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1.
Sci Rep ; 13(1): 9923, 2023 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-37337031

RESUMEN

Chronic wounds are characterized by a persistent, hyper-inflammatory environment that prevents progression to regenerative wound closure. Such chronic wounds are especially common in diabetic patients, often requiring distal limb amputation, but occur in non-diabetic, elderly patients as well. Induced expression of HoxA3, a member of the Homeobox family of body patterning and master regulatory transcription factors, has been shown to accelerate wound closure in diabetic mice when applied topically as a plasmid encased in a hydrogel. We now provide independent replication of those foundational in vivo diabetic wound closure studies, observing 16% faster healing (3.3 mm wounds vs 3.9 mm wounds at Day 9 post original injury of 6 mm diameter) under treatment with observable microscopic benefits. We then expand upon these findings with minimal dose threshold estimation of 1 µg HoxA3 plasmid delivered topically at a weekly interval. Furthermore, we observed similarities in natural wound healing rates between aged non-diabetic mice and young diabetic mice, which provided motivation to test topical HoxA3 plasmid in aged non-diabetic mice. We observed that HoxA3 treatment achieved complete wound closure (0 mm diameter) at 2 weeks whereas untreated wounds were only 50% closed (3 mm wound diameter). We did not observe any gross adverse effects macroscopically or via histology in these short studies. Whether as a plasmid or future alternative modality, topical HoxA3 is an attractive translational candidate for chronic wounds.


Asunto(s)
Diabetes Mellitus , Cicatrización de Heridas , Animales , Ratones , Proteínas de Unión al ADN/farmacología , Factores de Transcripción/farmacología , Cicatrización de Heridas/genética
2.
S Afr Med J ; 113(2): 69-74, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36757070

RESUMEN

BACKGROUND: Up to a quarter of inpatients in high-income countries (HICs) self-report beta-lactam allergy (BLA), which if incorrect,increases the use of alternative antibiotics, worsening individual health outcomes and driving bacterial resistance. In HICs, up to 95% ofself-reported BLAs are incorrect. The epidemiology of BLA in low- and middle-income African countries is unknown. OBJECTIVES: To describe the epidemiology and de-labelling outcomes of self-reported BLA in hospitalised South African (SA) patients. METHODS: Point-prevalence surveys were conducted at seven hospitals (adult, paediatric, government and privately funded, district andtertiary level) in Cape Town, SA, between April 2019 and June 2021. Ward prescription records and in-person interviews were conductedto identify and risk-stratify BLA patients using the validated PEN-FAST tool. De-labelling was attempted at the tertiary allergy clinic atGroote Schuur Hospital. RESULTS: A total of 1 486 hospital inpatients were surveyed (1 166 adults and 320 children). Only 48 patients (3.2%) self-reported a BLA,with a higher rate in private than in government-funded hospitals (6.3% v. 2.8%; p=0.014). Using the PEN-FAST tool, only 10.4% (n=5/48)of self-reported BLA patients were classified as high risk for true penicillin hypersensitivity. Antibiotics were prescribed to 70.8% (n=34/48)of self-reported BLA patients, with 64.7% (n=22/34) receiving a beta-lactam. Despite three attempts to contact patients for de-labelling atthe allergy clinic, only 3/36 underwent in vivo testing, with no positive results, and 1 patient proceeded to a negative oral challenge. CONCLUSION: Unlike HICs, self-reported BLA is low among inpatients in SA. The majority of those who self-reported BLA were low risk fortype 1 hypersensitivity, but outpatient de-labelling efforts were largely unsuccessful.


Asunto(s)
Hipersensibilidad a las Drogas , Hipersensibilidad , Adulto , Humanos , Niño , beta-Lactamas/efectos adversos , Autoinforme , Sudáfrica/epidemiología , Pruebas Cutáneas/métodos , Antibacterianos/efectos adversos , Penicilinas , Hipersensibilidad a las Drogas/epidemiología , Hospitales Públicos , Hospitales Privados , Gobierno
3.
Front Chem ; 10: 976635, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36092655

RESUMEN

Flerovium (Fl, element 114) is the heaviest element chemically studied so far. To date, its interaction with gold was investigated in two gas-solid chromatography experiments, which reported two different types of interaction, however, each based on the level of a few registered atoms only. Whereas noble-gas-like properties were suggested from the first experiment, the second one pointed at a volatile-metal-like character. Here, we present further experimental data on adsorption studies of Fl on silicon oxide and gold surfaces, accounting for the inhomogeneous nature of the surface, as it was used in the experiment and analyzed as part of the reported studies. We confirm that Fl is highly volatile and the least reactive member of group 14. Our experimental observations suggest that Fl exhibits lower reactivity towards Au than the volatile metal Hg, but higher reactivity than the noble gas Rn.

4.
Appl Radiat Isot ; 173: 109711, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33848751

RESUMEN

This paper describes the experimental results for an energy tuning assembly created to modify the National Ignition Facility deuterium-tritium fusion neutron source into a notional thermonuclear and prompt fission neutron spectrum, which has applications in integral measurements, nuclear data benchmarks, and radiation effects on microelectronics. The Monte Carlo neutron transport utilized MCNP5 to estimate the ETA-modified fluence using the ENDF-B/VIII.0 and IRDFF-II continuous energy nuclear data libraries, and SCALE Sampler was used to estimate the systematic nuclear data covariance using ENDF-B/VII.1 and IRDFF-II in a 252-group structure. The experiment fielded eight activation foils and a highly enriched uranium sample. This provided fifteen reaction channels that were used in a forward-fit comparison to the modeled results and to unfold the neutron spectrum using STAYSL. Gamma-ray spectrometry was performed on the activation and highly enriched uranium foils, and the reduced χ2 between the modeled and experimental values was 1.21. The results from the STAYSL unfold, reduced χ2=1.62, indicated that the modeled neutron spectrum was achieved and the systematic nuclear data uncertainty associated with the neutron transport and activation product cross sections was representative of the experiment. Integral cumulative fission product yield data were collected for 37 mass chains with a combination of gamma-ray spectrometry and radiochemical analysis. Fission product analysis was generally in agreement with two models using a semi-empirical fit and the General Observables of Fission code, with the exception of mass chains 88, 109, 111, 112, 113, 129, 139, 142, 144, 151, and 156.

5.
Appl Radiat Isot ; 143: 163-175, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30447627

RESUMEN

Nuclear fusion experiments performed at the National Ignition Facility produce radioactive debris, arising in reactions of fast neutrons with the target assembly. We have found that postshot debris collections are fractionated, such that isotope ratios in an individual debris sample may not be representative of the radionuclide inventory produced by the experiment. We discuss the potential sources of this fractionation and apply isotope-correlation techniques to calculate unfractionated isotope ratios that are used in measurements of nuclear reaction cross sections.

6.
Rev Sci Instrum ; 89(10): 10I133, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30399665

RESUMEN

A large area solid radiochemistry collector was deployed at the National Ignition Facility (NIF) with a collection efficiency for post-shot, solid target debris of approximately 1% of the total 4π solid angle. The collector consisted of a 20-cm diameter vanadium foil surrounded by an aluminum side-enclosure and was fielded 50 cm from the NIF target. The collector was used on two NIF neutron yield shots, both of which had a monolayer of 238U embedded in the capsule ablator 10 µm from the inner surface. Fission and activation products produced in the 238U were collected, and subsequent analyses via gamma spectroscopy indicated that the distribution of fission products was not uniform, with peak and valley fission products preferentially collected on the vanadium and low- and high-mass fission products primarily located on the aluminum side-enclosure. The results from these shots will be used to design future nuclear data experiments at NIF.

7.
J Radioanal Nucl Chem ; 315(2): 409-416, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29497227

RESUMEN

Low enriched uranium samples of unknown origin were analyzed by 16 laboratories in the context of a Collaborative Materials Exercise (CMX), organized by the Nuclear Forensics International Technical Working Group (ITWG). The purpose was to compare and prioritize nuclear forensic methods and techniques, and to evaluate attribution capabilities among participants. This paper gives a snapshot of the gamma spectrometric capabilities of the participating laboratories and summarizes the results achieved by gamma spectrometry.

8.
Rev Sci Instrum ; 87(11): 11D813, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27910632

RESUMEN

The solid debris collection capability at the National Ignition Facility has been expanded to include a third line-of-sight assembly. The solid radiochemistry nuclear diagnostic measurement of the ratio of gold isotopes is dependent on the efficient collection of neutron-activated hohlraum debris by passive metal disks. The collection of target debris at this new location is more reliable in comparison to the historic locations, and it appears to be independent of collector surface ablation.

9.
J Evol Biol ; 29(10): 2054-2069, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27369460

RESUMEN

It is widely accepted that insular terrestrial biodiversity progresses with island age because colonization and diversification proceed over time. Here, we assessed whether this principle extends to oceanic island streams. We examined rangewide mtDNA sequence variation in four stream-dwelling species across the Hawaiian archipelago to characterize the relationship between colonization and demographic expansion, and to determine whether either factor reflects island age. We found that colonization and demographic expansion are not related and that neither corresponds to island age. The snail Neritina granosa exhibited the oldest colonization time (~2.713 mya) and time since demographic expansion (~282 kya), likely reflecting a preference for lotic habitats most prevalent on young islands. Conversely, gobioid fishes (Awaous stamineus, Eleotris sandwicensis and Sicyopterus stimpsoni) colonized the archipelago only ~0.411-0.935 mya, suggesting ecological opportunities for colonization in this group were temporally constrained. These findings indicate that stream communities form across colonization windows, underscoring the importance of ecological opportunities in shaping island freshwater diversity.


Asunto(s)
Organismos Acuáticos , Biodiversidad , Animales , Agua Dulce , Hawaii , Perciformes , Dinámica Poblacional , Caracoles
10.
Appl Radiat Isot ; 107: 199-202, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26524406

RESUMEN

A high-purity carrier-free (7)Be was efficiently isolated following proton bombardment of a lithium hydroxide-aluminum target. The separation of beryllium from lithium and aluminum was achieved through a hydrochloric acid elution system utilizing cation exchange chromatography. The beryllium recovery, +99%, was assessed through gamma spectroscopy while the chemical purity was established by mass spectrometry. The decontamination factors of beryllium from lithium and aluminum were determined to be 6900 and 300, respectively.

11.
Rev Sci Instrum ; 86(7): 076105, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26233419

RESUMEN

A new radiochemical method for determining deuterium-tritium (DT) fuel and plastic ablator (CH) areal densities (ρR) in high-convergence, cryogenic inertial confinement fusion implosions at the National Ignition Facility is described. It is based on measuring the (198)Au/(196)Au activation ratio using the collected post-shot debris of the Au hohlraum. The Au ratio combined with the independently measured neutron down scatter ratio uniquely determines the areal densities ρR(DT) and ρR(CH) during burn in the context of a simple 1-dimensional capsule model. The results show larger than expected ρR(CH) values, hinting at the presence of cold fuel-ablator mix.

12.
Mol Ecol ; 24(3): 545-63, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25442423

RESUMEN

Environmental heterogeneity can promote the emergence of locally adapted phenotypes among subpopulations of a species, whereas gene flow can result in phenotypic and genotypic homogenization. For organisms like amphidromous fishes that change habitats during their life history, the balance between selection and migration can shift through ontogeny, making the likelihood of local adaptation difficult to predict. In Hawaiian waterfall-climbing gobies, it has been hypothesized that larval mixing during oceanic dispersal counters local adaptation to contrasting topographic features of streams, like slope gradient, that can select for predator avoidance or climbing ability in juvenile recruits. To test this hypothesis, we used morphological traits and neutral genetic markers to compare phenotypic and genotypic distributions in recruiting juveniles and adult subpopulations of the waterfall-climbing amphidromous goby, Sicyopterus stimpsoni, from the islands of Hawai'i and Kaua'i. We found that body shape is significantly different between adult subpopulations from streams with contrasting slopes and that trait divergence in recruiting juveniles tracked stream topography more so than morphological measures of adult subpopulation differentiation. Although no evidence of population genetic differentiation was observed among adult subpopulations, we observed low but significant levels of spatially and temporally variable genetic differentiation among juvenile cohorts, which correlated with morphological divergence. Such a pattern of genetic differentiation is consistent with chaotic genetic patchiness arising from variable sources of recruits to different streams. Thus, at least in S. stimpsoni, the combination of variation in settlement cohorts in space and time coupled with strong postsettlement selection on juveniles as they migrate upstream to adult habitats provides the opportunity for morphological adaptation to local stream environments despite high gene flow.


Asunto(s)
Adaptación Fisiológica/genética , Flujo Génico , Perciformes/genética , Animales , Ecosistema , Variación Genética , Genotipo , Hawaii , Perciformes/anatomía & histología , Fenotipo
13.
J Evol Biol ; 28(2): 503-9, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25522811

RESUMEN

Parental care benefits offspring through maternal effects influencing their development, growth and survival. However, although parental care in general is likely the result of adaptive evolution, it does not follow that specific differences in the maternal effects that arise from care are also adaptive. Here, we used an interspecific cross-fostering design in the burying beetle species Nicrophorus orbicollis and N. vespilloides, both of which have elaborate parental care involving direct feeding of regurgitated food to offspring, to test whether maternal effects are optimized within a species and therefore adaptive. Using a full-factorial design, we first demonstrated that N. orbicollis care for offspring longer regardless of recipient species. We then examined offspring development and mass in offspring reared by hetero- or conspecific parents. As expected, there were species-specific direct effects independent of the maternal effects, as N. orbicollis larvae were larger and took longer to develop than N. vespilloides regardless of caregiver. We also found significant differences in maternal effects: N. vespilloides maternal care caused more rapid development of offspring of either species. Contrary to expectations if maternal effects were species-specific, there were no significant interactions between caretaker and recipient species for either development time or mass, suggesting that these maternal effects are general rather than optimized within species. We suggest that rather than coadaptation between parents and offspring performance, the species differences in maternal effects may be correlated with direct effects, and that their evolution is driven by selection on those direct effects.


Asunto(s)
Adaptación Fisiológica/genética , Escarabajos/fisiología , Conducta Materna/fisiología , Animales , Escarabajos/genética , Femenino , Masculino , Especificidad de la Especie
14.
Rev Sci Instrum ; 85(6): 063508, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24985820

RESUMEN

We describe a radiochemical measurement of the ratio of isotope concentrations produced in a gold hohlraum surrounding an Inertial Confinement Fusion capsule at the National Ignition Facility (NIF). We relate the ratio of the concentrations of (n,γ) and (n,2n) products in the gold hohlraum matrix to the down-scatter of neutrons in the compressed fuel and, consequently, to the fuel's areal density. The observed ratio of the concentrations of (198m+g)Au and (196g)Au is a performance signature of ablator areal density and the fuel assembly confinement time. We identify the measurement of nuclear cross sections of astrophysical importance as a potential application of the neutrons generated at the NIF.

15.
Phys Rev Lett ; 109(16): 162501, 2012 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-23215070

RESUMEN

Two years after the discovery of element 117, we undertook a second campaign using the (249)Bk+(48)Ca reaction for further investigations of the production and decay properties of the isotopes of element 117 on a larger number of events. The experiments were started in the end of April 2012 and are still under way. This Letter presents the results obtained in 1200 hours of an experimental run with the beam dose of (48)Ca of about 1.5×10(19) particles. The (249)Bk target was irradiated at two energies of (48)Ca that correspond to the maximum probability of the reaction channels with evaporation of three and four neutrons from the excited (297)117. In this experiment, two decay chains of (294)117 (3n) and five decay chains of (293)117 (4n) were detected. In the course of the long-term work, (249)Cf-the product of decay of (249)Bk (330 d)-is being accumulated in the target. Consequently, in the present experiment, we also detected a single decay of the known isotope (294)118 that was produced during 2002-2005 in the reaction (249)Cf((48)Ca,3n)(294)118. The obtained results are compared with the data from previous experiments. The experiments are carried out in the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, using the heavy-ion cyclotron U400.

16.
Rev Sci Instrum ; 83(10): 10D904, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23126908

RESUMEN

Radiochemical analysis of post-ignition debris inside the National Ignition Facility (NIF) target chamber can help determine various diagnostic parameters associated with the implosion efficiency of the fusion capsule. This technique is limited by the ability to distinguish ablator material from other debris and by the collection efficiency of the capsule debris after implosion. Prior to designing an on-line collection system, the chemical nature and distribution of the debris inside the chamber must be determined. The focus of our current work has been on evaluating capture of activated Au hohlraum debris on passive foils (5 cm diameter, 50 cm from target center) post-shot. Preliminary data suggest that debris distribution is locally heterogeneous along the equatorial and polar line-of-sights.

17.
Rev Sci Instrum ; 83(10): 10D917, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23126919

RESUMEN

The Radiochemical Analysis of Gaseous Samples (RAGS) diagnostic apparatus was recently installed at the National Ignition Facility (NIF). Following a NIF shot, RAGS is used to pump the gas load from the NIF chamber for purification and isolation of the noble gases. After collection, the activated gaseous species are counted via gamma spectroscopy for measurement of the capsule areal density and fuel-ablator mix. Collection efficiency was determined by injecting a known amount of (135)Xe into the NIF chamber, which was then collected with RAGS. Commissioning was performed with an exploding pusher capsule filled with isotopically enriched (124)Xe and (126)Xe added to the DT gas fill. Activated xenon species were recovered post-shot and counted via gamma spectroscopy. Results from the collection and commissioning tests are presented. The performance of RAGS allows us to establish a noble gas collection method for measurement of noble gas species produced via neutron and charged particle reactions in a NIF capsule.

18.
J Fish Biol ; 81(2): 903-20, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22803741

RESUMEN

A series of waterfall-climbing trials were conducted to identify cues that direct the climbing of juvenile Sicyopterus stimpsoni. In the first experiment, whether climbing juveniles preferentially ascend water sources with conspecifics or whether the presence of just stream water is sufficient to attract fish to ascend a climbing path were assessed. In the second experiment, whether climbing juveniles create a trail of mucus that facilitates the ability of conspecifics to follow their lead was determined. The results indicate that juvenile S. stimpsoni are less likely to climb in waters devoid of organic cues but are strongly attracted to stream water with or without the odour of conspecifics. Once climbing, performance did not differ for juveniles climbing in differing water choices, suggesting an all-or-nothing commitment once climbing commences. Climbing S. stimpsoni did produce a mucous trail while climbing that was associated with a mucous gland that dramatically increases in size just prior to juveniles gaining the ability to climb. The trail was not followed closely by subsequent juveniles traversing the same channel, however, suggesting only weak trail-following in waterfall climbing S. stimpsoni. Previous genetic studies suggest that juvenile S. stimpsoni do not home to natal streams in the face of strong near-shore oceanic currents. Instead, these fish appear primarily to rely on cues that suggest the presence of organic growth in streams, a factor that may indicate suitable habitat in an ever-changing stream environment but which may also be vulnerable to interference through human activity.


Asunto(s)
Migración Animal , Señales (Psicología) , Perciformes/fisiología , Animales , Hawaii , Odorantes , Ríos
19.
Gait Posture ; 36(3): 449-53, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22609042

RESUMEN

The Nintendo Wii Fit™ may provide an affordable alternative to traditional biofeedback or virtual reality systems for retraining or improving motor function in populations with impaired balance. The purpose of this study was to evaluate postural control strategies healthy individuals use to play Wii Fit™ videogames. Sixteen young adults played 10 trials of Ski Slalom and Soccer Heading respectively. Centre of pressure (COP) excursion and three-dimensional movement data were acquired to determine variability in medial-lateral COP sway and shoulder-pelvic movement. While there was no difference in medial-lateral COP variability between games during trial 1, there was a significant difference after 10 trials. COP sway increased (59-75 mm) for Soccer Heading while it decreased (67-33 mm) for Ski Slalom from trial 1 to trial 10. During Ski Slalom participants demonstrated decreased shoulder and pelvic movement combined with increased pelvic-shoulder coupling. Conversely, participants demonstrated greater initial shoulder tilt when playing Soccer Heading, with no reduction in pelvic rotation and tilt. Participants decreased pelvic and trunk movements when skiing, suggesting a greater contribution of lower extremity control while they primarily used a trunk strategy to play Soccer Heading.


Asunto(s)
Equilibrio Postural/fisiología , Rango del Movimiento Articular/fisiología , Interfaz Usuario-Computador , Juegos de Video , Adulto , Biorretroalimentación Psicológica , Estudios de Cohortes , Estudios de Evaluación como Asunto , Femenino , Articulación de la Cadera/fisiología , Humanos , Masculino , Postura/fisiología , Articulación del Hombro/fisiología , Esquí/fisiología , Fútbol/fisiología , Adulto Joven
20.
Phys Rev Lett ; 108(2): 022502, 2012 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-22324675

RESUMEN

Results of a new series of experiments on the study of production cross sections and decay properties of the isotopes of element 115 in the reaction (243)Am+(48)Ca are presented. Twenty-one new decay chains originating from (288)115 were established as the product of the 3n-evaporation channel by measuring the excitation function at three excitation energies of the compound nucleus (291)115. The decay properties of all newly observed nuclei are in full agreement with those we measured in 2003. At the lowest excitation energy E*=33 MeV, for the first time we registered the product of the 2n-evaporation channel, (289)115, which was also observed previously in the reaction (249)Bk+(48)Ca as the daughter nucleus of the decay of (293)117. The maximum cross section for the production of (288)115 is found to be 8.5 pb at E*≈36 MeV.

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