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BACKGROUND: Coronal shear fractures of the capitellum and trochlea are relatively uncommon and can be challenging to treat because of variable articular comminution and poor bone stock. Classification is valuable to help guide surgical decision making and prognosis. The aim of this study was to present a large series of coronal shear fractures treated according to the Modified Dubberley Classification System (MDCS). METHODS: Forty-five patients with a coronal shear fracture were followed up (12-93 months, mean: 28 months) after surgical intervention. Fractures were classified according to the MDCS by 3 observers, and outcome data collected included Oxford elbow score (OES), visual analog pain score (VAS), range of motion, complications, and radiographic findings. RESULTS: There were 10 type 1, 12 type 2, 8 type 3, and 15 type 4 fractures. There were 26 subtype B fractures (posterior comminution). A total of 37 patients underwent open reduction and internal fixation (ORIF) and 8 primary arthroplasty. The median OES and VAS were 43(16-48) and 2 (0-9), respectively. Median flexion extension arc was 125° (range, 70°-140°). There was no significant difference in OES, VAS, or range of motion according to fracture type (types 1-4), subtype (type a or b), or treatment method (arthroplasty vs. ORIF). The overall complication and reoperation rates were 31% and 33%, respectively. A total of 75% of complications occurred in type 3 and 4 fractures, and there was a nonsignificant trend toward higher complication rate in type B fractures than type A fractures (34% vs. 16%, P = .19). Patients with a type B fracture who underwent screw-only fixation had a significantly lower OES and higher complication rate compared with when they had combined plating with screws (OES, P = .03; complications P = .04) and compared with when an arthroplasty was performed (OES, P = .05; complications P = .04). CONCLUSION: Consistently good outcomes can be achieved by classification and management according to the MDCS. It is recommended that type B fractures undergo combined plate and screw fixation and that type 4 fractures should be considered for arthroplasty because of the higher risk of complications with ORIF.
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Articulação do Cotovelo , Fraturas do Úmero , Placas Ósseas , Articulação do Cotovelo/diagnóstico por imagem , Articulação do Cotovelo/cirurgia , Fixação Interna de Fraturas , Humanos , Fraturas do Úmero/diagnóstico por imagem , Fraturas do Úmero/cirurgia , Úmero , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Multiple modifications of reverse total shoulder arthroplasty (RTSA) since the first Grammont design have developed to improve range of motion (ROM) and avoid notching. The effect of these changes in shoulder kinematics and the best compromise for ROM is still under debate. This computer simulation study evaluates the influence of humeral design, humeral neck-shaft angle (NSA), glenoid lateralization, and glenoid eccentricity on ROM of RTSA. METHODS: We created a 3-dimensional computer model from computed tomography scans of 13 patients with primary osteoarthritis simulating implantation of a standardized reverse shoulder arthroplasty. We analyzed the effect of 4 different variables on impingement-free ROM: humeral design (inlay vs. semi-inlay vs. onlay), humeral NSA (135° vs. 145° vs. 155°), glenoid lateralization, and glenoid eccentricity on ROM. RESULTS: The use of different humeral stem designs did not have a significant effect on total global ROM. Reducing NSA demonstrated a significant increase in adduction, and external and internal rotation in adduction, whereas a decrease in abduction and external rotation in abduction. Glenosphere lateralization was the most effective method for increasing total global ROM (P < .0001); however, extreme lateralization (+12 mm) did not show significant benefit compared with moderate lateralization (+4 mm). Glenosphere eccentricity increased only adduction and internal rotation in adduction. CONCLUSION: Only glenoid lateralization has a significant effect on increasing total global ROM in RTSA. The use of the semi-inlay 145° model combined with 4 mm lateralization and 2 mm inferior eccentricity represents the middle ground and the most universal approach in RTSA.
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Artroplastia do Ombro , Simulação por Computador , Osteoartrite/diagnóstico por imagem , Articulação do Ombro , Prótese de Ombro , Cavidade Glenoide/diagnóstico por imagem , Cavidade Glenoide/cirurgia , Humanos , Úmero/diagnóstico por imagem , Úmero/cirurgia , Imageamento Tridimensional , Osteoartrite/cirurgia , Desenho de Prótese , Amplitude de Movimento Articular , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/cirurgia , Tomografia Computadorizada por Raios XRESUMO
INTRODUCTION: Suspected septic arthritis is a common presentation to EDs. The underlying diagnosis is often non-infective pathology. Differentiating between aetiologies is difficult. A bedside test with high negative predictive value (NPV) may allow safe discharge of patients, reduce the time in the ED, hospital admission and associated costs. This study aims to evaluate the NPV of bedside leucocyte esterase (LE) in the assessment of these patients. METHODS: A prospective multicentre observational study of ED adult patients referred to orthopaedics with suspected native joint septic arthritis between October 2015 and April 2016. At three hospital sites in the Bristol region, the results of the LE test exposed to aspirated synovial fluid were recorded along with Gram stain, culture, haematinics and length of stay. A positive LE test was considered 2+ or 3+ leucocytes based on the test strip colour. Data were analysed to establish sensitivity, specificity, NPV and positive predictive value (PPV) against the gold standard 48-hour culture. We determined the potential number of inpatient bed-days that might be avoided using this bedside test. RESULTS: Eighty patients underwent joint aspiration. Five cases had positive 48-hour culture. All (5/5) infected cases showed ≥2+ LE, sensitivity of 100% (95% CI 47.8% to 100%) while the Gram stain was positive in only one case (sensitivity 20%, 95% CI 0.51% to 71.6%). Twenty-three LE were read negative or 1+, all with negative 48-hour culture results, resulting in an NPV of 100% (95% CI 82.1% to 1.00%) for a negative LE test. Specificity of a positive LE test was 30.7% (95% CI 20.5% to 42.45%) with PPV of 8.77% (95% CI 7.64% to 10.1%). It was calculated that 57 orthopaedic bed-days could have potentially been saved by immediately discharging those with a negative LE test. CONCLUSIONS: LE point-of-care testing for suspected septic arthritis of native joints has a high NPV. Implementation of LE may facilitate more rapid discharge of patients with negative results. This test has the potential to reduce diagnostic uncertainty and costs to the healthcare system.
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Artrite Infecciosa/diagnóstico , Hidrolases de Éster Carboxílico/análise , Testes Imediatos , Adulto , Idoso , Idoso de 80 Anos ou mais , Artrite Infecciosa/enzimologia , Biomarcadores/análise , Serviço Hospitalar de Emergência , Inglaterra , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e EspecificidadeRESUMO
PURPOSE: The purpose of this study was to evaluate the intermediate-term clinical and radiological outcomes for acute, unstable acromioclavicular joint (ACJ) injuries treated with the arthroscopically assisted BiPOD stabilisation technique. METHODS: Twenty-three patients who sustained acute, unstable ACJ injuries were included in this prospective study. We recorded demographics, injury classification, time to surgery, clinical scores, radiological outcomes and complications; each patient completed a minimum of 2 years post-operative observation. RESULTS: Mean follow-up was 26 months (range, 24-34). Clinical outcomes scores demonstrated good 2-year results: relative Constant score, 97.9/100; ACJ Index, 89.4/100; Subjective Shoulder Value, 92.4/100 and Taft = 11.1/12. Final C-C distance showed a mean of 0.7 mm (SD ± 1.8 mm) at 2 years. Complication rate was 9%. CONCLUSION: The BiPOD technique shows excellent, reliable intermediate-term results with a favourable complication rate compared to existing techniques; it provides a comprehensive surgical option for the stabilisation of acute ACJ injuries restoring both vertical and horizontal stability.
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Articulação Acromioclavicular , Articulação Acromioclavicular/diagnóstico por imagem , Articulação Acromioclavicular/cirurgia , Humanos , Luxações Articulares , Ligamentos Articulares , Estudos Prospectivos , Resultado do TratamentoRESUMO
Greener alternatives to synthetic polymers are constantly being investigated and sought after. Chitin is a natural polysaccharide that gives structural support to crustacean shells, insect exoskeletons, and fungal cell walls. Like cellulose, chitin resides in nanosized structural elements that can be isolated as nanofibers and nanocrystals by various top-down approaches, targeted at disintegrating the native construct. Chitin has, however, been largely overshadowed by cellulose when discussing the materials aspects of the nanosized components. This Perspective presents a thorough overview of chitin-related materials research with an analytical focus on nanocomposites and nanopapers. The red line running through the text emphasizes the use of fungal chitin that represents several advantages over the more popular crustacean sources, particularly in terms of nanofiber isolation from the native matrix. In addition, many ß-glucans are preserved in chitin upon its isolation from the fungal matrix, enabling new horizons for various engineering solutions.
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Quitina/química , Fungos/química , Nanoestruturas/química , Exoesqueleto/química , Animais , Bandagens , Celulose/química , Quitina/isolamento & purificação , Crustáceos/química , Embalagem de Alimentos , Fungos/citologia , Humanos , Polímeros/químicaRESUMO
BACKGROUND: Accurate classification and subsequent management of acromioclavicular (AC) joint injuries remains a contentious topic. The updated Rockwood classification acknowledges "stable IIIA" and "unstable IIIB" injuries, a watershed accepted by ISAKOS and important in guiding clinical management. Traditionally, the coracoclavicular distance is used to classify these injuries, despite well-documented limitations. This study aimed to evaluate displacement in AC joint injuries by measuring both coracoclavicular (CC) distance and the newly proposed acromial center line to dorsal clavicle (AC-DC) distance, in a cohort of patients, and correlate the results between the 2 measurements and relationship to Rockwood grade. MATERIALS AND METHODS: Ninety consecutive cases of AC joint injury were evaluated radiographically for Rockwood classification, CC distance on anteroposterior radiographs, and AC-DC distance on Alexander view radiographs. Inter- and intraobserver reliability for each measurement was calculated as well as correlation between the 2 measurement types and the degree to which each measurement accurately represented the Rockwood classification. RESULTS: Although both CC and AC-DC measurements showed very high inter- and intraobserver reliability, the CC distance systematically underestimated the degree of AC joint displacement when compared with the AC-DC measurement as the severity of injury increased, particularly in the presence of posterior horizontal displacement such as that seen in Rockwood IV injuries. CONCLUSION: The AC-DC measurement and use of the Alexander view provides the clinician with a more realistic appreciation of true AC joint displacement, especially in defining watershed cases (ie, IIIA/IIB/IV) and may better inform the decision-making process regarding management options and recommendations.
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Articulação Acromioclavicular/lesões , Acrômio/diagnóstico por imagem , Clavícula/diagnóstico por imagem , Processo Coracoide/diagnóstico por imagem , Luxações Articulares/diagnóstico por imagem , Instabilidade Articular/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Luxações Articulares/classificação , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Radiografia , Reprodutibilidade dos Testes , Adulto JovemRESUMO
Copper based paints are used to prevent fouling on the hulls of ships. The widely documented effect of copper on hull assemblages may be primarily due to direct effects on the invertebrates themselves or indirect effects from copper absorbed into the microbial biofilm before settlement has commenced. Artificial units of habitat were exposed to varied regimes of copper to examine (1) the photosynthetic efficiency and pigments of early-colonising biofilms, and (2) subsequent macroinvertebrate assemblage change in response to the different regimes of copper. Macroinvertebrate assemblages were found to be less sensitive to the direct effects of copper than indirect effects as delivered through biofilms that have been historically exposed to copper, with some species more tolerant than others. This raises further concern for the efficacy of copper as a universal antifoulant on the hulls of ships, which may continue to assist the invasion of copper-tolerant invertebrate species.
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Biofilmes/efeitos dos fármacos , Incrustação Biológica/prevenção & controle , Cobre/farmacologia , Fotossíntese/efeitos dos fármacos , Animais , Ecossistema , Espécies Introduzidas , Invertebrados/efeitos dos fármacos , Invertebrados/fisiologia , PinturaRESUMO
UNLABELLED: Cellular senescence is an irreversible side effect of some pharmaceuticals which can contribute to tissue degeneration. OBJECTIVE: To determine whether pharmaceutical glucocorticoids induce senescence in tenocytes. METHODS: Features of senescence (ß-galactosidase activity at pH 6 (SA-ß-gal) and active mammalian/mechanistic target of rapamycin (mTOR) in cell cycle arrest) as well as the activity of the two main pathways leading to cell senescence were examined in glucocorticoid-treated primary human tenocytes. Evidence of senescence-inducing pathway induction in vivo was obtained using immunohistochemistry on tendon biopsy specimens taken before and 7 weeks after subacromial Depo-Medrone injection. RESULTS: Dexamethasone treatment of tenocytes resulted in an increased percentage of SA-ßgal-positive cells. Levels of phosphorylated p70S6K did not decrease with glucocorticoid treatment indicating mTOR remained active. Increased levels of acetylated p53 as well as increased RNA levels of its pro-senescence effector p21 were evident in dexamethasone-treated tenocytes. Levels of the p53 deacetylase sirtuin 1 were lower in dexamethasone-treated cells compared with controls. Knockdown of p53 or inhibition of p53 activity prevented dexamethasone-induced senescence. Activation of sirtuin 1 either by exogenous overexpression or by treatment with resveratrol or low glucose prevented dexamethasone-induced senescence. Immunohistochemical analysis of tendon biopsies taken before and after glucocorticoid injection revealed a significant increase in the percentage of p53-positive cells (p=0.03). The percentage of p21-positive cells also tended to be higher post-injection (p=0.06) suggesting glucocorticoids activate the p53/p21 senescence-inducing pathway in vivo as well as in vitro. CONCLUSION: As cell senescence is irreversible in vivo, glucocorticoid-induced senescence may result in long-term degenerative changes in tendon tissue.
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Senescência Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/efeitos dos fármacos , Dexametasona/farmacologia , Glucocorticoides/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/efeitos dos fármacos , Serina-Treonina Quinases TOR/efeitos dos fármacos , Tendões/efeitos dos fármacos , Proteína Supressora de Tumor p53/efeitos dos fármacos , Adulto , Idoso , Ciclo Celular/efeitos dos fármacos , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Dexametasona/uso terapêutico , Feminino , Técnicas de Silenciamento de Genes , Glucocorticoides/uso terapêutico , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Manguito Rotador , Sirtuína 1/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Tendinopatia/tratamento farmacológico , Tendões/citologia , Tendões/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , beta-Galactosidase/efeitos dos fármacos , beta-Galactosidase/metabolismoRESUMO
BACKGROUND: Glucocorticoid injection (GCI) and surgical rotator cuff repair are two widely used treatments for rotator cuff tendinopathy. Little is known about the way in which medical and surgical treatments affect the human rotator cuff tendon in vivo. We assessed the histological and immunohistochemical effects of these common treatments on the rotator cuff tendon. STUDY DESIGN: Controlled laboratory study. METHODS: Supraspinatus tendon biopsies were taken before and after treatment from 12 patients undergoing GCI and 8 patients undergoing surgical rotator cuff repair. All patients were symptomatic and none of the patients undergoing local GCI had full thickness tears of the rotator cuff. The tendon tissue was then analysed using histological techniques and immunohistochemistry. RESULTS: There was a significant increase in nuclei count and vascularity after rotator cuff repair and not after GCI (both p=0.008). Hypoxia inducible factor 1α (HIF-1α) and cell proliferation were only increased after rotator cuff repair (both p=0.03) and not GCI. The ionotropic N-methyl-d-aspartate receptor 1 (NMDAR1) glutamate receptor was only increased after GCI and not rotator cuff repair (p=0.016). An increase in glutamate was seen in both groups following treatment (both p=0.04), while an increase in the receptor metabotropic glutamate receptor 7 (mGluR7) was only seen after rotator cuff repair (p=0.016). CONCLUSIONS: The increases in cell proliferation, vascularity and HIF-1α after surgical rotator cuff repair appear consistent with a proliferative healing response, and these features are not seen after GCI. The increase in the glutamate receptor NMDAR1 after GCI raises concerns about the potential excitotoxic tendon damage that may result from this common treatment.
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Glucocorticoides/efeitos adversos , Manguito Rotador/cirurgia , Tendinopatia/induzido quimicamente , Traumatismos dos Tendões/terapia , Adulto , Idoso , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Traumatismos em Atletas/terapia , Estudos de Casos e Controles , Proliferação de Células/fisiologia , Feminino , Glucocorticoides/administração & dosagem , Ácido Glutâmico/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Biópsia Guiada por Imagem , Imuno-Histoquímica , Injeções Intra-Articulares , Masculino , Metilprednisolona/administração & dosagem , Metilprednisolona/efeitos adversos , Metilprednisolona/análogos & derivados , Acetato de Metilprednisolona , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/metabolismo , Variações Dependentes do Observador , Receptores de N-Metil-D-Aspartato/metabolismo , Manguito Rotador/patologia , Lesões do Manguito Rotador , Dor de Ombro/terapia , Tendinopatia/patologia , Ultrassonografia de Intervenção , Cicatrização/fisiologiaRESUMO
Background: Proximal ulna fracture-dislocations are challenging injuries with a myriad of existing classification systems. The Coronoid, proximal Ulna, Radius, and Ligaments classification (CURL) is a simple framework designed to focus attention on the key components affecting outcome and guide surgical management. This study evaluates interobserver and intraobserver reliability of this new classification. Methods: Four observers independently reviewed plain radiographs and computed tomography (CT) scans of patients with proximal ulna fracture-dislocations. Each observer scored the Coronoid (C), proximal Ulna (U), and Radius (R) components for each fracture on 2 occasions. The osseous components were subclassified as 'intact', 'simple', or 'complex'. The Ligament component (L) was not rated as this requires intraoperative classification. Interobserver and intraobserver reliability was calculated using Cohen's weighted kappa coefficients. X-ray and CT were compared for patients with both imaging modalities. The Landis and Koch criteria were used to interpret the strength of the kappa statistics. Results: One hundred seventy seven patients had plain X-rays; 58 patients had both X-ray and CT scans. Overall, in the X-ray only cohort, there was 'almost perfect' interobserver reliability for the radial head (k = 0.94) and coronoid (k = 0.83), and 'substantial' reliability (k = 0.68) for the proximal ulna. For the X-ray and CT cohort, interobserver reliability was 'almost perfect' across both modalities for the radial head (k = 0.88 and k = 0.93, respectively) and 'moderate' for the proximal ulna (k = 0.48 and k = 0.52, respectively). For the coronoid, interobserver reliability for X-ray interpretation was 'substantial' (k = 0.74) and for CT was 'almost perfect' (k = 0.89). Intraobserver reliability was 'almost perfect' for all components, other than CT assessment of the proximal ulna which demonstrated 'substantial' reliability (k = 0.74). Conclusion: The Coronoid, proximal Ulna, Radius, and Ligaments classification demonstrates strong interobserver and intraobserver reliability, supporting use of the classification for proximal ulna fracture-dislocations. CT is recommended for improved characterization of any fracture with a coronoid component.
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In September 2010, the first International Scientific Tendinopathy Symposium (ISTS) was held in Umeå, Sweden, to establish a forum for original scientific and clinical insights in this growing field of clinical research and practice. The second ISTS was organised by the same group and held in Vancouver, Canada, in September 2012. This symposium was preceded by a round-table meeting in which the participants engaged in focused discussions, resulting in the following overview of tendinopathy clinical and research issues. This paper is a narrative review and summary developed during and after the second ISTS. The document is designed to highlight some key issues raised at ISTS 2012, and to integrate them into a shared conceptual framework. It should be considered an update and a signposting document rather than a comprehensive review. The document is developed for use by physiotherapists, physicians, athletic trainers, massage therapists and other health professionals as well as team coaches and strength/conditioning managers involved in care of sportspeople or workers with tendinopathy.
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Exercício Físico/fisiologia , Esportes/fisiologia , Tendinopatia/etiologia , Tendão do Calcâneo/lesões , Colúmbia Britânica , Diagnóstico por Imagem/métodos , Humanos , Dor Musculoesquelética/etiologia , Dor Musculoesquelética/reabilitação , Ligamento Patelar/lesões , Lesões do Manguito Rotador , Tendinopatia/diagnóstico , Tendinopatia/reabilitação , Traumatismos dos Tendões/diagnóstico , Traumatismos dos Tendões/etiologia , Traumatismos dos Tendões/reabilitação , Cotovelo de Tenista/etiologia , Cotovelo de Tenista/reabilitação , Resultado do TratamentoRESUMO
Climate change-related impacts have hampered the productivity of agricultural lands in recent times, affecting food security globally. Novel technology-based agricultural production systems such as controlled-environment agriculture (CEA) are a way to reduce the impact of climatic variation and pests that harm current global crop production and ensure consistent crop development. These systems often use artificial lighting and soilless mediums to produce crops. This meta-analysis has investigated the key influencing factors on crop production within these systems, using previous studies on lettuce (the most cultivated crop in these systems) to understand what affects yield within CEA. This analysis has found that on average, CEA systems yield twice that of field-based agriculture (3.68 kg m-2 vs. 1.88 kg m-2), with the most influencing factors being the variety of cultivars grown, the season, the nutrient delivery method, and the lighting type. The cultivation time for this study was 40 days, with 94% of papers having trial periods of 70 days or less, much lower than field-based agriculture (60-120 days). Vertical farming (stacked vertical CEA cultivation) studies were found to especially drive up yield per area (6.88 kg m-2). The results of this meta-analysis are useful for starting to understand the key influencing factors on CEA growth and highlight the breadth of research ongoing in the CEA industry.
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An approach is presented to include a wider range of factors involved in the nitrogen and carbon cycles in agro-ecosystems than is typical of many Life Cycle Assessments (LCAs) of agriculture-based products. This use results from the process-oriented Denitrification-Decomposition (DNDC, modified version) model. Here we evaluate the effects of using site-specific N(2)O emissions derived from the DNDC model rather than the values derived from the commonly used Intergovernmental Panel on Climate Change (IPCC) Tier 1 empirical model on the results of whole life cycle greenhouse gas (GHG) profiles for wheat-based biopolymer products. Statistical methods were also used to analyze the quality of the DNDC and IPCC outputs and to characterize the uncertainty in the GHG results. The results confirm that the GHG profiles of the wheat-derived biopolymer products are sensitive to how the agricultural system is modeled and uncertainty analyses indicate that DNDC is preferred over the IPCC Tier 1 approach for site-specific LCAs. The former allows inclusion of a wider range of important site-specific agricultural parameters in the LCA, provides for improved quality in the LCA data, and permits better calibration of uncertainty in the LCA inventory.
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Agricultura , Biopolímeros/química , Ecossistema , Gases/análise , Efeito Estufa , Modelos Químicos , Triticum/química , Poluição do Ar/análise , Amônia/análise , Dióxido de Carbono/análise , Mudança Climática , Simulação por Computador , Desnitrificação , Óxido Nítrico/análise , Óxido Nitroso/análise , Estações do Ano , IncertezaRESUMO
Hyperspectral and micro X-ray fluorescence (µXRF) imagery were used to derive maps of mineralogy and elemental chemistry from a sample of a siliceous hot spring deposit, or sinter, collected from a landslide breccia deposit at the base of the Paeroa fault, which bounds the eastern Taupo Rift at Te Kopia, Taupo Volcanic Zone, New Zealand. The sample is of a known biogenic sinter layer from a paleo-vent area of a recently extinct alkali chloride hot spring. The aim of the study was to distinguish it from other horizons derived from nonbiogenic sources, which is of relevance to early and extraterrestrial life research, specifically to help assess the potential reliability of morphology as an indicator of biology in the geological record. In particular, the distribution of opal, a common mineral in hot springs deposits that is known to preserve microbial features, and the relative abundances of Al-OH clay and water (OH and H2O) were mapped from hyperspectral imagery and element distributions defined by µXRF element mapping. Layers within the sinter sample composed of spicular geyserite-a type of micro-columnar stromatolite-showed contrasting mineralogy and water content in comparison with interspicular clastic sediment. Whereas clay was found to be concentrated in the interspicular sediment, high water contents characterized the spicules. µXRF imagery also showed differences in the composition of the two components of the spicule-bearing layers, with interspicular sediment being enriched in K, Ti, Fe, and Rb relative to the spicules, which are enriched in Ga. The contrasting nature of the mapped components highlights the detailed upward-branching nature of the spicules, identical to those found in living microstromatolites. These discriminants show that the spicular component can be discerned from the geological background through hyperspectral and µXRF mapping and used to define morphological features that may survive burial diagenesis and metamorphism as a biosignature in deep time rocks.
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Sedimentos Geológicos , Fontes Termais , Exobiologia , Nova Zelândia , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Tendons heal by fibrotic repair, increasing the likelihood of reinjury. Animal tendon injury and overuse models have identified transforming growth factor beta (TGF-ß) and bone morphogenetic proteins (BMPs) as growth factors actively involved in the development of fibrosis, by mediating extracellular matrix synthesis and cell differentiation. PURPOSE: To understand how TGF-ß and BMPs contribute to fibrotic processes using tendon-derived cells isolated from healthy and diseased human tendons. STUDY DESIGN: Controlled laboratory study. METHODS: Tendon-derived cells were isolated from patients with a chronic rotator cuff tendon tear (large to massive, diseased) and healthy hamstring tendons of patients undergoing anterior cruciate ligament repair. Isolated cells were incubated with TGF-ß1 (10 ng/mL) or BMP-2 (100 ng/mL) for 3 days. Gene expression was measured by real-time quantitative polymerase chain reaction. Cell signaling pathway activation was determined by Western blotting. RESULTS: TGF-ß1 treatment induced ACAN mRNA expression in both cell types but less in the diseased compared with healthy cells (P < .05). BMP-2 treatment induced BGN mRNA expression in healthy but not diseased cells (P < .01). In the diseased cells, TGF-ß1 treatment induced increased ACTA2 mRNA expression (P < .01) and increased small mothers against decapentaplegic (SMAD) signaling (P < .05) compared with those of healthy cells. Moreover, BMP-2 treatment induced ACTA2 mRNA expression in the diseased cells only (P < .05). CONCLUSION: Diseased tendon-derived cells show reduced expression of the proteoglycans aggrecan and biglycan in response to TGF-ß1 and BMP-2 treatments. These same treatments induced enhanced fibrotic differentiation and canonical SMAD cell signaling in diseased compared with healthy cells. CLINICAL RELEVANCE: Findings from this study suggest that diseased tendon-derived cells respond differently than healthy cells in the presence of TGF-ß1 and BMP-2. The altered responses of diseased cells may influence fibrotic repair processes during tendon healing.
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Fator de Crescimento Transformador beta1 , Fator de Crescimento Transformador beta , Animais , Proteínas Morfogenéticas Ósseas , Células Cultivadas , Humanos , Manguito Rotador , Tendões , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
BACKGROUND: Acromioclavicular joint (ACJ) injuries are common. Despite this, it remains unclear how best to assess, classify, and manage these cases. A simple, reliable, valid, and accurate radiographic parameter to measure ACJ displacement would allow improved consistency of diagnosis and subsequent treatment pathways. PURPOSE: To evaluate "the circles measurement" and associated "ABC classification" as a tool for assessing ACJ displacement and injury classification. STUDY DESIGN: Descriptive laboratory study. METHODS: The circles measurement is taken from a lateral Alexander radiograph of the shoulder. The measurement is the center-to-center distance between 2 circles drawn to define the lateral extent of the clavicle and the anteromedial extent of the acromion; it is independent of the displacement plane, judging total ACJ displacement in any direction rather than trying to quantify vertical and/or horizontal displacement. When utilized clinically, the circles measurement is a single measurement calculated as the difference between values recorded for the injured and uninjured sides. Validation of the circles measurement was performed using lateral Alexander radiographs (including ±20° projection error in all planes) and computed tomography of standardized ACJ injury simulations. We assessed inter- and intrarater reliability, convergent validity, and discriminant validity of the circles measurement and subsequently generated a classification of ACJ injury based on displacement. RESULTS: Reliability and validity of the circles measurement was excellent throughout. Interrater reliability (ICC [intraclass correlation coefficient] [2,1], 95% CI; n = 78; 4 observers) was 0.976 (0.964-0.985). Intrarater reliability (ICC [2,1]; 95% CI; n = 78; 2 measures) was 0.998 (0.996-0.998). Convergent validity (Pearson correlation coefficient, r) was 0.970 for ideal radiographs and 0.889 with ±20° projection error in all planes. Discriminant validity, with 1-way analysis of variance, showed a P value of <.0001 and effect size (η2) of 0.960, with the ability to distinguish between the previously defined stable (Rockwood IIIA) and unstable (Rockwood IIIB) injuries. The results permitted objective, statistically sound parameters for the proposed ABC classification system. CONCLUSION: The circles measurement is a simple, reliable, valid, accurate, and resilient parameter for assessing ACJ displacement and can be used in conjunction with the proposed ABC classification to define ACJ injuries more accurately and objectively than previously described. CLINICAL RELEVANCE: This novel parameter has the potential to standardize the initial assessment and possibly the subsequent clinical management of ACJ injuries, in addition to providing a standardized measure for future research.
Assuntos
Articulação Acromioclavicular , Artropatias , Luxações Articulares , Articulação Acromioclavicular/diagnóstico por imagem , Acrômio , Clavícula , Humanos , Reprodutibilidade dos TestesRESUMO
Buddleja davidii is a unique biomass that has many attractive agroenergy features, especially its wide range of growth habitat. The anatomical characteristics of B. davidii were investigated before and after ethanol organosolv pretreatment (one of the leading pretreatment technologies) in order to further understand the alterations that occur to the cellular structure of the biomass which can then be correlated with its enzymatic digestibility. Results showed that the ethanol organosolv pretreatment of B. davidii selectively removes lignin from the middle lamella (ML), which does not significantly disrupt the crystalline structure of cellulose. The removal of ML lignin is a major factor in enhancing enzymatic cellulose-to-glucose hydrolysis. The pretreatment also causes cell deformation, resulting in cracks and breaks in the cell wall. These observations, together with characterization analysis of the cell wall polymer material, lend support to the hypothesis that the physical distribution of lignin in the biomass matrix is an important structural feature affecting biomass enzymatic digestibility.
Assuntos
Biomassa , Buddleja/anatomia & histologia , Buddleja/metabolismo , Glucose/metabolismo , Extratos Vegetais/metabolismo , Buddleja/efeitos dos fármacos , Fracionamento Químico , Etanol/metabolismo , Fermentação , Lignina/isolamento & purificação , Solventes/metabolismoRESUMO
The effects of urban living on health are becoming increasingly important, due to an increasing global population residing in urban areas. Concomitantly, due to immigration, there is a growing number of ethnic minority individuals (African, Asian or Middle Eastern descent) living in westernised Higher Latitude Countries (HLC) (e.g. Europe, Canada, New Zealand). Of concern is the fact that there is already a clear vitamin D deficiency epidemic in HLC, a problem which is likely to grow as the ethnic minority population in these countries increases. This is because 25-hydroxyvitamin D (25(OH)D) status of ethnic groups is significantly lower compared to native populations. Environmental factors contribute to a high prevalence of vitamin D deficiency in HLC, particularly during the winter months when there is no sunlight of appropriate wavelength for vitamin D synthesis via the skin. Also, climatic factors such as cloud cover may reduce vitamin D status even in the summer. This may be further worsened by factors related to urban living, including air pollution, which reduces UVB exposure to the skin, and less occupational sun exposure (may vary by individual HLC). Tall building height may reduce sun exposure by making areas more shaded. In addition, there are ethnicity-specific factors which further worsen vitamin D status in HLC urban dwellers, such as low dietary intake of vitamin D from foods, lower production of vitamin D in the skin due to increased melanin and reduced skin exposure to UVB due to cultural dress style and sun avoidance. A multidisciplinary approach applying knowledge from engineering, skin photobiology, nutrition, town planning and social science is required to prevent vitamin D deficiency in urban areas. Such an approach could include reduction of air pollution, modification of sun exposure advice to emphasise spending time each day in non-shaded urban areas (e.g. parks, away from tall buildings), and advice to ethnic minority groups to increase sun exposure, take vitamin D supplements and/or increase consumption of vitamin D rich foods in a way that is safe and culturally acceptable. This review hopes to stimulate further research to assess the impact of high latitude, urban environment and ethnicity on the risk of vitamin D deficiency.
Assuntos
Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/epidemiologia , Vitamina D/análogos & derivados , Poluição do Ar/efeitos adversos , Altitude , Humanos , Estilo de Vida , Estações do Ano , Pigmentação da Pele , Luz Solar , Raios Ultravioleta , População Urbana , Vitamina D/sangueAssuntos
Atenção Primária à Saúde , Dor de Ombro , Humanos , Dor de Ombro/diagnóstico , Dor de Ombro/etiologia , OmbroRESUMO
This paper proposes the Relit Spectral Angle-Stacked Autoencoder, a novel unsupervised feature learning approach for mapping pixel reflectances to illumination invariant encodings. This work extends the Spectral Angle-Stacked Autoencoder so that it can learn a shadow-invariant mapping. The method is inspired by a deep learning technique, Denoising Autoencoders, with the incorporation of a physics-based model for illumination such that the algorithm learns a shadow invariant mapping without the need for any labelled training data, additional sensors, a priori knowledge of the scene or the assumption of Planckian illumination. The method is evaluated using datasets captured from several different cameras, with experiments to demonstrate the illumination invariance of the features and how they can be used practically to improve the performance of high-level perception algorithms that operate on images acquired outdoors.