(2Z,2′Z,4E,4′E)-4,4′-(Cyclo­hexane-1,2-diyldinitrilo)dipent-2-en-2-ol

A new tetra­dentate chiral Schiff base ligand, C16H26N2O2, has been synthesized by the reaction of acetyl­acetone with (1R,2R)-(−)-1,2-diamino­cyclo­hexane. Both of the mol­ecules in the asymmetric unit are of the same chirality (R configuration), since the absolute configuration was determined by the starting reagent (1R,2R)-(−)-1,2-diamino­cyclo­hexane. The six-membered cyclo­hexane ring is in a chair conformation, and the substituents are equatorial in the most stable conformation (trans-cyclo­hexyl). At the ring substituents, large conjugated —C=N—CH=C—OH systems exist, resulting from the original ketone converted into the enol form. With H atoms excluded, the atoms of each substituent lie in the same plane. The two mol­ecules in the asymmetric unit have almost the same structure, with slight differences in the torsion angles between the substituents and the cyclo­hexane ring; the corresponding N1—(C—C—C)cyclo­hexa­ne torsion angles are −177.2 (3) and 179.3 (4)° in one mol­ecule and −176.5 (3) and 178.4 (4)° in the other. Two intra­molecular O—H⋯N hydrogen bonds exist in each mol­ecule

Modification of slope stability probability classification and its application to rock slopes in hydropower engineering regions

Stability assessment of rock slopes in hydropower engineering regions is an important and complex issue. Rock mass classification systems are a good approach because they thoroughly consider many factors influencing rock slope stability. The slope stability probability classification (SSPC) system is a novel method. However, it has two obvious limitations when applied to rock slopes: 1) it is only suitable for slopes less than 45 m in height, and 2) there is great subjectivity and randomness in the estimation of intact rock strength. Therefore, this study presents two modifications of the SSPC system by adopting the Hoek–Brown strength criterion and an empirical formula for maximum slope height. Evaluation of results from of 34 typical rock slopes of the major hydropower engineering regions in China indicated that the accuracy rate of the modified SSPC for stability evaluation of these slopes was 61.8%, and the accuracy for stability evaluation of 10 slopes with non-structural control failure was 80%. The stability values of stable and unstable slopes obtained using the modified SSPC were different to those obtained using the Chinese Slope Mass Rating (CSMR) and modified CSMR systems. In addition, the identification accuracy rate of the modified SSPC was significantly higher than that of the CSMR and modified CSMR. Therefore, the modified SSPC can be applied to hydropower engineering regions, providing a new means of rapidly evaluating the slope stability of high rock slopes (slopes > 45 m in height) in these regions.</p

Luteoloside Inhibits Proliferation of Human Chronic Myeloid Leukemia K562 Cells by Inducing G2/M Phase Cell Cycle Arrest and Apoptosis

Purpose: To investigate the effects of luteoloside on the proliferation of human chronic myeloid leukemia K562 cells and whether luteoloside induces cell cycle arrest and apoptosis in K562 cells.Methods: Luteoloside’s cytotoxicity was assessed using a cell counting kit. Cell cycle distribution was analysed by flow cytometry after propidium iodide (PI) staining. Cell apoptosis was assayed with apoptosis detection kit and Hoechst staining followed by observation under a fluorescence microscope. The expression of cell cycle- and apoptosis-related proteins was examined by Western blot analysis.Results: Luteoloside inhibited the proliferation of K562 cells in a dose- and time- dependent manner (IC50 = 30.7 μM) with less toxicity in a normal human cell line (IC50 = 91.8 μM). Moreover, antiproliferative effect of luteoloside was accompanied with G2/M phase arrest（p ＜ 0.05 or p＜0.01） and apoptosis（p ＜ 0.01 or p ＜ 0.001）. Further studies revealed that the expression level of cyclinB1 was down-regulated by luteoloside treatment. Furthermore, luteoloside treatment also increased proapoptotic protein Bax expression and decreased anti-apoptotic protein Bcl-2 expression.Conclusion: These results suggest that the inhibitory effect of luteoloside on K562 cell proliferation is associated with inducing G2/M phase arrest and apoptosis, and that luteoloside is worth further studying for anticancer potential.Keywords: Luteoloside, Myeloid leukemia, Proliferation, Cell cycle arrest, Apoptosis, Anticance

Theoretical calculation of the ‘natural flock restoration’ time of a cotton comber

Based on the overhanging beam theory, the stress on the flock of a cotton comber has been analyzed, and the natural frequency of the ‘natural flock restoration’ is calculated in combination with energy method. Finally, a theoretical model of the ‘natural flock restoration’ time has been developed. The model illustrates that the ‘natural flock restoration’ time of a cotton comber is determined by cotton properties, combing process and mechanical structure. The established theoretical model corrects the previous calculation method for the ‘natural flock restoration’ time of a cotton comber. The finding provides information for the development of a new type of cotton comber with high velocity

2-Carb­oxy-1-phenyl­ethanaminium perchlorate

In the title compound, C9H12NO2 +·ClO4 −, an intra­molecular N—H⋯O inter­action results in the formation of a six-membered ring having a twisted chair conformation. In the crystal structure, inter­molecular O—H⋯O, N—H⋯O and C—H⋯O inter­actions link the mol­ecules into a network. A weak C—H⋯π inter­action is also found

The Study of Dynamic Monitor of Rice Drought in Jiangxi Province with Remote Sensing

AbstractMODIS sensor has a high temporal resolution, spectral resolution, and moderate spatial resolution. The data products are widely used in Large-scale and long period dynamic monitoring of drought. This paper focuses on characters of farming rice dominated in Jiangxi province, and analysis on remote sensing monitoring model and drought monitoring indicators which selection the MODIS data products and drought information related from 2000-2008. Established standard for classification of drought in Jiangxi province, and verified instances of 2003 drought in Jiangxi. This study may have a certain significance to agricultural drought monitoring based on rice planting in southern China, because the correspondencematch between the selected TD indices and cloud cover with precipitation and daily maximum temperature evolution curve

Quality evaluation of cortex berberidis from different geographical origins by simultaneous high performance liquid chromatography combined with statistical methods

Purpose: To develop an effective method for evaluating the quality of Cortex berberidis from different geographical origins.Methods: A simple, precise and accurate high performance liquid chromatography (HPLC) method was first developed for simultaneous quantification of four active alkaloids (magnoflorine, jatrorrhizine, palmatine, and berberine) in Cortex berberidis obtained from Qinghai, Tibet and Sichuan Provinces of China. Method validation was performed in terms of precision, repeatability, stability, accuracy, and linearity. Besides, partial least squares discriminant analysis (PLS-DA) and one-way analysis of variance (ANOVA) were applied to study the quality variations of Cortex berberidis from various geographical origins.Results: The proposed HPLC method showed good linearity, precision, repeatability, and accuracy. The four alkaloids were detected in all samples of Cortex berberidis. Among them, magnoflorine (36.46 - 87.30 mg/g) consistently showed the highest amounts in all the samples, followed by berberine (16.00 - 37.50 mg/g). The content varied in the range of 0.66 - 4.57 mg/g for palmatine and 1.53 - 16.26 mg/g for jatrorrhizine, respectively. The total content of the four alkaloids ranged from 67.62 to 114.79 mg/g. Moreover, the results obtained by the PLS-DA and ANOVA showed that magnoflorine level and the total content of these four alkaloids in Qinghai and Tibet samples were significantly higher (p &lt; 0.01) than those in Sichuan samples.Conclusion: Quantification of multi-ingredients by HPLC combined with statistical methods provide an effective approach for achieving origin discrimination and quality evaluation of Cortex berberidis. The quality of Cortex berberidis closely correlates to the geographical origin of the samples, with Cortex berberidis samples from Qinghai and Tibet exhibiting superior qualities to those from Sichuan.Keywords: Tibetan medicine, Cortex berberidis, Origin discrimination, Quality evaluation, Magnoflorine, Palmatine, Berberine, Jatrorrhizin