Higher-order effects on the incompressibility of isospin asymmetric nuclear matter

Analytical expressions for the saturation density as well as the binding energy and incompressibility at the saturation density of asymmetric nuclear matter are given exactly up to 4th-order in the isospin asymmetry delta =(rho_n - rho_p)/rho using 11 characteristic parameters defined at the normal nuclear density rho_0. Using an isospin- and momentum-dependent modified Gogny (MDI) interaction and the SHF approach with 63 popular Skyrme interactions, we have systematically studied the isospin dependence of the saturation properties of asymmetric nuclear matter, particularly the incompressibility $K_{sat}(\delta )=K_{0}+K_{sat,2}\delta ^{2}+K_{sat,4}\delta ^{4}+O(\delta ^{6})$ at the saturation density. Our results show that the magnitude of the high-order $K_{sat,4}$ parameter is generally small compared to that of the K_{\sat,2} parameter. The latter essentially characterizes the isospin dependence of the incompressibility at the saturation density and can be expressed as $K_{sat,2}=K_{sym}-6L-\frac{J_{0}}{K_{0}}L$, Furthermore, we have constructed a phenomenological modified Skyrme-like (MSL) model which can reasonably describe the general properties of symmetric nuclear matter and the symmetry energy predicted by both the MDI model and the SHF approach. The results indicate that the high-order $J_{0}$ contribution to $K_{sat,2}$ generally cannot be neglected. In addition, it is found that there exists a nicely linear correlation between $K_{sym}$ and $L$ as well as between $J_{0}/K_{0}$ and $K_{0}$. These correlations together with the empirical constraints on $K_{0}$, $L$, $E_{sym}(\rho_{0})$ and the nucleon effective mass lead to an estimate of $K_{sat,2}=-370\pm 120$ MeV.Comment: 61 pages, 12 figures, 6 Tables. Title changed a little and results of several Skyrme interactions updated. Accepted version to appear in PR

An appendix adenocarcinoma mimicking appendicitis

SummaryCancer of the appendix is very rare and is typically found incidentally in approximately 1% of patients who received appendectomies. Most of appendiceal tumors are carcinoid, adenoma, and lymphoma. Adenocarcinoma of the appendix accounts for only 10% of all primary appendiceal cancers and the treatment remains controversial. In this article, we report a 67-year-old man who presented with symptoms of appendicitis that was diagnosed as adenocarcinoma of the appendix Stage II. The patient was treated with right hemicolectomy. To date he remains asymptomatic

Development of a Piezoelectric Vacuum Sensing Component for a Wide Pressure Range

In this study, we develop a clamped-clamped beam-type piezoelectric vacuum pressure sensing element. The clamped-clamped piezoelectric beam is composed of a PZT layer and a copper substrate. A pair of electrodes is set near each end. An input voltage is applied to a pair of electrodes to vibrate the piezoelectric beam, and the output voltage is measured at the other pair. Because the viscous forces on the piezoelectric beam vary at different air pressures, the vibration of the beam depends on the vacuum pressure. The developed pressure sensor can sense a wide range of pressure, from 6.5 × 10(-6) to 760 Torr. The experimental results showed that the output voltage is inversely proportional to the gas damping ratio, and thus, the vacuum pressure was estimated from the output voltage

Prevalence and Associated Metabolic Factors of Gallstone Disease in the Elderly Agricultural and Fishing Population of Taiwan

Purpose. To evaluate sex-related differences in the prevalence of and cardiovascular risk factors related to gallstone disease (GSD) in an elderly agricultural and fishing population of Taipei, Taiwan. Methods. The study sample consisted of 6511 healthy elderly participants (3971 men and 2540 women) who were voluntarily admitted to a teaching hospital for a physical checkup in 2010. The participants’ blood samples and real-time ultrasound fatty liver results were collected. Results. The prevalence of GSD in the study population was 13.2%, which increased significantly with population age (P<.0001). Women were associated with significantly higher GSD prevalence than men (14.8% versus 12.2%; for the chi-square test, P=.003). In a multiple logistic regression analysis, female sex, older age, and metabolic syndrome (MetS) were significantly associated with GSD. Multiple logistic regression analysis also revealed that obesity (odds ratio OR=1.26, 95% confidence interval (CI): 1.09–1.44) and metabolic factors (one or 2 versus none, OR=1.48, 95% CI: 1.08–1.76) were significantly associated with GSD in women but not in men. Conclusion. In the study population, female sex, older age, and MetS were associated with higher GSD prevalence. The population exhibited other sex-related differences

The Impact of Individual Characteristics, Personality Traits, Perceived Risk on Young People's Intention to Participate in Overseas Working Holiday

AbstractThis paper analyzes whether individual characteristics, personality traits, and perceived risk will affect young people's intention to participate in overseas working holiday, and taking the three countries of Australia, the United States, and the United Kingdom as examples. The sample consists of young people and students at numerous universities and colleges, with ages ranging from 18 to 31. A total of 350 questionnaires were issued, and 204 valid questionnaires were recovered, with a return rate of 58.2%. Multiple regression was used to test hypotheses. The research results indicate that the factors influencing young people's intention to take working holiday in different countries were not entirely the same. It is found that age, work experience, neuroticism, extroversion, openness to experience, agreeableness, environmental and social risk, and agent and workplace risk may influence intention to participate in overseas working holiday. The research implications and recommendations are also presented