85 research outputs found

    Effect of dependent scattering on the optical properties of Intralipid tissue phantoms

    Get PDF
    The calibration of optical tissue-simulating phantoms remains an open question in spite of the many techniques proposed for accurate measurements of optical properties. As a consequence, a reference phantom with well known optical properties is still missing. As a first step towards a reference phantom we have recently proposed to use dilutions of Intralipid 20%. In this paper we discuss a matter that is commonly ignored when dilutions are prepared, i.e., the possibility of deviations from the simple linear relationships between the optical properties of the dilution and the Intralipid concentration due to the effects of dependent scattering. The results of an experimental investigation showed that dependent scattering does not affect absorption. As for the reduced scattering coefficient the effect can be described adding a term proportional to the square of the concentration. However, for concentrations of interest for tissue optics deviations from linearity remain within about 2%. The experimental investigation also showed that the microphysical properties of Intralipid are not affected by dilution. These results show the possibility to easily obtain a liquid diffusive phantom whose optical properties are known with error smaller than about 1%. Due to the intrinsic limitations of the different techniques proposed for measuring the optical properties it seems difficult to obtain a similar accuracy for solid phantoms

    Untitled [Boy with hat and man with mask]

    No full text
    Rebecca_Drolen__Nashville__TN_February_09__2014_at_0736PMThese images were created as part of the Hughes Remix project, a collaborative endeavor developed by UMBC's Albin O. Kuhn Library Special Collections and the Department of Visual Art to foster creative engagement with archival holdings in conjunction with the 2014 Society for Photographic Education annual conference. UMBC's Special Collections offered a selection of images from the Hughes Company Glass Negatives (http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughes) collection for SPE members and conference attendees to remix, reinvent, reinterpret, and reimagine the images in this collection of Baltimore street scenes, promotional and advertising photographs, businesses, churches, schools, monuments, factories, machinery, and portraits. Images that were created were displayed during the conference as well as on a Tumblr site and are now archived in the Special Collections. Full details of the project can be found at: http://hughes-remix.tumblr.com/overview.The original Hughes Company Glass Negatives collection can be found at: http://contentdm.ad.umbc.edu/cdm/landingpage/collection/hughe

    Modeling Management-Relevant Urban Forest Stand Characteristics to Optimize Carbon Storage and Sequestration

    No full text
    Urban forests are an essential part of adaptation and mitigation solutions for climate change. To understand the relationship between carbon storage, sequestration, and stand density in the most heavily-managed aspect of the urban forest—street trees—we modified the parameters and algorithms of a rural forest dynamics model, the perfect plasticity approximation (PPA), to reflect urban street tree conditions. The main changes in the new street tree PPA are the maintenance of a prescribed stand density via management of recruitment, the possibility of crown-roof overlap, and increased mortality rates. Using the street tree PPA, we explored overall productivity, crown allometry relative to stem diameter, and mortality rate to test each mechanism’s impact on urban street tree carbon storage and sequestration across a gradient of prescribed stand density, with the goal of finding conditions in which street tree carbon storage and sequestration are optimized. We compared the qualitative trends in storage from the street tree PPA to those found in the U.S. Forest Service’s Urban Forest Inventory Analysis data. We found that carbon storage and sequestration increase with prescribed density up to a point where carbon storage and sequestration saturate. Optimized carbon storage and sequestration result from a stand with high productivity, maximized crown allometry relative to stem diameter, and a low mortality rate. These insights can be used to inform urban street tree maintenance strategies that effectively increase carbon storage and sequestration within a given city, such as focusing afforestation campaigns on adequate areas with the lowest street tree densities

    Treatment Equity in the Immunotherapy Era: Options for Patients with Both Autoimmune Disease and GU Cancers

    No full text
    Numerous immunotherapeutic agents, such as immune checkpoint inhibitors (ICIs), have been approved for the treatment of genitourinary (GU) malignancies. While ICIs have improved treatment outcomes and expanded treatment options, they can cause immune-related adverse events (irAEs). The scope of irAEs is broad, and this paper aims to review the rheumatologic side effects associated with immunotherapy drugs approved for bladder cancer and renal cell carcinoma. IrAEs are graded by the common terminology criteria for adverse events (CTCAE), which ranges from 1 to 5. The management of irAEs includes corticosteroids or other immunosuppressive therapies, and it may require discontinuation of immunotherapy. Several real world experience studies suggest that most patients with pre-existing autoimmune diseases treated with ICI did not have to discontinue treatment due to immune-mediated side effects. While data suggest autoimmune side effects are manageable, patients with pre-existing autoimmune diseases are often excluded from immunotherapy clinical trials. Better understanding of these irAEs will improve its safety and expand its use in those with underlying autoimmune disease

    Immunotherapy and Metastatic Renal Cell Carcinoma: A Review of New Treatment Approaches

    No full text
    Introduction: Renal cell carcinomas (RCC) have been treated with immunotherapy for decades; the use of immune checkpoint inhibitors represents the most recent advance. In this review, we compare these new RCC immunotherapies, with a focus on achieving durable complete responses (CR). Review: Sorafenib and sunitinib were the first Food and Drug Administration (FDA)-approved targeted agents for RCC, with sunitinib eventually becoming the standard-of-care agent against which novel therapies are compared. In the last five years, many combination therapies based on the use of immune checkpoint inhibitors (ICIs) and receptor tyrosine kinase inhibitors (TKIs), including ipilimumab/nivolumab, nivolumab/cabozantinib, avelumab/axitinib, pembrolizumab/axitinib, and pembrolizumab/lenvatinib, have demonstrated superior overall survival (OS) and progression-free survival (PFS) compared to sunitinib. Ongoing clinical trials of hypoxia-induced factor-2 alpha (HIF-2a) inhibitors, chimeric antigen receptor T cell (CAR-T) therapy targeting CD70, and other new combination therapies have also shown promise and are currently under investigation. Conclusions: Many new combination therapies are approved for RCC treatment, and CR rates suggest that, in the era of immunotherapy, it may be possible to achieve durable responses and survival benefit in patients with metastatic RCC

    Bidirectional reflectance and specularity of twelve spacecraft thermal control materials

    No full text
    • …
    corecore