Structural Stabilization of P2-type Sodium Iron Manganese Oxides by Electrochemically Inactive Mg Substitution: Insights of Redox Behavior and Voltage Decay.

Layered P2-type Na0.8 Mn0.5 Fe0.5 O2 cathode material is a promising candidate for next-generation sodium-ion batteries due to the economical and environmentally benign characteristics of Mn and Fe. The poor cycling stability of the material, however, is still a problem that must be solved. To address the problem, electrochemically inactive Mg2+ was introduced into the structure by substituting some of the Fe ions. It was shown that Mg substitution led to a smoother voltage profile with improved cycling performance and rate capability. These observations were attributed to the suppressed structural changes during electrochemical processes. Detailed redox mechanisms, associated local structural changes, and phase transitions were investigated by X-ray absorption spectroscopy and X-ray diffraction. From the detailed analysis of electrochemical behaviors, it was also identified how the redox reactions and structural disordering occurred in the high- and low-voltage regions and how Mg substitution stabilized the structure.

Heterogeneity in liver histopathology is associated with GSK-3ß activity and mitochondrial dysfunction in end-stage diabetic rats on differential diets.

While liver histopathology is heterogeneous in diabetes, the underlying mechanisms remain unclear. We investigated whether glycemic variation resulting from differential diets can induce heterogeneity in diabetic liver and the underlying molecular mechanisms. We generated end-stage non-obese diabetic model rats by subtotal-pancreatectomy in male Sprague- Dawley rats and ad libitum diet for 7 weeks (n = 33). The rats were then divided into three groups, and fed a standard- or a low-protein diet (18 or 6 kcal%, respectively), for another 7 weeks: to maintain hyperglycemia, 11 rats were fed ad libitum (18AL group); to achieve euglycemia, 11 were calorierestricted (18R group), and 11 were both calorie- and proteinrestricted with the low-protein diet (6R group). Overnightfasted liver samples were collected after the differential diets together with sham-control (18S group), and histology and molecular changes were compared. Hyperglycemic-18AL showed glycogenic hepatopathy (GH) without steatosis, with the highest GSK-3ß inactivation because of Akt activation during hyperglycemia; mitochondrial function was not impaired, compared to the 18S group. Euglycemic-18R showed neither GH nor steatosis, with intermediate GSK-3ß activation and mitochondrial dysfunction. However, euglycemic-6R showed both GH and steatosis despite the highest GSK-3ß activity and no molecular evidence of increased lipogenesis or decreased ApoB expression, where mitochondrial dysfunction was highest among the groups. In conclusion, heterogeneous liver histopathology developed in end-stage non-obese diabetic rats as the glycemic levels varied with differential diets, in which protein content in the diets as well as glycemic levels differentially influenced GSK-3ß activity and mitochondrial function in insulin-deficient state. [BMB Reports 2020; 53(2): 100-105].

Factors associated with ischemic stroke on therapeutic anticoagulation in patients with nonvalvular atrial fibrillation.

PURPOSE: In this study, we investigated the stroke mechanism and the factors associated with ischemic stroke in patients with nonvalvular atrial fibrillation (NVAF) who were on optimal oral anticoagulation with warfarin. MATERIALS AND METHODS: This was a multicenter case-control study. The cases were consecutive patients with NVAF who developed cerebral infarction or transient ischemic attack (TIA) while on warfarin therapy with an international normalized ratio (INR) ≥2 between January 2007 and December 2011. The controls were patients with NVAF without ischemic stroke who were on warfarin therapy for more than 1 year with a mean INR ≥2 during the same time period. We also determined etiologic mechanisms of stroke in cases. RESULTS: Among 3569 consecutive patients with cerebral infarction or TIA who had NVAF, 55 (1.5%) patients had INR ≥2 at admission. The most common stroke mechanism was cardioembolism (76.0%). Multivariate analysis demonstrated that smoking and history of previous ischemic stroke were independently associated with cases. High CHADS2 score (≥3) or CHA2DS2-VASc score (≥5), in particular, with previous ischemic stroke along with ≥1 point of other components of CHADS2 score or ≥3 points of other components of CHA2DS2-VASc score was a significant predictor for development of ischemic stroke. CONCLUSION: NVAF patients with high CHADS2/CHA2DS2-VASc scores and a previous ischemic stroke or smoking history are at high risk of stroke despite optimal warfarin treatment. Some other measures to reduce the risk of stroke would be necessary in those specific groups of patients.

Diet control to achieve euglycemia induces significant loss of heart and liver weight via increased autophagy compared with ad libitum diet in diabetic rats.

Intensive glucose control increases the all-cause mortality in type 2 diabetes mellitus (T2DM); however, the underlying mechanisms remain unclear. We hypothesized that strict diet control to achieve euglycemia in diabetes damages major organs, increasing the mortality risk. To evaluate effects on major organs when euglycemia is obtained by diet control, we generated a model of end-stage T2DM in 13-week-old Sprague-Dawley rats by subtotal pancreatectomy, followed by ad libitum feeding for 5 weeks. We divided these rats into two groups and for the subsequent 6 weeks provided ad libitum feeding to half (AL, n=12) and a calorie-controlled diet to the other half (R, n=12). To avoid hypoglycemia, the degree of calorie restriction in the R group was isocaloric (g per kg body weight per day) compared with a sham-operated control group (C, n=12). During the 6-week diet control period, AL rats ate three times more than rats in the C or R groups, developing hyperglycemia with renal hyperplasia. R group achieved euglycemia but lost overall body weight significantly compared with the C or AL group (49 or 22%, respectively), heart weight (39 or 23%, respectively) and liver weight (50 or 46%, respectively). Autophagy levels in the heart and liver were the highest in the R group (P<0.01), which also had the lowest pAkt/Akt levels among the groups (P<0.05 in the heart; P<0.01 in the liver). In conclusion, glycemic control achieved by diet control can prevent hyperglycemia-induced renal hyperplasia in diabetes but may be deleterious even at isocaloric rate when insulin is deficient because of significant loss of heart and liver mass via increased autophagy.

Central pontine myelinolysis presented after prophylactic cranial irradiation in small cell lung cancer.

Prophylactic cranial irradiation (PCI) should now be considered as a part of the standard treatment of patients with small cell lung cancer (SCLC) in complete remission. The PCI has been offered in SCLC to reduce the incidence of brain metastasis and increase survival. The complications of PCI were reported brain necrosis, seizure or dementia. The complications were more frequent when chemotherapy was given at the time of cranial irradiation, or large radiation fraction size was employed. It is established that the pathophysiological reaction to irradiation in the normal brain tissue is necrosis, demyelinization, and diffuse changes due to wall thickening of the vascular structures. However, central pontine myelinolysis (CPM) of low dose irradiation like PCI is very rare. We report a patient with the classical syndrome of CPM following PCI for SCLC. The diagnosis was supported by typical features on magnetic resonance imaging.

Spontaneous left external iliac vein rupture.

We report a 72-year-old female patient with spontaneous rupture of the left external iliac vein. She visited our hospital for abdominal and back pain. She had the abnormal finding of hemoperitoneum. We performed an emergency operation with diagnosis of left ovarian cyst rupture though she suffered from spontaneous rupture of the left external iliac vein. This case provides insight to the experience of spontaneous rupture of the left external iliac vein.