Fabricating porous poly(lactic acid) fibres via electrospinning

© 2018 Elsevier Ltd In this paper, amorphous poly(lactic acid) (PLA), a biodegradable polymer with excellent bio-compatibility, is successfully electrospun into micron-sized fibres with controlled surface and internal morphologies. By careful solvent selection, either surface porosity or internal porosity can be achieved through different mechanisms. Use of chloroform as the solvent gives rise to circular pores of 100 nm diameter confined to the surface. These are obtained in humid conditions by the so-called ‘Breath Figure’ mechanism. It is found that combining chloroform with a water-miscible non-solvent yields either surface porosity (wrinkled effect) using a low boiling point liquid, e.g. ethanol, or internal porosity using a high boiling point liquid, e.g. dimethyl sulphoxide (DMSO). Both these microstructures are obtained through a non-solvent induced phase separation (NIPS) mechanism. Finally, it is found possible to produce both surface and internal porosity using DMSO by a vapour induced phase separation (VIPS) mechanism. The porous electrospun PLA mats were shown to exhibit significantly increased oil absorption capacity compared with the non-porous fibre mats

Electrospinning of polylactic acid fibres containing tea tree and manuka oil

Here the effect of tea tree and manuka essential oils (EOs) on the mechanical properties and antibacterial activity of electrospun polylactic acid (PLA) fibres is investigated. It is found that the essential oils work as plasticisers for PLA, lowering the glass transition temperature of the resulting composite fibres up to 60% and increasing elongation-at-break and tensile strength up to 12 times. Manuka EO is particularly successful in blocking the formation of biofilms of Staphylococcus epidermidis that is typically involved in nosocomial infections associated with implanted devices. The results demonstrate that natural extracts can be used to control the mechanical behaviour of PLA fibres and to confer antibacterial activity

Fabricating porous poly(lactic acid) fibres via electrospinning

© 2018 Elsevier Ltd In this paper, amorphous poly(lactic acid) (PLA), a biodegradable polymer with excellent bio-compatibility, is successfully electrospun into micron-sized fibres with controlled surface and internal morphologies. By careful solvent selection, either surface porosity or internal porosity can be achieved through different mechanisms. Use of chloroform as the solvent gives rise to circular pores of 100 nm diameter confined to the surface. These are obtained in humid conditions by the so-called ‘Breath Figure’ mechanism. It is found that combining chloroform with a water-miscible non-solvent yields either surface porosity (wrinkled effect) using a low boiling point liquid, e.g. ethanol, or internal porosity using a high boiling point liquid, e.g. dimethyl sulphoxide (DMSO). Both these microstructures are obtained through a non-solvent induced phase separation (NIPS) mechanism. Finally, it is found possible to produce both surface and internal porosity using DMSO by a vapour induced phase separation (VIPS) mechanism. The porous electrospun PLA mats were shown to exhibit significantly increased oil absorption capacity compared with the non-porous fibre mats

IMPROVEMENT OF MOTOR COORDINATION SKILLS IN GYMNASTICS ATHLETES

ABSTRACT Introduction The great difficulty and the high risk are inherent marks of artistic gymnastics. It demands motor coordination of large muscle groups. Objective Improve the training of body coordination control in gymnasts. Methods We randomly selected 16 gymnasts as research volunteers, randomly divided into two groups of the same age distribution. After the training period, a new training protocol was implemented, and motor coordination control was analyzed after this intervention. Results There was no significant difference in a one-sided comparative index (P>0.05). There were statistically significant differences in the balance index and the speed index in the fast touch point direction in the athletes (P</div

Reliable Path Planning for Drone Delivery Using a Stochastic Time-Dependent Public Transportation Network

Drones have been regarded as a promising means for future delivery industry by many logistics companies. Several drone-based delivery systems have been proposed but they generally have a drawback in delivering customers locating far from warehouses. This paper proposes an alternative system based on a public transportation network. This system has the merit of enlarging the delivery range. As the public transportation network is actually a stochastic time-dependent network, we focus on the reliable drone path planning problem (RDPP). We present a stochastic model to characterize the path traversal time and develop a label setting algorithm to construct the reliable drone path. Furthermore, we consider the limited battery lifetime of the drone to determine whether a path is feasible, and we account this as a constraint in the optimization model. To accommodate the feasibility, the developed label setting algorithm is extended by adding a simple operation. The complexity of the developed algorithm is analyzed and how it works is demonstrated via a case study

Drone Routing in a Time-Dependent Network: Toward Low-Cost and Large-Range Parcel Delivery

Drones are a promising tool for parcel delivery, since they are cost-efficient and environmentally friendly. However, owing to the limited capacity of the on-board battery, their flight range is constrained. Thus, they cannot deliver some parcels if the customers are too far from the depot. To address this issue, this article proposes a novel method, in which a parcel delivery drone can 'take' a public transportation vehicle and travel on its roof. The problem under consideration is how to make use of the public transportation network to route the drone between the depot and the customer. Compared to the currently available methods that use drones, the most important merit of this approach is a significant expansion of the delivery area. We construct a multimodal network consisting of public transportation vehicles' trips and drone flights. Because of the complexity of this multimodal network, we convert it to a simple network with a set of simple procedures. In the extended network, we formulate the shortest drone path problem that minimizes the return instant to the depot, subject to that the drone energy consumption on this path is no greater than the initial energy. We present a Dijkstra-based method to find the shortest drone path. Moreover, we extend the proposed method to the case with uncertainty, because the public transportation vehicles cannot exactly follow their timetables in practice. Simulation results are presented to demonstrate how the method works

Image_2_Efficacy of photodynamic therapy in the treatment of port wine stains: A systematic review and meta-analysis.TIF

BackgroundPort wine stains (PWS) often cause cosmetic effects and psychological distress. Pulsed dye lasers (PDL) and photodynamic therapy (PDT) are the most commonly used treatments. PDL is still the “gold standard” of therapy to date. However, its shortcomings have become apparent as clinical applications have increased. PDT has been proven as an alternative to PDL. Patients with PWS still lack enough evidence about PDT to make informed treatment decisions.ObjectiveThe purpose of this systematic review and meta-analysis was to assess the safety and effectiveness of PDT for PWS.MethodsThe online datasets, comprising PubMed, Embase, Web of Science, and the Cochrane Library, were searched for meta-analysis-relevant publications. Two reviewers separately evaluated the risk of bias in each listed study. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the treatment and safety outcomes.ResultsOur search retrieved 740 hits and only 26 studies were finally included. Among the 26 studies included, 3 were randomized clinical trials, and 23 were prospective or retrospective cohort investigations. Based on a gathered assessment, the percentage of individuals achieving a 60% improvement was estimated to be 51.5% [95% confidence interval (CI): 38.7–64.1; I2 = 83.8%] and a ≥75% improvement was 20.5% (95% CI: 14.5–26.5; I2 = 78.2%) after 1–8.2 treatment sessions (GRADE score: very low). Due to the statistical diversity of the meta-analysis, a subgroup assessment was performed to determine the sources of diversity. The collected findings indicated that the impact of PDT on enhancing the medical effectiveness of PWS was significant in different treatment sessions, different types of ages, different locations of PWS, and different types of PWS. Pain and edema occurred in most patients. Hyperpigmentation was present in 7.9–34.1% of the patients in 17 studies. Photosensitive dermatitis, hypopigmentation, blister, and scar were infrequently reported, with 0–5.8% incidences.ConclusionPhotodynamic therapy is recommended as a safe and effective treatment for PWS based on the current evidence. However, our findings are based on poor-quality evidence. Therefore, comparative investigations of a large scale and high quality are necessary to support this conclusion.</p

Image_1_Efficacy of photodynamic therapy in the treatment of port wine stains: A systematic review and meta-analysis.TIF

BackgroundPort wine stains (PWS) often cause cosmetic effects and psychological distress. Pulsed dye lasers (PDL) and photodynamic therapy (PDT) are the most commonly used treatments. PDL is still the “gold standard” of therapy to date. However, its shortcomings have become apparent as clinical applications have increased. PDT has been proven as an alternative to PDL. Patients with PWS still lack enough evidence about PDT to make informed treatment decisions.ObjectiveThe purpose of this systematic review and meta-analysis was to assess the safety and effectiveness of PDT for PWS.MethodsThe online datasets, comprising PubMed, Embase, Web of Science, and the Cochrane Library, were searched for meta-analysis-relevant publications. Two reviewers separately evaluated the risk of bias in each listed study. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the treatment and safety outcomes.ResultsOur search retrieved 740 hits and only 26 studies were finally included. Among the 26 studies included, 3 were randomized clinical trials, and 23 were prospective or retrospective cohort investigations. Based on a gathered assessment, the percentage of individuals achieving a 60% improvement was estimated to be 51.5% [95% confidence interval (CI): 38.7–64.1; I2 = 83.8%] and a ≥75% improvement was 20.5% (95% CI: 14.5–26.5; I2 = 78.2%) after 1–8.2 treatment sessions (GRADE score: very low). Due to the statistical diversity of the meta-analysis, a subgroup assessment was performed to determine the sources of diversity. The collected findings indicated that the impact of PDT on enhancing the medical effectiveness of PWS was significant in different treatment sessions, different types of ages, different locations of PWS, and different types of PWS. Pain and edema occurred in most patients. Hyperpigmentation was present in 7.9–34.1% of the patients in 17 studies. Photosensitive dermatitis, hypopigmentation, blister, and scar were infrequently reported, with 0–5.8% incidences.ConclusionPhotodynamic therapy is recommended as a safe and effective treatment for PWS based on the current evidence. However, our findings are based on poor-quality evidence. Therefore, comparative investigations of a large scale and high quality are necessary to support this conclusion.</p

Table_1_Efficacy of photodynamic therapy in the treatment of port wine stains: A systematic review and meta-analysis.XLSX

BackgroundPort wine stains (PWS) often cause cosmetic effects and psychological distress. Pulsed dye lasers (PDL) and photodynamic therapy (PDT) are the most commonly used treatments. PDL is still the “gold standard” of therapy to date. However, its shortcomings have become apparent as clinical applications have increased. PDT has been proven as an alternative to PDL. Patients with PWS still lack enough evidence about PDT to make informed treatment decisions.ObjectiveThe purpose of this systematic review and meta-analysis was to assess the safety and effectiveness of PDT for PWS.MethodsThe online datasets, comprising PubMed, Embase, Web of Science, and the Cochrane Library, were searched for meta-analysis-relevant publications. Two reviewers separately evaluated the risk of bias in each listed study. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the treatment and safety outcomes.ResultsOur search retrieved 740 hits and only 26 studies were finally included. Among the 26 studies included, 3 were randomized clinical trials, and 23 were prospective or retrospective cohort investigations. Based on a gathered assessment, the percentage of individuals achieving a 60% improvement was estimated to be 51.5% [95% confidence interval (CI): 38.7–64.1; I2 = 83.8%] and a ≥75% improvement was 20.5% (95% CI: 14.5–26.5; I2 = 78.2%) after 1–8.2 treatment sessions (GRADE score: very low). Due to the statistical diversity of the meta-analysis, a subgroup assessment was performed to determine the sources of diversity. The collected findings indicated that the impact of PDT on enhancing the medical effectiveness of PWS was significant in different treatment sessions, different types of ages, different locations of PWS, and different types of PWS. Pain and edema occurred in most patients. Hyperpigmentation was present in 7.9–34.1% of the patients in 17 studies. Photosensitive dermatitis, hypopigmentation, blister, and scar were infrequently reported, with 0–5.8% incidences.ConclusionPhotodynamic therapy is recommended as a safe and effective treatment for PWS based on the current evidence. However, our findings are based on poor-quality evidence. Therefore, comparative investigations of a large scale and high quality are necessary to support this conclusion.</p

Clustering High-Dimensional Landmark-Based Two-Dimensional Shape Data

<div><p>An important goal in image analysis is to cluster and recognize objects of interest according to the shapes of their boundaries. Clustering such objects faces at least four major challenges including a curved shape space, a high-dimensional feature space, a complex spatial correlation structure, and shape variation associated with some covariates (e.g., age or gender). The aim of this article is to develop a penalized model-based clustering framework to cluster landmark-based planar shape data, while explicitly addressing these challenges. Specifically, a mixture of offset-normal shape factor analyzers (MOSFA) is proposed with mixing proportions defined through a regression model (e.g., logistic) and an offset-normal shape distribution in each component for data in the curved shape space. A latent factor analysis model is introduced to explicitly model the complex spatial correlation. A penalized likelihood approach with both adaptive pairwise fused Lasso penalty function and <i>L</i>₂ penalty function is used to automatically realize variable selection via thresholding and deliver a sparse solution. Our real data analysis has confirmed the excellent finite-sample performance of MOSFA in revealing meaningful clusters in the corpus callosum shape data obtained from the Attention Deficit Hyperactivity Disorder-200 (ADHD-200) study. Supplementary materials for this article are available online.</p></div