Acoustic Vortex in Waveguide with Chiral Gradient Sawtooth Metasurface

The acoustic vortex states with spiral phase dislocation that can carry orbital angular moment (OAM) have aroused many research interests in recent years. The mainstream methods of generating acoustic vortex are based on Huygens-Fresnel principle to modulate the wavefront to create spatial spiral phase dislocation. In this work, we propose an entirely new scenario to generate acoustic vortex in a waveguide with chiral gradient sawtooth metasurface. The physical mechanism of our method is to lift the degenerate dipole eigenmodes through the scattering effect of the chiral surface structure, and then the superposition of them will generate both and order vortices in place. Compared to the existing methods of acoustic vortex production, our design has many merits, such as easy to manufacture and control, the working frequency is broadband, sign of vortex order can be readily flipped. Both the full-wave simulations and experimental measurements validate the existence of the acoustic vortices. The torque effect of the acoustic vortices is also successfully performed by rotating a foam disk as a practical application. Our work opens up a new route for generating acoustic vortex and could have potential significances in microfluidics, acoustic tweezers and ultrasonic communication, etc

The early variation of left ventricular twisting function in patients with lymphoma received anthracycline therapy assessed by three-dimensional speckle tracking echocardiography

Background: Anthracycline-induced cardiotoxicity remains a significant and unresolved issue in patients receiving chemotherapy. The aim of this study was to evaluate left ventricular (LV) twisting function by three-dimensional speckle tracking echocardiography (3D-STE) in patients with lymphoma after anthracycline therapy. Methods: One hundred and one patients with newly diagnosed diffuse large B-cell lymphoma who had planned to receive anthracycline chemotherapy were enrolled. LV apical rotation, basal rotation, twist, torsion, time to peak apical rotation and time to peak basal rotation were measured by 3D-STE at baseline, after the completion of two cycles and four cycles of the regimen, respectively. Apical–basal rotation delay was calculated as the difference between time to basal and time to apical rotation. Results: The results showed that LV apical rotation, basal rotation, twist and torsion declined progressively during the whole procedure (baseline vs. two and four cycles of the regimen, apical rotation: 12.5 ± ± 4.5° vs. 8.8 ± 3.6° vs. 6.0 ± 3.2°; basal rotation: –7.7 ± 3.0° vs. –5.9 ± 2.6° vs. –4.4 ± 2.5°; twist: 20.0 ± 6.4° vs. 14.5 ± 5.1° vs. 9.8 ± 4.5°; torsion: 2.9 ± 0.9°/cm vs. 2.1 ± 0.9°/cm vs. 1.4 ± 0.7°/cm; all p < 0.01). Furthermore, apical-basal rotation delay increased significantly after two cycles as well as after four cycles of the regimen (38.3 ± 67.9 ms vs. 66.7 ± 73.9 ms vs. 92.6 ± 96.9 ms; p < 0.01). Conclusions: LV twisting function deteriorated in the early stage of anthracycline therapy in patients with lymphoma, which could be detected by 3D-STE sensitively.

Effects of acid hydrolysis waste liquid recycle on preparation of microcrystalline cellulose

Large amounts of acidic waste are produced on the industrial scale during hydrolysis of partially amorphous cellulose to produce microcrystalline cellulose (MCC). The essential disposal and treatment of this highly acidic liquid wastes the acid feedstock and increases the production cost. To maximize the use of acid without sacrificing the MCC product quality, this project reports a successful attempt to recycle the acid hydrolysis waste liquid, focusing on the impact of waste recycling on MCC morphology and reducing sugar in the hydrolysate. The results showed that when the waste liquid is recycled 1-5 times, no metal accumulation occurred while cellulose particles remained intact, maintaining their shape and size. Their extent of crystallinity remained nearly constant, even increasing slightly with up to three cycles. The concentration of reducing sugar showed growth when recycling the waste liquid up to three times, although not quite to the levels that would allow for its cost-effective fermentation. The acid amount to be added at the start of each cycle was near 50% of that used on the first stage

Liver Toxicity of Rare Ginsenosides in Rats after 13 Weeks of Oral Exposure

Objective: This study aims to evaluate the hepatotoxicity of rare ginsenosides in rats after 90 days of oral administration using heat-transformed rare ginsenosides as the primary material. Methods: A total of 48 male and female rats were randomly assigned into four groups: High-dose rare ginsenosides (600 mg/kg), medium-dose rare ginsenosides (200 mg/kg), low-dose rare ginsenosides (60 mg/kg), and a blank control group. After 90 days of oral gavage treatment, ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) was employed for metabolomic analysis of rat serum and flow cytometry analysis of liver apoptosis to evaluate the potential liver damage comprehensively in rats. Results: A significant difference in hepatocyte apoptotic rate was observed between the high-dose group and the control group in both male and female rats (P0.05). However, 23 differential metabolites, such as histidine, glutamate, proline and arginine were identified in the serum of female rats in the high-dose group, affecting the histidine and urea cycle metabolic pathways and causing hyperammonemia and liver damage. Ten differential metabolites affecting the alpha-linolenic acid and linoleic acid metabolic pathways were found in male rats, such as linoleic acid and arachidonic acid. High concentrations of arachidonic acid showed inflammatory and toxic effects, which could be absorbed into the portal vein system through blood and cause liver damage. Conclusion: High-dose rare ginsenosides mainly cause slight liver damage in male and female rats mainly due to the changes of histidine, α-linolenic acid and linoleic acid metabolic pathways. Hence, no adverse liver effects were observed at doses less than 200 mg/kg in both male and female rats

Prognostic nomograms for predicting overall and cancer-specific survival of high-grade osteosarcoma patients

Aim: The present study aimed to develop nomograms estimating survival for patients with high-grade osteosarcoma. Methods: 1990 patients with high-grade osteosarcoma between 1994 and 2013 were retrospectively retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Data from 12 cancer registries (n = 1460) were used to conduct multivariate Cox analysis to identify independent prognostic factors. Nomograms which estimate 3- and 5-year overall survival (OS) and cancer-specific survival (CSS) were constructed. The nomograms were internally validated for calibration and were also externally validated with an independent patient cohort from 1 cancer registry (n = 530). Results: Age, primary site, tumor size, use of surgery, and extent of disease were found to be independently associated with OS and CSS (p < 0.05). The nomograms estimating 3- and 5-year OS and CSS were developed based on these prognostic factors. The concordance indices were high in internal validation (0.726 for OS and 0.731 for CSS) and external validation (0.716 for OS and 0.724 for CSS). Internal and external calibration plots demonstrated a good agreement between nomogram prediction and actual observation. Conclusions: We constructed nomograms that accurately predict OS and CSS of high-grade osteosarcoma patients. The nomograms can be used for counseling patients and establishing risk stratification. Keywords: Osteosarcoma, Prognostic factor, Survival, Nomogram, Validatio

Research on compound current control strategy based on LCL type active power filter

In view of contradiction between high steady state accuracy and fast dynamic response of traditional current control strategy, a novel compound current control strategy based on LCL type active power filter was proposed. The control strategy combines proportional integral control and repetitive control, the PI controller is used to ensure fast dynamic response, and further compensate control model to the stable system, which has good control characteristics in low frequency range; the repetitive controller is used to correct resonance peak and PI-inner-loop inherent phase lag of LCL filter, so as to realize fast tracking and high precision compensation on harmonic current of the power grid. The experiment results show that total harmonic distortion of the grid current is significantly reduced by compensating of shunt active power filter and the single-cycle fast response is achieved when the load changes, which verifies the compound current control strategy is effective

Characterizing Complexity Changes in Chinese Stock Markets by Permutation Entropy

Financial time series analyses have played an important role in developing some of the fundamental economic theories. However, many of the published analyses of financial time series focus on long-term average behavior of a market, and thus shed little light on the temporal evolution of a market, which from time to time may be interrupted by stock crashes and financial crises. Consequently, in terms of complexity science, it is still unknown whether the market complexity during a stock crash decreases or increases. To answer this question, we have examined the temporal variation of permutation entropy (PE) in Chinese stock markets by computing PE from high-frequency composite indies of two stock markets: the Shanghai Stock Exchange (SSE) and the Shenzhen Stock Exchange (SZSE). We have found that PE decreased significantly in two significant time windows, each encompassing a rapid market rise and then a few gigantic stock crashes. One window started in the middle of 2006, long before the 2008 global financial crisis, and continued up to early 2011. The other window was more recent, started in the middle of 2014, and ended in the middle of 2016. Since both windows were at least one year long, and proceeded stock crashes by at least half a year, the decrease in PE can be invaluable warning signs for regulators and investors alike