Structures and Wettability Alterations of a Series of Bispyridinium Dibromides Exchanged with Reduced-Charge Montmorillonites

Capillary rise tests were performed to investigate the influences that the structure of the modifier and layer charge of clay had on wetting properties of organoclays, which were prepared by ion exchange using bispyridinium dibromides (BPs) with different spacer length and the reduced-charge montmorillonites (RCMs). Their structures were examined by Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nitrogen adsorption–desorption isotherms. The results indicated that BPs had been successfully intercalated into interlayers and lay in the monolayer. The <i>d</i>₀₀₁ basal spacing of organo-RCMs increased with the spacer length of BPs increasing, whereas it decreased gradually as the layer charge of the RCMs was decreased, independent of the type of BPs. Whether the organic modification made the Brunauer–Emmett–Teller (BET) surface area increase or decrease depended upon the size of the organic cations and the layer charge of the clays. The wettability alterations of the organo-RCMs for deionized water and cyclohexane were also compared. Both the spacer length of BPs and the layer charge of RCMs had important effects on the relative wettability of organo-RCMs. The hydrophilicity of organo-RCMs was increased with the spacer length of BPs increasing, namely, in the order as follows: C2-2Py-RCMs < C6-2Py-RCMs < C10-2Py-RCMs. In addition, the hydrophobicity was increased with a decrease in the layer charge. The results of this work were supposed to provide some reference information for regulating the wettability of the organo-RCMs by simultaneously controlling the type of modifiers along with the layer charge characteristics, to provide theoretical guidance for the favorable change in reservoir wettability

LoFGAN: Fusing Local Representations for Few-shot Image Generation

Given only a few available images for a novel unseen category, few-shot image generation aims to generate more data for this category. Previous works attempt to globally fuse these images by using adjustable weighted coefficients. However, there is a serious semantic misalignment between different images from a global perspective, making these works suffer from poor generation quality and diversity. To tackle this problem, we propose a novel Local-Fusion Generative Adversarial Network (LoFGAN) for few-shot image generation. Instead of using these available images as a whole, we first randomly divide them into a base image and several reference images. Next, LoFGAN matches local representations between the base and reference images based on semantic similarities, and replaces the local features with the closest related local features. In this way, LoFGAN can produce more realistic and diverse images at a more fine-grained level, and simultaneously enjoy the characteristic of semantic alignment. Furthermore, a local reconstruction loss is also proposed, which can provide better training stability and generation quality. We conduct extensive experiments on three datasets, which successfully demonstrates the effectiveness of our proposed method for few-shot image generation and downstream visual applications with limited data. Code is available at https://github.com/edward3862/LoFGAN-pytorch

Montmorillonite Functionalized with Zwitterionic Surfactant as a Highly Efficient Adsorbent for Herbicides

A novel adsorbent (DHAPS-Mt) was prepared with Na montmorillonite (Na-Mt) and a zwitterionic surfactant (3-(<i>N</i>,<i>N</i>-dimethylhexadecylammonio)­propanesulfonate, DHAPS). Then DHAPS-Mt was characterized by a series of characterization techniques and applied in herbicide adsorption. Two representative herbicides in agriculture, paraquat (PQ, 1,1′-dimethyl-4,4′-dipyridinium dichloride) and amitrole (AMT, 3-amino-1,2,4-triazole), were removed by DHAPS-Mt varying with different experimental conditions. The adsorption mechanisms, obtained from a comparison of adsorption capacities of DHAPS-Mt and two other kinds of organo­montmorillonite (CTAB-Mt and SDS-Mt), suggested that the surface electrostatic adsorption and electrostatic attraction between herbicide cations and negatively charged group of DHAPS were the main interaction in PQ and AMT removal. The results of anionic dye (methyl orange) removal onto these three kinds of clay indicated that DHAPS-Mt might be applied in the treatment of mixed-ion wastewater. The kinetic study indicated that the adsorption of herbicides onto DHAPS-Mt followed the pseudo-second-order model, and the Langmuir isotherm model agreed well with the experimental data. Furthermore, thermodynamic parameters illustrated that PQ removal by DHAPS-Mt was more spontaneous at higher temperature, and the process was endothermic and randomness increasing in nature, while the AMT removal presented an opposite tendency

tUCHL1 binds to MPF components p34^cdc2 or cyclin B1 in different oocyte protein extracts.

<p>Panel <b>A</b>: A pull-down analysis (specific adsorption) with recombinant GST-tUCHL1 and with GST as a control, which were coupled to Sepharose 4B beads, respectively, from 200 µg of Lm, Li, Hm, Hi oocyte soluble protein extracts, was performed for <b>p34^cdc2</b> assay by western Blotting analysis with beta-actin detection as a pull-down sample loading control. Panel B: Western blotting analysis for cyclin B1 after pull-down analysis with GST-tUCHL1 from oocyte protein extracts of Lm and Li, with 20 µg of total protein extracts (Lm and Li) as loading control was performed. Panel C: The results of immunoprecipitation (IP) with mouse monoclonal antibodies against <b>p34^cdc2</b> and cyclin B1 from 120 µg of toad oocyte protein extracts are shown. Isolated protein complexes were then detected by western blotting analysis for tUCHL1. Loading denotes the lanes with 15 µg of total protein extracts as loading control. Lm and Li indicate immature or mature LTE-oocytes; Hm and Hi indicate THE-oocytes with or without progesterone treatment, respectively.</p

Tissue-specific expression of tUCHL1 in toads.

<p>The soluble protein extracts were separated by 12% SDS-PAGE, and the protein bands were identified using mouse monoclonal antibody against tUCHL1, colored with DAB on the nitrocellulose membrane. In each lane, 20 μg of soluble protein extract from various tissues was loaded separately, except for 0.5 μg of recombinant protein as a control. The abbreviations are as follows: B: brain; Sk: skin; Sp: spermary; St: stomach; Li: liver; In: intestine; tUCHL1: Recombinant tUCHL1 expressed in <i>E. coli</i> (DE3), which has a molecular weight of approximately 29 kDa; O: oocyte; Ki: Kidney; Mu: muscle; Lu: lung; H: heart; M: marker. The experiment was independently repeated twice.</p

The comparisons of UCH activity of tUCHL1 between LTE-oocytes and HTE-oocytes.

<p>A: ubiquitin carboxyl-terminal hydrolase (UCH) activity of four types of oocyte protein extracts. Lm: mature LTE-oocytes; Li: immature LTE-oocytes; Hm: progesterone treated HTE-oocytes; Hi: HTE-oocytes without progesterone treatment. Oocyte soluble protein extracts were prepared at the final concentration of 20 µg/ml, and the two types of recombinant proteins are both used at the concentration of 20 nmol/L. The sharp drops in the curves at the beginning were caused by the light path closure to add reaction substrate Ub-AMC. The experiment was repeated twice independently, and the recombinant tUCHL1 was applied at a relative low concentration to obtain an appropriate slope. To draw all the curves in the same diagram, their starting points were adjusted.</p

Pull-down analysis with recombinant p13^suc1 for tUCHL1 isolation from oocyte protein extracts.

<p>Panel A: After toad oocyte protein 500 µg extracts were treated with the ATP system, and affinity adsorption (pull-down) was performed with recombinant p13^suc1-argrose to isolate protein complex from the oocyte protein extracts. The isolated protein complex was used to detect tUCHL1 by western Blotting analysis. Lanes 1-4 show results of the pull-down, and lanes 5-6 contained two loading controls with 20 μg of total protein extracts. B: Affinity adsorption results without the ATP system treatment run in parallel to the lanes in panel A. Lanes 1-4 are the corresponding adsorption results, and lane 5-6 indicate two other loading controls than those used in panel A. Lm and Li indicate immature or mature LTE-oocytes; Hm and Hi indicate THE-oocytes with or without progesterone treatment, respectively.</p

Immunological localization of tUCHL1 in toad oocytes.

<p>A: Control for immunological detection in B with primary antibody blocking. B: Immunohistochemical detection of tUCHL1 on sections of a juvenile toad's ovary, visualized in brown using a DAB kit. C: Control for immunological detection in D and E with primary antibody blocking. D: tUCHL1 immunological detection in immature LTE-oocytes (Li) at stage IV, colored red with an AEC kit. E: tUCHL1 detection in mature oocytes (Lm) in parallel with D. F: control for immunofluorescent detection in G and H with primary antibody blocking. G: Immunofluorescence of tUCHL1 in HTE-oocytes without progesterone treatment (Hi). H: tUCHL1 immunofluorescence detection in immature LTE-oocytes (Li) in parallel with G. Yellow arrows indicate the distribution of tUCHL1. B: Western blotting analysis of tUCHL1 in different parts of toad oocytes. Lane I: 1/10 volume of the insoluble protein part derived from 40 LTE-oocytes; S: 1/10 volume of the soluble protein part derived from 40 LTE-oocytes; GV: protein extract derived from 10 nuclei isolated from LTE-oocytes; Li: soluble protein extract from 2 immature LTE-oocytes; Lm: soluble protein extract from 2 mature LTE-oocytes; Hi: soluble protein extract from 2 HTE-oocytes without progesterone treatment; Hm: soluble protein extract from 2 progesterone treated HTE-oocytes. All the bands in Panel B were visualized by chemiluminescence. Each experiment was repeated twice independently. </p

The protein quantification assays of tUCHL1, p34^cdc2 and cyclin B1 in four different oocyte protein extracts.

<p>The protein amounts of tUCHL1 and MPF subunits (p34^cdc2 and cyclin B1) in the four types of oocyte protein extracts were evaluated in reference to beta-actin. The total soluble protein extracts of 20 µg individually from Lm, Li, Hm and Hi samples were used to detect tUCHL1, p34^cdc2 and cyclin B1 by the western Blotting method, and here, all the bands were visualized by chemiluminescence. Lm and Li indicate immature or mature LTE-oocytes; Hm and Hi indicate THE-oocytes with or without progesterone treatment. Panel A presents a typical picture of western Blotting bands among three independent experiments. Panel B shows the optical density values from three independent western Blotting results. The longitudinal axis indicates ratios between the optical density values of the denoted proteins and those of beta-actin. According to t-test analysis, only p34^cdc2 among the denoted proteins was significantly different in its relative values between Lm and Hm (p=0.027), or Li and Hi (p=0.010). A significant level less than 0.05 is marked at the tops of corresponding bars of Hm and Hi with an asterisk. </p

Enhanced Detection Specificity and Sensitivity of Alzheimer’s Disease Using Amyloid-β-Targeted Quantum Dots

Diagnostics of Alzheimer’s disease (AD) commonly employ the use of fluorescent thioflavin derivatives having affinity for the amyloid-β (Aβ) proteins associated with AD progression. However, thioflavin probes have limitations in their diagnostic capabilities arising from a number of undesireable qualities, including poor photostability, weak emission intensity, and high emission overlap with the backgound tissue autofluorescence. To overcome such limitations, we have developed nanoformulated probes consisting of a red-emitting fluorescent quantum dot (QD) core encapsulated in a PEGylated shell with benzotriazole (BTA) targeting molecules on the surface (QD-PEG-BTA). The combination of strong red fluorescence, multivalent binding, and decreased backgound signal and nonspecific binding provided the ability of the QD-PEG-BTA probes to achieve detection sensitivites 4 orders of magnitude greater than those of conventional thioflavin derivatives. This study opens the door for the use of QDs in AD detection applications