A sustainable
microplasma synthesis of GQDs as fluorescent sensors
for Cu2+ detection is reported. The GQDs are synthesized
from starch at ambient conditions using microplasma–liquid
synthesis. The prepared GQDs exhibit selective detection of Cu2+ with high quenching ratio and low limit of detection (LoD)
of 0.5 μM. Detailed density functional theory (DFT) and time-dependent
DFT (TD-DFT) calculations show that fluorescence quenching occurs
due to the forbidden emission process of the excited electrons. This
work presents a sustainable and scalable method to synthesize GQDs
and provides insight into the charge transfer process for fluorescent-based
metal ion detection.
Environmental contamination and energy shortage are among
the most
critical global issues that require urgent solutions to ensure sustainable
ecological balance. Rapid and ultrasensitive monitoring of water quality
against pollutant contaminations using a low-cost, easy-to-operate,
and environmentally friendly technology is a promising yet not commonly
available solution. Here, we demonstrate the effective use of plasma-converted
natural bioresources for environmental monitoring. The energy-efficient
microplasmas operated at ambient conditions are used to convert diverse
bioresources, including fructose, chitosan, citric acid, lignin, cellulose,
and starch, into heteroatom-doped graphene quantum dots (GQDs) with
controlled structures and functionalities for applications as fluorescence-based
environmental nanoprobes. The simple structure of citric acid enables
the production of monodispersed 3.6 nm averaged-size GQDs with excitation-independent
emissions, while the saccharides including fructose, chitosan, lignin,
cellulose, and starch allow the synthesis of GQDs with excitation-dependent
emissions due to broader size distribution. Moreover, the presence
of heteroatoms such as N and/or S in the chemical structures of chitosan
and lignin coupled with the highly reactive species generated by the
plasma facilitates the one-step synthesis of N, S-codoped GQDs, which
offer selective detection of toxic environmental contaminants with
a low limit of detection of 7.4 nM. Our work provides an insight into
the rapid and green fabrication of GQDs with tunable emissions from
natural resources in a scalable and sustainable manner, which is expected
to generate impact in the environmental safety, energy conversion
and storage, nanocatalysis, and nanomedicine fields.
Single-electron transistors (SETs) represent a new generation of electronic devices with high charge sensitivity, high switching speed, and low power consumption. Here a simple and controlled fabrication of graphene quantum dot (GQD)-based SETs for photon detectors has been demonstrated. The plasmasynthesized GQDs exhibit stable photoluminescence and are successfully used as the Coulomb islands between heteroepitaxial spherical-gold/platinum (HS-Au/Pt) nanogap electrodes. The as-fabricated GQD-SETs enable photon detection with 410 nm excitation owing to the ability of GQDs to generate photoluminescence emission.
Individuals with cervical spinal cord injury (C-SCI) often use a tenodesis grip to compensate for their hand function deficits. Although clinical evidence confirms that assistive devices can help achieve hand function improvements, the currently available devices have some limitations in terms of their price and accessibility and the difference in the user's muscle strength. Therefore, in this study, we developed a 3D-printed wrist-driven orthosis to improve the gripping effect and tested the feasibility of this device by assessing its functional outcomes. A total of eight participants with hand function impairment due to a C-SCI were enrolled, and a wrist-driven orthosis with a triple four-bar linkage was designed. The hand function of the participants was assessed before and after they wore the orthosis, and the outcomes were assessed using a pinch force test, a dexterity test (Box and block test, BBT), and a Spinal Cord Independence Measure Version III questionnaire. In the results, before the participants wore the device, the pinch force was 0.26 lb. However, after they wore the device, it increased by 1.45 lb. The hand dexterity also increased by 37%. After 2 weeks, the pinch force increased by 1.6 lb and the hand dexterity increased by 78%. However, no significant difference was observed in the self-care ability. The results showed that this 3D-printed device with a triple four-bar linkage for individual with C-SCI improved pinch strength and hand dexterity in these patients, but did not improve their self-care ability. It may help patient in the early stages of C-SCI to learn and use the tenodesis grip easily. However, the usability of the device in daily life needs further research.
Date Presented 03/27/20
We explored the experiences of clients and their therapists using strategy training in outpatient settings in Taiwan with qualitative data to understand the benefits and challenges that they perceived during the intervention. Findings of this study support the use of strategy training in individuals with chronic stroke and brain injury and indicate potential challenges that OTs may encounter as delivering strategy training to clients in outpatient settings in Taiwan.
Primary Author and Speaker: Feng-Hang Chang
Additional Authors and Speakers: Chao-Yi Wu, Elizabeth Skidmore
Contributing Authors: Wan-Chi Lin, Yi-Hsuan Wu, Pei-Chun Yeh, Yen-Nung Lin
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