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BACKGROUND AND AIMS: The impact of various categories of information on the prediction of post-ERCP pancreatitis (PEP) remains uncertain. We comprehensively investigated the risk factors associated with PEP by constructing and validating a model incorporating multimodal data through multiple steps. METHODS: Cases (n = 1916) of ERCP were retrospectively collected from multiple centers for model construction. Through literature research, 49 electronic health record (EHR) features and 1 image feature related to PEP were identified. The EHR features were categorized into baseline, diagnosis, technique, and prevention strategies, covering pre-ERCP, intra-ERCP, and peri-ERCP phases. We first incrementally constructed models 1 to 4 incorporating these 4 feature categories and then added the image feature into models 1 to 4 and developed models 5 to 8. All models underwent testing and comparison using both internal and external test sets. Once the optimal model was selected, we conducted comparisons among multiple machine learning algorithms. RESULTS: Compared with model 2 that incorporated baseline and diagnosis features, adding technique and prevention strategies (model 4) greatly improved the sensitivity (63.89% vs 83.33%, P < .05) and specificity (75.00% vs 85.92%, P < .001). A similar tendency was observed in the internal and external tests. In model 4, the top 3 features ranked by weight were previous pancreatitis, nonsteroidal anti-inflammatory drug use, and difficult cannulation. The image-based feature has the highest weight in models 5 to 8. Finally, model 8 used a random forest algorithm and showed the best performance. CONCLUSIONS: We first developed a multimodal prediction model for identifying PEP with a clinical-acceptable performance. The image and technique features are crucial for PEP prediction.
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Colangiopancreatografia Retrógrada Endoscópica , Aprendizado de Máquina , Pancreatite , Humanos , Pancreatite/etiologia , Pancreatite/prevenção & controle , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Colangiopancreatografia Retrógrada Endoscópica/métodos , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Fatores de Risco , Registros Eletrônicos de Saúde , AlgoritmosRESUMO
BACKGROUND AND AIM: Early whitish gastric neoplasms can be easily misdiagnosed; differential diagnosis of gastric whitish lesions remains a challenge. We aim to build a deep learning (DL) model to diagnose whitish gastric neoplasms and explore the effect of adding domain knowledge in model construction. METHODS: We collected 4558 images from two institutions to train and test models. We first developed two sole DL models (1 and 2) using supervised and semi-supervised algorithms. Then we selected diagnosis-related features through literature research and developed feature-extraction models to determine features including boundary, surface, roundness, depression, and location. Then predictions of the five feature-extraction models and sole DL model were combined and inputted into seven machine-learning (ML) based fitting-diagnosis models. The optimal model was selected as ENDOANGEL-WD (whitish-diagnosis) and compared with endoscopists. RESULTS: Sole DL 2 had higher sensitivity (83.12% vs 68.67%, Bonferroni adjusted P = 0.024) than sole DL 1. Adding domain knowledge, the decision tree performed best among the seven ML models, achieving higher specificity than DL 1 (84.38% vs 72.27%, Bonferroni adjusted P < 0.05) and higher accuracy than DL 2 (80.47%, Bonferroni adjusted P < 0.001) and was selected as ENDOANGEL-WD. ENDOANGEL-WD showed better accuracy compared with 10 endoscopists (75.70%, P < 0.001). CONCLUSIONS: We developed a novel system ENDOANGEL-WD combining domain knowledge and traditional DL to detect gastric whitish neoplasms. Adding domain knowledge improved the performance of traditional DL, which provided a novel solution for establishing diagnostic models for other rare diseases potentially.
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Aprendizado Profundo , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico , Estudos Retrospectivos , Diagnóstico Diferencial , Sensibilidade e Especificidade , AlgoritmosRESUMO
BACKGROUND: A computer-assisted (CAD) system was developed to assess, score, and classify the technical difficulty of common bile duct (CBD) stone removal during endoscopic retrograde cholangiopancreatography (ERCP). The efficacy of the CADâsystem was subsequently assessed through a multicenter, prospective, observational study. METHOD: All patients who met the inclusion criteria were included. Based on cholangiogram images, the CAD system analyzed the level of difficulty of stone removal and classified it into "difficult" and "easy" groups. Subsequently, differences in clinical endpoints, including attempts at stone extraction, stone extraction time, total operation time, and stone clearance rates were compared between the two groups. RESULTS: 173 patients with CBD stones from three hospitals were included in the study. The group classified as difficult by CADâhad more extraction attempts (7.20 vs. 4.20, Pâ<â0.001), more frequent machine lithotripsy (30.4â% vs. 7.1â%, Pâ<â0.001), longer stone extraction time (16.59 vs. 7.69 minutes, Pâ<â0.001), lower single-session stone clearance rate (73.9â% vs. 94.5â%, Pâ<â0.001), and lower total stone clearance rate (89.1â% vs. 97.6â%, Pâ=â0.019) compared with the group classified as easy by CAD. CONCLUSION: The CAD system effectively assessed and classified the degree of technical difficulty in endoscopic stone extraction during ERCP. In addition, it automatically provided a quantitative evaluation of CBD and stones, which in turn could help endoscopists to apply suitable procedures and interventional methods to minimize the possible risks associated with endoscopic stone removal.
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Colangiopancreatografia Retrógrada Endoscópica , Cálculos Biliares , Humanos , Colangiopancreatografia Retrógrada Endoscópica/métodos , Inteligência Artificial , Resultado do Tratamento , Cálculos Biliares/diagnóstico por imagem , Cálculos Biliares/cirurgia , Esfinterotomia Endoscópica/métodosRESUMO
OBJECTIVES: Accurate endoscopic optical prediction of the depth of cancer invasion is critical for guiding an optimal treatment approach of large sessile colorectal polyps but was hindered by insufficient endoscopists expertise and inter-observer variability. We aimed to construct a clinically applicable artificial intelligence (AI) system for the identification of presence of cancer invasion in large sessile colorectal polyps. METHODS: A deep learning-based colorectal cancer invasion calculation (CCIC) system was constructed. Multi-modal data including clinical information, white light (WL) and image-enhanced endoscopy (IEE) were included for training. The system was trained using 339 lesions and tested on 198 lesions across three hospitals. Man-machine contest, reader study and video validation were further conducted to evaluate the performance of CCIC. RESULTS: The overall accuracy of CCIC system using image and video validation was 90.4% and 89.7%, respectively. In comparison with 14 endoscopists, the accuracy of CCIC was comparable with expert endoscopists but superior to all the participating senior and junior endoscopists in both image and video validation set. With CCIC augmentation, the average accuracy of junior endoscopists improved significantly from 75.4% to 85.3% (P = 0.002). CONCLUSIONS: This deep learning-based CCIC system may play an important role in predicting the depth of cancer invasion in colorectal polyps, thus determining treatment strategies for these large sessile colorectal polyps.
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Pólipos do Colo , Neoplasias Colorretais , Humanos , Pólipos do Colo/cirurgia , Pólipos do Colo/patologia , Inteligência Artificial , Colonoscopia/métodos , Endoscopia Gastrointestinal , Neoplasias Colorretais/patologiaRESUMO
BACKGROUND AND AIMS: The optical diagnosis of colorectal cancer (CRC) invasion depth with white light (WL) and image-enhanced endoscopy (IEE) remains challenging. We aimed to construct and validate a 2-modal deep learning-based system, incorporated with both WL and IEE images (named Endo-CRC) in estimating the invasion depth of CRC. METHODS: Samples were retrospectively obtained from 3 hospitals in China. We combined WL and IEE images into image pairs. Altogether, 337,278 image pairs from 268 noninvasive and superficial CRC and 181,934 image pairs from 82 deep CRC were used for training. A total of 296,644 and 4528 image pairs were used for internal and external tests and for comparison with endoscopists. Thirty-five videos were used for evaluating the real-time performance of the Endo-CRC system. Two deep learning models, solely using either WL (model W) or IEE images (model I), were constructed to compare with Endo-CRC. RESULTS: The accuracies of Endo-CRC in internal image tests with and without advanced CRC were 91.61% and 93.78%, respectively, and 88.65% in the external test, which did not include advanced CRC. In an endoscopist-machine competition, Endo-CRC achieved an expert comparable accuracy of 88.11% and the highest sensitivity compared with all endoscopists. In a video test, Endo-CRC achieved an accuracy of 100.00%. Compared with model W and model I, Endo-CRC had a higher accuracy (per image pair: 91.61% vs 88.27% compared with model I and 91.61% vs 81.32% compared with model W). CONCLUSIONS: The Endo-CRC system has great potential for assisting in CRC invasion depth diagnosis and may be well applied in clinical practice.
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Neoplasias Colorretais , Aprendizado Profundo , Neoplasias Colorretais/diagnóstico por imagem , Endoscopia Gastrointestinal , Humanos , Imagem de Banda Estreita , Estudos RetrospectivosRESUMO
BACKGROUND: Tandem colonoscopy studies have found that about one in five adenomas are missed at colonoscopy. It remains debatable whether the combination of a computer-aided polyp detection (CADe) system with a computer-aided quality improvement (CAQ) system for real-time monitoring of withdrawal speed results in additional benefits in adenoma detection or if the synergetic effect may be harmed due to excessive visual burden resulting from information overload. This study aimed to evaluate the interaction effect on improving the adenoma detection rate (ADR). METHODS: This single-center, randomized, four-group, parallel, controlled study was performed at Renmin Hospital of Wuhan University. Between 1 July and 15 October 2020, 1076 patients were randomly allocated into four treatment groups: control 271, CADe 268, CAQ 269, and CADe plus CAQ (COMBO) 268.âThe primary outcome was ADR. RESULTS: The ADR in the control, CADe, CAQ, and COMBO groups was 14.76â% (95â% confidence interval [CI] 10.54 to 18.98), 21.27â% (95â%CI 16.37 to 26.17), 24.54â% (95â%CI 19.39 to 29.68), and 30.60â% (95â%CI 25.08 to 36.11), respectively. The ADR was higher in the COMBO group compared with the CADe group (21.27â% vs. 30.6â%, Pâ=â0.024, odds ratio [OR] 1.284, 95â%CI 1.033 to 1.596) but not compared with the CAQ group (24.54â% vs. 30.6â%, Pâ=â0.213, OR 1.309, 95â%CI 0.857 to 2.000, respectively). CONCLUSIONS: CAQ significantly improved the efficacy of CADe in a four-group, parallel, controlled study. No significant difference in the ADR or polyp detection rate was found between CAQ and COMBO.
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Adenoma , Pólipos do Colo , Neoplasias Colorretais , Adenoma/diagnóstico por imagem , Inteligência Artificial , Pólipos do Colo/diagnóstico por imagem , Colonoscopia/métodos , Neoplasias Colorretais/diagnóstico por imagem , Humanos , Melhoria de QualidadeRESUMO
BACKGROUND : Accurate identification of the differentiation status and margins for early gastric cancer (EGC) is critical for determining the surgical strategy and achieving curative resection in EGC patients. The aim of this study was to develop a real-time system to accurately identify differentiation status and delineate the margins of EGC on magnifying narrow-band imaging (ME-NBI) endoscopy. METHODS : 2217 images from 145 EGC patients and 1870 images from 139 EGC patients were retrospectively collected to train and test the first convolutional neural network (CNN1) to identify EGC differentiation status. The performance of CNN1 was then compared with that of experts using 882 images from 58 EGC patients. Finally, 928 images from 132 EGC patients and 742 images from 87 EGC patients were used to train and test CNN2 to delineate the EGC margins. RESULTS : The system correctly predicted the differentiation status of EGCs with an accuracy of 83.3â% (95â% confidence interval [CI] 81.5â%â-â84.9â%) in the testing dataset. In the manâ-âmachine contest, CNN1 performed significantly better than the five experts (86.2â%, 95â%CI 75.1â%â-â92.8â% vs. 69.7â%, 95â%CI 64.1â%â-â74.7â%). For delineating EGC margins, the system achieved an accuracy of 82.7â% (95â%CI 78.6â%â-â86.1â%) in differentiated EGC and 88.1â% (95â%CI 84.2â%â-â91.1â%) in undifferentiated EGC under an overlap ratio of 0.80.âIn unprocessed EGC videos, the system achieved real-time diagnosis of EGC differentiation status and EGC margin delineation in ME-NBI endoscopy. CONCLUSION : We developed a deep learning-based system to accurately identify differentiation status and delineate the margins of EGC in ME-NBI endoscopy. This system achieved superior performance when compared with experts and was successfully tested in real EGC videos.
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Aprendizado Profundo , Neoplasias Gástricas , Gastroscopia , Humanos , Imagem de Banda Estreita , Estudos Retrospectivos , Neoplasias Gástricas/diagnóstico por imagemRESUMO
PURPOSE: Poor oral health appears to be a risk factor for pancreatic cancer, possibly implicating the oral microbiota. In this pilot study, we evaluated the characteristics of the oral microbiota in patients with pancreatic ductal adenocarcinoma (PDAC), intraductal papillary mucinous neoplasms (IPMN), and healthy controls. METHODS: Forty newly diagnosed PDAC patients, 39 IPMN patients, and 58 controls, excluding current smokers and users of antibiotics, provided saliva samples. Common oral bacterial species were comprehensively surveyed by sequencing of the 16S rRNA microbial genes. We obtained measures of diversity and the mean relative proportions of individual taxa. We explored the degree to which these measures differed according to respondent characteristics based on individual interviews. RESULTS: PDAC cases did not differ in diversity measures from either controls or IPMN cases. PDAC cases had higher mean relative proportions of Firmicutes and related taxa, while controls had higher mean relative proportions of Proteobacteria and related taxa. Results were generally similar when comparing PDAC to IPMN cases. Among IPMNs and controls combined, younger individuals had higher levels of several taxa within the Proteobacteria. The only other variable consistently related to mean relative proportions was mouthwash use, with taxa within Firmicutes more common among users. CONCLUSIONS: While there were no differences in diversity of the oral microbiota among these groups, there were differences in the mean relative proportions of some taxa. Characteristics of the oral microbiota are not associated with most measures of oral health.
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Bactérias/isolamento & purificação , Carcinoma Ductal Pancreático/microbiologia , Microbiota , Boca/microbiologia , Neoplasias Pancreáticas/microbiologia , Idoso , Bactérias/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , RNA Ribossômico 16S/genéticaRESUMO
AIM: To report our experience with retroperitoneal laparoendoscopic single-site (LESS) ureterolithotomy for the management of large proximal ureteral stones. PATIENTS AND METHODS: From July 2011 to April 2012, 20 patients underwent retroperitoneal LESS ureterolithotomy. The indications for the operation were impacted upper ureteral stones larger than 15 mm. A reusable elastic single-port device with 3 working channels was inserted through the 2.5-cm incision at the midpoint between the costal arch and iliac crest on the mid-axillary line. A rigid 10-mm 30° extra-long laparoscope was introduced for monitoring, and a combination of lengthened pre-bent and conventional laparoscopic instruments was used for handling. The surgical procedure was similar to conventional retroperitoneal laparoscopic ureterolithotomy. RESULTS: Retroperitoneal LESS ureterolithotomy was completed in all of the patients. The mean stone size was 18.8 mm (range 16-28). The mean operative time was 108 min (range 75-140). Significant bleeding was not observed, and no major intraoperative complications occurred in any of the patients. The mean hospital stay was 4.4 days (range 3-7). CONCLUSIONS: Retroperitoneal LESS ureterolithotomy, using a reusable elastic single-port device, is technically feasible and safe, and the combination of conventional and pre-bent laparoscopic instruments represents an attractive option for retroperitoneal LESS.
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Laparoscopia/métodos , Cálculos Ureterais/cirurgia , Procedimentos Cirúrgicos Urológicos/métodos , Adulto , Perda Sanguínea Cirúrgica , Desenho de Equipamento , Estudos de Viabilidade , Feminino , Humanos , Laparoscópios , Laparoscopia/efeitos adversos , Laparoscopia/instrumentação , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Cálculos Ureterais/diagnóstico , Procedimentos Cirúrgicos Urológicos/efeitos adversos , Procedimentos Cirúrgicos Urológicos/instrumentação , Adulto JovemRESUMO
The development of cryogenic semiconductor electronics and superconducting quantum computing requires composite materials that can provide both thermal conduction and thermal insulation. We demonstrated that at cryogenic temperatures, the thermal conductivity of graphene composites can be both higher and lower than that of the reference pristine epoxy, depending on the graphene filler loading and temperature. There exists a well-defined cross-over temperature-above it, the thermal conductivity of composites increases with the addition of graphene; below it, the thermal conductivity decreases with the addition of graphene. The counter-intuitive trend was explained by the specificity of heat conduction at low temperatures: graphene fillers can serve as, both, the scattering centers for phonons in the matrix material and as the conduits of heat. We offer a physical model that explains the experimental trends by the increasing effect of the thermal boundary resistance at cryogenic temperatures and the anomalous thermal percolation threshold, which becomes temperature dependent. The obtained results suggest the possibility of using graphene composites for, both, removing the heat and thermally insulating components at cryogenic temperatures-a capability important for quantum computing and cryogenically cooled conventional electronics.
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OBJECTIVES: The histopathologic diagnosis of colorectal sessile serrated lesions (SSLs) and hyperplastic polyps (HPs) is of low consistency among pathologists. This study aimed to develop and validate a deep learning (DL)-based logical anthropomorphic pathology diagnostic system (LA-SSLD) for the differential diagnosis of colorectal SSL and HP. METHODS: The diagnosis framework of the LA-SSLD system was constructed according to the current guidelines and consisted of 4 DL models. Deep convolutional neural network (DCNN) 1 was the mucosal layer segmentation model, DCNN 2 was the muscularis mucosa segmentation model, DCNN 3 was the glandular lumen segmentation model, and DCNN 4 was the glandular lumen classification (aberrant or regular) model. A total of 175 HP and 127 SSL sections were collected from Renmin Hospital of Wuhan University during November 2016 to November 2022. The performance of the LA-SSLD system was compared to 11 pathologists with different qualifications through the human-machine contest. RESULTS: The Dice scores of DCNNs 1, 2, and 3 were 93.66%, 58.38%, and 74.04%, respectively. The accuracy of DCNN 4 was 92.72%. In the human-machine contest, the accuracy, sensitivity, and specificity of the LA-SSLD system were 85.71%, 86.36%, and 85.00%, respectively. In comparison with experts (pathologist D: accuracy 83.33%, sensitivity 90.91%, specificity 75.00%; pathologist E: accuracy 85.71%, sensitivity 90.91%, specificity 80.00%), LA-SSLD achieved expert-level accuracy and outperformed all the senior and junior pathologists. CONCLUSIONS: This study proposed a logical anthropomorphic diagnostic system for the differential diagnosis of colorectal SSL and HP. The diagnostic performance of the system is comparable to that of experts and has the potential to become a powerful diagnostic tool for SSL in the future. It is worth mentioning that a logical anthropomorphic system can achieve expert-level accuracy with fewer samples, providing potential ideas for the development of other artificial intelligence models.
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Pólipos do Colo , Neoplasias Colorretais , Aprendizado Profundo , Humanos , Pólipos do Colo/diagnóstico , Pólipos do Colo/patologia , Inteligência Artificial , Redes Neurais de Computação , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologiaRESUMO
INTRODUCTION: Endoscopic evaluation is crucial for predicting the invasion depth of esophagus squamous cell carcinoma (ESCC) and selecting appropriate treatment strategies. Our study aimed to develop and validate an interpretable artificial intelligence-based invasion depth prediction system (AI-IDPS) for ESCC. METHODS: We reviewed the PubMed for eligible studies and collected potential visual feature indices associated with invasion depth. Multicenter data comprising 5,119 narrow-band imaging magnifying endoscopy images from 581 patients with ESCC were collected from 4 hospitals between April 2016 and November 2021. Thirteen models for feature extraction and 1 model for feature fitting were developed for AI-IDPS. The efficiency of AI-IDPS was evaluated on 196 images and 33 consecutively collected videos and compared with a pure deep learning model and performance of endoscopists. A crossover study and a questionnaire survey were conducted to investigate the system's impact on endoscopists' understanding of the AI predictions. RESULTS: AI-IDPS demonstrated the sensitivity, specificity, and accuracy of 85.7%, 86.3%, and 86.2% in image validation and 87.5%, 84%, and 84.9% in consecutively collected videos, respectively, for differentiating SM2-3 lesions. The pure deep learning model showed significantly lower sensitivity, specificity, and accuracy (83.7%, 52.1% and 60.0%, respectively). The endoscopists had significantly improved accuracy (from 79.7% to 84.9% on average, P = 0.03) and comparable sensitivity (from 37.5% to 55.4% on average, P = 0.27) and specificity (from 93.1% to 94.3% on average, P = 0.75) after AI-IDPS assistance. DISCUSSION: Based on domain knowledge, we developed an interpretable system for predicting ESCC invasion depth. The anthropopathic approach demonstrates the potential to outperform deep learning architecture in practice.
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Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Carcinoma de Células Escamosas do Esôfago/diagnóstico , Carcinoma de Células Escamosas do Esôfago/patologia , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Esofagoscopia/métodos , Inteligência Artificial , Estudos Cross-Over , Sensibilidade e Especificidade , Estudos Multicêntricos como AssuntoRESUMO
White light endoscopy is the most pivotal tool for detecting early gastric neoplasms. Previous artificial intelligence (AI) systems were primarily unexplainable, affecting their clinical credibility and acceptability. We aimed to develop an explainable AI named ENDOANGEL-ED (explainable diagnosis) to solve this problem. A total of 4482 images and 296 videos with focal lesions from 3279 patients from eight hospitals were used for training, validating, and testing ENDOANGEL-ED. A traditional sole deep learning (DL) model was trained using the same dataset. The performance of ENDOANGEL-ED and sole DL was evaluated on six levels: internal and external images, internal and external videos, consecutive videos, and man-machine comparison with 77 endoscopists in videos. Furthermore, a multi-reader, multi-case study was conducted to evaluate the ENDOANGEL-ED's effectiveness. A scale was used to compare the overall acceptance of endoscopists to traditional and explainable AI systems. The ENDOANGEL-ED showed high performance in the image and video tests. In man-machine comparison, the accuracy of ENDOANGEL-ED was significantly higher than that of all endoscopists in internal (81.10% vs. 70.61%, p < 0.001) and external videos (88.24% vs. 78.49%, p < 0.001). With ENDOANGEL-ED's assistance, the accuracy of endoscopists significantly improved (70.61% vs. 79.63%, p < 0.001). Compared with the traditional AI, the explainable AI increased the endoscopists' trust and acceptance (4.42 vs. 3.74, p < 0.001; 4.52 vs. 4.00, p < 0.001). In conclusion, we developed a real-time explainable AI that showed high performance, higher clinical credibility, and acceptance than traditional DL models and greatly improved the diagnostic ability of endoscopists.
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ZrSe3 with a quasi-one-dimensional (quasi-1D) crystal structure belongs to the transition metal trichalcogenides (TMTCs) family. Owing to its unique optical, electrical, and optoelectrical properties, ZrSe3 is promising for applications in field effect transistors, photodetectors, and thermoelectrics. Compared with extensive studies of the above-mentioned physical properties, the thermal properties of ZrSe3 have not been experimentally investigated. Here, we report the crystal growth and thermal and optical properties of ZrSe3. Millimeter-sized single crystalline ZrSe3 flakes were prepared using a chemical vapor transport method. These flakes could be exfoliated into microribbons by liquid-phase exfoliation. The transmission electron microscope studies suggested that the obtained microribbons were single crystals along the chain axis. ZrSe3 exhibited a specific heat of 0.311 J g-1 K-1 at 300 K, close to the calculated value of the Dulong-Petit limit. The fitting of low-temperature specific heat led to a Debye temperature of 110 K and an average sound velocity of 2122 m s-1. The thermal conductivity of a polycrystalline ZrSe3 sample exhibited a maximum value of 10.4 ± 1.9 W m-1 K-1 at 40 K. The thermal conductivity decreased above 40 K and reached a room-temperature value of 5.4 ± 1.3 W m-1 K-1. The Debye model fitting of the solid thermal conductivity agreed well with the experimental data below 200 K but showed a deviation at high temperatures, indicating that optical phonons could substantially contribute to thermal transport at high temperatures. The calculated phonon mean free path decreased with temperatures between 2 and 21 K. The mean free path at 2 K approached 3 µm, which was similar to the grain size of the polycrystalline sample. This work provides useful insights into the preparation and thermal properties of quasi-1D ZrSe3.
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Van der Waals heterostructures offer great versatility to tailor unique interactions at the atomically flat interfaces between dissimilar layered materials and induce novel physical phenomena. By bringing monolayer 1 T' WTe2, a two-dimensional quantum spin Hall insulator, and few-layer Cr2Ge2Te6, an insulating ferromagnet, into close proximity in an heterostructure, we introduce a ferromagnetic order in the former via the interfacial exchange interaction. The ferromagnetism in WTe2 manifests in the anomalous Nernst effect, anomalous Hall effect as well as anisotropic magnetoresistance effect. Using local electrodes, we identify separate transport contributions from the metallic edge and insulating bulk. When driven by an AC current, the second harmonic voltage responses closely resemble the anomalous Nernst responses to AC temperature gradient generated by nonlocal heater, which appear as nonreciprocal signals with respect to the induced magnetization orientation. Our results from different electrodes reveal spin-polarized edge states in the magnetized quantum spin Hall insulator.
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OBJECTIVE: ⢠To report our experience with retroperitoneal laparoscopic dismembered pyeloplasty for pelvi-ureteric junction (PUJ) obstruction in children. PATIENTS AND METHODS: ⢠Between March 2007 and December 2009, 38 children with PUJ obstruction (mean age 8.3 years, range 3-14) underwent retroperitoneal laparoscopic dismembered pyeloplasty. ⢠A ureteric catheter was inserted into the mid-ureter cystoscopically. During pyeloplasty, the proximal end of the ureteric catheter was extracorporeally sutured to the distal end of the JJ stent with silk. ⢠The ureteric catheter was then pulled down and the stent was pulled antegrade into the ureter and bladder. RESULTS: ⢠The approach was retroperitoneal in all patients except one who required open conversion. The overall mean operative time was 162 min (range 145-210 min) and this appeared to decrease with experience. Mean hospital stay was 4 days (range 3-7 days). ⢠Mean follow-up was 20.2 months (range 6-32 months). Satisfactory drainage with decreased hydronephrosis was documented in all patients on ultrasonography and intravenous urography. CONCLUSION: ⢠Our study shows that retroperitoneal laparoscopic dismembered pyeloplasty is a feasible and effective alternative to open pyeloplasty with a relatively minimal complication rate in children 3 years of age and older, but it should be undertaken by experienced laparoscopic surgeons.
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Laparoscopia , Stents , Obstrução Ureteral/cirurgia , Procedimentos Cirúrgicos Urológicos/métodos , Adolescente , Pré-Escolar , Feminino , Humanos , Masculino , Espaço Retroperitoneal , Fatores de Tempo , Resultado do Tratamento , Obstrução Ureteral/fisiopatologia , Procedimentos Cirúrgicos Urológicos/instrumentaçãoRESUMO
Mulching has been extensively sought after in modern agriculture. However, massive utilization of plastics for mulching has induced severe environmental concerns. Developing biodegradable mulch thus represents an emerging need for future agriculture. By using bamboo-derived carboxymethyl cellulose (CMC), this study proposed a crosslinking strategy to prepare liquid film as quality mulch. CMC was synthesized by delignifying bamboo and etherifying resultant cellulose, which was then blended with polyvinyl alcohol (PVA) and crosslinked by glutaraldehyde to prepare a liquid film. By simply spraying on soil, mulch can quickly form on soil surface. Especially, bamboo-timber derived mulch had strong mechanical property (18.2 MPa), good transmittance (74.2%) and moisture absorption (141%), and excellent soil moisture retention. More importantly, about 64% of used mulches were biodegraded within 60-d after burring in soil, which will not need post-handling. These results highlighted that bamboo-derived mulch can be an alternative of current plastic mulch to tackle associated environmental pollution.
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Biodegradação Ambiental , Carboximetilcelulose Sódica/química , Agricultura Orgânica , Sasa/química , Biopolímeros , Fenômenos Químicos , Agricultura Orgânica/métodos , Compostos Fitoquímicos/química , Solo/química , ÁguaRESUMO
Background and Aims: To investigate the impact of the computer-assisted system on esophagogastroduodenoscopy (EGD) training for novice trainees in a prospective randomized controlled trial. Methods: We have constructed a computer-aided system (CAD) using retrospective images based on deep learning which could automatically monitor the 26 anatomical landmarks of the upper digestive tract and document standard photos. Six novice trainees were allocated and grouped into the CAD group and control group. Each of them took the training course, pre and post-test, and EGD examination scored by two experts. The CAD group was trained with the assistance of the CAD system and the control group without. Results: Both groups achieved great improvements in EGD skills. The CAD group received a higher examination grading score in the EGD examination (72.83 ± 16.12 vs. 67.26 ± 15.64, p = 0.039), especially in the mucosa observation (26.40 ± 6.13 vs. 24.11 ± 6.21, p = 0.020) and quality of collected images (7.29 ± 1.09 vs. 6.70 ± 1.05). The CAD showed a lower blind spot rate (2.19 ± 2.28 vs. 3.92 ± 3.30, p = 0.008) compared with the control group. Conclusion: The artificial intelligence assistant system displayed assistant capacity on standard EGD training, and assisted trainees in achieving a learning curve with high operation quality, which has great potential for application. Clinical Trial Registration: This trial is registered at https:/clinicaltrials.gov/, number NCT04682821.
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Computed tomography (CT) is the preferred imaging method for diagnosing 2019 novel coronavirus (COVID19) pneumonia. We aimed to construct a system based on deep learning for detecting COVID-19 pneumonia on high resolution CT. For model development and validation, 46,096 anonymous images from 106 admitted patients, including 51 patients of laboratory confirmed COVID-19 pneumonia and 55 control patients of other diseases in Renmin Hospital of Wuhan University were retrospectively collected. Twenty-seven prospective consecutive patients in Renmin Hospital of Wuhan University were collected to evaluate the efficiency of radiologists against 2019-CoV pneumonia with that of the model. An external test was conducted in Qianjiang Central Hospital to estimate the system's robustness. The model achieved a per-patient accuracy of 95.24% and a per-image accuracy of 98.85% in internal retrospective dataset. For 27 internal prospective patients, the system achieved a comparable performance to that of expert radiologist. In external dataset, it achieved an accuracy of 96%. With the assistance of the model, the reading time of radiologists was greatly decreased by 65%. The deep learning model showed a comparable performance with expert radiologist, and greatly improved the efficiency of radiologists in clinical practice.
Assuntos
Infecções por Coronavirus/complicações , Aprendizado Profundo , Processamento de Imagem Assistida por Computador/métodos , Pneumonia Viral/complicações , Pneumonia/complicações , Pneumonia/diagnóstico por imagem , Razão Sinal-Ruído , Tomografia Computadorizada por Raios X , Adulto , COVID-19 , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Estudos RetrospectivosRESUMO
BACKGROUND: Colonoscopy performance varies among endoscopists, impairing the discovery of colorectal cancers and precursor lesions. We aimed to construct a real-time quality improvement system (ENDOANGEL) to monitor real-time withdrawal speed and colonoscopy withdrawal time and to remind endoscopists of blind spots caused by endoscope slipping. We also aimed to evaluate the effectiveness of this system for improving adenoma yield of everyday colonoscopy. METHODS: The ENDOANGEL system was developed using deep neural networks and perceptual hash algorithms. We recruited consecutive patients aged 18-75 years from Renmin Hospital of Wuhan University in China who provided written informed consent. We randomly assigned patients (1:1) using computer-generated random numbers and block randomisation (block size of four) to either colonoscopy with the ENDOANGEL system or unassisted colonoscopy (control). Endoscopists were not masked to the random assignment but analysts and patients were unaware of random assignments. The primary endpoint was the adenoma detection rate (ADR), which is the proportion of patients having one or more adenomas detected at colonoscopy. The primary analysis was done per protocol (ie, in all patients having colonoscopy done in accordance with the assigned intervention) and by intention to treat (ie, in all randomised patients). This trial is registered with http://www.chictr.org.cn, ChiCTR1900021984. FINDINGS: Between June 18, 2019, and Sept 6, 2019, 704 patients were randomly allocated colonoscopy with the ENDOANGEL system (n=355) or unassisted (control) colonoscopy (n=349). In the intention-to-treat population, ADR was significantly greater in the ENDOANGEL group than in the control group, with 58 (16%) of 355 patients allocated ENDOANGEL-assisted colonoscopy having one or more adenomas detected, compared with 27 (8%) of 349 allocated control colonoscopy (odds ratio [OR] 2·30, 95% CI 1·40-3·77; p=0·0010). In the per-protocol analysis, findings were similar, with 54 (17%) of 324 patients assigned ENDOANGEL-assisted colonoscopy and 26 (8%) of 318 patients assigned control colonoscopy having one or more adenomas detected (OR 2·18, 95% CI 1·31-3·62; p=0·0026). No adverse events were reported. INTERPRETATION: The ENDOANGEL system significantly improved the adenoma yield during colonoscopy and seems to be effective and safe for use during routine colonoscopy. FUNDING: Hubei Provincial Clinical Research Center for Digestive Disease Minimally Invasive Incision, Hubei Province Major Science and Technology Innovation Project, and the National Natural Science Foundation of China.