Osteoarthritis (OA) is the most common form of arthritis. It is characterized by progressive destruction of articular cartilage and the development of chronic pain and constitutes a considerable ...socioeconomic burden. Currently, pharmacological treatments mostly aim to relieve the OA symptoms associated with inflammation and pain. However, with increasing understanding of OA pathology, several potential therapeutic targets have been identified, enabling the development of disease-modifying OA drugs (DMOADs). By targeting inflammatory cytokines, matrix-degrading enzymes, the Wnt pathway, and OA-associated pain, DMOADs successfully modulate the degenerative changes in osteoarthritic cartilage. Moreover, regenerative approaches aim to counterbalance the loss of cartilage matrix by stimulating chondrogenesis in endogenous stem cells and matrix anabolism in chondrocytes. Emerging strategies include the development of senolytic drugs or RNA therapeutics to eliminate the cellular or molecular sources of factors driving OA. This review describes the current developmental status of DMOADs and the corresponding results from preclinical and clinical trials and discusses the potential of emerging therapeutic approaches to treat OA.
An ultrahigh performance MoS2 photodetector with high photoresponsivity (1.94 × 106 A W–1) and detectivity (1.29 × 1012 Jones) under 520 nm and 4.63 pW laser exposure is demonstrated. This ...photodetector is based on a methyl‐ammonium lead halide perovskite/MoS2 hybrid structure with (3‐aminopropyl)triethoxysilane doping. The performance degradation caused by moisture is also minimized down to 20% by adopting a new encapsulation bilayer of octadecyltrichlorosilane/polymethyl methacrylate.
Abstract
Brain-inspired parallel computing, which is typically performed using a hardware neural-network platform consisting of numerous artificial synapses, is a promising technology for effectively ...handling large amounts of informational data. However, the reported nonlinear and asymmetric conductance-update characteristics of artificial synapses prevent a hardware neural-network from delivering the same high-level training and inference accuracies as those delivered by a software neural-network. Here, we developed an artificial van-der-Waals hybrid synapse that features linear and symmetric conductance-update characteristics. Tungsten diselenide and molybdenum disulfide channels were used selectively to potentiate and depress conductance. Subsequently, via training and inference simulation, we demonstrated the feasibility of our hybrid synapse toward a hardware neural-network and also delivered high recognition rates that were comparable to those delivered using a software neural-network. This simulation involving the use of acoustic patterns was performed with a neural network that was theoretically formed with the characteristics of the hybrid synapses.
A high‐performance ReS2‐based thin‐film transistor and photodetector with high on/off‐current ratio (104), high mobility (7.6 cm2 V−1 s−1), high photoresponsivity (2.5 × 107 A W−1), and fast temporal ...response (rising and decaying time of 670 ms and 5.6 s, respectively) through O2 plasma treatment is reported.
Abstract
It is important to understand the dynamical processes that cause heat waves at regional scales. This study examined the physical mechanism that was responsible for a heat wave in South Korea ...in August 2016. Unlike previous August heat waves over the Korean Peninsula, the intensity of the geopotential height over the Kamchatka Peninsula in August 2016 was the strongest since 1979, which acted as an atmospheric blocking in the downstream region of the Korean Peninsula. Therefore, the anomalous high geopotential height in Mongolia, where the surface temperature was quite high, was observed persistently in August 2016. This anomalous high in Mongolia induced northerly winds with warm temperatures onto the Korean Peninsula, which contributed to a heat wave in August 2016. We further showed that the anomalous high geopotential height over the Kamchatka Peninsula in August 2016 was triggered by strong convection in the western-to-central subtropical Pacific through atmospheric teleconnections, which was quite different from a typical heat wave over the Korean Peninsula, in which convective forcing around the South China Sea is strong. This implies that convective forcing in the subtropical Pacific should also be monitored to predict heat wave events in East Asia, including South Korea. On the other hand, the zonal wave train associated with the circumglobal teleconnection pattern is also associated with the anomalous high geopotential height around Mongolia and the Kamchatka Peninsula, which may have contributed to the heat wave in August 2016.
Aging and mechanical overload are prominent risk factors for osteoarthritis (OA), which lead to an imbalance in redox homeostasis. The resulting state of oxidative stress drives the pathological ...transition of chondrocytes during OA development. However, the specific molecular pathways involved in disrupting chondrocyte redox homeostasis remain unclear. Here, we show that selenophosphate synthetase 1 (SEPHS1) expression is downregulated in human and mouse OA cartilage. SEPHS1 downregulation impairs the cellular capacity to synthesize a class of selenoproteins with oxidoreductase functions in chondrocytes, thereby elevating the level of reactive oxygen species (ROS) and facilitating chondrocyte senescence. Cartilage-specific Sephs1 knockout in adult mice causes aging-associated OA, and augments post-traumatic OA, which is rescued by supplementation of N-acetylcysteine (NAC). Selenium-deficient feeding and Sephs1 knockout have synergistic effects in exacerbating OA pathogenesis in mice. Therefore, we propose that SEPHS1 is an essential regulator of selenium metabolism and redox homeostasis, and its dysregulation governs the progression of OA.
Abstract
The recent reports of various photodetectors based on molybdenum disulfide (MoS
2
) field effect transistors showed that it was difficult to obtain optoelectronic performances in the broad ...detection range visible–infrared (IR) applicable to various fields. Here, by forming a mono-/multi-layer nano-bridge multi-heterojunction structure (more than > 300 junctions with 25 nm intervals) through the selective layer control of multi-layer MoS
2
, a photodetector with ultrasensitive optoelectronic performances in a broad spectral range (photoresponsivity of 2.67 × 10
6
A/W at
λ
= 520 nm and 1.65 × 10
4
A/W at
λ
= 1064 nm) superior to the previously reported MoS
2
-based photodetectors could be successfully fabricated. The nano-bridge multi-heterojunction is believed to be an important device technology that can be applied to broadband light sensing, highly sensitive fluorescence imaging, ultrasensitive biomedical diagnostics, and ultrafast optoelectronic integrated circuits through the formation of a nanoscale serial multi-heterojunction, just by adding a selective layer control process.
The practical application of the Zn‐metal anode for aqueous batteries is greatly restricted by catastrophic dendrite growth, intricate hydrogen evolution, and parasitic surface passivation. Herein, a ...polyanionic hydrogel film is introduced as a protective layer on the Zn anode with the assistance of a silane coupling agent (denoted as Zn–SHn). The hydrogel framework with zincophilic –SO3− functional groups uniformizes the zinc ions flux and transport. Furthermore, such a hydrogel layer chemically bonded on the Zn surface possesses an anti‐catalysis effect, which effectively suppresses both the hydrogen evolution reaction and formation of Zn dendrites. As a result, stable and reversible Zn stripping/plating at various currents and capacities is achieved. A full cell by pairing the Zn–SHn anode with a NaV3O8·1.5 H2O cathode shows a capacity of around 176 mAh g−1 with a retention around 67% over 4000 cycles at 10 A g−1. This polyanionic hydrogel film protection strategy paves a new way for future Zn‐anode design and safe aqueous batteries construction.
A unique polyanionic hydrogel is employed as an artificial protective layer for reversible Zn‐metal anodes. The polyanions in the hydrogel framework facilitate a homogeneous zinc‐ion flux, and the Zn–O bonding strengthens the interface and suppresses surface corrosion and irregular Zn dendrites growth. This strategy could apply also to other aqueous metal batteries.
Most doping research into transition metal dichalcogenides (TMDs) has been mainly focused on the improvement of electronic device performance. Here, the effect of self‐assembled monolayer (SAM)‐based ...doping on the performance of WSe2‐ and MoS2‐based transistors and photodetectors is investigated. The achieved doping concentrations are ≈1.4 × 1011 for octadecyltrichlorosilane (OTS) p‐doping and ≈1011 for aminopropyltriethoxysilane (APTES) n‐doping (nondegenerate). Using this SAM doping technique, the field‐effect mobility is increased from 32.58 to 168.9 cm2 V−1 s in OTS/WSe2 transistors and from 28.75 to 142.2 cm2 V−1 s in APTES/MoS2 transistors. For the photodetectors, the responsivity is improved by a factor of ≈28.2 (from 517.2 to 1.45 × 104 A W−1) in the OTS/WSe2 devices and by a factor of ≈26.4 (from 219 to 5.75 × 103 A W−1) in the APTES/MoS2 devices. The enhanced photoresponsivity values are much higher than that of the previously reported TMD photodetectors. The detectivity enhancement is ≈26.6‐fold in the OTS/WSe2 devices and ≈24.5‐fold in the APTES/MoS2 devices and is caused by the increased photocurrent and maintained dark current after doping. The optoelectronic performance is also investigated with different optical powers and the air‐exposure times. This doping study performed on TMD devices will play a significant role for optimizing the performance of future TMD‐based electronic/optoelectronic applications.
High‐performance transition metal dichalcogenides (TMD) photodetectors are enhanced by self‐assembled monolayer (SAM) doping. The photoresponsivity of WSe2 and MoS2 photodetectors is improved by a factor of ≈28.2 (with OTS p‐doping) and ≈26.4 (with APTES n‐doping), respectively. These improvements are attributed to the enhancement of TMD optical properties by SAM doping and this is also investigated in detail through photoluminescence analysis.
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