A penalized Cox proportional hazards model with multiple time-varying exposures

In recent pharmacoepidemiology research, the increasing use of electronic medication dispensing data provides an unprecedented opportunity to examine various health outcomes associated with long-term medication usage. Often, patients may take multiple types of medications intended for the same medical condition and the medication exposure status and intensity may vary over time, posing challenges to the statistical modeling of such data. In this article, we propose a penalized Cox proportional hazards (PH) model with multiple functional covariates and potential interaction effects. We also consider constrained coefficient functions to ensure a diminishing medication effect over time. Hypothesis testing of interaction effect and main effect was discussed under the penalized Cox PH model setting. Our simulation studies demonstrate the adequate performance of the proposed methods for both parameter estimation and hypothesis testing. Application to a primary care depression cohort study was also illustrated to examine the effects of two common types of antidepressants on the risk of coronary artery disease

Predictive role of blood-based indicators in neuromyelitis optica spectrum disorders

IntroductionThis study aimed to assess the predictive role of blood markers in neuromyelitis optica spectrum disorders (NMOSD).MethodsData from patients with NMOSD, multiple sclerosis (MS), and healthy individuals were retrospectively collected in a 1:1:1 ratio. The expanded disability status scale (EDSS) score was used to assess the severity of the NMOSD upon admission. Receiver operating characteristic (ROC) curve analysis was used to distinguish NMOSD patients from healthy individuals, and active NMOSD from remitting NMOSD patients. Binary logistic regression analysis was used to evaluate risk factors that could be used to predict disease recurrence. Finally, Wilcoxon signed-rank test or matched-sample t-test was used to analyze the differences between the indicators in the remission and active phases in the same NMOSD patient.ResultsAmong the 54 NMOSD patients, neutrophil count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) (platelet × NLR) were significantly higher than those of MS patients and healthy individuals and positively correlated with the EDSS score of NMOSD patients at admission. PLR can be used to simultaneously distinguish between NMOSD patients in the active and remission phase. Eleven (20.4%) of the 54 patients had recurrence within 12 months. We found that monocyte-to-lymphocyte ratio (MLR) (AUC = 0.76, cut-off value = 0.34) could effectively predict NMOSD recurrence. Binary logistic regression analysis showed that a higher MLR at first admission was the only risk factor for recurrence (p = 0.027; OR = 1.173; 95% CI = 1.018–1.351). In patients in the relapsing phase, no significant changes in monocyte and lymphocyte count was observed from the first admission, whereas patients in remission had significantly higher levels than when they were first admitted.ConclusionHigh PLR is a characteristic marker of active NMOSD, while high MLR is a risk factor for disease recurrence. These inexpensive indicators should be widely used in the diagnosis, prognosis, and judgment of treatment efficacy in NMOSD

The Micro-Changes of Fly Ash in the Utilization of “Dip in One Acid Twice/Unite Two Kinds of Alkalis”

Determined the new technology of element leaching in fly ash’s utilization---- “dip in one acid twice/unite two kinds of alkalis” through comparison tests, the technique consist of four phases: acid leaching、alkali dissolution, calcination and second acid leaching, the maximum fine utilization rates of silicon, aluminum, iron are respectively 97.07%, 86.67%, 96.54%, the total utilization rate is 100%. Analyzed the micro-changes of fly ash in the utilization process by X-ray diffraction and scanning electron microscope, the results show that: (1)there are mineral changes exist in acid leaching process, and some amorphous active substance is dissolved, it destroy the surface structure of fly ash, conducive to the conduct of following response; (2)after alkali leaching, most of the amorphous SiO2 is dissolved, crystalline SiO2 (quartz) has not changed; (3)after calcination with sodium carbonate, all the mine phases are transformed into nepheline and a small amount of pyroxene which are layer (film) structure , except a small amount of residual quartz crystal;(4)after the second acid leaching, the fly ash is transformed into silica II which mainly constitute by the amorphous SiO2.特集 : 「資源、新エネルギー、環境、防災研究国際セミナー

Glassy carbon electrode modified with 7,7,8,8-tetracyanoquinodimethane and graphene oxide triggered a synergistic effect: low-potential amperometric detection of reduced glutathione.

A sensitive electrochemical sensor based on the synergistic effect of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and graphene oxide (GO) for low-potential amperometric detection of reduced glutathione (GSH) in pH 7.2 phosphate buffer solution (PBS) has been reported. This is the first time that the combination of GO and TCNQ have been successfully employed to construct an electrochemical sensor for the detection of glutathione. The surface of the glassy carbon electrode (GCE) was modified by a drop casting using TCNQ and GO. Cyclic voltammetric measurements showed that TCNQ and GO triggered a synergistic effect and exhibited an unexpected electrocatalytic activity towards GSH oxidation, compared to GCE modified with only GO, TCNQ or TCNQ/electrochemically reduced GO. Three oxidation waves for GSH were found at −0.05, 0.1 and 0.5 V, respectively. Amperometric techniques were employed to detect GSH sensitively using a GCE modified with TCNQ/GO at −0.05 V. The electrochemical sensor showed a wide linear range from 0.25 to 124.3 μM and 124.3 μM to 1.67 mM with a limit of detection of 0.15 μM. The electroanalytical sensor was successfully applied towards the detection of GSH in an eye drop solution

Security Analysis of RAPP An RFID Authentication Protocol based on Permutation

One of the key problems in Radio Frequency Identification(RFID) is security and privacy. Many RFID authentication protocols have been proposed to preserve security and privacy of the system. Nevertheless, most of these protocols are analyzed and it is shown that they can not provide security against some RFID attacks. RAPP is a new ultralightweight authentication protocol with permutation. In RAPP, only three operations are involved: bitwise XOR, left rotation and permutation. In this paper, we give an active attack on RAPP. We first collect some authentication messages through impersonating valid tag and readers; Then we forge valid reader to communicate with the tag about times. Using the property of the left rotation and permutation operation, we can deduce the relationship of bits of random number or secret keys at different positions, thus obtain all the secret shared by the reader and the tag