| 1081. |
- Sun, Jia, et al.
(författare)
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Cathelicidins positively regulate pancreatic beta-cell functions
- 2016
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Ingår i: The FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 30:2, s. 884-894
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Tidskriftsartikel (refereegranskat)abstract
- Cathelicidins are pleiotropic antimicrobial peptides largely described for innate antimicrobial defenses and, more recently, immunomodulation. They are shown to modulate a variety of immune or nonimmune host cell responses. However, how cathelicidins are expressed by beta cells and modulate beta-cell functions under steady-state or proinflammatory conditions are unknown. We find that cathelicidin-related antimicrobial peptide (CRAMP) is constitutively expressed by rat insulinoma b-cell clone INS-1 832/13. CRAMP expression is inducible by butyrate or phenylbutyric acid and its secretion triggered upon inflammatory challenges by IL-1 beta or LPS. CRAMP promotes b-cell survival in vitro via the epidermal growth factor receptor (EGFR) and by modulating expression of antiapoptotic Bcl-2 family proteins: p-Bad, Bcl-2, and Bcl-xL. Also via EGFR, CRAMP stimulates glucose-stimulated insulin secretion ex vivo by rat islets. A similar effect is observed in diabetes-prone nonobese diabetic (NOD) mice. Additional investigation under inflammatory conditions reveals that CRAMP modulates inflammatory responses and beta-cell apoptosis, asmeasured by prostaglandin E2 production, cyclooxygenases (COXs), and caspase activation. Finally, CRAMP-deficient cnlp(-/-) mice exhibit defective insulin secretion, and administration of CRAMP to prediabetic NOD mice improves blood glucose clearance upon glucose challenge. Our finding suggests that cathelicidins positively regulate beta-cell functions and may be potentially used for intervening b-cell dysfunction-associated diseases.
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| 1082. |
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| 1083. |
- Sun, Jie, et al.
(författare)
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Frequency mixing and phase detection functionalities of three-terminal ballistic junctions
- 2007
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 18:19
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Tidskriftsartikel (refereegranskat)abstract
- Three-terminal ballistic junctions (TBJs) are fabricated from a high-mobility InP/In0.75Ga0.25As heterostructure by electron-beam lithography. The voltage output from the central branch is measured as a function of the voltages applied to the left and right branches of the TBJs. The measurements show that the TBJs possess an intrinsic nonlinearity. Based on this nonlinearity, a novel room-temperature functional frequency mixer and phase detector are realized. The TBJ frequency mixer and phase detector are expected to have advantages over traditional circuits in terms of simple structure, small size and high speed, and can be used as a new type of building block in nanoelectronics.
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| 1084. |
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| 1085. |
- Sun, Jie, 1977, et al.
(författare)
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Insights into the Mechanism for Vertical Graphene Growth by Plasma-Enhanced Chemical Vapor Deposition
- 2022
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Ingår i: Acs Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:5, s. 7152-7160
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Tidskriftsartikel (refereegranskat)abstract
- Vertically oriented graphene (VG) has attracted attention for years, but the growth mechanism is still not fully revealed. The electric field may play a role, but the direct evidence and exactly what role it plays remains unclear. Here, we conduct a systematic study and find that in plasma-enhanced chemical vapor deposition, the VG growth preferably occurs at spots where the local field is stronger, for example, at GaN nanowire tips. On almost round-shaped nanoparticles, instead of being perpendicular to the substrate, the VG grows along the field direction, that is, perpendicular to the particles' local surfaces. Even more convincingly, the sheath field is screened to different degrees, and a direct correlation between the field strength and the VG growth is observed. Numerical calculation suggests that during the growth, the field helps accumulate charges on graphene, which eventually changes the cohesive graphene layers into separate three-dimensional VG flakes. Furthermore, the field helps attract charged precursors to places sticking out from the substrate and makes them even sharper and turn into VG. Finally, we demonstrate that the VG-covered nanoparticles are benign to human blood leukocytes and could be considered for drug delivery. Our research may serve as a starting point for further vertical two-dimensional material growth mechanism studies.
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| 1086. |
- Sun, Jie, et al.
(författare)
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Novel nanoelectronic device applications based on the nonlinearity of three-terminal ballistic junctions
- 2007
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Ingår i: Physics of Semiconductors, Pts A and B. - : AIP. - 0094-243X .- 1551-7616. ; 893, s. 1471-1472
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Konferensbidrag (refereegranskat)abstract
- Nanometer-scale electron devices containing three-terminal ballistic junctions are fabricated by electron-beam lithography on InP/InGaAs two-dimensional electron gas materials. Based on the intrinsic nonlinearity of the devices, frequency mixer, phase detector and RS flip-flop memory functioning at room temperature are successfully achieved. The devices have simple structure layout and small size, and are expected to function at high speed.
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| 1087. |
- Sun, J, et al.
(författare)
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Transmission and exposure of kitchen particles : A case study in an apartment
- 2020
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Ingår i: Indoor + Built Environment. - : SAGE Publications Ltd. - 1420-326X .- 1423-0070.
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Tidskriftsartikel (refereegranskat)abstract
- Particles emitted from the kitchen have been proven as one of the major indoor particulate pollutants which could pose serious risk on human health. Thus, it is critical to study the migration of kitchen particles and the impact of kitchen particles on non-kitchen zones. Since Chinese domestic kitchens are equipped with exhaust hoods, the capture efficiency of an exhaust hood in real residence was first measured. The capture efficiency was about 48% with the air flow rate of 0.125 m3/s. Second, the relative occupant exposure was calculated to quantify migration characteristics of kitchen particles under different ventilation models. Results show that the meteorological environment had little effect on migration by infiltration but significant by natural ventilation. In the dwelling layout of this study, relative occupant exposures showed an upward trend in windward and a downward trend in leeward. When the wind direction was 225°, wind speed had the greatest impact on particle migration. Finally, the effect of the opening and closing situation of kitchen door on air quality was analysed. Results show that closing the kitchen door increased the exposure in the kitchen by 30–58%, while the exposure in the study dropped to 43% of the door open status.
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| 1088. |
- Sun, M. B., et al.
(författare)
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Assessment and modification of sub-cell-fix method for re-initialization of level-set distance function
- 2010
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Ingår i: International Journal for Numerical Methods in Fluids. - : Wiley. - 1097-0363 .- 0271-2091. ; 62:2, s. 211-236
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Tidskriftsartikel (refereegranskat)abstract
- Sub-cell-fix re-initialization method was proposed by Russo and Smereka (J. Comput. Phys. 2000; 163: 51-67) as a modification to the re-distancing, algorithm Of Sussman et al. (J. Comput. Phys. 1994; 114: 146-159) that determines the distance function from an interface known as the zero level-set. The principal goal of sub-cell-fix method is to compute the distance function of the cells adjacent to the zero level-set without disturbing the original zero level-set. Following the original work of Russo and Smereka, several improved sub-cell-fix schemes were reported in the literature. In this paper, we show that in certain situations almost all the previous sub-cell-fix schemes can disturb the zero level-set, and the accuracy would not improve when the CFL numbers are decreased. Based on the scheme of Hartmann et al. (J Comput. Phys. 2008; 227:6821-6845), we propose all improved sub-cell-fix scheme that can significantly increase the accuracy of sub-cell-fix method on problems that are challenging. The scheme makes use of a combination of the points adjacent to zero level-set surfaces and preserves the interface in a second-order accuracy. The new sub-cell-fix scheme is capable of handling large local Curvature, and as a result it demonstrates satisfactory performance on several challenging test cases. Limitations of the schemes on highly stretched grids are illustrated. Copyright (C) 2009 John Wiley & Sons, Ltd.
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| 1089. |
- Sun, M. D., et al.
(författare)
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Fine structure in the alpha decay of U-223
- 2020
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Ingår i: Physics Letters B. - : ELSEVIER. - 0370-2693 .- 1873-2445. ; 800
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Tidskriftsartikel (refereegranskat)abstract
- Fine structure in the alpha decay of U-223 was observed in the fusion-evaporation reaction Re-187(Ar-40, p3n) by using fast digital pulse processing technique. Two alpha-decay branches of U-223 feeding the ground state and 244 keV excited state of Th-219 were identified by establishing the decay chain U-223 (alpha(1)) under right arrow Th-219 (alpha(2)) under right arrow Ra-215 (alpha(3)) under right arrow Rn-211. The alpha-particle energy for the ground-state to ground-state transition of U-223 was determined to be 8993(17) keV, 213 keV higher than the previous value, the half-life was updated to be 62(-10)(+14) mu s. Evolution of nuclear structure for N = 131 even-Z isotones from Po to U was discussed in the frameworks of nuclear mass and reduced alpha-decay width, a weakening octupole deformation in the ground state of U-223 relative to its lighter isotones Ra-219 and Th-221 was suggested.
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| 1090. |
- Sun, Q., et al.
(författare)
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A Comprehensive Review of Smart Energy Meters in Intelligent Energy Networks
- 2016
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Ingår i: IEEE Internet of Things Journal. - 2327-4662. ; 3:4, s. 464-479
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Tidskriftsartikel (refereegranskat)abstract
- The significant increase in energy consumption and the rapid development of renewable energy, such as solar power and wind power, have brought huge challenges to energy security and the environment, which, in the meantime, stimulate the development of energy networks toward a more intelligent direction. Smart meters are the most fundamental components in the intelligent energy networks (IENs). In addition to measuring energy flows, smart energy meters can exchange the information on energy consumption and the status of energy networks between utility companies and consumers. Furthermore, smart energy meters can also be used to monitor and control home appliances and other devices according to the individual consumer's instruction. This paper systematically reviews the development and deployment of smart energy meters, including smart electricity meters, smart heat meters, and smart gas meters. By examining various functions and applications of smart energy meters, as well as associated benefits and costs, this paper provides insights and guidelines regarding the future development of smart meters.
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