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1.
Proc Natl Acad Sci U S A ; 121(26): e2316438121, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38900799

RESUMO

Phase transitions occurring in nonequilibrium conditions can evolve through high-energy intermediate states inaccessible via equilibrium adiabatic conditions. Because of the subtle nature of such hidden phases, their direct observation is extremely challenging and requires simultaneous visualization of matter at subpicoseconds and subpicometer scales. Here, we show that a magnetite crystal in the vicinity of its metal-to-insulator transition evolves through different hidden states when controlled via energy-tuned ultrashort laser pulses. By directly monitoring magnetite's crystal structure with ultrafast electron diffraction, we found that upon near-infrared (800 nm) excitation, the trimeron charge/orbital ordering pattern is destroyed in favor of a phase-separated state made of cubic-metallic and monoclinic-insulating regions. On the contrary, visible light (400 nm) activates a photodoping charge transfer process that further promotes the long-range order of the trimerons by stabilizing the charge density wave fluctuations, leading to the reinforcement of the monoclinic insulating phase. Our results demonstrate that magnetite's structure can evolve through completely different metastable hidden phases that can be reached long after the initial excitation has relaxed, breaking ground for a protocol to control emergent properties of matter.

2.
Phys Chem Chem Phys ; 26(21): 15338-15343, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38753220

RESUMO

The activity in CO oxidation of regular arrays of Pd clusters, in the size range of 5-180 atoms, supported on alumina has been studied by using a molecular beam method. The Pd clusters are grown on a nanostructured ultrathin alumina film on Ni3Al(111) providing a hexagonal array of clusters with a narrow size distribution. The steady state turnover frequency (TOF) is measured as a function of the mean cluster size. On average the TOF increases with size. Below about 20 atoms, the TOF increases rapidly and for larger clusters it grows slowly and reaches a value close to those obtained on bulk single crystals at 180 atoms. The size effect is explained by the smaller activity of Pd atoms in contact with the alumina support.

3.
J Immunol ; 199(7): 2515-2527, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28848068

RESUMO

Dual-specificity phosphatase 3 (DUSP3) is a small phosphatase with poorly known physiological functions and for which only a few substrates are known. Using knockout mice, we recently reported that DUSP3 deficiency confers resistance to endotoxin- and polymicrobial-induced septic shock. We showed that this protection was macrophage dependent. In this study, we further investigated the role of DUSP3 in sepsis tolerance and showed that the resistance is sex dependent. Using adoptive-transfer experiments and ovariectomized mice, we highlighted the role of female sex hormones in the phenotype. Indeed, in ovariectomized females and in male mice, the dominance of M2-like macrophages observed in DUSP3-/- female mice was reduced, suggesting a role for this cell subset in sepsis tolerance. At the molecular level, DUSP3 deletion was associated with estrogen-dependent decreased phosphorylation of ERK1/2 and Akt in peritoneal macrophages stimulated ex vivo by LPS. Our results demonstrate that estrogens may modulate M2-like responses during endotoxemia in a DUSP3-dependent manner.


Assuntos
Fosfatases de Especificidade Dupla/genética , Fosfatases de Especificidade Dupla/metabolismo , Endotoxemia/enzimologia , Endotoxemia/prevenção & controle , Estrogênios/metabolismo , Macrófagos/fisiologia , Choque Séptico/prevenção & controle , Animais , Coinfecção/complicações , Fosfatases de Especificidade Dupla/deficiência , Endotoxemia/genética , Endotoxemia/microbiologia , Feminino , Tolerância Imunológica , Lipopolissacarídeos/imunologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Knockout , Ovariectomia , Fosforilação , Caracteres Sexuais , Transdução de Sinais
4.
J Chem Phys ; 151(17): 174703, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31703513

RESUMO

The Langmuir-Hinshelwood barrier (ELH) and the pre-exponential factor (νLH) for CO oxidation have been measured at high temperatures on hexagonal arrays of Pd clusters supported on an ultrathin alumina film on Ni3Al (111). The Pd clusters have a sharp size distribution, and the mean sizes are 174 ± 13, 360 ± 19, and 768 ± 28 atoms. ELH and νLH are determined from the initial reaction rate of a CO molecular beam with a saturation layer of adsorbed oxygen on the Pd clusters measured at different temperatures [493 ≤ T(K) ≤ 613]. The largest particles (3.5 nm) give values of ELH and νLH similar to those measured on Pd (111) [T. Engel and G. Ertl, J. Chem. Phys. 69, 1267 (1978)]. However, smaller particles (2.7 and 2.1 nm) show very different behaviors. The origin of this size effect is discussed in terms of variation of the electronic structure and of the atomic structure of the Pd clusters.

5.
J Community Health ; 44(1): 178-184, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30194519

RESUMO

Although better community health has long been assumed to be good for local businesses, evidence demonstrating the relationship between community health and employee performance is quite limited. Drawing on human resources data on 6103 employees from four large US manufacturing plants, we found that employees living in counties with poor community health outcomes had considerably higher rates of absenteeism and tardiness (ABT). For example, in one company, employees living in communities with high rates of children on free or reduced lunch had higher rates of ABT compared to other employees [adjusted odds ratio (OR) 2.76, 95% confidence interval (CI) 2.52-3.04], and employees living in communities with high rates of drug overdose deaths had higher rates of ABT (OR 1.51, 95% CI 1.29-1.77). In one plant, the annual value of lost wages due to ABT was over $1.3 million per year. Employees reported that poor community health (e.g., poverty, caregiving burdens, family dysfunction, drug use) resulted in "mental stress" leading to distraction, poor job performance, and more rarely, lapses in safety. These findings bolster the case for greater private sector investment in community health.


Assuntos
Absenteísmo , Saúde Ocupacional/estatística & dados numéricos , Desempenho Profissional/estatística & dados numéricos , Local de Trabalho/estatística & dados numéricos , Adulto , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Setor Privado/estatística & dados numéricos , Estresse Psicológico , Estados Unidos , Recursos Humanos/estatística & dados numéricos
6.
Langmuir ; 34(19): 5381-5385, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29678113

RESUMO

We demonstrate in this work that using nanoplasmonic sensing it is possible to follow the adsorption/desorption of water molecules on gold nanodisks nanofabricated by electron beam lithography. This quantitative method is highly sensitive allowing the detection of a few hundredths of adsorbed monolayer. Disk parameters (height, diameter, and interdisk distance) have been optimized after finite-difference time-domain (FDTD) simulations in order to obtain the best localized surface plasmon resonance (LSPR) signal-to-noise ratio. Finally, we have precisely measured the adsorption kinetics of water on gold as a function of the relative humidity of the surrounding medium.

7.
J Community Health ; 43(3): 560-565, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29218540

RESUMO

Virtually all large employers engage in corporate philanthropy, but little is known about the extent to which it is directed toward improving community health. We conducted in-depth interviews with leaders of corporate philanthropy from 13 of the largest manufacturing companies in the US to understand how giving decisions were made, the extent to which funding was directed towards improving community health, and whether companies coordinate with local public health agencies. We found that corporate giving was sizable and directed towards communities in which the manufacturers have a large presence. Giving was aligned with the social determinants of health (i.e., aimed at improving economic stability, the neighborhood and physical environment, education, food security and nutrition, the community and social context, and the health care system). However, improving public health was not often cited as a goal of corporate giving, and coordination with public health agencies was limited. Our results suggest that there may be opportunities for public health agencies to help guide corporate philanthropy, particularly by sharing community-level data and offering their measurement and evaluation expertise.


Assuntos
Obtenção de Fundos , Indústrias , Saúde Pública/economia , Humanos , Indústrias/economia , Indústrias/organização & administração , Características de Residência
8.
Anal Chem ; 89(17): 8723-8730, 2017 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-28758730

RESUMO

This work demonstrates the development of an online two-dimensional liquid chromatography (2D-LC) method where the first dimension column is eluted by a sequence of pulses of increasing eluotropic strength generated by the LC pumps (pulsed-elution 2D-LC). Between the pulses, the first dimension is kept in a no-elution state using low eluent strength. The eluate from the first dimension is actively modulated using trap columns and subsequently analyzed in the second dimension. We demonstrate that by tuning the length and eluotropic strength of the pulses, peaks with retention factors in water, kw, above 150 can be manipulated to elute in 3-4 pulses. The no-elution state can be kept for 1-10 min with only minor changes as to which and how many pulses the peaks elute in. Pulsed-elution 2D-LC combined with active modulation tackles three of the main challenges encountered in 2D-LC and specifically online comprehensive 2D-LC: undersampling, difficulties in refocusing, and lack of flexibility in the selection of column dimensions and flow rates because the two dimensions constrain each other. The pulsed-elution 2D-LC was applied for the analysis of a basic fraction of vacuum gas oil. Peak capacity was 4018 for a 540 min analysis and 4610 for a 1040 min analysis.

9.
Analyst ; 140(6): 1921-31, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25655051

RESUMO

The emergence of micro sampling techniques holds great potential to improve pharmacokinetic data quality, reduce animal usage, and save costs in safety assessment studies. The analysis of these samples presents new challenges for bioanalytical scientists, both in terms of sample processing and analytical sensitivity. The use of two dimensional LC/MS with, at-column-dilution for the direct analysis of highly organic extracts prepared from biological fluids such as dried blood spots and plasma is demonstrated. This technique negated the need to dry down and reconstitute, or dilute samples with water/aqueous buffer solutions, prior to injection onto a reversed-phase LC system. A mixture of model drugs, including bromhexine, triprolidine, enrofloxacin, and procaine were used to test the feasibility of the method. Finally an LC/MS assay for the probe pharmaceutical rosuvastatin was developed from dried blood spots and protein-precipitated plasma. The assays showed acceptable recovery, accuracy and precision according to US FDA guidelines. The resulting analytical method showed an increase in assay sensitivity of up to forty fold as compared to conventional methods by maximizing the amount loaded onto the system and the MS response for the probe pharmaceutical rosuvastatin from small volume samples.


Assuntos
Cromatografia Líquida de Alta Pressão/instrumentação , Teste em Amostras de Sangue Seco/instrumentação , Análise de Injeção de Fluxo/instrumentação , Espectrometria de Massas/instrumentação , Preparações Farmacêuticas/sangue , Desenho de Equipamento , Fluorbenzenos/sangue , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/sangue , Compostos Orgânicos , Plasma/química , Pirimidinas/sangue , Reprodutibilidade dos Testes , Rosuvastatina Cálcica , Tamanho da Amostra , Solventes , Sulfonamidas/sangue
10.
Appl Opt ; 53(31): LIM1-3, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25402939

RESUMO

Laser-materials interaction is the fascinating nexus where laser physics, optical physics, and materials science intersect. Applications include microdeposition via laser-induced forward transfer of thin films, clean materials processing with femtosecond beams, creating color filters with nanoparticles, generating very high density storage sites on subpicosecond time scales, structuring solar cell surfaces for higher efficiency, making nanostructures that would be impossible by other means, and creating in-volume waveguiding structures using femtosecond laser filaments.

11.
Appl Opt ; 53(31): I41-4, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25402936

RESUMO

Significant advances have been made over the last decade to improve the performance, efficiency, and contrast of high peak and average power laser systems, driven by their use in a wide variety of fields, from the industrial to the scientific. As the contrast of the lasers has improved, interactions with contrasts of 1012 are now routinely undertaken. At such high contrasts, there is negligible preplasma formation and the ionized surface layer created by subpicosecond-duration pulses typically forms a highly reflective "plasma mirror" capable of reflecting between 70% and 90% of the incident energy. Although such interactions are of significant interest for applications such as harmonic source production and to enable the underlying physics to be studied, their low absorption can limit their usefulness for applications such as space debris removal.

12.
Nano Lett ; 13(5): 1977-82, 2013 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-23537306

RESUMO

The evolution of the adsorption energy of carbon monoxide (CO) molecules on palladium (Pd) clusters as function of Pd particle size from the molecular regime (less than ~100 atoms per particle) to the bulk regime has been revealed. This adsorption energy is retrieved from the residence time of CO molecules on the Pd clusters, measured by a pulsed molecular beam technique, versus temperature. Unprecedented accuracy on the determination of the particle size has been achieved here by using a regular array of metal clusters exhibiting a size dispersion down to the ultimate limit of a Poisson distribution. This allows getting rid of the convolution effects that generally occur when considering particles grown through other techniques.


Assuntos
Monóxido de Carbono/química , Paládio/química , Tamanho da Partícula , Propriedades de Superfície , Temperatura
13.
Proc Natl Acad Sci U S A ; 107(25): 11537-42, 2010 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-20534522

RESUMO

Escherichia coli is a normal inhabitant of the human gut. However, E. coli strains of phylogenetic group B2 harbor a genomic island called "pks" that codes for the production of a polyketide-peptide genotoxin, Colibactin. Here we report that in vivo infection with E. coli harboring the pks island, but not with a pks isogenic mutant, induced the formation of phosphorylated H2AX foci in mouse enterocytes. We show that a single, short exposure of cultured mammalian epithelial cells to live pks(+) E. coli at low infectious doses induced a transient DNA damage response followed by cell division with signs of incomplete DNA repair, leading to anaphase bridges and chromosome aberrations. Micronuclei, aneuploidy, ring chromosomes, and anaphase bridges persisted in dividing cells up to 21 d after infection, indicating occurrence of breakage-fusion-bridge cycles and chromosomal instability. Exposed cells exhibited a significant increase in gene mutation frequency and anchorage-independent colony formation, demonstrating the infection mutagenic and transforming potential. Therefore, colon colonization with these E. coli strains harboring the pks island could contribute to the development of sporadic colorectal cancer.


Assuntos
Dano ao DNA , Escherichia coli/metabolismo , Instabilidade Genômica , Intestinos/microbiologia , Animais , Células CHO , Adesão Celular , Aberrações Cromossômicas , Cricetinae , Cricetulus , Reparo do DNA , Escherichia coli/genética , Camundongos , Camundongos Endogâmicos BALB C , Mutagênicos/metabolismo , Mutação , Neoplasias/metabolismo
14.
J Rural Health ; 39(1): 61-68, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35829624

RESUMO

PURPOSE: Anchor institutions ("anchors") are large employers, rooted in a community by reason of mission, capital, or relationships. Many anchors have encouraged coronavirus vaccination for employees and their families. Our objective was to determine whether the presence of an anchor was associated with a higher county-level vaccination rate. METHODS: A cross-sectional study focused on 745 small- and mid-sized US counties. We used data from the Centers for Disease Control and Prevention, Reference USA's US Business Database, Economic Innovation Group's Distressed Communities Index database, 2021 County Health Ratings and Rankings, 2020 US Presidential Election popular vote data, and National Center for Health Statistics urban-rural classification data. We constructed 3 explanatory variables of interest: a binary variable indicating whether the county had an anchor; a continuous variable representing the number of anchors within a county; and the percent of all workers in the county who were employed by an anchor. Multivariable linear regression models were adjusted for race/ethnicity, political party allegiance, rurality, economic distress, and prevalence of smoking and adult obesity. FINDINGS: Counties with an anchor had vaccination rates 2.31 (P<.01) percentage points higher than those without an anchor. The number of anchors in a county was also significantly associated with higher vaccination rates. CONCLUSIONS: Efforts by anchors to encourage vaccination may have been successful, and that anchors may be well positioned to amplify public health messages. However, the influence and efforts of anchors to increase vaccination did not fully mitigate disparities in vaccination rates by race, ethnicity, and political party allegiance.


Assuntos
Coronavirus , Etnicidade , Adulto , Humanos , Estados Unidos/epidemiologia , Estudos Transversais , Obesidade/epidemiologia , Fumar
15.
J Occup Environ Med ; 65(12): 1003-1007, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37590376

RESUMO

OBJECTIVE: This study aimed to describe the actions used by health professionals employed by large, for-profit businesses to promote uptake of COVID-19 vaccines, and factors that facilitated and hindered coordination with local public health leaders. METHODS: In this qualitative multiple case study, we conducted telephone interviews with health professionals from businesses, health department leaders, and others who could provide information about local vaccination efforts (e.g., emergency managers, reporters). RESULTS: Businesses' self-interest (i.e., need to keep employees working), vaccine mandates, and characteristics of the businesses (e.g., ownership, expertise) facilitated leadership in COVID-19 vaccination efforts. Coordination with local health departments was influenced by the resources of the local health department and history of collaboration. CONCLUSIONS: Health professionals employed by large businesses can serve as key public health partners, but their role is shaped by characteristics of the businesses and communities.


Assuntos
COVID-19 , Saúde Pública , Humanos , Vacinas contra COVID-19 , COVID-19/prevenção & controle , Vacinação , Propriedade
16.
Sci Data ; 10(1): 30, 2023 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-36641528

RESUMO

A consistent dataset of lake surface water temperature, ice cover, water-leaving reflectance, water level and extent is presented. The collection constitutes the Lakes Essential Climate Variable (ECV) for inland waters. The data span combined satellite observations from 1992 to 2020 inclusive and quantifies over 2000 relatively large lakes, which represent a small fraction of the number of lakes worldwide but a significant fraction of global freshwater surface. Visible and near-infrared optical imagery, thermal imagery and microwave radar data from satellites have been exploited. All observations are provided in a common grid at 1/120° latitude-longitude resolution, jointly in daily files. The data/algorithms have been validated against in situ measurements where possible. Consistency analysis between the variables has guided the development of the joint dataset. It is the most complete collection of consistent satellite observations of the Lakes ECV currently available. Lakes are of significant interest to scientific disciplines such as hydrology, limnology, climatology, biogeochemistry and geodesy. They are a vital resource for freshwater supply, and key sentinels for global environmental change.

17.
Front Med (Lausanne) ; 9: 795957, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35872767

RESUMO

Health care is shifting toward become proactive according to the concept of P5 medicine-a predictive, personalized, preventive, participatory and precision discipline. This patient-centered care heavily leverages the latest technologies of artificial intelligence (AI) and robotics that support diagnosis, decision making and treatment. In this paper, we present the role of AI and robotic systems in this evolution, including example use cases. We categorize systems along multiple dimensions such as the type of system, the degree of autonomy, the care setting where the systems are applied, and the application area. These technologies have already achieved notable results in the prediction of sepsis or cardiovascular risk, the monitoring of vital parameters in intensive care units, or in the form of home care robots. Still, while much research is conducted around AI and robotics in health care, adoption in real world care settings is still limited. To remove adoption barriers, we need to address issues such as safety, security, privacy and ethical principles; detect and eliminate bias that could result in harmful or unfair clinical decisions; and build trust in and societal acceptance of AI.

18.
Small ; 7(2): 235-41, 2011 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-21213388

RESUMO

The morphology of platinum nanoparticles synthesized using an organometallic approach from PtMe(2) (C(8) H(12) ) is influenced by the nature of the ligands used as stabilizing agents. The use of long alkyl chain amines leads to the formation of multipodal nanoparticles that transform into compact nano-objects, adopting cubic, truncated cubic, or cuboctahedral shapes. In contrast, the use of diamine ligands allows the growth of compact (111) arrowlike faces, forming polycrystalline nanoparticles of an overall desert-rose aspect. Different reaction parameters are studied ([ligand]/[metal] ratio, temperature, solvent identity) in order to optimize the various shapes.


Assuntos
Nanopartículas Metálicas/química , Platina/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Nanotecnologia
19.
Tex Dent J ; 128(12): 1261-7, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22375444

RESUMO

BACKGROUND: The objectives of this study were to evaluate the debonding strength and mode of failure of a selenium containing adhesive compared to an established orthodontic adhesive. MATERIALS AND METHODS: One hundred sixty bovine mandibular incisors were allocated to eight groups: steel and clear brackets were bonded with either selenium containing adhesive (Group 1: SeLect Defense) or a conventional light-cured adhesive (Group 2:Transbond XT) to measure debond strength and the adhesive remnant index was used to assess the location of bond failure. Data was evaluated using a three-way analysis of variance and Fisher's PLSD multiple comparisons test for mean debond strengths. RESULTS: Group 2 debond strengths were greater than that of Group 1 with the steel and clear brackets. Group 1 debond strengths were greater with clear than with steel brackets at both time points. Both adhesives demonstrated increased debond strengths from zero to 24 hours and the clear brackets exhibited a greater ARI than steel after debonding. Comparisons of debond strength means among adhesives, brackets, and times were all statistically significant. CONCLUSIONS/DISCUSSION: All debond strengths were within a clinically acceptable range according to previous literature. SeLect Defense may be desirable due to its potential for preventing white spot lesions despite the reduced strength compared to Transbond XT.


Assuntos
Colagem Dentária , Cimentos Dentários/química , Cura Luminosa de Adesivos Dentários , Braquetes Ortodônticos , Selênio/química , Adesividade , Óxido de Alumínio/química , Animais , Bovinos , Ligas Dentárias/química , Descolagem Dentária , Esmalte Dentário/anatomia & histologia , Análise do Estresse Dentário/instrumentação , Distribuição Aleatória , Cimentos de Resina/química , Resistência ao Cisalhamento , Aço Inoxidável/química , Estresse Mecânico , Propriedades de Superfície , Fatores de Tempo
20.
ACS Omega ; 6(20): 13398-13405, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34056487

RESUMO

We used indirect nanoplasmonic sensing (INPS) coupled with mass spectrometry to study CO and oxygen adsorption as well as CO oxidation, on Pt nanoparticles, in the Torr pressure range. Due to an optimization of the physical parameters of our plasmonic sample, we obtain a highly sensitive probe that can detect gas adsorption of a few hundredths of a monolayer, even with a very low number density of Pt particles. Moreover and for the first time, a similarity is observed between the sign and the evolution of the localized surface plasmon resonance (LSPR) peak shift and the work function measurements for CO and oxygen chemisorption. Controlling the size, shape, and surface density of Pt particles, the turnover frequency (TOF) has also been accurately determined. For similar experimental conditions, the TOF is close to those measured on Pt/oxide powder catalysts and Pt(100) single crystals.

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