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Single-center study comparing computed tomography colonography with conventional colonoscopy

World journal of Gastroenterology 2008年第3期14卷 469-473页

作者： Ian C Roberts-Thomson Graeme R Tucker peter j hewett peter Cheung Ruben A Sebben EE Win Khoo julie D Marker Wayne K Clapton Department of Gastroenterology The Queen Elizabeth Hospital South Australia Australia Department of Health South Australia Australia Department of Colorectal Surgery The Queen Elizabeth Hospital South Australia Australia Department of Radiology The Queen Elizabeth Hospital South Australia Australia

AIM:To compare the results from computed tomography (CT) colonography with conventional colonoscopy in symptomatic patients referred for colonoscopy. METHODS: The study included 227 adult outpatients, mean age 60 years, with appropriate indications for colonoscopy. CT colonography and colonoscopy were performed on the same day in a metropolitan teaching hospital. Colonoscopists were initially blinded to the results of CT colonography but there was segmental unblinding during the procedure. The primary outcome measures were the sensitivity and specificity of CT colonography for the identification of polyps seen at colonoscopy (i.e. analysis by polyp). Secondary outcome measures included an analysis by patient, extracolonic findings at CT colonography, adverse events with both procedures and patient acceptance and preference. RESULTS: Twenty-five patients (11%) were excluded from the analysis because of incomplete colonoscopy or poor bowel preparation that affected either CT colonography, colonoscopy or both procedures. Polyps and masses (usually cancers) were detected at colonoscopy and CT colonography in 35% and 42% of patients, respectively. Of nine patients with a finaldiagnosis of cancer, eight (89%) were identified by CT colonography as masses (5) or polyps (3). For polyps analyzed according to polyp, the overall sensitivity of CT colonography was 50% (95% CI, 39%-61%) but this increased to 71% (95% CI, 52%-85%) for polyps ≥ 6 mm in size. Similarly, specificity for all polyps was 48% (95% CI, 39%-58%) increasing to 67% (95% CI, 56%-76%) for polyps ≥ 6 mm. Adverse events were uncommon but included one colonic perforation at colonoscopy. Patient acceptance was high for both procedures but preference favoured CT colonography. CONCLUSION: Although CT colonography was more sensitive in this study than in some previous studies, the procedure is not yet sensitive enough for widespread application in symptomatic patients.

关键词： Colorectal polyps Colorectal cancer Computed tomography colonography Colonoscopy

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From first fibers to mode-division multiplexing(Invited Paper)

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Chinese Optics Letters 2016年第12期14卷 2-6页

作者： peter j.Winzer Nokia Bell Labs Holmdel NJ 07733 USA

This Review focuses on optical transmission fibers and the high-capacity systems operating thereon. It attempts to combine key lessons learned from the 50-year history of low-loss optical fibers with views on future fiber and systems requirements, discussing likely evolution paths and potential pitfalls in resolving the optical network capacity crunch.

关键词： multiplexing crosstalk likely resolving combine installed learned today coherent deployment

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Mass Transport in Nanowire Synthesis:An Overview of Scalable Nanomanufacturing

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journal of Materials Science & Technology 2015年第6期31卷 523-532页

作者： Matthew j.Crane peter j.Pauzauskie Department of Chemical Engineering University of WashingtonSeattleWA 98195-1750.USA Department of Materials Science & Engineering Seattle.WA 98195-2120USA Fundamental Computational Science Directorate Pacific Northwest National LaboratoryRichland.WAUSA

The ability to rationally engineer the growth and nanomanufacturing of one-dimensional nanowires in high volumes has the potential to enable applications of nanoscale materials in a diverse range of fields including energy conversion and storage,catalysis,sensing,medicine,and information *** review provides a roadmap for the development of large-scale nanowire *** myriad techniques exist for bench-scale nanowire synthesis,these growth strategies typically fall within two major categories:1) anisotropically-catalyzed growth and 2) confined,template-based ***,comparisons between growth methods with different mass transport pathways have led to confusion in interpreting observations,in particular Gibbs-Thomson *** review mass transport in nanowire synthesis techniques to unify growth models and to allow for direct comparison of observations across different *** addition,we discuss the applicability of nanoscale,Gibbs-Thomson effects on mass transport and provide guidelines for the development of new growth *** explore the scalability of these complex processes with dimensionless numbers and consider the effects of pressure,temperature,and precursor material on nanowire growth.

关键词： Nanowire Mass transport Modeling Scalable growth

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Duality for cochain DG algebras

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Science China Mathematics 2013年第1期56卷 79-89页

作者： jφRGENSEN peter School of Mathematics and Statistics Newcastle University

This paper develops a duality theory for connected cochain DG algebras,with particular emphasis on the non-commutative *** of the main items is a dualizing DG module which induces a duality between the derived categories of DG left-modules and DG right-modules with finitely generated *** an application,it is proved that if the canonical module k=A/A≥1 has a semi-free resolution where the cohomological degree of the generators is bounded above,then the same is true for each DG module with finitely generated cohomology.

关键词： balanced dualizing complex Castelnuovo-Mumford regularity Cech DG module derived comple-tion derived torsion DG left-module DG right-module dualizing DG module endomorphism DG algebra Extregularity non-commutative DG algebra

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Simulation and calibration of granules using the discrete element method

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Particuology 2014年第1期12卷 40-43页

作者： peter Müller jürgen Tomas Institute of Process Engineering Mechanical Process EngineeringOtto-von-Guericke University MagdeburgUniversitätsplatz 239106 MagdeburgGermany

The discrete element method （DEM）, developed by Cundall and 5track to solve geomecnamcai problems, is used to simulate the mechanical behavior of granules. According to the DEM, an individ ual granule can be modeled as a realistic mechanical system consisting of primary particles bonded by interaction forces. Cranulometric properties of the model material, zeolite 4A, have been measured to determine their macro properties. To investigate the compression behavior, a compression test was performed using a strength tester on single granules between two pistons. A modeled granule consisting of more than 22,000 primary particles was generated. The micro properties of the modeled granule have been precisely set to allow its macro properties to be equivalent to the macro properties of zeolite 4A granules. To calibrate the mechanical properties, diametrical compression was simulated using two rigid walls stressed at a constant stressing velocity, The force-displacement curve of the modeled granule at compression has been calibrated by the experimental curve of zeolite 4A.

关键词： Discrete element method Material behavior Granulation

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Medical therapy for spermatogenic failure

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Asian journal of Andrology 2012年第1期14卷 57-60,176页

作者： Ranjith Ramasamy peter j Stahl peter N Schlegel Department of Urology Weill Cornell Medical College New York NY 10065 USA

Medical treatment of men with primary spermatogenic failure remains largely ineffective in contrast to those with secondary testicular failure. Treatment has been attempted with a multitude of agents ranging from hormones to nutritional supplements （antioxidants）. While some studies have demonstrated benefit to some treatments, no treatments have consistently demonstrated efficacy nor has it been possible to reliably identify patients likely to benefit. Idiopathic spermatogenic failure likely results from multiple discrete defects in sperm production that are as yet unidentified. A better understanding of these defects will yield more effective treatment options and appropriate triage of patients to specific therapeutic regimens. This review focuses on the rationale and current evidence for hormonal and antioxidant therapy in medical treatment of male infertility, spermatogenic failure in particular. Although empiric medical therapy for spermatogenic failure has been largely replaced by assisted reproductive techniques, both treatment modalities could play a role, oerhaos as combination therapy.

关键词： antioxidant hormones male infertility sperm spermatogenesis spermatogenic failure testicular failure

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Making the link between ADF and 4D STEM:Resolution,transfer and coherence

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Chinese Physics B 2024年第11期33卷 26-33页

作者： peter D.Nellist Timothy j.Pennycook Department of Materials University of OxfordOxfordUK EMAT University of AntwerpGroenenborgerlaan 1712020 AntwerpBelgium

Steve Pennycook is a pioneer in the application of high-resolution scanning transmission electron microscopy(STEM)and in particular the use of annular dark-field(ADF)*** we show how a general framework for 4D STEM allows clear links to be made between ADF imaging and the emerging methods for reconstructing images from 4D STEM data *** show that both ADF imaging and ptychographical reconstruction can be thought of in terms of integrating over the overlap regions of diffracted discs in the detector *** approach allows the similarities in parts of their transfer functions to be understood,though we note that the transfer functions for ptychographic imaging cannot be used as a measure of information *** also show that conditions of partial spatial and temporal coherence affect ADF imaging and ptychography similarly,showing that achromatic interference can always contribute to the image in both cases,leading to a robustness to partial temporal coherence that has enabled high-resolution imaging.

关键词： image forming and processing phase retrieval electron microscopy scanning transmission electron microscope(STEM)

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Those amazing dinoflagellate chromosomes

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Cell Research 2003年第4期13卷 215-217页

作者： peter j RIZZO Department of Biology Texas A & M University College Station TX 77843 USA

Dinoflagellates are a very large and diverse group of eukaryotic algae that play a major role in aquatic food webs of both fresh water and marine habitats. Moreover, the toxic members of this group pose a health threat in the form of red tides. Finally, dinoflagellates are of great evolutionary importance, because of their taxonomic position, and their unusual chromosome structure and composition. While the cytoplasm of dinoflagellates is typically eukaryotic, the nucleus is unique when compared to the nucleus of other eukaryotes. More specifically, while the chromosomes of all other eukaryotes contain histones, dinoflagellate chromosomes lack histones completely. There are no known exceptions to this observation: all dinoflagellates lack histones, and all other eukaryotes contain histones. Nevertheless, dinoflagellates remain a relatively unstudied group of eukaryotes.

关键词： dinofiagellates chromosomes histones histone-like proteins.

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Phase Transitions for Products of Characteristic Polynomials under Dyson Brownian Motion

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Acta Mathematica Sinica,English Series 2021年第3期37卷 509-524页

作者： peter j.FORRESTER Dang-Zheng LIU ARC Centre of Excellence for Mathematical and Statistical Frontiers School of Mathematics and StatisticsThe University of MelbourneVictoria 3010Australia CAS Key Laboratory of Wu Wen-Tsun Mathematics School of Mathematical SciencesUniversity of Science and Technology of ChinaHefei 230026P.R.China

We study the averaged products of characteristic polynomials for the Gaussian and Laguerre β-ensembles with external source, and prove Pearcey-type phase transitions for particular full rank perturbations of source. The phases are characterised by determining the explicit functional forms of the scaled limits of the averaged products of characteristic polynomials, which are given as certain multidimensional integrals, with dimension equal to the number of products.

关键词： Random matrices Dyson Brownian motion β-ensembles phase transitions

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The effects of gonadal hormones on learning and memory in male mammals： A review

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Current Zoology 2011年第4期57卷 543-558页

作者： Stuart T. LEONARD peter j. WINSAUER Department of Pharmacology and Experimental Therapeutics Louisiana State University Health Sciences Center 1901 Perdido Street New Orleans LA 70112-1393

The primary role of the gonadal steroid hormones in mammals is to regulate reproduction and related behaviors; however, both androgens and estrogens are also integrally involved in mediating higher brain function and processes including cognition, neural development, and neural plasticity. In particular, a number of studies show that estradiol modulates dendritic spine growth and synapse density （synaptic plasticity） in the hippocampus of females, and that increased estradiol levels are generally associated with improvements on a variety of learning and memory tasks. While the majority of research has focused on the beneficial effects of estradiol in females, much less attention has been given to testosterone and its effects on learning and memory in males. Similar to estradiol titers in females, testosterone titers in males decline with age, albeit more gradually, and this decline has been correlated with impairment of certain cognitive tasks. Moreover, studies involving both humans and animals indicate that testosterone and its metabolites can augment responding on certain behavioral tasks, depending on the subject＇s current hormonal state, the response required, and the stimuli involved （e.g., those involving spatial or nonspatial stimuli）. While the exact mechanisms by which testosterone exerts its effects on learning and memory are not fully understood, recent findings suggest that testosterone modulates learning and memory in males through an interaction with the cholinergic system. The overall objective of this review is to discuss studies investigating the role of the gonadal hormones in mediating learning and memory processes in male mammals [Current Zoology 57 （4）： 543-558, 2011].

关键词： Testosterone Learning and memory Cholinergic system Mammals Cognition Androgens

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