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1.
J Neurosci ; 44(36)2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39103222

RESUMEN

While the influence of context on long-term memory (LTM) is well documented, its effects on the interaction between working memory (WM) and LTM remain less understood. In this study, we explored these interactions using a delayed match-to-sample task, where participants (6 males, 16 females) encountered the same target object across six consecutive trials, facilitating the transition from WM to LTM. During half of these target repetitions, the background color changed. We measured the WM storage of the target using the contralateral delay activity in electroencephalography. Our results reveal that task-irrelevant context changes trigger the reactivation of long-term memories in WM. This reactivation may be attributed to content-context binding in WM and hippocampal pattern separation.


Asunto(s)
Electroencefalografía , Memoria a Largo Plazo , Memoria a Corto Plazo , Humanos , Masculino , Femenino , Adulto Joven , Memoria a Corto Plazo/fisiología , Adulto , Memoria a Largo Plazo/fisiología , Hipocampo/fisiología
2.
J Am Chem Soc ; 146(7): 4582-4591, 2024 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-38330910

RESUMEN

The effort to modulate challenging protein targets has stimulated interest in ligands that are larger and more complex than typical small-molecule drugs. While combinatorial techniques such as mRNA display routinely produce high-affinity macrocyclic peptides against classically undruggable targets, poor membrane permeability has limited their use toward primarily extracellular targets. Understanding the passive membrane permeability of macrocyclic peptides would, in principle, improve our ability to design libraries whose leads can be more readily optimized against intracellular targets. Here, we investigate the permeabilities of over 200 macrocyclic 10-mers using the thioether cyclization motif commonly found in mRNA display macrocycle libraries. We identified the optimal lipophilicity range for achieving permeability in thioether-cyclized 10-mer cyclic peptide-peptoid hybrid scaffolds and showed that permeability could be maintained upon extensive permutation in the backbone. In one case, changing a single amino acid from d-Pro to d-NMe-Ala, representing the loss of a single methylene group in the side chain, resulted in a highly permeable scaffold in which the low-dielectric conformation shifted from the canonical cross-beta geometry of the parent compounds into a novel saddle-shaped fold in which all four backbone NH groups were sequestered from the solvent. This work provides an example by which pre-existing physicochemical knowledge of a scaffold can benefit the design of macrocyclic peptide mRNA display libraries, pointing toward an approach for biasing libraries toward permeability by design. Moreover, the compounds described herein are a further demonstration that geometrically diverse, highly permeable scaffolds exist well beyond conventional drug-like chemical space.


Asunto(s)
Péptidos Cíclicos , Péptidos , Péptidos/química , Péptidos Cíclicos/química , Biblioteca de Péptidos , Permeabilidad , ARN Mensajero , Sulfuros
3.
Cereb Cortex ; 33(12): 7608-7618, 2023 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-37005059

RESUMEN

Our visual environment is relatively stable over time. An optimized visual system could capitalize on this by devoting less representational resources to objects that are physically present. The vividness of subjective experience, however, suggests that externally available (perceived) information is more strongly represented in neural signals than memorized information. To distinguish between these opposing predictions, we use EEG multivariate pattern analysis to quantify the representational strength of task-relevant features in anticipation of a change-detection task. Perceptual availability was manipulated between experimental blocks by either keeping the stimulus available on the screen during a 2-s delay period (perception) or removing it shortly after its initial presentation (memory). We find that task-relevant (attended) memorized features are more strongly represented than irrelevant (unattended) features. More importantly, we find that task-relevant features evoke significantly weaker representations when they are perceptually available compared with when they are unavailable. These findings demonstrate that, contrary to what subjective experience suggests, vividly perceived stimuli elicit weaker neural representations (in terms of detectable multivariate information) than the same stimuli maintained in visual working memory. We hypothesize that an efficient visual system spends little of its limited resources on the internal representation of information that is externally available anyway.


Asunto(s)
Memoria a Corto Plazo , Percepción Visual , Percepción Visual/fisiología , Memoria a Corto Plazo/fisiología
4.
J Emerg Nurs ; 50(4): 523-536, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38573297

RESUMEN

INTRODUCTION: Charge nurses are shift leaders whose role includes managing nursing resources and facilitating appropriate patient care; in emergency departments, the charge nurse role requires both clinical and leadership skills to facilitate the flow of patients, while ensuring patient and staff safety. Literature on orientation and specific training is notably sparse. This study aimed to evaluate the content and process of core competency training and identify evaluation and implementation strategies necessary to improve charge nurse performance in United States emergency departments. METHODS: A modified Delphi technique was used in phase 1 and a qualitative content analysis method was used in phase 2 to address specific aims of the study. RESULTS: In total, 427 emergency nurse managers, directors, educators, and charge nurses responded to the initial survey to identify elements, teaching modalities, and evaluative processes; 22 participated in 1 of 2 focus groups to provide further information about the pedagogical approaches to teaching emergency charge nurse competencies. The top 5 competencies were identified as patient flow management, communication, situational awareness, clinical decision making, and nurse-patient assignment, with understanding that each competency overlapped significantly with the others. Low-fidelity simulation and gamification were identified as a preferred method of both training and evaluation. DISCUSSION: These findings have the potential to support a standardized approach to emergency charge nurse training and evaluation focusing on communication skills, clinical decision making, and situational awareness to facilitate safe and effective nurse-patient assignment and emergency department throughput.


Asunto(s)
Competencia Clínica , Técnica Delphi , Enfermería de Urgencia , Servicio de Urgencia en Hospital , Humanos , Enfermería de Urgencia/educación , Estados Unidos , Encuestas y Cuestionarios , Supervisión de Enfermería , Grupos Focales
5.
Dev Biol ; 483: 39-57, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34990731

RESUMEN

Neural crest (NC) cells are a dynamic population of embryonic stem cells that create various adult tissues in vertebrate species including craniofacial bone and cartilage and the peripheral and enteric nervous systems. NC development is thought to be a conserved and complex process that is controlled by a tightly-regulated gene regulatory network (GRN) of morphogens, transcription factors, and cell adhesion proteins. While multiple studies have characterized the expression of several GRN factors in single species, a comprehensive protein analysis that directly compares expression across development is lacking. To address this lack in information, we used three closely related avian models, Gallus gallus (chicken), Coturnix japonica (Japanese quail), and Pavo cristatus (Indian peafowl), to compare the localization and timing of four GRN transcription factors, PAX7, SNAI2, SOX9, and SOX10, from the onset of neurulation to migration. While the spatial expression of these factors is largely conserved, we find that quail NC cells express SNAI2, SOX9, and SOX10 proteins at the equivalent of earlier developmental stages than chick and peafowl. In addition, quail NC cells migrate farther and more rapidly than the larger organisms. These data suggest that despite a conservation of NC GRN players, differences in the timing of NC development between species remain a significant frontier to be explored with functional studies.


Asunto(s)
Proteínas Aviares/genética , Proteínas Aviares/metabolismo , Movimiento Celular/genética , Pollos/genética , Coturnix/embriología , Coturnix/genética , Regulación del Desarrollo de la Expresión Génica , Cresta Neural/metabolismo , Neurulación/genética , Animales , Embrión de Pollo , Pollos/metabolismo , Coturnix/metabolismo , Femenino , Redes Reguladoras de Genes , Cresta Neural/embriología , Tubo Neural/embriología , Tubo Neural/metabolismo , Oviparidad/genética , Factor de Transcripción PAX7/genética , Factor de Transcripción PAX7/metabolismo , Factor de Transcripción SOX9/genética , Factor de Transcripción SOX9/metabolismo , Factores de Transcripción de la Familia Snail/genética , Factores de Transcripción de la Familia Snail/metabolismo
6.
Opt Express ; 31(24): 40366-40379, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-38041340

RESUMEN

Structural colors in nature are frequently produced by the ordered arrangement of nanoparticles. Interesting examples include reptiles and birds utilizing lattice-like formation of nanoparticles to produce a variety of colors. A famous example is the panther chameleon which is even able to change its color by actively varying the distance between guanine nanocrystals in its skin. Here, we demonstrate that the application of rigorous electromagnetic methods is important to determine the actual optical response of such biological systems. By applying the Korringa-Kohn-Rostoker (KKR) method we calculate the efficiencies of the reflected diffraction orders that can be viewed from directions other than the specular. Our results reveal that important characteristics of the reflectance spectra, especially within the ultraviolet (UV) and short visible wavelengths region, cannot be predicted by approximate models like the often-applied Maxwell-Garnett approach. Additionally, we show that the KKR method can be employed for the design of multi-layer structures with a desired optical response in the UV regime.

7.
Nature ; 548(7665): 87-91, 2017 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-28746312

RESUMEN

Hundreds of thousands of human genomes are now being sequenced to characterize genetic variation and use this information to augment association mapping studies of complex disorders and other phenotypic traits. Genetic variation is identified mainly by mapping short reads to the reference genome or by performing local assembly. However, these approaches are biased against discovery of structural variants and variation in the more complex parts of the genome. Hence, large-scale de novo assembly is needed. Here we show that it is possible to construct excellent de novo assemblies from high-coverage sequencing with mate-pair libraries extending up to 20 kilobases. We report de novo assemblies of 150 individuals (50 trios) from the GenomeDenmark project. The quality of these assemblies is similar to those obtained using the more expensive long-read technology. We use the assemblies to identify a rich set of structural variants including many novel insertions and demonstrate how this variant catalogue enables further deciphering of known association mapping signals. We leverage the assemblies to provide 100 completely resolved major histocompatibility complex haplotypes and to resolve major parts of the Y chromosome. Our study provides a regional reference genome that we expect will improve the power of future association mapping studies and hence pave the way for precision medicine initiatives, which now are being launched in many countries including Denmark.


Asunto(s)
Variación Genética/genética , Genética de Población/normas , Genoma Humano/genética , Genómica/normas , Análisis de Secuencia de ADN/normas , Adulto , Alelos , Niño , Cromosomas Humanos Y/genética , Dinamarca , Femenino , Haplotipos/genética , Humanos , Complejo Mayor de Histocompatibilidad/genética , Masculino , Edad Materna , Tasa de Mutación , Edad Paterna , Mutación Puntual/genética , Estándares de Referencia
8.
Proc Natl Acad Sci U S A ; 117(16): 9074-9081, 2020 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-32265284

RESUMEN

Malaria caused by the apicomplexan parasite Plasmodium falciparum has served as a strong evolutionary force throughout human history, selecting for red blood cell polymorphisms that confer innate protection against severe disease. Recently, gain-of-function mutations in the mechanosensitive ion channel PIEZO1 were shown to ameliorate Plasmodium parasite growth, blood-brain barrier dysfunction, and mortality in a mouse model of malaria. In humans, the gain-of-function allele PIEZO1 E756del is highly prevalent and enriched in Africans, raising the possibility that it is under positive selection due to malaria. Here we used a case-control study design to test for an association between PIEZO1 E756del and malaria severity among children in Gabon. We found that the E756del variant is strongly associated with protection against severe malaria in heterozygotes. In subjects with sickle cell trait, heterozygosity for PIEZO1 E756del did not confer additive protection and homozygosity was associated with an elevated risk of severe disease, suggesting an epistatic relationship between hemoglobin S and PIEZO1 E756del. Using donor blood samples, we show that red cells heterozygous for PIEZO1 E756del are not dehydrated and can support the intracellular growth of P. falciparum similar to wild-type cells. However, surface expression of the P. falciparum virulence protein PfEMP-1 was significantly reduced in infected cells heterozygous for PIEZO1 756del, a phenomenon that has been observed with other protective polymorphisms, such as hemoglobin C. Our findings demonstrate that PIEZO1 is an important innate determinant of malaria susceptibility in humans and suggest that the mechanism of protection may be related to impaired export of P. falciparum virulence proteins.


Asunto(s)
Resistencia a la Enfermedad/genética , Canales Iónicos/genética , Malaria Falciparum/genética , Plasmodium falciparum/aislamiento & purificación , Rasgo Drepanocítico/genética , Animales , Estudios de Casos y Controles , Niño , Preescolar , Análisis Mutacional de ADN , Eritrocitos/metabolismo , Eritrocitos/parasitología , Femenino , Gabón , Mutación con Ganancia de Función , Humanos , Lactante , Malaria Falciparum/sangre , Malaria Falciparum/parasitología , Masculino , Polimorfismo Genético , Factores Protectores , Proteínas Protozoarias/aislamiento & purificación , Proteínas Protozoarias/metabolismo
9.
J Emerg Nurs ; 49(3): 431-440, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36180265

RESUMEN

INTRODUCTION: Patient/visitor violence and aggression (V&A) in the emergency department occurs daily. Few interventions exist to decrease V&A. Research describing prevalence, severity, and perceived safety among ED clinicians is limited. METHODS: A descriptive survey explored V&A against ED clinicians in one urban emergency department. A sample of nurses, ED technicians, physicians and advanced practice providers participated. Participants completed a demographic survey, Personal Workplace Safety Instrument for Emergency Nurses (PWSI-EN), and ENA V&A frequency checklist. Analysis of Variance (ANOVA) for unadjusted and Analysis of Covariance (ANCOVA) for adjusted associations were used to assess differences in the PWSI-EN survey composite score and "feeling safe in the ED" among ED roles. ANCOVA was adjusted for potential confounders: sex, race, years working in emergency department, and shift worked. RESULTS: Sixty-five (46.4%) of the 140 ED clinicians returned surveys, which were almost evenly distributed between ED clinician roles and sex. Mean age was 37.2 (range: 21-64) years. All (100%) nurses and providers reported being verbally abused. More nurses reported physical violence (n = 21, 87.5%) than providers (n = 7, 36.8%) and ED technicians (n = 11, 55%). Nurses and ED technicians reported experiencing greater prevalence of physical violence than providers (P < .05). Nurses (mean 3.29, range 2.95 to 3.63) were more fearful for their personal safety than ED technicians (mean 3.88, range 3.48 to 4.28) (P < .03). DISCUSSION: V&A are common creating a fearful environment. However, little research regarding clinician perceptions exists. Our study aids in identifying areas for clinician-targeted strategies to prevent ED V&A.


Asunto(s)
Violencia , Violencia Laboral , Humanos , Adulto , Agresión , Encuestas y Cuestionarios , Administración de la Seguridad , Servicio de Urgencia en Hospital , Violencia Laboral/prevención & control
10.
J Proteome Res ; 21(11): 2703-2714, 2022 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-36099490

RESUMEN

The synthesis of new proteins and the degradation of old proteins in vivo can be quantified in serial samples using metabolic isotope labeling to measure turnover. Because serial biopsies in humans are impractical, we set out to develop a method to calculate the turnover rates of proteins from single human biopsies. This method involved a new metabolic labeling approach and adjustments to the calculations used in previous work to calculate protein turnover. We demonstrate that using a nonequilibrium isotope enrichment strategy avoids the time dependent bias caused by variable lag in label delivery to different tissues observed in traditional metabolic labeling methods. Turnover rates are consistent for the same subject in biopsies from different labeling periods, and turnover rates calculated in this study are consistent with previously reported values. We also demonstrate that by measuring protein turnover we can determine where proteins are synthesized. In human subjects a significant difference in turnover rates differentiated proteins synthesized in the salivary glands versus those imported from the serum. We also provide a data analysis tool, DeuteRater-H, to calculate protein turnover using this nonequilibrium metabolic 2H2O method.


Asunto(s)
Isótopos , Proteínas , Humanos , Marcaje Isotópico/métodos , Proteínas/metabolismo , Proteolisis , Biopsia/métodos
11.
J Biol Chem ; 296: 100805, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34022220

RESUMEN

After activation of G protein-coupled receptors, G protein ßγ dimers may translocate from the plasma membrane to the Golgi apparatus (GA). We recently report that this translocation activates extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) via PI3Kγ; however, how Gßγ-PI3Kγ activates the ERK1/2 pathway is unclear. Here, we demonstrate that chemokine receptor CXCR4 activates ADP-ribosylation factor 1 (ARF1), a small GTPase important for vesicle-mediated membrane trafficking. This activation is blocked by CRISPR-Cas9-mediated knockout of the GA-translocating Gγ9 subunit. Inducible targeting of different Gßγ dimers to the GA can directly activate ARF1. CXCR4 activation and constitutive Gßγ recruitment to the GA also enhance ARF1 translocation to the GA. We further demonstrate that pharmacological inhibition and CRISPR-Cas9-mediated knockout of PI3Kγ markedly inhibit CXCR4-mediated and Gßγ translocation-mediated ARF1 activation. We also show that depletion of ARF1 by siRNA and CRISPR-Cas9 and inhibition of GA-localized ARF1 activation abolish ERK1/2 activation by CXCR4 and Gßγ translocation to the GA and suppress prostate cancer PC3 cell migration and invasion. Collectively, our data reveal a novel function for Gßγ translocation to the GA to activate ARF1 and identify GA-localized ARF1 as an effector acting downstream of Gßγ-PI3Kγ to spatiotemporally regulate G protein-coupled receptor signaling to mitogen-activated protein kinases.


Asunto(s)
Factor 1 de Ribosilacion-ADP/metabolismo , Subunidades beta de la Proteína de Unión al GTP/metabolismo , Aparato de Golgi/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Factor 1 de Ribosilacion-ADP/análisis , Subunidades beta de la Proteína de Unión al GTP/análisis , Células HEK293 , Humanos , Proteínas Quinasas Activadas por Mitógenos/análisis , Células PC-3 , Multimerización de Proteína , Transporte de Proteínas , Receptores Acoplados a Proteínas G/análisis , Transducción de Señal
12.
J Cogn Neurosci ; 34(7): 1148-1163, 2022 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-35468211

RESUMEN

Visual working memory has been proven to be relatively robust against interference. However, little is known on whether such robust coding is obligatory, or can be flexibly recruited depending on its expected usefulness. To address this, participants remembered both the color and orientation of a grating. During the maintenance, we inserted a secondary color/orientation memory task, interfering with the primary task. Crucially, we varied the expectations of the type of interference by varying the probability of the two types of intervening task. Behavioral data indicate that to-be-remembered features for which interference is expected are bolstered, whereas to-be-remembered features for which no interference is expected are left vulnerable. This was further supported by fMRI data obtained from visual cortex. In conclusion, the flexibility of visual working memory allows it to strengthen memories for which it anticipates the highest risk of interference.


Asunto(s)
Memoria a Corto Plazo , Corteza Visual , Atención , Humanos , Imagen por Resonancia Magnética , Recuerdo Mental
13.
Anal Chem ; 94(4): 2032-2041, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-35041378

RESUMEN

Macrocyclic peptides (MCPs) are an emerging class of promising drug modalities that can be used to interrogate hard-to-drug ("undruggable") targets. However, their poor intestinal stability is one of the major liabilities or obstacles for oral drug delivery. We therefore investigated the metabolic stability and biotransformation of MCPs via a systematic approach and established an integrated in vitro assay strategy to facilitate MCP drug discovery, with a focus on oral delivery liabilities. A group of diverse MCPs were incubated with representative matrices, including simulated intestinal fluid with pancreatin (SIFP), human enterocytes, liver S9 fractions, liver lysosomes, plasma, and recombinant enzymes. The results revealed that the stability and biotransformation of MCPs varied, with the major metabolic pathways identified in different matrices. Under the given conditions, the selected MCPs generally showed better stability in plasma compared to that in SIFP. Our data suggest that pancreatic enzymes act as the primary metabolic barrier for the oral delivery of MCPs, mainly through hydrolysis of their backbone amide bonds. Whereas in enterocytes, multiple metabolic pathways appeared to be involved and resulted in metabolic reactions such as oxidation and reduction in addition to hydrolysis. Further studies suggested that lysosomal peptidase cathepsin B could be a major enzyme responsible for the cleavage of side-chain amide bonds in lysosomes. Collectively, we developed and implemented an integrated assay for assessing the metabolic stability and biotransformation of MCPs for compound screening in the discovery stage toward oral delivery. The proposed question-driven assay cascade can provide biotransformation insights that help to guide and facilitate lead candidate selection and optimization.


Asunto(s)
Péptido Hidrolasas , Péptidos , Biotransformación , Descubrimiento de Drogas , Humanos , Preparaciones Farmacéuticas
14.
Mol Cell Proteomics ; 19(12): 2139-2157, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33020190

RESUMEN

Trypsin is the protease of choice in bottom-up proteomics. However, its application can be limited by the amino acid composition of target proteins and the pH of the digestion solution. In this study we characterize ProAlanase, a protease from the fungus Aspergillus niger that cleaves primarily on the C-terminal side of proline and alanine residues. ProAlanase achieves high proteolytic activity and specificity when digestion is carried out at acidic pH (1.5) for relatively short (2 h) time periods. To elucidate the potential of ProAlanase in proteomics applications, we conducted a series of investigations comprising comparative multi-enzymatic profiling of a human cell line proteome, histone PTM analysis, ancient bone protein identification, phosphosite mapping and de novo sequencing of a proline-rich protein and disulfide bond mapping in mAb. The results demonstrate that ProAlanase is highly suitable for proteomics analysis of the arginine- and lysine-rich histones, enabling high sequence coverage of multiple histone family members. It also facilitates an efficient digestion of bone collagen thanks to the cleavage at the C terminus of hydroxyproline which is highly prevalent in collagen. This allows to identify complementary proteins in ProAlanase- and trypsin-digested ancient bone samples, as well as to increase sequence coverage of noncollagenous proteins. Moreover, digestion with ProAlanase improves protein sequence coverage and phosphosite localization for the proline-rich protein Notch3 intracellular domain (N3ICD). Furthermore, we achieve a nearly complete coverage of N3ICD protein by de novo sequencing using the combination of ProAlanase and tryptic peptides. Finally, we demonstrate that ProAlanase is efficient in disulfide bond mapping, showing high coverage of disulfide-containing regions in a nonreduced mAb.


Asunto(s)
Disulfuros/metabolismo , Péptido Hidrolasas/metabolismo , Proteómica , Tripsina/metabolismo , Secuencia de Aminoácidos , Animales , Femenino , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Mamuts , Paleontología , Péptido Hidrolasas/química , Fosforilación , Proteoma/metabolismo
15.
Nurs Educ Perspect ; 43(6): 343-350, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35671388

RESUMEN

AIM: The purpose of this study was to describe insights gained by academic nursing faculty after shadowing one of their new graduate nurses. BACKGROUND: Shadowing experiences have been successfully used to orient students and new nurses to the role and reality of clinical practice. However, no studies were found on the experience of faculty shadowing a new graduate. This study addressed that gap. METHOD: A case series design and methodology used both qualitative and quantitative data collection procedures. Qualitative data were derived from faculty during a debriefing session; quantitative data were obtained from a short survey completed by new graduates and faculty. RESULTS: Faculty identified challenges faced by new graduates and opportunities to modify their nursing programs by addressing patient care delivery, time management, communication, and role ambiguity in more detail. CONCLUSION: A shadowing experience for academic faculty leaders can help bridge the academic-practice gap and promote collaborative efforts to improve preparation for practice.


Asunto(s)
Educación de Postgrado en Enfermería , Humanos , Docentes de Enfermería , Estudiantes
16.
J Emerg Nurs ; 48(4): 390-405, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35660060

RESUMEN

INTRODUCTION: Charge nurses (CNs) are shift leaders who manage resources and facilitate patient care, yet CNs in EDs receive minimal training, with implications for patient safety and emergency nursing practice. The purpose of the study was to describe the experiences of emergency nurses related to training, preparation, and function of the CN role. METHODS: An explanatory sequential mixed methods design using survey data (n = 2579) and focus group data (n = 49) from both CN and staff nurse perspectives. RESULTS: Participants reported minimal training for the CN role, with divergent understandings of role, required education and experience, the need for situational awareness, and the acceptability of the CN taking on other duties. CONCLUSIONS: The ED CN is critical to the safety of both nursing environment and patient care. Nurses in this pivotal role do not receive adequate leadership orientation or formal training in the key areas of nurse patient assignment, communication, and situational awareness. Formal training in nurse-patient assignment, communication, and situational awareness are critical to appropriate patient care and maintenance of interprofessional trust necessary for successful execution of the CN role. ED nurse managers should advocate for this training.


Asunto(s)
Enfermeras Administradoras , Supervisión de Enfermería , Servicio de Urgencia en Hospital , Humanos , Liderazgo , Motivación , Rol de la Enfermera
17.
J Infect Dis ; 224(11): 1935-1944, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33893799

RESUMEN

BACKGROUND: Randomized controlled trials (RCTs) indicate that bacille Calmette-Guérin (BCG) vaccination provides broad beneficial "nonspecific" protection against infections. We investigated the effect on in-hospital mortality of providing BCG immediately upon admission to a neonatal intensive care unit (NICU), rather than BCG-at-discharge. The pretrial NICU mortality was 13% and we hypothesized that BCG would reduce mortality by 40%. METHODS: Parallel-group, open-label RCT was initiated in 2013 in Guinea-Bissau. Neonatal intensive care unit-admitted neonates were randomized 1:1 to BCG + oral polio vaccine (OPV) immediately (intervention) versus BCG + OPV at hospital discharge (control; usual practice). The trial was discontinued due to decreasing in-hospital mortality and major NICU restructuring. We assessed overall and disease-specific mortality by randomization allocation in cox proportional hazards models providing mortality rate ratios (MRRs). RESULTS: We recruited 3353 neonates, and the overall mortality was 3.1% (52 of 1676) for BCG-vaccinated neonates versus 3.3% (55 of 1677) for controls (MRR = 0.94; 0.64-1.36). For noninfectious causes of death, the MRR was 1.20 (0.70-2.07), and there tended to be fewer deaths from infections in the BCG group (N = 14) than among controls (N = 21) (MRR = 0.65; 0.33-1.28). CONCLUSIONS: Providing BCG + OPV to frail neonates was safe and might protect against fatal infection in the immediate newborn period. Deaths due to prematurity and perinatal complications were unaffected by BCG.


Asunto(s)
Vacuna BCG/administración & dosificación , Enfermedades Transmisibles/mortalidad , Poliomielitis/prevención & control , Vacunación/métodos , Vacuna BCG/efectos adversos , Femenino , Guinea Bissau/epidemiología , Mortalidad Hospitalaria , Humanos , Lactante , Mortalidad Infantil , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Masculino , Análisis de Supervivencia
18.
Angew Chem Int Ed Engl ; 61(13): e202115875, 2022 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-35068052

RESUMEN

Efficient radiative recombination is essential for perovskite luminescence, but the intrinsic radiative recombination rate as a basic material property is challenging to tailor. Here we report an interfacial chemistry strategy to dramatically increase the radiative recombination rate of perovskites. By coating aluminum oxide on the lead halide perovskite, lead-oxygen bonds are formed at the perovskite-oxide interface, producing the perovskite surface states with a large exciton binding energy and a high localized density of electronic state. The oxide-bonded perovskite exhibits a ≈500 fold enhanced photoluminescence with a ≈10 fold reduced lifetime, indicating an unprecedented ≈5000 fold increase in the radiative recombination rate. The enormously enhanced radiative recombination promises to significantly promote the perovskite optoelectronic performance.

19.
J Bacteriol ; 203(13): e0014921, 2021 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-33875545

RESUMEN

Lipoprotein diacylglyceryl transferase (Lgt) catalyzes the first step in the biogenesis of Gram-negative bacterial lipoproteins which play crucial roles in bacterial growth and pathogenesis. We demonstrate that Lgt depletion in a clinical uropathogenic Escherichia coli strain leads to permeabilization of the outer membrane and increased sensitivity to serum killing and antibiotics. Importantly, we identify G2824 as the first-described Lgt inhibitor that potently inhibits Lgt biochemical activity in vitro and is bactericidal against wild-type Acinetobacter baumannii and E. coli strains. While deletion of a gene encoding a major outer membrane lipoprotein, lpp, leads to rescue of bacterial growth after genetic depletion or pharmacologic inhibition of the downstream type II signal peptidase, LspA, no such rescue of growth is detected after Lgt depletion or treatment with G2824. Inhibition of Lgt does not lead to significant accumulation of peptidoglycan-linked Lpp in the inner membrane. Our data validate Lgt as a novel antibacterial target and suggest that, unlike downstream steps in lipoprotein biosynthesis and transport, inhibition of Lgt may not be sensitive to one of the most common resistance mechanisms that invalidate inhibitors of bacterial lipoprotein biosynthesis and transport. IMPORTANCE As the emerging threat of multidrug-resistant (MDR) bacteria continues to increase, no new classes of antibiotics have been discovered in the last 50 years. While previous attempts to inhibit the lipoprotein biosynthetic (LspA) or transport (LolCDE) pathways have been made, most efforts have been hindered by the emergence of a common mechanism leading to resistance, namely, the deletion of the gene encoding a major Gram-negative outer membrane lipoprotein lpp. Our unexpected finding that inhibition of Lgt is not susceptible to lpp deletion-mediated resistance uncovers the complexity of bacterial lipoprotein biogenesis and the corresponding enzymes involved in this essential outer membrane biogenesis pathway and potentially points to new antibacterial targets in this pathway.


Asunto(s)
Escherichia coli/metabolismo , Lipoproteínas/metabolismo , Transferasas/metabolismo , Animales , Antibacterianos/farmacología , Ácido Aspártico Endopeptidasas , Proteínas Bacterianas , Escherichia coli/genética , Femenino , Eliminación de Gen , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Ratones , Peptidoglicano/metabolismo , Transferasas/química , Transferasas/genética , Escherichia coli Uropatógena/genética , Escherichia coli Uropatógena/metabolismo
20.
Biochemistry ; 60(27): 2206-2220, 2021 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-34180241

RESUMEN

The hyperthermophilic bacterium Caldicellulosiruptor kristjansonii encodes an unusual enzyme, CkXyn10C-GE15A, which incorporates two catalytic domains, a xylanase and a glucuronoyl esterase, and five carbohydrate-binding modules (CBMs) from families 9 and 22. The xylanase and glucuronoyl esterase catalytic domains were recently biochemically characterized, as was the ability of the individual CBMs to bind insoluble polysaccharides. Here, we further probed the abilities of the different CBMs from CkXyn10C-GE15A to bind to soluble poly- and oligosaccharides using affinity gel electrophoresis, isothermal titration calorimetry, and differential scanning fluorimetry. The results revealed additional binding properties of the proteins compared to the former studies on insoluble polysaccharides. Collectively, the results show that all five CBMs have their own distinct binding preferences and appear to complement each other and the catalytic domains in targeting complex cell wall polysaccharides. Additionally, through renewed efforts, we have achieved partial structural characterization of this complex multidomain protein. We have determined the structures of the third CBM9 domain (CBM9.3) and the glucuronoyl esterase (GE15A) by X-ray crystallography. CBM9.3 is the second CBM9 structure determined to date and was shown to bind oligosaccharide ligands at the same site but in a different binding mode compared to that of the previously determined CBM9 structure from Thermotoga maritima. GE15A represents a unique intermediate between reported fungal and bacterial glucuronoyl esterase structures as it lacks two inserted loop regions typical of bacterial enzymes and a third loop has an atypical structure. We also report small-angle X-ray scattering measurements of the N-terminal CBM22.1-CBM22.2-Xyn10C construct, indicating a compact arrangement at room temperature.


Asunto(s)
Proteínas Bacterianas/química , Caldicellulosiruptor/enzimología , Esterasas/química , Xilosidasas/química , Proteínas Bacterianas/metabolismo , Sitios de Unión , Caldicellulosiruptor/química , Caldicellulosiruptor/metabolismo , Cristalografía por Rayos X , Estabilidad de Enzimas , Esterasas/metabolismo , Modelos Moleculares , Oligosacáridos/metabolismo , Polisacáridos/metabolismo , Conformación Proteica , Temperatura , Xilosidasas/metabolismo
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