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Lee J, Chun MH, Kim GJ, Shin DC, Kim DT, Shin S. Bunch-by-bunch position measurement and analysis at PLS-II. J Synchrotron Radiat 2017; 24:163-167. [PMID: 28009555 DOI: 10.1107/s1600577516018154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 11/11/2016] [Indexed: 06/06/2023]
Abstract
A bunch-by-bunch measurement system has been developed at Pohang Light Source II. The system consists of a four-channel button pick-up, 20 GHz sampling oscilloscope and an 800 MHz low-pass digital filter. Upon measuring a bunch-by-bunch spatio-temporal beam motion matrix over many turns, singular-value decomposition analysis is used to reveal the dominant coupled-bunch modes. The system can diagnose injection oscillations due to kicker errors and the effect of resistive-wall impedance that gives rise to instability during operation.
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Affiliation(s)
- Jaeyu Lee
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - M H Chun
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - G J Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - D C Shin
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - D T Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
| | - S Shin
- Pohang Accelerator Laboratory, POSTECH, Pohang, Kyungbuk 37673, Republic of Korea
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2
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Jeong J, Shin DC, Kim TH, Kim K. Prevalence of asymptomatic rotator cuff tear and their related factors in the Korean population. J Shoulder Elbow Surg 2017; 26:30-35. [PMID: 27497789 DOI: 10.1016/j.jse.2016.05.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 05/03/2016] [Accepted: 05/07/2016] [Indexed: 02/01/2023]
Abstract
BACKGROUND No information is available about asymptomatic rotator cuff tears (RCTs) in the Korean population. This study evaluated the prevalence of rotator cuff tears without symptoms and their related risk factors. MATERIALS AND METHODS The study included 486 volunteers (70.4% female; mean age, 53.1; range, 20-82 years) without any shoulder symptom complaints. Background data, medical history, clinical self-assessment, and physical examination were recorded. An ultrasonographic examination was conducted to identify rotator cuff pathology, but only full-thickness RCTs (FTRCTs) were included for the statistical analysis. RESULTS FTRCTs were found in 23 subjects (4.7%) but only in those aged ≥49 years. Subjects aged 50-59, 60-69, and ≥70 years of age had FTRCT prevalence rates of 3.5%, 13.3%, and 11.1%, respectively. The prevalence of FTRCTs was higher in subjects with diabetes (P = .042) and a smoking history (P= .002), but no differences were noted for the presence of thyroid disease (P = .051). Almost half of those who had FTRCTs had some pain and limited daily activity that was not bothersome. After excluding these subjects from the analysis, the prevalence of asymptomatic FTRCTs decreased to 2.3%. CONCLUSIONS The prevalence of asymptomatic FTRCTs was lower than expected. Half of asymptomatic FTRCTs were not actually symptom free after the clinical and physical assessments. The risk factors for a FTRCT were age, diabetes, and smoking.
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Affiliation(s)
- Jinyoung Jeong
- Department of Orthopedic Surgery, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
| | - Dong-Cheul Shin
- Department of Orthopedic Surgery, Suwon Nanoori hospital, Suwon, Republic of Korea
| | - Tae-Ho Kim
- Department of Orthopedic Surgery, Incheon Nanoori hospital, Incheon, Republic of Korea
| | - Kyungil Kim
- Department of Orthopedic Surgery, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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3
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Marmarelis VZ, Mitsis GD, Shin DC, Zhang R. Multiple-input nonlinear modelling of cerebral haemodynamics using spontaneous arterial blood pressure, end-tidal CO2 and heart rate measurements. Philos Trans A Math Phys Eng Sci 2016; 374:rsta.2015.0180. [PMID: 27044989 PMCID: PMC4822442 DOI: 10.1098/rsta.2015.0180] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/11/2016] [Indexed: 05/24/2023]
Abstract
In order to examine the effect of changes in heart rate (HR) upon cerebral perfusion and autoregulation, we include the HR signal recorded from 18 control subjects as a third input in a two-input model of cerebral haemodynamics that has been used previously to quantify the dynamic effects of changes in arterial blood pressure and end-tidal CO2upon cerebral blood flow velocity (CBFV) measured at the middle cerebral arteries via transcranial Doppler ultrasound. It is shown that the inclusion of HR as a third input reduces the output prediction error in a statistically significant manner, which implies that there is a functional connection between HR changes and CBFV. The inclusion of nonlinearities in the model causes further statistically significant reduction of the output prediction error. To achieve this task, we employ the concept of principal dynamic modes (PDMs) that yields dynamic nonlinear models of multi-input systems using relatively short data records. The obtained PDMs suggest model-driven quantitative hypotheses for the role of sympathetic and parasympathetic activity (corresponding to distinct PDMs) in the underlying physiological mechanisms by virtue of their relative contributions to the model output. These relative PDM contributions are subject-specific and, therefore, may be used to assess personalized characteristics for diagnostic purposes.
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Affiliation(s)
- V Z Marmarelis
- Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - G D Mitsis
- Bioengineering, McGill University, Montreal, Quebec, Canada
| | - D C Shin
- Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - R Zhang
- Institute for Exercise and Environmental Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Marmarelis VZ, Shin DC, Orme ME, Zhang R. Model-based physiomarkers of cerebral hemodynamics in patients with mild cognitive impairment. Med Eng Phys 2014; 36:628-37. [PMID: 24698010 DOI: 10.1016/j.medengphy.2014.02.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 02/17/2014] [Accepted: 02/26/2014] [Indexed: 02/02/2023]
Abstract
In our previous studies, we have introduced model-based "functional biomarkers" or "physiomarkers" of cerebral hemodynamics that hold promise for improved diagnosis of early-stage Alzheimer's disease (AD). The advocated methodology utilizes subject-specific data-based dynamic nonlinear models of cerebral hemodynamics to compute indices (serving as possible diagnostic physiomarkers) that quantify the state of cerebral blood flow autoregulation to pressure-changes (CFAP) and cerebral CO2 vasomotor reactivity (CVMR) in each subject. The model is estimated from beat-to-beat measurements of mean arterial blood pressure, mean cerebral blood flow velocity and end-tidal CO2, which can be made reliably and non-invasively under resting conditions. In a previous study, it was found that a CVMR index quantifying the impairment in CO2 vasomotor reactivity correlates with clinical indications of early AD, offering the prospect of a potentially useful diagnostic tool. In this paper, we explore the use of the same model-based indices for patients with amnestic Mild Cognitive Impairment (MCI), a preclinical stage of AD, relative to a control subjects and clinical cognitive assessments. It was found that the model-based CVMR values were lower for MCI patients relative to the control subjects.
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Affiliation(s)
- V Z Marmarelis
- Department of Biomedical Engineering & Biomedical Simulations Resource, University of Southern California, United States.
| | - D C Shin
- Department of Biomedical Engineering & Biomedical Simulations Resource, University of Southern California, United States
| | - M E Orme
- Sonovation Imaging & Diagnostics Inc., Los Angeles, CA, United States
| | - R Zhang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
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Marmarelis VZ, Shin DC, Orme ME, Zhang R. Model-based quantification of cerebral hemodynamics as a physiomarker for Alzheimer's disease? Ann Biomed Eng 2013; 41:2296-317. [PMID: 23771298 PMCID: PMC3992829 DOI: 10.1007/s10439-013-0837-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 05/29/2013] [Indexed: 01/27/2023]
Abstract
Previous studies have found that Alzheimer's disease (AD) impairs cerebral vascular function, even at early stages of the disease. This offers the prospect of a useful diagnostic method for AD, if cerebral vascular dysfunction can be quantified reliably within practical clinical constraints. We present a recently developed methodology that utilizes a data-based dynamic nonlinear closed-loop model of cerebral hemodynamics to compute "physiomarkers" quantifying the state of cerebral flow autoregulation to pressure-changes (CA) and cerebral CO2 vasomotor reactivity (CVMR) in each subject. This model is estimated from beat-to-beat measurements of mean arterial blood pressure, mean cerebral blood flow velocity and end-tidal CO2, which can be made reliably and non-invasively under resting conditions. This model may also take an open-loop form and comparisons are made with the closed-loop counterpart. The proposed model-based physiomarkers take the form of two indices that quantify the gain of the CA and CVMR processes in each subject. It was found in an initial set of clinical data that the CVMR index delineates AD patients from control subjects and, therefore, may prove useful in the improved diagnosis of early-stage AD.
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Affiliation(s)
- V Z Marmarelis
- University of Southern California, Los Angeles, CA, USA,
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Marmarelis VZ, Shin DC, Song D, Hampson RE, Deadwyler SA, Berger TW. On parsing the neural code in the prefrontal cortex of primates using principal dynamic modes. J Comput Neurosci 2013; 36:321-37. [PMID: 23929124 DOI: 10.1007/s10827-013-0475-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 11/25/2022]
Abstract
Nonlinear modeling of multi-input multi-output (MIMO) neuronal systems using Principal Dynamic Modes (PDMs) provides a novel method for analyzing the functional connectivity between neuronal groups. This paper presents the PDM-based modeling methodology and initial results from actual multi-unit recordings in the prefrontal cortex of non-human primates. We used the PDMs to analyze the dynamic transformations of spike train activity from Layer 2 (input) to Layer 5 (output) of the prefrontal cortex in primates performing a Delayed-Match-to-Sample task. The PDM-based models reduce the complexity of representing large-scale neural MIMO systems that involve large numbers of neurons, and also offer the prospect of improved biological/physiological interpretation of the obtained models. PDM analysis of neuronal connectivity in this system revealed "input-output channels of communication" corresponding to specific bands of neural rhythms that quantify the relative importance of these frequency-specific PDMs across a variety of different tasks. We found that behavioral performance during the Delayed-Match-to-Sample task (correct vs. incorrect outcome) was associated with differential activation of frequency-specific PDMs in the prefrontal cortex.
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Affiliation(s)
- V Z Marmarelis
- Department of Biomedical Engineering and the Biomedical Simulations Resource (BMSR), University of Southern California, Los Angeles, CA, 90089, USA,
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Song SW, Sur YJ, Shin DC. Complete dislocation of the thumb metacarpal with extreme displacement. J Plast Surg Hand Surg 2013; 48:91-3. [PMID: 23837506 DOI: 10.3109/2000656x.2012.760462] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study reports a rare case of complete dislocation of the thumb metacarpal with extreme displacement. Although there are several reported cases of similar injury in earlier published reports, metacarpals of all the cases remained in situ. In this case, the metacarpal was totally displaced out of the hand. Although open reduction and internal fixation were performed, the clinical outcome was unsatisfactory because of severe soft tissue damage.
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Affiliation(s)
- Seok-Whan Song
- Department of Orthopaedic Surgery, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea , Seoul , Korea
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Marmarelis VZ, Shin DC, Orme ME, Zhang R. Closed-loop dynamic modeling of cerebral hemodynamics. Ann Biomed Eng 2013; 41:1029-48. [PMID: 23292615 DOI: 10.1007/s10439-012-0736-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 12/26/2012] [Indexed: 11/28/2022]
Abstract
The dynamics of cerebral hemodynamics have been studied extensively because of their fundamental physiological and clinical importance. In particular, the dynamic processes of cerebral flow autoregulation (CFA) and CO2 vasomotor reactivity have attracted broad attention because of their involvement in a host of pathologies and clinical conditions (e.g., hypertension, syncope, stroke, traumatic brain injury, vascular dementia, Alzheimer's disease, mild cognitive impairment etc.). This raises the prospect of useful diagnostic methods being developed on the basis of quantitative models of cerebral hemodynamics, if cerebral vascular dysfunction can be quantified reliably from data collected within practical clinical constraints. This paper presents a modeling method that utilizes beat-to-beat measurements of mean arterial blood pressure, cerebral blood flow velocity and end-tidal CO2 (collected non-invasively under resting conditions) to quantify the dynamics of CFA and cerebral vasomotor reactivity (CVMR). The unique and novel aspect of this dynamic model is that it is nonlinear and operates in a closed-loop configuration.
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Affiliation(s)
- V Z Marmarelis
- University of Southern California, Los Angeles, CA, USA.
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Marmarelis VZ, Shin DC, Hampson RE, Deadwyler SA, Song D, Berger TW. Design of optimal stimulation patterns for neuronal ensembles based on Volterra-type hierarchical modeling. J Neural Eng 2012; 9:066003. [PMID: 23075519 DOI: 10.1088/1741-2560/9/6/066003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper presents a general methodology for the optimal design of stimulation patterns applied to neuronal ensembles in order to elicit a desired effect. The methodology follows a variant of the hierarchical Volterra modeling approach that utilizes input-output data to construct predictive models that describe the effects of interactions among multiple input events in an ascending order of interaction complexity. The illustrative example presented in this paper concerns the multi-unit activity of CA1 neurons in the hippocampus of a rodent performing a learned delayed-nonmatch-to-sample (DNMS) task. The multi-unit activity of the hippocampal CA1 neurons is recorded via chronically implanted multi-electrode arrays during this task. The obtained model quantifies the likelihood of having correct performance of the specific task for a given multi-unit (spatiotemporal) activity pattern of a CA1 neuronal ensemble during the 'sample presentation' phase of the DNMS task. The model can be used to determine computationally (off-line) the 'optimal' multi-unit stimulation pattern that maximizes the likelihood of inducing the correct performance of the DNMS task. Our working hypothesis is that application of this optimal stimulation pattern will enhance performance of the DNMS task due to enhancement of memory formation and storage during the 'sample presentation' phase of the task.
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Affiliation(s)
- V Z Marmarelis
- Department of Biomedical Engineering and the Biomedical Simulations Resource, University of Southern California, Los Angeles, CA 90089, USA.
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10
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Abstract
Cerebral Flow Autoregulation (CFA) is the dynamic process by which cerebral blood flow is maintained within physiologically acceptable bounds during fluctuations of cerebral perfusion pressure. The distinction is made with “static” flow autoregulation under steady-state conditions of perfusion pressure, described by the celebrated “autoregulatory curve” with a homeostatic plateau. This paper studies the dynamic CFA during changes in perfusion pressure, which attains critical clinical importance in patients with stroke, traumatic brain injury and neurodegenerative disease with a cerebrovascular component. Mathematical and computational models have been used to advance our quantitative understanding of dynamic CFA and to elucidate the underlying physiological mechanisms by analyzing the relation between beat-to-beat data of mean arterial blood pressure (viewed as input) and mean cerebral blood flow velocity(viewed as output) of a putative CFA system. Although previous studies have shown that the dynamic CFA process is nonlinear, most modeling studies to date have been linear. It has also been shown that blood CO2 tension affects the CFA process. This paper presents a nonlinear modeling methodology that includes the dynamic effects of CO2 tension (or its surrogate, end-tidal CO2) as a second input and quantifies CFA from short data-records of healthy human subjects by use of the modeling concept of Principal Dynamic Modes (PDMs). The PDMs improve the robustness of the obtained nonlinear models and facilitate their physiological interpretation. The results demonstrate the importance of including the CO2 input in the dynamic CFA study and the utility of nonlinear models under hypercapnic or hypocapnic conditions.
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Hampson RE, Marmaralis V, Shin DC, Gerhardt GA, Song D, Chan RHM, Sweatt AJ, Granacki J, Berger TW, Deadwyler SA. Restorative encoding memory integrative neural device: "REMIND". Annu Int Conf IEEE Eng Med Biol Soc 2012; 2011:3338-41. [PMID: 22255054 DOI: 10.1109/iembs.2011.6090905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Construction and application of a neural prosthesis device that enhances existing and replaces lost memory capacity in humans is the focus of research described here in rodents. A unique approach for the analysis and application of neural population firing has been developed to decipher the pattern in which information is successfully encoded by the hippocampus where mnemonic accuracy is critical. A nonlinear dynamic multi-input multi-output (MIMO) model is utilized to extract memory relevant firing patterns in CA3 and CA1 and to predict online what the consequences of the encoded firing patterns reflect for subsequent information retrieval for successful performance of delayed-nonmatch-to-sample (DNMS) memory task in rodents. The MIMO model has been tested successfully in a number of different contexts, each of which produced improved performance by a) utilizing online predicted codes to regulate task difficulty, b) employing electrical stimulation of CA1 output areas in the same pattern as successful cell firing, c) employing electrical stimulation to recover cell firing compromised by pharmacological agents and d) transferring and improving performance in naïve animals using the same stimulation patterns that are effective in fully trained animals. The results in rodents formed the basis for extension of the MIMO model to nonhuman primates in the same type of memory task that is now being tested in the last step prior to its application in humans.
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Affiliation(s)
- R E Hampson
- Department of Physiology of Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA
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Seo JY, Oh IS, Son IN, Kim KW, Shin DC, Ha KY. Pancreatic cancer metastasis presenting as an arachnoid cyst of the cervical spine: a case report. Eur J Orthop Surg Traumatol 2012. [DOI: 10.1007/s00590-011-0788-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Anandjiwala J, Seo JY, Ha KY, Oh IS, Shin DC. Adjacent segment degeneration after instrumented posterolateral lumbar fusion: a prospective cohort study with a minimum five-year follow-up. Eur Spine J 2011; 20:1951-60. [PMID: 21786038 DOI: 10.1007/s00586-011-1917-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 03/25/2011] [Accepted: 07/06/2011] [Indexed: 11/29/2022]
Abstract
PURPOSE To (1) clarify the role of various risk factors in the development of ASD, (2) compare instrumentation configuration with the development of ASD, (3) correlate the radiological incidence of ASD and its clinical outcome and (4) compare the clinical outcome between patients with radiological evidence of ASD and without ASD. METHODS This study prospectively examined 74 consecutive patients who underwent instrumented lumbar/lumbosacral fusion for degenerative disease with a minimum follow-up of 5 years. Among the patients, 68 were enrolled in the study. All of the patients had undergone preoperative radiological assessment and postoperative radiological assessment at regular intervals. The onset and progression of ASD changes were evaluated. The patients were divided in two groups: patients with radiographic evidence of ASD (group 1) and patients without ASD changes (group 2). Comprehensive analysis of various risk factors between group 1 and group 2 patients was performed. The Visual Analog Scale (VAS) was used to evaluate the clinical outcome and the functional outcome was evaluated using the Oswestry Disability Index (ODI) before and after surgery along with radiological assessment. RESULTS Radiographic ASD occurred in 20.6% (14/68) of patients. Preoperative disc degeneration at an adjacent segment was a significant risk factor for ASD. Other risk factors such as the age of a patient at the time of surgery, gender, preoperative diagnosis, length of fusion, instrumentation configuration, sagittal alignment and lumbar or lumbosacral fusion were not significant risk factors for the development of ASD. There was no correlation between ASD and its clinical outcome as determined at the final follow-up session. In addition, clinical outcome of patients with ASD and without ASD were not comparable. CONCLUSIONS Patients with preoperative disc degeneration at an adjacent segment were more at risk for the development of ASD. Other risk factors including instrumentation configuration were not significantly associated with ASD. There was no correlation between both the radiological development of ASD and its clinical outcome and the clinical outcome of patients with and without ASD.
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Affiliation(s)
- Jigar Anandjiwala
- Department of Orthopedic Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-Dong, Seocho-Ku, Seoul 137 040, Korea
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Marmarelis VZ, Shin DC, Song D, Hampson RE, Deadwyler SA, Berger TW. Dynamic nonlinear modeling of interactions between neuronal ensembles using principal dynamic modes. Annu Int Conf IEEE Eng Med Biol Soc 2011; 2011:3334-3337. [PMID: 22255053 DOI: 10.1109/iembs.2011.6090904] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present a novel methodology for modeling the interactions between neuronal ensembles that utilizes the concept of Principal Dynamic Modes (PDM) and their associated nonlinear functions (ANF). This new approach seeks to reduce the complexity of the multi-input/multi-output (MIMO) model of the interactions between neuronal ensembles--an issue of critical practical importance in scaling up the MIMO models to incorporate hundreds (or even thousands) of input-output neurons. Global PDMs were extracted from the data using estimated first-order and second-order kernels and singular value decomposition (SVD). These global PDMs represent an efficient "coordinate system" for the representation of the MIMO model. The ANFs of the PDMs are estimated from the histograms of the combinations of PDM output values that lead to output spikes. For initial testing and validation of this approach, we applied it to a set of data collected at the pre-frontal cortex of a non-human primate during a behavioral task (Delayed Match-to-Sample). Recorded spike trains from Layer-2 neurons were viewed as the "inputs" and from Layer-5 neurons as the outputs. Model prediction performance was evaluated by means of computed Receiver Operating Characteristic (ROC) curves. The results indicate that this methodology may greatly reduce the complexity of the MIMO model without significant degradation of performance.
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Affiliation(s)
- V Z Marmarelis
- Department of Biomedical Engineering and the Biomedical Simulations Resource, University of Southern California, Los Angeles, CA 90089, USA.
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Marmarelis VZ, Shin DC, Diaz-Arrastia R, Zhang R. Diagnostic biomarkers for Alzheimer's disease using dynamic nonlinear models based on Principal Dynamic Modes. Annu Int Conf IEEE Eng Med Biol Soc 2011; 2011:7119-7122. [PMID: 22255979 DOI: 10.1109/iembs.2011.6091799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Sensitive and robust diagnostic biomarkers for Alzheimer's disease (AD) were sought using dynamic nonlinear models of the causal interrelationships among time-series (beat-to-beat) data of arterial blood pressure, end-tidal CO(2) and cerebral blood flow velocity collected in human subjects (4 AD patients and 4 control subjects). These models were based on Principal Dynamic Modes (PDM) and yielded a reliable biomarker for AD diagnosis in the form of the "Effective CO(2) Reactivity Index" (ECRI). The results from this initial set of subjects corroborated the efficacy of the ECRI biomarker for accurate AD diagnosis.
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Affiliation(s)
- V Z Marmarelis
- Department of Biomedical Engineering and the Biomedical Simulations Resource, University of Southern California, Los Angeles, CA 90089, USA.
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Choung MG, Baek IY, Kang ST, Han WY, Shin DC, Moon HP, Kang KH. Isolation and determination of anthocyanins in seed coats of black soybean (Glycine max (L.) Merr.). J Agric Food Chem 2001; 49:5848-51. [PMID: 11743773 DOI: 10.1021/jf010550w] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Anthocyanin pigments in seed coats of black soybean (Glycine max (L.) Merr.) were extracted with 1% HCl-CH(3)OH, and the crude anthocyanin extract was purified by Shepadex LH-20 and Lichroprep RP-18 open-column chromatography. Three major anthocyanins were isolated, and their chemical structures were identified by spectroscopic methods (UV-visible, FABMS, (1)H and (13)C NMR, and by TLC). The complete structures of these anthocyanins were elucidated as delphinidin-3-glucoside, cyanidin-3-glucoside, and petunidin-3-glucoside. Among them, petunidin-3-glucoside was identified as a new anthocyanin in black soybeans. On the basis of RP-HPLC with a UV-vis detector, the contents of delphinidin-3-glucoside, cyanidin-3-glucoside, petunidin-3-glucoside, and total anthocyanins in seed coats of 10 black soybeans were found in the ranges of 0-3.71, 0.94-15.98, 0-1.41, and 1.58-20.18 mg/g, respectively. The results obtained in this study imply that the seed coats of black soybean can be used as a good source for cyanidin-3-glucoside and delphinidin-3-glucoside.
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Affiliation(s)
- M G Choung
- National Yeongnam Agricultural Experiment Station, Rural Development Administration, 1085, Naidong, Milyang, 627-803, Gyeongnam, Republic of Korea.
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Abstract
This study measured the levels of 17 congeners of PCDDs/PCDFs in serum to compare the levels between potentially exposed workers at an industrial waste incinerator and any residents with no known exposures. The 1,2,3,6,7,8- and 1,2,3,7,8,9-HxCDD were detected in serum of workers but in controls. Likewise, 1,2,3,7,8-PeCDF, 1,2,3,6,7,8- and 1,2,3,7,8,9-HxCDF were detected only in serum of workers. The international toxic equivalent (TEQ) levels of PCDDs/PCDFs in sera of workers are much higher than in controls. Among PCDDs, the proportion of total concentration and TEQ level is dominated predominantly by 1,2,3,6,7,8- and 1,2,3,7,8,9-HxCDD. We need extensive studies to estimate human exposure and are continuing this investigation.
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Affiliation(s)
- Y Kim
- Doping Control Center, Korea Institute of Science and Technology, Cheongryang, Seoul, South Korea.
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Shin DC, Kim HJ, Jung SH, Park CY, Lee SY, Kim CB. Pesticide poisoning and its related factors among Korean farmers. Med Lav 1999; 89 Suppl 2:S129-35. [PMID: 10217934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
This study has been carried out to assess the health damages due to pesticide use and its related risk factors among Korean farmers. Data regarding pesticide handling and poisoning symptoms were collected by means of a questionnaire filled in by 1,032 farmers from two provinces. The results showed that during summer farming 21.9% of the subjects experienced suspected pesticide poisoning. 18.8% mild poisoning, and 2% more serious poisoning. Univariate and logistic regression analyses between "no poisoning", including the "suspected poisoning" and "poisoning" groups, were performed to select significant variables related to pesticide poisoning. Four variables were significantly associated: sex, days of consecutive pesticide use, hours of pesticide use per day, having received safety education (weakly associated), and compliance with safety guidelines for application. Safety education was weakly associated with poisoning, while age, education, wearing protective gear, and compliance with safety guidelines for personal hygiene after pesticide use were not significant risk factors to determine pesticide poisoning.
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Affiliation(s)
- D C Shin
- Department of Preventive Medicine & Public Health, Yonsei University College of Medicine, China
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Shin DC, Chung Y, Park SE, Kim MS. BIOLOGICAL MONITORING OF BENZENE IN THE RESIDENTS LIVING NEAR PETROCHEMICAL INDUSTRY AREAS. Epidemiology 1998. [DOI: 10.1097/00001648-199807001-00049] [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: 11/25/2022]
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Abstract
Acute hepatitis E infection was diagnosed in a Pakistani immigrant admitted to the University of Illinois Hospital. Utilizing enzyme immunoassay (EIA) tests, specific IgG and IgM class antibodies to three different epitopes of hepatitis E virus (HEV) were detected 12 weeks after the onset of illness and in the early convalescent stage. Sixteen months after the onset of hepatitis, IgM anti-HEV was no longer detectable. Low levels of IgG class anti-HEV antibodies continued to be detected. We demonstrate the utility of the EIA HEV assay to diagnose prospectively acute HEV infection.
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Affiliation(s)
- L J DeGuzman
- Section of Digestive and Liver Diseases, University of Illinois at Chicago
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Abstract
Use of subjective indicators in the many efforts of comparative evaluation of community life has been confined primarily to the estimation of the proportions of people who are satisfied or dissatisfied with their life experiences. A sample of 1,488 persons in seven Illinois cities were interviewed by telephone and asked to rate their satisfaction with five community services. Findings showed that the measurement of central tendency characteristics of subjective indicators alone can result in an incomplete and misleading picture of the quality of community life.
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Shin TS, Kang HS, Choi KD, Lee KS, Shin DC. Pyroninophilic granules in liver cells of the mice treated with alpha-tocopherol and thioacetamide. Yonsei Med J 1972; 13:40-9. [PMID: 4668853 DOI: 10.3349/ymj.1972.13.1.40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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