In this paper, a color image encryption is proposed based on the dynamic DNA and the 4-D memristive hyper-chaos. First, chaotic matrices are generated from the 4-D memristive hyper-chaos by using the plain image, the salt key, and control parameters. Second, the dynamic encoding process is performed on three components of the plain image to obtain three DNA matrices. Third, to enhance both the security and robustness of encrypted image, dynamic confusion and diffusion are applied to the encoded DNA matrices. Finally, the encrypted image is generated by DNA decoding and components combining. The main feature of our proposed algorithm is that dynamic DNA mechanism based on hyper-chaos is performed on the processes of encoding, confusion, and diffusion. Simulation results and security analysis further demonstrate that it has a strong resistance against various attacks and outperforms other methods in the literature. INDEX TERMS Dynamic DNA, color image, encryption, memristive hyper-chaos.

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Sekundäre Amine können es auch! Die erfolgreiche katalytische asymmetrische Insertion von α‐Diazoestern in die N‐H‐Bindung unterschiedlich substituierter Amine wird vorgestellt (siehe Schema; M.S.=Molekularsieb). Mit einer Vielzahl an Substraten wurden ausgezeichnete Enantioselektivitäten (bis 98 % ee) und hohe Ausbeuten (bis 99 %) unter milden Reaktionsbedingungen erhalten.

Transforming growth factor beta (TGFβ) signaling plays an important role during osteogenesis. However, most research in this area focuses on cortical and trabecular bone, whereas alveolar bone is largely overlooked. To address the role of TGFβR2 (the key receptor for TGFβ signaling) during postnatal alveolar bone development, we conditionally deleted Tgfβr2 in early mesenchymal progenitors by crossing Gli1-CreERT2; Tgfβr2flox/flox; R26RtdTomato mice (named early cKO) or in osteoblasts by crossing 3.2kb Col1-CreERT2; Tgfβr2flox/flox; R26RtdTomato mice (named late cKO). Both cKO lines were induced at postnatal day 5 (P5) and mice were harvested at P28. Compared to the control littermates, early cKO mice exhibited significant reduction in alveolar bone mass and bone mineral density, with drastic defects in the periodontal ligament (PDL); conversely, the late cKO mice displayed very minor changes in alveolar bone. Mechanism studies showed a significant reduction in PCNA+ PDL cell numbers and OSX+ alveolar bone cell numbers, as well as disorganized PDL fibers with a great reduction in periostin (the most abundant extracellular matrix protein) on both mRNA and protein levels. We also showed a drastic reduction in β-catenin in the early cKO PDL and a great increase in SOST (a potent inhibitor of Wnt signaling). Based on these findings, we conclude that TGFβ signaling plays critical roles during early alveolar bone formation via the promotion of PDL mesenchymal progenitor proliferation and differentiation mechanisms.

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Osteoporosis is a prevalent bone disorder characterized by bone mass reduction and deterioration of bone microarchitecture leading to bone fragility and fracture risk. In recent decades, knowledge regarding the etiological mechanisms emphasizes that inflammation, oxidative stress and senescence of bone cells contribute to the development of osteoporosis. Studies have demonstrated that heme oxygenase 1 (HO-1), an inducible enzyme catalyzing heme degradation, exhibits anti-inflammatory, anti-oxidative stress and anti-apoptosis properties. Emerging evidence has revealed that HO-1 is critical in the maintenance of bone homeostasis, making HO-1 a potential target for osteoporosis treatment. In this Review, we aim to provide an introduction to current knowledge of HO-1 biology and its regulation, focusing specifically on its roles in bone homeostasis and osteoporosis. We also examine the potential of HO-1-based pharmacological therapeutics for osteoporosis and issues faced during clinical translation.

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