Subloading-damage model and its extension to unilateral damage effect

The elastoplastic constitutive equation with the damage is formulated incorporating the subloading surface model. Further, it is extended to describe the unilateral damage phenomenon by formulating the actual Young’s modulus tensor as the function of the signs of the principal actual damaged stresses and the damage variable. Here, we may perform the ordinary deformation analysis simply in the virtual undamaged state

Complete formulation of the subloading surface model

The subloading surface model is endowed the noticeable ability to describe the wide classes of irreversible mechanical behavior [1]. However, the past formulations of the subloading surface model have contained several inexact equations, which have been modified repeatedly after the concept of the subloading surface was proposed in 1977 [2]. The exact formulation is presented first in this article for the hypoelastic-based plasticity, which enjoys the distinguished superiority in the both aspects of the description of material behavior in high accuracy and of the numerical calculation in high efficiency

Accurate prediction of spring-back phenomenon by subloading surface mode

The subloading surface model possesses the distinguished capability to describe the plastic strain rate for the rate of stress inside the yield surface accurately and the stresscontrolling function to pull-back the stress to the yield surface even when it goes out from the yield surface in the numarical calculation. The spring-back phenomenon of the high strength steel is analyzed by the commercial software Marc implemented the subloading surface model and thus the high accuracy of the simulation is verified in this article

Unified description of dry and fluid frictions by subloading-overstress friction model

The subloading-overstress friction model is formulated for the unified description of the dry and the fluid frictions which exhibit the negative and the positive rate dependences, i.e. the decrease and the increase, respectively, of friction resistance. The validity of this model will be verified by the comparisons with test data in this article

Seismic response analysis by subloading surface model

A lot of disaster by liquefaction have been reported in area along the shore of Japan. In particular, liquefaction has occurred in the wide area in the Great East Japan Earthquake of 2011. Various approaches for the liquefaction analysis have been proposed up to present. Among these approaches, the subloading surface model is formulated in the framework of the plasticity model and thus it is expected to provide a highly pertinent simulation of cyclic loading behaviour of materials. Further, the explicit constitutive equation of soils has been formulated to describe the cyclic loading behaviour with the cyclic mobility [1]. In this study, the validity of the liquefaction analysis by the subloading surface model is examined by comparing the simulation by the subloading surface model with the actual record for the acceleration wave in the ground surface to the input of the actual data of the acceleration wave in the soil ground base. The actual data used in the simulation was recorded in the Kushiro earthquake in 1993

Elastoplastic analysis of mises metal by return-mapping algorithm for extended subloading surface model

The extended subloading surface model is capable of representing not only monotonic but also cyclic loading behaviors accurately. The various return-mapping methods have been adopted to for the elastoplastic deformation analysis in FEM incorporating the subloading surface model. However, the past algorithms based on the expansion of the subloading surface is inapplicable to the cyclic loading behaviors. Then, the rigorous complete integration algorithm for Mises metal is adopted in this study. Additionally, it is implemented into the FEM software ABAQUS through the user-subroutine UMAT. The numerical calculations are performed for the forward and inverse loading processes by use of the proposed and the past implicit algorithms. A more accurate elastoplastic deformation analyses can be conducted by the proposed algorithm. Thus, it may be stated that the accurate numerical solution can be attained by adopting the proposed return-mapping algorithm for the general loading process

The Role of miRNAs in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a genetic heterogeneous disease with high mortality and poor prognosis. IPF is characterized by persistent fibroblasts and relentless accumulation of collagen matrix. Epithelial-mesenchymal transition (EMT) and endothelial-to-mesenchymal transition (EndoMT) contribute to the progression of the fibrotic process. There are some therapeutic drugs that delay this progress, but eradicative medicine does not exist yet. MicroRNAs (miRNAs) are short single-stranded RNAs that regulate posttranscriptional silencing. Recent reports have shown that miRNAs play important roles in the development of IPF, as different expression levels of miRNAs in blood and lung tissue from IPF patients were closely associated with the occurrence of IPF disease. In this chapter, we will discuss the role of miRNAs in the pathogenesis, diagnosis, and treatment of IPF. In particular, we will focus on the regulation of EMT/EndoMT by miRNAs

Effects of Preoperative Use of an Immune-Enhancing Diet on Postoperative Complications and Long-Term Outcome: A Randomized Clinical Trial in Colorectal Cancer Surgery in Japanese Patients

Background: Despite recent advances in surgical techniques and perioperative management, postoperative infectious complications remain a problem in surgical patients. We performed a prospective randomized clinical trial to examine the effects of preoperative Immune Enhancing Diets (IEDs) on postoperative complications in Japanese patients who underwent curative colorectal cancer surgery. This study was also designed to evaluate the optimal dose of preoperative IEDs for the patients without malnutrition. Finally, we analyzed recurrence free survival (RFS) and disease-specific survival (DSS) after surgery in patients who did and did not receive IEDspreoperatively.Material and Methods: This was a prospective, randomized clinical trial conducted at the Department of Surgery, National Defense Medical College, from October 2002 to October 2005. The 88 patients undergoing colorectal surgery were enrolled and were randomly divided into 3 groups. The high- (High, N=26) and low- (Low, N=31) dose groups received normal food and, respectively, 750ml/day or 250ml/ day of IEDs for 5 days before the operation. The primary endpoint was the rates of surgical site infection (SSI) and non- infectious complications. We also evaluated the RFS and DSS rate, respectively. Results: The patients were followed for 77±10 months (9-133 months) after surgery. Incisional SSI rates in the IEDs (High and Low) groups were significantly lower than in the Control group. (0%*, 0%* and 17%) (*P<0.01 vs. Control) The incidences of the infections not involving the surgical site (non-SSI) and the lengths of hospital stay were similar among the three groups. No significant differences were observed in RFS or DSS.Conclusion: In Japanese patients undergoing colorectal cancer surgery, preoperative IEDs significantly reduced the rate of incisional SSI as compared with the control group. Very interestingly, in Japanese patients, preoperative 250ml/day IED intake may be adequate for colorectal cancer patients without malnutrition. However, with regard to the long term outcome, beneficial effects of preoperative IEDs are not evident

Characteristics and disease severity of healthcare-associated pneumonia among patients in a hospital in Kitakyushu, Japan.

Healthcare-associated pneumonia (HCAP) is a newly identified condition, and epidemiologic studies in Japan are still limited. We retrospectively observed patients with HCAP and community-acquired pneumonia (CAP) who were hospitalized between December 2004 and March 2005, and compared their disease characteristics. A total of 34 patients (14 with HCAP and 20 with CAP) were evaluated. Of the patients with HCAP, seven (50%) were hospitalized for at least 2 days in the preceding 90 days and five (35.7%) resided in a nursing home or extended care facility. Compared with patients with CAP, patients with HCAP were older, had more complications, including central nerve diseases, had greater disease severity, but lower serum albumin level. More methicillin-resistant Staphylococcus aureus, Pseudomonas spp., and anaerobes were isolated from patients with HCAP than from those with CAP. Conversely, more Streptococcus pneumoniae was detected and more penicillin was used in patients with CAP. This study provides additional evidence that HCAP should be distinguished from CAP and suggests the pathogenesis and therapeutic strategy for HCAP may be similar to those for hospital-acquired pneumonia