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Oxygen Delignification of Wheat Straw Soda Pulp with Anthraquinone Addition

Zhulan Liu, Yunfeng Cao, Hua Yao, Siqi Wu
2013 BioResources  
Oxygen delignification of wheat straw soda pulp with the addition of anthraquinone (AQ) was conducted to evaluate the effects of AQ on pulp quality. The pulp yield, kappa number, intrinsic viscosity, and brightness were selected as the properties to optimize oxygen delignification. The optimal pulp was obtained via grey relational analysis with an alkali charge of 3%, oxygen pressure of 0.5 MPa at 120 °C for 85 min, and with 0.05% AQ. In contrast to conventional oxygen delignification, the
more » ... ion of AQ produced pulp with a higher yield, and it did not generate other negative impacts on pulp kappa number, viscosity, and brightness. The reaction mechanism of AQ in oxygen delignification was different from that in alkali pulping.
doi:10.15376/biores.8.1.1306-1319 fatcat:d7b2ld7vvrce5potwubm5qz3hq

Fourier Ptychographic Microscopy via Alternating Direction Method of Multipliers

Aiye Wang, Zhuoqun Zhang, Siqi Wang, An Pan, Caiwen Ma, Baoli Yao
2022 Cells  
Fourier ptychographic microscopy (FPM) has risen as a promising computational imaging technique that breaks the trade-off between high resolution and large field of view (FOV). Its reconstruction is normally formulated as a blind phase retrieval problem, where both the object and probe have to be recovered from phaseless measured data. However, the stability and reconstruction quality may dramatically deteriorate in the presence of noise interference. Herein, we utilized the concept of
more » ... ng direction method of multipliers (ADMM) to solve this problem (termed ADMM-FPM) by breaking it into multiple subproblems, each of which may be easier to deal with. We compared its performance against existing algorithms in both simulated and practical FPM platform. It is found that ADMM-FPM method belongs to a global optimization algorithm with a high degree of parallelism and thus results in a more stable and robust phase recovery under noisy conditions. We anticipate that ADMM will rekindle interest in FPM as more modifications and innovations are implemented in the future.
doi:10.3390/cells11091512 pmid:35563818 pmcid:PMC9104836 fatcat:kzsxgrwvtfb6zoq4o7kzwezipi

Evaluation of temperature vegetation dryness index on drought monitoring over Eurasia

Siqi Shi, Fengmei Yao, Jiahua Zhang, Shanshan Yang
2020 IEEE Access  
doi:10.1109/access.2020.2972271 fatcat:vf6fv4s3jbge7je5ouevnwldta

Clinical Features of Acute Rhabdomyolysis in 55 Pediatric Patients

Zhengxiong Yao, Ping Yuan, Siqi Hong, Mei Li, Li Jiang
2020 Frontiers in Pediatrics  
Copyright © 2020 Yao, Yuan, Hong, Li and Jiang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).  ... 
doi:10.3389/fped.2020.00539 pmid:33014933 pmcid:PMC7500160 fatcat:4ryrgruiyrc3nanljsql5eomyq

Cancer stem-like cells directly participate in vasculogenic mimicry channels in triple-negative breast cancer

Sun Huizhi, Yao Nan, Cheng Siqi, Li Linqi, Liu Shiqi, Yang Zhao, Shang Guanjie, Zhang Danfang, Yao Zhi
2019 Cancer Biology and Medicine  
Vasculogenic mimicry (VM) channels that are lined by tumor cells are a functional blood supply in malignant tumors. However, the role of VM-initiating cells remains poorly understood. Cancer stem-like cells (CSCs) are positively correlated with VM. In this study, triple-negative breast cancer (TNBC) enriched with CSCs was used to investigate the relationship between VM and CSCs. The expression of several CSC markers was detected by immunohistochemistry in 100 human breast cancer samples. The
more » ... nical significance of CSC markers and the relationship between VM, CSCs, breast cancer subtypes, and VM-associated proteins were analyzed. CD133+ and ALDH+ human and mouse TNBC cells were isolated by FACS to examine the ability of VM formation and the spatial relationship between VM and CSCs. CSCs were associated with TNBC subtype and VM in human invasive breast cancer. CSCs in TNBC MDA-MB-231 cells formed more VM channels and expressed more molecules promoting VM than the non-TNBC MCF-7 cells in vitro. MDA-MB-231 cells that encircled VM channels on Matrigel expressed CD133. Moreover, CSCs were located near VM channels in the 3D reconstructed blood supply system in human TNBC grafts. The CD133+ and ALDH+ cells isolated from TA2 mouse breast cancer formed more VM channels in vivo. CSCs line VM channels directly. Additionally, CSCs provide more VM-related molecules to synergize VM formation. The signaling pathways that control CSC differentiation may also be potential treatment targets for TNBC.
doi:10.20892/j.issn.2095-3941.2018.0209 pmid:31516750 pmcid:PMC6713644 fatcat:kdgy3pmrhvfknb4ivsqg353vhq

Anti-angiogenic treatment promotes triple-negative breast cancer invasion via vasculogenic mimicry

Huizhi Sun, Danfang Zhang, Zhi Yao, Xian Lin, Jiameng Liu, Qiang Gu, Xueyi Dong, Fang Liu, Yi Wang, Nan Yao, Siqi Cheng, Linqi Li (+1 others)
2017 Cancer Biology & Therapy  
Agents that target angiogenesis have shown limited efficacy for human triple-negative breast cancer (TNBC) in clinical trials. Along with endothelium-dependent vessels, there is also vasculogenic mimicry (VM) in the microcirculation of malignant tumors. The role of VM is not completely understood regarding anti-angiogenic treatment. In this study, human TNBC MDA-MB-231 and Hs578T and non-TNBC MCF-7 and BT474 tumor-bearing mice were treated with sunitinib, an anti-angiogenic drug, using a
more » ... lly relevant schedule. The drug was administered for one week and then discontinued. Tumor growth and invasion were observed, and the microcirculation patterns were detected with PAS/endomucin staining. Moreover, hypoxia and VM-associated proteins were evaluated with Hypoxyprobe kits and immunohistochemistry, respectively. Sunitinib significantly inhibited tumor growth in the TNBC and non-TNBC tumors. However, MDA-MB-231 and Hs578T tumors regrew and were more aggressive when the treatment was stopped. The discontinuation had no significant effect on the behavior of the non-TNBC MCF-7 and BT474 tumors. The growth of endothelium-dependent vessels in the TNBC MDA-MB-231 and Hs578T tumors were blocked by sunitinib, during which the number of VM channels significantly increased and resulted in a rebound of endothelium-dependent vessels after sunitinib discontinuation. Moreover, the VM-associated proteins VE-cadherin and Twist1 upregulated in the sunitinib-treated MDA-MB-231 and Hs578T tumors. Furthermore, the clinical significance of this upregulation was validated in 174 human breast cancers. The results from human breast cancer specimens indicated that there were more VM-positive TNBC cases than those in non-TNBC cases. HIF-1a, MMP2, VE-cadherin, and Twist1 were also expressed in a higher level in human TNBC compared with non-TNBC. In aconclusion, sunitinib promoted TNBC invasion by VM. The VM status could be helpful to predict the efficacy of anti-angiogenic therapy in patients with TNBC.
doi:10.1080/15384047.2017.1294288 pmid:28278077 pmcid:PMC5450737 fatcat:3jdifrkxqfcy5ds6lggss6pava

Competition of natural convection and thermal creep in a square enclosure

Jun Zhang, Siqi Yao, Fei Fei, Mohammad Ghalambaz, Dongsheng Wen
2020 Physics of Fluids  
Although natural convection and thermal creep have been well recognized in the continuum and rarefied regimes, respectively, the study of the competition of them in the whole flow regime, especially in the slip and transitional regimes, is very scarce. From a theoretical point of view, natural convection can be described by Navier-Stokes-Fourier (NSF) equations at the macroscopic level, while thermal creep is based on kinetic theory at the molecular level. Therefore, it is quite challenging to
more » ... apture these two effects simultaneously. In this work, we employ the unified stochastic particle Bhatnagar-Gross-Krook (USP-BGK) method, which was developed by the authors lately [J. Comput. Phys., 400, 108972 (2020) ], to investigate thermally driven gas flow in a square enclosure. The simulation results obtained by the USP-BGK method are validated by comparing to those from NSF solutions and direct simulation Monte Carlo (DSMC) method for the continuum and transitional regimes, respectively. Through massive simulations in a wide range of computational parameters, we find that the flow patterns in the whole flow regime cannot be determined by just one nondimensional parameter, i.e., the Rayleigh number ( Ra ), but needs two nondimensional parameters, i.e., the Knudsen number ( Kn ) and the Froude number ( Fr ), or Kn and Ra . Specifically, small Knudsen and Froude numbers tend to generate natural convection with one vortex in the enclosure, while large Knudsen and Froude numbers tend to cause thermal creep with two vortices arrayed vertically. Moreover, our simulation results and analyses demonstrate that when 0.12 Kn  , thermal creep is dominant if 1.0 Ra  , while natural convection is dominant if 0.28 Ra Fr  . These findings provide useful guidance for better understanding of the complex gas flow resulting from the competition of natural convection and thermal creep under microscale or low-density conditions such as on the Mars.
doi:10.1063/5.0022260 fatcat:3t6jzwmhsffyxc4zwjjnnkxaeu

An enriched granger causal model allowing variable static anatomical constraints

Kun Bi, Guoping Luo, Shui Tian, Siqi Zhang, Xiaoxue Liu, Qiang Wang, Qing Lu, Zhijian Yao
2018 NeuroImage: Clinical  
The anatomical connectivity constrains but does not fully determine functional connectivity, especially when one explores into the dynamics over the course of a trial. Therefore, an enriched granger causal model (GCM) integrated with anatomical prior information is proposed in this study, to describe the dynamic effective connectivity to distinguish the depression and explore the pathogenesis of depression. In the proposed frame, the anatomical information was converted via an optimized
more » ... mation model, which was then integrated into the normal GCM by variational bayesian model. Magnetoencephalography (MEG) signals and diffusion tensor imaging (DTI) of 24 depressive patients and 24 matched controls were utilized for performance comparison. Together with the sliding windowed MEG signals under sad facial stimuli, the enriched GCM was applied to calculate the regional-pair dynamic effective connectivity, which were repeatedly sifted via feature selection and fed into different classifiers. From the aspects of model errors and recognition accuracy rates, results supported the superiority of the enriched GCM with anatomical priors over the normal GCM. For the effective connectivity with anatomical priors, the best subject discrimination accuracy of SVM was 85.42% (the sensitivity was 87.50% and the specificity was 83.33%). Furthermore, discriminative feature analysis suggested that the enriched GCM that detect the variable anatomical constraint on function could better detect more stringent and less dynamic brain function in depression. The proposed approach is valuable in dynamic functional dysfunction exploration in depression and could be useful for depression recognition.
doi:10.1016/j.nicl.2018.11.002 pmid:30448217 pmcid:PMC6411584 fatcat:h2a3kgv2mrgvjlabph5ftdkrqa

Aberrant Temporal-spatial Patterns to Sad expressions in Major Depressive Disorders via Hidden Markov Model [article]

Zhongpeng Dai, Siqi Zhang, Hongliang Zhou, Xinyi Wang, Huan Wang, Zhijian Yao, Qing Lu
2021 bioRxiv   pre-print
., 2019; Jing-Lun, Yao, & Xie, 2007) . Each video was presented lasting for 3 seconds. Then a fixation cross picture was also displayed during the rest.  ... 
doi:10.1101/2021.03.07.433735 fatcat:h5vbjdk3jrhmhna57d2fhejahe

Performance Analysis and Optimization of Power Density Enhanced PMSM with Magnetic Stripe on Rotor

Wenlong Wei, Jinping Zhang, Jin Yao, Siqi Tang, Shiyou Zhang
2020 Energies  
A permanent magnet synchronous motor (PMSM) has advantages in applications such as electric vehicles and all-electric-aircraft because of its inherent characteristics of high power density. In order to further improve its power density, this paper proposes a novel rotor structure with a magnetic stripe, based on the "dual stator + Halbach array" topology of the PMSM, which leads to a PMSM with greater power density. Then, this paper proposes characteristic parameters such as the external air
more » ... proportional coefficient K1 and the internal air gap proportional coefficient K2 of the novel rotor structure, and establishes the torque analysis model of the novel rotor structure and the corresponding motor. Simulation results show that the novel rotor structure can increase the average torque. Then, this paper establishes an optimization model, in which K1 and K2 are taken as optimization variables, a torque fluctuation of no more than 5% is set as a constraint, and the maximum average torque is set as the optimization goal. The results show that the optimized novel rotor structure with magnetic stripe can significantly improve the torque performance of the PMSM, and the optimization method proposed is efficient.
doi:10.3390/en13174457 fatcat:yfnphr47mrf6fpxqtry6w62gdm

Liver Tumor Segmentation based on Multi-scale Candidate Generation and Fractal Residual Network

Zhiqi Bai, Huiyan Jiang, Siqi Li, Yu-dong Yao
2019 IEEE Access  
Liver cancer is one of the most common cancers. Liver tumor segmentation is one of the most important steps in treating liver cancer. Accurate tumor segmentation on computed tomography (CT) images is a challenging task due to the variation of the tumor's shape, size, and location. To this end, this paper proposes a liver tumor segmentation method on CT volumes using multi-scale candidate generation method (MCG), 3D fractal residual network (3D FRN), and active contour model (ACM) in a
more » ... fine manner. First, livers are segmented using 3D U-Net and then MCG is performed on these liver regions for obtaining tumor candidates (all superpixel blocks). Second, 3D FRN is proposed to further determine tumor regions, which is considered as coarse segmentation results. Finally, the ACM is used for tumor segmentation refinement. The proposed 3D MCG-FRN + ACM is trained using the 110 cases in the LiTS dataset and evaluated on a public liver tumor dataset of the 3DIRCADb with dice per case of 0.67. The experimentations and comparisons demonstrate the performance advantage of the 3D MCG-FRN + ACM compared to other segmentation methods. INDEX TERMS Fractal residual network, multi-scale candidate generation method, active contour model, liver tumor segmentation, CT volume.
doi:10.1109/access.2019.2923218 fatcat:ugxhljbxszcavcf4iexehbdaju

An iterative network partition algorithm for accurate identification of dense network modules

Siqi Sun, Xinran Dong, Yao Fu, Weidong Tian
2011 Nucleic Acids Research  
A key step in network analysis is to partition a complex network into dense modules. Currently, modularity is one of the most popular benefit functions used to partition network modules. However, recent studies suggested that it has an inherent limitation in detecting dense network modules. In this study, we observed that despite the limitation, modularity has the advantage of preserving the primary network structure of the undetected modules. Thus, we have developed a simple iterative Network
more » ... artition (iNP) algorithm to partition a network. The iNP algorithm provides a general framework in which any modularity-based algorithm can be implemented in the network partition step. Here, we tested iNP with three modularity-based algorithms: multi-step greedy (MSG), spectral clustering and Qcut. Compared with the original three methods, iNP achieved a significant improvement in the quality of network partition in a benchmark study with simulated networks, identified more modules with significantly better enrichment of functionally related genes in both yeast protein complex network and breast cancer gene co-expression network, and discovered more cancer-specific modules in the cancer gene co-expression network. As such, iNP should have a broad application as a general method to assist in the analysis of biological networks.
doi:10.1093/nar/gkr1103 pmid:22121225 pmcid:PMC3273790 fatcat:4rfeg2qrlncphojis2voifdpoa

Study on the effect of digital economy on high-quality economic development in China

Wei Zhang, Siqi Zhao, Xiaoyu Wan, Yuan Yao, László Vasa
2021 PLoS ONE  
Methodology: Yuan Yao.  ...  (DOCX) Author Contributions Conceptualization: Siqi Zhao. changes in China's interprovincial digital economic development index and in its three sub-indices from 2015 to 2019 are shown in Fig 1.  ... 
doi:10.1371/journal.pone.0257365 pmid:34547019 pmcid:PMC8454970 fatcat:oaqptc5f4vbrznj52xujokksj4

The thalamic functional gradient and its relationship to structural basis and cognitive relevance

Siqi Yang, Yao Meng, Jiao Li, Bing Li, Yun-Shuang Fan, Huafu Chen, Wei Liao
2020 NeuroImage  
The human thalamus is an integrative hub richly connected with cortical networks, involving diverse cognitive functions. Emerging evidence suggests that multiscale structural and functional gradients integrate various information across modalities into an abstract representation. However, the presence of functional gradients in the thalamus and its relationship to structural properties and cognitive functions remain unknown. We estimated the functional gradients of the thalamus in two
more » ... t normal cohorts using a novel diffusion embedding analysis. We identified two main axes of the functional connectivity patterns, and examined associations with thalamic anatomy, morphology, intrinsic geometry, and specific behavioral relevance. We found that the dominant gradient indicated a lateral/medial axis across the thalamus and captured associations with anatomical nuclei and gray matter volume. The second gradient was an anterior/posterior axis and provided a behavioral characterization from lower level perception to higher level cognition. Furthermore, these two gradients strongly correlated with spatial distance, indicating the prominence of intrinsic geometry in functional hierarchies. These findings were replicated in an independent dataset. Overall, our findings suggested that macroscale gradients showed a coordination of structural and functional interactions, with hierarchical organization contributing to behavior characterization.
doi:10.1016/j.neuroimage.2020.116960 pmid:32454205 fatcat:okwb44erznhalmu44x5nrv6upu

Reactivation of Frozen Stored Microalgal-Bacterial Granular Sludge under Aeration and Non-Aeration Conditions

Yao Shen, Lin Zhu, Bin Ji, Siqi Fan, Yabin Xiao, Yingqun Ma
2021 Water  
In this paper, reactivation of microalgal-bacterial granular sludge (MBGS) stored at −20 °C for 6 months was investigated under respective aeration (R1) and non-aeration (R2) conditions. Results showed that the granular activity could be fully recovered within 21 days. The average removal efficiency of ammonia was higher in R1 (92.78%), while R2 showed higher average removal efficiencies of organics (84.97%) and phosphorus (85.28%). It was also found that eukaryotic microalgae growth was
more » ... ted under aeration conditions, whereas prokaryotic microalgae growth and extracellular protein secretion were favored under non-aeration conditions. Sequencing results showed that the microbial community underwent subversive evolution, with Chlorophyta and Proteobacteria being dominant species under both conditions. Consequently, it was reasonable to conclude that the activity and structure of frozen stored MBGS could be recovered under both aeration and non-aeration conditions, of which aeration-free activation was more feasible on account of its energy-saving property. This study provides important information for the storage and transportation of MBGS in wastewater treatment.
doi:10.3390/w13141974 fatcat:7kicivahmfbt5ho3ddfuqxes6y
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