Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
2.
Eur J Surg Oncol ; 49(11): 107087, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37793302

RESUMO

BACKGROUND: Extended right hemicolectomy (ERHC) or left hemicolectomy (LHC) are accepted as the standard-of-care for colonic tumours of the splenic flexure. Lymphatic drainage at this site is poorly defined and subject to significant heterogeneity. Nevertheless, emerging evidence demonstrates the potential oncological safety of segmental splenic flexure colectomy (SFC). AIM: To perform a systematic review and network meta-analysis (NMA) to compare outcomes following ERHC, LHC and SFC for splenic flexure tumours (SFTs). METHODS: A systematic review was performed as per PRISMA guidelines. NMA was performed using R Shiny and Netmeta packages. RESULTS: A total of 13 studies, involving 6176 patients (ERHC n = 785; LHC n = 1527; SFC n = 3864) were included in the NMA. There was no difference in overall survival (OS) (SFC vs LHC Hazard Ratio [HR] 1.0, 95% Credible Interval [CrI] 0.76,1.34; SFC vs ERHC HR 1.18, 95% CrI 0.85,1.58) between the groups. SFC had a shorter operation time (Mean 176.37 min; Mean Difference [MD] SFC vs LHC 20.34 min 95% CrI 10.9, 29.97; SFC vs ERHC MD 22.19 95% CrI 11.09, 33.29) but also had a lower average lymph node yield (LNY) compared with ERHC (MD 7.15, 95% CrI 5.71, 8.60). ERHC had a significantly higher incidence of post-operative ileus (Odds Ratio [OR] 3.47, 95% CrI 1.11, 10.84). There was also no difference observed for minimally invasive approaches, anastomotic leak rate, perioperative mortality, reoperation rates or length of stay. CONCLUSIONS: While SFC may allow for reduced operative duration and improved bowel function postoperatively. SFC, LHC, ERHC are all acceptable approaches for curative resection of cancers of the splenic flexure, with no difference in OS observed. Thus, surgeon preference and candidate-specific factors will likely determine the management of SFTs.


Assuntos
Colo Transverso , Neoplasias do Colo , Neoplasias Colorretais , Febre Grave com Síndrome de Trombocitopenia , Neoplasias Esplênicas , Humanos , Colo Transverso/cirurgia , Colo Transverso/patologia , Metanálise em Rede , Febre Grave com Síndrome de Trombocitopenia/patologia , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/patologia , Neoplasias do Colo/cirurgia
3.
J Phys Chem C Nanomater Interfaces ; 126(25): 10378-10387, 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35800675

RESUMO

As part of a program to investigate aspects of surface chemistry relevant to methyl chloride synthesis catalysis, the interaction of methanol with η-alumina doped with either CsCl or KCl in the range 0.01-1.0 mmol g(cat) -1 is investigated by a combination of diffuse reflectance infrared Fourier transform spectroscopy and temperature-programed desorption (TPD). Infrared spectra (IR) recorded at 293 K show that increasing the concentration of the group 1 metal chloride progressively decreases the surface concentration of associatively chemisorbed methanol and changes the environment in which the adsorbed methanol resides. For CsCl concentrations of ≥0.6 mmol g(cat) -1, chemisorbed methoxy species dominate the IR spectrum, while TPD studies show that the amount of methanol adsorbed onto the surface, and subsequently desorbed unchanged, changes relatively little. In the TPD experiments, some of the adsorbed methanol reacts to give dimethyl ether (DME) which then desorbs; for dopant concentrations of 1.0 mmol g(cat) -1, DME formation is suppressed to below the limit of detection. Unexpectedly, the presence of formate species generated at 293 K is also observed spectroscopically, characterized by a νasym(COO) mode which exhibits a hypsochromic shift relative to potassium formate; surface concentrations of formate are higher at higher loadings of group 1 metal chloride. Temperature-programed IR spectroscopy shows that the room-temperature formate species desorbs, decomposes, or migrates on warming to 653 K. Thermal ramping of the methanol-saturated surface also results in formate production but one that exhibits an IR profile in agreement with earlier observations and literature values. Increasing the concentrations of the group 1 metal chloride progressively decreases the presence of the thermally induced formate moiety. The study not only reinforces the concept of group 1 metal chloride additives progressively rendering ineffective those Lewis acid sites present at the η-alumina surface which convey discrete reaction characteristics [e.g., (i) dimerization of methanol to form DME and (ii) an activated methoxy → formate transition] but also suggests the generation of reactive sites not present in the undoped alumina.

5.
J Shoulder Elbow Surg ; 31(4): 813-818, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34687918

RESUMO

BACKGROUND: The purpose of this study was to compare the preoperative magnetic resonance arthrography findings in patients who underwent glenohumeral stabilization with a history of primary instability, recurrent instability, or failed stabilization. METHODS: All patients who presented with glenohumeral instability and underwent stabilization performed by a single surgeon in our institution between 2008 and 2020 were considered for inclusion in this study. The magnetic resonance arthrography findings of all patients were recorded. Imaging findings were compared between patients with primary instability, those with recurrent instability, and those with failed prior stabilization. P < .05 was considered statistically significant. RESULTS: Overall, 871 patients were included, of whom 814 (93.5%) were male patients; the mean age was 23.1 years (range, 13-57 years). There were 200 patients with primary instability, 571 with recurrent instability, and 100 who required revision stabilization surgery, with no significant differences in demographic characteristics between the groups. A significantly higher amount of glenoid bone loss was noted in patients with recurrent instability (43.4%) and failed prior stabilization (56%) than in those with primary instability (26.5%) (P < .0001). Additionally, a significantly higher number of Hill-Sachs lesions were observed in patients with recurrent instability (70.1%) and failed prior stabilization (89%) than in those with primary instability (67.5%) (P < .0001). We found no significant differences between the groups regarding articular cartilage damage, glenolabral articular disruption, anterior labral periosteal sleeve avulsion, humeral avulsion of the glenohumeral ligaments, or superior labral anterior-posterior tears (P > .05). CONCLUSION: Patients presenting for stabilization with recurrent instability or following a failed stabilization procedure have higher rates of glenohumeral bone loss than those with primary instability. Therefore, stabilization of primary instability, particularly in high-functioning athletes with a view to preventing recurrence, may reduce the overall progression of glenohumeral bone loss and potential subsequent inferior clinical outcomes.


Assuntos
Atletas , Instabilidade Articular , Articulação do Ombro , Adulto , Artroscopia/métodos , Lesões de Bankart/cirurgia , Humanos , Instabilidade Articular/diagnóstico por imagem , Instabilidade Articular/patologia , Instabilidade Articular/cirurgia , Masculino , Recidiva , Luxação do Ombro/complicações , Luxação do Ombro/diagnóstico por imagem , Luxação do Ombro/cirurgia , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/patologia , Articulação do Ombro/cirurgia , Adulto Jovem
6.
Surgeon ; 19(6): e507-e511, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33451875

RESUMO

BACKGROUND: The internet is an important source of information for patients undergoing surgery. Multiple studies have identified inappropriately high reading levels of patient information online. The average reading level in the United States is 7-8th grade. Multiple organisations have recommended that patient information not exceed 6th grade level. This study aims to evaluate the reading levels and quality of information regarding ankle fusion surgery online. METHODS: Google, Bing and Yahoo were searched (MeSH "ankle fusion", "ankle arthrodesis") and the top 30 URLs analysed. Readability was assessed using an online readability calculator to produce 3 scores (Gunning FOG, Flesch Kincaid Grade and Flesch Reading Ease). Quality was assessed using a HONcode detection web-extension and the JAMA benchmark criteria. RESULTS: Ninety-eight webpages were identified. The mean Flesch Kincaid Grade level was 9.24 ± 2.33 (95% CI 8.78-9.71). The mean Gunning FOG grade was 10.88 ± 3.1 (95% CI 10.26-11.5). The mean Flesch Reading Ease score was 49.88 ± 14.46 (95% CI 46.98-52.78). 7 webpages were at or below the 6th grade reading level. The mean JAMA score was 1.34 ± 1.32 out of 4 (95% CI 1.07-1.6). 14 websites were HONcode accredited. CONCLUSION: The overall readability of medical information online is too high for the average patient. Given the important role that health literacy provides in patient reported outcomes, improving the readability and quality of these materials is imperative. Awareness by the general public is essential for them to critically appraise the information they receive online.


Assuntos
Compreensão , Letramento em Saúde , Tornozelo , Artrodese , Humanos , Internet , Estados Unidos
7.
RSC Adv ; 9(5): 2608-2617, 2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35520506

RESUMO

In order to examine fundamental processes connected with the use of an unpromoted iron based Fischer-Tropsch synthesis (FTS) catalyst, model studies examining the temporal formation of hydrocarbonaceous species that form over the catalyst are undertaken using a combination of temperature-programmed oxidation, powder X-ray diffraction, Raman scattering, transmission electron microscopy and inelastic neutron scattering (INS). Catalyst samples were exposed to ambient pressure CO hydrogenation at 623 K for defined periods of time-on-stream (3, 6, 12 and 24 h) prior to analysis. INS reveals a progressive retention of hydrogenous species that is associated with the evolution of a hydrocarbonaceous overlayer, as evidenced by the presence of sp2 and sp3 hybridized C-H vibrational modes. Correlations between the formation of aliphatic and olefinic/aromatic moieties with post-reaction characterization leads to the proposal of a number of chemical transformations that, collectively, define the conditioning phase of the catalyst under the specified set of reaction conditions. A comparison between the inelastic neutron scattering spectra of the 24 h sample with that of an iron catalyst extracted from a commercial grade Fischer-Tropsch reactor validates the relevance of the experimental approach adopted.

8.
J Chem Phys ; 143(17): 174703, 2015 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-26547178

RESUMO

An iron based Fischer-Tropsch synthesis catalyst is evaluated using CO hydrogenation at ambient pressure as a test reaction and is characterised by a combination of inelastic neutron scattering (INS), powder X-ray diffraction, temperature-programmed oxidation, Raman scattering, and transmission electron microscopy. The INS spectrum of the as-prepared bulk iron oxide pre-catalyst (hematite, α-Fe2O3) is distinguished by a relatively intense band at 810 cm(-1), which has previously been tentatively assigned as a magnon (spinon) feature. An analysis of the neutron scattering intensity of this band as a function of momentum transfer unambiguously confirms this assignment. Post-reaction, the spinon feature disappears and the INS spectrum is characterised by the presence of a hydrocarbonaceous overlayer. A role for the application of INS in magnetic characterisation of iron based FTS catalysts is briefly considered.


Assuntos
Monóxido de Carbono/química , Compostos Férricos/química , Magnetismo , Nêutrons , Catálise , Hidrogenação , Microscopia Eletrônica de Transmissão , Análise Espectral Raman
9.
Phys Chem Chem Phys ; 14(43): 15214-25, 2012 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-22914770

RESUMO

The methane reforming reaction with carbon dioxide as the oxidant over alumina-supported nickel and gold-doped nickel catalysts is studied using a variety of techniques such as reaction testing, vibrational spectroscopy (inelastic neutron scattering (INS), Raman scattering and infrared absorption), temperature-programmed oxidation (TPO), transmission electron microscopy and X-ray powder diffraction. The quantities of retained carbon and hydrogen are determined by TPO and INS, respectively. Minimal hydrogen retention indicates these catalysts to be very efficient at cycling hydrogen. The relative partitioning of hydrogen within the reaction media is used to formulate a qualitative description of the reaction kinetics. The presence of the gold modifier does not appear to provide any improvement in catalyst performance under the specified reaction conditions.

10.
Phys Chem Chem Phys ; 12(13): 3102-7, 2010 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-20237696

RESUMO

An alumina-supported nickel catalyst has been used to effect the 'dry' reforming of methane, using CO(2) as the oxidant. After 6 hours on-stream, reaction was stopped and the sample analysed by inelastic neutron scattering (INS). The INS spectrum reveals the presence of hydrocarbonaceous species as well as hydroxyl species present at the catalyst surface. Through the use of appropriate reference compounds, calibration procedures have been developed to determine the concentration of the retained hydrocarbon and hydroxyl moieties. Ancillary temperature programmed oxidation experiments establish the total carbon content. This approach not only enables the extent of overall carbon laydown to be determined but it also identifies the degree to which hydrogen is associated with carbon and oxygen atoms. The methodology described is generic and should be applicable to a wide number of heterogeneously catalysed systems.

11.
Cell Metab ; 4(3): 211-21, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16950138

RESUMO

Accumulation of macrophage foam cells in atherosclerotic blood vessel intima is a critical component of atherogenesis mediated by scavenger receptor-dependent internalization of oxidized LDL. We demonstrated by coimmunoprecipitation and pull-down assays that the macrophage scavenger receptor CD36 associates with a signaling complex containing Lyn and MEKK2. The MAP kinases JNK1 and JNK2 were specifically phosphorylated in macrophages exposed to oxLDL. Using cells isolated from SRA, TLR2, or CD36 null mice, and phospholipid ligands specific for either SRA or CD36, we showed that JNK activation was mediated by CD36. Both foam cell formation and activation of JNK2 in hyperlipidemic mice were diminished in the absence of CD36. Furthermore, inhibition of Src or JNK blocked oxLDL uptake and inhibited foam cell formation in vitro and in vivo. These findings show that a specific CD36-dependent signaling pathway initiated by oxLDL is necessary for foam cell formation and identify potential targets for antiatherosclerosis therapy.


Assuntos
Aterosclerose/metabolismo , Antígenos CD36/metabolismo , Células Espumosas/metabolismo , Hiperlipidemias/metabolismo , Macrófagos/metabolismo , Transdução de Sinais/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Aterosclerose/tratamento farmacológico , Aterosclerose/fisiopatologia , Células Endoteliais/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Hiperlipidemias/fisiopatologia , Hipolipemiantes/farmacologia , Lipoproteínas LDL/metabolismo , MAP Quinase Quinase Quinase 2/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteína Quinase 9 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 9 Ativada por Mitógeno/metabolismo , Oxirredução , Fosforilação , Receptor 2 Toll-Like/metabolismo , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA