Association of antithrombotic therapy with postoperative rebleeding in patients with cerebral amyloid angiopathy

Background Cerebral amyloid angiopathy is a common cause of subcortical hemorrhage in older adults.Although open hematoma removal may be performed for severe subcortical hemorrhage,its safety in patients with cerebral amyloid angiopathy has not been established,and postoperative rebleeding may occur.Therefore,this study aimed to investigate factors associated with postoperative rebleeding.Methods Out of 145 consecutive patients who had undergone craniotomy for surgical removal of subcortical intracerebral hemorrhage between April 2010 and August 2019 at a single institution in Japan,we examined 109 patients with subcortical hemorrhage who met the inclusion criteria.After excluding 30 patients whose tissue samples were unsuitable for the study,the final study cohort comprised 79 patients.Results Of the 79 patients,50(63%)were diagnosed with cerebral amyloid angiopathy(cerebral amyloid angiopathy group)and 29(37%)were not diagnosed with noncerebral amyloid angiopathy(noncerebral amyloid angiopathy group).Postoperative rebleeding occurred in 12 patients(24%)in the cerebral amyloid angiopathy group and in 2 patients(7%)in the noncerebral amyloid angiopathy group.Preoperative prothrombin time-international normalized ratio and intraoperative bleeding volume were significantly associated with postoperative rebleeding in the cerebral amyloid angiopathy group(odds ratio=42.4,95%confidence interval=1.14-1578;p=0.042 and odds ratio=1.005,95%confidence interval=1.001-1.008;p=0.007,respectively).Conclusions Patients with cerebral amyloid angiopathy-related cerebral hemorrhage who are receiving antithrombotic therapy,particularly warfarin therapy,are at a high risk of postoperative rebleeding.Trial registration Registry and Registration Number of the study:19-220,2019/12/23,retrospectively registered.

Simple Fabrication and Characterization of Discontinuous Carbon Fiber Reinforced Aluminum Matrix Composite for Lightweight Heat Sink Applications

The constant increase in power and heat flux densities encountered in electronic devices fuels a rising demand for lightweight heat sink materials with suitable thermal properties.In this study,discontinuous pitch-based carbon fiber reinforced aluminum matrix（Al-CF） composites with aluminum–silicon alloy（Al–Si） were fabricated through hot pressing.The small amount of Al–Si contributed to enhance the sintering process in order to achieve fully dense Al–CF composites.A thermal conductivity and CTE of 258 W/（m K） and 7.0 9 10-6/K in the in-plane direction of the carbon fibers were obtained for a（Al95 vol%＋ Al–Si5 vol%）-CF50 vol%composite.Carbon fiber provides the reducing of CTE while the conservation of thermal conductivity and weight of Al.The achieved CTEs satisfy the standard requirements for a heat sink material,which furthermore possess a specific thermal conductivity of 109 W cm3/（m K g）.This simple process allows the low-cost fabrication of Al–CF composite,which is applicable for a lightweight heat sink material.