ObjectiveTo explore the mechanisms through which Si Junzitang （SJZD） ameliorates Alzheimer's disease （AD） induced by scopolamine （SCOP） in mice and the PC12 cell model induced by H₂O₂ based on the Kelch-like ECH-associated protein 1 （Keap1）/nuclear factor erythroid 2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1） signaling pathway. MethodsIn the animal experiments， an AD model was established in mice by intraperitoneal injection of SCOP （3 mg·kg^-1）. Morris water maze and open field tests （OFT） were conducted to assess learning and memory abilities. Hematoxylin-eosin （HE） staining and Nissl staining were performed to observe pathological changes in neurons. Immunofluorescence was used to detect amyloid β-protein_1-42 （Aβ_1-42） expression， and immunohistochemistry was employed to detect phosphorylated （p）-Tau expression. Transmission electron microscopy （TEM） was employed to observe ultrastructural changes in hippocampal neurons and synapses. Biochemical methods were used to measure the levels of acetylcholine （ACh）， acetylcholinesterase （AChE）， superoxide dismutase （SOD）， malondialdehyde （MDA）， catalase （CAT）， and lactate dehydrogenase （LDH）. Real-time PCR and Western blot were employed to measure the mRNA and protein levels of molecules in the Keap1/Nrf2/HO-1 pathway in the hippocampus. In the cell experiments， a PC12 cell model of oxidative damage model was established with H₂O₂. Cell count kit-8 （CCK-8） assays and flow cytometry were adopted to measure cell viability and apoptosis rates， and Western blot was employed to quantify the expression levels of proteins in the Keap1/Nrf2/HO-1 pathway. ResultsThe animal experiments showed that compared with the model group， the SJZD and donepezil groups showed shortened escape latency （P<0.01）， increased time in the target quadrant and platform crossings， and increased movement distance and duration in the central area of the open field （P<0.05， P<0.01）. HE and Nissl staining showed more organized neurons and increased Nissl bodies in the drug intervention groups （P<0.05， P<0.01）， and the Aβ_1-42 and p-Tau expression levels were downregulated （P<0.05， P<0.01）. TEM revealed reduced ultrastructural damage in hippocampal neurons and synapses in the drug intervention groups. In addition， the drug intervention groups showed declined levels of MDA， LDH， and AChE （P<0.05， P<0.01）， elevated levels of SOD， CAT， and ACh （P<0.05， P<0.01）， reduced Keap1 expression and increased Nrf2， HO-1， and NQO1 expression in the hippocampus （P<0.05， P<0.01）. The cell experiments showed that compared with the model group， the SJZD-containing serum increased the cell viability （P<0.05， P<0.01）， and decreased total apoptosis rates （P<0.05， P<0.01）. The drug intervention groups showed upregulated protein levels of Nrf2 and HO-1 and downregulated protein level of Keap1 （P<0.05， P<0.01）. ConclusionSJZD demonstrates protective effects against SCOP-induced AD in mice and H₂O₂-induced damage in PC12 cells through antioxidant mechanisms mediated by the Keap1/Nrf2/HO-1 pathway.

Objective To assay the contents of acetaminophen with ultra high-performance liquid chromatography (UHPLC) method in the sustained-release tablets radiated by Gamma ray. Methods Acetaminophen sustained-release tablets were radiated by ⁶⁰Co. UHPLC equipped with the Shim-pack GISS-C₁₈（2.1 mm×50 mm, 1.9 μm）was used for the assay. The mobile phase was methanol-0.05 % ammonium acetate solution (15∶85). The flow rate was 0.3 ml/min with the detection wavelength at 245 nm. Results The acetaminophen showed good linear relationship within the range of 20-100 μg/ml (r=0.999 4). The RSD values of repeatability was 0.9 %. The average recovery was 97.9 %-104.9 %. Acetaminophen content was 96.2 %, 92.2 %, 91.8 %, 83.9 % at 0, 8, 50 and 80 kGy radiation, respectively. Conclusion This method is speedy and accurate. It can be used to assay the content of acetaminophen in the sustained-release tablets after radiation. The content of acetaminophen decreased after radiation.

The most common indications for total elbow arthroplasty (TEA) are rheumatoid arthritis, osteoarthritis, and post-traumatic arthritis. However, with the rapid development of the prosthesis and surgical techniques, the indications of TEA have been expanded to post-traumatic instability, failure of internal fixation, and acute comminuted distal humeral fractures in elderly patients. The most common complications of the classic Bryan-Morrey approach are postoperative ulnar nerve symptoms and weakness of the triceps muscle. Although the triceps-sparing approach enters the elbow joint through both sides of the triceps and retains the triceps brachii, it adds the operation difficulty and there still exist problems regarding postoperative ulnar nerve symptoms, extensive subcutaneous dissection, and large amount of drainage. In September 2018, Professor O'Driscoll introduced his modified small tongue-shaped flap approach, named as Diamond-Pop approach, but it has not been reported yet in recent literatures. The authors conducted a retrospective case series study to evaluate the clinical outcomes of 20 patients with elbow trauma or arthritis treated by TEA using this approach in Beijing Jishuitan Hospital from September 2018 to September 2019.