Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Chem Sci ; 15(25): 9599-9611, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38939136

RESUMEN

The scission and homologation of CO is a fundamental process in the Fischer-Tropsch reaction. However, given the heterogeneous nature of the catalyst and forcing reaction conditions, it is difficult to determine the intermediates of this reaction. Here we report detailed mechanistic insight into the scission/homologation of CO by two-coordinate iron terphenyl complexes. Mechanistic investigations, conducted using in situ monitoring and reaction sampling techniques (IR, NMR, EPR and Mössbauer spectroscopy) and structural characterisation of isolable species, identify a number of proposed intermediates. Crystallographic and IR spectroscopic data reveal a series of migratory insertion reactions from 1Mes to 4Mes. Further studies past the formation of 4Mes suggest that ketene complexes are formed en route to squaraine 2Mes and iron carboxylate 3Mes, with a number of ketene containing structures being isolated, in addition to the formation of unbound, protonated ketene (8). The synthetic and mechanistic studies are supported by DFT calculations.

2.
Spine Deform ; 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38592647

RESUMEN

PURPOSE: The spine, hip, and knee are anatomically and biomechanically connected. Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are commonly employed to treat degenerative changes in the hip and knee, while fusion is used for spine degeneration. Spine deformity correction results in changes in sagittal alignment and pelvic parameters, and patients with stiff spines have higher rates of THA dislocation and revision due to instability. The goal of this study was to determine the prevalence of total joint arthroplasty (TJA) in adult spinal deformity (ASD) patients at our institution. METHODS: Following Institutional Review Board approval, we retrospectively reviewed a list of cases performed by the senior author from 4/2017 to 5/2021. Patients > 18 years old undergoing preoperative evaluation for symptomatic lumbar degeneration or ASD were included. Patients < 18 years old, those diagnosed with adolescent idiopathic scoliosis, and non-fusion cases were excluded. Perioperative full-length standing EOS images were examined for the presence or absence of THA, TKA, or both. Demographic data was collected from patient electronic medical records, and statistical analyses were completed. RESULTS: 572 consecutive cases were reviewed, and 322 were excluded. 250 cases (97M:153F) were included in the final analysis, with a mean age of 61.8 ± 11.2 years. A total of 74 patients had a TJA (29.4%). THA was present in 41 patients (16.4%), and TKA was present in 49 patients (19.6%). Males had a higher prevalence of TJA, THA, and TKA (29.9%, 16.5%, and 21.6%) than females (29.4%, 16.3%, and 18.3%). CONCLUSIONS: This study revealed a high prevalence TJA rate of 29.4% in ASD at our institution. This rate surpasses the prevalence rate reported among the general population in previous studies. High prevalence of patients with ASD and TJA may merit special surgical consideration.

4.
Resusc Plus ; 14: 100406, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37424769

RESUMEN

Objectives: The International Liaison Committee on Resuscitation, in collaboration with drowning researchers from around the world, aimed to review the evidence addressing seven key resuscitation interventions: 1) immediate versus delayed resuscitation; (2) compression first versus ventilation first strategy; (3) compression-only CPR versus standard CPR (compressions and ventilations); (4) ventilation with and without equipment; (5) oxygen administration prior to hospital arrival; (6) automated external defibrillation first versus cardiopulmonary resuscitation first strategy; (7) public access defibrillation programmes. Methods: The review included studies relating to adults and children who had sustained a cardiac arrest following drowning with control groups and reported patient outcomes. Searches were run from database inception through to April 2023. The following databases were searched Ovid MEDLINE, Pre-Medline, Embase, Cochrane Central Register of Controlled Trials. Risk of bias was assessed using the ROBINS-I tool and the certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation. The findings are reported as a narrative synthesis. Results: Three studies were included for two of the seven interventions (2,451 patients). No randomised controlled trials were identified. A retrospective observational study reported in-water resuscitation with rescue breaths improved patient outcomes compared to delayed resuscitation on land (n = 46 patients, very low certainty of evidence). The two observational studies (n = 2,405 patients), comparing compression-only with standard resuscitation, reported no difference for most outcomes. A statistically higher rate of survival to hospital discharge was reported for the standard resuscitation group in one of these studies (29.7% versus 18.1%, adjusted odds ratio 1.54 (95% confidence interval 1.01-2.36) (very low certainty of evidence). Conclusion: The key finding of this systematic review is the paucity of evidence, with control groups, to inform treatment guidelines for resuscitation in drowning.

5.
J Bone Joint Surg Am ; 105(18): 1395-1402, 2023 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-37486981
6.
J Arthroplasty ; 38(11): 2455-2463, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37236289

RESUMEN

BACKGROUND: In 2005, the Food and Drug Administration placed a black-box warning (the most stringent warning for drugs) on all nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs) stating that these agents may cause heart attacks and/or strokes. No level I evidence demonstrates that nonselective NSAIDs increase cardiovascular risk. An alternative hypothesis is that hip and knee osteoarthritis (OA) indirectly causes cardiovascular disease (CVD) through decreased activity and NSAIDs are correlated with CVD as an arthritis treatment. METHODS: Systematic reviews were conducted to find observational studies evaluating the association of hip and/or knee OA, CVD, activity, walking, and step counts. The systematic review found studies correlating hip and/or knee OA and CVD morbidity incidence (n = 2); CVD morbidity prevalence (n = 6); odds ratios, relative risks, or hazard ratios of CVD morbidity (n = 11); relative risk, standardized mortality ratios, or hazard ratios of CVD mortality (n = 14); and all-cause mortality hazard ratios associated with NSAID use (n = 3). RESULTS: Hip OA (5 studies), knee OA (9 studies), and hip and knee OA (6 studies) are linked to an increased risk of CVD morbidity and mortality. Cardiac risk increases with validated disability scores, use of walking aids, walking difficulties, longer follow-up times, younger ages of OA onset, numbers of joints involved, and OA severities. No study linked NSAID use to cardiac disease. CONCLUSIONS: All studies with more than 10-year follow-up linked cardiac disease with hip and knee OA. No study linked nonselective NSAID use to CVD. The Food and Drug Administration should reconsider the black-box warnings on naproxen, ibuprofen, and celecoxib.


Asunto(s)
Antiinflamatorios no Esteroideos , Enfermedades Cardiovasculares , Osteoartritis de la Cadera , Osteoartritis de la Rodilla , Humanos , Antiinflamatorios no Esteroideos/efectos adversos , Enfermedades Cardiovasculares/inducido químicamente , Enfermedades Cardiovasculares/epidemiología , Progresión de la Enfermedad , Cardiopatías , Osteoartritis de la Cadera/tratamiento farmacológico , Osteoartritis de la Rodilla/tratamiento farmacológico , Estudios Observacionales como Asunto
7.
J Intensive Care Soc ; 24(1): 47-52, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36874289

RESUMEN

Aim: In the United Kingdom (UK), 600 deaths per annum are attributable to drowning. Despite this there is scarce critical care data on drowning patients globally. We describe drowning cases admitted to critical care units with a focus on functional outcomes. Materials and Methods: Medical records for critical care admissions following a drowning event were retrospectively reviewed across six hospitals in Southwest England for cases presenting in the period between 2009 and 2020. Data was collected according to the Utstein international consensus guidelines on drowning. Results: Forty-nine patients were included, 36 males and 13 females, including seven children. Median submersion duration was 2.5 min 20 cases were in cardiac arrest when rescued. At discharge 22 patients had preserved functional status, 10 patients had a reduced functional status. 17 patients died in hospital. Conclusion: Admission to critical care following drowning is uncommon and associated with high rates of mortality and poor functional outcomes. We find that 31% of those who survived a drowning event subsequently required an increased level of assistance with their activities of daily living.

8.
Int. arch. otorhinolaryngol. (Impr.) ; 26(3): 348-356, July-Sept. 2022. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1405147

RESUMEN

Abstract Introduction Traditionally, larger lesions of laryngeal verrucous carcinoma are treated with surgical excision, with definitive radiotherapy generally reserved for smaller lesions. However, data utilizing modern databases is limited. Objective The authors sought to assess, utilizing the National Cancer Database, whether overall survival for patients with laryngeal verrucous carcinoma was equivalent when treated with definitive radiotherapy versus definitive surgery. Methods A retrospective cohort study was conducted utilizing the National Cancer Database. All cases of laryngeal verrucous carcinoma within the National Cancer Database between 2006 and 2014 were reviewed. Patients with T1-T3 (American Joint Commission on Cancer 7th Edition) laryngeal verrucous carcinoma were included and stratified by treatment modality. Demographics, treatment, and survival data were analyzed. Results A total of 392 patients were included. Two hundred and fifty patients underwent surgery and 142 received radiotherapy. The two groups differed in age, transition of care, clinical T stage, and clinical stages. There was no significant difference in survival between T1-T3 lesions treated with surgery or radiotherapy (p =0.32). Age, comorbidities, insurance status, and clinical T stage impacted overall hazard on multivariate analysis (p <0.01). For patients treated with radiotherapy, age, insurance status, and clinical T stage were predictive of increased hazard. Conclusion Overall survival is equivalent for patients with clinical T1 and clinical T2 laryngeal verrucous carcinoma treated with primary radiotherapy versus primary surgery. Thus, radiotherapy should be considered as a non-inferior treatment modality for certain patients with laryngeal verrucous carcinoma.

9.
J Bone Joint Surg Am ; 104(18): 1599-1604, 2022 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-35980042
10.
Int Arch Otorhinolaryngol ; 26(3): e348-e356, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35846806

RESUMEN

Introduction Traditionally, larger lesions of laryngeal verrucous carcinoma are treated with surgical excision, with definitive radiotherapy generally reserved for smaller lesions. However, data utilizing modern databases is limited. Objective The authors sought to assess, utilizing the National Cancer Database, whether overall survival for patients with laryngeal verrucous carcinoma was equivalent when treated with definitive radiotherapy versus definitive surgery. Methods A retrospective cohort study was conducted utilizing the National Cancer Database. All cases of laryngeal verrucous carcinoma within the National Cancer Database between 2006 and 2014 were reviewed. Patients with T1-T3 (American Joint Commission on Cancer 7th Edition) laryngeal verrucous carcinoma were included and stratified by treatment modality. Demographics, treatment, and survival data were analyzed. Results A total of 392 patients were included. Two hundred and fifty patients underwent surgery and 142 received radiotherapy. The two groups differed in age, transition of care, clinical T stage, and clinical stages. There was no significant difference in survival between T1-T3 lesions treated with surgery or radiotherapy ( p = 0.32). Age, comorbidities, insurance status, and clinical T stage impacted overall hazard on multivariate analysis ( p < 0.01). For patients treated with radiotherapy, age, insurance status, and clinical T stage were predictive of increased hazard. Conclusion Overall survival is equivalent for patients with clinical T1 and clinical T2 laryngeal verrucous carcinoma treated with primary radiotherapy versus primary surgery. Thus, radiotherapy should be considered as a non-inferior treatment modality for certain patients with laryngeal verrucous carcinoma.

11.
Organometallics ; 41(7): 883-891, 2022 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-35571260

RESUMEN

Quantitative catalytic nucleophilic fluorination of a range of acyl chlorides to acyl fluorides was promoted by a cyclometallated rhodium complex [(η5,κ2C-C5Me4CH2C6F5CH2NC3H2NMe)- RhCl] (1). 1 can be prepared in high yields from commercially available starting materials using a one-pot method. The catalyst could be separated, regenerated, and reused. Rapid quantitative fluorination generated the fluoride analogue of the active pharmaceutical ingredient probenecid. Infrared in situ monitoring verified the clean conversion of the substrates to products. VTNA graphical kinetic analysis and DFT calculations lead to a postulated reaction mechanism involving a nucleophilic Rh-F bond.

15.
Head Neck Pathol ; 15(3): 935-944, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33788136

RESUMEN

In a previous study, we found interobserver agreement among 88 board-certified pathologists evaluating perineural invasion (PNI) in oral squamous cell carcinoma (OSCC) was fair, and participants most often used the following criteria: (1) tumor invading the perineurium, (2) tumor surrounding a nerve. In this study, we aimed to determine whether application of these most commonly used criteria may improve interobserver agreement. 512 pathologists were invited to participate in a web-based survey. Participants were asked to assess the presence/absence of PNI in a set of OSCC photomicrographs by applying each of the two criteria above. The survey was completed by 84 board-certified pathologists [mean age: 52 years (range 31-81), mean years in practice: 19 (range 1-56)]. Interobserver agreement was moderate (k = 0.46, 95% CI 0.45-0.46) when using definition #1 (tumor invading the perineurium) and fair (k = 0.24, 95% CI 0.23-0.25) when using definition #2 (tumor surrounding a nerve). By comparison, interobserver agreement was fair (k = 0.36, 95% CI 0.35-0.37) among phase 1 participants asked to evaluate these photomicrographs as they would in their pathology practice. Differences in kappa between definition #1 and phase 1, definition #2 and phase 2, and definition #1 and #2 were statistically significant (p < 0.001). Compared to our prior study based on pathologists' personal views, the current study shows improved interobserver agreement with application of the criterion, "tumor invading the perineurium." However, further work is needed to delineate concise, objective, and more reproducible criteria for histopathologic assessment of PNI.


Asunto(s)
Neoplasias de Cabeza y Cuello/patología , Invasividad Neoplásica/patología , Estadificación de Neoplasias/normas , Nervios Periféricos/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Patología Quirúrgica/normas , Encuestas y Cuestionarios
16.
Endocrine ; 72(1): 27-39, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33025563

RESUMEN

OBJECTIVE: The hobnail variant of papillary thyroid carcinoma (HVPTC) has emerged as a rare and aggressive variant of papillary thyroid carcinoma (PTC). We aim to determine the prevalence and clinicopathologic factors of HVPTC. METHODS: A systematic review of the literature for studies examining HVPTC was performed. Four databases (PubMed, Scopus, OVID, Cochrane library) were queried from inception of databases through March 20th, 2020. RESULTS: Sixteen studies with 124 cases of HVPTC were included. The mean age for all patients was 52.3 years. HVPTC had a prevalence of 1.08% out of all PTC cases, with a mean tumor size of 3.1 cm. In 62% and 50% of cases, lymphovascular invasion and extrathyroidal extension were present, respectively. Follow-up data, with a mean of 49.9 months, revealed a 66% rate of lymph node metastasis and 23% rate of distant metastasis. Tumors with ≥30% hobnail morphology had a 2.6-fold increased odds of developing lymph node metastasis compared with <30% hobnail morphology, however did not differ in rates of distant metastasis. Patients ≥55 years old had a 4.5-fold increased odds of distant metastasis and a 4.7-fold increased odds of lymphovascular invasion over patients <55. CONCLUSIONS: High rates of locoregional and distant disease as well as high-risk pathological factors reveal the aggressive nature of HVPTC. Diagnostic criteria regarding percentage of hobnail morphology requires further refinement. Further studies are warranted in order to better understand how recognition of this high-risk variant impacts clinical treatment.


Asunto(s)
Carcinoma Papilar , Neoplasias de la Tiroides , Carcinoma Papilar/epidemiología , Humanos , Metástasis Linfática , Persona de Mediana Edad , Cáncer Papilar Tiroideo/epidemiología , Neoplasias de la Tiroides/epidemiología
17.
Cancers (Basel) ; 12(6)2020 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-32545409

RESUMEN

Cancers that arise in the head and neck region are comprised of a heterogeneous group of malignancies that include carcinogen- and human papillomavirus (HPV)-driven mucosal squamous cell carcinoma as well as skin cancers such as cutaneous squamous cell carcinoma, basal cell carcinoma, melanoma, and Merkel cell carcinoma. These malignancies develop in critical areas for eating, talking, and breathing and are associated with substantial morbidity and mortality despite advances in treatment. Understanding of advances in the management of these various cancers is important for all multidisciplinary providers who care for patients across the cancer care continuum. Additionally, the recent Coronavirus Disease 2019 (COVID-19) pandemic has necessitated adaptations to head and neck cancer care to accommodate the mitigation of COVID-19 risk and ensure timely treatment. This review explores advances in diagnostic criteria, prognostic factors, and management for subsites including head and neck squamous cell carcinoma and the various forms of skin cancer (basal cell carcinoma, cutaneous squamous cell carcinoma, Merkel cell carcinoma, and melanoma). Then, this review summarizes emerging developments in immunotherapy, radiation therapy, cancer survivorship, and the delivery of care during the COVID-19 era.

18.
Skeletal Radiol ; 49(12): 1987-1994, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32564102

RESUMEN

OBJECTIVE: To evaluate whether a commonly used surgical grading scale, when applied to acetabular labral findings on MRI, could improve preoperative planning and counseling for patients undergoing hip arthroscopy. MATERIALS AND METHODS: We evaluated 76 clinical MRIs performed on patients with femoroacetabular impingement. Three musculoskeletal radiologists and one musculoskeletal fellow reviewed each scan in a blinded fashion, classifying the acetabular labrum from 12:00 to 4:00 using the Beck scale, a common surgical grading scale. Clinical correlation was provided via surgical examination and classification. Reliability was determined between readers and between reader and surgical data using Cohen's kappa and Krippendorff's alpha at each clock position and for the worst grading for each scan. In addition, a simplified version of the scale comprised of only two grades, potentially reparable and not potentially reparable, was evaluated. RESULTS: When the scale was simplified into categories of potentially reparable and not potentially reparable, the sensitivity was excellent, ranging from 85.5 to 96%. Observer agreement when using individual Beck grades was found to range from poor to fair; Kappa ranged from 0.03 to 0.19, and Alpha ranged from - 0.27 to 0.22. CONCLUSION: The simplified version of the Beck labral scale when applied to MRI is a highly sensitive predictor of potentially reparable labral pathology while excluding normal and grossly degenerative tissue. Use of this scale provides clinically relevant information that can drive preoperative planning and improve patient counseling. It does so in a standardized fashion that can be applied across practice sites and without additional cost.


Asunto(s)
Cartílago Articular , Pinzamiento Femoroacetabular , Acetábulo/diagnóstico por imagen , Acetábulo/cirugía , Artroscopía , Pinzamiento Femoroacetabular/diagnóstico por imagen , Pinzamiento Femoroacetabular/cirugía , Articulación de la Cadera , Humanos , Imagen por Resonancia Magnética , Reproducibilidad de los Resultados
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA