rose-bengal-mediated-photodynamic-therapy-to-inhibit-candida-albicans

Rose Bengal-Mediated Photodynamic Therapy to Inhibit <em>Candida albicans</em>

Invasive Candida albicans infection is a significant opportunistic fungal infection in humans because it is one of the most common colonizers of the gut, ...

National Cheng Kung University

A microelectrode array was designed to minimize the pain sensation of electroporation for enhancing transdermal drug delivery. The influence of the size of the electrode-skin contact area and of the distance between electrodes on the pain sensation was tested on human volunteers. The pain level decreased with the dimension of electrode-skin contact area and with inter-electrode distance. When both reached about 0.5 mm, the pain level was not perceptible even at the threshold of transdermal electroporation level of sixty electric pulses at 150 V, 1 ms at 1-10 Hz. An array of 11 x 11 alternately connected electrodes with 0.6 x 0.6 mm dimension was fabricated. The electric thresholds for effective drug delivery, using toluidine blue O as a marker on mouse skin, was found to be the same for microelectrode arrays as for larger electrodes and wider inter-electrode distances. In vivo transdermal electroporation using microelectrode array with 180 pulses of 150 V, 0.2 ms at 1 Hz, followed by 30 min methotrexate (MTX) occlusion increased more than 4 fold the systemic MTX level in mice. The results demonstrated the potential of painless delivery of significant amounts of chemotherapeutic agents through skin with the new electrode arrays in a clinical setting.

Painless electroporation with a new needle-free microelectrode array to enhance transdermal drug delivery.

An experiment was conducted to compare the effects of bilateral and unilateral stance on postural fluctuations and intralimb coordination during active balance control. Fifteen participants stood bilaterally and unilaterally while conducting a pointing task with an outstretched arm. Excursion of center of foot pressure (CoP) and limb movements were recorded with a force plate and eight dual-axis accelerometers, respectively. Compared to bilateral stance, unilateral stance resulted in wider CoP trajectories and greater postural fluctuations, especially in the lower limbs. The limb-dependent postural fluctuations during unilateral stance were associated with an increased coupling between the upper limb segments and a decreased coupling between the segments of the stance leg. Unilateral stance further resulted in greater regularity and spectral changes in postural fluctuations of the trunk and lower limb due to increased central oscillations (8-15 Hz). The observed structural differences in postural fluctuations between unilateral and bilateral stance strongly suggested that the postural control system modulates joint stiffness in a stance-dependent manner. Probably, in unilateral stance, attentive control was shifted to the stance leg at the expense of increasing arm stiffness to reduce movement redundancy.

Postural fluctuations during pointing from a unilateral or bilateral stance.

The study was conducted to contrast exertion-dependent changes in electromyography (EMG), force fluctuation (FF), and limb acceleration (LA) during isometric contraction to attain a versatile picture of muscle fatigue. Fifteen volunteers performed sustained index abduction at 25 and 75% maximal voluntary contractions (MVC) until failure at the tasks; meanwhile, changes in temporal/spectral features of force, muscle activity of the first dorsal interosseous (FDI), and acceleration of the index and hand were monitored. The results showed a manifest increase in all recorded signals for the 25% MVC paradigm, especially for LA, which demonstrated the largest increment in amplitude. In addition to progressive enhancement of the mechanical coupling of the metacarpophalangeal (MCP) joint, the 25% MVC paradigm added to EMG-FF and EMG-LA coherences (CohEMG-FF and CohEMG-LA) at 8-12 Hz and the shift of the spectral peak of the LA to higher frequencies. In contrast, the 75% MVC paradigm did not modulate significantly the spectral peak of LA. Also, CohEMG-FF, CohEMG-LA at 8-12 Hz, and the mechanical coupling of the MCP joint, were conversely undermined consequent to the high exertion paradigm. The present study suggests that LA was most susceptible to muscle fatigue following sustained contraction at a lower exertion level, and diverging alternations among various physiological signals ascribed to exertion-dependent contributions of central and peripheral origins to muscle fatigue.

Exertion dependent alternations in force fluctuation and limb acceleration during sustained fatiguing contraction.

In reference to electromyographic measurement, the study was conducted to reassess differences in the behavior of fatigue-related neuromuscular function between young and elderly humans with limb acceleration (LA). Fourteen young and fourteen elderly subjects performed sustained index abduction at 75% of their maximal voluntary contractions (MVC) until task failure. Measures of neuromuscular function, including temporal/spectral features of muscle activity of the first dorsal interosseous (FDI) and LA of the index and hand, were monitored. The results showed a manifest fatigue-induced increase in LA of the index in the elderly group, but not in the young group. In contrast, only the young group developed a significant increase in amplitude of the electromyography (EMG) until task failure. Spectral analyses of LA in the index reflected marked age-dependent reorganization following muscle fatigue, with a greater reduction of relative spectral amplitude of LA in the range of 20-40 Hz, but a lesser reduction in coherence between EMG and LA in the elderly group. In line with fatigue-associated restructuring of LA, the mechanical coupling of the metacarpophalangeal joint was more severely undermined in the elderly group than in the young group. The present study manifested an age-related difference in the relative contributions of neural versus mechanical factors to muscle fatigue. Subsequent to a high-level sustained submaximal isometric contraction, a predominant mechanical failure of the musculotendon complex in the elderly was featured with LA, whereas EMG measurement characterized prevailing impairment of neuromuscular propagation in the young.

Age effect on fatigue-induced limb acceleration as a consequence of high-level sustained submaximal contraction.

Powerline interference always disturbs recordings of biomedical signals. Numerous methods have been developed to reduce powerline interference. However, most of these techniques not only reduce the interference but also attenuate the 60 Hz power of the biomedical signals themselves. In the present study, we applied the S-transform, which provides an absolute phase of each frequency in a multi-resolution time-frequency analysis, to reduce 60 Hz interference. According to results from an electrocardiogram (ECG) to which a simulated 60 Hz noise was added, the S-transform de-noising process restored a power spectrum identical to that of the original ECG coincident with a significant reduction in the 60 Hz interference. Moreover, the S-transform de-noised the signal in an intensity-independent manner when reducing the 60 Hz interference. In both a real ECG signal from the MIT database and natural brain activity contaminated with 60 Hz interference, the S-transform also displayed superior merit to a notch filter in the aspect of reducing noise and preserving the signal. Based on these data, a novel application of the S-transform for removing powerline interference is established.

A novel application of the S-transform in removing powerline interference from biomedical signals.

We tested whether methylene blue, an inexpensive and safe photosensitizer, is feasible for photodynamic inactivation of enterovirus 71 (EV71) in the environment.

Methylene blue-mediated photodynamic inactivation as a novel disinfectant of enterovirus 71.

Rigorous research efforts have been undertaken worldwide to develop a needle-free insulin delivery for many decades with limited success. This translational study aims to deliver insulin through skin with painless electroporation.

Painless skin electroporation as a novel way for insulin delivery.

In this paper, an algorithm to extract respiration signals using a flexible projected capacitive sensing mattress (FPCSM) designed for personal health assessment is proposed. Unlike the interfaces of conventional measurement systems for poly-somnography (PSG) and other alternative contemporary systems, the proposed FPCSM uses projected capacitive sensing capability that is not worn or attached to the body. The FPCSM is composed of a multi-electrode sensor array that can not only observe gestures and motion behaviors, but also enables the FPCSM to function as a respiration monitor during sleep using the proposed approach. To improve long-term monitoring when body movement is possible, the FPCSM enables the selection of data from the sensing array, and the FPCSM methodology selects the electrodes with the optimal signals after the application of a channel reduction algorithm that counts the reversals in the capacitive sensing signals as a quality indicator. The simple algorithm is implemented in the time domain. The FPCSM system is used in experimental tests and is simultaneously compared with a commercial PSG system for verification. Multiple synchronous measurements are performed from different locations of body contact, and parallel data sets are collected. The experimental comparison yields a correlation coefficient of 0.88 between FPCSM and PSG, demonstrating the feasibility of the system design.

Design of a novel flexible capacitive sensing mattress for monitoring sleeping respiratory.

This study investigated fatigue-related modulation of common neural inputs to motor units (MUs) under 5 Hz, which determines force precision control.

Fatigue-related modulation of low-frequency common drive to motor units.

Blood flow restriction (BFR) is an innovation in fitness to train muscles with low loads at low oxygen levels. Low-level laser therapy (LLLT) is a bio-energetic approach to alleviate muscle fatigue during resistance training. This study investigated the immediate effect of LLLT pre-conditioning on BFR that accelerates muscle fatigue due to ischemia.

Acute physiological responses to combined blood flow restriction and low-level laser.

Older adults with degenerative declines in sensory systems depend strongly on visual input for postural control. By connecting advanced neural imaging and a postural control model, this study investigated the visual effect on the brain functional network that regulates feedback and feedforward processes of the postural system in older adults under somatosensory perturbations. Thirty-six older adults conducted bilateral stance on a foam surface in the eyes-open (EO) and eyes-closed (EC) conditions while their center of pressure (COP) and scalp EEG were recorded. The stochastic COP trajectory was modeled with non-linear stabilogram diffusion analysis (SDA) to characterize shifts in postural control in a continuum of feedback and feedforward processes. The EEG network was analyzed with the phase-lag index (PLI) and minimum spanning tree (MST). The results indicated that visual input rebalanced feedforward and feedback processes for postural sway, resulting in a greater critical point of displacement (CD), short-term effective diffusion coefficients (D) and short-term exponent (H), but the smaller critical point of time (CT) and long-term exponent (H) for the EC state. The EC network demonstrated stronger frontoparietal-occipital connectivity but weaker fronto-tempo-motor connectivity of the theta (4-7 Hz), alpha (8-12 Hz), and beta (13-35 Hz) bands than did the EO network. MST analysis revealed generally greater leaf fraction and maximal betweenness centrality (BC) and kappa of the EC network, as compared with those of the EO network. In contrast, the EC network exhibited a smaller diameter and average eccentricity than those of the EO network. The modulation of long-term negative feedback gain of the aged postural system with visual occlusion was positively correlated with leaf fraction, BC, and kappa, but negatively correlated with the diameter and average eccentricity for all EEG sub-bands. In conclusion, the aged brain functional network in older adults is tuned to visual information for modulating long-term negative feedback of the postural system under somatosensory perturbations.

Article	Year
Painless electroporation with a new needle-free microelectrode array to enhance transdermal drug delivery. Journal of controlled release : official journal of the Controlled Release Society\| PubMed ID: 16356576	2006
Postural fluctuations during pointing from a unilateral or bilateral stance. Human movement science\| PubMed ID: 16458377	2006
Exertion dependent alternations in force fluctuation and limb acceleration during sustained fatiguing contraction. European journal of applied physiology\| PubMed ID: 16770474	2006
Age effect on fatigue-induced limb acceleration as a consequence of high-level sustained submaximal contraction. European journal of applied physiology\| PubMed ID: 17440747	2007
A novel application of the S-transform in removing powerline interference from biomedical signals. Physiological measurement\| PubMed ID: 19039164	2009
Methylene blue-mediated photodynamic inactivation as a novel disinfectant of enterovirus 71. The Journal of antimicrobial chemotherapy\| PubMed ID: 20719762	2010
Painless skin electroporation as a novel way for insulin delivery. Diabetes technology & therapeutics\| PubMed ID: 21599516	2011
Design of a novel flexible capacitive sensing mattress for monitoring sleeping respiratory. Sensors (Basel, Switzerland)\| PubMed ID: 25420152	2014
Fatigue-related modulation of low-frequency common drive to motor units. European journal of applied physiology\| PubMed ID: 32297005	2020
Acute physiological responses to combined blood flow restriction and low-level laser. European journal of applied physiology\| PubMed ID: 32318813	2020
Visual Effect on Brain Connectome That Scales Feedforward and Feedback Processes of Aged Postural System During Unstable Stance. Frontiers in aging neuroscience\| PubMed ID: 34366825	2021

Chien-Chun Huang

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