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To solve the problems of multi-behavior recommendation research such as failing to comprehensively capture multi-behavior interaction features and ignoring a large number of noise labels present in implicit feedback data such as clicks, a multi-behavior multi-task recommendation algorithm integrating self-supervised Learning enhancement is proposed. First, the multi-behavior interaction features are sensed from both behavior influence weights and behavior implicit semantics, and the features are fused into the embedding propagation process to enhance the expressiveness of node embeddings. Then, the self-supervised learning assistance task is constructed to avoid model overfitting to noisy labels through multi-view comparison learning. Finally, the supervised multi-behavior recommendation task and the self-supervised learning assistance task are combined and a multi-objective loss optimization strategy is used for multitask learning to obtain more accurate user and item embeddings. The experimental analysis shows that the algorithm has a certain improvement in both HR and NDCG indexes compared with the comparison algorithm, which proves the effectiveness and superiority of the algorithm. [ABSTRACT FROM AUTHOR]

BACKGROUND: Metformin has been shown to hold anti-inflammatory effect, inhibit the expression of interleukin1β and tumor necrosis factor α, and affect bone metabolism by activating AMPK signaling pathway. However, the effects of metformin on cartilage and subchondral bone remain obscure. OBJECTIVE: To investigate the effects of metformin on articular cartilage injury and pathological changes of subchondral bone in early osteoarthritis in mice. METHODS: C57 mice, SPF grade and postnatal 3 day neonate mice (used for primary chondrocyte culture) were provided by Laboratory Animal Center of Southern Medical University, and the experimental protocol was approved by the Animal Ethics Committee of the Third Affiliated Hospital of Southern Medical University. (1) Modeling: Eight-week-old C57 male mice were randomly divided into control and experimental groups. The traumatic osteoarthritis model was established in all mice, the experimental group was treated with 200 mg/(kg•d) metformin by intragastric administration, and the control group the same volume of normal saline. The knee joint specimens were taken for histological analysis after 5 weeks of treatment. Safranin O fast green staining and Osteoarthritis Research Society International score were used to evaluate the damage of articular cartilage and the degree of subchondral osteosclerosis. The expression of matrix metalloproteinase 13, collagen type II, Runt-related transcription factor 2 and osteocalcin protein was detected by immunohistochemical staining. (2) Cytological experiment: Primary chondrocytes were isolated from neonate mice born within three days, induced by 10 μg/L interleukin 1β, and co-cultured with metformin (5, 10 mmol/L). The expression levels of collagen type II, Runt-related transcription factor 2 and osteocalcin protein in chondrocytes were detected by western blot assay. RESULTS AND CONCLUSION: (1) The results of safranin O fast green staining and Osteoarthritis Research Society International score showed that the degree of articular cartilage damage and subchondral osteosclerosis in the control group was more serious than that in the experimental group. (2) The immunohistochemical staining results revealed that the expression level of matrix metalloproteinase 13 in the control group was significantly higher than that in the experimental group. In the experimental group, the level of collagen type II was on a rise, and the levels of Runt-related transcription factor 2 and osteocalcin proteins were on a decline (P < 0.05). (3) The expression levels of matrix metalloproteinase 13 and Runt-related transcription factor 2 were significantly increased after interleukin 1β induction, and the expression level of collagen type II was significantly decreased. After metformin added, the expression levels of matrix metalloproteinase 13 and Runt-related transcription factor 2 were significantly decreased, and the expression level of collagen type II was significantly increased with metformin concentration increasing. (4) In summary, metformin can alleviate the degradation of cartilage and cartilage matrix of early osteoarthritis and inhibit the sclerosis and remodeling of subchondral bone, thereby playing a role in delaying the progress of early osteoarthritis. [ABSTRACT FROM AUTHOR]

目的 比较完全移位型 (Gartland Ⅲ) 儿童肱骨髁上骨折闭合复位后外侧平行和内外双侧交叉2种克氏针固定策 略在围手术期、术后肘关节 Flynn 评分和术后并发症等方面的差异。方法 选取 2017 年 3 月至 2018 年 3 月 55 例符合入选标准 的 Gartland Ⅲ 型肱骨髁上骨折患儿, 分为外侧平行穿针 (LPP) 组 (n=27) 和双侧交叉穿针 (BCP) 组 (n=28) 。比较2组患儿围手 术期指标、术后肘关节 Flynnn 评分和术后并发症发生情况。结果 LPP 组和 BCP 组平均手术时间分别为 (44.18±7.06) 、(48.74±8.75) min, 组间比较差异有统计学意义 (t=2.122, P=0.039) ; 术后 6 个月, LPP 组和 BCP 组患儿的 Flynn 外观因素优 异率分别为 81.48%、 82.14%, Flynn 功能因素优异率分别为 96.30%、 100.00%, 组间比较差异均无统计学意义 (P>0.05) ; LPP 组和 BCP 组患儿并发症累积发生率分别为 7.41%、 10.71%, 组间比较差异无统计学意义 (P>0.05) 。结论 2 种经皮穿针固定 策略在 Flynn 评分和术后并发症方面没有显著差异, 通过适当的技术改良均可获得满意的效果. [ABSTRACT FROM AUTHOR]

BACKGROUND: The pathogenesis of pediatric femoral head necrosis is associated with cartilage injury of the hip joint induced by stress and inflammation. OBJECTIVE: To observe the effect of bone marrow mesenchymal stem cells (BMSCs)/biphasic calcium phosphate ceramics (B-CPC) on cartilage repair in juvenile rats. METHODS: Thirty male Sprague-Dawley rats, aged 1 week, were randomized into three groups. No intervention was done in blank group. A juvenile rat model of articular cartilage injury was made using improved Hulth’s method in control and observational groups, followed by implantation of BMSCs/hydroxyapatite and BMSCs/B-CPC, respectively. Four weeks later, the rat articular cartilage was observed pathologically, and MTT and flow cytometry were employed to detect chondrocyte proliferation and apoptosis, respectively. RESULTS AND CONCLUSION: The articular cartilage of the rats in the blank group was smooth and complete. In the control group, articular cartilage damage was obvious, presenting with rupture, defect and irregularity of the articular cartilage surface, as well as unclear four-layer structure of the cartilage. In the observational group, articular cartilage injury was repaired to some extent. At the same observation time, the cell viability was significantly increased in the observational group compared with the control group (all P < 0.05), and the proportion of apoptotic cells was significantly decreased (all P < 0.05). To conclude, BMSCs/B-CPC composite can promote the cartilage repair in juvenile rats. [ABSTRACT FROM AUTHOR]

BACKGROUND: Studies have shown that hemiarthroplasty is suitable for single femoral head diseases with normal acetabulum. But indications for choosing bone cement or biological fixation types, short- and long-term efficacy as well as the complications have not yet reached agreement. OBJECTIVE: To discuss the efficacy of two kinds of femoral prosthesis for femoral neck fractures in hemiarthroplasty, and the application of three-dimensional CT reconstruction in displaced fractures. METHODS: Clinical data of 73 cases of femoral head fractures undergoing hemiarthroplasty were analyzed retrospectively, and divided into bone cement and biological groups. All patients were followed up for 1.5 years, and the operation indexes, hospitalization time and hip joint function were compared; the consistent degree with intraoperative findings was compared through hip three-dimensional CT and X-ray examination simultaneously. RESULTS AND CONCLUSION: (1) There was no significant difference in the effective rate between groups (P > 0.05). (2) The operation time in the biological group was significantly shorter than that in the bone cement group (P < 0.05); the intraoperative blood loss and hospitalization time in the bone cement group were significantly less than those in the biological group (P < 0.05). (3) The Harris scores in the bone cement group were significantly higher than those in the biological group at 1 month after replacement (P < 0.05); the Harris scores in the biological group were significantly higher than those in the bone cement group at 18 months after replacement (P < 0.05); while there were no significant differences between two groups at 3, 6 and 12 months after replacement. (4) The hip three-dimensional reconstruction and X-ray examination showed no error compared with the intraoperative findings, reaching 100%. (5) Our findings suggest that age, disease history and bone quality should be considered when choosing an appropriate type of hemiarthroplasty for the patients with femoral neck fractures, and bone cement prosthesis is suitable for the elder patients with severe osteoporosis; while those with good bone quality should receive biological prosthesis. Besides, the diagnosis accuracy of three-dimensional reconstruction is superior to X-ray examination, which is conductive to fully understand displaced fractures. [ABSTRACT FROM AUTHOR]