Contribution of Palmar Radiocarpal and Ulnocarpal Ligaments to the Stability of the Canine Antebrachiocarpal Joint

2019 ◽  
Vol 32 (04) ◽  
pp. 305-313
Author(s):  
Joshua Milgram ◽  
Jonathan Stockman ◽  
Gilad Segev ◽  
Yaron Meiner ◽  
Anna Shipov
Keyword(s):  
Clinical Relevance ◽  
Motion Tracking ◽  
Testing Machine ◽  
Joint Position ◽  
Joint Stability ◽  
Custom Made ◽  
Metacarpal Bones ◽  
The Stability ◽  
Musculoskeletal Pathology ◽  
The Right

Objective The aim of this study was to evaluate the contribution of the palmar radiocarpal ligament and the palmar ulnocarpal ligament to canine antebrachiocarpal joint stability. Materials and Methods The right carpus of four dog cadavers, free of musculoskeletal pathology, was stripped of muscle. Each specimen was placed into a custom-made joint testing machine and tested at 15° extension, and 0° and 15° flexion. A single motion tracking sensor was fixed to the metacarpal bones. All specimens were tested with all ligaments intact and after transection of the palmar radiocarpal and ulnocarpal ligaments. A range of weights between 0.2 and 2.0 kg was used to test the carpi in three directions (axial, medial/lateral and cranial/caudal) and two moments (pronation/supination and valgus/varus). Results No differences were found between the translations and rotations of the manus relative to the radius and ulna with the ligaments intact and the ligaments transected at any of the carpal angles tested, except at 15° of flexion. Increasing the angle of flexion resulted in a significant increase in cranial and caudal translation of the manus relative to the radius and ulna both in the intact and transected specimens. Clinical relevance Antebrachiocarpal joint position plays a more important role in craniocaudal antebrachiocarpal joint stability than the palmar radiocarpal and ulnocarpal ligaments.

INFLUENCE OF DIETARY CALCIUM-PHOSPHORUS LEVELS ON CERTAIN MECHANICAL, PHYSICAL AND HISTOLOGICAL PROPERTIES AND CHEMICAL COMPOSITION OF BONES IN GILTS AND SECOND LITTER SOWS

1986 ◽  
Vol 66 (2) ◽  
pp. 495-503 ◽  
Author(s):  
R. R. GRANDHI ◽  
A. B. THORNTON-TRUMP ◽  
C. E. DOIGE
Keyword(s):  
Elastic Modulus ◽  
Testing Machine ◽  
National Research Council ◽  
Bending Moment ◽  
Dietary Calcium ◽  
National Academy Of Sciences ◽  
Metacarpal Bones ◽  
Calcium Phosphorus ◽  
The Right ◽  
Lactation Cycle

A 24 factorial design of treatments involving two breeds (Lacombe (L) and Yorkshire (Y)) and two dietary calcium-phosphorus (Ca-P) levels (100% or 150% of 1979 National Academy of Sciences-National Research Council recommended Ca-P levels) during finishing, gestation and lactation periods, was used to study the changes in certain mechanical, physical, chemical and histological characteristics of bones in gilts and second litter sows. Femur, 3rd metacarpal and 6th rib bones were collected from the right half of the 32 (16L + 16Y) gilts slaughtered at 159 ± 1 d of age and 46 (22L + 24Y) second litter sows slaughtered at the end of second gestation-lactation cycle. The mechanical properties, breaking force, bending moment, breaking stress and elastic modulus of femur and 3rd metacarpal bones, determined by flexture tests using an Instron Universal Testing Machine, were not significantly (P > 0.05) influenced by the dietary Ca-P levels in gilts or sows. Feeding 150% of NRC Ca-P levels during the finishing period increased (P < 0.05) the bone shaft diameter (23.2 ± 0.2 vs.22.3 ± 0.2 mm) in femurs and percent bone ash (60.5 ± 0.4 vs. 59.0 ± 0.4) and percent bone Ca (19.0 ± 0.5 vs. 17.0 ± 0.5) in 3rd metacarpals of gilts. The femurs and 3rd metacarpals of L gilts and sows had generally larger shaft diameters but lower bone strength, elastic modulus and bone cortex thickness than in Y pigs. The histological examination revealed no abnormalities in trabecular and cartilage structures of 6th ribs between sows fed different Ca-P levels. The results suggested that feeding 150% of NAS-NRC Ca-P levels during finishing, gestation and lactation periods produced some positive changes in bone characteristics of gilts and second litter sows with no identifiable changes in their ability to function. Certain bone characteristics were different between the two breeds and their response to dietary Ca-P levels varied between femur and 3rd metacarpals of gilts and sows. Key words: Calcium, phosphorus, bone characteristics, gilts, sows

Epitaxial Growth in Dislocation-Free Strained Alloy Films

2002 ◽  
Vol 715 ◽  
Author(s):  
Zhi-Feng Huang ◽  
Rashmi C. Desai
Keyword(s):  
Deposition Rate ◽  
Elastic Moduli ◽  
Composition Dependence ◽  
Critical Thickness ◽  
Lattice Misfit ◽  
Misfit Strain ◽  
Joint Stability ◽  
Alloy Films ◽  
The Stability ◽  
Stability Results

AbstractThe morphological and compositional instabilities in the heteroepitaxial strained alloy films have attracted intense interest from both experimentalists and theorists. To understand the mechanisms and properties for the generation of instabilities, we have developed a nonequilibrium, continuum model for the dislocation-free and coherent film systems. The early evolution processes of surface pro.les for both growing and postdeposition (non-growing) thin alloy films are studied through a linear stability analysis. We consider the coupling between top surface of the film and the underlying bulk, as well as the combination and interplay of different elastic effects. These e.ects are caused by filmsubstrate lattice misfit, composition dependence of film lattice constant (compositional stress), and composition dependence of both Young's and shear elastic moduli. The interplay of these factors as well as the growth temperature and deposition rate leads to rich and complicated stability results. For both the growing.lm and non-growing alloy free surface, we determine the stability conditions and diagrams for the system. These show the joint stability or instability for film morphology and compositional pro.les, as well as the asymmetry between tensile and compressive layers. The kinetic critical thickness for the onset of instability during.lm growth is also calculated, and its scaling behavior with respect to misfit strain and deposition rate determined. Our results have implications for real alloy growth systems such as SiGe and InGaAs, which agree with qualitative trends seen in recent experimental observations.

Symmetrizable Difference Dchemes

2005 ◽  
Vol 5 (1) ◽  
pp. 3-50 ◽  
Author(s):  
Alexei A. Gulin
Keyword(s):  
Initial Data ◽  
Difference Scheme ◽  
Difference Schemes ◽  
Time Dependent ◽  
Stability Boundaries ◽  
Typical Representative ◽  
Variable Weight ◽  
The Stability ◽  
Conditions Of Stability ◽  
The Right

AbstractA review of the stability theory of symmetrizable time-dependent difference schemes is represented. The notion of the operator-difference scheme is introduced and general ideas about stability in the sense of the initial data and in the sense of the right hand side are formulated. Further, the so-called symmetrizable difference schemes are considered in detail for which we manage to formulate the unimprovable necessary and su±cient conditions of stability in the sense of the initial data. The schemes with variable weight multipliers are a typical representative of symmetrizable difference schemes. For such schemes a numerical algorithm is proposed and realized for constructing stability boundaries.

Pemanfaatan Metil Ester Sulfonat pada Pembuatan Deterjen Cair

2016 ◽  
Vol 7 (14) ◽  
pp. 143-155
Author(s):  
Eldha Sampepana ◽  
Suroto Hadi Saputra
Keyword(s):  
Fatty Acids ◽  
Methyl Ester ◽  
Linear Alkylbenzene Sulfonate ◽  
Emulsion Stability ◽  
Alcohol Sulfate ◽  
Stable Emulsion ◽  
Linear Alkylbenzene ◽  
Alkylbenzene Sulfonate ◽  
The Stability ◽  
The Right

In the manufacture of detergents still using surfactants (which serves as an emulsifier) of crude oil in the form of the AS. (alcohol sulfate) and LAS (linear alkylbenzene sulfonate), where this type of surfactant cannot be degraded by microorganisms when discharged into the environment, causing environmental pollution. Methyl ester sulfonate surfactant is an anionic surfactant which has a composition of C16 - C18 fatty acids are capable of acting against nature deterjensinya, while the C12 - C14 fatty acids contribute to the foaming effect. The purpose of this study was to look for the formulation of methyl ester sulfonate (MES) the right to produce a good detergent by using materials such as methyl ester sulfonate surfactant self-made, methyl ester sulfonate and sodium lauryl market Ester Sulfate (SLS) with a concentration of 15 %, 20 % and 25 %. Detergent results of the study have high detergency ( net ) compared with the detergency of detergent commercial, have a stable emulsion stability, the stability of the foam/foam detergent power made from methyl ester sulfonate surfactant produces less foam, compared with a detergent made from SLS and surfactant SNI 06-4075-1996 standards.

A custom-made neoprene thumb carpometacarpal orthosis with thermoplastic stabilization: An orthosis that promotes function and improvement in patients with the first carpometacarpal joint osteoarthritis

2013 ◽  
Vol 38 (1) ◽  
pp. 79-82 ◽  
Author(s):  
Monireh Ahmadi Bani ◽  
Mokhtar Arazpour ◽  
Stephen William Hutchins ◽  
Fereydoun Layeghi ◽  
Mahmood Bahramizadeh ◽  
...  
Keyword(s):  
Grip Strength ◽  
Clinical Relevance ◽  
Hand Function ◽  
Pinch Strength ◽  
Conservative Approach ◽  
Carpometacarpal Joint ◽  
Custom Made ◽  
First Carpometacarpal Joint ◽  
Thumb Carpometacarpal ◽  
Improved Function

Background and aim: Patients with mild to moderate first carpometacarpal joint osteoarthritis report pain, a reduction in pinch and grip strength and hand function. The purpose of this study was to analyze the effect of a custom-made neoprene thumb carpometacarpal orthosis with thermoplastic stabilization on pain, function, grip strength, and key pinch in these patients. Technique: A total of 11 volunteer patients participated in this study. All the above-mentioned parameters were evaluated at baseline and also 30, 60, and 90 days after using the splint. Discussion: A decrease in pain was observed after 30 days, and this continued to improve during treatment with the splint. After 90 days of using the splint, grip strength was improved. Function and pinch strength also increased significantly and was maintained during the study period compared to baseline. Clinical relevance A custom-made neoprene thumb carpometacarpal orthosis with thermoplastic stabilization may be a suitable conservative approach for the treatment of first carpometacarpal joint osteoarthritis.

scholarly journals Velocity and acceleration level inverse kinematic calculation alternatives for redundant manipulators

Meccanica ◽  
2021 ◽  
Author(s):  
Dóra Patkó ◽  
Ambrus Zelei
Keyword(s):  
Degrees Of Freedom ◽  
Direct Method ◽  
Tracking Error ◽  
Inverse Kinematic ◽  
Linear Feedback ◽  
Joint Position ◽  
Stability Properties ◽  
Acceleration Level ◽  
Error Elimination ◽  
The Stability

AbstractFor both non-redundant and redundant systems, the inverse kinematics (IK) calculation is a fundamental step in the control algorithm of fully actuated serial manipulators. The tool-center-point (TCP) position is given and the joint coordinates are determined by the IK. Depending on the task, robotic manipulators can be kinematically redundant. That is when the desired task possesses lower dimensions than the degrees-of-freedom of a redundant manipulator. The IK calculation can be implemented numerically in several alternative ways not only in case of the redundant but also in the non-redundant case. We study the stability properties and the feasibility of a tracking error feedback and a direct tracking error elimination approach of the numerical implementation of IK calculation both on velocity and acceleration levels. The feedback approach expresses the joint position increment stepwise based on the local velocity or acceleration of the desired TCP trajectory and linear feedback terms. In the direct error elimination concept, the increment of the joint position is directly given by the approximate error between the desired and the realized TCP position, by assuming constant TCP velocity or acceleration. We investigate the possibility of the implementation of the direct method on acceleration level. The investigated IK methods are unified in a framework that utilizes the idea of the auxiliary input. Our closed form results and numerical case study examples show the stability properties, benefits and disadvantages of the assessed IK implementations.

scholarly journals Seeing Beyond Morphology-Standardized Stress MRI to Assess Human Knee Joint Instability

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1035
Author(s):  
Eva-Maria Winkelmeyer ◽  
Justus Schock ◽  
Lena Marie Wollschläger ◽  
Philipp Schad ◽  
Marc Sebastian Huppertz ◽  
...  
Keyword(s):  
Knee Joint ◽  
Imaging Modality ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Anterior Tibial Translation ◽  
Joint Stability ◽  
Anatomic Landmarks ◽  
Human Knee Joint ◽  
Custom Made ◽  
Tibial Translation

While providing the reference imaging modality for joint pathologies, MRI is focused on morphology and static configurations, thereby not fully exploiting the modality’s diagnostic capabilities. This study aimed to assess the diagnostic value of stress MRI combining imaging and loading in differentiating partial versus complete anterior cruciate ligament (ACL)-injury. Ten human cadaveric knee joint specimens were subjected to serial imaging using a 3.0T MRI scanner and a custom-made pressure-controlled loading device. Emulating the anterior-drawer test, joints were imaged before and after arthroscopic partial and complete ACL transection in the unloaded and loaded configurations using morphologic sequences. Following manual segmentations and registration of anatomic landmarks, two 3D vectors were computed between anatomic landmarks and registered coordinates. Loading-induced changes were quantified as vector lengths, angles, and projections on the x-, y-, and z-axis, related to the intact unloaded configuration, and referenced to manual measurements. Vector lengths and projections significantly increased with loading and increasing ACL injury and indicated multidimensional changes. Manual measurements confirmed gradually increasing anterior tibial translation. Beyond imaging of ligament structure and functionality, stress MRI techniques can quantify joint stability to differentiate partial and complete ACL injury and, possibly, compare surgical procedures and monitor treatment outcomes.

scholarly journals Measuring myocardial extracellular volume of the right ventricle in patients with congenital heart disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nadya Al-Wakeel-Marquard ◽  
Tiago Ferreira da Silva ◽  
Sarah Jeuthe ◽  
Sanaz Rastin ◽  
Frédéric Muench ◽  
...  
Keyword(s):  
Congenital Heart Disease ◽  
Heart Disease ◽  
Image Quality ◽  
Right Ventricle ◽  
Wall Thickness ◽  
Congenital Heart ◽  
Extracellular Volume ◽  
Analysis Tool ◽  
Custom Made ◽  
The Right

AbstractThe right ventricle´s (RV) characteristics—thin walls and trabeculation—make it challenging to evaluate extracellular volume (ECV). We aimed to assess the feasibility of RV ECV measurements in congenital heart disease (CHD), and to introduce a novel ECV analysis tool. Patients (n = 39) and healthy controls (n = 17) underwent cardiovascular magnetic resonance T1 mapping in midventricular short axis (SAX) and transverse orientation (TRANS). Regions of interest (ROIs) were evaluated with regard to image quality and maximum RV wall thickness per ROI in pixels. ECV from plane ROIs was compared with values obtained with a custom-made tool that derives the mean T1 values from a “line of interest” (LOI) centered in the RV wall. In CHD, average image quality was good (no artifacts in the RV, good contrast between blood/myocardium), and RV wall thickness was 1–2 pixels. RV ECV was not quantifiable in 4/39 patients due to insufficient contrast or wall thickness < 1 pixel. RV myocardium tended to be more clearly delineated in SAX than TRANS. ECV from ROIs and corresponding LOIs correlated strongly in both directions (SAX/TRANS: r = 0.97/0.87, p < 0.001, respectively). In conclusion, RV ECV can be assessed if image quality allows sufficient distinction between myocardium and blood, and RV wall thickness per ROI is ≥ 1 pixel. T1 maps in SAX are recommended for RV ECV analysis. LOI application simplifies RV ECV measurements.

scholarly journals The training schedule affects the stability, not the magnitude, of the interlimb transfer of learned dynamics

2013 ◽  
Vol 110 (4) ◽  
pp. 984-998 ◽  
Author(s):  
Wilsaan M. Joiner ◽  
Jordan B. Brayanov ◽  
Maurice A. Smith
Keyword(s):  
Short Duration ◽  
Dynamic Environment ◽  
Internal Representation ◽  
Motor Adaptation ◽  
Training Period ◽  
Visually Guided ◽  
Brief Training ◽  
Long Duration ◽  
The Stability ◽  
The Right

The way that a motor adaptation is trained, for example, the manner in which it is introduced or the duration of the training period, can influence its internal representation. However, recent studies examining the gradual versus abrupt introduction of a novel environment have produced conflicting results. Here we examined how these effects determine the effector specificity of motor adaptation during visually guided reaching. After adaptation to velocity-dependent dynamics in the right arm, we estimated the amount of adaptation transferred to the left arm, using error-clamp measurement trials to directly measure changes in learned dynamics. We found that a small but significant amount of generalization to the untrained arm occurs under three different training schedules: a short-duration (15 trials) abrupt presentation, a long-duration (160 trials) abrupt presentation, and a long-duration gradual presentation of the novel dynamic environment. Remarkably, we found essentially no difference between the amount of interlimb generalization when comparing these schedules, with 9–12% transfer of the trained adaptation for all three. However, the duration of training had a pronounced effect on the stability of the interlimb transfer: The transfer elicited from short-duration training decayed rapidly, whereas the transfer from both long-duration training schedules was considerably more persistent (<50% vs. >90% retention over the first 20 trials). These results indicate that the amount of interlimb transfer is similar for gradual versus abrupt training and that interlimb transfer of learned dynamics can occur after even a brief training period but longer training is required for an enduring effect.

Basic Experimental and Numerical Investigations on Chip Pressing

2013 ◽  
Vol 554-557 ◽  
pp. 630-637 ◽  
Author(s):  
Martin Grüner ◽  
Marion Merklein
Keyword(s):  
Numerical Simulation ◽  
Aluminium Alloys ◽  
Testing Machine ◽  
Material Model ◽  
Extrusion Process ◽  
Milling Process ◽  
Numerical Investigations ◽  
Compression Direction ◽  
Universal Testing ◽  
The Stability

Aluminium alloys show a great potential for lightweight constructions due to their high strength and low density but the production of this material is very energy consuming. Also the recycling of aluminium alloys, e.g. chips from the milling process, shows different challenges. Beside contamination by cooling lubricant and oxidation of the surface of the chips the melting and rolling process for new semi finish products needs a high amount of energy. TEKKAYA shows a new approach for recycling of aluminium alloy chips by an extrusion process at elevated temperatures producing different kinds of profiles. A new idea is the production of components directly out of chips using severe plastic deformation for joining of the chips similar to the accumulative roll bonding process in sheet metal forming. In a first approach aluminium alloy chips out of a milling process were uniaxial compressed with different loads inside an axisymmetric tool installed in a universal testing machine. The compressed chip disks subsequently were tested with two experiments to gain information on their stability. First experiment is a disk compression test with the disk standing on its cylindrical surface, giving information on the stability perpendicular to the compression direction. Second experiment is a stacked disk compression test with three disks to investigate the stability parallel to compression direction. During all three tests force and displacement values are recorded by the universal testing machine. These data are also processed to calculate or identify input parameters for the numerical investigations. For numerical simulation ABAQUS in conjunction with the Drucker-Prager-Cap material model, which is often used for sintering processes, seems to be a good choice. By numerical simulation of the experiments and comparison with the experiments input parameters for the material model can be identified showing good accordance. This material model will be used in future numerical investigations of an extrusion process to identify tool geometries leading to high strains inside the material and by this to an increased stability of the parts.

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