Twenty-four-hour blood pressure trajectories and clinical outcomes in patients who had an acute ischaemic stroke.

OBJECTIVE: The management of blood pressure (BP) in acute ischaemic stroke remains a subject of controversy. This investigation aimed to explore the relationship between 24-hour BP patterns following ischaemic stroke and clinical outcomes. METHODS: A cohort of 4069 patients who had an acute ischaemic stroke from 26 hospitals was examined. Five systolic BP trajectories were identified by using latent mixture modelling: trajectory category 5 (190-170 mm Hg), trajectory category 4 (180-140 mm Hg), trajectory category 3 (170-160 mm Hg), trajectory category 2 (155-145 mm Hg) and trajectory category 1 (150-130 mm Hg). The primary outcome was a composite outcome of death and major disability at 3 months poststroke. RESULTS: Patients with trajectory category 5 exhibited the highest risk, while those with trajectory category 1 had the lowest risk of adverse outcomes at 3-month follow-up. Compared with the patients in the trajectory category 5, adjusted ORs (95% CIs) for the primary outcome were 0.79 (0.58 to 1.10), 0.70 (0.53 to 0.93), 0.64 (0.47 to 0.86) and 0.47 (0.33 to 0.66) among patients in trajectory category 4, trajectory category 3, trajectory category 2 and trajectory category 1, respectively. Similar trends were observed for death, vascular events and the composite outcome of death and vascular events. CONCLUSION: Patients with persistently high BP at 180 mm Hg within 24 hours of ischaemic stroke onset had the highest risk, while those maintaining stable BP at a moderate-low level (150 mm Hg) or even a low level (137 mm Hg) had more favourable outcomes.

Nanofibers with homogeneous heparin distribution and protracted release profile for vascular tissue engineering.

In clinic, controlling acute coagulation after small-diameter vessel grafts transplantation is considered a primary problem. The combination of heparin with high anticoagulant efficiency and polyurethane fiber with good compliance is a good choice for vascular materials. However, blending water-soluble heparin with fat-soluble poly (ester-ether-urethane) urea elastomer (PEEUU) uniformly and preparing nanofibers tubular grafts with uniform morphology is a huge challenge. In this research, we have compounded PEEUU with optimized constant concentration of heparin by homogeneous emulsion blending, then spun into the hybrid PEEUU/heparin nanofibers tubular graft (H-PHNF) for replacing rats' abdominal aorta in situ for comprehensive performance evaluation. The in vitro results demonstrated that H-PHNF was of uniform microstructure, moderate wettability, matched mechanical properties, reliable cytocompatibility, and strongest ability to promote endothelial growth. Replacement of resected abdominal artery with the H-PHNF in rat showed that the graft was capable of homogeneous hybrid heparin and significantly promoted the stabilization of vascular smooth muscle cells (VSMCs) as well as stabilizing the blood microenvironment. This research demonstrates the H-PHNF with substantial patency, indicating their potential for vascular tissue engineering.

Kinetically Controlled Star Copolymer Self-Assembly for Rapid Fabrication of Nanoparticles with High Encapsulation Capacity.

Rapid and scalable self-assembly of an amphiphilic 21-arm star copolymer, (polystyrene-block-polyethylene glycol)21 [(PS-b-PEG)21 ] in aqueous solution has been performed by reverse solvent exchange procedure. Transmission electron microscope (TEM) and nanoparticle tracking analysis (NTA) reveal the formation of nanoparticles with narrow size distribution. Further investigation indicates a kinetically controlled self-assembly mechanism of the copolymers, in which the star topology of the amphiphilic copolymer and deep quenching condition by reverse solvent exchange are key to accelerate intrachain contraction of the copolymer during phase separation. When interchain contraction dominant over interchain association, nanoparticles with low aggregation number could be formed. Thanks to the high hydrophobic contents of the (PS-b-PEG)21 polymers, the resulted nanoparticles could encapsulate a high capacity of hydrophobic cargo up to 19.84 %. The kinetically controlled star copolymer self-assembly process reported here provides a platform for the rapid and scalable fabrication of nanoparticle with high drug loading capacity (LC), which may find broad range of applications in, for example drug delivery, nanopesticide.

Poisoning by Purity: What Stops Stereocomplex Crystallization in Polylactide Racemate?

Formation of stereocomplex crystals (SC) is an effective way to improve the heat resistance and mechanical performance of poly(lactic acid) products. However, at all but the slowest cooling rates, SC crystallization of a high-molecular-weight poly(l-lactic acid)/poly(d-lactic acid) (PLLA/PDLA) racemate stops at a high temperature or does not even start, leaving the remaining melt to crystallize into homochiral crystals (HC) or an SC-HC mixture on continuous cooling. To understand this intriguing phenomenon, we revisit the SC crystallization of both high- and low-molecular-weight PLLA/PDLA racemates. Based on differential scanning calorimetry (DSC), supplemented by optical microscopy and X-ray scattering, we concluded that what stops the growth of SC is the accumulation of the nearly pure enantiomer, either PDLA or PLLA, that is rejected from the SC ahead of its growth front. The excess enantiomer is a result of random compositional fluctuation present in the melt even if the average composition is 1:1. The situation is more favorable if the initial polymer is not fully molten or is brought up to just above the melting point where SC seeds remain, as proven by DSC and X-ray scattering. Moreover, we find that not only is SC growth poisoned by the locally pure enantiomer but also that at lower temperatures, the HC growth can be poisoned by the blend. This explains why SC growth, arrested at high temperatures, can resume at lower temperatures, along with the growth of HC. Furthermore, while some previous works attributed the incomplete SC crystallization to a problem of primary nucleation, we find that adding a specific SC-promoting nucleating agent does not help alleviate the problem of cessation of SC crystallization. This reinforces the conclusion that the main problem is in growth rather than in nucleation.

Multicompartment Nanoparticles by Crystallization-Driven Self-Assembly of Star Polymers: Combining High Stability and Loading Capacity.

Herein novel multicompartment nanoparticles (MCNs) that combine high stability and cargo loading capacity are developed. The MCNs are fabricated by crystallization-driven self-assembly (CDSA) of a tailor-made 21 arm star polymer, poly(L-lactide)[poly(tert-butyl acrylate)-block-poly(ethylene glycol)]20 [PLLA(PtBA-b-PEG)20 ]. Platelet-like or spherical MCNs containing a crystalline PLLA core and hydrophobic PtBA subdomains are formed and stabilized by PEG. Hydrophobic cargos, such as Nile Red and chemotherapeutic drug doxorubicin, can be successfully encapsulated into the collapsed PtBA subdomains with loading capacity two orders of magnitude higher than traditional CDSA nanoparticles. Depolarized fluorescence measurements of the Nile Red loaded MCNs suggest that the free volume of the hydrophobic chains in the nanoparticles may be the key for regulating their drug loading capacity. In vitro study of the MCNs suggests excellent cytocompatibility of the blank nanoparticles as well as a dose-dependent cellular uptake and cytotoxicity of the drug-loaded MCNs.

Electrospun PCL/collagen hybrid nanofibrous tubular graft based on post-network bond processing for vascular substitute.

Inhibiting thrombus formation and intimal hyperplasia is essential for orthotopic tissue-engineered vascular grafts. The matching mechanical properties of autologous blood vessels and inhibition of platelet aggregation are considered as two points to improve the success rate of transplantation. The poly(ε-caprolactone)/collagen/heparin composite vascular graft (PCLHC) with three-dimensional network structure were constructed by electrospinning, which can mimic natural vascular biomechanics and enhance the viability of cells viability in vitro. The hybrid collagen matrix network nanofibers formed by electrospinning exhibited uniform and smooth morphology. The results of mechanical experiments showed that PCLHC had similar mechanical properties to natural blood vessels. And the addition of heparin enhanced the anticoagulation of PCLHC. Simultaneous three-component hybrid nanofibers showed a potentially reliable ability to promote the proliferation of human umbilical vein endothelial cells (HUVECs). In summary, all the results showed that the three-dimensional network structure of PCLHC presented the potential to heal injured vessels.

An Intelligent Nanovehicle Armed with Multifunctional Navigation for Precise Delivery of Toll-Like Receptor 7/8 Agonist and Immunogenic Cell Death Amplifiers to Eliminate Solid Tumors and Trigger Durable Antitumor Immunity.

Cancer immunotherapy is revolutionary in oncology and hematology. However, a low response rate restricts the clinical benefits of this therapy owing to inadequate T lymphocyte infiltration and low delivery efficiency of immunotherapeutic drugs. Herein, an intelligent nanovehicle (folic acid (FA)/1-(4-(aminomethyl) benzyl)-2-butyl-1H-imidazo[4,5-c]quinolin-4-amine (IMDQ)-oxaliplatin (F/IMO)@CuS) armed with multifunctional navigation is designed for the accurate delivery of cargoes to tumor cells and dendritic cells (DCs), respectively. The nanovehicle is based on a near infrared-responsive inorganic CuS nanoparticles, acting as a photosensitizer and carrier of the chemotherapeutic agent oxaliplatin, and enters tumor cells owing to the presence of folic acid on the surface of CuS upon intratumoral injection. Furthermore, a toll-like receptor (TLR) 7/8 agonist-conjugated polymer, anchored on the surface of CuS, is modified with mannose to bind with DCs in the tumor microenvironment. Upon exposure to laser irradiation, nanovehicles disassemble, releasing oxaliplatin, to ablate tumor cells and amplify immunogenic cell death in combination with photothermal therapy. Mannose-modified polymer-TLR7/8 agonist conjugates are subsequently exposed, leading to the activation of DCs and proliferation of T cells. Collectively, these intelligent nanovehicles reduce tumor burden, exert a robust antitumor immune response, and generate long-term immune protection to prevent tumor recurrence.

Asymmetric Incorporation of Silver Nanoparticles in Polymeric Assemblies by Coassembly of Tadpole-Like Nanoparticles and Amphiphilic Block Copolymers.

A general approach to asymmetrically localize nanoparticles (NPs) in larger polymeric nanostructures is demonstrated by coassembly of tadpole-like silver NPs (AgNPs) and amphiphilic block copolymers (BCPs). The tadpole-like AgNPs are prepared by template synthesis using a tailor-made A(BC)20 star polymer, namely poly(ethylene glycol)[poly(acrylic acid)-block-polystyrene]20 [PEG(PAA-b-PS)20 ], as template resulting in AgNPs decorated with twenty short PS chains and one long PEG chain, named Ag@PEG(PS)20 . The asymmetric distribution of these AgNPs in various polymeric nanostructures, e.g., spherical micelles, cylindrical micelles, vesicles, and sponge phase, is achieved via coassembly of the as-prepared Ag@PEG(PS)20 and PEG-b-PS in solution driven by the anisotropic nature of the Ag@PEG(PS)20 . This report not only provides a new strategy for the fabrication of tadpole-like NPs but also offers opportunity for off-center distributing NPs in hybrid assemblies, which may find applications in, e.g., sensing, catalysis, and diagnostics.

Polyzwitterions with LCST Side Chains: Tunable Self-Assembly.

Manipulation of self-assembly behavior of copolymers via environmental change is attractive in the fabrication of smart polymeric materials. We present tunable self-assembly behavior of graft copolymers, poly(sulfobetaine methacrylate)-graft-poly[oligo(ethylene glycol) methyl ether methacrylate)-co-di(ethylene glycol) methyl ether methacrylate] (PSBM-g-P(OEGMA-co-DEGMA)). Upon heating the aqueous solutions, the graft copolymers undergo a transition from micelles with PSBM cores to unimers (i.e., individual macromolecules) and then to reversed micelles with P(OEGMA-co-DEGMA) cores, thus demonstrating the tunability of the self-assembling through temperature change. In the presence of salt the temperature response of PSBM is eliminated, and the structure of the micelles with the P(OEGMA-co-DEGMA) core changes. Moreover, for the graft copolymer with long side chains, micelles with aggregation number ∼ 2 were formed with a PSBM core at low temperature, which is ascribed to the steric effect of the P(OEGMA-co-DEGMA) shell.

Relationship between cognitive flexible, depression and eating attitude in middle school students / 中国学校卫生

Objective@#To explore the relationship among cognitive flexibility, depression and eating attitude of adolescents and the influencing factors of eating attitude.@*Methods@#A total of 1 231 subjects were assessed using general information questionnaire, Kutcher Adolescent Depression Scale 11 item(KADS-11), Cognitive Flexibility Inventory(CFI), Eating Attitude Test 26(EAT-26). Data were analyzed by independent sample t-test, univariate linear regression, spearman correlation analysis and Logistic regression.@*Results@#There were significant differences in EAT 26 among adolescents between genders and between those with or without depression(P<0.01). Statistically significant differences were observed in CFI, flexible control and KADS 11 among adolescents with or without eating disorders(P<0.01). The scores of EAT 26 was negatively correlated with CFI (r=-0.19, P<0.01) and flexible control(r=-0.23, P<0.01). And there was a significant positive correlation between EAT 26 and KADS 11(r=0.23, P<0.01). Female(OR=2.40, 95%CI=1.87-3.23), depression (OR=1.76, 95%CI=1.35-2.29) and poor flexible control (OR=1.94, 95%CI=1.48-2.54) were risk factors for eating disorders.@*Conclusion@#Female, individuals with depressive symptoms or with poor flexible control ability are more likely to have eating disorders which need more attention.

Photodynamic Antifungal Activity of Hypocrellin A Against Candida albicans.

Many studies have reported that hypocrellin A (HA) exhibits effective antimicrobial activities with proper irradiation. However, its antifungal activity and the involved mechanism have not been fully defined. In this study, HA-mediated cytotoxicity in Candida albicans cells was evaluated after antimicrobial photodynamic therapy (aPDT). The results showed that 1.0 µg/ml HA significantly decreased the survival rate of C. albicans cells with light illumination. Moreover, the ROS levels were also remarkably elevated by HA. Further study found that HA combined with illumination led to cell membrane potential depolarization and cell membrane integrity damage. To investigate the form of cell death, a series of apoptosis-related parameters, including mitochondrial transmembrane potential, metacaspase activity, DNA fragmentation, nuclear condensation, and cytosolic and mitochondrial calcium, were analyzed. Data showed that all the above mentioned apoptosis hallmarks were affected after treatment with HA, indicating that HA induced C. albicans cell apoptosis. Finally, HA-mediated aPDT was demonstrated to be low-toxic and effective in treating cutaneous C. albicans infections. This study highlights the antifungal effect and mechanism of HA-mediated aPDT against C. albicans and provides a promising photodynamic antifungal candidate for C. albicans skin infections.

Electrospun frogspawn structured membrane for gravity-driven oil-water separation.

The aim of this study is to prepare a fibrous membrane scaffold that possesses a frogspawn structure for high-efficiency oil-water separation. Polyamic acid was first electrospun onto a rotating wheel-collector to obtain the fibrous membrane. Subsequently, post-processing by immersion in a polydimethylsiloxane solution and a silica nanoparticles suspension, followed by a thermal treatment generated a frogspawn-structured fibrous membrane. The obtained membrane achieved superhydrophobicity and superoleophilicity, with the water contact angle as high as 155.75° and the oil contact angle lower than 10°. The separation efficiencies of the membrane were higher than 99.55% and the permeate flux was maintained at greater than 4400 L/m2∙h after 20 separation cycles. Additionally, the wettability studies suggested the membrane exhibits high stability because it can resist damages due to high temperature (150 °C), acid/basic conditions and organic/inorganic solvents. These findings indicated that this composite membrane has great potential for use in gravity-driven oil-water separation and can extend the range of its application for treatments of oil spills incident, oily wastewater and spent liquor.

Stimuli-responsive bio-based polymeric systems and their applications.

Stimuli-responsive bio-based polymeric systems are gaining considerable attention as intelligent versatile tools that show great potential in various fields. In this review, an overview is given of recent developments of stimuli-responsive bio-based polymeric systems. The characteristics of bio-based polymers in different applications are discussed and the superiority of these advanced stimuli-responsive bio-based polymeric systems is highlighted. Furthermore, several emerging applications of these systems including intelligent drug delivery, responsive food packaging and smart water treatment are discussed and the section of intelligent drug delivery is emphasized in detail. Finally, the respective prospects and limitations inherent to these systems are addressed.

Durable superhydrophobic and superoleophilic electrospun nanofibrous membrane for oil-water emulsion separation.

Marinepollution andindustrial wastewater have caused serious environmental pollution, thereby resulting into an alarming damage to public health in the past decades, hence the high demand for, cost effective, energy-efficient oil-water separation technologies for the removal of oil contaminants from such water. Herein, we report a facile method to fabricate superhydrophobic/superoleophilic membrane by immersing a polyimide (PI)-based nanofibrous membrane into a water/ethanol/ammonia/dopamine mixture, followed by modification with 1H, 1H, 2H, 2H-perfluorodecanethiol (PFDT). The PI-based membrane exhibited water contact angle (WCA) above 153°, while the oil contact angle (OCA) approached 0°, thereby promoting an outstanding chemical stability which sustained its superhydrophobicity when immersed in aqueous solutions at different pH values. Additionally, the PI-based membrane possesses ultrahigh flux, high separation efficiency and good reusability in oil-water separation. The aforementioned properties, as well as the easily scale-up preparation process ensure that this promising as-fabricated membrane can be applied for practical environmental applications including treatment of oily wastewater and oil spillage clean-up.

Light-Driven Au-WO3@C Janus Micromotors for Rapid Photodegradation of Dye Pollutants.

A novel light-driven Au-WO3@C Janus micromotor based on colloidal carbon WO3 nanoparticle composite spheres (WO3@C) prepared by one-step hydrothermal treatment is described. The Janus micromotors can move in aqueous media at a speed of 16 µm/s under 40 mW/cm2 UV light due to diffusiophoretic effects. The propulsion of such Au-WO3@C Janus micromotors (diameter ∼ 1.0 µm) can be generated by UV light in pure water without any external chemical fuels and readily modulated by light intensity. After depositing a paramagnetic Ni layer between the Au layer and WO3, the motion direction of the micromotor can be precisely controlled by an external magnetic field. Such magnetic micromotors not only facilitate recycling of motors but also promise more possibility of practical applications in the future. Moreover, the Au-WO3@C Janus micromotors show high sensitivity toward extremely low concentrations of sodium-2,6-dichloroindophenol (DCIP) and Rhodamine B (RhB). The moving speed of motors can be significantly accelerated to 26 and 29 µm/s in 5 × 10-4 wt % DCIP and 5 × 10-7 wt % RhB aqueous solutions, respectively, due to the enhanced diffusiophoretic effect, which results from the rapid photocatalytic degradation of DCIP and RhB by WO3. This photocatalytic acceleration of the Au-WO3@C Janus micromotors confirms the self-diffusiophoretic mechanism and opens an opportunity to tune the motility of the motors. This work also offers the light-driven micromotors a considerable potential for detection and rapid photodegradation of dye pollutants in water.

Dye-Enhanced Self-Electrophoretic Propulsion of Light-Driven TiO2-Au Janus Micromotors.

Light-driven synthetic micro-/nanomotors have attracted considerable attention in recent years due to their unique performances and potential applications. We herein demonstrate the dye-enhanced self-electrophoretic propulsion of light-driven TiO2-Au Janus micromotors in aqueous dye solutions. Compared to the velocities of these micromotors in pure water, 1.7, 1.5, and 1.4 times accelerated motions were observed for them in aqueous solutions of methyl blue (10-5 g L-1), cresol red (10-4 g L-1), and methyl orange (10-4 g L-1), respectively. We determined that the micromotor speed changes depending on the type of dyes, due to variations in their photodegradation rates. In addition, following the deposition of a paramagnetic Ni layer between the Au and TiO2 layers, the micromotor can be precisely navigated under an external magnetic field. Such magnetic micromotors not only facilitate the recycling of micromotors, but also allow reusability in the context of dye detection and degradation. In general, such photocatalytic micro-/nanomotors provide considerable potential for the rapid detection and "on-the-fly" degradation of dye pollutants in aqueous environments.

pH responsive polyurethane (core) and cellulose acetate phthalate (shell) electrospun fibers for intravaginal drug delivery.

In this study we present the use of co-axial electrospinning to produce core-shell composite micro-/nano- fibers of polyurethane (PU) and cellulose acetate phthalate (CAP). The designed fibers possess enhanced mechanical properties with a tensile strength of 13.27±2.32MPa, which is a clear improvement over the existing CAP fibers that suffer from a poor mechanical strength (0.2±0.03MPa). The CAP imparts pH responsiveness to the core-shell structure giving the fibers potential for "semen sensitive" (intravaginal) drug delivery.

Tuning of Polymeric Nanoparticles by Coassembly of Thermoresponsive Polymers and a Double Hydrophilic Thermoresponsive Block Copolymer.

The coassembly behavior of thermoresponsive statistical copolymers and a double hydrophilic block copolymer having a permanently hydrophilic block and a thermoresponsive block is investigated. By adjusting the hydrophilicity of the thermoresponsive statistical copolymers, hybrid nanoparticles are obtained with various ratios of the two species. Importantly, the size of these nanoparticles can be controlled in between 40 and 250 nm dependent on the TCP and the amount of statistical copolymers in the solution. Simultaneous analysis of static and dynamic light scattering data indicates that the possible structure of nanoparticles varies from hard sphere to less compact architecture and most probably depends on a difference between cloud point temperatures of individual components. This developed coassembly method provides a simple platform for the preparation of defined polymeric nanoparticles.

Highly Efficient Light-Driven TiO2-Au Janus Micromotors.

A highly efficient light-driven photocatalytic TiO2-Au Janus micromotor with wireless steering and velocity control is described. Unlike chemically propelled micromotors which commonly require the addition of surfactants or toxic chemical fuels, the fuel-free Janus micromotor (diameter ∼1.0 µm) can be powered in pure water under an extremely low ultraviolet light intensity (2.5 × 10(-3) W/cm(2)), and with 40 × 10(-3) W/cm(2), they can reach a high speed of 25 body length/s, which is comparable to common Pt-based chemically induced self-electrophoretic Janus micromotors. The photocatalytic propulsion can be switched on and off by incident light modulation. In addition, the speed of the photocatalytic TiO2-Au Janus micromotor can be accelerated by increasing the light intensity or by adding low concentrations of chemical fuel H2O2 (i.e., 0.1%). The attractive fuel-free propulsion performance, fast movement triggering response, low light energy requirement, and precise motion control of the TiO2-Au Janus photocatalytic micromotor hold considerable promise for diverse practical applications.