Improvement of stability and capacity of Co-free, Li-rich layered oxide Li1.2Ni0.2Mn0.6O2 cathode material through defect control.

Layered oxides based on manganese (Mn), rich in lithium (Li), and free of cobalt (Co) are the most promising cathode candidates used for lithium-ion batteries due to their high capacity, high voltage and low cost. These types of material can be written as xLi2MnO3·(1 - x) LiTMO2 (TM = Ni,Mn,etc.). Though, Li2MnO3 is known to have poor cycling stability and low capacity, which hinder its industrial application commercially. In this work, Li1.2Ni0.2Mn0.6O2 materials with different amounts of structural defects was successfully synthesized using powder metallurgy followed by different cooling processes in order to improve its electrochemical properties. Microstructural analyses and electrochemical measurements were carried out on the study samples synthesized by a combination of X-ray diffraction, transmission electron microscopy, and cyclic voltammetry. It is found that the disorder of the transition metal layer in Li2MnO3 promotes its electrochemical activity, whereas the Li/Ni antisites of the Li layer maintain the stability of its local structure. The material with optimal amount of structural defects had an initial capacity of 188.2 mAh g-1, while maintaining an excellent specific capacity of 144.2 mAh g-1 after 500 cycles at 1C. In comparison, Li1.2Ni0.2Mn0.6O2 without structural defect only gives a capacity of 40.8 mAh g-1 after cycling. This microstructural control strategy provides a simple and effective route to develop high-performance Co-free, Li-rich Mn-based cathode materials and scale-up manufacturing.

Fatty liver disease is associated with the severity of acute pancreatitis:A systematic review and meta-analysis.

BACKGROUND: Fatty liver (FL) has been positively associated with the risk of acute pancreatitis (AP), but whether FL is associated with the severity of AP remains unknown. To this, a meta-analysis was conducted to assess the effect of FL on severity and outcomes of AP. METHOD: We searched PubMed, EMBASE and the Cochrane library to identify all eligible studies (up to June 2017). We pooled the odds ratios (ORs) or weighted mean differences (WMD) from individual studies using a random-effects model to investigate associations between FL and the prognosis of AP. RESULT: Four studies were included in the meta-analysis, including a total of 805 patients with fatty liver-related acute pancreatitis (FLAP) and 1026 patients with non fatty liver-related acute pancreatitis (NFLAP). The incidences of moderately severe AP (MSAP) (OR = 2.72, 95%CI: 1.82-4.05, P < 0.001) and severe AP (SAP) (OR = 3.57, 95%CI: 2.06-6.18, P < 0.001) were statistically significantly higher in FLAP group than those in NFLAP group. Taking obesity into consideration, a higher rate of MSAP and SAP were also found in patients with FL, no matter whether they were obese or not. Furthermore, mortality (OR = 4.16, 95%CI: 2.57-6.73, P < 0.001), systemic inflammatory response syndrome (SIRS) (OR = 2.82, 95%CI: 2.3-3.47, P < 0.001) and local complications were also statistically significantly higher in the FLAP group than in NFLAP group. CONCLUSION: Fatty liver is associated with the severity of acute pancreatitis.

[Protein loss in critically ill patients during continuous veno-venous hemofiltration].

OBJECTIVE: To evaluate protein loss in critically ill patients with acute renal failure during continuous veno-venous hemofiltration (CVVH) and analysis the major factor impacting protein clearance. METHODS: A analysis was carried out in eighteen (twelve male and six female) sepsis or severe acute pancreatitis patients with acute renal failure from September 2008 to September 2009. The average age was 45 years (39 - 62 years). CVVH was conducted for 24 h in all patients. Effluent volume, blood speed, ultrafiltration rate and transmembrane pressure (TMP) were 4000 ml/h, (277 ± 89) ml/h, (179 ± 4) ml/min and (173 ± 48) mm Hg (1 mm Hg = 0.133 kPa) respectively. Blood samples were collected before and after filtration in order to detect protein concentration. Ultrafiltrate was obtained hourly to measure protein concentration and calculate protein loss during session. RESULTS: Mean protein concentration was (231 ± 67) mg/L and protein loss was (22 ± 6) g/d in ultrafiltrate samples. The difference in serum protein level during hemofiltration was not significant [(56 ± 6) g/L vs. (55 ± 10) g/L, P > 0.05], while there was a weak, but statistically significant correlation between the ultrafiltrate protein concentration and the corresponding value for serum protein (r = 0.481, P < 0.05). However, there was a strong and statistically significant correlation between the ultrafiltrate protein concentration and the TMP (r = 0.564, P < 0.01). Stepwise multiple regression analysis showed that TMP and serum protein concentration played a pivotal role in ultrafiltrate protein loss. CONCLUSIONS: In addition to renal replacement therapy, serum protein would be cleared through hemofilter during CVVH. TMP and serum protein concentration are the main factors that affect protein loss in ultrafiltrate. As a result, it is necessary to take account of the protein loss in ultrafiltrate when setting nutritional schedule.