Neighborhood Deprivation is Associated With Hospital Length of Stay, Discharge Disposition, and Readmission Rates for Patients Who Survive Hospitalization With Traumatic Brain Injury.

BACKGROUND AND OBJECTIVES: Traumatic brain injury (TBI) is a leading cause of disability in the United States. Limited research exists on the influence of area-level socioeconomic status and outcomes after TBI. This study investigated the correlation between the Area Deprivation Index (ADI) and (1) 90-day hospital readmission rates, (2) facility discharge, and (3) prolonged (≥5 days) hospital length of stay (LOS). METHODS: Single-center retrospective review of adult (18 years or older) patients who were admitted for TBI during 2018 was performed. Patients were excluded if they were admitted for management of a chronic or subacute hematoma. We extracted relevant clinical and demographic data including sex, comorbidities, age, body mass index, smoking status, TBI mechanism, and national ADI. We categorized national ADI rankings into quartiles for analysis. Univariate, multivariate, and area under the receiver operating characteristic curve (AUROC) analyses were performed to assess the relationship between ADI and 90-day readmission, hospital LOS, and discharge disposition. RESULTS: A total of 523 patients were included in final analysis. Patients from neighborhoods in the fourth ADI quartile were more likely to be Black (P = .007), have a body mass index ≥30 kg/m2 (P = .03), have a Charlson Comorbidity Index ≥5 (P = .004), and have sustained a penetrating TBI (P = .01). After controlling for confounders in multivariate analyses, being from a neighborhood in the fourth ADI quartile was independently predictive of 90-day hospital readmission (odds ratio [OR]: 1.35 [1.12-1.91], P = .011) (model AUROC: 0.82), discharge to a facility (OR: 1.46 [1.09-1.78], P = .03) (model AUROC: 0.79), and prolonged hospital LOS (OR: 1.95 [1.29-2.43], P = .015) (model AUROC: 0.85). CONCLUSION: After adjusting for confounders, including comorbidities, TBI mechanism/severity, and age, higher ADI was independently predictive of longer hospital LOS, increased risk of 90-day readmission, and nonhome discharge. These results may help establish targeted interventions to identify at-risk patients after TBI.

Polymer Conjugation to Enhance Cellulase Activity and Preserve Thermal and Functional Stability.

A thermophilic cellulase, FnCel5a, from Fervidobacterium nodosum was conjugated with various functional polymers including cationic, anionic, and strongly and weakly hydrogen bonding polymers. The activity of FnCel5a toward a high-molecular-weight carboxymethyl cellulose substrate was enhanced by polymer conjugation. Activity enhancements of 50% or greater observed for acrylamide and mixed N,N-dimethyl acrylamide-2-(N,N-dimethylamino)ethyl methacrylate polymers, suggesting that the greatest enhancements were caused by polymers capable of noncovalent interactions with the substrate. The conjugates were found to have nearly identical thermodynamic stability to the native enzyme, as assessed by free energy (ΔG), enthalpy (ΔH), and entropy (TΔS) parameters extracted from differential scanning fluorimetry. Polymers tended to confer comparable tolerance to high concentrations of dimethylformamide, with longer polymers typically enabling higher activity relative to shorter polymers. The new FnCel5a conjugates represent an advance in the production of cellulases that maintain activity at high temperatures or in the presence of denaturing organic solvents.

Approaches for Conjugating Tailor-Made Polymers to Proteins.

A series of methods are outlined for attaching functional polymers to proteins. Polymers with good control over structure, functionality, and composition can be created using reversible addition-fragmentation chain transfer (RAFT) polymerization. These polymers can be covalently linked to enzymes and proteins using either the "grafting-to" approach, where a preformed polymer is attached to the protein surface, or the "grafting-from" approach, where the polymer is grown from the protein surface. Methods for grafting-to, or attaching the RAFT chain transfer agent to the protein surface outlined include the commonly used carbodiimide/activated ester (EDC/NHS) coupling. Methods are also outlined to graft-from the surface of the protein using RAFT polymerization. Additionally, it is possible to site specifically introduce a reactive azide group to the protein surface using enzymatic ligation as a posttranslational modification. This reactive azide group can be conjugated to an alkyne-containing polymer using highly efficient click chemistry. These robust protocols can produce protein-polymer conjugates with various architectures and functionalities. Methods are also outlined for characterization of the resulting bioconjugates.

Miniature Mercury Contact Switches For Instrument Temperature Control.

In this short note, we describe the design and construction of several modifications of miniature mercury contact switches for use in laboratory temperature control applications. Commercial contact switches, or contact thermometers as they are commonly called, are limited in their application because of their large size. The units which we present here are much more compact and are thus suitable for a wider range of applications. The limitations of the miniature contact switches in their present configurations are also discussed.