276 research outputs found

    Projective tensor products, injective tensor products, and dual relations on operator spaces.

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    Semisupervised Soft Mumford-Shah Model for MRI Brain Image Segmentation

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    One challenge of unsupervised MRI brain image segmentation is the central gray matter due to the faint contrast with respect to the surrounding white matter. In this paper, the necessity of supervised image segmentation is addressed, and a soft Mumford-Shah model is introduced. Then, a framework of semisupervised image segmentation based on soft Mumford-Shah model is developed. The main contribution of this paper lies in the development a framework of a semisupervised soft image segmentation using both Bayesian principle and the principle of soft image segmentation. The developed framework classifies pixels using a semisupervised and interactive way, where the class of a pixel is not only determined by its features but also determined by its distance from those known regions. The developed semisupervised soft segmentation model turns out to be an extension of the unsupervised soft Mumford-Shah model. The framework is then applied to MRI brain image segmentation. Experimental results demonstrate that the developed framework outperforms the state-of-the-art methods of unsupervised segmentation. The new method can produce segmentation as precise as required

    Effects of Radiation on Optical Fibers

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    Failure of early mycological clearance in HIV-negative cryptococcal meningitis

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    BACKGROUND: Negative cerebrospinal fluid (CSF) cultures at 2 weeks after antifungal treatment (early mycological clearance [EMC]) should be a treatment goal of cryptococcal meningitis (CM). However, EMC in human immunodeficiency virus (HIV)-negative patients with CM is poorly understood. METHODS: We conducted a retrospective review of medical records and 1-year follow-up of 141 HIV-negative patients with CM with an initial positive CSF culture for RESULTS: Of 141 patients, 28 (19.9%) had EMC failure. The 1-year mortality rate was 5.7% (8/141). Multivariate analysis showed that non-amphotericin B (AmB)-based regimens, baseline log CONCLUSIONS: EMC failure in HIV-negative CM is attributed to non-AmB-based therapy and is associated with lo

    Yörünge Fiziği Öğrenimini Uygulamalı bir Kinect Oyunu ile Geliştirme

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    Practicing is very important in the process of learning physics. Experiencing physics laws and observing the phenomenon in the experiments and labs help students learn. However, some contexts like the law of orbits in physics cannot be practiced directly and students can only learn it from animation or drawings. We have designed a Kinect game for students to experience orbital physics and conducted a pilot in a summer camp of Athabasca University's science outreach program to verify the hypotheses include whether the students' attitudes toward computer/video games will affect their perceptions toward the developed Kinect game or not, and whether their performance in the game will be influenced by the lack of prior knowledge of the law of orbits or not. The quantitative analysis results showed that there was a positive correlation between students' gaming performances and what they knew about the relevant physics knowledge. Also, it shows that the students' attitudes toward computer/video games do not affect their perceptions toward the developed Kinect game in terms of its usability.Fizik öğreniminde pratik yapmanın yeri büyüktür. Fizik kanunlarını deneyimlemek ve deneylerle ve laboratuvar ortamında gözlemlemek öğrenmeyi kolaylaştırır. Fakat yörünge kanunu gibi bazı konuların pratik uygulamaları yoktur ve öğrenciler bu konuyu sadece animasyonlar veya çizimler yoluyla öğrenebilirler. Öğrencilerin yörünge fiziğini deneyimleyebilmeleri için bir Kinect oyunu geliştirdik ve Athabasca Üniversitesi’nin yaz kampındaki bilim destek programı çerçevesinde bir pilot çalışma yürüttük. Bu çalışma ile öğrencilerin bilgisayar/video oyunlarına karşı tutumlarının Kinect oyunuyla ilgili algılarını etkileyip etkilemeyeceği ve yörünge kanunuyla ilgili bilgilerinin olmayışının oyun performanslarına etki edip etmeyeceği gibi bazı hipotezleri doğrulamak istedik. Nicel analiz sonuçları öğrencilerin oyun performansı ile konu hakkındaki bilgileri arasında pozitif bir korelasyon olduğunu; ayrıca, öğrencilerin bilgisayar/video oyunlarına karşı tutumlarının Kinect oyununun kullanılabilirliğine ilişkin görüşleri açısından bir etki yaratmadığını göstermiştir

    Ultrathin Few-Layer GeP Nanosheets via Lithiation-Assisted Chemical Exfoliation and Their Application in Sodium Storage

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    2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Ultrathin few-layer materials have attracted intensive research attention because of their distinctive and unique properties. Few-layer GeP (FL-GP) is potentially interesting for application in electronics and optoelectronics because of its appropriate band gap and good stability under ambient conditions. Nevertheless, it is a challenge to achieve ultrathin few-layer or single layer GeP from exfoliation of bulk crystals. Here, a lithiation-assisted chemical exfoliation technique is employed to achieve FL-GP, in which the interlayer spacing can be efficiently enlarged after a preliminary lithium ion intercalation, allowing the bulk crystal to be readily exfoliated in a following ultrasonication. As a result, ultrathin FL-GP is obtained. In a demonstration, the FL-GP/reduced graphene oxide (rGO) demonstrates remarkable sodium storage performance. The FL-GP with a two-dimensional structure shortens the ion transport pathways and alleviates the volume variation during sodiation. Meanwhile, the rGO in the composite improves the conductivity of the whole electrode. The as-prepared FL-GP/rGO electrode exhibits a high capacity of 504.2 mAh g−1 at 100 mA g−1, remarkable rate performance, and superior cycling stability in the half cells. FL-GP/rGO//Na3V2(PO4)3 full cells are also assembled and demonstrated satisfactory electrochemical performance, indicating potential application of the as-prepared anode materials

    Interleukin-10 Inhibits Bone Resorption: A Potential Therapeutic Strategy in Periodontitis and Other Bone Loss Diseases

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    Periodontitis and other bone loss diseases, decreasing bone volume and strength, have a significant impact on millions of people with the risk of tooth loss and bone fracture. The integrity and strength of bone are maintained through the balance between bone resorption and bone formation by osteoclasts and osteoblasts, respectively, so the loss of bone results from the disruption of such balance due to increased resorption or/and decreased formation of bone. The goal of therapies for diseases of bone loss is to reduce bone loss, improve bone formation, and then keep healthy bone density. Current therapies have mostly relied on longterm medication, exercise, anti-inflammatory therapies, and changing of the life style. However there are some limitations for some patients in the effective treatments for bone loss diseases because of the complexity of bone loss. Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine, and recent studies have indicated that IL-10 can contribute to the maintenance of bone mass through inhibition of osteoclastic bone resorption and regulation of osteoblastic bone formation. This paper will provide a brief overview of the role of IL-10 in bone loss diseases and discuss the possibility of IL-10 adoption in therapy of bone loss diseases therapy

    Predictors of lung adenocarcinoma with leptomeningeal metastases: A 2022 targeted-therapy-assisted molGPA model

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    Objective: To explore prognostic indicators of lung adenocarcinoma with leptomeningeal metastases (LM) and provide an updated graded prognostic assessment model integrated with molecular alterations (molGPA). Methods: A cohort of 162 patients was enrolled from 202 patients with lung adenocarcinoma and LM. By randomly splitting data into the training (80%) and validation (20%) sets, the Cox regression and random survival forest methods were used on the training set to identify statistically significant variables and construct a prognostic model. The C-index of the model was calculated and compared with that of previous molGPA models. Results: The Cox regression and random forest models both identified four variables, which included KPS, LANO neurological assessment, TKI therapy line, and controlled primary tumor, as statistically significant predictors. A novel targeted-therapy-assisted molGPA model (2022) using the above four prognostic factors was developed to predict LM of lung adenocarcinoma. The C-indices of this prognostic model in the training and validation sets were higher than those of the lung-molGPA (2017) and molGPA (2019) models. Conclusions: The 2022 molGPA model, a substantial update of previous molGPA models with better prediction performance, may be useful in clinical decision making and stratification of future clinical trials
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