Biomechanical Characteristics of Hand Coordination in Grasping Activities of Daily Living

<div><p>Hand coordination can allow humans to have dexterous control with many degrees of freedom to perform various tasks in daily living. An important contributing factor to this important ability is the complex biomechanical architecture of the human hand. However, drawing a clear functional link between biomechanical architecture and hand coordination is challenging. It is not understood which biomechanical characteristics are responsible for hand coordination and what specific effect each biomechanical characteristic has. To explore this link, we first inspected the characteristics of hand coordination during daily tasks through a statistical analysis of the kinematic data, which were collected from thirty right-handed subjects during a multitude of grasping tasks. Then, the functional link between biomechanical architecture and hand coordination was drawn by establishing the clear corresponding causality between the tendinous connective characteristics of the human hand and the coordinated characteristics during daily grasping activities. The explicit functional link indicates that the biomechanical characteristic of tendinous connective architecture between muscles and articulations is the proper design by the Creator to perform a multitude of daily tasks in a comfortable way. The clear link between the structure and the function of the human hand also suggests that the design of a multifunctional robotic hand should be able to better imitate such basic architecture.</p></div

Graphic description of coordinated relationships for joint pairs.

<p>The value of coordination was averaged across subjects and is denoted by the grayscale with pink in each square. The pink color indicates the higher coordination for the corresponding joint pair. The diagram is axisymmetric. Dashed and solid lines passing through squares are used to describe different areas for joint pairs. The joints and abbreviated names are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0146193#pone.0146193.g001" target="_blank">Fig 1</a>.</p

Relationship between the mean movement coordination (MMC) and the numbers of task types.

<p>It shows some representative results from several subjects. Abbreviate: SUBJ, Subject.</p

CyberGlove sensor placement and corresponding kinematic model of human hand.

<p>(A) Placement of 16 sensors used in the CyberGlove (the image is adapted from Ingram 2008, with kind permission from Springer Science + Business Media). (B) Joints and the kinematic model of the human hand. Abbreviations: MCP, metacarpal-phalangeal; PIP, proximal inter-phalangeal; DIP, distal inter-phalangeal; CMC, carpometacarpal; IP, inter-phalangeal; ABD, abduction; T, thumb; I, Index; M, Middle; R, Ring; L, Little; fe, flexion-extension; aa, abduction-adduction.</p

Genetics-directed drug discovery for combating <i>Mycobacterium tuberculosis</i> infection

<p><i>Mycobacterium tuberculosis</i> (Mtb), the pathogen of tuberculosis (TB), is one of the most infectious bacteria in the world. The traditional strategy to combat TB involves targeting the pathogen directly; however, the rapid evolution of drug resistance lessens the efficiency of this anti-TB method. Therefore, in recent years, some researchers have turned to an alternative anti-TB strategy, which hinders Mtb infection through targeting host genes. In this work, using a theoretical genetic analysis, we identified 170 Mtb infection-associated genes from human genetic variations related to Mtb infection. Then, the agents targeting these genes were identified to have high potential as anti-TB drugs. In particular, the agents that can target multiple Mtb infection-associated genes are more druggable than the single-target counterparts. These potential anti-TB agents were further screened by gene expression data derived from connectivity map. As a result, some agents were revealed to have high interest for experimental evaluation. This study not only has important implications for anti-TB drug discovery, but also provides inspirations for streamlining the pipeline of modern drug discovery.</p

Movement-coordinated relationships between joints of the human hand in each type of task.

<p>There are 16×(16–1)/2 = 120 variables of movement-coordinated relationships between every two of the 16 joints recorded in the movement dataset, and they are distributed along the ring circle in the radar chart. Area 1 represents the coordinated relationships regarding the joints of thumb and contains the internal relationships between the joints of the thumb and the external relationships between the joints of thumb and the other four fingers. Similarly, area 2 represents the coordinated relationships regarding o the joints of the index finger excluding the joints of the thumb, and so on. The coordinated relationships between all joints of the ring and little fingers are represented in area 4 of the chart. The amplitudes of the coordinated relationships are averaged across all subjects. The six tasks are chosen to represent the features of all tasks.</p

A Pareto chart for the variance explained by the movement dataset of joint angles.

<p>The bars illustrate the variance explained by each principal component (PC) from the PCA, and the line illustrates the cumulative variance explained by the retaining PCs. Error bars indicate standard deviations across subjects.</p

Additional file 1: Table S1. of Optimal treatment and prognostic factors for esthesioneuroblastoma: retrospective analysis of 187 Chinese patients

Clinical and pathologic features of patients with ENB treated in China. (DOCX 50 kb

Structure-Dependent Membrane-Perturbing Potency of Four Proanthocyanidin Dimers on 3T3-L1 Preadipocytes

Proanthocyanidins (PAs) have been widely recognized for their broad spectrum of beneficial health effects, which are highly structure-dependent. It was found that PA dimers epicatechin-3-gallate-(4β→8,2β→O→7)-epicatechin-3-gallate (A-type ECG dimer) and epigallocatechin-3-gallate-(4β→,2β→O→7)-epigallocatechin-3-gallate (A-type EGCG dimer) inhibit the differentiation of 3T3-L1 cells significantly, whereas epicatechin-(4β→8,2β→O→7)-epicatechin (A-type EC dimer) and epicatechin-(4β→8)-epicatechin (B-type EC dimer) showed little effect in previous work. However, the underlying mechanisms are unclear. To test whether bilayer perturbation may underlie this diversity of actions, we examined the bilayer-modifying effects of the four dimers in both 3T3-L1 cell and 1,2-dipalmitoyl-<i>sn</i>-glycero-3-phosphocholine liposome models by using scanning electron microscopy, fluorescent spectroscopy, differential scanning calorimetry, and molecular dynamics methods. Our results revealed that A-type ECG and EGCG dimers had a high affinity for the lipid bilayer and could form simultaneous hydrogen bonds (H-bond) with both the surface oxygen acceptors and the deeper inside lipid oxygen atoms. However, A-type and B-type EC dimers contacted only the surface oxygen atoms with limited and significantly fewer H-bonds. A-type ECG and EGCG dimers notably distorted the membrane morphology of 3T3-L1 cells. In the present study, we found there was a high positive correlation between the membrane-disturbing abilities of the four dimers and their 3T3-L1 cell differentiation inhibitory effects as previously reported. This indicated that the strong 3T3-L1 cell differentiation inhibitory effect of A-type ECG and EGCG dimers might be due to their strong bilayer-perturbing potency

Additional file 2: Table S2. of Clinicopathologic characteristics and prognostic factors for primary spinal epidural lymphoma: report on 36 Chinese patients and review of the literature

The clinical and pathologic features of Primary spinal epidural lymphomas cases published. (XLSX 20 kb