31 research outputs found

    Quadratic inference functions in marginal models for longitudinal data

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    The quadratic inference function (QIF) is a new statistical methodology developed for the estimation and inference in longitudinal data analysis using marginal models. This method is an alternative to the popular generalized estimating equations approach, and it has several useful properties such as robustness, a goodness-of-fit test and model selection. This paper presents an introductory review of the QIF, with a strong emphasis on its applications. In particular, a recently developed SAS MACRO QIF is illustrated in this paper to obtain numerical results. Copyright © 2009 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64550/1/3719_ftp.pd

    In situ growth of (NH4)(2)V10O25 center dot 8H(2)O urchin-like hierarchical arrays as superior electrodes for all-solid-state supercapacitors

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    Hierarchical nanostructures with highly exposed active surfaces for use in high-performance pseudocapacitors have attracted considerable attention. Herein, we developed a one-step method for the in situ growth of (NH4)(2)V10O25<bold></bold>8H(2)O urchin-like hierarchical structures on highly conductive nickel foam substrates for use as advanced electrodes for all-solid-state asymmetric supercapacitors. The in situ growth of (NH4)(2)V10O25<bold></bold>8H(2)O urchin-like hierarchical structures delivers a specific capacitance of 1530 F g(-1) at a current density of 1.5 A g(-1), and retains 95.1% of the initial capacitance after 10000 cycles, owing to the advantages of the urchin-like hierarchical structure such as more active sites for electrochemical reactions, as well as a shortened diffusion length for the charge carriers due to a binder-free effect, which exceeds that of most recently reported vanadates and polyvanadates. The as-assembled all-solid-state (NH4)(2)V10O25<bold></bold>8H(2)O@Ni//PVA/KOH//RGO@Ni device exhibits a comparable capacity of 92.2 F g(-1) at a current density of 0.4 A g(-1) and excellent cycling performance through 5000 cycles. Our study provides rational guidance toward the design of novel hierarchical nanostructures of polyvanadate for solid-state supercapacitors with superior electrochemical performances in long-term cycling stability and high energy density

    Integrated Cancer Screening Performance Indicators: A Systematic Review.

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    Cancer screening guidelines recommend that women over 50 years regularly be screened for breast, cervical and colorectal cancers. Population-based screening programs use performance indicators to monitor uptake for each type of cancer screening, but integrated measures of adherence across multiple screenings are rarely reported. Integrated measures of adherence that combine the three cancers cannot be inferred from measures of screening uptake of each cancer alone; nevertheless, they can help discern the proportion of women who, having received one or two types of screening, may be more amenable to receiving one additional screen, compared to those who haven't had any screening and may experience barriers to access screening such as distance, language, and so on. The focus of our search was to identify indicators of participation in the three cancers, therefore our search strategy included synonyms of integrated screening, cervical, breast and colorectal cancer screening. Additionally, we limited our search to studies published between 2000 and 2015, written in English, and pertaining to females over 50 years of age. The following databases were searched: MEDLINE, EMBASE, EBM Reviews, PubMed, PubMed Central, CINAHL, and Nursing Reference Center, as well as grey literature resources. Of the 78 initially retrieved articles, only 7 reported summary measures of screening across the three cancers. Overall, adherence to cervical, breast and colorectal cancer screening ranged from around 8% to 43%. Our review confirms that reports of screening adherence across breast, cervical and colorectal cancers are rare. This is surprising, as integrated cancer screening measures can provide additional insight into the needs of the target population that can help craft strategies to improve adherence to all three screenings

    Improved hybrid reactive power compensation system based on FC and STATCOM and its control method

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    The purpose of this study is to solve the main problems in distribution networks, including increased line loss and reduced power supply quality caused by insufficient capacitive reactive power. To reduce the capacity, voltage, and current stress of an active module of a compensation device and improve the cost performance of the device, an improved hybrid reactive power compensation system based on a fixed capacitor (FC) and a static synchronous compensator (STATCOM) is proposed. The topological structure and basic operating principle of the proposed reactive power compensation system are introduced. In addition, from the perspectives of output voltage, current, power, loss of the active part, and system compensation cost, the performances of the proposed reactive compensator and the inductively coupled STATCOM (L-STATCOM) are compared and analyzed. Furthermore, the key parameters of the proposed system are designed, and the joint optimization control strategy of the FC and STATCOM is studied. The correctness and effectiveness of the proposed topology structure and control method are verified by simulations.Supported by the General Project of Hunan Natural Science Foundation (2021JJ30715), the Scientific Research Fund of Hunan Provincial Education Department (20B029) and the Graduate Research Innovation Project of Changsha University of Science & Technology (CX2021SS52)

    Visualizing the Spatial Distribution of Arctium lappa L. Root Components by MALDI-TOF Mass Spectrometry Imaging

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    This study is aimed at developing novel analytical methods to accurately visualize the spatial distribution of various endogenous components in Arctium lappa L. (A. lappa) roots, and to precisely guide the setting of pre-treatment operations during processing technologies and understand plant metabolism process. The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) imaging technology was used for visual demonstration of the in situ spatial distribution in A. lappa roots. This work consisted of four steps: matrix selection, section preparation, matrix coating, and MALDI-TOF MS imaging analysis. Consequently, eight saccharides, four caffeoylquinic acids, four flavonoids, six amino acids, one choline, and one phospholipid were imaged and four unidentified components were found. Saccharides were distributed in the center, whereas caffeoylquinic acids and flavonoids were mainly present in the epidermis and cortex. Furthermore, amino acids were mainly detected in the phloem, and choline in the cambium, while phosphatidylserine was found in the secondary phloem and cambium. This study demonstrated that MALDI-TOF MS imaging technology could provide a technical support to understand the spatial distribution of components in A. lappa roots, which would promote the processing technologies for A. lappa roots and help us to understand the plant metabolism process

    IDH Mutations Are Potentially the Intrinsic Genetic Link among the Multiple Neoplastic Lesions in Ollier Disease and Maffucci Syndrome: A Clinicopathologic Analysis from a Single Institute in Shanghai, China

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    Background: This study aims to investigate isocitrate dehydrogenase gene mutations in patients with the non-hereditary skeletal disorders of Ollier disease and Maffucci syndrome, particularly in the extraosseous tumours. Methods: A total of 16 tumours from three patients with Ollier disease and three patients with Maffucci syndrome were collected. Sanger sequencing was applied to determine the hotspot mutations of IDH1 and IDH2 genes in multiple neoplastic tissues. Results: A majority of the tumours displayed an IDH1 mutation (p.R132C in 11 tumours including the paediatric ovarian tumour from one patient with Ollier disease, 4 cutaneous haemangiomas from three patients with Maffucci syndrome, 5 enchondromas and 1 chondrosarcoma; p.R132H in 2 cartilaginous tumours from one patient). Conclusions: IDH1 mutations were demonstrated in multiple cartilaginous tumours and extraskeletal neoplasms in this case series. Specifically, identical IDH1 mutations were confirmed in the separate lesions of each patient. These results are in concordance with findings that have been reported. However, here, we additionally reported the first case of Ollier disease with an ovarian tumour, which harboured the identical IDH1 mutation with the corresponding cartilaginous tumour. We further provided evidence that IDH mutations are the potential genetic links among the multiple neoplastic lesions of Ollier disease and Maffucci syndrome
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