Search

Flexible wearable devices have proven to be emerging tools for motion monitoring, personal healthcare, and rehabilitation training. The development of a multifunctional, flexible sensor and the integration of sensors and a smart chip for signal reading and transmission play a critical role in building a smart wearable device. In this work, a smart glove based on multiwalled carbon nanotubes/poly(dimethylsiloxane) (MWNTs/PDMS) fibers is developed for gesture and temperature recognition. First, the well-tunable, stretchable, and thermal-sensitive MWNTs/PDMS fibers are fabricated via a facile and cost-effective one-step extrusion method. The obtained fibers exhibit an outstanding linear relationship between resistance change and strain in the range of 0-120% and excellent cyclic stability and durability after 20 000 cycles of 50% tension. They also present a linear relationship of resistance change and temperature of 0.55% °C

The application of cable bolts tends to increase in both underground mining operations and civil tunnel excavations have given its outstanding performance to support the excavation surface and hence minimise the hazards and risk of failure in the field. Understanding the mechanical behaviour of cable bolts under axial loading subjected to different field environment from analytical perspective is essential and economic for selecting the most appropriate cable bolt for a specific scenario and also the ground support system design. This study develops a novel analytical model coupling the crack propagation in the grout annulus to capture the load–displacement performance of cable bolts under axial loading. The majority of the input parameters associated with mechanic properties of the cable bolt and grout are readily determinable by laboratory tests. Additionally, the model simulates the ongoing varying conditions of the confinement to the grouted cable bolt during the pull-out test based on the proposed crack propagation equation, leading to a more realistic reflection of the field conditions. Finally, the capability of the proposed model to simulate the performance of cable bolts under axial loading is demonstrated by validating against experimental results in the literature.

Background Prenatal stress (PRS) is considered a risk factor for depressive disorder. Adult hippocampal neurogenesis is believed to play a role in the regulation of affective behaviors. GABAergic interneuron is a key modulator in adult hippocampal neurogenesis. Growing evidence indicates that PRS has adverse effects on adult hippocampal neurogenesis and DNA epigenetic modifications of the GABAergic system. The aim of this study was to investigate whether epigenetic GABAergic dysfunction participates in the negative impact of PRS on adult hippocampal neurogenesis and related emotional behaviors. Methods Behavioral tests were used to explore PRS-induced depression-like behaviors of adult female mice. Immunohistochemistry staining, real-time reverse transcription-polymerase chain reaction, western blot, and chromatin immunoprecipitation were employed to detect adult neurogenesis and epigenetic changes of the GABAergic system in the hippocampus of PRS mice. Results PRS mice developed a depression phenotype accompanied by the inhibited maturation of hippocampal newborn neurons. Compared with control mice, PRS mice showed decreased expression of glutamic acid decarboxylase 67 at the mRNA and protein levels. GABAA receptor agonist phenobarbital could rectify the decrease of 5-bromo-2-deoxyuridine/neuronal nuclei double-positive (BrdU+/NeuN+) cells in PRS mice. PRS mice also showed increased expression of DNA methyltransferase 1 and increased binding of DNA methyltransferase 1 to glutamic acid decarboxylase 67 promoter region. The treatment with DNA methyltransferase 1 inhibitor 5-aza-deoxycytidine restored the decrease of BrdU+/NeuN+ cells and depression-like behaviors in PRS mice via improving GABAergic system. Conclusions The present results indicate that epigenetic changes of the GABAergic system are responsible for adult hippocampus neurogenesis and depression-like behaviors in PRS mice.

For rock fractures, the degradations in the strength of contacting asperities and the surface frictional resistance are responsible for the water-induced weakening in the shear strength. To quantitatively examine their independent roles, direct shear tests on sawtooth fracture samples of granite and sandstone under three moisture conditions: dry, surface wet and saturated, were conducted subject to three levels of normal stresses. The surface wet condition only resulted in the variation in the basic friction angle and the saturated samples underwent the degradation in both unconfined compressive strength (UCS) and basic friction angle, which were obtained via unconfined compression test and direct shear test, respectively. Two weakening coefficients that represent the reductions in UCS and basic friction angle, respectively, were proposed and incorporated into an analytical model, which quantifies the entire shear stress evolutions during shear based on a continuous yielding mechanism. The difference in the shear strength between dry and surface wet conditions originates from the lubricant effect of water represented by the change in basic friction angle with a weakening coefficient less than 10% for both rocks. Under the saturated condition, the weakening coefficient of the UCS varies significantly from 15.17% for granite to 50.39% for sandstone. A series of datasets that characterize the reductions in UCS and basic friction angle induced by water were collected from the literature, which were then incorporated into the analytical model to estimate the general weakening trend in the shear strength of the common rocks in practices. For crystalline rocks, the water-mediated lubrication seems to be the primary mechanism reducing the shear strength, while for sedimentary rocks, the remarkable degradation in UCS may dominate the weakening mechanism. The quantified weakening coefficients and the revealed weakening behavior of various rocks can be directly linked to the fracture shear strength estimation in engineering design.

Over-fertilization could lead to nitrogen (N) losses and environmental risks, and the appropriate nitrogen fertilizer could reduce the nitrous oxide (N2O) emission and increase the N utilization of...

The Majiagou Bridge comprising four sub-bridges is adjacent to the Weiqiang coal mine, Yulin City, Shaanxi Province, China. The mining of the longwall panel No. 1307 may damage the Majiagou Bridge. In this study, we predicted the mining-induced bridge movements using the finite element method (FEM) to examine whether the progressive mining of the longwall panel will pose a negative impact on the Majiagou Bridge. We reconstructed detailed three-dimensional models of the four sub-bridges by considering the superstructures and substructures. The input mechanical properties of the strata are estimated by calibrating with available field monitoring data. Effect of traffic load on the bridge subsidence is also accounted. The numerical predictions are: (1) after the panel No. 1307 is mined, the maximum vertical and horizontal displacements of the four bridges are 61.2 mm and 84.8 mm respectively, which occur on the sub-bridge D that is closest to the longwall panel, (2) traffic load has much less pronounced effect on the Majiagou Bridge than that due to mining, and (3) the maximum tilt and horizontal strain of the sub-bridges are 3.42e−5 m/m and 2.19e−5 m/m, which occur on sub-bridge B and sub-bridge A, respectively. In terms of tilt, the Majiagou Bridge is safe whereas it is to be damaged in terms of horizontal movement that is more critical in causing structural damage. Therefore, we suggest that a reasonably wider protective coal pillar should be set if the panel No. 1307 is to be mined, to ensure the safety of the Majiagou Bridge.

Research on molecularly imprinted polymers (MIPs) has long been receiving much attention, but issues concerning the recognition mechanism and how the impact factors work are still far from clear. In this work, we studied the imprinting and recognition procedures from a new perspective. Two factors that have a major impact on the imprinting performance were studied separately: one is the functional groups (FGs) of the template and the other is the size of the template. A series of aggregation-induced emission molecules (AIEgens) was employed as the templates, and they were selected elaborately, one group of which having different functional groups with a similar size, while the other being different in molecular size. It was found that the MIP was inclined to combine with molecules with more effective functional groups or with smaller sizes. Meanwhile, the more ordered sites and the larger cavities in the polymers afforded the MIP with better adsorption performance. The binding energy (ΔE) and the mechanism at the molecular level between templates and polymers were analyzed by using density functional theory (DFT) calculations, and the results were consistent with experimental results in the aspect of the FG effect. In addition, the unique luminescence properties of AIEgens allow for visible observation of the change of the template within the polymer during preparation and rebinding processes. More importantly, quantification of template molecules during the adsorption process was fulfilled based on their solid-state fluorescence intensities, which opens a new door for AIEgen application. A comparison with the common method of UV-vis spectrometry revealed that solid-state fluorescence measurement has the advantages of direct detection, easy operation, a wide linear range and so on.

International audience; A novel turn-on fluorescent probe with barbituric acid as a unique recognition group has been rationally designed and synthesized using a facile method for detecting hydrazine. The 5-((7-(dimethylamino)-4,5-dihydronaphtho [1,2-b] thiophen-2-yl)methylene)pyrimidine-2,4,6 (1H,3H,5H)-trione (DPT) probe displays a large emission signal ratio variation (more than a 40-fold enhancement) in the presence of hydrazine under neutral conditions. Interestingly, a novel recognition mechanism based on a hydrazine-triggered addition-cyclisation-retro aldol was proposed and confirmed. Additionally, the DPT probe exhibits a low detection limit (5 × 10-8 M), applicable to the physiological pH range (3-12), a broad linear response range for hydrazine concentrations between 0 and 34 μM and a large Stokes shift (147 nm) for hydrazine detection in aqueous solution. Moreover, the DPT probe was successfully implemented for hydrazine imaging in vivo.

A novel electrochemical sensor for therapeutic drug monitoring (TDM) of antibiotic Zavicefta was developed in this work. The main components of Zavicefta are ceftazidime (CFZ) and avibactam (AVI), wherein CFZ can be oxidized directly on electrode surface, while AVI is non-electroactive. In order to realize the simultaneous detection of the two analytes on one sensor, we elaborately constructed a dual-template molecularly imprinted polymer (MIP) modified electrode with CFZ and AVI as the templates, and further developed a dual-signal strategy. During detection, due to the inhibition effect caused by rebinding of MIP to the targets, the peak current of probe ferricyanide ([Fe(CN)

Monitoring the liver status in a convenient and low-cost way is significant for obtaining a warning about drug-indued liver diseases promptly. Herein, we designed a novel colorimetric point-of-care (POC) platform for the determination of three liver-related biomarkers─aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP). This platform integrated agarose hydrogels into a portable device, where hydrogels were loaded with nanozymes and different reaction substances for triggering specific reactions and generating colorimetric signals. Typically, Au-decorated CoAl-layered double oxide (Au/LDO) was for the first time developed as the nanozyme with peroxidase (POD) mimic activity, which can accelerate the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxTMB with the coexistence of hydrogen peroxide (H

This study aims to investigate the clinical efficacy of leuprorelin on ovarian function in premenopausal breast cancer (PBC) with positive Estrogen or Progesterone receptor. Forty receptor-positive PBC patients admitted to our hospital from January 2018 to October 2020 were randomized into control group and observation group, with 20 cases in each group. Tamoxifen and tamoxifen plus leuprorelin was respectively applied. The levels of bFSH and bAFC, total effective rate, survival rate at 6, 18 and 30 months, adverse reactions, the quality of life and activity of life scores were recorded and compared. After treatment, bFSH and bAFC in the observation group group were better. The total effective rate was 90.00% in the observation group and 55.00% in the control group. The survival rate of 18 and 30 months in the observation group was notably higher while the incidence of adverse reactions was lower. The quality of life score and activity of life score in the observation group were higher. Leuprorelin combined with endocrine drugs can obviously protect ovarian function with significant long-term effect, which effectively reduces the impact of adverse reactions on receptor-positive PBC patients, with higher safety and better feasibility.

Preeclampsia (PE) is a heterogeneous disease for which the current clinical classification system is based on the presence or absence of specific clinical features. PE-associated placentas also show heterogeneous findings on pathologic examination, suggesting that further subclassification is possible. We combined clinical, pathologic, immunohistochemical, and transcriptomic profiling of placentas to develop integrated signatures for multiple subclasses of PE. In total, 303 PE and 1388 nonhypertensive control placentas were included. We found that maternal vascular malperfusion (MVM) in the placenta was associated with preterm PE with severe features and with small-for-gestational-age neonates. Interestingly, PE placentas with either MVM or no histologic pattern of injury showed a linear decrease in proliferative (p63(+)) cytotrophoblast per villous area with increasing gestational age, similar to placentas obtained from the nonhypertensive patient cohort; however, PE placentas with fetal vascular malperfusion or villitis of unknown etiology lost this phenotype. This is mainly because of cases of fetal vascular malperfusion in placentas of patients with preterm PE and villitis of unknown etiology in placentas of patients with term PE, which are associated with a decrease or increase, respectively, in the cytotrophoblast per villous area. Finally, a transcriptomic analysis identified pathways associated with hypoxia, inflammation, and reduced cell proliferation in PE-MVM placentas and further subclassified this group into extravillous trophoblast-high and extravillous trophoblast-low PE, confirmed using an immunohistochemical analysis of trophoblast lineage-specific markers. Our findings suggest that within specific histopathologic patterns of placental injury, PE can be subclassified based on specific cellular and molecular defects, allowing the identification of pathways that may be targeted for diagnostic and therapeutic purposes.

In order to improve channel capacity of a communication system, a novel concept of all-fiber cylindrical vector beams (CVB) multiplexing through a mode-selective coupler (MSC) is proposed. According to the proposed concept, a step-index few-mode fiber (FMF) is also designed and fabricated for supporting the first-order CVBs (TE01 and TM01) propagation. In addition, for generating and multiplexing the mutually orthogonal TE01 and TM01, a novel mode-selective coupler with two inputs and one output is also proposed and manufactured by the pre-tapering technology, which can be considered to be the superposition of two independent MSCs with one input and one output. The corresponding theory analysis and simulation with respect to the MSC are performed to prove the validity of the proposed concept in principle. To verify the feasibility of the proposed concept in practice, a novel experimental setup is also proposed and established. The measured result agrees well with the simulation on the whole. Bit error rate (BER) and constellation graph (CG) are employed to evaluate the system performances of the proposed concept. The measured results demonstrate that the BER performance of TM01 (TE01) decreases with the increase of FMF length and data rate, respectively. In addition, compared to the case of only TM01 (TE01) propagation, the measured system performances seriously decline when TM01 and TE01 are multiplexed. The received power distributions demonstrate that the crosstalk among first-order vector modes increases with the increase of FMF length when TM01 (TE01) is excited and propagated. Some advanced technologies [with respect to fibers, fabrication, (de)coding, etc.] are also discussed, which can be employed to improve the system performance in the future.

IFNγ enhances allograft immunogenicity and facilitates T-cell mediated rejection. This may cause interstitial fibrosis and tubular atrophy (IFTA), contributing to chronic allograft loss. We assessed if inhibition of T-cell activation by N-octanoyl dopamine (NOD) impairs adherence of activated T-cells to endothelial cells and the ability of activated T-cells to produce IFNγ. We also assessed if NOD affects IFNγ mediated gene expression in endothelial cells. The presence of NOD during T-cell activation significantly blunted their adhesion to unstimulated and cytokine stimulated HUVEC. Supernatants of these T-cells displayed significantly lower concentrations of TNFα and IFNγ and were less capable to facilitate T-cell adhesion. In the presence of NOD VLA-4 (CD49d/CD29) and LFA-1 (CD11a/CD18) expression on T-cells was reduced. NOD treatment of IFNγ stimulated HUVEC reduced the expression of MHC class II transactivator (CIITA), of MHC class II and its associated invariant chain CD74. Since IFTA is associated with T-cell mediated rejection and IFNγ to a large extent regulates immunogenicity of allografts, our current data suggest a potential clinical use of NOD in the treatment of transplant recipients. Further in vivo studies are warranted to confirm these in vitro findings and to assess the benefit of NOD on IFTA in clinically relevant models.

Rapid and accurate monitoring of glucose, lactic acid, pyruvic acid, and 3-hydroxybutyric acid is essential in preventing, diagnosing, and treating diabetes, lactic acidosis and diabetic ketoacidosis. Herein, a novel sensing chip for multi-index determination of diabetes, lactic acidosis, and diabetic ketoacidosis was presented by integrating microfluidic device and photoelectrochemical (PEC) sensor. In order to block the interference from the reductive species in real samples, the PEC sensor was divided into a biocathode and a photoanode, which were installed separately in the upper and bottom layers of the device. The photoanodes were modified with ZnIn

Deep skin wound needs a long wound healing process, in which external force on skin around wound can result in a sharp pain, wound re-damage and interstitial fluid flowing out, increasing the risk of deterioration and even amputation. While the conventional wound dressings cannot provide timely feedback of abnormal wound status and lose best time for wound treatment, real-time monitoring wound status is thus urgently needed for wound management. In this work, a breathable and stretchable electronic skin (i.e., e-skin) named CNTs/graphene/GelMA mat has been developed through electrospinning, ice-templating and in-situ loading method for evaluating wound status. The obtained porosity, swelling ratio and vapor transmission rate of the CNTs/graphene/GelMA mat are 55 %, 180 % and 3378.2 h

Flexible sensors have attracted significant attention as they could be directly attached to/implanted into the body or incorporated into textiles to monitor human activities and give feedbacks for healthcare. A typical fabrication method is the direct use of intrinsically flexible active materials such as carbon nanotubes (CNTs). CNTs are generally assembled into aligned structures to extend their remarkable chemical, mechanical, and electrical properties to macroscopic scale to afford high sensing performances. In this review, we present the recent advance of CNT assemblies as electrodes or functional materials for flexible sensors. The realizations of aligned CNTs are firstly investigated. A variety of flexible sensors based on the aligned CNTs are then carefully explored, with an emphasis on understanding the working mechanism for their high sensing properties. The main attention is later paid to comparing two main categories of flexible sensors with fiber and film shapes. The remaining challenges are finally highlighted to offer some insights for future study.

To enhance the catalytic activity of two-dimensional layered materials as versatile materials, the modification of transition metal dichalcogenide nanosheets such as MoSThe online version contains supplementary material available at 10.1007/s10853-022-07201-z.

Currently, most of the electrochemical sensors were prepared based on the planar electrode (PE) and utilized in open circumstance. The accompanying issues include fixed and limited sensing area of PE, insufficient usage of the testing sample, tedious operation, and susceptibility to external environment. Herein, a novel tubular tip-like sensor (TTLS) platform was proposed, where a small tip accommodates all electrodes with a curved surface and also acts as a closed detection chamber. Teaming up with a commercial pipette and potentiostat, the TTLS is able to accomplish the whole assay procedure including sampling, detection, rinsing, and regeneration with a single hand. The electrochemical interface area can be easily tuned to adapting for different scenarios with varied sensitivity request. Moreover, two TTLS-based array systems were derived: one integrates multiple working electrodes in one tip for multicomponent quantification and the other assembles eight independent TTLSs for high-throughput analysis. The admirable sensing performance of the TTLS was fully proved by detecting several liver-related biomarkers in 5 μL of the serum sample. The proposed tubular sensor platform is superior to the traditional electrochemical sensor in the aspects of unique sensing surface, fast and simple operation, good portability, and great compatibility. The TTLS could be used as an ideal analytical tool in point-of-care testing and other fields.

Conductive hydrogels have attracted great attention due to their promising applications in wearable sensors. However, developing conductive hydrogels with excellent sensor properties and multiple stimulus responsive for smart wearable devices is still a challenge. This paper presents a facile synthetic method of a crosslinked chitosan quaternary ammonium salt and liquid metal (CHACC-LM) composite hydrogel with temperature-stress bimodal sensing for smart wearable sensor. LM as liquid fillers toughen the hydrogel matrix (stress: 1.11 MPa) and enhanced the hydrogel extensibility (strain: 233%). The CHACC-LM hydrogel exhibited conductivity (0.6 S/m), excellent antibacterial properties (> 99%), electrical self-healing property and strain sensitivity (GF = 1.6). In addition, the CHACC-LM hydrogel can be used as wearable flexible sensor with the ability of monitoring human activities directly and the distinguished ability of discerning subtle motions (handwriting). It also shown sensitivity in the external environment such as low temperature, thermal response and water solution. Importantly, the composite hydrogel also functioned under stress and different temperature stimuli owing to the existence of LM. Furthermore, the CHACC-LM hydrogel can be used for gesture recognition and to control the manipulator in human-computer interaction. All these properties provide great scope for researchers to achieve practical advances in smart wearable sensor. This article is protected by copyright. All rights reserved.

Over the past decade, a variety of carbon monoxide releasing molecules (CORMs) have been developed and tested. Some CORMs spontaneously release CO once in solution, while others require a trigger mechanism to release the bound CO from its molecular complex. The modulation of biological systems by CORMs depends largely on the spatiotemporal release of CO, which likely differs among the different types of CORMs. In spontaneously releasing CORMs, CO is released extracellularly and crosses the cell membrane to interact with intracellular targets. Other CORMs can directly release CO intracellularly, which may be a more efficient method to modulate biological systems. In the present study, we compared the efficacy of extracellular and intracellular CO-releasing CORMs that either release CO spontaneously or require an enzymatic trigger. The efficacy of such CORMs to modulate HO-1 and VCAM-1 expression in TNF-α-stimulated human umbilical vein endothelial cells (HUVEC) was evaluated.

Rock slope stability is commonly dominated by locked patches along a potential slip surface. How naturally heterogeneous locked patches of different properties affect the rock slope stability remains enigmatic. Here, we simulate a rock slope with two locked patches subjected to shear loading through a self-developed software, rock failure process analysis (RFPA). In the finite element method (FEM)-based code, the inherent heterogeneity of rock is quantified by the classic Weibull distribution, and the constitutive relationship of the meso-scale element is formulated by the statistical damage theory. The effects of mechanical and geometrical properties of the locked patches on the stability of the simulated rock slope are systematically studied. We find that the rock homogeneity modulates the failure mode of the rock slope. As the homogeneity degree is elevated, the failure of the locked patch transits from the locked patch itself to both the interfaces between the locked patched and the slide body and the bedrock, and then to the bedrock. The analysis of variance shows that length and strength of locked patch affect most shear strength and the peak shear displacement of the rock slope. Most of the rock slopes exhibit similar failure modes where the macroscopic cracks mainly concentrate on the interfaces between the locked patch and the bedrock and the slide body, respectively, and the acoustic events become intensive after one of the locked patches is damaged. The locked patches are failed sequentially, and the sequence is apparently affected by their relative positions. The numerically reproduced failure mode of the rock slope with locked patches of different geometrical and mechanical properties are consistent with the laboratory observations. We also propose a simple spring-slider model to elucidate the failure process of the rock slope with locked patches.

The transitional normal stress of a rock joint subject to shear refers to the critical normal stress under which the normal dilation is completely suppressed. The transitional normal stress is involved in many shear strength/constitutive models of joints as a key material constant; however, this parameter is poorly constrained and its determination is mostly empirical. Here we propose a simple formulation to predict the transitional normal stress based on the systematic, well-calibrated PFC2D (two-dimensional particle flow code) simulation of the shear characteristics of both sawtooth and JRC-profiled rock joints. In the PFC2D modelling, rock joints are confined by low to high normal stresses approximating the uniaxial compressive strength (joint wall compressive strength of fresh, dry and closely matched joints) of the simulated rock. The formulation can satisfactorily quantify the transitional normal stress of regular and irregular joint surfaces as a function of the rock strength and the joint surface roughness, as validated by the laboratory data. Therefore, it can be readily introduced to the shear strength criteria and constitutive models of rock joints, which could significantly promote the accurate quantification of rock joint shear behaviour.

In order to achieve wide field-of-view, high-resolution LIDAR, a gating imaging structure combining an electro-optic crystal and an electron multiplication CCD is constructed. According to the index ellipsoid theory, a 3D ray tracing model is established to explore the principle of electro-optic modulation. The field-of-view and interference intensity distribution of the LiNbO3(LN) crystal electro-optic modulation are studied by using the proposed model. In order to solve the problem that the interference light intensity at the edge of the field-of-view of crystal electro-optic modulation is not homogeneous, we study and propose an electro-optic modulation aberration correction algorithm based on phase difference compensation. The corrected interference light intensity at the edge of the field-of-view increased from 0.87 to 0.94. Finally, a LIDAR imaging simulation system is established to image the target at a distance of 2000 m. The results show that under the condition of a 1° wide field-of-view, the imaging accuracy of the system is 5 mm, and the average imaging error introduced by the crystal electro-optic modulation is less than 2 cm.

An iodine-mediated oxidative [4+1] cyclization of enamines with TMSN

Colorectal cancer (CC), as a malignancy threatening life and health, has a rising incidence in recent years. It has been reported that gambogic acid (GA) has antitumor activity in various tumors, but its effect on CC remains to be elucidated. In this investigation, the influence of GA nanoparticles on microRNA-199a-3p (miR-199a-3p) in CC was analyzed to provide a reliable reference for future clinical practice. Through PCR detection, we first determined that miR-199a-3p presented low expression in CC and had a significant effect in predicting the onset and prognosis of CC. Through in vitro experiments, the enhanced CC cell viability after inhibition was determined; however, decreased cell viability and increased miR-199a-3p level were also observed after GA nanoparticles addition. Hence, GA nanoparticles may influence CC cell biological behaviors by modulating miR-199a-3p, providing a novel treatment scheme for CC in the future.