RESUMEN
ABSTRACT: Myoepithelial carcinomas of soft tissue are rare, and most are malignant. The optimal treatment is surgical excision. The arches of the foot are a composite structure responsible for weight bearing and pressure distribution, so it is a vast challenge in reconstruction. We report a case of reconstruction of the midfoot with a free fibular bone flap and tendon graft. We review the literature to compare various options in foot reconstructions and sort out the outcomes of different bone flaps. The free fibula osteocutaneous flap is the superior choice for midfoot reconstruction owing to its sufficient length, strength, flexible skin paddles, easy-to-withstand osteotomy, and simultaneous tendon graft harvesting.
Asunto(s)
Peroné , Colgajos Tisulares Libres , Procedimientos de Cirugía Plástica , Humanos , Peroné/trasplante , Procedimientos de Cirugía Plástica/métodos , Colgajos Tisulares Libres/trasplante , Mioepitelioma/cirugía , Neoplasias de los Tejidos Blandos/cirugía , Masculino , Femenino , Persona de Mediana EdadRESUMEN
This study was to translate the Pieper-Zulkowski pressure ulcer knowledge test (PZ-PUKT) into Traditional Chinese and evaluate its psychometric properties as well as identify the predictors of knowledge on pressure injury. The PZ-PUKT was translated into Traditional Chinese (TC-PZ-PUKT), and its content validity was evaluated. A total of 296 nurses participated in this study and completed the 72-item TC-PZ-PUKT online. The reliability of the TC-PZ-PUKT was analysed by evaluating its internal consistency and test-retest reliability. Hierarchical regression was used to determine factors associated with TC-PZ-PUKT scores. Content validity was achieved with a score of 0.986. Internal consistency was observed to be reliable, with a Cronbach's alpha of 0.858. The mean knowledge score on the TC-PZ-PUKT was 72.5%, with a 1-week test-retest reliability of r = 0.849. Education level, certification as a wound specialist and self-learning through reading articles, books or guidelines on pressure injury were significantly associated with TC-PZ-PUKT scores. The TC-PZ-PUKT is a valid and reliable tool. Education level, certification as a wound specialist and self-learning regarding pressure injury are related to knowledge of pressure injury.
Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Úlcera por Presión , Psicometría , Humanos , Úlcera por Presión/diagnóstico , Psicometría/métodos , Psicometría/instrumentación , Reproducibilidad de los Resultados , Femenino , Masculino , Adulto , Encuestas y Cuestionarios , China , Persona de Mediana Edad , Competencia Clínica/estadística & datos numéricos , Traducciones , Pueblos del Este de AsiaRESUMEN
Syndecan-3 (SDC3) and Syndecan-4 (SDC4) are distributed throughout the nervous system (NS) and are favourable factors in motor neuron development. They are also essential for regulation of neurite outgrowth in the CNS. However, their roles in the reconstruction of the nodes of Ranvier after peripheral nerve injury (PNI) are still unclear. Present study used an in vivo model of end-to-side neurorrhaphy (ESN) for 1-3 months. The recovery of neuromuscular function was evaluated by grooming test. Expression and co-localization of SDC3, SDC4, and Nav1.6 channel (Nav1.6) at regenerating axons were detected by proximity ligation assay and confocal microscopy after ESN. Time-of-flight secondary ion mass spectrometry was used for imaging ions distribution on tissue. Our data showed that the re-clustering of sodium and Nav1.6 at nodal regions of the regenerating nerve corresponded to the distribution of SDC3 after ESN. Furthermore, the re-establishment of sodium and Nav1.6 correlated with the recovery of muscle power 3 months after ESN. This study suggested syndecans may involve in stabilizing Nav1.6 and further modulate the distribution of sodium at nodal regions after remyelination. The efficiency of sodium re-clustering was improved by the assistance of anionic syndecan, resulting in a better functional repair of PNI.
Asunto(s)
Canal de Sodio Activado por Voltaje NAV1.6/metabolismo , Procedimientos Neuroquirúrgicos , Nódulos de Ranvier/metabolismo , Sodio/metabolismo , Sindecano-3/metabolismo , Animales , Masculino , Canal de Sodio Activado por Voltaje NAV1.6/análisis , Canal de Sodio Activado por Voltaje NAV1.6/genética , Regeneración Nerviosa , Ratas , Ratas Wistar , Sodio/análisis , Sindecano-3/análisis , Sindecano-3/genéticaRESUMEN
This paper aims to develop a multisensor data fusion technology-based smart home system by integrating wearable intelligent technology, artificial intelligence, and sensor fusion technology. We have developed the following three systems to create an intelligent smart home environment: (1) a wearable motion sensing device to be placed on residents' wrists and its corresponding 3D gesture recognition algorithm to implement a convenient automated household appliance control system; (2) a wearable motion sensing device mounted on a resident's feet and its indoor positioning algorithm to realize an effective indoor pedestrian navigation system for smart energy management; (3) a multisensor circuit module and an intelligent fire detection and alarm algorithm to realize a home safety and fire detection system. In addition, an intelligent monitoring interface is developed to provide in real-time information about the smart home system, such as environmental temperatures, CO concentrations, communicative environmental alarms, household appliance status, human motion signals, and the results of gesture recognition and indoor positioning. Furthermore, an experimental testbed for validating the effectiveness and feasibility of the smart home system was built and verified experimentally. The results showed that the 3D gesture recognition algorithm could achieve recognition rates for automated household appliance control of 92.0%, 94.8%, 95.3%, and 87.7% by the 2-fold cross-validation, 5-fold cross-validation, 10-fold cross-validation, and leave-one-subject-out cross-validation strategies. For indoor positioning and smart energy management, the distance accuracy and positioning accuracy were around 0.22% and 3.36% of the total traveled distance in the indoor environment. For home safety and fire detection, the classification rate achieved 98.81% accuracy for determining the conditions of the indoor living environment.
Asunto(s)
Inteligencia Artificial , Algoritmos , Gestos , Tecnología InalámbricaRESUMEN
This study characterized diurnal variations in the compositions of total suspended particulates (TSP) and dry deposits of particulates from ambient air, and the metallic elements that are contained in them at harbor, airport and farmland (HAF) sampling sites from August, 2013 to July, 2014. Two-way ANOVA of the amounts of metallic elements in the TSP and dry deposits was carried out in all four seasons at the HAF sampling sites. The metallic elements Cr and Cu originated in local emission sources at the airport. Metallic elements Zn and Pb originated in local emission sources at the harbor. Finally, metallic element Cd originated in local emissions form farmland. The following results were also obtained. (1) The metallic composition of the TSP differed significantly from that of the dry deposits in all four seasons at the harbor and farmland sampling sites, but not at the airport sampling site. (2) High correlations coefficients were found between the amounts of metallic elements Cr and Cu in the TSP and those in the dry deposits at the airport sampling site. (3) Pb was present in the TSP and the dry deposits at the harbor sampling site.
Asunto(s)
Contaminantes Atmosféricos/análisis , Aire/análisis , Monitoreo del Ambiente , Granjas , Metales Pesados/análisis , Estaciones del Año , Estaciones de Transporte , Aeropuertos , Cadmio/análisis , Cromo/análisis , Cobre/análisis , Plomo/análisis , Periodicidad , Navíos , Taiwán , Zinc/análisisRESUMEN
The purpose of this study is to characterize metallic elements associated with atmospheric particulate matter in the dry deposition plate, total suspended particulate, fine particles, and coarse particles at Taichung Harbor and Gong Ming Junior High School (airport) in central Taiwan at a sampling site from June 2013 to August 2013. The results indicated that: (1) the average concentrations of the metallic elements Cr and Cd were highest at the Gong Ming Junior High School (airport), and the average concentrations of the metallic elements Ni, Cu, and Pb were highest at the Taichung Harbor sampling site. (2) The high smelting industry density and export/import rate of heavily loaded cargos were the main reasons leading to these findings. (3) The average metallic element dry deposition and metallic element PM(2.5-10) all followed the order of Pb > Cr > Cu > Ni > Cd at the two sampling sites. However, the average metallic elements Cu and Pb were found to have the highest dry deposition velocities and concentrations in PM(2.5) for the two sampling sites in this study. (4) The correlation coefficients of ambient air particle dry deposition and concentration with wind speed at the airport were higher than those from the harbor sampling site. The wind and broad open spaces at Taichung Airport were the possible reasons for the increasing correlation coefficients for ambient air particle concentration and dry deposition with wind speed at the Taichung Airport sampling site.
Asunto(s)
Metales Pesados/análisis , Material Particulado/análisis , Contaminación del Aire/análisis , Monitoreo del Ambiente , Metalurgia , Tamaño de la Partícula , Estaciones del Año , Taiwán , VientoRESUMEN
This study characterized and discussed particulate ambient air particulate concentrations and seasonal variations for PM18, PM10, PM2.5, and PM1 during June 2013-July 2013 at this traffic sampling site. In addition, this study also characterized the ambient air particulates size distributions by using MOUDI-100S4 sampler to collect 1-day the ambient suspended particles (PM18, PM10, PM2.5, and PM1) at this sampling site. In addition, the study also showed that the main pollutants contributions were from traffic and residual areas. As for the pollutants seasonal concentrations variations, the results indicated that the average particle concentrations orders were all displayed as daytime > nighttime for PM18, PM10, PM2.5 and PM1 at this characteristic sampling site. The results further indicated that the mean highest of metal concentrations in this study indicated that the average metal concentration were all displayed as Mn > Cr > Ni > Pb > Cd for PM18, PM10, PM2.5 and PM1 on daytime and nighttime at this characteristic sampling site.
Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Metales/análisis , Material Particulado/análisis , Automóviles/estadística & datos numéricos , Sustancias Peligrosas/análisis , Tamaño de la Partícula , Estaciones del AñoRESUMEN
BACKGROUND: Low-value care (LVC) is a critical issue in terms of patient safety and fiscal policy; however, little has been known in Asia. For the purpose of better understanding the extent of LVC on a national level, the utilization, costs, and associated characteristics of selected international recommendations were assessed in this study. METHODS: This retrospective cohort study used the National Health Insurance (NHI) claims data during 2013-2017 to evaluate the LVC utilization. Adult beneficiaries who enrolled in the NHI program and received at least one of the low-value services in hospitals were included. We measured seven procedures derived from the international recommendations at the hospital level, and a composite measure was created by summing the total utilization of selected services to determine the overall prevalence and corresponding cost. The generalized estimating equation (GEE) model was adopted to estimate the association. RESULTS: A total of 1 970 496 episodes of LVC was identified among 1 218 146 beneficiary-year observations and 2054 hospital-year observations. Overall, the utilization rate of the composite measure increased from 150.70 to 186.23 episodes per 10 000 beneficiaries with the growth in cost from US$ 5.40 to US$ 6.90 million. LVC utilization was proportional to the volume of outpatient visits and length of stay. Also, hospitals with a large volume of outpatient visits (adjusted odds ratio [aOR]: 95% CI, 2.10: 1.26 to 3.49 for Q2-Q3, 2.88: 1.45 to 5.75 for ≥Q3) and a higher proportion of older patients (aOR: 95% CI, 1.06: 1.02 to 1.11) were more likely to have high costs. CONCLUSION: The utilization and corresponding cost of LVC appeared to increase annually despite the relatively lower prevalence compared to other countries. Multicomponent interventions such as recommendations, de-implementation policies and payment reforms are considered effective ways to reduce LVC. Repeated measurements would be needed to evaluate the effectiveness of interventions.
Asunto(s)
Hospitales , Humanos , Estudios Retrospectivos , Femenino , Masculino , Persona de Mediana Edad , Adulto , Hospitales/estadística & datos numéricos , Anciano , Programas Nacionales de Salud/estadística & datos numéricos , Programas Nacionales de Salud/economíaRESUMEN
Objectives: This study compared transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) in terms of short- and long-term effectiveness. Methods: This retrospective cohort study based on nationwide National Health Insurance claims data and Cause of Death data focused on adult patients (n = 3,643) who received SAVR (79%) or TAVR (21%) between 2015 and 2019. Propensity score overlap weighting was applied to account for selection bias. Primary outcomes included all-cause mortality (ACM), hospitalization for heart failure, and a composite endpoint of major adverse cardiac events (MACE). Secondary outcomes included medical utilization, hospital stay, and total medical costs at index admission for the procedure and in various post-procedure periods. The Cox proportional-hazard model with competing risk was used to investigate survival and incidental health outcomes. Generalized estimation equation (GEE) models were used to estimate differences in the utilization of medical resources and overall costs. Results: After weighting, the mean age of the patients was 77.98 ± 5.86 years in the TAVR group and 77.98 ± 2.55 years in the SAVR group. More than half of the patients were female (53.94%). The incidence of negative outcomes was lower in the TAVR group than in the SAVR group, including 1-year ACM (11.39 vs. 17.98%) and 3-year ACM (15.77 vs. 23.85%). The risk of ACM was lower in the TAVR group (HR [95% CI]: 0.61 [0.44-0.84]; P = 0.002) as was the risk of CV death (HR [95% CI]: 0.47 [0.30-0.74]; P = 0.001) or MACE (HR [95% CI]: 0.66 [0.46-0.96]; P = 0.0274). Total medical costs were significantly higher in the TAVR group than in the SAVR in the first year after the procedure ($1,271.89 ± 4,048.36 vs. $887.20 ± 978.51; P = 0.0266); however, costs were similar in the second and third years after the procedure. The cumulative total medical costs after the procedure were significantly higher in the TAVR group than in the SAVR group (adjusted difference: $420.49 ± 176.48; P = 0.0172). Conclusion: In this real-world cohort of patients with aortic stenosis, TAVR proved superior to SAVR in terms of clinical outcomes and survival with comparable medical utilization after the procedure.
RESUMEN
BACKGROUND AND OBJECTIVE: Many studies regarding health analysis request structured datasets but the legacy resources provide scattered data. This study aims to establish a health informatics transformation model (HITM) based upon intelligent cloud computing with the self-developed analytics modules by open source technique. The model was exemplified by the open data of type 2 diabetes mellitus (DM2) with related cardiovascular diseases. METHODS: The Apache-SPARK framework was employed to generate the infrastructure of the HITM, which enables the machine learning (ML) algorithms including random forest, multi-layer perceptron classifier, support vector machine, and naïve Bayes classifier as well as the regression analysis for intelligent cloud computing. The modeling applied the MIMIC-III open database as an example to design the health informatics data warehouse, which embeds the PL/SQL-based modules to extract the analytical data for the training processes. A coupling analysis flow can drive the ML modules to train the sample data and validate the results. RESULTS: The four modes of cloud computation were compared to evaluate the feasibility of the cloud platform in accordance with its system performance for more than 11,500 datasets. Then, the modeling adaptability was validated by simulating the featured datasets of obesity and cardiovascular-related diseases for patients with DM2 and its complications. The results showed that the run-time efficiency of the platform performed in around one minute and the prediction accuracy of the featured datasets reached 90%. CONCLUSIONS: This study helped contribute the modeling for efficient transformation of health informatics. The HITM can be customized for the actual clinical database, which provides big data for training, with the proper ML modules for a predictable process in the cloud platform. The feedback of intelligent computing can be referred to risk assessment in health promotion.
Asunto(s)
Inteligencia Artificial , Enfermedades Cardiovasculares , Nube Computacional , Diabetes Mellitus Tipo 2 , Informática Médica/organización & administración , Algoritmos , Humanos , Aprendizaje AutomáticoRESUMEN
With a high-temperature, high-pressure hydrothermal technique, a new barium lead borate, [Ba3Pb(H2O)][B11O19(OH)3] (1), has been synthesized and characterized by single-crystal X-ray diffraction, and infrared and solid-state NMR spectroscopy. The structure of 1 contains planar thick layers of borates with the Ba2+ cations at sites in the inter- and intralayer space. Each layer consists of three single sheets. The central sheet is very corrugated and is built up from the fundamental building block (FBB) 2Δ3â¡:Δ2â¡-Δ2â¡. On both sides of the central sheet there are borate single chains formed of the very rare FBB 2Δ4â¡:Δ2â¡-3â¡Δ via corner-sharing. This FBB was first observed in a high-pressure polymorph of CaB2O4. These chains are linked into a sheet by PbO5(H2O) polyhedra, which are further linked to the central sheet by sharing vertices between triangles and tetrahedra to form a thick layer. The IR spectrum shows the presence of hydroxyl groups of HBO4, water molecules, BO3 triangles, and BO4 tetrahedra. The presence of BO3 and BO4 polyhedra was also confirmed by 11B MAS NMR spectroscopy.
RESUMEN
The inhibitor of apoptosis proteins (IAPs) play important roles in both apoptosis and innate immunity. Here, we report the first cloning and characterization of a novel IAP family member, PmIAP, from Penaeus monodon. The full-length PmIAP cDNA is 4769bp, with an ORF encoding a protein of 698 amino acids. The PmIAP protein contains three BIR domains and a C-terminal RING domain, and its mRNA was expressed in all analyzed tissues. In insect cells, PmIAP, together with Spodoptera frugiperda IAP, AcMNPV P35, and WSSV449 (or ORF390, an anti-apoptosis protein encoded by white spot syndrome virus), could all block the apoptosis induced by Drosophila Reaper protein (Rpr), whereas only P35 and WSSV449 could block the apoptosis induced by actinomycin D. Co-immunoprecipitation showed that PmIAP physically interacted with Rpr, and in an immunofluorescent analysis the two proteins produced co-localized punctate signals in the cytoplasm. Deletion analysis revealed that both the BIR2 and BIR3 domains of PmIAP could independently bind to and inhibit Rpr, whereas the BIR1 domain could not. These results strongly suggest that PmIAP blocks Rpr's pro-apoptotic activity through mechanisms that are evolutionarily conserved across crustaceans, insects, and mammals.
Asunto(s)
Apoptosis , Proteínas Inhibidoras de la Apoptosis/metabolismo , Penaeidae/química , Secuencia de Aminoácidos , Animales , Línea Celular , Clonación Molecular , ADN Complementario , Dactinomicina/farmacología , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/farmacología , Proteínas Inhibidoras de la Apoptosis/química , Proteínas Inhibidoras de la Apoptosis/genética , Proteínas Inhibidoras de la Apoptosis/farmacología , Datos de Secuencia Molecular , Estructura Terciaria de Proteína , Inhibidores de la Síntesis de la Proteína/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Alineación de SecuenciaRESUMEN
PURPOSE: This study applied open source technology to establish a subject-enabled analytics model that can enhance measurement statistics of case studies with the public health data in cloud computing. METHODS: The infrastructure of the proposed model comprises three domains: 1) the health measurement data warehouse (HMDW) for the case study repository, 2) the self-developed modules of online health risk information statistics (HRIStat) for cloud computing, and 3) the prototype of a Web-based process automation system in statistics (PASIS) for the health risk assessment of case studies with subject-enabled evaluation. The system design employed freeware including Java applications, MySQL, and R packages to drive a health risk expert system (HRES). In the design, the HRIStat modules enforce the typical analytics methods for biomedical statistics, and the PASIS interfaces enable process automation of the HRES for cloud computing. The Web-based model supports both modes, step-by-step analysis and auto-computing process, respectively for preliminary evaluation and real time computation. RESULTS: The proposed model was evaluated by computing prior researches in relation to the epidemiological measurement of diseases that were caused by either heavy metal exposures in the environment or clinical complications in hospital. The simulation validity was approved by the commercial statistics software. The model was installed in a stand-alone computer and in a cloud-server workstation to verify computing performance for a data amount of more than 230K sets. Both setups reached efficiency of about 105 sets per second. CONCLUSIONS: The Web-based PASIS interface can be used for cloud computing, and the HRIStat module can be flexibly expanded with advanced subjects for measurement statistics. The analytics procedure of the HRES prototype is capable of providing assessment criteria prior to estimating the potential risk to public health.
Asunto(s)
Nube Computacional , Enfermedad , Sistemas Especialistas , Internet/estadística & datos numéricos , Modelos Teóricos , Informática en Salud Pública , Programas Informáticos , Anciano , Femenino , Estado de Salud , Humanos , MasculinoRESUMEN
BACKGROUND: Double atrial potentials recorded in the coronary sinus are not an unusual phenomenon in patients with supraventricular tachyarrhythmias. They have been demonstrated to potentiate the occurrence of atrial tachyarrhythmias. METHODS: Two hundred and forty-eight patients were included for investigating the presence of double atrial potentials on the coronary sinus recordings during electrophysiologic study. Group 1 consisted of 136 patients with WPW syndrome and group 2 consisted of 112 patients with atrioventricular nodal reentrant tachycardia (AVNRT). Group 1 patients had a higher incidence of induced atrial fibrillation (AF) (27% vs. 15%, P = 0.045) than group 2 patients. In addition, the incidence of double atrial potentials was significantly higher in group 1 than in group 2 patients (14% vs. 2%, P = 0.001). In group 1, 19 patients with double atrial potentials had a significantly higher incidence of left lateral bypass tracts (79% vs. 39%, P = 0.001) and induced AF (47% vs. 22%, P = 0.01) than 117 patients without double atrial potentials. CONCLUSIONS: WPW syndrome, especially with a left lateral bypass tract, had a higher incidence of double atrial potentials and induced AF than AVNRT. WPW patients with double atrial potentials had a higher incidence of induced AF than those without double atrial potentials. These findings may contribute to understanding the mechanism of induced AF in WPW syndrome.
Asunto(s)
Fibrilación Atrial/fisiopatología , Atrios Cardíacos/fisiopatología , Síndrome de Wolff-Parkinson-White/fisiopatología , Adulto , Fibrilación Atrial/etiología , Fibrilación Atrial/cirugía , Ablación por Catéter , Distribución de Chi-Cuadrado , Técnicas Electrofisiológicas Cardíacas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadísticas no Paramétricas , Taquicardia por Reentrada en el Nodo Atrioventricular/complicaciones , Taquicardia por Reentrada en el Nodo Atrioventricular/fisiopatología , Taquicardia por Reentrada en el Nodo Atrioventricular/cirugía , Síndrome de Wolff-Parkinson-White/complicaciones , Síndrome de Wolff-Parkinson-White/cirugíaRESUMEN
OBJECTIVE: To identify predictors of successful first-line antimuscarinic monotherapy for patients with enlarged prostate and predominant storage symptoms. METHODS: Men aged ≥ 50 years with total International Prostate Symptom Score (IPSS-T) ≥ 8, total prostate volume (TPV) ≥ 20 mL, IPSS quality of life (QOL) index ≥ 2, IPSS voiding to storage (IPSS-V/S) subscore ratio ≤ 1, and post-void residual (PVR) ≤ 250 mL were recruited into a prospective open-label study. All men received tolterodine ER (4 mg) daily. Global response assessment (GRA) ≥ 1 after treatment was considered successful treatment and an indication for continued antimuscarinic monotherapy. RESULTS: One hundred ninety-seven men aged 50-89 years (average TPV 44.4 mL) received first-line tolterodine monotherapy. Mean IPSS-T, IPSS storage (IPSS-S) subscore, and QOL improved significantly at 2, 4, and 12 weeks. Average PVR increased significantly; no patient developed acute urinary retention. One hundred thirty-six patients (69.0%) showed improvement (GRA ≥ 1) at both 2 and 4 weeks. Regression analysis showed that IPSS-S (P = .039) and maximum urine flow (Qmax, P = .033) were significant predictors of therapeutic success. Patients with smaller baseline TPV, higher IPSS-S, and higher Qmax had significantly higher treatment success rates. CONCLUSION: First-line antimuscarinic monotherapy is safe and effective within 12 weeks in selected patients with benign prostatic hyperplasia (BPH) Higher baseline IPSS-S, higher baseline Qmax, and lower TPV were predictors of successful antimuscarinic monotherapy.
Asunto(s)
Compuestos de Bencidrilo/uso terapéutico , Cresoles/uso terapéutico , Antagonistas Muscarínicos/uso terapéutico , Fenilpropanolamina/uso terapéutico , Hiperplasia Prostática/tratamiento farmacológico , Calidad de Vida , Anciano , Anciano de 80 o más Años , Endosonografía , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Hiperplasia Prostática/complicaciones , Hiperplasia Prostática/diagnóstico por imagen , Encuestas y Cuestionarios , Tartrato de Tolterodina , Resultado del Tratamiento , Retención Urinaria/etiología , Retención Urinaria/prevención & controlRESUMEN
We propose an amplitude-modulation chirp imaging method for contrast detection with high-frequency ultrasound. Our proposed method detects microbubbles by extracting and then selectively compressing the component of the backscattered chirp signal modulated by changes in the radii of microbubbles at their resonance frequency. Microbubbles are sonicated simultaneously with a narrowband, low-frequency pumping signal at their resonance frequency and a wideband, high-frequency imaging chirp signal. Changes in the radii of the resonant microbubbles result in periodic changes in their acoustic cross section that modulate the amplitude of the backscattered imaging chirp signal, forming pumping and imaging frequency sum-and-difference chirp terms. The frequency-sum or -difference chirp component is then extracted by a bandpass filter (BPF). Because a long imaging pulse duration is required to obtain a sufficient modulation depth on the chirp for contrast detection and to facilitate frequency-sum-and-difference signal extraction with the BPF, a chirp with a longer-than-usual waveform is used so pulse compression of the extracted chirp signal can then be performed to maintain the axial resolution, and even further improve the signal-to-noise ratio and contrast-to-tissue ratio. Experiments performed on flow phantoms with and without a speckle-generating background were performed to demonstrate the efficacy of the proposed technique. These results indicate that our proposed method can potentially provide high-resolution contrast detection in the microvasculature.