Nickel-Catalyzed Asymmetric Reductive Cross-Coupling of a-Chloroesters with (Hetero)Aryl Iodides

An asymmetric reductive cross-coupling of alpha-chloroesters and (hetero)aryl iodides is reported. This nickel-catalyzed reaction proceeds with a chiral BiOX ligand under mild conditions, affording alpha-arylesters in good yields and enantioselectivities. The reaction is tolerant of a variety of functional groups, and the resulting products can be converted to pharmaceutically-relevant chiral building blocks. A multivariate linear regression model was developed to quantitatively relate the influence of the alpha-chloroester substrate and ligand on enantioselectivity

Angioedema Secondary to Tenecteplase Use in a Patient with Acute Ischemic Stroke: A Case Report

Introduction: Angioedema, a swelling of the subcutaneous or submucosal layers of the skin or gastrointestinal tract, is a potential complication to thrombolytic therapy in the treatment of acute ischemic strokes. In these cases, angioedema develops due to increased levels of bradykinin as a result of the activation of the fibrinolytic pathway and contact activation system. Angioedema can involve the tongue, larynx, and vocal cords, leading to occlusion of the airway and death due to asphyxiation. It is vital for the emergency physician to know that this complication can occur to ensure appropriate monitoring for development of angioedema. Case Report: We report the case of a 65-year-old Black man who presented with signs of an acute ischemic stroke and was treated with tenecteplase. The patient’s stroke symptoms mostly resolved within 90 minutes; however, he developed swelling of his right upper lip consistent with angioedema. The patient was treated with steroids and antihistamines. He was closely monitored and did not require airway intervention. The angioedema was almost fully resolved by the following day. Conclusion: Angioedema is a known complication of thrombolytic therapy for acute ischemic stroke. Risk factors for alteplase-associated angioedema include use of angiotensin-converting enzyme inhibitors, female gender, diabetes, and infarcts of the insula and frontal cortex. As hospital systems switch from alteplase to tenecteplase for the treatment of acute ischemic strokes for reasons of cost and ease of administration, it is important to recognize that angioedema is also a potential complication of tenecteplase

Nickel-Catalyzed Asymmetric Reductive Cross-Coupling of a-Chloroesters with (Hetero)Aryl Iodides

An asymmetric reductive cross-coupling of alpha-chloroesters and (hetero)aryl iodides is reported. This nickel-catalyzed reaction proceeds with a chiral BiOX ligand under mild conditions, affording alpha-arylesters in good yields and enantioselectivities. The reaction is tolerant of a variety of functional groups, and the resulting products can be converted to pharmaceutically-relevant chiral building blocks. A multivariate linear regression model was developed to quantitatively relate the influence of the alpha-chloroester substrate and ligand on enantioselectivit

Challenges Related to the Implementation of an EMS-Administered, Large Vessel Occlusion Stroke Score

Introduction: There is considerable interest in triaging victims of large vessel occlusion (LVO) strokes to comprehensive stroke centers. Timely access to interventional therapy has been linked to improved stroke outcomes. Accurate triage depends upon the use of a validated screening tool in addition to several emergency medical system (EMS)-specific factors. This study examines the integration of a modified Rapid Arterial oCcclusion Evaluation (mRACE) score into an existing stroke treatment protocol.Methods: We performed a retrospective review of EMS and hospital charts of patients transported to a single comprehensive stroke center. Adult patients with an EMS provider impression of “stroke/TIA,” “CVA,” or “neurological problem” were included for analysis. EMS protocols mandated the use of the Cincinnati Prehospital Stroke Score (CPSS). The novel protocol authorized the use of the mRACE score to identify candidates for triage directly to the comprehensive stroke center. We calculated specificity and sensitivity for various stroke screens (CPSS and a mRACE exam) for the detection of LVO stroke. The score’s metrics were evaluated as a surrogate marker for a successful EMS triage protocol.Results: We included 312 prehospital charts in the final analysis. The CPSS score exhibited reliable sensitivity at 85%. Specificity of CPSS for an LVO was calculated at 73%. For an mRACE score of five or greater, the sensitivity was 25%. Specificity for mRACE was calculated at 75%. The positive predictive value of the mRACE score for an LVO was estimated at 12.50%.Conclusion: In this retrospective study of patients triaged to a single comprehensive stroke center, the addition of an LVO-specific screening tool failed to improve accuracy. Reliable triage of LVO strokes in the prehospital setting is a challenging task. In addition to statistical performance of a particular stroke score, a successful EMS protocol should consider system-based factors such as provider education and training. Study limitations can inform future iterations of LVO triage protocols

Charon: Specialized near-memory processing architecture for clearing dead objects in memory

© 2019 Association for Computing Machinery.programming, saving a programmer from many nasty memoryrelated bugs. However, these productivity benefits come with a cost in terms of application throughput, worst-case latency, and energy consumption. Since the first introduction of GC by the Lisp programming language in the 1950s, a myriad of hardware and software techniques have been proposed to reduce this cost. While the idea of accelerating GC in hardware is appealing, its impact has been very limited due to narrow coverage, lack of flexibility, intrusive system changes, and significant hardware cost. Even with specialized hardware GC performance is eventually limited by memory bandwidth bottleneck. Fortunately, emerging 3D stacked DRAM technologies shed new light on this decades-old problem by enabling efficient near-memory processing with ample memory bandwidth. Thus, we propose Charon1, the first 3D stacked memory-based GC accelerator. Through a detailed performance analysis of HotSpot JVM, we derive a set of key algorithmic primitives based on their GC time coverage and implementation complexity in hardware. Then we devise a specialized processing unit to substantially improve their memory-level parallelism and throughput with a low hardware cost. Our evaluation of Charon with the full-production HotSpot JVM running two big data analytics frameworks, Spark and GraphChi, demonstrates a 3.29 geomean speedup and 60.7% energy savings for GC over the baseline 8-core out-of-order processor.N

Design and Analysis of an APU for Exascale Computing

Abstract-The challenges to push computing to exaflop levels are difficult given desired targets for memory capacity, memory bandwidth, power efficiency, reliability, and cost. This paper presents a vision for an architecture that can be used to construct exascale systems. We describe a conceptual Exascale Node Architecture (ENA), which is the computational building block for an exascale supercomputer. The ENA consists of an Exascale Heterogeneous Processor (EHP) coupled with an advanced memory system. The EHP provides a high-performance accelerated processing unit (CPU+GPU), in-package high-bandwidth 3D memory, and aggressive use of die-stacking and chiplet technologies to meet the requirements for exascale computing in a balanced manner. We present initial experimental analysis to demonstrate the promise of our approach, and we discuss remaining open research challenges for the community

ssg-research/BliMe-gem5: 2023-11-17

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