Small-diameter PCL/PU vascular graft modified with heparin-aspirin compound for preventing the occurrence of acute thrombosis.

The occurrence of acute thrombosis, directly related to platelet aggregation and coagulant system, is a considerable reason for the failure of small-diameter vascular grafts. Heparin is commonly used as a functional molecule for graft modification due to the strong anticoagulant effect. Unfortunately, heparin cannot directly resist the adhesion and aggregation of platelets. Therefore, we have prepared a heparin-aspirin compound by coupling heparin with aspirin, an antiplatelet drug, and covalently grafted it onto the surface of polycaprolactone/polyurethane composite tube. In this way, the graft not only showed a dual function of both anticoagulation and antiplatelet, but also effectively avoided the rapid drug release and excessive toxicity to other organs caused by simple blending the medicine with material matrix. The compound retained the original function of heparin, showing good hydrophilicity and biocompatibility, which could promote the adhesion and proliferation of endothelial cells (ECs) and facilitate the process of tissue regeneration. What's more, the compound showed more effective than heparin in reducing platelet activation and preventing thrombosis. The graft modified by this compound maintained completely unobstructed for one month of implantation, while severe obstruction or stenosis occurred in PCL/PU and PCL/PU-Hep lumen at the first week, verifying the effect of the compound on preventing acute thrombosis. In general, this study proposed a designing method for small-diameter vascular graft which could prevent acute thrombosis and promote intimal construction.

Liquid metal integrated PU/CNT fibrous membrane for human health monitoring.

Wearable flexible sensors are widely used in several applications such as physiological monitoring, electronic skin, and telemedicine. Typically, flexible sensors that are made of elastomeric thin-films lack sufficient permeability, which leads to skin inflammation, and more importantly, affects signal detection and consequently, reduces the sensitivity of the sensor. In this study, we designed a flexible nanofibrous membrane with a high air permeability (6.10 mm/s), which could be effectively used to monitor human motion signals and physiological signals. More specifically, a flexible membrane with a point (liquid metal nanoparticles)-line (carbon nanotubes)-plane (liquid metal thin-film) multiscale conductive structure was fabricated by combining liquid metal (LM) and carbon nanotubes (CNTs) with a polyurethane (PU) nanofibrous membrane. Interestingly, the excellent conductivity and fluidity of the liquid metal enhanced the sensitivity and stability of the membrane. More precisely, the gauge factor (GF) values of the membrane is 3.0 at 50% strain and 14.0 at 400% strain, which corresponds to a high strain sensitivity within the whole range of deformation. Additionally, the proposed membrane has good mechanical properties with an elongation at a break of 490% and a tensile strength of 12 MPa. Furthermore, the flexible membrane exhibits good biocompatibility and can efficiently monitor human health signals, thereby indicating potential for application in the field of wearable electronic devices.

Effects of the Separator MOF-Al2O3 Coating on Battery Rate Performance and Solid-Electrolyte Interphase Formation.

Metal organic frameworks (MOFs) have unique advantages in optimizing the ionic conductivity of battery separators because of their rich cavity structure and highly ordered and connected pores. In this study, we used a hydrothermal method to synthesize a functional material, Ag-MOF crystal, as a separator coating content, and then studied the properties and application effect of the MOF-Al2O3-blended coating applying to a polyethylene (PE) separator (MOFxAl1-x/PE). Results show that MOF0.08Al0.92/PE (MOF/Al2O3 = 0.08:0.92) used in NCM811||Li cells significantly not only improves the fast charge-discharge performance of the cells but also inhibits the growth of lithium dendrites during long-term charge-discharge cycling; the Li+ transference number (tLi+) of the MOF0.08Al0.92/PE composite separator is 0.61; the Li||separator||Li half-cell circulates stably for 1000 h at varying current density from 0.5 to 10 mA cm-2 and only produces low overpotentials, indicating that MOF0.08Al0.92 stabilizes lithium. The initial capacity of the NCM811||Li cell using the MOF0.08Al0.92/PE separator is 165.0 mA h g-1, its capacity retention is 70.67% after 300 cycles at 5 C, and the interface resistance of the cells only increases from 13.8 to 31.5 Ω, whereas the capacity retention of Al2O3/PE separator batteries is only 40.41% (62.2 mA h g-1) under the same conditions. During the charge-discharge cycling, the MOF-Al2O3 coating induces the lithium anode to quickly form a stable and dense solid-electrolyte interphase layer, promotes the uniform deposition of Li+, and inhibits the growth of lithium dendrites as well.

A biomimetic orthogonal-bilayer tubular scaffold for the co-culture of endothelial cells and smooth muscle cells.

In blood vessels, endothelial cells (ECs) grow along the direction of blood flow, while smooth muscle cells (SMCs) grow circumferentially along the vessel wall. To mimic this structure, a polycaprolactone (PCL) tubular scaffold with orthogonally oriented bilayer nanofibers was prepared via electrospinning and winding. ECs were cultured on the inner layer of the scaffold with axial nanofibers and SMCs were cultured on the outer layer of the scaffold with circumferential nanofibers. Fluorescence images of the F-actin distribution of ECs and SMCs indicated that cells adhered, stretched, and proliferated in an oriented manner on the scaffold. Moreover, layers of ECs and SMCs formed on the scaffold after one month of incubation. The expression levels of platelet-endothelial cell adhesion molecule 1 (PECAM-1) and a contractile SMC phenotype marker in the EC/SMC co-culture system were much higher than those in individual culture systems, thus demonstrating that the proposed biomimetic scaffold promoted the intercellular junction of ECs and preserved the contractile phenotype of SMCs.

Colorimetric Immunosensor Based on Au@g-C3N4-Doped Spongelike 3D Network Cellulose Hydrogels for Detecting α-Fetoprotein.

A colorimetric immunoassay is a powerful tool for detecting tumor markers, with outstanding advantages of visualization and convenience. This study designed a colorimetric immunoassay using the antibody/antigen to control the catalytic activity to be "switched on/off". This system, where Au NPs (18.5 ± 3.9 nm) were loaded on the g-C3N4 nanosheets that were fixed in a three-dimensional porous cellulose hydrogel, was used as a binding site for the antibody/antigen. After being incubated with an antibody of a cancer marker, the turned-off catalytic sites on Au NPs in Au@g-C3N4/microcrystalline cellulose hydrogels would not be "turned on" until the corresponding antigen was added. The number of the recovered Au active sites was related to the amount of the antigen added. The Fourier transform infrared and X-ray photoelectron spectroscopy measurements did not detect the existence of Au-S bonds. Catalyzed by the turned-on Au NPs, 4-nitrophenol was reduced to 4-aminophenol accompanied by a color fading. The color and the absorption spectrum changes in the process were used as the colorimetric quantitative basis for immunoassays. The colorimetric immunoassay showed a linear relationship with the liver cancer marker (α-fetoprotein, AFP) in the range of 0.1-10 000 ng/mL with the detection limit of 0.46 ng/mL. In addition, 4-nitrophenol had a significant color fading when the AFP concentration exceeded the healthy human threshold. The clinical patient's serum test results obtained from the developed colorimetric immunosensor were consistent with those obtained from the commercial enzyme-linked immunosorbent assay. Furthermore, the immunosensor exhibited a good selectivity, repeatability, and stability, which demonstrated its potential for practical diagnostic application.

Asymmetrically coated LAGP/PP/PVDF-HFP composite separator film and its effect on the improvement of NCM battery performance.

Li1.5Al0.5Ge1.5(PO4)3 (LAGP) is an inorganic solid electrolyte with a Na superionic conductor (NASICON) structure that provides a channel for lithium ion transport. We coated LAGP particles on one side of a polypropylene (PP) separator film to improve the ionic conductivity of the separator, and water-dispersed polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) on the other side to reduce the interfacial resistance between the separator and the lithium metal anode. The results show that the LAGP/PP/PVDF-HFP separator has a high ionic conductivity (1.06 mS cm-1) at room temperature (PP separator: 0.70 mS cm-1), and an electrochemical window of 5.2 V (vs. Li+/Li). The capacity retention of a NCM|LAGP/PP/PVDF-HFP|graphite full cell is 81.0% after 300 charge-discharge cycles at 0.2C. When used in a NCM|LAGP/PP/PVDF-HFP|Li half-cell system, the initial discharge capacity is 172.5 mA h g-1 at 0.2C, and the capacity retention is 83.2% after 300 cycles. More significantly, the surface of the Li anode is smooth and flat after 200 cycles. The interface resistance increased from 7 to 109 Ω after 100 cycles at 0.2C. This indicates that the synergistic effect of the asymmetric coated LAGP and PVDF-HFP is beneficial to inhibiting the growth of lithium dendrites in the battery and reduces the interface resistance.

Syntheses of [12]aneN3-oligopeptide conjugates as effective DNA condensation agents.

With the aim to develop effective and low toxicity DNA condensation agents, a series of oligopeptide derived macrocyclic polyamine [12]aneN(3) conjugates 7a-h·3HCl have been designed and synthesized through multi-step amidation reactions. Structure-property study through gel electrophoresis proved that the conjugates containing high hydrophobic ending amino acids exhibited effective condensation ability at concentration of 150-250 µM, which was further confirmed by dynamic light scattering and atomic force microscopy experiments. EB displacement assay, ionic salt effect, and structure-property relationship in gel electrophoresis indicated that DNA condensation resulted from both the electrostatic interaction of [12]aneN(3) unit and hydrogen-bonding/hydrophobic multi-interaction of oligopeptide moiety in the conjugates with DNA. The reversible condensation process and their low cytotoxicity suggest that the new condensing agents are potential for the development of non-viral vectors.

[Clinical medicinal engineering support in disaster relief medicine].

Disaster Relief Medicine (DRM), a newly developed science, not only crosses Emergency Service and Critical Health Care, but also relates to other various fields such as Nursing, Clinical examination and Clinical Medicinal Engineering etc, all of which require competent Clinical Medicinal Engineers. Thus, a key subject of Clinical Engineering is to provide quality support to medical equipments, and to offer engineers educational training on this diverse science, in order to improve their professional and managerial skills. Based on DRM characteristics, specifically, based on our first hand experience during disaster relief effort in Wen-Chuan Earthquake, we documents our thoughts and discussion over the issues we found in above areas as listed in the article below.

Clinical observation on the treatment of childhood refractory idiopathic thrombocytopenic purpura with Dihuang Zhixue Capsule.

OBJECTIVE: To observe the clinical effect of Dihuang Zhixue Capsule (DZC, a Chinese preparation for cooling blood and dispelling toxic substances) in the treatment of childhood refractory idiopathic thrombocytopenic purpura (RITP), with cyclosporin A (CsA) used as the control. METHODS: Forty-one children of RITP were randomized into the treated group and the control group. The 21 patients in the treated group were orally given 2 to 3 DZC capsules each time, thrice a day and the 20 in the control group were given 3 mg/kg CsA per day, with 3 months as one therapeutic course. The therapeutic efficacy, platelet count and adverse reaction in the two groups were compared at the end of the course. RESULTS: (1) In the treated group, 1 (4.8%) patient was evaluated as cured, 3 (14.3%) as markedly effective, 5 (23.8%) as effective, 5 (23.8%) as improved, 7 (33.3%) as ineffective, with the total effective rate being 66.7%; while in the control group, the corresponding numbers were 0, 2 (10.0%), 2 (10.0%), 3 (15.0%), 13 (65.0%) and 35.0%, respectively, showing statistical significance in difference between the total effective rates of the two groups (xi(2)=4.11, P=0.0426). (2) As compared with the baseline, the platelet count increased in both groups after 2 months' treatment (P<0.05). After 3 months' treatment, the platelet count was higher in the treated group than in the control group (P<0.05). (3) The improvement of hemorrhage in the treated group after 8 weeks' treatment was better than that in the control group (P<0.05). (4) No apparent adverse reaction was observed in the treated group, while in the control group, hirsutism was shown in 15 cases; gingival hyperplasia in 10; digestive reaction in 5, liver function impairment in 5, hypertension in 2 and renal impairment in 2. CONCLUSION: The therapeutic efficacy of DZC is better than that of CsA, and DZC shows good compliance but brings no obvious adverse reaction.

Functional analysis of two Sp1/Sp3 binding sites in murine Nanog gene promoter.

Nanog gene plays a key role in maintaining pluripotency of ES cells and early embryonic cells. A 5' flank sequence of the Nanog gene has been reported to be regulated differentially, and two regulatory elements within the Nanog promoter, namely Oct-4 and Sox-2 binding sites, have been identified to regulate the transcriptional activity of Nanog gene. In this report, we identified the role of two putative Sp1 binding sites located in the Nanog gene 5'-flanking region in regulation of murine Nanog gene transcription. Mutation studies showed that the two sites were essential for the Nanog promoter activity. Gel shift and supershift analysis showed that both sites specifically bind Sp1 and Sp3. Furthermore, overexpression of dominant-negative Sp1 or Sp3 mutants significantly inhibits Nanog promoter activity. These results suggest that the transcription factor Sp1 and Sp3 are important for Murine Nanog gene expression.

Isolation and characterization of the murine Nanog gene promoter.

Nanog protein is expressed in the interior cells of compacted morulae and maintained till epiblasts but downregulated by implantation stage. It is also expressed in embryonic stem cells, embryonic carcinoma cells and embryonic germ cells but disappeared in differentiated ES cells. In this study, we have isolated, sequenced, and performed the first characterization of the Nanog promoter. The transcription start sites were mapped by primer extension analysis. Two promoter regions were found upstream the transcription start sites and the expression of major Nanog promoter/reporter gene construct is abolished in differentiated F9 EC cells as compared to the undifferentiated counterpart. We also showed that a putative octamer motif (ATGCAAAA) is necessary for the major promoter activity. Gel shift and supershift assays showed that Oct-1, Oct-4 and Oct-6 protein selectively bind to the octamer motif.

Nanosized particles of organically modified silica as microreactors to enhance the regioselectivity in the photocycloaddition of 9-substituted anthracenes.

[reaction: see text] Nanosized particles of modified silica with 3-ammoniumpropyl residue have been prepared and successfully used as microreactors to control the regioselectivity of the photocycloaddition of five 9-substituted anthracences [AnCH(2)N(+)(CH(3))(3)Br(-) (1), AnCH(2)COO(-)Na(+) (2), AnCH(2)CH(2)COOH (3), AnCH(2)OH (4), AnCH(3) (5), where An = 9-anthryl]. While the photocycloaddition of the five substrates in methanol mainly gave rise to their head-to-tail (h-t) photocyclomers, irradiation of 1-4 incorporated in the suspension of the modified silica in methanol almost exclusively yielded the head-to-head (h-h) photocyclomers with high quantum yields.