112 results match your criteria agent-free method

Quantitative three-dimensional collagen orientation analysis of human meniscus posterior horn in health and osteoarthritis using micro-computed tomography.

Osteoarthritis Cartilage 2021 Feb 13. Epub 2021 Feb 13.

Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland; Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland. Electronic address:

Objective: Knee osteoarthritis (OA) is associated with meniscal degeneration that may involve disorganization of the meniscal collagen fiber network. Our aims were to quantitatively analyze the microstructural organization of human meniscus samples in 3D using micro-computed tomography (μCT), and to compare the local microstructural organization between OA and donor samples.

Method: We collected posterior horns of both medial and lateral human menisci from 10 end-stage medial compartment knee OA patients undergoing total knee replacement (medial & lateral OA) and 10 deceased donors without knee OA (medial & lateral donor). Read More

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February 2021

High-resolution, non-contrast-enhanced magnetic resonance angiography of the wrist, hand and digital arteries using optimized implementation of Cartesian quiescent interval slice selective (QISS) at 1.5 T.

Magn Reson Imaging 2021 05 11;78:58-68. Epub 2021 Feb 11.

Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel University, Kiel, Germany.

Purpose: Non-contrast-enhanced (CE) magnetic resonance angiography (MRA) techniques are of considerable interest for diagnosing vascular diseases in the upper extremities owing to the possibility of repeated examinations, sufficient coverage of the measurement volume, and because possible side effects of administering iodine- or gadolinium-based contrast agents and radiation exposure can be avoided. The aim of this study was to investigate the feasibility of an optimized electrocardiogram (ECG) triggered Cartesian quiescent interval slice selective (QISS) technique for MRA of hand arteries.

Material And Methods: Both hands of 20 healthy volunteers (HVs) were examined using an optimized QISS-MRA pulse sequence at 1. Read More

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Reducing-Agent-Free Convergent Synthesis of Hydroxyimino-Decorated Tetracyclic Fused Cinnolines via Rh-Catalyzed Annulation Using Nitroolefins.

J Org Chem 2021 Feb 21;86(3):2734-2747. Epub 2021 Jan 21.

Department of Chemistry, Birla Institute of Technology and Science, Pilani, Rajasthan 333031, India.

A mild Rh-catalyzed method was developed for the synthesis of hydroxyimino functionalized indazolo[1,2-]cinnolines and phthalazino[2,3-]cinnolines by reductive [4 + 2] annulation between 1-arylindazolones and 2-aryl-2,3-dihydrophthalazine-1,4-diones with varied nitroolefins. The targeted oxime decorated tetracyclic fused cinnolines were synthesized via sequential C-H activation/olefin insertion/reduction under reducing-agent-free conditions. Read More

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February 2021

Mitochondria-Specific Agents for Photodynamic Cancer Therapy: A Key Determinant to Boost the Efficacy.

Adv Healthc Mater 2021 02 25;10(3):e2001240. Epub 2020 Nov 25.

MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, P. R. China.

Mitochondria-targeted photodynamic therapy (Mt-PDT), which enables the photogenerated cytotoxic oxygen species with fatal oxidative damage to block mitochondrial functions, has been considered as a promising method to enhance the anticancer effectiveness. Aiming at the challenges of PDT, in the past few decades, numerous mitochondria-targeting molecular agents have been developed to boost the PDT efficacy via directly destroying the mitochondria or activating mitochondria-mediated cell death pathways. Herein, a review for recent advances of Mt-PDT is highlighted including: mitochondrial targeting design principles and strategies, therapeutic performance of mitochondria-targeted agents-mediated PDT as well as the agent-free Mt-PDT. Read More

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February 2021

Rapid CT-based Estimation of Articular Cartilage Biomechanics in the Knee Joint Without Cartilage Segmentation.

Ann Biomed Eng 2020 Dec 11;48(12):2965-2975. Epub 2020 Nov 11.

Department of Applied Physics, University of Eastern Finland, POB 1627, 70211, Kuopio, Finland.

Knee osteoarthritis (OA) is a painful joint disease, causing disabilities in daily activities. However, there is no known cure for OA, and the best treatment strategy might be prevention. Finite element (FE) modeling has demonstrated potential for evaluating personalized risks for the progression of OA. Read More

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December 2020

A Consensus About the Importance of Ceramide Containing Skincare for Normal and Sensitive Skin Conditions in Neonates and Infants.

J Drugs Dermatol 2020 Aug;19(8):769-776

Background: Neonates and infants are susceptible to skin barrier disruption as their skin anatomically and functionally is still developing. The process of skin acidification plays a vital role in barrier maturation and the activation of enzymes involved in the extracellular processing of stratum corneum lipids. The current consensus paper explores challenges, and current treatment approaches in neonatal and infant normal and sensitive skin and the role of ceramides containing moisturizers. Read More

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Relaxation-compensated CEST (chemical exchange saturation transfer) imaging in breast cancer diagnostics at 7T.

Eur J Radiol 2020 Aug 24;129:109068. Epub 2020 May 24.

Division of Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. Electronic address:

Purpose: To investigate whether fat-corrected and relaxation-compensated amide proton transfer (APT) and guanidyl CEST-MRI enables the detection of signal intensity differences between breast tumors and normal-appearing fibroglandular tissue in patients with newly-diagnosed breast cancer.

Method: Ten patients with newly-diagnosed breast cancer and seven healthy volunteers were included in this prospective IRB-approved study. CEST-MRI was performed on a 7 T-whole-body scanner followed by a multi-Lorentzian fit analysis. Read More

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Removing Subcutaneous Microvessels Using Photo-Mediated Ultrasound Therapy.

Lasers Surg Med 2020 12 11;52(10):984-992. Epub 2020 May 11.

Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Blvd, Ann Arbor, Michigan, 48109.

Background And Objectives: We have developed a novel anti-vascular technique, termed photo-mediated ultrasound therapy (PUT), which utilizes nanosecond duration laser pulses synchronized with ultrasound bursts to remove the microvasculature through cavitation. The objective of the current study is to explore the potential of PUT in removing subcutaneous microvessels.

Study Design/materials And Methods: The auricular blood vessels of two New Zealand white rabbits were treated by PUT with a peak negative ultrasound pressure of 0. Read More

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December 2020

Contrast agent-free synthesis and segmentation of ischemic heart disease images using progressive sequential causal GANs.

Med Image Anal 2020 05 26;62:101668. Epub 2020 Feb 26.

Department of Medical Imaging, Western University, London ON, Canada. Electronic address:

The elimination of gadolinium contrast agent (CA) injections and manual segmentation are crucial for ischemic heart disease (IHD) diagnosis and treatment. In the clinic, CA-based late gadolinium enhancement (LGE) imaging and manual segmentation remain subject to concerns about potential toxicity, interobserver variability, and ineffectiveness. In this study, progressive sequential causal GANs (PSCGAN) are proposed. Read More

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The Effect of Laser and Ultrasound Synchronization in Photo-Mediated Ultrasound Therapy.

IEEE Trans Biomed Eng 2020 12 19;67(12):3363-3370. Epub 2020 Nov 19.

Objective: Photo-mediated ultrasound therapy (PUT) is a novel, non-invasive, agent-free, highly selective, and precise anti-vascular technique. PUT removes microvessels through promoting cavitation activity precisely in targeted microvessels by applying synchronized nanosecond laser pulses and ultrasound bursts. The synchronization between laser and ultrasound is critical to the outcome of PUT. Read More

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December 2020

Noninvasive monitoring of liver metastasis development via combined multispectral photoacoustic imaging and fluorescence diffuse optical tomography.

Int J Biol Sci 2020 12;16(9):1616-1628. Epub 2020 Mar 12.

OPTIMAL, Small animal Imaging Platform, F-38000 Grenoble, France.

molecular imaging in preclinical animal models is a tool of choice for understanding the pathophysiological mechanisms involved in cancer development and for conducting drug development research. Moreover, combining several imaging modalities can provide multifaceted, complementary and cross-validated information. Photoacoustic imaging (PAI) is a promising imaging modality that can reflect blood vasculature and tissue oxygenation as well as detect exogenous molecules, but one shortcoming of PAI is a lack of organic photoacoustic contrast agents capable of providing tumor contrast. Read More

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Organic Structure-directing Agent-free Synthesis for *BEA-type Zeolite Membrane.

J Vis Exp 2020 02 22(156). Epub 2020 Feb 22.

Research Organization for Nano & Life Innovation, Waseda University; Department of Applied Chemistry, Waseda University; Advanced Research Institute for Science and Engineering, Waseda University.

Membrane separation has drawn attention as a novel-energy saving separation process. Zeolite membranes have great potential for hydrocarbon separation in petroleum and petrochemical fields because of their high thermal, chemical, and mechanical strength. A *BEA-type zeolite is an interesting membrane material because of its large pore size and wide Si/Al range. Read More

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February 2020

In situ growth of nanoflake and nanoflower-like Ni hydrated hydroxide on the surface of Ni foam as a free-standing electrode for high-performance phosphate detection.

J Hazard Mater 2020 06 15;392:122313. Epub 2020 Feb 15.

State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 210009, PR China; WA School of Mines: Minerals, Energy and Chemical Engineering (WASM-MECE), Curtin University, Perth, Western Australia, 6845 Australia. Electronic address:

Environmental pollution has always been a global concern, e.g. water eutrophication caused by the high concentrations of phosphorous. Read More

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Magnetic resonance microscopy and correlative histopathology of the infarcted heart.

Sci Rep 2019 12 27;9(1):20017. Epub 2019 Dec 27.

Laboratory of Metabolomics, Institute of Health Research-INCLIVA, Valencia, Spain.

Delayed enhancement cardiovascular magnetic resonance (MR) is the gold-standard for non-invasive assessment after myocardial infarction (MI). MR microscopy (MRM) provides a level of detail comparable to the macro objective of light microscopy. We used MRM and correlative histopathology to identify infarct and remote tissue in contrast agent-free multi-sequence MRM in swine MI hearts. Read More

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December 2019

Super-resolution localization photoacoustic microscopy using intrinsic red blood cells as contrast absorbers.

Light Sci Appl 2019 20;8:103. Epub 2019 Nov 20.

Departments of Creative IT Engineering, Electrical Engineering, Mechanical Engineering, and Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673 Republic of Korea.

Photoacoustic microscopy (PAM) has become a premier microscopy tool that can provide the anatomical, functional, and molecular information of animals and humans in vivo. However, conventional PAM systems suffer from limited temporal and/or spatial resolution. Here, we present a fast PAM system and an agent-free localization method based on a stable and commercial galvanometer scanner with a custom-made scanning mirror (L-PAM-GS). Read More

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November 2019

Non-contrast enhanced diagnosis of acute myocarditis based on the 17-segment heart model using 2D-feature tracking magnetic resonance imaging.

Magn Reson Imaging 2020 01 9;65:155-165. Epub 2019 Nov 9.

Department for Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Campus Kiel, Germany.

Purpose: The aim of this study was to investigate the diagnostic value of myocardial deformation analysis based on the 17-segment heart model using non-contrast enhanced (CE) 2D tissue feature tracking (2D-FT) technique.

Material And Methods: Seventy patients with suspected myocarditis underwent a cardiovascular magnetic resonance (CMR) examination at 1.5 Tesla. Read More

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January 2020

Physicochemical Trapping of Neurotransmitters in Polymer-Mediated Gold Nanoparticle Aggregates for Surface-Enhanced Raman Spectroscopy.

Anal Chem 2019 08 8;91(15):9554-9562. Epub 2019 Jul 8.

Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States.

Because of the sharp distance dependence of surface-enhanced Raman spectroscopy (SERS), analyte molecules that do not exhibit strong affinity for Au/Ag often elude detection. New methods of integrating such analytes with SERS substrates are required to circumvent this limitation and expand the sensitivity of SERS to new molecules and applications. We communicate here a solution-phase, capture agent-free method of aggregating Au nanospheres in the presence of five neurotransmitters (dopamine, epinephrine, norepinephrine, serotonin, and histamine) and preventing sedimentation by encapsulating the aggregated nanospheres with polyvinylpyrrolidone, thereby trapping the neurotransmitters in close proximity to the Au nanospheres and enabling SER detection. Read More

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Separation of Natural Collagen Crosslinks Using Buffer and Ion-pairing Agent Free Solvents on Silica Hydride Column for Mass Spectrometry Detection.

Bio Protoc 2019 May 5;9(9):e3224. Epub 2019 May 5.

Department of Chemistry, San Jose State University, San Jose, CA 95112, USA.

In this protocol we describe the separation of collagen crosslinks in biological tissues and samples including skin, tendon, cartilage, bone and urine. The existing methods use either cation exchange chromatography followed by post-column derivatization with ninhydrin or reverse phase chromatography with mass spectrometry detection. The cation exchange chromatography method has limited sensitivity and long run times while reverse phase chromatography requires strong ion-pairing. Read More

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[Contrast-agent free imaging of the prostate : Ready for clinical practice?]

Radiologe 2019 Jun;59(6):503-509

Universitätsklinik für Radiologie und Nuklearmedizin, Medizinische Universität Wien & AKH-Wien, Währinger Gürtel 18-20, Ebene 7F, 1090, Wien, Österreich.

Background: Multiparametric MRI (mpMRI) is currently the most accurate imaging modality for detection and local staging of prostate cancer (PCa). Disadvantages of this modality are high costs, time consumption and the need for a contrast medium.

Aims: The aim of the work was to provide an overview of the current state of fast and contrast-free MRI imaging of the prostate. Read More

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[Contrast agent-free breast MRI : Advantages and potential disadvantages].

Radiologe 2019 Jun;59(6):510-516

Universitätsklinik für Radiologie und Nuklearmedizin, Allgemeine und Kinderradiologie, Allgemeines Krankenhaus, Medizinischen Universität Wien, Währinger Gürtel 18-20, 1090, Wien, Österreich.

Background: Contrast-enhanced breast magnetic resonance imaging (MRI) is the most sensitive method for detection of breast cancer. The further spread of breast MRI is limited by the complicated examination procedure and the need for intravenously administered contrast media.

Objectives: Can diffusion-weighted imaging (DWI) replace contrast-enhanced sequences to achieve an unenhanced breast MRI examination?

Materials And Methods: Narrative review and meta-analytic assessment of previously published studies. Read More

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Photoacoustic imaging for the evaluation of early tumor response to antivascular treatment.

Quant Imaging Med Surg 2019 Feb;9(2):160-170

Department of Medical Imaging, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China.

Background: Photoacoustic imaging (PAI) provides real-time noninvasive and contrast agent-free monitoring of the concentrations of some endogenous compounds related to tumor vascularization and oxygenation. In this study, we used PAI to noninvasively evaluate tumor responses to antiangiogenic therapy.

Methods: In vivo studies were performed with the approval of our institutional animal ethics committee. Read More

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February 2019

Cryoprotectant-free cryopreservation of mammalian cells by superflash freezing.

Proc Natl Acad Sci U S A 2019 04 1;116(16):7738-7743. Epub 2019 Apr 1.

Division of Pharmacology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan.

Cryopreservation is widely used to maintain backups of cells as it enables the semipermanent storage of cells. During the freezing process, ice crystals that are generated inside and outside the cells can lethally damage the cells. All conventional cryopreservation methods use at least one cryoprotective agent (CPA) to render water inside and outside the cells vitreous or nanocrystallized (near-vitrification) without forming damaging ice crystals. Read More

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Noninvasive Contrast-Free 3D Evaluation of Tumor Angiogenesis with Ultrasensitive Ultrasound Microvessel Imaging.

Sci Rep 2019 03 20;9(1):4907. Epub 2019 Mar 20.

Department of Radiology, Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN, USA.

Ultrasound microvessel imaging (UMI), when applied with ultrafast planewave acquisitions, has demonstrated superior blood signal sensitivity in comparison to conventional Doppler imaging. Here we propose a high spatial resolution and ultra-sensitive UMI that is based on conventional line-by-line high-frequency ultrasound imagers and singular value decomposition (SVD) clutter filtering for the visualization and quantification of tumor microvasculature and perfusion. The technique was applied to a chicken embryo tumor model of renal cell carcinoma that was treated with two FDA-approved anti-angiogenic agents at clinically relevant dosages. Read More

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Imaging endogenous macrophage iron deposits reveals a metabolic biomarker of polarized tumor macrophage infiltration and response to CSF1R breast cancer immunotherapy.

Sci Rep 2019 01 29;9(1):857. Epub 2019 Jan 29.

Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.

Iron deposits are a phenotypic trait of tumor-associated macrophages (TAMs). Histological iron imaging and contrast-agent free magnetic resonance imaging (MRI) can detect these deposits, but their presence  in human cancer, and correlation with immunotherapeutic response is largely untested. Here, primarily using these iron imaging approaches, we evaluated the spatial distribution of polarized macrophage populations containing high endogenous levels of iron in preclinical murine models and human breast cancer, and used them as metabolic biomarkers to correlate TAM infiltration with response to immunotherapy in preclinical trials. Read More

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January 2019

Fabrication of an Anti-Reflective and Super-Hydrophobic Structure by Vacuum Ultraviolet Light-Assisted Bonding and Nanoscale Pattern Transfer.

Micromachines (Basel) 2018 Apr 15;9(4). Epub 2018 Apr 15.

Department of Mechanical and Control Engineering, Tokyo Institute of Technology, Tokyo, 1528552, Japan.

The application of subwavelength, textured structures to glass surfaces has been shown to reduce reflectivity and also results in self-cleaning due to super-hydrophobicity. However, current methods of producing such textures are typically either expensive or difficult to scale up. Based on prior work by the authors, the present study employed a combination of vacuum ultraviolet (VUV) light-assisted bonding and release agent-free pattern transfer to fabricate a moth-eye texture on a glass substrate. Read More

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An improved "ion pairing agent free" HPLC-RP method for testing cAMP Phosphodiesterase activity.

Talanta 2019 Jan 18;192:314-316. Epub 2018 Sep 18.

Department of Biochemistry and Molecular Biology-A, Faculty of Biology, University of Murcia - Regional Campus of International Excellence "Campus Mare Nostrum", Campus de Espinardo, 30071 Murcia, Spain. Electronic address:

Current HPLC methods for analyzing cAMP Phosphodiesterase activity (PDE) use salts, limiting the life of the columns. For this reason, we have developed an improved "ion pairing agent free" method, using a simple 150 mm C18-hydro column at 30 °C and two phases: (a) water with 0.1% acetic acid and (b) 85/15 w/w MeOH/tetrahydrofuran with 0. Read More

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January 2019

Update on imaging in rheumatic diseases: cartilage.

Clin Exp Rheumatol 2018 Sep-Oct;36 Suppl 114(5):139-144. Epub 2018 Oct 1.

Department and Hiller-Research-Unit of Rheumatology, Heinrich-Heine-University Dusseldorf, Germany.

In recent years, the role of articular cartilage for understanding pathogenesis as well as for clinical research has become increasingly important. Whereas previously cartilage could only be assessed invasively, various imaging procedures are available for its evaluation now. Although still widely used, conventional radiography bears significant limitations since it assesses cartilage indirectly by joint space width. Read More

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January 2019

Stationary phase based on cellulose dodecanoate physically immobilized on silica particles for high-performance liquid chromatography.

J Chromatogr A 2018 Oct 23;1572:72-81. Epub 2018 Aug 23.

Instituto de Ciências Exatas e Naturais do Pontal, Universidade Federal de Uberlândia, 38304-402 Ituiutaba, MG, Brazil. Electronic address:

The chemical agent free preparation of a stationary phase using a natural macromolecule was the focus of this paper. Thermal immobilization of cellulose dodecanoate on silica particles was used for the preparation of a stationary phase without the use of chemical reagents. Cellulose modification was performed to produce a hydrophobic macromolecule with solubility in common organic solvents. Read More

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October 2018

An improved, rapid competitive ELISA using a novel conserved 3B epitope for the detection of serum antibodies to foot-and-mouth disease virus.

J Vet Diagn Invest 2018 09 19;30(5):699-707. Epub 2018 Jun 19.

U.S. Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit (Rieder) Plum Island Animal Disease Center, Greenport, NY.

The highly contagious foot-and-mouth disease virus (FMDV) afflicts cloven-hoofed animals, resulting in significant costs because of loss of trade and recovery from disease. We developed a sensitive, specific, and rapid competitive ELISA (cELISA) to detect serum antibodies to FMDV. The cELISA utilized a monoclonal blocking antibody specific for a highly conserved FMDV nonstructural 3B epitope, a recombinant mutant FMDV 3ABC coating protein, and optimized format variables including serum incubation for 90 min at 20-25°C. Read More

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September 2018