异核双金属探针在活细胞细胞核和线粒体中选择性定位DNA

用于实时成像活细胞DNA的细胞核探针是非常罕见的。通过Ru(N^N)₃、Ir(C^N)₂(N^N)、Re(CO)₃Cl(N^N)和Pt(C^N)(N^N)的结合,生成了4种异核双金属配合物：2种不同的功能金属位点被锚定在线性双齿螯和配体(N^N)-(N^N)的尾端,形成不对称哑铃状的双金属分子M₁-M₂,即Ru-Re、Ru-Pt、Ir-Re和Ir-Pt。Ru-Re和Ru-Pt的红色发射探针具有较大的斯托克斯位移、优异的核膜穿透能力、良好光稳定性的DNA结合能力。此外,Ru-Re和Ru-Pt探针的DNA成像可与专门用于活细胞细胞核DNA染色的Hoechst 33342商用染料相媲美,而Ir-Re和Ir-Pt探针直接靶向线粒体。不同探针的发光特性和选择性胞内定位高度依赖于在异核双金属配合物中的金属物种。     

Multimodal Imaging and Phototherapy of Cancer and Bacterial Infection by Graphene and Related Nanocomposites

The advancements in nanotechnology and nanomedicine are projected to solve many glitches in medicine, especially in the fields of cancer and infectious diseases, which are ranked in the top five most dangerous deadly diseases worldwide by the WHO. There is great concern to eradicate these problems with accurate diagnosis and therapies. Among many developed therapeutic models, near infra-red mediated phototherapy is a non-invasive technique used to invade many persistent tumors and bacterial infections with less inflammation compared with traditional therapeutic models such as radiation therapy, chemotherapy, and surgeries. Herein, we firstly summarize the up-to-date research on graphene phototheranostics for a better understanding of this field of research. We discuss the preparation and functionalization of graphene nanomaterials with various biocompatible components, such as metals, metal oxides, polymers, photosensitizers, and drugs, through covalent and noncovalent approaches. The multifunctional nanographene is used to diagnose the disease with confocal laser scanning microscopy, magnetic resonance imaging computed tomography, positron emission tomography, photoacoustic imaging, Raman, and ToF-SMIS to visualize inside the biological system for imaging-guided therapy are discussed. Further, treatment of disease by photothermal and photodynamic therapies against different cancers and bacterial infections are carefully conferred herein along with challenges and future perspectives.     

Functionalized Ultrasmall Iron Oxide Nanoparticles for T1-Weighted Magnetic Resonance Imaging of Tumor Hypoxia

Hypoxia is a common biological condition in many malignant solid tumors that plays an imperative role in regulating tumor growth and impacting the treatment’s therapeutic effect. Therefore, the hypoxia assessment is of great significance in predicting tumor development and evaluating its prognosis. Among the plenty of existing tumor diagnosis techniques, magnetic resonance imaging (MRI) offers certain distinctive features, such as being free of ionizing radiation and providing images with a high spatial resolution. In this study, we develop a fluorescent traceable and hypoxia-sensitive T₁-weighted MRI probe (Fe₃O₄-Met-Cy5.5) via conjugating notable hypoxia-sensitive metronidazole moiety and Cy5.5 dye with ultrasmall iron oxide (Fe₃O₄) nanoparticles. The results of in vitro and in vivo experiments show that Fe₃O₄-Met-Cy5.5 has excellent performance in relaxivity, biocompatibility, and hypoxia specificity. More importantly, the obvious signal enhancement in hypoxic areas indicates that the probe has great feasibility for sensing tumor hypoxia via T₁-weighted MRI. These promising results may unlock the potential of Fe₃O₄ nanoparticles as T₁-weighted contrast agents for the development of clinical hypoxia probes.     

Non-Destructive Detection of Moldy Walnuts Based on Hyperspectral Imaging Technology

Walnuts with their shells are a popular agricultural product in China. However, mildew from growth can sometimes be processed into foods. It is difficult to visually determine which walnuts have mildew without breaking the shells. A non-destructive method for detecting walnuts with mildew was studied by combining spectral data with image information. A total of 120 “Lüling” walnuts with shells were used for the mildew experiment. The characteristics of the spectral data from six surfaces of all samples were collected in the range of 370–1042 nm on days 0, 15, and 30. The spectrum was pretreated using SNV, and the feature bands were extracted using PCA and modeled using a support vector machine (SVM). The results show that the overall classification accuracy was 93%, with an of accuracy of 100% for INEN walnuts (normal internally and externally). The accuracy for IMEM walnuts (mildew internally and externally) reached 87.29%. There was an accuracy of 78.6% for IMEN walnuts (mildew internally and normal externally). The non-destructive detection of mildewed walnuts can be undertaken using hyperspectral imaging technology, which provides a new technique for exploring the mechanisms of walnuts with mildew.     

Advanced Nanomaterials for Multimodal Molecular Imaging

The development of multimodal molecular imaging contrast agents based on versatile nanomaterials has recently attracted much attention in disease diagnosis and therapeutic delivery. Contrast agents made from nanoparticles and used for multimodal imaging in vivo provide a multidimensional pathophysiological overview of diseases. This review summarizes recently developed advanced nanomaterials for multimodal molecular imaging. We comprehensively discuss these nanoparticle contrast agents in terms of their targeting modalities, limitations in clinical translation and future directions.     

Impact of anisotropic slip on the stagnation-point flow past a stretching/shrinking surface of the Al_2O_3-Cu/H_2O hybrid nanofluid

The characteristics of heat transfer in the three-dimensional stagnationpoint flow past a stretching/shrinking surface of the Al₂O₃-Cu/H₂O hybrid nanofluid with anisotropic slip are investigated. The partial differential equations are converted into a system of ordinary differential equations by valid similarity transformations. The simplified mathematical model is solved computationally by the bvp4c approach in the MATLAB operating system. This solving method is...     

多种超分辨荧光成像技术比较和进展评述

所见即所得是生命科学研究的中心哲学,贯穿在不断认识单个分子、分子复合体、分子动态行为和整个分子网络的历程中.活的动态的分子才是有功能的,这决定了荧光显微成像在生命科学研究中成为不可替代的工具.但是当荧光成像聚焦到分子水平的时候,所见并不能给出想要得到的.这个障碍是由于受光学衍射极限的限制,荧光显微镜无法在衍射受限的空间...     

鼻腔结构异常及其矫正术后气流场改变的数值分析1)

鼻腔结构的改变将伴随鼻腔空气动力学特性改变,进而促使下鼻甲等发生自适应性变化。选取鼻中隔偏曲患者并行鼻中隔偏曲矫正术,部分行下鼻甲骨折外移术,将术前和术后患者行鼻腔CT 扫描,根据CT数据对鼻腔气道进行表面三维重建,运用计算流体动力学方法分析术前和术后鼻腔气道的空气动力学特征。通过研究发现,鼻腔结构矫正手术不是以双侧鼻腔气道容积对称为目的,而是应将整个鼻腔结构看作一个整体,尽可能地保护鼻腔的\绿化带",最终达到重塑鼻腔结构之目的,使鼻腔的生理功能恢复正常。     

Radiochemical Synthesis of 4-[18F]FluorobenzylAzide and Its Conjugation with EGFR-Specific Aptamers

Central nervous system tumors related to gliomas are of neuroectodermal origin and cover about 30% of all primary brain tumors. Glioma is not susceptible to any therapy and surgical attack remains one of the main approaches to its treatment. Preoperative tumor imaging methods, such as positron emission tomography (PET), are currently used to distinguish malignant tissue to increase the accuracy of glioma removal. However, PET is lacking a specific visualization of cells possessing certain molecular markers. Here, we report an application of aptamers to enhancing specificity in imaging tumor cells bearing the epidermal growth factor receptor (EGFR). Glioblastoma is characterized by increased EGFR expression, as well as mutations of this receptor associated with active division, migration, and adhesion of tumor cells. Since 2021, EGFR has been included into the WHO classification of gliomas as a molecular genetic marker. To obtain conjugates of aptamers GR20 and GOL1-specific to EGFR, a 4-[¹⁸F]fluorobenzylazide radiotracer was used as a synthon. For the production of the synthon, a method of automatic synthesis on an Eckert & Ziegler research module was adapted and modified using spirocyclic iodonium ylide as a precursor. Conjugation of 4-[¹⁸F]fluorobenzylazide and alkyne-modified aptamers was carried out using Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) with/without the TBTA ligand. As a result, it was possible to obtain ¹⁸F-labelled conjugates with 97% radiochemical purity for [¹⁸F]FB-GR20 and 98% for [¹⁸F]FB-GOL1. The obtained conjugates can be used for further studies in PET analysis on model animals with grafted glioblastoma.     

小分子基温敏聚合物纳米粒子的制备及在近红外二区荧光成像与光热治疗中的应用

以有机小分子4,9-二(5-9H-芴-2-基-噻吩-2-基)-6',7-联苯[1,2,5]噻二唑并[3,4-g]喹喔啉(TQF)为前驱体, 通过化学方法将其修饰为可引发可逆加成-断裂链转移聚合(RAFT)反应的小分子链转移剂TQF-苯基硫代链 转移剂（CTA）. 以TQF-CTA为链转移剂, 以偶氮二异丁腈为引发剂, 引发N-异丙基丙烯酰胺(NIPAAm)和 甲基丙烯酸寡聚乙二醇酯(OEGMA)发生RAFT聚合反应, 合成了具有良好水溶性和较低临界溶解温度(LCST)的小分子基共聚物[TQF-P(NIPAAm-co-OEGMA), TPNO]. 将其直接溶于水中可制备成温敏的球形纳米粒子 TPNO NPs. 研究结果表明, TPNO NPs在温度大于LCST(35 ℃)时表现出一个明显的粒径变化和显著的荧光 增强行为(2.2倍), 并成功实现了对活体小鼠血管与肿瘤的明亮近红外二区(NIR-Ⅱ)荧光成像(FI). 同时, TPNO NPs有着良好的光热转换效率(PCE=29.8%), 通过体外细胞实验证明了其对细胞具有较好的光热治疗(PTT)效果.