Elimination of charge trapping at defects is highly challenging for poly-crystalline organometal halide perovskites. Here, we report a new architecture for reinforcing the built-in electric field ( E ...in ) across the photoactive layer with a pair of strong electric dipole layers (EDLs). The paired EDLs significantly intensify the E in across the perovskite layer, resulting in suppressed charge trapping of photogenerated charges. As a result, our low-temperature processed P–I–N planar PeSC devices using the paired EDLs exhibit a higher power conversion efficiency ( η max ∼ 19.4%) and a smaller device-to-device variation with a standard deviation (S.D.) of 0.70%, which far surpass those ( η max ∼ 17.8%, S.D. ∼ 1.1%) of the devices with typical charge transport layers.
Although organometal halide perovskites (OHPs) have desirable photovoltaic properties, their photoelectrochemical (PEC) water‐splitting application for hydrogen production is limited by the ...instability originating from their intrinsic ionic defects and hygroscopic vulnerability. Herein, a highly efficient and stable OHP‐based photocathode achieved by a new zwitterion (L‐proline) passivation and a eutectic gallium indium alloy (EGaIn) encapsulation method is described. The zwitterion, which has both cations and anions, can simultaneously passivate both positively and negatively charged defects in OHPs. The resulting OHP photovoltaic cells with passivated shows an over 20% power conversion efficiency with an open‐circuit voltage of 1.13 V and a short‐circuit current of 22.13 mA cm−2. The EGaIn‐incorporated Ti foil provides complete encapsulation from the external environment while maintaining good transport of photogenerated charges from OHPs. Thus, these photocathodes exhibit a remarkable average photocurrent density of 21.2 mA cm−2 which has less than 5% current loss between PV cells and PEC cells. More admirably, the photocathode has the highest stability over 54 hours under continuous full sunlight illumination in a sulfuric acid electrolyte.
The simultaneous improvement of the photocurrent and stability in organometal halide perovskite (OHP) photocathodes is successfully achieved by introducing both L‐proline zwitterion additives in perovskite materials and a eutectic gallium indium alloy as a contact material for metal passivation. This approach can be an innovative technique for achieving high‐performance OHP‐based photoelectrochemical devices.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Metal‐organic framework (MOF) nanoparticles have recently emerged as a promising vehicle for drug delivery with high porosity and feasibility. However, employing a MOF‐based drug delivery system ...remains a challenge due to the difficulty in controlling interfaces of particles in a biological environment. In this paper, protein corona‐blocked Zr6‐based MOF (PCN‐224) nanoparticles are presented for targeted cancer therapy with high efficiency. The unmodified PCN‐224 surface is precoated with glutathione transferase (GST)‐fused targetable affibody (GST‐Afb) proteins via simple mixing conjugations instead of chemical modifications that can induce the impairment of proteins. GST‐Afb proteins are shown to stably protect the surface of PCN‐224 particles in a specific orientation with GST adsorbed onto the porous surface and the GST‐linked Afb posed outward, minimizing the unwanted interfacial interactions of particles with external biological proteins. The Afb‐directed cell‐specific targeting ability of particles and consequent induction of cell death is demonstrated both in vitro and in vivo by using two kinds of Afb, which targets the surface membrane receptor, human epidermal growth factor receptor 2 (HER2) or epidermal growth factor receptor (EGFR). This study provides insight into the way of regulating the protein‐adhesive surface of MOF nanoparticles and designing a more effective MOF‐hosted targeted delivery system.
Protein‐precoated metal‐organic framework (MOF) nanoparticles are prepared for targeted cancer therapy by using Zr6‐based MOF (PCN‐224), of which the surface is directly conjugated with glutathione transferase‐fused affibody proteins without chemical treatment. The resulting particles exhibited high stability against unwanted interactions with external biological proteins, being capable of target‐specific cellular/tumoral penetration for therapeutic outcomes with high efficiency.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Memristors have been considered as a leading candidate for a number of critical applications ranging from nonvolatile memory to non-Von Neumann computing systems. Feature extraction, which aims to ...transform input data from a high-dimensional space to a space with fewer dimensions, is an important technique widely used in machine learning and pattern recognition applications. Here, we experimentally demonstrate that memristor arrays can be used to perform principal component analysis, one of the most commonly used feature extraction techniques, through online, unsupervised learning. Using Sanger’s rule, that is, the generalized Hebbian algorithm, the principal components were obtained as the memristor conductances in the network after training. The network was then used to analyze sensory data from a standard breast cancer screening database with high classification success rate (97.1%).
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IJS, KILJ, NUK, PNG, UL, UM
Abstract Embryonic stem (ES) cells hold great potential as a renewable cell source for regenerative medicine and cell-based therapy. Despite the potential of ES cells, conventional stem cell culture ...methods do not enable the control of the microenvironment. A number of microscale engineering approaches have been recently developed to control the extracellular microenvironment and to direct embryonic stem cell fate. Here, we used engineered concave microwell arrays to regulate the size and shape of embryoid bodies (EBs)—cell aggregate intermediates derived from ES cells. Murine ES cells were aggregated within concave microwells, and their aggregate sizes were controlled by varying the microwell widths (200, 500, and 1000 μm). Differentiation of murine ES cells into three germ layers was assessed by analyzing gene expression. We found that ES cell-derived cardiogenesis and neurogenesis were strongly regulated by the EB size, showing that larger concave microwell arrays induced more neuronal and cardiomyocyte differentiation than did smaller microwell arrays. Therefore, this engineered concave microwell array could be a potentially useful tool for controlling ES cell behavior.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Three-dimensional (3D) printing technology is highly regarded in the field of dentistry. Three-dimensional printed resin restorations must undergo a washing process to remove residual resin on the ...surface after they have been manufactured. However, the effect of the use of different washing solutions and washing times on the biocompatibility of the resulting resin restorations is unclear. Therefore, we prepared 3D-printed denture teeth and crown and bridge resin, and then washed them with two washing solutions (isopropyl alcohol and tripropylene glycol monomethyl ether) using different time points (3, 5, 10, 15, 30, 60, and 90 min). After this, the cell viability, cytotoxicity, and status of human gingival fibroblasts were evaluated using confocal laser scanning. We also analyzed the flexural strength, flexural modulus, and surface SEM imaging. Increasing the washing time increased the cell viability and decreased the cytotoxicity (
< 0.001). Confocal laser scanning showed distinct differences in the morphology and number of fibroblasts. Increasing the washing time did not significantly affect the flexural strength and surface, but the flexural modulus of the 90 min washing group was 1.01 ± 0.21 GPa (mean ± standard deviation), which was lower than that of all the other groups and decreased as the washing time increased. This study confirmed that the washing time affected the biocompatibility and mechanical properties of 3D printed dental resins.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The design of a highly efficient and durable electrocatalyst for the production of hydrogen
via
electrochemical water splitting is highly desirable but remains a tremendous challenge. Though there ...has been some progress in basic media wherein the reaction is sluggish, here we report the synthesis of a new hybrid catalyst comprising Cu and Rh elements as bimetallic single atoms (SAs) and nanoparticles (NPs) on a N-doped graphene (G
N
) surface (
1
: Cu/Rh(SAs) + Cu
2
Rh(NPs)/G
N
) that works remarkably fast for the hydrogen evolution reaction (HER) in acidic media. Benefiting from the large specific electrochemical surface area, low charge transfer resistance and combined synergistic effect of bimetallic SAs and NPs, the as-obtained catalyst
1
requires an overpotential as low as 8 mV (commercial Pt/C requires 14 mV) in 0.5 M H
2
SO
4
solution to deliver a benchmark current density of 10 mA cm
−2
. It maintains constant current densities (∼10-100 mA cm
−2
) at both low and high overpotentials during the 500 h continuous HER electrolysis chronoamperometry test. Moreover,
1
exhibits a low Tafel slope (27 mV dec
−1
), a high turnover frequency and mass activity (1.237 s
−1
and 2.314 A mg
Rh
−1
) which are higher than those of Pt/C (0.329 s
−1
and 0.326 A mg
Pt
−1
) and a constant H
2
production rate with high faradaic efficiency (98-99%). Electrochemical experiments in conjunction with density functional theory (DFT) calculations reveal that the combination of Rh and Cu atoms on the G
N
surface not only maximizes the rates of H
+
adsorption on the electrode surface (due to the high surface area of
1
) but also optimizes the hydrogen adsorption free energy (Δ
G
H*
) close to zero (0.01 eV), improving the intrinsic catalytic activity for the HER.
This article reports the synthesis of bimetallic Cu/Rh single atoms and Cu
2
Rh nanoparticles on N-doped graphene (Cu/Rh(SAs) + Cu
2
Rh(NPs)/G
N
) for efficient and durable hydrogen fuel production from acidic water.
Chrysanthemum zawadskii var. latilobum (CZ) has been used as a traditional medicine in Asian countries for the treatment of inflammatory diseases. Recently, CZ extract was shown to inhibit ...differentiation of osteoclasts and provide protection against rheumatoid arthritis. The aim of this study was to investigate the molecular mechanisms of BST106, the ethanol extract of CZ, for cartilage protection in monosodium iodoacetate (MIA)-induced osteoarthritis (OA), particularly focusing on apoptosis and autophagy. BST106 (50, 100, and 200 mg/kg) was orally administered once daily to MIA-induced OA rats. Swelling, limping, roentgenography, and histomorphological changes were assessed 28 d after MIA injection. Biochemical parameters for matrix metalloproteinase (MMP), apoptosis, and autophagy were also assessed. BST106 ameliorated the severity of swelling and limping after MIA injection. Roentgenographic and histomorphological examinations revealed that BST106 reduced MIA-induced cartilage damage. BST106 decreased MIA-induced increases in MMP-2 and MMP-13 mRNA levels. Increased levels of serum cartilage oligomeric matrix protein and glycosaminoglycan release were attenuated by BST106. Furthermore, BST106 suppressed the protein expression of proapoptotic molecules and increased the protein expression of autophagosome- and autolysosome-related molecules. These findings indicate that BST106 protects against OA-induced cartilage damage by inhibition of the apoptotic pathway and restoration of impaired autophagic flux.
Precise remote evaluation of both suicide risk and psychiatric disorders is critical for suicide prevention as well as for psychiatric well-being. Using questionnaires is an alternative to ...labor-intensive diagnostic interviews in a large general population, but previous models for predicting suicide attempts suffered from low sensitivity. We developed and validated a deep graph neural network model that increased the prediction sensitivity of suicide risk in young adults (n = 17,482 for training; n = 14,238 for testing) using multi-dimensional questionnaires and suicidal ideation within 2 weeks as the prediction target. The best model achieved a sensitivity of 76.3%, specificity of 83.4%, and an area under curve of 0.878 (95% confidence interval, 0.855-0.899). We demonstrated that multi-dimensional deep features covering depression, anxiety, resilience, self-esteem, and clinico-demographic information contribute to the prediction of suicidal ideation. Our model might be useful for the remote evaluation of suicide risk in the general population of young adults for specific situations such as the COVID-19 pandemic.
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Mitochondria are organelles that are readily susceptible to temperature elevation. We selectively delivered a coumarin-based fluorescent iron oxide nanoparticle, Mito-CIO, to the mitochondria. Upon ...740 nm laser irradiation, the intracellular temperature of HeLa cells was elevated by 2.1 °C within 5 min when using Mito-CIO, and the treatment resulted in better hyperthermia and a more elevated cytotoxicity than HeLa cells treated with coumarin iron oxide (CIO), which was missing the mitochondrial targeting unit. We further confirmed these results in a tumor xenograft mouse model. To our knowledge, this is the first report of a near-infrared laser irradiation-induced hyperthermic particle targeted to mitochondria, enhancing the cytotoxicity in cancer cells. Our present work therefore may open a new direction in the development of photothermal therapeutics.
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