Graphite oxide (GO) nanoplatelets with a thickness from 0.8 nm to 2 nm were prepared using a modified Hummers method. By employing GO nanoplatelets as nanofillers, poly(acrylic acid)-GO superabsorbent nanocomposites were synthesized by a facile solution polymerization of acrylic acid monomers using N,N 0 -methylenebisacrylamide as cross-linker and ammonium persulfate as initiator.The well-dispersed GO nanoplatelets in the polymer networks results in a significant improvement in absorbencies both in distilled water and saline solutions. With only a very low loading of GO in the superabsorbent nanocomposite, for example 0.073 wt%, its water absorbency reaches up to 508 g g À1 , which is nearly as twice that of the poly(acrylic acid) (PAA) superabsorbent. The superabsorbent nanocomposite also exhibits a superior water-retention ability compared with the control under the same conditions. Our study may provide a new way for the development of novel, GO-based superabsorbent nanocomposites with improved absorbency and may find a variety of useful applications.
A sensitive electrochemical sensor based on in situ modification of graphite electrode via graphene nanosheets (GNs) was developed as a green method for prazosin hydrochloride (PRA) analyses. In this study, GNs were electrochemically synthesized on the surface of graphite electrode via in situ approach and used for the analyses. The proposed sensor showed several advantages such as high sensitivity, low LOD, and excellent repeatability. The oxidation peak current at the optimum analytical conditions using a GNs/graphite electrode at pH 6.0 was linearly dependent on PRA concentration in the range of 0.09–100 µM. A LOD of 0.02 µM and RSD of 3.8 % for 10 µM solution of PRA with a great recovery were obtained.
Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT) occurs more frequently in cancer patients than in the general population. A retrospective cross-sectional study was carried out in patients with solid tumor complicated with VTE admitted to the Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology between January 1st, 2008 and December 31th, 2017. The incidence of VTE in hospitalized cancer patients was 1.8%, twice the incidence of VTE in hospitalized non-cancer patients. The annual incidence of cancer-associated VTE in our center varied between 1.6% in 2015 and 0.4% in 2009 with an overall average incidence of 1.3% over the research decade. BMI values of 549(67.7%) cancer patients were within the normal range, but none of patients had BMI greater than 35 kg/m2. 747(92.1%) cancer patients had ECOG PS score ≤ 2 and 481(59.3%) had distant metastasis. Patients with pancreatic, bladder, ovarian and endometrial cancer had the highest incidence of VTE. Upper extremity DVT (47.2%) was more common in cancer patients and might be closely associated with CVC (74.9%), while lower extremities DVT (36.1%) intended to PE development (15.0%). The annual incidence rates showed a fluctuating and upward trend over the research decade. VTE occurrence was closely related to tumor stage, tumor site, catheterization and anti-neoplasm therapy in cancer patients.
Mesoporous graphene with a surface area of 306 m2 g−1 was synthesized by employing CaCO3 microspheres as hard templates. By surface modification with polydimethylsiloxane (PDMS) through chemical vapor deposition, the wettability of as‐treated mesoporous graphene can be tailored to be superhydrophobic to water while superoleophilic to oils. The deposition of the low‐surface‐energy silicon‐coating originated from PDMS pyrolysis on porous graphene was confirmed by X‐ray photoelectron spectroscopy. As a result of its porous structures and excellent surface superhydrophobicity, the PDMS‐treated mesoporous graphene exhibits good selectivity, excellent recyclability, and good absorption performance (up to 66 g g−1) for a wide range of oils and organic solvents. Thus, leading to potential use in a variety of applications such as water treatment and purification as well as cleanup of oil spills.
In the study reported here, a novel amphiphilic poly(aminoethyl ethylene phosphate)/poly(L-lactide) (PAEEP-PLLA) copolymer was synthesized by ring-opening polymerization reaction. The perfluoropentane-filled PAEEP-PLLA nanobubbles (NBs) were prepared using the O 1 /O 2 /W double-emulsion and solvent-evaporation method, with the copolymer as the shell and liquid perfluoropentane as the core of NBs. The prepared NBs were further conjugated with lactoferrin (Lf) for tumor-cell targeting. The resulting Lf-conjugated amphiphilic poly(aminoethyl ethylene phosphate)/poly(L-lactide) nanobubbles (Lf-PAEEP-PLLA NBs) were characterized by photon correlation spectroscopy, polyacrylamide gel electrophoresis, Fourier transform infrared spectroscopy, and transmission electron microscopy. The average size of the Lf-PAEEP-PLLA NBs was 328.4±5.1 nm, with polydispersity index of 0.167±0.020, and zeta potential of −12.6±0.3 mV. Transmission electron microscopy imaging showed that the Lf-PAEEP-PLLA NBs had a near-spherical structure, were quite monodisperse, and there was a clear interface between the copolymer shell and the liquid core inside the NBs. The Lf-PAEEP-PLLA NBs also exhibited good biocompatibility in cytotoxicity and hemolysis studies and good stability during storage. The high cellular uptake of Lf-PAEEP-PLLA NBs in C6 cells (low-density lipoprotein receptor-related protein 1-positive cells) at concentrations of 0–20 µg/mL indicated that the Lf provided effective targeting for brain-tumor cells. The in vitro acoustic behavior of Lf-PAEEP-PLLA NBs was evaluated using a B-mode clinical ultrasound imaging system. In vivo ultrasound imaging was performed on tumor-bearing BALB/c nude mice, and compared with SonoVue ® microbubbles, a commercial ultrasonic contrast agent. Both in vitro and in vivo ultrasound imaging indicated that the Lf-PAEEP-PLLA NBs possessed strong, long-lasting, and tumor-enhanced ultrasonic contrast ability. Taken together, these results indicate that Lf-PAEEP-PLLA NBs represent a promising nano-sized ultrasonic contrast agent for tumor-targeting ultrasonic imaging.
Early diagnosis of myocardial ischaemia-reperfusion (MI/R) injury is important for protecting the myocardium and improving patient prognoses. Fortunately, the platelet membrane possesses the ability to target the region of MI/R injury. Therefore, we hypothesized that platelet membrane-coated particles (PMPs) could be used to detect early MI/R injury by ultrasound imaging. We designed PMPs with a porous polylactic-co-glycolic acid (PLGA) core coated with a platelet membrane shell. Red blood cell membrane-coated particles (RMPs) were fabricated as controls. Transmission electron microscopy (TEM) and fluorescence microscopy were applied to confirm the membrane coatings of the PMPs and RMPs. In vitro imaging of the PMPs and RMPs was verified. Moreover, binding experiments were designed to examine the targeting ability of the PMPs. Finally, we assessed the signal intensity of the adherent PMPs in the risk area and remote area by ultrasound imaging based on an MI/R rat model. The platelet membrane equipped the PMPs with an accurate targeting ability. Compared with RMPs, PMPs showed significantly more adhesion to human umbilical vein endothelial cells and collagen IV in vitro. Both PMPs and RMPs exhibited good enhancement ability in vitro and in vivo. Furthermore, the signal intensity of PMPs in the risk area was significantly higher than that in remote areas. These results were further validated by an immunofluorescence assay and ex vivo fluorescence imaging. In summary, ultrasound imaging with PMPs can detect early MI/R injury in a noninvasive manner.
Kluyveromyces marxianus GX-15 was mutated multiple times by alternately treatment with UV irradiation and NTG for two cycles. Four mutant strains with improved ethanol yield were obtained. The maximum ethanol concentration, ethanol yield coefficient and theoretical ethanol yield of the best mutant strain, GX-UN120, was 69 g/l, 0.46 g/g and 91%, respectively, when fermenting 150 g glucose/l at 40°C. The corresponding values for GX-15 were 58 g/l, 0.39 g/g and 76%, respectively. GX-UN120 grew well in 11% (v/v) of ethanol, while GX-15 could not grow when ethanol was greater than 8% (v/v).
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