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Zeng Q, Tang Z, Ouyang D, Yu L, Wang J, Luo X, Dong W, Yan P, Wang J, Wang P, Lue Q, Guo C, Ruan S. Wavelength-tunable spatiotemporal mode-locking in a large-mode-area Er:ZBLAN fiber laser at 2.8 µm. Opt Lett 2024; 49:1117-1120. [PMID: 38426952 DOI: 10.1364/ol.515735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/21/2024] [Indexed: 03/02/2024]
Abstract
We report a tunable spatiotemporally mode-locked large-mode-area Er:ZBLAN fiber laser based on the nonlinear polarization rotation technique. A diffraction grating is introduced to select the operating wavelength. Under the spectral and spatial filtering effects provided by the grating and spatial coupling respectively, stable ps-level spatiotemporally mode-locked pulses around 2.8 µm with a repetition rate of 43.4 MHz are generated. Through a careful adjustment of the grating, a broad wavelength tuning range from 2747 to 2797 nm is realized. To the best of our knowledge, this is the first wavelength-tunable spatiotemporally mode-locked fiber laser in the mid-infrared region.
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Zhao J, Chen Y, Ouyang D, Liu M, Li C, Wu X, Xiong X, Mo L, Wang M, Liu X, Lv Q, Ruan S. Over 3.8 W, 3.4 µm picosecond mid-infrared parametric conversion based on a simplified one-to-many scheme. Opt Express 2024; 32:8364-8378. [PMID: 38439493 DOI: 10.1364/oe.516265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/10/2024] [Indexed: 03/06/2024]
Abstract
In this paper, we demonstrate a simplified one-to-many scheme for efficient mid-infrared (MIR) parametric conversion. Such a scheme is based on a continuous wave (CW) single longitudinal mode master oscillator power-amplifier (MOPA) fiber system as the signal source and a picosecond pulsed MOPA fiber system, exhibiting multiple longitudinal modes, as the pump source. The signal and pump beams are combined and co-coupled into a piece of 50-mm long 5% MgO-doped PPLN crystal for the parametric conversion. As high as ∼3.82 W average power at a central idler wavelength of ∼3.4 µm is achieved when the launched pump and signal powers are ∼41.73 and ∼11.45 W, respectively. Above some threshold value, the delivered idler power shows a roll-over effect against the signal power and saturation-like effect against the pump power. Consequently, the highest conversion efficiency is observed at such a threshold pump power. To the best of our knowledge, our result represents the highest average power produced from any single-pass parametric conversion source with >3 µm idler wavelength feeding with a CW signal. Moreover, our proposed scheme can simplify the design of parametric conversion system significantly and meanwhile make the system more robust in applications. This is attributed to two main aspects. Firstly, the scheme's one-to-many feature can reduce wavelength sensitivity remarkably in the realization of quasi-phase-matching. Secondly, for moderate power requirement it does not always require a high peak power synchronized pulsed signal source; a CW one can be an alternative, thereby making the system free from complex time synchronization and the related time jitter.
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Gasho JO, Silos K, Guthier CV, Zhang SC, Burnison M, Mirhadi AJ, Jang JK, Shiao SL, Kamrava M, Steers J, McKenzie E, Tamarappoo B, Ouyang D, Kwan AC, Nikolova A, Mak RH, Atkins KM. Association of Left Anterior Descending Coronary Artery Calcium Progression and Radiation Dose with Major Adverse Cardiac Events in Breast Cancer. Int J Radiat Oncol Biol Phys 2023; 117:e175. [PMID: 37784789 DOI: 10.1016/j.ijrobp.2023.06.1020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Coronary artery calcium (CAC) is associated with increased risk of major adverse cardiac events (MACE). Accelerated CAC progression has been observed in patients with breast cancer after radiotherapy (RT) and there is a relationship between left anterior descending (LAD) coronary artery RT dose and the risk of coronary events. However, there is lack of consensus on LAD dose constraints for breast RT and limited data on the extent and impact of CAC progression. Our objective was to evaluate the association of LAD dose exposure and CAC progression with the risk of MACE in patients with breast cancer following RT. MATERIALS/METHODS Retrospective analysis of 181 patients with breast cancer treated with RT between 2008 and 2019. CAC was manually measured on RT planning and follow-up CTs (with at least one-year interval) using the Agatston method. Coronary arteries were segmented using a deep learning-based automated algorithm and dosimetric parameters collected. MACE cumulative incidence was estimated, and Fine and Gray regressions performed, accounting for non-cardiac death as a competing risk. RESULTS The median follow-up following RT was 70 months (interquartile range [IQR], 53-86). The median age was 63 years (IQR, 53-72), 43% had hypertension, 40% hyperlipidemia, 8% coronary heart disease (CHD). Most had pathologic stage I-II disease (76%). RT was targeted to breast/chest wall only in 60% and included regional nodes in 40% (internal mammary chain in 4%). The most common dose/fractionation was 48-50.4 Gy/25-28 fractions (67%) and 42.6-42.7 Gy/16 fractions (30%). At the time of RT, 68 (38%) had at least moderate CAC burden (CAC >100; statin-therapy indicated), but only 29 (43%) were on statin therapy. At a median interval of 44 months (IQR, 26-63), 55% (n = 84) had CAC progression, with a median increase of 52%/year (IQR, 18-193). The median time to MACE was 68 months (IQR, 53-85), with a 5-year cumulative incidence of 7.3% (15 MACE overall). Accounting for age and CHD, there was an increased risk of MACE with LAD CAC progression (subdistribution hazard ratio [SHR] 1.02/10 CAC points; 95% confidence interval [CI] 1.01 = 1.03; p = .007) and the volume of LAD receiving 15 Gy (LAD V15 Gy; SHR 1.03/%; 95% CI, 1.01-1.06; p = .004). There was no association between mean heart dose, chemotherapy, or Her2 therapy exposure and MACE (p>.05). CONCLUSION LAD CAC progression and LAD V15 Gy dose exposure were associated with an increased risk of MACE following RT. Accelerated CAC progression was commonly observed, however most patients were under-optimized for cardiovascular (CV) risk, with less than half of statin-eligible patients with at least moderate CAC burden on statin therapy. Together, these data support more aggressive cardiac risk mitigation approaches, including guidelines-based CV risk factor modification and optimized sparing of LAD radiation dose.
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Affiliation(s)
- J O Gasho
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - K Silos
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - C V Guthier
- Department of Radiation Oncology, Brigham and Women's Hospital/Dana-Farber Cancer Institute, Boston, MA
| | - S C Zhang
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - M Burnison
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - A J Mirhadi
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - J K Jang
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - S L Shiao
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - M Kamrava
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - J Steers
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - E McKenzie
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - B Tamarappoo
- Department of Cardiology, Indiana University, Indianapolis, IN
| | - D Ouyang
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - A C Kwan
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - A Nikolova
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - R H Mak
- Department of Radiation Oncology, Brigham and Women's Hospital/Dana-Farber Cancer Institute, Boston, MA
| | - K M Atkins
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
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Pang J, Yu J, Yang H, Ruan S, Ouyang D, Yang C, Deng L. Non-uniform droplet deposition on femtosecond laser patterned superhydrophobic/superhydrophilic SERS substrates for high-sensitive detection. Opt Express 2023; 31:19886-19896. [PMID: 37381394 DOI: 10.1364/oe.491434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/18/2023] [Indexed: 06/30/2023]
Abstract
Surface-enhanced Raman scattering (SERS) sensors combined with superhydrophobic/superhydrophilic (SH/SHL) surfaces have shown the ability to detect ultra-low concentrations. In this study, femtosecond laser fabricated hybrid SH/SHL surfaces with designed patterns are successfully applied to improve the SERS performances. The shape of SHL patterns can be regulated to determine the droplet evaporation process and deposition characteristics. The experimental results show that the uneven droplet evaporation along the edges of non-circular SHL patterns facilitates the enrichment of analyte molecules, thereby enhancing the SERS performance. The highly identifiable corners of SHL patterns are beneficial for capturing the enrichment area during Raman tests. The optimized 3-pointed star SH/SHL SERS substrate shows a detection limit concentration as low as 10-15 M by using only 5 µL R6G solutions, corresponding to an enhancement factor of 9.73 × 1011. Meanwhile, a relative standard deviation of 8.20% can be achieved at a concentration of 10-7 M. The research results suggest that the SH/SHL surfaces with designed patterns could be a practical approach in ultratrace molecular detections.
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Liu J, Ma H, Meng L, Yang H, Yang C, Ruan S, Ouyang D, Mei S, Deng L, Chen J, Cao Y. Laser Powder Bed Fusion of 316L Stainless Steel: Effect of Laser Polishing on the Surface Morphology and Corrosion Behavior. Micromachines (Basel) 2023; 14:850. [PMID: 37421082 DOI: 10.3390/mi14040850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 03/30/2023] [Accepted: 04/12/2023] [Indexed: 07/09/2023]
Abstract
Recently, laser polishing, as an effective post-treatment technology for metal parts fabricated by laser powder bed fusion (LPBF), has received much attention. In this paper, LPBF-ed 316L stainless steel samples were polished by three different types of lasers. The effect of laser pulse width on surface morphology and corrosion resistance was investigated. The experimental results show that, compared to the nanosecond (NS) and femtosecond (FS) lasers, the surface material's sufficient remelting realized by the continuous wave (CW) laser results in a significant improvement in roughness. The surface hardness is increased and the corrosion resistance is the best. The microcracks on the NS laser-polished surface lead to a decrease in the microhardness and corrosion resistance. The FS laser does not significantly improve surface roughness. The ultrafast laser-induced micro-nanostructures increase the contact area of the electrochemical reaction, resulting in a decrease in corrosion resistance.
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Affiliation(s)
- Jun Liu
- Zhejiang Provincial Key Laboratory of Laser Processing Robotics, College of Mechanical & Electrical Engineering, Wenzhou University, Wenzhou 325035, China
| | - Haojun Ma
- Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, China
| | - Lingjian Meng
- Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, China
| | - Huan Yang
- Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, China
| | - Can Yang
- Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, China
| | - Shuangchen Ruan
- Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, China
| | - Deqin Ouyang
- Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, China
| | - Shuwen Mei
- Nantong Jinyuan Intelligent Technology Co., Nantong 226007, China
| | - Leimin Deng
- Wuhan National Research Center for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jie Chen
- Wenzhou University Rui'an Graduate College, Wenzhou University, Ruian 325207, China
| | - Yu Cao
- Zhejiang Provincial Key Laboratory of Laser Processing Robotics, College of Mechanical & Electrical Engineering, Wenzhou University, Wenzhou 325035, China
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Wang M, Zhao J, Chen Y, Liu M, Ouyang D, Pei J, Ruan S. 10 µJ noise-like pulse generated from all fiberized Tm-doped fiber oscillator and amplifier. Opt Express 2021; 29:10172-10180. [PMID: 33820150 DOI: 10.1364/oe.421867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
Herein, we presented a high energy noise-like (NL) pulse Tm-doped fiber laser (TDFL) system. Relying on the nonlinear amplifying loop mirror (NALM), stable noise-like pulses with coherence spike width of ∼317 fs and envelope width of ∼4.2 ns were obtained from an all polarization-maintaining fiberized oscillator at central wavelength of ∼1946.4 nm with 3 dB bandwidth of ∼24.9 nm. After the amplification in an all-fiberized TDF amplifier system, the maximum average output power of ∼32.8 W and pulse energy of ∼10.1 µJ were obtained, which represents the highest pulse energy of NL pulse at ∼2 µm, to the best of our knowledge. We believe that the high energy NL pulse source has the potential application in mid-infrared supercontinuum generation.
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Shen R, Fang H, Zhao J, Ouyang D, Wang M, Wu X, Ruan S. Over 10 W linearly polarized supercontinuum directly produced in an erbium-doped fiber MOPA seeded with stretched soliton. Appl Opt 2021; 60:257-263. [PMID: 33448947 DOI: 10.1364/ao.411860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/04/2020] [Indexed: 06/12/2023]
Abstract
We experimentally achieve over 10 W linearly polarized supercontinuum (SC) generation in a polarization-maintaining (PM) erbium-doped fiber (EDF) master oscillator power-amplifier (MOPA). The house-built PM seeding EDF laser can deliver ∼209fs soliton around ∼1563.7nm, which is then stretched to >15ps using a long piece of normal-dispersion fiber. The wideband spectrum of the ultrashort seeding soliton facilitates the further spectral broadening with nonlinear effects. The soliton stretching decelerates the peak power increase, thus facilitating higher amplified average power. After several stages of pre-amplification, the stretched soliton is fed into the main amplifier constructed with PM large mode area fibers. The output average power is finally amplified to ∼11.51W. The corresponding spectrum spans from ∼1450 to ∼2200nm, indicating that SC is formed due to the induced strong nonlinear effects. The polarization extinction ratio at the output reaches over 18 dB. The PM characteristic potentially enhances the system's resistance to environmental disturbances and eliminates instabilities relating to polarization-mode coupling. Our result represents, so far, the highest SC power directly produced in an EDF MOPA, to the best of our knowledge, especially in a linearly polarized manner. This also suggests a scheme for powerful SC generation that employs direct laser diode pumping and duration-managed pulse seeding.
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He D, Nie C, Zheng L, An A, Li H, Ouyang D. GITR agonist sensitizes MC38/OVA tumor to CTLA4 treatment by attenuating Tregs in GITR HuGEMM. Eur J Cancer 2020. [DOI: 10.1016/s0959-8049(20)31103-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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9
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Bourre L, Xu X, Shang L, Wang L, Li C, Liu Y, Han P, Sun Z, Qu Y, Zhang L, Chen B, Ouyang D, Huang Y, Li H. 42P The establishment of a large tumor organoid biobank using a well characterized/annotated patient-derived xenograft (PDX) library to enable drug discovery and translational research. Ann Oncol 2020. [DOI: 10.1016/j.annonc.2020.01.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Zheng Z, Wang J, Yin J, Ouyang D, Ren X, Yan P, Wang J, Pei J, Lue Q, Ruan S. High-power mode-locked thulium-doped fiber laser with tungsten ditelluride as saturable absorber. Appl Opt 2020; 59:196-200. [PMID: 32225288 DOI: 10.1364/ao.59.000196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
A passively mode-locked thulium-doped fiber laser using a tungsten ditelluride saturable absorber (${{\rm WTe}_2}\mbox{-}{\rm SA}$WTe2-SA) is demonstrated. High-power mode-locked pulses with an average output power of 108.1 mW were achieved by incorporating the ${{\rm WTe}_2}\mbox{-}{\rm SA}$WTe2-SA into a thulium-doped fiber oscillator. To the best of our knowledge, this is the highest average power obtained from a ${{\rm WTe}_2}\mbox{-}{\rm SA}$WTe2-SA-based fiber laser. We further amplified the output power to 5.60 W with an all-fiber thulium-doped double-cladding fiber amplifier. Our result indicates that ${{\rm WTe}_2}\mbox{-}{\rm SA}$WTe2-SA could be an excellent candidate for a high-power fiber laser system.
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Zheng Z, Ren X, Zhu K, Ouyang D, Wang J, Guo C, Du G, Pei J, Lue Q, Ruan S. Fundamental and harmonic mode-locked h-shaped pulse generation using a figure-of-9 thulium-doped fiber laser. Opt Express 2019; 27:37172-37179. [PMID: 31878502 DOI: 10.1364/oe.27.037172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 12/02/2019] [Indexed: 06/10/2023]
Abstract
Herein, we present a fundamental and harmonic mode-locked figure-of-9 thulium-doped fiber laser using a nonlinear amplifying loop mirror. The generated fundamental mode-locked h-shaped pulse is centered at 1889 nm with an average output power reaching 282 mW and a pulse energy up to 1.23 µJ, which is the highest power and pulse energy of an h-shaped pulse. In the harmonic mode-locked regime, up to the 8th harmonic h-shaped pulse is obtained. The detailed characteristics of the h-shaped pulse are discussed. The proposed study shows that the figure-of-9 fiber laser can generate h-shaped pulses and also allows the generation of nanosecond pulses with a µJ-level pulse energy.
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Ouyang D, Gulati G, Ha R, Banerjee D. Incidence and Outcomes of Acute Circulatory Support Prior to Heart Transplantation. J Heart Lung Transplant 2017. [DOI: 10.1016/j.healun.2017.01.361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Wang Z, Ouyang D, An A, Cai B, Chen G, Liu J, Dong X, Li H. Mouse tumor HuGEMM-h/mCTLA-4 models for assessing human anti-CTLA-4 therapeutics. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)32921-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Wang J, Liang X, Hu G, Zheng Z, Lin S, Ouyang D, Wu X, Yan P, Ruan S, Sun Z, Hasan T. 152 fs nanotube-mode-locked thulium-doped all-fiber laser. Sci Rep 2016; 6:28885. [PMID: 27374764 PMCID: PMC4931500 DOI: 10.1038/srep28885] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 06/10/2016] [Indexed: 11/13/2022] Open
Abstract
Ultrafast fiber lasers with broad bandwidth and short pulse duration have a variety of applications, such as ultrafast time-resolved spectroscopy and supercontinuum generation. We report a simple and compact all-fiber thulium-doped femtosecond laser mode-locked by carbon nanotubes. The oscillator operates in slightly normal cavity dispersion at 0.055 ps2, and delivers 152 fs pulses with 52.8 nm bandwidth and 0.19 nJ pulse energy. This is the shortest pulse duration and the widest spectral width demonstrated from Tm-doped all-fiber lasers based on 1 or 2 dimensional nanomaterials, underscoring their growing potential as versatile saturable absorber materials.
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Affiliation(s)
- Jinzhang Wang
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xiaoyan Liang
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Guohua Hu
- Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, United Kingdom
| | - Zhijian Zheng
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Shenghua Lin
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Deqin Ouyang
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xu Wu
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Peiguang Yan
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Shuangchen Ruan
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Zhipei Sun
- Department of Micro- and Nanosciences, Aalto University, Aalto, FI-00076, Finland
| | - Tawfique Hasan
- Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, United Kingdom
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Zhao J, Ouyang D, Zheng Z, Liu M, Ren X, Li C, Ruan S, Xie W. 100 W dissipative soliton resonances from a thulium-doped double-clad all-fiber-format MOPA system. Opt Express 2016; 24:12072-12081. [PMID: 27410128 DOI: 10.1364/oe.24.012072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this paper, we first achieve nanosecond-scale dissipative soliton resonance (DSR) generation in a thulium-doped double-clad fiber (TDF) laser with all-anomalous-dispersion regime, and also first scale the average power up to 100.4 W by employing only two stage TDF amplifiers, corresponding to gains of 19.3 and 14.4 dB, respectively. It is noted that both the fiber laser oscillator and the amplification system employ double-clad fiber as the gain medium for utilizing the advantages in high-gain-availability, high-power-handling and good-mode-quality-maintaining. DSR mode-locking of the TDF oscillator is realized by using a nonlinear optical loop mirror (NOLM), which exhibits all-fiber-format, high nonlinear and passive saturable absorption properties. The TDF oscillator can deliver rectangular-shape pulses with duration ranging from ~3.74 to ~72.19 ns while maintaining a nearly equal output peak power level of ~0.56 W, namely peak power clamping (PPC) effect. Comparatively, the two stage amplifiers can scale the seeding pulses to similar average power levels, but to dramatically different peak powers ranging from ~0.94 to ~18.1 kW depending on the durations. Our TDF master-oscillator-power-amplifier (MOPA) system can provide a high power 2-μm band all-fiber-format laser source both tunable in pulse duration and peak power.
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Ouyang D, El-Sayed I, Yom S. National Trends in Surgery for Sinonasal Malignancy and the Effect of Hospital Volume on Short-Term Outcomes. Int J Radiat Oncol Biol Phys 2014. [DOI: 10.1016/j.ijrobp.2013.11.110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Shurter A, Genter P, Ouyang D, Ipp E. Euglycemic progression: worsening of diabetic retinopathy in poorly controlled type 2 diabetes in minorities. Diabetes Res Clin Pract 2013; 100:362-7. [PMID: 23566652 PMCID: PMC3713071 DOI: 10.1016/j.diabres.2013.03.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Revised: 02/13/2013] [Accepted: 03/06/2013] [Indexed: 12/24/2022]
Abstract
AIMS In type 2 diabetes, early effects of strict near-normalization of glucose control on macrovascular and microvascular disease are still uncertain. We evaluated the effects of early dramatic improvement in glycemia on retinal disease in poorly controlled diabetes. METHODS A retrospective, case-control study in public hospital patients with type 2 diabetes, who had annual retinal imaging as part of a case management program or standard diabetes care. Patients included had ≥2 two retinal images ≥1 one year apart, and at least 3 HbA1C measurements. Retinal images were graded using a modified Scottish Diabetic Retinopathy grading scheme. An 'intensive' group (n=34) with HbA1C decrease >1.5% was compared with randomly chosen patients (n=34) with minimal HbA1C changes. RESULTS Mean HbA1C (±SEM) over two years was similar in intensive (8.5 ± 0.21%) and control groups (8.1 ± 0.28%, p=NS). However, the intensive group had higher baseline HbA1C and a mean maximal decrease of 4.0 ± 0.41% in contrast to the control group (0.2 ± 0.11%). Retinopathy grade progressed +0.7 ± 0.25 units from baseline in the intensive group (p=0.015), a 22.6% worsening. The control group changed minimally from baseline (0.03 ± 0.14 units, p=NS). Change in retinopathy grade was significantly different between groups (p=0.02). More eyes worsened by ≥ 1 retinal grade (p=0.0025) and developed sight-threatening retinopathy (p=0.003) in the intensive group. Visual acuity was unchanged. CONCLUSIONS Diabetic retinopathy significantly worsened in poorly controlled type 2 diabetes after early intensification of glycemic control and dramatic HbA1C change. Retinal status should be part of risk-factor evaluation in patients likely to experience marked reductions in HbA1C in poorly controlled diabetes.
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Affiliation(s)
- A Shurter
- Department of Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, United States
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Abstract
OBJECTIVE To examine national time trends of resective surgery for the treatment of medically refractory epilepsy before and after Class I evidence demonstrating its efficacy and subsequent practice guidelines recommending early surgical evaluation. METHODS We performed a population-based cohort study with time trends of patients admitted to US hospitals for medically refractory focal epilepsy between 1990 and 2008 who did or did not undergo lobectomy, as reported in the Nationwide Inpatient Sample. RESULTS Weighted data revealed 112,026 hospitalizations for medically refractory focal epilepsy and 6,653 resective surgeries (lobectomies and partial lobectomies) from 1990 to 2008. A trend of increasing hospitalizations over time was not accompanied by an increase in surgeries, producing an overall trend of decreasing surgery rates (F = 13.6, p < 0.01). Factors associated with this trend included a decrease in epilepsy hospitalizations at the highest-volume epilepsy centers, and increased hospitalizations to lower-volume hospitals that were found to be less likely to perform surgery. White patients were more likely to have surgery than racial minorities (relative risk [RR], 1.13; 95% confidence interval [CI], 1.10-1.17), and privately insured individuals were more likely to receive lobectomy than those with Medicaid or Medicare (RR, 1.28; 95% CI, 1.25-1.30). CONCLUSION Despite Class I evidence and subsequent practice guidelines, the utilization of lobectomy has not increased from 1990 to 2008. Surgery continues to be heavily underutilized as a treatment for epilepsy, with significant disparities by race and insurance coverage. Patients who are medically refractory after failing 2 antiepileptic medications should be referred to a comprehensive epilepsy center for surgical evaluation.
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Affiliation(s)
- D J Englot
- UCSF Epilepsy Center, University of California, San Francisco, CA, USA
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Borri P, Langbein W, Schneider S, Woggon U, Sellin RL, Ouyang D, Bimberg D. Relaxation and dephasing of multiexcitons in semiconductor quantum dots. Phys Rev Lett 2002; 89:187401. [PMID: 12398633 DOI: 10.1103/physrevlett.89.187401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2002] [Indexed: 05/24/2023]
Abstract
We measure the dephasing time of ground-state excitonic transitions in InGaAs quantum dots under electrical injection in the temperature range from 10 to 70 K. Electrical injection into the barrier region results in a pure dephasing of the excitonic transitions. Once the injected carriers fill the electronic ground state, the biexciton to exciton transition is probed and a correlation of the exciton and biexciton phonon scattering mechanisms is found. Additional filling of the excited states creates multiexcitons that show a fast dephasing due to population relaxation.
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Affiliation(s)
- P Borri
- Experimentelle Physik IIb, Universität Dortmund, Otto-Hahn Strasse 4, D-44221 Dortmund, Germany
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Ouyang D, Qiu H, Lu X, Long M. [Analysis of complications and deaths in aged patients with obstructive jaundice]. Hunan Yi Ke Da Xue Xue Bao 2002; 24:181-2, 210. [PMID: 11938786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The reasons of complications and deaths in 98 aged patients with obstructive jaundice were analysed in the paper. Among them, 52 cases were diagnosed as benign obstruction, 46 cases as malignant obstruction; 92 patients were treated by surgical management(15 died), 6 patients were treated without operation(4 died). The results showed that effective management on time and intensive perioperative care are important to minimize the mortality rate. Malignant obstructive jaundice was more harmful to the patients' renal function no the mortality rate would be increased. The operations, internal drainage and pressure reduction of biliary duct, were performed on time, thus the survival rate was improve.
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Affiliation(s)
- D Ouyang
- Department of Surgery, Xiangya Hospital, Hunan Medical University, Changsha 410008
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21
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Borri P, Langbein W, Schneider S, Woggon U, Sellin RL, Ouyang D, Bimberg D. Ultralong dephasing time in InGaAs quantum dots. Phys Rev Lett 2001; 87:157401. [PMID: 11580725 DOI: 10.1103/physrevlett.87.157401] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2001] [Indexed: 05/23/2023]
Abstract
We measure a dephasing time of several hundred picoseconds at low temperature in the ground-state transition of strongly confined InGaAs quantum dots, using a highly sensitive four-wave mixing technique. Between 7 and 100 K the polarization decay has two distinct components resulting in a non-Lorentzian line shape with a lifetime-limited zero-phonon line and a broadband from elastic exciton-acoustic phonon interactions.
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Affiliation(s)
- P Borri
- Experimentelle Physik IIb, Universität Dortmund, Otto-Hahn Strasse 4, D-44221 Dortmund, Germany
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Wei Y, Ouyang D, Liu Y, Chang Z, Tang J, Ding J. Peripheral tissue distribution of orphanin FQ precusor mRNA in stroke-prone spontaneously hypertensive rats. Chin Med Sci J 1999; 14:67-70. [PMID: 12901610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The heptadecapeptide orphanin FQ (OFQ) is a recently discovered neuropeptide that exhibits structural features reminiscent of the opioid peptides and that is an endogenous ligant to a G protein-coupled receptor sequentially related to the opioid receptors. OFQ was originally isolated from brain, but the presence of OFQ in peripheral tissues, especially in cardiovascular system, has not been clarified. The present study was designed to investigate the peripheral tissue distribution of OFQ precusor mRNA in stroke-prone spontaneously hypertensive rats (SHRSP) and compare the difference of OFQ precusor mRNA expression in aorta or cultured vascular smooth muscle cells (VSMCs) between SHRSP and wistar-Kyoto normotensive (WKY) rats. By using quantitative reverse transcription-polymerase chain reaction (RT-PCR), OFQ precusor mRNA was detected in aorta and ovary at high levels comparable with the amounts found in brain. Moderate expression was found in testis, while a little OFQ precusor mRNA could be detected in atrium. All other peripheral tissues examined from SHRSP, including ventricle, liver, lung and kidney, showed no expression of OFQ precusor mRNA. In the vascular system, OFQ precusor mRNA was expressed in aorta, pulmonary artery, renal artery and vein at high levels comparable with the amounts found in brain. We also found that OFQ precusor mRNA levels were much higher in aorta or cultured VSMCs from SHRSP than those from WKY rats. In conclusion, the present study has shown that OFQ precusor mRNA is present in some peripheral tissues, especially in cardiovascular and reproductive system, suggesting that OFQ possibly involves in the regulation of cardiovascular and reproductive functions.
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Affiliation(s)
- Y Wei
- Cardiovascular Institute and Fu Wai Hospital, CAMS & PUMC, Beijing 100037
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Abstract
We discovered a series of novel behaviours of interactions between Ni2+ ion and human or bovine serum albumin. Our results indicated that there exist two closely neighbouring identical prior binding sites in the binding of human or bovine serum albumin with Ni2+ ions, not only one. It is very likely that, after the binding of the first Ni2+ ion, an induced slow conformational transition happens, which leads to the binding of the second Ni2+ ion and shows itself as a hysteretic effect for a process of non-enzymic protein binding with metal ions. As the concentrations of the 1:1 (molar ratio of Ni2+ ion to protein) system increase, an increasing hypochromic effect is observed. Such a hypochromic effect has not been reported previously; however, it is in accord with the mechanism of dipole-dipole interactions between the electric dipole transition moments of chromophores.
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Affiliation(s)
- Y Zhou
- Department of Chemistry, Nankai University, Tianjin, People's Republic of China
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