分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: We describe the synthesis of bimetallic dendritic platinum decorated gold nanorods (AuNRs) by the spatial control of Pt growth over gold nanorods using a heterogeneous seed-mediated growth method. The amounts of the Au seed and Pt-precursor were changed to achieve a tunable volume fraction of Pt coverage on the Au NRs surface. Pt nanostructures were spatially separated from each other, which was highly favorable for promising optical and catalytic properties. The dendritic-Pt decorated AuNRs with variable Au/Pt ratios were exploited to study their surface plasmonic properties and catalytic activities. Interestingly, the Pt decorated AuNRs showed strong surface plasmon resonance (SPR) peak due to noncompact dendritic Pt shell in contrast to the conventional core–shell Au@Pt nanoparticles (NPs). Moreover, the longitudinal peak of the AuNRs was finely tuned from 820 to 950 nm (NIR region) by controlling the volume fraction of the Pt decoration over the AuNRs. The catalytic activity of the dendritic-Pt decorated AuNRs on the reduction of 4-nitrophenol (4-NP) by sodium borohydride (NaBH4) as reducing agent was studied and found to be superior to the activities compared to the monometallic Au NRs. Considering practical applications, dendritic-Pt decorated AuNRs nanostructures were immobilized successfully on the hydrophilic polyvinylidene difluoride (PVDF) film as an efficient reusable catalyst.
分类: 生物学 >> 神经生物学 分类: 医学、药学 >> 基础医学 提交时间: 2020-03-23
摘要: 在临床实践中,大脑在心脏停跳数分钟后会出现不可逆的损伤,如果30分钟后患者仍未能成功复苏,将被宣布临床死亡。最新研究显示,在心脏停跳后数小时后,猪的大脑细胞功能仍可在体外得到恢复。然而,在离体状态下意识能否恢复尚不清楚。本研究中,我们建立了用于循环停止后大脑体外复苏的常温机械灌注技术。我们发现大脑单独灌注即能维持大脑循环、细胞结构、代谢活动和脑干功能,但不能恢复大脑意识。而在肝脏的支持下,大脑整体的电活动和意识得以恢复,大脑功能至少可以维持22小时。该技术能够使热缺血50分钟的大脑恢复意识。研究结果表明,肝脏辅助下的大脑常温机械灌注技术可以在循环停止较长时间内恢复和维持大脑的意识。
分类: 医学、药学 >> 临床医学 提交时间: 2021-10-02
摘要: Ischemia and reperfusion injury (IRI), an inevitable component in organ transplantation, contributes to inferior graft survival, compromised organ quality and limitations in organ availability. The heart is most vulnerable to IRI and tolerated ischemic times are very short. We present an entire novel heart transplant procedure during which the donor heart was continuously perfused, oxygenated at normothermia and transplanted while beating. The dynamic electrocardiogram and echocardiogram indicated an absence of ischemic injury and excellent function of the donor heart during the entire procedure. This ischemia-free beating heart transplantation (IFBHT) avoids graft IRI. The approach has thus the potential to improve transplant outcome while improving organ utilization.