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500 个结果
  • 简介:摘要:C4F7N因其优异的绝缘和环保特性成为最有潜力替代SF6气体的绝缘介质,分析阐述了C4F7N-C02混合气体的绝缘性能和分解产物,国内现状常见环网环保气体绝缘结构形态,进而阐述我司推出的方案以及相关试验验证,C4F7N-C02环保气体有代替SF6的可能。

  • 标签: C4F7N-C02混合气体 环保气体 气体特性 分解产物 代替SF6
  • 简介:摘要:  晓南矿N1-15层施工完毕后巷道变形量较大,为满足生产需要进行了维修,维修后通过对巷道表面位移观测得出巷道变形规律,提出控制巷道变形的措施,为以后维修工作提供了参考资料。

  • 标签:   位移 变形 支护
  • 简介:[摘要]  中职数学在日常教学中经常出现“教师讲不动,学生听不懂”的现象,中职生学习数学的困难,远超出教师的想象和认识。在《等差数列前n项和》教学中,采用数据驱动教学模式,帮助数学教师在更全面、准确了解中职生的学情后再“对症下药”,从而提高他们的学习热情和效率。

  • 标签: []  数据驱动 信息化 数列求和
  • 简介:[摘要]  中职数学在日常教学中经常出现“教师讲不动,学生听不懂”的现象,中职生学习数学的困难,远超出教师的想象和认识。在《等差数列前n项和》教学中,采用数据驱动教学模式,帮助数学教师在更全面、准确了解中职生的学情后再“对症下药”,从而提高他们的学习热情和效率。

  • 标签: []  数据驱动 信息化 数列求和
  • 简介:AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve, generating new variants that pose a threat to global health; therefore, it is imperative to obtain safe and broad-spectrum antivirals against SARS-CoV-2 and its variants. To this end, we screened compounds for their ability to inhibit viral entry, which is a critical step in virus infection. Twenty compounds that have been previously reported to inhibit SARS-CoV-2 replication were tested by using pseudoviruses containing the spike protein from the original strain (SARS-CoV-2-WH01). The cytotoxicity of these compounds was determined. Furthermore, we identified six compounds with strong antagonistic activity against the WH01 pseudovirus, and low cytotoxicity was identified. These compounds were then evaluated for their efficacy against pseudoviruses expressing the spike protein from B.1.617.2 (Delta) and B.1.1.529 (Omicron), the two most prevalent circulating strains. These assays demonstrated that two phenothiazine compounds, trifluoperazine 2HCl and thioridazine HCl, inhibit the infection of Delta and Omicron pseudoviruses. Finally, we discovered that these two compounds were highly effective against authentic SARS-CoV-2 viruses, including the WH01, Delta, and Omicron strains. Our study identified potential broad-spectrum SARS-CoV-2 inhibitors and provided insights into the development of novel therapeutics.

  • 标签: SARS-CoV-2 Delta variant Omicron variant Trifluoperazine 2HCl Thioridazine HCl Antiviral therapy
  • 简介:AbstractOmicron (B.1.1.529), the fifth variant of concern (VOC) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was firstly identified in November 2021 in South Africa. Omicron contains far more genome mutations than any other VOCs ever found, raising significant concerns about its increased transmissibility and immune evasion. Here, we report the importation of the Omicron variant into Beijing, China, in December 2021. Full-length genome sequences of five imported strains were obtained, with their genetic features characterized. Each strain contained 57 to 61 nucleotide substitutions, 39 deletions, and 9 insertions in the genome. Thirty to thirty-two amino acid changes were found in the spike proteins of the five strains. The phylogenetic tree constructed by the maximum likelihood method showed that all five imported genomes belonged to Omicron (BA.1) (alias of B.1.1.529.1), which is leading to the current surge of coronavirus disease 2019 (COVID-19) cases worldwide. The globally increased COVID-19 cases driven by the Omicron variant pose a significant challenge to disease prevention and control in China. Continuous viral genetic surveillance and increased testing among international travellers are required to contain this highly contagious variant.

  • 标签: COVID-19 SARS-CoV-2 Omicron variant Genomic characteristics
  • 简介:AbstractAt present, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread worldwide, which has emerged multiple variants and brought a threat to global public health. To analyze the genomic characteristics and variations of SARS-CoV-2 imported into Beijing, we collected the respiratory tract specimens of 112 cases of coronavirus disease 2019 (COVID-19) from January to September 2021 in Beijing, China, including 40 local cases and 72 imported cases. The whole-genome sequences of the viruses were sequenced by the next-generation sequencing method. Variant markers and phylogenic features of SARS-CoV-2 were analyzed. Our results showed that in all 112 sequences, the mutations were concentrated in spike protein. D614G was found in all sequences, and mutations including L452R, T478K, P681R/H, and D950N in some cases. Furthermore, 112 sequences belonged to 23 lineages by phylogenetic analysis. B.1.1.7 (Alpha) and B.1.617.2 (Delta) lineages were dominant. Our study drew a variation image of SARS-CoV-2 and could help evaluate the potential risk of COVID-19 for pandemic preparedness and response.

  • 标签: Severe acute respiratory syndrome coronavirus 2 Variation Genome Phylogenetic analysis
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  • 简介:摘要本文报道2例胎儿Pierre Robin序列征(PRS),由胎儿MRI诊断并在引产或生后得以证实。PRS在胎儿MRI上表现为小下颌、舌根后坠、气道变窄及腭裂。MRI诊断PRS有较高的敏感性,可诊断胎儿PRS伴随的结构畸形,给予围生期咨询提供一定指导建议。

  • 标签: 胎儿 Pierre Robin序列征 磁共振成像
  • 简介:摘要本文报道椎管内孤立性纤维性肿瘤2例。该2例患者分别因双下肢无力伴小便失禁2个月余和右下肢麻木半年就诊,MRI上表现为与椎管平行的椭圆形肿块,边界清晰,T1WI呈等信号,T2WI呈等或稍高信号;增强扫描呈明显均匀或不均匀强化。最终术后病理诊断为椎管内孤立性纤维性肿瘤。

  • 标签: 孤立性纤维瘤 椎管 磁共振成像
  • 简介:摘要椎动脉外伤后出血量大且凶猛,容易被误诊为颈动脉损伤,临床中颈部外伤单纯伤及椎动脉少见,我们诊治2例椎动脉破裂出血患者。患者1,女性,41岁,颈部外伤4 h,探查后行左侧椎动脉吻合+左侧椎前静脉修补+左侧颈内、颈外静脉结扎术,术后10 d患者出现头晕,颅脑MR检查考虑左侧小脑半球脑梗死,椎动脉闭塞、狭窄,应用抗凝药物治疗4个月后头晕症状消失。患者2,女性,28岁,右侧颈部肿胀10 h,数字减影血管造影(DSA)检查示椎动脉起始段假性动脉瘤,介入手术止血困难,暂行颈部填塞后予抗感染治疗,术后4 d行颈部探查+气管切开术,术后18 d再行介入手术,患者出院前气管套管拔除,右上肢肌力0级。

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  • 简介:摘要患儿 男,11月龄,以频繁成簇抽搐发作起病,予地西泮、苯巴比妥及丙戊酸钠联合治疗无效,每天抽搐发作数十次,起病第4天因癫痫持续状态入住重症监护病房治疗,并出现嗜睡、意识模糊、不能认人、不自主动作、偶兴奋尖叫、夜间睡眠时间减少,脑电图背景活动慢化,监测到频繁后头部起源的临床发作及电发作,脑脊液抗AMPA2受体IgG抗体阳性,诊断抗AMPA2受体脑炎。予人免疫球蛋白及激素冲击免疫治疗,加用拉考沙胺并减停丙戊酸后抽搐缓解,意识转清。临床上以频繁局灶抽搐发作伴有意识水平下降为主要表现的婴儿,应注意鉴别抗AMPA2受体脑炎,尽早启用免疫治疗改善预后至关重要。

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  • 简介:摘要孤立性纤维性肿瘤(SFT)作为一种梭形细胞间叶源性肿瘤,好发于胸膜,也可发生于身体其他部位,其中眼内SFT十分罕见。本文报道2例脉络膜SFT患者,经临床、影像学、组织病理学及免疫组织化学等检查确诊。眼球摘除术后目前均未见复发或转移。

  • 标签: 脉络膜肿瘤 孤立性纤维瘤
  • 简介:摘要2岁6月龄和10月龄患儿均以排稀水便起病,临床表现为顽固性腹泻、大量水样便、重度营养不良、低蛋白血症,病理示小肠黏膜绒毛萎缩,固有膜淋巴细胞浸润,伴隐窝凋亡,例1血清抗杯状细胞抗体阳性,2例患儿诊断为自身免疫性肠病。该病临床罕见,以营养支持及免疫抑制治疗为主。

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  • 简介:摘要新型冠状病毒肺炎疫情在世界范围肆虐,给全球公共卫生事业带来了极大冲击。本文从严重急性呼吸综合征冠状病毒2(SARS-CoV-2)引起的固有免疫应答、体液免疫应答、细胞免疫应答、免疫逃避与交叉免疫五方面对现有研究进行综述,希望通过阐述免疫机制中的作用靶点,为SARS-CoV-2的治疗与预防贡献新思路。

  • 标签: 新型冠状病毒 适应性免疫 免疫逃避 交叉免疫
  • 简介:摘要CD99L2(CD99 antigen-like 2)基因位于染色体Xq28,编码高度保守、广泛表达的糖基化跨膜蛋白。自2003年首次报道以来,CD99L2蛋白被认为是一种重要的黏附分子,在炎症反应、白细胞渗出、淋巴瘤中起重要作用。但是,近年越来越多研究发现该基因与孤独症谱系障碍、脑性瘫痪、癫痫等神经系统疾病密切相关,但具体机制仍不清楚,该基因功能至今未明确。该文就CD99L2基因的研究进展进行综述。

  • 标签: CD99L2基因 炎症反应 淋巴瘤 神经系统疾病
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  • 简介:【摘要】糖尿病指的是一种以糖脂代谢紊乱为主要特征的慢性代谢性疾病。糖尿病最大的几个特点是发病率高、致残率高、并发症多、死亡率高。由于糖尿病这一疾病本身以及由其引发的并发症正在严重影响着病人的身心健康,因此,在日常生活中,糖尿病人必须合理控制自身的血糖,如此方能够有效减少并发症。当前治疗糖尿病的主要目的就是促进患者自身营养的吸收,以提高其生活质量,最终使得糖尿病人的寿命得以延长。对糖尿病患者实行临床营养治疗的主要目的就是使病人的膳食结构能够得到平衡,在合理摄入营养的同时,还应该口服降糖药并且定期摄入胰岛素,必要时还应该与体力活动相配合,如此方能够将血糖保持在一个比较理想的状态之中。在糖尿病的各个治疗阶段中,营养治疗都起着至关重要的作用。正确的对2型糖尿病患者使用营养干预等方式进行治疗,不仅能够有效改善患者的血糖、血压、血脂等各项指标,对于患者的临床治疗与病情恢复更是有着极其重大的意义。

  • 标签: 2型糖尿病 营养治疗 探究
  • 简介:摘要:CO2气体溶于水中形成碳酸后引起电化学腐蚀,如不及时采取有效措施,将导致油套管的严重破坏甚至油井报废。CO2对油、套管的腐蚀是油田开发的一个亟待解决的重要课题。

  • 标签: CO2腐蚀电化学腐蚀影响因素防腐蚀技术