On-Demand Transport Bubbles Adhering to Noncontiguous Patterned Superhydrophobic Surfaces Using a Superhydrophobic Tweezer.

Bubble transportation and related flotation are ubiquitous phenomena in nature and industry. Various surfaces with distinct morphologies and specific wettability properties have been engineered by organisms in nature and by humans to facilitate the targeted movement of bubbles. However, existing methods predominantly rely on continuous surfaces, limiting the ability of bubbles to deviate from their path before reaching their intended destination. Therefore, directional transportation of bubbles using noncontiguous surfaces still remains a significant challenge. Inspired by water spiders' ability to capture bubbles underwater using their hydrophobic surface for survival, we propose a novel transport strategy that utilizes patterned superhydrophobic surfaces (PSHSs) and a superhydrophobic tweezer. This strategy is implemented by switching between the hood mode and puncture mode of the moving three-phase contact lines to load and unload the bubble. To quantitatively evaluate the loss ratio of the bubble during transportation, a simple and exquisite bubble-weighing apparatus is devised. Our findings indicate that circular PSHSs demonstrate superior bubble adhesion and achieve the highest bubble transport ratio of 95.1%. In order to validate the promising application of this novel method, we employ the computer numerical control (CNC) technology to facilitate the autonomous loading and precise transportation of underwater bubbles, as well as the blending and ionization of combustible gas bubbles with air bubbles at different volume ratios.

Down-conversion and frequency spectrum convolution of the broadband signal based on active mode-locking technology.

A multifunction processor for a broadband signal based on the active mode-locking optoelectronic oscillator (OEO) is proposed and experimentally demonstrated. The central frequency down-conversion and frequency spectrum convolution of the target broadband signal (TBS) are realized by just tuning the wavelength of the optical carrier or by the time domain product, respectively. To achieve the central frequency down-conversion of the TBS, an optical tunable delay line (OTDL) is adopted to match the delay time of the OEO loop with the repetition period of the TBS. Then the spectrum convolution of the TBS is produced by just injecting a lower frequency signal consistent with the free spectral range (FSR) of the OEO loop. Moreover, the frequency convolution repetition is also greatly increased by harmonic mode-locking injection. The equivalent bandwidth of the TBS is enlarged by ∼50 times, benefiting from the frequency convolution. The central frequency conversion flexibility and the bandwidth compatibility are also discussed in detail. This work provides a multifunction processor system and may have potential usage in multifunctional integrated radar systems.

LC-MS/MS method for quick detection of vonoprazan fumarate in human plasma: Development, validation and its application to a bioequivalence study.

A liquid chromatography-tandem mass spectrometry method with vonoprazan fumarate-d4 as a stable isotope-labeled internal standard was developed and validated aiming at quantification of vonoprazan fumarate in human plasma for a bioequivalence study. Chromatographic separation was achieved by acetonitrile one-step protein precipitation using a gradient elution of 0.1% formic acid aqueous solution and acetonitrile with a run time of 3.65 min. Detection was carried out on a tandem mass spectrometer in multiple reaction monitoring mode via a positive electrospray ionization interface. The multiple reaction monitoring mode of precursor-product ion transitions for vonoprazan fumarate and vonoprazan fumarate-d4 were m/z 346.0 → 315.1 and 350.0 → 316.0, respectively. The linear range was 0.150-60.000 ng/ml. This method was fully validated with acceptable results in terms of selectivity, carryover, lower limit of quantification, calibration curve, accuracy, precision, dilution effect, matrix effect, stability, recovery and incurred sample reanalysis. A successful application of this method was realized in the bioequivalence study of vonoprazan fumarate tablet (20 mg) among healthy Chinese volunteers.

Taking full advantage of 'low-quality' datasets in watershed modeling and management: From a perspective of parameter calibration.

The quality of calibration datasets is critical for establishing well-calibrated models for reliable decision-making support. However, the analysis of the influence of calibration dataset quality and the discussion on how to use flawed and/or incomplete datasets are still far from sufficient. An evaluation framework for the impact of model calibration data on parameter identifiability, sensitivity, and uncertainty (ISU) was established. Three quantitative and normalized indicators were designed to describe the magnitude of ISU. With the case study of the upper Daqing River watershed, China and the model SWAT (Soil and Water Assessment Tool), one ideal dataset without quality flaws and 79 datasets with different types of flaws including observation error, low monitoring frequency, short data duration and low data resolution were evaluated. The result showed that 4 of 13 parameters that control canopy, groundwater and channel processes have higher ISU values, indicating the high identifiability, high sensitivity, and low uncertainty. The largest gap of parameter ISU between dataset with quality flaw and ideal dataset was 0.61 due to short data duration, while the smallest gap was -0.28 due to low monitoring data frequency. Although some defective datasets caused unacceptable calibration results and model output, some defective datasets can still be valuable for model calibration which depends on the hydrological processes of interest when applying the model. Equivalent calibration results were yielded by the datasets with similar statistical properties. When using datasets with traditional defective issues for calibration, a new step checking the consistency among decision goal, representative system process, determinative parameters and calibration datasets is suggested. Practices including process-related data selection, dataset regrouping and risk self-reporting when using low-quality datasets are encouraged to increase the reliability of model-based watershed management.

Research progress on natural preservatives of meat and meat products: classifications, mechanisms and applications.

Meat and meat products are highly susceptible to contamination by microorganisms and foodborne pathogens, which cause serious economic losses and health hazards. The large consumption and waste of meat and meat products means that there is a need for safe and effective preservation methods. Furthermore, toxicological aspects of chemical preservation techniques related to major health problems have sparked controversies and have prompted consumers and producers to turn to natural preservatives. Consequently, natural preservatives are being increasingly used to ensure the safety and quality of meat products as a result of customer preferences and biological efficacy. However, information on the current status of these preservatives is scattered and a comprehensive review is lacking. Here, we review current knowledge on the classification, mechanisms of natural preservatives and their applications in the preservation of meat and meat products, and also discuss the potential of natural preservatives to improve the safety of meat and meat products. The current status and the current research gaps in the extraction, application and controlled-release of natural antibacterial agents for meat preservation are also discussed in detail. This review may be useful to the development of efficient food preservation techniques in the meat industry. © 2024 Society of Chemical Industry.

Spontaneous Rising of a Whirling-Swimmer Driven by a Bubble.

The wind-dispersed seeds can rotate and fall like small vehicles with the help of the wind to obtain a longer propagation distance. Inspired by this, we propose a novel bubble-driven three-bladed whirling-swimmer (WS) to travel in the fluid as a vehicle. Four types of WSs with blade folding angles (φ) ranging from 10 to 60° were designed, and their swimming performance was evaluated. Regardless of the WS shape, the velocity increases linearly with φ, while the angular frequency exhibits an asymptotic value. Further, both the St and rotational energy of the WS peak at 20° ≤ φ ≤ 30° for different WS shapes as well as the vertical force and the hydrodynamic torque were solved from a proposed mechanics model. This folding angle range is unexpectedly consistent with the coning angle during maple samaras' stable falling. The WS lift and drag forces greatly depend on the interaction between the leading-edge vortex and the hub vortex. The results showed that the WS-IV seems to have the highest performance. Our work may shed new light on developing unpowered wireless swimmers of high swimming performance to provide a new way for underwater information collection, information transmission, and enhanced mixing.

Glucometer-based biosensor for the determination of ractopamine in animal-derived foods using rolling circle amplification.

Screening for persistent organic pollutants (POPs) in food is a complex and challenging process, as POPs can be present in very low levels and can be difficult to detect. Herein, we developed an ultrasensitive biosensor based on a rolling circle amplification (RCA) platform using a glucometer to determine POP. The biosensor was constructed using gold nanoparticle probes modified with antibodies and dozens of primers, magnetic microparticle probes conjugated with haptens, and targets. After competition, RCA reactions are triggered, numerous RCA products hybridize with the ssDNA-invertase, and the target is successfully transformed into glucose. Using ractopamine as a model analyte, this strategy obtained a linear detection range of 0.038-5.00 ng mL-1 and a detection limit of 0.0158 ng mL-1, which was preliminarily verified by screening in real samples. Compared with conventional immunoassays, this biosensor utilizes the high efficiency of RCA and the portable properties of a glucometer, which effectively improves the sensitivity and simplifies the procedures using magnetic separation technology. Moreover, it has been successfully applied to ractopamine determination in animal-derived foods, revealing its potential as a promising tool for POP screening.

Energy-Efficient Unmanned Aerial Vehicle-Aided Visible Light Communication with an Angle Diversity Transmitter for Joint Emergency Illumination and Communication.

Unmanned aerial vehicle-aided visible light communication (UAV-VLC) can be used to realize joint emergency illumination and communication, but the endurance of UAV is a key limiting factor. In order to overcome this limitation, this paper proposes the use of an angle diversity transmitter (ADT) to enhance the energy efficiency of the UAV-VLC system. The ADT is designed with one bottom LED and several evenly distributed inclined side LEDs. By jointly optimizing the inclination angle of the side LEDs in the ADT and the height of the hovering UAV, the study aims to minimize the power consumption of the UAV-VLC system while satisfying the requirements of both illumination and communication. Simulation results show that the energy efficiency of the UAV-VLC system can be greatly enhanced by applying the optimized ADT. Moreover, the energy efficiency enhancement is much more significant when the LEDs in the ADT have a smaller divergence angle, or more side LEDs are configured in the ADT. More specifically, a 50.9% energy efficiency improvement can be achieved by using the optimized ADT in comparison to the conventional non-angle diversity transmitter (NADT).

The reducibility and oxidation states of oxide-supported rhenium: experimental and theoretical investigations.

The activity and stability of supported metal catalysts, which exhibit high efficiency and activity, are significantly influenced by the interactions between the metal and the support, that is, metal-support interactions (MSIs). Here, we report an investigation of the MSIs between supported rhenium (Re) and oxide supports such as TiO2, SiO2, Al2O3, MgO, V2O5, and ZrO2 using experimental and computational approaches. The reducibility of the Re species was found to strongly depend on the oxide support. Experimental studies including temperature-programmed reduction by H2 as well as Re L3- and L1-edge X-ray absorption near edge structure (XANES) analysis revealed that the valency of the Re species started to decrease upon H2 reduction in the 200-400 °C range, except for Re on MgO, where the shift occurred at temperatures above 500 °C. The dependence of the Re L3- and L1-edge XANES spectra of the oxide-supported Re catalysts on the size of Re was also examined.

Sulforaphane activates anti-inflammatory microglia, modulating stress resilience associated with BDNF transcription.

Sulforaphane (SFN) is an organic isothiocyanate and an NF-E2-related factor-2 (Nrf2) inducer that exerts prophylactic effects on depression-like behavior in mice. However, the underlying mechanisms remain poorly understood. Brain-derived neurotrophic factor (BDNF), a neurotrophin, is widely accepted for its antidepressant effects and role in stress resilience. Here, we show that SFN confers stress resilience via BDNF upregulation and changes in abnormal dendritic spine morphology in stressed mice, which is accompanied by rectifying the irregular levels of inflammatory cytokines. Mechanistic studies demonstrated that SFN activated Nrf2 to promote BDNF transcription by binding to the exon I promoter, which is associated with increased Nrf2, and decreased methyl-CpG binding protein-2 (MeCP2), a transcriptional suppressor of BDNF, in BV2 microglial cells. Furthermore, SFN inhibited the pro-inflammatory phenotype and activated the anti-inflammatory phenotype of microglia, which was associated with increased Nrf2 and decreased MeCP2 expression in microglia of stressed mice. Hence, our findings support that Nrf2 induces BDNF transcription via upregulation of Nrf2 and downregulation of MeCP2 in microglia, which is associated with changes in the morphology of damaged dendritic spines in stressed mice. Meanwhile, the data presented here provide evidence for the application of SFN as a candidate for the prevention and intervention of depression.

Investigating the sub-daily dynamics of cyanobacterial blooms by coupling high-frequency time-series remote sensing with hydro-ecological modelling.

Cyanobacterial Harmful Algal Blooms (CyanoHABs) are a health-threatening and increasingly prevalent environmental issue at both regional and global levels. An improved understanding of the short-term dynamics of CyanoHABs is required to better capture their spatial pattern and temporal evolution. However, the heterogeneous and dynamic nature of CyanoHABs, and the interacting factors and processes that drive them, make interpreting and predicting the blooms a very challenging task. In this paper, we used an integrative approach that combines high-frequency time-series remote sensing with hydro-ecological modelling, to reproduce and investigate the sub-daily dynamics of CyanoHABs in Taihu Lake. Results show that the distribution of CyanoHABs is highly patchy and dynamic without intensive wind-induced circulation and turbulence, which suggests that the dynamic pattern may be largely caused by the migratory behavior of cyanobacteria. The hydro-ecological model well reproduced the observed pattern and trend, and the average of Root Mean Square Error (RMSE) and coefficient of determination (R2) were 9.82 µg/L and 0.52, respectively. Results from sensitivity analysis suggest that photosynthesis rate and respiration rate are two most influential model parameters. Conclusively, there is a lack of adequate representation of physiological processes in currently used modelling framework, thereby suggesting the need for microscale modelling for future modelling exercises of CyanoHABs.

DFT-spread OFDM with quadrature index modulation for practical VLC systems.

In this paper, we for the first time propose and investigate a novel discrete Fourier transform-spread-orthogonal frequency division multiplexing with quadrature index modulation (DFT-S-OFDM-QIM) scheme for practical visible light communication (VLC) systems. By performing subcarrier index modulation on both the in-phase and quadrature components of each subcarrier, OFDM-QIM achieves a higher spectral efficiency than conventional OFDM with index modulation (OFDM-IM). Moreover, the peak-to-average power ratio (PAPR) of OFDM-QIM can be substantially reduced by applying DFT spreading, and hence DFT-S-OFDM-QIM exhibits high tolerance against light-emitting diode (LED) nonlinearity. The superiority of the proposed DFT-S-OFDM-QIM scheme over other benchmark schemes has been successfully verified by both simulation and experimental results.

Microwave photonic radar system with ultra-flexible frequency-domain tunability.

Both effective detection demand against diversified development of flight targets and remote sensing providing identifiable and fine target information all call for microwave radar system with flexible and ultra-wideband frequency-domain ability to provide more high-resolution and multi-source information. A microwave photonic radar system with theoretically full-band and ultra-wideband working ability is presented and experimentally demonstrated. An optical frequency operation module is employed in the transmitter to break the frequency-domain limitation on the emitted radar signal, while two types of optical mixing structures are switched to provide the ability to receive target echoes at any frequency band. In the experiments, high-SNR optical frequency operation and subsequent waveform generation at each normal radar band, that is from HF to Ka, are carried out. Good linearity and coherence of the generated waveforms are also demonstrated. Then, multi-band system-level detection experiments are completed to show the full-band working ability. Centimeter-scale or even sub-centimeter-scale resolution are realized at different bands, which identifies the proposed system can handle target detection with flexible performance and support acquiring rich target information at different frequency bands in future.

Quantitative analysis of economic and environmental benefits for land fallowing policy in the Beijing-Tianjin-Hebei region.

The Beijing-Tianjin-Hebei region (BTH region) is a major crop-producing region of China suffering from environment deterioration. Land fallowing policy is widely used as the solution of agriculture-related environment pollution, while it is difficult to derive a quantitative basis for policy-making. An indicator system was established to quantitatively analyse economic and environmental benefits of land fallow policies in the BTH region. The system consisted of 8 indicators to describe the water, air and economic influences caused by land fallowing policy such as the amount of nutrient discharged, the emission of PM2.5-related and greenhouse gas, and the input and output of agriculture production. SWAT (Soil and Water Assessment Tool) and IAP-N (Improving Anthropogenic Practices of managing reactive Nitrogen) models were used to quantify environmental indicators. Five scenarios with different planting patterns and fallow intensities were simulated for five years with different hydrological conditions. It is found that the influence of policy on water environment is highly sensitive to hydrological conditions, while the influence on air environment and economy are more affected by different policy settings in scenarios. The marginal utilities of the fallowed area are indicator-dependent. Planting alternative crops can decrease production costs and keep crop yields, while may also cause atmospheric environmental pollution if the crops have nitrogen fixing ability. Indicators also have spatial and temporal heterogeneity under different planting patterns and fallow intensities. A policy evaluation and associated uncertainty analysis is essential for effective implementation. The analysis framework established could support decision-making in regions facing agri-environmental problems.

Optimizing the soil conservation service curve number model by accounting for rainfall characteristics: a case study of surface water sources in Beijing.

The upper catchment of the Miyun reservoir is an important drinking water source in Beijing. In recent years, researchers have used the soil conservation service curve number (SCS-CN) model to calculate surface runoff for the district. Although the runoff forecasting accuracy was unsatisfactory, the lack of understanding of rainfall processes and their influence on runoff may explain the observed deviations. Our study sought to optimize and assess the SCS-CN model simulation accuracy for the district by proposing an SCS-CN calculation method for each runoff event (CNt) based on observation data for 253 rainfall and runoff events from 7 plots in the Miyun Shixia watershed. This study elucidated a significant positive correlation between the ratio of CNt and the average SCS-CN (CN1), as well as the ratio of the maximum X-minute rainfall amount (PX) to the total rainfall amount for each rainfall event (P). Furthermore, a calculation method involving power function equations between CNt/CN1 and PX/P was proposed for CNt. When X = 5 min and the initial abstraction ratio (λ) = 0.01, the simulation performance of the optimized model was the highest, with a Nash-Sutcliffe efficiency coefficient of 0.791, which was significantly higher than that of the non-optimized SCS-CN model. The simulation performance for bare and cultivated land was higher than that of other land uses, with Ef values of 0.831 and 0.828, respectively. Future research should focus on improving the prediction accuracy of runoff events resulting from high-intensity and short-duration rainfall events.

Identification of Schistosoma japonicum GSK3ß interacting partners by yeast two-hybrid screening and its role in parasite survival.

Schistosoma is the causative agent of schistosomiasis, a common infectious disease distributed worldwide. Our previous phosphoproteomic analysis suggested that glycogen synthase kinase 3 (GSK3), a conserved protein kinase in eukaryotes, is likely involved in protein phosphorylation of Schistosoma japonicum. Here, we aimed to identify the interacting partners of S. japonicum GSK3ß (SjGSK3ß) and to evaluate its role in parasite survival. Toward these ends, we determined the transcription levels of SjGSK3ß at different developmental stages and identified its interacting partners of SjGSK3ß by screening a yeast two-hybrid S. japonicum cDNA library. We further used RNA interference (RNAi) to inhibit the expression of SjGSK3ß in adult worms in vitro and examined the resultant changes in transcription of its putative interacting proteins and in worm viability compared with those of control worms. Reverse transcription-quantitative polymerase chain analysis indicated that SjGSK3ß is expressed throughout the life cycle of S. japonicum, with higher expression levels detected in the eggs and relatively higher expression level found in male worms than in female worms. By screening the yeast two-hybrid library, eight proteins were identified as potentially interacting with SjGSK3ß including cell division cycle 37 homolog (Cdc37), 14-3-3 protein, tegument antigen (I(H)A), V-ATPase proteolipid subunit, myosin alkali light chain 1, and three proteins without recognized functional domains. In addition, SjGSK3ß RNAi reduced the SjGSK3ß gene transcript level, leading to a significant decrease in kinase activity, cell viability, and worm survival. Collectively, these findings suggested that SjGSK3ß may interact with its partner proteins to influence worm survival by regulating kinase activity.

Spectroscopic Methodology and Molecular Docking Studies on Changes in Binding Interaction of Felodipine with Bovine Serum Albumin Induced by Cocrystallization with ß-Resorcylic Acid.

In the present study, a novel cocrystal of felodipine (FEL) and ß-resorcylic acid (ßRA) was developed. We specially focused on the change of binding pattern with bovine serum albumin (BSA) induced by cocrystallization of FEL with ßRA. The solid characterizations and density functional theory (DFT) simulation verified that FEL-ßRA cocrystal formed in equimolar ratio (1 : 1 M ratio) through C=O…H-O hydrogen bond between C=O group in FEL and O-H group in ßRA. The binding interactions between FEL-ßRA system and BSA were studied using fluorescence spectral and molecular docking methods. Two guest molecule systems, including a physical mixture of FEL and ßRA and FEL-ßRA cocrystal were performed binding to BSA in molecular docking. According to the Kb and binding energy, the supramolecular form of FEL-ßRA system was retained during binding to BSA. Molecular docking simulation suggested that FEL and its cocrystal inserted into the subdomain IIIA (site II') of BSA. The interactions between FEL and BSA including hydrogen bonding with ASN390 residue and intermolecular hydrophobic interactions with LEU429 and LEU452 residues. However, the size of supramolecular FEL-ßRA better matched that of active cavity of BSA; the cocrystal is closely bound to BSA through hydrogen bonding with ASN390 residue and intermolecular hydrophobic interactions with LEU429, VAL432, LEU452 and ILE387 residues. This change on binding affinity of FEL to BSA induced by cocrystallization with ßRA provided theoretical basis to evaluate the transportation, distribution and metabolism of cocrystal drug.

Low complexity OFDM VLC system enabled by spatial summing modulation.

Commercial-off-the-shelf (COTS) devices enabled visible light communication (VLC) for Internet of things (IoT) applications has attracted extensive attentions from both academic and industrial communities, thanks to the pervasive deployments of light emitting diode (LED) lighting infrastructure. However, due to the limitation of frequency response and non-linearity of the commercial illuminating LED light consisting of multiple LED chips, the achievable data rate is far less than that provided by the experimental VLC system with a single LED with specialized devices, e.g., lens. To this end, we propose a power-of-2 arrangement scheme for LED chips to generate spatial summing modulation with low control complexity, and demonstrate its availability in an orthogonal frequency division multiplexing (OFDM) VLC system purely built upon COTS devices. It significantly differs from a conventional OFDM VLC system relying on digital-to-analog converter (DAC) and analog signal chain, which is complex and confined by LED's non-linearity, thanks to we design a novel digital-to-light converter (DLC) which can output 256 light intensities linearly and be directly controlled by the discrete digital signals generated by the OFDM modulator. An experimental demonstration with employing the QAM-OFDM modulation scheme successfully confirms the effectiveness of the proposed spatial summing VLC system, which can achieve low BERs of below the forward error correct (FEC) threshold of 3.8×10-3 for both QAM8 and QAM16 running transmission frequency of 300 kHz under a communication distance of 0.8 m. It demonstrates the promising potential for delivering a data rate at hundred kbps level with this novel spatial summing based OFDM VLC system, which is sufficient for many IoT applications.

Identification and characterization of potent and selective inhibitors targeting protein tyrosine phosphatase 1B (PTP1B).

Protein tyrosine phosphatase 1B (PTP1B) plays an important role in the negative regulation of insulin and leptin signaling. The development of small molecular inhibitors targeting PTP1B has been validated as a potential therapeutic strategy for Type 2 diabetes (T2D). In this work, we have identified a series of compounds containing dihydropyridine thione and particular chiral structure as novel PTP1B inhibitors. Among those, compound 4b showed moderate activity with IC50 value of 3.33 µM and meanwhile with good selectivity (>30-fold) against TCPTP. The further MOA study of PTP1B demonstrated that compounds 4b is a substrate-competitive inhibitor. The binding mode analysis suggested that compound 4b simultaneously occupies the active site and the second phosphotyrosine (pTyr) binding site of PTP1B. Furthermore, the cell viability assay of compound 4b showed tolerable cytotoxicity in L02 cells, thus 4b may be prospectively used to further in vivo study.

Diverse and abundant antibiotics and antibiotic resistance genes in an urban water system.

The widespread use of antibiotics has resulted in pollution associated with antibiotics and antibiotic resistance genes (ARGs) in urban water systems, threatening the public health and the ecological security. In this study, the patterns of the diversity and abundance of the antibiotics and ARGs in a typical city (Kunming, China) were analyzed by monitoring their presence in the tap water, the land block sewage discharge units, the sewage pipes, the influent of WWTP, the effluent of WWTP, and the urban river channel. The results showed that although the average concentration of total antibiotics in tap water was 10 ng/L, the concentrations reached hundreds or even thousands of ng/L in all the other sections, indicating antibiotics entering water system through human or pets discharge. The relative abundances of ARG copies to 16S rRNA gene copies in the effluent of WWTP, the urban river channel which was the downstream of WWTP were higher than those of the sewage pipes, increasing risk of ARG transfer after treatment by WWTP. In general, the relative abundance of ARGs in spring was higher than that in winter. There was no significant correlation between antibiotics concentrations and their corresponding ARGs, except for a correlation between tetracyclines and tet-resistance genes. Due to the existence of transposases, the urban water system is exposed to a widespread risk of horizontal transfer of ARGs.