| 1. |
- Yu, Wenjin, et al.
(författare)
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Deep Learning-Based Classification of Cancer Cell in Leptomeningeal Metastasis on Cytomorphologic Features of Cerebrospinal Fluid
- 2022
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 12, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is a critical challenge to diagnose leptomeningeal metastasis (LM), given its technical difficulty and the lack of typical symptoms. The existing gold standard of diagnosing LM is to use positive cerebrospinal fluid (CSF) cytology, which consumes significantly more time to classify cells under a microscope.Objective: This study aims to establish a deep learning model to classify cancer cells in CSF, thus facilitating doctors to achieve an accurate and fast diagnosis of LM in an early stage.Method: The cerebrospinal fluid laboratory of Xijing Hospital provides 53,255 cells from 90 LM patients in the research. We used two deep convolutional neural networks (CNN) models to classify cells in the CSF. A five-way cell classification model (CNN1) consists of lymphocytes, monocytes, neutrophils, erythrocytes, and cancer cells. A four-way cancer cell classification model (CNN2) consists of lung cancer cells, gastric cancer cells, breast cancer cells, and pancreatic cancer cells. Here, the CNN models were constructed by Resnet-inception-V2. We evaluated the performance of the proposed models on two external datasets and compared them with the results from 42 doctors of various levels of experience in the human-machine tests. Furthermore, we develop a computer-aided diagnosis (CAD) software to generate cytology diagnosis reports in the research rapidly.Results: With respect to the validation set, the mean average precision (mAP) of CNN1 is over 95% and that of CNN2 is close to 80%. Hence, the proposed deep learning model effectively classifies cells in CSF to facilitate the screening of cancer cells. In the human-machine tests, the accuracy of CNN1 is similar to the results from experts, with higher accuracy than doctors in other levels. Moreover, the overall accuracy of CNN2 is 10% higher than that of experts, with a time consumption of only one-third of that consumed by an expert. Using the CAD software saves 90% working time of cytologists.Conclusion: A deep learning method has been developed to assist the LM diagnosis with high accuracy and low time consumption effectively. Thanks to labeled data and step-by-step training, our proposed method can successfully classify cancer cells in the CSF to assist LM diagnosis early. In addition, this unique research can predict cancer’s primary source of LM, which relies on cytomorphologic features without immunohistochemistry. Our results show that deep learning can be widely used in medical images to classify cerebrospinal fluid cells. For complex cancer classification tasks, the accuracy of the proposed method is significantly higher than that of specialist doctors, and its performance is better than that of junior doctors and interns. The application of CNNs and CAD software may ultimately aid in expediting the diagnosis and overcoming the shortage of experienced cytologists, thereby facilitating earlier treatment and improving the prognosis of LM.
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| 2. |
- Albuhayri, Mohammed, et al.
(författare)
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Asymptotics of Implied Volatility in the Gatheral Double Stochastic Volatility Model
- 2019
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Ingår i: Proceedings of 18th Applied Stochastic Models and Data Analysis International Conference with the Demographics 2019 Workshop, Florence, Italy: 11-14 June, 2019. - : ISAST: International Society for the Advancement of Science and Technology. - 9786185180331 ; , s. 81-90
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Konferensbidrag (refereegranskat)abstract
- The double-mean-reverting model by Gatheral [1] is motivated by empirical dynamics of the variance of the stock price. No closed-form solution for European option exists in the above model. We study the behaviour of the implied volatility with respect to the logarithmic strike price and maturity near expiry and at-the- money. Using the method by Pagliarani and Pascucci [6], we calculate explicitly the first few terms of the asymptotic expansion of the implied volatility within a parabolic region.
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| 3. |
- Albuhayri, Mohammed, et al.
(författare)
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Asymptotics of Implied Volatility in the Gatheral Double Stochastic Volatility Model
- 2021
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Ingår i: Applied Modeling Techniques and Data Analysis 2. - Hoboken, NJ, USA : John Wiley & Sons. - 9781786306746 ; , s. 27-38
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Bokkapitel (refereegranskat)abstract
- The double-mean-reverting model by Gatheral is motivated by empirical dynamics of the variance of the stock price. No closed-form solution for European option exists in the above model. We study the behaviour of the implied volatility with respect to the logarithmic strike price and maturity near expiry and at-the-money. Using the method by Pagliarani and Pascucci, we calculate explicitly the first few terms of the asymptotic expansion of the implied volatility within a parabolic region.
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| 4. |
- Bijnens, Johan, et al.
(författare)
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Hilbert series and higher-order Lagrangians for the O(N) model
- 2023
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2023:5
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Tidskriftsartikel (refereegranskat)abstract
- We compare the Hilbert series approach with explicit constructions of higher-order Lagrangians for the O(N) nonlinear sigma model. We use the Hilbert series to find the number and type of operators up to mass dimension 16, for spacetime dimension D up to 12 and N up to 12, and further classify the operators into spacetime parity and parity of the internal symmetry group O(N). The explicit construction of operators is done up to mass dimension 12 for both parities even and dimension 10 for the other three cases. The results of the two methods are in full agreement. This provides evidence for the Hilbert series conjecture regarding co-closed but not co-exact k-forms, which takes into account the integration-by-parts relations.
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| 5. |
- Cao, Cejun, et al.
(författare)
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Two-phase COVID-19 medical waste transport optimisation considering sustainability and infection probability
- 2023
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Ingår i: Journal of Cleaner Production. - : ELSEVIER SCI LTD. - 0959-6526 .- 1879-1786. ; 389
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Tidskriftsartikel (refereegranskat)abstract
- A safe and effective medical waste transport network is beneficial to control the COVID-19 pandemic and at least decelerate the spread of novel coronavirus. Seldom studies concentrated on a two-phase COVID-19 medical waste transport in the presence of multi-type vehicle selection, sustainability, and infection probability, which is the focus of this paper. This paper aims to identify the priority of sustainable objectives and observe the impacts of multi-phase and infection probability on the results. Thus, such a problem is formulated as a mixed-integer programming model to minimise total potential infection risks, minimise total environmental risks, and maximise total economic benefits. Then, a hybrid solution strategy is designed, incorporating a lexicographic optimisation approach and a linear weighted sum method. A real-world case study from Chongqing is used to illustrate this methodology. Results indicate that the solution strategy guides a good COVID-19 medical waste transport scheme within 1 min. The priority of sustainable objectives is society, economy, and environment in the first and second phases because the total Gap of case No.35 is 3.20%. A decentralised decision mode is preferred to design a COVID-19 medical waste transport network at the province level. Whatever the infection probability is, infection risk is the most critical concern in the COVID-19 medical waste clean-up activities. Environmental and economic sustainability performance also should be considered when infection probability is more than a certain threshold.
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| 6. |
- Kong, Jiahui, et al.
(författare)
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Tetra- and Octapyrroles Synthesized from Confusion and Fusion Approaches
- 2016
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Ingår i: Organic Letters. - : American Chemical Society (ACS). - 1523-7060 .- 1523-7052. ; 18:19, s. 5046-5049
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Tidskriftsartikel (refereegranskat)abstract
- By oxidation of an alternately N-confused bilane in CH2Cl2, a C-N fused tetrapyrrin was synthesized that bears a 5.5.5-tricyclic ring generated from an intramolecular C-N linkage. When CH3CN was used as the reaction medium, a multiply C-N-fused octapyrrolic dimer was also obtained that contained two 5.5.5.7.5-pentacyclic moieties and a bipyrrole unit generated from the intramolecular C-N linkage and intermolecular C-C linkage, respectively. This could be coordinated with Ni(acac)(2) to afford a mixed-ligand complex.
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| 7. |
- Li, Jiahui, et al.
(författare)
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Extra low friction coefficient caused by the formation of a solid-like layer : A new lubrication mechanism found through molecular simulation of the lubrication of MoS2 nanoslits
- 2018
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Ingår i: Chinese Journal of Chemical Engineering. - : Elsevier. - 1004-9541 .- 2210-321X. ; 26:12, s. 2412-2419
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Tidskriftsartikel (refereegranskat)abstract
- Monolayer molybdenum disulfide (MoS2) is a novel two-dimensional material that exhibits potential application in lubrication technology. In this work, molecular dynamics was used to investigate the lubrication behaviour of different polar fluid molecules (i.e., water, methanol and decane) confined in monolayer MoS2 nanoslits. The pore width effect (i.e., 1.2, 1.6 and 2.0 nm) was also evaluated. Results revealed that decane molecules exhibited good lubricating performance compared to the other two kinds of molecules. The friction coefficient followed the order of decane < methanol < water, and decreased evidently as the slit width increased, except for decane. Analysis of the spatial distribution and mobility of different confined fluid molecules showed that a solid-like layer was formed near the slit wall. This phenomenon led to the extra low friction coefficient of confined decane molecules
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| 8. |
- Liu, Jiahui, et al.
(författare)
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Highly Porous Metalloporphyrin Covalent Ionic Frameworks with Well-Defined Cooperative Functional Groups as Excellent Catalysts for CO2 Cycloaddition
- 2019
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Ingår i: Chemistry - A European Journal. - : WILEY-V C H VERLAG GMBH. - 0947-6539 .- 1521-3765. ; 25:38, s. 9052-9059
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Tidskriftsartikel (refereegranskat)abstract
- The development of multifunctional heterogeneous catalysts with high porosity and remarkable catalytic activity still remains a challenge. Herein, four highly porous metalloporphyrin covalent ionic frameworks (CIFs) were synthesized by coupling 5,10,15,20-tetrakis(4-nitrophenyl)porphyrin (TNPP) with 3,8-diamino-6-phenylphenanithridine (NPPN) or 5,5 '-diamino-2,2 '-bipyridine (NBPy) followed by ionization with bromoethane (C2H5Br) or dibromoethane (C2H4Br2) and then metalization with Zn or Co. The resulting CIFs showed high efficiency in catalyzing the cycloaddition of propylene oxide (PO) with CO2 to form propylene carbonate (PC). All of the Zn-containing CIF catalysts were able to catalyze the cycloaddition reaction with a PC yield greater than 97 %. The TNPP/NBPy (CIF2) catalyst ionized with C2H4Br2 and metalized with Zn (Zn-CIF2-C2H4) exhibited the highest catalytic activity among the synthesized catalysts. The high catalytic performance of Zn-CIF2-C2H4 is related to its high porosity (577 m(2) g(-1)), high Br:metal ratio (1:3.89), and excellent synergistic action between the Lewis acidic Zn sites and the nucleophilic Br- ions. Zn-CIF2-C2H4 is sufficiently stable that greater than 94 % PC yield could be obtained even after six cycles. In addition, Zn-CIF2-C2H4 could catalyze the cycloaddition of several other epoxides with CO2. These highly porous materials are promising multifunctional and efficient catalysts for industrially relevant reactions.
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| 9. |
- Liu, Weihua, et al.
(författare)
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Effects of smart agricultural production investment announcements on shareholder value : Evidence from China
- 2022
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Ingår i: Journal of Management Science and Engineering. - China : KeAi Publishing Communications Ltd.. - 2096-2320. ; 7:3, s. 387-404
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Tidskriftsartikel (refereegranskat)abstract
- The advent of the era of the smart economy has made agricultural production more intelligent. An increasing number of companies have launched a series of investment activities aimed at smart agricultural production (SAP). However, whether smart agricultural production investment (SAPI) impacts the stock market has yet to be confirmed. Therefore, based on the sample data of 118 listed companies in China from 2010 to 2019, this study empirically examines the impact of SAPI announcements on shareholder value, as indicated by abnormal returns of stocks. Further, we tested the moderating effect of certain characteristic factors on abnormal stock returns. The research results illustrate a significant positive connection between SAPI announcements and shareholder value. Moreover, considering the announcement content and company factors, this study investigates the impacts of different investment targets and industries on the market reaction to SAPI announcements. We find that non-agricultural companies have a more positive market reaction to SAPI than agricultural companies; the higher the liability-asset ratio, the more positive will be the stock market reaction to SAPI.
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| 10. |
- Shu, Jiahui, et al.
(författare)
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Efficient synthesis of polyether polyols in simple microreactors
- 2021
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Ingår i: Reaction Chemistry & Engineering. - : Royal Society of Chemistry. - 2058-9883. ; 6:4, s. 685-693
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Tidskriftsartikel (refereegranskat)abstract
- Polyether polyols as a crucial chemical for the synthesis of polyurethanes have attracted much attention, especially for propylene oxide-based polyether polyols due to their ready availability and good structural diversity. In the present work, microreactors configured with a SIMM-V2 micromixer and stainless steel capillary were developed for the continuous and efficient synthesis of propylene oxide-based polyether polyols. For the conversion of propylene oxide higher than 95%, the reaction time was less than 60 s that was significantly shorter than that in a batch reactor. Also, the reaction temperature can be controlled precisely, thereby obtaining high purity polyether polyol products. To identify the maximum performance of the microreactors, while keeping the conversion of PO higher than 95%, the novel process windows of the reactors were determined by investigating the relations of reaction temperature and pressure, reaction temperature and residence time, and feed flow rate and residence time. The results showed that high quality polyether polyols could be easily prepared in the microreactors under flexible operating conditions. In addition, polyether polyols with higher molecular weights could also be prepared by using a two SIMM-V2 configured microreactor. This work showed that the microreactors are promising candidates for the synthesis of polyether polyols in the industry.
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