Proposal for observing Yang-Lee criticality in Rydberg atomic arrays

Yang-Lee edge singularities (YLES) are the edges of the partition function zeros of an interacting spin model in the space of complex control parameters. They play an important role in understanding non-Hermitian phase transitions in many-body physics, as well as characterizing the corresponding non-unitary criticality.Even though such partition function zeroes have been measured in dynamical experiments where time acts as the imaginary control field, experimentally demonstrating such YLES criticality with a physical imaginary field has remained elusive due to the difficulty of physically realizing non-Hermitian many-body models. We provide a protocol for observing the YLES by detecting kinked dynamical magnetization responses due to broken PT symmetry, thus enabling the physical probing of non-unitary phase transitions in non-equilibrium settings. In particular, scaling analyses based on our non-unitary time evolution circuit with matrix product states (tMPS) accurately recover the exponents uniquely associated with the corresponding non-unitary CFT. We provide an explicit proposal for observing YLES criticality in Floquet quenched Rydberg atomic arrays with laser-induced loss, which paves the way towards an universal platform for simulating non-Hermitian many-body dynamical phenomena.Comment: 19 pages, 11 figure

Slipped Capital Femoral Epiphysis as a Complication of Growth Hormone Therapy

Slipped capital femoral epiphysis (SCFE) is a rare complication of growth hormone (GH) therapy. Here, we report three patients who developed SCFE during GH therapy. The first two patients had hypopituitarism and had started GH therapy at the age of 15 years 6 months and 13 years 9 months, respectively. SCFE developed 4 years and 1 year after GH therapy, respectively. The third patient had Prader-Willi syndrome with obesity and hypogonadism and began GH therapy at the age of 12 years and 11 months. SCFE developed 2 months after starting GH therapy. Pain over the hip joints or over the knees is an early sign of SCFE. Despite recommendation, none of the three patients continued GH therapy. A high index of suspicion during GH therapy in patients at high risk of SCFE is important for early diagnosis and appropriate management. [J Formos Med Assoc 2007;106(2 Suppl):S46-S50

Highly efficient mode-locked and Q-switched Er3+-doped fiber lasers using a gold nanorod saturable absorber

Mode-locked and Q-switched pulsed fiber laser sources with wavelengths of 1.55 mu m are widely used in various fields. Gold nanorods (GNRs) have been applied in biomedicine and optics owing to their biocompatibility, easy fabrication, and unique optical properties. This paper presents the analysis of a saturable absorber based on a colloidal gold nanorod (GNR) thin film for dual-function passively mode-locked and Q-switched 1.55-mu m fiber lasers. The colloidal GNR thin film possesses superior properties such as a wide operating wavelength range, large nonlinear absorption coefficient, and a picosecond-order recovery time. Its modulation depth and saturation intensity at 1.55 mu m are 7.8% and 6.55 MW/cm(2), respectively. Passive mode-locked or Q-switched laser operation is achieved by changing the number of GNR thin-film layers. The advantages of these high-quality GNRs in mode-locked and Q-switched fiber lasers with record-high slope efficiency are verified by conducting comprehensive material and laser dynamic analyses. The self-starting mode-locked fiber laser with an efficiency as high as 24.91% and passively Q-switched fiber laser with the maximum energy of 0.403 mu J are successfully demonstrated. This paper presents the novel demonstration of reconfigurable mode-locked and Q-switched all-fiber lasers by incorporating colloidal GNR thin films

Estimating quality weights for EQ-5D (EuroQol-5 dimensions) health states with the time trade-off method in Taiwan

Background/PurposeEQ-5D (EuroQol-5 dimensions) is a preference-based measure of health, which is widely used in cost–utility analyses. It has been suggested that each country should develop its own value set. We therefore sought to develop the quality weights of the EQ-5D health states with the time trade-off (TTO) method in Taiwan.MethodsA total of 745 respondents consisting of employees and volunteers in 17 different hospitals were recruited and interviewed. Each of them valued 13 of 73 EQ-5D health states using the TTO method. Based on the three exclusion criteria for valuation data, only 456 (61.21%) respondents were considered eligible for data analysis. The quality weights for all EQ-5D health states were modeled by generalized estimating equations (GEEs).ResultsOver half of the responses were given negative values, and the medical personnel seemed to have a significantly higher TTO value (+0.1) than others after controlling for other predictors. The N3 model (level 3 occurred within at least 1 dimension) yielded an acceptable fit for the observed OTT data [mean absolute error (MAE) = 0.056, R2 = 0.35]. The magnitude of mean absolute differences (MADs) between Taiwan data and those from the UK, Japan, and South Korea ranged from 0.146 to 0.592, but the rank correlation coefficients were all above 0.811.ConclusionThis study reaffirms the differences in health-related preference values across countries. The high proportion of negative values might indicate that we have also partially measured the intensity of fear in addition to the utility of different health states

Microfluidic label-free selection of mesenchymal stem cell subpopulation during culture expansion extends the chondrogenic potential

Mesenchymal stem cells (MSCs) have been shown as potential candidates for cell-based therapies for a diverse range of tissue regenerative applications. Therapeutic use of MSCs usually requires culture expansion, which increases the heterogeneity of MSCs in vitro, thus affecting the potency of the MSCs for more specific indications. The capacity for identifying and isolating special subsets of MSCs for treatment of specific diseases therefore holds great clinical significance. An important therapeutic application of MSC is for the regeneration of cartilage tissue. We and others have previously developed label-free microfluidic means to isolate subpopulations of culture expanded MSCs based on distinct biophysical characteristics. Here we utilize a spiral micro-channel device to separate culture expanded MSCs into five subgroups according to cell size, and study their proliferation and chondrogenesis at early, middle and late passages. Results show that in all passages, the medium-size subpopulation (cell size of 17-21 μm), compared to other subpopulations, displays significantly higher proliferation rate and chondrogenic capacity in terms of cartilage extracellular matrix formation. Also, the small cell subpopulation (average cell size of 11-12 μm) shows lower viability, and large cell subpopulation (average cell size 23-25 μm) expresses higher level of senescence-associated β-galactosidase. Finally, we show that repeated microfluidic exclusion of MSCs larger than 21 μm and smaller than 17 μm at every passage during continuous culture expansion result in selected MSCs with faster proliferation and better chondrogenic potential as compared to MSC derived from conventional expansion approach. This study demonstrates the significant merit and utility of size-based cell selection for the application of MSCs in cartilage regeneration

Experimental observation of Berry phases in optical Möbius-strip microcavities

The Möbius strip, a fascinating loop structure with one-sided topology, provides a rich playground for manipulating the non-trivial topological behaviour of spinning particles, such as electrons, polaritons and photons, in both real and parameter spaces. For photons resonating in a Möbius-strip cavity, the occurrence of an extra phase—known as the Berry phase—with purely topological origin is expected due to its non-trivial evolution in parameter space. However, despite numerous theoretical investigations, characterizing the optical Berry phase in a Möbius-strip cavity has remained elusive. Here we report the experimental observation of the Berry phase generated in optical Möbius-strip microcavities. In contrast to theoretical predictions in optical, electronic and magnetic Möbius-topology systems where only Berry phase π occurs, we demonstrate that a variable Berry phase smaller than π can be acquired by generating elliptical polarization of resonating light. Möbius-strip microcavities as integrable and Berry-phase-programmable optical systems are of great interest in topological physics and emerging classical or quantum photonic applications

Prognosis of ductal adenocarcinoma of pancreatic head with overexpression of CD44

SummaryBackgroundThe long-term survival rate of patients with pancreatic ductal adenocarcinoma (PDAC) is very low. Cancer stem cells have been identified in PDAC based on the expression of the surface markers CD24, CD44, CD133, and epithelial specific antigen. The prognosis of PDAC may be related to the presence or absence of tumor cells with cancer stem cell surface markers.MethodsEighty-six PDAC patients (51 male and 35 female patients) who underwent surgical treatment at Chang Gung Memorial Hospital—Lin-Kou Medical Center, Lin-Kou, Taiwan between 1998 and 2007 were included in this study. The patients' ages ranged from 30 years to 84 years. All their surgical specimens showed invasive ductal cancer. Immunohistochemical staining with CD44 antibodies was performed. The differences in clinical data, cell types of tumors, tumor staging, and survival rates between patients with CD44− (Group A; n = 33) and CD44+ (Group B; n = 53) were compared.ResultsClinical data, cell types of tumors, and tumor staging between the two groups showed no significant differences. The 3- and 5-year survival rates were, respectively, 51.5% and 19.8% in patients with CD44− tumor cells and 4.0% and 2.0% in those with CD44+ tumor cells. The differences were statistically significant (p < 0.0001). The median overall survival times of the two groups were also different (36.9 months vs. 12.2 months, p < 0.0001). Multivariate analysis showed that the CD44 as well as lymph node status, and differentiation of tumor cells were prognostic factors for patients with PDAC.ConclusionThe results suggested that CD44 expression in patients with PDAC after surgery was significantly associated with decreased survival, whereas patients with CD44− tumor cells survived significantly longer

Cost-effectiveness analysis of left atrial appendage occlusion compared with pharmacological strategies for stroke prevention in atrial fibrillation

Background Transcatheter left atrial appendage occlusion (LAAO) is a promising therapy for stroke prophylaxis in non-valvular atrial fibrillation (NVAF) but its cost-effectiveness remains understudied. This study evaluated the cost- effectiveness of LAAO for stroke prophylaxis in NVAF. Methods A Markov decision analytic model was used to compare the cost-effectiveness of LAAO with 7 pharmacological strategies: aspirin alone, clopidogrel plus aspirin, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban. Outcome measures included quality-adjusted life years (QALYs), lifetime costs and incremental cost-effectiveness ratios (ICERs). Base-case data were derived from ACTIVE, RE-LY, ARISTOTLE, ROCKET-AF, PROTECT-AF and PREVAIL trials. One- way sensitivity analysis varied by CHADS2 score, HAS-BLED score, time horizons, and LAAO costs; and probabilistic sensitivity analysis using 10,000 Monte Carlo simulations was conducted to assess parameter uncertainty. Results LAAO was considered cost-effective compared with aspirin, clopidogrel plus aspirin, and warfarin, with ICER of US$5,115,$2,447, and $6,298 per QALY gained, respectively. LAAO was dominant (i.e. less costly but more effective) compared to other strategies. Sensitivity analysis demonstrated favorable ICERs of LAAO against other strategies in varied CHADS2 score, HAS-BLED score, time horizons (5 to 15 years) and LAAO costs. LAAO was cost-effective in 86.24$50,000/QALY. Conclusions Transcatheter LAAO is cost-effective for prevention of stroke in NVAF compared with 7 pharmacological strategies. Condensed abstract The transcatheter left atrial appendage occlusion (LAAO) is considered cost-effective against the standard 7 oral pharmacological strategies including acetylsalicylic acid (ASA) alone, clopidogrel plus ASA, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban for stroke prophylaxis in non-valvular atrial fibrillation management