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1.
New Phytol ; 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38415863

RESUMO

Water scarcity, resulting from climate change, poses a significant threat to ecosystems. Syntrichia ruralis, a dryland desiccation-tolerant moss, provides valuable insights into survival of water-limited conditions. We sequenced the genome of S. ruralis, conducted transcriptomic analyses, and performed comparative genomic and transcriptomic analyses with existing genomes and transcriptomes, including with the close relative S. caninervis. We took a genetic approach to characterize the role of an S. ruralis transcription factor, identified in transcriptomic analyses, in Arabidopsis thaliana. The genome was assembled into 12 chromosomes encompassing 21 169 protein-coding genes. Comparative analysis revealed copy number and transcript abundance differences in known desiccation-associated gene families, and highlighted genome-level variation among species that may reflect adaptation to different habitats. A significant number of abscisic acid (ABA)-responsive genes were found to be negatively regulated by a MYB transcription factor (MYB55) that was upstream of the S. ruralis ortholog of ABA-insensitive 3 (ABI3). We determined that this conserved MYB transcription factor, uncharacterized in Arabidopsis, acts as a negative regulator of an ABA-dependent stress response in Arabidopsis. The new genomic resources from this emerging model moss offer novel insights into how plants regulate their responses to water deprivation.

2.
Science ; 383(6684): 782-788, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38359113

RESUMO

Competition, facilitation, and predation offer alternative explanations for successional patterns of migratory herbivores. However, these interactions are difficult to measure, leaving uncertainty about the mechanisms underlying body-size-dependent grazing-and even whether succession occurs at all. We used data from an 8-year camera-trap survey, GPS-collared herbivores, and fecal DNA metabarcoding to analyze the timing, arrival order, and interactions among migratory grazers in Serengeti National Park. Temporal grazing succession is characterized by a "push-pull" dynamic: Competitive grazing nudges zebra ahead of co-migrating wildebeest, whereas grass consumption by these large-bodied migrants attracts trailing, small-bodied gazelle that benefit from facilitation. "Natural experiments" involving intense wildfires and rainfall respectively disrupted and strengthened these effects. Our results highlight a balance between facilitative and competitive forces in co-regulating large-scale ungulate migrations.


Assuntos
Migração Animal , Antílopes , Equidae , Herbivoria , Parques Recreativos , Animais , Antílopes/fisiologia , Equidae/fisiologia , Poaceae , Quênia , Tanzânia
3.
Clin J Pain ; 40(2): 72-81, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37942728

RESUMO

OBJECTIVE: Randomized controlled trials indicate regional anesthesia (RA) improves postoperative outcomes with reduced pain and opioid consumption. Therefore, we hypothesized children who received RA, regardless of technique, would have reduced pain/opioid use in routine practice. METHODS: Using a retrospective cohort, we assessed the association of RA with perioperative outcomes in everyday practice at our academic pediatric hospital. Patients 18 years or below undergoing orthopedic, urologic, or general surgeries with and without RA from May 2014 to September 2021 were categorized as single shot, catheter based, or no block. Outcomes included intraoperative opioid exposure and dose, preincision anesthesia time, postanesthesia care unit (PACU) opioid exposure and dose, PACU antiemetic/antipruritic administration, PACU/inpatient pain scores, PACU/inpatient lengths of stay, and cumulative opioid exposure. Regression models estimated the adjusted association of RA with outcomes, controlling for multiple variables. RESULTS: A total of 11,292 procedures with 3160 RAs were included. Compared with no-block group, single-shot and catheter-based blocks were associated with opioid-free intraoperative anesthesia and opioid-free PACU stays. Post-PACU (ie, while inpatient), single-shot blocks were not associated with improved pain scores or reduced opioid use. Catheter-based blocks were associated with reduced PACU and inpatient opioid use until 24 hours postop, no difference in opioid use from 24 to 36 hours, and a higher probability of use from 36 to 72 hours. RA was not associated with reduced cumulative opioid consumption. DISCUSSION: Despite adjustment for confounders, the association of RA with pediatric pain/opioid use outcomes was mixed. Further investigation is necessary to maximize the benefits of RA.


Assuntos
Analgésicos Opioides , Anestesia por Condução , Humanos , Criança , Estudos Retrospectivos , Analgésicos Opioides/uso terapêutico , Dor Pós-Operatória/tratamento farmacológico , Anestesia por Condução/métodos , Anestésicos Locais
4.
J Dent ; 140: 104798, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38043721

RESUMO

OBJECTIVE: To investigate the effect of toothbrush head configuration and dentifrice slurry abrasivity on the development of simulated non-carious cervical lesions (NCCLs) in vitro. METHODS: Extracted premolars were randomly allocated into 15 groups (n = 16) generated by the association between toothbrush head configuration (flat-trimmed, rippled, cross-angled/multilevel/rubbers added, cross-angled/multilevel/flex head, feathered) and dentifrice slurry abrasivity (low/medium/high). Teeth were mounted on acrylic blocks and had their roots partially covered with acrylic resin, leaving 2-mm root surfaces exposed. Toothbrushing was performed for 35,000 and 65,000 double-strokes. Specimens were analyzed using non-contact profilometry for dental volume loss (mm3) and lesion morphology. Data was analyzed using ANOVA with pairwise comparisons and Kruskal-Wallis tests. RESULTS: The two-way interaction between toothbrush head configuration and slurry abrasivity was significant (p = 0.02). At 35,000 strokes, the flat-trimmed and cross-angled/multilevel/rubbers added toothbrushes caused the highest loss, when associated to the high-abrasive slurry (p<0.05); whereas cross-angled/multilevel/flex head showed the least loss, when associated to the low-abrasive (p<0.05). At 65,000, more dental loss was observed for all toothbrushes when associated to the high-abrasive slurry, with flat-trimmed causing the highest loss (p < 0.05). Lower dental loss rates were observed for cross-angled/multilevel/flex head associated to the low-abrasive slurry when compared to the other toothbrushes (p < 0.05), except to feathered (p = 0.14) and rippled (p = 0.08). Flat lesions (mean internal angle ± standard-deviation: 146.2°± 16.8) were mainly associated with low-abrasive slurry, while wedge-shaped lesions (85.8°± 18.8) were more frequent with medium- and high-abrasive slurries. CONCLUSION: The development, progression and morphology of simulated NCCLs were modulated by both toothbrush head configuration and dentifrice abrasivity. CLINICAL SIGNIFICANCE: Dental professionals should consider both the type of toothbrush and dentifrice abrasivity in the management plan of patients at risk of developing NCCLs.


Assuntos
Dentifrícios , Abrasão Dentária , Humanos , Escovação Dentária/efeitos adversos , Dentifrícios/efeitos adversos , Cremes Dentais , Abrasão Dentária/etiologia , Abrasão Dentária/patologia , Dente Pré-Molar/patologia
5.
Fitoterapia ; 172: 105754, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37992781

RESUMO

Canthium Lam. is a genus of flowering plants of the Rubiaceae family with about 80-102 species mainly distributed in Asia, tropical and subtropical Africa. The genus is closely related to Keetia E. Phillips and Psydrax Gaertn. and plants of this genus are used in folk medicine for the treatment of diarrhea, worms, leucorrhoea, constipation, snake bites, diabetes, hypertension, venereal diseases, and malaria. The present review covers a period of 52 years of biological and chemical investigations into the genus Canthium and has resulted in the isolation of about 96 secondary metabolites and several reported biological properties. For the Rubiaceae family, iridoids were reported as being the chemotaxonomic markers of this genus (∼25%). Other reported classes of compounds include alkaloids, flavonoids, phenolic compounds, cyanogenic glycosides, coumarins, sugar alcohols, lignans, triterpenoids, and benzoquinones. The main reported pharmacological properties of most species of this genus include antioxidant, antiplasmodial, antipyretic, anti-inflammatory, antidiabetic, neuroprotective and antimicrobial activities with the latter being the most prominent. Considering the diversity of compounds reported from plants of this genus and their wide range of biological activities, it is considered to be worthy to further investigate them for the discovery of potentially new and cost effective drugs.


Assuntos
Fitoterapia , Rubiaceae , Etnofarmacologia , Extratos Vegetais/química , Estrutura Molecular , Compostos Fitoquímicos
6.
J Dent ; 141: 104827, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159901

RESUMO

OBJECTIVES: To synthesize and characterize a novel dentin adhesive containing Beta-Tricalcium Phosphate (ß-TCP) nanoparticles and test its ability to reduce dentin permeability (dP). METHODS: Experimental adhesives were prepared by mixing Bis-GMA, TEGDMA, HEMA (50/25/25 wt.%), photo-initiators, and inhibitors. The following groups were tested: Experimental adhesives without ß-TCP (Exp.); with 10 wt.% ß-TCP (Exp.10 wt.% ß-TCP); with 15 wt.% ß-TCP (Exp.15 wt.% ß-TCP), Scotchbond Multi-Purpose (SBMP) and Clearfil SE Protect Bond (CFPB). Degree of conversion (DC%, 10 and 20 s); Flexural Strength (FS), Knoop Hardness (KHN), and Cell Viability (OD%) tests were performed. dP was evaluated by hydraulic conductance, using human dentin disks (n=12), at three-time intervals: post-EDTA (T0); post-treatment (T1); and post-erosion/abrasion cycling (T2). Data were statistically analyzed (α=0.05). RESULTS: For all groups, exposure time for 20 s presented a higher DC% than for 10 s. For FS, filled adhesives did not differ from unfilled and from CFPB. Experimental adhesives did not differ among them and showed lower KHN than the commercial products. Cell viability did not differ among adhesives, except Exp. 15 wt.%, which showed lower OD% than Exp., Exp. 10% and, CFPB. For dP, only Exp.10 and 15 wt.% ß-TCP did not present difference between the times T1 and T2. After cycling, Exp.10 wt.% ß-TCP presented lower permeability than Exp. and CFPB. CONCLUSIONS: The incorporation of 10 wt.% ß-TCP nanoparticles into the resin-based dental material did not affect its mechanical properties and biocompatibility, and promoted the greatest reduction in dentin permeability, sustaining this effect under erosive/abrasive challenges. CLINICAL SIGNIFICANCE: A novel resin-based dental material containing ß-TCP nanoparticles was able to reduce dentin permeability, maintaining its efficacy after erosive/abrasive challenges. The synthesized material did not affect dental pulp cell viability and might be promising for other conditions that require dental remineralization, such as tooth wear and dental caries.


Assuntos
Fosfatos de Cálcio , Colagem Dentária , Cárie Dentária , Nanopartículas , Humanos , Adesivos Dentinários/química , Permeabilidade da Dentina , Cimentos de Resina/farmacologia , Cimentos de Resina/química , Teste de Materiais , Dentina/química , Resistência à Tração , Cimentos Dentários/química
7.
Personal Neurosci ; 6: e4, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38107780

RESUMO

The aim of this study was to better understand the relation of schizotypy traits with sensory gating ability in a sample of community-dwelling individuals with high and low schizotypy traits. Sensory gating was assessed through the paired click paradigm and mid-latency evoked responses (i.e., P50, N100, P200), while schizotypy traits were assessed through the SPQ-BR which was used to classify participants into "high" and "low" schizotypy groups. Based on prior work, we hypothesized that those with the highest schizotypy scores would have reduced sensory gating ability. While this study does not show differences between relatively low and high schizotypy groups on sensory gating ability, it does suggest that our participants may have been experiencing deficits in attention allocation, a downstream cognitive processing measure. Scores on the SPQ-BR suggest that our sample was not close to the high end of the schizotypy traits which may help explain why no differences were found. This research shows the importance of including all levels of schizotypy ratings in clinical research as we can gain a clearer view of the impact of schizotypy on the brain and cognitive functioning in those with "high" levels of schizotypy. Additionally, this work highlights the importance of including measures of important factors such as impulsivity and sensation-seeking to better understand what aspects of schizotypy may be driving these sensory gating alterations reported in the literature.

8.
Brain Spine ; 3: 102704, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38105803

RESUMO

Introduction: Targeted Temperature Management (TTM) to normothermia is widely used in traumatic brain injury (TBI). We investigated the effects to of TTM to normothermia patients with TBI (GCS≤12) monitored with multimodality monitoring, to better understand the physiological consequences of this intervention. Research question: In TBI patients cooled to normothermia and in which brain oxygenation deteriorates, are there changes in physiological parameters which are pertinent to brain oxygenation? Material and method: 102 TBI patients with continuous recordings of intracranial pressure (ICP) and brain oxygen tension (PbtO2) were studied retrospectively. Non-continuous arterial carbon dioxide (PaCO2) and oxygen (PaO2) tensions, and core body temperature (Tc) were added. PaO2 and PaCO2 were also corrected for Tc. Transitions from elevated Tc to normothermia were identified in 39 patients. The 8 h pre and post the transition to normothermia were compared. Data is given as median [IQR] or mean (SD). Results: Overall, normothermia reduced ICP (12 [9-18] -11 [8-17] mmHg, p < 0.009) and Tcore (38.3 [0.3]-36.9 [0.4] oC, p < 0.001), but not PbtO2 (23.3 [16.6]-24.4 [17.2-28.7] mmHg, NS). Normothermia was associated with a fall in PbtO2 in 18 patients (24.5 [9.3] -20.8 [7.6] mmHg). Only in those with a fall in PbtO2 with cooling did ICP (15 [10.8-18.5] -12 [7.8-17.3] mmHg, p = 0.002), and temperature corrected PaCO2 (5.3 [0.5]- 4.9 [0.8] kPa, p = 0.001) decrease. Discussion and conclusion: A reduction in PbtO2 was only present in the subgroup of patients with a fall in temperature corrected PaCO2 with cooling. This suggests that even modest temperature changes could result in occult hyperventilation in some patients. pH stat correction of ventilation may be an important factor to consider in future TTM protocols.

9.
Animals (Basel) ; 13(11)2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37889800

RESUMO

Camera traps and drone surveys both leverage advancing technologies to study dynamic wildlife populations with little disturbance. Both techniques entail strengths and weaknesses, and common camera trap methods can be confounded by unrealistic assumptions and prerequisite conditions. We compared three methods to estimate the population density of white-tailed deer (Odocoileus virgnianus) in a section of Pilot Mountain State Park, NC, USA: (1) camera trapping using mark-resight ratios or (2) N-mixture modeling and (3) aerial thermal videography from a drone platform. All three methods yielded similar density estimates, suggesting that they converged on an accurate estimate. We also included environmental covariates in the N-mixture modeling to explore spatial habitat use, and we fit models for each season to understand temporal changes in population density. Deer occurred in greater densities on warmer, south-facing slopes in the autumn and winter and on cooler north-facing slopes and in areas with flatter terrain in the summer. Seasonal density estimates over two years suggested an annual cycle of higher densities in autumn and winter than in summer, indicating that the region may function as a refuge during the hunting season.

10.
Clin Pediatr (Phila) ; : 99228231196473, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37671731

RESUMO

Poorly controlled acute pain is associated with worsened patient outcomes. Prior studies suggest that acute pain is a common complaint among hospitalized pediatric patients, but recent studies with substantial numbers of patients from US hospitals are lacking. We retrospectively reviewed inpatients at a single academic children's hospital during twelve 24-hour periods in 2021. Outcomes were assessed for patients on non-intensive care unit (ICU) inpatient floors and in ICUs. The primary outcome was any presence of moderate to severe pain. Of 1355 patients on a non-ICU inpatient floor and 485 patients in the ICU, 23.5% and 58.6%, respectively, had ≥1 moderate to severe pain score during the 24-hour analysis period. While the mean pain score was low for the majority of patients, moderate to severe pain is frequent in hospitalized children. Future studies may focus on identification of variables associated with pediatric inpatients at risk of moderate to severe pain as well as improved pain prevention and reduction strategies.

11.
Phys Rev Lett ; 131(4): 041002, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37566836

RESUMO

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9 GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36 GeV/c^{2}, rejecting cross sections above 9.2×10^{-48} cm at the 90% confidence level.

12.
Diagnostics (Basel) ; 13(15)2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37568931

RESUMO

This study proposed using enamel surface texture and thickness for the objective detection and monitoring of erosive tooth wear (ETW), comparing them to the standard subjective Basic Erosive Wear Evaluation (BEWE). Thirty-two subjects (n = 597 teeth) were enrolled in this longitudinal observational clinical study. Enamel thickness (by cross-polarization optical coherence tomography, CP-OCT) and 3D dental microwear parameters, i.e., area-scale fractal complexity (Asfc), anisotropy (Str), and roughness (Sa) (by white-light scanning confocal profilometry), were obtained from buccal surfaces. Buccal, occlusal, and lingual surfaces were scored for BEWE and the maximum score per tooth (BEWEMax) was determined at baseline and 12 months (M12). Data outcome relationships were evaluated (alpha = 0.05). Enamel thickness decreased (p < 0.001), BEWE scores, Sa, and Str increased (p < 0.001), while Asfc did not change at M12. Baseline BEWEBuccal correlated strongly with BEWEMax (r = 0.86, p < 0.001) and moderately with BEWELingual (r = 0.42, p < 0.001), but not with enamel thickness (r = 0.03, p = 0.43). Change (Δ) in surface texture outcomes correlated poorly but significantly with ΔBEWEBuccal (r = -0.15-0.16, p < 0.001) and did not correlate with Δenamel thickness (r = 0.02-0.09, p > 0.06). Teeth with BEWE progression revealed a greater increase in ΔSa and ΔStr. These findings suggest that enamel surface roughness can potentially determine ETW severity, and CP-OCT may be relevant for clinically monitoring enamel thickness.

13.
Acta Stomatol Croat ; 57(1): 12-21, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37288154

RESUMO

Objectives: Molar crown wear is often used in bioarchaeological research as a proxy for age at death. However, a small number of researchers have used premolars or compared the application of different methods of relative age estimation. Material and methods: Using a sample of 197 previously extracted maxillary first premolars from US dental patients, we considered three protocols for estimating age: the Bang and Ramm/Liversidge and Molleson (BRLM) age estimate method, occlusal topographic analysis, and the Smith system of macrowear scoring. A previous study utilizing the Bang and Ramm method yielded an age estimate range of 9.4 to 10.8 years for the sample. Results: Our analyses showed no associations between occlusal topography parameters (occlusal slope, relief, or faceting) and BRLM age estimates, but some concordance was found between Smith scoring and BRLM ages estimates and between Smith scoring and occlusal topography parameters. Conclusion: The results of the present study suggest that relationships between gross tooth wear, tooth shape, and dental age estimates are complex, and available methods should be considered together to gain a more comprehensive understanding of how teeth change their shape with wear throughout the lifecourse.

14.
Clin Radiol ; 78(9): 697-702, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37331849

RESUMO

AIM: To describe the imaging features of fasciitis ossificans and its histopathological features. MATERIALS AND METHODS: Using a word search of existing pathology reports at the Mayo Clinic, six cases of fasciitis ossificans were identified. The clinical history, histology, and available imaging of the affected area were reviewed. RESULTS: Imaging consisted of radiographs, mammograms, ultrasound images, bone scintigraphs, computed tomography (CT), and magnetic resonance imaging (MRI) images. All cases demonstrated a soft-tissue mass. The characteristic MRI appearance was a T2 hyperintense enhancing mass with surrounding soft-tissue oedema. Peripheral calcifications were seen on radiographs, CT, and/or ultrasound. Histological sections showed distinct zonation, with nodular fasciitis-like zones of myofibroblastic proliferation, which merged with osteoblasts that rim the ill-defined trabeculae of woven bone and became continuous with the mature lamellar bone surrounded by a thin layer of compressed fibrous tissue. CONCLUSION: Imaging features of fasciitis ossificans are that of an enhancing soft-tissue mass located within a fascial plane with prominent surrounding oedema and mature peripheral calcification. Imaging and histology are that of myositis ossificans but occurring within the fascia. It is important that radiologists are aware of the diagnosis of fasciitis ossificans and appreciate its similarity to myositis ossificans. This is particularly important in anatomical locations with fascias but no muscle. Given the radiographic and histological overlap between these entities, nomenclature that encompasses both could be considered in the future.


Assuntos
Calcinose , Fasciite , Miosite Ossificante , Humanos , Miosite Ossificante/diagnóstico por imagem , Miosite Ossificante/patologia , Diagnóstico Diferencial , Fasciite/diagnóstico por imagem , Fasciite/patologia , Tomografia Computadorizada por Raios X , Calcinose/diagnóstico por imagem , Imageamento por Ressonância Magnética , Edema/diagnóstico
16.
Curr Biol ; 33(11): R584-R610, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37279691

RESUMO

Large herbivores play unique ecological roles and are disproportionately imperiled by human activity. As many wild populations dwindle towards extinction, and as interest grows in restoring lost biodiversity, research on large herbivores and their ecological impacts has intensified. Yet, results are often conflicting or contingent on local conditions, and new findings have challenged conventional wisdom, making it hard to discern general principles. Here, we review what is known about the ecosystem impacts of large herbivores globally, identify key uncertainties, and suggest priorities to guide research. Many findings are generalizable across ecosystems: large herbivores consistently exert top-down control of plant demography, species composition, and biomass, thereby suppressing fires and the abundance of smaller animals. Other general patterns do not have clearly defined impacts: large herbivores respond to predation risk but the strength of trophic cascades is variable; large herbivores move vast quantities of seeds and nutrients but with poorly understood effects on vegetation and biogeochemistry. Questions of the greatest relevance for conservation and management are among the least certain, including effects on carbon storage and other ecosystem functions and the ability to predict outcomes of extinctions and reintroductions. A unifying theme is the role of body size in regulating ecological impact. Small herbivores cannot fully substitute for large ones, and large-herbivore species are not functionally redundant - losing any, especially the largest, will alter net impact, helping to explain why livestock are poor surrogates for wild species. We advocate leveraging a broad spectrum of techniques to mechanistically explain how large-herbivore traits and environmental context interactively govern the ecological impacts of these animals.


Assuntos
Ecossistema , Herbivoria , Animais , Humanos , Herbivoria/fisiologia , Biomassa , Biodiversidade , Plantas
17.
Science ; 380(6652): 1338-1343, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37384687

RESUMO

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos. We searched for neutrino emission using machine learning techniques applied to 10 years of data from the IceCube Neutrino Observatory. By comparing diffuse emission models to a background-only hypothesis, we identified neutrino emission from the Galactic plane at the 4.5σ level of significance. The signal is consistent with diffuse emission of neutrinos from the Milky Way but could also arise from a population of unresolved point sources.

18.
Carbohydr Polym ; 311: 120785, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37028851

RESUMO

Understanding water absorbency in paper is challenging as fibre swelling and out-of-plane deformation occur simultaneously during liquid imbibition. Liquid absorption is commonly accessed by gravimetric tests, which provides limited information on the local spatial and temporal distribution of fluid in the substrate. In this work, we developed iron tracers to map liquid imbibition in paper by in situ precipitation of iron oxide nanoparticles during passage of the wetting front. The iron oxide tracers were found to be robustly attached to the cellulosic fibres. After liquid absorption tests, absorbency was investigated by mapping the distribution of iron in 3D using X-ray micro-computed tomography (µCT) and in 2D using energy-dispersive X-ray spectroscopy. We demonstrate a difference in tracer distribution between the wetting front and the fully saturated region supporting that imbibition proceeds in two phases, i.e. liquid percolation through the cell wall initially prior to filling of the external pore spaces. Critically, we demonstrate that these iron tracers enhance image contrast and allow for new imaging modalities in µCT for fibre networks.

19.
Org Lett ; 25(9): 1364-1369, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36856659

RESUMO

The rearrangement pathways of two alkylidene carbenes appended to an oxa or thiacyclopentane into the corresponding heterocyclohexynes were elucidated using 13C-labeling experiments. Both carbenes exhibited a preference for migration of the allylic carbon bound to the heteroatom. Anomeric interactions involving a heteroatom lone pair and antibonding orbital of the migrating bond and inductive destabilization of the minor migratory pathway are discussed as plausible reasons for the observed trends.

20.
Anesth Analg ; 136(6): 1189-1197, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36857212

RESUMO

BACKGROUND: Children increasingly undergo diagnostic imaging procedures, sometimes with general anesthesia (GA). It is unknown whether the use of GA differs by race/ethnicity among children undergoing magnetic resonance imaging (MRI) scans. METHODS: This is a retrospective cohort study of GA use for pediatric patients from 0 to 21 years of age who underwent MRIs from January 1, 2004 to May 31, 2019. The study sample was stratified into 5 age groups: 0 to 1, 2 to 5, 6 to 11, 12 to 18, and 19 to 21. Analysis was performed separately for each age group. RESULTS: Among 457,314 MRI patients, 29,108 (6.4%) had GA. In the adjusted regression models, Asian patients aged 0 to 1 (adjusted relative risk [aRR] [95% confidence interval {CI}] of 1.11 [1.05-1.17], P < .001) and aged 2 to 5 (aRR [95% CI], 1.04 [1.00-1.09], P = .03), Black patients aged 2 to 5 (aRR [95% CI], 1.04 [1.01-1.08], P = .02) and aged 6 to 11 (aRR [95% CI], 1.13 [1.06-1.20], P < .001), and Hispanic patients aged 0 to 1 (aRR [95% CI], 1.07 [1.03-1.12], P < .001) were more likely to receive GA for MRIs than White patients. CONCLUSIONS: Asian, Black, and Hispanic children of some ages were more likely to receive GA during MRI scans than White children in the same age group. Future research is warranted to delineate whether this phenomenon signifies disparate care for children based on their race/ethnicity.


Assuntos
Negro ou Afro-Americano , População Branca , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Adulto Jovem , Etnicidade , Imageamento por Ressonância Magnética , Estudos Retrospectivos , Anestesia Geral , Asiático , Hispânico ou Latino
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