Unveiling the correlation between non‐diffracting tractor beam and its singularity in Poynting vector

This paper investigates the singular optics of nonparaxial light beams in the near field when the light behaves as a tractor beam. New insights into the optical pulling force, which is usually represented by integrating the stress tensor at a black box enclosing the object, are interpreted by the optical singularity of the Poynting vector. The negative nonconservative pulling force originates from the transfer of the azimuthal Poynting vector to the longitudinal component partly owing to the presence of a scatterer. The separatrice pattern and singularity shifts of the Poynting vector unanimously exhibit a differentiable near‐field distribution in the presence of optical pulling force. A new method is established to calculate the near‐field optical force using the differential Poynting vector in the far field. The results obtained provide a clear physical interpretation of the light–matter interaction and manifest the significance of singular optics in manipulating objects.

     

Recent research advances of the biomimetic tumor microenvironment and regulatory factors on microfluidic devices: A systematic review

Tumor microenvironment is a multicomponent system consisting of tumor cells, noncancer cells, extracellular matrix, and signaling molecules, which hosts tumor cells with integrated biophysical and biochemical elements. Because of its critical involvement in tumor genesis, invasion, metastasis, and resistance, the tumor microenvironment is emerging as a hot topic of tumor biology and a prospective therapeutic target. Unfortunately, the complex of microenvironment modeling in vitro is technically challenging and does not effectively generalize the local tumor tissue milieu. Recently, significant advances in microfluidic technologies have provided us with an approach to imitate physiological systems that can be utilized to mimic the characterization of tumor responses with pathophysiological relevance in vitro. In this review, we highlight the recent progress and innovations in microfluidic technology that facilitates the tumor microenvironment study. We also discuss the progress and future perspective of microfluidic bionic approaches with high efficiency for the study of tumor microenvironment and the challenges encountered in cancer research, drug discovery, and personalized therapy.     

有序介孔材料: 历史、 现状与发展趋势

有序介孔材料是指孔径在2~50 nm之间的多孔材料, 是一类具有均匀孔径、 高有序度纳米孔道和高比表面积的新材料. 在过去30年里, 有序介孔材料的研究取得了长足的进步, 在可控合成、 结构设计和调控及功能化等方面形成了系统的理论. 同时, 其应用领域也不断被拓展, 包括能源存储与转化、 催化、 生物医药和传感等方面. 本文首先回顾了有序介孔材料的发展历史, 简要介绍发展过程中“里程碑式”的研究工作; 然后根据构效关系总结了其在不同领域应用的最新进展; 最后讨论了有序介孔材料领域进一步发展所面临的挑战与机遇, 并对未来前景进行了展望.     

Secondary Metabolites of Clinacanthus nutans

Chemistry of Natural Compounds -     

A New Ketone Derivative from Victoria amazonica

Chemistry of Natural Compounds - A new ketone, vicamazone (4-(2-butoxyethoxy)-4-methylpentan-2-one) (1), was isolated from the leaves of Victoria amazonica (Nymphaeaceae). The structure of the new...     

Seco-Abietanoids from Cryptomeria japonica and Their Inhibitory Activity Toward Xanthine Oxidase

Chemistry of Natural Compounds - A new seco-abietanoid, 12-methoxy-7-oxo-6,7-secoabieta-8,11,13-trien-6-oic acid (1), and a known seco-abietanoid,12-hydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial...     

A Novel Biphenyl Derivative from Cinnamomum insulari-montanum

Chemistry of Natural Compounds - A novel biphenyl derivative, insularione (3,3′,4,4′,6-pentahydroxy-3,4-dihydro-[1,1′-biphenyl]-2,5-dione) (1), was isolated from the stems of...     

Simulation of nuclide migration in a middle- and low-level radioactive waste repository based on GMS

Journal of Radioanalytical and Nuclear Chemistry - Groundwater is the most important factor contributing to the diffusion and migration of radionuclides in the repository. In this paper, the...     

一类肝靶向含钆大环磁共振对比剂的设计、制备与性能表征

肝靶向磁共振对比剂有助于肝细胞癌的早期诊断, 目前临床使用的线性对比剂存在导致病人肾源性系统性纤维化和钆离子沉积的风险. 本工作设计制备了一类含有乙氧芳基或甲氧苯基亲脂性基团、以DOTA-酰肼(DOTA: 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid)为Gd³⁺离子螯合基团的大环类磁共振对比剂. 0.5 T磁场下测得其纵向弛豫率r₁值介于3.7~5.4 L•mmol^-1•s^-1, 优于临床使用对比剂Gd-DOTA, 弛豫率最高的为对比剂7h (Gd-DOTAH-EOPEI) (EOPEI: 1-(4-ethoxyphenyl)ethanimine), 略高于临床使用肝靶向对比剂Gd-EOB-DTPA (EOB: ethoxybenzyl; DTPA: diethylenetriaminepentaacetic acid), 比我们前期制得的肝靶向磁共振对比剂5d提高了约15%. 动物活体体内肝靶向磁共振成像研究显示, 所制备对比剂7b、7g和7h具有作为肝靶向磁共振对比剂的应用潜力. 结合弛豫率和活体体内成像数据, 筛选出了先导化合物7h.     

臭氧氧化法合成全羟基葫芦[6]脲

葫芦脲(CB[n])的直接衍生化一直是一项难题。本文用臭氧氧化法将CB[6]衍生化,合成全羟基葫芦[6]脲((OH)12CB[6])。CB[6]与O3在20℃下反应 22h,生成(OH)12CB[6]的产率为44%,并探究了丙酮扩散法、柱层析法和DMSO提纯法三种去除无机盐的方法的可行性。臭氧由电解水制得,成本低,没有二次污染,且臭氧氧化能力强,在室温下即可氧化葫芦脲。本文为合成全羟基葫芦脲提供了新的方法。