Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 10.435
Filtrar
2.
Chaos ; 34(9)2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-39231292

RESUMEN

This work presents a heuristic for the selection of a time delay based on optimizing the global maximum of mutual information in orthonormal coordinates for embedding a dynamical system. This criterion is demonstrated to be more robust compared to methods that utilize a local minimum, as the global maximum is guaranteed to exist in the proposed coordinate system for any dynamical system. By contrast, methods using local minima can be ill-posed as a local minimum can be difficult to identify in the presence of noise or may simply not exist. The performance of the global maximum and local minimum methods are compared in the context of causality detection using convergent cross mapping using both a noisy Lorenz system and experimental data from an oscillating plasma source. The proposed heuristic for time lag selection is shown to be more consistent in the presence of noise and closer to an optimal uniform time lag selection.

3.
J Am Chem Soc ; 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39236092

RESUMEN

The assembly of metal-organic cages is governed by metal ion coordination preferences and the geometries of the typically rigid and planar precursor ligands. PdnL2n cages are among the most structurally diverse, with subtle differences in the metal-ligand coordination vectors resulting in drastically different assemblies, however almost all rely on rigid aromatic linkers to avoid the formation of intractable mixtures. Here we exploit the inverse electron-demand Diels-Alder (IEDDA) reaction between tetrazine linker groups and alkene reagents to trigger structural changes induced by post-assembly modification. The structure of the 1,4-dihydropyridazine produced by IEDDA (often an afterthought in click chemistry) is crucial; its two sp3 centers increase flexibility and nonplanarity, drastically changing the range of accessible coordination vectors. This triggers an initial Pd4L8 tetrahedral cage to transform into different Pd2L4 lantern cages, with both the transformation extent (thermodynamics) and rate (kinetics) dependent on the alkene dienophile selected. With cyclopentene, the unsymmetrical 1,4-dihydropyridazine ligands undergo integrative sorting in the solid state, with both head-to-tail orientation and enantiomer selection, leading to a single isomer from the 39 possible. This preference is rationalized through entropy, symmetry, and hydrogen bonding. Subsequent oxidation of the 1,4-dihydropyridazine to the aromatic pyridazine rigidifies the ligands, restoring planarity. The oxidized ligands no longer fit in the lantern structure, inducing further structural transformations into Pd4L8 tetrahedra and Pd3L6 double-walled triangles. The concept of controllable addition of limited additional flexibility and then its removal through well-defined reactivity we envisage being of great interest for structural transformations of any class of supramolecular architecture.

4.
Math Biosci ; : 109289, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39243940

RESUMEN

Macrophages are a type of white blood cell that play a significant role in determining the inflammatory response associated with a wide range of medical conditions. They are highly plastic, having the capacity to adopt numerous polarisation states or 'phenotypes' with disparate pro- or anti-inflammatory roles. Many previous studies divide macrophages into two categorisations: M1 macrophages are largely pro-inflammatory in nature, while M2 macrophages are largely restorative. However, there is a growing body of evidence that the M1 and M2 classifications represent the extremes of a much broader spectrum of phenotypes, and that intermediate phenotypes can play important roles in the progression or treatment of many medical conditions. In this article, we present a model of macrophage dynamics that includes a continuous description of phenotype, and hence incorporates intermediate phenotype configurations. We describe macrophage phenotype switching via nonlinear convective flux terms that scale with background levels of generic pro- and anti-inflammatory mediators. Through numerical simulation and bifurcation analysis, we unravel the model's resulting dynamics, paying close attention to the system's multistability and the extent to which key macrophage-mediator interactions provide bifurcations that act as switches between chronic states and restoration of health. We show that interactions that promote M1-like phenotypes generally result in a greater array of stable chronic states, while interactions that promote M2-like phenotypes can promote restoration of health. Additionally, our model admits oscillatory solutions reminiscent of relapsing-remitting conditions, with macrophages being largely polarised toward anti-inflammatory activity during remission, but with intermediate phenotypes playing a role in inflammatory flare-ups. We conclude by reflecting on our observations in the context of the ongoing pursuance of novel therapeutic interventions.

5.
ACS Macro Lett ; : 1226-1232, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39248726

RESUMEN

A simple and effective strategy to obtain solid-state multicolor emitting materials is a particularly attractive topic. Nonconventional/nonconjugated polymers are receiving widespread attention because of their advantages of rich structural diversity, low cost, and good processability. However, it is difficult to control the molecular conformation or to obtain the crystal structure of amorphous molecules, which means it is a challenge to obtain nontraditional polymeric materials with multicolor emission. In this work, a polyurethane derivative (PUH) with red-shifted emission was synthesized by a simple one-pot polymerization reaction. By exploiting the aggregation-induced luminochromism of PUH, a series of plastic films with tunable emission from blue to orange, and white-light emission, was obtained by doping different amounts of PUH into poly(methyl methacrylate) (PMMA), thereby changing the aggregation degree of PUH. This work demonstrates the excellent promise of polyurethane derivatives for the simple fabrication of large-scale flexible luminescent films.

6.
J Dairy Sci ; 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39245171

RESUMEN

Limited literature is available identifying phenotypical traits related to enteric methane (CH4) production from dairy cows, despite its relevance in relation to breeding for animals with a low CH4 yield (g/kg DMI), and the derived consequences hereof. This study aimed to investigate the relationships between CH4 yield and different animal phenotypes when 16 2nd parity dairy cows, fitted with a ruminal cannula, were fed 2 diets differing in forage:concentrate ratio in a crossover design. The diets had either a low forage proportion (35% on DM basis, F35) or a high forage proportion (63% on DM basis, F63). Gas exchange was measured by means of indirect calorimetry. Spot samples of feces were collected, and indigestible NDF (INDF) was used as an internal marker to determine total-tract digestibility. In addition, ruminal evacuations, monitoring of chewing activity, determination of ruminal VFA concentration, analysis of relative abundance of methanogens, and measurement of liquid passage rate were performed. Statistical differences were analyzed by a linear mixed model with diet, days in milk, and period as fixed effects, and cow as random effect. The random cow estimates (RCE) were extracted from the model to get the Pearson correlations (r) between RCE of CH4 yield with RCE of all other variables measured, to identify possible phenotypes related to CH4 yield. Significant correlations were observed between RCE of CH4 yield and RCE of OM digestibility (r = 0.63) and ruminal concentration of valeric acid (r = -0.61), acetic acid (r = 0.54), ammonium (r = 0.55), and lactic acid (r = ‒0.53). Additionally, tendencies were observed for correlations between RCE of CH4 yield and RCE of H2 yield in g/kg DM (r = 0.47, P = 0.07), and ruminal isobutyric acid concentration (r = 0.43, P = 0.09). No correlations were observed between RCE of CH4 yield and RCE of ruminal pool sizes, milk data, urinary measurements, or chewing activity. Cows had a lower DMI and ECM, when they were fed F63 compared with F35. Cows fed F63 had higher NDF digestibility, CH4 emissions (g/d, g/kg of DMI, and g/kg of ECM), ruminal concentration of acetic acid, ruminal pH, degradation rate of digestible NDF (DNDF, %/h), and longer rumen retention time (h). Also, rumination and total chewing time (min/kg DMI) were higher for cows fed F63. The results in the present study emphasize the positive relation between cow's ability to digest OM and their CH4 emissions. The derived consequences of breeding for lower CH4 emission might be cows with lower ability to digest OM, but more studies are warranted for further documentation of this relationship.

7.
Basic Clin Androl ; 34(1): 14, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39223491

RESUMEN

BACKGROUND: Primary hypogonadism is a recognised complication in survivors of testicular cancer. However, secondary hypogonadism can result from other causes that suppress the hypothalamic-pituitary axis, including obesity, high dose glucocorticoids, chronic end organ failure, and diabetes. The aim of this study was to explore low total serum testosterone in Australian survivors of testicular cancer and examine associations with body mass index, age, and prior chemotherapy use. METHODS: Clinical data including height, weight, diagnosis, treatment, and hormonal evaluations during follow-up were extracted from the Australian and New Zealand Urogenital and Prostate (ANZUP) Cancer Trials Group Chemocog study (2007-2012), accompanied by data from two Australian, high-volume testicular cancer centres included in the iTestis testicular cancer registry (2012-2019). Low testosterone was defined by a serum concentration of testosterone (T) < 10 nmol/L, and was classified as primary by a serum concentration of luteinising hormone (LH) > 8 IU/L, otherwise as secondary. RESULTS: Two hundred eighty-five individuals with either stage 1 or advanced testicular cancer were included. Of these, 105 (37%) were treated with orchidectomy and chemotherapy. Forty-nine (17%) met criteria for low testosterone during follow-up: 21 (43%) had primary and 27 (55%) had secondary low testosterone. Survivors of testicular cancer with higher body mass index were more likely to display low testosterone, both primary (p = 0.032) and secondary (p = 0.028). Our data did not show evidence of an association between older age or chemotherapy use and low testosterone in our cohort. CONCLUSIONS: Low total serum testosterone was common in survivors of testicular cancer, and associated with a higher body mass index prior to orchidectomy, suggesting that elevated body mass index may contribute to low testosterone in this population, and that body weight, diet, and exercise should be addressed in testicular cancer follow-up.


RéSUMé: CONTEXTE: L'hypogonadisme primaire est une complication reconnue chez les survivants d'un cancer du testicule. Cependant, l'hypogonadisme secondaire peut résulter d'autres causes qui suppriment l'axe hypothalamo-hypophysaire, notamment l'obésité, les glucocorticoïdes à forte dose, la défaillance chronique des organes cibles et le diabète. Le but de cette étude était d'explorer un faible taux de testostérone totale sérique chez les survivants australiens d'un cancer du testicule, et d'examiner les associations avec l'indice de masse corporelle, l'âge et l'utilisation antérieure d'une chimiothérapie. Les données cliniques, y compris la taille, le poids, le diagnostic, le traitement et les évaluations hormonales au cours du suivi, ont été extraites de l'étude Chemocog de l'Australian and New Zealand Urogenital and Prostate (ANZUP) Cancer Trials Group (2007­2012), accompagnées de données, provenant de deux centres australiens à fort volume de prise en charge de cancers du testicule, incluses dans le registre du cancer du testicule iTestis (2012­2019). Un taux faible de testostérone a été défini par une concentration sérique de testostérone (T) < 10 nmol/L, et a été classé comme primaire pour une concentration sérique d'hormone lutéinisante (LH) > 8 UI/L, sinon comme secondaire. RéSULTATS: Deux cent quatre-vingt-cinq personnes atteintes d'un cancer des testicules de stade 1 ou avancé ont été incluses. Parmi ceux-ci, 105 (37%) ont été traités par orchidectomie et chimiothérapie. Quarante-neuf (17%) répondaient aux critères d'un taux faible de testostérone au cours du suivi: 21 (43%) avaient un taux faible de testostérone primaire et 27 (55%) un faible taux secondaire. Les survivants d'un cancer du testicule avec un indice de masse corporelle plus élevé étaient plus susceptibles de présenter un taux faible de testostérone, à la fois primaire (p = 0,032) et secondaire (p = 0,028). Nos données n'ont pas montré de preuve d'une association entre un âge avancé ou l'utilisation de la chimiothérapie, et un taux faible de testostérone, dans notre cohorte. CONCLUSIONS: Un faible taux de testostérone sérique totale était fréquent chez les survivants d'un cancer du testicule, et associé à un indice de masse corporelle plus élevé avant l'orchidectomie; ceci suggère qu'un indice de masse corporelle élevé peut contribuer à un faible taux de testostérone dans cette population, et que le poids corporel, l'alimentation et l'exercice devraient être pris en compte dans le suivi du cancer du testicule.

8.
J Neurol ; 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39230722

RESUMEN

BACKGROUND: Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) have clinical, pathological and genetic overlapping. Lipid pathways are implicated in ALS. This study examined the effect of blood lipid levels on ALS, FTD risk, and survival in ALS. METHODS: A systematic review and meta-analysis of high and low-density lipoprotein cholesterol (HDL-c and LDL-c), total cholesterol, triglycerides, apolipoproteins B and A1 levels with ALS was performed. Two-sample Mendelian randomisation (MR) analysis sought the causal effects of these exposures on ALS, FTD, and survival in ALS. The effect of lipid-lowering drugs was also examined using genetic proxies for targets of lipid-lowering medications. RESULTS: Three cohort studies met the inclusion criteria for meta-analysis. Meta-analysis indicated an association between higher LDL-c (HRper mmol/L = 1.07, 95%CI:1.02-1.12; I 2 =18%) and lower HDL-c (HRper mmol/L = 0.83, 95%CI:0.74-0.94; I 2 =0%) with an increased risk of ALS. MR suggested causal effects of higher LDL-c (ORIVW = 1.085, 95%:CI 1.008-1.168, pFDR = 0.0406), total cholesterol (ORIVW = 1.081, 95%:CI 1.013-1.154, pFDR = 0.0458) and apolipoprotein B (ORIVW = 1.104, 95%:CI 1.041-1.171, pFDR = 0.0061) increasing ALS risk, and higher apolipoprotein B level increasing FTD risk (ORIVW = 1.424, 95%CI 1.072-1.829, pFDR = 0.0382). Reducing LDL-c through APOB inhibition was associated with lower ALS (ORIVW = 0.84, 95%CI 0.759-0.929, pFDR = 0.00275) and FTD risk (ORIVW = 0.581, 95%CI 0.387-0.874, pFDR = 0.0362). CONCLUSION: These data support the influence of LDL-c and total cholesterol on ALS risk and apolipoprotein B on the risk of ALS and FTD. Potential APOB inhibition might decrease the risk of sporadic ALS and FTD. Further work in monogenic forms of ALS and FTD is necessary to determine whether blood lipids influence penetrance and phenotype.

9.
Inorg Chem ; 63(35): 16404-16417, 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39150967

RESUMEN

The limited optical penetration depth and hypoxic tumor microenvironment (TME) are key factors that hinder the practical applications of conventional photodynamic therapy (PDT). To fundamentally address these issues, self-luminescent photosensitizers (PSs) can achieve efficient PDT. Herein, a self-chemiluminescence (CL)-triggered Ir complex PS, namely, IrL2, with low-O2-dependence type I photochemical processes is reported for efficient PDT. The rational design achieves efficient chemiluminescence resonance energy transfer (CRET) from covalently bonded luminol units to the Ir complex in IrL2 under the catalysis of H2O2 and hemoglobin (Hb) to generate O2•- and 1O2. Liposome IrL2H nanoparticles (NPs) are constructed by loading IrL2 and Hb. The intracellular H2O2 and loaded Hb catalyze the luminol part of IrL2H, and the Ir2 part is then excited to produce types I and II reactive oxygen species (ROS) through CRET, inducing cell death, even under hypoxic conditions, and promoting cell apoptosis. IrL2H is used for tumor imaging and inhibits tumor growth in 4T1-bearing mouse models through intratumoral injection without external light sources. This work provides new designs for transition metal complex PSs that conquer the limitations of external light sources and the hypoxic TME in PDT.


Asunto(s)
Iridio , Fotoquimioterapia , Fármacos Fotosensibilizantes , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/síntesis química , Animales , Iridio/química , Iridio/farmacología , Ratones , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Complejos de Coordinación/síntesis química , Luminiscencia , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Apoptosis/efectos de los fármacos , Humanos , Ratones Endogámicos BALB C , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Hipoxia Tumoral/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Femenino , Supervivencia Celular/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Estructura Molecular
10.
ASAIO J ; 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39116303

RESUMEN

We present the case of a 62-year-old man with severe coronary artery disease who presented to the hospital in refractory ventricular fibrillation cardiac arrest. He showed signs of life despite prolonged resuscitation. We thus decided to initiate extracorporeal cardiopulmonary resuscitation (ECPR). The patient had a known total occlusion of his infrarenal aorta that had been surgically bypassed with a bifemoral-axillary graft. We successfully initiated ECPR via the surgical graft, establishing blood flow to the central circulation through the axillary artery in a peripheral configuration while ensuring blood flow to the left leg via the femoral-femoral graft. The patient was extubated neurologically intact the following day and subsequently underwent coronary artery bypass graft surgery while on extracorporeal membrane oxygenation (ECMO) support. He was subsequently weaned off inotropic support and decannulated from ECMO. He was discharged home neurologically intact and independent in his activities of daily living. This case demonstrates that cannulation for ECPR via a surgical vascular graft is possible and that a total occlusion of the infrarenal aorta in the presence of a surgical bypass is not an absolute contraindication to ECMO.

11.
Chem Mater ; 36(15): 7135-7150, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39156711

RESUMEN

The efficiency of thermally activated delayed fluorescence (TADF) in organic materials relies on rapid intersystem crossing rates and fast conversion of triplet (T) excitons into a singlet (S) state. Heavy atoms such as sulfur or selenium are now frequently incorporated into TADF molecular structures to enhance these properties by increased spin-orbit coupling [spin orbit coupling (SOC)] between the T and S states. Here a series of donor-acceptor (D-A) molecules based on 12H-benzo[4,5]thieno[2,3-a]carbazole and dicyanopyridine is compared with their nonsulfur control molecules designed to probe such SOC effects. We reveal that unexpected intermolecular interactions of the D-A molecules with carbazole-containing host materials instead serve as the dominant pathway for triplet decay kinetics in these materials. In-depth photophysical and computational studies combined with organic light emitting diode measurements demonstrate that the anticipated heavy-atom effect from sulfur is overshadowed by exciplex formation. Indeed, even the unsubstituted acceptor fragments exhibit pronounced TADF exciplex emission in appropriate carbazole hosts. The intermolecular charge transfer and TADF in these systems are further confirmed by detailed time-dependent density functional theory studies. This work demonstrates that anticipated heavy-atom effects in TADF emitters do not always control or even impact the photophysical and electroluminescence properties.

12.
JCO Clin Cancer Inform ; 8: e2300233, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39121392

RESUMEN

PURPOSE: Outcome for patients with nonmetastatic, microsatellite instability (MSI) colon cancer is favorable: however, high-risk cohorts exist. This study was aimed at developing and validating a nomogram model to predict freedom from recurrence (FFR) for patients with resected MSI colon cancer. PATIENTS AND METHODS: Data from patients who underwent curative resection of stage I, II, or III MSI colon cancer in 2014-2021 (model training cohort, 384 patients, 33 events; median follow-up, 38.8 months) were retrospectively collected from institutional databases. Variables associated with recurrence in multivariable analysis were selected for inclusion in the clinical calculator. The calculator's predictive accuracy was measured with the concordance index and validated using data from patients who underwent treatment for MSI colon cancer in 2007-2013 (validation cohort, 164 patients, eight events; median follow-up, 84.8 months). RESULTS: T category and number of positive lymph nodes were significantly associated with recurrence in multivariable analysis and were selected for inclusion in the clinical calculator. The calculator's concordance index for FFR in the model training cohort was 0.812 (95% CI, 0.742 to 0.873), compared with 0.759 (95% CI, 0.683 to 0.840) for the staging schema of the eighth edition of the American Joint Committee on Cancer Staging Manual. The concordance index for the validation cohort was 0.744 (95% CI, 0.666 to 0.822), confirming robust predictive accuracy. CONCLUSION: Although in general patients with nonmetastatic MSI colon cancer had favorable outcome, patients with advanced T category and multiple metastatic lymph nodes had higher risk of recurrence. The clinical calculator identified patients with MSI colon cancer at high risk for recurrence, and this could inform surveillance strategies. In addition, the model could be used in trial design to identify patients suitable for novel adjuvant therapy.


Asunto(s)
Neoplasias del Colon , Inestabilidad de Microsatélites , Recurrencia Local de Neoplasia , Estadificación de Neoplasias , Humanos , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Neoplasias del Colon/cirugía , Neoplasias del Colon/diagnóstico , Femenino , Masculino , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Persona de Mediana Edad , Anciano , Nomogramas , Estudios Retrospectivos , Pronóstico , Adulto
13.
JAMA Netw Open ; 7(8): e2427073, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39120898

RESUMEN

Importance: Black or African American (hereinafter, Black) and Hispanic or Latino/a/x (hereinafter, Latinx) adults are disproportionally affected by Alzheimer disease, but most research studies do not enroll adequate numbers of both of these populations. The Alzheimer's Disease Neuroimaging Initiative-3 (ADNI3) launched a diversity taskforce to pilot a multipronged effort to increase the study inclusion of Black and Latinx older adults. Objective: To describe and evaluate the culturally informed and community-engaged inclusion efforts to increase the screening and enrollment of Black and Latinx older adults in ADNI3. Design, Setting, and Participants: This cross-sectional study used baseline data from a longitudinal, multisite, observational study conducted from January 15, 2021, to July 12, 2022, with no follow-up. The study was conducted at 13 ADNI3 sites in the US. Participants included individuals aged 55 to 90 years without cognitive impairment and those with mild cognitive impairment or Alzheimer disease. Exposures: Efforts included (1) launch of an external advisory board, (2) changes to the study protocol, (3) updates to the digital prescreener, (4) selection and deployment of 13 community-engaged research study sites, (5) development and deployment of local and centralized outreach efforts, and (6) development of a community-science partnership board. Main Outcomes and Measures: Screening and enrollment numbers from centralized and local outreach efforts, digital advertisement metrics, and digital prescreener completion. Results: A total of 91 participants enrolled in the trial via centralized and local outreach efforts, of which 22 (24.2%) identified as Latinx and 55 (60.4%) identified as Black (median [IQR] age, 65.6 [IQR, 61.5-72.5] years; 62 women [68.1%]). This represented a 267.6% increase in the monthly rate of enrollment (before: 1.11 per month; during: 4.08 per month) of underrepresented populations. For the centralized effort, social media advertisements were run between June 1, 2021, and July 31, 2022, which resulted in 2079 completed digital prescreeners, of which 1289 met criteria for subsequent site-level screening. Local efforts were run between June 1, 2021, to July 31, 2022. A total of 151 participants underwent site-level screening (100 from local efforts, 41 from centralized efforts, 10 from other sources). Conclusions and Relevance: In this cross-sectional study of pilot inclusion efforts, a culturally informed, community-engaged approach increased the inclusion of Black and Latinx participants in an Alzheimer disease cohort study.


Asunto(s)
Enfermedad de Alzheimer , Negro o Afroamericano , Hispánicos o Latinos , Humanos , Enfermedad de Alzheimer/etnología , Anciano , Femenino , Masculino , Estudios Transversales , Anciano de 80 o más Años , Persona de Mediana Edad , Hispánicos o Latinos/estadística & datos numéricos , Negro o Afroamericano/estadística & datos numéricos , Selección de Paciente , Estados Unidos , Estudios Longitudinales , Disfunción Cognitiva
15.
Healthcare (Basel) ; 12(16)2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39201207

RESUMEN

A growing body of evidence suggests an increased prevalence of anxiety and depression among teachers during the COVID-19 pandemic. However, there is little evidence in research documenting the extent of anxiety and depression in the university teacher population and how these relate to feelings of loneliness. This study aims to explore the prevalence of anxiety and depression symptoms among university teachers, identify differences, and further examine the relationships between loneliness and symptoms of anxiety and depression. The study participants included university teachers in the College of Health and Medical Sciences from four purposefully selected public universities who completed a survey questionnaire consisting of items that measured anxiety and depressive symptoms as well as loneliness. The final sample included 148 participants (45 participants [30.4%] located in the center or capital; 125 (83.1%) men; and 90 [62.5%] taught both online and face-to-face). The university teachers' sample mean age = 39.07 had an SD = 7.67. As per the findings of this study, the prevalence of anxiety and depression symptoms was significant (11% and 12.3%) among university teachers in Ethiopia during the COVID-19 pandemic. Also, this study found a significant association between these symptoms and loneliness. Therefore, incorporating relevant strategies to promote mental well-being and targeting individuals who felt lonely were essential for overcoming health-related burdens. Universities should equip teachers with resources to prevent mental health issues and offer need-based counseling services to alleviate them.

16.
Ann Am Thorac Soc ; 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39163618
17.
medRxiv ; 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39148846

RESUMEN

This manuscript describes and summarizes the Dominantly Inherited Alzheimer Network Observational Study (DIAN Obs), highlighting the wealth of longitudinal data, samples, and results from this human cohort study of brain aging and a rare monogenic form of Alzheimer's disease (AD). DIAN Obs is an international collaborative longitudinal study initiated in 2008 with support from the National Institute on Aging (NIA), designed to obtain comprehensive and uniform data on brain biology and function in individuals at risk for autosomal dominant AD (ADAD). ADAD gene mutations in the amyloid protein precursor (APP), presenilin 1 (PSEN1), or presenilin 2 (PSEN2) genes are deterministic causes of ADAD, with virtually full penetrance, and a predictable age at symptomatic onset. Data and specimens collected are derived from full clinical assessments, including neurologic and physical examinations, extensive cognitive batteries, structural and functional neuro-imaging, amyloid and tau pathological measures using positron emission tomography (PET), flurordeoxyglucose (FDG) PET, cerebrospinal fluid and blood collection (plasma, serum, and whole blood), extensive genetic and multi-omic analyses, and brain donation upon death. This comprehensive evaluation of the human nervous system is performed longitudinally in both mutation carriers and family non-carriers, providing one of the deepest and broadest evaluations of the human brain across decades and through AD progression. These extensive data sets and samples are available for researchers to address scientific questions on the human brain, aging, and AD.

18.
Biomed Phys Eng Express ; 10(5)2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39173647

RESUMEN

This study introduces a novel volume coil design that features two slotted end-plates connected by six rungs, resembling the traditional birdcage coil. The end rings are equipped with six evenly distributed circular slots, inspired by Mansfield's cavity resonator theory, which suggests that circular slots can generate a baseline resonant frequency. One notable advantage of this proposed coil design is its reduced reliance on electronic components compared to other volume coils, making it more efficient. Additionally, the dimensions of the coil can be theoretically computed in advance, enhancing its practicality. To evaluate the performance and safety of the coil, electromagnetic field and specific absorption rate simulations were simulated using a cylindrical saline phantom and the finite element method. Furthermore, a transceiver coil prototype optimized for 7 Tesla and driven in quadrature was constructed, enabling whole-body imaging of rats. The resonant frequency of the coil prototype obtained through experimental measurements closely matched the theoretical frequency derived from Mansfield's theory. To validate the coil design, phantom images were acquired to demonstrate its viability and assess its performance. These images also served to validate the magnetic field simulations. The experimental results aligned well with the simulation findings, confirming the reliability of the proposed coil design. Importantly, the prototype coil showcased significant improvements over a similarly-sized birdcage coil, indicating its potential for enhanced performance. The noise figure was lower in the prototype versus the birdcage coil (NFbirdcage-NFslotcage= 0.7). Phantom image data were also used to compute the image SNR, giving SNRslotcage/SNRbirdcage= 34.36/24.34. By proving the feasibility of the coil design through successful rat whole-body imaging, the study provides evidence supporting its potential as a viable option for high-field MRI applications on rodents.


Asunto(s)
Diseño de Equipo , Imagen por Resonancia Magnética , Fantasmas de Imagen , Ondas de Radio , Animales , Imagen por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/instrumentación , Ratas , Simulación por Computador , Campos Electromagnéticos , Análisis de Elementos Finitos , Campos Magnéticos , Imagen de Cuerpo Entero/métodos , Imagen de Cuerpo Entero/instrumentación
20.
Ann Anat ; 256: 152320, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39182586

RESUMEN

To learn and comprehend the large amount of information in gross anatomy, undergraduate students must self-regulate their learning to be properly prepared for the exams within the available time. Even though there are many studies on learning strategies and their influence on test results and motivation, the aim of this study is to investigate characteristics of learning strategies in detail and in relation to the anatomy course of first semester students and how their use is related to anatomy test performance. For assessing the learning strategies, we used the short version of the questionnaire "Learning Strategies of University Students" (LIST-K) (Klingsieck, 2018). Further, we investigated potential influences of motivation and resources used during the self-regulated learning process. The participants in this study (N = 108) filled in the above-mentioned questionnaire LIST-K and a written multiple-choice anatomy test. A k-means cluster analysis revealed three groups of students differing in their self-reported use of learning strategies. Students used either (1) predominantly metacognitive and resource-related strategies, (2) predominantly cognitive strategies, or (3) no specific learning strategies at all. We found no significant overall relationships between the use of learning strategies and test performance. A stepwise linear regression identified the use of cognitive learning strategies (ß =.269) as a significant predictor for test performance (R² =.149, p =.003), possibly as these specific learning strategies help with a systematic and effective approach while studying anatomy and retrieving large amount of memorized information. Further, motivation was identified as a negative predictor (ß = -.277), which might be a result of the short time periods students have to study for exams. Overall findings underline the importance of self-regulated learning as a positive predictor for academic performance. By understanding these factors, a more student-centered approach could be adopted by educators to improve medical education and equip students with valuable approaches for their continuous education, even beyond university.


Asunto(s)
Anatomía , Educación de Pregrado en Medicina , Evaluación Educacional , Aprendizaje , Motivación , Estudiantes de Medicina , Humanos , Anatomía/educación , Educación de Pregrado en Medicina/métodos , Estudiantes de Medicina/psicología , Masculino , Femenino , Adulto Joven , Encuestas y Cuestionarios , Adulto , Adolescente
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...