Stress Distribution Around a Tunnel with an Arbitrary Cross Section Excavated in Anisotropic Elastic Ground

The present paper is concerned with the theoretical determination of stresses and deformations around a tunnel with an arbitrary cross section excavated in anisotropic elastic ground under a three-dimensional stress state. In the first part general methods are proposed for determining these phenomena based on the use of comformal mappings, and in the second are given the numerical results of computation of some typical cross sections

Stress Distribution for Anisotropic Elastic Plate Containing Two or More Arbitrary Elliptical Holes

The theoretical solution by successive approximation utilizing the complex variable method is obtained for the case of an infinite anisotropic elastic plate containing two or more arbitrary elliptical holes under applied external stress at infinity. For the particular cases of isotropic plate involving two or three circular holes, the numerical results obtained by the present method are quite in agreement with the results obtained by others

The Theory of the Determination of Stress in an Anisotropic Elastic Medium Using an Instrumented Cylindrical Inclusion

The present paper describes the theoretical aspect of the determination of the stresses in rock unaffected by a borehole with an instrumented cylindrical inclusion. The stress fields of the elastic matrix (isotropic or anisotropic) containing a cylindrical inclusion are discussed and the formulae to be used in practice to determine the stresses in rock are presented. The results of calculation are shown by several numerical examples

Some Considerations for Measurements of Stresses in Rock Masses by the Use of Photoelastic Gages

In the first part of the present paper some considerations are made for several inherent problems to the stress measurements by the use of photoelastic gages such as the influences of the thickness of the binding agent, relative stiffness of the agent to the gage, the ratios of the depth of the bored hole to that of the gage and the ratios of the diameter of the overcoring to that of the bored hole. In the second part applications of the photoelastic gages to the stress measurements in orthotropic rock masses are discussed

Pharmacokinetic study of pleural fluid penetration of carbapenem antibiotic agents in chemical pleurisy

SummaryStudy objectivesWe investigated pleural fluid penetration of carbapenem antibiotic agents [imipenem (IPM), panipenem (PAPM), meropenem (MEPM), and biapenem (BIPM)] using an experimental rabbit pleuritis model to clarify the usefulness of the carbapenem agents for the treatment of bacterial pleurisy or pyothorax.Measurements and resultsSerum and pleural fluid specimens were serially collected at 5, 10, 15, 30, 60, 90, 120, 180, 240, 300, and 360min after antibiotic administration for measurement of antibiotic levels. We investigated each agent alone as well as drug solutions containing each agent and a dehydropeptidase-I-specific inhibitor, cilastatin (CS), to remove the influence of dehydropeptidase-I-related hydrolysis. Groups of animals (n=3) received each carbapenem agent with or without CS. Serum and pleural fluid antibiotic levels were measured by high-performance liquid chromatography (HPLC). Because Cmax is not useful for evaluating the antimicrobial effects of carbapenem antibiotic agents due to their dose-dependent antimicrobial activity, we also investigated the AUC, which is correlated with the total drug levels in vivo.Among the drug solutions containing CS, MEPM/CS had the highest pleural fluid AUC0–360 (1594.8±510.3μgmin/ml), and the highest pleural fluid AUC0–360/plasma AUC0–360 ratio (0.79±0.04). BIPM/CS had the highest plasma AUC0–360 (3040.1±1525.9μgmin/ml). In pleural fluid AUC0–360/plasma AUC0–360 ratio MEPM/CS was significantly higher than those for the remaining agents. In pleural fluid AUC0–360 and plasma AUC0–360 there were no significant differences among these mixed solutions.ConclusionsMEPM had the most favorable pleural fluid penetration. Pleural fluid penetration should be examined in infection models and in clinical trials

Klf5 suppresses ERK signaling in mouse pluripotent stem cells

Mouse embryonic stem cells (ESCs) are pluripotent stem cells, which have the ability to differentiate into all three germ layers: mesoderm, endoderm, and ectoderm. Proper levels of phosphorylated extracellular signal-regulated kinase (pERK) are critical for maintaining pluripotency, as elevated pERK evoked by fibroblast growth factor (FGF) receptor activation results in differentiation of ESCs, while, conversely, reduction of pERK by a MEK inhibitor maintains a pluripotent ground state. However, mechanisms underlying proper control of pERK levels in mouse ESCs are not fully understood. Here, we find that Klf5, a Krüppel-like transcription factor family member, is a component of pERK regulation in mouse ESCs. We show that ERK signaling is overactivated in Klf5-KO ESCs and the overactivated ERK in Klf5-KO ESCs is suppressed by the introduction of Klf5, but not Klf2 or Klf4, indicating a unique role for Klf5 in ERK suppression. Moreover, Klf5 regulates Spred1, a negative regulator of the FGF-ERK pathway. Klf5 also facilitates reprogramming of EpiSCs into a naïve state in combination with a glycogen synthase kinase 3 inhibitor and LIF, and in place of a MEK inhibitor. Taken together, these results show for the first time that Klf5 has a unique role suppressing ERK activity in mouse ESCs