Hydrophobic sponge structure‐based triboelectric nanogenerators using an inverse opal structured film for sustainable energy harvesting over a wide range of humid atmosphere have been successfully ...demonstrated. The output voltage and current density reach a record value of 130 V and 0.10 mA cm−2, respectively, giving over 10‐fold power enhancement, compared with the flat film‐based triboelectric nanogenerator.
A new, highly conductive (4.1 × 10−4 S cm−1 at 30 °C), highly deformable, and dry‐air‐stable glass 0.4LiI‐0.6Li4SnS4 is prepared using a homogeneous methanol solution. The solution process enables ...the wetting of any exposed surface of the active materials with highly conductive solidified electrolytes (0.4LiI‐0.6Li4SnS4), resulting in considerable improvements in the electrochemical performance of these electrodes over conventional mixture electrodes.
Abstract
Thermoelectric power generation offers a promising way to recover waste heat. The geometrical design of thermoelectric legs in modules is important to ensure sustainable power generation but ...cannot be easily achieved by traditional fabrication processes. Herein, we propose the design of cellular thermoelectric architectures for efficient and durable power generation, realized by the extrusion-based 3D printing process of Cu
2
Se thermoelectric materials. We design the optimum aspect ratio of a cuboid thermoelectric leg to maximize the power output and extend this design to the mechanically stiff cellular architectures of hollow hexagonal column- and honeycomb-based thermoelectric legs. Moreover, we develop organic binder-free Cu
2
Se-based 3D-printing inks with desirable viscoelasticity, tailored with an additive of inorganic Se
8
2−
polyanion, fabricating the designed topologies. The computational simulation and experimental measurement demonstrate the superior power output and mechanical stiffness of the proposed cellular thermoelectric architectures to other designs, unveiling the importance of topological designs of thermoelectric legs toward higher power and longer durability.
Brain organoids derived from human pluripotent stem cells provide a highly valuable in vitro model to recapitulate human brain development and neurological diseases. However, the current systems for ...brain organoid culture require further improvement for the reliable production of high-quality organoids. Here, we demonstrate two engineering elements to improve human brain organoid culture, (1) a human brain extracellular matrix to provide brain-specific cues and (2) a microfluidic device with periodic flow to improve the survival and reduce the variability of organoids. A three-dimensional culture modified with brain extracellular matrix significantly enhanced neurogenesis in developing brain organoids from human induced pluripotent stem cells. Cortical layer development, volumetric augmentation, and electrophysiological function of human brain organoids were further improved in a reproducible manner by dynamic culture in microfluidic chamber devices. Our engineering concept of reconstituting brain-mimetic microenvironments facilitates the development of a reliable culture platform for brain organoids, enabling effective modeling and drug development for human brain diseases.
Data on the comparative effectiveness of oral antidiabetics on cardiovascular outcomes in a clinical practice setting are limited. This study sought to determine whether a differential risk of ...cardiovascular disease (CVD) exists for the combination of a dipeptidyl peptidase-4 (DPP-4) inhibitor plus metformin versus a sulfonylurea derivative plus metformin or pioglitazone plus metformin.
We conducted a cohort study of 349,476 patients who received treatment with a DPP-4 inhibitor, sulfonylurea, or pioglitazone plus metformin for type 2 diabetes using the Korean national health insurance claims database. The incidence of total CVD and individual outcomes of myocardial infarction (MI), heart failure (HF), and ischemic stroke (IS) were assessed using the hazard ratios (HRs) estimated from a Cox proportional-hazards model weighted for a propensity score.
During follow-up, 3,881 patients developed a CVD, including 428 MIs, 212 HFs, and 1,487 ISs. The adjusted HR with 95% confidence interval (CI) for a sulfonylurea derivative plus metformin compared with a DPP-4 inhibitor plus metformin was 1.20 (1.09-1.32) for total CVD; 1.14 (1.04-1.91) for MI; 1.07 (0.71-1.62) for HF; and 1.51 (1.28-1.79) for IS. The HRs with 95% CI for total CVD, MI, HF, and IS for pioglitazone plus metformin were 0.89 (0.81-0.99), 1.05 (0.76-1.46), 4.81 (3.53-6.56), and 0.81 (0.67-0.99), respectively.
Compared with a DPP-4 inhibitor plus metformin, treatment with a sulfonylurea drug plus metformin was associated with increased risks of total CVD, MI, and IS, whereas the use of pioglitazone plus metformin was associated with decreased total CVD and IS risks.
Considering the potential applications of all‐polymer solar cells (all‐PSCs) as wearable power generators, there is an urgent need to develop photoactive layers that possess intrinsic mechanical ...endurance, while maintaining a high power‐conversion efficiency (PCE).Herein a strategy is demonstrated to simultaneously control the intercalation behavior and nanocrystallite size in the polymer–polymer blend by using a newly developed, high‐viscosity polymeric additive, poly(dimethylsiloxane‐co‐methyl phenethylsiloxane) (PDPS), into the TQ‐F:N2200 all‐PSC matrix. A mechanically robust 10wt% PDPS blend film with a great toughness was obtained. Our results provide a feasible route for producing high‐performance ductile all‐PSCs, which can potentially be used to realize stretchable all‐PSCs as a linchpin of next‐generation electronics.
A mechanically robust photoactive layer, namely 10PDPS is achieved, enabling not only a high PCE of 6.87 % in conventional all‐PSCs but also a reliable PCE of 5.60 % in graphene electrode‐based flexible devices, for which 90 % of its PCE is retained after 100 bending cycles at a bending radius of 3 mm.
Various wearable electronic devices have been developed for extensive outdoor activities. The key metrics for these wearable devices are high touch sensitivity and good mechanical and thermal ...stability of the flexible touchscreen panels (TSPs). Their dielectric constants (k) are important for high touch sensitivities. Thus, studies on flexible and transparent cover layers that have high k with outstanding mechanical and thermal reliabilities are essential. Herein, an unconventional approach for forming flexible and transparent cellulose nanofiber (CNF) films is reported. These films are used to embed ultralong metal nanofibers that serve as nanofillers to increase k significantly (above 9.2 with high transmittance of 90%). Also, by controlling the dimensions and aspect ratios of these fillers, the effects of their nanostructures and contents on the optical and dielectric properties of the films have been studied. The length of the nanofibers can be controlled using a stretching method to break the highly aligned, ultralong nanofibers. These nanofiber‐embedded, high‐k films are mechanically and thermally stable, and they have better Young's modulus and tensile strength with lower thermal expansion than commercial transparent plastics. The demonstration of highly sensitive TSPs using high‐k CNF film for smartphones suggests that this film has significant potential for next‐generation, portable electronic devices.
Transparent and flexible cellulose films with a high dielectric performance using ultralong metal nanofibers are key attributes for flexible touchscreen panels (TSPs). High‐dielectric‐constant (k) CNF films using ultralong silver nanofibers have outstanding optical transmittance (≈90%) with high‐k values (k = 9.2 at 120 kHz). A TSP that is protected with a high‐k CNF film shows high touch sensitivity.
We performed a prospective survey on the adverse reactions following the first dose of two types of vaccines against coronavirus disease 2019 (COVID-19) in healthcare workers (HCWs) in South Korea.
...HCWs at a tertiary referral hospital in Seoul, South Korea, received a chimpanzee adenovirus-vectored vaccine (ChAdOx1 nCoV-19) or an mRNA-based vaccine (BNT162b2) between March 5 and March 26, 2021. The HCWs were asked to report adverse reactions through a mobile self-report questionnaire for three days after vaccination.
A total of 7,625 HCWs received the first dose of ChAdOx1 or BNT162b2 vaccine during the study period. Of them, 5,866 (76.9%) HCWs (ChAdOx1, n = 5,589 95.3%; BNT162b2, n = 277 4.7%) participated at least once in the survey, of whom 77% were female and 86% were younger than 50 years. The overall adverse reaction rate was 93% in the ChAdOx1 group and 80% in the BNT162b2 group (
< 0.001). Both local and systemic reactions were more commonly reported in the ChAdOx1 group, and the difference was larger in systemic reactions such as fever and fatigue. In the ChAdOx1 group, the incidence of adverse reactions was significantly higher in females and those in the younger age groups, while the BNT162b2 group showed such difference according to age.
In our prospective survey, vaccine-associated adverse reactions were more commonly reported in the ChAdOx1 group than in the BNT162b2 group. Females and younger age groups experienced vaccine-associated adverse reactions more frequently.
We aimed to identify whether neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are more useful predictors after initial intention to treat than at the time of diagnosis.
We ...collected the medical data of 533 patients. The results of the peripheral blood sampling before the primary treatments were labeled as initial cohort, and those obtained between 24 and 36 months after initial treatment were defined as the 2nd cohort. Delayed metastasis has been defined as distant metastasis 2 years after treatment, and survival outcome was estimated and compared across groups.
Median follow-up duration was 74 months (24-162 months), and 53 patients experienced delayed metastasis. In univariate analysis, metastasis-free survival, patient age at diagnosis, tumor size, axillary lymph node metastasis, HER-2 status, initial NLR and PLR, and 2nd NLR and PLR were found to be significantly associated with delayed metastasis. However, in multivariate analysis, only the 2nd NLR and PLR were found to be significantly associated with delayed metastasis, excluding initial NLR and PLR. Metastasis-free survival was analyzed through the pattern changes of NLR or PLR. The results revealed that patients with continued low NLR and PLR values at pre- and post-treatment (low initial values and 2nd values) showed a significantly better prognosis than those with a change in value or continued high NLR and PLR.
We identified that patients with persistent high NLR and PLR after initial treatment have significant worse prognosis in terms of late metastasis. Therefore, these results suggest that NLR and PLR are more useful in predicting prognosis post-treatment.
Compared with the large plastic deformation observed in ductile metals and organic materials, inorganic semiconductors have limited plasticity (<0.2%) due to their intrinsic bonding characters, ...restricting their widespread applications in stretchable electronics. Herein, the solution‐processed synthesis of ductile α‐Ag2S thin films and fabrication of all‐inorganic, self‐powered, and stretchable memory devices, is reported. Molecular Ag2S complex solution is synthesized by chemical reduction of Ag2S powder, fabricating wafer‐scale highly crystalline Ag2S thin films. The thin films show stretchability due to the intrinsic ductility, sustaining the structural integrity at a tensile strain of 14.9%. Moreover, the fabricated Ag2S‐based resistive random access memory presents outstanding bipolar switching characteristics (Ion/Ioff ratio of ≈105, operational endurance of 100 cycles, and retention time >106 s) as well as excellent mechanical stretchability (no degradation of properties up to stretchability of 52%). Meanwhile, the device is highly durable under diverse chemical environments and temperatures from −196 to 300 °C, especially maintaining the properties for 168 h in 85% relative humidity and 85 °C. A self‐powered memory combined with motion sensors for use as a wearable healthcare monitoring system is demonstrated, offering the potential for designing high‐performance wearable electronics that are usable in daily life in a real‐world setting.
Solution‐processed synthesis of intrinsically stretchable Ag2S thin films for fabrication of self‐powered stretchable resistive memory devices is presented. The device exhibits excellent switching characteristics and mechanical stretchability (52%), and extremely high thermal and environmental durability (168 h in 85 °C/85% relative humidity). A self‐powered memory combined with motion sensors for use as a wearable healthcare monitoring system is demonstrated.
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