Successful Treatment of Diffuse Large B-cell Lymphoma Involving Multiple Renal and Bone Infiltrations Presenting with Giant Cell Arteritis-like Manifestations: A Case Report.

We herein report a case of diffuse large B-cell lymphoma (DLBCL) involving multiple renal and bone infiltrations presenting with giant cell arteritis-like (GCA)-like manifestations. One month prior, the present patient had left-sided temporal headache, jaw claudication, and renal failure. The patient was diagnosed with DLBCL based on a renal biopsy. After rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) plus intrathecal methotrexate/cytarabine/prednisone and rituximab, high-dose methotrexate, and cytarabine (R-MA) chemotherapy, the patient's clinical manifestations improved, and complete remission was achieved. DLBCL rarely but occasionally presents with GCA-like manifestations or multiple renal and bone infiltrations, highlighting the need for prompt and aggressive combination chemotherapy.

Positive Feedback Mechanism to Increase the Charging Voltage of Li-O2 Batteries.

The large overpotential of nonaqueous Li-O2 batteries when charging causes low round-trip efficiency and decomposition of the electrode materials and electrolyte. The origins of this overpotential have been enthusiastically explored to date; however, a full understanding has not yet been reached because of the complexity of multistep reaction mechanisms. Here, we applied structural and electrochemical analysis techniques to investigate the reaction step that results in the increase of the overpotential when charging. Rietveld refinement of ex situ powder X-ray diffraction showed that a Li-deficient phase of Li2O2, Li2-xO2, formed when discharging and was present over the course of charging. The galvanostatic intermittent titration technique revealed that the rate-determining process in the first step of charging was a solid-solution type of delithiation. The chemical diffusion coefficient of Li+ ions in Li2-xO2, DLi, decreases as the cell voltage increases, which in turn leads to a decrease in the oxidation rate of Li2-xO2. Under galvanostatic conditions, the deceleration of oxidation induces further increase of the cell voltage; therefore, an intrinsic mechanism of positive feedback to increase the cell voltage occurs in the first step. The results demonstrate that the continuity of the first step can be extended by the suppression of changes in any of the elements of the positive feedback loop, i.e., the oxidation rate, cell voltage, or DLi.

Isotopic Depth Profiling of Discharge Products Identifies Reactive Interfaces in an Aprotic Li-O2 Battery with a Redox Mediator.

Prior to the practical application of rechargeable aprotic Li-O2 batteries, the high charging overpotentials of these devices (which inevitably cause irreversible parasitic reactions) must be addressed. The use of redox mediators (RMs) that oxidatively decompose the discharge product, Li2O2, is one promising solution to this problem. However, the mitigating effect of RMs is currently insufficient, and so it would be beneficial to clarify the Li2O2 reductive growth and oxidative decomposition mechanisms. In the present work, Nanoscale secondary ion mass spectrometry (Nano-SIMS) isotopic three-dimensional imaging and differential electrochemical mass spectrometry (DEMS) analyses of individual Li2O2 particles established that both growth and decomposition proceeded at the Li2O2/electrolyte interface in a system containing the Br-/Br3- redox couple as the RM. The results of this study also indicated that the degree of oxidative decomposition of Li2O2 was highly dependent on the cell voltage. These data show that increasing the RM reaction rate at the Li2O2/electrolyte interface is critical to improve the cycle life of Li-O2 batteries.

Dynamic Changes in Charge Transfer Resistances during Cycling of Aprotic Li-O2 Batteries.

Various electrolyte components have been investigated with the aim of improving the cycle life of lithium-oxygen (Li-O2) batteries. A tetraglyme-based electrolyte containing dual anions of Br- and NO3- is a promising electrolyte system in which the cell voltage during charging is reduced because of the redox-mediator function of the Br-/Br3- and NO2-/NO2 couples, while the Li-metal anode is protected by Li2O formed via the reaction between Li metal and NO3-. To maximize the potential of this system, the fundamental factors that limit the cycle life should be clarified. In the present work, we used nondestructive electrochemical impedance spectroscopy to analyze the temporal change of the charge transfer resistances during cycles of Li-O2 batteries with dual anions. The charge transfer resistance at the cathode was revealed to exhibit good correlation with the reduction of the discharge voltage. These results, combined with the results of electrode surface inspections, revealed that irreversible accumulation of insulating deposits such as Li2O2 and Li2CO3 on the cathode surface was a major cause of the short cycle life. Furthermore, the analyses of the time course of the solution resistance suggested that diminished reactivity between the redox mediators and Li2O2 was a critical factor that led to the irreversible accumulation of the less-reactive Li2O2 on the cathode and eventually to a shortened cycle life. These findings indicated that increasing the reactivity between Br3- and Li2O2 is essentially important for improving the cycle stability of Li-O2 batteries and the reactivity can be nondestructively assessed by tracking the dynamic changes in the solution resistance.