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Piezoelectric tube actuators with cantilevered optical fibers have enabled the miniaturization of scanning image acquisition techniques for endoscopic implementation. To achieve raster scanning for such a miniaturized system, the first resonant frequency should be of the order of 10 s of Hz. We explore adding a mass at an intermediate location along the length of the fiber to alter the resonant frequencies of the system. We provide a mathematical model to predict resonant frequencies for a cantilevered beam with an intermediate mass. The theoretical and measured data match well for various fiber lengths, mass sizes, and mass attachment locations along the fiber., (Copyright © 2021 by ASME.)

Background and study aims  Perforation of the duodenal wall opposing the major papilla due to a migrated pancreatobiliary stent rarely has been described in the literature as a complication of endoscopic retrograde cholangiopancreatography (ERCP). Factors associated with perforation from migrated stents from ERCP are unknown. Patients and methods  This was a retrospective, observational study. Patients were identified from January 1, 1994 to May 31, 2019 in a prospectively maintained ERCP database. Results  Eleven cases of duodenal perforation from migrated pancreatobiliary stents placed at ERCP were identified during the study period. All cases involved biliary stents, placed for biliary stricture management. The perforating stent was plastic in 10 cases (91 %). This complication occurred in one in 2,293 ERCP procedures in which a pancreatobiliary stent was placed. Conclusion  This complication is more common with biliary stents compared to pancreatic stents. This may be related to the angle of exit of biliary stents being more perpendicular to the opposing duodenal wall and the near exclusive use of external pigtail plastic stents in the pancreatic duct. All perforating plastic stents were ≥ 9 cm in length. Longer stents may provide leverage for perforation with a migration event., Competing Interests: Competing interests Dr. Lehman is a consultant for Cook Medical. Dr. Sherman is a consultant for Cook Medical, Olympus America, and Boston Scientific. Dr. Gromski is a consultant for Boston Scientific. Dr. Easler is a consultant for Boston Scientific., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

We demonstrate the use of patterned dichroic surfaces with reflective optical power to create multiple optical paths in a single lens system. The application of these surfaces enables a micro-endoscope to accommodate multiple imaging technologies with only one optical system, making the packaging more compact and reliable. The optical paths are spectrally separated using different wavelengths for each path. The dichroic surfaces are designed such that the visible wavelengths transmit through the surfaces optically unaffected, but the near-infrared wavelengths are reflected in a telescope-like configuration with the curved dichroic surfaces providing reflective optical power. We demonstrate wide-field visible monochromatic imaging and microscopic near-infrared imaging using the same set of lenses. The on-axis measured resolution of the wide-field imaging configuration is approximately 14 µm, and the measured resolution of the microscopic imaging configuration is approximately 2 µm. Wide-field white-light imaging of an object is also demonstrated for a qualitative perspective on the imaging capabilities. Other configurations and applications in fields such as optical metrology are discussed to expand on the versatility of the demonstrated optical system.

The essential oils (EO) of R. officinalis and L. dentata have been widely used due to their antioxidant activity. However, due to their high volatility, the loading of EO into polymeric nanocapsules (NC) represents an efficient way of retaining their effect in future topical administration. In this way, the quantitative determination of EO incorporated into NC is necessary for simultaneous monitoring of the main components of the EO during the nanoencapsulation process as well as for precise and exact dosing of the components used during the performance of in vitro and in vivo biological tests. In this study, EO were isolated by hydrodistillation in a Clevenger-type apparatus and characterized by GC-MS and GC-FID analyses. The major constituents of EO- R. officinalis were camphor (39.46%) and 1,8-cineole (14.63%), and for EO- L. dentata were 1,8-cineole (68.59%) and β -pinene (11.53%). A new analytical method based on GC-FID for quantification of free and encapsulated EO was developed and validated according to ICH. Linearity, limit of detection and quantification, and intra- and interday precision parameters were determined. The methods were linear and precise for the quantification of the main components of EO. The EO were encapsulated by nanoprecipitation and were analyzed by the GC-FID method validated for their direct quantification. The NC size was 200 nm with homogeneous size distribution. The quantification of the incorporated EO within a NC is an important step in NC characterization. In this way, an encapsulation efficiency of at least 59.03% and 41.15% of total EO- R. officinalis and EO- L. dentata , respectively, was obtained. Simple, repeatable, and reproducible methods were developed as an analytical tool for the simultaneous quantification of the main components of EO loaded in polymeric nanocapsules as well as their monitoring in biological assays.

[This corrects the article on p. 384 in vol. 11, PMID: 21079714.].

Chronic kidney disease (CKD) is a progressive condition characterized by a permanent and irreversible loss of renal function. In accordance to international guidelines, CKD clinical diagnosis methods are based on creatinine and albumin levels and glomerular filtration rate. Unfortunately, these parameters are scarcely affected in early stages, and its inherent intrinsic variability only allows for the identification of intermediate and advanced stages, when life expectancy has become shorter and treatment poses a significant financial investment. In this context, several targeted strategies have been designed for searching novel markers. Among them, "omics" techniques have emerged, mainly based on proteomics and metabolomics research. Urine and serum samples have been selected as starting material to conduct the identification of new CKD biomarkers, capable of differentiating between stages and predicting progression outcomes. In many cases, the principal objective is to develop a fast and reliable clinical method for non-invasive analysis in the early progression stages of the disease. On the other hand, significant efforts have been directed to identify molecules related to the CKD end stage in order to adequate therapies, reduce impairments, and have a positive impact on survival rate. In this article, the state of the art of novel proposed biomarkers for CKD identification is reviewed, with the aim of underlining its molecular diversity, emphasizing chemical structure differences and correlating its biological relevance. Efforts directed in this line could provide evidence of metabolic pathways imbalance, and lead to the development of new integral strategies for CKD evaluation and management., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

The CB1 cannabinoid receptor, the main target of Δ(9)-tetrahydrocannabinol (THC), the most prominent psychoactive compound of marijuana, plays a crucial regulatory role in brain development as evidenced by the neurodevelopmental consequences of its manipulation in animal models. Likewise, recreational cannabis use during pregnancy affects brain structure and function of the progeny. However, the precise neurobiological substrates underlying the consequences of prenatal THC exposure remain unknown. As CB1 signaling is known to modulate long-range corticofugal connectivity, we analyzed the impact of THC exposure on cortical projection neuron development. THC administration to pregnant mice in a restricted time window interfered with subcerebral projection neuron generation, thereby altering corticospinal connectivity, and produced long-lasting alterations in the fine motor performance of the adult offspring. Consequences of THC exposure were reminiscent of those elicited by CB1 receptor genetic ablation, and CB1-null mice were resistant to THC-induced alterations. The identity of embryonic THC neuronal targets was determined by a Cre-mediated, lineage-specific, CB1 expression-rescue strategy in a CB1-null background. Early and selective CB1 reexpression in dorsal telencephalic glutamatergic neurons but not forebrain GABAergic neurons rescued the deficits in corticospinal motor neuron development of CB1-null mice and restored susceptibility to THC-induced motor alterations. In addition, THC administration induced an increase in seizure susceptibility that was mediated by its interference with CB1-dependent regulation of both glutamatergic and GABAergic neuron development. These findings demonstrate that prenatal exposure to THC has long-lasting deleterious consequences in the adult offspring solely mediated by its ability to disrupt the neurodevelopmental role of CB1 signaling.

Background: Wound healing is a complex process; during the process angiogenesis takes place, that presents clinically as erythema, telangiectasia and edema. Pulsed dye laser (PDL) has a wavelength of 585-595 nm, which targets the chromophore hemoglobin., Objective: Determine the level of improvement of post-dermatological surgery scars., Methods: Thirty patients attending for excision lesion were recruited. They were randomized to 1 of 2 groups. Group 1 scar was randomly divided into 2 parts, one half received PDL 595 nm on 3 occasions; the first after suture removal, 15 and 45 days. Group 2 in one half laser application was simulated while the other was left untreated. The Vancouver scar scale (VSS) was used by an external evaluator to assess the scars. Two skin biopsies were also obtained one before and one after laser treatment., Results: The VSS at 45 days decreased in a significant way in the treatment group from 4 to 1 (P = .005). In the control group decreased from 2 to 1.3 (P = .056). No significant difference was found between the presence of inflammatory infiltrate of patients in the placebo group., Conclusion: This study confirmed the usefulness of pulsed dye laser for improving the appearance of scars.

Background: Cardiac transplantation in adult patients with congenital heart disease poses numerous challenges. The optimal operative and postoperative management strategies remain unclear. The purpose of our study was to (1) characterize the adult patient with a congenital heart condition undergoing transplantation, the operation, and the postoperative course; (2) report the survival after heart transplantation at our center; and (3) discuss issues surrounding the unique setting we provide for the operative and postoperative care of this complex patient cohort., Methods: We performed a retrospective cohort study of 12 consecutive adult patients with a prior history of congenital heart disease who underwent heart transplantation at a single, large, academic center between September 1, 2005, and September 1, 2013. The operations were performed by a surgeon specializing in congenital heart disease in an adult hospital. Postoperative care was provided jointly by that surgeon and the adult cardiac transplantation team., Results: At operation, the median age and weight were 41 years (range, 16 to 72 years) and 65 kg (range, 45 to 104 kg), and 100% of patients had undergone previous operations. The median donor ischemic time was 197 minutes (range, 137 to 282 minutes). The median cardiopulmonary bypass time was 210 minutes (range, 175 to 457 minutes), and the median total operating time was 582 minutes (range, 389 to 968 minutes). Three patients required mechanical support to be weaned from cardiopulmonary bypass. Postoperatively, 3 patients required the addition of mechanical support in the intensive care unit, and 3 patients required tracheostomy for prolonged ventilation. The majority of patients had a complicated postoperative course (66%). The median number of noncardiac consultants required to help care for these patients was four (range, two to 12). The mortality was 0%., Conclusions: Cardiac transplantation in adults with congenital cardiac disease is challenging, is fraught with adverse events, and requires meticulous care and teamwork for success. A surgeon specializing in congenital heart conditions may be best to handle the operative challenges, and an adult hospital with access to certain technology and consultant services may be best to handle the postoperative challenges in this difficult patient population., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

The potential impact that offshore wind farms may cause on nearby marine radars should be considered before the wind farm is installed. Strong radar echoes from the turbines may degrade radars' detection capability in the area around the wind farm. Although conventional computational methods provide accurate results of scattering by wind turbines, they are not directly implementable in software tools that can be used to conduct the impact studies. This paper proposes a simple model to assess the clutter that wind turbines may generate on marine radars. This method can be easily implemented in the system modeling software tools for the impact analysis of a wind farm in a real scenario.

Complex interactions between periphery and the brain regulate food intake in mammals. Cannabinoid type-1 (CB1) receptor antagonists are potent hypophagic agents, but the sites where this acute action is exerted and the underlying mechanisms are not fully elucidated. To dissect the mechanisms underlying the hypophagic effect of CB1 receptor blockade, we combined the acute injection of the CB1 receptor antagonist rimonabant with the use of conditional CB1-knockout mice, as well as with pharmacological modulation of different central and peripheral circuits. Fasting/refeeding experiments revealed that CB1 receptor signaling in many specific brain neurons is dispensable for the acute hypophagic effects of rimonabant. CB1 receptor antagonist-induced hypophagia was fully abolished by peripheral blockade of β-adrenergic transmission, suggesting that this effect is mediated by increased activity of the sympathetic nervous system. Consistently, we found that rimonabant increases gastrointestinal metabolism via increased peripheral β-adrenergic receptor signaling in peripheral organs, including the gastrointestinal tract. Blockade of both visceral afferents and glutamatergic transmission in the nucleus tractus solitarii abolished rimonabant-induced hypophagia. Importantly, these mechanisms were specifically triggered by lipid-deprivation, revealing a nutrient-specific component acutely regulated by CB1 receptor blockade. Finally, peripheral blockade of sympathetic neurotransmission also blunted central effects of CB1 receptor blockade, such as fear responses and anxiety-like behaviors. These data demonstrate that, independently of their site of origin, important effects of CB1 receptor blockade are expressed via activation of peripheral sympathetic activity. Thus, CB1 receptors modulate bidirectional circuits between the periphery and the brain to regulate feeding and other behaviors.

Background: Cardiac stress tests for diagnosis of coronary artery disease (CAD) are incompletely sensitive and specific., Objective: We examined the frequency of significant CAD in patients presenting to the emergency department (ED) with chest pain who have had a recent negative or inconclusive (<85% of predicted maximum heart rate) cardiac stress test., Methods: This was a retrospective chart review of patients identified from ED and cardiology registries at the study hospital. We included patients presenting to the ED with a chief complaint of chest pain, with a negative cardiac stress test in the past three years as the last cardiac test, and hospital admission. One-hundred sixty-four patients met the inclusion criteria. Their admission was reviewed for diagnosis of CAD by positive serum troponin, percutaneous coronary intervention, or positive stress test while an inpatient., Results: Of 164 patients, 122(74.4%, 95% CI 67.7, 81.1) had a negative stress test prior to the index admission, while 42 (25.6%, 95% CI 18.9, 32.3) had otherwise normal but inconclusive stress tests. Thirty-four (20.7%, 95% CI 14.4,27.0) of the included patients were determined to have CAD. Twenty-five of the 122 patients (20.5%, 95% CI 13.3, 27.7) had negative pre-admission stress tests and nine of 42 patients (21.4%, 95% CI 9.0, 33.8) had inclusive stress tests of CAD. A statistical comparison between these two proportions showed no significant difference (p = .973)., Conclusion: Due to inadequate sensitivity, negative non-invasive cardiac stress tests should not be used to rule out CAD. Patients with negative stress tests are just as likely to have CAD as patients with inconclusive stress tests.

Over the course of their postgraduate medical education, physicians are expected not only to acquire an extensive knowledge of clinical medicine and sound procedural skills, but also to develop competence in their other professional roles as communicator, collaborator, mediator, manager, teacher, and patient advocate. Although the need for physicians to develop stronger service delivery skills is well recognized, residency programs may underemphasize formal training in nonclinical proficiencies. As a result, graduates can begin their professional careers with an incomplete understanding of the operation of health care systems and how to utilize system resources in the manner best suited to their patients' needs. This article proposes the content, educational strategy, and needs assessment for an academic program entitled The Business of Emergency Medicine (BOEM). Developed as an adjunct to the (predominantly) clinical content of traditional emergency medicine (EM) training programs, BOEM is designed to enhance the existing academic curricula with additional learning opportunities by which EM residents can acquire a fundamental understanding of the nonclinical skills of their specialty., ((c) 2009 by the Society for Academic Emergency Medicine.)

Multicontrast magnetic resonance imaging (MRI) has shown promise in identifying and characterizing atherosclerotic plaques. One of the limitations of this technique is the lack of a practical automated plaque characterization scheme. In the current study, a prior-information-enhanced clustering (PIEC) technique that utilizes both multicontrast MR images and quantitative T(2) maps is proposed to characterize atherosclerotic plaque components automatically. The PIEC algorithm was assessed on computationally simulated images and multicontrast MRI data of coronary arteries. Multicontrast (T(1)-, T(2)-, partial T(2)-, and proton density-weighted) MR images were acquired from freshly excised human coronary arteries using a 4.7T small-animal scanner. The T(2) distribution for each plaque constituent was measured by exponentially fitting the signal from multiple MR images with different TEs and the same TR. The calculated T(2) distributions were used as the a priori information and combined with the Fuzzy C-Means (FCM)-based clustering algorithm to characterize plaque constituents. The proposed PIEC technique appears to be a promising algorithm for accurate automated plaque characterization.

Purpose: To compare coronary atherosclerotic plaque characterization using multicontrast MRI on: 1) freshly excised vessels under simulated in vivo conditions, and 2) preserved vessels., Materials and Methods: T1-weighted (T1W), T2-weighted (T2W), proton density-weighted (PDW), and diffusion-weighted (DW) MR images were acquired on 13 freshly excised human coronary arteries from explanted hearts. Vessels were imaged in an MR-compatible tissue culture chamber using a 4.7 Tesla small-bore MR scanner. Eight vessels were then preserved in buffered formalin and rescanned following the same imaging protocol. A three-dimensional spatially penalized fuzzy C-means (3D-SPFCM) technique was applied to classify different plaque constituents. The classification results from vessels under "fresh" and "preserved" conditions were compared with corresponding histological sections., Results: For most plaque constituents, the plaque characterization results show no significant difference between fresh and preserved scans, and little difference between scans and the histological reference standard. In the case of thrombus, apparent signal changes between fresh and preserved images were identified. Overall, MR scans conducted under preserved conditions provided a 1.8% to 17.5% greater signal-to-noise ratio (SNR) than those conducted in the fresh stage., Conclusion: Preservation of coronary vessels did not alter the contrast between plaque tissues on multicontrast MRI, and did not significantly change the results of plaque constituent characterization., (Copyright (c) 2006 Wiley-Liss, Inc.)

Background: Despite the effectiveness of early beta-blocker (BB) use in reducing mortality in acute myocardial infarction (AMI), they remain underutilized in the emergency department (ED) management of AMI. The elderly, with higher AMI mortality, and women, may be particularly vulnerable to underutilization of BB., Objective: To determine the effect of age and gender on BB use in AMI in the ED., Methods: A retrospective study of all ST-elevation AMI (STEMI) ED patients presenting to a community hospital ED from 2001 to 2003. Any contraindication to BB use (hypotension, bradycardia, AV block, active bronchospasm, and active congestive heart failure) was determined. Chi-square analysis was used to determine differences by gender and age., Results: Three hundred eighty-five patients with STEMI were identified. Thirty-eight percent were women and 71% were over 60 years of age. Of the 270 (70%) who did not receive BB, 141 (52%) had contraindications to BB use. The total BB eligible group was 244 (63%). Of patients without contraindications to BB, 53% did not receive BB in the ED. By gender, 83 (54%) males and 46 (51%) females did not receive BB (P=.669). By age, 96 subjects (59%) over age 60 and 33 subjects (41%) under age 60 did not receive BB (P=.011)., Conclusion: Despite convincing evidence of effectiveness, BB remain underutilized in ED management of AMI, especially in the elderly. There does not appear to be a gender difference in BB use. Education programs should be directed towards emergency physicians regarding BB use in AMI, especially in elderly ED patients.

The energy of formation and the Lewis acid strength of sulfur vacancies or coordinative unsaturated sites on the MoS2 edges were studied using density functional theory for periodic systems and an electrostatic potential-based methodology. The results suggest that the more energetically favorable sites are located on the sulfur edges; however, their Lewis acid strength is considerably smaller than the site acidity at the molybdenum edges. The acid strength for the reported most hydrodesulfurization active site of RuS2 was also determined. In general, the Lewis acid for the site on RuS2 is 100% smaller than the sites on the Mo edges and around 20% larger than the most favorable site on the S edges of MoS2. Binding of the pyridine molecule in the eta1 adsorption configuration on the considered sites has corroborated the trend of Lewis acidity suggested by the electrostatic potential methodology.