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BACKGROUND: Portal hypertension is a common diagnosis in Sub-Saharan African countries, with the majority of patients presenting late. This study aimed to understand Clinical characteristics, aetiology, the treatment offered in our setting, and factors associated with portal hypertension at a tertiary-level hospital, in Tanzania. METHODOLOGY: A prospective cross-sectional observational single hospital-based study was conducted at MNH, from May 2021 to April 2022. A minimum of 152 subjects were required with an error of less than 5% and a study power of 80% at a 95% confidence interval. A structured questionnaire was used to collect data. Ethical clearance was obtained from the MUHAS/MNH IRB. RESULTS: A total of 154 eligible participants consented and participated in this study. The mean age of participants was 42 ± 15.8 years (range 2-87). Most of the study participants were males 64.9% with a male-to-female (M: F) ratio of 1.8:1. Vomiting blood was the common symptom among the study participants 51.3%. Schistosomiasis 53.9% and viral infection 26.6% were the common etiologies followed by alcohol abuse 7.8%. Most were medically treated at 89.61% followed by radiological treatment at 8.44% while only 1.95% of patients received surgical treatment. There was a significant association between the grade of oesophagal varices and bleeding consequences (p-value < 0.01). CONCLUSION: The majority of patients were medically treated while patients who require surgical care are unable to assess it. We recommend the establishment of a transplant services program to counteract the unmet need and more retrospective research toward policy establishment.
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Hipertensão Portal , Humanos , Masculino , Feminino , Hipertensão Portal/diagnóstico , Hipertensão Portal/terapia , Hipertensão Portal/fisiopatologia , Hipertensão Portal/epidemiologia , Hipertensão Portal/etiologia , Tanzânia/epidemiologia , Adulto , Estudos Transversais , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem , Idoso , Adolescente , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Fatores de Risco , Varizes Esofágicas e Gástricas/terapia , Varizes Esofágicas e Gástricas/diagnóstico , Varizes Esofágicas e Gástricas/etiologia , Resultado do Tratamento , Centros de Atenção Terciária , Hemorragia Gastrointestinal/terapia , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/epidemiologiaRESUMO
This study aimed to assess the potential of banana-plantain stalk fibers (BPSF) as a raw material for ropes and fabrics used in composites and geotextiles. Fibers were obtained by Biological retting and ropes used for geotextile weaving were obtained by three-strand twisting in order to optimize the mechanical properties of geostalk. The thermal, physical, chemical and mechanical characteristics of the fibers were studied in order to assess the impact of the extraction process on fiber performance. In addition, the microstructure of fibers and ropes was analyzed using Scanning Electron Microscopy (SEM) and the results highlighted the presence of cellulose microfibrils parallel to fiber axis and hemicellulose linked by lignin matrix. These constituents are organized in three concentric layers around the lumen. Elementary chemical analyses using X-ray energy dispersion (EDS), Fourier Transform Infrared (FTIR) and chemical deconstruction using Jayme-Wise protocol were carried out to determine the chemical composition of BPSF, which consists of 51.5 % Carbon, 47.07 % Oxygen and mineral salts that can be highly contribute to soil fertilization after degradation. These chemical constituents represent 40 % cellulose, 21.5 % hemicellulose, 24 % lignin, 0.34 % pectin, 7.2 % lip soluble extractable and 7.36 % water-soluble sugars present in BPSF. Thermal properties of BPSF have been investigated showing the initial degradation around 200 °C. Physical analysis and uniaxial tensile testing were performed to determine the multi-scale physical and mechanical properties of geostalk. Statistical evaluation using Weibull distribution established an increasing rate of physical and mechanical properties from the finest scale to the macroscopic scale. Thus, from the BPSF to the ropes, titer increases from 42.5 ± 4.5 g/km to 7983.4 ± 132 g/km and elongation at break increases from 0.75 ± 0.29 mm for the fibers to 52.42 ± 18.91 mm for geostalk. With mass per unit area of 1869 g/m2, the tensile stress of 1281.05 ± 273 MPa and maximum strength of 15.4 ± 1.74 kN/m, geostalk is a sustainable woven fabric alternative to geosynthetics for soil reinforcement as other limited lifespan geotextiles (geojute, geocoir and geosisal). In addition, the thermal stability and high mechanical properties of fibers and ropes suggest their potential application as reinforced phases in composite materials.
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The methanogenic strain Mx-05T was isolated from the human fecal microbiome. A phylogenetic analysis based on the 16S rRNA gene and protein marker genes indicated that the strain is affiliated with the order Methanomassiliicoccales. It shares 86.9% 16S rRNA gene sequence identity with Methanomassiliicoccus luminyensis, the only member of this order previously isolated. The cells of Mx-05T were non-motile cocci, with a diameter range of 0.4-0.7 µm. They grew anaerobically and reduced methanol, monomethylamine, dimethylamine, and trimethylamine into methane, using H2 as an electron donor. H2/CO2, formate, ethanol, and acetate were not used as energy sources. The growth of Mx-05T required an unknown medium factor(s) provided by Eggerthella lenta and present in rumen fluid. Mx-05T grew between 30 °C and 40 °C (optimum 37 °C), over a pH range of 6.9-8.3 (optimum pH 7.5), and between 0.02 and 0.34 mol.L-1 NaCl (optimum 0.12 mol.L-1 NaCl). The genome is 1.67 Mbp with a G+C content of 55.5 mol%. Genome sequence annotation confirmed the absence of the methyl branch of the H4MPT Wood-Ljungdahl pathway, as described for other Methanomassiliicoccales members. Based on an average nucleotide identity analysis, we propose strain Mx-05T as being a novel representative of the order Methanomassiliicoccales, within the novel family Methanomethylophilaceae, for which the name Methanomethylophilus alvi gen. nov, sp. nov. is proposed. The type strain is Mx-05T (JCM 31474T).
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Toxoplasma gondii is a widespread single-celled intracellular eukaryotic apicomplexan protozoan parasite primarily associated with mammalian foetal impairment and miscarriage, including in humans. Is estimated that approximately one third of the human population worldwide is infected by this parasite. Here we used cutting-edge, label-free 3D quantitative optical diffraction holotomography to capture and evaluate the Toxoplasma lytic cycle (invasion, proliferation and egress) in real-time based on the refractive index distribution. In addition, we used this technology to analyse an engineered CRISPR-Cas9 Toxoplasma mutant to reveal differences in cellular physical properties when compared to the parental line. Collectively, these data support the use of holotomography as a powerful tool for the study of protozoan parasites and their interactions with their host cells.
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Toxoplasma , Humanos , Animais , Toxoplasma/genética , Deleção de Genes , Eucariotos , Células Eucarióticas , Feto , MamíferosRESUMO
Diathermy-induced explosions in the gastrointestinal tract can occur during laparotomy and can be fatal. Hydrogen and methane are the most common flammable gases that are produced in the gastrointestinal tract. A 35-year-old male was referred to a tertiary hospital with abdominal pain after being assaulted and stabbed in the abdomen. He presented with a 2-cm wound in the midline below the xiphoid process and with an omentum protruding through the wound. Explorative laparotomy was done to repair the jejunal perforation, but a gastric blast occurred, making more than half of the gastric pouch non-viable. The operation was converted to a near-total gastrectomy with Roux-en-Y gastrojejunostomy. During open abdominal surgery, fires and explosions can occur. Precautions should be taken during open abdominal surgery to reduce the risk of explosions, such as allowing combustible gases to exit the cavity before using diathermy.
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Importance: Best-corrected visual acuity (BCVA) is a measure used to manage diabetic macular edema (DME), sometimes suggesting development of DME or consideration of initiating, repeating, withholding, or resuming treatment with anti-vascular endothelial growth factor. Using artificial intelligence (AI) to estimate BCVA from fundus images could help clinicians manage DME by reducing the personnel needed for refraction, the time presently required for assessing BCVA, or even the number of office visits if imaged remotely. Objective: To evaluate the potential application of AI techniques for estimating BCVA from fundus photographs with and without ancillary information. Design, Setting, and Participants: Deidentified color fundus images taken after dilation were used post hoc to train AI systems to perform regression from image to BCVA and to evaluate resultant estimation errors. Participants were patients enrolled in the VISTA randomized clinical trial through 148 weeks wherein the study eye was treated with aflibercept or laser. The data from study participants included macular images, clinical information, and BCVA scores by trained examiners following protocol refraction and VA measurement on Early Treatment Diabetic Retinopathy Study (ETDRS) charts. Main Outcomes: Primary outcome was regression evaluated by mean absolute error (MAE); the secondary outcome included percentage of predictions within 10 letters, computed over the entire cohort as well as over subsets categorized by baseline BCVA, determined from baseline through the 148-week visit. Results: Analysis included 7185 macular color fundus images of the study and fellow eyes from 459 participants. Overall, the mean (SD) age was 62.2 (9.8) years, and 250 (54.5%) were male. The baseline BCVA score for the study eyes ranged from 73 to 24 letters (approximate Snellen equivalent 20/40 to 20/320). Using ResNet50 architecture, the MAE for the testing set (n = 641 images) was 9.66 (95% CI, 9.05-10.28); 33% of the values (95% CI, 30%-37%) were within 0 to 5 letters and 28% (95% CI, 25%-32%) within 6 to 10 letters. For BCVA of 100 letters or less but more than 80 letters (20/10 to 20/25, n = 161) and 80 letters or less but more than 55 letters (20/32 to 20/80, n = 309), the MAE was 8.84 letters (95% CI, 7.88-9.81) and 7.91 letters (95% CI, 7.28-8.53), respectively. Conclusions and Relevance: This investigation suggests AI can estimate BCVA directly from fundus photographs in patients with DME, without refraction or subjective visual acuity measurements, often within 1 to 2 lines on an ETDRS chart, supporting this AI concept if additional improvements in estimates can be achieved.
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Diabetes Mellitus , Retinopatia Diabética , Edema Macular , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Edema Macular/diagnóstico , Edema Macular/tratamento farmacológico , Edema Macular/fisiopatologia , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/tratamento farmacológico , Retinopatia Diabética/complicações , Inibidores da Angiogênese/uso terapêutico , Inteligência Artificial , Fator A de Crescimento do Endotélio Vascular , Acuidade Visual , Algoritmos , Diabetes Mellitus/tratamento farmacológicoAssuntos
Leishmania , Leishmaniose , Parasitos , Animais , Humanos , Leishmania/genética , Leishmaniose/parasitologia , Insetos Vetores/parasitologia , SimbioseRESUMO
BACKGROUND: Human milk oligosaccharides (HMOs) are the third most abundant component of human milk. Various factors may affect the concentration of HMOs, such as the lactation period, Lewis blood type, and the maternal secretor gene status. OBJECTIVES: The purpose of this study is to investigate factors associated with HMO concentrations in Chinese populations. METHODS: A sub-sample of 481 was randomly selected from a large cross-sectional study in China (n = 6481) conducted in eight provinces (Beijing, Heilongjiang, Shanghai, Yunnan, Gansu, Guangdong, Zhejiang, and Shandong) between 2011 and 2013. HMO concentrations were determined by a high-throughput UPLC-MRM method. Various factors were collected through face-to-face interviews. Anthropometric measurement was conducted by trained staff. RESULTS: Median total HMO concentration was 13.6 g/L, 10.7 g/L, and 6.0 g/L for colostrum, transitional milk, and mature milk, respectively. HMO concentration decreased significantly as the lactation period increased (p < 0.0001). There were significant differences of average total HMO concentration between secretor mothers and non-secretor mothers (secretor 11.3 g/L vs. non-secretor 5.8 g/L, p < 0.0001). There were significant differences of average total HMO concentrations among three Lewis blood types (p = 0.003). Comparing with the concentration of total oligosaccharides of Le+ (a-b+), average of total oligosaccharides concentrations increased by 3.9 (Le+ (a+b-), p = 0.004) and 1.1 g/L (Le- (a-b-), p = 0.049). The volume of breast milk expressed and the province the mother came from affected the concentration of total oligosaccharides (all p < 0.0001). Maternal BMI (p = 0.151), age (p = 0.630), prematurity (p = 0.850), mode of delivery (p = 0.486), infants' gender (p = 0.685), maternal education level (p = 0.989), maternal occupation (p = 0.568), maternal allergic history (p = 0.370), maternal anemia (p = 0.625), pregnancy-induced hypertension (p = 0.739), gestational diabetes (p = 0.514), and parity (p = 0.098) were not significantly correlated with the concentration of milk oligosaccharides. The concentrations of 2'-fucosyllactose (2'-FL), lacto-N-neotetraose (LNnT), sialyllacto-N-tetraose c (LSTc), lacto-N-fucopentaose I (LNFP-I), disialylated lacto-N-tetraose (DSLNT), difucosyl-para-lacto-N-neohexaose (DFpLNnH), difucosyl-lacto-N-hexaose (DFLNH[a]), and 3-sialyllactose (3'-SL) showed a gradual downward trend, while the concentration of 3-fucosyllactose (3-FL) showed a gradual upward trend among three lactation stages (p < 0.05). CONCLUSIONS: The concentration of HMOs changes throughout lactation, and it varies between different HMOs. HMO concentrations differed between lactation stage, maternal secretor gene status, Lewis blood type, volume of breast milk expressed, and the province the mother came from. Prematurity, mode of delivery, parity, infants' gender, and maternal characteristics did not affect the HMO concentration. Geographical region may be not associated with HMOs concentration in human milk. There may be a mechanism for co-regulation of the secretion of some of the oligosaccharides such as 2'FL vs. 3FL, 2'FL vs. LNnT, and lacto-N-tetraose (LNT).
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Lactação , Leite Humano , Oligossacarídeos , Feminino , Humanos , Lactente , Gravidez , China , Estudos Transversais , População do Leste Asiático , Leite Humano/química , Oligossacarídeos/análiseRESUMO
Spindle cell lipoma is a rare histological variant of lipoma accounting for 1.5% of adipocytes tumors. It is composed of an admixture of mature adipocytes and fibroblast-like spindle cells in a myxoid stroma. Retroperitoneal atypical spindle cell lipomatous tumor are extremely rare only a single report in the literature reported. Herein we describe a case of a giant lipomatous tumor that was causing partial bowel obstruction. Successful excision with en block resection of the tumor, distal ureter and posterior wall of the bladder was achieved by teamwork between gastrointestinal surgeons and Urologist. The bladder defect was repaired, and left ureteric reimplantation was done. The patient made a good recovery with excellent progress. He has resumed his normal activities as a farmer.
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UK National Health Service (NHS) Clinical Virology Departments provide a repertoire of tests on clinical samples to detect the presence of viral genomic material or host immune responses to viral infection. In December 2019, a novel coronavirus (SARS-CoV-2) emerged which quickly developed into a global pandemic; NHS laboratories responded rapidly to upscale their testing capabilities. To date, there is little information on the impact of increased SARS-CoV-2 screening on non-SARS-CoV-2 testing within NHS laboratories. This report details the virology test requests received by the Leicester-based NHS Virology laboratory from January 2018 to May 2022. Data show that in spite of a dramatic increase in screening, along with multiple logistic and staffing issues, the Leicester Virology Department was mostly able to maintain the same level of service for non-respiratory virus testing while meeting the new increase in SARS-CoV-2 testing.
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COVID-19 , Pandemias , Humanos , SARS-CoV-2 , Medicina Estatal , Teste para COVID-19 , Laboratórios , Técnicas de Laboratório Clínico , COVID-19/diagnóstico , COVID-19/epidemiologia , Reino Unido/epidemiologiaRESUMO
BACKGROUND: Muscle disuse from bed rest or spaceflight results in losses in muscle mass, strength and oxidative capacity. Capillary rarefaction may contribute to muscle atrophy and the reduction in oxidative capacity during bed rest. Artificial gravity may attenuate the negative effects of long-term space missions or bed rest. The aim of the present study was to assess (1) the effects of bed rest on muscle fibre size, fibre type composition, capillarization and oxidative capacity in the vastus lateralis and soleus muscles after 6 and 55 days of bed rest and (2) the effectiveness of artificial gravity in mitigating bed-rest-induced detriments to these parameters. METHODS: Nineteen participants were assigned to a control group (control, n = 6) or an intervention group undergoing 30 min of centrifugation (n = 13). All underwent 55 days of head-down tilt bed rest. Vastus lateralis and soleus biopsies were taken at baseline and after 6 and 55 days of bed rest. Fibre type composition, fibre cross-sectional area, capillarization indices and oxidative capacity were determined. RESULTS: After just 6 days of bed rest, fibre atrophy (-23.2 ± 12.4%, P < 0.001) and reductions in capillary-to-fibre ratio (C:F; 1.97 ± 0.57 vs. 1.56 ± 0.41, P < 0.001) were proportional in both muscles as reflected by a maintained capillary density. Fibre atrophy proceeded at a much slower rate between 6 and 55 days of bed rest (-11.6 ± 12.1% of 6 days, P = 0.032) and was accompanied by a 19.1% reduction in succinate dehydrogenase stain optical density (P < 0.001), without any further significant decrements in C:F (1.56 ± 0.41 vs. 1.49 ± 0.37, P = 0.459). Consequently, after 55 days of bed rest, the capillary supply-oxidative capacity ratio of a fibre had increased by 41.9% (P < 0.001), indicating a capillarization in relative excess of oxidative capacity. Even though the heterogeneity of capillary spacing (LogR SD) was increased after 55 days by 12.7% (P = 0.004), tissue oxygenation at maximal oxygen consumption of the fibres was improved after 55 days bed rest. Daily centrifugation failed to blunt the bed-rest-induced reductions in fibre size and oxidative capacity and capillary rarefaction. CONCLUSIONS: The relationship between fibre size and oxidative capacity with the capillary supply of a fibre is uncoupled during prolonged bed rest as reflected by a rapid loss of muscle mass and capillaries, followed at later stages by a more than proportional loss of mitochondria without further capillary loss. The resulting excessive capillary supply of the muscle after prolonged bed rest is advantageous for the delivery of substrates needed for subsequent muscle recovery.
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Rarefação Microvascular , Humanos , Rarefação Microvascular/patologia , Repouso em Cama/efeitos adversos , Atrofia Muscular/etiologia , Atrofia Muscular/patologia , Músculo Esquelético/patologia , Fibras Musculares Esqueléticas/patologiaRESUMO
Yield decline associated with poor crop establishment, stunting, wilting, and diminished root systems was reported in processing tomato crops in Victoria, Australia. During surveys between 2016 and 2018 Pythium species were isolated by soil baiting and by culturing from the diseased roots and collars of plants exhibiting these symptoms. Eleven species of Pythium were identified based on cultural characteristics and phylogenetic analysis with ITS, Cox-1, and Cox-2 gene sequences. None of the 11 Pythium species had been reported previously from processing or fresh tomatoes in Australia. Pythium dissotocum was the most abundant and widespread species isolated during surveys in each of two growing seasons. In pathogenicity tests, these Pythium species ranged from nonpathogenic to highly aggressive. P. aphanidermatum, P. ultimum, and P. irregulare were consistently the most aggressive species, causing serious damage or death at the pregermination, postgermination, and later stages of plant growth. Five processing tomato cultivars varied significantly in their susceptibility to Pythium disease. These results suggest that Pythium species could be contributing to yield loss in processing tomatoes in Victoria both in the crop establishment phase and through the season.
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Pythium , Solanum lycopersicum , Filogenia , Doenças das Plantas , Pythium/genética , Vitória , VirulênciaRESUMO
We propose a novel method for enforcing AI fairness with respect to protected or sensitive factors. This method uses a dual strategy performing training and representation alteration (TARA) for the mitigation of prominent causes of AI bias. It includes the use of representation learning alteration via adversarial independence to suppress the bias-inducing dependence of the data representation from protected factors and training set alteration via intelligent augmentation to address bias-causing data imbalance by using generative models that allow the fine control of sensitive factors related to underrepresented populations via domain adaptation and latent space manipulation. When testing our methods on image analytics, experiments demonstrate that TARA significantly or fully debiases baseline models while outperforming competing debiasing methods that have the same amount of information-for example, with (% overall accuracy, % accuracy gap) = (78.8, 0.5) versus the baseline method's score of (71.8, 10.5) for Eye-PACS, and (73.7, 11.8) versus (69.1, 21.7) for CelebA. Furthermore, recognizing certain limitations in current metrics used for assessing debiasing performance, we propose novel conjunctive debiasing metrics. Our experiments also demonstrate the ability of these novel metrics in assessing the Pareto efficiency of the proposed methods.
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Generalização Psicológica , Processamento de Imagem Assistida por Computador , Inteligência Artificial , Processamento de Imagem Assistida por Computador/métodosRESUMO
BACKGROUND: The early identification of factors that increase risk of poor recovery from acute low back pain (LBP) is critical to prevent the transition to chronicity. Although most studies of risk factors for poor outcome in LBP tend to investigate the condition once it is already persistent, there is evidence to suggest that this differs from risk factors measured during the early-acute stage. This study aimed to identify early risk factors for poor outcome in the short- and long-term in individuals with acute LBP, and to compare this with factors identified at 3 months in the same cohort. METHODS: One hundred and thirty-three individuals were recruited within 2 weeks of an acute LBP episode and completed questionnaires related to their sociodemographic, psychological, clinical and history/treatment status at baseline and 3 months later, and their pain-level fortnightly for 12 months. RESULTS: Of the 133 participants recruited, follow-up data were provided by 120 at 3 months, 97 at 6 months, 85 at 9 months and 94 at 12 months. Linear regression identified various factors at baseline (acute phase) and 3 months later that predicted short- and long-term outcome (pain level, change in pain). Key findings were that: (1) depressive symptoms at baseline most consistently predicted worse outcome; (2) psychological factors in general at 3 months were more predictive of outcome than when measured at baseline; (3) early health care utilization predicted better outcome, whereas use of pain medication later (3 months) predicted worse outcome; and (4) sex and BMI predicted outcome inconsistently over 12-months. CONCLUSIONS: The results highlight the multidimensional nature of risk factors for poor outcome in LBP and the need to consider time variation in these factors. Significance This study attempts to consider the impact of time variation of candidate risk factors on long-term outcome from the very early onset of acute low back pain. Risk factors across domains (sociodemographic, psychological, clinical, history/treatment) were identified, but their relationship with outcome often depended on when (acute phase vs. 3 months later) they were measured after back pain onset. Findings highlight the need to consider both a diverse range of factors and their potential time variance when assessing risk of poor outcome.
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Dor Aguda , Dor Lombar , Estudos de Coortes , Humanos , Dor Lombar/diagnóstico , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
IMPORTANCE: Anomaly detectors could be pursued for retinal diagnoses based on artificial intelligence systems that may not have access to training examples for all retinal diseases in all phenotypic presentations. Possible applications could include screening of population for any retinal disease rather than a specific disease such as diabetic retinopathy, detection of novel retinal diseases or novel presentations of common retinal diseases, and detection of rare diseases with little or no data available for training. OBJECTIVE: To study the application of anomaly detection to retinal diseases. DESIGN, SETTING, AND PARTICIPANTS: High-resolution retinal images from the publicly available EyePACS data set with fundus images with a corresponding label ranging from 0 to 4 for representing different severities of diabetic retinopathy. Sixteen variants of anomaly detectors were designed. For evaluation, a surrogate problem was constructed, using diabetic retinopathy images, in which only retinas with nonreferable diabetic retinopathy, ie, no diabetic macular edema, and no diabetic retinopathy or mild to moderate nonproliferative diabetic retinopathy were used for training an artificial intelligence system, but both nonreferable and referable diabetic retinopathy (including diabetic macular edema or proliferative diabetic retinopathy) were used to test the system for detecting retinal disease. MAIN OUTCOMES AND MEASURES: Anomaly detectors were evaluated by commonly accepted performance metrics, including area under the receiver operating characteristic curve, F1 score, and accuracy. RESULTS: A total of 88â¯692 high-resolution retinal images of 44â¯346 individuals with varying severity of diabetic retinopathy were analyzed. The best performing across all anomaly detectors had an area under the receiver operating characteristic of 0.808 (95% CI, 0.789-0.827) and was obtained using an embedding method that involved a self-supervised network. CONCLUSIONS AND RELEVANCE: This study suggests when abnormal (diseased) data, ie, referable diabetic retinopathy in this study, were not available for training of retinal diagnostic systems wherein only nonreferable diabetic retinopathy was used for training, anomaly detection techniques were useful in identifying images with and without referable diabetic retinopathy. This suggests that anomaly detectors may be used to detect retinal diseases in more generalized settings and potentially could play a role in screening of populations for retinal diseases or identifying novel diseases and phenotyping or detecting unusual presentations of common retinal diseases.
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Aprendizado Profundo , Retinopatia Diabética , Edema Macular , Inteligência Artificial , Retinopatia Diabética/diagnóstico , Fundo de Olho , HumanosRESUMO
While concurrent training is regularly used in older populations, the inverse relationship between fibre size and oxidative capacity suggests that endurance training in resistance-trained individuals may result in some loss of resistance training-induced gains in muscle mass, which may be more pronounced in older people. We investigated the impact of superimposed endurance training in younger (28.5 ± 4.8 years; n = 8) and older (67.5 ± 5.5 years; n = 7) highly resistance-trained men. Participants underwent a 10-week endurance cycling training programme consisting of five 6-min intervals at 75% max heart rate (HRmax) separated by 4-min intervals at 90% HRmax. The anatomical cross-sectional area (ACSA) of the thigh muscles, as determined with MRI, was 24% smaller in older compared to younger participants (p < 0.001). Although maximal oxygen consumption (VO2max) was also lower in the older group (p < 0.001), VO2max per kg body mass did not differ significantly between younger and older participants. Histological analyses of biopsies of the m. vastus lateralis showed that endurance training induced an increase in succinate dehydrogenase activity in both younger and older participants (p ≤ 0.043), and an increase in the number of capillaries around type I fibres (p = 0.017). The superimposed endurance training did not induce a significant decrease in thigh ACSA, fibre cross-sectional area, or knee extensor maximum voluntary isometric force. These observations indicate that adding endurance training to resistance training can lead to positive endurance-related adaptations without negative consequences for muscle size and strength in older and younger resistance-trained people.
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Treino Aeróbico , Perna (Membro)/fisiologia , Músculo Esquelético/metabolismo , Consumo de Oxigênio/fisiologia , Adaptação Fisiológica/fisiologia , Adulto , Idoso , Humanos , Perna (Membro)/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Músculo Esquelético/diagnóstico por imagem , Treinamento ResistidoRESUMO
We investigate the use of parameterized families of information-theoretic measures to generalize the loss functions of generative adversarial networks (GANs) with the objective of improving performance. A new generator loss function, least kth-order GAN (LkGAN), is introduced, generalizing the least squares GANs (LSGANs) by using a kth-order absolute error distortion measure with k≥1 (which recovers the LSGAN loss function when k=2). It is shown that minimizing this generalized loss function under an (unconstrained) optimal discriminator is equivalent to minimizing the kth-order Pearson-Vajda divergence. Another novel GAN generator loss function is next proposed in terms of Rényi cross-entropy functionals with order α>0, α≠1. It is demonstrated that this Rényi-centric generalized loss function, which provably reduces to the original GAN loss function as αâ1, preserves the equilibrium point satisfied by the original GAN based on the Jensen-Rényi divergence, a natural extension of the Jensen-Shannon divergence. Experimental results indicate that the proposed loss functions, applied to the MNIST and CelebA data sets, under both DCGAN and StyleGAN architectures, confer performance benefits by virtue of the extra degrees of freedom provided by the parameters k and α, respectively. More specifically, experiments show improvements with regard to the quality of the generated images as measured by the Fréchet inception distance score and training stability. While it was applied to GANs in this study, the proposed approach is generic and can be used in other applications of information theory to deep learning, for example, the issues of fairness or privacy in artificial intelligence.
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During the "first wave" of the coronavirus disease 2019 (COVID-19) pandemic in the United Kingdom (March-June 2020), the city of Leicester was particularly hard hit, resulting in reimposed lockdown measures. Although initial polymerase chain reaction testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was attempted within the community, testing was soon abandoned due to an inability to keep up with demand by local laboratories. It is therefore feasible that undiagnosed transmission of COVID-19 in the community by asymptomatic individuals was a real possibility. Therefore, retrospective SARS-CoV-2 immunoglobulin G (IgG) testing of archived sera from out-patients visiting University Hospitals of Leicester NHS Trust service was performed to investigate the transmission of SARS-CoV-2 in the community. A total of 1779 sera samples were tested from samples collected between 16th March and 3rd June 2020, of which 202 (11.35%) were SARS-CoV-2 IgG positive. Positivity was lowest in March (2.54%) at the beginning of the pandemic before peaking in April (17.16%) before a decline in May and June (11.16% and 12.68%, respectively). This retrospective screening offers some insight into the early patterns of SARS-CoV-2 transmission within a sampled community population during the first wave of the COVID-19 pandemic; supporting the argument for more community screening during high incidences of pandemics.
Assuntos
Anticorpos Antivirais/sangue , COVID-19/diagnóstico , COVID-19/epidemiologia , Imunoglobulina G/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Testes Imunológicos , Lactente , Recém-Nascido , Masculino , Programas de Rastreamento/estatística & dados numéricos , Pessoa de Meia-Idade , Pandemias , Estudos Retrospectivos , Reino Unido/epidemiologia , Adulto JovemRESUMO
BACKGROUND: The internet is used for information related to health conditions, including low back pain (LBP), but most LBP websites provide inaccurate information. Few studies have investigated the effectiveness of internet resources in changing health literacy or treatment choices. OBJECTIVE: This study aims to evaluate the effectiveness of the MyBackPain website compared with unguided internet use on health literacy, choice of treatments, and clinical outcomes in people with LBP. METHODS: This was a pragmatic, web-based, participant- and assessor-blinded randomized trial of individuals with LBP stratified by duration. Participants were randomly allocated to have access to the evidence-based MyBackPain website, which was designed with input from consumers and expert consensus or unguided internet use. The coprimary outcomes were two dimensions of the Health Literacy Questionnaire (dimension 2: "having sufficient information to manage my health;" dimension 3: "actively managing my health;" converted to scores 1-100) at 3 months. Secondary outcomes included additional Health Literacy Questionnaire dimensions, quality of treatment choices, and clinical outcomes. RESULTS: A total of 453 participants were recruited, and 321 (70.9%) completed the primary outcomes. Access to MyBackPain was not superior to unguided internet use on primary outcomes (dimension 2: mean difference -0.87 units, 95% CI -3.56 to 1.82; dimension 3: mean difference -0.41 units, 95% CI -2.78 to 1.96). Between-group differences in other secondary outcomes had inconsistent directions and were unlikely to be clinically important, although a small improvement of unclear importance in the quality of stated treatment choices at 1 month was found (mean difference 0.93 units, 95% CI 0.03 to 1.84). CONCLUSIONS: MyBackPain was not superior to unguided internet use for health literacy, but data suggest some short-term improvement in treatment choices. Future research should investigate if greater interactivity and engagement with the website may enhance its impact. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12617001292369; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372926. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2018-027516.