A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major ...A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major components of this protective system as for example an intact epithelium, the synthesis of various antimicrobial peptides (AMPs) and the formation of the mucus layer. We highlight the crucial importance of their correct functioning for the maintenance of a proper intestinal function and the prevention of dysbiosis and disease. Barrier disturbances including a defective production of AMPs, alterations in thickness or composition of the intestinal mucus layer, alterations of pattern-recognition receptors, defects in the process of autophagy as well as unresolved endoplasmic reticulum stress result in an inadequate host protection and are thought to play a crucial role in the pathogenesis of the inflammatory bowel diseases Crohn’s disease and ulcerative colitis.展开更多
ABSTRACT In this paper, interannual variations in the barrier layer thickness (BLT) are analyzed using Argo three-dimensional temperature and salinity data, with a locus on the effects of interannually varying sali...ABSTRACT In this paper, interannual variations in the barrier layer thickness (BLT) are analyzed using Argo three-dimensional temperature and salinity data, with a locus on the effects of interannually varying salinity on the evolution of the El Nifio Southern Oscillation (ENSO). The interannually varying BLT exhibits a zonal seesaw pattern across the equatorial Pacific during ENSO cycles. This phenomenon has been attributed to two different physical processes. During E1 Nifio (La Nifia), the barrier layer (BL) is anomalously thin (thick) west of about 160°E, and thick (thin) to the east. In the western equatorial Pacific (the western part: 130°-160°E), interannual variations of the BLT indicate a lead of one year relative to those of the ENSO onset. The interannual variations of the BLT can be largely attributed to the interannual temperature variability, through its dominant effect on the isothermal layer depth (ILD). However, in the central equatorial Pacific (the eastern part: 160~E- 170~W), interannual variations of the BL almost synchronously vary with ENSO, with a lead of about two months relative to those of the local SST. In this region, the interannual variations of the BL are significantly affected by the interannually varying salinity, mainly through its modulation effect on the mixed layer depth (MLD). As evaluated by a onedimensional boundary layer ocean model, the BL around the dateline induced by interannual salinity anomalies can significantly affect the temperature fields in the upper ocean, indicating a positive feedback that acts to enhance ENSO.展开更多
The formation of the barrier layer of anodic porous alumina film has been investigated in phosphoric acid solution. The results show that with the increase of phosphoric acid concentration,the time needed to form barr...The formation of the barrier layer of anodic porous alumina film has been investigated in phosphoric acid solution. The results show that with the increase of phosphoric acid concentration,the time needed to form barrier layer is shortened,and also the barrier layer becomes thinner. The phenomenon can be interpreted reasonablyby the stress concentration that developed in barrier layer.展开更多
基金Supported by Robert Bosch Foundation,Stuttgart,Germany
文摘A complex mucosal barrier protects as the first line of defense the surface of the healthy intestinal tract from adhesion and invasion by luminal microorganisms. In this review, we provide an overview about the major components of this protective system as for example an intact epithelium, the synthesis of various antimicrobial peptides (AMPs) and the formation of the mucus layer. We highlight the crucial importance of their correct functioning for the maintenance of a proper intestinal function and the prevention of dysbiosis and disease. Barrier disturbances including a defective production of AMPs, alterations in thickness or composition of the intestinal mucus layer, alterations of pattern-recognition receptors, defects in the process of autophagy as well as unresolved endoplasmic reticulum stress result in an inadequate host protection and are thought to play a crucial role in the pathogenesis of the inflammatory bowel diseases Crohn’s disease and ulcerative colitis.
基金supported by the National Basic Research Program of China (Grant No.2012CB955202)the National Natural Science Foundation of China (Grant No.41176014)
文摘ABSTRACT In this paper, interannual variations in the barrier layer thickness (BLT) are analyzed using Argo three-dimensional temperature and salinity data, with a locus on the effects of interannually varying salinity on the evolution of the El Nifio Southern Oscillation (ENSO). The interannually varying BLT exhibits a zonal seesaw pattern across the equatorial Pacific during ENSO cycles. This phenomenon has been attributed to two different physical processes. During E1 Nifio (La Nifia), the barrier layer (BL) is anomalously thin (thick) west of about 160°E, and thick (thin) to the east. In the western equatorial Pacific (the western part: 130°-160°E), interannual variations of the BLT indicate a lead of one year relative to those of the ENSO onset. The interannual variations of the BLT can be largely attributed to the interannual temperature variability, through its dominant effect on the isothermal layer depth (ILD). However, in the central equatorial Pacific (the eastern part: 160~E- 170~W), interannual variations of the BL almost synchronously vary with ENSO, with a lead of about two months relative to those of the local SST. In this region, the interannual variations of the BL are significantly affected by the interannually varying salinity, mainly through its modulation effect on the mixed layer depth (MLD). As evaluated by a onedimensional boundary layer ocean model, the BL around the dateline induced by interannual salinity anomalies can significantly affect the temperature fields in the upper ocean, indicating a positive feedback that acts to enhance ENSO.
文摘The formation of the barrier layer of anodic porous alumina film has been investigated in phosphoric acid solution. The results show that with the increase of phosphoric acid concentration,the time needed to form barrier layer is shortened,and also the barrier layer becomes thinner. The phenomenon can be interpreted reasonablyby the stress concentration that developed in barrier layer.