Ataxia telangiectasia mutated (ATM) protein has been implicated in multiple pathways such as DNA repair, cell cycle checkpoint, cell growth, development, and stem cell renewal. In this study, we ...demonstrate evidence that ATM is involved in granulocyte macrophage colony-stimulating factor (GM-CSF)-induced dendritic cell (DC) development from bone marrow (BM) cells. Inactivation of ATM protein results in decreased BM proliferation, leading to reduced DC development and their activity for T cell activation. Expression of Jak2, STAT5, and mTOR is suppressed in both wild-type and ATM-null BM prior to GM-CSF stimulation. Activation of those proteins is delayed and prolonged hypophosphorylation of 4EBP1 is observed in ATM-null BM when treated with GM-CSF, although Erk and p38 are similarly expressed and activated in both wild-type and ATM-null BM cell types. Akt is also suppressed in wild-type BM, and transduction of constitutively active Akt or STAT5 in ATM-null BM restores DC development. Together, these results illustrate that ATM deficiency causes impaired initiation of protein translation in BM, leading to immature development of DC.
Nickel-metal hydride battery (NiMH) performance has been compiled and analyzed against modifier compositions of metal hydride alloys used in the negative electrode. Thirty-three alloys with the ...general chemical formula Ti
12Zr
21.5V
10Ni
56.5-
a-
b-
c-
d-
e
Cr
a
Mn
b
Sn
c
Co
d
Al
e
(1.0
≤
a
≤
14.5, 1.1
≤
b
≤
15.6, 0.3
≤
c
≤
0.8, 0.0
≤
d
≤
8.0, and 0.0
≤
e
≤
3.1) were made into ingots, powders, electrodes, and batteries to study the influence of Ni, Cr, Mn, Sn, Co, and Al on NiMH battery performance. C14-predominancy and multi-component nature were confirmed by X-ray diffraction and scanning electron microscope, respectively. Gas phase storage, half-cell, and full-cell characteristics of these alloys were measured, and the influence from each modifier element was analyzed. Correlations between measured properties were also studied and reported.
The role of Mn in C14 Laves phase alloys for battery applications was studied by adjusting the Mn content in exchange with Ni and Cr in three series of C14 AB2 Laves phase alloys. Additional ...B-modifiers, such as Sn, Co, and Al as a group, were also compared to Mn using AB2 MH alloys in a nickel metal hydride (NiMH) battery. In all cases, higher Mn content degraded the cycle life performance while marginally increasing the discharge capacity. Without the presence of other modifiers, such as Sn, Co, and Al, Mn proved to be detrimental to both charge retention and activation of Ti-based C14 Laves phase MH alloys. However, in combination with Sn, Co, and Al; Mn contributed positively to charge retention while activation remained at a manageable level. It has also been shown a lower Mn and higher Ni content improved the specific power and low temperature performance, whereas increasing Cr content at the expense of Mn improved cycle life and charge retention in a NiMH battery.
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