Diagnostic strategy of metagenomic next-generation sequencing for gram negative bacteria in respiratory infections.

OBJECTIVE: This study aims to identify the most effective diagnostic method for distinguishing pathogenic and non-pathogenic Gram-negative bacteria (GNB) in suspected pneumonia cases using metagenomic next-generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) samples. METHODS: The effectiveness of mNGS was assessed on BALF samples collected from 583 patients, and the results were compared with those from microbiological culture and final clinical diagnosis. Three interpretational approaches were evaluated for diagnostic accuracy. RESULTS: mNGS outperformed culture significantly. Among the interpretational approaches, Clinical Interpretation (CI) demonstrated the best diagnostic performance with a sensitivity of 87.3%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 98.3%. CI's specificity was significantly higher than Simple Interpretation (SI) at 37.9%. Additionally, CI excluded some microorganisms identified as putative pathogens by SI, including Haemophilus parainfluenzae, Haemophilus parahaemolyticus, and Klebsiella aerogenes. CONCLUSION: Proper interpretation of mNGS data is crucial for accurately diagnosing respiratory infections caused by GNB. CI is recommended for this purpose.

Quality study of animal-derived traditional Chinese medicinal materials based on spectral technology: Calculus bovis as a case.

INTRODUCTION: Calculus bovis (C. bovis) is a typical traditional Chinese medicine (TCM) derived from animals, which has a remarkable curative effect and high price. OBJECTIVES: Rapid identification of C. bovis from different types was realized based on spectral technology, and a rapid quantitative analysis method for the main quality control indicator bilirubin was established. METHODS: We conducted a supervised and unsupervised pattern recognition study on 44 batches of different types of C. bovis by five spectral pretreatment methods. Three variable selection methods were used to extract the essential information, and the partial least squares regression (PLSR) quantitative model of bilirubin by near-infrared (NIR) spectroscopy was constructed. RESULTS: The partial least squares discriminant analysis (PLS-DA) model could achieve 100% accuracy in identifying different types of C. bovis. The R2 of the NIR quantitative model was 0.979, which is close to 1, and the root mean square error of calibration (RMSEC) was 2.3515, indicating the good prediction ability of the model. CONCLUSION: The study was carried out to further improve the basic data of quality control of C. bovis and help the high-quality development of TCM derived from animals.

Synthesis of chitosan-based grafting magnetic flocculants for flocculation of kaolin suspensions.

A series of novel chitosan-based magnetic flocculants FS@CTS-P(AM-DMC) was prepared by molecular structure control. The characterization results showed that FS@CTS-P(AM-DMC) had a uniform size of about 21.46 nm, featuring a typical core-shell structure, and the average coating layer thickness of CTS-P(AM-DMC) was about 5.03 nm. FS@CTS-P(AM-DMC) exhibited excellent flocculation performance for kaolin suspension, achieved 92.54% turbidity removal efficiency under dosage of 150 mg/L, pH 7.0, even at high turbidity (2000 NTU) with a removal efficiency of 96.96%. The flocculation mechanism was revealed to be dominated by charge neutralization under acidic and neutral conditions, while adsorption and bridging effects play an important role in alkaline environments. The properties of magnetic aggregates during flocculation, breakage, and regeneration were studied at different pH levels and dosages. In the process of magnetophoretic, magnetic particles collide and adsorb with kaolin particles continuously due to magnetic and electrostatic attraction, transform into magnetic chain clusters, and then further form three-dimensional network magnetic aggregates that can capture free kaolin particles and other chain clusters. Particle image velocimetry confirmed the formation of eddy current of magnetic flocs and experienced three stages: acceleration, stabilization, and deceleration.

Enhanced optoelectronic reservoir computation using semiconductor laser with double delay feedbacks.

We numerically explored the enhanced performance and physical mechanism of semiconductor laser (SL) based reservoir computation (RC) with double optoelectronic feedback (DOEF). One-step and multistep Santa Fe time series predictions were used as standard test benchmarks in this work. We found that in the optimized parameter region the normalized mean square error (NMSE) of an SL-based RC under DOEF is smaller than an SL-based RC with single optoelectronic feedback (SOEF). In addition, the performance improvement is more obvious for multistep prediction, which is particularly suitable for more complex tasks that requires a higher memory capability (MC). The enriched node states (optical intensity of the virtual nodes for each sample) and the enhanced MC of the proposed DOEF were verified by a comparison to SOEF under the optimized feedback strength. The influence of the feedback strength and the delay difference on the NMSE and the MC was also investigated. Our study should be helpful in the design of a high-performance optoelectronic RC based on an SL.

Nondestructive rapid identification of wild Cordyceps sinensis with portable instrument.

INTRODUCTION: Cordyceps sinensis (CS) is a precious medicinal fungus. Wild CS (WCS) and artificial CS (ACS) are destroyed for their identification using traditional methods, which are time consuming and labor-intensive. Therefore, it is crucial to establish a nondestructive identification method to rapidly screen WCS. OBJECTIVE: The aim of this study was to provide technical support for rapid screening of CS and evaluation of its quality. The applicability of the model was improved through model transfer. METHODS: In this study, continuous wavelet transform was used to analyze the differences in moisture content and active components between WCS and ACS from the perspective of characteristic molecular groups. A portable instrument and a laboratory benchtop instrument were used to determine CS spectra. Partial least squares discrimination analysis was conducted for the identification of WCS and ACS while preserving the original shape of CS. Moreover, improved principal component analysis was utilized to transfer the model between the two types of near-infrared spectroscopy (NIRS) instruments. RESULTS: The results demonstrated that three peaks, at 1443, 1941, and 2183 nm, were characteristic absorption peaks. The model based on NIRS could initially provide rapid differentiation between WCS and ACS. At the same time, the accuracy of the external test set was further improved to over 95% through forward transfer. CONCLUSION: Therefore, this method could be used for rapid screening of WCS and provides technical support for the nondestructive identification of CS and initial assessment of CS quality.

Distribution, source, risk and phytoremediation of polycyclic aromatic hydrocarbons (PAHs) in typical urban landscape waters recharged by reclaimed water.

A park that had used reclaimed water as the sole water supply for fourteen years, was selected to analyze the distribution, sources and risks of 16 priority polycyclic aromatic hydrocarbons (PAHs) in waters and sediments. The effects of phytoremediation were investigated in waterbodies classified as phytoremediation, transitional and non-phytoremediation areas. Diagnostic ratio (DR) and principal component analysis (PCA) were used to analyze the sources of PAHs, while risk quotient (RQ) was used as risk assessment tool. Results showed that ∑PAH concentrations in sediments ranged from 29.4 to 1245.6 ng‧g-1, with average of 354.3 ng‧g-1, corresponding to a moderate pollution level. The concentration of PAHs in water ranged from 10.6 to 326.3 ng‧L-1, with average of 147.2 ng‧L-1, corresponding to a low pollution level. The ∑PAHs in sediments showed a downward trend from northwest to southeast along with the water flow direction, with average values of 459.5, 362.9 and 246.1 ng‧L-1 in the upstream, midstream and downstream, respectively. In contrast, PAH concentrations in water were consistent with recreational activities in the urban park area. There were 95% of water samples and 72% of sediment samples obtaining the Ant/(Ant + Phe) > 0.1 and Flu/(Flu + Pyr) > 0.5, indicating that coal combustion was the major source of PAHs in both the water and sediment. The RQ∑PAH(NCs) values in water and sediment were all between 1 and 800, while RQ∑PAH(MPCs) reached equal to 0, suggesting that ∑PAHs presented a low ecological risk. Acenaphthene accounted for 28.4% of RQ(NCs), and became the most risk PAH in water column. Aquatic plants effectively removed high-ring PAHs from water and middle-ring PAHs from sediments, reducing the overall risks posed by PAHs.

Exosomes derived from human umbilical cord mesenchymal stem cells (HUCMSC-EXO) regulate autophagy through AMPK-ULK1 signaling pathway to ameliorate diabetic cardiomyopathy.

One of the main causes of severe diabetic heart failure and mortality is diabetic cardiomyopathy (DCM), a cardiovascular condition attributable to diabetes with a high incidence, a complicated and unexplained pathophysiology, and poor treatment results. Current findings have demonstrated that the onset of diabetic cardiomyopathy involves autophagy, inflammation, and mitochondrial damage. Myocardial autophagy behaves differently in different states,and one of the targets for the detection and treatment of cardiovascular illnesses like diabetic cardiomyopathy may be the control of autophagy. The role of human umbilical cord Mesenchymal stem cells-derived exosomes (HUCMSC-EXO) as a non-cellular system in the repair of cardiomyocytes, the evolution of diabetic cardiomyopathy and their cardioprotective effects are gradually being recognized. This study's objectives were to assess the therapeutic benefits of HUCMSC-EXO for diabetic cardiomyopathy and to look into their potential mechanisms of action. High-speed centrifugation was used to extract HUCMSC-EXO, and the shape of the exosomes was examined using transmission electron microscopy. Immunoblotting was used to determine the expression of CD9, CD63, and TSG101 molecules on the surface of the exosomes. A high-fat, high-sugar diet mixed with streptozotocin was used to build a rat model of type 2 diabetic cardiomyopathy. Cardiac function, ventricular wall thickness and cardiac histological changes were examined by cardiac ultrasound, serum BNP and histology. In cardiac myocytes, HUCMSC-EXO reduced the levels of autophagy-related protein expression. Additionally, immunoblotting supported our suspicion that this mechanism is strongly tied to the activation of the AMPK-ULK1 signaling pathway. So, we propose that it would be a good strategy to follow for treating diabetic cardiomyopathy. These findings offer both fresh concepts for building a model of diabetic cardiomyopathy and a creative theoretical framework for using HUCMSC-EXO to treat diabetic cardiomyopathy in a clinical setting.

Towards fast sensing along ultralong BOTDA: flatness enhancement by utilizing injection-locked dual-bandwidth probe wave.

Brillouin optical time-domain analysis (BOTDA) using distributed Brillouin amplification (DBA) only requires a milliwatt-level pump to achieve a sensing range beyond 100 km, which provides a powerful tool for temperature/strain sensing. However, similar to the majority of other long-range BOTDAs, the state-of-the-art reports require > 1000 times average, severely restricting the sensing speed. The blind area over tens of kilometers caused by the nonuniform Brillouin response and parasitic amplitude modulation (AM) are crucial factors affecting the signal-to-noise ratio (SNR). Here, a comprehensive performance optimization and substantial enhancement for BOTDA sensors was presented by the direct demodulation of an injection-locked dual-bandwidth probe wave. Injection locking (IL) can completely eliminate the impact of AM noise; dual-bandwidth probe enables self-adaptive pulse loss compensation, thereby intensifying the SNR flatness along the ultralong fiber, and direct probe demodulation can overcome nonlocal effects and allows ∼19.7 dB enhancement of probe input power. Therefore, using only 100 times average, ∼148.3 km sensing, and ∼5 m spatial resolution were achieved with < ∼0.8 MHz standard deviation of Brillouin frequency shift (BFS) over a broad range (∼131.7 km). The reduction in averages was more than 10 times that of the reported majority of long-range BOTDAs. Such performances were achieved without using time-consuming or post-processing techniques, such as optical pulse coding and image denoising. Because this approach is compatible with optical chirp chain technique without frequency sweeping, fast acquisition (0.3 s) was also realized, which has the potential for fast sensing at 3.3 Hz along a ∼150 km fiber.

Surface Charge Density Gradient Printing To Drive Droplet Transport: A Numerical Study.

Traditional strategies, such as morphological or chemical gradients, struggle to realize the high-velocity and long-distance transport for droplets on a solid surface because of the pinning hydrodynamic equilibrium. Thus, there is a continuing challenge for practical technology to drive droplet transport over the last decades. The surface charge density (SCD) gradient printing method overcame the theoretical limit of traditional strategies and tackled this challenge [Nat. Mater. 2019, 18: 936], which utilized the asymmetric electric force to realize the high-velocity and long-distance droplet transport along a preprinted SCD gradient pathway. In the present work, by coupling the electrostatics and the hydrodynamics, we developed an unexplored numerical model for the water droplet transporting along the charged superhydrophobic surface. Subsequently, the effects of SCD gradients on the droplet transport were systematically discussed, and an optimized method for SCD gradient printing was proposed according to the numerical results. The present approach can provide early guidance for the SCD gradient printing to drive droplet transport on a solid surface.

Passive Anti-Icing and Active Electrothermal Deicing System Based on an Ultraflexible Carbon Nanowire (CNW)/PDMS Biomimetic Nanocomposite with a Superhydrophobic Microcolumn Surface.

The icephobicity property of multifunctional surfaces has been widely studied due to their potential application in the aerospace field. Herein, a controllable CNW/PDMS biomimetic nanocomposite film with a superhydrophobic surface is fabricated. The microcolumns are etched on the surface of the biomimetic nanocomposite to provide superhydrophobicity. Two defense strategies of biomimetic nanocomposites are proposed while passive anti-icing and active electrothermal deicing behaviors of the biomimetic nanocomposite are experimentally studied. It is found that the initial nucleation time of a single water droplet is delayed by 353.3 s on the superhydrophobic surface relative to the hydrophilic surface. The adhesion strength increases with the increase of surface roughness. The heating uniformity on the biomimetic nanocomposite surface was validated by infrared thermography technology. The ice layer is completely melted within 150 s under 40 V voltage captured by a noncontact infrared camera. The proposed strategy was validated by the characterization of the passive anti-icing and active electrothermal deicing property from biomimetic nanocomposites with superhydrophobic microstructure surfaces. Research results show that the two lines of defense collaborative work for an icephobicity system were able to keep biomimetic nanocomposite surfaces ice-free under test conditions.

Modeling and Measurement on the Sliding Behavior of Microgrooved Surfaces.

The sliding behavior of anisotropic surfaces is a crucial property to their applications from fundamental research to practical fields. Herein, we propose a theoretical model for analyzing the sliding behavior based on the concept of adhesion energy. Surface Evolver simulation is conducted to determine the adhesion energy per unit area. The microgrooved surfaces are fabricated and characterized to validate the proposed theory. It is found that the apparent contact angle measured along the direction parallel to the strips increases with the increase of microgroove width, while the corresponding sliding angles exhibit an opposite trend. The adhesion energy per unit area has a constant value regardless of the droplet volume. The different sliding behaviors of anisotropic surfaces along the perpendicular and parallel directions are attributed to the difference in the corresponding adhesion energies per unit area. The proposed model is expected to be used for predicting the sliding behavior of anisotropic surfaces.

Experimental and analytical studies on the flexible, low-voltage electrothermal film based on the multi-walled carbon nanotube/polymer nanocomposite.

This paper presents multi-walled carbon nanotube (MWCNT)/poly(m-phenylene isophthalamide) (PMIA) nanocomposite films as electrothermal elements, which offer advantages in flexibility, low energy consumption and rapid temperature growth. The electrical properties, electrothermal behavior and thermal stability of the films were investigated as a function of MWCNT content. The percolation behavior analysis revealed MWCNTs built a continuously conductive network in PMIA matrix at the corresponding percolation threshold of ∼0.06 wt%. The electrothermal behavior of the MWCNT/PMIA film was investigated by considering temperature response rapidity and electrothermal efficiency under different ambient conditions. For the film with 7.0 wt% MWCNTs under different ambient conditions, the film worked at a high heating rate of 1.0-8.2 °C s-1 and cooling rate of 0.75-7.0 °C s-1 under a low voltage of 3-12 V, due to the low electrical resistivity (4.5 Ω cm) of the film. The prepared MWCNT/PMIA films supported more outstanding heating performance than conventional PI-Kanthal film, including good heating uniformity, higher electrothermal efficiency and heating/cooling rate. Moreover, the improved thermomechanical properties of the nanocomposite were observed by dynamic thermomechanical analysis.

In-situ self-assembly of plant polyphenol-coated Fe3O4 particles for oleaginous microalgae harvesting.

Plant polyphenol (PP), a natural polymer from the Larix gmelinii, was selected as the surfactant to synthesize Fe3O4. The Fe3O4-PP composite was prepared by in-situ self-assembly in solvothermal synthesis, and characterized using FE-SEM, TEM, XRD, FTIR, XPS, TGA, and VSM. The harvesting efficiency of Chlorella vulgaris was investigated under different parameters, including algal organic matter, dosage, and pH. The results showed that the core-shell sphere of Fe3O4-PP (∼150 nm) was coated by ∼50 nm PP with a saturated magnetization of 40.0 emu/g. The Fe3O4-PP could be directly applied to the culture broth (1.5 g dry cell weight/L, pH = 9.03), achieving 93.0% of harvesting efficiency at 20 g/L. Cells were detached from the harvested aggregates by adjusting pH value to 9.80 and with ultrasonication, which achieved 95.6% of recovery efficiency. The recycled Fe3O4-PP showed high stabilities in surface properties, maintaining more than 87.5% of harvesting efficiency after five recycles.

Phosphate removal from domestic wastewater using thermally modified steel slag.

This study was performed to investigate the removal of phosphate from domestic wastewater using a modified steel slag as the adsorbent. The adsorption effects of alkalinity, salt, water, and thermal modification were investigated. The results showed that thermal activation at 800°C for 1 hr was the optimum operation to improve the adsorption capacity. The adsorption process of the thermally modified slag was well described by the Elovich kinetic model and the Langmuir isotherm model. The maximum adsorption capacity calculated from the Langmuir model reached 13.62 mg/g. Scanning electron microscopy indicated that the surface of the modified slag was cracked and that the texture became loose after heating. The surface area and pore volume did not change after thermal modification. In the treatment of domestic wastewater, the modified slag bed (35.5 kg) removed phosphate effectively and operated for 158 days until the effluent P rose above the limit concentration of 0.5 mg/L. The phosphate fractionation method, which is often applied in soil research, was used to analyze the phosphate adsorption behavior in the slag bed. The analysis revealed that the total contents of various Ca-P forms accounted for 81.4%-91.1%, i.e., Ca10-P 50.6%-65.1%, Ca8-P 17.8%-25.0%, and Ca2-P 4.66%-9.20%. The forms of Al-P, Fe-P, and O-P accounted for only 8.9%-18.6%. The formation of Ca10-P precipitates was considered to be the main mechanism of phosphate removal in the thermally modified slag bed.

Flocculation of Microcystis aeruginosa using modified larch tannin.

To flocculate the cyanobacterium Microcystis aeruginosa from water, larch tannin, a natural polymer, was modified by Mannich reaction to obtain a flocculant, named A-TN, which was then quaternized to yield another flocculant, named Q-TN. A-TN and Q-TN were characterized by Fourier transform infrared spectra (FTIR) and zeta potential analysis. The effects of the flocculation parameters, e.g., dosage, pH, cell density, culture time, and extracellular organic materials, were studied. The results showed that Q-TN was effective under a wider range of pH values than A-TN and could work under a pH of 9.0, whereas A-TN could work only under a pH of 7.0. For algal samples with densities from 1 × 10(8) to 5 × 10(9) cells/L, the optimum dosages of Q-TN to achieve more than 90% removal efficiency ranged from 0.5 to 20 mg/L, and the optimum dosages had a good linear relationship with cell density. Furthermore, the required dosage of Q-TN clearly increased along with the algae culture time, most of which was consumed by the extracellular organic materials (EOM) excreted from the cells. The spectra of the three-dimensional excitation-emission matrix showed that 100% of simple aromatic proteins and 78.8% of protein-like substances in the EOM could be removed by Q-TN. However, Q-TN was less effective in humic/fulvic-like substance flocculation. Q-TN functioned to settle the algae cells and a large amount of their metabolites effectively.

Magnetic coagulation and flocculation of kaolin suspension using Fe3O4 with plant polyphenol self-assembled flocculants.

In this work, magnetic flocculant (Fe3O4@PP) was synthesized using plant polyphenol (PP) as a shaping ligand via in situ self-assembly. Characterization results revealed that Fe3O4@PP exhibited uniform particle size and excellent dispersibility with PP coating amount of 16.4 %. Experimental results suggested that Fe3O4@PP showed excellent turbidity removal efficiency in a wide pH range (3.0-10) and initial turbidity range (50-2000 NTU). Under the optimal conditions, Fe3O4@PP achieved 95.2 % of turbidity removal for simulated kaolin suspension and 96.9 % for actual wastewater. Fe3O4@PP exhibited excellent recycling and reusability properties, with high recycling efficiency of 93.3 % even after the fifth cycle. Microscopic observation revealed the formation process of magnetic flocs, involving particle aggregation, chain and cluster formation, and dense network aggregate formation. The structural characteristics and size of magnetic flocs were found to be significantly influenced by the combined effects of magnetic force, electric charge, van der Waals force, and functional groups on the surface of PP. The extended Deryaguin-Landau-Verwey-Overbeek models indicated that magnetic interactions were the primary mechanism for magnetic flocculation, accompanied by charge neutralization, adsorption bridging, sweeping, and net trapping.

Electrochemical degradation of azo dye using granular activated carbon electrodes loaded with bimetallic oxides.

The performance of granular activated carbon (GAC) loaded with different combinations of Fe, Co, Ni, Mn, and Ti was examined for the electrochemical degradation of an azo dye such as acid red B (AR-B). Among the bimetallic groups, the combination of Fe and Co exhibited the best degradation effect. X-ray diffraction and X-ray photoelectron spectroscopy revealed that the morphology of the catalyst is CoFe2O4, and scanning electron microscopy manifested that the catalyst is distributed on the GAC surface and holes. The initial pH, hydraulic retention time, and current intensively affected the decolourisation and degradation efficiencies of AR-B, while the electrolyte types and concentrations did not exert any considerable effect. Electron spin resonance spectroscopy indicated that strong signals of hydroxyl radicals are produced by the Fe-Co/GAC electrodes. Results from fluorescence spectroscopy and gas chromatography-mass spectrometry suggested that hydroxyl radicals preferentially attack azo bonds during the degradation of AR-B, forming a series of compounds, and these compounds are finally degraded into small molecules of organic acids, carbon dioxide, and water.

Superhydrophobicity mechanism of refoliated quaking aspen leaves after complete defoliation by LDD (gypsy, spongy) moth caterpillars.

Complete defoliation of trees due to periodic LDD (Lymantria dispar dispar) moth outbreaks in many parts of the world is a significant stress factor for the survival of individual trees and entire forests over vast areas. This study addresses such a mid-summer defoliation event in Ontario, Canada for quaking aspen trees during 2021. It is shown that complete refoliation in the same year is possible for these trees, albeit with significantly smaller leaf size. Regrown leaves showed the well-known non-wetting behaviour typically observed for the quaking aspen tree without a defoliation event. These leaves have the same hierarchical dual-scale surface structure consisting of nanometre-size epicuticular wax (ECW) crystals superimposed on micrometre-sized papillae. This structure provides for the Cassie-Baxter non-wetting state with a very high water contact angle on the adaxial surface of the leaves. Subtle differences in the leaf surface morphology of the refoliation leaves compared with the regular growth leaves are likely due to environmental factors such as seasonal temperature during the leaf growth period after budbreak.

Drug-coated balloons for treating de novo lesions in large coronary vessels: A case report.

BACKGROUND: Percutaneous transluminal coronary angioplasty, while an effective intervention, can frequently lead to acute occlusion with severe consequences. Although clinical trials have demonstrated the efficacy of drug-coated balloons (DCB) in treating acute coronary artery occlusion and in preventing restenosis, there has been limited exploration on the use of DCB in treating de novo lesions in large vessels. Currently, DCB are only recommended for patients with small vessel lesions and in-stent restenosis lesions, those at high risk of bleeding, and other special groups of patients. CASE SUMMARY: This report presents a case of successful drug-coated balloon treatment of de novo lesions in large coronary vessels. Postoperatively, the patient demonstrated favorable recovery, with subsequent examination results revealing no significant differences from the previous examination. CONCLUSION: The successful treatment of the patient in our case highlights the potential of DCB in the treatment of de novo lesions in large coronary vessels.