No abstract

Lymphatic enhancer factor 1 (Lef1) and distal-less homeobox 3 (Dlx3) are the transcription factors involved in regulating hair follicle development in mice, goats, and other animals. Their deletion can lead to hair follicle deficiency. In this study, hematoxylin–eosin staining (HE), real-time quantitative PCR (RT-qPCR), immunohistochemistry, and immunofluorescence were used to analyze the expression, location, and biological functions of Lef1 and Dlx3 in the lateral skin of Gansu Alpine Merino aged 1, 30, 60, and 90 days. The results revealed that the number of hair follicles decreased with age and was significantly higher at 1 day than in the other three age groups (p < 0.05). The mRNA levels of Lef1 and Dlx3 in the skin of 30-day old Gansu Alpine Merino were significantly higher than those in the other three age groups (p < 0.05). Protein expression of Lef1 and Dlx3 was lowest at 1 day (p < 0.05) and peaked at 60 days. Lef1 and Dlx3 exhibited a high density and strong positive expression in the dermal papillae; additionally, Dlx3 exhibited a high density and strong positive expression in the inner and outer root sheaths. Collectively, Lef1 and Dlx3 may facilitate the maturation of secondary hair follicles, which is mainly achieved through the dermal papillae and inner and outer root sheaths.

No abstract

Multi-level memory can greatly improve information density, so it has been widely studied. In this study, a carbazole-based donor-acceptor polymer poly[2,7-9-(heptadecan-9-yl)-9H-carbazole-alt-7H-benzimidazo[2,1a]benz[de]isoquinolin-7-one] (PCz-BB) is synthesized, which exhibits flash-type ternary memory behavior. Further, CdS nanoparticles (NPs) are embedded into the prepared polymer to enhance the storage performance. The current-voltage (I-V) characteristics of memory devices based on PCz-BB:CdS composites and the effect of the embedding ratio of CdS NPs on the memory devices are studied. It is verified that the ON2/ON1/OFF current ratios of the devices at low CdS embedding concentrations are improved, and the threshold voltages are also reduced. The memory device based on the optimal embedding concentration (3 wt% CdS) exhibits a high ON2/ON1/OFF current ratio of 18631:72:1, a low threshold voltage of −0.40/−1.20 V, and excellent stability. The mechanism of resistive switching is explained by the theory of charge traps and conductive filaments. This work provides a new avenue for high-performance multi-level organic electrical storage materials.

For nonvolatile memory devices, the design and synthesis of their substrate materials are very important. Due to the versatility and large-area fabrication of the low-temperature spin coating process, organic/inorganic nanomaterials as active layers of memory devices have been deeply studied. Inorganic nanoparticles can engage in interactions with polymers via external voltage. WS 2 NPs have a large specific surface area and good conductivity. They can be used as the charge trap center in the active layer, which is conducive to the charge transfer in the active layer. Poly[2,7-9-(9-heptadecanyl)-9Hcarbazole-co-benzo [4,5] imidazole[2,1-α] isoindol-11-one] (PIIO) was synthesized via the Suzuki coupling reaction. ITO/PIIO/Al and ITO/PIIO:WS 2 NP/ Al devices were prepared by the spin coating method and vacuum evaporation technology. All devices showed tristable switching behavior. The influence of the WS 2 mass fraction on memory performance was studied. The device composite with 6 wt % WS 2 NPs showed the best storage features. The OFF/ON1/ON2 current ratio was 1: 1.11 × 10 1 : 2.03 × 10 4 , and the threshold voltage V th1 /V th2 was −0.60 V/−1.05 V. The device is steady for 12,000 s in three states−high-resistance state (HRS), intermediate state (IRS), and low-resistance state (LRS). After reading 3500 times, the switch-state current displayed no obvious attenuation. This work shows that the polymer and its composites have broad prospects in next-generation nonvolatile storage.