Aim
The underlying mechanism of non‐obese non‐alcoholic fatty liver disease (NAFLD) has not been fully elucidated. We classified patients with NAFLD by sex and body mass index and compared their ...clinical features to clarify the background pathophysiology of non‐obese NAFLD.
Methods
A total of 404 patients with NAFLD were divided according to their body mass index (<25 non‐obese, 25 to <30 obese, and ≥30 severe obese), and were further compared with 253 patients without obesity and NAFLD (non‐NAFLD).
Results
The proportion of the individuals with non‐obese NAFLD was 25.7% in men and 27.6% in women. The male and female non‐obese NAFLD groups had lower skeletal muscle mass and muscle strength than the obese NAFLD groups. The visceral fat area, although low, was ≥100 cm2 in 59.3% of men and 43.8% of women. An increase in liver fat accumulation, hepatic fibrosis, homeostasis model assessment of insulin resistance, and leptin levels was modest in the non‐obese NAFLD group compared with a marked increase in the obese NAFLD groups. The muscle mass of the non‐obese NAFLD group was similar to that of the non‐NAFLD group, but muscle steatosis was particularly common among women. Multivariate analysis revealed that the factors contributing to increased liver fat accumulation in the non‐obese NAFLD group were visceral fat area, HbA1c, myostatin, and leptin.
Conclusions
In patients with non‐obese NAFLD, a sex difference was observed in the clinical features. In addition to increased visceral fat, decreased muscle mass and muscle strength, muscle atrophy (presarcopenia), and impaired glucose tolerance were considered to be important pathophysiological factors.
Glisson's capsule was discovered by Johannis Walaeus in 1640 and described by Francis Glisson in 1654. The capsule wraps the hepatic artery, the portal vein and the bile duct in the liver and forms ...bundles at the hepatic hilus and in the liver as the Glissonean pedicle tree. Glisson's capsule does not connect to the proper membrane of the liver, which was discovered by Laennec; therefore, the Glissonean pedicles can be detached from the liver parenchyma without liver dissection. Couinaud described three main approaches to control the inflow system at the hepatic hilus in liver surgery; the intrafascial approach, the extrafascial and transfissural approach, and the extrafascial approach. The intrafascial approach is the so‐called control method. The extrafascial and transfissural approach, and the extrafascial approach are recognized as the Glissonean pedicle approach. When the Glissonean pedicles are ligated before liver transection, various types of anatomical hepatectomy can be carried out. The Glissonean pedicle approach is, therefore, considered to be one of the most important procedures in liver surgery. We herein describe the historical aspects and procedures of the Glissonean pedicle approach in liver surgery.
When the Glissonean pedicles are ligated before liver transection, various types of anatomical hepactectomy can be performed. The Glissonean pedicle approach is, therefore, considered to be one of the most important procedure in liver surgery.
Background
The value of the hepatobiliary phase of gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) in patients with hepatocellular carcinoma (HCC) has not been ...evaluated in detail.
Methods
Between 2008 and 2009, 61 patients with HCC within the Milan criteria underwent Gd-EOB-DTPA-enhanced MRI and hepatectomy. The tumor margin was determined preoperatively based on hepatobiliary phase images. Microscopic portal vein invasion (MPVI), intrahepatic metastasis (IM), and recurrence of HCC within 1 year after hepatectomy were evaluated in 24 patients with non-smooth margins at the periphery of the tumor and 37 patients with smooth margins.
Results
The number of patients with MPVI and IM of HCC was significantly higher among those with non-smooth margins (42 and 38%, respectively) than among those with smooth margins (3%;
p
= 0.0002 and 5%;
p
= 0.0042, respectively). A non-smooth margin was identified as a significant predictor of MPVI (odds ratio 18.814,
p
= 0.024) and IM (odds ratio 6.498,
p
= 0.036) of HCC on multivariate analysis. Furthermore, a non-smooth margin was identified as a significant predictor of recurrence within 1 year after hepatectomy (odds ratio 4.306,
p
= 0.04) on multivariate analysis.
Conclusions
A non-smooth tumor margin in the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI is useful to predict MPVI, IM, and early recurrence of HCC after hepatectomy.
We aim to address the problem of finding a control input maximizing the time instants when all control channels take a zero‐value (are turned off) while stabilizing the system to zero over a given ...horizon length. This problem is called the maximum turn‐off control problem. To solve it, we reduce the problem into a block‐sparse optimization problem with respect to the control input sequence, where the ℓ2/ℓ0$$ {\ell}_2/{\ell}_0 $$ norm of the control input sequence is the objective function that must be minimized. Because the problem is not convex, we introduce a relaxed problem based on the ℓ2/ℓ1$$ {\ell}_2/{\ell}_1 $$ norm, which is a convex function, and characterize the equivalence relation between the original and relaxed problems using the so‐called block restricted isometry property (block‐RIP). Based on the equivalence, the solution can be obtained by solving the convex relaxed problem. However, the block‐RIP is not easy to interpret and verify. Thus, we propose the notion of sparse controllability Gramians, which is an extension of the controllability Gramians, and show that the block‐RIP can be interpreted by the eigenvalues of the sparse controllability Gramian. This study presents an easy‐to‐check condition of the block‐RIP. Moreover, the above control framework is extended to a model predictive control scheme. These results are demonstrated using numerical examples.
Sparse event‐triggered control of linear systems Banno, Ikumi; Azuma, Shun‐ichi; Ariizumi, Ryo ...
International journal of robust and nonlinear control,
10 January 2023, Letnik:
33, Številka:
1
Journal Article
Recenzirano
Odprti dostop
In event‐triggered control, a situation where the control input must be sparse often arises. Therefore, in this study, we propose sparse event‐triggered control, meaning that the control input is ...sparse and updated in an event‐triggered manner. First, we present a model‐based method for sparse event‐triggered control of linear systems, where the event condition is defined by a Lyapunov function. The resulting control input is proven to be sparse and the control system is confirmed to be asymptotically stable. Second, we extend it to a data‐driven version, where the event condition is adaptively updated from online data on the state trajectory. Finally, we discuss the possibility of extending our framework to two cases of disturbance and nonlinear dynamics.
In this paper, we prove the existence of a reservoir that has a finite-dimensional output and makes the reservoir computing model universal. Reservoir computing is a method for dynamical system ...approximation that trains the static part of a model but fixes the dynamical part called the reservoir. Hence, reservoir computing has the advantage of training models with a low computational cost. Moreover, fixed reservoirs can be implemented as physical systems. Such reservoirs have attracted attention in terms of computation speed and energy consumption. The universality of a reservoir computing model is its ability to approximate an arbitrary system with arbitrary accuracy. Two sufficient reservoir conditions to make the model universal have been proposed. The first is the combination of fading memory and the separation property. The second is the neighborhood separation property, which we proposed recently. To date, it has been unknown whether a reservoir with a finite-dimensional output can satisfy these conditions. In this study, we prove that no reservoir with a finite-dimensional output satisfies the former condition. By contrast, we propose a single output reservoir that satisfies the latter condition. This implies that, for any dimension, a reservoir making the model universal exists with the output of that specified dimension. These results clarify the practical importance of our proposed conditions.
Intrahepatic cholangiocarcinoma (ICC) is considered to be a fatal disease because of frequent recurrence despite curative surgery. The macroscopic classification of ICC in the General Rules for the ...Clinical and Pathological Study of Primary Liver Cancer of the Liver Cancer Study Group of Japan reflects tumor-spreading patterns; therefore, the clinicopathological findings and surgical outcomes can be predicted using this classification. Lymph node and intrahepatic metastases, and a curative resection are important prognostic factors in ICC; however, lymph node dissection is still controversial. In particular, the intraductal growth type and periductal infiltrating type of ICC without hilar invasion have favorable surgical outcomes, whereas the mass-forming type and periductal infiltrating type of ICC with hilar invasion have high hepatic recurrence and local recurrence, respectively. Multimodal treatments are therefore needed to improve the surgical outcomes of ICC.
To identify the pioneers of right anatomical hepatectomy (RAH), and clarify the development of associated operative procedures, concepts, and the future, we reviewed the “hidden” literature published ...in Eastern and Western countries since the 1940s. We searched the English and non-English literature on RAH through web search engines, text books and documents, and also referred to experts’ comments. Non-English literature, other than in Japanese, was translated. Changes in the anatomical concept, anatomical identification, vascular control technique, approaches, pre-operative management, and other aspects of RAH were analyzed. Honjo and Lortat-Jacob, in 1949 and 1951, respectively, reported the first cases of successful RAH; since then, RAH has been used in the treatment of liver malignancies worldwide. Vascular in-flow control is divided into intrafascial, extrafascial or transfissual access. The anatomical border along the main hepatic veins was proposed for transection, and anterior approaches have been suggested as alternative options in the hazardous situation of right liver rotation. In the laparoscopic era, several procedures and positions have been devised for RAH. In summary, RAH and related anatomical hepatectomy have been established as treatment methods for 70 years, and the future of RAH includes new concepts, approaches, and techniques to optimize patient safety and disease curability.
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