Ultrasound-Responsive Systems as Components for Smart Materials.

Smart materials can respond to stimuli and adapt their responses based on external cues from their environments. Such behavior requires a way to transport energy efficiently and then convert it for use in applications such as actuation, sensing, or signaling. Ultrasound can carry energy safely and with low losses through complex and opaque media. It can be localized to small regions of space and couple to systems over a wide range of time scales. However, the same characteristics that allow ultrasound to propagate efficiently through materials make it difficult to convert acoustic energy into other useful forms. Recent work across diverse fields has begun to address this challenge, demonstrating ultrasonic effects that provide control over physical and chemical systems with surprisingly high specificity. Here, we review recent progress in ultrasound-matter interactions, focusing on effects that can be incorporated as components in smart materials. These techniques build on fundamental phenomena such as cavitation, microstreaming, scattering, and acoustic radiation forces to enable capabilities such as actuation, sensing, payload delivery, and the initiation of chemical or biological processes. The diversity of emerging techniques holds great promise for a wide range of smart capabilities supported by ultrasound and poses interesting questions for further investigations.

Code Similarity Prediction Model for Industrial Management Features Based on Graph Neural Networks.

The code of industrial management software typically features few system API calls and a high number of customized variables and structures. This makes the similarity of such codes difficult to compute using text features or traditional neural network methods. In this paper, we propose an FSPS-GNN model, which is based on graph neural networks (GNNs), to address this problem. The model categorizes code features into two types, outer graph and inner graph, and conducts training and prediction with four stages-feature embedding, feature enhancement, feature fusion, and similarity prediction. Moreover, differently structured GNNs were used in the embedding and enhancement stages, respectively, to increase the interaction of code features. Experiments with code from three open-source projects demonstrate that the model achieves an average precision of 87.57% and an F0.5 Score of 89.12%. Compared to existing similarity-computation models based on GNNs, this model exhibits a Mean Squared Error (MSE) that is approximately 0.0041 to 0.0266 lower and an F0.5 Score that is 3.3259% to 6.4392% higher. It broadens the application scope of GNNs and offers additional insights for the study of code-similarity issues.

Association of Alcohol Drinking and Helicobacter pylori Infection : A Meta-analysis.

BACKGROUND: The association between drinking and Helicobacter pylori infection was not clear in the literature. Owing to mixed and inconclusive results, a meta-analysis was conducted to summarize and clarify this association systematically. METHODS: Based on a comprehensive search of PubMed, Embase, and Web of Science databases, studies investigating the association between drinking and H. pylori infection were retrieved. We evaluated the strength of this relationship using odds ratios (ORs) with 95% confidence intervals. Sensitivity analysis was also conducted. RESULTS: A total of 24 individual studies were included in this meta-analysis. The risk of H. pylori infection was significantly lower in alcohol drinkers than nondrinkers (OR=0.83). People who drink wine (OR=0.90) or mixed types of alcoholic beverages (OR=0.78) had a lower risk of infection compared with those who drink beer. Among people aged 40 years or older, alcohol drinkers had a lower risk of H. pylori infection than nondrinkers (OR=0.68). Among people less than 40 years of age, alcohol drinking was not associated with H. pylori infection risk. Data showed that women were at a lower risk of H. pylori infection than men (OR=0.86). CONCLUSIONS: This meta-analysis suggests that the risk of H. pylori infection among alcohol drinkers is lower than that of nondrinkers. Drinking wine and mixed types of alcohol are better at reducing H. pylori infection than drinking beer. Nonetheless, we discourage reducing H. pylori infection through drinking, which increases the risk of other diseases.

16S full-length gene sequencing analysis of intestinal flora in breast cancer patients in Hainan Province.

Breast cancer has become the number one cancer in the world, and intestinal flora may be closely linked to it. Geographic location also has an important impact on human intestinal flora. We conducted the first study on the intestinal flora of breast cancer patients and non-breast cancer patients in a tropical region - Hainan Province in China. At the same time, Pacbio platform based on third-generation sequencing was used for the first time to conduct 16S full-length sequencing of fecal microorganism DNA. We completed the species diversity analysis and differential species analysis of the intestinal flora between the two groups, inferred their functional genetic composition and performed functional difference analysis. There were statistically significant differences in alpha diversity between the two groups in Hainan Province. By species composition difference analysis, at the phylum level, Bacteroidales (P = 0.006) and Firmicutes (P = 0.002) was differed between the two groups, and at the genus level, 17 breast cancer-related differential species such as Bacteroides were screened. According to the five grouping methods including ER level, PR level, HER2 status, Ki67 index and histological grade of breast cancer patients, 4, 1, 9, 6, 5 differential microbiota were screened out respectively, which were in total 25 (P < 0.05 for all subgroups) . The functional prediction and difference analysis revealed two functional metabolisms with significant differences between the two groups of microbes (P < 0.05). These results suggest that breast cancer is associated with changes in the composition and function of intestinal flora. These microflora and functional differences may become biomarkers or new targets for diagnosis and treatment of breast cancer.

Piezoelectric-Thermal Coupling Driven Biomimetic Stick-Slip Bidirectional Rotary Actuator for Nanomanipulation.

Substantial improvement of rotation driving accuracy is urgently needed and facing challenges. Miniature bidirectional rotary actuators with high-precision and controllable fallback rate require novel driving principles. Here, on the basis of a proposed biomimetic stick-slip motion principle, a novel piezoelectric-thermal coupling bidirectional rotary actuator was developed. The integrated mantis grasping leglike biomimetic claws and heating rods could realize the clockwise macroscopic rotation and anticlockwise macroscopic fallback of a cylindrical rotator, generated by piezoelectric stick-slip and thermal expansion, respectively. The rotation fallback was effectively inhibited at relatively lower frequencies and higher voltages, as a slight fallback rate of 0.095 was confirmed in term of 0.5 Hz and 80 V. An extraordinary piezoelectric-driven macroscopic rotation resolution of 0.2 µrad and thermal-induced microscopic resolution of 0.00073°/°C were experimentally revealed with the aid of real-time observation of the clockwise slow sticking and anticlockwise instantaneous slipping processes by using three-dimensional optical imaging.

Improving the Luminescence and Stability of Carbon-Centered Radicals by Kinetic Isotope Effect.

The kinetic isotope effect (KIE) is beneficial to improve the performance of luminescent molecules and relevant light-emitting diodes. In this work, the influences of deuteration on the photophysical property and stability of luminescent radicals are investigated for the first time. Four deuterated radicals based on biphenylmethyl, triphenylmethyl, and deuterated carbazole were synthesized and sufficiently characterized. The deuterated radicals exhibited excellent redox stability, as well as improved thermal and photostability. The appropriate deuteration of relevant C-H bonds would effectively suppress the non-radiative process, resulting in the increase in photoluminescence quantum efficiency (PLQE). This research has demonstrated that the introduction of deuterium atoms could be an effective pathway to develop high-performance luminescent radicals.

Amplification of Acoustic Forces Using Microbubble Arrays Enables Manipulation of Centimeter-Scale Objects.

Manipulation of macroscale objects by sound is fundamentally limited by the wavelength and object size. Resonant subwavelength scatterers such as bubbles can decouple these requirements, but typically the forces are weak. Here we show that patterning bubbles into arrays leads to geometric amplification of the scattering forces, enabling the precise assembly and manipulation of cm-scale objects. We rotate a 1 cm object continuously or position it with 15 µm accuracy, using sound with a 50 cm wavelength. The results are described well by a theoretical model. Our results lay the foundation for using secondary Bjerknes forces in the controlled organization and manipulation of macroscale structures.

A Systematic Review and Meta-Analysis of Risk Factors Associated with Severity and Death in COVID-19 Patients.

This meta-analysis aims to screen the risk factors for severe illness and death and provide help for early clinical treatment of the new coronavirus (COVID-19). Based on a comprehensive search of PubMed, Embase, and Web of Science databases, we included studies that explored the cause and risk factors for severe illness and death in COVID-19 patients. We evaluated the strength of this relationship using odds ratios (ORs) with 95% confidence intervals (CIs). A total of 17 articles were included; 16 of the 17 articles were from China, and the risk factors associated with severe illness and death were age, sex, and multiple comorbidities. Advanced age (≥65 years, severe illness, OR = 2.62; death, OR = 6.00), male (severe illness, OR = 1.49; death, OR = 1.54), chronic respiratory diseases (severe illness, OR = 5.67; death, OR = 3.72), diabetes (severe illness, OR = 3.27; death, OR = 2.60), hypertension (severe illness, OR = 3.08; death, OR = 3.53), chronic kidney disease (severe illness, OR = 3.59; death, OR = 5.38), and cardiovascular diseases (severe illness, OR = 3.87; death, OR = 4.91) were all risk factors. For COVID-19 patients, advanced age, male, and patients with chronic disease are at higher risk of developing severe illness or even death.

Submicron Particle Concentration and Patterning with Ultralow Frequency Acoustic Vibration.

Acoustofluidics have been widely used for particle and cell manipulations. Given the scaling of acoustic radiation forces and acoustic streaming flow velocities with increasing frequency, existing acoustofluidic manipulation of submicron particles require actuation at MHz and even GHz frequencies. In this work, we explore a novel acoustofluidic phenomenon, where an ultralow frequency (800 Hz) acoustic vibration is capable of concentrating and patterning submicron particles at two poles of each pillar in an array embedded in a microfluidic device. This unprecedented phenomenon is attributed to a collective effect of acoustic streaming induced drag force and non-Newtonian fluid induced elastic lift force, arising from symmetric acoustic microstreaming flows around each pillar uniformly across the entire pillar array. To our knowledge, this is the first demonstration that particles can be manipulated by an acoustic wave with a wavelength that is 6 orders of magnitude larger than the particle size. This ultralow frequency acoustofluidics will enable a simple and cost-effective solution to effective and uniform manipulation of submicron biological particles in large scales, which has the potential to be widely exploited in clinical and biomedical fields.

Association between inosine triphosphatase rs1127354 polymorphisms and ribavirin-induced anaemia and outcome in hepatitis C virus-infected patients: A meta-analysis.

WHAT IS KNOWN AND OBJECTIVES: The association between inosine triphosphatase (ITPA) rs1127354 polymorphisms in HCV-infected patients receiving ribavirin (RBV)-based therapy, and the risk of adverse drug reaction and outcomes is still unclear. A meta-analysis was conducted to summarize and clarify this association systematically. METHODS: A comprehensive search was performed in PubMed, Embase and Web of Sciences, and twenty-two studies were selected from the literature search. Pooled odds ratio (OR) and 95% confidence interval (95% CI) were estimated by either fixed- or random-effects models. RESULTS: Four outcomes were evaluated: (a) haemoglobin decline: significant associations with haemoglobin decline were found for rs1127354 CC VS CA + AA (OR = 10.59, 95% CI = 6.39-17.54); (b) severe anaemia: significant association with severe anaemia was observed for rs1127354 CC VS CA + AA (OR = 16.24, 95% CI = 6.21-42.43); (c) sustained virological response (SVR): CC genotype carriers had a decrease SVR during treatment (OR = 0.65, 95% CI = 0.52-0.81); (d) RBV dose reduction or stopping treatment: although statistical evidence of an association was found between the polymorphism and RBV dose reduction during treatment (OR = 1.80, 95% CI = 1.03-3.13), the sensitivity analysis suggested this result was not robust. WHAT IS NEW AND CONCLUSION: Patients with ITPA rs1127354 CC polymorphism are more likely to develop haemolytic anaemia, severe anaemia and decreased SVR. Testing for this genetic polymorphism may benefit patients.

Role of Exercise on Alleviating Pressure Overload-Induced Left Ventricular Dysfunction and Remodeling via AMPK-Dependent Autophagy Activation.

Cardiac hypertrophy is one of the significant risk factors that result in maladaptive cardiac remodeling and heart failure, and exercise is known to exert cardioprotection. In this research, the cardioprotective function and exercise mechanisms were explored.The rats underwent transverse aortic constriction (TAC) or a sham operation. The rats that received TAC were randomly assigned to five groups: (1) rats subjected to a sham operation as control group (SC), (2) rats that underwent TAC group (TC), (3) TAC and moderate-intensity exercise group (TE), (4) TE plus 3-MA group (TEM), and (5) TE plus Compound C group (TEC). The heart function was measured via echocardiography. Histological analysis and relative protein testing were conducted to analyze collagen deposition and apoptosis. Furthermore, western blot was employed to measure the protein expression of relevant signaling pathways. Impaired cardiac function, interstitial fibrosis, enhanced apoptosis, and ER stress were observed in the TAC-induced left ventricular hypertrophy. Exercise attenuated TAC-induced cardiac dysfunction, interstitial fibrosis, and ER stress-related apoptosis. In addition, exercise significantly improved autophagy and upregulated AMPK phosphorylation. Furthermore, AMPK inhibitor Compound C repressed the activation of AMPK, and autophagy inhibitor 3-methyladenine reversed exercise-induced autophagy. All of these abolished the protection of exercise against cardiac dysfunction and fibrosis induced by TAC.Our results indicated that 4 weeks of treadmill exercise could alleviate pressure overload-induced LV dysfunction and remodeling via an autophagy-dependent mechanism, which was induced by enhancing autophagy through the activation of AMPK.

Submicron Particle Focusing and Exosome Sorting by Wavy Microchannel Structures within Viscoelastic Fluids.

Exosomes, submicron membrane vesicles (30-200 nm) secreted by almost all cells, containing significant information such as proteins, microRNAs and DNAs, are closely associated with disease diagnostic and prognostic tests for liquid biopsy in clinical practice. However, their inherently small sizes lead to great challenges for isolating them from complex body fluids with high-throughput and high-purity. In this work, a reverse wavy channel structure using viscoelastic fluids with the addition of biocompatible polymer was presented for elasto-inertial focusing and sorting of submicron particles and exosomes. The microfluidic periodically reversed Dean secondary flow generated by repeated wavy channel structures could facilitate particle focusing compared with traditional straight channels. Four differently sized fluorescent submicron spheres (1 µm, 500 nm, 300 and 100 nm) were used to study the focusing behavior under various conditions. We have achieved simple, high-throughput, and label-free sorting of exosomes with purity higher than 92% and recovery higher than 81%. This developed elasto-inertial exosome sorting technique may provide a promising platform in various exosome-related biological research and pharmaceutical applications.

Detachable Acoustophoretic System for Fluorescence-Activated Sorting at the Single-Droplet Level.

Droplet-based single-cell sequencing has emerged as a very powerful tool to study the cellular heterogeneity in diseased tissues for a variety of biological problems. However, the current droplet generation with a single particle and cell encapsulation is a random process and suffers from a low yield that is unable to fulfill the high-throughput analysis requirement. In this work, we present a new fluorescence-activated droplet sorting (FADS) system that can isolate single-cell droplets at high accuracy and high yield using a highly focused surface acoustic wave (HFSAW) with a beam width around 50 µm. The acoustic wave is locally coupled into the microfluidic channel for droplet sorting through a micropillar waveguide structure between the channel and the interdigitated transducer (IDT). This detachable acoustic sorting system allows the disposal of the microfluidic channel after a single use to avoid cross-contamination and keeps the expensive IDT device reusable. We have achieved rapid and accurate isolation of single-cell droplets with purity higher than 90% at ∼1 kHz sorting rate with three different encapsulation contents. In addition, with the uniformly produced droplet size at ∼40 µm, the present acoustic FADS system enables effective sorting of small particles down to submicrometer size, which is challenging for existing fluorescence-activated cell sorting systems.

Self-Aligned Acoustofluidic Particle Focusing and Patterning in Microfluidic Channels from Channel-Based Acoustic Waveguides.

Acoustic fields have been widely used for manipulation of particles and cells within microfluidic systems. In this Letter, we explore a novel acoustofluidic phenomenon for particle patterning and focusing, where a periodic acoustic pressure field is produced parallel to internal channel boundaries with the imposition of either a traveling or standing surface acoustic wave (SAW). This effect results from the propagation and intersection of edge waves from the channel walls according to the Huygens-Fresnel principle and classical wave fronts from the substrate-fluid interface. We demonstrate versatile control over this effect to produce both one- and two-dimensional acoustic patterning from one-dimensional SAW fields and its utility for continuous particle focusing. Uniquely, this channel-guided acoustic focusing permits the generation of robust acoustic fields without channel resonance conditions and particle focusing positions that are difficult or impossible to produce otherwise.

Active optical modulator based on a metasurface in the terahertz region.

The characteristics of the electromagnetically induced transparency (EIT) analog exposed under different illumination powers have been investigated theoretically and experimentally. The EIT analog is composed of a fixed aluminum structure fabricated on the silicon substrate. It was found that the resonance degree of the transparent window displayed a decreasing trend, and a blueshift phenomenon emerged by increasing the powers of the laser. Similarly, the properties of the time delay under different illumination powers have also been researched. The realization of the tuning effect may provide a possible choice for the modulation of the slow light devices.

Assessment of the Link between XRCC1 Arg399Gln Polymorphism and Breast Cancer: a Meta-Analysis in a Single Ethnic Group.

BACKGROUND: Although various individual studies have been conducted to determine the association between X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism and breast cancer, the results remain inconclusive. To assess the influence of XRCC1 Arg399Gln polymorphism on the risk of breast cancer, a metaanalysis was performed in a single ethnic group. METHODS: Eligible studies were identified via databases such as PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure, and Chinese Biology Medicine, throughout February 2016. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strengths of the associations. RESULTS: Ten studies documenting a total of 4732 breast cancer cases and 5677 controls were included in this metaanalysis. The results indicated no significant association between XRCC1 Arg399Gln polymorphism and breast cancer risk in both total analysis and subgroup analysis stratified by geographical areas and source of controls. CONCLUSIONS: This meta-analysis provided evidence that XRCC1 Arg399Gln variant might not be risk alleles for breast cancer susceptibility in the Chinese population. Further studies conducted in other ethnic groups are required for definite conclusions.

Highly Localized Acoustic Streaming and Size-Selective Submicrometer Particle Concentration Using High Frequency Microscale Focused Acoustic Fields.

Concentration and separation of particles and biological specimens are fundamental functions of micro/nanofluidic systems. Acoustic streaming is an effective and biocompatible way to create rapid microscale fluid motion and induce particle capture, though the >100 MHz frequencies required to directly generate acoustic body forces on the microscale have traditionally been difficult to generate and localize in a way that is amenable to efficient generation of streaming. Moreover, acoustic, hydrodynamic, and electrical forces as typically applied have difficulty manipulating specimens in the submicrometer regime. In this work, we introduce highly focused traveling surface acoustic waves (SAW) at high frequencies between 193 and 636 MHz for efficient and highly localized production of acoustic streaming vortices on microfluidic length scales. Concentration occurs via a novel mechanism, whereby the combined acoustic radiation and streaming field results in size-selective aggregation in fluid streamlines in the vicinity of a high-amplitude acoustic beam, as opposed to previous acoustic radiation induced particle concentration where objects typically migrate toward minimum pressure locations. Though the acoustic streaming is induced by a traveling wave, we are able to manipulate particles an order of magnitude smaller than possible using the traveling wave force alone. We experimentally and theoretically examine the range of particle sizes that can be captured in fluid streamlines using this technique, with rapid particle concentration demonstrated down to 300 nm diameters. We also demonstrate that locations of trapping and concentration are size-dependent, which is attributed to the combined effects of the acoustic streaming and acoustic forces.

Detachable Acoustofluidic System for Particle Separation via a Traveling Surface Acoustic Wave.

Components in biomedical analysis tools that have direct contact with biological samples, especially biohazardous materials, are ideally discarded after use to prevent cross-contamination. However, a conventional acoustofluidic device is typically a monolithic integration that permanently bonds acoustic transducers with microfluidic channels, increasing processing costs in single-use platforms. In this study, we demonstrate a detachable acoustofluidic system comprised of a disposable channel device and a reusable acoustic transducer for noncontact continuous particle separation via a traveling surface acoustic wave (TSAW). The channel device can be placed onto the SAW transducer with a high alignment tolerance to simplify operation, is made entirely of polydimethylsiloxane (PDMS), and does not require any additional coupling agent. A microstructured pillar is used to couple acoustic waves into the fluid channel for noncontact particle manipulation. We demonstrate the separation of 10 and 15 µm particles at high separation efficiency above 98% in a 49.5 MHz TSAW using the developed detachable acoustofluidic system. Its disposability and ease of assembly should enable broad use of noncontact, disposable particle manipulation techniques in practical biomedical applications related to sample preparation.

Mechanical Properties Based Particle Separation via Traveling Surface Acoustic Wave.

Most microfluidics-based sorting methodologies utilize size differences between suspended micro-objects as the defining characteristic by which they are sorted. Sorting based on mechanical properties, however, would provide a new avenue for sample preparation, detection and diagnosis for a number of emerging biological and medical analyses. In this study, we demonstrate separation of polystyrene (PS) and poly(methyl methacrylate) (PMMA) microspheres based entirely on their difference in mechanical properties using traveling surface acoustic waves (TSAWs). We theoretically examine the correlation of the applied TSAW frequency, particle density and sound speed with respect to the resultant acoustic radiation force (ARF) that acts to translate particles, and experimentally corroborate these predictions by translating PS and PMMA particles simultaneously in a stationary flow. Even when PS and PMMA particles have the same diameters, they exhibit strongly nonlinear and distinct acoustophoretic responses as a function of their mechanical properties and the applied TSAW frequency. By specifically matching the appropriate acoustic frequency to the desired particle size, each particle population can be selectively translated and sorted. We demonstrate that this mechanical property based sorting can continuously separate these particle populations with at least 95% efficiency in the mixed 10/15 µm diameter PS and PMMA particle solutions tested.

Association Studies of CYP1A1 Exon7 Polymorphism and -GSTM1 Interaction with Esophageal Cancer Risk: a Meta-Analysis in the Chinese Population.

BACKGROUND: Although many epidemiological studies have investigated the CYP1A1 exon7 polymorphism and -GSTM1 interaction with esophageal cancer (EC), definite conclusions cannot be drawn. This study was conducted to explore this association in the Chinese population using meta-analysis. METHODS: Relevant studies were identified from PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure, and Chinese Biology Medicine databases published through August 2015. The association of CYP1A1 exon7 polymorphisms and EC risk was estimated by odds ratio (ORs) with 95% confidence intervals (CIs). In addition, the interaction between the CYP1A1 exon7 and GSTM1 genotypes was assessed. RESULTS: A total of 13 case-control studies including 1781 EC cases and 1996 controls were included in this metaanalysis. Overall, significantly increased EC risk was associated with the CYP1A1 exon7 polymorphism (G vs. A OR = 1.36, 95% CI = 1.14 - 1.64; GG vs. AA: OR = 1.85, 95% CI = 1.22 - 2.79; GG vs. AG: OR = 1.41, 95% CI = 1.01 - 1.96; GG + AG vs. AA: OR = 1.47, 95% CI = 1.28 - 1.68; GG vs. AA + AG: OR = 1.60, 95% CI = 1.10 - 2.31). In a subgroup analyses stratified by geographic areas, histopathology type and source of controls, the significant risk was found in hospital-based population, in South and North China. Analysis of CYP1A1- GSTM1 interaction did find synergistic interaction between these two genes. CONCLUSIONS: This meta-analysis provides the evidence that CYP1A1 exon7 polymorphism may contribute to the EC development in the Chinese population, and CYP1A1- GSTM1 interaction might elevate the risk.