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Sephton B, Vallés A, Nape I, Cox MA, Steinlechner F, Konrad T, Torres JP, Roux FS, Forbes A. Quantum transport of high-dimensional spatial information with a nonlinear detector. Nat Commun 2023; 14:8243. [PMID: 38092724 PMCID: PMC10719278 DOI: 10.1038/s41467-023-43949-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 11/24/2023] [Indexed: 12/17/2023] Open
Abstract
Information exchange between two distant parties, where information is shared without physically transporting it, is a crucial resource in future quantum networks. Doing so with high-dimensional states offers the promise of higher information capacity and improved resilience to noise, but progress to date has been limited. Here we demonstrate how a nonlinear parametric process allows for arbitrary high-dimensional state projections in the spatial degree of freedom, where a strong coherent field enhances the probability of the process. This allows us to experimentally realise quantum transport of high-dimensional spatial information facilitated by a quantum channel with a single entangled pair and a nonlinear spatial mode detector. Using sum frequency generation we upconvert one of the photons from an entangled pair resulting in high-dimensional spatial information transported to the other. We realise a d = 15 quantum channel for arbitrary photonic spatial modes which we demonstrate by faithfully transferring information encoded into orbital angular momentum, Hermite-Gaussian and arbitrary spatial mode superpositions, without requiring knowledge of the state to be sent. Our demonstration merges the nascent fields of nonlinear control of structured light with quantum processes, offering a new approach to harnessing high-dimensional quantum states, and may be extended to other degrees of freedom too.
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Affiliation(s)
- Bereneice Sephton
- School of Physics, University of the Witwatersrand, Wits, South Africa
| | - Adam Vallés
- School of Physics, University of the Witwatersrand, Wits, South Africa.
- Molecular Chirality Research Center, Chiba University, Chiba, Japan.
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain.
| | - Isaac Nape
- School of Physics, University of the Witwatersrand, Wits, South Africa
| | - Mitchell A Cox
- School of Electrical and Information Engineering, University of the Witwatersrand, Johannesburg, South Africa
| | - Fabian Steinlechner
- Fraunhofer Institute for Applied Optics and Precision Engineering, Jena, Germany
- Friedrich Schiller University Jena, Abbe Center of Photonics, Jena, Germany
| | - Thomas Konrad
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
- National Institute of Theoretical and Computational Sciences (NITheCS), KwaZulu-Natal, South Africa
| | - Juan P Torres
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
- Department of Signal Theory and Communications, Universitat Politecnica de Catalunya, Barcelona, Spain
| | - Filippus S Roux
- National Metrology Institute of South Africa, Pretoria, South Africa
| | - Andrew Forbes
- School of Physics, University of the Witwatersrand, Wits, South Africa.
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Thompson R, Corazzini K, Konrad T, Cary M, Silva S, McConnell E. BARRIERS AND FACILITATORS FOR FOREIGN EDUCATED NURSES TO PROVIDE QUALITY LONG-TERM CARE. Innov Aging 2022. [DOI: 10.1093/geroni/igac059.2861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Abstract
Unprecedented registered nursing shortages in long-term care (LTC) threaten the provision of person-centered care for older adults in the United States (US). LTC facilities recruit Foreign Educated Nurses (FENs) to address shortages, which raises concerns about care quality due to cultural, linguistic and communication differences among nurses; yet studies have not thoroughly explored FENs’ perspectives on these issues. The purpose of this study was to advance our understanding of FENs’ professional experiences as they began employment in LTC by exploring factors that inhibit or facilitate their provision of quality care. This qualitative descriptive study used purposive sampling to recruit FENs through professional organizations. Eligible FENs were ≥ 18 years old, worked ≥1 year in LTC, and represented racial and ethnic minority groups from Low and Middle Income Countries. In-depth narrative interviews, ranging from 45–60 minutes, were conducted. Applying content analysis, a priori and inductive coding generated themes. Participants (n=12) interviewed were all married females. Most were 50–59 years old (41.7%), Asian (75.0%), BSN-prepared (58.3%), and reported 31–50 years of nursing experience (50%). Positive facility characteristics, acculturation, effective workplace integration and positive support from colleagues, residents, and their families facilitated the provision of quality care. Conversely, negative facility characteristics, cultural barriers, discrimination and ineffective workplace integration were barriers to providing quality care. FENs highlighted culturally-sensitive strategies such as providing structured mentorship and preceptorship programs that supported them in providing person-centered care. FENs confirmed the need to address racial and anti-immigrant discrimination for achieving more equitable and inclusive workplaces.
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Affiliation(s)
- Roy Thompson
- University of Missouri , Colombia, Missouri , United States
| | | | - Thomas Konrad
- University of North Carolina at Chapel Hill , Chapel Hill, North Carolina , United States
| | - Michael Cary
- Duke University , Durham, North Carolina , United States
| | - Susan Silva
- Duke University , Durham, North Carolina , United States
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Thompson RA, Corazzini KN, Konrad T, Cary M, Silva SG, McConnell ES. Registered Nurse Migration to the United States and the Impact on Long-Term Care. J Am Med Dir Assoc 2021; 23:315-317. [PMID: 34979137 DOI: 10.1016/j.jamda.2021.12.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/16/2021] [Accepted: 12/16/2021] [Indexed: 10/19/2022]
Affiliation(s)
| | - Kirsten N Corazzini
- Duke University School of Nursing, Durham, NC, USA; University of Maryland School of Nursing, Baltimore, MD, USA
| | - Thomas Konrad
- Cecil G. Sheps Center for Health Services Research, University of North Carolina, Chapel Hill, NC, USA
| | - Michael Cary
- Duke University School of Nursing, Durham, NC, USA
| | | | - Eleanor S McConnell
- Duke University School of Nursing, Durham, NC, USA; Department of Veterans Affairs, GRECC, Durham, NC, USA
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Thompson R, Silva S, Corazzini K, Konrad T, Cary M, McConnell E. Human Capital and Employment Outcomes Among Foreign Educated and US Nurses Working in Long Term Care. Innov Aging 2021. [PMCID: PMC8755210 DOI: 10.1093/geroni/igab046.3194] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Employing Foreign Educated Nurses (FENs) helps address Registered Nurse (RN) shortages in long-term care (LTC) in the United States (US). However, examination of factors explaining differences in their employment outcomes relative to US Educated Nurses (USENs) is limited. This study uses 2018 National Sample Survey of Registered Nurses data to compare income, work hours, job satisfaction, and human capital, defined as personal characteristics (knowledge, work experience) and behaviors (job mobility), of FENS and USENs working full-time in LTC. A human capital score, consisting of highest nursing education, skill certifications, state licensures, years of experience, multi-state employment history, and multi-lingual status was constructed. Covariates included nurse demographics, direct care role, and ability to practice to full scope. Covariate-adjusted group differences in employment outcomes and human capital were compared using ANCOVA and logistic regression. Mediation analyses explored whether human capital explained FEN vs USEN differences. FENs earned higher hourly wages (p=0.0169), worked fewer hours annually (p=0.0163), and reported greater human capital (p<.0001) compared to USENs. FENs and USENs, however, had similar annual salaries (p=0.3101) and job satisfaction (p=0.1674). Human capital mediated FEN vs USEN effects on hourly wages but not annual work hours. FENs’ higher levels of human capital partially account for FEN vs USEN differences in hourly wages. Application of the human capital concept advanced our ability to examine differences in employment outcomes and highlight aspects of the value that FENs contribute to LTC settings.
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Affiliation(s)
- Roy Thompson
- Duke University, Durham, North Carolina, United States
| | - Susan Silva
- Duke University, Durham, North Carolina, United States
| | - Kirsten Corazzini
- University of Maryland School of Nursing, Baltimore, Maryland, United States
| | - Thomas Konrad
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Michael Cary
- Duke University, Durham, North Carolina, United States
| | - Eleanor McConnell
- Duke University School of Nursing, Durham, North Carolina, United States
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Thompson R, Konrad T, Xu H. Strengthening Strategies to Recruit Racial/Ethnic Minority Populations for Health Research Studies. Innov Aging 2021. [PMCID: PMC8968698 DOI: 10.1093/geroni/igab046.2394] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
With the current spotlight on systemic racism and the need to address health inequities, it is critical to develop culturally appropriate strategies for recruiting research study participants from racial/ethnic minority groups. Empirical studies have highlighted that people from racial/ethnic minority groups have poorer health outcomes compared to non-Hispanic Caucasians. However, racial/ethnic minority groups remain underrepresented in healthcare research. Several factors may contribute to the lower participation of racial/ethnic minority groups. Sequelae of atrocities in healthcare research on African American/Black people in the US during slavery and Jim Crow eras were widespread and persistent. Discrimination against people of Hispanic descent and increased anti-Asian discrimination have also been documented. Fear and mistrust of the health system and researchers have been identified as critical barriers to participation in clinical research for these populations. Further, health research teams rarely reflect the racial/ethnic diversity of the US population, hindering diversity in recruiting study participants. Inadequate ethnic/racial minority groups participation in study populations not only weakens external validity of empirical studies, but research interventions and policies being implemented may not be culturally appropriate to all populations. Therefore, systemic strategies to improve recruitment of racial/ethnic minority groups should: 1) increase preferential funding to incentivize research teams becoming more racially/ethnically diverse; 2) increase recruitment of racial/ethnically diverse healthcare researchers; 3) use community-based participatory research designs to build trust among racial/ethnic minority populations; 4) provide training on culturally appropriate research study recruitment strategies to the academic communities; 5) apply a prism of intersectionality for representation throughout the research cycle.
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Affiliation(s)
- Roy Thompson
- Duke University, Durham, North Carolina, United States
| | - Thomas Konrad
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Hanzhang Xu
- Duke University School of Medicine, Duke University, North Carolina, United States
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Yun J, Zerden LDS, Cuddeback G, Konrad T, Pathman DE. Overall Work and Practice Satisfaction of Licensed Clinical Social Workers in the National Health Service Corps Loan Repayment Program. Health Soc Work 2021; 46:9-21. [PMID: 33954777 DOI: 10.1093/hsw/hlaa033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/19/2019] [Accepted: 10/06/2019] [Indexed: 06/12/2023]
Abstract
Little is known about the job satisfaction of licensed clinical social workers (LCSWs) participating in the National Health Service Corps (NHSC) federal Loan Repayment Program (LRP). Employee satisfaction in organizations is important for organizational well-being and to decrease turnover. A satisfied NHSC LCSW workforce is also important given the array of services it provides, especially in rural and underserved areas. This study examined the work satisfaction of 386 LCSWs participating in the NHSC LRP in 21 states. Rural upbringing, being older than 40 years, and a higher salary were significantly associated with overall work and practice satisfaction. In addition, satisfaction with administration, staff and the practices' linkages to other health providers, the mission of the practice, and connection with patients were strongly associated with overall work and practice satisfaction. To our knowledge, this is the first study to examine the work and practice satisfaction of LCSWs participating in the NHSC LRP, and our findings have the potential to inform the NHSC's strategies in managing and retaining LCSWs.
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Lauterlein JJL, Hermann P, Konrad T, Wolf P, Nilsson P, Sánchez RG, Ferrannini E, Balkau B, Højlund K, Frost M. Serum sclerostin and glucose homeostasis: No association in healthy men. Cross-sectional and prospective data from the EGIR-RISC study. Bone 2021; 143:115681. [PMID: 33035729 DOI: 10.1016/j.bone.2020.115681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 10/04/2020] [Accepted: 10/05/2020] [Indexed: 01/24/2023]
Abstract
INTRODUCTION Sclerostin, an inhibitor of bone formation, has emerged as a potential negative regulator of glucose homeostasis. We aimed to investigate if serum sclerostin associates with insulin sensitivity, beta cell function, prediabetes or metabolic syndrome in healthy men. MATERIALS AND METHODS Serum sclerostin was measured in basal and insulin-stimulated samples from 526 men without diabetes from the RISC cohort study. An OGTT was performed at baseline and after 3 years. An IVGTT and a hyperinsulinaemic-euglycaemic clamp were performed at baseline. Insulin sensitivity was estimated by the oral glucose sensitivity index (OGIS) and the M-value relative to insulin levels. Beta cell function was assessed by the acute and total insulin secretion (ISRtot) and by beta cell glucose sensitivity. RESULTS Serum sclerostin levels correlated positively with age but were similar in individuals with (n = 69) and without (n = 457) prediabetes or the metabolic syndrome. Serum sclerostin was associated with measures of neither insulin sensitivity nor beta cell function at baseline in age-adjusted analyses including all participants. However, baseline serum sclerostin correlated inversely with OGIS at follow-up in men without prediabetes (B: -0.29 (-0.57, -0.01) p = 0.045), and inversely with beta cell glucose sensitivity in men with prediabetes (B: -13.3 (-26.3, -0.2) p = 0.046). Associations between serum sclerostin and 3-year changes in measures of glucose homeostasis were not observed. Acute hyperinsulinemia suppressed serum sclerostin (p = 0.02), and this reduction correlated with OGIS and ISRtot. CONCLUSIONS Overall, serum sclerostin was not associated with prediabetes, insulin sensitivity or insulin secretion in healthy men. The inverse relationship between serum sclerostin and insulin sensitivity at follow-up was weak and likely not of clinical relevance. The ability of insulin to reduce sclerostin, possibly promoting bone formation, needs to be clarified.
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Affiliation(s)
| | - Pernille Hermann
- Department of Endocrinology, Odense University Hospital, Odense, Denmark
| | - Thomas Konrad
- Institute for Metabolic Research, Goethe University, Frankfurt am Main, Germany
| | - Peter Wolf
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Austria
| | - Peter Nilsson
- Department of Clinical Sciences, Clinical Research Center, Lund University, Malmö, Sweden; Department of Internal Medicine, Skåne University Hospital, Malmö, Sweden
| | | | | | - Beverley Balkau
- Clinical Epidemiology, Université Paris-Saclay, UVSQ, Inserm, CESP, 94807 Villejuif, France
| | - Kurt Højlund
- Steno Diabetes Centre Odense, Odense University Hospital, Odense, Denmark
| | - Morten Frost
- Department of Endocrinology, Odense University Hospital, Odense, Denmark; Steno Diabetes Centre Odense, Odense University Hospital, Odense, Denmark
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Tricò D, Mengozzi A, Nesti L, Hatunic M, Gabriel Sanchez R, Konrad T, Lalić K, Lalić NM, Mari A, Natali A. Circulating palmitoleic acid is an independent determinant of insulin sensitivity, beta cell function and glucose tolerance in non-diabetic individuals: a longitudinal analysis. Diabetologia 2020; 63:206-218. [PMID: 31676981 DOI: 10.1007/s00125-019-05013-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 08/27/2019] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS Experimental studies suggest that the fatty acid palmitoleate may act as an adipocyte-derived lipid hormone (or 'lipokine') to regulate systemic metabolism. We investigated the relationship of circulating palmitoleate with insulin sensitivity, beta cell function and glucose tolerance in humans. METHODS Plasma NEFA concentration and composition were determined in non-diabetic individuals from the Relationship between Insulin Sensitivity and Cardiovascular disease (RISC) study cohort at baseline (n = 1234) and after a 3 year follow-up (n = 924). Glucose tolerance, insulin secretion and beta cell function were assessed during an OGTT. Whole-body insulin sensitivity was measured by a hyperinsulinaemic-euglycaemic clamp (M/I) and OGTT (oral glucose insulin sensitivity index [OGIS]). The liver insulin resistance index was calculated using clinical and biochemical data. Body composition including fat mass was determined by bioelectrical impedance. RESULTS Circulating palmitoleate was proportional to fat mass (r = 0.21, p < 0.0001) and total NEFA levels (r = 0.19, p < 0.0001). It correlated with whole-body insulin sensitivity (M/I: standardised regression coefficient [std. β] = 0.16, p < 0.0001), liver insulin resistance (std. β = -0.14, p < 0.0001), beta cell function (potentiation: std. β = 0.08, p = 0.045) and glucose tolerance (2 h glucose: std. β = -0.24, p < 0.0001) after adjustment for age, sex, BMI, adiposity and other NEFA. High palmitoleate concentrations prevented the decrease in insulin sensitivity associated with excess palmitate (p = 0.0001). In a longitudinal analysis, a positive independent relationship was observed between changes in palmitoleate and insulin sensitivity over time (std. β = 0.07, p = 0.04). CONCLUSIONS/INTERPRETATION We demonstrated that plasma palmitoleate is an independent determinant of insulin sensitivity, beta cell function and glucose tolerance in non-diabetic individuals. These results support the role of palmitoleate as a beneficial lipokine released by adipose tissue to prevent the negative effects of adiposity and excess NEFA on systemic glucose metabolism.
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Affiliation(s)
- Domenico Tricò
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy.
- Institute of Life Sciences, Sant'Anna School of Advanced Studies, Pisa, Italy.
| | - Alessandro Mengozzi
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy
| | - Lorenzo Nesti
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy
| | - Mensud Hatunic
- Department of Endocrinology, Mater Misericordiae University Hospital, University College Dublin School of Medicine, Dublin, Ireland
| | | | - Thomas Konrad
- Institute for Metabolic Research, Goethe University, Frankfurt am Main, Germany
| | - Katarina Lalić
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Nebojša M Lalić
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Andrea Mari
- Institute of Neuroscience, National Research Council, Padua, Italy
| | - Andrea Natali
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy
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Sephton B, Dudley A, Ruffato G, Romanato F, Marrucci L, Padgett M, Goyal S, Roux F, Konrad T, Forbes A. A versatile quantum walk resonator with bright classical light. PLoS One 2019; 14:e0214891. [PMID: 30964901 PMCID: PMC6456201 DOI: 10.1371/journal.pone.0214891] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/21/2019] [Indexed: 11/18/2022] Open
Abstract
In a Quantum Walk (QW) the "walker" follows all possible paths at once through the principle of quantum superposition, differentiating itself from classical random walks where one random path is taken at a time. This facilitates the searching of problem solution spaces faster than with classical random walks, and holds promise for advances in dynamical quantum simulation, biological process modelling and quantum computation. Here we employ a versatile and scalable resonator configuration to realise quantum walks with bright classical light. We experimentally demonstrate the versatility of our approach by implementing a variety of QWs, all with the same experimental platform, while the use of a resonator allows for an arbitrary number of steps without scaling the number of optics. This paves the way for future QW implementations with spatial modes of light in free-space that are both versatile and scalable.
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Affiliation(s)
- Bereneice Sephton
- School of Physics, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa
- CSIR National Laser Centre, PO Box 395, Pretoria, South Africa
| | - Angela Dudley
- School of Physics, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa
- CSIR National Laser Centre, PO Box 395, Pretoria, South Africa
| | - Gianluca Ruffato
- Department of Physics and Astronomy G. Galilei, University of Padova, Padova, Italy
| | - Filippo Romanato
- Department of Physics and Astronomy G. Galilei, University of Padova, Padova, Italy
- CNR-INFM TASC IOM National Laboratory, Trieste, Italy
| | - Lorenzo Marrucci
- Dipartimento di Fisica, University di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Napoli, Italy
| | - Miles Padgett
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - Sandeep Goyal
- Indian Institute of Science Education and Research, Mohali, Punjab, India
| | - Filippus Roux
- School of Physics, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa
- National Metrology Institute of South Africa, Pretoria, South Africa
| | - Thomas Konrad
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Andrew Forbes
- School of Physics, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa
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Sephton B, Vallés A, Steinlechner F, Konrad T, Torres JP, Roux FS, Forbes A. Spatial mode detection by frequency upconversion. Opt Lett 2019; 44:586-589. [PMID: 30702685 DOI: 10.1364/ol.44.000586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 12/25/2018] [Indexed: 05/28/2023]
Abstract
The efficient creation and detection of spatial modes of light has become topical of late, driven by the need to increase photon bit-rates in classical and quantum communications. Such mode creation/detection is traditionally achieved with tools based on linear optics. Here we put forward a new spatial mode detection technique based on the nonlinear optical process of sum-frequency generation. We outline the concept theoretically and demonstrate it experimentally with intense laser beams carrying orbital angular momentum and Hermite-Gaussian modes. Finally, we show that the method can be used to transfer an image from the infrared band to the visible, which implies the efficient conversion of many spatial modes.
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Marx A, Mollnau H, Sonnenschein S, Wenzel P, Muenzel T, Hoffmann B, Spittler R, Rostock T, Konrad T. P1028Acute myocarditis with suppressed cardiac function is associated with a high risk of sudden cardiac death in the early phase that can be prevented by the wearable cardioverter defibrillator. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy564.p1028] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- A Marx
- University Medical Center of Mainz, Clinic for Cardiology 2, Department of Electrophysiology, Mainz, Germany
| | - H Mollnau
- University Medical Center of Mainz, Clinic for Cardiology 2, Department of Electrophysiology, Mainz, Germany
| | - S Sonnenschein
- University Medical Center of Mainz, Clinic for Cardiology 2, Department of Electrophysiology, Mainz, Germany
| | - P Wenzel
- University Medical Center of Mainz, Clinic for Cardiology 1, Mainz, Germany
| | - T Muenzel
- University Medical Center of Mainz, Clinic for Cardiology 1, Mainz, Germany
| | - B Hoffmann
- University Medical Center of Mainz, Clinic for Cardiology 2, Department of Electrophysiology, Mainz, Germany
| | - R Spittler
- University Medical Center of Mainz, Clinic for Cardiology 2, Department of Electrophysiology, Mainz, Germany
| | - T Rostock
- University Medical Center of Mainz, Clinic for Cardiology 2, Department of Electrophysiology, Mainz, Germany
| | - T Konrad
- University Medical Center of Mainz, Clinic for Cardiology 2, Department of Electrophysiology, Mainz, Germany
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Hulman A, Witte DR, Vistisen D, Balkau B, Dekker JM, Herder C, Hatunic M, Konrad T, Færch K, Manco M. Pathophysiological Characteristics Underlying Different Glucose Response Curves: A Latent Class Trajectory Analysis From the Prospective EGIR-RISC Study. Diabetes Care 2018; 41:1740-1748. [PMID: 29853473 DOI: 10.2337/dc18-0279] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/02/2018] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Glucose measurements during an oral glucose tolerance test (OGTT) are useful in predicting diabetes and its complications. However, knowledge of the pathophysiology underlying differences in glucose curve shapes is sparse. We examined the pathophysiological characteristics that create different glucose curve patterns and studied their stability and reproducibility over 3 years of follow-up. RESEARCH DESIGN AND METHODS We analyzed data from participants without diabetes from the observational cohort from the European Group for the Study of Insulin Resistance: Relationship between Insulin Sensitivity and Cardiovascular Disease study; participants had a five-time point OGTT at baseline (n = 1,443) and after 3 years (n = 1,045). Measures of insulin sensitivity and secretion were assessed at baseline with a euglycemic-hyperinsulinemic clamp and intravenous glucose tolerance test. Heterogeneous glucose response patterns during the OGTT were identified using latent class trajectory analysis at baseline and at follow-up. Transitions between classes were analyzed with multinomial logistic regression models. RESULTS We identified four different glucose response patterns, which differed with regard to insulin sensitivity and acute insulin response, obesity, and plasma levels of lipids and inflammatory markers. Some of these associations were confirmed prospectively. Time to glucose peak was driven mainly by insulin sensitivity, whereas glucose peak size was related to both insulin sensitivity and secretion. The glucose patterns identified at follow-up were similar to those at baseline, suggesting that the latent class method is robust. We integrated our classification model into an easy-to-use online application that facilitates the assessment of glucose curve patterns for other studies. CONCLUSIONS The latent class analysis approach is a pathophysiologically insightful way to classify individuals without diabetes based on their response to glucose during an OGTT.
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Affiliation(s)
- Adam Hulman
- Department of Public Health, Aarhus University, Aarhus, Denmark .,Danish Diabetes Academy, Odense, Denmark
| | - Daniel R Witte
- Department of Public Health, Aarhus University, Aarhus, Denmark.,Danish Diabetes Academy, Odense, Denmark
| | | | - Beverley Balkau
- Centre for Research in Epidemiology and Population Health, Faculty of Medicine, University Paris-South, Paris, France.,Faculty of Medicine, University of Versailles-St. Quentin, Versailles, France.,INSERM U1018, University Paris-Saclay, Villejuif, France
| | - Jacqueline M Dekker
- Department of Epidemiology and Biostatistics, Amsterdam Public Health Research Institute, VU University Medical Center, Amsterdam, the Netherlands
| | - Christian Herder
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Mensud Hatunic
- Department of Endocrinology, Mater Misericordiae University Hospital, University College Dublin School of Medicine, Dublin, Ireland
| | - Thomas Konrad
- Institute for Metabolic Research, Goethe University, Frankfurt am Main, Germany
| | | | - Melania Manco
- Research Unit for Multi-factorial Diseases, Obesity and Diabetes, Istituti di Ricovero e Cura a Carattere Scientifico, Bambino Gesù Children's Hospital, Rome, Italy
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Frost M, Balkau B, Hatunic M, Konrad T, Mingrone G, Højlund K. The relationship between bone turnover and insulin sensitivity and secretion: Cross-sectional and prospective data from the RISC cohort study. Bone 2018; 108:98-105. [PMID: 29305997 DOI: 10.1016/j.bone.2017.12.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/18/2017] [Accepted: 12/29/2017] [Indexed: 01/27/2023]
Abstract
Bone metabolism appears to influence insulin secretion and sensitivity, and insulin promotes bone formation in animals, but similar evidence in humans is limited. The objectives of this study are to explore if bone turnover markers were associated with insulin secretion and sensitivity and to determine if bone turnover markers predict changes in insulin secretion and sensitivity. The study population encompassed 576 non-diabetic adult men with normal glucose tolerance (NGT; n=503) or impaired glucose regulation (IGR; n=73). Baseline markers of bone resorption (CTX) and formation (P1NP) were determined in the fasting state and after a 2-h hyperinsulinaemic, euglycaemic clamp. An intravenous glucose tolerance test (IVGTT) and a 2-h oral glucose tolerance test (OGTT) were performed at baseline, and the OGTT was repeated after 3years. There were no differences in bone turnover marker levels between NGT and IGR. CTX and P1NP levels decreased by 8.0% (p<0.001) and 1.9% (p<0.01) between baseline and steady-state during the clamp. Fasting plasma glucose was inversely associated with CTX and P1NP both before and after adjustment for recruitment centre, age, BMI, smoking and physical activity. However, baseline bone turnover markers were neither associated with insulin sensitivity (assessed using hyperinsulinaemic euglycaemic clamp and OGTT) nor with insulin secretion capacity (based on IVGTT and OGTT) at baseline or at follow-up. Although inverse associations between fasting glucose and markers of bone turnover were identified, this study cannot support an association between insulin secretion and sensitivity in healthy, non-diabetic men.
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Affiliation(s)
- Morten Frost
- Endocrine Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
| | - Beverley Balkau
- CESP, Faculty of Medicine - University Paris-South, Faculty of Medicine - University Versailles-St Quentin, INSERM U1018, University Paris-Saclay, Villejuif, France
| | - Mensud Hatunic
- Endocrinology Department, Mater Misericordiae University Hospital, Dublin, Ireland
| | - Thomas Konrad
- Clinic of Pediatrics I, Johann Wolfgang Goethe Universität am Main, Frankfurt, Germany
| | - Geltrude Mingrone
- Department of Internal Medicine, Catholic University of the Sacred Heart, Rome, Italy; Diabetes and Nutritional Sciences, King's College London, London, UK
| | - Kurt Højlund
- Endocrine Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark; Section of Molecular Diabetes & Metabolism, Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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Zhang Y, Agnew M, Roger T, Roux FS, Konrad T, Faccio D, Leach J, Forbes A. Simultaneous entanglement swapping of multiple orbital angular momentum states of light. Nat Commun 2017; 8:632. [PMID: 28935969 PMCID: PMC5608840 DOI: 10.1038/s41467-017-00706-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 07/21/2017] [Indexed: 12/03/2022] Open
Abstract
High-bit-rate long-distance quantum communication is a proposed technology for future communication networks and relies on high-dimensional quantum entanglement as a core resource. While it is known that spatial modes of light provide an avenue for high-dimensional entanglement, the ability to transport such quantum states robustly over long distances remains challenging. To overcome this, entanglement swapping may be used to generate remote quantum correlations between particles that have not interacted; this is the core ingredient of a quantum repeater, akin to repeaters in optical fibre networks. Here we demonstrate entanglement swapping of multiple orbital angular momentum states of light. Our approach does not distinguish between different anti-symmetric states, and thus entanglement swapping occurs for several thousand pairs of spatial light modes simultaneously. This work represents the first step towards a quantum network for high-dimensional entangled states and provides a test bed for fundamental tests of quantum science. Entanglement swapping in high dimensions requires large numbers of entangled photons and consequently suffers from low photon flux. Here the authors demonstrate entanglement swapping of multiple spatial modes of light simultaneously, without the need for increasing the photon numbers with dimension.
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Affiliation(s)
- Yingwen Zhang
- CSIR National Laser Centre, PO Box 395, Pretoria, 0001, South Africa.,Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, K1N 6N5, Canada
| | - Megan Agnew
- IPaQS, SUPA, Heriot-Watt, Edinburgh, EH14 4AS, UK
| | - Thomas Roger
- IPaQS, SUPA, Heriot-Watt, Edinburgh, EH14 4AS, UK
| | - Filippus S Roux
- CSIR National Laser Centre, PO Box 395, Pretoria, 0001, South Africa.,School of Physics, University of Witwatersrand, Johannesburg, 2000, South Africa.,National Metrology Institute of South Africa, Meiring Naude Road, Pretoria, South Africa
| | - Thomas Konrad
- School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban, 4000, South Africa.,National Institute of Theoretical Physics, University of KwaZulu-Natal, Private Bag X54001, Durban, 4000, South Africa
| | | | | | - Andrew Forbes
- CSIR National Laser Centre, PO Box 395, Pretoria, 0001, South Africa.,School of Physics, University of Witwatersrand, Johannesburg, 2000, South Africa
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Rutters F, Besson H, Walker M, Mari A, Konrad T, Nilsson PM, Balkau B, Dekker JM. The Association Between Sleep Duration, Insulin Sensitivity, and β-Cell Function: The EGIR-RISC Study. J Clin Endocrinol Metab 2016; 101:3272-80. [PMID: 27355399 DOI: 10.1210/jc.2016-1045] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT In the past decade, over 3 dozen studies reported a relationship between self-reported short sleep and disturbed glucose metabolism. A study with insulin sensitivity assessed according to the gold standard hyperinsulinemic-euglycemic clamp is, however, still missing. OBJECTIVE To evaluate the cross-sectional association of sleep duration with insulin sensitivity and β-cell function in the European group for the study of insulin resistance (EGIR-RISC) study cohort. DESIGN, SETTING, PARTICIPANTS, AND MEASURES We used data from the baseline measurements of the European, multicentre EGIR-RISC study that included 1319 clinically healthy participants. Sleep and physical activity were measured using a single-axis accelerometer. Insulin sensitivity and β-cell function were estimated by hyperinsulinemic-euglycemic clamp and from the oral glucose insulin sensitivity index model, using an oral glucose tolerance test. Associations of sleep duration with insulin sensitivity and β-cell function were analyzed by multiple linear regression, stratified by sex. RESULTS In our current analysis, we included 788 participants (57% women, age 44 ± 8 y), who had an average sleep duration of 7.3 ± 1.5 hours. In men, we observed an inverted U-shaped association between sleep duration categorized per hour and M/I (in μmol/min per kgFFM/nM per hour) (β-estimate [95% confidence intervals] 41 [2, 80]; P = .04 and β(2)-estimate -3 [-6, -0.2], P = .04) as well as a trend for the oral glucose insulin sensitivity index (in mL/min per kgFFM) (β-estimate [95% confidence intervals] 0.8 [-0.4, 2]; P = .17). In women, we observed a U-shaped association between sleep duration and β-cell function (in pmol/min per m(2)/mM per hour) (β-estimate -45 [-86, -3]; P = .04 and β(2)-estimate 3 [0.2, 6]; P = .04). CONCLUSIONS Sleep duration is associated with insulin sensitivity and β-cell function in a sex-specific manner in clinically healthy people.
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Affiliation(s)
- Femke Rutters
- Department of Epidemiology and Biostatistics (F.R., J.M.D.), Vrije Universiteit Medical Centre, 1081 BT Amsterdam, The Netherlands; EMGO+ Institute for Care Research (F.R., J.M.D.), Vrije Universiteit Medical Centre, Amsterdam, The Netherlands; PHARMO Institute for Drug Outcome Research (H.B.), Utrecht, The Netherlands; Institute of Cellular Medicine (M.W.), Medical School Newcastle University, Newcastle, United Kingdom; Institute of Neuroscience (A.M.), National Research Council, Padova, Italy; Institute for Metabolic Research (T.K.), Frankfurt, Germany; Department of Clinical Sciences (P.M.N.), Lund University and University Hospital Malmo, Lund, Sweden; and Inserm U1081CESP (B.B.), Centre for Research in Epidemiology and Population Health, Renal and Cardiovascular Epidemiology, Villejuif, France
| | - Herve Besson
- Department of Epidemiology and Biostatistics (F.R., J.M.D.), Vrije Universiteit Medical Centre, 1081 BT Amsterdam, The Netherlands; EMGO+ Institute for Care Research (F.R., J.M.D.), Vrije Universiteit Medical Centre, Amsterdam, The Netherlands; PHARMO Institute for Drug Outcome Research (H.B.), Utrecht, The Netherlands; Institute of Cellular Medicine (M.W.), Medical School Newcastle University, Newcastle, United Kingdom; Institute of Neuroscience (A.M.), National Research Council, Padova, Italy; Institute for Metabolic Research (T.K.), Frankfurt, Germany; Department of Clinical Sciences (P.M.N.), Lund University and University Hospital Malmo, Lund, Sweden; and Inserm U1081CESP (B.B.), Centre for Research in Epidemiology and Population Health, Renal and Cardiovascular Epidemiology, Villejuif, France
| | - Mark Walker
- Department of Epidemiology and Biostatistics (F.R., J.M.D.), Vrije Universiteit Medical Centre, 1081 BT Amsterdam, The Netherlands; EMGO+ Institute for Care Research (F.R., J.M.D.), Vrije Universiteit Medical Centre, Amsterdam, The Netherlands; PHARMO Institute for Drug Outcome Research (H.B.), Utrecht, The Netherlands; Institute of Cellular Medicine (M.W.), Medical School Newcastle University, Newcastle, United Kingdom; Institute of Neuroscience (A.M.), National Research Council, Padova, Italy; Institute for Metabolic Research (T.K.), Frankfurt, Germany; Department of Clinical Sciences (P.M.N.), Lund University and University Hospital Malmo, Lund, Sweden; and Inserm U1081CESP (B.B.), Centre for Research in Epidemiology and Population Health, Renal and Cardiovascular Epidemiology, Villejuif, France
| | - Andrea Mari
- Department of Epidemiology and Biostatistics (F.R., J.M.D.), Vrije Universiteit Medical Centre, 1081 BT Amsterdam, The Netherlands; EMGO+ Institute for Care Research (F.R., J.M.D.), Vrije Universiteit Medical Centre, Amsterdam, The Netherlands; PHARMO Institute for Drug Outcome Research (H.B.), Utrecht, The Netherlands; Institute of Cellular Medicine (M.W.), Medical School Newcastle University, Newcastle, United Kingdom; Institute of Neuroscience (A.M.), National Research Council, Padova, Italy; Institute for Metabolic Research (T.K.), Frankfurt, Germany; Department of Clinical Sciences (P.M.N.), Lund University and University Hospital Malmo, Lund, Sweden; and Inserm U1081CESP (B.B.), Centre for Research in Epidemiology and Population Health, Renal and Cardiovascular Epidemiology, Villejuif, France
| | - Thomas Konrad
- Department of Epidemiology and Biostatistics (F.R., J.M.D.), Vrije Universiteit Medical Centre, 1081 BT Amsterdam, The Netherlands; EMGO+ Institute for Care Research (F.R., J.M.D.), Vrije Universiteit Medical Centre, Amsterdam, The Netherlands; PHARMO Institute for Drug Outcome Research (H.B.), Utrecht, The Netherlands; Institute of Cellular Medicine (M.W.), Medical School Newcastle University, Newcastle, United Kingdom; Institute of Neuroscience (A.M.), National Research Council, Padova, Italy; Institute for Metabolic Research (T.K.), Frankfurt, Germany; Department of Clinical Sciences (P.M.N.), Lund University and University Hospital Malmo, Lund, Sweden; and Inserm U1081CESP (B.B.), Centre for Research in Epidemiology and Population Health, Renal and Cardiovascular Epidemiology, Villejuif, France
| | - Peter M Nilsson
- Department of Epidemiology and Biostatistics (F.R., J.M.D.), Vrije Universiteit Medical Centre, 1081 BT Amsterdam, The Netherlands; EMGO+ Institute for Care Research (F.R., J.M.D.), Vrije Universiteit Medical Centre, Amsterdam, The Netherlands; PHARMO Institute for Drug Outcome Research (H.B.), Utrecht, The Netherlands; Institute of Cellular Medicine (M.W.), Medical School Newcastle University, Newcastle, United Kingdom; Institute of Neuroscience (A.M.), National Research Council, Padova, Italy; Institute for Metabolic Research (T.K.), Frankfurt, Germany; Department of Clinical Sciences (P.M.N.), Lund University and University Hospital Malmo, Lund, Sweden; and Inserm U1081CESP (B.B.), Centre for Research in Epidemiology and Population Health, Renal and Cardiovascular Epidemiology, Villejuif, France
| | - Beverley Balkau
- Department of Epidemiology and Biostatistics (F.R., J.M.D.), Vrije Universiteit Medical Centre, 1081 BT Amsterdam, The Netherlands; EMGO+ Institute for Care Research (F.R., J.M.D.), Vrije Universiteit Medical Centre, Amsterdam, The Netherlands; PHARMO Institute for Drug Outcome Research (H.B.), Utrecht, The Netherlands; Institute of Cellular Medicine (M.W.), Medical School Newcastle University, Newcastle, United Kingdom; Institute of Neuroscience (A.M.), National Research Council, Padova, Italy; Institute for Metabolic Research (T.K.), Frankfurt, Germany; Department of Clinical Sciences (P.M.N.), Lund University and University Hospital Malmo, Lund, Sweden; and Inserm U1081CESP (B.B.), Centre for Research in Epidemiology and Population Health, Renal and Cardiovascular Epidemiology, Villejuif, France
| | - Jacqueline M Dekker
- Department of Epidemiology and Biostatistics (F.R., J.M.D.), Vrije Universiteit Medical Centre, 1081 BT Amsterdam, The Netherlands; EMGO+ Institute for Care Research (F.R., J.M.D.), Vrije Universiteit Medical Centre, Amsterdam, The Netherlands; PHARMO Institute for Drug Outcome Research (H.B.), Utrecht, The Netherlands; Institute of Cellular Medicine (M.W.), Medical School Newcastle University, Newcastle, United Kingdom; Institute of Neuroscience (A.M.), National Research Council, Padova, Italy; Institute for Metabolic Research (T.K.), Frankfurt, Germany; Department of Clinical Sciences (P.M.N.), Lund University and University Hospital Malmo, Lund, Sweden; and Inserm U1081CESP (B.B.), Centre for Research in Epidemiology and Population Health, Renal and Cardiovascular Epidemiology, Villejuif, France
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Zhang Y, Roux FS, Konrad T, Agnew M, Leach J, Forbes A. Engineering two-photon high-dimensional states through quantum interference. Sci Adv 2016; 2:e1501165. [PMID: 26933685 PMCID: PMC4771439 DOI: 10.1126/sciadv.1501165] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 12/11/2015] [Indexed: 05/09/2023]
Abstract
Many protocols in quantum science, for example, linear optical quantum computing, require access to large-scale entangled quantum states. Such systems can be realized through many-particle qubits, but this approach often suffers from scalability problems. An alternative strategy is to consider a lesser number of particles that exist in high-dimensional states. The spatial modes of light are one such candidate that provides access to high-dimensional quantum states, and thus they increase the storage and processing potential of quantum information systems. We demonstrate the controlled engineering of two-photon high-dimensional states entangled in their orbital angular momentum through Hong-Ou-Mandel interference. We prepare a large range of high-dimensional entangled states and implement precise quantum state filtering. We characterize the full quantum state before and after the filter, and are thus able to determine that only the antisymmetric component of the initial state remains. This work paves the way for high-dimensional processing and communication of multiphoton quantum states, for example, in teleportation beyond qubits.
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Affiliation(s)
- Yingwen Zhang
- Council for Scientific and Industrial Research (CSIR) National Laser Centre, PO Box 395, Pretoria 0001, South Africa
| | - Filippus S. Roux
- Council for Scientific and Industrial Research (CSIR) National Laser Centre, PO Box 395, Pretoria 0001, South Africa
- School of Physics, University of Witwatersrand, Johannesburg 2000, South Africa
| | - Thomas Konrad
- School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
- National Institute for Theoretical Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Megan Agnew
- Institute of Photonics and Quantum Science (IPaQS), Scottish Universities Physics Alliance (SUPA), Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Jonathan Leach
- Institute of Photonics and Quantum Science (IPaQS), Scottish Universities Physics Alliance (SUPA), Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Andrew Forbes
- School of Physics, University of Witwatersrand, Johannesburg 2000, South Africa
- Corresponding author. E-mail:
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17
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Rooney G, Kelly B, Konrad T, Scully M, Bates J. The effect of balanced versus non-balanced fluid replacement on urinary biomarkers in patients undergoing colectomy: a prospective observational pilot study. Intensive Care Med Exp 2015. [PMCID: PMC4797788 DOI: 10.1186/2197-425x-3-s1-a237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
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Konrad T, Jeitschko W. The Thorium Transition Metal Borides Th2TB10 (T = Fe, Co, Ni) with a Structure Very Similar to that of CaB6. Zeitschrift für Naturforschung B 2014. [DOI: 10.1515/znb-1995-0812] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The title compounds have been prepared by arc-melting cold-pressed pellets of the elemental components. They crystallize with a new structure type, which was determined from singlecrystal X-ray diffractometer data of Th2NiB10: Pbam, a = 564.6(2) pm, b = 1120.4(3) pm, c = 417.3(1) pm, Z = 2, R = 0.020 for 748 structure factors and 25 variable parameters. The structures of Th2FeB10 (a = 562.7(1) pm, b = 1126.1(3) pm, c = 418.3(2) pm) and Th2CoB10 (a = 562.4(1) pm, b = 1122.8(2) pm, c = 418.5(1) pm) were refined from single-crystal data to residuals of 0.025 (921 F values) and 0.032 (911 F values). The lattice of these ternary borides may be derived from that of ThB6 (Th2B12) with the cubic CaB6 type structure by replacing two of the linking boron atoms of adjacent B6 octahedra by a transition metal atom.
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Affiliation(s)
- Thomas Konrad
- Anorganisch-Chemisches Institut, Universität Münster, Wilhelm-Klemm-Straße 8, D-48149 Münster, Germany
| | - Wolfgang Jeitschko
- Anorganisch-Chemisches Institut, Universität Münster, Wilhelm-Klemm-Straße 8, D-48149 Münster, Germany
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19
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Goyal SK, Boukama-Dzoussi PE, Ghosh S, Roux FS, Konrad T. Qudit-teleportation for photons with linear optics. Sci Rep 2014; 4:4543. [PMID: 24686274 PMCID: PMC3971412 DOI: 10.1038/srep04543] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 03/04/2014] [Indexed: 11/24/2022] Open
Abstract
Quantum Teleportation, the transfer of the state of one quantum system to another without direct interaction between both systems, is an important way to transmit information encoded in quantum states and to generate quantum correlations (entanglement) between remote quantum systems. So far, for photons, only superpositions of two distinguishable states (one “qubit”) could be teleported. Here we show how to teleport a “qudit”, i.e. a superposition of an arbitrary number d of distinguishable states present in the orbital angular momentum of a single photon using d beam splitters and d additional entangled photons. The same entanglement resource might also be employed to collectively teleport the state of d/2 photons at the cost of one additional entangled photon per qubit. This is superior to existing schemes for photonic qubits, which require an additional pair of entangled photons per qubit.
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Affiliation(s)
- Sandeep K Goyal
- 1] School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa [2] The Institute of Mathematical Sciences, CIT Campus Taramani, Chennai 600 113, India
| | - Patricia E Boukama-Dzoussi
- School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Sibasish Ghosh
- The Institute of Mathematical Sciences, CIT Campus Taramani, Chennai 600 113, India
| | - Filippus S Roux
- CSIR National Laser Centre, PO Box 395, Pretoria 0001, South Africa
| | - Thomas Konrad
- 1] School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa [2] National Institute of Theoretical Physics (NITheP), University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
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20
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Buhr GT, Buhr GT, Konrad T, Pinheiro S, Pruitt J, Poer C, Shock L, Yanamadala M, Bailey D, White HK, Devarayasamudram S, Day L, Aselage M, Egerton EO, Matters L, McConnell E, Heflin MT. An Interprofessional Education Collaborative (IPEC) Competency-Focused Workshop to Enhance Team Performance. J Am Med Dir Assoc 2014. [DOI: 10.1016/j.jamda.2013.12.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Teleportation plays an important role in the communication of quantum information between the nodes of a quantum network and is viewed as an essential ingredient for long-distance Quantum Cryptography. We describe a method to teleport the quantum information carried by a photon in a superposition of a number d of light modes (a “qudit”) by the help of d additional photons based on transcription. A qudit encoded into a single excitation of d light modes (in our case Laguerre-Gauss modes which carry orbital angular momentum) is transcribed to d single-rail photonic qubits, which are spatially separated. Each single-rail qubit consists of a superposition of vacuum and a single photon in each one of the modes. After successful teleportation of each of the d single-rail qubits by means of “quantum scissors” they are converted back into a qudit carried by a single photon which completes the teleportation scheme.
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Affiliation(s)
- Sandeep K Goyal
- School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Thomas Konrad
- 1] School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa [2] National Institute of Theoretical Physics (NITheP), University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
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Schulze WHW, Schimpf R, Papavassiliu T, Potyagaylo D, Tulumen E, Rudic B, Liebe V, Doesch C, Konrad T, Veltmann C, Borggrefe M, Dössel O. Electrode Arrangements for ECG Imaging under Practical Constraints of a Catheter Lab Setting. ACTA ACUST UNITED AC 2013; 58 Suppl 1:/j/bmte.2013.58.issue-s1-G/bmt-2013-4156/bmt-2013-4156.xml. [PMID: 24042804 DOI: 10.1515/bmt-2013-4156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Goyal SK, Roux FS, Forbes A, Konrad T. Implementing quantum walks using orbital angular momentum of classical light. Phys Rev Lett 2013; 110:263602. [PMID: 23848875 DOI: 10.1103/physrevlett.110.263602] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 01/30/2013] [Indexed: 06/02/2023]
Abstract
We present an implementation scheme for a quantum walk in the orbital angular momentum space of a laser beam. The scheme makes use of a ring interferometer, containing a quarter-wave plate and a q plate. This setup enables one to perform an arbitrary number of quantum walk steps. In addition, the classical nature of the implementation scheme makes it possible to observe the quantum walk evolution in real time. We use nonquantum entanglement of the laser beam's polarization with its orbital angular momentum to implement the quantum walk.
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Affiliation(s)
- Sandeep K Goyal
- School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa.
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Golay A, Brock E, Gabriel R, Konrad T, Lalic N, Laville M, Mingrone G, Petrie J, Phan TM, Pietiläinen KH, Anderwald CH. Taking small steps towards targets - perspectives for clinical practice in diabetes, cardiometabolic disorders and beyond. Int J Clin Pract 2013; 67:322-32. [PMID: 23521324 DOI: 10.1111/ijcp.12114] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 12/18/2012] [Indexed: 01/26/2023] Open
Abstract
Big changes are hard. When trying to achieve guideline targets in diabetes and cardiometabolic disorders, patients can lack commitment or suffer despondency. It is much easier to make small changes in lifestyle or treatment, which are less noticeable and easier to manage long-term. Obesity is central to the cardiometabolic disorders, and even small weight losses of 2-5% can improve the cardiometabolic risk profile and substantially reduce the risk of developing type 2 diabetes. Likewise, small increases in physical activity, such as 15-30 min of brisk walking per day, can cut the risk of heart disease by 10%. Lifestyle or treatment changes that lead to small improvements in metabolic parameters also impact patient outcome - for example, a 5 mmHg decrease in blood pressure can translate into significant reductions in the rates of myocardial infarction and cardiovascular mortality. Benefits of small changes can also be seen in health economic outcome models. Implementing change at an individual versus a population level has different implications for overall benefit and patient motivation. Even very small steps taken in trying to reach guideline targets should represent a positive achievement for patients. Patient engagement is essential - only when patients commit themselves to change can benefits be maintained, and physicians should recognise their influence. Small changes in individual parameters can result in significant beneficial effects; however, a major impact can occur when small changes are made together in multiple parameters. More research is required to elucidate the full impact of small changes on patient outcome.
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Affiliation(s)
- A Golay
- Division of Therapeutical Teaching for Chronic Diseases, University Hospital Geneva, Geneva, Switzerland.
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Kozàkovà M, Palombo C, Morizzo C, Nolan JJ, Konrad T, Dekker JM, Balkau B, Nilsson PM. Gender-specific differences in carotid intima-media thickness and its progression over three years: a multicenter European study. Nutr Metab Cardiovasc Dis 2013; 23:151-158. [PMID: 21906922 DOI: 10.1016/j.numecd.2011.04.006] [Citation(s) in RCA: 17] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 03/30/2011] [Accepted: 04/05/2011] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND AIMS This multicentre European study evaluated, in a young-to-middle-aged healthy population without carotid atherosclerosis, the gender-related differences in carotid intima-media thickness (IMT) and its short-term (3-year) progression, and whether these differences are related to different vascular ageing rate, cardiovascular risk profile or different susceptibility to family predisposition to cardiovascular diseases (CVD). METHODS AND RESULTS 366 men and 422 women (age between 30 and 60 years) underwent B-mode carotid ultrasound at baseline and after 3-year follow-up period. IMT in 3 carotid segments was higher in men than in women (p < 0.0001 for all segments). When evaluated according to age decade, differences between men and women disappeared in the 6th decade, as in this decade a 3-year IMT progression rate accelerated in women (p < 0.05 as compared to the 4th and 5th age decade). Age was a major determinant of baseline all-segment IMT in women; in men all-segment IMT was influenced by age and LDL-cholesterol. IMT progression did not correlate with established cardiovascular risk factors, their short-term changes or family predisposition to CVD. Yet, a 3-year IMT progression in common carotid artery (CCA) was higher in men (p = 0.01) and women (p < 0.01) in whom relative Framingham risk increased during the corresponding period. CONCLUSION This study provides reference values on IMT and its short-term progression in healthy young-to-middle-aged population, and demonstrates gender-related differences in the susceptibility of carotid wall to ageing and LDL-cholesterol. Increase in Framingham risk accelerated a short-term CCA IMT progression rate in both genders, whereas family predisposition to CVD did not influence carotid IMT.
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Affiliation(s)
- M Kozàkovà
- Department of Internal Medicine, University of Pisa, via Roma 67, 56126 Pisa, Italy.
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Winkler P, Konrad T, Jakse G, Flitsch R, Partl R, Kapp K. Correlations Between Changes in Morphology and Dose Distribution for Adaptive Radiation Therapy in the Head and Neck Region. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.2117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Konrad T, Lübben G, Franzen C. Pioglitazone lowers blood pressure in hypertensive patients with type 2 diabetes mellitus : an open, multicentre, observational study. Clin Drug Investig 2012; 25:337-40. [PMID: 17532671 DOI: 10.2165/00044011-200525050-00006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Thomas Konrad
- Institute for Metabolic Research, EU-RISC Study Center, Frankfurt, Germany
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Bobbioni-Harsch E, Pataky Z, Makoundou V, Laville M, Disse E, Anderwald C, Konrad T, Golay A. From metabolic normality to cardiometabolic risk factors in subjects with obesity. Obesity (Silver Spring) 2012; 20:2063-9. [PMID: 22421925 DOI: 10.1038/oby.2012.69] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The aim of the study was to evaluate the 3 years incidence of cardiometabolic risk factors, such as impaired fasting glucose, reduced high-density lipoprotein (HDL)-cholesterol, increased plasma triglycerides or blood pressure as well as impaired glucose tolerance in overweight or obese (ow/ob) and normal body weight (nbw) subjects metabolically normal at baseline. Subjects from the Relationship between Insulin Sensitivity and Cardiovascular Disease (RISC) study were analyzed. We analyzed 284 nbw and 152 ow/ob subjects who, at baseline, did not show any of the above-mentioned cardiometabolic risk factors. At 3 years, these parameters were re-evaluated. Intima-media thickness (IMT) of the common carotid artery (CCA) was echographically measured. At follow-up, the incidence of one or more cardiometabolic risk factors was 57.2% in ow/ob vs. 31.7% in nbw (P < 0.0001). After adjustment for age, sex, menopause status, lifestyle parameters, insulin sensitivity, and fasting insulinemia, BMI remained significantly linked to the development of one or more cardiometabolic risk factors (P = 0.02). An increased BMI at follow-up was significantly associated with the development of cardiometabolic alterations, in both nbw and ow/ob groups (P = 0.04). Ow/ob subjects who, at 3 years follow-up, remained metabolically normal, showed a less favourable cardiometabolic profile, when compared to nbw counterparts. In ow/ob metabolically normal males and females, intima-media of the common carotid at follow-up was thicker than in nbw (P = 0.03 for males, P = 0.04 for females). In conclusion, metabolically normal obese subjects show a higher incidence of cardiometabolic risk factors, in a short follow-up period. Weight gain is significantly associated with the development of these factors, in both nbw and ow/ob subjects.
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Affiliation(s)
- Elisabetta Bobbioni-Harsch
- Service of Therapeutic Education for Chronic Diseases, WHO Collaborating Centre, Geneva University Hospital, Geneva, Switzerland
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Veltmann C, Papavassiliu T, Konrad T, Doesch C, Kuschyk J, Streitner F, Haghi D, Michaely HJ, Schoenberg SO, Borggrefe M, Wolpert C, Schimpf R. Insights into the location of type I ECG in patients with Brugada syndrome: correlation of ECG and cardiovascular magnetic resonance imaging. Heart Rhythm 2011; 9:414-21. [PMID: 22119454 DOI: 10.1016/j.hrthm.2011.10.032] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 10/26/2011] [Indexed: 11/29/2022]
Abstract
BACKGROUND Brugada syndrome is characterized by ST-segment abnormalities in V1-V3. Electrocardiogram (ECG) leads placed in the 3rd and 2nd intercostal spaces (ICSs) increased the sensitivity for the detection of a type I ECG pattern. The anatomic explanation for this finding is pending. OBJECTIVE The purpose of the study was to correlate the location of the Brugada type I ECG with the anatomic location of the right ventricular outflow tract (RVOT). METHODS Twenty patients with positive ajmaline challenge and 10 patients with spontaneous Brugada type I ECG performed by using 12 right precordial leads underwent cardiovascular magnetic resonance imaging (CMRI). The craniocaudal and lateral extent of the RVOT and maximal RVOT area were determined. Type I ECG pattern and maximal ST-segment elevation were correlated to extent and maximal RVOT area, respectively. RESULTS In all patients, Brugada type I pattern was found in the 3rd ICS in sternal and left-parasternal positions. RVOT extent determined by using CMRI included the 3rd ICS in all patients. Maximal RVOT area was found in 3 patients in the 2nd ICS, in 5 patients in the 4th ICS, and in 22 patients in the 3rd ICS. CMRI predicted type I pattern with a sensitivity of 97.2%, specificity of 91.7%, positive predictive value of 88.6%, and negative predictive value of 98.0%. Maximal RVOT area coincided with maximal ST-segment elevation in 29 of 30 patients. CONCLUSION RVOT localization determined by using CMRI correlates highly with the type I Brugada pattern. Lead positioning according to RVOT location improves the diagnosis of Brugada syndrome.
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Affiliation(s)
- C Veltmann
- 1st Department of Medicine-Cardiology, University Medical Centre Mannheim, Mannheim, Germany.
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Winkler K, Jacob S, Müller-Schewe T, Hoffmann MM, Konrad T. Ezetimibe alone and in combination lowers the concentration of small, dense low-density lipoproteins in type 2 diabetes mellitus. Atherosclerosis 2011; 220:189-93. [PMID: 22115011 DOI: 10.1016/j.atherosclerosis.2011.10.043] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 10/27/2011] [Accepted: 10/30/2011] [Indexed: 10/15/2022]
Abstract
OBJECTIVE The effectiveness of the cholesterol absorption inhibitor ezetimibe on LDL subfractions and ultimately on the atherosclerotic risk profile remains controversial. We thus determined the concentration of atherogenic small, dense LDL (sdLDL) in patients with type 2 diabetes and an elevated cardiovascular risk profile. RESEARCH DESIGN AND METHODS Multicenter, randomized, open-label 6-week study investigating the effect of ezetimibe 10mg (E), simvastatin 20mg (S) and the combination of ezetimibe-/simvastatin 10/20mg (C) on the concentration of sdLDL separated from fresh plasma by gradient ultracentrifugation in patients with type 2 diabetes (NCT01384058). RESULTS Fifty-six patients were screened for sdLDL, 41 were randomized, and 40 patients (12 E, 14 S and 14 C) completed the study. Total and LDL cholesterol fell by 14% (p=0.004) and 15% (p=0.006) with E, 22% (p<0.001) and 32% (p<0.001) with S, and 32% (p<0.001) and 44% (p<0.001) with C, respectively. E reduced the concentration of sdLDL by 20% (p=0.043) whereas S and C reduced sdLDL by 24% (p=0.020) and 33% (p=0.003), respectively, and non-sdLDL by 28% (p=0.004) and 42% (p<0.001), respectively. However, the further drop in sdLDL by adding E to S was not significant. CONCLUSION Ezetimibe alone and in combination with simvastatin reduced the concentration of atherogenic sdLDL in patients with type 2 diabetes.
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Affiliation(s)
- Karl Winkler
- Department of Clinical Chemistry, University Medical Center Freiburg, Hugstetter Straße 55, D-79106 Freiburg, Germany.
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Konrad T, Bär F, Schneider F, Franke S, Böhles H, Vetter G, Balkau B. Factors influencing endothelial function in healthy pre- and post-menopausal women of the EU-RISC study. Diab Vasc Dis Res 2011; 8:229-36. [PMID: 21746771 DOI: 10.1177/1479164111416139] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND We studied the impact of lifestyle, body composition, different insulin sensitivity indices and the first insulin response in healthy pre- and post-menopausal women with a low cardiovascular risk profile (the EU-RISC study, 'Relationship between Insulin Sensitivity and Cardiovascular Disease' (n = 51, 47 ± 4 years, body mass index 23.6 ± 3.7 kg/m(2), waist girth 79.2 ± 10.3 cm) on endothelial function (flow mediated arterial dilatation (FMD)), an early marker for atherosclerosis. RESULTS Waist circumference (p = 0.06), tobacco consumption (p = 0.02) and leucocyte count (p = 0.09) were inversely related with FMD in both pre- and post-menopausal women. Neither insulin sensitivity nor first insulin response indices were correlated with FMD. In pre-menopausal women (n = 24), waist (p < 0.02), waist-to-hip ratio (p < 0.02), HDL cholesterol (p < 0.01) and smoking habits (p < 0.03) were significantly correlated with endothelial function. In postmenopausal women (n = 27) age (r = -0.17, p = 0.04) was related with FMD. CONCLUSION Smoking and waist circumference, a simple marker of visceral adiposity, were related with endothelial function in healthy pre- and post-menopausal women.
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Affiliation(s)
- Thomas Konrad
- Institute for Metabolic Research, University Frankfurt am Main, Germany.
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Rebelos E, Muscelli E, Natali A, Balkau B, Mingrone G, Piatti P, Konrad T, Mari A, Ferrannini E. Body weight, not insulin sensitivity or secretion, may predict spontaneous weight changes in nondiabetic and prediabetic subjects: the RISC study. Diabetes 2011; 60:1938-45. [PMID: 21617179 PMCID: PMC3121437 DOI: 10.2337/db11-0217] [Citation(s) in RCA: 19] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Previous studies have found that high insulin sensitivity predicts weight gain; this association has not been confirmed. Our aim was to systematically analyze metabolic predictors of spontaneous weight changes. RESEARCH DESIGN AND METHODS In 561 women and 467 men from the Relationship Between Insulin Sensitivity and Cardiovascular Disease (RISC) cohort (mean age 44 years, BMI range 19-44 kg/m(2), 9% impaired glucose tolerance) followed up for 3 years, we measured insulin sensitivity (by a euglycemic clamp) and β-cell function (by modeling of the C-peptide response to oral glucose and by acute insulin response to intravenous glucose). RESULTS Insulin sensitivity was similar in weight gainers (top 20% of the distribution of BMI changes), weight losers (bottom 20%), and weight stable subjects across quartiles of baseline BMI. By multiple logistic or linear regression analyses controlling for center, age, sex, and baseline BMI, neither insulin sensitivity nor any β-cell function parameter showed an independent association with weight gain; this was true in normal glucose tolerance, impaired glucose tolerance, and whether subjects progressed to dysglycemia or not. Baseline BMI was significantly higher in gainers (26.1 ± 4.1 kg/m(2)) and losers (26.6 ± 3.7 kg/m(2)) than in weight stable subjects (24.8 ± 3.8 kg/m(2), P<0.0001 for both gainers and losers). Baseline waist circumference (or equivalently, BMI or weight) was a positive, independent predictor of both weight gain and weight loss (odds ratio 1.48 [95% CI 1.12-1.97]) in men and (1.67 [1.28-2.12]) in women. In men only, better insulin sensitivity was an additional independent predictor of weight loss. CONCLUSIONS Neither insulin sensitivity nor insulin secretion predicts spontaneous weight gain. Individuals who have attained a higher weight are prone to either gaining or losing weight regardless of their glucose tolerance.
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Affiliation(s)
- Eleni Rebelos
- Department of Internal Medicine, University of Pisa, Italy
| | - Elza Muscelli
- Department of Internal Medicine, University of Pisa, Italy
| | - Andrea Natali
- Department of Internal Medicine, University of Pisa, Italy
| | | | | | - Piermarco Piatti
- Diabetology, Endocrinology, and Metabolic Disease Unit, Fondazione Centro San Raffaele del Monte Tabor, Milan, Italy
| | - Thomas Konrad
- Clinic of Pediatrics I, Johan Wolfgang Goethe Universitat am Main, Frankfurt, Germany
| | - Andrea Mari
- CNR Institute of Biomedical Engineering, Padua, Italy
| | - Ele Ferrannini
- Department of Internal Medicine, University of Pisa, Italy
- Corresponding author: Ele Ferrannini,
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Winkler K, Jacob S, Schewe T, Putz G, Hoffmann M, Konrad T. 85 EZITIMIBE ALONE AND IN COMBINATION LOWERS CONCENTRATIONS OF SMALL, DENSE LOW DENSITY LIPOPROTEINS IN TYPE 2 DIABETES MELLITUS. ATHEROSCLEROSIS SUPP 2011. [DOI: 10.1016/s1567-5688(11)70086-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Bonnet F, Ducluzeau PH, Gastaldelli A, Laville M, Anderwald CH, Konrad T, Mari A, Balkau B. Liver enzymes are associated with hepatic insulin resistance, insulin secretion, and glucagon concentration in healthy men and women. Diabetes 2011; 60:1660-7. [PMID: 21521874 PMCID: PMC3114399 DOI: 10.2337/db10-1806] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The pathophysiological mechanisms to explain the association between risk of type 2 diabetes and elevated concentrations of γ-glutamyltransferase (GGT) and alanineaminotransferase (ALT) remain poorly characterized. We explored the association of liver enzymes with peripheral and hepatic insulin resistance, insulin secretion, insulin clearance, and glucagon concentration. RESEARCH DESIGN AND METHODS We studied 1,309 nondiabetic individuals from the Relationship between Insulin Sensitivity and Cardiovascular disease (RISC) study; all had a euglycemic-hyperinsulinemic clamp and an oral glucose tolerance test (OGTT) with assessment of insulin secretion and hepatic insulin extraction. The hepatic insulin resistance index was calculated in 393 individuals. RESULTS In both men and women, plasma concentrations of GGT and ALT were inversely related with insulin sensitivity (M/I) (all P < 0.01). Likewise, the hepatic insulin resistance index was positively correlated with both GGT (r = 0.37, P < 0.0001, men; r = 0.36, P < 0.0001, women) and ALT (r = 0.25, P = 0.0005, men; r = 0.18, P = 0.01, women). These associations persisted in multivariable models. Increased GGT and ALT were significantly associated with higher insulin secretion rates and with both reduced endogenous clearance of insulin and hepatic insulin extraction during the OGTT (P = 0.0005 in men; P = 0.003 in women). Plasma fasting glucagon levels increased over ALT quartiles (men, quartile 4 vs. quartile 1 11.2 ± 5.1 vs. 9.3 ± 3.8 pmol/L, respectively, P = 0.0002; women, 9.0 ± 4.3 vs. 7.6 ± 3.1, P = 0.001). CONCLUSIONS In healthy individuals, increased GGT and ALT were biomarkers of both systemic and hepatic insulin resistance with concomitant increased insulin secretion and decreased hepatic insulin clearance. The novel finding of a positive correlation between ALT and fasting glucagon level concentrations warrants confirmation in type 2 diabetes.
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Affiliation(s)
- Fabrice Bonnet
- Service Endocrinologie-Diabétologie, Centre Hospitalo-Universitaire(CHU) Rennes, University Rennes 1, INSERM UMR 991, Rennes, France.
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Duerr C, De Martin A, Sachet M, Konrad T, Baumann S, Spittler A. Influence of an immunoglobulin-enriched (IgG, IgA, IgM) solution on activation and immunomodulatory functions of peripheral blood mononuclear cells in a LPS second-hit model. Crit Care 2011. [PMCID: PMC3066918 DOI: 10.1186/cc9664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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Dudley A, Nock M, Konrad T, Roux FS, Forbes A. Amplitude damping of Laguerre-Gaussian modes. Opt Express 2010; 18:22789-22795. [PMID: 21164617 DOI: 10.1364/oe.18.022789] [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: 05/30/2023]
Abstract
We present an amplitude damping channel for Laguerre-Gaussian modes. Our channel is tested experimentally for a Laguerre-Gaussian mode, having an azimuthal index l = 1, illustrating that it decays to a Gaussian mode in good agreement with the theoretical model for amplitude damping. Since we are able to characterize the action of such a channel on orbital angular momentum states, we propose using it to investigate the dynamics of entanglement.
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Affiliation(s)
- Angela Dudley
- CSIR National Laser Centre, PO Box 395, Pretoria 0001, South Africa
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Costet P, Hoffmann M, Cariou B, Delasalle BG, Konrad T, Winkler K. Plasma PCSK9 is increased by Fenofibrate and Atorvastatin in a non-additive fashion in diabetic patients. Atherosclerosis 2010; 212:246-51. [DOI: 10.1016/j.atherosclerosis.2010.05.027] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 04/26/2010] [Accepted: 05/18/2010] [Indexed: 10/19/2022]
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Manco M, Panunzi S, Macfarlane DP, Golay A, Melander O, Konrad T, Petrie JR, Mingrone G. One-hour plasma glucose identifies insulin resistance and beta-cell dysfunction in individuals with normal glucose tolerance: cross-sectional data from the Relationship between Insulin Sensitivity and Cardiovascular Risk (RISC) study. Diabetes Care 2010; 33:2090-7. [PMID: 20805281 PMCID: PMC2928370 DOI: 10.2337/dc09-2261] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Some individuals with normal glucose tolerance (NGT) exhibit a 1-h excursion of plasma glucose during oral glucose tolerance testing as high as that of individuals with impaired glucose tolerance (IGT). The aim of this study was to characterize their metabolic phenotype. RESEARCH DESIGN AND METHODS A total of 1,205 healthy volunteers (aged 29-61 years) underwent assessment of 1) oral glucose tolerance and 2) insulin sensitivity (standardized euglycemic-hyperinsulinemic clamp), as part of the Relationship between Insulin Sensitivity and Cardiovascular Risk (RISC) study. RESULTS One-hour plasma glucose correlated better than 2-h plasma glucose with total insulin secretion (r = 0.43), beta-cell glucose sensitivity (r = -0.46), and beta-cell rate sensitivity (r = -0.18). Receiver operating characteristic analysis identified 8.95 mmol/l as the best cutoff value for prediction of IGT from 1-h plasma glucose (sensitivity 77% and specificity 80%). Participants with NGT with 1-h plasma glucose >8.95 mmol/l had larger waist circumference, higher BMI, lower insulin sensitivity, higher fasting glucose, and higher insulin secretion than their counterparts with 1-h plasma glucose <or=8.95 mmol/l (P < 0.001 for all comparisons). Moreover, they exhibited lower beta-cell glucose sensitivity (P < 0.001), beta-cell rate sensitivity (P < 0.001), and potentiation factor (P = 0.026). When compared with conventionally defined IGT, they were not different in waist circumference and BMI, hepatic insulin extraction, beta-cell glucose sensitivity, beta-cell rate sensitivity, and potentiation factor but did have greater insulin sensitivity along with reduced basal (P = 0.001) and total insulin secretion (P = 0.002). CONCLUSIONS Higher values of 1-h plasma glucose may identify an intermediate condition between NGT and IGT characterized by greater insulin resistance, reduced beta-cell glucose sensitivity, and reduced beta-cell rate sensitivity.
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Affiliation(s)
- Melania Manco
- Bambino Gesù Hospital, Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy.
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Kozàkovà M, Palombo C, Morizzo C, Nolan JJ, Konrad T, Balkau B. Effect of sedentary behaviour and vigorous physical activity on segment-specific carotid wall thickness and its progression in a healthy population. Eur Heart J 2010; 31:1511-9. [PMID: 20400760 DOI: 10.1093/eurheartj/ehq092] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
AIMS This study investigated whether sedentary behaviour and different activity levels have an independent association with carotid intima-media thickness (IMT) and with the 3-year IMT progression in different carotid segments. METHODS AND RESULTS The study population included 614 healthy men and women (mean age = 44 +/- 8 years) without carotid atherosclerosis and without increased coronary heart disease risk, who underwent B-mode carotid ultrasound and objective physical activity assessment by accelerometer (mean monitoring time = 5.7 +/- 1.5 days). Time spent in sedentary (57.6 +/- 9.1%), light (41.0 +/- 9.2%), moderate and vigorous activities was determined. Sedentary behaviour was expressed as the ratio of time spent in sedentary and light activity (sedentary/light ratio) as these two activities occupied the majority of waking time. In 495 subjects, the carotid ultrasound was repeated 3 years after the baseline examination. After adjustment for age and the established risk factors that were independent determinants of carotid wall thickness in our population, sedentary/light ratio was independently associated only with the common carotid artery (CCA) IMT. The 3-year increase in CCA IMT was significantly lower in subjects with periods of vigorous activity (7 +/- 40 microm) when compared with those with light activity only or with periods of moderate activity (22 +/- 51 and 19 +/- 46 microm, respectively, P < 0.05). CONCLUSION The healthy, young-to-middle age population of this study spent more than half of their waking time in sedentary activities. The proportion of time spent in sedentary activities was directly associated with baseline CCA IMT, independently of age and established atherosclerotic risk factors. In the longitudinal analysis, period of vigorous activity influenced the 3-year IMT progression in CCA.
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Affiliation(s)
- Michaela Kozàkovà
- Department of Internal Medicine, University of Pisa, Via Roma, 67, Pisa 56122, Italy.
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Schöndorf T, Musholt PB, Mohr TA, Diessel S, Forst T, Konrad T, Backus J, Löbig M, Pfützner A. Die Berechnung der individuellen Insulin Sensitivität ist abhängig von der verwendeten Messmethodik. DIABETOL STOFFWECHS 2010. [DOI: 10.1055/s-0030-1253928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Konrad T, Franke S, Schneider F, Bär F, Vetter G, Winkler K. Nocturnal blood pressure but not insulin resistance influences endothelial function in treated hypertensive patients. J Hum Hypertens 2010; 25:18-24. [DOI: 10.1038/jhh.2010.23] [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: 11/09/2022]
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Forst T, Wilhelm B, Pfützner A, Fuchs W, Lehmann U, Schaper F, Weber M, Müller J, Konrad T, Hanefeld M. Investigation of the vascular and pleiotropic effects of atorvastatin and pioglitazone in a population at high cardiovascular risk. Diab Vasc Dis Res 2008; 5:298-303. [PMID: 18958840 DOI: 10.3132/dvdr.2008.043] [Citation(s) in RCA: 36] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We investigated the effect of atorvastatin monotherapy and combined treatment with atorvastatin and pioglitazone on intima-media thickness, vascular function and the cardiovascular risk profile. In all, 148 patients (76 male, 72 female; aged 61.4+/-6.5 years; body mass index [BMI] 29.2+/-4.1 kg/m2; mean +/- SD) with increased cardiovascular (CV) risk factors were randomised. Intima-media thickness (IMT), the augmentation index (Aix@75), the microvascular response to acetylcholine (LDF), lipid status, and plasma levels of intact proinsulin, adiponectin, interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9), sCD40L, P-selectin, tissue plasminogen activator (t-PA) and blood lipids were monitored over six months. Atorvastatin treatment, alone and in combination with pioglitazone, revealed a significant regression in IMT (0.923+/-0.013 to 0.874+/-0.012 mm and 0.921+/-0.015 to 0.882+/-0.015 mm; mean +/- SEM; p<0.05 respectively) and Aix@75 (27.3+/-1.2 to 25.9+/-1.4; and 25.6+/-1.4 to 24.8+/-1.7%; p<0.05). The endothelial response to acetylcholine as measured by laser Doppler fluximetry (LDF) improved during combined treatment (373+/-57 to 576+/-153 AU; p<0.05). Addition of pioglitazone to atorva-statin resulted in significant further effects on high-sensitivity C-reactive protein (hsCRP), t-PA, P-selectin, adiponectin, triglycerides and high-density lipoprotein (HDL) cholesterol (p<0.05 respectively). Atorvastatin significantly improved IMT and vascular elasticity. Co-administration of pioglitazone provided additional effects on endothelial function, lipid profile and laboratory markers of inflammation.
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Affiliation(s)
- Thomas Forst
- Medical Director, Institute for Clinical Research and Development, Mainz, Germany.
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Kozakova M, Palombo C, Paterni M, Anderwald CH, Konrad T, Colgan MP, Flyvbjerg A, Dekker J. Body composition and common carotid artery remodeling in a healthy population. J Clin Endocrinol Metab 2008; 93:3325-32. [PMID: 18593775 DOI: 10.1210/jc.2007-2484] [Citation(s) in RCA: 36] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT An independent association between obesity and preclinical carotid atherosclerosis has been demonstrated, however, the pathophysiological links were not clearly established. Body composition (BC) influences systemic hemodynamics and may participate in the remodeling of common carotid artery (CCA), independently of risk factors. OBJECTIVE This study evaluated the association between CCA structure and BC in a large population of healthy subjects. DESIGN This was a cross-sectional study. SETTINGS The study was conducted at 19 European centers. SUBJECTS The study included 627 healthy subjects (252 men, age 30-60 yr, body mass index 17-40 kg/m2). MAIN OUTCOME MEASURES CCA luminal diameter and intima-media thickness were measured on digitized ultrasound images. Acoustic properties of CCA wall were evaluated by digital densitometric analysis and described in terms of mean gray level. BC was assessed by electrical bioimpedance. Insulin sensitivity (euglycemic hyperinsulinemic clamp) and plasma adiponectin levels were measured. Associations between CCA structure, age, BC, and metabolic and atherosclerotic risk factors were analyzed by multivariate regression models. RESULTS Independent factors affecting CCA diameter were fat-free mass and waist girth (standardized r = 0.44 and 0.12; P < 0.01 and < 0.0001; R2 = 0.35); independent correlates of intima-media thickness were age, CCA diameter, systolic blood pressure, and low-density lipoprotein-cholesterol (standardized r = 0.39, 0.25, 0.10, and 0.14; P < 0.005-0.0001; R2 = 0.40). The mean gray level of carotid wall was independently associated with age and waist girth (standardized r = 0.23 and 0.12; P < 0.0001 and = 0.001; R2 = 0.30). CONCLUSIONS Findings of this cross-sectional study suggest that BC modulates CCA diameter, and may induce adaptive changes in carotid wall thickness, independently of metabolic and atherosclerotic factors. Central adiposity modifies the acoustic properties of carotid wall.
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Affiliation(s)
- Michaela Kozakova
- Department of Internal Medicine, University of Pisa, Via Roma 67, 56126 Pisa, Italy.
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Wilhelm B, Pfützner A, Fuchs W, Lehmann U, Scharper F, Weber M, Müller J, Konrad T, Hanefeld M, Forst T. Pioglitazon in Kombination mit Atorvastatin verbessert die endotheliale Funktion und reduziert das kardiovaskuläre Risikoprofil. DIABETOL STOFFWECHS 2008. [DOI: 10.1055/s-2008-1076242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Vossler S, Füllert S, Schneider F, Haak E, Haak T, Samigullin R, Tritschler H, Tooke JE, Konrad T. Pharmacodynamic effects of orally administered dexlipotam on endothelial function in type 2-diabetic patients. Int J Clin Pharmacol Ther 2007; 45:385-93. [PMID: 17725245 DOI: 10.5414/cpp45385] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE Diabetic endotheliopathy is the result of hyperglycemia and the production of oxygen-free radicals. In vitro and in vivo data have shown beneficial effects of dexlipotam (DEX), a tromethamine salt of R(+)-alpha-lipoic acid, on oxidative stress in hyperglycemic states, but no data are available on the effects of this agent on endothelial function. The purpose of this pilot study was to evaluate the impact of DEX on endothelial function in patients with type 2 diabetes (DM2) and to estimate the safety and tolerability of DEX. MATERIAL AND METHODS DEX 960 mg and DEX 1,920 mg were investigated in DM2 patients over a period of 4 weeks using a randomized, placebo- (PLA) controlled, double-blinded study with 3 parallel groups. The marker of arterial function after 4-week therapy with DEX was the maximum percentage change versus baseline in the flow-mediated dilation of the brachial artery (FMD) after reperfusion. RESULTS A total of 114 diabetic patients were randomized to the three study groups. DEX was safe and well tolerated. Dyspepsia appeared to be the most relevant side effect of DEX treatment. Systolic (p = 0.078) and diastolic blood pressure (p = 0.059) tended to be lower in patients treated with DEX at a dose of 1,920 mg. There were no significant differences in FMD between the placebo- and the DEX-treated groups. In patients with poorer glucose control (HbA1c > 6.5% Hb), FMD increased significantly after 4-week treatment with DEX: PLA -1.51 +/- 2.98%, DEX 960 mg +1.22 +/- 3.22, p = 0.027, DEX 1,920 mg +1.47 +/- 3.78, p= 0.012. The magnitude of the mean change compared to placebo was 2.73% (DEX 920) and 2.98% (DEX 1,920) in patients with HbAlc > 7.5% Hb (DEX 960, p = 0.007, DEX 1,920, p = 0.032). The effects of treatment were usually statistically significant in subgroups with more severe vascular stress (longer duration of disease, pretreatment history, higher LDL-C, higher blood pressure). CONCLUSION DEX therapy appears to reduce endothelial dysfunction in DM2, especially in men with long history of DM2 and having poor glucose control. These findings will be useful in patient selection in future prospective clinical trials with drugs to treat vascular stress.
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Affiliation(s)
- S Vossler
- Institute for Metabolic Research, Academic Institute of the Medical Faculty of Johann Wolfgang Goethe University Frankfurt/Main, Germany
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Kozakova M, Palombo C, Mhamdi L, Konrad T, Nilsson P, Staehr PB, Paterni M, Balkau B. Habitual physical activity and vascular aging in a young to middle-age population at low cardiovascular risk. Stroke 2007; 38:2549-55. [PMID: 17656659 DOI: 10.1161/strokeaha.107.484949] [Citation(s) in RCA: 39] [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: 12/16/2022]
Abstract
BACKGROUND AND PURPOSE Regular endurance exercise has been shown to reduce the age-related increase in arterial stiffness that is thought to contribute to cardiovascular risk. The aim of this study was to evaluate the influence of age and habitual physical activity on carotid artery wall thickness and stiffness in a population of young to middle-age subjects at low cardiovascular risk. METHODS The study population consisted of 432 healthy subjects (166 men; mean+/-SD age, 43+/-8 years; range, 30 to 60 years) free of carotid atherosclerosis and with low coronary heart disease risk, as determined by the Framingham prediction score sheet. All subjects underwent B-mode ultrasonography of the extracranial carotid arteries and physical activity assessment by actigraph, an accelerometer capable of monitoring the intensity and duration of body movements. The intima-media thickness of the common carotid artery was measured on ultrasound images, along with systodiastolic changes in luminal diameter, and indices of carotid stiffness were calculated. RESULTS Intima-media thickness and carotid stiffness increased with age in both men and women (r=0.24 to 0.52, P<0.001). The magnitude of objectively assessed daily physical activity was negatively related to indices of carotid stiffness (r from -0.20 to -0.25, P<0.001) but not to intima-media thickness. In multivariate regression analyses that included several cardiovascular risk factors such as obesity, blood pressure, plasma lipids, and smoking habits, age and physical activity were independently related to carotid stiffness. CONCLUSIONS This study provides cross-sectional evidence that habitual physical activity is inversely related to the age-dependent increase in carotid wall stiffness in a young to middle-age population at low risk.
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Stockmann M, Konrad T, Nolting S, Hünerbein D, Wernecke KD, Döbling H, Steinmüller T, Neuhaus P. Major influence of liver function itself but not of immunosuppression determines glucose tolerance after living-donor liver transplantation. Liver Transpl 2006; 12:535-43. [PMID: 16496277 DOI: 10.1002/lt.20633] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Controversial data exists concerning the impact of immunosuppressive therapy on the development of post-transplantation diabetes mellitus (PTDM). Therefore, we investigated glucose metabolism in healthy donors and in recipients of living-donor liver transplants (LD-LTX, n=18) without pre-existing diabetes mellitus before, on day 10, month 6, and month 12 after intervention. The computer-assisted analysis of glucose, insulin, and C-peptide profiles obtained from frequently sampled intravenous glucose tolerance tests allows to achieve an integrated view of factors controlling glucose tolerance, i.e., insulin sensitivity (SI), first and second phase insulin secretion (phi1 and phi2). SI of donors declined by day 10 after operation (SI 2.65 +/- 0.41 vs. 4.90 +/- 0.50 10(-4) minute(-1) microU ml(-1), P < 0.01) but returned to values as before after 6 months. Phi1 did not change. Phi(2), however, significantly increased by day 10 (8.57 +/- 0.82 10(9) minute(-1) to 13.77 +/- 1.53 10(9) minute(-1), P < 0.01) but was in the same range as before after 6 months. In parallel to donors SI of recipients progressively increased after LD-LTX. Phi1 did not alter in recipients. Phi2 continuously decreased and was not different from donors by month 12. The extent of liver injury assessed by liver enzyme concentrations and liver function represented by cholinesterase activity, albumin, and INR were closely related with changes of SI in donors and recipients during the first year after intervention. In conclusion, the extent of liver damage plays a predominant role in regulating glucose tolerance. No impact of immunosuppressive therapy on SI, phi1 and phi2 was detected.
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Affiliation(s)
- Martin Stockmann
- Department of General, Visceral, and Transplantation Surgery, University Hospital Charité--Campus Virchow Klinikum, Berlin, Germany.
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Forst T, Hohberg C, Fuellert SD, Lübben G, Konrad T, Löbig M, Weber MM, Sachara C, Gottschall V, Pfützner A. Pharmacological PPARgamma stimulation in contrast to beta cell stimulation results in an improvement in adiponectin and proinsulin intact levels and reduces intima media thickness in patients with type 2 diabetes. Horm Metab Res 2005; 37:521-7. [PMID: 16138267 DOI: 10.1055/s-2005-870322] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The role of intact proinsulin and adiponectin in endothelial dysfunction and insulin resistance has been receiving increasing attention. This study investigates the effect of PPARgamma stimulation or beta-cell stimulation on metabolic and vascular parameters in patients with type 2 diabetes. In our study, 173 type 2 diabetic patients were recruited and randomly assigned to pioglitazone 45 mg or glimepiride 1 - 6 mg treatment. Intima media thickness of the carotid artery, glycemic control, insulin resistance, adiponectin and intact proinsulin levels were assessed at baseline and after six months of treatment. Despite similar improvements in metabolic control (HbA (1c) after 24 weeks: - 0.8 +/- 0.9% [pioglitazone] vs. - 0.6 +/- 0.8% [glimepiride]; mean +/- SD; p < 0.0001, respectively), improvements in intima media thickness (- 0.033 +/- 0.052 mm; p < 0.0001), proinsulin intact (- 5.92 +/- 10.04 pmol/l; p < 0.0001), adiponectin (10.9 +/- 6.3 microg/ml; p < 0.0001) and HOMA score (- 2.21 +/- 3.40; p < 0.0001) were observed by pioglitazone but not glimepiride treatment. Reduction in intima media thickness was correlated with improved insulin sensitivity (r = 0.29; p = 0.0003), and proinsulin intact levels (r = 0.22; p = 0.006), while an inverse correlation was found with adiponectin levels (r = - 0.37; p < 0.0001). Measurement of adiponectin and intact proinsulin enables characterization of the metabolic situation and an estimation of atherosclerotic risk in patients with type 2 diabetes.
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Affiliation(s)
- T Forst
- Institute for Clinical Research and Development, Mainz, Germany.
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Pfützner A, Marx N, Lübben G, Langenfeld M, Walcher D, Konrad T, Forst T. Improvement of cardiovascular risk markers by pioglitazone is independent from glycemic control: results from the pioneer study. J Am Coll Cardiol 2005; 45:1925-31. [PMID: 15963388 DOI: 10.1016/j.jacc.2005.03.041] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2004] [Revised: 02/14/2005] [Accepted: 03/10/2005] [Indexed: 12/25/2022]
Abstract
OBJECTIVES This study was performed to assess whether the anti-inflammatory and antiatherogenic effects of pioglitazone suggested by animal experiments are reproducible in man and independent from improvements in metabolic control. BACKGROUND Type 2 diabetes is associated with increased cardiovascular risk. METHODS A total of 192 patients were enrolled into a six-month, prospective, open-label, controlled clinical study. They were randomized to receive either pioglitazone (45 mg) or glimepiride (1 to 6 mg, with the intent to optimize therapy). Biochemical and clinical markers to assess therapeutic effects included HbA1c, fasting glucose, insulin, adiponectin, lipids, high-sensitivity C-reactive protein (hsCRP), intracellular adhesion molecule, vascular cell adhesion molecule, vascular endothelial growth factor, fibrinogen, von Willebrand factor, matrix metalloproteinase (MMP)-9, monocyte chemoattractant protein (MCP)-1, soluble CD40 ligand, and carotid intima-media thickness (IMT). RESULTS The study was completed by 173 patients (66 female, 107 male; age [+/- SD]: 63 +/- 8 years; disease duration: 7.2 +/- 7.2 years; HbA1c: 7.5 +/- 0.9%; pioglitazone arm: 89 patients). A comparable reduction in HbA1c was seen in both groups (p < 0.001). In the pioglitazone group, reductions were observed for glucose (p < 0.001 vs. glimepiride group at end point), insulin (p < 0.001), low-density lipoprotein/high-density lipoprotein ratio (p < 0.001), hsCRP (p < 0.05), MMP-9 (p < 0.05), MCP-1 (p < 0.05), and carotid IMT (p < 0.001), and an increase was seen in high-density lipoprotein (p < 0.001) and adiponectin (p < 0.001). Spearman ranks analysis revealed only one correlation between the reduction in cardiovascular risk parameters and the improvement in the metabolic parameters (MMP-9 and fasting blood glucose, p < 0.05) CONCLUSIONS This prospective study gives evidence of an anti-inflammatory and antiatherogenic effect of pioglitazone versus glimepiride. This effect is independent from blood glucose control and may be attributed to peroxisome proliferator-activated receptor gamma activation.
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Affiliation(s)
- Andreas Pfützner
- IKFE-Institute for Clinical Research and Development, Parcusstrasse 8, D-55116 Mainz, Germany.
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Pfützner A, Standl E, Hohberg C, Konrad T, Strotmann HJ, Lübben G, Langenfeld MR, Schulze J, Forst T. IRIS II study: intact proinsulin is confirmed as a highly specific indicator for insulin resistance in a large cross-sectional study design. Diabetes Technol Ther 2005; 7:478-86. [PMID: 15929679 DOI: 10.1089/dia.2005.7.478] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND The cross-sectional IRIS-II study tried to assess the prevalence of insulin resistance and macrovascular disease in orally treated patients with Type 2 diabetes. METHODS In total, 4,270 patients were enrolled into the study (2,146 male, 2,124 female; mean +/- SD age 63.9 +/- 11.1 years; body mass index 30.1 +/- 5.5 kg/m2; duration of disease 5.4 +/- 5.6 years; hemoglobin A1c 6.8 +/- 1.3%). The study consisted of a single morning visit with completion of a standardized questionnaire and collection of a fasting blood sample. RESULTS The mean intact proinsulin value was 11.4 +/- 12.4 pmol/L (normal range < 10 pmol/L). Homeostasis model assessment resulted in 1,147 insulin-sensitive patients (26.9%) and 3,123 patients (73.1%) with insulin resistance. Of the latter patients 1,465 (34.3% of all patients) had also elevated intact proinsulin values, while 1,658 (38.8%) had no proinsulin elevation. In contrast, 1,042 (24.4%) of the insulin-sensitive patients had normal intact proinsulin, and only 105 (2.4%) had elevated intact proinsulin concentrations (chi2 test P < 0.0001). A specificity of 93.2% (sensitivity 46.9%) was calculated for elevated intact proinsulin as an indirect marker for insulin resistance. Of the 1,451 patients treated with sulfonylurea 52% had elevated intact proinsulin values and increased prevalence of cardiovascular complications (odds ratio 1.45). CONCLUSION Type 2 patients with elevated fasting intact proinsulin values can be regarded as being insulin resistant. The results confirm that fasting intact proinsulin is a suitable measure for beta-cell dysfunction and insulin resistance in type 2 diabetes and may be used to support therapeutic decisions.
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