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Objective: To investigate the effects and mechanisms of olfactory three-needle (OTN) electroacupuncture (EA) stimulation of the olfactory system on cognitive dysfunction, synaptic plasticity, and the gut microbiota in senescence-accelerated mouse prone 8 (SAMP8) mice. Methods: Thirty-six SAMP8 mice were randomly divided into the SAMP8 (P8), SAMP8+OTN (P8-OT), and SAMP8+nerve transection+OTN (P8-N-OT) groups according to a random number table (n=12 per group), and 12 accelerated senescence-resistant (SAMR1) mice were used as the control (R1) group. EA was performed at the Yintang (GV 29) and bilateral Yingxiang (LI 20) acupoints of SAMP8 mice for 4 weeks. The Morris water maze test, transmission electron microscopy, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining, Nissl staining, Golgi staining, Western blot, and 16S rRNA sequencing were performed, respectively. Results: Compared with the P8 group, OTN improved the cognitive behavior of SAMP8 mice, inhibited neuronal apoptosis, increased neuronal activity, and attenuated hippocampal synaptic dysfunction (P<0.05 or P<0.01). Moreover, the expression levels of synaptic plasticity-related proteins N-methyl-D-aspartate receptor 1 (NMDAR1), NMDAR2B, synaptophysin (SYN), and postsynaptic density protein-95 (PSD95) in hippocampus were increased by OTN treatment (P<0.05 or P<0.01). Furthermore, OTN greatly enhanced the brain-derived neurotrophic factor (BDNF)/cAMP-response element binding (CREB) signaling and phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling compared with the P8 group (P<0.05 or P<0.01). However, the neuroprotective effect of OTN was attenuated by olfactory nerve truncation. Compared with the P8 group, OTN had a very limited effect on the fecal microbial structure and composition of SAMP8 mice, while specifically increased the genera Oscillospira and Sutterella (P<0.05). Interestingly, the P8-N-OT group showed an abnormal fecal microbiota with higher microbial α-diversity, Firmicutes/Bacteroidetes ratio and pathogenic bacteria (P<0.05 or P<0.01). Conclusions: OTN improved cognitive deficits and hippocampal synaptic plasticity by stimulating the olfactory nerve and activating the BDNF/CREB and PI3K/AKT/mTOR signaling pathways. Although the gut microbiota was not the main therapeutic target of OTN for Alzheimer's disease, the olfactory nerve was essential to maintain the homeostasis of gut microbiota. [ABSTRACT FROM AUTHOR]

Structural and electronic properties of PbnAgn (n=2-12) clusters were investigated by density functional theory with generalized gradient approximation at BLYP level in DMol3 program package. The optimized bimetallic PbnAgn (n=2-12) clusters were viewed as the initial structures, then, those were calculated by ab initio molecular dynamics (AIMD) to search possible global minimum energy structures of PbnAgn clusters, finally, the ground state structures of PbnAgn (n=2-12) clusters were achieved. According to the structural evolution of lowest energy structures, Ag atoms prefer gather in the central sites while Pb atoms prefer external positions in PbnAgn (n=2-12) clusters, which is in excellent agreement with experimental results from literature and the application in metallurgy. The average binding energies, HOMO-LUMO gaps, vertical ionization potentials, vertical electron affinities, chemical hardness η, HOMO orbits, LUMO orbits and density of states of PbnAgn (n=2-12) clusters were calculated. The results indicate that the values of HOMO-LUMO gaps, vertical ionization potentials, vertical electron affinities and chemical hardness η show obvious odd-even oscillations when n≤5, PbnAgn (n=2-12) clusters become less chemically stable and show insulator-to-metal transition with the variation of cluster size n, PbnAgn (n≥9) cluster are good candidates to study the properties of PbAg alloys. Those can be well explained by the density of states (DOS) distributions of Pb atoms and Ag atoms between-0.5 Ha and 0.25 Ha in PbnAgn (n=2-12) clusters. [ABSTRACT FROM AUTHOR]

The structural, relative stable and electronic properties of PbSn (n = 2-12) alloy clusters were systematically studied using density functional theory. The isomers of PbSn alloy clusters were generated and determined by ab initio molecular dynamics. By comparing the calculated parameters of Pb dimer and Sn dimers with the parameters from experiments, our calculations are reasonable. With the lowest-energy structures for PbSn clusters, the average binding energies, fragmentation energies, second- order energy differences, vertical ionization potentials, vertical electron affinities, HOMO-LUMO gaps, and density of states were calculated and analyzed. The results indicate that the Sn atoms have a tendency to bond together, the average binding energies tend to be stable up to n = 8, PbSn cluster is a good candidate to calculate the molecular interaction energy parameter in Wilson equation, the clusters become less chemical stable and show an insulator-to-metallic transition, 3, 6, 8 and 11 are magic numbers of PbSn (n = 2-12) clusters, the charges always transfer from Sn atoms to Pb atoms in PbSn clusters except for PbSn cluster, and density of states of PbSn clusters becoming continuous and shifting toward negative with the increasing size n. [ABSTRACT FROM AUTHOR]

Cystic adventitial disease (CAD) of the popliteal artery is a rare vascular disorder in which a mucin-containing cyst develops in the adventitial layer of the artery. We report two such cases, each of which was treated differently. The first case was of a 49-year-old man, treated by excision of the involved arterial segment and interposition of an autologous saphenous vein graft. The second case was of a 36-year-old man, treated by local excision of the affected arterial segment and interposition with prosthetic bypass grafting. Both patients presented with rapidly progressing intermittent claudication of the lower extremities, but without remarkable evidence of atherosclerotic disease. Physical examination revealed diminished or absent popliteal, posterior tibial and dorsalis pedis pulses in the lower extremities. Color Doppler ultrasound of the popliteal artery revealed hypoechoic cystic lesions surrounding the vessel, and popliteal arterial stenosis, in both patients. Surgery resulted in immediate improvement of the arterial pulse distal to the lesion. Both patients recovered uneventfully. Thus, resection of the involved artery segment and interposition bypass grafting, using either patient or prosthetic veins, offers favorable results for CAD of the popliteal artery. [ABSTRACT FROM AUTHOR]