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1.
Transferrin receptor (TfR) has been used as a target for the antibody-based therapy of cancer due to its higher expression in tumors relative to normal tissues. Great potential has been shown by anti-TfR antibodies combined with chemotherapeutic drugs as a possible cancer therapeutic strategy. In our study, we investigated the anti-tumor effects of anti-TfR monoclonal antibody (mAb) alone or in combination with sinomenine hydrochloride in vitro. Results suggested that anti-TfR mAb or sinomenine hydrochloride could induce apoptosis, inhibit proliferation, and affect the cell cycle. A synergistic effect was found in relation to tumor growth inhibition and the induction of apoptosis when anti-TfR mAb and sinomenine hydrochloride were used simultaneously. The expression of COX-2 and VEGF protein in HepG2 cells treated with anti-TfR mAb alone was increased in line with increasing dosage of the agent. In contrast, COX-2 expression was dramatically decreased in HepG2 cells treated with sinomenine hydrochloride alone. Furthermore, we demonstrated that the inhibitory effects of sinomenine hydrochloride and anti-TfR mAb administered in combination were more prominent than when the agents were administered singly. To sum up, these results showed that the combined use of sinomenine hydrochloride and anti-TfR mAb may exert synergistic inhibitory effects on human hepatoma HepG2 cells in a COX-2-dependent manner. This finding provides new insight into how tumor cells overcome the interference of iron intake to survive and forms the basis of a new therapeutic strategy involving the development of anti-TfR mAb combined with sinomenine hydrochloride for liver cancer.  相似文献   
2.
In this study, the microwave rewarming process of cryopreserved samples with embedded superparamagnetic (SPM) nanoparticles was numerically simulated. The Finite Element Method (FEM) was used to calculate the coupling of the electromagnetic field and the temperature field in a microwave rewarming system composed of a cylindrical resonant cavity, an antenna source, and a frozen sample phantom with temperature-dependent properties. The heat generated by the sample and the nanoparticles inside the electromagnetic field of the microwave cavity was calculated. The dielectric properties of the biological tissues were approximated using the Debye model, which is applicable at different temperatures. The numerical results showed that, during the rewarming process of the sample phantom without nanoparticles, the rewarming rate was 29.45 °C/min and the maximum temperature gradient in the sample was 3.58 °C/mm. If nanoparticles were embedded in the sample, and the cavity power was unchanged, the rewarming rate was 47.76 °C/min and the maximum temperature gradient in the sample was 1.64 °C/mm. In the presence of SPM nanoparticles, the rewarming rate and the maximum temperature gradient were able to reach 20.73 °C/min and 0.68 °C/mm at the end of the rewarming under the optimized cavity power setting, respectively. The ability to change these temperature behaviors may prevent devitrification and would greatly diminish thermal stress during the rewarming process. The results indicate that the rewarming rate and the uniformity of temperature distribution are increased by nanoparticles. This could be because nanoparticles generated heat in the sample homogeneously and the time-dependent parameters of the sample improved after nanoparticles were homogeneously embedded within it. We were thus able to estimate the positive effect of SPM nanoparticles on microwave rewarming of cryopreserved samples.  相似文献   
3.
咖啡碱是茶树的主要生物碱和特征性物质之一,通过滤纸片法、生长速率法、饲喂称重法对咖啡碱抑菌、抗虫作用的研究,发现咖啡碱对供试细菌和真菌有一定的抑菌能力,对棉铃虫和菜粉蝶、家蚕幼虫具有毒害和抑制生长的影响。咖啡碱作为茶树的次生代谢产物具有抗病抗虫的的生物学功能。  相似文献   
4.
项和雨  邹斌  唐亮  陈维国  饶凯锋  刘勇  马梅  杨艳 《生态学报》2021,41(17):6883-6892
浮游植物作为水生态系统中最重要的生物组成部分之一,对水环境敏感,在水环境监测中得到了广泛的关注。然而水生环境复杂多样,准确高效地识别浮游植物是监测工作中的一大挑战。当前浮游植物识别方法可分为经典形态学分类、分子标记和人工智能图像识别三类。前两种方法已被广泛采用,但费时费力,不利于监测机构的大规模应用和推广。同样,利用图像进行自动化分类难以在高准确率与高效率上达到平衡。深度学习技术的发展为此提供了新思路。本文提出一种新的深度卷积神经网络RAN-11。该网络以残差注意力网络Attention-56和Attention-92为基础,凭借通道对齐融合主干上的底层特征与顶层特征,通过调整注意力模块和残差快个数以精简结构,并引入了Leaky ReLU激活函数代替ReLU。以太湖11个优势属共计1036张图像为数据来源进行对比验证。除星杆藻外,RAN-11对单一优势属的的查准率都在90%以上,并且有5个优势属达到100%的查准率。RAN-11的识别准确率为95.67%,推理速率为41.5帧/s,不仅比Attention-92(95.19%的准确率,23.6帧/s)更准确,而且比Attention-56(94.71%的准确率,41.2帧/s)更快,真正兼顾了准确率与效率。研究结果表明:(1)RAN-11在查准率、准确率和推理速率上优于原始残差注意力网络,更优于以词包模型为代表的传统图像识别方法;(2)融合多尺度特征、精简网络结构和优化激活函数是提高卷积神经网络性能的有力手段。建立在经典分类基础之上,本文提出新的残差注意力网络来提升浮游植物鉴定技术,并构建出浮游植物自动化识别系统,识别准确率高、易于推广,对于实现水体中浮游植物的自动化监测具有重要意义。  相似文献   
5.
Insertion/deletion (InDel) markers are valuable for genetic applications in plant species, and the public databases of expressed sequence tags (ESTs) have facilitated the development of genic InDel markers. In this study, we developed a novel set of 144 InDel markers in an important tree genus Eucalyptus L’Hérit. using the ESTs of GenBank. Amplicon sequencing against two parents of a mapping population (Eucalyptus urophylla S. T. Blake × E. tereticornis Smith) revealed that the InDel size ranged from 2 to 44 bases, and the dinucleotide type was the most abundant (37.3 %). The cross-species/subgenus amplification rate ranged from 62.5 % in E. tessellaris F. Muell. (subgenus Blakella) to 99.3 % in E. grandis Hill ex Maiden (subgenus Symphyomyrtus) with an average of 85.4 %. There were 121 EST-InDels (84.0 %) polymorphic among 12 individuals of E. grandis, and the mean number of alleles per polymorphic locus (N a), observed heterozygosity (H o), expected heterozygosity (H e) and polymorphic information content (PIC) were 4.0, 0.278, 0.538 and 0.465, respectively. Physical positions of 143 EST-InDels were predicted on the E. grandis genome sequence. A total of 81 EST-InDels were incorporated into prior dense genetic maps of E. urophylla and E. tereticonis, and extensive synteny and colinearity were observed between E. grandis genome sequence and the mapped EST-InDel markers. These EST-InDels will provide a valuable resource of functional markers for genetic diversity evaluation, genome comparison, QTL mapping and marker-assisted breeding in Eucalyptus.  相似文献   
6.
Myocardial infarction is a major cause of death worldwide. Despite our understanding of the pathophysiology of myocardial infarction and the therapeutic options for treatment have improved substantially, acute myocardial infarction remains a leading cause of morbidity and mortality. Recent findings revealed that GRP78 could protect myocardial cells against ischemia reperfusion injury‐induced apoptosis, but the exact function and molecular mechanism remains unclear. In this study, we aimed to explore the effects of GRP78 on hypoxia/reperfusion (H/R)‐induced cardiomyocyte injury. Intriguingly, we first observed that GRP78 overexpression significantly protected myocytes from H/R‐induced apoptosis. On mechanism, our work revealed that GRP78 protected myocardial cells from hypoxia/reperfusion‐induced apoptosis via the activation of the Nrf2/HO‐1 signaling pathway. We observed the enhanced expression of Nrf2/HO‐1 in GRP78 overexpressed H9c2 cell, while GRP78 deficiency dramatically antagonized the expression of Nrf2/HO‐1. Furthermore, we found that blocked the Nrf2/HO‐1 signaling by the HO‐1 inhibitor zinc protoporphyrin IX (Znpp) significantly retrieved H9c2 cells apoptosis that inhibited by GRP78 overexpression. Taken together, our findings revealed a new mechanism by which GRP78 alleviated H/R‐induced cardiomyocyte apoptosis in H9c2 cells via the promotion of the Nrf2/HO‐1 signaling pathway.  相似文献   
7.
Graphene oxide‐based nanomaterials are promising for enzyme immobilization due to the possibilities of functionalizing surface. Polyethylenimine‐grafted graphene oxide was constructed as a novel scaffold for immobilization of formate dehydrogenase. Compared with free formate dehydrogenase and graphene oxide adsorbed formate dehydrogenase, thermostability, storage stability, and reusability of polyethylenimine‐grafted graphene oxide‐formate dehydrogenase were enhanced. Typically, polyethylenimine‐grafted graphene oxide‐formate dehydrogenase remained 47.4% activity after eight times’ repeat reaction. The immobilized capacity of the polyethylenimine‐grafted graphene oxide was 2.4‐folds of that of graphene oxide. Morphological and functional analysis of polyethylenimine‐grafted graphene oxide‐formate dehydrogenase was performed and the assembling mechanism based on multi‐level interactions was studied. Consequently, this practical and facile strategy will likely find applications in biosynthesis, biosensing, and biomedical engineering.  相似文献   
8.
绿色杜氏藻转录组分析   总被引:1,自引:0,他引:1  
朱帅旗  龚一富  杭雨晴  刘浩  王何瑜 《遗传》2015,37(8):828-836
为了深入了解绿色杜氏藻(Dunaliella viridis)基因信息及功能、耐盐相关通路(甘油脂代谢)及关键酶,本文首次通过Illumina HiSeqTM 2000高通量测序技术对绿色杜氏藻转录组进行测序,利用Trinity软件将数据组装形成转录本,对所有转录本进行COG(Clusters of Orthologous Groups)、GO(Gene Ontology)和KEGG(Kyoto Encyclopedia of Genes and Genomes)分类和功能注释、Pathway注释以及蛋白编码区(Opening reading fragment,ORF)的预测,并对甘油脂代谢通路关键酶基因进行了分析。转录组测序共获得81 593个转录本,其中ORF共有77 117条,约占所有转录本的94.50%。COG分类结果表明,16 569条转录本被分为24个类别。GO分类结果表明,76 436条转录本被注释。在所有注释分类中,生物学过程转录本数量最多,为30 678条,占总转录本数的40.14%。KEGG分析结果表明,317个标准途径中包含26 428条转录本,含转录本最多的类别是代谢,为9949条(37.65%)。与代谢有关的途径为131条,占所有注释途径的41.32%。在甘油脂代谢通路中仅发现1条关键酶转录本(二羟丙酮激酶),该酶可能与绿色杜氏藻耐盐胁迫中甘油的合成有较大关系。本研究进一步完善了绿色杜氏藻的基因信息,为绿色杜氏藻代谢途径研究奠定了坚实的基础。  相似文献   
9.
Yang Y  Shi Z  Reheman A  Jin JW  Li C  Wang Y  Andrews MC  Chen P  Zhu G  Ling W  Ni H 《PloS one》2012,7(5):e37323
Delphinidin-3-glucoside (Dp-3-g) is one of the predominant bioactive compounds of anthocyanins in many plant foods. Although several anthocyanin compounds have been reported to be protective against cardiovascular diseases (CVDs), the direct effect of anthocyanins on platelets, the key players in atherothrombosis, has not been studied. The roles of Dp-3-g in platelet function are completely unknown. The present study investigated the effects of Dp-3-g on platelet activation and several thrombosis models in vitro and in vivo. We found that Dp-3-g significantly inhibited human and murine platelet aggregation in both platelet-rich plasma and purified platelets. It also markedly reduced thrombus growth in human and murine blood in perfusion chambers at both low and high shear rates. Using intravital microscopy, we observed that Dp-3-g decreased platelet deposition, destabilized thrombi, and prolonged the time required for vessel occlusion. Dp-3-g also significantly inhibited thrombus growth in a carotid artery thrombosis model. To elucidate the mechanisms, we examined platelet activation markers via flow cytometry and found that Dp-3-g significantly inhibited the expression of P-selectin, CD63, CD40L, which reflect platelet α- and δ-granule release, and cytosol protein secretion, respectively. We further demonstrated that Dp-3-g downregulated the expression of active integrin αIIbβ3 on platelets, and attenuated fibrinogen binding to platelets following agonist treatment, without interfering with the direct interaction between fibrinogen and integrin αIIbβ3. We found that Dp-3-g reduced phosphorylation of adenosine monophosphate-activated protein kinase, which may contribute to the observed inhibitory effects on platelet activation. Thus, Dp-3-g significantly inhibits platelet activation and attenuates thrombus growth at both arterial and venous shear stresses, which likely contributes to its protective roles against thrombosis and CVDs.  相似文献   
10.
Corals are colonized by symbiotic microorganisms that profoundly influence the animal’s health. One noted symbiont is a single-celled alga (in the dinoflagellate family Symbiodiniaceae), which provides the coral with most of its fixed carbon. Thermal stress increases the production of reactive oxygen species (ROS) by Symbiodiniaceae during photosynthesis. ROS can both damage the algal symbiont’s photosynthetic machinery and inhibit its repair, causing a positive feedback loop for the toxic accumulation of ROS. If not scavenged by the antioxidant network, excess ROS may trigger a signaling cascade ending with the coral host and algal symbiont disassociating in a process known as bleaching. We use Exaiptasia diaphana as a model for corals and constructed a consortium comprised of E. diaphana–associated bacteria capable of neutralizing ROS. We identified six strains with high free radical scavenging (FRS) ability belonging to the families Alteromonadaceae, Rhodobacteraceae, Flavobacteriaceae and Micrococcaceae. In parallel, we established a consortium of low FRS isolates consisting of genetically related strains. Bacterial whole genome sequences were used to identify key pathways that are known to influence ROS.  相似文献   
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