Publications by authors named "Alexander Olson"

Particle filtration can effectively reduce indoor concentrations of particulate matter (PM) but may incur high energy use. This study evaluates fixed and adaptive concentration thresholds to automate the operation of filtration systems. Simulated environments were derived from week-long continuous PM measurements from Dylos DC1700 (N = 104) and Alphasense OPC-N2 (N = 100) particle counters deployed in apartments in Toronto.

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The building sector is a voracious consumer of primary materials. However, the study of building material use and associated impacts is challenged by the paucity of publicly available data in the field and the heterogeneity of data organization and classification between published studies. This paper makes two main contributions.

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Autonomic dysreflexia occurs after a spinal cord injury usually at the level of T6 or above, and its hallmark feature is exaggerated autonomic response to noxious stimuli resulting in uncontrolled hypertensive episodes with reflexive bradycardia that can be fatal if not controlled. We present a case highlighting regional anesthetic techniques, including peripheral nerve blocks, to ameliorate the symptoms of autonomic dysreflexia triggered by hip fractures in a 57-year-old woman with an old C5-C6 spinal cord injury before definitive hip surgery. The regional techniques described provide anesthesiologists with a simple strategy to potentially mitigate a life-threatening situation.

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Purpose Of Review: While ketamine's analgesia has mostly been attributed to antagonism of N-methyl-D-aspartate receptors, evidence suggests multiple other pathways are involved in its antidepressant and possibly analgesic activity. These mechanisms and ketamine's role in the nociplastic pain paradigm are discussed. Animal studies demonstrating ketamine's neurotoxicity have unclear human translatability and findings from key rodent and human studies are presented.

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Background: Plasma thrombin generation has been used to characterize trauma-induced coagulopathy, but description of whole blood thrombin generation is lacking. This study aimed to evaluate plasma and whole blood thrombin generation in healthy volunteers and trauma patients. We hypothesized that (1) plasma and whole blood thrombin generation are distinct, (2) whole blood thrombin generation is more pronounced in trauma patients than in healthy volunteers, and (3) thrombin generation correlates with clinical coagulation assays.

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Importance: Novel sensitive methods for detection and monitoring of residual disease can improve postoperative risk stratification with implications for patient selection for adjuvant chemotherapy (ACT), ACT duration, intensity of radiologic surveillance, and, ultimately, outcome for patients with colorectal cancer (CRC).

Objective: To investigate the association of circulating tumor DNA (ctDNA) with recurrence using longitudinal data from ultradeep sequencing of plasma cell-free DNA in patients with CRC before and after surgery, during and after ACT, and during surveillance.

Design, Setting, And Participants: In this prospective, multicenter cohort study, ctDNA was quantified in the preoperative and postoperative settings of stages I to III CRC by personalized multiplex, polymerase chain reaction-based, next-generation sequencing.

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Purpose: Novel sensitive methods for early detection of relapse and for monitoring therapeutic efficacy may have a huge impact on risk stratification, treatment, and ultimately outcome for patients with bladder cancer. We addressed the prognostic and predictive impact of ultra-deep sequencing of cell-free DNA in patients before and after cystectomy and during chemotherapy.

Patients And Methods: We included 68 patients with localized advanced bladder cancer.

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Purpose: Up to 30% of patients with breast cancer relapse after primary treatment. There are no sensitive and reliable tests to monitor these patients and detect distant metastases before overt recurrence. Here, we demonstrate the use of personalized circulating tumor DNA (ctDNA) profiling for detection of recurrence in breast cancer.

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Synthetic cannabinoids are the largest and most structurally diverse class of new psychoactive substances, with manufacturers often using isomerism to evade detection and circumvent legal restriction. The regioisomeric methoxy- and fluorine-substituted analogs of SDB-006 (N-benzyl-1-pentyl-1H-indole-3-carboxamide) were synthesized and could not be differentiated by gas chromatography-mass spectrometry (GC-MS), but were distinguishable by liquid chromatography-quadrupole time-of-flight-MS (LC-QTOF-MS). In a fluorescence-based plate reader membrane potential assay, SDB-006 acted as a potent agonist at human cannabinoid receptors (CB EC = 19 nM).

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In 2013 and 2014, more than 700 deaths were attributed to fentanyl and fentanyl analogues in the United States. Of recent concern is the cluster of unintentional fentanyl overdoses because of tablets thought to be "Norco" purchased on the street in Northern California. U-47700 (trans-3,4-dichloro-N-[2-(dimethyl-amino)cyclohexyl]-N-methylbenz-amide) is a nonfentanyl-based synthetic opioid with 7.

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Journal-based science communication is not accessible or comprehensible to a general public curious about science and eager for the next wave of scientific innovation. We propose an alternative medium for scientists to communicate their work to the general public in an engaging and digestible way through the use of whiteboard videos. We describe the process of producing science whiteboard videos and the benefits and challenges therein.

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Coadministration of nevirapine-based antiretroviral therapy (ART) and artemether-lumefantrine is reported to result in variable changes in lumefantrine exposure. We conducted an intensive pharmacokinetic study with 11 HIV-infected adults who were receiving artemether-lumefantrine plus nevirapine-based ART, and we compared the results with those for 16 HIV-negative adult historical controls. Exposure to artemether and lumefantrine was significantly lower and dihydroartemisinin exposure was unchanged in subjects receiving nevirapine-based ART, compared with controls.

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Background: Numerous methods have been reported for the determination of artemether (ARM) and its metabolite dihydroartemisinin (DHA) in plasma. However, stability issues in patient plasma have not received enough attention.

Results: An LC-MS/MS method for simultaneous determination of ARM and DHA in human plasma (K3EDTA) turned out to be problematic: ARM and DHA were degraded partially or completely in some patient plasma samples as indicated by the stable isotope-labeled internal standards.

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