Compressive sensing method to leverage prior information for submerged target echoes.

Reducing data volume and improving signal-to-noise ratio (SNR) is of great importance for echoes from submerged targets, affected by serious marine environment noise. The echo from a target is made of its response to the incident wave with the superposition of highlights (sub-echoes from main constituents of the target). Each of these highlights can be seen as a block, and the echo therefore has a block-sparse feature. This paper proposes a compressive sensing method to leverage prior information (CSPI), in which knowledge of the incident wave and the block-sparse feature are leveraged into the dictionary structure and signal reconstruction. CSPI is illustrated with simulations and field measurements of backscattering for a 1:20 model of the Benchmark Target Strength Simulation Submarine. For simulated signals with different noise levels, CSPI can reconstruct an almost invisible signal (original SNR = 0 dB), and improve SNR by up to 13 dB (for an original SNR of 4 dB) down to a still significant SNR of 7 dB (for an original SNR of 0 dB). For field measurements, CSPI can obtain the same SNR as the original signal using only 13% of the data, increasing the SNR to 15 dB using 30% data, and increasing with the compression ratio.

Insertion approach: bolstering the reproducibility of electrochemical signal amplification via DNA superstructures.

For more than a decade, the backfilling approach for the immobilization of DNA probes has been routinely adopted for the construction of functional interfaces; however, reliably reproducing electrochemical signal amplification by this method is a challenge. In this research, we demonstrate that the insertion approach significantly bolsters the reproducibility of electrochemical signal amplification via DNA superstructures. The combination of the backfilling approach and the DNA superstructure formation poses a big challenge to reliably reproducing electrochemical signal amplification. In order to use the detection of Hg(2+) as a prototype of this new strategy, a thymine-rich DNA probe that is specific to mercury ion was applied in this study. The presence of Hg(2+) induces the folding of the DNA probes and inhibits the formation of DNA superstructures. By using electroactive probes ([Ru(NH3)6](3+)) that are electrostatically adsorbed onto the double strands, differential pulse voltammetry (DPV) could quantitatively confirm the presence of Hg(2+). A limit of detection (LOD) and a limit of quantification (LOQ) (LOQ) as low as 0.3 and 9.5 pM, respectively, were achieved. Furthermore, excellent selectivity and real sample analysis demonstrated the promising potential of this approach in future applications.

Degradation of norfloxacin by the synergistic effect of micro-nano bubbles and sodium hypochlorite: kinetics, influencing factors and pathways.

This study thoroughly investigated the degradation of norfloxacin (NOR) under the influence of micro-nanobubbles (MNBs) and sodium hypochlorite (NaClO), focusing on their synergistic effects. The impact of various environmental factors, including NaClO concentration, pH, inorganic anions, and surfactants, on NOR degradation efficiency within the MNBs/NaClO system was systematically assessed. The basic properties of the MNBs/NaClO system and the degradation kinetics of NOR were explored. The degradation products and pathways of NOR were explored to reveal the degradation mechanism of antibiotics in the MNBs/NaClO system by employing density functional theory (DFT) and high-performance liquid chromatography-mass spectrometry (HPLC-MS). The redox potential of the MNBs/NaClO system exhibited significantly superior properties than the single system, with bubble sizes predominantly in the nanoscale. The degradation kinetics of NOR adhered to a pseudo-first-order reaction model, with optimal degradation occurring at a 0.025% NaClO volume concentration. Acidic conditions promoted the degradation of NOR, and alkaline conditions inhibited the degradation of NOR. Inorganic anions PO43-, HCO3-, and CO32- in the water matrix led to strong inhibition of NOR degradation. Cationic surfactants accelerated the degradation process of NOR, while anionic and nonionic surfactants had a consistent inhibitory effect on the degradation of NOR. Based on the degradation behavior, three potential pathways for NOR degradation were proposed: quinolone group transformation, defluorination reaction, piperazine ring cracking and quinolone ring decomposition. This research contributes a novel technical approach for addressing antibiotic pollution and offers a theoretical framework for understanding the fate of antibiotics in the environment.

Stimulation of bioluminescence in Noctiluca sp. using controlled temperature changes.

Bioluminescence induced by multifarious stimuli has long been observed and is remains under investigation because of its great complexity. In particular, the exact mechanism underlying bioluminescence is not yet fully understood. This work presents a new experimental method for studying Noctiluca sp. bioluminescence under temperature change stimulation. It is a study of Noctiluca sp. bioluminescence using controlled temperature changes in a tank. A characteristic of this experiment is the large volume of water used (1 m(3) in a tank of 2 × 1 × 1 m). Temperature changes were controlled by two methods. In the first, a flask filled with hot water was introduced into the tank and in the second, a water heater was used in the tank. Temperature changes were recorded using sensors. Noctiluca sp. bioluminescence was recorded using a Canon 5D Mark II and this allowed the characteristics of Noctiluca sp. bioluminescence under temperature change stimulation to be monitored.

3-[(2-Formyl-thio-phen-3-yl)(hy-droxy)meth-yl]thio-phene-2-carbaldehyde.

In the title compound, C(11)H(8)O(3)S(2), the dihedral angle between the mean planes of the two thio-phene rings is 65.10 (10)°. Intra-molecular C-H⋯O inter-actions form S(6) and S(7) ring motifs. In the crystal, chains along the a axis are formed by C-H⋯O inter-actions. Adjacent chains are connected into a three-dimensional network by C-H⋯O and O-H⋯O inter-actions.

Impact of catheter-tissue contact force on lesion size during right ventricular outflow tract ablation in a swine model.

BACKGROUND: The catheter-tissue contact force (CF) is one of the significant determinants of lesion size and thus has a considerable impact on the effectiveness of ablation procedures. This study aimed to evaluate the impact of CF on the lesion size during right ventricular outflow tract (RVOT) ablation in a swine model. METHODS: Twelve Guangxi Bama miniature male pigs weighing 40 to 50 kg were studied. After general anesthesia, a ThermoCool SmartTouch contact-sensing ablation catheter was introduced to the RVOT via the femoral vein under the guidance of the CARTO 3 system. The local ventricular voltage amplitude and impedance were measured using different CF levels. We randomly divided the animals into the following four groups according to the different CF levels: group A (3-9 g); group B (10-19 g); group C (20-29 g); and group D (30-39 g). Radiofrequency ablations were performed at three points in the free wall and septum of the RVOT in power control mode at 30 W for 30 s while maintaining the saline irrigation rate at 17 mL/min. At the end of the procedures, the maximum depth, surface diameter, and lesion volume were measured and recorded. A linear regression analysis was performed to determine the relationship between continuous variables. RESULTS: A total of 72 ablation lesions were created in the RVOT of the 12 Bama pigs. The maximum depth, surface diameter, and volume of the lesions measured were well correlated with the CF (free wall: ß = 0.105, ß = 0.162, ß = 3.355, respectively, P < 0.001; septum: ß = 0.093, ß = 0.150, ß = 3.712, respectively, P < 0.001). The regional ventricular bipolar voltage amplitude, unipolar voltage amplitude, and impedance were weakly positively associated with the CF (ß = 0.065, ß = 0.125, and ß = 1.054, respectively, P < 0.001). There was a significant difference in the incidence of steam pops among groups A, B, C, and D (free wall: F = 7.3, P = 0.032; septum: F = 10.5, P = 0.009); and steam pops occurred only when the CF exceeded 20 g. Trans-mural lesions were observed when the CF exceeded 10 g in the free wall, while the lesions in the septum were non-trans-mural even though the CF reached 30 g. CONCLUSIONS: CF seems to be a leading predictive factor for the size of formed lesions in RVOT ablation. Maintaining the CF value between 3 and 10 g may be reasonable and effective for creating the necessary lesion size and reducing the risk of complications, such as steam pops and perforations.

A light transmission technique for pore size measurement in track-etched membranes.

A new approach is proposed for accurate measurement of the pore sizes in a track-etched PET membrane (polyethylene terephthalate) from a nanometer scale to a submicrometer scale, which only entailed UV-Vis spectrometry.