316 research outputs found
Cardiac Implantable Electronic Device Reutilization: Battery Life of Explanted Devices at a Tertiary Care Center
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106926/1/pace12321.pd
Review of Rare Earth Elements as Fertilizers and Feed Additives: A Knowledge Gap Analysis
Rare earth elements (REEs) are key constituents of modern technology and play important roles in various chemical and industrial applications. They also are increasingly used in agricultural and zootechnical applications, such as fertilizers and feed additives. Early applications of REEs in agriculture have originated in China over the past several decades with the objective of increasing crop productivity and improving livestock yield (e.g., egg production or piglet growth). Outside China, REE agricultural or zootechnical uses are not currently practiced. A number of peer-reviewed manuscripts have evaluated the adverse and the positive effects of some light REEs (lanthanum and cerium salts) or REE mixtures both in plant growth and in livestock yield. This information was never systematically evaluated from the growing body of scientific literature. The present review was designed to evaluate the available evidence for adverse and/or positive effects of REE exposures in plant and animal biota and the cellular/molecular evidence for the REE-associated effects. The overall information points to shifts from toxic to favorable effects in plant systems at lower REE concentrations (possibly suggesting hormesis). The available evidence for REE use as feed additives may suggest positive outcomes at certain doses but requires further investigations before extending this use for zootechnical purposes
Effect of Catheter Ablation on Progression of Paroxysmal Atrial Fibrillation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90181/1/j.1540-8167.2011.02137.x.pd
Comparative toxicities of selected rare earth elements: Sea urchin embryogenesis and fertilization damage with redox and cytogenetic effects
Background: Broad-rangingadverseeffectsareknownforrareearthelements(REE),yetonlyafew
studies testedthetoxicityofseveralREE,promptingstudiesfocusingonmulti-parameterREEtoxicity.
Methods: TrichloridesaltsofY,La,Ce,Nd,Sm,EuandGdweretestedin Paracentrotuslividus sea urchin
embryos andspermfor:(1)developmentaldefectsineitherREE-exposedlarvaeorintheoffspringof
REE-exposedsperm;(2)fertilizationsuccess;(3)mitoticanomaliesinREE-exposedembryosandinthe
offspring ofREE-exposedsperm,and(4)reactiveoxygenspecies(ROS)formation,andmalondialdehyde
(MDA)andnitricoxide(NO)levels.
Results: REEs affected P.lividus larvaewithconcentration-relatedincreaseindevelopmentaldefects,
106 to 104 M, rankingas:Gd(III)4Y(III)4La(III)4Nd(III)â
Eu(III)4Ce(III)â
Sm(III). Nominalcon-
centrations ofREEsaltswereconfirmed byinductivelycoupledplasmamassspectrometry(ICP-MS).
Significant increasesinMDAlevels,ROSformation,andNOlevelswerefoundinREE-exposedembryos.
Sperm exposuretoREEs(105 to 104 M) resultedinconcentration-relateddecreaseinfertilization
success alongwithincreaseinoffspringdamage.Decreasedmitoticactivityandincreasedaberration
ratesweredetectedinREE-exposedembryosandintheoffspringofREE-exposedsperm.
Conclusion: REE-associated toxicityaffectingembryogenesis,fertilization,cytogeneticandredoxend-
points showeddifferentactivitiesoftestedREEs.Damagetoearlylifestages,alongwithredoxandcy-
togeneticanomaliesshouldbethefocusoffutureREEtoxicitystudies
Utility of Atrial and Ventricular Cycle Length Variability in Determining the Mechanism of Paroxysmal Supraventricular Tachycardia
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72411/1/j.1540-8167.2007.00860.x.pd
Resolving the effects of environmental micro- and nanoplastics exposure in biota: A knowledge gap analysis
The pervasive spread of microplastics (MPs) and nanoplastics (NPs) has raised significant concerns on their toxicity in both aquatic and terrestrial environments. These polymer-based materials have implications for plants, wildlife and human health, threatening food chain integrity and ultimate ecosystem resilience. An extensive â and growing â body of literature is available on MP- and NP-associated effects, including in a number of aquatic biota, with as yet limited reports in terrestrial environments. Effects range from no detectable, or very low level, biological effects to more severe outcomes such as (but not limited to) increased mortality rates, altered immune and inflammatory responses, oxidative stress, genetic damage and dysmetabolic changes. A well-established exposure route to MPs and NPs involves ingestion with subsequent incorporation into tissues. MP and NP exposures have also been found to lead to genetic damage, including effects related to mitotic anomalies, or to transmissible damage from sperm cells to their offspring, especially in echinoderms. Effects on the proteome, transcriptome and metabolome warrant ad hoc investigations as these integrated âomicsâ workflows could provide greater insight into molecular pathways of effect. Given their different physical structures, chemical identity and presumably different modes of action, exposure to different types of MPs and NPs may result in different biological effects in biota, thus comparative investigations of different MPs and NPs are required to ascertain the respective effects. Furthermore, research on MP and NP should also consider their ability to act as vectors for other toxicants, and possible outcomes of exposure may even include effects at the community level, thus requiring investigations in mesocosm models
Randomized Comparison of Cavotricuspid Isthmus Ablation for Atrial Flutter Using an Open IrrigationâTip versus a LargeâTip Radiofrequency Ablation Catheter
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86825/1/j.1540-8167.2011.02045.x.pd
Mapping and Ablation of Frequent Post-Infarction Premature Ventricular Complexes
Mapping of Post-Infarction PVCs .â Introduction: Premature ventricular complexes (PVCs) occur frequently in patients with heart disease. The sites of origin of PVCs in patients with prior myocardial infarction and the response to catheter ablation have not been systematically assessed. Methods and Results: In 28 consecutive patients (24 men, age 60 ± 10, ejection fraction [EF] 0.37 ± 0.14) with remote myocardial infarction referred for catheter ablation of symptomatic refractory PVCs, the PVCs were mapped by activation mapping or pace mapping using an irrigated-tip catheter in conjunction with an electroanatomic mapping system. The site of origin (SOO) was classified as being within low-voltage (scar) tissue (amplitude â€1.5 mV) or tissue with preserved voltage (>1.5 mV). The SOO was confined to endocardial scar tissue in 24/28 patients (86%). The SOO was outside of scar in 3 patients and could not be identified in 1 patient. At the SOO, local endocardial activation preceded the PVC by 46 ± 19 ms, and the electrogram amplitude during sinus rhythm was 0.48 ± 0.34 mV. The PVCs were effectively ablated in 25/28 patients (89%), resulting in a decrease in PVC burden on a 24-hour Holter monitor from 15.6 ± 12.3% to 2.4 ± 4.2% (P < 0.001). The SOO most often was confined to scar tissue located in the left ventricular septum and the papillary muscles. Conclusion: Similar to post-infarction ventricular tachycardia, PVCs after remote myocardial infarction most often originate within scar tissue. Catheter ablation of these PVCs has a high-success rate. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1002-1008, September 2010)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79266/1/j.1540-8167.2010.01771.x.pd
Timeâ and FrequencyâDomain Characteristics of Atrial Electrograms During Sinus Rhythm and Atrial Fibrillation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87064/1/j.1540-8167.2011.02022.x.pd
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