Molecular transport through a bottleneck driven by external force

The transport phenomena of Lennard-Jones molecules through a structural bottleneck driven by an external force are investigated by molecular dynamics simulations. We observe two distinct molecular flow regimes distinguished by a critical external force $F_{c}$ and find scaling behaviors between external forces and flow rates. Below the threshold $F_{c}$, molecules are essentially stuck in the bottleneck due to the attractive interaction between the molecules, while above $F_{c}$, molecules can smoothly move in the pipe. A critical flow rate $q_{c}$ corresponding to $F_{c}$ satisfies a simple relationship with angles and the value of $q_{c}$ can be estimated by a simple argument. We further clarify the role of the temperature dependence in the molecular flows through the bottleneck.Comment: 14 pages, 12 figure

The Role of Cholesterol in the Pathogenesis of Hypertension- Associated Nonalcoholic Steatohepatitis

Dietary cholesterol is a crucial risk factor for nonalcoholic steatohepatitis (NASH). Our recent studies indicated that high cholesterol intake was associated with the pathogenesis of hypertension-associated NASH. We developed a novel hypertensive rat model of NASH by feeding stroke-prone spontaneously hypertensive rats (SHRSP5/Dmcr) a high fat and cholesterol (HFC) diet. Histological features resembling human NASH were observed in this model. Furthermore, we investigated the kinetics of cholesterol in the rats fed an HFC diet and determined that suppression of bile acid (BA) detoxification led by HFC feeding results in cytotoxic BA accumulation in hepatocytes, which induces inflammatory response and liver damage. Sex differences in fibrogenesis were also observed in this model, and we found this was associated with a different ability in BA detoxification. Since SHRSP5/Dmcr rats are hypertensive, we investigated the role of hypertension in NASH progression by comparing NASH development among SHRSP5/Dmcr rats, spontaneously hypertensive rats and their original strain, Wistar Kyoto, with normal blood pressure. HFC diet induced more severe hepatic fibrosis in the hypertensive strains compared with the normotensive one. In conclusion, dietary cholesterol plays an essential role in the pathogenesis of NASH, and the combined action of cholesterol and hypertension further aggravates its progression

Characterization of Polystyrene in Methyl Ethyl Ketone by Small-Angle X-Ray Scattering

Molecular and thermodynamic properties of polystyrene in methyl ethyl ketone were studied by a small-angle X-ray scattering with a Kratky camera. The molecular weight, radius of gyration, second virial coefficient, mass per unit length, hydrodynamic length, radius of gyration of cross section, persistence length, and radius of cross section were estimated. Some of these values were compared with the values determined by other methods. Both values agreed well each other

Survivable MPLS Over Optical Transport Networks: Cost and Resource Usage Analysis

In this paper we study different options for the survivability implementation in MPLS over Optical Transport Networks (OTN) in terms of network resource usage and configuration cost. We investigate two approaches to the survivability deployment: single layer and multilayer survivability and present various methods for spare capacity allocation (SCA) to reroute disrupted traffic. The comparative analysis shows the influence of the offered traffic granularity and the physical network structure on the survivability cost: for high bandwidth LSPs, close to the optical channel capacity, the multilayer survivability outperforms the single layer one, whereas for low bandwidth LSPs the single layer survivability is more cost-efficient. On the other hand, sparse networks of low connectivity parameter use more wavelengths for optical path routing and increase the configuration cost, as compared with dense networks. We demonstrate that by mapping efficiently the spare capacity of the MPLS layer onto the resources of the optical layer one can achieve up to 22% savings in the total configuration cost and up to 37% in the optical layer cost. Further savings (up to 9 %) in the wavelength use can be obtained with the integrated approach to network configuration over the sequential one, however, at the increase in the optimization problem complexity. These results are based on a cost model with different cost variations, and were obtained for networks targeted to a nationwide coverage

Visualization of Laterally Spreading Colorectal Tumors by Using Image-Enhanced Endoscopy

Laterally spreading tumors may sometimes evade detection by colonoscopy. This study aimed to evaluate the use of image-enhanced endoscopy for visualizing laterally spreading tumors of the nongranular type. We reviewed consecutive patients with 47 non-granular-type laterally spreading tumors that had been examined using white-light imaging, autofluorescence imaging, narrow-band imaging, and chromoendoscopy with indigo carmine. The quality of visualization was evaluated using a 5-point scale by less- and more-experienced endoscopists. Autofluorescence imaging provided significantly better visualization than white-light imaging for both less-experienced and experienced endoscopists. On the other hand, no significant differences were observed between the quality of visualization provided by white-light imaging and narrow-band imaging for less-experienced endoscopists. Autofluorescence imaging provides high-quality visualization of non-granular-type laterally spreading tumors on still images. Multicenter trials should be conducted to confirm the usefulness of autofluorescence imaging in detecting laterally spreading colorectal tumors

Optimized Design of Survivable MPLS over Optical Transport Networks. Optical Switching and Networking

In this paper we study different options for the survivability implementation in MPLS over Optical Transport Networks in terms of network resource usage and configuration cost. We investigate two approaches to the survivability deployment: single layer and multilayer survivability and present various methods for spare capacity allocation (SCA) to reroute disrupted traffic. The comparative analysis shows the influence of the traffic granularity on the survivability cost: for high bandwidth LSPs, close to the optical channel capacity, the multilayer survivability outperforms the single layer one, whereas for low bandwidth LSPs the single layer survivability is more cost-efficient. For the multilayer survivability we demonstrate that by mapping efficiently the spare capacity of the MPLS layer onto the resources of the optical layer one can achieve up to 22% savings in the total configuration cost and up to 37% in the optical layer cost. Further savings (up to 9 %) in the wavelength use can be obtained with the integrated approach to network configuration over the sequential one, however, at the increase in the optimization problem complexity. These results are based on a cost model with actual technology pricing and were obtained for networks targeted to a nationwide coverage