Closed-Loop Therapy and Preservation of C-Peptide Secretion in Type 1 Diabetes.

BACKGROUND: Whether improved glucose control with hybrid closed-loop therapy can preserve C-peptide secretion as compared with standard insulin therapy in persons with new-onset type 1 diabetes is unclear. METHODS: In a multicenter, open-label, parallel-group, randomized trial, we assigned youths 10.0 to 16.9 years of age within 21 days after a diagnosis of type 1 diabetes to receive hybrid closed-loop therapy or standard insulin therapy (control) for 24 months. The primary end point was the area under the curve (AUC) for the plasma C-peptide level (after a mixed-meal tolerance test) at 12 months after diagnosis. The analysis was performed on an intention-to-treat basis. RESULTS: A total of 97 participants (mean [±SD] age, 12±2 years) underwent randomization: 51 were assigned to receive closed-loop therapy and 46 to receive control therapy. The AUC for the C-peptide level at 12 months (primary end point) did not differ significantly between the two groups (geometric mean, 0.35 pmol per milliliter [interquartile range, 0.16 to 0.49] with closed-loop therapy and 0.46 pmol per milliliter [interquartile range, 0.22 to 0.69] with control therapy; mean adjusted difference, -0.06 pmol per milliliter [95% confidence interval {CI}, -0.14 to 0.03]). There was not a substantial between-group difference in the AUC for the C-peptide level at 24 months (geometric mean, 0.18 pmol per milliliter [interquartile range, 0.06 to 0.22] with closed-loop therapy and 0.24 pmol per milliliter [interquartile range, 0.05 to 0.30] with control therapy; mean adjusted difference, -0.04 pmol per milliliter [95% CI, -0.14 to 0.06]). The arithmetic mean glycated hemoglobin level was lower in the closed-loop group than in the control group by 4 mmol per mole (0.4 percentage points; 95% CI, 0 to 8 mmol per mole [0.0 to 0.7 percentage points]) at 12 months and by 11 mmol per mole (1.0 percentage points; 95% CI, 7 to 15 mmol per mole [0.5 to 1.5 percentage points]) at 24 months. Five cases of severe hypoglycemia occurred in the closed-loop group (in 3 participants), and one occurred in the control group; one case of diabetic ketoacidosis occurred in the closed-loop group. CONCLUSIONS: In youths with new-onset type 1 diabetes, intensive glucose control for 24 months did not appear to prevent the decline in residual C-peptide secretion. (Funded by the National Institute for Health and Care Research and others; CLOuD ClinicalTrials.gov number, NCT02871089.).

Increasing and sustaining discharges by noon - a multi-year process improvement project.

High hospital occupancy degrades emergency department performance by increasing wait times, decreasing patient satisfaction, and increasing patient morbidity and mortality. Late discharges contribute to high hospital occupancy by increasing emergency department (ED) patient length of stay (LOS). We share our experience with increasing and sustaining early discharges at a 650-bed academic medical center in the United States. Our process improvement project followed the Institute of Medicine Model for Improvement of successive Plan‒Do‒Study‒Act cycles. We implemented multiple iterative interventions over 41 months. As a result, the proportion of discharge orders before 10 am increased from 8.7% at baseline to 22.2% (p < 0.001), and the proportion of discharges by noon (DBN) increased from 9.5% to 26.8% (p < 0.001). There was no increase in balancing metrics because of our interventions. RA-LOS (Risk Adjusted Length Of Stay) decreased from 1.16 to 1.09 (p = 0.01), RA-Mortality decreased from 0.65 to 0.61 (p = 0.62) and RA-Readmissions decreased from 0.92 to 0.74 (p < 0.001). Our study provides a roadmap to large academic facilities to increase and sustain the proportion of patients discharged by noon without negatively impacting LOS, 30-day readmissions, and mortality. Continuous performance evaluation, adaptability to changing resources, multidisciplinary engagement, and institutional buy-in were crucial drivers of our success.

Performance of Dietary Behaviors in Chronic Community-Dwelling Stroke Survivors: A Mixed-Methods Study.

In order to gain a better understanding of post-stroke dietary behaviors (e.g., selecting, accessing, and preparing healthy foods) among chronic, community-dwelling stroke survivors, we conducted a mixed-methods study consisting of a quantitative online survey (n = 63) and follow-up focus groups with a subset of participants (n = 7). Perceived performance, assistance required, adaptive equipment and compensatory strategies used, and sources of education and training were examined. Results demonstrated (1) diminished post-stroke performance for most dietary behaviors (e.g., grocery shopping, meal preparation), (2) an increased desire to eat healthily to prevent recurrent stroke, (3) variable use of adaptive equipment and compensatory strategies, and (4) limited healthcare-based dietary behavior education and training. These results suggest that stroke survivors could benefit from increased dietary behavior intervention to improve dietary behavior performance. Findings can be used to guide clinical intervention and design future research studies.

Does local fat thickness correlate with post-operative infection in open reduction and internal fixation of acetabulum fractures?

PURPOSE: Obesity is an epidemic which increases risk of many surgical procedures. Previous studies in spine and hip arthroplasty have shown that fat thickness measured on preoperative imaging may be as or more reliable in assessment of risk of post-operative infection and/or wound complications than body mass index (BMI). We hypothesized that, similarly, increased local fat thickness at the surgical site is a predictor of wound complication in acetabulum fracture surgery. METHODS: Patients who underwent open reduction and internal fixation (ORIF) of an acetabulum fracture through a Kocher-Langenbeck (K-L) approach at a single institution from 2013 to 2020 were identified. Pre-operative CT scans were used to measure fat thickness from the skin to the greater trochanter in line with the surgical approach. Post-operative infections and wound complications were recorded and associated with fat thickness and BMI. RESULTS: 238 patients met inclusion criteria. 12 patients had either infection or a wound complication (5.0%). There was no significant association with BMI or preoperative fat thickness on post-operative infection or wound complication (p-value 0.73 and 0.86). CONCLUSIONS: There is no statistically significant association of post-operative infection or wound complications in patients with increased soft tissue thickness or increased BMI. ORIF of acetabulum fractures through a K-L approach can be performed safely in patients with large subcutaneous fat thickness and high BMI with low risk of infection or wound complications.

Multiparametric, Label-Free Analysis of Microfluidic Droplets via a Dynamic Phase Grating Approach.

Droplet-based microfluidic systems possess many fundamental advantages as a platform for the analysis of chemical and biological species. However, whereas on-chip operations have rapidly developed over the past decades, approaches for analyzing target molecules within droplets have largely remained limited to methods requiring bulky and expensive instrumentation. In this work, we describe a droplet analysis approach whereby the droplet train itself is the sensing construct. Specifically, the droplet train is interrogated as a transmission phase grating, allowing high-throughput, label-free, solution-phase, and multi-parametric analysis of droplet contents. Importantly, three distinct properties of generated droplets can be simultaneously extracted using this conceptually simple and experimentally straightforward measurement approach. Under constant droplet generation conditions, measurement of droplet viscosity is achieved by monitoring changes in zero order to first order peak separation in the far-field diffraction pattern, with a sensitivity of 2.28 × 10-4 cSt per µm change in peak separation. In parallel, measurement of droplet refractive index (RI) is achieved by measuring changes in the ratio of the zero order to first order peak intensity, with a sensitivity of 2.14 × 10-4 RI units per unit change in a diffracted peak intensity ratio. Finally, droplet generation frequency is determined from the time-varying oscillation of the peak height ratio, yielding comparable results to an expensive high-speed camera commonly used for droplet imaging. Importantly, the experimental strategy for this approach is straightforward and does not require expensive instrumentation; therefore, it may find utility in affordable and portable analysis approaches applied to diverse droplet microfluidic assays.

Effect of Tight Glycemic Control on Pancreatic Beta Cell Function in Newly Diagnosed Pediatric Type 1 Diabetes: A Randomized Clinical Trial.

Importance: Near normalization of glucose levels instituted immediately after diagnosis of type 1 diabetes has been postulated to preserve pancreatic beta cell function by reducing glucotoxicity. Previous studies have been hampered by an inability to achieve tight glycemic goals. Objective: To determine the effectiveness of intensive diabetes management to achieve near normalization of glucose levels on preservation of pancreatic beta cell function in youth with newly diagnosed type 1 diabetes. Design, Setting, and Participants: This randomized, double-blind, clinical trial was conducted at 6 centers in the US (randomizations from July 20, 2020, to October 13, 2021; follow-up completed September 15, 2022) and included youths with newly diagnosed type 1 diabetes aged 7 to 17 years. Interventions: Random assignment to intensive diabetes management, which included use of an automated insulin delivery system (n = 61), or standard care, which included use of a continuous glucose monitor (n = 52), as part of a factorial design in which participants weighing 30 kg or more also were assigned to receive either oral verapamil or placebo. Main Outcomes and Measures: The primary outcome was mixed-meal tolerance test-stimulated C-peptide area under the curve (a measure of pancreatic beta cell function) 52 weeks from diagnosis. Results: Among 113 participants (mean [SD] age, 11.8 [2.8] years; 49 females [43%]; mean [SD] time from diagnosis to randomization, 24 [5] days), 108 (96%) completed the trial. The mean C-peptide area under the curve decreased from 0.57 pmol/mL at baseline to 0.45 pmol/mL at 52 weeks in the intensive management group, and from 0.60 to 0.50 pmol/mL in the standard care group (treatment group difference, -0.01 [95% CI, -0.11 to 0.10]; P = .89). The mean time in the target range of 70 to 180 mg/dL, measured with continuous glucose monitoring, at 52 weeks was 78% in the intensive management group vs 64% in the standard care group (adjusted difference, 16% [95% CI, 10% to 22%]). One severe hypoglycemia event and 1 diabetic ketoacidosis event occurred in each group. Conclusions and Relevance: In youths with newly diagnosed type 1 diabetes, intensive diabetes management, which included automated insulin delivery, achieved excellent glucose control but did not affect the decline in pancreatic C-peptide secretion at 52 weeks. Trial Registration: ClinicalTrials.gov Identifier: NCT04233034.

Effect of Verapamil on Pancreatic Beta Cell Function in Newly Diagnosed Pediatric Type 1 Diabetes: A Randomized Clinical Trial.

Importance: In preclinical studies, thioredoxin-interacting protein overexpression induces pancreatic beta cell apoptosis and is involved in glucotoxicity-induced beta cell death. Calcium channel blockers reduce these effects and may be beneficial to beta cell preservation in type 1 diabetes. Objective: To determine the effect of verapamil on pancreatic beta cell function in children and adolescents with newly diagnosed type 1 diabetes. Design, Setting, and Participants: This double-blind, randomized clinical trial including children and adolescents aged 7 to 17 years with newly diagnosed type 1 diabetes who weighed 30 kg or greater was conducted at 6 centers in the US (randomized participants between July 20, 2020, and October 13, 2021) and follow-up was completed on September 15, 2022. Interventions: Participants were randomly assigned 1:1 to once-daily oral verapamil (n = 47) or placebo (n = 41) as part of a factorial design in which participants also were assigned to receive either intensive diabetes management or standard diabetes care. Main Outcomes and Measures: The primary outcome was area under the curve values for C-peptide level (a measure of pancreatic beta cell function) stimulated by a mixed-meal tolerance test at 52 weeks from diagnosis of type 1 diabetes. Results: Among 88 participants (mean age, 12.7 [SD, 2.4] years; 36 were female [41%]; and the mean time from diagnosis to randomization was 24 [SD, 4] days), 83 (94%) completed the trial. In the verapamil group, the mean C-peptide area under the curve was 0.66 pmol/mL at baseline and 0.65 pmol/mL at 52 weeks compared with 0.60 pmol/mL at baseline and 0.44 pmol/mL at 52 weeks in the placebo group (adjusted between-group difference, 0.14 pmol/mL [95% CI, 0.01 to 0.27 pmol/mL]; P = .04). This equates to a 30% higher C-peptide level at 52 weeks with verapamil. The percentage of participants with a 52-week peak C-peptide level of 0.2 pmol/mL or greater was 95% (41 of 43 participants) in the verapamil group vs 71% (27 of 38 participants) in the placebo group. At 52 weeks, hemoglobin A1c was 6.6% in the verapamil group vs 6.9% in the placebo group (adjusted between-group difference, -0.3% [95% CI, -1.0% to 0.4%]). Eight participants (17%) in the verapamil group and 8 participants (20%) in the placebo group had a nonserious adverse event considered to be related to treatment. Conclusions and Relevance: In children and adolescents with newly diagnosed type 1 diabetes, verapamil partially preserved stimulated C-peptide secretion at 52 weeks from diagnosis compared with placebo. Further studies are needed to determine the longitudinal durability of C-peptide improvement and the optimal length of therapy. Trial Registration: ClinicalTrials.gov Identifier: NCT04233034.

A comparison of two hybrid closed-loop systems in adolescents and young adults with type 1 diabetes (FLAIR): a multicentre, randomised, crossover trial.

BACKGROUND: Management of type 1 diabetes is challenging. We compared outcomes using a commercially available hybrid closed-loop system versus a new investigational system with features potentially useful for adolescents and young adults with type 1 diabetes. METHODS: In this multinational, randomised, crossover trial (Fuzzy Logic Automated Insulin Regulation [FLAIR]), individuals aged 14-29 years old, with a clinical diagnosis of type 1 diabetes with a duration of at least 1 year, using either an insulin pump or multiple daily insulin injections, and glycated haemoglobin (HbA1c) levels of 7·0-11·0% (53-97 mmol/mol) were recruited from seven academic-based endocrinology practices, four in the USA, and one each in Germany, Israel, and Slovenia. After a run-in period to teach participants how to use the study pump and continuous glucose monitor, participants were randomly assigned (1:1) using a computer-generated sequence, with a permuted block design (block sizes of two and four), stratified by baseline HbA1c and use of a personal MiniMed 670G system (Medtronic) at enrolment, to either use of a MiniMed 670G hybrid closed-loop system (670G) or the investigational advanced hybrid closed-loop system (Medtronic) for the first 12-week period, and then participants were crossed over with no washout period, to the other group for use for another 12 weeks. Masking was not possible due to the nature of the systems used. The coprimary outcomes, measured with continuous glucose monitoring, were proportion of time that glucose levels were above 180 mg/dL (>10·0 mmol/L) during 0600 h to 2359 h (ie, daytime), tested for superiority, and proportion of time that glucose levels were below 54 mg/dL (<3·0 mmol/L) calculated over a full 24-h period, tested for non-inferiority (non-inferiority margin 2%). Analysis was by intention to treat. Safety was assessed in all participants randomly assigned to treatment. This trial is registered with ClinicalTrials.gov, NCT03040414, and is now complete. FINDINGS: Between June 3 and Aug 22, 2019, 113 individuals were enrolled into the trial. Mean age was 19 years (SD 4) and 70 (62%) of 113 participants were female. Mean proportion of time with daytime glucose levels above 180 mg/dL (>10·0 mmol/L) was 42% (SD 13) at baseline, 37% (9) during use of the 670G system, and 34% (9) during use of the advanced hybrid closed-loop system (mean difference [advanced hybrid closed-loop system minus 670G system] -3·00% [95% CI -3·97 to -2·04]; p<0·0001). Mean 24-h proportion of time with glucose levels below 54 mg/dL (<3·0 mmol/L) was 0·46% (SD 0·42) at baseline, 0·50% (0·35) during use of the 670G system, and 0·46% (0·33) during use of the advanced hybrid closed-loop system (mean difference [advanced hybrid closed-loop system minus 670G system] -0·06% [95% CI -0·11 to -0·02]; p<0·0001 for non-inferiority). One severe hypoglycaemic event occurred in the advanced hybrid closed-loop system group, determined to be unrelated to study treatment, and none occurred in the 670G group. INTERPRETATION: Hyperglycaemia was reduced without increasing hypoglycaemia in adolescents and young adults with type 1 diabetes using the investigational advanced hybrid closed-loop system compared with the commercially available MiniMed 670G system. Testing an advanced hybrid closed-loop system in populations that are underserved due to socioeconomic factors and testing during pregnancy and in individuals with impaired awareness of hypoglycaemia would advance the effective use of this technology FUNDING: National Institute of Diabetes and Digestive and Kidney Diseases.

Noninvasive Glucose Monitor Using Dielectric Spectroscopy.

OBJECTIVE: The Alertgy noninvasive continuous glucose monitor (ANICGM) is a novel wristband device that reports glucose levels without entailing skin puncture. This study evaluated the performance of the ANICGM compared to a Food and Drug Administration-approved glucose meter in patients with type 2 diabetes. METHODS: The ANICGM device measures changes in the electromagnetic field generated by its sensor to produce a dielectric spectrum. The data contained within this spectrum are used in tandem with machine learning algorithms to estimate blood glucose levels. Values from the ANICGM were collected, sent to the Alertgy lab, formatted, and compared with fingerstick blood glucose levels, which were measured using the Accuchek Inform II glucometer. Fifteen patients completed three 120-minute sessions. The mean absolute relative difference (MARD) was calculated. RESULTS: MARD values were compared between study days 2 and 3. The MARD for day 2 was 18.5% (95% CI, 12.8-42.2%), and the MARD for day 3 was 15.3% (95% CI, 12.3-18.4%). The difference in the MARD between days 2 and 3 was not statistically significant (P = .210). CONCLUSION: The resulting MARDs suggest that further investigation into the use of dielectric spectroscopy for glucose monitoring should be explored.

A Retrospective Look at a Cervical Spine Clearance Protocol in Pediatric Trauma Patients at a Level-1 Trauma Center.

BACKGROUND: Adult studies have demonstrated the efficacy of written protocols for clearance of the cervical spine. However, less than half of recently surveyed pediatric trauma centers report using a documented protocol. Little data exists on such protocols in pediatric populations, but interest remains because of potential reductions in radiation exposure, time to clearance, hospital stay, and specialist referral. However, missed injury can have devastating consequences. The purpose of this study is to examine the efficacy in detecting injury of an implemented cervical spine clearance protocol at a level-1 pediatric trauma hospital. METHODS: A retrospective review was performed on pediatric patients presenting as activated traumas to the emergency department of a single level-1 pediatric trauma hospital between May 2010 and October 2018. This institution has utilized a written cervical spine clearance protocol throughout this time. Presence of cervical spine injury, documented clearance, cervical spine imaging, and follow-up documentation were reviewed for any missed injuries. RESULTS: There were no missed cervical spine injuries. Five-hundred sixty-three clinically significant cervical spine injuries were identified, representing 16.5% of patients. Of these, 96 were fractures, dislocations, or ligamentous injuries, representing 2.8% of all patients. Most cervical spine clearances were performed by trauma surgery. Advanced imaging of the cervical spine was ordered for 43.2% of patients overall and trended down over time. CONCLUSION: Documented cervical spine clearance protocols are effective for detection of significant injury in pediatric trauma patients. This study suggests these protocols minimize risk of missed injury and may prevent unnecessary radiation exposure, delayed clearance, prolonged hospitalization, or unnecessary specialist referral. CLINICAL RELEVANCE: Utilization of a standard written protocol for cervical spine clearance likely prevents missed injury and helps to minimize radiation exposure in pediatric populations. Further research is needed on evaluation and management of pediatric cervical spine trauma.

Characterization of the impact of mixing and droplet volumes on the behavior of microfluidic ion-selective droptodes.

Droplet microfluidic optodes, or "droptodes", have emerged as a powerful technology for rapid detection of small ions in complex matrices. While using segmented aqueous phases provides the benefits of sample isolation, the influence of the liquid nature of the oil carrier phase has not yet been explored. In this paper, we examine the influence of microfluidic parameters on droptode efficiency, using potassium-sensitive droptodes as a model system. We found that while changing flow rates on device does not change droptode performance, both channel geometry and droplet size significantly impact droptode efficiency. Specifically, enhanced mixing of the droplets leads to faster equilibration on device and lowers limits of detection by about one order of magnitude. We also found that increasing the size of the sample droplet, at the expense of the size of the oil carrier/sensing phase, leads to higher sensitivity in the linear region of the droptode. These easily manipulated properties will allow one device to potentially be adapted for several different applications, based upon the type and concentration range of measurement required.

Association of obesity and diabetes with physical activity and fruit and vegetable consumption in stroke survivors.

BACKGROUND: Engaging in unhealthy behaviours [poor diet, insufficient physical activity (PA)] increases risk for recurrent stroke and can be compounded by obesity and diabetes, but the association of obesity and diabetes with poor diet and insufficient PA in stroke survivors is unknown. OBJECTIVE: The purpose of this study was to compare prevalences of low fruit and vegetable consumption (low FV consumption, <1 fruit and <1 vegetable daily) and low physical activity (low PA, <150 minutes of weekly moderate-intensity PA) in stroke survivors, stratified by obesity-diabetes status (neither condition, obesity only, diabetes only, both conditions). METHODS: Cross-sectional data from 32 876 non-institutionalized, US stroke survivors aged ≥45 years from the 2015 and 2017 Behavioral Risk Factor Surveillance System were examined. Weighted, age-adjusted prevalence estimates and adjusted odds ratios (AORs) of the investigated unhealthy behaviours (adjusted for sex, age, race, income, education and marital status) and 95% confidence intervals (CIs) were calculated. RESULTS: Prevalences of low FV consumption and low PA exceeded 50% across all obesity-diabetes categories. Compared with respondents with neither obesity nor diabetes, AORs for low PA were increased for respondents with both obesity and diabetes (2.02, 95% CI: 1.72-2.37) and respondents with obesity only (1.31, 1.13-1.53); AORs for low FV consumption did not differ across obesity-diabetes categories. CONCLUSIONS: Results indicated a joint effect of obesity and diabetes with low PA among stroke survivors. Regardless of obesity-diabetes status, however, prevalence of low FV consumption and low PA exceeded 50%. Targeted interventions that modify these unhealthy behaviours among stroke survivors should be explored.

Effect of Continuous Glucose Monitoring on Glycemic Control in Patients With Type 2 Diabetes Treated With Basal Insulin: A Randomized Clinical Trial.

Importance: Continuous glucose monitoring (CGM) has been shown to be beneficial for adults with type 2 diabetes using intensive insulin therapy, but its use in type 2 diabetes treated with basal insulin without prandial insulin has not been well studied. Objective: To determine the effectiveness of CGM in adults with type 2 diabetes treated with basal insulin without prandial insulin in primary care practices. Design, Setting, and Participants: This randomized clinical trial was conducted at 15 centers in the US (enrollment from July 30, 2018, to October 30, 2019; follow-up completed July 7, 2020) and included adults with type 2 diabetes receiving their diabetes care from a primary care clinician and treated with 1 or 2 daily injections of long- or intermediate-acting basal insulin without prandial insulin, with or without noninsulin glucose-lowering medications. Interventions: Random assignment 2:1 to CGM (n = 116) or traditional blood glucose meter (BGM) monitoring (n = 59). Main Outcomes and Measures: The primary outcome was hemoglobin A1c (HbA1c) level at 8 months. Key secondary outcomes were CGM-measured time in target glucose range of 70 to 180 mg/dL, time with glucose level at greater than 250 mg/dL, and mean glucose level at 8 months. Results: Among 175 randomized participants (mean [SD] age, 57 [9] years; 88 women [50%]; 92 racial/ethnic minority individuals [53%]; mean [SD] baseline HbA1c level, 9.1% [0.9%]), 165 (94%) completed the trial. Mean HbA1c level decreased from 9.1% at baseline to 8.0% at 8 months in the CGM group and from 9.0% to 8.4% in the BGM group (adjusted difference, -0.4% [95% CI, -0.8% to -0.1%]; P = .02). In the CGM group, compared with the BGM group, the mean percentage of CGM-measured time in the target glucose range of 70 to 180 mg/dL was 59% vs 43% (adjusted difference, 15% [95% CI, 8% to 23%]; P < .001), the mean percentage of time at greater than 250 mg/dL was 11% vs 27% (adjusted difference, -16% [95% CI, -21% to -11%]; P < .001), and the means of the mean glucose values were 179 mg/dL vs 206 mg/dL (adjusted difference, -26 mg/dL [95% CI, -41 to -12]; P < .001). Severe hypoglycemic events occurred in 1 participant (1%) in the CGM group and in 1 (2%) in the BGM group. Conclusions and Relevance: Among adults with poorly controlled type 2 diabetes treated with basal insulin without prandial insulin, continuous glucose monitoring, as compared with blood glucose meter monitoring, resulted in significantly lower HbA1c levels at 8 months. Trial Registration: ClinicalTrials.gov Identifier: NCT03566693.

How Adults With Stroke Conceptualize Physical Activity: An Exploratory Qualitative Study.

IMPORTANCE: Physical activity (PA) is recommended for improving physical and cardiovascular function but can be challenging because of stroke-related impairments. A better understanding of how adults with stroke conceptualize PA could assist in developing effective interventions for increasing poststroke PA. OBJECTIVE: To explore how adults with stroke conceptualize PA. DESIGN: Phenomenological qualitative design. SETTING: Participants' homes. PARTICIPANTS: Community-dwelling adults with chronic (>6 mo) stroke (N = 15). OUTCOMES AND MEASURES: Semistructured interviews were conducted with participants. Data were analyzed by means of inductive content analysis to identify key themes. RESULTS: Three key themes emerged: (1) moderate to vigorous PA, which includes exercise-related activities (going to the gym, walking, playing sports); (2) PA necessary for performing daily activities and occupations, which includes basic and instrumental activities of daily living; and (3) avoiding sedentary behavior, which includes not wanting to sit for long periods of time, avoiding boredom, and valuing PA over being sedentary. CONCLUSIONS AND RELEVANCE: Participants broadly categorized PA, encompassing multiple activity types, which is encouraging because reducing sedentary behavior and increasing PA of any intensity can improve cardiometabolic health. Interventions that complement and enhance these conceptualizations, alone or in combination with other mechanisms of action, should be explored for their efficacy in increasing PA in adults with stroke. WHAT THIS ARTICLE ADDS: After stroke, perceptions of PA encompass exercise, daily activities and occupations, and avoiding sedentary behavior; these perceptions could be harnessed to promote PA among adults after stroke.

Silicon Photonic Microring Resonator Arrays as a Universal Detector for Capillary Electrophoresis.

Electrophoretic separations conventionally rely on chromogenic, fluorogenic, or redox properties for analyte detection that, in many instances, involve chemical modification of samples prior to analysis. For analytes natively lacking chemical signatures, refractive index-based measurements are appealing as a method to detect these molecules without pretreatment. Microring resonators are a type of whispering gallery mode sensor capable of detecting bulk changes in refractive index. Here, we demonstrate the use of silicon photonic microring resonator arrays as a postcolumn detector for capillary electrophoresis. In this approach, we establish the universal detection capabilities of microrings through calibration with analytes lacking unique spectral signatures. Separations of small molecule mixtures are demonstrated using capillary zone electrophoresis. For these separations, the microring resonators maintain a linear response over several orders of magnitude in concentration for three candidate small molecules. Successful separation of three sugars with direct detection is also demonstrated. We further present the successful separation and detection of three model proteins, exemplifying the promise of microring resonators arrays as a biocompatible detector for capillary electrophoresis. Additionally, the spatially offset, array-based nature of the sensing platform enables real-time analysis of analyte mobility and performance characterization-a combination that is not typically provided using single-point detectors.

Translational Opportunities for Microfluidic Technologies to Enable Precision Epigenomics.

Personalizing health care by taking genetic, environmental, and lifestyle factors into account is central to modern medicine. The crucial and pervasive roles epigenetic factors play in shaping gene-environment interactions are now well recognized. However, identifying robust epigenetic biomarkers and translating them to clinical tests has been difficult due in part to limitations of available platforms to detect epigenetic features genome-wide (epigenomic assays). This Feature introduces several important prospects for precision epigenomics, highlights capabilities and limitations of current laboratory technologies, and emphasizes opportunities for microfluidic tools to facilitate translation of epigenetic analyses to the clinic, with a particular focus on methods to profile gene-associated histone modifications and their impacts on chromatin structure and gene expression.

Coherent silicon photonic interferometric biosensor with an inexpensive laser source for sensitive label-free immunoassays.

Over the past two decades, integrated photonic sensors have been of major interest to the optical biosensor community due to their capability to detect low concentrations of molecules with label-free operation. Among these, interferometric sensors can be read-out with simple, fixed-wavelength laser sources and offer excellent detection limits but can suffer from sensitivity fading when not tuned to their quadrature point. Recently, coherently detected sensors were demonstrated as an attractive alternative to overcome this limitation. Here we show, for the first time, to the best of our knowledge, that this coherent scheme provides sub-nanogram per milliliter limits of detection in C-reactive protein immunoassays and that quasi-balanced optical arm lengths enable operation with inexpensive Fabry-Perot-type lasers sources at telecom wavelengths.

Real-Time Measurement of Polymer Brush Dynamics Using Silicon Photonic Microring Resonators: Analyte Partitioning and Interior Brush Kinetics.

Polymer brushes are found in biomedical and industrial technologies, where they exhibit functionalities considerably dependent on polymer brush-solvent-analyte interactions. It remains a difficult challenge to quickly analyze solvent-swollen polymer brushes, both at the solvent-polymer brush interface and in the brush interior, as well as to monitor the kinetics of interaction of solvent-swollen brushes with key analytes. Here, we demonstrate the novel use of silicon photonic microring resonators to characterize in situ swollen polymer brush-analyte interactions. By monitoring resonant wavelength shifts, we find that brush-solvent-analyte interaction parameters can be extracted from a single set of data or from successive analyte introductions using a single brush-coated sensor. The partition coefficient of three industrially relevant plasticizers into hydrophobic and hydrophilic brushes was determined and found to be in agreement with known solubility trends. We found that the diffusion coefficient of the plasticizer into the brush decreases as brush thickness increases, supporting a model of a dense inner brush layer and diffuse outer layer. pKa's of pH-sensitive brushes were determined on the microring resonator platform; upon increasing the dry brush thickness, the pKa for poly(2-dimethylamino ethyl methacrylate) decreased from 8.5 to approach the bulk material pKa of 7.3 and showed dependence on the presence and concentration of salt. These proof-of-concept experiments show how the surface-sensitive nature of the microring resonator detection platform provides valuable information about the interaction of the polymer brushes with the solvents and analytes, not easily accessed by other techniques.

A linear mass concentration detector for solvent gradient polymer separations.

Characterization of copolymers requires the measurement of two distributions-molecular weight (MW) and chemical composition (CC). Molecular weight distributions (MWD) are traditionally determined using size exclusion chromatography (SEC) run under isocratic solvent conditions. Chemical composition distributions (CCD) are often determined using liquid adsorption chromatography (LC) with solvent gradients. The use of solvent gradients, however, often limits options of compatible detectors. A gradient compatible, universal linear mass concentration detector is a longstanding unmet need. Many industrially-relevant polymers lack chromophores or other discriminating moieties requiring detectors with a universal response. Differential refractive index (dRI) is incompatible with gradient elution due to its small dynamic range. Charged aerosol detectors (CAD) and evaporative light scattering detectors (ELSD) are probably the most promising options for gradient elution detection, but both suffer from a nonlinear mass concentration response. Silicon photonic microring resonators are optical sensors that are responsive to changes in the local refractive index (RI). The substantial dynamic range of this technology makes it attractive for refractive index-based detection during solvent gradient elution. Previously, the microring resonator platform was used as a SEC detector to characterize the MWD of broadly dispersed polystyrene (PS) standards. In this study, we demonstrate the gradient compatibility of the microring resonator platform for polymer detection by quantifying the CCD of polymer blend components. Control experiments were run with UV and ELSD detection, highlighting the uniqueness of the platform as a linear mass concentration detector with a universal detector response.

Multimodality Imaging of Abdominopelvic Tumors with Venous Invasion.

A broad range of abdominal and pelvic tumors can manifest with or develop intraluminal venous invasion. Imaging features at cross-sectional modalities and contrast-enhanced US that allow differentiation of tumor extension within veins from bland thrombus include the expansile nature of tumor thrombus and attenuation and enhancement similar to those of the primary tumor. Venous invasion is a distinctive feature of hepatocellular carcinoma and renal cell carcinoma with known prognostic and treatment implications; however, this finding remains an underrecognized characteristic of multiple other malignancies-including cholangiocarcinoma, adrenocortical carcinoma, pancreatic neuroendocrine tumor, and primary venous leiomyosarcoma-and can be a feature of benign tumors such as renal angiomyolipoma and uterine leiomyomatosis. Recognition of tumor venous invasion at imaging has clinical significance and management implications for a range of abdominal and pelvic tumors. For example, portal vein invasion is a strong negative prognostic indicator in patients with hepatocellular carcinoma. In patients with rectal cancer, diagnosis of extramural venous invasion helps predict local and distant recurrence and is associated with worse survival. The authors present venous invasion by vascular distribution and organ of primary tumor origin with review of typical imaging features. Common pitfalls and mimics of neoplastic thrombus, including artifacts and anatomic variants, are described to help differentiate these findings from tumor in vein. By accurately diagnosing tumor venous invasion, especially in tumors where its presence may not be a typical feature, radiologists can help referring clinicians develop the best treatment strategies for their patients. ©RSNA, 2020.