Controlled PEGylation of periodic mesoporous organosilica nanospheres for improving their stability in physiological solutions

Thioether-bridged PMO nanospheres are synthesized and modified with different molecular weighted polyethylene glycol (PEG) via click reaction for the irst time. This work provides important method and knowledge to guide the modification of PMO for biomedical applications.     

Near‐Infrared‐Light‐Induced Fast Drug Release Platform: Mesoporous Silica‐Coated Gold Nanoframes for Thermochemotherapy

Development of advanced theranostics for personalized medicine is of great interest. Herein, a multifunctional mesoporous silica‐based drug delivery carrier has been developed for efficient chemo/photothermal therapy. The unique Au nanoframes@mSiO₂ spheres are elaborately prepared by utilizing Ag@mSiO₂ yolk–shell spheres as the template through spatially confined galvanic replacement method. Compared with the Ag@mSiO₂ yolk–shell spheres, the resultant Au nanoframes@mSiO₂ spheres show a strong and broad near‐infrared (NIR) absorbance in the 550–1100 nm region, high surface areas, and good biocompatibility. When irradiated with a NIR laser with a power intensity of 1 W cm^?2 at 808 nm, they can become highly localized heat sources through the photothermal effect. Moreover, the photothermal effect of the Au nanoframes can significantly promote the fast release of doxorubicin. The in vitro studies show obvious synergistic effects combining photothermal therapy and chemotherapy in the Au nanoframes@mSiO₂ spheres against Hela cells. It is believed that the as‐obtained multifunctional vehicles provide a promising platform for the combination of hyperthermia and chemotherapy for cancer treatment application.     

吡嗪-2,3-二羧酸铈的合成及其对聚氯乙烯热稳定性的作用

以吡嗪-2,3-二羧酸为配体,氨水,硝酸镧为原料,制备吡嗪-2,3-二羧酸铈。经FTIR、元素分析和TG-DSC等方法表征,确定其分子结构和分子式Ce₂(C₆N₂O₄)₂(NO₃)₂·5H₂O。通过静态热稳定实验研究吡嗪-2,3-二羧酸铈的热稳定性和硬脂酸钙、硬脂酸锌等辅助类热稳定剂的热稳定性。为了提高配合物的热稳定性,将配合物与硬脂酸锌、季戊四醇进行二元复配和三元复配,并进行热稳定性分析。结果表明：当吡嗪-2,3-二羧酸铈、硬脂酸锌和季戊四醇的质量比为2:1:2时,其热稳定时间为39 min,并且抗变色性有了较大提高。吡嗪-2,3-二羧酸铈能够减缓聚氯乙烯（PVC）中HCl气体的产生,并且吸收PVC降解产生的Cl^-,与稀土离子结合生成CeCl₃,从而抑制PVC的降解,起到热稳定作用。     

掺杂元素对铈锆固溶体性能的影响

用共沉淀法制备了CeZr,CeYZr,LBCeZr,LaCePrZr,LaCePrYZr和LaCePr固溶体,并对样品进行了XRD,BET,OSC以及催化性能测试和分析,表明所制备的固溶体全部为立方相结构,少量掺杂Y可以提高固溶体的比表面积和热稳定性;少量掺杂La也可以提高固溶体的热稳定性,但掺杂量过大时固溶体的比表面积和热稳定性均下降;用包头稀土矿提Nd后的LaCePr富集物制备的LaCePrZr和LaCePrYZr固溶体也具有较大比表面积和较好热稳定性.同时也采用浸渍法用Al2O3和SiO2对CeZr固溶体进行了包覆,CeZr固溶体包覆Al2O3和SiO2后比表面积和老化后的比表面积都有很大的提高.     

PPT课件运行的窘境及解决方法

目前,PPT因为简单、便捷而成为制作课件的首选软件。但是纵观众多的PPT课件,笔者发现它与Flash动画、视频等整合得不是很好,在运行时会遇到以下的一些窘境。下面就分述PPT课件运行的窘境及解决方法。     

Silicon multi‐meta‐holograms for the broadband visible light

The dielectric metasurface hologram promises higher efficiencies due to lower absorption than its plasmonic counterpart. However, it has only been used, up to now, for controlling linear‐polarization photons to form single‐plane holographic images in the near‐infrared region. Here, we report a transmission‐type metahologram achieving images in three colors, free from high‐order diffraction and twin‐image issues, with 8‐level modulation of geometric phase by controlling photon spin via precisely patterned Si nanostructures with varying orientations. The resulting real and virtual holographic images with spin dependence of incident photons natively enable the spin degeneracy removal of light, leading to a metahologram‐enabled spin Hall effect of light. Low‐absorption dielectrics also enable us to create holograms for short‐wavelength light down to 480 nm, thus spanning the three primary colors. It possesses the potential for compact color‐display chips using mature semiconductor processes, and holds significant advantages over previous metaholograms operating at longer wavelengths.

     

包头矿碳酸钠焙烧反应动力学研究

采用热重－差热、Ｘ射线衍射及化学及分析等方法，对包头矿添加１５％碳酸钠焙烧反应进行了研究。在６２３－７４１Ｋ，稀土氟碳酸盐首先分解为ＲＥＯＦ；在８５３－９２８Ｋ，稀土磷酸盐与碳酸钠反应分解为ＲＥ２Ｏ３，并生成Ｃａ８Ｎｄ２（ＰＯ４）６Ｏ２。     

关于Getz-Jacobson方法的若干讨论

考虑一类右端函数为多项式情形的常微分方程组初值问题的奇异性.先指出Getz-Jacobson所提出的代数方法的某些不足,然后提出一个新的方法,使得更加方便地讨论此类问题解的爆破性质.最后应用这种方法成功地解决了来自化学反应的一个实例.     

Stiffness-Transformable Nanoplatforms Responsive to the Tumor Microenvironment for Enhanced Tumor Therapeutic Efficacy

Herein, we report, for the first time, a unique stiffness-transformable manganese oxide hybridized mesoporous organosilica nanoplatform (MMON) for enhancing tumor therapeutic efficacy. The prepared MMONs had a quasi-spherical morphology and were completely transformed into soft bowl-like nanocapsules in the simulated tumor microenvironment through the breakage of Mn−O bonds, which decreased their Young's modulus from 165.7 to 84.5 MPa. Due to their unique stiffness transformation properties, the MMONs had reduced macrophage internalization, improved tumor cell uptake, and enhanced penetration of multicellular spheroids. In addition, in vivo experiments showed that the MMONs displayed a 3.79- and 2.90-fold decrease in non-specific liver distribution and a 2.87- and 1.83-fold increase in tumor accumulation compared to their soft and stiff counterparts, respectively. Furthermore, chlorin e6 (Ce6) modified MMONs had significantly improved photodynamic therapeutic effect.