Geometry-induced memory effects in isolated quantum systems: Observations and applications

Memory effects can lead to history-dependent behavior of a system, and they are ubiquitous in our daily life and have broad applications. Here we explore possibilities of generating memory effects in simple isolated quantum systems. By utilizing geometrical effects from a class of lattices supporting flat-bands consisting of localized states, memory effects could be observed in ultracold atoms in optical lattices. As the optical lattice continuously transforms from a triangular lattice into a kagome lattice with a flat band, history-dependent density distributions manifest quantum memory effects even in noninteracting systems, including fermionic as well as bosonic systems in the proper ranges of temperatures. Rapid growth in ultracold technology predicts a bright future for quantum memory-effect systems, and here two prototypical applications of geometry-induced quantum memory effects are proposed: An accelerometer recording the mechanical change rate in a coupled system and a rate-controlled memvalve where the rate of ramping the lattice potential acts as a control of the remnant density in the lattice.Comment: 13 pages, 11 figures, update figures and references. We provided one more application - quantum memory effects atomic memory (QMEAM

Tunable current circulation in triangular quantum-dot metastructures

Advances in fabrication and control of quantum dots allow the realization of metastructures that may exhibit novel electrical transport phenomena. Here, we investigate the electrical current passing through one such metastructure, a system composed of quantum dots placed at the vertices of a triangle. The wave natural of quantum particles leads to internal current circulation within the metastructure in the absence of any external magnetic field. We uncover the relation between its steady-state total current and the internal circulation. By calculating the electronic correlations in quantum transport exactly, we present phase diagrams showing where different types of current circulation can be found as a function of the correlation strength and the coupling between the quantum dots. Finally, we show that the regimes of current circulation can be further enhanced or reduced depending on the local spatial distribution of the interactions, suggesting a single-particle scattering mechanism is at play even in the strongly-correlated regime. We suggest experimental realizations of actual quantum-dot metastructures where our predictions can be directly tested.Comment: 5 pages, 4 figures, the Supplemental Information is attached at the en

Development and validation of the short-form Adolescent Health Promotion Scale.

BACKGROUND: Health-promoting lifestyle choices of adolescents are closely related to current and subsequent health status. However, parsimonious yet reliable and valid screening tools are scarce. The original 40-item adolescent health promotion (AHP) scale was developed by our research team and has been applied to measure adolescent health-promoting behaviors worldwide. The aim of our study was to examine the psychometric properties of a newly developed short-form version of the AHP (AHP-SF) including tests of its reliability and validity. METHODS: The study was conducted in nine middle and high schools in southern Taiwan. Participants were 814 adolescents randomly divided into two subgroups with equal size and homogeneity of baseline characteristics. The first subsample (calibration sample) was used to modify and shorten the factorial model while the second subsample (validation sample) was utilized to validate the result obtained from the first one. The psychometric testing of the AHP-SF included internal reliability of McDonald's omega and Cronbach's alpha, convergent validity, discriminant validity, and construct validity with confirmatory factor analysis (CFA). RESULTS: The results of the CFA supported a six-factor model and 21 items were retained in the AHP-SF with acceptable model fit. For the discriminant validity test, results indicated that adolescents with lower AHP-SF scores were more likely to be overweight or obese, skip breakfast, and spend more time watching TV and playing computer games. The AHP-SF also showed excellent internal consistency with a McDonald's omega of 0.904 (Cronbach's alpha 0.905) in the calibration group. CONCLUSION: The current findings suggest that the AHP-SF is a valid and reliable instrument for the evaluation of adolescent health-promoting behaviors. Primary health care providers and clinicians can use the AHP-SF to assess these behaviors and evaluate the outcome of health promotion programs in the adolescent population

Intra-abdominal abscess caused by toothpick injury

SummaryWe present the case of a 42-year-old female who presented to our emergency department (ED) complaining of epigastric pain for four days. She had been seen in the outpatient department and ED previously for evaluation, but continued to experience epigastric pain with fever. Emergency panendoscopy was performed and a toothpick was discovered impacted in the duodenal bulb. The gastroenterologist was unable to remove the toothpick endoscopically. Computed tomography of the abdomen revealed a long and straight hyperdense foreign body, and intra-abdominal abscess formation. An emergency laparotomy was performed. The patient recovered gradually and was discharged 11 days later. She could not remember when she swallowed the wooden toothpick, but guessed that it was while out drinking. There is an old wives’ tale in Taiwan that putting a toothpick in the cup while drinking beer reduces the likelihood of abdominal distention from the carbonation of the beer

Out-of-hospital Cardiac Arrest in the Elderly

SummaryBackgroundTo investigate the characteristics of out-of-hospital cardiac arrest (OHCA) in the elderly, we retrospectively studied a 6-month series of cases in an emergency department (ED) of a medical center in northern Taiwan.MethodsThere were 145 OHCA cases sent to our ED from January 1, 2007 to June 30, 2007. Of these, 28 traumarelated and five pediatric cases were excluded, and 112 cases were eventually enrolled into our study. The 112 cases were divided into an elderly group (≥ 65 years) of 81 cases and a non-elderly group of 31 cases. There were 64 males and 48 females (male/female ratio, 1.33:1) aged 24–99 years. We collected the laboratory data and made comparisons between the elderly and non-elderly group in arterial blood gas, hemoglobin, potassium, glucose, and troponin I. We used the statistical software SPSS version 11.5.0 (SPSS Inc., Chicago, IL, USA) with t test analysis. The clinical significance was set at p < 0.05.ResultsReturn of spontaneous circulation (ROSC) occurred in 46 cases (41%) after standard resuscitation by advanced cardiac life support. The elderly group had a higher ROSC rate than the non-elderly group, but this was not significant (44% vs. 32%; p = 0.335). The elderly group had less acidosis, less hypercapnia, less hyperkalemia, less hyperglycemia and a higher rate of elevated troponin I than the non-elderly group, but the differences were not significant. The elderly group had significantly lower hemoglobin levels than the non-elderly group (10.52 ± 3.04 vs. 12.6 ± 3.32g/dL; p = 0.003). The glucose levels of the ROSC group were significantly higher than the non-ROSC group in the elderly (230.14 ± 130.4 vs. 195.1 ± 147.7mg/dL; p = 0.049). In the group of acute coronary syndrome (ACS)-related OHCA, the ROSC rate in the elderly group was significantly higher than that of the non-elderly (54.2% vs. 40%; p = 0.014). The elderly group had a slightly lower rate of survival than the non-elderly group (7.4% vs. 9.7%; p = 0.159).ConclusionThe elderly OHCA cases had an anemic status. The elderly had a higher ROSC rate in cases with relative hyperglycemia and ACS-related OHCA. This finding provides us with the theory of trialing administration of glucose water during resuscitation in OHCA cases

Ruptured Aortic Aneurysm Presenting as a Stridor

SummaryStridor is an abnormal, high-pitched, whining breathing sound caused by a blockage in the throat or larynx that is usually heard in children. We describe an unusual case of an 81-year-old man brought to our emergency department with sudden onset of dyspnea and shortness of breath. Stridor could be heard without a stethoscope. We found a huge mass over the left upper chest on chest radiography, suggesting an aortic aneurysm. We believed that these symptoms were caused by a huge thoracic aortic aneurysm with trachea/bronchi compression. Chest computed tomography confirmed the diagnosis