Development and external validation of a prediction model for the premature circuit clotting of continuous renal replacement therapy in critically ill patients.

OBJECTIVE: This study aimed to develop and validate a prediction model for premature circuit clotting of continuous renal replacement therapy (CRRT) in critically ill patients. DESIGN: A retrospective cohort study was conducted on ICU patients undergoing CRRT. The Medical Information Mart for Intensive Care-III Clinical Database CareVue subset and Medical Information Mart for Intensive Care-IV were utilized for model development, while the eICU Collaborative Research Database was employed for external validation. Predictive factors were selected through Least Absolute Shrinkage and Selection Operator Regression and univariate logistic regression. A prediction model was then developed using binary logistic regression. Internal and external validations assessed the model's discrimination, calibration, and clinical net benefit. RESULTS: This study encompassed 2531 patients overall, with a premature circuit clotting rate of 31.88 %. The prediction model comprises five variables: body temperature, anticoagulation, mean arterial pressure, maximum transmembrane pressure change within two hours, and vasopressor. The model demonstrated robust predictive performance, achieving an area under the receiver operating characteristic curve of 0.897 (95 % CI: 0.879-0.915) in the training set and 0.877 (95 % CI: 0.852-0.902) in the external validation set. Internal validation yielded a Brier score of 0.087, while external validation showed a Brier score of 0.120. Calibration curves indicated good model calibration for both validations. The decision curve analysis indicates that the model yields a clinical net benefit across a wide range of decision thresholds. CONCLUSION: The model demonstrates robust discrimination, calibration, and clinical net benefit, with readily available variables indicating substantial potential for valuable clinical applications. IMPLICATIONS FOR CLINICAL PRACTICE: Healthcare providers in the ICU can leverage the model to evaluate the risk of premature circuit clotting in critically ill patients undergoing continuous renal replacement therapy, facilitating timely intervention to mitigate its incidence.

Factors influencing the development of nursing professionalism: a descriptive qualitative study.

BACKGROUND: The shortage of nurses threatens the entire healthcare system, and nursing professionalism can improve nurse retention and enhance the quality of care. However, nursing professionalism is dynamic, and the factors influencing its development are not fully understood. METHODS: A qualitative descriptive study was conducted. Using maximum variation and purposive sampling, 14 southern and northern China participants were recruited. Semi-structured interviews were conducted from May 2022 to August 2023 in face-to-face conversations in offices in the workplace or via voice calls. The interviews were transcribed verbatim and analyzed via thematic analysis. RESULTS: Three main themes emerged: (1) nourishment factors: promoting early sprouting; (2) growth factors: the power of self-activation and overcoming challenges; and (3) rootedness factors: stability and upward momentum. Participants described the early acquisition of nursing professionalism as derived from personality traits, family upbringing, and school professional education, promoting the growth of nursing professionalism through self-activation and overcoming challenges, and maintaining the stable and upward development of nursing professionalism through an upward atmosphere and external motivation. CONCLUSION: We revealed the dynamic factors that influence the development of nursing professionalism, including "nourishment factors", "growth factors", and "rootedness factors". Our findings provide a foundation for future development of nursing professionalism cultivation strategies. Nursing administrators can guide the development of nurses' professionalism from many angles according to the stage they are in, and the development of professionalism deserves more attention. In the future, we can no longer consider the development of nursing professionalism solely as the responsibility of individual nurses; the power of families, organizations, and society is indispensable to jointly promoting nursing professionalism among nurses.

IL-13 alleviates acute kidney injury and promotes regeneration via activating the JAK-STAT signaling pathway in a rat kidney transplantation model.

AIMS: To identify whether and how a younger systemic internal milieu alleviates acute kidney injury (AKI) in grafts after kidney transplantation. MATERIALS AND METHODS: We conducted an allogenic heterotopic rat kidney transplantation model with young and adult recipients receiving similar donor kidneys. We evaluated the renal function, histological damage, apoptosis, dedifferentiation, proliferation, hub regulating cytokines, and signaling pathways involved in young and adult recipients based on transcriptomics, proteomics, and experimental validation. We also validated the protective effect and mechanism of interleukin-13 (IL-13) on tubular epithelial cell injury induced by transplantation in vivo and by cisplatin in vitro. KEY FINDINGS: Compared with adult recipients, the young recipients had lower levels of renal histological damage and apoptosis, while had higher levels of dedifferentiation and proliferation. Serum IL-13 levels were higher in young recipients both before and after surgery. Pretreating with IL-13 decreased apoptosis and promoted regeneration in injured rat tubular epithelial cells induced by cisplatin, while this effect can be counteracted by a JAK2 and STAT3 specific inhibitor, AG490. Recipients pretreated with IL-13 also had lower levels of histological damage and improved renal function. SIGNIFICANCE: Higher levels of IL-13 in young recipients ameliorates tubular epithelial cell apoptosis and promotes regeneration via activating the JAK-STAT signaling pathway both in vivo and in vitro. Our results suggest that IL-13 is a promising therapeutic strategy for alleviating AKI. The therapeutic potential of IL-13 in injury repair and immune regulation deserves further evaluation and clinical consideration.

A One Step Strategy Based on Hollow Gold Nanoparticles to Detect C-Reactive Protein with High Sensitivity (Hs-CRP) in Serum for Monitoring Cardiovascular Disease.

Purpose: Rapid detection and diagnosis of diseases facilitate timely and effective treatment of cardiovascular diseases (CVD). The establishment of a one-step rapid detection method provides a new method for the initial screening and disease risk assessment of patients with cardiovascular diseases in primary medical units. Methods: Hollow gold nanoparticles (HGNPs) were synthesized using a cobalt template method followed by use as signal amplification probes for ultra-sensitive quantitative detection of serum C-reactive protein (CRP). To induce the localized surface plasmon resonance (LSPR) and improve protein labeling efficiency, we developed a sensitive detection mode by coating polyvinylpyrrolidone (PVP-K30) on the HGNPs, resulting in a significant improvement in detection performance. Results: Compared to traditional colloidal GNP-based LFTA, PVP-coated HGNPs exhibit a lower visual detection limit of 1 ng/mL, which a 25-fold decrement compare to using GNPs as the antibody-labeled probe, and the detection limit could be reduced to 0.14 ng/mL under the quantitative instrument. Conclusion: The one-step method based on HGNP immunochromatographic strips modified with PVP established in this study can be used for the detection of CRP and hs-CRP in biological samples. The performance of the immunochromatographic technique designed in this study was evaluated from the perspective of synthetic markers, and the application conditions of this strip were screened, verifying its high specificity, indicating that it has high sensitivity and strong detection limit compared to colloidal gold. The sensitivity of the hollow gold immunochromatographic test strip in this article has been increased by about 25 times, providing a new method for rapid detection of CVD in clinical diagnosis.

Vicarious trauma in nursing: A hybrid concept analysis.

BACKGROUND: Vicarious trauma can significantly affect the physical and mental health of nurses, as well as their ability to provide quality of care. However, the concept of vicarious trauma has received limited attention and remains controversial in the nursing context. OBJECTIVE: The purpose of this study was to clarify and define the concept of vicarious trauma as it pertains to the nursing context. METHODS: The Schwartz and Kim's three-stage hybrid concept analysis method was used to define the concept. In the theoretical phase, PubMed, CINAHL, OVID, Medline, Embase, Web of Science, Scopus, ProQuest, PsycINFO, CNKI database, VIP database and Wanfang database were used using keywords "nurs*"and "vicarious trauma*", resulting in a total of 25 papers. In the fieldwork phase, we conducted participatory observations in three hospitals and semi-structured in-depth interviews with 18 clinical nurses from seven cities. In the analysis phase, the results of the previous two phases were integrated to develop a comprehensive concept of vicarious trauma in nursing. RESULTS: Based on the results of the theoretical and field phases, we propose the concept of vicarious trauma in nursing as follows: vicarious trauma is a psychological trauma impacting nurses' cognitive schema which they may experience in clinical settings or on social media, resulting from deeply empathize with the physical or emotional trauma of patients, family, or colleagues, such as patients' physical injuries or death, family's grieving feelings and colleagues' received threats and attacks. Positively, vicarious trauma can transform into vicarious post-trauma growth through repositioning and connection, nourishing nurses and promoting their personal and professional development. CONCLUSION: The concept of vicarious trauma in nursing is multidimensional and holistic. This study clarifies the concept of vicarious trauma in nursing using the hybrid concept analysis, providing a framework for future research and practice on vicarious trauma in the nursing field. PATIENT OR PUBLIC CONTRIBUTION: Nurses contributed to the conduct of the study by participating in the data collection via interviews.

Sensitization Strategies of Lateral Flow Immunochromatography for Gold Modified Nanomaterials in Biosensor Development.

Gold nanomaterials have become very attractive nanomaterials for biomedical research due to their unique physical and chemical properties, including size dependent optical, magnetic and catalytic properties, surface plasmon resonance (SPR), biological affinity and structural suitability. The performance of biosensing and biodiagnosis can be significantly improved in sensitivity, specificity, speed, contrast, resolution and so on by utilizing multiple optical properties of different gold nanostructures. Lateral flow immunochromatographic assay (LFIA) based on gold nanoparticles (GNPs) has the advantages of simple, fast operation, stable technology, and low cost, making it one of the most widely used in vitro diagnostics (IVDs). However, the traditional colloidal gold (CG)-based LFIA can only achieve qualitative or semi-quantitative detection, and its low detection sensitivity cannot meet the current detection needs. Due to the strong dependence of the optical properties of gold nanomaterials on their shape and surface properties, gold-based nanomaterial modification has brought new possibilities to the IVDs: people have attempted to change the morphology and size of gold nanomaterials themselves or hybrid with other elements for application in LFIA. In this paper, many well-designed plasmonic gold nanostructures for further improving the sensitivity and signal output stability of LFIA have been summarized. In addition, some opportunities and challenges that gold-based LFIA may encounter at present or in the future are also mentioned in this paper. In summary, this paper will demonstrate some feasible strategies for the manufacture of potential gold-based nanobiosensors of post of care testing (POCT) for faster detection and more accurate disease diagnosis.

Nanoengineered mesenchymal stem cell therapy for pulmonary fibrosis in young and aged mice.

Pulmonary fibrosis (PF) is an age-related interstitial lung disease that results in notable morbidity and mortality. The Food and Drug Administration-approved drugs can decelerate the progression of PF; however, curing aged patients with severe fibrosis is ineffective because of insufficient accumulation of these drugs and wide necrocytosis of type II alveolar epithelial cells (AEC IIs). Here, we constructed a mesenchymal stem cell (MSC)-based nanoengineered platform via the bioconjugation of MSCs and type I collagenase-modified liposomes loaded with nintedanib (MSCs-Lip@NCAF) for treating severe fibrosis. Specifically, MSCs-Lip@NCAF migrated to fibrotic lungs because of the homing characteristic of MSCs and then Lip@NCAF was sensitively released. Subsequently, Lip@NCAF ablated collagen fibers, delivered nintedanib into fibroblasts, and inhibited fibroblast overactivation. MSCs differentiated into AEC IIs to repair alveolar structure and ultimately promote the regeneration of damaged lungs in aged mice. Our findings indicated that MSCs-Lip@NCAF could be used as a promising therapeutic candidate for PF therapy, especially in aged patients.

Size-Dependent Reactivity of Con- (n = 5-25) Cluster Anions toward Carbon Dioxide.

A fundamental understanding of the reactivity evolution of nanosized clusters at an atomically precise level is pivotal to assemble desired materials with promising candidates. Benefiting from the tandem mass spectrometer coupled with a high-temperature ion-trap reactor, the reactions of mass-selected Con- (n = 5-25) clusters with CO2 were investigated and the increased reactivity of Co20-25- was newly discovered herein. This finding marks an important step to understand property evolution of subnanometer metal clusters (Co25-, ∼0.8 nm) atom-by-atom. The reasons behind the increased reactivity of Co20-25- were proposed by analyzing the reactions of smaller Co6-8- clusters that exhibit significantly different reactivity toward CO2, in which a lower electron affinity of Con contributes to the capture of CO2 while the flexibility of Con- could play vital roles to stabilize reaction intermediates and suppress the barriers of O-CO rupture and CO desorption.

Filtration of the preferred catalyst for reverse water-gas shift among Rhn- (n = 3-11) clusters by mass spectrometry under variable temperatures.

The key to optimizing energy-consuming catalytic conversions lies in acquiring a fundamental understanding of the nature of the active sites and the mechanisms of elementary steps at an atomically precise level, while it is challenging to capture the crucial step that determines the overall temperature of a real-life catalytic reaction. Herein, benefiting from a newly-developed high-temperature ion trap reactor, the reverse water-gas shift (CO2 + H2 → CO + H2O) reaction catalyzed by the Rhn- (n = 3-11) clusters was investigated under variable temperatures (298-783 K) and the critical temperature that each elementary step (Rhn- + CO2 and RhnO- + H2) requires to take place was identified. The Rh4- cluster strikingly surpasses other Rhn- clusters to drive the catalysis at a mild starting temperature (∼440 K). This finding represents the first example that a specifically sized cluster catalyst that works under an optimum condition can be accurately filtered by using state-of-the-art mass spectrometric experiments and rationalized by quantum-chemical calculations.

Effectiveness of non-pharmacological interventions for sleep disturbances in people living with dementia: A systematic review and meta-analysis.

We summarize the evidence on non-pharmacological interventions for sleep disturbances in people living with dementia(PlwD). A literature search was performed using PubMed, Embase, Cochrane library, Web of Science, PsycINFO, CINAHL, and clinicaltrials.gov. Up to August 20, 2022. Six studies met our eligibility criteria. Light therapy, the therapeutic pet-type robotic seal(PRAO), and slow-stroke back massage(SSBM) are non-pharmacological interventions for sleep disturbances in PlwD.PARO increased night-time sleep duration (p < 0.05). The benefit of SSBM for sleep disturbances in PlwD is unclear (p > 0.05). Although there is a lack of evidence for the effect of light therapy on sleep disturbances in PlwD (p > 0.05), light therapy reduced sleep disturbance (SMD = -0.38; 95% CI:1.25, 0.48), increased sleep efficiency (MD = 3.77; 95% CI:-0.23, 7.78), and also reduced depression (MD = -2.49; 95% CI: -2.92, -2.06). More large-scale randomized controlled trials are needed and consider combining multiple non-pharmacological measures for sleep interventions in PlwD.

What is nursing professionalism? a concept analysis.

BACKGROUND: Nursing professionalism plays an important role in clinical nursing. However, a clear conceptual understanding of nursing professionalism is lacking. METHOD: Walker and Avant's strategy was used to analyse the concept of nursing professionalism. We searched electronic databases, including PubMed, Scopus, and CINAHL, for studies published from 1965 to 2021. Quantitative or qualitative studies published in English that focused on nursing professionalism were included in the study. RESULTS: The three attributes of nursing professionalism are multidimensional, dynamic, and culture oriented. Based on the analysis, nursing professionalism is defined as providing individuals care based on the principles of professionalism, caring, and altruism. CONCLUSIONS: This study offers a theoretical definition and conceptual model of nursing professionalism that may be applied to develop standardized assessment tools or nursing professionalism training programs.

A Compartmentalized Nanoreactor Formed by Interfacial Hydrogelation for Cascade Enzyme Catalytic Therapy.

Some cellular enzymatic pathways are located within a single organelle, while most others involve enzymes that are located within multiple compartmentalized cellular organelles to realize the efficient multi-step enzymatic process. Herein, bioinspired by enzyme-mediated biosynthesis and biochemical defense, a compartmented nanoreactor (Burr-NCs@GlSOD ) was constructed through a self-confined catalysis strategy with burr defect-engineered molybdenum disulfide/Prussian blue analogues (MoS2 /PBA) and an interfacial diffusion-controlled hydrogel network. The specific catalytic mechanism of the laccase-like superactivity induced hydrogelation and cascade enzyme catalytic therapy were explored. The confined hydrogelation strategy introduces a versatile means for nanointerface functionalization and provides insight into biological construction of simulated enzymes with comparable activity and also the specificity to natural enzymes.

Pathological collagen targeting and penetrating liposomes for idiopathic pulmonary fibrosis therapy.

Idiopathic pulmonary fibrosis (IPF) is a fibrotic interstitial lung disease in which collagen progressively deposits in the supporting framework of the lungs. The pathological collagen creates a recalcitrant barrier in mesenchyme for drug penetration, thus greatly restricting the therapeutical efficacy. On the other hand, this overloaded collagen is gradually exposed to the bloodstream at fibrotic sites because of the vascular hyperpermeability, thus serving as a potential target. Herein, pathological collagen targeting and penetrating liposomes (DP-CC) were constructed to deliver anti-fibrotic dual drugs including pirfenidone (PFD) and dexamethasone (DEX) deep into injured alveoli. The liposomes were co-decorated with collagen binding peptide (CBP) and collagenase (COL). CBP could help vehicle recognize the pathological collagen and target the fibrotic lungs efficiently because of its high affinity to collagen, and COL assisted in breaking through the collagen barrier and delivering vehicle to the center of injured sites. Then, the released dual drugs developed a synergistic anti-fibrotic effect to repair the damaged epithelium and remodel the extracellular matrix (ECM), thus rebuilding the lung architecture. This study provides a promising strategy to deliver drugs deep into pathological collagen accumulated sites for the enhanced treatment of IPF.

Multiple CO2 reduction mediated by heteronuclear metal carbide cluster anions RhTaC2.

Noble metals dispersed on transition-metal carbides exhibit extraordinary activity in CO2 catalytic conversion and bimetallic carbides generated at the interface were proposed to contribute to the observed activity. Heteronuclear metal carbide clusters (HMCCs) that compositionally resemble the bimetallic carbides are suitable models to get a fundamental understanding of the reactivity of the related condensed-phase catalysts, while the reaction of HMCCs with CO2 has not been touched in the gas phase. Herein, benefiting from the newly designed double ion trap reactors, the reaction of laser-ablation generated and mass-selected RhTaC2- clusters with CO2 was studied. The experimental results identified that RhTaC2- can reduce four CO2 molecules consecutively and generate the product RhTaC2O4-. The pivotal roles of Rh-Ta synergy and the C2 ligand in driving CO2 reduction were rationalized by theoretical calculations. The presence of an attached CO unit on the product RhTaC2O4- was evidenced by the collision-induced dissociation experiment, providing a fundamental strategy to alleviate carbon deposition under a CO2 atmosphere at elevated temperatures.

Cefquinome Sulfate Oily Nanosuspension Designed for Improving its Bioavailability in the Treatment of Veterinary Infections.

Introduction: Cefquinome sulfate (CS) is the first fourth-generation antibiotic for animals, which has a wide antibacterial spectrum, strong antibacterial activity and low drug resistance. However, it is accompanied by problems of poor therapeutic efficacy. In this context, the use of nanosuspensions have been found to be an attractive strategy. The main objective of this work is to develop a new oily nanosuspension to improve bioavailability and stability of CS formulations. Methods: After screening the formulations, cefquinome sulfate oily nanosuspension (CS-NSP) was prepared by mortar grinding, using propylene glycol dicaprolate/dicaprate (Labrafac™ PG) as oil medium and caprylocaproyl polyoxyl-8 glycerides (Labrasol®) as stabilizer. The properties of CS-NSP were investigated by testing its physicochemical characteristics, stability, in vitro release, hemolysis, and muscle irritation. The in vivo pharmacokinetics of CS-NSP was studied using rats. Results: Results show that CS-NSP presents suitable stability, physicochemical properties and safety. Moreover, a rapid release and high bioavailability of CS-NSP have also been verified in the study. Pharmacokinetic experiments in vivo showed that the bioavailability of CS-NSP was about 1.6 times that of commercial cefquinome sulfate injection (CS-INJ, Chuangdao®) (p<0.01). These advantages of CS-NSP were carried out by small particle size and low viscosity, being associated with the use of Labrafac PG and stabilizer Labrasol. Conclusion: The results proved that the new preparation is safe and effective and is expected to become a promising veterinary nanodelivery system.

Transurethral Retrograde Fishing the Double J Urethral Stent: A Tertiary Children Hospital's Experience With a New Technical Strategy.

Purpose: The purpose of this study is to provide a new strategy for non-cystoscopic double J urethral stent (JJS) removal, the transurethral retrograde fishing the double J urethral stent (TURFJJS), that avoids general anesthesia in pediatric populations. Methods: We retrospectively reviewed the JJS removal records of patients having ureteropelvic junction obstruction (UPJO). We analyzed differences in the removal success rates, operation-related severe complications, total cost, duration, and parental satisfaction between TURFJJS and traditional cystoscopic double J urethral stent removal (CJJSR) procedures. Results: A total of 324 patients with UPJO were included in this study. CJJSR yielded a success rate of 100%. TURFJJS achieved a success rate of 94.3%. The TURFJJS was just an outpatient procedure, and its total cost was about 800 Chinese yuan (US$ 124). There were no severe JJS removal-related complications using TURFJJS. Parental satisfaction was 98.2 and 92.5% for the CJJSR and TURFJJS protocols, respectively. Conclusion: TURFJJS is safe, effective, cost-effective, and well-tolerated in pediatric patients, minimizing or eliminating the need for general anesthesia, additional hospitalization, and waste of time. TURFJJS should be widely used in pediatric urology.

Chinese nurses' self-expression media image during COVID-19 pandemic: A qualitative media image analysis.

AIM: To explore and describe nurses' self-expression media image during COVID-19 pandemic in China. BACKGROUND: Nurses play an important role in COVID-19 pandemic. Although nurses were widely reported by the media, which included praise for nurses and nursing work, the researches on how nurses expressed their self-images were limited. DESIGN: Qualitative media analysis. METHODS: Qualitative media analysis was conducted from January to April 2020, the researchers collected images and texts of 16 Chinese nurses who take care of COVID-19 patients. These images and texts were published on WeChat Moments by themselves. After analysed each image and text, researchers identified the denotative and connotative elements in each image and summarized each image in narrative way. FINDINGS: This study analysed 219 pictures and 15 short videos of 16 nurses' self-expression in WeChat moments. In this study, the media image self-expression of nurses were mostly positive. The images expressed by nurses in this study included care image; hero image; soldier image; female image; hope image and team image. Nurses rarely showed negative images in the media; The negative nurses image were expressed in hidden way, which included exhausted nurses image and fragile nurses image. Moreover, the nurse self-expression media image emphasized the nursing professionalism, but less showed the nursing connotation. CONCLUSIONS: The positive media image self-expression of nurses should be encouraged. Nurse Managers should pay attention to the deficiency of nursing image expression and guide nurses to show the essence and connotation of nursing.

Acetazolamide Alleviate Cerebral Edema Induced by Ischemic Stroke Through Inhibiting the Expression of AQP4 mRNA.

OBJECTIVE: We want to investigate the effect of aquaporin-4 (AQP4) on cerebral edema induced by ischemic stroke in rats and explore whether inhibiting the expression of AQP4 through acetazolamide (AZA) could attenuate brain edema and protect cerebral function. METHODS: The Sprague Dawley (SD) rats were randomly divided into four groups: sham + saline group, sham + AZA group, AZA intervention group, and nonintervention group. Each group was divided into five subgroups according to the time of cerebral ischemia (6 h, 1 day, 3 days, 5 days, and 7 days). The model of cerebral infarction in rats was adopted by means of the bilateral carotid arteries ligation (2-VO) method. The rats in intervention group were given intraperitoneal injection of AZA (35 mg/kg/day). Hematoxylin-eosin staining was performed for pathological analysis of the infarcted area. The brain water content was calculated to evaluate the degree of brain edema. The messenger RNA (mRNA) and protein expressions of AQP4 in the brain were measured by quantitative real-time polymerase chain reaction and immunohistochemistry, respectively. RESULTS: Significant cerebral pathological damages were found in ischemic stroke rats. The brain water content, protein, and mRNA expression of AQP4 of the intervention and nonintervention groups were markedly higher than those of the sham groups. By contrast, AZA administration reduced the brain water content, whereas improved cerebral dysfunction was induced by ischemic stroke. Moreover, AZA obviously reduced the protein and mRNA expression of AQP4 after ischemic stroke in rats' brains. CONCLUSIONS: The expression of AQP4 was closely related to cerebral edema induced by ischemic stroke. Decreasing the expression of AQP4 mRNA by AZA administration can effectively relieve cerebral edema and decrease cerebral pathological damage.

Research on Frequency Doubling Effect of Thermoacoustic Speaker Based on Graphene Film.

In this work, the frequency doubling effect of thermoacoustic speakers is studied, and a method is analyzed to suppress the frequency doubling effect. Three cases were analyzed by superimposing the DC bias on the AC excitation: (1) DC is less than AC; (2) DC is equal to AC; (3) DC is greater than AC. We found that the frequency doubling effect can be well suppressed by superimposing a larger DC excitation on the AC excitation. The laser scribing technology was used to prepare graphene film in only one step, and the screen printing technology was used to prepare conductive electrodes. The microphone and B&K system was used to record the sound pressure level and study the suppression of frequency doubling effect. Finally, the sound pressure levels with the three different kinds of excitations were measured. The measured results show that they have a good agreement with the theoretical results. The suppression effect will be better when DC amplitude is greater than AC amplitude. Therefore, this work has certain reference significance for the further study and application of thermoacoustic speakers.