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991.
Na Li Honggang Nie Liping Jiang Guihua Ruan Fuyou Du Huwei Liu 《Journal of separation science》2020,43(15):3146-3163
The structural information and spatial distribution of molecules in biological tissues are closely related to the potential molecular mechanisms of disease origin, transfer, and classification. Ambient ionization mass spectrometry imaging is an effective tool that provides molecular images while describing in situ information of biomolecules in complex samples, in which ionization occurs at atmospheric pressure with the samples being analyzed in the native state. Ambient ionization mass spectrometry imaging can directly analyze tissue samples at a fairly high resolution to obtain molecules in situ information on the tissue surface to identify pathological features associated with a disease, resulting in the wide applications in pharmacy, food science, botanical research, and especially clinical research. Herein, novel ambient ionization techniques, such as techniques based on spray and solid‐liquid extraction, techniques based on plasma desorption, techniques based on laser desorption ablation, and techniques based on acoustic desorption were introduced, and the data processing of ambient ionization mass spectrometry imaging was briefly reviewed. Besides, we also highlight recent applications of this imaging technology in clinical researches and discuss the challenges in this imaging technology and the perspectives on the future of the clinical research. 相似文献
992.
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994.
本文设计合成了两亲性Eu(Ⅲ)配合物(Eu L^3+)、两亲性香豆素衍生物(CA)以及荧光素修饰的透明质酸(HA-FA).Eu L^3+和CA可在水中共组装形成带正电荷的囊泡型荧光纳米界面(Eu L^3+/CA).HA-FA可通过静电引力络合在Eu L^3+/CA表面,促使CA与FA之间发生有效的荧光共振能量转移,体系的荧光发射以荧光素的绿色荧光为主.当肿瘤细胞标识物CD44蛋白与络合在囊泡表面上的透明质酸发生特异相互作用后,降低了CA与FA之间的能量转移效率,体系的荧光发射从绿色转变为蓝色.据此,实现了对CD44的高灵敏检测(DL=1.79×10^-7g/m L),而所测试的氨基酸、蛋白质等生物分子几乎不对荧光纳米界面的荧光性质产生影响.基于此,我们成功地将Eu L^3+/CA/HA-FA用于人乳腺癌细胞MCF-7和MDA-MB-231悬浮液中CD44蛋白的高效检测,该工作为构建新型CD44蛋白荧光探针提供了思路,为癌症早期诊断和治疗奠定了基础. 相似文献
995.
本研究以亲油性的双面胶作为基底,利用滴涂二乙炔单体结合紫外光聚合来制备均匀的聚二乙炔(PDA)薄膜,通过荧光和颜色两种信号变化模式(即"双模光学检测")研究了PDA薄膜对VOC气体的响应性,发现制备的PDA薄膜在2 min内就可以实现明显的荧光和颜色变化,有效解决了目前PDA薄膜在VOC气体检测方面存在响应速度慢、薄膜均一性差等问题.此外,为解决单一PDA薄膜的交叉响应性问题,本研究制备了四种不同的基于双面胶基底的PDA薄膜,并将制备的4种PDA薄膜集成到一片PDMS薄膜基底上来构建柔性的传感阵列,利用阵列的颜色变化结合模式识别技术,实现了对8种VOC气体的快速、灵敏区分.进一步将制备的PDA薄膜阵列用于健康人、模拟糖尿病及肾病患者呼出气体中VOC标志物的辨别和分析研究,发现可以将三类人的呼出气体清晰地区分,说明了该阵列在呼气疾病诊断中的应用前景.与目前报道的PDA薄膜阵列相比,本研究中基于双面胶基底的PDA薄膜阵列具有气体响应速度快、灵敏性高、柔韧性好、制备工艺简单、成本低、易于大规模制备等优点,有望用于实VOC气体检测研究中. 相似文献
996.
本文探讨了超微血管成像(SMI)和超声造影(CEUS)对乳腺癌病灶内微血流及超微血管的评价,及其联合检查对乳腺癌的诊断价值。选取2017年6月~2019年3月我院收治的经手术病理证实的乳腺癌患者106例(106个肿块)作为研究对象,所有患者术前均完成彩色多普勒血流显像(CDFI)、CEUS及SMI检查。比较SMI、CEUS对乳腺癌的诊断准确率及对病灶内血流信号、穿支血管的显示情况。结果显示,106例乳腺癌(106个肿块)中,SMI和CEUS对乳腺癌的诊断准确率分别为79.25%、83.96%,两者比较差异无统计学意义(P>0.05);SMI联合CEUS检查对乳腺癌的诊断准确率为96.23%,明显高于单一SMI或CEUS的诊断准确率(P<0.05)。在血流信号显示上,SMI检出不丰富血流信号、丰富血流信号分别为64个、42个;CEUS表现为低增强64个、等增强及高增强为42个;SMI和CEUS评价乳腺癌病灶内微血管及血流供应情况具有较好的一致性(P<0.05)。在穿支血管显示上,SMI检出44个、CDFI检出34个,SMI能够清晰检出CDFI不能检出的穿支血管10个。表明SMI和CEUS诊断乳腺癌病灶内微血管及血流供应情况具有较好的一致性,对乳腺癌均有较高的诊断价值,二者联合检查有助于提高乳腺癌的诊断准确率。 相似文献
997.
Herein, we report an approach to combat counterfeiting and storage of valuable information based on the solid‐state fluorescence switching behavior of isoniazid functionalized naphthalene diimide (ISO_NDI) in response to an external stimuli (i. e., HCl vapor). The unique feature of ISO_NDI is further utilized to develop an invisible ink (ISO_NDI‐PVA) with commercial polymer polyvinyl alcohol (PVA). A solid‐state fluorescence recovery was observed while loading with HCl vapors. This exclusive property of the material could be applied directly as a security ink for confidential data storage purpose. Based on above strategy, we successfully realized the rewritable application by using ISO_NDI‐PVA ink and confirm its practical efficacy on various substrates by creating different patterns. The solid‐state fluorescence switching behavior of ISO_NDI‐PVA ink exhibited reversible on/off signal for multiple cycles under the influence of HCl/NH3 vapors. Mechanistic investigation supports a clear participation of intermolecular charge transfer (ICT) phenomenon in the solid‐state fluorescence switching property. The ease of fabricating the ink with invisible to visible characteristics in response to HCl vapors provides new opportunities for exploring the application of ISO_NDI‐PVA as invisible ink for targeted security applications. 相似文献
998.
Jakkapan Kumsampao Chaiyon Chaiwai Pongsakorn Chasing Thanyarat Chawanpunyawat Supawadee Namuangruk Taweesak Sudyoadsuk Vinich Promarak 《化学:亚洲杂志》2020,15(19):3029-3036
Despite the success of thermally activated delayed fluorescent (TADF) materials in steering the next generation of organic light‐emitting diodes (OLEDs), effective near infrared (NIR) TADF emitters are still very rare. Here, we present a simple and extremely high electron‐deficient compound, 5,6‐dicyano[2,1,3]benzothiadiazole (CNBz), as a strong electron‐accepting unit to develop a sufficiently strong donor‐acceptor (D?A) interaction for NIR emission. End‐capping with the electron‐donating triphenylamine (TPA) unit created an effective D?A?D type system, giving rise to an efficient NIR TADF emissive molecule (λem=750 nm) with a very small ΔEST of 0.06 eV. The electroluminescent device using this NIR TADF emitter exhibited an excellent performance with a high maximum radiance of 10020 mW Sr?1 m?2, a maximum EQE of 6.57% and a peak wavelength of 712 nm. 相似文献
999.
《Arabian Journal of Chemistry》2020,13(12):8697-8707
A dipodal fluorescent probe 3, with imine and hydroxyl moieties as binding sites, has been synthesized and characterized with spectroscopic methods, single-crystal X-ray techniques, and DFT. The synthesized probe 3 (φ = 0.0028) showed highly sensitive and highly specific fluorescent ‘turn-on’ effect (λem = 453 nm) for the 1:1 binding with Fe3+ ions to form probe 3.Fe3+ complex (φ = 0.203) in semi-aqueous medium (acetonitrile:water (50:50; v/v)) and live cells. The 1:1 binding stoichiometry of probe 3 and Fe3+ ions was proposed by DFT calculations and confirmed by the NMR spectroscopy, crystal structures of probe 3 and 3.Fe3+ complex, and mass spectrum of probe 3.Fe3+ complex. The stability of probe 3.Fe3+ complex in a wide pH range (pH 2–12) and reversibility for binding with Fe3+ ions in the presence of EDTA indicates that it can be an effective chemosensor for the detection of Fe3+ ions in various samples, including living cells. Importantly, with the LOD of 21.5 nM for the detection of Fe3+ ions, probe 3 did not show any interference from potentially competing ions even at a 1:3 ratio, indicates its biocompatibility. The nanomolar limit of detection (21.5 nM), cell permeability, and low cytotoxicity allows the probe 3 to be an excellent tool for the live-cell imaging and detection of ferric ions in live cells. 相似文献
1000.
In this paper, β -Cyclodextrin (β -CD) was used to study the interaction of berberine with DNA by the means of absorption spectrum and fluorescence spectrum. Experimental results showed that it was the isoquinolinic part that intercalated into the DNA double helix. And the value of the intrinsic binding constant K was 4.5 × 103l/mol in the presence of β -CD and 1.1 × 104l/mol in the absence of β -CD. 相似文献