69 results on '"Ni, Yi"'
Search Results
2. Null-homotopic knots have Property R
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Ni, Yi
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Mathematics - Geometric Topology ,Mathematics::K-Theory and Homology ,General Mathematics ,FOS: Mathematics ,Geometric Topology (math.GT) ,Mathematics::Representation Theory ,Mathematics::Geometric Topology - Abstract
We prove that if $K$ is a nontrivial null-homotopic knot in a closed oriented $3$--manfiold $Y$ such that $Y-K$ does not have an $S^1\times S^2$ summand, then the zero surgery on $K$ does not have an $S^1\times S^2$ summand. This generalizes a result of Hom and Lidman, who proved the case when $Y$ is an irreducible rational homology sphere., 9 pages
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- 2023
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3. The next-to-top term in knot Floer homology
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Ni, Yi
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Mathematics - Geometric Topology ,57K18 ,FOS: Mathematics ,Geometric Topology (math.GT) ,Geometry and Topology ,Mathematical Physics - Abstract
Let $K$ be a null-homologous knot in a generalized L-space $Z$ with $b_1(Z)\le1$. Let $F$ be a Seifert surface of $K$ with genus $g$. We show that if $\widehat{HFK}(Z,K,[F],g)$ is supported in a single $\mathbb Z/2\mathbb Z$--grading, then \[\mathrm{rank}\widehat{HFK}(Z,K,[F],g-1)\ge\mathrm{rank}\widehat{HFK}(Z,K,[F],g).\], Comment: 10 pages
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- 2023
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4. Leukocyte invasion of the brain after peripheral trauma in zebrafish (Danio rerio)
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Xiang-Ke Chen, Joseph Shiu-Kwong Kwan, Gordon Tin-Chun Wong, Zhen-Ni Yi, Alvin Chun-Hang Ma, and Raymond Chuen-Chung Chang
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Inflammation ,Macrophages ,Clinical Biochemistry ,Leukocytes ,Animals ,Brain ,Humans ,Molecular Medicine ,Molecular Biology ,Biochemistry ,Zebrafish - Abstract
Despite well-known systemic immune reactions in peripheral trauma, little is known about their roles in posttraumatic neurological disorders, such as anxiety, sickness, and cognitive impairment. Leukocyte invasion of the brain, a common denominator of systemic inflammation, is involved in neurological disorders that occur in peripheral inflammatory diseases, whereas the influences of peripheral leukocytes on the brain after peripheral trauma remain largely unclear. In this study, we found that leukocytes, largely macrophages, transiently invaded the brain of zebrafish larvae after peripheral trauma through vasculature-independent migration, which was a part of the systemic inflammation and was mediated by interleukin-1b (il1b). Notably, myeloid cells in the brain that consist of microglia and invading macrophages were implicated in posttraumatic anxiety-like behaviors, such as hyperactivity (restlessness) and thigmotaxis (avoidance), while a reduction in systemic inflammation or myeloid cells can rescue these behaviors. In addition, invading leukocytes together with microglia were found to be responsible for the clearance of apoptotic cells in the brain; however, they also removed the nonapoptotic cells, which suggested that phagocytes have dual roles in the brain after peripheral trauma. More importantly, a category of conserved proteins between zebrafish and humans or rodents that has been featured in systemic inflammation and neurological disorders was determined in the zebrafish brain after peripheral trauma, which supported that zebrafish is a translational model of posttraumatic neurological disorders. These findings depicted leukocyte invasion of the brain during systemic inflammation after peripheral trauma and its influences on the brain through il1b-dependent mechanisms.
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- 2022
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5. WaterScenes: A Multi-Task 4D Radar-Camera Fusion Dataset and Benchmark for Autonomous Driving on Water Surfaces
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Yao, Shanliang, Guan, Runwei, Wu, Zhaodong, Ni, Yi, Zhang, Zixian, Huang, Zile, Zhu, Xiaohui, Yue, Yutao, Yue, Yong, Seo, Hyungjoon, and Man, Ka Lok
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FOS: Computer and information sciences ,Computer Science - Robotics ,Computer Vision and Pattern Recognition (cs.CV) ,Computer Science - Computer Vision and Pattern Recognition ,Robotics (cs.RO) - Abstract
Autonomous driving on water surfaces plays an essential role in executing hazardous and time-consuming missions, such as maritime surveillance, survivors rescue, environmental monitoring, hydrography mapping and waste cleaning. This work presents WaterScenes, the first multi-task 4D radar-camera fusion dataset for autonomous driving on water surfaces. Equipped with a 4D radar and a monocular camera, our Unmanned Surface Vehicle (USV) proffers all-weather solutions for discerning object-related information, including color, shape, texture, range, velocity, azimuth, and elevation. Focusing on typical static and dynamic objects on water surfaces, we label the camera images and radar point clouds at pixel-level and point-level, respectively. In addition to basic perception tasks, such as object detection, instance segmentation and semantic segmentation, we also provide annotations for free-space segmentation and waterline segmentation. Leveraging the multi-task and multi-modal data, we conduct numerous experiments on the single modality of radar and camera, as well as the fused modalities. Results demonstrate that 4D radar-camera fusion can considerably enhance the robustness of perception on water surfaces, especially in adverse lighting and weather conditions. WaterScenes dataset is public on https://waterscenes.github.io.
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- 2023
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6. Experience and acceptability for HPV self-sampling among women in Jiangsu province, China: a cross-sectional survey
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Qu, Shui-Xiang, Ni, Yi-Hua, Qin, Jian-Fen, Chen, Xiao-Yan, Wu, Wei-Li, and Zhang, Wei-Chu
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Obstetrics and Gynecology - Abstract
This aim of this study was to investigate women’s knowledge about HPV along with their experience and acceptability of self-sampling in Jiangsu province, China. A total of 862 women aged 25–63 years old from Jiangsu province who purchased an HPV self-sampling test kit were invited to complete a questionnaire designed by the authors. Participants had high acceptability for HPV self-sampling with a mean score of 4.2 (95% [CI], 4.1–4.22) out of 5 points. 27% of participants preferred clinician-sampling, 33% preferred self-sampling, other 40% expressed no preference. Women with good knowledge about HPV and with a good experience with HPV self-sampling were more acceptable for self-sampling (P < 0.05). The biggest concern about HPV self-sampling of the participants includes ‘specimens’ spoilage’, ‘incorrect sampling’, ‘can’t get results in time’, and so on. HPV self-sampling can be used to improve cervical cancer screening coverage and participation rates in China. Cancer screening and can be an alternative primary screening for cervical cancer.•What the results of this study add? This study adds new findings about Chinese women’s experience and acceptability of HPV self-sampling. We found that most women had high acceptability for HPV self-sampling in Jiangsu province, China, and high knowledge about HPV as well as good•What is already known on this subject? HPV self-sampling testing was proven to be useful for improving the uptake rate of cervical experience of self-sampling can improve the acceptability for self-sampling in women.•What the implications are of these findings for clinical practice and/or further research? Further research should assess the acceptability of women with less education or who never screened. Cancer screening and can be an alternative primary screening for cervical cancer. •What the results of this study add? This study adds new findings about Chinese women’s experience and acceptability of HPV self-sampling. We found that most women had high acceptability for HPV self-sampling in Jiangsu province, China, and high knowledge about HPV as well as good •What is already known on this subject? HPV self-sampling testing was proven to be useful for improving the uptake rate of cervical experience of self-sampling can improve the acceptability for self-sampling in women. •What the implications are of these findings for clinical practice and/or further research? Further research should assess the acceptability of women with less education or who never screened.
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- 2023
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7. Modeling leukemia with zebrafish (Danio rerio): Towards precision medicine
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Zhen-Ni Yi, Xiang-Ke Chen, and Alvin Chun-Hang Ma
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Disease Models, Animal ,Leukemia ,Neoplasms ,Animals ,Humans ,Cell Biology ,Precision Medicine ,Zebrafish - Abstract
Leukemia is a type of blood cancer characterized by high genetic heterogeneity and fatality. While chemotherapy remains the primary form of treatment for leukemia, its effectiveness was profoundly diminished by the genetic heterogeneity and cytogenetic abnormalities of leukemic cells. Therefore, there is an unmet need to develop precision medicine for leukemia with distinct genetic backgrounds. Zebrafish (Danio rerio), a freshwater fish with exceptional feasibility in genome editing, is a powerful tool for rapid human cancer modeling. In the past decades, zebrafish have been adopted in modeling human leukemia, exploring the molecular mechanisms of underlying genetic abnormalities, and discovering novel therapeutic agents. Although many recurrent mutations of leukemia have been modeled in zebrafish for pathological study and drug discovery, its great potential in leukemia modeling was not yet fully exploited, particularly in precision medicine. In this review, we evaluated the current zebrafish models of leukemia/pre-leukemia and genetic techniques and discussed the potential of zebrafish models with novel techniques, which may contribute to the development of zebrafish as a disease model for precision medicine in treating leukemia.
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- 2022
8. The prism manifold realization problem II
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Ballinger, William, Ni, Yi, Ochse, Tynan, and Vafaee, Faramarz
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Statistics and Probability ,Mathematics - Geometric Topology ,010308 nuclear & particles physics ,0103 physical sciences ,FOS: Mathematics ,57M25, 57R65 ,Geometric Topology (math.GT) ,Geometry and Topology ,Statistics, Probability and Uncertainty ,01 natural sciences ,Analysis - Abstract
We continue our study of the realization problem for prism manifolds. Every prism manifold can be parametrized by a pair of relatively prime integers $p>1$ and $q$. We determine a complete list of prism manifolds $P(p, q)$ that can be realized by positive integral surgeries on knots in $S^3$ when $q>p$. The methodology undertaken to obtain the classification is similar to that of the case $q, 43 pages, 9 figures, and 3 tables
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- 2021
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9. Floer homology and right-veering monodromy
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Baldwin, John A., Ni, Yi, and Sivek, Steven
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Mathematics - Geometric Topology ,Mathematics - Symplectic Geometry ,Mathematics::Geometric Topology ,Mathematics::Symplectic Geometry - Abstract
We prove that the knot Floer complex of a fibered knot detects whether the monodromy of its fibration is right-veering. In particular, this leads to a purely knot Floer-theoretic characterization of tight contact structures, by the work of Honda, Kazez, and Matic. Our proof makes use of the relationship between the Heegaard Floer homology of mapping tori and the symplectic Floer homology of area-preserving surface diffeomorphisms. We describe applications of this work to Dehn surgeries and taut foliations., Comment: 29 pages, 4 figures
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- 2022
10. Knot Floer homology and fixed points
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Ni, Yi
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Mathematics - Geometric Topology ,Mathematics - Symplectic Geometry ,FOS: Mathematics ,Symplectic Geometry (math.SG) ,Geometric Topology (math.GT) ,Mathematics::Geometric Topology ,Mathematics::Symplectic Geometry - Abstract
If $K$ is a fibered knot in a closed, oriented $3$--manifold $Y$ with fiber $F$, and $\widehat{HFK}(Y,K,[F], g(F)-1;\mathbb Z/2\mathbb Z)$ has rank $r$, then the monodromy of $K$ is freely isotopic to a diffeomorphism with at most $r-1$ fixed points. This generalizes earlier work of Baldwin--Hu--Sivek and Ni. We also clarify a misleading formula in Cotton-Clay's computation of the symplectic Floer homology of mapping classes of surfaces., 9 pages
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- 2022
11. Distinct roles of core autophagy-related genes (ATGs) in zebrafish definitive hematopoiesis
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Xiang-Ke Chen, Zhen-Ni Yi, Jack Jark-Yin Lau, and Alvin Chun-Hang Ma
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Despite the well-described discrepancy between some of the macroautophagy/autophagy-related genes (ATGs) in the regulation of hematopoiesis, the varying essentiality of core ATGs in vertebrate definitive hematopoiesis remains largely unclear. Here, we employed zebrafish (Danio rerio) to compare the function of six core atgs from the core autophagy machineries, which included atg13, beclin1 (becn1), atg9a, atg2a, atg5, and atg3, in vertebrate definitive hematopoiesis via CRISPR-Cas9 ribonucleoprotein targeting. Zebrafish embryos with various atg mutations showed autophagic deficiency throughout the body, including hematopoietic cells. The atgs mutations unsurprisingly caused distinctive hematopoietic abnormalities in zebrafish. Notably, becn1 or atg9a mutation resulted in hematopoietic stem cells (HSCs) expansion during the development of the embryo into a larva, which can be attributed to the proteomic changes in metabolism, HSCs regulators, and apoptosis. Besides, atg3 mutation lowered the leukocytes in developing zebrafish embryos. Intriguingly, a synergistic effect on HSCs expansion was identified in atg13+becn1 and atg9a+atg2a or atg3 double mutations, in which atg13 mutation and atg2a or atg3 mutation exacerbated and mitigated the HSCs expansion in becn1 and atg9a mutations, respectively. In addition, the myeloid cell type-specific effects of various atgs were also determined between neutrophils and macrophages. Of these, a skewed ratio of neutrophils versus macrophages was found in atg13 mutation, while both of them were reduced in atg3 mutation. These findings demonstrated the distinct roles of atgs and their interplays in zebrafish definitive hematopoiesis, thereby suggested that the vertebrate definitive hematopoiesis is regulated in an atgs-dependent manner.
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- 2022
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12. A Survey on Zero Trust Architecture: Challenges and Future Trends
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He, Yuanhang, Huang, Daochao, Chen, Lei, Ni, Yi, and Ma, Xiangjie
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Article Subject - Abstract
The traditional perimeter-based network protection model cannot adapt to the development of current technology. Zero trust is a new type of network security model, which is based on the concept of never trust and always verify. Whether the access subject is in the internal network or the external network, it needs to be authenticated to access resources. The zero trust model has received extensive attention in research and practice because it can meet the new network security requirements. However, the application of zero trust is still in its infancy, and enterprises, organizations, and individuals are not fully aware of the advantages and disadvantages of zero trust, which greatly hinders the application of zero trust. This paper introduces the existing zero trust architecture and analyzes the core technologies including identity authentication, access control, and trust assessment, which are mainly relied on in the zero trust architecture. The main solutions under each technology are compared and analyzed to summarize the advantages and disadvantages, as well as the current challenges and future research trends. Our goal is to provide support for the research and application of future zero trust architectures.
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- 2022
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13. Measurement of Thresholds Using Auditory Steady-State Response and Cochlear Microphonics in Children with Auditory Neuropathy
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Ping Lu, Bin Wang, Yue Huang, Wen Jiang, Wen-xia Chen, Zheng-min Xu, Ni-Yi Hua, and Yan Wang
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Male ,medicine.medical_specialty ,Hearing loss ,Auditory neuropathy ,Audiology ,01 natural sciences ,03 medical and health sciences ,Speech and Hearing ,0302 clinical medicine ,0103 physical sciences ,Microphonics ,medicine ,Humans ,Hearing Loss, Central ,Child ,030223 otorhinolaryngology ,010301 acoustics ,High signal intensity ,business.industry ,Infant ,Auditory Threshold ,Visual reinforcement audiometry ,medicine.disease ,Cochlea ,Child, Preschool ,Normal children ,Evoked Potentials, Auditory ,Female ,medicine.symptom ,business - Abstract
The detection of precise hearing thresholds in infants and children with auditory neuropathy (AN) is challenging with current objective methods, especially in those younger than six months of age.The aim of this study was to compare the thresholds using auditory steady-state response (ASSR) and cochlear microphonics (CM) in children with AN and children with normal hearing.The thresholds of CM, ASSR, and visual reinforcement audiometry (VRA) tests were recorded; the ASSR and VRA frequencies used were 250, 500, 1000, 2000, and 4000 Hz.The participants in this study were 15 children with AN (27 ears) (1–7.6 years, median age 4.1 years) and ten children with normal hearing (20 ears) (1–8 years, median age four years).The thresholds of the three methods were compared, and histograms were used to represent frequency distributions of threshold differences obtained from the three methods.In children with normal hearing, the average CM thresholds (84.5 dB) were significantly higher than the VRA thresholds (10.0–10.8 dB); in children with AN, both CM and VRA responses were seen at high signal levels (88.9 dB and 70.6–103.4 dB, respectively). In normal children, the difference between mean VRA and ASSR thresholds ranged from 17.5 to 30.3 dB, which was significantly smaller than the difference seen between the mean CM and VRA thresholds (71.5–72.3 dB). The correlation between VRA and ASSR in children with normal hearing ranged from 0.38 to 0.48, whereas no such correlation was seen in children with AN at any frequency (0.03–0.19).Our results indicated that ASSR and CM were poor predictors of the conventional behavioral threshold in children with AN.
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- 2019
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14. Interaction of non-parenchymal hepatocytes in the process of hepatic fibrosis
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Cheng, Qi-Ni, Yang, Xue, Wu, Jiang-Feng, Ai, Wen-Bing, and Ni, Yi-Ran
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Liver Cirrhosis ,Kupffer Cells ,Kupffer cell ,Endothelial Cells ,Review ,Lung Injury ,Capillaries ,liver sinusoidal endothelial cell ,hepatic microenvironment ,Liver ,Hepatic Stellate Cells ,Hepatocytes ,intercellular interaction ,Humans ,hepatic stellate cell ,Signal Transduction - Abstract
Hepatic fibrosis (HF) is the process of fibrous scar formation caused by chronic liver injury of different etiologies. Previous studies have hypothesized that the activation of hepatic stellate cells (HSCs) is the central process in HF. The interaction between HSCs and surrounding cells is also crucial. Additionally, hepatic sinusoids capillarization, inflammation, angiogenesis and fibrosis develop during HF. The process involves multiple cell types that are highly connected and work in unison to maintain the homeostasis of the hepatic microenvironment, which serves a key role in the initiation and progression of HF. The current review provides novel insight into the intercellular interaction among liver sinusoidal endothelial cells, HSCs and Kupffer cells, as well as the hepatic microenvironment in the development of HF.
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- 2021
15. Blocking entry of hepatitis B and D viruses to hepatocytes as a novel immunotherapy for treating chronic infections
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Maravelia, Panagiota, Frelin, Lars, Ni, Yi, Caro Pérez, Noelia, Ahlén, Gustaf, Jagya, Neetu, Verch, Georg, Verhoye, Lieven, Pater, Lena, Johansson, Magnus, Pasetto, Anna, Meuleman, Philip, Urban, Stephan, and Sällberg, Matti
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Hepatitis B virus ,PreS1 antibodies ,SURFACE-ANTIGEN ,Hepatitis D, Chronic ,PROTEIN ,Mice, Transgenic ,Mice, SCID ,UPA-SCID MOUSE ,Major Articles and Brief Reports ,Mice ,Hepatitis B, Chronic ,HUMANIZED ANTIBODY ,HUMAN LIVER ,Medicine and Health Sciences ,HBV ,Animals ,Humans ,T-cell tolerance ,AcademicSubjects/MED00860 ,Hepatitis B Vaccines ,chronic hepatitis B ,C VIRUS ,IMMUNE TOLERANCE ,virus diseases ,DNA ,Virus Internalization ,digestive system diseases ,Mice, Inbred C57BL ,AcademicSubjects/MED00290 ,Viruses ,Hepatocytes ,T-CELLS ,Female ,Immunotherapy ,Rabbits ,immunotherapy ,hepatitis D antigen ,Hepatitis Delta Virus - Abstract
Background Chronic hepatitis B and D virus (HBV/HDV) infections can cause cancer. Current HBV therapy using nucleoside analogues (NAs) is life-long and reduces but does not eliminate the risk of cancer. A hallmark of chronic hepatitis B is a dysfunctional HBV-specific T-cell response. We therefore designed an immunotherapy driven by naive healthy T cells specific for the HDV antigen (HDAg) to bypass the need for HBV-specific T cells in order to prime PreS1-specific T cells and PreS1 antibodies blocking HBV entry. Methods Ten combinations of PreS1 and/or HDAg sequences were evaluated for induction of PreS1 antibodies and HBV- and HDV-specific T cells in vitro and in vivo. Neutralization of HBV by PreS1-specific murine and rabbit antibodies was evaluated in cell culture, and rabbit anti-PreS1 were tested for neutralization of HBV in mice repopulated with human hepatocytes. Results The best vaccine candidate induced T cells to PreS1 and HDAg, and PreS1 antibodies blocking HBV entry in vitro. Importantly, adoptive transfer of PreS1 antibodies prevented, or modulated, HBV infection after a subsequent challenge in humanized mice. Conclusions We here describe a novel immunotherapy for chronic HBV/HDV that targets viral entry to complement NAs and coming therapies inhibiting viral maturation., The paper shows a completely new immunotherapy for chronic hepatitis B and potentially also hepatitis D. The immunotherapy induced neutralizing antibodies and T cells targeting both HBV and HDV. Importantly, the induced antibodies neutralized HBV in vitro and in vivo.
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- 2021
16. Is exercise a senolytic medicine? A systematic review
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Gordon Tin Chun Wong, Zhen Ni Yi, Joseph Kwan, Alvin C.H. Ma, Xiang Ke Chen, Kazi Md Mahmudul Hasan, and Raymond Chuen-Chung Chang
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EXPRESSION ,Adult ,0301 basic medicine ,Aging ,Geriatrics & Gerontology ,CLEARANCE ,Adolescent ,PHYSICAL INACTIVITY ,Physiology ,Cellular senescence ,Review ,Disease ,Biology ,Young Adult ,03 medical and health sciences ,P16(INK4A) ,0302 clinical medicine ,Growth arrest ,cellular senescence ,Humans ,Senolytic ,senolytic medicine ,Exercise ,Mitosis ,Pathological ,11 Medical and Health Sciences ,Science & Technology ,senescent cells ,Small volume ,Cell Biology ,Middle Aged ,06 Biological Sciences ,APOPTOSIS ,030104 developmental biology ,DNA-DAMAGE ,senolytics ,SKELETAL-MUSCLE ,AUTOPHAGY ,Animal studies ,Life Sciences & Biomedicine ,030217 neurology & neurosurgery ,Developmental Biology - Abstract
Cellular senescence, a state of irreversible growth arrest triggered by various stressors, engages in a category of pathological processes, whereby senescent cells accumulate in mitotic tissues. Senolytics as novel medicine against aging and various diseases through the elimination of senescent cells has emerged rapidly in recent years. Exercise is a potent anti‐aging and anti‐chronic disease medicine, which has shown the capacity to lower the markers of cellular senescence over the past decade. However, whether exercise is a senolytic medicine for aging and various diseases remains unclear. Here, we have conducted a systematic review of the published literature studying the senolytic effects of exercise or physical activity on senescent cells under various states in both human and animal models. Exercise can reduce the markers of senescent cells in healthy humans, while it lowered the markers of senescent cells in obese but not healthy animals. The discrepancy between human and animal studies may be due to the relatively small volume of research and the variations in markers of senescent cells, types of cells/tissues, and health conditions. These findings suggest that exercise has senolytic properties under certain conditions, which warrant further investigations., Cellular senescent upregulates certain markers such as p16INK4a, p21Cip1, SA‐beta‐Gal, and/or SASP, which can also be shown in accelerated aging animals. This review discusses by using human and experimental laboratory animal studies to show how exercise attenuates all these senescent markers and serves as senolytic medicine.
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- 2020
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17. Concentration of Na+-taurocholate-cotransporting polypeptide expressed after in vitro-transcribed mRNA transfection determines susceptibility of hepatoma cells for hepatitis B virus
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Oswald, Andreas, Chakraborty, Anindita, Ni, Yi, Wettengel, Jochen M., Urban, Stephan, and Protzer, Ulrike
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Article ,Hepatitis B ,Transfection ,ddc - Published
- 2020
18. IL-1β-mediated macrophage infiltration into the brain after peripheral tissue injury
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Alvin C.H. Ma, Xiang Ke Chen, Gordon Tin Chun Wong, Kazi Md Mahmudul Hasan, Joseph Kwan, Zhen-Ni Yi, and Raymond Chuen-Chung Chang
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Pathology ,medicine.medical_specialty ,business.industry ,Macrophage infiltration ,medicine ,business ,Peripheral - Abstract
Background: Infiltration of macrophages into the central nervous system (CNS) is involved in many neurological disorders, such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and autism. Despite extensive studies into neuroinflammation associated macrophage infiltration into the CNS, its underlying mechanisms and pathological roles remain unclear, especially when triggered by peripheral inflammation. Methods: To further elucidate the role and mechanism of peripheral inflammation in neurological disorders, we exploited interleukin 1 beta (il1b) mutant transgenic zebrafish (Danio rerio) with fluorescent protein expression restricted to macrophages to track the macrophage migration under peripheral inflammation following tail amputation.Results: We found that macrophage infiltration into the brain of zebrafish embryo following peripheral tissue injury can be alleviated via genetically targeting il1b. In addition, through circulation-independent migration, macrophages infiltrate brains with evidence of increased apoptosis. We further identified the expression of camk2g1 in the brains of zebrafish with hyperactive behavior following peripheral tissue injury. This il1b-regulated protein is associated with neuropsychiatry disorders. Conclusion: These findings demonstrated that peripheral tissue injury induces il1b-mediated macrophage infiltration into the brain and a hyperactive behavior.
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- 2020
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19. Extending periodic automorphisms of surfaces to 3-manifolds
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Ni, Yi, Wang, Chao, and Wang, Shicheng
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Mathematics - Geometric Topology ,FOS: Mathematics ,Geometric Topology (math.GT) ,57M60 - Abstract
Let $G$ be a finite group acting on a connected compact surface $\Sigma$, and $M$ be an integer homology 3-sphere. We show that if each element of $G$ is extendable over $M$ with respect to a fixed embedding $\Sigma\rightarrow M$, then $G$ is extendable over some $M'$ which is 1-dominated by $M$. From this result, in the orientable category we classify all periodic automorphisms of closed surfaces that are extendable over the 3-sphere. The corresponding embedded surface of such an automorphism can always be a Heegaard surface., Comment: 17 pages, 5 figures
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- 2020
20. Exceptional surgeries on hyperbolic fibered knots
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Ni, Yi
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Mathematics - Geometric Topology ,FOS: Mathematics ,Geometric Topology (math.GT) - Abstract
Let $K\subset S^3$ be a hyperbolic fibered knot such that $S^3_{p/q}(K)$, the $\frac pq$--surgery on $K$, is non-hyperbolic. We prove that if the monodromy of $K$ is right-veering, then $0\le\frac pq\le 4g(K)$. The upper bound $4g(K)$ cannot be attained if $S^3_{p/q}(K)$ is a small Seifert fibered L-space. If the monodromy of $K$ is neither right-veering nor left-veering, then $|q|\le3$. As a corollary, for any given positive torus knot $T$, if $p/q\ge4g(T)+4$, then $p/q$ is a characterizing slope. This improves earlier bounds of Ni--Zhang and McCoy. We also prove that some finite/cyclic slopes are characterizing. More precisely, $14$ is characterizing for $T_{4,3}$, $17$ is characterizing for $T_{5,3}$, and $4n+1$ is characterizing for $T_{2n+1,2}$ except when $n=5$. By a recent theorem of Tange, this shows that $T_{2n+1,2}$ is the only knot in $S^3$ admitting a lens space surgery while the Alexander polynomial has the form $t^n-t^{n-1}+t^{n-2}+\text{lower order terms}$. In the appendix, we prove that if the rank of the second term of the knot Floer homology of a fibered knot is $1$, then the monodromy is either right-veering or left-veering., Comment: 12 pages, 2 figures. v2: Changed the title, the main result is now stated for exceptional surgeries, thanks to a result of Ying-Qing Wu. Revised a wrong citation of a theorem of Gabai, and the conclusion in one case became $|q|\le 3$ instead of $|q|\le 2$
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- 2020
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21. Hydrodeoxygenation of water-insoluble bio-oil to alkanes using a highly dispersed Pd–Mo catalyst
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Xusheng Zheng, Shik Chi Edman Tsang, Qian Wang, Haichao Liu, Alexander F. R. Kilpatrick, Titipong Issariyakul, Junting Feng, Yung-Kang Peng, Yadong Li, Meng Jung Li, Dongliang Chen, William K. Myers, Wenxing Chen, Dermot O'Hare, Yu Wang, Juncai Dong, Ni Yi, Xianrui Gu, Shufang Ji, Haohong Duan, and Jean-Charles Buffet
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inorganic chemicals ,Cyclohexane ,Science ,Destructive distillation ,General Physics and Astronomy ,chemistry.chemical_element ,Lignocellulosic biomass ,02 engineering and technology ,010402 general chemistry ,Heterogeneous catalysis ,01 natural sciences ,7. Clean energy ,complex mixtures ,Article ,General Biochemistry, Genetics and Molecular Biology ,Catalysis ,chemistry.chemical_compound ,Cellulose ,lcsh:Science ,Multidisciplinary ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical engineering ,13. Climate action ,lcsh:Q ,0210 nano-technology ,Hydrodeoxygenation ,Palladium - Abstract
Bio-oil, produced by the destructive distillation of cheap and renewable lignocellulosic biomass, contains high energy density oligomers in the water-insoluble fraction that can be utilized for diesel and valuable fine chemicals productions. Here, we show an efficient hydrodeoxygenation catalyst that combines highly dispersed palladium and ultrafine molybdenum phosphate nanoparticles on silica. Using phenol as a model substrate this catalyst is 100% effective and 97.5% selective for hydrodeoxygenation to cyclohexane under mild conditions in a batch reaction; this catalyst also demonstrates regeneration ability in long-term continuous flow tests. Detailed investigations into the nature of the catalyst show that it combines hydrogenation activity of Pd and high density of both Brønsted and Lewis acid sites; we believe these are key features for efficient catalytic hydrodeoxygenation behavior. Using a wood and bark-derived feedstock, this catalyst performs hydrodeoxygenation of lignin, cellulose, and hemicellulose-derived oligomers into liquid alkanes with high efficiency and yield., Bio-oil is a potential major source of renewable fuels and chemicals. Here, the authors report a palladium-molybdenum mixed catalyst for the selective hydrodeoxygenation of water-insoluble bio-oil to mixtures of alkanes with high carbon yield.
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- 2017
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22. Facile preparation of novel Cu–Zn–S film by spray pyrolysis
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Qinmiao Chen, Xiaoming Dou, Xifang Zhu, Ni Yi, Jin Chen, Hongcun Yuan, Xiaojun Xu, and Yoshinori Yamaguchi
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Materials science ,Scanning electron microscope ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Substrate (electronics) ,Zinc ,010402 general chemistry ,01 natural sciences ,law.invention ,Crystallinity ,chemistry.chemical_compound ,law ,Solar cell ,Electrical and Electronic Engineering ,Thin film ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Copper ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,chemistry ,Thiourea ,0210 nano-technology - Abstract
In this work, novel Cu–Zn–S (CZS) thin film for solar cell was successfully synthesized using a facile preparation method of spray pyrolysis. Copper (II) chloride dihydrate, zinc(II) acetate dihydrate and thiourea were used as reagents. The effect of varying the substrate temperature for the spray in terms of structural, optical, compositional, morphological and photovoltaic properties of the fabricated CZS film was investigated via X-ray diffraction, ultraviolet-visible-infrared spectroscopy, energy dispersive X-ray spectroscopy, scanning electron microscopy and J–V tester, respectively. As observed from the results, our novel CZS thin films have good crystallinity phase with bandgap of 2.21 eV and a conversion efficiency of 0.84% under optimal condition.
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- 2017
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23. Orthogonal functionalization of alternating polyesters: Selective patterning of (AB)n sequences
- Author
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Thomas T. D. Chen, Junjuda Unruangsri, Ni Yi, Yunqing Zhu, and Charlotte K. Williams
- Subjects
chemistry.chemical_classification ,010405 organic chemistry ,Alkene ,Carboxylic acid ,General Chemistry ,Polymer ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Polyester ,chemistry.chemical_compound ,Monomer ,Dynamic light scattering ,chemistry ,Copolymer ,Alkyl - Abstract
Precision functionalized polyesters, with defined monomer sequences, are prepared using an orthogonal post-polymerization strategy. These polyesters can be synthesized from bio-derived monomers and are targeted to degrade, by hydrolysis processes, to biocompatible diols and diacids; the new structures enabled by this methodology would be very difficult to synthesize by alternative strategies. A series of 9 well-defined highly alternating AB-type copolyesters, containing terminal and internal alkene functionalities, are synthesized in high conversions by the ring-opening copolymerization of epoxides and cyclic anhydrides. Firstly, the polyesters are functionalized by a selective hydroboration–oxidation reaction to exclusively and quantitatively hydroxylate the terminal alkenes, leaving the alternating internal alkenes unreacted. Subsequently, the internal alkenes are quantitatively transformed into carboxylic acid, amine, alkyl and oligo-ether groups, by thiol–ene reactions, to afford AB polyesters with alternating functional substituents. Three polyesters showing alternating hydrophilic/hydrophobic side-chain sequences self-assemble in solution to form nanostructures that are characterized using transmission electron microscopy and dynamic light scattering methods (Rh = 100–300 nm). The selective patterning methodology provides facile, efficient and orthogonal functionalization of alternating polyesters with near-quantitative (AB)n repeat sequences. The method is expected to be generalizable to other polymers and provides access to completely new AB alternating structures with the potential to exploit ligand multi-valency and adjacency to enhance properties.
- Published
- 2019
24. Orthogonal functionalization of alternating polyesters: selective patterning of (AB)
- Author
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Ni, Yi, Thomas T D, Chen, Junjuda, Unruangsri, Yunqing, Zhu, and Charlotte K, Williams
- Subjects
Chemistry - Abstract
A series of AB alternating polyesters are orthogonally patterned to install two different functionalities at regular intervals along the backbone and with high precision., Precision functionalized polyesters, with defined monomer sequences, are prepared using an orthogonal post-polymerization strategy. These polyesters can be synthesized from bio-derived monomers and are targeted to degrade, by hydrolysis processes, to biocompatible diols and diacids; the new structures enabled by this methodology would be very difficult to synthesize by alternative strategies. A series of 9 well-defined highly alternating AB-type copolyesters, containing terminal and internal alkene functionalities, are synthesized in high conversions by the ring-opening copolymerization of epoxides and cyclic anhydrides. Firstly, the polyesters are functionalized by a selective hydroboration–oxidation reaction to exclusively and quantitatively hydroxylate the terminal alkenes, leaving the alternating internal alkenes unreacted. Subsequently, the internal alkenes are quantitatively transformed into carboxylic acid, amine, alkyl and oligo-ether groups, by thiol–ene reactions, to afford AB polyesters with alternating functional substituents. Three polyesters showing alternating hydrophilic/hydrophobic side-chain sequences self-assemble in solution to form nanostructures that are characterized using transmission electron microscopy and dynamic light scattering methods (Rh = 100–300 nm). The selective patterning methodology provides facile, efficient and orthogonal functionalization of alternating polyesters with near-quantitative (AB)n repeat sequences. The method is expected to be generalizable to other polymers and provides access to completely new AB alternating structures with the potential to exploit ligand multi-valency and adjacency to enhance properties.
- Published
- 2019
25. Study on the Influence of Mesh Grouping on Numerical Simulation Results of Fish Cages
- Author
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Hui Cheng, Xinxin Wang, Fenfang Zhao, Gang Wang, Yuyan Li, Liuyi Huang, and Ni Yi
- Subjects
Computer simulation ,Environmental science ,%22">Fish ,Mooring ,Marine engineering - Abstract
The Morison Model is widely applied in the numerical simulation for the hydrodynamics assessment of fish cage. In the Morison model, hydrodynamic forces are calculated based on twines. To reduce the computational time, mesh grouping methods (replacement of multiple meshes with less number of equivalent meshes) have been implemented widely in the calculation. However, as the hydrodynamic equation for a mesh is quite different under wave and current, it is not appropriate to use the classical mesh grouping. On the basis of basic hydrodynamic equations of the meshes with current and wave, this paper carried out the study about theoretical analysis of two methods (the equivalent area method and the equivalent volume method) of the mesh grouping, using main parameters of nets such as the diameter, solidity ratio and elastic modulus related to mesh grouping. A single-point mooring cage, of which tension and displacement could be calculated with finite element method, was selected as a case to carry out the verification of two mesh grouping methods. Flume model experiment was used to validate the accuracy of mesh grouping methods. The results indicated that, the equivalent area method has a higher accuracy in the pure current condition, while the equivalent volume method was more accurate in combined waves and current. The accuracy of results using mesh grouping to analyze hydrodynamics of nets within a certain range of grouping times could be insured with an improved calculation speed. This paper can provide practical advice on the mesh grouping process in the numerical simulation of fish cages and fishing gear.
- Published
- 2019
- Full Text
- View/download PDF
26. Curcumin Inhibits Joint Contracture through PTEN Demethylation and Targeting PI3K/Akt/mTOR Pathway in Myofibroblasts from Human Joint Capsule
- Author
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Linlin Sun, Zheng Chen, Dezhao Liu, Yuangao Liu, Dongjie Yu, Guohui Yuan, Ze Zhuang, Ronghan He, Kun Wang, and Ni Yi-Rong
- Subjects
Article Subject ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Joint capsule ,medicine ,PTEN ,Joint Contracture ,Protein kinase B ,PI3K/AKT/mTOR pathway ,030304 developmental biology ,0303 health sciences ,biology ,Chemistry ,lcsh:Other systems of medicine ,lcsh:RZ201-999 ,medicine.anatomical_structure ,Complementary and alternative medicine ,030220 oncology & carcinogenesis ,biology.protein ,Cancer research ,Curcumin ,Contracture ,medicine.symptom ,Myofibroblast ,Research Article - Abstract
Joint contracture is increasingly regarded as a clinical problem that leads to irreversible dysfunction of the joint. It is a pathophysiological process following joint injury, which is marked by the activation of myofibroblasts. There is currently no effective treatment for the prevention of joint contracture. Curcumin is a polyphenol pigment extracted from turmeric, which possesses anti-inflammatory, antioxidative, and antitumor properties. In the present study, we demonstrated that curcumin exerts a protective effect against joint contracture via the inhibition of myofibroblast proliferation and migration in a time- and concentration-dependent manner. Moreover, we indicated that phosphatase and tension homolog (PTEN) was downregulated in myofibroblasts in vitro and in the contracture capsule tissues of patients in vivo. Additionally, western blot analysis revealed a negative correlation between the expression levels of PTEN and the fibrosis marker protein alpha smooth muscle cell actin. Methylation-specific PCR results suggested that curcumin was able to demethylate PTEN in a similar manner to the demethylation agent 5-azacytidine, increasing PTEN expression and further inhibiting phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling. In conclusion, our data illustrate part of the mechanism of curcumin inhibition in joint contracture. These results support the hypothesis that curcumin may potentially be used as a novel candidate for the treatment of joint contracture.
- Published
- 2019
27. Twitter Homophily: Network Based Prediction of User’s Occupation
- Author
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Ni Yi Puay, Wei Lu, Xinghao Pan, Jiaqi Pan, Hai Leong Chieu, and Rishabh Bhardwaj
- Subjects
Class (computer programming) ,Information retrieval ,Social network ,business.industry ,Computer science ,02 engineering and technology ,Homophily ,Data set ,020204 information systems ,0202 electrical engineering, electronic engineering, information engineering ,Graph (abstract data type) ,020201 artificial intelligence & image processing ,Fraction (mathematics) ,business - Abstract
In this paper, we investigate the importance of social network information compared to content information in the prediction of a Twitter user’s occupational class. We show that the content information of a user’s tweets, the profile descriptions of a user’s follower/following community, and the user’s social network provide useful information for classifying a user’s occupational group. In our study, we extend an existing data set for this problem, and we achieve significantly better performance by using social network homophily that has not been fully exploited in previous work. In our analysis, we found that by using the graph convolutional network to exploit social homophily, we can achieve competitive performance on this data set with just a small fraction of the training data.
- Published
- 2019
- Full Text
- View/download PDF
28. Numerical and Experimental Study of SPM Fish Cage: Comparison and Validation
- Author
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Qingchang Xu, Liuyi Huang, Hui Cheng, Xinxin Wang, Ni Yi, Zhenlin Liang, and Fenfang Zhao
- Subjects
Scanning probe microscopy ,Environmental science ,%22">Fish ,Cage ,Mooring ,Quantitative Biology::Other ,Marine engineering - Abstract
Deformations and drag forces of fish cages are two main problems in engineering design and optimization. To precisely predict these parameters, a combined numerical method, which combined the beam and truss elements, was used to study the deformation and drag forces of SPM (the single point mooring) fish cage in this paper. Flume model experiments were carried out to validate the accuracy of the numerical model. It is found that the numerical results agreed well with the experimental data, with the maximum and averaged errors of 13% and 5.9%, respectively. It can be conducted that this combined numerical model was useful in the designing and development of fish cages.
- Published
- 2018
- Full Text
- View/download PDF
29. The prism manifold realization problem III
- Author
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Ballinger, William, Ni, Yi, Ochse, Tynan, and Vafaee, Faramarz
- Subjects
Mathematics - Geometric Topology ,General Mathematics ,FOS: Mathematics ,57M25, 57R65 ,Geometric Topology (math.GT) - Abstract
Every prism manifold can be parametrized by a pair of relatively prime integers $p>1$ and $q$. In our earlier papers, we determined a complete list of prism manifolds $P(p, q)$ that can be realized by positive integral surgeries on knots in $S^3$ when $qp$; in the present work, we solve the case when $0, Comment: 34 pages, 5 figures
- Published
- 2018
- Full Text
- View/download PDF
30. Optimization of venous return tubing diameter for cardiopulmonary bypass
- Author
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Ni, Yi-ming, Leskosek, Boris, Shi, Li-ping, Chen, Ying-lian, Qian, Lin-feng, Li, Ren-yuan, Tu, Zheng-liang, von Segesser, Ludwig K, University of Zurich, and von Segesser, Ludwig K
- Subjects
2740 Pulmonary and Respiratory Medicine ,610 Medicine & health ,142-005 142-005 ,2705 Cardiology and Cardiovascular Medicine ,2746 Surgery - Abstract
Objective: To determine the optimal venous tubing diameter for adult cardiopulmonary bypass (CPB) to improve gravity drainage and to reduce priming volume. Methods: (A) Maximum bovine blood flow rates by gravity drainage were assessed in vitro for four different tubing diameters (1/2, 3/8, 5/16,1/4 inch) with three different lengths and various pre- and afterloads. Based on the results of (A) and multiple regression analyses, we developed equations to predict tubing sizes as a function of target flows. (C) The equations obtained in (B) were validated by ex vivo bovine experiments. (D) The clinically required maximal flows were determined retrospectively by reviewing 119 perfusion records at Zurich University. (E) Based on our model (B), the clinical patient and hardware requirements, the optimal venous tubing diameter was calculated. (F) The optimized venous tubing was evaluated in a prospective clinical trial involving 312 patients in Hangzhou. Results: For a mean body surface area of 1.83±0.2 m2, the maximal perfusion flow rate (D) achieved with 1/2-inch (=1.27 cm2) venous tubing was 4.62±0.57 l/min (range: 2.50-6.24 l/min). Our validated model (B,C) predicted 1.0 cm2 as optimal cross-sectional area for the venous line. New tubing packs developed accordingly were used routinely thereafter. The maximal flow rate was 4.93±0.58 l/min (range: 3.9-7.0) in patients with a mean body surface area of 1.62±0.21 m2. Conclusion: The new venous tubing with 1.0-cm2 cross-sectional area improves the drainage in the vast majority of adult patients undergoing CPB and reduces the priming volume (−27 ml/m). Reduced hemodilution can prevent homologous transfusions if a predefined transfusion trigger level is not reached
- Published
- 2017
31. Multi longitudinal mode beat frequency fiber laser displacement sensor based on substrate
- Author
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郭 瑜 Guo Yu, 余 涛 Yu Tao, and 倪 屹 Ni Yi
- Subjects
Longitudinal mode ,Materials science ,Space and Planetary Science ,business.industry ,Fiber laser ,Aerospace Engineering ,Optoelectronics ,Displacement (orthopedic surgery) ,Substrate (printing) ,Electrical and Electronic Engineering ,business ,Atomic and Molecular Physics, and Optics - Published
- 2019
- Full Text
- View/download PDF
32. Structural Design and Performance Analysis of Specific Protein Analyzer Based on Concave Grating
- Author
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Ni Yi, Li Junwei, Guo Yu, Zhang Xiaotian, Fan Junxing, and Zhong Daohong
- Subjects
Specific protein ,Spectrum analyzer ,Materials science ,Optics ,business.industry ,Grating ,business ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2019
- Full Text
- View/download PDF
33. RTM scattered artifacts removal by illumination compensation method – application in streamer data
- Author
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Wang Wei, Wang Hai Kun, Wang Zheng, Jiao Xu Ming, Ni Xuecan, and Ni Yi
- Subjects
010504 meteorology & atmospheric sciences ,Computer science ,business.industry ,Computer graphics (images) ,Computer vision ,Artificial intelligence ,010502 geochemistry & geophysics ,business ,01 natural sciences ,0105 earth and related environmental sciences ,Compensation (engineering) - Published
- 2016
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- View/download PDF
34. New Double-Loop Desensitization FBG Strain Sensor
- Author
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倪屹 Ni Yi, 朱星盈 Zhu Xingying, 刘化利 Liu Huali, and 郭瑜 Guo Yu
- Subjects
Double loop ,Materials science ,medicine.medical_treatment ,medicine ,Biophysics ,Strain sensor ,Electrical and Electronic Engineering ,Atomic and Molecular Physics, and Optics ,Desensitization (medicine) - Published
- 2018
- Full Text
- View/download PDF
35. Temperature Compensation Technique Applied to 3-Dimensional Fiber Bragg Grating Strain Sensor
- Author
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王娟 Wang Juan, 倪屹 Ni Yi, 朱星盈 Zhu Xingying, 郭瑜 Guo Yu, and 李岱林 Li Dailin
- Subjects
Optics ,Materials science ,Fiber Bragg grating ,business.industry ,Strain sensor ,Electrical and Electronic Engineering ,business ,Atomic and Molecular Physics, and Optics ,Compensation (engineering) - Published
- 2018
- Full Text
- View/download PDF
36. Experiments of Multi-Level Read-Only Recording Using Readout Signal Wave-Shape Modulation
- Author
-
Pan Long-fa, Zhang Bu-Qing, Hu Hua, Ni Yi, Pei Jing, and Tang Yi
- Subjects
Computer science ,Modulation ,Electronic engineering ,Bit error rate ,General Physics and Astronomy ,High definition ,Signal ,Signal wave ,Symbol (chemistry) - Abstract
An innovative multilevel read-only recording method is proposed. In this method, a short pit/land is deliberately inserted to the original land/pit. This modifies the wave-shape of readout signal. Taking the wave-shape as the symbol of level detection, a signal wave-shape modulation (SWSM) multilevel method is realized. This method is carried out and validated on the DVD read-only manufacture and readout system. A capacity of 15 GB can be expected, and a bit error rate of 10−4 is achieved. The capacity can meet the demand of high definition movie publication. This method also provides a potential multi-level solution for other storage formats and systems.
- Published
- 2008
- Full Text
- View/download PDF
37. Correction terms, Z_2-Thurston norm, and triangulations
- Author
-
Ni, Yi and Wu, Zhongtao
- Subjects
Mathematics::Symplectic Geometry ,Mathematics::Geometric Topology - Abstract
We explicitly construct layered-triangulations for manifolds admitting a genus-one open book decomposition with connected binding. This construction gives an upper bound to the complexity of these manifolds. In a different direction, we show that the correction terms in Heegaard Floer homology give a lower bound to the genus of one-sided Heegaard splittings and the Z_2-Thurston norm. Using a result of Jaco–Rubinstein–Tillmann, this gives a lower bound to the complexity of certain closed 3-manifolds. We illustrate our theorems with some examples.
- Published
- 2015
38. Restriction of shot noise and material noise in a multilevel photochromic memory on signal-to-noise ratio
- Author
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Xu Duan-Yi, Zhang Qi-Cheng, Ni Yi, and Hu Heng
- Subjects
Physics ,business.industry ,Noise spectral density ,Quantum noise ,Shot noise ,General Physics and Astronomy ,Noise figure ,Noise floor ,Burst noise ,symbols.namesake ,Optics ,Noise generator ,Gaussian noise ,symbols ,business ,Computer Science::Information Theory - Abstract
The recording density of multilevel photochromic memory is limited by the signal-to-noise ratio (SNR) of the readout signal. In this paper, shot noise and material noise are investigated through theoretical analysis of SNR. When the bandwidth of a system is less than 1MHz, the material noise takes a prominent position; when the bandwidth of the system is more than 10MHz, the shot noise becomes dominant. The thickness of recording layer can be optimized to maximize the SNR and reduce the influence of the bandwidth of the system on SNR.
- Published
- 2006
- Full Text
- View/download PDF
39. Large negative dispersion in square solid-core photonic bandgap fibers
- Author
-
Ni Yi
- Subjects
Optical fiber ,Materials science ,business.industry ,Physics::Optics ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,law.invention ,Zero-dispersion wavelength ,Optics ,Polarization mode dispersion ,law ,Dispersion (optics) ,Mode coupling ,Optoelectronics ,Fiber ,Electrical and Electronic Engineering ,business ,Refractive index ,Photonic crystal - Abstract
In this paper, a Ge-doping square solid-core photonic bandgap (PBG) fiber is proposed and the effective index of defect mode is investigated. Simulations show that, at the starting wavelength of the defect mode, n/sub effd/ (the effective index of defect mode) changes rapidly due to the PBG effect, which induces large negative dispersion in fiber. This mechanism is different from the mode coupling case in dual-core concentric fibers, and the dispersion characteristic is more robust to structural deviations.
- Published
- 2005
- Full Text
- View/download PDF
40. Entangled photon-pair source based on photonic crystal fiber
- Author
-
Peng Jiang-De, Liu Xiao-Ming, Wang Qing, Ni Yi, Zhou Bingkun, and Zhang Lei
- Subjects
Physics ,Optical fiber ,Photon ,business.industry ,Physics::Optics ,Nonlinear optics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Mathematics::Logic ,Four-wave mixing ,Wavelength ,Optics ,law ,Dispersion (optics) ,Computer Science::Programming Languages ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,business ,Photonic crystal ,Photonic-crystal fiber - Abstract
Flexible dispersion of photonic crystal fiber (PCF) has been demonstrated with the help of Hermite–Gaussian functions. Parametric fluorescence (PF) based on four wave mixing (FWM) in PCF with zero-dispersion wavelength at 0.85, 1.33 and 1.55 μm have been simulated, respectively. Simulations show that PCF can be used to generate efficient photon-pairs on desired wavelength.
- Published
- 2004
- Full Text
- View/download PDF
41. Confinement loss in solid-core photonic bandgap fibers
- Author
-
Xie Yuejian, Zhang Lei, Ni Yi, Peng Jiang-De, and An Liang
- Subjects
Materials science ,Computer simulation ,business.industry ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,Solid core ,Fiber ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,business ,Pitch ratio ,Refractive index ,Photonic bandgap ,Photonic crystal - Abstract
It is shown in this paper through simulation that the confinement loss of a down-doped solid-core photonic bandgap (PBG) fiber can be reduced to the level of 0.01 dB/km by only 84 air holes, with an air hole diameter to pitch ratio d / Λ =0.8 and air-filling fraction=35%. The practicality of solid-core PBG fibers is thus enhanced.
- Published
- 2004
- Full Text
- View/download PDF
42. Optical Time Domain Reflectometry Based on LabVIEW and Detection Analysis of Reflection Events
- Author
-
王娟 Wang Juan, 郭瑜 Guo Yu, 朱星盈 Zhu Xingying, and 倪屹 Ni Yi
- Subjects
Physics ,Optics ,business.industry ,Reflection (physics) ,Time domain ,Electrical and Electronic Engineering ,business ,Reflectometry ,Atomic and Molecular Physics, and Optics - Published
- 2017
- Full Text
- View/download PDF
43. Design of laser array based on REC technology
- Author
-
倪 屹 Ni Yi, 姚辉轩 Yao Huixuan, and 秦逸轩 Qin Yixuan
- Subjects
Materials science ,Optics ,Space and Planetary Science ,business.industry ,Aerospace Engineering ,Electrical and Electronic Engineering ,Laser array ,business ,Atomic and Molecular Physics, and Optics - Published
- 2017
- Full Text
- View/download PDF
44. Study on standard query language query in heterogeneous database
- Author
-
Ni Yi and Wu Kaiyi
- Subjects
Information retrieval ,Database ,Computer science ,View ,computer.software_genre ,Query language ,Query optimization ,Query expansion ,Web query classification ,Query by Example ,Sargable ,computer ,computer.programming_language ,RDF query language - Published
- 2014
- Full Text
- View/download PDF
45. Dehn surgery on knots in $S^3$ producing Nil Seifert fibred spaces
- Author
-
Ni, Yi and Zhang, Xingru
- Subjects
Mathematics - Geometric Topology ,57M25 ,FOS: Mathematics ,Geometric Topology (math.GT) ,Mathematics::Symplectic Geometry ,Mathematics::Geometric Topology - Abstract
We prove that there are exactly $6$ Nil Seifert fibred spaces which can be obtained by Dehn surgeries on non-trefoil knots in $S^3$, with $\{60, 144, 156, 288, 300\}$ as the exact set of all such surgery slopes up to taking the mirror images of the knots. We conjecture that there are exactly $4$ specific hyperbolic knots in $S^3$ which admit Nil Seifert fibred surgery. We also give some more general results and a more general conjecture concerning Seifert fibred surgeries on hyperbolic knots in $S^3$., Comment: 11 pages
- Published
- 2014
- Full Text
- View/download PDF
46. Correction terms, $\mathbb Z_2$--Thurston norm, and triangulations
- Author
-
Ni, Yi and Wu, Zhongtao
- Subjects
Mathematics - Geometric Topology ,FOS: Mathematics ,Geometric Topology (math.GT) ,57M27, 57Q15 ,Mathematics::Symplectic Geometry ,Mathematics::Geometric Topology - Abstract
We show that the correction terms in Heegaard Floer homology give a lower bound to the the genus of one-sided Heegaard splittings and the $\mathbb Z_2$--Thurston norm. Using a result of Jaco--Rubinstein--Tillmann, this gives a lower bound to the complexity of certain closed $3$--manifolds. As an application, we compute the $\mathbb Z_2$--Thurston norm of the double branched cover of some closed 3--braids, and give upper and lower bounds for the complexity of these manifolds., Comment: 20 pages, 5 figures
- Published
- 2014
- Full Text
- View/download PDF
47. Diagnosis of individual cell frequencies in a coupled cavity chain without introducing objects into the cavity
- Author
-
Lin Yuzheng, Xiao Liling, Ni Yi, and Tong Dechun
- Subjects
Physics ,Nuclear and High Energy Physics ,Flatness (systems theory) ,Topology ,law.invention ,k-nearest neighbors algorithm ,Quality (physics) ,Nuclear Energy and Engineering ,Normal mode ,law ,Control theory ,Optical cavity ,Equivalent circuit ,Electrical and Electronic Engineering ,Passband ,Microwave cavity - Abstract
This paper presents a new method to diagnose cell frequencies in a cavity without a probe inside the cavity. The equivalent circuit model of a coupled cavity chain is used to estimate the cell frequencies and couplings between cells in terms of the measured passband performance. Two assumptions used to simplify the numerical process are that the next nearest neighbor couplings between the cells are taken as zero and the quality factors of cells are unchanged in the tuning procedure and defined in advance. This method can simplify the tuning process and makes possible the tuning of a sealed cavity. The procedure has been verified with numerical and experimental examples and can be used as a guide to adjust the normal modes and field flatness in a real cavity.
- Published
- 2001
- Full Text
- View/download PDF
48. Genetic algorithm diagnosis of individual cell frequencies in a coupled cavity chain
- Author
-
Lin Yuzheng, Tong Dechun, and Ni Yi
- Subjects
Physics ,Nuclear and High Energy Physics ,Nonlinear system ,Optimization problem ,Chain (algebraic topology) ,Non-linear least squares ,Convergence (routing) ,Genetic algorithm ,Function (mathematics) ,Topology ,Instrumentation - Abstract
Genetic algorithms (GAs) are used to diagnose individual cell frequencies in a coupled cavity chain without any perturbing objects. The cell frequencies and couplings between the cells are determined in terms of the measured pass-band performance. The analysis simplifies the tuning processes and enables the tuning of the sealed cavities possible. The problem is solved as an optimization problem with GAs used as a function optimizer. The convergence is improved using the nonlinear least-squares method as a modification of the GAs, which also improves the precision of the solution. The effectiveness of the new technique is demonstrated through some numerical examples and the results are compared with those of the conventional GAs.
- Published
- 2001
- Full Text
- View/download PDF
49. [Development of national neglect norm for urban primary school students of China]
- Author
-
Jian-ping, Pan, Fei, Wang, Min, Li, Jing-qi, Chen, Hui-ying, Zhang, Gui-xiang, Wang, Gui-xiong, Gu, Wei-wei, Guo, Yu-lin, Peng, Shu-hua, Shi, Guang-hu, Chen, Hua-ni, Yi, Ping, Fu, Li, Xia, Hong, Yu, Biao, Lu, Zhi-xian, Duan, Ying-xiong, Wang, Zhao-hui, Zhong, Jian, Li, Lin, Wang, Chun-hong, Cao, Sha-sha, Luo, Song-jie, Zhang, and Hua, Zhang
- Subjects
Male ,China ,Schools ,Surveys and Questionnaires ,Humans ,Reproducibility of Results ,Female ,Child Abuse ,Child ,Students - Abstract
To develop the national neglect norms for urban primary school students in China.According to multi-stage stratified cluster sampling principle, 24 cities of 13 provinces (municipalities) in China were selected during December 1 to 31, 2008. A total of 1491 students in grade 1 - 3 and 2236 students in grade 4 - 6 were selected. Questionnaire was designed by authors and the final norms were determined through several statistical analysis methods, such as item analysis method, factor analysis method, reliability analysis method. The reliability analysis and validity analysis were used to test the stability and reliability of the norms. The evaluation criteria of the scale was determined by the percentile method, then the initial development of the norm was completed.The two questionnaires of grade 1 - 3 and grade 4 - 6 students consisted of 55 and 57 items, respectively, whose item loadings were ranged from 0.301 to 0.687 and 0.321 to 0.730, which met the statistical requirements. For grade 1 - 3 students, the scale's total Cronbach α coefficients was 0.914, the total split-half reliability coefficients was 0.896, the Cronbach α coefficients of four level was above 0.737 except medical and social neglect, split-half reliability was ranged from 0.461 to 0.757; for grade 4-6 students, the scale's total Cronbach α coefficients was 0.916, split-half reliability was 0.883, except social neglect, the Cronbach α coefficients of other level was ranged 0.457 to 0.856, split-half reliability was ranged from 0.500 to 0.798. The total neglect cut-off score of the two scales grade 1-3 and 4-6 were 125 and 155, respectively.The structure of two norms was reasonable. The scales have good stability and reliability.
- Published
- 2013
50. Non-simple genus minimizers in lens spaces
- Author
-
Greene, Joshua Evan and Ni, Yi
- Subjects
Mathematics - Geometric Topology ,57M25, 57M27 ,FOS: Mathematics ,Geometric Topology (math.GT) ,Mathematics::Symplectic Geometry ,Mathematics::Geometric Topology - Abstract
Given a one-dimensional homology class in a lens space, a question related to the Berge conjecture on lens space surgeries is to determine all knots realizing the minimal rational genus of all knots in this homology class. It is known that simple knots are rational genus minimizers. In this paper, we construct many non-simple genus minimizers. This negatively answers a question of Rasmussen., 16 pages, 6 figures
- Published
- 2013
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