Increasing the sensor channels: a solution for the pressing offsets that cause the physiological parameter inaccuracy in radial artery pulse signal acquisition.

Introduction: In studies of pulse wave analysis, single-channel sensors only adopt single temporal pulse signals without spatial information to show pulse-feeling patterns. Multi-channel arterial pulse signals, also named as three-dimensional pulse images (3DPIs), provide the spatial and temporal characteristics of radial pulse signals. When involving single or few-channel sensors, pressing offsets have substantial impacts on obtaining inaccurate physiological parameters like tidal peak (P2). Methods: This study discovers the pressing offsets in multi-channel pulse signals and analyzes the relationship between the pressing offsets and time of P2 (T2) by qualifying the pressing offsets. First, we employ a data acquisition system to capture 3DPIs. Subsequently, the errorT2 is developed to qualify the pressing offsets. Results: The outcomes display a central low and peripheral high pattern. Additionally, the errorT2 increase as the distances from the artery increase, particularly at the radial ends of the blood flow direction. For every 1 mm increase in distances between sensing elements and center sensing elements, the errorT2 in the radial direction escalates by 4.87%. When the distance is greater than 3.42 mm, the errorT2 experiences a sudden increase. Discussion: The results show that increasing the sensor channels can overcome the pressing offsets in radial pulse signal acquisition.

A reliable evaluation approach for multichannel signal denoising algorithms based on a novel arterial pulse acquisition system.

Background: Tactile sensors are utilized to measure multichannel pulse signals in pulse wave analysis (PWA). Owing to noise interferences, researchers have applied various denoising algorithms on multichannel pulse signals. To comprehensively assess these algorithms, numerous evaluation metrics have been proposed. However, these studies did not investigate the noise mechanisms in depth and lacked reference pulse signals, thus making the evaluations insufficiently objective. Materials and methods: An applicable denoising evaluation approach for multichannel pulse signal algorithms based on an arterial pulse acquisition system is established by superimposing real-world multichannel noise to the reference signals. The system, comprising a SphygmoCor and a uniaxial noise acquisition device, allows us to acquire single-reference pulse signals as well as real-world multichannel noise. Results: We assess eight popular denoising algorithms with three evaluation metrics, including amplitude relative error (ARE), mean square error (MSE) and increased percentage signal-noise ratio (SNR%). Our proposed approach provides accurate and objective evaluations of multichannel pulse signal denoising. Notably, classic algorithms for single-channel denoising are not recommended for multichannel denoising. Comparatively, RPCA-based algorithms can denoise pulse signals independently for each channel. Conclusion: This study sets the stage for the establishment of accurate and objective pulse signal denoising evaluations and provides insights for data-driven clinical diagnoses in cardiovascular medicine.

Interpretable and accurate curve-fitting method for arterial pulse wave modeling and decomposition.

Arterial pulse waveforms contain a wealth of information about the cardiovascular system. There is a lack of physical meaning in the mathematical model of arterial pulse waves, while the physical model fails to offer individuality as too many assumptions are involved. In this article, we focus on promoting the interpretability of the arterial pulse mathematical model. The proposed method is based on newly developed 3-term fitting functions individualized by the physiological parameter assignment, which are the peak times of the reflected and dicrotic waves in a pulse. In this manner, the model allows decomposition of the pulse into sub-signals with clear physiological significance. With nearly 10,000 pulse fitting experiments, it is demonstrated that the proposed method outperforms the standard methods in fitting accuracy while providing parameters linked to hemodynamic characteristics and common clinical indices such as the peripheral augmentation index (pAI). The proposed method innovatively maintains the individuality and accuracy of mathematical models while improving the interpretability of their parameters. The applications of this newly developed method, which explicitly incorporates hemodynamic characteristics, are expected to be particularly valuable in future pulse wave decomposition studies.

Adsorption Recycling and High-Value Reutilization of Heavy-Metal Ions from Wastewater: As a High-Performance Anode Lithium Battery.

The dazzling adsorbent products make people overlook the harm of heavy metals adsorbed on them. Hazardous waste adsorbents cause secondary pollution. In this study, waste lignocellulose was dissolved by alkaline urea solvent and high-intensity ultrasound, then cross-linked by epichlorohydrin to make hydrogel, which was utilized to adsorb toxic heavy-metal wastewater. In situ deposition and high-temperature carbonization turn the gel that has absorbed heavy metals into carbon aerogel-loaded metal oxide energy storage materials that may be employed as anodes in lithium-ion batteries with excellent electrochemical performance. The best reversible capacity was 435.86 mAh g-1 after 100 cycles at 0.2C, indicating that the hazardous solid waste generated by the removal of heavy metals using biomass-based adsorbent has potential lithium battery applications. Thus, we provide a fresh perspective on the efficient recycling of heavy metals as well as an environmentally friendly, high-value conservation strategy for lowering the danger of heavy-metal hazardous wastes.

Analysis of titer stability and inactivation kinetics of harvest solution of SARS-CoV-2 / 中国生物制品学杂志

@#Objective To investigate the titer stability of the harvest solution of severe acute respiratory syndrome coronavirus2(SARS-CoV-2)at 2 ～ 8 ℃ and the inactivation effect of β-propiolactone inactivator on the virus.Methods Three batches of SARS-CoV-2 harvest solution(batch numbers:202111001,202111002 and 202111003)were stored at 2 ～ 8 ℃ for 12 d and sampled every 3 d(0,3,6,9 and 12 d)for detection of the titers by Karber method;Three batches of virus harvest solution equilibrated overnight at 2 ～ 8 ℃ were inactivated by adding β-propiolactone at a volume fraction of 1∶4 000 and detected for the titers at different inactivation time points(0,0.5,1,1.5,2,3,4,8,16 and 24 h),of which samples inactivated for 8,16 and 24 h were taken for inactivation verification,and samples inactivated for 24 h were observed by transmission electron microscope.Results The titers of SARS-CoV-2 decreased with the prolongation of storage time at 2 ～8 ℃,which showed no obvious decrease during 0 ～ 3 d,while decreased from the initial 7.75,6 and 7.5 lgCCID_(50)/mL to5.75,4.625 and 6.25 lgCCID_(50)/mL on day 12,indicating that the virus activity showed a gradual decrease trend at 2 ～8 ℃；With the inactivation time,the virus titer decreased continuously and could not be detected after inactivation for 3 h.Transmission electron microscope observation showed that the inactivated virus particles were intact and the spike protein was evenly distributed.Conclusion The virulence of SARS-CoV-2 stored at 2 ～ 8 ℃ was unstable,so the subsequent inactivation and purification process should be carried out as soon as possible;The titer of virus could not be detected after3 h of inactivation,which provided a reference for the determination of the inactivation process.

Realizing Mechanically Robust and Electrically Conductive Wood via Vacuum Pressure Impregnation.

Wood is highly regarded as the most sustainable resource that is widely used in structural applications. To extend its practicality in electrically conductive applications, it is necessary to confer electrical conductivity to the insulating wood. The most common strategy is to derive carbonized wood powder via an annealing process. Even though these carbonized wood powders are electrically conductive, they lost the ancestry characteristic of wood, that is, excellent mechanical properties. As such, it is of great importance to realize the concept of conductive wood while at the same time maintaining or even enhancing its mechanical properties further. By leveraging on the naturally formed transportation channels found in trees, conductive particles can be aligned along these ordered channels. To substitute active transport in living plants, a vacuum pressure impregnation process was used to infiltrate these conductive particles into the transportation channels. As a result, Cu/wood composite, denoted as Cu-SW, exhibited a minimum volume resistivity of 1.366 × 103 Ω cm, which was lower than those of conventional semiconductors. High Cu loading of ∼43.1 volume % of the final product, Cu-SW, was achieved with such technique, which clearly indicates the ability to achieve deep penetration of Cu nanoparticles into the bulk wood. Furthermore, an encouraging mechanical properties improvement of ∼50% was recorded for Cu-SW as compared to the wood matrix. With the enhancement in both conductivity and mechanical properties, Cu-SW could be used in load-bearing application that requires electrical conduction.

Lignocellulose@ Activated Clay Nanocomposite with Hierarchical Nanostructure Enhancing the Removal of Aqueous Zn(II).

A lignocellulose@ activated clay (Ln@AC) nanocomposite with a hierarchical nanostructure was successfully synthesized by the chemical intercalation reaction and applied in the removal of Zn(II) from an aqueous solution. Ln@AC was characterized by N2 adsorption/desorption isotherms and X-Ray Diffraction (XRD), scanning Electron Microscope (SEM), transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR) analysis, and the results indicate that an intercalated-exfoliated hierarchical nanostructure was formed. The effects of different adsorption parameters on the Zn(II) removal rate (weight ratio of Ln to AC, Ln@AC dosage, initial Zn(II) concentration, pH value, adsorption temperature, and time) were investigated in detail. The equilibrium adsorption capacity reached 315.9 mg/g under optimal conditions (i.e., the weight ratio of Ln to AC of 3:1, Ln@AC dosage of 1 g/L, initial Zn(II) concentration of 600 mg/L, pH value of 6.8, adsorption temperature of 65 °C, and adsorption time of 50 min). The adsorption process was described by the pseudo-second-order kinetic model, Langmuir isotherm model, and the Elovich model. Moreover, Zn(II) could be easily eluted by HCl, and the effects of HCl concentration, desorption temperature, and ultrasonic desorption time on desorbed amount were tested. Desorption studies revealed that with an HCl concentration of 0.25 mol/L, desorption temperature of 70 °C, and ultrasonic desorption time of 20 min, the maximum desorption capacity and efficiency were achieved at 202.5 mg/g and 64.10%, respectively. Regeneration experimental results indicated that the Ln@AC exhibited a certain recyclable regeneration performance. Due to such outstanding features, the novel Ln@AC nanocomposite proved to have great adsorption potential for Zn(II) removal from wastewater, and exhibited an extremely significant amount of adsorbed Zn(II) when compared to conventional adsorbents.

Rapid Removal of Zinc(II) from Aqueous Solutions Using a Mesoporous Activated Carbon Prepared from Agricultural Waste.

A low-cost activated carbon (XSBLAC) prepared from XanthocerasSorbifoliaBungehull via chemical activation was investigated to determine its adsorption and desorption properties for zinc(II) ions from aqueous solutions. XSBLAC was characterized based on its N2-adsorption/desorption isotherm, EDX, XRD, SEM and FTIR results. An adsorption study was conducted in a series of experiments to optimize the process variables for zinc(II) removal using XSBLAC. Modeling the adsorption kinetics indicated good agreement between the experimental data and the pseudo-second-order kinetic model. The Langmuir equilibrium isotherm fit the experimental data reasonably well. The calculated enthalpy (ΔH°), entropy (ΔS°) and Gibbs free energy (ΔG°) values revealed the endothermic and spontaneous nature of the adsorption process. HNO3 displayed the best desorption performance. The adsorption mechanism was investigated in detail through FTIR and SEM/EDX spectroscopic analyses. The results suggested that XSBLAC is a potential biosorbent for removing zinc(II) from aqueous solutions.

Adsorption of iron(III), cobalt(II), and nickel(II) on activated carbon derived from Xanthoceras Sorbifolia Bunge hull: mechanisms, kinetics and influencing parameters.

Xanthoceras Sorbifolia Bunge hull activated carbon (XSA) was prepared and characterized by Brunauer-Emmett-Teller analysis, scanning electron microscopy and energy dispersive X-ray (EDX) spectroscopy. The ability of XSA as an adsorbent was investigated for the removal of the iron group ions Fe(III), Co(II), and Ni(II) from aqueous solution. Optimum adsorption parameters were determined based on the initial concentrations of the iron group ions, pH, adsorption temperature, and adsorption time in adsorption studies. The maximum monolayer adsorption capacities were 241.13 mg/g for Fe(III), 126.05 mg/g for Co(II), and 187.96 mg/g for Ni(II), respectively. Adsorption kinetics and isotherms showed that the adsorption process best fitted the nonlinear pseudo-second-order and Langmuir models, and the affinity of the ions for XSA decreased as follows: Fe(III) > Ni(II) > Co(II). Regeneration studies indicated that XSA could be used after several consecutive adsorption/desorption cycles using HNO3. Fourier transform infrared and EDX spectra revealed the chemical adsorption value of XSA as an adsorbent for removing iron group ions from aqueous solutions.