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Tang XY, Xu MY, Hua YJ, Wang YY, Jiang T, Tang GH. [Three-dimensional finite element study on the effects of maxillary anterior two-step retraction and en-masse retraction with clear aligners]. Zhonghua Kou Qiang Yi Xue Za Zhi 2023; 58:670-676. [PMID: 37400197 DOI: 10.3760/cma.j.cn112144-20221222-00628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
Objective: To investigate the effects of two-step retraction and en-masse retraction on tooth movement pattern of anterior teeth and posterior anchorage with clear aligners using three-dimensional finite element analysis. Methods: A finite element model of maxillary first premolar extraction case undergoing clear aligner treatment was established based on maxillofacial cone-beam CT data of a 24-year-old adult male with individual normal occlusion, who visited Department of Oral Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine for impacted mandibular third molar in June, 2022. The initial tooth displacement of five anterior retraction protocols (two-step with canine retraction, two-step with incisor bodily retraction, two-step with incisor retraction-overtreatment, en-masse bodily retraction, and en-masse retraction-overtreatment) were evaluated. Results: Two step with canine retraction caused distal tipping of the canine and labial tipping of the incisors (0.18° for central incisor and 0.13° for lateral incisor). Two step with incisor retraction caused mesial tipping of the canine. In two step with bodily retraction protocol, uncontrolled lingual tipping was found in central incisor (0.29°) and lateral incisor (0.32°). In two-step with incisor retraction-overtreatment protocol, the movement pattern of the incisors didn't change, but the inclinations reduced to 0.21° and 0.18°. En-masse retraction caused distal tipping of the canine. In en-masse bodily retraction protocol, uncontrolled lingual tipping was also found in central incisor (0.19°) and lateral incisor (0.27°). In en-masse retraction-overtreatment protocol, the central incisor showed controlled lingual tipping (0.02°) and the lateral incisor showed palatal root movement (0.03° labial inclination). Posterior teeth exhibited mesial tipping in all five protocols. Conclusion: En-masse retraction with incisor overtreatment was beneficial to incisor torque control in clear aligner treatment.
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Affiliation(s)
- X Y Tang
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine & College of Stomatology, Shanghai Jiao Tong University & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, China
| | - M Y Xu
- Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Y J Hua
- Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Y Y Wang
- Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - T Jiang
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine & College of Stomatology, Shanghai Jiao Tong University & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, China
| | - G H Tang
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine & College of Stomatology, Shanghai Jiao Tong University & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, China
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Ludwig S, Conradi L, Cohen DJ, Coisne A, Scotti A, Abraham WT, Ben Ali W, Zhou Z, Li Y, Kar S, Duncan A, Lim DS, Adamo M, Redfors B, Muller DWM, Webb JG, Petronio AS, Ruge H, Nickenig G, Sondergaard L, Adam M, Regazzoli D, Garatti A, Schmidt T, Andreas M, Dahle G, Walther T, Kempfert J, Tang GH, Redwood SR, Taramasso M, Praz F, Fam NP, Dumonteil N, Obadia JF, von Bardeleben RS, Rudolph TK, Reardon MJ, Metra M, Denti P, Mack MJ, Hausleiter J, Asch FM, Latib A, Lindenfeld J, Modine T, Stone GW, Granada JF. Transcatheter Mitral Valve Replacement versus Medical Therapy for Secondary Mitral Regurgitation: A Propensity Score-Matched Comparison. Circ Cardiovasc Interv 2023. [PMID: 37194288 DOI: 10.1161/circinterventions.123.013045] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Background: Transcatheter mitral valve replacement (TMVR) is an emerging therapeutic alternative for patients with secondary mitral regurgitation (MR). Outcomes of TMVR versus guideline-directed medical therapy (GDMT) have not been investigated for this population. This study aimed to compare clinical outcomes of patients with secondary MR undergoing TMVR versus GDMT alone. Methods: The CHOICE-MI registry included patients with MR undergoing TMVR using dedicated devices. Patients with MR etiologies other than secondary MR were excluded. Patients treated with GDMT alone were derived from the control arm of the COAPT trial. We compared outcomes between the TMVR and GDMT groups, using propensity score (PS)-matching to adjust for baseline differences. Results: After PS-matching, 97 patient pairs undergoing TMVR (72.9±8.7 years, 60.8% male, transapical access 91.8%) versus GDMT (73.1±11.0 years, 59.8% male) were compared. At 1 and 2 years, residual MR was ≤1+ in all patients of the TMVR group compared to 6.9% and 7.7%, respectively, in those receiving GDMT alone (both p<0.001). The 2-year rate of HF hospitalization was significantly lower in the TMVR group (32.8% vs. 54.4%, HR 0.59, 95% CI 0.35-0.99; p=0.04). Among survivors, a higher proportion of patients were in NYHA functional class I or II in the TMVR group at 1 year (78.2% vs. 59.7%, p=0.03) and at 2 years (77.8% vs. 53.2%, p=0.09). Two-year mortality was similar in the two groups (TMVR vs. GDMT, 36.8% vs. 40.8%, HR 1.01, 95% CI 0.62-1.64; p=0.98). Conclusions: In this observational comparison, over 2-year follow-up, TMVR using mostly transapical devices in patients with secondary MR was associated with significant reduction of MR, symptomatic improvement, less frequent hospitalizations for HF and similar mortality compared with GDMT.
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Affiliation(s)
- Sebastian Ludwig
- Department of Cardiology, University Heart and Vascular Center Hamburg, Hamburg, Germany; German Center for Cardiovascular Research (DZHK): Partner site Hamburg/Kiel/Lübeck, Hamburg, Germany; Cardiovascular Research Foundation, New York, NY
| | - Lenard Conradi
- Department of Cardiovascular Surgery, University Heart and Vascular Center Hamburg, Hamburg, Germany
| | - David J Cohen
- Cardiovascular Research Foundation, New York, NY; St. Francis Hospital, Roslyn, NY
| | - Augustin Coisne
- Cardiovascular Research Foundation, New York, NY; Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011- EGID, F-59000 Lille, France
| | - Andrea Scotti
- Cardiovascular Research Foundation, New York, NY; Montefiore-Einstein Center for Heart and Vascular Care, Montefiore Medical Center, New York, NY
| | - William T Abraham
- Departments of Medicine, Physiology, and Cell Biology, Division of Cardiovascular Medicine, and the Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH
| | - Walid Ben Ali
- Structural Valve Program, Montreal Heart Institute, Montréal, Canada
| | - Zhipeng Zhou
- Cardiovascular Research Foundation, New York, NY
| | - Yanru Li
- Cardiovascular Research Foundation, New York, NY
| | - Saibal Kar
- Los Robles Regional Medical Center, Thousand Oaks, CA; Bakersfield Heart Hospital, Bakersfield, CA
| | | | - D Scott Lim
- Division of Cardiology, University of Virginia, Charlottesville, VA
| | - Marianna Adamo
- Cardiac Catheterization Laboratory and Cardiology, ASST Spedali Civili and Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Björn Redfors
- Cardiovascular Research Foundation, New York, NY; NewYork-Presbyterian Hospital/Columbia University Medical Center, New York, NY; Department of Cardiology, Sahlgrenska University Hospital, Gothenburg, Sweden and Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Sweden
| | - David W M Muller
- Cardiology Dept, St. Vincent's Hospital, Sydney, Australia and School of Clinical Medicine, UNSW Medicine and Health UNSW Sydney, NSW 2052, Australia
| | - John G Webb
- St. Paul's Hospital, Vancouver, British Columbia, Canada
| | - Anna Sonia Petronio
- Cardiac Catheterization Laboratory, Cardiothoracic and Vascular Department, University of Pisa, Pisa, Italy
| | - Hendrik Ruge
- German Heart Center Munich, Department of Cardiovascular Surgery, Munich, Germany; INSURE Institute for Translational Cardiac Surgery, Department of Cardiovascular Surgery, German Heart Center Munich, Germany
| | | | | | - Matti Adam
- Department of Cardiology, Heart Center, University of Cologne, Cologne, Germany
| | | | | | - Tobias Schmidt
- Medical Clinic II, University Heart Center Lübeck, Lübeck, Germany
| | - Martin Andreas
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Gry Dahle
- Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | | | | | - Gilbert Hl Tang
- Department of Cardiovascular Surgery, Mount Sinai Health System, New York, NY
| | | | | | - Fabien Praz
- Universitätsklinik für Kardiologie, Inselspital Bern, Bern, Switzerland
| | - Neil P Fam
- St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Nicolas Dumonteil
- Groupe CardioVasculaire Interventionnel, Clinique Pasteur Toulouse, Toulouse, France
| | | | | | - Tanja Katharina Rudolph
- Department of Interventional and General Cardiology, Heart- and Diabetes Center Nordrhine-Westphalia, Bad Oeynhausen, Ruhr University Bochum, Germany
| | | | - Marco Metra
- Cardiac Catheterization Laboratory and Cardiology, ASST Spedali Civili and Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | | | | | - Jörg Hausleiter
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München, Munich, Germany
| | - Federico M Asch
- Cardiovascular Core Laboratories, MedStar Health Research Institute, Washington, DC
| | - Azeem Latib
- Montefiore-Einstein Center for Heart and Vascular Care, Montefiore Medical Center, New York, NY
| | - JoAnn Lindenfeld
- Advanced Heart Failure and Cardiac Transplantation Section, Vanderbilt Heart and Vascular Institute, Nashville, TN
| | - Thomas Modine
- Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Gregg W Stone
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, NY
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Tang GH, Wang A, Markson LJ, Manning WJ, Strom JB. Risk factors for left ventricular thrombus formation on transthoracic echocardiography in a propensity-matched case control study. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.0145] [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: 11/12/2022] Open
Abstract
Abstract
Introduction
The specific risk factors for left ventricular thrombus (LVT) formation on transthoracic echocardiography (TTE) independent of age, sex, and left ventricular ejection fraction (LVEF) remain uncertain.
Purpose
To conduct a propensity-matched case control study of LVT.
Methods
We queried structured TTE report data from 113,673 patients at our institution to identify individuals with LVT on TTE, 2000–2011. Cases were matched 1:1 with controls on age, sex, LVEF, inpatient/outpatient status, image quality, test year, blood pressure, heart rate, height, and weight. using propensity scores. Risk factors for LVT formation were determined using medical chart review.
Results
Over 12 years, we identified 132 patients with LVT and 132 matched controls (mean age 62.0±16.1 years, 73.1% male, mean LVEF 27.0% ± 16.0%). Cases were similar to controls across all matched variables except height (cases vs. controls, mean height 172.2±8.8 vs. 174.8±9.3 cm, p=0.03). Compared with controls, TTEs for cases were more frequently performed for the indications of myocardial infarction (MI; 28.0% vs. 9.9%, p<0.001) and source of embolism (3.8% vs. 0.0%, p=0.008). Despite no differences between cases and controls in rates of hypertension, hyperlipidemia, diabetes, and thrombophilia (Table), a history of peripheral arterial disease was associated with a 3.4-fold increased odds of LVT formation (univariate odds ratio [OR], 3.35, 1.50–7.47, p=0.003). This association persisted despite adjustment for history of MI, stroke, height, history of recent major bleeding, and receipt of percutaneous coronary intervention (PCI) (adjusted OR, 4.33, 1.66–11.29, p=0.003). On presentation, 22.0% of cases were on anticoagulation including 20.5% on warfarin, none on a direct oral anticoagulant (DOAC), and 1.5% on heparin products. Additionally, 48.5% of cases were on antiplatelet medications. Of the 27 patients on warfarin on diagnosis of LVT, 25.9% had an International Normalized Range (INR) value <2.0. All TTE parameters were similar across groups (p>0.05 for all). Of those with LVT, 54 (40.9%) had LVT resolution over a median of 4.4 (0.9 to 13.6) months.
Conclusions
In this single center, propensity-matched case-control study of individuals with LVT on TTE, a history of peripheral arterial disease was associated with a 4.3-fold increased odds of LVT formation independent of age, sex, LVEF, history of MI, stroke, or PCI. Of those with LVT, anticoagulation was used on presentation in 22.0%. Nearly half had LVT resolution within 4.4 months.
Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The project was funded by a grant from the National, Heart, Lung, and Blood Institute (1K23HL144907 - Strom).
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Affiliation(s)
- G H Tang
- Beth Israel Deaconess Medical Center & Harvard Medical School, Department of Medicine, Boston, United States of America
| | - A Wang
- Beth Israel Deaconess Medical Center & Harvard Medical School, Department of Medicine, Boston, United States of America
| | - L J Markson
- Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, United States of America
| | - W J Manning
- Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, United States of America
| | - J B Strom
- Beth Israel Deaconess Medical Center & Harvard Medical School, Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology, Boston, United States of America
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Guo L, Tang GH, Kumar S. Dynamic Wettability on the Lubricant-Impregnated Surface: From Nucleation to Growth and Coalescence. ACS Appl Mater Interfaces 2020; 12:26555-26565. [PMID: 32419445 DOI: 10.1021/acsami.0c03018] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The surface dynamic wettability during droplet nucleation and growth involved with phase change is different from the static wettability formed from a sessile drop. Revealing this dynamic wettability of the lubricant-impregnated surfaces (LISs) and identification of the consistency between the wettability during condensation and the static wettability are of significant importance. In this study, we investigated condensation of water droplets on LISs using molecular dynamics simulations. All possible morphologies on LISs were investigated considering the effects of interfacial tension and lubricant thickness. The exploration of droplet behaviors from nucleation to growth and coalescence revealed four nucleation mechanisms and six growth modes. The lubricant was observed to be beneficial for the formation of droplets and maintaining dropwise condensation mode. The present investigation also established that the consistency between the wettability during condensation and the static wettability was determined by the solid-water-oil interface and the lubricant thickness. A map was proposed which helps in deciding whether the wettability during condensation is the same as the static wettability on LIS.
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Affiliation(s)
- Lin Guo
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - G H Tang
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Satish Kumar
- G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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5
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Abstract
Slippery liquid-infused porous surfaces (SLIPS) are gaining remarkable attention and have advanced performance in many fields. Although all SLIPS are related to lubricant-impregnation within nano/microstructures on a surface, they differ in many aspects, such as the morphology of droplets, the state of cloaking, the wetting edge, and the lubricant thickness. Requirements of the droplet morphology on SLIPS might change according to a specific application. A molecular-dynamics-based numerical model that can correctly simulate SLIPS is developed and is validated by comparing against the theoretical predictions for all possible stable states for a given droplet, lubricant, and solid surface. On the basis of this model, a detailed analysis of the equilibrium states is conducted. In particular, we discover that the four possible stable states on SLIPS predicted by theoretical studies can be extended to eight states by considering the effects of lubricant thickness and surface geometry in addition to the interfacial tension and surface wettability. These findings could be used to determine the conditions under which a thermodynamically stable state exists on SLIPS. The dynamic behavior of a nanodroplet on SLIPS is also studied, which provides insight into how a proper increase in the lubricant thickness might increase the sliding velocity. The above findings and developed model are expected to provide significant guidelines for designing SLIPS.
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Affiliation(s)
- Lin Guo
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering , Xi'an Jiaotong University , Xi'an 710049 , P.R. China
- G. W. Woodruff School of Mechanical Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - G H Tang
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering , Xi'an Jiaotong University , Xi'an 710049 , P.R. China
| | - Satish Kumar
- G. W. Woodruff School of Mechanical Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
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6
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Abstract
Heat transfer enhancement in dropwise condensation is widely investigated on a superhydrophobic surface with the advances in surface engineering, but the influence of a large amount of noncondensable gas (NCG) has not been clarified. In this work, the condensation heat transfer with a large amount of NCG is investigated by developing a multiphase lattice Boltzmann model for a multicomponent system. First, the condensation of a single droplet on a hydrophobic surface with NCG is simulated, demonstrating the capacity of the present model to capture the behaviors of different components during phase change and predict the significant influence of even a small fraction of the NCG on heat transfer. Then, solid surfaces with mixed wettability are built by introducing a fraction of hydrophilic parts to enhance heat transfer. It is found that there exists an optimized proportion which could maximize the condensation heat transfer efficiency corresponding to a specific mass fraction of NCG. Furthermore, the mechanism of this optimized proportion is revealed by examining the dynamic behaviors of condensation in a typical case, as a balance between a promotion of the nucleation rate and a put off of transition to filmwise condensation.
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Affiliation(s)
- L Y Shen
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering , Xi'an Jiaotong University , Xi'an 710049 , China
| | - G H Tang
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering , Xi'an Jiaotong University , Xi'an 710049 , China
| | - Q Li
- School of Energy Science and Engineering , Central South University , Changsha 410083 , China
| | - Y Shi
- School of Safety Science and Engineering , Xi'an University of Science and Technology , Xi'an 710054 , China
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7
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Price LZ, Faries PL, McKinsey JF, Prakash K, Tang GH, Kovacic JC, Tadros RO. The Epidemiology, Pathophysiology, and Novel Treatment of Calcific Arterial Disease. Surg Technol Int 2019; 34:351-358. [PMID: 30825317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Endovascular treatment of arterial diseases has become first-line in most cases due to improved technology. However, until recently, excessive atherosclerotic calcification has been a major limiting factor in the endovascular management of peripheral arterial disease, as well as vascular access for endovascular aneurysm repair (EVAR) and transcatheter aortic valve replacement (TAVR). The Peripheral Intravascular Lithotripsy (IVL) System (Shockwave Medical, Inc., Fremont California) applies pulsatile mechanical energy under fluoroscopic guidance to disrupt calcified lesions. The purpose of this paper is to introduce IVL in the treatment of calcific access vessels in preparation for EVAR and TAVR, as well as peripheral arterial disease applications to enhance luminal gain. Using the IVL System, angioplasty can be performed with lower pressures, which may minimize arterial dissection. Further, the lithotripsy effect on calcium will enhance vessel compliance. We describe several cases where IVL was applied successfully and present additional cases that may have benefitted from the use of this technology.
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Affiliation(s)
- Lucyna Z Price
- Department of Vascular Surgery, Mount Sinai Hospital, New York, New York
| | - Peter L Faries
- Department of Vascular Surgery, Mount Sinai Hospital, New York, New York
| | - James F McKinsey
- Mount Sinai West, Mount Sinai Health System, Division of Vascular Surgery, The Icahn School of Medicine at Mount Sinai, New York, New York
| | - Krishnan Prakash
- Department of Vascular Surgery, Mount Sinai Hospital, New York, New York
| | - Gilbert Hl Tang
- Cardiovascular Surgery, Icahn School of Medicine at Mount Sinai, Mount Sinai Health System, Department of Cardiovascular Surgery, Mount Sinai Health System New York, New York
| | - Jason C Kovacic
- Department of Vascular Surgery, Mount Sinai Hospital, New York, New York
| | - Rami O Tadros
- Division of Vascular Surgery, Icahn School of Medicine at Mount Sinai The Mount Sinai Medical Center, New York, New York
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Abstract
Runx2 is a transcription factor prerequisite for chondrocyte maturation and osteoblast differentiation. We tested the hypothesis that Runx2 is responsible for signaling chondrocyte maturation and endochondral ossification in the condyle during mandibular advancement. Fifty 35-day-old Sprague-Dawley rats were fitted with functional appliances for 3, 7, 14, 21, and 30 days. Experimental animals with 50 matched controls were labeled with bromodeoxyuridine for evaluation of the invasion of chondroclasts and osteoblasts into condylar cartilage. Mandibular advancement elicited Runx2 expression in condylar cartilage, and subsequently led to an expansion of type X collagen domain in the hypertrophic layer. Stronger Runx2 mRNA signals in subchondral bone corresponded with the increase in the recruitment of osteoblasts and chondroclasts, which preceded the increase of new bone formation in the condyle. Thus, Runx2 mediates chondrocyte terminal maturation and endochondral ossification in the mandibular condyle in response to mandibular advancement.
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Affiliation(s)
- G H Tang
- Hard tissue biology and repair research group and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong SAR, China
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9
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Abstract
Indian hedgehog (Ihh) is a critical mediator transducing mechanical signals to stimulate chondrocyte proliferation. To clarify the cellular signal transduction pathway that senses and converts mechanical signals into tissue growth in mandibular condyle, we evaluated Ihh expression and its relation to the kinetics of replicating mesenchymal cells in condylar cartilage during natural growth and mandibular advancement. Thirty-five-day-old Sprague-Dawley rats were fitted with functional appliances. Experimental animals with matched controls were doubly labeled with iododeoxyuridine and bromodeoxyuridine so that we could evaluate the cycles of the proliferative mesenchymal cells. Mandibular advancement triggered Ihh expression in condylar cartilage. A higher level of Ihh expression coincided with the increase of the replicating mesenchymal cells’ population and the shortening of the turnover time. These findings suggested that Ihh acts as a mediator of mechanotransduction that converts mechanical signals resulting from anterior mandibular displacement to stimulate cellular proliferation in condylar cartilage.
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Affiliation(s)
- G H Tang
- Hard Tissue Biology and Repair Research Group and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong SAR, China
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10
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Abstract
The effect of surface wettability on condensation heat transfer in a nanochannel is studied with the molecular dynamics simulations. Different from the conventional size, the results show that the filmwise mode leads to more efficient heat transfer than the dropwise mode, which is attributed to a lower interfacial thermal resistance between the hydrophilic surface and the condensed water compared with the hydrophobic case. The observed temperature jump at the solid-liquid surface confirms that the hydrophilic properties of the solid surface can suppress the interfacial thermal resistance and improve the condensation heat transfer performance effectively.
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Affiliation(s)
- D Niu
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - G H Tang
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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Abstract
Silica aerogel is almost transparent for wavelengths below 8 µm where significant energy is transferred by thermal radiation. The radiative heat transfer can be restricted at high temperature if doped with carbon powder in silica aerogel. However, different particle sizes of carbon powder doping have different spectral extinction coefficients and the doped carbon powder will increase the solid conduction of silica aerogel. This paper presents a theoretical method for determining the optimal carbon doping in silica aerogel to minimize the energy transfer. Firstly we determine the optimal particle size by combining the spectral extinction coefficient with blackbody radiation and then evaluate the optimal doping amount between heat conduction and radiation. Secondly we develop the Monte Carlo numerical method to study radiative properties of carbon-gradient-doped silica aerogel to decrease the radiative heat transfer further. The results indicate that the carbon powder is able to block infrared radiation and thus improve the thermal insulating performance of silica aerogel effectively.
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Abstract
OBJECTIVES Glycogen synthase kinase-3β (GSK-3β)/β-catenin signaling mediates osteogenesis in response to mechanical loading. We tested the hypothesis that local administration of a GSK-3β inhibitor could stimulate new bone formation in the expanding premaxillary suture. MATERIALS AND METHODS Thirty-five Sprague-Dawley rats were subjected to premaxillary suture expansion using a helix spring. The experimental rats were given one or two local injections of SB-415286, a small-molecule GSK-3β inhibitor. Animals were administered calcein and sacrificed on day 7 to quantify new bone formation. To evaluate the proliferation and differentiation of osteoblasts, rats were labeled with bromodeoxyuridine on day 1 and sacrificed on day 2 or 4. β-catenin expression was evaluated by immunohistochemical staining. RESULTS Two injections of SB-415286 led to an elevation of β-catenin expression and an increase in the number of proliferating osteoblasts in expanding sutures on day 2 and day 4. Consequently, new bone formation in the suture increased significantly on day 7. CONCLUSIONS These results suggest that local delivery of a GSK-3β inhibitor could stimulate bone formation in the expanding premaxillary suture by eliciting β-catenin signaling. GSK-3β could be a pharmaceutical target for improving the effect of orthodontic treatments such as rapid palatal expansion.
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Affiliation(s)
- Y Jiang
- Department of Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
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Abstract
Lithium is an activator of β-catenin signaling, and β-catenin mediates bone acquisition in response to mechanical loading in the bone. We tested the hypothesis that lithium enhances new bone formation during midpalatal suture expansion. Forty-eight Wistar rats with or without suture expansion were gavage-fed daily with lithium chloride or sodium chloride. We labeled the rats with bromodeoxyuridine to evaluate the proliferation and differentiation of the osteoprogenitors. Lithium increased β-catenin expression and cell proliferation in expanding sutures. Initial delay in the differentiation of osteoprogenitors into mature osteoblasts by lithium treatment corresponded with expansion of pre-osteoblasts, which preceded the increase of new bone formation in the suture. These results suggested that β-catenin regulates proliferation of osteoprogenitors and maturation of osteoblasts during midpalatal suture expansion osteogenesis, and that lithium enhances bone regeneration by elevating β-catenin expression. Lithium treatment could be a pharmaceutical aid to improve the stability of orthodontic treatment like rapid palatal expansion.
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Affiliation(s)
- G H Tang
- Department of Orthodontics, College of Stomatology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Road, Shanghai, 200011, China.
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Li Q, He YL, Tang GH, Tao WQ. Improved axisymmetric lattice Boltzmann scheme. Phys Rev E Stat Nonlin Soft Matter Phys 2010; 81:056707. [PMID: 20866354 DOI: 10.1103/physreve.81.056707] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Indexed: 05/29/2023]
Abstract
This paper proposes an improved lattice Boltzmann scheme for incompressible axisymmetric flows. The scheme has the following features. First, it is still within the framework of the standard lattice Boltzmann method using the single-particle density distribution function and consistent with the philosophy of the lattice Boltzmann method. Second, the source term of the scheme is simple and contains no velocity gradient terms. Owing to this feature, the scheme is easy to implement. In addition, the singularity problem at the axis can be appropriately handled without affecting an important advantage of the lattice Boltzmann method: the easy treatment of boundary conditions. The scheme is tested by simulating Hagen-Poiseuille flow, three-dimensional Womersley flow, Wheeler benchmark problem in crystal growth, and lid-driven rotational flow in cylindrical cavities. It is found that the numerical results agree well with the analytical solutions and/or the results reported in previous studies.
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Affiliation(s)
- Q Li
- National Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
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Li Q, He YL, Tang GH, Tao WQ. Lattice Boltzmann model for axisymmetric thermal flows. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 80:037702. [PMID: 19905256 DOI: 10.1103/physreve.80.037702] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2009] [Indexed: 05/28/2023]
Abstract
A thermal lattice Boltzmann (LB) model is presented for axisymmetric thermal flows in the incompressible limit. The model is based on the double-distribution-function LB method, which has attracted much attention since its emergence for its excellent numerical stability over the multispeed LB method. Compared with the existing axisymmetric thermal LB models, the present model is simpler and retains the inherent features of the standard LB method. Numerical simulations are carried out for the thermally developing laminar flows in circular ducts and the natural convection in an annulus between two coaxial vertical cylinders. The Nusselt number obtained from the simulations agrees well with the analytical solutions and/or the results reported in previous studies.
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Affiliation(s)
- Q Li
- National Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
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Tang GH, Zhang YH, Gu XJ, Barber RW, Emerson DR. Lattice Boltzmann model for thermal transpiration. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 79:027701. [PMID: 19391876 DOI: 10.1103/physreve.79.027701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 12/24/2008] [Indexed: 05/27/2023]
Abstract
The conventional Navier-Stokes-Fourier equations with no-slip boundary conditions are unable to capture the phenomenon of gas thermal transpiration. While kinetic approaches such as the direct simulation Monte Carlo method and direct solution of the Boltzmann equation can predict thermal transpiration, these methods are often beyond the reach of current computer technology, especially for complex three-dimensional flows. We present a computationally efficient nonequilibrium thermal lattice Boltzmann model for simulating temperature-gradient-induced flows. The good agreement between our model and kinetic approaches demonstrates the capabilities of the proposed lattice Boltzmann method.
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Affiliation(s)
- G H Tang
- Computational Science and Engineering Department, STFC Daresbury Laboratory, Warrington, WA4 4AD, United Kingdom.
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Tang GH, Gu XJ, Barber RW, Emerson DR, Zhang YH. Lattice Boltzmann simulation of nonequilibrium effects in oscillatory gas flow. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 78:026706. [PMID: 18850972 DOI: 10.1103/physreve.78.026706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 07/14/2008] [Indexed: 05/26/2023]
Abstract
Accurate evaluation of damping in laterally oscillating microstructures is challenging due to the complex flow behavior. In addition, device fabrication techniques and surface properties will have an important effect on the flow characteristics. Although kinetic approaches such as the direct simulation Monte Carlo (DSMC) method and directly solving the Boltzmann equation can address these challenges, they are beyond the reach of current computer technology for large scale simulation. As the continuum Navier-Stokes equations become invalid for nonequilibrium flows, we take advantage of the computationally efficient lattice Boltzmann method to investigate nonequilibrium oscillating flows. We have analyzed the effects of the Stokes number, Knudsen number, and tangential momentum accommodation coefficient for oscillating Couette flow and Stokes' second problem. Our results are in excellent agreement with DSMC data for Knudsen numbers up to Kn=O(1) and show good agreement for Knudsen numbers as large as 2.5. In addition to increasing the Stokes number, we demonstrate that increasing the Knudsen number or decreasing the accommodation coefficient can also expedite the breakdown of symmetry for oscillating Couette flow. This results in an earlier transition from quasisteady to unsteady flow. Our paper also highlights the deviation in velocity slip between Stokes' second problem and the confined Couette case.
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Affiliation(s)
- G H Tang
- Computational Science and Engineering Department, STFC Daresbury Laboratory, Warrington, WA4 4AD, United Kingdom.
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Tang GH, Tao WQ, He YL. Gas slippage effect on microscale porous flow using the lattice Boltzmann method. Phys Rev E Stat Nonlin Soft Matter Phys 2005; 72:056301. [PMID: 16383739 DOI: 10.1103/physreve.72.056301] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2005] [Indexed: 05/05/2023]
Abstract
A lattice Boltzmann method is developed for gaseous slip flow at the pore scale in microscale porous geometries. Flow characteristics through various porous structures are studied for different Knudsen numbers and inlet to outlet pressure ratios. It is found that the gas permeability is larger than the absolute permeability of porous media due to the gas slippage effect. Furthermore, the rarefaction influence on the gas permeability is more evident for porous structures with low porosity. The Klinkenberg equation is confirmed for the simulated porous structures. However, the second-order term of the Knudsen number (Kn2) cannot be neglected for gaseous flow with relatively high Knudsen numbers. A model for predicting the pressure drop of the flow through microscale porous media is presented based on the Ergun equation and the Carman-Kozeny equation by taking into account the effects of gas rarefaction and compressibility.
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Affiliation(s)
- G H Tang
- State Key Laboratory of Multiphase Flow, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
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Tang GH, Tao WQ, He YL. Thermal boundary condition for the thermal lattice Boltzmann equation. Phys Rev E Stat Nonlin Soft Matter Phys 2005; 72:016703. [PMID: 16090130 DOI: 10.1103/physreve.72.016703] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Indexed: 05/03/2023]
Abstract
A thermal boundary condition for a double-population thermal lattice Boltzmann equation (TLBE) is introduced and numerically demonstrated. The unknown distribution population at the boundary node is decomposed into its equilibrium part and nonequilibrium parts, and then the nonequilibrium part is approximated with a first-order extrapolation of the nonequilibrium part of the populations at the neighboring fluid nodes. Numerical tests with Dirichlet and Neumann boundary constraints show that the numerical results of the TLBE together with the present boundary schemes agree well with the analytical solutions and those of the finite-volume method.
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Affiliation(s)
- G H Tang
- State Key Laboratory of Multiphase Flow, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
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Abstract
PTHrP is a key factor regulating the pace of endochondral ossification during skeletal development. Mandibular advancement solicits a cascade of molecular responses in condylar cartilage. However, the pace of cellular maturation and its effects on condylar growth are still unknown. The purpose of this study was to evaluate the pattern of expression of PTHrP and correlate it to cellular dynamics of chondrocytes in condylar cartilage during natural growth and mandibular advancement. We fitted 35-day-old Sprague-Dawley rats with functional appliances. Experimental animals with matched controls were labeled with bromodeoxyuridine 3 days before their death, so that mesenchymal cell differentiation could be traced. Mandibular advancement increased the number of differentiated chondroblasts and subsequently increased the cartilage volume. Higher levels of PTHrP expression in experimental animals coincided with the slowing of chondrocyte hypertrophy. Thus, mandibular advancement promoted mesenchymal cell differentiation and triggered PTHrP expression, which retarded their further maturation to allow for more growth.
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Affiliation(s)
- A B M Rabie
- Hard Tissue Biology and Repair Research Group and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong SAR, China.
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Liu SC, Tang GH, Hu XQ. [Sperm autoimmunity in vasectomized men and its relation to atherosclerotic coronary heart disease--report of the detection of circulating antisperm antibodies in 707 cases]. Shengzhi Yu Biyun 2002; 7:20-4. [PMID: 12341306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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Ji GP, Cao HJ, Wen SE, Tang GH. [Congenital absence of upper anterior teeth a dentofacial morphologic analysis]. Shanghai Kou Qiang Yi Xue 2001; 10:305-8. [PMID: 14993957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
OBJECTIVE This study was designed to examine the dentofacial morphology of the children in Shanghai with congenital absence of upper anterior teeth. METHODS Cephalometric analysis for 37 children with congenital absence of upper anterior teeth was conducted and was compared with that of the normal ones. RESULTS (1) There was no significant difference in all measurements between gender. (2) Craniofacial defection included a small SNA a small ANB a small AoBo a small angle of convexity,and a large AB plane angle. Vertical facial dimensions which was shown by Y axis and mandibular plane angle significantly decreased. Examination for soft tissue also revealed a small convexity of soft tissue and a large CmSnUL. (3) A compensative proclination of the upper central incisors as well as the upper lip was also found. CONCLUSION Patients with congenital absence of upper anterior teeth might have a small maxilla a relatively normal mandibular dimension an anticlock rotation of the mandible plane, and a compensative proclination of the upper central incisors and the upper lip.
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Affiliation(s)
- G P Ji
- Department of Orthodontics, School of Stomatology, Shanghai Second Medical University, Shanghai 200011, China.
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Tang GH, Zhang L, Tang XL, Wang YX, Yin DZ. [Synthesis and determination for enantiomeric purity of 6-fluoro-L-DOPA]. Yao Xue Xue Bao 2001; 36:739-42. [PMID: 12579971] [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: 02/28/2023]
Abstract
AIM To study the synthesis and determination for enantiomeric purity of 6-fluoro-L-3, 4-dihydroxyphenylalanine (6-fluoro-L-DOPA, 6-FDOPA). METHODS 2-(2-Fluoro-4, 5-dimethoxybenzyl)-N-(diphenylmethylene) glycine tert-butyl ester (8), a new compound, was synthesized from the starting material nitroveratraldehyde via the nucleophilic displacement, reductive iodination, and chiral catalytic phase-transfer alkylation, and 6-FDOPA was prepared from hydrolysis of 8. The enantiomeric purity of 6-FDOPA was determined by HPLC method using a chiral mobil phase and reversed-phase C18 column. RESULTS The total time of synthesis was less than 90 min, the overall chemical yield from potassium fluoride was about 33%, and the enantiomeric purity was above 95%. CONCLUSION Large scale production of 6-FDOPA and automatic synthesis of 6-[18F]fluoro-L-DOPA with excellent chemical and entiomeric purity are available. The practical technique was provided for the radiochemical synthesis and entiomeric purity of 6-[18F]fluoro-L-DOPA.
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Affiliation(s)
- G H Tang
- Radiopharmaceutical Research Centre, Shanghai Institute of Nuclear Research, Chinese Academy of Sciences, Shanghai 201800, China.
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Cao HJ, Gong FF, Pan XG, Tang GH, Li DJ. [A clinical study on two forces orthodontic technique]. Shanghai Kou Qiang Yi Xue 2001; 10:210-3. [PMID: 14993992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
OBJECTIVE Two Forces Technique was introduced in order to extend its use in daily clinical practice. The advantages of this technique were also mentioned. METHODS Various kinds of malocclusion were treated by using Broussard brackets and auxiliary springs according to Two Forces Technique procedure. RESULTS Satisfied treatment results were achieved based on the comparison of cephalometrics before and after orthodontic treatment. CONCLUSION Auxiliary springs and light force were used in this technique, which moved teeth in three dimension precisely. It can be used in correction of various kinds of malocclusion and is easy to manipulate in clinics.
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Affiliation(s)
- H J Cao
- Department of Orthodontics, School of Stomatology, Ninth People's Hospital, Shanghai Second Medical University, Shanghai 200011, China
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Tang GH, Cao HJ, Pan XG, Wu JL, Cha W. [Treatment of CIID malocclusion with edgewise appliance and high pull J hood traction]. Shanghai Kou Qiang Yi Xue 2001; 10:179-80. [PMID: 14994055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- G H Tang
- Department of Orthodontics, Ninth People's Hospital, Shanghai Second Medical University, Shanghai 200011, China.
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Tang GH. [Positron emission tomography imaging and drug development]. Yao Xue Xue Bao 2001; 36:470-4. [PMID: 12585136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- G H Tang
- Nanfang PET Centre, Nan Fang Hospital, First Military Medical University, Guangzhou 510515, China.
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Tang GH, Tang XL. [Application of nuclear medicine techniques in drug development]. Yao Xue Xue Bao 2001; 36:390-5. [PMID: 12584866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- G H Tang
- Nanfang PET Centre, Nanfang Hospital, First Military Medical University, Guangzhou 510515, China.
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Law CM, Egger P, Dada O, Delgado H, Kylberg E, Lavin P, Tang GH, von Hertzen H, Shiell AW, Barker DJ. Body size at birth and blood pressure among children in developing countries. Int J Epidemiol 2001; 30:52-7. [PMID: 11171856 DOI: 10.1093/ije/30.1.52] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Studies in developed countries have shown that reduced fetal growth is related to raised blood pressure in childhood and adult life. Little is known about this association in developing countries, where fetal growth retardation is common. METHODS In 1994-1995, we measured blood pressure in 1570 3-6-year-old children living in China, Guatemala, Chile, Nigeria and Sweden. We related their blood pressure to patterns of fetal growth, as measured by body proportions at birth. The children were all born after 37 weeks gestation and weighed more than 2.5 kg at birth. RESULTS In each country, blood pressure was positively related to the child's current weight. After adjusting for this and gender, systolic pressure was inversely related to size at birth in all countries except Nigeria. In Chile, China and Guatemala, children who were proportionately small at birth had raised systolic pressure. For example, in Chile, systolic pressure adjusted for current weight increased by 4.9 mmHg (95% CI : 2.1, 7.7) for every kilogram decrease in birthweight, by 1 mmHg (95% CI : 0.4, 1.6) for every centimetre decrease in birth length, and by 1.3 mmHg (95% CI : 0.4, 2.2) for every centimetre decrease in head circumference at birth. In Sweden, systolic pressure was higher in children who were disproportionately small, that is thin, at birth. Systolic pressure increased by 0.3 mmHg (95% CI : 0.0, 0.6) for every unit (kg/m3) decrease in ponderal index at birth. These associations were independent of the duration of gestation. CONCLUSIONS Raised blood pressure among children in three samples from China, Central and South America is related to proportionate reduction in body size at birth, which results from reduced growth throughout gestation. The relation between fetal growth and blood pressure may be different in African populations. Proportionately reduced fetal growth is the prevalent pattern of fetal growth retardation in developing countries, and is associated with chronic undernutrition among women. Improvement in the nutrition and health of girls and young women may be important in preventing cardiovascular disease in developing countries.
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Affiliation(s)
- C M Law
- MRC Environmental Epidemiology Unit, Southampton General Hospital, Southampton SO16 6YD, UK.
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Tang GH, Jiang GH, Zheng LF. Pharmacokinetics of perlolyrine in rats by stable isotope dilution in conjunction with GC-MS. Acta Pharmacol Sin 2000; 21:660-2. [PMID: 11360678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
AIM To determine the pharmacokinetics of perlolyrine in rats. METHODS The plasma concentration and pharmacokinetic parameters of perlolyrine were determined by gas chromatography-mass spectrometry (GC-MS) with selected ion (m/z 247 and m/z 248) and [2-(15) N] perlolyrine (m/z 248) as internal standard. RESULTS The concentration-time profile of perlolyrine after ig perlolyrine 2 mg.kg-1 fitted a two-compartment open model in rats. The pharmacokinetic parameters were T1/2 alpha = 0.33 h, T1/2 beta = 4.52 h, T1/2 (ka) = 0.14 h, Tmax = 0.35 h, Cmax = 18.84 micrograms/L, K12 = 0.88 h-1, K21 = 0.42 h-1, K10 = 0.32 h-1, V/F = 109.22 L.kg-1, AUC = 112.68 micrograms.h.L-1. CONCLUSION The method was constant, sensitive, and accurate. It provides a useful method for the determination of pharmacokinetics of perlolyrine which are important for clinical use of perlolyrine.
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Affiliation(s)
- G H Tang
- Department of Nuclear Medicine, Nan Fang Hospital, First Military Medical University, Guangzhou 510515, China.
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Wu JL, Cao HJ, Wu ZP, Tang GH, Liu HH. [A study on dental and cranioficial structure of normal shanghai adults occlusion-I the craniofacial structure analysis with posterioanterior cephalometric roentgenography]. Shanghai Kou Qiang Yi Xue 2000; 9:23-6. [PMID: 15014843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
OBJECTIVE: To evaluate the characteristics of normal transverse craniofacial structure in Shanghai area and to establish the database of normal Shanghai adults occlusion for posterioanterior cephalometric roentgenography.METHODS:Posterioanterior-cephalometric of the 92 adults subjects with normalocclusion were measured and analysed by Jiffy orthodontic evaluation 5.0 software package.RESULTS:The database of normal Shanghai adults occlusion for posterioanterior cephalometric roentgenography was established. Transverse measurements were intercorrelated, no statistically significant gender differences were demonstrated in craniofacial width, while the molar overjet of male was larger than that of female.CONCLUSION:The normal transverse cranioficial structure in Shanghai area has its own characteristics. The established database would provide a foundation for the diagnosis and treatment of malocclusion.
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Affiliation(s)
- J L Wu
- Department of Orthodontics, School of Stomatology, Shanghai Second Medical University. Shanghai 200011, China
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Tao L, Pan XG, Wu JL, Tang GH, Chen RJ. [A Study On Dental and Craniofacial Structure Of Normal Shanghai Adults Occlusio-II The Dental Facial Symmetry Analysis with Posterioanterior Cephalometric Roentgenography]. Shanghai Kou Qiang Yi Xue 2000; 9:27-9. [PMID: 15014845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
OBJECTIVE:To evaluate the dental facial symmetry in normal Shanghai adults occlusion with posterioanterior cephalometric roentgenography. METHODS:Posterioanterior films of the 92 adults subjects with normal occlusion were measured. Five facial midlines commonly used in posterioanterior cephalometric were analyzed according to the middle structure index and side middle structure index. The midline deviations were measured. RESULTS:The middle line through ANS and perpendicular to zygomaticofrontal line has less mean of middle structure index and side middle structure index. There are midline deviations in population with normal occlusion.CONCLUSION:The facial midline mentioned above was suitable for posterioanterior cephalometrics, but the reliability is not absolute. Normal occlusion also has midline deviations. The asymmetry of face was larger than that of dental occlusion.
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Affiliation(s)
- L Tao
- Department of Orthodontics, School of Stomatology, Shanghai Second Medical University. Shanghai 200011, China
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Lu J, Tang GH, Cao HJ, Zhang CW, Weng SE. [A comparative study of elastomeric chains force delivery properties]. Shanghai Kou Qiang Yi Xue 1997; 6:154-5. [PMID: 15160219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
In this study,four different kinds and three different length elastomeric chains were tested to compare their force delivery properties.It suggested that different kind and length chains should be selected to generate optimal orthodontic forces clinically.
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Affiliation(s)
- J Lu
- Department of Orthodontics, Ninth People's Hospital, School of Stomatology,Shanghai Second Medical University. Shanghai 200011, China
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Tang GH, Liu K, Cao HJ, Lu J, Zhang CW. [Properies of orthodontic wires in simulated teeth alignment test]. Shanghai Kou Qiang Yi Xue 1997; 6:156-8. [PMID: 15160220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
In this study,methods were developed to test and compare leveling archwires that commonly used in domestic practice.The results showed that the stainless steel arch wires were stiff.The Ni-Ti wires and the wires with loops were flexible and could deliver more constant force.The 0.014 Chinese Ni-Ti wires demonstrated the superelastic property,but 0.016 Ni-Ti wire did not appear the same property before they generated 250g force.
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Affiliation(s)
- G H Tang
- Department of Orthodontic, Ninth People's Hospital, School of Stomatology,Shanghai Second Medical University. Shanghai 200011, China
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Cao HJ, Pan XG, Tang GH. [TWEED technique in orthodontics: Part III]. Shanghai Kou Qiang Yi Xue 1997; 6:179-81. [PMID: 15160228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- H J Cao
- Department of Orthodontics, Ninth People's Hospital, School of Stomatology,Shanghai Second Medical University. Shanghai 200011, China
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Tang GH, Liu K, Cao HJ, Lu J, Zhang CW. [Orthodontic wires in a simulated oral environment:change in mechanical properties]. Shanghai Kou Qiang Yi Xue 1997; 6:159-62. [PMID: 15160221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
In this study,some different kinds of orthodontic archwires were tested to evaluate the changes of their mechanical properties.The results showed that in oral environment,all wires suffered degradation of their properties:the force-generating capacity decreased and the permanent deformation increased.The force-generating capacity decreased and the permanent deformation increased.The force decay resulted mainly from the tooth movement.The deformation occurred within 7 days.Chinese-NiTi alloy suffered less stress-relaxation and residual deformation than the stainless steel wires.Arch wires with vertical loops showed similar properties with NiTi,which could deliver more constant force.
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Affiliation(s)
- G H Tang
- Department of Orthodontic, Ninth People's Hospital, School of Stomatology,Shanghai Second Medical University. Shanghai 200011, China
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Cao HJ, Pan XG, Tang GH. [TWEED technique in orthodontics: Part II]. Shanghai Kou Qiang Yi Xue 1997; 6:53-6. [PMID: 15159971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- H J Cao
- Departmetn of Orthodontics, Ninth People's Hospital, School of Stomatology, Shanghai Second Medical University. Shanghai 200011,China
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Cao HJ, Pan XG, Tang GH. [TWEED technique for orthodontics: Part I]. Shanghai Kou Qiang Yi Xue 1996; 5:172-3. [PMID: 15160015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- H J Cao
- Department Of Orthodontics,School of Stomatology, Shanghai Second Medical University. Shanghai 200011,China
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Yu JH, Guo J, Guo J, Zeng FX, Tang GH. [The inhibitory effect and its mechanism of transferrin on FSH-induced differentiation of granulosa cells]. Sheng Li Xue Bao 1994; 46:209-16. [PMID: 7973806] [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: 01/28/2023]
Abstract
Transferrins are a class of related metal-binding transport glycoproteins for transporting iron to various organs and tissues of the body. In recent years, it has been reported that the transferrin can play an important role in the local regulation of ovarian function, apart from its iron-binding characteristic. Transferrin could attenuate FSH-induced differentiation of rat and human granulosa cells and its mechanisms were considered as follows: (1) Transferrins partially blocked the binding of FSH with its receptors on granulosa cells and reduced the formation of intracellular cAMP, and therefore inhibited the expression of FSH receptors. (2) Acting sites beyond cAMP formation also existed for the inhibitory effect of transferrin on inhibin and estradiol production. (3) The inhibitory effect of transferrin seemed not to be involved in the changes of protein kinase C activity, the calcium release and "proliferation-differentiation reversed mechanism" in granulosa cells.
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Affiliation(s)
- J H Yu
- Department of Reproductive Physiology, Sichuan Family Planning Research Institute, WHO Collaborating Center for Research in Human Reproduction, Chengdu
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Tang GH, Zhong YH, Ma YM, Luo L, Cui K, Luo J, Zhang GH, An IM, Luo DC, Qiu SH. Vasectomy and health: cardiovascular and other diseases following vasectomy in Sichuan province, People's Republic of China. Int J Epidemiol 1988; 17:608-17. [PMID: 3209341 DOI: 10.1093/ije/17.3.608] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The long-term sequelae of vasectomy were studied in a retrospective cohort study of 4596 vasectomized and 4340 nonvasectomized farmers from eight rural communes in Sichuan, People's Republic of China. The mean duration since the operation was 14.5 years with a range of 10 to 25 years. At the time of evaluation the vasectomized men were generally healthier than the non-vasectomized for a wide range of health indicators including clinical signs of cardiovascular disease, resting ECG changes, positive ECG changes following a maximal stress test, or fundus abnormalities. The lack of association between vasectomy and cardiovascular disease noted in Europe and the USA is supported by the present study conducted in a population with a low prevalence of cardiovascular disease and risk factors.
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Affiliation(s)
- G H Tang
- Sichuan Provincial Family Planning Research Institute, Chengdu, People's Republic of China
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Liu SC, Tang GH. Sperm autoimmunity in vasectomized men and its relationship to atherosclerotic coronary artery disease. Clin Reprod Fertil 1985; 3:343-8. [PMID: 3830362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A study is reported of sperm autoimmunization in 707 men and its relationship with atherosclerotic coronary artery disease. The following groups were studied: healthy vasectomized men (278), healthy non-vasectomized men (231), vasectomized men with atherosclerotic coronary disease (ACD; 87) and non-vasectomized men with ACD(111). The gelatin agglutination test (GAT), tube slide agglutination test (TSAT) and sperm immobilization test (SIT) were used to detect circulating anti-sperm antibodies. Sperm antibodies developed within 6 months of vasectomy and persisted for more than 20 years. There was no difference in the incidence of antibodies in vasectomized healthy and ACD men. The results of this study provide no evidence for an association between cardiac disease and vasectomy.
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