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ZrO2, a traditional inert transition metal oxide (TMO), can be prepared into ZrO2 nanofilms (NFs) with a single-layer thickness of only 2.5 nm through the generally applicable two-dimensional TMO synthesis strategy reported by us, and has displayed remarkable sensitivity and selectivity properties for triethylamine gas detection. [ABSTRACT FROM AUTHOR]

Exposure to air pollution has been closely associated with some cardiovascular disease. One of the mechanisms of PM2.5‐mediated heart injury may be to promote inflammation. We aim to investigate whether the main extract of Houttuynia cordata, 2‐undecanone, can prevent the inflammation caused by PM2.5, and to reveal the underlying mechanisms. The results showed that PM2.5 increased the expression of certain inflammatory cytokines, and caused oxidative damage in BALB/c mice and H9C2 cells. Supplementation with 2‐undecanone attenuated this PM2.5‐induced inflammatory injury and oxidative damage. Further, we elucidated that the protective effect of 2‐undecanone may be associated with NF‐κB and Nrf2/HO‐1 pathways. The NF‐κB pathway was distinctly activated after treated by PM2.5, which can be blocked by 2‐undecanone, accompanied by increasing Nrf2 and HO‐1 levels. To figure out the relationship between NF‐κB and Nrf2/HO‐1 pathways, we knocked down Nrf2 gene. NF‐κB pathway proteins and downstream inflammatory cytokines were significantly increased after treatment with PM2.5, while 2‐undecanone could decrease expression of these proteins. In conclusion, it is possible that 2‐undecanone can induce the expression of the antioxidant enzyme HO‐1 by activating Nrf2, thereby reducing NF‐κB pathway and inflammatory damage of mouse myocardium caused by PM2.5 exposure. [ABSTRACT FROM AUTHOR]

High-resolution differential surface plasmon resonance (SPR) with anodic stripping voltammetry (ASV) capability has been demonstrated for detecting heavy metal ions in water. Metal ions are electroplated onto the gold SPR sensing surface and are quantitatively detected by stripping voltammetry. Both the SPR angular shift and electrochemical current signal are recorded to identify the type and amount of the metal ions in water. The performance of the combined approach is further enhanced by a differential detection approach. The gold sensor surface is divided into a reference and a sensing area, and the difference in the SPR angles from the two areas is detected with a quadrant cell photodetector as a differential signal. Our system demonstrated quantitative detection of copper, lead, and mercury ions in water from part-per-million to sub-part-per-billion levels with good linearity.

The PrrAB two-component system (TCS) is essential for Mycobacterium tuberculosis viability. Previously, it was demonstrated that PrrA binds DNA in the absence of PrrB-mediated transphosphorylation and that non-cognate serine/threonine-kinases phosphorylate PrrA threonine-6 (T6). Therefore, we investigated the differential binding affinity and regulatory properties of the M. tuberculosis -derived wild-type PrrA, PrrA phosphomimetic (D58E, T6E), and PrrA phosphoablative (D58A, T6A) proteins with the prrA Mtb , dosR Mtb , and cydA Mtb genes. While we hypothesized greater DNA binding affinity and more pronounced regulation by PrrA phosphomimetic variants, recombinant, wild-type PrrA Mtb bound DNA with greatest affinity. Collectively, wild-type PrrA Mtb recombinant protein displayed the highest binding affinity to the dosR Mtb promoter (K D 3.46 ± 2.09 nM), followed by the prrA Mtb promoter (K D 9.00 ± 2.66 nM). To establish PrrA Mtb regulatory activity, we constructed M. smegmatis Δ prrAB Msmeg ::prrA Mtb strains with each of the PrrA Mtb variants and extrachromosomal prrA Mtb , dosR Mtb , and cyd A Mtb promoter-mCherry reporter fusions. Our findings showed that PrrA Mtb is autoregulatory and induces dosR Mtb expression only during in vitro, hypoxic growth. Combined expression of prrAB Mtb in M. smegmatis Δ prrAB significantly induced cydA Mtb promoter - mCherry expression. Our studies advanced the understanding of PrrA function and PrrAB phosphorylation-mediated regulatory mechanisms and control of mycobacterial dosR and cydA hypoxic and low-oxygen responsive genes. [Display omitted] Main Figure. Overview and highlight of biomolecular protein-DNA interactions between the PrrA Mtb WT protein and the prrA Mtb , dosR Mtb , and cydA Mtb promoters established by surface plasmon resonance. The PrrA Mtb WT protein rapidly and strongly binds the dosR Mtb and prrA Mtb promoters with binding affinity values in the low nanomolar range. [ABSTRACT FROM AUTHOR]

The strain-induced polarization in a piezoelectric semiconductor is an effective strategy to modulate its current transport. However, the piezoelectricity is degraded by the free charges, and the inevitable compromise of piezoelectricity and semiconductivity severely limits the material choice and device performance. We tackle this dilemma by investigating the polarization caused by broken translational symmetry of a material surface. The ubiquitous surface piezoelectricity of solid materials enables the strain-induced polarization change to control the electrical transport effectively in crystals without bulk piezoelectricity. The Schottky barrier is shown to prohibit the bulk charges from screening the surface polarization. The strain engineering of the barrier height leads to an exponential modulation of the current, and an unprecedented gauge factor of 3.10×108 and an on/off ratio of 2.53×105 are demonstrated. The outstanding tunability of current with the synergistic effect of the surface piezoelectricity and metal-semiconductor contact unlocks the device development from various materials. [Display omitted] • Strain-modulated electronics is realized with a gauge factor of 3.10×108 and an on/off ratio of 2.53×105. • The surface piezoelectricity of a semiconductor is positively correlated with its electrical conductivity. • The charge depletion layer prevents the bulk charges from annihilating the surface polarization. [ABSTRACT FROM AUTHOR]

• A dual-column distillation process is proposed for offshore nitrogen production. • Liquid nitrogen of high purity is realized under offshore conditions. • Distillation is more sensitive to tilting than swing. • Increasing swing period deteriorates distillation. Cryogenic distillation is widely acknowledged as the primary industrial method for producing liquid nitrogen of high purity. However, the distillation process is highly sensitive to tilting and swinging, which limits the application of cryogenic air separation in offshore infrastructures. This paper proposes a small-scale air separation process that incorporates a dual-column distillation to enhance distillation performance under offshore conditions. Experiments were conducted under standard (no-tilting and stationary), tilting, and swinging conditions. The results indicate that the proposed distillation plant can maintain nitrogen purity to a certain extent under offshore conditions. The product impurity (oxygen content) increased significantly as the tilting angles increased beyond 4° for horizontal titling and 3° for longitudinal titling, respectively. The distillation performance was less affected by the swing than the tilting. High-purity nitrogen could be produced when swing amplitude was within ±10° and swing period was between 6 s and 11 s. The results can provide engineering guidance for the design and installation of the columns of air-separation plants. [ABSTRACT FROM AUTHOR]

Phage display technology has been a powerful tool in peptide drug development. However, the supremacy of phage display-based peptide drug discovery is plagued by the follow-up process of peptides synthesis, which is costly and time consuming, but is necessary for the accurate measurement of binding kinetics in order to properly triage the best peptide leads during the affinity maturation stages. A sensitive technology is needed for directly measuring the binding kinetics of peptides on phages to reduce the time and cost of the entire process. Here, we show the capability of a charge-sensitive optical detection (CSOD) method for the direct quantification of binding kinetics of phage-displayed peptides to their target protein, using whole phages. We anticipate CSOD will contribute to streamline the process of phage display-based drug discovery. [ABSTRACT FROM AUTHOR]

Purpose: To generate and evaluate individualized post-therapeutic optical coherence tomography (OCT) images that could predict the short-term response of anti-vascular endothelial growth factor (VEGF) therapy for diabetic macular edema (DME) based on pre-therapeutic images using generative adversarial network (GAN). Methods: Real-world imaging data were collected at the Department of Ophthalmology, Qilu Hospital. A total of 561 pairs of pre-therapeutic and post-therapeutic OCT images of patients with DME were retrospectively included in the training set, 71 pre-therapeutic OCT images were included in the validation set, and their corresponding post-therapeutic OCT images were used to evaluate the synthetic images. A pix2pixHD method was adopted to predict post-therapeutic OCT images in DME patients that received anti-VEGF therapy. The quality and similarity of synthetic OCT images were evaluated independently by a screening experiment and an evaluation experiment. Results: The post-therapeutic OCT images generated by the GAN model based on big data were comparable to the actual images, and the response of edema resorption was also close to the ground truth. Most synthetic images (65/71) were difficult to differentiate from the actual OCT images by retinal specialists. The mean absolute error (MAE) of the central macular thickness (CMT) between the synthetic OCT images and the actual images was 24.51 ± 18.56 μm. Conclusions: The application of GAN can objectively demonstrate the individual short-term response of anti-VEGF therapy one month in advance based on OCT images with high accuracy, which could potentially help to improve treatment compliance of DME patients, identify patients who are not responding well to treatment and optimize the treatment program. [ABSTRACT FROM AUTHOR]

In this paper, a microstructure-dependent magneto-electro-elastic functionally graded porous (MEEFGP) beam model is proposed using a variational approach. To account for the microstructure effect, the extended modified couple stress theory is incorporated in the new model. In addition, the porosity variation of the two-phase beam model through the thickness direction is also considered. The new developed model is verified in terms of its correctness with a FEM model. Based on the equations of motion and boundary conditions derived by Hamilton's principle, the static bending and wave propagation behaviors of the new model are analytically determined. The results prove the existence of the microstructure effect and the magneto-electro-elastic multi-field coupling effect. There are significant differences between the new model and the classical model at the microscale. Moreover, the porosity also has an important influence on the mechanical properties of the new model. The results predicted by the new model can provide the theoretical basis for the design of microscale acoustic wave devices and micro-electro-mechanical systems. [ABSTRACT FROM AUTHOR]

Evanescent illumination has been widely used to detect single biological macromolecules because it can notably enhance light-analyte interaction. However, the current evanescent single-molecule detection system usually requires specially designed microspheres or nanomaterials. Here we show that single protein detection and imaging can be realized on a plain glass surface by imaging the interference between the evanescent lights scattered by the single proteins and by the natural roughness of the cover glass. This allows us to quantify the sizes of single proteins, characterize the protein–antibody interactions at the single-molecule level, and analyze the heterogeneity of single protein binding behaviors. In addition, owing to the exponential distribution of evanescent field intensity, the evanescent imaging system can track the analyte axial movement with high resolution, which can be used to analyze the DNA conformation changes, providing one solution for detecting small molecules, such as microRNA. This work demonstrates a label-free single protein imaging method with ordinary consumables and may pave a road for detecting small biological molecules. Single molecule detection based on evanescent illumination usually require specially designed nanomaterials. Here, the authors show that single molecule detection can be realised on a plain glass surface via interference between the evanescent lights scattered by molecules and the natural roughness of the glass. [ABSTRACT FROM AUTHOR]