Nonlinear photoacoustic microscopy via a loss modulation technique: from detection to imaging

In order to achieve high-resolution deep-tissue imaging, multi-photon fluorescence microscopy and photoacoustic tomography had been proposed in the past two decades. However, combining the advantages of these two imaging systems to achieve optical-spatial resolution with an ultrasonic-penetration depth is still a field with challenges. In this paper, we investigate the detection of the two-photon photoacoustic ultrasound, and first demonstrate background-free two-photon photoacoustic imaging in a phantom sample. To generate the background-free two-photon photoacoustic signals, we used a high-repetition rate femtosecond laser to induce narrowband excitation. Combining a loss modulation technique, we successfully created a beating on the light intensity, which not only provides pure sinusoidal modulation, but also ensures the spectrum sensitivity and frequency selectivity. By using the lock-in detection, the power dependency experiment validates our methodology to frequency-select the source of the nonlinearity. This ensures our capability of measuring the background-free two-photon photoacoustic waves by detecting the 2nd order beating signal directly. Furthermore, by mixing the nanoparticles and fluorescence dyes as contrast agents, the two-photon photoacoustic signal was found to be enhanced and detected. In the end, we demonstrate subsurface two-photon photoacoustic bio-imaging based on the optical scanning mechanism inside phantom samples

Separation Enhancement of Mechanical Filters by Adding Negative Air Ions

The purpose of this work is to combine negative air ions (NAIs) and mechanical filters for removal of indoor suspended particulates. Various factors, including aerosol size (0.05-0.45 μm), face velocity (10 and 20 cm/s), species of aerosol (potassium chloride and dioctyl phthalate), relative humidity (30% and 70%), and concentrations of NAIs (2 ´ 104, 1 ´ 105, and 2 ´ 105 NAIs/cm3) were considered to evaluate their effects on the aerosol collection characteristics of filters. Results show that the aerosol penetration through the mechanical filter is higher than that through the mechanical filters cooperated with NAIs. This finding implies that the aerosol removal efficiency of mechanical filters can be improved by NAIs. Furthermore, the aerosol penetration through the mechanical filters increased with the aerosol size when NAIs were added. That is due to that the aerosol is easier to be charged when its size gets larger. The results also indicate the aerosol penetration decreased with the NAIs concentration increased. Reversely, aerosol penetration through the mechanical filters increased with the face velocity under the influence of NAIs. The aerosol penetration through the filter with NAIs was no affected with relative humidity. Finally, The penetration through the filter with NAIs against solid aerosol was lower than that against liquid aerosol

Transcutaneous Electrical Stimulation of Acupoints Changes Body Composition and Heart Rate Variability in Postmenopausal Women with Obesity

This study aimed to evaluate the effect of transcutaneous electric acupoint stimulations (TEAS) on body composition and heart rate variability (HRV) in postmenopausal women with obesity. In this prospective study, 49 postmenopausal women were recruited in Taiwan. Body composition was used as a screening test for obesity (percentage body fat > 30%, waist circumference > 80 cm). The experimental group (n = 24) received TEAS treatment 30 min twice per week for 12 weeks at the Zusanli (ST 36) and Sanyinjiao (SP 6) acupoints. The control group (n = 25) did not receive any intervention. The study of HRV was analyzed by time (standard deviation of the normal-to-normal (NN) intervals (SDNN) and square root of the mean squared differences of successive NN intervals (RMSSD) indices) and frequency domain methods. Power spectral components were obtained at low (LF) and high (HF) frequencies. Body composition and HRV values were measured at the 4th, 8th, and 12th weeks. A total of 40 subjects completed this study. Waist circumference and percentage body fat in the experimental group (n = 20) were significantly less than those of the control group (n = 20) at the 8th and 12th weeks (all P < .05). Additionally, at the same time points, percentage lean body mass in the experimental group was significantly greater than that in the control group (P < .05). SDNN values increased significantly at the 4th and 8th weeks when compared with the control group (all P < .05). At 12 weeks, SDNN value was not significantly different from that of the control group (P = .105). TEAS treatment improves body composition, and has a transient effect on the HRV in postmenopausal women with obesity

Small-Size Humanoid Soccer Robot Design for FIRA HuroSot

Non

In vivo sub-femtoliter resolution photoacoustic microscopy with higher frame rates

Microscopy based on non-fluorescent absorption dye staining is widely used in various fields of biomedicine for 400 years. Unlike its fluorescent counterpart, non-fluorescent absorption microscopy lacks proper methodologies to realize its in vivo applications with a sub-femtoliter 3D resolution. Regardless of the most advanced high-resolution photoacoustic microscopy, sub-femtoliter spatial resolution is still unattainable, and the imaging speed is relatively slow. In this paper, based on the two-photon photoacoustic mechanism, we demonstrated a in vivo label free laser-scanning photoacoustic imaging modality featuring high frame rates and sub-femtoliter 3D resolution simultaneously, which stands as a perfect solution to 3D high resolution non-fluorescent absorption microscopy. Furthermore, we first demonstrated in vivo label-free two-photon acoustic microscopy on the observation of non-fluorescent melanin distribution within mouse skin

Integrin-mediated membrane blebbing is dependent on the NHE1 and NCX1 activities.

Integrin-mediated signal transduction and membrane blebbing have been well studied to modulate cell adhesion, spreading and migration^1-6^. However, the relationship between membrane blebbing and integrin signaling has not been explored. Here we show that integrin-ligand interaction induces membrane blebbing and membrane permeability change. We found that sodium-proton exchanger 1 (NHE1) and sodium-calcium exchanger 1 (NCX1) are located in the membrane blebbing sites and inhibition of NHE1 disrupts membrane blebbing and decreases membrane permeability change. However, inhibition of NCX1 enhances cell blebbing to cause cell swelling which is correlated with an intracellular sodium accumulation induced by NHE17. These data suggest that sodium influx induced by NHE1 is a driving force for membrane blebbing growth, while sodium efflux induced by NCX1 in a reverse mode causes membrane blebbing retraction. Together, these data reveal a novel function of NHE1 and NCX1 in membrane permeability change and blebbing and provide the link for integrin signaling and membrane blebbing

Interpersonal Relationships among University Safety Professionals: The Impact of a Safety Departmentf

PresentationForming strong interpersonal relationships enables an organization or individual to achieve more favorable outcomes. The objectives of this study were to examine the frequency of interpersonal interactions among safety professionals (SPs) employed at Taiwanese universities and the factors that affected this frequency. To accomplish these objectives, we mailed questionnaires to a simple random sampling of 200 university SPs. Moreover, an interpersonal relationship scale was developed in this study; exploratory factor and internal consistency analyses revealed that the scale was valid and reliable. Results derived from the questionnaire revealed that in SP interpersonal relationships, general affairs department personnel, laboratory or internship unit supervisors, and teaching staff ranked highest in frequency of interactions. Multivariate analysis of variance results showed that establishing a safety department exerted a statistically significant effect on SP interpersonal relationships. SPs employed by universities with safety departments interacted more frequently with both internal and external relationships. Therefore, we suggest that universities without a safety department establish such a department to strengthen the labor safety and health structure, thereby benefitting SPs in fulfilling responsibilities to promote safety and health management