PSS). This sensor, which can detect small strains on human skin, was created using environmentally benign water-based solution processing. We attributed the tunability of strain sensitivity (i.e., gauge factor), stability, and optical transparency to enhanced formation of percolating networks between conductive SWCNTs and PEDOT phases at interfaces in the stacked PU-PEDOT:PSS/SWCNT/PU-PEDOT:PSS structure. The mechanical stability, high stretchability of up to 100%, optical transparency of 62%, and gauge factor of 62 suggested that when attached to the skin of the face, this sensor would be able to detect small strains induced by emotional expressions such as laughing and crying, as well as eye movement, and we confirmed this experimentally.

A new kind of flexible strain sensor based on a reduced graphene oxide field‐effect transistor (rGO FET) with ultrasensitivity, stability, and repeatability for the detection of tensile and compressive strains is demonstrated. The novelty of the rGO FET strain sensor is the incorporation of a rGO channel as a sensing layer in which the electrical resistance can be greatly modified upon application of an extremely low level of strain resulting in an intrinsically amplified sensing signal. The rGO FET device is ultrasensitive to extremely low strain levels, as low as 0.02%. Due to weak coupling between adjacent nanosheets, therefore, upon applying small levels of strain into the rGO thin film, a modulation of the internanosheet resistance (Rinter) is expected, inducing a large change in the transconductance of the rGO FET. Using a simple printing and self‐assembly process, the facile fabrication of an rGO FET array over a large area is also demonstrated. In addition, the device can detect small and rapid physical movements of the human body.

Objective. To investigate whether the reduction of discoidin domain receptor 2 (DDR-2), a cell membrane tyrosine kinase receptor for native type II collagen, attenuates the progression of articular cartilage degeneration in mouse models of osteoarthritis (OA).Methods. mice were subjected to microsurgical destabilization of the medial meniscus. Conditions of the articular cartilage from the knee joints of the double-heterozygous mutant and surgically treated mice were examined by histology, evaluated using a modified Mankin scoring system, and characterized by immunohistochemistry.Results. The rate of progressive degeneration in knee joints was dramatically reduced in the doubleheterozygous mutant mice compared with that in the type XI collagen-deficient mice. The progression in the double-heterozygous mutant mice was delayed by ϳ6 months. Following surgical destabilization of the medial meniscus, the progressive degeneration toward OA was dramatically delayed in the Ddr2 ؉/-mice compared with that in their wild-type littermates. The articular cartilage damage present in the knee joints of the mice was directly correlated with the expression profiles of DDR-2 and matrix metalloproteinase 13.Conclusion. Reduction of DDR-2 expression attenuates the articular cartilage degeneration of knee joints induced either by type XI collagen deficiency or by surgical destabilization of the medial meniscus.

A reduced graphene oxide field‐effect transistor (R‐GO FET) device has a uniform self‐assembled and networked channel of R‐GO nanosheets that are highly responsive to physical stimuli such as temperature variations and infrared irradiation. The charge‐transport mechanisms of the networked R‐GO thin film include charge tunneling through the nanosheet junction and charge‐hopping transport. Under a thermal or infrared (IR) stimulus, the charge carriers generated by thermal or IR activation contribute to changes in the charge transport inside the networked R‐GO thin film.