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1.
Phys Chem Chem Phys ; 25(38): 25993-26005, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37729436

RESUMO

As part of an on-going programme of development of an aniline synthesis catalyst suitable for operation at elevated temperatures, the geometry of the adsorption complex for nitrobenzene on a 5 wt% Pd/Al2O3 catalyst is investigated by infrared (IR) spectroscopy. Via an appreciation of the reduced site symmetry resulting from adsorption, application of the metal surface selection rule, and observation of in-plane modes only, the adsorption complex (Pd-nitrobenzene) at 28 °C is assigned as occurring vertically or tilted with respect to the metal surface, adopting Csσv(yz) symmetry. Moreover, adsorption occurs via a single Pd-O bond. Single molecule DFT calculations and simulated IR spectra assist vibrational assignments but indicate a parallel adsorption geometry to be energetically favourable. The contradiction between calculated and observed structures is attributed to the DFT calculations corresponding to an isolated molecule adsorption complex, while IR spectra relate to multi molecule adsorption that is encountered during sustained catalytic turnover. Residual hydrogen from the catalyst reduction stage leads to aniline formation on the Pd surface at low nitrobenzene coverages but, on increasing nitrobenzene exposure, the aniline is forced on to the alumina support. A reaction scheme is proposed whereby the nitrobenzene adsorption geometry is inherently linked to the high aniline selectivity observed for Pd/Al2O3 catalysts.

2.
Exp Eye Res ; 225: 109283, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36273577

RESUMO

Sex steroids play a role in regulation of tear film function and may exert their action locally at the ocular surface. However, measurement of sex steroids in tears is difficult due to small-volume tear samples and very low concentrations of the hormones. This short communication highlights what has been achieved to date in the analysis of tear sex steroids using ultra-performance LC-MS (UPLC-MS) as previously published, and reports further and more recent investigations toward optimising mass spectrometry method sensitivity and accuracy. The published UPLC-MS method successfully measured progesterone, androsterone glucuronide and 5α-androstane-3α,17ß-diol in pooled basal tears of postmenopausal women, and fourteen sex steroid standards in methanol. Limitations included sub-optimal limits of detection (LOD) and lower limits of quantification (LLOQ) for some analytes (particularly oestrogens), exclusion of sample matrix effects and no use of internal standards. This update reports on further experiments carried out to improve sensitivity and accuracy. Sample matrix effects, internal standard spiking, and derivatisation with dansyl chloride and oximes were investigated. Dansylation significantly improved the LOD and LLOQ of oestrogens and their metabolites, by a factor of 10 for oestradiol and a factor of 5 for oestrone, but sensitivity of this updated method is not sufficient however for analysis of these oestrogens in human tears. Using gas chromatography-mass spectrometry (GC-MS) as an alternative technique to LC-MS, improved sensitivity for derivatised oestradiol is reported. This work demonstrates the need to develop higher sensitivity methods and points researchers towards specific MS ionisation techniques for future analysis of sex steroids in tears, in order to progress current understanding of the role of sex steroids in tear function and dry eye.


Assuntos
Hormônios Esteroides Gonadais , Espectrometria de Massas em Tandem , Humanos , Feminino , Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas em Tandem/métodos , Estrogênios , Estradiol
3.
J Med Internet Res ; 23(7): e26582, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34255690

RESUMO

BACKGROUND: Diagnostics in many low- and middle-income countries are conducted through centralized laboratory networks. Samples are collected from patients at remote point-of-care health facilities, and diagnostic tests are performed at centralized laboratories. Sample transportation systems that deliver diagnostic samples and test results are crucial for timely diagnosis and treatment in such diagnostic networks. However, they often lack the timely and accurate data (eg, the quantity and location of samples prepared for collection) required for efficient operation. OBJECTIVE: This study aims to demonstrate the feasibility, adoption, and accuracy of a distributed data collection system that leverages basic mobile phone technology to gather reports on the quantity and location of patient samples and test results prepared for delivery in the diagnostic network of Malawi. METHODS: We designed a system that leverages unstructured supplementary service data (USSD) technology to enable health workers to submit daily reports describing the quantity of transportation-ready diagnostic samples and test results at specific health care facilities, free of charge with any mobile phone, and aggregate these data for sample transportation administrators. We then conducted a year-long field trial of this system in 51 health facilities serving 3 districts in Malawi. Between July 2019 and July 2020, the participants submitted daily reports containing the number of patient samples or test results designated for viral load, early infant diagnosis, and tuberculosis testing at each facility. We monitored daily participation and compared the submitted USSD reports with program data to assess system feasibility, adoption, and accuracy. RESULTS: The participating facilities submitted 37,771 reports over the duration of the field trial. Daily facility participation increased from an average of 50% (26/51) in the first 2 weeks of the trial to approximately 80% (41/51) by the midpoint of the trial and remained at or above 80% (41/51) until the conclusion of the trial. On average, more than 80% of the reports submitted by a facility for a specific type of sample matched the actual number of patient samples collected from that facility by a courier. CONCLUSIONS: Our findings suggest that a USSD-based system is a feasible, adoptable, and accurate solution to the challenges of untimely, inaccurate, or incomplete data in diagnostic networks. Certain design characteristics of our system, such as the use of USSD, and implementation characteristics, such as the supportive role of the field team, were necessary to ensure high participation and accuracy rates without any explicit financial incentives.


Assuntos
Telefone Celular , Sistemas de Dados , Humanos , Malaui , Sistemas Automatizados de Assistência Junto ao Leito , Carga Viral
4.
Angew Chem Int Ed Engl ; 60(3): 1212-1219, 2021 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-32978789

RESUMO

RuII compounds are widely used in catalysis, photocatalysis, and medical applications. They are usually obtained in a reductive environment as molecular O2 can oxidize RuII to RuIII and RuIV . Here we report the design, identification and evolution of an air-stable surface [bipy-RuII (CO)2 Cl2 ] site that is covalently mounted onto a polyphenylene framework. Such a RuII site was obtained by reduction of [bipy-RuIII Cl4 ]- with simultaneous ligand exchange from Cl- to CO. This structural evolution was witnessed by a combination of in situ X-ray and infrared spectroscopy studies. The [bipy-RuII (CO)2 Cl2 ] site enables oxidation of CO with a turnover frequency of 0.73×10-2  s-1 at 462 K, while the RuIII site is completely inert. This work contributes to the study of structure-activity relationship by demonstrating a practical control over both geometric and electronic structures of single-site catalysts at molecular level.

5.
Surg Endosc ; 34(8): 3408-3413, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31506794

RESUMO

BACKGROUND: Left hemicolectomy and complicated sigmoid colectomy require an anastomosis between the transverse colon and rectum. Generous mobilization will typically allow the colon to reach to the rectum. However, despite full mobilization of the splenic flexure and extensive work on the mesentery, there are cases in which reach to the pelvis is still an issue. Retroileal routing of the colon is one technique for overcoming such a reach problem and achieving a tension-free anastomosis. Performing retroileal routing using laparoscopic techniques has been reported rarely, and to date, there are no data on this technique when performed in a hand-assisted laparoscopic fashion. This study aimed to describe the feasibility of doing a retroileal routing using a hand-assisted laparoscopic technique. METHODS: This was a retrospective chart review of patients who underwent a colon or rectal resection, either open or laparoscopic, with a pelvic anastomosis, by a single colorectal surgeon at an academic institution between 2008 and 2015 with a focus on the immediate and long-term postoperative complications, estimated blood loss, and operating room time for patients having an operation that included retroileal routing for construction of a colorectal anastomosis. RESULTS: A total of 340 patients fit inclusion criteria and of these, 13 underwent hand-assisted laparoscopic procedures with retroileal routing of the proximal colon to the colorectal anastomosis. Postoperative morbidity included intubation for CO2 retention in one patient and a RLL effusion in another patient; there were no anastomotic leaks. Long-term morbidities included two ventral hernias at 2 years postoperatively. Mean operating room time was 208 min. There were no 30- or 90-day mortalities. CONCLUSIONS: Hand-assisted laparoscopic retroileal routing is a feasible and safe technique in accomplishing a tension-free colorectal anastomosis when proximal colon length makes standard routing of the colon to the rectum an issue.


Assuntos
Anastomose Cirúrgica/métodos , Colectomia/métodos , Laparoscopia Assistida com a Mão/métodos , Centros Médicos Acadêmicos , Idoso , Idoso de 80 Anos ou mais , Colo/cirurgia , Colo Transverso/cirurgia , Feminino , Humanos , Íleo/patologia , Íleo/cirurgia , Masculino , Mesentério/patologia , Mesentério/cirurgia , Pessoa de Meia-Idade , Duração da Cirurgia , Pelve , Complicações Pós-Operatórias/cirurgia , Protectomia , Reto/cirurgia , Estudos Retrospectivos
6.
Angew Chem Int Ed Engl ; 59(34): 14331-14335, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32432351

RESUMO

We report the design and preparation of multifunctional hybrid nanomaterials through the stabilization of gold nanoparticles with thiol-functionalised hybrid organic-inorganic polyoxometalates (POMs). The covalent attachment of the hybrid POM forms new nanocomposites that are stable at temperatures and pH values which destroy analogous electrostatically functionalised nanocomposites. Photoelectrochemical analysis revealed the unique photochemical and redox properties of these systems.

7.
Exp Eye Res ; 179: 168-178, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30448340

RESUMO

Sex steroids impact regulation of the ocular surface tissues and thus influence dry eye. Most tissues in the human body synthesise and metabolise active sex steroids at levels required by the tissue. This is likely to also be the case for humans in ocular surface tissues. This study investigated the presence and quantities of selected sex steroids, in addition to sex steroid precursors and metabolites, in human tears. Detection of sex steroids in tears is challenging due to trace level analyte concentrations and low volumes of available tears. Immunoassays have previously been employed to assess sex steroids in tears, however, this approach only allows a single analyte to be measured and can overestimate concentrations. This study evaluated ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS) and tandem mass spectrometry (MS/MS) methods for the concurrent detection and estimation of fourteen sex steroid and metabolite compounds in human tears. Basal tears were collected and pooled from 5 healthy pre-menopausal women (total 100 µL). Following protein precipitation and centrifuging, extract volumes equivalent to 14 µL of pooled tears were analysed. A Thermo Scientific Q Exactive™ Plus MS was used to compare novel high-resolution MS atmospheric pressure chemical ionization (APCI) and electrospray ionisation (ESI) methods for detection of fourteen target sex steroids, including dehydroepiandrosterone-sulphate (DHEAS), testosterone, oestradiol and their metabolites, using standards and pooled tears. The MS was programmed to switch between positive and negative polarity ionization modes at designated times through the UPLC run, in order to detect each analyte at optimal sensitivity. Analytes were analysed using APCI in standard mixtures at concentrations of 0.1, 0.3, 1, 3, 10, 30, 100 and 1000 pg/mL, per component, to determine the limits of detection (LOD) and quantification. Both parallel reaction monitoring (PRM) MS/MS and selected ion monitoring (SIM) MS, were evaluated by plotting narrow range mass-to-charge ratio (m/z) chromatograms for each analyte. An APCI UPLC-MS method to simultaneously measure 14 sex steroids using standards was successfully developed following comparative evaluation of all available LC-MS techniques. Preliminary experiments found APCI to be more sensitive than ESI using standards. Narrow m/z range SIM MS resulted in better sensitivity, in tear samples, than PRM. One sex steroid and two androgen metabolites were detected, with the developed APCI UPLC-MS method, and their concentrations estimated in human tears that had been extracted with a protein crash. Progesterone, androsterone-glucuronide (ADT-G) and 3αDiol-G were successfully detected in the tear extract and their concentrations in the pooled tear sample were estimated (with 95% confidence intervals) to be 0.10 ±â€¯0.03 pg/µL, 30.9 ±â€¯18.3 pg/µL and 9.8 ±â€¯4.3 pg/µL respectively. The concentrations of the remaining 11 sex steroids in the tear sample were below the LODs of the method. This work shows that high mass resolution UPLC-MS can detect certain sex steroids and metabolites in tears, but that sensitivity of the technique and the low available tear volumes limit its application to a broader range of sex steroids. The investigation of sex steroids in tears and ocular surface tissue will aid understanding of the influence of sex steroids on ocular surface tissues facilitating better targeted treatment for dry eye.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Proteínas do Olho/análise , Hormônios Esteroides Gonadais/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Lágrimas/química , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
8.
Faraday Discuss ; 208(0): 67-85, 2018 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-29850700

RESUMO

The interaction of CO with an attapulgite-supported Cu(ii)Cl2 catalyst has been examined in a micro-reactor arrangement. CO exposure to the dried, as-received catalyst at elevated temperatures leads to the formation of CO2 as the only identifiable product. However, phosgene production can be induced by using a catalyst pre-treatment where the supported Cu(ii)Cl2 sample is exposed to a diluted stream of chlorine. Subsequent CO exposure at ∼370 °C then leads to phosgene production. In order to investigate the origins of this atypical set of reaction characteristics, a series of X-ray absorption experiments were performed that were supplemented by DFT calculations. XANES measurements establish that at the elevated temperatures connected with phosgene formation, the catalyst is comprised of Cu+ and a small amount of Cu2+. Moreover, the data show that unique to the chlorine pre-treated sample, CO exposure at elevated temperature results in a short-lived oxidation of the copper. On the basis of calculated CO adsorption energies, DFT calculations indicate that a mixed Cu+/Cu2+ catalyst is required to support CO chemisorption.

9.
Faraday Discuss ; 197: 447-471, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28194458

RESUMO

A ZSM-5 catalyst is examined in relation to the methanol-to-hydrocarbon (MTH) reaction as a function of reaction temperature and time-on-stream. The reaction profile is characterised using in-line mass spectrometry. Furthermore, the material contained within a catch-pot downstream from the reactor is analysed using gas chromatography-mass spectrometry. For a fixed methanol feed, reaction conditions are selected to define various stages of the reaction coordinate: (i) initial methanol adsorption at a sub-optimum reaction temperature (1 h at 200 °C); (ii) initial stages of reaction at an optimised reaction temperature (1 h at 350 °C); (iii) steady-state operation at an optimised reaction temperature (3 days at 350 °C); and (iv) accelerated ageing (3 days at 400 °C). Post-reaction, the catalyst samples are analysed ex situ by a combination of temperature-programmed oxidation (TPO) and spectroscopically by electron paramagnetic resonance (EPR), diffuse-reflectance infrared and inelastic neutron scattering (INS) spectroscopies. The TPO measurements provide an indication of the degree of 'coking' experienced by each sample. The EPR measurements detect aromatic radical cations. The IR and INS measurements reveal the presence of retained hydrocarbonaceous species, the nature of which are discussed in terms of the well-developed 'hydrocarbon pool' mechanism. This combination of experimental evidence, uniquely applied to this reaction system, establishes the importance of retained hydrocarbonaceous species in effecting the product distribution of this economically relevant reaction system.

10.
Phys Chem Chem Phys ; 19(40): 27191-27203, 2017 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-28926035

RESUMO

We report a detailed density functional theory (DFT) study in conjunction with extended X-ray absorption fine structure (EXAFS) experiments on the geometrical and local electronic properties of Cu adatoms and Cu(ii) ions in presence of water molecules and of CuO nanoclusters on the CeO2(110) surface. Our study of (CuO)n(=1,2&4) clusters on CeO2(110) shows that based on the Cu-O environment, the geometrical properties of these clusters may vary and their presence may lead to relatively high localization of charge on the exposed surfaces. We find that in the presence of an optimum concentration of water molecules, Cu has a square pyramidal geometry, which agrees well with our experimental findings; we also find that Cu(ii) facilitates water adsorption on the CeO2(110) surface. We further show that a critical concentration of water molecules is required for the hydrolysis of water on Cu(OH)2/CeO2(110) and on pristine CeO2(110) surfaces.

11.
Angew Chem Int Ed Engl ; 56(44): 13596-13600, 2017 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-28841767

RESUMO

Artificial metalloenzymes (ArMs) are hybrid catalysts that offer a unique opportunity to combine the superior performance of natural protein structures with the unnatural reactivity of transition-metal catalytic centers. Therefore, they provide the prospect of highly selective and active catalytic chemical conversions for which natural enzymes are unavailable. Herein, we show how by rationally combining robust site-specific phosphine bioconjugation methods and a lipid-binding protein (SCP-2L), an artificial rhodium hydroformylase was developed that displays remarkable activities and selectivities for the biphasic production of long-chain linear aldehydes under benign aqueous conditions. Overall, this study demonstrates that judiciously chosen protein-binding scaffolds can be adapted to obtain metalloenzymes that provide the reactivity of the introduced metal center combined with specifically intended product selectivity.


Assuntos
Aldeídos/química , Materiais Biomiméticos/química , Metaloproteínas/química , Proteína Multifuncional do Peroxissomo-2/química , Fosfinas/química , Ródio/química , Catálise , Humanos , Modelos Moleculares
12.
Angew Chem Int Ed Engl ; 56(32): 9351-9355, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28623870

RESUMO

Three recurring hypotheses are often used to explain the effect of non-thermal plasmas (NTPs) on NTP catalytic hybrid reactions; namely, modification or heating of the catalyst or creation of new reaction pathways by plasma-produced species. NTP-assisted methane (CH4 ) oxidation over Pd/Al2 O3 was investigated by direct monitoring of the X-ray absorption fine structure of the catalyst, coupled with end-of-pipe mass spectrometry. This in situ study revealed that the catalyst did not undergo any significant structural changes under NTP conditions. However, the NTP did lead to an increase in the temperature of the Pd nanoparticles; although this temperature rise was insufficient to activate the thermal CH4 oxidation reaction. The contribution of a lower activation barrier alternative reaction pathway involving the formation of CH3 (g) from electron impact reactions is proposed.

13.
Faraday Discuss ; 188: 115-29, 2016 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-27067956

RESUMO

The performance of Mo-enriched, bulk ferric molybdate, employed commercially for the industrially important reaction of the selective oxidation of methanol to formaldehyde, is limited by a low surface area, typically 5-8 m(2) g(-1). Recent advances in the understanding of the iron molybdate catalyst have focused on the study of MoOx@Fe2O3 (MoOx shell, Fe2O3 core) systems, where only a few overlayers of Mo are present on the surface. This method of preparing MoOx@Fe2O3 catalysts was shown to support an iron molybdate surface of higher surface area than the industrially-favoured bulk phase. In this research, a MoOx@Fe2O3 catalyst of even higher surface area was stabilised by modifying a haematite support containing 5 wt% Al dopant. The addition of Al was an important factor for stabilising the haematite surface area and resulted in an iron molybdate surface area of ∼35 m(2) g(-1), around a 5 fold increase on the bulk catalyst. XPS confirmed Mo surface-enrichment, whilst Mo XANES resolved an amorphous MoOx surface monolayer supported on a sublayer of Fe2(MoO4)3 that became increasingly extensive with initial Mo surface loading. The high surface area MoOx@Fe2O3 catalyst proved amenable to bulk characterisation techniques; contributions from Fe2(MoO4)3 were detectable by Raman, XAFS, ATR-IR and XRD spectroscopies. The temperature-programmed pulsed flow reaction of methanol showed that this novel, high surface area catalyst (3ML-HSA) outperformed the undoped analogue (3ML-ISA), and a peak yield of 94% formaldehyde was obtained at ∼40 °C below that for the bulk Fe2(MoO4)3 phase. This work demonstrates how core-shell, multi-component oxides offer new routes for improving catalytic performance and understanding catalytic activity.

14.
Phys Chem Chem Phys ; 18(26): 17303-10, 2016 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-27264938

RESUMO

The increased demand for bulk hydrocarbons necessitates research into increasingly sustainable, energy-efficient catalytic processes. Owing to intricately designed structure-property correlations, SAPO-34 has become established as a promising material for the low temperature ethanol dehydration to produce ethylene. However, further optimization of this process requires a precise knowledge of the reaction mechanism at a molecular level. In order to achieve this a range of spectroscopic characterization techniques are required to probe both the interaction with the active site, and also the wider role of the framework. To this end we employ a combination of in situ infra-red and neutron scattering techniques to elucidate the influence of the surface ethoxy species in the activation of both diethyl ether and ethanol, towards the improved formation of ethylene at low temperatures. The combined conclusions of these studies is that the formation of ethylene is the rate determining step, which is of fundamental importance towards the development of this process and the introduction of bio-ethanol as a viable feedstock for ethylene production.

15.
J Dent ; 147: 105021, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38679135

RESUMO

OBJECTIVES: (i) To identify suitable strategies and opportunities to embed Environmental Sustainability (ES) within an existing Oral Health Professional (OHP) curriculum through a series of focus groups with students and academic staff and (ii) To create high-level evidence-based and subject-specific ES content through an approach grounded in evidence and collaboration with key stakeholders in OHP education. METHODS: Focus groups were used to explore academic staff and student views on appropriate teaching and assessment methods for ES. Content statements were developed from an extensive literature search, mapped to curriculum subjects, and validated through consultation with students, discipline-experts and education-experts. RESULTS: Five themes were identified from the focus groups: ES transcends all disciplines of dentistry and oral healthcare; baseline knowledge transmission with relevant practical application; viewing and modifying existing teaching and assessment events through a different lens; normalising the topic of ES to support attitude and behaviour change and safeguarding against misinformation and disinformation. Forty-four content statements were developed and mapped to nineteen curriculum subjects. CONCLUSIONS: This study identifies for the first time a comprehensive strategy for the inclusion and delivery of ES (method and content) in the curriculum. A novel method to define and map curriculum content has been explored and validated using a range of complementary methodologies. A comprehensive and robust list of evidence-based and subject-specific educational content statements have been defined in the field of Environmental Sustainability in dentistry and oral healthcare. CLINICAL SIGNIFICANCE: Oral healthcare has a significant environmental impact, the key to all mitigation strategies is educating the profession at all levels.


Assuntos
Currículo , Educação em Odontologia , Grupos Focais , Humanos , Educação em Odontologia/métodos , Conservação dos Recursos Naturais , Estudantes de Odontologia/psicologia , Saúde Bucal/educação , Atitude do Pessoal de Saúde
16.
PLoS One ; 19(5): e0293691, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38753603

RESUMO

Capturing human locomotion in nearly any environment or context is becoming increasingly feasible with wearable sensors, giving access to commonly encountered walking conditions. While important in expanding our understanding of locomotor biomechanics, these more variable environments present challenges to identify changes in data due to person-level factors among the varying environment-level factors. Our study examined foot-specific biomechanics while walking on terrain commonly encountered with the goal of understanding the extent to which these variables change due to terrain. We recruited healthy adults to walk at self-selected speeds on stairs, flat ground, and both shallow and steep sloped terrain. A pair of inertial measurement units were embedded in both shoes to capture foot biomechanics while walking. Foot orientation was calculated using a strapdown procedure and foot trajectory was determined by double integrating the linear acceleration. Stance time, swing time, cadence, sagittal and frontal orientations, stride length and width were extracted as discrete variables. These data were compared within-participant and across terrain conditions. The physical constraints of the stairs resulted in shorter stride lengths, less time spent in swing, toe-first foot contact, and higher variability during stair ascent specifically (p<0.05). Stride lengths increased when ascending compared to descending slopes, and the sagittal foot angle at initial contact was greatest in the steep slope descent condition (p<0.05). No differences were found between conditions for horizontal foot angle in midstance (p≥0.067). Our results show that walking on slopes creates differential changes in foot biomechanics depending on whether one is descending or ascending, and stairs require different biomechanics and gait timing than slopes or flat ground. This may be an important factor to consider when making comparisons of real-world walking bouts, as greater proportions of one terrain feature in a data set could create bias in the outcomes. Classifying terrain in unsupervised walking datasets would be helpful to avoid comparing metrics from different walking terrain scenarios.


Assuntos
, Locomoção , Caminhada , Humanos , Pé/fisiologia , Masculino , Adulto , Feminino , Fenômenos Biomecânicos , Caminhada/fisiologia , Locomoção/fisiologia , Marcha/fisiologia , Adulto Jovem
17.
J Am Chem Soc ; 135(26): 9849-56, 2013 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-23646935

RESUMO

The influence of the metal ion in the mesoporous metal trimesate MIL-100(Al(3+), Cr(3+), Fe(3+), V(3+)) on the adsorptive removal of N/S-heterocyclic molecules from fuels has been investigated by combining isotherms for adsorption from a model fuel solution with microcalorimetric and IR spectroscopic characterizations. The results show a clear influence of the different metals (Al, Fe, Cr, V) on the affinity for the heterocyclic compounds, on the integral adsorption enthalpies, and on the uptake capacities. Among several factors, the availability of coordinatively unsaturated sites and the presence of basic sites next to the coordinative vacancies are important factors contributing to the observed affinity differences for N-heterocyclic compounds. These trends were deduced from IR spectroscopic observation of adsorbed indole molecules, which can be chemisorbed coordinatively or by formation of hydrogen bonded species. On the basis of our results we are able to propose an optimized adsorbent for the deep and selective removal of nitrogen contaminants out of fuel feeds, namely MIL-100(V).


Assuntos
Alumínio/química , Combustíveis Fósseis , Compostos Heterocíclicos/isolamento & purificação , Ferro/química , Metais/química , Compostos Organometálicos/química , Vanádio/química , Compostos Heterocíclicos/química , Íons/química , Estrutura Molecular , Tamanho da Partícula , Porosidade , Propriedades de Superfície
19.
PeerJ ; 11: e15454, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37547726

RESUMO

In natural and agricultural systems, the plant microbiome-the microbial organisms associated with plant tissues and rhizosphere soils-has been shown to have important effects on host physiology and ecology, yet we know little about how these plant-microbe relationships play out in urban environments. Here we characterize the composition of fungal communities associated with living leaves of one of the most common sidewalk trees in the city of San Francisco, California. We focus our efforts on endophytic fungi (asymptomatic microfungi that live inside healthy leaves), which have been shown in other systems to have large ecological effects on the health of their plant hosts. Specifically, we characterized the foliar fungal microbiome of Metrosideros excelsa (Myrtaceae) trees growing in a variety of urban environmental conditions. We used high-throughput culturing, PCR, and Sanger sequencing of the internal transcribed spacer nuclear ribosomal DNA (ITS nrDNA) region to quantify the composition and structure of fungal communities growing within healthy leaves of 30 M. excelsa trees from six distinct sites, which were selected to capture the range of environmental conditions found within city limits. Sequencing resulted in 854 high-quality ITS sequences. These sequences clustered into 85 Operational Taxonomic Units (97% OTUs). We found that these communities encompass relatively high alpha (within) and beta (between-site) diversity. Because the communities are all from the same host tree species, and located in relatively close geographical proximity to one another, these analyses suggest that urban environmental factors such as heat islands or differences in vegetation or traffic density (and associated air quality) may potentially be influencing the composition of these fungal communities. These biogeographic patterns provide evidence that plant microbiomes in urban environments can be as dynamic and complex as their natural counterparts. As human populations continue to transition out of rural areas and into cities, understanding the factors that shape environmental microbial communities in urban ecosystems stands to become increasingly important.


Assuntos
Fungos não Classificados , Microbiota , Humanos , Endófitos/genética , Cidades , São Francisco , Temperatura Alta , Plantas/microbiologia , Árvores/microbiologia
20.
Vaccines (Basel) ; 11(7)2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37515074

RESUMO

COVID-19 caused significant morbidity and mortality amongst ethnic minority groups, but vaccine uptake remained lower than non-minoritised groups. Interventions to increase vaccine uptake among ethnic minority communities are crucial. This systematic review synthesises and evaluates behaviour change techniques (BCTs) in interventions to increase vaccination uptake in ethnic minority populations. We searched five databases and grey literature sources. From 7637 records identified, 23 studies were included in the review. Interventions were categorised using the Behaviour Change Wheel (BCW) and Behaviour Change Taxonomy v1. Vaccines included influenza, pertussis, tetanus, diphtheria, meningitis and hepatitis. Interventions were primarily delivered in health centres/clinics and community settings. Six BCW intervention functions and policy categories and 26 BCTs were identified. The main intervention functions used were education, persuasion and enablement. Overall, effective interventions had multi-components and were tailored to specific populations. No strong evidence was observed to recommend specific interventions, but raising awareness and involvement of community organisations was associated with positive effects. Several strategies are used to increase vaccine uptake among ethnic minority communities; however, these do not address all issues related to low vaccine acceptance. There is a strong need for an increased understanding of addressing vaccine hesitancy among ethnic minority groups.

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