Optical assembly of multi-particle arrays by opto-hydrodynamic binding of microparticles close to a one-dimensional chain of magnetic microparticles.

Two-dimensional materials possess a large number of interesting and important properties. Various methods have been developed to assemble two-dimensional aggregates. Assembly of colloidal particles can be achieved with laser-heating-induced thermal convective flow. In this paper, an opto-hydrodynamic binding method is proposed to assemble colloidal particles dispersed in a solution into multilayer structures. First, we use polystyrene (PS) microspheres to study the feasibility and characteristics of the assembly method. PS microspheres and monodispersed magnetic silica microspheres (SLEs) are dispersed in a solution to form a binary mixture system. Under the action of an external uniform magnetic field, SLEs in the solution form chains. An SLE chain is heated by a laser beam. Due to the photothermal effect, the SLE chain is heated to produce a thermal gradient, resulting in thermal convection. The thermal convection drives the PS beads to move toward the heated SLE chain and finally stably assemble into multilayer aggregates on both sides of the SLE chain. The laser power affects the speed and result of the assembly. When the laser power is constant, the degree of constraint of the PS microbeads in different layers is also different. At the same time, this method can also assemble the biological cells, and the spacing of different layers of cells can be changed by changing the electrolyte concentration of the solution. Our work provides an approach to assembling colloidal particles and cells, which has a potential application in the analysis of the collective dynamics of microparticles and microbes.

Plug-and-play DPC-based quantitative phase microscope.

Point-of-care testing (POCT) plays an increasingly important role in biomedical research and health care. Quantitative phase microscopes (QPMs) with good contrast, no invasion, no labeling, high speed and automation could be effectively applied for POCT. However, most QPMs are fixed on the optical platform with bulky size, lack of timeliness, which remained challenging in POCT solutions. In this paper, we proposed a plug-and-play QPM with multimode imaging based on the quantitative differential phase contrast (qDPC) method. The system employs a programmable LED array as the light source and uses the GPU to accelerate the calculation, which can realize multi-contrast imaging with six modes. Accurate phase measurement and real-time phase imaging are implemented by the proposed qDPC algorithms for quantitative phase targets and biomedical samples. A 3D electric control platform is designed for mechanical control of field of view and focusing without manual operations. The experimental results verify the robustness and high performance of the setup. Even a rookie could finish the POCT scheme for biomedical applications at the scene using the QPM with a compact size of 140 × 165 × 250 mm3.

Fixed-Time-Convergent Sliding Mode Control with Sliding Mode Observer for PMSM Speed Regulation.

This paper focuses on the speed control of a permanent magnet synchronous motor (PMSM) for electric drives with model uncertainties and external disturbances. Conventional sliding mode control (CSMC) can only converge asymptotically in the infinite domain and will cause unacceptable sliding mode chattering. To improve the performance of the PMSM speed loop in terms of response speed, tracking accuracy, and robustness, a hybrid control strategy for a fixed-time-convergent sliding mode controller (FSMC) with a fixed-time-convergent sliding mode observer (FSMO) is proposed for PMSM speed regulation using the fixed-time control theory. Firstly, the FSMC is proposed to improve the convergence speed and robustness of the speed loop, which can converge to the origin within a fixed time independent of the initial conditions. Then, the FSMO is used as a compensator to further enhance the robustness of the speed loop and attenuate sliding mode chattering. Finally, simulation and experimental results show that the proposed method can effectively improve the dynamic performance and robustness of the PMSM speed control system.

Total organic carbon measurements reveal major gaps in petrochemical emissions reporting.

Anthropogenic organic carbon emissions reporting has been largely limited to subsets of chemically speciated volatile organic compounds. However, new aircraft-based measurements revealed total gas-phase organic carbon emissions that exceed oil sands industry-reported values by 1900% to over 6300%, the bulk of which was due to unaccounted-for intermediate-volatility and semivolatile organic compounds. Measured facility-wide emissions represented approximately 1% of extracted petroleum, resulting in total organic carbon emissions equivalent to that from all other sources across Canada combined. These real-world observations demonstrate total organic carbon measurements as a means of detecting unknown or underreported carbon emissions regardless of chemical features. Because reporting gaps may include hazardous, reactive, or secondary air pollutants, fully constraining the impact of anthropogenic emissions necessitates routine, comprehensive total organic carbon monitoring as an inherent check on mass closure.

Measurement of red blood cell deformability during morphological changes using rotating-glass-plate-based scanning optical tweezers.

It is important to measure the deformability of red blood cells (RBCs) before transfusion, which is a key factor in the gas transport ability of RBCs and changes during storage of RBCs in vitro. Moreover, the morphology of RBCs also changes during storage. It is proposed that the change in morphology is related to the change in deformability. However, the efficiency of typical methods that use particles as handles is low, especially in the deformability measurement of echinocyte and spherocytes. Therefore, the deformability of RBCs with different morphologies is hard to be measured and compared in the same experiment. In this study, we developed a cost-effective and efficient rotating-glass-plate-based scanning optical tweezers device for the measurement of deformability of RBCs. The performance of this device was evaluated, and the deformability of three types of RBCs was measured using this device. Our results clearly show that the change of erythrocyte morphology from discocyte to echinocyte and spherocyte during storage in vitro is accompanied by a decrease in deformability.

Deformability of mouse erythrocytes in different diluents measured using optical tweezers.

Optical tweezers are widely used to measure the mechanical properties of erythrocytes, which is crucial to the study of pathology and clinical diagnosis of disease. During the measurement, the blood sample is diluted and suspended in an exogenous physiological fluid, which may affect the elastic properties of the cells in vitro. Here, we investigate the effect of different diluents on the elastic properties of mouse erythrocytes by quantitatively evaluating their elastic constants using optical tweezers. The diluents are plasma extracted from mouse blood, veterinary blood diluent (V-52D), Dulbecco's modified Eagle's medium (DMEM), phosphate-buffered saline (PBS), and normal saline (NS). To create an environment that closely resembles in vivo conditions, the experiment is performed at 36.5 °C. The results show that the spring constant of mouse erythrocytes in plasma is 6.23 ± 0.41 µN m-1. The elasticity of mouse erythrocytes in V-52D and DMEM is 8.21 ± 0.91 and 6.95 ± 0.85 µN m-1, which are higher than that in plasma extracted from blood, whereas, the elasticity in PBS and NS is 4.23 ± 0.85 and 4.68 ± 0.79 µN m-1, which are less than that in plasma extracted from blood. At last, we observe the size and circularity of erythrocytes in different diluents, and consider that the erythrocyte diameter and circularity may affect cell deformability. Our results provide a reference of the diluent choice for measuring the mechanical properties of erythrocytes in vitro.

Ambient Pressure Drying of Freeze-Cast Ceramics from Aqueous Suspension.

Freeze-casting has been wildly exploited to construct porous ceramics but usually requires costly and demanding freeze-drying (high vacuum, size limit, and supercooled chamber), which can be avoided by the ambient pressure drying (APD) technique. However, applying APD to freeze-cast ceramic based on an aqueous suspension is still challenging due to inert surface chemistry. Herein, a modified APD strategy is developed to improve the drying process of freeze-cast ceramics by exploiting the simultaneous ice etching, ionic cross-linking, and solvent exchange under mild conditions (-10-0 °C, ambient pressure). This versatile strategy is applicable to various ceramic species, metal ions, and freezing techniques. The incorporated metal ions not only enhance liquid-phase sintering, producing ceramics with higher density and mechanical properties than freeze-cast counterparts, but also render customizable coloration and antibacterial property. The cost-/time-efficient APD is promising for mass production and even successive production of large-size freeze-cast ceramics that exceed the size of commercial freeze-dryers.

Optical trapping of microparticles with two tilted-focused laser beams.

We present an optical method for the manipulation of microparticles using two tilted-focused beams. First, the action on the microparticles is studied with a single tilted-focused beam. The beam is used to drive the directional motion of a dielectric particle. When the optical scattering force is larger than the optical gradient force, the particle is pushed to the tilted side of the optical axis by the optical force. Second, two tilted-focused beams with the same power and complementary tilt angles are used to assemble an optical trap. The trap can be used to realize the optical trapping of the dielectric particles and opto-thermal trapping of the light absorbing particles. The trapping mechanism is the balance of the forces exerted on the particles, including the optical scattering force, optical gradient force, gravity, and thermal gradient force. The trap center is away from the focal spots, which effectively prevents the laser beam from being focused on the trapped object.

Compensation Method for the Nonlinear Characteristics with Starting Error of a Piezoelectric Actuator in Open-Loop Controls Based on the DSPI Model.

Nanopositioning stages with piezoelectric actuators have been widely used in fields such as precision mechanical engineering, but the nonlinear start-up accuracy problem under open-loop control has still not been solved, and more errors will accumulate, especially under open-loop control. This paper first analyzes the causes of the starting errors from both the physical properties of materials and voltages: the starting errors are affected by the material properties of piezoelectric ceramics, and the magnitude of the voltage determines the magnitude of the starting errors. Then, this paper adopts an image-only model of the data separated by a Prandtl-Ishlinskii model (DSPI) based on the classical Prandtl-Ishlinskii model (CPI), which can improve the positioning accuracy of the nanopositioning platform after separating the data based on the start-up error characteristics. This model can improve the positioning accuracy of the nanopositioning platform while solving the problem of nonlinear start-up errors under open-loop control. Finally, the DSPI inverse model is used for the feedforward compensation control of the platform, and the experimental results show that the DSPI model can solve the nonlinear start-up error problem existing under open-loop control. The DSPI model not only has higher modeling accuracy than the CPI model but also has better performance in terms of compensation results. The DSPI model improves the localization accuracy by 99.427% compared to the CPI model. When compared with another improved model, the localization accuracy is improved by 92.763%.

Synthesis and Insecticidal Activity Study of Azidopyridryl Containing Dichlorolpropene Ether Derivatives.

Pyridalyl, as a novel insecticide with an unknown mode of action, has shown excellent control efficacy against lepidopterous larvae and thrips. Previous modifications of this compound have mostly focused on the pyridine moiety, with limited information available about modifications to other parts of pyridalyl. In this paper, we report the synthesis and insecticidal activity of a series of azidopyridryl-containing dichlorolpropene ether derivatives, based on modifications to the middle alkyl chain of pyridalyl. Screening results for insecticidal activity indicate that our synthesized compounds show moderate to high activities at the tested concentrations against P. xylostella. Particularly, compound III-10 exhibits a LC50 value of 0.831 mg L-1, compared to the LC50 value of pyridalyl at 2.021 mg L-1. Furthermore, compound III-10 also displays a relatively broad insecticidal spectrum against Lepidoptera pests M. separata, C. suppressalis, O. nubilalis, and C. medinalis. Finally, in field trials, III-10 demonstrates better control efficiency against Chilo suppressalis compared to pyridalyl. Overall, our findings suggest that the modification of the middle alkyl chain of pyridalyl may be a promising approach for developing insecticides with improved efficacy.

Salvianolic acids from Salvia miltiorrhiza Bunge and their anti-inflammatory effects through the activation of α7nAchR signaling.

ETHNOPHARMACOLOGICAL RELEVANCE: Cardiovascular disease (CVD) is a serious disease with a high incidence rate and mortality. Inflammation is closely related to the occurrence of CVDs. As an essential medicine of promoting blood circulation and removing blood stasis in China, Salvia miltiorrhiza Bunge (Danshen) is widely used to treat CVDs due to its anti-inflammatory and cardiovascular protective effects. Salvianolic acids are the most abundant component in the water extract of S. miltiorrhiza, which has a significant effect on the treatment of CVDs. However, due to the complex composition of salvianolic acids, the active molecules and their underlying mechanisms have not been fully explored. AIM OF THIS STUDY: The present study aims to isolate and identify salvianolic acids from Danshen with anti-inflammatory activity and explore the potential mechanisms of isolates. METHODS: The structures of isolated salvianolic acids were elucidated by UV, IR, NMR, MS and electronic circular dichroism (ECD) calculations. Then anti-inflammatory activities of isolates were screened out by the zebrafish inflammation models. The most active compound was further used to explore the anti-inflammatory mechanisms on LPS-stimulated RAW 264.7 cells. The key inflammatory cytokines IL-6 and TNF-α were measured by enzyme-linked immunosorbent assay (ELISA). The protein expression levels of STAT3, p-STAT3 (Tyr705), NF-κB p65, IκBα, p-IκBα (Ser32) and α7nAchR were determined by Western blotting. The nuclear translocation of p-STAT3 (Tyr705) and NF-κB p65 was evaluated by immunofluorescence assays. Finally, the in vivo anti-inflammatory mechanisms were investigated by observation of neutrophil migration, H&E staining, survival analysis and quantitative PCR (Q-PCR) in LPS-microinjected zebrafish. RESULTS: Two new and four known compounds were isolated from Danshen. Among them, isosalvianolic acid A-1 (C1) and ethyl lithospermate (C5) inhibited neutrophil migrations in three zebrafish inflammation models and C1 with the best activities decreased the secretion of IL-6 and TNF-α and inhibited the expression level of p-IκBα (Ser32) in LPS stimulated RAW 264.7 cells. In addition, C1 also reduced the nuclear translocation of NF-κB p65 and p-STAT3 (Tyr705). Moreover, C1 significantly upregulated the protein expression of α7nAchR, and the knockdown of α7nAchR counteracted the effects of C1 on the production of IL-6 and TNF-α and the expression levels of p-STAT3 (Tyr705), NF-κB p65 and p-IκBα (Ser32). In vivo experiments, C1 decreased the migration and infiltration of inflammatory cells, increased the survival ratio and inhibited the mRNA level of IL-6, TNF-α, STAT3, NF-κB and IκBα in LPS-microinjected zebrafish. CONCLUSION: Two new and four known compounds were isolated from Danshen. Among them, C1 exerted anti-inflammatory activities by activating α7nAchR signaling and subsequently inhibiting STAT3 and NF-κB pathways. This study provided evidence for the clinical application of Danshen and contributed to the development of C1 as a novel in the treatment of cardiovascular disease.

Identification of neoantigens and immunological subtypes in clear cell renal cell carcinoma for mRNA vaccine development and patient selection.

Clear cell renal cell carcinoma (ccRCC) is a common urological malignancy with diverse histological types. This study aimed to detect neoantigens in ccRCC to develop mRNA vaccines and distinguish between ccRCC immunological subtypes for construction of an immune landscape to select patients suitable for vaccination. Using The Cancer Genome Atlas SpliceSeq database, The Cancer Genome Atlas, and the International Cancer Genome Consortium cohorts, we comprehensively analysed potential tumour antigens of ccRCC associated with aberrant alternative splicing, somatic mutation, nonsense-mediated mRNA decay factors, antigen-presenting cells, and overall survival. Immune subtypes (C1/C2) and nine immune gene modules of ccRCC were identified by consistency clustering and weighted correlation network analysis. The immune landscape as well as molecular and cellular characteristics of immunotypes were assessed. Rho-guanine nucleotide exchange factor 3 (ARHGEF3) was identified as a new ccRCC antigen for development of an mRNA vaccine. A higher tumour mutation burden, differential expression of immune checkpoints, and immunogenic cell death were observed in cases with the C2 immunotype. Cellular characteristics increased the complexity of the immune environment, and worse outcomes were observed in ccRCC cases with the C2 immunotype. We constructed the immune landscape for selecting patients with the C2 immunotype suitable for vaccination.

Relationships of Low Serum Levels of Interleukin-10 With Poststroke Anxiety and Cognitive Impairment in Patients With Clinical Acute Stroke.

BACKGROUND AND PURPOSE: The relationships among interleukin (IL)-10 levels, anxiety, and cognitive status after stroke remain controversial. We aimed to determine the associations of serum IL-10 levels with poststroke anxiety (PSA) and poststroke cognitive impairment (PSCI). METHODS: We recruited 350 patients with stroke, of whom only 151 completed a 1-month follow-up assessment. The Mini Mental State Examination (MMSE) and Hamilton Anxiety Scale (HAMA) were used to assess the cognitive status and anxiety, respectively. Serum IL-10 levels were measured within 24 hours of admission. RESULTS: IL-10 levels were significantly lower in the PSA group than in the non-PSA group, and they were negatively associated with HAMA scores (r=-0.371, p<0.001). After adjusting for all potential confounders, IL-10 levels remained an independent predictor of PSA (odds ratio=0.471, 95% confidence interval=0.237-0.936, p=0.032). IL-10 levels were strongly correlated with behavior during interviews, psychic anxiety, and somatic anxiety. Patients without PSCI had higher IL-10 levels were higher in non-PSCI patients than in PSCI patients, and they were positively associated with MMSE scores in the bivariate correlation analysis (r=0.169, p=0.038), and also with memory capacity, naming ability, and copying capacity. However, IL-10 did not predict PSCI in the univariable or multivariable logistic regression. CONCLUSIONS: Low IL-10 levels were associated with increased risks of PSA and PSCI at a 1-month follow-up after stroke. Serum IL-10 levels may therefore be helpful in predicting PSA.

Aircraft and satellite observations reveal historical gap between top-down and bottom-up CO2 emissions from Canadian oil sands.

Measurement-based estimates of greenhouse gas (GHG) emissions from complex industrial operations are challenging to obtain, but serve as an important, independent check on inventory-reported emissions. Such top-down estimates, while important for oil and gas (O&G) emissions globally, are particularly relevant for Canadian oil sands (OS) operations, which represent the largest O&G contributor to national GHG emissions. We present a multifaceted top-down approach for estimating CO2 emissions that combines aircraft-measured CO2/NOx emission ratios (ERs) with inventory and satellite-derived NOx emissions from Ozone Monitoring Instrument (OMI) and TROPOspheric Ozone Monitoring Instrument (TROPOMI) and apply it to the Athabasca Oil Sands Region (AOSR) in Alberta, Canada. Historical CO2 emissions were reconstructed for the surface mining region, and average top-down estimates were found to be >65% higher than facility-reported, bottom-up estimates from 2005 to 2020. Higher top-down vs. bottom-up emissions estimates were also consistently obtained for individual surface mining and in situ extraction facilities, which represent a growing category of energy-intensive OS operations. Although the magnitudes of the measured discrepancies vary between facilities, they combine such that the observed reporting gap for total AOSR emissions is ≥(31 ± 8) Mt for each of the last 3 years (2018-2020). This potential underestimation is large and broadly highlights the importance of continued review and refinement of bottom-up estimation methodologies and inventories. The ER method herein offers a powerful approach for upscaling measured facility-level or regional fossil fuel CO2 emissions by taking advantage of satellite remote sensing observations.

Research review on the pollution of antibiotic resistance genes in livestock and poultry farming environments.

Increasingly serious pollution of antibiotic resistance genes (ARGs) caused by the abuse of antibiotics in livestock and poultry industry has raised worldwide concerns. ARGs could spread among various farming environmental media through adsorption, desorption, migration, and also could transfer into human gut microbiome by hori-zontal gene transfer (HGT), posing potential threats to public health. However, the comprehensive review on the pollution patterns, environmental behaviors, and control techniques of ARGs in livestock and poultry environments in view of One Health is still inadequate, resulting in the difficulties in effectively assessing ARGs transmission risk and developing the efficient control strategies. Here, we analyzed the pollution characteristics of typical ARGs in various countries, regions, livestock species, and environmental media, reviewed the critical environmental fate and influencing factors, control strategies, and the shortcomings of current researches about ARGs in the livestock and poultry farming industry combined with One Health philosophy. In particular, we addressed the importance and urgency of identifying the distribution characteristics and environmental process mechanisms of ARGs, and developing green and efficient ARG control means in livestock farming environments. We further proposed gaps and prospects for the future research. It would provide theoretical basis for the research on health risk assessment and technology exploitation of alleviating ARG pollution in livestock farming environment.

MOF-Derived Ultrathin NiCo-S Nanosheet Hybrid Array Electrodes Prepared on Nickel Foam for High-Performance Supercapacitors.

At present, binary bimetallic sulfides are widely studied in supercapacitors due to their high conductivity and excellent specific capacitance (SC). In this article, NiCo-S nanostructured hybrid electrode materials were prepared on nickel foam (NF) by using a binary metal-organic skeleton as the sacrificial template via a two-step hydrothermal method. Comparative analysis was carried out with Ni-S and Co-S in situ on NF to verify the excellent electrochemical performance of bimetallic sulfide as an electrode material for supercapacitors. NiCo-S/NF exhibited an SC of 2081 F∙g-1 at 1 A∙g-1, significantly superior to Ni-S/NF (1520.8 F∙g-1 at 1 A∙g-1) and Co-S/NF (1427 F∙g-1 at 1 A∙g-1). In addition, the material demonstrated better rate performance and cycle stability, with a specific capacity retention rate of 58% at 10 A∙g-1 than at 1 A∙g-1, and 75.7% of capacity was retained after 5000 cycles. The hybrid supercapacitor assembled by NiCo-S//AC exhibited a high energy density of 25.58 Wh∙kg-1 at a power density of 400 W∙kg-1.

An opto-thermal approach for assembling yeast cells by laser heating of a trapped light absorbing particle.

Cell assembly has important applications in biomedical research, which can be achieved with laser-heating induced thermal convective flow. In this paper, an opto-thermal approach is developed to assemble the yeast cells dispersed in solution. At first, polystyrene (PS) microbeads are used instead of cells to explore the method of microparticle assembly. The PS microbeads and light absorbing particles (APs) are dispersed in solution and form a binary mixture system. Optical tweezers are used to trap an AP at the substrate glass of the sample cell. Due to the optothermal effect, the trapped AP is heated and a thermal gradient is generated, which induces a thermal convective flow. The convective flow drives the microbeads moving toward and assembling around the trapped AP. Then, the method is used to assemble the yeast cells. The results show that the initial concentration ratio of yeast cells to APs affects the eventual assembly pattern. The binary microparticles with different initial concentration ratios assemble into aggregates with different area ratios. The experiment and simulation results show that the dominant factor in the area ratio of yeast cells in the binary aggregate is the velocity ratio of the yeast cells to the APs. Our work provides an approach to assemble the cells, which has a potential application in the analysis of microbes.

A newly developed Lagrangian chemical transport scheme: Part 1. Simulation of a boreal forest fire plume.

Forest fire research over the last several decades has improved the understanding of fire emissions and impacts. Nevertheless, the evolution of forest fire plumes remains poorly quantified and understood. Here, a Lagrangian chemical transport model, the Forward Atmospheric Stochastic Transport model coupled with the Master Chemical Mechanism (FAST-MCM), has been developed to simulate the transport and chemical transformations of plumes from a boreal forest fire over several hours since their emission. The model results for NOx (NO and NO2), O3, HONO, HNO3, pNO3 and 70 VOC species are compared with airborne in-situ measurements within plume centers and their surrounding portions during the transport. Comparisons between simulation results and measurements show that the FAST-MCM model can properly reproduce the physical and chemical evolution of forest fire plumes. The results indicate that the model can be an important tool used to aid the understanding of the downwind impacts of forest fire plumes.

Biomimetic Gradient Bouligand Structure Enhances Impact Resistance of Ceramic-Polymer Composites.

Biological materials relied on multiple synergistic structural design elements typically exhibit excellent comprehensive mechanical properties. Hierarchical incorporation of different biostructural elements into a single artificial material is a promising approach to enhance mechanical properties, but remains challenging. Herein, a biomimetic structural design strategy is proposed by coupling gradient structure with twisted plywood Bouligand structure, attempting to improve the impact resistance of ceramic-polymer composites. Via robocasting and sintering, kaolin ceramic filaments reinforced by coaxially aligned alumina nanoplatelets are arranged into Bouligand structure with a gradual transition in filament spacing along the thickness direction. After the following polymer infiltration, biomimetic ceramic-polymer composites with a gradient Bouligand (GB) structure are eventually fabricated. Experimental investigations reveal that the incorporation of gradient structure into Bouligand structure improves both the peak force and total energy absorption of the obtained ceramic-polymer composites. Computational modeling further suggests the substantial improvement in impact resistance by adopting GB structure, and clarifies the underlying deformation behavior of the biomimetic GB structured composites under impact. This biomimetic design strategy may provide valuable insights for developing lightweight and impact-resistant structural materials in the future.