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result(s) for
"Santos, Mark D."
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Bridging the generational gap between nurses and nurse managers: a qualitative study from Qatar
by
Abujaber, Ahmad A.
,
Al-Lobaney, Nabeel F.
,
Alomari, Albara M.
in
Age differences
,
Analysis
,
Baby boomers
2024
Background
The nursing workforce comprises multiple generations, each with unique values, beliefs, and expectations that can influence communication, work ethic, and professional relationships. In Qatar, the generational gap between nurses and nurse managers poses challenges to effective communication and teamwork, impacting job satisfaction and patient outcomes.
Aim
This study investigates the generational gap between nurses and nurse managers in Qatar, aiming to identify strategies to enhance collaboration and create a positive work environment.
Methods
A qualitative research design was used, involving semi-structured interviews with 20 participants, including frontline nurses and senior nurse managers. Participants were purposively sampled to represent different generations. Data were collected through face-to-face and virtual interviews, then transcribed and thematically analyzed.
Findings
Four key themes emerged:
Optimizing the Work Environment
: Older generations preferred transformational and situational leadership, while younger nurses valued respect, teamwork, accountability, and professionalism.
Strengthening Work Atmosphere through Communication and values
: Older nurses favored face-to-face communication, while younger nurses preferred digital tools.
Cultivating Respect and Empathy
: Younger nurses emphasized fairness in assignments and promotions, while older nurses focused on empathy and understanding.
Dynamic Enhancement of Healthcare Systems
: Younger nurses were more adaptable to technology and professional development, while older nurses prioritized clinical care and patient outcomes.
Conclusion
The study reveals significant generational differences in leadership preferences, communication styles, and adaptability to technology. Addressing these gaps through effective leadership, ongoing education, and open communication can improve job satisfaction and patient care.
Journal Article
Quantum-Fluctuation-Driven Crossover from a Dilute Bose-Einstein Condensate to a Macrodroplet in a Dipolar Quantum Fluid
by
Petter, D.
,
Chomaz, L.
,
Wächtler, F.
in
Bose-Einstein condensates
,
Density distribution
,
Dilution
2016
In a joint experimental and theoretical effort, we report on the formation of a macrodroplet state in an ultracold bosonic gas of erbium atoms with strong dipolar interactions. By precise tuning of the s -wave scattering length below the so-called dipolar length, we observe a smooth crossover of the ground state from a dilute Bose-Einstein condensate to a dense macrodroplet state of more than 2×104atoms . Based on the study of collective excitations and loss features, we prove that quantum fluctuations stabilize the ultracold gas far beyond the instability threshold imposed by mean-field interactions. Finally, we perform expansion measurements, showing that although self-bound solutions are prevented by losses, the interplay between quantum stabilization and losses results in a minimal time-of-flight expansion velocity at a finite scattering length.
Journal Article
Ultrafast photochemistry produces superbright short-wave infrared dots for low-dose in vivo imaging
2020
Optical probes operating in the second near-infrared window (NIR-II, 1,000-1,700 nm), where tissues are highly transparent, have expanded the applicability of fluorescence in the biomedical field. NIR-II fluorescence enables deep-tissue imaging with micrometric resolution in animal models, but is limited by the low brightness of NIR-II probes, which prevents imaging at low excitation intensities and fluorophore concentrations. Here, we present a new generation of probes (Ag
2
S superdots) derived from chemically synthesized Ag
2
S dots, on which a protective shell is grown by femtosecond laser irradiation. This shell reduces the structural defects, causing an 80-fold enhancement of the quantum yield. PEGylated Ag
2
S superdots enable deep-tissue in vivo imaging at low excitation intensities (<10 mW cm
−2
) and doses (<0.5 mg kg
−1
), emerging as unrivaled contrast agents for NIR-II preclinical bioimaging. These results establish an approach for developing superbright NIR-II contrast agents based on the synergy between chemical synthesis and ultrafast laser processing.
Deep tissue imaging has been limited by the low brightness of probes emitting in the second near-infrared window. Here, the authors use femtosecond laser irradiation to grow a protective shell on Ag
2
S nanoparticles, achieving 80-fold quantum yield enhancement and imaging with low excitation intensities.
Journal Article
Observation of roton mode population in a dipolar quantum gas
2018
The concept of a roton, a special kind of elementary excitation forming a minimum of energy at finite momentum, has been essential for the understanding of the properties of superfluid 4He (ref. 1). In quantum liquids, rotons arise from the strong interparticle interactions, whose microscopic description remains debated2. In the realm of highly controllable quantum gases, a roton mode has been predicted to emerge due to magnetic dipole–dipole interactions despite their weakly interacting character3. This prospect has raised considerable interest4–12; yet roton modes in dipolar quantum gases have remained elusive to observations. Here we report experimental and theoretical studies of the momentum distribution in Bose–Einstein condensates of highly magnetic erbium atoms, revealing the existence of the long-sought roton mode. Following an interaction quench, the roton mode manifests itself with the appearance of symmetric peaks at well-defined finite momentum. The roton momentum follows the predicted geometrical scaling with the inverse of the confinement length along the magnetization axis. From the growth of the roton population, we probe the roton softening of the excitation spectrum in time and extract the corresponding imaginary roton gap. Our results provide a further step in the quest towards supersolidity in dipolar quantum gases13.
Journal Article
Clonally expanded CD8 T cells patrol the cerebrospinal fluid in Alzheimer’s disease
2020
Alzheimer’s disease is an incurable neurodegenerative disorder in which neuroinflammation has a critical function
1
. However, little is known about the contribution of the adaptive immune response in Alzheimer’s disease
2
. Here, using integrated analyses of multiple cohorts, we identify peripheral and central adaptive immune changes in Alzheimer’s disease. First, we performed mass cytometry of peripheral blood mononuclear cells and discovered an immune signature of Alzheimer’s disease that consists of increased numbers of CD8
+
T effector memory CD45RA
+
(T
EMRA
) cells. In a second cohort, we found that CD8
+
T
EMRA
cells were negatively associated with cognition. Furthermore, single-cell RNA sequencing revealed that T cell receptor (TCR) signalling was enhanced in these cells. Notably, by using several strategies of single-cell TCR sequencing in a third cohort, we discovered clonally expanded CD8
+
T
EMRA
cells in the cerebrospinal fluid of patients with Alzheimer’s disease. Finally, we used machine learning, cloning and peptide screens to demonstrate the specificity of clonally expanded TCRs in the cerebrospinal fluid of patients with Alzheimer’s disease to two separate Epstein–Barr virus antigens. These results reveal an adaptive immune response in the blood and cerebrospinal fluid in Alzheimer’s disease and provide evidence of clonal, antigen-experienced T cells patrolling the intrathecal space of brains affected by age-related neurodegeneration.
An integrated analysis of several cohorts shows that clonal, antigen-experienced T cells are found in the cerebrospinal fluid of patients with Alzheimer’s disease, suggesting that the adaptive immune system has a role in age-related neurodegeneration.
Journal Article
Tau molecular diversity contributes to clinical heterogeneity in Alzheimer’s disease
by
Dujardin, Simon
,
Commins, Caitlin
,
Tanzi, Rudolph E.
in
631/378/1689/1283
,
631/45/470/2284
,
631/45/612/1246
2020
Alzheimer’s disease (AD) causes unrelenting, progressive cognitive impairments, but its course is heterogeneous, with a broad range of rates of cognitive decline
1
. The spread of tau aggregates (neurofibrillary tangles) across the cerebral cortex parallels symptom severity
2
,
3
. We hypothesized that the kinetics of tau spread may vary if the properties of the propagating tau proteins vary across individuals. We carried out biochemical, biophysical, MS and both cell- and animal-based-bioactivity assays to characterize tau in 32 patients with AD. We found striking patient-to-patient heterogeneity in the hyperphosphorylated species of soluble, oligomeric, seed-competent tau. Tau seeding activity correlates with the aggressiveness of the clinical disease, and some post-translational modification (PTM) sites appear to be associated with both enhanced seeding activity and worse clinical outcomes, whereas others are not. These data suggest that different individuals with ‘typical’ AD may have distinct biochemical features of tau. These data are consistent with the possibility that individuals with AD, much like people with cancer, may have multiple molecular drivers of an otherwise common phenotype, and emphasize the potential for personalized therapeutic approaches for slowing clinical progression of AD.
A molecular analysis of tau from patients with sporadic Alzheimer’s disease reveals striking diversity in biochemical properties between patients, which influences seeding activity and correlates with the aggressiveness of the disease.
Journal Article
Deep Visual Proteomics defines single-cell identity and heterogeneity
by
Hollandi, Réka
,
Schweizer, Lisa
,
Dyring-Andersen, Beatrice
in
631/45/475
,
631/553/2706
,
631/67/2329
2022
Despite the availabilty of imaging-based and mass-spectrometry-based methods for spatial proteomics, a key challenge remains connecting images with single-cell-resolution protein abundance measurements. Here, we introduce Deep Visual Proteomics (DVP), which combines artificial-intelligence-driven image analysis of cellular phenotypes with automated single-cell or single-nucleus laser microdissection and ultra-high-sensitivity mass spectrometry. DVP links protein abundance to complex cellular or subcellular phenotypes while preserving spatial context. By individually excising nuclei from cell culture, we classified distinct cell states with proteomic profiles defined by known and uncharacterized proteins. In an archived primary melanoma tissue, DVP identified spatially resolved proteome changes as normal melanocytes transition to fully invasive melanoma, revealing pathways that change in a spatial manner as cancer progresses, such as mRNA splicing dysregulation in metastatic vertical growth that coincides with reduced interferon signaling and antigen presentation. The ability of DVP to retain precise spatial proteomic information in the tissue context has implications for the molecular profiling of clinical samples.
Deep Visual Proteomics combines machine learning, automated image analysis and single-cell proteomics.
Journal Article
A human autoimmune organoid model reveals IL-7 function in coeliac disease
2024
In vitro models of autoimmunity are constrained by an inability to culture affected epithelium alongside the complex tissue-resident immune microenvironment. Coeliac disease (CeD) is an autoimmune disease in which dietary gluten-derived peptides bind to the major histocompatibility complex (MHC) class II human leukocyte antigen molecules (HLA)-DQ2 or HLA-DQ8 to initiate immune-mediated duodenal mucosal injury
1
–
4
. Here, we generated air–liquid interface (ALI) duodenal organoids from intact fragments of endoscopic biopsies that preserve epithelium alongside native mesenchyme and tissue-resident immune cells as a unit without requiring reconstitution. The immune diversity of ALI organoids spanned T cells, B and plasma cells, natural killer (NK) cells and myeloid cells, with extensive T-cell and B-cell receptor repertoires. HLA-DQ2.5-restricted gluten peptides selectively instigated epithelial destruction in HLA-DQ2.5-expressing organoids derived from CeD patients, and this was antagonized by blocking MHC-II or NKG2C/D. Gluten epitopes stimulated a CeD organoid immune network response in lymphoid and myeloid subsets alongside anti-transglutaminase 2 (TG2) autoantibody production. Functional studies in CeD organoids revealed that interleukin-7 (IL-7) is a gluten-inducible pathogenic modulator that regulates CD8
+
T-cell NKG2C/D expression and is necessary and sufficient for epithelial destruction. Furthermore, endogenous IL-7 was markedly upregulated in patient biopsies from active CeD compared with remission disease from gluten-free diets, predominantly in lamina propria mesenchyme. By preserving the epithelium alongside diverse immune populations, this human in vitro CeD model recapitulates gluten-dependent pathology, enables mechanistic investigation and establishes a proof of principle for the organoid modelling of autoimmunity.
A human in vitro model of coeliac disease comprising duodenal organoids that maintain both epithelium and an immune microenvironment finds a previously unsuspected role for IL-7 in gluten-induced epithelial destruction.
Journal Article
Pericyte remodeling is deficient in the aged brain and contributes to impaired capillary flow and structure
by
Coelho-Santos, Vanessa
,
Weber, Bruno
,
Stamenkovic, Stefan
in
14/69
,
631/378/1341
,
631/378/1689/1283
2022
Deterioration of brain capillary flow and architecture is a hallmark of aging and dementia. It remains unclear how loss of brain pericytes in these conditions contributes to capillary dysfunction. Here, we conduct cause-and-effect studies by optically ablating pericytes in adult and aged mice in vivo. Focal pericyte loss induces capillary dilation without blood-brain barrier disruption. These abnormal dilations are exacerbated in the aged brain, and result in increased flow heterogeneity in capillary networks. A subset of affected capillaries experience reduced perfusion due to flow steal. Some capillaries stall in flow and regress, leading to loss of capillary connectivity. Remodeling of neighboring pericytes restores endothelial coverage and vascular tone within days. Pericyte remodeling is slower in the aged brain, resulting in regions of persistent capillary dilation. These findings link pericyte loss to disruption of capillary flow and structure. They also identify pericyte remodeling as a therapeutic target to preserve capillary flow dynamics.
Using in vivo two-photon imaging, Berthiaume et al. demonstrate how pericyte loss during aging could contribute to deterioration of cerebral blood flow. They also show how pericyte remodeling reduces the deleterious effects of pericyte loss.
Journal Article
Genetic diversity and population structure of Piper nigrum (black pepper) accessions based on next-generation SNP markers
by
Samuel, Rosabelle
,
Ariyawansa, Kahandawa G. S. U.
,
Wimalarathna, Nilni A.
in
Analysis
,
Biological diversity
,
Biology and Life Sciences
2024
Despite the economic importance of Piper nigrum (black pepper), a highly valued crop worldwide, development and utilization of genomic resources have remained limited, with diversity assessments often relying on only a few samples or DNA markers. Here we employed restriction-site associated DNA sequencing to analyze 175 P . nigrum accessions from eight main black pepper growing regions in Sri Lanka. The sequencing effort resulted in 1,976 million raw reads, averaging 11.3 million reads per accession, revealing 150,356 high-quality single nucleotide polymorphisms (SNPs) distributed across 26 chromosomes. Population structure analysis revealed two subpopulations ( K = 2): a dominant group consisting of 152 accessions sourced from both home gardens and large-scale cultivations, and a smaller group comprising 23 accessions exclusively from native collections in home gardens. This clustering was further supported by principal component analysis, with the first two principal components explaining 35.2 and 12.1% of the total variation. Genetic diversity analysis indicated substantial gene flow ( Nm = 342.21) and a low fixation index ( F ST = 0.00073) between the two subpopulations, with no clear genetic differentiation among accessions from different agro-climatic regions. These findings demonstrate that most current black pepper genotypes grown in Sri Lanka share a common genetic background, emphasizing the necessity to broaden the genetic base to enhance resilience to biotic and abiotic stresses. This study represents the first attempt at analyzing black pepper genetic diversity using high-resolution SNP markers, laying the foundation for future genome-wide association studies for SNP-based gene discovery and breeding.
Journal Article