Rapid and multi-target genotyping of Helicobacter pylori with digital microfluidics.

Helicobacter pylori (H. pylori) infection correlates closely with gastric diseases such as gastritis, ulcers, and cancer, influencing more than half of the world's population. Establishing a rapid, precise, and automated platform for H. pylori diagnosis is an urgent clinical need and would significantly benefit therapeutic intervention. Recombinase polymerase amplification (RPA)-CRISPR recently emerged as a promising molecular diagnostic assay due to its rapid detection capability, high specificity, and mild reaction conditions. In this work, we adapted the RPA-CRISPR assay on a digital microfluidics (DMF) system for automated H. pylori detection and genotyping. The system can achieve multi-target parallel detection of H. pylori nucleotide conservative genes (ureB) and virulence genes (cagA and vacA) across different samples within 30 min, exhibiting a detection limit of 10 copies/rxn and no false positives. We further conducted tests on 80 clinical saliva samples and compared the results with those derived from real-time quantitative polymerase chain reaction, demonstrating 100% diagnostic sensitivity and specificity for the RPA-CRISPR/DMF method. By automating the assay process on a single chip, the DMF system can significantly reduce the usage of reagents and samples, minimize the cross-contamination effect, and shorten the reaction time, with the additional benefit of losing the chance of experiment failure/inconsistency due to manual operations. The DMF system together with the RPA-CRISPR assay can be used for early detection and genotyping of H. pylori with high sensitivity and specificity, and has the potential to become a universal molecular diagnostic platform.

Structural basis for the immune recognition and selectivity of the immune receptor PVRIG for ligand Nectin-2.

Nectin and nectin-like (Necl) co-receptor axis, comprised of receptors DNAM-1, TIGIT, CD96, PVRIG, and nectin/Necl ligands, is gaining prominence in immuno-oncology. Within this axis, the inhibitory receptor PVRIG recognizes Nectin-2 with high affinity, but the underlying molecular basis remains unknown. By determining the crystal structure of PVRIG in complex with Nectin-2, we identified a unique CC' loop in PVRIG, which complements the double-lock-and-key binding mode and contributes to its high affinity for Nectin-2. The association of the corresponding charged residues in the F-strands explains the ligand selectivity of PVRIG toward Nectin-2 but not for Necl-5. Moreover, comprehensive comparisons of the binding capacities between co-receptors and ligands provide innovative insights into the intra-axis immunoregulatory mechanism. Taken together, these findings broaden our understanding of immune recognition and regulation mediated by nectin/Necl co-receptors and provide a rationale for the development of immunotherapeutic strategies targeting the nectin/Necl axis.

Experimental study on evaluation of density, P-wave velocity, thermal conductivity, and thermal diffusion coefficient of granite after thermal treatments by using PCA.

Temperature significantly influences the physical parameters of granite, resulting in variations in the rock's thermal conductivity. In order to examine the impact of changes in multiple physical parameters of granite at different temperatures on the thermal conductivity of rocks, Principal Component Analysis (PCA) was employed to determine the correlation between granite at different temperatures and various physical parameters, including density (ρ), P-wave velocity (P), thermal conductivity (KT), and thermal diffusion coefficient (KD). Utilizing the linear contribution rate, a single indicator 'y' was derived to comprehensively represent the thermal conductivity of rocks. Research findings indicate that within the temperature range of 150-450 °C, the 'y'-value is relatively high, signifying favorable thermal conductivity of the rock. Notably, longitudinal wave velocity demonstrates higher sensitivity to temperature changes compared to other physical parameters.

Optoelectronically navigated nano-kirigami microrotors.

With the rapid development of micro/nanofabrication technologies, the concept of transformable kirigami has been applied for device fabrication in the microscopic world. However, most nano-kirigami structures and devices were typically fabricated or transformed at fixed positions and restricted to limited mechanical motion along a single axis due to their small sizes, which significantly limits their functionalities and applications. Here, we demonstrate the precise shaping and position control of nano-kirigami microrotors. Metallic microrotors with size of ~10 micrometers were deliberately released from the substrates and readily manipulated through the multimode actuation with controllable speed and direction using an advanced optoelectronic tweezers technique. The underlying mechanisms of versatile interactions between the microrotors and electric field are uncovered by theoretical modeling and systematic analysis. This work reports a novel methodology to fabricate and manipulate micro/nanorotors with well-designed and sophisticated kirigami morphologies, providing new solutions for future advanced optoelectronic micro/nanomachinery.

Transcriptomic data of BT549 triple negative breast cancer cells treated with 20 µM NU7441, a DNA-dependent kinase inhibitor.

DNA-dependent protein kinase catalytic subunit (DNA-PK) is a multifunctional serine­threonine protein kinase that plays roles in non-homologous end joining of DNA repair in cells. NU7441 is a specific DNA-PKcs inhibitor. We investigated the effects of NU7441 on the transcriptome of BT549 triple negative breast cancer cells. Total RNA extracted from NU7441-treated or control BT549 cells was processed for preparation of sequencing libraries. Assessment of read quality was performed using fastqc tool. Trimming and filtering low-quality reads were performed using fastp. Reads were aligned by hisat2. SAM files were converted to BAM files using Samtools. The gene differential expression analysis, Gene Ontology (GO) analysis and KEGG pathway analysis were performed. After NU7441 treatment, total number of 2045 differential genes were selected according to |log2(FoldChange)| >= 1 & padj<= 0.05, among which 1365 genes were down-regulated and 680 genes were up-regulated. The differential expression genes in pattern recognition receptors (PRRs) immune responses signals, including NOD-like receptor signaling, Toll-like receptor signaling, RIG-I-like receptor signaling and cytosolic DNA-sensing pathways were noted in this paper.

Effects of six teaching strategies on medical students: protocol for a systematic review and network meta-analysis.

INTRODUCTION: Mounting evidence has suggested that novel teaching strategies have a positive impact on the quality and efficiency of medical education. However, the comprehensive evidence about the superiority among various strategies is not clear. To address this issue, we aim to conduct a systematic review and network meta-analysis (NMA) to evaluate the effects of six main strategies on medical education, including case-based learning, problem-based learning, team-based learning, flipped classrooms, simulation-based education and bridge-in, objective, preassessment, participatory learning, postassessment and summary. METHODS AND ANALYSIS: A systematic search will be conducted in PubMed, Embase, Web of Science and the Cochrane Library, covering studies published from database inception to November 2023. Randomised controlled trials which evaluated the different teaching methods and meet the eligibility criteria will be included. The effectiveness of medical students' learning, which is evaluated by theoretical test score, experimental or practical test score, will be analysed as the primary outcomes. Besides, the secondary outcomes consist of learning satisfaction of students and formative evaluation score. The study selection and data extraction will be independently performed by two authors. The risk of bias in each study will be assessed using V.2 of the Cochrane risk-of-bias tool for randomised controlled trials. To compare the effects of six teaching strategies, pairwise meta-analysis and NMA will be performed using Rev Man, STATA and R software. Statistical analyses including homogeneity tests, sensitivity analysis, consistency tests, subgroup analysis, Egger's test and publication bias will also be completed. ETHICS AND DISSEMINATION: No formal research ethics approval is required because this study is a meta-analysis based on published studies. The results will be disseminated to a peer-reviewed journal for publication. PROTOCOL REGISTRATION NUMBER: CRD42023456050.

Comparative Study on Proton Conductivity and Mechanism Analysis of Two Imidazole Modified Imine-Based Covalent Organic Frameworks.

This work elucidates the potential impact of intramolecular H-bonds within the pore walls of covalent organic frameworks (COFs) on proton conductivity. Employing DaTta and TaTta as representative hosts, it was observed that their innate proton conductivities (σ) are both unsatisfactory and σ(DaTta)<σ(TaTta). Intriguingly, the performance of both imidazole-loaded products, Im@DaTta and Im@TaTta is greatly improved, and the σ of Im@DaTta (0.91×10-2  S cm-1 ) even surpasses that of Im@TaTta (3.73×10-3  S cm-1 ) under 100 °C and 98 % relative humidity. The structural analysis, gas adsorption tests, and activation energy calculations forecast the influence of imidazole on the H-bonded system within the framework, leading to observed changes in proton conductivity. It is hypothesized that intramolecular H-bonds within the COF framework impede efficient proton transmission. Nevertheless, the inclusion of an imidazole group disrupts these intramolecular bonds, leading to the formation of an abundance of intermolecular H-bonds within the pore channels, thus contributing to a dramatic increase in proton conductivity. The related calculation of Density Functional Theory (DFT) provides further evidence for this inference.

Ultrahigh Proton Conductivities of Postmodified Hf(IV) Metal-Organic Frameworks and Related Chitosan-Based Composite Membranes.

Recently, researchers have focused on preparing and studying proton exchange membranes. Metal-organic frameworks (MOFs) are candidates for composite membrane fillers due to their high crystallinity and structural characteristics, and Hf-based MOFs have attracted our attention with their high porosity and high stability. Therefore, in this study, Hf-based MOFs were doped into a cost-effective chitosan matrix as fillers to fabricate composite films having excellent proton conductivity (σ). First, the nanoscale MOFs Hf-UiO-66-(OH)2 (1) and Hf-UiO-66-NH2 (2) were chemically modified by a ligand design strategy to obtain SA-1 and CBD-2 bearing free -COOH units. The proton conductivities of SA-1 and CBD-2 under optimal test conditions reached 1.23 × 10-2 and 0.71 × 10-2 S cm-1. After that, we prepared composite membranes CS/SA-1 and CS/CBD-2 by the casting method; tests revealed that the introduction of MOFs improved the stabilities and σ values of the membranes, and their best σ could reach above 10-2 S cm-1 under 100 °C/98% RH. Further structural characterization and activation energy calculation revealed the conductive mechanism of the composite films. This investigation not only proposes a novel chemical modification method for optimizing the σ of MOFs but also promotes the development of MOF-doped composite membranes and provides a basis for future applications of MOFs in fuel cells.

Design, Preparation, and High Intrinsic Proton Conductivity of Two Highly Stable Hydrazone-Linked Covalent Organic Frameworks.

Assembling crystalline materials with high stability and high proton conductivity as a potential alternative to the Nafion membrane is a challenging topic in the field of energy materials. Herein, we concentrated on the creation and preparation of hydrazone-linked COFs with super-high stability to explore their proton conduction. Fortunately, two hydrazone-linked COFs, TpBth and TaBth, were solvothermally prepared by using benzene-1,3,5-tricarbohydrazide (Bth), 2,4,6-trihydroxy-benzene-1,3,5-tricarbaldehyde (Tp), and 2,4,6-tris(4-formylphenyl)-1,3,5-triazine (Ta) as monomers. Their structures were simulated by Material Studio 8.0 software and confirmed by the PXRD pattern, demonstrating a two-dimensional framework with AA packing. The presence of a large number of carbonyl groups as well as -NH-NH2- groups on the backbone is responsible for their super-high water stability as well as high water absorption capacity. AC impedance tests demonstrated a positive correlation between the water-assisted proton conductivity (σ) of the two COFs and the temperature and humidity. Under 100 °C/98% RH, the highest σ values of TpBth and TaBth can reach 2.11 × 10-4 and 0.62 × 10-5 S·cm-1, which are among the high σ values of the reported COFs. Their proton-conductive mechanisms were highlighted by structural analyses as well as N2 and H2O vapor adsorption data and activation energy values. Our systematic research affords ideas for the synthesis of proton-conducting COFs with high σ values.

A Versatile Continuum Gripping Robot with a Concealable Gripper.

Continuum robots with their inherent compliance provide the potential for crossing narrow unstructured workspace and safely grasping various objects. However, the display gripper increases the size of the robots, and therefore, it tends to get stuck in constrained environments. This paper proposes a versatile continuum grasping robot (CGR) with a concealable gripper. The CGR can capture large objects with respect to the robot's scale using the continuum manipulator and can grasp various objects using the end concealable gripper especially in narrow and unstructured workspaces. To perform the cooperative operation of the concealable gripper and the continuum manipulator, a global kinematic model based on screw theory and a motion planning approach referred to as "multi-node synergy method" for the CGR are presented. The simulation and experimental results show that objects of different shapes and sizes can be captured by the same CGR even in complex and narrow environments. Finally, in the future, the CGR is expected to serve for satellite capture in harsh space environments such as high vacuum, strong radiation, and extreme temperatures.

All-in-One digital microfluidics pipeline for proteomic sample preparation and analysis.

Highly sensitive and reproducible analysis of samples containing low amounts of protein is restricted by sample loss and the introduction of contaminants during processing. Here, we report an All-in-One digital microfluidic (DMF) pipeline for proteomic sample reduction, alkylation, digestion, isotopic labeling and analysis. The system features end-to-end automation, with integrated thermal control for digestion, optimized droplet additives for sample manipulation and analysis, and an automated interface to liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). Dimethyl labeling was integrated into the pipeline to allow for relative quantification of the trace samples at the nanogram level, and the new pipeline was applied to evaluating cancer cell lines and cancer tissue samples. Several known proteins (including HSP90AB1, HSPB1, LDHA, ENO1, PGK1, KRT18, and AKR1C2) and pathways were observed between model breast cancer cell lines related to hormone response, cell metabolism, and cell morphology. Furthermore, differentially quantified proteins (such as PGS2, UGDH, ASPN, LUM, COEA1, and PRELP) were found in comparisons of healthy and cancer breast tissues, suggesting potential utility of the All-in-One pipeline for the emerging application of proteomic cancer sub-typing. In sum, the All-in-One pipeline represents a powerful new tool for automated proteome processing and analysis, with the potential to be useful for evaluating mass-limited samples for a wide range of applications.

Steering Micromotors via Reprogrammable Optoelectronic Paths.

Steering micromotors is important for using them in practical applications and as model systems for active matter. This functionality often requires magnetic materials in the micromotor, taxis behavior of the micromotor, or the use of specifically designed physical boundaries. Here, we develop an optoelectronic strategy that steers micromotors with programmable light patterns. In this strategy, light illumination turns hydrogenated amorphous silicon conductive, generating local electric field maxima at the edge of the light pattern that attracts micromotors via positive dielectrophoresis. As an example, metallo-dielectric Janus microspheres that self-propelled under alternating current electric fields were steered by static light patterns along customized paths and through complex microstructures. Their long-term directionality was also rectified by ratchet-shaped light patterns. Furthermore, dynamic light patterns that varied in space and time enabled more advanced motion controls such as multiple motion modes, parallel control of multiple micromotors, and the collection and transport of motor swarms. This optoelectronic steering strategy is highly versatile and compatible with a variety of micromotors, and thus it possesses the potential for their programmable control in complex environments.

Design of a Fuel Explosion-Based Chameleon-Like Soft Robot Aided by the Comprehensive Dynamic Model.

Soft robotics have advantages over the traditional rigid ones to achieve the bending motion but face with challenges to realize the rapid and long-distance linear motion due to the lack of a suitable actuation system. In this paper, a new explosion-based soft robot is proposed to generate the axial fast extension by the explosion pressure. To support and predict the performance of this explosion-based soft robot, a novel dynamic model is developed by considering the change of working fluid (molecular numbers) and some unavoidable and influential factors in the combustion process. Then, based on the physical prototype, a set of experiments is conducted to test the performance of the explosion-based soft robot in performing the axial extensions, as well as to validate the model proposed in this article. It is found that the novel explosion-based soft robot can achieve rapid axial extension by the developed explosion-based actuation system. The explosion-based soft robot can achieve 41-mm displacement at a fuel mass of 180 mg. In addition, the proposed dynamic model can be validated with an average error of 1.5%. The proposed approach in this study provides a promising solution for future high-power density explosion-based soft robots.

A review on microrobots driven by optical and magnetic fields.

Due to their small sizes, microrobots are advantageous for accessing hard-to-reach spaces for delivery and measurement. However, their small sizes also bring challenges in on-board powering, thus usually requiring actuation by external energy. Microrobots actuated by external energy have been applied to the fields of physics, biology, medical science, and engineering. Among these actuation sources, light and magnetic fields show advantages in high precision and high biocompatibility. This paper reviews the recent advances in the design, actuation, and applications of microrobots driven by light and magnetic fields. For light-driven microrobots, we summarized the uses of optical tweezers, optoelectronic tweezers, and heat-mediated optical manipulation techniques. For magnetically driven microrobots, we summarized the uses of torque-driven microrobots, force-driven microrobots, and shape-deformable microrobots. Then, we compared the two types of field-driven microrobots and reviewed their advantages and disadvantages. The paper concludes with an outlook for the joint use of optical and magnetic field actuation in microrobots.

Creating stable trapping force and switchable optical torque with tunable phase of light.

Light-induced rotation of microscopic objects is of general interest as the objects may serve as micromotors. Such rotation can be driven by the angular momentum of light or recoil forces arising from special light-matter interactions. However, in the absence of intensity gradient, simultaneously controlling the position and switching the rotation direction is challenging. Here, we report stable optical trapping and switchable optical rotation of nanoparticle (NP)-assembled micromotors with programmed phase of light. We imprint customized phase gradients into a circularly polarized flat-top (i.e., no intensity gradient) laser beam to trap and assemble metal NPs into reconfigurable clusters. Modulating the phase gradients allows direction-switchable and magnitude-tunable optical torque in the same cluster under fixed laser wavelength and handedness. This work provides a valuable method to achieve reversible optical torque in micro/nanomotors, and new insights for optical trapping and manipulation using the phase gradient of a spatially extended light field.

Optoelectronic tweezers: a versatile toolbox for nano-/micro-manipulation.

The rapid development of micromanipulation technologies has opened exciting new opportunities for the actuation, selection and assembly of a variety of non-biological and biological nano/micro-objects for applications ranging from microfabrication, cell analysis, tissue engineering, biochemical sensing, to nano/micro-machines. To date, a variety of precise, flexible and high-throughput manipulation techniques have been developed based on different physical fields. Among them, optoelectronic tweezers (OET) is a state-of-art technique that combines light stimuli with electric field together by leveraging the photoconductive effect of semiconductor materials. Herein, the behavior of micro-objects can be directly controlled by inducing the change of electric fields on demand in an optical manner. Relying on this light-induced electrokinetic effect, OET offers tremendous advantages in micromanipulation such as programmability, flexibility, versatility, high-throughput and ease of integration with other characterization systems, thus showing impressive performance compared to those of many other manipulation techniques. A lot of research on OET have been reported in recent years and the technology has developed rapidly in various fields of science and engineering. This work provides a comprehensive review of the OET technology, including its working mechanisms, experimental setups, applications in non-biological and biological scenarios, technology commercialization and future perspectives.

Interaction between positive and negative dielectric microparticles/microorganism in optoelectronic tweezers.

Optoelectronic tweezers (OET) is a noncontact micromanipulation technology for controlling microparticles and cells. In the OET, it is necessary to configure a medium with different electrical properties to manipulate different particles and to avoid the interaction between two particles. Here, a new method exploiting the interaction between different dielectric properties of micro-objects to achieve the trapping, transport, and release of particles in the OET system was proposed. Besides, the effect of interaction between the micro-objects with positive and negative dielectric properties was simulated by the arbitrary Lagrangian-Eulerian (ALE) method. In addition, compared with conventional OET systems relying on fabrication processes involving the assembly of photoelectric materials, a contactless OET platform with an iPad-based wireless-control interface was established to achieve convenient control. Finally, this platform was used in the interaction of swimming microorganisms (positive-dielectric properties) with microparticles (negative-dielectric properties) at different scales. It showed that one particle could interact with 5 particles simultaneously, indicating that the interaction can be applied to enhance the high-throughput transportation capacities of the OET system and assemble some special microstructures. Owing to the low power, microorganisms were free from adverse influence during the experiment. In the future, the interaction of particles in a simple OET platform is a promising alternative in micro-nano manipulation for controlling drug release from uncontaminated cells in targeted therapy research.

Reconfigurable multi-component micromachines driven by optoelectronic tweezers.

There is great interest in the development of micromotors which can convert energy to motion in sub-millimeter dimensions. Micromachines take the micromotor concept a step further, comprising complex systems in which multiple components work in concert to effectively realize complex mechanical tasks. Here we introduce light-driven micromotors and micromachines that rely on optoelectronic tweezers (OET). Using a circular micro-gear as a unit component, we demonstrate a range of new functionalities, including a touchless micro-feed-roller that allows the programming of precise three-dimensional particle trajectories, multi-component micro-gear trains that serve as torque- or velocity-amplifiers, and micro-rack-and-pinion systems that serve as microfluidic valves. These sophisticated systems suggest great potential for complex micromachines in the future, for application in microrobotics, micromanipulation, microfluidics, and beyond.

Integrated Assembly and Photopreservation of Topographical Micropatterns.

Micromanipulation techniques that are capable of assembling nano/micromaterials into usable structures such as topographical micropatterns (TMPs) have proliferated rapidly in recent years, holding great promise in building artificial electronic and photonic microstructures. Here, a method is reported for forming TMPs based on optoelectronic tweezers in either "bottom-up" or "top-down" modes, combined with in situ photopolymerization to form permanent structures. This work demonstrates that the assembled/cured TMPs can be harvested and transferred to alternate substrates, and illustrates that how permanent conductive traces and capacitive circuits can be formed, paving the way toward applications in microelectronics. The integrated, optical assembly/preservation method described here is accessible, versatile, and applicable for a wide range of materials and structures, suggesting utility for myriad microassembly and microfabrication applications in the future.