358 research outputs found

    On the interconnection structure of cellular networks

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    This paper presents a model which can be used to represent many of the interconnection patterns commonly found in cellular networks. This model is then used to classify cellular networks according to the degree of regularity in their interconnection patterns. Specifically, three classes of cellular networks, corresponding to three forms of interconnection regularity, are defined. A concept of network realization is then developed to detect structural similarities in different networks and is used to compare the computational capabilities of these three classes

    Endoscopic Optical Coherence Tomography (OCT): Advances in Gastrointestinal Imaging

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    In the rapidly evolving field of endoscopic gastrointestinal imaging, Optical Coherence Tomography (OCT) has found many diverse applications. We present the current status of OCT and its practical applications in imaging normal and abnormal mucosa in the esophagus, stomach, small and large intestines, and biliary and pancreatic ducts. We highlight technical aspects and principles of imaging, assess published data, and suggest future directions for OCT-guided evaluation and therapy

    Folic Acid Functionalized Nanoparticles for Enhanced Oral Drug Delivery

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    The oral absorption of drugs that have poor bioavailability can be enhanced by encapsulation in polymeric nanoparticles. Transcellular transport of nanoparticle-encapsulated drug, possibly through transcytosis, is likely the major mechanism through which nanoparticles improve drug absorption. We hypothesized that the cellular uptake and transport of nanoparticles can be further increased by targeting the folate receptors expressed on the intestinal epithelial cells. The objective of this research was to study the effect of folic acid functionalization on transcellular transport of nanoparticle-encapsulated paclitaxel, a chemotherapeutic with poor oral bioavailability. Surface-functionalized poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles loaded with paclitaxel were prepared by the interfacial activity assisted surface functionalization technique. Transport of paclitaxel-loaded nanoparticles was investigated using Caco-2 cell monolayers as an in vitro model. Caco-2 cells were found to express folate receptor and the drug efflux protein, p-glycoprotein, to high levels. Encapsulation of paclitaxel in PLGA nanoparticles resulted in a 5-fold increase in apparent permeability (P(app)) across Caco-2 cells. Functionalization of nanoparticles with folic acid further increased the transport (8-fold higher transport compared to free paclitaxel). Confocal microscopic studies showed that folic acid-functionalized nanoparticles were internalized by the cells and that nanoparticles did not have any gross effects on tight junction integrity. In conclusion, our studies indicate that folic acid functionalized nanoparticles have the potential to enhance the oral absorption of drugs with poor oral bioavailability

    Outcomes with Orbital and Rotational Atherectomy for Inpatient Percutaneous Coronary Intervention

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    INTRODUCTION: Our objective was to describe the contemporary outcomes of orbital atherectomy (OA) vs. rotational atherectomy (RA) use for inpatient percutaneous coronary intervention (PCI) in the United States. Data on the use of OA vs. RA in contemporary inpatient PCI are limited. METHODS: We queried the Nationwide Readmission Database (NRD) from January to November for the years 2016-2017 to identify hospitalizations of patients who underwent PCI with atherectomy. We conducted a multivariate regression analysis to identify variables associated with in-hospital mortality. RESULTS: We included 77,040 records of patients who underwent inpatient PCI with atherectomy. Of those, 71,610 (93%) had RA, and 5430 (7%) had OA. There was no significant change in the trend of using OA or RA over 2016 and 2017. OA was less utilized in patients presenting with ST-segment elevation myocardial infarction (STEMI) (4.3% vs. 46.8%, p \u3c 0.001). In our cohort, OA was associated with lower in-hospital mortality (3.1% vs. 5%, p \u3c 0.001) and 30-day urgent readmission (\u3c 0.01% vs. 0.2%, p = 0.009), but a higher risk of coronary perforation (1.7% vs. 0.6%, p \u3c 0.001) and cardiac tamponade (1% vs. 0.3%, p \u3c 0.001) and a higher cost of index hospitalization (28,199vs.28,199 vs. 23,188, p \u3c 0.001) compared with RA. CONCLUSION: RA remains the predominant atherectomy modality for inpatient PCI in the United States (93%). There was no change in the trend of use for either modality over the years 2016 and 2017. OA was noted to have a lower incidence of in-hospital death, but a higher risk of coronary perforation and a higher cost of index hospitalization for the overall unmatched cohorts

    Triggerable tough hydrogels for gastric resident dosage forms

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    Systems capable of residing for prolonged periods of time in the gastric cavity have transformed our ability to diagnose and treat patients. Gastric resident systems for drug delivery, ideally need to be: ingestible, be able to change shape or swell to ensure prolonged gastric residence, have the mechanical integrity to withstand the forces associated with gastrointestinal motility, be triggerable to address any side effects, and be drug loadable and release drug over a prolonged period of time. Materials that have been primarily utilized for these applications have been largely restricted to thermoplastics and thermosets. Here we describe a novel set of materials, triggerable tough hydrogels, meeting all these requirement, supported by evaluation in a large animal model and ultimately demonstrate the potential of triggerable tough hydrogels to serve as prolonged gastric resident drug depots. Triggerable tough hydrogels may be applied in myriad of applications, including bariatric interventions, drug delivery, and tissue engineering.Bill & Melinda Gates Foundation (Grant OPP1096734)Bill & Melinda Gates Foundation (Grant OPP1139927)National Institutes of Health (U.S.) (Grant EB000244

    Effects of Renal Denervation vs Sham in Resistant Hypertension after Medication Escalation:Prespecified Analysis at 6 Months of the RADIANCE-HTN TRIO Randomized Clinical Trial

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    IMPORTANCE: Although early trials of endovascular renal denervation (RDN) for patients with resistant hypertension (RHTN) reported inconsistent results, ultrasound RDN (uRDN) was found to decrease blood pressure (BP) vs sham at 2 months in patients with RHTN taking stable background medications in the Study of the ReCor Medical Paradise System in Clinical Hypertension (RADIANCE-HTN TRIO) trial. OBJECTIVES: To report the prespecified analysis of the persistence of the BP effects and safety of uRDN vs sham at 6 months in conjunction with escalating antihypertensive medications. DESIGN, SETTING, AND PARTICIPANTS: This randomized, sham-controlled, clinical trial with outcome assessors and patients blinded to treatment assignment, enrolled patients from March 11, 2016, to March 13, 2020. This was an international, multicenter study conducted in the US and Europe. Participants with daytime ambulatory BP of 135/85 mm Hg or higher after 4 weeks of single-pill triple-combination treatment (angiotensin-receptor blocker, calcium channel blocker, and thiazide diuretic) with estimated glomerular filtration rate (eGFR) of 40 mL/min/1.73 m(2 )or greater were randomly assigned to uRDN or sham with medications unchanged through 2 months. From 2 to 5 months, if monthly home BP was 135/85 mm Hg or higher, standardized stepped-care antihypertensive treatment starting with aldosterone antagonists was initiated under blinding to treatment assignment. INTERVENTIONS: uRDN vs sham procedure in conjunction with added medications to target BP control. MAIN OUTCOMES AND MEASURES: Six-month change in medications, change in daytime ambulatory systolic BP, change in home systolic BP adjusted for baseline BP and medications, and safety. RESULTS: A total of 65 of 69 participants in the uRDN group and 64 of 67 participants in the sham group (mean [SD] age, 52.4 [8.3] years; 104 male [80.6%]) with a mean (SD) eGFR of 81.5 (22.8) mL/min/1.73 m(2) had 6-month daytime ambulatory BP measurements. Fewer medications were added in the uRDN group (mean [SD], 0.7 [1.0] medications) vs sham (mean [SD], 1.1 [1.1] medications; P = .045) and fewer patients in the uRDN group received aldosterone antagonists at 6 months (26 of 65 [40.0%] vs 39 of 64 [60.9%]; P = .02). Despite less intensive standardized stepped-care antihypertensive treatment, mean (SD) daytime ambulatory BP at 6 months was 138.3 (15.1) mm Hg with uRDN vs 139.0 (14.3) mm Hg with sham (additional decreases of −2.4 [16.6] vs −7.0 [16.7] mm Hg from month 2, respectively), whereas home SBP was lowered to a greater extent with uRDN by 4.3 mm Hg (95% CI, 0.5-8.1 mm Hg; P = .03) in a mixed model adjusting for baseline and number of medications. Adverse events were infrequent and similar between groups. CONCLUSIONS AND RELEVANCE: In this study, in patients with RHTN initially randomly assigned to uRDN or a sham procedure and who had persistent elevation of BP at 2 months after the procedure, standardized stepped-care antihypertensive treatment escalation resulted in similar BP reduction in both groups at 6 months, with fewer additional medications required in the uRDN group. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT0264942
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