25 research outputs found
Biomechanical Risk Assessment of Non-Contact Anterior Cruciate Ligament Injury in Taekwondo Athletes
Non-contact anterior cruciate ligament (ACL) injury can occur in many sports. It is interrelated with gender, anatomy, biomechanics, and neuromuscular control. Taekwondo athletes have a higher incidence of ACL injury than athletes from other sports. Objective: This study aimed to determine the biomechanical gender differences and mechanism of taekwondo athletes with ACL injury. Methods: A total of 28 taekwondo athletes (aged 14â19 years) were randomly selected and grouped by gender. Feet high floor, one foot high floor, and single leg squat were analyzed by a Vicon motion analysis system and Kistler 3D force platform for action. The knee joint angle and ground force were evaluated. Results: Results demonstrated biomechanical differences in knee joint between male and female athletes. Conclusion: ACL injury in taekwondo female athletes indicated the biomechanical mechanism of the knee joint, and it can be prevented by neuromuscular control training
Cyclodextrin-based biological stimuli-responsive carriers for smart and precision medicine
Spurred on by recent progress in nanotechnology and precision medicine, smart drug carriers are entering an entirely new era. Smart drug carriers have been widely studied in recent years as a result of their ability to control drug release under different microenvironments (such as pH, redox, and enzyme) in vivo. Host-guest interactions based on cyclodextrins have proven to be an efficient tool for fabricating smart drug carriers. Because of the application of host-guest interactions, many kinds of biological molecules or supramolecular building blocks can combine into an organic whole at the molecular level. In this review, the features, mechanisms of action, and potent applications of biological stimuli-responsive drug carriers based on cyclodextrins are discussed. In addition, some personal perspectives on this field are presented
Human Streptococcus suis Outbreak, Sichuan, China
Streptococcus suis outbreak was associated with exposure to sick or dead pigs
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Cyclodextrin pendant polymer as an efficient drug carrier for scutellarin
A novel ÎČ-cyclodextrin pendant polymer (Δ-PL-CD), composed of poly(Δ-lysine) (Δ-PL) main chain and glycine-ÎČ-cyclodextrin (Gly-CD) side chains, was prepared by a simple two-step procedure. The Δ-PL-CD was investigated as a drug carrier of hydrophobic drug scutellarin (SCU). The characterization and complexation mode of the SCU:Δ-PL-CD were researched in both solution and solid state by means of photoluminescence spectroscopy, 1H and 2D NMR, X-Ray powder diffraction (XRPD), thermal gravimetric analysis, Particle size and Zeta potential. The solubility test indicated that the solubilizing ability of SCU:Δ-PL-CD was significantly improved compared with SCU:ÎČ-CD and free SCU. Besides, in vitro cell experiment, it was found that SCU:Δ-PL-CD has a strong inhibitory effect on the growth and invasion of tumor cells. The present study provides useful information for Δ-PL-CD as a drug carrier material
BF<sub>3</sub>âPromoted Ring Expansion of Iminylphosphiranes and Acylphosphiranes for Divergent Access to 1,2-Azaphospholidines and 1,2-Dihydrophosphetes
Ring expansion of strained small rings provides an efficient
method
for the synthesis of various high-value carbocycles and heterocycles.
Here we report BF3·Et2O as both an activating
reagent and fluorine source, enabling ring expansion of phosphirane
and PâF bond formation. Treatment of 1-iminylphosphirane complexes
with BF3·Et2O resulted in 1,2-azaphospholidines,
while the reaction of 1-acylphosphirane complexes with BF3·Et2O afforded 1,2-dihydrophosphetes. The reaction
path was tuned by the nucleophilicity of the N and O atoms toward
the intermediate phosphenium cation
Simple Access to Tungsten-Stabilized Disecondary Diphosphines
Transient
terminal phosphinidene complexes [RP-WÂ(CO)<sub>5</sub>] dimerize in
the presence of copper chloride, and the dimers react in situ with
triphenylphosphineâborane to give the disecondary diphosphine
complexes [RPHâPHR]Â[WÂ(CO)<sub>5</sub>]<sub>2</sub>. When R
= CH<sub>2</sub>CH<sub>2</sub>Cl, a cyclization takes place to give
the diphosphirane complex. A 1,2-diphospholane is obtained for R =
Ph by further reaction with 1,3-dibromopropane in the presence of
aqueous K<sub>2</sub>CO<sub>3</sub>
Synthesis and Networking of Spaceborne Deployable Prismatic Antenna Mechanisms Based on Graph Theory
Spaceborne deployable cylindrical antennas have broad application prospects in the fields of space earth observation and remote-sensing detection because of their significant advantages of ultralong aperture, high gain, and flexible beam scanning. As application requirements rapidly develop, a new type of spaceborne deployable cylindrical antenna mechanism with a large diameter and deployability is urgently needed. This paper presents an innovative design for a cylindrical deployable antenna mechanism based on 18R triangular prism elements based on graph theory. The correctness of the configuration is verified by developing a prototype. First, four kinds of nonoverconstrained 12-bar triangular prism-stabilized truss structure configurations and their corresponding topological diagrams are constructed. Second, based on graph theory, three types of 102 triangular prism-stabilized truss mechanism configurations that can be folded into linear mechanisms are derived. Third, the kinematic pair configuration is established to achieve a single-degree-of-freedom 7R2U9S triangular prism deployable unit. Fourth, combined with the geometric topology characteristics of the unit network, a triangular prism unit networking method is proposed, and a cylindrical network mechanism configuration based on 18R triangular prism units is obtained. A prototype was fabricated by 3D printing, and an expansion and retraction function test was conducted, which verified the correctness of the theoretical analysis in this paper. Finally, a new concept configuration for a parabolic cylindrical antenna is proposed. This paper provides a reference for the configuration of large-scale folding truss structures with unit expansion
Prognostic Value and Clinicopathological Features of MicroRNA-206 in Various Cancers: A Meta-Analysis
It has been reported that microRNA-206(miR-206) plays an important role in cancers and could be used as a prognostic biomarker. However, the results are controversial. Therefore, we summarize all available evidence and present a meta-analysis to estimate the prognostic value of miR-206 in various cancers. The relevant studies were collected by searching PubMed, EMBASE, and Web of Science databases until August 21, 2020. Hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were applied to explore the association between miR-206 and survival results and clinicopathologic features. Sources of heterogeneity were investigated by subgroup analysis and sensitivity analysis. Publication bias was evaluated using Eggerâs test. Twenty articles involving 2095 patients were included in the meta-analysis. The pooled HR showed that low miR-206 expression was significantly associated with unfavourable overall survival (OS) (HR=2.03, 95 CI%: 1.53-2.70, P<0.01). In addition, we found that low miR-206 expression predicted significantly negative association with tumor stage (III-IV VS. I-II) (OR=4.20, 95% CI: 2.17-8.13, P<0.01), lymph node status (yes VS. no) (OR=3.58, 95%: 1.51-8.44, P=0.004), distant metastasis (yes VS. no) (OR=3.19, 95%: 1.07-9.50, P=0.038), and invasion depth (T3+T4 vs. T2+T1) (OR=2.43, 95%: 1.70-3.49, P<0.01). miR-206 can be used as an effective prognostic indicator in various cancers. Further investigations are warranted to validate the present results
Reaction of Phospholes with Aldimines: A One-Step Synthesis of Chelating, AlphaâC<sub>2</sub>âBridged Biphospholes
Phospholes
react with aldimines at 170 °C in the presence of mild Lewis
acids to give C<sub>2</sub>-bridged biphospholes in good yields. The
mechanism includes a series of [1,5] shifts of the P-substituents
around the phosphole ring, a PâH + aldimine condensation, and
the formation of a transient three-membered ring that dimerizes