334 research outputs found

    Patient-Specific Method of Generating Parametric Maps of Patlak K(i) without Blood Sampling or Metabolite Correction: A Feasibility Study.

    Get PDF
    Currently, kinetic analyses using dynamic positron emission tomography (PET) experience very limited use despite their potential for improving quantitative accuracy in several clinical and research applications. For targeted volume applications, such as radiation treatment planning, treatment monitoring, and cerebral metabolic studies, the key to implementation of these methods is the determination of an arterial input function, which can include time-consuming analysis of blood samples for metabolite correction. Targeted kinetic applications would become practical for the clinic if blood sampling and metabolite correction could be avoided. To this end, we developed a novel method (Patlak-P) of generating parametric maps that is identical to Patlak K(i) (within a global scalar multiple) but does not require the determination of the arterial input function or metabolite correction. In this initial study, we show that Patlak-P (a) mimics Patlak K(i) images in terms of visual assessment and target-to-background (TB) ratios of regions of elevated uptake, (b) has higher visual contrast and (generally) better image quality than SUV, and (c) may have an important role in improving radiotherapy planning, therapy monitoring, and neurometabolism studies

    Comparable, but distinct: Perceptions of primary care provided by physicians and nurse practitioners in full and restricted practice authority states

    Full text link
    AimsTo understand patients- and providers- perceptions of primary care delivered by nurse practitioners (NPs) in the Veterans Affairs Healthcare System.DesignQualitative exploratory study (in convergent mixed- methods design).MethodsSemi- structured interviews in 2016 with primary care providers and patients from facilities in states with full and restricted practice authority for NPs. Patient sample based on reassignment to: (a) a NP; or (b) a different physician following an established physician relationship. Data were analysed using content analysis.ResultsWe interviewed 28 patients, 17 physicians and 14 NPs. We found: (a) NPs provided more holistic care than physicians; (b) patients were satisfied with NPs; and (c) providers- professional experience outweighed provider type.ConclusionsPatients- preferences for NPs (compared with prior physicians) contributed to perceptions of patient centredness. Similarities in providers- perceptions suggest NPs and physicians are both viable providers for primary care.ImpactNurse Practitioners (NPs): practice authorityVeterans Affairs Health care: nurse practitioners will continue to be a viable resource for primary care deliveryUnited States Health care: challenges notions patients may not be satisfied with care provided by NPs and supports expanding their use to provide much- needed access to primary care services; expanding Full Practice Authority would allow states to provide acceptable primary care without diminishing patient or provider experiencesæ è¦ ç ®æ  äº è§£æ £è å å »ç æ ºæ 对é ä¼ å äººå »ç ä¿ å ¥ç³»ç» ä¸­æ ¤ç å¸ æ ä¾ å çº§æ ¤ç ç ç æ³ ã è®¾è®¡æ ¢ç´¢æ §ç å® æ §ç  ç©¶(æ ¶æ æ··å æ ¹æ³ è®¾è®¡)ã æ ¹æ³ 2016å¹´è¿ è¡ ç å ç» æ å è®¿è° ,é è®¿äº å· å æ ¥æ æ ¤ç å¸ ç å ¨ç§ å é å ¨ç§ æ §ä¸ æ ºæ ç å çº§æ ¤ç æ ä¾ è å æ £è ã é æ °å é æ £è æ ·æ ¬:(a) ä¸ å æ ¤ç å¸ ;æ (b)ç¡®ç« å »ç å ³ç³»ç å ¦ä¸ å å »ç ã é ç ¨å 容å æ æ³ å¯¹æ °æ ®è¿ è¡ å æ ã ç» æ æ 们é è®¿äº 28å æ £è ,17å å »ç å 14å æ ¤ç å¸ ã æ 们å ç °:(a)æ ¤ç å¸ æ¯ å »ç æ ä¾ ç æ ¤ç æ ´å ¨é ¢;(b)æ £è å¯¹æ ¤ç å¸ æ å °æ»¡æ ;(c)å »ç æ ºæ ç ä¸ ä¸ ç» éª ç æ é æ¯ å »ç æ ºæ ç±»å ç æ é æ ´å¤§ã ç» è®ºæ £è å¯¹æ ¤ç å¸ ç å 好(ä¸ ä»¥å ç å »ç ç ¸æ¯ )æ å ©äº å»ºç« ä»¥æ £è ä¸ºä¸­å¿ ç è®¤ç ¥ã æ ä¾ è ç è§ å¿µç±»ä¼¼,表æ æ ¤ç å¸ å å »ç é ½æ ¯å ¯è¡ ç å çº§æ ¤ç æ ä¾ è ã å½±å - ¢æ ¤ç å¸ :æ §ä¸ æ ºæ - ¢é ä¼ å äººå »ç ä¿ å ¥ç³»ç» :æ ¤ç å¸ å° ç»§ç»­ä½ ä¸ºæ ä¾ å çº§æ ¤ç æ å ¡ç å ¯ç ¨èµ æº ã - ¢ç¾ å ½å «ç ä¿ å ¥:æ æ è§ å¿µ æ £è å ¯è ½ä¸ æ»¡æ ç ±æ ¤ç å¸ æ ä¾ ç æ ¤ç ,å ¶ä¼ æ ¯æ æ ©å¤§ä½¿ç ¨è å ´,以æ ä¾ æ ¥é ç å çº§ä¿ å ¥æ å ¡;æ ©å¤§å ¨ç§ æ §ä¸ æ ºæ å° ä½¿å å· è ½å¤ æ ä¾ å ¯æ ¥å ç å çº§ä¿ å ¥æ å ¡,è ä¸ ä¼ å å¼±æ £è æ æ ä¾ è ç ä½ éª ãPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163369/2/jan14501.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163369/1/jan14501_am.pd

    Biomarkers of severity and threshold of allergic reactions during oral peanut challenges

    Get PDF
    Background: oral food challenge (OFC) is the criterion standard to assess peanut allergy (PA), but it involves a risk of allergic reactions of unpredictable severity.Objective: our aim was to identify biomarkers for risk of severe reactions or low dose threshold during OFC to peanut.Methods: we assessed Learning Early about Peanut Allergy study, Persistance of Oral Tolerance to Peanut study, and Peanut Allergy Sensitization study participants by administering the basophil activation test (BAT) and the skin prick test (SPT) and measuring the levels of peanut-specific IgE, Arachis hypogaea 2–specific IgE, and peanut-specific IgG4, and we analyzed the utility of the different biomarkers in relation to PA status, severity, and threshold dose of allergic reactions to peanut during OFC.Results: when a previously defined optimal cutoff was used, the BAT diagnosed PA with 98% specificity and 75% sensitivity. The BAT identified severe reactions with 97% specificity and 100% sensitivity. The SPT, level of Arachis hypogaea 2–specific IgE, level of peanut-specific IgE, and IgG4/IgE ratio also had 100% sensitivity but slightly lower specificity (92%, 93%, 90%, and 88%, respectively) to predict severity. Participants with lower thresholds of reactivity had higher basophil activation to peanut in vitro. The SPT and the BAT were the best individual predictors of threshold. Multivariate models were superior to individual biomarkers and were used to generate nomograms to calculate the probability of serious adverse events during OFC for individual patients.Conclusions: the BAT diagnosed PA with high specificity and identified severe reactors and low threshold with high specificity and high sensitivity. The BAT was the best biomarker for severity, surpassed only by the SPT in predicting threshold. Nomograms can help estimate the likelihood of severe reactions and reactions to a low dose of allergen in individual patients with PA

    Reduction of N=1, E_8 SYM over SU(3)/U(1) x U(1) x Z_3 and its four-dimensional effective action

    Full text link
    We propose an extension of the Standard Model inspired by the E_8 x E_8 Heterotic String. In order that a reasonable effective Lagrangian is presented we neglect everything else other than the ten-dimensional N=1 supersymmetric Yang-Mills sector associated with one of the gauge factors and certain couplings necessary for anomaly cancellation. We consider a compactified space-time M_4 x B_0/Z_3, where B_0 is the nearly Kaehler manifold SU(3)/U(1) x U(1) and Z_3 is a freely acting discrete group on B_0. Then we reduce dimensionally the E_8 on this manifold and we employ the Wilson flux mechanism leading in four dimensions to an SU(3)^3 gauge theory with the spectrum of a N=1 supersymmetric theory. We compute the effective four-dimensional Lagrangian and demonstrate that an extension of the Standard Model is obtained with interesting features including a conserved baryon number and fixed tree level Yukawa couplings and scalar potential. The spectrum contains new states such as right handed neutrinos and heavy vector-like quarks.Comment: 15 page
    corecore