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1.
Cell ; 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38889727

RESUMEN

How evolution at the cellular level potentiates macroevolutionary change is central to understanding biological diversification. The >66,000 rove beetle species (Staphylinidae) form the largest metazoan family. Combining genomic and cell type transcriptomic insights spanning the largest clade, Aleocharinae, we retrace evolution of two cell types comprising a defensive gland-a putative catalyst behind staphylinid megadiversity. We identify molecular evolutionary steps leading to benzoquinone production by one cell type via a mechanism convergent with plant toxin release systems, and synthesis by the second cell type of a solvent that weaponizes the total secretion. This cooperative system has been conserved since the Early Cretaceous as Aleocharinae radiated into tens of thousands of lineages. Reprogramming each cell type yielded biochemical novelties enabling ecological specialization-most dramatically in symbionts that infiltrate social insect colonies via host-manipulating secretions. Our findings uncover cell type evolutionary processes underlying the origin and evolvability of a beetle chemical innovation.

2.
Cell ; 184(25): 6138-6156.e28, 2021 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-34890552

RESUMEN

How the functions of multicellular organs emerge from the underlying evolution of cell types is poorly understood. We deconstructed evolution of an organ novelty: a rove beetle gland that secretes a defensive cocktail. We show how gland function arose via assembly of two cell types that manufacture distinct compounds. One cell type, comprising a chemical reservoir within the abdomen, produces alkane and ester compounds. We demonstrate that this cell type is a hybrid of cuticle cells and ancient pheromone and adipocyte-like cells, executing its function via a mosaic of enzymes from each parental cell type. The second cell type synthesizes benzoquinones using a chimera of conserved cellular energy and cuticle formation pathways. We show that evolution of each cell type was shaped by coevolution between the two cell types, yielding a potent secretion that confers adaptive value. Our findings illustrate how cooperation between cell types arises, generating new, organ-level behaviors.


Asunto(s)
Benzoquinonas/metabolismo , Escarabajos/metabolismo , Drosophila melanogaster/metabolismo , Feromonas/metabolismo , Animales , Evolución Biológica , Vías Biosintéticas
4.
Proc Natl Acad Sci U S A ; 118(36)2021 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-34426523

RESUMEN

Granular excavation is the removal of solid, discrete particles from a structure composed of these objects. Efficiently predicting the stability of an excavation during particle removal is an unsolved and highly nonlinear problem, as the movement of each grain is coupled to its neighbors. Despite this, insects such as ants have evolved to be astonishingly proficient excavators, successfully removing grains such that their tunnels are stable. Currently, it is unclear how ants use their limited information about the environment to construct lasting tunnels. We attempt to unearth the ants' tunneling algorithm by taking three-dimensional (3D) X-ray computed tomographic imaging (XRCT), in real time, of Pogonomyrmex ant tunnel construction. By capturing the location and shape of each grain in the domain, we characterize the relationship between particle properties and ant decision-making within an accurate, virtual recreation of the experiment. We discover that intergranular forces decrease significantly around ant tunnels due to arches forming within the soil. Due to this force relaxation, any grain the ants pick from the tunnel surface will likely be under low stress. Thus, ants avoid removing grains compressed under high forces without needing to be aware of the force network in the surrounding material. Even more, such arches shield tunnels from high forces, providing tunnel robustness. Finally, we observe that ants tend to dig piecewise linearly downward. These results are a step toward understanding granular tunnel stability in heterogeneous 3D systems. We expect that such findings may be leveraged for robotic excavation.

5.
Adv Skin Wound Care ; 37(7): 387-391, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38899821

RESUMEN

ABSTRACT: Intravenous plasminogen replacement therapy for patients with plasminogen deficiency type 1 (hypoplasminogenemia) was recently approved for marketing in the US. In this case report, the authors describe a 33-year-old man with hypoplasminogenemia who developed nonhealing postsurgical wounds following trauma to his right hand despite receiving standard treatment for 4 months. The patient was enrolled in a compassionate-use protocol with intravenous plasminogen replacement therapy and experienced prompt resolution of surgical wounds. He was the first human patient to receive replacement therapy with plasminogen, human-tvmh in the US and first to demonstrate cutaneous wound healing in addition to resolution of ligneous lesions attributable to plasminogen deficiency type 1.


Asunto(s)
Plasminógeno , Cicatrización de Heridas , Humanos , Masculino , Adulto , Cicatrización de Heridas/efectos de los fármacos , Plasminógeno/deficiencia , Plasminógeno/uso terapéutico , Administración Intravenosa , Resultado del Tratamiento , Traumatismos de la Mano/complicaciones , Traumatismos de la Mano/cirugía , Herida Quirúrgica/tratamiento farmacológico , Herida Quirúrgica/complicaciones , Conjuntivitis , Enfermedades Cutáneas Genéticas
6.
Haemophilia ; 29(6): 1556-1564, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37674358

RESUMEN

AIM: An open-label phase 2/3 study of plasminogen, human-tvmh administered intravenously in paediatric and adult subjects with type 1 plasminogen deficiency was conducted. Interim data was previously reported. The final data on 15 subjects who completed the study up to a maximum of 124 weeks are reported here. METHODS: The primary objectives were to evaluate efficacy of plasminogen replacement therapy on clinically evident or visible lesions during 48 weeks of dosing and to achieve an increase in trough plasminogen activity levels by at least an absolute 10% above baseline during 12 weeks of treatment. RESULTS: The primary efficacy endpoint was achieved, as 100% of subjects (n = 11) with visible and assessable non-visible lesions at baseline demonstrated ≥ 50% improvement after 48 weeks of study drug treatment with plasminogen, human-tvmh. All subjects achieved the targeted ≥ 10% increase in trough plasminogen activity above baseline through Week 12. Plasminogen, human-tvmh at a dose of 6.6 mg/kg administered every 2-5 days for 48 weeks and every 1-7 days for up to 124 weeks was well tolerated. CONCLUSION: This study provides additional evidence regarding the long-term safety and clinical utility of replacement therapy with human plasminogen for the treatment of children and adults with type 1 plasminogen deficiency. Plasminogen, human-tvmh received marketing approval on June 4, 2021. This trial was registered at www. CLINICALTRIALS: gov as #NCT02690714.


Asunto(s)
Plasminógeno , Humanos , Niño , Adulto , Resultado del Tratamiento
7.
Proc Natl Acad Sci U S A ; 117(50): 31935-31944, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-33257577

RESUMEN

The stereotyped dimensions of animal bodies and their component parts result from tight constraints on growth. Yet, the mechanisms that stop growth when organs reach the right size are unknown. Growth of the Drosophila wing-a classic paradigm-is governed by two morphogens, Decapentaplegic (Dpp, a BMP) and Wingless (Wg, a Wnt). Wing growth during larval life ceases when the primordium attains full size, concomitant with the larval-to-pupal molt orchestrated by the steroid hormone ecdysone. Here, we block the molt by genetically dampening ecdysone production, creating an experimental paradigm in which the wing stops growing at the correct size while the larva continues to feed and gain body mass. Under these conditions, we show that wing growth is limited by the ranges of Dpp and Wg, and by ecdysone, which regulates the cellular response to their signaling activities. Further, we present evidence that growth terminates because of the loss of two distinct modes of morphogen action: 1) maintenance of growth within the wing proper and 2) induced growth of surrounding "pre-wing" cells and their recruitment into the wing. Our results provide a precedent for the control of organ size by morphogen range and the hormonal gating of morphogen action.


Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crecimiento & desarrollo , Ecdisona/metabolismo , Alas de Animales/crecimiento & desarrollo , Proteína Wnt1/metabolismo , Animales , Animales Modificados Genéticamente , Drosophila melanogaster/citología , Drosophila melanogaster/genética , Femenino , Regulación del Desarrollo de la Expresión Génica , Larva/citología , Larva/genética , Larva/crecimiento & desarrollo , Masculino , Tamaño de los Órganos/genética , Alas de Animales/citología
8.
J Am Chem Soc ; 143(29): 11007-11018, 2021 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-34192463

RESUMEN

Novel p-type semiconducting polymers that can facilitate ion penetration, and operate in accumulation mode are much desired in bioelectronics. Glycol side chains have proven to be an efficient method to increase bulk electrochemical doping and optimize aqueous swelling. One early polymer which exemplifies these design approaches was p(g2T-TT), employing a bithiophene-co-thienothiophene backbone with glycol side chains in the 3,3' positions of the bithiophene repeat unit. In this paper, the analogous regioisomeric polymer, namely pgBTTT, was synthesized by relocating the glycol side chains position on the bithiophene unit of p(g2T-TT) from the 3,3' to the 4,4' positions and compared with the original p(g2T-TT). By changing the regio-positioning of the side chains, the planarizing effects of the S-O interactions were redistributed along the backbone, and the influence on the polymer's microstructure organization was investigated using grazing-incidence wide-angle X-ray scattering (GIWAXS) measurements. The newly designed pgBTTT exhibited lower backbone disorder, closer π-stacking, and higher scattering intensity in both the in-plane and out-of-plane GIWAXS measurements. The effect of the improved planarity of pgBTTT manifested as higher hole mobility (µ) of 3.44 ± 0.13 cm2 V-1 s-1. Scanning tunneling microscopy (STM) was in agreement with the GIWAXS measurements and demonstrated, for the first time, that glycol side chains can also facilitate intermolecular interdigitation analogous to that of pBTTT. Electrochemical quartz crystal microbalance with dissipation of energy (eQCM-D) measurements revealed that pgBTTT maintains a more rigid structure than p(g2T-TT) during doping, minimizing molecular packing disruption and maintaining higher hole mobility in operation mode.


Asunto(s)
Técnicas Electroquímicas , Etilenos/química , Glicoles/química , Polímeros/síntesis química , Tiofenos/síntesis química , Conformación Molecular , Polímeros/química , Estereoisomerismo , Tiofenos/química
9.
Phys Chem Chem Phys ; 23(2): 1062-1071, 2021 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-33346285

RESUMEN

This study is the first report on liquid water and ice imaging conducted at a pulsed spallation neutron source facility. Neutron imaging can be utilised to visualise the water distribution inside polymer electrolyte fuel cells (PEFCs). Particularly, energy-resolved neutron imaging is a methodology capable of distinguishing between liquid water and ice, and is effective for investigating ice formation in PEFCs operating in a subfreezing environment. The distinction principle is based on the fact that the cross sections of liquid water and ice differ from each other at low neutron energies. In order to quantitatively observe transient freezing and thawing phenomena in a multiphase mixture (gas/liquid/solid) within real PEFCs with high spatial resolution, a pulsed neutron beam with both high intensity and wide energy range is most appropriate. In the validation study of the present work, we used water sealed in narrow capillary tubes to simulate the flow channels of a PEFC, and a pulsed neutron beam was applied to distinguish ice, liquid water and super-cooled water, and to clarify freezing and thawing phenomena of the water within the capillary tubes. Moreover, we have enabled the observation of liquid water/ice distributions in a large field of view (300 mm × 300 mm) by manufacturing a sub-zero environment chamber that can be cooled down to -30 °C, as a step towards in situ visualisation of full-size fuel cells.

10.
Blood ; 131(12): 1301-1310, 2018 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-29321155

RESUMEN

Congenital plasminogen deficiency is caused by mutations in PLG, the gene coding for production of the zymogen plasminogen, and is an ultrarare disorder associated with abnormal accumulation or growth of fibrin-rich pseudomembranous lesions on mucous membranes. Left untreated, these lesions may impair organ function and impact quality of life. Plasminogen replacement therapy should provide an effective treatment of the manifestations of congenital plasminogen deficiency. An open-label phase 2/3 study of human Glu-plasminogen administered IV at 6.6 mg/kg every 2 to 4 days in 15 patients with congenital plasminogen deficiency is ongoing. Reported here are data on 14 patients who completed at least 12 weeks of treatment. The primary end point was an increase in trough plasminogen activity levels by at least an absolute 10% above baseline. The secondary end point was clinical success, defined as ≥50% improvement in lesion number/size or functionality impact from baseline. All patients achieved at least an absolute 10% increase in trough plasminogen activity above baseline. Clinical success was observed in all patients with clinically visible (conjunctiva and gingiva), nonvisible (nasopharynx, bronchus, colon, kidney, cervix, and vagina), and wound-healing manifestations of the disease. Therapeutic effects were rapid, as all but 2 lesions resolved or improved after 4 weeks of treatment. Human Glu-plasminogen was well tolerated in both children and adults. This study provides critical first evidence of the clinical utility of ongoing replacement therapy with human Glu-plasminogen for the treatment of children and adults with congenital plasminogen deficiency. This trial was registered at www.clinicaltrials.gov as #NCT02690714.


Asunto(s)
Trastornos de la Coagulación Sanguínea Heredados , Plasminógeno , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Trastornos de la Coagulación Sanguínea Heredados/sangre , Trastornos de la Coagulación Sanguínea Heredados/tratamiento farmacológico , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Plasminógeno/administración & dosificación , Plasminógeno/deficiencia , Plasminógeno/farmacocinética
11.
J Exp Biol ; 223(Pt Suppl 1)2020 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-32034048

RESUMEN

Across the Metazoa, the emergence of new ecological interactions has been enabled by the repeated evolution of exocrine glands. Specialized glands have arisen recurrently and with great frequency, even in single genera or species, transforming how animals interact with their environment through trophic resource exploitation, pheromonal communication, chemical defense and parental care. The widespread convergent evolution of animal glands implies that exocrine secretory cells are a hotspot of metazoan cell type innovation. Each evolutionary origin of a novel gland involves a process of 'gland cell type assembly': the stitching together of unique biosynthesis pathways; coordinated changes in secretory systems to enable efficient chemical release; and transcriptional deployment of these machineries into cells constituting the gland. This molecular evolutionary process influences what types of compound a given species is capable of secreting, and, consequently, the kinds of ecological interactions that species can display. Here, we discuss what is known about the evolutionary assembly of gland cell types and propose a framework for how it may happen. We posit the existence of 'terminal selector' transcription factors that program gland function via regulatory recruitment of biosynthetic enzymes and secretory proteins. We suggest ancestral enzymes are initially co-opted into the novel gland, fostering pleiotropic conflict that drives enzyme duplication. This process has yielded the observed pattern of modular, gland-specific biosynthesis pathways optimized for manufacturing specific secretions. We anticipate that single-cell technologies and gene editing methods applicable in diverse species will transform the study of animal chemical interactions, revealing how gland cell types are assembled and functionally configured at a molecular level.


Asunto(s)
Evolución Molecular , Glándulas Exocrinas , Animales , Secreciones Corporales , Feromonas
12.
Eur Respir J ; 53(3)2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30578394

RESUMEN

PBI-4050 is a novel orally active small-molecule compound with demonstrated anti-fibrotic activity in several models of fibrosis, including lung fibrosis. We present results from our first clinical study of PBI-4050 in patients with idiopathic pulmonary fibrosis (IPF).This 12-week open-label study explored the safety, efficacy and pharmacokinetics of daily oral doses of 800 mg PBI-4050 alone and in combination with nintedanib or pirfenidone in patients with predominantly mild or moderate IPF. Nine patients received PBI-4050 alone, 16 patients received PBI-4050 with nintedanib and 16 patients received PBI-4050 with pirfenidone.PBI-4050 alone or in combination with nintedanib or pirfenidone was well tolerated. Pharmacokinetic profiles for PBI-4050 were similar in the PBI-4050 alone and PBI-4050+nintedanib groups but reduced in the PBI-4050+pirfenidone group, suggesting a drug-drug interaction. There were no significant changes in forced vital capacity (FVC), either in % predicted or mL, from baseline to week 12 for PBI-4050 alone or PBI-4050+nintedanib. In contrast, a statistically significant reduction (p<0.024) in FVC % pred was seen for PBI-4050+pirfenidone after 12 weeks.There were no safety concerns with PBI-4050 alone or in combination with nintedanib or pirfenidone in IPF patients. The stability of FVC between baseline and week 12 looked encouraging for PBI-4050 alone and in combination with nintedanib.


Asunto(s)
Acetatos/administración & dosificación , Fibrosis Pulmonar Idiopática/tratamiento farmacológico , Acetatos/farmacocinética , Anciano , Anciano de 80 o más Años , Quimioterapia Combinada , Femenino , Humanos , Indoles/administración & dosificación , Masculino , Persona de Mediana Edad , Seguridad del Paciente , Piridonas/administración & dosificación , Resultado del Tratamiento
13.
Am J Respir Crit Care Med ; 197(1): 94-103, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-28787186

RESUMEN

RATIONALE: IL-13 is a potential therapeutic target for idiopathic pulmonary fibrosis (IPF); preclinical data suggest a role in tissue fibrosis, and expression is increased in subjects with rapidly progressing disease. OBJECTIVES: Investigate efficacy and safety of tralokinumab, a human anti-IL-13 monoclonal antibody, in subjects with mild to moderate IPF. METHODS: Subjects received tralokinumab (400 or 800 mg), or placebo, intravenously every 4 weeks for 68 weeks. The primary endpoint was change from baseline to Week 52 in percent predicted FVC in the intention-to-treat population. Exploratory analyses included assessment of clinical response in subgroups with baseline serum periostin concentration above/below median. MEASUREMENTS AND MAIN RESULTS: The study was stopped due to lack of efficacy after interim analysis. Neither tralokinumab 400 mg nor tralokinumab 800 mg met the primary endpoint; least-squares mean difference (95% confidence interval) percent predicted FVC from baseline to Week 52: -1.77 (-4.13 to 0.59) (P = 0.140) and -1.41 (-3.73 to 0.91) (P = 0.234), respectively. The primary endpoint was also not met in either treatment group in subgroups defined by periostin baseline concentration. The percentage of subjects with decline in percent predicted FVC greater than or equal to 10% at Week 52 was numerically greater for tralokinumab-treated subjects compared with placebo. The most common treatment-emergent adverse events for tralokinumab 400 mg, tralokinumab 800 mg, and placebo were cough (17.5, 30.5, 22.8%), IPF progression and exacerbation (21.1, 16.9, 22.8%), and upper respiratory tract infection (17.5, 20.3, 12.3%), respectively. CONCLUSIONS: Tralokinumab demonstrated an acceptable safety and tolerability profile but did not achieve key efficacy endpoints. Clinical trial registered with www.clinicaltrials.gov (NCT01629667).


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Fibrosis Pulmonar Idiopática/diagnóstico , Fibrosis Pulmonar Idiopática/tratamiento farmacológico , Seguridad del Paciente , Anciano , Biomarcadores/metabolismo , Moléculas de Adhesión Celular/metabolismo , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Esquema de Medicación , Humanos , Fibrosis Pulmonar Idiopática/mortalidad , Dosis Máxima Tolerada , Persona de Mediana Edad , Pronóstico , Medición de Riesgo , Índice de Severidad de la Enfermedad , Tasa de Supervivencia , Resultado del Tratamiento
14.
PLoS Biol ; 13(10): e1002274, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26474042

RESUMEN

Organ growth is controlled by patterning signals that operate locally (e.g., Wingless/Ints [Wnts], Bone Morphogenetic Proteins [BMPs], and Hedgehogs [Hhs]) and scaled by nutrient-dependent signals that act systemically (e.g., Insulin-like peptides [ILPs] transduced by the Target of Rapamycin [TOR] pathway). How cells integrate these distinct inputs to generate organs of the appropriate size and shape is largely unknown. The transcriptional coactivator Yorkie (Yki, a YES-Associated Protein, or YAP) acts downstream of patterning morphogens and other tissue-intrinsic signals to promote organ growth. Yki activity is regulated primarily by the Warts/Hippo (Wts/Hpo) tumour suppressor pathway, which impedes nuclear access of Yki by a cytoplasmic tethering mechanism. Here, we show that the TOR pathway regulates Yki by a separate and novel mechanism in the Drosophila wing. Instead of controlling Yki nuclear access, TOR signaling governs Yki action after it reaches the nucleus by allowing it to gain access to its target genes. When TOR activity is inhibited, Yki accumulates in the nucleus but is sequestered from its normal growth-promoting target genes--a phenomenon we term "nuclear seclusion." Hence, we posit that in addition to its well-known role in stimulating cellular metabolism in response to nutrients, TOR also promotes wing growth by liberating Yki from nuclear seclusion, a parallel pathway that we propose contributes to the scaling of wing size with nutrient availability.


Asunto(s)
Núcleo Celular/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Transactivadores/metabolismo , Alas de Animales/crecimiento & desarrollo , Transporte Activo de Núcleo Celular , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Animales Modificados Genéticamente , Restricción Calórica/efectos adversos , Proteínas de Drosophila/antagonistas & inhibidores , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster/citología , Drosophila melanogaster/genética , Eliminación de Gen , Regulación del Desarrollo de la Expresión Génica , Larva/citología , Larva/genética , Larva/fisiología , Proteínas Luminiscentes/química , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , MicroARNs/metabolismo , Mutación , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/química , Proteínas Nucleares/genética , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/metabolismo , Dominios y Motivos de Interacción de Proteínas , Interferencia de ARN , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/genética , Transactivadores/antagonistas & inhibidores , Transactivadores/química , Transactivadores/genética , Alas de Animales/enzimología , Alas de Animales/metabolismo , Proteínas Señalizadoras YAP
15.
Langmuir ; 33(37): 9416-9425, 2017 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-28617602

RESUMEN

Platinum is state-of-the-art for fast electron transfer whereas carbon electrodes, which have semimetal electronic character, typically exhibit slow electron-transfer kinetics. But when we turn to practical electrochemical devices, we turn to carbon. To move energy devices and electro(bio)analytical measurements to a new performance curve requires improved electron-transfer rates at carbon. We approach this challenge with electroless deposition of disordered, nanoscopic anhydrous ruthenium oxide at pyrolytic carbon prepared by thermal decomposition of benzene (RuOx@CVD-C). We assessed traditionally fast, chloride-assisted ([Fe(CN)6]3-/4-) and notoriously slow ([Fe(H2O)6]3+/2+) electron-transfer redox probes at CVD-C and RuOx@CVD-C electrodes and calculated standard heterogeneous rate constants as a function of heat treatment to crystallize the disordered RuOx domains to their rutile form. For the fast electron-transfer probe, [Fe(CN)6]3-/4-, the rate increases by 34× over CVD-C once the RuOx is calcined to form crystalline rutile RuO2. For the classically outer-sphere [Fe(H2O)6]3+/2+, electron-transfer rates increase by an even greater degree over CVD-C (55×). The standard heterogeneous rate constant for each probe approaches that observed at Pt but does so using only minimal loadings of RuOx.

16.
Langmuir ; 33(37): 9390-9397, 2017 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-28627895

RESUMEN

Electrocatalysis of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) was assessed for a series of Ni-substituted ferrites (NiyFe1-yOx, where y = 0.1 to 0.9) as expressed in porous, high-surface-area forms (ambigel and aerogel nanoarchitectures). We then correlate electrocatalytic activity with Ni:Fe stoichiometry as a function of surface area, crystallite size, and free volume. In order to ensure in-series comparisons, calcination at 350 °C/air was necessary to crystallize the respective NiyFe1-yOx nanoarchitectures, which index to the inverse spinel structure for Fe-rich materials (y ≤ 0.33), rock salt for the most Ni-rich material (y = 0.9), and biphasic for intermediate stoichiometry (0.5 ≤ y ≤ 0.67). In the intermediate Ni:Fe stoichiometric range (0.33 ≤ y ≤ 0.67), the OER current density at 390 mV increases monotonically with increasing Ni content and increasing surface area, but with different working curves for ambigels versus aerogels. At a common stoichiometry within this range, ambigels and aerogels yield comparable OER performance, but do so by expressing larger crystallite size (ambigel) versus higher surface area (aerogel). Effective OER activity can be achieved without requiring supercritical-fluid extraction as long as moderately high surface area, porous materials can be prepared. We find improved OER performance (η decreases from 390 to 373 mV) for Ni0.67Fe0.33Ox aerogel heat-treated at 300 °C/Ar, owing to an increase in crystallite size (2.7 to 4.1 nm). For the ORR, electrocatalytic activity favors Fe-rich NiyFe1-yOx materials; however, as the Ni-content increases beyond y = 0.5, a two-electron reduction pathway is still exhibited, demonstrating that bifunctional OER and ORR activity may be possible by choosing a nickel ferrite nanoarchitecture that provides high OER activity with sufficient ORR activity. Assessing the catalytic activity requires an appreciation of the multivariate interplay among Ni:Fe stoichiometry, surface area, crystallographic phase, and crystallite size.

17.
Mol Cell Biochem ; 426(1-2): 111-127, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27896594

RESUMEN

Circulatory arrest (CA) remains a major unresolved public health problem in the United States; the annual incidence of which is ~0.50 to 0.55 per 1000 population. Despite seminal advances in therapeutic approaches over the past several decades, brain injury continues to be the leading cause of morbidity and mortality after CA. In brief, CA typically results in global cerebral ischemia leading to delayed neuronal death in the hippocampal pyramidal cells as well as in the cortical layers. The dynamic changes occurring in neurons after CA are still unclear, and predicting these neurological changes in the brain still remains a difficult issue. It is hypothesized that the "no-flow" period produces a cytotoxic cascade of membrane depolarization, Ca2+ ion influx, glutamate release, acidosis, and resultant activation of lipases, nucleases, and proteases. Furthermore, during reperfusion injury, neuronal death occurs due to the generation of free radicals by interfering with the mitochondrial respiratory chain. The efficacy of many pharmacological agents for CA patients has often been disappointing, reflecting our incomplete understanding of this enigmatic disease. The primary obstacles to the development of a neuroprotective therapy in CA include uncertainties with regard to the precise cause(s) of neuronal dysfunction and what to target. In this review, we summarize our knowledge of the pathophysiology as well as specific cellular changes in brain after CA and revisit the most important neurofunctional, neuroimaging techniques, and serum biomarkers as potent predictors of neurologic outcome in CA patients.


Asunto(s)
Isquemia Encefálica , Señalización del Calcio , Circulación Cerebrovascular , Hipocampo , Potenciales de la Membrana , Células Piramidales , Animales , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/metabolismo , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/terapia , Hipocampo/química , Hipocampo/metabolismo , Hipocampo/patología , Hipocampo/fisiopatología , Humanos , Células Piramidales/metabolismo , Daño por Reperfusión/diagnóstico , Daño por Reperfusión/metabolismo , Daño por Reperfusión/fisiopatología , Daño por Reperfusión/terapia
18.
J Nurs Adm ; 47(2): 108-115, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28067679

RESUMEN

OBJECTIVE: The research objective was to determine the expectations of and satisfaction with the healthcare coach (HCC) role among hospitalists and staff RNs, as well as expectations of case managers who collaborate with them. BACKGROUND: Care transitions occur when patients move from 1 care setting or provider to another. The Centers for Medicare & Medicaid Services developed the Community-Based Care Transitions Program to address readmission, patient safety, improved quality of care, and cost savings. METHODS: A cross-sectional study measured level of satisfaction and explored qualitatively the expectations regarding the HCC role among hospitalists and staffs RNs. Case managers were surveyed regarding expectations of the HCC role. The HCCs were surveyed regarding their new role experiences. RESULTS: On a Likert scale of 1 to 5, satisfaction with the HCC role by staff nurses averaged 3 (neutral), whereas hospitalists' mean satisfaction was 4 (satisfied). From the qualitative data, 6 themes emerged among participants: personal qualities, care navigation, system perspective, collaboration/teamwork, challenges/role confusion, and future role benefits. Two additional themes were identified by the HCCs: new knowledge and helpful skill sets. CONCLUSIONS: We recommend further evaluation of the HCC role in other organizations and across care settings.


Asunto(s)
Consejo/métodos , Capacitación en Servicio/organización & administración , Equipos de Administración Institucional/organización & administración , Relaciones Interprofesionales , Innovación Organizacional , Actitud del Personal de Salud , Estudios Transversales , Humanos , Satisfacción en el Trabajo , Gestión de la Calidad Total
19.
Nanotechnology ; 27(17): 174002, 2016 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-26987282

RESUMEN

The ability to effectively screen and validate gas-diffusion electrodes is critical to the development of next-generation metal-air batteries and regenerative fuel cells. The limiting electrode in a classic two-terminal device such as a battery or fuel cell is difficult to discern without an internal reference electrode, but the flooded electrolyte characteristic of three-electrode electroanalytical cells negates the prime function of an air electrode-a void volume freely accessible to gases. The nanostructured catalysts that drive the energy-conversion reactions (e.g., oxygen reduction and evolution in the air electrode of metal-air batteries) are best evaluated in the electrode structure as-used in the practical device. We have designed, 3D-printed, and characterized an air-breathing, thermodynamically referenced electroanalytical cell that allows us to mimic the Janus arrangement of the gas-diffusion electrode in a metal-air cell: one face freely exposed to gases, the other wetted by electrolyte.

20.
Am J Respir Crit Care Med ; 192(10): 1200-7, 2015 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-26241562

RESUMEN

RATIONALE: Estimates of idiopathic pulmonary fibrosis (IPF) incidence and prevalence from electronic databases without case validation may be inaccurate. OBJECTIVES: Develop claims algorithms to identify IPF and assess their positive predictive value (PPV) to estimate incidence and prevalence in the United States. METHODS: We developed three algorithms to identify IPF cases in the HealthCore Integrated Research Database. Sensitive and specific algorithms were developed based on literature review and consultation with clinical experts. PPVs were assessed using medical records. A third algorithm used logistic regression modeling to generate an IPF score and was validated using a separate set of medical records. We estimated incidence and prevalence of IPF using the sensitive algorithm corrected for the PPV. MEASUREMENTS AND MAIN RESULTS: We identified 4,598 patients using the sensitive algorithm and 2,052 patients using the specific algorithm. After medical record review, the PPVs of these algorithms using the treating clinician's diagnosis were 44.4 and 61.7%, respectively. For the IPF score, the PPV was 76.2%. Using the clinical adjudicator's diagnosis, the PPVs were 54 and 57.6%, respectively, and for the IPF score, the PPV was 83.3%. The incidence and period prevalences of IPF, corrected for the PPV, were 14.6 per 100,000 person-years and 58.7 per 100,000 persons, respectively. CONCLUSIONS: Sensitive algorithms without correction for false positive errors overestimated incidence and prevalence of IPF. An IPF score offered the greatest PPV, but it requires further validation.


Asunto(s)
Fibrosis Pulmonar Idiopática/epidemiología , Registros Médicos/estadística & datos numéricos , Distribución por Edad , Anciano , Anciano de 80 o más Años , Algoritmos , Comorbilidad , Bases de Datos Factuales , Femenino , Humanos , Incidencia , Revisión de Utilización de Seguros , Modelos Logísticos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Prevalencia , Reproducibilidad de los Resultados , Estudios Retrospectivos , Distribución por Sexo , Estados Unidos/epidemiología
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