Hybrid structures synthesized from different materials have attracted considerable attention because they may allow not only combination of the functionalities of the individual constituents but also ...mutual control of their properties. To obtain such a control an interaction between the components needs to be established. For coupling the magnetic properties, an exchange interaction has to be implemented which typically depends on wavefunction overlap and is therefore short-ranged, so that it may be compromised across the hybrid interface. Here we study a hybrid structure consisting of a ferromagnetic Co layer and a semiconducting CdTe quantum well, separated by a thin (Cd, Mg)Te barrier. In contrast to the expected p-d exchange that decreases exponentially with the wavefunction overlap of quantum well holes and magnetic atoms, we find a long-ranged, robust coupling that does not vary with barrier width up to more than 30 nm. We suggest that the resulting spin polarization of acceptor-bound holes is induced by an effective p-d exchange that is mediated by elliptically polarized phonons.
Research has documented cognitive deficits both before and after high-dose treatment followed by allogeneic hematopoietic cell transplantation (HCT), with partial recovery by 1 year. This study ...prospectively examined the trajectory and extent of long-term cognitive dysfunction, with a focus on 1 to 5 years after treatment.
Allogeneic HCT recipients completed standardized neuropsychological tests including information processing speed (Trail Making A and Digit Symbol Substitution Test), verbal memory (Hopkins Verbal Learning Test-Revised), executive function (Controlled Oral Word Association Test and Trail Making B), and motor dexterity and speed (Grooved Pegboard). Survivors (n = 92) were retested after 80 days and 1 and 5 years after transplantation. Case-matched controls (n = 66) received testing at the 5-year time point. A Global Deficit Score (GDS) summarized overall impairment. Response profiles were analyzed using linear mixed effects models.
Survivors recovered significant cognitive function from post-transplantation (80 days) to 5 years in all tests (P < .0001) except verbal recall (P > .06). Between 1 and 5 years, verbal fluency improved (P = .0002), as did executive function (P < .01), but motor dexterity did not (P > .15), remaining below controls (P < .0001) and more than 0.5 standard deviation below population norms. In GDS, 41.5% of survivors and 19.7% of controls had mild or greater deficits (NcNemar test = 7.04, P = .007).
Although neurocognitive function improved from 1 to 5 years after HCT, deficits remained for more than 40% of survivors. Risk factors, mechanisms and rehabilitation strategies need to be identified for these residual deficits.
To investigate differences in apparent diffusion coefficient (ADC) and T2 values between dense and sparse regions in prostate cancer.
Eighteen patients (median age, 61 years; range, 44-72 years) gave ...informed consent for this retrospective Research Ethics Board-approved study. Prior to radical prostatectomy, ADC (b value, 600 sec/mm(2)) and T2 maps were obtained by using 1.5-T magnetic resonance (MR) imaging. Twenty-eight peripheral zone (PZ) tumors were reviewed by using whole-mount histologic findings, and regions assessed to contain primarily (>60%) normal PZ tissue were delineated. Tumors were categorized as "sparse" if more than 50% of their cross-sectional areas were these primarily normal PZ regions and were considered "dense" otherwise. Normal PZ tissue was outlined separately on the same section. Tumor and normal tissue outlines were transferred to corresponding ADC and T2 maps, and median values were calculated. Values were compared by using multiple regression analysis. Matched-pair tumor-to-normal tissue differences and log(2)-transformed ratios were assessed by using nonparametric tests.
Thirty-six percent (10 of 28) of tumors were sparse; 64% (18 of 28) were dense. For both overall and intrapatient comparisons, dense tumors had significantly lower ADC and T2 values than normal PZ tissue (P < .05), but no significant differences were observed between sparse tumors and normal tissue. Log(2)-transformed tumor-to-normal tissue ratios were significantly less than zero for dense tumors for both ADC and T2 (P < .01) measurements but not for sparse tumors. Both matched-pair differences and log(2)-transformed ratios were significantly different between sparse and dense tumors (P < .01). ADC and T2 values were moderately correlated (Pearson correlation coefficient range, r = 0.770-0.804).
Sparse prostate tumors have similar ADC and T2 values to those of normal PZ tissue. This may limit MR imaging detection and the assessment of tumor volume of some cancers.
To determine late effects of hematopoietic cell transplantation (HCT) on health problems and health-related quality of life for 10-year survivors.
Four hundred five adults consented to the study ...before HCT. Medical records and standardized self-report measures were maintained prospectively. After 10 years, 137 survivors and nontransplant controls, case-matched on age, sex, and race, completed self-report of medical problems, symptoms, and health-related quality of life.
Survivors and controls had similar rates of hospitalization and most diseases, but survivors reported an average of 3.5 medical problems versus 1.7 for controls (P < .001). Survivors reported more musculoskeletal stiffness, cramps, weakness and joint swelling (P < .001), cataract surgery (P < .001), hepatitis C (P = .004), sexual problems for men (P = .01) and women (P < .001), restrictions in social function (P = .002), memory and attention concerns (P = .003), urinary frequency or leaking (P = .006), use of psychotropic medication (P = .009), and denial of life and health insurance (P < .001). Survivors and controls did not differ in self-reported rates of osteoporosis, hypothyroidism, employment, marital satisfaction, divorce, or psychological health.
Although indistinguishable in many respects, survivors had more medical needs than controls. Health problems were not focused on specific diseases or limited to survivors with readily identifiable risk factors. Musculoskeletal problems require both screening and research into etiologies and effective treatments. Osteoporosis and hypothyroidism may be underdiagnosed. Survivors require screening for sexual problems, urinary frequency, mood and need for antidepressants or benzodiazepines.
Prostate Specific Membrane Antigen (PSMA) positron emission tomography/computed tomography (PET/CT) is becoming established as a standard of care for the (re)staging of high-risk primary and prostate ...cancer recurrence after primary therapy. Despite the favorable performance of this imaging modality with high accuracy in disease detection, the availability of PSMA PET/CT varies across jurisdictions worldwide due to variability in the selection of PSMA PET/CT agent, regulatory approvals and funding. In Canada, PSMA based radiopharmaceuticals are still considered investigational new drug (IND), creating limitations in the deployment of these promising imaging agents. While regulatory approval rests with Health Canada, as a single payer health system, funding for Health Canada approved drugs and devices is decided by Provincial Health Ministries. Ontario Health (Cancer Care Ontario) (OH-CCO) is the agency of the Ministry of Health (MOH) in Ontario responsible for making recommendations to the MOH around the organization and funding of cancer services within Ontario (population of 15 million), and the PET Steering Committee of OH-CCO is responsible for providing recommendations on the introduction of new PET radiopharmaceuticals and indications. For Health Canada approved PET radiopharmaceuticals like 18F-FDG, OH-CCO (on behalf of the MOH) provides coverage based on levels of evidence and specific PET Registries are established to aid in real-world evidence collection to inform OH-CCO regarding emerging PET applications. In the case of PSMA PET/CT, adapting this model to an IND PSMA PET/CT agent, 18F-DCFPyL, necessitated the creation of a hybrid Registry-Study model to leverage the existing OH-CCO Registry structure while respecting the need for a Health Canada Clinical Trials Application (CTA) for the deployment of this agent in the province. Within the first 2 years of the registry, over 1700 men have been imaged resulting in a change in management (compared to pre-PET management plans) in over half of the men imaged. In this article, we describe the organization and deployment of the PSMA PET/CT (PREP) Registry throughout the province to provide access for men with suspected prostate cancer recurrence along with key stakeholder perspectives and preliminary results.
Prostate cancer is one of the leading causes of death from cancer among men in the United States. Currently, high-resolution magnetic resonance imaging (MRI) has been shown to have higher accuracy ...than trans-rectal ultrasound (TRUS) when used to ascertain the presence of prostate cancer. As MRI can provide both morphological and functional images for a tissue of interest, some researchers are exploring the uses of multispectral MRI to guide prostate biopsies and radiation therapy. However, success with prostate cancer localization based on current imaging methods has been limited due to overlap in feature space of benign and malignant tissues using any one MRI method and the interobserver variability. In this paper, we present a new unsupervised segmentation method for prostate cancer detection, using fuzzy Markov random fields (fuzzy MRFs) for the segmentation of multispectral MR prostate images. Typically, both hard and fuzzy MRF models have two groups of parameters to be estimated: the MRF parameters and class parameters for each pixel in the image. To date, these two parameters have been treated separately, and estimated in an alternating fashion. In this paper, we develop a new method to estimate the parameters defining the Markovian distribution of the measured data, while performing the data clustering simultaneously. We perform computer simulations on synthetic test images and multispectral MR prostate datasets to demonstrate the efficacy and efficiency of the proposed method and also provide a comparison with some of the commonly used methods.
INTRODUCTION: Diagnostic assessment programs (DAPs) were implemented in Ontario, Canada, to improve the efficiency of the lung cancer care continuum. We compared the efficiency and effectiveness of ...care provided to patients in DAPs relative to usual care (non-DAPs).
METHODS: Lung cancer patients diagnosed between 2014 and 2016 were identified from the Ontario Cancer Registry. Using administrative databases, we identified various health-care encounters 6 months before diagnosis until the start of treatment and compared utilization patterns, timing, and overall survival between DAP and non-DAP patients.
RESULTS: DAP patients were younger (P < 0.0001), had fewer comorbidities (P = 0.0006), and were more likely to have early-stage disease (36% vs. 25%) than non-DAP patients. Although DAP patients had a similar time until diagnosis as non-DAP patients, the time until treatment was 8.5 days shorter for DAP patients. DAP patients were more likely to receive diagnostic tests and specialist consultations and less likely to have duplicate chest imaging. DAP patients were more likely to receive brain imaging. Among early-stage lung cancers, brain imaging was high (74% for DAP and 67% for non-DAP), exceeding guideline recommendations. After adjustment for clinical and demographic factors, DAP patients had better overall survival than non-DAP patients (hazard ratio HR: 0.79 0.76-0.82), but this benefit was lost after adjusting for emergency presentation (HR: 0.96 0.92-1.00). A longer time until treatment was associated with better overall survival.
Conclusion: DAPs provided earlier treatment and better access to care, potentially improving survival. Quality improvement opportunities include reducing unnecessary or duplicate testing and characterizing patients who are diagnosed emergently.
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