ABSTRACT
Objective: To evaluate the efficacy, safety, and clinical implication of betrixaban for prophylaxis of venous thromboembolism (VTE) in patients with acute medical illness. Data Sources: A search for clinical trials was performed from January 2006 to January 2017 in English language using Clinicaltrials.gov and PubMed/MEDLINE. The following search terms were used: betrixaban, pharmacokinetics, pharmacology, and drug safety. Study Selection: The following limits were used to access the clinical trials: controlled clinical trial, randomized clinical trial, clinical trial, clinical trial phase II, and clinical trial phase III. The search was narrowed to include only humans. Data Extraction: The search criteria resulted in 6 clinical trials assessing the safety and efficacy of betrixaban. Additionally, references from publications assessing the safety and efficacy of betrixaban in atrial fibrillation, treatment and prevention of VTE, and extended duration VTE prophylaxis were assessed. Data Synthesis: Prior to 2017, no anticoagulant therapy had been approved for extended VTE prophylaxis in acutely ill medical patients. Betrixaban is the first direct oral anticoagulant approved for VTE prophylaxis in adult, acutely ill patients at risk for thromboembolisms. Based on the APEX trial, betrixaban 80 mg administered daily for 35 to 42 days was compared to enoxaparin administered daily for 6 to 14 days. In 7441 patients, fewer VTEs were seen in the betrixaban compared to enoxaparin with no significant difference in adverse reactions. Conclusion: Based on clinical trials, betrixaban appears to be safe and effective in preventing VTE in acutely ill patients who are at risk of developing VTE.
ABSTRACT
Understanding and controlling the sulfur reduction species (Li2Sx, 1 ≤ x ≤ 8) under realistic battery conditions are essential for the development of advanced practical Li-S cells that can reach their full theoretical capacity. However, it has been a great challenge to probe the sulfur reduction intermediates and products because of the lack of methods. This work employed various ex situ and in situ methods to study the mechanism of the Li-S redox reactions and the properties of Li2Sx and Li2S. Synchrotron high-energy X-ray diffraction analysis used to characterize dry powder deposits from lithium polysulfide solution suggests that the new crystallite phase may be lithium polysulfides. The formation of Li2S crystallites with a polyhedral structure was observed in cells with both the conventional (LiTFSI) electrolyte and polysulfide-based electrolyte. In addition, an in situ transmission electron microscopy experiment observed that the lithium diffusion to sulfur during discharge preferentially occurred at the sulfur surface and formed a solid Li2S crust. This may be the reason for the capacity fade in Li-S cells (as also suggested by EIS experiment in Supporting Information ). The results can be a guide for future studies and control of the sulfur species and meanwhile a baseline for approaching the theoretical capacity of the Li-S battery.
