Water Impalement Resistance and Drag Reduction of the Superhydrophobic Surface with Hydrophilic Strips

Superhydrophobic surfaces (SHS) offer versatile applications by trapping an air layer within microstructures, while water jet impact can destabilize this air layer and deactivate the functions of the SHS. The current work presents for the first time that introducing parallel hydrophilic strips to SHS (SHS-s) can simultaneously improve both water impalement resistance and drag reduction (DR). Compared with SHS, SHS-s demonstrates a 125% increase in the enduring time against the impact of water jet with velocity of 11.9 m/s and a 97% improvement in DR at a Reynolds number of 1.4 × 104. The key mechanism lies in the enhanced stability of the air layer due to air confinement by the adjacent three-phase contact lines. These lines not only impede air drainage through the surface microstructures during water jet impact, entrapping the air layer to resist water impalement, but also prevent air floating up due to buoyancy in Taylor-Couette flow, ensuring an even spread of the air layer all over the rotor, boosting DR. Moreover, failure modes of SHS under water jet impact are revealed to be related to air layer decay and surface structure destruction. This mass-producible structured surface holds the potential for widespread use in DR for hulls, autonomous underwater vehicles, and submarines.

Maintenance Therapy for Recurrent or Metastatic Cervical Cancer: A Multicenter, Cohort Study

PURPOSE/OBJECTIVE(S)

Maintenance therapy with alternative agents after chemotherapy was shown to improve the overall survival in some advanced cancers such as breast cancer, lung cancer, ovarian cancer and so on. However, maintenance therapy is not accepted as the standard treatment for recurrent/metastatic cervical cancer. Aim of this study is to elucidate the efficacy of maintenance therapy in cervical cancer and to explore the factors associated with the prognosis of recurrent or metastatic cervical cancer.

MATERIALS/METHODS

In this multicenter cohort study, we retrospectively collected patients with a diagnosis of either recurrent or stage IVB cervical cancer to receive first-line chemotherapy with or without maintenance therapy. Patients did not have disease progression with first-line chemotherapy and were divided into maintenance therapy group (Arm A) and conventional chemotherapy group (Arm B). Information on clinical characteristics, metastasis information, treatment outcome and survival of patients was collected using an electronic medical record system. The endpoints of the study were OS and PFS. Data were analyzed for general characteristics and survival using statistical software, and the results were considered statistically significant at P < 0.05.

RESULTS

Between January 2019 and July 2021, a total of 270 patients were enrolled from 6 institutions in China. 26 patients were excluded because of short treatment cycles (less than 3 cycles). Finally, a total of 66 patients in Arm A and 178 patients in Arm B were analyzed for survival. The addition of maintenance significantly prolonged overall survival. Overall survival at 3 year was 50.1% in Arm A and 27.8% in Arm B (median overall survival, ≥36 months vs. 22 months; P<0. 001). The median progression-free survival was 21 months in Arm A and 14 months in Arm B (P = 0.025). Univariate survival analysis showed that age, maintenance therapy, combined radiotherapy, and number of extra-pelvic metastases were associated with PFS. Further multifactorial analysis showed that maintenance therapy, combined radiotherapy, and number of extra-pelvic metastases were independent prognostic factors for patients with recurrent or metastatic cervical cancer.

CONCLUSION

The addition of maintenance therapy significantly prolonged overall survival as well as progression-free survival in patients with recurrent or metastatic cervical cancer and did not increase the incidence of serious adverse events. It is time to consider maintenance therapy as the standard treatment after conventional chemotherapy for recurrent or metastatic cervical cancer, rather than waiting for disease progression.

Multiple configuration transitions of soft actuators under single external stimulus

Soft actuators have a wide range of applications in medical instruments, soft robotics, 3D electronics, and deployable structures, where configuration transitions are crucial for their function realization. However, most soft actuators can only morph from the initial configuration directly to the final configuration under a single external stimulus. Herein, we report a novel soft actuator by 3D printing parallel strips with crescent cross-sections onto a thin PDMS film. Multiple configuration transitions are observed when the soft actuator swells in ethyl acetate. Four factors, i.e., the geometric asymmetry of the strips, the fabrication-induced heterogeneity of the film, the differential swelling ratios of the strips and the film, and the geometric parameters of the actuator, are demonstrated to synergistically regulate the multiple configuration transitions of the actuator. Particularly, the underlying mechanisms for the configuration transitions are systematically investigated through experiments and theoretical analysis, and verified via finite element simulation. Benefitting from the multiple configuration transitions, the grasp-release-re-grab function of the actuator is demonstrated under a single stimulus. This work contributes to fundamental understanding of the morphing behaviors and the novel design of soft actuators.

[Long-term outcomes of 328 patients with of autism spectrum disorder after fecal microbiota transplantation]

Objective: To evaluate the efficacy and safety of fecal microbiota transplantation (FMT) in the treatment of autism spectrum disorder (ASD). Methods: A longitudinal study was conducted. Clinical data from ASD patients with gastrointestinal symptoms and who underwent FMT in the Tenth People's Hospital affiliated to Tongji University or Jinling Hospital between May 2012 to May 2021 were retrospectively collected. Scores derived from the autism behavior checklist (ABC), the childhood autism rating scale (CARS), the Bristol stool form scale (BSFS), and the gastrointestinal symptom rating scale (GSRS) were analyzed at baseline and at the 1st, 3rd, 6th, 12th, 24th, 36th, 48th and 60th month after FMT. Records of any adverse reactions were collected. Generalized estimating equations were used for analysis of data on time points before and after FMT. Results: A total of 328 patients met the inclusion criteria for this study. Their mean age was 6.1±3.4 years old. The cohort included 271 boys and 57 girls. The percentage of patients remaining in the study for post-treatment follow-up at the 1st, 3rd, 12th, 24th, 36th, 48th and 60th month were as follows: 303 (92.4%), 284 (86.7%), 213 (64.9%), 190 (57.9%), 143 (43.6%), 79 (24.1%), 46 (14.0%), 31 (9.5%). After FMT, the average ABC score was significantly improved in the first 36 months and remained improved at the 48th month. However, the average score was not significantly different from baseline by the 60th month (1st-36th month, P<0.001; 48th month, P=0.008; 60th month, P=0.108). The average CARS score improved significantly during the first 48 months and remained improved at the 60th month (1st-48th month, P<0.001; 60th month, P=0.010). The average BSFS score was also significantly improved in the first 36 months (with an accompanying stool morphology that resembled type 4). This improvement was maintained at the 48th month. However, the average score was similar to baseline at the 60th month (1st-36th month, P<0.001; 48th month, P=0.008; 60th month, P=0.109). The average GSRS score was significantly improved during the first 24 months, but not afterwards (1st-24th month, P<0.001; 36th month, P=0.209; 48th month, P=0.996; 60th month, P=0.668). The adverse events recorded during treatment included abdominal distension in 21 cases (6.4%), nausea in 14 cases (4.3%), vomiting in 9 cases (2.7%), abdominal pain in 15 cases (4.6%), diarrhea in 18 cases (5.5%), fever in 13 cases (4.0%), and excitement in 24 cases (7.3%). All adverse reactions were mild to moderate and improved immediately after suspension of FMT or on treatment of symptoms. No serious adverse reactions occurred. Conclusion: FMT has satisfactory long-term efficacy and safety for the treatment of ASD with gastrointestinal symptoms.

Physically Entangled Anti-Swelling Hydrogels with High Stiffness

Physically crosslinked hydrogels have great potential for tissue engineering because of their excellent biocompatibility and easy fabrication. However, physical crosslinking points are typically weaker compared to chemical ones and therefore cannot form robust hydrogels with excellent water stability, which greatly hinder their further applications. In this work, we report a novel hydrogel with high stiffness and outstanding anti-swelling performance crosslinked by hydrophobic polymer chains entanglements. The hydrophobic polymer polyimide (PI) was mixed with the hydrophilic polymer poly(vinyl pyrrolidone) (PVP) to form crosslinking points between the chains. At the equilibrium swelling state, tensile moduli of the hydrogel can be up to 22.57 MPa (higher than most existing hydrogels) and the equilibrium water swelling ratio (ESR) can be as low as 125.0%. By decreasing the PI mass ratio, tensile moduli and ESR of the hydrogel can be tuned in a wide range from 22.57 MPa to 0.005 MPa and 125.0% to 765.6%, respectively. Using PVP/PI solutions as inks, we fabricate uniform structures and multi-material structures whose mechanical properties are close to cartilage through a direct ink writing 3D printing platform. The current work demonstrates that entangled PVP/PI hydrogels have excellent tailoring capabilities and are promising candidates for tissue engineering applications. This article is protected by copyright. All rights reserved.

A micromechanical model for phase-change composites

Phase-change composites have a wide range of tunable mechanical properties caused by temperature-driven phase transition, and have been widely applied in many cutting-edge fields like soft robotics. Previous studies on the effective mechanical properties of phase-change composites mostly use experimental methods, and there have been few theoretical approaches. In this work, we develop a micromechanical framework capable of tracking the effective mechanical properties of phase-change composites throughout the entire phase transition. The phase-change materials embedded in the composites are modelled as inclusions, and the non-phase-change materials are modelled as the matrix. This allows us to determine the effective mechanical properties of phase-change composites via the energy equivalency approach. Moreover, since the new phase will be generated inside the phase-change inclusions in the form of sub-inclusions during the phase transition, the inclusions are modelled as two-phase composites, and their effective mechanical properties are then determined using the Mori–Tanaka method. Finally, by comparing theoretical predictions with experimental data, the accuracy and reliability of the present model are verified. We believe that the proposed model can serve as a powerful tool for evaluating the effective mechanical properties of phase-change composites and provide theoretical guidelines for the design of advanced devices with tunable mechanical performance.

Graphene Oxide Aerogel Foam Constructed All-Solid Electrolyte Membranes for Lithium Batteries

With the development of electric vehicles and products, lithium metal batteries with solid-state electrolytes have shown a broad application prospect. However, the uneven deposition of lithium, low ion conductivity, narrow electrochemical window, and high interfacial impedance limit the safety and performance of the solid-state batteries. Herein, we develop a non-ceramic solid electrolyte based on the graphene oxide aerogel frame filling with polyethylene oxide (GSPE). The resulting uniform and resilient framework structure form a continuous Li-ion adsorption zone, which ensures uniform ion-current distribution at the interface while obtaining the relatively high ionic conductivity, effectively preventing the uneven deposition of lithium, and thus greatly improving the battery stability. Comprehensive electrochemical analysis showed that GSPE achieved an ionic conductivity of 4.12 × 10^-4 S cm^-1 at 50 °C. The assembled LiFePO₄(LFP) |GSPE| Li full battery can stably cycle for more than 100 cycles at 0.1 C, and the lithium symmetrical battery can continuously be plating-peeling for more than 600 h at 0.1 mA cm^-2. The method of using the carbon aerogel structure to achieve the uniform deposition of lithium ions has explored a new possible research direction for all-solid-state batteries.

Conical Kresling origami and its applications to curvature and energy programming

Kresling origami has recently been widely used to design mechanical metamaterials, soft robots and smart devices, benefiting from its bistability and compression-twist coupling deformation. However, previous studies mostly focus on the traditional parallelogram Kresling patterns which can only be folded to cylindrical configurations. In this paper, we generalize the Kresling patterns by introducing free-form quadrilateral unit cells, leading to diverse conical folded configurations. The conical Kresling origami is modelled with a truss system, by which the stable states and energy landscapes are derived analytically. We find that the generalization preserves the bistable nature of parallelogram Kresling patterns, while enabling an enlarged design space of geometric parameters for structural and mechanical applications. To demonstrate this, we develop inverse design frameworks to employ conical Kresling origami to approximate arbitrary target surfaces of revolution and achieve prescribed energy landscapes. Various numerical examples obtained from our framework are presented, which agree well with the paper models and the finite-element simulations. We envision that the proposed conical Kresling pattern and inverse design framework can provide a new perspective for applications in deployable structures, shape-morphing devices, multi-modal robots and multistable metamaterials.

Self-Propelled Detachment upon Coalescence of Surface Bubbles

The removal of microbubbles from substrates is crucial for the efficiency of many catalytic and electrochemical gas evolution reactions in liquids. The current work investigates the coalescence and detachment of bubbles generated from catalytic decomposition of hydrogen peroxide. Self-propelled detachment, induced by the coalescence of two bubbles, is observed at sizes much smaller than those determined by buoyancy. Upon coalescence, the released surface energy is partly dissipated by the bubble oscillations, working against viscous drag. The remaining energy is converted to the kinetic energy of the out-of-plane jumping motion of the merged bubble. The critical ratio of the parent bubble sizes for the jumping to occur is theoretically derived from an energy balance argument and found to be in agreement with the experimental results. The present results provide both physical insight for the bubble interactions and practical strategies for applications in chemical engineering and renewable energy technologies like electrolysis.

Origami Spring-Inspired Shape Morphing for Flexible Robotics

Flexible robotics are capable of achieving various functionalities by shape morphing, benefiting from their compliant bodies and reconfigurable structures. In this study, we construct and study a class of origami springs generalized from the known interleaved origami spring, as promising candidates for shape morphing in flexible robotics. These springs are found to exhibit nonlinear stretch-twist coupling and linear/nonlinear mechanical response in the compression/tension region, analyzed by the demonstrated continuum mechanics models, experiments, and finite element simulations. To improve the mechanical performance such as the damage resistance, we establish an origami rigidization method by adding additional creases to the spring system. Guided by the theoretical framework, we experimentally realize three types of flexible robotics-origami spring ejectors, crawlers, and transformers. These robots show the desired functionality and outstanding mechanical performance. The proposed concept of origami-aided design is expected to pave the way to facilitate the diverse shape morphing of flexible robotics.

Intelligent Shape-Morphing Micromachines

Intelligent machines are capable of switching shape configurations to adapt to changes in dynamic environments and thus have offered the potentials in many applications such as precision medicine, lab on a chip, and bioengineering. Even though the developments of smart materials and advanced micro/nanomanufacturing are flouring, how to achieve intelligent shape-morphing machines at micro/nanoscales is still significantly challenging due to the lack of design methods and strategies especially for small-scale shape transformations. This review is aimed at summarizing the principles and methods for the construction of intelligent shape-morphing micromachines by introducing the dimensions, modes, realization methods, and applications of shape-morphing micromachines. Meanwhile, this review highlights the advantages and challenges in shape transformations by comparing micromachines with the macroscale counterparts and presents the future outlines for the next generation of intelligent shape-morphing micromachines.

Expression of lncRNA AK058003 in esophageal carcinoma and analysis of its intervention effect

OBJECTIVE

The aim of this study was to investigate the expression of long non-coding ribonucleic acid (lncRNA) AK058003 in esophageal carcinoma (EC) tissues, and to analyze its intervention effect.

PATIENTS AND METHODS

The expression of lncRNA AK058003 in EC tissues and para-carcinoma tissues from 130 EC patients was detected via quantitative Polymerase Chain Reaction (qPCR). EC cell lines were selected for exogenous interference in lncRNA AK058003. Subsequently, the expression of lncRNA AK058003 in normal esophageal epithelial cell line (Het-1A) and EC cell lines (EC109, EC9706, KYSE-150, KYSE-30, and TE-1) was detected by qPCR. EC9706 cell lines with the highest expression of lncRNA AK058003 were selected and transfected with lncRNA AK058003 siRNA and lncRNA AK058003 control, respectively. After transfection, the expression of lncRNA AK058003 was determined using PCR. The changes in cell growth and proliferation were analyzed via cell growth curve and cell cycle assay. Meanwhile, the changes in cell migration and invasion were analyzed through wound healing assay. Protein expressions of matrix metalloproteinase-1 (MMP1) and MMP2 were determined by Western blot. Clinical data were collected from EC patients, and the association between lncRNA AK058003 expression and tumor-node-metastasis (TNM) stage was finally analyzed.

RESULTS

LncRNA AK058003 was highly expressed EC tissues compared with para-carcinoma tissues (p<0.01). Compared with Het-1A cells, the expression of lncRNA AK058003 was significantly higher in EC109, EC9706, KYSE-150, KYSE-30, and TE-1 cells, with highest level in EC9706 cells (p<0.05). The expression of lncRNA AK058003 remarkably declined in lncRNA AK058003 siRNA group compared with lncRNA AK058003 control group (p<0.001). Compared with lncRNA AK058003 control group, the proliferation of EC cells was significantly weakened in lncRNA AK058003 siRNA group, with the greatest difference at 3 d. Flow cytometry results revealed that cell cycle was arrested in G0/G1 phase in lncRNA AK058003 siRNA group. Wound healing assay indicated that the intercellular distance became large, and cell migration ability was evidently enhanced in lncRNA AK058003 siRNA group with time (p<0.05). Besides, the protein expressions of MMP1 and MMP2 were remarkably lower in lncRNA AK058003 siRNA group than those in lncRNA AK058003 control group. This indicated remarkably declined invasion and metastasis ability. In addition, the postoperative prognosis was significantly worse in patients with higher expression of lncRNA AK058003 (p<0.05). All these findings suggested that lncRNA AK058003 could serve as a biomarker for EC prognosis.

CONCLUSIONS

LncRNA AK058003 is highly expressed in EC patients, which promotes proliferation, migration, invasion, and metastasis of EC cells. In addition, the postoperative prognosis of EC patients with high expression of lncRNA AK058003 is relatively poor.

miR-382-3p Overexpression attenuates N-methyl-D-aspartate-induced HT22 cell apoptosis via the regulation of the RhoC/ROCK1 signaling pathway

miR-382-3p can regulate apoptosis through multiple pathways, but the mechanism remains unknown. In this experiment, we explored whether miR-382-3p can modulate the N-methyL-D-aspartate (NMDA)- induced HT22 cell apoptosis by regulating the RhoC/ROCK1 signaling pathway. An excitatory neurotoxicity model of HT22 cells was induced in vitro with 2 mmol/L NMDA. The cells were divided into normal control, NMDA-induced, NMDA + miR-382-3p mimic, and NMDA + miR-382-3p inhibitor groups. The 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) method, Real-time PCR, Western blot, and flow cytometry were performed to investigate the mechanisms. The results found that NMDA can increase the oxidative stress of HT22 cells in a dose-dependent manner, downregulate the expression of miR-382-3p, upregulate the expression of mRNA and protein abundance of ROCK1 and RhoC, increase the expression levels of proapoptotic proteins Bax, Caspase-3, and Caspase-9, increase the apoptosis of HT22 cells, and reduce the activity and survival rate of HT22 cells. Compared with the NMDA-induced group, the miR-382-3p mimic-transfected HT22 cells increased the expression of miR- 382-3p, reduced the expression of the mRNA and protein abundance of ROCK1 and RhoC, inhibited the expression of proapoptotic proteins Bax, Caspase-3, and Caspase-9, reduced the apoptosis of HT22 cells, and increased the activity and survival rate of HT22 cells. The results suggest that increasing the expression of miR-382-3p can inhibit the activity of the RhoC/ROCK1 signaling pathway, reduce the expression of proapoptotic proteins, reduce the oxidative stress and apoptosis of HT22 cells, and increase the activity and survival rate of HT22 cells.

Display of quintuple glucagon-like peptide 1 (28-36) nonapeptide on Bacillus subtilis spore for oral administration in the treatment of type 2 diabetes

AIMS

To develop an oral delivery system of glucagon-like peptide 1 (GLP-1) (28-36) for treating type-2 diabetes, B.S-GLP-1(28-36), a recombinant Bacillus subtilis spores transformed with a plasmid vector encoding five consecutive GLP-1 (28-36) nonapeptides with an enterokinase site was constructed.

METHODS AND RESULTS

GLP-1(28-36) nonapeptide was successfully expressed on the surface of B. subtilis spores and validated by Western blot and immunofluorescence. The therapeutic effect of oral administration of B.S-GLP-1(28-36) spores was evaluated in type 2 diabetic model mice. The efficacy of recombinant spores was examined for a period of 13 weeks after oral administration in diabetic mice. At the end of the sixth week, diabetic mice with oral administration of BS-GLP-1(28-36) spores showed decreased blood glucose levels from 2·4 × 10^{- 2}  mol l^-1 to 1·7 × 10^{- 2}  mol l^-1 . By the ninth week, the mean fasting blood glucose level in the experimental group was significantly lower than that in the control group 30 min after injection of pyruvate. At the end of the 10th week of oral administration, the blood glucose of the experimental group was significantly lower than that of the control group after intraperitoneal injection of glucose. By the 12th week, fasting blood glucose level and fasting insulin level were measured in all mice, the results showed that the recombinant spores increased the insulin sensitivity of mice.

CONCLUSIONS

The results of pathological observation showed that the recombinant spores also had a certain protective effect on the liver and islets of mice, and the content of GLP-1(28-36) in the pancreas of the experimental group was increased.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study revealed that GLP-1(28-36) nonapeptides can reduce blood glucose and play an important role in the treatment of type 2 diabetes.

Soft Actuators Based on Liquid-Vapor Phase Change Composites

Liquid-vapor phase change materials (PCMs), capable of significant volume change, are emerging as attractive actuating components in forming advanced soft composites for robotic applications. However, the novel and functional design of these PCM composites is significantly limited due to the lacking of the fundamental understanding of the mechanical properties, which further inhibits the broad applications of PCM based materials in the engineering structures requiring large deformation and high loading capacity. In this study we fabricate PCM-elastomer composites exhibiting large deformation and high output stress. Thermomechanical properties of these composites are experimentally and theoretically investigated, demonstrating enhanced deformation and loading capacity due to the induced vapor pressure. By controlling the distribution and content of the PCM inclusions, structures with tunable deformability under a relatively small strain in comparison with traditional soft materials are fabricated. Accompanying with the asymmetrical friction and deformation, complex locomotion and adaptable grabbing function are achieved with excellent performance.

Efficient production of coenzyme Q10 from acid hydrolysate of sweet sorghum juice by Rhodobacter sphaeroides

In order to achieve efficient bioconversion of biomass-derived sugars, acid hydrolysate of sweet sorghum juice (SSJAH) containing abundant fermentable sugars was used for coenzyme Q10 (CoQ10) fermentation by Rhodobacter sphaeroides CQ-09-1. The synthesis of CoQ10 was facilitated when the initial concentration of total sugar was 80.00 g L-1. And the highest CoQ10 titer was obtained when the pH and temperature were maintained at 7.00 and 30.00 °C, respectively. Moreover, corn steep powder (CSP) was proved to be an efficient nitrogen & salt supplement to SSJAH. Under the optimized conditions, the titer of CoQ10 reached 141.95 mg L-1 in a fed-batch fermentation. The CoQ10 titer reported was about two times higher than that obtained in the previous study using wild strains. This process introduces a potential way to produce CoQ10 using the concept of biorefinery, while making full use of sweet sorghum juice (SSJ).

Gravitational Effect in Evaporating Binary Microdroplets

The flow in an evaporating glycerol-water binary submillimeter droplet with a Bond number Bo≪1 is studied both experimentally and numerically. First, we measure the flow fields near the substrate by microparticle image velocimetry for both sessile and pendant droplets during the evaporation process, which surprisingly show opposite radial flow directions-inward and outward, respectively. This observation clearly reveals that in spite of the small droplet size, gravitational effects play a crucial role in controlling the flow fields in the evaporating droplets. We theoretically analyze that this gravity-driven effect is triggered by the lower volatility of glycerol which leads to a preferential evaporation of water then the local concentration difference of the two components leads to a density gradient that drives the convective flow. We show that the Archimedes number Ar is the nondimensional control parameter for the occurrence of the gravitational effects. We confirm our hypothesis by experimentally comparing two evaporating microdroplet systems, namely, a glycerol-water droplet and a 1,2-propanediol-water droplet. We obtain different Ar, larger or smaller than a unit by varying a series of droplet heights, which corresponds to cases with or without gravitational effects, respectively. Finally, we simulate the process numerically, finding good agreement with the experimental results and again confirming our interpretation.

Multimaterial Microfluidic 3D Printing of Textured Composites with Liquid Inclusions

3D printing with a high degree of spatial and compositional precision could open new avenues to the design and fabrication of functional composites. By combining the direct ink writing and microfluidics, a multimaterial 3D printing system for fabricating textured composites with liquid inclusions of programmable spatial distribution and compositions is reported here. Phase diagrams for the rational selection of desired printing parameters are determined through a combination of simple theoretical analysis and experimental studies. 1D, 2D, and 3D structures programmed with desired inclusion patterns and compositions are fabricated. Moreover, the versatility of this 3D printing framework in fabricating layered composite beams of tunable thermal property and self-healing materials is demonstrated. The proposed multimaterial microfluidic 3D printing framework could be broadly applicable for structural composites and soft robotic devices.

Phosphoproteome profiling revealed abnormally phosphorylated AMPK and ATF2 involved in glucose metabolism and tumorigenesis of GH-PAs

PURPOSE

Protein phosphorylation plays a key role in tumorigenesis and progression. However, little is known about the phosphoproteome profiles of growth hormone-secreting pituitary adenomas (GH-PAs). The aim of this study was to identify critical biomarkers and signaling pathways that might play important roles in GH-PAs and may, therefore, represent potential therapeutic targets.

METHODS

The differential phosphoprotein expression patterns involved in GH-PAs were investigated by nano-LC-MS/MS in a group of samples. The phosphoprotein expression data were analyzed by bioinformatics. The expression levels of the candidate phosphorylated AMPK (ser496) and ATF2 (ser112) were validated by Western blot analysis in another group of samples.

RESULTS

A total of 1213 phosphorylated protein sites corresponding to 667 proteins were significantly different between GH-PAs and healthy pituitary glands. Among these phosphorylated sites, 871 exhibited lower levels of phosphorylation in GH-PAs. Moreover, 140 novel phosphosites corresponding to 93 proteins were differentially phosphorylated between GH-PAs and healthy pituitary glands, 101 of which showed decreased phosphorylation in GH-PAs. The majority of differentially expressed phosphorylated proteins were significantly enriched in glycolysis and the AMPK signaling pathway in GH-PAs. The AMPK signaling pathway was demonstrated to be inhibited in GH-PAs by pathway activity analysis (z score = - 2.324). Notably, the phosphorylated levels of AMPK (ser496) and ATF2 (ser112) were significantly lower in GH-PAs than in healthy pituitary glands.

CONCLUSION

These findings suggest that decreased phosphorylation of the AMPK/ATF2 pathway may be critical for glucose metabolism and tumorigenesis in GH-PAs.

3D Black-Blood Luminal Angiography Derived from High-Resolution MR Vessel Wall Imaging in Detecting MCA Stenosis: A Preliminary Study

BACKGROUND AND PURPOSE

3D high-resolution vessel wall imaging is increasingly used for intracranial arterial diseases. This study compared the diagnostic performance of black-blood luminal angiography derived from 3D vessel wall imaging with source images of vessel wall imaging and TOF-MRA in detecting middle cerebral artery stenosis.

MATERIALS AND METHODS

Sixty-two patients with suspected MCA atherosclerosis underwent TOF-MRA, vessel wall imaging, and CTA. Intracranial black-blood luminal angiography was created from source images of vessel wall imaging using minimum intensity projection. The degree and length of MCA stenosis were measured on source images of vessel wall imaging, TOF-MRA, and black-blood luminal angiography and compared using CTA as a reference standard.

RESULTS

The image quality of black-blood luminal angiography was diagnostic in most patients. The intra- and interobserver agreement for both stenosis degree and length measurements was excellent for black-blood luminal angiography. It was comparable with that of source images of vessel wall imaging in grading stenosis. Compared with TOF-MRA, black-blood luminal angiography showed significantly higher sensitivity for the detection of severe stenosis (89.3% versus 64.3%, P = .039) and higher specificity for the detection of occlusion (95.4% versus 84.6%, P = .039). Lesion length estimated on source images of vessel wall imaging was significantly greater than that measured by CTA and black-blood luminal angiography (P < .001 and P = .010).

CONCLUSIONS

Black-blood luminal angiography is better than TOF-MRA in detecting severe stenosis and occlusion of the MCA. Compared with source images of vessel wall imaging, it is more accurate in evaluating stenosis length. Black-blood luminal angiography can be produced as a derivative from vessel wall imaging and implemented as an adjunct to vessel wall imaging and TOF-MRA without extra acquisition time.

Evaporation-Triggered Segregation of Sessile Binary Droplets

Droplet evaporation of multicomponent droplets is essential for various physiochemical applications, e.g., in inkjet printing, spray cooling, and microfabrication. In this work, we observe and study the phase segregation of an evaporating sessile binary droplet, consisting of a miscible mixture of water and a surfactantlike liquid (1,2-hexanediol). The phase segregation (i.e., demixing) leads to a reduced water evaporation rate of the droplet, and eventually the evaporation process ceases due to shielding of the water by the nonvolatile 1,2-hexanediol. Visualizations of the flow field by particle image velocimetry and numerical simulations reveal that the timescale of water evaporation at the droplet rim is faster than that of the Marangoni flow, which originates from the surface tension difference between water and 1,2-hexanediol, eventually leading to segregation.

A Modular Microfluidic Device via Multimaterial 3D Printing for Emulsion Generation

3D-printing (3DP) technology has been developing rapidly. However, limited studies on the contribution of 3DP technology, especially multimaterial 3DP technology, to droplet-microfluidics have been reported. In this paper, multimaterial 3D-printed devices for the pneumatic control of emulsion generation have been reported. A 3D coaxial flexible channel with other rigid structures has been designed and printed monolithically. Numerical and experimental studies have demonstrated that this flexible channel can be excited by the air pressure and then deform in a controllable way, which can provide the active control of droplet generation. Furthermore, a novel modular microfluidic device for double emulsion generation has been designed and fabricated, which consists of three modules: function module, T-junction module, and co-flow module. The function module can be replaced by (1) Single-inlet module, (2) Pneumatic Control Unit (PCU) module and (3) Dual-inlet module. Different modules can be easily assembled for different double emulsion production. By using the PCU module, double emulsions with different number of inner droplets have been successfully produced without complicated operation of flow rates of different phases. By using single and dual inlet module, various double emulsions with different number of encapsulated droplets or encapsulated droplets with different compositions have been successfully produced, respectively.

Liquid-liquid displacement in slippery liquid-infused membranes (SLIMs)

Liquid-infused membranes inspired by slippery liquid-infused porous surfaces (SLIPS) have been recently introduced to membrane technology. The gating mechanism of these membranes is expected to give rise to anti-fouling properties and multi-phase transport capabilities. However, the long-term retention of the infusion liquid has not yet been explored. To address this issue, we investigate the retention of the infusion liquid in slippery liquid-infused membranes (SLIMs) via liquid-liquid displacement porometry (LLDP) experiments combined with microscopic observations of the displacement mechanism. Our results reveal that pores will be opened corresponding to the capillary pressure, leading to preferential flow pathways for water transport. The LLDP results further suggest the presence of liquid-lined pores in SLIM. This hypothesis is analyzed theoretically using an interfacial pore flow model. We find that the displacement patterns correspond to capillary fingering in immiscible displacement in porous media. The related physics regarding two-phase flow in porous media is used to confirm the permeation mechanism appearing in SLIMs. In order to experimentally observe liquid-liquid displacement, a microfluidic chip mimicking a porous medium is designed and a highly ramified structure with trapped infusion liquid is observed. The remaining infusion liquid is retained as pools, bridges and thin films around pillar structures in the chip, which further confirms liquid-lining. Fractal dimension analysis, along with evaluation of the fluid (non-wetting phase) saturation, further confirms that the fractal patterns correspond to capillary fingering, which is consistent with an invasion percolation with trapping (IPT) model.

Effect of in ovo feeding of l-arginine on the hatchability, growth performance, gastrointestinal hormones, and jejunal digestive and absorptive capacity of posthatch broilers

This study was conducted to investigate the effects of in ovo feeding (IOF) of Arg solution on the hatchability, growth performance, gastrointestinal hormones, serum AA, activities of digestive enzymes, and mRNA expressions of sensing receptors and nutrient transporters in the jejunum of posthatch broilers. One thousand two hundred embryonated eggs with similar weight were randomly allocated to 5 groups consisting of 8 replicates of 40 eggs each. The 5 treatments were arranged as a noninjected control, a diluent-injected (0.75% NaCl solution) group, and Arg solution-injected groups with 0.5%, 1.0%, and 2.0% Arg, all dissolved in diluent. At 17.5 d of incubation, 0.6 mL of IOF solution was injected into the amniotic fluid of each egg of the injected groups. Results showed the hatchability of the 2% Arg group was lower (linear, = 0.025) than that of the other groups, and the BW of 21-d-old broilers increased (linear, = 0.008; quadratic, = 0.003) with increasing IOF concentration of Arg. The ADFI (linear, = 0.005; quadratic, = 0.001) and ADG (linear, = 0.010; quadratic, = 0.004) increased during d 1 to 21 with increasing IOF concentration of Arg. For 7- and 21-d-old broilers, the weights of digestive organs increased (linear, < 0.05) with increasing IOF concentrations of Arg; the greatest values were observed in the 1% Arg group. For 21-d-old broilers, IOF of the 1% Arg solution increased ( < 0.05) the concentrations of ghrelin and glucagon-like peptide 2; the activities of digestive enzymes, alkaline phosphatase, maltase, and sucrase in the jejunum; and the concentrations of serum AA of Val, Met, Ile, Leu, Arg, and Pro compared with those of the noninjected control and diluent-injected group. In ovo feeding of the 1% Arg solution also increased ( < 0.05) the mRNA expressions of jejunal sensing receptors of taste receptor type 1 members 1 and 3; the G protein-coupled receptor, class C, group 6, subtype A; nutrient transporters of solute carrier family 7, members 4, 6, and 7; sodium-glucose transporter 1; and fatty acid-binding protein 1. In conclusion, the 1% Arg solution was the appropriate injection level. In ovo feeding of the 1% Arg solution did not affect the hatchability but facilitated the release of gastrointestinal hormones, increasing the digestive and absorptive capacity and finally improving the growth performance of 21-d-old broilers. Therefore, IOF of the appropriate Arg solution could be an effective technology for regulating early nutrition supply and subsequent growth development in the poultry industry.

Ultimate Stable Underwater Superhydrophobic State

Underwater metastability hinders the durable application of superhydrophobic surfaces. In this work, through thermodynamic analysis, we theoretically demonstrate the existence of an ultimate stable state on underwater superhydrophobic surfaces. Such a state is achieved by the synergy of mechanical balance and chemical diffusion equilibrium across the entrapped liquid-air interfaces. By using confocal microscopy, we in situ examine the ultimate stable states on structured hydrophobic surfaces patterned with cylindrical micropores in different pressure and flow conditions. The equilibrium morphology of the meniscus is tuned by the dissolved gas saturation degree within a critical range at a given liquid pressure. Moreover, with fresh lotus leaves, we prove that the ultimate stable state can also be realized on randomly rough superhydrophobic surfaces. The finding here paves the way for applying superhydrophobic surfaces in environments with different liquid pressure and flow conditions.

Growth and Detachment of Oxygen Bubbles Induced by Gold-Catalyzed Decomposition of Hydrogen Peroxide

Whereas bubble growth out of gas-oversatured solutions has been quite well understood, including the formation and stability of surface nanobubbles, this is not the case for bubbles forming on catalytic surfaces due to catalytic reactions, though it has important implications for gas evolution reactions and self-propulsion of micro/nanomotors fueled by bubble release. In this work we have filled this gap by experimentally and theoretically examining the growth and detachment dynamics of oxygen bubbles from hydrogen peroxide decomposition catalyzed by gold. We measured the bubble radius R(t) as a function of time by confocal microscopy and find R(t) ∝ t^1/2. This diffusive growth behavior demonstrates that the bubbles grow from an oxygen-oversaturated environment. For several consecutive bubbles detaching from the same position in a short period of time, a well-repeated growing behavior is obtained from which we conclude the absence of noticeable depletion effect of oxygen from previous bubbles or increasing oversaturation from the gas production. In contrast, for two bubbles far apart either in space or in time, substantial discrepancies in their growth rates are observed, which we attribute to the variation in the local gas oversaturation. The current results show that the dynamical evolution of bubbles is influenced by comprehensive effects combining chemical catalysis and physical mass transfer. Finally, we find that the size of the bubbles at the moment of detachment is determined by the balance between buoyancy and surface tension and by the detailed geometry at the bubble's contact line.

Receding dynamics of contact lines and size-dependent adhesion on microstructured hydrophobic surfaces

The microstructure size on textured surfaces of a given solid fraction exhibits an important effect on their properties. To understand the size effect on surface adhesion, we study the receding dynamics of the microscopic three-phase contact lines, the adhesive properties, and the relation between them on microstructured surfaces. Two types of surfaces are used, which are micropillar and micropore, respectively. First, the receding process of the contact line is directly observed by laser scanning confocal microscopy (LSCM), which shows distinct characteristics on the two types of surfaces. The micro contact line experiences pinnning, sliding, and rupture on micropillar-patterned surfaces while no rupture occurs on micropore-patterned surfaces. The three-dimensional morphology of the micromeniscus on the micropillared surfaces and the two-dimensional scanning of the cross-sections of the micromeniscus along the diagonal direction are imaged. Based on the images, the local contact angles around the micropillar at the receding front, and the curvatures of the micro-meniscus are obtained. Then, the adhesive force on these surfaces is measured, which surprisingly shows an increasing trend with the size of the microstructure for micropillared surfaces but no obvious size dependence for micropored surfaces. Wetting hysteresis is also measured to testify the similar trend with the size for the two types of surfaces. Further investigation shows that the monotonic increase of the adhesive force with the increasing size of micropillars is due to the growing difficulty of the detachment of the contact lines. The underlying mechanism responsible for the size dependence of the adhesive force is the enhancement of the local reduced pressure exerted on the top of the micropillar with increasing size, resulting from the concave profile of the outer micromeniscus.

Influence of fluid flow on the stability and wetting transition of submerged superhydrophobic surfaces

Superhydrophobic surfaces have attracted great attention for drag reduction application. However, these surfaces are subject to instabilities, especially under fluid flow. In this work, we in situ examine the stability and wetting transition of underwater superhydrophobicity under laminar flow conditions by confocal microscopy. The absolute liquid pressure in the flow channel is regulated to acquire the pinned Cassie-Baxter and depinned metastable states. The subsequent dynamic evolution of the meniscus morphology in the two states under shear flow is monitored. It is revealed that fluid flow does not affect the pressure-mediated equilibrium states but accelerates the air exchange between entrapped air cavities and bulk water. A diffusion-based model with varying effective diffusion lengths is used to interpret the experimental data, which show a good agreement. The Sherwood number representing the convection-enhanced mass transfer coefficient is extracted from the data, and is found to follow a classic 1/3-power-law relation with the Reynolds number as has been discovered in channel flows with diffusive boundary conditions. The current work paves the way for designing durable superhydrophobic surfaces under flow conditions.

Uptake of 2,4-bis(Isopropylamino)-6-methylthio-s-triazine by Vetiver Grass (Chrysopogon zizanioides L.) from Hydroponic Media

2,4-bis(Isopropylamino)-6-methylthio-s-triazine (prometryn) poses a risk to aquatic environments in several countries, including China, where its use is widespread, particularly due to its chemical stability and biological toxicity. Vetiver grass (Chrysopogon zizanioides L.) was tested for its potential for phytoremediation of prometryn. Vetiver grass was grown in hydroponic media in a greenhouse, in the presence of prometryn, with appropriate controls. Plant uptake and removal of prometryn from the media were monitored for a period of 67 days. The results showed that the removal of the prometryn in the media was expedited by vetiver grass. The removal half-life (t1/2) was shortened by 11.5 days. Prometryn removal followed first-order kinetics (Ct = 1.8070e(-0.0601t)). This study demonstrated the potential of vetiver grass for the phytoremediation for prometryn.

Liquid plasticine: controlled deformation and recovery of droplets with interfacial nanoparticle jamming

Air-exposed droplet systems are widely applied in material preparation and experimental design. Recently, a droplet system with unusual properties featured by a liquid-like appearance and solid-like deformability was produced. However, it was then just an interesting and perplexing phenomenon in the absence of basic understandings and clear perspectives for applications. Here we reveal that stable droplet deformation is attributed to monolayer nanoparticle jamming at the water/vapor interface, and that the normal shape can be recovered by jamming relieving. The degree of jamming affects the droplet shape and transparency and can be tuned by the squeezing force and droplet volume. Using these properties and control methods, we develop the deformed droplet into "liquid plasticine" with predesigned shapes, super-high transparency, and arbitrarily large volume. We demonstrate that liquid plasticine could be used as liquid lenses, channel-like containers, and miniature reactors.

Quantitative combination of natural anti-oxidants prevents metabolic syndrome by reducing oxidative stress

Insulin resistance and abdominal obesity are present in the majority of people with the metabolic syndrome. Antioxidant therapy might be a useful strategy for type 2 diabetes and other insulin-resistant states. The combination of vitamin C (Vc) and vitamin E has synthetic scavenging effect on free radicals and inhibition effect on lipid peroxidation. However, there are few studies about how to define the best combination of more than three anti-oxidants as it is difficult or impossible to test the anti-oxidant effect of the combination of every concentration of each ingredient experimentally. Here we present a math model, which is based on the classical Hill equation to determine the best combination, called Fixed Dose Combination (FDC), of several natural anti-oxidants, including Vc, green tea polyphenols (GTP) and grape seed extract proanthocyanidin (GSEP). Then we investigated the effects of FDC on oxidative stress, blood glucose and serum lipid levels in cultured 3T3-L1 adipocytes, high fat diet (HFD)-fed rats which serve as obesity model, and KK-ay mice as diabetic model. The level of serum malondialdehyde (MDA) in the treated rats was studied and Hematoxylin-Eosin (HE) staining or Oil red slices of liver and adipose tissue in the rats were examined as well. FDC shows excellent antioxidant and anti-glycation activity by attenuating lipid peroxidation. FDC determined in this investigation can become a potential solution to reduce obesity, to improve insulin sensitivity and be beneficial for the treatment of fat and diabetic patients. It is the first time to use the math model to determine the best ratio of three anti-oxidants, which can save much more time and chemical materials than traditional experimental method. This quantitative method represents a potentially new and useful strategy to screen all possible combinations of many natural anti-oxidants, therefore may help develop novel therapeutics with the potential to ameliorate the worldwide metabolic abnormalities.

Symmetric and asymmetric meniscus collapse in wetting transition on submerged structured surfaces

The wetting transition from the Cassie-Baxter to the Wenzel state is a phenomenon critically pertinent to the functionality of microstructured superhydrophobic surfaces. This work focuses on the last stage of the transition, when the liquid-gas interface touches the bottom of the microstructure, which is also known as the "collapse" phenomenon. The process was examined in situ on a submerged surface patterned with cylindrical micropores using confocal microscopy. Both symmetric and asymmetric collapses were observed. The latter significantly shortens the progression of the metastable state prior to the collapse when compared with the former and hence may affect the lifespan of superhydrophobicity. Further experiments identified that asymmetric collapse were induced by impurities due to prior use of the structure. The problem is thus of broad relevance, since endurance through cycles is a practical requirement for these functional surfaces. Finally, the use of hierarchical structures is proposed as a remedy. The embedded self-cleaning mechanism serves to effectively remove the impurities, so as to avoid the triggering mechanism for asymmetric collapses.

Stress fields in hollow core–shell spherical electrodes of lithium ion batteries

This paper presents a comprehensive model coupling the effects of hydrostatic stress, surface/interface stress, phase transformation and the structure of electrodes. First, the governing equation of moving phase interface with hydrostatic stress is established. Under the effect of hydrostatic stress, phase transformation process is much faster, which means phase transformation time is overestimated in previous publications. Then, a cross-scale analysis is presented to investigate the size effect owing to hydrostatic stress, surface stress and interface stress separately, which concludes that the effect of hydrostatic stress is significant for the stress field in microelectrode particles, whereas that of surface/interface stress is highlighted in nano-ones. Finally, an electrochemical variable ‘efficiency’ (ratio of effective capacity over total capacity) is defined. The advantages of hollow structure electrodes on stress and efficiency are analysed. The present model is helpful for the material and structure design of electrodes of lithium ion batteries.

Detection of carotid artery stenosis: a comparison between 2 unenhanced MRAs and dual-source CTA

BACKGROUND AND PURPOSE

Dual-source CTA and black-blood MRA are recently developed techniques for evaluating carotid stenosis. The purpose of this study was to compare dual-source CTA with black-blood MRA and conventional TOF MRA in both detecting carotid stenosis by using DSA as a reference standard and demonstrating plaque morphology.

MATERIALS AND METHODS

Thirty patients with suspected carotid artery stenosis underwent unenhanced MRA by using black-blood and TOF MRA and dual-source CTA. Source images from unenhanced MRAs and dual-source CTA were reconstructed with MIP or curved planar reconstruction. The degree of carotid artery stenosis was measured, and plaque surface morphology at the stenosis was analyzed and compared among different techniques.

RESULTS

Good correlation was observed for measuring the degree of carotid stenosis among dual-source CTA, black-blood MRA, TOF MRA, and DSA. Sensitivity and specificity for detecting severe stenosis were 100% and 97% with dual-source CTA, 100% and 95% with black-blood MRA, and 79% and 95% with TOF MRA. None of the 3 technologies resulted in stenosis of <50% being overestimated. Plaque surface irregularity or ulceration was more frequently detected with dual-source CTA and black-blood MRA than with TOF MRA and DSA.

CONCLUSIONS

This preliminary study shows that black-blood MRA is a promising technique, comparable with dual-source CTA and DSA, but better than TOF MRA, in the evaluation of carotid stenosis. Unlike dual-source CTA, black-blood MRA requires no intravenous contrast or radiation.

Metastable states and wetting transition of submerged superhydrophobic structures

Superhydrophobicity on structured surfaces is frequently achieved via the maintenance of liquid-air interfaces adjacent to the trapped air pockets. These interfaces, however, are subject to instabilities due to the Cassie-Baxter-to-Wenzel transition and total wetting. The current work examines in situ liquid-air interfaces on a submerged surface patterned with cylindrical micropores using confocal microscopy. Both the pinned Cassie-Baxter and depinned metastable states are directly observed and measured. The metastable state dynamically evolves, leading to a transition to the Wenzel state. This process is extensively quantified under different ambient pressure conditions, and the data are in good agreement with a diffusion-based model prediction. A similarity law along with a characteristic time scale is derived which governs the lifetime of the air pockets and which can be used to predict the longevity of underwater superhydrophobicity.

Viscous optical clearing agent for in vivo optical imaging

By allowing more photons to reach deeper tissue, the optical clearing agent (OCA) has gained increasing attention in various optical imaging modalities. However, commonly used OCAs have high fluidity, limiting their applications in in vivo studies with oblique, uneven, or moving surfaces. In this work, we reported an OCA with high viscosity. We measured the properties of this viscous OCA, and tested its successful performances in the imaging of a living animal’s skin with two optical imaging modalities: photoacoustic microscopy and optical coherence tomography. Our results demonstrated that the viscous OCA has a great potential in the study of different turbid tissues using various optical imaging modalities.

Importance of hierarchical structures in wetting stability on submersed superhydrophobic surfaces

Submersed superhydrophobic surfaces exhibit great potential for reducing flow resistance in microchannels and drag of submersed bodies. However, the low stability of liquid-air interfaces on those surfaces limits the scope of their application, especially under high liquid pressure. In this paper, we first investigate the wetting states on submersed hydrophobic surfaces with one-level structure under hydrostatic pressure. Different equilibrium states based on free-energy minimization are formulated, and their stabilities are analyzed as well. Then, by comparison with the existing numerical and experimental studies, we confirm that a new metastable state, which happens after depinning of the three-phase contact line (TCL), exists. Finally, we show that a strategy of using hierarchical structures can strengthen the TCL pinning of the liquid-air interface in the metastable state. Therefore, the hierarchical structure on submersed surfaces is important to further improve the stability of superhydrophobicity under high liquid pressure.

Graphene mode-locked femtosecond laser at 2 μm wavelength

We experimentally demonstrated a passively mode-locked femtosecond laser by using a graphene-based saturable absorber mirror (graphene SAM) in the spectral region of 2 μm. The graphene SAM was fabricated by transferring chemical-vapor-deposited, high-quality, and large-area graphene on a highly reflective plane mirror. Stable mode-locked laser pulses as short as 729 fs were obtained with a repetition rate of 98.7 MHz and an average output power of 60.2 mW at 2018 nm.

Levels and profiles of unintentionally produced persistent organic pollutants in surface soils from Shanxi province, China

Six species of unintentionally produced persistent organic pollutions comprised of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, polychlorinated biphenyls, polychlorinated naphthalenes, hexachlorobenzene and pentachlorobenzene in soils collected from Shanxi province, China were determined. The sum toxic equivalent ranged from 0.14 to 2.20 with an average of 0.94 pg TEQ/g. Polychlorinated dibenzo-p-dioxins/furans contributed the most toxic proportion to the total toxic equivalent. CB-126 was the most toxic contributor to polychlorinated biphenyls. CN66/67 and CN73 are the dominant toxic congeners to polychlorinated naphthalenes. From the patterns, it was speculated that thermal related industries were possible sources of unintentionally produced persistent organic pollutions.

Effect of salicylate on KCNQ4 of the guinea pig outer hair cell

Salicylate causes a moderate hearing loss and tinnitus in humans at high-dose levels. Salicylate-induced hearing loss has been attributed to impaired sound amplification by outer hair cells (OHCs) through its direct action on the OHC motility sensor and/or motor. However, there is a disparity of salicylate concentrations between the clinical and animal studies, i.e., extremely high extracellular concentrations of salicylate (from 1 to 10 mM) is required to produce a significant reduction of electromotility in animal studies. Such concentrations are above the clinical/physiological range for humans. Here, we showed that clinical/physiological concentration range of salicylate caused concentration-dependent and reversible reductions in I(K,n) (KCNQ4) and subsequent depolarization of OHCs. Salicylate reduced the maximal tail current of the activation curve of I(K,n) without altering the voltage-sensitivity (V(half)). The salicylate-induced reduction of I(K,n) was almost completely blocked by linopirdine (0.1 mM) and BaCl₂ (10 mM). Consistent with the finding in OHCs, salicylate significantly reduced KCNQ4-mediated current expressed in Chinese hamster ovarian (CHO) cells by comparable amplitude to OHCs without significantly shifting V(half). Nonstationary fluctuation analysis shows that salicylate significantly reduced the estimated single-channel current amplitude and numbers. Intracellular Ca²+ elevation resulting from cytoplasmic acidosis also contributes to the current reduction of I(K,n) (KCNQ4) of OHCs. These results indicate a different model for the salicylate-induced hearing loss through the reduction of KCNQ4 and subsequent depolarization of OHCs, which reduces the driving force for transduction current and electromotility. The major mechanism underlying the reduction of I(K,n) (KCNQ4) is the direct blocking action of salicylate on KCNQ4.