超声波作用下NaBH4/ZrCl4还原9(E)-红霉素肟制备9(S)-红霉胺

9(S)-红霉胺是合成地红霉素和CP-544372的中间体，此化合物可在超声波的作用下利用NaBH4／ZrCl4于室温下还原9(E)-红霉素肟制得，收率为69％，其结构经IR、NMR和MS确证。该方法是制备9(S)-红霉胺的方便、有效的途径。     

也谈“热入血室”

读了《光明中医》2 0 0 4年第 4期李桂英所作《谈谈对“热入血室”的认识》(以下简称李文 )一文后 ,对文中一些观点有所看法 ,下面谈谈几点见解 ,以之商榷。1　“血室”拟应包括子宫 ,以及冲脉和肝脏关于何谓“血室” ,历来虽有冲脉、肝、子宫不同 ,但多数医家根据热入血室与月经有关 ,故从胞宫之说[1] 。而李文则认为“血室”与“女子胞”(即子宫 )有所区别的原因在于“热入血室”的一些临床表现与“热在子宫”缺乏特异性联系 ,但事实并非如此 ,因为冲脉、肝、子宫三者关系确为密切。按照传统中医的观点 ,子宫之中有胞脉 ,连系子宫的还有胞…     

A Survey on Intelligent Screening for Diabetic Retinopathy

Diabetic retinopathy (DR) is one of the leading causes of vision loss and can be effectively avoided by screening, early diagnosis and treatment. In order to increase the universality and efficiency of DR screening, many efforts have been invested in developing intelligent screening, and there have been great advances. In this paper, we survey DR screening from four perspectives: 1) public color fundus image datasets of DR; 2) DR classification and related lesion-extraction approaches; 3) existing computer-aided systems for DR screening; and 4) existing issues, challenges, and research trends. Our goal is to provide insights for future research directions on DR intelligent screening.     

抑郁症及抗抑郁药物对疼痛阈值的影响

抑郁症是一种复杂的临床疾病,患者除了自身情绪的改变外,对于疼痛的感知也会发生 变化。临床中,抑郁症患者的疼痛阈值增高常有报道,抗抑郁药物在治疗抑郁症的同时,也会影响疼痛 阈值。由于病理生理的复杂性,目前关于抑郁症及抗抑郁药物对疼痛阈值的影响及机制的结论阐述较 为单一,但疼痛阈值背后的大脑皮层、脑干的神经机制研究的创新层出不穷。本文就抑郁症及抗抑郁 药物对疼痛阈值的不同影响及潜在的作用机制进行综述,从大脑、脑干、脊髓中的受体与递质方面探讨 疼痛传递及调节的潜在神经机制,旨在为抑郁症患者疼痛阈值改变的机制研究及临床治疗提供思路     

Propofol inhibits the malignant development of osteosarcoma U2OS cells via AMPK/FΟΧO1-mediated autophagy

It has previously been reported that propofol regulates the development of human osteosarcoma (OS). However, the specific molecular mechanisms underlying the effect of propofol on OS remain poorly understood. Therefore, the aim of the present study was to explore the effects of propofol on OS U2OS cells and the potential underlying mechanism. The Cell Counting Kit-8 and colony formation assays were performed to assess cell viability and proliferation. Furthermore, cell apoptosis was assessed using the TUNEL assay and western blotting. Wound healing and Transwell assays were performed to evaluate OS cell migration and invasion abilities, respectively. The protein expression levels of epithelial-mesenchymal transition (EMT)-, autophagy- and adenosine monophosphate-activated protein kinase (AMPK)/FOXO1 signaling pathway-related proteins were also determined using western blotting. The results demonstrated that propofol significantly reduced the viability of OS cells and promoted autophagy in a dose-dependent manner. Moreover, cell treatment with propofol significantly enhanced the protein expression levels of phosphorylated (p)-AMPK and FOXO1, while decreasing the protein levels of p-FOXO1. Furthermore, treatment with propofol significantly suppressed cell viability, migration and invasion abilities and the EMT of OS cells, and potentially promoted cell apoptosis via inducing autophagy via the AMPK/FOXO1 signaling pathway. In summary, the present study indicated that propofol potentially had an inhibitory effect on the development of OS cells via AMPK/FOXO1-mediated autophagy. These results have therefore provided an experimental basis for further studies into the therapeutic effect of propofol on OS.     

改良腭黏膜瓣整复软腭裂的临床观察

目的:探讨整复软腭裂的新术式,重建腭咽闭合的效果。方法:采用腭黏膜瓣后推术对25例软腭裂患者进行整复治疗,并对其进行随访,以了解术后腭咽闭合的情况。结果:所有患者术后腭部创口愈合良好,瘢痕不明显,软腭的活动度良好,且均有良好的腭咽闭合功能。结论:对先天性软腭裂的患者实施该术式整复,能较好地恢复腭咽闭合功能,是较为理想的手术整复方法之一。     

涂布方式对柔性硅胶血管制作质量的影响

目的 探究比较不同涂布方法对复杂柔性硅胶血管仿体制作质量的影响。方法 基于个性化前交通动脉瘤模型,采用喷涂和旋涂两种方法,制作多例硅胶血管仿体,定量比较两种方法在制作同一血管结构时的厚度增长、周向均匀以及透光性等指标。结果 旋涂法在血管大曲率、变径位置和直管位置处的厚度控制以及厚度均匀性占优,且具有较好的透光性和表面光滑性。旋涂法厚度相对偏差较喷涂法分别降低8.9%、10.8%和16.9%。结论 现阶段旋涂法在制作硅胶仿体模型时较喷涂法具有厚度均匀性优势和透光性优势,在大血管流体力学体外实验领域具有十分可期的应用前景。     

Immunosuppressive Tumor Microenvironment and Immunotherapy of Epstein–Barr Virus-Associated Malignancies

The Epstein–Barr virus (EBV) can cause different types of cancer in human beings when the virus infects different cell types with various latent patterns. EBV shapes a distinct and immunosuppressive tumor microenvironment (TME) to its benefit by influencing and interacting with different components in the TME. Different EBV-associated malignancies adopt similar but slightly specific immunosuppressive mechanisms by encoding different EBV products to escape both innate and adaptive immune responses. Strategies reversing the immunosuppressive TME of EBV-associated malignancies have been under evaluation in clinical practice. As the interactions among EBV, tumor cells, and TME are intricate, in this review, we mainly discuss the epidemiology of EBV, the life cycle of EBV, the cellular and molecular composition of TME, and a landscape of different EBV-associated malignancies and immunotherapy by targeting the TME.     

Contribution Ratio Assessment of Process Parameters on Robotic Milling Performance

Robotic milling has broad application prospects in many processing fields. However, the milling performance of a robot in a certain posture, such as in face milling or grooving tasks, is extremely sensitive to process parameters due to the influence of the serial structure of the robot system. Improper process parameters are prone to produce machining defects such as low surface quality. These deficiencies substantially decrease the further application development of robotic milling. Therefore, this paper selected a certain posture and carried out the robotic flat-end milling experiments on a 7075-T651 high-strength aeronautical aluminum alloy under dry conditions. Milling load, surface quality and vibration were selected to assess the influence of process parameters like milling depth, spindle speed and feed rate on the milling performance. Most notably, the contribution ratio based on the analysis of variance (ANOVA) was introduced to statistically investigate the relation between parameters and milling performance. The obtained results show that milling depth is highly significant in milling load, which had a contribution ratio of 69.25%. Milling depth is also highly significant in vibration, which had a contribution ratio of 51.41% in the X direction, 41.42% in the Y direction and 75.97% in the Z direction. Moreover, the spindle speed is highly significant in surface roughness, which had a contribution ratio of 48.02%. This present study aims to quantitatively evaluate the influence of key process parameters on robotic milling performance, which helps to select reasonable milling parameters and improve the milling performance of the robot system. It is beneficial to give full play to the advantages of robots and present more possibilities of robot applications in machining and manufacturing.     

Schisandra chinensis essential oil attenuates acetaminophen-induced liver injury through alleviating oxidative stress and activating autophagy

ContextSchisandra chinensis (Turcz.) Baill. (Magnoliaceae) essential oil (SCEO) composition is rich in lignans that are believed to perform protective effects in the liver.ObjectiveThis study investigates the effects of SCEO in the treatment of acetaminophen (APAP)-induced liver injury in mice.Materials and methodsC57BL/6 mice (n = 56) were randomly divided into seven groups: normal; APAP (300 mg/kg); APAP plus bicyclol (200 mg/kg); APAP plus SCEO (0.25, 0.5, 1, 2 g/kg). Serum biochemical parameters for liver function, inflammatory factors, and antioxidant activities were determined. The protein expression levels of Nrf2, GCLC, GCLM, HO-1, p62, and LC3 were assessed by western blotting. Nrf2, GCLC, HO-1, p62, and LC3 mRNA were detected by real-time PCR.ResultsCompared to APAP overdose, SCEO (2 g/kg) pre-treatment reduced the serum levels of AST (79.4%), ALT (84.6%), TNF-α (57.3%), and IL-6 (53.0%). In addition, SCEO (2 g/kg) markedly suppressed cytochrome P450 2E1 (CYP2E1) (15.4%) and attenuated the exhaustion of GSH (43.6%) and SOD (16.8%), and the accumulation of MDA (22.6%) in the liver, to inhibit the occurrence of oxidative stress. Moreover, hepatic tissues from our experiment revealed that SCEO pre-treatment mitigated liver injury caused by oxidative stress by increasing Nrf2, HO-1, and GCL. Additionally, SCEO activated autophagy, which upregulated hepatic LC3-II and decreased p62 in APAP overdose mice (p < 0.05).Discussion and conclusionsOur evidence demonstrated that SCEO protects hepatocytes from APAP-induced liver injury in vivo and the findings will provide a reliable theoretical basis for developing novel therapeutics.