Publications by authors named "Martin Charles"

140 Publications

Predicting trends in the quality of state-of-the-art neural networks without access to training or testing data.

Nat Commun 2021 07 5;12(1):4122. Epub 2021 Jul 5.

ICSI and Department of Statistics, University of California at Berkeley, Berkeley, CA, USA.

In many applications, one works with neural network models trained by someone else. For such pretrained models, one may not have access to training data or test data. Moreover, one may not know details about the model, e.g., the specifics of the training data, the loss function, the hyperparameter values, etc. Given one or many pretrained models, it is a challenge to say anything about the expected performance or quality of the models. Here, we address this challenge by providing a detailed meta-analysis of hundreds of publicly available pretrained models. We examine norm-based capacity control metrics as well as power law based metrics from the recently-developed Theory of Heavy-Tailed Self Regularization. We find that norm based metrics correlate well with reported test accuracies for well-trained models, but that they often cannot distinguish well-trained versus poorly trained models. We also find that power law based metrics can do much better-quantitatively better at discriminating among series of well-trained models with a given architecture; and qualitatively better at discriminating well-trained versus poorly trained models. These methods can be used to identify when a pretrained neural network has problems that cannot be detected simply by examining training/test accuracies.
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http://dx.doi.org/10.1038/s41467-021-24025-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8257709PMC
July 2021

First Clinical Experience With Single-Port Robotic Transanal Minimally Invasive Surgery: Phase II Trial of the Initial 26 Cases.

Dis Colon Rectum 2021 Aug;64(8):1003-1013

Colorectal Center at Lankenau Medical Center, Main Line Health, Lankenau Institute of Medical Research, Department of Colorectal Surgery, Lankenau Medical Center, Wynnewood, Pennsylvania.

Background: Many transanal platforms have been developed to address the challenge of reach and vision when operating transanally. The single-port robot was specifically designed for narrow-aperture surgery and is a promising platform for minimally invasive transanal surgery.

Objective: The purpose of this phase II trial is to evaluate the safety and feasibility of the initial clinical experience with single-port robot transanal minimally invasive surgery.

Design: In a prospective phase II trial, patients with rectal neoplasms eligible for local excision were enrolled for single-port robotic transanal minimally invasive surgery.

Setting: The study was conducted between October 2018 and March 2020 at a tertiary referral hospital.

Patients/intervention: Twenty-six consecutive patients underwent single-port robotic transanal minimally invasive surgery resection of rectal lesions.

Main Outcome Measures: The primary end point of the study was the efficacy and safety of single-port robotic transanal minimally invasive surgery.

Results: There were 13 men and 13 women, with an average lesion size of 2.9 cm (range, 1.0-6.0 cm) and average level of 4.8 cm from the anorectal ring (range, 0-30 cm). Ten patients had a preoperative diagnosis of adenocarcinoma, 7 of whom received neoadjuvant chemoradiation (range, 4500-5580 cGy with concurrent oral capecitabine). Eighty-eight percent of cases were completed by single-port robotic transanal minimally invasive surgery; 2 were converted to transanal endoscopic microsurgery, and 1 patient underwent a low anterior resection. There were no piecemeal extractions, and all margins were negative on final pathology. There were no mortalities, and the morbidity rate was 15.4%. There have been no local recurrences, with a mean follow-up of 5.8 months (range, 0-15.9 months).

Limitations: The study was limited by small sample size, short-term follow up, and a single-surgeon experience.

Conclusion: Single-port robotic transanal minimally invasive surgery procedures are safe and feasible in patients with select benign and malignant rectal lesions. Future trials will need to evaluate the long-term safety and efficacy of single-port robotic transanal minimally invasive surgery. See Video Abstract at http://links.lww.com/DCR/B605.

Primera Experiencia Clnica Con Ciruga Mnimamente Invasiva Transanal Robtica De Puerto Nico Ensayo De Fase Ii De Los Casos Iniciales: ANTECEDENTES:Se han desarrollado muchas plataformas transanales para abordar el desafío del alcance y la visión cuando se opera de manera transanal. El robot de un solo puerto fue diseñado específicamente para la cirugía de apertura estrecha y es una plataforma prometedora para la cirugía transanal mínimamente invasiva.OBJETIVO:El propósito de este ensayo de fase II es evaluar la seguridad y viabilidad de la experiencia clínica inicial con la cirugía mínimamente invasiva transanal con robot de puerto único.DISEÑO:En un ensayo prospectivo de fase II, los pacientes con neoplasias rectales elegibles para la escisión local se inscribieron para la cirugía mínimamente invasiva transanal robótica de puerto único.AJUSTE:El estudio se realizó entre octubre de 2018 y marzo de 2020 en un hospital de referencia terciario.PACIENTES / INTERVENCIÓN:Veintiséis pacientes consecutivos fueron sometidos a cirugía mínimamente invasiva transanal robótica de puerto único para resección de lesiones rectales.PRINCIPALES MEDIDAS DE RESULTADO:El criterio de valoración principal del estudio fue la eficacia y seguridad de la cirugía mínimamente invasiva transanal robótica de puerto único.RESULTADOS:Hubo 13 hombres y 13 mujeres, con un tamaño de lesión promedio de 2.9 cm (rango 1.0-6.0 cm) y un nivel promedio de 4.8 cm del anillo anorrectal (rango 0-30 cm). Diez pacientes tenían un diagnóstico preoperatorio de adenocarcinoma, 7 de los cuales recibieron quimiorradiación neoadyuvante (rango 4500-5580 cGy con capecitabina oral concurrente). El 88% de los casos se completaron mediante cirugía mínimamente invasiva transanal robótica de puerto único; 2 se convirtieron a microcirugía endoscópica transanal y 1 se sometió a una resección anterior baja. No hubo extracciones parciales y todos los márgenes fueron negativos en la patología final. No hubo mortalidad y una tasa de morbilidad del 15,4%. No ha habido recidivas locales, con un seguimiento medio de 5,8 meses (rango 0-15,9 meses).LIMITACIONES:El estudio estuvo limitado por un tamaño de muestra pequeño, un seguimiento a corto plazo y la experiencia de un solo cirujano.CONCLUSIÓN:Los procedimientos de cirugía mínimamente invasiva transanal robótica de puerto único son seguros y factibles en pacientes con lesiones rectales benignas y malignas seleccionadas. Los ensayos futuros deberán evaluar la seguridad y eficacia a largo plazo de la cirugía mínimamente invasiva transanal robótica de puerto único. Consulte Video Resumen en http://links.lww.com/DCR/B605. (Traducción-Dr. Eduardo Londoño-Schimmer).
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http://dx.doi.org/10.1097/DCR.0000000000001999DOI Listing
August 2021

Near-Infrared Reflectance Imaging to Detect an Incipient Retinal Arterial Macroaneurysm.

Case Rep Ophthalmol 2021 Jan-Apr;12(1):150-153. Epub 2021 Apr 12.

Retina Division, Centro Oftalmológico Dr. Charles, Ciudad Autónoma de Buenos Aires, Argentina.

Retinal arterial macroaneurysms (RAM) are characterized by a saccular or fusiform dilation of the retinal artery wall. An 84-year-old Caucasian woman with a medical history of poorly controlled hypertension was diagnosed with RAM in the left eye. Previous macular spectral-domain optical coherence tomography images from the patient were available for comparison. Near-infrared reflectance imaging (NIR-R), taken 3 years before, demonstrated a cuff-type thickening of the arteriolar vessel wall at the site of the current complicated RAM that had gone completely unnoticed. These findings suggest that NIR-R may contribute to the detection of early damage of the arterial wall that may predict arterial aneurysm formation in hypertensive patients.
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http://dx.doi.org/10.1159/000513344DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8077541PMC
April 2021

Understanding Musical Predictions With an Embodied Interface for Musical Machine Learning.

Front Artif Intell 2020 3;3. Epub 2020 Mar 3.

Department of Informatics, University of Oslo, Oslo, Norway.

Machine-learning models of music often exist outside the worlds of musical performance practice and abstracted from the physical gestures of musicians. In this work, we consider how a recurrent neural network (RNN) model of simple music gestures may be integrated into a physical instrument so that predictions are sonically and physically entwined with the performer's actions. We introduce EMPI, an embodied musical prediction interface that simplifies musical interaction and prediction to just one dimension of continuous input and output. The predictive model is a mixture density RNN trained to estimate the performer's next physical input action and the time at which this will occur. Predictions are represented sonically through synthesized audio, and physically with a motorized output indicator. We use EMPI to investigate how performers understand and exploit different predictive models to make music through a controlled study of performances with different models and levels of physical feedback. We show that while performers often favor a model trained on human-sourced data, they find different musical affordances in models trained on synthetic, and even random, data. Physical representation of predictions seemed to affect the length of performances. This work contributes new understandings of how musicians use generative ML models in real-time performance backed up by experimental evidence. We argue that a constrained musical interface can expose the affordances of embodied predictive interactions.
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http://dx.doi.org/10.3389/frai.2020.00006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7861300PMC
March 2020

Biological nanopores elucidate the differences between isomers of mercaptobenzoic-capped gold clusters.

Phys Chem Chem Phys 2021 Apr 13;23(13):7938-7947. Epub 2021 Jan 13.

Department of Physics, Virginia Commonwealth University, Richmond, VA 23284, USA.

Identification of isomers using traditional mass spectroscopy methods has proven an interesting challenge due to their identical mass to charge ratios. This proves particularly consequential for gold clusters, as subtle variations in the ligand and cluster structure can have drastic effects on the cluster functionalization, solubility, and chemical properties. Biological nanopores have proven an effective tool in identifying subtle variations at the single molecule limit. This paper reports on the ability of an α-hemolysin (αHL) pore to differentiate between para-, meta-, and ortho- (p-, m-, and o-, respectively) mercaptobenzoic acid ligands attached to gold clusters at the single cluster limit. Detecting differences between p-MBA and m-MBA requires pH-dependent studies that illustrate the role inter-ligand binding plays in stabilizing m-MBA-capped clusters. Additionally, this paper investigates the difference in behavior for these clusters when isolated, and when surrounded by small ligand-Au complexes (AuL, n = 0, 1, 2… and m = 1, 2,…) that are present following cluster synthesis. It is found that continuous exposure of clusters to freely diffusing ligand complexes stabilizes the clusters, while isolated clusters either disintegrate or exit the nanopore in seconds. This has implications for long term cluster stability.
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http://dx.doi.org/10.1039/d0cp05671eDOI Listing
April 2021

Previous oil exposure alters Gulf Killifish oil avoidance behavior.

PeerJ 2020 18;8:e10587. Epub 2020 Dec 18.

Louisiana Universities Marine Consortium, Chauvin, LA, United States of America.

Oil spills threaten the structure and function of ecological communities. The spill was predicted to have catastrophic consequences for nearshore fishes, but field studies indicate resilience in populations and communities. Previous research indicates many marsh fishes exhibit avoidance of oil contaminated areas, representing one potential mechanism for this resilience. Here, we test whether prior oil exposure of Gulf killifish alters this avoidance response. Using choice tests between unoiled and oiled sediments at one of three randomized concentrations (low: 0.1 L oil m, medium: 0.5 L oil m, or high: 3.0 L oil m), we found that, even at low prior exposure levels, killifish lose recognition of oiled sediments compared to control, unexposed fish. Preference for unoiled sediments was absent across all oil concentrations after oil exposure, and some evidence for preference of oiled sediments at high exposure was demonstrated. These results highlight the lack of response to toxic environments in exposed individuals, indicating altered behavior despite organism survival. Future research should document additional sublethal consequences that affect ecosystem and food web functioning.
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http://dx.doi.org/10.7717/peerj.10587DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7751417PMC
December 2020

Intravascular ultrasound in the diagnosis and treatment of central venous diseases.

Vasa 2021 Jan 3;50(1):2-10. Epub 2020 Nov 3.

Section of Interventional Radiology, Imaging Institute, Cleveland Clinic Main Campus, Cleveland, OH, USA.

Intravascular ultrasound (IVUS) has been used extensively in coronary applications. Its use in venous applications has increased as endovascular therapy has increasingly become the mainstay therapy for central venous diseases. IVUS has been used for both diagnostic and therapeutic purposes in managing venous stenotic disease, venous occlusive disease, and IVC filter placement and removal. IVUS has been proven to be effective in providing detailed measurement of the venous anatomy, which aid in determining the appropriate size and the approach for venous stent placement. In IVC filter placement, IVUS can provide detailed measurement and guide IVC filter placement in emergent and critical care settings. It also has certain utility in filter removal. At any rate, to date there are only a few studies examining its impact on patient outcomes. Prospective randomized controlled trials are warranted in the future.
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http://dx.doi.org/10.1024/0301-1526/a000914DOI Listing
January 2021

Poleward expansion of common snook Centropomus undecimalis in the northeastern Gulf of Mexico and future research needs.

PLoS One 2020 22;15(6):e0234083. Epub 2020 Jun 22.

Fisheries and Aquatic Sciences Program, Institute of Food and Agricultural Sciences, Nature Coast Biological Station, University of Florida, Cedar Key, Florida, United States of America.

Globally, rising temperatures have resulted in numerous examples of poleward shifts in species distribution patterns with accompanying changes in community structure and ecosystem processes. In the Gulf of Mexico, higher mean temperatures and less frequent winter freezes have led to the expansion of tropics-associated marine organisms. Our objectives were to quantify changing environmental conditions and the poleward expansion of the common snook Centropomus undecimalis into the Cedar Keys area of Florida, USA (29 deg N). The snook is an economically and recreationally important sport fish found from southern Brazil to south Florida. Cedar Key and the Lower Suwannee River are north of the snook's historically documented range, likely due to lethal water temperatures during winter. Using data from a long-term monitoring program, we report an increase in catches of snook in this area since 2007. The spatial and temporal expansion of the species began with adult fish in 2007. By 2018, snook of all sizes were found in the region, and we found strong evidence of local reproduction during 2016-2018. The locations of nursery habitat and winter thermal refuges (e.g., freshwater springs) need to be identified and have implications for land-use policy and minimum-flow regulations for rivers. The arrival of the snook in the northern Gulf of Mexico could affect food web ecology and habitat interactions among estuarine predators, and future studies should evaluate snook's food habits and competitive interactions with resident fishes in this expanded range. Our study provides an example of how species range expansions due to changing temperatures should result in new research priorities to evaluate impacts of climate change on coastal systems.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0234083PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7307751PMC
August 2020

Disturbance-driven changes to northern Gulf of Mexico nekton communities following the Deepwater Horizon oil spill.

Mar Pollut Bull 2020 Jun 11;155:111098. Epub 2020 May 11.

Dauphin Island Sea Lab, 101 Bienville Boulevard, Dauphin Island, AL 36528, United States of America.

The 2010 Deepwater Horizon (DwH) oil spill in the Gulf of Mexico discharged ~3.19 million barrels of oil into Gulf waters, making it one of the largest marine disasters in history in terms of volume. We report on the results of a study to assess oil impacts to coastal fishes and invertebrates. Using two-decades of fisheries-independent data in coastal Alabama and Mississippi, we document variability following both natural and anthropogenic disturbances from two periods pre-DwH (1997-2001 and 2007-2009), one intra-spill period for acute DwH effects (2010-2012) and one period post-spill for chronic, longer-term impacts (2014-2017). Results indicated significant changes to community structure, relative abundance, and diversity in the intra-spill period. Causation for changes is confounded by variables such as behavioral emigration, altered freshwater inflow, death of consumers, and the mandated fishery closure. Results highlight the need for long-term, comprehensive monitoring/observing systems to provide adequate background for assessing future disturbances.
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http://dx.doi.org/10.1016/j.marpolbul.2020.111098DOI Listing
June 2020

Assessing the Status of Mentorship Programs in Interventional Radiology Residency Training: Results of a 2018 Survey.

Curr Probl Diagn Radiol 2020 May - Jun;49(3):154-156. Epub 2020 Apr 3.

Department of Radiology, Cleveland Clinic, Cleveland, OH.

Rationale And Objectives: To assess the prevalence and structure of mentorship programs in interventional radiology (IR) residency programs.

Materials And Methods: A 12-question anonymous survey was distributed via email to all 78 program directors (PDs) of United States IR residency programs. The survey included information about the presence or absence of a formal mentorship program at their institution, how the program functions, potential barriers to implementation, and future plans for mentorship.

Results: Twenty-three of 78 integrated IR residency PDs completed the survey (response rate 29.5%). Thirteen of 23 reports that they currently have a formal mentorship program in place and 11 of 13 report no direct departmental support for mentorship. Of those that do not have a mentorship program in place, 5 of 10 report that implementation is underway. These programs report that the absence of a mentorship program is due to a lack of dedicated time and financial support. While 8 of 23 PDs were unaware of the Society of Interventional Radiology Mentor Match program, 6of 23 were registered as mentors through it. Nearly all PDs reported interest in receiving mentoring resources from SIR with the most popular choices being a dedicated mentorship educational course at the SIR annual meeting and regular mentorship articles and practical tips in publications such as IR quarterly.

Conclusions: Despite involvement of many IR PDs in mentorship, numerous residency programs lack a formal mentorship program. Of those with a program, most don't receive direct departmental support and those without a program cite lack of time and financial support as barriers to effective implementation.
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http://dx.doi.org/10.1067/j.cpradiol.2020.03.002DOI Listing
February 2021

Chemical Sensing and Chemoresponsive Pumping with Conical-Pore Polymeric Membranes.

Nanomaterials (Basel) 2020 Mar 21;10(3). Epub 2020 Mar 21.

Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.

Synthetic membranes containing asymmetrically shaped pores have been shown to rectify the ionic current flowing through the membrane. Ion-current rectification means that such membranes produce nonlinear current-voltage curves analogous to those observed with solid-state diode rectifiers. In order to observe this ion-current rectification phenomenon, the asymmetrically shaped pores must have pore-wall surface charge. Pore-wall surface charge also allows for electroosmotic flow (EOF) to occur through the membrane. We have shown that, because ion-current is rectified, EOF is likewise rectified in such membranes. This means that flow through the membrane depends on the polarity of the voltage applied across the membrane, one polarity producing a higher, and the opposite producing a lower, flow rate. As is reviewed here, these ion-current and EOF rectification phenomena are being used to develop new sensing technologies. Results obtained from an ion-current-based sensor for hydrophobic cations are reviewed. In addition, ion-current and EOF rectification can be combined to make a new type of device-a chemoresponsive nanofluidic pump. This is a pump that either turns flow on or turns flow off, when a specific chemical species is detected. Results from a prototype Pb chemoresponsive pump are also reviewed here.
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http://dx.doi.org/10.3390/nano10030571DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7153383PMC
March 2020

Augmented and Mixed Reality: Technologies for Enhancing the Future of IR.

J Vasc Interv Radiol 2020 Jul 13;31(7):1074-1082. Epub 2020 Feb 13.

Department of Interventional Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104.

Augmented and mixed reality are emerging interactive and display technologies. These technologies are able to merge virtual objects, in either 2 or 3 dimensions, with the real world. Image guidance is the cornerstone of interventional radiology. With augmented or mixed reality, medical imaging can be more readily accessible or displayed in actual 3-dimensional space during procedures to enhance guidance, at times when this information is most needed. In this review, the current state of these technologies is addressed followed by a fundamental overview of their inner workings and challenges with 3-dimensional visualization. Finally, current and potential future applications in interventional radiology are highlighted.
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http://dx.doi.org/10.1016/j.jvir.2019.09.020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7311237PMC
July 2020

3D Holographic Guidance and Navigation for Percutaneous Ablation of Solid Tumor.

J Vasc Interv Radiol 2020 03 31;31(3):526-528. Epub 2020 Jan 31.

Department of Biomedical Engineering, Imaging Institute, Cleveland Clinic, Cleveland, Ohio; Department of Radiology, Imaging Institute, Cleveland Clinic, 2625 Butternut Lane, Pepper Pike, Cleveland, OH 44124.

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http://dx.doi.org/10.1016/j.jvir.2019.09.027DOI Listing
March 2020

Plant diversity effect on water quality in wetlands: a meta-analysis based on experimental systems.

Ecol Appl 2020 06 20;30(4):e02074. Epub 2020 Feb 20.

Chaire de Recherche du Canada en Intégrité Écologique, Groupe de Recherche Interuniversitaire en Limnologie, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, Quebec, G9A 5H7, Canada.

The ecological literature reports little empirical evidence from biodiversity-ecosystem functioning (BEF) experiments in wetland systems, even though wetlands are widely known for their water filtering capacity. Experiments comparing the effect of plant monocultures and mixtures on water quality to improve pollutant removal efficiency in treatment wetlands share the characteristics of classical BEF experiments, and so could provide insights for wetland management. To add to our understanding of BEF relationships in wetlands, we evaluated plant diversity effects on water purification through a meta-analysis of freshwater experimental wetlands comparing monocultures to mixtures. We found 28 studies that matched our criteria for BEF analysis, for a total of 561 diversity effects on pollutant removal. Overall, the meta-analysis shows no significant effect of plant richness on removal of total suspended solids, but a positive effect on chemical oxygen demand and total nitrogen removal, and a marginal effect on phosphorus removal. Thus, the results of this meta-analysis are consistent with reports of an overall positive biodiversity effect on ecosystem properties. An analysis of moderator variables shows that the experimental context (size of the experimental units, nutrient load, duration of the experiment) does not explain much of the residual variance. For pollutants that benefit from a positive plant richness effects on removal, mixtures do not perform better than the best monoculture. We found no evidence that plant richness effects are due to functional complementarity among species rather than to the presence of particularly efficient species. Complementarity effects may be less prevalent in highly productive, nutrient-rich wetlands, compared to nutrient-limited environments such as natural grasslands. Although findings must be confirmed by long-term field experiments under natural conditions, result from experimental wetland systems may contribute to a better understanding of biodiversity effect on ecosystem functions in wetlands, in addition to guide practices in natural wetland restoration and the use of constructed wetlands for water treatment.
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http://dx.doi.org/10.1002/eap.2074DOI Listing
June 2020

Gastrointestinal Malignancies and Venous Thromboembolic Disease: Clinical Significance and Endovascular Interventions.

Dig Dis Interv 2020 22;4(3):260-266. Epub 2020 Sep 22.

Section of Interventional Radiology, Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri.

Gastrointestinal malignancy encompasses a wide range of disease processes. Its incidence and mortality rate rank among the highest of all cancers. Venous thromboembolic disease is a common complication of gastrointestinal malignancy. Anticoagulation remains the first-line therapy. However, for patients who cannot tolerate or have failed anticoagulation, inferior vena cava (IVC) filter placement may be an option. Furthermore, to improve symptom resolution and reduce the severity of postthrombotic syndrome, catheter-directed thrombolysis (CDT) may be an option. Recent randomized trials including the ATTRACT (Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis) trial have shed new light on the efficacy and safety of CDT and related methods. Overall, the decision to proceed with IVC filter placement or CDT must be individualized.
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http://dx.doi.org/10.1055/s-0040-1716739DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8294347PMC
September 2020

Retrospective comparative analysis of intraocular lens calculation formulas after hyperopic refractive surgery.

PLoS One 2019 7;14(11):e0224981. Epub 2019 Nov 7.

Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, United States of America.

Purpose: To compare the intraocular lens calculation formulas and evaluate postoperative refractive results of patients with previous hyperopic corneal refractive surgery.

Design: Retrospective, comparative, observational study.

Setting: Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA.

Methods: Clinical charts and optical biometric data of 39 eyes from 24 consecutive patients diagnosed with previous hyperopic laser vision correction and cataract surgery were reviewed and analyzed. The Intraocular lens (IOL) power calculation using the Holladay 2 formula (Lenstar) and the American Society of Cataract and Refractive Surgery (ASCRS) Post-Refractive IOL Calculator (version 4.9, 2017) were compared to the actual manifest refractive spherical equivalent (MRSE) following cataract surgery. No pre-Lasik / PRK or post-Lasik / PRK information was used in any of the calculations. The IOL prediction error, the mean IOL prediction error, the median absolute refractive prediction error, and the percentages of eyes within ±0.50 diopter (D) and ±1.00 D of the predicted refraction were calculated.

Results: The Holladay 2 formula produced a mean arithmetic IOL prediction error significantly different from zero (P = 0.003). Surprisingly, the mean arithmetic IOL prediction errors generated by Shammas, Haigis-L and Barret True K No History formulas were not significantly different from zero (P = 0.14, P = 0.49, P = 0.81, respectively).There were no significant differences in the median absolute refractive prediction error or percentage of eyes within ± 0.50 D or ± 1.00 D of the predicted refraction between formulas or methods.

Conclusion: In eyes with previous hyperopic LASIK/PRK and no prior data, there were no significant differences in the accuracy of IOL power calculation between the Holladay 2 formula and the ASCRS Post-refractive IOL calculator.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0224981PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6837514PMC
March 2020

Low-Voltage Flow-Through Electroporation Membrane and Method.

Methods Mol Biol 2020 ;2050:43-55

Department of Chemistry, University of Florida, Gainesville, FL, USA.

Electroporation uses high electric field gradients to create pores within the membrane of living cells in order to deliver a substance, for example a gene, into the cytoplasm. To achieve such gradients, current electroporation devices deliver voltage pulses in the kV range to the cell medium. We describe here a new device based on gold-microtube membranes that can accomplish electroporation with voltage pulses that are orders of magnitude smaller, 4 V. The percentages of electroporated bacteria were found to be more than an order of magnitude higher than obtained with a commercial electroporator.
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http://dx.doi.org/10.1007/978-1-4939-9740-4_5DOI Listing
October 2020

Brief review: Pulmonary artery aneurysms and pseudoaneurysms.

Int J Cardiovasc Imaging 2019 Jul 13;35(7):1357-1364. Epub 2019 Jun 13.

Section of Interventional Radiology, Department of Radiology, Cleveland Clinic Foundation, Cleveland, USA.

The purpose of this review article is to provide a brief overview of pulmonary artery aneurysms and pseudoaneurysms, to discuss the classifications of these conditions, review the role of imaging and discuss management in affected patients.
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http://dx.doi.org/10.1007/s10554-019-01547-3DOI Listing
July 2019

TRActional DIabetic reTInal detachment surgery with co-adjuvant intravitreal dexamethasONe implant: the TRADITION STUDY.

Acta Diabetol 2019 Oct 14;56(10):1141-1147. Epub 2019 May 14.

Division of Ophthalmology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.

Aim: Main failure of diabetic tractional retinal detachment (TRD) surgery is the development of proliferative vitreoretinopathy (PVR), causing higher re-detachment rates. We investigated whether the use of dexamethasone (DEX) implant at the end of pars plana vitrectomy (PPV) with silicone oil tamponade might have an impact on these outcomes.

Design: Comparative, nonrandomized, retrospective study.

Participants: A total of 148 eyes from 148 patients that underwent PPV with silicone oil tamponade for diabetic TRD (with DEX implant, n = 52; without DEX implant, n = 96).

Methods: Consecutive patients' records were reviewed for time between TRD diagnosis and surgery; lens status before surgery and after 6, 12, and 24 months; retina attachment rate after primary PPV; change in postoperative PVR severity; rate of re-detachment at 6, 12, and 24 months; use of IOP lowering treatment after 6, 12, and 24 months; surgery details; intra- and postoperative complications. Correlations between outcome measures, postoperative PVR severity, and re-detachment rates were analyzed.

Main Outcome Measures: Change in postoperative PVR severity and retinal re-detachment rates with and without the adjuvant use of DEX implant.

Results: Retinal re-detachment rates were significantly higher in the group of patients that did not receive DEX implant [11/96 (11.5%) vs. 0/52 (0%), p = 0.049; 11/84 (12.9%) vs. 4/52 (7.7%), p = 0.007; 14/71 (19.7%) vs. 5/52 (10%) p < 0.001 at 6, 12, and 24 months, respectively]. PVR severity correlated with retinal status at 12 and 24 months (p = 0.018 and p = 0.027, respectively). The difference in PVR severity between the two groups was statistically significant at 6, 12, and 24 months (p < 0.001).

Conclusions: DEX implant at the end of PPV in patients with diabetic TRD improves PVR severity and decreases re-detachment rates. This should be considered as an option in the customized treatment of TRD.
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http://dx.doi.org/10.1007/s00592-019-01357-yDOI Listing
October 2019

Herbivory of oil-exposed submerged aquatic vegetation Ruppia maritima.

PLoS One 2018 5;13(12):e0208463. Epub 2018 Dec 5.

Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America.

Oil spills, such as the Deepwater Horizon spill in the Gulf of Mexico, have the potential to dramatically alter coastal food webs through a variety of mechanisms. While oil can have direct impacts on primary producers through toxicity and shading, it is also possible that more subtle, indirect changes to the interactions among organisms could alter energy flow through the ecosystem. Here, we present the results of a series of manipulative experiments to determine the impacts of oil exposure on herbivory of Ruppia maritima, one of the most common species of submerged vegetation found in the region impacted by the 2010 Deepwater Horizon oil spill. In previous experiments, R. maritima was grown in a range of manipulated sediment oil concentrations. Using plant tissue from this experiment, we analyzed the effects of oil on plant chemical composition and found that plant carbon:nitrogen ratio (C:N) was reduced by as much as 21% in plants exposed to higher concentrations of oil. Given that nitrogen plays a key role in herbivore preference patterns, we performed herbivory assays and found oil-contaminated plants were preferred by herbivores in choice trials, although subsequent no-choice experiments indicated herbivores consumed less oil-contaminated tissue. We hypothesize the reason for this is that more tissue of higher C:N content is needed to meet similar metabolic demands while avoiding the potentially negative impacts of feeding on contaminated tissues. These results indicate that substantial food web alterations may occur via enhanced consumption of oil-exposed plants and provides vital information necessary to assess the large-scale impact of oil on submerged macrophytes.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0208463PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6281300PMC
May 2019

An inquiry-based exercise in medicinal chemistry: Synthesis of a molecular library and screening for potential antimalarial and anti-inflammatory compounds.

Biochem Mol Biol Educ 2018 09;46(5):424-434

Chemistry Department, Lawrence University, Appleton, Wisconsin, 54911.

The development of new medicines holds particular fascination for chemistry, biochemistry, and biology students interested in a career in medicine or the life sciences. The identification and refinement of lead compounds to treat diseases requires researchers to be facile in a number of different disciplines including organic synthesis, biochemistry, cell biology, and molecular biology. We have developed an interdisciplinary, inquiry-based laboratory spanning both organic chemistry and biochemistry classes that acquaints students with research in medicinal chemistry. The first part of the exercise takes place in the second semester of organic chemistry, where pairs of students design and execute their own multistep synthesis of a novel compound with anti-inflammatory and/or antimalarial potential. Later, in first semester biochemistry, many of the same students then test these synthesized compounds for cytotoxicity, inhibition of the enzyme nitric oxide synthase, and inhibition of the transcription factor NF-kB. Learning outcomes, measured by the Classroom Undergraduate Research Experience (CURE) survey, suggest that students participating in both classes had higher gains than an average student. © 2018 International Union of Biochemistry and Molecular Biology, 46(5):424-434, 2018.
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http://dx.doi.org/10.1002/bmb.21138DOI Listing
September 2018

Contraceptive Implant Removals with the Use of IR.

J Vasc Interv Radiol 2018 09;29(9):1317-1319

Division of Interventional Radiology, University of Colorado, 12401 E 17th Avenue, Mailstop L954, Aurora, Colorado 80045.

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http://dx.doi.org/10.1016/j.jvir.2018.02.014DOI Listing
September 2018

Patient Radiation Dose Reduction Considerations in a Contemporary Interventional Radiology Suite.

Cardiovasc Intervent Radiol 2018 Dec 21;41(12):1925-1934. Epub 2018 Aug 21.

Diagnostic Radiology, Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.

Purpose: We sought to evaluate patient radiation exposure during complex liver interventional procedures performed with newer angiography equipment.

Materials And Methods: We conducted a retrospective study of transjugular intrahepatic portosystemic shunt (TIPS) creations and liver tumor embolizations performed in our new angiography suite (Discovery IGS740, GE Healthcare). T tests were used to compare air kerma-area product (P) and reference plane air kerma (K) in the new room versus data from historical rooms and previous studies (including the RAD IR study). Results were expressed as medians [interquartile ranges (Q1, Q3)].

Results: From February 2015 to June 2016, 134 complex liver interventional procedures were performed in the new room, including 14 TIPS creations, 60 hepatic tumor arterial embolizations (HAEs), 26 Y90 mappings (Y90m), and 34 Y90 radioembolizations (Y90). K (Gy) values were as follows: TIPS, 0.65 (0.24, 1.15); HAE, 0.89 (0.49, 1.49); Y90m, 0.54 (0.38, 0.94); Y90, 0.46 (0.21, 1.06). P (Gy·cm) values were as follows: TIPS, 148.2 (66.7, 326.5); HAE, 142.6 (88, 217.8); Y90m, 148.3 (98.2, 247); Y90, 90.8 (43.9, 161.5). K and P were lower in the new room than in historical rooms [K and P reductions: TIPS, 58 and 49%; HAE, 31 and 39%; Y90m, 58 and 52%; Y90, 49 and 56% (p < 0.05)] and versus the RAD IR study [K and P reductions: TIPS, 64 and 43%; HAE, 26 and 40% (p < 0.05)].

Conclusions: Using the latest technology and image processing tools enables significant reduction in radiation exposure during complex liver interventional procedures.
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http://dx.doi.org/10.1007/s00270-018-2052-7DOI Listing
December 2018

Chemoresponsive Nanofluidic Pump That Turns Off in the Presence of Lead Ion.

Anal Chem 2018 06 8;90(12):7715-7720. Epub 2018 Jun 8.

Department of Chemistry , University of Florida , Gainesville , Florida 32611-7200 , United States.

There are many applications that require the integration of a pump and a chemical sensor so that the solution being pumped can be analyzed in real time for a specific chemical species and the flow adjusted according to the measured concentration of that species. We describe here an alternative strategy: a chemoresponsive pump where a single device acts as both the sensor and pump simultaneously. We demonstrate this concept with a nanofluidic Pb-responsive pump that uses electroosmotic flow as the pumping technology, and a Pb-binding ionophore that allows the device to selectively respond to Pb. The pump yields high flow rates at low Pb concentrations (<1 μM), but flow rate decreases with concentrations above this threshold and ultimately goes to zero at concentrations above 100 μM.
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http://dx.doi.org/10.1021/acs.analchem.8b01623DOI Listing
June 2018

Contraceptive Implant Migration and Removal by Interventional Radiology.

Semin Intervent Radiol 2018 Mar 5;35(1):23-28. Epub 2018 Apr 5.

Department of Interventional Radiology, University of Colorado, Denver, Colorado.

As the reversible contraceptive arm implants grow more popular, there is an increasing need to recognize the complications resulting from implant migration and removal. This review summarizes the findings of imaging and removal methods. When an implant is lost, the axillary region should be investigated first. If the implant still cannot be found, visualization though different methods have been employed for non-radiopaque implants. Real-time fluoroscopic-guided localization and removal can be accomplished for radiopaque Nexplanon. Once the implant has been located, standard removal method and other modified techniques can be used to safely remove the implant depending on the implant's location.
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http://dx.doi.org/10.1055/s-0038-1636517DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5886766PMC
March 2018

Nanomaterial Preparation by Extrusion through Nanoporous Membranes.

Small 2018 05 22;14(18):e1703493. Epub 2018 Feb 22.

Vascular Biology Program, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.

Template synthesis represents an important class of nanofabrication methods. Herein, recent advances in nanomaterial preparation by extrusion through nanoporous membranes that preserve the template membrane without sacrificing it, which is termed as "non-sacrificing template synthesis," are reviewed. First, the types of nanoporous membranes used in nanoporous membrane extrusion applications are introduced. Next, four common nanoporous membrane extrusion strategies: vesicle extrusion, membrane emulsification, precipitation extrusion, and biological membrane extrusion, are examined. These methods have been utilized to prepare a wide range of nanomaterials, including liposomes, emulsions, nanoparticles, nanofibers, and nanotubes. The principle and historical context of each specific technology are discussed, presenting prominent examples and evaluating their positive and negative features. Finally, the current challenges and future opportunities of nanoporous membrane extrusion methods are discussed.
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http://dx.doi.org/10.1002/smll.201703493DOI Listing
May 2018

Radiation Exposure in the Medical ICU: Predictors and Characteristics.

Chest 2018 05 31;153(5):1160-1168. Epub 2018 Jan 31.

Cleveland Clinic Abu Dhabi, Al Maryah Island, Abu Dhabi, United Arab Emirates.

Background: Patients admitted to the medical ICU (MICU) are often subjected to multiple radiologic studies. We hypothesized that some endure radiation dose exposure (cumulative effective dose [CED]) in excess of annual US federal occupational health standard limits (CED ≥ 50 mSv) and 5-year cumulative limit (CED ≥ 100 mSv). We also evaluated the correlation of CED with Acute Physiology and Chronic Health Evaluation (APACHE) III score and other clinical variables.

Methods: Retrospective observational study conducted in an academic medical center involving all adult admissions (N = 4,155) to the MICU between January 2013 and December 2013. Radiation doses from ionizing radiologic studies were calculated from reference values to determine the CED.

Results: Three percent of admissions (n = 131) accrued CED ≥ 50 mSv (1% [n = 47] accrued CED ≥ 100 mSv). The median CED was 0.72 mSv (interquartile range, 0.02-5.23 mSv), with a range of 0.00 to 323 mSv. Higher APACHE III scores (P = .003), longer length of MICU stay (P < .0001), sepsis (P = .03), and gastrointestinal disorders and bleeding (P < .0001) predicted higher CED in a multivariable linear regression model. Patients with gastrointestinal bleeding and disorders had an odds ratio of 21.05 (95% CI, 13.54-32.72; P < .0001) and 6.94 (95% CI, 3.88-12.38; P < .0001), respectively, of accruing CED ≥ 50 mSv in a multivariable logistic regression model. CT scan and interventional radiology accounted for 49% and 38% of the total CED, respectively.

Conclusions: Patients in the MICU are exposed to radiation doses that can be substantial, exceeding federal annual occupational limits, and in a select subset, are > 100 mSv. Efforts to justify, restrict, and optimize the use of radiologic resources when feasible are warranted.
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http://dx.doi.org/10.1016/j.chest.2018.01.019DOI Listing
May 2018

The Effect of Voltage Charging on the Transport Properties of Gold Nanotube Membranes.

Small 2018 05 26;14(18):e1703290. Epub 2018 Jan 26.

Department of Chemistry, University of Florida, Gainesville, FL, 32611, USA.

Porous membranes are used in chemical separations and in many electrochemical processes and devices. Research on the transport properties of a unique class of porous membranes that contain monodisperse gold nanotubes traversing the entire membrane thickness is reviewed here. These gold nanotubes can act as conduits for ionic and molecular transports through the membrane. Because the tubes are electronically conductive, they can be electrochemically charged by applying a voltage to the membrane. How this "voltage charging" affects the transport properties of gold nanotube membranes is the subject of this Review. Experiments showing that voltage charging can be used to reversibly switch the membrane between ideally cation- and anion-transporting states are reviewed. Voltage charging can also be used to enhance the ionic conductivity of gold nanotube membranes. Finally, voltage charging to accomplish electroporation of living bacteria as they pass through gold nanotube membranes is reviewed.
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http://dx.doi.org/10.1002/smll.201703290DOI Listing
May 2018
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