Characteristics and Outcomes of 360 Consecutive COVID-19 Patients Discharged From the Emergency Department With Supplemental Oxygen.

STUDY OBJECTIVE: To describe characteristics and outcomes of coronavirus disease (COVID-19) patients with new supplemental oxygen requirements discharged from a large public urban emergency department (ED) with supplemental oxygen. METHODS: This observational case series describes the characteristics and outcomes of 360 consecutive COVID-19 patients with new supplemental oxygen requirements discharged from a large urban public ED between April 2020 and March 2021 with supplemental oxygen. Primary outcomes included 30-day survival and 30-day survival without unscheduled inpatient admission. Demographic and clinical data were collected through a structured chart review. RESULTS: Among 360 patients with COVID-19 discharged from the ED with supplemental oxygen, 30-day survival was 97.5% (95% confidence interval (CI) 95.3 to 98.9%; n=351), and 30-day survival without unscheduled admission was 81.1% (95% CI 76.7 to 85.0%; n=292). A sensitivity analysis incorporating worst-case-scenario for 12 patients without complete follow-up 30 days after index visit yields 30-day survival of 95.5% (95% CI 92.5 to 97.2%; n=343), and 30-day survival without unscheduled admission of 78.9% (95% CI 74.3 to 83.0%; n=284). Among study patients, 32.2% (n=116) had a nadir ED oxygen saturation of <90%, among these 30-day survival was 97.4% (95% CI 92.6 to 99.4%; n=113), and 30-day survival without unscheduled admission was 76.7% (95% CI 68.8 to 84.1%; n=89). CONCLUSION: COVID-19 patients with new supplemental oxygen requirements discharged from the ED had survival comparable to COVID-19 ED patients with mild exertional hypoxia treated with supplemental oxygen in other settings, and this held true when the analysis was restricted to patients with nadir ED index visit oxygen saturations <90%. Discharge of select COVID-19 patients with supplemental oxygen from the ED may provide a viable alternative to hospitalization, particularly when inpatient capacity is limited.

3D Printed Pericardium Hydrogels To Promote Wound Healing in Vascular Applications.

Vascular grafts that can support total replacement and maintenance by the body of the injured vessel would improve outcomes of major surgical reconstructions. Building scaffolds using components of the native vessel can encourage biological recognition by native cells as well as mimic mechanical characteristics of the native vessel. Evidence is emerging that incorporating predetermined building-blocks into a tissue engineering scaffold may oversimplify the environment and ignore critical structures and binding sites essential to development at the implant. We propose the development of a 3D-printable and degradable hybrid scaffold by combining polyethylene glycol (PEG)acrylate and homogenized pericardium matrix (HPM) to achieve appropriate biological environment as well as structural support. It was hypothesized that incorporation of HPM into PEG hydrogels would affect modulus of the scaffold and that the modulus and biological component would reduce the inflammatory signals produced from arriving macrophages and nearby endothelial cells. HPM was found to provide a number of tissue specific structural proteins including collagen, fibronectin, and glycosaminoglycans. HPM and PEGacrylate formed a hybrid hydrogel with significantly distinct modulus depending on concentration of either component, which resulted in scaffolds with stiffness between 0.5 and 20 kPa. The formed hybrid hydrogel was confirmed through a reduction in primary amines post-cross-linking. Using these hybrid scaffolds, rat bone marrow derived macrophages developed an M2 phenotype in response to low amounts (0.03%, w/v) of HPM in culture but responded with inflammatory phenotypes to high concentrations (0.3%, w/v). When cultured together with endothelial cells, both M1 and M2 macrophages were detected, along with a combination of both inflammatory and healing cytokines. However, the expression of inflammatory cytokines TNFα and IL1ß was significantly (p < 0.05) lower with hybrid hydrogels compared to single component PEG or HPM hydrogels. This reduction in inflammatory cytokines could impact the healing environment that persists at the implantation site. Finally, using this developed hybrid hydrogel, models of neonatal vasculature were manufactured using digital light projection (DLP) 3D printing. The structural control achieved with this novel biomaterial suggests a promising new tool in vascular graft development and research, with potential for complex structures for use in congenital heart defect reconstruction.

Anatomic stemless shoulder arthroplasty and related outcomes: a systematic review.

BACKGROUND: The latest generation of shoulder arthroplasty includes canal-sparing respectively stemless designs that have been developed to allow restoration of the glenohumeral center of rotation independently from the shaft, and to avoid stem-related complications. The stemless prosthesis design has also recently been introduced for use in reverse arthroplasty systems. METHODS: We systematically reviewed the literature for studies of currently available canal-sparing respectively stemless shoulder arthroplasty systems. From the identified series, we recorded the indications, outcome measures, and humeral-sided complications. RESULTS: We identified 11 studies of canal-sparing respectively stemless anatomic shoulder arthroplasty implants, published between 2010 and 2016. These studies included 929 cases, and had a mean follow-up of 26 months (range, 6 to 72 months). The rates of humeral component-related complications ranged between 0 and 7.9 %. The studies reported only a few isolated cases of complications of the humeral component. Some arthroplasty systems are associated with radiological changes, but without any clinical relevance. CONCLUSIONS: All of the published studies of canal-sparing respectively stemless shoulder arthroplasty reported promising clinical and radiological outcomes in short to midterm follow-up. Long-term studies are needed to demonstrate the long-term value of these kind of implants.

A deadly digital dressing: a case of surgical decompression for finger ischemia due to circumferential finger dressing.

BACKGROUND: Tubular gauze dressings are commonly used, but have potential to cause iatrogenic finger ischemia. OBJECTIVES: To inform health care providers of an avoidable complication and to discuss appropriate methods of prevention and treatment. CASE REPORT: We discuss a teenage female's finger that narrowly avoided amputation after a tubular gauze dressing caused iatrogenic ischemia. Surgical decompression using a novel technique successfully salvaged the finger. Operative intervention for this complication has previously been unreported. CONCLUSION: It is important that circumferential digital dressings are applied correctly. Vascular insufficiency from an occlusive dressing is an iatrogenic and avoidable complication. Successful operative decompression may be indicated to minimize tissue loss and improve circulation.

Mild traumatic brain injury and treatment response in prolonged exposure for PTSD.

A proportion of U.S. veterans returning from Iraq and Afghanistan have experienced mild traumatic brain injury (mTBI), which is associated with increased risk for developing posttraumatic stress disorder (PTSD). Prolonged Exposure (PE) has proven effectiveness in the treatment of PTSD; however, some clinicians have reservations about using PE with individuals with a history of mTBI. We examined the impact of PE for veterans with PTSD and with or without a history of mTBI in a naturalistic sample of 51 veterans who received PE at a Veterans Health Administration PTSD clinic. We also analyzed previously collected data from a controlled trial of 22 veterans randomly assigned to PE or present centered therapy. For both sets of data, we found that PE reduced symptom levels and we also did not detect an effect for mTBI, suggesting that PE may be helpful for individuals with PTSD and a history of mTBI.

Written Exposure Therapy vs Prolonged Exposure Therapy in the Treatment of Posttraumatic Stress Disorder: A Randomized Clinical Trial.

Importance: Evidence-based treatments for posttraumatic stress disorder (PTSD) exist, but all require 8 to 15 sessions and thus are less likely to be completed than brief treatments. Written exposure therapy (WET) is a brief and efficacious treatment that has not been directly compared with prolonged exposure therapy (PE), a more time-intensive, exposure-based treatment. Objective: To determine whether WET is noninferior to PE in treating PTSD among veterans. Design, Setting, and Participants: A randomized noninferiority clinical trial was conducted between September 9, 2019, and April 30, 2022. Participants were 178 veterans with PTSD presenting to 1 of 3 Veterans Affairs medical centers. Inclusion criteria consisted of a primary diagnosis of PTSD and stable medication. Exclusion criteria included current psychotherapy for PTSD, high suicide risk, active psychosis, unstable bipolar disorder, and severe cognitive impairment. Independent evaluations were conducted at baseline and 10, 20, and 30 weeks after the first treatment session. Data were analyzed from January 1 to March 31, 2023. Interventions: Participants assigned to WET (n = 88) received five to seven 45- to 60-minute sessions. Participants assigned to PE (n = 90) received eight to fifteen 90-minute sessions. The WET sessions included 30 minutes of writing-based imaginal exposure conducted in session, whereas PE sessions included 40 minutes of in-session imaginal exposure and between-session in vivo exposures. Main Outcomes and Measures: The primary outcome was change in PTSD symptom severity measured with the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) from baseline to the 20-week assessment; noninferiority was defined as a less than 10-point difference between the 2 treatment groups. Difference in treatment dropout was also examined. Results: Of the 178 participants, 134 (75.3%) were men, and the mean (SD) age was 44.97 (13.66) years. In terms of race, 37 participants (20.8%) were Black, 112 (62.9%) were White, 11 (6.2%) were more than 1 race, and 18 (10.1%) were of other race (including American Indian or Alaska Native, Asian, and Native Hawaiian or Other Pacific Islander [some participants did not specify their race when selecting the category "other"]); in terms of ethnicity, 19 participants (10.7%) were Hispanic. Changes in PTSD symptom severity from baseline to all subsequent assessments among individuals randomized to WET were noninferior relative to individuals randomized to PE. The largest difference between treatments was observed at 10 weeks and was in favor of WET (mean difference, 2.42 [95% CI, 0.35-1.46] points). Participants were significantly less likely to drop out of WET compared with PE (11 [12.5%] vs 32 [35.6%]; χ2 = 12.91; Cramer V = 0.27). Conclusions and Relevance: In this study, WET was noninferior to PE in PTSD symptom change and was associated with significantly less attrition. Findings suggest that WET may transcend previously observed barriers to PTSD treatment for both patients and clinicians. Trial Registration: ClinicalTrials.gov Identifier: NCT03962504.

Application of B cell immortalization for the isolation of antibodies and B cell clones from vaccine and infection settings.

The isolation and characterization of neutralizing antibodies from infection and vaccine settings informs future vaccine design, and methodologies that streamline the isolation of antibodies and the generation of B cell clones are of great interest. Retroviral transduction to express Bcl-6 and Bcl-xL and transform primary B cells has been shown to promote long-term B cell survival and antibody secretion in vitro, and can be used to isolate antibodies from memory B cells. However, application of this methodology to B cell subsets from different tissues and B cells from chronically infected individuals has not been well characterized. Here, we characterize Bcl-6/Bcl-xL B cell immortalization across multiple tissue types and B cell subsets in healthy and HIV-1 infected individuals, as well as individuals recovering from malaria. In healthy individuals, naïve and memory B cell subsets from PBMCs and tonsil tissue transformed with similar efficiencies, and displayed similar characteristics with respect to their longevity and immunoglobulin secretion. In HIV-1-viremic individuals or in individuals with recent malaria infections, the exhausted CD27-CD21- memory B cells transformed with lower efficiency, but the transformed B cells expanded and secreted IgG with similar efficiency. Importantly, we show that this methodology can be used to isolate broadly neutralizing antibodies from HIV-infected individuals. Overall, we demonstrate that Bcl-6/Bcl-xL B cell immortalization can be used to isolate antibodies and generate B cell clones from different B cell populations, albeit with varying efficiencies.

Comparison of Prolonged Exposure vs Cognitive Processing Therapy for Treatment of Posttraumatic Stress Disorder Among US Veterans: A Randomized Clinical Trial.

Importance: Posttraumatic stress disorder (PTSD) is a prevalent and serious mental health problem. Although there are effective psychotherapies for PTSD, there is little information about their comparative effectiveness. Objective: To compare the effectiveness of prolonged exposure (PE) vs cognitive processing therapy (CPT) for treating PTSD in veterans. Design, Setting, and Participants: This randomized clinical trial assessed the comparative effectiveness of PE vs CPT among veterans with military-related PTSD recruited from outpatient mental health clinics at 17 Department of Veterans Affairs medical centers across the US from October 31, 2014, to February 1, 2018, with follow-up through February 1, 2019. The primary outcome was assessed using centralized masking. Tested hypotheses were prespecified before trial initiation. Data were analyzed from October 5, 2020, to May 5, 2021. Interventions: Participants were randomized to 1 of 2 individual cognitive-behavioral therapies, PE or CPT, delivered according to a flexible protocol of 10 to 14 sessions. Main Outcomes and Measures: The primary outcome was change in PTSD symptom severity on the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) from before treatment to the mean after treatment across posttreatment and 3- and 6-month follow-ups. Secondary outcomes included other symptoms, functioning, and quality of life. Results: Analyses were based on all 916 randomized participants (730 [79.7%] men and 186 [20.3%] women; mean [range] age 45.2 [21-80] years), with 455 participants randomized to PE (mean CAPS-5 score at baseline, 39.9 [95% CI, 39.1-40.7] points) and 461 participants randomized to CPT (mean CAPS-5 score at baseline, 40.3 [95% CI, 39.5-41.1] points). PTSD severity on the CAPS-5 improved substantially in both PE (standardized mean difference [SMD], 0.99 [95% CI, 0.89-1.08]) and CPT (SMD, 0.71 [95% CI, 0.61-0.80]) groups from before to after treatment. Mean improvement was greater in PE than CPT (least square mean, 2.42 [95% CI, 0.53-4.31]; P = .01), but the difference was not clinically significant (SMD, 0.17). Results for self-reported PTSD symptoms were comparable with CAPS-5 findings. The PE group had higher odds of response (odds ratio [OR], 1.32 [95% CI, 1.00-1.65]; P < .001), loss of diagnosis (OR, 1.43 [95% CI, 1.12-1.74]; P < .001), and remission (OR, 1.62 [95% CI, 1.24-2.00]; P < .001) compared with the CPT group. Groups did not differ on other outcomes. Treatment dropout was higher in PE (254 participants [55.8%]) than in CPT (215 participants [46.6%]; P < .01). Three participants in the PE group and 1 participant in the CPT group were withdrawn from treatment, and 3 participants in each treatment dropped out owing to serious adverse events. Conclusions and Relevance: This randomized clinical trial found that although PE was statistically more effective than CPT, the difference was not clinically significant, and improvements in PTSD were meaningful in both treatment groups. These findings highlight the importance of shared decision-making to help patients understand the evidence and select their preferred treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT01928732.

Comparing written exposure therapy to Prolonged Exposure for the treatment of PTSD in a veteran sample: A non-inferiority randomized design.

Posttraumatic stress disorder (PTSD) is highly prevalent among veterans. Although there are effective treatment approaches for PTSD, such as Prolonged Exposure (PE) and Cognitive Processing Therapy, many providers trained in these approaches do not use them, or use them without sufficient fidelity, and veterans drop out of these treatments at very high rates. The time intensive nature of these treatments is frequently cited as a barrier to receiving the treatment among veterans and delivering the treatment among providers. According, there is an urgent need to establish more efficient and effective PTSD treatment approaches in order to meet the needs of veterans seeking care. Written exposure therapy (WET) is an efficient, exposure-based treatment, and may represent a plausible alternative treatment option to address PTSD in veterans. Although WET has been found to be effective and non-inferior to more time intensive trauma-focused treatment, it has not yet been investigated with a veteran sample. In an ongoing randomized controlled trial (RCT) we are investigating whether WET is non-inferior in treating PTSD compared with the more time intensive PE. The study sample will include 150 men and women veterans diagnosed with PTSD who are randomly assigned to either WET (n = 75) or PE (n = 75). Participants are assessed prior to treatment and 10-, 20-, and 30-weeks after the first treatment session. The primary outcome is PTSD symptom severity assessed with the Clinician Administered PTSD Scale for DSM-5. Establishing that PTSD can be treated effectively with fewer treatment sessions would represent a significant advance in improving access to evidence-based care for veterans with PTSD.

Neutralizing antibody VRC01 failed to select for HIV-1 mutations upon viral rebound.

Infusion of the broadly neutralizing antibody VRC01 has been evaluated in individuals chronically infected with HIV-1. Here, we studied how VRC01 infusions affected viral rebound after cessation of antiretroviral therapy (ART) in 18 acutely treated and durably suppressed individuals. Viral rebound occurred in all individuals, yet VRC01 infusions modestly delayed rebound and participants who showed a faster decay of VRC01 in serum rebounded more rapidly. Participants with strains most sensitive to VRC01 or with VRC01 epitope motifs similar to known VRC01-susceptible strains rebounded later. Upon rebound, HIV-1 sequences were indistinguishable from those sampled at diagnosis. Across the cohort, participant-derived Env showed different sensitivity to VRC01 neutralization (including 2 resistant viruses), yet neutralization sensitivity was similar at diagnosis and after rebound, indicating the lack of selection for VRC01 resistance during treatment interruption. Our results showed that viremia rebounded despite the absence of HIV-1 adaptation to VRC01 and an average VRC01 trough of 221 µg/mL. Although VRC01 levels were insufficient to prevent a resurgent infection, knowledge that they did not mediate Env mutations in acute-like viruses is relevant for antibody-based strategies in acute infection.

Rapamycin weekly maintenance dosing and the potential efficacy of combination sorafenib plus rapamycin but not atorvastatin or doxycycline in tuberous sclerosis preclinical models.

BACKGROUND: Tuberous sclerosis complex (TSC) is an autosomal dominant tumor suppressor syndrome, characterized by hamartomatous growths in the brain, skin, kidneys, lungs, and heart, which lead to significant morbidity. TSC is caused by mutations in the TSC1 or TSC2 genes, whose products, hamartin and tuberin, form a tumor suppressor complex that regulates the PI3K/Akt/mTOR pathway. Early clinical trials show that TSC-related kidney tumors (angiomyolipomas) regress when treated with the mammalian target of rapamycin (mTOR) inhibitor, rapamycin (also known as sirolimus). Although side effects are tolerable, responses are incomplete, and tumor regrowth is common when rapamycin is stopped. Strategies for future clinical trials may include the investigation of longer treatment duration and combination therapy of other effective drug classes. RESULTS: Here, we examine the efficacy of a prolonged maintenance dose of rapamycin in Tsc2+/- mice with TSC-related kidney tumors. Cohorts were treated with rapamycin alone or in combination with interferon-gamma (IFN-g). The schedule of rapamycin included one month of daily doses before and after five months of weekly doses. We observed a 94.5% reduction in kidney tumor burden in Tsc2+/- mice treated (part one) daily with rapamycin (8 mg/kg) at 6 months

The moderating role of negative affect on objective verbal memory performance and subjective memory complaints in healthy older adults.

Subjective memory complaints (SMCs) are part of the diagnostic criteria for Mild Cognitive Impairment (MCI), yet little is known about their etiology. In some previous studies, no direct relation has been found between SMCs and objective memory performance, yet significant correlations have been identified between SMCs and psychological factors such as depression and anxiety. In the current study, we examined whether negative affect moderated the relation between objective memory functioning and SMCs in a sample of healthy, non-demented participants aged 65 and older. As predicted, several negative affect measures moderated the relationship between objective cognitive functioning and SMCs. In the absence of objective memory impairment as indexed by the Rey Auditory Verbal Learning Test (RAVLT) and the Dementia Rating Scale-2nd Edition (DRS-2), higher levels of negative affect were associated with increased levels of SMCs. Moreover, a lower order negative affect factor, anxiety sensitivity, significantly moderated the relation between objective memory functioning and SMCs, after controlling for higher order measures of general negative affectivity. Findings suggest that negative affect, particularly anxiety sensitivity, distorts the subjective appraisal of one's own memory, such that people high on negative affect factors report more episodes of forgetting, even in the absence of objective cognitive impairments.

Hand hygiene in the dermatologist's office: to wash or to rub?

Hand hygiene is a central factor in preventing the spread of disease in the dermatologist's office. The role of hand washing and alcohol-based hand rubs is considered with emphasis on compliance, effectiveness, side effects, and cost. Specific recommendations highlight the importance of using alcohol-based hand rubs as an adjunct to traditional hand-washing methods.

Implicit learning, thought-focused attention and obsessive-compulsive disorder: a replication and extension.

Although significant empirical support exists for both cognitive and neurobiological models of obsessive-compulsive disorder (OCD), there have been few efforts to integrate findings. In this investigation, we attempted to link models by examining relationships between performance on information processing tasks posited to be markers of OCD-related neuropathology and a self-report measure of excessive thought-focused attention (cognitive self-consciousness; CSC). Congruent with predictions and prior research, OCD patients' performance was impaired in comparison to an anxious control group on the Serial Reaction Time (SRT) Task, a measure of implicit procedural learning. Following completion of the SRT, participants' awareness of the embedded stimulus pattern was assessed. As predicted, participants with OCD demonstrated superior performance on this task. Scoring on a measure of CSC correlated with performance on both tasks, although the amount of variance accounted for was modest. Evaluation of OCD symptom subgroups revealed greater procedural learning impairment in a hoarding subgroup. Implications for theory and treatment are discussed.

Reversal of antiplatelet therapy in traumatic intracranial hemorrhage: Does timing matter?

Reversal of antiplatelet therapy with platelet transfusion in traumatic intracranial hemorrhage remains controversial. Several studies have examined this topic but few have investigated whether the timing of transfusion affects outcomes. Patients admitted to a level 1 trauma center from 1/1/14 to 3/31/16 with traumatic intracranial hemorrhage taking pre-injury antiplatelet therapy were retrospectively analyzed. Patients on concurrent pre-injury anticoagulant therapy were excluded. Per institutional guideline, patients on pre-injury clopidogrel received 2 doses of platelets while patients on pre-injury aspirin received 1 dose of platelets. Patients with worsening hemorrhage defined by an increase in the Rotterdam score on follow up CT were compared to those without worsening. Mortality, need for neurosurgical intervention, and timing of platelet transfusion were analyzed. A total of 243 patients were included with 23 (9.5%) having worsening hemorrhage. Patients with worsening hematoma had higher injury severity score, head abbreviated injury scale, incidence of subdural hematoma, mortality, and lower Glasgow coma scale. There was no significant difference in the number of minutes to platelet transfusion between groups. After logistic regression analysis the presence of subdural hematoma and lower admission Glasgow coma scale were predictors of worsening hematoma, while there remained no significant difference in minutes to platelet transfusion. The timing of platelet transfusion did not have any impact on rates of worsening hematoma for patients with traumatic intracranial hemorrhage on pre-injury antiplatelet therapy. Potential risk factors for worsening hematoma in this group are the presence of subdural hematoma and lower admission Glasgow coma scale.

Tuberous sclerosis preclinical studies: timing of treatment, combination of a rapamycin analog (CCI-779) and interferon-gamma, and comparison of rapamycin to CCI-779.

BACKGROUND: Tuberous Sclerosis Complex (TSC) is an autosomal dominant hamartoma disorder with variable expression for which treatment options are limited. TSC is caused by a mutation in either the TSC1 or TSC2 genes, whose products, hamartin and tuberin, function as negative regulators in the highly-conserved mammalian target of rapamycin (mTOR) signaling pathway. Rapamycin (also known as sirolimus), an mTOR inhibitor, has been shown to reduce disease severity in rodent models of TSC and is currently being evaluated in clinical trials in human populations. The cytokine interferon-gamma (IFN-gamma) is also a potential therapeutic agent for TSC. A high-expressing IFN-gamma allele has been associated with reduced disease severity in human TSC patients and it has been shown in mouse models that treatment with exogenous IFN-gamma reduces disease severity. RESULTS: Here, we examine the effects of treating Tsc2+/- mice at different time points with a rapamycin analog (CCI-779) as a single agent or with a combination of CCI-779 and IFN-gamma. We observed that administering a short course of CCI-779 or CCI-779 plus IFN-gamma reduced the severity of kidney lesions if administered after such lesions develop. As long as treatment is given after lesions arise, altering the time period during which treatment was given did not significantly impact the effect of the treatment on disease severity. We did not observe a significant benefit of combination therapy relative to treatment with a rapamycin analog alone in Tsc2+/- mice. We also compared timing of treatment and two mTOR inhibitors (rapamycin and CCI-779) in nude mice bearing Tsc2-/- tumors. CONCLUSION: Preventing the genesis of TSC-related kidney lesions in Tsc2+/- mice is not an effective treatment strategy; rather, the presence of growing tumors appears to be the most important factor when determining an appropriate treatment schedule. Treatment with rapamycin was more effective in reducing tumor growth and improving survival in nude mice bearing Tsc2-/- tumors and also resulted in higher rapamycin levels in blood, brain, and kidney tissue than treatment with an equal milligram dose of CCI-779. We anticipate these results will influence future preclinical and clinical trials for TSC.

Controlled Delivery of Tissue Inductive Factors in a Cardiovascular Hybrid Biomaterial Scaffold.

Hybrid biomaterials, combining naturally derived and synthetic materials, offer a tissue engineering platform that can provide initial mechanical support from a synthetic biomaterial, as well as a viable, bioactive substrate to support native cell infiltration and remodeling. The goal of this work was to develop a directional delivery system for bioactive molecules that can be coupled with a hybrid biomaterial. It was hypothesized that by using poly(propylene fumarate) as a scaffold to encapsulate PLGA microparticles, a tunable and directional release would be achieved from the intact scaffold into the bioactive substrate, pericardium. Release will occur as poly(lactic-co-glycolic acid) microparticles degrade hydrolytically into biocompatible molecules, leaving the PPF scaffold unchanged within the release time frame and able to mechanically support the pericardium substrate through remodeling. This study evaluated the degradation and strength of the composite polymer layer, and determined the release of encapsulated factors to occur over 8 days, while the bulk polymer remained intact with near 100% of its original mass. Next, this study demonstrated sustained bioactive molecule release into cell culture, causing significant changes to cellular metabolic activity. In particular, delivering vascular endothelial growth factor from the composite material to endothelial cells increased metabolic activity over the same cells with unloaded composite material. Additionally, delivering tumor necrosis factor α from the composite material to L929 cells significantly reduced metabolic activity compared to the same cells with unloaded composite material (p < 0.05). Finally, directional release into a bioactive substrate was confirmed with localized immunostaining of the encapsulated factor.

Including Memory Friction in Single- and Two-State Quantum Dynamics Simulations.

We present a simple computational algorithm that allows for the inclusion of memory friction in a quantum dynamics simulation of a small, quantum, primary system coupled to many atoms in the surroundings. We show how including a memory friction operator, F̂, in the primary quantum system's Hamiltonian operator builds memory friction into the dynamics of the primary quantum system. We show that, in the harmonic, semi-classical limit, this friction operator causes the classical phase-space centers of a wavepacket to evolve exactly as if it were a classical particle experiencing memory friction. We also show that this friction operator can be used to include memory friction in the quantum dynamics of an anharmonic primary system. We then generalize the algorithm so that it can be used to treat a primary quantum system that is evolving, non-adiabatically on two coupled potential energy surfaces, i.e., a model that can be used to model H atom transfer, for example. We demonstrate this approach's computational ease and flexibility by showing numerical results for both harmonic and anharmonic primary quantum systems in the single surface case. Finally, we present numerical results for a model of non-adiabatic H atom transfer between a reactant and product state that includes memory friction on one or both of the non-adiabatic potential energy surfaces and uncover some interesting dynamical effects of non-memory friction on the H atom transfer process.

3D-printed microfluidic devices.

Microfluidics is a flourishing field, enabling a wide range of biochemical and clinical applications such as cancer screening, micro-physiological system engineering, high-throughput drug testing, and point-of-care diagnostics. However, fabrication of microfluidic devices is often complicated, time consuming, and requires expensive equipment and sophisticated cleanroom facilities. Three-dimensional (3D) printing presents a promising alternative to traditional techniques such as lithography and PDMS-glass bonding, not only by enabling rapid design iterations in the development stage, but also by reducing the costs associated with institutional infrastructure, equipment installation, maintenance, and physical space. With the recent advancements in 3D printing technologies, highly complex microfluidic devices can be fabricated via single-step, rapid, and cost-effective protocols, making microfluidics more accessible to users. In this review, we discuss a broad range of approaches for the application of 3D printing technology to fabrication of micro-scale lab-on-a-chip devices.

Venous thromboembolism prophylaxis after total joint arthroplasty.

Venous thromboembolism (VTE) prophylaxis after total joint arthroplasty is considered best practice. However, over the past 5 years, there has been considerable debate about the ideal prophylactic regimen or modality. The American Academy of Orthopaedic Surgeons and the American College of Chest Physicians published their most recent clinical practice guidelines about VTE prophylaxis in 2011 and 2012, respectively. In addition, the Surgical Care Improvement Project published their latest recommendations in 2014. In this review, commonly used VTE prophylaxis options and the latest clinical guidelines will be discussed.