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目的 对绿藻多糖UCS2的结构特征和抗凝血活性进行研究。方法 通过冷水提取、强阴离子交换色谱和凝胶渗透色谱,从绿藻花石莼中提取分离得到硫酸多糖UCS2;采用高效凝胶渗透色谱(HPGPC)、高效液相色谱、红外光谱和气质联用色谱对多糖UCS2的结构进行表征;通过活化部分凝血活酶时间(APTT)、凝血酶时间、凝血酶原时间对多糖UCS2体外抗凝血活性进行研究。结果 绿藻多糖UCS2分子量为39.55kDa,硫酸根和糖醛酸含量分别为19.74%和18.66%;UCS2主要由鼠李糖组成,含有少量葡糖醛酸和木糖。糖链中含有→3,4)-α-L-Rhap-(1→, →4)-α-L-Rhap-(1→, →4)-β-D-Xylp-(1→和→4)-β-D-GlcAp-(1→,硫酸基位于→4)-α-L-Rhap-(1→的C-3位。多糖UCS2对APTT有显著延长作用,具有较高的抗凝活性。结论 绿藻多糖UCS2是1种抗凝活性的葡萄糖醛酸-木糖-鼠李糖型硫酸多糖。 相似文献
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减毒沙门菌对实体瘤具有广谱的肿瘤靶向特异性,其可通过激活机体抗肿瘤免疫应答改善肿瘤免疫微环境,从而抑 制肿瘤的发展;高度的肿瘤靶向特异性使得减毒沙门菌可作为理想的抗癌药物与影像探针的表达和递送载体,实现肿瘤诊疗一 体化。减毒沙门菌在基础或临床领域已有着广泛的研究与应用,展现了良好的应用前景,未来可期。对减毒沙门菌的抗肿瘤机 制、应用现状及目前所存在的问题展开分析,探讨如何通过遗传工程技术对减毒菌的安全性、靶向性和抗癌效果等方面进行提 升,将促进减毒沙门菌的转化应用,实现免疫学、生物技术等多学科的交叉融合,有望为临床肿瘤生物治疗提供新的研究方向。 相似文献
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目的通过载药量对后交联凝胶贴膏流变学及体外经皮渗透特性的影响,考察后交联凝胶贴膏基质的载药量。方法采用流变学技术测定不同载药量时胶料的各项流变学参数,并以祖师麻乙醇提取物为模型药物,以祖师麻甲素的累积透过率及皮肤滞留率为指标,对成品贴膏进行体外经皮渗透试验,确定基质载药量。结果当载药量在4.0%~12.4%时,含药胶料的结构强度、黏弹性、耐温耐剪切性及抗变形能力、稳定性均符合要求,其中以载药量为6.8%时最佳;祖师麻甲素的累积透过率随载药量逐渐增大,皮肤滞留率分别变化不明显。结论通过比较流变学及体外经皮渗透试验结果,确定基质处方的最佳载药量为6.8%。 相似文献
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Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer's disease. However, it is not yet possible to easily detect these abnormalities using head computed tomography in the early stages of the disease. In this review, we evaluated the ways in which modern imaging techniques such as positron emission computed tomography, single photon emission tomography, magnetic resonance spectrum imaging, structural magnetic resonance imaging, magnetic resonance diffusion tensor imaging, magnetic resonance perfusion weighted imaging, magnetic resonance sensitive weighted imaging, and functional magnetic resonance imaging have revealed specific changes not only in brain structure, but also in brain function in Alzheimer's disease patients. The reviewed literature indicated that decreased fluorodeoxyglucose metabolism in the temporal and parietal lobes of Alzheimer's disease patients is frequently observed via positron emission computed tomography. Furthermore, patients with Alzheimer's disease often show a decreased N-acetylaspartic acid/creatine ratio and an increased myoinositol/creatine ratio revealed via magnetic resonance imaging. Atrophy of the entorhinal cortex, hippocampus, and posterior cingulate gyrus can be detected early using structural magnetic resonance imaging. Magnetic resonance sensitive weighted imaging can show small bleeds and abnormal iron metabolism. Task-related functional magnetic resonance imaging can display brain function activity through cerebral blood oxygenation. Resting functional magnetic resonance imaging can display the functional connection between brain neural networks. These are helpful for the differential diagnosis and experimental study of Alzheimer's disease, and are valuable for exploring the pathogenesis of Alzheimer's disease. 相似文献
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Mutations in leucine rich repeat kinase 2 (LRRK2) are a major cause of familial Parkinson's disease (PD) and a risk factor for its sporadic form. LRRK2 hyperactivity has also been reported in sporadic PD, making LRRK2 an appealing target for PD small-molecule therapeutics. At a cellular level, increasing evidence suggests that LRRK2 regulates membrane trafficking. Under some conditions LRRK2 also associates with microtubules, the cellular tracks used by dynein and kinesin motors to move membranes. At a structural level, however, relatively little was known about LRRK2. An important step toward bridging this gap took place last year with the publication of structures of LRRK2's cytosolic and microtubule-bound forms. Here, we review the main findings from these studies and discuss what we see as the major challenges going forward with a focus on areas that will require structural information. We also introduce the structural techniques—cryo-electron microscopy and cryo-electron tomography—that were instrumental to solving the structures of LRRK2. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society 相似文献
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ObjectiveOpen injuries of the Tendoachilles present a challenge to the treating surgeon. Although, common in our setting, there is a paucity of literature regarding management of the same. The purpose of this retrospective study was to analyse the functional outcomes following debridement and primary repair of open tears of the Tendoachilles.Materials and methodsPatients with open tears of the tendoachilles, between January 2012 to January 2017. After obtaining demographic data, including mechanism of injury, all patients were managed by adequate debridement and primary repair, by Pennington’s modification of Kessler’s technique in a single sitting, paratenon closed circumferentially, plantaris reinforcement used when end to end repair couldn’t be achieved. Below knee cast for 2 months. Weight bearing started at three months. Statistical analysis using paired t-test for calf circumference, ankle range of motion comparing with uninjured limb. Functional outcome assessment by AOFAS hindfoot score and Achilles tendon rupture score.Results23 male patients, mean age 35, were analysed. Field injury was the most common mechanism, with slip in Indian lavatory pans accounting for four patients. Average time to surgery from injury was 22 hours. Plantaris reinforcement in one case. No case of wound dehiscence, scar adherence, tendon rerupture or infection. One patient had serous discharge at three weeks which settled with oral antibiotics. 21 patients performed single heel raise. There was no significant difference in calf circumference and ankle range of motion compared to uninjured limb. Mean AOFAS score was 92, mean Achilles tendon rupture score 77.ConclusionThough open injuries of the tendoachilles is fraught with complications, early debridement, adequate repair of the tendon edges with circumferential closure of the paratenon, yields adequate functional outcomes with minimal complications. 相似文献
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Fiber Bragg grating (FBG)-based acoustic emission (AE) detection and monitoring is considered as a potential and emerging technology for structural health monitoring (SHM) applications. In this paper, an overview of the FBG-based AE monitoring system is presented, and various technologies and methods used for FBG AE interrogation systems are reviewed and discussed. Various commercial FBG AE sensing systems, SHM applications of FBG AE monitoring, and market potential and recent trends are also discussed. 相似文献