Damsgaardmccaffrey5173
The extents of these key detoxification processes were strongly dependent on the species-specific detoxification strategies and levels of dietary MeHg exposure. We also found higher mass-independent fractionation (MIF, Δ199Hg) values in feathers relative to internal tissues, possibly due to different integration times of Hg exposure between permanently active organs and inert tissues as feathers. Hg isotope variations reported in this study show evidence of detoxification processes in seabirds and propose a powerful approach for deep investigation of the Hg metabolic processes in seabirds.Influences of colloidal stabilities of nanoparticles (NPs) on the bioaccumulation of co-existing pollutants remains largely unknown. In this study, two oxidation products of nanoscale zero-valent iron (nZVI) with totally varied colloidal stabilities, termed highly oxidized nZVI (HO-nZVI) and lowly oxidized nZVI (LO-nZVI), were exposed to zebrafish with chromium (Cr); this approach was used to investigate the impacts of colloidal stability of oxidized nZVI on the bioaccumulation of Cr in zebrafish. A significant increase in the Cr and NP content in the viscera of fish in the presence of the oxidized nZVI after 20 days of exposure was confirmed, which indicated that Cr was consumed by fish through the uptake of the NPs. Furthermore, a significantly higher level of the HO-nZVI accumulated in the viscera in contrast to LO-nZVI, which suggested that the colloidal stability of NP is a crucial factor when evaluating the accessibility of NPs to zebrafish. Thus, HO-nZVI induced a significantly stronger enhancement of Cr content in fish than LO-nZVI. Our results suggest that oxidized nZVI will act as the carrier of co-existing heavy metals and change the transportation and distribution of heavy metals in zebrafish; moreover, the colloidal stability of NP will have a significant influence on the bioaccumulation of coexisting Cr.Invasive, nuisance aquatic species such as Eurasian watermilfoil (Myriophyllum spicatum) are rapidly spreading across the United States. One common active ingredient used to control this invasive species is 2,4-Dichlorophenoxyacetic acid (2,4-D). Application of 2,4-D to aquatic environments typically occurs while many freshwater fish are spawning and due to 2,4-D stability in aquatic environments, many non-target species experience prolonged exposure throughout embryogenesis and larval development. The impacts of 2,4-D exposure on phylogenetically distant fish species is poorly understood. Herein, we investigated the impacts of the 2,4-D commercial herbicide DMA4®IVM on nine freshwater fish species from six different families (four orders) at different points during ontogeny. Each species was exposed to ecologically relevant concentrations of a commercial 2,4-D herbicide (0.05, 0.50, and 2.00 ppm or mg/L 2,4-D a. e.), and effects on morphology, survival, and growth were evaluated. Our results demonstrate that exposure of embryonic and larval fish to ecologically relevant concentrations of a commercial 2,4-D herbicide reduced survival in early developmental stages of six freshwater species that spanned five phylogenetic families and three phylogenetic orders; however, sensitivity to 2,4-D exposure did not show correlation with phylogenetic proximity. selleck kinase inhibitor Altogether, our results indicate that the use of 2,4-D herbicides in aquatic ecosystems at current recommended concentrations (≤2 ppm whole-lake treatment) could present risk to multiple freshwater fish species survival during early development.Advances in synthetic biology and microbiology have enabled the creation of engineered bacteria which can sense and report on intracellular and extracellular signals. When deployed in vivo these whole-cell bacterial biosensors can act as sentinels to monitor biomolecules of interest in human health and disease settings. This is particularly interesting in the context of the gut microbiota, which interacts extensively with the human host throughout time and transit of the gut and can be accessed from feces without requiring invasive collection. Leveraging rational engineering approaches for genetic circuits as well as an expanding catalog of disease-associated biomarkers, bacterial biosensors can act as non-invasive and easy-to-monitor reporters of the gut. Here, we summarize recent engineering approaches applied in vivo in animal models and then highlight promising technologies for designing the next generation of bacterial biosensors.
Data regarding outcomes for patients with severe aortic stenosis (AS) with concomitant aortic insufficiency (AI), undergoing transcatheter aortic valve replacement (TAVR) are limited. link2 This study aimed to analyze the prevalence of severe AS with concomitant AI among patients undergoing TAVR and outcomes of TAVR in this patient group.
Using data from the STS/ACC-TVT Registry, we identified patients with severe AS with or without concomitant AI who underwent TAVR between 2011 and 2016. Patients were categorized based on the severity of pre-procedural AI. Multivariable proportional hazards regression models were used to examine all-cause mortality and heart failure (HF) hospitalization at 1-year. Among 54,535 patients undergoing TAVR, 42,568 (78.1%) had severe AS with concomitant AI. Device success was lower in patients with severe AS with concomitant AI as compared with isolated AS. The presence of baseline AI was associated with lower 1 year mortality (HR 0.94 per 1 grade increase in AI severity; 95% CI, 0.th severe AS with concomitant AI as compared with isolated AS. The presence of baseline AI was associated with lower 1 year mortality (HR 0.94 per 1 grade increase in AI severity; 95% CI, 0.91-0.98, P less then .001) and HF hospitalization (HR 0.87 per 1 grade increase in AI severity; 95% CI, 0.84-0.91, P less then .001).
To learn if quantitative ultrasound (QUS) distinguishes the tongues of healthy participants and amyotrophic lateral sclerosis (ALS) patients by echo intensity (EI) and to evaluate if EI correlates with measures of bulbar function.
Ultrasound was performed along the midline of the anterior tongue surface in 16 ALS patients and 16 age-matched controls using a linear hockey stick 16-7MHz transducer. A region of interest was manually drawn and then EI was determined for the upper 1/3 of the muscle. For patients, the ALS functional rating scale - revised (ALSFRS-R) was used to calculate bulbar sub-scores and the Iowa Oral Performance Instrument (IOPI) was used to measure tongue strength.
EI was significantly higher in ALS patients than in healthy participants (49.8 versus 37.8 arbitrary units, p<0.01). In the patient group, EI was negatively correlated with ALSFRS-R bulbar sub-score (R
=-0.65, p<0.01). An inverse correlation between EI and tongue strength did not reach significance (R
=-0.34, p=0.28).
This study suggests that EI can differentiate healthy from diseased tongue muscle, and correlates with a standard functional measure in ALS patients.
Tongue EI may represent a novel biomarker for bulbar dysfunction in ALS.
Tongue EI may represent a novel biomarker for bulbar dysfunction in ALS.
The functional connectivity (FC) of major depression disorder (MDD) has not been well studied under naturalistic and continuous stimuli conditions. In this study, we investigated the frequency-specific FC of MDD patients exposed to conditions of music perception using ongoing electroencephalogram (EEG).
First, we applied the phase lag index (PLI) method to calculate the connectivity matrices and graph theory-based methods to measure the topology of brain networks across different frequency bands. Then, classification methods were adopted to identify the most discriminate frequency band for the diagnosis of MDD.
During music perception, MDD patients exhibited a decreased connectivity pattern in the delta band but an increased connectivity pattern in the beta band. Healthy people showed a left hemisphere-dominant phenomenon, but MDD patients did not show such a lateralized effect. Support vector machine (SVM) achieved the best classification performance in the beta frequency band with an accuracy of 89.7%, sensitivity of 89.4% and specificity of 89.9%.
MDD patients exhibited an altered FC in delta and beta bands, and the beta band showed a superiority in the diagnosis of MDD.
Our study provided a promising reference for the diagnosis of MDD, and revealed a new perspective for understanding the topology of MDD brain networks during music perception.
Our study provided a promising reference for the diagnosis of MDD, and revealed a new perspective for understanding the topology of MDD brain networks during music perception.
Sub-motor threshold 5Hz repetitive paired associative stimulation (5Hz-rPAS
) produces a long-lasting increase in corticospinal excitability. Assuming a spike-timing dependent plasticity-like (STDP-like) mechanism, we hypothesized that 5Hz-rPAS at a shorter inter-stimulus interval (ISI) of 15ms (5Hz-rPAS
) would exert a lasting inhibitory effect on corticospinal excitability.
20 healthy volunteers received two minutes of 5Hz-rPAS
. Transcranial magnetic stimulation (TMS) was applied over the motor hotspot of the right abductor pollicis brevis muscle at 90% active motor threshold. Sub-motor threshold peripheral electrical stimulation was given to the left median nerve 15ms before each TMS pulse. We assessed changes in mean amplitude of the unconditioned motor evoked potential (MEP), short-latency intracortical inhibition (SICI), intracortical facilitation (ICF), short-latency afferent inhibition (SAI), long-latency afferent inhibition (LAI), and cortical silent period (CSP) before and for 60 minutes after 5-Hz rPAS
.
Subthreshold 5-Hz rPAS
produced a 20-40% decrease in mean MEP amplitude along with an attenuation in SAI, lasting at least 60 minutes. A follow-up experiment revealed that MEP facilitation was spatially restricted to the target muscle.
Subthreshold 5-Hz rPAS
effectively suppresses corticospinal excitability. Together with the facilitatory effects of subthreshold 5-Hz rPAS
(Quartarone et al., J Physiol 2006;575657-670), the results show that sub-motor threshold 5-Hz rPAS induces STDP-like bidirectional plasticity in the motor cortex.
The results of the present study provide a new short-time paradigm of long term depression (LTD) induction in human sensory-motor cortex.
The results of the present study provide a new short-time paradigm of long term depression (LTD) induction in human sensory-motor cortex.
To explore neurophysiological features of musicogenic epilepsy (ME), discussing experimental findings in the framework of a systematic review on ME.
Two patients with ME underwent high-density-electroencephalography (hd-EEG) while listening to ictogenic songs. In one case, musicogenic seizures were elicited. Independent component analysis (ICA) was applied to hd-EEG, and components hosting interictal and ictal elements were identified and localized. link3 Finally, the temporal dynamics of spike-density was studied relative to seizures. All findings were compared against the results of a systematic review on ME, collecting 131 cases.
Interictal spikes appeared isolated in specific fronto-temporal independent components, whose cortical generators were located in the anterior temporal and inferior frontal lobe. In the patient undergoing seizure, ictal discharge relied in the same component, with the interictal spike-density decreasing before the seizure onset.
Our study shows how ICA can isolate neurophysiological features of ictal and interictal discharges in ME, highlighting a fronto-temporal localization and a suppression of spike-density preceding the seizure onset.