19 research outputs found
Enhanced hydrophilicity and antibacterial activity of PVDF ultrafiltration membrane using Ag3PO4/TiO2 nanocomposite against E. coli
Ag3PO4/TiO2, nanocomposite was fabricated by an in situ precipitation method and then blended into poly(vinylidene fluoride) (PVDF) casting solution to prepare the ultrafiltration membrane via wet phase inversion technique. The water flux and bovine serum albumin (BSA) rejection rate of membrane were investigated; meanwhile, the ultrafiltration membrane morphologies and structural properties were analyzed using scanning electron microscope (SEM) and X-ray diffraction. Compared with the control membrane, the permeate performance of blended membranes was improved while possessing a steady BSA retention due to enhanced hydrophilicity. Mechanical tests revealed that the modified membranes exhibited a larger tensile strength and breakage elongation. SEM images and the halo zone testing were employed to assess the antibacterial performances of the nanocomposite membranes against Escherichia coli. The antibacterial tests confirmed that the modified membranes showed an effective antibacterial property against E. coli
Longan seed and mangosteen skin based activated carbons for the removal of Pb(II) ions and rhodamine-B dye from aqueous solutions
Agricultural biomass wastes of longan seed and mangosteen skin were collected as precursors to prepare activated carbons (LS-AC-5 and MS-AC-5, respectively) through carbonization at medium temperature and KOH activation at high temperature. Their pore structures, structural properties and surface morphologies were characterized by X-ray diffractometer, Brunauer–Emmett–Teller surface measurement system, and scanning electron microscopy, respectively. Effects of contact time and pH on adsorption performances of samples were investigated by removal of Pb(II) ions and Rhodamine-b from aqueous solutions. Experimental adsorption isotherms of Rhodamine-b and Pb(II) ions on LS-AC-5 and MS-AC-5 fitted well with the Langmuir model. Results further showed that MS-AC-5 exhibited a larger surface area of 2960.56 m2/g and larger portions of micropores and mesopores (pore volume of 1.77 cm3/g) than LS-AC-5 (surface area: 2728.98 m2/g; pore volume: 1.39 cm3/g). Maximum monolayer adsorption capabilities of 1265.82 and 117.65 mg/g for Rhodamine-b and Pb(II) ions on MS-AC-5 were higher than those on LS-AC-5 (1000.20 and 107.53 mg/g), respectively
Universal three-state nematicity and magneto-optical Kerr effect in the charge density waves in AVSb (A=Cs, Rb, K)
The kagome lattice provides a fascinating playground to study geometrical
frustration, topology and strong correlations. The newly discovered kagome
metals AVSb (A=K, Rb, Cs) exhibit various interesting phenomena
including topological band structure and superconductivity. Nevertheless, the
nature of the symmetry breaking in the CDW phase is not yet clear, despite the
fact that it is crucial to understand whether the superconductivity is
unconventional. In this work, we perform scanning birefringence microscopy and
find that six-fold rotation symmetry is broken at the onset of the CDW
transition temperature in all three compounds. Spatial imaging and angle
dependence of the birefringence show a universal three nematic domains that are
120 to each other. We propose staggered CDW orders with a relative
phase shift between layers as a possibility to explain the three-state
nematicity in AVSb. We also perform magneto-optical Kerr effect and
circular dichroism measurements on all three compounds, and the onset of the
both signals is at the CDW transition temperature, indicating broken
time-reversal symmetry and the existence of the long-sought loop currents in
the CDW phase. Our work strongly constrains the nature of the CDWs and sheds
light on possible unconventional superconductivity in AVSb.Comment: 7 pages, 4 figures, submitted versio
Acetylcholinesterase Immobilization on ZIF-8/Graphene Composite Engenders High Sensitivity Electrochemical Sensing for Organophosphorus Pesticides
A sensitive and flexible detection method for organophosphorus pesticides (OPs) detection is a crucial request to avoid their further expanded pollution. Herein, an acetylcholinesterase (AChE) electrochemical sensor, based on the co-modification of ZIF-8 and graphene (GR), was constructed for the detection of OPs. ZIF-8/GR composite can provide a stable and biocompatible environment for the loading of AChE and can accelerate the chemical reaction on the electrode surface. After optimization, the linear detection range of the constructed AChE-CS/GR/ZIF-8/GCE sensor for ICP was 0.5–100 ng/mL (1.73–345.7 nM), and the limit of detection was 0.18 ng/mL (0.62 nM). Moreover, high sensitivity and high specificity of the sensor were also achieved in actual cabbage and tap water samples. Therefore, it has great potential for the application of organophosphorus pesticide residue analysis
Acetylcholinesterase Immobilization on ZIF-8/Graphene Composite Engenders High Sensitivity Electrochemical Sensing for Organophosphorus Pesticides
A sensitive and flexible detection method for organophosphorus pesticides (OPs) detection is a crucial request to avoid their further expanded pollution. Herein, an acetylcholinesterase (AChE) electrochemical sensor, based on the co-modification of ZIF-8 and graphene (GR), was constructed for the detection of OPs. ZIF-8/GR composite can provide a stable and biocompatible environment for the loading of AChE and can accelerate the chemical reaction on the electrode surface. After optimization, the linear detection range of the constructed AChE-CS/GR/ZIF-8/GCE sensor for ICP was 0.5–100 ng/mL (1.73–345.7 nM), and the limit of detection was 0.18 ng/mL (0.62 nM). Moreover, high sensitivity and high specificity of the sensor were also achieved in actual cabbage and tap water samples. Therefore, it has great potential for the application of organophosphorus pesticide residue analysis
Reliability enhancement of InGaAs/AlGaAs quantum-well lasers on on-axis Si (001) substrate
The enhancement of the reliability of the silicon-based III–V quantum well lasers, especially of those on an on-axis Si (001) substrate, is of great importance now a days for the development of Si-based photonic and even optoelectronic integrated circuits and is really quite challenging. As an experimental advancement, mainly by inserting a pair of InAlAs strained layers separately into the upper and lower AlGaAs cladding layers to effectively prevent the formation of the in-plane gliding misfit-dislocations within the boundary planes of the active region, the longest room-temperature and continuous-wave lifetime of the InGaAs/AlGaAs quantum well lasers on an on-axis Si (001) substrate with a cavity length of 1500 µm and a ridge width of 20 µm has been prolonged from a very initial record of ∼90 s to the present length longer than 31 min. While, the highest continuous-wave operation temperature of another one with a cavity length of 1000 µm and a ridge width of 10 µm has been shown as 103 °C with an extracted characteristic temperature of 152.7 K, further enhancement of the device reliability is still expected and would mainly depend on the level of the threading-dislocation-density reduction in the GaAs/Si virtual substrate
Enzyme-Activated G‑Quadruplex Synthesis for in Situ Label-Free Detection and Bioimaging of Cell Apoptosis
Fluorogenic
probes targeting G-quadruplex structures have emerged
as the promising toolkit for functional research of G-quadruplex and
biosensor development. However, their biosensing applications are
still largely limited in in-tube detection. Herein, we proposed a
fluorescent bioimaging method based on enzyme-generated G-quadruplexes
for detecting apoptotic cells at the cell and tissue level, namely,
terminal deoxynucleotidyl transferase (TdT)-activated de novo G-quadruplex
synthesis (TAGS) assay. The detection target is genomic DNA fragmentation,
a biochemical hallmark of apoptosis. The TAGS assay can efficiently
“tag” DNA fragments via using their DNA double-strand
breaks (DSBs) to initiate the de novo synthesis of G-quadruplexes
by TdT with an unmodified G-rich dNTP pool, followed by a rapid fluorescent
readout upon the binding of thioflavin T (ThT), a fluorogenic dye
highly specific for G-quadruplex. The feasibility of the TAGS assay
was proved by in situ sensitive detection of individual apoptotic
cells in both cultured cells and tissue sections. The TAGS assay has
notable advantages, including being label-free and having quick detection,
high sensitivity and contrast, mix-and-read operation without tedious
washing, and low cost. This method not only shows the feasibility
of G-quadruplex in tissue bioanalysis but also provides a promising
tool for basic research of apoptosis and drug evaluation for antitumor
therapy
Phylogeny, Pathogenicity, Transmission, and Host Immune Responses of Four H5N6 Avian Influenza Viruses in Chickens and Mice
H5Nx viruses have continuously emerged in the world, causing poultry industry losses and posing a potential public health risk. Here, we studied the phylogeny, pathogenicity, transmission, and immune response of four H5N6 avian influenza viruses in chickens and mice, which were isolated from waterfowl between 2013 and 2014. Their HA genes belong to Clade 2.3.4.4, circulated in China since 2008. Their NA genes fall into N6-like/Eurasian sublineage. Their internal genes originated from different H5N1 viruses. The results suggested that the four H5N6 viruses were reassortants of the H5N1 and H6N6 viruses. They cause lethal infection with high transmission capability in chickens. They also cause mild to severe pathogenicity in mice and can spread to the brain through the blood–brain barrier. During the infection, the viruses result in the up-regulation of PRRs and cytokine in brains and lungs of chickens and mice. Our results suggested that the high viral loads of several organs may result in disease severity in chickens and mice; there were varying levels of cytokines induced by the H5N6 viruses with different pathogenicity in chickens and mice
Hyperhomocysteinemia potentiates megakaryocyte differentiation and thrombopoiesis via GH-PI3K-Akt axis
Abstract Hyperhomocysteinemia (HHcy) is closely associated with thrombotic diseases such as myocardial infarction and stroke. Enhanced platelet activation was observed in animals and humans with HHcy. However, the influence of HHcy on thrombopoiesis remains largely unknown. Here, we reported increased platelet count (PLT) in mice and zebrafish with HHcy. In hypertensive patients (n = 11,189), higher serum level of total Hcy was observed in participants with PLT ≥ 291 × 109/L (full adjusted β, 0.59; 95% CI 0.14, 1.04). We used single-cell RNA sequencing (scRNA-seq) to characterize the impact of Hcy on transcriptome, cellular heterogeneity, and developmental trajectories of megakaryopoiesis from human umbilical cord blood (hUCB) CD34+ cells. Together with in vitro and in vivo analysis, we demonstrated that Hcy promoted megakaryocytes (MKs) differentiation via growth hormone (GH)-PI3K-Akt axis. Moreover, the effect of Hcy on thrombopoiesis is independent of thrombopoietin (TPO) because administration of Hcy also led to a significant increase of PLT in homozygous TPO receptor (Mpl) mutant mice and zebrafish. Administration of melatonin effectively reversed Hcy-induced thrombopoiesis in mice. ScRNA-seq showed that melatonin abolished Hcy-facilitated MK differentiation and maturation, inhibited the activation of GH-PI3K-Akt signaling. Our work reveals a previously unrecognized role of HHcy in thrombopoiesis and provides new insight into the mechanisms by which HHcy confers an increased thrombotic risk. Trial Registration clinicaltrials.gov Identifier: NCT00794885