Hypomorphic mutations which lead to decreased function of the NBS1 gene are responsible for Nijmegen breakage syndrome, a rare autosomal recessive hereditary disorder that imparts an increased predisposition to development of malignancy. The NBS1 protein is a component of the MRE11/ RAD50/NBS1 complex that plays a critical role in cellular responses to DNA damage and the maintenance of chromosomal integrity. Using small interfering RNA transfection, we have knocked down NBS1 protein levels and analyzed relevant phenotypes in two closely related human lymphoblastoid cell lines with different p53 status, namely wild-type TK6 and mutated WTK1. Both TK6 and WTK1 cells showed an increased level of ionizing radiation-induced mutation at the TK and HPRT loci, impaired phosphorylation of H2AX (;-H2AX), and impaired activation of the cell cycle checkpoint regulating kinase, Chk2. In TK6 cells, ionizing radiationinduced accumulation of p53/p21 and apoptosis were reduced. There was a differential response to ionizing radiation-induced cell killing between TK6 and WTK1 cells after NBS1 knockdown; TK6 cells were more resistant to killing, whereas WTK1 cells were more sensitive. NBS1 deficiency also resulted in a significant increase in telomere association that was independent of radiation exposure and p53 status. Our results provide the first experimental evidence that NBS1 deficiency in human cells leads to hypermutability and telomere associations, phenotypes that may contribute to the cancer predisposition seen among patients with this disease. (Cancer Res 2005; 65(13): 5544-53)

Li-CO batteries are promising energy storage systems by utilizing CO at the same time, though there are still some critical barriers before its practical applications such as high charging overpotential and poor cycling stability. In this work, iridium/carbon nanofibers (Ir/CNFs) are prepared via electrospinning and subsequent heat treatment, and are used as cathode catalysts for rechargeable Li-CO batteries. Benefitting from the unique porous network structure and the high activity of ultrasmall Ir nanoparticles, Ir/CNFs exhibit excellent CO reduction and evolution activities. The Li-CO batteries present extremely large discharge capacity, high coulombic efficiency, and long cycling life. Moreover, free-standing Ir/CNF films are used directly as air cathodes to assemble Li-CO batteries, which show high energy density and ultralong operation time, demonstrating great potential for practical applications.

Rechargeable Li-O batteries have aroused much attention for their high energy density as a promising battery technology; however, the performance of the batteries is still unsatisfactory. Lithium anodes, as one of the most important part of Li-O batteries, play a vital role in improving the cycle life of the batteries. Now, a very simple method is introduced to produce a protective film on lithium surface via chemical reactions between lithium metals and 1,4-dioxacyclohexane. The film is mainly composed of ethylene oxide monomers and endows Li-O batteries with enhanced cycling stability. The film could effectually reduce the morphology changes and suppress the parasitic reactions of lithium anodes. This simple approach provides a new strategy to protect lithium anodes in Li-O batteries.

The effect of steady-state increases in abdominal pressure (Pab) on cardiac performance was studied in seven acutely instrumented swine with pneumoperitoneum (PP). The animal was placed on volume-preset ventilation, and PP was created by air insufflation. Cardiac output (CO), right atrial (Pra), left atrial (Pla), pericardial (Ppe), and abdominal inferior vena cava pressures (Pivc) were measured while Pab was increased from baseline to 7.5, 15, and 30 mmHg (PP7.5, PP15, and PP30, respectively). Cardiac function curves of the right and left ventricle (RV and LV, respectively) were compared between baseline and PP30. CO presented biphasic changes, with an inital slight increase at PP7.5 followed by a fall at PP30. A significant discrepancy was observed between Pra and Pivc at PP15 and PP30, consistent with development of a "vascular waterfall." Transmural Pla (Pla - Ppe) showed parallel changes with CO, whereas transmural Pra (Pra - Ppe) exhibited a sustained increase. The RV cardiac-function curve was more depressed than was that of the LV at PP30; this suggests an increased RV afterload produced by the elevated airway pressure. These results support the hypothesis that our previously proposed concept of abdominal vascular zone conditions (M. Takata, R. A. Wise, and J. L. Robotham. J. Appl. Physiol. 69: 1961-1972, 1990) is also applicable to steady-state hemodynamic analyses. The abdominal zones appear to play an important role in determining CO, with increases in Pab, by modulating systemic venous return and the LV preload. Simultaneous measurements of Pra and Pivc may provide useful information in the hemodynamic care of patients with elevated Pab.

HIGHLIGHTS• A novel method is developed to prepare bifunctional oxygen electrocatalysts composed of Co nanoparticles and highly dispersed Fe loaded on N-doped carbon substrates by virtues of metal-organic frameworks and two different doping processes.• The designed catalysts show comparable performance with commercial catalysts. Meanwhile, rechargeable Zn-air batteries with prepared catalysts demonstrate high peak power density and good cycling stability.• The performance promotion originates from the synergy between Co nanoparticles and highly dispersed Fe, porous structures, large specific areas, and distinct three-dimensional carbon networks.

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Li 3 N. Subsequently, ethanolysis between Li 3 N and ethanol occurs to produce NH 3 . Recently, Zhang and co-workers have realized the electrochemical reduction of N 2 to NH 3 under ambient conditions with Au nanorods as electrocatalysts, [7] and a renewable energy storage system using N 2 /NH 3 cycle has been successfully designed.In recent years, inspired by rapidly developed metal-gas batteries, such as Li-O 2 batteries, [8,9] Li-CO 2 batteries, [10][11][12][13] Na-CO 2 batteries, [14,15] Al-CO 2 batteries, [16,17] and Li-SO 2 batteries, [18,19] Zhang and co-workers have realized reversible nitrogen fixation through Li-N 2 batteries. [20] The batteries have similar structure to other metal-gas batteries, with a lithium anode, an organic electrolyte, and a carbon air cathode. This battery demonstrates a promising electrochemical energy storage system. The reversible reaction of N 2 in this system was preliminarily described as follows: 6Li + N 2 ⇆ 2Li 3 N. In their work, the Li-N 2 battery is not only an energy storage device but also an efficient reversible nitrogen electroreduction platform.Since first reported in 1998, [21] the electrochemical synthesis of NH 3 has been developed in many ways. Many catalysts have been applied into this system. [22][23][24][25][26][27][28] Matanovic and Garzon studied the nitrogen electroreduction on molybdenum carbide through density functional theory (DFT) computations, [29] and Mo 2 C nanodots were successfully applied to electrochemical N 2 fixation. [30] For an excellent air cathode, the electrical conductivity as well as the surface area must be taken into consideration. According to a previous report, [31] nitrogen-doped carbon nanosheets have not only excellent electrical conductivity but also macrochannels and mesopores which could help the transportation of electrons and hold amounts of discharge products. [31] Therefore, this material is an ideal carbon substrate for Mo 2 C.Herein, we prepared ultrasmall Mo 2 C particles on N-doped carbon nanosheets (Mo 2 C/NC) as air cathodes for Li-N 2 batteries. One hand, Mo 2 C could act as an effective electrocatalyst for nitrogen reduction. On the other hand, the carbon substrate has microchannels and mesopores to store discharge products. The Li-N 2 batteries with Mo 2 C/N-doped carbon cathodes show an excellent electrochemical performance and realize reversible electroreduction of nitrogen.The morphology of Mo 2 C/NC was characterized by scanning electron microscope (SEM) and transmission electron N 2 fixation is a challenging and rewarding issue. However, the traditional Haber-Bosch process consumes a large amount of fossil fuels, resulting in serious environmental pollution. Instead, N 2 electroreduction is a promising way to convert and utilize N 2 . Among various N 2 electroreduction methods, combining N 2 reduction with batteries is simple and efficient. Here, a composite of ultrasmall Mo 2 C particles highly dispersed on N-doped carbon nanosheets is prepared, and it is applied as the air cathode for Li-N 2 batteries. ...

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