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Krüger T, Behrens JR, Grobelny A, Otte K, Mansow-Model S, Kayser B, Bellmann-Strobl J, Brandt AU, Paul F, Schmitz-Hübsch T. Subjective and objective assessment of physical activity in multiple sclerosis and their relation to health-related quality of life. BMC Neurol 2017; 17:10. [PMID: 28086828 PMCID: PMC5237144 DOI: 10.1186/s12883-016-0783-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 12/09/2016] [Indexed: 12/02/2022] Open
Abstract
Background Physical activity (PA) is frequently restricted in people with multiple sclerosis (PwMS) and aiming to enhance PA is considered beneficial in this population. We here aimed to explore two standard methods (subjective plus objective) to assess PA reduction in PwMS and to describe the relation of PA to health-related quality of life (hrQoL). Methods PA was objectively measured over a 7-day period in 26 PwMS (EDSS 1.5–6.0) and 30 matched healthy controls (HC) using SenseWear mini® armband (SWAmini) and reported as step count, mean total and activity related energy expenditure (EE) as well as time spent in PA of different intensities. Measures of EE were also derived from self-assessment with IPAQ (International Physical Activity Questionnaire) long version, which additionally yielded information on the context of PA and a classification into subjects’ PA levels. To explore the convergence between both types of assessment, IPAQ categories (low, moderate, high) were related to selected PA parameters from objective assessment using ANOVA. Group differences and associated effect sizes for all PA parameters as well as their relation to clinical and hrQoL measures were determined. Results Both, SWAmini and IPAQ assessment, captured differences in PA between PwMS and HC. IPAQ categories fit well with common cut-offs for step count (p = 0.002) and mean METs (p = 0.004) to determine PA levels with objective devices. Correlations between specifically matched pairs of IPAQ and SWAmini parameters ranged between r .288 and r .507. Concerning hrQoL, the lower limb mobility subscore was related to four PA measures, while a relation with patients’ report of general contentment was only seen for one. Conclusions Both methods of assessment seem applicable in PwMS and able to describe reductions in daily PA at group level. Whether they can be used to track individual effects of interventions to enhance PA levels needs further exploration. The relation of PA measures with hrQoL seen with lower limb mobility suggests lower limb function not only as a major target for intervention to increase PA but also as a possible surrogate for PA changes. Electronic supplementary material The online version of this article (doi:10.1186/s12883-016-0783-0) contains supplementary material, which is available to authorized users.
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Ristow I, Li S, Demenescu R, Colic L, Li M, Walter H, Beier K, Krüger T, Schiffer B, Ponseti J, Walter M. EP 80. Sexual processing of pedophilic patients and healthy controls and the role of its metabolic markers – A fMRI and MRS study. Clin Neurophysiol 2016. [DOI: 10.1016/j.clinph.2016.05.129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hellwich O, Rose A, Bien T, Malolepszy C, Mucha D, Krüger T. PATIENT REGISTRATION USING PHOTOGRAMMETRIC SURFACE RECONSTRUCTION FROM SMARTPHONE IMAGERY. ACTA ACUST UNITED AC 2016. [DOI: 10.5194/isprsarchives-xli-b5-829-2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In navigated surgery the patient’s body has to be co-registered with presurgically acquired 3D data in order to enable navigation of the surgical instrument. For this purpose the body surface of the patient can be acquired by means of photogrammetry and co-registered to corresponding surfaces in the presurgical data. In this paper this task is exemplarily solved for 3D data of human heads using the face surface to establish correspondence. We focus on investigation of achieved geometric accuracies reporting positioning errors in the range of 1 mm.
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Reindl J, Pesek J, Krüger T, Wendler S, Nemitz S, Muckova P, Büchler R, Opitz S, Krieg N, Norgauer J, Rhode H. Proteomic biomarkers for psoriasis and psoriasis arthritis. J Proteomics 2016; 140:55-61. [DOI: 10.1016/j.jprot.2016.03.040] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/18/2016] [Accepted: 03/29/2016] [Indexed: 02/07/2023]
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Karck M, Conzelmann L, Easo J, Krüger T, Rylski B, Weigang E, Boening A. German Registry for Acute Aortic Dissection Type A: Structure, Results, and Future Perspectives. Thorac Cardiovasc Surg 2016; 65:77-84. [DOI: 10.1055/s-0036-1572436] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Behrens JR, Mertens S, Krüger T, Grobelny A, Otte K, Mansow-Model S, Gusho E, Paul F, Brandt AU, Schmitz-Hübsch T. Validity of visual perceptive computing for static posturography in patients with multiple sclerosis. Mult Scler 2016; 22:1596-1606. [PMID: 26814201 DOI: 10.1177/1352458515625807] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/14/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND Multiple sclerosis (MS) patients frequently have postural control impairment but quantitative posturography is difficult to perform in clinical care. Recent technology facilitates new posturography approaches. OBJECTIVE To evaluate construct validity of visual perceptive computing (VPC) for static posturography to study postural control in MS patients. METHODS A total of 90 MS patients and 59 healthy controls (HCs) performed three stance tests: open, closed and tandem stance. Static posturography was performed using a VPC system with Microsoft Kinect. Clinical assessments included Expanded Disability Status Scale (EDSS), Timed-25-Foot-Walk, Short-Maximum-Speed-Walk and 12-item MS Walking Scale (MSWS-12) questionnaire. Reliability was assessed with intra-class correlation coefficients at retest. RESULTS As a group, MS patients performed worse than HCs in all tests. The closed stance test showed best applicability and reliability. With closed eyes, in 36.7% of patients, the three-dimensional mean angular sway velocity (MSV-3D) was above HCs' 95th percentile. Higher MSV-3D was associated with decreased walking speed (p < 0.001); worse clinical scores, mainly attributable to the cerebellar functional system score (p < 0.001); and reflected in self-reported walking disability (MSWS-12, p < 0.001). CONCLUSION Postural control can be reliably assessed by VPC-based static posturography in patients with MS. Abnormal postural control seems to predominantly reflect involvement of cerebellar circuits with impact on gait and walking disability.
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Muñoz C, Beyersdorf F, Carrel T, Schönhoff F, Schlensak C, Krüger T, Eckstein HH, Reutersberg B, Erbel R, Janosi A, Siepe M, Rylski B. How Does the Aortic Geometry Change When the Descending Aorta Dissects? Thorac Cardiovasc Surg 2016. [DOI: 10.1055/s-0036-1571541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Hanf B, Krüger T, Mattern D, Kniemeyer O, Brakhage A. Adaption of the filamentous fungus Aspergillus Nidulans to low temperature stress. Cryobiology 2015. [DOI: 10.1016/j.cryobiol.2015.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Helm S, Kleimann A, Birkenstock A, Schuppner R, Bleich S, Krüger T, Kahl K, Frieling H. The use of ketamine in treatment-resistant major depression: a case study. PHARMACOPSYCHIATRY 2015. [DOI: 10.1055/s-0035-1557956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Krüger T, Veseli K, Schibilsky D, Wendel H, Lausberg H, Schneider W, Schlensak C. Regional and Directional Compliance of the Aortic Wall: ex vivo Dynamic Testing and Implications for Aortic Pathophysiology. Thorac Cardiovasc Surg 2015. [DOI: 10.1055/s-0035-1544481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Krüger T, Preuß H. Investigation of Some Sulphur Halides — An Application of the Pseudopotential Method. ACTA ACUST UNITED AC 2014. [DOI: 10.1515/zna-1983-0411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Semilocal pseudopotentials are used in combination with a density-functional approximation for the correlation energy and special optimized basis sets to investigate the sulphur halides SF, SF2, SF3, FSSF, SSF2, SCl, SCl2, ClSSCl and SSCl2. It turns out that the inclusion of d-orbitals in the basis set playes a significant role with respect to the quality of the calculated molecular parameters. Properties of SF3 are calculated for the first time, and the differences between the disulphur difluorides and the disulphur dichlorides are explained.
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Wohlfarth K, Fiedler T, Kollewe K, Wegner F, Weisemann J, Adeli G, Alvermann S, Böselt S, Escher C, Garde N, Gingele S, Kaehler SB, Karatschai R, Krüger T, Schmidt T, Sikorra S, Tacik P, Wollmann J, Dengler R, Bigalke H, Rummel A. BoNT/D is effective in humans – but with higher dosing and shorter duration than BoNT/A. KLIN NEUROPHYSIOL 2014. [DOI: 10.1055/s-0034-1371325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Krüger T, Walker T, Nolte A, Secker S, Greiner TO, Neumann B, Wendel HP, Schlensak C. Veins under pressure: The relationship of arterial pressure to adhesion molecule expression and leukocyte adhesion in venous bypass grafts. Thorac Cardiovasc Surg 2013. [DOI: 10.1055/s-0032-1332460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Tews I, Krüger T, Hebeler K, Schwenk A. Neutron matter at next-to-next-to-next-to-leading order in chiral effective field theory. PHYSICAL REVIEW LETTERS 2013; 110:032504. [PMID: 23373917 DOI: 10.1103/physrevlett.110.032504] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Indexed: 06/01/2023]
Abstract
Neutron matter presents a unique system for chiral effective field theory because all many-body forces among neutrons are predicted to next-to-next-to-next-to-leading order (N(3)LO). We present the first complete N(3)LO calculation of the neutron matter energy. This includes the subleading three-nucleon forces for the first time and all leading four-nucleon forces. We find relatively large contributions from N(3)LO three-nucleon forces. Our results provide constraints for neutron-rich matter in astrophysics with controlled theoretical uncertainties.
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Vörsmann P, Kaschwich C, Krüger T, Schnetter P, Wilkens CS. MEMS based integrated navigation systems for adaptive flight control of unmanned aircraft — State of the art and future developments. ACTA ACUST UNITED AC 2012. [DOI: 10.1134/s2075108712040116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Krüger T, Conzelmann LO, Bonser RS, Borger MA, Czerny M, Wildhirt S, Carrel T, Mohr FW, Schlensak C, Weigang E. Acute aortic dissection type A. Br J Surg 2012; 99:1331-44. [DOI: 10.1002/bjs.8840] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
Background
Acute aortic dissection type A (AADA) is a life-threatening vascular emergency. Clinical presentation ranges from pain related to the acute event, collapse due to aortic rupture or pericardial tamponade, or manifestations of organ or limb ischaemia. The purpose of this review was to clarify important clinical issues of AADA management, with a focus on diagnostic and therapeutic challenges.
Methods
Based on a MEDLINE search the latest literature on this topic was reviewed. Results from the German Registry for Acute Aortic Dissection Type A (GERAADA) are also described.
Results
Currently, the perioperative mortality rate of AADA is below 20 per cent, the rate of definitive postoperative neurological impairment approaches 12 per cent and the long-term prognosis after surviving the acute phase of the disease is good. Many pathology- and therapy-associated factors influence the outcome of AADA, including prompt diagnosis with computed tomography and better cerebral protection strategies during aortic arch reconstruction. Endovascular technologies are emerging that may lead to less invasive treatment options.
Conclusion
AADA is an emergency that can present with a wide variety of clinical scenarios. Advances in the surgical management of this complex disease are improving outcomes.
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Krüger T, Lisy M, Khalil M, Nagy Z, Lescan M, Stock UA, Schlensak S, Wildhirt SM. Matrix-based repair of acute Type-A aortic dissections as an alternative to conventional glue repair. Thorac Cardiovasc Surg 2012. [DOI: 10.1055/s-0031-1297859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Kornberger A, Kalender G, Krüger T, Lisy M, Schmid E, Wildhirt S, Stock UA. Is there evidence of “Aortic Dissections Weather”? Thorac Cardiovasc Surg 2012. [DOI: 10.1055/s-0031-1297857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Krüger T, Ghisari M, Yi C, Bonefeld-Jørgensen E. Levels and effect of serum pops on steroid hormone receptor function in Greenlandic Inuit. Toxicol Lett 2011. [DOI: 10.1016/j.toxlet.2011.05.1002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Krüger T, Varnik F, Raabe D. Particle stress in suspensions of soft objects. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2011; 369:2414-2421. [PMID: 21576155 DOI: 10.1098/rsta.2011.0090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In a suspension of extended objects such as colloidal particles, capsules or vesicles, the contribution of particles to the stress is usually evaluated by first determining the stress originating from a single particle (e.g. via integrating the fluid stress over the surface of a particle) and then adding up the contributions of individual particles. While adequate for a computation of the average stress over the entire system, this approach fails to correctly reproduce the local stress. In this work, we propose and validate a variant of the method of planes which overcomes this problem. The method is particularly suited for many-body interactions arising from, for example, shear and bending rigidity of red blood cells.
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Sack S, Schelp MK, Poppe S, Weber M, Krüger T, Geith S, Lieber M, Schleger S, Eichinger W, Menne J. [Aortic valve stenosis: transcatheter aortic valve implantation (TAVI) – transarterial or transapical approach]. Dtsch Med Wochenschr 2011; 136:417-26; quiz 427-30. [PMID: 21344357 DOI: 10.1055/s-0031-1274524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The calcified aortic stenosis is the dominating valve disease. Patients affected are most common elderly people in the 8 (th) or 9 (th) decade of their life who often show associated comorbidities like reduced left ventricular function, impaired renal function, pulmonary hypertension, and further diseases (Diabetes mellitus, stroke, COPD). In many cases perioperative morbidity and mortality are too high for surgical valve replacement and up to 30 % of patients are rejected. Nevertheless, prognosis of aortic stenosis is worse if the typical symptoms like dyspnea on exertion, syncope, and angina occur. The transcatheter aortic valve implantation is a new method treating this particular group of patients. The aortic valve bioprothesis consists of a balloon-expandable stent or a self-expandable frame, in which a valve of bovine or porcine pericardium is incorporated. The implantation is performed by retrograde access via the femoral or subclavian artery; the balloon-expandable prosthesis can also be implanted by transapical approach. Recently, the PARTNER trial and other studies demonstrate a high implantation success rate and better survival in comparison to standard therapy but exhibit also cerebral vascular and peripheral vascular complications. A further reduction of the available delivery systems and new types of valves which are under experimental tests and clinical evaluation contribute to this development.
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Krüger T, Varnik F, Raabe D. Second-order convergence of the deviatoric stress tensor in the standard Bhatnagar-Gross-Krook lattice Boltzmann method. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:025701. [PMID: 20866869 DOI: 10.1103/physreve.82.025701] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 06/15/2010] [Indexed: 05/29/2023]
Abstract
It is shown numerically that the deviatoric stress tensor is second-order accurate in the bulk Bhatnagar-Gross-Krook lattice Boltzmann (LB) method. In an earlier work [T. Krüger, Phys. Rev. E 79, 46704 (2009)], we have already predicted the second-order convergence. However, numerical simulations using a duct flow were not fully in line with this prediction. In particular, the convergence rate of the stress tensor was observed to depend on the LB boundary condition. In the present paper, we examine a pure bulk system, the decaying Taylor-Green vortex flow. Our prediction on the second-order accuracy of the stress tensor is unambiguously evidenced via these studies.
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Fallah MA, Myles VM, Krüger T, Sritharan K, Wixforth A, Varnik F, Schneider SW, Schneider MF. Acoustic driven flow and lattice Boltzmann simulations to study cell adhesion in biofunctionalized mu-fluidic channels with complex geometry. BIOMICROFLUIDICS 2010; 4:024106. [PMID: 20697583 PMCID: PMC2917880 DOI: 10.1063/1.3396449] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 03/26/2010] [Indexed: 05/06/2023]
Abstract
Accurately mimicking the complexity of microvascular systems calls for a technology which can accommodate particularly small sample volumes while retaining a large degree of freedom in channel geometry and keeping the price considerably low to allow for high throughput experiments. Here, we demonstrate that the use of surface acoustic wave driven microfluidics systems successfully allows the study of the interrelation between melanoma cell adhesion, the matrix protein collagen type I, the blood clotting factor von Willebrand factor (vWF), and microfluidic channel geometry. The versatility of the tool presented enables us to examine cell adhesion under flow in straight and bifurcated microfluidic channels in the presence of different protein coatings. We show that the addition of vWF tremendously increases (up to tenfold) the adhesion of melanoma cells even under fairly low shear flow conditions. This effect is altered in the presence of bifurcated channels demonstrating the importance of an elaborate hydrodynamic analysis to differentiate between physical and biological effects. Therefore, computer simulations have been performed along with the experiments to reveal the entire flow profile in the channel. We conclude that a combination of theory and experiment will lead to a consistent explanation of cell adhesion, and will optimize the potential of microfluidic experiments to further unravel the relation between blood clotting factors, cell adhesion molecules, cancer cell spreading, and the hydrodynamic conditions in our microcirculatory system.
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Gehling M, Arndt C, Eberhart LHJ, Koch T, Krüger T, Wulf H. Postoperative analgesia with parecoxib, acetaminophen, and the combination of both: a randomized, double-blind, placebo-controlled trial in patients undergoing thyroid surgery. Br J Anaesth 2010; 104:761-7. [PMID: 20427369 DOI: 10.1093/bja/aeq096] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND We assessed the analgesic efficacy of parecoxib, acetaminophen, and the combination of both compared with placebo in patients undergoing elective thyroid or parathyroid surgery. METHODS We randomized 140 patients to receive one of the following i.v. treatments using a double-blinded double-dummy technique: placebo, 80 mg 24 h(-1) parecoxib, 5 g 24 h(-1) acetaminophen, or 80 mg parecoxib plus 5 g acetaminophen. We provided rescue analgesia with piritramide delivered by a patient-controlled analgesia device. We measured opioid consumption and pain intensity over 24 h after operation. RESULTS Patient characteristic data, anaesthetic, and surgical characteristics of the patients in the four groups were similar. Parecoxib, acetaminophen, and the combination significantly reduced opioid requirements during 24 h after surgery [mean (sd) 12.5 (10.9) mg for parecoxib, 14.2 (12.3) mg for acetaminophen, and 11.9 (10.7) mg for combination] compared with placebo [23.5 (15.3) mg, P<0.05]. However, the combination of parecoxib and acetaminophen did not have any advantage over individual drugs in terms of opioid consumption in our trial (P>0.05). CONCLUSIONS Parecoxib and acetaminophen effectively reduce postoperative opioid requirements after thyroid or parathyroid surgery. The combination of these drugs is not associated with a further reduction in opioid consumption.
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Semper W, Kraft S, Krüger T, Nelson K. Theoretical Considerations: Implant Positional Index Design. J Dent Res 2009; 88:725-30. [DOI: 10.1177/0022034509341172] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Rotational freedom of implant positional indices in two-piece implants was investigated. The aim of the study was to determine, analytically, the rotational freedom of three different positional index designs, based on the hypothesis that it is not influenced by their geometric principle. Regular polygonal, polygon profile, and cam-groove patterns were analyzed. Schematic descriptions were made and idealized equations developed. Parameters influencing the extent of rotational freedom were identified for the different positional index designs. A general equation that describes the rotational freedom of differently designed indices was also formulated. The present analysis showed that the rotational freedom of positional indices can be analytically calculated and is influenced by different parameters. The rotational freedom of the positional index of commonly used implant-abutment connections depends on their geometric design and size.
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