In spite of the current prevalence of the CVD-based processes, the electric arc remains an interesting process for the synthesis of carbon nanoforms, thanks to its versatility, robustness and easiness. It also allows ...In spite of the current prevalence of the CVD-based processes, the electric arc remains an interesting process for the synthesis of carbon nanoforms, thanks to its versatility, robustness and easiness. It also allows performing in-situ substitution of carbon atoms by hetero-elements in the graphene lattice. Our work aims to establish a correlation between the plasma properties, type and chemical composition (and the substitution rate) of the obtained single-wall carbon nan- otubes. The plasma was characterized by optical emission spectroscopy and the products were analyzed by high resolution transmission electron microscopy and core level Electron Energy-Loss Spectroscopy (EELS). Results show that a high boron content leads to a plasma temperature decrease and hinders the formation of nanotubes. This effect can be compensated by increasing the arc current and/or yttrium content. The optimal conditions for the synthesis of boron- and/or nitrogen-substituted nanotubes correspond to a high axial plasma temperature associated to a strong radial gradient. EELS analysis confirmed that the boron incorporates into the graphenic lattice.展开更多
Objective:Although great progress has been made in the field of siRNA gene therapy,safe,efficient,and targeted delivery of siRNA are still major challenges in siRNA therapeutics.Methods:We developed an up-conversion n...Objective:Although great progress has been made in the field of siRNA gene therapy,safe,efficient,and targeted delivery of siRNA are still major challenges in siRNA therapeutics.Methods:We developed an up-conversion nanoparticle-based nanocage system.This system protected the siRNA from being degraded by nucleases in organisms and selectively delivered the siRNAs to the tumor sites,due to modifications of targeted molecules on the surfaces of nanocages and local inhalation.Results:The siRNAs delivered by the up-conversion nanoparticle nanocages were protected from degradation in transit to the tumor sites,where they accumulated.Compared with the passive target and control groups,the up-conversion nanoparticles based on the nanocage system showed a tumor suppressive effect after approximately 3 weeks of treatment.Conclusions:The up-conversion nanoparticle nanocages efficiently delivered vascular endothelial growth factor siRNAs to tumor sites.Mice with lung tumors treated with tumors targeting up-conversion nanoparticle nanocages showed steady body weight changes,high tumor inhibition ratios,and longer survival times.展开更多
Strain engineering provides an effective mean of tuning the fundamental properties of semiconductors for electric and optoelectronic applications. Here we report on how the applied strain changes the emission properti...Strain engineering provides an effective mean of tuning the fundamental properties of semiconductors for electric and optoelectronic applications. Here we report on how the applied strain changes the emission properties of hetero- structures consisting of different crystalline phases in the same CdS nanobelts. The strained portion was found to produce an additional emission peak on the low-energy side that was blueshifted with increasing strain. Furthermore, the additional emission peak obeyed the Varshni equation with temperature and exhibited the band-filling effect at high excitation power. This new emission peak may be attributed to spatially indirect exciton recombination between different crystalline phases of CdS. First-principles calculations were performed based on the spatially indirect exciton recombination, and the calculated and experimental results agreed with one another. Strain proved to be capable of enhancing the anti-Stokes emission, suggesting that the efficiency of laser cooling may be improved by strain engineering.展开更多
The development of high-resolution nanosized photoacoustic contrast agents is an exciting yet challenging technological advance. Herein, antibody (breast cancer-associated antigen I (Brcaal) monoclonal antibody)- ...The development of high-resolution nanosized photoacoustic contrast agents is an exciting yet challenging technological advance. Herein, antibody (breast cancer-associated antigen I (Brcaal) monoclonal antibody)- and peptide (RGD)- functionalized gold nanoprisms (AuNprs) were used as a combinatorial methodology for in situ photoacoustic imaging, angiography, and localized hyperthermia using orthotopic and subcutaneous murine gastric carcinoma models. RGD-conjugated PEGylated AuNprs are available for tumor angiography, and Brcaal monodonal antibody-conjugated PEGylated AuNprs are used for targeting and for in situ imaging of gastric carcinoma in orthotopic tumor models. In situ photoacoustic imaging allowed for anatomical and functional imaging at the tumor site. In vivo tumor angiography imaging showed enhancement of the photoacoustic signal in a time-dependent manner. Furthermore, photoacoustic imaging demonstrated that tumor vessels were clearly damaged after localized hyperthermia. This is the first proof-of-concept using two AuNprs probes as highly sensitive contrasts and therapeutic agents for in situ tumor detection and inhibition. These smart antibody/peptide AuNprs can be used as an efficient nanotheranostic platform for in vivo tumor detection with high sensitivity, as well as for tumor targeting therapy which, with a single-dose injection, results in tumor size reduction and increases mice survival after localized hyperthermia treatment.展开更多
文摘In spite of the current prevalence of the CVD-based processes, the electric arc remains an interesting process for the synthesis of carbon nanoforms, thanks to its versatility, robustness and easiness. It also allows performing in-situ substitution of carbon atoms by hetero-elements in the graphene lattice. Our work aims to establish a correlation between the plasma properties, type and chemical composition (and the substitution rate) of the obtained single-wall carbon nan- otubes. The plasma was characterized by optical emission spectroscopy and the products were analyzed by high resolution transmission electron microscopy and core level Electron Energy-Loss Spectroscopy (EELS). Results show that a high boron content leads to a plasma temperature decrease and hinders the formation of nanotubes. This effect can be compensated by increasing the arc current and/or yttrium content. The optimal conditions for the synthesis of boron- and/or nitrogen-substituted nanotubes correspond to a high axial plasma temperature associated to a strong radial gradient. EELS analysis confirmed that the boron incorporates into the graphenic lattice.
基金supported by the National Key Basic Research Program(973 Project)(Grant Nos.2015CB931802 and 2017FYA0205301)the Special Fund for Science and Technology Innovation of Shanghai Jiao Tong University(Grant Nos.YG2017MS70,YG2015MS62,and AF0300179)+3 种基金the Shanghai Municipal Bureau of Economy and Information Technology(Grant No.XC-ZXSJ-02-2016-05)the National Natural Scientific Foundation of China(Grant Nos.8202010801,81921002,81225010,81028009,and 31170961)the 863 Project of China(Grant No.2014AA020700)and the Shanghai Science and Technology Fund(Grant No.13NM1401500)。
文摘Objective:Although great progress has been made in the field of siRNA gene therapy,safe,efficient,and targeted delivery of siRNA are still major challenges in siRNA therapeutics.Methods:We developed an up-conversion nanoparticle-based nanocage system.This system protected the siRNA from being degraded by nucleases in organisms and selectively delivered the siRNAs to the tumor sites,due to modifications of targeted molecules on the surfaces of nanocages and local inhalation.Results:The siRNAs delivered by the up-conversion nanoparticle nanocages were protected from degradation in transit to the tumor sites,where they accumulated.Compared with the passive target and control groups,the up-conversion nanoparticles based on the nanocage system showed a tumor suppressive effect after approximately 3 weeks of treatment.Conclusions:The up-conversion nanoparticle nanocages efficiently delivered vascular endothelial growth factor siRNAs to tumor sites.Mice with lung tumors treated with tumors targeting up-conversion nanoparticle nanocages showed steady body weight changes,high tumor inhibition ratios,and longer survival times.
文摘Strain engineering provides an effective mean of tuning the fundamental properties of semiconductors for electric and optoelectronic applications. Here we report on how the applied strain changes the emission properties of hetero- structures consisting of different crystalline phases in the same CdS nanobelts. The strained portion was found to produce an additional emission peak on the low-energy side that was blueshifted with increasing strain. Furthermore, the additional emission peak obeyed the Varshni equation with temperature and exhibited the band-filling effect at high excitation power. This new emission peak may be attributed to spatially indirect exciton recombination between different crystalline phases of CdS. First-principles calculations were performed based on the spatially indirect exciton recombination, and the calculated and experimental results agreed with one another. Strain proved to be capable of enhancing the anti-Stokes emission, suggesting that the efficiency of laser cooling may be improved by strain engineering.
基金This work was supported by the National Basic Research Program of China (No. 2015CB931802), National Natural Science Foundation of China (Nos. 81225010, 81327002, 31170961, 20771075, and 20803040), the National High-tech R&D Program of China (No. 2014AA020700), and Special project for nanotechnology from Shanghai (Nos. 13NM1401500 and 15DZ2252000).
文摘The development of high-resolution nanosized photoacoustic contrast agents is an exciting yet challenging technological advance. Herein, antibody (breast cancer-associated antigen I (Brcaal) monoclonal antibody)- and peptide (RGD)- functionalized gold nanoprisms (AuNprs) were used as a combinatorial methodology for in situ photoacoustic imaging, angiography, and localized hyperthermia using orthotopic and subcutaneous murine gastric carcinoma models. RGD-conjugated PEGylated AuNprs are available for tumor angiography, and Brcaal monodonal antibody-conjugated PEGylated AuNprs are used for targeting and for in situ imaging of gastric carcinoma in orthotopic tumor models. In situ photoacoustic imaging allowed for anatomical and functional imaging at the tumor site. In vivo tumor angiography imaging showed enhancement of the photoacoustic signal in a time-dependent manner. Furthermore, photoacoustic imaging demonstrated that tumor vessels were clearly damaged after localized hyperthermia. This is the first proof-of-concept using two AuNprs probes as highly sensitive contrasts and therapeutic agents for in situ tumor detection and inhibition. These smart antibody/peptide AuNprs can be used as an efficient nanotheranostic platform for in vivo tumor detection with high sensitivity, as well as for tumor targeting therapy which, with a single-dose injection, results in tumor size reduction and increases mice survival after localized hyperthermia treatment.