Achieving consistency of flexible surface acoustic wave sensors with artificial intelligence.

Flexible surface acoustic wave technology has garnered significant attention for wearable electronics and sensing applications. However, the mechanical strains induced by random deformation of these flexible SAWs during sensing often significantly alter the specific sensing signals, causing critical issues such as inconsistency of the sensing results on a curved/flexible surface. To address this challenge, we first developed high-performance AlScN piezoelectric film-based flexible SAW sensors, investigated their response characteristics both theoretically and experimentally under various bending strains and UV illumination conditions, and achieved a high UV sensitivity of 1.71 KHz/(mW/cm²). To ensure reliable and consistent UV detection and eliminate the interference of bending strain on SAW sensors, we proposed using key features within the response signals of a single flexible SAW device to establish a regression model based on machine learning algorithms for precise UV detection under dynamic strain disturbances, successfully decoupling the interference of bending strain from target UV detection. The results indicate that under strain interferences from 0 to 1160 µÎµ the model based on the extreme gradient boosting algorithm exhibits optimal UV prediction performance. As a demonstration for practical applications, flexible SAW sensors were adhered to four different locations on spacecraft model surfaces, including flat and three curved surfaces with radii of curvature of 14.5, 11.5, and 5.8 cm. These flexible SAW sensors demonstrated high reliability and consistency in terms of UV sensing performance under random bending conditions, with results consistent with those on a flat surface.

Risk factors and a nomogram for prediction of post-endoscopic submucosal dissection electrocoagulation syndrome for superficial colorectal lesions.

BACKGROUND: Post-endoscopic submucosal dissection electrocoagulation syndrome (PEECS) is an uncommon complication after colorectal endoscopic submucosal dissection (ESD). This study aimed to explore the risk factors of PEECS for superficial colorectal lesions based on the latest and consistent diagnostic criteria and to establish a predictive nomogram model. METHODS: This retrospective analysis included patients with superficial colorectal lesions who underwent endoscopic submucosal dissection (ESD) between June 2008 and December 2021 in our center. The independent risk factors of PEECS for superficial colorectal lesions were identified using least absolute shrinkage and selection operator (LASSO) logistic regression analysis, as well as univariate analysis and multivariate logistic regression, and derived predictive nomogram model was constructed. RESULTS: Among the 555 patients with superficial colorectal lesions enrolled, PEECS occurred in 45 (8.1%) patients. Multivariate logistic regression revealed that female sex (OR 3.94, P < 0.001), age > 50 years (OR 4.28, P = 0.02), injury to muscle layer (OR 10.38, P < 0.001), non-lifting sign (OR 2.20, P = 0.04) and inadequate bowel preparation (OR 5.61, P < 0.001) were independent risk factors of PEECS for superficial colorectal lesions. A predictive nomogram model was constructed based on the above five predictors. For this model, the area under the receiver operating characteristic (ROC) curve was 0.855, the calibration curve exhibited good consistency between the prediction and the actual observation, and the C-index was confirmed as 0.843 by bootstrap method. CONCLUSION: Female sex, age > 50 years, injury to muscle layer, non-lifting sign and inadequate bowel preparation were independent risk factors of PEECS for superficial colorectal lesions. The proposed nomogram could accurately predict the risk of PEECS for superficial colorectal lesions.

The efficacy of sclerotherapy as the initial treatment in patients with bleeding from Dieulafoy's lesion of the upper gastrointestinal tract.

BACKGROUND: Dieulafoy's lesion (DL) is a rare and important cause of acute nonvariceal upper gastrointestinal bleeding (ANVUGIB), however, there is a lack of clear guidelines focus on the endoscopic hemostasis treatment for DL. Sclerotherapy, as the ANVUGIB guideline recommended endoscopic hemostasis method, is widely used in clinical practice. The aim of this study is to investigate the efficacy of sclerotherapy as the initial treatment for Dieulafoy's lesion of the upper gastrointestinal tract (UDL). METHODS: Patients with UDL who underwent the ANVUGIB standard endoscopic hemostasis between April 2007 and January 2023 were enrolled. The endoscopic therapy method was left to the discretion of the endoscopist. RESULTS: In total, 219 patients were finally obtained, with 74 (33.8%) receiving sclerotherapy and 145 (66.2%) receiving other standard endoscopic therapy. The rebleeding within 30 days was significantly lower in the sclerotherapy group compared to the other standard group (5.8% vs. 16.8%, p = 0.047). There were no significant differences between the two groups in terms of successful hemostasis rate (93.2% vs. 94.5%, p = 0.713), median number of red blood cell transfusions (3.5 vs. 4.0 units, p = 0.257), median hospital stay (8.0 vs. 8.0 days, p = 0.103), transferred to ICU rate (8.1% vs. 6.2%, p = 0.598), the need for embolization or surgery rate (12.2% vs. 9.7%, p = 0.567) and 30-day mortality (0 vs. 2.1%, p = 0.553). In addition, we found no difference in efficacy between sclerotherapy alone and combination (3.1% vs. 8.1%, p = 0.714). Further analysis revealed that thermocoagulation for hemostasis was associated with a higher rate of rebleeding (28.6% vs. 3.1%, p = 0.042) and longer hospital stay (11.5 vs. 7.5 days, p = 0.005) compared to sclerotherapy alone. CONCLUSION: Sclerotherapy represents an effective endoscopic therapy for both alone and combined use in patients with upper gastrointestinal Dieulafoy's lesion. Therefore, sclerotherapy could be considered as initial treatment in patients with bleeding of UDL.

Investigating amplitude of low-frequency fluctuation and possible links with cognitive impairment in childhood and adolescence onset schizophrenia: a correlation study.

Background: Cognitive impairment (CI) is a distinctive characteristic of schizophrenia, with evidence suggesting that childhood and adolescence onset schizophrenia (CAOS), representing severe but rare forms of schizophrenia, share continuity with adult-onset conditions. While relationships between altered brain function and CI have been identified in adults with schizophrenia, the extent of brain function abnormalities in CAOS remains largely unknown. In this study, we employed resting-state functional magnetic resonance imaging (rs-fMRI) to investigate functional alterations in brain areas among patients with CAOS. To assess CI across multiple cognitive domains, we utilized the Stroop Color and Word Tests (SCWT) and MATRICS Consensus Cognitive Battery (MCCB) tests. Our objective was to explore the associations between functional CI and the amplitude of low-frequency fluctuation (ALFF) levels in these patients. Methods: We enrolled 50 patients diagnosed with CAOS and 33 healthy controls (HCs) matched for sex and age. Cognitive functions were assessed using the MCCB and SCWT methods. Rs-fMRI data were acquired using gradient-echo echo-planar imaging sequences. Voxel-based ALFF group maps were compared through two-sample t-tests in SPM8. Subsequently, correlation analyses were conducted to identify associations between ALFF levels and cognitive scores. Results: In comparison to HCs, patients exhibited significantly increased ALFF levels in the right fusiform gyrus, frontal lobe, and caudate, as well as the left frontal lobe and caudate. Conversely, reduced ALFF levels were observed in the temporal and left medial frontal lobes. Significant differences were identified between HCs and patients in terms of total cognitive scores, ALFF levels, and domain scores. All test scores were decreased, except for TMA. Correlation analyses between ALFF levels and cognitive functions in patients with CAOS differed from those in HCs. Pearson correlation analyses revealed positive associations between Brief Visuospatial Memory Test - Revised (BVMT-R) scores and ALFF levels in the left medial frontal gyrus. Digital Span Test (DST) scores were negatively correlated with ALFF levels in the right caudate, and Maze Test values were negatively correlated with levels in the left caudate. However, Pearson correlation analyses in HCs indicated that color and Hopkins Verbal Learning Test (HVLT-R) scores positively correlated with ALFF levels in the left frontal lobe, while color-word and symbol coding scores negatively correlated with levels in the right caudate. Conclusions: Altered ALFF levels in the brain may be linked to cognitive impairment (CI) in patients with CAOS. We highlighted the pathophysiology of schizophrenia and provide imaging evidence that could potentially aid in the diagnosis of CAOS.

Highly Stretchable Room-Temperature Self-Healing Conductors Based on Wrinkled Graphene Films for Flexible Electronics.

Flexible conductors are emerging soft materials for diverse electrical applications. However, it still remains a great challenge to fabricate high-performance soft conductors that are highly conductive, largely stretchable, and rapid room-temperature self-healable. Here, we design and fabricate flexible conductive bilayer composite films composed of healable elastomeric substrates and wrinkled graphenes. The elastomeric substrates, obtained by a facile bulk copolymerization of N-isopropylacrylamide and 2-methoxyethyl acrylate, show fast room-temperature self-healing efficiency of up to 96%, imparted by the reversible hydrogen bonds. Importantly, the substrates also display strong interfacial adhesion crucial to the formation of stable bilayer composite films based on a prestrain route. The synergy between self-healing of the substrates and wrinkled structures of graphene is endowed to the composite films for mechanical and electrical healing. By adjusting the prestrain ratio of the substrates, the composite films could display the tunable stretchability, conductivity, and self-healing. The optimal bilayer composite film exhibits a high conductivity of 126 S cm-1, a large stretchability of 300%, and rapid room-temperature self-healing. Moreover, it is demonstrated that the composite films are strain-sensitive and can be used as strain sensors to monitor stretching deformation and human motion. These prominent demonstrations suggest a great potential of the bilayer composite films in next-generation wearable electronics.

A self-healable and tough nanocomposite hydrogel crosslinked by novel ultrasmall aluminum hydroxide nanoparticles.

Self-healing hydrogels like tissues or organs which are repaired automatically in response to damage show great promise. However, it remains a challenge to develop novel functional nanoparticles as crosslinkers to prepare tough and self-healing nanocomposite hydrogels. Here, we report the preparation of water-soluble ultrasmall aluminum hydroxide nanoparticles with a diameter of 2-3 nm through a simple sol-gel method. Furthermore, a tough nanocomposite hydrogel is prepared by the in situ copolymerization of acylamide and 2-acrylamido-2-methyl propane sulfonic acid in the presence of aluminum hydroxide nanoparticles. The resulting hydrogels exhibit high compressive strength of 18.9 MPa and an elongation at break of ∼2100%. Importantly, the Al-NC gel displayed a high self-healing efficiency of 86% without any external stimulus at room temperature. Moreover, we found an interesting multi-hierarchical porous morphology of the Al-NC gel depending on the contents of the aluminum hydroxide nanoparticles. The tough nanocomposite hydrogel might provide a novel promising avenue for designing advanced self-healable soft materials for various biomedical applications.

Bio-inspired layered chitosan/graphene oxide nanocomposite hydrogels with high strength and pH-driven shape memory effect.

The layered nanocomposite hydrogel films containing chitosan (CS) and graphene oxide (GO) have been prepared by water evaporation induced self-assembly and subsequent physical cross-linking in alkaline solution. The layered CS/GO hydrogel films obtained have a nacre-like brick-and-mortar microstructure, which contributes to their excellent mechanical properties. The tensile strength and elongation at break of the hydrogel films with 5wt% GO are 5.35MPa and 193.5%, respectively, which are comparable to natural costal cartilage. Furthermore, the CS/GO hydrogel films exhibited pH-driven shape memory effect, and this unique phenomenon is mainly attributed to the reversible transition of partial physically cross-linking corresponding to hydrogen bondings and hydrophobic interactions between CS polymer chains due to pH changing.

Neurosensory effects of chronic exposure to arsenic via drinking water in Inner Mongolia: II. Vibrotactile and visual function.

This study was designed to assess the effects of exposure to arsenic in drinking water on visual and vibrotactile function in residents of the Bamen region of Inner Mongolia, China. Arsenic was measured by hydride generation atomic fluorescence. 321 participants were divided into three exposure groups- low (non-detectable-20), medium (100-300) and high (400-700 microg/l) arsenic in drinking water (AsW). Three visual tests were administered: acuity, contrast sensitivity and color discrimination (Lanthony's Desaturated 15 Hue Test). Vibration thresholds were measured with a vibrothesiometer. Vibration thresholds were significantly elevated in the high exposure group compared to other groups. Further analysis using a spline regression model suggested that the threshold for vibratory effects is between 150-170 microg/l AsW. These findings provide the first evidence that chronic exposure to arsenic in drinking water impairs vibrotactile thresholds. The results also indicate that arsenic affects neurological function well below the 1000 microg/I concentration reported by NRC (1999). No evidence of arsenic-related effects on visual function was found.