), a prominent protein of the endoplasmic reticulum (ER) stress-mediated apoptosis in SCI. A total of 20 adult male Sprague-Dawley rats were divided into two groups at random, ten rats were subjected to a modified Allen’s test (using a weight-drop device) to induce a SCI model and the remaining ten rats only had the corresponding vertebral lamina removed with no injury and served as the sham-operated group. Pathological changes in the spinal cord were observed 12 h after injury by hematoxylin and eosin staining and TUNEL staining was performed to visualize apoptotic cells. The expression of CHOP was also detected by immunohistochemistry and quantitative real-time reverse transcription-polymerase chain reaction. The results showed that a typical apoptotic morphology, namely the increased the number of TUNEL-positive cells in the injured spinal cord. The expression levels of CHOP in the rats with SCI were increased compared with the sham-operated rats (P<0.05). These results revealed that CHOP-mediated ER stress-induced apoptosis may be involved in SCI.