| 1. |
- Jiang, Tao, et al.
(författare)
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Investigation of DC-Biased Optical OFDM With Precoding Matrix for Visible Light Communications : Theory, Simulations, and Experiments
- 2018
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Ingår i: IEEE Photonics Journal. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1943-0655. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Orthogonal frequency-division-multiplexing (OFDM) technology is widely used in visible light communication (VLC) to achieve high data rate transmission. However, the traditional direct-current (DC)-biased optical OFDM (DCO-OFDM) VLC systems suffer from the high peak-to-average power ratio (PAPR) which causes signal clipping distortion, and, thus, performance degradation. Furthermore, severe high-frequency fading due to the limited system bandwidth results in poor bit error rate (BER) performance. Precoding matrix (PM) techniques have been proposed to enhance the performance of VLC OFDM transmission, but a little or no work has been carried out in investigating the theory of PM used in OFDM VLC systems. In this paper, we aim to reveal the theory of PM-DCO-OFDM for a VLC system. To figure out the intrinsic laws of a PM method, we investigate the principles of PAPR reduction, clipping distortion optimization, and signal-to-noise ratio (SNR) distribution equalization. Based on the analysis of PAPR, we theoretically proved the simplicity of PM as a method to reduce the possibility of high PAPR by improving the autocorrelation performance of input symbols. The clipping distortion could be improved due to the reduction of high PAPR. Moreover, the relatively uniform SNR distribution can be achieved by PM through equalizing the clipping and channel noise, which is beneficial to improve the BER performance in high-frequency constrained systems. However, the PM method used in a DCO-OFDM VLC system should consider the transmitting power, modulation format, and transmission distance as a whole to achieve the transmission performance improvement. The simulation results demonstrate the complementary cumulative distribution function of PAPR can be reduced similar to 3 dB, while the performance of clipping distortion power and clipping error probability are significantly improved. Furthermore, experiment is carried out with results showing that the PM method can improve the BER performance in the case that VLC OFDM transmission has enough transmitting power, but with the low transmitting power, the PM also can damage the BER performance. The simulation and experiment results are consistent with our theoretical analysis.
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| 2. |
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| 3. |
- Feng, Zhenhua, et al.
(författare)
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Digital Domain Power Division Multiplexing DDO-OFDM Transmission with Successive Interference Cancellation
- 2016
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Ingår i: 2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO). - Washington, D.C. : IEEE conference proceedings.
-
Konferensbidrag (refereegranskat)abstract
- Two independent 2.5-Gb/s DDO-OFDM signals are simultaneously transmitted over 25km SMF using digital domain power division multiplexing and successive interference cancellation. With optimized power division ratio and enhanced SD-FEC, the spectral efficiency can be doubled.
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| 4. |
- Feng, Zhenhua, et al.
(författare)
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Multicore-Fiber-Enabled WSDM Optical Access Network With Centralized Carrier Delivery and RSOA-Based Adaptive Modulation
- 2015
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Ingår i: IEEE PHOTONICS JOURNAL. - : Institute of Electrical and Electronics Engineers (IEEE). - 1943-0655. ; 7:4
-
Tidskriftsartikel (refereegranskat)abstract
- We proposed and experimentally demonstrated a wavelength-space division multiplexing (WSDM) optical access network architecture with centralized optical carrier delivery utilizing multicore fibers (MCFs) and adaptive modulation based on reflective semiconductor amplifier (RSOA). In our experiment, five of the outer cores are used for undirectional downstream (DS) transmission only, whereas the remaining outer core is utilized as a dedicated channel to transmit upstream (US) signals. Optical carriers for US are delivered from the optical line terminal (OLT) to the optical network unit (ONU) via the inner core and then transmitted back to the OLT after amplification and modulation by the RSOA in the colorless ONU side. The mobile backhaul (MB) service is also supported by the inner core. Wavelengths used in US transmission should be different from that of the MB in order to avoid the Rayleigh backscattering effect in bidirectional transmission. With quadrature phase-shift keying-orthogonal frequency-division multiplexing (QPSK-OFDM) modulation format, the aggregation DS capacity reaches 250 Gb/s using five outer cores and ten wavelengths, and it can be further scaled to 1 Tb/s using 20 wavelengths modulated with 16 QAM-OFDM. For US transmission, 2.5 Gb/s QPSK-OFDM transmission can be achieved just using a low-bandwidth RSOA, and adaptive modulation is applied to the RSOA to further enhance the US data rate to 3.12 Gb/s. As an emulation of high-speed MB transmission, 48 Gb/s inphase and quadrature (IQ) modulated popularization division multiplexing (PDM)-QPSK signal is transmitted in the inner core of MCF and coherently detected in the OLT side. Both DS and US optical signals exhibit acceptable performance with sufficient power budget.
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| 5. |
- Feng, Zhenhua, et al.
(författare)
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Performance-Enhanced Direct Detection Optical OFDM Transmission With CAZAC Equalization
- 2015
-
Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 27:14, s. 1507-1510
-
Tidskriftsartikel (refereegranskat)abstract
- Direct detection optical orthogonal frequency division multiplexing (DDO-OFDM) transmission with constant amplitude zero autocorrelation (CAZAC) sequence equalization is proposed and experimentally demonstrated. Simulation results show that more than 2-dB peak-to-average power ratio (PAPR) reduction can be realized using CAZAC equalization, and 50-km standard single mode fiber (SSMF) transmission of 4.11-Gb/s QPSK-OFDM can be achieved with bit-error rate (BER) under forward error correction limit. Transmission performance of QPSK-based DDO-OFDM system is analyzed in both OB2B configuration and fiber link with and without CAZAC equalization. More than 2.5-dB optical receiver sensitivity improvements can be obtained thanks to the PAPR reduction enjoyed by CAZAC equalization. Signal-to-noise ratio for every subcarrier derived from error vector magnitude is estimated and its flatness is confirmed to be much improved with CAZAC equalization. The performance improvements brought by CAZAC equalization can be extended to other modulation formats, and 8.22-Gb/s 16-quadratic-amplitude modulation-OFDM signals transmission using CAZAC equalization is demonstrated with over 1.5 dB enhancement in receiver sensitivity.
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| 6. |
- Feng, Zhenhua, et al.
(författare)
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SNR equalized optical direct-detected OFDM transmission with CAZAC equalization
- 2015
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Ingår i: CLEO. - : Optica Publishing Group.
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Konferensbidrag (refereegranskat)abstract
- 50Km SSMF optical direct-detected OFDM transmission with Constant Amplitude Zero Auto Correlation Sequence (CAZAC) equalization is experimentally demonstrated with over 15dB power budget. 2.5dB enhancement in sensitivity has been achieved simultaneously with 3dB PAPR suppression.
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| 7. |
- Fornell, Anna, et al.
(författare)
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Fabrication of Silicon Microfluidic Chips for Acoustic Particle Focusing Using Direct Laser Writing
- 2020
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Ingår i: Micromachines. - : MDPI AG. - 2072-666X. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a fast and simple method for fabricating microfluidic channels in silicon using direct laser writing. The laser microfabrication process was optimised to generate microfluidic channels with vertical walls suitable for acoustic particle focusing by bulk acoustic waves. The width of the acoustic resonance channel was designed to be 380 µm, branching into a trifurcation with 127 µm wide side outlet channels. The optimised settings used to make the microfluidic channels were 50% laser radiation power, 10 kHz pulse frequency and 35 passes. With these settings, six chips could be ablated in 5 h. The microfluidic channels were sealed with a glass wafer using adhesive bonding, diced into individual chips, and a piezoelectric transducer was glued to each chip. With acoustic actuation at 2.03 MHz a half wavelength resonance mode was generated in the microfluidic channel, and polystyrene microparticles (10 µm diameter) were focused along the centre-line of the channel. The presented fabrication process is especially interesting for research purposes as it opens up for rapid prototyping of silicon-glass microfluidic chips for acoustofluidic applications.
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| 8. |
- Fornell, Anna, et al.
(författare)
-
Improved acoustic particle enrichment in droplets by optimising the droplet split design
- 2019
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Droplet microfluidics has emerged as a valuable platform for miniaturisation of biological experiments on-chip. In droplet microfluidic chips monodisperse droplets containing cells or other bioparticles can be generated at high throughput, and each droplet can be used as an isolated reaction chamber for individual measurements. A general trend in droplet microfluidics is reducing the size of the droplets, but the challenge is maintaining the particles in the droplets after splitting. We have previously reported on an acoustofluidic chip where bulk acoustic waves were used to control particle positioning in a trident-shaped droplet split. However, the reported particle enrichment was modest (3-fold), and the aim of this study is to increase the particle enrichment by optimising the droplet split design. With our new optimised droplet split we show up to 16.7-fold particle enrichment with high particle recovery.
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| 9. |
- Fornell, Anna, et al.
(författare)
-
Optimisation of the droplet split design for high acoustic particle enrichment in droplet microfluidics
- 2020
-
Ingår i: Microelectronic Engineering. - : Elsevier BV. - 0167-9317 .- 1873-5568. ; 226
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Tidskriftsartikel (refereegranskat)abstract
- We have characterised three droplet split designs for acoustic particle enrichment in water-in-oil droplets. The microfluidic channel design included a droplet generation junction, acoustic focusing channel and a trident-shaped droplet split. The microfluidic channels were dry-etched in silicon and sealed with glass lids by anodic bonding. To each microfluidic chip a piezoelectric transducer was glued, and at actuation of the transducer at the fundamental resonance frequency of the acoustic focusing channel (1.91–1.93 MHz), a half wavelength standing wave field was created between the channel walls. The acoustic force focused the encapsulated particles (3.2 μm, 4.8 μm and 9.9 μm diameter polystyrene microbeads) to the centre-line of the droplets, and when the droplets reached the droplet split the particles were directed into the centre daughter droplets. The results show that the design of the droplet split and the flow ratio between the centre and side outlet channels are the main factors that affect the particle enrichment and particle recovery in the centre daughter droplets. The highest particle enrichment was achieved in the droplet split design having the smallest centre channel (38 μm wide). Using this microfluidic chip design, we demonstrate up to 16.7-fold enrichment of 9.9 μm diameter polystyrene microbeads in the centre daughter droplets. This is almost three times higher particle enrichment than what has previously been presented using other intra-droplet particle enrichment techniques. Moreover, the acoustic technique is label-free and biocompatible.
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| 10. |
- Gu, Peng, et al.
(författare)
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A metabolite from commensal Candida albicans enhances the bactericidal activity of macrophages and protects against sepsis
- 2023
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Ingår i: Cellular & Molecular Immunology. - London : Nature Publishing Group. - 1672-7681 .- 2042-0226. ; 20:10, s. 1156-1170
-
Tidskriftsartikel (refereegranskat)abstract
- The gut microbiome is recognized as a key modulator of sepsis development. However, the contribution of the gut mycobiome to sepsis development is still not fully understood. Here, we demonstrated that the level of Candida albicans was markedly decreased in patients with bacterial sepsis, and the supernatant of Candida albicans culture significantly decreased the bacterial load and improved sepsis symptoms in both cecum ligation and puncture (CLP)-challenged mice and Escherichia coli-challenged pigs. Integrative metabolomics and the genetic engineering of fungi revealed that Candida albicans-derived phenylpyruvate (PPA) enhanced the bactericidal activity of macrophages and reduced organ damage during sepsis. Mechanistically, PPA directly binds to sirtuin 2 (SIRT2) and increases reactive oxygen species (ROS) production for eventual bacterial clearance. Importantly, PPA enhanced the bacterial clearance capacity of macrophages in sepsis patients and was inversely correlated with the severity of sepsis in patients. Our findings highlight the crucial contribution of commensal fungi to bacterial disease modulation and expand our understanding of the host-mycobiome interaction during sepsis development. © 2023, The Author(s), under exclusive licence to CSI and USTC.
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| 11. |
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| 12. |
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| 13. |
- Liu, Zhenhua, 1992-, et al.
(författare)
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A continuous on-chip droplet washing platform with high bead recovery by acoustofluidics
- 2019
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Acoustofluidics is a promising technology for manipulation of fluids and particles in microchannels, and the technology has the ability to sort beads and cells in continuous flow with very high efficiency. Recently acoustofluidics has also been applied in segmental flow for positioning beads inside droplets. Compared with single-phase systems, droplet microfluidics has the advantages of faster reactions, lower cross-contamination and higher throughput. Moreover, the small size of the droplets makes them ideal as cultivation and reaction vials for single cell analysis. However, as the droplets are so small one challenge is to wash the droplets before image analysis. P. Mary et al. developed a microfluidic platform for droplet wash, whichis based on electrocoalescence and droplet break-ups with equal volume. The background noise was decreased significantly, however the recovery of the encapsulated cells was low. Alternative solutions have been presented by H. Lee et al. and S.R. Doonan et al. but as the bead recovery is controlled via magnetophoresis, the technology is only applicable to magnetic samples. Here we present a droplet microfluidic platform that enables background dilution with high bead recovery in a label-free manner using acoustophoresis.
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| 14. |
- Liu, Zhenhua, 1992-, et al.
(författare)
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A droplet acoustofluidic platform for time-controlled microbead-based reactions
- 2021
-
Ingår i: Biomicrofluidics. - : American Institute of Physics (AIP). - 1932-1058. ; 15:3
-
Tidskriftsartikel (refereegranskat)abstract
- Droplet microfluidics is a powerful method used to characterize chemical reactions at high throughput. Often detection is performed via in-line optical readout, which puts high demands on the detection system or makes detection of low concentration substrates challenging. Here, we have developed a droplet acoustofluidic chip for time-controlled reactions that can be combined with off-line optical readout. The principle of the platform is demonstrated by the enzymatic conversion of fluorescein diphosphate to fluorescein by alkaline phosphatase. The novelty of this work is that the time of the enzymatic reaction is controlled by physically removing the enzymes from the droplets instead of using chemical inhibitors. This is advantageous as inhibitors could potentially interact with the readout. Droplets containing substrate were generated on the chip, and enzyme-coupled microbeads were added into the droplets via pico-injection. The reaction starts as soon as the enzyme/bead complexes are added, and the reaction is stopped when the microbeads are removed from the droplets at a channel bifurcation. The encapsulated microbeads were focused in the droplets by acoustophoresis during the split, leaving the product in the side daughter droplet to be collected for the analysis (without beads). The time of the reaction was controlled by using different outlets, positioned at different lengths from the pico-injector. The enzymatic conversion could be measured with fluorescence readout in a separate PDMS based assay chip. We show the ability to perform time-controlled enzymatic assays in droplet microfluidics coupled to an off-line optical readout, without the need of enzyme inhibitors.
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| 15. |
- Liu, Zhenhua, et al.
(författare)
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A Rapid Prototyping Technique for Microfluidics with High Robustness and Flexibility
- 2016
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Ingår i: Micromachines. - : MDPI AG. - 2072-666X. ; 7:11
-
Tidskriftsartikel (refereegranskat)abstract
- In microfluidic device prototyping, master fabrication by traditional photolithography is expensive and time-consuming, especially when the design requires being repeatedly modified to achieve a satisfactory performance. By introducing a high-performance/cost-ratio laser to the traditional soft lithography, this paper describes a flexible and rapid prototyping technique for microfluidics. An ultraviolet (UV) laser directly writes on the photoresist without a photomask, which is suitable for master fabrication. By eliminating the constraints of fixed patterns in the traditional photomask when the masters are made, this prototyping technique gives designers/researchers the convenience to revise or modify their designs iteratively. A device fabricated by this method is tested for particle separation and demonstrates good properties. This technique provides a flexible and rapid solution to fabricating microfluidic devices for non-professionals at relatively low cost.
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| 16. |
- Liu, Zhenhua, 1992-
(författare)
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Droplet Acoustofluidics for Biochemical Applications
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Droplet microfluidics is a promising platform for biochemical applications where compartmentalized droplets serve as individual vials. Droplets are formed by using two immiscible phases, the continuous phase and the dispersed phase, making up the droplets. Droplets are interesting because they can provide fast, parallel reactions with low reagent consumption. Microscale particles, such as cells, can be encapsulated in the droplets and chemical reagents can be added via a pico-injector. However, removal of droplet background signal is hard to achieved by conventional methods, especially if you do not want to risk losing the encapsulated cells. In this thesis, I present a droplet microfluidic system that can achieve this, via droplet-internal particle manipulation using acoustophoresis.This droplet microfluidic system contains pico-injection and droplet split with acoustophoresis. The pico-injection is used to add fresh solution into the droplets and the droplet split with acoustophoresis is used to remove the droplet supernatant. With the combination of the pico-injector and the droplet split, the background signal of the droplets can be reduced and the cell medium in the droplets can be exchanged. This droplet microfluidic system can also be used to control timing of enzyme reactions by initiating the reaction by adding enzyme-coupled beads via the pico-injector and taking a sample from the droplets at specific time points via side channels. In this work, I have also investigated how the design of the droplet split could be optimized to obtain high particle recovery and enrichment. Finally, acoustic properties of a selection of oils that can used as the continuous phase were mapped to optimize the droplet system for acoustophoresis.This thesis explores the biochemical applications performed by the droplet acoustofluidics, in-droplet time-controlled enzyme reaction and medium exchange for in-droplet cell culture. Furthermore, the droplet acoustofluidics has the potential to study the reaction kinetics by other enzymes and achieve long-term in-droplet cell culture.
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| 17. |
- Liu, Zhenhua, 1992-, et al.
(författare)
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Droplet Dilution Unit Operation Including Bead Washing Using Integrated Acoustophoresis
- 2019
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Ingår i: 2019 20TH INTERNATIONAL CONFERENCE ON SOLID-STATE SENSORS, ACTUATORS AND MICROSYSTEMS & EUROSENSORS XXXIII (TRANSDUCERS & EUROSENSORS XXXIII). - : IEEE. ; , s. 2333-2336
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Konferensbidrag (refereegranskat)abstract
- This paper presents a microfluidic platform on-chip droplet dilution where the bead recovery also can be controlled. The droplets containing 10 mu m polystyrene beads can be diluted with high bead recovery. This platform involves 5 steps for on-chip dilution of the droplets: droplet generation, bead focusing, droplet splitting, pica-injection and serpentine mixing. Background signal in the droplets is significantly reduced with maintained bead recovery by this on-chip dilution method. The technology is applicable to many types of samples and does not require any labelling of the bioparticles.
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| 18. |
- Liu, Zhenhua, 1992-, et al.
(författare)
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Enabling off-chip analysis for in-droplet enzyme reactions using acoustophoresis
- 2021
-
Konferensbidrag (refereegranskat)abstract
- Acoustophoresis is a commonly used technique to manipulate microbeads suspended in single-phase fluids [1]. Fornell et al. demonstrated that acoustophoresis can also be used to manipulate microbeads in droplets when the acoustic properties of the continuous phase match with the acoustic properties of the dispersed phase [2]. Water-in-oil droplets can be considered to be ideal vials for liquid mixing and reactions, as they allow for high throughput, low cross-contamination and low reagent consumption. Droplet microfluidics has previously been applied to study enzyme reactions [3,4]. However, these approaches are limited by on-chip detection and analysis since the enzyme is mixed with the product of the reaction inside the droplets. Here, we present an acoustofluidic chip where we can start the enzymatic reaction by injecting enzyme-coupled microbeads into the droplets containing the substrate by pico-injection and then stop the enzymatic reaction by removing the enzyme-coupled microbeads using acoustophoresis [5]. The analysis can then be performed off-chip, which allows for longer exposure times compared to performing the analysis in-line.
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| 19. |
- Liu, Zhenhua, 1992-, et al.
(författare)
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Long-term droplet cell culture enabled by droplet acoustofluidics
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Droplet microfluidics can be used to encapsulate cells for biochemical applications, such as single-cell analysis and drug screening. However, the concentration of nutrients and growth factors decreases over time, while the concentration of catabolic byproducts increases, that make droplet hard for long-term cell culture. Here, the cells encapsulated in droplets continued to divide in the first 8 hours and then stopped to grow. We developed a droplet acoustofluidic chip that can exchange cell medium in droplets by the combination of the pico-injection and the droplet split with acoustophoresis. After running droplets through this chip, cell medium in droplets got exchanged and the cells in droplets started to grow again. By this way, long-term droplet cell culture can be achieved.
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| 20. |
- Liu, Zhenhua, 1992-, et al.
(författare)
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On-chip background dilution in droplets with high particle recovery using acoustophoresis
- 2019
-
Ingår i: Biomicrofluidics. - : AIP Publishing. - 1932-1058. ; 13
-
Tidskriftsartikel (refereegranskat)abstract
- Droplet microfluidics has shown great potential for on-chip biological and chemical assays. However, fluid exchange in droplet microfluidics with high particle recovery is still a major bottleneck. Here, using acoustophoresis, we present for the first time a label-free method to achieve continuous background dilution in droplets containing cells with high sample recovery. The system comprises droplet generation, acoustic focusing, droplet splitting, picoinjection, and serpentine mixing on the same chip. The capacities of the picoinjection and the droplet split to dilute the background fluorescent signal in the droplets have been characterized. The sample recovery at different droplet split ratios has also been characterized. The results show a maximum of 4.3-fold background dilution with 87.7% particle recovery. We also demonstrated that the system can be used to dilute background fluorescent signal in droplets containing either polystyrene particles or endothelial cells.
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| 21. |
- Liu, Zhenhua, 1992-, et al.
(författare)
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Time-controlled Microbead-based Reactions in Droplets using Acoustophoresis
- 2021
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Ingår i: MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. - 9781733419031 ; , s. 893-894
-
Konferensbidrag (refereegranskat)abstract
- Droplet microfluidics is a powerful method to characterize chemical reactions at high throughput. Often detection is performed via in-line optical readout, which puts high demands on the detection system and makes detection of low concentration substrates challenging. Here, we have developed a droplet acoustofluidic chip for time-controlled microbead-based reactions that is combined with off-line optical readout.
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| 22. |
- Qin, Haihong, et al.
(författare)
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Evaluation and Suppression Method of Turn-off Current Spike for SiC/Si Hybrid Switch
- 2023
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Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 11, s. 26832-26842
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Tidskriftsartikel (refereegranskat)abstract
- SiC MOSFET/Si IGBT (SiC/Si) hybrid switch usually selects the gate control pattern that SiC MOSFET turns on earlier and turns off later than Si IGBT, with the aim of making the hybrid switch show excellent switching characteristics of SiC MOSFET and reduce switching loss. However, when SiC MOSFET turns off, the fast slew rate of drain source voltage causes the current spike in Si IGBT due to the effects of parasitic capacitance charging and carrier recombination, which will produce additional turn-off loss, thus affecting the overall efficiency and temperature rise of the converter. Based on the double pulse test circuit of SiC/Si hybrid switch, the mathematical model of the turn-off transient process is established. The effects of the remnant carrier recombination degree of Si IGBT, the turn-off speed of SiC MOSFET and the working conditions on the turn-off current spike of hybrid switch are evaluated. Although adjusting these parameters can reduce the turn-off current spike somewhat, additional losses will be introduced. Therefore, a new method to suppress the turn-off current spike is proposed to balance the power loss and current stress.
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| 23. |
- Radamson, Henry H., et al.
(författare)
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State of the Art and Future Perspectives in Advanced CMOS Technology
- 2020
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 10:8
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Forskningsöversikt (refereegranskat)abstract
- The international technology roadmap of semiconductors (ITRS) is approaching the historical end point and we observe that the semiconductor industry is driving complementary metal oxide semiconductor (CMOS) further towards unknown zones. Today's transistors with 3D structure and integrated advanced strain engineering differ radically from the original planar 2D ones due to the scaling down of the gate and source/drain regions according to Moore's law. This article presents a review of new architectures, simulation methods, and process technology for nano-scale transistors on the approach to the end of ITRS technology. The discussions cover innovative methods, challenges and difficulties in device processing, as well as new metrology techniques that may appear in the near future.
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| 24. |
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| 25. |
- Sabet, Julia A., 1986-, et al.
(författare)
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Paternal B Vitamin Intake Is a Determinant of Growth, Hepatic Lipid Metabolism and Intestinal Tumor Volume in Female Apc1638N Mouse Offspring
- 2016
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Ingår i: PLOS ONE. - an Francisco, CA, USA : Public Library of Science. - 1932-6203. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The importance of maternal nutrition to offspring health and risk of disease is well established. Emerging evidence suggests paternal diet may affect offspring health as well.OBJECTIVE: In the current study we sought to determine whether modulating pre-conception paternal B vitamin intake alters intestinal tumor formation in offspring. Additionally, we sought to identify potential mechanisms for the observed weight differential among offspring by profiling hepatic gene expression and lipid content.METHODS: Male Apc1638N mice (prone to intestinal tumor formation) were fed diets containing replete (control, CTRL), mildly deficient (DEF), or supplemental (SUPP) quantities of vitamins B2, B6, B12, and folate for 8 weeks before mating with control-fed wild type females. Wild type offspring were euthanized at weaning and hepatic gene expression profiled. Apc1638N offspring were fed a replete diet and euthanized at 28 weeks of age to assess tumor burden.RESULTS: No differences in intestinal tumor incidence or burden were found between male Apc1638N offspring of different paternal diet groups. Although in female Apc1638N offspring there were no differences in tumor incidence or multiplicity, a stepwise increase in tumor volume with increasing paternal B vitamin intake was observed. Interestingly, female offspring of SUPP and DEF fathers had a significantly lower body weight than those of CTRL fed fathers. Moreover, hepatic trigylcerides and cholesterol were elevated 3-fold in adult female offspring of SUPP fathers. Weanling offspring of the same fathers displayed altered expression of several key lipid-metabolism genes. Hundreds of differentially methylated regions were identified in the paternal sperm in response to DEF and SUPP diets. Aside from a few genes including Igf2, there was a striking lack of overlap between these genes differentially methylated in sperm and differentially expressed in offspring.CONCLUSIONS: In this animal model, modulation of paternal B vitamin intake prior to mating alters offspring weight gain, lipid metabolism and tumor growth in a sex-specific fashion. These results highlight the need to better define how paternal nutrition affects the health of offspring.
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| 26. |
- Shi, Qian, et al.
(författare)
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Mapping the acoustic properties of two-phase systems for use in droplet acoustofluidics
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The emergence of droplet microfluidics as a powerful tool for on-chip biological assays has prompted the development of a variety of intra-droplet particle manipulation techniques, such as droplet acoustofluidics. Previous study has shown that the acoustic properties between the continuous and dispersed phase must match for high-quality intra-droplet particle focusing. As a follow up, this study investigates the acoustic properties, i.e., speed of sound and density, of a selection of non-polar fluids that can be used as the continuous phase in droplet microfluidic systems. Our experimental results show that within our collection, linseed oil is the non-polar phase that most closely matches the acoustic properties of water and the fluorinated oil HFE-7500 is the one that least matches the acoustic properties compared to water. We believe this collection of data will serve the community by providing results that aid in the selection of continuous phase in future droplet acoustofluidic studies and data for performing acoustofluidic simulations.
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| 27. |
- Wang, Ruoxu, et al.
(författare)
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Demonstration of Programmable In-Band OSNR Monitoring Using LCFBG With Commercial Thermal Printer Head
- 2015
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Ingår i: IEEE PHOTONICS JOURNAL. - : Institute of Electrical and Electronics Engineers (IEEE). - 1943-0655. ; 7:4
-
Tidskriftsartikel (refereegranskat)abstract
- We proposed and experimentally demonstrated a programmable optical signal-to-noise ratio (OSNR) monitoring scheme by using linearly chirped fiber Bragg grating (LCFBG) and a commercial thermal printer head. For the coherent optical orthogonal frequency-division multiplexing (CO-OFDM) transmission system, the monitor's working wavelength can be flexibly software-controlled from 1530 to 1538 nm to support standard ITU-T grid or flex-grid operation. The linear OSNR monitoring range has been achieved from 9 to 26 dB for a 16-quadrature amplitude modulation (QAM) OFDM transmission system with negligible errors, respectively. Neither chromatic dispersion nor polarization mode dispersion affect the monitoring accuracy of our system.
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| 28. |
- Wang, Zhihang, 1989, et al.
(författare)
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Chip-scale solar thermal electrical power generation
- 2022
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Ingår i: Cell Reports Physical Science. - : Elsevier BV. - 2666-3864. ; 3:3
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Tidskriftsartikel (refereegranskat)abstract
- There is an urgent need for alternative compact technologies that can derive and store energy from the sun, especially the large amount of solar heat that is not effectively used for power generation. Here, we report a combination of solution- and neat-film-based molecular solar thermal (MOST) systems, where solar energy can be stored as chemical energy and released as heat, with microfabricated thermoelectric generators to produce electricity when solar radiation is not available. The photophysical properties of two MOST couples are characterized both in liquid with a catalytical cycling setup and in a phase-interconvertible neat film. Their suitable photophysical properties let us combine them individually with a microelectromechanical ultrathin thermoelectric chip to use the stored solar energy for electrical power generation. The generator can produce, as a proof of concept, a power output of up to 0.1 nW (power output per unit volume up to 1.3 W m−3). Our results demonstrate that such a molecular thermal power generation system has a high potential to store and transfer solar power into electricity and is thus potentially independent of geographical restrictions.
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| 29. |
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| 30. |
- Xu, Wenchao, et al.
(författare)
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Viscosity-difference-induced asymmetric selective focusing for large stroke particle separation
- 2016
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Ingår i: Microfluidics and Nanofluidics. - : Springer Science and Business Media LLC. - 1613-4982 .- 1613-4990. ; 20:9
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Tidskriftsartikel (refereegranskat)abstract
- We developed a new approach for particle separation by introducing viscosity difference of the sheath flows to form an asymmetric focusing of sample particle flow. This approach relies on the high-velocity gradient in the asymmetric focusing of the particle flow to generate a lift force, which plays a dominated role in the particle separation. The larger particles migrate away from the original streamline to the side of the higher relative velocity, while the smaller particles remain close to the streamline. Under high-viscosity (glycerol-water solution) and low-viscosity (PBS) sheath flows, a significant large stroke separation between the smaller (1.0 mu m) and larger (9.9 mu m) particles was achieved in a sample microfluidic device. We demonstrate that the flow rate and the viscosity difference of the sheath flows have an impact on the interval distance of the particle separation that affects the collected purity and on the focusing distribution of the smaller particles that affects the collected concentration. The interval distance of 293 mu m (relative to the channel width: 0.281) and the focusing distribution of 112 mu m (relative to the channel width: 0.107) were obtained in the 1042-mu m-width separation area of the device. This separation method proposed in our work can potentially be applied to biological and medical applications due to the wide interval distance and the narrow focusing distribution of the particle separation, by easy manufacturing in a simple device.
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| 31. |
- Yu, Xianxi, et al.
(författare)
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Memory Devices via Unipolar Resistive Switching in Symmetric Organic-Inorganic Perovskite Nanoscale Heterolayers
- 2020
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Ingår i: ACS Applied Nano Materials. - : AMER CHEMICAL SOC. - 2574-0970. ; 3:12, s. 11889-11896
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Tidskriftsartikel (refereegranskat)abstract
- Organic-inorganic hybrid perovskite thin films with nanostructured polycrystalline grains have shown great potential in various nanoscale optoelectrical applications. Among them, the field of electrical memory has fallen behind due to insufficient knowledge of the related resistive switching characters and mechanisms. In the present work, switching behaviors of perovskite memory devices are systematically analyzed by comparing them with organic memory devices. We found that decreasing the conductivity of a polycrystalline perovskite thin layer would lead to unipolar switching behaviors, which is supplementary to the present perovskite memory family where bipolar switching is commonly reported. Moreover, our proposed symmetrical device with a nanoscale heterolayer structure enables us not only to achieve highly reproducible unipolar switching devices but also to settle the argument whether microconducting channels exist within perovskite memory devices through characterizing the microscopic morphological homogeneity. Surprisingly, the scanning electron microscopy results show that partial 10 pm large perovskite grains would be decomposed into various 100 nm small grains under high external bias, indicating the presence of microconducting channels. Furthermore, energy-dispersive X-ray spectroscopy results together with photoluminescence results of the perovskite thin film before and after applying bias are nearly identical, demonstrating that microconducting channels are formed without any difference in compositions or optical properties. Our discoveries provide a practical strategy to achieve electrical storage via organic-inorganic hybrid perovskite thin-film devices.
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| 32. |
- Zhuang, Ting, et al.
(författare)
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SHARPIN stabilizes estrogen receptor a and promotes breast cancer cell proliferation
- 2017
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 8:44, s. 77137-77151
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Tidskriftsartikel (refereegranskat)abstract
- Estrogen receptor a is expressed in the majority of breast cancers and promotes estrogen-dependent cancer progression. In our study, we identified the novel E3 ubiquitin ligase SHARPIN function to facilitate ERα signaling. SHARPIN is highly expressed in human breast cancer and correlates with ERα protein level by immunohistochemistry. SHARPIN expression level correlates with poor prognosis in ERα positive breast cancer patients. SHARPIN depletion based RNA-sequence data shows that ERα signaling is a potential SHARPIN target. SHARPIN depletion significantly decreases ERα protein level, ERα target genes expression and estrogen response element activity in breast cancer cells, while SHARPIN overexpression could reverse these effects. SHARPIN depletion significantly decreases estrogen stimulated cell proliferation in breast cancer cells, which effect could be further rescued by ERα overexpression. Further mechanistic study reveals that SHARPIN mainly localizes in the cytosol and interacts with ERα both in the cytosol and the nuclear. SHARPIN regulates ERα signaling through protein stability, not through gene expression. SHARPIN stabilizes ERα protein via prohibiting ERα protein poly-ubiquitination. Further study shows that SHARPIN could facilitate the mono-ubiquitinaiton of ERα at K302/303 sites and facilitate ERE luciferase activity. Together, our findings propose a novel ERα modulation mechanism in supporting breast cancer cell growth, in which SHARPIN could be one suitable target for development of novel therapy for ERα positive breast cancer.
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