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Wang XD, Li X, Pan CL. Hemichorea in patients with temporal lobe infarcts: Two case reports. World J Clin Cases 2024; 12:806-813. [PMID: 38322679 PMCID: PMC10841122 DOI: 10.12998/wjcc.v12.i4.806] [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] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/08/2023] [Accepted: 01/08/2024] [Indexed: 01/25/2024] Open
Abstract
BACKGROUND Hemichorea and other hyperkinetic movement disorders are uncommon presentations of stroke and are usually secondary to deep infarctions affecting the basal ganglia and thalamus. Therefore, temporal ischemic lesions causing hemichorea are rare. We report the cases of two patients with acute ischemic temporal lobe infarct strokes that presented as hemichorea. CASE SUMMARY Patient 1: An 82-year-old woman presented with a 1-mo history of involuntary movement of the left extremity, which was consistent with hemichorea. Her diffusion-weighted imaging (DWI) revealed an acute ischemic stroke that predominantly affected the right temporal cortex, and magnetic resonance angiography of the head showed significant stenosis of the right middle cerebral artery (MCA). Treatment with 2.5 mg of olanzapine per day was initiated. When she was discharged from the hospital, her symptoms appeared to have improved compared with those previously observed. Twenty-seven days after the first admission, she was readmitted due to acute ischemic stroke. Computed tomography perfusion showed marked hypoperfusion in the right MCA territory. An emergency transfemoral cerebral angiogram was performed and showed severe stenosis in the M1 segment of the right MCA. After percutaneous transluminal angioplasty was successfully performed, abnormal movements or other neurologic problems did not occur. Patient 2: A 76-year-old man was admitted to our hospital for a 7-d history of right-upper-sided involuntary movements. DWI showed an acute patchy ischemic stroke in the left temporal lobe without basal ganglia involvement. Subsequent diffusion tensor imaging confirmed fewer white matter fiber tracts on the left side than on the opposite side. Treatment with 2.5 mg of olanzapine per day improved his condition, and he was discharged. CONCLUSION When acute hemichorea suddenly appears, temporal cortical ischemic stroke should be considered a possible diagnosis. In addition, hemichorea may be a sign of impending cerebral infarction with MCA stenosis.
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Affiliation(s)
- Xu-Dong Wang
- Department of Neurology, Puren Hospital Affiliated to Wuhan University of Science and Technology, Wuhan 430081, Hubei Province, China
- School of Medicine, Wuhan University of Science and Technology, Wuhan 430065, Hubei Province, China
| | - Xing Li
- Department of Neurology, Puren Hospital Affiliated to Wuhan University of Science and Technology, Wuhan 430081, Hubei Province, China
| | - Chun-Lian Pan
- Department of Neurology, Puren Hospital Affiliated to Wuhan University of Science and Technology, Wuhan 430081, Hubei Province, China
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Pan CL, Zhao J, Hu SX, Lei P, Zhao CR, Su YR, Cai WT, Zhang SS, Yan ZJ, Lu AD, Zhang B, Bai M. [Impact of VA-ECMO combined with IABP and timing on outcome of patients with acute myocardial infarction complicated with cardiogenic shock]. Zhonghua Xin Xue Guan Bing Za Zhi 2023; 51:851-858. [PMID: 37583334 DOI: 10.3760/cma.j.cn112148-20230706-00396] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Objective: To investigate the impact of combined use and timing of arterial-venous extracorporeal membrane oxygenation (VA-ECMO) with intra-aortic balloon pump (IABP) on the prognosis of patients with acute myocardial infarction complicated with cardiogenic shock (AMICS). Methods: This was a prospective cohort study, patients with acute myocardial infarction and cardiogenic shock who received VA-ECMO support from the Heart Center of Lanzhou University First Hospital from March 2019 to March 2022 in the registration database of the Chinese Society for Extracorporeal Life Support were enrolled. According to combination with IABP and time point, patients were divided into VA-ECMO alone group, VA-ECMO+IABP concurrent group and VA-ECMO+IABP non-concurrent group. Data from 3 groups of patients were collected, including the demographic characteristics, risk factors, ECG and echocardiographic examination results, critical illness characteristics, coronary intervention results, VA-ECMO related parameters and complications were compared among the three groups. The primary clinical endpoint was all-cause death, and the safety indicators of mechanical circulatory support included a decrease in hemoglobin greater than 50 g/L, gastrointestinal bleeding, bacteremia, lower extremity ischemia, lower extremity thrombosis, acute kidney injury, pulmonary edema and stroke. Kaplan-Meier survival curves were used to analyze the survival outcomes of patients within 30 days of follow-up. Using VA-ECMO+IABP concurrent group as reference, multivariate Cox regression model was used to evaluate the effect of the combination of VA-ECMO+IABP at different time points on the prognosis of AMICS patients within 30 days. Results: The study included 68 AMICS patients who were supported by VA-ECMO, average age was (59.8±10.8) years, there were 12 female patients (17.6%), 19 cases were in VA-ECMO alone group, 34 cases in VA-ECMO+IABP concurrent group and 15 cases in VA-ECMO+IABP non-concurrent group. The success rate of ECMO weaning in the VA-ECMO+IABP concurrent group was significantly higher than that in the VA-ECMO alone group and the VA-ECMO+IABP non-concurrent group (all P<0.05). Compared with the ECMO+IABP non-concurrent group, the other two groups had shorter ECMO support time, lower rates of acute kidney injury complications (all P<0.05), and lower rates of pulmonary edema complications in the ECMO alone group (P<0.05). In-hospital survival rate was significantly higher in the VA-ECMO+IABP concurrent group (28 patients (82.4%)) than in the VA-ECMO alone group (9 patients) and VA-ECMO+IABP non-concurrent group (7 patients) (all P<0.05). The survival rate up to 30 days of follow-up was also significantly higher surviving patients within were in the ECMO+IABP concurrent group (26 cases) than in VA-ECMO alone group (9 patients) and VA-ECMO+IABP non-concurrent group (4 patients) (all P<0.05). Multivariate Cox regression analysis showed that compared with the concurrent use of VA-ECMO+IABP, the use of VA-ECMO alone and non-concurrent use of VA-ECMO+IABP were associated with increased 30-day mortality in AMICS patients (HR=2.801, P=0.036; HR=2.985, P=0.033, respectively). Conclusions: When VA-ECMO is indicated for AMICS patients, combined use with IABP at the same time can improve the ECMO weaning rate, in-hospital survival and survival at 30 days post discharge, and which does not increase additional complications.
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Affiliation(s)
- C L Pan
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - J Zhao
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - S X Hu
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - P Lei
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - C R Zhao
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - Y R Su
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - W T Cai
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - S S Zhang
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - Z J Yan
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - A D Lu
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - B Zhang
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
| | - M Bai
- Heart Center, the First Hospital of Lanzhou University, Gansu Key Laboratory for Cardiovascular Diseases of Gansu Province, Lanzhou 730000, China
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Wang YM, Zhang J, Pan CL, Cao QY, Wang XY, Zhao AQ, Yao ZR, Han JW, Li M. Palmoplantar keratoderma: a new phenotype in patients with hypotrichosis resulted from lanosterol synthase gene mutations. J Eur Acad Dermatol Venereol 2022; 36:e842-e845. [PMID: 35689498 DOI: 10.1111/jdv.18315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 06/03/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Y M Wang
- Department of Dermatology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Institute of Dermatology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - J Zhang
- Department of Dermatology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Institute of Dermatology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - C L Pan
- Department of Dermatology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Institute of Dermatology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Q Y Cao
- Department of Dermatology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Institute of Dermatology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - X Y Wang
- Department of Dermatology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Institute of Dermatology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - A Q Zhao
- Department of Dermatology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Institute of Dermatology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Z R Yao
- Department of Dermatology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Institute of Dermatology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - J W Han
- Department of Dermatology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
| | - M Li
- Department of Dermatology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Institute of Dermatology, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Yang LG, Sung JY, Chow CW, Yeh CH, Cheng KT, Shi JW, Pan CL. Coding for stable transmission of W-band radio-over-fiber system using direct-beating of two independent lasers. Opt Express 2014; 22:26092-26097. [PMID: 25401641 DOI: 10.1364/oe.22.026092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrate experimentally Manchester (MC) coding based W-band (75 - 110 GHz) radio-over-fiber (ROF) system to reduce the low-frequency-components (LFCs) signal distortion generated by two independent low-cost lasers using spectral shaping. Hence, a low-cost and higher performance W-band ROF system is achieved. In this system, direct-beating of two independent low-cost CW lasers without frequency tracking circuit (FTC) is used to generate the millimeter-wave. Approaches, such as delayed self-heterodyne interferometer and heterodyne beating are performed to characterize the optical-beating-interference sub-terahertz signal (OBIS). Furthermore, W-band ROF systems using MC coding and NRZ-OOK are compared and discussed.
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Chow CW, Kuo FM, Shi JW, Yeh CH, Wu YF, Wang CH, Li YT, Pan CL. 100 GHz ultra-wideband (UWB) fiber-to-the-antenna (FTTA) system for in-building and in-home networks. Opt Express 2010; 18:473-478. [PMID: 20173867 DOI: 10.1364/oe.18.000473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Fiber-to-the-antenna (FTTA) system can be a cost-effective technique for distributing high frequency signals from the head-end office to a number of remote antenna units via passive optical splitter and propagating through low-loss and low-cost optical fibers. Here, we experimentally demonstrate an optical ultra-wideband (UWB) - impulse radio (IR) FTTA system for in-building and in-home applications. The optical UWB-IR wireless link is operated in the W-band (75 GHz - 110 GHz) using our developed near-ballistic unitraveling-carrier photodiode based photonic transmitter (PT) and a 10 GHz mode-locked laser. 2.5 Gb/s UWB-IR FTTA systems with 1,024 high split-ratio and transmission over 300 m optical fiber are demonstrated using direct PT modulation.
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Affiliation(s)
- C W Chow
- Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan
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Han WX, Zhang Q, Ma YT, Pan CL, Feng ZH. An impact rotary motor based on a fiber torsional piezoelectric actuator. Rev Sci Instrum 2009; 80:014701. [PMID: 19191453 DOI: 10.1063/1.3053166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A prototype small impact rotary motor has been fabricated based on a newly developed torsional actuator which is 15.0 mm long and 1.0 mm in diameter. The motor can rotate when it is powered with a saw-shaped voltage. The experimental results show that its angular speed is proportional to both the driving voltage's amplitude and the frequency under 1 kHz. The large nonlinearity occurs at higher driving frequency due to the resonance of the partial mechanical structure of the motor. The motor can rotate at a speed of 90 rpm with a saw-shaped driving voltage of 600 V(p.-p.) at 8 kHz, and produce a stall torque of 80 microN m with 1000 V(p.-p.) at 3 kHz.
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Affiliation(s)
- W X Han
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
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Abstract
The authors describe two patients with acute sensory ataxic neuropathy. Both had a profound loss of proprioception and generalized areflexia. High titers of monospecific anti-GD1b IgG antibody were detected in their sera during the acute phase. Sensory ataxia resolved within 2 weeks after the onset. Taken together with the induction of experimental sensory ataxic neuropathy sensitized with GD1b ganglioside, GD1b may be a target molecule for autoantibody in some patients with acute sensory ataxic neuropathy.
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Affiliation(s)
- C L Pan
- Department of Neurology, National Taiwan University Hospital, Taipei
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Abstract
Patients with peripheral neuropathy have symptoms involving small-diameter nociceptive nerves and elevated thermal thresholds. Nociceptive nerves terminate in the epidermis of the skin and are readily demonstrated with the neuronal marker, protein gene product 9.5 (PGP 9.5). To investigate the pathological characteristics of elevated thermal thresholds, we performed PGP 9.5 immunocytochemistry on 3 mm punch skin biopsies (the forearm and the leg) from 55 normal subjects and 35 neuropathic patients. Skin innervation was evaluated by quantifying epidermal nerve densities. Epidermal nerve densities were reduced in neuropathic patients compared to normal subjects. Epidermal nerve densities were variably correlated with thermal thresholds. The proportion of neuropathic patients with reduced epidermal nerve densities was larger than the proportion of neuropathic patients with elevated thermal thresholds. These results indicated that degeneration of epidermal nerve terminals preceded the elevation of thermal thresholds. Skin biopsy together with immunocytochemical demonstration of epidermal innervation offers a new approach to evaluate small-fiber sensory neuropathy.
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Affiliation(s)
- C L Pan
- Department of Neurology, National Taiwan University Hospital, Taipei
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Wang CL, Lin KH, Hwang TM, Chen YF, Wang SC, Pan CL. Mode-locked diode-pumped self-frequency-doubling neodymium yttrium aluminum borate laser. Appl Opt 1998; 37:3282-3285. [PMID: 18273283 DOI: 10.1364/ao.37.003282] [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] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
As far as we know this is the first report on picosecond green-light generation from an actively mode-locked diode-pumped self-doubling neodymium yttrium aluminum borate (NYAB) laser. The pulse width is approximately 100 ps and is limited by imperfect antireflection coating and the intracavity doubling effect. The green average output power of this laser for mode-locked operation was more than 12 times higher than that for the continuous wave NYAB laser. The polarization state of the laser can be switched from ordinary to extraordinary rays by displacement of the pump spot. The polarization ratio can be better than 200 without any intracavity polarization element.
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Affiliation(s)
- C L Wang
- Precision Instrument Development Center, 20 R&D Road VI, Science-Based Industrial Park, Hsinchu 300, Taiwan
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Shieh JM, Twu HM, Pan CL. Effects of intracavity dispersion on the starting dynamics of continuous-wave passively mode-locked Ti:sapphire/DDI lasers. Opt Lett 1996; 21:1058-1060. [PMID: 19876251 DOI: 10.1364/ol.21.001058] [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] [Indexed: 05/28/2023]
Abstract
Through analysis of transient autocorrelation traces, we show that intracavity dispersion significantly affects the number of initially oscillating modes as well as the buildup of passive mode locking in picosecond and femtosecond lasers.
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Abstract
We report, for the first time to our knowledge, generation of a tunable miltiterahertz modulation signal on an optical carrier directly from a single laser source. The modulation frequency, which can be tuned from 0.15 THz to more than 7 THz, is the beat note obtained by varying the spectral separation between the coaxial two-color output of a two-wavelength laser-diode array from 0.32 to 17 nm. The frequency characteristics of the terahertz beat note are determined with a noncollinear intensity autocorrelator.
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Wang CL, Chuang YH, Pan CL. Two-wavelength interferometer based on a two-color laser-diode array and the second-order correlation technique. Opt Lett 1995; 20:1071. [PMID: 19859427 DOI: 10.1364/ol.20.001071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Pu NW, Shieh JM, Lai Y, Pan CL. Starting dynamics of a cw passively mode-locked picosecond Ti:sapphire/DDI laser. Opt Lett 1995; 20:163-165. [PMID: 19859121 DOI: 10.1364/ol.20.000163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We show that, for a cw passively mode-locked picosecond Ti:sapphire/DDI laser, the first autocorrelation trace with negligible cw background occurs at a delay time of 20 mu;s, or 1600 round trips from the first relaxationoscillation peak. The trace suggests that the pulse consists of a primary pulse as short as 4.4 ps and of small secondary pulses that form a much wider pedestal of the trace, each containing approximately 50% of the photon energy. Nearly transform-limited approximately 5-ps-wide Gaussian pulses were observed at a delay time of 40 mu;s. After 45 mu;s, the optical spectrum broadened considerably, and the time-bandwidth product increased to 4 in the steady state (after 60 micros).
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Wang CL, Pan CL. Dual-wavelength actively mode-locked laser-diode array with an external grating-loaded cavity. Opt Lett 1994; 19:1456-1458. [PMID: 19855551 DOI: 10.1364/ol.19.001456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report the generation of dual-wavelength picosecond pulses by use of a commercial laser-diode array. The laser cavity incorporated a folded dispersive delay line with a V-shaped double-stripe mirror. The spectral separation of the laser output at the two wavelengths can be tuned from 2 to 11 nm. The actively mode-locked pulse widths at the two wavelengths were both 29 ps. Cross-correlation and power-spectrum measurements indicated that the two-color pulses were synchronized with an absolute timing jitter of less than 1 ps (instrument limited).
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Pan CL, Hwang CD, Kuo JC, Shieh JM, Wu KH. Birefringence-induced spectral features in continuous-wave and passively mode-locked Ti:sapphire lasers. Opt Lett 1992; 17:1547. [PMID: 19798243 DOI: 10.1364/ol.17.001547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Pan CL, Hwang CD, Kuo JC, Shieh JM, Wu KH. Effect of dye concentration on picosecond and femtosecond cw passively mode-locked Ti:sapphire/DDI lasers. Opt Lett 1992; 17:1444. [PMID: 19798208 DOI: 10.1364/ol.17.001444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Pan CL, Kuo JC, Hwang CD, Shieh JM, Lai Y, Chang CS, Wu KH. Buildup dynamics of the spectrum and the average output power of a homogeneously broadened continuous-wave Ti:sapphire laser. Opt Lett 1992; 17:994-996. [PMID: 19794698 DOI: 10.1364/ol.17.000994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Chien PY, Pan CL. Triangularly phase-modulated optical fiber ring resonator sensor. Appl Opt 1992; 31:2776-2779. [PMID: 20725209 DOI: 10.1364/ao.31.002776] [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] [Indexed: 05/29/2023]
Abstract
An optical fiber ring resonatory sensor system has been demonstrated by applying a triangular phase modulation signal to a fiber loop. The dynamic range for detection of optical phase change is 2pi. The sensor is linear within this range. The minimum detectable optical phase change is 1.5 x10(-4) rad/Hz((1/2)).
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Chien PY, Pan CL. Two-frequency fiber-optic sensor system using high-birefringence optical fiber. Appl Opt 1992; 31:1407-1411. [PMID: 20720771 DOI: 10.1364/ao.31.001407] [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] [Indexed: 05/29/2023]
Abstract
A fiber sensor system based on high-birefringence optical fiber and a frequency-stabilized He-Ne Zeeman laser (lambda = 0.6328 microm) has been demonstrated. The small path-length changes of interest are extracted from the amplitude or phase of the laser beat frequency by using either the phase-sensitive detection or the phase-demodulation technique. A minimum detectable optical phase delay of 1.5 x 10(-6) rad/Hz((1/2)) or 17 x 10(-6) rad/Hz((1/2)) has been achieved.
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Abstract
A scale-factor-stabilized fiber-optic gyroscope by deep phase modulation is demonstrated. There are two servo loops included in this system. The first servo loop is used for stabilization of the light intensity output of the fiber-optic gyroscope. The second loop is used to stabilize the phase-modulation index. The third-harmonic frequency of the phase-modulation signal is used for detection of the Sagnac phase shift by the lock-in technique.
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Kuo JC, Shieh JM, Hwang CD, Chang CS, Pan CL, Wu KH. Pulse-forming dynamics of a cw passively mode-locked Ti:sapphire/DDI laser. Opt Lett 1992; 17:334-336. [PMID: 19784319 DOI: 10.1364/ol.17.000334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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22
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Chien PY, Pan CL, Chang LW. Triangular phase-modulation approach to an open-loop fiber-optic gyroscope. Opt Lett 1991; 16:1701-1703. [PMID: 19784114 DOI: 10.1364/ol.16.001701] [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] [Indexed: 05/28/2023]
Abstract
A new approach to an open-loop, all-fiber gyroscope with a wide dynamic range and a linear scale factor is described. For signal processing, the Sagnac phase shift is converted into a phase shift in the low-frequency electrical signal by using a triangular phase-modulation waveform followed by gate switching. The basic principle of this technique and experimental results are reported.
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Kuo JC, Chang CS, Pan CL. Buildup of steady-state picosecond pulses in an actively mode-locked laser-diode array. Opt Lett 1991; 16:1328-1330. [PMID: 19776960 DOI: 10.1364/ol.16.001328] [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] [Indexed: 05/28/2023]
Abstract
We have studied experimentally the temporal and spectral characteristics of an actively mode-locked laserdiode array in an external cavity as it evolves to the steady state. It is found that the buildup time to steadystate picosecond pulses takes less than 45 round trips. The number of clusters of the longitudinal-mode spectrum reduces during the evolution and finally approaches a steady-state spectral distribution with the pulse energy mainly distributed among a few clusters near the line center.
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Abstract
We propose and demonstrate a multiplexed fiber-optic sensor system using a dual-slope (triangular) frequency-modulated laser source. The restrictions in the selection of beat frequencies of the multiplexed sensors in previous studies that employed ramp modulation wave forms are eliminated.
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Abstract
We demonstrate an active laser heterodyne interferometer which can automatically compensate environmental disturbances and is capable of precision displacement measurement. Two Zeeman He-Ne lasers were employed. Laser II was used as the light source to stabilize the interferometer by using a piezomirror in a feedback loop. The hetereodyne signal of the two lasers was used to directly calibrate mirror displacement, with the wavelength of laser I tuned to compensate change in the interference signal due to displacement only. Separation of the contributions to the interference signal from displacement and external disturbances was accomplished by using polarization optics. This interferometer was used to measure the hysteresis of a piezoelectric transducer (PZT) over a dynamic range of 0.5 microm with a resolution of +/-0.8 nm.
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Chien PY, Pan CL. Scale-factor-stabilized fiber-optic gyroscope based on a spectrum-broadened laser-diode source. Opt Lett 1991; 16:426-428. [PMID: 19773955 DOI: 10.1364/ol.16.000426] [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] [Indexed: 05/28/2023]
Abstract
A spectrum-broadened laser-diode source that uses the optical feedback and current-modulation effects has been adopted as the light source of a fiber-optic gyroscope to reduce the inherent phase noise. The scale factor of the gyroscope has also been stabilized.
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Abstract
A novel fiber-optic gyroscope with a single-mode diode laser as the light source and two polarization scramblers as time-varying depolarizers is demonstrated. This arrangement reduces the nonreciprocal phase noise induced by the cross coupling between polarization modes in single-mode fibers. The experimental results show that a phase-noise reduction factor of 18 can be achieved.
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Kuo JC, Pan CL. Buildup of steady-state subpicosecond and femtosecond pulses in a colliding-pulse mode-locked ring dye laser. Opt Lett 1990; 15:1297-1299. [PMID: 19771071 DOI: 10.1364/ol.15.001297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We show for the first time, to our knowledge, that the buildup time to steady-state femtosecond pulses in a typical colliding-pulse mode-locked dye laser (lambda = 620 nm) with compensating prisms is 15 microsec after the pulses have been completely modulated. For a similar laser without the compensating prisms, the buildup time is 40 microsec and exhibits interesting oscillatory behavior in the initial stage.
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Chen SM, Pan RP, Pan CL. Interferometric measurements of the thickness of nematic liquid crystal films with a free surface. Appl Opt 1989; 28:4969-4971. [PMID: 20555980 DOI: 10.1364/ao.28.004969] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We demonstrate two interferometric methods for measuring the thickness of nematic liquid crystal films with a free surface. The accuracy of either method is better than +/-1 %.
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Dunny GM, Krug DA, Pan CL, Ledford RA. Identification of cell wall antigens associated with a large conjugative plasmid encoding phage resistance and lactose fermentation ability in lactic streptococci. Biochimie 1988; 70:443-50. [PMID: 3139064 DOI: 10.1016/0300-9084(88)90219-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In order to begin to analyze the gene products encoded by phage resistance plasmids in lactic streptococci, we identified phage-resistance plasmids by screening resistant strains from commercial starter cultures for the ability to carry out unselected cotransfer, by conjugation, of phage resistance with lactose fermentation ability (lac+). In this fashion, we identified a large (90 kilobases) plasmid, pCLP51R, that encodes the lac+ marker, resistance to a lytic phage called LP10G (1pr+), high-frequency conjugal donor ability (hft+), and clumpy growth of host bacteria in broth culture (clu+). The mechanism of resistance conferred by this plasmid appears to involve interference with a step in the phage replication cycle that occurs after the initial attachment of the phage. Polyacrylamide gel electrophoresis of cell surface extracts of isogenic strains, carrying or lacking pCLP51R, combined with immunoblotting analysis, showed that there were several plasmid-related differences in the banding pattern of low molecular weight proteins and that the plasmid resulted in production of several unique antigenic polypeptides in the size range of 15-30 kd, as well as modification of chromosomally encoded antigens to different molecular weight forms.
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Affiliation(s)
- G M Dunny
- Department of Microbiology, Immunology and Parasitology, Cornell-University, Ithaca, NY 14853
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Pan CL, Jean PY. Stabilization of internal-mirror He-Ne lasers. Appl Opt 1986; 25:2126. [PMID: 18231465 DOI: 10.1364/ao.25.002126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Pan CL, Chen SH, Liao H. Quasistatic-electric- and optical-field-induced birefringence and nonlinear-optical diffraction effects in a nematic-liquid-crystal film. Phys Rev A Gen Phys 1986; 33:4312-4318. [PMID: 9897173 DOI: 10.1103/physreva.33.4312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Pan CL, Jean PY. Simultaneous output power and frequency stabilization of a Zeeman He-Ne laser. Appl Opt 1986; 25:1375-1376. [PMID: 20448707 DOI: 10.1364/ao.25.001375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Pan CL, Jean PY, Kuo CC, Hsieh TC, Lei TF. Sensitivity of frequency stability of two-mode internal-mirror He-Ne lasers to misalignment of polarizing optics. Appl Opt 1985; 24:3430-3431. [PMID: 20445651 DOI: 10.1364/ao.24.003430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Chen SH, Pan CL, Chen YM, Liao HH. Quasi-static electric-field-enhanced diffraction effects in a nematic liquid-crystal film. Opt Lett 1985; 10:493-495. [PMID: 19730462 DOI: 10.1364/ol.10.000493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A quasi-static electric field can enhance laser-induced diffraction rings from a nematic liquid-crystal film. This phenomenon is shown to be the combined result of the critical behavior of the sample at the Freedericksz transition and the nonlinear coupling of the optical and quasi-static electric fields.
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Pan CL, Prodan JV, Fairbank WM, She CY. Detection of individual atoms in helium buffer gas and observation of their real-time motion. Opt Lett 1980; 5:459-461. [PMID: 19701270 DOI: 10.1364/ol.5.000459] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Single atoms are detected and their motion measured for the first time to our knowledge by the fluorescence photon- burst method in the presence of large quantities of buffer gas. A single-clipped digital correlator records the photon burst in real time and displays the atom's transit time across the laser beam. A comparison is made of the special requirements for single-atom detection in vacuum and in a buffer gas. Finally, the probability distribution of the bursts from many atoms is measured. It further proves that the bursts observed on resonance are due to single atoms and pot simply to noise fluctuations.
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Affiliation(s)
- C L Pan
- Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA
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