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121.
122.
目的:研究黄色肉芽肿性胆囊炎(XGC)与胆囊癌的临床特征分析及螺旋CT检查的鉴别诊断价值。方法:选取从2018年1月-2020年12月于我院接受腹部螺旋CT检查的41例XGC患者纳入研究,记作XGC组,另取同期医院接受腹部螺旋CT检查的45例胆囊癌患者作为胆囊癌组。分析两组临床特征、螺旋CT检查结果表现,比较两组血清血管内皮生长因子(VEGF)、糖类抗原19-9(CA19-9)水平的差异。并以病理检查为金标准,分析螺旋CT检查用作XGC与胆囊癌鉴别诊断的价值。结果:XGC组患者食欲下降、体重下降人数占比均低于胆囊癌组(均P<0.05);而两组腹痛、黄疸、发热、白细胞(WBC)升高、谷丙转氨酶(ALT)升高、谷草转氨酶(AST)升高、胆囊扩张发生率对比差异无统计学意义(均P>0.05)。XGC组囊壁增厚均匀、壁内有低密度结节人数占比均低于胆囊癌组,而有肿大淋巴结人数占比高于胆囊癌组(均P<0.05)。螺旋CT检查诊断XGC的灵敏度、特异度、准确度分别为95.12(39/41)、95.56%(43/45)、95.35%(82/86)。XGC组患者血清VEGF、CA19-9水平均低于胆囊癌组,差异均有统计学意义(均P<0.05)。结论:XGC患者食欲下降、体重下降发生率低于胆囊癌患者,螺旋CT检查鉴别诊断XGC与胆囊癌的价值较高,值得临床关注。  相似文献   
123.
Figs and fig pollinators are one of the few classic textbook examples of obligate pollination mutualism. The specific dependence of fig pollinators on the relatively safe living environment with sufficient food sources in the enclosed fig syconia implies that they are vulnerable to habitat changes. However, there is still no extensive genomic evidence to reveal the evolutionary footprint of this long-term mutually beneficial symbiosis in fig pollinators. In fig syconia, there are also non-pollinator species. The non-pollinator species differ in their evolutionary and life histories from pollinators. We conducted comparative analyses on 11 newly sequenced fig wasp genomes and one previously published genome. The pollinators colonized the figs approximately 66.9 million years ago, consistent with the origin of host figs. Compared with nonpollinators, many more genes in pollinators were subject to relaxed selection. Seven genes were absent in pollinators in response to environmental stress and immune activation. Pollinators had more streamlined gene repertoires in the innate immune system, chemosensory toolbox, and detoxification system. Our results provide genomic evidence for the differentiation between pollinators and nonpollinators. The data suggest that owing to the long-term adaptation to the fig, some genes related to functions no longer required are absent in pollinators.  相似文献   
124.
Smoking and Candida albicans (Calbicans) infection are risk factors for many oral diseases. Several studies have reported a close relationship between smoking and the occurrence of Calbicans infection. However, the exact underlying mechanism of this relationship remains unclear. We established a rat infection model and a C. albicans-Leuk1 epithelial cell co-culture model with and without smoke exposure to investigate the mechanism by which smoking contributes to Calbicans infection. Oral mucosa samples from healthy individuals and patients with oral leucoplakia were also analysed according to their smoking status. Our results indicated that smoking induced oxidative stress and redox dysfunction in the oral mucosa. Smoking-induced Nrf2 negatively regulated the NLRP3 inflammasome, impaired the oral mucosal defence response and increased the oral mucosa susceptibility to Calbicans. The results suggest that the Nrf2 pathway could be involved in the pathogenesis of oral diseases by mediating an antioxidative response to cigarette smoke exposure and suppressing host immunity against Calbicans.  相似文献   
125.
Shear stress was reported to regulate the expression of AC007362, but its underlying mechanisms remain to be explored. In this study, to isolate endothelial cells of blood vessels, unruptured and ruptured intracranial aneurysm (IA) tissues were collected from IA patients. Subsequently, quantitative real-time PCR (qRT-PCR), Western blot and luciferase assay were performed to investigate the relationships between AC007362, miRNAs-493 and monocyte chemoattractant protein-1 (MCP-1) in human umbilical vein endothelial cells (HUVECs) exposed to shear stress. Reduced representation bisulphite sequencing (RRBS) was performed to assess the level of DNA methylation in AC007362 promoter. Accordingly, AC007362 and MCP-1 were significantly up-regulated while miR-493 was significantly down-regulated in HUVECs exposed to shear stress. AC007362 could suppress the miR-493 expression and elevate the MCP-1 expression, and miR-493 was shown to respectively target AC007362 and MCP-1. Moreover, shear stress in HUVECs led to the down-regulated DNA methyltransferase 1 (DNMT1), as well as the decreased DNA methylation level of AC007362 promoter. Similar results were also observed in ruptured IA tissues when compared with unruptured IA tissues. In conclusion, this study presented a deep insight into the operation of the regulatory network of AC007362, miR-493 and MCP-1 upon shear stress. Under shear stress, the expression of AC007362 was enhanced by the inhibited promoter DNA methylation, while the expression of MCP-1 was enhanced by sponging the expression of miR-493.  相似文献   
126.
127.
Wang  Yuhan  Wang  Dianhong  Zhang  Xiangli  Huang  Tianye  Zhao  Xiang  Zeng  Shuwen 《Plasmonics (Norwell, Mass.)》2021,16(2):463-469
Plasmonics - By introducing the sub-wavelength grating (SWG) waveguide in the long-range surface phonon resonance (LRSPhR) device, a mid-infrared Fano resonance is formed due to the coupling...  相似文献   
128.
Zhou  Ting  Gou  Xinyu  Xu  Wei  Li  Yong  Zhai  Xiang  Li  Hongjian  Wang  Lingling 《Plasmonics (Norwell, Mass.)》2021,16(2):323-332

We propose a dynamically tunable surface plasmon polaritons (SPPs) waveguide system based on bulk Dirac semimetals (BDS) containing only a side-coupled T-shaped cavity. Plasmon-induced transparency (PIT) is achieved in the terahertz band by introducing a position offset. We have analytically investigated the spectral characteristics of PIT in this system, indicating that the larger the position offset, the higher the peak of the PIT window. The spectrum responses of PIT system can be flexibly regulated via transforming the geometric parameters of the structure. At the same time, it is particularly sensitive to the refractive index of the surrounding medium, which is promising for sensing devices. In addition, the resonance frequency and peak transmission can be actively adjusted by controlling the Fermi energy of the BDS without reconstructing the geometric structure. Moreover, the optical delay time near the PIT peak reaches 11.001 ps, which has good slow-light characteristics and is a candidate in the field of slow-light equipment. The structure we designed may have potential application value in the design of SPPs light-guide devices.

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129.
不同放牧强度对赛罕乌拉草原蜘蛛多样性的影响   总被引:1,自引:0,他引:1  
蜘蛛作为草原生态系统中的主要消费者, 对维系草原生物多样性和生态系统功能具有重大意义。放牧是人类利用草原最普遍的方式, 了解放牧对蜘蛛多样性的影响具有重要生态学意义。本研究调查了内蒙古赛罕乌拉草原上5个不同放牧强度样地中的蜘蛛多样性, 通过单因素方差分析(one-way analysis of variance)比较各样地中的蜘蛛多样性, 非度量多维标度分析(non-metric multidimensional scale, NMDS)和相似性分析(analysis of similarities, ANOSIM)比较各样地间的蜘蛛物种组成相似性, 再结合相关性分析探讨了植被高度对蜘蛛多样性的影响。结果表明: 重度放牧强度样地的蜘蛛多样性显著低于其他未放牧及轻度放牧样地; 具体到常见科上, 放牧强度对织网型的园蛛物种数和个体数影响显著, 而对游猎型的狼蛛、跳蛛却不明显; 织网型蜘蛛主要受植被结构影响, 而游猎型蜘蛛更可能受潜在猎物可得性的影响。NMDS分析表明不同放牧强度下, 蜘蛛类群的物种组成呈现明显的梯度变化, 放牧强度越低, 物种组成和未放牧样地越相近。相关性分析表明草原植被高度与蜘蛛多样性总体上呈正相关关系, 即植被高度越高, 蜘蛛多样性越高。其中依靠植物构建蛛网的园蛛科和在植物上层伏击猎物的蟹蛛科、逍遥蛛科等与植被高度显著相关。这说明植物资源及其空间异质性可能对草原蜘蛛多样性起着主导作用。因此, 降低放牧强度有助于保护草原蜘蛛群落的多样性, 特别有利于织网型蜘蛛。  相似文献   
130.
海南鲌(Culter recurviceps)是我国华南地区重要经济鱼类, 由于受到近些年水利开发、过度捕捞、环境污染等诸多因素的影响, 其资源量快速下降, 亟需得到更多的关注和保护。为保护和合理开发海南鲌种质资源, 本研究采集了华南地区23个地理群体207尾海南鲌样本, 测定了2个线粒体基因(CytbND2)并从Barcode of Life Data System数据库获得相对应线粒体COI基因, 结合多种分析方法(系统发育分析、分化时间估算、单倍型网状图、群体遗传分析和Mantel检验)对海南鲌的遗传结构和遗传多样性展开研究。系统发育分析和单倍型网状图表明华南地区海南鲌群体被分成3个谱系(I、II和III), 其中谱系I和III由珠江的群体组成, 谱系II由海南岛的群体组成。分化时间估算发现3个谱系之间的分化时间介于0.028-0.251 Ma之间, 表明华南地区更新世气候变化可能是造成海南鲌谱系分化的重要原因。群体遗传分析发现海南鲌群体之间存在极显著的遗传分化(FST = 0.511, P < 0.001), 并且符合距离隔离模式(R = 0.348, P = 0.0010)。群体动态历史分析表明, 海南鲌群体可能在0.010-0.025 Ma经历了群体扩张, 表明更新世的气候波动也影响了海南鲌的群体大小和分布。综上所述, 海南鲌群体由3个谱系组成, 更新世气候变化是导致3个谱系分化和影响海南鲌群体动态历史的重要因素。此外, 海南鲌群体之间的遗传分化也可能受到了空间距离的影响。  相似文献   
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