Facilely Fabricating F-Doped Fe3N Nanoellipsoids Grown on 3D N-Doped Porous Carbon Framework as a Preeminent Negative Material.

Transition metal nitride negative electrode materials with a high capacity and electronic conduction are still troubled by the large volume change in the discharging procedure and the low lithium ion diffusion rate. Synthesizing the composite material of F-doped Fe3N and an N-doped porous carbon framework will overcome the foregoing troubles and effectuate a preeminent electrochemical performance. In this study, we created a simple route to obtain the composite of F-doped Fe3N nanoellipsoids and a 3D N-doped porous carbon framework under non-ammonia atmosphere conditions. Integrating the F-doped Fe3N nanoellipsoids with an N-doped porous carbon framework can immensely repress the problem of volume expansion but also substantially elevate the lithium ion diffusion rate. When utilized as a negative electrode for lithium-ion batteries, this composite bespeaks a stellar operational life and rate capability, releasing a tempting capacity of 574 mAh g-1 after 550 cycles at 1.0 A g-1. The results of this study will profoundly promote the evolution and application of transition metal nitrides in batteries.

[Hyperosmotic stress and perfusion culture strategies increase the yield of recombinant adenoviral vector produced by HEK 293 cells].

With various diseases ravaging internationally, the demands for recombinant adenoviral vector (Adv) vaccines have increased dramatically. To meet the demand for Adv vaccine, development of a new cell culture process is an effective strategy. Applying hyperosmotic stress in cells before virus infection could increase the yield of Adv in batch culture mode. Emerging perfusion culture can significantly increase the yield of Adv as well. Therefore, combining the hyperosmotic stress process with perfusion culture is expected to improve the yield of Adv at high cell density. In this study, a shake flask combined with a semi-perfusion culture was used as a scaled-down model for bioreactor perfusion culture. Media with osmotic pressure ranging from 300 to 405 mOsm were used to study the effect of hyperosmotic stress on cell growth and Adv production. The results showed that using a perfusion culture process with a hyperosmotic pressure medium (370 mOsm) during the cell growth phase and an isosmotic pressure medium (300 mOsm) during the virus production phase effectively increased the yield of Adv. This might be due to the increased expression of HSP70 protein during the late phases of virus replication. The Adv titer in a bioreactor with such a process reached 3.2×1010 IFU/mL, three times higher than that of the traditional perfusion culture process. More importantly, this is the first time that a strategy of combining the hyperosmotic stress process with perfusion culture is applied to the production of Adv in HEK 293 cells. It also reveals the reason why the hyperosmotic stress process increased the yield of Adv, which may facilitate the process optimization of for producing other Adv in HEK 293 cells.

Highly [001]-oriented N-doped orthorhombic Nb2O5 microflowers with intercalation pseudocapacitance for lithium-ion storage.

Orthorhombic Nb2O5 (T-Nb2O5), a typical intercalation pseudocapacitor, is favorable for realizing high power and energy density for lithium-ion batteries; furthermore, the 2D layered channels perpendicular to the [001] direction facilitate fast Li+ intercalation in T-Nb2O5. Herein, N-doped T-Nb2O5 microflowers (N-Nb2O5) assembled from highly [001]-oriented nanoflakes are rationally synthesized using NH4F as the nitrogen source and capping agent. It is found that NH4+ can adsorb on the O-terminated (010) plane of T-Nb2O5via N-H⋯O hydrogen bonds, which is highly conducive to the generation of 1D nanorods and the subsequent fusion of the nanorods into highly [001]-oriented nanoflakes. The special growth orientation of the T-Nb2O5 nanoflakes endows them with abundant available Li+ intercalation channels; moreover, the bandgap of N-Nb2O5 is narrowed (∼2.91 eV) owing to the doping of N atoms, and the intrinsic electronic conductivity is improved. Accordingly, the intercalation pseudocapacitive behavior of N-Nb2O5 is notably promoted and N-Nb2O5 exhibits superior Li+ storage properties, including large discharge capacity (214.7 mA h g-1 at 1C), excellent rate capability (203.7 and 174.6 mA h g-1 at 1 and 20C), and superior cyclic stability (150.7 mA h g-1 at 10C after 1000 cycles). In addition, the LiNi0.5Mn0.3Co0.2O2//N-Nb2O5 full cell delivers outstanding Li+ storage performance, especially in terms of long-term cycling (126.2 mA h g-1 at 10C after 3500 cycles).

High rate capability performance of ordered mesoporous TiNb6O17 microsphere anodes for lithium ion batteries.

We report the synthesis and application of ordered mesoporous TiNb6O17 microspheres (M-TNO) using a one-step solvothermal method for the first time in lithium-ion batteries. The diameters of TiNb6O17 microspheres are in the range from 2.2 to 2.4 µm with a mesopore size of about 35 nm, which promotes the electron and ion migration in charge/discharge processes. M-TNO shows a high specific capacitance (307.2 mA h g-1) at a low current density of 0.2 C and a long-term cycle life over 500 cycles as an electrode. The retentive capacity of the batteries is 77% of the initial cycle after 500 cycles. It is worth noting that M-TNO exhibits excellent rate capacity, which decreases slowly from 265.7 to 172.4 mA h g-1 with the current density increasing from 1 C to 30 C. The retentive capacity at a current density of 30 C is 65% compared to that at 1 C.

Urchin-like hierarchical H-Nb2O5 microspheres: synthesis, formation mechanism and their applications in lithium ion batteries.

Urchin-like hierarchical Nb2O5 microspheres are successfully synthesized through a facile solvothermal method in glycerol-isopropanol mixed media followed by thermal treatment. The sample is characterized by XRD, FESEM, TEM, HRTEM, BET, and XPS, and the results reveal that the as-formed Nb2O5 microspheres have a pseudohexagonal structure and are composed of nanorods with an average diameter of ca. 20 nm. It is found that glycerol not only serves as a solvent but also acts as a reactant; furthermore, isopropanol plays an important part in the morphologies of the products. When used as anodic materials for lithium ion batteries, the Nb2O5 microspheres deliver initial discharge capacities of 201.7, 159.7, 148.5, 123.7, and 98.5 mA h g-1 at the current densities of 0.5, 1, 2, 5, and 10C, respectively. Additionally, the discharge capacity of Nb2O5 remains at 105.5 mA h g-1 even after 500 cycles at a high rate of 5C. The good electrochemical properties of the products may be ascribed to their large surface areas and hierarchical structures.

Expression and prognostic significance of VEGFR-2 in breast cancer.

Breast cancer is one of the most common cancers among women in the world. Vascular endothelial growth factor receptor 2 (VEGFR-2) was not only found to play a key role in the development of tumor angiogenesis, but has also been located in tumor cells of a variety of tumors. This study investigated the expression pattern of VEGFR-2 in breast cancer tissue specimens in order to evaluate the role of VEGFR-2 in the prognosis of breast cancer. Expression and localization of VEGFR-2 in tumor cells of breast cancer specimens from 98 invasive breast cancer patients were determined by immunohistochemistry. The relationships between VEGFR-2 expression and clinicopathological features were also analyzed. The results showed that VEGFR-2 expression correlated positively with lymph node (LN) metastasis of breast cancer. Patients with high expression of VEGFR-2 had a significantly worse OS. It was also observed that the expression of epithelial-mesenchymal transition (EMT) marker, including Twist1 and Vimentin, was higher in the tumors with higher VEGFR-2 expression, while the E-cadherin expression was lower in the same tumors, suggesting that VEGFR-2 may serve as a possible mediator of EMT in breast cancer.

Efficient three-photon luminescence with strong polarization dependence from a scintillating silicate glass co-doped with Gd3+ and Tb3+.

Efficient three-photon luminescence (3PL) from a scintillating silicate glass co-doped with Gd(3+) and Tb(3+) was generated by using a focused femtosecond laser beam at 800 nm. Four emission bands centered at 496, 541, 583, and 620 nm were identified as the electronic transitions between the energy levels of Tb(3+) followed by three-photon absorption (3PA) in Gd(3+) and Tb(3+) and the resonant energy transfer from Gd(3+) to Tb(3+). More interestingly, a strong polarization dependence of the 3PL was observed and it is ascribed to the polarization dependent 3PA in Gd(3+) and Tb(3+) and/or the angular distribution of photogenerated electrons in the glass.