24 results match your criteria: "The Johns Hopkins University Whiting School of Engineering[Affiliation]"

The Challenges and Opportunities in Pediatric Medical Device Innovation: Monitoring Devices.

Ann Thorac Surg

December 2024

Division of Pediatric Cardiac Surgery, Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland. Electronic address:

Background: Medical device innovation and development for pediatric care lags behind that of adults. With higher technical risks, challenges in accumulating data, smaller market sizes, and limited return on investment, there is less incentive for pediatric device development. Consequently, translation of medical devices specifically designed to improve pediatric care is limited.

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Objective: We hypothesized that learning through multiple sensory modalities would improve knowledge recall and recognition in orthopedic surgery residents and medical students.

Design: We developed a virtual study assistant, named Socratic Artificial Intelligence Learning (SAIL), based on a custom-built natural language processing algorithm. SAIL draws from practice questions approved by the American Board of Orthopaedic Surgery and quizzes users through a conversational, voice-enabled Web interface.

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Autokinesis Reveals a Threshold for Perception of Visual Motion.

Neuroscience

April 2024

Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. Electronic address:

In natural viewing conditions, the brain can optimally integrate retinal and extraretinal signals to maintain a stable visual perception. These mechanisms, however, may fail in circumstances where extraction of a motion signal is less viable such as impoverished visual scenes. This can result in a phenomenon known as autokinesis in which one may experience apparent motion of a small visual stimulus in an otherwise completely dark environment.

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For the improved delivery of cancer therapeutics and imaging agents, the conjugation of cell-penetrating peptides (CPPs) increases the cellular uptake and water solubility of agents. Among the various CPPs, arginine-rich peptides have been the most widely used. Combining CPPs with enzyme-responsive peptides presents an innovative strategy to target specific intracellular enzymes in cancer cells and when combined with the appropriate click chemistry can enhance theranostic drug delivery through the formation of intracellular self-assembled nanostructures.

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Current methods for assessing technical skill in cataract surgery.

J Cataract Refract Surg

February 2021

From the The Wilmer Eye Institute, Johns Hopkins University School of Medicine (Alnafisee, Zafar, Sikder), Baltimore, and the Department of Computer Science, Malone Center for Engineering in Healthcare, The Johns Hopkins University Whiting School of Engineering (Vedula), Baltimore, Maryland, USA.

Surgery is a major source of errors in patient care. Preventing complications from surgical errors in the operating room is estimated to lead to reduction of up to 41 846 readmissions and save $620.3 million per year.

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Imaging of Composite Hydrogel Scaffold Degradation Using CEST MRI and Two-Color NIR Imaging.

Adv Funct Mater

September 2019

Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, the Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.

Hydrogel scaffolding of stem cells is a promising strategy to overcome initial cell loss and manipulate cell function post-transplantation. Matrix degradation is a requirement for downstream cell differentiation and functional tissue integration, which determines therapeutic outcome. Therefore, monitoring of hydrogel degradation is essential for scaffolded cell replacement therapies.

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Fluorocapsules allow in vivo monitoring of the mechanical stability of encapsulated islet cell transplants.

Biomaterials

November 2019

Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Department of Chemical & Biomolecular Engineering, The Johns Hopkins University Whiting School of Engineering, Baltimore, MD, 21218, USA; Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. Electronic address:

Clinical trials that have used encapsulated islet cell therapy have been few and overall disappointing. This is due in part to the lack of suitable methods to monitor the integrity vs. rupture of transplanted microcapsules over time.

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A brain-computer interface (BCI) is a technology that uses neural features to restore or augment the capabilities of its user. A BCI for speech would enable communication in real time via neural correlates of attempted or imagined speech. Such a technology would potentially restore communication and improve quality of life for locked-in patients and other patients with severe communication disorders.

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We present an improved type of food gum (salecan) based hydrogels for oral delivery of insulin. Structural hydrogel formation was assessed with Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. We found that the hydrogel modulus, morphology, and swelling properties can be controlled by varying the salecan dose during hydrogel formation.

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Quantification of motor neuron loss and muscular atrophy in ricin-induced focal nerve injury.

J Neurosci Methods

October 2018

Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Dept. of Chemical & Biomolecular Engineering, The Johns Hopkins University Whiting School of Engineering, Baltimore, MD, 21205, USA; Dept. of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Dept of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA. Electronic address:

Background: Intrasciatic nerve injection of the Ricinus communis agglutinin (RCA or ricin) causes degeneration of motor neurons (MNs) with functional deficits, such as those that occur in amyotrophic lateral sclerosis (ALS). The objective of this study was to develop a new comprehensive platform for quantitative evaluation of MN loss, muscular atrophy and behavioral deficits using different ricin injection regimens.

New Method: Fluorogold (FG)-guided stereological quantification of MNs, in vivo magnetic resonance imaging (MRI) of muscular atrophy, and CatWalk behavioral testing were used to evaluate the outcome of rats treated with different ricin regimens (RCA60 0.

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Neurological disorders are a major threat to public health. Stem cell-based regenerative medicine is now a promising experimental paradigm for its treatment, as shown in pre-clinical animal studies. Initial attempts have been on the replacement of neuronal cells only, but glial progenitors (GPs) are now becoming strong alternative cellular therapeutic candidates to replace oligodendrocytes and astrocytes as knowledge accumulates about their important emerging role in various disease processes.

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Two decades of dendrimers as versatile MRI agents: a tale with and without metals.

Wiley Interdiscip Rev Nanomed Nanobiotechnol

May 2018

The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Dendrimers or dendritic polymers are a class of compounds with great potential for nanomedical use. Some of their properties, including their rigidity, low polydispersity and the ease with which their surfaces can be modified make them particularly well suited for use as MRI diagnostic or theranostic agents. For the past 20 years, researchers have recognized this potential and refined dendrimer formulations to optimize these nanocarriers for a host of MRI applications, including blood pool imaging agents, lymph node imaging agents, tumor-targeted theranostic agents and cell tracking agents.

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The loss of oligodendrocytes after stroke is one of the major causes of secondary injury. Glial-restricted progenitors (GRPs) have remylenating potential after intraparenchymal cerebral transplantation. The intraarterial (IA) injection route is an attractive gateway for global brain delivery, but, after IA infusion, naive GRPs fail to bind to the cerebral vasculature.

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Objective Assessment of Surgical Technical Skill and Competency in the Operating Room.

Annu Rev Biomed Eng

June 2017

Malone Center for Engineering in Healthcare, Department of Computer Science, The Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland 21218; email:

Training skillful and competent surgeons is critical to ensure high quality of care and to minimize disparities in access to effective care. Traditional models to train surgeons are being challenged by rapid advances in technology, an intensified patient-safety culture, and a need for value-driven health systems. Simultaneously, technological developments are enabling capture and analysis of large amounts of complex surgical data.

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Co-transplantation of syngeneic mesenchymal stem cells improves survival of allogeneic glial-restricted precursors in mouse brain.

Exp Neurol

January 2016

Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Chemical & Biomolecular Engineering, The Johns Hopkins University Whiting School of Engineering, Baltimore, MD 21218, USA; Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Electronic address:

Loss of functional cells from immunorejection during the early post-transplantation period is an important factor that reduces the efficacy of stem cell-based therapies. Recent studies have shown that transplanted mesenchymal stem cells (MSCs) can exert therapeutic effects by secreting anti-inflammatory and pro-survival trophic factors. We investigated whether co-transplantation of MSCs could improve the survival of other transplanted therapeutic cells.

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Tissue engineering using mesenchymal stem cells (MSCs) holds great promise for regenerating critically sized bone defects. While the bone marrow-derived MSC is the most widely studied stromal/stem cell type for this application, its rarity within bone marrow and painful isolation procedure have motivated investigation of alternative cell sources. Adipose-derived stromal/stem cells (ASCs) are more abundant and more easily procured; furthermore, they also possess robust osteogenic potency.

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Label-free in vivo molecular imaging of underglycosylated mucin-1 expression in tumour cells.

Nat Commun

March 2015

1] Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA [2] Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, the Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA [3] Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA [4] F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21205, USA [5] Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA [6] Department of Chemical &Biomolecular Engineering, The Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland 21218, USA.

Alterations in mucin expression and glycosylation are associated with cancer development. Underglycosylated mucin-1 (uMUC1) is overexpressed in most malignant adenocarcinomas of epithelial origin (for example, colon, breast and ovarian cancer). Its counterpart MUC1 is a large polymer rich in glycans containing multiple exchangeable OH protons, which is readily detectable by chemical exchange saturation transfer (CEST) MRI.

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Polymeric nanoparticles represent a form of targeted therapy due to their ability to passively accumulate within the tumor interstitium via the enhanced permeability and retention (EPR) effect. We used a combined approach to decorate the surface of a nanoparticle with a urea-based small-molecule peptidomimetic inhibitor of prostate specific membrane antigen (PSMA). PSMA is expressed by normal and malignant prostate epithelial cells and by the neovasculature of almost all solid tumors.

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Large combinatorial libraries of random peptides have been used for a variety of applications that include analysis of protein-protein interactions, epitope mapping, and drug targeting. The major obstacle in screening these libraries is the loss of specific but low affinity binding peptides during washing steps. Loss of these specific binders often results in isolation of peptides that bind nonspecifically to components used in the selection process.

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Background: Intraprostatic PSMA targeted prodrugs/protoxins are under development in our laboratory. Future toxicologic studies of these therapies require identification of animal models that express PSMA within the prostate.

Method: PSMA enzymatic activity and protein expression was determined.

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A 3D Monte Carlo analysis of the role of dyadic space geometry in spark generation.

Biophys J

March 2006

Whitaker Institute for Biomedical Engineering and Department of Biomedical Engineering, The Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland 21218, USA.

In multiple biological systems, vital intracellular signaling processes occur locally in minute periplasmic subspaces often referred to as signaling microdomains. The number of signaling molecules in these microdomains is small enough to render the notion of continuous concentration changes invalid, such that signaling events are better described using stochastic rather than deterministic methods. Of particular interest is the dyadic cleft in the cardiac myocyte, where short-lived, local increases in intracellular Ca2+ known as Ca2+ sparks regulate excitation-contraction coupling.

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Mechanisms of excitation-contraction coupling in an integrative model of the cardiac ventricular myocyte.

Biophys J

January 2006

The Center for Cardiovascular Bioinformatics and Modeling and The Whitaker Biomedical Engineering Institute, The Johns Hopkins University Whiting School of Engineering and School of Medicine, Baltimore, Maryland, USA.

It is now well established that characteristic properties of excitation-contraction (EC) coupling in cardiac myocytes, such as high gain and graded Ca(2+) release, arise from the interactions that occur between L-type Ca(2+) channels (LCCs) and nearby ryanodine-sensitive Ca(2+) release channels (RyRs) in localized microdomains. Descriptions of Ca(2+)-induced Ca(2+) release (CICR) that account for these local mechanisms are lacking from many previous models of the cardiac action potential, and those that do include local control of CICR are able to reconstruct properties of EC coupling, but require computationally demanding stochastic simulations of approximately 10(5) individual ion channels. In this study, we generalize a recently developed analytical approach for deriving simplified mechanistic models of CICR to formulate an integrative model of the canine cardiac myocyte which is computationally efficient.

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