Nucleosynthesis of Light and Heavy Elements in Baryon-Rich Outflows Associated with Gamma-Ray Bursts

Gamma-ray bursts (GRBs) must originate from low baryon load, ultrarelativistic outflows; however, slower, more baryon-rich outflows (BROs) should also arise in connection with GRBs as ``circum-jet winds'' and/or ``failed GRBs''. We study the possibility of nucleosynthesis within such BROs by conducting detailed reaction network calculations in the framework of the fireball model, showing that they can be interesting sites for synthesis of heavy neutron capture elements, as well as of light elements such as deuterium. These products may be observable in the companion stars of black hole binary systems or in extremely metal-poor stars, offering an interesting probe of conditions in the central engine.Comment: 5 pages, 2 figures, slightly modified version of article to be published in Proc. of "GRBs in the Afterglow Era: 3rd Workshop (Rome 2002)

Bicuspid aortic valves undergo excessive strain during opening: A simulation study

ObjectiveThe objective of this study was to examine the influence of the morphologic characteristics of the bicuspid aortic valve on its disease progression by comparing the motion, stress/strain distribution, and blood flow of normal and stenotic tricuspid valves using simulation models.MethodsBicuspid, stenotic tricuspid with commissural fusion or thickened leaflet, and normal aortic valves were modeled with internal blood flow. Blood flow and the motion of aortic valve leaflets were studied using fluid–structure interaction finite element analysis, and stress/strain (curvature) distributions were calculated during the cardiac cycle. To mimic disease progression, we modified the local thickness of the leaflet where the bending stress was above a threshold.ResultsTransvalvular pressure gradient was greater in the bicuspid valve compared with the stenotic tricuspid valve with a similar valvular area. The bending strain (curvature) increased in both stenotic tricuspid and bicuspid valves, but a greater increase was observed in the bicuspid valve, and this was concentrated on the midline of the fused leaflets. During disease progression analysis, severity of the stenosis increased only in the bicuspid aortic valve model in terms of valvular area and pressure gradient.ConclusionsThe characteristic morphology of the bicuspid valve creates excessive bending strain on the leaflets during ventricular ejection. Such mechanical stress may be responsible for the rapid progression of this disease

Comparison of Psychological Distress between Type 2 Diabetes Patients with and without Proteinuria

We investigated the link between proteinuria and psychological distress among patients with type 2 diabetes mellitus (T2DM). A total of 130 patients with T2DM aged 69.1±10.3 years were enrolled in this cross-sectional study. Urine and blood parameters, age, height, body weight, and medications were analyzed, and each patient’s psychological distress was measured using the six-item Kessler Psychological Distress Scale (K6). We compared the K6 scores between the patients with and without proteinuria. Forty-two patients (32.3%) had proteinuria (≥±) and the level of HbA1c was 7.5±1.3%. The K6 scores of the patients with proteinuria were significantly higher than those of the patients without proteinuria even after adjusting for age and sex. The clinical impact of proteinuria rather than age, sex and HbA1c was demonstrated by a multiple regression analysis. Proteinuria was closely associated with higher psychological distress. Preventing and improving proteinuria may reduce psychological distress in patients with T2DM

Nucleosynthesis in Baryon-Rich Outflows Associated With Gamma-Ray Bursts

Robust generation of gamma-ray bursts (GRBs) implies the formation of outflows with very low baryon loads and highly relativistic velocities, but more baryon-rich, slower outflows are also likely to occur in most GRB central engine scenarios, either as ``circum-jet winds'' or ``failed GRBs''. Here we study the possibility of nucleosynthesis within such baryon-rich outflows by conducting detailed reaction network calculations in the framework of the basic fireball model. It is shown that high baryon load fireballs attaining mildly relativistic velocities can synthesize appreciable quantities of heavy neutron capture elements with masses up to the platinum peak and beyond. Small but interesting amounts of light elements such as deuterium and boron can also be produced. Depending on the neutron excess and baryon load, the combination of high entropy, rapid initial expansion and gradual expansion at later times can cause the reaction flow to reach the fission regime, and its path can be intermediate between those of the $r$- and $s$-processes (``$n$-process''). The nucleosynthetic signature of these outflows may be observable in the companion stars of black hole binary systems and in the most metal-poor stars, potentially offering an important probe of the inner conditions of the GRB source. Contribution to the solar abundances for some heavy elements may also be possible. The prospects for further developments in various directions are discussed.Comment: ApJ, in press; 11 pages, 3 figure

Questionnaire survey on communication infrastructures and personal disaster prevention in Niigata prefecture

近年、ブロードバンドや地上波デジタル放送といった情報通信インフラの発展が顕著である。しかし、新潟県の中山間地域では、過疎化・高齢化のため、これらの恩恵を受けないあるいはあっても有効に活用することができないといったデジタルディバイドの現象が生じている。ここでは、情報通信インフラと災害について、新潟県の一般家庭について調査した結果をまとめた

Current Status of Coronary Artery Surgery in Japan

The incidence of coronary artery disease in Japan is relatively low compared to that in western countries. The epidemiologic status of coronary artery diseases in our country was discussed. The selective cine coronary arteriography in 230 patients with chest pain, as well as clinical diagnosis and electrocardiographic findings were reviewed in order to study the surgical pictures of coronary artery disease among Japanese. A current review or aortocoronary bypass in Japan is introduced together with our own experiences. In western countries coronary artery surgery has rapidly become one of the most common heart operations. In Japan, on the contrary, our survey indicates that coronary artery surgery is less than 1%. Therefore, we would like to speculate the present status of coronary artery surgery in Japan in order to compare the situation between these countries

Endometrial Cancer as a Familial Tumor: Pathology and Molecular Carcinogenesis (Review)

Some cases of endometrial cancer are associated with a familial tumor and are referred to as hereditary nonpolyposis colorectal cancer (HNPCC or Lynch syndrome). Such tumors are thought to be induced by germline mutation of the DNA mismatch repair (MMR) gene, but many aspects of the pathology of familial endometrial cancer are unclear and no effective screening method has been established. However, the pathology of endometrial cancer with familial tumor has been progressively clarified in recent studies. At present, about 0.5% of all cases of endometrial cancers meet the clinical diagnostic criteria for HNPCC. A recent analysis of the three MMR genes (hMLH1, hMSH2 and hMSH6) revealed germline mutations in 18 of 120 cases (15.0%) of endometrial cancer with familial accumulation of cancer or double cancer, with a frameshift mutation of the hMSH6 gene being the most common. Many cases with mutation did not meet the current clinical diagnostic criteria for HNPCC, indicating that familial endometrial cancer is often not diagnosed as HNPCC. The results suggest that the hMSH6 gene mutation may be important in carcinogenesis in endometrial cancer and germline mutations of the MMR gene may be more prevalent in cases associated with familial accumulation of cancer. An international large-scale muticenter study is required to obtain further information about the pathology of endometrial cancer as a familial tumor