Short-Term Effects of Ginkgo biloba Extract on Peripapillary Retinal Blood Flow in Normal Tension Glaucoma

PURPOSE: Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG). METHODS: Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed. RESULTS: After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area. CONCLUSIONS: GBE administration appears to have desirable effect on ocular blood flow in NTG patients.ope

Enhanced Solubility of the Support in an FDM-Based 3D Printed Structure Using Hydrogen Peroxide under Ultrasonication

Fused deposition modeling (FDM), one of the archetypal 3D printing processes, typically requires support structures matched to printed model parts that principally have undercut or overhung features. Thus, the support removal is an essential postprocessing step after the FDM process. Here, we present an efficient and rapid method to remove the support part of an FDM-manufactured product using the phenomenon of oxidative degradation of hydrogen peroxide. This mechanism was significantly effective on polyvinyl alcohol (PVA), which has been widely used as a support material in the FDM process. Compared to water, hydrogen peroxide provided a two times faster dissolution rate of the PVA material. This could be increased another two times by applying ultrasonication to the solvent. In addition to the rapidness, we confirmed that amount of the support residues removed was enhanced, which was essentially caused by the surface roughness of the FDM-fabricated part. Furthermore, we demonstrated that there was no deterioration with respect to the mechanical properties or shape geometries of the obtained 3D printed parts. Taken together, these results are expected to help enhance the productivity of FDM by reducing the postprocessing time and to allow the removal of complicated and fine support structures, thereby improving the design capability of the FDM technique

Relationship between the Retinal Thickness Analyzer and the GDx VCC Scanning Laser Polarimeter, Stratus OCT Optical Coherence Tomograph, and Heidelberg Retina Tomograph II Confocal Scanning Laser Ophthalmoscopy

PURPOSE: To assess the relationship between the retinal thickness analyzer (RTA) parameters, and those of the GDx VCC scanning laser polarimeter (GDx VCC), Stratus OCT optical coherence tomography (Stratus OCT), and Heidelberg retinal tomograph II confocal scanning laser ophthalmoscopy (HRT II). METHODS: Twenty-nine primary open-angle glaucoma patients were retrospectively included in this study. Measurements were obtained using the RTA, GDx VCC, Stratus OCT, and HRT II. We calculated the correlation coefficients between the parameters of RTA and those of the other studies. RESULTS: Among the optic disc parameters of RTA, the cup volume was best correlated with Stratus OCT (R=0.780, p<0.001) and HRT II (R=0.896, p<0.001). Among the posterior pole retinal thickness parameters, the posterior pole abnormally thin area (PPAT) of the RTA and the inferior average of the GDx VCC were best correlated (R=-0.596, p=0.001). The PPAT of the RTA and the inferior maximum of the Stratus OCT were best correlated (R=-0.489, p=0.006). The perifoveal minimum thickness (PFMT) of the RTA and the cup shape measurement of the HRT II were best correlated (R=-0.565, p=0.004). CONCLUSIONS: Many RTA optic disc parameters were significantly correlated with those of the Stratus OCT and HRT II. The RTA posterior pole retinal thickness parameters were significantly correlated with those of the GDx VCC, Stratus OCT and HRT II. The RTA optic disc and posterior pole retinal thickness parameters may be valuable in the diagnosis of glaucomaope

The effects of wearing KF94 masks on cardiorespiratory function and hemorheological response during moderate intensity exercise in adult males

The purpose of this study was to examine the effect of wearing a Korea filter 94 (KF94) mask on cardiorespiratory function and hemorheological responses during moderate intensity exercise in men during the Coronavirus disease 2019 (COVID-19) pandemic. 12 healthy males aged 20 to 29 years (28.3 ± 3.6 yr) were recruited for this study. The exercise intensity corresponding to the anaerobic threshold level was determined following a maximum graded exercise test, and exercise was performed for 40 minutes with a cycle ergometer at the target exercise intensity. Cardiorespiratory function, blood pressure, and hemorheological responses were measured every 10 minutes at rest and during exercise. Our results indicated no differences between conditions in respiratory frequency (Rf), tidal volume (TV), minute ventilation (VE), carbon dioxide production (V̇CO2), and partial pressure of arterial oxygen (PaO2). However, oxygen consumption (V̇O2) was significantly lower in the KF94 mask group compared to the control. There were no differences in systolic blood pressure (SBP), diastolic blood pressure (DBP), rate pressure product (RPP), aggregation index (AI), and blood critical stress (BCS) between the two groups. The mask group had a significant respiratory exchange ratio (R) at rest and during 10 minutes exercise compared to the control. The elongation index was higher at rest, 10 minutes, and 30 minutes in the mask group than control group (p < 0.05). Overall, our results suggest that although V̇O2 was decreased and R values were increased, the effects of other physiological parameters and hemorheological responses imposed by face masks during moderate intensity exercise are small. Thus, although negative effects of using face masks affect exercise capacity (i.e., exercise tolerance), our findings suggest that individuals wearing KF94 could safely exercise and get some health benefits from physical activities during the COVID-19 pandemic

A Multimodal Neural Activity Readout Integrated Circuit for Recording Fluorescence and Electrical Signals

Monitoring the electrical neural signals is an important method for understanding the neuronal mechanism. In particular, in order to perform a cell-type-specific study, it is necessary to observe the concentration of calcium ions using fluorescent indicators in addition to measuring the electrical neural signal. This paper presents a multimodal multichannel neural activity readout integrated circuit that can perform not only electrical neural recording but also fluorescence recording of neural activity for the cell-type-specific study of heterogeneous neuronal cell populations. For monitoring the calcium ions, the photodiode generates the current according to the fluorescence expressed by the reaction between the genetically encoded calcium indicators and calcium ions. The time-based fluorescence recording circuit then records the photodiode current. The electrical neural signal captured by the microelectrode is recorded through the low-noise amplifier, variable gain amplifier, and analog-to-digital converter. The proposed integrated circuit is fabricated in a 1-poly 6-metal (1P6M) 0.18- ??m CMOS process. The fluorescence recording circuit achieves a recording range of 81 dB (75 pA to 860 nA) and consumes a power of 724 nW/channel. The electrical recording circuit achieves an input-referred noise of 2.7 ??Vrms over the bandwidth of 10 kHz, while consuming the power of 4.9 ??W /channel. The functionality of the proposed circuits is verified through the in vivo and in vitro experiments. Compared to the conventional neuroscience tools, which consist of bulky off-chip components, this neural interface is implemented in a compact size to perform multimodal neural recording while consuming low power