127 results on '"Nai Y"'
Search Results
2. TRAIL-R1-targeted chimeric antigen receptor T cells exhibit dual antitumor effects
- Author
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Jin A, Pang D, Nai Y, Huang J, Du L, Luo F, Shen M, Li T, and Han x
- Subjects
Text mining ,business.industry ,Chemistry ,Cancer research ,DUAL (cognitive architecture) ,business ,Chimeric antigen receptor ,Trail r1 - Abstract
Tumor necrosis factor-related apoptosis-inducing ligand receptor 1 (TRAIL-R1) has limited expression in normal tissues but highly expression in a broad range of tumors, making it an attractive target for cancer immunotherapy. We have previously prepared a fully human monoclonal antibody targeting TRAIL-R1 (TR1419), which can specifically induce apoptosis in antigen-positive tumor cells. Here, we prepared the TR1419CAR-T cells using the single chain variable fragment (scFv) from TR1419, which were evaluated for the phenotypes and function. The TR1419CAR-T cells induced cytolysis of TRAIL-R1-positive tumor cells not only via activation of the death receptor-dependent apoptotic pathway, but also via T-cell mediated cytotoxicity. Furthermore, compared to the second-generation TR1419-28ζ and TR1419-BBζ CAR-T cells, the third-generation TR1419-28BBζ CAR-T cells had greater sensitivity to target antigen, exhibited a better proliferative ability, but showed slightly higher PD-1 expression after antigen stimulation. Altogether, TR1419CAR-T cells, especially TR1419-28BBζCAR-T cells could be a promising treatment strategy for TRAIL-R1 positive tumors.
- Published
- 2021
3. Mcam inhibits macrophage-mediated development of mammary gland through non-canonical Wnt signaling
- Author
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Xing Yang, Haibo Xu, Xu Yang, Hui Wang, Li Zou, Qin Yang, Xiaopeng Qi, Li Li, Hongxia Duan, Xiyun Yan, Nai Yang Fu, Jing Tan, Zongliu Hou, and Baowei Jiao
- Subjects
Science - Abstract
Abstract While canonical Wnt signaling is well recognized for its crucial regulatory functions in cell fate decisions, the role of non-canonical Wnt signaling in adult stem cells remains elusive and contradictory. Here, we identified Mcam, a potential member of the non-canonical Wnt signaling, as an important negative regulator of mammary gland epithelial cells (MECs) by genome-scale CRISPR-Cas9 knockout (GeCKO) library screening. Loss of Mcam increases the clonogenicity and regenerative capacity of MECs, and promotes the proliferation, differentiation, and ductal morphogenesis of mammary epithelial in knockout mice. Mechanically, Mcam knockout recruits and polarizes macrophages through the Il4-Stat6 axis, thereby promoting secretion of the non-canonical Wnt ligand Wnt5a and its binding to the non-canonical Wnt signaling receptor Ryk to induce the above phenotypes. These findings reveal Mcam roles in mammary gland development by orchestrating communications between MECs and macrophages via a Wnt5a/Ryk axis, providing evidences for non-canonical Wnt signaling in mammary development.
- Published
- 2024
- Full Text
- View/download PDF
4. Heinz Heinemann’s Legacy at ExxonMobil: An Illustrious Career in Industrial Catalysis
- Author
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Degnan, Jr., Thomas F., Chen, Nai Y., and Somorjai, Gabor A.
- Published
- 2009
- Full Text
- View/download PDF
5. Shape-Selective Catalysis
- Author
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CHUNSHAN SONG, JUAN M. GARCÉS, YOSHIHIRO SUGI, Chunshan Song, Juan M. Garcés, Yoshihiro Sugi, Paul B. Weisz, Nai Y. Chen, Paul B. Venuto, Asim Bhaumik, Takashi Tatsumi, Guan-Guang Xia, Jin-Yun Wang, Nian-Gao Duan, Ying Ma, Steven L. Suib, Clarence D. Chang, Tomoyuki Inui, T. S. R. Prasada Rao, N. Vi
- Published
- 1999
6. PTPN23 ubiquitination by WDR4 suppresses EGFR and c-MET degradation to define a lung cancer therapeutic target
- Author
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Shaifali Singh, Nai Yang Yeat, Ya-Ting Wang, Shu-Yu Lin, I-Ying Kuo, Kuen-Phon Wu, Won-Jing Wang, Wen-Ching Wang, Wu-Chou Su, Yi-Ching Wang, and Ruey-Hwa Chen
- Subjects
Cytology ,QH573-671 - Abstract
Abstract Aberrant overexpression or activation of EGFR drives the development of non-small cell lung cancer (NSCLC) and acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) by secondary EGFR mutations or c-MET amplification/activation remains as a major hurdle for NSCLC treatment. We previously identified WDR4 as a substrate adaptor of Cullin 4 ubiquitin ligase and an association of WDR4 high expression with poor prognosis of lung cancer. Here, using an unbiased ubiquitylome analysis, we uncover PTPN23, a component of the ESCRT complex, as a substrate of WDR4-based ubiquitin ligase. WDR4-mediated PTPN23 ubiquitination leads to its proteasomal degradation, thereby suppressing lysosome trafficking and degradation of wild type EGFR, EGFR mutant, and c-MET. Through this mechanism, WDR4 sustains EGFR and c-MET signaling to promote NSCLC proliferation, migration, invasion, stemness, and metastasis. Clinically, PTPN23 is downregulated in lung cancer and its low expression correlates with WDR4 high expression and poor prognosis. Targeting WDR4-mediated PTPN23 ubiquitination by a peptide that competes with PTPN23 for binding WDR4 promotes EGFR and c-MET degradation to block the growth and progression of EGFR TKI-resistant NSCLC. These findings identify a central role of WDR4/PTPN23 axis in EGFR and c-MET trafficking and a potential therapeutic target for treating EGFR TKI-resistant NSCLC.
- Published
- 2023
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7. A Newly Designed EGFP-2A Peptide Monocistronic Baculoviral Vector for Concatenating the Expression of Recombinant Proteins in Insect Cells
- Author
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Nai Y.-S., Wang C.-H., Chu P.-Y., Huang C.-W., Wu C.-Y., and Ding S.-T.
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0301 basic medicine ,Signal peptide ,N-linked glycosylation ,Multiprotein complex ,Glycosylation ,Bioengineering ,Peptide ,lcsh:Chemical technology ,law.invention ,Green fluorescent protein ,lcsh:Chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,multimer formation ,law ,Chemical Engineering (miscellaneous) ,lcsh:TP1-1185 ,recombinant porcine adiponectin ,Selectable marker ,chemistry.chemical_classification ,2A-mediated “cleavage” process ,Process Chemistry and Technology ,Cell biology ,030104 developmental biology ,chemistry ,lcsh:QD1-999 ,Recombinant DNA ,baculovirus expression system ,030217 neurology & neurosurgery - Abstract
Recombinant proteins produced by the baculovirus expression vector system (BVES) have been widely applied in the agricultural and medical fields. However, the procedure for protein expression is inefficient and needs to be improved. Herein, we propose a simple construct that incorporates a selectable marker (enhanced green fluorescent protein, EGFP) and a picorna viral-derived &ldquo, self-cleaving&rdquo, 2A-like peptide to separate the EGFP and target proteins in a monocistronic baculovirus vector to facilitate isolation of the recombinant baculovirus in the BVES. In this study, porcine adiponectin (ADN), a secreted, multimeric protein with insulin-sensitizing properties, was used to demonstrate its utility in our EGFP-2A-based expression system. EGFP and ADN were simultaneously expressed by a recombinant alphabaculovirus. Co-expression of EGFP facilitates the manipulation of the following processes, such as determining expression kinetics and harvesting ADN. The results showed that the 2A &ldquo, process does not interfere with EGFP activity or with signal peptide removal and the secretion of recombinant ADN. Posttranslational modifications, including glycosylation, of the recombinant ADN occurred in insect cells, and the formation of various multimers was further verified. Most importantly, the insect-produced ADN showed a similar bioactivity to that of mammalian cells. This concept provides a practical and economic approach that utilizes a new combination of alphabaculovirus/insect cell expression systems for future applications.
- Published
- 2019
8. Correction: PTPN23 ubiquitination by WDR4 suppresses EGFR and c-MET degradation to define a lung cancer therapeutic target
- Author
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Shaifali Singh, Nai Yang Yeat, Ya-Ting Wang, Shu-Yu Lin, I-Ying Kuo, Kuen-Phon Wu, Won-Jing Wang, Wen-Ching Wang, Wu-Chou Su, Yi-Ching Wang, and Ruey-Hwa Chen
- Subjects
Cytology ,QH573-671 - Published
- 2024
- Full Text
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9. Recent Advances in Shape-Selective Catalysis and Its Industrial Applications
- Author
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Chen, Nai Y., primary
- Published
- 1999
- Full Text
- View/download PDF
10. An environmentally friendly oil industry?
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Chen, Nai Y.
- Subjects
Petroleum industry -- Environmental aspects ,Petroleum refineries -- Design and construction ,Green technology -- Economic aspects ,Petroleum chemicals industry -- Environmental aspects ,Chemistry -- Innovations ,Business ,Chemicals, plastics and rubber industries ,Chemistry ,Engineering and manufacturing industries ,Comprehensive National Energy Policy Act of 1992 - Abstract
Environmental aspects of the oil industry are discussed by a technical consultant and energy conservation advocate. Government regulation, alternative fuels, and environmental concerns may shift the economic balance toward new refineries designed to avoid problems in a proactive approach. Topics include unit size and product distribution, costs/profits, comparing startup and older refineries, and integrating fuel refining and petrochemicals. Tables give data of various kinds.
- Published
- 2001
11. Energy in the 21st century
- Author
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Chen, Nai Y.
- Subjects
Power resources -- Supply and demand ,Petroleum industry -- Planning ,Electric power-plants -- Energy use ,Transportation industry -- Energy use ,Biomass -- Usage ,Alternative energy sources -- Research ,Petroleum refineries -- Product information ,Energy industry -- Planning ,Pollution -- Prevention ,Fossil fuels -- Usage ,Fuel industry -- Planning ,Electric utilities -- Planning ,Population -- Statistics ,Gasoline -- Supply and demand ,Gasoline industry -- Planning ,Electric power production -- Environmental aspects ,Transportation -- History ,Gas industry -- Supply and demand ,Catalysts -- Product development ,Specialty chemicals industry -- Product development ,Business ,Chemicals, plastics and rubber industries ,Chemistry ,Engineering and manufacturing industries - Abstract
Improvement in worldwide standards of living add up to higher energy consumption; ways must be found to produce more, despite natural resource shortages and environmental demands according to a technical consultant and energy conservation advocate. Technical challenges related to resources involve natural gas, crude oil/carbonaceous resources, biomass and noncarbonaceous resources, such as nuclear fission. Cleaner liquid fuels are an aspect of processing challenges. Topics include population/consumption, catalysts and other chemical aspects, the future of processing. historical patterns of energy use in the US, fuel cells, transportation in the US, emissions of carbon dioxide, and energy efficiencies. Tables compare carbon emission with other factors, US and China, give projected worldwide energy demand, 2000, 2030, World, OECD and non-OECD, and charts show primary energy sources in the US since early 19th century, US distribution of intercity transportation mileage. Royal-Dutch/Shell and ExxonMobil are mentioned.
- Published
- 2001
12. TRABID inhibition activates cGAS/STING-mediated anti-tumor immunity through mitosis and autophagy dysregulation
- Author
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Yu-Hsuan Chen, Han-Hsiun Chen, Won-Jing Wang, Hsin-Yi Chen, Wei-Syun Huang, Chien-Han Kao, Sin-Rong Lee, Nai Yang Yeat, Ruei-Liang Yan, Shu-Jou Chan, Kuen-Phon Wu, and Ruey-Hwa Chen
- Subjects
Science - Abstract
Abstract Activation of tumor-intrinsic innate immunity has been a major strategy for improving immunotherapy. Previously, we reported an autophagy-promoting function of the deubiquitinating enzyme TRABID. Here, we identify a critical role of TRABID in suppressing anti-tumor immunity. Mechanistically, TRABID is upregulated in mitosis and governs mitotic cell division by removing K29-linked polyubiquitin chain from Aurora B and Survivin, thereby stabilizing the entire chromosomal passenger complex. TRABID inhibition causes micronuclei through a combinatory defect in mitosis and autophagy and protects cGAS from autophagic degradation, thereby activating the cGAS/STING innate immunity pathway. Genetic or pharmacological inhibition of TRABID promotes anti-tumor immune surveillance and sensitizes tumors to anti-PD-1 therapy in preclinical cancer models in male mice. Clinically, TRABID expression in most solid cancer types correlates inversely with an interferon signature and infiltration of anti-tumor immune cells. Our study identifies a suppressive role of tumor-intrinsic TRABID in anti-tumor immunity and highlights TRABID as a promising target for sensitizing solid tumors to immunotherapy.
- Published
- 2023
- Full Text
- View/download PDF
13. Measurement of Free Fraction in Plasma for Biomathematical Prediction of SUVR of Amyloid PET Radiotracers
- Author
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Nai, Y.-H., Shidahara, M., Seki, C., Watanuki, S., Funaki, Y., Ishikawa, Y., Furumoto, S., and Watabe, H.
- Published
- 2015
14. Focus on autonomic dysfunctions in anti-NMDAR encephalitis: a case report.
- Author
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REN, C., NAI, Y., LV, W., LIU, H., CHEN, Q., SUN, Z.-W., WANG, J.-H., GUAN, L.-N., GONG, L., and WANG, X.-T.
- Abstract
OBJECTIVE: We hope it will provide a reference for early detection, early diagnosis, and early treatment of atypical Anti- N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis with non-typical autonomic dysfunctions as the first symptom. PATIENTS AND METHODS: We present a 15-year-old girl with the repetition of conscious disturbance at different levels, but no abnormal movements. Initially, there were no positive findings on routine electroencephalography (EEG) and dynamic video-electroencephalography (V-EEG), but the head-up tilt test (HTT) suggested neurocardiogenic syncope (vascular rejection type), which seemed to be the final diagnosis. However, the patient later experienced several episodes of disturbance of consciousness with unexplained abdominal pain. Abnormalities were discovered on EEG, which indicated the possibility of “epileptic seizures with autonomic-gastrointestinal features”. Based on these findings, we finally tested the autoimmune encephalitis-related antibodies for the patient after the literature search and review. RESULTS: The patient was finally diagnosed with anti-NMDAR encephalitis. Her symptoms were fully controlled after glucocorticoid and gamma globulin treatment, and she left the hospital with complete recovery. CONCLUSIONS: Although autonomic nervous dysfunction occurred in our patient, her prognosis was good because she did not have respiratory or (and) circulatory failure. Exclusive diagnosis and early treatment are important in patients with anti-NMDAR encephalitis. Abdominal pain with positive HTT may be a manifestation of autonomic dysfunction in this disease. [ABSTRACT FROM AUTHOR]
- Published
- 2019
15. Current development of biosensing technologies towards diagnosis of mental diseases
- Author
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Yuhan Zheng, Chen Liu, Nai Yeen Gavin Lai, Qingfeng Wang, Qinghua Xia, Xu Sun, and Sheng Zhang
- Subjects
biosensors ,mental diseases ,eye-tracking ,EEG signals ,EOG signals ,virtual reality ,Biotechnology ,TP248.13-248.65 - Abstract
The biosensor is an instrument that converts the concentration of biomarkers into electrical signals for detection. Biosensing technology is non-invasive, lightweight, automated, and biocompatible in nature. These features have significantly advanced medical diagnosis, particularly in the diagnosis of mental disorder in recent years. The traditional method of diagnosing mental disorders is time-intensive, expensive, and subject to individual interpretation. It involves a combination of the clinical experience by the psychiatrist and the physical symptoms and self-reported scales provided by the patient. Biosensors on the other hand can objectively and continually detect disease states by monitoring abnormal data in biomarkers. Hence, this paper reviews the application of biosensors in the detection of mental diseases, and the diagnostic methods are divided into five sub-themes of biosensors based on vision, EEG signal, EOG signal, and multi-signal. A prospective application in clinical diagnosis is also discussed.
- Published
- 2023
- Full Text
- View/download PDF
16. Molecular Regulation and Oncogenic Functions of TSPAN8
- Author
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Jicheng Yang, Ziyan Zhang, Joanne Shi Woon Lam, Hao Fan, and Nai Yang Fu
- Subjects
TSPAN8 ,tetraspanin ,tetraspanin-enriched microdomain ,plasma membrane ,cell signaling ,exosome ,Cytology ,QH573-671 - Abstract
Tetraspanins, a superfamily of small integral membrane proteins, are characterized by four transmembrane domains and conserved protein motifs that are configured into a unique molecular topology and structure in the plasma membrane. They act as key organizers of the plasma membrane, orchestrating the formation of specialized microdomains called “tetraspanin-enriched microdomains (TEMs)” or “tetraspanin nanodomains” that are essential for mediating diverse biological processes. TSPAN8 is one of the earliest identified tetraspanin members. It is known to interact with a wide range of molecular partners in different cellular contexts and regulate diverse molecular and cellular events at the plasma membrane, including cell adhesion, migration, invasion, signal transduction, and exosome biogenesis. The functions of cell-surface TSPAN8 are governed by ER targeting, modifications at the Golgi apparatus and dynamic trafficking. Intriguingly, limited evidence shows that TSPAN8 can translocate to the nucleus to act as a transcriptional regulator. The transcription of TSPAN8 is tightly regulated and restricted to defined cell lineages, where it can serve as a molecular marker of stem/progenitor cells in certain normal tissues as well as tumors. Importantly, the oncogenic roles of TSPAN8 in tumor development and cancer metastasis have gained prominence in recent decades. Here, we comprehensively review the current knowledge on the molecular characteristics and regulatory mechanisms defining TSPAN8 functions, and discuss the potential and significance of TSPAN8 as a biomarker and therapeutic target across various epithelial cancers.
- Published
- 2024
- Full Text
- View/download PDF
17. Erratum to: Heinz Heinemann’s Legacy at ExxonMobil: An Illustrious Career in Industrial Catalysis
- Author
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Degnan, Jr., Thomas F. and Chen, Nai Y.
- Published
- 2009
- Full Text
- View/download PDF
18. Construction of a Real-Time Ship Trajectory Prediction Model Based on Ship Automatic Identification System Data
- Author
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Daping Xi, Yuhao Feng, Wenping Jiang, Nai Yang, Xini Hu, and Chuyuan Wang
- Subjects
AIS data ,river sinuosity ,trajectory clustering ,anastomosing river ,trajectory prediction ,Geography (General) ,G1-922 - Abstract
The extraction of ship behavior patterns from Automatic Identification System (AIS) data and the subsequent prediction of travel routes play crucial roles in mitigating the risk of ship accidents. This study focuses on the Wuhan section of the dendritic river system in the middle reaches of the Yangtze River and the partial reticulated river system in the northern part of the Zhejiang Province as its primary investigation areas. Considering the structure and attributes of AIS data, we introduce a novel algorithm known as the Combination of DBSCAN and DTW (CDDTW) to identify regional navigation characteristics of ships. Subsequently, we develop a real-time ship trajectory prediction model (RSTPM) to facilitate real-time ship trajectory predictions. Experimental tests on two distinct types of river sections are conducted to assess the model’s reliability. The results indicate that the RSTPM exhibits superior prediction accuracy when compared to conventional trajectory prediction models, achieving an approximate 20 m prediction accuracy for ship trajectories on inland waterways. This showcases the advancements made by this model.
- Published
- 2023
- Full Text
- View/download PDF
19. Impact of operating conditions on nitrogen removal using cyclic activated sludge technology (CAST)
- Author
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Zhao X Zhang, Ya Y Wang, Ming H Ren, Min Yan, Jian Yang, and Nai Y Gao
- Subjects
Environmental Engineering ,Denitrification ,Sewage ,Nitrogen ,Chemistry ,chemistry.chemical_element ,General Medicine ,Waste Disposal, Fluid ,Activated sludge ,Wastewater ,Environmental chemistry ,Sewage treatment ,Nitrification ,Nitrogen cycle ,Waste disposal - Abstract
In this study, the nitrogen removal performance of a municipal wastewater treatment plant that employs cyclic activated sludge technology (CAST) was evaluated. The impact of key operational conditions such as temperature, dissolved oxygen (DO) concentrations and operating modes were examined in parallel. During summer, when the operating temperature ranged from 27-30 degrees C, the NH(4)(+)-N and total nitrogen (TN) removal efficiencies were 51 +/- 7% and 42 +/- 7%, respectively, and simultaneous nitrification and denitrification (SND) was considered to be the major nitrogen removal mechanism. In contrast, at a low operating temperature of 10-15 degrees C, the DO concentration increased from 0.7 to 3.0 mg/L; however, the NH(4)(+)-N and TN removals were both inefficient due to poor biomass activities, which was demonstrated by a lower specific oxygen uptake rate (SOUR) of 1.2 mg O(2)/g SS. h (15 degrees C). Moreover, a 3h-mode for the CAST process was preferable during winter because the effluent wastewater quality was similar to that obtained when the 4h-mode was used. The extremely low organic loading was the primary reason for the poor bioactivity of the sludge in the CAST system, and this eventually led to deterioration of the nitrogen removal efficiencies.
- Published
- 2010
20. Function of Factice (Rubber Substitute) in Rubber Compounds
- Author
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Nai, Y., primary
- Published
- 2016
- Full Text
- View/download PDF
21. Retigabine protects the blood-brain barrier by regulating tight junctions between cerebral vascular endothelial cells in cerebral ischemia-reperfusion rats.
- Author
-
ZHAO, Y.-J., NAI, Y., LI, S.-Y., and ZHENG, Y.-H.
- Abstract
OBJECTIVE: To investigate the effect of retigabine on the blood-brain barrier permeability in rats with cerebral ischemia-reperfusion and its mechanism. MATERIALS AND METHODS: A total of 90 Sprague-Dawley (SD) rats were selected to prepare a rat model of focal cerebral ischemia- reperfusion. The blood flow changes were detected using a laser Doppler flow meter, the percentage of the cerebral infarction volume was measured by means of the triphenyl tetrazolium chloride (TTC) staining, the effect of retigabine on the permeability of the blood-brain barrier after cerebral ischemia-reperfusion was examined via Evans blue (EB) staining, and the state of tight junctions between endothelial cells was determined via the transmission electron microscopy (TEM) technique. Immunohistochemistry was used to detect the effects of retigabine on the distribution and expressions of tight junction-associated proteins in the cerebral ischemia-reperfusion blood-brain barrier. Western blotting was adopted to examine the changes in the expressions of related proteins in cerebral ischemia-reperfusion tissues. RESULTS: At 48 h and 96 h after cerebral ischemia-reperfusion, retigabine notably reduced the cerebral infarction volume of rats, and the tight junctions between microvascular endothelial cells in the ischemic area opened up, the permeability of the blood-brain barrier was remarkably increased, and the permeability of the blood-brain barrier was significantly reduced under the action of retigabine. The expressions of claudin-5, occludin, and ZO-1 in the blood-brain barrier of the ischemic brain tissue significantly declined, and retigabine notably increased the expressions of three proteins and their distributions along the microvessels. At 3 h, 24 h, 48 h, and 96 h after cerebral ischemia- reperfusion, the expressions of the MMP-2 protein and MMP-9 protein in the ischemic brain tissue were evidently increased, which were inhibited by retigabine. Moreover, the expressions of the PKCδ protein in the ischemic brain tissue were markedly increased, which were significantly inhibited by retigabine. CONCLUSIONS: The regulatory roles of retigabine in the distribution and expressions of claudin-5, occludin, and ZO-1 may be associated with the inhibition of the expressions of the MMP-2, MMP-9, and PKCδ proteins. [ABSTRACT FROM AUTHOR]
- Published
- 2018
22. Effects of Spatial Reference Frames, Map Dimensionality, and Navigation Modes on Spatial Orientation Efficiency
- Author
-
Hongyun Guo, Nai Yang, Zhong Wang, and Hao Fang
- Subjects
spatial reference frame ,navigation mode ,map dimensionality ,spatial orientation efficiency ,Geography (General) ,G1-922 - Abstract
How can the interactive mode of a map be optimized to facilitate efficient positioning and improve cognitive efficiency? This paper addresses this crucial aspect of map design. It explores the impact of spatial reference frames, map dimensionality, and navigation modes on spatial orientation efficiency, as well as their interactions, through empirical eye-movement experiments. The results demonstrate the following: (1) When using a 2D fixed map in an allocentric reference frame, participants exhibit a high correct rate, a low cognitive load, and a short reaction time. In contrast, when operating within an egocentric reference frame using a 2D rotating map, participants demonstrate a higher correct rate, a reduced cognitive load, and a quicker reaction time. (2) The simplicity of 2D maps, despite their reduced authenticity compared to 3D maps, diminishes users’ cognitive load and enhances positioning efficiency. (3) The fixed map aligns more closely with the cognitive habits of participants in the allocentric reference frame, while the rotating map corresponds better to the cognitive habits of participants in the egocentric reference frame, thereby improving their cognitive efficiency. This study offers insights that can inform the optimization design of spatial orientation efficiency.
- Published
- 2023
- Full Text
- View/download PDF
23. Sequential genome-wide CRISPR-Cas9 screens identify genes regulating cell-surface expression of tetraspanins
- Author
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Jicheng Yang, Fusheng Guo, Hui San Chin, Gao Bin Chen, Chow Hiang Ang, Qingsong Lin, Wanjin Hong, and Nai Yang Fu
- Subjects
CP: Cell biology ,Biology (General) ,QH301-705.5 - Abstract
Summary: Tetraspanins, a superfamily of membrane proteins, mediate diverse biological processes through tetraspanin-enriched microdomains in the plasma membrane. However, how their cell-surface presentation is controlled remains unclear. To identify the regulators of tetraspanin trafficking, we conduct sequential genome-wide loss-of-function CRISPR-Cas9 screens based on cell-surface expression of a tetraspanin member, TSPAN8. Several genes potentially involved in endoplasmic reticulum (ER) targeting, different biological processes in the Golgi apparatus, and protein trafficking are identified and functionally validated. Importantly, we find that biantennary N-glycans generated by MGAT1/2, but not more complex glycan structures, are important for cell-surface tetraspanin expression. Moreover, we unravel that SPPL3, a Golgi intramembrane-cleaving protease reported previously to act as a sheddase of multiple glycan-modifying enzymes, controls cell-surface tetraspanin expression through a mechanism associated with lacto-series glycolipid biosynthesis. Our study provides critical insights into the molecular regulation of cell-surface presentation of tetraspanins with implications for strategies to manipulate their functions, including cancer cell invasion.
- Published
- 2023
- Full Text
- View/download PDF
24. Personal Perspective of the Development of Para Selective ZSM-5 Catalysts
- Author
-
Nai Y. Chen
- Subjects
Chemistry ,General Chemical Engineering ,Xylene ,General Chemistry ,Molecular sieve ,Heterogeneous catalysis ,Industrial and Manufacturing Engineering ,Catalysis ,chemistry.chemical_compound ,Catalyst selectivity ,Organic chemistry ,ZSM-5 ,Zeolite ,Selectivity - Abstract
The evolution of para selective catalysis from a concept to a commercial process for the para selective synthesis of xylene took more than 17 years. While the mechanism of molecular selectivity was...
- Published
- 2001
25. Understanding Learning Intention Complexities in Lean Manufacturing Training for Innovation on the Production Floor
- Author
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Nai Yeen Gavin Lai, Wai Choong Foo, Chon Siong Tan, Myoung Sook Kang, Hooi Siang Kang, Kok Hoong Wong, Lih Jiun Yu, Xu Sun, and Nadia Mei Lin Tan
- Subjects
learning intention ,training ,lean manufacturing ,continuous improvement ,Management. Industrial management ,HD28-70 ,Business ,HF5001-6182 - Abstract
ABSTRACT: The Theory of Planned Behavior (TPB) is a useful framework that helps explain people’s behavior across a wide range of settings. The present study adopted the TPB to investigate factors that affect the complexity of the learning intention of workers involved with a lean manufacturing training initiative. Even though workers’ training has been consistently listed as a critical success factor for innovative improvement initiatives, very few studies explore direct workers’ learning intentions. This is particularly true within the area of lean manufacturing training. Hence, direct workers in an automotive parts manufacturing organization were invited to participate in this study, to which 204 workers voluntarily responded. The survey data was compiled and analyzed through stepwise regression to establish the effects of the different factors on learning intention in lean manufacturing training. It was determined from the empirical results that the participants’ attitude toward learning from lean manufacturing training and the perceived behavioral control factors positively affected the workers’ learning intention. Organization management could look into different measures and policies to stimulate better learning effects from training programs among the participants. Actions that could foster positive attitudes and confidence of workers towards lean training initiatives will be most helpful in enabling effective and innovative lean practices on the organization’s shop floors. The key theoretical and managerial implications, as well as the limitations of the study, are also discussed.
- Published
- 2022
- Full Text
- View/download PDF
26. DI-3-n-butylphthalide protects the blood brain barrier of cerebral infarction by activating the Nrf-2/HO-1 signaling pathway in mice.
- Author
-
ZHAO, Y.-J., NAI, Y., MA, Q.-S., SONG, D.-J., MA, Y.-B., ZHANG, L.-H., and MI, L.-X.
- Abstract
OBJECTIVE: The aim of this study was to explore whether Dl-3-n-butylphthalide (DBT) could protect blood-brain barrier (BBB) of mice with experimental cerebral infarction and the relevant mechanism. MATERIALS AND METHODS: Adult male CD-1 mice were selected as the study objects. The permanent middle cerebral artery occlusion (MCAO) model was prepared by Longa's modified suture-occluded method. The mice were randomly divided into 3 groups: the sham operation group (Sham group), the cerebral infarction model group (CI group) and the DBT (120 mg/kg) intervention group (DBT group). Neurologic function deficits were evaluated by Longa's modified scoring method after 24 h of permanent MCAO. The wet and dry weight method was used for measuring water content in brain tissues. 2% 2,3,5-triphenyltetrazolium chloride (TTC) staining method was applied to determine the volume of cerebral infarction. Changes in the protein and messenger ribonucleic acid (mRNA) expression levels of matrix metallopeptidase 9 (MMP-9), claudin-5, vascular endothelial growth factor (VEGF), glial fibrillary acidic protein (GFAP), NF-E2 related factor 2 (Nrf-2) and heme oxygenase 1 (HO-1) in ischemic brain tissues were detected using immunohistochemistry, Western blotting and quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). Ultrastructure changes in BBBs were observed under an electron microscope. RESULTS: DBT improved the neurologic function deficits of mice and reduced the infarction volume of mice with cerebral infarction. DBT alleviated edema and decreased the permeability of BBBs of mice with cerebral infarction. DBT down-regulated the expression of MMP-9 and up-regulated the expression of claudin-5 in brain tissues of mice with cerebral infarction. DBT increased the expressions of VEGF and GFAP. DBT improved the ultrastructure in capillary endothelial cells of BBBs and increased the expressions of Nrf-2 and HO-1. CONCLUSIONS: DBT may protect BBB by activating the Nrf-2/HO-1 signaling pathway, thus achieving its protective effect on the brain. [ABSTRACT FROM AUTHOR]
- Published
- 2018
27. Conversion of light naphthas over sulfided nickel erionite
- Author
-
Roland H. Heck and Nai Y. Chen
- Subjects
Chemistry ,General Chemical Engineering ,Butane ,General Chemistry ,Erionite ,Industrial and Manufacturing Engineering ,Catalysis ,chemistry.chemical_compound ,Catalytic reforming ,Propane ,Organic chemistry ,Octane rating ,Naphtha ,Octane - Abstract
A natural erionite ore has been exchanged with ammonium and nickel salts to yield a Ni/H erionite catalyst that is active and stable for selectively hydrocracking only the n-paraffins from light straight-run naphthas. The primary product is a C[sup 5+] liquid that is 15-20 octane numbers higher than the feed and a propane- and butane-rich gas by-product. Results from a 110-day pilot plant run demonstrated that a catalyst life of more than 1 year should be possible. Naphthenes, aromatics, and isoparaffins are neither produced nor consumed in this process, resulting in a C[sup 5+] liquid product that is lower in benzene and total aromatics than attainable by catalytic reforming of these feeds. Although no further work is planned with this catalyst, a naphtha-upgrading process based on shape-selective zeolitic hydrocracking could provide an attractive alternative to catalytic reforming or isomerization for these hard to upgrade naphthas. It should be particularly attractive in areas where the by-product propane and butane have good value.
- Published
- 1993
28. ChemInform Abstract: Hydrocracking of n-Butane and n-Heptane Over a Sulfided Nickel Erionite Catalyst
- Author
-
Nai Y. Chen and Roland H. Heck
- Subjects
chemistry.chemical_compound ,Cracking ,chemistry ,Propane ,Yield (chemistry) ,mental disorders ,Physical chemistry ,Dehydrogenation ,Butane ,General Medicine ,Activation energy ,Product distribution ,Catalysis - Abstract
A sulfided Ni/H-erionite catalyst was prepared from the natural mineral, and its catalytic characteristics for hydrocracking n-alkanes were studied. Because of its shape selectivity toward straight chain hydrocarbons, branched products were largely absent and the major cracked product was propane. The observed product distribution could not be explained by simple primary cracking of the feed molecule or by secondary cracking or recombination of the primary products. It is proposed that the feed molecule participated in a set of reactions, including hydrogenation, dehydrogenation, hydrogen transfer, oligomerization and cracking. These reactions are also needed to explain the yield of less than two moles of product from each mole of feed converted. A set of six first order differential equations representing the proposed molecular transformations is shown to fit the product distribution data for n-butane very well. A fit of the n-heptane data was not attempted; however, it is proposed that the mechanism is analogous to that proposed for n-butane. The rate of cracking of n-butane is first order in n-butane concentration, while the rate of n-heptane cracking appeared to follow half order kinetics. For n-butane cracking, the apparent activation energy of all the important reactions are roughly equal, resulting in a product distribution which is nearly independent of temperature. For n-heptane, a larger difference between the apparent activation energy of n-heptane cracking and secondary cracking of its primary products, lead to a temperature dependence in product selectivity.
- Published
- 2010
29. Hydrocracking of n-butane and n-heptane over a sulfided nickel erionite catalyst
- Author
-
Roland H. Heck and Nai Y. Chen
- Subjects
Process Chemistry and Technology ,Inorganic chemistry ,Butane ,Activation energy ,Catalysis ,Product distribution ,chemistry.chemical_compound ,Cracking ,chemistry ,Propane ,Yield (chemistry) ,mental disorders ,Dehydrogenation - Abstract
A sulfided Ni/H-erionite catalyst was prepared from the natural mineral, and its catalytic characteristics for hydrocracking n-alkanes were studied. Because of its shape selectivity toward straight chain hydrocarbons, branched products were largely absent and the major cracked product was propane. The observed product distribution could not be explained by simple primary cracking of the feed molecule or by secondary cracking or recombination of the primary products. It is proposed that the feed molecule participated in a set of reactions, including hydrogenation, dehydrogenation, hydrogen transfer, oligomerization and cracking. These reactions are also needed to explain the yield of less than two moles of product from each mole of feed converted. A set of six first order differential equations representing the proposed molecular transformations is shown to fit the product distribution data for n-butane very well. A fit of the n-heptane data was not attempted; however, it is proposed that the mechanism is analogous to that proposed for n-butane. The rate of cracking of n-butane is first order in n-butane concentration, while the rate of n-heptane cracking appeared to follow half order kinetics. For n-butane cracking, the apparent activation energy of all the important reactions are roughly equal, resulting in a product distribution which is nearly independent of temperature. For n-heptane, a larger difference between the apparent activation energy of n-heptane cracking and secondary cracking of its primary products, lead to a temperature dependence in product selectivity.
- Published
- 1992
30. Recent Advances in Shape-Selective Catalysis and Its Industrial Applications
- Author
-
Nai Y. Chen
- Subjects
Engineering ,business.industry ,Nanotechnology ,business ,Catalysis - Published
- 1999
31. Early diagnosis of tuberculous meningitis by an indirect ELISA protocol based on the detection of the antigen ESAT-6 in cerebrospinal fluid
- Author
-
Song, F., primary, Sun, X., additional, Wang, X., additional, Nai, Y., additional, and Liu, Z., additional
- Published
- 2013
- Full Text
- View/download PDF
32. Physiological Functions of Mcl-1: Insights From Genetic Mouse Models
- Author
-
Hui San Chin and Nai Yang Fu
- Subjects
Bcl-2 ,Mcl-1 ,apoptosis ,cell death ,mitochondria ,genetic mouse model ,Biology (General) ,QH301-705.5 - Abstract
The ability to regulate the survival and death of a cell is paramount throughout the lifespan of a multicellular organism. Apoptosis, a main physiological form of programmed cell death, is regulated by the Bcl-2 family proteins that are either pro-apoptotic or pro-survival. The in vivo functions of distinct Bcl-2 family members are largely unmasked by genetically engineered murine models. Mcl-1 is one of the two Bcl-2 like pro-survival genes whose germline deletion causes embryonic lethality in mice. Its requisite for the survival of a broad range of cell types has been further unraveled by using conditional and inducible deletion murine model systems in different tissues or cell lineages and at distinct developmental stages. Moreover, genetic mouse cancer models have also demonstrated that Mcl-1 is essential for the survival of multiple tumor types. The MCL-1 locus is commonly amplified across various cancer types in humans. Small molecule inhibitors with high affinity and specificity to human MCL-1 have been developed and explored for the treatment of certain cancers. To facilitate the pre-clinical studies of MCL-1 in cancer and other diseases, transgenic mouse models over-expressing human MCL-1 as well as humanized MCL-1 mouse models have been recently engineered. This review discusses the current advances in understanding the physiological roles of Mcl-1 based on studies using genetic murine models and its critical implications in pathology and treatment of human diseases.
- Published
- 2021
- Full Text
- View/download PDF
33. Impact of operating conditions on nitrogen removal using cyclic activated sludge technology (CAST)
- Author
-
Wang, Ya Y., primary, Zhang, Zhao X., additional, Yan, Min, additional, Gao, Nai Y., additional, Yang, Jian, additional, and Ren, Ming H., additional
- Published
- 2010
- Full Text
- View/download PDF
34. Fabrication of Gelatin Nanofibers by Electrospinning—Mixture of Gelatin and Polyvinyl Alcohol
- Author
-
Hsiu Yu Chi, Nai Yun Chang, Chuan Li, Vincent Chan, Jang Hsin Hsieh, Ya-Hui Tsai, and Tingchao Lin
- Subjects
gelatin ,polyvinyl alcohol ,electrospinning ,spin coating ,Fourier-transform infrared spectrometer ,water contact angle ,Organic chemistry ,QD241-441 - Abstract
Gelatin, one of the most abundant, naturally derived biomacromolecules from collagen, is widely applicable in food additives, cosmetic ingredients, drug formulation, and wound dressing based on their non-toxicity and biodegradability. In parallel, polyvinyl alcohol (PVA), a synthetic polymer, has been commonly applied as a thickening agent for coating processes in aqueous systems and a major component in healthcare products for cartilage replacements, eye lubrication, and contact lenses. In this study, a new type of mixed hydrogel nanofiber was fabricated from gelatin and polyvinyl alcohol by electrospinning under a feasible range of polymer compositions. To determine the optimal composition of gelatin and polyvinyl alcohol in nanofiber fabrication, several key physicochemical properties of mixed polymer solutions such as viscosity, surface tension, pH, and electrical conductance were thoroughly characterized by a viscometer, surface tensiometer, water analyzer, and carbon electron probe. Moreover, the molecular structures of polymeric chains within mixed hydrogel nanofibers were investigated with Fourier-transform infrared spectroscopy. The morphologies and surface elemental compositions of the mixed hydrogel nanofibers were examined by the scanning electron microscope and energy-dispersive X-ray spectroscopy, respectively. The measurement of water contact angles was performed for measuring the hydrophilicity of nanofiber surfaces. Most importantly, the potential cytotoxicity of the electrospun nanofibers was evaluated by the in vitro culture of 3T3 fibroblasts. Through our extensive study, it was found that a PVA-rich solution (a volumetric ratio of gelatin/polyvinyl alcohol −2 poise) and slightly lower surface tension (~35.12–~32.68 mN/m2) of the mixed polymer solution. The regression on the viscosity data also found a good fit by the Lederer–Rougier’s model for a binary mixture. For the hydrophilicity of nanofibers, the numerical analysis estimates that the value of interfacial energy for the water contact on nanofibers is around ~−0.028 to ~−0.059 J/m2.
- Published
- 2022
- Full Text
- View/download PDF
35. Acute cervical cord injury complicating Klippel-Feil deformity and mimicking ‘man in the barrel’ syndrome
- Author
-
Nai Y Lai and Grant Purdie
- Subjects
medicine.medical_specialty ,Weakness ,business.industry ,Barrel (horology) ,Dysostosis ,Klippel–Feil syndrome ,General Medicine ,Anatomy ,medicine.disease ,Surgery ,Central nervous system disease ,Neurology ,Physiology (medical) ,medicine ,Deformity ,Neurology (clinical) ,medicine.symptom ,business ,Spinal cord injury ,Collapse (medical) - Abstract
This case illustrates the need to recognize a high cervical cord injury as a cause for bi-brachial weakness with intact bi-crural power, a pattern termed aptly by Sage as 'man in the barrel' syndrome. The patient who had an undiagnosed Klippel-Feil deformity had incurred his cervical injury after a collapse.
- Published
- 1998
36. Personal Perspective of the Development of Para Selective ZSM-5 Catalysts
- Author
-
Chen, Nai Y., primary
- Published
- 2001
- Full Text
- View/download PDF
37. Correction: Yang et al. Influence of Relief Degree of Land Surface on Street Network Complexity in China. ISPRS Int. J. Geo-Inf. 2021, 10, 705
- Author
-
Nai Yang, Le Jiang, Yi Chao, Yang Li, and Pengcheng Liu
- Subjects
n/a ,Geography (General) ,G1-922 - Abstract
In the original publication [...]
- Published
- 2022
- Full Text
- View/download PDF
38. Acute cervical cord injury complicating Klippel-Feil deformity and mimicking ‘man in the barrel’ syndrome
- Author
-
Lai, Nai Y, primary and Purdie, Grant, additional
- Published
- 1998
- Full Text
- View/download PDF
39. “Nanging”: another cause of nitrous oxide neurotoxicity
- Author
-
Lai, Nai Y, primary, Silbert, Peter L, additional, Erber, Wendy N, additional, and Rijks, Cornelius J, additional
- Published
- 1997
- Full Text
- View/download PDF
40. Influence of Relief Degree of Land Surface on Street Network Complexity in China
- Author
-
Nai Yang, Le Jiang, Yi Chao, Yang Li, and Pengcheng Liu
- Subjects
street network complexity ,OSMnx ,street orientations ,China’s topography ,Geography (General) ,G1-922 - Abstract
The relief degree of land surface (RDLS) was often calculated to describe the topographic features of a region. It is a significant factor in designing urban street networks. However, existing studies do not clarify how RDLS affects the distribution of urban street networks. We used a Python package named OSMnx to extract the street networks of different cities in China. The street complexity metrics information (i.e., street grain, connectedness, circuity, and street network orientation entropy) were obtained and analyzed statistically. The results indicate that street network exhibits more complexity in regions with high RDLS. Further analysis of the correlation between RDLS and street network complexity metrics indicates that RDLS presents the highest correlation with street network circuity; that is, when RDLS is higher, the routes of an urban street network is more tortuous, and the additional travel costs for urban residents is higher. This study enriches and expands research on street networks in China, providing a reference value for urban street network planning.
- Published
- 2021
- Full Text
- View/download PDF
41. Conversion of light naphthas over sulfided nickel erionite
- Author
-
Heck, Roland H., primary and Chen, Nai Y., additional
- Published
- 1993
- Full Text
- View/download PDF
42. Change of the growth hormone-insulin-like growth factor-I axis in patients with gastrointestinal cancer: related to tumour type and nutritional status.
- Author
-
Huang Q, Nai Y, Jiang Z, and Li J
- Published
- 2005
- Full Text
- View/download PDF
43. MOAP-1 Mediates Fas-Induced Apoptosis in Liver by Facilitating tBid Recruitment to Mitochondria
- Author
-
Chong Teik Tan, Qi-Ling Zhou, Yu-Chin Su, Nai Yang Fu, Hao-Chun Chang, Ran N. Tao, Sunil K. Sukumaran, Shairaz Baksh, Yee-Joo Tan, Kanaga Sabapathy, Chun-Dong Yu, and Victor C. Yu
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Fas apoptotic signaling regulates diverse physiological processes. Acute activation of Fas signaling triggers massive apoptosis in liver. Upon Fas receptor stimulation, the BH3-only protein Bid is cleaved into the active form, tBid. Subsequent tBid recruitment to mitochondria, which is facilitated by its receptor MTCH2 at the outer mitochondrial membrane (OMM), is a critical step for commitment to apoptosis via the effector proteins Bax or Bak. MOAP-1 is a Bax-binding protein enriched at the OMM. Here, we show that MOAP-1-deficient mice are resistant to Fas-induced hepatocellular apoptosis and lethality. In the absence of MOAP-1, mitochondrial accumulation of tBid is markedly impaired. MOAP-1 binds to MTCH2, and this interaction appears necessary for MTCH2 to engage tBid. These findings reveal a role for MOAP-1 in Fas signaling in the liver by promoting MTCH2-mediated tBid recruitment to mitochondria.
- Published
- 2016
- Full Text
- View/download PDF
44. Essential role for a novel population of binucleated mammary epithelial cells in lactation
- Author
-
Anne C. Rios, Nai Yang Fu, Paul R. Jamieson, Bhupinder Pal, Lachlan Whitehead, Kevin R. Nicholas, Geoffrey J. Lindeman, and Jane E. Visvader
- Subjects
Science - Abstract
The main function of the mammary gland is to produce milk to sustain offspring. Here, the authors show that secretory alveolar cells in the lactating gland in several species are binucleated, which increases milk production, and that binucleation is regulated by Aurora kinase-A and Polo-like kinase-1.
- Published
- 2016
- Full Text
- View/download PDF
45. Open Set Lattices of Subspaces of Spectrum Spaces
- Author
-
Nai Y.T. and Zhao D.
- Subjects
prime element ,S-semiprime element ,m-semiprime element ,hull kernel topology ,pure element ,mp-multiplicative lattice ,Mathematics ,QA1-939 - Abstract
We take a unified approach to study the open set lattices of various subspaces of the spectrum of a multiplicative lattice L. The main aim is to establish the order isomorphism between the open set lattice of the respective subspace and a sub-poset of L. The motivating result is the well known fact that the topology of the spectrum of a commutative ring R with identity is isomorphic to the lattice of all radical ideals of R. The main results are as follows: (i) for a given nonempty set S of prime elements of a multiplicative lattice L, we define the S-semiprime elements and prove that the open set lattice of the subspace S of Spec(L) is isomorphic to the lattice of all S-semiprime elements of L; (ii) if L is a continuous lattice, then the open set lattice of the prime spectrum of L is isomorphic to the lattice of all m-semiprime elements of L; (iii) we define the pure elements, a generalization of the notion of pure ideals in a multiplicative lattice and prove that for certain types of multiplicative lattices, the sub-poset of pure elements of L is isomorphic to the open set lattice of the subspace Max(L) consisting of all maximal elements of L.
- Published
- 2015
- Full Text
- View/download PDF
46. Transplanted Gonadotropin-Releasing Hormone Neurons Promote Pulsatile Luteinizing Hormone Secretion in Congenitally Hypogonadal (hpg) Male Mice.
- Author
-
Kokoris, George J., Lam, Nai Y., Ferin, Michel, Silverman, Ann-Judith, and Gibson, Marie J.
- Published
- 1988
- Full Text
- View/download PDF
47. Selective Hydrocracking of n-Paraffins in Jet Fuels
- Author
-
William E. Garwood and Nai Y. Chen
- Subjects
Cracking ,Chemical engineering ,Chemistry ,General Engineering ,General Medicine ,Jet fuel - Published
- 1978
48. TMA-offretite. Relationship between structural and catalytic properties
- Author
-
W.E. Garwood, G.T. Kokotailo, Nai Y. Chen, and J.L. Schlenker
- Subjects
Diffraction ,High intensity ,Inorganic chemistry ,Stacking ,chemistry.chemical_element ,Ring (chemistry) ,Oxygen ,Catalysis ,Crystallography ,chemistry ,Perpendicular ,Physical and Theoretical Chemistry ,Zeolite - Abstract
Previous studies reported that synthetic TMA-offretite is an open large-pore (12-membered oxygen ring opening) zeolite. Closer reexamination of the odd l lines using high intensity X-ray diffraction and additional catalytic diagnostic studies suggest that some of the open 12-ring channels in the synthetic sample may be blocked randomly by single stacking faults, such that the only other openings are 8-membered oxygen ring openings perpendicular to the large channels. These structural characteristics could explain the observed shape selective catalytic dewaxing activity and the preponderance of straight-chain cracked products.
- Published
- 1984
49. Hydrogasification of heavy oils
- Author
-
Nai Y. Chen and Dennis E. Walsh
- Subjects
Hydrogen ,Chemistry ,business.industry ,Fossil fuel ,General Engineering ,Analytical chemistry ,chemistry.chemical_element ,General Medicine ,Partial pressure ,chemistry.chemical_compound ,Residue (chemistry) ,Hydrogen pressure ,Organic chemistry ,Petroleum ,Residual carbon ,business ,Energy source - Abstract
Thermal hydrogasification of heavy petroleum oils was investigated under conditions of short reaction time (0.5-15 s products residence time) and varied heating rates to elevated temperatures (50-850 /sup 0/C/s to > 550 /sup 0/C). Total pressures and hydrogen partial pressures up to 1500 psig were examined. Products consisted of a residual carbon fraction, light gases (primarily CH/sub 4/), and BTX. Carbon residue was minimized by increasing hydrogen pressure up to about 700 psig, final reaction temperature up to about 700 /sup 0/C, and the oil reaction time up to about 8 s. The amount of carbon residue produced is a function of the C/H ratio of the charge. For San Ardo crude, the highest carbon conversion to light products was 82 wt % corresponding to 18 wt % carbon as residue, 67 wt % carbo as gas, and 15 wt % as BTX. Over a wide range of conversion, gas and BTX were produced in fairly fixed proportions ( about 82% gas, 18% BTX).
- Published
- 1983
50. Transplanted Gonadotropin-Releasing Hormone Neurons Promote Pulsatile Luteinizing Hormone Secretion in Congenitally Hypogonadal (hpg) Male Mice
- Author
-
Ann-Judith Silverman, Michel Ferin, Nai Y. Lam, Marie J. Gibson, and George J. Kokoris
- Subjects
Male ,endocrine system ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Radioimmunoassay ,Gonadotropin-releasing hormone ,Peptide hormone ,Biology ,Mice ,Cellular and Molecular Neuroscience ,Endocrinology ,Internal medicine ,medicine ,Animals ,Neurons ,Luteinizing hormone secretion ,Endocrine and Autonomic Systems ,Hypogonadism ,Luteinizing Hormone ,Immunohistochemistry ,Transplantation ,Preoptic area ,Median eminence ,Luteinizing hormone ,Orchiectomy ,Pituitary Hormone-Releasing Hormones ,hormones, hormone substitutes, and hormone antagonists ,Hormone - Abstract
Congenitally hypogonadal (hpg) male mice are unable to synthesize biologically active gonadotropin-releasing hormone (GnRH). Implantation of normal fetal preoptic area tissue containing GnRH neurons into the third ventricle of adult hpg males significantly elevates pituitary levels of luteinizing hormone (LH) and corrects their hypogonadism. In all responding animals, immunoreactive GnRH neurons within the transplant innervate the median eminence of the host. To assess whether gonadal recovery in hpg hosts results from pulsatile secretion of GnRH from grafted neurons, we compared the pattern of variation in plasma LH levels in 19 hpg graft recipients with testicular growth to that of 10 normal adult mice. All animals were castrated prior to receiving an indwelling catheter in the jugular vein. Sequential blood samples were collected (t = 10 min) and assayed for LH. Pulsatile LH secretion was seen in 11 of 19 hpg hosts and in all control mice. While there was great variability between individual animals, measures of baseline LH, LH pulse amplitude and duration, interpulse interval, and LH pulse frequency revealed no difference between hpg graft recipients and normal castrates in their LH pulse pattern. Immunocytochemical analysis of the brain in hpg hosts suggested no correlation between any parameter of pulse activity and individual differences in GnRH cell number or GnRH fiber outgrowth into the median eminence. Sources of variation in LH secretion among graft recipients, and between hpg hosts and normal mice, are discussed. We suggest that transplanted GnRH neurons are capable of integration into a GnRH 'pulse generator' which can support a near-normal pattern of pulsatile LH secretion, leading to testicular growth and steroid production.
- Published
- 1988
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