Experimental Demonstration of the Lower Leg Trajectory Error Framework Using Physiological Data as Inputs.

While many studies have attempted to characterize the mechanical behavior of passive prosthetic feet to understand their influence on amputee gait, the relationship between mechanical design and biomechanical performance has not yet been fully articulated from a fundamental physics perspective. A novel framework, called lower leg trajectory error (LLTE) framework, presents a means of quantitatively optimizing the constitutive model of prosthetic feet to match a reference kinematic and kinetic dataset. This framework can be used to predict the required stiffness and geometry of a prosthesis to yield a desired biomechanical response.

A lower threshold for revision of aseptic unicompartmental vs total knee arthroplasty.

Aims: It has been hypothesized that a unicompartmental knee arthroplasty (UKA) is more likely to be revised than a total knee arthroplasty (TKA) because conversion surgery to a primary TKA is a less complicated procedure. The purpose of this study was to determine if there is a lower threshold for revising a UKA compared with TKA based on Oxford Knee Scores (OKSs) and range of movement (ROM) at the time of revision.

Methods: We retrospectively reviewed 619 aseptic revision cases performed between December 1998 and October 2018.

Quantification of rectifications for the Northwestern University Flexible Sub-Ischial Vacuum Socket.

Background: The fit and function of a prosthetic socket depend on the prosthetist's ability to design the socket's shape to distribute load comfortably over the residual limb. We recently developed a sub-ischial socket for persons with transfemoral amputation: the Northwestern University Flexible Sub-Ischial Vacuum Socket.

Objective: This study aimed to quantify the rectifications required to fit the Northwestern University Flexible Sub-Ischial Vacuum Socket to teach the technique to prosthetists as well as provide a computer-aided design-computer-aided manufacturing option.

Interrater reliability of mechanical tests for functional classification of transtibial prosthesis components distal to the socket.

Substantial evidence suggests that the design and associated mechanical function of lower-limb prostheses affects user health and mobility, supporting common standards of clinical practice for appropriate matching of prosthesis design and user needs. This matching process is dependent on accurate and reliable methods for the functional classification of prosthetic components. The American Orthotic & Prosthetic Association developed a set of tests for L-code characterization of prosthesis mechanical properties to facilitate functional classification of passive below-knee prosthetic components.

Using a three-dimensional model of the Ankle-Foot Orthosis/leg to explore the effects of combinations of axis misalignments.

Background And Aim: Misaligning the mechanical axes of Ankle-Foot Orthoses with the ankle axis may lead to tissue damage, reduced gait efficiency, and mechanical wear on the orthosis. Previous models developed to describe the consequences of joint misalignments have only been applied to the sagittal plane. In this study, a previously developed three-dimensional model of the Ankle-Foot Orthosis/leg system was used to determine the effects of misalignments in the frontal and transverse planes and how they interact with misalignments in the sagittal plane.

A three-dimensional model to assess the effect of ankle joint axis misalignments in ankle-foot orthoses.

Background: Misalignment of an articulated ankle-foot orthosis joint axis with the anatomic joint axis may lead to discomfort, alterations in gait, and tissue damage. Theoretical, two-dimensional models describe the consequences of misalignments, but cannot capture the three-dimensional behavior of ankle-foot orthosis use.

Objectives: The purpose of this project was to develop a model to describe the effects of ankle-foot orthosis ankle joint misalignment in three dimensions.

Modeling effects of sagittal-plane hip joint stiffness on reciprocating gait orthosis-assisted gait.

Upright ambulation is believed to improve quality of life for persons with lower-limb paralysis (LLP). However, ambulatory orthoses for persons with LLP, like reciprocating gait orthoses (RGOs), result in a slow, exhausting gait. Increasing the hip joint stiffness of these devices may improve the efficiency of RGO-assisted gait.

A new methodology for atrial flutter ablation by direct visualization of cavotricuspid conduction with voltage gradient mapping: a comparison to standard techniques.

Aims: To demonstrate that critical conduction within the cavotricuspid isthmus (CTI) can be directly visualized by voltage gradient mapping and facilitate efficient ablation compared to standard techniques.

Methods And Results: Group 1 (1 operator, n = 11) ablated based upon contact voltage measurements and voltage gradient mapping. Ablation targeted low-voltage bridges (LVBs) within the CTI.

Effects of raw material and rotational speed on the cyclic fatigue of ProFile Vortex rotary instruments.

Introduction: This in vitro study compared the cyclic fatigue resistance of ProFile Vortex rotary instruments (DENTSPLY Tulsa Dental, Tulsa, OK) made of two different raw materials: M-Wire and regular superelastic wire (SE-wire) at two different rotational speeds. Two rotary-based Profile Vortex instruments with taper 0.04 and 0.

Radiation risks from exposure to chest computed tomography.

Since 1972, when the first clinical computed tomography (CT) scanner was installed, amazing advances in CT technology have spurned its rapid growth and increasing utilization. Although CT scans are often performed for clinically valid indications that enable proper medical decision-making, the introduction of some protocols has outpaced the scientific data supporting their appropriateness. Considering the growing volume of CT scans performed and the appurtenant risks of radiation exposure, any exposure of patients to radiation for unnecessary or undocumented indications is worrisome.

Walking mechanics of persons who use reciprocating gait orthoses.

Although ambulation with a reciprocating gait orthosis (RGO) may provide physical benefits to people with lower-limb paralysis, the high metabolic energy cost associated with ambulation limits orthosis use. The purpose of this case series was to investigate the dynamics of ambulation with RGOs to identify and better understand the potential causes of the high energy cost. Data were acquired from five regular users of RGOs.

Transcriptional repression of WEE1 by Kruppel-like factor 2 is involved in DNA damage-induced apoptosis.

Human Kruppel-like factor 2 (KLF2) is a Cys(2)/His(2) zinc-finger-containing transcriptional factor, which is involved in multiple cellular pathways. Utilizing gene expression profiling to identify aberrantly expressed genes in ovarian cancer, we found that KLF2 was significantly and specifically downregulated in ovarian tumors. After reintroducing KLF2 into ovarian cancer cell lines, we observed decreased cell growth and increased sensitivity to DNA damage-induced apoptosis.

A new solution for the removal of the smear layer.

Various organic acids, ultrasonic instruments, and lasers have been used to remove the smear layer from the surface of instrumented root canals. The purpose of this study was to investigate the effect of a mixture of a tetracycline isomer, an acid, and a detergent (MTAD) as a final rinse on the surface of instrumented root canals. Forty-eight extracted maxillary and mandibular single-rooted human teeth were prepared by using a combination of passive step-back and rotary 0.

Zero-resistance states induced by electromagnetic-wave excitation in GaAs/AlGaAs heterostructures.

The observation of vanishing electrical resistance in condensed matter has led to the discovery of new phenomena such as, for example, superconductivity, where a zero-resistance state can be detected in a metal below a transition temperature T(c) (ref. 1). More recently, quantum Hall effects were discovered from investigations of zero-resistance states at low temperatures and high magnetic fields in two-dimensional electron systems (2DESs).