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BACKGROUND: Adenoma detection with polypectomy during total colonoscopy reduces the incidence of colorectal cancer (CRC) and colorectal cancer-associated mortality. The adenoma detection rate (ADR) is an established quality indicator, which is associated with a decreased risk for interval cancer. An increase in ADR could be demonstrated for several artificially intelligent, real-time computer-aided detection (CADe) systems in selected patients. Most studies concentrated on outpatient colonoscopies. This sector often lacks funds for applying costly innovations like CADe. Hospitals are more likely to implement CADe and information about the impact of CADe in the distinct patient cohort of hospitalized patients is scarce. METHODS: In this prospective, randomized-controlled study, we compared colonoscopies performed with or without computer-aided detection (CADe) system (GI Genius, Medtronic) performed at University Medical Center Schleswig-Holstein, Campus Luebeck. The primary endpoint was ADR. RESULTS: Overall, 232 patients were randomized with n = 122 patients in the CADe arm and n = 110 patients in the control arm. Median age was 66 years (interquartile range 51-77). Indication for colonoscopy was most often workup for gastrointestinal symptoms (88.4%) followed by screening, post-polypectomy and post-CRC surveillance (each 3.9%). Withdrawal time was significantly prolonged (11 vs. 10 min, p = 0.039), without clinical relevance. Complication rate was not different between the arms (0.8% vs. 4.5%; p = 0.072). The ADR was significantly increased in the CADe arm compared to the control (33.6% vs. 18.1%, p = 0.008). ADR increase was particularly strong for the detection in elderly patients aged ≥50 years (OR 6.3, 95% CI 1.7 - 23.1, p = 0.006). CONCLUSION: The use of CADe is safe and increases ADR in hospitalized patients.
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Adenoma , Pólipos do Colo , Neoplasias Colorretais , Idoso , Humanos , Estudos Prospectivos , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Colonoscopia , Computadores , Adenoma/diagnóstico , Adenoma/epidemiologia , Pólipos do Colo/diagnósticoRESUMO
Increasing farmers' adoption of sustainable nitrogen management practices is crucial for improving water quality. Yet, research to date provides ambiguous results about the most important farmer-level drivers of adoption, leaving high levels of uncertainty as to how to design policy interventions that are effective in motivating adoption. Among others, farmers' engagement in outreach or educational events is considered a promising leverage point for policy measures. This paper applies a Bayesian belief network (BBN) approach to explore the importance of drivers thought to influence adoption, run policy experiments to test the efficacy of different engagement-related interventions on increasing adoption rates, and evaluate heterogeneity of the effect of the interventions across different practices and different types of farms. The underlying data comes from a survey carried out in 2018 among farmers in the Central Valley in California. The analyses identify farm characteristics and income consistently as the most important drivers of adoption across management practices. The effect of policy measures strongly differs according to the nitrogen management practice. Innovative farmers respond better to engagement-related policy measures than more traditional farmers. Farmers with small farms show more potential for increasing engagement through policy measures than farmers with larger farms. Bayesian belief networks, in contrast to linear analysis methods, always account for the complex structure of the farm system with interdependencies among the drivers and allow for explicit predictions in new situations and various kinds of heterogeneity analyses. A methodological development is made by introducing a new validation measure for BBNs used for prediction.
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Fazendeiros , Nitrogênio , Agricultura , Teorema de Bayes , Fazendas , Humanos , PolíticasRESUMO
BACKGROUND: Due to the increasing threat by terrorism and the resulting range of operations for the emergency medical service, the equipment as well as the rescue strategies are being adapted and expanded. An example is the "Recommended Action for Emergency Medical Services in Special Operations" (REBEL, Handlungsempfehlung für Rettungsdienst bei besonderen Einsatzlagen) of the highest Bavarian rescue service authority. In the following article, three cases are presented using new tools such as hemostyptics, thoracic patches and tourniquet from the REBEL kit in everyday operations. CASES: The first case deals with a seriously injured driver involved in a truck accident suffering from a scalping violation of the facial skeleton with consecutive critical bleeding (use of hemostyptics-coated dressings). The second case describes an accident with a reinforcing steel perforating a builder's chest. After removal of the perforating steel by first aiders, the two open thoracic wounds are supplied with thoracic closure patches. The third case deals with an amputation injury of the lower leg after a traffic accident (use of tourniquet). DISCUSSION: The most common causes of death besides bleeding that can be prevented in patients with severe injuries and multiple trauma are tension pneumothorax and airway obstruction. These diagnoses can be identified and treated properly using the
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Tratamento de Emergência , Traumatismo Múltiplo/terapia , Terrorismo , Acidentes de Trânsito , Adulto , Bandagens , Escala de Coma de Glasgow , Hemostáticos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Choque Hemorrágico/terapia , Traumatismos Torácicos/terapia , TorniquetesRESUMO
OBJECTIVE: To characterize en face features of the retinal pigment epithelium (RPE) and choroid in eyes with chronic central serous chorioretinopathy (CSCR) using a high-speed, enhanced-depth swept-source optical coherence tomography (SS-OCT) prototype. DESIGN: Consecutive patients with chronic CSCR were prospectively examined with SS-OCT. PARTICIPANTS: Fifteen eyes of 13 patients. METHODS: Three-dimensional 6×6 mm macular cube raster scans were obtained with SS-OCT operating at 1050 nm wavelength and 100000 A-lines/sec with 6 µm axial resolution. Segmentation of the RPE generated a reference surface; en face SS-OCT images of the RPE and choroid were extracted at varying depths every 3.5 µm (1 pixel). Abnormal features were characterized by systematic analysis of multimodal fundus imaging, including color photographs, fundus autofluorescence, fluorescein angiography, and indocyanine-green angiography (ICGA). MAIN OUTCOME MEASURES: En face SS-OCT morphology of the RPE and individual choroidal layers. RESULTS: En face SS-OCT imaging at the RPE level revealed absence of signal corresponding to RPE detachment or RPE loss in 15 of 15 (100%) eyes. En face SS-OCT imaging at the choriocapillaris level showed focally enlarged vessels in 8 of 15 eyes (53%). At the level of Sattler's layer, en face SS-OCT documented focal choroidal dilation in 8 of 15 eyes (53%) and diffuse choroidal dilation in 7 of 15 eyes (47%). At the level of Haller's layer, these same features were observed in 3 of 15 eyes (20%) and 12 of 15 eyes (80%), respectively. In all affected eyes, these choroidal vascular abnormalities were seen just below areas of RPE abnormalities. In 2 eyes with secondary choroidal neovascularization (CNV), distinct en face SS-OCT features corresponded to the neovascular lesions. CONCLUSIONS: High-speed, enhanced-depth SS-OCT at 1050 nm wavelength enables the visualization of pathologic features of the RPE and choroid in eyes with chronic CSCR not usually appreciated with standard spectral domain (SD) OCT. En face SS-OCT imaging seems to be a useful tool in the identification of CNV without the use of angiography. This in vivo documentation of the RPE and choroidal vasculature at variable depths may help elucidate the pathophysiology of disease and can contribute to the diagnosis and management of chronic CSCR.
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Coriorretinopatia Serosa Central/diagnóstico , Corioide/patologia , Epitélio Pigmentado da Retina/patologia , Tomografia de Coerência Óptica , Doença Crônica , Corantes , Feminino , Angiofluoresceinografia , Humanos , Verde de Indocianina , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Acuidade VisualRESUMO
PURPOSE: To detect and quantify choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD) using optical coherence tomography (OCT) angiography. DESIGN: Observational, cross-sectional study. PARTICIPANTS: A total of 5 normal subjects and 5 subjects with neovascular AMD were included. METHODS: A total of 5 eyes with neovascular AMD and 5 normal age-matched controls were scanned by a high-speed (100 000 A-scans/seconds) 1050-nm wavelength swept-source OCT. The macular angiography scan covered a 3 × 3-mm area and comprised 200 × 200 × 8 A-scans acquired in 3.5 seconds. Flow was detected using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. Motion artifacts were removed by 3-dimensional (3D) orthogonal registration and merging of 4 scans. The 3D angiography was segmented into 3 layers: inner retina (to show retinal vasculature), outer retina (to identify CNV), and choroid. En face maximum projection was used to obtain 2-dimensional angiograms from the 3 layers. The CNV area and flow index were computed from the en face OCT angiogram of the outer retinal layer. Flow (decorrelation) and structural data were combined in composite color angiograms for both en face and cross-sectional views. MAIN OUTCOME MEASURES: The CNV angiogram, CNV area, and CNV flow index. RESULTS: En face OCT angiograms of CNV showed sizes and locations that were confirmed by fluorescein angiography (FA). Optical coherence tomography angiography provided more distinct vascular network patterns that were less obscured by subretinal hemorrhage. The en face angiograms also showed areas of reduced choroidal flow adjacent to the CNV in all cases and significantly reduced retinal flow in 1 case. Cross-sectional angiograms were used to visualize CNV location relative to the retinal pigment epithelium and Bruch's layer and classify type I and type II CNV. A feeder vessel could be identified in 1 case. Higher flow indexes were associated with larger CNV and type II CNV. CONCLUSIONS: Optical coherence tomography angiography provides depth-resolved information and detailed images of CNV in neovascular AMD. Quantitative information regarding CNV flow and area can be obtained. Further studies are needed to assess the role of quantitative OCT angiography in the evaluation and treatment of neovascular AMD.
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Neovascularização de Coroide/diagnóstico , Angiofluoresceinografia , Tomografia de Coerência Óptica , Degeneração Macular Exsudativa/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Velocidade do Fluxo Sanguíneo , Neovascularização de Coroide/fisiopatologia , Estudos Transversais , Feminino , Voluntários Saudáveis , Humanos , Imageamento Tridimensional , Masculino , Projetos Piloto , Degeneração Macular Exsudativa/fisiopatologiaRESUMO
PURPOSE: To compare optic disc perfusion between normal subjects and subjects with glaucoma using optical coherence tomography (OCT) angiography and to detect optic disc perfusion changes in glaucoma. DESIGN: Observational, cross-sectional study. PARTICIPANTS: Twenty-four normal subjects and 11 patients with glaucoma were included. METHODS: One eye of each subject was scanned by a high-speed 1050-nm-wavelength swept-source OCT instrument. The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to compute 3-dimensional optic disc angiography. A disc flow index was computed from 4 registered scans. Confocal scanning laser ophthalmoscopy (cSLO) was used to measure disc rim area, and stereo photography was used to evaluate cup/disc (C/D) ratios. Wide-field OCT scans over the discs were used to measure retinal nerve fiber layer (NFL) thickness. MAIN OUTCOME MEASURES: Variability was assessed by coefficient of variation (CV). Diagnostic accuracy was assessed by sensitivity and specificity. Comparisons between glaucoma and normal groups were analyzed by Wilcoxon rank-sum test. Correlations among disc flow index, structural assessments, and visual field (VF) parameters were assessed by linear regression. RESULTS: In normal discs, a dense microvascular network was visible on OCT angiography. This network was visibly attenuated in subjects with glaucoma. The intra-visit repeatability, inter-visit reproducibility, and normal population variability of the optic disc flow index were 1.2%, 4.2%, and 5.0% CV, respectively. The disc flow index was reduced by 25% in the glaucoma group (P = 0.003). Sensitivity and specificity were both 100% using an optimized cutoff. The flow index was highly correlated with VF pattern standard deviation (R(2) = 0.752, P = 0.001). These correlations were significant even after accounting for age, C/D area ratio, NFL, and rim area. CONCLUSIONS: Optical coherence tomography angiography, generated by the new SSADA, repeatably measures optic disc perfusion and may be useful in the evaluation of glaucoma and glaucoma progression.
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Angiofluoresceinografia , Glaucoma/fisiopatologia , Disco Óptico/irrigação sanguínea , Vasos Retinianos/fisiologia , Tomografia de Coerência Óptica , Idoso , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Estudos Transversais , Feminino , Glaucoma/classificação , Voluntários Saudáveis , Humanos , Imageamento Tridimensional , Pressão Intraocular , Fluxometria por Laser-Doppler , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/patologia , Oftalmoscopia , Fluxo Sanguíneo Regional , Reprodutibilidade dos Testes , Células Ganglionares da Retina/patologia , Sensibilidade e Especificidade , Testes de Campo Visual , Campos VisuaisRESUMO
BACKGROUND: Cardioembolic stroke (CES) due to atrial fibrillation (AF) is associated with high stroke mortality. Oral anticoagulation (OAC) reduces stroke mortality, however, the impact of OAC-administration during hospital stay post ischemic stroke on mortality is unclear. We determined whether the timing of OAC initiation among other prognostic factors influenced mortality after CES. METHODS: Within the Ludwigshafen Stroke Study (LuSSt), a prospective population-based stroke register, we analysed all patients with a first ever ischemic stroke or TIA due to AF from 2006 until 2010. We analysed whether treatment or non-treatment with OAC and initiation of OAC-therapy during and after hospitalization influenced stroke mortality within 500 days after stroke/TIA due to AF. RESULTS: In total 479 patients had a first-ever ischemic stroke (n = 394) or TIA (n = 85) due to AF. One-year mortality rate was 28.4%. Overall, 252 patients (52.6%) received OAC. In 181 patients (37.8%), OAC treatment was started in hospital and continued thereafter. Recommendation to start OAC post discharge was given in 110 patients (23.0%) of whom 71 patients received OAC with VKA (14.8%). No OAC-recommendation was given in 158 patients (33.0%). In multivariate Cox regression analysis, higher age (HR 1.04; 95% CI 1.02-1.07), coronary artery disease (HR: 1.6; 95% CI 1.1-2.3), higher mRS-score at discharge (HR 1.24; 95% CI 1.09-1.4), and OAC treatment ((no OAC vs started in hospital (HR: 5.4; 95% CI 2.8-10.5), were independently associated with stroke mortality. OAC-timing did not significantly influence stroke mortality (started post discharge vs. started in hospital (HR 0.3; 95% CI 0.07-1.4)). CONCLUSIONS: OAC non-treatment is the main predictor for stroke mortality. Although OAC initiation during hospital stay showed a trend towards higher mortality, early initiation in selected patients is an option as recommendation to start OAC post hospital was implemented in only 64.5%. This rate might be elevated by implementation of special intervention programs.
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Anticoagulantes/farmacologia , Sistema de Registros , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/mortalidade , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/administração & dosagem , Fibrilação Atrial/complicações , Gerenciamento Clínico , Feminino , Alemanha/epidemiologia , Humanos , Ataque Isquêmico Transitório , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Acidente Vascular Cerebral/etiologia , Resultado do TratamentoRESUMO
BACKGROUND: In order to continue to efficiently provide both personnel-intensive and resource-intensive care to severely injured patients, some hospitals have introduced individually differentiated systems for resuscitation room treatment. The aim of this study was to evaluate the concept of the A and B classifications in terms of practicability, indications, and potential complications at a national trauma center in Bavaria. METHODS: In a retrospective study, data from resuscitation room trauma patients in the year 2020 were collected. The assignment to A and B was made by the prehospital emergency physician. Parameters such as the injury severity score (ISS), Glasgow outcome scale (GOS), upgrade rate, and the indication criteria according to the S3 guidelines were recorded. Statistical data comparisons were made using ttests, χ2-tests, or Mann-Whitney Utests. RESULTS: A total of 879 resuscitation room treatments (A 473, B 406) met the inclusion criteria. It was found that 94.5% of resuscitation room A cases had physician accompaniment, compared to 48% in resuscitation room B assignments. In addition to significantly lower ISS scores (4.1 vs. 13.9), 29.8% of B patients did not meet the treatment criteria defined in the S3 guidelines. With a low upgrade rate of 4.9%, 98% of B patients had a GOS score of 4 or 5. CONCLUSION: The presented categorization is an effective and safe way to manage the increasing number of resuscitation room alerts in a resource-optimized manner.
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Ressuscitação , Centros de Traumatologia , Humanos , Estudos Retrospectivos , Escala de Gravidade do Ferimento , Cuidados CríticosRESUMO
BACKGROUND: Transcatheter edge-to-edge repair for severe tricuspid regurgitation (TR) is a new treatment option (t-TEER). Data on optimal antithrombotic therapy after t-TEER in patients with an indication for anticoagulation are scarce and evidence-based guideline recommendations are lacking. We sought to investigate efficacy and safety of novel oral anticoagulation (NOAC) and vitamin-K-antagonists (VKA) in patients undergoing t-TEER. METHODS: Among 78 consecutive patients with t-TEER of severe TR, 69 patients were identified with concomitant indication for oral anticoagulation. Outcomes of these patients treated with NOAC or VKA were compared over a median follow-up period of 327 (177-460) days. RESULTS: Despite elevated thromboembolic and bleeding risk scores (CHA2DS2-VASc 4.2 ± 1.1, HEMORR2HAGES 3.0 ± 1.0 and HAS-BLED 2.1 ± 0.8), only one major bleeding incidence occurred under NOAC therapy. The risk for overall (NOAC 8% vs. VKA group 26%, p = 0.044) and major bleeding events (NOAC 2% vs. VKA 21%, p = 0.010) was significantly lower in the NOAC compared to the VKA group. No significant difference was found between NOAC and VKA treatment in terms of mortality (NOAC 18% vs. VKA 16%, p = 0.865) or the combined endpoint of death, heart failure hospitalization, stroke, embolism, thrombosis, myocardial infarction, and severe bleeding (NOAC 48% vs. VKA 42%, p = 0.801). A comparison between apixaban (n = 27) and rivaroxaban (n = 16) treated patients revealed no significant differences between NOAC substances (all bleeding events apixaban 7% vs. rivaroxaban 13%, p = 0.638). CONCLUSION: Results of this study indicate that NOACs may offer a favorable risk-benefit profile for patients with concomitant indication for anticoagulation therapy following t-TEER.
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We demonstrate high speed, swept source optical coherence microscopy (OCM) using a MEMS tunable vertical cavity surface-emitting laser (VCSEL) light source. The light source had a sweep rate of 280 kHz, providing a bidirectional axial scan rate of 560 kHz. The sweep bandwidth was 117 nm centered at 1310 nm, corresponding to an axial resolution of 13.1 µm in air, corresponding to 8.1 µm (9.6 µm spectrally shaped) in tissue. Dispersion mismatch from different objectives was compensated numerically, enabling magnification and field of view to be easily changed. OCM images were acquired with transverse resolutions between 0.86 µm - 3.42 µm using interchangeable 40X, 20X and 10X objectives with ~600 µm x 600 µm, ~1 mm x 1 mm and ~2 mm x 2 mm field-of-view (FOV), respectively. Parasitic variations in path length with beam scanning were corrected numerically. These features enable swept source OCM to be integrated with a wide range of existing scanning microscopes. Large FOV mosaics were generated by serially acquiring adjacent overlapping microscopic fields and combining them in post-processing. Fresh human colon, thyroid and kidney specimens were imaged ex vivo and compared to matching histology sections, demonstrating the ability of OCM to image tissue specimens.
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Aumento da Imagem/instrumentação , Lasers , Iluminação/instrumentação , Microscopia/instrumentação , Tomografia de Coerência Óptica/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , HumanosRESUMO
Background and study aims Only a few studies are available regarding endoscopic vacuum-assisted closure (E-VAC) therapy for the post-surgery leakage of the lower gastrointestinal tract. Patients and methods In this multicenter German study, we retrospectively analyzed patients treated with E-VAC therapy due to post-surgery leakage of the lower gastrointestinal tract from 2000-2020âat Hannover Medical School, University Medical Center Schleswig-Holstein, Campus Luebeck, and Robert Koch Hospital Gehrden. Results Overall, 147 patients were included in this study. Most patients had undergone tumor resections of the lower gastrointestinal tract (nâ=â88; 59.9â%). Median time to diagnosis of leakage was 10 days (interquartile range [IQR] 6-19). Median duration of E-VAC therapy was 14 days (IQR 8-27). Increase of C-reactive protein (CRP) levels significantly correlated with first diagnosis of leakage ( P â<â0.001). E-VAC therapy led to closure or complete epithelialization of leakage in the majority of patients (nâ=â122; 83.0â%) and stoma reversal was achieved in 60.0â%. Stoma reversal was significantly more often achieved in patients with CRP levels ≤â100âmg/L at first diagnosis compared to patients with CRP levels >â100âmg/L (78.4â% vs. 52.7â%; P â=â0.012). Odds ratio for failure of stoma reversal was 3.36 in cases with CRP valuesâ>â100âmg/L ( P â=â0.017). In total, leakage- and/ or E-VAC therapy-associated complications occurred in 26 patients (17.7â%). Minor complications included recurrent E-VAC dislocations and subsequent stenosis. Overall, 14 leakage- or E-VAC-associated deaths were observed most often due to sepsis. Conclusions E-VAC therapy due to post-surgery leakage of the lower gastrointestinal tract is safe and effective. High levels of CRP are a negative predictor of E-VAC therapy success.
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As the number of coronary computed tomography angiography (CTA) examinations is expected to increase, technologies to optimize the imaging workflow are of great interest. The aim of this study was to investigate the potential of artificial intelligence (AI) to improve clinical workflow and diagnostic accuracy in high-volume cardiac imaging centers. A total of 120 patients (79 men; 62.4 (55.0-72.7) years; 26.7 (24.9-30.3) kg/m2) undergoing coronary CTA were randomly assigned to a standard or an AI-based (human AI) coronary analysis group. Severity of coronary artery disease was graded according to CAD-RADS. Initial reports were reviewed and changes were classified. Both groups were similar with regard to age, sex, body mass index, heart rate, Agatston score, and CAD-RADS. The time for coronary CTA assessment (142.5 (106.5-215.0) s vs. 195.0 (146.0-265.5) s; p < 0.002) and the total reporting time (274.0 (208.0-377.0) s vs. 350 (264.0-445.5) s; p < 0.02) were lower in the human AI than in the standard group. The number of cases with no, minor, or CAD-RADS relevant changes did not differ significantly between groups (52, 7, 1 vs. 50, 8, 2; p = 0.80). AI-based analysis significantly improves clinical workflow, even in a specialized high-volume setting, by reducing CTA analysis and overall reporting time without compromising diagnostic accuracy.
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BACKGROUND: When advanced heart failure occurs in cardiac amyloidosis, prognosis is poor. In this setting heart transplantation (HTX) is a treatment option for selected patients. We here present the results of post-transplantation outcomes in cardiac amyloidosis within the Eurotransplant area, investigating possible predictors of survival. METHODS: Of 115 patients undergoing HTX due to cardiac amyloidosis in the Eurotransplant region between November 1987 and May 2020, detailed assessment prior to transplantation was available in 85 patients. The present study was conducted in a retrospective approach. Primary endpoint was mortality after HTX. Baseline variables were entered in a Cox proportional hazards model with the primary endpoint as a dependent variable. RESULTS: Median overall survival following HTX was 6.3 years in the overall collective and the subgroup. Univariate Cox proportional hazards model revealed a significant relationship between overall survival and the transplantation period (2008 to 2020 vs 1987 to 2007; median survival 9.7 years vs 1.8 years, hazard ratio 0.45, p = 0.01). Further predictors were albumin concentration (hazard ratio 0.92, p < 0.001), and systolic blood pressure (hazard ratio 0.96, p < 0.001). The transplant period as well as albumin concentration remained significant independent predictors in the AL sub cohort in a multivariate Cox proportional hazards model. CONCLUSIONS: HTX is a viable treatment option for patients at an advanced stage of cardiac amyloidosis as overall survival after transplantation has improved in the modern age. Patients at a very advanced stage of the disease, indicated by low serum albumin and blood pressure, show worse outcomes following HTX. Optimal timing and careful patient selection may therefore be particularly important to further improve post-HTX survival in amyloidosis patients.
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Amiloidose , Insuficiência Cardíaca , Transplante de Coração , Humanos , Estudos Retrospectivos , Transplante de Coração/efeitos adversos , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/cirurgia , Amiloidose/complicações , Amiloidose/cirurgia , AlbuminasRESUMO
Amplitude decorrelation measurement is sensitive to transverse flow and immune to phase noise in comparison to Doppler and other phase-based approaches. However, the high axial resolution of OCT makes it very sensitive to the pulsatile bulk motion noise in the axial direction. To overcome this limitation, we developed split-spectrum amplitude-decorrelation angiography (SSADA) to improve the signal-to-noise ratio (SNR) of flow detection. The full OCT spectrum was split into several narrower bands. Inter-B-scan decorrelation was computed using the spectral bands separately and then averaged. The SSADA algorithm was tested on in vivo images of the human macula and optic nerve head. It significantly improved both SNR for flow detection and connectivity of microvascular network when compared to other amplitude-decorrelation algorithms.
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Angiografia/métodos , Tomografia de Coerência Óptica/métodos , Algoritmos , Humanos , Imageamento Tridimensional , Macula Lutea/irrigação sanguínea , Disco Óptico/irrigação sanguínea , Razão Sinal-Ruído , Análise EspectralRESUMO
The paper presents research regarding a thermally supported multi-material clinching process (hotclinching) for metal and thermoplastic composite (TPC) sheets: an experimental approach to investigate the flow pressing phenomena during joining. Therefore, an experimental setup is developed to compress the TPC-specimens in out-of-plane direction with different initial TPC thicknesses and varying temperature levels. The deformed specimens are analyzed with computed tomography to investigate the resultant inner material structure at different compaction levels. The results are compared in terms of force-compaction-curves and occurring phenomena during compaction. The change of the material structure is characterized by sliding phenomena and crack initiation and growth.
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The steroid sapogenin diosgenin is a well-known natural product with a plethora of described pharmacological activities including the amelioration of T helper 17 (Th17)-driven pathologies. However, the exact underlying mode of action of diosgenin leading to a dampened Th17 response is still largely unknown and specific molecular targets have yet to be identified. Here, we show that diosgenin acts as a direct ligand and inverse agonist of the nuclear receptor retinoic acid receptor (RAR)-related orphan receptor (ROR)α and RORγ, which are key transcription factors involved in Th17 cell differentiation and metabolism. IC50 values determined by luciferase reporter gene assays, employing constructs for either RORγ-Gal4 fusion proteins or full length receptors, were in the low micromolar range at around 2 µM. To highlight the functional consequences of this RORα/γ inverse agonism, we determined gene expression levels of important ROR target genes, i.e., IL-17A and glucose-6-phosphatase, in relevant cellular in vitro models of Jurkat T and HepG2 cells, respectively, by RT-qPCR (reverse transcription quantitative PCR). Thereby, it was shown that diosgenin leads to a dose-dependent decrease in target gene expressions consistent with its potent cellular ROR inverse agonistic activity. Additionally, in silico dockings of diosgenin to the ROR ligand-binding domain were performed to determine the underlying binding mode. Taken together, our results establish diosgenin as a novel, direct and dual-selective RORα/γ inverse agonist. This finding establishes a direct molecular target for diosgenin for the first time, which can further explain reported amendments in Th17-driven diseases by this compound.
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BACKGROUND: Policies on waste disposal in Europe are heterogeneous and rapidly changing, with potential health implications that are largely unknown. We conducted a health impact assessment of landfilling and incineration in three European countries: Italy, Slovakia and England. METHODS: A total of 49 (Italy), 2 (Slovakia), and 11 (England) incinerators were operating in 2001 while for landfills the figures were 619, 121 and 232, respectively. The study population consisted of residents living within 3 km of an incinerator and 2 km of a landfill. Excess risk estimates from epidemiological studies were used, combined with air pollution dispersion modelling for particulate matter (PM10) and nitrogen dioxide (NO2). For incinerators, we estimated attributable cancer incidence and years of life lost (YoLL), while for landfills we estimated attributable cases of congenital anomalies and low birth weight infants. RESULTS: About 1,000,000, 16,000, and 1,200,000 subjects lived close to incinerators in Italy, Slovakia and England, respectively. The additional contribution to NO2 levels within a 3 km radius was 0.23, 0.15, and 0.14 µg/m3, respectively. Lower values were found for PM10. Assuming that the incinerators continue to operate until 2020, we are moderately confident that the annual number of cancer cases due to exposure in 2001-2020 will reach 11, 0, and 7 in 2020 and then decline to 0 in the three countries in 2050. We are moderately confident that by 2050, the attributable impact on the 2001 cohort of residents will be 3,621 (Italy), 37 (Slovakia) and 3,966 (England) YoLL. The total exposed population to landfills was 1,350,000, 329,000, and 1,425,000 subjects, respectively. We are moderately confident that the annual additional cases of congenital anomalies up to 2030 will be approximately 2, 2, and 3 whereas there will be 42, 13, and 59 additional low-birth weight newborns, respectively. CONCLUSIONS: The current health impacts of landfilling and incineration can be characterized as moderate when compared to other sources of environmental pollution, e.g. traffic or industrial emissions, that have an impact on public health. There are several uncertainties and critical assumptions in the assessment model, but it provides insight into the relative health impact attributable to waste management.
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Poluentes Atmosféricos/toxicidade , Anormalidades Congênitas/epidemiologia , Incineração , Recém-Nascido de Baixo Peso , Expectativa de Vida , Neoplasias/epidemiologia , Eliminação de Resíduos , Adolescente , Adulto , Idoso , Poluentes Atmosféricos/análise , Criança , Pré-Escolar , Coleta de Dados , Inglaterra/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Eslováquia/epidemiologia , Adulto JovemRESUMO
Product miniaturisation and functional integration are currently global trends to save weight, space, materials and costs. This leads to an increasing demand for metallic micro components. Thus, the development of appropriate production technologies is in the focus of current research activities. Due to its efficiency, accuracy and short cycle times, microforming at room temperature offers the potential to meet the steadily increasing demand. During microforming, size effects occur which negatively affect the part quality, process stability, tool life and handling. Within this contribution, a multi-stage bulk microforming process from sheet metal is investigated for the materials Cu-OFE and AA6014 with regard to the basic feasibility and the occurrence of size effects. The results reveal that the process chain is basically suitable to produce metallic micro parts with a high repeatability. Size effects are identified during the process. Since several studies postulate that size effects can be minimised by scaling down the metallic grain structure, the grain size of the aluminium material AA6014-W is scaled down to less than one micrometre by using an accumulative roll bonding process (ARB). Subsequently, the effects of the ultrafine grain (UFG) structure on the forming process are analysed. It could be shown that a strengthened material state increases the material utilization. Furthermore, too soft materials can cause damage on the part during ejection. The occurring size effects cannot be eliminated by reducing the grain size.
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Compared to alternative production methods, cold forming offers technological, economic and ecological potential for the mass production of microgears. Within the current boundaries of the technology, the cold forming of modules m < 0.2 mm is not possible due to size effects, high tool stresses and handling problems. The investigations of this contribution present a novel process chain for the multi-step forming of microgears with a module of m = 0.1 mm. For this purpose, a numerical model of the first two steps of the process chain is set up and confirmed based on experimental forming tests. The results have proven the feasibility of the process chain by a complete forming of the gear teeth.