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Han X, Liu J, Wang B, Du A, Xu L, Wu B. Synthesis and chromatographic applications of polysiloxane-based stationary phase containing nitrogen heterocyclic system. J Chromatogr A 2018; 1578:76-82. [DOI: 10.1016/j.chroma.2018.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/27/2018] [Accepted: 10/09/2018] [Indexed: 11/26/2022]
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Li X, Liu J, Lu J, Zhou X. Moderate deviation for random elliptic PDE with small noise. ANN APPL PROBAB 2018. [DOI: 10.1214/17-aap1373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Xu H, Fang G, Chen Y, Liu J, Ying Z. Latent Class Analysis of Recurrent Events in Problem-Solving Items. APPLIED PSYCHOLOGICAL MEASUREMENT 2018; 42:478-498. [PMID: 30787489 PMCID: PMC6373852 DOI: 10.1177/0146621617748325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Computer-based assessment of complex problem-solving abilities is becoming more and more popular. In such an assessment, the entire problem-solving process of an examinee is recorded, providing detailed information about the individual, such as behavioral patterns, speed, and learning trajectory. The problem-solving processes are recorded in a computer log file which is a time-stamped documentation of events related to task completion. As opposed to cross-sectional response data from traditional tests, process data in log files are massive and irregularly structured, calling for effective exploratory data analysis methods. Motivated by a specific complex problem-solving item "Climate Control" in the 2012 Programme for International Student Assessment, the authors propose a latent class analysis approach to analyzing the events occurred in the problem-solving processes. The exploratory latent class analysis yields meaningful latent classes. Simulation studies are conducted to evaluate the proposed approach.
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Gu Y, Liu J, Xu G, Ying Z. Hypothesis Testing of the Q-matrix. PSYCHOMETRIKA 2018; 83:10.1007/s11336-018-9629-6. [PMID: 29998451 DOI: 10.1007/s11336-018-9629-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Indexed: 06/08/2023]
Abstract
The recent surge of interests in cognitive assessment has led to the development of cognitive diagnosis models. Central to many such models is a specification of the Q-matrix, which relates items to latent attributes that have natural interpretations. In practice, the Q-matrix is usually constructed subjectively by the test designers. This could lead to misspecification, which could result in lack of fit of the underlying statistical model. To test possible misspecification of the Q-matrix, traditional goodness of fit tests, such as the Chi-square test and the likelihood ratio test, may not be applied straightforwardly due to the large number of possible response patterns. To address this problem, this paper proposes a new statistical method to test the goodness fit of the Q-matrix, by constructing test statistics that measure the consistency between a provisional Q-matrix and the observed data for a general family of cognitive diagnosis models. Limiting distributions of the test statistics are derived under the null hypothesis that can be used for obtaining the test p-values. Simulation studies as well as a real data example are presented to demonstrate the usefulness of the proposed method.
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Li Y, Gu R, Zhu Q, Liu J. Changes of Spinal Edema and Expression of Aquaporin 4 in Methylprednisolone-treated Rats with Spinal Cord Injury. ANNALS OF CLINICAL AND LABORATORY SCIENCE 2018; 48:453-459. [PMID: 30143486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The aim of the current study was to investigate the impact of methylprednisolone (MP) on the expression of Aquaporin 4 (AQP4) and spinal edema in rats with acute spinal cord injury (ASCI). Sprague-Dawley (SD) Wistar rats were randomly divided into the following groups: control (C), sham operation (S), ASCI, and MP-treated. After the ASCI model was induced and prepared, 30 mg/kg MP was injected via the tail vein, on postoperative days 1, 3, and 7. The Tarlov scoring method was used to evaluate the neurological outcome; spinal water content was measured using the wet/dry weight method; spinal pathological changes were evaluated by hematoxylin-eosin (HE) staining, and the expression of AQP4 was detected using Western blot. Compared to the S group, the motor nerve functional score (MNFS) was significantly lower in the ASCI group. Furthermore, their spinal water content and AQP4 expression was also significantly higher (P<0.05). Moreover, compared with the ASCI group, the MNFS, spinal water content, and AQP4 expression of the MP group was significantly lower (P<0.05). The ASCI groups showed severe, perivascular and neuronal edema, a reduction in the neuron number, shrinkage of the nuclei, necrosis of some spinal tissue white matter degeneration, and the formation of numerous cysts and vacuoles. In the MP group, the spinal gray matter and white matter had much clearer borders, with reduced bleeding range and karyopyknosis. Furthermore, this group showed improved perivascular and neuronal edema and an even distribution of intranuclear chromatins. MP inhibited spinal edema in rats with ASCI, which might be related to the reduced AQP4 expression in spinal tissues.
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Xu K, Sun L, Liu J, Wang H. An empirical investigation of taxi driver response behavior to ride-hailing requests: A spatio-temporal perspective. PLoS One 2018; 13:e0198605. [PMID: 29883478 PMCID: PMC5993247 DOI: 10.1371/journal.pone.0198605] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 05/22/2018] [Indexed: 02/01/2023] Open
Abstract
Using data provided by a ride-hailing platform, this paper examines the factors that affect taxi driver response behavior to ride-hailing requests. The empirical investigation from a driver’s perspective is of great importance for ride-hailing service providers, given that approximately 40% of the hailing requests receive no response from any driver. To comprehensively understand taxi driver response behavior, we use a rich dataset to generate variables related to the spatio-temporal supply-demand intensities, the economic incentives, the requests’ and the drivers’ characteristics. The results show that drivers are more likely to respond to requests with economic incentives (especially a firm subsidy), and those with a lower spatio-temporal demand intensity or a higher spatio-temporal supply intensity. In addition, drivers are more likely to respond to requests involving rides covering a greater geographical distance and to those with a smaller number of repeated submissions. The drivers’ characteristics, namely, the number of requests received and the number of requests responded, however, have relatively little impacts on their response probability to the current request. Our findings contribute to the related literature and provide managerial implications for ride-hailing service providers.
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Alegria M, Drake RE, Kang HA, Metcalfe J, Liu J, DiMarzio K, Ali N. Simulations Test Impact Of Education, Employment, And Income Improvements On Minority Patients With Mental Illness. Health Aff (Millwood) 2018; 36:1024-1031. [PMID: 28583960 DOI: 10.1377/hlthaff.2017.0044] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Social determinants of health, such as poverty and minority background, severely disadvantage many people with mental disorders. A variety of innovative federal, state, and local programs have combined social services with mental health interventions. To explore the potential effects of such supports for addressing poverty and disadvantage on mental health outcomes, we simulated improvements in three social determinants-education, employment, and income. We used two large data sets: one from the National Institute of Mental Health that contained information about people with common mental disorders such as anxiety and depression, and another from the Social Security Administration that contained information about people who were disabled due to severe mental disorders such as schizophrenia and bipolar disorder. Our simulations showed that increasing employment was significantly correlated with improvements in mental health outcomes, while increasing education and income produced weak or nonsignificant correlations. In general, minority groups as well as the majority group of non-Latino whites improved in the desired outcomes. We recommend that health policy leaders, state and federal agencies, and insurers provide evidence-based employment services as a standard treatment for people with mental disorders.
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Abstract
The asymptotic efficiency of a generalized likelihood ratio test proposed by Cox is studied under the large deviations framework for error probabilities developed by Chernoff. In particular, two separate parametric families of hypotheses are considered (Cox, 1961, 1962). The significance level is set such that the maximal type I and type II error probabilities for the generalized likelihood ratio test decay exponentially fast with the same rate. We derive the analytic form of such a rate that is also known as the Chernoff index (Chernoff, 1952), a relative efficiency measure when there is no preference between the null and the alternative hypotheses. We further extend the analysis to approximate error probabilities when the two families are not completely separated. Discussions are provided concerning the implications of the present result on model selection.
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Li Y, Hu H, Liu J, Zhu Q, Gu R. Effects of aquaporin 4 and inward rectifier potassium channel 4.1 on medullospinal edema after methylprednisolone treatment to suppress acute spinal cord injury in rats. Acta Cir Bras 2018. [PMID: 29513816 DOI: 10.1590/s0102-865020180020000009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To investigate the effects of aquaporin 4 (AQP4) and inward rectifier potassium channel 4.1 (Kir4.1) on medullospinal edema after treatment with methylprednisolone (MP) to suppress acute spinal cord injury (ASCI) in rats. METHODS Sprague Dawley rats were randomly divided into control, sham, ASCI, and MP-treated ASCI groups. After the induction of ASCI, we injected 30 mg/kg MP via the tail vein at various time points. The Tarlov scoring method was applied to evaluate neurological symptoms, and the wet-dry weights method was applied to measure the water content of the spinal cord. RESULTS The motor function score of the ASCI group was significantly lower than that of the sham group, and the spinal water content was significantly increased. In addition, the levels of AQP4 and Kir4.1 were significantly increased, as was their degree of coexpression. Compared with that in the ASCI group, the motor function score and the water content were significantly increased in the MP group; in addition, the expression and coexpression of AQP4 and Kir4.1 were significantly reduced. CONCLUSION Methylprednisolone inhibited medullospinal edema in rats with acute spinal cord injury, possibly by reducing the coexpression of aquaporin 4 and Kir4.1 in medullospinal tissues.
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Abstract
In this paper we consider a one dimensional stochastic system described by an elliptic equation. A spatially varying random coefficient is introduced to account for uncertainty or imprecise measurements. We model the logarithm of this coefficient by a Gaussian process and provide asymptotic approximations of the tail probabilities of the derivative of the solution.
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Xue YP, Ji XY, Yang L, Liu HR, Sheng YJ, Dai XX, Xi YJ, Liu JC, Shi J, Xie T, Zhang YS, Ma JW, Dong J. [Experimental studies on correlation between nucleolus spindle-related protein 1 and the malignant progression and prognosis of human glioblastoma multiforme]. ZHONGHUA YI XUE ZA ZHI 2018; 98:340-345. [PMID: 29429243 DOI: 10.3760/cma.j.issn.0376-2491.2018.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the correlation between nucleolus spindle-related protein 1 (NUSAP1) and malignant progression and prognosis of human glioblastoma multiforme (GBM). Methods: RT-PCR and immunohistochemical technique were applied to analyze NUSAP1 expression level in GBM surgical specimens. Correlations between NUSAP1 expression and molecular classification and survival of patients with GBM were also investigated in TCGA database. The gene silencing technique was used to silence NUSAP1 expression in U87 cells, CCK-8 assay was used to detect cell proliferation, flow cytometry was used to detect cell cycle changes, and in vivo tumorigenicity was evaluated after NUSAP1 silencing in tumor-bearing mice. Results: NUSAP1 expression level in GBM was higher than that in non-tumor brain tissue. Survival curve analysis showed that the survival time of GBM patients with high NUSAP1 expression decreased significantly (P<0.01). NUSAP1 expression was relatively lower in mesenchymal and neural molecular subtypes of GBM, when compared with the other two molecular subtypes. And it was closely related with specific genetic aberrations (such as PTEN loss and IDH1 mutation). Silencing NUSAP1 inhibited G2/M cell cycle progression of GBM cells, and inhibited cell proliferation both in vitro and in vivo. Conclusion: Expression of NUSAP1 is closely related to progress and prognosis of GBM, and can be a biomarker reflecting GBM prognosis and act as a therapeutic target with potential clinical application value.
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Chen Y, Li X, Liu J, Ying Z. Recommendation System for Adaptive Learning. APPLIED PSYCHOLOGICAL MEASUREMENT 2018; 42:24-41. [PMID: 29335659 PMCID: PMC5766274 DOI: 10.1177/0146621617697959] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
An adaptive learning system aims at providing instruction tailored to the current status of a learner, differing from the traditional classroom experience. The latest advances in technology make adaptive learning possible, which has the potential to provide students with high-quality learning benefit at a low cost. A key component of an adaptive learning system is a recommendation system, which recommends the next material (video lectures, practices, and so on, on different skills) to the learner, based on the psychometric assessment results and possibly other individual characteristics. An important question then follows: How should recommendations be made? To answer this question, a mathematical framework is proposed that characterizes the recommendation process as a Markov decision problem, for which decisions are made based on the current knowledge of the learner and that of the learning materials. In particular, two plain vanilla systems are introduced, for which the optimal recommendation at each stage can be obtained analytically.
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Belay TA, Lin CY, Hsiao HM, Chang MF, Liu JC. Effect of precursor type on the reduction of concentrated nitrate using zero-valent copper and sodium borohydride. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2018; 77:114-122. [PMID: 29339610 DOI: 10.2166/wst.2017.525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this study, we demonstrated that the choice of precursor has a strong effect on the reduction of nitrate (NO3-) using zero-valent copper (Cu0) synthesized by sodium borohydride (NaBH4). Different precursors: CuSO4, CuO, Cu2O, Cu powder, and Cu mesh were used to reduce NO3- at 677 mg-N/L under the reducing conditions of NaBH4. Compared with the prehydrolyzed samples, those prepared without prehydrolysis exhibited lower reduction rates, longer times and higher concentrations of nitrite (NO2-) intermediate. It was found that one-time addition of NaBH4 resulted in higher reduction rate and less NO2- intermediate than two-step addition. Results showed that Cu0 from CuSO4 possessed the smallest particle size (890.9 nm), highest surface area (26.0 m2/g), and highest reaction rate (0.166 min-1). Values of pseudo-first-order constant (kobs) were in the order: CuSO4 > CuO > Cu2O > Cu powder >Cu mesh. However, values of surface area-normalized reaction rate (kSA) were approximately equal. It was proposed that NO3- was reduced to NO2- on Cu0, and then converted to NH4+ and N2, respectively; H2 generated from both NaBH4 hydration and Cu (II) reduction contributed to NO3- reduction as well.
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Cheng CY, Liu JC, Wang JJ, Li YH, Pan J, Zhang YR. Autophagy inhibition increased the anti-tumor effect of cisplatin on drug-resistant esophageal cancer cells. J BIOL REG HOMEOS AG 2017; 31:645-652. [PMID: 28954454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The sensitivity of tumor cells to treatment can be affected by autophagy. The drug resistance of esophageal cancer cells against cisplatin occurs during the long period of chemotherapy drug treatment. This study was designed to observe the effect autophagy has on the occurrence of esophageal cancer cell drug resistance against cisplatin and investigate its molecular mechanism in order to provide new details and strategies for the clinical treatment of esophageal cancer, especially cisplatin treatment. The detection methods used in this study were 3-(4,5-dimethylthiazd-2-yl)-2,5-dipheny-ltetrazolium bromide (MTT) colorimetric assay, clone survival technique, small interfering RNA (siRNA) transfection, and Western blot. Autophagy is a protection mechanism of drug-resistant cells processed by cisplatin, and maintains the cell clone survival ability. Autophagy activation requires the involvement of Atg5 and Atg7.
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An FP, Balantekin AB, Band HR, Bishai M, Blyth S, Cao D, Cao GF, Cao J, Chan YL, Chang JF, Chang Y, Chen HS, Chen QY, Chen SM, Chen YX, Chen Y, Cheng J, Cheng ZK, Cherwinka JJ, Chu MC, Chukanov A, Cummings JP, Ding YY, Diwan MV, Dolgareva M, Dove J, Dwyer DA, Edwards WR, Gill R, Gonchar M, Gong GH, Gong H, Grassi M, Gu WQ, Guo L, Guo XH, Guo YH, Guo Z, Hackenburg RW, Hans S, He M, Heeger KM, Heng YK, Higuera A, Hsiung YB, Hu BZ, Hu T, Huang EC, Huang HX, Huang XT, Huang YB, Huber P, Huo W, Hussain G, Jaffe DE, Jen KL, Ji XP, Ji XL, Jiao JB, Johnson RA, Jones D, Kang L, Kettell SH, Khan A, Kohn S, Kramer M, Kwan KK, Kwok MW, Langford TJ, Lau K, Lebanowski L, Lee J, Lee JHC, Lei RT, Leitner R, Leung JKC, Li C, Li DJ, Li F, Li GS, Li QJ, Li S, Li SC, Li WD, Li XN, Li XQ, Li YF, Li ZB, Liang H, Lin CJ, Lin GL, Lin S, Lin SK, Lin YC, Ling JJ, Link JM, Littenberg L, Littlejohn BR, Liu JL, Liu JC, Loh CW, Lu C, Lu HQ, Lu JS, Luk KB, Ma XY, Ma XB, Ma YQ, Malyshkin Y, Martinez Caicedo DA, McDonald KT, McKeown RD, Mitchell I, Nakajima Y, Napolitano J, Naumov D, Naumova E, Ngai HY, Ochoa-Ricoux JP, Olshevskiy A, Pan HR, Park J, Patton S, Pec V, Peng JC, Pinsky L, Pun CSJ, Qi FZ, Qi M, Qian X, Qiu RM, Raper N, Ren J, Rosero R, Roskovec B, Ruan XC, Steiner H, Stoler P, Sun JL, Tang W, Taychenachev D, Treskov K, Tsang KV, Tull CE, Viaux N, Viren B, Vorobel V, Wang CH, Wang M, Wang NY, Wang RG, Wang W, Wang X, Wang YF, Wang Z, Wang Z, Wang ZM, Wei HY, Wen LJ, Whisnant K, White CG, Whitehead L, Wise T, Wong HLH, Wong SCF, Worcester E, Wu CH, Wu Q, Wu WJ, Xia DM, Xia JK, Xing ZZ, Xu JL, Xu Y, Xue T, Yang CG, Yang H, Yang L, Yang MS, Yang MT, Yang YZ, Ye M, Ye Z, Yeh M, Young BL, Yu ZY, Zeng S, Zhan L, Zhang C, Zhang CC, Zhang HH, Zhang JW, Zhang QM, Zhang R, Zhang XT, Zhang YM, Zhang YX, Zhang YM, Zhang ZJ, Zhang ZY, Zhang ZP, Zhao J, Zhou L, Zhuang HL, Zou JH. Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay. PHYSICAL REVIEW LETTERS 2017; 118:251801. [PMID: 28696753 DOI: 10.1103/physrevlett.118.251801] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Indexed: 06/07/2023]
Abstract
The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 GW_{th} reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective ^{239}Pu fission fractions F_{239} from 0.25 to 0.35, Daya Bay measures an average IBD yield σ[over ¯]_{f} of (5.90±0.13)×10^{-43} cm^{2}/fission and a fuel-dependent variation in the IBD yield, dσ_{f}/dF_{239}, of (-1.86±0.18)×10^{-43} cm^{2}/fission. This observation rejects the hypothesis of a constant antineutrino flux as a function of the ^{239}Pu fission fraction at 10 standard deviations. The variation in IBD yield is found to be energy dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1σ. This discrepancy indicates that an overall deficit in the measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes ^{235}U, ^{239}Pu, ^{238}U, and ^{241}Pu. Based on measured IBD yield variations, yields of (6.17±0.17) and (4.27±0.26)×10^{-43} cm^{2}/fission have been determined for the two dominant fission parent isotopes ^{235}U and ^{239}Pu. A 7.8% discrepancy between the observed and predicted ^{235}U yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.
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Liu J. On the Consistency of Q-Matrix Estimation: A Commentary. PSYCHOMETRIKA 2017; 82:523-527. [PMID: 26630990 DOI: 10.1007/s11336-015-9487-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Indexed: 06/05/2023]
Abstract
This commentary concerns the theoretical properties of the estimation procedure in "A General Method of Empirical Q-matrix Validation" by Jimmy de la Torre and Chia-Yi Chiu. It raises the consistency issue of the estimator, proposes some modifications to it, and also makes some conjectures.
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Thanh LHV, Liu JC. Flotation separation of strontium via phosphate precipitation. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 75:2520-2526. [PMID: 28617270 DOI: 10.2166/wst.2017.129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Flotation separation of strontium (Sr) from wastewater via phosphate precipitation was investigated. While 37.33% of Sr precipitated at highly alkaline pH in the absence of PO43-, it completely precipitated as Sr3(PO4)2 at a molar ratio ([PO43-]:[Sr2+]) of 0.62 at a lower pH value. The presence of Ca2+ hindered Sr precipitation, yet it could be overcome by increasing the PO43- dose. Sodium dodecyl sulfate (SDS) was a better collector for dispersed air flotation of Sr3(PO4)2 than cetyl trimethyl ammonium bromide, or mixed collector systems of SDS and saponin. The highest separation efficiency of 97.5% was achieved at an SDS dose of 40 mg/L. The main mechanism in the precipitate flotation is adsorption of anionic SDS on the positively charged surface of colloidal Sr3(PO4)2 via electrostatic interaction. SDS enhanced the aggregation of Sr3(PO4)2 precipitates as the size increased from 1.65 to 28.0 μm, which was beneficial to separation as well.
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Dong L, Shi YK, Xu JP, Zhang EY, Liu JC, Li YX, Ni YM, Yang Q, Han T, Fu B, Chen J, Ren L, Wei SL, Chen H, Liu KX, Yu FX, Liu JS, Xiao MD, Wu SM, Zhang KL, Huang HL, Jiang SL, Qiao CH, Wang CS, Xu ZY, Zhou XM, Wang DJ, Ni LX, Xiao YB, Jiang SL, Zhang GM, Liang GY, Yang SY, Bo P, Zhong QJ, Zhang JB, Zhang X, Zhu YB, Teng X, Zhu P, Huang F, Xiao YM, Cao GQ, Tian H, Xia LM, Lu FL, Liu YQ, Liu DX, Xu H, Yuan Y, Li M, Chang C, Wu XC, Xu Z, Guo P, Bai YJ, Xue WB, Jiang XY, Na ZH, Zeng QY, Cai H, Wang YL, Xiong R, Jin S, Zheng XM, Wu D. [The multicenter study on the registration and follow-up of low anticoagulation therapy for the heart valve operation in China]. ZHONGHUA YI XUE ZA ZHI 2017; 96:1489-94. [PMID: 27266493 DOI: 10.3760/cma.j.issn.0376-2491.2016.19.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To investigate the optimal anticoagulation methods and monitoring strategy for Chinese patients undergoing heart valve replacement, which is potentially quite different from western populations. METHODS In this multicenter prospective cohort study, the anticoagulation and monitoring strategy data was acquired from 25 773 in-hospital patients in 35 medical centers and 20 519 patients in outpatient clinic in 11 medical centers from January 1st, 2011 to December 31th, 2015. RESULTS As for in-hospital patients, mean age of study population was (48.6±11.2) years old; main etiology of valve pathology was rheumatic (87.5%) origin among study cohort; 94.8% of study population received mechanical valve implantation; international normalized ratio (INR) monitoring (in all the study centers) and low-intensity anticoagulation strategy (31 hospitals chose target INR range of 1.5-2.5, and actual values of INR among 89.2% of 100 069 in-hospital monitoring samples were 1.5-2.5), with mean actual INR values of 1.84±0.53, and warfarin dosage of (2.82±0.93) mg/d were widely adopted among the study centers; strategies of in-hospital warfarin administration were similar in all the study centers; complication rates of low-intensity anticoagulation strategy were low in severe hemorrhage (0.02%), thrombosis (0.05%), and thromboembolism (0.05%) events, without anticoagulation-related death.As for 18 974 outpatient clinic patients, the follow-up rate was 92.47%, with a total of 30 012 patient-years (Pty). Anticoagulation-related morbidity and mortality rates were 0.67% and 0.15% Pty; major hemorrhage morbidity and mortality rates were 0.25% and 0.13% Pty; thromboembolism morbidity and mortality rates were 0.45% and 0.03% Pty.The mean dosage of warfarin daily dosage was (2.85±1.23) mg/d and INR value was 1.82±0.57.No significant regional difference in the intensity of anticoagulation therapy was noted during the study. CONCLUSIONS INR can be used as a normalized indicator for intensity of anticoagulation therapy in China.The optimal anticoagulation intensity with INR range from 1.5 to 2.5 is safe and effective for Chinese patients with heart valve replacement, and there is no significant regional difference in the intensity of anticoagulation therapy.
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Chen Y, Li X, Liu J, Xu G, Ying Z. Exploratory Item Classification Via Spectral Graph Clustering. APPLIED PSYCHOLOGICAL MEASUREMENT 2017; 41:579-599. [PMID: 29033476 PMCID: PMC5635860 DOI: 10.1177/0146621617692977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Large-scale assessments are supported by a large item pool. An important task in test development is to assign items into scales that measure different characteristics of individuals, and a popular approach is cluster analysis of items. Classical methods in cluster analysis, such as the hierarchical clustering, K-means method, and latent-class analysis, often induce a high computational overhead and have difficulty handling missing data, especially in the presence of high-dimensional responses. In this article, the authors propose a spectral clustering algorithm for exploratory item cluster analysis. The method is computationally efficient, effective for data with missing or incomplete responses, easy to implement, and often outperforms traditional clustering algorithms in the context of high dimensionality. The spectral clustering algorithm is based on graph theory, a branch of mathematics that studies the properties of graphs. The algorithm first constructs a graph of items, characterizing the similarity structure among items. It then extracts item clusters based on the graphical structure, grouping similar items together. The proposed method is evaluated through simulations and an application to the revised Eysenck Personality Questionnaire.
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Li C, Liu JC, Xiao X, Chen X, Yue S, Yu H, Tian FS, Tang NJ. Psychological distress and type 2 diabetes mellitus: a 4-year policemen cohort study in China. BMJ Open 2017; 7:e014235. [PMID: 28132015 PMCID: PMC5278237 DOI: 10.1136/bmjopen-2016-014235] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVES This study investigated whether psychological distress predicts the development of type 2 diabetes mellitus (T2DM) and if the association differs between populations at a high or low diabetes risk level among Chinese police officers. DESIGN Prospective cohort study. SETTING Single centre. PARTICIPANTS 6559 participants underwent clinical measurements at the hospital in April 2007. 5811 police officers participated in the follow-up consisting of new-onset diabetes (NOD) events occurring annually between 2008 and 2011. PRIMARY OUTCOME MEASURES Baseline data were collected from policemen who completed the Symptom Checklist 90-Revised (SCL-90-R) questionnaire and a self-designed questionnaire. Psychological distress was measured by the SCL-90-R questionnaire. Hong Kong Chinese Diabetes Risk Score (HKCDRS) was used to evaluate the risk of T2DM, and the participants were divided into low-risk group and high-risk group based on the HKCDRS. Cox proportional hazards regression was used to calculate the HRs of the incidence of T2DM related to psychological distress and further stratified the analysis based on HKCDRS. RESULTS Among 5811 participants, 179 subjects developed NOD during the 4-year follow-up. 54 subjects (1.63%) with a HKCDRS 0-7 vs 125 subjects (4.98%) with a HKCDRS>7 developed NOD (p<0.05). There was a significant association between psychological distress and T2DM (HR=1.46; 95% CI 1.05 to 2.02). Among the participants with a high-risk score (HKCDRS>7), 7.07% of those with psychological distress developed T2DM compared with 4.43% of participants without psychological distress (p<0.05). The corresponding adjusted HR for psychological distress was 1.61 (95% CI 1.10 to 2.37). CONCLUSIONS Psychological distress is an independent risk factor for T2DM in this prospective cohort study. Stratification analysis indicated that psychological distress was associated with T2DM in a high-risk level population.
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Sun J, Chen Y, Liu J, Ying Z, Xin T. Latent Variable Selection for Multidimensional Item Response Theory Models via [Formula: see text] Regularization. PSYCHOMETRIKA 2016; 81:921-939. [PMID: 27699561 DOI: 10.1007/s11336-016-9529-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 03/22/2016] [Indexed: 06/06/2023]
Abstract
We develop a latent variable selection method for multidimensional item response theory models. The proposed method identifies latent traits probed by items of a multidimensional test. Its basic strategy is to impose an [Formula: see text] penalty term to the log-likelihood. The computation is carried out by the expectation-maximization algorithm combined with the coordinate descent algorithm. Simulation studies show that the resulting estimator provides an effective way in correctly identifying the latent structures. The method is applied to a real dataset involving the Eysenck Personality Questionnaire.
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Chen Y, Li X, Liu J, Ying Z. Regularized Latent Class Analysis with Application in Cognitive Diagnosis. PSYCHOMETRIKA 2016; 82:10.1007/s11336-016-9545-6. [PMID: 27905058 PMCID: PMC5513805 DOI: 10.1007/s11336-016-9545-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 07/12/2016] [Indexed: 05/28/2023]
Abstract
Diagnostic classification models are confirmatory in the sense that the relationship between the latent attributes and responses to items is specified or parameterized. Such models are readily interpretable with each component of the model usually having a practical meaning. However, parameterized diagnostic classification models are sometimes too simple to capture all the data patterns, resulting in significant model lack of fit. In this paper, we attempt to obtain a compromise between interpretability and goodness of fit by regularizing a latent class model. Our approach starts with minimal assumptions on the data structure, followed by suitable regularization to reduce complexity, so that readily interpretable, yet flexible model is obtained. An expectation-maximization-type algorithm is developed for efficient computation. It is shown that the proposed approach enjoys good theoretical properties. Results from simulation studies and a real application are presented.
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Adamson P, An FP, Anghel I, Aurisano A, Balantekin AB, Band HR, Barr G, Bishai M, Blake A, Blyth S, Bock GJ, Bogert D, Cao D, Cao GF, Cao J, Cao SV, Carroll TJ, Castromonte CM, Cen WR, Chan YL, Chang JF, Chang LC, Chang Y, Chen HS, Chen QY, Chen R, Chen SM, Chen Y, Chen YX, Cheng J, Cheng JH, Cheng YP, Cheng ZK, Cherwinka JJ, Childress S, Chu MC, Chukanov A, Coelho JAB, Corwin L, Cronin-Hennessy D, Cummings JP, de Arcos J, De Rijck S, Deng ZY, Devan AV, Devenish NE, Ding XF, Ding YY, Diwan MV, Dolgareva M, Dove J, Dwyer DA, Edwards WR, Escobar CO, Evans JJ, Falk E, Feldman GJ, Flanagan W, Frohne MV, Gabrielyan M, Gallagher HR, Germani S, Gill R, Gomes RA, Gonchar M, Gong GH, Gong H, Goodman MC, Gouffon P, Graf N, Gran R, Grassi M, Grzelak K, Gu WQ, Guan MY, Guo L, Guo RP, Guo XH, Guo Z, Habig A, Hackenburg RW, Hahn SR, Han R, Hans S, Hartnell J, Hatcher R, He M, Heeger KM, Heng YK, Higuera A, Holin A, Hor YK, Hsiung YB, Hu BZ, Hu T, Hu W, Huang EC, Huang HX, Huang J, Huang XT, Huber P, Huo W, Hussain G, Hylen J, Irwin GM, Isvan Z, Jaffe DE, Jaffke P, James C, Jen KL, Jensen D, Jetter S, Ji XL, Ji XP, Jiao JB, Johnson RA, de Jong JK, Joshi J, Kafka T, Kang L, Kasahara SMS, Kettell SH, Kohn S, Koizumi G, Kordosky M, Kramer M, Kreymer A, Kwan KK, Kwok MW, Kwok T, Lang K, Langford TJ, Lau K, Lebanowski L, Lee J, Lee JHC, Lei RT, Leitner R, Leung JKC, Li C, Li DJ, Li F, Li GS, Li QJ, Li S, Li SC, Li WD, Li XN, Li YF, Li ZB, Liang H, Lin CJ, Lin GL, Lin S, Lin SK, Lin YC, Ling JJ, Link JM, Litchfield PJ, Littenberg L, Littlejohn BR, Liu DW, Liu JC, Liu JL, Loh CW, Lu C, Lu HQ, Lu JS, Lucas P, Luk KB, Lv Z, Ma QM, Ma XB, Ma XY, Ma YQ, Malyshkin Y, Mann WA, Marshak ML, Martinez Caicedo DA, Mayer N, McDonald KT, McGivern C, McKeown RD, Medeiros MM, Mehdiyev R, Meier JR, Messier MD, Miller WH, Mishra SR, Mitchell I, Mooney M, Moore CD, Mualem L, Musser J, Nakajima Y, Naples D, Napolitano J, Naumov D, Naumova E, Nelson JK, Newman HB, Ngai HY, Nichol RJ, Ning Z, Nowak JA, O'Connor J, Ochoa-Ricoux JP, Olshevskiy A, Orchanian M, Pahlka RB, Paley J, Pan HR, Park J, Patterson RB, Patton S, Pawloski G, Pec V, Peng JC, Perch A, Pfützner MM, Phan DD, Phan-Budd S, Pinsky L, Plunkett RK, Poonthottathil N, Pun CSJ, Qi FZ, Qi M, Qian X, Qiu X, Radovic A, Raper N, Rebel B, Ren J, Rosenfeld C, Rosero R, Roskovec B, Ruan XC, Rubin HA, Sail P, Sanchez MC, Schneps J, Schreckenberger A, Schreiner P, Sharma R, Moed Sher S, Sousa A, Steiner H, Sun GX, Sun JL, Tagg N, Talaga RL, Tang W, Taychenachev D, Thomas J, Thomson MA, Tian X, Timmons A, Todd J, Tognini SC, Toner R, Torretta D, Treskov K, Tsang KV, Tull CE, Tzanakos G, Urheim J, Vahle P, Viaux N, Viren B, Vorobel V, Wang CH, Wang M, Wang NY, Wang RG, Wang W, Wang X, Wang YF, Wang Z, Wang ZM, Webb RC, Weber A, Wei HY, Wen LJ, Whisnant K, White C, Whitehead L, Whitehead LH, Wise T, Wojcicki SG, Wong HLH, Wong SCF, Worcester E, Wu CH, Wu Q, Wu WJ, Xia DM, Xia JK, Xing ZZ, Xu JL, Xu JY, Xu Y, Xue T, Yang CG, Yang H, Yang L, Yang MS, Yang MT, Ye M, Ye Z, Yeh M, Young BL, Yu ZY, Zeng S, Zhan L, Zhang C, Zhang HH, Zhang JW, Zhang QM, Zhang XT, Zhang YM, Zhang YX, Zhang ZJ, Zhang ZP, Zhang ZY, Zhao J, Zhao QW, Zhao YB, Zhong WL, Zhou L, Zhou N, Zhuang HL, Zou JH. Limits on Active to Sterile Neutrino Oscillations from Disappearance Searches in the MINOS, Daya Bay, and Bugey-3 Experiments. PHYSICAL REVIEW LETTERS 2016; 117:151801. [PMID: 27768356 DOI: 10.1103/physrevlett.117.151801] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Indexed: 06/06/2023]
Abstract
Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^{2}2θ_{μe} are set over 6 orders of magnitude in the sterile mass-squared splitting Δm_{41}^{2}. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Δm_{41}^{2}<0.8 eV^{2} at 95% CL_{s}.
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An FP, Balantekin AB, Band HR, Bishai M, Blyth S, Cao D, Cao GF, Cao J, Cen WR, Chan YL, Chang JF, Chang LC, Chang Y, Chen HS, Chen QY, Chen SM, Chen YX, Chen Y, Cheng JH, Cheng J, Cheng YP, Cheng ZK, Cherwinka JJ, Chu MC, Chukanov A, Cummings JP, de Arcos J, Deng ZY, Ding XF, Ding YY, Diwan MV, Dolgareva M, Dove J, Dwyer DA, Edwards WR, Gill R, Gonchar M, Gong GH, Gong H, Grassi M, Gu WQ, Guan MY, Guo L, Guo RP, Guo XH, Guo Z, Hackenburg RW, Han R, Hans S, He M, Heeger KM, Heng YK, Higuera A, Hor YK, Hsiung YB, Hu BZ, Hu T, Hu W, Huang EC, Huang HX, Huang XT, Huber P, Huo W, Hussain G, Jaffe DE, Jaffke P, Jen KL, Jetter S, Ji XP, Ji XL, Jiao JB, Johnson RA, Joshi J, Kang L, Kettell SH, Kohn S, Kramer M, Kwan KK, Kwok MW, Kwok T, Langford TJ, Lau K, Lebanowski L, Lee J, Lee JHC, Lei RT, Leitner R, Leung JKC, Li C, Li DJ, Li F, Li GS, Li QJ, Li S, Li SC, Li WD, Li XN, Li YF, Li ZB, Liang H, Lin CJ, Lin GL, Lin S, Lin SK, Lin YC, Ling JJ, Link JM, Littenberg L, Littlejohn BR, Liu DW, Liu JL, Liu JC, Loh CW, Lu C, Lu HQ, Lu JS, Luk KB, Lv Z, Ma QM, Ma XY, Ma XB, Ma YQ, Malyshkin Y, Martinez Caicedo DA, McDonald KT, McKeown RD, Mitchell I, Mooney M, Nakajima Y, Napolitano J, Naumov D, Naumova E, Ngai HY, Ning Z, Ochoa-Ricoux JP, Olshevskiy A, Pan HR, Park J, Patton S, Pec V, Peng JC, Pinsky L, Pun CSJ, Qi FZ, Qi M, Qian X, Raper N, Ren J, Rosero R, Roskovec B, Ruan XC, Steiner H, Sun GX, Sun JL, Tang W, Taychenachev D, Treskov K, Tsang KV, Tull CE, Viaux N, Viren B, Vorobel V, Wang CH, Wang M, Wang NY, Wang RG, Wang W, Wang X, Wang YF, Wang Z, Wang Z, Wang ZM, Wei HY, Wen LJ, Whisnant K, White CG, Whitehead L, Wise T, Wong HLH, Wong SCF, Worcester E, Wu CH, Wu Q, Wu WJ, Xia DM, Xia JK, Xing ZZ, Xu JY, Xu JL, Xu Y, Xue T, Yang CG, Yang H, Yang L, Yang MS, Yang MT, Ye M, Ye Z, Yeh M, Young BL, Yu ZY, Zeng S, Zhan L, Zhang C, Zhang HH, Zhang JW, Zhang QM, Zhang XT, Zhang YM, Zhang YX, Zhang YM, Zhang ZJ, Zhang ZY, Zhang ZP, Zhao J, Zhao QW, Zhao YB, Zhong WL, Zhou L, Zhou N, Zhuang HL, Zou JH. Improved Search for a Light Sterile Neutrino with the Full Configuration of the Daya Bay Experiment. PHYSICAL REVIEW LETTERS 2016; 117:151802. [PMID: 27768341 DOI: 10.1103/physrevlett.117.151802] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Indexed: 06/06/2023]
Abstract
This Letter reports an improved search for light sterile neutrino mixing in the electron antineutrino disappearance channel with the full configuration of the Daya Bay Reactor Neutrino Experiment. With an additional 404 days of data collected in eight antineutrino detectors, this search benefits from 3.6 times the statistics available to the previous publication, as well as from improvements in energy calibration and background reduction. A relative comparison of the rate and energy spectrum of reactor antineutrinos in the three experimental halls yields no evidence of sterile neutrino mixing in the 2×10^{-4}≲|Δm_{41}^{2}|≲0.3 eV^{2} mass range. The resulting limits on sin^{2}2θ_{14} are improved by approx imately a factor of 2 over previous results and constitute the most stringent constraints to date in the |Δm_{41}^{2}|≲0.2 eV^{2} region.
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Wan L, Dai SH, Lai SQ, Liu LQ, Wang Q, Xu H, Wang WJ, Liu JC. Apoptosis, proliferation, and morphology during vein graft remodeling in rabbits. GENETICS AND MOLECULAR RESEARCH 2016; 15:gmr8701. [PMID: 27808365 DOI: 10.4238/gmr.15048701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Neo-intima development and atherosclerosis limit the long-term use of vein grafts for revascularization of ischemic tissues. Recently, studies have confirmed that proliferating cell nuclear antigen (PCNA) plays an important role in cell proliferation. Our research confirmed that 28 days after vein transplantation, PCNA expression increases significantly. Using rabbits, rather than rodents, for a more representative model of human vein grafts, we aimed to establish a time course of changes in cell proliferation and apoptosis using morphometric and immunohistochemical analyses, western blot, terminal deoxynucleotidyl transferase dUTP nick end labeling, and transmission electron microscopy (TEM). The external jugular veins of 42 healthy purebred male New Zealand white rabbits were grafted onto their common carotid arteries. The rabbits were divided into seven groups, with vein grafts being harvested before surgery, and at 1, 3, 7, 14, 28, and 90 days afterwards. The extent of stenosis and apoptosis, PCNA protein levels, and TEM morphology were subsequently examined. Intimal thickness was slightly decreased 1 day following surgery, but then increased continuously until the 90th day. Western blot and immunohistochemistry both indicated lowered PCNA expression on day 1, although levels subsequently increased, peaking at 7 days post-surgery. After surgery, apoptosis was lowest on day 7, and remained low thereafter. TEM revealed signs of apoptosis as vein graft restenosis progressed. Proliferation and apoptosis co-occurred following grafting, indicating that both processes were involved in vein graft remodeling. Apoptosis levels were highest between days 1 and 3 after surgery, whereas proliferation culminated on the 7th day.
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