325 research outputs found
Spring-block friction model for landslides: Application to Vaiont and Maoxian landslides
It is necessary to study the kinematics of landslide prior to its failure for
accurately estimating the time of landslide instability. Based on a spring
block model, considering the Dieterich Ruina's friction, the kinematic
displacement and velocity of landslide along the slip surface are analyzed
under quasistatic approximation. A algebraic relationship including three
parameters between the displacement (or velocity) and time is obtained, and
then applied to two typical landslides: Vaiont in Italy, and Maoxian in China.
The results show that the proposed spring block friction model can well
describe the kinematic data of landslides before their failure. If the
effective data of displacement can be obtained to determine the three
parameters above, this simple physical model could be used to estimate the time
of landslide instability. This spring block friction model also provides clear
physical basis for the usual inverse velocity method of the landslide warning,
the stick slip of some landslides, and the scaling relationship between the
numbers of the landslides and their volume.Comment: 16 pages; 7 figures; 1 Tabl
Bis(2-cyclohexyliminomethyl-4,6-disulfanylphenolato)nickel(II) acetonitrile solvate
In the title compound, [Ni(C13H16NOS2)2]·CH3CN, the NiII atom is four-coordinated by two N,O-bidentate Schiff base ligands, resulting in a distorted tetrahedral coordination for the metal ion
Diaquabis[3-(2-sulfanylphenyl)prop-2-enoato]zinc(II) dihydrate
In the title compound, [Zn(C9H7O2S)2(H2O)2]·2H2O, the ZnII atom (site symmetry ) is four-coordinated by two O atoms from 3-(2-sulfanylphenyl)prop-2-enoate anions and two aqua O atoms in a slightly distorted ZnO4 square-planar arrangement. In the crystal, O—H⋯O hydrogen bonds help to establish the packing
Bis{2-[3-(dimethylamino)propyliminomethyl]-4,6-disulfanylphenolato}cobalt(II)
In the title mononuclear complex, [Co(C12H17N2OS2)2], the CoII atom is four-coordinated by two N,O-bidentate Schiff base ligands, resulting in a slightly distorted trans-CoN2O2 square-planar coordination
Relationship of cumulative dust exposure dose and cumulative abnormal rate of pulmonary function in coal mixture workers
AbstractTo investigate the dose-response relationship between cumulative dust exposure (CDE) and cumulative abnormal rate of pulmonary function in coal mixture workers. Three hundred and twenty eight coal mixture workers (exposed group) and 169 nondust-exposed workers (control group) were recruited. Basic information data were collected and pulmonary function tests were performed. Pulmonary function was compared between the two groups after comparing smoking behaviors. Pulmonary function indices [forced vital capacity in 1 second after full inspiration (FVC)%, forced expiratory volume (FEV)1%, and FEV1/FVC%] were compared among groups stratified by service length (exposure duration). The relationship between CDE dose and cumulative abnormal rate of pulmonary function in coal mixture workers was analyzed. Abnormal rate of pulmonary function in the exposed group (35.1%) was significantly higher than the control group (10.1%; p < 0.001); FVC%, FEV1%, and FEV1/FVC% in the exposed group decreased significantly compared with the control group (all p < 0.05). Differences in FVC%, FEV1%, and FEV1/FVC% among coal mixture workers stratified by exposure duration in the exposed group were statistically significant (all p < 0.05). The discernible increase in the cumulative abnormal rate was observed, from ≥ 1000 mg/m3·years group to ≥ 1700 mg/m3·years group. Correlation analysis revealed a positive correlation between the CDE dose and the cumulative abnormal rate of pulmonary function. Higher abnormal pulmonary function rate was found among coal mixture workers, characterized by decreased pulmonary function indices. Our results suggested a positive relationship between CDE dose and cumulative abnormal pulmonary function rate, and a rapid increase in cumulative abnormal rate within a certain range of CDE dose. A lower limit value of 1000 mg/m3·years has reference significance
No relationship between the distribution of mast cells and the survival of stage IIIB colon cancer patients
<p>Abstract</p> <p>Background</p> <p>Mast cells promote the progression of experimental tumors and might be a valuable therapeutic target. However, the relevant clinical evidence is still controversial. This study analyzed the relationship between the distribution of mast cells and the survival of patients with colon cancer to study whether mast cells contribute to tumor progression.</p> <p>Materials and methods</p> <p>Ninety-three cases of pathologically confirmed primary cancer tissues matched with adjacent normal mucosa, metastases of regional-draining lymph nodes and regional-draining lymph nodes without metastases were collected from stage IIIB colon carcinoma patients between January 1997 and July 2004 at the Cancer Center of Sun Yat-Sen University. Tryptase-positive mast cells were counted. The relationships of the distribution of mast cells with clinicopathologic parameters and 5-year survival were analyzed.</p> <p>Results</p> <p>Although the mast cell count in the mucosa adjacent to the primary colon cancer was significantly higher than that in the stroma of the primary colon cancer, no difference in mast cell counts was observed between the stroma in lymph node metastasis and the lymph tissue adjacent to the metastasis. Additionally, the mast cell count in the regional-draining lymph node without the invasion of cancer cells was significantly higher than that in the stroma of lymph node metastasis and adjacent lymph tissue. However, none of those mast cell counts was related to 5-year survival.</p> <p>Conclusion</p> <p>Although mast cell count varied with location, none of the mast cell counts was related to 5-year survival, suggesting that mast cells do not contribute to the progression of stage IIIB colon cancer.</p
4-Thioxo-3,5-dithia-1,7-heptanedioic acid
The complete molecule of the title compound, C5H6O4S3, is generated by crystallographic twofold symmetry with the C=S group lying on the rotation axis. The molecules are linked through weak hydrogen-bond contacts by glide-plane operations to form R
2
2(20) rings and ladder-like C(4) chains along the c axis
Quantitative Proteomic Study of Human Lung Squamous Carcinoma and Normal Bronchial Epithelial Acquired by Laser Capture Microdissection
Objective. To investigate the differential protein profile of human lung squamous carcinoma (HLSC) and normal bronchial epithelium (NBE) and provide preliminary results for further study to explore the carcinogenic mechanism of HLSC. Methods. Laser capture microdissection (LCM) was used to purify the target cells from 10 pairs of HLSC tissues and their matched NHBE, respectively. A stable-isotope labeled strategy using iTRAQ, followed by 2D-LC/Q-STAR mass spectrometry, was performed to separate and identify the differential expression proteins. Results. A total of 96 differential expression proteins in the LCM-purified HLSC and NBE were identified. Compared with NBE, 49 proteins were upregulated and 47 proteins were downregulated in HLSC. Furthermore, the expression levels of the differential proteins including HSPB1, CKB, SCCA1, S100A8, as well as S100A9 were confirmed by western blot and tissue microarray and were consistent with the results of quantitative proteomics. Conclusion. The different expression proteins in HLSC will provide scientific foundation for further study to explore the carcinogenic mechanism of HLSC
[μ-N,N′-Bis(diphenylphosphinomethyl)benzene-1,4-diamine-κ2 P:P′]bis[(2,2′-bipyridine-κ2 N,N′)silver(I)] bis(perchlorate) acetone disolvate
The title complex, [Ag2(C10H8N2)2(C32H30N2P2)](ClO4)2·2CH3COCH3, is a centrosymmetric dimer with pairs of AgI atoms bridged by N,N′-bis(diphenylphosphinomethyl)benzene-1,4-diamine ligands. In addition, each AgI atom is coordinated by one chelating 2,2′-bipyridine ligand, giving a distorted trigonal coordination environment
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