Search Results (1,562)

Green Analytical Chemistry (GAC) provides a framework for reducing hazardous reagents, energy consumption, and waste. The topic has gained momentum across many chemical industries over the past 25 years; however, progress in implementing sustainable methods and conducting greenness assessments within forensic laboratories has been comparatively slow. The purpose of this review is to highlight green approaches to analytical separation methods, including greenness assessment metrics, that have been reported in the literature for forensic chemistry and toxicology applications and to raise awareness of GAC in the forensic field. Recent scientific literature highlights promising advances in greener sample preparation and chromatographic approaches, particularly in forensic toxicology and seized-drug analysis. Emerging trends include the use of green solvents, bio-based and deep eutectic solvent systems, and the rapid expansion of microextraction techniques such as SPME, LPME, MEPS, FPSE, and DLLME, which reduce solvent volumes, minimize waste, and support higher-throughput workflows. Parallel developments in portable and miniaturized chromatographic instrumentation such as miniaturized LC–MS systems with increased detection specificity and Lab-on-a-Chip applications show promise for in situ measurements in the field. Ambient ionization mass spectrometry—in particular, DESI and DART—has had a major impact on forensic chemistry by providing tools for the rapid and direct analysis of chemical compounds in complex matrices with little or no sample preparation. Greenness assessment tools—including AGREE, AGREEprep, Eco-Scale, GAPI, and BAGI—are increasingly applied to evaluate analytical methods in forensic chemistry and toxicology, including those used for novel psychoactive substances. Although many green methodologies are well documented, their routine implementation remains limited. The continued integration of green solvents, microextractions, portable instrumentation, and standardized greenness metrics will be essential for advancing sustainable forensic separations. Full article

Background: We previously established that striatal, but not cortical, dopaminergic activation stimulates movement, indicating that the crucial and original site of dopaminergic stimulation of motor function is the striatum, not the motor cortex. In the present study, we have further investigated the potential effects of the cortical and striatal dopaminergic activity on cortical pyramidal neuron physiology. Methods and Results: First, under a constant fluorescence imaging condition, we established that DA innervation and D1R and D2R expression were very low in the cerebral cortex but very high in the striatum. Second, we performed cellular neurophysiological experiments on layer 2/3 pyramidal neurons in the primary motor cortex (M1) in tyrosine hydroxylase gene knockout (TH-KO) DA-depleted mice that have hyperfunctional DA receptors. Using brain slice–whole-cell patch-clamping techniques, we found that M1 layer 2/3 pyramidal neurons had lower input resistance, stronger inward rectification, more negative RMP, and fired fewer spikes in DA-depleted TH-KO mice than in DA-intact WT mice; M1 layer 2/3 pyramidal neurons also had a diminished synaptic release function with reduced frequencies for spontaneous and miniature excitatory synaptic currents in TH-KO mice compared to WT mice. Third, we also found that when TH-KO mice were treated with L-dopa before brain slice preparation, these neurophysiological deficits of M1 layer 2/3 pyramidal neurons were reversed, but 30 min incubation of cortical brain slices with 10–20 μM DA produced no detectable effect in M1 layer 2/3 pyramidal neurons in TH-KO mice and WT mice. Fourth, Golgi staining showed that cortical pyramidal neuron morphology was indistinguishable between WT mice and TH-KO mice. Conclusions: Our results indicate that DA loss in the striatum, not in the cortex, indirectly reduces cortical pyramidal neuron membrane excitability and weakens synaptic function. Our data also indicate that (1) the normal direct effects of the cortical DA system on cortical pyramidal neurons are weak, (2) the striatal DA system is the dominant DA system in the brain, and (3) striatal DA activity can indirectly increase cortical neuron activity (spike firing and synaptic activity) and thus critically contribute to brain function. Additionally, our data suggest that in DA depletion rodent PD models, DA loss-induced effects on cortical pyramidal neurons and other neurons are functional rather than structural, such that DA replenishment restores motor function almost instantaneously. These findings provide important insights into how the brain’s dopaminergic system controls our motor and cognitive functions and indicate that the striatum is the main therapeutic target of dopaminergic drugs. Full article

Background: Plasmid-mediated horizontal transfer of antimicrobial resistance genes (ARGs) is a major driver of resistance dissemination across clinical and environmental settings. Urban rivers flowing through densely populated megacities represent critical interfaces where human-associated and environmental microbiomes intersect; however, the genetic structures and functional characteristics of resistance plasmids circulating in such environments remain insufficiently resolved. Methods: In this study, we conducted detailed genomic and phenotypic analyses of 11 ARG-bearing plasmids previously captured from the Tama River, an urban river flowing through the Tokyo megalopolis. These plasmids belonged to IncN, IncU, IncQ2γ, IncC, and IncPγ groups. Whole-plasmid sequencing, comparative genomic analyses, conjugation assays, and antimicrobial susceptibility testing were employed to characterize plasmid backbones, accessory resistance regions, mobile genetic elements, and conjugative transferability. Results: A total of 11 plasmids belonging to five major incompatibility groups (IncN, IncC, IncU+IncQ2γ, and IncP) were analyzed. These plasmids collectively encoded ARGs conferring resistance to five major antimicrobial classes, including aminoglycosides, β-lactams, tetracyclines, chloramphenicol, and mercury, and frequently harbored class 1 integrons, ISCR1 elements, and Tn3-derived inverted-repeat miniature elements (TIME). Notably, two plasmids (IncN and IncC) exhibited high structural similarity to clinically reported plasmids from geographically distant regions, whereas multiple IncP plasmids and one multi-replicon IncU+IncQ2γ plasmid displayed accessory-region architectures characteristic of environmental plasmids and broad host-range transferability. Antibiotic susceptibility testing demonstrated that these plasmids substantially increased resistance levels in hosts. Conclusions: This study reveals that urban river environments can harbor both clinically related and environmentally unique multidrug resistance plasmids, shaped by diverse mobile genetic elements. By providing nucleotide-level structural and functional evidence, this study highlights urban rivers as potential ecological hubs linking clinical and environmental resistance plasmid pools and supports the importance of continued monitoring of resistance plasmids in megacity-associated river systems. Full article

This paper proposes a design method for broadband power amplifiers based on bandpass filter matching networks. The approach incorporates transistor complex impedance transformation into the filter matching network design using a low-pass filter design model. By integrating CRLH and D-CRLH structural elements, it forms LC matching structures with a bandpass filter response. This structure achieves wide-band impedance transformation while also providing excellent frequency-selective capabilities. To validate this approach, a 0.7–1.3 GHz bandpass filtering power amplifier was designed and fabricated. It achieves in-band saturated output power of 38.4–41 dBm, drain efficiency of 41–58%, and power gain exceeding 12 dB. The gain flatness is limited to within ±2 dB. Experimental measurements validate the proposed design methodology. This approach imparts exceptional frequency selectivity and superior filtering performance to the system while enabling effective circuit miniaturization. Moreover, it exhibits considerable engineering significance and promising application potential in key fields such as satellite communications, radar monitoring, and digital broadcasting. Full article

Unlike conventional positioning systems that rely on multiple sensors, the positioning system proposed in this study uses a single anisotropic magnetoresistive (AMR) sensor to measure the magnetic field of a target permanent magnet. This approach significantly reduces the system hardware cost and complexity, facilitating the miniaturization of positioning systems. Leveraging a BP neural network model, which is shown to be fast and accurate, the positioning system obtains the real-time magnetic field of the target magnet using a single sensor, subsequently converting three-axis magnetic field data into coordinate information to achieve real-time tracking and localization. The results show that the root mean square errors (RMSEs) for the X and Z axes in the simulation are 0.27 mm and 0.26 mm, respectively, while the RMSEs for the X, Y, and Z axes in the actual test are 0.83 mm, 1.15 mm, and 0.85 mm, respectively. It is also observed that the positioning error correlates with variations in the magnetic field with respect to position, which originate from the strong distance-dependent nonlinearity of the magnetic field. This method not only reduces hardware costs but also maintains accuracy. It is particularly well-suited to applications requiring high-precision positioning and tracking, achieving millimeter-level accuracy within a volume of 50 × 40 × 40 mm³. It has potential applications in aerospace intelligent connectors, medical devices and automation systems, where space and signal lines are limited. Full article

The development of the Lunar–Earth space urgently requires a miniaturized space laser communication system with a high speed and high sensitivity. However, traditional photon-counting communication and coherent communication technologies face challenges in meeting these two core requirements, forming a critical bottleneck that limits the performance enhancement of long-distance lunar communication links. To address this issue, this paper comprehensively analyzes the power attenuation, wavelength drift, and phase jitter over the Lunar–Earth communication channel and proposes a system improvement method that integrates a phase-sensitive amplifier (PSA) with coherent communication technologies. Additionally, a comprehensive system simulation model is established to evaluate the proposed approach. The simulation results demonstrate that the system can effectively adapt to the Lunar–Earth communication scenario. Utilizing QPSK-modulated signals, the system achieves a communication rate of up to 10 Gbps, with receiving sensitivities of 0.7 photons per bit. This approach effectively meets the demand for high data rates and high sensitivity, thus providing a technical pathway for the engineering implementation of ultra-long-distance space laser communications. Full article

In this research, an innovative scheme to generate heterogeneous acoustofluidic distributions in various pseudo-Sierpiński-carpet-shaped chambers with different filling fractions and cross-sectional configurations has been proposed and calculated for topographical manipulation of large-scale micro-particles. All of the structural components positioned in the pseudo-fractal chambers are symmetrically distributed in space, and all ultrasonic radiation surfaces hold the unified settings of input frequency point, oscillation amplitude, and initial phase distribution along their respective normal directions. A large number of fascinating acoustofluidic patterns can be generated in the originally-static pseudo-Sierpiński-carpet-shaped chambers at different recursion levels without complicated vibration parameter modulation. The simulation results of acoustofluidic distributions and particle motion trajectories under different radiation surface arrangements further demonstrate the manipulation performance of these specially designed devices, and indicate that controllable spatial partitioning and intensity modulation of the acoustofluidic field can be achieved by adjusting the hierarchical order, cross-sectional configuration and combination mode of the radiation surfaces. Unlike the existing device construction method of miniaturized microfluidic systems, the artificial introduction of fractal elements like Sierpiński carpet/triangle, Koch snowflake, Mandelbrot set, Pythagoras tree, etc., can provide extraordinary perspectives and expand the application range of the acoustofluidic effect, which also makes ultrasonic micro/nano-scale manipulation technology more abundant and diversified. This exploratory research indicates the potential possibility of applying fractal structures as alternative component parts to purposefully customize acoustofluidic distributions for the further research of patterned manipulation of bio-organisms and navigation of micro-robot swarms in brand new ways that cannot be achieved through traditional methods. Full article

Dynamic monitoring of hemostatic equilibrium is indispensable for clinical safety in high-risk scenarios, while current clinical methods are limited by sample volume, detection speed, and physiological relevance. These shortcomings underscore the demand for novel sensing platforms. Optical biosensors, leveraging label-free detection, rapid response, and multi-level characterization, could serve as a transformative solution for decentralized and point-of-care monitoring. This review systematically summarizes advances in optical coagulation testing, encompassing light transmission aggregometry, laser speckle rheology, optical coherence tomography/elastography, optic–acoustic coupled methods, and fluorescence biosensing. These technologies complementarily capture structural and mechanical and some molecular and cellular dynamics of coagulation, bridging gaps in traditional assays. Despite promising preclinical and clinical correlations, translation barriers persist in lack of standardization of metrics, interference mitigation, and multi-center validation in diverse patient cohorts. Future development of optical biosensing platforms for coagulation testing should focus on modular integration, AI-aided interference correction, and microfluidic miniaturization to realize actionable, real-time coagulation assessment. Optical biosensors hold unparalleled potential to transform hemostatic monitoring from static endpoint testing to dynamic, interpretable evaluation, guiding personalized clinical decisions. Full article

The rapid and accurate detection of pathogenic bacteria and viruses is essential for controlling infectious disease outbreaks and ensuring food safety. Conventional detection methods such as microbial culture, immunoassays, and polymerase chain reaction (PCR), although effective, often suffer from drawbacks including time-consuming procedures, complex operations, and limited multiplexing capabilities. In recent years, electrochemical aptasensors have emerged as a promising alternative for rapid detection of pathogenic bacteria, viruses, and by-products (toxins) due to their high sensitivity, excellent specificity, low cost, and potential for miniaturization. Aptamers can be applied as biorecognition elements of the biosensor, remarkably offering advantages such as high binding affinity, thermal stability, and ease of chemical synthesis. Meanwhile, nanomaterials which provide large surface area, superior conductivity, and modifiable surfaces are widely employed in signal amplification and sensor platform construction. This review discusses the cutting-edge innovations in electrochemical aptasensors in recent years that utilize various types of nanomaterials to accurately identify and quantify diverse types of pathogens and toxins. This review focuses on nanomaterials such as metal nanostructures, carbon nanomaterials, metal, metal oxides, and carbon nanocomposites that can synergistically enhance detection sensitivity, specificity, and operational stability. This review also highlights the promising practical application of the proposed electrochemical aptasensors in clinical diagnostics, environmental monitoring, and food safety. Full article

Indoor environmental quality significantly affects human perceptions of comfort and well-being due to the fact that most daily activities are spent indoors. However, surface colors are generally considered to be aesthetic choices rather than environmental factors. The purpose of this research is to assess the effect of surface colors on visual comfort, thermal intent, and plant-supportive lighting conditions. This study uses a controlled experimental method and four easily interpretable parameters: surface reflectance (albedo), illuminance, correlated color temperature, and photosynthetic photon flux density. The experiment uses a miniature enclosed chamber to standardize the geometry and lighting conditions to test a set of carefully chosen printed and painted color surfaces. The lighting parameters were directly measured using consumer-level spectral and illuminance meters. The surface reflectance parameter is estimated to be red, green, and blue color codes. The novelty of this research is that it provides a preliminary screening method that can convert color choice into quantifiable implications on indoor environments, with clear assumptions and limitations. The results can be used to inform design decisions that link color choice to specific task-oriented lighting requirements, climate-oriented thermal intent (cooler vs. warmer), and plant-rich interior environments. Full article

To meet the miniaturization and lightweight requirements of inter-satellite laser communication, this study investigates the servo control system of a silicon-based optical phased array (OPA). Based on the far-field radiation model for beam steering of the silicon-based OPA, combined with thermo-optic phase modulation technology and time domain response, the transfer function of the silicon-based OPA is established. To address noise and disturbances encountered during actual tracking, a silicon-based OPA beam tracking method for satellite platform vibration is proposed. The control algorithm employs a Kalman filter-based Model Predictive Control (KF-MPC) strategy. The advantages of the designed control algorithm were verified through simulations and experiments. Step response simulation results show that compared with the traditional PID control algorithm, the proposed algorithm reduces overshoot by 15.1% and shortens the response time by 76.4%. Sinusoidal tracking simulation results indicate a 27.15% improvement in tracking accuracy over the traditional PID algorithm. Experimental results demonstrate that the tracking accuracy of the servo control system with the proposed algorithm is 155.45 μrad, while that using the PID algorithm is 210.97 μrad, representing a 26.31% improvement in tracking accuracy. This research provides a valuable reference for the application of silicon-based OPA in inter-satellite laser communication. Full article

The development of autonomous mobile robots or automated guided vehicles is consistently challenged by energy-storage constraints, and while batteries are the standard solution for mobile robots, dynamic wireless power transfer is an alternative way to supply power without reliance on chemical energy storage. For efficient dynamic wireless power transfer, transmitting coils should be energized as required, necessitating real-time position tracking of the receiving coil. Current prevalent techniques require complex modifications to existing systems and additional position sensors, which increase total costs. This article proposes a novel receiving coil position detection method for wireless power transfer systems without using external receiving coil position detection sensors and describes the application of the sensorless coil position detection method and its advantages compared to other methods. The proposed method was implemented on an existing low-power, miniaturized test bench. The described method was successfully validated and correctly switched transmitting coils, ensuring continuous movement of an electric vehicle, therefore proving its viability as a potential new approach for sensorless receiving-coil detection. Experimental results demonstrate that the prototype achieved a maximum power transfer efficiency of 53.8% while maintaining continuous transmitting coil switching operation at vehicle speeds up to 77 cm/s. Full article

Integrating environmental sustainability into chemical sensor research is no longer optional and must be addressed at the laboratory scale, where material selection, fabrication strategies, and end-of-life management are defined. Although chemical sensors benefit from miniaturization and disposable architectures, their environmental footprint extends beyond the device geometry to include the electrode substrates, functional coatings and auxiliary materials. In this context, sensors based on molecularly imprinted polymers (MIPs), which are entirely synthetic and artificially engineered materials, pose specific sustainability challenges related to material choice, processing, regeneration and disposal. Addressing these aspects in a systematic and quantitative manner is therefore essential to aligning high analytical performance with sustainable sensor design. This review surveys and critically discusses the strategies currently adopted to improve the environmental sustainability of MIP-based sensors, covering key stages of the MIP sensor lifecycle, including monomer and crosslinker selection, fabrication routes, operational aspects, and end-of-life management. Representative approaches such as the use of bioderived polymerization components, low-impact solvents, cleaner analyte removal methods, and low-energy polymerization techniques are analyzed, highlighting their advantages, limitations, and cost-related trade-offs. To move beyond the qualitative assessment of greenness, sustainability is addressed through Lifecycle Assessment (LCA) and AGREE-based metrics, highlighting the importance of functional units, use phase inventories, and regeneration strategies in reducing overall environmental impacts. The review concludes by proposing actionable guidelines to support the transition of MIP-based sensors from sustainable laboratory fabrication to real-world environmental monitoring applications. Full article

Traditional involute gear pumps find it difficult to meet the requirements of miniaturization and high performance because of the undercutting, trapped oil, and flow pulsation. To eliminate the phenomenon of trapped oil and reduce flow pulsation in the miniature gear pump, a novel miniature double-circular-arc line gear (MDLG) and its manufacturing method are proposed. Firstly, based on the spatial curve meshing theory, the tooth flank equation of the MDLG is established, and the design method of the MDLG hob is presented. Then, the instantaneous flow rate of the MDLG pump is analyzed by using the swept-area method. Subsequently, a hobbing machining model is built on the VERICUT virtual simulation platform, and machining experiments are conducted on a hobbing machine. Furthermore, the manufactured MDLGs are inspected at a gear measuring center. Finally, an MDLG pump prototype is developed and machined. The measurement results show that the total cumulative pitch deviations of the machined MDLGs are controlled within 32.1 μm, achieving the ISO 8 accuracy grade. The theoretical calculations and experimental results in this article verify the feasibility of the design and processing of MDLG pumps, providing a reference for the development of high-performance miniature gear pumps. Full article

This paper analyzes the potential application of Physics-Informed Neural Networks (PINNs) in solving equations that describe thermal–electrical processes in thermoelectric systems. Combining machine learning with the laws of physics, the PINN method can serve as an alternative to traditional numerical methods, particularly in the context of the miniaturization of cooling systems, heat pumps, and systems that convert thermal energy (heat flow) into electrical energy (e.g., heat recovery), as well as the implementation of models in embedded systems. The article presents a model of thermoelectric equations, explains how PINNs work, provides numerical results, and assesses the advantages and disadvantages of the proposed approach. Full article