ABSTRACT
Microrobots have the potential for diverse applications, including targeted drug delivery and minimally invasive surgery. Despite advancements in microrobot design and actuation strategies, achieving precise control over their motion remains challenging due to the dominance of viscous drag, system disturbances, physicochemical heterogeneities, and stochastic Brownian forces. Here, a precise control over the interfacial motion of model microellipsoids is demonstrated using time-varying rotating magnetic fields. The impacts of microellipsoid aspect ratio, field characteristics, and magnetic properties of the medium and the particle on the motion are investigated. The role of mobile micro-vortices generated is highlighted by rotating microellipsoids in capturing, transporting, and releasing cargo objects. Furthermore, an approach is presented for controlled navigation through mazes based on real-time particle and obstacle sensing, path planning, and magnetic field actuation without human intervention. The study introduces a mechanism of directing motion of microparticles using rotating magnetic fields, and a control scheme for precise navigation and delivery of micron-sized cargo using simple microellipsoids as microbots.
ABSTRACT
Patchy particles occupy an increasingly important space in soft matter research due to their ability to assemble into intricate phases and states. Being able to fine-tune the interactions among these particles is essential to understanding the principles governing the self-assembly processes. However, current fabrication techniques often yield patches that deviate chemically and physically from the native particles, impeding the identification of the driving forces behind self-assembly. To overcome this challenge, we propose a new approach to synthesizing spherical colloids with a well-defined rough patch on their surface. By treating polystyrene microspheres with vapors of a good solvent, here an acetone-water mixture, we achieve selective polymer corrugation on the particle surface resulting in a chemically similar yet rough surface patch. The key step is the selective condensation of the acetone-water vapors on the apex of the polystyrene microparticles immobilized on a substrate, which leads to rough patch formation. We leverage the ability to tune the vapor-liquid equilibrium of the volatile acetone-water mixture to precisely control the polymer corrugation on the particle surface. We demonstrate the dependence of patch formation on particle and substrate wettability, with the condensation occurring on the particle apex only when it is more wettable than the substrate, which is consistent with Volmer's classical nucleation theory. By combining experiments and molecular dynamics simulations, we identify the role of the rough patch in the depletion interaction-driven self-assembly of the microspheres, which is crucial for designing programmable supracolloidal structures.
ABSTRACT
INTRODUCTION: Long-acting lipoglycopeptides such as dalbavancin may have utility in patients with Gram-positive bloodstream infections (BSI), particularly in those with barriers to discharge or who require prolonged parenteral antibiotic courses. A retrospective cohort study was performed to provide further multicenter real-world evidence on dalbavancin use as a sequential therapy for Gram-positive BSI. METHODS: One hundred fifteen patients received dalbavancin with Gram-positive BSI, defined as any positive blood culture or diagnosed with infective endocarditis, from 13 centers geographically spread across the United States between July 2015 and July 2021. RESULTS: Patients had a mean (SD) age of 48.5 (17.5) years, the majority were male (54%), with many who injected drugs (40%). The most common infection sources (non-exclusive) were primary BSI (89%), skin and soft tissue infection (SSTI) (25%), infective endocarditis (19%), and bone and joint infection (17%). Staphylococcus aureus accounted for 72% of index cultures, coagulase-negative Staphylococcus accounted for 18%, and Streptococcus species in 16%. Dalbavancin started a median (Q1-Q3) of 10 (6-19) days after index culture collection. The most common regimen administered was dalbavancin 1500 mg as one dose for 50% of cases. The primary outcome of composite clinical failure occurred at 12.2%, with 90-day mortality at 7.0% and 90-day BSI recurrence at 3.5%. CONCLUSIONS: Dalbavancin may serve as a useful tool in facilitating hospital discharge in patients with Gram-positive BSI. Randomized controlled trials are anticipated to validate dalbavancin as a surrogate to current treatment standards.
ABSTRACT
Sacituzumab govitecan was initially approved in April 2020 under accelerated approval for the treatment of patients with metastatic triple-negative breast cancer who received at least two prior therapies for metastatic disease. A confirmatory phase III trial evaluating sacituzumab govitecan vs. chemotherapy of the provider's choice was published in April 2021. Based on this trial, the FDA granted sacituzumab govitecan full regulatory approval. This antibody-drug conjugate is composed of a monoclonal antibody targeted at Trop-2 and contains the active metabolite of irinotecan, SN-38, as a cytotoxic side moiety. In a phase III clinical trial, sacituzumab govitecan demonstrated a median progression-free survival of 5.7 months vs. 1.7 months with chemotherapy. It is now an additional option for patients with metastatic triple-negative breast cancer who received at least two prior therapies for metastatic disease.
ABSTRACT
The peer-reviewed, clinical data focusing on foot and ankle gunshot wounds are limited. The present study aimed to evaluate functional outcomes in a case series according to the area of injury, articular involvement, and the presence of infection. From January 2003 through February 2011 (8 years), 37 patients treated at Sinai-Grace Hospital (Detroit, MI) for civilian gunshot wounds localized to the foot and/or ankle were reviewed. Of these, 27 (72.97%) met the inclusion criteria. All acute wounds were thoroughly irrigated in the emergency room (8 of 27, 29.63%) or operating room (19 of 27, 70.37%) within 1 hour of presentation. The injuries were categorized as either zone 1 or 2, if localized distally or proximally to the midtarsal joint, respectively. The Maryland Foot Score was recorded and compared based on the location, articular involvement, and infection status, using analysis of variance. The mean Maryland Foot Score in patients with zone 1 injuries was 89.3 (range 72 to 100) and in patients with zone 2 injures was 61.8 (range 13 to 97; p = .001). The mean Maryland Foot Score in patients with type A injuries was 93.1 (range 72 to 100) and in patients with type B injures was 69.2 (range 13 to 99; p = .001), regardless of location. Intraoperative cultures yielded Staphylococcus epidermidis (7 of 27, 25.93%) and Enterococcus cloacae (1 of 27, 3.7%). No cases of Pseudomonas aeruginosa were found, although 9 cases (33.33%) involved shoe penetration. One third of the cases (9 of 27) yielded intra-articular pain, of which 4 (14.82%) required joint arthrodesis.