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Herein, we report an example of a stereoselective γ-addition reaction of trifluoromethyl ketimines to 1-alkynyl ketones mediated by an isothiourea, BTM, under mild conditions, which afforded tetrasubstituted allenes with central chiralities in high yields (up to 94% yield), good enantioselectivities (up to 91% ee), and excellent diastereoselectivities (all >20 : 1 dr). In addition, the BTM-catalyzed γ-addition reaction was successfully applied to the gram-scale reaction, and an unexpected benzopyrrolothiazine derivative was successfully converted, albeit racemic. [ABSTRACT FROM AUTHOR]

Objective. Herbal medicine discovery is a complex and time-consuming process, while pharmacophore modeling and molecular docking methods enable simple and economic studies. The pharmacophore model provides an abstract description of essential intermolecular interactions between chemical structures, and the molecular docking technology can identify novel compounds of therapeutic interests and predict the ligand-target interaction at the molecular level. This study was based on the two methods to elucidate the mechanism of dehydrovomifoliol, an active ingredient extracted from Artemisia frigida willd, in nonalcoholic fatty liver disease (NAFLD). Methods. Bioinformatics analysis was performed to screen target genes of dehydrovomifoliol in NAFLD treatment, which were thus intersected with NAFLD-related differentially expressed genes (DEGs) and NAFLD-related genes. Venn diagram was used to identify candidate DEGs. A pharmacophore model was then generated, and molecular docking was performed. A protein-protein interaction (PPI) network was constructed to identify core genes, which were evaluated using GO and the KEGG enrichment analyses. Results. Seven target genes of dehydrovomifoliol in NAFLD treatment were screened out, namely E2F1, MERTK, SOX17, MMP9, SULT2A1, VEGFA, and BLVRA. The pharmacophore model and molecular docking of candidate DEGs and dehydrovomifoliol were successfully constructed. E2F1 was identified as a core gene of dehydrovomifoliol in NAFLD treatment. Further enrichment analysis indicated the regulatory role of E2F1 in fat metabolism was associated with the regulation of the AKT/mTOR signaling pathway. Conclusion. Overall, this study illustrates the anti-NAFLD mechanism of dehydrovomifoliol, which could be a useful compound for developing novel drugs in the treatment of NAFLD. [ABSTRACT FROM AUTHOR]

Flexible respiratory monitoring devices have become available for outside-hospital application scenarios attributable to their improved system wearability. However, the complex fabrication process of such flexible devices results in high prices, limiting their applications in real-life scenarios. This study proposes a flexible, low-cost, and easy-processing paper-based humidity sensor for sleep respiratory monitoring. A paper humidity sensing model was established and sensors under different design parameters were processed and tested, achieving high sensitivity of 5.45 kΩ/%RH and good repeatability with a matching rate of over 85.7%. Furthermore, the sensor patch with a dual-channel 3D structure was designed to distinguish between oral and nasal breathing from origin signals proved in the simulated breathing signal monitoring test. The sensor patch was applied in the sleep respiratory monitoring of a healthy volunteer and an obstruct sleep apnea patient, demonstrating its ability to distinguish between different respiratory patterns as well as various breathing modes. [ABSTRACT FROM AUTHOR]

Human motion recognition with high accuracy and fast response speed has long been considered an essential component in human-machine interactive activities such as assistive robotics, medical prosthesis, and wearable electronics. The force myography (FMG) signal has been the focus of much investigation in the search for a reliable and efficient muscular locomotion recognition system. However, the effect of the sensing system on FMG-based locomotion classification accuracy has yet to be understood. This study proposed a novel FMG sensing strategy for human lower limb locomotion classification based on flexible supercapacitive iontronic sensors. Benefiting from the ultrahigh sensitivity (up to 1 nF/mmHg) and low activation pressure (less than 5 mmHg) of the supercapacitive iontronic pressure sensor, FMG signal can be acquired accurately from 5 iontronic sensors strapped to the thigh. In the experiment with 12 subjects, the real-time classification strategy based on sliding window and SVM model gave an average locomotion classification accuracy of 99% for seven categories, including sitting, standing, walking on level ground, ramp ascent, ramp descent, stair ascent, stair descent. Compared with traditional FSR sensors, the result showed that iontronic sensors improved the classification accuracy by up to 10 percentage points in the case of short time window. The implementation of the high sensitivity flexible iontronic sensors in the wearable system brings a valuable tool for detecting small human body pressure signals and has great potential to improve the performance of the human-machine interface in rehabilitation and medical applications. [ABSTRACT FROM AUTHOR]

Objective Interface pressure, the sine qua non for compression therapy, is rarely measured in clinical practice and scientific research. The goal of this study aimed to compare and examine the accuracy between a commercially available piezoresistive sensor and PicoPress® (Microlab, Padua, Italy) using the cylinder cuff model to measure in-vitro interface pressure. Method Ten piezoresistive sensors were calibrated using the National Institute of Standard and Technology certified manometer, and compared to PicoPress® using cylinder cuff model from 20 to 120 mmHg. Two statistical analyses were performed: (a) two-sample t-test to compare the front to back surface of the piezoresistive sensors using mean pressure value and (b) one-sample paired t-test to compare the front and back surface of the piezoresistive sensors to PicoPress® and true pressure using mean pressure value. Result There was no difference in interface pressure measurement between the front and back surface of the piezoresistive sensors (P > 0.05). Using mean pressure value, there was no significant difference between the front surface, back surface of the piezoresistive sensors, and PicoPress® (P > 0.05). Standard deviation was larger for the piezoresistive sensors than PicoPress® at any given pressure and this difference was more pronounced in the higher pressure range. Conclusion Piezoresistive sensor may represent a viable alternative to PicoPress® in interface pressure measurement. [ABSTRACT FROM AUTHOR]

The latest development in wearable technologies has attracted much attention. In particular, collection and analysis of body fluids has been a focus. In this paper, we have reported a wearable microfluidic platform made using conventional fabric materials and laser micromachining to measure the flow rate on a patterned fabric surface, referred to as digital droplet flowmetry (DDF). The proposed wearable DDF is capable of collecting and measuring continuous perspiration with high precision (96% on average) in a real-time fashion over a defined area of skin. We have introduced a theoretical model for the proposed wearable interfacial microfluidic platform, under which various design parameters have been investigated and optimized for various conditions. The novel digitalized measurement principle of DDF provides fast responses, digital readouts, system flexibility, and continuous performance of the flow measurement. Moreover, the proposed DDF platform can be conveniently implemented on regular apparel or a wearable device, and has potential to be applied to dynamic removal, collection and monitoring of biofluids for various physiological and clinical processes. [ABSTRACT FROM AUTHOR]

A microfluidic tactile sensing device has been first reported for three-dimensional contact force measurement utilizing the microfluidic interfacial capacitive sensing (MICS) principle. Consisting of common and differential microfluidic sensing elements and topologically micro-textured surfaces, the microfluidic sensing devices are intended not only to resolve normal mechanical loads but also to measure forces tangent to the surface upon contact. In response to normal or shear loads, the membrane surface deforms the underlying sensing elements uniformly or differentially. The corresponding variation in interfacial capacitance can be detected from each sensing unit, from which the direction and magnitude of the original load can be determined. Benefiting from the highly sensitive and adaptive MICS principle, the microfluidic sensor is capable of detecting normal forces with a device sensitivity of 29.8 nF N−1 in a 7 mm × 7 mm × 0.52 mm package, which is at least a thousand times higher than its solid-state counterparts to our best knowledge. In addition, the microfluidic sensing elements enable facilitated relaxation response/time in the millisecond range (up to 12 ms). To demonstrate the utility and flexibility of the three-dimensional microfluidic sensor, it has been successfully configured into a fingertip-amounted setting for continuous tracing of the fingertip movement and contact force measurement. [ABSTRACT FROM AUTHOR]

There is an increasing demand for sensitive, flexible, and low-cost pressure sensing solutions for health monitoring, wearable sensing, robotic and prosthetic applications. Here, the first flexible and pressure-sensitive microfluidic film is reported, referred to as a microflotronic, with high transparency and seamless integratability with the state-of-the-art microelectronics. The microflotronic film represents the initial effort to utilize a continuous microfluidic layer as the sensing elements for large-area dynamic pressure mapping applications, and meanwhile an ultrahigh sensitivity of 0.45 kPa−1 has been achieved in a compact, flexible, and transparent packaging. The response time of the device is in the millisecond range, which is at least an order of magnitude faster than that of its conventional flexible solid-state counterparts. In addition, the fabrication process of the device is fully compatible with the industrial-scale manufacturing of capacitive touchscreen devices and liquid-crystal displays. The overall device packaging can be as thin as 200 μm with an optical transparency greater than 80%. Several practical applications were successfully demonstrated, including surface topology mapping and dynamic blood pressure monitoring. The microflotronic devices offer an alternative approach to the solid-state pressure sensors, by offering an unprecedented sensitivity and ultrafast response time in a completely transparent, flexible and adaptive platform. [ABSTRACT FROM AUTHOR]

An iontronic microdroplet array (IMA) device, using an ultra-large interfacial capacitance at the highly elastic droplet–electrode contact, has been proposed for flexible tactile sensing applications. The transparent IMA sensors consist of an array of nanoliter droplets sandwiched between two polymeric membranes with patterned transparent electrodes, forming the electrical double layers with remarkable unit-area capacitance. Under external loading, the membrane deformation results in the circumferential expansion at the highly elastic droplet–electrode contact, which offers a completely new capacitive sensing scheme with a dramatic increase in sensitivity. Under the simple device architecture, the IMA has achieved device sensitivity of 0.43 nF kPa−1 and a minimal detectable pressure of 33 Pa, the highest reported values for its dimension. In addition, the hysteresis of the droplet deformation has been reduced by introducing a layer of hydrophobic coating to the conductive electrode surface, ensuring a fast mechanical response (on the order of several milliseconds). To demonstrate the utility of the transparent flexible IMA sensor, it has been successfully mounted onto a fingertip setting to map different surface topologies and embedded into a wristband to resolve dynamic pressure waves throughout cardiovascular cycles. [ABSTRACT FROM AUTHOR]

Abstract: White light interferometer can be used to measure the amplitude extinction ratio (ER) of polarizer and coupling distribution in fiber. A LiNbO3 polarizer coupled with a polarization maintaining fiber and a silica planar waveguide at the two ends was measured using white light interferometer. According to the principles of optical coherence domain polarimeter (OCDP) technique, the test scheme is analyzed and presented to measure the ER of LiNbO3 polarizer with its apparatus proposed correspondingly. By analyzing the interference intensity, both the ER of LiNbO3 polarizer and its coupling crosstalk with optical fiber and waveguide are obtained. The results illustrate that the ER of a 5mm-long LiNbO3 polarizer is 71dB and the crosstalk of the coupling points are around 40dB. The results have good agreement with analysis. [Copyright &y& Elsevier]

In article number 1807343, Yu Chang, Tingrui Pan, and co‐workers report a flexible iontronic sensing paper by incorporating both ionic and conductive patterns into an all‐in‐one flexible sensing platform. The paper can be structured into 2D or 3D tactile sensing‐enabled origamis with remarkable sensitivity, response time, and linearity only by paper‐specific manipulations of printing, cutting, folding, and gluing. [ABSTRACT FROM AUTHOR]

Paper has been utilized as an ideal platform for chemical, biological, and mechanical sensing for its fibrous structures and properties in addition to its low cost. However, current studies on pressure‐sensitive papers have not fully utilized the unique advantages of papers, such as printability, cuttability, and foldability. Moreover, the existing resistive, capacitive, and triboelectric sensing modalities have long‐standing challenges in sensitivity, noise‐proofing, response time, linearity, etc. Here, a novel flexible iontronic sensing mechanism, referred to as iontronic sensing paper (ISP), is introduced to the classic paper substrates by incorporating both ionic and conductive patterns into an all‐in‐one flexible sensing platform. The ISP can then be structured into 2D or 3D tactile‐sensitive origamis only by the paper‐specific manipulations of printing, cutting, folding, and gluing. Notably, the ISP device possesses a device sensitivity of 10 nF kPa−1 cm−2, which is thousands of times higher than that of the commercial counterpart, a resolution of 6.25 Pa, a single‐millisecond response time, and a high linearity (R2 > 0.996). Benefiting from the unique properties of the fibrous paper structures and its remarkable performances, the ISP devices hold enormous potential for the emerging human–machine interfaces, including smart packaging, health wearables, and pressure‐sensitive paper matrix. A flexible iontronic sensing paper with both ionic and conductive patterns as an all‐in‐one flexible sensing platform, with direct printability, custom cuttability, and 3D foldability is structured into a pressure‐sensing device by paper‐specific manipulations in the forms of a 2D device or a 3D tactile‐sensing‐enabled origami with remarkable sensitivity, resolution, response linearity, and response time. [ABSTRACT FROM AUTHOR]

T. Pan and co‐workers present a flexible, transparent, and pressure‐sensitive microfluidic film, referred to as microflotronics, for large‐area dynamic pressure mapping. On page 6195, utilizing a continuous responsive microfluidic layer as the sensing element, the microflotronic sensors offer an alternative approach to the solid‐state counterparts, by offering an unprecedented sensitivity and ultrafast response time in a completely transparent, flexible, and adaptive package. [ABSTRACT FROM AUTHOR]

Rationale and Objectives: New vertebral compression fractures (NVCF) are very common in patients following percutaneous vertebroplasty (PVP) or kyphoplasty (PKP). The study aims to evaluate the comparative predictive performance of vertebral bone quality (VBQ) score and Hounsfield units (HU) value in forecasting NVCF after surgery., Materials and Methods: This study retrospectively analyzed patients who underwent PVP/PKP at our institution between 2020 and 2021. The VBQ score and HU value were obtained from preoperative magnetic resonance imaging (MRI) and computed tomography (CT) scans, respectively. Subsequently, the forecasting capabilities of these two parameters were assessed by contrasting their receiver operating characteristic (ROC) curve., Results: A total of 303 eligible patients (56 with NVCF and 247 without) were identified in the study. Six relevant literature factors were identified and included in the multivariate analysis revealed that lower HU value (OR = 0.967, 95% CI = 0.953-0.981, P < 0.001) and higher VBQ score (OR = 3.964, 95% CI = 2.369-6.631, P < 0.001) emerged as independent predictors of NCVF occurrence. Compared to the ROC curve of the HU value, demonstrating a diagnostic accuracy of 83.2% (95% CI = 77.5%-88.9%, P < 0.001), the VBQ score was 85.8%. And, a statistically significant negative correlation was observed between the VBQ score and the T-score (r = -0.529, P < 0.001)., Conclusion: In patients undergoing PVP/PKP, VBQ score, and HU value are independently associated with the occurrence of NVCF. Assessing the HU value and the VBQ score could play an effective role in planning PVP/PKP operations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Objective: Peripheral vascular disease is a worldwide leading health concern. Real-time peripheral hemoperfusion monitoring during treatment is essential to plan treatment strategies to improve circulatory enhancement effects., Methods: The present work establishes a Janus flexible perfusion (JFP) sensor system for dynamic peripheral hemoperfusion monitoring. We develop a Janus structure with different Young's modulus to improve the mechanical properties for motion artifacts suppression. Besides, we propose a peripheral perfusion index (PPI) based on an optical perfusion model that is experimentally verified using an in-vitro model. The effectiveness of the system is assessed in three experimental scenarios, including motion artifact-robust test, induced vascular occlusion, and peripheral hemoperfusion monitoring with the intermittent pneumatic compression treatment., Results: The noise level of the traditional rigid sensor is five times that of the JFP sensor within the effective signal frequency domain when there is movement. The PPI can effectively discriminate between different peripheral hemoperfusion states and has a correlation coefficient of 0.92 with the Laser Doppler flowmetry (LDF) mean values. The kappa statistic between the JFP sensor and LDF is 0.78, indicating substantial agreement to estimate the peripheral hemoperfusion improvements., Conclusion: The sensor system we proposed can monitor peripheral hemoperfusion variation in real-time and is insensitive to motion artifacts., Significance: The proposed sensing system provides a functional module for real-time estimation of peripheral hemoperfusion during clinical interventions.

Degradation and delamination resulting from environmental humidity have been technically challenging for poly (3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) thin-film processing. To overcome this problem, we introduced a one-step photolithographic method to both pattern and link a PEDOT:PSS film onto a poly (ethylene glycol) (PEG) layer as a hybrid thin film structure on a flexible substrate. This film exhibited excellent long-term moisture stability (more than 10 days) and lithographic resolution (as low as 2 μm). Mechanical characterizations were performed, including both stretching and bending tests, which illustrated the strong adhesion present between the PEDOT:PSS and PEG layers as well as between the hybrid thin film and substrate. Moreover, the hybrid moisture-absorbable film showed a quick response of its permittivity to environmental humidity variations, in which the patterned PEDOT:PSS layer served as an electrode and the PEG layer as a moisture-sensing element. Perspiration tracking over various parts of the body surface as well as breath rate measurement under the nose were successfully carried out as demonstrations, which illustrated the potential utility of this stable hybrid thin film for emerging flexible and wearable electronic applications., Competing Interests: The authors declare no conflict of interest.