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INTRODUCTION: Angiosarcomas in the head and neck region are aggressive tumours associated with high local recurrence and metastatic rates. We present our 17-year experience at the North of England Bone and Soft Tissue Tumour Service. METHODS: A retrospective review of our prospectively maintained database was undertaken, looking for patients diagnosed with angiosarcomas affecting the head and neck. Data were gathered using a pre-defined proforma to include demographics, histological characteristics, treatment modalities, adjuvant therapies, local recurrence, distant spread, and disease-specific survival. RESULTS: A total of 23 patients (17 males, 6 females) were identified, with a mean age of 76 years at presentation. Fourteen presented with scalp lesions, whereas the remainder arose on the face. Eighteen patients underwent resection with curative intent, whereas three received palliative radiotherapy and two received comfort-based care only. Of the patients undergoing surgery, 12 had local flap reconstruction and 6 underwent free tissue transfer. Clear resection margins were obtained in nine cases (50%). Fourteen patients (78%) presented with local recurrence after surgery, and 11 (61%) developed distant metastases. The median disease-specific survival time for patients treated with curative intent was 38 months. Eight patients had mapping biopsies ahead of their resection; however, complete resection was achieved in only two cases. DISCUSSION: Angiosarcomas of the head and neck are associated with a poor prognosis, with most patients rapidly developing local recurrence, resulting in adverse clinical outcomes. Mapping biopsies do not demonstrate a clear advantage for achieving complete surgical resection. A radical surgical approach is warranted, given the aggressiveness of the pathology. However, there remains no consensus on optimal surgical management; we recommend further synthesising studies to determine the most appropriate treatment pathway.
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Hemangiossarcoma , Neoplasias de Tecidos Moles , Masculino , Feminino , Humanos , Idoso , Hemangiossarcoma/cirurgia , Hemangiossarcoma/patologia , Resultado do Tratamento , Cabeça , Neoplasias de Tecidos Moles/cirurgia , Retalhos Cirúrgicos/patologia , Estudos Retrospectivos , Recidiva Local de Neoplasia/patologiaRESUMO
Dielectric elastomer actuators (DEAs) have been proposed as a promising technology for developing soft robotics and stretchable electronics due to their large actuation. Among available fabrication techniques, inkjet printing is a digital, mask-free, material-saving, and fast technology, making it versatile and appealing for fabricating DEA electrodes. However, there is still a lack of suitable materials for inkjet-printed electrodes. In this study, multiple carbon black (CB) inks were developed and tested as DEA electrodes inkjet-printed on acrylic membranes (VHB). Triethylene glycol monomethyl ether (TGME) and chlorobenzene (CLB) were selected to disperse CB. The inks' stability, particle size, surface tension, viscosity, electrical resistance, and printability were characterized. The DEA with Ink-TGME/CLB (mixture solvent) electrodes obtained 80.63% area strain, a new benchmark for the DEA actuation with CB powder electrodes on VHB. The novelty of this work involves the disclosure of a new ink recipe (TGME/CLB/CB) for inkjet printing that can obtain stable drop formations with a small nozzle (17 × 17 µm), high resolution (â¼25 µm, approaching the limit of drop-on-demand inkjet printing), and the largest area strain of DEAs under similar conditions, distinguishing this contribution from the previous works, which is important for the fabrication and miniaturization of DEA-based soft and stretchable electronics.
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BACKGROUND: This is Part 3 of the first consensus guidelines for optimal care of patients undergoing emergency laparotomy using an enhanced recovery after surgery (ERAS) approach. This paper addresses organizational aspects of care. METHODS: Experts in management of the high-risk and emergency general surgical patient were invited to contribute by the International ERAS® Society. PubMed, Cochrane, Embase, and MEDLINE database searches were performed for ERAS elements and relevant specific topics. Studies were selected with particular attention to randomized clinical trials, systematic reviews, meta-analyses and large cohort studies, and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation system. Recommendations were made on the best level of evidence, or extrapolation from studies on elective patients when appropriate. A modified Delphi method was used to validate final recommendations. RESULTS: Components of organizational aspects of care were considered. Consensus was reached after three rounds of a modified Delphi process. CONCLUSIONS: These guidelines are based on best current available evidence for organizational aspects of an ERAS® approach to patients undergoing emergency laparotomy and include discussion of less common aspects of care for the surgical patient, including end-of-life issues. These guidelines are not exhaustive but pull together evidence on important components of care for this high-risk patient population. As much of the evidence is extrapolated from elective surgery or emergency general surgery (not specifically laparotomy), many of the components need further evaluation in future studies.
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Recuperação Pós-Cirúrgica Melhorada , Humanos , Laparotomia , Assistência Perioperatória/métodos , Organizações , Procedimentos Cirúrgicos EletivosRESUMO
BACKGROUND: This is Part 2 of the first consensus guidelines for optimal care of patients undergoing emergency laparotomy (EL) using an Enhanced Recovery After Surgery (ERAS) approach. This paper addresses intra- and postoperative aspects of care. METHODS: Experts in aspects of management of high-risk and emergency general surgical patients were invited to contribute by the International ERAS® Society. PubMed, Cochrane, Embase, and Medline database searches were performed for ERAS elements and relevant specific topics. Studies on each item were selected with particular attention to randomized clinical trials, systematic reviews, meta-analyses, and large cohort studies and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Recommendations were made on the best level of evidence, or extrapolation from studies on elective patients when appropriate. A modified Delphi method was used to validate final recommendations. Some ERAS® components covered in other guideline papers are outlined only briefly, with the bulk of the text focusing on key areas pertaining specifically to EL. RESULTS: Twenty-three components of intraoperative and postoperative care were defined. Consensus was reached after three rounds of a modified Delphi Process. CONCLUSIONS: These guidelines are based on best available evidence for an ERAS® approach to patients undergoing EL. These guidelines are not exhaustive but pull together evidence on important components of care for this high-risk patient population. As much of the evidence is extrapolated from elective surgery or emergency general surgery (not specifically laparotomy), many of the components need further evaluation in future studies.
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Recuperação Pós-Cirúrgica Melhorada , Humanos , Cuidados Pós-Operatórios , Laparotomia , Assistência Perioperatória/métodos , Procedimentos Cirúrgicos Eletivos/métodosRESUMO
INTRODUCTION: Postoperative morbidity and mortality in patients undergoing major emergency gastrointestinal surgery are a major burden on healthcare systems. Optimal management of perioperative intravenous fluids may reduce mortality rates and improve outcomes from surgery. Previous small trials of cardiac-output guided haemodynamic therapy algorithms in patients undergoing gastrointestinal surgery have suggested this intervention results in reduced complications and a modest reduction in mortality. However, this existing evidence is based mainly on elective (planned) surgery, with little evaluation in the emergency setting. There are fundamental clinical and pathophysiological differences between the planned and emergency surgical setting which may influence the effects of this intervention. A large definitive trial in emergency surgery is needed to confirm or refute the potential benefits observed in elective surgery and to inform widespread clinical practice. METHODS: The FLO-ELA trial is a multi-centre, parallel-group, open, randomised controlled trial. 3138 patients aged 50 and over undergoing major emergency gastrointestinal surgery will be randomly allocated in a 1:1 ratio using minimisation to minimally invasive cardiac output monitoring to guide protocolised administration of intra-venous fluid, or usual care without cardiac output monitoring. The trial intervention will be carried out during surgery and for up to 6 h postoperatively. The trial is funded through an efficient design call by the National Institute for Health and Care Research Health Technology Assessment (NIHR HTA) programme and uses existing routinely collected datasets for the majority of data collection. The primary outcome is the number of days alive and out of hospital within 90 days of randomisation. Participants and those delivering the intervention will not be blinded to treatment allocation. Participant recruitment started in September 2017 with a 1-year internal pilot phase and is ongoing at the time of publication. DISCUSSION: This will be the largest contemporary randomised trial examining the effectiveness of perioperative cardiac output-guided haemodynamic therapy in patients undergoing major emergency gastrointestinal surgery. The multi-centre design and broad inclusion criteria support the external validity of the trial. Although the clinical teams delivering the trial interventions will not be blinded, significant trial outcome measures are objective and not subject to detection bias. TRIAL REGISTRATION: ISRCTN 14729158. Registered on 02 May 2017.
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Procedimentos Cirúrgicos do Sistema Digestório , Hidratação , Laparotomia , Idoso , Humanos , Pessoa de Meia-Idade , Débito Cardíaco , Hidratação/métodos , Hemodinâmica , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
We present a compression sensor based on a strain-sensitive carbon black-silicone composite cast on top of a printed circuit board with interdigitated electrodes. This results in a very sensitive and soft capacitive compression sensor not requiring a structured dielectric or compliant electrodes. We show how the optimal loading of carbon black to maximize the sensitivity depends on the type of carbon black and the stiffness of the silicone matrix. The optimal quantity of carbon black leads to a high sensitivity of 252% for an input force of 10 N (this corresponds to an input pressure of 17 kPa), without stiffening the silicone matrix or increasing the viscoelastic losses noticeably. The fabrication process of the sensors is much simpler than that of other soft capacitive sensors, and unlike carbon black-silicone resistive sensors, these capacitive sensors do not exhibit time-dependent impedance creep. They can be made thick without affecting their base capacitance or sensitivity, leading to compliant and conformable sensing interfaces suitable for a variety of applications, such as robotic tactile sensors.
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We have developed a smart dive glove that recognizes 13 static hand gestures used in diving communication. The smart glove employs five dielectric elastomer sensors to capture finger motion and implements a machine learning classifier in the onboard electronics to recognize gestures. Five basic classification algorithms are trained and assessed: the decision tree, support vector machine (SVM), logistic regression, Gaussian naïve Bayes, and multilayer perceptron. These basic classifiers were selected as they perform well in multiclass classification problems, can be trained using supervised learning, and are model-based algorithms that can be implemented on a microprocessor. The training dataset was collected from 24 participants providing for a range of different hand sizes. After training, the algorithms were evaluated in a dry environment using data collected from ten new participants to test how well they cope with new information. Furthermore, an underwater experiment was conducted to assess any impact of the underwater environment on each algorithm's classification. The results show all classifiers performed well in a dry environment. The accuracies and F1-scores range between 0.95 and 0.98, where the logistic regressor and SVM have the highest scores for both the accuracy and F1-score (0.98). The underwater results showed that all algorithms work underwater; however, the performance drops when divers must focus on buoyancy control, breathing, and diver trim.
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Gestos , Redes Neurais de Computação , Humanos , Teorema de Bayes , Algoritmos , Máquina de Vetores de SuporteRESUMO
AIM: The effect of negative pressure wound therapy (NPWT) on the pathogenesis and outcome of enteroatmospheric fistulation (EAF) in the septic open abdomen (OA) is unclear. This study compares the development and outcome of EAF following NPWT with that occurring in the absence of NPWT. METHODS: Consecutive patients admitted with EAF following abdominal sepsis at a National Reference Centre for intestinal failure between 01 January 2005 and 31 December 2015 were included in this study. Patients were divided into two groups based on those that had been treated with NPWT and those that had not (non-NPWT) and characteristics of their fistulas compared. Clinical outcomes concerning nutritional autonomy at 4 years and time to fistula development, size of abdominal wall defect and complete fistula closure were compared between groups. RESULTS: A total of 160 patients were admitted with EAF following a septic abdomen (31-NPWT and 129-non-NPWT). Median (range) time taken to fistulation after OA was longer with NPWT (18 [5-113] vs. 8 [2-60] days, p = 0.004); these patients developed a greater number of fistulas (3 [2-21] vs. 2 [1-10], p = 0.01), involving a greater length of small bowel (42.5 [15-100] cm vs. 30 [3.5-170] cm, p = 0.04) than those who did not receive NPWT. Following reconstructive surgery, nutritional autonomy was similar in both groups (77% vs. 72%) and a comparable number of patients were also fistula-free (100% vs. 97%). CONCLUSIONS: Negative pressure wound therapy appears to be associated with more complex and delayed intestinal fistulation, involving a greater length of small intestine in the septic OA. This did not, however, appear to adversely affect the overall outcome of intestinal and abdominal wall reconstruction in this study.
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Técnicas de Fechamento de Ferimentos Abdominais , Fístula Intestinal , Tratamento de Ferimentos com Pressão Negativa , Humanos , Resultado do Tratamento , Fístula Intestinal/etiologia , Fístula Intestinal/cirurgia , Cicatrização , Abdome/cirurgia , Técnicas de Fechamento de Ferimentos Abdominais/efeitos adversosRESUMO
There are a range of sphincter-preserving procedures available to treat anorectal fistula, some of which can be precluded, or rendered more optimal by specific features of fistula anatomy. Magnetic resonance imaging (MRI) is the gold standard modality for assessing anorectal fistula. To maximise clinical utility, the MRI report should accurately describe these clinically relevant features. We aimed to develop a minimum dataset for reporting MRI of anorectal fistula, in order to improve the assessment and management of these patients. A longlist of 70 potential items for the minimum dataset was generated through systematic review of the literature. This longlist was presented to radiologists, surgeons and gastroenterologists in an online survey to understand the features that shape current clinical practice. The longlist and survey results were then presented to an expert consensus panel to generate the final minimum dataset through discussion and anonymous voting. The final minimum dataset details the general characteristics, features of the internal and external openings, path of the fistula through the sphincters and any associated extensions and collections that should be described in all MRI reports for anal fistula. Additional surgical and perianal Crohn's disease subsets were developed to indicate the features that aid decision-making for these patients, in addition to a minimum dataset for the clinical request. This study represents a multi-disciplinary approach to developing a minimum dataset for MRI reporting of anal fistula, highlighting the most important features to report that can assist in clinical decision-making. KEY POINTS: ⢠This paper recommends the minimum features that should be included in all MRI reports for the assessment of anal fistula, including Parks classification, number of tracts, features of the internal and external opening, path of the tract through the sphincters, the presence and features of extensions and collections. ⢠Additional features that aid decision-making for surgery or in the presence of Crohn's disease have been identified. ⢠The items that should be included when requesting an MRI are specified.
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Doença de Crohn , Fístula Retal , Humanos , Consenso , Fístula Retal/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Tomada de Decisão ClínicaRESUMO
Dielectric elastomer generators are soft structures capable of converting mechanical energy into electrical energy. Here, we develop a theoretical model of the triangular harvesting cycle that enables the harvesting of most of the available electrical energy while not requiring active monitoring of the charge-voltage state on the DEG. This cycle is therefore interesting for small-scale generators for which a monitoring circuit would be energetically too costly. Our model enables the identification of the optimal value of the circuit's parameters such as storage capacitor and priming voltage values and show that for capacitance swings up to 6, 94% of the available electrical energy can be harvested. The model is experimentally validated with a conical generator, and the effect of non-constant deformation amplitudes is examined. Energy densities up to 46 mJcm-3 were obtained for an electric field of 50 V µm-1.
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BACKGROUND: The role of vasopressors has long been a subject of debate in microsurgery. Conventional wisdom dictates the avoidance of vasopressor use, due to concerns such as peripheral vasoconstriction, inducing vasospasm of the anastomoses, and leading to failure in perfusion. It has since become common practice in some centers to avoid intraoperative vasopressor use during free tissue transfer surgery. Recent studies have suggested that this traditional view may not be supported by clinical evidence. However, none of these studies have separated vasopressor use by method of administration. METHODS: We conducted a retrospective review of our experience of vasopressor use in free flap surgery at a single high-volume center. The outcome measures were flap failure, flap-related complications and overall postoperative complications (reported using the Clavien-Dindo classification). Groups were compared using Chi-square or Fisher's Exact test where appropriate. RESULTS: A total of 777 cases in 717 patients were identified. 59.1% of these had vasopressors administered intraoperatively. The overall failure rate was 2.2%, with 9.8% experienced flap-related complications. There was no difference in flap loss when vasopressors were administered, but an increased rate of microvascular thrombosis was noted (p = 0.003). Continuous administration of vasopressors was associated with reduced venous congestion, whereas intermittent boluses increased risk of microvascular thrombosis. CONCLUSION: Our study confirms previous findings that intraoperative vasopressor use in free flap surgery is not associated with increased failure rate. Administering vasopressors continuously may be safer than via repeated boluses.
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Retalhos de Tecido Biológico , Procedimentos de Cirurgia Plástica , Humanos , Cuidados Intraoperatórios , Complicações Pós-Operatórias/tratamento farmacológico , Estudos Retrospectivos , Vasoconstritores/uso terapêuticoRESUMO
Physiological loading is essential for the maintenance of articular cartilage through the regulation of tissue remodeling. To correctly understand the behavior of chondrocytes in their native environment, cell stimulating devices and bioreactors have been developed to examine the effect of mechanical stimuli on chondrocytes. This study describes the design and validation of a novel system for analyzing chondrocyte deformation patterns. This involves an in vitro mechanical device for a controlled application of multi-axial-loading regimes to chondrocyte-seeded agarose constructs and in silico models for analyzing chondrocyte deformation patterns. The computer-controlled device precisely applies compressive, tensile, and shear strains to hydrogel constructs using a customizable macro-based program. The synchronization of the displacements is shown to be accurate with a 1.2% error and is highly reproducible. The device design allows housing for up to eight novel designed free-swelling three-dimensional hydrogel constructs. Constructs include mesh ends and are optimized to withstand the application of up to 7% mechanical tensile and 15% shear strains. Constructs were characterized through mapping the strain within as mechanical load was applied and was validated using light microscopy methods, chondrocyte viability using live/dead imaging, and cell deformation strains. Images were then analyzed to determine the complex deformation strain patterns of chondrocytes under a range of dynamic mechanical stimulations. This is one of the first systems that have characterized construct strains to cellular strains. The features in this device make the system ideally suited for a systematic approach for the investigation of the response of chondrocytes to a complex physiologically relevant deformation profile.
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CondrócitosRESUMO
BACKGROUND: Enhanced Recovery After Surgery (ERAS) protocols reduce length of stay, complications and costs for a large number of elective surgical procedures. A similar, structured approach appears to improve outcomes, including mortality, for patients undergoing high-risk emergency general surgery, and specifically emergency laparotomy. These are the first consensus guidelines for optimal care of these patients using an ERAS approach. METHODS: Experts in aspects of management of the high-risk and emergency general surgical patient were invited to contribute by the International ERAS® Society. Pubmed, Cochrane, Embase, and MEDLINE database searches on English language publications were performed for ERAS elements and relevant specific topics. Studies on each item were selected with particular attention to randomized controlled trials, systematic reviews, meta-analyses and large cohort studies, and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Recommendations were made on the best level of evidence, or extrapolation from studies on non-emergency patients when appropriate. The Delphi method was used to validate final recommendations. The guideline has been divided into two parts: Part 1-Preoperative Care and Part 2-Intraoperative and Postoperative management. This paper provides guidelines for Part 1. RESULTS: Twelve components of preoperative care were considered. Consensus was reached after three rounds. CONCLUSIONS: These guidelines are based on the best available evidence for an ERAS approach to patients undergoing emergency laparotomy. Initial management is particularly important for patients with sepsis and physiological derangement. These guidelines should be used to improve outcomes for these high-risk patients.
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Recuperação Pós-Cirúrgica Melhorada , Procedimentos Cirúrgicos Eletivos , Humanos , Laparotomia , Tempo de Internação , Assistência Perioperatória , Complicações Pós-Operatórias , Cuidados Pré-OperatóriosRESUMO
Soft robots, devices with deformable bodies and powered by soft actuators, may fill a hitherto unexplored niche in outer space. All space-bound payloads are heavily limited in terms of mass and volume, due to the cost of launch and the size of spacecraft. Being constructed from stretchable materials allows many possibilities for compacting soft robots for launch and later deploying into a much larger volume, through folding, rolling, and inflation. This morphability can also be beneficial for adapting to operation in different environments, providing versatility, and robustness. To be truly soft, a robot must be powered by soft actuators. Dielectric elastomer transducers (DETs) offer many advantages as artificial muscles. They are lightweight, have a high work density, and are capable of artificial proprioception. Taking inspiration from nature, in particular the starfish podia, we present here bio-inspired inflatable DET actuators powering low-mass robots capable of performing complex motion that can be compacted to a fraction of their operating size.
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In this contribution, a soft sensor configuration based on silicone foam is developed to measure compressive forces in the range of 50 N with the aim of providing proprioceptive capabilities to conventional robotic manipulators based on hard materials. This then makes them capable of interacting with soft and fragile objects without damage. The concept relies on interdigitated electrodes that are patterned on the backside of the sensor to generate a fringing electric field into a soft compressible polymeric foam. The deformation of the foam causes changes to relative permittivity as the air-filled cells compress. The model in this article shows how the different parameters of the foam, such as air volume fraction, permittivity, and Young's modulus, affect the stiffness and electrical sensitivity of the sensor, and how controlling the porosity of the foam is key to optimizing the sensitivity of the sensor. This sensor is easy to fabricate and does not require compliant electrodes, while exhibiting high sensitivity values of 33% capacitance change for as little as 10 N applied force.
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Procedimentos Cirúrgicos Robóticos , Robótica , Capacitância Elétrica , Pressão , SiliconesRESUMO
Various types of artificial skins have been developed to provide robots with a sense of touch. Because of their compliance, dielectric elastomer (DE) capacitive sensors are particularly suitable for soft robots. Although the electrodes of DE sensors exhibit nonlinear effects such as transient resistance changes and resistance peaks, this does not affect the capacitance readout representing stretch, as long as the frequency of the excitation voltage used for capacitance measurement is sufficiently low. At higher frequencies, however, the approximation of a DE sensor with an ideal capacitor and a series resistor accounting for electrode resistivity leads to an underestimation of capacitance in static sensors. We demonstrate how this effect is amplified by peaks and transient changes of electrode resistance caused by periodic stretching. At high frequencies, distinctive capacitance undershoots occurred that correlated with the change of electrode resistance. The close match between a simulation of the DE sensor as an R-C transmission line and recorded data supports the hypothesis of the undershoot having been caused by dynamic electrode resistance changes and the lumped parameter approximation. Our results show that nonlinear responses in DE sensors can be avoided by appropriately adjusting the excitation frequency.
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OBJECTIVES: This study used national audit data to describe current management and outcomes of patients undergoing surgery for complications of peptic ulcer disease (PUD), including perforation and bleeding. It was also planned to explore factors associated with fatal outcome after surgery for perforated ulcers. These analyses were designed to provide a thorough understanding of current practice and identify potentially modifiable factors associated with outcome as targets for future quality improvement. DESIGN: National cohort study using National Emergency Laparotomy Audit (NELA) data. SETTING: English and Welsh hospitals within the National Health Service. PARTICIPANTS: Adult patients admitted as an emergency with perforated or bleeding PUD between December 2013 and November 2015. INTERVENTIONS: Laparotomy for bleeding or perforated peptic ulcer. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was 60-day in-hospital mortality. Secondary outcomes included length of postoperative stay, readmission and reoperation rate. RESULTS: 2444 and 382 procedures were performed for perforated and bleeding ulcers, respectively. In-hospital 60-day mortality rates were 287/2444 (11.7%, 95% CI 10.5% to 13.1%) for perforations, and 68/382 (17.8%, 95% CI 14.1% to 22.0%) for bleeding. Median (IQR) 2-year institutional volume was 12 (7-17) and 2 (1-3) for perforation and bleeding, respectively. In the exploratory analysis, age, American Society of Anesthesiology score and preoperative systolic blood pressure were associated with mortality, with no association with time from admission to operation, surgeon grade or operative approach. CONCLUSIONS: Patients undergoing surgery for complicated PUD face a high 60-day mortality risk. Exploratory analyses suggested fatal outcome was primarily associated with patient rather than provider care factors. Therefore, it may be challenging to reduce mortality rates further. NELA data provide important benchmarking for patient consent and has highlighted low institutional volume and high mortality rates after surgery for bleeding peptic ulcers as a target for future research and improvement.
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Tratamento de Emergência , Úlcera Péptica Hemorrágica/cirurgia , Úlcera Péptica Perfurada/cirurgia , Idoso , Tratamento de Emergência/mortalidade , Tratamento de Emergência/estatística & dados numéricos , Feminino , Mortalidade Hospitalar , Humanos , Laparoscopia/mortalidade , Laparoscopia/estatística & dados numéricos , Masculino , Auditoria Médica , Pessoa de Meia-Idade , Úlcera Péptica Hemorrágica/mortalidade , Úlcera Péptica Perfurada/mortalidade , Cuidados Pós-Operatórios/estatística & dados numéricos , Cuidados Pré-Operatórios/estatística & dados numéricos , Fatores de Risco , Medicina Estatal/estatística & dados numéricos , Resultado do Tratamento , Reino UnidoRESUMO
Entirely soft robots with animal-like behavior and integrated artificial nervous systems will open up totally new perspectives and applications. To produce them, we must integrate control and actuation in the same soft structure. Soft actuators (e.g., pneumatic and hydraulic) exist but electronics are hard and stiff and remotely located. We present novel soft, electronics-free dielectric elastomer oscillators, which are able to drive bioinspired robots. As a demonstrator, we present a robot that mimics the crawling motion of the caterpillar, with an integrated artificial nervous system, soft actuators and without any conventional stiff electronic parts. Supplied with an external DC voltage, the robot autonomously generates all signals that are necessary to drive its dielectric elastomer actuators, and it translates an in-plane electromechanical oscillation into a crawling locomotion movement. Therefore, all functional and supporting parts are made of polymer materials and carbon. Besides the basic design of this first electronic-free, biomimetic robot, we present prospects to control the general behavior of such robots. The absence of conventional stiff electronics and the exclusive use of polymeric materials will provide a large step toward real animal-like robots, compliant human machine interfaces, and a new class of distributed, neuron-like internal control for robotic systems.
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Elastômeros , Robótica , Biomimética , Desenho de EquipamentoRESUMO
Halorubrum lacusprofundi is an extreme halophile within the archaeal phylum Euryarchaeota. The type strain ACAM 34 was isolated from Deep Lake, Antarctica. H. lacusprofundi is of phylogenetic interest because it is distantly related to the haloarchaea that have previously been sequenced. It is also of interest because of its psychrotolerance. We report here the complete genome sequence of H. lacusprofundi type strain ACAM 34 and its annotation. This genome is part of a 2006 Joint Genome Institute Community Sequencing Program project to sequence genomes of diverse Archaea.
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We have developed a novel cell stretching device (called Cell Gym) capable of applying physiologically relevant low magnitude strains to tenocytes on a collagen type I coated membrane. We validated our device thoroughly on two levels: (1) substrate strains, (2) cell level strains. Our cell level strain results showed that the applied stretches were transferred to cells accurately (â¼90%). Our gene expression data showed that mechanically stimulated tenocytes (4%) expressed a lower level of COL I gene. COX2 gene was increased but did not reach statistical significance. Our device was then tested to see if it could reproduce results from an in vivo study that measured time-dependent changes in collagen synthesis. Our results showed that collagen synthesis peaked at 24 hrs after exercise and then decreased, which matched the results from the in vivo study. Our study demonstrated that it is important to incorporate physiologically relevant low strain magnitudes in in vitro cell mechanical studies and the need to validate the device thoroughly to operate the device at small strains. This device will be used in designing novel tendon tissue engineering scaffolds in the future.