Justification of Paris-type Fatigue Laws from Cohesive Forces Model via a Variational Approach

By using a principle of least energy and a surface energy of the Dugdale-Barenblatt type which is supplemented by an irreversibility condition, we build a debonding model of thin films valid for a monotone loadings as well as for cyclic loadings. When the internal length of the Dugdale model is small in comparison to the characteristic length of the film, we show that the growth of the debonding follows Griffith’s law under a monotone loading and a Paris-type law under a cyclic loading.     

Identification of chemical constituents in Rhizoma Paridis Saponins and their oral administration in rat plasma by UPLC/Q‐TOF/MS

On‐line ultra‐performance liquid chromatography (UPLC) coupled with diode‐array detection (UPLC/DAD) and electrospray ionization quadrupole time‐of‐flight mass spectrometry (ESI‐Q‐TOF‐MS) were used for separation, identification and structural analyses of saponins in Rhizoma Paridis saponins (RPS) and rat plasma after oral administration of RPS. Thirty steroidal saponins in RPS were identified by comparing their retention time, accurate mass measurement and positive and negative mass spectrometry data with that of reference compounds. The UPLC/Q‐TOF‐MS method was proved to be rapid and efficient in that 30 steroidal saponins, including three kinds of saponins (prototype, pennogenyl and diosgenyl saponins) were tentatively characterized within 6 min. After oral administration of RPS, 21 original saponins were absorbed in RPS‐treated rat plasma. Our results indicated that UPLC/Q‐TOF‐MS is a rapid and effective tool for identification of a series of saponins at trace level. Copyright © 2010 John Wiley & Sons, Ltd.     

Energy consumed by a bearing supported spindle in the presence of a dynamic cutting force and of defects

A machine tool spindle system model is proposed in this paper to investigate the non-linear face-milling cutting forces behavior, which are neglected in the literature, in order to predict the total mechanical power of a spindle. A simulation of the structure of the spindle based on the finite-element method is elaborated to estimate the variable cutting forces and then the variable power loss generated by bearings, considering the angular position and contact angles of the variable balls. Experiments are elaborated to compare the experimental power values with the predicted results. Particular attention is paid to different types of defects (inner ring spalling, outer ring spalling, eccentricity, and unbalance) in order to study their impact on the power consumed by the spindle during the approach and cutting phases under different rotating conditions.     

New Steroidal Saponins Isolated from the Rhizomes of Paris mairei

The genus Paris is an excellent source of steroidal saponins that exhibit various bioactivities. Paris mairei is a unique species and has been widely used as folk medicine in Southwest China for a long time. With the help of chemical methods and modern spectra analysis, five new steroidal saponins, pamaiosides A–E (1–5), along with five known steroidal saponins 6–10, were isolated from the rhizomes of Paris mairei. The cytotoxicity of all the new saponins was evaluated against human pancreatic adenocarcinoma PANC-1 and BxPC3 cell lines.     

FTIR、ATR-FTIR和UV多光谱鉴别不同产地重楼

测定了云南省及贵州省6个不同产地重楼的FTIR、ATR-FTIR及UV信息,并对ATR-FTIR光谱数据进行ATR校正(ATR-FTIR-A)、一阶导数(FD)、二阶导数(SD)、标准正态变量(SNV)等预处理,结合偏最小二乘判别分析(PLS-DA)与支持向量机(SVM)建立了单光谱与低级数据融合分类判别模型。结果表明,校正后的重楼ATR-FTIR(ATR-FTIR-A)光谱信息与KBr压片法展现的信息基本吻合; UV二阶导数图谱较原始图谱分辨率提高; ATR-FTIR-A单光谱及ATR-FTIR-A-UV低级数据融合的PLS-DA及SVM模型鉴别效果最好,预测正确率均达到100. 00%。基于ATR-FTIR-A建立的PLS-DA或SVM产地鉴别模型分类正确率高,在实际生产应用中有简便、高效、准确等优点,若采用ATR-FTIR-A-UV建立模型可进一步加强模型稳定性。     

Nuclear interactions of 200 GeV protons in emulsion

Proton-nucleus interactions have been studied in nuclear emulsion exposed to the NAL 200 GeV proton beam. The inelastic mean free path is found to be 35.5 ± 0.8 cm and the average shower particle multiplicity is 12.9 ± 0.2. The angular distribution reveals some characteristics features of proton-nucleus interactions.     

A novel phenylpropanoid glycosides and a new derivation of phenolic glycoside from Paris Polyphylla var. yunnanensis

A novel phenylpropanoid glycosides 1, named parispolyside F, and a novel derivation of phenolic glycoside 2, named parispolyside G, as well as two known flavonoid glycosides were isolated from the rhizome of Paris polyphylla var. yunnanensis. Their structures were elucidated by spectroscopic methods.     

One model of fatigue crack growth

A model for crack growth is proposed based on studies of the variation in the curvature radius at the crack tip during cyclic loading. Relations are obtained between mechanical material characteristics, crack geometry, and the rate of crack growth in a structure under cyclic loading. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 4, pp. 167–175, July–August, 2009.     

The Fruits of Paris polyphylla Inhibit Colorectal Cancer Cell Migration Induced by Fusobacterium nucleatum-Derived Extracellular Vesicles

Colorectal cancer (CRC) is one of the most common cancers worldwide. Gut microbiota are highly associated with CRC, and Fusobacterium nucleatum was found to be enriched in CRC lesions and correlated with CRC carcinogenesis and metastases. Paris polyphylla is a well-known herbal medicine that showed anticancer activity. The present study demonstrates that P. polyphylla inhibited the growth of CRC cells. In addition, treating with active compounds pennogenin 3-O-beta-chacotrioside and polyphyllin VI isolated from P. polyphylla inhibited the growth of F. nucleatum. We also found that extracellular vesicles (EVs) released from F. nucleatum could promote mitochondrial fusion and cell invasion in CRC cells, whereas active components from P. polyphylla could dampen such an impact. The data suggest that P. polyphylla and its active ingredients could be further explored as potential candidates for developing complementary chemotherapy for the treatment of CRC.