4-Alkynyl indoles, when treated with a benzylidene malonate or a donor–acceptor cyclopropane in the presence of a zinc halide, furnished 3,4-hexannylated or 3,4-heptannulated products, respectively, ...in fair to excellent yields. The reaction proceeds via a tandem addition/Conia-ene cyclization.
Purpose To determine the effect of different types of capsulotomies on hip rotational biomechanical characteristics. Methods Seven fresh-frozen cadaveric hip specimens were thawed and dissected, ...leaving the hip capsule and labrum intact. The femur was transected and potted, and each specimen was placed in a custom loading apparatus that allowed for adjustment of flexion, extension, and axial rotation of the femur. Six reflective infrared markers were attached to the specimens to track the motion of the femoral head with respect to the acetabulum in real time, and external rotation was produced by applying a torque of 10 Nm to the hip specimens. Data analysis was performed using the 3-dimensional position of the markers in space. The specimens were tested in neutral flexion and 40° of flexion in the following capsular states: intact, interportal capsulotomy, T-capsulotomy, repaired capsulotomy, and capsulectomy. Paired t tests and analysis of variance were used with an α value of .05 set as significant. Results With the hip in neutral flexion, there was increased external rotation with a T-capsulotomy (91.1° ± 20.3°, P = .029) and capsulectomy (91.9° ± 19.6°, P = .015) compared with the intact hip (83.2° ± 20.5°). After complete repair of the T-capsulotomy (87.4° ± 20.6°), there was no significant difference in external rotation compared with the intact hip. No significant differences were seen between groups at 40° of hip flexion. Conclusions A T-capsulotomy showed significantly increased external rotation versus the intact and interportal capsulotomy states. The repaired T-capsulotomy restored the rotational profile back to the native state. Clinical Relevance Many methods of capsular treatment during hip arthroscopy exist. Capsulotomy and capsulectomy do not restore the external rotation restraint of the hip back to its native state.
Antibody-based interventions against SARS-CoV-2 could limit morbidity, mortality, and possibly transmission. An anticipated correlate of such countermeasures is the level of neutralizing antibodies ...against the SARS-CoV-2 spike protein, which engages with host ACE2 receptor for entry. Using an infectious molecular clone of vesicular stomatitis virus (VSV) expressing eGFP as a marker of infection, we replaced the glycoprotein gene (G) with the spike protein of SARS-CoV-2 (VSV-eGFP-SARS-CoV-2) and developed a high-throughput-imaging-based neutralization assay at biosafety level 2. We also developed a focus-reduction neutralization test with a clinical isolate of SARS-CoV-2 at biosafety level 3. Comparing the neutralizing activities of various antibodies and ACE2-Fc soluble decoy protein in both assays revealed a high degree of concordance. These assays will help define correlates of protection for antibody-based countermeasures and vaccines against SARS-CoV-2. Additionally, replication-competent VSV-eGFP-SARS-CoV-2 provides a tool for testing inhibitors of SARS-CoV-2 mediated entry under reduced biosafety containment.
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•Vesicular stomatitis virus encoding the SARS-CoV-2 spike replicates to high titers•Virus propagation is enhanced by a truncation in the cytoplasmic tail of the spike•Neutralization can be assessed by BSL2 and BSL3 high-throughput assays•SARS-CoV-2- and VSV-SARS-CoV-2-based neutralization assays correlate
Case, Rothlauf et al. generate a replication-competent vesicular stomatitis virus (VSV) expressing the SARS-CoV-2 spike and compare the neutralizing activity of antibodies with VSV-SARS-CoV-2 to fully infectious SARS-CoV-2. They show that VSV-SARS-CoV-2 is a useful BSL2 surrogate virus, as neutralization profiles strongly correlate with focus-reduction neutralization tests using SARS-CoV-2.
Abstract Background Non-invasive brain stimulation enables the induction of neuroplasticity in humans, however, with so far restricted duration of the respective cortical excitability modifications. ...Conventional anodal transcranial direct current stimulation (tDCS) protocols including one stimulation session induce NMDA receptor-dependent excitability enhancements lasting for about 1 h. Objective We aimed to extend the duration of tDCS effects by periodic stimulation, consisting of two stimulation sessions, since periodic stimulation protocols are able to induce neuroplastic excitability alterations stable for days or weeks, termed late phase long term potentiation (l-LTP), in animal slice preparations. Since both, l-LTP and long term memory formation, require gene expression and protein synthesis, and glutamatergic receptor activity modifications, l-LTP might be a candidate mechanism for the formation of long term memory. Methods The impact of two consecutive tDCS sessions on cortical excitability was probed in the motor cortex of healthy humans, and compared to that of a single tDCS session. The second stimulation was applied without an interval (temporally contiguous tDCS), during the after-effects of the first stimulation (during after-effects; 3, or 20 min interval), or after the after-effects of the first stimulation had vanished (post after-effects; 3 or 24 h interval). Results The during after-effects condition resulted in an initially reduced, but then relevantly prolonged excitability enhancement, which was blocked by an NMDA receptor antagonist. The other conditions resulted in an abolishment, or a calcium channel-dependent reversal of neuroplasticity. Conclusion Repeated tDCS within a specific time window is able to induce l-LTP-like plasticity in the human motor cortex.
Fish are the most diverse and widely distributed vertebrates, yet little is known about the microbial ecology of fishes nor the biological and environmental factors that influence fish microbiota. To ...identify factors that explain microbial diversity patterns in a geographical subset of marine fish, we analyzed the microbiota (gill tissue, skin mucus, midgut digesta and hindgut digesta) from 101 species of Southern California marine fishes, spanning 22 orders, 55 families and 83 genera, representing ~25% of local marine fish diversity. We compare alpha, beta and gamma diversity while establishing a method to estimate microbial biomass associated with these host surfaces. We show that body site is the strongest driver of microbial diversity while microbial biomass and diversity is lowest in the gill of larger, pelagic fishes. Patterns of phylosymbiosis are observed across the gill, skin and hindgut. In a quantitative synthesis of vertebrate hindguts (569 species), we also show that mammals have the highest gamma diversity when controlling for host species number while fishes have the highest percent of unique microbial taxa. The composite dataset will be useful to vertebrate microbiota researchers and fish biologists interested in microbial ecology, with applications in aquaculture and fisheries management.
In molecular phylogenetics, partition models and mixture models provide different approaches to accommodating heterogeneity in genomic sequencing data. Both types of models generally give a superior ...fit to data than models that assume the process of sequence evolution is homogeneous across sites and lineages. The Akaike Information Criterion (AIC), an estimator of Kullback-Leibler divergence, and the Bayesian Information Criterion (BIC) are popular tools to select models in phylogenetics. Recent work suggests that AIC should not be used for comparing mixture and partition models. In this work, we clarify that this difficulty is not fully explained by AIC misestimating the Kullback-Leibler divergence. We also investigate the performance of the AIC and BIC at comparing amongst mixture models and amongst partition models. We find that under nonstandard conditions (i.e. when some edges have small expected number of changes), AIC underestimates the expected Kullback-Leibler divergence. Under such conditions, AIC preferred the complex mixture models and BIC preferred the simpler mixture models. The mixture models selected by AIC had a better performance in estimating the edge length, while the simpler models selected by BIC performed better in estimating the base frequencies and substitution rate parameters. In contrast, AIC and BIC both prefer simpler partition models over more complex partition models under nonstandard conditions, despite the fact that the more complex partition model was the generating model. We also investigated how mispartitioning (i.e., grouping sites that have not evolved under the same process) affects both the performance of partition models compared with mixture models and the model selection process. We found that as the level of mispartitioning increases, the bias of AIC in estimating the expected Kullback-Leibler divergence remains the same, and the branch lengths and evolutionary parameters estimated by partition models become less accurate. We recommend that researchers are cautious when using AIC and BIC to select among partition and mixture models; other alternatives, such as cross-validation and bootstrapping, should be explored, but may suffer similar limitations AIC; BIC; mispartitioning; partitioning; partition model; mixture model.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The neuromodulator dopamine plays an important role in synaptic plasticity. The effects are determined by receptor subtype specificity, concentration level, and the kind of neuroplasticity induced. ...D1-like receptors have been proposed to be involved in cognitive processes via their impact on plasticity. Cognitive studies in humans and animals revealed a dosage-dependent effect of D1-like receptor activation on task performance. In humans, D1-like receptor activation re-establishes plasticity under D2 receptor block. However, a dosage-dependent effect has not been explored so far. To determine the impact of the amount of D1-like receptor activation on neuroplasticity in humans, we combined sulpiride, a selective D2 receptor antagonist, with the dopamine precursor l-DOPA (25, 100, and 200 mg) or applied placebo medication. The impact on plasticity induced by anodal and cathodal transcranial direct current stimulation (tDCS) was compared with the impact on plasticity induced by excitatory and inhibitory paired associative stimulation (PAS) at the primary motor cortex of healthy humans. Stimulation-generated cortical excitability alterations were monitored by transcranial magnetic stimulation-induced motor-evoked potential amplitudes. D1-like receptor activation produced an inverted U-shaped dose-response curve on plasticity induced by both facilitatory tDCS and PAS. For excitability-diminishing tDCS and PAS, aftereffects were abolished or converted trendwise into facilitation. These data extend findings of dose-dependent inverted U-shaped effects of D1 receptor activation on neuroplasticity of the motor cortex.
Atlantic tarpon (Megalops atlanticus) are capable of long-distance migrations (hundreds of kilometers) but also exhibit resident behaviors in estuarine and coastal habitats. The aim of this study was ...to characterize the spatial distribution of juvenile tarpon and identify migration pathways of adult tarpon in the northern Gulf of Mexico. Spatial distribution of juvenile tarpon was investigated using gillnet data collected by Texas Parks and Wildlife Department (TPWD) over the past four decades. Generalized additive models (GAMs) indicated that salinity and water temperature played a significant role in tarpon presence, with tarpon occurrences peaking in the fall and increasing over the past four decades in this region. Adult tarpon caught off Texas (n = 40) and Louisiana (n = 4) were tagged with acoustic transmitters to characterize spatial and temporal trends in their movements and migrations. Of the 44 acoustic transmitters deployed, 18 of the individuals were detected (n = 16 west of the Mississippi River Delta and n = 2 east of the Mississippi River Delta). Tarpon tagged west of the Mississippi River Delta off Texas migrated south in the fall and winter into areas of south Texas and potentially into Mexico, while individuals tagged east of the delta migrated into Florida during the same time period, suggesting the presence of two unique migratory contingents or subpopulations in this region. An improved understanding of the habitat requirements and migratory patterns of tarpon inhabiting the Gulf of Mexico is critically needed by resource managers to assess the vulnerability of each contingent to fishing pressure, and this information will guide multi-state and multi-national conservation efforts to rebuild and sustain tarpon populations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We describe the synthesis and characterization of high‐performance, superparamagnetic, iron oxide nanoparticle‐based, heavy metal sorbents, which demonstrate excellent affinity for the separation of ...heavy metals in contaminated water systems (i.e., spiked Columbia River water). The magnetic nanoparticle sorbents were prepared from an easy‐to‐synthesize iron oxide precursor, followed by a simple, one‐step ligand exchange reaction to introduce an affinity ligand to the nanoparticle surface that is specific to a heavy metal or class of heavy metal contaminants. The engineered magnetic nanoparticle sorbents have inherently high active surface areas, allowing for increased binding capacities. To demonstrate the performance of the nanoparticle sorbents, river water was spiked with specific metals and exposed to low concentrations of the functionalized nanoparticles. In almost all cases, the nanoparticles were found to be superior to commercially available sorbent materials as well as the unfunctionalized iron oxide nanoparticles.
Superparamagnetic iron man: The synthesis and characterization of superparamagnetic, iron oxide nanoparticle‐based heavy metal sorbents with various surface chemistries, which demonstrate excellent affinity for the separation of heavy metals in contaminated natural water systems is described. Our method has the unique advantage that the analyte reactivity is incorporated into the nanoparticle ligand shell without altering the desirable properties of the starting nanoparticle.
Reverse osmosis (RO)-based desalination and advanced water purification facilities have inherent challenges associated with concentrate management and disposal. Although enhanced permeate recovery ...and concentrate minimization are desired, membrane scaling due to inorganic constituents, such as silica, calcium, phosphate, and iron, hinders the process. To solve this problem, a new diatom-based photobiological process has been developed to remove these scaling constituents by biological uptake and precipitation. In this study, RO concentrate samples were collected from a full-scale advanced water reclamation facility in California and were treated in 3.8 and 57 L photobioreactors inoculated with a brackish water diatom Pseudostaurosira trainorii PEWL001 using light-emitting diode bulbs or natural sunlight as a light source. The photobiological treatment removed 95% of reactive silica and 64% of calcium and enabled additional water recovery using a secondary RO at a recovery rate up to 66%. This represents 95% overall recovery, including 85% recovery in the primary RO unit. In addition to the scaling constituents, the photobiological treatment removed 12 pharmaceuticals and personal care products, as well as N-nitrosodimethylamine, from RO concentrate samples primarily via photolysis. This novel approach has a strong potential for application to brackish water desalination and advanced water purification in arid and semiarid areas.
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