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1.
Int J Gynecol Pathol ; 40(3): 240-247, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32897964

RESUMEN

Beta-catenin (BC) mutations are associated with a high risk of recurrence in otherwise low-grade, early-stage uterine endometrioid adenocarcinomas. Recent literature suggests nuclear BC expression by immunohistochemistry is highly sensitive and specific for BC mutations. The significance of BC expression in endometrioid intraepithelial neoplasia (EIN/atypical hyperplasia) and its relationship to altered differentiation patterns in EIN has yet to be fully explored. Cases meeting current diagnostic criteria for EIN based on H&E examination were obtained from 2 institutions (years 1999-2014). Patterns of altered differentiation (eg, tubal, squamous morular metaplasia, mucinous, secretory) were noted. Representative blocks were stained for BC, and expression patterns recorded. Follow-up and demographic data was obtained from the electronic medical record. Ninety-six cases were included (84 biopsies, 12 hysterectomies). BC nuclear expression was identified in 41 cases (42.7%), with 33 of 41 demonstrating foci of nonmorular BC staining. BC staining in any component of EIN was not significantly associated with the presence of carcinoma on subsequent hysterectomy (P=0.79). When restricting to nonmorular BC, the results were the same (P=0.56). Cases with tubal differentiation were significantly less likely to demonstrate nonmorular BC than cases with no specific pattern of differentiation (P<0.01). EIN frequently demonstrates BC nuclear positivity, especially in cases without tubal differentiation. BC nuclear expression in EIN does not appear to be associated with an increased likelihood of carcinoma on subsequent hysterectomy. Our results do not support routine use of BC immunohistochemistry as a prognostic biomarker in cases of EIN.


Asunto(s)
Carcinoma in Situ/diagnóstico , Carcinoma Endometrioide/diagnóstico , Neoplasias Endometriales/diagnóstico , beta Catenina/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/metabolismo , Carcinoma in Situ/patología , Carcinoma in Situ/cirugía , Carcinoma Endometrioide/patología , Carcinoma Endometrioide/cirugía , Núcleo Celular/metabolismo , Neoplasias Endometriales/patología , Neoplasias Endometriales/cirugía , Femenino , Humanos , Histerectomía , Persona de Mediana Edad , Pronóstico , Riesgo , beta Catenina/genética
2.
Eur J Vasc Endovasc Surg ; 59(6): 957-964, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32336621

RESUMEN

OBJECTIVE: The aims of this study were firstly to assess the correlation between disease specific measures of quality of life (QOL) and physical performance and activity, and secondly to identify demographic, clinical, functional, and physical activity measures independently associated with QOL in people with intermittent claudication. METHODS: This was a cross sectional observational study of 198 people with intermittent claudication caused by peripheral artery disease who were recruited prospectively. QOL was assessed with the intermittent claudication questionnaire (ICQ) and the eight-theme peripheral artery disease quality of life questionnaire. Physical performance was assessed with the six minute walk test (6MWT) and short physical performance battery (SPPB), and an accelerometer was used to measure seven day step count. The associations between QOL scores and 6MWT distance, SPPB scores and seven day step count were examined using Spearman Rho's (ρ) correlation and multivariable linear regression. RESULTS: ICQ scores were significantly correlated with 6MWT distance (ρ = 0.472, p < .001), all four SPPB scores (balance ρ = 0.207, p = .003; gait speed ρ = 0.303, p < .001; chair stand ρ = 0.167, p = .018; total ρ = 0.265, p < .001), and seven day step count (ρ = 0.254, p < .001). PADQOL social relationships and interactions (ρ = 0.343, p < .001) and symptoms and limitations in physical functioning (ρ = 0.355, p < .001) themes were correlated with 6MWT distance. The 6MWT distance was independently positively associated with ICQ and both PADQOL theme scores (ICQ: B 0.069, p < .001; PADQOL social relationships and interactions: B 0.077, p < .001; PADQOL symptoms and limitations in physical functioning: B 0.069, p < .001). CONCLUSION: Longer 6MWT distance independently predicted better physical and social aspects of QOL in people with intermittent claudication supporting its value as an outcome measure.


Asunto(s)
Claudicación Intermitente/diagnóstico , Medición de Resultados Informados por el Paciente , Enfermedad Arterial Periférica/complicaciones , Rendimiento Físico Funcional , Calidad de Vida , Anciano , Estudios Transversales , Femenino , Humanos , Claudicación Intermitente/etiología , Claudicación Intermitente/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Prueba de Paso
3.
J Chem Phys ; 150(4): 044702, 2019 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-30709253

RESUMEN

Using an advanced computational methodology implemented in CP2K, a non-local PBE0-TC-LRC density functional and the recently implemented linear response formulation of the Time-dependent Density Functional Theory equations, we test the interpretation of the optical absorption and photoluminescence signatures attributed by previous experimental and theoretical studies to O-vacancies in two widely used oxides-cubic MgO and monoclinic (m)-HfO2. The results obtained in large periodic cells including up to 1000 atoms emphasize the importance of accurate predictions of defect-induced lattice distortions. They confirm that optical transitions of O-vacancies in 0, +1, and +2 charge states in MgO all have energies close to 5 eV. We test the models of photoluminescence of O-vacancies proposed in the literature. The photoluminescence of VO +2 centers in m-HfO2 is predicted to peak at 3.7 eV and originate from radiative tunneling transition between a VO +1 center and a self-trapped hole created by the 5.2 eV excitation.

4.
Am Heart J ; 201: 111-116, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29763816

RESUMEN

The prognosis of patients with HFrEF remains poor despite the use of current medical and device therapies. Preclinical studies of HFrEF using IC delivery of RT-100, a replication deficient, E1/E3-deleted human adenovirus 5 encoding human AC6 was associated with favorable effects on LV function and remodeling. A recent multicenter, double-blind, placebo-controlled, phase 2 study demonstrated the safety of IC delivery of RT-100 in HFrEF patients and potential efficacy at the higher doses. This phase 2 dose finding study, which included doses not expected to be effective, identified a potential reduction in congestive heart failure admissions in the AC6-treated group one year after randomization. The FLOURISH study is designed to investigate the prospect of reduction of heart failure hospitalization and other clinical adverse events and improvement in EF. The FLOURISH study is a double-blind, placebo-controlled, multicenter Phase 3 clinical trial that will randomize 536 patients to a one-time IC administration of RT-100 (1012 vp) or placebo in a 1:1 ratio. Subjects will be 18-80 years of age, on optimal standard of care HF therapy with LVEF ≥10% and ≤35% by echocardiogram, and will undergo IC administration of RT-100 vs. placebo on Day 1. Follow-up study visits will be performed at Weeks 1 and 4, and Months 3, 6, and 12. Patients will be followed for an additional 36 months for safety assessments with telephone contact at Months 24, 36, and 48. The primary objective is to determine the efficacy of IC RT-100 vs. placebo in reducing the event rate of all (first and repeat) HF hospitalizations occurring from baseline to 12 months. The secondary objectives are to determine the efficacy of IC RT-100 on CV death, all cause death, and all HF events and in improving NYHA functional classification. Exploratory endpoints will include echocardiographic parameters of left ventricular systolic and diastolic function, HF symptoms and physical limitations, 6-minute walking distance, Borg dyspnea score, and NT-proBNP levels. The FLOURISH study, which received fast track designation from the Food and Drug Administration in December 2017, will further investigate the role of a one-time intracoronary injection of RT-100 in reducing HF hospitalizations and will serve as a registration trial (potentially pivotal investigation) for RT-100 as a treatment for HFrEF.


Asunto(s)
Adenilil Ciclasas/administración & dosificación , Ensayos Clínicos Fase III como Asunto/métodos , Técnicas de Transferencia de Gen , Terapia Genética/métodos , Insuficiencia Cardíaca/terapia , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Volumen Sistólico/fisiología , Adenovirus Humanos , Vasos Coronarios , Insuficiencia Cardíaca/fisiopatología , Humanos , Inyecciones Intraarteriales , Función Ventricular Izquierda/fisiología
6.
J Comput Chem ; 36(16): 1187-95, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-25891018

RESUMEN

We present an efficient scheme for parametrizing complex molecule-surface force fields from ab initio data. The cost of producing a sufficient fitting library is mitigated using a 2D periodic embedded slab model made possible by the quantum mechanics/molecular mechanics scheme in CP2K. These results were then used in conjunction with genetic algorithm (GA) methods to optimize the large parameter sets needed to describe such systems. The derived potentials are able to well reproduce adsorption geometries and adsorption energies calculated using density functional theory. Finally, we discuss the challenges in creating a sufficient fitting library, determining whether or not the GA optimization has completed, and the transferability of such force fields to similar molecules.

7.
Phys Rev Lett ; 114(11): 115503, 2015 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-25839289

RESUMEN

Using ab initio modeling we demonstrate that H atoms can break strained Si─O bonds in continuous amorphous silicon dioxide (a-SiO(2)) networks, resulting in a new defect consisting of a threefold-coordinated Si atom with an unpaired electron facing a hydroxyl group, adding to the density of dangling bond defects, such as E' centers. The energy barriers to form this defect from interstitial H atoms range between 0.5 and 1.3 eV. This discovery of unexpected reactivity of atomic hydrogen may have significant implications for our understanding of processes in silica glass and nanoscaled silica, e.g., in porous low-permittivity insulators, and strained variants of a-SiO(2).

8.
MethodsX ; 12: 102534, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38223219

RESUMEN

Outdoor air pollution has been found to have a significant adverse effect on health. When the authors attempted to monitor air quality that cyclists or e-scooter users' breath during commuting in different locations for health and safety analysis, it was found that the existence of internal combustion engine (ICE) cars has a significant effect on the pollution levels and the monitoring process. To comprehensively study the effect of cars and traffic on air quality that cyclists and e-scooters users experience, a low-cost and reliable system was needed to detect the proximity of cars that have diesel or petrol engines. Video cameras can be used to visually detect vehicles, but in the modern age with the existence of many electric and hybrid vehicles and the need to reduce the cost of instrumentation, there was a need to determine the passing of vehicles near e-scooter and bike users from the combined engine and tires sounds. To address this issue, this study suggests a novel approach of using sound waves of internal combustion engines and tire sounds during the passing of cars, combined with AI techniques (neural networks), to detect the proximity of cars from cyclists and e-scooter users. Audio-visual data was collected using Go-Pro cameras in order to combine the data with GPS location and pollution levels. Geographical data maps were produced to demonstrate the density of cars that cyclists encounter when on or near the road. This method will enable air quality monitoring research to detect the existence of ICE cars for future correlation with measured pollution levels. The proposed method allows for:•The automated selection of sensitive features from sound waves to detect vehicles.•Low-cost hardware which is independent of orientation that can be integrated with other air quality and GPS sensors.•The successful application of sensor fusion and neural networks.

9.
Artículo en Inglés | MEDLINE | ID: mdl-39041926

RESUMEN

Metal-organic frameworks (MOFs) are increasingly being investigated as electrocatalysts for the oxygen evolution reaction (OER) due to their unique modular structures that present a hybrid between molecular and heterogeneous catalysts, featuring well-defined active sites. However, many fundamental questions remain open regarding the electrochemical stability of MOFs, structural reconstruction of coordination sites, and the role of in situ-formed species. Here, we report the structural transformation of a surface-grown MOF containing cobalt nodes and 1,1'-ferrocenedicarboxylic acid linkers (denoted as CoFc-MOF) during the OER in alkaline electrolyte. Ex situ and in situ investigations of CoFc-MOF film suggest that the MOF acts as a precatalyst and undergoes a two-step restructuring process under operating conditions to generate a metal oxyhydroxide phase. The MOF-derived metal oxyhydroxide catalyst, supported on nickel foam electrodes, displays high activity toward the OER with an overpotential of 190 mV at a current density of 10 mA cm-2. While this study demonstrates the necessity of investigating structural evolution of MOFs during electrocatalysis, it also shows the potential of using MOFs as precursors in catalyst design.

10.
Environ Int ; 188: 108751, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38761430

RESUMEN

Microplastics (MPs) are an everyday part of life, and are now ubiquitous in the environment. Crucially, MPs have not just been found within the environment, but also within human bodies, including the blood. We aimed to provide novel information on the range of MP polymer types present, as well as their size and shape characteristics, in human whole blood from 20 healthy volunteers. Twenty-four polymer types were identified from 18 out of 20 (90 %) donors and quantified in blood, with the majority observed for the first time. Using an LOQ approach, five polymer types met the threshold with a lower mean ± SD of 2466 ± 4174 MP/L. The concentrations of plastics analysed in blood samples ranged from 1.84 - 4.65 µg/mL. Polyethylene (32 %), ethylene propylene diene (14 %), and ethylene-vinyl-acetate/alcohol (12 %) fragments were the most abundant. MP particles that were identified within the blood samples had a mean particle length of 127.99 ± 293.26 µm (7-3000 µm), and a mean particle width of 57.88 ± 88.89 µm (5-800 µm). The MPs were predominantly categorised as fragments (88 %) and were white/clear (79 %). A variety of plastic additive chemicals were identified including endocrine disrupting-classed phthalates. The procedural blank samples comprised 7 polymer types, that were distinct from those identified in blood, mainly resin (25 %), polyethylene terephthalate (17 %), and polystyrene (17 %) with a mean ± SD of 4.80 ± 5.59 MP/L. This study adds to the growing evidence that MPs are taken up into the human body and are transported via the bloodstream. The shape and sizes of the particles raise important questions with respect to their presence and associated hazards in terms of potential detrimental impacts such as vascular inflammation, build up within major organs, and changes to either immune cell response, or haemostasis and thrombosis.


Asunto(s)
Microplásticos , Humanos , Microplásticos/análisis , Polímeros , Adulto , Masculino , Femenino , Plásticos , Monitoreo del Ambiente/métodos , Adulto Joven , Tamaño de la Partícula
11.
Phys Chem Chem Phys ; 15(45): 19615-24, 2013 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-24131905

RESUMEN

We evaluate the performance of different van der Waals (vdW) corrected density functional theory (DFT) methods in predicting the structure of perfect interfaces between the LiF(001), MgO(001), NiO(001) films on the Ag(001) surface and the resulting work function shift of Ag(001). The results demonstrate that including the van der Waals interaction is important for obtaining accurate interface structures and the metal work function shift. The work function shift results from a subtle interplay of several effects strongly affected by even small changes in the interface geometry. This makes the accuracy of theoretical methods insufficient for predicting the shift values better than within 0.2 eV. Most of the existing van der Waals corrected functionals are not particularly suited for studying metal/insulator interfaces. The lack of accurate experimental data on the interface geometries and surface rumpling of insulators hampers the calibration of existing and novel density functionals.

12.
J Chem Phys ; 138(15): 154703, 2013 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-23614432

RESUMEN

The critical quantity in understanding imaging using an atomic force microscope is the force the sample exerts on the tip. We put forward a simple one-to-one force to water density relationship, explain exactly how it occurs, and in which circumstances it holds. We argue that two wide classes of atomic force microscope (AFM) tip should lead to at least qualitative agreement with our model and represent a significant fraction of AFM tips as currently prepared. This connection between the short-range force and the unperturbed equilibrium water density removes the need to perform simulations for each tip location, conservatively speeding up simulations by around three orders of magnitude compared to current methods that explicitly calculate the force on a tip model at each point in space.


Asunto(s)
Microscopía de Fuerza Atómica , Silanos/química , Agua/química , Microscopía de Fuerza Atómica/instrumentación , Simulación de Dinámica Molecular , Propiedades de Superficie , Termodinámica
13.
Proc Natl Acad Sci U S A ; 107(28): 12429-34, 2010 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-20615938

RESUMEN

Using density functional theory we investigate whether intrinsic defects in ice surface segregate. We predict that hydronium, hydroxide, and the Bjerrum L- and D-defects are all more stable at the surface. However, the energetic cost to create a D-defect at the surface and migrate it into the bulk crystal is smaller than its bulk formation energy. Absolute and relative segregation energies are sensitive to the surface structure of ice, especially the spatial distribution of protons associated with dangling hydrogen bonds. It is found that the basal plane surface of hexagonal ice increases the bulk concentration of Bjerrum defects, strongly favoring D-defects over L-defects. Dangling protons associated with undercoordinated water molecules are preferentially injected into the crystal bulk as Bjerrum D-defects, leading to a surface dipole that attracts hydronium ions. Aside from the disparity in segregation energies for the Bjerrum defects, we find the interactions between defect species to be very finely balanced; surface segregation energies for hydronium and hydroxide species and trapping energies of these ionic species with Bjerrum defects are equal within the accuracy of our calculations. The mobility of the ionic hydronium and hydroxide species is greatly reduced at the surface in comparison to the bulk due to surface sites with high trapping affinities. We suggest that, in pure ice samples, the surface of ice will have an acidic character due to the presence of hydronium ions. This may be important in understanding the reactivity of ice particulates in the upper atmosphere and at the boundary layer.


Asunto(s)
Hielo , Ácidos , Enlace de Hidrógeno , Hidróxidos , Iones/química , Protones , Agua/química
14.
J Chem Theory Comput ; 18(7): 4186-4202, 2022 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-35759470

RESUMEN

Time-dependent density functional theory has become state-of-the-art for describing photophysical and photochemical processes in extended materials because of its affordable cost. The inclusion of exact exchange was shown to be essential for the correct description of the long-range asymptotics of electronic interactions and thus a well-balanced description of valence, Rydberg, and charge-transfer excitations. Several approaches for an efficient treatment of exact exchange have been established for the ground state, while implementations for excited-state properties are rare. Furthermore, the high computational costs required for excited-state properties in comparison to ground-state computations often hinder large-scale applications on periodic systems with hybrid functional accuracy. We therefore propose two approximate schemes for improving computational efficiency for the treatment of exact exchange. Within the auxiliary density matrix method (ADMM), exact exchange is estimated using a relatively small auxiliary basis and the introduced basis set incompleteness error is compensated by an exchange density functional correction term. Benchmark results for a test set of 35 molecules demonstrate that the mean absolute error introduced by ADMM is smaller than 0.3 pm for excited-state bond lengths and in the range of 0.02-0.04 eV for vertical excitation, adiabatic excitation, and fluorescence energies. Computational timings for a series of covalent-organic frameworks demonstrate that a speed-up of at least 1 order of magnitude can be achieved for excited-state geometry optimizations in comparison to conventional hybrid functionals. The second method is to use a semiempirical tight binding approximation for both Coulomb and exchange contributions to the excited-state kernel. This simplified Tamm-Dancoff approximation (sTDA) achieves an accuracy comparable to approximated hybrid density functional theory when referring to highly accurate coupled-cluster reference data. We find that excited-state bond lengths deviate by 1.1 pm on average and mean absolute errors in vertical excitation, adiabatic excitation, and fluorescence energies are in the range of 0.2-0.5 eV. In comparison to ADMM-approximated hybrid functional theory, sTDA accelerates the computation of broad-band excitation spectra by 1 order of magnitude, suggesting its potential use for large-scale screening purposes.

15.
ACS Chem Neurosci ; 13(16): 2473-2482, 2022 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-35892278

RESUMEN

Aß oligomers play a central role in the neurodegeneration observed with Alzheimer's disease. Our laboratory has developed covalently stabilized trimers derived from residues 17-36 of Aß as model systems for studying Aß oligomers. In the current study, we apply the emerging techniques of fluorescence lifetime imaging microscopy (FLIM) and native mass spectrometry (native MS) to better understand the assembly and interactions of the oligomer model system 2AT-L in aqueous solutions and with cells. 2AT-L and fluorescently labeled 2AT-L analogues assemble in the membrane-like environment of SDS-PAGE, showing diffuse bands of oligomers in equilibrium. Native ion mobility-mass spectrometry (native IM-MS) of 2AT-L allows for the identification of discrete oligomers in solution and shows similar patterns of oligomer formation between 2AT-L and fluorescently labeled analogues. Fluorescence microscopy with SH-SY5Y cells reveals that fluorescently labeled 2AT-L analogues colocalize within lysosomes. FLIM studies with phasor analysis further elucidate the assembly of 2AT-L within cells and establish the occurrence of FRET, indicating the presence of oligomers within cells. Collectively, these multiple complementary techniques help better understand the complex behavior of the 2AT-L model system.


Asunto(s)
Enfermedad de Alzheimer , Neuroblastoma , Péptidos beta-Amiloides/química , Humanos , Espectrometría de Masas , Fragmentos de Péptidos/química , Agua/química
16.
Phys Chem Chem Phys ; 13(27): 12584-94, 2011 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-21666916

RESUMEN

We use computer modelling to investigate the mechanism of atomic-scale corrugation in frequency modulation atomic force microscopy imaging of inorganic surfaces in solution. Molecular dynamics simulations demonstrate that the forces acting on a model microscope tip result from the direct interaction between a tip and a surface, and forces entirely due to the water structure around both tip and surface. The observed force is a balance between largely repulsive potential energy changes as the tip approaches and the entropic gain when water is sterically prevented from occupying sites near the tip and surface. Only extremely sharp tips are likely to measure direct tip-surface interactions. An investigation into the dynamics of water confined between tip and surface shows that water diffusion can be slowed by at least two orders of magnitude compared to its rate in bulk solution.


Asunto(s)
Microscopía de Fuerza Atómica , Agua/química , Simulación de Dinámica Molecular , Soluciones/química , Propiedades de Superficie , Agua/fisiología
17.
J Thromb Thrombolysis ; 31(4): 401-6, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21107655

RESUMEN

The standard of care for STEMI PCI for the past decade has been aspirin, clopidogrel, heparin, and a glycoprotein IIbIIIa receptor inhibitor (GPI). A bivalirudin strategy was shown to be superior to a GPI strategy in the HORIZONS AMI trial for net adverse clinical events (combined MACE and bleeding). An increased risk of acute stent thrombosis in the bivalirudin arm may have prevented broader adoption of bivalirudin for this indication. We hypothesized that acute stent thrombosis risk could be ameliorated by a 2 h infusion of bivalirudin following STEMI PCI. We implemented a multicenter, prospective registry for all STEMI patients in Vermont treated at a single PCI center. Each patient was routinely pre-loaded with dual antiplatelet therapy and 75% received an unfractionated heparin bolus prior to PCI. The utilization of bivalirudin bolus and continued 2 h infusion after PCI was routine with GPI bailout optional. 128 consecutive STEMI patients underwent primary PCI from October 1, 2008 to September 30, 2009. 92% of primary PCI patients received bivalrudin during and after the procedure with a 9% rate of bail out GPI. There was one case of probable or definite acute stent thrombosis (0.7%), and this single case occurred despite use of bailout GPI. Despite the prolonged infusion of bivalirudin, major bleeding occurred in only 1.7% of STEMI patients. In conclusion, prolonging bivalirudin for 2 h after STEMI PCI may be a promising method to alleviate acute stent thrombosis risk without losing the bleeding complication benefit of the bivalirudin strategy.


Asunto(s)
Antitrombinas/administración & dosificación , Hirudinas/administración & dosificación , Infarto del Miocardio/terapia , Fragmentos de Péptidos/administración & dosificación , Sistema de Registros , Stents , Trombosis/prevención & control , Anciano , Antitrombinas/efectos adversos , Puente de Arteria Coronaria , Femenino , Hirudinas/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/efectos adversos , Inhibidores de Agregación Plaquetaria/administración & dosificación , Inhibidores de Agregación Plaquetaria/efectos adversos , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/efectos adversos , Factores de Tiempo
18.
Nano Lett ; 10(8): 2965-71, 2010 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-20608713

RESUMEN

Individual molecules of Co-Salen, a small chiral paramagnetic metal--organic Schiff base complex, were deposited on NaCl(001) and subsequently imaged with noncontact atomic force microscopy employing Cr coated tips in a cryogenic ultrahigh vacuum environment. Images were obtained in which both the position and orientation of the adsorbed molecules and the atomic structure of the surface are resolved simultaneously, enabling the determination of the exact adsorption site. Density functional theory calculations were used to identify the ionic sublattice resolved with the Cr tip and also to confirm the adsorption site and orientation of the molecule on the surface. These calculations show that the central Co atom of the molecule physisorbs on top of a Cl ion and is aligned along 110-directions in its lowest energy configuration. In addition, a local energy minimum exists along 100-directions. Due to the chirality of the molecule, two mirror symmetric configurations rotated by approximately +/-5 degrees away from these directions are energetically equivalent. The resulting 16 low energy configurations are observed in the experimental images.

19.
Glob Transit ; 3: 99-108, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34870136

RESUMEN

The demand of online remote working from home significantly increased in 2020/21 due to the Covid-19 pandemic. This unforeseen situation has forced individuals and organisations to rapidly train employees and adopt the use of on-line working styles, seeking to maintain the same level of productivity as working from the office. The paper outlines a survey conducted amongst people working from home to identify the challenges and opportunities this change in workstyle offers. At the beginning of the pandemic, many employees faced difficulties adapting to using online tools and combining their working hours with daily routines and family commitments. However, the results show that within a short period of time the respondents had managed to develop the necessary experience and knowledge for digital working utilising tools such as collaboration platforms and video conferencing. A large proportion of respondents recognised the advantage of eliminating travelling time when working remotely from home which also has a positive impact on the environment and CO2 emissions. However, some drawbacks have been identified such as the lack of face-to-face discussion and informal meetings during working days. The Self-Determination Theory is discussed within the context of this paper and it has been found that the theory could provide an explanation of the efficient and rapid adaptation of the technology be employees.

20.
Nat Food ; 2(9): 655-663, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37117479

RESUMEN

The recent development of true cost accounting (TCA) methodologies by various organizations has helped increase transparency in the food sector, but has also made it difficult to compare the results obtained through different methodologies. Here we review major TCA methodologies across five functional units that their assessment framework(s) apply to-namely product, organization, system, geography and investment. Our results show that the bulk of existing frameworks apply to products and/or organizations. According to publicly available documents and case studies published by the framework proponents, we found measurements of externality/dependency, the inclusion of economic, environmental and social effects, as well as the use of comparable metrics to be areas of general consensus; suggested indicators, monetization and aggregation emerged as areas of general divergence. The differences between TCA methodologies identified in this study indicate that collaboration between frameworks is key to their harmonization, ultimately making results more comparable and facilitating engagement in TCA.

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