Local buckling behavior of buried pipeline under seismic oblique-reverse fault displacement.

Seismic fault displacement is the main factor leading to local buckling failure of the buried pipeline, especially crossing the oblique-reverse fault. The local buckling behavior of the buried pipeline is complex under the 3-D displacement of the oblique-reverse fault. In this work, the pipe local buckling mechanism was discussed, then a shell and solid element nonlinear contact coupling model of the pipeline crossing oblique-reverse fault was established based on the ABAQUS program. The local buckling behavior (potential local buckling locations, developing process) of the pipeline under oblique-reverse fault displacement was systematically analyzed, comparing against the same under single fault displacement. Subsequently, the influence of internal pressure, diameter thickness ratio and burial depth on the local buckling behavior of the pipeline were discussed. The numerical results revealed two potential locations and three stages of the local buckling, then the potential local buckling locations and three stages of the local buckling under different internal pressure, diameter thickness ratio and burial depth were obtained. It proves that the local buckling of the pipeline is more sensitive to the oblique-reverse fault displacement than single fault displacement and provides a reference for the aseismic design and reinforcement of the pipeline crossing the oblique-reverse fault.

Serious consequences of Epstein-Barr virus infection: Hemophagocytic lymphohistocytosis.

Human is the host of the Epstein-Barr virus (EBV) especially in childhood and adolescence. Most of them are asymptomatic infection and self-limiting. However, for those patients who suffer from immune dysfunction, EBV infection will be life-threatening. Epstein-Barr virus-associated hemophagocytic lymphohistocytosis (EBV-HLH) is one of the severe effects. The diagnosis and differential diagnosis of EBV-HLH and other EBV infectious diseases are mentioned in this paper. The molecular biology mechanism and complications of EBV-HLH are equally briefly presented. It also provides a practical method for the genetic diagnosis of such diseases and the differential diagnosis with other human immunodeficiency diseases for medical scientists in routine clinical practice.

[Isolation and identification of impurities from raw material of clindamycin phosphate].

Four impurities were isolated from raw material of clindamycin phosphate (CP), and their structures have been determined. LC-MS was used to determine the molecular weights of the impurities in the raw material of CP. Reversed-phase preparative HPLC was used to prepare them, and their chemical structures were identified by HR-MS and NMR. The four unknown impurities were determined as clindamycin-B-phosphate (1), clindamycin-2,4-diphosphate (2), 3',6'-dehydro clindamycin phosphate (3), epi-clindamycin phosphate (4). Impurity 1 has been included in BP and EP, while 2, 3 and 4 have not. The impurities 2, 3, 4 are first separated from raw material of CP.