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1.
Nurse Educ Pract ; 76: 103929, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38461591

RESUMEN

AIM: The aim of this study was to undertake an in-depth exploration of the lived experiences of in-hospital, non-intensive care, ward-based nurses' experiences of real-life CPR events. BACKGROUND: There is growing evidence suggesting that may nurses not be able to successfully perform in a cardiac arrest situation. Reasons include a lack of clear leadership at the arrest, performance anxiety, role confusion and knowledge and skill degradation over time. METHODS: In-depth semi-structured interviews were conducted with fifteen ward-based hospital nurses from three hospitals. Interviews were recorded, transcribed verbatim and inductive thematic analysis was completed using NVivo 12 software. FINDINGS: Four main themes emerged from data. The main themes are: (1) Not Being able to Perform When it Matters, (2) Working Really Well as a Team, (3) Reflecting on the Experience: The Good, the Bad & the Ugly and (4) Learning to get it Right for Next Time CONCLUSION: Performing BLS is a stressful and anxiety-provoking experience for ward-based nurses. Anxiety levels appear to decrease slightly only when nurses have had at least one previous real-life experience with resuscitation. Current BLS education does not prepare nurses for the complexities of resuscitation. Future BLS education should focus on in-depth scenarios, including interdisciplinary team training and with greater frequency than the current yearly mandatory sessions. Listening to the lived experiences of nurses who have performed BLS has given much needed insight into approaches that educators can use to improve BLS education delivery.


Asunto(s)
Reanimación Cardiopulmonar , Enfermeras y Enfermeros , Humanos , Reanimación Cardiopulmonar/educación , Competencia Clínica , Aprendizaje , Hospitales
2.
Animal ; 17(12): 101009, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37952301

RESUMEN

The only common European Union (EU) legislation set up specifically to ensure the welfare of dairy cattle is for calves. As a consequence, there is wide diversity in how dairy cattle welfare is ensured in EU countries. A few countries have legal requirements for dairy cattle welfare, while in others, it is left to industry standards or niche production requirements, typically linked to various premium labels. In this paper, we compared animal welfare provisions in dairy cattle production across five countries with different combinations of legislative and other approaches: Denmark, Germany, the Netherlands, Sweden, and the United Kingdom. Firstly, we aimed to map the diversity of animal welfare initiatives. Secondly, we used the Benchmark method of expert valuations and weightings of the relative importance of individual welfare provisions. We found that Denmark and Sweden have the highest level of dairy cattle welfare provisions as measured by the Benchmark method, partly due to high legislative welfare requirements, followed by the United Kingdom, which has an extensive industry standard with very high uptake. Germany and the Netherlands, on the other hand, have lower levels of documented welfare provisions, and correspondingly a Benchmark score closer to a baseline defined by legal requirements at EU level. We also found differences in what elements of animal welfare were focussed on. Some initiatives emphasised fulfilling the social needs of cattle, while others focused more on space and freedom to move. Also, the countries with the highest Benchmark score had a relatively high level of production of organic and other specialty dairy products. We found the effect of national legislation or ambitious industry standards on dairy cattle welfare to be much larger than previous studies have found in either pigs or poultry. At a time when the EU is considering stepping up its efforts to improve animal welfare in terms of common minimum standards, the results of this study could have important policy implications. The diversity in the level of dairy cattle welfare standards found across countries may speak in favour of having shared minimum standards, both at EU level and globally. However, even among countries with a similar Benchmark score, we found a difference in the kinds of welfare provisions at work, which may make full harmonisation of standards more challenging.


Asunto(s)
Productos Lácteos , Industria Lechera , Animales , Bovinos , Porcinos , Industria Lechera/métodos , Europa (Continente) , Países Bajos , Unión Europea , Bienestar del Animal
3.
Int J Obstet Anesth ; 56: 103931, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37801899

RESUMEN

European countries of "Eastern Block" origin took different healthcare and economic development trajectories after the Berlin Wall fell. Despite decreased maternal and neonatal mortality in the last two decades, healthcare disparities exist between the various countries. Minimum standards for obstetric anesthesia are not available for every maternity patient. Lack of equity in access to healthcare for maternity patients is multifactorial and includes differences in systems of care and health economics, and shortages of medical personnel. The war in Ukraine generates additional challenges for healthcare systems in the region, resulting from a significant increase in the number of refugees, some of whom are pregnant and require maternity services, including obstetric anesthesia and analgesia and maternal critical care. The next decade's challenges comprise the implementation of evidence-based medicine advances in the field of obstetric anesthesia and analgesia, and of maternal critical care at national levels, including access to neuraxial opioids, the broad implementation of enhanced recovery after cesarean section protocols, and more frequent use of labor epidural analgesia. Further, there needs to be improvement in medical education provided in the national language, so that healthcare providers, patients, and their families can build and provide a safe environment for maternity patients. In addition, better provision of services and access to healthcare providers who have been well trained and are dedicated to dealing with obstetric patients. These measures will hopefully enhance the quality of care for maternity patients, focusing on further reduction of maternal and neonatal morbidity and mortality, which is a priority and a highly desirable long-term outcome.


Asunto(s)
Analgesia Epidural , Anestesiología , Trabajo de Parto , Servicios de Salud Materna , Recién Nacido , Embarazo , Femenino , Humanos , Cesárea , Dolor
4.
J Phys Chem A ; 127(36): 7618-7629, 2023 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-37647609

RESUMEN

A new aluminum-bearing species, OAlNO, which has the potential to impact the chemistry of the Earth's upper atmosphere, is characterized via high-level, ab initio, spectroscopic methods. Meteor-ablated aluminum atoms are quickly oxidized to aluminum oxide (AlO) in the mesosphere and lower thermosphere (MLT), where a steady-state layer of AlO then builds up. Concurrent formation of nitric oxide (NO) in the same region of the atmosphere will lead to the bimolecular formation of the OAlNO molecule. Molecular orbital analysis provides fundamental insights into the chemical bonding and energetic arrangement of the triplet (1 3A″) ground state and singlet (1 1A') excited-state species of OAlNO. Additionally, unpaired electrons on the terminal oxygen atom of triplet (1 3A″) OAlNO cause it to be reactive to atmospheric species, potentially impacting climate science and high-altitude chemistry. The triplet (1 3A″) ground-state species exhibits a large permanent dipole moment useful for rotational spectroscopic detection; however, similar rotational constants to the singlet (1 1A') excited-state species will hamper differentiation in a spectrum. Strong infrared intensities will assist in detection and discrimination of the different spin states and isomers. Repulsive electronic excited states of OAlNO will lead to photolysis of the Al-N bond and formation of various electronic states of AlO + NO through nonadiabatic pathways. Reaction through the OAlNO intermediate represents a means for the production of electronically excited AlO, leading to new chemistry in the atmosphere. Excitation to higher-lying electronic states will lead to fluorescence with a minor Stokes shift, useful for laboratory investigation. Such physical properties of this molecule will allow for new, unexplored chemical pathways in the MLT to be considered.

5.
IUCrJ ; 10(Pt 5): 579-583, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37493524

RESUMEN

The great success of single-particle electron cryo-microscopy (cryoEM) during the last decade has involved the development of powerful new computer programs and packages that guide the user along a recommended processing workflow, in which the wisdom and choices made by the developers help everyone, especially new users, to obtain excellent results. The ability to carry out novel, non-standard or unusual combinations of image-processing steps is sometimes compromised by the convenience of a standard procedure. Some of the older programs were written with great flexibility and are still very valuable. Among these, the original MRC image-processing programs for structure determination by 2D crystal and helical processing alongside general-purpose utility programs such as Ximdisp, label, imedit and twofile are still available. This work describes an updated version of the MRC software package (MRC2020) that is freely available from CCP-EM. It includes new features and improvements such as extensions to the MRC format that retain the versatility of the package and make it particularly useful for testing novel computational procedures in cryoEM.

6.
Phytopathology ; 113(4): 694-706, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37137816

RESUMEN

Plant disease management has not significantly changed in the past 50 years, even as great strides have been made in the understanding of fungal biology and the etiology of plant disease. Issues of climate change, supply chain failures, war, political instability, and exotic invasives have created even more serious implications for world food and fiber security, and the stability of managed ecosystems, underscoring the urgency for reducing plant disease-related losses. Fungicides serve as the primary example of successful, widespread technology transfer, playing a central role in crop protection, reducing losses to both yield and postharvest spoilage. The crop protection industry has continued to improve upon previous fungicide chemistries, replacing active ingredients lost to resistance and newly understood environmental and human health risks, under an increasingly stricter regulatory environment. Despite decades of advances, plant disease management continues to be a constant challenge that will require an integrated approach, and fungicides will continue to be an essential part of this effort.


Asunto(s)
Fungicidas Industriales , Humanos , Fungicidas Industriales/farmacología , Ecosistema , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología
7.
J Environ Manage ; 340: 117995, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37100004

RESUMEN

Invasive alien species threaten biodiversity with domestic gardens acting as a major pathway for the introduction of alien species. Even though the Nordic region is not currently a hotspot for biological invasions, the number of invasions in the Nordic area has been predicted to increase due to climate change. Given a time lag between introduction and invasion, many non-invasive horticultural alien species already introduced into gardens may become invasive in the future. This study aimed to identify the communication needs of Swedish garden owners regarding their management of invasive alien species. A survey among domestic garden owners, informed by topic specialists and local area experts, and interviews with garden owners were conducted in three different bio-climatic areas in a latitudinal gradient across Sweden. The questions targeted invasive alien species and their relations to biodiversity loss and climate change, as well as measures taken to control these species. Analysing the survey data collected in relation to measures taken to control invasive species, Bayesian Additive Regression Tree (BART) modelling was used to identify geographically varying communication needs of the domestic garden owners. In all study areas, the garden owners' measures taken to control invasive alien species were correlated with their strength of beliefs in having experienced local biodiversity loss. A majority of the garden owners were, moreover, uncertain about the impact of climate change on the invasiveness of alien species. In addition, the garden owners' capacity for identifying invasive alien species was often in need of improvement, in particular with respect to the species Impatiens glandulifera, Reynoutria japonica and Rosa rugosa. The results suggest that the evidence-based guidelines for effective communications we developed, have the potential to help communicators meet the local communication needs of garden owners across Sweden, in relation to the management of invasive alien garden species.


Asunto(s)
Jardines , Especies Introducidas , Suecia , Teorema de Bayes , Biodiversidad , Comunicación , Ecosistema
8.
Front Bioeng Biotechnol ; 9: 676894, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34268296

RESUMEN

Take-off is a critical phase of flight, and many birds jump to take to the air. Although the actuation of the hindlimb in terrestrial birds is not limited to the sagittal plane, and considerable non-sagittal plane motion has been observed during take-off jumps, how the spatial arrangement of hindlimb muscles in flying birds facilitates such jumps has received little attention. This study aims to ascertain the 3D hip muscle function in the magpie (Pica pica), a bird known to jump to take-off. A musculoskeletal model of the magpie hindlimb was developed using µCT scans (isotropic resolution of 18.2 µm) to derive bone surfaces, while the 3D muscle path definition was further informed by the literature. Function was robustly characterized by determining the 3D moment-generating capacity of 14 hip muscles over the functional joint range of motion during a take-off leap considering variations across the attachment areas and uncertainty in dynamic muscle geometry. Ratios of peak flexion-extension (FE) to internal-external rotation (IER) and abduction-adduction (ABD) moment-generating capacity were indicators of muscle function. Analyses of 972 variations of the 3D muscle paths showed that 11 of 14 muscles can act as either flexor or extensor, while all 14 muscles demonstrated the capacity to act as internal or external rotators of the hip with the mean ratios of peak FE to IER and ABD moment-generating capacity were 0.89 and 0.31, respectively. Moment-generating capacity in IER approaching levels in the FE moment-generating capacity determined here underline that the avian hip muscle function is not limited to the sagittal plane. Together with previous findings on the 3D nature of hindlimb kinematics, our results suggest that musculoskeletal models to develop a more detailed understanding of how birds orchestrate the use of muscles during a take-off jump cannot be restricted to the sagittal plane.

9.
Cereb Cortex ; 31(8): 3856-3871, 2021 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-33825852

RESUMEN

Cognitive performance in children is predictive of academic and social outcomes; therefore, understanding neurobiological mechanisms underlying individual differences in cognition during development may be important for improving quality of life. The belief that a single, psychological construct underlies many cognitive processes is pervasive throughout society. However, it is unclear if there is a consistent neural substrate underlying many cognitive processes. Here, we show that a distributed configuration of cortical surface area and apparent thickness, when controlling for global imaging measures, is differentially associated with cognitive performance on different types of tasks in a large sample (N = 10 145) of 9-11-year-old children from the Adolescent Brain and Cognitive DevelopmentSM (ABCD) study. The minimal overlap in these regionalization patterns of association has implications for competing theories about developing intellectual functions. Surprisingly, not controlling for sociodemographic factors increased the similarity between these regionalization patterns. This highlights the importance of understanding the shared variance between sociodemographic factors, cognition and brain structure, particularly with a population-based sample such as ABCD.


Asunto(s)
Corteza Cerebral/anatomía & histología , Corteza Cerebral/fisiología , Cognición/fisiología , Adolescente , Desarrollo del Adolescente , Niño , Femenino , Humanos , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Desempeño Psicomotor/fisiología , Sensibilidad y Especificidad , Factores Sociodemográficos
11.
Rev Sci Instrum ; 92(1): 013101, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33514249

RESUMEN

We introduce a setup to measure high-resolution inelastic x-ray scattering at the High Energy Density scientific instrument at the European X-Ray Free-Electron Laser (XFEL). The setup uses the Si (533) reflection in a channel-cut monochromator and three spherical diced analyzer crystals in near-backscattering geometry to reach a high spectral resolution. An energy resolution of 44 meV is demonstrated for the experimental setup, close to the theoretically achievable minimum resolution. The analyzer crystals and detector are mounted on a curved-rail system, allowing quick and reliable changes in scattering angle without breaking vacuum. The entire setup is designed for operation at 10 Hz, the same repetition rate as the high-power lasers available at the instrument and the fundamental repetition rate of the European XFEL. Among other measurements, it is envisioned that this setup will allow studies of the dynamics of highly transient laser generated states of matter.

12.
AJNR Am J Neuroradiol ; 41(11): 2075-2081, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32883666

RESUMEN

Primary central nervous system vasculitis (PCNSV) is a poorly understood neuroinflammatory disease of the CNS affecting the intracranial vasculature. Although PCNSV classically manifests as a multifocal beaded narrowing of the intracranial vessels, some patients may not have angiographic abnormalities. A rare subset of patients with PCNSV present with masslike brain lesions mimicking a neoplasm. In this article, we retrospectively review 10 biopsy-confirmed cases of tumefactive PCNSV (t-PCNSV). All cases of t-PCNSV in our series that underwent CTA or MRA were found to have normal large and medium-sized vessels. T-PCNSV had a variable MR imaging appearance with most cases showing cortical/subcortical enhancing masslike lesion (70%), often with microhemorrhages (80%). Diffusion restriction was absent in all lesions. In summary, normal vascular imaging does not exclude the diagnosis of t-PCNSV. Advanced imaging techniques including MR perfusion and MR spectroscopy failed to demonstrate specific findings for t-PCNSV but assisted in excluding neoplasm in the differential diagnosis. Biopsy remains mandatory for definitive diagnosis.


Asunto(s)
Neuroimagen/métodos , Vasculitis del Sistema Nervioso Central/diagnóstico por imagen , Vasculitis del Sistema Nervioso Central/patología , Adolescente , Adulto , Anciano , Neoplasias Encefálicas/diagnóstico , Diagnóstico Diferencial , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
13.
Sci Rep ; 10(1): 14564, 2020 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-32884061

RESUMEN

We present a method to determine the bulk temperature of a single crystal diamond sample at an X-Ray free electron laser using inelastic X-ray scattering. The experiment was performed at the high energy density instrument at the European XFEL GmbH, Germany. The technique, based on inelastic X-ray scattering and the principle of detailed balance, was demonstrated to give accurate temperature measurements, within [Formula: see text] for both room temperature diamond and heated diamond to 500 K. Here, the temperature was increased in a controlled way using a resistive heater to test theoretical predictions of the scaling of the signal with temperature. The method was tested by validating the energy of the phonon modes with previous measurements made at room temperature using inelastic X-ray scattering and neutron scattering techniques. This technique could be used to determine the bulk temperature in transient systems with a temporal resolution of 50 fs and for which accurate measurements of thermodynamic properties are vital to build accurate equation of state and transport models.

14.
Rhinology ; 58(4): 323-332, 2020 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-32175530

RESUMEN

BACKGROUND: Recent literature suggests that concurrent septoplasty during endoscopic sinus surgery (ESS) improves patient outcomes, however, the underlying indications for performing concurrent septoplasty are unknown. The objective of this study was to investigate the relationship between objective radiologic measures of nasal septal deviation with preoperative patient symptomatology and measures of CRS disease severity. We also sought to understand the association of objective radiologic measurements with surgeon performance of concurrent septoplasty during ESS. METHODOLOGY: Seventy-four patients with CRS undergoing ESS were prospectively enrolled. Angles of septal deviation, intranasal areas and volumes were assessed on preoperative computed tomography (CT) scans and correlated with a robust battery of patient reported outcomes measures (PROMs), objective measures of CRS severity including olfaction scores, radiologic and endoscopic staging, and performance of septoplasty. RESULTS: Intranasal areas and volumes demonstrated only weak linear associations with patient-reported nasal congestion, however, angles of septal deviation alone did not correlate with congestion or any other PROM measure. Meanwhile, radiologic septal-related measurements did not correlate with objective measures of CRS disease severity or the performance of a concurrent septoplasty. CONCLUSIONS: Though prior studies demonstrate improved patient outcomes in the setting of concurrent septoplasty during ESS, this study failed to establish an association between preoperative radiologic septal-related measurements and patient symptomatology or surgeon decision to perform septoplasty. Although objective factors to identify patients most likely to benefit from concurrent septoplasty remain unidentified, the potential improvement of surgical recommendations and patient outcomes makes this an important area of continued investigation.


Asunto(s)
Obstrucción Nasal , Tabique Nasal , Rinoplastia , Endoscopía , Femenino , Humanos , Masculino , Obstrucción Nasal/cirugía , Tabique Nasal/anatomía & histología , Resultado del Tratamiento
16.
Phys Rev Lett ; 122(3): 034801, 2019 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-30735413

RESUMEN

A tunable plasma-based energy dechirper has been developed at FLASHForward to remove the correlated energy spread of a 681 MeV electron bunch. Through the interaction of the bunch with wakefields excited in plasma the projected energy spread was reduced from a FWHM of 1.31% to 0.33% without reducing the stability of the incoming beam. The experimental results for variable plasma density are in good agreement with analytic predictions and three-dimensional simulations. The proof-of-principle dechirping strength of 1.8 GeV/mm/m significantly exceeds those demonstrated for competing state-of-the-art techniques and may be key to future plasma wakefield-based free-electron lasers and high energy physics facilities, where large intrinsic chirps need to be removed.

17.
Int J Obstet Anesth ; 37: 118-121, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30660373

RESUMEN

Epidural hematoma is a very uncommon complication of spinal anesthesia. Its incidence has been reported to be between 1:200 000-250 000 in the obstetric population following neuraxial anesthesia. Cesarean delivery increases the risk of maternal venous thromboembolism significantly and recommendations to decrease its incidence and morbidity have been developed. Strategies to decrease venous thromboembolism include pharmacologic prophylaxis with unfractionated or low molecular weight heparin. We report a case of spinal-epidural hematoma occurring in a parturient who received spinal anesthesia for a planned, repeat cesarean delivery after low molecular weight heparin thromboprophylaxis.


Asunto(s)
Anestesia Obstétrica/efectos adversos , Anestesia Raquidea/efectos adversos , Anticoagulantes/uso terapéutico , Cesárea/efectos adversos , Hematoma Espinal Epidural/etiología , Heparina de Bajo-Peso-Molecular/uso terapéutico , Tromboembolia Venosa/prevención & control , Adulto , Femenino , Humanos
18.
Theriogenology ; 126: 128-139, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30551019

RESUMEN

To better understand uterine inflammation in postpartum dairy cows we collected sequential cytobrush samples at 29-35 and at 49-55 d in milk (DIM). Based on the uterine cytology, cows were classified as Non-endometritic (n = 23; <18% neutrophils) or Endometritic (n = 12; ≥18% neutrophils) at 29-35 DIM and Non-endometritic (n = 17; <10% neutrophils) or Endometritic (n = 9; ≥10% neutrophils) at 49-55 DIM. Cows defined as Sham Controls (n = 6) were examined by vaginoscopy at 29-35 DIM and identified as Non-endometritic (<10% neutrophils) at 49-55 DIM. Cytokine gene expression in cytobrush samples was assessed using qRT-PCR. Sham Controls did not differ significantly (P > 0.17) from Non-endometritic cows at 49-55 DIM and these data were combined (n = 23). Uterine cytology-based classification using the aforementioned thresholds effectively separated cows into groups with Endometritic cows having significantly higher expression of pro-inflammatory (interleukin (IL)-1α, IL-1ß, IL-6, IL-8, IL-17A CSF-1; P < 0.01) and regulatory (IL-1RA and IL-10; P < 0.03) cytokines, relative to Non-endometritic cows. Furthermore, Non-endometritic cows showed a significant decline (P < 0.03) in the expression of pro-inflammatory (IL-1α, IL-6, IL-8) and regulatory (IL-10) cytokine genes as the postpartum period progressed; whereas Endometritic cows exhibited a sustained elevation in transcript abundance throughout the sample period for both pro-inflammatory and regulatory cytokine genes. Expression of transforming growth factor (TGF) genes was more complex with TGF-ß3 expression significantly (P < 0.01) lower at 29-35 DIM and TGF-ß1 gene expression significantly (P < 0.03) increased at 49-55 DIM in Endometritic versus Non-endometritic cows. Expression of TGF-ß2 gene was 2.7-fold higher (P < 0.01) at 29-35 DIM in cows that remained Endometritic when compared to cows recovering by 49-55 DIM. Some Non-endometritic cows (n = 4) at 29-35 DIM were reclassified as Endometritic at 49-55 DIM. The sampling procedures at 29-35 DIM did not alter either the cellular response (P > 0.43) or cytokine gene expression (P > 0.17) at 49-55 DIM. In conclusion, normal uterine involution is characterized by a progressive decline in pro-inflammatory and regulatory cytokine gene expression, while cows with endometritis show a dysregulated inflammatory process characterized by a sustained elevation in pro-inflammatory and regulatory cytokine gene expression. This analysis also shows that decreased TGF-ß2 gene expression at 29-35 DIM may be an indicator of recovery from endometritis.


Asunto(s)
Enfermedades de los Bovinos/inmunología , Citocinas/metabolismo , Endometritis/veterinaria , Útero/metabolismo , Animales , Bovinos , Enfermedades de los Bovinos/metabolismo , Citocinas/genética , Endometritis/inmunología , Endometritis/metabolismo , Femenino , Regulación de la Expresión Génica , Periodo Posparto/inmunología , Periodo Posparto/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Útero/patología
19.
Mol Neurobiol ; 56(6): 4023-4036, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30259399

RESUMEN

Amyloid-ß 42 [Aß1-42 (Aß42)] is one of the main Aß peptide isoforms found in amyloid plaques of brains with Alzheimer's disease (AD). Although Aß42 is associated with neurotoxicity, it might mediate several normal physiological processes during embryonic brain development and in the adult brain. However, due to the controversy that exists in the field, relatively little is known about its physiological function. In the present work, we have analyzed the effects of different concentrations of monomeric Aß42 on cell death, proliferation, and cell fate specification of human neural stem cells (hNSCs), specifically the hNS1 cell line, undergoing differentiation. Our results demonstrate that at higher concentrations (1 µM), Aß42 increases apoptotic cell death and DNA damage, indicating that prolonged exposure of hNS1 cells to higher concentrations of Aß42 is neurotoxic. However, at lower concentrations, Aß42 significantly promotes cell proliferation and glial cell specification of hNS1 cells by increasing the pool of proliferating glial precursors, without affecting neuronal differentiation, in a concentration-dependent manner. At the molecular level, these effects could be mediated, at least in part, by GSK3ß, whose expression is increased by treatment with Aß42 and whose inhibition prevents the glial specification induced by Aß42. Since the cellular and molecular effects are known to appear decades before the first clinical symptoms, these types of studies are important in discovering the underlying pathophysiological processes involved in the development of AD. This knowledge could then be used in diagnosing the disease at early stages and be applied to the development of new treatment options.


Asunto(s)
Péptidos beta-Amiloides/toxicidad , Células-Madre Neurales/patología , Neurogénesis/efectos de los fármacos , Neuroglía/patología , Fragmentos de Péptidos/toxicidad , Apoptosis/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular , Linaje de la Célula/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Humanos , Células-Madre Neurales/efectos de los fármacos , Neuroglía/efectos de los fármacos , Piridinas/farmacología , Pirimidinas/farmacología , Transducción de Señal/efectos de los fármacos
20.
J Phys Chem A ; 122(35): 7079-7088, 2018 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-30095913

RESUMEN

Magnesium is an understudied chemical element that is quite useful in materials science and may be an essential astrochemical building block for grain formation in proto-planetary disks. This work provides quantum chemical prediction for the vibrational and rovibrational spectra of the structurally similar magnesium hydride and magnesium fluoride monomers and dimers. Magnesium fluoride is commonly utilized in infrared-observing windows and is a known terrestrial mineral, sellaite. Magnesium hydride is likely to exist in various astrophysical environments. Comparison of the anharmonic quantum chemical spectral data computed in this work to known gas phase values for MgH2 is excellent with the computed 1584.1 cm-1 antisymmetric Mg-H stretch less than 5 cm-1 below experiment for example. The condensed phase vibrational attributions of the dimer, however, are less comparable with the present results potentially indicating that some of the previous assignments may need to be revisited. The magnesium fluoride monomer and dimer have no previous vibrational experimental results reported, and the work here should be solid predictions as to their spectral features for comparison either to laboratory work or potentially even to interstellar observations.

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