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1.
Ann Clin Psychiatry ; 34(2): 114-122, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35471156

RESUMO

BACKGROUND: Identifying individuals at increased risk of suicide is important, particularly those who present for treatment for nonpsychiatric chief complaints who may go undetected. It has been found that pain symptoms, such as headache, are associated with suicide, although this association requires further characterization. This study examined specific components of suicidality in relation to headache subtypes. METHODS: This study retrospectively reviewed 2,832,835 nonpsychiatric adult clinical encounters at a large county hospital, where a standardized suicide risk screening tool, the Columbia-Suicide Severity Rating Scale (C-SSRS), was universally implemented. The C-SSRS assesses specific components of suicidality: wish to be dead and suicidal ideation, method, intent, plan, and action. Multivariate logistic regressions were performed to assess the association between headache, as well as headache subtype (migraine, tension, or cluster), and each component of suicidality. RESULTS: There were significant positive associations between presenting with a headache and 2 specific components of suicidality: wish to be dead and suicidal action. Individuals with tension headache may have a lower risk of wishing to be dead compared to those with migraine and cluster headaches. CONCLUSIONS: The association of headaches with specific elements of sui-cidality demonstrates the potential yield of identification of suicide risk among individuals with nonpsychiatric presentations.


Assuntos
Transtornos de Enxaqueca , Suicídio , Adulto , Cefaleia , Hospitais de Condado , Humanos , Estudos Retrospectivos , Ideação Suicida
2.
Eur Arch Otorhinolaryngol ; 279(6): 2857-2863, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34291348

RESUMO

PURPOSE: In chronic otitis media (COM), disease chronicity and severity of middle ear inflammation may influence the development of inner ear deficits, increasing the risk of vestibular impairment. This secondary analysis of the multinational collaborative Chronic Otitis Media Questionnaire-12 (COMQ-12) dataset sought to determine the prevalence of vestibular symptoms in patients with COM and identify associated disease-related characteristics. METHODS: Adult patients with a diagnosis of COM in outpatient settings at nine otology referral centers across eight countries were included. We investigated the presence of vestibular symptoms (dizziness and/or disequilibrium) using participant responses to item 6 of a native version of the COMQ-12. Audiometric data and otoscopic assessment were also recorded. RESULTS: This analysis included 477 participants suffering from COM, with 56.2% (n = 268) reporting at least mild inconvenience related to dizziness or disequilibrium. There was a significant association between air conduction thresholds in the worse hearing ear and presence of dizziness [adjusted odds ratio (AOR), 1.01; 95% CI 1.00-1.02; p = 0.0177]. Study participants in European countries (AOR 1.53; 95% CI 1.03-2.28; p = 0.0344) and Colombia (AOR 2.48; 95% CI 1.25-4.92; p = 0.0096) were more likely to report dizziness than participants in Asian countries. However, ear discharge and cholesteatoma showed no association with dizziness in the adjusted analyses. CONCLUSION: Vestibular symptoms contribute to burden of disease in patients with COM and associates with hearing disability in the worse hearing ear. Geographical variation in presentation of dizziness may reflect financial barriers to treatment or cultural differences in how patients reflect on their health state.


Assuntos
Tontura , Otite Média , Adulto , Doença Crônica , Tontura/complicações , Tontura/etiologia , Humanos , Otite Média/complicações , Otite Média/diagnóstico , Otite Média/epidemiologia , Qualidade de Vida , Inquéritos e Questionários , Vertigem/complicações
3.
Surgeon ; 16(1): 12-19, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26993760

RESUMO

INTRODUCTION: Work-related stress, psychological disorders and burnout are common occupational disorders affecting UK doctors. To date, there are no studies looking at these psychosocial morbidities amongst ENT surgeons worldwide. METHODS: The General Health Questionnaire-12 (GHQ-12) and abbreviated Maslach Burnout Inventory (aMBI) were incorporated into a questionnaire on occupational diseases amongst ENT surgeons and distributed to the entire membership of ENT-UK. The survey study also acquired demographic data on grade of respondent, years of experience in ENT and subspecialty interest. RESULTS: We received 108 (8.1% response rate) appropriately filled GHQ-12 and 121 (9.0% response rate) aMBI questionnaires. 61 respondents (56.5%) on the GHQ-12 were at high risk of developing stress and psychological morbidity and 35 (28.9%) had high enough aMBI scores to suggested burnout. When comparing scores of both GHQ-12 and aMBI with grade of respondent, years of experience in ENT and subspecialty, statistical difference was only found on the risk of stress and psychiatric disorders amongst paediatric ENT surgeons (7 high risk vs 0 low risk, p = 0.02), however the number of these respondents was small (7 in total). Both questionnaires had been validated for use within our population. CONCLUSION: We found high incidence rates of stress and psychological morbidity (56.5%) and a burnout prevalence rate of 28.9% amongst our responding cohort of UK Oto-rhino-laryngologists. No meaningful differences were found between stress, psychological morbidity and burnout with grade of ENT surgeon, years of experience in ENT and subspecialty within ENT.


Assuntos
Esgotamento Profissional/psicologia , Transtornos Mentais/psicologia , Estresse Ocupacional/psicologia , Otolaringologia/estatística & dados numéricos , Estresse Psicológico/psicologia , Cirurgiões/psicologia , Inquéritos Epidemiológicos , Humanos , Medição de Risco , Cirurgiões/estatística & dados numéricos , Reino Unido/epidemiologia
4.
Angew Chem Int Ed Engl ; 56(44): 13876-13881, 2017 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-28787552

RESUMO

The conversion of methane into alcohols under moderate reaction conditions is a promising technology for converting stranded methane reserves into liquids that can be transported in pipelines and upgraded to value-added chemicals. We demonstrate that a catalyst consisting of small nickel oxide clusters supported on ceria-zirconia (NiO/CZ) can convert methane to methanol and ethanol in a single, steady-state process at 723 K using O2 as an abundantly available oxidant. The presence of steam is required to obtain alcohols rather than CO2 as the product of catalytic combustion. The unusual activity of this catalyst is attributed to the synergy between the small Lewis acidic NiO clusters and the redox-active CZ support, which also stabilizes the small NiO clusters.

5.
Eur Arch Otorhinolaryngol ; 273(9): 2825-32, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27048520

RESUMO

Occupational-related hazards (OH) are noted to be prevalent within the medical community. However, there is limited evidence of its effects amongst ENT surgeons. A national survey was carried out with the assistance of ENT-UK to investigate the prevalence of various OH amongst ENT doctors in the UK. A literature search was also conducted to search for articles within English literature worldwide on this subject. 70.6 % of the responding 323 ENT surgeons had reported a form of OH throughout their career. Musculoskeletal pain was the most commonly reported (47.4 %) followed by stress/psychiatric morbidities (38.4 %) and sharps injuries (26.6 %). We found no correlation between OH and consultants/non-consultant status, time spent in ENT and subspecialty. Our literature search revealed 16 articles pertaining to OH amongst ENT doctors. OHs are prevalent within the UK ENT community. There is good evidence within literature on musculoskeletal pain, however, higher level studies are required to thoroughly investigate the other hazards.


Assuntos
Doenças Profissionais/epidemiologia , Exposição Ocupacional/efeitos adversos , Otorrinolaringologistas/estatística & dados numéricos , Otolaringologia , Humanos , Morbidade/tendências , Prevalência , Reino Unido/epidemiologia
6.
Int J Mol Sci ; 16(7): 14640-54, 2015 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-26132568

RESUMO

Individuals in the early phases of psychotic illness have disturbed metacognitive capacity, which has been linked to a number of poor outcomes. Little is known, however, about the neural systems associated with metacognition in this population. The purpose of this study was to elucidate the neuroanatomical correlates of metacognition. We anticipated that higher levels of metacognition may be dependent upon gray matter density (GMD) of regions within the prefrontal cortex. Examining whole-brain structure in 25 individuals with early phase psychosis, we found positive correlations between increased medial prefrontal cortex and ventral striatum GMD and higher metacognition. These findings represent an important step in understanding the path through which the biological correlates of psychotic illness may culminate into poor metacognition and, ultimately, disrupted functioning. Such a path will serve to validate and promote metacognition as a viable treatment target in early phase psychosis.


Assuntos
Metacognição , Transtornos Psicóticos/fisiopatologia , Esquizofrenia/fisiopatologia , Adolescente , Adulto , Corpo Estriado/fisiopatologia , Feminino , Substância Cinzenta/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Córtex Pré-Frontal/fisiopatologia , Transtornos Psicóticos/diagnóstico , Esquizofrenia/diagnóstico
7.
Langenbecks Arch Surg ; 399(8): 967-79, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25113227

RESUMO

INTRODUCTION: Health-care workers are subjected to various occupational hazards within the National Health Service (NHS). Surgeons are not excluded from this group due to the nature of work carried out on a daily basis. As a result, we set out to investigate the common work-related health issues a surgeon practising in the UK may encounter. METHOD: A literature search conducted on PubMed, EMBASE, MEDLINE® and Health Management Information Consortium (HMIC) revealed 66 literature papers between the years 1990 and 2013. Thirty-seven were excluded from our review process for various reasons. RESULTS: Surgeons in the UK are likely to be susceptible to stress, sharp injuries, burnout and psychiatric morbidities, substance abuse and musculoskeletal pain. Noise-induced hearing loss has been reported amongst orthopaedic surgeons due to the use of electric and air-powered drills and saws. No reports of skin-related illness, respiratory illness, nosocomial infections or malignancies were found within the published UK literature of our targeted group although they have been noted in other specialties. CONCLUSION: These occupational hazards pose a huge risk to the NHS and the personal well-being of its surgeons. As such, the importance of early awareness and education alongside prompt intervention is duly emphasized.


Assuntos
Acidentes de Trabalho/estatística & dados numéricos , Doenças Profissionais/epidemiologia , Cirurgiões , Humanos , Fatores de Risco , Medicina Estatal , Reino Unido/epidemiologia
9.
Chem Commun (Camb) ; 60(55): 7077-7080, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38895782

RESUMO

This study investigates the effects of elevated temperature thermal treatments on the direct air capture of CO2 by aminosilane-grafted SBA-15 silica sorbents. Exposing samples to high temperatures (200-250 °C compared to 80-120 °C) in an inert environment resulted in improved CO2 capacity (5-21%) that was sustained over multiple adsorption/desorption cycles.

10.
Otol Neurotol ; 43(8): 931-936, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35833869

RESUMO

OBJECTIVE: This study aimed to determine the responsiveness of three instruments (disease-specific, generic, and hearing-specific) assessing health-related quality of life (HRQoL) in adult patients undergoing surgery for chronic otitis media (COM). STUDY DESIGN: Prospective correlational study. SETTING: Two otology referral centers in England, United Kingdom. PATIENTS: Consecutive adult patients undergoing middle ear surgery for COM. MAIN OUTCOME MEASURES: HRQoL assessment and audiometry were performed preoperatively and 12 months after surgery. HRQoL was assessed using disease-specific (Chronic Otitis Media Questionnaire-12 [COMQ-12]), generic (Euro-Qol-5D-5L), and hearing-specific (Hearing Handicap Inventory for Adults [HHIA]) instruments. RESULTS: A total of 52 patients (mean [standard deviation {SD}] age, 47.3 [18.3] yr) were included, with 42 patients completing both preoperative and postoperative COMQ-12 forms. COMQ-12 and HHIA total scores significantly improved after surgery (COMQ-12: mean [SD], 28.3 [11.6] versus 14.8 [10.6]; p < 0.001; HHIA: 42.9 (28.4) versus 32.6 (27.5); p = 0.012). General HRQoL measured with the Euro-Qol-5D-5L was unaffected by surgery ( p > 0.05). The standardized response means for the COMQ-12 and HHIA total scores were 1.21 and 0.44, respectively. Postoperative air conduction thresholds were moderately correlated with the postoperative COMQ-12 ( r = 0.46, p = 0.005) and HHIA ( r = 0.41, p = 0.012) total scores. CONCLUSIONS: Middle ear surgery significantly improved both disease-specific and hearing-specific HRQoL, whereas general HRQoL did not change. Only the COMQ-12 is highly responsive to surgical intervention. This study supports the use of the COMQ-12 to monitor patient-reported outcomes in both research and routine clinical settings.


Assuntos
Otite Média , Qualidade de Vida , Adulto , Doença Crônica , Orelha Média/cirurgia , Audição , Humanos , Pessoa de Meia-Idade , Otite Média/cirurgia , Estudos Prospectivos , Reprodutibilidade dos Testes , Inquéritos e Questionários
11.
Ann Otol Rhinol Laryngol ; 120(8): 535-41, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21922978

RESUMO

OBJECTIVES: The study compares the medium-term outcomes of myringoplasty procedures using fascia and cartilage grafts. METHODS: Patients with chronic otitis media with perforations larger than 50% of the size of the tympanic membrane were included in a randomized, controlled, prospective clinical trial. The perforations were repaired with either temporalis fascia (20 ears) or cartilage (18 ears) grafts selected randomly. A search of the literature was performed to look for other randomized studies comparing fascia and cartilage. RESULTS: The graft take rates of fascia and cartilage grafts at 24 months were 84.2% and 80%, respectively. The postoperative air-bone gaps and hearing gains at 24 months were 16.97 dB and 13.63 dB, respectively, in the fascia group and 20.63 dB and 12.60 dB, respectively, in the cartilage group. There was no significant difference in the graft take rates or postoperative hearing between the two groups. The literature search identified one other randomized study comparing fascia and cartilage grafts in the repair of large perforations. The pooled data from the two studies did not show a difference in the graft take rates or hearing gains between cartilage and fascia. CONCLUSIONS: There was no statistical difference in the outcomes of fascia and cartilage grafts in the repair of large perforations.


Assuntos
Cartilagem/transplante , Fáscia/transplante , Miringoplastia/métodos , Perfuração da Membrana Timpânica/cirurgia , Adolescente , Adulto , Idoso , Criança , Estudos de Coortes , Feminino , Audição , Humanos , Masculino , Pessoa de Meia-Idade , Otite Média/complicações , Recuperação de Função Fisiológica , Resultado do Tratamento , Perfuração da Membrana Timpânica/etiologia , Adulto Jovem
12.
Otol Neurotol ; 42(7): e881-e886, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33710158

RESUMO

OBJECTIVE: To present the results of a 15-year longitudinal study in a pediatric and adult population with secondary obliteration of troublesome mastoid cavities. STUDY DESIGN: Prospective longitudinal study. PATIENTS: Children (≤16 yrs) and adults who had obliteration surgery (228 ears) between 2000 and 2017. INTERVENTIONS: Therapeutic. SETTING: Tertiary referral center. MAIN OUTCOME MEASURES: 1) Incidence of recurrent or residual cholesteatoma; 2) creation of a dry ear at 5 years postsurgery; 3) postoperative complications; 4) waterproof status of ear; 5) number of subsequent ear surgery required. RESULTS: Thirty-one pediatric and 197 adult cases contributed to the study. At 5 years 11 of 98 (10.8%) had been lost to follow-up. Using Kaplan-Meier survival analysis, the residual rate after 5 years was 4.2% (95% CI: 0.3%-8.2%) and the recurrence rate was 1% (95% CI: 0.0%-3.0%). Of the 223 ears available for assessment, 209 (93.7%) achieved a dry state, 6 (2.7%) had intermittent discharge, 6 (2.7%) had flap necrosis requiring flap trimming, and 1 (0.4%) developed meatal stenosis. Using a cross-sectional analysis at 12 months of follow-up, the otorrhea risk was 19.2% and the risk of definitive waterproofing was 10.9%. There was a reoperation risk of 10% within 5 years which included second-stage ossiculoplasty. CONCLUSIONS: Secondary mastoid obliteration is a safe and useful technique in treating the troublesome mastoid cavity in both children and adults. It is associated with a low cholesteatoma recidivism rate and high rate of a trouble-free ear in the long term.


Assuntos
Colesteatoma da Orelha Média , Processo Mastoide , Adulto , Criança , Colesteatoma da Orelha Média/cirurgia , Estudos Transversais , Humanos , Estudos Longitudinais , Processo Mastoide/cirurgia , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
13.
Otol Neurotol ; 42(1): e50-e59, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32890292

RESUMO

INTRODUCTION: Tympanic membrane retraction (TMR) is a relatively common otologic finding. Currently, there is no consensus on the optimal treatment of TMR. Some ENT-surgeons advocate surgical correction while others opt for a watchful-waiting policy. Our aim was to investigate the natural course of retraction pockets in the posterosuperior quadrant of the pars tensa in a large cohort of patients. METHODS: An observational retrospective cohort study was conducted including patients of all ages with a posterosuperior pars tensa retraction. Primary outcome measure was difference between audiometry at first and last visits. Secondary outcomes were patients' complaints, otoscopic outcomes (Sade classification), and complications (perforation, ossicular chain damage, and/or cholesteatoma). RESULTS: A total of 71 patients with 81 ears and a median age of 23 years (IQR 14-47) were included. The median duration of follow-up was 64 months (IQR 44-102). The mean air-bone gap at first and last visits was 17.9 dB (SD 11.3) and 15.5 dB (SD 12.9), respectively, with a mean improvement of 2.4 dB (p = 0.08). In 10 ears (12%) the hearing level (air-bone gap) deteriorated with 10 dB or more. Patients who presented with a TMR Sade grade I at first visit had significantly better audiometric outcomes than patients presenting with Sade grade III (p = 0.001). Progression to cholesteatoma occurred in one patient (1%), progression to perforation occurred in five patients (6%), and progression to ossicular chain damage occurred in five patients (6%). CONCLUSIONS: Otoscopic findings and audiometric results remained stable in most TMRs without treatment. Additionally, audiometry did not worsen during last follow-up. Progression to cholesteatoma, perforation, or ossicular chain damage was rare. Shared decision making regarding TMRs should include a discussion of a wait-and-see policy.


Assuntos
Colesteatoma da Orelha Média , Membrana Timpânica , Adolescente , Adulto , Audiometria de Tons Puros , Humanos , Pessoa de Meia-Idade , Políticas , Estudos Retrospectivos , Membrana Timpânica/cirurgia , Conduta Expectante , Adulto Jovem
14.
Otol Neurotol ; 42(1): e45-e49, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33201077

RESUMO

OBJECTIVES: The Chronic Otitis Media Questionnaire-12 (COMQ-12) assesses patient-reported health-related quality of life. A multinational collaborative project was performed to translate and appraise the psychometric properties of the COMQ-12 across Europe, Asia, and South America. METHODS: Eight otology units from seven countries (China, Colombia, France, Italy, Japan, Korea, Turkey) created native versions of the COMQ-12 by the process of translation and back-translation. Questionnaire reliability was assessed on the basis of internal consistency by calculating Cronbach's coefficient alpha. Exploratory factor analysis was performed to identify underlying correlations between individual questionnaire items. RESULTS: This study included 478 participants from 8 countries. Calculated values for Cronbach's coefficient alpha were between 0.71 and 0.90. Exploratory factor analysis allowed the identification of three dominant factors, the primary factor (related to hearing problems) explaining 42% of the total variance, the secondary factor (related to daily activities) explaining 30% of the variance, and the third factor (related to acute disease activity) explaining 28% of the variance. CONCLUSIONS: This is a large study of patients with chronic otitis media, from centers from within many different countries spanning Europe, Asia, and South America. This study supports the use of the COMQ-12 within the individual countries where it was tested.


Assuntos
Otite Média , Qualidade de Vida , China , Europa (Continente) , Humanos , Itália , Japão , Psicometria , Reprodutibilidade dos Testes , República da Coreia , América do Sul , Inquéritos e Questionários
15.
Otol Neurotol ; 42(10): e1507-e1512, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34325452

RESUMO

OBJECTIVE: This study aimed to assess how two disease-related factors, hearing disability and ear discharge, affect health-related quality-of-life (HRQoL) in patients with chronic otitis media (COM). STUDY DESIGN: Multinational prospective cohort study. SETTING: Nine otology referral centers in eight countries. PATIENTS: Adult patients suffering from COM. MAIN OUTCOME MEASURES: Hearing disability and ear discharge were assessed by audiometry (Department of Health and Social Security formula) and otoscopy, respectively. Participants completed a native version of the Chronic Otitis Media Questionnaire-12 (COMQ-12). We determined how the two disease-related factors affect HRQoL by performing two separate analyses: (1) using a 6-item score combining responses to COMQ-12 items independent of hearing loss and ear discharge and (2) using item 12 alone as a proxy for global HRQoL. RESULTS: This study included 478 participants suffering from COM. There was a significant association between HRQoL and hearing disability in the adjusted analysis. For every unit increase in the Department of Health and Social Security average hearing threshold (1) there was an increase of 0.06 (95% CI [0.007, 0.121], p = 0.0282) in the 6-item score and (2) the adjusted odds of having a higher item 12 score was 1.03 (95% CI [1.01, 1.04], p = 0.0004). There was no association between the presence of ear discharge and HRQoL in both COMQ-12 score analyses. CONCLUSIONS: Knowledge of disease-related factors that influence HRQoL will aid interpretation of patient-reported measures for COM. Patients with a greater degree of hearing impairment appear to have poorer HRQoL, which is not exacerbated by the presence of ear discharge. The magnitude of postoperative hearing improvement rather than the attainment of a dry ear may be a better indicator of surgical success from the patient's perspective.


Assuntos
Otite Média , Qualidade de Vida , Adulto , Doença Crônica , Audição , Humanos , Otite Média/complicações , Otite Média/cirurgia , Alta do Paciente , Estudos Prospectivos , Inquéritos e Questionários
16.
Laryngoscope ; 131(3): E732-E737, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33270236

RESUMO

OBJECTIVES/HYPOTHESIS: Otolaryngology instructional videos available online are often of poor quality. The objective of this article was to establish international consensus recommendations for the production of educational surgical videos in otolaryngology. STUDY DESIGN: DELPHI survey. METHODS: Twenty-seven international respondents participated in this study from 12 countries. Consensus was reached after three rounds of questionnaires following the Delphi methodology. The proposals having reached the 80% agreement threshold in the third round were retained. RESULTS: The main recommendations are as follows: 1) Ethics: patients must be anonymized and unrecognizable (apart from plastic surgery if necessary). A signed authorization must be obtained if the person is recognizable. 2) Technical aspects: videos should be edited and in high-definition (HD) quality if possible. Narration or subtitles and didactic illustrations are recommended. 3) Case presentation: name of pathology and procedure must be specified; the case should be presented with relevant workup. 4) Surgery: surgical procedures should be divided into several distinct stages and include tips and pitfalls. Pathology should be shown if relevant. Key points should be detailed at the end of the procedure. 5) Organ-specific: type of approach and bilateral audiometry should be specified in otology. Coronal plane computed tomography scans should be shown in endonasal surgery. It is recommended to show pre- and postoperative videos in voice surgery and preoperative drawings and photos of scars in plastic surgery, as well as the ventilation method in airway surgery. CONCLUSIONS: International recommendations have been determined to assist in the creation and standardization of educational surgical videos in otolaryngology and head and neck surgery. LEVEL OF EVIDENCE: 5 Laryngoscope, 131:E732-E737, 2021.


Assuntos
Otolaringologia/normas , Procedimentos Cirúrgicos Otorrinolaringológicos/educação , Gravação de Videoteipe/normas , Consenso , Técnica Delphi , Humanos , Otolaringologia/educação , Inquéritos e Questionários
17.
Langmuir ; 26(21): 16589-94, 2010 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-20586431

RESUMO

Deactivation mechanisms of alumina-supported, Ni-based catalysts for tar reforming in biomass-derived syngas were evaluated using extended X-ray absorption fine structure (EXAFS) spectroscopy. Catalysts were characterized before and after catalytic reaction cycles and regeneration procedures, which included oxidation by a mixture of steam and air, and reduction in hydrogen. Qualitative analysis of the EXAFS spectra revealed that oxidation of a portion of the Ni in the catalysts to form an oxide phase and/or a sulfide phase were likely scenarios that led to catalyst deactivation with time-on-stream and with increased reaction cycles. Deactivation through carbon deposition, phosphorus poisoning, or changes in particle size were deemed as unlikely causes. Quantitative analysis of the EXAFS spectra indicated sulfur poisoning occurred with time-on-stream, and the contaminating species could not be completely removed during the regeneration protocols. The results also verified that Ni-containing oxide phases (most likely a spinel also containing Mg and Al) formed and contributed to the deactivation. This study validates the need for developing catalyst systems that will protect Ni from sulfur poisoning and oxide formation at elevated reaction and regeneration temperatures.


Assuntos
Óxido de Alumínio/química , Níquel/química , Catálise , Cinética , Tamanho da Partícula , Propriedades de Superfície , Espectroscopia por Absorção de Raios X
18.
Schizophr Res ; 218: 107-115, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32037204

RESUMO

Schizophrenia is a disorder of altered neural connections resulting in impaired information integration. Whole brain assessment of within- and between-network connections may determine how information processing is disrupted in schizophrenia. Patients with early-stage schizophrenia (n = 56) and a matched control sample (n = 32) underwent resting-state fMRI scans. Gray matter regions were organized into nine distinct functional networks. Functional connectivity was calculated between 278 gray matter regions for each subject. Network connectivity properties were defined by the mean and variance of correlations of all regions. Whole-brain network measures of global efficiency (reflecting overall interconnectedness) and locations of hubs (key regions for communication) were also determined. The control sample had greater connectivity between the following network pairs: somatomotor-limbic, somatomotor-default mode, dorsal attention-default mode, ventral attention-limbic, and ventral attention-default mode. The patient sample had greater variance in interactions between ventral attention network and other functional networks. Illness duration was associated with overall increases in the variability of network connections. The control group had higher global efficiency and more hubs in the cerebellum network, while patient group hubs were more common in visual, frontoparietal, or subcortical networks. Thus, reduced functional connectivity in patients was largely present between distinct networks, rather than within-networks. The implications of these findings for the pathophysiology of schizophrenia are discussed.


Assuntos
Mapeamento Encefálico , Esquizofrenia , Encéfalo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Vias Neurais/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagem
19.
Appl Ergon ; 83: 102679, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29735161

RESUMO

Neck and shoulder disorders are a considerable health problem amongst frequent microscope users. We aimed to investigate the neck and shoulder discomfort experienced during prolonged microscopic activity and to assess the benefits of minibreaks. A prospective crossover study was performed on 17 healthy volunteers sitting still while looking down a bench with and without the Ipswich Microbreak Technique (IMT). We used a subjective measure of time to fatigue and pain in the neck and shoulder regions as well as objective readings from a surface electromyogram (sEMG). The IMT delayed the sensation of pain in the neck and shoulder region while reducing the overall sEMG muscle activation. In conclusion, IMT is a useful strategy in reducing and delaying the pain in neck and shoulder from prolonged working under the microscope. This technique can be incorporated in other activities that involve a sustained stationary position.


Assuntos
Dor Musculoesquelética/prevenção & controle , Cervicalgia/prevenção & controle , Doenças Profissionais/prevenção & controle , Postura/fisiologia , Dor de Ombro/prevenção & controle , Adulto , Estudos Cross-Over , Eletromiografia/métodos , Feminino , Humanos , Decoração de Interiores e Mobiliário/normas , Masculino , Estudos Prospectivos
20.
Otolaryngol Head Neck Surg ; 140(1): 23-8, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19130956

RESUMO

OBJECTIVE: To investigate bipolar diathermy power settings as a risk factor for postoperative hemorrhage following tonsillectomy. STUDY DESIGN AND SETTING: A prospective cohort study was undertaken between July 2003 and September 2004 in National Health Service (NHS) and independent hospitals in England and Northern Ireland. Data were collected on patient characteristics, tonsillectomy technique, and postoperative hemorrhage within 28 days of surgery. RESULTS: Among the 9572 patients who had a tonsillectomy performed with bipolar diathermy dissection and hemostasis, the overall rate of hemorrhage was 4.6 percent and the risk of hemorrhage was not associated with the diathermy power setting. Among the 8465 patients who had tonsillectomy with cold steel dissection and bipolar diathermy hemostasis, the rate of hemorrhage increased from 1.8% in patients with the lowest power settings (6 to 8 watts) to 3.7% in those with settings above 18 watts (P value for trend = 0.005). CONCLUSION: In tonsillectomies using cold steel dissection and bipolar diathermy for hemostasis, the risk of postoperative hemorrhage becomes greater as diathermy power increases.


Assuntos
Diatermia/métodos , Hemorragia/etiologia , Tonsilectomia/métodos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Complicações Pós-Operatórias , Estudos Prospectivos , Fatores de Risco , Tonsilectomia/efeitos adversos
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