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1.
Colorectal Dis ; 25(1): 111-117, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36031878

RESUMO

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.


Assuntos
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 adversos
2.
World J Surg ; 47(8): 1881-1898, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37277506

RESUMO

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.


Assuntos
Recuperação Pós-Cirúrgica Melhorada , Humanos , Laparotomia , Assistência Perioperatória/métodos , Organizações , Procedimentos Cirúrgicos Eletivos
3.
World J Surg ; 47(8): 1850-1880, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37277507

RESUMO

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.


Assuntos
Recuperação Pós-Cirúrgica Melhorada , Humanos , Cuidados Pós-Operatórios , Laparotomia , Assistência Perioperatória/métodos , Procedimentos Cirúrgicos Eletivos/métodos
4.
Eur Radiol ; 32(12): 8306-8316, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35732929

RESUMO

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.


Assuntos
Doença de Crohn , Fístula Retal , Humanos , Consenso , Fístula Retal/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Tomada de Decisão Clínica
5.
J Reconstr Microsurg ; 38(1): 75-83, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34229352

RESUMO

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.


Assuntos
Retalhos de Tecido Biológico , Procedimentos de Cirurgia Plástica , Humanos , Cuidados Intraoperatórios , Complicações Pós-Operatórias/tratamento farmacológico , Estudos Retrospectivos , Vasoconstritores/uso terapêutico
6.
Macromol Rapid Commun ; 42(5): e2000560, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33274814

RESUMO

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.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Capacitância Elétrica , Pressão , Silicones
7.
World J Surg ; 45(5): 1272-1290, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33677649

RESUMO

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.


Assuntos
Recuperação Pós-Cirúrgica Melhorada , Procedimentos Cirúrgicos Eletivos , Humanos , Laparotomia , Tempo de Internação , Assistência Perioperatória , Complicações Pós-Operatórias , Cuidados Pré-Operatórios
8.
J Biomech Eng ; 143(8)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33972989

RESUMO

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.


Assuntos
Condrócitos
9.
Nature ; 499(7459): 431-7, 2013 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-23851394

RESUMO

Genome sequencing enhances our understanding of the biological world by providing blueprints for the evolutionary and functional diversity that shapes the biosphere. However, microbial genomes that are currently available are of limited phylogenetic breadth, owing to our historical inability to cultivate most microorganisms in the laboratory. We apply single-cell genomics to target and sequence 201 uncultivated archaeal and bacterial cells from nine diverse habitats belonging to 29 major mostly uncharted branches of the tree of life, so-called 'microbial dark matter'. With this additional genomic information, we are able to resolve many intra- and inter-phylum-level relationships and to propose two new superphyla. We uncover unexpected metabolic features that extend our understanding of biology and challenge established boundaries between the three domains of life. These include a novel amino acid use for the opal stop codon, an archaeal-type purine synthesis in Bacteria and complete sigma factors in Archaea similar to those in Bacteria. The single-cell genomes also served to phylogenetically anchor up to 20% of metagenomic reads in some habitats, facilitating organism-level interpretation of ecosystem function. This study greatly expands the genomic representation of the tree of life and provides a systematic step towards a better understanding of biological evolution on our planet.


Assuntos
Archaea/classificação , Archaea/genética , Bactérias/classificação , Bactérias/genética , Metagenômica , Filogenia , Archaea/isolamento & purificação , Archaea/metabolismo , Bactérias/isolamento & purificação , Bactérias/metabolismo , Ecossistema , Genoma Arqueal/genética , Genoma Bacteriano/genética , Metagenoma/genética , Dados de Sequência Molecular , Análise de Sequência de DNA , Análise de Célula Única
10.
Nucleic Acids Res ; 42(Database issue): D560-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24165883

RESUMO

The Integrated Microbial Genomes (IMG) data warehouse integrates genomes from all three domains of life, as well as plasmids, viruses and genome fragments. IMG provides tools for analyzing and reviewing the structural and functional annotations of genomes in a comparative context. IMG's data content and analytical capabilities have increased continuously since its first version released in 2005. Since the last report published in the 2012 NAR Database Issue, IMG's annotation and data integration pipelines have evolved while new tools have been added for recording and analyzing single cell genomes, RNA Seq and biosynthetic cluster data. Different IMG datamarts provide support for the analysis of publicly available genomes (IMG/W: http://img.jgi.doe.gov/w), expert review of genome annotations (IMG/ER: http://img.jgi.doe.gov/er) and teaching and training in the area of microbial genome analysis (IMG/EDU: http://img.jgi.doe.gov/edu).


Assuntos
Bases de Dados Genéticas , Genoma Microbiano , Vias Biossintéticas/genética , Perfilação da Expressão Gênica , Genoma Arqueal , Genoma Bacteriano , Genoma Viral , Genômica , Internet , Anotação de Sequência Molecular , Plasmídeos/genética , Proteômica , Software , Integração de Sistemas
11.
J Biomech Eng ; 138(12)2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27379605

RESUMO

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 (∼90%). 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.


Assuntos
Biomimética/instrumentação , Mecanotransdução Celular/fisiologia , Sistemas Microeletromecânicos/instrumentação , Micromanipulação/instrumentação , Tenócitos/fisiologia , Alicerces Teciduais , Animais , Tamanho Celular , Células Cultivadas , Colágeno/biossíntese , Força Compressiva/fisiologia , Módulo de Elasticidade/fisiologia , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Estimulação Física/instrumentação , Ratos , Ratos Wistar , Estresse Mecânico , Tenócitos/citologia , Resistência à Tração/fisiologia
12.
Nature ; 462(7276): 1056-60, 2009 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-20033048

RESUMO

Sequencing of bacterial and archaeal genomes has revolutionized our understanding of the many roles played by microorganisms. There are now nearly 1,000 completed bacterial and archaeal genomes available, most of which were chosen for sequencing on the basis of their physiology. As a result, the perspective provided by the currently available genomes is limited by a highly biased phylogenetic distribution. To explore the value added by choosing microbial genomes for sequencing on the basis of their evolutionary relationships, we have sequenced and analysed the genomes of 56 culturable species of Bacteria and Archaea selected to maximize phylogenetic coverage. Analysis of these genomes demonstrated pronounced benefits (compared to an equivalent set of genomes randomly selected from the existing database) in diverse areas including the reconstruction of phylogenetic history, the discovery of new protein families and biological properties, and the prediction of functions for known genes from other organisms. Our results strongly support the need for systematic 'phylogenomic' efforts to compile a phylogeny-driven 'Genomic Encyclopedia of Bacteria and Archaea' in order to derive maximum knowledge from existing microbial genome data as well as from genome sequences to come.


Assuntos
Archaea/classificação , Archaea/genética , Bactérias/classificação , Bactérias/genética , Genoma Arqueal/genética , Genoma Bacteriano/genética , Filogenia , Actinas/química , Sequência de Aminoácidos , Proteínas de Bactérias/química , Biodiversidade , Bases de Dados Genéticas , Genes de RNAr/genética , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Alinhamento de Sequência
13.
Nucleic Acids Res ; 40(Database issue): D123-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22086953

RESUMO

The integrated microbial genomes and metagenomes (IMG/M) system provides support for comparative analysis of microbial community aggregate genomes (metagenomes) in a comprehensive integrated context. IMG/M integrates metagenome data sets with isolate microbial genomes from the IMG system. IMG/M's data content and analytical capabilities have been extended through regular updates since its first release in 2007. IMG/M is available at http://img.jgi.doe.gov/m. A companion IMG/M systems provide support for annotation and expert review of unpublished metagenomic data sets (IMG/M ER: http://img.jgi.doe.gov/mer).


Assuntos
Bases de Dados Genéticas , Metagenoma , Metagenômica , Sistemas de Gerenciamento de Base de Dados , Eucariotos/genética , Genoma Arqueal , Genoma Bacteriano , Genoma Viral , Plasmídeos/genética , Integração de Sistemas
14.
Nucleic Acids Res ; 40(Database issue): D115-22, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22194640

RESUMO

The Integrated Microbial Genomes (IMG) system serves as a community resource for comparative analysis of publicly available genomes in a comprehensive integrated context. IMG integrates publicly available draft and complete genomes from all three domains of life with a large number of plasmids and viruses. IMG provides tools and viewers for analyzing and reviewing the annotations of genes and genomes in a comparative context. IMG's data content and analytical capabilities have been continuously extended through regular updates since its first release in March 2005. IMG is available at http://img.jgi.doe.gov. Companion IMG systems provide support for expert review of genome annotations (IMG/ER: http://img.jgi.doe.gov/er), teaching courses and training in microbial genome analysis (IMG/EDU: http://img.jgi.doe.gov/edu) and analysis of genomes related to the Human Microbiome Project (IMG/HMP: http://www.hmpdacc-resources.org/img_hmp).


Assuntos
Bases de Dados Genéticas , Genoma Arqueal , Genoma Bacteriano , Genoma Viral , Genômica , Eucariotos/genética , Fenótipo , Plasmídeos/genética , Proteômica , Software , Integração de Sistemas
15.
J Plast Reconstr Aesthet Surg ; 88: 452-456, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38091688

RESUMO

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.


Assuntos
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/patologia
16.
Soft Robot ; 10(4): 687-700, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36917166

RESUMO

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.

17.
IEEE Trans Neural Netw Learn Syst ; 34(12): 9874-9886, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35439141

RESUMO

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.


Assuntos
Gestos , Redes Neurais de Computação , Humanos , Teorema de Bayes , Algoritmos , Máquina de Vetores de Suporte
18.
ACS Appl Mater Interfaces ; 15(35): 41992-42003, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37611072

RESUMO

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 (∼25 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.

19.
Trials ; 24(1): 313, 2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37149623

RESUMO

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.


Assuntos
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 Assunto
20.
J Bacteriol ; 194(20): 5703-4, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23012283

RESUMO

Desulfurococcus fermentans is the first known cellulolytic archaeon. This hyperthermophilic and strictly anaerobic crenarchaeon produces hydrogen from fermentation of various carbohydrates and peptides without inhibition by accumulating hydrogen. The complete genome sequence reported here suggested that D. fermentans employs membrane-bound hydrogenases and novel glycohydrolases for hydrogen production from cellulose.


Assuntos
DNA Arqueal/química , DNA Arqueal/genética , Desulfurococcaceae/genética , Genoma Arqueal , Análise de Sequência de DNA , Anaerobiose , Metabolismo dos Carboidratos , Celulose/metabolismo , Desulfurococcaceae/isolamento & purificação , Desulfurococcaceae/fisiologia , Fermentação , Água Doce/microbiologia , Fontes Termais/microbiologia , Hidrogênio/metabolismo , Dados de Sequência Molecular , Federação Russa
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