22 research outputs found

    Common Correlated Effects Estimation of Nonlinear Panel Data Models

    Full text link
    This paper focuses on estimating the coefficients and average partial effects of observed regressors in nonlinear panel data models with interactive fixed effects, using the common correlated effects (CCE) framework. The proposed two-step estimation method involves applying principal component analysis to estimate latent factors based on cross-sectional averages of the regressors in the first step, and jointly estimating the coefficients of the regressors and factor loadings in the second step. The asymptotic distributions of the proposed estimators are derived under general conditions, assuming that the number of time-series observations is comparable to the number of cross-sectional observations. To correct for asymptotic biases of the estimators, we introduce both analytical and split-panel jackknife methods, and confirm their good performance in finite samples using Monte Carlo simulations. An empirical application utilizes the proposed method to study the arbitrage behaviour of nonfinancial firms across different security markets

    Solenoid-free current drive via ECRH in EXL-50 spherical torus plasmas

    Full text link
    As a new spherical tokamak (ST) designed to simplify engineering requirements of a possible future fusion power source, the EXL-50 experiment features a low aspect ratio (A) vacuum vessel (VV), encircling a central post assembly containing the toroidal field coil conductors without a central solenoid. Multiple electron cyclotron resonance heating (ECRH) resonances are located within the VV to improve current drive effectiveness. Copious energetic electrons are produced and measured with hard X-ray detectors, carry the bulk of the plasma current ranging from 50kA to 150kA, which is maintained for more than 1s duration. It is observed that over one Ampere current can be maintained per Watt of ECRH power issued from the 28-GHz gyrotrons. The plasma current reaches Ip>80kA for high density (>5e18me-2) discharge with 150kW ECHR heating. An analysis was carried out combining reconstructed multi-fluid equilibrium, guiding-center orbits of energetic electrons, and resonant heating mechanisms. It is verified that in EXL-50 a broadly distributed current of energetic electrons creates smaller closed magnetic-flux surfaces of low aspect ratio that in turn confine the thermal plasma electrons and ions and participate in maintaining the equilibrium force-balance

    Generating Aptamers by Cell-SELEX for Applications in Molecular Medicine

    Get PDF
    Aptamers are single-stranded oligonucleotides of DNA or RNA that bind to target molecules with high affinity and specificity. Typically, aptamers are generated by an iterative selection process, called systematic evolution of ligands by exponential enrichment (SELEX). Recent advancements in SELEX technology have extended aptamer selection from comparatively simple mixtures of purified proteins to whole living cells, and now cell-based SELEX (or cell-SELEX) can isolate aptamers that bind to specific target cells. Combined with nanotechnology, microchips, microfluidic devices, RNAi and other advanced technologies, cell-SELEX represents an integrated platform providing ultrasensitive and highly specific tools for clinical medicine. In this review, we describe the recent progress made in the application of cell-SELEX for diagnosis, therapy and biomarker discovery

    Prevalence and risk factors of elder abuse in survivors of stroke: A cross‐sectional study

    No full text
    Abstract Background and Aims The understanding of the prevalence and risk factors associated with elder abuse in stroke survivors is currently lacking. Therefore, the objective of this study is to ascertain the prevalence and potential risk factors of elder abuse in stroke survivors, while also examining its correlation with insomnia. Methods In this cross‐sectional study, a total of 485 stroke survivors aged 65 years and older, who received treatment at the Emergency department of Shunde Hospital, Southern Medical University, were subjected to face‐to‐face interviews using the questionnaire on elder abuse from the Third Survey on Chinese Women's Social Status. A logistic regression analysis was employed to examine the association between risk factors and elder abuse among stroke survivors. Results 62.27% of the participants reported experiencing elder abuse, with 14.85% of them indicating suffering from more than two subtypes of abuse. Factors such as residing in nursing homes, lower income, and smoking were found to increase the likelihood of experiencing elder abuse and all four subtypes of abuse. Additionally, advancing age was associated with a higher risk of experiencing all four subtypes of abuse, although it did not affect the occurrence of overall abuse. It is worth noting that the self‐reported prevalence of the four types of abuse by the elderly themselves was higher compared to the reports provided by caregivers. Conclusion Elder abuse is prevalent among stroke survivors, especially those who are residing in nursing homes, with lower income, and smokers. Elder abuse significantly increased the prevalence of insomnia in stroke survivors. Further research is needed to better explore effective measures to reduce the prevalence of elder abuse of stroke survivors

    Axion haloscope array with PT symmetry

    No full text
    We generalize the recently proposed PT-symmetric axion haloscope to a larger array with more PT-symmetric structures. By broadening the response bandwidth of the signal without increasing the readout noise, the optimized scan rate of the axion haloscope is significantly enhanced, as well as is the signal power. Furthermore, we show that the robustness of the detector towards the variations of the array coupling is the strongest when a binary tree structure is introduced which contains a largely enhanced PT symmetry. The multiple allowed probing sensors can further increase the scan rate by a factor of the sensors' number due to the correlation of the signals. This type of array can strongly boost the search for an axion compared to single-mode resonant detection. The enhancement to the scan rate becomes the most manifest when applied to the proposed detection using a superconducting radio-frequency cavity with an ac magnetic field where most of the parameter space of the QCD axion above kHz can be probed

    Hsa_Circ_0001275: A Potential Novel Diagnostic Biomarker for Postmenopausal Osteoporosis

    No full text
    Background/Aims: Circular RNAs (circRNAs) serve as potential diagnostic biomarkers. In this study, we aimed to identify a potential biomarker from peripheral blood mononuclear cells (PBMCs) of patients with postmenopausal osteoporosis (PMOP). Methods: CircRNA expression in PBMCs from three pairs of samples from PMOP patients and controls was initially detected by circRNA microarray. The changes in selected circRNAs in PBMCs from 28 PMOP patients and 21 age- and sex-matched controls were confirmed using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Next, samples from 30 PMOP patients and 20 controls were used for further verification. Pearson correlation test was performed to assess the correlation between circRNAs and clinical variables. The area under the receiver operator characteristic (ROC) curve was calculated to evaluate the diagnostic value. Results: Six differentially expressed circRNAs were identified by chip microarray analysis, of which only hsa_circ_0001275 showed consistency and statistical significance in qRT-PCR. The correlation analysis between age, body weight, height, WBC, lymphocyte and monocyte count, bone density, T-score, β-CROSSL, OSTEOC, and TP1NP showed that hsa_circ_0001275 was negatively correlated with T-score. ROC curves showed that hsa_circ_0001275 has significant diagnostic value in PMOP (AUC=0.759, P< 0.001). Conclusion: This study suggests that hsa_circ_0001275 may serve as a potential diagnostic biomarker for PMOP
    corecore