Incisional cyclic steps of permanent form in mixed bedrock-alluvial rivers

Most bedrock river channels have a relatively thin, discontinuous cover of alluvium and are thus termed mixed bedrock-alluvial channels. Such channels often show a series of steps formed at relatively regular intervals. This bed form is the bedrock equivalent of cyclic steps formed on beds composed of cohesive soil in gullies. In this paper, we perform a full nonlinear analysis for the case of cyclic steps in mixed bedrock-alluvial channels to explain the formation of these steps. We employ the shallow water equations in conjunction with equations describing the process of bedrock incision. As a model of bedrock incision, we employ the recently introduced Macro-Roughness Saltation Abrasion Alluviation model, which allows direct interaction between alluvial and bedrock morphodynamics. The analysis is greatly simplified by making the quasi-steady assumption that alluvial processes occur much faster than bedrock erosional processes. From our analysis, we obtain the conditions for the formation of cyclic steps in bedrock, as well as the longitudinal profiles of bed elevation, water surface elevation, and areal fraction of alluvial cover. It is found from the analysis that when the sediment supply is small relative to the transport capacity, cyclic steps form only on slopes with very high gradients. The analysis indicates that the shape of a step formed on bedrock is characterized by a relatively short upstream portion with an adverse slope and a long, almost planar downstream portion with a constant slope

Three-dimensional tissue model in direct contact with an on-chip vascular bed enabled by removable membranes

Three-dimensional (3D) tissue culture is a powerful tool for understanding physiological events. However, 3D tissues still have limitations in their size, culture period, and maturity, which are caused by the lack of nutrients and oxygen supply through the vasculature. Here, we propose a new method for culturing a 3D tissue--a spheroid--directly on an ‘on-chip vascular bed’. The method can be applied to any 3D tissue because the vascular bed is preformed, so that angiogenic factors from the tissue are not necessary to induce vasculature. The essential component of the assay system is the removable membrane that initially separates the 3D tissue culture well and the microchannel in which a uniform vascular bed is formed, and then allows the tissue to be settled directly onto the vascular bed following its removal. This in vitro system offers a new technique for evaluating the effects of vasculature on 3D tissues

Achievement of Target Blood Pressure Levels among Japanese Workers with Hypertension and Healthy Lifestyle Characteristics Associated with Therapeutic Failure

<div><p>Background</p><p>Few studies have examined Japanese with regard to the achievement rates for target blood pressure levels, or the relationship between these rates and healthy lifestyle characteristics in patients with hypertension as defined by the newly established hypertension management guidelines (JSH2014). The aim of this study was to elucidate achievement rates and examine healthy lifestyle characteristics associated with achievement status among Japanese.</p><p>Methods</p><p>This cross-sectional study, conducted in January-December 2012, examined blood pressure control and healthy lifestyle characteristics in 8,001 Japanese workers with hypertension (mean age, 57.0 years; 78.8% were men) who participated in a workplace health checkup. Data were collected from workplace medical checkup records and participants’ self-administered questionnaires. We divided into 5 groups [G1; young, middle-aged, and early-phase elderly patients (65–74 years old) without diabetes mellitus or chronic kidney disease (CKD) (<140/90 mmHg), G2; late-phase elderly patients (≥75 years old) without diabetes mellitus or CKD (<150/90 mmHg), G3; diabetic patients (<130/80 mmHg), G4; patients with CKD (<130/80 mmHg), and G5; patients with cerebrovascular and/or coronary artery diseases (<140/90 mmHg)] according to JSH2014. And then, achievement rates were calculated in each group. Multivariate analysis identified healthy lifestyle characteristics associated with “therapeutic failure” of target blood pressure.</p><p>Results</p><p>Target blood pressures were achieved by 60.2% of young, middle-aged, and early-phase elderly patients (G1), 71.4% of late-phase elderly patients (G2), 30.5% of diabetic patients (G3), 33.4% of those with chronic kidney disease (G4), and 66.0% of those with cerebrovascular and/or coronary artery diseases (G5). A body mass index of 18.5–24.9 and non-daily alcohol consumption were protective factors, and adequate sleep was found to contribute to therapeutic success.</p><p>Discussion</p><p>We found low achievement rates for treatment goals among patients with chronic kidney disease and diabetes mellitus. Maintaining an ideal body weight and adequate alcohol consumption may help with blood pressure control. Lifestyle modification may be necessary for better management of hypertension.</p></div

Distribution of internal medicine rotations among resident physicians in Japan: a nationwide, multicenter, cross-sectional study

Abstract Background In Japan, postgraduate clinical training encompasses a 2-year residency program, including at least 24 weeks of internal medicine (IM) rotations. However, the fragmented structure of these rotations can compromise the training’s quality and depth. For example, a resident might spend only a few weeks in cardiology before moving to endocrinology, without sufficient time to deepen their understanding or have clinical experience. This study examined current patterns and lengths of IM rotations within the Japanese postgraduate medical system. It scrutinized the piecemeal approach—whereby residents may engage in multiple short-term stints across various subspecialties without an overarching, integrated experience—and explored potential consequences for their clinical education. Methods This nationwide, multicenter, cross-sectional study used data from self-reported questionnaires completed by participants in the 2022 General Medicine In-Training Examination (GM-ITE). Data of 1,393 postgraduate year (PGY) one and two resident physicians who participated in the GM-ITE were included. We examined the IM rotation duration and number of IM subspecialties chosen by resident physicians during a 2-year rotation. Results Approximately half of the participants chose IM rotation periods of 32–40 weeks. A significant proportion of participants rotated in 5–7 internal medicine departments throughout the observation period. Notable variations in the distribution of rotations were observed, characterized by a common pattern where resident physicians typically spend 4 weeks in each department before moving to the next. This 4-week rotation is incrementally repeated across different subspecialties without a longer, continuous period in any single area. Notably, 39.7% of participants did not undertake general internal medicine rotations. These results suggest a narrowed exposure to medical conditions and patient care practices. Conclusions Our study highlights the need to address the fragmented structure of IM rotations in Japan. We suggest that short, specialized learning periods may limit the opportunity to gain broad in-depth knowledge and practical experience. To improve the efficacy of postgraduate clinical education, we recommend fostering more sustained and comprehensive learning experiences

Factors associated with therapeutic failure in young, middle-aged, and early-phase elderly patients without diabetes mellitus or chronic kidney disease (n = 5397) (logistic regression analysis).

<p>a) Odds ratio</p><p>b) 95% confidence interval</p><p>*<i>P</i><0.05</p><p>**<i>P</i><0.01.</p><p>Factors associated with therapeutic failure in young, middle-aged, and early-phase elderly patients without diabetes mellitus or chronic kidney disease (n = 5397) (logistic regression analysis).</p

Factors associated with therapeutic failure in patients with cerebrovascular and/or coronary artery disease (n = 409) (logistic regression analysis).

<p>a) Odds ratio</p><p>b) 95% confidence interval</p><p>*<i>P</i><0.05</p><p>**<i>P</i><0.01.</p><p>Factors associated with therapeutic failure in patients with cerebrovascular and/or coronary artery disease (n = 409) (logistic regression analysis).</p

Factors associated with therapeutic failure in failure in diabetes mellitus (n = 1,074) (logistic regression analysis).

<p>a) Odds ratio</p><p>b) 95% confidence interval</p><p>*<i>P</i><0.05</p><p>**<i>P</i><0.01.</p><p>Factors associated with therapeutic failure in failure in diabetes mellitus (n = 1,074) (logistic regression analysis).</p