Ultrathin Self-Powered Heavy-Metal-Free Cu-In-Se Quantum Dot Photodetectors for Wearable Health Monitoring.

Mechanically deformable photodetectors (PDs) are key device components for wearable health monitoring systems based on photoplethysmography (PPG). Achieving high detectivity, fast response time, and an ultrathin form factor in the PD is highly needed for next-generation wearable PPG systems. Self-powered operation without a bulky power-supply unit is also beneficial for point-of-care application. Here, we propose ultrathin self-powered PDs using heavy-metal-free Cu-In-Se quantum dots (QDs), which enable high-performance wearable PPG systems. Although the light-absorbing QD layer is extremely thin (∼40 nm), the developed PD exhibits excellent performance (specific detectivity: 2.10 × 1012 Jones, linear dynamic range: 102 dB, and spectral range: 250-1050 nm at zero bias), which is comparable to that of conventional rigid QD-PDs employing thick Pb-chalcogenide QD layers. This is attributed to material and device strategies─materials that include Cu-In-Se QDs, a MoS2-nanosheet-blended poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) hole transport layer, a ZnO nanoparticle electron transport layer, Ag and ITO electrodes, and an ultrathin form factor (∼120 nm except the electrodes) that enable excellent mechanical deformability. These allow the successful application of QD-PDs to a wearable system for real-time PPG monitoring, expanding their potential in the field of mobile bioelectronics.

Ultrahigh-resolution full-color perovskite nanocrystal patterning for ultrathin skin-attachable displays.

High-definition red/green/blue (RGB) pixels and deformable form factors are essential for the next-generation advanced displays. Here, we present ultrahigh-resolution full-color perovskite nanocrystal (PeNC) patterning for ultrathin wearable displays. Double-layer transfer printing of the PeNC and organic charge transport layers is developed, which prevents internal cracking of the PeNC film during the transfer printing process. This results in RGB pixelated PeNC patterns of 2550 pixels per inch (PPI) and monochromic patterns of 33,000 line pairs per inch with 100% transfer yield. The perovskite light-emitting diodes (PeLEDs) with transfer-printed active layers exhibit outstanding electroluminescence characteristics with remarkable external quantum efficiencies (15.3, 14.8, and 2.5% for red, green, and blue, respectively), which are high compared to the printed PeLEDs reported to date. Furthermore, double-layer transfer printing enables the fabrication of ultrathin multicolor PeLEDs that can operate on curvilinear surfaces, including human skin, under various mechanical deformations. These results highlight that PeLEDs are promising for high-definition full-color wearable displays.

Cross-sectional area reference values of nerves in the lower extremities using ultrasonography.

INTRODUCTION: Cross-sectional area (CSA) reference values of lower extremity nerves using ultrasonography have only been reported in a few studies and have been limited to white populations. METHODS: For this study, 94 healthy Korean volunteers were recruited for measurement of the CSA at 7 sites of lower extremity nerves. The side-to-side difference in CSA was calculated for each nerve, and reference ranges were derived. External validity evaluation for the reference values was performed with 10 newly recruited volunteers at a different institution. RESULTS: Nerve CSA was correlated significantly with body mass index, weight, and height; however, the absolute value of the side-to-side difference had no significant correlation with demographic factors. The external validity was adequate for all sites, ranging from 80% to 100%. CONCLUSIONS: The lower extremity nerve CSA values obtained in this study may provide normal reference values for the Asian population.

Pattern analysis of nerve enlargement using ultrasonography in chronic inflammatory demyelinating polyneuropathy.

OBJECTIVE: Focal nerve enlargement is a characteristic finding in chronic inflammatory demyelinating polyneuropathy (CIDP). We performed this study to assess the distribution of nerve enlargement through ultrasonographic examination of peripheral nerves and to correlate the ultrasonographic findings with clinical features. METHODS: To compare the ultrasonographic features of 10 subjects with CIDP with those of 18 healthy controls, we bilaterally measured the cross-sectional areas (CSA) of the vagus, brachial plexus, musculocutaneous, median, ulnar, radial, sciatic, tibial, common peroneal, and sural nerves. We also analyzed correlations between CSAs and various clinical and electrophysiological features. RESULTS: Mean CSAs were significantly larger in CIDP patients than controls, especially at proximal and non-entrapment sites. CSAs were significantly correlated with muscle strength at initial presentation, but not at the time of ultrasonography. The CSAs of the median and ulnar nerves at the mid-forearm, tibial nerve at 7 cm proximal to the medial malleolus, and sural nerve correlated with the nerve conduction velocity of the corresponding region. CONCLUSION: Ultrasonography revealed widely distributed nerve enlargement, especially in proximal regions and non-entrapment sites, in patients with CIDP compared with healthy controls. Nerve enlargement correlated well with the electrophysiologic function of the nerve, but not current clinical status. SIGNIFICANCE: Pattern analysis of nerve enlargement using ultrasonography is a supportive tool in the diagnosis of CIDP.

Multichannel surface electrodes increase the sensitivity of diagnosis of neuropathy in diabetic patients.

This prospective study investigated the diagnostic sensitivity of a novel multichannel surface electrode for detecting electrophysiologic changes in symptomatic diabetic neuropathy. We recruited healthy subjects without neuropathic complaints and diabetic patients with distal symmetric sensory symptoms who had normal nerve conduction studies (NCS). Eight compound muscle action potentials (CMAPs) were recorded using a multichannel electrode from each subject's abductor pollicis brevis muscle by stimulating the median nerve at the wrist. Latency- and amplitude-related variables were obtained and analyzed to compare the two groups. We used the Classification and Regression Tree (CART) algorithm to determine the cut-off values for selected predictors of diabetic neuropathy. All of the variables related to CMAP latency showed statistically significant differences between the median values for the diabetic group and the healthy control group. For example, the median value of the maximum latency and standard deviation of the eight CMAP onset latencies in diabetic patients (3.82ms and 0.15ms, respectively) were significantly larger than those in controls (3.26ms and p<0.001; 0.09ms and p<0.001, respectively). The CART analysis revealed that these variables were the most sensitive and specific variables for discriminating between patients with diabetic neuropathy and normal subjects. The multichannel surface electrode demonstrated both high sensitivity and specificity in detecting neurophysiologic abnormality of diabetic neuropathy, even when conventional NCS did not detect the abnormality.

Alpha-Type 1 Polarized Dendritic Cells Loaded with Apoptotic Allogeneic Breast Cancer Cells Can Induce Potent Cytotoxic T Lymphocytes against Breast Cancer.

PURPOSE: Various tumor antigens can be loaded onto dendritic cells (DCs) to induce a potent cytotoxic T lymphocyte (CTL) response in DC-based immunotherapy against breast cancer. However, in the clinical setting, obtaining a sufficient number of autologous tumor cells as a source of tumor antigens is a laborious process. We therefore investigated the feasibility of immunotherapy using breast-cancer-specific CTLs generated in vitro by use of alpha-type 1 polarized DCs (α DC1s) loaded with ultraviolet B-irradiated cells of the breast cancer cell line MCF-7. MATERIALS AND METHODS: αDC1s were induced by loading allogeneic tumor antigen generated from the MCF-7 UVB-irradiated breast cancer cell line. Antigen-pulsed αDC1s were evaluated by morphological and functional assays, and the breast-cancer-specific CTL response was analyzed by cytotoxic assay. RESULTS: The αDC1s significantly increased the expression of several molecules related to DC maturation without differences according to whether the αDC1s were loaded with tumor antigens. The αDC1s showed a high production of interleukin-12 both during maturation and after subsequent stimulation with CD40L, which was not significantly affected by loading with tumor antigens. Breast-cancer-specific CTLs against autologous breast cancer cells were successfully induced by αDC1s loaded with apoptotic MCF-7 cells. CONCLUSION: Autologous DCs loaded with an allogeneic breast cancer cell line can generate potent breast-cancer-specific CTL responses. This may be a practical method for cellular immunotherapy in patients with breast cancer.