Dynamic Assembly of Strong and Conductive Carbon Nanotube/Nanocellulose Composite Filaments and Their Application in Resistive Liquid Sensing.

The continuous flow assembly of colloidal nanoparticles from aqueous suspensions into macroscopic materials in a field-assisted double flow focusing system offers an attractive way to bridge the outstanding nanoscale characteristics of renewable cellulose nanofibrils (CNFs) at scales most common to human technologies. By incorporating single-walled carbon nanotubes (SWNTs) during the fabrication process, high-performance functional filament nanocomposites were produced. CNFs and SWNTs were first dispersed in water without any external surfactants or binding agents, and the resulting nanocolloids were aligned by means of an alternating electric field combined with extensional sheath flows. The nanoscale orientational anisotropy was then locked by a liquid-gel transition during the materials assembly into macroscopic filaments, which greatly improved their mechanical, electrical, and liquid sensing properties. Significantly, these findings pave the way toward the environmentally friendly and scalable manufacturing of a variety of multifunctional fibers for diverse applications.

Range-wide sources of variation in reproductive rates of northern spotted owls.

We conducted a range-wide investigation of the dynamics of site-level reproductive rate of northern spotted owls using survey data from 11 study areas across the subspecies geographic range collected during 1993-2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed further insights into northern spotted owl population ecology and dynamics. Both nondetection and state misclassification were important, especially because factors affecting these sources of error also affected focal ecological parameters. Annual probabilities of site occupancy were greatest at sites with successful reproduction in the previous year and lowest for sites not occupied by a pair in the previous year. Site-specific occupancy transition probabilities declined over time and were negatively affected by barred owl presence. Overall, the site-specific probability of successful reproduction showed substantial year-to-year fluctuations and was similar for occupied sites that did or did not experience successful reproduction the previous year. Site-specific probabilities for successful reproduction were very small for sites that were unoccupied the previous year. Barred owl presence negatively affected the probability of successful reproduction by northern spotted owls in Washington and California, as predicted, but the effect in Oregon was mixed. The proportions of sites occupied by northern spotted owl pairs showed steep, near-monotonic declines over the study period, with all study areas showing the lowest observed levels of occupancy to date. If trends continue it is likely that northern spotted owls will become extirpated throughout large portions of their range in the coming decades.

Association of Linezolid With Risk of Serotonin Syndrome in Patients Receiving Antidepressants.

Importance: Linezolid has the potential to interact with some antidepressants, leading to serotonin syndrome. However, few empirical data support warnings for patients taking antidepressants to avoid linezolid. Objectives: To examine the incidence of serotonin syndrome in patients receiving oral linezolid and how concomitant antidepressant treatment changes this risk. Design, Setting, and Participants: This population-based, retrospective cohort study used linked administrative databases at ICES to collect data from outpatients 66 years or older in Ontario, Canada, who were prescribed oral linezolid for any duration from October 1, 2014, to January 1, 2021, with follow-up to 30 days (January 31, 2021). Exposures: The use of antidepressants while receiving linezolid therapy vs no antidepressant use while receiving linezolid therapy. Main Outcomes and Measures: The primary outcome was clinically significant serotonin syndrome based on a physician diagnosis, Sternbach criteria, or the Hunter Serotonin Toxicity Criteria within 30 days of starting oral linezolid treatment. Secondary outcomes were altered mental status, hospitalization, or death within 30 days of starting linezolid treatment. Results: The study included 1134 patients (age ranges, 66-69 years for 225 patients [19.8%], 70-79 years for 473 patients [41.7%], and ≥80 years for 436 patients [38.4%]; 595 [52.5%] male) who were prescribed linezolid. Of 1134 patients, 215 (19.0%) were also taking antidepressants. Serotonin syndrome occurred in fewer than 6 patients (<0.5%). The number of serotonin syndrome cases were fewer in the antidepressant group. In a propensity score-matched cohort, the adjusted risk difference for serotonin syndrome between the antidepressant group and the no antidepressant group was -1.2% (95% CI, -2.9% to 0.5%). There were similar rates of altered mental status, hospitalization, and death between the propensity score-matched groups. Conclusions and Relevance: In this cohort study of older patients who were prescribed linezolid, serotonin syndrome occurred rarely. Concurrent antidepressants did not significantly increase the risk of serotonin syndrome. These findings suggested that linezolid is likely safe for patients receiving antidepressants. Nevertheless, prescribers should remain vigilant for this potential drug interaction.

Safety Profile of Linezolid in Older Adults With Renal Impairment: A Population-Based Retrospective Cohort Study.

Background: The objective of this study was to characterize the safety profile of linezolid in patients with renal impairment compared with patients without renal impairment. Methods: A population-based retrospective cohort study using linked administrative databases included patients aged 66 years or older in Ontario, Canadawho were prescribed linezolid from 2014 to 2021. Renal impairment was defined using baseline estimated glomerular filtration rate <30 mL/min/1.73 m2 or receipt of dialysis. The primary outcomes were change in platelet count and severe thrombocytopenia (platelet count <50 × 109/L) within 90 days. Secondary outcomes included bleeding, neutropenia, peripheral neuropathy, optic neuropathy, acidosis, serotonin syndrome, and mortality. Inverse probability of treatment weighting on propensity score was used to balance comparison groups on baseline health. Results: Of 625 patients, 98 (15.7%) patients had renal impairment. The mean (SD) platelet change was -88.3 (108.4) 109/L in the renal impairment group and -76.5 (109.8) 109/L in the no renal impairment group, with an adjusted mean difference of -29.4 (95% CI, -53.4 to -5.3; P = .0165). Severe thrombocytopenia occurred in 9.2% for the renal impairment group and 5.9% for the no renal impairment group, with an adjusted risk difference of 2.7% (95% CI, -3.1% to 8.6%; P = .3655). There were no significant differences in secondary outcomes between the 2 groups. Conclusions: Patients with renal impairment on linezolid therapy had a larger decrease in platelet count, but their risks for severe thrombocytopenia and bleeding were not significantly different than patients without renal impairment. Linezolid is likely safe in renal impairment without dose adjustment or drug level monitoring.

Field-Assisted Alignment of Cellulose Nanofibrils in a Continuous Flow-Focusing System.

The continuous production of macroscale filaments of 17 µm in diameter comprising aligned TEMPO-oxidized cellulose nanofibrils (CNFs) is conducted using a field-assisted flow-focusing process. The effect of an AC external field on the material's structure becomes significant at a certain voltage, beyond which augmentations of the CNF orientation factor up to 16% are obtained. Results indicate that the electric field significantly contributes to improve the CNF ordering in the bulk, while the CNF alignment on the filament surface is only slightly affected by the applied voltage. X-ray diffraction shows that CNFs are densely packed anisotropically in the plane parallel to the filament axis without any preferential out of plane orientation. The improved nanoscale ordering combined with the tight CNF packing yields impressive enhancements in mechanical properties, with stiffness up to 25 GPa and more than 63% (up to 260 MPa), 46% (up to 2.8%), and 120% (up to 4.7 kJ/m3) increase in tensile strength, strain-to-failure, and toughness, respectively. This study demonstrates for the first time the control over the structural ordering of anisotropic nanoparticles in a dynamic system using an electric field, which can have important implications for the development of sustainable alternatives to synthetic textiles.

Validation of a Weight Threshold-Based Vancomycin Dosing Protocol for Patients Undergoing Intermittent Hemodialysis.

BACKGROUND: Patients receiving intermittent hemodialysis (IHD) are at high risk of acquiring gram-positive infections, which are often treated with IV vancomycin. Despite frequent use of vancomycin in the IHD setting, there is variability in dosing and monitoring practices among clinicians at the study institution. There is also a paucity of evidence regarding optimal vancomycin dosing to achieve target pre-IHD serum concentration. OBJECTIVES: The primary objective was to compare the percentage of treatment courses with a serum vancomycin concentration between 15 and 20 mg/L, measured before the third IHD session, before and after implementation of a weight threshold-based dosing protocol. The secondary objectives were to compare the percentage of treatment courses with a pre-third IHD vancomycin concentration between 10 and 22 mg/L and the number of vancomycin measurements per treatment day, before and after protocol implementation. METHODS: This quasi-experimental, single-centre study included inpatients and outpatients who underwent IHD and received at least 2 IV doses of vancomycin, with vancomycin being measured in an appropriately drawn sample before the third IHD session. Before protocol implementation, vancomycin dosing was at the clinician's discretion (usual care). After protocol implementation, each patient received a loading dose of 1000, 1500, or 2000 mg and a maintenance dose of 500, 750, or 1000 mg, depending on body weight. RESULTS: The percentage of treatment courses with a pre-third IHD vancomycin concentration between 15 and 20 mg/L was greater after implementation of the protocol than with usual care, but the difference was nonsignificant (44% [8/18] versus 20% [3/15], p = 0.27). However, the percentage of treatment courses with a pre-third IHD vancomycin concentration between 10 and 22 mg/L was significantly higher after protocol implementation (94% [17/18] versus 53% [8/15], p = 0.012). There was no difference in the median number of vancomycin measurements per treatment day before and after protocol implementation (0.133 versus 0.125, p = 0.99). CONCLUSIONS: At the study institution, the likelihood of achieving recommended vancomycin concentration increased (relative to previous practice) after implementation of a simplified vancomycin dosing protocol for patients undergoing IHD.

CONTEXTE: Les patients recevant une hémodialyse intermittente (HDI) présentent un risque élevé de contracter des infections à Gram positif, souvent traitées à l'aide de vancomycine par intraveineuse (IV). Malgré l'utilisation fréquente de la vancomycine dans les environnements d'HDI, les pratiques portant sur le dosage et le suivi varient entre les cliniciens de l'institution où l'étude s'est déroulée. Il existe également peu de données probantes sur la dose optimale de vancomycine permettant d'atteindre la concentration sérique cible avant l'HDI. OBJECTIFS: L'objectif principal visait à comparer le pourcentage de traitements à la vancomycine, dont la concentration sérique se situait entre 15 et 20 mg/L, lors de la mesure prise avant la troisième séance de HDI, avant et après la mise en place d'un protocole de dosage basé sur le poids. Les objectifs secondaires visaient à comparer le pourcentage de traitements, dont la concentration de vancomycine mesurée avant la troisième séance d'HDI était comprise entre 10 et 22 mg/L, et le nombre de mesures de vancomycine par jour de traitement, avant et après la mise en place du protocole. MÉTHODES: Cette étude quasi expérimentale, menée dans un seul centre, comprenait des patients hospitalisés et ambulatoires ayant subi une HDI et reçu au moins deux doses de vancomycine par IV et dont un échantillon prélevé de manière appropriée avant la troisième séance d'HDI a permis de mesurer la vancomycine. Avant la mise en place du protocole, le dosage de vancomycine était laissé à la discrétion du clinicien (soins habituels). Après sa mise en place, chaque patient recevait une dose de charge de 1000, 1500 ou 2000 mg et une dose de maintenance de 500, 750 ou 1000 mg selon sa masse corporelle. RÉSULTATS: Le pourcentage de traitements dont la concentration de vancomycine mesurée avant la troisième séance d'HDI était comprise entre 15 et 20 mg/L était plus élevé après la mise en place du protocole qu'après les soins habituels, mais la différence n'était pas significative (44 % [8/18] contre 20 % [3/15], p = 0,27). Cependant, le pourcentage de traitements dont la concentration de vancomycine mesurée avant la troisième séance d'HDI était comprise entre 10 et 22 mg/L était significativement plus élevé après la mise en place du protocole (94 % [17/18] contre 53 % [8/15], p = 0,012). Le nombre moyen de mesures de vancomycine par traitement n'avait pas varié entre le jour précédant et le jour suivant la mise en place du protocole (0,133 contre 0,125, p = 0,99). CONCLUSIONS: Dans l'institution où l'étude s'est déroulée, la probabilité d'atteindre la concentration de vancomycine recommandée avait augmenté après la mise en place d'un protocole simplifié de dosage de vancomycine pour les patients recevant une HDI comparativement à une pratique antérieure.