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The global demand for dialysis among patients with end-stage kidney disease has surpassed the capacity of public healthcare, a trend that has intensified. While wearable artificial kidney (WAK) technology is seen as a crucial solution to address this demand, there is an urgent need for both efficient and renewable toxin-adsorbent materials to overcome the long-standing technological challenges in terms of cost, device size, and sustainability. In this study, we employed screening experiments for adsorbent materials, multimodal characterization, and Monte Carlo adsorption simulations to identify a synthetic self-assembly silicalite-1 zeolite that exhibits highly ordered crystal arrays along the [010] face (b-axis) direction, demonstrating exceptional adsorption capabilities for small molecular toxins such as creatinine and urea associated with uremia. Moreover, this metal-free, cost-effective, easily synthesized, and highly efficient toxin adsorbent could be regenerated through calcination without compromising the performance. The simulated toxin adsorption experiments and comprehensive biocompatibility verification position it as an auxiliary adsorbent to reduce dialysate dosages in WAK devices as well as a potential adsorbent for small-molecule toxins in dialysis. This work is poised to propel the development of next-generation WAK devices by providing siliceous adsorbent solutions for small-molecule toxins.

Radical-involved allylation reactions have emerged as a powerful platform for construction of carbon-carbon and carbonheteroatom bonds, facilitating the strategic incorporation of diverse allyl moieties. Nevertheless, this burgeoning field still faces ongoing challenges, including limitations of radical precursors and coupling partners, and difficulties in achieving enantiocontrol. Herein, we report for the first time a highly enantioselective radical allylation involving β-keto esters with vinyl cyclopropanes utilizing a synergistic dual photoredox/nickel catalysis under visible light irradiation. The mild and redox-neutral catalytic protocol demonstrates an extensive substrate compatibility and good functional tolerance, providing access to enantioenriched β-keto esters featuring quaternary α-stereocenter with good yields and high enantioselectivities. Preliminary mechanistic studies have uncovered that the success of the reaction hinges on the dual roles of nickel catalyst, including in situ formation of photoredox sensitive substrate/Ni complex and the ensuing asymmetric radical addition step.

Accurate and reliable detection of uracil-DNA glycosylase (UDG) activity is crucial for clinical diagnosis and prognosis assessment. However, current techniques for accurately monitoring UDG activity still face significant challenges due to the single input or output signal modes. Here, we develop a sequentially activated-dumbbell DNA nanodevice (SEAD) that enables precise and reliable evaluation of UDG activity through primer exchange reactions (PER)-based orthogonal signal output. The SEAD incorporates a double-hairpin structure with a stem containing two deoxyuridine (dU) sites for target recognition and two preblocked primer binding regions for target amplification and signal output. Upon UDG recognition of dU, the SEAD can be cleaved by apurinic/apyrimidinic endonuclease 1 (APE1), generating two different hairpins with exposed primer binding regions. These hairpins serve as templates to initiate the parallel PER, enabling the extending of two different amplification products: a long single-stranded DNA (ssDNA) with repetitive sequences and a short ferrocene-labeled ssDNA with complementary sequences. These products further self-assemble into DNA nano-strings in an orthogonal manner that act as an electrochemiluminescence signal switch, enabling precise detection of low-abundance UDG. This work develops a sequential input and orthogonal output strategy for accurately monitoring UDG activity, highlighting the significant potential in cancer diagnosis and treatment.

Self-activated multicolor phosphors are being used in more and more emerging fields. In order to explore the energy transfer between [NbO6]7- coordination groups and Sm3+ ions, a series of Ba3-ySmyTa1-xNbxGa3Si2O14 samples co-doped with Nb5+ and Sm3+ were prepared in this work, and the changes of luminous intensity under the condition of fixed Nb5+ concentration regulating Sm3+ concentration and fixed Sm3+ concentration regulating Nb5+ concentration were obtained respectively. By further fitting the emission decay curves of Sm3+ under two conditions, the decreasing average lifetime is obtained. Thermal stability tests of the samples also hinted the presence of such energy transfer. This regular change can provide a good reference for developing new self-activated phosphors.

Oral squamous cell carcinoma (OSCC) is the most common malignant tumour in the oral and maxillofacial region. Lactic acid accumulation in the tumour microenvironment (TME) has gained attention for its dual role as an energy source for cancer cells and an activator of signalling pathways crucial to tumour progression. This study aims to reveal the impact of lactate-related genes (LRGs) on the prognosis, TME, and immune characteristics of OSCC, with the ultimate goal of developing a novel prognostic model.

In this paper, diode-pumped SESAM mode-locked Tm:Lu2O3 lasers operating at 1942 nm and 1968 nm are reported. Two different emission wavelengths below 2 μm are realized by using two different kinds of SESAMs. Based on a GaSb-SESAM, the mode-locked Tm:Lu2O3 laser delivers femtosecond pulses at 1942 nm with the shortest pulse duration of 774 fs and a maximum average output power of 104 mW at an absorbed pump power of 3.82 W. With a GaInAs-SESAM, a pulse duration of 916 fs under a corresponding maximum average output power of 148 mW is achieved at 1968 nm at the same absorbed pump power of 3.82 W. To the best of our knowledge, this is the first report on femtosecond mode-locking of Tm:Lu2O3 lasers operating at wavelengths below 2 μm.

In this paper, a groundbreaking probe-type fiber optic biosensor, harnessing the surface plasmon resonance (SPR) effect enhanced by barium titanate glass microspheres, is unveiled for virus RNA detection. The multi-physics simulation was used to verify the sensitivity improvement achieved by introducing barium titanate microspheres on the surface of the optical fiber microspheres probe. Experiments confirmed this, pushing the sensor's limit to an impressive 6802 nm/RIU. Biomarker capture on the microsphere surface subtly alters the local refractive index, triggering a detectable SPR spectral shift. To showcase its prowess, the sensor tackled the reverse-transcribed complementary DNA (cDNA) of COVID-19 RNA. Chemical modification of the gold film and DNA hybridization technology ensured specific cDNA detection. The limit of detection for this target reached a remarkable 1.58 nmol/L. This sensor not only excels in virus RNA detection but also holds immense potential for diagnosing major diseases by pinpointing the concentrations of key biomarkers.

Cytochrome P450 (CYP) 4G subfamily is closely related to the synthesis of cuticular hydrocarbons, leading to the enhanced desiccation and insecticide resistance of pests. However, functions of CYP4Gs in larval integument development remain unknown in Spodoptera frugiperda(J. E. Smith) (Lepidoptera: Noctuidae), which is a major transboundary migratory pest and become a common pest in China. On the basis of the genome and transcriptome datasets of S. frugiperda, CYP4G74, CYP4G75, CYP4G108, and CYP4G109were identified, which contained the conserved domains of P450s and CYP4Gs. The spatial and temporal expression analysis showed that CYP4G74and CYP4G75were significantly highly expressed in adults and larval integuments, while CYP4G108and CYP4G109had low expressions in larval integuments. After silencing CYP4G74and CYP4G75by RNA interference, abnormal integument development occurred in larvae, some of which became smaller and dead, indicating important roles of CYP4G74and CYP4G75in the synthesis and development of integuments. The results clarify the functions of CYP4Gs in S. frugiperdaand provide potential targets for the control of this pest.Graphical Abstract

We demonstrate a d-dorbital hybrid concept to regulate the electronic structure of Co9S8via Mo doping for enhanced water splitting performance.

China has made great achievements in industrial development and is transforming into a powerful manufacturing country. Meanwhile, the industrial land scale is also expanding. However, whether industrial structure upgrading achieves the purpose of restraining industrial land expansion remains unanswered. By calculating the industrial land structure index (ILSI) and industrial land expansion scale (ILES), this study analyzed their temporal and spatial distribution characteristics at both regional and city levels from 2007 to 2020 in China. Results show that industrial land expansion presents a different trend in the four regions, the ILES in the eastern region is the largest, and the speed of industrial land expansion has declined since 2013, but it has gradually increased since 2016. The ILSI of the eastern and central regions is higher than that of the western and northeastern regions. Furthermore, a spatial Durbin model (SDM) has been established to estimate the spatial effect of industrial structure upgrading on industrial land expansion from 2007 to 2020. Notably, industrial structure upgrading has not slowed industrial land expansion. The eastern and western regions require a greater amount of industrial land while upgrading the industrial structure. The improvement of the infrastructure level and international trade level has promoted industrial land expansion.

Glycerol tributyrate as a low-density lipoprotein plays a crucial role in drug development and food safety. In this work, a novel high-stability fiber optic sensor for glyceryl tributyrate based on the poly(acrylic acid) (PAA) and chitosan (CS) composite hydrogel embedding method is first proposed. Compared with traditional functionalization, the lipase in a polymer network structure used in this article can not only avoid chemical reactions that cause damage to the enzyme structure but also avoid the instability of ionic bonds and physical adsorption. Therefore, the PAA/CS hydrogel method proposed in this article can effectively retain enzyme structure. First, the impact of different layers (one to five layers) of PAA/CS on pH sensing performance was explored, and it was determined that layers 1–3 could be used for subsequent sensing experiments. Within the linear detection range of 0.5–10 mM, the detection sensitivities of the one to three layers of the biosensor are divided into 0.65, 0.95, and 1.51 nm/mM, respectively, with the three layers having the best effect. When the number of coating layers is three, the detection limit of the sensor is 0.47 mM, meeting the millimole level detection standard for anticancer requirement. Furthermore, the stability and selectivity of the sensor (in the presence of hemoglobin, urea, cholesterol, acetylcholine, and glucose) were analyzed. The three-layer sensor is used for sample detection. At concentrations of 1–10 mM, the absolute value of the recovery percentage (%) is 82–99%, which can accurately detect samples. The sensor proposed in this paper has the advantages of low sample consumption, high sensitivity, simple structure, and label-free measurement. The enzyme-embedding method provides a new route for rapid and reliable glyceryl tributyrate detection, which has potential applications in food safety as well as the development of anticancer drugs.

The different generations of bearing steel are designed to withstand high temperatures, quick speeds, and heavy loads and meet the requirements of aviation, aerospace, and advanced equipment production. In this study, three generation bearing systems (Si3N4/GCr15, Si3N4/M50, and Si3N4/CSS-42L) with pentaerythritol ester lubricants were selected to investigate their friction behavior and evolutionary mechanisms from room temperature to 350 °C. The results indicate that the coefficient of friction (COF) values for all three systems initially decreased and then increased as the temperature increased. The COF of Si3N4/GCr15 was not more than 0.170 when the temperature did not exceed 150 °C. Furthermore, the wear rate of Si3N4/M50 and Si3N4/CSS-42L are 2.67 × 10−4 mm3·N−1·m−1and 2.04 × 10−4 mm3·N−1·m−1at 260 °C, which are only 15.4% and 11.8% of Si3N4/GCr15. This discrepancy can be attributed to the formation of metal oxides on the worn surface of Si3N4/M50 and Si3N4/CSS-42L, and was easier to form on the worn surface of CSS-42L. Therefore, the applicable temperature range for GCr15 usually below 150 °C and for Si3N4/M50 and Si3N4/CSS-42L, it was from 150 to 260 °C. These results disclose the friction behavior and mechanism of these three generation bearing steel are different, and can be a guideline to choose proper bearing steel in future situation.

As pivotal structural component, steels operating at high temperatures play a vital role in promoting the development of advanced equipment technology. Enduring and efficient lubricants are critical bottleneck for the construction of high-temperature frictional subsystems. Polydiethylsiloxane oil (PDES) significantly reduces the coefficient of friction (COF) (9.80–16.74 %) and wear rate (28.95–54.59 %) in the Si3N4–8Cr4Mo4V system without sulfur and phosphorus anti-wear additives at 250 °C. With only 1 wt% PDES, there is a remarkable 28.95 % wear rate reduction in the Si3N4–8Cr4Mo4V frictional system. The enhanced lubrication performance come from the Si–O tribofilm at lower PDES concentrations (1–15 wt%). Once exceeding a PDES concentration of 30 wt%, the as-formed Si–O tribofilm transitions to a Fe–Mo compound film, exhibiting superior friction reduction and wear resistance properties.

ABSTRACT Phase change materials (PCMs) can effectively adjust the temperature of asphalt pavement and have broad application prospects. Microencapsulated phase change materials (micro-PCMs) can solve the leaking problem of PCMs, [...]

The traditional method assesses the impact of fractures on electronics by calculating test results for many samples, which ignores variation in manufacturing parameters between individuals and does not accurately reflect the actual state. This article proposes a fracture analysis method for multilayer ceramic capacitors (MLCC) by the phase field because of complex structures and diverse manufacturing parameters. This method is based on Griffith’s theory, and the phase field to calculate crack expansion and fracture effects on the electric potential of MLCC is obtained. Finally, MLCC of packages 0603, 1210, and 2220 are studied as numerical examples of applications for investigation. Calculated results are consistent with tests, which verifies the accuracy of this method. In addition, the mechanism of the MLCC fracture on its electrical characteristics is given, and the impact of solder height and the internal electrode number on the fracture are analyzed using this method.

In this article, a radial-electromagnetic-force-harmonic-oriented design methodology is proposed to suppress motor vibration. In the proposed methodology, the radial-electromagnetic-force harmonics innovatively act as the effective bridge between structural field and vibration performance. And avoiding low-order and large-amplitude radial-electromagnetic-force harmonics is the premise of designing low-vibration permanent magnet (PM) motors. For extensive investigation, a 36-slot/8-pole interior PM (IPM) motor with different winding configurations and variable rotor parameters is chosen as a design example. Then, the vibration suppression methods of lowest nonzero spatial-order shifting in the stator system and dominant-harmonic-amplitude reduction in the rotor system are proposed. Next, the performances of the IPM motor are simulated for validating the proposed methodology. Finally, a prototype motor is fabricated and experimented. Both theoretical derivation and test results are presented to verify the validity of the motor and the proposed design methodology.

Seawater-flow- and -evaporation-induced electricity generation holds significant promise in advancing next-generation sustainable energy technologies. This method relies on the electrokinetic effect but faces substantial limitations when operating in a highly ion-concentrated environment, for example, natural seawater. We present herein a novel solution using calcium-based metal–organic frameworks (MOFs, C12H6Ca2O19·2H2O) for seawater-evaporation-induced electricity generation. Remarkably, Ca-MOFs show an open-circuit voltage of 0.4 V and a short-circuit current of 14 μA when immersed in seawater under natural conditions. Our experiments and simulations revealed that sodium (Na) ions selectively transport within sub-nanochannels of these synthetic superhydrophilic MOFs. This selective ion transport engenders a unipolar solution flow, which drives the electricity generation behavior in seawater. This work not only showcases an effective Ca–MOF for electricity generation through seawater flow/evaporation but also contributes significantly to our understanding of water-driven energy harvesting technologies and their potential applications beyond this specific context.

In this article, a tellurite fiber (TF) was fabricated into a microsphere structure via discharge and sequentially coupled with a multimode fiber and a single-mode fiber (SMF) to form a Fabry-Perot interferometer (FPI) sensor. Changes in temperature and hydraulic pressure cause the microsphere to deform, altering the interference length of reflected lights and establishing their dependency relationship. Experimental results showed that the proposed FPI sensor had temperature sensitivity of 157 pm/°C and hydraulic pressure sensitivity of 11.4 pm/MPa. In addition, repetitive experiments and stability tests were conducted, and the maximum relative standard deviation (RSD) was calculated to be $4.34\times 10^{-4}$ for temperature and $4.48\times 10^{-4}$ for hydra- ulic pressure. This FPI sensor is characterized by small size, compact structure, high sensitivity, long-term accuracy, and good stability and repeatability. All these features render it suitable for real-time temperature and hydraulic pressure monitoring in complex environments. In addition, the tellurite compositions can be adjusted to help adapt the FPI sensor to specific external environmental conditions, which provides valuable theoretical and technical insights for the development of high-performance sensing devices.

The rapid development of wearable electronic devices and the diversification of social needs urgently demand high-performance wearable pressure sensors capable of stable operation in special environments. In this article, a flexible pressure sensor composed of biphasic multidimensional hybrid conductive nanocomposites (CNCs) and surface microstructures was proposed. Changes of conductive path happened both at microscopic (CNC-induced) and macroscopic (microneedle-induced) levels, synergistically improving the sensor’s performance. The influence of conductive filler and surface microstructure on the sensitivity and sensing range of the sensor was systematically investigated, revealing the intrinsic connection between material property, geometric structure, and sensing performance, and yielding the optimal fabrication parameters. In addition to high sensitivity over large sensing range, the proposed sensor also provided a fast response time, was unaffected to temperature fluctuations, and exhibited good repeatability and environmental stability. To mimic human fingertip skin, a sandpaper template was used to create external microstructures on the lower electrode of the pressure sensor, enabling the recognition of object roughness and further expanding the sensor’s application range. Additionally, the sensor’s good waterproof property made it suitable for underwater applications. As a proof of concept, the sensor was employed for underwater activity detection and information transmission.

Ependymal cells line the wall of cerebral ventricles and ensure the unidirectional cerebrospinal fluid (CSF) flow by beating their motile cilia coordinately. The ependymal denudation or ciliary dysfunction causes hydrocephalus. Here, we report that the deficiency of regulator of G-protein signaling 22 (RGS22) results in severe congenital hydrocephalus in both mice and rats. Interestingly, RGS22 is specifically expressed in ependymal cells within the brain. Using conditional knock-out mice, we further demonstrate that the deletion of Rgs22 exclusively in nervous system is sufficient to induce hydrocephalus. Mechanistically, we show that Rgs22 deficiency leads to the ependymal denudation and impaired ciliogenesis. This phenomenon can be attributed to the excessive activation of lysophosphatidic acid receptor (LPAR) signaling under Rgs22-/-condition, as the LPAR blockade effectively alleviates hydrocephalus in Rgs22-/-rats. Therefore, our findings unveil a previously unrecognized role of RGS22 in the central nervous system, and present RGS22 as a potential diagnostic and therapeutic target for hydrocephalus.

Microwave ablation is a minimally invasive technique using microwave energy to heat and destroy abnormal cells in tumors, in which temperature monitoring is critical to achieve the desired thermal therapy effect while protecting surrounding healthy tissue. This article proposes for the first time using a surface plasmon resonance (SPR)-based temperature sensor for the real-time monitoring of tissue temperature changes during microwave ablation. The SPR sensor has the advantages of simple structure, low cost, large measurement range, and satisfactory sensitivity. The SPR sensor adopted a multimode fiber (MMF)–thin-core fiber (TCF)–MMF structure, yielding a sensitivity of $-1.781 \pm 0.031$ nm/°C in the range of $22~^{\circ }$ C– $94~^{\circ }$ C. Furthermore, a commercially available fiber Bragg grating (FBG) array sensor was used as a reference, confirming the effectiveness of the proposed SPR sensor in the application.

C2–C4shorter olefins, particularly ethylene and propylene, are crucial building blocks in modern petrochemical, polymer, and chemical industries. However, their predominant sourcing from fossil resources raises concerns due to increased awareness of carbon emissions and diminishing petroleum reserves. Therefore, a necessary shift towards sustainable resources is underway. The zeolite-catalyzed methanol-to-olefin (MTO) process, particularly over 8-MR zeolite/zeo-type materials, has gained industrial prominence in this context. If methanol strictly originated from renewable sources, then the MTO process would actively promote the “methanol economy”. Despite the advantages of zeolite/zeo-type materials, they encounter deactivation due to the accumulation of coke precursors, limiting their lifetime. While achieving high olefin selectivity in the MTO process is not challenging, improving the catalytic lifetime without compromising preferential olefin selectivity is crucial. To achieve this objective, various surface modification approaches, such as dealumination through acid etching, steaming, and constructing bifunctional catalytic systems, are applied to numerous 8-MR zeolite/zeo-type materials, including industrially operational MTO catalysts. Combining catalytic studies with advanced characterization methods, including under operando conditions, has enhanced MTO process efficiency by mitigating the formation of coke precursors. Ultimately, this study contributes to a deeper understanding of zeolite-catalyzed MTO processes, paving the way for more efficient and sustainable production of low-carbon olefins.

Stochastic processes (SPs) are widely used in many real-world fields, especially AI algorithms and models. A discrete-time Markov chain (DTMC) is a fundamental SP where the probability of each event depends only on the state attained in the previous event. DTMC is extensively used in signal processing and information theory, but the hardware generation of DTMC remains hindered by the difficulty in arbitrarily modulating the averaged dwell times (ADTs), i.e. the average time that the DTMC stays at one state. In this letter, we propose a two-step procedure to modulate the ADTs of a DTMC generated from single magnetic tunnel junction (MTJ), without being limited by additional restrictions such as a fixed ratio between the ADTs, widening the SP applications scope of the MTJ-based DTMC. This method has been verified via mathematical derivation and electrical characterization. The generation throughput and power consumption can also be conveniently modulated. This procedure provides a new hardware solution for the generation of stochastic signal in semiconductor IC chips.

A series arc fault can easily ignite the surrounding flammable objects, leading to safety hazards. Therefore, accurately detecting the arc fault is essential. However, the fault characteristic information carried by the current when series arc faults occur is easily masked by the so-called screening load. As a result, series arc faults are not easily detected. To address this problem, this article proposes an arc fault detection model based on ${L}2/{L}1$ norm and classification algorithm. ${L}2/{L}1$ norm is introduced to quantify the fluctuations in the current signal when an arc fault occurs, and then combined with some commonly used time domain indexes and frequency domain indexes to extract the features of the arc fault current. Next, the extracted features are filtered to create a high-quality dataset. Subsequently, a random forest model is constructed and the dataset is used to train and test the model. Finally, the parameters of the random forest model are optimized using the grid search method to obtain a highly accurate arc fault detection model. The effectiveness of the introduced feature is verified using the arc fault data under different loads. Meanwhile, the proposed method is tested and compared with seven commonly used machine learning methods, which reflects the superiority and accuracy of the proposed method.

A widely tunable third-harmonic generation (THG) in a mid-infrared step-index tellurite optical fiber was investigated in this work. By pumping a 3 cm-long tellurite optical fiber using an optical parametric oscillator with the pump wavelength of 1180~3500 nm, a tunable THG from 393 to 1167 nm was achieved. To the best of our knowledge, this is the broadest THG in the optical fiber. The THG conversion efficiency with different fiber lengths was investigated, which showed that the THG conversion efficiency decreased with the fiber length increasing. In addition, the third-harmonic (TH) signal pattern showed that it did not arise from phase matching between the fundamental mode of the pump and the higher-order mode of the TH signal, but rather resulted from the tellurite optical fiber’s high nonlinearity. It provides a unique pathway for the development of new light sources.

In this paper, a microfluidic sensor based on suspended core fiber (SCF) for detecting the concentration of human chorionic gonadotropin (hCG) has been presented and experimentally demonstrated. The sensor is made by splicing SCF between two sections of drawn-tapered single-mode fiber (SMF). The SCF is a multimode fiber that supports multi-mode optical transmission and generates mode interference in the fiber core. The air holes in the SCF can also be used as microcirculation channels for the sensor, enhancing the interaction between the detection sample and the light field and improving the refractive index (RI) sensitivity. Due to the closed microchannels, the sensor has good anti-interference and stability, can effectively prevent biological pollution. The sensitivity of RI is 1848 nm/RIU in the RI range of 1.3335-1.3419. The sensor can also detect local RI changes on the fiber surface due to biomolecule binding. The hCG antigen can specifically bind to the hCG-β antibody. The hCG-β antibody is immobilized in the air holes of the SCF to specifically detect the concentration of hCG. Experimental results showed that the sensor can specifically detect hCG concentration with a sensitivity of 1.888 nm/(mIU/ml) and a detection limit of 0.049 mIU/ml at a temperature of 25 °C. This sensor has good specificity and potential applications in medical diagnostics, drug testing, and tumor screening.

As a low-density lipoprotein, tributyrin plays a vital role in food safety and human health. In this work, we first proposed a novel high-performance tributyrin sensor made by supporting zeolitic imidazolate framework-8 (ZIF-8) and lipase onto the optic fiber sensor based on the surface plasmon resonance (SPR) principle. After adsorption of lipase within the ZIF-8 framework, through a rapid aqueous synthesis method, a thin and dense ZIF-8 film can be uniformly formed and stably and tightly bonded to the surface of the optical fiber sensor. ZIF-8 is one of the metal–organic frameworks (MOFs), which not only has the high porosity and specific surface area of MOFs, but also shows good affinity with lipase. The experimental results show that the proposed sensor can achieve the specific detection of tributyrin in the linear range of 0.1–3 mM, the sensitivity is 14.75 nm/mM, with a detection limit of 0.096 mM. The sensor proposed in this article for the first time using ZIF-8/lipase composite material to detect tributyrin has an accuracy of more than 83% in sample detection at the range of 0.1–3 mM. In addition, the stability test of the proposed sensor is as good as 0.47 nm, and the selectivity (in the presence of glycine, acetylcholine, glucose, and urea) of the sensor was analyzed. The sensor proposed in this article has the advantages of a low sample consumption of $100~\mu \text{L}$ , high sensitivity, simple structure, and label-free measurement. This method provides a new route for the rapid and reliable detection of tributyrin, which has potential applications in medical research and clinical diagnosis.

The development of flexible pressure sensors with ultraviolet (UV) shielding property is of great significance for outdoor activity monitoring devices. In this work, we propose a flexible pressure sensor based on polyacrylonitrile (PAN)/ TiO2/MXene nanofiber membrane by combining the electrospinning and dip-coating methods, and the addition of TiO2 nanoparticles (NPs) and MXene flakes greatly improves the UV-protective performance of the sensor. The high ultraviolet protection factor (UPF) of the proposed sensor is ~24716, and it has a relatively stable transmittance for UV light of different power. This UV-protective sensor not only shows excellent pressure sensitivity (0.15148 kPa−1) in a wide range of 350 kPa but also has excellent breathability as well as good cycle stability. The results show that the PAN/TiO2/MXene sensor has excellent UV protection performance and pressure sensing ability, which can be used for outdoor activity monitoring. It can monitor various sports conditions when people are outdoors, demonstrating broad application prospects in fields such as intelligent sports and wearable electronics.

Accurate detection of triglycerides (TGs) is important for the prevention and monitoring of dyslipidemia and for understanding the mechanisms of metabolic diseases. In this article, an ultrasensitive label-free sensor for measuring TGs based on an exposed-core optical fiber is presented. The sensor head was formed by splicing a single-mode optical fiber, a multimode optical fiber, and an exposed-core fiber in a Mach–Zehnder interferometer configuration. The Mach–Zehnder interference (MZI) occurs between the exposed core of the fiber, which is only micrometer in size, and the external environment. This allows the light path to pass directly through the liquid sample, resulting in an ultrahigh refractive index sensitivity of 13300 nm/RIU in the refractive index range of 1.331–1.332. In addition, lipase is immobilized on the optical fiber sensor to measure the concentration of TGs by detecting the change in the refractive index of the sample solution caused by the hydrolysis of TGs by lipase. The results showed that this sensor can specifically detect the concentration of TGs with a sensitivity of 1.72 nm/nM and a detection limit of 35 pM. It has the potential to revolutionize the diagnosis and monitoring of TGs and thus impact the prevention and treatment of dyslipidemia and other metabolic diseases.

Humans rely on their fingers to sense and interact with external environment. Understanding the tribological behavior between finger skin and object surface is crucial for various fields, including tactile perception, product appearance design, and electronic skin research. Quantitatively describing finger frictional behavior is always challenging, given the complex structure of the finger. In this study, the texture and sliding direction dependence of finger skin friction was quantified based on explicit mathematic models. The proposed double-layer model of finger skin effectively described the nonlinear elastic response of skin and predicted the scaling-law of effective elastic modulus with contact radius. Additionally, the skin friction model on textured surface considering adhesion and deformation factors was established. It revealed that adhesive term dominated finger friction behavior in daily life, and suggested that object texture size mainly influenced friction-induced vibrations rather than the average friction force. Combined with digital image correlation (DIC) technique, the effect of sliding direction on finger friction was analyzed. It was found that the anisotropy in finger friction was governed by the finger’s ratchet pawl structure, which also contributes to enhanced stick-slip vibrations in the distal sliding direction. The proposed friction models can offer valuable insights into the underlying mechanism of skin friction under various operating conditions, and can provide quantitative guidance for effectively encoding friction into haptics.

In this article, we propose and experimentally demonstrate a simple and low-cost fiber-optic sensor for temperature-independent ultraviolet (UV) detection. The sensor utilizes a photosensitive material, i.e., acrylic and hydrogenated epoxy resin, which is tightly wrapped around one end of a multimode optical fiber (MMF) and processed by light curing and heat curing. Upon absorbing UV radiation, the phosphor in the resin compound undergoes population inversion, resulting in the emission band around 480 nm, and the peak intensity of the emission band is positively correlated with the UV excitation intensity. The UV sensing characteristics of the sensor are experimentally investigated by tracking the photoluminescence peak intensity of the output spectrum, demonstrating a fast response of 0.1–0.2 s, high sensitivity of 315.78 (mW/cm2)−1, small absolute error within −0.28 to 0.42 mW/cm2, and good repeatability ( $R > $ 95%) and stability (RSD < 1.3%). In addition, the peak intensity is proved to be insensitive to temperature variation: as temperature varies from −20.5 °C to 56.3 °C, it shows only a small fluctuation, relative standard deviation (RSD) being less than 4.7%, indicating that the photothermal effects have negligible effect on the UV measurement accuracy. With the advantages of simple structure, easy fabrication, low cost, and excellent performance, the proposed sensor is expected to be used for reliable UV detection in practical applications.

A novel sensitized U-shaped fiber-optic sensor based on the localized surface plasmon resonance (LSPR) principle was proposed to detect virus RNA, especially COVID-19 RNA sequences. To accomplish ultrahigh sensitivity for detecting COVID-19 RNA sequences, a novel porous gold nanocube particle was proposed for the first time to sensitize a U-shaped fiber made of multimode fiber (MMF)-no-corefiber (NCF)-MMF. The sensor first coats a gold film on the surface of the fiber to excite surface plasmon resonance (SPR). Then, it coats a porous gold nanocube particle on the surface of the gold nanofilm to excite the LSPR, which improves the sensitivity of the sensor. Gold nanoparticles can form tip structures on the sensor surface, causing a hot spot effect. This increases the sensitivity of the fiber-optic sensor compared to the conventional U-shaped fiber-optic sensor without sensitization treatment and the U-shaped fiber-optic sensor combined with spherical gold nanoparticles for sensitization. The experimental results showed that the sensor’s refractive index (RI) sensitivity reached 3893 nm/RIU. The reverse-transcribed complementary DNA (cDNA) of one piece of COVID-19 RNA was used as the sample to be detected in this article to demonstrate the performance of the sensor. The specific detection of cDNA was achieved by chemical modification of the sensor’s surface and DNA hybridization technology. The sensor’s sensitivity is 0.41 nm/nM, significantly improving over conventional fiber-optic biosensors regarding RNA concentration detection sensitivity. In the experimental process, the sensor demonstrated high sensitivity, rapid response time, high stability, compact size, and portability, all crucial for viral RNA detection and other biomass detection and measurement.

Er3+/Yb3+ co-doped tellurite glass (TeO2-ZnO-WO3-Li $_{{2}}\text{O}$ -BaF2-Nb2O3-Er2O3 + Yb2O3, TZWLBN) was investigated in the range of 253–443 K, and by varying the molar ratio of Yb3+ ions, the ion concentration of the strongest luminescent emission was found. Based on it, by combining mold casting and fiber drawing techniques, a no-core tellurite fiber (NTF) was fabricated, and then connected with two multimode fibers (MMFs) to form a temperature sensor. Under a pumping power of 2.20 mW, a comprehensive evaluation was conducted to investigate the temperature sensing characteristics of this sensor, employing the fluorescence intensity ratio (FIR) technique. The repeatability and stability of the experimental protocol were established through numerous heating-cooling cycles and constant temperature test. The highest possible absolute and relative sensitivities were determined as 0.00264 and 0.0114 $\text{K}^{-{1}}$ . The temperature sensor exhibited a maximum temperature error of 0.88 K when employed for monitoring the temperature of the metal–oxide–semiconductor field effect transistor (MOSFET) in complex circuits, thereby demonstrating its practical applicability in thermal detection scenarios.

Tributyrin is widely used in medical treatment, drug development, and other fields. Lipase can decompose one tributyrin into one glycerol and three butyric acids, causing the effective refractive index (RI) and pH to change. Detecting the RI change or pH change during the experiment is usually used to determine the tributyrin in the sample. However, these methods encounter limitations at low or high concentrations. The RI difference detection method is difficult to implement in low-concentration detection, but the pH detection method is difficult to apply in high-concentration detection. In this article, we present an optical fiber sensor with dual channels based on surface plasmon resonance (SPR) to achieve the measurement of tributyrin. Polyacrylic acid (PAA)/chitosan (CS) pH-sensitive material is coated on half of the SPR sensor as channel 1 to monitor tributyrin-induced pH changes, and the lipase is bonded on the polydopamine (PDA)/maleic acid (MA) coated on the fiber as channel 2 to decompose tributyrin. Experimental results show that channel 1 realizes high pH sensitivity (34.52 nm/pH) and the tributyrin sensitivity reaches 12.8 nm/mM with a concentration between 0.1 and 1 mM. In the concentration range of 1–4 mM, channel 2 exhibits a tributyrin sensitivity of 4.85 nm/mM. In addition, the sensor proposed in this article has excellent stability and selectivity. Thus, the dual-channel optical fiber SPR sensor holds significant potential for drug development and biomedicine.

A >600 MHz harmonic mode-locked femtosecond holmium-doped (Ho-doped) fiber laser is presented by using the nonlinear polarization rotation (NPR) method. When the fiber laser works in fundamental mode-locking (FML) regime at 2063.1 nm, a pulse repetition rate of 20.8 MHz is obtained with a corresponding pulse duration of 983 fs. By increasing the pump power, 29th-order harmonic mode-locking (HML) operation of the Ho-doped fiber laser is realized for the first time, to the best of our knowledge. The maximum pulse repetition rate of 603 MHz at 2063.7 nm is achieved with a harmonic pulse duration of 996 fs, corresponding to a super-mode suppression radio (SMSR) of as high as 33 dB.

The effects of condenser length and evaporator/condenser elevation on the performance of a loop heat pipe (LHP) in a gravity field were investigated respectively, as well as their coupling effect. The refrigerant R40 was selected, and the condenser length was altered by changing the number of fins connected to the water-cooled plates. The experiments were conducted at three evaporator/condenser elevations, zero elevation, favorable elevation, and adverse elevation. The experimental results indicated that the evaporator temperatures of LHP with three different condenser lengths are very close when the LHP operates in variable conductance mode (VCM). However, an excessively long condenser will increase the LHP thermal resistance in VCM. In constant conductance mode (CCM), the longer the condenser, the lower the evaporator temperature. As the heat load increases, the LHP first exhibits gravity-driven mode and then capillarity-gravity-driven mode at a favorable elevation. The positive coupling effect on reducing the evaporator temperature by extending the condenser length and running at a favorable elevation manifests that the influence of condenser length is very small in gravity-driven mode, while in capillarity-gravity-driven mode, the effect of operating at a favorable elevation gets weakened, and the positive effects of the two factors cannot be simply calculated by the linear superposition principle. Additionally, reverse flow and flash evaporation were also observed and analyzed in depth. These results and conclusions can be used to guide the design of the condenser and the installation of LHP for ground applications.

A low-cost biosensor with multifunctionality, wide detection range, and enhanced sensitivity was highly desirable. In this work, we demonstrated the desirable application of Cu2O@Au in nitrite, glucose, and formaldehyde detection. The surfactant-free synthesis of Cu2O@Au nanocrystals with a hexapod morphology and controllable Au loading rates has been achieved. The surfactant-free surface maximized the active sites and the decoration by Au accelerated electron transfer, resulting in an enhanced biosensor performance. The correlation between the atomic rate and biosensor performance for obtained Cu2O@Au nanocrystals has been investigated systematically. It is indicated that an optimal Au loading rate would not only enhance the sensitivity but also rationalize the sensor cost. In the detection of nitrite, the sensitivity of the sensor constructed by Cu2O@Au-20% was $368.77 ~\mu \text{A}$ /mM $\cdot $ cm2, which exhibited 6.8 folds higher than that by pure Cu2O. The superior biosensor sensitivity of Cu2O@Au could also be extended to the glucose and formaldehyde detection, the enhanced factors could reach 1.26 and 1.88, respectively. Meanwhile, the surface decoration by Au elevated enabled Cu2O an effective photocatalyst. This work optimized the performances of Cu2O by a green approach, which opened up new avenues for designing a nontoxic biosensor with multifunctionality and enhanced performance.

Markov chain (MC) is a stochastic model that describes a sequence of events where the probability of each event depends only on the previous state. Such memoryless property makes MC widely used in machine learning and encryption, but the hardware implementation of MC generation remains challenging. This paper presents a hardware solution for generating MC signals using only one industry-ready magnetic tunnel junction (MTJ). High quality standard MC signal has been generated with low error and good randomness. The proposed solution also demonstrates the potential in increasing the generation speed. The presented solution offers a hardware-friendly implementation of MC signal in semiconductor chips.

ABSTRACT Temperature changes of pavement structure have significant influence on the internal stress, strain, and deformation characteristics of the pavement structure. For example, rutting occurs in high temperature range and [...]

The ceramic-steel-pentaerythritol ester system has a broad application prospect under high temperature conditions, which are respectively in the fields of aviation, aerospace and advanced equipment manufacturing. However, a comprehensive understanding of the friction and wear mechanisms of this system across a broad temperature range remains elusive. The tribological properties of the system at 25–475 °C were studied. With the increase of temperature, the evolution of the tribofilm follows the sequence: discontinuous tribofilm → uniform tribofilm → tribofilm removal. At 200–300 °C, an approximately 100 nm thick amorphous PxOycompound tribofilm is formed, and its nanohardness and modulus are reduced by 81.33 % and 54.02 %, respectively, compared with base steel. The tribofilm effectively reduces shear resistance by blocking friction pair contact. When the temperature exceeds 300 °C, it will lead to high-temperature coking, which adversely affects the lubrication performance. It is worth noting that the system can endure short-term service at a maximum temperature of 475 °C. Therefore, this research can help achieve continuous, stable operation of high-temperature resistant systems, as well as short-term use under extreme conditions encountered by complex equipment.

In this article, Er $^{{3}+}$ /Yb $^{{3}+}$ co- doped TeO2-Li $_{{2}}\text{O}$ -ZnF2-WO3-Nb2O5 (TZWLN) glasses were prepared using the melt annealing methods, and the rare Earth (RE) ion concentrations were optimized to achieve the strongest green up-conversion (UC) luminescence. Based on it, a temperature sensor drawing on the fluorescence intensity ratio (FIR) technique was developed via a dual solidification process for real-time temperature monitoring of automotive 3-D LiDAR (A3DL). The sensing performance of the sensor was evaluated in the temperature range of 252 to 453 K. The maximum absolute sensitivity ( ${S}_{a}{)}$ was $3.98\times 10^{-{3}}\,\,\text{K}^{-{1}}$ at 453 K, and the maximum relative sensitivity ( ${S}_{r}{)}$ was 0.0146 $\text{K}^{-{1}}$ at 252 K. Global rapid thermal cycling repetition experiments and local temperature jump stability experiments were conducted, and temperature information was demodulated using the FIR mathematical model. In the repetition experiments, the maximum residual sum of squares (RSSs) was $9.98\times 10^{-{3}}$ , and in the temperature jump experiments, the standard deviation of demodulated temperatures was 0.064 and 0.063. It is worth noting that the maximum measurement error of the sensor in the real-time temperature detection of the onboard LiDAR was only 0.77 K. To the best of our knowledge, this was the first report on using fluorescent temperature sensors for real-time temperature detection of A3DL. The proposed sensor has the advantages of excellent stability and repeatability, resistance to electromagnetic interference and corrosion, as well as the capacity to avoid cross-sensitivity. It offers an effective and reliable measurement scheme for real-time temperature detection in A3DL.

Hepatitis B Virus (HBV) core protein allosteric modulators (CpAMs) are an attractive class of potential anti-HBV therapeutic agents. Here we describe the efforts toward the discovery of a series of 4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine (THPP) compounds as HBV CpAMs that effectively inhibit a broad range of nucleos(t)ide-resistant HBV variants. The lead compound 45demonstrated inhibition of HBV DNA viral load in a HBV AAV mouse model by oral administration.

Silkworm is an important economic insect in China, but very vulnerable to infection by a variety of pathogens in the process of breeding. Among them, the parasitism of Nosema bombycis can cause pebrine disease of silkworm (PDS), seriously endanger the production of silkworm seeds, and lead to huge economic losses. Timely detection of N. bombycis is an effective measure to prevent the outbreak of PDS in the early stage of infection, so a rapid and accurate detection technology suitable for on-site detection of N. bombycis is very important. In order to break through the application limitations of the existing detection technology for N. bombycis, in this study, combining Recombinase Polymerase Amplification (RPA) technology and CRISPR/Cas12a system, by optimizing the key components concentration, we successfully established a rapid visual detection technology for N. bombycis including CRISPR/Cas12a fluorescence detection and CRISPR/Cas12a immunochromatographic detection. Compared with the traditional nucleic acid detection technology, the detection sensitivity of this technology was up to 2 copies/μL, the detection limit of N. bombycis genome was 2 fg/μL, and can detect as low as 100 microsporidia added in 100 healthy silkworm eggs, showing high sensitivity. By detecting silkworm tissues infected with different pathogens, we demonstrated that CRISPR/Cas12a detection technology has good specificity. The accuracy rate of the actual sample is 100%. The technology has the advantage of rapidness, accuracy, visualization, low cost, low equipment requirements and simple operation, and is suitable for the on-site detection of N. bombycis.

In this article, a Mach Zehnder interference temperature sensor is proposed by tightly joining a double-cladding tellurite optical fiber (DTF) between two sections of silica single-mode fiber (SMF) using the fusion splicing method. In the real-time temperature measurement of glycerin solution, this Mach-Zehnder Interferometric (MZI) sensor exhibits a temperature sensitivity as high as 313.8 pm/°C in the range of $10 ^{\circ} \text{C}\sim 60 ^{\circ} \text{C}$ . The stability-induced temperature error and the maximum repeatability standard deviation are $\pm 0.5 ^{\circ} \text{C}$ and $\pm 0.4 ^{\circ} \text{C}$ , respectively. Attractively, the sensor is virtually unresponsive to changes in refractive index of the external environment, making it suitable for temperature measurement of a wide range of high-refractive-index organics. Therefore, the sensor is expected to be further applied in the manufacture, storage and application of chemical reagents.

At present, wearable flexible pressure sensors have broad application prospects in fields such as motion monitoring and information transmission. However, it is still a challenge to design flexible pressure sensors with high sensitivity over a large sensing range and simple fabrication. Here, we use a simple “dipping-drying” method to fabricate a fabric-based flexible pressure sensor by coupling silver nanowires (AgNWs) with Ti3C2-MXene. The interaction between MXene and AgNWs helps realize a dual-layer sensing network, achieving good synergistic effects between pressure sensitivity and sensing range. The effects of the material combination and dip-coating sequence on the sensor’s performance are systematically studied. The results show that the sensor was impregnated sequentially with AgNWs solution, and the MXene solution has the highest sensitivity (0.168 kPa–1) over a wide range (190 kPa). Meanwhile, it has the advantages of low response hysteresis and detection limit, as well as good linearity and durability. We further demonstrate the application of this sensor in human physiological signal monitoring and motion pattern recognition. It can also encrypt and transmit information according to different pressing states. In addition, the proposed pressure sensor array exhibits spatial resolution detection capabilities, laying the foundation for applications in the fields of motion monitoring and human–computer interaction.

This article investigates the effect of gold film thickness and spherical gold nanoparticles (AuNPs, of different sizes and at different coverage rates) on the performance of optical fiber surface plasmon resonance (SPR) sensors based on multimode fiber–single-mode fiber (MMF–SMF) structure. Simulations and experiments showed that sensors with gold film thickness around 50 nm have higher performance when AuNPs are not immobilized. AuNPs in the 28–58 nm diameter range offered superior sensitization and can improve the figure of merit (FOM), but it required precise control of AuNPs fixation time, especially for AuNPs with a diameter over 48 nm. As the coverage of AuNPs increased, the sensitivity of the sensor increased first in the reverse direction and then in the positive direction. The refractive index (RI) sensitivity can reach 4234 nm/RIU with the FOM of 12.5 RIU $^{-{1}}$ in the experiment, which are a 2.75-fold increase and a 1.74-fold increase compared to before the AuNPs were fixed (1541 nm/RIU and 7.18 RIU $^{-{1}}$ ). Our work is of great significance for improving the sensitivity of fiber optic SPR biosensors.

ABSTRACT Based on the principle of the interfacial polymerization method and the mechanism of polypropylene glycol diglycidyl ether OH-230), which can be used to adjust the molecular structure of the [...]

The aim of this study was to characterise the whole genome sequence of multidrug-resistant Streptococcus pluranimaliumstrain SP21–2 of swine origin in China.