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Vaughan M, Michailow W, Salih M, Li L, Beere H, Ritchie DA, Linfield EH, Davies AG, Cunningham JE. Directed delivery of terahertz frequency radiation from quantum cascade lasers within a dry 3He dilution refrigerator. Rev Sci Instrum 2022; 93:113906. [PMID: 36461439 DOI: 10.1063/5.0102553] [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] [Received: 06/10/2022] [Accepted: 10/08/2022] [Indexed: 06/17/2023]
Abstract
We present a scheme for the full integration of terahertz (THz) frequency quantum cascade lasers (QCLs) within a dilution refrigerator in order to provide a directed delivery of THz power into the sample space. We describe a successful operation of a 2.68 THz QCL located on the pulse tube cooler stage of the refrigerator, with its output coupled onto a two-dimensional electron gas (2DEG) located on a milli-kelvin sample stage via hollow metal waveguides and Hysol thermal isolators, achieving a total loss from QCL to the sample of ∼-9 dB. The thermal isolators limit heat leaks to the sample space, with a base temperature of ∼210 mK being achieved. We observe cyclotron resonance (CR) induced in the 2DEG by the QCL and explore the heating impact of the QCL on all stages of the refrigerator. The CR effect induced by the THz QCL is observable at electron temperatures as low as ∼430 mK. The results show a viable route for the exploitation of THz QCLs within the environment of a dilution refrigerator and for the THz power delivery in very low-temperature (<0.5 K) condensed matter experiments.
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Affiliation(s)
- M Vaughan
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
| | - W Michailow
- Cavendish Laboratory, University of Cambridge, Cambridge, Cambridgeshire CB3 0HE, United Kingdom
| | - M Salih
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
| | - L Li
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
| | - H Beere
- Cavendish Laboratory, University of Cambridge, Cambridge, Cambridgeshire CB3 0HE, United Kingdom
| | - D A Ritchie
- Cavendish Laboratory, University of Cambridge, Cambridge, Cambridgeshire CB3 0HE, United Kingdom
| | - E H Linfield
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
| | - A G Davies
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
| | - J E Cunningham
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, West Yorkshire LS2 9JT, United Kingdom
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Park SJ, Zonetti S, Parker-Jervis RS, Wu J, Wood CD, Li LH, Davies AG, Linfield EH, Sydoruk O, Cunningham JE. Terahertz magnetoplasmon resonances in coupled cavities formed in a gated two-dimensional electron gas. Opt Express 2021; 29:12958-12966. [PMID: 33985041 DOI: 10.1364/oe.414178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
We report on both experiments and theory of low-terahertz frequency range (up to 400 GHz) magnetoplasmons in a gated two-dimensional electron gas at low (<4K) temperatures. The evolution of magnetoplasmon resonances was observed as a function of magnetic field at frequencies up to ∼400 GHz. Full-wave 3D simulations of the system predicted the spatial distribution of plasmon modes in the 2D channel, along with their frequency response, allowing us to distinguish those resonances caused by bulk and edge magnetoplasmons in the experiments. Our methodology is anticipated to be applicable to the low temperature (<4K) on-chip terahertz measurements of a wide range of other low-dimensional mesoscopic systems.
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Meng K, Park SJ, Li LH, Bacon DR, Chen L, Chae K, Park JY, Burnett AD, Linfield EH, Davies AG, Cunningham JE. Tunable broadband terahertz polarizer using graphene-metal hybrid metasurface. Opt Express 2019; 27:33768-33778. [PMID: 31878438 DOI: 10.1364/oe.27.033768] [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: 09/06/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
We demonstrate an electrically tunable polarizer for terahertz (THz) frequency electromagnetic waves formed from a hybrid graphene-metal metasurface. Broadband (>3 THz) polarization-dependent modulation of THz transmission is demonstrated as a function of the graphene conductivity for various wire grid geometries, each tuned by gating using an overlaid ion gel. We show a strong enhancement of modulation (up to ∼17 times) compared to graphene wire grids in the frequency range of 0.2-2.5 THz upon introduction of the metallic elements. Theoretical calculations, considering both plasmonic coupling and Drude absorption, are in good agreement with our experimental findings.
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Meng K, Park SJ, Burnett AD, Gill T, Wood CD, Rosamond M, Li LH, Chen L, Bacon DR, Freeman JR, Dean P, Ahn YH, Linfield EH, Davies AG, Cunningham JE. Increasing the sensitivity of terahertz split ring resonator metamaterials for dielectric sensing by localized substrate etching. Opt Express 2019; 27:23164-23172. [PMID: 31510599 DOI: 10.1364/oe.27.023164] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/11/2019] [Indexed: 05/18/2023]
Abstract
We demonstrate a significant enhancement in the sensitivity of split ring resonator terahertz metamaterial dielectric sensors by the introduction of etched trenches into their inductive-capacitive gap area, both through finite element simulations and in experiments performed using terahertz time-domain spectroscopy. The enhanced sensitivity is demonstrated by observation of an increased frequency shift in response to overlaid dielectric material of thicknesses up to 18 µm deposited on to the sensor surface. We show that sensitivity to the dielectric is enhanced by a factor of up to ∼2.7 times by the incorporation of locally etched trenches with a depth of ∼3.4 µm, for example, and discuss the effect of the etching on the electrical properties of the sensors. Our experimental findings are in good agreement with simulations of the sensors obtained using finite element methods.
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Dodoo-Amoo NA, Saeed K, Mistry D, Khanna SP, Li L, Linfield EH, Davies AG, Cunningham JE. Non-universality of scaling exponents in quantum Hall transitions. J Phys Condens Matter 2014; 26:475801. [PMID: 25351842 DOI: 10.1088/0953-8984/26/47/475801] [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: 06/04/2023]
Abstract
We have investigated experimentally the scaling behaviour of quantum Hall transitions in GaAs/AlGaAs heterostructures of a range of mobility, carrier concentration, and spacer layer width. All three critical scaling exponents γ, κ and p were determined independently for each sample. We measure the localization length exponent to be γ ≈ 2.3, in good agreement with expected predictions from scaling theory, but κ and p are found to possess non-universal values. Results obtained for κ range from κ = 0.16 ± 0.02 to κ = 0.67 ± 0.02, and are found to be Landau level (LL) dependent, whereas p is found to decrease with increasing sample mobility. Our results demonstrate the existence of two transport regimes in the LL conductivity peak; universality is found within the quantum coherent transport regime present in the tails of the conductivity peak, but is absent within the classical transport regime found close to the critical point at the centre of the conductivity peak. We explain these results using a percolation model and show that the critical scaling exponent depends on certain important length scales that correspond to the microscopic description of electron transport in the bulk of a two-dimensional electron system.
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Affiliation(s)
- N A Dodoo-Amoo
- School of Electronic and Electrical Engineering, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT,UK
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Krishnamoorthy AV, Zheng X, Feng D, Lexau J, Buckwalter JF, Thacker HD, Liu F, Luo Y, Chang E, Amberg P, Shubin I, Djordjevic SS, Lee JH, Lin S, Liang H, Abed A, Shafiiha R, Raj K, Ho R, Asghari M, Cunningham JE. A low-power, high-speed, 9-channel germanium-silicon electro-absorption modulator array integrated with digital CMOS driver and wavelength multiplexer. Opt Express 2014; 22:12289-12295. [PMID: 24921347 DOI: 10.1364/oe.22.012289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We demonstrate the first germanium-silicon C-band electro-absorption based waveguide modulator array and echelle-grating-based silicon wavelength multiplexer integrated with a digital CMOS driver circuit. A 9-channel, 10Gbps SiGe electro-absorption wavelength-multiplexed modulator array consumed a power of 5.8mW per channel while being modulated at 10.25Gbps by 40nm CMOS drivers delivering peak-to-peak voltage swings of 2V, achieving a modulation energy-efficiency of ~570fJ/bit including drivers. Performance up to 25Gbps on a single-channel SiGe modulator and CMOS driver is also reported.
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Cunningham JE, Bauza CE, Brown ET, Alberg AJ, Kistner-Griffin E, Spruill IJ, Bryant DC, Charles KD, Esnaola NF, Jefferson MS, Whitfield KE, Kramer RM, Bolick S, Hurley D, Mosley C, Hazelton TR, Bea VJ, Burshell DR, Ford ME. Abstract P5-12-11: Evaluating overweight/obesity and physical activity rates in an ethnically diverse sample of breast cancer survivors. Cancer Res 2013. [DOI: 10.1158/0008-5472.sabcs13-p5-12-11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Overweight/obesity are associated with higher risk of recurrence and poorer survival after a breast cancer diagnosis. According to The Centers for Disease Control and Prevention (CDC) Behavioral Risk Factor Surveillance System (BRFSS) data for 2011, in South Carolina, 74.6% of African American (AA) and 62.5% of European American (EA) adult women are overweight/obese.
Methods: Prevalence of overweight/obesity and level of physical activity (PA) are evaluated in an ongoing, ethnically-diverse statewide study of adult women with recently-diagnosed invasive breast cancer. Participants are identified within 18 months post-diagnosis through the South Carolina Central Cancer Registry (SCCCR). Participants who opt in to the study are interviewed via telephone and self-report their body weight, height and physical activities. Published CDC body mass index (BMI) categories and 2008 PA guidelines are used to characterize BMI and PA guideline adherence.
Results: During the first 10 months of the study, 98 women (56 AA, 42 EA) were interviewed and results analyzed. Age: Participants ranged in age from 26 to 90 years (mean 60.2 years, SD 12.8), with AAs 3.7 years younger than EAs (p = 0.16). Education: Almost two-thirds of participants (61%) had more than a high school diploma (55% of AAs and 69% of EAs, p = 0.29). BMI: The BMI mean was 30.1 (SD 6.6, median 26.6) which was significantly higher in AAs (31.3 compared to 28.6 in EAs, p = 0.04). Among all women combined, 79% were overweight/obese, with no statistically significant difference by race (p = 0.15). Overweight was equally frequent among AAs (34%) and EAs (33%). However, obesity was more frequent among AAs (50%) than EAs (38%). Physical Activity (PA): CDC guideline adherence of ≥150 minutes/week of moderate PA was reported by only 32% of participants (25% of AAs, 41% of EAs; p = 0.10). A total of 28% reported no physical activity (30% of AAs and 24% of EAs, p = 0.47). Meeting CDC PA guidelines was associated with lower risk of being overweight/obese (OR = 0.41, p = 0.080), but this was statistically significant only among EAs (OR = 0.21, p = 0.035).
Conclusions: Prevalence of overweight/obesity is high, regardless of ethnicity, and physical activity is low in this group of breast cancer survivors. It is imperative to identify effective strategies to reduce overweight and obesity, and to increase PA, in order to reduce the risk of recurrence and improve survival. In this regard, the study team is developing an National Institutes of Health R01 grant application to evaluate the effectiveness of an intervention, which combines a reduced-energy diet with increased PA, in reducing levels of cancer-related inflammatory biomarkers linked to breast cancer recurrence. Updated results of our on-going study, including associations of BMI and PA with breast cancer stage and phenotype, will be presented.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-12-11.
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Affiliation(s)
- JE Cunningham
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - CE Bauza
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - ET Brown
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - AJ Alberg
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - E Kistner-Griffin
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - IJ Spruill
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - DC Bryant
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - KD Charles
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - NF Esnaola
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - MS Jefferson
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - KE Whitfield
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - RM Kramer
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - S Bolick
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - D Hurley
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - C Mosley
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - TR Hazelton
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - VJ Bea
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - DR Burshell
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
| | - ME Ford
- Medical University of South Carolina (MUSC), Charleston, SC; MUSC Hollings Cancer Center, Charleston, SC; Morehouse School of Medicine, Atlanta, GA; Temple University School of Medicine, Philadelphia, PA; Duke University, Durham, NC; South Carolina Department of Health and Environmental Control, South Carolina Central Cancer Registry, Columbia, SC
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Wood CD, Mistry D, Li LH, Cunningham JE, Linfield EH, Davies AG. On-chip terahertz spectroscopic techniques for measuring mesoscopic quantum systems. Rev Sci Instrum 2013; 84:085101. [PMID: 24007101 DOI: 10.1063/1.4816736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We present the self-aligned fabrication of on-chip devices in which waveguides, incorporating integrated photoconductive switches, are combined with two-dimensional electron systems to allow probing of the ultrafast (terahertz frequency range) properties of confined semiconductor systems, both at cryogenic temperatures and in high magnetic fields. We demonstrate the direct injection of on-chip terahertz pulses into the mesoscopic system by femtosecond, near infra-red laser excitation of in-plane photoconductive switches formed on an epitaxially grown, low-temperature GaAs layer, which is integrated monolithically with a GaAs∕AlGaAs heterostructure containing a two-dimensional electron system. Both the input and output terahertz signals of an on-chip waveguide are sampled by altering dynamically the photoconductive excitation∕detection arrangement in situ on a single device. We also demonstrate a new method for sub-Kelvin excitation and detection of on-chip terahertz frequency radiation in a (3)He∕(4)He dilution refrigerator that allows the photocurrent and detected terahertz transient to be mapped as function of the near-infrared excitation position at the emitter and the detector, respectively. Furthermore, we demonstrate transmission of terahertz transients through a two-dimensional electron system in a coplanar waveguide under magnetic field at temperatures as low as 200 mK.
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Affiliation(s)
- C D Wood
- School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom
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Zilkie AJ, Seddighian P, Bijlani BJ, Qian W, Lee DC, Fathololoumi S, Fong J, Shafiiha R, Feng D, Luff BJ, Zheng X, Cunningham JE, Krishnamoorthy AV, Asghari M. Power-efficient III-V/silicon external cavity DBR lasers. Opt Express 2012; 20:23456-23462. [PMID: 23188309 DOI: 10.1364/oe.20.023456] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report the design and characterization of external-cavity DBR lasers built with a III-V-semiconductor reflective-SOA with spot-size converter edge-coupled to SOI waveguides containing Bragg grating mirrors. The un-cooled lasers have wall-plug-efficiencies of up to 9.5% at powers of 6 mW. The lasers are suitable for making power efficient, hybrid WDM transmitters in a CMOS-compatible SOI optical platform.
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Affiliation(s)
- A J Zilkie
- Kotura Inc., 2630 Corporate Place, Monterey Park, California 91754, USA.
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Dean P, Burnett AD, Tych K, Khanna SP, Lachab M, Cunningham JE, Linfield EH, Davies AG. Measurement and analysis of the diffuse reflectance of powdered samples at terahertz frequencies using a quantum cascade laser. J Chem Phys 2011; 134:134304. [DOI: 10.1063/1.3575201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tan DTH, Ikeda K, Zamek S, Mizrahi A, Nezhad MP, Krishnamoorthy AV, Raj K, Cunningham JE, Zheng X, Shubin I, Luo Y, Fainman Y. Wide bandwidth, low loss 1 by 4 wavelength division multiplexer on silicon for optical interconnects. Opt Express 2011; 19:2401-2409. [PMID: 21369058 DOI: 10.1364/oe.19.002401] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We demonstrate an add/drop filter based on coupled vertical gratings on silicon. Tailoring of the channel bandwidth and wavelength is experimentally demonstrated. The concept is extended to implement a 1 by 4 wavelength division multiplexer with 6 nm channel separation, 3 nm bandwidth, a flat top response with < 0.8 dB ripple within the 3 dB passband, 1 dB insertion loss and 16 dB crosstalk suppression. The device is ultracompact, having a footprint < 2 X 10(-9)/2.
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Affiliation(s)
- D T H Tan
- Dept of Electrical and Computer Engineering, University of California San Diego, 9500 Gilman Dr La Jolla, California 92093-0407, USA
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Heiney SP, McWayne J, Cunningham JE, Hazlett LJ, Parrish RS, Bryant LH, Vitoc C, Jansen K. Quality of life and lymphedema following breast cancer. Lymphology 2007; 40:177-184. [PMID: 18365532] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The aim of the study was to compare Quality of Life (QOL) of breast cancer patients with and without secondary lymphedema (SLE) using a cross-sectional design with a convenience sample. Research packets were mailed to 2088 breast cancer patients (BrCaPt). The QOL component of the study used the Quality of Life Instrument --Breast Cancer Patient Version for data collection. The sample (n = 537) was 12.9% African-American/Hispanic/Other (AA) and 87.1% European-American (EA). One hundred and twenty-two women (22.7%) reported SLE. Overall and subscale means were computed and ANOVA was determined for seven variables: age, marital status, educational level, race, type of surgery, time since diagnosis, and SLE. Women without SLE had a higher overall mean QOL score compared to women with SLE (p= 0.02). Women with a greater than high school education had a higher mean QOL score compared to women with high school or less education (p=0.05). SLE patients had poorer QOL in the physical (p<0.001), and social (p=0.004) subscales. Older women had a higher overall QOL compared to younger women (p<0.001). These results provide insight into the impact of SLE on women's QOL and pinpoint that physical and social well being are negatively influenced by SLE.
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Affiliation(s)
- S P Heiney
- Palmetto Health South Carolina Cancer Center, Columbia, SC 29203, USA.
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Cunningham JE, Beckman D, Zheng X, Huang D, Sze T, Krishnamoorthy AV. PAM-4 Signaling over VCSELs with 0.13microm CMOS Chip Technology. Opt Express 2006; 14:12028-12038. [PMID: 19529630 DOI: 10.1364/oe.14.012028] [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: 05/27/2023]
Abstract
We present results for VCSEL based links operating PAM-4 signaling using a commercial 0.13microm CMOS technology. We perform a complete link analysis of the Bit Error Rate, Q factor, random and deterministic jitter by measuring waterfall curves versus margins in time and amplitude. We demonstrate that VCSEL based PAM-4 can match or even improve performance over binary signaling under conditions of a bandwidth limited, 100meter multi-mode optical link at 5Gbps. We present the first sensitivity measurements for optical PAM-4 and compare it with binary signaling. Measured benefits are reconciled with information theory predictions.
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Schulz M, Liese AD, Boeing H, Cunningham JE, Moore CG, Kroke A. Associations of short-term weight changes and weight cycling with incidence of essential hypertension in the EPIC-Potsdam Study. J Hum Hypertens 2004; 19:61-7. [PMID: 15343355 DOI: 10.1038/sj.jhh.1001776] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [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: 11/09/2022]
Abstract
The aim of this study was to examine the relationships of short-term weight gain, weight loss, and weight cycling on the odds of developing hypertension. Normotensive middle-aged German men and women (n=12,362) of the European Prospective Investigation into Cancer and Nutrition-Potsdam Study were assigned to categories of 2-year short-term weight changes that were self-reported to have occurred prior to recruitment into the study (gain only, loss only, weight cycling, stable). After 2 years of follow-up after recruitment, 180 cases of incident essential hypertension were identified. In logistic regression models, odds ratios were estimated for the associations between short-term weight changes and risk of developing hypertension. Obesity status (BMI>or=30 or BMI<30 kg/m2) modified the associations between short-term weight change and incidence of diagnosed hypertension. Among obese individuals, short-term weight gain occurring during the 2 years prior to recruitment (OR=2.79, 95% CI 1.19-6.56), weight loss (OR=6.74, 95% CI 2.58-17.6) and weight cycling (OR=4.29, 95% CI 1.55-11.9) were strongly positively associated with incident hypertension, adjusted for age and gender, compared to obese individuals with short-term stable weight. No significant associations between short-term weight changes and risk of diagnosed hypertension were detected among non-obese individuals. Short-term weight changes appeared to present strong risk factors for developing hypertension among obese individuals. The effect seen for weight cycling supports the hypothesis that weight cycling increases the risk of hypertension. The finding for short-term weight loss may be explained by subsequent weight regain and needs further investigation.
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Affiliation(s)
- M Schulz
- Department of Epidemiology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany.
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Abstract
Macrobiotics is one of the most popular alternative or complementary comprehensive lifestyle approaches to cancer. The centerpiece of macrobiotics is a predominantly vegetarian, whole-foods diet that has gained popularity because of remarkable case reports of individuals who attributed recoveries from cancers with poor prognoses to macrobiotics and the substantial evidence that the many dietary factors recommended by macrobiotics are associated with decreased cancer risk. Women consuming macrobiotic diets have modestly lower circulating estrogen levels, suggesting a lower risk of breast cancer. This may be due in part to the high phytoestrogen content of the macrobiotic diet. As with most aspects of diet in cancer therapy, there has been limited research evaluating the effectiveness of the macrobiotic diet in alleviating suffering or prolonging survival of cancer patients. The few studies have compared the experience of cancer patients who tried macrobiotics with expected survival rates or assembled series of cases that may justify more rigorous research. On the basis of available evidence and its similarity to dietary recommendations for chronic disease prevention, the macrobiotic diet probably carries a reduced cancer risk. However, at present, the empirical scientific basis for or against recommendations for use of macrobiotics for cancer therapy is limited. Any such recommendations are likely to reflect biases of the recommender. Because of its popularity and the compelling evidence that dietary factors are important in cancer etiology and survival, further research to clarify whether the macrobiotic diet or similar dietary patterns are effective in cancer prevention and treatment is warranted.
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Affiliation(s)
- L H Kushi
- Program in Nutrition, Department of Health & Behavior Studies, Teachers College, Columbia University, New York, NY, USA.
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Newman LA, Sahin AA, Cunningham JE, Bondy ML, Mirza NQ, Vlastos GS, Whitman GJ, Brown H, Buchholz TA, Lee MH, Singletary SE. A case-control study of unilateral and bilateral breast carcinoma patients. Cancer 2001; 91:1845-53. [PMID: 11346865 DOI: 10.1002/1097-0142(20010515)91:10<1845::aid-cncr1205>3.0.co;2-z] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Women with unilateral breast carcinoma are at increased risk for developing contralateral disease. The clinical significance of bilateral breast carcinoma has not been fully defined, and the subset of patients who may benefit from medical or surgical risk-reduction intervention has not yet been characterized. The purpose of this study was to evaluate risk factors and outcomes for bilateral breast carcinoma. METHODS A subject group of 70 bilateral breast carcinoma patients (62% metachronous) was matched by age and survival interval with a control group of 70 unilateral breast carcinoma patients. Median follow-up was 103 months. RESULTS Eighty-two percent of the unilateral patients and 80% of the bilateral patients had Stage I or II disease at diagnosis. Median age at presentation was 53 years. In the bilateral group, the contralateral cancer was diagnosed at the same or earlier stage than the first cancer in 87% of cases. Bilateral patients were significantly more likely to have multicentric disease and to have a positive family history for breast carcinoma compared with the unilateral group. There were no significant differences regarding history of exogenous hormone exposure, lobular histology, hormone-receptor status, or HER-2/neu expression. Five-year disease-free survival was 94% for the unilateral breast carcinoma patients and 91% for the bilateral breast carcinoma patients (P = 0.16). CONCLUSIONS Survival for patients with bilateral breast carcinoma is similar to that of patients with unilateral disease; however, prophylactic risk-reduction intervention for the contralateral breast should be considered in patients who have multicentric unilateral disease or a positive family history for breast carcinoma.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Breast Neoplasms/mortality
- Breast Neoplasms/pathology
- Carcinoma, Ductal, Breast/mortality
- Carcinoma, Ductal, Breast/pathology
- Carcinoma, Intraductal, Noninfiltrating/mortality
- Carcinoma, Intraductal, Noninfiltrating/pathology
- Carcinoma, Lobular/mortality
- Carcinoma, Lobular/pathology
- Case-Control Studies
- Female
- Follow-Up Studies
- Humans
- Middle Aged
- Neoplasm Metastasis
- Neoplasm Staging
- Prognosis
- Risk Factors
- Survival Rate
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Affiliation(s)
- L A Newman
- Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston 77030, USA
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Cho SH, Kärtner FX, Morgner U, Ippen EP, Fujimoto JG, Cunningham JE, Knox WH. Generation of 90-nJ pulses with a 4-MHz repetition-rate Kerr-lens mode-locked Ti:Al(2)O(3) laser operating with net positive and negative intracavity dispersion. Opt Lett 2001; 26:560-562. [PMID: 18040385 DOI: 10.1364/ol.26.000560] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We demonstrate the generation of high-energy pulses by using a low-repetition-rate Kerr-lens mode-locked laser. Repetition rates as low as 4 MHz were achieved with a long, multiple-pass cavity and a semiconductor saturable Bragg reflector. The laser generated pulses of 55-fs duration with a pulse energy of 48 nJ when it was mode locked in the net negative dispersion regime. Mode locking in the positive dispersion regime reduces instabilities and enables pulses to have durations of 80 fs and energies as high as 90 nJ. This is, to our knowledge, the highest pulse energy and the lowest repetition rate ever generated directly from a femtosecond laser resonator without cavity dumping.
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Cunningham JE, Greenlaw D, Erskine JL, Layton RP, Flynn CP. Coupling of electronically excited physisorbed atoms to metal substrates: Xe on Au and Ti. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0305-4608/7/10/001] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Xu J, Gimenez-Conti IB, Cunningham JE, Collet AM, Luna MA, Lanfranchi HE, Spitz MR, Conti CJ. Alterations of p53, cyclin D1, Rb, and H-ras in human oral carcinomas related to tobacco use. Cancer 1998; 83:204-12. [PMID: 9669801 DOI: 10.1002/(sici)1097-0142(19980715)83:2<204::aid-cncr2>3.0.co;2-q] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Epidemiologic studies have indicated that environmental and personal habits, particularly tobacco use and alcohol abuse, are major etiologic factors in the induction and progression of head and neck squamous cell carcinomas (HNSCC). Molecular studies have focused on HNSCC related to smoking but not those associated with smokeless tobacco. METHODS The authors studied immunohistochemical evidence of alterations of p53, cyclin D1, and Rb in 34 human oral carcinomas related to tobacco use. They also examined p53 and H-ras using single strand conformation polymorphism (SSCP) and sequencing analysis. RESULTS Overexpression of cyclin D1 was found in 41% of cases, and accumulation of p53 was found in 59%. Only 9% of the samples did not show Rb staining. In SSCP and sequencing analysis, 17 cases showed mutations in the conserved region of the p53 gene. No mutations were detected in codons 12, 13, or 61 of the H-ras gene. CONCLUSIONS Overexpression of cyclin D1 and p53 mutations are common alterations in HNSCC. In contrast, the loss of Rb function seems to occur infrequently, and mutations in the H-ras gene apparently do not play a role in this cancer. HNSCC associated with smokeless tobacco contained the same alterations as those related to smoking.
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Affiliation(s)
- J Xu
- The University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, Smithville 78957, USA
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Krishnamoorthy AV, Woodward TK, Goossen KW, Walker JA, Hui SP, Tseng B, Cunningham JE, Jan WY, Kiamilev FE, Miller DA. Dual-function detector-modulator smart-pixel module. Appl Opt 1997; 36:4866-4870. [PMID: 18259290 DOI: 10.1364/ao.36.004866] [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: 05/25/2023]
Abstract
We describe a smart-pixel circuit that permits the use of a GaAs/AlGaAs multiple quantum well diode to be used both as a detector for data input and a modulator for data output. The module provides the ability to double the number of inputs or outputs to the array and is well suited to cascaded optoelectronic system architectures that require bidirectional communition.
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Carrier DJ, Cunningham JE, Taylor DC, Dunstan DI. Sucrose requirements and lipid utilization during germination of interior spruce (Picea glauca engelmannii complex) somatic embryos. Plant Cell Rep 1997; 16:550-554. [PMID: 30727577 DOI: 10.1007/bf01142322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/1996] [Revised: 12/06/1996] [Accepted: 12/31/1996] [Indexed: 06/09/2023]
Abstract
Both somatic and excised zygotic embryos of interior spruce (Picea glauca engelmannii complex) required exogenous sucrose in the medium for germination in vitro. Over a period of 29 days on sucrose-containing medium germinants with roots and epicotyls developed from both kinds of embryo, and their content of linolenic acid (9,12,15-18:3) increased about six- to eightfold. Without added sucrose, embryos showed retarded growth or were necrotic, and the content of linolenic acid was barely detectable in their fatty acid profiles. Through14C-sucrose uptake studies, it was determined that germinants consumed only 25% of the sucrose available in a 1% (wt/vol) sucrose-containing medium. Since no radiolabelled fatty acids were detected, it appears that externally supplied sucrose was not used in the synthesis of lipids. Although sucrose was present during plantlet development, 72% of the initial lipids were consumed. To some extent, the plantlets appeared to be obligate storage lipid utilizers.
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Affiliation(s)
- D J Carrier
- Plant Biotechnology Institute, National Research Council of Canada, 110 Gymnasium Place, S7N OW9, Saskatoon, Saskatchewan, Canada
| | - J E Cunningham
- Plant Biotechnology Institute, National Research Council of Canada, 110 Gymnasium Place, S7N OW9, Saskatoon, Saskatchewan, Canada
| | - D C Taylor
- Plant Biotechnology Institute, National Research Council of Canada, 110 Gymnasium Place, S7N OW9, Saskatoon, Saskatchewan, Canada
| | - D I Dunstan
- Plant Biotechnology Institute, National Research Council of Canada, 110 Gymnasium Place, S7N OW9, Saskatoon, Saskatchewan, Canada
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Collings BC, Stark JB, Tsuda S, Knox WH, Cunningham JE, Jan WY, Pathak R, Bergman K. Saturable Bragg reflector self-starting passive mode locking of a Cr(4+):YAG laser pumped with a diode-pumped Nd:YVO(4) laser. Opt Lett 1996; 21:1171-1173. [PMID: 19876289 DOI: 10.1364/ol.21.001171] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We demonstrate self-starting passive mode locking of a Cr (4+):YAG laser, using an intracavity nonlinear mirror as a saturable absorber. The pump source is a diode-pumped Nd:YVO(4) laser. Output pulses are centered at 1541 nm, with 26-nm spectral bandwidth and 110-fs pulse width. Output powers of 70 mW are obtained with 8 W of pump power. This mode locking technique is compared with Kerr-lens mode locking.
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Schäfer W, Kim DS, Shah J, Damen TC, Cunningham JE, Goossen KW, Pfeiffer LN, Köhler K. Femtosecond coherent fields induced by many-particle correlations in transient four-wave mixing. Phys Rev B Condens Matter 1996; 53:16429-16443. [PMID: 9983484 DOI: 10.1103/physrevb.53.16429] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Kyritsis AP, Zhang B, Zhang W, Xiao M, Takeshima H, Bondy ML, Cunningham JE, Levin VA, Bruner J. Mutations of the p16 gene in gliomas. Oncogene 1996; 12:63-7. [PMID: 8552400] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In the present study we investigated the frequency of p16 gene exon 2 mutations in 35 malignant gliomas, using either direct sequencing of the PCR products or cloning into the pCRII vector and sequencing of the cloned PCR products. No mutations were detected during direct sequencing of the PCR products. However, after sequencing of individual clones, we found multiple mutations in 5 tumors involving codons 73(GCC to ACC, Ala to Thr), 76 (GCC to GTC, Ala to Val), 85(GCT to ACT, Ala to Thr), 98(CAC to TAC, His to Tyr), 102 (GCG to GTG, Ala to Val), 106 (GTG to ATG, Val to Met), 107 (CGC to TGC, Arg to Cys), 127 (GCA to GTA, Ala to Val), 128 (CGG to TGG, Arg to Trp) and 136 (GGC to GAC, Gly to Asp). Mutations were found only in glioblastomas and were either C to T or G to A transitions. Each mutation was detected in a small percentage of tumor cells (1.3-22%) using individual colony sequencing and southern hybridization with mutant oligonucleotides, consistent with the heterogenous cell population of glioblastomas. The presence of p16 gene mutations only in glioblastomas suggests that they are late events in glioma development.
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Affiliation(s)
- A P Kyritsis
- Department of Neuro-Oncology, University of Texas MD Anderson Cancer Center, Houston, USA
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Fritze M, Perakis IE, Getter A, Knox W, Goossen KW, Cunningham JE, Jackson SA. Observation of a magnetic-field-induced transition in the behavior of extremely shallow quantum well excitons. Phys Rev Lett 1996; 76:106-109. [PMID: 10060445 DOI: 10.1103/physrevlett.76.106] [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: 05/23/2023]
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Kyritsis AP, Bondy ML, Hess KR, Cunningham JE, Zhu D, Amos CJ, Yung WK, Levin VA, Bruner JM. Prognostic significance of p53 immunoreactivity in patients with glioma. Clin Cancer Res 1995; 1:1617-22. [PMID: 9815964] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Abnormal p53 as revealed by immunostaining has been shown to be a predictor of poor outcome in a variety of malignant tumors. This study examines the relationship of p53 immunostaining and survival in 182 adult patients with gliomas. Tumor tissues obtained from patients with glioma within 4 months of initial diagnosis were investigated by immunohistochemical analysis for detection of p53 protein abnormalities using the monoclonal antibody PAb 1801. There were 122 patients with glioblastoma multiforme, 48 patients with anaplastic glioma, and 12 patients with low-grade glioma. Among these patients, 73 of those with glioblastoma multiforme, 35 with anaplastic glioma, and 6 with low-grade glioma had positive p53 immunoreactivity. Kaplan-Meier survival plots (log rank test) showed that the patients with anaplastic astrocytoma or low-grade glioma and p53-positive tumors had longer survival times compared to the patients with p53-negative tumors. No differences in survival were detected among the glioblastoma patients. Cox proportional hazards regression analysis, adjusted for age at diagnosis, showed that the p53 positivity was a significant predictor of longer survival (relative risk = 0.56; 95% confidence intervals = 0.35, 0.90; P = 0. 015) in anaplastic astrocytoma patients, but not in glioblastoma patients (relative risk = 1.03; 95% confidence intervals = 0.82, 1. 29; P = 0.80). These results suggest that anaplastic glioma patients with p53 protein alterations may have a better response to chemoradiation, possibly because the malignant cells cannot arrest in G1 to correct lethal damage induced by chemotherapy or radiotherapy.
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Affiliation(s)
- A P Kyritsis
- Departments of Neuro-Oncology, Biomathematics, Epidemiology, and Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
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Shahar D, Tsui DC, Cunningham JE. Observation of the nu =1 quantum Hall effect in a strongly localized two-dimensional system. Phys Rev B Condens Matter 1995; 52:14372-14375. [PMID: 9980762 DOI: 10.1103/physrevb.52.r14372] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Tomita A, Shah J, Cunningham JE, Goodnick SM, Lugli P, Chuang SL. Erratum: Femtosecond hole relaxation in n-type modulation-doped quantum wells. Phys Rev B Condens Matter 1995; 52:5445. [PMID: 9981736 DOI: 10.1103/physrevb.52.5445] [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: 04/12/2023]
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Tsuda S, Knox WH, de Souza EA, Jan WY, Cunningham JE. Low-loss intracavity AlAs/AlGaAs saturable Bragg reflector for femtosecond mode locking in solid-state lasers. Opt Lett 1995; 20:1406-1408. [PMID: 19862030 DOI: 10.1364/ol.20.001406] [Citation(s) in RCA: 11] [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: 05/28/2023]
Abstract
We introduce a new low-loss semiconductor structure for femtosecond intracavity mode locking in low-gain solidstate lasers. This monolithic device can be engineered to exhibit specif ic saturation characteristics desirable for mode locking solid-state lasers. Self-starting 90-fs pulses are obtained with Ti:sapphire and diode-pumped Cr:LiSAF lasers. We discuss mode-locking mechanisms in quantum-well passively mode-locked solid-state lasers.
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Shahar D, Tsui DC, Shayegan M, Bhatt RN, Cunningham JE. Universal conductivity at the quantum Hall liquid to insulator transition. Phys Rev Lett 1995; 74:4511-4514. [PMID: 10058525 DOI: 10.1103/physrevlett.74.4511] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Wang H, Shah J, Damen TC, Jan WY, Cunningham JE, Hong M, Mannaerts JP. Coherent oscillations in semiconductor microcavities. Phys Rev B Condens Matter 1995; 51:14713-14716. [PMID: 9978409 DOI: 10.1103/physrevb.51.14713] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Tracey DJ, Cunningham JE, Romm MA. Peripheral hyperalgesia in experimental neuropathy: mediation by alpha 2-adrenoreceptors on post-ganglionic sympathetic terminals. Pain 1995; 60:317-27. [PMID: 7596628 DOI: 10.1016/0304-3959(94)00141-z] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [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: 01/26/2023]
Abstract
Rats in which the sciatic nerve is partially transected develop hyperalgesia which is relieved by sympathectomy. We carried out experiments using this model of experimental peripheral neuropathy to examine the peripheral mechanisms underlying sympathetically maintained pain. Subcutaneous injection of noradrenaline (NA) into the affected paw exacerbated the hyperalgesia but had no effect in control animals. Injection of the non-specific alpha-adrenergic blocker phentolamine and the alpha 2-adrenergic blocker yohimbine significantly relieved the hyperalgesia, while injection of the alpha 1-adrenergic blocker prazosin had no effect. Peripheral injection of the alpha 2-adrenergic agonist clonidine had no significant effect, while injection of the alpha 1-adrenergic agonist phenylephrine produced slight exacerbation of mechanical hyperalgesia. Hyperalgesia was eliminated by peripheral injection of indomethacin into the affected paw. Following a chemical sympathectomy, hyperalgesia was eliminated and injection of NA into the hyperalgesic paw had no effect on pain thresholds. We concluded that NA exacerbates hyperalgesia in this experimental model by acting on alpha 2-adrenoreceptors which are located on post-ganglionic sympathetic terminals. Our results are consistent with the proposal (Levine et al. 1986) that activation of these adrenoreceptors brings about an increased release of prostaglandins which sensitises nociceptors.
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Affiliation(s)
- D J Tracey
- School of Anatomy, University of New South Wales, Sydney, Australia
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Hu BB, Knox WH, Cunningham JE, Nuss MC, Kuznetsov AV, Chuang SL. Identifying the distinct phases of carrier transport in semiconductors with 10 fs resolution. Phys Rev Lett 1995; 74:1689-1692. [PMID: 10059092 DOI: 10.1103/physrevlett.74.1689] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Kyritsis AP, Bondy ML, Xiao M, Berman EL, Cunningham JE, Lee PS, Levin VA, Saya H. Germline p53 gene mutations in subsets of glioma patients. J Natl Cancer Inst 1994; 86:344-9. [PMID: 8308926 DOI: 10.1093/jnci/86.5.344] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Heritable germline mutations of the p53 gene have been described in patients with Li-Fraumeni syndrome, occasionally in nonfamilial malignancies such as multifocal osteosarcoma, in a small subgroup of young patients with two or more primary malignancies, and in patients with sporadic breast carcinoma. We recently reported that multifocal gliomas are frequently associated with other primary malignancies, and we hypothesized that genetic alterations may account for this phenomenon. PURPOSE We examined the frequency of germline p53 gene mutations in patients with glioma and either multifocality of lesions, history of an additional primary (different) malignancy, or a family history of cancer. METHODS Lymphocytes from 51 glioma patients were analyzed for germline p53 gene mutations using RNA-polymerase chain reaction analysis, single-strand conformation polymorphism, and gene sequencing techniques. RESULTS Germline p53 gene mutations were detected in six of 19 patients with multifocal glioma, including two with family history of cancer, one with another primary malignancy, and two with all three risk factors; one of four patients with unifocal glioma, another primary malignancy, and a family history of cancer; and two of 15 patients with unifocal glioma and a family history of cancer but no second malignancies. No mutations were detected in the patient with unifocal glioma and another malignancy or in the 12 control patients with unifocal glioma and no second malignancies or family history of cancer. Patients having mutations were younger than other patients in the same group. CONCLUSIONS Germline p53 mutations are frequent in patients with multifocal glioma, glioma and another primary malignancy, and glioma associated with a family history of cancer, particularly if these factors are combined. IMPLICATIONS Relatives at high risk can be identified for genetic counseling, early cancer detection, and possible enrollment in chemoprevention trials.
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Affiliation(s)
- A P Kyritsis
- Department of Neuro-Oncology, University of Texas M.D. Anderson Cancer Center, Houston 77030
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Murray JL, Cunningham JE, Brewer H, Mujoo K, Zukiwski AA, Podoloff DA, Kasi LP, Bhadkamkar V, Fritsche HA, Benjamin RS. Phase I trial of murine monoclonal antibody 14G2a administered by prolonged intravenous infusion in patients with neuroectodermal tumors. J Clin Oncol 1994; 12:184-93. [PMID: 8270976 DOI: 10.1200/jco.1994.12.1.184] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
PURPOSE The purpose of this phase I trial was to determine the toxicity and maximum-tolerated dose (MTD) of murine monoclonal antibody (Mab) 14G2a (anti-GD2) in cancer patients. PATIENTS AND METHODS Following tracer doses of iodine-131-labeled 14G2a to determine tumor uptake, 18 patients with refractory melanoma, neuroblastoma, or osteosarcoma received unlabeled 14G2a at total concentrations of 50, 100, and 200 mg/m2 administered as daily 24-hour infusions for 5 days. RESULTS The overall sensitivity of external immunoscintigraphy was 64 of 74 known metastases (86%). Toxicity from prolonged infusion of 14G2a consisted of severe generalized pain, hyponatremia, fever, rash, paresthesias, weakness, and chronic refractory postural hypotension (two patients). Toxicity was less severe in pediatric patients. The MTD of Mab was 100 mg/m2. Sixteen of 18 patients developed human antimouse antibodies (HAMA) to 14G2a. Terminal-phase half-life (T1/2) of unlabeled Mab was 6.6 +/- 1.8 hours for patients receiving 50 mg/m2 and 39.5 +/- 13.3 hours at the 100-mg/m2 level. Tumor biopsies from six melanoma patients were positive for GD2 antigen, but only two of six had trace amounts of 14G2a present. Three mixed responses (two melanoma, one osteosarcoma) and two partial responses (PRs; neuroblastoma) were observed. CONCLUSION Mab 14G2a has modest antitumor activity at the expense of significant toxicity. Dose-limiting neurologic sequelae may significantly limit phase II studies other than in pediatric patients with neuroblastoma.
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Affiliation(s)
- J L Murray
- Department of Clinical Immunology and Biological Therapy, University of Texas M.D. Anderson Cancer Center, Houston 77030
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Tomita A, Shah J, Cunningham JE, Goodnick SM, Lugli P, Chuang SL. Femtosecond hole relaxation in n-type modulation-doped quantum wells. Phys Rev B Condens Matter 1993; 48:5708-5711. [PMID: 10009101 DOI: 10.1103/physrevb.48.5708] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Fox AM, Miller DA, Cunningham JE, Jan WY, Chao CY, Chuang SL. Suppression of the observation of Stark ladders in optical measurements on superlattices by excitonic effects. Phys Rev B Condens Matter 1992; 46:15365-15376. [PMID: 10003654 DOI: 10.1103/physrevb.46.15365] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Chang AM, Cunningham JE. Transport evidence for phase separation into spatial regions of different fractional quantum Hall fluids near the boundary of a two-dimensional electron gas. Phys Rev Lett 1992; 69:2114-2117. [PMID: 10046402 DOI: 10.1103/physrevlett.69.2114] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Feldmann J, Leo K, Shah J, Miller DA, Cunningham JE, Meier T, Schulze A, Thomas P, Schmitt-Rink S. Optical investigation of Bloch oscillations in a semiconductor superlattice. Phys Rev B Condens Matter 1992; 46:7252-7255. [PMID: 10002446 DOI: 10.1103/physrevb.46.7252] [Citation(s) in RCA: 281] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Su B, Goldman VJ, Cunningham JE. Single-electron tunneling in nanometer-scale double-barrier heterostructure devices. Phys Rev B Condens Matter 1992; 46:7644-7655. [PMID: 10002505 DOI: 10.1103/physrevb.46.7644] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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48
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Timp G, Behringer RE, Tennant DM, Cunningham JE, Prentiss M, Berggren KK. Using light as a lens for submicron, neutral-atom lithography. Phys Rev Lett 1992; 69:1636-1639. [PMID: 10046275 DOI: 10.1103/physrevlett.69.1636] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Goossen KW, Cunningham JE, Williams MD, Storz FG, Jan WY. Measured transition from two-dimensional to three-dimensional electroabsorption as quantum-well barriers are lowered. Phys Rev B Condens Matter 1992; 45:13773-13776. [PMID: 10001482 DOI: 10.1103/physrevb.45.13773] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Kim DS, Shah J, Cunningham JE, Damen TC, Schmitt-Rink S, Schäfer W. Carrier-carrier scattering in a degenerate electron system: Strong inhibition of scattering near the Fermi edge. Phys Rev Lett 1992; 68:2838-2841. [PMID: 10045505 DOI: 10.1103/physrevlett.68.2838] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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