三轴排水剪切下钙质砂的颗粒破碎特性

颗粒破碎是影响粒状土的变形和强度机理的重要因素。为了研究钙质砂在剪切过程中的颗粒破碎特性及其对变形和强度性质的影响,对3种不同初始分布的钙质砂进行了不同围压下的三轴排水剪切试验。结果显示:初始分形的粒径分布在三轴剪切过程中始终保持着较为严格的分形特性,该现象与各粒组中的破碎颗粒主要向相邻的下一级粒组中迁移的机制有关。钙质砂的应力–应变特性与围压大小和初始粒径分布有关,围压越低,初始粒径分布越不均匀,钙质砂的剪胀效应越显著。随着围压的增大,钙质砂的剪胀倾向减少,并逐渐过渡到剪缩状态。钙质砂的破碎率随剪切过程中的应力和应变的增长而增大,其峰值内摩擦角随着破碎率的增大而降低,最后趋于定值。用非线性的指数函数来描述峰值内摩擦角与破碎率的相关关系,揭示了颗粒破碎对钙质砂抗剪强度的影响规律。

Relationship between expression of CD105 and growth factors in malignant tumors of gastrointestinal tract and its significance

AIM: Angiogenesis is an important step in the growth of solid malignant tumors. A number of angiogenic factors have been found such as transforming growth factorβ1 (TGF-β1)and vascular endothelial growth factor (VEGF). However,the roles of TGFβ1 and VEGF in gastrointestinal carcinogenesis are still unclear. This study was to investigate the expressions of TGF-β1 and VEGF in gastrointestinal tract malignant tumors, as well as their association with microvessel density (MVD). At the same time, we also observed the localization of TGF-β1 and its receptor CD105 in gastric malignant tumors.METHODS: The expressions of TGF-β1 and CDL05 were detected in 55 fresh specimens of gastric carcinoma and VEGF and CD105 in 44 fresh specimens of colorectal carcinoma by immunohistochemical staining (S-ABC). TGF-β1 and CD105 in 55 gastric carcinoma tissues on the same slide were detected by using double-stain Tmmunohistochemistry (DS-ABC).RESULTS: Among the 55 cases of gastric carcinoma tissues,30 were positive for TGF-β1 (54.55 %). The MVD of TGF-β1 strong positive group (++～+++ 23.22±5.8) was significantly higher than that of weak positive group (+17.56±7.2) and negative group (- 17.46±3.9) (q=4.5, q=5.3207, respectively,P＜0.01). In the areas of high expression of TGF-β1, MVD and the expression of CD105 were also high. Among the 44 cases of colonic carcinoma tissues, 26 were positive for VEGF (59.1%). The expressions of both VEGF and CD105 (MVD)were related with the depth of invasion (F=5.438, P＜0.05;F=4.168, P=0.05), lymph node metastasis (F=10.311, P＜0.01;F=20.282, P＜0.01) and Dukes stage (F=6.196, P＜0.01;F=10.274, P＜0.01), but not with histological grade (F=0.487,P＞0.05). There was a significant correlation between the expression of VEGF and CD105 (MVD) (r=0.720, P＜0.01).CONCLUSION: Over-expression of TGF-β1 and VEGF acts as stimulating factors of angiogenesis in gastrointestinal tumors.CD105, as a receptor of TGF-β1, can regulate the biological effect of TGF-β1 in tumor angiogenesis. MVD marked by CD105 is more suitable for detecting newborn blood vessels.

Expression of e-cadherin and β-catenin in human esophageal squamous cell carcinoma: relationships with prognosis

AIM: To elucidate the expression of E-cadherin and β-catenincorrelating with its clinical outcome in patients withesophageal squamous cell carcinoma (ESCC), by analyzingtheir interrelationship with clinicopathological variables andtheir effects on progress and prognosis.METHODS: Expression of E-cadherin and β-catenin wasdetermined by SP immunohistochemical technique inpatients with ESCC consecutively, their correlation withclinical characteristics was evaluated and analyzed bymultivariate analysis.RESULTS: The rate of expression of E-cadherin decreasedto 66.03 % (70/106) in ESCC and the protein level wasnegative correlated with histologic grade, tumor size, clinicalstaging, lymph node metastasis and venous invasion.Whereas the expression rate of β-catenin was reduced to69.8 % (74/106) and the level of protein expressioncorrelated only with histologic grade. There obviously existedinverse correlation between level of E-cadherin protein andsurvival, especially in .stage I, IIa, IIb (P=0.0033), Patientswith low-expressing tumors for β-catenin and non-expressingtumors for E-cadherin/β-catenin had lower survival periodthan those with normal-expressing ones (P=0.0501 andP=0.0080, respectively). Patients with diminished expressionof E-cadherin as grade Ⅱ or Ⅲ had shorter survival periodthan those with normally expressing and grade Ⅰ, nosignificance existed between grade I and grade Ⅱ or Ⅲwith respect to different status of E-cadherin expression.Furthermore, Correlation analysis showed level of E-cadherincorrelated with that of β-catenin (P=0.005). Cox proportionalhazards model analysis suggested downregulation of E-cadherin was an important factor indicating poor prognosis.CONCLUSION: As a probable independent prognosticfactor, it correlates with overall and disease free survivalperiod, expression of E-cadherin but not β-catenin maypredict prognosis in patients with ESCC.

Hydroaminomethylation of 1-Dodecene Catalyzed by Water-soluble Rhodium Complex

The hydroaminomethylation of 1-dodecene catalyzed by water soluble rhodium complex RhCl(CO)(TPPTS)2 in the presence of surfactant CTAB was investigated. High reactivity and selectivity for tertiary amine were achieved under relatively mild conditions.

Failure analysis of corrosion cracking and simulated testing for a fluid catalytic cracking unit

The failure of a fluid catalysis and cracking unit (FCCU) in a Chinese refinery was investigated by using nondestructive detection methods, fracture surface examination, hardness measurement, chemical composition and corrosion products analysis. The results showed that the failure was caused by the dew point nitrate stress corrosion cracking. For a long operation period, the wall temperature of the regenerator in the FCCU was below the fume dew point. As a result, an acid fume NOx-SOx-H2O medium present- ed on the surface, resulting in stress corrosion cracking of the component with high residual stress. In order to confirm the relative conclusion, simulated testing was conducted in laboratory, and the results showed similar cracking characteristics. Finally, some sug- gestions have been made to prevent the stress corrosion cracking of an FCCU from re-occurring in the future.

Primary Renal Malignant Fibrous Histiocytoma Four-Case Report and Review of the Literature

OBJECTIVE To evaluate the diagnosis and treatment for primary renal malignant fibrous histiocytoma, a rare tumor arising from the kidney.METHODS The clinical and pathological data from 4 cases of malignant fibrous histiocytoma of the kidney detected in our hospital are described.One case of special interest involved a giant cell subtype, the first to be reported in the oncology literature. The clinicopathologic features and prognostic factors of this tumor were analysed and summarized after reviewing 55 documented cases in the English and Chinese literature.RESULTS A palpable mass (71.2%), emaciation (54.2%) and pain (54,2%) were common manifestations in renal MFH, Of all the cases, 51 were identified as a storiform-pleomorphic subtype by pathologists. Inconsideration of all the prognosis related factors, the residual tumor and high TNM stage predicted a shortened survival duration, but the symptom of a fever served as a better prognostic factor.CONCLUSION Malignant fibrous histiocytoma which arises from the kidney is a rare pathologic type, and possesses a high tendency towards local recurrence and distant metastasis. Despite the poor prognosis, early detection and radical surgery can prolong survival in selected cases.