SERS-based microdevices for use as in vitro diagnostic biosensors.

Advances in surface-enhanced Raman scattering (SERS) detection have helped to overcome the limitations of traditional in vitro diagnostic methods, such as fluorescence and chemiluminescence, owing to its high sensitivity and multiplex detection capability. However, for the implementation of SERS detection technology in disease diagnosis, a SERS-based assay platform capable of analyzing clinical samples is essential. Moreover, infectious diseases like COVID-19 require the development of point-of-care (POC) diagnostic technologies that can rapidly and accurately determine infection status. As an effective assay platform, SERS-based bioassays utilize SERS nanotags labeled with protein or DNA receptors on Au or Ag nanoparticles, serving as highly sensitive optical probes. Additionally, a microdevice is necessary as an interface between the target biomolecules and SERS nanotags. This review aims to introduce various microdevices developed for SERS detection, available for POC diagnostics, including LFA strips, microfluidic chips, and microarray chips. Furthermore, the article presents research findings reported in the last 20 years for the SERS-based bioassay of various diseases, such as cancer, cardiovascular diseases, and infectious diseases. Finally, the prospects of SERS bioassays are discussed concerning the integration of SERS-based microdevices and portable Raman readers into POC systems, along with the utilization of artificial intelligence technology.

Detecting Leadership Opportunities in Group Discussions Using Off-the-Shelf VR Headsets.

The absence of some forms of non-verbal communication in virtual reality (VR) can make VR-based group discussions difficult even when a leader is assigned to each group to facilitate discussions. In this paper, we discuss if the sensor data from off-the-shelf VR devices can be used to detect opportunities for facilitating engaging discussions and support leaders in VR-based group discussions. To this end, we focus on the detection of suppressed speaking intention in VR-based group discussions by using personalized and general models. Our extensive analysis of experimental data reveals some factors that should be considered to enable effective feedback to leaders. In particular, our results show the benefits of combining the sensor data from leaders and low-engagement participants, and the usefulness of specific HMD sensor features.

Unique Viscoelasticity and Hierarchical Relaxation Dynamics of Molecular Granular Materials.

Resulting from the dense packing of subnanometer molecular clusters, molecular granular materials (MGMs) are shown to maintain high elasticity far above their apparent glass transition temperature (Tg*). However, our microscopic understanding of their structure-property relationship is still poor. Herein, 1 nm polyhedral oligomeric silsesquioxanes (POSSs) are appended to a backbone chain in a brush configuration with different flexible linker chains. Assemblies of these brush polymers exhibit hierarchical relaxation dynamics with the glass transition arising from the cooperative dynamics of packed POSSs. The interaction among the assemblies can be strengthened by increasing the rigidity of linkers with the MGM relaxation modes changing from colloid- to polymer chain-like behavior, rendering their tunable viscoelasticity. This finally contributes to the decoupling of mechanical and thermal properties by showing elasticity dominant mechanical properties at a temperature 150 K above the Tg*.

Molecularly imprinted metal-organic frameworks assisted cloth and paper hybrid microfluidic devices for visual detection of gonyautoxin.

Marine algal toxin contamination is a major threat to human health. Thus, it is crucial to develop rapid and on-site techniques for detecting algal toxins. In this work, we developed colorimetric cloth and paper hybrid microfluidic devices (µCPADs) for rapid detection of gonyautoxin (GTX1/4) combined with molecularly imprinted polymers. In addition, the metal-organic frameworks (MOFs) composites were applied for this approach by their unique features. Guanosine serves as a dummy template for surface imprinting and has certain structural advantages in recognizing gonyautoxin. MOF@MIPs composites were able to perform a catalytic color reaction using hydrogen peroxide-tetramethylbenzidine for the detection of GTX1/4. The cloth-based sensing substrates were assembled on origami µPADs to form user-friendly, miniaturized colorimetric µCPADs. Combined with a smartphone, the proposed colorimetric µCPADs successfully achieved a low limit of detection of 0.65 µg/L within the range of 1-200 µg/L for rapid visual detection of GTX1/4. Moreover, the GTX1/4 of real shellfish and seawater samples were satisfactorily detected to indicate the application prospect of the µCPADs. The proposed method shows good potential in the low-cost, stable establishment of assays for the rapid detection of environmental biotoxins.

Adavosertib-encapsulated metal-organic frameworks for p53-mutated gallbladder cancer treatment via synthetic lethality.

Adavosertib (ADA) is a WEE1 inhibitor that exhibits a synthetic lethal effect on p53-mutated gallbladder cancer (GBC). However, drug resistance due to DNA damage response compensation pathways and high toxicity limits further applications. Herein, estrone-targeted ADA-encapsulated metal-organic frameworks (ADA@MOF-EPL) for GBC synthetic lethal treatment by inducing conditional factors are developed. The high expression of estrogen receptors in GBC enables ADA@MOF-EPL to quickly enter and accumulate near the cell nucleus through estrone-mediated endocytosis and release ADA to inhibit WEE1 upon entering the acidic tumor microenvironment. Ultrasound irradiation induces ADA@MOF-EPL to generate reactive oxygen species (ROS), which leads to a further increase in DNA damage, resulting in a higher sensitivity of p53-mutated cancer cells to WEE1 inhibitor and promoting cell death via conditional synthetic lethality. The conditional factor induced by ADA@MOF-EPL further enhances the antitumor efficacy while significantly reducing systemic toxicity. Moreover, ADA@MOF-EPL demonstrates similar antitumor abilities in other p53-mutated solid tumors, revealing its potential as a broad-spectrum antitumor drug.

Attention gate and dilation U-shaped network (GDUNet): an efficient breast ultrasound image segmentation network with multiscale information extraction.

Background: In recent years, computer-aided diagnosis (CAD) systems have played an important role in breast cancer screening and diagnosis. The image segmentation task is the key step in a CAD system for the rapid identification of lesions. Therefore, an efficient breast image segmentation network is necessary for improving the diagnostic accuracy in breast cancer screening. However, due to the characteristics of blurred boundaries, low contrast, and speckle noise in breast ultrasound images, breast lesion segmentation is challenging. In addition, many of the proposed breast tumor segmentation networks are too complex to be applied in practice. Methods: We developed the attention gate and dilation U-shaped network (GDUNet), a lightweight, breast lesion segmentation model. This model improves the inverted bottleneck, integrating it with tokenized multilayer perceptron (MLP) to construct the encoder. Additionally, we introduce the lightweight attention gate (AG) within the skip connection, which effectively filters noise in low-level semantic information across spatial and channel dimensions, thus attenuating irrelevant features. To further improve performance, we innovated the AG dilation (AGDT) block and embedded it between the encoder and decoder in order to capture critical multiscale contextual information. Results: We conducted experiments on two breast cancer datasets. The experiment's results show that compared to UNet, GDUNet could reduce the number of parameters by 10 times and the computational complexity by 58 times while providing a double of the inference speed. Moreover, the GDUNet achieved a better segmentation performance than did the state-of-the-art medical image segmentation architecture. Conclusions: Our proposed GDUNet method can achieve advanced segmentation performance on different breast ultrasound image datasets with high efficiency.

Sensing the Intentions to Speak in VR Group Discussions.

While virtual reality (VR) technologies enable remote communication through the use of 3D avatars, it is often difficult to foster engaging group discussions without addressing the limitations to the non-verbal communication among distributed participants. In this paper, we discuss a technique to detect the intentions to speak in group discussions by tapping into intricate sensor data streams from VR headsets and hand-controllers. To this end, we developed a prototype VR group discussion app equipped with comprehensive sensor data-logging functions and conducted an experiment of VR group discussions (N = 24). We used the quantitative and qualitative experimental data to analyze participants' experiences of group discussions in relation to the temporal patterns of their different speaking intentions. We then propose a sensor-based mechanism for detecting speaking intentions by employing a sampling strategy that considers the temporal patterns of speaking intentions, and we verify the feasibility of our approach in group discussion settings.

Supramolecular Complexation of Metal Oxide Cluster and Non-Fluorinated Polymer for Large-Scale Fabrication of Proton Exchange Membranes for High-Power-Density Fuel Cells.

Cost-effective, non-fluorinated polymer proton exchange membranes (PEMs) are highly desirable in emerging hydrogen fuel cells (FCs) technology; however, their low proton conductivities and poor chemical and dimension stabilities hinder their further development as alternatives to commercial Nafion®. Here, we report the inorganic-organic hybridization strategy by facilely complexing commercial polymers, polyvinyl butyral (PVB), with inorganic molecular nanoparticles, H3 PW12 O40 (PW) via supramolecular interaction. The strong affinity among them endows the obtained nanocomposites amphiphilicity and further lead to phase separation for bi-continuous structures with both inter-connected proton transportation channels and robust polymer scaffold, enabling high proton conductivities, mechanical/dimension stability and barrier performance, and the H2 /O2 FCs equipped with the composite PEM show promising power densities and long-term stability. Interestingly, the hybrid PEM can be fabricated continuously in large scale at challenging ~10 µm thickness via typical tape casting technique originated from their facile complexing strategy and the hybrids' excellent mechanical properties. This work not only provides potential material systems for commercial PEMs, but also raises interest for the research on hybrid composites for PEMs.

Protective effects of melatonin on DEHP-induced apoptosis and oxidative stress in prepubertal testes via the PI3K/AKT pathway.

Di(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, is one of the most common plasticizers and is widely used in various plastic products. DEHP induces apoptosis and oxidative stress and has been shown to have androgenic toxicity. However, the methods to combat DEHP-induced testicular damage and the mechanisms involved remain to be elucidated. In the present study, we used melatonin, which has strong antioxidant properties, to intervene in prepubertal mice and mouse Leydig cells (TM3) treated with DEHP or its metabolite mono(2-ethylhexyl) phthalate (MEHP). The results showed that melatonin protected against DEHP-induced testicular damage in prepubertal mice, mainly by protecting against DEHP-induced structural destruction of the germinal tubules and by attenuating the DEHP-induced decrease in testicular organ coefficients and testosterone levels. Transcriptomic analysis found that melatonin may attenuate DEHP-induced oxidative stress and apoptosis in prepubertal testes. In vitro studies further revealed that MEHP induces oxidative stress injury and increases apoptosis in TM3 cells, while melatonin reversed this damage. In vitro studies also found that MEHP exposure inhibited the expression levels of molecules related to the PI3K/AKT signaling pathway, and melatonin reversed this change. In conclusion, these findings suggest that melatonin protects against DEHP-induced prepubertal testicular injury via the PI3K/AKT signaling pathway, and provide a theoretical basis and experimental rationale for combating male reproductive dysfunction.

Spatiotemporal Studies of Soluble Inorganic Nanostructures with X-rays and Neutrons.

This Review addresses the use of X-ray and neutron scattering as well as X-ray absorption to describe how inorganic nanostructured materials assemble, evolve, and function in solution. We first provide an overview of techniques and instrumentation (both large user facilities and benchtop). We review recent studies of soluble inorganic nanostructure assembly, covering the disciplines of materials synthesis, processes in nature, nuclear materials, and the widely applicable fundamental processes of hydrophobic interactions and ion pairing. Reviewed studies cover size regimes and length scales ranging from sub-Ångström (coordination chemistry and ion pairing) to several nanometers (molecular clusters, i.e. polyoxometalates, polyoxocations, and metal-organic polyhedra), to the mesoscale (supramolecular assembly processes). Reviewed studies predominantly exploit 1) SAXS/WAXS/SANS (small- and wide-angle X-ray or neutron scattering), 2) PDF (pair-distribution function analysis of X-ray total scattering), and 3) XANES and EXAFS (X-ray absorption near-edge structure and extended X-ray absorption fine structure, respectively). While the scattering techniques provide structural information, X-ray absorption yields the oxidation state in addition to the local coordination. Our goal for this Review is to provide information and inspiration for the inorganic/materials science communities that may benefit from elucidating the role of solution speciation in natural and synthetic processes.

Distinct Circuits From the Central Lateral Amygdala to the Ventral Part of the Bed Nucleus of Stria Terminalis Regulate Different Fear Memory.

BACKGROUND: The ability to differentiate stimuli that predict fear is critical for survival; however, the underlying molecular and circuit mechanisms remain poorly understood. METHODS: We combined transgenic mice, in vivo transsynaptic circuit-dissecting anatomical approaches, optogenetics, pharmacological methods, and electrophysiological recording to investigate the involvement of specific extended amygdala circuits in different fear memory. RESULTS: We identified the projections from central lateral amygdala (CeL) protein kinase C δ (PKCδ)-positive neurons and somatostatin (SST)-positive neurons to GABAergic (gamma-aminobutyric acidergic) and glutamatergic neurons in the ventral part of the bed nucleus of stria terminalis (vBNST). Prolonged optogenetic activation or inhibition of the PKCδCeL-vBNST pathway specifically reduced context fear memory, whereas the SSTCeL-vBNST pathway mainly reduced tone fear memory. Intriguingly, optogenetic manipulation of vBNST neurons that received the projection from PKCδCeL neurons exerted bidirectional regulation of context fear, whereas manipulation of vBNST neurons that received the projection from SSTCeL neurons could bidirectionally regulate both context and tone fear memory. We subsequently demonstrated the presence of δ and κ opioid receptor protein expression within the CeL-vBNST circuits, potentially accounting for the discrepancy between prolonged activation of GABAergic circuits and inhibition of downstream vBNST neurons. Finally, administration of an opioid receptor antagonist cocktail on the PKCδCeL-vBNST or SSTCeL-vBNST pathway successfully restored context or tone fear memory reduction induced by prolonged activation of the circuits. CONCLUSIONS: Together, these findings establish a functional role for distinct CeL-vBNST circuits in the differential regulation and appropriate maintenance of fear.

Modular Toolbox as Snap Jewelry for Biomimetic Synthesis of Multifunctional Amino Acid Surfactants Inspired by Melanin.

Amino acid surfactants have gained significant importance in overcoming the limitations of conventional surfactants, notably, their low biocompatibility and biodegradability. However, the current amino acid surfactants lack multifunctional properties due to the nonreactivity of their aliphatic chains, necessitating the development of a new type of amino acid surfactant. A novel melanin-like amino acid surfactant and a biomimetic synthesis route were devised by mimicking the biosynthesis of melanin. Renewable natural polyphenol compounds with catechol moieties were utilized as building blocks for the hydrophobic group. In a proof-of-concept experiment, ethyl protocatechuate was oxidized to o-quinone and subsequently covalently linked to the amino group of lysine via Michael addition. The chemical structure was verified using liquid chromatography-tandem mass spectroscopy. The melanin-like amino acid surfactant exhibited excellent surface-active properties, with a critical micelle concentration of 1.59 mN m-1. Furthermore, it demonstrated remarkable emulsifying, foaming, solubilizing, dispersing, and wetting capabilities. Notably, it also possessed multifunctionality, including antibacterial activity, antioxidant activity, robustness, and mildness. These outstanding properties indicate significant potential for various applications. This strategy offers innovative insights and a versatile, modular toolbox for synthesizing multifunctional amino acid surfactants that mimic melanin. The approach allows for the easy interchange of o-quinone building blocks, which is akin to snap jewelry.

Spherical porous iron-nitrogen-carbon nanozymes derived from a tannin coordination framework for the preparation of L-DOPA by emulating tyrosine hydroxylase.

L-3,4-Dihydroxyphenylalanine (L-DOPA) is widely used in Parkinson's disease treatment and is therefore in high demand. Development of an efficient method for the production of L-DOPA is urgently required. Nanozymes emulating tyrosine hydroxylase have attracted enormous attention for biomimetic synthesis of L-DOPA, but suffered from heterogeneity. Herein, a spherical porous iron-nitrogen-carbon nanozyme was developed for production of L-DOPA. Tannic acid chelated with ferrous ions to form a tannin-iron coordination framework as a carbon precursor. Iron and nitrogen co-doped carbon nanospheres were assembled via an evaporation-induced self-assembly process using urea as a nitrogen source, F127 as a soft template, and formaldehyde as a crosslinker. The nanozyme was obtained after carbonization and acid etching. The nanozyme possessed a dispersive iron atom anchored in the Fe-N coordination structure as an active site to mimic the active center of tyrosine hydroxylase. The material showed spherical morphology, uniform size, high specific surface area, a mesoporous structure and easy magnetic separation. The structural properties could promote the density and accessibility of active sites and facilitate mass transport and electron transfer. The nanozyme exhibited high activity to catalyze the hydroxylation of tyrosine to L-DOPA as tyrosine hydroxylase in the presence of ascorbic acid and hydrogen peroxide. The titer of DOPA reached 1.2 mM. The nanozyme showed good reusability and comparable enzyme kinetics to tyrosine hydroxylase with a Michaelis-Menten constant of 2.3 mM. The major active species was the hydroxyl radical. Biomimetic simulation of tyrosine hydroxylase using a nanozyme with a fine structure provided a new route for the efficient production of L-DOPA.

The Coordination Nanocages-Integrated Polymer Brush Networks for Flexible Microporous Membranes with Exceptional H2 /CO2 Separation Performance.

The emergence of polymers with intrinsic microporosity provides solutions for flexible gas separation membranes with both high gas permeability and selectivity. However, their applications are significantly hindered by the costly synthetic efforts, limited availability of chemical systems, and narrow window of microporosity sizes. Herein, flexible mixed matrix membranes with tunable intrinsic microporosity can be facilely fabricated from the coordination assembly of polymer brushes and coordination nanocages. Polymer brushes bearing isophthalic acid side groups can coordinate with Cu2+ to assemble into polymer networks crosslinked by 2 nm nanocages. The semi-flexible feature of the polymer brush and the high crosslinking density of the network prevent the network from collapsing during solvent removal and the obtained aerogels demonstrate hierarchical structure with dual porosity from the crosslinked polymer network and coordination nanocage, respectively. The porosity can be facilely tuned via the amount of Cu2+ by regulating the network crosslinking density and nanocage loadings, and finally, optimized gas separation that surpasses Robeson upper bound for H2 /CO2 can be achieved. The coordination-driven assembly protocol paves a new avenue for the cost-effective synthesis of polymers with intrinsic microporosity and the fabrication of flexible gas separation membranes.

Pre-activated nanoparticles with persistent luminescence for deep tumor photodynamic therapy in gallbladder cancer.

Phototherapy of deep tumors still suffers from many obstacles, such as limited near-infrared (NIR) tissue penetration depth and low accumulation efficiency within the target sites. Herein, stimuli-sensitive tumor-targeted photodynamic nanoparticles (STPNs) with persistent luminescence for the treatment of deep tumors are reported. Purpurin 18 (Pu18), a porphyrin derivative, is utilized as a photosensitizer to produce persistent luminescence in STPNs, while lanthanide-doped upconversion nanoparticles (UCNPs) exhibit bioimaging properties and possess high photostability that can enhance photosensitizer efficacy. STPNs are initially stimulated by NIR irradiation before intravenous administration and accumulate at the tumor site to enter the cells through the HER2 receptor. Due to Pu18 afterglow luminescence properties, STPNs can continuously generate ROS to inhibit NFκB nuclear translocation, leading to tumor cell apoptosis. Moreover, STPNs can be used for diagnostic purposes through MRI and intraoperative NIR navigation. STPNs exceptional antitumor properties combined the advantages of UCNPs and persistent luminescence, representing a promising phototherapeutic strategy for deep tumors.

A strategy to enhance SERS detection sensitivity through the use of SiO2 beads in a 1536-well plate.

The development of rapid and accurate assays is crucial to prevent the rapid spread of highly contagious respiratory infections such as coronavirus (COVID-19). Here, we developed a surface-enhanced Raman scattering (SERS)-enzyme-linked immunosorbent assay (ELISA) method that allows for the screening of multiple patient samples with high sensitivity on a 1536-well plate. As the well number on the ELISA well plate increases from 96 to 1536, the throughput of the assay increases but the sensitivity decreases due to the low number of biomarkers and the increase in non-specific binding species. To address this problem, silica (SiO2) beads were used to increase the surface-to-volume ratio and the loading density of biomarkers, thereby enhancing sensitivity. Using a three-dimensional gold nanoparticle (AuNP)@SiO2 SERS assay platform on a 1536-well plate, an immunoassay for the nucleocapsid protein biomarker of SARS-CoV-2 was performed and the limit of detection (LoD) decreased from 273 to 7.83 PFU/mL compared to using a two-dimensional assay platform with AuNPs. The proposed AuNPs@SiO2 SERS immunoassay (SERS-IA) platform is expected to dramatically decrease the false-negative diagnostic rate of the currently used lateral flow assay (LFA) or ELISA by enabling the positive diagnosis of patients with low virus concentrations.

Comparative Transcriptome Profiling Reveals Two WRKY Transcription Factors Positively Regulating Polysaccharide Biosynthesis in Polygonatum cyrtonema.

Polygonatum cyrtonema (P. cyrtonema) is a valuable rhizome-propagating traditional Chinese medical herb. Polysaccharides (PCPs) are the major bioactive constituents in P. cyrtonema. However, the molecular basis of PCP biosynthesis in P. cyrtonema remains unknown. In this study, we measured the PCP contents of 11 wild P. cyrtonema germplasms. The results showed that PCP content was the highest in Lishui Qingyuan (LSQY, 11.84%) and the lowest in Hangzhou Lin'an (HZLA, 7.18%). We next analyzed the transcriptome profiles of LSQY and HZLA. Through a qRT-PCR analysis of five differential expression genes from the PCP biosynthesis pathway, phosphomannomutase, UDP-glucose 4-epimerase (galE), and GDP-mannose 4,6-dehydratase were determined as the key enzymes. A protein of a key gene, galE1, was localized in the chloroplast. The PCP content in the transiently overexpressed galE1 tobacco leaves was higher than in the wild type. Moreover, luciferase and Y1H assays indicated that PcWRKY31 and PcWRKY34 could activate galE1 by binding to its promoter. Our research uncovers the novel regulatory mechanism of PCP biosynthesis in P. cyrtonema and is critical to molecular-assisted breeding.

Self-assembly of Au@AgNR along M13 framework: A SERS nanocarrier for bacterial detection and killing.

Self-assembled functional nanomaterials with electromagnetic hot spots are crucial and highly desirable in surface-enhanced Raman scattering (SERS). Due to its versatile biological scaffold, the M13 phage has been employed to produce novel nano-building blocks and devices. In this study, we propose a novel M13 phage-based SERS nanocarrier, that utilizes the pVIII capsid in M13 to conjugate Au@Ag core-shell nanorod (Au@AgNR) with linker carboxy-PEG-thiol (M13-Au@AgNR) and the pIII capsid to specifically target Escherichia coli (E. coli). The M13-Au@AgNR@DTTC (3,3'- diethylthiocarbocyanine iodide) SERS probe was used to detect E. coli in a concentration range of 6 to 6 × 105 cfu/mL, achieving a limit of detection (LOD) of 0.5 cfu/mL. The proposed SERS platform was also tested in real samples, showing good recoveries (92%-114.3%) and a relative standard deviation (RSD) of 1.2%-4.7%. Furthermore, the system demonstrated high antibacterial efficiency against E. coli, approximately 90%, as measured by the standard plate-count method. The investigation provides an effective strategy for in vitro bacteria detection and inactivation.

Real-time assay of invertase activity using isoquinolinylboronic acid as turn-on fluorescent sensor.

Invertase is the key enzyme involved in several crucial biological processes by hydrolyzing sucrose for production of glucose and fructose. Invertase plays important roles in the fields of food, pharmacy, cosmetics, biofuels, and agriculture. Detection of invertase activity is urgently necessary for scientific research and industrial processes. Herein, a continuous fluorometric method was developed for real-time detection of invertase activity. 8-Isoquinolinylboronic acid responded to fructose by formation of a fluorescent complex in turn-on manner, and served as a fluorescent sensor to selectively recognize fructose in ternary enzymatic mixture containing sucrose and glucose. The limit of detection (LOD) for fructose was 0.07 mM. Progress curve for fructose production was established by directly and continuously monitoring the fluorescence for invertase reaction with sucrose as substrate. Initial velocity was obtained to characterize invertase activity. LOD for invertase assay was 0.10 U·mL-1. Km and υmax for invertase were determined as 7.70 mM and 0.86 mM·min-1, respectively. Copper ion was demonstrated to inhibit the invertase activity with IC50 of 33.61 mM. Applicability in high-throughput screening for inhibitor was demonstrated. The proposed method allows for real-time, simple, and rapidly monitoring the invertase activity. It has a broad range of potential applications for kinetics and screening inhibitor.