Anti-L-Dihydroxyphenylalanine monoclonal antibody, clone D101H103

Progressive gait dysfunction is one of the primary motor symptoms in people with Parkinson's disease (PD). It is generally expressed as reduced step length and gait speed and as increased variability in step time and step length. People with PD also exhibit stooped posture which disrupts gait and impedes social interaction. The gait and posture impairments are usually resistant to the pharmacological treatment, worsen as the disease progresses, increase the likelihood of falls, and result in higher rates of hospitalization and mortality. These impairments may be caused by perceptual deficiencies (poor spatial awareness and loss of temporal rhythmicity) due to the disruptions in processing intrinsic information related to movement initiation and execution which can result in misperceptions of the actual effort required to perform a desired movement and maintain a stable posture. Consequently, people with PD often depend on external cues during execution of motor tasks. Numerous studies involving open-loop cues have shown improvements in gait and freezing of gait (FoG) in people with PD. However, the benefits of cueing may be limited, since cues are provided in a consistent/rhythmic manner irrespective of how well a person follows them. This limitation can be addressed by providing feedback in real-time to the user about performance (closed-loop cueing) which may help to improve movement patterns. Some studies that used closed-loop cueing observed improvements in gait and posture in PD, but the treadmill-based setup in a laboratory would not be accessible outside of a research setting, and the skills learned may not readily and completely transfer to overground locomotion in the community. Technologies suitable for cueing outside of laboratory environments could facilitate movement practice during daily activities at home or in the community and could strongly reinforce movement patterns and improve clinical outcomes. This narrative review presents an overview of cueing paradigms that have been utilized to improve gait and posture in people with PD and recommends development of closed-loop wearable systems that can be used at home or in the community to improve gait and posture in PD.

4-aminophenol (4-AP), a typical secondary product from pharmaceuticals preparation, can lead to dangerous collateral effects in drugs. It's crucial to develop suitable methods for fast and accurate determination of 4-AP. Herein, a novel and fast electrochemical method based on flower-like Ag-Au nanocomposites modified electrode has been developed for accurate determination of 4-AP. The flower-like Ag-Au nanocomposites were synthesized via a seed-mediated growth route utilizing L-dopa as reduction agent and assembled by 2-dimension nanosheets. The electrochemical oxidation of 4-AP on Ag-Au nanocomposites modified electrode was studied by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The modified electrode exhibited excellent electrocatalytic activity toward 4-AP. Under the optimized conditions, the sensor displayed high sensitivity for the detection of 4-AP in the linear range from 0.1 to 100 mu M with detection limit of 36 nM (S/N= 3). The fabricated electrode showed high selectivity, good reproducibility, and long-term stability to 4-AP detection. Furthermore, the developed electrochemical sensor showed no interference for simultaneous detection of 4-AP and acetaminophen. It was also demonstrated that the sensor could be applied for the analysis of pharmaceutical products.